Polyamide composition and molded article

Abstract

The present invention provides a polyamide composition containing 50 to 99 parts by mass of an aliphatic polyamide (1A) formed from a diamine and a dicarboxylic acid, and 1 to 50 parts by mass of a semi-aromatic polyamide (1B) containing a dicarboxylic acid unit that includes at least 75 mol % of isophthalic acid and a diamine unit that includes at least 50 mol % of a diamine of 4 to 10 carbon atoms, wherein the tan δ peak temperature of the polyamide composition is at least 90° C., and the weight average molecular weight Mw of the polyamide composition satisfies 15,000≤Mw≤35,000. The invention also provides a molded article or the like formed using the polyamide composition.

Claims

1. A polyamide composition comprising: 50 to 99 parts by mass of an aliphatic polyamide (1A) formed from a diamine and a dicarboxylic acid, and 1 to 50 parts by mass of a semi-aromatic polyamide (1B) with respect to 100 parts by mass of the total amount of the polyamide (1A) and polyamide (1B) containing a dicarboxylic acid unit that includes at least 75 mol % of isophthalic acid, and a diamine unit that includes at least 50 mol % of a diamine of 4 to 10 carbon atoms, wherein the tan δ peak temperature of the polyamide composition is at least 90° C., and the weight average molecular weight Mw of the polyamide composition satisfies 15,000≤Mw≤35,000.

2. The polyamide composition according to claim 1, wherein the total amount of polyamide having a number average molecular weight Mn of at least 500 but not more than 2,000 is at least 0.5% by mass but less than 2.5% by mass relative to the total mass of polyamide in the polyamide composition.

3. The polyamide composition according to claim 1, wherein the molecular weight distribution Mw/Mn for the polyamide composition is not more than 2.6.

4. The polyamide composition according to claim 1, wherein the total of the amount of amino ends and the amount of carboxyl ends, expressed as a number of equivalents per 1 g of polyamide in the polyamide composition, is from 100 to 175 μeq/g.

5. The polyamide composition according to claim 1, wherein the ratio of the amount of amino ends relative to the total of the amount of amino ends and the amount of carboxyl ends {amount of amino ends/(amount of amino ends+amount of carboxyl ends)} is at least 0.25 but less than 0.4.

6. The polyamide composition according to claim 1, wherein the aliphatic polyamide (1A) is a polyamide 66 or a polyamide 610.

7. The polyamide composition according to claim 1, wherein in the semi-aromatic polyamide (1B), an amount of the isophthalic acid in the dicarboxylic acid unit is 100 mol %.

8. The polyamide composition according to claim 1, wherein the semi-aromatic polyamide (1B) is a polyamide 6I.

9. The polyamide composition according to claim 1, wherein the weight average molecular weight Mw of the semi-aromatic polyamide (1B) satisfies 10,000≤Mw≤25,000.

10. The polyamide composition according to claim 1, wherein the molecular weight distribution Mw/Mn of the semi-aromatic polyamide (1B) is not more than 2.4.

11. The polyamide composition according to claim 1, wherein the difference {Mw(1A)−Mw(1B)} between the weight average molecular weight Mw(1A) of the aliphatic polyamide (1A) and the weight average molecular weight Mw(1B) of the semi-aromatic polyamide (1B) is at least 10,000.

12. The polyamide composition according to claim 1, further comprising a metal phosphite salt and/or a metal hypophosphite salt.

13. The polyamide composition according to claim 1, further comprising a phosphite ester compound.

14. The polyamide composition according to claim 1, further comprising from 5 to 250 parts by mass of an inorganic filler (1C) per 100 parts by mass of the total of the aliphatic polyamide (1A) and the semi-aromatic polyamide (1B).

15. The polyamide composition according to claim 1, further comprising: (2C) a pigment, (2D1) a flame retardant, and (2D2) a flame retardant auxiliary.

16. The polyamide composition according to claim 1, further comprising: (3C1) a flame retardant, and (3C2) a flame retardant auxiliary, wherein the tan δ peak temperature of the polyamide composition is at least 100° C., and the halogen content relative to a total mass of the polyamide composition is greater than 2% by mass but not more than 20% by mass.

17. The polyamide composition according to claim 1, further comprising: (4C) a polyphenylene ether.

18. The polyamide composition according to claim 1, further comprising: (5C1) a flame retardant, (5C2) a flame retardant auxiliary, (5D) a white pigment, and (5E) an ultraviolet absorber, wherein the mass ratio (5E)/(5D) of the ultraviolet absorber (5E) relative to the white pigment (5D) in the polyamide composition is at least 0.15 but less than 2.50.

19. The polyamide composition according to claim 1, further comprising: (6C) carbon fiber.

20. The polyamide composition according to claim 1, further comprising: (7C1) a flame retardant containing a halogen element, (7C2) a flame retardant auxiliary, and (7D) an ultraviolet absorber, wherein the mass ratio {(7D)/halogen element} of the ultraviolet absorber (7D) relative to the halogen element in the polyamide composition is greater than 0.10 but less than 0.75.

Description

EXAMPLES

Examples 1-1 to 1-8, Comparative Examples 1-1 to 1-6

(1) The aspects described above are described below in further detail using a series of specific examples and comparative examples, but the above aspects are in no way limited by the following examples. In the examples, 1 kg/cm.sup.2 means 0.098 MPa.

(2) First, the aliphatic polyamides (1A), the semi-aromatic polyamides (1B), the inorganic filler (1C) and the additive (1D) used in the examples and comparative examples are described below.

(3) (1A) Aliphatic Polyamides

(4) 1A-1: a polyamide 66

(5) 1A-2: a polyamide 66

(6) 1A-3: a polyamide 66

(7) (1B) Semi-Aromatic Polyamides

(8) 1B-1: a polyamide 66/6I (Mw=28,000, Mw/Mn=2.3, total of amount of amino ends and amount of carboxyl ends: 154 μeq/g)

(9) 1B-2: a polyamide 6I (Mw=20,000, Mw/Mn=2.0, total of amount of amino ends and amount of carboxyl ends: 253 μeq/g)

(10) 1B-3: a polyamide 6I T-40 (manufactured by Lanxess AG, Mw=44,000, Mw/Mn=2.8, total of amount of amino ends and amount of carboxyl ends: 147 μeq/g)

(11) 1B-4: a polyamide 6I/6T Grivory 21 (manufactured by Ems Group, Mw=27,000, Mw/Mn=2.2, total of amount of amino ends and amount of carboxyl ends: 139 μeq/g, proportion of isophthalic acid in dicarboxylic acid units: 70 mol %)

(12) 1B-5: a polyamide 6I/6T (Mw=20,000, Mw/Mn=2.0, total of amount of amino ends and amount of carboxyl ends: 231 μeq/g)

(13) 1B-6: a polyamide 6I/6 (Mw=21,000, Mw/Mn=2.0, total of amount of amino ends and amount of carboxyl ends: 239 μeq/g)

(14) (1C) Inorganic Filler

(15) (1) Glass fiber ECS03T275H, manufactured by Nippon Electric Glass Co., Ltd., number-average fiber diameter (average particle size): 10 μm (circular), cut length: 3 mm

(16) In the examples, the average fiber diameter of the glass fiber was measured in the manner described below.

(17) First, the polyamide composition was placed in an electric furnace, and the organic matter contained in the polyamide composition was incinerated. From the residue obtained following this incineration treatment, at least 100 glass fibers were selected randomly and observed using a scanning electron microscope (SEM), and the fiber diameter of each of these glass fibers was measured to determine the number-average fiber diameter.

(18) (1D) Additive

(19) 1D-1: Calcium montanate, product name: Licomont CaV102, manufactured by Clariant AG

(20) The aliphatic polyamides (1A) and semi-aromatic polyamides (1B) used in the examples and comparative examples were produced by appropriate use of (a) and (b) below.

(21) ((a) Dicarboxylic Acids)

(22) (1) Adipic acid (ADA) (manufactured by Wako Pure Chemical Industries, Ltd.)

(23) (2) Isophthalic acid (IPA) (manufactured by Wako Pure Chemical Industries, Ltd.)

(24) ((b) Diamine)

(25) (1) 1,6-diaminohexane (hexamethylenediamine) (C6DA) (manufactured by Tokyo Chemical Industry Co., Ltd.)

(26) ((c) Lactam)

(27) (1) ε-caprolactam (CPL) (manufactured by Wako Pure Chemical Industries, Ltd.)

(28) [Production of Polyamides]

(29) Next is a description of the methods used for producing the aliphatic polyamides (1A) ((1A-1), (1A-2) and (1A-3)) and the semi-aromatic polyamides (1B) ((1B-1), (1B-2), (1B-5) and (1B-6)).

(30) (1A-1: Polyamide 66)

(31) The polyamide polymerization reaction was performed by a “hot melt polymerization method” in the manner described below.

(32) First, 1,500 g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1,500 g of distilled water to prepare an equimolar 50% by mass homogenous aqueous solution of the raw material monomers. This aqueous solution was placed in an autoclave with an internal capacity of 5.4 L, and the autoclave was flushed with nitrogen.

(33) With the solution being stirred at a temperature of 110 to 150° C., steam was gradually extracted and the solution concentration was concentrated to 70% by mass. Subsequently, the internal temperature was raised to 220° C. At this time, the pressure inside the autoclave increased to 1.8 MPa. In this state, steam was gradually extracted to maintain the pressure at 1.8 MPa, and the reaction was continued for one hour until the internal temperature reached 245° C.

(34) Next, the pressure was reduced over a period of one hour. Subsequently, the inside of the autoclave was held for 10 minutes at a reduced pressure of 650 torr (86.66 kPa) using a vacuum device. At this time, the final internal temperature of the polymerization was 265° C.

(35) Subsequently, the autoclave was pressurized with nitrogen, and the polymer was discharged in a strand-like form through a lower spinneret (nozzle), cooled in water and subjected to cutting to form pellets, and the pellets were then dried at 100° C. under a nitrogen atmosphere for 12 hours to obtain a polyamide. Mw was 35,000, and Mw/Mn was 2.0.

(36) (1A-2: Polyamide 66)

(37) With the exception of holding the inside of the autoclave at a reduced pressure of 650 torr (86.66 kPa) for 20 minutes using a vacuum device, a polyamide polymerization reaction (a “hot melt polymerization method”) was performed using the method described above for the production example of 1A-1, thus obtaining pellets of a polyamide. Mw was 40,000, and Mw/Mn was 2.0.

(38) (1A-3: Polyamide 66)

(39) With the exception of holding the inside of the autoclave at a reduced pressure of 300 torr (86.66 kPa) for 10 minutes using a vacuum device, a polyamide polymerization reaction (a “hot melt polymerization method”) was performed using the method described above for the production example of 1A-1, thus obtaining pellets of a polyamide. Mw was 30,000, and Mw/Mn was 2.

(40) (1B-1: Polyamide 66/6I)

(41) The polyamide polymerization reaction was performed by a “hot melt polymerization method” in the manner described below.

(42) First, 1,044 g of an equimolar salt of adipic acid and hexamethylenediamine, 456 g of an equimolar salt of isophthalic acid and hexamethylenediamine, and a 0.5 mol % excess of adipic acid relative to the total of all the equimolar salt components were dissolved in 1,500 g of distilled water to prepare an equimolar 50% by mass homogenous aqueous solution of raw material monomers.

(43) With the solution being stirred at a temperature of 110 to 150° C., steam was gradually extracted and the solution concentration was concentrated to 70% by mass. Subsequently, the internal temperature was raised to 220° C. At this time, the pressure inside the autoclave increased to 1.8 MPa. In this state, steam was gradually extracted to maintain the pressure at 1.8 MPa, and the reaction was continued for one hour until the internal temperature reached 245° C.

(44) Next, the pressure was reduced over a period of one hour. Subsequently, the inside of the autoclave was held for 10 minutes at a reduced pressure of 650 torr (86.66 kPa) using a vacuum device. At this time, the final internal temperature of the polymerization was 265° C.

(45) Subsequently, the autoclave was pressurized with nitrogen, and the polymer was discharged in a strand-like form through a lower spinneret (nozzle), cooled in water and subjected to cutting to form pellets, and the pellets were then dried at 100° C. under a nitrogen atmosphere for 12 hours to obtain a polyamide. Mw was 28,000, Mw/Mn was 2.3, VR was 22, Mw/VR was 1,273, and the proportion of isophthalic acid among the dicarboxylic acid units was 30 mol %.

(46) (1B-2: Polyamide 6I)

(47) The polyamide polymerization reaction was performed by a “hot melt polymerization method” in the manner described below.

(48) First, 1,500 g of an equimolar salt of isophthalic acid and hexamethylenediamine and a 1.5 mol % excess of adipic acid relative to the total mass of the equimolar salt component were dissolved in 1,500 g of distilled water to prepare an equimolar 50% by mass homogenous aqueous solution of raw material monomers.

(49) With the solution being stirred at a temperature of 110 to 150° C., steam was gradually extracted and the solution concentration was concentrated to 70% by mass. Subsequently, the internal temperature was raised to 220° C. At this time, the pressure inside the autoclave increased to 1.8 MPa. In this state, steam was gradually extracted to maintain the pressure at 1.8 MPa, and the reaction was continued for one hour until the internal temperature reached 245° C.

(50) Next, the pressure was reduced over a period of 30 minutes. Subsequently, the inside of the autoclave was held for 10 minutes at a reduced pressure of 650 torr (86.66 kPa) using a vacuum device. At this time, the final internal temperature of the polymerization was 265° C.

(51) Subsequently, the autoclave was pressurized with nitrogen, and the polymer was discharged in a strand-like form through a lower spinneret (nozzle), cooled in water and subjected to cutting to form pellets, and the pellets were then dried at 100° C. under a nitrogen atmosphere for 12 hours to obtain a polyamide. Mw was 20,000, Mw/Mn was 2.0, VR was 12, Mw/VR was 1,667, and the proportion of isophthalic acid among the dicarboxylic acid units was 100 mol %.

(52) (1B-5: Polyamide 6I/6T)

(53) The polyamide polymerization reaction was performed by a “hot melt polymerization method” in the manner described below.

(54) First, 1,200 g of an equimolar salt of isophthalic acid and hexamethylenediamine, 300 g of an equimolar salt of terephthalic acid and hexamethylenediamine, and a 1.5 mol % excess of adipic acid relative to the total of all the equimolar salt components were dissolved in 1,500 g of distilled water to prepare an equimolar 50% by mass homogenous aqueous solution of raw material monomers.

(55) With the solution being stirred at a temperature of 110 to 150° C., steam was gradually extracted and the solution concentration was concentrated to 70% by mass. Subsequently, the internal temperature was raised to 220° C. At this time, the pressure inside the autoclave increased to 1.8 MPa. In this state, steam was gradually extracted to maintain the pressure at 1.8 MPa, and the reaction was continued for one hour until the internal temperature reached 245° C.

(56) Next, the pressure was reduced over a period of 30 minutes. Subsequently, the inside of the autoclave was held for 10 minutes at a reduced pressure of 650 torr (86.66 kPa) using a vacuum device. At this time, the final internal temperature of the polymerization was 265° C.

(57) Subsequently, the autoclave was pressurized with nitrogen, and the polymer was discharged in a strand-like form through a lower spinneret (nozzle), cooled in water and subjected to cutting to form pellets, and the pellets were then dried at 100° C. under a nitrogen atmosphere for 12 hours to obtain a polyamide. Mw was 20,000, Mw/Mn was 2.0, and the proportion of isophthalic acid among the dicarboxylic acid units was 80 mol %.

(58) (B-6: Polyamide 6I/6)

(59) First, 1,400 g of an equimolar salt of isophthalic acid and hexamethylenediamine, 100 g of ε-caprolactam, and a 1.5 mol % excess of adipic acid relative to the total mass of equimolar salt components were dissolved in 1,500 g of distilled water to prepare an equimolar 50% by mass homogenous aqueous solution of raw material monomers.

(60) With the exception of preparing the 50% by mass homogenous aqueous solution of raw material monomers in the above manner, a polyamide polymerization reaction (a “hot melt polymerization method”) was performed using the method described above for the production example of B-2, thus obtaining pellets of a polyamide. Mw was 21,000, and Mw/Mn was 2.0.

(61) [Production of Polyamide Compositions]

Examples 1-1 to 1-8 and Comparative Examples 1-1 to 1-6

(62) Using the above aliphatic polyamides (1A) and semi-aromatic polyamides (1B) in the formulations and proportions shown below in Table 1-1, polyamide compositions were produced in the manner described below.

(63) The polyamides obtained above were dried under a stream of nitrogen to reduce the moisture content to about 0.2% by mass before being used as raw materials for the polyamide compositions.

(64) A twin-screw extruder “ZSK-26MC” manufactured by Coperion GmbH (Germany) was used as the polyamide composition production apparatus.

(65) The twin-screw extruder had an upstream supply port on the first barrel from the upstream side of the extruder, had a downstream first supply port on the sixth barrel, and had a downstream second supply port on the ninth barrel. Further, in the twin-screw extruder, LID was 48, and the number of barrels was 12.

(66) In the twin-screw extruder, the temperature from the upstream supply port to the die was set to the melting point Tm2 of the polyamide (1A) produced in the above production example +20° C., the screw rotational rate was set to 250 rpm, and the discharge rate was set to 25 kg/h.

(67) The aliphatic polyamide (1A) and the semi-aromatic polyamide (1B) were dry-blended using the formulations and proportions shown below in Table 1-1 and then supplied to the upstream supply port of the twin-screw extruder, and the melt-kneaded product extruded from the die head was cooled in a strand-like form and then pelletized to obtain pellets of a polyamide composition (containing no glass fiber).

(68) Next is a description of the case in which a polyamide composition containing 60% by mass of the GF shown in Table 1-1 (polyamides: GF=100 parts by mass: 150 parts by mass) is produced. The aliphatic polyamide (1A) and the semi-aromatic polyamide (1B) were dry-blended and then supplied to the upstream supply port of the twin-screw extruder, the glass fiber was supplied as an inorganic filler from the downstream first supply port of the twin-screw extruder, and the melt-kneaded product extruded from the die head was cooled in a strand-like form and then pelletized to obtain pellets of a polyamide composition (containing glass fiber).

(69) The obtained pellets of the polyamide composition were dried under a stream of nitrogen to reduce the moisture content within the polyamide composition to not more than 500 ppm.

(70) [Measurement Methods for Polyamide Compositions]

(71) Using the polyamide compositions for which the moisture content had been adjusted, each of the following evaluations was performed. The evaluation results are shown below in Table 1-1.

(72) (Calculation of Mol % of Aromatic Dicarboxylic Acid Units)

(73) The mol % of aromatic dicarboxylic acid units was determined by calculation using the following formula.
Formula: Aromatic dicarboxylic acid units=(number of moles of aromatic dicarboxylic acid added as raw material monomer/number of moles of all dicarboxylic acids added as raw material monomers)×100
(1) Melting Peak Temperature Tm2 (Melting Point), Crystallization Peak Temperature Tc, and Crystallization Enthalpy

(74) These values were measured using a Diamond-DSC device manufactured by PerkinElmer, Inc., in accordance with JIS-K7121. Specifically, measurements were performed in the following manner.

(75) First, under a nitrogen atmosphere, a sample of about 10 mg was heated from room temperature to a temperature of 300 to 350° C., depending on the melting point of the sample, at a rate of temperature increase of 20° C./min. The highest peak temperature of the endothermic peak (melting peak) that appeared during this process was recorded as Tm1 (° C.). Next, the temperature was maintained at the maximum heating temperature for two minutes. At this maximum temperature, the polyamides existed in a melted state. Subsequently, the sample was cooled to 30° C. at a rate of temperature reduction of 20° C./min. The exothermic peak that appeared during this process was deemed the crystallization peak, the crystallization peak temperature was recorded as Tc, and the surface area of the crystallization peak was deemed the crystallization enthalpy ΔH (J/g). Subsequently, the sample was held at 30° C. for two minutes, and was then heated from 30° C. to a temperature of 280 to 300° C., depending on the melting point of the sample, at a rate of temperature increase of 20° C./min. The highest peak temperature of the endothermic peak (melting peak) that appeared during this process was deemed the melting point Tm2 (° C.).

(76) (2) Tan δ Peak Temperature

(77) Using a viscoelasticity measuring and analysis device (DVE-V4, manufactured by Rheology Co., Ltd.), a temperature variance spectrum of the dynamic viscoelasticity of a test piece prepared by cutting the parallel portion of a Type L test piece prescribed in ASTM D1822 into a short strip was measured under the conditions described below. The dimensions of the test piece were 3.1 mm (width)×2.9 mm (thickness)×15 mm (length: distance between clamps).

(78) Measurement mode: tensile, waveform: sine wave, frequency: 3.5 Hz, temperature range: 0° C. to 180° C., temperature increase steps: 2° C./min, static load: 400 g, displacement amplitude: 0.75 μm. The ratio E2/E1 between the storage modulus E1 and the loss modulus E2 was recorded as tan δ, and the highest temperature was deemed the tan δ peak temperature.

(79) (3) Mw (Weight Average Molecular Weight), Mn (Number Average Molecular Weight), Molecular Weight Distribution Mw/Mn, Mw(1A)−Mw(1B)

(80) The Mw (weight average molecular weight) and Mn (number average molecular weight) were measured by GPC (gel permeation chromatography using an HLC-8020 device manufactured by Tosoh Corporation, using hexafluoroisopropanol solvent and calculated against PMMA (polymethyl methacrylate) standard samples (manufactured by Polymer Laboratories Ltd.)). Based on these values, Mw(1A)−Mw(1B) and the molecular weight distribution Mw/Mn were calculated. The amount (% by mass) of compounds having a number average molecular weight Mn of at least 500 but not more than 2,000 was calculated from the elution curve (vertical axis: signal strength obtained from detector, horizontal axis: elution time) of each sample obtained using GPC, based on the surface area of the region bounded by the baseline and the elution curve for number average molecular weights from at least 500 to less than 2,000, and the surface area of the entire region bounded by the baseline and the elution curve.

(81) (4) [NH.sub.2]/([NH.sub.2]+[COOH])

(82) Based on the amount of amino ends ([NH.sub.2]) and the amount of carboxyl ends ([COOH]) measured in accordance with (4-1) and (4-2) described below, the value of [NH.sub.2]/([NH.sub.2]+[COOH]) was calculated.

(83) (4-1) Amount of Amino Ends ([NH.sub.2])

(84) The amount of amino ends bonded to polymer ends of the polyamide composition was measured by a neutralization titration in the manner described below.

(85) First, 3.0 g of the polyamide composition was dissolved in 100 mL of a 90% by mass aqueous solution of phenol, and using the thus obtained solution, a titration was performed with 0.025 N hydrochloric acid to determine the amount of amino ends (μeq/g). The end point was determined using the reading from a pH meter.

(86) (4-2) Amount of Carboxyl Ends ([COOH])

(87) The amount of carboxyl ends bonded to polymer ends of the polyamide composition was measured by a neutralization titration in the manner described below.

(88) First, 4.0 g of the polyamide composition was dissolved in 50 mL of benzyl alcohol, and using the thus obtained solution, a titration was performed with 0.1 N NaOH to determine the amount of carboxyl ends (μeq/g). The end point was determined by the change in color of a phenolphthalein indicator.

(89) Measurement of [NH.sub.2]+[COOH] by NMR

(90) The amount of polyamide carboxyl ends and amino ends in the polyamide composition or the semi-aromatic polyamide was quantified by 1H-NMR in the manner described below.

(91) First, 15 mg of the polyamide composition or the semi-aromatic polyamide was dissolved in 0.7 g of deuterated sulfuric acid and 0.7 g of deuterated hexafluoroisopropanol, and after standing overnight, the obtained solution was used to measure the polyamide ends by 1H-NMR.

(92) Based on the ratio between the surface area of the peak at 2.47 ppm derived from the methylene hydrogens adjacent to adipic acid, the surface area of the peak at 8.07 ppm derived from the hydrogens on the benzene ring carbons adjacent to the isophthalic acid groups, and the peak at 7.85 ppm derived from the hydrogens on the benzene ring carbons adjacent to the terephthalic acid groups, the amount of carboxyl ends was determined. Based on the ratio of the peak at 2.67 to 2.69 ppm derived from methylene carbon hydrogens adjacent to a hexamethylenediamine group, the amount of amino ends was determined. The 1H-NMR analyses were conducted using a nuclear magnetic resonance analysis apparatus JNM ECA-500 manufactured by JEOL Ltd., and the above amounts were determined by calculating integral ratios.

(93) Based on the amount of amino ends ([NH.sub.2]) and the amount of carboxyl ends ([COOH]) measured above, the value of [NH.sub.2]+[COOH] was calculated.

(94) (6) Tensile Strength

(95) Using an injection molding machine [PS-40E, manufactured by Nissei Plastic Industrial Co., Ltd.], molded pieces of the multipurpose test piece type A were molded in accordance with ISO 3167. The specific molding conditions included an injection+holding time of 25 seconds, a cooling time of 15 seconds, a mold temperature of 80° C., and a melted resin temperature set to the high temperature-side melting peak temperature (Tm2) for the polyamides+20° C.

(96) Using the thus obtained molded piece of multipurpose test piece type A, a tensile test was performed in accordance with ISO 527 under conditions including temperature conditions of 23° C. and a tension rate of 50 mm/min, thereby measuring the tensile yield stress, which was recorded as the tensile strength.

(97) Further, with the temperature conditions set to 80° C. and the remaining conditions as described above, the tensile strength at 80° C. was also measured.

(98) (7) Corrosion Resistance

(99) The sample pellets and carbon steel (SUS400) for which the weight had been measured were placed in a sealed container made of SUS, and the inside of the container was flushed with nitrogen. Subsequently, the sealed container was heated, the internal temperature was held at 300° C. for 6 hours, and following cooling, the weight of the carbon steel was measured. The degree of corrosion was determined on the basis of the change in weight of the carbon steel.

(100) (Evaluation Criteria)

(101) A: no weight reduction from before to after test

(102) B: weight reduction from before to after test of at least 0.1 g but less than 0.5 g

(103) C: weight reduction from before to after test of at least 0.5 g but less than 1 g

(104) D: weight reduction from before to after test of 1 g or more

(105) (8) Surface Gloss

(106) A flat plate molded piece was produced in the following manner.

(107) Using an injection molding machine [NEX50III-5EG, manufactured by Nissei Plastic Industrial Co., Ltd.] with the cooling time set to 25 seconds, the screw rotational rate set to 200 rpm, the mold temperature set to the tan δ peak temperature+5° C., and the cylinder temperature set to (Tm2+10°) C to (Tm2+30°) C, the injection pressure and injection speed were adjusted appropriately to achieve a fill time of 1.6+0.1 seconds, and a flat plate molded piece (6 cm×9 cm, thickness: 2 mm) was produced.

(108) The 60° gloss of the central portion of the flat plate molded piece prepared in this manner was measured in accordance with JIS-K7150 using a gloss meter (1G320, manufactured by Horiba, Ltd.).

(109) A larger measured value was adjudged to indicate more superior surface appearance.

(110) (9) MD (Mold Deposits) During Molding

(111) The molding described above in (8) was repeated for 100 consecutive shots, and following completion of the molding, the gas vent was inspected visually.

(112) The evaluation criteria for gas generation during molding were as listed below. The ability to obtain molded articles without problems was evaluated as leading to an improvement in productivity.

(113) (Evaluation Criteria)

(114) A: no deposits observed on gas vent

(115) B: some deposits observed on gas vent

(116) C: deposits observed on gas vent, with a blockage beginning to occur

(117) D: deposits observed on gas vent, with vent blocked

(118) (10) Flexural Modulus Retention Ratio after Water Absorption

(119) An ISO dumbbell with a thickness of 4 mm was prepared and used as a test piece. Using the obtained test piece, the flexural modulus was measured in accordance with ISO 178. Further, the ISO dumbbell was left to stand in a constant-temperature constant-humidity (23° C., 50% RH) environment, and once water absorption equilibrium had been reached, the flexural modulus was again measured in accordance with ISO 178. The flexural modulus retention ratio after water absorption was determined using the following formula.
Flexural modulus retention ratio after water absorption (%)=flexural modulus after water absorption/flexural modulus before water absorption×100

(120) TABLE-US-00001 TABLE 1-1 Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- ple ple ple ple ple ple ple ple ple Type Units 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 Polyamide 1A-1 parts 70 95 60 55 70 70 (1A) by mass 1A-2 parts 70 by mass 1A-3 parts 70 70 by mass Polyamide 1B-1 parts (1B) by mass 1B-2 parts 30 5 40 45 30 30 30 by mass 1B-3 parts by mass 1B-4 parts by mass 1B-5 parts 30 by mass 1B-6 parts 30 by mass Additive 1D-1 parts 0.5 (1D) by mass Polyamide Mw 32,000 34,250 29,000 28,250 34,000 27,000 22,000 32,000 33,000 composition Mw(1A) − 15,000 15,000 15,000 15,000 20,000 10,000 10,000 0 0 physical Mw(1B) properties Mn 500 to 2000 % 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6 Mw/Mn 2.1 2.1 2.1 2.1 2.1 2.1 2.1 2.1 2.0 [NH.sub.2]/([NH.sub.2] + 0.30 0.33 0.34 0.35 0.32 0.32 0.35 0.30 0.35 [COOH]) [NH.sub.2] + [COOH] μeq/g 116 91 126 131 107 119 125 109 108 Tensile strength MPa 92 85 94 96 92 92 88 92 89 Corrosion A A A A A A A A A resistance Polyamide Tm2 ° C. 257 262 255 254 257 257 257 257 251 composition Tc ° C. 210 225 205 203 210 210 213 210 200 (GF: 60% Crystallization J/g 21.0 24.3 18.1 15.1 21.0 21.0 21.4 19.0 20.3 by mass) enthalpy physical tan δ peak ° C. 111 93 119 123 110 113 115 108 107 properties temperature Surface gloss % 61 53 67 73 55 65 71 61 66 MD during A A A A A A A A A molding Flexural modulus % 100 85 100 100 100 100 100 98 99 retention ratio after water absorption Tensile strength MPa 273 251 275 277 269 275 278 269 275 80° C. tensile MPa 162 154 159 153 162 163 163 158 156 strength Comparative Comparative Comparative Comparative Comparative Comparative Type Units Example 1-1 Example 1-2 Example 1-3 Example 1-4 Example 1-5 Example 1-6 Polyamide 1A-1 parts 100 70 70 45 (1A) by mass 1A-2 parts 85 by mass 1A-3 parts by mass Polyamide 1B-1 parts 100 (1B) by mass 1B-2 parts 55 15 by mass 1B-3 parts 30 by mass 1B-4 parts 30 by mass 1B-5 parts by mass 1B-6 parts by mass Additive 1D-1 parts (1D) by mass Polyamide Mw 34,500 31,000 38,000 37,000 26,750 37,300 composition Mw(1A) − — — −9,000 8,000 15,000 20,000 physical Mw(1B) properties Mn 500 to 2000 % 1.2 1.0 1.2 1.3 1.6 1.6 Mw/Mn 2.0 2.0 2.5 2.4 2.1 2.1 [NH.sub.2]/([NH.sub.2] + 0.38 0.22 0.45 0.45 0.34 0.35 [COOH]) [NH.sub.2] + [COOH] μeq/g 86 94 93 89 141 98 Tensile strength MPa 83 79 105 97 75 85 Corrosion A C A A A A resistance Polyamide Tm2 ° C. 262 239 257 259 251 260 composition Tc ° C. 230 184 210 217 196 215 (GF: 60% Crystallization J/g 26.0 17.5 20.3 20.5 12.0 20.0 by mass) enthalpy physical tan δ peak ° C. 80 100 106 109 130 101 properties temperature Surface gloss % 45 63 45 37 66 47 MD during A A B B A A molding Flexural modulus % 67 81 97 92 100 100 retention ratio after water absorption Tensile strength MPa 240 269 251 261 233 249 80° C. tensile MPa 150 119 145 147 113 155 strength

(121) As illustrated in Table 1-1, in Examples 1-1 to 1-9 in which a polyamide composition of an aspect described above was molded, the polyamide composition containing 50 to 99 parts by mass of an aliphatic polyamide (1A) and 1 to 50 parts by mass of a semi-aromatic polyamide (1B) containing a dicarboxylic acid unit that included at least 75 mol % of isophthalic acid and a diamine unit that included at least 50 mol % of a diamine of 4 to 10 carbon atoms, wherein the tan δ peak temperature of the polyamide composition was at least 90° C., and the weight average molecular weight Mw of the polyamide composition satisfied 15,000≤Mw≤35,000, the surface appearance, the degree of MD during retention, and the flexural modulus retention ratio after water absorption were particularly superior compared with Comparative Example 1-1 which used only a PA66, Comparative Example 1-2 which used a copolymer of a PA66 and a PA6I, Comparative Example 1-3 which used a mixture of a PA66 and a polyamide 6I (Mw=44,000), but in which the weight average molecular weight Mw of the composition exceeded 35,000, Comparative Example 1-4 which used a mixture of a polyamide 66 and a copolymer of a polyamide 6I and a polyamide 6T (6I/6T), but in which the weight average molecular weight Mw of the composition exceeded 35,000, Comparative Example 1-5 which contained less than 50 parts by mass of the aliphatic polyamide, and Comparative Example 1-6 in which the weight average molecular weight Mw of the composition exceeded 35,000.

Examples 2-1 to 2-4, Comparative Examples 2-1 to 2-7

(122) (Constituent Components)

(123) [(2A) Aliphatic Polyamides]

(124) 2A-1: a polyamide 66 (the same polyamide as 1A-1 above was used)

(125) 2A-2: a polyamide 6 (SF1013A manufactured by Ube Industries, Ltd.)

(126) [(2B) Semi-Aromatic Polyamides]

(127) 2B-1: a polyamide 6I (the same polyamide as 1B-2 above was used)

(128) 2B-2: a polyamide 6I (T40 manufactured by Lanxess AG, Mw=44,000, Mw/Mn=2.8, VR31, Mw/VR=1,419)

(129) 2B-3: a polyamide 6I/6T (G21 manufactured by Ems Group, Mw=27,000, Mw/Mn=2.2, Mw/VR=1,000, VR27, Mw/VR=1,000, proportion of isophthalic acid in dicarboxylic acid units: 70 mol %)

(130) 2B-4: a polyamide 6I (high molecular weight)

(131) 2B-5: a polyamide 66/6I (the same polyamide as 1B-1 above was used)

(132) [(2C) Pigment]

(133) (2C) Zinc sulfide (ZnS) (SACHTOLITH HD-S) was used.

(134) [(2D1) Flame Retardant]

(135) (2D1) A brominated polystyrene (product name “SAYTEX (a registered trademark) HP-7010G” manufactured by Albemarle Corporation (bromine content as determined by elemental analysis: 63% by mass)) was used.

(136) [(2D2) Flame Retardant Auxiliary]

(137) (2D2) Diantimony trioxide (product name “Antimony Trioxide” manufactured by Daiichi F. R. co., Ltd.) was used.

(138) [(2E) Polymer Containing an α,β-Unsaturated Dicarboxylic Acid Anhydride as Structural Unit]

(139) (2E) A maleic anhydride-modified polyphenylene ether was used.

(140) [(2F) Filler]

(141) (2F) Glass fiber (GF) (product name “ECS03T275H” manufactured by Nippon Electric Glass Co., Ltd., average fiber diameter: 10 μmφ, cut length: 3 mm) was used.

(142) [Production of Polyamides]

(143) Next is a description of the methods used for producing the semi-aromatic polyamide (2B) (2B-4) and the polymer (2E) containing an α,β-unsaturated dicarboxylic acid anhydride as a structural unit.

(144) (2B-4: Polyamide 6I)

(145) The polyamide polymerization reaction was performed by a “hot melt polymerization method” in the manner described below.

(146) First, 1,500 g of an equimolar salt of isophthalic acid and hexamethylenediamine and a 1.0 mol % excess of adipic acid relative to the total mass of the equimolar salt component were dissolved in 1,500 g of distilled water to prepare an equimolar 50% by mass homogenous aqueous solution of raw material monomers.

(147) With the solution being stirred at a temperature of 110 to 150° C., steam was gradually extracted and the solution concentration was concentrated to 70% by mass. Subsequently, the internal temperature was raised to 220° C. At this time, the pressure inside the autoclave increased to 1.8 MPa. In this state, steam was gradually extracted to maintain the pressure at 1.8 MPa, and the reaction was continued for one hour until the internal temperature reached 245° C.

(148) Next, the pressure was reduced over a period of 30 minutes. Subsequently, the inside of the autoclave was held for 10 minutes at a reduced pressure of 650 torr (86.66 kPa) using a vacuum device. At this time, the final internal temperature of the polymerization was 265° C.

(149) Subsequently, the autoclave was pressurized with nitrogen, and the polymer was discharged in a strand-like form through a lower spinneret (nozzle), cooled in water and subjected to cutting to form pellets, and the pellets were then dried at 100° C. under a nitrogen atmosphere for 12 hours to obtain a polyamide. Mw was 25,000, Mw/Mn was 2.1, VR was 16, Mw/VR was 1,563, and the proportion of isophthalic acid among the dicarboxylic acid units was 100 mol %.

(150) (2E: Maleic Anhydride-Modified Polyphenylene Ether)

(151) One hundred parts by mass of a poly(2,6-dimethyl-1,4-phenylene ether) (hereafter abbreviated as “the polyphenylene ether”) having a reduced viscosity (measured in a 0.5 g/dl chloroform solution at 30° C.) of 0.52 obtained by oxidative polymerization of 2,6-dimethylphenol and 1.0 parts by mass of maleic anhydride as a compatibilizer were supplied to a twin-screw extruder (ZSK-40, manufactured by Werner & Pfleiderer GmbH) having supply ports at a single upstream location (hereafter abbreviated as “top-F”) and two other locations in the central portion of the extruder and a downstream location close to the die (hereafter the location in the central portion of the extruder is abbreviated as “side-1” and the downstream location near the die is abbreviated as “side-2”), with a dry blend of the polyphenylene ether and the maleic anhydride supplied from top-F, with side-1 and side-2 closed, under conditions including a cylinder set temperature of 320° C., a screw rotational rate of 300 rpm, and a discharge rate of 20.15 kg/hr, and following melt kneading, the polymer was discharged in a strand-like form, cooled in a strand bath (water bath) and pelletized using a cutter, thus obtaining pellets of a maleic anhydride-modified polyphenylene ether.

(152) [Production of Polyamide Compositions]

(153) Using the above aliphatic polyamide (2A) and semi-aromatic polyamides (2B) in the formulations and proportions shown below in Table 2-1, polyamide compositions were produced in the manner described below.

(154) The polyamides obtained above were dried under a stream of nitrogen to reduce the moisture content to about 0.2% by mass before being used as raw materials for the polyamide compositions.

(155) Melt kneading was performed in accordance with the method of the examples described below to obtain pellets of the polyamide composition. The obtained pellets of the polyamide composition were dried under a stream of nitrogen to reduce the moisture content within the polyamide composition to not more than 500 ppm.

(156) [Measurement Methods for Physical Properties of Polyamide Compositions]

(157) Using the polyamide compositions for which the moisture content had been adjusted, each of the following evaluations was performed. The evaluation results are shown below in Table 2-1.

(158) <Tan δ Peak Temperature>

(159) Using a PS40E injection molding machine manufactured by Nissei Plastic Industrial Co., Ltd., with the cylinder temperature set to 290° C. and the mold temperature set to 100° C., a molded body was molded in accordance with JIS-K7139 under injection conditions including an injection time of 10 seconds and a cooling time of 10 seconds. This molded body was measured under the following conditions using a dynamic viscoelasticity evaluation device (EPLEXOR 500N, manufactured by Gabo GmbH). Measurement mode: tensile, measurement frequency: 8.00 Hz, rate of temperature increase: 3° C./min, temperature range: −100 to 250° C. The ratio E2/E1 between the storage modulus E1 and the loss modulus E2 was recorded as tan δ, and the highest temperature was deemed the tan δ peak temperature.

(160) <Molecular Weight and Ends of Polyamides>

(161) (Polyamide Molecular Weight (Mn, Mw/Mn))

(162) The Mw (weight average molecular weight)/Mn (number average molecular weight) values of the polyamides obtained in the examples and comparative examples were calculated using the values for Mw and Mn measured by GPC (gel permeation chromatography using an HLC-8020 device manufactured by Tosoh Corporation, using hexafluoroisopropanol solvent and calculated against PMMA (polymethyl methacrylate) standard samples (manufactured by Polymer Laboratories Ltd.)). For the GPC columns, TSKgel GMHHR-M and G1000HHR columns were used.

(163) (Amount of Amino Ends ([NH2]))

(164) In the polyamides obtained in the examples and comparative examples, the amount of amino ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(165) First, 3.0 g of the polyamide was dissolved in 100 mL of a 90% by mass aqueous solution of phenol, and using the thus obtained solution, a titration was performed with 0.025 N hydrochloric acid to determine the amount of amino ends (μeq/g). The end point was determined using the reading from a pH meter.

(166) (Amount of Carboxyl Ends ([COOH]))

(167) In the polyamides obtained in the examples and comparative examples, the amount of carboxyl ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(168) First, 4.0 g of the polyamide was dissolved in 50 mL of benzyl alcohol, and using the thus obtained solution, a titration was performed with 0.1 N NaOH to determine the amount of carboxyl ends (μeq/g). The end point was determined by the change in color of a phenolphthalein indicator.

(169) Based on the amount of amino ends ([NH.sub.2]) and the amount of carboxyl ends ([COOH]) measured above, the total amount of active ends ([NH.sub.2]+[COOH]) and the ratio of the amount of amino ends relative to the total amount of active ends ([NH.sub.2]/[(NH.sub.2]+[COOH])) were calculated.

(170) <Formic Acid Solution Viscosity VR>

(171) The polyamide was dissolved in formic acid, and the viscosity was measured in accordance with JIS K6810.

(172) <Evaluation of Moldability and External Appearance>

(173) An “FN3000” apparatus manufactured by Nissei Plastic Industrial Co., Ltd. was used.

(174) With the cylinder temperature set to 290° C. and the mold temperature set to 100° C., molding was conducted for 100 shots using the polyamide resin composition under injection molding conditions including an injection time of 10 seconds and a cooling time of 10 seconds, thus obtaining molded bodies (ISO test pieces).

(175) The moldability was evaluated on the basis of the mold releasability following molding, and a case in which the proportion of molded bodies that stuck to the mold across the 100 shots was 10% or less was evaluated as A, a proportion of greater than 10% but not more than 20% was evaluated as B, a proportion of greater than 20% but not more than 50% was evaluated as C, and a proportion exceeding 50% was evaluated as D.

(176) Further, in terms of the external appearance of the obtained molded bodies, a surface gloss of 60 or higher was evaluated as A, a surface gloss of at least 55 but not more than 59 was evaluated as B, a surface gloss of at least 50 but not more than 54 was evaluated as C, and a surface gloss lower than 50 was evaluated as D.

(177) <Evaluation of Flame Retardancy>

(178) Measurements were performed using the method UL94 (a standard prescribed by Underwriters Laboratories Inc., USA). The test piece (length: 127 mm, width: 12.7 mm, thickness: 1.6 mm) was prepared by fitting a mold for the UL test piece (mold temperature=100° C.) to an injection molding machine (PS40E manufactured by Nissei Plastic Industrial Co., Ltd.) and molding the polyamide resin composition at a cylinder temperature of 290° C. The injection pressure was set to a value of the complete filling pressure when molding the UL test piece+2%. The flame retardancy classifications used were those prescribed in the UL94 standard (vertical flame test).

(179) <Weld Strength>

(180) A test piece was obtained by conducting molding using an injection molding machine (PS40E manufactured by Nissei Plastic Industrial Co., Ltd.) fitted with a mold having a shape with dimensions of length: 127 mm, width: 12.7 mm and thickness: 1.6 mm, wherein the melted resin was injected from both lengthwise ends of the mold so as to form a weld in the central portion of the lengthwise direction. This molded test piece was subjected to a tensile test using the method prescribed in ASTM D638, with the exception of altering the chuck separation distance to 50 mm and the tension rate to 50 mm/min, thus determining the tensile strength. Further, the test piece was left to stand in a constant-temperature constant-humidity (23° C., 50% RH) environment, and once water absorption equilibrium had been reached, the tensile strength was again measured using the method prescribed in ASTM D638. The tensile strength retention ratio after water absorption was determined using the following formula.

(181) Tensile strength retention ratio after water absorption (%)=tensile strength after water absorption/tensile strength before water absorption×100

(182) <Rockwell Hardness>

(183) An “FN3000” apparatus manufactured by Nissei Plastic Industrial Co., Ltd. was used.

(184) With the cylinder temperature set to 290° C. and the mold temperature set to 100° C., molding was conducted using the polyamide resin composition under injection molding conditions including an injection time of 10 seconds and a cooling time of 10 seconds, thus obtaining a molded body (ISO test piece). The Rockwell hardness (M scale) was measured using a hardness meter (ARK-F3000 manufactured by Akashi Seisakusho, Ltd.). Further, the test piece was left to stand in a constant-temperature constant-humidity (23° C., 50% RH) environment, and once water absorption equilibrium had been reached, the Rockwell hardness was again measured. The Rockwell hardness retention ratio after water absorption was determined using the following formula.
Rockwell hardness retention ratio after water absorption (%)=Rockwell hardness after water absorption/Rockwell hardness before water absorption×100

Example 2-1

(185) Using a TEM 35 mm twin-screw extruder manufactured by Toshiba Machine Co., Ltd. (temperature setting: front 280° C., screw rotational rate: 300 rpm), a mixture obtained by blending the polyamides (2A-1) and (2B-1), the pigment (2C), the flame retardant (2D1), the flame retardant auxiliary (2D2) and the polymer (2E) containing an α,β-unsaturated dicarboxylic acid anhydride as a structural unit was supplied to a top feed port provided in the most upstream portion of the extruder, the filler (2F) was supplied from a side feed port on the downstream side of the extruder (at a point where the resins supplied from the top feed port had reached a satisfactorily melted state), and the melt kneaded product extruded from the die head was cooled in a strand-like state and then pelletized to obtain pellets of the polyamide resin composition. The blend amounts were 17.5% by mass for the polyamide (2A-1), 9.5% by mass for the polyamide (2B-1), 2.0% by mass for the pigment (2C), 10.5% by mass for the flame retardant (2D1), 2.0% by mass for the flame retardant auxiliary (2D2), 3.5% by mass for the polymer (2E) containing an α,β-unsaturated dicarboxylic acid anhydride as a structural unit, and 55% by mass for the filler (2F).

(186) Further, using the thus obtained polyamide resin composition, molded articles were produced using the methods described above, and evaluations of the moldability during molding, the external appearance, the weld strength, the Rockwell hardness and the flame retardancy were performed. The evaluation results are shown below in Table 2-1.

Example 2-2

(187) With the exception of altering the blend amounts to include 16.2% by mass of the polyamide (2A-1) and 10.8% by mass of the polyamide (2B-1), production and evaluation were performed in the same manner as Example 2-1.

Example 2-3

(188) With the exception of altering the blend amounts to include 16.5% by mass of the polyamide (2A-1), 11.0% by mass of the polyamide (2B-4), and 10.0% by mass of the flame retardant (2D1), production and evaluation were performed in the same manner as Example 2-1.

Example 2-4

(189) With the exception of altering the blend amounts to include 14.8% by mass of the polyamide (2A-1) and 12.2% by mass of the polyamide (2B-1), production and evaluation were performed in the same manner as Example 2-1.

Comparative Example 2-1

(190) With the exception of altering the blend amounts to include 27.5% by mass of the polyamide (2A-1), 0% by mass of the polyamide (2B-1), and 10.0% by mass of the flame retardant (2D1), production and evaluation were performed in the same manner as Example 2-1.

Comparative Example 2-2

(191) With the exception of altering the blend amounts to include 0% by mass of the polyamide (2A-1), 27.5% by mass of the polyamide (2B-1), and 10.0% by mass of the flame retardant (2D1), production and evaluation were performed in the same manner as Example 2-1.

Comparative Example 2-3

(192) With the exception of altering the blend amounts to include 0% by mass of the polyamide (2A-1), 22.5% by mass of the polyamide (2B-5), and 15.0% by mass of the flame retardant (2D1), production and evaluation were performed in the same manner as Example 2-1.

Comparative Example 2-4

(193) With the exception of altering the blend amounts to include 22.0% by mass of the polyamide (2A-1), 9.5% by mass of the polyamide (2B-2), and 6.0% by mass of the flame retardant (2D1), production and evaluation were performed in the same manner as Example 2-1.

Comparative Example 2-5

(194) With the exception of altering the blend amounts to include 18.4% by mass of the polyamide (2A-1), 12.1% by mass of the polyamide (2B-2), and 0% by mass of the polymer (2E) containing an α,β-unsaturated dicarboxylic acid anhydride as a structural unit, production and evaluation were performed in the same manner as Example 2-1.

Comparative Example 2-6

(195) With the exception of altering the blend amounts to include 20.0% by mass of the polyamide (2A-1), 8.5% by mass of the polyamide (2B-3), and 9.0% by mass of the flame retardant (2D1), production and evaluation were performed in the same manner as Example 2-1.

Comparative Example 2-7

(196) With the exception of altering the blend amounts to include 20.0% by mass of the polyamide (2A-2), 8.5% by mass of the polyamide (2B-3), and 9.0% by mass of the flame retardant (2D1), production and evaluation were performed in the same manner as Example 2-1.

(197) TABLE-US-00002 TABLE 2-1 Example Example Example Example Comparative Comparative Type Units 2-1 2-2 2-3 2-4 Example 2-1 Example 2-2 Aliphatic polyamide (2A) 2A-1 % by mass 17.5 16.2 16.5 14.8 27.5 2A-2 % by mass Semi-aromatic polyamide (2B) 2B-1 % by mass 9.5 10.8 12.2 27.5 2B-2 % by mass 2B-3 % by mass 2B-4 % by mass 11.0 2B-5 % by mass Pigment (2C) ZnS % by mass 2.0 2.0 2.0 2.0 2.0 2.0 Flame retardant (2D1) Br—PS % by mass 10.5 10.5 10.0 10.5 10.0 10.0 Flame retardant auxiliary (2D2) Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 2.0 Polymer (2E) containing an Maleic anhydride- % by mass 3.5 35 3.5 3.5 3.5 3.5 α,β-unsaturated modified dicarboxylic acid anhydride polyphenylene as a structural unit ether Filler (2F) GF % by mass 55.0 55.0 55.0 55.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 100.0 PA physical properties tan δ peak temperature ° C. 111 115 115 115 60 135 in composition Mw g/mol 29,750 29,000 30,600 28,250 35,000 20,000 Mw(2A) − Mw(2B) g/mol 15,000 15,000 11,000 15,000 — — Mn 500 to 2000 % by mass 1.6 1.7 1.7 1.8 1.2 2.0 Mw/Mn 2.1 2.1 2.1 2.1 2.0 2.0 [NH.sub.2]/([NH.sub.2] + 0.33 0.32 0.32 0.32 0.38 0.24 [COOH]) moldability A A A A A D external appearance A A A A D A flame retardancy UL94 V-0 V-0 V-0 V-0 V-2 V-0 (1.6 mm) weld strength (dry) MPa 71 64 64 62 90 60 weld strength (wet) MPa 61 58 58 60 45 50 weld strength (retention % 86 91 91 97 50 83 ratio) Rockwell hardness (dry) 100 101 101 102 100 103 Rockwell hardness (wet) 99 101 101 102 70 103 Rockwell hardness % 99 100 100 100 70 100 (retention ratio) Comparative Comparative Comparative Comparative Comparative Type Units Example 2-3 Example 2-4 Example 2-5 Example 2-6 Example 2-7 Aliphatic polyamide (2A) 2A-1 % by mass 22.0 18.4 20.0 2A-2 % by mass 20.0 Semi-aromatic polyamide (2B) 2B-1 % by mass 2B-2 % by mass 9.5 12.1 2B-3 % by mass 8.5 8.5 2B-4 % by mass 2B-5 % by mass 22.5 Pigment (2C) ZnS % by mass 2.0 2.0 2.0 2.0 2.0 Flame retardant (2D1) Br—PS % by mass 15.0 6.0 10.5 9.0 9.0 Flame retardant auxiliary (2D2) Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 Polymer (2E) containing an Maleic anhydride- % by mass 3.5 3.5 0.0 3.5 3.5 α,β-unsaturated modified dicarboxylic acid anhydride polyphenylene as a structural unit ether Filler (2F) GF % by mass 55.0 55.0 55.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 PA physical properties tan δ peak temperature ° C. 100 106 110 109 106 in composition Mw g/mol 32,000 40,800 42,000 50,000 28,860 Mw(2A) − Mw(2B) g/mol — −8,600 −8,600 8,400 −600 Mn 500 to 2000 % by mass 1.0 1.2 1.2 1.4 1.6 Mw/Mn 2.0 2.4 2.4 2.4 2.2 [NH.sub.2]/([NH.sub.2] + 0.22 0.45 0.46 0.45 0.45 [COOH]) moldability B A A A A external appearance A C C C A flame retardancy UL94 V-0 V-1 V-1 V-1 V-1 (1.6 mm) weld strength (dry) MPa 63 71 55 73 63 weld strength (wet) MPa 38 56 45 58 48 weld strength (retention % 60 79 82 79 76 ratio) Rockwell hardness (dry) 100 100 101 100 90 Rockwell hardness (wet) 92 98 101 98 80 Rockwell hardness % 92 98 100 98 89 (retention ratio)

(198) As is evident from the results shown in Table 2-1, in each of the polyamide compositions of the present invention, the dicarboxylic acid units of the semi-aromatic polyamide (2B) included at least 75 mol % of isophthalic acid, and therefore the tan δ peak temperature of the polyamide composition increased. As a result, the molded articles of the polyamide compositions of Examples 2-1 to 2-4 had excellent flame retardancy, as well as superior weld strength and Rockwell hardness. Furthermore, because the weight average molecular weight Mw of the polyamide composition was within the range 10,000≤Mw≤40,000, excellent moldability and external appearance were obtained in addition to the above properties.

(199) In contrast, Comparative Example 2-1 did not contain the semi-aromatic polyamide (2B), and in Comparative Examples 2-3, 2-6 and 2-7, the dicarboxylic acid units of the semi-aromatic polyamide (2B) included less than 75 mol % of isophthalic acid, and therefore the molded articles of the polyamide compositions exhibited unsatisfactory flame retardancy, weld strength, Rockwell hardness, moldability and external appearance.

(200) In Comparative Example 2-2, although the dicarboxylic acid units of the semi-aromatic polyamide (2B) included at least 75 mol % of isophthalic acid, because the aliphatic polyamide (2A) was not included, the balance between the external appearance and the flame retardancy, the weld strength and the Rockwell hardness was poor and unsatisfactory. In Comparative Example 2-4, although the dicarboxylic acid units of the semi-aromatic polyamide (2B) included at least 75 mol % of isophthalic acid, because the weight average molecular weight Mw was large, the balance between the external appearance and the flame retardancy, the weld strength and the Rockwell hardness was poor and unsatisfactory. In Comparative Example 2-5, although the dicarboxylic acid units of the semi-aromatic polyamide (2B) included at least 75 mol % of isophthalic acid, because the weight average molecular weight Mw was large and the polymer (2E) containing an α,β-unsaturated dicarboxylic acid anhydride as a structural unit was not included, the balance between the physical properties of the polyamide composition molded articles was unsatisfactory.

Examples 3-1 to 3-7, Comparative Examples 3-1 to 3-9

(201) (Constituent Components)

(202) [(3A) Aliphatic Polyamides]

(203) 3A-1: a polyamide 66 (the same polyamide as 1A-1 above was used)

(204) 3A-2: a polyamide 6 (SF1013A manufactured by Ube Industries, Ltd.), Mw=26,000, Mw/Mn=2.0

(205) [(3B) Semi-Aromatic Polyamides]

(206) 3B-1: a polyamide 6I (the same polyamide as 1B-2 above was used)

(207) 3B-2: a polyamide 6I (T40 manufactured by Lanxess AG, Mw=44,000, Mw/Mn=2.8, VR31, Mw/VR=1,419, proportion of isophthalic acid in dicarboxylic acid units: 100 mol %)

(208) 3B-3: a polyamide 6I/6T (G21 manufactured by Ems Group, Mw=27,000, Mw/Mn=2.2, VR27, Mw/VR=1,000, proportion of isophthalic acid in dicarboxylic acid units: 70 mol %)

(209) 3B-4: a polyamide 6I (high molecular weight) (the same polyamide as 2B-4 above was used)

(210) 3B-5: a polyamide 66/6I (the same polyamide as 1B-1 above was used)

(211) 3B-6: a polyamide MXD6 (T-600, a Toyobo Nylon manufactured by Toyobo Co., Ltd., proportion of isophthalic acid in dicarboxylic acid units: 0 mol %)

(212) [(3C1) Flame Retardant]

(213) (3C1) A brominated polystyrene (product name “SAYTEX (a registered trademark) HP-7010G” manufactured by Albemarle Corporation (bromine content as determined by elemental analysis: 67% by mass)) was used.

(214) [(3C2) Flame Retardant Auxiliary]

(215) (3C2) Diantimony trioxide (product name “Antimony Trioxide” manufactured by Daiichi F. R. co., Ltd.) was used.

(216) [(3D) Polymer Containing an α,β-Unsaturated Dicarboxylic Acid Anhydride as Structural Unit]

(217) (3D) A maleic anhydride-modified polyphenylene ether was used (the same compound as 2E above was used).

(218) [(3E) Filler]

(219) (3E) Glass fiber (GF) (product name “ECS03T275H” manufactured by Nippon Electric Glass Co., Ltd., average fiber diameter: 10 μmφ, cut length: 3 mm) was used.

(220) [Production of Polyamides]

(221) Using the above aliphatic polyamides (3A) and semi-aromatic polyamides (3B) in the formulations and proportions shown below in Table 3-1, polyamide compositions were produced in the manner described below.

(222) The polyamides obtained above were dried under a stream of nitrogen to reduce the moisture content to about 0.2% by mass before being used as raw materials for the polyamide compositions.

(223) Pellets of the polyamide composition were obtained by performing melt kneading using the method described in the example below. The obtained pellets of the polyamide composition were dried under a stream of nitrogen to reduce the moisture content within the polyamide composition to not more than 500 ppm.

(224) [Measurement Methods for Polyamide Compositions]

(225) Using the polyamide compositions for which the moisture content had been adjusted, each of the following evaluations was performed. The evaluation results are shown below in Table 3-1.

(226) <Tan δ Peak Temperature>

(227) Using a PS40E injection molding machine manufactured by Nissei Plastic Industrial Co., Ltd., with the cylinder temperature set to 290° C. and the mold temperature set to 100° C., a molded body was molded in accordance with JIS-K7139 under injection conditions including an injection time of 10 seconds and a cooling time of 10 seconds. This molded body was measured under the following conditions using a dynamic viscoelasticity evaluation device (EPLEXOR 500N, manufactured by Gabo GmbH). Measurement mode: tensile, measurement frequency: 8.00 Hz, rate of temperature increase: 3° C./min, temperature range: −100 to 250° C. The ratio E2/E1 between the storage modulus E1 and the loss modulus E2 was recorded as tan δ, and the highest temperature was deemed the tan δ peak temperature.

(228) <Molecular Weight and Ends of Polyamide Compositions>

(229) (Polyamide Composition Molecular Weight (Mn, Mw/Mn))

(230) The Mw (weight average molecular weight)/Mn (number average molecular weight) values of the polyamide compositions obtained in the examples and comparative examples were calculated using the values for Mw and Mn measured by GPC (gel permeation chromatography using an HLC-8020 device manufactured by Tosoh Corporation, using hexafluoroisopropanol solvent and calculated against PMMA (polymethyl methacrylate) standard samples (manufactured by Polymer Laboratories Ltd.)). For the GPC columns, TSKgel GMHHR-M and G1000HHR columns were used.

(231) (Amount of Amino Ends ([NH.sub.2]))

(232) In the polyamide compositions obtained in the examples and comparative examples, the amount of amino ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(233) First, 3.0 g of the polyamide composition was dissolved in 100 mL of a 90% by mass aqueous solution of phenol, and using the thus obtained solution, a titration was performed with 0.025 N hydrochloric acid to determine the amount of amino ends (μeq/g). The end point was determined using the reading from a pH meter.

(234) (Amount of Carboxyl Ends ([COOH]))

(235) In the polyamide compositions obtained in the examples and comparative examples, the amount of carboxyl ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(236) First, 4.0 g of the polyamide composition was dissolved in 50 mL of benzyl alcohol, and using the thus obtained solution, a titration was performed with 0.1 N NaOH to determine the amount of carboxyl ends (μeq/g). The end point was determined by the change in color of a phenolphthalein indicator.

(237) Based on the amount of amino ends ([NH.sub.2]) and the amount of carboxyl ends ([COOH]) measured above, the total amount of active ends ([NH.sub.2]+[COOH]) and the ratio of the amount of amino ends relative to the total amount of active ends ([NH.sub.2]/[(NH.sub.2]+[COOH])) were calculated.

(238) <Formic Acid Solution Viscosity VR>

(239) The semi-aromatic polyamide (3B) was dissolved in formic acid, and the viscosity was measured in accordance with ASTM-D789.

(240) <Quantification of Halogen Content by Elemental Analysis>

(241) The polyamide composition was incinerated in a flask that had been flushed with high-purity oxygen, the generated gas was captured using an absorbent, and the halogen element within the capture liquid was quantified by a potentiometric titration with 1/100 N silver nitrate solution.

(242) In those cases where the composition included a plurality of halogen elements, each element was first separated by ion chromatography, and then quantified using the above potentiometric titration method.

(243) <Evaluation of Moldability and External Appearance>

(244) An “FN3000” apparatus manufactured by Nissei Plastic Industrial Co., Ltd. was used.

(245) With the cylinder temperature set to 290° C. and the mold temperature set to 100° C., molding was conducted for 100 shots using the polyamide composition under injection molding conditions including an injection time of 10 seconds and a cooling time of 10 seconds, thus obtaining molded bodies (ISO test pieces).

(246) The moldability was evaluated on the basis of the mold releasability following molding, and a case in which the proportion of molded bodies that stuck to the mold across the 100 shots was 10% or less was evaluated as A, a proportion of greater than 10% but not more than 20% was evaluated as B, a proportion of greater than 20% but not more than 50% was evaluated as C, and a proportion exceeding 50% was evaluated as D.

(247) Further, in terms of the external appearance of the obtained molded bodies, the 60° gloss of the grip portion of each prepared molded body was measured in accordance with JIS-K7150 using a gloss meter (IG320, manufactured by Horiba, Ltd.). A surface gloss of 60 or higher was evaluated as A, a surface gloss of at least 55 but not more than 59 was evaluated as B, a surface gloss of at least 50 but not more than 54 was evaluated as C, and a surface gloss lower than 50 was evaluated as D.

(248) <Measurement of Tensile Strength>

(249) Using the ISO test pieces from shots 20 to 25 obtained in the above evaluation of the moldability and external appearance, the flexural modulus was measured in accordance with ISO 527. The average value of n=6 was recorded as the measured value.

(250) <Measurement of Flexural Modulus>

(251) Using the ISO test pieces from shots 20 to 25 obtained in the above evaluation of the moldability and external appearance, the flexural modulus was measured in accordance with ISO 178. The average value of n=6 was recorded as the measured value.

(252) <Measurement of Charpy Impact Strength>

(253) Using the ISO test pieces from shots 20 to 25 obtained in the above evaluation of the moldability and external appearance, the Charpy impact strength was measured in accordance with ISO 179. The average value of n=6 was recorded as the measured value.

(254) <Evaluation of Flame Retardancy>

(255) Measurements were performed using the method UL94 (a standard prescribed by Underwriters Laboratories Inc., USA). The test piece (length: 127 mm, width: 12.7 mm, thickness: 1.6 mm) was prepared by fitting a mold for the UL test piece (mold temperature=100° C.) to an injection molding machine (PS40E manufactured by Nissei Plastic Industrial Co., Ltd.) and molding the polyamide composition at a cylinder temperature of 290° C. The injection pressure was set to a value of the complete filling pressure when molding the UL test piece+2%. The flame retardancy classifications used were those prescribed in the UL94 standard (vertical flame test).

Example 3-1

(256) Using a TEM 35 mm twin-screw extruder manufactured by Toshiba Machine Co., Ltd. (temperature setting: 280° C., screw rotational rate: 300 rpm), a mixture obtained by blending the polyamides (3A-1) and (3A-2), the flame retardant (3C1), the flame retardant auxiliary (3C2) and the polymer (3D) containing an α,β-unsaturated dicarboxylic acid anhydride as a structural unit was supplied to a top feed port provided in the most upstream portion of the extruder, the filler (3E) was supplied from a side feed port on the downstream side of the extruder (at a point where the resins supplied from the top feed port had reached a satisfactorily melted state), and the melt kneaded product extruded from the die head was cooled in a strand-like state and then pelletized to obtain pellets of the polyamide composition. The blend amounts were 18.8% by mass for the polyamide (3A-1), 10.2% by mass for the polyamide (3B-1), 10.5% by mass for the flame retardant (3C1), 2.0% by mass for the flame retardant auxiliary (3C2), 3.5% by mass for the polymer (3D) containing an α,β-unsaturated dicarboxylic acid anhydride as a structural unit, and 55% by mass for the filler (3E).

(257) Further, using the thus obtained polyamide composition pellets, molded articles were produced using the methods described above, and evaluations of the moldability during molding, the external appearance, the tensile strength, the flexural modulus, the Charpy impact strength and the flame retardancy were performed. The evaluation results are shown below in Table 3-1.

Example 3-2

(258) With the exception of altering the blend amounts to include 17.3% by mass of the polyamide (3A-1) and 11.7% by mass of the polyamide (3B-1), production and evaluation were performed in the same manner as Example 3-1.

Example 3-3

(259) With the exception of altering the blend amounts to include 17.6% by mass of the polyamide (3A-1), 11.9% by mass of the polyamide (3B-1) and 10.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

Example 3-4

(260) With the exception of altering the blend amounts to include 18.2% by mass of the polyamide (3A-1), 12.3% by mass of the polyamide (3B-1) and 9.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

Example 3-5

(261) With the exception of altering the blend amounts to include 16.5% by mass of the polyamide (3A-1), 11.0% by mass of the polyamide (3B-1) and 12.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

Example 3-6

(262) With the exception of altering the blend amounts to include 15.9% by mass of the polyamide (3A-1) and 13.1% by mass of the polyamide (3B-1), production and evaluation were performed in the same manner as Example 3-1.

Example 3-7

(263) With the exception of altering the blend amounts to include 17.1% by mass of the polyamide (3A-1), 7.4% by mass of the polyamide (3B-3) and 15.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

Comparative Example 3-1

(264) With the exception of altering the blend amounts to include 29.5% by mass of the polyamide (3A-1), 0% by mass of the polyamide (3B-1) and 10.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

Comparative Example 3-2

(265) With the exception of altering the blend amounts to include 0% by mass of the polyamide (3A-1), 29.5% by mass of the polyamide (3B-1) and 10.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

Comparative Example 3-3

(266) With the exception of altering the blend amounts to include 0% by mass of the polyamide (3A-1), 24.5% by mass of the polyamide (3B-5) and 15.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

Comparative Example 3-4

(267) With the exception of altering the blend amounts to include 23.4% by mass of the polyamide (3A-1), 10.1% by mass of the polyamide (3B-2) and 6.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

Comparative Example 3-5

(268) With the exception of altering the blend amounts to include 0% by mass of the polyamide (3A-1), 20.6% by mass of the polyamide (3A-2), 8.9% by mass of the polyamide (3B-3) and 10.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

Comparative Example 3-6

(269) With the exception of altering the blend amounts to include 5.9% by mass of the polyamide (3A-1), 39.2% by mass of the polyamide (3B-6), 3.0% by mass of the flame retardant (3C1), 0% by mass of the polymer (3D) containing an α,β-unsaturated dicarboxylic acid anhydride as a structural unit, and 50 by mass of the filler (3E), production and evaluation were performed in the same manner as Example 3-1.

Comparative Example 3-7

(270) With the exception of altering the blend amounts to include 21.9% by mass of the polyamide (3A-1), 14.6% by mass of the polyamide (3B-4) and 3.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

Comparative Example 3-8

(271) With the exception of altering the blend amounts to include 5.7% by mass of the polyamide (3A-1), 3.8% by mass of the polyamide (3B-4) and 30.0% by mass of the flame retardant (3C1), production and evaluation were performed in the same manner as Example 3-1.

(272) TABLE-US-00003 TABLE 3-1 Exam- Exam- Exam- Exam- Exam- Exam- Exam- ple ple ple ple ple ple ple Type Units 3-1 3-2 3-3 3-4 3-5 3-6 3-7 Aliphatic 3A-1 % by mass 18.8 17.3 17.6 18.2 16.5 15.9 17.1 polyamide (3A) 3A-2 % by mass Semi-aromatic 3B-1 % by mass 10.2 11.7 12.3 11.0 13.1 polyamide (3B) 3B-2 % by mass 3B-3 % by mass 7.4 3B-4 % by mass 11.9 3B-5 % by mass 3B-6 % by mass Flame retardant Br—PS % by mass 10.5 10.5 10.0 9.0 12.0 10.5 15.0 (3C1) Flame retardant Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 2.0 2.0 auxiliary (3C2) Polymer (3D) Maleic % by mass 3.5 3.5 3.5 3.5 3.5 3.5 3.5 containing an anhydride- α,β-unsaturated modified dicarboxylic acid polyphenylene anhydride as ether a structural unit Filler (3E) GF % by mass 55.0 55.0 55.0 55.0 55.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Physical halogen % by mass 7.0 7.0 6.7 6.0 8.0 7.0 10.1 properties content of polyamide tan δ peak ° C. 111 115 115 112 117 115 109 composition temperature Mw g/mol 29,750 29,000 31,000 29,000 29,000 28,250 31,400 Mw(3A) − Mw(3B) g/mol 15,000 15,000 10,000 15,000 15,000 15,000 8,000 Mn 500 to 2000 % 1.6 1.7 1.7 1.7 1.7 1.8 1.4 Mw/Mn 2.1 2.1 2.1 2.1 2.1 2.1 2.4 [NH.sub.2]/([NH.sub.2] + 0.33 0.32 0.32 0.32 0.32 0.32 0.45 [COOH]) Characteristics moldability A A A A A A A of polyamide external A A A A A A C composition appearance flame V-0 V-0 V-0 V-0 V-0 V-0 V-0 retardancy UL94 (1.6 mm) tensile strength MPa 240 231 233 236 227 225 225 flexural modulus GPa 20.0 20.4 20.5 20.0 21.3 21.0 21.6 Charpy impact 19.5 20.1 20.5 20.0 20.7 21.0 19.0 strength Compar- Compar- Compar- Compar- Compar- Compar- Compar- Compar ative ative ative ative ative ative ative ative Example Example Example Example Example Example Example Example Type Units 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 Aliphatic 3A-1 % by mass 29.5 23.4 5.9 21.9 5.7 polyamide (3A) 3A-2 % by mass 20.6 Semi-aromatic 3B-1 % by mass 29.5 polyamide (3B) 3B-2 % by mass 10.1 3B-3 % by mass 8.9 3B-4 % by mass 14.6 3.8 3B-5 % by mass 24.5 3B-6 % by mass 39.2 Flame retardant Br—PS % by mass 10.0 10.0 15.0 6.0 10.0 3.0 3.0 30.0 (3C1) Flame retardant Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 auxiliary (3C2) Polymer (3D) Maleic % by mass 3.5 3.5 3.5 3.5 3.5 0.0 3.5 3.5 containing an anhydride- α,β-unsaturated modified dicarboxylic polyphenylene acid anhydride as ether a structural unit Filler (3E) GF % by mass 55.0 55.0 55.0 55.0 55.0 50.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Physical halogen % by mass 6.7 6.7 10.1 4.0 6.7 2.0 2.0 20.1 properties content of polyamide tan δ peak ° C. 60 135 100 106 96 120 110 107 composition temperature Mw g/mol 35,000 20,000 32,000 40,800 28,860 41,000 31,000 31,000 Mw(3A) − Mw(3B) g/mol — — — −9,000 −1,000 0 10,000 10,000 Mn 500 to 2000 % 1.2 2.0 1.0 1.2 1.6 1.5 1.7 1.7 Mw/Mn 2.0 2.0 2.0 2.4 2.2 2.2 2.1 2.1 [NH.sub.2]/([NH.sub.2] + 0.38 0.24 0.22 0.45 0.45 0.45 0.32 0.32 [COOH]) Characteristics moldability A D B A A B A D of polyamide external D A A C A A A D composition appearance flame V-2 V-0 V-0 V-1 V-1 V-1 V-2 V-0 retardancy UL94 (1.6 mm) tensile strength MPa 210 200 219 225 210 186 231 180 flexural modulus GPa 19.0 22.0 21.6 19.0 18.4 18.9 19.0 22.0 Charpy impact 17.0 15.0 18.1 19.0 18.5 6.8 21.0 15.0 strength

(273) As is evident from the results shown in Table 3-1, in each of the polyamide compositions of the present invention, the dicarboxylic acid units of the semi-aromatic polyamide (3B) included at least 50 mol % of isophthalic acid, and therefore the tan δ peak temperature of the polyamide composition increased. As a result, the molded articles of the polyamide compositions of Examples 3-1 to 3-7 had excellent properties including superior tensile strength, flexural modulus and Charpy impact strength. Further, by ensuring that the halogen content was greater than 2% by mass but not more than 20% by mass, excellent flame retardancy was achieved in addition to the above properties. Furthermore, because the weight average molecular weight Mw of the polyamide composition was within the range 10,000≤Mw≤40,000, excellent moldability and external appearance were obtained in addition to the above properties.

(274) In contrast, Comparative Example 3-1 did not contain the semi-aromatic polyamide (3B), and in Comparative Example 3-3, the dicarboxylic acid units of the semi-aromatic polyamide (3B) included less than 50 mol % of isophthalic acid, and therefore the molded articles of the polyamide compositions exhibited unsatisfactory flame retardancy, tensile strength, flexural modulus, Charpy impact strength, moldability and external appearance.

(275) In Comparative Example 3-2, although the dicarboxylic acid units of the semi-aromatic polyamide (3B) included at least 50 mol % of isophthalic acid, because the aliphatic polyamide (3A) was not included, the balance between the external appearance and the flame retardancy, the tensile strength, the flexural modulus and the Charpy impact strength was poor and unsatisfactory. In Comparative Example 3-4, although the dicarboxylic acid units of the semi-aromatic polyamide (3B) included at least 50 mol % of isophthalic acid, because the weight average molecular weight Mw was large, the balance between the external appearance and the flame retardancy, the tensile strength, the flexural modulus and the Charpy impact strength was poor and unsatisfactory. In Comparative Example 3-5, although the dicarboxylic acid units of the semi-aromatic polyamide (3B) included at least 50 mol % of isophthalic acid, because the tan δ peak temperature was lower than 100° C., the balance between the physical properties of the polyamide composition molded article was unsatisfactory.

(276) In the Comparative Example 3-6, the dicarboxylic acid units of the semi-aromatic polyamide (3B) did not include isophthalic acid, the weight average molecular weight Mw was large, the halogen content was 2% by mass or less, and the polymer (3D) containing an α,β-unsaturated dicarboxylic acid anhydride as a structural unit was not included, and the balance between the physical properties of the polyamide composition molded articles was unsatisfactory.

(277) In Comparative Example 3-7, although the dicarboxylic acid units of the semi-aromatic polyamide (3B) included at least 50 mol % of isophthalic acid, the halogen content was 2% by mass or less, whereas in Comparative Example 3-8, although the dicarboxylic acid units of the semi-aromatic polyamide (3B) included at least 50 mol % of isophthalic acid, the halogen content was greater than 20% by mass, and in both cases the balance between the physical properties of the polyamide composition molded articles was unsatisfactory.

Examples 4-1 to 4-3, Comparative Examples 4-1 to 4-3

(278) In the following examples, 1 kg/cm.sup.2 means 0.098 MPa.

(279) First, the crystalline polyamide (4A), the amorphous semi-aromatic polyamides (4B), the polyphenylene ethers (4C), and the inorganic filler used in the examples and comparative examples are described below.

(280) (4A) Crystalline Polyamide

(281) 4A-1: a polyamide 66, Mw=35,000, Mw/Mn=2 (the same polyamide as 1A-1 above was used)

(282) (4B) Amorphous Semi-Aromatic Polyamides

(283) 4B-1: a polyamide 6I, Mw=20,000, Mw/Mn=2 (the same polyamide as 1B-2 above was used)

(284) 4B-2: a polyamide 6I T-40 (manufactured by Lanxess AG, Mw=44,000, Mw/Mn=2.8)

(285) 4B-3: a polyamide 6I/6T Grivory 21 (manufactured by Ems Group, Mw=27,000, Mw/Mn=2.2, proportion of isophthalic acid in dicarboxylic acid units: 70 mol %)

(286) (4C) Polyphenylene Ether

(287) 4C-1: a polyphenylene ether (reduced viscosity (measured in a 0.5 g/dl chloroform solution at 30° C.): 0.52)

(288) 4C-2: a maleic anhydride-modified polyphenylene ether (the same compound as 2E above was used)

(289) Inorganic Filler

(290) (1) Glass fiber, product name: ECS03T275H, manufactured by Nippon Electric Glass Co., Ltd., average fiber diameter: 10 μm (circular), cut length: 3 mm

(291) In the examples, the average fiber diameter of the glass fiber was measured in the manner described below.

(292) First, the polyamide composition was placed in an electric furnace, and the organic matter contained in the polyamide composition was incinerated. From the residue obtained following this incineration treatment, at least 100 glass fibers were selected randomly and observed using a scanning electron microscope (SEM), and the fiber diameter of each of these glass fibers was measured to determine the number-average fiber diameter.

(293) The crystalline polyamide (4A) and the amorphous semi-aromatic polyamides (4B) used in these examples and comparative examples were produced by appropriate use of (a) and (b) below.

(294) ((a) Dicarboxylic acids)

(295) (1) Adipic acid (ADA) (manufactured by Wako Pure Chemical Industries, Ltd.)

(296) (2) Isophthalic acid (IPA) (manufactured by Wako Pure Chemical Industries, Ltd.)

(297) ((b) Diamine)

(298) (1) 1,6-diaminohexane (hexamethylenediamine) (C6DA) (manufactured by Tokyo Chemical Industry Co., Ltd.)

(299) [Production of Polyamides]

Examples 4-1 to 4-3, and Comparative Examples 4-1 to 4-3

(300) Using the above crystalline polyamide (4A), amorphous semi-aromatic polyamides (4B) and polyphenylene ethers (4C) in the formulations and proportions shown below in Table 4-1, polyamide compositions were produced in the manner described below.

(301) The polyamides obtained above were dried under a stream of nitrogen to reduce the moisture content to about 0.2% by mass before being used as raw materials for the polyamide compositions.

(302) A twin-screw extruder “ZSK-26MC” manufactured by Coperion GmbH (Germany) was used as the polyamide composition production apparatus.

(303) The twin-screw extruder had an upstream supply port on the first barrel from the upstream side of the extruder, had a downstream first supply port on the sixth barrel, and had a downstream second supply port on the ninth barrel. Further, in the twin-screw extruder, L/D was 48, and the number of barrels was 12.

(304) In the twin-screw extruder, the temperature from the upstream supply port to the die was set to the melting point Tm2 of the polyamide (4A-1)+20° C., the screw rotational rate was set to 250 rpm, and the discharge rate was set to 25 kg/h.

(305) The crystalline polyamide (4A), the amorphous semi-aromatic polyamide (4B) and the polyphenylene ether (4C) were dry-blended using the formulations and proportions shown below in Table 4-1 and then supplied to the upstream supply port of the twin-screw extruder, the glass fiber (GF) was supplied as an inorganic filler from the downstream first supply port of the twin-screw extruder, and the melt-kneaded product extruded from the die head was cooled in a strand-like form and then pelletized to obtain pellets of a polyamide composition (containing glass fiber).

(306) The obtained pellets of the polyamide composition were dried under a stream of nitrogen to reduce the moisture content within the polyamide composition to not more than 500 ppm.

(307) [Measurement Methods for Polyamide Compositions]

(308) Using the polyamide compositions for which the moisture content had been adjusted, each of the following evaluations was performed. The evaluation results are shown below in Table 4-1.

(309) (1) Melting Peak Temperature Tm2 (Melting Point), Crystallization Peak Temperature Tc, and Crystallization Enthalpy

(310) These values were measured using a Diamond-DSC device manufactured by PerkinElmer, Inc., in accordance with JIS-K7121. Specifically, measurements were performed in the following manner.

(311) First, under a nitrogen atmosphere, a sample of about 10 mg was heated from room temperature to a temperature of 300 to 350° C., depending on the melting point of the sample, at a rate of temperature increase of 20° C./min. The highest peak temperature of the endothermic peak (melting peak) that appeared during this process was recorded as Tm1 (° C.). Next, the temperature was maintained at the maximum heating temperature for two minutes. At this maximum temperature, the polyamides existed in a melted state. Subsequently, the sample was cooled to 30° C. at a rate of temperature reduction of 20° C./min. The exothermic peak that appeared during this process was deemed the crystallization peak, the crystallization peak temperature was recorded as Tc, and the surface area of the crystallization peak was deemed the crystallization enthalpy ΔH (J/g). Subsequently, the sample was held at 30° C. for two minutes, and was then heated from 30° C. to a temperature of 280 to 300° C., depending on the melting point of the sample, at a rate of temperature increase of 20° C./min. The highest peak temperature of the endothermic peak (melting peak) that appeared during this process was deemed the melting point Tm2 (° C.).

(312) (2) Tan δ Peak Temperature

(313) Using a viscoelasticity measuring and analysis device (DVE-V4, manufactured by Rheology Co., Ltd.), a temperature variance spectrum of the dynamic viscoelasticity of a test piece prepared by cutting the parallel portion of a Type L test piece prescribed in ASTM D1822 into a short strip was measured under the conditions described below. The dimensions of the test piece were 3.1 mm (width)×2.9 mm (thickness)×15 mm (length: distance between clamps).

(314) Measurement mode: tensile, waveform: sine wave, frequency: 3.5 Hz, temperature range: 0° C. to 180° C., temperature increase steps: 2° C./min, static load: 400 g, displacement amplitude: 0.75 μm. The ratio E2/E1 between the storage modulus E1 and the loss modulus E2 was recorded as tan δ, and the highest temperature was deemed the tan δ peak temperature.

(315) (3) Mw (Weight Average Molecular Weight), Mn (Number Average Molecular Weight), Molecular Weight Distribution Mw/Mn, Mw(4A)−Mw(4B)

(316) The Mw (weight average molecular weight), Mn (number average molecular weight), Mw(4A) and Mw(4B) were measured by GPC (gel permeation chromatography using an HLC-8020 device manufactured by Tosoh Corporation, using hexafluoroisopropanol solvent and calculated against PMMA (polymethyl methacrylate) standard samples (manufactured by Polymer Laboratories Ltd.)). Based on these values, Mw(4A)−Mn(4B) and the molecular weight distribution Mw/Mn were calculated. The amount (% by mass) of compounds having a number average molecular weight Mn of at least 500 but not more than 2,000 was calculated from the elution curve (vertical axis: signal strength obtained from detector, horizontal axis: elution time) of each sample obtained using GPC, based on the surface area of the region bounded by the baseline and the elution curve for number average molecular weights from at least 500 to less than 2,000, and the surface area of the entire region bounded by the baseline and the elution curve.

(317) (4) Amount of Amino Ends ([NH.sub.2])

(318) The amount of amino ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(319) First, 3.0 g of the polyamide was dissolved in 100 mL of a 90% by mass aqueous solution of phenol, and using the thus obtained solution, a titration was performed with 0.025 N hydrochloric acid to determine the amount of amino ends (μeq/g). The end point was determined using the reading from a pH meter.

(320) (5) Amount of Carboxyl Ends ([COOH])

(321) The amount of carboxyl ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(322) First, 4.0 g of the polyamide was dissolved in 50 mL of benzyl alcohol, and using the thus obtained solution, a titration was performed with 0.1 N NaOH to determine the amount of carboxyl ends (μeq/g). The end point was determined by the change in color of a phenolphthalein indicator.

(323) Based on the amount of amino ends ([NH.sub.2]) and the amount of carboxyl ends ([COOH]) measured in (4) and (5) above, the value of [NH2]/([NH2]+[COOH]) was calculated.

(324) (6) Surface Gloss

(325) A flat plate molded piece was produced in the following manner.

(326) Using an injection molding machine [NEX50III-5EG, manufactured by Nissei Plastic Industrial Co., Ltd.] with the cooling time set to 25 seconds, the screw rotational rate set to 200 rpm, the mold temperature set to the tan δ peak temperature+5° C., and the cylinder temperature set to (Tm2+10°) C to (Tm2+30°) C, the injection pressure and injection speed were adjusted appropriately to achieve a fill time of 1.6+0.1 seconds, and a flat plate molded piece (6 cm×9 cm, thickness: 2 mm) was produced.

(327) The 60° gloss of the central portion of the flat plate molded piece prepared in this manner was measured in accordance with JIS-K7150 using a gloss meter (IG320, manufactured by Horiba, Ltd.).

(328) A larger measured value was adjudged to indicate more superior surface appearance.

(329) (7) MD (Mold Deposits) During Molding

(330) The molding described above in (6) was repeated for 100 consecutive shots, and following completion of the molding, the gas vent was inspected visually.

(331) The evaluation criteria for gas generation during molding were as listed below. The ability to obtain molded articles without problems was evaluated as leading to an improvement in productivity.

(332) (Evaluation Criteria)

(333) A: no deposits observed on gas vent

(334) B: some deposits observed on gas vent

(335) C: deposits observed on gas vent, with a blockage beginning to occur

(336) D: deposits observed on gas vent, with vent blocked

(337) (8) Tensile Strength

(338) Using an injection molding machine [PS-40E, manufactured by Nissei Plastic Industrial Co., Ltd.], molded pieces of the multipurpose test piece type A were molded in accordance with ISO 3167. The specific molding conditions included an injection+holding time of 25 seconds, a cooling time of 15 seconds, a mold temperature of 80° C., and a melted resin temperature set to the high temperature-side melting peak temperature (Tm2) for the polyamides+20° C.

(339) Using the thus obtained molded piece of multipurpose test piece type A, a tensile test was performed in accordance with ISO 527 under conditions including temperature conditions of 80° C. and a tension rate of 50 mm/min, thereby measuring the tensile yield stress, which was recorded as the tensile strength.

(340) (9) Weld Strength

(341) A test piece was obtained by conducting molding using an injection molding machine (PS40E manufactured by Nissei Plastic Industrial Co., Ltd.) fitted with a mold having a shape with dimensions of length: 127 mm, width: 12.7 mm and thickness: 1.6 mm, wherein the melted resin was injected from both lengthwise ends of the mold so as to form a weld in the central portion of the lengthwise direction. This molded test piece was subjected to a tensile test using the method prescribed in ASTM D638, with the exception of altering the chuck separation distance to 50 mm and the tension rate to 50 mm/min, thus determining the tensile strength.

(342) (10) Flexural Modulus (80° C.) after Water Absorption

(343) An ISO dumbbell with a thickness of 4 mm was prepared and used as a test piece. The ISO dumbbell was left to stand in a constant-temperature constant-humidity (23° C., 50% RH) environment, and once water absorption equilibrium had been reached, the flexural modulus was measured in accordance with ISO 178 under temperature conditions of 80° C.

(344) TABLE-US-00004 TABLE 4-1 Example Example Example Comparative Comparative Comparative Type Units 4-1 4-2 4-3 Example 4-1 Example 4-2 Example 4-3 Polyamide (4A) 4A-1 parts by mass 67 60 67 70 67 67 Polyamide (4B) 4B-1 parts by mass 29 26 29 30 4B-2 parts by mass 29 4B-3 parts by mass 29 Polyphenylene ether 4C-1 parts by mass 5 15 0 5 5 (4C) 4C-2 parts by mass 5 Inorganic filler GF parts by mass 150 150 150 150 150 150 Physical properties of Tm2 ° C. 257 257 257 257 257 259 polyamide composition Tc ° C. 210 210 210 210 210 217 Crystallization enthalpy J/g 21.0 21.0 21.0 21.0 20.3 20.5 tan δ peak temperature ° C. 111 111 111 111 106 109 Mw 32,000 32,000 32,000 32,000 38,000 37,000 Mw(4A) − Mw(4B) 15,000 15,000 15,000 15,000 −9,000 8,000 Mn 500 to 2000 % 1.6 1.6 1.6 1.6 1.2 1.3 Mw/Mn 2.1 2.1 2.1 2.1 2.5 2.4 [NH.sub.2]/([NH.sub.2] + [COOH]) 0.30 0.30 0.30 0.30 0.45 0.45 Surface gloss % 56 51 58 61 39 29 MD during molding B C A A C C 80° C. tensile strength MPa 167 172 175 162 145 147 Weld strength 86 88 91 92 88 84 Flexural modulus (80° C.) GPa 10.6 11.1 11.5 9.8 10.4 10.6 after water absorption

(345) As shown in Table 4-1, in Example 4-1 in which was formed a polyamide composition of the present invention containing the crystalline polyamide (4A), the amorphous semi-aromatic polyamide (4B) containing a dicarboxylic acid unit that included at least 75 mol % of isophthalic acid and a diamine unit that included at least 50 mol % of a diamine of 4 to 10 carbon atoms, and the polyphenylene ether (4C), wherein the tan δ peak temperature of the polyamide composition was at least 90° C., and the weight average molecular weight Mw of the polyamide composition satisfied 15,000≤Mw≤35,000, the surface appearance, the degree of MD during molding, the tensile strength and the flexural modulus after water absorption were particularly superior compared with Comparative Example 4-1 which did not contain the polyphenylene ether (4C), and Comparative Examples 4-2 and 4-3 which although containing the crystalline polyamide (4A), the amorphous semi-aromatic polyamide (4B) and the polyphenylene ether (4C), had a weight average molecular weight Mw for the polyamide composition that exceeded 35,000.

Examples 5-1 to 2-4, Comparative Examples 2-1 to 2-7

(346) <Constituent Components>

(347) [(5A) Aliphatic Polyamides]

(348) 5A-1: a polyamide 66 (the same polyamide as 1A-1 above was used)

(349) 5A-2: a polyamide 6 (SF1013A manufactured by Ube Industries, Ltd., Mw=26,000, Mw/Mn=2.0)

(350) The above polyamides were dried under a stream of nitrogen to reduce the moisture content to about 0.2% by mass before being used as raw materials for the polyamide compositions.

(351) [(5B) Semi-Aromatic Polyamides]

(352) 5B-1: a polyamide 6I (the same polyamide as 1B-2 above was used)

(353) 5B-2: a polyamide 6I/6T (G21 manufactured by Ems Group, Mw=27,000, Mw/Mn=2.2, VR=27, Mw/VR=1,000, proportion of isophthalic acid in dicarboxylic acid units: 70 mol %)

(354) 5B-3: a polyamide 6I (high molecular weight) (the same polyamide as 2B-4 above was used)

(355) 5B-4: a polyamide 66/6I (the same polyamide as 1B-1 above was used)

(356) 5B-5: a polyamide MXD6 (product name: Toyobo Nylon T-600, manufactured by Toyobo Co., Ltd., proportion of isophthalic acid in dicarboxylic acid units: 0 mol %)

(357) The above polyamides were dried under a stream of nitrogen to reduce the moisture content to about 0.2% by mass before being used as raw materials for the polyamide compositions.

(358) [(5C1) Flame Retardant]

(359) 5C1: a brominated polystyrene (product name “SAYTEX (a registered trademark) HP-7010G” manufactured by Albemarle Corporation (bromine content as determined by elemental analysis: 67% by mass))

(360) [(5C2) Flame Retardant Auxiliary]

(361) 5C2: Diantimony trioxide (product name “Antimony Trioxide” manufactured by Daiichi F. R. co., Ltd.)

(362) [(5D) White Pigment]

(363) 5D: Zinc sulfide (ZnS) (SACHTOLITH HD-S)

(364) [(5E) Ultraviolet Absorbers]

(365) 5E-1: a benzotriazole-based ultraviolet absorber (UVA-1) (ADEKA STAB LA-31)

(366) 5E-2: a triazine-based ultraviolet absorber (UVA-2) (Tinuvin 1600)

(367) [(5F) Polymer Containing an α,β-Unsaturated Dicarboxylic Acid Anhydride Unit]

(368) 5F: a maleic anhydride-modified polyphenylene ether (the same compound as 2E above was used)

(369) [(5G) Filler]

(370) 5G: Glass fiber (GF) (product name “ECS03T275H” manufactured by Nippon Electric Glass Co., Ltd., average fiber diameter: 10 μmφ, cut length: 3 mm)

(371) <Physical Properties and Evaluations>

(372) First, the polyamide composition pellets obtained in the examples and comparative examples were dried under a stream of nitrogen to reduce the moisture content within the polyamide composition to not more than 500 ppm. Each of the polyamide compositions for which the moisture content had been adjusted was then subjected to various physical property measurements and various evaluations using the methods described below.

(373) [Physical Property 1] Tan δ Peak Temperature

(374) Using a PS40E injection molding machine manufactured by Nissei Plastic Industrial Co., Ltd., with the cylinder temperature set to 290° C. and the mold temperature set to 100° C., a molded article was molded in accordance with JIS-K7139 under injection molding conditions including an injection time of 10 seconds and a cooling time of 10 seconds. This molded article was measured under the following conditions using a dynamic viscoelasticity evaluation device (EPLEXOR 500N, manufactured by Gabo GmbH).

(375) (Measurement Conditions)

(376) Measurement mode: tensile

(377) Measurement frequency: 8.00 Hz

(378) Rate of temperature increase: 3° C./min

(379) Temperature range: −100 to 250° C.

(380) The ratio (E2/E1) between the storage modulus E1 and the loss modulus E2 was recorded as tan δ, and the highest temperature was deemed the tan δ peak temperature.

(381) [Physical Property 2] Molecular Weight and End Structures of Polyamide Compositions (1) Number Average Molecular Weight and Weight Average Molecular Weight of Polyamide Compositions

(382) The number average molecular weight (Mn) and weight average molecular weight (Mw) of each polyamide composition obtained in the examples and comparative examples were measured by GPC (gel permeation chromatography) under the conditions described below. Based on these values, Mw(5A)−Mn(5B) and the molecular weight distribution Mw/Mn were calculated. Further, the amount (% by mass) of polyamides having a number average molecular weight Mn of at least 500 but not more than 2,000 among all of the polyamides in the polyamide composition was calculated from the elution curve (vertical axis: signal strength obtained from detector, horizontal axis: elution time) of each sample obtained using GPC, based on the surface area of the region bounded by the baseline and the elution curve for number average molecular weights from at least 500 to less than 2,000, and the surface area of the region bounded by the baseline and the elution curve for all the number average molecular weights.

(383) (Measurement Conditions)

(384) Measurement apparatus: HLC-8020 manufactured by Tosoh Corporation

(385) Solvent: hexafluoroisopropanol solvent

(386) Standard samples: PMMA (polymethyl methacrylate) standard samples (manufactured by Polymer Laboratories Ltd.)

(387) GPC columns: TSKgel GMHHR-M and G1000HHR

(388) (2) Amount of Amino Ends ([NH.sub.2])

(389) In the polyamide compositions obtained in the examples and comparative examples, the amount of amino ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(390) First, 3.0 g of each polyamide composition was dissolved in 100 mL of a 90% by mass aqueous solution of phenol, and using the thus obtained solution, a titration was performed with 0.025 N hydrochloric acid to determine the amount of amino ends (μeq/g). The end point was determined using the reading from a pH meter.

(391) (3) Amount of Carboxyl Ends ([COOH])

(392) In the polyamide compositions obtained in the examples and comparative examples, the amount of carboxyl ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(393) First, 4.0 g of the polyamide composition was dissolved in 50 mL of benzyl alcohol, and using the thus obtained solution, a titration was performed with 0.1 N NaOH to determine the amount of carboxyl ends (μeq/g). The end point was determined by the change in color of a phenolphthalein indicator.

(394) (4) Ratio of Amount of Amino Ends to Total Amount of Active Ends ([NH2]/[(NH2]+[COOH])

(395) Based on the amount of amino ends ([NH2]) and the amount of carboxyl ends ([COOH]) obtained in (2) and (3), the total amount of active ends ([NH.sub.2]+[COOH]) and the ratio of the amount of amino ends relative to the total amount of active ends ([NH.sub.2]/[(NH.sub.2]+[COOH])) were calculated.

(396) [Physical Property 3] Formic Acid Solution Viscosity VR Each of the semi-aromatic polyamides 5B-1 to 5B-5 was dissolved in formic acid, and measurement was performed in accordance with ASTM-D789.

(397) [Evaluation 1] Moldability and External Appearance

(398) (1) Production of Molded Articles

(399) An “FN3000” apparatus manufactured by Nissei Plastic Industrial Co., Ltd. was used. With the cylinder temperature set to 290° C. and the mold temperature set to 100° C., molding was conducted for 100 shots using each polyamide composition under injection molding conditions including an injection time of 10 seconds and a cooling time of 10 seconds, thus obtaining molded articles (ISO test pieces).

(400) (2) Evaluation of Moldability

(401) The moldability was evaluated against the following evaluation criteria, on the basis of the percentage of the 100 shots in which the molded article stuck to the mold during mold release following molding.

(402) (Evaluation Criteria)

(403) A: 10% or less

(404) B: greater than 10% but not more than 20%

(405) C: greater than 20% but not more than 50%

(406) D: greater than 50%

(407) (3) Evaluation of External Appearance

(408) In terms of the external appearance of the obtained molded articles, the 60.sup.0 gloss of the grip portion of each molded article was measured in accordance with JIS-K7150 using a gloss meter (IG320, manufactured by Horiba, Ltd.). Based on the measured surface gloss, the external appearance was evaluated against the following criteria.

(409) (Evaluation Criteria)

(410) A: at least 60

(411) B: at least 55 but less than 60

(412) C: at least 50 but less than 55

(413) D: less than 50

(414) [Evaluation 2] Weathering Discoloration Resistance

(415) Using a WEL-SUN-DCH sunshine carbon-arc lamp weather resistance testing apparatus manufactured by Suga Test Instruments Co., Ltd., a molded article obtained in [Evaluation 1] was exposed for 100 hours under conditions including a black panel temperature of 65° C., a humidity of 50% RH, and no water spray. The evaluation method used following the weather resistance test involved measuring the color tone of the molded article before and after exposure, and determining the color difference using a color difference meter ND-300A manufactured by Nippon Denshoku Industries Co., Ltd. A smaller color difference (ΔE) was evaluated as indicating more favorable weather resistance.

(416) [Evaluation 3] Flame Retardancy

(417) Measurements were performed using the method UL94 (a standard prescribed by Underwriters Laboratories Inc., USA). The test piece (length: 127 mm, width: 12.7 mm, thickness: 1.6 mm) was prepared by fitting a mold for the UL test piece (mold temperature=100° C.) to an injection molding machine (PS40E manufactured by Nissei Plastic Industrial Co., Ltd.) and molding each polyamide composition at a cylinder temperature of 290° C. The injection pressure was set to a value of the complete filling pressure when molding the UL test piece+2%. The flame retardancy classifications used were those prescribed in the UL94 standard (vertical flame test).

(418) [Evaluation 4] Weld Strength

(419) A test piece was obtained by conducting molding of each polyamide composition using an injection molding machine (PS40E manufactured by Nissei Plastic Industrial Co., Ltd.) fitted with a mold having a shape with dimensions of length: 127 mm, width: 12.7 mm and thickness: 1.6 mm, wherein the melted resin was injected from both lengthwise ends of the mold so as to form a weld in the central portion of the lengthwise direction. This molded test piece was subjected to a tensile test using the method prescribed in ASTM D638, with the exception of altering the chuck separation distance to 50 mm and the tension rate to 50 mm/min, thus determining the tensile strength. Further, the test piece was left to stand in a constant-temperature constant-humidity (23° C., 50% RH) environment, and once water absorption equilibrium had been reached, the tensile strength was again measured using the method prescribed in ASTM D638. The tensile strength retention ratio after water absorption was determined using the following formula (i).
Tensile retention ratio after water absorption (%)=tensile strength after water absorption/tensile strength before water absorption×100  (i)
[Evaluation 5] Rockwell Hardness

(420) An “FN3000” apparatus manufactured by Nissei Plastic Industrial Co., Ltd. was used. With the cylinder temperature set to 290° C. and the mold temperature set to 100° C., molding was conducted using each polyamide resin composition under injection molding conditions including an injection time of 10 seconds and a cooling time of 10 seconds, thus obtaining a molded article (ISO test piece). The Rockwell hardness (M scale) was measured using a hardness meter (ARK-F3000 manufactured by Akashi Seisakusho, Ltd.). Further, the test piece was left to stand in a constant-temperature constant-humidity (23° C., 50% RH) environment, and once water absorption equilibrium had been reached, the Rockwell hardness was again measured. The Rockwell hardness retention ratio after water absorption was determined using the following formula (ii).
Rockwell hardness retention ratio after water absorption (%)=Rockwell hardness after water absorption/Rockwell hardness before water absorption×100  (ii)

[Example 5-1] Production of Polyamide Composition 5-1

(421) Using a TEM 35 mm twin-screw extruder manufactured by Toshiba Machine Co., Ltd. (temperature setting: 280° C., screw rotational rate: 300 rpm), a mixture obtained by blending: (5A) the aliphatic polyamide 5A-1, (5B) the semi-aromatic polyamide 5B-1, (5C1) the flame retardant, (5C2) the flame retardant auxiliary, (5D) the white pigment, (5E) the ultraviolet absorber 5E-1, and (5F) the polymer containing an α,β-unsaturated dicarboxylic acid anhydride unit was supplied to a top feed port provided in the most upstream portion of the extruder. Further, the filler (5G) was supplied from a side feed port on the downstream side of the extruder (at a point where the resins supplied from the top feed port had reached a satisfactorily melted state). The melt kneaded product extruded from the die head was cooled in a strand-like state and then pelletized to obtain pellets of a polyamide composition 5-1. The blend amounts were 18.8% by mass for (5A) the aliphatic polyamide 5A-1, 10.2% by mass for (5B) the semi-aromatic polyamide 5B-1, 10.0% by mass for the flame retardant (5C1), 2.0% by mass for the flame retardant auxiliary (5C2), 2.0% by mass for the white pigment (5D), 1.0% by mass for (5E) the ultraviolet absorber 5E-1, 1.0% by mass for (5F) the polymer containing an α,β-unsaturated dicarboxylic acid anhydride unit, and 55% by mass for the filler (5G).

(422) Further, using the pellets of the thus obtained polyamide composition 5-1, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-2] Production of Polyamide Composition 5-2

(423) With the exception of altering the blend amounts to include 17.3% by mass of (5A) the aliphatic polyamide 5A-1 and 11.7% by mass of (5B) the semi-aromatic polyamide 5B-1, pellets of a polyamide composition 5-2 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-2, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-3] Production of Polyamide Composition 5-3

(424) With the exception of altering the blend amounts to include 17.3% by mass of (5A) the aliphatic polyamide 5A-1, 0% by mass of (5B) the semi-aromatic polyamide 5B-1, and 11.7% by mass of (5B) the semi-aromatic polyamide 5B-3, pellets of a polyamide composition 5-3 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-3, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-4] Production of Polyamide Composition 5-4

(425) With the exception of altering the blend amounts to include 18.0% by mass of (5A) the aliphatic polyamide 5A-1, 12.0% by mass of (5B) the semi-aromatic polyamide 5B-1, and 9.0% by mass of the flame retardant (5C1), pellets of a polyamide composition 5-4 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-4, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-5] Production of Polyamide Composition 5-5

(426) With the exception of altering the blend amounts to include 15.9% by mass of (5A) the aliphatic polyamide 5A-1, 10.6% by mass of (5B) the semi-aromatic polyamide 5B-1, 12.0% by mass of the flame retardant (5C1) and 1.5% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-5 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-5, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-6] Production of Polyamide Composition 5-6

(427) With the exception of altering the blend amounts to include 15.9% by mass of (5A) the aliphatic polyamide 5A-1 and 13.1% by mass of (5B) the semi-aromatic polyamide 5B-1, pellets of a polyamide composition 5-6 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-6, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-7] Production of Polyamide Composition 5-7

(428) With the exception of altering the blend amounts to include 18.0% by mass of (5A) the aliphatic polyamide 5A-1, 12.0% by mass of (5B) the semi-aromatic polyamide 5B-1, and 1.0% by mass of the white pigment (5D), pellets of a polyamide composition 5-7 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-7, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-8] Production of Polyamide Composition 5-8

(429) With the exception of altering the blend amounts to include 16.8% by mass of (5A) the aliphatic polyamide 5A-1, 11.2% by mass of (5B) the semi-aromatic polyamide 5B-1, and 3.0% by mass of the white pigment (5D), pellets of a polyamide composition 5-8 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-8, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-9] Production of Polyamide Composition 5-9

(430) With the exception of altering the blend amounts to include 17.6% by mass of (5A) the aliphatic polyamide 5A-1, 11.9% by mass of (5B) the semi-aromatic polyamide 5B-1, and 0.5% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-9 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-9, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown in Table 5-1.

[Example 5-10] Production of Polyamide Composition 5-10

(431) With the exception of altering the blend amounts to include 16.2% by mass of (5A) the aliphatic polyamide 5A-1, 10.8% by mass of (5B) the semi-aromatic polyamide 5B-1, and 3.0% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-10 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-10, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-11] Production of Polyamide Composition 5-11

(432) With the exception of altering the blend amounts to include 38.9% by mass of (5A) the aliphatic polyamide 5A-1, 25.6% by mass of (5B) the semi-aromatic polyamide 5B-1, 22.2% by mass of the flame retardant (5C1), 4.4% by mass of the flame retardant auxiliary (5C2), 4.4% by mass of the white pigment (5D), 2.2% by mass of (5E) the ultraviolet absorber 5E-1, 2.2% by mass of the polymer (5F) containing an α,β-unsaturated dicarboxylic acid anhydride unit, and 0% by mass of the filler (5G), pellets of a polyamide composition 5-11 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-11, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-12] Production of Polyamide Composition 5-12

(433) With the exception of altering the blend amounts to include 17.3% by mass of (5A) the aliphatic polyamide 5A-1, 11.7% by mass of (5B) the semi-aromatic polyamide 5B-1, 0% by mass of (5E) the ultraviolet absorber 5E-1, and 1.0% by mass of (5E) the ultraviolet absorber 5E-2, pellets of a polyamide composition 5-12 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-12, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-1.

[Example 5-13] Production of Polyamide Composition 5-13

(434) With the exception of altering the blend amounts to include 18.5% by mass of (5A) the aliphatic polyamide 5A-1, 0% by mass of (5B) the semi-aromatic polyamide 5B-1, 8.0% by mass of (5B) the semi-aromatic polyamide 5B-2, 12.0% by mass of the flame retardant (5C1), and 1.5% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-13 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-13, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-3.

[Example 5-14] Production of Polyamide Composition 5-14

(435) With the exception of altering the blend amounts to include 4.7% by mass of (5A) the aliphatic polyamide 5A-1, 0% by mass of (5B) the semi-aromatic polyamide 5B-1, 31.9% by mass of (5B) the semi-aromatic polyamide 5B-5, 3.0% by mass of the flame retardant (5C1), and 0.4% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-14 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-14, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-3.

[Example 5-15] Production of Polyamide Composition 5-15

(436) With the exception of altering the blend amounts to include 0% by mass of (5A) the aliphatic polyamide 5A-1, 18.5% by mass of (5A) the aliphatic polyamide 5A-2, 0% by mass of (5B) the semi-aromatic polyamide 5B-1, 8.0% by mass of (5B) the semi-aromatic polyamide 5B-2, 12.0% by mass of the flame retardant (5C1), and 1.5% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-15 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-15, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-3.

[Comparative Example 5-1] Production of Polyamide Composition 5-16

(437) With the exception of altering the blend amounts to include 29.0% by mass of (5A) the aliphatic polyamide 5A-1 and 0% by mass of (5B) the semi-aromatic polyamide 5B-1, pellets of a polyamide composition 5-16 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-16, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-2.

[Comparative Example 5-2] Production of Polyamide Composition 5-17

(438) With the exception of altering the blend amounts to include 0% by mass of (5A) the aliphatic polyamide 5A-1 and 29.0% by mass of (5B) the semi-aromatic polyamide 5B-1, pellets of a polyamide composition 5-17 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-17, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-2.

[Comparative Example 5-3] Production of Polyamide Composition 5-18

(439) With the exception of altering the blend amounts to include 0% by mass of (5A) the aliphatic polyamide 5A-1, 0% by mass of (5B) the semi-aromatic polyamide 5B-1, and 29.0% by mass of (5B) the semi-aromatic polyamide 5B-4, pellets of a polyamide composition 5-18 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-18, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-2.

[Comparative Example 5-4] Production of Polyamide Composition 5-19

(440) With the exception of altering the blend amounts to include 18.5% by mass of (5A) the aliphatic polyamide 5A-1, 12.4% by mass of (5B) the semi-aromatic polyamide 5B-1, and 0.1% by mass of the white pigment (5D), pellets of a polyamide composition 5-19 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-19, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-2.

[Comparative Example 5-5] Production of Polyamide Composition 5-20

(441) With the exception of altering the blend amounts to include 14.4% by mass of (5A) the aliphatic polyamide 5A-1, 9.6% by mass of (5B) the semi-aromatic polyamide 5B-1, and 7.0% by mass of the white pigment (5D), pellets of a polyamide composition 5-20 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-20, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-2.

[Comparative Example 5-6] Production of Polyamide Composition 5-21

(442) With the exception of altering the blend amounts to include 18.0% by mass of (5A) the aliphatic polyamide 5A-1, 12.0% by mass of (5B) the semi-aromatic polyamide 5B-1, and 0% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-21 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-21, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-2.

[Comparative Example 5-7] Production of Polyamide Composition 5-22

(443) With the exception of altering the blend amounts to include 15.0% by mass of (5A) the aliphatic polyamide 5A-1, 10.0% by mass of (5B) the semi-aromatic polyamide 5B-1, and 5.0% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-22 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-22, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-2.

[Comparative Example 5-8] Production of Polyamide Composition 5-23

(444) With the exception of altering the blend amounts to include 19.4% by mass of (5A) the aliphatic polyamide 5A-1, 0% by mass of (5B) the semi-aromatic polyamide 5B-1, 8.4% by mass of (5B) the semi-aromatic polyamide 5B-2, 12.0% by mass of the flame retardant (5C1), and 0.2% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-23 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-23, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-3.

[Comparative Example 5-9] Production of Polyamide Composition 5-24

(445) With the exception of altering the blend amounts to include 4.5% by mass of (5A) the aliphatic polyamide 5A-1, 0% by mass of (5B) the semi-aromatic polyamide 5B-1, 30.8% by mass of (5B) the semi-aromatic polyamide 5B-5, 3.0% by mass of the flame retardant (5C1), 3.5% by mass of the white pigment (5D), and 0.2% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-24 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-24, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-3.

[Comparative Example 5-10] Production of Polyamide Composition 5-25

(446) With the exception of altering the blend amounts to include 0% by mass of (5A) the aliphatic polyamide 5A-1, 19.6% by mass of (5A) the aliphatic polyamide 5A-2, 0% by mass of (5B) the semi-aromatic polyamide 5B-1, 8.4% by mass of (5B) the semi-aromatic polyamide 5B-2, 12.0% by mass of the flame retardant (5C1), and 0% by mass of (5E) the ultraviolet absorber 5E-1, pellets of a polyamide composition 5-25 were obtained using the same method as Example 5-1. Using the pellets of the thus obtained polyamide composition 5-25, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 5-3.

(447) TABLE-US-00005 TABLE 5-1 Example Example Example Example Example Example Type Units 5-1 5-2 5-3 5-4 5-5 5-6 Aliphatic 5A-1 % by mass 18.8 17.3 17.3 18.0 15.9 15.9 polyamide (5A) 5A-2 % by mass Semi-aromatic 5B-1 % by mass 10.2 11.7 12.0 10.6 13.1 polyamide (5B) 5B-2 % by mass 5B-3 % by mass 11.7 5B-4 % by mass 5B-5 % by mass Flame retardant (5C1) Br—PS % by mass 10.0 10.0 10.0 9.0 12.0 10.0 Flame retardant Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 2.0 auxiliary (5C2) White pigment (5D) ZnS % by mass 2.0 2.0 2.0 2.0 2.0 2.0 Ultraviolet 5E-1 % by mass 1.0 1.0 1.0 1.0 1.5 1.0 absorber (5E) 5E-2 % by mass Polymer (5F) containing Maleic anhydride-modified % by mass 1.0 1.0 1.0 1.0 1.0 1.0 α,β-unsaturated polyphenylene ether dicarboxylic acid anhydride unit Filler (5G) GF % by mass 55.0 55.0 55.0 55.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 100.0 PA properties in PA UVA (5E)/pigment (5D) 0.50 0.50 0.50 0.50 0.75 0.50 composition tan δ peak temperature ° C. 111 115 115 112 117 115 Mw g/mol 29,750 29,000 31,000 29,000 29,000 28,250 Mw(5A) − Mw(5B) g/mol 15,000 15,000 10,000 15,000 15,000 15,000 Mn 500 to 2000 % 1.6 1.7 1.7 1.7 1.7 1.8 Mw/Mn 2.1 2.1 2.1 2.1 2.1 2.1 [NH.sub.2]/([NH.sub.2] + [COOH]) 0.33 0.32 0.32 0.32 0.32 0.32 Properties of PA moldability A A A A A A composition external appearance A A A A A A weathering discoloration resistance 27.0 30.0 30.0 28.0 37.0 35.0 (ΔE) flame retardancy UL94 (1.6 mm) V-0 V-0 V-0 V-0 V-0 V-0 weld strength (dry) MPa 71 64 64 64 64 62 weld strength (wet) MPa 61 58 58 58 58 60 weld strength (retention ratio) % 86 91 91 91 91 97 Rockwell hardness (dry) 100 101 101 101 101 102 Rockwell hardness (wet) 99 101 101 101 101 102 Rockwell hardness (retention ratio) % 99 100 100 100 100 100 Example Example Example Example Example Example Type Units 5-7 5-8 5-9 5-10 5-11 5-12 Aliphatic 5A-1 % by mass 18.0 16.8 17.6 16.2 38.9 17.3 polyamide (5A) 5A-2 % by mass Semi-aromatic 5B-1 % by mass 12.0 11.2 11.9 10.8 25.6 11.7 polyamide (5B) 5B-2 % by mass 5B-3 % by mass 5B-4 % by mass 5B-5 % by mass Flame retardant (5C1) Br—PS % by mass 10.0 10.0 10.0 10.0 22.2 10.0 Flame retardant Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 4.4 2.0 auxiliary (5C2) White pigment (5D) ZnS % by mass 1.0 3.0 2.0 2.0 4.4 2.0 Ultraviolet 5E-1 % by mass 1.0 1.0 0.5 3.0 2.2 absorber (5E) 5E-2 % by mass 1.0 Polymer (5F) containing Maleic anhydride-modified % by mass 1.0 1.0 1.0 1.0 2.2 1.0 α,β-unsaturated polyphenylene ether dicarboxylic acid anhydride unit Filler (5G) GF % by mass 55.0 55.0 55.0 55.0 0.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 100.0 PA properties in PA UVA (5E)/pigment (5D) 1.00 0.33 0.25 1.50 0.50 0.50 composition tan δ peak temperature ° C. 115 115 115 115 106 115 Mw g/mol 29,000 29,000 29,000 29,000 29,000 29,000 Mw(5A) − Mw(5B) g/mol 15,000 15,000 15,000 15,000 15,000 15,000 Mn 500 to 2000 % 1.7 1.7 1.7 1.7 1.7 1.7 Mw/Mn 2.1 2.1 2.1 2.1 2.1 2.1 [NH.sub.2]/([NH.sub.2] + [COOH]) 0.32 0.32 0.32 0.32 0.32 0.32 Properties of PA moldability A A A A C A composition external appearance A A A A A A weathering discoloration resistance 20.0 40.0 48.0 10.0 30.0 25.0 (ΔE) flame retardancy UL94 (1.6 mm) V-0 V-0 V-0 V-0 V-0 V-0 weld strength (dry) MPa 66 62 64 64 64 64 weld strength (wet) MPa 60 56 60 53 58 58 weld strength (retention ratio) % 91 90 94 83 91 91 Rockwell hardness (dry) 101 101 101 101 100 101 Rockwell hardness (wet) 101 101 101 99 100 101 Rockwell hardness (retention ratio) % 100 100 100 98 100 100

(448) TABLE-US-00006 TABLE 5-2 Compar- Compar- Compar- Compar- Compar- Compar- Compar- ative ative ative ative ative ative ative Example Example Example Example Example Example Example Type Units 5-1 5-2 5-3 5-4 5-5 5-6 5-7 Aliphatic 5A-1 % by mass 29.0 18.5 14.4 18.0 15.0 polyamide (5A) 5A-2 % by mass Semi-aromatic 5B-1 % by mass 29.0 12.4 9.6 12.0 10.0 polyamide (5B) 5B-2 % by mass 5B-3 % by mass 5B-4 % by mass 29.0 5B-5 % by mass Flame retardant Br—PS % by mass 10.0 10.0 10.0 10.0 10.0 10.0 10.0 (5C1) Flame retardant Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 2.0 2.0 auxiliary (5C2) White pigment (5D) ZnS % by mass 2.0 2.0 2.0 0.1 7.0 2.0 2.0 Ultraviolet 5E-1 % by mass 1.0 1.0 1.0 1.0 1.0 0.0 5.0 absorber (5E) 5E-2 % by mass Polymer (5F) containing Maleic anhydride-modified % by mass 1.0 1.0 1.0 1.0 1.0 1.0 1.0 α,β-unsaturated polyphenylene ether dicarboxylic acid anhydride unit Filler (5G) GF % by mass 55.0 55.0 55.0 55.0 55.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 100.0 100.0 PA properties in PA UVA (5E)/pigment (5D) 0.50 0.50 0.50 10.00 0.14 0.00 2.50 composition tan δ peak temperature ° C. 60 135 100 115 115 115 115 Mw g/mol 35,000 20,000 32,000 29,000 29,000 29,000 29,000 Mw(5A) − Mw(5B) g/mol — — — 15,000 15,000 15,000 15,000 Mn 500 to 2000 % 1.2 2.0 1.0 1.7 1.7 1.7 1.7 Mw/Mn 2.0 2.0 2.0 2.1 2.1 2.1 2.1 [NH.sub.2]/([NH.sub.2] + [COOH]) 0.38 0.24 0.22 0.32 0.32 0.32 0.32 Properties of PA moldability A D B A A A A composition external appearance D A A A B B A weathering discoloration 10.0 50.0 25.0 51.0 60.0 55.0 8.0 resistance (ΔE) flame retardancy UL94 V-2 V-0 V-0 V-0 V-0 V-0 V-0 (1.6 mm) weld strength (dry) MPa 90 60 63 66 55 64 53 weld strength (wet) MPa 45 50 38 60 50 58 45 weld strength (retention % 50 83 60 91 91 91 85 ratio) Rockwell hardness (dry) 100 103 100 101 101 101 101 Rockwell hardness (wet) 70 103 92 101 101 101 97 Rockwell hardness % 70 100 92 100 100 100 96 (retention ratio)

(449) TABLE-US-00007 TABLE 5-3 Compar- Compar- Compar- ative ative ative Example Example Example Example Example Example Type Units 5-13 5-8 5-14 5-9 5-15 5-10 Aliphatic polyamide (5A) 5A-1 % by mass 18.5 19.4 4.7 4.5 5A-2 % by mass 18.5 19.6 Semi-aromatic polyamide 5B-1 % by mass (5B) 5B-2 % by mass 8.0 8.4 8.0 8.4 5B-3 % by mass 5B-4 % by mass 5B-5 % by mass 31.9 30.8 Flame retardant (5C1) Br—PS % by mass 12.0 12.0 3.0 3.0 12.0 12.0 Flame retardant auxiliary Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 2.0 (5C2) White pigment (5D) ZnS % by mass 2.0 2.0 2.0 3.5 2.0 2.0 Ultraviolet 5E-1 % by mass 1.5 0.2 0.4 0.2 1.5 0.0 absorber (5E) 5E-2 % by mass Polymer (5F) containing Maleic anhydride-modified % by mass 1.0 1.0 1.0 1.0 1.0 1.0 α,β-unsaturated polyphenylene ether dicarboxylic acid anhydride unit Filler (5G) GF % by mass 55.0 55.0 55.0 55.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 100.0 PA properties in PA UVA (5E)/pigment (5D) 0.75 0.10 0.20 0.06 0.75 0.00 composition tan δ peak temperature ° C. 109 109 120 120 96 96 Mw g/mol 32,600 32,600 41,000 41,000 28,860 28,860 Mw(5A) − Mw(5B) g/mol 8,000 8,000 — — −1,000 −1,000 Mn 500 to 2000 % 1.4 1.4 1.5 1.5 1.6 1.6 Mw/Mn 2.4 2.4 2.2 2.2 2.2 2.2 [NH.sub.2]/([NH.sub.2] + [COOH]) 0.45 0.45 0.45 0.45 0.45 0.45 Properties of PA moldability A A A B B B composition external appearance B C B B A A weathering discoloration resistance 38.0 50.0 35.0 40.0 38.0 80.0 (ΔE) flame retardancy UL94 (1.6 mm) V-0 V-0 V-1 V-1 V-0 V-0 weld strength (dry) MPa 73 73 78 78 63 63 weld strength (wet) MPa 56 54 48 46 47 45 weld strength (retention ratio) % 77 74 62 59 75 71 Rockwell hardness (dry) 100 100 103 103 90 90 Rockwell hardness (wet) 98 98 102 102 80 80 Rockwell hardness (retention ratio) % 98 98 99 99 89 89

(450) Tables 5-1 to 5-3 revealed that the molded articles obtained from the polyamide compositions 5-1 to 5-15 (Examples 5-1 to 5-15), which contained the aliphatic polyamide (5A) and the semi-aromatic polyamide (5B), and had a mass ratio (5E)/(5D) for the ultraviolet absorber (5E) relative to the white pigment (5D) that satisfied a range from at least 0.15 to less than 2.5 (0.15≤((5E)/(5D))<2.5), had properties including excellent external appearance, superior weld strength and Rockwell hardness upon water absorption, and excellent weathering discoloration resistance.

(451) In contrast, the molded article obtained from the polyamide composition 5-16 (Comparative Example 5-1), which did not contain the semi-aromatic polyamide (5B), had unsatisfactory external appearance, and unsatisfactory weld strength and Rockwell hardness upon water absorption.

(452) Further, the molded articles obtained from the polyamide compositions 5-17 and 5-18 (Comparative Examples 5-2 and 5-3), which contained the semi-aromatic polyamide (5B) but did not contain the aliphatic polyamide (5A), exhibited unsatisfactory results for at least one of the properties among the weathering discoloration resistance, and the weld strength and Rockwell hardness upon water absorption.

(453) Furthermore, the molded articles obtained from the polyamide compositions 5-19 to 5-25 (Comparative Examples 5-4 to 5-10), which although containing the semi-aromatic polyamide (5B), had a mass ratio (5E)/(5D) for the ultraviolet absorber (5E) relative to the white pigment (5D) that was either less than 0.15 ((5E)/(5D)<0.15) or 2.50 or greater (2.5≤(5E)/(5D)), exhibited unsatisfactory results for at least one of the properties among the external appearance, the weathering discoloration resistance, and the weld strength and Rockwell hardness upon water absorption.

(454) The above results confirmed that by using a polyamide composition of the aspect described above, a molded article having favorable weld strength and Rockwell hardness upon water absorption, favorable surface appearance, and favorable weathering discoloration resistance could be obtained.

Examples 6-1 to 2-4, Comparative Examples 2-1 to 2-7

(455) <Constituent Components>

(456) [(6A) Crystalline Polyamides]

(457) 6A-1 to 6A-5: polyamides 66 (production method as described below)

(458) 6A-6: a polyamide MXD6 resin “RENY” (a registered trademark) #6002 (manufactured by Mitsubishi Engineering-Plastics Corporation) (Tm: 238° C., Tc: 161° C.)

(459) 6A-7: a polyamide 6 SF1013A (manufactured by Ube Industries, Ltd.), (Tm: 224° C.)

(460) [(6B) Amorphous Semi-Aromatic Polyamides]

(461) 6B-1: a polyamide 6I, Mw(6B)=35,000, Mw(6B)/Mn(6B)=2

(462) 6B-2: a polyamide 6I, T-40 (manufactured by Lanxess AG), Mw(6B)=44,000, Mw(6B)/Mn(6B)=2.8

(463) [(6C) Carbon Fiber]

(464) 6C-1: carbon fiber HTC413 (manufactured by Toho Tenax Co., Ltd.)

(465) 6C-2: carbon fiber TR60NE (manufactured by Mitsubishi Rayon Co., Ltd.)

(466) <Methods for Producing Crystalline Polyamide (6A) and Amorphous Semi-Aromatic Polyamide (6B)>

(467) [Raw Materials]

(468) The crystalline polyamides (6A) and amorphous semi-aromatic polyamides (6B) used in the examples and comparative examples were produced using the compounds (a) and (b) below as appropriate.

(469) ((a) Dicarboxylic Acids)

(470) a-1: Adipic acid (ADA) (manufactured by Wako Pure Chemical Industries, Ltd.)

(471) a-2: Isophthalic acid (IPA) (manufactured by Wako Pure Chemical Industries, Ltd.)

(472) ((b) Diamine)

(473) b-1: 1,6-diaminohexane (hexamethylenediamine) (C6DA) (manufactured by Tokyo Chemical Industry Co., Ltd.)

[Synthesis Example 6-1] Synthesis of Crystalline Polyamide 6A-1 (a Polyamide 66)

(474) The polyamide polymerization reaction was performed by a “hot melt polymerization method” in the manner described below.

(475) First, 1,500 g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1,500 g of distilled water to prepare an equimolar 50% by mass homogenous aqueous solution of the raw material monomers. This aqueous solution was placed in an autoclave with an internal capacity of 5.4 L, and the autoclave was flushed with nitrogen.

(476) With the solution being stirred at a temperature of at least 110° C. but not more than 150° C., steam was gradually extracted and the solution concentration was concentrated to 70% by mass. Subsequently, the internal temperature was raised to 220° C. At this time, the pressure inside the autoclave increased to 1.8 MPa. In this state, steam was gradually extracted to maintain the pressure at 1.8 MPa, and the reaction was continued for one hour until the internal temperature reached 245° C.

(477) Next, the pressure was reduced over a period of one hour. Subsequently, the inside of the autoclave was held for 10 minutes at a reduced pressure of 650 torr (86.66 kPa) using a vacuum device. At this time, the final internal temperature of the polymerization was 265° C.

(478) Subsequently, the autoclave was pressurized with nitrogen, and the polymer was discharged in a strand-like form through a lower spinneret (nozzle), cooled in water and subjected to cutting to form pellets, and the pellets were then dried at 100° C. under a nitrogen atmosphere for 12 hours to obtain a crystalline polyamide 6A-1.

(479) The thus obtained crystalline polyamide 6A-1 (polyamide 66) had a weight average molecular weight (Mw) of 35,000, and weight average molecular weight (Mw(6A))/number average molecular weight (Mn(6A)) was 2. The polyamide 6A-1 (polyamide 66) had an amino end group concentration of 45 μmol/g, and a carboxyl end group concentration of 60 μmol/g.

[Synthesis Example 6-2] Synthesis of Crystalline Polyamide 6A-2 (a Polyamide 66)

(480) With the exception of adding an additional 900 g of adipic acid to the equimolar 50% by mass homogenous aqueous solution of the raw material monomers prepared in Synthesis Example 6-1, a crystalline polyamide 6A-2 was obtained using the same method as Synthesis Example 6-1.

(481) For the thus obtained crystalline polyamide 6A-2 (polyamide 66), Mw(6A)=35,000, and Mw(6A)/Mn(6A)=2. The crystalline polyamide 6A-2 (polyamide 66) had an amino end group concentration of 33 μmol/g, and a carboxyl end group concentration of 107 μmol/g.

[Synthesis Example 6-3] Synthesis of Crystalline Polyamide 6A-3 (a Polyamide 66)

(482) With the exception of adding an additional 900 g of hexamethylenediamine to the equimolar 50% by mass homogenous aqueous solution of the raw material monomers prepared in Synthesis Example 6-1, a crystalline polyamide 6A-3 was obtained using the same method as Synthesis Example 6-1.

(483) For the thus obtained crystalline polyamide 6A-3 (polyamide 66), Mw=35,000, and Mw/Mn=2. The crystalline polyamide 6A-3 (polyamide 66) had an amino end group concentration of 78 μmol/g, and a carboxyl end group concentration of 52 μmol/g.

[Synthesis Example 6-4] Synthesis of Crystalline Polyamide 6A-4 (a Polyamide 66)

(484) The polyamide polymerization reaction was performed by a “hot melt polymerization method” in the manner described below.

(485) First, 1,500 g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1,500 g of distilled water to prepare an equimolar 50% by mass homogenous aqueous solution of the raw material monomers. This aqueous solution was placed in an autoclave with an internal capacity of 5.4 L, and the autoclave was flushed with nitrogen.

(486) With the solution being stirred at a temperature of at least 110° C. but not more than 150° C., steam was gradually extracted and the solution concentration was concentrated to 70% by mass. Subsequently, the internal temperature was raised to 220° C. At this time, the pressure inside the autoclave increased to 1.8 MPa. In this state, steam was gradually extracted to maintain the pressure at 1.8 MPa, and the reaction was continued for one hour until the internal temperature reached 245° C.

(487) Next, the pressure was reduced over a period of one hour. Subsequently, the inside of the autoclave was held for 10 minutes at a reduced pressure of 650 torr (86.66 kPa) using a vacuum device. At this time, the final internal temperature of the polymerization was 265° C.

(488) Subsequently, the autoclave was pressurized with nitrogen, and the polymer was discharged in a strand-like form through a lower spinneret (nozzle), cooled in water and subjected to cutting to form pellets, and the pellets were then dried at 100° C. under a nitrogen atmosphere for 12 hours to obtain a polyamide. For the obtained polyamide, Mw=35,000 and Mw/Mn=2. Pellets of this polyamide were then subjected to a solid-phase polymerization at 200° C. for 6 hours, thus obtaining a crystalline polyamide 6A-4.

(489) For the thus obtained crystalline polyamide 6A-4 (polyamide 66), Mw(6A)=70,000, and Mw(6A)/Mn(6A)=3.0. The crystalline polyamide 6A-4 (polyamide 66) had an amino end group concentration of 45 μmol/g, and a carboxyl end group concentration of 60 μmol/g.

[Synthesis Example 6-5] Synthesis of Crystalline Polyamide 6A-5 (a Polyamide 66)

(490) The polyamide polymerization reaction was performed by a “hot melt polymerization method” in the manner described below.

(491) First, 1,500 g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1,500 g of distilled water to prepare an equimolar 50% by mass homogenous aqueous solution of the raw material monomers. This aqueous solution was placed in an autoclave with an internal capacity of 5.4 L, and the autoclave was flushed with nitrogen.

(492) With the solution being stirred at a temperature of at least 110° C. but not more than 150° C., steam was gradually extracted and the solution concentration was concentrated to 70% by mass. Subsequently, the internal temperature was raised to 220° C. At this time, the pressure inside the autoclave increased to 1.8 MPa. In this state, steam was gradually extracted to maintain the pressure at 1.8 MPa, and the reaction was continued for one hour until the internal temperature reached 245° C.

(493) Next, the pressure was reduced over a period of one hour. Subsequently, the inside of the autoclave was held for 5 minutes at a reduced pressure of 650 torr (86.66 kPa) using a vacuum device. At this time, the final internal temperature of the polymerization was 265° C.

(494) Subsequently, the autoclave was pressurized with nitrogen, and the polymer was discharged in a strand-like form through a lower spinneret (nozzle), cooled in water and subjected to cutting to form pellets, and the pellets were then dried at 100° C. under a nitrogen atmosphere for 12 hours to obtain a crystalline polyamide 6A-5.

(495) For the thus obtained crystalline polyamide 6A-5 (polyamide 66), Mw(6A)=25,000, and Mw(6A)/Mn(6A)=2. The crystalline polyamide 6A-5 (polyamide 66) had an amino end group concentration of 60 μmol/g, and a carboxyl end group concentration of 80 μmol/g.

[Synthesis Example 6-6] Synthesis of Amorphous Semi-Aromatic Polyamide 6B-1 (a polyamide 6I)

(496) The polyamide polymerization reaction was performed by a “hot melt polymerization method” in the manner described below.

(497) First, 1,500 g of an equimolar salt of isophthalic acid and hexamethylenediamine, and a 1.5 mol % excess of adipic acid relative to the total of all the equimolar salt components were dissolved in 1,500 g of distilled water to prepare an equimolar 50% by mass homogenous aqueous solution of raw material monomers.

(498) With the solution being stirred at a temperature of at least 110° C. but not more than 150° C., steam was gradually extracted and the solution concentration was concentrated to 70% by mass. Subsequently, the internal temperature was raised to 220° C. At this time, the pressure inside the autoclave increased to 1.8 MPa. In this state, steam was gradually extracted to maintain the pressure at 1.8 MPa, and the reaction was continued for one hour until the internal temperature reached 245° C.

(499) Next, the pressure was reduced over a period of 30 minutes. Subsequently, the inside of the autoclave was held for 10 minutes at a reduced pressure of 650 torr (86.66 kPa) using a vacuum device. At this time, the final internal temperature of the polymerization was 265° C.

(500) Subsequently, the autoclave was pressurized with nitrogen, and the polymer was discharged in a strand-like form through a lower spinneret (nozzle), cooled in water and subjected to cutting to form pellets, and the pellets were then dried at 100° C. under a nitrogen atmosphere for 12 hours, thus obtaining an amorphous semi-aromatic polyamide 6B-1.

(501) For the obtained amorphous semi-aromatic polyamide 6B-1 (polyamide 6I), Mw(6B)=35,000, and Mw(6B)/Mn(6B)=2.

(502) <Physical Properties and Evaluations>

(503) Measurements of the physical properties of the crystalline polyamides 6A-1 to 6A-7, the amorphous semi-aromatic polyamides 6B-1 and 6B-2, and each of the polyamide compositions were performed using the methods described below.

(504) Further, each of the polyamide compositions and molded articles obtained in the examples and comparative examples were subjected to various evaluations using the methods described below.

(505) [Various Physical Properties of Crystalline Polyamides (6A) and Amorphous Semi-Aromatic Polyamides (6B)]

(506) [Physical Property 1] Melting Peak Temperature Tm2 (Melting Point), Crystallization Peak Temperature Tc, and Crystallization Enthalpy ΔH

(507) These values were measured using a Diamond-DSC device manufactured by PerkinElmer, Inc., in accordance with JIS-K7121. Specifically, measurements were performed in the following manner.

(508) First, under a nitrogen atmosphere, a sample of about 10 mg of each polyamide was heated from room temperature to a temperature of at least 300 but not more than about 350° C., depending on the melting point of the sample, at a rate of temperature increase of 20C/min. The highest peak temperature of the endothermic peak (melting peak) that appeared during this process was recorded as Tm1 (° C.). Next, the temperature was maintained at the maximum heating temperature for two minutes. At this maximum temperature, the polyamide existed in a melted state. Subsequently, the sample was cooled to 30° C. at a rate of temperature reduction of 20° C./min. The exothermic peak that appeared during this process was deemed the crystallization peak, the crystallization peak temperature was recorded as Tc, and the surface area of the crystallization peak was deemed the crystallization enthalpy ΔH (J/g). Subsequently, the sample was held at 30° C. for two minutes, and was then heated from 30° C. to a temperature of at least 280 but not more than about 300° C., depending on the melting point of the sample, at a rate of temperature increase of 20° C./min. The highest peak temperature of the endothermic peak (melting peak) that appeared during this process was deemed the melting point Tm2 (° C.).

(509) [Physical Property 2] Weight Average Molecular Weight (Mw), Number Average Molecular Weight (Mn), Molecular Weight Distribution Mw/Mn

(510) The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured using gel permeation chromatography (GPC). The measurement conditions were as follows.

(511) (Measurement Conditions)

(512) Apparatus: HLC-8020 manufactured by Tosoh Corporation

(513) Solvent: hexafluoroisopropanol

(514) Standard samples: PMMA (polymethyl methacrylate) standard samples (manufactured by Polymer Laboratories Ltd.)

(515) Further, based on the obtained values, the molecular weight distribution Mw/Mn was calculated.

(516) [Physical Property 3] Polyamide Amino End Group Concentration and Carboxyl End Group Concentration

(517) (1) Amino End Group Concentration ([NH2])

(518) The amount of amino ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(519) First, 3.0 g of the polyamide was dissolved in 100 mL of a 90% by mass aqueous solution of phenol, and using the thus obtained solution, a titration was performed with 0.025 N hydrochloric acid to determine the amount of amino ends (μeq/g). The end point was determined using the reading from a pH meter.

(520) (1) Carboxyl End Group Concentration ([COOH])

(521) The amount of carboxyl ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(522) First, 4.0 g of the polyamide was dissolved in 50 mL of benzyl alcohol, and using the thus obtained solution, a titration was performed with 0.1 N NaOH to determine the amount of carboxyl ends (μeq/g). The end point was determined by the change in color of a phenolphthalein indicator.

(523) [Physical Properties of Polyamide Compositions]

(524) [Physical Property 4] Polyamide Composition Tan δ Peak Temperature

(525) Using a viscoelasticity measuring and analysis device (DVE-V4, manufactured by Rheology Co., Ltd.), a temperature variance spectrum of the dynamic viscoelasticity of a test piece prepared from each polyamide composition by cutting the parallel portion of a Type L test piece prescribed in ASTM D1822 into a short strip was measured under the conditions described below. The dimensions of the test piece were 3.1 mm (width)×2.9 mm (thickness)×15 mm (length: distance between clamps). The ratio E2/E1 between the storage modulus E1 and the loss modulus E2 was recorded as tan δ, and the highest temperature was deemed the tan δ peak temperature.

(526) (Measurement Conditions)

(527) Measurement mode: tensile

(528) Waveform: sine wave

(529) Frequency: 3.5 Hz

(530) Temperature range: at least 0° C. to not more than 180° C.

(531) Temperature increase steps: 2° C./min

(532) Static load: 400 g

(533) Displacement amplitude: 0.75 μm

(534) [Evaluations of Polyamide Compositions and Molded Articles]

(535) [Evaluation 1] Surface Gloss

(536) The 600 gloss of the central portion of a flat plate molded piece obtained in the examples and comparative examples was measured in accordance with JIS-K7150 using a gloss meter (1G320, manufactured by Horiba, Ltd.). A larger measured value was evaluated as indicating superior surface appearance.

(537) [Evaluation 2] Pellet Shape

(538) The shape of the pellets of each of the polyamide compositions obtained in the examples and comparative examples was inspected visually. The evaluation criteria for the pellet shape were as follows. Obtaining a favorable pellet shape was evaluated as leading to an improvement in productivity.

(539) (Evaluation Criteria)

(540) 5: no fluff, circular cylindrical pellets of substantially uniform shape

(541) 4: no fluff, circular cylindrical pellets of mostly uniform shape

(542) 3: some slight fluff, circular cylindrical pellets of mostly uniform shape

(543) 2: fluff occurs, circular cylindrical pellets of non-uniform shape

(544) 1: fluff occurs, pellets of irregular shape

(545) [Evaluation 3] Amount of Cutting Chips

(546) The amount of cutting chips generated when producing each of the polyamide compositions in the examples and comparative examples was evaluated visually. The evaluation criteria for the amount of cutting chips were as follows. A smaller amount of cutting chips was evaluated as leading to an improvement in productivity.

(547) (Evaluation Criteria)

(548) 5: almost no cutting chips

(549) 4: some fine cutting chips exist

(550) 3: fine cutting chips are noticeable, but no large cutting chips exist

(551) 2: considerable number of fine cutting chips, and some large cutting chips exist

(552) 1: considerable numbers of fine cutting chips and large cutting chips exist

(553) [Evaluation 4] Tensile Strength

(554) Using the molded piece of multipurpose test piece type A obtained in each of the examples and comparative examples, a tensile test was performed in accordance with ISO 527 under conditions including temperature conditions of 80° C. and a tension rate of 50 mm/min, thereby measuring the tensile yield stress, which was recorded as the tensile strength.

(555) [Evaluation 5] Flexural Strength

(556) The multipurpose test piece type A obtained in each of the examples and comparative examples was cut to obtain a test piece having dimensions of length: 80 mm×width: 10 mm×thickness: 4 mm. Using this test piece, the flexural strength was measured in accordance with ISO 178.

(557) [Evaluation 6] Notched Charpy Impact Strength

(558) The multipurpose test piece type A obtained in each of the examples and comparative examples was cut to obtain a test piece having dimensions of length: 80 mm×width: 10 mm×thickness: 4 mm. Using this test piece, the notched Charpy impact strength (kJ/m.sup.2) was measured in accordance with ISO 179.

(559) <Production of Polyamide Compositions>

Examples 6-1 to 6-11 and Comparative Examples 6-1 to 6-5

(560) (1) Production of Polyamide Composition

(561) Using the crystalline polyamides (6A) described above, the amorphous semi-aromatic polyamides (6B) described above, and the carbon fiber (6C) described above in the formulations and proportions shown below in Table 6-1, various polyamide compositions were produced using the methods described below.

(562) The crystalline polyamides 6A-1 to 6A-5 and the amorphous semi-aromatic polyamide 6B-1 synthesized above were dried under a stream of nitrogen to reduce the moisture content to about 0.2% by mass before being used as raw materials for the polyamide compositions.

(563) A twin-screw extruder “ZSK-26MC” manufactured by Coperion GmbH (Germany) was used as the polyamide composition production apparatus.

(564) The twin-screw extruder had an upstream supply port on the first barrel from the upstream side of the extruder, had a downstream first supply port on the sixth barrel, and had a downstream second supply port on the ninth barrel. Further, in the twin-screw extruder, the value of extruder length (L1)/screw diameter (D1) was 48, and the number of barrels was 12.

(565) In the twin-screw extruder, the temperature from the upstream supply port to the die was set to the melting point Tm2 of each polyamide +20° C., the screw rotational rate was set to 250 rpm, and the discharge rate was set to 25 kg/h.

(566) In a specific production method using the above production apparatus, the crystalline polyamide (6A) and the amorphous semi-aromatic polyamide (6B) were dry-blended and then supplied to the upstream supply port of the twin-screw extruder, while the carbon fiber (6C) was supplied from the downstream first supply port of the twin-screw extruder, and the melt-kneaded product extruded from the die head was cooled in a strand-like form and then pelletized to obtain pellets of a polyamide composition. The obtained pellets of the polyamide composition were dried under a stream of nitrogen to reduce the moisture content within the polyamide composition to not more than 500 ppm.

(567) (2) Production of Molded Article 1 (Flat Plate Molded Piece)

(568) Next, using the pellets of each of the obtained polyamide compositions, and using an injection molding machine (NEX50III-5EG, manufactured by Nissei Plastic Industrial Co., Ltd.) with the production conditions set as described below, the injection pressure and injection speed were adjusted appropriately to achieve a fill time of 1.6±0.1 seconds, and a flat plate molded piece (6 cm×9 cm, thickness: 2 mm) was produced. The surface gloss of the thus obtained flat plate molded piece was evaluated using the method described above. The results are shown in Table 6-1 and Table 6-2.

(569) (Production Conditions)

(570) Cooling time: 25 seconds

(571) Screw rotational rate: 200 rpm

(572) Mold temperature: tan δ peak temperature+5° C.

(573) Cylinder temperature: at least (Tm2+10°) C but not more than (Tm2+30°) C

(574) (3) Production of Molded Article 2 (Multipurpose Test Piece Type A Molded Piece)

(575) Next, using the pellets of each of the obtained polyamide compositions, and using an injection molding machine (PS-40E, manufactured by Nissei Plastic Industrial Co., Ltd.), molded pieces of the multipurpose test piece type A were molded in accordance with ISO 3167. The specific molding conditions included an injection+holding time of 25 seconds, a cooling time of 15 seconds, a mold temperature of 80° C., and a melted resin temperature set to the high temperature-side melting peak temperature (Tm2) for the polyamides+20° C. Using the thus obtained molded pieces of multipurpose test piece type A, the tensile strength, the flexural strength and the notched Charpy impact strength were evaluated using the methods described above. The results are shown in Table 6-1 and Table 6-2. In Table 6-1 and Table 6-2, the symbol “-” for the weight average molecular weight (Mw) indicates that no measurement was performed.

(576) TABLE-US-00008 TABLE 6-1 Example Example Example Example Example Example Example Example Comparative Comparative 6-1 6-2 6-3 6-4 6-5 6-6 6-7 6-8 Example 6-1 Example 6-2 Component 6A-1 45 45 45 60 6A-2 45 6A-3 45 6A-4 45 6A-5 45 6A-6 45 6A-7 60 6B-1 15 15 15 15 15 15 15 6B-2 15 6C-1 40 40 40 40 40 40 40 40 40 6C-2 40 Evaluation results Mw 32,000 32,000 32,000 32,000 33,500 30,000 — 34,500 32,000 — tan δ peak temperature 125 125 125 125 125 125 120 125 80 85 Surface gloss 4 4 4 4 4 5 4 4 1 3 Pellet shape 3 3 3 3 4 3 4 3 1 2 Cutting chips 4 4 5 4 4 4 4 3 1 3 Tensile strength [MPa] 287 289 285 291 290 284 275 283 249 265 Flexural strength [MPa] 451 453 454 450 449 452 420 455 394 390 Notched Charpy [kJ/m.sup.2] 8.7 8.5 8.7 8.9 8.8 8.7 9.0 8.9 10.2 8.8

(577) TABLE-US-00009 TABLE 6-2 Example Example Example Comparative Comparative Comparative 6-9 6-10 6-11 Example 6-3 Example 6-4 Example 6-5 Component 6A-1 67.5 60 52.5 90 80 70 6A-2 6A-3 6A-4 6A-5 6A-6 6A-7 6B-1 13.5 20 17.5 6B-2 6C-1 10 20 30 10 20 30 6C-2 Evaluation results Mw 32,000 32,000 32,000 32,000 32,000 32,000 tan δ peak temperature 125 125 125 80 80 80 Surface gloss 5 5 5 5 3 1 Pellet shape 5 4 4 4 3 2 Cutting chips 5 4 3 3 2 1 Tensile strength [MPa] 181 241 269 179 238 267 Flexural strength [MPa] 256 335 399 255 332 394 Notched Charpy [kJ/m.sup.2] 4.8 8.1 10.8 4.6 7.9 10.8

(578) Table 6-1 and Table 6-2 revealed that the polyamide compositions (of Examples 6-1 to 6-11), which contained the crystalline polyamide (6A), the amorphous semi-aromatic polyamide (6B) and the carbon fiber (6C), wherein the amorphous semi-aromatic polyamide (6B) included at least 75 mol % of isophthalic acid units among all of the dicarboxylic acid units that constituted the amorphous semi-aromatic polyamide (6B), and included at least 50 mol % of a diamine unit having at least 4 but not more than 10 carbon atoms among all of the diamine units that constituted the amorphous semi-aromatic polyamide (6B), exhibited superior surface appearance and pellet shape, and reduced cutting chip generation, while maintaining favorable results for each of the mechanical properties (the tensile strength, flexural strength and notched Charpy strength), when compared with the polyamide compositions (of Comparative Examples 6-1 to 6-5) that did not have the above composition.

(579) Further, based on a comparison of the polyamide compositions having differing amounts of the crystalline polyamide 6A-1 (Examples 6-1, and 6-9 to 6-11), it was evident that increasing the amount of the crystalline polyamide 6A-1 tended to yield more favorable results for the pellet shape, better reduction of cutting chips, and improved surface gloss for the molded articles.

Examples 7-1 to 2-4, Comparative Examples 2-1 to 2-7

(580) <Constituent Components>

(581) [(7A) Aliphatic Polyamides]

(582) 7A-1: a polyamide 66 (the same polyamide as 1A-1 above was used)

(583) 7A-2: a polyamide 6 (SF1013A manufactured by Ube Industries, Ltd., Mw=26,000, Mw/Mn=2.0)

(584) The above polyamides were dried under a stream of nitrogen to reduce the moisture content to about 0.2% by mass before being used as raw materials for the polyamide compositions.

(585) [(7B) Semi-Aromatic Polyamides]

(586) 7B-1: a polyamide 6I (the same polyamide as 1B-2 above was used)

(587) 7B-2: a polyamide 6I/6T (G21 manufactured by Ems Group, Mw=27,000, Mw/Mn=2.2, VR=27, Mw/VR=1,000, proportion of isophthalic acid in dicarboxylic acid units: 70 mol %)

(588) 7B-3: a polyamide 6I (high molecular weight) (the same polyamide as 2B-4 above was used)

(589) 7B-4: a polyamide 66/6I (the same polyamide as 1B-1 above was used)

(590) 7B-5: a polyamide MXD6 (product name: Toyobo Nylon T-600, manufactured by Toyobo Co., Ltd., Mw=43,000, Mw/Mn=2.2, VR=28, Mw/VR=1,536, proportion of isophthalic acid in dicarboxylic acid units: 0 mol %)

(591) The above polyamides were dried under a stream of nitrogen to reduce the moisture content to about 0.2% by mass before being used as raw materials for the polyamide compositions.

(592) [(7C1) Flame Retardant]

(593) 7C1: a brominated polystyrene (product name “SAYTEX (a registered trademark) HP-7010G” manufactured by Albemarle Corporation (bromine content as determined by elemental analysis: 67% by mass)) (hereafter sometimes abbreviated as “Br-PS”)

(594) [(7C2) Flame Retardant Auxiliary]

(595) 7C2: Diantimony trioxide (product name “Antimony Trioxide” manufactured by Daiichi F. R. co., Ltd.) (hereafter sometimes abbreviated as “Sb.sub.2O.sub.3”)

(596) [(7D) Ultraviolet Absorbers]

(597) 7D-1: a benzotriazole-based ultraviolet absorber (UVA-1) (ADEKA STAB LA-31)

(598) 7D-2: a triazine-based ultraviolet absorber (UVA-2) (Tinuvin 1600)

(599) [(7E) Polymer Containing an α,β-Unsaturated Dicarboxylic Acid Anhydride Unit]

(600) 7E: a maleic anhydride-modified polyphenylene ether (the same compound as 2E above was used)

(601) [(7F) Filler]

(602) 7F: Glass fiber (GF) (product name “ECS03T275H” manufactured by Nippon Electric Glass Co., Ltd., average fiber diameter: 10 μmφ, cut length: 3 mm)

(603) <Physical Properties and Evaluations>

(604) First, the polyamide composition pellets obtained in the examples and comparative examples were dried under a stream of nitrogen to reduce the moisture content within the polyamide composition to not more than 500 ppm. Each of the polyamide compositions for which the moisture content had been adjusted was then subjected to various physical property measurements and various evaluations using the methods described below.

(605) [Physical Property 1] Tan δ Peak Temperature

(606) Using a PS40E injection molding machine manufactured by Nissei Plastic Industrial Co., Ltd., with the cylinder temperature set to 290° C. and the mold temperature set to 100° C., a molded article was molded in accordance with JIS-K7139 under injection molding conditions including an injection time of 10 seconds and a cooling time of 10 seconds. This molded article was measured under the following conditions using a dynamic viscoelasticity evaluation device (EPLEXOR 500N, manufactured by Gabo GmbH).

(607) (Measurement Conditions)

(608) Measurement mode: tensile

(609) Measurement frequency: 8.00 Hz

(610) Rate of temperature increase: 3° C./min

(611) Temperature range: −100 to 250° C.

(612) The ratio (E2/E1) between the storage modulus E1 and the loss modulus E2 was recorded as tan δ, and the highest temperature was deemed the tan δ peak temperature.

(613) [Physical Property 2] Molecular Weight and End Structures of Polyamide Compositions (1) Number Average Molecular Weight and Weight Average Molecular Weight of Polyamide Compositions

(614) The number average molecular weight (Mn) and weight average molecular weight (Mw) of each polyamide composition obtained in the examples and comparative examples were measured by GPC (gel permeation chromatography) under the conditions described below. Based on these values, Mw(7A)−Mw(7B) and the molecular weight distribution Mw/Mn were calculated. Further, the amount (% by mass) of polyamides having a number average molecular weight Mn of at least 500 but not more than 2,000 among all of the polyamides in the polyamide composition was calculated from the elution curve (vertical axis: signal strength obtained from detector, horizontal axis: elution time) of each sample obtained using GPC, based on the surface area of the region bounded by the baseline and the elution curve for number average molecular weights from at least 500 to less than 2,000, and the surface area of the region bounded by the baseline and the elution curve for all the number average molecular weights.

(615) (Measurement Conditions)

(616) Measurement apparatus: HLC-8020 manufactured by Tosoh Corporation

(617) Solvent: hexafluoroisopropanol solvent

(618) Standard samples: PMMA (polymethyl methacrylate) standard samples (manufactured by Polymer Laboratories Ltd.)

(619) GPC columns: TSKgel GMHHR-M and G1000HHR

(620) (2) Amount of Amino Ends ([NH2])

(621) In the polyamide compositions obtained in the examples and comparative examples, the amount of amino ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(622) First, 3.0 g of each polyamide composition was dissolved in 100 mL of a 90% by mass aqueous solution of phenol, and using the thus obtained solution, a titration was performed with 0.025 N hydrochloric acid to determine the amount of amino ends (μeq/g). The end point was determined using the reading from a pH meter.

(623) (3) Amount of Carboxyl Ends ([COOH])

(624) In the polyamide compositions obtained in the examples and comparative examples, the amount of carboxyl ends bonded to polymer ends was measured by a neutralization titration in the manner described below.

(625) First, 4.0 g of the polyamide composition was dissolved in 50 mL of benzyl alcohol, and using the thus obtained solution, a titration was performed with 0.1 N NaOH to determine the amount of carboxyl ends (μeq/g). The end point was determined by the change in color of a phenolphthalein indicator.

(626) (4) Ratio of Amino Ends to Total Amount of Active Ends ([NH2]/[(NH2]+[COOH])

(627) Based on the amount of amino ends ([NH.sub.2]) and the amount of carboxyl ends ([COOH]) obtained in (2) and (3), the total amount of active ends ([NH2]+[COOH]) and the ratio of the amount of amino ends relative to the total amount of active ends ([NH.sub.2]/[(NH.sub.2]+[COOH])) were calculated.

(628) [Physical Property 3] Formic Acid Solution Viscosity VR

(629) Each of the semi-aromatic polyamides 7B-1 to 7B-5 was dissolved in formic acid, and measurement was performed in accordance with ASTM-D789.

(630) [Physical Property 4] Mass Ratio of Ultraviolet Absorber (7D) Relative to Halogen Element ((7D)/Halogen Element)

(631) (1) Quantification of Halogen Content by Elemental Analysis>

(632) The polyamide composition was incinerated in a flask that had been flushed with high-purity oxygen, the generated gas was captured using an absorbent, and the halogen element within the capture liquid was quantified by a potentiometric titration with 1/100 N silver nitrate solution.

(633) In those cases where the composition included a plurality of halogen elements, each element was first separated by ion chromatography, and then quantified using the above potentiometric titration method.

(634) (2) Calculation of (7D)/Halogen Element

(635) Using the halogen content quantified in (1) above, and the blend amount of the ultraviolet absorber (7D) added to each polyamide composition, the value of {(7D)/Halogen Element} was calculated.

(636) [Evaluation 1] Moldability and External Appearance

(637) (1) Production of Molded Articles

(638) An “FN3000” apparatus manufactured by Nissei Plastic Industrial Co., Ltd. was used. With the cylinder temperature set to 290° C. and the mold temperature set to 100° C., molding was conducted for 100 shots using each polyamide composition under injection molding conditions including an injection time of 10 seconds and a cooling time of 10 seconds, thus obtaining molded articles (ISO test pieces).

(639) (2) Evaluation of Moldability

(640) The moldability was evaluated against the following evaluation criteria, on the basis of the percentage of the 100 shots in which the molded article stuck to the mold during mold release following molding.

(641) (Evaluation Criteria)

(642) A: 10% or less

(643) B: greater than 10% but not more than 20%

(644) C: greater than 20% but not more than 50%

(645) D: greater than 50%

(646) (3) Evaluation of MD (Mold Deposits) During Molding

(647) The molding described above in (1) was repeated for 100 consecutive shots, and following completion of the molding, the gas vent was inspected visually.

(648) The evaluation criteria for MD during molding were as listed below. The ability to obtain molded articles without problems was evaluated as leading to an improvement in productivity.

(649) (Evaluation Criteria)

(650) A: no deposits observed on gas vent

(651) B: some deposits observed on gas vent

(652) C: deposits observed on gas vent, with a blockage beginning to occur

(653) D: deposits observed on gas vent, with vent blocked

(654) (4) Evaluation of External Appearance

(655) In terms of the external appearance of the obtained molded articles, the 60° gloss of the grip portion of each molded article was measured in accordance with JIS-K7150 using a gloss meter (1G320, manufactured by Horiba, Ltd.). Based on the measured surface gloss, the external appearance was evaluated against the following criteria.

(656) (Evaluation Criteria)

(657) A: at least 60

(658) B: at least 55 but less than 60

(659) C: at least 50 but less than 55

(660) D: less than 50

(661) [Evaluation 2] Weathering Discoloration Resistance

(662) Using a WEL-SUN-DCH sunshine carbon-arc lamp weather resistance testing apparatus manufactured by Suga Test Instruments Co., Ltd., a molded article obtained in [Evaluation 1] was exposed for 100 hours under conditions including a black panel temperature of 65° C., a humidity of 50% RH, and no water spray. The evaluation method used following the weather resistance test involved measuring the color tone of the molded article before and after exposure, and determining the color difference using a color difference meter ND-300A manufactured by Nippon Denshoku Industries Co., Ltd. A smaller color difference (ΔE) was evaluated as indicating more favorable weather resistance.

(663) [Evaluation 3] Tensile Strength

(664) Using the ISO test pieces from shots 20 to 25 obtained in the above evaluation of the moldability and external appearance, the flexural modulus was measured in accordance with ISO 527. The average value of n=6 was recorded as the measured value.

(665) [Evaluation 4] Flexural Modulus

(666) Using the ISO test pieces from shots 20 to 25 obtained in the above evaluation of the moldability and external appearance, the flexural modulus was measured in accordance with ISO 178. The average value of n=6 was recorded as the measured value.

(667) [Evaluation 5] Flame Retardancy

(668) Measurements were performed using the method UL94 (a standard prescribed by Underwriters Laboratories Inc., USA). The test piece (length: 127 mm, width: 12.7 mm, thickness: 1.6 mm) was prepared by fitting a mold for the UL test piece (mold temperature=100° C.) to an injection molding machine (PS40E manufactured by Nissei Plastic Industrial Co., Ltd.) and molding each polyamide composition at a cylinder temperature of 290° C. The injection pressure was set to a value of the complete filling pressure when molding the UL test piece+2%. The flame retardancy classifications used were those prescribed in the UL94 standard (vertical flame test).

[Example 7-1] Production of Polyamide Composition 7-1

(669) Using a TEM 35 mm twin-screw extruder manufactured by Toshiba Machine Co., Ltd. (temperature setting: 280° C., screw rotational rate: 300 rpm), a mixture obtained by blending (7A) the aliphatic polyamide 7A-1, (7B) the semi-aromatic polyamide 7B-1, (7C1) flame retardant, (7C2) the flame retardant auxiliary, (7D) the ultraviolet absorber 7D-1, and (7E) the polymer containing an α,β-unsaturated dicarboxylic acid anhydride unit was supplied to a top feed port provided in the most upstream portion of the extruder. Further, the filler (7F) was supplied from a side feed port on the downstream side of the extruder (at a point where the resins supplied from the top feed port had reached a satisfactorily melted state). The melt kneaded product extruded from the die head was cooled in a strand-like state and then pelletized to obtain pellets of a polyamide composition 7-1. The blend amounts were 20.1% by mass for (7A) the aliphatic polyamide 7A-1, 10.9% by mass for (7B) the semi-aromatic polyamide 7B-1, 10.0% by mass for the flame retardant (7C1), 2.0% by mass for the flame retardant auxiliary (7C2), 1.0% by mass for (7D) the ultraviolet absorber 7D-1, 1.0% by mass for (7F) the polymer containing an α,β-unsaturated dicarboxylic acid anhydride unit, and 55% by mass for the filler (7F).

(670) Further, using the pellets of the thus obtained polyamide composition 7-1, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-1.

[Example 7-2] Production of Polyamide Composition 7-2

(671) With the exception of altering the blend amounts to include 18.5% by mass of (7A) the aliphatic polyamide 7A-1 and 12.5% by mass of (7B) the semi-aromatic polyamide 7B-1, pellets of a polyamide composition 7-2 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-2, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-1.

[Example 7-3] Production of Polyamide Composition 7-3

(672) With the exception of altering the blend amounts to include 18.5% by mass of (7A) the aliphatic polyamide 7A-1, 0% by mass of (7B) the semi-aromatic polyamide 7B-1, and 12.5% by mass of (7B) the semi-aromatic polyamide 7B-3, pellets of a polyamide composition 7-3 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-3, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-1.

[Example 7-4] Production of Polyamide Composition 7-4

(673) With the exception of altering the blend amounts to include 19.2% by mass of (7A) the aliphatic polyamide 7A-1, 12.8% by mass of (7B) the semi-aromatic polyamide 7B-1, and 9.0% by mass of the flame retardant (7C1), pellets of a polyamide composition 7-4 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-4, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-1.

[Example 7-5] Production of Polyamide Composition 7-5

(674) With the exception of altering the blend amounts to include 17.1% by mass of (7A) the aliphatic polyamide 7A-1, 11.4% by mass of (7B) the semi-aromatic polyamide 7B-1, 12.0% by mass of the flame retardant (7C1), and 1.5% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-5 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-5, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-1.

[Example 7-6] Production of Polyamide Composition 7-6

(675) With the exception of altering the blend amounts to include 17.3% by mass of (7A) the aliphatic polyamide 7A-1, 11.7% by mass of (7B) the semi-aromatic polyamide 7B-1, and 12.0% by mass of the flame retardant (7C1), pellets of a polyamide composition 7-6 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-6, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown in Table 7-1.

[Example 7-7] Production of Polyamide Composition 7-7

(676) With the exception of altering the blend amounts to include 18.7% by mass of (7A) the aliphatic polyamide 7A-1, 12.5% by mass of (7B) the semi-aromatic polyamide 7B-1, and 0.8% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-7 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-7, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown in Table 7-1.

[Example 7-8] Production of Polyamide Composition 7-8

(677) With the exception of altering the blend amounts to include 18.0% by mass of (7A) the aliphatic polyamide 7A-1, 12.0% by mass of (7B) the semi-aromatic polyamide 7B-1, and 2.0% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-8 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-8, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown in Table 7-1.

[Example 7-9] Production of Polyamide Composition 7-9

(678) With the exception of altering the blend amounts to include 17.4% by mass of (7A) the aliphatic polyamide 7A-1, 11.6% by mass of (7B) the semi-aromatic polyamide 7B-1, and 3.0% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-9 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-9, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown in Table 7-1.

[Example 7-10] Production of Polyamide Composition 7-10

(679) With the exception of altering the blend amounts to include 17.0% by mass of (7A) the aliphatic polyamide 7A-1 and 14.0% by mass of (7B) the semi-aromatic polyamide 7B-1, pellets of a polyamide composition 7-10 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-10, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-1.

[Example 7-11] Production of Polyamide Composition 7-11

(680) With the exception of altering the blend amounts to include 18.5% by mass of (7A) the aliphatic polyamide 7A-1, 12.5% by mass of (7B) the semi-aromatic polyamide 7B-1, and 1.0% by mass of (7D) the ultraviolet absorber 7D-2, pellets of a polyamide composition 7-11 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-11, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown in Table 7-1.

[Example 7-12] Production of Polyamide Composition 7-12

(681) With the exception of altering the blend amounts to include 19.9% by mass of (7A) the aliphatic polyamide 7A-1, 0% by mass of (7B) the semi-aromatic polyamide 7B-1, 8.6% by mass of the semi-aromatic polyamide 7B-2, 12.0% by mass of the flame retardant (7C1), and 1.5% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-12 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-12, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-3.

[Example 7-13] Production of Polyamide Composition 7-13

(682) With the exception of altering the blend amounts to include 5.0% by mass of (7A) the aliphatic polyamide 7A-1, 0% by mass of (7B) the semi-aromatic polyamide 7B-1, 33.6% by mass of (7B) the semi-aromatic polyamide 7B-5, 3.0% by mass of the flame retardant (7C1), and 0.4% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-13 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-13, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-3.

[Example 7-14] Production of Polyamide Composition 7-14

(683) With the exception of altering the blend amounts to include 0% by mass of (7A) the aliphatic polyamide 7A-1, 19.9% by mass of (7A) the aliphatic polyamide 7A-2, 0% by mass of (7B) the semi-aromatic polyamide 7B-1, 8.6% by mass of (7B) the semi-aromatic polyamide 7B-2, 12.0% by mass of the flame retardant (7C1), and 1.5% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-14 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-14, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-3.

[Comparative Example 7-1] Production of Polyamide Composition 7-15

(684) With the exception of altering the blend amounts to include 31.0% by mass of (7A) the aliphatic polyamide 7A-1 and 0% by mass of (7B) the semi-aromatic polyamide 7B-1, pellets of a polyamide composition 7-15 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-15, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-2.

[Comparative Example 7-2] Production of Polyamide Composition 7-16

(685) With the exception of altering the blend amounts to include 0% by mass of (7A) the aliphatic polyamide 7A-1 and 31.0% by mass of (7B) the semi-aromatic polyamide 7B-1, pellets of a polyamide composition 7-16 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-16, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-2.

[Comparative Example 7-3] Production of Polyamide Composition 7-17

(686) With the exception of altering the blend amounts to include 0% by mass of (7A) the aliphatic polyamide 7A-1, 0% by mass of (7B) the semi-aromatic polyamide 7B-1, and 31.0% by mass of (7B) the semi-aromatic polyamide 7B-4, pellets of a polyamide composition 7-17 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-17, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-2.

[Comparative Example 7-4] Production of Polyamide Composition 7-18

(687) With the exception of altering the blend amounts to include 19.2% by mass of (7A) the aliphatic polyamide 7A-1, 12.8% by mass of (7B) the semi-aromatic polyamide 7B-1, and 0% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-18 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-18, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-2.

[Comparative Example 7-5] Production of Polyamide Composition 7-19

(688) With the exception of altering the blend amounts to include 16.2% by mass of (7A) the aliphatic polyamide 7A-1, 10.8% by mass of (7B) the semi-aromatic polyamide 7B-1, and 5.0% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-19 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-19, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-2.

[Comparative Example 7-6] Production of Polyamide Composition 7-20

(689) With the exception of altering the blend amounts to include 20.8% by mass of (7A) the aliphatic polyamide 7A-1, 0% by mass of (7B) the semi-aromatic polyamide 7B-1, 9.0% by mass of (7B) the semi-aromatic polyamide 7B-2, 12.0% by mass of the flame retardant (7C1), and 0.2% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-20 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-20, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-3.

[Comparative Example 7-7] Production of Polyamide Composition 7-21

(690) With the exception of altering the blend amounts to include 5.0% by mass of (7A) the aliphatic polyamide 7A-1, 0% by mass of (7B) the semi-aromatic polyamide 7B-1, 33.8% by mass of (7B) the semi-aromatic polyamide 7B-5, 3.0% by mass of the flame retardant (7C1), and 0.2% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-21 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-21, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-3.

[Comparative Example 7-8] Production of Polyamide Composition 7-22

(691) With the exception of altering the blend amounts to include 0% by mass of (7A) the aliphatic polyamide 7A-1, 20.9% by mass of (7A) the aliphatic polyamide 7A-2, 0% by mass of (7B) the semi-aromatic polyamide 7B-1, 8.9% by mass of (7B) the semi-aromatic polyamide 7B-2, 12.0% by mass of the flame retardant (7C1), and 0.2% by mass of (7D) the ultraviolet absorber 7D-1, pellets of a polyamide composition 7-22 were obtained using the same method as Example 7-1. Using the pellets of the thus obtained polyamide composition 7-22, molded articles were produced using the methods described above, and measurements of the various physical properties and various evaluations were performed. The evaluation results are shown below in Table 7-3.

(692) TABLE-US-00010 TABLE 7-1 Example Example Example Example Example Example Type Units 7-1 7-2 7-3 7-4 7-5 7-6 Aliphatic polyamide (7A) 7A-1 % by mass 20.1 18.5 18.5 19.2 17.1 17.3 7A-2 % by mass Semi-aromatic polyamide 7B-1 % by mass 10.9 12.5 12.8 11.4 11.7 (7B) 7B-2 % by mass 7B-3 % by mass 12.5 7B-4 % by mass 7B-5 % by mass Flame retardant (7C1) Br—PS % by mass 10.0 10.0 10.0 9.0 12.0 12.0 Flame retardant auxiliary Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 2.0 (7C2) Ultraviolet absorber (7D) 7D-1 % by mass 1.0 1.0 1.0 1.0 1.5 1.0 7D-2 % by mass Polymer (7E) containing Maleic anhydride-modified % by mass 1.0 1.0 1.0 1.0 1.0 1.0 α,β-unsaturated polyphenylene ether dicarboxylic acid anhydride unit Filler (7F) GF % by mass 55.0 55.0 55.0 55.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 100.0 PA properties in PA UVA (7D)/halogen content 0.15 0.15 0.15 0.17 0.19 0.12 composition tan δ peak temperature ° C. 111 115 115 112 117 117 Mw g/mol 33,000 32,000 34,000 32,000 32,000 32,000 Mw(7A) − Mw(7B) g/mol 20,000 20,000 15,000 20,000 20,000 20,000 Mn 500 to 2000 % 1.6 1.7 1.7 1.7 1.7 1.7 Mw/Mn 2.1 2.1 2.1 2.1 2.1 2.1 [NH.sub.2]/([NH.sub.2] + [COOH]) 0.33 0.32 0.32 0.32 0.32 0.32 Properties of PA moldability A A A A A A composition MD during molding A A A A A A external appearance A A A A A A weathering discoloration resistance 27.0 30.0 30.0 28.0 37.0 48.0 (ΔE) flame retardancy UL94 (1.6 mm) V-0 V-0 V-0 V-0 V-0 V-0 tensile strength MPa 240 231 233 236 227 222 flexural modulus GPa 20.0 20.4 20.5 20.0 21.3 21.2 Example Example Example Example Example Type Units 7-7 7-8 7-9 7-10 7-11 Aliphatic polyamide (7A) 7A-1 % by mass 18.7 18.0 17.4 17.0 18.5 7A-2 % by mass Semi-aromatic polyamide 7B-1 % by mass 12.5 12.0 11.6 14.0 12.5 (7B) 7B-2 % by mass 7B-3 % by mass 7B-4 % by mass 7B-5 % by mass Flame retardant (7C1) Br—PS % by mass 10.0 10.0 10.0 10.0 10.0 Flame retardant auxiliary Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 (7C2) Ultraviolet absorber (7D) 7D-1 % by mass 0.8 2.0 3.0 1.0 7D-2 % by mass 1.0 Polymer (7E) containing Maleic anhydride-modified % by mass 1.0 1.0 1.0 1.0 1.0 α,β-unsaturated polyphenylene ether dicarboxylic acid anhydride unit Filler (7F) GF % by mass 55.0 55.0 55.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 PA properties in PA UVA (7D)/halogen content 0.12 0.30 0.45 0.15 0.15 composition tan δ peak temperature ° C. 115 115 115 115 115 Mw g/mol 32,000 32,000 32,000 31,000 29,000 Mw(7A) − Mw(7B) g/mol 20,000 20,000 20,000 20,000 15,000 Mn 500 to 2000 % 1.7 1.7 1.7 1.8 1.7 Mw/Mn 2.1 2.1 2.1 2.1 2.1 [NH.sub.2]/([NH.sub.2] + [COOH]) 0.32 0.32 0.32 0.31 0.32 Properties of PA moldability A A A A A composition MD during molding A A B A A external appearance A A A A A weathering discoloration resistance 45.0 25.0 10.0 35.0 25.0 (ΔE) flame retardancy UL94 (1.6 mm) V-0 V-0 V-0 V-0 V-0 tensile strength MPa 230 230 228 225 233 flexural modulus GPa 20.5 20.3 20.1 21.0 20.5

(693) TABLE-US-00011 TABLE 7-2 Comparative Comparative Comparative Comparative Comparative Type Units Example 7-1 Example 7-2 Example 7-3 Example 7-4 Example 7-5 Aliphatic polyamide (7A) 7A-1 % by mass 31.0 19.2 16.2 7A-2 % by mass Semi-aromatic polyamide 7B-1 % by mass 31.0 12.8 10.8 (7B) 7B-2 % by mass 7B-3 % by mass 7B-4 % by mass 31.0 7B-5 % by mass Flame retardant (7C1) Br—PS % by mass 10.0 10.0 10.0 10.0 10.0 Flame retardant auxiliary Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 (7C2) Ultraviolet absorber (7D) 7D-1 % by mass 1.0 1.0 1.0 0.0 5.0 7D-2 % by mass Polymer (7E) containing Maleic anhydride-modified % by mass 1.0 1.0 1.0 1.0 1.0 α,β-unsaturated polyphenylene ether dicarboxylic acid anhydride unit Filler (7F) GF % by mass 55.0 55.0 55.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 PA properties in PA UVA (7D)/halogen content 0.15 0.15 0.15 0.00 0.75 composition tan δ peak temperature ° C. 60 135 100 115 115 Mw g/mol 40,000 20,000 32,000 32,000 32,000 Mw(7A) − Mw(7B) g/mol — — — 20,000 20,000 Mn 500 to 2000 % 1.2 2.0 1.0 1.7 1.7 Mw/Mn 2.0 2.0 2.0 2.1 2.1 [NH.sub.2]/([NH.sub.2] + [COOH]) 0.38 0.24 0.22 0.32 0.32 Properties of PA moldability A D B A A composition MD during molding A C A A C external appearance D A A B A weathering discoloration 10.0 50.0 25.0 55.0 8.0 resistance (ΔE) flame retardancy UL94 (1.6 mm) V-2 V-0 V-0 V-0 V-0 tensile strength MPa 210 200 219 229 223 flexural modulus GPa 19.0 22.0 19.5 20.4 19.6

(694) TABLE-US-00012 TABLE 7-3 Example Comparative Example Comparative Example Comparative Type Units 7-12 Example 7-6 7-13 Example 7-7 7-14 Example 7-8 Aliphatic polyamide (7A) 7A-1 % by mass 19.9 20.8 5.0 5.0 7A-2 % by mass 19.9 20.9 Semi-aromatic polyamide 7B-1 % by mass (7B) 7B-2 % by mass 8.6 9.0 8.6 8.9 7B-3 % by mass 7B-4 % by mass 7B-5 % by mass 33.6 33.8 Flame retardant (7C1) Br—PS % by mass 12.0 12.0 3.0 3.0 12.0 12.0 Flame retardant auxiliary Sb.sub.2O.sub.3 % by mass 2.0 2.0 2.0 2.0 2.0 2.0 (7C2) Ultraviolet absorber (7D) 7D-1 % by mass 1.5 0.2 0.4 0.2 1.5 0.2 7D-2 % by mass Polymer (7E) containing Maleic anhydride-modified % by mass 1.0 1.0 1.0 1.0 1.0 1.0 α,β-unsaturated polyphenylene ether dicarboxylic acid anhydride unit Filler (7F) GF % by mass 55.0 55.0 55.0 55.0 55.0 55.0 Total % by mass 100.0 100.0 100.0 100.0 100.0 100.0 PA properties in PA UVA (7D)/halogen content 0.19 0.02 0.20 0.10 0.19 0.02 composition tan δ peak temperature ° C. 109 109 120 120 96 96 Mw g/mol 36,100 36,100 41,000 41,000 26,300 26,300 Mw(7A) − Mw(7B) g/mol 13,000 13,000 — — −1,000 −1,000 Mn 500 to 2000 % 1.4 1.4 1.5 1.5 1.6 1.6 Mw/Mn 2.4 2.4 2.2 2.2 2.2 2.2 [NH.sub.2]/([NH.sub.2] + [COOH]) 0.45 0.45 0.45 0.45 0.45 0.45 Properties of PA moldability A A A B B B composition MD during molding A A A A B B external appearance B C B B A A weathering discoloration 38.0 50.0 35.0 40.0 38.0 80.0 resistance (ΔE) flame retardancy UL94 V-0 V-0 V-0 V-0 V-0 V-0 (1.6 mm) tensile strength MPa 228 225 188 186 183 180 flexural modulus GPa 19.0 19.0 19.0 18.9 18.4 18.4

(695) Tables 7-1 to 7-3 revealed that molded articles obtained from the polyamide compositions 7-1 to 7-14 (Examples 7-1 to 7-14), which contained the aliphatic polyamide (7A) and the semi-aromatic polyamide (7B), wherein the mass ratio of the ultraviolet absorber (7D) relative to the halogen element {(7D)/halogen element} is greater than 0.10 but less than 0.75 [0.10<{(7D)/halogen element}<0.75], had excellent properties, including no noticeable MD during molding, and superior external appearance, tensile strength, flexural modulus and weathering discoloration resistance.

(696) In contrast, molded articles obtained from the polyamide composition 7-15 (Comparative Example 7-1), which did not contain the semi-aromatic polyamide (7B), exhibited unsatisfactory external appearance and flexural modulus.

(697) Further, molded articles obtained from polyamide compositions 7-16 and 7-17 (Comparative Examples 7-2 and 7-3), which although containing the semi-aromatic polyamide (7B), did not contain the aliphatic polyamide (7A), exhibited unsatisfactory results for at least one of the degree of MD during molding, the weathering discoloration resistance, the tensile strength and the flexural modulus.

(698) Furthermore, molded articles obtained from polyamide compositions 7-18 to 7-22 (Comparative Examples 7-4 to 7-8), which although containing the semi-aromatic polyamide (7B), had a mass ratio of the ultraviolet absorber (7D) relative to the halogen element {(7D)/halogen element} that was 0.10 or less [{(7D)/halogen element}≤0.10] or 0.75 or greater [0.75≤{(7D)/halogen element)}], exhibited unsatisfactory results for at least one of the degree of MD during molding, the external appearance, the weathering discoloration resistance, the tensile strength and the flexural modulus.

(699) Further, based on a comparison of the molded articles obtained from the polyamide compositions 7-1, 7-2, and 7-4 to 7-9 (Examples 7-1, 7-2, and 7-4 to 7-9), it was evident that large values for the mass ratio of the ultraviolet absorber (7D) relative to the halogen element {(7D)/halogen element} tended to yield more superior weathering discoloration resistance.

(700) The above results confirmed that by using a polyamide composition of the aspect described above, a molded article having favorable tensile strength, flexural modulus, surface appearance, MD during molding and weathering discoloration resistance could be obtained.