Polyamide Composition and the Article Thereof

Abstract

Disclosed herein is a polyamide composition, and an article which is obtained or obtainable from the composition. The article may include a connector socket for Double Data Rate 5 RAM. The polyamide composition disclosed herein shows desirable tensile strength for the article at a thickness of 0.4 mm, good flowability, and high HDT. The composition also exhibits good thermal stability during molding, and approaches UL 94 V-0.

Claims

1. A polyamide composition, comprising as component (A) 30 to 55 wt % of one or more long chain semi-aromatic polyamides, as component (B) 10 to 20 wt % of flame-retardant system, as component (C) 1 to 4.8 wt % of phosphazene and as component (D) 30 to 50 wt % of reinforcing agent, based on a total weight of the polyamide composition, wherein the flame-retardant system comprises (B-1) dialkylphosphinate of formula (I) and/or diphosphinic salt of formula (II) and (B-2) metal salt of phosphorous acid; ##STR00005## R.sub.1 and R.sub.2 are identical or different and are linear or branched C.sub.1-C.sub.6-alkyl; M or N is Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K, a protonated nitrogen base or a mixture thereof; m is an integer of 1 to 4; n is an integer of 1 to 4; R.sub.3 is linear or branched C.sub.1-C.sub.10-alkylene, C.sub.6-C.sub.10-arylene, C.sub.7-C.sub.20-alkylarylene or C.sub.7-C.sub.20-arylalkylene; R.sub.4 and R.sub.5 are identical or different and are linear or branched C.sub.1-C.sub.6-alkyl; q is an integer of 1 to 4; p is an integer of 1 to 4; x is an integer of 1 to 4.

2. The polyamide composition according to claim 1, wherein the one or more long chain semi-aromatic polyamides comprise polyamide (i) and/or polyamide (ii), the polyamide (i) is derived from monomers comprising (A-1) dicarboxylic acids which comprise 60-100 mol % of terephthalic acid based on a total amount of the dicarboxylic acids, (A-2) diamines which comprise as component (a) aliphatic diamine having a carbon number of at least 8 in an amount of 60-100 mol % based on a total amount of the diamines, and optionally (A-3) amino acid and/or lactam; polyamide (ii) is derived from monomers comprising (A-4) dicarboxylic acids which comprise 60-100 mol % of aliphatic dicarboxylic acid having a carbon number of at least 8 based on a total amount of the dicarboxylic acids, (A-5) diamines which comprise 60-100 mol % of aromatic diamine based on a total amount of the diamines, and optionally (A-3) amino acid and/or lactam.

3. The polyamide composition according to claim 1, wherein the aliphatic diamine (a) of polyamide (i) comprises from 8 to 36 carbon atoms; and wherein the aliphatic dicarboxylic acid having the carbon number of at least 8 of polyamide (ii) cmprises from 8 to 36 carbon atoms.

4. The polyamide composition according to claim 1, wherein the one or more long chain semi-aromatic polyamides are selected from the group consisting of PAST, PA10T, PA1 1T, PA12T, PA13T, PA14T PA6T/8T, PA10T/6T, PA10T/610, PA6T/610, PA5T/510and PA4T/410.

5. The polyamide composition according to claim 1, wherein the one or more long chain semi-aromatic polyamides have a viscosity number of 60˜120 ml/g, which is measured in 96 wt % H.sub.2SO.sub.4 according to a method of ISO307-2007.

6. The polyamide composition according to claim 1, wherein the dialkylphosphinate of formula (I) is selected from the group consisting of calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphoshinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate and zinc methyl-n-propylphosphinate; wherein the diphosphinic salt of formula (II) is selected from the group consisting of calcium methanedi(methylphosphinate), magnesium methanedi(methylphosphinate), aluminum methanedi(methylphosphinate), zinc methanedi(methylphosphinate), calcium benzene-1,4-(dimethylphosphinate), magnesium benzene-1,4-(dimethylphosphinate), aluminum benzene-1,4-(dimethylphosphinate) and zinc benzene-1,4-(dimethylphosphinate); and wherein the metal salt of phosphorous acid is selected from the group consisting of Al(H.sub.2PO.sub.3).sub.3, Al.sub.2(HPO.sub.3).sub.3, Zn(HPO.sub.3), Al2(HPO.sub.3).sub.34H.sub.2O and Al(OH)(H.sub.2PO.sub.3).sub.22H.sub.2O.

7. The polyamide composition according to claim 1, wherein the components (B-1) and (B-2) are in a mass ratio of (B-1)/(B-2) from 60:40 to 90:10.

8. The polyamide composition according to claim 1, wherein the phosphazene (C) is at least one phosphazene selected from the group consisting of a cyclic phosphazene having the formula (V), a linear phosphazene having the formula (VI), and at least one phosphazene obtained by cross-linking the cyclic phosphazene or the linear phosphazene with a cross-linking group; ##STR00006## wherein each R.sub.6 is identical or different and is C.sub.1-C.sub.20-alkyl, C.sub.6-C.sub.20-aryl, C.sub.7-C.sub.30-arylalkyl, or C.sub.7-C.sub.30-alkylaryl; u is an integer from 3 to 25; v is an integer of from 3 to 10,000; Z is —N═P(OR.sub.6).sub.3 or —N═P(O)OR.sub.6; S is —P(OR.sub.6).sub.4 or —P(O)(OR.sub.6).sub.2.

9. The polyamide composition according to claim 1, wherein the phosphazene is of the formula (VII): ##STR00007##

10. The polyamide composition according to claim 1, wherein the reinforcing agent (D) is selected from the group consisting of glass fibers, carbon fibers, boron fibers, asbestos fibers, polyvinyl alcohol fibers, polyester fibers, acrylic fibers, wholly aromatic polyamide fibers, polybenzoxazole fibers, polytetrafluoroethylene fibers, kenaf fibers, bamboo fibers, hemp fibers, bagasse fibers, high strength polyethylene fibers, alumina fibers, silicon carbide fibers, potassium titanate fibers, brass fibers, stainless steel fibers, steel fibers, ceramic fibers and basalt fibers; wherein the fiber length is from 2 to 7 mm, and wherein the fiber diameter is from 3 to 20 μm.

11. The polyamide composition according to claim 1, wherein the polyamide composition has a heat distortion temperature of at least 265° C., measured according to method A of ISO 75-1/2.

12. The polyamide composition according to claim 1, wherein the polyamide composition has a tensile stress of higher than 99 MPa, measured using samples having a thickness of 0.4 mm of type 5A according to ISO 527-2.

13. An article obtained by the polyamide composition according to claim 1, wherein the article has a heat distortion temperature of at least 265° C. measured according to method A of ISO 75-1/2 and maximum working frequency of higher than 3.2 GHz.

14. The article according to claim 13, wherein the article is selected from the group consisting of connector sockets, an antenna frame, circuit boards, circuit breakers, coil elements, a frame or a housing or a package of cell phones, sensors and laptops.

15. The article according to claim 14, wherein the connector sockets are sockets for random access memory ora central process unit or solid state memory.

16. Connector sockets obtained by the polyamide composition according to claim 1, wherein the connector sockets are fine pitch electrical connector sockets, comprising at least two opposing walls, and a passageway defined between the opposing walls for receiving an insert with contact pins, wherein the opposing walls and the contact pins are formed from the polyamide composition, and wherein the opposing walls each comprise a terminal portion; wherein a thickness of the terminal portions is lower than 5.9 mm, and wherein the thickness is measured in an inserting direction of the insert; wherein a width of the contact pins is from 0.2 mm to 0.4 mm; and wherein the fine pitch electrical connector sockets are fine pitch electrical connector sockets of random access memory of DDR5.

17. The polyamide composition according to claim 1, wherein the aliphatic diamine (a) of polyamide (i) comprises from 8 to 36 carbon atoms, and is selected from the group consisting of 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, 1,16-hexadecanediamine, 1,18-octadecanediamine, 1,20-eicosanediamine, 1,22-docosanediamine, 2-methyl-1,8-octanediamine, 5-methylnonane-1,9-diamine and 2,4-dimethyloctanediamine; and wherein the aliphatic dicarboxylic acid having the carbon number of at least 8 of polyamide (ii) comprises from 8 to 36 carbon atoms, and is selected from the group consisting of pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanoic acid, hexadecanedioic acid, octadecanedioic acid and C36 dimer acid.

18. The polyamide composition according to claim 1, wherein the phosphazene (C) is at least one phosphazene selected from the group consisting of a cyclic phosphazene having the formula (V), a linear phosphazene having the formula (VI), and at least one phosphazene obtained by cross-linking the cyclic phosphazene or the linear phosphazene with a cross-linking group; ##STR00008## wherein each R.sub.6 is identical or different and is C.sub.1-C.sub.20-alkyl, C.sub.6-C.sub.20-aryl, C.sub.7-C.sub.30-arylalkyl, or C.sub.7-C.sub.30-alkylaryl; u is an integer from 3 to 6; v is an integer of from 3 to 10,000; Z is —N═P(OR.sub.6).sub.3 or —N═P(O)OR.sub.6; S is —P(OR.sub.6).sub.4 or —P(O)(OR.sub.6).sub.2.

19. The polyamide composition according to claim 1, wherein the reinforcing agent (D) is selected from the group consisting of glass fibers, carbon fibers, boron fibers, asbestos fibers, polyvinyl alcohol fibers, polyester fibers, acrylic fibers, wholly aromatic polyamide fibers, polybenzoxazole fibers, polytetrafluoroethylene fibers, kenaf fibers, bamboo fibers, hemp fibers, bagasse fibers, high strength polyethylene fibers, alumina fibers, silicon carbide fibers, potassium titanate fibers, brass fibers, stainless steel fibers, steel fibers, ceramic fibers and basalt fibers; wherein the fiber length is from 2 to 7 mm, and wherein the fiber diameter is from 7 to 13 μm.

20. The polyamide composition according to claim 1, wherein the polyamide composition has a heat distortion temperature of at least 270° C., measured according to method A of ISO 75-1/2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0110] FIG. 1 is an illustration of a wall of a RAM connector socket of the invention.

[0111] FIG. 2 is a graph of reflow process temperature vs reflow process time in blister test.

EXAMPLES

[0112] Hereinafter, the present invention will be detailed with reference to Examples, which however shall not be construed as limiting the scope of the present invention. In examples and comparative examples, measurements and evaluations of physical properties are made as described below.

[0113] (A) PA9T from Kuraray Co., Ltd. (with viscosity number to ISO307,1157,1628 of 79 cm.sup.3/g, number-average molar mass molecular weight (Mn) of 9600 g/mol)

[0114] (B) Exolit OP1400 from Clariant Plastics & Coating Ltd., mixture of about 80 wt % of aluminum salt of diethylphosphinic acid and about 20 wt % of aluminum salt of phosphorous acid;

[0115] (C1) SPB 100 from Otsuka Chemical Co., Ltd., cyclic phenoxyphosphazene having formula (VI).

[0116] (C2) OGSOL MF-11, flow improver from OSAKA GAS Chemicals Co. Ltd.

[0117] (C3) Joncryl® ADD 3310, acid-functional styrene/acrylic polymer from BASF.

[0118] (D) HP 3610 from PPG Industries Inc., glass fiber with diameter of 10 μm and length of 4.5 mm.

[0119] (E-1) Polyad® PB 201 from PolyAd Services GmbH combination of CuI 80 wt %, KI 10 wt % and Zn stearate 10 wt %.

[0120] (E-2) EBS (ethylene bis stearamide) from Croda Trading (Shanghai) Co., ltd.

[0121] (E-3) Carbon black from Orion Engineered Carbons.

Examples 1-5 and Comparative Examples 1-8

[0122] The formulations for the examples and comparative examples 1-6 are shown in the following Table 1. The raw materials are mixed together in a Turbula T50A high-speed stirrer, fed into a Coperion ZSK26MC twin-screw extruder, melt-extruded under a temperature of 320° C., pelletized, thus obtaining a semi-aromatic polyamide composition in a pellet form.

[0123] The dried pellets were processed in an injection molding machine KM130CX, from Krauss Maffei with a clamping force of 130 T at melt temperatures of 300° C. to 330° C. to give test specimens.

[0124] Flow length was measured using a spiral flow tooling with a spiral runner. The cross section of the spiral runner has a thickness of 2 mm and width of 5.5 mm, numbered and subdivided centimeters are marked along the runner. The test material was melted at 320° C., then the melt was injected into the spiral runner under 500 bar pressure and 140° C. The spiral runner was filled from a sprue at the center of the spiral runner, and the pressure and temperature were maintained until the melt stopped, the mark number just at the tip of spiral melt giving the flow length.

[0125] Tensile stress at break and tensile strain at break for samples having thickness of 4 mm were measured according to ISO 527-1-2012. Test specimens of type 1 described in ISO 527-1-2012 were used.

[0126] Tensile stress at break and tensile strain at break for samples having thickness of 0.4 mm were measured according to ISO 527-1-2012. Test specimens having the shape of type 5A described in ISO 527-1-2012 were used. The dimensions of the test specimens are as below: over length I.sub.3=75 mm, length of narrow parallel-sided portion I.sub.1=25 mm, initial distance between grips L=50 mm, gauge length L.sub.0=20 mm, width at narrow portion b.sub.1=4 mm, width at ends b.sub.2=12.5 mm, large radius r.sub.2=12.52 mm, small radius r.sub.1=8 mm, and thickness h=0.4 mm. The definitions of I.sub.1, I.sub.3, L, L.sub.0, b.sub.1, b.sub.2, r.sub.1, r.sub.2and h are the same as in ISO 527-2-2012.

[0127] Charpy notched impact strength and Charpy unnotched impact strength was tested according to ISO 179-1-2010 via edgewise impact.

[0128] The test specimens for Charpy unnotched test is type 1 specimen with the dimensions of 80*10*4 mm (length*width* thickness). The test specimens for Charpy notched test is type 1 with notched type A. All the test specimens were conditioned at 23° C. and 50% relative humidity for 16 h. The tests were conduced under the same atmosphere as conditioning.

[0129] HDT was tested according to method A of ISO 75-2-2013 under 1.8 MPa.

[0130] The UL 94 fire classification were tested using sample sizes of 127 mm*12.7 mm*0.4 mm (length*width*thickness), 127 mm*12.7 mm*0.8 mm, and 127 mm*12.7 mm*1.6 mm.

[0131] Comparative examples 1-2, 7-8 shows that the addition of phosphazene, and commercialized flow improver, the flowability is increased but the mechanical properties of the composition, such as HDT, tensile properties decrease. Phosphazene and acid-functional styrene/acrylic polymer decreases the tensile properties of samples with both 4 mm and 0.4 mm thickness, especially for samples with 0.4 mm thickness. The flame retardancy of C1 and C2 could only approach V-2 for the samples with 0.4 mm thickness. The tensile property of samples having 4 mm thickness is increased by the addition of OGSOL MF-11, however the tensile property for 0.4 mm thickness and HDT are decreased.

[0132] Examples 1-5 and comparative example 2 show that the tensile property for the samples having thickness of 4 mm are maintained within the amount of phosphazene in 1˜4 wt % and drops heavily when the amount of phosphazene is 5 wt %. Meanwhile, the composition exhibits excellent tensile properties in the thickness of 0.4 mm within the phosphazene amount of 1˜4.8 wt %, and the glass fiber amount of 30-50wt %, this could well fulfil the requirement of electronic articles with maximum working frequency of higher than 3.2 GHz.

Examples 6

[0133] Connector sockets shown in FIG. 1 were prepared of polyamide composition of examples 1-5 via injection molding. The connect sockets comprise two opposing walls 1, 2 with length of 142 mm and a passageway defined between the opposing walls 1, 2 for receiving a memory chip or other insert with contact pins, each wall has a terminal portion 3 with thickness T of 5.4 mm. The width of the contact pins is 0.2 mm to 0.4 mm.

[0134] Blister Test During Reflow Process:

[0135] The polyamide compositions of examples 1-5 were injection molded into test pieces (length: 64 mm, width: 6 mm, thickness: 0.4 mm).

[0136] The reflow process was conducted according to IPC/JEDEC J-STD-020D.1 (Joint Industry Standard). The connector sockets were subjected to moisture soak at 85° C. and a relative humidity of 85% for 168 hours. A reflow process was performed in accordance with the temperature profile shown in FIG. 2. Referring to FIG. 2, the test pieces were heated to 217° C. and then heated to 255° C. for 30 s, the peak temperature is 270° C., then cooled back to 217° C., and cooled back to 25° C. (cycle 1). Performing the above reflow process for the other two times, and visual inspecting the blister on the surface of the connector sockets. From the above reflow process the peak temperature was found at which the sockets were not molten, and no blister was observed on the surface. After the 3-cycle reflow process, there is still no blister occurs in the sockets.

[0137] DDR 5 Application Test:

[0138] The connect sockets were tested according to JEDEC DDR5 standard in JEDEC'S JC-42 COMMITTEE. All the connectors passed the application test.

TABLE-US-00001 TABLE 1 Component (wt %) C1 C2 C3 E1 E2 E3 C4 C5 C7 C8 E4 C6 E5 (A) 54.61 54.61 44.61 44.61 45.61 44.61 44.61 46.61 45.61 45.61 46.61 34.61 34.61 (B) 19 17 19 18 17 15 14 17 17 17 15 19 17 (C1) — 2 — 1 2 4 5 — — — 2 — 2 (C2) — — — — — — — — 2 — — — — (C3) — — — — — — — — — 2 — — — (D) 25 25 35 35 35 35 35 35 35 35 35 45 45 (E-1) 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 (E-2) 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 (E-3) 0.67 0.67 0.67 0.67 0.67 0.67 0.67 0.67 0.67 0.67 0.67 0.67 0.67 Flow length 2 m (cm) 61 63 52 58 60 61 63 56 54 58 60 51 53 Tensile stress, 121 119 158 160 159 159 140 156 160 132 153 149 150 thickness = 4.0 mm (MPa) Tensile strain, 2.0 2.0 1.9 1.9 2.0 2.0 1.8 1.9 1.9 1.6 1.8 1.3 1.4 thickness = 4.0 mm (%) Tensile stress, 99 92 95 99 100 103 96 98 94 84 106 93 98 thickness = 0.4 mm (MPa) Tensile strain, 1.8 1.6 1.0 1.2 1.3 1.5 1.2 1.1 1.1 0.9 1.4 0.8 1 thickness = 0.4 mm (%) Charpy notched impact 9 10 15 15 16 14 15 14 14 13 15 15 17 strength (KJ/m.sup.2) Charpy unnotched impact 45 43 57 56 59 60 56 57 52 48 60 41 45 strength (KJ/m.sup.2) HDT method A, T.sub.ff 1.8 270 268 274 272 271 273 268 272 265 268 272 275 271 (° C.) UL94 test at 0.4 mm V-2 V-2 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-2 V-0 V-0 V-0 thickness UL94 test at 0.8 mm V-1 V-2 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 thickness UL94 test at 1.6 mm V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 thickness DDR 5 application not not not pass pass pass not not not not pass not pass “C” stands for comparative examples, “E” stands for example