Blow-moldable polyamide compositions

Abstract

Thermoplastic molding compositions comprising A) from 10 to 99.7% by weight of a polyamide, B) from 1 to 30% by weight of an impact modifier, C) from 0.1 to 10% by weight of a copolymer of C.sub.1) from 50 to 95% by weight of styrene or substituted styrenes of the general formula I or a mixture of these ##STR00001## in which R is an alkyl radical having from 1 to 8 carbon atoms or a hydrogen atom and R.sup.1 is an alkyl radical having from 1 to 8 carbon atoms and n has the value 0, 1, 2, or 3, and C.sub.2) from 5 to 50% by weight of structural units derived from one or more dicarboxylic anhydrides, D) from 0.001 to 20% by weight of iron powder, E) from 0.05 to 3% by weight of a copper-containing stabilizer, F) from 100 ppm to 5% by weight of a phosphorus-containing, inorganic acid or salts thereof or ester derivatives thereof or a mixture thereof, G) from 0 to 2% by weight of a polyethyleneimine homo- or copolymer, H) from 0 to 60% by weight of further additives, where the total of the percentages by weight of A) to H) is 100%.

Claims

1. A thermoplastic molding composition comprising A) from 10 to 94% by weight of a polyamide, B) from 10 to 25% by weight of an impact modifier selected from the group consisting of a copolymer I of B.sub.1) from 35 to 89.9% by weight of ethylene B.sub.2) from 10 to 60% by weight of 1-octene or 1-butene or propylene or a mixture of these and B.sub.3) from 0.05 to 5% by weight of functional monomers, where the functional monomers are selected from the group consisting of the carboxylic acid groups, carboxylic anhydride groups, carboxylic ester groups, carboxamide groups, carboximide groups, amino groups, hydroxy groups, epoxy groups, urethane groups, oxazoline groups, and mixtures thereof, a copolymer II of B.sub.1) from 50 to 98% by weight of ethylene B.sub.4) from 2 to 50% by weight of acrylic acid or methacrylic acid, and B.sub.5) optionally from 0 to 20% by weight of functional monomers selected from the group consisting of carboxylic anhydride groups, epoxy groups, and mixtures thereof, or a mixture of copolymer I and copolymer II, C) from 0.1 to 10% by weight of a copolymer of C.sub.1) from 50 to 95% by weight of styrene or substituted styrenes of the general formula I or a mixture of these ##STR00010## in which R is an alkyl radical having from 1 to 8 carbon atoms or a hydrogen atom and R.sup.1 is an alkyl radical having from 1 to 8 carbon atoms and n has the value 0, 1, 2, or 3, and C.sub.2) from 5 to 50% by weight of structural units derived from one or more dicarboxylic anhydrides, D) from 0.001 to 20% by weight of iron powder wherein the C content of component D) is from 0.01 to 1.2 g/100 g when measured by a method based on ASTM E1019, E) from 0.05 to 3% by weight of a copper-containing stabilizer, F) from 100 ppm to 5% by weight of alkali metal salts or alkaline earth metal salts of oxo acids of phosphorus or a mixture of these, G) from 0 to 2% by weight of a polyethyleneimine homo- or copolymer, H) from 0 to 60% by weight of further additives selected from the group consisting of a fibrous filler, a particulate filler, a lubricant, a nigrosin, oxidation retarders, UV stabilizers, dyes, pigments, nucleating agents, heat stabilizers, flame retardants, mold release agents, and plasticizers, wherein: the total of the percentages by weight of A) to H) is 100%, the molding composition exhibits a surface roughness of class 3 or class 4, the molding composition is free of free of copolymers comprising ethylene and (meth)acrylate co-monomers, and the molding composition is free of a sterically hindered phenol.

2. The thermoplastic molding composition according to claim 1, comprising A) from 20 to 94% by weight B) from 10 to 25% by weight C) from 0.1 to 10% by weight D) from 0.001 to 20% by weight E) from 0.05 to 3% by weight F) from 100 ppm to 5% by weight G) from 0.01 to 2% by weight H) from 0 to 50% by weight where the total of the percentages by weight of A) to H) is 100%.

3. The thermoplastic molding composition according to claim 1, comprising, as component C), a copolymer of styrene (C.sub.1) and maleic anhydride (C.sub.2).

4. The thermoplastic molding composition according to claim 1, comprising, as component C), a copolymer with a ratio of from 1:1 to 8:1 between the units C.sub.1: C.sub.2.

5. The thermoplastic molding composition according to claim 1, where the molar mass (M.sub.w) of component C) is from 5000 to 25 000 g/mol.

6. The thermoplastic molding composition according to claim 1, wherein component B) is copolymer I or a mixture of copolymer I and copolymer II.

7. The thermoplastic molding composition according to claim 1, wherein component B) is copolymer II or a mixture of copolymer I and copolymer II, and copolymer II comprises an ethylene-(meth)acrylic acid copolymer which has been neutralized to an extent of up to 72% with zinc.

8. A molding comprising a thermoplastic molding compositions according to claim 1.

9. The molding of claim 8, wherein the molding is a blow molding.

10. The thermoplastic molding composition according to claim 1, where component F) comprises Na hypophosphite.

11. The thermoplastic molding composition according to claim 3, comprising, as component C), a copolymer with a ratio of from 1:1 to 8:1 between the units C.sub.1: C.sub.2.

12. The thermoplastic molding composition according to claim 11, where the molar mass (M.sub.w) of component C) is from 5000 to 25 000 g/mol.

13. The thermoplastic molding composition according to claim 3, where component F) comprises Na hypophosphite.

14. The thermoplastic molding composition according to claim 3, wherein component B) is copolymer I or a mixture of copolymer I and copolymer II.

15. The thermoplastic molding composition according to claim 3, wherein component B) is copolymer II or a mixture of copolymer I and copolymer II, and copolymer II comprises an ethylene-(meth)acrylic acid copolymer which has been neutralized to an extent of up to 72% with zinc.

16. A thermoplastic molding composition comprising A) from 10 to 94% by weight of a polyamide, B) from 1 to 30% by weight of an impact modifier selected from the group consisting of a copolymer I of B.sub.1) from 35 to 89.9% by weight of ethylene B.sub.2) from 10 to 60% by weight of 1-octene or 1-butene or propylene or a mixture of these and B.sub.3) from 0.05 to 5% by weight of functional monomers, where the functional monomers are selected from the group consisting of the carboxylic acid groups, carboxylic anhydride groups, carboxylic ester groups, carboxamide groups, carboximide groups, amino groups, hydroxy groups, epoxy groups, urethane groups, oxazoline groups, and mixtures thereof, a copolymer II of B.sub.1) from 50 to 98% by weight of ethylene B.sub.4) from 2 to 50% by weight of acrylic acid or methacrylic acid, and B.sub.5) optionally from 0 to 20% by weight of functional monomers selected from the group consisting of carboxylic anhydride groups, epoxy groups, and mixtures thereof, or a mixture of copolymer I and copolymer II, C) from 0.1 to 10% by weight of a copolymer of C.sub.1) from 50 to 95% by weight of styrene or substituted styrenes of the general formula I or a mixture of these ##STR00011## in which R is an alkyl radical having from 1 to 8 carbon atoms or a hydrogen atom and R.sup.1 is an alkyl radical having from 1 to 8 carbon atoms and n has the value 0, 1, 2, or 3, and C.sub.2) from 5 to 50% by weight of structural units derived from one or more dicarboxylic anhydrides, D) from 0.001 to 20% by weight of iron powder wherein the C content of component D) is from 0.01 to 1.2 g/100 g when measured by a method based on ASTM E1019, E) from 1 to 3% by weight of a copper-containing stabilizer, F) from 100 ppm to 5% by weight of alkali metal salts or alkaline earth metal salts of oxo acids of phosphorus or a mixture of these, G) from 0 to 2% by weight of a polyethyleneimine homo- or copolymer, H) from 0 to 60% by weight of further additives selected from the group consisting of a fibrous filler, a particulate filler, a lubricant, a nigrosin, oxidation retarders, UV stabilizers, dyes, pigments, nucleating agents, heat stabilizers, flame retardants, mold release agents, and plasticizers, wherein: the total of the percentages by weight of A) to H) is 100%, the molding composition exhibits a surface roughness of class 3 or class 4, the molding composition is free of free of copolymers comprising ethylene and (meth)acrylate co-monomers, and the molding composition is free of a sterically hindered phenol.

17. A thermoplastic molding composition comprising A) from 10 to 94% by weight of a polyamide, B) from 10 to 25% by weight of an impact modifier selected from the group consisting of a copolymer I of B.sub.1) from 35 to 89.9% by weight of ethylene B.sub.2) from 10 to 60% by weight of 1-octene or 1-butene or propylene or a mixture of these and B.sub.3) from 0.05 to 5% by weight of functional monomers, where the functional monomers are selected from the group consisting of the carboxylic acid groups, carboxylic anhydride groups, carboxylic ester groups, carboxamide groups, carboximide groups, amino groups, hydroxy groups, epoxy groups, urethane groups, oxazoline groups, and mixtures thereof, a copolymer II of B.sub.1) from 50 to 98% by weight of ethylene B.sub.4) from 2 to 50% by weight of acrylic acid or methacrylic acid, and B.sub.5) optionally from 0 to 20% by weight of functional monomers selected from the group consisting of carboxylic anhydride groups, epoxy groups, and mixtures thereof, or a mixture of copolymer I and copolymer II, C) from 0.1 to 10% by weight of a copolymer of C.sub.1) from 50 to 95% by weight of styrene or substituted styrenes of the general formula I or a mixture of these ##STR00012## in which R is an alkyl radical having from 1 to 8 carbon atoms or a hydrogen atom and R.sup.1 is an alkyl radical having from 1 to 8 carbon atoms and n has the value 0, 1, 2, or 3, and C.sub.2) from 5 to 50% by weight of structural units derived from one or more dicarboxylic anhydrides, D) from 0.001 to 20% by weight of iron powder wherein the C content of component D) is from 0.01 to 1.2 g/100 g when measured by a method based on ASTM E1019, E) from 1 to 3% by weight of a copper-containing stabilizer, F) from 100 ppm to 5% by weight of alkali metal salts or alkaline earth metal salts of oxo acids of phosphorus or a mixture of these, G) from 0 to 2% by weight of a polyethyleneimine homo- or copolymer, H) from 0 to 60% by weight of further additives selected from the group consisting of a fibrous filler, a particulate filler, a lubricant, a nigrosin, oxidation retarders, UV stabilizers, dyes, pigments, nucleating agents, heat stabilizers, flame retardants, mold release agents, and plasticizers, wherein: the total of the percentages by weight of A) to H) is 100%, the molding composition exhibits a surface roughness of class 3 or class 4, the molding composition is free of free of copolymers comprising ethylene and (meth)acrylate co-monomers, and the molding composition is free of a sterically hindered phenol.

18. The thermoplastic molding composition according to claim 1, wherein the iron powder as component D) has a d.sub.50 in a range from 1.6 m to 8 m.

19. The thermoplastic molding composition according to claim 1, wherein the thermoplastic molding composition consists of components A) to H).

Description

EXAMPLES

(1) The following components were used:

(2) Component A/1

(3) Nylon-6,6 with intrinsic viscosity IV 205 ml/g, measured on a 0.5% by weight solution in 96% by weight sulfuric acid at 25 C. in accordance with ISO 307. (Ultramid A34 from BASF SE was used.)

(4) Component A/2

(5) PA 6 with IV 250 ml/g (Ultramid B40 from BASF SE).

(6) Component B)

(7) Ethylene-methacrylic acid copolymer (90/10), neutralized to an extent of about 70% with zinc (Surlyn 9520 from DuPont)

(8) Component C)

(9) Styrene-maleic anhydride copolymer (3:1) (SMA 3000P from Cray Valley)

(10) M.sub.w=9500 g/mol

(11) M.sub.n=3800 g/mol

(12) Component D)

(13) Iron powder CAS No. 7439-89-6 (see page 11) of description for determination of Fe, C, N, and O content used in the form of 25% masterbatch in PA 66.

(14) TABLE-US-00004 Fe g/100 g at least 97.7 IR detection C g/100 g at most 1.0 IRS N g/100 g at most 1.0 TCD O g/100 g at most 0.6 IRS

(15) Particle size distribution: (laser scattering using Beckmann LS13320)

(16) TABLE-US-00005 d.sub.10 1.4 to 2.7 m d.sub.50 2.9 to 4.2 m d.sub.90 6.4 to 9.2 m

(17) BET surface area 0.44 m.sup.2/g (DIN ISO 9277)

(18) Component E)

(19) CuI/KI in a ratio of 1:4 (20% masterbatch in PA 6)

(20) Component F)

(21) NaH.sub.2PO.sub.21 H.sub.2O

(22) Component G)

(23) TABLE-US-00006 Lupasol WF M.sub.W 25 000 Prim./sec./tert. amines 1/1.2/0.76

(24) Lupasol=registered trademark of BASF SE

(25) .sup.13C NMR spectroscopy was used to determine the primary/secondary/tertiary amines ratio.

(26) Component H/1

(27) Glass fibers (chopped glass fiber with thickness about 10 m).

(28) Component H/2

(29) Nigrosin (40% in PA 6)

(30) The molding compositions (predrying to <0.05%) were produced in a (ZSK) MC26 with throughput 10 kg/h and flat temperature profile at about 280 C. Rotation rate 300 rpm Die diameter 4 mm

(31) The following measurements were made:

(32) Roughness measurement Rz

(33) Rz is what is known as maximum roughness profile height in accordance with DIN EN ISO 4287

(34) Rz is determined as arithmetic average from the maximum profile heights from 5 individual measurements.

(35) The sampling lengths for the individual measurements Ir are 2.5 mm, the cutoff wavelength c=2.5 mm, the traversed length It is 15 mm and the total measured length In=12.5 mm. The traverse speed vt is 0.5 mm/s. The TK300 sensor (Hommelwerke) is used, the sensor tip radius r.sub.SP max is 5 m, and the digitization spacing x.sub.max is 1.5 m.

(36) Class 4: <30 m

(37) Class 3: 30-50 m

(38) Class 2: 50-70 m

(39) Class 1: >70 m

(40) Sagging testStability of parison.

(41) Vertical extrusion of a tube by means of a capillary rheometer and monitoring of length change and of tube diameter under its own weight after extrusion has stopped

(42) An annular die was used for this purpose (dimensions: length L within cylindrical gap 10 mm, internal diameter 8 mm, external diameter 9 mm) in conjunction with a capillary rheometer from Gttfert.

(43) Experimental parameters:

(44) Gttfert Rheograph 2003 capillary rheometer

(45) Temperature: 275 C.

(46) Melting time in rheometer: 5 min

(47) Reservoir diameter: 12 mm

(48) Ram advance speed: 20 mm/s

(49) Extrusion time: 5 s

(50) Procedure:

(51) 30 g of polymer were charged at 275 C. to the Gttfert Rheograph 2003.

(52) The specimen was compressed with the aid of the ram after melting.

(53) The ram was moved downward until the scale indicator was at 17.2 cm.

(54) The die outlet was then cleaned and the ram was moved downward to 17 cm.

(55) An extruded strand of length about 1 cm formed underneath the die here, and was not removed.

(56) After the melting time of 5 minutes, the machine initiated the ram advance at 20 mm/s for 5 seconds. The strand discharged from the die was filmed with a video camera.

(57) In order to identify the stopping of the ram in the film, a laser pointer was projected (manually) into the film for the duration of the extrusion process. By virtue of a scale with specimen identification behind the strand, it was possible through subsequent inspection of the film to evaluate the strand length at the moment at which the ram stopped.

(58) As soon as sagging of the strand ceased, the film was stopped and the test was terminated. The resultant tube was removed after cooling.

(59) The weight, length, and diameter of the specimen strand were determined.

(60) For the diameter, a caliber gage is used to measure the maximum diameter about 2 cm below the bead on the specimen.

(61) Evaluation:

(62) The resistance of the parison to deformation was quantified via calculation of the sagging ratio SR. SR involves calculating a ratio of the lengths of the extruded tube once ram advance has ended after 5 s of extrusion time (L1) to the length of the tube after complete cooling (L2):

(63) $\mathrm{SR}=\left(\frac{L2}{L1}-1\right)\mathrm{100}\%$

(64) Visual assessment of blow molding performance

(65) Criteria: 1. Sagging of the parison (axial differences in wall thickness over entire component length). 2. Swelling on exit from die (where swelling determines the average wall thicknessfor a given die gapin the component). 3. Surface quality, internal and external. 4. Welding of weld lines downstream of spider

(66) Classification: 1 (defective) to 5 (very good)

(67) Mechanical properties:

(68) The tensile test was carried out in accordance with ISO 527-2 prior to and after heat-aging at 200 C. for 500 and 1000 hours, and also at 220 C. for 500 and 1000 hours.

(69) The table will show the constitiutions of the molding compositions and the results of the tests.

(70) TABLE-US-00007 TABLE 1 Components [% by wt.] Examples A/1 B C D E G H/1 F A/2 H/2 Comparative 64 20 1 15 example 1 Comparative 69.25 4 1.5 0.25 15 10 example 2 Comparative 48.25 20 1 4 1.5 0.25 15 10 example 3 Inventive 48.4 20 1 4 1.5 15 0.1 10 example 1 Inventive 46.5 20 1 4 1.5 15 0.1 10 1.9 example 2 Inventive 48.15 20 1 4 1.5 0.25 15 0.1 10 example 3 Inventive 46.25 20 1 4 1.5 0.25 15 0.1 10 1.9 example 4

(71) TABLE-US-00008 TABLE 2 Tensile test Tensile test after heat-aging Blow- prior to heat-aging at 200 C. for 500 h molding Tensile Modulus Tensile Modulus Sagging Surface perform- Yield strain at of Yield strain at of ratio roughness ance stress break elasticity stress break elasticity SR [%] RZ [class] [class] [MPa] [%] [MPa] [MPa] [%] [MPa] Comparative 3.6 2 4 193.64 6.0 4814 100.33 3.42 5180 example 1 Comparative >100 4 1 128.17 3.01 5944 98.8 1.7 6405 example 2 Comparative >100 3 1 107.79 7.5 4695 107.17 8.79 4854 example 3 Inventive 9.3 3 5 99.65 9.04 4895 107.67 8.88 4994 example 1 Inventive 10.6 3 5 96.61 6.91 4870 112.95 7.2 5092 example 2 Inventive 7.4 4 4 9915 9.37 4914 107.4 9.24 4953 example 3 Inventive 16.7 4 4 n.d. n.d. n.d. n.d. n.d. n.d. example 4

(72) TABLE-US-00009 TABLE 3 Tensile test after heat-aging Tensile test after heat-aging Tensile test after heat-aging at 200 C. for 1000 h at 220 C. for 500 h at 220 C. for 1000 h Tensile Modulus Tensile Modulus Tensile Modulus Yield strain at of Yield strain at of Yield strain at of stress break elasticity stress break elasticity stress break elasticity [MPa] [%] [MPa] [MPa] [%] [MPa] [MPa] [%] [MPa] Comparative 67.19 1.6 5194 68.08 1.84 5036 45.37 1.33 4971 example 1 Comparative 103.29 1.83 6362 99.66 1.68 6565 95.22 1.56 6684 example 2 Comparative 103.17 7.25 4740 98.73 4.72 4889 105.59 4.42 4806 example 3 Inventive 103.66 8.76 4858 99.85 8.7 4980 92.92 8.16 4849 example 1 Inventive 108.2 7.04 5027 102.29 7.87 5069 96.6 4.5 4992 example 2 Inventive 104.62 8.03 4846 100.68 7.81 4957 102.09 6.57 5017 example 3 Inventive n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. example 4