ANTISTATIC AND LIGHT-STABLE THERMOPLASTIC POLYCARBONATE MOULDING COMPOUNDS

Abstract

The invention relates to compositions comprising A) 50% to 90% by weight of at least one polymer selected from the group consisting of aromatic polycarbonate, aromatic polyestercarbonate and aromatic polyester, B) 5% to 40% by weight of polymer containing B.1 at least one rubber-modified vinyl (co)polymer containing B.1.1 80% to 95% by weight, based on B.1, of at least one vinyl monomer and B.1.2 5% to 20% by weight, based on B.1, of one or more elastomeric polybutadiene-containing graft bases, where B.1 contains polybutadiene-containing rubber particles which have been grafted with the vinyl monomers B.1.1 and contain inclusions of vinyl (co)polymer consisting of the vinyl monomers B.1.1, and a vinyl (co)polymer matrix consisting of the vinyl monomers B.1.1 which is not bound to these rubber particles and is not included in rubber particles, and optionally B.2 further rubber particles grafted with vinyl monomers and composed of B.2.1 5% to 75% by weight, based on B.2, of at least one vinyl monomer and B.2.2 25% to 95% by weight, based on B.2, of one or more elastomeric graft bases, C) 3% to 25% by weight of a mixture comprising a) at least one polyether-based polymer or copolymer selected from the group consisting of polyether block polymers and polyether-based polyurethanes and b) at least one boron-containing salt, D) 0% to 2% by weight of at least one UV stabilizer selected from the group consisting of the substance classes of the benzotriazoles and triazines, E) 0% to 20% by weight of one or more further additives,
wherein the compositions comprising components A) to E) have a polybutadiene content of 1% to 5% by weight,
and to the use of the compositions for the production of moulded articles, and to the moulded articles themselves.

Claims

1.-15. (canceled)

16. Compositions comprising A) 50% to 90% by weight of at least one polymer selected from the group consisting of aromatic polycarbonate, aromatic polyestercarbonate and aromatic polyester, B) 5% to 40% by weight of polymer containing B.1 at least one rubber-modified vinyl (co)polymer containing B.1.1 80% to 95% by weight, based on B.1, of at least one vinyl monomer and B.1.2 5% to 20% by weight, based on B.1, of one or more elastomeric polybutadiene-containing graft bases, where B.1 contains polybutadiene-containing rubber particles which have been grafted with the vinyl monomers B.1.1 and contain inclusions of vinyl (co)polymer consisting of the vinyl monomers B.1.1, and a vinyl (co)polymer matrix consisting of the vinyl monomers B.1.1 which is not bound to these rubber particles and is not included in rubber particles, and optionally B.2 further rubber particles grafted with vinyl monomers and composed of B.2.1 5% to 75% by weight, based on B.2, of at least one vinyl monomer and B.2.2 25% to 95% by weight, based on B.2, of one or more elastomeric graft bases, C) 3% to 25% by weight of a mixture comprising a) at least one polyether-based polymer or copolymer selected from the group consisting of polyether block polymers and polyether-based polyurethanes and b) at least one boron-containing salt, D) 0% to 2% by weight of at least one UV stabilizer selected from the group consisting of the substance classes of the benzotriazoles and triazines, E) 0% to 20% by weight of one or more further additives, wherein the compositions comprising components A) to E) have a polybutadiene content of 1% to 5% by weight.

17. Compositions according to claim 16, wherein component A is aromatic polycarbonate.

18. Compositions according to claim 16, wherein component B.1 is produced in bulk polymerization methods and the rubber particles containing vinyl (co)polymer inclusions in component B.1 have a median particle diameter D50 of 0.5 to 1.5 m.

19. Compositions according to claim 16, wherein component B.1 has a polybutadiene content of 8% to 13% by weight.

20. Compositions according to claim 16, wherein the vinyl (co)polymer of component B that is not bound to rubber particles and not included in rubber particles has a weight-average molecular weight of 140 to 200 kg/mol.

21. Compositions according to claim 16, wherein component B.2 has been produced in emulsion polymerization by grafting of B.2.1 25% to 50% by weight, based on the graft polymer B.2, of at least one vinyl monomer and B.2.2 50% to 75% by weight, based on the graft polymer B.2, of one or more elastomeric graft bases with glass transition temperatures of <-70 C. and with median particle sizes D50 of 0.2 to 0.4 m.

22. Compositions according to claim 16, wherein the compositions are free of polyacrylate rubbers and silicone rubbers and of graft polymers that contain such rubbers as graft base.

23. Compositions according to claim 16, wherein component B consists of component B.1 to an extent of at least 70% by weight.

24. Compositions according to claim 16, wherein the polyether-based polymer from component C) is a polyether-amide block copolymer consisting of 30% to 70% by weight, based on the block copolymer, of polyethylene glycol blocks and to an extent of 30% to 70% by weight, based on the block copolymer, of polyamide.

25. Compositions according to claim 16, wherein the boron-containing salt in component C is at least one alkali metal salt of a boron-centred anionic complex containing bidentate ligands selected from the group consisting of C2-C8 aliphatic or aromatic components having at least two reactive groups selected from COOH and OH.

26. Compositions according to claim 24, wherein the boron-containing salt is potassium bis(oxalato)borate or sodium bis(oxalato)borate.

27. Compositions according to claim 16, wherein component C consists of 69.6% to 98.6% by weight of polyether block polymer consisting to an extent of 30% to 70% by weight, based on the polyether block polymer, of polyethylene glycol blocks and to an extent of 70% to 30% by weight, based on the polyether block polymer, of nylon-12 blocks, 1% to 30% by weight of at least one further polymer selected from the group consisting of poly(meth)acrylates and polymethyl(meth)acrylates and 0.4% to 4.0% by weight of at least one representative selected from the group consisting of potassium bis(oxalato)borate and sodium bis(oxalato)borate.

28. Compositions according to claim 16, wherein component D is selected from the group consisting of the substance classes of the dimeric benzotriazoles and the 1,3,5-triazines.

29. Use of compositions according to claim 16 for production of moulded articles.

30. Moulded articles obtainable from compositions according to claim 16.

Description

EXAMPLES

Component A

[0227] Linear polycarbonate based on bisphenol A with weight-average molecular weight M.sub.w of 30 000 g/mol (determined by GPC in methylene chloride against a BPA-PC standard).

Component B1

[0228] Acrylonitrile-butadiene-styrene (ABS) polymer prepared by the bulk polymerization process, comprising a disperse phase of polybutadiene-containing rubber particles with inclusions of styrene-acrylonitrile copolymer and a styrene-acrylonitrile-copolymer matrix and having an A:B:S ratio of 23:10:67% by weight and a gel content, determined as the acetone-insoluble fraction, of 20% by weight. The free, i.e. acetone-soluble, styrene-acrylonitrile copolymer in component B1 has a weight average molecular weight M.sub.w (measured by GPC in acetone as solvent with polystyrene standard) of 165 kg/mol. The median rubber particle size D50, measured by ultracentrifugation, is 0.85 m. The melt volume flow rates (MVR) of component B1, measured according to ISO 1133 (2012 version) at 220 C. with a ram load of 1.0 kg, is 6.7 ml/10 min.

Component B2

[0229] ABS blend composed of 20% by weight of an acrylonitrile-butadiene-styrene (ABS) graft polymer prepared by the emulsion polymerization process, with an A:B:S ratio of 14:50:36% by weight and 80% by weight of a styrene-acrylonitrile copolymer with an acrylonitrile:styrene ratio of 25:75% by weight and a weight-average molecular weight M.sub.w (measured by GPC in acetone as solvent with polystyrene as standard) of 110 kg/mol. The mixture thus has an A:B:S ratio of 23:10:67% by weight. The median rubber particle size D50, measured by ultracentrifugation, is 0.32 m. The rubber particles do not contain any inclusions.

Component B3

[0230] ASA blend composed of 37% by weight of a graft polymer having a polybutylacrylate rubber core and a polymethylmethacrylate shell, where the graft polymer has a core/shell ratio of 70:30% by weight, prepared by the emulsion polymerization process, and 63% by weight of a styrene-acrylonitrile copolymer with an acrylonitrile:styrene ratio of 24:76% by weight, The mixture thus has a butyl acrylate rubber content of 26% by weight.

Component C1

[0231] Mixture comprising 15% by weight of polymethylmethacrylate, 83.5% of a polyetheramide block polymer (PEBA) consisting to an extent of 50% by weight, based on the PEBA, of polyethylene glycol blocks and to an extent of 50% by weight, based on the PEBA, of nylon-12 blocks, and 1.5% by weight of potassium bis(oxalato)borate. C1 has a specific surface resistance (measured according to IEC 60093 in the 1993 version) of 8.Math.10.sup.7.

Component C2

[0232] Polyetheramide block copolymer (PEBA) consisting to an extent of 50% by weight, based on the PEBA, of polyethylene glycol blocks and to an extent of 50% by weight, based on the PEBA, of nylon-12 blocks. This is the polyetheramide block copolymer used in accordance with the invention as component C in WO 2012/084848 A1, C2 has a specific surface resistance (measured according to IEC 60093 in the 1993 version) of 3.Math.10.sup.9.

Component D1

[0233] Tinuvin 360 (BASF, Ludwigshafen, Germany):

[0234] 2,2-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol]

Component D2

[0235] Tinuvin 1600 (BASF, Ludwigshafen, Germany):

##STR00008##

Component D3

[0236] Tinuvin 329 (BASF, Ludwigshafen, Germany):

[0237] 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol

Component E1

[0238] Titanium dioxide pigment: Kronos 2233 (Kronos Titan GmbH, Leverkusen, Germany)

Component E2

[0239] Rutile pigment: Heucodur Yellow 3R (Heubach GmbH, Langelsheim, Germany)

Component E3

[0240] Iron oxide pigment: Bayferrox 180M (Lanxess AG, Cologne, Germany)

Component E4

[0241] Carbon black: Elftex 570 Pearls (Cabot GmbH, Rheinfelden, Germany)

Component E5

[0242] pentaerythritol tetrastearate

Component E6

[0243] Irgafos 168 (BASF; Ludwigshafen, Germany)

[0244] tris(2,4-di-tert-butylphenyl) phosphite

Component E7

[0245] Irganox 1076 (BASF; Ludwigshafen, Germany):

[0246] 2,6-di-tert-butyl-4-(octadecanoxycarbonylethyl)phenol

[0247] Production and Testing of the Moudling Compositions According to the Invention

[0248] The components were mixed in a Werner & Pfleiderer ZSK-25 twin-screw extruder at a melt temperature of 260 C. and with application of a reduced pressure of 50 mbar (absolute). With the exception of the test specimens for the puncture test, the moulded articles were produced at a melt temperature of 260 C. and a mould temperature of 80 C. in an Arburg 270E injection moulding machine. The test specimens for the puncture test were produced at a melt temperature of 300 C. with otherwise identical processing parameters.

[0249] The melt volume flow rate (MVR) was determined according to LSO 1133 (2012 version) at 280 C. with a rain load of 5 kg after a dwell time of 5 minutes.

[0250] A measure used for the thermal processing stability of the composition was the relative change in the MVR (deltaMVR) measured according to ISO 1133 (2012 version) at 280 C. with a ram load of 5 kg after a dwell time of 15 minutes compared to the dwell time of 5 minutes.

[0251] IZOD notched impact strength was determined at 30 C. according to ISO 180-1A (1982 version) on each of ten test specimens measuring 80 mm10 mm4 mm. Individual notched impact strength values >30 kJ/m.sup.2 were classified as tough fracture behaviour.

[0252] The tough/brittle transition temperature in the IZOD notched impact test was defined as that temperature at which about half the test specimens have tough and about half have brittle fracture behaviour according to the definition above.

[0253] Vicat B/120 as a measure of heat distortion resistance was determined according to ISO 306 (2013 version) on test specimens having dimensions of 80 min10 mm4 mm with a ram load of 50 N and a heating rate of 120C./h.

[0254] A measure used for low-temperature ductility in the impact/crash test, which is of practical relevance, was the behaviour in the multiaxial puncture test. The puncture test was conducted at 30 C. based on ISO 6603-2 (2000 version, based on means that no visual check of the test specimens was conducted) on test specimens of dimensions 60 mm60 mm2 mm. These were fabricated at an elevated melt temperature of 300 C. in order to simulate particularly critical processing conditions. The modes of fracture of a total of ten test specimens were evaluated to determine whether a tough (non-shattering) or brittle (shattering) mode of fracture occurs.

[0255] Specific surface resistance was determined according to 1EC 60093 (1993 version) on round sheets having a diameter of 60 mm and a thickness of 2 mm.

[0256] Light stability was assessed in the heat and light weathering test according to VW standard PV1303 (2001 version). After 3 and after 6 weathering cycles, a greyscale determination was conducted on colour sample plaques of dimensions 60 mm40 mm2 mm relative to the starting state prior to exposure.

TABLE-US-00001 TABLE 1 Compositions and properties thereof Components [parts by weight] 1 2 3 CE4 CE5 CE6 CE7 CE8 A 70 70 70 70 70 70 70 70 B1 23 23 23 23 23 23 B2 23 B3 23 C1 7 7 7 7 7 C2 7 7 10 D1 0.25 D2 0.25 0.25 0.25 D3 0.25 0.25 0.25 E1 4.77 4.77 4.77 4.77 4.77 4.77 4.77 4.77 E2 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 E3 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 E4 0.03 0.03 0.03 0 03 0.03 0.03 0.03 0.03 E5 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 E6 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 E7 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22 Properties Notched impact 55 55 54 57 58 34 15 15 strength (30 C.) [kJ/m.sup.2] % ductile fracture 100 100 100 90 100 100 0 0 behaviour in puncture test (30 C.) Tough/brittle transition 35 35 35 35 35 30 5 +/0 temperature in IZOD notched impact test [ C.] Vicat B/120 [ C.] 129 130 129 128 128 128 128 125 MVR(280 C./5 kg/5 min) 34 34 35 [ml/10 min] MVR(280 C./5 kg/15 min 51 49 58 [ml/10 min] . Delta MVR (5 min .fwdarw. 15 min) 50% 44% 66% [%] Surface resistance [] 7 .Math. 10.sup.11 6 .Math. 10.sup.11 1 .Math. 10.sup.12 6 .Math. 10.sup.12 5 .Math. 10.sup.12 1 .Math. 10.sup.12 4 .Math. 10.sup.11 8 .Math. 10.sup.11 Greyscale after 3 cycles 4 4 4 4 4 4 4 5 Grey scale after 6 cycles 4 5 4 3 3 3 4 4

[0257] The data in Table 1 show that the inventive compositions 1-3, compared to the comparative examples of compositions 4-8, have an improved combination of excellent low-temperature ductility in the notched impact test and the puncture test, dissipative electrical conductivity (i.e. reduced electrical surface resistance) and exposure stability in the heat and light ageing test.

[0258] Furthermore, a comparison of inventive compositions 1 and 2 with the likewise inventive composition 3 shows that the use of UV stabilizers from the group consisting of the substance classes of the dimeric benzotriazoles and the 1,3,5-triazines should lead to further advantages in terms of processing stability, and these specific UV stabilizers should therefore preferably be used with regard to this achievement of an optimized profile of properties.

[0259] Comparative Examples 4 and 5, in which a noninventive antistat according to the prior art is used, have poorer dissipative electrical conductivity and poorer stability to light exposure. if the antistat according to the prior art is used in a higher concentration (Comparative Example 6), the result is an improved dissipative electrical conductivity, but at the cost of low-temperature ductility. However, no improvement in the dissipative electrical conductivity to the level which is achieved with the compositions according to the invention is achieved by such an increase in concentration.

[0260] Comparative Examples 7 and 8 again show that good dissipative electrical conductivity and stability to light exposure can likewise be achieved using the antistat according to the invention with ABS and ASA vinyl copolymers according to the prior art, but this does not result in the combination with high ductility at low temperatures.