Polycarbonate composition having pearlescent pigments and / or interference pigments

Abstract

The present invention relates to an aromatic polycarbonate-based composition which contains metal oxide-coated mica as an effect pigment and which, as can be seen from the MVR, shows no significant reduction in the polycarbonate molecular weight under thermal stress. This is achieved by adding a small amount of a copolymer or terpolymer of styrene with acrylic acid and / or methacrylic acid containing epoxy groups in combination with a phosphite-containing heat stabilizer.

Description

[0001] The present invention relates to thermoplastic polycarbonate compositions which comprise interference pigments and / or pearlescent pigments selected from metal oxide-coated mica, and to moldings produced from these compositions.

[0002] In some cases, effect pigments are added to polycarbonate compositions in order to influence the appearance of the composition by changes in the angle-dependent hue and / or gloss. The effect pigments are platelet-shaped and cause specular reflection and / or interference. There are different groups of effect pigments: metallic effect pigments, interference pigments and pearlescent pigments, where the boundaries between them, especially in the case of the latter, may be indistinct, and they are therefore also collectively referred to as "special effect pigments".

[0003] Pearlescent pigments comprise transparent platelets with a high refractive index. A pearl-like effect is produced by multiple reflections. In the case of interference pigments, the coloring can be transparent or opaque, especially based on interference.

[0004] Pearlescent pigments and / or interference pigments in particular also include metal oxide-coated mica pigments, which are used in various fields, for example for the housings of numerous household appliances or consumer electronic devices or as design elements in the building field. Such pearlescent effects and / or interference pigments are available in particular from BASF SE under the name "Magnapearl ® " or "Mearlin ® " or from Merck SE under the name "Iriodin ® " or "Candurin ® ".

[0005] DE2019325A1 discloses colored aromatic polycarbonates which have a content of a mixed polymer containing epoxy groups of from about 5 to about 100% by weight, based on the pigment content.

[0006] WO2016 / 096696A1 describes a thermoplastic molding compound which comprises g) 5 to 99.9% by weight of at least one thermoplastic polymer as component A; h) 0.05 - 10% by weight of at least one mica coated with a metal oxide as component B; i) 0.05 to 50% by weight of at least one flame retardant different from component B as component C; j) 0 to 35% by weight of at least one functional polymer different from component A as component D; k) 0 to 60% by weight of glass fibers as component E, and l) 0 to 10% by weight of other auxiliaries as component F, where the total amount of components A to E is 100% by weight.

[0007] EP0158931A1 relates to a thermoplastic molding compound, which comprises: A) 10 to 80 parts by weight of an aromatic thermoplastic polycarbonate, B) 10 to 60 parts by weight of a graft polymer of an ethylenically unsaturated monomer on a rubber, wherein the rubber content is 5 to 80% by weight, based on the weight of component B), and C) 10 to 60 parts by weight of a thermoplastic, resin-like, high molecular weight, rubber-free copolymer, wherein in each case the sum of the parts by weight of A + B + C is 100, and optionally D) 1 to 20 parts by weight of at least partially crosslinked butadiene-acrylonitrile copolymer rubber, which in each case, based on the sum of the parts by weight of A + B + C + D, is also 100 in each case, which contains acrylonitrile and butadiene incorporated into the polymer (einpolymerisiert) in a weight ratio of 15:85 to 35:65 and has a particle size of 0.05 μm to 0.3 μm. Based on the weight of component C, component C contains 0.05 to 5% by weight of a copolymerized ethylenically unsaturated epoxide.

[0008] EP0718354A2 discloses thermoplastic aromatic polycarbonates having phosphine stabilizers. Examples of phosphines that can be used are tris(4-biphenylyl)phosphine or tris(α-naphthyl)phosphine.

[0009] When used in polycarbonate compositions, pearlescent or interference pigments selected from metal oxide-coated mica usually cause significant degradation of the polycarbonate, which is manifested as a decrease in molecular weight and a related decrease in viscosity, and thus an increase in melt volume flow rate MVR and deterioration of mechanical properties. This degradation process also causes the material to discolor.

[0010] For the compositions in the market, the degradation process is taken into account by using polycarbonates having a higher molecular weight than required for the actual application. Then, the target molecular weight is obtained by a kneading process, an injection molding process or an extrusion process at a high temperature. Other parameters in the mixing process, such as the control of energy input or the arrangement of the metering addition point of the effect pigment, also have an important influence on the molecular weight of the finally produced polycarbonate. However, it has been found that targeted control of the molecular weight is problematic.

[0011] In principle, one possibility to minimize the degradation of polycarbonates is to use heat stabilizers. To thermally stabilize polycarbonates, generally suitable organic phosphorus compounds such as aromatic phosphines, aromatic phosphites and organic antioxidants, especially sterically hindered phenols, are added. The combined use of phosphites and sterically hindered phenols is often described, for example, in EP0426499A1. However, in the case of the said effect pigments, stabilization only by phosphites is not sufficient.

[0012] Accordingly, it is an object to provide polycarbonate compositions which contain pearlescent pigments and / or interference pigments selected from metal oxide-coated mica and which exhibit as little polycarbonate degradation as possible during compounding, thus avoiding the aforementioned disadvantages as much as possible.

[0013] Surprisingly, it has been found that this object is achieved by adding a copolymer or terpolymer containing epoxy groups of styrene with acrylic acid and / or methacrylic acid, which is combined with a phosphite heat stabilizer, to a polycarbonate composition containing pearlescent pigments and / or interference pigments selected from metal oxide-coated mica.

[0014] The thermoplastic compositions according to the invention are thus those which contain the following:

[0015] A) 50% to 98.5% by weight of an aromatic polycarbonate, and

[0016] B) 0.8% to ≤ 5.0% by weight of interference pigments and / or pearlescent pigments selected from metal oxide-coated mica,

[0017] characterized in that the composition further contains

[0018] C) 0.05% to ≤ 3% by weight of a copolymer or terpolymer containing epoxy groups of styrene with acrylic acid and / or methacrylic acid, and

[0019] D) 0.001% to 0.500% by weight of one or more heat stabilizers, where component D includes one or more phosphites as heat stabilizers,

[0020] and preferably such thermoplastic compositions which further contain

[0021] E) other additives, more preferably 0 to 10% by weight, particularly preferably selected from flame retardants, anti-dripping agents, impact modifiers, fillers, antistatic agents, colorants, including pigments different from component B, also including carbon black, lubricants and / or release agents, hydrolysis stabilizers, compatibilizers, UV absorbers and / or IR absorbers.

[0022] Component A

[0023] Component A is an aromatic polycarbonate. According to the invention, "polycarbonate" is understood to mean homopolycarbonates and copolycarbonates. Herein, in a known manner, these polycarbonates can be linear or branched. According to the invention, mixtures of polycarbonates can also be used.

[0024] In the polycarbonates used according to the invention, a part of the carbonate groups, up to 80 mol%, preferably 20 mol% to 50 mol% of the carbonate groups, can be replaced by aromatic dicarboxylate groups. Such polycarbonates incorporating acid esters of carbonic acid and acid esters of aromatic dicarboxylic acids in the molecular chain are called aromatic polyester carbonates. Within the scope of the present invention, they are subsumed under the generic term thermoplastic aromatic polycarbonates.

[0025] The replacement of carbonate groups by aromatic dicarboxylate groups is carried out substantially stoichiometrically and also quantitatively, so that the molar ratios of the reaction participants are also rediscovered in the final polyester carbonate. The introduction of the aromatic dicarboxylate groups can be carried out randomly or in a blockwise manner.

[0026] Thermoplastic polycarbonates, including thermoplastic aromatic polyester carbonates, have an average molecular weight Mw of 10,000 g / mol to 35,000 g / mol, preferably 12,000 g / mol to 32,000 g / mol, more preferably 15,000 g / mol to 32,000 g / mol, especially 20,000 g / mol to 31,500 g / mol. The average molecular weight Mw is determined according to DIN 55672-1:2007-08 by means of gel permeation chromatography, calibrated using dichloromethane as the eluent relative to a bisphenol A-polycarbonate standard, calibrated using linear polycarbonates with known molar mass distributions (formed from bisphenol A and phosgene) from PSS Polymer Standards Service GmbH, Germany, and calibrated according to method 2301-0257502-09D (German version 2009) of Currenta GmbH & Co. OHG, Leverkusen. The eluent is dichloromethane. Column combination of crosslinked styrene-divinylbenzene resins. Diameter of the analytical column: 7.5 mm; length: 300 mm. Particle size of the column material: 3 μm to 20 μm. Concentration of the solution: 0.2 wt%. Flow rate: 1.0 ml / min, temperature of the solution: 30 °C. Detection is carried out by means of a refractive index (RI) detector.

[0027] For more than 40 years, the preparation details of polycarbonates have been described in many patent specifications. Here, for example, reference can be made to Schnell, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964, D. Freitag, U. Grigo, P. R. Müller, H. Nouvertné, BAYER AG, "Polycarbonates" in Encyclopedia of Polymer Science and Engineering, Volume 11, 2nd Edition, 1988, pages 648 - 718, and finally U. Grigo, K. Kirchner and P. R. Müller "Polycarbonate" in Becker / Braun, Kunststoff-Handbuch, Volume 3 / 1, Polycarbonate, Polyacetale, Polyester, Celluloseester, Carl Hanser Verlag Munich, Vienna 1992, pages 117 - 299.

[0028] Preferred processes for preparing the polycarbonates (including polyester carbonates) to be used according to the invention are the known interfacial process and the known melt transesterification process (see, for example, WO 2004 / 063249 A1, WO 2001 / 05866 A1, US 5,340,905 A, US 5,097,002 A, US - A 5,717,057 A).

[0029] The preparation of aromatic polycarbonates is effected, for example, by the phase - interface process, optionally using a chain terminator and optionally using a trifunctional or more than trifunctional branching agent, by reaction of dihydroxyaromatic compounds with carbonyl halides, preferably phosgene, and / or with aromatic dicarbonyl halides, preferably benzene dicarbonyl halides, where, for the preparation of polyester carbonates, a part of the carbonate derivatives, more precisely according to the proportion of carbonate structural units to be replaced by aromatic dicarboxylate structural units in the aromatic polycarbonate, are replaced by aromatic dicarboxylic acids or derivatives of this dicarboxylic acid. It can also be prepared by the melt polymerization process by reaction of dihydroxyaromatic compounds with, for example, diphenyl carbonate.

[0030] The dihydroxyaromatic compounds suitable for the preparation of polycarbonates are those of formula (1)

[0031]

[0032] wherein

[0033] Z is an aromatic group having 6 to 30 carbon atoms, which may contain one or more aromatic rings, may be substituted and may contain an aliphatic or alicyclic group or an alkylaryl or a heteroatom as a bridging member.

[0034] Preferably, Z in formula (1) represents a group of formula (2)

[0035]

[0036] wherein

[0037] R 6 and R 7 each independently represent H, C1 to C 18 alkyl, C1 to C 18 alkoxy, a halogen such as Cl or Br or represent an aryl or aralkyl optionally substituted in each case, preferably represent H or C1 to C 12 alkyl, particularly preferably represent H or C1 to C8 alkyl and very particularly preferably represent H or methyl, and

[0038] X represents a single bond, -SO2-, -CO-, -O-, -S-, C1 to C6 alkylene, C2 to C5 alkylidene or C5 to C6 cycloalkylidene, which may be substituted by C1 to C6, preferably methyl or ethyl, and further represents C6 to C 12 arylene, which may optionally be fused with other aromatic rings containing heteroatoms.

[0039] Preferably, X represents a single bond, C1 to C5 alkylene, C2 to C5 alkylidene, C5 to C6 cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO2-

[0040] or represents a group of formula (2a)

[0041] .

[0042] Dihydroxyaryl compounds suitable for the preparation of polycarbonates are, for example, hydroquinone, resorcinol, dihydroxybiphenyl, bis-(hydroxyphenyl)alkanes, bis-(hydroxyphenyl)cycloalkanes, bis-(hydroxyphenyl)sulfides, bis-(hydroxyphenyl)ethers, bis-(hydroxyphenyl)ketones, bis-(hydroxyphenyl)sulfones, bis-(hydroxyphenyl)sulfoxides, α,α'-bis-(hydroxyphenyl)diisopropylbenzene, benzo c pyrrolidones derived from isatin or phenolphthalein derivatives and their compounds alkylated, arylated and halogenated on the ring.

[0043] Preferred dihydroxyaryl compounds are 4,4'-dihydroxybiphenyl, 2,2-bis-(4-hydroxyphenyl)propane (bisphenol A), 2,4-bis-(4-hydroxyphenyl)-2-methylbutane, 1,1-bis-(4-hydroxyphenyl)-p-diisopropylbenzene, 2,2-bis-(3-methyl-4-hydroxyphenyl)propane, dimethyl-bisphenol A, bis-(3,5-dimethyl-4-hydroxyphenyl)methane, 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)propane, bis-(3,5-dimethyl-4-hydroxyphenyl)sulfone, 2,4-bis-(3,5-dimethyl-4-hydroxyphenyl)-2-methylbutane, 1,1-bis-(3,5-dimethyl-4-hydroxyphenyl)-p-diisopropylbenzene and 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and bisphenols (I) to (III).

[0044]

[0045] wherein R' in each case represents C1 to C4 alkyl, aralkyl or aryl, preferably represents methyl or phenyl, and most preferably represents methyl.

[0046] Particularly preferred dihydroxyaryl compounds are 2,2-bis-(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)propane, 1,1-bis-(4-hydroxyphenyl)cyclohexane, 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and dimethyl-bisphenol A and the diphenols of the formulae (I), (II) and (III).

[0047] These and other suitable dihydroxyaryl compounds are described, for example, in US-A 3 028 635, US-A 2 999 825, US-A 3 148 172, US-A 2 991 273, US-A 3 271 367, US-A 4 982 014 and US-A 2 999 846, in DE-A 1 570 703, DE-A 2 063 050, DE-A 2 036 052, DE-A 2 211 956 and DE-A 3 832 396, in FR-A 1 561 518, in the monograph "H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964" and in JP-A 62 039 / 1986, JP-A 62 040 / 1986 and JP-A 105 550 / 1986.

[0048] In the case of a homopolycarbonate, only one dihydroxyaryl compound is used; in the case of a copolycarbonate, multiple dihydroxyaryl compounds are used. Like all other chemicals and auxiliaries added to the synthesis, the dihydroxyaryl compounds used may be contaminated by impurities from their own synthesis, handling, and storage. However, it is desirable to work with the purest possible raw materials.

[0049] Suitable carbonic acid derivatives are, for example, phosgene or diphenyl carbonate.

[0050] Suitable chain terminators for the preparation of polycarbonates are monophenols. Suitable monophenols are, for example, phenol itself, alkylphenols such as cresols, p-tert-butylphenol, cumylphenol, and mixtures thereof.

[0051] Preferred chain terminators are phenols mono- or polysubstituted by linear or branched, preferably unsubstituted C1 to C 30 alkyl or tert-butyl. Particularly preferred chain terminators are phenol, cumylphenol, and / or p-tert-butylphenol.

[0052] Based on the number of moles of diphenol used in each case, the amount of chain terminator to be used is preferably 0.1 to 5 mol%. The chain terminator can be added before, during, or after the reaction with the carbonic acid derivative.

[0053] Suitable branching agents are trifunctional or more than trifunctional compounds known in polycarbonate chemistry, especially those having three or more phenolic OH groups.

[0054] Suitable branching agents are, for example, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(4-hydroxyphenyl)ethane, tris(4-hydroxyphenyl)phenylmethane, 2,4-bis(4-hydroxyphenylisopropyl)phenol, 2,6-bis(2-hydroxy-5'-methylbenzyl)-4-methylphenol, 2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)propane, tetrakis(4-hydroxyphenyl)methane, tetrakis(4-(4-hydroxyphenylisopropyl)phenoxy)methane, 1,4-bis((4',4''-dihydroxytriphenyl)methyl)benzene, and 3,3-bis(3-methyl-4-hydroxyphenyl)-2-oxo-2,3-dihydroindole.

[0055] Based on the number of moles of dihydroxyaryl compound used in each case, the amount of branching agent to be used optionally is preferably 0.05 mol% to 2.00 mol%.

[0056] The branching agent can be pre-loaded into the alkaline aqueous phase together with the dihydroxyaryl compound and the chain terminator or added by dissolving it in an organic solvent before phosgenation. In the case of the transesterification process, the branching agent is used together with the dihydroxyaryl compound.

[0057] Particularly preferred polycarbonates are bisphenol A-based homopolycarbonates, 1,3-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane-based homopolycarbonates and bisphenol A and 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane-based copolycarbonates, as well as homopolycarbonates or copolycarbonates derived from diphenols of the formula (I), (II) and / or (III),

[0058]

[0059] wherein in each case R' represents a C1 to C4 alkyl, aralkyl or aryl group, preferably represents a methyl or phenyl group, very particularly preferably represents a methyl group,

[0060] in particular with bisphenol A.

[0061] For incorporation of additives, component A is preferably used at least partly in the form of a powder, granules or a mixture of powder and granules.

[0062] The polycarbonate preferably has an MVR of 5 to 20 cm 3 / (10 min), more preferably 5.5 to 12 cm 3 / (10 min), still more preferably up to 8 cm 3 / (10 min), determined according to ISO 1133:2012-03 at a test temperature of 300 °C and a load of 1.2 kg.

[0063] Mixtures of different polycarbonates can also be used as the polycarbonate, for example a mixture of polycarbonate A1 and A2:

[0064] Based on the total amount of the polycarbonate, the amount of the aromatic polycarbonate A1 is preferably 25.0 to 85.0% by weight, preferably 28.0 to 84.0% by weight, particularly preferably 30.0 to 83.0% by weight, wherein this aromatic polycarbonate is based on bisphenol A and has a preferred melt volume flow rate MVR of 5 to 15 cm 3 / 10 min, more preferably has a melt volume flow rate MVR of 6 to 12 cm 3 / 10 min, determined according to ISO 1133 (test temperature 300 °C, mass 1.2 kg, DIN EN ISO 1133-1:2012-03).

[0065] Based on the total amount of the polycarbonate, the amount of the powdered aromatic polycarbonate A2 is preferably 2.0 to 12.0% by weight, preferably 3.0 to 11.0% by weight, particularly preferably 4.0 to 10.0% by weight, very particularly preferably 5.0 to 8.0% by weight, wherein this aromatic polycarbonate preferably is based on bisphenol A and has a melt volume flow rate MVR of 12 to 65 cm 3A preferred melt volume flow rate MVR of / (10 min), more preferably having 14 to 32 cm 3 A melt volume flow rate MVR of / (10 min), and particularly preferably having 15 to 20 cm 3 A melt volume flow rate MVR of / (10 min).

[0066] In the composition according to the invention, 50 to 98.5% by weight, preferably 80 to 98.0% by weight, more preferably 85 to 97.5% by weight, particularly preferably 90.0 to 97.5% by weight, very particularly preferably 93.0% to 97.5% by weight of aromatic polycarbonate is used in total.

[0067] Component B

[0068] Component B of the composition according to the invention is an interference pigment and / or a pearlescent pigment selected from metal oxide-coated mica. The mica can be naturally occurring or synthetically prepared mica, with the latter being preferred due to generally higher purity. Mica obtained from nature is usually accompanied by other minerals. In the case of mica obtained from nature, component B "mica" also includes impurities corresponding to the given amounts. Mica is preferably based on muscovite, i.e., it preferably comprises at least 60% by weight, more preferably at least 70% by weight, still more preferably at least 85% by weight, particularly preferably at least 90% by weight of muscovite, based on the total weight of the mica component of the interference pigment and / or the pearlescent pigment - without the metal oxide coating.

[0069] The metal oxide coating preferably comprises one or more coatings comprising titanium dioxide, tin oxide, aluminum oxide and / or iron oxide, wherein the metal oxide is more preferably iron(III) oxide (Fe2O3), iron(II,III) oxide (Fe3O4, a mixture composed of Fe2O3 and FeO) and / or titanium dioxide, particularly preferably titanium dioxide. Very particularly preferably, component B is titanium dioxide-coated mica.

[0070] The proportion of titanium dioxide in the total weight of the pigment is preferably 30 to 60% by weight, still more preferably 35 to 55% by weight, and the proportion of mica is preferably 40 to 70% by weight, still more preferably 45 to 65% by weight.

[0071] Rutile and / or anatase are preferably used as titanium dioxide. Particularly preferably, the pigment comprises anatase-coated mica; very particularly preferably, at least 90% by weight, preferably 95% by weight, more preferably at least 98% by weight of pigment component B is anatase-coated mica.

[0072] To increase the compatibility with the polymer matrix composed of polycarbonate, the pigment preferably also has a silicate and / or silica coating, in particular a sol-gel coating. This generally increases the weather resistance and chemical resistance of the pigment at the same time.

[0073] Determined by laser diffraction method for the aqueous slurry of the pigment, the median particle size (D 50 ) of the pigment is preferably 1 to 100 μm, more preferably 5 to 80 μm for synthetic mica, more preferably 3 to 30 μm for natural mica, generally particularly preferably 3.5 to 15 μm for mica, very particularly preferably 4.0 to 10 μm, and most preferably 4.5 to 8.0 μm. The D 90 value, also determined by laser diffraction method for the aqueous slurry of the pigment, is preferably 10 to 150 μm for synthetic mica and preferably 5 to 80 μm for natural mica. The density of the pigment, determined according to DIN EN ISO 1183-1:2013-04, is preferably 2.5 to 5.0 g / cm 3 , more preferably 2.8 to 4.0 g / cm 3 .

[0074] In the entire polycarbonate-based composition, the proportion of the at least one metal oxide-coated mica is 0.8 wt% to ≤5.0 wt%, preferably 1.0 to ≤3.0 wt%, more preferably 1.2 wt% to 2.5 wt%, and particularly preferably 1.5 wt% to 2.0 wt%.

[0075] Component C

[0076] Component C of the composition according to the invention is a copolymer or terpolymer of styrene with acrylic acid and / or methacrylic acid containing epoxy groups. The epoxy groups can be introduced by an unsaturated epoxide introduced together into the polymer. Such an unsaturated epoxide can be an acrylate or methacrylate having an epoxy group in a molecular moiety formally derived from an alcohol, such as glycidyl (meth)acrylate. Component C preferably comprises a copolymer of styrene with glycidyl methacrylate, and component C is particularly preferably a copolymer of styrene with glycidyl methacrylate.

[0077] According to the copolymer or terpolymer of component C, in particular the copolymer of styrene with glycidyl methacrylate, preferably has a styrene content of 30 to 70 wt%, more preferably 40 to 60 wt%, and particularly preferably 50 to 55 wt% determined by 1 1H-NMR spectrum in CDCl3.

[0078] The weight-average molar mass of the copolymer or terpolymer according to component C (in particular the copolymer of styrene and glycidyl methacrylate) determined by gel permeation chromatography in orthodichlorobenzene at 150 °C using polystyrene standards is preferably from 2000 to 25000 g / mol, more preferably from 3000 to 15000 g / mol, still more preferably from 5000 to 10000 g / mol, and particularly preferably from 6000 to 8000 g / mol.

[0079] The epoxy proportion of the polymer according to component C is preferably from 5 to 20% by weight, more preferably from 7 to 18% by weight, and particularly preferably from 10 to 15% by weight, determined according to DIN EN 1877-1:2000.

[0080] Such polymers are sold, for example, by BASF SE under the trademark Joncryl ® ADR.

[0081] The amount of component C in the overall composition is from 0.05% by weight to ≤ 3% by weight, preferably from 0.1% by weight to 2.0% by weight, more preferably from 0.12% by weight to 1.5% by weight, particularly preferably from 0.15% by weight to ≤ 1% by weight, especially to ≤ 0.5% by weight.

[0082] Component D

[0083] The composition according to the invention comprises from 0.001 to 0.500% by weight, preferably from 0.005 to 0.300% by weight, more preferably from 0.05% by weight to 0.270% by weight, still more preferably from 0.15 to 0.25% by weight, and particularly preferably from 0.08 to 0.18% by weight of one or more heat stabilizers, where component D comprises one or more phosphites as heat stabilizers.

[0084] In addition, stabilizers based on phosphine, based on phosphonites (in particular based on diphosphonites), based on phosphates may be present, which are selected from phenolic antioxidants or mixtures of at least two of the above compounds.

[0085] The phosphites in the sense of the present invention are understood to mean esters of phosphonic acids having the general structural formula P(OR)3 (usually also called phosphoric acid esters), where R represents an aliphatic and / or aromatic hydrocarbon radical, where the aromatic hydrocarbon radical may have further substituents, for example, branched and / or unbranched alkyl groups.

[0086] A phosphonate is understood to mean a compound derived from the basic structure R-PO(OH)₂, where R represents an aliphatic and / or aromatic hydrocarbon radical, and the aromatic hydrocarbon radical may have other substituents, such as branched and / or unbranched alkyl groups. The OH groups of the basic structure may be partially or completely esterified to the OR functional group, where R again represents an aliphatic and / or aromatic hydrocarbon radical, and the aromatic hydrocarbon radical may have other substituents, such as branched and / or unbranched alkyl groups, or may be partially or completely deprotonated, and the negative total charge is balanced by the corresponding counterion.

[0087] A phosphonite in the sense of the present invention is understood to mean an ester of phosphonous acid of the type R-P(OR)₂, in particular a diester, where R represents an aliphatic and / or aromatic hydrocarbon radical, and the aromatic hydrocarbon radical may have other substituents, such as branched and / or unbranched alkyl groups. Here, the phosphonite may have one phosphorus atom or multiple phosphorus atoms bridged by corresponding aliphatic and / or aromatic hydrocarbon groups.

[0088] The group R in the compound may be the same or different in each case.

[0089] There is no restriction on the choice of phosphine, and the phosphine compound is preferably selected from aliphatic phosphines, aromatic phosphines and aliphatic-aromatic phosphines.

[0090] The phosphine compound may be a primary, secondary and tertiary phosphine. Tertiary phosphines are preferably used, and among them, aromatic phosphines are particularly preferred, and tertiary aromatic phosphines are very particularly preferred.

[0091] Triphenylphosphine (TPP), trialkylphenylphosphine, bis(diphenylphosphino)ethane or trinaphthylphosphine are preferably used, and among them, triphenylphosphine (TPP) or a mixture of these phosphines is very particularly preferred.

[0092] In principle, mixtures of different phosphines can be used.

[0093] The preparation and properties of phosphine compounds are known to those skilled in the art and are described, for example, in EP0718354A2 and "Ullmanns Enzyklopädie der Technischen Chemie", 4th edition, volume 18, pages 378 - 398 and Kirk - Othmer, 3rd edition, volume 17, pages 527 - 534.

[0094] Regarding the amount of phosphine compound used in the stabilizer mixture, it should be taken into account that this substance may be oxidized depending on the temperature and residence time under specific processing conditions. The oxidized part is no longer available for stabilization. Therefore, the number of processing steps and the respective process conditions should be considered. Therefore, the composition also always contains a certain amount of oxidized phosphine, particularly preferably triphenylphosphine oxide, after heat treatment.

[0095] Preferably, the amount of phosphite stabilizer in the final product is > 0.01 wt%, more preferably > 0.02 wt%.

[0096] Even more preferably, the composition according to the invention comprises from 0.03 to 0.500 wt%, more preferably from 0.04 to 0.07 wt% of phosphite.

[0097] Suitable phosphite stabilizers obtainable within the scope of the present invention are, for example, Irgafos ® 168 (tris(2,4-di-tert-butyl-phenyl) phosphite / CAS No. 31570-04-4), Irgafos ® TPP (CAS No. 101-02-0), ADK PEPStab 36 (CAS No. 80693-00-1), Hostanox ® P-EPQ (CAS No. 119345-01-6) and Irgafos ® TNPP (CAS No. 26523-78-4), with Irgafos ® 168 being particularly preferred.

[0098] The group of antioxidants particularly includes sterically hindered phenols. Possible sterically hindered phenols are, for example, esters, n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate or β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid or esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, such as with methanol, ethanol, butanol, n-octanol, isooctanol, n-octadecanol 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tris(2-hydroxyethyl) isocyanurate, N,N'-bis(2-hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, esters of 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

[0099] Particularly preferably, n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is used as the sterically hindered phenol. Based on the total weight of the composition, the amount of the sterically hindered phenol is preferably from 0.01 to 0.1 wt%, preferably from 0.015 to 0.06 wt%.

[0100] Commercially available suitable phenolic antioxidants are, for example, Irganox ® 1076 (CAS No. 2082-79-3 / 2,6-di-tert-butyl-4-(octadecyloxycarbonylethyl)phenol) and Irganox ® 1010 (CAS No. 6683-19-8).

[0101] The stabilizer combination preferably comprises

[0102] a) 10% to 89% by weight, more preferably 20% to 78% by weight and particularly preferably 30% to 67% by weight of at least one phosphine stabilizer,

[0103] b) 10% to 89% by weight, more preferably 20% to 78% by weight and particularly preferably 30% to 67% by weight of at least one phosphite stabilizer, and

[0104] c) 1% to 50% by weight, more preferably 2% to 40% by weight and particularly preferably 3% to 20% by weight of at least one phenolic antioxidant,

[0105] wherein components a) - c) total 100% by weight.

[0106] In a particularly preferred embodiment, the stabilizer combination consists of triphenylphosphine, Irganox 1076 ® and bis(2,6 - di - tert - butyl - 4 - methylphenyl)pentaerythritol diphosphite.

[0107] Irganox ® 1010 (pentaerythritol - 3 - (4 - hydroxy - 3,5 - di - tert - butylphenyl)propionate; CAS No. 6683 - 19 - 8) can be used as a substitute for Irganox ® 1076.

[0108] The proportion of the stabilizer combination in the entire composition is 0.001% to 0.500% by weight, preferably 0.005% to 0.300% by weight, more preferably 0.05 to 0.270% by weight, and particularly preferably 0.15% to 0.25% by weight, based on the total weight of the composition.

[0109] In a preferred embodiment, the ratio of the phosphite stabilizer to the phenolic antioxidant is 1:5 to 10:1, more preferably 1:5 to 5:1 and particularly preferably 3:1 to 4:1.

[0110] In a more preferred embodiment, the ratio of the phosphine (a) to the mixture of phosphite and phenolic antioxidant (b + c) is preferably 8:1 to 1:9, more preferably 1:5 to 5:1, wherein the ratio of the phosphite stabilizer (b) to the phenolic antioxidant (c) is 1:5 to 10:1, more preferably 1:5 to 5:1 and particularly preferably 3:1 to 4:1.

[0111] Other phosphorus - based stabilizers or additional heat stabilizers can be used to stabilize the thermoplastic matrix, provided that these do not adversely affect the above - mentioned stabilization effect.

[0112] Component E

[0113] One or more additives commonly used for polycarbonate compositions can also be added to the composition containing aromatic polycarbonate as other additives, such as flame retardants, anti-dripping agents, impact modifiers, fillers, antistatic agents, colorants, including pigments different from Component B, and also including carbon black, lubricants and / or mold release agents, UV absorbers, IR absorbers, hydrolysis stabilizers, and / or compatibilizers. This group of other additives does not include the pigments according to Component B, that is, it does not include pearlescent pigments and / or interference pigments selected from metal oxide-coated mica, and does not include copolymers or terpolymers of styrene with acrylic acid and / or methacrylic acid containing epoxy groups, because these are called Component C. In addition, this group of other additives according to Component E does not include heat stabilizers, because these are already covered by the existing Component D.

[0114] The amount of other additives is preferably at most 10% by weight, more preferably at most 7% by weight, still more preferably at most 5% by weight, particularly preferably 0.01% to 3% by weight, and very particularly preferably at most 1% by weight, based on the entire composition.

[0115] Particularly suitable mold release agents for the compositions according to the invention are pentaerythritol tetrastearate (PETS) or glycerol monostearate (GMS), their carbonates / esters, and / or mixtures of these mold release agents.

[0116] Colorants including pigments in the sense of the present invention according to Component E are, for example, sulfur-containing pigments such as cadmium red and cadmium yellow, iron cyanide-based pigments such as Prussian blue, oxide pigments such as titanium dioxide, zinc oxide, red iron oxide, black iron oxide, chromium oxide, titanium yellow, zinc / iron-based brown, titanium / cobalt-based green, cobalt blue, copper / chromium-based black, and copper / iron-based black, or chromium-based pigments such as chrome yellow, dyes derived from phthalocyanine such as copper phthalocyanine blue and copper phthalocyanine green, fused polycyclic dyes and pigments such as azo groups (e.g., nickel azo yellow), thioindigo dyes, perinone-based, perylene-based, derivatives derived from Chinacridon, dioxazine-based, isoindolinone-based, and derivatives derived from Chinophthalone, anthraquinone-based heterocyclic systems, but in any case, there are no pearlescent pigments and / or interference pigments selected from metal oxide-coated mica.

[0117] Specific examples of commercial products are, for example, MACROLEX ® Blue RR, MACROLEX ® Violet 3R, MACROLEX ® EG, MACROLEX ®Violet B (Lanxess AG, Germany), Sumiplast ® Violet RR, Sumiplast ® Violet B, Sumiplast ® Blue OR, (Sumitomo Chemical Co., Ltd.), Diaresin ® Violet D, Diaresin ® Blue G, Diaresin ® Blue N (Mitsubishi Chemical Corporation), Heliogen ® Blue or Heliogen ® Green (BASF AG, Germany).

[0118] Among them, cyanin derivatives, quinoline derivatives, anthraquinone derivatives, and phthalocyanine derivatives are preferred.

[0119] As the carbon black, nanoscale carbon black is preferably used, and nanoscale pigment black is more preferably used. These preferably have an average primary particle size of less than 100 nm, preferably 10 to 99 nm, more preferably 10 to 50 nm, particularly preferably 10 to 30 nm, and especially 10 to 20 nm, as measured by scanning electron microscopy. Pigment black with a fine structure is particularly preferred.

[0120] Commercially available carbon blacks suitable in the context of the present invention can be obtained under various trade names and in various forms, such as pellets or powders. For example, suitable carbon blacks can be obtained under the trade name BLACK PEARLS ® in the form of wet-processed pellets, under ELFTEX ® , REGAL ® and CSX ® and in the form of a flaky appearance under MONARCH ® , ELFTEX ® , REGAL ® and MOGUL ® all from Cabot Corporation. Particularly preferred is the carbon black traded under the trade name BLACK PEARLS ® (CAS No. 1333-86-4).

[0121] The composition optionally contains an ultraviolet absorber. Suitable ultraviolet absorbers are compounds having as low a transmittance as possible below 400 nm and as high a transmittance as possible above 400 nm. Such compounds and their preparation are known from the literature and are described, for example, in EP0839623A1, WO1996 / 15102A2 and EP0500496A1. Ultraviolet absorbers which are particularly suitable for use in the compositions according to the invention are benzotriazoles, triazines, benzophenones and / or arylated cyanoacrylates.

[0122] The following ultraviolet absorbers are suitable, for example: hydroxybenzotriazoles such as 2-(3',5'-bis-(1,1-dimethylbenzyl)-2'-hydroxy-phenyl)benzotriazole (Tinuvin ® 234, BASF SE, Ludwigshafen), 2-(2'-hydroxy-5'-(t-octyl)phenyl)benzotriazole (Tinuvin ® 329, BASF SE, Ludwigshafen), 2-(2'-hydroxy-3'-(2-butyl)-5'-(t-butyl)phenyl)benzotriazole (Tinuvin ® 350, BASF SE, Ludwigshafen), bis-(3-(2H-benzotriazolyl)-2-hydroxy-5-t-octyl)methane, (Tinuvin ® 360, BASF SE, Ludwigshafen), (2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyloxy)phenol (Tinuvin ® 1577, BASF SE,Ludwigshafen), benzophenones 2,4-dihydroxybenzophenone (Chimasorb ® 22, BASF SE,Ludwigshafen) or 2-hydroxy-4-(octyloxy)benzophenone (Chimassorb ® 81, BASF SE,Ludwigshafen), 2-cyano-3,3-diphenyl-2-acrylic acid, 2,2-bis[[(2-cyano-1-oxo-3,3-diphenyl-2-propenyl)oxy]methyl]-1,3-propanediyl ester (9CI) (Uvinul ®3030, BASF SE, Ludwigshafen), 2-[2-hydroxy-4-(2-ethylhexyl)oxy]phenyl-4,6-bis(4-phenyl)phenyl-1,3,5-triazine (CGX UVA 006, BASF SE, Ludwigshafen) or tetraethyl-2,2'-(1,4-phenylenedimethylene) bismalonate (Hostavin ® B-Cap, Clariant AG). Mixtures of these UV absorbers can also be used.

[0123] Suitable IR absorbers are disclosed, for example, in EP1559743A1, EP1865027A1, DE10022037A1 and DE10006208A1. Among the IR absorbers mentioned in the cited documents, preference is given to those based on borides and tungstates, in particular cesium tungstate or zinc-doped cesium tungstate, and absorbers based on ITO and ATO and combinations thereof.

[0124] As impact modifiers, commonly used impact modifiers can be included. This group includes both core / shell-based systems such as ABS, MBS, acrylic-based, silicone-acrylic-based impact modifiers, and non-core / shell-based impact modifiers.

[0125] Organic and inorganic fillers can be added to the polycarbonate composition in conventional amounts. Suitable for this are in principle all finely ground organic and inorganic materials. These can have, for example, a granular, flaky or fibrous character. Mention may be made here by way of example of chalk, quartz powder, titanium dioxide, silicates / aluminosilicates, such as talc, wollastonite, montmorillonite, especially also in the form of organophilic modified by ion exchange, kaolin, zeolite, vermiculite and also alumina, silica, magnesium hydroxide and aluminum hydroxide. Mixtures of different inorganic materials can also be used.

[0126] Preferred inorganic fillers are one or more metals of main groups 1 to 5 and subgroups 1 to 8 of the periodic table, preferably main groups 2 to 5, particularly preferably main groups 3 to 5 and / or subgroups 4 to 8, with elemental oxygen, sulfur, boron, phosphorus, carbon, nitrogen, hydrogen and / or silicon in the most finely constituted (nanoscale) inorganic compounds.

[0127] Preferred compounds are, for example, oxides, hydroxides, hydrated / basic oxides, sulfates, sulfites, sulfides, carbonates, carbides, nitrates, nitrites, nitrides, borates, silicates, phosphates and / or hydrides.

[0128] Polytetrafluoroethylene (PTFE) is preferably used as a drip inhibitor, especially in an amount of 0.2 to 0.8% by weight.

[0129] It should be understood that the components used may contain conventional impurities, for example, generated by their preparation processes. Components as pure as possible are preferably used. Furthermore, it should be understood that these impurities may also be included in the closed preparations of the composition.

[0130] Particularly preferred thermoplastic compositions according to the invention are those comprising

[0131] A) 90.0 to 97.5% by weight, preferably 93.0 to 97.5% by weight of an aromatic polycarbonate, which preferably has an MVR of 5 to 20 cm 3 / (10 min), determined according to ISO 1133:2012-03 at a test temperature of 300 °C and a load of 1.2 kg,

[0132] B) 1.0 to 2.5% by weight, preferably 1.2 to 2.0% by weight of pearlescent pigments and / or interference pigments, said pearlescent pigments and / or interference pigments being selected from mica coated with titanium dioxide, particularly preferably comprising at least 98% by weight of anatase-coated mica,

[0133] C) 0.1 to 2.0% by weight, particularly preferably 0.2 to 1.2% by weight of a copolymer or terpolymer of styrene with acrylic acid and / or methacrylic acid containing epoxy groups,

[0134] D) 0.001 to 0.500% by weight, preferably 0.05 to 0.270% by weight of one or more heat stabilizers, wherein component D comprises a phosphite as a heat stabilizer, preferably comprising

[0135] i) phosphines, phosphites and phenolic antioxidants,

[0136] E) up to 7% by weight, preferably up to 5% by weight, particularly preferably 0.1 to 3% by weight, very particularly preferably up to 1% by weight of other additives, most preferably selected from flame retardants, anti-dripping agents, impact modifiers, fillers, antistatic agents, colorants, including pigments different from component B, further including carbon black, lubricants and / or release agents, hydrolysis stabilizers, compatibilizers, UV absorbers and / or IR absorbers.

[0137] According to the invention, "up to" in each case includes the value following these words as an upper limit.

[0138] Here, this group of other additives according to component E is very particularly preferably composed only of colorants, release agents, pigments different from component B, in particular carbon black.

[0139] A very particularly preferred thermoplastic composition according to the invention comprises

[0140] A) 90.0% to 97.5% by weight of an aromatic polycarbonate, which preferably has an MVR of 5 to 12 cm 3 / (10 min), determined according to ISO 1133:2012-03 at a test temperature of 300 °C and a load of 1.2 kg,

[0141] B) 1.2 to 2.0% by weight, preferably 1.5 to 2.0% by weight of pearlescent pigments and / or interference pigments selected from mica coated with metal oxides,

[0142] C) 0.2% to ≤1% by weight, particularly preferably 0.3% to 0.8% by weight of a copolymer or terpolymer of styrene with acrylic acid and / or methacrylic acid containing epoxy groups,

[0143] D) 0.05% to 0.270% by weight, most preferably 0.10% to 0.25% by weight of one or more heat stabilizers, wherein component D comprises one or more phosphites as heat stabilizers, which comprises, most preferably consists of,

[0144] i) phosphines, phosphites and phenolic antioxidants,

[0145] E) up to 7% by weight, preferably up to 3% by weight, most preferably up to 1% by weight of other additives, wherein the other additives are most preferably selected from colorants, lubricants, mold release agents, pigments different from component B, especially carbon black,

[0146] wherein component b is mica coated with titanium dioxide, most preferably comprising at least 98% by weight of anatase-coated mica.

[0147] The thermoplastic composition most preferably does not contain other components.

[0148] The preparation of the polymer composition according to the invention comprising the above components is carried out by conventional incorporation methods by combining, mixing and homogenizing the individual components, wherein homogenization is particularly preferably carried out in the melt under shear forces. Optionally, before melt homogenization, the combination and mixing are carried out using a powder premix.

[0149] It is also possible to use pellets or a premix of pellets and powder with the additive substances according to the invention.

[0150] It is also possible to use a premix prepared from a solution of the mixture components in a suitable solvent, wherein homogenization is optionally carried out in the solution and then the solvent is removed.

[0151] In this case, in particular, the components of the composition according to the invention and the above additives can be introduced by known methods or as masterbatches.

[0152] Particularly preferably, masterbatches are used for introducing the additives, in particular masterbatches based on the respective polymer matrix.

[0153] In this case, the composition can be combined, mixed, homogenized in common apparatuses such as a screw extruder (e.g., a twin-screw extruder (ZSK)), a kneader or a Brabender- or Banbury-mill and then extruded. After extrusion, the extrudate can be cooled and comminuted. It is also possible to premix the individual components and then to add the remaining starting materials individually and / or also mixed.

[0154] The preparation of plastic moldings from the compositions according to the invention can preferably be carried out by injection molding, extrusion or rapid heat cycle molding.

[0155] The compositions according to the invention are preferably used for preparing injection moldings, in particular those which are thin-walled and have a pearlescent appearance. The compositions according to the invention are likewise preferably used for preparing extrudates. In the context of the present invention, injection moldings and extrudates are understood as "moldings".

[0156] "Thin-walled" in the sense of the present invention are those moldings which have a wall thickness of less than about 3 mm, preferably less than 3 mm, more preferably less than 2.5 mm, still more preferably less than 1.5 mm and particularly preferably less than 0.5 mm at the thinnest point. In the context of the present invention, "about" means that the actual value does not deviate substantially from the stated value, where a deviation of not more than 25%, preferably not more than 10% is considered to be "substantially no". The present invention thus also provides corresponding moldings which comprise these compositions or consist of these compositions, collectively referred to as "moldings formed from these compositions".

[0157] These plastic moldings which consist of or comprise a composition according to the invention are likewise the subject of the present invention. Examples

[0158] A: Makrolon ® 3108 powder, from Covestro Deutschland AG. Linear polycarbonate based on bisphenol A, which has a melt volume flow rate MVR of 6 cm 3 / (10 min) (according to ISO 1133:2012-03, at a test temperature of 300 °C and a load of 1.2 kg). The test was carried out using an automatic flow tester from Zwick Roell, Ulm.

[0159] B: Pearlescent pigment. Mearlin ® Magnapearl ®3000 Anatase-coated mica, from BASF. The pearlescent pigment consists of mica coated with titanium dioxide. Muscovite was identified as the corresponding mica mineral by means of X-ray powder diffraction. The ratio of the two components was determined to be 56% mica and 44% anatase. The D50 value was determined to be 5.7 μm by means of a Malvern Mastersizer.

[0160] C: Copolymer of styrene and glycidyl methacrylate. Styrene proportion: 53% by weight, determined by means of 1 1H-NMR spectroscopy in CDCl3. M w = 7400 g / mol, determined by means of gel permeation chromatography in o-dichlorobenzene at 150 °C using polystyrene standards. The epoxy content, determined according to DIN EN 1877-1:2000, was 14% by weight.

[0161] D-1: ADK STAB ® PEP-36, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, available from Adeka Palmarole.

[0162] D-2: Hostanox PEPQ. A stabilizer mixture containing bis(2,4-di-tert-butylphenyl)-4,4'-biphenyldiphosphonite as the main component, available from Clariant.

[0163] D-3: Irganox ® 1076, n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, available from BASF SE.

[0164] D-4: Irganox ® B900, a mixture of 4 parts of Irgafos ® 168 and 1 part of Irganox ® 1076. Irgafos ® 168: tris(2,4-tert-butylphenyl) phosphite, available from BASF SE.

[0165] D-5: Triphenylphosphine, available from BASF SE.

[0166] E-1: Pentaerythritol tetrastearate; Loxiol VPG 861 from Emery Oleochemicals.

[0167] E-2: A mixture of common colorants, including carbon black.

[0168] The polycarbonate composition described in the following examples was prepared by kneading on an Evolum EV32 extruder from Clextral at a throughput of 50 kg / h. The melting temperature was 300 °C.

[0169] The melt volume flow rate (MVR) was determined according to ISO 1133:2012-03 (test temperature 300 °C, mass 1.2 kg) using an instrument Zwick 4106 from Zwick Roell.

[0170]

Claims

1. A thermoplastic composition comprising A) 90.0 wt% to 97.5 wt% of an aromatic polycarbonate, B) 1.2 wt% to 2.0 wt% of an interference pigment and / or pearlescent pigment selected from mica coated with a metal oxide, C) 0.1 wt% to ≤1 wt% of a copolymer or terpolymer of styrene with acrylic acid and / or methacrylic acid containing an epoxy group, D) 0.001 wt% to 0.500 wt% of one or more heat stabilizers, wherein component D includes one or more phosphites as heat stabilizers, and E) 0 to 7% by weight of other additives selected from a drip inhibitor, an impact modifier, a filler, an antistatic agent, a colorant, a lubricant, a mold release agent, a hydrolysis stabilizer, a compatibilizer, a UV absorber and / or an IR absorber, wherein, The colorant includes a pigment different from component B and also includes carbon black, wherein component B is a pearlescent pigment and / or interference pigment selected from mica coated with titanium dioxide and the polymer according to component C is a copolymer of styrene and glycidyl methacrylate, and wherein the composition does not include other components.

2. The thermoplastic composition according to claim 1, comprising A) 90.0 wt% to 97.5 wt% of an aromatic polycarbonate, B) 1.2 wt% to 2.0 wt% of an interference pigment and / or pearlescent pigment selected from mica coated with a metal oxide, C) 0.2 wt% to ≤1 wt% of a copolymer or terpolymer of styrene with acrylic acid and / or methacrylic acid containing an epoxy group, D) 0.001 wt% to 0.500 wt% of one or more heat stabilizers, wherein component D includes one or more phosphites as heat stabilizers.

3. The thermoplastic composition according to claim 1, wherein component D includes i) phosphine, phosphite and phenolic antioxidant as a phosphorus-containing heat stabilizer.

4. The thermoplastic composition according to any one of the preceding claims, which contains bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite as a heat stabilizer.

5. The thermoplastic composition according to claim 1, wherein component C has a styrene content of 30 to 70% by weight determined by means of 1 H-NMR spectroscopy in CDCl3, a weight-average molar mass of 2000 to 25000 g / mol determined by gel permeation chromatography in orthodichlorobenzene at 150 °C using polystyrene standards, and an epoxy proportion of 5 to 20% by weight determined according to DIN EN 1877-1:2000.

6. The thermoplastic composition according to any one of the preceding claims, which contains anatase-coated or rutile-coated mica as a pearlescent pigment and / or interference pigment selected from mica coated with a metal oxide.

7. The thermoplastic composition according to claim 1, which only optionally contains a colorant, a mold release agent and / or a pigment different from component B as other additives according to component E.

8. A molded article prepared from the thermoplastic composition according to any one of claims 1 to 7.

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