Transparent polycarbonate / polyacrylate blends

Abstract

The invention relates to a transparent polycarbonate / polyacrylate blend. An improved compatibility of a polycarbonate and a poly (meth) alkyl acrylate as a co-blending partner is described by adding a (meth) acrylate copolymer containing aromatic (meth) acrylate units and methyl methacrylate units. This makes it possible to obtain polycarbonate / poly (alkyl (meth) acrylate blends having good transmittance and significantly lower haze.

Description

Technical Field

[0001] The present invention relates to thermoplastic compositions containing polycarbonate and polyalkyl (meth)acrylate. Background Art

[0002] Thermoplastic compositions are suitable for a variety of applications and are a popular material option because they are easy to process and relatively easy to convert into a variety of different molded parts.

[0003] Polycarbonate is a particularly interesting material here because it has a high resistance to heat deformation and a high room temperature toughness. It can be provided in a variety of different material appearances. Depending on the formulation components, a wide range of different materials with a wide range of properties in terms of thermal, rheological and mechanical properties can be achieved. The application possibilities of polycarbonate are accordingly diverse, for example in the automotive industry, for rail vehicles, for the construction industry, in the electrical / electronics / IT industry, for battery housings, for household appliances, in the lighting industry for indoor and outdoor applications, for 3D printing or in the field of medical technology (medical products such as dialysis machines, Luer connection systems, stopcocks or pipe fittings).

[0004] Polymethyl methacrylate (PMMA) has better optical properties than aromatic polycarbonates. Thus, for example, the optical transmittance is higher due to its purely aliphatic character. For the same reason, the weathering stability is also better. Compared with polycarbonate based on bisphenol A (BPA-PC), components made of PMMA have a higher hardness and thus lower scratch sensitivity. However, disadvantages include the lower heat deformation resistance and lower toughness of PMMA compared with BPA-PC.

[0005] The combination of the individual material properties of BPA-PC and PMMA is therefore ideal from a technical point of view. However, the two polymers are miscible only with difficulty and are largely incompatible, which leads to opaque and in some cases milky components, so that corresponding transparent compositions containing these two polymers are not easily obtainable. It is therefore an object of the present invention to at least partially improve these disadvantages, in particular by reducing milkiness.

[0006] Surprisingly, it has been found that this object is achieved by adding a (meth)acrylate copolymer containing aromatic (meth)acrylate units c1 and methyl methacrylate units c2 to a composition containing aromatic (especially bisphenol A-based) polycarbonate and PMMA. This makes it possible to obtain polycarbonate / polyalkyl (meth)acrylate blends, especially PC / PMMA blends, by simple compounding, with a higher transmittance in the VIS range of the spectrum (380 to 780 nm) measured according to DIN ISO 13468-2:2006 (D65, 10°, layer thickness of the test plate 4 mm) and a reduced haze measured according to ASTM D1003:2013, both compared to corresponding compositions without (meth)acrylate copolymers. "Corresponding composition" is understood here to mean a composition containing other ingredients such as additives in the same amount, but containing more of the same aromatic polycarbonate instead of the (meth)acrylate copolymer in the comparative composition. Summary of the invention

[0007] The subject of the present invention is therefore a thermoplastic composition according to claim 1, namely a composition comprising

[0008] A) Aromatic polycarbonate having a melt volume flow rate MVR> 19 cm3 measured at a test temperature of 300°C and a load of 1.2 kg according to ISO 1133:2012-03 3 / (10min),

[0009] B) polyalkyl (meth)acrylates,

[0010] Features

[0011] The composition contains

[0012] C) a (meth)acrylate copolymer containing aromatic (meth)acrylate units c1 and methyl methacrylate units c2,

[0013] The composition contains >1 part by weight of a (meth)acrylate copolymer, ie, C, for each part by weight of B.

[0014] The present invention also provides for the use of (meth)acrylate copolymers containing aromatic (meth)acrylate units c1 and aliphatic methyl methacrylate units c2 for reducing the haze, determined in accordance with ASTM D1003:2013, of polycarbonate / polyalkyl (meth)acrylate blends and / or for reducing the opalescence, determined by visual evaluation, and thus for improving the compatibility of the components polycarbonate and polyalkyl (meth)acrylate.

[0015] Of course, the features listed as preferred for the composition according to the invention also apply to the use according to the invention.

[0016] Here and elsewhere, the term "(meth)acrylate" means either acrylate or methacrylate.

[0017] Compared to binary systems in which only polycarbonate and aliphatic polyalkyl (meth)acrylate components are present, the ternary systems according to the invention are characterized by improved compatibility, which is reflected in the optical properties of the ternary systems. Thus, for example, the haze of moldings, films or sheets produced by injection molding or extrusion is reduced and the transmittance for light in the VIS range of the spectrum (380 to 780 nm) is increased.

[0018] The use of polymethyl methacrylate in polycarbonate compositions is known. For example, JP 2016129962 A, JP 2015206051 A and JP 2014111799 A each describe a binary composition containing polycarbonate and polymethyl methacrylate. Improvements in surface hardness and reduced birefringence are described.

[0019] Improvements in surface hardness are also described in JP 2015003978 A and JP 2015003979 A. JP 2014065901 A describes a (meth)acrylate copolymer comprising methyl methacrylate units and aromatic (meth)acrylate units as blending partners of polycarbonate, which leads to improvements in surface hardness and excellent transparency of the composition.

[0020] The good surface hardness and high transparency of polycarbonate / polymethacrylate compositions are also described in WO 2013 / 11804 A1, JP 2014001267 A, JP 2012251107 A and JP 2012036263 A. The good scratch resistance of the compositions is also described.

[0021] However, none of these documents describes a ternary system comprising polycarbonate and two different acrylates, one of which is a polyalkyl (meth)acrylate, in particular polymethyl (meth)acrylate (PMMA).

[0022] The individual components of the composition according to the invention are explained in more detail below:

[0023] Component A

[0024] Component A of the composition according to the invention is an aromatic polycarbonate. This can be either a single aromatic polycarbonate or a mixture of different aromatic polycarbonates.

[0025] Aromatic polycarbonates in the context of the present invention include both homopolycarbonates and copolycarbonates and / or polyester carbonates; the polycarbonates may be linear or branched in a known manner.

[0026] The melt volume flow rate MVR of the aromatic polycarbonate used, determined in accordance with ISO 1133:2012-03 at a test temperature of 300° C. and a load of 1.2 kg, is preferably ≥ 20 cm 3 / (10min), more preferably ≥22cm 3 / (10min), particularly preferably ≥28cm 3 / (10 min), very particularly preferably ≥35 cm 3 / (10min), especially preferably ≥50cm 3 / (10 min). If the thermoplastic composition used according to the invention contains a mixture of different aromatic polycarbonates, any preferred ranges are to be understood as data for the entire mixture of aromatic polycarbonates.

[0027] A portion of the polycarbonates used according to the invention, up to 80 mol %, preferably 20 mol % to 50 mol % of the carbonate groups may be replaced by aromatic dicarboxylic acid ester groups. Such polycarbonates containing both acid groups of carbonic acid and acid groups of aromatic dicarboxylic acids incorporated into the molecular chain are referred to as aromatic polyester carbonates. In the present invention, they are covered by the umbrella term "thermoplastic aromatic polycarbonates".

[0028] Details regarding the production of polycarbonates have been disclosed in numerous patent documents over the past approximately 40 years. Reference may be made here, for example, to Schnell, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Vol. 9, Interscience Publishers, New York, London, Sydney 1964, pp. 9-72, to D. Freitag, U. Grigo, PR Müller, H. Nouvertné, BAYER AG, "Polycarbonates", Encyclopedia of Polymer Science and Engineering, Vol. 11, 2nd edition, 1988, pp. 648-718, and finally to U. Grigo, K. Kirchner and PR Müller "Polycarbonate", Becker / Braun, Kunststoff-Handbuch, Vol. 3 / 1, Polycarbonate, Polyacetale, Polyester, Celluloseester, Carl Hanser Verlag München, Wien 1992, pp. 117 to 299.

[0029] Aromatic polycarbonates are produced, for example, by the reaction of dihydroxyaryl compounds with carbonyl halides, preferably phosgene, and / or with aromatic dicarbonyl dihalides, preferably benzene dicarbonyl dihalides, by the phase interface process, optionally with the use of chain terminators and optionally with trifunctional or more than trifunctional branching agents. They can likewise be produced by the melt polymerization process by the reaction of dihydroxyaryl compounds with, for example, diphenyl carbonate.

[0030] For the production of polyester carbonates, a portion of the carbonic acid derivatives is replaced by aromatic dicarboxylic acids or dicarboxylic acid derivatives, and more precisely to the extent to which carbonate structural units in the aromatic polycarbonate are to be replaced by aromatic dicarboxylic ester structural units.

[0031] Dihydroxyaryl compounds suitable for producing polycarbonates are those of formula (1)

[0032] HO-Z-OH(1),

[0033] in

[0034] 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 aliphatic or alicyclic groups or alkylaryl groups or heteroatoms as bridging elements.

[0035] Preferably, Z in formula (1) is a group of formula (2)

[0036]

[0037] in

[0038] R 6 and R 7 Independently of each other, H, C1- to C 18 -alkyl, C1- to C 18 -alkoxy, halogen such as Cl or Br or in each case optionally substituted aryl or aralkyl, preferably H or C1- to C 12 -alkyl, particularly preferably H or C1- to C8-alkyl, very particularly preferably H or methyl, and

[0039] X is 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-alkyl, preferably methyl or ethyl, or a C6- to C6-alkyl group which may be optionally fused to another aromatic ring containing heteroatoms. 12 -Arylene.

[0040] X is preferably a single bond, C1- to C5-alkylene, C2- to C5-alkylidene, C5- to C6-cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO2-

[0041] or a group of formula (3)

[0042]

[0043] Examples of dihydroxyaryl compounds are: dihydroxybenzene, dihydroxybiphenyl, bis(hydroxyphenyl)alkanes, bis(hydroxyphenyl)cycloalkanes, bis(hydroxyphenyl)arenes, bis(hydroxyphenyl)ethers, bis(hydroxyphenyl)ketones, bis(hydroxyphenyl)sulfides, bis(hydroxyphenyl)sulfones, bis(hydroxyphenyl)sulfoxides, 1,1′-bis(hydroxyphenyl)diisopropylbenzene, and ring-alkylated and ring-halogenated compounds thereof.

[0044] Dihydroxy aromatic compounds suitable for producing polycarbonates include, 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, phthalimidine derived from isatin or phenolphthalein derivatives, and ring-alkylated, ring-arylated and ring-halogenated compounds thereof.

[0045] 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, dimethylbisphenol 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 as well as dihydroxyaryl compounds (I) to (III)

[0046]

[0047] Here, R' is each C1- to C4-alkyl, aralkyl or aryl, preferably methyl or phenyl, very particularly preferably methyl.

[0048] 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, 4,4′-dihydroxybiphenyl and dimethylbisphenol A, and the diphenols of the formulae (I), (II) and (III).

[0049] These and other suitable dihydroxyaryl compounds are described, for example, in US 3028635 A, US 2999835 A, US 3148172 A, US 2991273 A, US 3271367 A, US 4982014 A and US 2999846 A, DE 1570703 A, DE 2063050 A, DE 2036052 A, DE 2211956 A and DE 3832396 A, FR 1561518 A and JP 62039 / 1986 A, JP 62040 / 1986 A and JP 105550 / 1986 A.

[0050] In the case of homopolycarbonates, only one dihydroxyaryl compound is used; in the case of copolycarbonates, two or more dihydroxyaryl compounds are used.

[0051] Examples of suitable carbonic acid derivatives include phosgene or diphenyl carbonate.

[0052] Suitable chain terminators useful in the production of polycarbonates include monophenols. Examples of suitable monophenols include phenol itself, alkylphenols such as cresol, p-tert-butylphenol, cumylphenol, and mixtures thereof.

[0053] Preferred chain terminators are linear or branched, preferably unsubstituted, C1- to C 30 Particularly preferred chain terminators are phenol, cumylphenol and / or p-tert-butylphenol.

[0054] The amount of chain terminators used is preferably from 0.1 to 5 mol %, based on the number of moles of dihydroxyaryl compound used in each case. The chain terminators can be added before, during or after the reaction with the carbonic acid derivatives.

[0055] Suitable branching agents are the trifunctional or more than trifunctional compounds known from polycarbonate chemistry, in particular those having three or more than three phenolic OH groups.

[0056] Examples of suitable branching agents include 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 and 1,4-bis((4',4"-dihydroxytriphenyl)methyl)benzene and 3,3-bis(3-methyl-4-hydroxyphenyl)-2-oxo-2,3-dihydroindole.

[0057] The branching agents optionally used are preferably used in amounts of 0.05 mol % to 2.00 mol %, based on the moles of dihydroxyaryl compound used in each case.

[0058] The branching agent can be precharged with the dihydroxyaryl compound and the chain terminator in a basic aqueous phase or added before the phosgenation in the form dissolved in an organic solvent. In the case of the transesterification process, the branching agent is used together with the dihydroxyaryl compound.

[0059] Particularly preferred polycarbonates are homopolycarbonates based on bisphenol A, homopolycarbonates based on 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and copolycarbonates based on the two monomers bisphenol A and 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane or the two monomers bisphenol A and 4,4′-dihydroxybiphenyl, and homo- or copolycarbonates derived from dihydroxyaryl compounds of the formula (I), (II) and / or (III), in particular those containing bisphenol A.

[0060]

[0061] Here, R' is each C1- to C4-alkyl, aralkyl or aryl, preferably methyl or phenyl, very particularly preferably methyl.

[0062] Very particularly preferably, the aromatic polycarbonate comprises a homopolycarbonate based on bisphenol A. Very preferably, the aromatic polycarbonate is a homopolycarbonate based on bisphenol A.

[0063] If the corresponding copolycarbonates are present, the total proportion of monomer units of the formula (I), (II), (III), 4,4′-dihydroxybiphenyl and / or bisphenol TMC in the copolycarbonate is preferably 0.1 to 88 mol %, particularly preferably 1 to 86 mol %, very particularly preferably 5 to 84 mol % and in particular 10 to 82 mol % (based on the sum of the molar numbers of the dihydroxyaryl compounds used).

[0064] The relative solution viscosity of the copolycarbonate, determined according to ISO 1628-4:1999, is preferably in the range of 1.15-1.35.

[0065] The dihydroxyaryl compounds used, like all other chemicals and auxiliaries added to the synthesis, may be contaminated with impurities originating from their own synthesis, handling and storage. However, it is desirable to use raw materials of the highest possible purity.

[0066] Aromatic dicarboxylic acids suitable for producing polyester carbonates are, for example, phthalic acid, terephthalic acid, isophthalic acid, tert-butylisophthalic acid, 3,3′-diphenyldicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 4,4-benzophenonedicarboxylic acid, 3,4′-benzophenonedicarboxylic acid, 4,4′-diphenyletherdicarboxylic acid, 4,4′-diphenylsulfonedicarboxylic acid, 2,2-bis(4-carboxyphenyl)propane, trimethyl-3-phenylindan-4,5′-dicarboxylic acid.

[0067] Among the aromatic dicarboxylic acids, terephthalic acid and / or isophthalic acid are particularly preferably used.

[0068] Derivatives of dicarboxylic acids are dicarbonyl dihalides and dialkyl dicarboxylates, in particular dicarbonyl dichloride and dimethyl dicarboxylate.

[0069] The replacement of carbonate groups by aromatic dicarboxylate groups is essentially stoichiometric and quantitative, so that the molar ratio of the reactants is also maintained in the final polyester carbonate. The aromatic dicarboxylate groups can be incorporated either randomly or in blocks.

[0070] If the aromatic polycarbonates used are produced in a phase interface process, this is preferably achieved by continuous phase interface condensation, more preferably with high-viscosity workup steps such as venting extruders or strand evaporators for isolating the polycarbonate.

[0071] The composition according to the invention is based on aromatic polycarbonate and therefore contains at least 50% by weight, preferably at least 55% by weight, more preferably at least 60% by weight, particularly preferably at least 70% by weight of aromatic polycarbonate. The aromatic polycarbonate preferably comprises a homopolycarbonate based on bisphenol A, and the aromatic polycarbonate is particularly preferably a homopolycarbonate based on bisphenol A.

[0072] Component B

[0073] Component B is a polyalkyl (meth)acrylate. It will be appreciated that this can be one polyalkyl (meth)acrylate or a mixture of different polyalkyl (meth)acrylates. According to the invention, "polyalkyl (meth)acrylate" is understood to mean an unbranched polymer comprising only alkyl units and therefore no aromatic groups.

[0074] The polyalkyl (meth)acrylate according to component B may have a weight average molecular weight of 50,000 to 2,000,000 g / mol, preferably 80,000 to 300,000 g / mol, more preferably 100,000 to 200,000 g / mol, determined by gel permeation chromatography in tetrahydrofuran with PMMA calibration.

[0075] The polyalkyl (meth)acrylate preferably comprises

[0076] a) 52.0% to 100.0% by weight of repeating units of alkyl methacrylate having 1 to 20, preferably 1 to 12, more preferably 1 to 8 and particularly preferably 1 to 4 carbon atoms in the alkyl radical, in particular methyl methacrylate,

[0077] b) 0 to 48.0% by weight of repeating units of alkyl acrylate having 1 to 20, preferably 1 to 12, more preferably 1 to 8 and particularly preferably up to 4 carbon atoms in the alkyl group, in particular methyl acrylate, and

[0078] Contains no aromatic units.

[0079] It is very particularly preferred that the polyalkyl (meth)acrylate comprises at least 60.0% by weight, even more preferably at least 75.0% by weight and in particular at least 85.0% by weight of methyl methacrylate repeating units.

[0080] It is particularly preferred if the polyalkyl (meth)acrylate comprises 90.0% to 99.0% by weight of methyl methacrylate and 1.0% to 10.0% by weight of methyl acrylate, based in each case on the total weight of the polyalkyl (meth)acrylate.

[0081] The proportion of component B in the composition according to the invention is preferably less than 20% by weight, even more preferably 2 to 15% by weight, particularly preferably ≤10% by weight, very particularly preferably 5 to 10% by weight, based on the total composition.

[0082] Component C

[0083] Component C is a (meth)acrylate copolymer containing aromatic (meth)acrylate units c1 and aliphatic methyl methacrylate units c2. In the case of characterizations of component C below, it is to be understood that the data relate to component C as a whole, ie optionally to a mixture of different corresponding copolycarbonates.

[0084] Component C comprises aromatic (meth)acrylate units c1 and methyl methacrylate units c2 in a weight ratio (c1 / c2) of (5 to 80% by weight) / (20 to 95% by weight), preferably (10 to 30% by weight) / (70 to 90% by weight), the amounts being based on the total weight of component C. It is particularly preferred that component C contains no further units.

[0085] Aromatic (meth)acrylates are (meth)acrylates which carry an aromatic group in the ester moiety. Examples include phenyl (meth)acrylate and benzyl (meth)acrylate and mixtures thereof. Component C preferably comprises phenyl methacrylate and / or benzyl methacrylate, particularly preferably phenyl methacrylate.

[0086] Component C preferably comprises a copolycarbonate of methyl methacrylate and phenyl methacrylate, component C is particularly preferably such a copolycarbonate.

[0087] The weight average molecular weight of component C is preferably from 5000 to 30000 g / mol, more preferably from 10000 to 25000 g / mol, as determined by gel permeation chromatography in tetrahydrofuran against polystyrene standards.

[0088] Component C is contained in the composition according to the invention in an amount of >1 part by weight per part by weight of B, preferably in an amount of >1.5 parts by weight per part by weight of B, more preferably in an amount of ≥1.8 parts by weight per part by weight of B, and particularly preferably in an amount of ≥1.9 parts by weight per part by weight of B.

[0089] Component D

[0090] The polycarbonates of the ternary mixtures can in principle contain one or more conventional additives for polycarbonates in conventional amounts without significantly affecting the effect.

[0091] Preferably, one or more additional conventional additives are contained in an amount of 0 to 30% by weight, more preferably up to 10.0% by weight, even more preferably 0.01% to 6.0% by weight, particularly preferably 0.1% to 3.0% by weight, very particularly preferably 0.2% to 1.0% by weight, and in particular up to 0.5% by weight. The additional additive package does not contain polyalkyl (meth)acrylates, as this has already been described as component B. The additional additive package likewise does not contain (meth)acrylate copolymers containing aromatic (meth)acrylate units c1 and methyl methacrylate units c2 according to component C. The additional additive package also preferably does not contain inorganic pigments or fillers.

[0092] Additional additives such as those usually added to polycarbonates include, in particular, heat stabilizers, flame retardants, antioxidants, mold release agents, UV absorbers, infrared absorbers, antistatic agents, fluorescent whitening agents, transesterification inhibitors, colorants and / or additives for laser marking, in particular in the amounts conventionally used for compositions based on polycarbonates. Such additives are described, for example, in EP-A 0839623, WO-A 96 / 15102 or EP-A 0500496. These additives can be added individually or in mixtures. It should be appreciated that only additives that do not have a significant adverse effect on the transparent miscibility effect of the polycarbonate and polymethacrylate (alkyl) ester according to the present invention can be added and can only be added in an amount that does not have a significant adverse effect on this.

[0093] The additive is preferably selected from heat stabilizers, flame retardants, antioxidants, mold release agents, UV absorbers, infrared absorbers, antistatic agents, fluorescent brighteners, transesterification inhibitors, colorants and / or additives for laser marking. It is also more preferred that at least one heat stabilizer is included as an additional additive.

[0094] The additional additives are particularly preferably selected from ultraviolet absorbers, heat stabilizers, antioxidants, antistatic agents, mold release agents, transesterification inhibitors, and colorants.

[0095] Suitable flame retardants are those selected from the group consisting of alkali metal, alkaline earth metal or ammonium salts of aliphatic or aromatic sulfonic acids, sulfonamides and sulfonimide derivatives or combinations thereof. The composition according to the invention preferably contains no PTFE, since this has an adverse effect on the transmittance.

[0096] According to the invention, "derivatives" are understood here and elsewhere to mean compounds whose molecular structure contains different atoms or different atomic groups instead of hydrogen atoms or functional groups or in which one or more atoms / atomic groups have been removed. The parent compound is thus still identifiable.

[0097] As flame retardants, the composition according to the invention particularly preferably comprises one or more compounds selected from the group consisting of sodium or potassium perfluorobutane sulfate, sodium or potassium perfluoromethanesulfonate, sodium or potassium perfluorooctane sulfate, sodium or potassium 2,5-dichlorobenzene sulfate, sodium or potassium 2,4,5-trichlorobenzene sulfate, sodium or potassium diphenyl sulfone sulfonate, sodium or potassium 2-formylbenzenesulfonate, sodium or potassium (N-phenylsulfonyl)benzenesulfonamide or mixtures thereof.

[0098] Preference is given to using sodium or potassium perfluorobutane sulfate, sodium or potassium perfluorooctane sulfate, sodium or potassium diphenyl sulfone sulfonate or mixtures thereof. Very particular preference is given to potassium perfluoro-1-butane sulfonate, which can be used in particular as C4 was purchased from Lanxess, Leverkusen, Germany.

[0099] Preferred flame retardants further include phosphazenes, in particular cyclophosphazenes, polyphosphazenes and their derivatives and mixtures thereof, such as Rabitle FP110 (Fushimi Pharmaceutical Co. Ltd). The flame retardant is particularly preferably a phosphazene or a phosphazene mixture.

[0100] If used, the amount of alkali metal, alkaline earth metal and / or ammonium salts of aliphatic or aromatic sulfonic acids, sulfonamides and sulfonimide derivatives in the thermoplastic composition preferably amounts to 0.05% to 0.5% by weight, more preferably 0.06% to 0.3% by weight, particularly preferably 0.06% to 0.2% by weight, very particularly preferably 0.065% to 0.12% by weight and particularly preferably 0.065% to 0.9% by weight.

[0101] Preferred additives that are included in addition or as an alternative are heat stabilizers. Suitable heat stabilizers are in particular phosphorus-based stabilizers selected from phosphates, phosphites, phosphonites, phosphines and mixtures thereof. Different compounds from one of these subclasses, for example a mixture of two phosphites, can also be used. Heat stabilizers that are preferably used are phosphorus compounds with an oxidation number of +III, in particular phosphines and / or phosphites. Particularly preferred suitable heat stabilizers are triphenylphosphine, tris(2,4-di-tert-butylphenyl)phosphite ( 168), [1,1-biphenyl]-4,4'-diylbisphosphonite tetrakis(2,4-di-tert-butylphenyl) ester, 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl ester ( 1076), Pentaerythritol diphosphite bis(2,4-dicumylphenyl) ester ( S-9228), bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (ADK STAB PEP-36). They are used alone or in combination, such as Irganox B900 (a mixture of Irgafos 168 and Irganox 1076 in a ratio of 4:1) or Doverphos S-9228 with Irganox B900 or Irganox 1076.

[0102] The heat stabilizer is preferably used in an amount of up to 1.0% by weight, more preferably 0.003% by weight to 1.0% by weight, still more preferably 0.005% by weight to 0.5% by weight, particularly preferably 0.01% by weight to 0.2% by weight.

[0103] Preferred additives also include specific UV stabilizers with the lowest possible transmittance below 400 nm and the highest possible transmittance above 400 nm. UV absorbers particularly suitable for the composition according to the invention are benzotriazoles, triazines, benzophenones and / or arylated cyanoacrylates. Particularly suitable UV absorbers are hydroxybenzotriazoles, such as 2-(3',5'-bis(1,1-dimethylbenzyl)-2'-hydroxyphenyl)benzotriazole (Tinuvin 234, BASF SE, Ludwigshafen), 2-(2'-hydroxy-5'-(tert-octyl)phenyl)benzotriazole (Tinuvin 329, BASF SE, Ludwigshafen), bis(3-(2H-benzotriazolyl)-2-hydroxy-5-tert-octyl)methane (Tinuvin 360, BASF SE, Ludwigshafen), 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-(hexyloxy)phenol ( 1577, BASF SE, Ludwigshafen), 2-(5-chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl)-4-methylphenol (Tinuvin 326, BASF SE, Ludwigshafen), and benzophenones such as 2,4-dihydroxybenzophenone (Chimassorb 22, BASF SE, Ludwigshafen) and 2-hydroxy-4-(octyloxy)benzophenone (Chimassorb 81, BASF SE, Ludwigshafen), 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-di(4-phenyl)phenyl-1,3,5-triazine (Tinuvin 1600, BASF SE, Ludwigshafen), tetraethyl 2,2'-(1,4-phenylenedimethylene)bismalonate (Hostavin B-Cap, Clariant AG) or N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)oxalamide (Tinuvin 312, CAS No. 23949-66-8, BASF SE, Ludwigshafen). Particularly preferred specific UV stabilizers are Tinuvin 360, Tinuvin 329, Tinuvin 326, Tinuvin 1600, Tinuvin 312, Uvinul 3030 and / or Hostavin B-Cap, very particularly preferably Tinuvin 329 and Tinuvin 360. It is also possible to use mixtures of the UV absorbers mentioned.

[0104] If included, the composition preferably contains UV absorbers in an amount of up to 0.8% by weight, preferably 0.05% to 0.5% by weight, more preferably 0.08% to 0.4% by weight and very particularly preferably 0.1% to 0.35% by weight, based on the total composition.

[0105] The composition may also contain a phosphoric acid ester or a sulfonic acid ester as an ester exchange inhibitor. The ester exchange inhibitor preferably included is tri-isooctyl phosphate. Tri-isooctyl phosphate is preferably used in an amount of 0.003% to 0.05% by weight, more preferably 0.005% to 0.04% by weight, and particularly preferably 0.01% to 0.03% by weight, based on the total composition.

[0106] Preferred compositions according to the invention contain

[0107] A) at least 50% by weight of an aromatic polycarbonate having a melt volume flow rate MVR> 19 cm, measured according to ISO 1133:2012-03 at a test temperature of 300° C. and a load of 1.2 kg 3 / (10min),

[0108] B) polyalkyl (meth)acrylates,

[0109] Features

[0110] The composition contains

[0111] C) a (meth)acrylate copolymer containing aromatic (meth)acrylate units c1 and methyl methacrylate units c2,

[0112] The composition contains >1 part by weight of (meth)acrylate copolymer per part by weight of B.

[0113] A further preferred composition according to the invention consists of the following components

[0114] A) at least 55% by weight of an aromatic polycarbonate having a melt volume flow rate MVR> 19 cm, measured according to ISO 1133:2012-03 at a test temperature of 300° C. and a load of 1.2 kg 3 / (10min),

[0115] B) 2 to 20% by weight of polyalkyl (meth)acrylates,

[0116] Features

[0117] The composition contains

[0118] C) a (meth)acrylate copolymer containing aromatic (meth)acrylate units c1 and methyl methacrylate units c2,

[0119] wherein the composition contains >1 part by weight of a (meth)acrylate copolymer per part by weight of B,

[0120] D) optionally one or more additional additives selected from heat stabilizers, flame retardants, antioxidants, mold release agents, ultraviolet absorbers, infrared absorbers, antistatic agents, fluorescent brighteners, transesterification inhibitors, colorants and / or additives for laser marking, wherein the composition more preferably contains at least one heat stabilizer as an additional additive.

[0121] A particularly preferred composition consists of the following components

[0122] A) at least 70% by weight of an aromatic polycarbonate having a melt volume flow rate MVR> 19 cm, measured according to ISO 1133:2012-03 at a test temperature of 300° C. and a load of 1.2 kg 3 / (10 min), wherein the aromatic polycarbonate is preferably a homopolycarbonate based on bisphenol A,

[0123] B) 5 to 10% by weight of polyalkyl (meth)acrylates,

[0124] Features

[0125] The composition contains

[0126] C) a (meth)acrylate copolymer containing aromatic (meth)acrylate units c1 and methyl methacrylate units c2,

[0127] The composition contains >1.5 parts by weight of (meth)acrylate copolymer per part by weight of B, more preferably ≥1.8 parts by weight of (meth)acrylate copolymer per part by weight of B,

[0128] D) optionally one or more additional additives selected from heat stabilizers, flame retardants, antioxidants, mold release agents, ultraviolet absorbers, infrared absorbers, antistatic agents, fluorescent brighteners, transesterification inhibitors, colorants and / or additives for laser marking.

[0129] The production of the composition according to the invention comprising components A to C and optionally D is carried out by combining, mixing and homogenizing the ingredients by conventional incorporation methods, wherein in particular the homogenization is preferably carried out in the melt under the action of shear forces. Combining and mixing is optionally carried out using a powder premix before melt homogenization.

[0130] It is also possible to use premixes of pellets with components B, C and optionally D, with the polycarbonate or with the optional blending partner, or premixes of pellets and powder.

[0131] It is also possible to use premixes prepared from solutions of the mixture components in suitable solvents, with homogenization and subsequent removal of the solvent optionally being carried out in solution.

[0132] The components of the composition according to the invention can be introduced into the polycarbonate / polyalkyl (meth)acrylate mixture in particular by known methods or in the form of a masterbatch.

[0133] Masterbatches in aromatic polycarbonates and / or polyalkyl (meth)acrylates are preferably used for the separate or mixed incorporation of components C and / or D. Component C can thus be incorporated in the form of a masterbatch in component A or component B.

[0134] Component C is particularly preferably introduced into the composition according to the invention as a masterbatch in an aromatic polycarbonate or as a masterbatch in a polyalkyl (meth)acrylate.

[0135] In this respect, the composition according to the invention can be combined, mixed, homogenized and subsequently extruded in conventional apparatuses, such as screw extruders (e.g. twin-screw extruders, ZSK), kneaders or Brabender or Banbury mills. After extrusion, the extrudate can be cooled and comminuted. It is also possible to premix the individual components, to which the remaining raw materials can then be added individually and / or likewise mixed.

[0136] The merging and mixing of the premix in the melt can also be carried out in the plasticating unit of an injection molding machine. In this case, the melt is directly converted into a molded part in a subsequent step.

[0137] The compositions obtained accordingly are preferably used for producing moldings.

[0138] The production of the moldings is preferably carried out by injection molding, extrusion or from solution in a casting process. The compositions according to the invention can be processed in a customary manner in standard machines, for example in extruders or injection molding machines, to produce any moldings, for example films, plates or bottles.

[0139] The weathering stability brought about by the polyalkyl (meth)acrylate moiety is particularly, but not exclusively, advantageous in outdoor applications. The compositions according to the invention are therefore particularly suitable for producing swimming pool covers, stadium roofs, polycarbonate sheets for use in construction, for example for greenhouse and terrace roofs, lighting units, for example for street lamp housings, for switch cabinets and for housings of electrical devices and components, battery charging stations, automotive exterior parts such as diffuser panels or indicator covers, i.e. for moldings which are components for the above-mentioned applications and which are preferably intended to be subjected to weathering in their application.

[0140] Corresponding molded parts also include filaments for 3D printing. Further applications include tableware, bowls, mugs, glasses, cups, water bottles, automotive interior parts such as switches, display films and covers, medical applications, for example dialyzer housings or multi-way taps.

[0141] These and other molded parts consisting of the composition according to the invention or, for example in the case of multi-component injection molding, containing the composition according to the invention, including molded parts which constitute layers of multilayer systems or elements of the above-mentioned components or such components (made from ("composed of") these compositions according to the invention) likewise form the subject matter of the present application.

[0142] The composition according to the invention can be used as a material in 3D printing not only in the form of filaments but also as granules or powders.

[0143] The following examples are intended to illustrate the present invention but not to limit it. Specific implementation plan

[0144] Example

[0145] 1. Description of raw materials and test methods

[0146] The polycarbonate-based compositions and various masterbatches described in the following examples were produced by compounding on a ZE25 extruder from Berstorff at a throughput of 10 kg / h or on a DSM Miniextruder at a material temperature of 280° C. and a residence time of 5 minutes. Masterbatches of (meth)acrylate copolymers in aromatic polycarbonates and / or PMMA were used. The melt temperature was approximately 275° C.

[0147] a) Raw materials

[0148] A-1: Linear polycarbonate based on bisphenol A, produced by the interfacial process and terminated with tert-butylphenol, with >50 cm 3 Melt volume flow rate MVR of 100 % / (10 min) according to ISO 1133:2012-03 at a test temperature of 300° C. and a load of 1.2 kg. Contains about 250 ppm of heat stabilizer.

[0149] A-2: Linear polycarbonate based on bisphenol A, produced by the interfacial process and terminated with tert-butylphenol, with a 19 cm 3 The melt volume flow rate MVR of 300° C. / (10 min) (according to ISO 1133:2012-03 at a test temperature of 300° C. and a load of 1.2 kg).

[0150] B-1: From Polymethyl methacrylate PMMA 7N from GmbH, which has a 6cm 3 / (10 min) (according to ISO 1133:2012-03 at a test temperature of 230°C and a load of 3.8 kg).

[0151] C-1: Metablen H-880 from Mitsubushi Chemical Corp., Tokyo, a copolymer of methyl methacrylate (79.5 wt %) and phenyl methacrylate (20.5 wt %), M w = about 14000 g / mol, determined by gel permeation chromatography in tetrahydrofuran against polystyrene standards.

[0152] In order to improve the processing of the various components, masterbatches are prepared in advance. The following overview shows the composition of different masterbatches:

[0153] MB-1: A mixture consisting of 90 wt% A-1 and 10 wt% C-1

[0154] MB-2: A mixture consisting of 80 wt% A-1 and 20 wt% C-1

[0155] MB-3: A mixture consisting of 90 wt% A-2 and 10 wt% C-1

[0156] MB-4: A mixture consisting of 80 wt% A-2 and 20 wt% C-1

[0157] MB-5: A mixture consisting of 95 wt% B-1 and 5 wt% C-1

[0158] Masterbatches are clear, transparent compounds.

[0159] These masterbatches were used to produce the mixtures from Table 3 and more precisely in the amounts known from Table 1.

[0160] Table 1: Dosage of masterbatch

[0161] 4E 5E 6V 7V 8V 9E 10V 11E [weight%] [weight%] [weight%] [weight%] [weight%] [weight%] [weight%] [weight%] MB-1 95.0 90 90 MB-2 95.0 90 90 MB-3 95.0 MB-4 95.0 MB-5 10.0 10.0 B-1 5.0 5.0 5.0 5.0 10.0 10.0

[0162] b) Test methods

[0163] The test specimen plates were each produced by injection molding.

[0164] The reduction of opalescence determined by visual assessment - and the associated increase in clarity and reduction in haze - is an indicator of improved compatibility of components A and B.

[0165] In order to differentiate between the different compounds, the quality classes (QK) defined in the following table 2 were used. For the assessment of the QK classes, plaques with a thickness of 1.5 mm were produced in a DSM small injection molding machine.

[0166] Table 2: Quality rating of compounds in visual inspection

[0167] QK-1 Opaque compound, almost no transmittance, very high haze QK-2 Strong milky whitening, low transmittance, high haze QK-3 Moderate opalization, moderate transmittance, disturbing haze QK-4 Low opalescence, high transmittance, low haze QK-5 Very low opalescence, very high transmittance, no visible haze

[0168] In the following table, the comparative experiment is marked as "V" and the experiment of the present invention is marked as "E".

[0169] Table 2: Quality ratings of compounds and test specimens made from the compounds in visual inspection

[0170] 1V 2V 3V 4E 5E 6V 7V 8V 9E 10V 11E [weight%] [weight%] [weight%] [weight%] [weight%] [weight%] [weight%] [weight%] [weight%] [weight%] [weight%] A-1 95 85.5 76 81 72 81 72 A-2 95 5 85.5 76 B 5 95 5 5 5 5 5 10 10 9.5 9.5 C 9.5 19 9.5 19 9 18 9.5 18.5 QK- 2 1 3 4 5 2 3 2 4 3 5

[0171] Comparative Examples 1V, 2V and 3V show that compositions made of polycarbonate and component B, ie polyalkyl (meth)acrylate, PMMA in this case, are not miscible with one another easily without disruptive haze. The corresponding compositions exhibit opalescence and strong haze.

[0172] However, it can be seen from Examples 4E, 5E, 9E and 11E of the present invention that by adding component C, i.e. a (meth)acrylate copolymer containing aromatic (meth)acrylate units and aliphatic methyl methacrylate units, the transmittance can be significantly improved and the opalescence can be significantly reduced. However, this requires a certain minimum amount of component C relative to PMMA. 1 part by weight of component C relative to 1 part by weight of PMMA is not enough (Examples 8V, 10V), while a weight ratio of 1.8 to 1 (component E / component B, 9E) already achieves a significant improvement in the optical properties.

[0173] As can be seen from a comparison of inventive Examples 4E and 5E with Comparative Examples 6V and 7V, the polycarbonate component having a lower molecular weight achieves better results.

[0174] Furthermore, better quality grades are achieved if component C is introduced as a masterbatch of the two polymers to be mixed, namely polycarbonate and PMMA (experiments 10V, 11E compared with experiments 8V, 9E).

Claims

1. A thermoplastic composition comprising A) Aromatic polycarbonate having a melt volume flow rate MVR> 19 cm3 measured at a test temperature of 300°C and a load of 1.2 kg according to ISO 1133:2012-03 3 / (10min), B) polyalkyl (meth)acrylates, Features The composition contains C) a (meth)acrylate copolymer containing aromatic (meth)acrylate units c1 and methyl methacrylate units c2, The composition contains >1 part by weight of (meth)acrylate copolymer per part by weight of B.

2. The thermoplastic composition according to claim 1, wherein the composition contains ≥ 1.5 parts by weight of C per part by weight of B.

3. Thermoplastic composition according to claim 1 or 2, wherein the composition contains ≥1.8 parts by weight, preferably ≥1.9 parts by weight, of C per part by weight of B.

4. The thermoplastic composition according to claim 1, wherein the composition comprises at least 60% by weight of aromatic polycarbonate and 2% to 15% by weight of component B, in each case based on the total composition.

5. Thermoplastic composition according to any of the preceding claims, wherein component C comprises aromatic (meth)acrylate units c1 and methyl methacrylate units c2 in a weight ratio (c1 / c2) of (5% to 80% by weight) / (20% to 95% by weight), the data being based on the total weight of component C.

6. Thermoplastic composition according to any one of the preceding claims, wherein component B contains no aromatic moieties.

7. The thermoplastic composition according to any one of the preceding claims, wherein the aromatic polycarbonate has a melt volume flow rate MVR of ≥ 20 cm / s as determined according to ISO 1133:2012-03 at a test temperature of 300°C and a load of 1.2 kg. 3 / (10min).

8. The thermoplastic composition according to any one of the preceding claims, wherein the aromatic polycarbonate has a melt volume flow rate MVR of ≥ 35 cm / s as determined according to ISO 1133:2012-03 at a test temperature of 300°C and a load of 1.2 kg. 3 / (10min).

9. Thermoplastic composition according to any one of the preceding claims, consisting of components A, B and C and optionally one or more additives selected from heat stabilizers, flame retardants, antioxidants, mold release agents, UV absorbers, infrared absorbers, antistatic agents, fluorescent brighteners, transesterification inhibitors, colorants and / or additives for laser marking.

10. Mouldings made from the thermoplastic composition according to any one of the preceding claims.

11. The molded part according to claim 10, wherein the molded part is a swimming pool cover, a stadium roof, a lighting unit, a switch cabinet, a housing for an electrical device or component, a battery charging station, an automotive exterior part, an automotive interior part, tableware, a component of a medical product or a filament for 3D printing or a polycarbonate sheet in construction.

12. A process for producing a thermoplastic composition according to any one of claims 1 to 9, comprising the steps of: (i) mixing components A to C and optionally D in one or more steps, (ii) melt compounding the mixture obtained in step (i), optionally in the presence of further components, component C being preferably introduced as a masterbatch in component A and / or component B.

13. The process according to claim 12, wherein component C is introduced into the composition as a masterbatch in an aromatic polycarbonate.

14. The method according to claim 12, wherein component C is introduced into the composition as a masterbatch in component A and as a masterbatch in component B.

15. Use of a (meth)acrylate copolymer containing aromatic (meth)acrylate units c1 and aliphatic methyl methacrylate units c2 for reducing the haze of polycarbonate / polyalkyl (meth)acrylate blends, measured in accordance with ASTM D1003:2013, and / or for increasing the transmittance in the VIS range of the spectrum (380 to 780 nm), measured in accordance with DIN ISO 13468-2:2006 (D65, 10°, layer thickness of the test plate 4 mm), compared to a corresponding composition without the (meth)acrylate copolymer.

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