HIGH CTI POLYCARBONATE COMPOSITIONS

Description

[0001] The invention relates to flame-resistant thermoplastic compositions based on polycarbonate with high tracking resistance.

[0002] Due to its high impact strength, high heat resistance, and inherent flame retardancy, polycarbonate offers many advantages over other thermoplastic polymers. This unique property profile makes polycarbonate compositions suitable for a wide variety of applications, such as electrical and electronic components. In this context, good insulating properties and high flame retardancy are essential safety requirements for materials used in this area. In applications where the plastic is in direct contact with electrical conductors, high resistance to leakage currents under voltage load is required to prevent short circuits and subsequent fires within the component.

[0003] Tracking resistance (CTI, "comparative tracking index") generally describes the resistance of a plastic material to environmental influences. The CTI value is a measure of a plastic's tendency to form electrically conductive paths on its surface under environmental conditions such as moisture and contamination, thereby promoting the formation of electrical leakage currents. The higher the tracking resistance (CTI value) of a material, the better suited it is for use in high-voltage applications, such as those found in modern electromobility. Another advantage of materials with a high CTI value is that electrical conductors in an electronic component can be positioned closer together without risking a short circuit, which in turn allows for a reduction in component dimensions, resulting in more compact designs and weight savings.

[0004] Polycarbonate, unlike other thermoplastic polymers such as polystyrene and polyester, has very low tracking resistance and moderate flame retardancy. Due to its high proportion of aromatic structures, polycarbonate exhibits a relatively high tendency to char. The CTI (Closure Temperature Interruption) of pure polycarbonate is around 250 V or even lower (F. Acquasanta et al., Polymer Degradation and Stability, 96 (2011), 2098-2103). However, for numerous electrical / electronic (EE) applications, such as in electromobility, a high CTI, typically 600 V (corresponding to insulation group PLC 0 according to EN 50124), is required for safety reasons. Simultaneously, the materials must exhibit high flame retardancy, i.e., a V0 classification according to UL 94V, especially at thin wall thicknesses.

[0005] Pure polycarbonate typically possesses a certain degree of intrinsic flame retardancy (V2 classification according to UL 94V), but this is insufficient for most applications in the electrical, electronic, and fuel (EE) sector. To achieve the required V0 classification according to UL 94V, the addition of suitable flame retardants is necessary. Halogenated sulfonates (e.g., Rimar salt (potassium perfluorobutanesulfonate, C4 salt) or KSS salt (potassium diphenylsulfone-3-sulfonate)) or organic phosphates (e.g., bisphenol A bis(diphenyl phosphate) (BDP), resorcinol bis(diphenyl phosphate) (RDP)) or phosphazenes are typically used for polycarbonate. The mechanism of action of these flame retardants is based on the formation of a solid, charred surface layer that interrupts the oxygen supply and thus inhibits the combustion process.

[0006] The underlying effect for good tracking resistance is, among other things, a low tendency to form conductive paths on the surface. This directly contradicts the mechanism of action, "charring," of surface-active flame retardants and thus presents a particular challenge in coordinating CTI (conductive coating interaction) and flame retardancy.

[0007] Thermoplastic polycarbonate compositions with good creep resistance and flame retardancy are known from US2018 / 0187003 A1.

[0008] The objective was therefore to provide polycarbonate-based compositions that achieve a UL94 V0 classification at 3 mm, preferably at 2 mm, and particularly preferably at 1.5 mm, as well as a high CTI of, in particular, 600 V, preferably determined according to the rapid test method based on IEC 60112:2009. Due to the application and heat generation in electrical electrical components, the compositions should preferably also exhibit good heat resistance, in particular a Vicat softening temperature, determined according to ISO 306:2014-3, VST Method B, of at least 110°C.

[0009] Surprisingly, it has been shown that this can be achieved through special combinations of polycarbonate with polyethylene (PE) in combination with phosphorus-containing flame retardant and with fluorine-containing anti-drip agent.

[0010] The invention thus relates to a thermoplastic composition, which is free of flame retardants, selected from the group of alkali, alkaline earth, ammonium salts of aliphatic or aromatic sulfonic acid, sulfonamide or sulfonimide derivatives, containing A) at least 70 wt.% aromatic polycarbonate, B) > 2.0 wt.% to 6.0 wt.% polyethylene, C) 2.5 wt.% to < 8.0 wt.% phosphorus-containing flame retardant, D) 0.2 wt.% to 2.0 wt.% fluorinated anti-drip agent, wherein at least 0.5 wt.% fluorinated anti-drip agent is included if the composition contains > 4.0 wt.% polyethylene, and where the wt.% values ​​refer to the total composition.

[0011] The invention also relates to molded parts manufactured from the thermoplastic compositions according to the invention, i.e., molded parts consisting of a thermoplastic composition according to the invention or comprising a region of a thermoplastic composition according to the invention. Such molded parts are particularly those in which the aforementioned property profile is especially attractive, i.e., molded parts that are components or parts of components from the electrical and electronic equipment (EE) sector, in particular parts of high-voltage switches, inverters, relays, electronic connectors, electrical connectors, circuit breakers, components for photovoltaic applications, electric motors, heat sinks, chargers and plugs for electric vehicles, electrical junction boxes, smart meter housings, miniature disconnect switches, and busbars. Preferably, the component is designed for an operating voltage of at least 400 V.For this purpose, the material used preferably has a tracking resistance of at least 600 V, determined as described below in the example section according to the rapid test method in accordance with IEC 60112:2009.

[0012] The composition according to the invention can contain, in addition to components A, B, C, and D, further components, such as further additives in the form of component E. The composition can also contain one or more further thermoplastics as blend partners (component F) that are not covered by any of the components A to E. Within the scope of the present invention, the specified wt.% of components A, B, C, D, and, if applicable, E, as well as any blend partners, refer—unless explicitly stated otherwise—to the total weight of the composition. It is understood that all components contained in a composition according to the invention together constitute 100 wt.%. If the upper limit for a numerical range is specified as "up to X," this includes the stated numerical value and its rounding range.

[0013] Suitable blending partners, other than components A, B, and E, include, for example, polystyrene, styrene copolymers, aromatic polyesters such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), PET-cyclohexanedimethanol copolymer (PETG), polyethylene naphthalate (PEN), PMMA and PMMA copolymers, as well as copolymers with styrene such as transparent polystyrene acrylonitrile (PSAN), or thermoplastic polyurethanes. These blending partners are preferably used in concentrations of 0.5 wt% to 10 wt%.

[0014] However, the compositions described above most preferably contain no further components, but rather the amounts of components A, B, C, D and optionally E, particularly in the described preferred embodiments, supplement each other to 100 wt.%, i.e. the compositions according to the invention consist of components A, B, C, D, optionally E.

[0015] It is understood that the components used may contain common impurities, for example, those arising from their manufacturing processes. It is preferred to use components that are as pure as possible. It is further understood that these impurities may also be present in a closed formulation of the composition.

[0016] The compositions according to the invention show no significant leakage current (> 0.5 A over 2 s) when at least 50 drops of a 0.1% ammonium chloride solution are applied at 375 V, more preferably at 400 V, and particularly preferably at 600 V, the test preferably being carried out according to the rapid test method described in the descriptive section in accordance with IEC 60112:2009. Preferably, the compositions according to the invention have a flame retardancy V0 according to UL 94 V for test specimen thicknesses of 3 mm, more preferably for test specimen thicknesses of 2 mm, and even more preferably also for at least V1 at 1.5 mm, in each case after conditioning the test specimens for 7 days at 50% relative humidity and 70°C ambient temperature.Preferably, in addition to high CTI and good flame retardancy, the compositions also possess good heat resistance, which is reflected in a Vicat softening temperature, determined according to ISO 306:2014-3, VST method B, of at least 110°C.

[0017] The invention therefore also relates to the use of > 2.0 wt.% to 6.0 wt.%, preferably up to < 5.0 wt.% polyethylene, 2.5 to < 8.0 wt.% phosphorus-containing flame retardant and 0.2 to 2.0 wt.% fluorinated anti-drip agent, wherein the wt.% values ​​refer to the resulting total composition, to achieve a CTI of 600V and a UL94 V0 classification at a test specimen thickness of 3 mm, preferably at a test specimen thickness of 2 mm, and more preferably also at least V1 at 1.5 mm, in particular after conditioning the test specimens for 7 days at 50% relative humidity and 70°C ambient temperature, in a thermoplastic composition containing at least 70 wt.% aromatic polycarbonate.

[0018] The features mentioned as preferred, particularly preferred, etc. for the composition naturally also apply with regard to the use according to the invention.

[0019] The individual components of the compositions according to the invention are explained in more detail below: Component A

[0020] Component A of the compositions according to the invention are aromatic polycarbonates.

[0021] Aromatic polycarbonates within the meaning of the present invention are both homopolycarbonates and copolycarbonates and / or polyester carbonates; the polycarbonates can be linear or branched in a known manner. According to the invention, mixtures of polycarbonates can also be used.

[0022] The thermoplastic polycarbonates, including the thermoplastic aromatic polyester carbonates, preferably have weight-average molecular weights Mw of 15,000 g / mol to 40,000 g / mol, more preferably up to 34,000 g / mol, particularly preferably from 17,000 g / mol to 33,000 g / mol, and especially from 19,000 g / mol to 32,000 g / mol, determined by gel permeation chromatography calibrated against bisphenol A polycarbonate standards using dichloromethane as the eluent, calibration with linear polycarbonates (from bisphenol A and phosgene) of known molar mass distribution from PSS Polymer Standards Service GmbH, Germany, calibration according to method 2301-0257502-09D (dated 2009 in German) of Currenta GmbH & Co. OHG, Leverkusen. The eluent is dichloromethane. Column combination made of cross-linked styrene-divinylbenzene resins. Diameter of the analytical columns: 7.5 mm; length: 300 mm. Particle sizes of the column material: 3 µm to 20 µm.Solution concentration: 0.2 wt%. Flow rate: 1.0 ml / min. Solution temperature: 30°C. Use of UV and / or RI detection.

[0023] The melt volume flow rate (MVR) of the aromatic polycarbonate used, determined according to ISO 1133:2012-03, at a test temperature of 300°C and a load of 1.2 kg, is preferably 5 to 35 cm³ / (10 min), more preferably 6 cm³ / (10 min) to 25 cm³ / (10 min), and even more preferably 6 to 21 cm³ / (10 min).

[0024] A portion, up to 80 mol%, preferably 20 mol% to 50 mol%, of the carbonate groups in the polycarbonates used according to the invention can be replaced by aromatic dicarboxylic acid ester groups. Such polycarbonates, which contain both acid residues of carbonic acid and acid residues of aromatic dicarboxylic acids incorporated into the molecular chain, are referred to as aromatic polyester carbonates. Within the scope of the present invention, they are subsumed under the general term thermoplastic aromatic polycarbonates.

[0025] Details of the production of polycarbonates have been documented in numerous patents for approximately 40 years. Examples include 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, Second 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.

[0026] Aromatic polycarbonates can be produced, for example, by reacting dihydroxyaryl compounds with carbonic acid halides, preferably phosgene, and / or with aromatic dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalides, using an interfacial process, optionally with the use of chain terminators and optionally with the use of trifunctional or more than trifunctional branchers. Likewise, production via a melt polymerization process is possible by reacting dihydroxyaryl compounds with, for example, diphenyl carbonate.

[0027] For the production of polyester carbonates, some of the carbonic acid derivatives are replaced by aromatic dicarboxylic acids or derivatives of dicarboxylic acids, depending on the extent to which the carbonate structural units to be replaced in the aromatic polycarbonates are replaced by aromatic dicarboxylic acid ester structural units.

[0028] Dihydroxyaryl compounds suitable for the production of polycarbonates are those of formula (1) HO-Z-OH (1), in which Zein is an aromatic residue with 6 to 30 C atoms, which may contain one or more aromatic nuclei, may be substituted and may contain aliphatic or cycloaliphatic residues or alkylaryls or heteroatoms as bridging elements.

[0029] Preferably, Z in formula (1) represents a remainder of formula (2) in the R6< and R7< independently represent H, C1- to C18-alkyl, C1- to C18-alkoxy, halogen such as Cl or Br, or optionally substituted aryl or aralkyl, preferably H or C1- to C12-alkyl, particularly preferably H or C1- to C8-alkyl, and most preferably H or methyl, and 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 with C1- to C6-alkyl, preferably methyl or ethyl, and furthermore C6- to C12-arylene, which may optionally be condensed with aromatic rings containing further heteroatoms.

[0030] Preferably, X represents a single bond, C1 to C5 alkylenes, C2 to C5 alkylidenes, C5 to C6 cycloalkylidenes, -O-, -SO-, -CO-, -S-, -SO2- or a residue of formula (3)

[0031] Examples of dihydroxyaryl compounds are: dihydroxybenzenes, dihydroxydiphenyls, bis-(hydroxyphenyl)-alkanes, bis-(hydroxyphenyl)-cycloalkanes, bis-(hydroxyphenyl)-aryls, bis-(hydroxyphenyl)-ethers, bis-(hydroxyphenyl)-ketones, bis-(hydroxyphenyl)-sulfides, bis-(hydroxyphenyl)-sulfones, bis-(hydroxyphenyl)-sulfoxides, 1,1'-bis-(hydroxyphenyl)-diisopropylbenzenes and their nuclear-alkylated and nuclear-halogenated compounds.

[0032] Examples of dihydroxyaryl compounds suitable for the production of polycarbonates are hydroquinone, resorcinol, dihydroxydiphenyls, 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)diisopropylbenzenes, phthalimidines derived from isatin or phenolphthalein derivatives, and their nuclear-alkylated, nuclear-arylated, and nuclear-halogenated compounds.

[0033] Preferred dihydroxyaryl compounds are 4,4'-dihydroxydiphenyl, 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 dihydroxyaryl compounds (I) to (III) in which R' each represents a C 1 - to C 4 alkyl group, aralkyl group or aryl group, preferably a methyl group or phenyl group, most preferably a methyl group.

[0034] 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'-dihydroxydiphenyl and dimethyl-bisphenol A, as well as the bisphenols of formulas (I), (II) and (III).

[0035] These and other suitable dihydroxyaryl compounds are described, for example, in US 3 028 635 A, US 2 999 835 A, US 3 148 172 A, US 2 991 273 A, US 3 271 367 A, US 4 982 014 A and US 2 999 846 A, in DE 1 570 703 A, DE 2063 050 A, DE 2 036 052 A, DE 2 211 956 A and DE 3 832 396 A, in FR 1 561 518 A, in the monograph "H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964" as well as in JP 62039 / 1986 A, JP 62040 / 1986 A and JP 105550 / 1986 A described.

[0036] In the case of homopolycarbonates, only one dihydroxyaryl compound is used; in the case of copolycarbonates, two or more dihydroxyaryl compounds are used.

[0037] Suitable carbonic acid derivatives include, for example, phosgene or diphenyl carbonate.

[0038] Suitable chain terminators that can be used in the production of polycarbonates are monophenols. Suitable monophenols include, for example, phenol itself, alkylphenols such as cresols, p-tert-butylphenol, cumylphenol, and mixtures thereof.

[0039] Preferred chain terminators are phenols that are single or multiple substituted with C1 to C30 alkyl groups, linear or branched, preferably unsubstituted, or with tert-butyl. Particularly preferred chain terminators are phenol, cumylphenol, and / or p-tert-butylphenol.

[0040] The amount of chain terminator to be used is preferably 0.1 to 5 mol%, based on the number of moles of dihydroxyaryl compounds used. The addition of the chain terminator can take place before, during, or after the reaction with a carbonic acid derivative.

[0041] Suitable branchers are the tri- or more than trifunctional compounds known in polycarbonate chemistry, especially those with three or more than three phenolic OH groups.

[0042] Suitable branchers include, for example, 1,3,5-tri-(4-hydroxyphenyl)benzene, 1,1,1-tri-(4-hydroxyphenyl)ethane, tri-(4-hydroxyphenyl)phenylmethane, 2,4-bis-(4-hydroxyphenylisopropyl)phenol, 2,6-bis-(2-hydroxy-5'-methyl-benzyl)-4-methylphenol, 2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)propane, tetra-(4-hydroxyphenyl)methane, tetra-(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.

[0043] The amount of branching agents to be used, if applicable, is preferably 0.05 mol% to 2.00 mol%, based on moles of dihydroxyaryl compounds used.

[0044] The branching agents can either be placed in the aqueous alkaline phase with the dihydroxyaryl compounds and the chain terminations, or added dissolved in an organic solvent before phosgenation. In the case of the transesterification process, the branching agents are used together with the dihydroxyaryl compounds.

[0045] Particularly preferred polycarbonates are the homopolycarbonate based on bisphenol A, the homopolycarbonate based on 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, and the 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'-dihydroxydiphenyl, as well as the dihydroxyaryl compounds of formulas (I), (II) and / or (III). in which R' represents C1 to C4 alkyl, aralkyl, or aryl, preferably methyl or phenyl, and most preferably methyl, derived homo- or copolycarbonates, particularly with bisphenol A. Most preferably, the aromatic polycarbonate comprises a bisphenol A-based homopolycarbonate. Most preferably, the aromatic polycarbonate is a bisphenol A-based homopolycarbonate.

[0046] The total proportion of monomer units based on formulas (I), (II), (III), 4,4'-Dihydroxydiphenyl and / or Bisphenol TMC in the copolycarbonate is preferably 0.1 - 88 mol-%, particularly preferably 1 - 86 mol-%, most preferably 5 - 84 mol-% and particularly 10 - 82 mol-% (based on the sum of the moles of dihydroxyaryl compounds used).

[0047] The relative solution viscosity of the copolycarbonates, determined according to ISO 1628-4:1999, is preferably in the range of = 1.15 - 1.35.

[0048] The dihydroxyaryl compounds used, as well as all other chemicals and auxiliary substances added to the synthesis, can be contaminated with impurities originating from their own synthesis, handling, and storage. However, it is desirable to work with raw materials that are as pure as possible.

[0049] Copolycarbonates produced using diphenols of general formula (4a) are also preferred: where R 5< for hydrogen or C 1 - to C 4 - alkyl, C 1 - to C 3 - alkoxy, preferably for hydrogen; Methoxy or methyl, R6<, R7<, R8< and R9< each independently represent C1- to C4-alkyl or C6- to C12-aryl, preferably methyl or phenyl, Y represents a single bond, SO2-, -S-, -CO-, -O-, C1- to C6-alkylene, C2- to C5-alkylidene, C6- to C12-arylene, which may optionally be condensed with aromatic rings containing further heteroatoms or a C5- to C6-cycloalkylidene residue which may be substituted once or several times with C1- to C4-alkyl, preferably a single bond, -O-, isopropylidene or a C5- to C6-cycloalkylidene residue which may be substituted once or several times with C1- to C4-alkyl, V represents Oxygen, C2- to C6-alkylenes or C3- to C6-alkylidenes, preferably for oxygen or C3-alkylenes, p, q and r each independently stand for 0 or 1 when q = 0,W represents a single bond when q = 1 and r = 0, W represents oxygen, C2- to C6-alkylenes or C3- to C6-alkylidenes, preferably oxygen or C3-alkylenes when q = 1 and r = 1, W and V each independently represent C2- to C6-alkylenes or C3- to C6-alkylidenes, preferably C3-alkylenes, Z represents a C1- to C6-alkylene, preferably a C2-alkylene, o represents an average number of repeating units of 10 to 500, preferably 10 to 100, and m represents an average number of repeating units of 1 to 10, preferably 1 to 6, more preferably 1.5 to 5. It is also possible to use diphenols in which two or more siloxane blocks of the general formula (4a) are linked to each other via terephthalic acid and / or isophthalic acid to form ester groups.

[0050] Particularly preferred are (poly)siloxanes of formulas (5) and (6) where R1 represents hydrogen, C1 to C4 alkyl, preferably hydrogen or methyl, and particularly preferably hydrogen; R2 independently represents aryl or alkyl, preferably methyl; X represents a single bond, -SO2-, -CO-, -O-, -S-, C1 to C6 alkylene, C2 to C5 alkylidene, or C6 to C12 arylene, which may optionally be condensed with aromatic rings containing further heteroatoms; X preferably represents a single bond, C1 to C5 alkylene, C2 to C5 alkylidene, C5 to C12 cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO2-; X particularly preferably represents a single bond, isopropylidene, C5 to C12 cycloalkylidene, or oxygen, and most preferably isopropylidene; n represents an average number of 10 to 400, preferably 10 and 100, particularly preferably 15 to 50 means and m represents an average number of 1 to 10, preferably 1 to 6 and particularly preferably 1,5 to 5 stands.

[0051] The siloxane block can also preferably be derived from the following structure. preferred (Va) or where a in formula (IV), (V) and (VI) represents an average number of 10 to 400, preferably 10 to 100 and particularly preferably 15 to 50.

[0052] It is also preferred that at least two identical or different siloxane blocks of the general formulas (IV), (V) or (VI) are linked together via terephthalic acid and / or isophthalic acid to form ester groups.

[0053] Likewise, it is preferred if in formula (4a) p = 0, V stands for C 3 alkylene, r = 1, Z stands for C 2 alkylene, R 8< and R 9< stand for methyl, q = 1, W stands for C 3 alkylene, m = 1, R 5< stands for hydrogen or C 1 to C 4 alkyl, preferably for hydrogen or methyl, R 6< and R 7< each independently stand for C 1 to C 4 alkyl, preferably for methyl and o stands for 10 to 500.

[0054] Copolycarbonates with monomer units of formula (4a) and in particular their preparation are described in WO 2015 / 052106 A2.

[0055] Copolycarbonates with monomer units of formula (IV) and in particular their production are described in WO 2015 / 052106 A2.

[0056] Aromatic dicarboxylic acids suitable for the production of polyester carbonates include, for example, orthophthalic 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'-diphenyl etherdicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 2,2-bis-(4-carboxyphenyl)-propane, trimethyl-3-phenylindane-4,5'-dicarboxylic acid.

[0057] Of the aromatic dicarboxylic acids, terephthalic acid and / or isophthalic acid are particularly preferred.

[0058] Derivatives of dicarboxylic acids are the dicarboxylic acid dihalides and the dicarboxylic acid dialkyl esters, in particular the dicarboxylic acid dichlorides and the dicarboxylic acid dimethyl esters.

[0059] The replacement of the carbonate groups by the aromatic dicarboxylic ester groups is essentially stoichiometric and quantitative, so that the molar ratio of the reactants is also found in the finished polyester carbonate. The incorporation of the aromatic dicarboxylic ester groups can occur either statistically or in blocks.

[0060] The compositions according to the invention contain at least 70 wt.%, preferably at least 75 wt.%, more preferably at least 78 wt.%, even more preferably > 79.0 wt.%, particularly preferably at least 83 wt.%, most preferably 85 wt.% to < 95.3 wt.%, in particular up to 93.8 wt.%, aromatic polycarbonate, and are therefore based on aromatic polycarbonate. Component B

[0061] Component B is a polyethylene. Preferably, component B is HDPE (high-density polyethylene), HMWPE (high-molecular-weight polyethylene), UHMWPE (ultra-high-molecular-weight polyethylene), or a combination thereof.

[0062] HDPE is typically weakly branched and has a density of 0.94–0.97 g / cm³, determined according to ASTM D1505-18. The weight-mean molecular weight is preferably ≥ 200,000 g / mol, determined by high-temperature GPC in 1,2,4-trichlorobenzene.

[0063] HMWPE typically has a molecular weight Mw of 500,000–1,000,000 g / mol, determined by high-temperature GPC in 1,2,4-trichlorobenzene.

[0064] UHMWPE typically has a molecular weight Mw of > 1,000,000 to 6,000,000 g / mol, preferably of 4,000,000 to 6,000,000, determined by high-temperature GPC in 1,2,4-trichlorobenzene, and a density of 0.93-0.94 g / cm3, determined according to ASTM D1505-18.

[0065] The proportion of component B in the compositions according to the invention is > 2.0 wt.% to 6.0 wt.%, preferably to < 5.0 wt.%, more preferably 3 wt.% to 4 wt.%, particularly preferably 3.0 to 4.0 wt.%, based on the total composition. Component C

[0066] Component C of the compositions according to the invention comprises phosphorus-containing flame retardants. It can be a single phosphorus-containing flame retardant or a mixture of different phosphorus-containing flame retardants.

[0067] Preferred phosphorus-containing flame retardants are cyclic phosphazenes, phosphorus compounds of formula (10) and mixtures thereof: wherein R1<, R2<, R3< and R4< independently represent a C1 to C8 alkyl group, each optionally halogenated and each branched or unbranched, and / or a C5 to C6 cycloalkyl group, C6 to C20 aryl group or C7 to C12 aralkyl group, each optionally substituted by branched or unbranched alkyl and / or halogen, preferably chlorine and / or bromine, n independently represent 0 or 1, q represent a value of 0 to 30 and X represents a mono- or polynuclear aromatic group with 6 to 30 C atoms or a linear or branched aliphatic group with 2 to 30 C atoms, each of which may be substituted or unsubstituted, bridged or unbridged.

[0068] Preferably, R< , R< , R< , R< , and R< represent, independently of one another, branched or unbranched C1 to C4 alkyl, phenyl, naphthyl, or phenyl substituted with C1 to C4 alkyl. In the case of aromatic groups R< , R< , R< , R< , and / or R< , these may in turn be substituted with halogen and / or alkyl groups, preferably chlorine, bromine, and / or C1 to C4 alkyl, in branched or unbranched form. Particularly preferred aryl groups are cresyl, phenyl, xylenyl, propylphenyl, or butylphenyl, as well as the corresponding brominated and chlorinated derivatives thereof.

[0069] X in formula (10) is preferably derived from dihydroxyaryl compounds.

[0070] X in formula (10) particularly favorably represents or their chlorinated and / or brominated derivatives. Preferably, X (with the adjacent oxygen atoms) is derived from hydroquinone, bisphenol A, or diphenylphenol. Also preferably, X is derived from resorcinol. Particularly preferably, X is derived from bisphenol A. n in formula (10) is preferably equal to 1. q preferably represents 0 to 20, particularly preferably 0 to 10, in the case of mixtures for average values ​​of 0.8 to 5.0, preferably 1.0 to 3.0, more preferably 1.05 to 2.00, and particularly preferably 1.08 to 1.60.

[0071] A phosphorus compound of general formula (10) of formula (11) is preferred: wherein R1<, R2<, R3< and R4< each independently comprise a linear or branched C1 to C8 alkyl group and / or optionally a linear or branched alkyl-substituted C5 to C6 cycloalkyl group, C6 to C10 aryl group or C7 to C12 aralkyl group, n independently 0 or 1, q independently 0, 1, 2, 3 or 4, N a number between 1 and 30, R5 and R6 independently comprise a linear or branched C1 to C4 alkyl group, preferably a methyl group, and Y comprises a linear or branched C1 to C7 alkylidene, a linear or branched C1 to C7 alkylene group, C5 to C12 cycloalkylene group, C5 to C12 -Cycloalkylidene residue, -O-, -S-, -SO-, SO 2 or -CO- mean.

[0072] Phosphorus compounds of formula (10) include, in particular, tributyl phosphate, triphenyl phosphate, tricresyl phosphate, diphenylcresyl phosphate, diphenyloctyl phosphate, diphenyl-2-ethylcresyl phosphate, tri-(isopropylphenyl) phosphate, resorcinol-bridged oligophosphate, and bisphenol A-bridged oligophosphate. The use of oligomeric phosphoric acid esters of formula (10) derived from bisphenol A is particularly preferred.

[0073] Preferably, mixtures with the same structure but different chain lengths are used, with the specified q-value being the mean q-value. The mean q-value is determined by determining the composition (molecular weight distribution) of the phosphorus compound mixture using high-pressure liquid chromatography (HPLC) at 40°C in a 50:50 mixture of acetonitrile and water, and then calculating the mean values ​​for q from this.

[0074] Particularly preferred is the bisphenol A-based oligophosphate (bisphenol-A bis(diphenyl phosphate)) according to formula (12) with q = 1 to 20, in particular with q = 1.0 to 1.2, contained in the compositions according to the invention.

[0075] Such phosphorus compounds are known (see, e.g., EP 0 363 608 A1, EP 0 640 655 A2) or can be produced analogously using known methods (e.g., Ullmann's Encyclopedia of Industrial Chemistry, Vol. 18, pp. 301 ff., 1979; Houben-Weyl, Methods of Organic Chemistry, Vol. 12 / 1, p. 43; Beilstein Vol. 6, p. 177).

[0076] Cyclic phosphazenes according to formula (13) can be used as component C just as preferably as the phosphorus compounds according to formula (10): where Each is the same or different and represents an amine residue, a C1 to C8 alkyl residue, preferably methyl, ethyl, propyl or butyl, preferably a C1 to C8 alkoxy residue, preferably a methoxy, ethoxy, propoxy or butoxy residue, preferably a C5 to C6 cycloalkyl residue, preferably substituted by alkyl, preferably C1 to C4 alkyl, and / or halogen, preferably chlorine and / or bromine, preferably a C6 to C20 aryloxy residue, preferably a phenoxy or naphthyloxy residue, preferably a C1 to C4 alkyl, and / or halogen, preferably chlorine and / or bromine. substituted C7 to C12 aralkyl group, preferably phenyl C1 to C4 alkyl group,or a halogen group, preferably chlorine or fluorine, or an OH group, k represents an integer from 1 to 10, preferably a number from 1 to 8, particularly preferably 1 to 5, most preferably 1.

[0077] According to the invention, commercially available phosphazenes are particularly preferred. These are usually mixtures of cycles of different ring sizes.

[0078] Further preferred are, both individually and in mixtures: propoxyphosphazene, phenoxyphosphazene, methylphenoxyphosphazene, aminophosphazene, fluoroalkylphosphazene, and phosphazenes of the following structures:

[0079] In the compounds 13a-f shown above, k = 1, 2 or 3.

[0080] Preferably, the proportion of phosphazenes halogen-substituted on the phosphorus, e.g. from incompletely reacted starting material, is less than 1000 ppm, more preferably less than 500 ppm.

[0081] The phosphazenes can be used alone or as a mixture. The R group can always be the same, or two or more groups in the formulas can be different. Preferably, the R groups of a phosphazene are identical.

[0082] In one embodiment, only phosphazenes with the same R are used.

[0083] Preferably the proportion of tetramers (k = 2) is 2 to 50 mol%, based on component B, more preferably 5 to 40 mol%, even more preferably 10 to 30 mol%, and particularly preferably 10 to 22 mol%.

[0084] Preferably, the proportion of the higher oligomeric phosphazenes (k = 3, 4, 5, 6 and 7) is from 0 to 30 mol%, based on component B, more preferably from 2.5 to 25 mol%, even more preferably from 5 to 20 mol%, and particularly preferably from 6 to 15 mol%.

[0085] Preferably, the proportion of oligomers with k≥ 8 is from 0 to 2.0 mol%, based on component B, and preferably from 0.10 to 1.00 mol%.

[0086] Furthermore, the phosphazenes of component C preferably fulfill all three previously mentioned conditions regarding the proportion of oligomers.

[0087] Phenoxyphosphazene (all R = phenoxy, formula 13g), alone or with other phosphazenes according to formula (13) as component C, is particularly preferred, containing an oligomer with k = 1 (hexaphenoxyphosphazene) of 50 to 98 mol%, particularly preferably 60 to 72 wt%, based on the amount of phenoxyphosphazene as component C. When phenoxyphosphazene is used, the proportion of oligomers with k = 2 is most preferably 15 to 22 wt% and with k ≥ 3, 10 to 13 wt%.

[0088] Alternatively, and most preferably, component C comprises a phenoxyphosphazene with a trimeric fraction (k = 1) of 70 to 85 mol%, a tetrameric fraction (k = 2) of 10 to 20 mol%, a fraction of higher oligomeric phosphazenes (k = 3, 4, 5, 6 and 7) of 3 to 8 mol% and phosphazene oligomers with k ≥ 8 of 0.1 to 1 mol%, based on component C.

[0089] In an alternative preferred embodiment, n, defined as the arithmetic mean of k, is in the range of 1.10 to 1.75, preferably from 1.15 to 1.50, more preferably from 1.20 to 1.45, and particularly preferably from 1.20 to 1.40 (range limits included). n = ∑ i = 1 max k i ⋅ x i ∑ i = 1 max x i

[0090] Phosphazenes and their production are described, for example, in EP 728 811 A2, DE 1961668 A and WO 97 / 40092 A1.

[0091] The oligomer compositions in the respective blend samples can be detected and quantified after compounding using 31< P-NMR (chemical shift; δ trimer: 6.5 to 10.0 ppm; δ tetramer: -10 to -13.5 ppm; δ higher oligomers: -16.5 to -25.0 ppm).

[0092] Particularly preferably, component C comprises bisphenol-A based oligophosphate according to formula (12) and / or cyclic phosphazene according to formula (13); most preferably, component C comprises bisphenol-A based oligophosphate according to formula (12) and / or cyclic phosphazene according to formula (13).

[0093] The proportion of phosphorus-containing flame retardant in the compositions according to the invention is 2.5 wt.% to < 8.0 wt.%, preferably 3 wt.% to 6 wt.%, particularly preferably 4 to 6 wt.%, most preferably 4.0 to 6.0 wt.%, based on the total composition. Component D

[0094] The compositions according to the invention contain as component D a fluorine-containing anti-drip agent, which may be a mixture of several anti-drip agents. The total amount of anti-drip agent is 0.2 wt.% to 2.0 wt.%, preferably 0.21 wt.% to 1.6 wt.%, particularly preferably 0.25 wt.% to 1.0 wt.% of at least one anti-drip agent.

[0095] Fluorine-containing polymer, in particular polyolefin, is preferably used as an anti-drip agent.

[0096] The fluorinated polyolefins preferably used as anti-drip agents are high molecular weight and have glass transition temperatures above -30°C, generally above 100°C, with fluorine contents preferably from 65 wt.% to 76 wt.%, particularly from 70 wt.% to 76 wt.%. Preferred fluorinated polyolefins are polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene / hexafluoropropylene and ethylene / tetrafluoroethylene copolymers. Fluorinated polyolefins are well known (see "Vinyl and Related Polymers" by Schildknecht, John Wiley & Sons, Inc., New York, 1962, pages 484-494; "Fluorpolymers" by Wall, Wiley-Interscience, John Wiley & Sons, Inc., New York, Vol. 13, 1970, pages 623-654; "Modern Plastics Encyclopedia", 1970-1971, Vol. 47, No. 10 A, October 1970, McGraw-Hill, Inc., New York, pages 134 and 774; "Modern Plastics Encyclopedia", 1975-1976, October 1975, Vol. 52, No. 10 A, McGraw-Hill, Inc., New York, pages 27, 28 and 472 and US 3 671 487 A). 3 723 373 A and 3 838 092 A).They can be produced by known methods, for example by polymerization of tetrafluoroethylene in aqueous medium with a free radical-generating catalyst, such as sodium, potassium, or ammonium peroxide disulfate, at pressures of 7 to 71 kg / cm² and at temperatures of 0 to 200°C, preferably at temperatures of 20 to 100°C. Further details are described, for example, in US 2,393,967 A.

[0097] Depending on the application, the density of the fluorinated polyolefins can be between 1.2 and 2.3 g / cm³, preferably 2.0 g / cm³ to 2.3 g / cm³, determined according to ISO 1183-1 (2019-09), and the mean particle size can be between 0.05 and 1000 µm, determined by light microscopy or white light interferometry.

[0098] Suitable tetrafluoroethylene polymer powders are commercially available products and are offered, for example, by the company DuPont under the trade name Teflon®.

[0099] Polytetrafluoroethylene (PTFE), either as such or in the form of a PTFE-containing composition, is particularly preferred as a fluorinated anti-drip agent. If a PTFE-containing composition is used, the minimum amount used is such that at least 0.2 wt, preferably at least 0.21 wt%, and particularly preferably at least 0.25 wt% PTFE is present in the overall composition. PTFE-containing compositions include Hostaflon® < TF2021 or PTFE blends such as Blendex® < B449 (approx. 50 wt% PTFE and approx. 50 wt% SAN [from 80 wt% styrene and 20 wt% acrylonitrile]) from Chemtura. PTFE or a PTFE / SAN blend is most preferably used as the fluorinated anti-drip agent. Component E

[0100] The polycarbonate compositions according to the invention can contain one or more further additives different from components B, C and D, which are summarized here under "component E".

[0101] The composition optionally contains (0 wt%), preferably up to 20 wt%, more preferably up to 10 wt%, even more preferably 0.1 wt% to 5 wt%, particularly preferably 0.1 wt% to 3 wt%, and most preferably 0.2 wt% to 1.0 wt% other conventional additives ("further additives"), these wt% percentages referring to the total weight of the composition. The group of further additives does not include a phosphorus-containing flame retardant as defined in component C. In particular, the group of further additives also does not include a fluorine-containing anti-drip agent, as this is already described as component D.

[0102] Such additional additives, as are commonly added to polycarbonates, include in particular thermostabilizers, antioxidants, release agents, UV absorbers, IR absorbers, impact modifiers, antistatic agents, flame retardants (various with component C), optical brighteners, fillers, light scattering agents, hydrolysis stabilizers, transesterification stabilizers, (organic) dyes, (organic / inorganic) pigments, compatibility enhancers, flow improvers, and / or laser marking additives, especially in the amounts customary for polycarbonate-based compositions. Such additives are described, for example, in EP 0 839 623 A1, WO 96 / 15102 A1, EP 0 500 496 A1, or in the "Plastics Additives Handbook," Hans Zweifel, 5th Edition 2000, Hanser Verlag, Munich. These additives can be added individually or in mixtures and are preferred additives according to the invention.

[0103] Preferably, the product contains one or more further additives, if any, selected from the group consisting of thermostabilizers, antioxidants, release agents, organic dyes, organic pigments, and inorganic pigments. The proportion of these further additives is particularly preferably 0 to 3% by weight.

[0104] Particularly preferred is the inclusion of at least one further additive: a thermostabilizer, an antioxidant and / or a demolding agent.

[0105] It is understood that only such additives, and only in such quantities, may be added if they do not have a significantly negative impact on the inventive effect of high CTI and good flame retardancy, and preferably the Vicat temperature, determined according to ISO 306:2014-3, VST Method B, is not reduced below 110°C. Therefore, it is highly preferred that, in addition to the phosphorus-containing flame retardants according to component C, no more than 0.05 wt% of other flame retardants are included.

[0106] The compositions according to the invention may contain, in addition to component C, further flame retardants, but are free of such, selected from the group of alkali, alkaline earth, or ammonium salts of aliphatic or aromatic sulfonic acid, sulfonamide, or sulfonimide derivatives and combinations thereof, wherein "derivatives" are understood to be compounds whose molecular structure has a different atom or group of atoms in place of a hydrogen atom or a functional group, or from which one or more atoms / groups of atoms have been removed. The parent compound is thus still recognizable.

[0107] Such flame retardants, which are not included in the compositions according to the invention, are in particular 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 diphenylsulfonesulfonate, sodium or potassium 2-formylbenzenesulfonate, sodium or potassium (N-benzenesulfonyl)benzenesulfonamide or mixtures thereof, of which sodium or potassium perfluorobutane sulfate, sodium or potassium perfluorooctane sulfate, sodium or potassium diphenylsulfonesulfonate or mixtures thereof, in particular potassium perfluoro-1-butanesulfonate, which is commercially available, among other things as Bayowet®< C4 from Lanxess, Leverkusen, Germany.

[0108] Particularly preferred additives are release agents, more preferably based on a fatty acid ester, and even more preferably based on a stearic acid ester, particularly preferably based on pentaerythritol. Pentaerythritol tetrastearate (PETS) and / or glycerol monostearate (GMS) are particularly preferred. If one or more release agents are used, the amount is preferably up to 1.0 wt.% (inclusive), more preferably 0.01 to 0.7 wt.%, and particularly preferably 0.02 to 0.60 wt.%, in each case based on the total composition. Furthermore, if a release agent is included, the amount of fluorinated anti-drip agent is at least 0.5 wt.%, and particularly preferably at least 0.5 wt.% PTFE.

[0109] Particularly preferred additives include thermostabilizers. The amount of thermostabilizer is preferably up to 0.20 wt.%, more preferably 0.01 to 0.10 wt.%, even more preferably 0.01 to 0.05 wt.%, and particularly preferably 0.015 to 0.040 wt.%, based on the total composition.

[0110] Phosphorus-based stabilizers, selected from the group of phosphates, phosphites, phosphonites, phosphines and their mixtures, are particularly suitable as thermostabilizers. Examples are triphenyl phosphite, diphenyl alkyl phosphite, phenyldialkyl phosphite, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearylpentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite (Irgafos ® < 168), Diisodecylpentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-di-cumylphenyl)pentaerythritol diphosphite (Doverphos ®< S-9228), bis(2,6-di-tert-butyl-4-methylphenyl)penta-erythritol diphosphite, diisodecyloxypentaerythritol diphosphite, Bis(2,4-di-tert-butyl-6-methylphenyl)-pentaerythritol diphosphite, bis(2,4,6-tris(tert-butylphenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, 6-Isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz[d,g]-1,3,2-dioxaphosphocin, Bis(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite, bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocin, 2,2',2"-Nitrilo-[triethyltris(3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2'-diyl)phosphite], 2-ethylhexyl(3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2'-diyl)phosphite, 5-Butyl-5-ethyl-2-(2,4,6-tri-tert-butylphenoxy)-1,3,2-dioxaphosphiran, Bis(2,6-di-ter-butyl-4-methylphenyl)pentaerythritol diphosphite, triphenylphosphine (TPP), trialkylphenylphosphine, bisdiphenylphosphinoethane, or a trinaphthylphosphine. They are used alone or in mixtures, e.g., Irganox® < B900 (a mixture of Irgafos® < 168 and Irganox® < 1076 in a 4:1 ratio) or Doverphos® < S-9228 with Irganox® < B900 or Irganox® < 1076. Triphenylphosphine (TPP), Irgafos® < 168, or tris(nonylphenyl)phosphite, or mixtures thereof, are particularly preferred.

[0111] Furthermore, phenolic antioxidants such as alkylated monophenols, alkylated thioalkylphenols, hydroquinones, and alkylated hydroquinones can be used. Irganox® < 1010 (pentaerythritol-3-(4-hydroxy-3,5-di-tert-butylphenyl)propionate; CAS: 6683-19-8) and Irganox® < 1076 (octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) are particularly preferred, preferably in amounts of 0.05–0.5 wt.%.

[0112] Furthermore, sulfonic acid esters or alkyl phosphates, e.g., mono-, di-, and / or trihexyl phosphate, triisooctyl phosphate, and / or trinonyl phosphate, can be added as transesterification inhibitors. Triisooctyl phosphate (tris-2-ethylhexyl phosphate) is preferably used as the alkyl phosphate. Mixtures of various mono-, di-, and trialkyl phosphates can also be used. Triisooctyl phosphate is preferably used in amounts of 0.003 wt.% to 0.05 wt.%, more preferably 0.005 wt.% to 0.04 wt.%, and particularly preferably 0.01 wt.% to 0.03 wt.%, based on the total composition.

[0113] Examples of impact modifiers include: core-shell polymers such as ABS or MBS; olefin-acrylate copolymers such as Elvaloy® types from DuPont or Paraloid® types from Dow; and silicone acrylate rubbers such as the Metablen® types from Mitsubishi Rayon Co., Ltd. The compositions according to the invention already possess an excellent property profile without additional impact modifiers. Therefore, compositions according to the invention are preferably free of impact modifiers.

[0114] It is particularly preferred that the compositions according to the invention do not contain any fillers.

[0115] Particularly preferred compositions according to the invention consist of A) >79.0 wt.% aromatic polycarbonate, B) > 2.0 wt.% to 6.0 wt.%, in particular < 5.0 wt.%, polyethylene, C) 2.5 wt.% to < 8.0 wt.% phosphorus-containing flame retardant, D) 0.2 wt.% to 2.0 wt.% fluorinated anti-drip agent, wherein, if the composition contains > 4.0 wt.% polyethylene, at least 0.5 wt.% fluorinated anti-drip agent is included, E) 0 to 5 wt.-% one or more further additive(s) selected from the group consisting of thermostabilizers, antioxidants, release agents, UV absorbers, IR absorbers, antistatic agents, flame retardants other than those listed in component C, excluding alkali, alkaline earth, ammonium salts of aliphatic or aromatic sulfonic acid, sulfonamide or sulfonimide derivatives, optical brighteners, light scattering agents, hydrolysis stabilizers, transesterification stabilizers, organic dyes, organic pigments, inorganic pigments, compatibility enhancers, flow improvers, laser marking additives and mixtures thereof.

[0116] According to the invention, particularly preferred compositions consist of A) 83 wt.% to 93.8 wt.% aromatic polycarbonate, B) 3 wt.% to 4 wt.% polyethylene, C) 3 wt.% to 6 wt.% phosphorus-containing flame retardant, D) 0.2 wt.% to 2.0 wt.% fluorinated anti-drip agent, wherein, if the composition contains > 4.0 wt.% polyethylene, at least 0.5 wt.% fluorinated anti-drip agent is included, E) 0 to 5 wt.% one or more further additive(s) selected from the group consisting of thermostabilizers, antioxidants, release agents, UV absorbers, IR absorbers, antistatic agents, flame retardants other than component C, excluding alkali, alkaline earth, ammonium salts of aliphatic or aromatic sulfonic acid, sulfonamide or sulfonimide derivatives, optical brighteners, light scattering agents, hydrolysis stabilizers, transesterification stabilizers, organic dyes, organic Pigments, inorganic pigments, compatibility enhancers, flow improvers, laser marking additives and their mixtures..

[0117] Preferably, the phosphorus-containing flame retardant is either an organophosphate, in particular one of formula (12), where q = 1 to 20, in particular 1.0 to 1.2, or a phosphazene of formula (13g) with k = 1, 2 or 3, including mixtures thereof. It is understood that this is preferably a mixture of different oligomers of this formula, since mixtures are commonly available commercially. Most preferably, the phosphorus-containing flame retardant of one of formula (12) or (13g), as defined above, is included.

[0118] In the compositions described as preferred, further preferred, particularly preferred, etc., the molecular weight of the polyethylene used is preferably at least 200,000 g / mol, determined by high-temperature GPC in 1,2,4-trichlorobenzene.

[0119] The polymer compositions according to the invention, containing the mixed components A, B, C, D, and optionally E, as well as optionally other components, can be produced using powder premixes. Premixes of granules or granules and powders with the additives according to the invention can also be used. Premixes prepared from solutions of the mixture components in suitable solvents, optionally homogenized in solution and the solvent subsequently removed, can also be used. In particular, the additives designated as component E and also other components of the compositions according to the invention can be introduced by known methods or as a masterbatch. The use of masterbatches is particularly preferred for introducing additives and other components, with masterbatches based on the respective polymer matrix being especially favored.

[0120] The compositions according to the invention can, for example, be extruded. After extrusion, the extrudate can be cooled and comminuted. The combination and mixing of a premix in the melt can also take place in the plasticizing unit of an injection molding machine. In the subsequent step, the melt is transferred directly into a molded part.

[0121] The compositions according to the invention are preferably used for the production of molded parts for components from the EE sector, in particular for high-voltage switches, inverters, relays, electronic connectors, electrical connectors, circuit breakers, components for photovoltaic applications, electric motors, heat sinks, chargers or charging plugs for electric vehicles, electrical junction boxes, smart meter housings, miniature disconnect switches; power bus bars.

[0122] The subject matter of the invention is therefore molded parts consisting of or comprising areas of compositions according to the invention, as well as corresponding components or parts of components comprising elements, i.e. molded parts, which consist of compositions according to the invention or comprise areas consisting of compositions according to the invention.

[0123] Preferably, the component is designed for an operating voltage of at least 400 V. However, it can also be designed for a standard household operating voltage of 230 V ± 23 V in Europe. This allows for smaller distances between the electrical conductors.

[0124] The high tracking resistance of the polycarbonate compositions according to the invention makes it possible to achieve smaller distances between two electrical conductors of a component using the polycarbonate material than has previously been possible when using polycarbonate.

[0125] The invention therefore also relates to an EE component comprising a first electrical conductor and a second electrical conductor at a first distance d1 and a second distance d2 from each other, which are connected via an element made of a thermoplastic composition according to the invention, which is in direct contact with the first electrical conductor and the second electrical conductor, wherein the distance d1 is the shortest distance between the first electrical conductor and the second electrical conductor along the surface of the element made of the thermoplastic composition, and wherein the distance d2 is the shortest distance between the first electrical conductor and the second electrical conductor through the air, wherein d2 is selected such that a flashover through the air is prevented at the respective operating voltage, and wherein d1 is, at the following operating voltage U: d1i(0V ≤ U ≤ 250V): 1.8 mm to < 2.5 mm; d1ii(250 V < U ≤ 500 V): 3.6 mm to < 5.0 mm; d1iii(500 V < U ≤ 1000 V): 7.1 mm to < 10.0 mm.

[0126] Such small distances are only achievable with a material that has a CTI of at least 400 V.

[0127] "Element made of a thermoplastic composition according to the invention" means that an element is present which consists of a thermoplastic composition according to the invention, i.e. the composition has not been mixed with additional components.

[0128] If the material has a CTI of 600 V, even smaller distances are achievable, so that d1 is preferably: d1i(0V ≤ U ≤ 250V): 1.3 mm to < 2.5 mm, dlii(250 V < U ≤ 500 V) = 2.5 mm to < 5.0 mm, dliii(500 V < U ≤ 1000 V) = 5.0 mm to < 10.0 mm.

[0129] Particularly preferably, when using a material with a CTI of 600V at the listed operating voltage, d1 is: dli(0V ≤ U ≤ 250V): 1.3 mm to < 1.8 mm, dlii(250 V < U ≤ 500 V) = 2.5 mm to < 3.6 mm, d1iii(500 V < U ≤ 1000 V) = 5.0 mm to < 7.1 mm, distances which are not achievable even with a material with a CTI of 400 or 450 V, but require a CTI of 600 V.

[0130] As is well known, the degree of pollution affects electrical conductivity. The specified distances d1 and d2 are practically applicable to components where, for example due to structural shielding, an IP6K9K protection rating according to ISO 20653:2013-02 can be maintained.

[0131] According to the invention, preferred thermoplastic compositions belong to insulating material group II (400 V ≤ CTI < 600 V), and particularly preferred compositions belong to insulating material group I (600 V ≤ CTI), classified according to DIN EN 60664-1. Examples 1. Description of raw materials and testing methods a) Raw materials

[0132] Component A-1: Linear polycarbonate based on bisphenol A with a melt volume flow rate of 12 cm³ / (10 min) (according to ISO 1133:2012-03, at a test temperature of 300°C and a load of 1.2 kg), containing as component E-3 250 ppm (= 0.025 wt.%, based on the total weight of component A) thermostabilizer triphenylphosphine.

[0133] Component A-2: Linear polycarbonate based on bisphenol A with a melt volume flow rate of 6 cm³ / (10 min) (according to ISO 1133:2012-03, at a test temperature of 300°C and a load of 1.2 kg).

[0134] Component B-1: Ultra-high molecular weight polyethylene (UHMWPE) UMFI 30X from Shamrock Technologies with a mean particle diameter (D 50 ) of 30 µm, determined by laser diffraction according to ISO 13320:2009.

[0135] Component B-2:High density Polyethylene Formolene LH5320 from Formosa Plastics with a density of 0.953 g / cm 3< , determined according to ASTM D1505-18 and a melt volumetric flow rate of 20 g / 10 min, measured according to ASTM D1238-20.

[0136] Component C-1: Organophosphate of formula (12) with q = 1.0 - 1.2. Bisphenol-A bis(diphenyl phosphate) from Adeka.

[0137] Component C-2: Phenoxycyclophosphazene Rabitle FP110 from Fushimi Pharmaceutical, Japan, formula (13g), with a trimerene content (k = 1) of approximately 68 mol-%.

[0138] Component Cx: Potassium perfluoro-1-butanesulfonate, commercially available as Bayowet®< C4 from Lanxess AG, Leverkusen, Germany, CAS No. 29420-49-3.

[0139] Component D-1: In SAN-encapsulated polytetrafluoroethylene ADS5000 (approx. 50 wt.% PTFE (fluorinated anti-drip agent) and approx. 50 wt.% SAN) from Chemical Innovation Co., Ltd. Thailand.

[0140] Component D-2:Fluorinated anti-drip agent. Polytetrafluoroethylene Teflon CFP6000X from Chemours Netherlands BV

[0141] Component E-1: Release agent. Pentaerythritol tetrastearate, commercially available as Loxiol VPG 861 from Emery Oleochemicals Group.

[0142] Component E-2: Antioxidant. Irganox® < B900 of BASF (mixture of Irgafos® < 168 (Tris-(2,4-di-tert-butylphenyl)phosphite) and Irganox® < 1076 (Octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) in a weight ratio of 4:1). b) Testing methods Tracking resistance (“comparative tracking index”, CTI):

[0143] To determine the tracking resistance, the compositions described here were tested using the rapid test method based on IEC 60112:2009. For this purpose, a 0.1% ammonium chloride test solution (395 Ω·cm resistance) was applied dropwise between two electrodes spaced 4 mm apart onto the surface of test specimens measuring 60 mm x 40 mm x 4 mm at 30-second intervals. A test voltage was applied between the electrodes, which was varied during the test. The first test specimen was tested at a starting voltage of 300 V or 350 V. A maximum of 50 drops (one drop every 30 seconds) were applied per voltage, as long as no tracking current > 0.5 A occurred for 2 seconds or the specimen burned. After 50 drops, the voltage was increased by 50 V, and a new test specimen was tested at this higher voltage according to the procedure described above.This process continued until either 600 V was reached or a leakage current or fire occurred. If one of the aforementioned effects occurred with fewer than 50 drops, the voltage was reduced by 25 V and a new test specimen was tested at this lower voltage. The voltage was reduced until the test with 50 drops was passed without leakage current or fire. This procedure thus determined the maximum possible voltage at which a composition could withstand 50 drops of the test solution without leakage current occurring. Finally, to confirm the determined maximum voltage, four further test specimens, each with 50 drops, were tested. This confirmed value is given as CTI in the examples. A 100-drop value was not determined; therefore, this is referred to as a "rapid test method based on the aforementioned standard." Flame retardancy:

[0144] The flame retardancy testing of the polycarbonate compositions was carried out according to Underwriters Laboratory method UL 94 V in thicknesses of 1.5 mm to 3 mm. The test specimens were previously conditioned for 7 days at 50% relative humidity and an ambient temperature of 70°C.

[0145] Different fire classes are assigned depending on the behavior of the test specimens. These include the time until the flame extinguishes, resistance to dripping, and whether a material drips while burning. The classes determined according to these criteria are designated V0, V1, and V2 and are based on a total of five tested specimens.

[0146] V0:The test specimen, positioned with its longitudinal axis at 180° (vertical) to the flame, has an average afterburn time of no more than 10 seconds after the flame is removed and produces no dripping plastic particles that could ignite cotton wool located beneath the test specimen. The total afterburn time of five test specimens, each subjected to two flame exposures, is a maximum of 50 seconds.

[0147] V1: Unlike V0, the average maximum afterburn time here is less than 30 seconds, provided that no particles drip off and ignite the cotton wool. The total afterburn time for five test specimens, each flamed twice, is less than 250 seconds. V2: Unlike V0 and V1, this classification produces dripping plastic particles that ignite the cotton wool. Individual afterburn times are less than 30 seconds, and the total afterburn time for five test specimens, each flamed twice, is less than 250 seconds.

[0148] nb:The test does not provide a flame protection classification if the afterburn times are exceeded. Heat resistance:

[0149] The heat resistance of the compositions was determined using the Vicat softening temperature (method B, test force 50N, heating rate 50 K / h) on test specimens with dimensions of 80 mm x 10 mm x 4 mm according to ISO 306:2014-3. 2. Preparation of the test specimens

[0150] The compounds were produced on a 25 mm twin-screw extruder from Coperion with a throughput of 20 kg / h. The polymer melt temperatures in the extruder ranged between 260 and 280°C at an average screw speed of 225 rpm.

[0151] The test specimens with dimensions of 60 mm x 40 mm x 4 mm were produced from the molding compounds using standard injection molding processes at a melt temperature of 280°C and a tool temperature of 80°C. 3. Results

[0152] In the following tables, "ng" means "not tested" and "nb" means "failed". The asterisk "*" means "taken from UL Yellow Card". Table 1: UHMWPE without flame retardant component V-1 V-2 V-3 V-4 V-5 V-6 A-1 % by weight 100 94 93 92 91 90 A-2 Weight % 5 5 5 5 5 B-1 % by weight 0 1,0 2,0 3,0 4,0 5,0 CTI V 250 200 200 600 600 300 UL94 1.5 mm, 7d V2* ng ng ng ng ng 2 mm, 7d V2* ng ng ng ng ng 3 mm, 7d ng ng ng ng ng ng Vicat temperature °C 144 144 144 144 144 143 Note: V-9 with BDP only achieves UL94-V2, meaning no better results can be expected with V-1 to V-6.

[0153] Table 1 shows compositions consisting of polycarbonate and varying amounts of ultra-high molecular weight polyethylene (UHMWPE). The results of the CTI tests show that the tracking resistance of polycarbonate can be significantly improved to 600 V by adding 3 and 4 wt% UHMWPE (examples V-4, V-5). 2.0 wt% or less PE has a rather negative, or at best no, effect on the CTI value (V-1, V-2, V-3). It is noticeable that larger amounts of PE also lead to a worse CTI value, clearly indicating that there is a certain optimal range for PC / PE compositions where the PE content must be neither too low nor too high to achieve a CTI of 600 V. However, the following results must also be considered, as the phosphorus-containing flame retardant also has an influence.Within a fairly narrow range, the addition of PE has no negative effect on the Vicat softening temperature of the polycarbonate. Table 2: UHMWPE with flame retardant component E-7 E-8 V-9 V-10 E-11 E-12 E-13 V-14 V-15 A-1 % by weight 86,4 86,9 86,4 85,9 86,5 85,4 85,9 87,4 87,9 A-2 Weight % 5 5 5 5 5 5 5 5 5 E-1 % by weight 0,5 0,5 0,5 0,5 0,5 0,5 0,5 0,5 E-2 % by weight 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 B-1 % by weight 3,0 3,0 4,0 4,0 4,0 4,0 4,0 6,0 6,0 C-1 % by weight 4,0 4,0 4,0 4,0 4,0 4,0 4,0 D-1 % by weight 1,0 0,5 0,5 1,0 1,0 D-2 % by weight 0,5 0,5 0,5 CTI V 600 600 600 600 600 600 600 600 600 UL94 1.5 mm, 7d V0 V1 V2 V2 nb V1 V1 nb nb 2 mm, 7d V0 V0 V2 V2 V0 V0 V0 nb nb 3 mm, 7d V0 V0 nb nb V0 V0 V0 nb nb Vicat temperature °C 128 128 127 128 130 127 128 142 141

[0154] Table 2 shows polycarbonate compositions with UHMWPE in combination with BDP and PTFE. The results for each composition demonstrate the influence of flame retardants and anti-drip agents on both tracking resistance and fire behavior. Surprisingly, the addition of BDP to PC / PE mixtures does not automatically lower the CTI. However, a combination with PTFE or PTFE / SAN is always necessary to achieve the desired V0 flame classification according to UL94 (see V-9). Comparing the results of V-10 and E-13, it is noticeable that the fire behavior is slightly worsened by the addition of a mold release agent, and 0.5 wt% PTFE / SAN (50:50 mixture), i.e., 0.25 wt% PTFE, is insufficient as an anti-drip agent. In contrast, E-13, in which pure PTFE powder was added as an alternative composition, leads to a significant improvement in fire behavior.The same applies to E-12, which also contains 0.5 wt% PTFE (in a 50:50 masterbatch with SAN). It can therefore be concluded that a certain minimum concentration (here 0.5 wt%) of pure PTFE is necessary. Table 3: Concentration ranges of BDP and other PE component E-16 E-17 E-18 V-19 V-20 E-21 A-1 % by weight 83,9 83,9 83,4 82,4 78,4 85,9 A-2 Weight % 5 5 5 5 5 5 E-1 % by weight 0,5 0,5 0,5 0,5 0,5 0,5 B-1 % by weight 4,0 4,0 4,0 4,0 4,0 B-2 % by weight 4,0 C-1 % by weight 6,0 6,0 6,0 8,0 12,0 4,0 D-1 % by weight 0,5 1,0 D-2 % by weight 0,5 0,5 CTI V 600 600 600 300 275 600 UL94 1.5 mm, 7d V1 V1 V1 V2 V2 V0 2 mm, 7d V1 V0 V0 V2 V2 V0 3 mm, 7d V0 V0 V0 nb V2 V0 Vicat temperature °C 119 119 119 115 105 127 Note: "failed"

[0155] Table 3 shows the effect on CTI and flame retardancy when different concentrations of BDP are added. Concentrations ≥ 8 wt% BDP (see also Table 2) have a significantly negative impact on CTI and cannot achieve UL 94 V0 classification without an anti-drip agent (see V-19, V-20). The combination of 6 wt% BDP and 0.25 wt% PTFE (in the masterbatch, E-16) provides the desired high CTI as well as a V0 classification. To ensure sufficient V0 classification even in thinner wall thicknesses, higher PTFE concentrations of ≥ 0.5 wt% PTFE (E-17), also in the form of masterbatch D-1, in combination with 6 wt% BDP (E-18) must be used. In principle, materials with a CTI of 600V and a V0 classification at 2 mm can be obtained just as well with HDPE, in combination with BDP and PTFE as with UHMWPE (see E-21). Table 4: UHMWPE / PE with phosphazene component V-22 E-23 E-24 V-25 V-26 E-27 A-1 % by weight 86,4 85,4 85,9 77,4 73,4 85,9 A-2 Weight % 5 5 5 10 10 5 E-1 % by weight 0,5 0,5 0,5 0,5 0,5 0,5 E-2 % by weight 0,1 0,1 0,1 0,1 0,1 0,1 B-1 % by weight 4,0 4,0 4,0 4,0 4,0 B-2 % by weight 4,0 C-2 % by weight 4,0 4,0 4,0 8,0 12,0 4,0 D-1 % by weight 1,0 D-2 % by weight 0,5 0,5 CTI V 300 600 600 275 225 600 UL94 1.5 mm, 7d V2 V1 V1 V2 V2 V0 2 mm, 7d V2 V0 V0 V2 V2 V0 3 mm, 7d nb V0 V0 V2 V2 V0 Vicat temperature °C 131 131 132 122 111 132

[0156] Table 4 shows the influence on CTI and flame retardancy upon the addition of different concentrations of phosphazene. Similar to the compositions with BDP, mixtures with higher concentrations of phosphazene also exhibit a significantly lower CTI. The values ​​are even lower than those of BDP-additized compositions (see V-25, V-26). It is noteworthy that, unlike with BDP, a mixture without PTFE never achieves a CTI of 600 V when using phosphazene (see V-22). A minimum of 0.5 wt% pure PTFE is required to achieve both the CTI and the flame retardancy (V0) (see E-24), with the 50:50 mixture with SAN performing equally well (E-23). ​​As shown above, equally good properties can be achieved with HDPE instead of UHMWPE (E-27). Table 5: UHMWPE with C4 salt component V-28 V-29 V-30 A-1 % by weight 90,35 90,31 85,9 A-2 Weight % 5 5 5 E-1 % by weight 0,5 0,5 0,5 E-2 % by weight 0,1 0,1 0,1 B-1 % by weight 4,0 4,0 4,0 Cx % by weight 0,05 0,09 0,05 C-1 % by weight 4,0 D-1 % by weight 0,5 CTI V 600 225 200 UL94 1.5 mm, 7d nb nb nb 2 mm, 7d nb nb V0 3 mm, 7d V2 V2 V0 Vicat temperature °C 141 141 128

[0157] The results in Table 5 show that the use of metal sulfonates (C4 salt, Cx) as flame retardants has a significantly greater effect on tracking resistance than the addition of BDP. While very low concentrations have no negative impact on the CTI (example V-28), concentrations as low as 0.09 wt% already result in a decrease in the CTI to 225 V (V-29), below the tracking resistance of pure bisphenol A-based polycarbonate. Although the UL 94 V0 classification at 2 mm can be achieved by adding BDP, the CTI value remains at a low level (V-30).

Claims

1. Thermoplastic composition, containing A) at least 70% by weight of aromatic polycarbonate, B) > 2.0% by weight to 6.0% by weight of polyethylene, C) 2.5% by weight to < 8.0% by weight of phosphorus-containing flame retardant, D) 0.2% by weight to 2.0% by weight of fluorine-containing anti-drip agent, wherein the composition is free of flame retardants selected from the group of alkali metal, alkaline earth metal or ammonium salts of aliphatic or aromatic sulfonic acid, sulfonamide or sulfonimide derivatives, and wherein, if the composition contains > 4.0% by weight of polyethylene, at least 0.5% by weight of fluorine-containing anti-drip agent is present, and wherein the % by weight figures are based on the overall composition.

2. Thermoplastic composition according to Claim 1, wherein the polyethylene is an HDPE, an HMWPE, a UHMWPE, or a mixture of these.

3. Thermoplastic composition according to Claim 1 or 2, wherein the phosphorus-containing flame retardant is an organophosphate, a phosphazene or a mixture of these.

4. Thermoplastic composition according to any of the preceding claims, wherein, as phosphorus-containing flame retardant, an organophosphate of formula (11) is present in which R1, R2, R3 and R4 are each independently a linear or branched C1- to C8-alkyl radical and / or optionally linear- or branched-alkyl-substituted C5- to C6-cycloalkyl radical, C6- to C10-aryl radical or C7- to C12-aralkyl radical, n is independently 0 or 1, q is independently 0, 1, 2, 3 or 4, N is a number between 1 and 30, R5 and R6 are independently linear or branched C1- to C4-alkyl radical, preferably methyl radical, and Y is linear or branched C1- to C7-alkylidene, a linear or branched C1- to C7-alkylene radical, C5- to C12-cycloalkylene radical, C5- to C12-cycloalkylidene radical, -O-, -S-, -SO-, SO2 or -CO-.

5. Thermoplastic composition according to any of the preceding claims, wherein, as phosphorus-containing flame retardant, phosphazene of formula (13g) is present where k = 1, 2 or 3, including mixtures thereof.

6. Thermoplastic composition according to any of the preceding claims, containing 3% to 6% by weight of phosphorus-containing flame retardant.

7. Thermoplastic composition according to any of the preceding claims, wherein as further additive mould-release agent is present, as fluorine-containing anti-drip agent PTFE is present, and the amount of PTFE is at least 0.5% by weight.

8. Thermoplastic composition according to any of the preceding claims, containing 3% to 4% by weight of polyethylene.

9. Thermoplastic composition according to any of the preceding claims, containing up to 1.0% by weight of fluorine-containing anti-drip agent.

10. Thermoplastic composition according to any of the preceding claims, consisting of A) at least 70% by weight of aromatic polycarbonate, B) > 2.0% by weight to 6.0% by weight of polyethylene, C) 2.5% by weight to < 8.0% by weight of phosphorus-containing flame retardant, D) 0.2% by weight to 2.0% by weight of fluorine-containing anti-drip agent, wherein, if the composition contains > 4.0% by weight of polyethylene, at least 0.5% by weight of fluorine-containing anti-drip agent is present, E) 0% to 5% by weight of one or more further additive(s), selected from the group consisting of heat stabilizers, antioxidants, mould-release agents, UV absorbers, IR absorbers, antistats, flame retardants different from component C, excluding alkali metal, alkaline earth metal or ammonium salts of aliphatic or aromatic sulfonic acid, sulfonamide or sulfonimide derivatives, optical brighteners, light-scattering agents, hydrolysis stabilizers, transesterification stabilizers, organic dyes, organic pigments, inorganic pigments, compatibilizers, flow improvers, additives for laser marking, and mixtures thereof.

11. Moulding consisting of, or comprising a region made from, a thermoplastic composition according to any of the preceding claims.

12. Moulding according to Claim 11, wherein the moulding is part of a high-voltage switch, inverter, relay, electronic connector, electrical connector, circuit breaker, a photovoltaic system, an electric motor, a heat sink, a charger or charging plug for electric vehicles, an electrical junction box, a smart meter housing, a miniature circuit breaker, a busbar.

13. Use of > 2.0% by weight to 6.0% by weight of polyethylene, 2.5% to < 8.0% by weight of phosphorus-containing flame retardant and 0.2% to 2.0% by weight of fluorine-containing anti-drip agent, wherein, if the composition contains > 4.0% by weight of polyethylene, at least 0.5% by weight of fluorine-containing anti-drip agent is present, and wherein the % by weight figures are based on the resulting overall composition, for attaining a CTI of 600 V and a UL94 V0 classification at 3 mm in a thermoplastic composition containing at least 70% by weight of aromatic polycarbonate.

14. EE component, comprising a first electrical conductor and a second electrical conductor at a first distance d1 and a second distance d2 with respect to one another, which are connected with each other via a thermoplastic composition according to any of Claims 1 to 10, which is in direct contact with the first electrical conductor and the second wherein the distance d1 is the shortest distance between the first electrical conductor and the second electrical conductor along the surface of the thermoplastic composition and wherein the distance d2 is the shortest distance between the first electrical conductor and the second electrical conductor through the air, wherein d2 is selected in such a way that at the respective operating voltage a sparkover through the air is prevented and wherein d1, at the operating voltage U listed below, is: d1i(0 V ≤ U ≤ 250 V): 1.3 mm to < 2.5 mm d1ii(250 V < U ≤ 500 V) = 2.5 mm to < 5.0 mm d1iii(500 V < U ≤ 1000 V) = 5.0 mm to < 10.0 mm.

15. Thermoplastic composition according to any of Claims 1 to 10 or use according to Claim 13, wherein the aromatic polycarbonate is bisphenol A-based homopolycarbonate.