E / E COMPONENT CONTAINING POLYCARBONATE MATERIAL WITH HIGH TRACE RESISTANCE

Description

[0001] The present invention relates to an E / E component containing a flame-retardant polycarbonate composition with high tracking resistance and to the use of a specific combination of rubber-modified graft polymer and a flame retardant for improving tracking resistance and flame retardancy of polycarbonate compositions.

[0002] Polycarbonate compositions as well as polycarbonate blends are used for a wide range of applications in the automotive, construction and electrical / electronic (E / E) sectors.

[0003] For applications in the electrical / electronic (E / E) sector, good insulation properties and high flame resistance are of great safety relevance. Such requirements are also becoming increasingly important in the field of electromobility, for example. If the thermoplastic material (i.e. the polymer material) is in direct contact with current-carrying parts such as conductor tracks, high tracking resistance is also important. Otherwise, tracking currents can cause charge to be transferred via the plastic surface over longer distances than would be possible directly through the air at the same voltage. This is even the case with materials that actually have high insulation properties, such as plastics. The tendency towards tracking current formation should therefore be as low as possible in order to reduce the risk of short circuits and thus avoid fires. In addition, high tracking resistance makes it possible to increase the distances between, for example,to reduce electrical conductor tracks and thus achieve smaller component sizes or to operate the components with higher operating voltages.

[0004] A measure of a plastic's tracking resistance is the CTI ("comparative tracking index"). This expresses the extent to which the plastic surface allows for the formation of tracking currents due to the influence of dirt or liquid when an electrical voltage is applied. The higher the tracking resistance, the better the material is suited for components subject to high voltages and / or that may become dirty or come into contact with moisture during use. The CTI is expressed in volts and indicates that up to this voltage, no significant tracking current occurs when a certain amount of electrolyte solution is dripped onto the surface.

[0005] An alternative method for measuring tracking resistance is the PTI ("Proof Tracking Index"), described in the example section. This method can be used particularly for characterizing components to test the tracking resistance of the component at voltage ranges known to be critical.

[0006] Compared to other polymers such as polyethylene, polycarbonate has only a low tracking resistance with a CTI value of approximately 250 V. However, for some high-voltage applications, such as in the field of electromobility, CTI values ​​of 600 V are required. Furthermore, the materials for such applications should have very high flame retardancy according to UL 94 V, preferably a classification of VO for thin wall thicknesses such as 1.5 mm.

[0007] The flame resistance of polycarbonate and polycarbonate blends is typically improved by the addition of flame retardants. However, some flame retardants increase the tendency for current tracking, thus leading to an undesirable reduction in the CTI. Furthermore, flame retardants often negatively affect heat resistance and toughness, such as impact strength.

[0008] For the reasons mentioned above, E / E components made of polycarbonate composites, a thermoplastic material, are difficult to realize. While it is generally possible to increase the spacing between the conductor tracks to such an extent that the risk of short circuits and fires caused by leakage currents is largely eliminated, as mentioned above, such an approach runs counter to the goal of producing the smallest possible components and using them in the corresponding applications.

[0009] Therefore, some publications have described approaches to provide polycarbonate compositions with improved CTI.

[0010] EP 3560997 A2 discloses a thermoplastic resin composition having good properties such as high CTI comprising: (A) 100 parts by weight of polycarbonate; (B) 2 parts by weight to 6 parts by weight of a cyclic phosphazene compound flame retardant; (C) 0.1 part by weight to 5 parts by weight of an impact modifier; and (D) 1 part by weight to 3 parts by weight of a fluorinated polyolefin.

[0011] US 2012 / 0248384 A1 discloses polycarbonate compositions, processes, and articles of manufacture that meet at least certain electrical tracking resistance requirements. The compositions, processes, and articles of manufacture that meet these requirements contain at least one polycarbonate, a polysiloxane block copolycarbonate, and a transition metal oxide, e.g., titanium dioxide.

[0012] US2018 / 187003A1 discloses a thermoplastic material comprising aromatic polycarbonate, rubber-modified graft copolymer and phosphorus-containing flame retardant.

[0013] The relationships between fire behavior (GWFI) and tracking resistance are discussed in the publication: "Glow wire ignition temperature (GWIT) and comparative tracking index (CTI) of glass fiber filled engineering polymers, blends and flame retarded formulations" (Polymer Degradation and Stability, Volume 96, Issue 12, December 2011, pages 2098-2103).

[0014] Since it is difficult to provide E / E components with the necessary flame retardancy and high CTI from polycarbonate compositions, other thermoplastic materials such as polyester or polyamide are often used for such applications. However, polycarbonate and polycarbonate blend compositions offer an attractive combination of high heat resistance and high toughness, and therefore, it was desirable to provide E / E components comprising a thermoplastic material with such properties without undesirably increasing the spacing between the electrical conductors.

[0015] It was particularly desirable to provide an E / E component comprising a thermoplastic material characterized by the combination of high CTI, high flame retardancy, high heat resistance and impact strength. In particular, it was desirable that the thermoplastic material, preferably made of a polycarbonate composition, has a CTI of at least 400 V, preferably 600 V, preferably determined according to the rapid test method described in the example section based on IEC 60112:2009, a PTI of 300 V and 350 V, preferably determined according to the rapid test method described in the example section based on IEC 60112:2009, a UL 94 classification of at least V2 at 1.5 mm, a Vicat softening temperature measured according to DIN ISO 306 (version of 2013, method B / 120) of at least 105 °C and an Izod notched impact strength of at least 40 kJ / m2 according to ISO 180-1A (version of 2019).

[0016] Surprisingly, it was found that an E / E component comprising a first electrical conductor L1 and a second electrical conductor L2 at a first distance d1 and a second distance d2 from each other, which are connected via a thermoplastic material M 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 thermoplastic material M 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 flashover through the air is prevented at the respective operating voltage U for the component, wherein d1 has the following values ​​for the operating voltage U listed below: d 1 0 V ≤ U ≤ 250 V : 1,3 mm bis < 2 , 5 mm d 1 250 V < U ≤ 500 V : 2,5 mm bis < 5 , 0 mm d 1 500 V < U ≤ 1000 V = 5,0 mm bis < 10 , 0 mm and wherein the thermoplastic material M comprises the following components: A) at least one aromatic polycarbonate, aromatic polyester carbonate or mixtures thereof, B) at least 5% by weight of at least one rubber-modified graft polymer with a graft base selected from the group consisting of acrylate rubbers, polybutadiene rubbers and styrene-butadiene block copolymer rubbers and a graft layer which is free of structural units derived from acrylonitrile C) at least 5% by weight of at least one phosphorus-containing flame retardant. has the desired properties.

[0017] Components A, B and C and optionally D therefore form the composition of the thermoplastic material M.

[0018] The thermoplastic material M (i.e. the composition) preferably comprises 50 to 85 wt.%, more preferably 65 to 80 wt.% of component A, 5 to 15 wt.%, more preferably 6 to 12 wt.% of component B and 5 to 15 wt.%, more preferably 6 to 12 wt.% of component C.

[0019] In a preferred embodiment, the weight ratio of components B to C is 0.8:1 to 1.2:1.

[0020] In addition to components A, B and C, the composition may contain as component D one or more polymer additives, fillers and reinforcing materials, dyes, pigments and / or polymers different from components A and B as blend partners, the amount of component D preferably being 0.1 to 20% by weight, more preferably 0.2 to 15% by weight.

[0021] The proportions of components A to D each refer to the total composition.

[0022] Preferably, the composition consists of at least 90% by weight, more preferably at least 95% by weight, of components A to D. Particularly preferably, the composition consists only of components A to D.

[0023] The conductor spacing d1 therefore depends on the operating voltage and is, for example, 1.3 to less than 2.5 mm in the range from 0 to 250 V inclusive.

[0024] The stated lower limits of the conductor spacing are only feasible if the thermoplastic material has a CTI of 600 V. For the stated upper limits, a CTI of at least 400 V is required. If the thermoplastic material has a CTI of 600 V, the distances d1 are preferably as follows: d 1 0 V ≤ U ≤ 250 V : 1,3 bis < 1 , 8 mm d 1 250 V < U ≤ 500 V : 2,5 bis < 3 , 6 mm d 1 500 V < U ≤ 1000 V : 5,0 bis < 7 , 1 mm

[0025] For the E / E component according to the invention, d2 is preferably at least 1.2 mm, more preferably 1.2 to 10.0 mm. The determination of the distance at which arcing through the air is prevented is within the skill of the person skilled in the art.

[0026] Preferably, the E / E component is one that has a protection class of IP6K9K according to ISO 20653:2013-02, i.e. shielding against contact, ingress of foreign bodies and water.

[0027] The E / E component according to the invention is preferably a part of a (high-)voltage switch or (high-)voltage inverter, relay, electronic connector, electrical connector, circuit breaker, photovoltaic system, electric motor, heat sink, USB connector, charger or charging connector for electric vehicles, electrical junction box, smart meter housing, miniature circuit breaker, or busbar. "Part of" here means that it can be an individual element of a complex product, a component group, but it can also be the entire element, as is conceivable, for example, in the case of an "electronic connector."

[0028] A further subject of the present invention is also an assembly which is designed for an operating voltage of at least 400 V, preferably 600 V, containing the E / E component according to the invention, preferably such an assembly which has a protection class of IP6K9K according to ISO 20653:2013-02,

[0029] Another object of the present invention is the use of 5 to 15 wt. % of a rubber-modified graft polymer with a graft base selected from the group consisting of acrylate rubbers, polybutadiene rubbers and styrene-butadiene block copolymer rubbers and a graft layer which is free of structural units derived from acrylonitrile and 5 to 15 wt. % of at least one phosphorus-containing flame retardant to improve the CTI and the flame retardancy according to UL 94 V of aromatic polycarbonate compositions or aromatic polyestercarbonate compositions.

[0030] Preferred is a use in which a CTI of 600 V determined according to the rapid test method based on IEC 60112:2009 and a UL 94 V classification with a specimen thickness of 1.5 mm of at least V2 of polycarbonate compositions containing 50 to 85 wt.% aromatic polycarbonate or aromatic polyester carbonate is achieved.

[0031] The features mentioned as preferred, particularly preferred, etc. for the composition of the thermoplastic material also apply with regard to the use according to the invention Component A

[0032] Aromatic polycarbonates and / or aromatic polyestercarbonates according to component A which are suitable according to the invention are known from the literature or can be prepared by processes known from the literature (for the preparation of aromatic polycarbonates see, for example, Schnell, "Chemistry and Physics of Polycarbonates", Interscience Publishers, 1964 and DE-AS 1 495 626, DE-A 2 232 877, DE-A 2 703 376, DE-A 2 714 544, DE-A 3 000 610, DE-A 3 832 396; for the preparation of aromatic polyestercarbonates, e.g. DE-A 3 007 934).

[0033] Aromatic polycarbonates are produced, for example, by reacting diphenols with carbonic acid halides, preferably phosgene, and / or with aromatic dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalides, by the interfacial process, optionally using chain terminators, for example monophenols, and optionally using trifunctional or more than trifunctional branching agents, for example triphenols or tetraphenols. Production via a melt polymerization process by reacting diphenols with, for example, diphenyl carbonate is also possible.

[0034] Diphenols for the preparation of the aromatic polycarbonates and / or aromatic polyester carbonates are preferably those of the formula (1) where A is a single bond, C 1 to C 5 alkylene, C 2 to C 5 alkylidene, C 5 to C 6 cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO 2 -, C 6 to C 12 arylene, to which further aromatic rings optionally containing heteroatoms may be condensed, or a radical of the formula (2) or (3) B is each C 1 to C 12 alkyl, preferably methyl, halogen, preferably chlorine and / or bromine, x is each independently 0, 1 or 2, p is 1 or 0, and R 5< and R 6< for each X 1< can be selected individually, independently of one another are hydrogen or C 1 to C 6 alkyl, preferably hydrogen, methyl or ethyl, X1 is carbon and m is an integer from 4 to 7, preferably 4 or 5, with the proviso that on at least one atom X 1<, R 5< and R 6< are simultaneously alkyl.

[0035] Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis(hydroxyphenyl)C1-C5-alkanes, bis(hydroxyphenyl)C5-C6-cycloalkanes, bis(hydroxyphenyl)ethers, bis(hydroxyphenyl)sulfoxides, bis(hydroxyphenyl)ketones, bis(hydroxyphenyl)sulfones and α,α-bis(hydroxyphenyl)diisopropylbenzenes and their nuclear-brominated and / or nuclear-chlorinated derivatives.

[0036] Particularly preferred diphenols are 4,4'-dihydroxydiphenyl, bisphenol A, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfone, and their di- and tetrabrominated or chlorinated derivatives, such as 2,2-bis(3-chloro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, or 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane. 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) is particularly preferred.

[0037] The diphenols can be used individually or as any mixture. The diphenols are known from the literature or are available by known methods.

[0038] Chain terminators suitable for the production of thermoplastic, aromatic polycarbonates are, for example, phenol, p-chlorophenol, p-tert-butylphenol or 2,4,6-tribromophenol, but also long-chain alkylphenols, such as 4-[2-(2,4,4-trimethylpentyl)]-phenol, 4-(1,3-tetramethylbutyl)-phenol according to DE-A 2 842 005 or monoalkylphenol or dialkylphenols with a total of 8 to 20 carbon atoms in the alkyl substituents, such as 3,5-di-tert-butylphenol, p-iso-octylphenol, p-tert-octylphenol, p-dodecylphenol and 2-(3,5-dimethylheptyl)-phenol and 4-(3,5-dimethylheptyl)-phenol. The amount of chain terminators to be used is generally between 0.5 mol% and 10 mol%, based on the molar sum of the diphenols used.

[0039] The thermoplastic, aromatic polycarbonates have average molecular weights (weight average M w ) of preferably 20,000 to 40,000 g / mol, more preferably 22,000 to 32,000 g / mol, particularly preferably 24,000 to 30,000 g / mol. Measured by GPC (gel permeation chromatography) calibrated against bisphenol A polycarbonate standards using dichloromethane as 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 (from 2009 in German) from Currenta GmbH & Co. OHG, Leverkusen. The eluent is dichloromethane. Column combination of cross-linked styrene-divinylbenzene resins. Diameter of the analytical columns: 7.5 mm; Length: 300 mm. Column material particle size: 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.

[0040] The preferred ranges achieve a particularly advantageous balance of mechanical and rheological properties in the compositions according to the invention.

[0041] The thermoplastic, aromatic polycarbonates can be branched in a known manner, preferably by incorporating 0.05 to 2.0 mol%, based on the total of the diphenols used, of trifunctional or more than trifunctional compounds, for example those with three or more phenolic groups. Linear polycarbonates, more preferably based on bisphenol A, are preferred.

[0042] Both homopolycarbonates and copolycarbonates are suitable. For the preparation of inventive copolycarbonates according to component A, 1 to 25 wt. %, preferably 2.5 to 25 wt. %, based on the total amount of diphenols to be used, of polydiorganosiloxanes with hydroxyaryloxy end groups can also be used. These are known (US Pat. No. 3,419,634) and can be prepared by processes known from the literature. Polydiorganosiloxane-containing copolycarbonates are also suitable; the preparation of polydiorganosiloxane-containing copolycarbonates is described, for example, in DE-A 3,334,782.

[0043] Aromatic dicarboxylic acid dihalides for the production of aromatic polyester carbonates are preferably the diacid dichlorides of isophthalic acid, terephthalic acid, diphenyl ether-4,4'-dicarboxylic acid and naphthalene-2,6-dicarboxylic acid.

[0044] Particularly preferred are mixtures of the diacid dichlorides of isophthalic acid and terephthalic acid in a ratio between 1:20 and 20:1.

[0045] In the production of polyester carbonates, a carbonic acid halide, preferably phosgene, is also used as a bifunctional acid derivative.

[0046] In addition to the monophenols already mentioned, suitable chain terminators for the production of aromatic polyester carbonates are their chlorocarbonic acid esters and the acid chlorides of aromatic monocarboxylic acids, which may optionally be substituted by C 1 to C 22 alkyl groups or by halogen atoms, as well as aliphatic C 2 to C 22 monocarboxylic acid chlorides.

[0047] The amount of chain terminators is 0.1 to 10 mol%, based on moles of diphenol in the case of phenolic chain terminators and on moles of dicarboxylic acid dichloride in the case of monocarboxylic acid chloride chain terminators.

[0048] In the production of aromatic polyester carbonates, one or more aromatic hydroxycarboxylic acids can additionally be used.

[0049] The aromatic polyester carbonates can be either linear or branched in a known manner (see DE-A 2 940 024 and DE-A 3 007 934), with linear polyester carbonates being preferred.

[0050] Branching agents which can be used are, for example, trifunctional or polyfunctional carboxylic acid chlorides, such as trimesic acid trichloride, cyanuric acid trichloride, 3,3'-,4,4'-benzophenonetetracarboxylic acid tetrachloride, 1,4,5,8-naphthalenetetracarboxylic acid tetrachloride or pyromellitic acid tetrachloride, in amounts of 0.01 to 1.0 mol% (based on the dicarboxylic acid dichlorides used) or trifunctional or polyfunctional phenols, such as phloroglucinol, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-hept-2-ene, 4,6-dimethyl-2,4-6-tri-(4-hydroxyphenyl)-heptane, 1,3,5-tri-(4-hydroxyphenyl)-benzene, 1,1,1-tri-(4-hydroxyphenyl)-ethane, tri-(4-hydroxyphenyl)-phenylmethane, 2,2-Bis[4,4-bis(4-hydroxy-phenyl)-cyclohexyl]-propane, 2,4-bis(4-hydroxyphenyl-isopropyl)-phenol, tetra-(4-hydroxyphenyl)-methane, 2,6-bis(2-hydroxy-5-methyl-benzyl)-4-methyl-phenol, 2-(4-Hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane, tetra-(4-[4-hydroxyphenyl-isopropyl]-phenoxy)-methane, 1,4-bis[4,4'-dihydroxytri-phenyl)-methyl]-benzene, in amounts of 0.01 to 1,0 mol% based on the diphenols used. Phenolic branching agents can be added with the diphenols; acid chloride branching agents can be added together with the acid dichlorides.

[0051] The proportion of carbonate structural units in the thermoplastic aromatic polyester carbonates can vary as desired. The proportion of carbonate groups is preferably up to 100 mol%, in particular up to 80 mol%, and particularly preferably up to 50 mol%, based on the sum of ester groups and carbonate groups. Both the ester and carbonate portions of the aromatic polyester carbonates can be present in the form of blocks or randomly distributed in the polycondensate.

[0052] The thermoplastic, aromatic polycarbonates and polyester carbonates can be used alone or in any mixture.

[0053] Linear polycarbonate, more preferably based exclusively on bisphenol A, is preferably used as component A. Component B

[0054] Component B is at least one rubber-containing graft polymer of, B.1) 5 to 95% by weight, preferably 10 to 70% by weight, particularly preferably 20 to 60% by weight, based on component B, of a mixture of B.1.1) 65 to 85% by weight, preferably 70 to 80% by weight, based on B.1, of at least one monomer selected from the group of vinylaromatics (such as, for example, styrene, α-methylstyrene), nuclear-substituted vinylaromatics (such as, for example, p-methylstyrene, p-chlorostyrene) and methacrylic acid (C1-C8) alkyl esters (such as, for example, methyl methacrylate, ethyl methacrylate) and B.1.2) 15 to 35% by weight, preferably 20 to 30% by weight, based on B.1, of at least one monomer selected from the group of (meth)acrylic acid (C1-C8) alkyl esters (such as, for example, methyl methacrylate, n-butyl acrylate, tert-butyl acrylate) and derivatives (such as anhydrides and imides) of unsaturated carboxylic acids (for example maleic anhydride and N-phenylmaleimide) to B.2) 95 to 5 wt.%, preferably 90 to 30 wt.%, particularly preferably 80 to 40 wt.-%, based on component B, of one or more rubber-elastic (elastomeric) graft bases selected from the group consisting of acrylate rubber and diene rubber. The graft base preferably has a glass transition temperature < 0°C, more preferably < -20°C, particularly preferably < -40°C.

[0055] Component B.1 is also called graft coating or graft shell and is free of acrylonitrile.

[0056] Unless expressly stated otherwise in this application, the glass transition temperature is determined for all components by means of differential scanning calorimetry (DSC) according to DIN EN 61006 (version of 1994) at a heating rate of 10 K / min with determination of the Tg as the midpoint temperature (tangent method).

[0057] The graft particles in component B1 preferably have an average particle size (D50 value) of 0.05 to 5 µm, preferably of 0.1 to 1.0 µm, particularly preferably of 0.2 to 0.5 µm.

[0058] The average particle size D50 is the diameter above and below which 50% by weight of the particles lie. Unless explicitly stated otherwise in this application, it is determined by ultracentrifuge measurement (W. Scholtan, H. Lange, Kolloid, Z. und Z. Polymere 250 (1972), 782-1796).

[0059] Preferred diene rubbers as grafting bases B.2 are those containing butadiene or copolymers of dienes, preferably containing butadiene, and further copolymerizable vinyl monomers (e.g. according to B.1.1 and B.1.2) or mixtures of one or more of the aforementioned components.

[0060] Further preferred as the dine rubber is pure polybutadiene rubber. In a further preferred embodiment, B.2 is styrene-butadiene rubber, particularly preferably styrene-butadiene block copolymer rubber.

[0061] Preferred monomers B.1.1 are selected from at least one of the monomers styrene, α-methylstyrene and methyl methacrylate, preferred monomers B.1.2 are selected from at least one of the monomers maleic anhydride and methyl methacrylate.

[0062] Particularly preferred monomers are B.1.1 styrene and B.1.2 methyl methacrylate. Both B.1.1 and B.1.2 methyl methacrylate are equally preferred.

[0063] Among the graft copolymers with diene rubbers as the graft base, preferred are graft copolymers in which methyl methacrylate or a mixture of methyl methacrylate and styrene is grafted onto a 1,3-butadiene-based graft base or onto a graft base consisting of a mixture of 1,3-butadiene and styrene, which are also referred to as MBS (methyl methacrylate-butadiene-styrene) rubbers.

[0064] Elastomeric acrylate rubber graft bases B.2 suitable for the graft polymers B are preferably polymers of alkyl acrylic esters, optionally with up to 40 wt. %, based on B.2, of other polymerizable, ethylenically unsaturated monomers. Preferred polymerizable acrylic esters include C 1 to C 8 alkyl esters, for example methyl, ethyl, butyl, n-octyl, and 2-ethylhexyl esters; haloalkyl esters, preferably halo-C 1 -C 8 alkyl esters, such as chloroethyl acrylate, and mixtures of these monomers.

[0065] For crosslinking, monomers with more than one polymerizable double bond can be copolymerized. Preferred examples of crosslinking monomers are esters of unsaturated monocarboxylic acids with 3 to 8 C atoms and unsaturated monohydric alcohols with 3 to 12 C atoms, or saturated polyols with 2 to 4 OH groups and 2 to 20 C atoms, such as ethylene glycol dimethacrylate and allyl methacrylate; polyunsaturated heterocyclic compounds such as trivinyl and triallyl cyanurate; polyfunctional vinyl compounds such as di- and trivinylbenzenes; and also triallyl phosphate and diallyl phthalate. Preferred crosslinking monomers are allyl methacrylate, ethylene glycol dimethacrylate, diallyl phthalate, and heterocyclic compounds containing at least three ethylenically unsaturated groups. Particularly preferred crosslinking monomers are the cyclic monomers triallyl cyanurate, triallyl isocyanurate, triacryloylhexahydro-s-triazine, triallylbenzenes.The amount of crosslinked monomers is preferably 0.02 to 5, in particular 0.05 to 2 wt.%, based on the graft base B.2. For cyclic crosslinking monomers having at least three ethylenically unsaturated groups, it is advantageous to limit the amount to less than 1 wt.% of the graft base B.2.

[0066] The gel content of the graft polymers is at least 40 wt.%, preferably at least 60 wt.%, particularly preferably at least 75 wt.% (measured in acetone).

[0067] Unless otherwise stated in the present invention, the gel content of the graft polymers is determined at 25°C as the fraction insoluble in acetone as solvent (M. Hoffmann, H. Krömer, R. Kuhn, Polymeranalytik I and II, Georg Thieme-Verlag, Stuttgart 1977).

[0068] The graft polymers B are usually produced by radical polymerization.

[0069] Particularly preferred polymers B are, for example, those polymers prepared by emulsion polymerization, as described, for example, in Ullmann, Encyclopedia of Technical Chemistry, Vol. 19 (1980), p. 280 ff.

[0070] After the polymerization reaction is complete, the graft polymers are precipitated from the aqueous phase, followed by an optional water wash. The final processing step is drying.

[0071] Due to the manufacturing process, the graft polymer B generally also includes free copolymer of B.1.1 and B.1.2, i.e. copolymer not chemically bound to the rubber base, which is characterized by the fact that it can be dissolved in suitable solvents (e.g. acetone).

[0072] Component B1 preferably contains a free copolymer of B.1.1 and B.1.2, which has a weight-average molecular weight (Mw), determined by gel permeation chromatography with polystyrene as standard, of preferably 30,000 to 200,000 g / mol, particularly preferably 40,000 to 150,000 g / mol. Component C

[0073] As component C in the composition according to the invention, a phosphorus-containing flame retardant is used, preferably selected from the groups of mono- and oligomeric phosphoric and phosphonic acid esters and phosphazenes, whereby mixtures of several compounds selected from one or more of these groups can also be used as flame retardants.

[0074] Preferred mono- and oligomeric phosphoric or phosphonic acid esters are phosphorus compounds of the general formula (4) wherein R 1< , R 2< , R 3< and R 4< , independently of one another, each optionally halogenated C 1 to C 8 alkyl, each optionally substituted by alkyl, preferably C 1 to C 4 alkyl, and / or halogen, preferably chlorine, bromine, substituted C 5 to C 6 cycloalkyl, C 6 to C 20 aryl or C 7 to C 12 aralkyl, n independently of one another, 0 or 1 q 0 to 30 and X is a mono- or polynuclear aromatic radical having 6 to 30 C atoms, or a linear or branched aliphatic radical having 2 to 30 C atoms, which may be OH-substituted and contain up to 8 ether bonds.

[0075] Preferably, R 1< , R 2< , R 3< and R 4< independently of one another represent C 1 to C 4 -alkyl, phenyl, naphthyl or phenyl-C 1 -C 4 -alkyl. The aromatic groups R 1< , R 2< , R 3< and R 4< can in turn be substituted by halogen and / or alkyl groups, preferably chlorine, bromine and / or C 1 to C 4 -alkyl. Particularly preferred aryl radicals are cresyl, phenyl, xylenyl, propylphenyl or butylphenyl and the corresponding brominated and chlorinated derivatives thereof. X in formula (4) preferably represents a mono- or polynuclear aromatic radical having 6 to 30 C atoms. This is preferably derived from diphenols. n in formula (4) can, independently of one another, be 0 or 1, preferably n is 1. q represents values ​​from 0 to 30. When using mixtures of different components of formula (4), mixtures can preferably have number-average q values ​​of 0.3 to 10, particularly preferably 0.5 to 10, in particular 1.05 to 1.4, most preferably 1.05 to 1.2. X particularly preferably represents or their chlorinated or brominated derivatives, in particular X is derived from resorcinol, hydroquinone, bisphenol A, or diphenylphenol. X is particularly preferably derived from bisphenol A.

[0076] Monophosphates (q=0), oligophosphates (q=1-30) or mixtures of mono- and oligophosphates can be used as component C according to the invention.

[0077] Monophosphorus compounds of the formula (1) are in particular tributyl phosphate, tris-(2-chloroethyl) phosphate, tris-(2,3-dibromopropyl) phosphate, tri-(2-ethylhexyl phosphate), triphenyl phosphate, tricresyl phosphate, diphenyl cresyl phosphate, diphenyl octyl phosphate, diphenyl 2-ethyl cresyl phosphate, tri-(isopropylphenyl) phosphate, halogen-substituted aryl phosphates, dimethyl methylphosphonate, diphenyl methylphosphenate, diethyl phenylphosphonate, triphenylphosphine oxide or tricresylphosphine oxide.

[0078] A particularly preferred phosphorus compound according to component C is bisphenol-A based oligophosphate according to formula (5).

[0079] The phosphorus compounds according to formula (4) are known (cf. e.g. EP-A 363 608, EP-A 640 655) or can be prepared analogously by known methods (e.g. Ullmanns Enzyklopädie der technischen Chemie, Vol. 18, p. 301 ff. 1979; Houben-Weyl, Methoden der organischen Chemie, Vol. 12 / 1, p. 43; Beilstein Vol. 6, p. 177).

[0080] The mean q values ​​can be determined by determining the composition of the phosphate mixture (molecular weight distribution) using a suitable method (gas chromatography (GC), high pressure liquid chromatography (HPLC), gel permeation chromatography (GPC)) and calculating the mean values ​​for q from this.

[0081] Phosphazenes are compounds of formulas (6) and (7) wherein R is in each case the same or different and represents amino, in each case optionally halogenated, preferably fluorine-halogenated C 1 to C 8 alkyl, or C 1 to C 8 alkoxy, in each case optionally substituted by alkyl, preferably C 1 to C 4 alkyl, and / or halogen, preferably chlorine and / or bromine, C 5 to C 6 cycloalkyl, C 6 to C 20 aryl, preferably phenyl or naphthyl, C 6 to C 20 aryloxy, preferably phenoxy, naphthyloxy, or C 7 to C 12 aralkyl, preferably phenyl-C 1 -C 4 alkyl, k represents 0 or a number from 1 to 15, preferably a number from 1 to 10.

[0082] Examples include propoxyphosphazene, phenoxyphosphazene, methylphenoxyphosphazene, aminophosphazene, and fluoroalkylphosphazenes. Phenoxyphosphazene is preferred.

[0083] The phosphazenes can be used alone or as a mixture. The radical R can always be the same, or two or more radicals in formulas (6) and (7) can be different. Phosphazenes and their preparation are described, for example, in EP-A 728 811, DE-A 1 961668, and WO 97 / 40092.

[0084] Preferably, a flame retardant according to formula (4), particularly preferably according to formula (5), is used as component C. Component D

[0085] As component D, the composition may optionally contain one or more representatives selected from the group consisting of polymer additives and polymeric blend partners.

[0086] The polymer additives or polymeric blend partners are preferably selected from the group consisting of anti-drip agents, flame retardant synergists, smoke inhibitors, lubricants and mold release agents, nucleating agents, antistatic agents, conductivity additives, stabilizers, flow promoters, fillers and reinforcing agents, phase compatibilizers, further polymeric components other than components A and B as well as dyes and pigments.

[0087] In a preferred embodiment, at least one polymer additive selected from the group consisting of lubricants and mold release agents and stabilizers is used as component D.

[0088] In a preferred embodiment, at least one representative selected from the group consisting of sterically hindered phenols, organic phosphites, phosphorous acid and organic or inorganic Brönsted acids is used as stabilizer.

[0089] In a preferred embodiment, fatty acid esters, particularly preferably fatty acid esters of pentaerythritol or glycerol, are used as lubricants and mold release agents.

[0090] The quantity and type of components D must of course be selected so that the flame retardancy and the CTI are not significantly impaired. Production of the thermoplastic material from the composition

[0091] The thermoplastic material M can be produced from the composition containing the components A, B and C according to the invention and optionally D.

[0092] The thermoplastic material M can be produced, for example, by mixing the respective components of the composition in a known manner and melt compounding and melt extruding them at temperatures of preferably 200°C to 320°C, particularly preferably 240°C to 300°C, very particularly preferably 260°C to 290°C in conventional units such as internal kneaders, extruders and twin-screw extruders.

[0093] This process is generally referred to as compounding in this application.

[0094] Thermoplastic material M is therefore understood to be the product obtained when the components of the composition are melt compounded and melt extruded.

[0095] The mixing of the individual components of the composition can be carried out in a known manner, both successively and simultaneously, at approximately 20 °C (room temperature) and at higher temperatures. This means that, for example, some of the components can be metered via the main feed of an extruder, and the remaining components can be added later in the compounding process via a side extruder. Manufacturing the E / E component according to the invention

[0096] A component according to the invention can be manufactured, for example, by injection molding with overmolding of metallic conductor tracks. Prefabricated metallic conductor tracks are fixed in the cavity of the injection mold. After the mold is closed, the conductor tracks are flooded with polymer melt under high pressure, forming a bond when cooled. After solidification and demolding, the finished component can be used.

[0097] An alternative is integrated plastic-to-metal injection molding (ICM). In this process, the finished component is manufactured in two steps. In the first step, the plastic component is manufactured with the conductor tracks that will later be filled. The finished plastic component is then transferred to a second cavity and filled with solder, which, when solidified, represents the conductor tracks.

[0098] Another alternative is the subsequent connection of an injection-molded component to the conductor tracks. This means that the plastic component is manufactured by injection molding and then assembled with the conductor in a subsequent step. The injection-molded component can be connected by applying additional energy during assembly. There are several methods for this. For example, the metal conductor can be heated to a high temperature so that it can be pressed into the plastic component. The conductor can also be connected directly to the plastic component using laser welding.

[0099] The component is preferably a part of a (high-)voltage switch, (high-)voltage inverter, relay, electronic connector, electrical connector, circuit breaker, photovoltaic system, electric motor, heat sink, USB connector, charger or charging connector for electric vehicles, electrical junction box, smart meter housing, miniature circuit breaker, or busbar. It is also possible for the component to be the entire element and not just a part of it. Examples Component A-1:

[0100] Linear polycarbonate based on bisphenol A with a weight-average molecular weight M w of 26000 g / mol (determined by GPC in methylene chloride with polycarbonate based on bisphenol A as standard). Component A-2:

[0101] Linear polycarbonate based on bisphenol A with a weight-average molecular weight M w of 20000 g / mol (determined by GPC in methylene chloride with polycarbonate based on bisphenol A as standard). Component B-1

[0102] Graft polymer of 23 wt% methyl methacrylate and 6 wt% styrene on 71 wt% polybutadiene rubber as graft base, produced by emulsion polymerization, Kane Ace™< M732, Kaneka, Japan Component B-2

[0103] Graft polymer of 40 parts by weight of methyl methacrylate on 60 parts by weight of poly-n-butyl acrylate rubber as graft base (average particle diameter d50 = 0.50 µm), produced by emulsion polymerization, Paraloid™< EXL-2300 (Dow, USA) Component B-3

[0104] Graft polymer of 43 parts by weight of a copolymer of styrene and acrylonitrile in a weight ratio of 73:27 on 57 parts by weight of a particulate crosslinked polybutadiene rubber as graft base, produced by emulsion polymerization. Component C

[0105] Bisphenol-A based oligophosphate according to the following structure (Chemtura Manufacturing UK Limited) Component D-1

[0106] Pentaerythritol tetrastearate, Loxiol ™< P 861 / 3.5 Special (Emery Oleochemicals GmbH, Düsseldorf, Germany). Component D-2

[0107] Irganox™< B900 (mixture of 80% Irgafos™< 168 (tris(2,4-di-tert-butylphenyl) phosphite) and 20% Irganox™< 1076 (2,6-di-tert-butyl-4-(octadecanoxycarbonylethyl)phenol); BASF (Ludwigshafen, Germany). Component D-3

[0108] ADS5000: Polytetrafluoroethylene (PTFE) preparation from IRPC Public Company Limited, Thailand consisting of 50 wt% PTFE contained in a SAN copolymer matrix. Production and testing of the molding compounds from the compositions

[0109] The components were mixed on a Coperion ZSK-26 Mc18 twin-screw extruder at a melt temperature of 250 °C - 280 °C. The molded bodies were produced on an Arburg 270 E injection molding machine at a melt temperature of 260 °C and a mold temperature of 70 °C.

[0110] The IZOD notched impact strength was determined at room temperature on test specimens measuring 80 mm x 10 mm x 4 mm according to ISO 180 / 1A (version of 2019).

[0111] The Vicat softening temperature was measured according to DIN ISO 306 (method B with 50 N load and a heating rate of 120 K / h, version of 2013) on a one-sided injection-molded test specimen of dimension 80x10x4 mm.

[0112] Flame retardancy was assessed according to UL94V on bars measuring 127 x 12.7 x 1.5 mm.

[0113] The tracking index (CTI) for the compositions described here was tested using the rapid test method based on IEC 60112:2009. A 0.1% ammonium chloride test solution (395 ohm*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 intervals of 30 s. A test voltage was applied between the electrodes, which varied over the course of 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 s) were applied per voltage, provided no tracking current > 0.5 A occurred for 2 s 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 was 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 passed with 50 drops without any leakage current or fire. This procedure determined the maximum possible voltage at which a composition could withstand 50 drops of the test solution without a leakage current occurring. Finally, four additional test specimens were tested at the determined maximum voltage for confirmation, each with 50 drops. This confirmed value is given in the examples as the CTI. A 100-drop value was not determined; therefore, the "rapid test method based on" the aforementioned standard.

[0114] The PTI ("proof tracking index") was tested based on IEC 60112:2009, modified as described below. For this purpose, a 0.1% ammonium chloride test solution (395 ohm*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 intervals of 30 seconds. In contrast to the CTI test, a fixed test voltage was applied between the electrodes during the PTI test, and a total of five test specimens were tested at the respective voltage. A maximum of 50 drops (one drop every 30 seconds) were applied per test specimen, provided no leakage current > 0.5 A for 2 seconds occurred or the specimen burned. The test is considered passed at the specified voltage if none of the tested specimens exhibited a leakage current > 0.5 A over 2 s or if the specimen burned.If a leakage current > 0.5 A occurs for 2 s or if the sample burns, the test is considered failed. Table 1: Results Components [wt%] V1 V2 V3 V4 5 6 7 A-1 79,2 77,2 75,9 73,2 69,2 65,2 61,2 A-2 17,5 17,5 17,5 17,5 17,5 17,5 17,5 B-1 1 2 2,6 4 6 8 10 C 1 2 2,7 4 6 8 10 D-1 (PETS) 0,4 0,4 0,4 0,4 0,4 0,4 0,4 D-2 (Irganox B900) 0,1 0,1 0,1 0,1 0,1 0,1 0,1 D-3 (ADS 5000) 0,8 0,8 0,8 0,8 0,8 0,8 0,8 Characteristics Tracking resistance CTI [V] 600 600 600 600 600 600 600 PTI 300 V b b b b b b b PTI 350 V nb b b b b b b Izod impact strength [kJ / m 2 ] 14 19 47 49 50 48 45 Flame retardancy according to UL94 V at 1.5 mm V0 nb nb nb V0 V0 V1 Vicat softening temperature [°C] 138 134 132 128 121 115 108 "b" means passed "nb" means failed

[0115] The data from Table 1 show that only with compositions 5, 6, and 7 according to the invention, both high tracking resistance (CTI and PTI) and good flame retardancy are achieved. Furthermore, the Izod impact strength and Vicat softening temperature reach the desired values. If the proportions of components B-1 and C are too low, flame retardancy is not achieved, the notched Izod impact strength is low, or the tracking resistance is inadequate (V1, V2, V3, and V4). Table 2: Results Components [wt%] V8 V9 V10 V11 12 13 14 A-1 79,2 77,2 75,9 73,2 69,2 65,2 61,2 A-2 17,5 17,5 17,5 17,5 17,5 17,5 17,5 B-2 1 2 2,6 4 6 8 10 C 1 2 2,7 4 6 8 10 D-1 (PETS) 0,4 0,4 0,4 0,4 0,4 0,4 0,4 D-2 (Irganox B900) 0,1 0,1 0,1 0,1 0,1 0,1 0,1 D-3 (ADS 5000) 0,8 0,8 0,8 0,8 0,8 0,8 0,8 Characteristics Tracking resistance CTI [V] 250 600 250 600 600 600 600 PTI 300 V nb nb nb b b b b PTI 350 V nb b nb nb b b b Izod impact strength [kJ / m 2 ] 13 20 41 55 55 55 55 Flame retardancy according to UL94 V at 1.5 mm V0 V0 V0 V2 V2 V1 V0 Vicat softening temperature [°C] 138 135 132 128 121 114 108 "b" means passed "nb" means failed

[0116] The data in Table 2 show that even with component B-2, compositions with the desired properties can only be achieved with the inventive proportions of components B-2 and C. At too low proportions, the tracking resistance (CTI and / or PTI) is insufficient (V8, V9, V10, and V11). Furthermore, the notched Izod impact strength does not reach the desired minimum value (V8 and V9). Table 3: Results Components [wt%] V15 V16 V17 V18 V19 V20 A-1 79,2 77,2 75,9 73,2 69,2 61,2 A-2 17,5 17,5 17,5 17,5 17,5 17,5 B-3 1 2 2,6 4 6 10 C 1 2 2,7 4 6 10 D-1 (PETS) 0,4 0,4 0,4 0,4 0,4 0,4 D-2 (Irganox B900) 0,1 0,1 0,1 0,1 0,1 0,1 D-3 (ADS 5000) 0,8 0,8 0,8 0,8 0,8 0,8 Characteristics Tracking resistance CTI [V] 600 600 300 600 600 300 PTI 300 V b b b b nb b PTI 350 V nb b nb nb nb nb Izod impact strength [kJ / m 2 ] 12 21 51 54 57 54 Flame retardancy according to UL94 V at 1.5 mm V0 V0 V0 V0 V0 V0 Vicat softening temperature [°C] 138 134 132 128 121 108 "b" means passed "nb" means failed

[0117] The data in Table 3 show that with the use of non-inventive component B-3, satisfactory tracking resistance (PTI) is not achieved, except for V16, even at levels sufficient with components B-1 or B-2. Furthermore, with small amounts of component B-3, the notched Izod impact strength is very low (V15 and V16).

Claims

1. E / E component comprising a first electrical conductor L1 and a second electrical conductor L2 at a first distance d1 and a second distance d2 to one another, which are connected via a thermoplastic material M 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 thermoplastic material M 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 U for the component a sparkover through the air is prevented, wherein d1, at the operating voltage U listed below, has the following values: d 1 0 V ≤ U ≤ 250 V : 1.3 mm to < 2.5 mm d 1 250 V < U ≤ 500 V : 2.5 mm to < 5.0 mm d 1 500 V < U ≤ 1000 V : 5.0 mm to < 10.0 mm and wherein the thermoplastic material M comprises the following components: A) at least one aromatic polycarbonate, aromatic polyester carbonate or mixtures thereof, B) at least 5% by weight of at least one rubber-modified graft polymer having a graft substrate selected from the group consisting of acrylate rubbers, polybutadiene rubbers and styrene-butadiene block copolymer rubbers and a graft superstrate free from structural units derived from acrylonitrile C) at least 5% by weight of at least one phosphoruscontaining flame retardant.

2. E / E component according to Claim 1, wherein the thermoplastic material M comprises the following components: A) 50% to 85% by weight of at least one aromatic polycarbonate, aromatic polyester carbonate or mixtures thereof, B) 5% to 15% by weight of a rubber-modified graft polymer having a graft substrate selected from the group consisting of acrylate rubbers, polybutadiene rubbers and styrene-butadiene block copolymer rubbers and a graft superstrate free from structural units derived from acrylonitrile C) 5% to 15% by weight of at least one phosphoruscontaining flame retardant.

3. E / E component according to any of the preceding claims, wherein component A is bisphenol A-based homopolycarbonate.

4. E / E component according to any of the preceding claims, wherein component C is selected from the group consisting of mono- and oligomeric phosphoric and phosphonic esters, phosphazenes and mixtures of these compounds.

5. E / E component according to any of the preceding claims, wherein component C employed is a compound of general formula (4) wherein R1, R2, R3 and R4 are each independently optionally halogenated C1- to C8-alkyl, in each case optionally alkyl-substituted, preferably C1- to C4-alkyl-substituted, and / or halogen-substituted, preferably chlorine- or bromine-substituted, C5- to C6-cycloalkyl, C6- to C20-aryl or C7- to C12-aralkyl, n is independently 0 or 1, q is 0 to 30 and X is a mono- or polycyclic aromatic radical having 6 to 30 carbon atoms, or a linear or branched aliphatic radical having 2 to 30 carbon atoms, which may be OH-substituted and may contain up to 8 ether bonds.

6. E / E component according to any of the preceding claims, wherein the thermoplastic material M further comprises as component D 0.1% to 20% by weight of one or more polymer additives, fillers and reinforcers, dyes, pigments and / or polymers distinct from components A and B as blend partners.

7. E / E component according to any of the preceding claims, wherein d1 exhibits the following values at the operating voltages U listed below: d 1 0 V ≤ U ≤ 250 V : 1.3 to < 1.8 mm d 1 250 V < U ≤ 500 V : 2.5 to < 3.6 mm d 1 500 V < U ≤ 1000 V : 5.0 to < 7.1 mm .

8. E / E component according to any of the preceding claims, wherein d2 ≥ 1.2 mm.

9. E / E component according to any of the preceding claims, wherein d2 is 1.2 to 10.0 mm.

10. E / E component according to any of the preceding claims, wherein said component is a part of a (high-)voltage switch, (high-)voltage inverter, relay, electronic connector, electrical connector, circuit breaker, a photovoltaic system, an electric motor, a heat sink, a USB plug, a charger or charging plug for electric vehicles, an electrical junction box, a smart meter housing, a miniature circuit breaker or a busbar.

11. EE component according to any of the preceding claims, wherein the thermoplastic material M has a CTI of 600 V determined based on IEC 60112:2009 as described in the examples section.

12. EE assembly comprising an EE component according to any of the preceding claims, wherein the EE assembly has an IP6K9K protection rating according to ISO 20653:2013-02.

13. EE assembly according to Claim 12, wherein the operating voltage of the EE assembly is at least 400 V.

14. Use of 5% to 15% by weight of a rubber-modified graft polymer having a graft substrate selected from the group consisting of acrylate rubbers, polybutadiene rubbers and styrene-butadiene block copolymer rubbers and a graft superstrate free from structural units derived from acrylonitrile and 5% to 15% by weight of at least one phosphoruscontaining flame retardant for improving the CTI and the flame retardancy according to UL 94 V of aromatic polycarbonate compositions or aromatic polyester carbonate compositions.

15. Use according to Claim 14, wherein a CTI of 600 V determined based on IEC 60112:2009 as described in the examples section and a UL 94 V2 classification at a test specimen thickness of 1.5 mm of polycarbonate compositions containing 50% to 85% by weight of aromatic polycarbonate or aromatic polyester carbonate is attained.