POLYCARBONATE / POLYESTER COMPOSITION AND COMPONENT WITH HIGH LEAKAGE RESISTANCE

Description

[0001] The present invention relates to a flame-retardant polycarbonate / polyester composition, a component with high tracking resistance comprising the composition, and the use of a special polyester and a flame retardant to improve tracking resistance and flame retardancy in polycarbonate compositions.

[0002] Polycarbonates and polycarbonate blends have been used for many years in numerous applications, such as in automotive engineering, electronics, and the construction sector. Polycarbonates and polycarbonate blends are characterized by high heat resistance and high toughness. In particular, the overall property profile can be varied widely and adapted to specific requirements by selecting and adjusting the quantity of polymer blend partners.

[0003] For electronic applications, good insulation properties and high flame retardancy are of paramount importance for safety. Such requirements are becoming increasingly significant, for example, in the field of electromobility. If the polymer material is in direct contact with current-carrying components such as conductor tracks, high tracking resistance is also crucial. Otherwise, tracking currents can cause charge transfer across the plastic surface over greater distances than would be possible directly through air at the same voltage. This is even the case with materials that inherently possess high insulating properties, such as plastics. Therefore, the tendency to generate tracking currents should be minimized to reduce the risk of short circuits and thus prevent fires. Furthermore, high tracking resistance allows for greater 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 index expresses the extent to which the plastic surface, when exposed to dirt or liquid, allows tracking currents to form when an electrical voltage is applied. The higher the tracking resistance, the better suited the material is for components subjected to high voltages and / or those that may become contaminated or come into contact with moisture during operation. 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 applied.

[0005] Compared to other polymers such as polyethylene, polycarbonate exhibits only 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, materials for such applications should possess very high flame retardancy according to UL 94 V, preferably a classification of VO for thin wall thicknesses such as 1.5 mm.

[0006] The flame retardancy of polycarbonate and polycarbonate blends is usually improved by the addition of flame retardants.

[0007] US 2007 / 197722 A1 discloses a thermoplastic molding compound with improved impact and flame resistance. The composition includes (a) aromatic polycarbonate, (b) thermoplastic polyester, (c) halogenated acrylate, (d) an impact modifier, (e) a phosphorus-containing compound, and (f) fluorinated polyolefin.

[0008] US 2012 / 231278 discloses compositions with improved flame retardancy for extrusion applications containing aromatic polycarbonate, an acrylate-based spreading additive, a brominated flame retardant and a phosphorus-based flame retardant.

[0009] However, some flame retardants increase the tendency for leakage currents to form, thus leading to an undesirable decrease in CTI. Furthermore, flame retardants often negatively affect heat resistance and toughness, such as impact strength.

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

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

[0012] 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 fibre filled engineering polymers, blends and flame retarded formulations" (Polymer Degradation and Stability, Volume 96, Issue 12, December 2011, pages 2098-2103).

[0013] It was also desirable to provide polycarbonate compositions from which molded parts could be produced that exhibited a combination of high CTI, high flame retardancy, high heat resistance, and toughness. In particular, it was desirable that the molded parts have a CTI of 600 V, preferably determined according to the rapid test method described in the example part based on IEC 60112:2009, a UL 94 V0 classification at 1.5 mm, and, more preferably, a Vicat softening temperature measured according to DIN ISO 306 (2013 version, method B / 120) of at least 105 °C and no fracture in the Izod impact test according to ISO 180-U (2019 version).

[0014] Surprisingly, it was found that a composition containing A) 60 to 93 wt.%, preferably 65 to 90 wt.%, particularly preferably 70 to 90 wt.% of at least one aromatic polycarbonate, polyester carbonate or mixtures thereof, B) 2 to 20 wt.%, preferably 3 to 18 wt.%, particularly preferably 4 to 16 wt.% of a polyester based on at least one aromatic or at least one cycloaliphatic dicarboxylic acid or mixtures thereof and cyclohexanedimethanol and optionally at least one further aliphatic diol, C) 1 to 10 wt.%, preferably 2 to 9 wt.%, particularly preferably 3 to 9 wt.% of at least one phosphorus-containing flame retardant, possesses the desired properties.

[0015] In addition to components A, B and C, the composition may contain component D comprising one or more polymer additives, fillers and reinforcing agents, dyes, pigments, impact modifiers and / or polymers different from components A and B as blending partners, wherein the amount of component D is preferably 0.1 to 20 wt.%, based on the composition.

[0016] Preferably, the composition consists of at least 90 wt.%, and more preferably at least 95 wt.%, of components A to D. Particularly preferably, the composition consists only of components A to D.

[0017] A further object of the present invention is the use of 2 to 20 wt.% of a polyester based on an aromatic or cycloaliphatic dicarboxylic acid or mixtures thereof and cyclohexanedimethanol and optionally a further aliphatic diol and 1 to 10 wt.% of at least one phosphorus-containing flame retardant to improve the CTI and flame retardancy according to UL 94 V of polycarbonate compositions, preferably to achieve a CTI of 600 V preferably determined according to the rapid test method described in the example part in accordance with IEC 60112:2009 and a UL 94 V0 classification at a specimen thickness of 1.5 mm of polycarbonate compositions containing 60 to 93 wt.% polycarbonate.

[0018] Due to the good properties of the composition, it is also suitable for the production of components that have a small distance between electrical conductor tracks.

[0019] Another object of the present invention is therefore a component, preferably an electrical / electronic 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 that 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, where d2 is selected such that a flashover through the air is prevented at the respective operating voltage U for the component, and wherein d1 has the following values ​​at the operating voltages U listed below: d 1 0 V ≤ U ≤ 250 V : 1 , 3 mm bis < 4 , 0 mm d 1 250 V < U ≤ 500 V = 2 , 5 mm bis < 8 , 0 mm d 1 500 V < U ≤ 1000 V = 5 , 0 mm bis < 16 mm and wherein the thermoplastic material M comprises the following components: A) 60 to 93 wt.% of at least one aromatic polycarbonate, polyester carbonate or mixtures thereof, B) 2 to 20 wt.% polyester based on at least one aromatic or at least one cycloaliphatic dicarboxylic acid or mixtures thereof and cyclohexanedimethanol and optionally at least one further aliphatic diol, C) 1 to 10 wt.% of at least one phosphorus-containing flame retardant,

[0020] Preferably, the component has a protection rating of IP6K9K according to ISO 20653:2013, meaning it is protected against contact, ingress of foreign objects, and water. For such components, d1 has the following values ​​at the operating voltages U listed below: d1(0V ≤ U ≤ 250V): 1.3 mm to < 2.5 mm, more preferably 1.3 mm to < 1.8 mm; d1(250 V < U ≤ 500 V) = 2.5 mm to < 5.0 mm, more preferably 2.5 mm to < 3.6 mm; d1(500 V < U ≤ 1000 V) = 5.0 mm to < 10.0 mm, more preferably 5.0 mm to < 7.1 mm

[0021] Preferably, d2 is at least 1.2 mm, more preferably 1.2 to 10.0 mm. Determining the distance required to prevent air flashover is within the skill of a person skilled in the art.

[0022] The features mentioned as preferred, particularly preferred, etc. for the composition also apply with regard to the use and the component according to the invention. Component A

[0023] Aromatic polycarbonates and / or aromatic polyester carbonates suitable according to the invention, as described in component A, are known from the literature or can be produced using methods known from the literature (for the production of aromatic polycarbonates, see, for example, Schnell, "Chemistry and Physics of Polycarbonates", Interscience Publishers, 1964, as well as 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 production of aromatic polyester carbonates, see, for example, DE-A 3 007 934).

[0024] Aromatic polycarbonates can be produced, for example, by reacting diphenols with carbonic acid halides, preferably phosgene, and / or with aromatic dicarboxylic acid dihalides, preferably benzene dicarboxylic acid dihalides, using an interfacial process, optionally with the use of chain terminators, such as monophenols, and optionally with the use of trifunctional or more than trifunctional branchers, such as triphenols or tetraphenols. Production via a melt polymerization process by reacting diphenols with, for example, diphenyl carbonate is also possible.

[0025] Diphenols for the production of aromatic polycarbonates and / or aromatic polyester carbonates are preferably those of formula (1) where A a single bond, C 1 to C 5 alkylenes, C 2 to C 5 alkylidenes, C 5 to C 6 cycloalkylidenes, -O-, -SO-, -CO-, -S-, -SO 2-, C 6 to C 12 arylenes, to which further aromatic rings, optionally containing heteroatoms, may be fused, or a residue of formula (2) or (3) B each C 1 to C 12 -alkyl, preferably methyl, halogen, preferably chlorine and / or bromine x each independently of each other 0, 1 or 2, p 1 or 0, and R 5< and R 6< for each X 1< individually selectable, independently of each other hydrogen or C 1 to C 6 -alkyl, preferably hydrogen, methyl or ethyl, X1 carbon and m an integer from 4 to 7, preferably 4 or 5, with the proviso that at least one atom X 1< , R 5< and R 6< are simultaneously alkyl.

[0026] Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis-(hydroxyphenyl)-C 1 -C 5 -alkanes, bis-(hydroxyphenyl)-C 5 -C 6 -cycloalkanes, bis-(hydroxyphenyl) ethers, bis-(hydroxyphenyl) sulfoxides, bis-(hydroxyphenyl) ketones, bis-(hydroxyphenyl) sulfones and α,α,-bis-(hydroxyphenyl)-diisopropyl benzenes as well as their kembromated and / or nuclear-chlorinated derivatives.

[0027] 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.

[0028] The diphenols can be used individually or in any mixture. The diphenols are known from the literature or can be obtained through methods known from the literature.

[0029] Suitable chain termination compounds for the production of thermoplastic aromatic polycarbonates include, 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 total moles of the diphenols used.

[0030] The thermoplastic aromatic polycarbonates have mean molecular weights (average weight Mw) of preferably 20,000 to 40,000 g / mol, more preferably 22,000 to 32,000 g / mol, and particularly preferably 24,000 to 30,000 g / mol. These values ​​were measured by gel permeation chromatography (GPC) calibrated against bisphenol A polycarbonate standards using dichloromethane as the eluent. Calibration was performed using linear polycarbonates (from bisphenol A and phosgene) of known molar mass distribution from PSS Polymer Standards Service GmbH, Germany, and according to method 2301-0257502-09D (from 2009 in German) of Currenta GmbH & Co. OHG, Leverkusen. The eluent is dichloromethane. The columns are made of cross-linked styrene-divinylbenzene resins. The analytical columns have a diameter of 7.5 mm and a length of 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.

[0031] The preferred areas result in a particularly advantageous balance of mechanical and rheological properties in the compositions according to the invention.

[0032] The thermoplastic aromatic polycarbonates can be branched in a known manner, preferably by the incorporation of 0.05 to 2.0 mol%, based on the total amount of 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.

[0033] Both homopolycarbonates and copolycarbonates are suitable. For the production of copolycarbonates according to the invention, 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 3,419,634) and can be produced according to methods known in the literature. Polydiorganosiloxane-containing copolycarbonates are also suitable: the production of polydiorganosiloxane-containing copolycarbonates is described, for example, in DE-A 3,334,782.

[0034] 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.

[0035] Particularly preferred are mixtures of the diacid dichlorides of isophthalic acid and terephthalic acid in a ratio between 1:20 and 20:1.

[0036] In the production of polyester carbonates, a carbonic acid halide, preferably phosgene, is additionally used as a bifunctional acid derivative.

[0037] In addition to the monophenols already mentioned, other suitable chain terminators for the production of aromatic polyester carbonates include their chlorocarbonate esters, the acid chlorides of aromatic monocarboxylic acids, which may optionally be substituted by C 1 to C 22 alkyl groups or by halogen atoms, and aliphatic C 2 to C 22 monocarboxylic acid chlorides.

[0038] The amount of chain terminators is 0.1 to 10 mol% in each case, 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.

[0039] In the production of aromatic polyester carbonates, one or more aromatic hydroxycarboxylic acids can be used in addition.

[0040] 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.

[0041] Branching agents can include, for example, tri- or multi-functional carboxylic acid chlorides, such as trimesic acid trichloride, cyanuric acid trichloride, 3,3'-,4,4'-benzophenone tetracarboxylic acid tetrachloride, 1,4,5,8-napthalin tetracarboxylic acid tetrachloride, or pyromellitic acid tetrachloride, in amounts of 0.01 to 1.0 mol% (based on the dicarboxylic acid dichlorides used), or tri- or multi-functional 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-hydroxyphenyl)cyclohexyl]propane, 2,4-bis(4-hydroxyphenylisopropyl)phenol, tetra(4-hydroxyphenyl)methane, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, 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 introduced with the diphenols; acid chloride branching agents can be introduced together with the acid dichlorides.

[0042] In thermoplastic aromatic polyester carbonates, the proportion of carbonate structural units can vary as desired. Preferably, the proportion of carbonate groups is up to 100 mol%, particularly up to 80 mol%, and most preferably up to 50 mol%, based on the sum of ester and carbonate groups. Both the ester and carbonate components of the aromatic polyester carbonates can be present in the form of blocks or statistically distributed within the polycondensate.

[0043] The thermoplastic aromatic polycarbonates and polyester carbonates can be used alone or in any mixture.

[0044] Linear polycarbonate, preferably based exclusively on bisphenol A, is preferably used as component A. Component B

[0045] Component B of the composition contains a polyester based on at least one aromatic or at least one cycloaliphatic dicarboxylic acid or mixtures thereof and cyclohexanedimethanol, and optionally at least one further aliphatic diol. Mixtures of several such polyesters may also be used.

[0046] Based on this means that the polyester is produced, for example, by polymerizing the aforementioned dicarboxylic acid or an ester thereof with the aforementioned diols. The polyester thus contains structural units derived from an aromatic or cycloaliphatic dicarboxylic acid, as well as from cyclohexanedimethanol and optionally from another aliphatic diol.

[0047] Suitable aromatic or cycloaliphatic dicarboxylic acids include, for example, terephthalic acid residues, phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 2,5-furandicarboxylic acid and cyclohexanedicarboxylic acid.

[0048] Mixtures of different dicarboxylic acids can also be used; for example, a mixture of terephthalic acid and up to 25 mol% of another dicarboxylic acid can be used.

[0049] Preferably, the polyester contains only structural units derived from terephthalic acid and isophthalic acid as dicarboxylic acids, most preferably only from terephthalic acid.

[0050] The production of polyesters can be based on either terephthalic acid and the other acids mentioned, or on alkyl esters or anhydrides of the corresponding acids.

[0051] In addition to cyclohexanedimethanol, other aliphatic diols that can be used include, for example, ethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, isosorbide, and tetramethylcyclobutanediol. Ethylene glycol is preferred.

[0052] In another preferred embodiment, in addition to cyclohexanedimethanol, isosorbide and ethylene glycol are also used; the polyester is therefore composed of three diol components besides the acid component.

[0053] Component B is particularly preferred as a polyester based on terephthalic acid and a mixture of cyclohexanedimethanol and ethylene glycol. A molar ratio of cyclohexanedimethanol to ethylene glycol in the range of 40:60 to 80:20 is further preferred.

[0054] The production of the polyesters according to component B is known. It can be carried out by esterification in the presence of a catalyst, such as a zinc compound, followed by polycondensation. A vacuum can be applied, and the reaction can be carried out, for example, at a temperature between 150°C and 300°C.

[0055] In polycondensation, other catalysts containing titanium, germanium, tin, aluminum or antimony, as well as mixtures of different catalysts, can be used.

[0056] The reaction can be carried out continuously or discontinuously. The raw materials can be dosed separately or a premix can be used.

[0057] The polyesters according to component B have a weight-averaged molecular weight M w of preferably 10 to 100 kg / mol, e.g. measured by gel permeation chromatography in 1,1,1,3,3,3-hexafluoro-2-propanol at a concentration of 1 g / L with polymethyl methacrylate as standard.

[0058] Furthermore, the polyesters preferably have a melt volume flow rate (MVR) of 20-80 cm³ / 10 min, preferably of 30-70 cm³ / 10 min, each measured according to ISO 1133 (2012) at 270°C and a load of 5 kg.

[0059] The production of a polyester according to component B is described, for example, in "Modem Polyesters: Chemistry and Technology of Polyesters and Copolyesters", (edited by J. Scheirs and TE Long, John Wiley & Sons, Ltd 2003) and the prior art cited therein.

[0060] A suitable commercially available polyester is, for example, Skygreen™< JN100 (SK Chemicals Co., Ltd., Korea). Another suitable commercially available polyester is, for example, ECOZEN™< T120 (SK Chemicals Co., Ltd., Korea). Component C

[0061] Component C in the composition according to the invention is a phosphorus-containing flame retardant, preferably selected from the groups of mono- and oligomeric phosphoric and phosphonic acid esters and phosphazenes, wherein mixtures of several compounds selected from one or different of these groups can also be used as flame retardants.

[0062] Preferred mono- and oligomeric phosphoric or phosphonic acid esters are phosphorus compounds of the general formula (4) wherein R1<, R2<, R3< and R4<, each independently optionally halogenated C1 to C8 alkyl, each optionally substituted by alkyl, preferably C1 to C4 alkyl, and / or halogen, preferably chlorine, bromine, C5 to C6 cycloalkyl, C6 to C20 aryl or C7 to C12 aralkyl, n independently of each other, 0 or 1 q0 to 30 and X a mono- or polynuclear aromatic residue with 6 to 30 C atoms, or a linear or branched aliphatic residue with 2 to 30 C atoms, which may be OH-substituted and may contain up to 8 ether bonds.

[0063] Preferably, R< , R< , R< , R< , and R< represent, independently of one another, C< 1 to C< 4 alkyl, phenyl, naphthyl, or phenyl-C< 1-C< 4 alkyl. The aromatic groups R< , R< , R< , and R< 4 can themselves be substituted with halogen and / or alkyl groups, preferably chlorine, bromine, and / or C< 1 to C< 4 alkyl. Particularly preferred aryl groups are cresyl, phenyl, xylenyl, propylphenyl, or butylphenyl, as well as the corresponding brominated and chlorinated derivatives thereof.

[0064] X in formula (4) preferably represents a mono- or polynuclear aromatic residue with 6 to 30 carbon atoms. This is preferably derived from diphenols.

[0065] n in formula (4) can be 0 or 1 independently of each other, preferably n is equal to 1.

[0066] q represents values ​​from 0 to 30. When using mixtures of different components of formula (4), mixtures may preferably have number-averaged q values ​​of 0.3 to 10, particularly preferably 0.5 to 10, especially 1.05 to 1.4, most preferably 1.05 to 1.2.

[0067] X is particularly preferred for 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.

[0068] The component C according to the invention can be monophosphates (q=O), oligophosphates (q=1-30) or mixtures of mono- and oligophosphates.

[0069] Monophosphorus compounds of formula (1) include in particular tributyl phosphate, tris-(2-chloroethyl) phosphate, tris-(2,3-dibromoprobyl) phosphate, tri-(2-ethylhexyl) phosphate, triphenyl phosphate, tricresyl phosphate, diphenylcresyl phosphate, diphenyloctyl phosphate, diphenyl-2-ethylcresyl phosphate, tri-(isopropylphenyl) phosphate, halogen-substituted aryl phosphates, dimethyl methylphosphonic acid ester, diphenyl methylphosphenic acid ester, diethyl phenylphosphonic acid ester, triphenylphosphine oxide or tricresylphosphine oxide.

[0070] A particularly preferred phosphorus compound according to component C is bisphenol-A based oligophosphate according to formula (5).

[0071] 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 using known methods (e.g. Ullmanns Enzyklopädie der technischen Chemie, Vol. 18, p. 301 ff. 1979; Houben-Weyl, Methoden der ökologischen Chemie, Vol. 12 / 1, p. 43; Beilstein Vol. 6, p. 177).

[0072] 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.

[0073] Phosphazenes are compounds of formulas (6) and (7) wherein R is the same or different in each case and represents amino, optionally halogenated, preferably fluorine-halogenated C 1 to C 8 alkyl, or C 1 to C 8 alkoxy, optionally 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, where k represents 0 or a number from 1 to 15, preferably a number from 1 to 10.

[0074] Examples include propoxyphosphazene, phenoxyphosphazene, methylphenoxyphosphazene, aminophosphazene, and fluoroalkylphosphazene. Phenoxyphosphazene is preferred.

[0075] The phosphazenes can be used alone or as a mixture. The residue R can always be the same, or two or more residues 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. Component D

[0076] Component D may optionally include one or more representatives selected from the group consisting of polymer additives and polymeric blend partners in the composition.

[0077] The polymer additives or polymeric blend partners are preferably selected from the group consisting of anti-dripping agents, flame retardant synergists, smoke inhibitors, lubricants and demolding agents, nucleating agents, antistatic agents, conductivity additives, stabilizers, flow promoters, fillers and reinforcing agents, phase compatibility mediators, impact modifiers, and other polymeric components different from components A and B (e.g., functional blend partners, as well as dyes and pigments).

[0078] Examples of impact modifiers are: graft polymers with a core-shell structure and a graft base containing polybutadiene rubber such as ABS and MBS, with a graft base containing acrylate rubber or silicone rubber, or with a silicone acrylate rubber graft base such as the Metablen™< types from Mitsubishi Rayon Co., Ltd.; olefin-acrylate copolymers such as Elvaloy™< types from DuPont or Paraloid™< types from Dow; In a preferred embodiment, component D is at least one polymer additive selected from the group consisting of lubricating and demolding agents and stabilizers.

[0079] 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 Brønsted acids is used as a stabilizer.

[0080] In a preferred embodiment, fatty acid esters, particularly fatty acid esters of pentaerythritol or glycerol, are used as lubricating and demolding agents.

[0081] In a further preferred embodiment, component D contains at least one graft polymer with a core-shell structure and / or a rubber-free vinyl(co)polymer, further preferably in an amount of 1 to 10 wt.%, based on the composition containing components A, B, C and D.

[0082] Graft polymers with a core-shell structure and a graft base containing polybutadiene rubber are particularly preferred.

[0083] A styrene-acrylonitrile copolymer is particularly preferred as a rubber-free vinyl(co)polymer.

[0084] The quantity and type of component D must of course be selected in such a way that the flame retardancy and CTI are not significantly impaired. Production of a molding compound from the composition

[0085] A thermoplastic molding compound can be produced from the composition containing the components A, B and C according to the invention, and optionally D.

[0086] The thermoplastic molding compound can be produced, for example, by mixing the respective components of the composition in a known manner and melt-compounding and melt-extruding it at temperatures preferably 200°C to 320°C, particularly preferably 240°C to 300°C, and most preferably 260°C to 290°C in conventional equipment such as internal kneaders, extruders and twin-screw extruders.

[0087] This process is generally referred to as compounding within the context of this application.

[0088] Molding compound is therefore understood to be the product that is obtained when the components of the composition are melt compounded and melt extruded.

[0089] The individual components of the composition can be mixed in a known manner, either successively or simultaneously, both at approximately 20°C (room temperature) and at higher temperatures. This means, for example, that some of the components can be metered via the main feed of an extruder, while the remaining components can be added later in the compounding process via a side extruder.

[0090] The molding compounds can be used to produce molded parts. These can be manufactured, for example, by injection molding, extrusion, and blow molding. Another processing method is the production of molded parts by deep drawing from previously manufactured sheets or films. The molding compounds are particularly suitable for processing in extrusion, blow molding, and deep drawing processes.

[0091] It is also possible to dose the components of the compositions directly into the conveying extruder of an injection molding machine, to produce the molding compound in the conveying extruder and to process it directly into molded parts by appropriate discharge of the molding compound into an injection mold (compounding or reactive compound injection molding).

[0092] A further object of the present invention relates to the use of a composition or molding compound according to the invention for the production of molded parts, and furthermore also to a molded part that is obtainable from a composition or molding compound according to the invention or that contains such a molding compound. A molded part in the sense of the invention can also be an insulating layer in an electrical component such as a transistor. In particular, the molded part is the component described above, which is more preferably an electrical / electronic component.

[0093] The component is preferably 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 plug for electric vehicles, electrical junction box, smart meter housing, miniature disconnect switch, or busbar. It is also possible that the component is the entire element and not just a part of it.

[0094] A component according to the invention can, for example, be manufactured by injection molding with overmolding of metallic conductor tracks. Pre-assembled 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, causing them to bond together when cooled. After solidification and demolding, the finished component can be used.

[0095] An alternative is integrated plastic-metal injection molding (ICMS). In this process, the finished component is manufactured in two steps. First, the plastic component is produced, incorporating the conductive traces that will later be filled. Then, the finished plastic component is transferred to a second cavity and filled with solder, which, once solidified, forms the conductive traces.

[0096] Another alternative is to subsequently connect an injection-molded component to the conductor tracks. This means the plastic component is manufactured using injection molding and then assembled with the conductor in a subsequent step. The injection-molded component can be joined during assembly by applying additional energy. Several methods exist for this; for example, the metallic conductor can be heated intensely so that it can be pressed into the plastic component. Alternatively, the conductor can be directly bonded to the plastic component using laser welding. Examples Component A-1:

[0097] Linear polycarbonate based on bisphenol-A with a weight-averaged molecular weight MW of 26000 g / mol (determined by GPC in methylene chloride with polycarbonate based on bisphenol A as standard). Component A-2:

[0098] Linear polycarbonate based on bisphenol-A with a weight-averaged molecular weight MW of 24000 g / mol (determined by GPC in methylene chloride with polycarbonate based on bisphenol A as standard). Component B

[0099] Skygreen™< JN100 (SK Chemicals Co., Ltd, Korea): Co-polyester based on terephthalic acid, cyclohexanedimethanol, ethylene glycol and diethylene glycol in a molar ratio of 44.4 : 30.7 : 23.7 : 1.1 with a weight-averaged molecular weight MW of 46000 g / mol (determined by GPC in hexafluoroisopropanol with polymethyl methacrylate as standard) and a melt volume flow rate (MVR) of 51 cm³ / [10 min], measured according to ISO 1133 (version of 2012) at a temperature of 270 °C and a load of 5 kg. Component C

[0100] Bisphenol-A based oligophosphate according to the following structure (Chemtura Manufacturing UK Limited) Component D-1

[0101] Pentaerythritol tetrastearate as a demolding agent, Cognis Oleochemicals GmbH, Germany Component D-2

[0102] Dimeric phosphonite Irgafos ™< P-EPQ, Tetrakis(2,4-di-tert-butylphenyl)-1,1-biphenyl-4,4'-diylbisphosphonite, BASF (Germany) Component D-3

[0103] Sterically hindered phenol Irganox™< 1076, Octadecyl-3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionate], BASF (Germany) Component D-4

[0104] Cycolac ™< INP449: Polytetrafluoroethylene (PTFE) preparation from Sabic consisting of 50 wt% PTFE contained in a SAN copolymer matrix. Component D-5

[0105] Phosphorous acid, H₃PO₃, Sigma-Aldrich Chemie GmbH, Germany Production and testing of the molding compounds from the compositions

[0106] The components were mixed on a Coperion ZSK-26 Mc18 twin-screw extruder at a melt temperature of 250 °C - 280 °C. The molded parts were produced on an Arburg 270 E injection molding machine at a melt temperature of 270 °C and a mold temperature of 70 °C.

[0107] The IZOD impact strength was determined at room temperature on test bars with dimensions of 80 mm x 10 mm x 4 mm according to ISO 180-U (version of 2019).

[0108] 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 single-sided injection-molded test bar of dimensions 80x10x4 mm.

[0109] Flame retardancy was assessed according to UL94V on rods measuring 127 x 12.7 x 1.5 mm.

[0110] The tracking resistance of the compositions described here was 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 to 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, provided that 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 any 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. 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 a "rapid test method based on" the aforementioned standard. Table 1: Inventive compositions and their properties Components [wt.%] 1 1504-A 2 1504-B 3 1506-A 4 1506-B A-1 84,28 79,28 80,28 75,28 A-2 5,00 5,00 5,00 5,00 B 5,00 10,00 5,00 10,00 C 4,00 4,00 8,00 8,00 D-1 (PETS) 0,6 0,6 0,6 0,6 D-2 (Irgafos P-EPQ) 0,1 0,1 0,1 0,1 D-3 (Irganox 1076) 0,2 0,2 0,2 0,2 D-4 (PTFE / SAN Masterbatch) 0,8 0,8 0,8 0,8 D-5 (Phosphorous acid) 0,02 0,02 0,02 0,02 B / phosphorus ratio 14 28 7 14 Characteristics Izod impact strength [kJ / m²<] kb kb kb kb Vicat softening temperature [°C] 121 118 110 107 Flame retardancy according to UL94 V at 1.5 mm V-0 V-0 V-0 V-0 Tracking resistance [V] 600 600 600 600 kb means "no break"

[0111] The data from Table 1 show that test specimens made from the compositions according to the invention exhibit a high CTI, very good flame retardancy, as well as high heat resistance and impact strength. Table 2: Non-inventive compositions and their properties Components [wt.%] V5 1504-D V6 1506-D V7 1503-A V8 1503-B V9 1503-D A-1 59,28 55,28 76,28 71,28 51,28 A-2 5,00 5,00 5,00 5,00 5,00 B 30,00 30,00 5,00 10,00 30,00 C 4,00 8,00 12,00 12,00 12,00 D-1 (PETS) 0,6 0,6 0,6 0,6 0,6 D-2 (Irgafos P-EPQ) 0,1 0,1 0,1 0,1 0,1 D-3 (Irganox 1076) 0,2 0,2 0,2 0,2 0,2 D-4 (PTFE / SAN Masterbatch) 0,8 0,8 0,8 0,8 0,8 D-5 (Phosphorous acid) 0,02 0,02 0,02 0,02 0,02 B / phosphorus ratio 84 42 5 9 28 Characteristics Izod impact strength [kJ / m²<] kb 244 151 143 137 Vicat softening temperature [°C] 106 95 102 100 89 Flame retardancy according to UL94 V at 1.5 mm V-2 V-2 V-0 V-0 V-0 Tracking resistance [V] 600 600 275 300 375 kb means "no break"

[0112] The data from Table 2 show that test specimens made from non-inventive compositions do not achieve the desired properties. If the proportion of component B is too high, as in V5 and V6, the required flame retardancy cannot be achieved, even with an increased amount of component C. In this case (V6), the heat deflection temperature is also reduced. If the proportion of component C is increased even further, the flame retardancy can be improved again (V9), but the heat deflection temperature is very low. In addition, the tracking resistance (CTI) is no longer sufficient. Examples V7 and V8, in which the proportion of component C is also too high, also show low tracking resistance. Furthermore, all examples with an excessively high proportion of component C exhibit insufficient impact strength, i.e., fracture is observed in each case (V7, V8, and V9).

Claims

1. Composition comprising A) 60% to 93% by weight of at least one aromatic polycarbonate, polyestercarbonate or mixtures thereof, B) 2% to 20% by weight of a polyester based on at least one aromatic or at least one cycloaliphatic dicarboxylic acid or mixtures thereof and cyclohexanedimethanol and optionally at least one further aliphatic diol, C) 1% to 10% by weight of at least one phosphorus-containing flame retardant.

2. Composition according to Claim 1, characterized in that component B is an amorphous polyester.

3. Composition according to Claim 1 or 2, characterized in that the ratio of the proportion by weight of component B in the composition to the proportion by weight of phosphorus in the composition is less than 40, preferably greater than 5 to less than 40.

4. Composition according to any of the preceding claims, characterized in that component B is a polyester based on terephthalic acid and cyclohexanedimethanol and ethylene glycol.

5. Composition according to Claim 4, characterized in that the molar ratio of cyclohexanedimethanol to ethylene glycol is 40:60 to 80:20.

6. Composition according to any of the preceding claims, characterized in that component B is based on a mixture of cyclohexanedimethanol, ethylene glycol and isosorbide as diol component.

7. Composition according to any of the preceding claims, characterized in that component C is selected from the group consisting of mono- and oligomeric phosphoric and phosphonic esters, phosphazenes and mixtures of these compounds.

8. Composition according to any of the preceding claims, characterized in that used as component C is a compound of the general formula (4) in which 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.

9. Composition according to any of the preceding claims, comprising 65% to 90% by weight of component A 3% to 18% by weight of component B 2% to 9% by weight of component C.

10. Composition according to any of the preceding claims, further comprising, as component D, 0.1% to 20% by weight of at least one polymer additive from the group consisting of anti-drip agents, flame retardant synergists, smoke inhibitors, lubricants and mould-release agents, nucleating agents, antistats, conductivity additives, stabilizers, flow promoters, fillers and reinforcers, phase compatibilizers, impact modifiers, further polymeric constituents different from components A and B, and dyes and pigments.

11. Composition according to Claim 10, wherein the composition comprises, as component D, at least one graft polymer with core-shell structure and / or rubber-free vinyl (co)polymer in an amount of together 1% to 10% by weight.

12. Use of 2% to 20% by weight of a polyester based on an aromatic or cycloaliphatic dicarboxylic acid or mixtures thereof and cyclohexanedimethanol and optionally a further aliphatic diol and 1% to 10% by weight of at least one phosphorus-containing flame retardant for improving the CTI determined as defined in the description and the flame retardancy according to UL 94 V of polycarbonate compositions.

13. Use according to Claim 12, wherein a CTI of 600 V determined as defined in the description and a UL 94 V0 classification at a test specimen thickness of 1.5 mm of polycarbonate compositions comprising 60% to 93% by weight of polycarbonate is attained.

14. Component comprising a first electrical conductor L1 and a second electrical conductor L2 at a first distance d1 and a second distance d2 with respect 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) 60% to 93% by weight of at least one aromatic polycarbonate, polyestercarbonate or mixtures thereof, B) 2% to 20% by weight of a polyester based on an aromatic or cycloaliphatic dicarboxylic acid or mixtures thereof and cyclohexanedimethanol and optionally a further aliphatic diol, C) 1% to 10% by weight of at least one phosphorus-containing flame retardant.

15. Component according to Claim 14, wherein the component has an IP6K9K degree of protection according to ISO 20653:2013 and wherein d1, at the operating voltages 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 .