Flame retardant composition

Abstract

The present invention relates to a thermoplastic composition comprising polycarbonate, Impact modifier having a rubber content of from 40 to 70 wt.%, phosphorous based flame retardant and an anti-drip agent. The composition has a UL94 flame retardancy rating of V0 at 1.5mm and a melt volume rate of from 10 to 25 cm3 / 10 min as determined in accordance with ISO 1133 (260°C, 2.16 kg).

Description

[0001] 24POLY0081-WO-ORD 1

[0002] FLAME RETARDANT COMPOSITION

[0003] The present invention relates to a flame retardant thermoplastic composition based on impact modified polycarbonate.

[0004] Blends of polycarbonate (PC) and impact modifiers, in particular copolymers of acrylonitrile, butadiene and styrene (ABS) are known per se and used in many application such as for example in electric or electronic applications like mobile phones, laptop computers, televisions, monitors, household appliances and the like. Other applications include automotive interior or exterior applications. The blends of PC and ABS may be referred to herein as PC / ABS.

[0005] Some applications require that these blends have a certain flame retardancy at low thickness and for that purpose impact modified blends of polycarbonate exist which contain a flame retardant system. Typically such a flame retardant system comprises a flame retardant and an anti-drip agent. Typically either or both the flame retardant and the anti-drip agent may comprise per-fluoroalkyl or polyfluoroalkyl substances, also known as PFAS. Such materials are considered to have a negative impact on the environment and / or may be harmful to humans and animals.

[0006] Flame retardant impact modified polycarbonate compositions, in particular PC / ABS compositions are known in the art per se.

[0007] For example, WO2016 / 042426 discloses a thermoplastic composition, comprising: a) from about 50 wt.% to about 70 wt.% of a polycarbonate component; b) from about 5 wt.% to about 20 wt.% of a high-rubber grafted acrylonitrile-butadiene-styrene copolymer component or a methyl (meth) acrylate-butadiene-styrene component; c) from about 5 wt.% to about 20 wt.% of a styrene-acrylonitrile copolymer; d) from about 5 wt.% to about 20 wt.% of flame retardant component; and e) from about 0.5 wt.% to about 5 wt.% of a mineral filler; wherein all weight percent values are based on the total weight of the composition; and further comprising a colorant in an amount from about 0.001 wt.% to about 10 wt.% of the total weight of a) to e).24POLYOQ81-WO-ORD 2

[0008] CN 112795159 discloses a PC / ABS alloy composition as well as a preparation method and application thereof. The PC / ABS alloy composition comprises PC resin, ABS resin, ABS high rubber powder and / or a modifier thereof, an organic phosphorus flame retardant, an anti-dripping agent and an optional antioxidant. The alloy composition has good flame retardance, normal-temperature toughness and low-temperature toughness.

[0009] It is an object of the invention to provide for a polycarbonate rich, impact modified polycarbonate composition that combines good impact properties with sufficient flame retardancy at low thickness.

[0010] To that extent the present invention relates to a thermoplastic composition comprising, based on the weight of the composition,

[0011] (A) from 75 to 85 wt.% of polycarbonate

[0012] (B) from 4 to 12 wt.% of impact modifier,

[0013] (C) from 8 to 16 wt.% of phosphorous based flame retardant,

[0014] (D) from 0.2 to 1.5 wt.% of anti-drip agent,

[0015] (E) from 0 to 6 wt.% of styrene-acrylonitrile copolymer,

[0016] (F) from 0 to 3 wt.% of further components

[0017] wherein

[0018] the sum of the components (A) to (F) is 100 wt.%,

[0019] the composition has or is selected to have a UL94 flame retardancy rating of V0 at 1.5mm

[0020] the composition has a melt volume rate of from 10 to 25 cm3 / 10 min as determined in accordance with ASTM D 1238 (260°C, 2.16 kg),

[0021] the impact modifier is a copolymer selected from the group consisting of acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, styrene-butadiene-styrene copolymer, styrene-ethylene-butadiene-styrene copolymer, acrylonitrile-styrene-(butyl)acrylate copolymer, or mixtures of two or more of the foregoing impact modifiers, having a rubber content of from 40 to 70 wt.%, based on the weight of the copolymer(s).

[0022] For the avoidance of doubt, the present invention is directed at compositions wherein the impact modifier has a rubber content of from 40 to 70 wt.%, based on the weight of the impact modifier, i.e. the copolymer(s).24POLYOQ81-WO-ORD 3

[0023] In particular the present invention relates to a thermoplastic composition comprising, based on the weight of the composition,

[0024] (A) from 75 to 85 wt.% of polycarbonate

[0025] (B) from 4 to 12 wt.% of acrylonitrile-butadiene-styrene copolymer having a polybutadiene rubber content of from 40 to 70 wt.%, based on the weight of the copolymer,

[0026] (C) from 8 to 16 wt.% of phosphorous based flame retardant,

[0027] (D) from 0.2 to 1.5 wt.% of anti-drip agent,

[0028] (E) from 0 to 6 wt.% of styrene-acrylonitrile copolymer,

[0029] (F) from 0 to 3 wt.% of further components

[0030] wherein the sum of the components (A) to (F) is 100 wt.%, and wherein the composition has or is selected to have a UL94 flame retardancy rating of V0 at 1.5mm and a melt volume rate of from 10 to 25 cm3 / 10 min as determined in accordance with ASTM D 1238 (260°C, 2.16 kg).

[0031] Unless specifically stated otherwise, or as evident from the context, the following description shall apply to both of the above definitions of the invention wherein eitherthe component (B) is defined as an impact modifier or wherein the component (B) is acrylonitrile-butadiene-styrene copolymer.

[0032] Polycarbonate (A)

[0033] The polycarbonate (A) in the composition of the present invention is typically an aromatic polycarbonate, more in particular a polycarbonate comprising or consisting of repeating units originating from a bisphenol, such as in particular bisphenol A. Notwithstanding the foregoing, the polycarbonate (A) may comprise polycarbonates homopolymers or copolymers based on other bisphenols. The amount of such non-bisphenol A polycarbonates is preferably at most 10 wt.%, based on the amount of polycarbonate (A).

[0034] The polycarbonate in the composition of the invention can be one type of polycarbonate or a mixture of at least two polycarbonates where each may be a homopolymer or a copolymer. It is preferred that the polycarbonate comprises or consists of at least one polycarbonate homopolymer obtained by reacting a bisphenol, such as bisphenol A, with a carbonate source such as phosgene or a diarylcarbonate such as diphenyl carbonate.24POLYOQ81-WO-ORD 4

[0035] Accordingly the polycarbonate of the thermoplastic composition according to the invention may be prepared using the so called interfacial process, wherein BPA reacts with phosgene, or may be prepared by means of the so-called melt or direct transesterification process, wherein BPA reacts with diphenyl carbonate. These two types of polycarbonate are known to the skilled person and may be further referred to herein as interfacial polycarbonate and melt polycarbonate. The skilled person knows that these two types of polycarbonate differ in amount of Fries branching, which only exists in melt polycarbonate and further in the terminal hydroxyl content, which is typically is absent or at least significantly lower for interfacial polycarbonate. The Fries branching content for melt polycarbonate may be from 500 to 4000 ppm, such as from 750 to 2000 ppm.

[0036] It is preferred that the polycarbonate comprises or consists of interfacial polycarbonate for the reason that interfacial polycarbonate, compared to the melt polycarbonate typically has a low number of hydroxyl chain ends, if any . A low amount of hydroxyl chain ends may be advantageous for heat stability and color retention of the polycarbonate.

[0037] The polycarbonate (A) may consists of a mixture of at least one interfacial bisphenol A polycarbonate homopolymer and at least one melt bisphenol A polycarbonate homopolymer. For example, the mixture may consists of 5 to 20 wt.% of interfacial bisphenol A polycarbonate homopolymer and of 95 to 80 wt.% of melt bisphenol A polycarbonate homopolymer, based on the weight the polycarbonate.

[0038] Notwithstanding the foregoing, the polycarbonate (A) may comprise at least 80 wt.% of interfacial polycarbonate, based on the weight of the polycarbonate (A).

[0039] In case the thermoplastic composition would be used for applications wherein a moulded part would be coated with a 2-component polyurethane coating it is preferred that the polycarbonate (A) has a relatively high number of free hydroxyl groups of at least 250ppm, such as from 400 to 1500 or 500 to 1200 ppm. In such applications the polycarbonate (A) preferably has an endcap level (EC%) of at most 85% as calculated with Formula I24POLYOQ81-WO-ORD 5

[0040] ppmOH X Mn

[0041] %EC = 100 - . 340000

[0042] wherein %EC is the endcap level, ppmOH is the hydroxyl content in parts per million by weight and Mn is the number average molecular weight of the polycarbonate based on polycarbonate standards and determined using gel permeation chromatography. The endcap level essentially reflects the percentage of polycarbonate chain ends which are not hydroxyl groups. Thus a polycarbonate having and endcap level of 70% means that the polycarbonate has 30% of phenolic OH groups, usually resulting from the bisphenol A monomer. The other 70% of end groups do not contain a OH group and may be phenolic (usually originating from the diphenyl carbonate) or correspond to an end capping agent molecule(s), if used. Without willing to be bound to it the present inventors consider that the use of such polycarbonate allows for an improved adhesion of the polyurethane coating because part of the isocyanate groups of the two-component polyurethane coating reacts with the phenolic OH groups in the polycarbonate chains.

[0043] For applications that do not require improved adhesion to 2-component polyurethane coating the polycarbonate may have an endcap level of at least 85%, preferably at least 90%, more preferably at least 95%.

[0044] The polycarbonate (A) may consist of polycarbonate obtained by means of an interfacial process having a phenolic OH group content of at most 5 ppm.

[0045] The polycarbonate, in particular bisphenol A polycarbonate homopolymer obtained via an interfacial process, is preferably endcapped with an endcapping agent selected from the group consisting of p-cumyl-phenol, dicumyl-phenol, p-ter-butyl phenol and mixtures of at least two of the foregoing.

[0046] The polycarbonate may comprises or consists of melt polycarbonate, i.e. polycarbonate obtained by a melt transesterification process. In some embodiments the polycarbonate comprises or consists of a mixture of at least one melt polycarbonate and at least one interfacial polycarbonate. In such an embodiment the amount of melt polycarbonate may be from 30 to 70 wt.% and the amount of interfacial polycarbonate from 70 to 30 wt.%, based on the combined weight of the melt polycarbonate and the interfacial polycarbonate.24POLYOQ81-WO-ORD 6

[0047] For the purpose of flexibility in optimising the flow properties of the thermoplastic composition it is preferred that the polycarbonate comprises (in addition to optional branched polycarbonate) at least a first polycarbonate and a second polycarbonate, said second polycarbonate having a melt flow rate that is at least 10 g / 10min higher than the melt flow rate of the first polycarbonate, determined in accordance with ASTM D 1238 (300°C, 1.2 kg). The first polycarbonate has a melt flow rate of from 2 to 16 g / 10min and the second polycarbonate has a melt flow rate of from 12 to 40 g / 10min, determined in accordance with ASTM D1238 (300°C, 1.2 kg).

[0048] Preferably, polycarbonate (A) comprises, based on the weight of the polycarbonate (A), at least 90 wt.%, preferably at least 95 wt.%, more preferably at least 99 wt.%, of bisphenol A polycarbonate homopolymer. More preferably polycarbonate (A) consists of bisphenol A polycarbonate homopolymer.

[0049] Interfacial polycarbonate may be end-capped, at least in part, with an endcapping agent selected from the group consisting of para-cumyl-phenol, dicumyl phenol, tert-butyl-phenol and mixtures of two or more of the foregoing

[0050] Preferably, the polycarbonate (A) has a melt flow rate according to ISO1133 at 300 °C and 1.2 kg of from 2.0 to 40 g / 10min, preferably 3 to 30 g / 10min, preferably from 4.0 to 28 g / 10min. For the avoidance of doubt, the melt flow rate is the melt flow rate on the polycarbonate (A) which may be a mixture of at least two polycarbonates. The individual polycarbonates may have a melt flow rate less than 2 or more than 40 g / 10min as long as the resulting mixture falls within the preferred range.

[0051] The amount of polycarbonate in the composition is preferably from 55 to 70 wt.%.

[0052] The polycarbonate (A) optionally comprises branched polycarbonate. Branched polycarbonate is known per se and is typically an interfacial polycarbonate. For the purpose of the present invention melt polycarbonate having a certain amount of Fries branching is not to be considered as branched polycarbonate. While branched polycarbonate is typically obtained under application of a branching agent added during24POLYOQ81-WO-ORD 7

[0053] the polymerisation process, branched polycarbonate is not to be considered as a copolymer merely because it contains some groups originating from a branching agent.

[0054] Preferably the amount of branched polycarbonate is from 1 to 60 wt.%, preferably 5 to to 50 wt.% based on the weight of the polycarbonate (A). More preferably the amount of branched polycarbonate is from 10 to 40 wt.%. The branched polycarbonate is preferably a bisphenol A polycarbonate homopolymer. The branching units may correspond to known branching agents as used in the process to manufacture branched polycarbonate.

[0055] Branched polycarbonates, known per se, can be manufactured by adding a branching agent during the (interfacial) polymerisation process. The branching agent is added in an amount (relative to the bisphenol monomer) that is sufficient to achieve the desired branching content. Branching agents include aromatic triacyl halides, for example triacyl chlorides of formula (1)

[0056] (1)

[0057]

[0058] wherein Z is a halogen, C1-3 alkyl, C1-3 alkoxy, C7-12 arylalkylene, C7-12 alkylarylene, and z is 0 to 3;

[0059] a trisubstituted phenol of formula (2)

[0060] (2)

[0061]

[0062] OH24POLYOQ81-WO-ORD 8

[0063] wherein T is a C1-20 alkyl, C1-20 alkyleneoxy, C7-12 arylalkyl, or C7-12 alkylaryl, Y is a halogen, C1-3 alkyl, C1-3 alkoxy, C7-12 arylalkyl, C7-12 alkylaryl and y is 0 to 4;

[0064] ora compound of formula (3) (isatin-bis-phenol).

[0065]

[0066] Examples of specific branching agents that are particularly effective include trimellitic trichloride (TMTC), tris-p-hydroxyphenylethane (THPE), and isatin-bis-phenol, with THPE being preferred.

[0067] The desired degree of branching can be achieved by appropriately selecting the reaction conditions, the amount of branching agents and the amount of chain stopper (i.e. endcapping agent) as applied in the interfacial process. This is known to the skilled person per se.

[0068] In general, the amount of branching agent is effective to provide 0.1 to 10 branching units per 100 of repeating bisphenol units of the polycarbonate, specifically 0.5 to 8 branching units per 100 bisphenol units, and more specifically 0.75 to 5 branching units per 100 bisphenol units.

[0069] A combination of two or more branching agents may be used.

[0070] The branched polycarbonate may have a melt flow rate of from 0.2 to 5, preferably 0.5 to 3, more preferably 0.8 to 2 g / 10 min as determined in accordance with ISO 1133 (300°C, 1.2 kg).. Preferably the branched polycarbonate is a bisphenol A polycarbonate homopolymer with branching units derived from THPE.24POLYOQ81-WO-ORD 9

[0071] For branching agents having formula (2) or (3), the branching agent triphenyl carbonate groups formed are present in an amount of 0.1 to 10 branching units per 100 R1 units, specifically 0.5 to 8 branching units per 100 R1 units, and more specifically 0.75 to 5 triphenylcarbonate units per 100 R1 units. In some embodiments, a combination of two or more branching agents may be used. Alternatively, the branching agents can be added at a level of 0.05 to 2.0 wt.%.

[0072] Branched polycarbonate may be added to enhance the melt strength which allows for an improved or at least more robust flame retardancy in accordance with the UL94 test methods.

[0073] For the purpose of the present invention a polycarbonate-polysiloxane copolymer is not regarded as a polycarbonate (A).

[0074] In some embodiments, the polycarbonate comprises post-consumer recycled (PCR) polycarbonate or post-industrial recycled (PIR) polycarbonate. Thus, the polycarbonate (A) may comprise recycled polycarbonate, preferably mechanically recycled or solvent-recycled polycarbonate. Preferably the amount of recycled polycarbonate is from 10 to 90 wt.%, preferably 10 to 40, more preferably 10 to 30 wt.%, based on the weight of the polycarbonate (A).

[0075] For the avoidance of doubt, a polycarbonate-polysiloxane copolymer is not to be considered as a polycarbonate. Thus, polycarbonate (A) does not comprise polycarbonate-polysiloxane copolymer.

[0076] Impact modifier (B)

[0077] In accordance with the invention the impact modifier is selected from the group consisting of acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, styrene-butadiene-styrene copolymer, styrene-ethylene-butadiene-styrene copolymer, acrylonitrile-styrene-(butyl)acrylate copolymer, or mixtures of two or more of the foregoing impact modifiers, having a rubber content of from 40 to 70 wt.%. Preferably the rubber content is from 50 to 65 wt.%, more preferably from 55 to 65 wt.%.

[0078] The impact modifier may be selected from the group consisting of acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, styrene-24POLY0081-WO-ORD 10

[0079] ethylene-butadiene-styrene copolymer, acrylonitrile-styrene-(butyl)acrylate copolymer, or mixtures of two or more of the foregoing impact modifiers, having a rubber content of from 40 to 70 wt.%. Preferably the rubber content is from 50 to 65 wt.%, more preferably from 55 to 65 wt.%.

[0080] Preferably the impact modifier comprises or consists of acrylonitrile-butadiene-styrene copolymer. Thus, the amount of acrylonitrile-butadiene-styrene copolymer in impact modifier (B) and having a polybutadiene content of from 40 to 70 wt.% based on the weight of the acrylonitrile-butadiene-styrene copolymer, is preferably at least 50 wt.%, more preferably at least 80 wt.%, at least 90 wt.%, at least 95 wt.% or at least 99 wt.%, based on the weight of impact modifier (B). Most preferably impact modifier (B) consists of acrylonitrile-butadiene-styrene copolymer having a polybutadiene content of from 40 to 70 wt.%, based on the weight of the acrylonitrile-butadiene-styrene copolymer.

[0081] The impact modifier is preferably free of acrylonitrile-butadiene-styrene copolymer having a polybutadiene content below 35 wt.% based on the weight of the acrylonitrile-butadiene-styrene copolymer. Thus, it is preferred that the acrylonitrile-butadiene-styrene copolymer is a high-rubber-graft acrylonitrile-butadiene-styrene copolymer (HRG-ABS) prepared using an emulsion-based process, where preferably the acrylonitrile-butadiene-styrene copolymer does not comprise acrylonitrile-butadiene-styrene copolymer prepared with a bulk process, i.e. b-ABS.

[0082] Acrylonitrile-butadiene-styrene copolymers, sometimes also referred to as terpolymers, are known per se and are typically manufactured using two types of techniques. In a first technique the monomers are reacted in a bulk polymerisation to yield a copolymer having a relatively low polybutadiene, i.e. rubber, content. This material, which may be referred to herein as bulk ABS, or b-ABS. To the contrary acrylonitrile-butadiene-styrene copolymers can also be manufactured using an emulsion polymerisation technique wherein first a polybutadiene latex is produced and wherein in a next step the rubber particles of the latex are graft copolymerised with styrene and acrylonitrile. As a result of this, ABS materials with a relatively high rubber content can be obtained. This type of material may be referred to herein as HRG-ABS.24POLY0081-WO-ORD 11

[0083] Preferably the impact modifier (B) comprises or consists of acrylonitrile-butadiene-styrene copolymer, in particular HRG-ABS. The acrylonitrile-butadiene-styrene copolymer has a polybutadiene rubber content of from 40 to 70 wt.%, based on the weight of the acrylonitrile-butadiene-styrene copolymer. Preferably the polybutadiene rubber content is from 50 to 65 wt.%, more preferably from 55 to 65 wt.%. This rubber content is achieved by selecting the appropriate amount of HRG-ABS. Thus, while it is preferred that acrylonitrile-butadiene-styrene copolymer (B) consists of HRG-ABS the acrylonitrile-butadiene-styrene copolymer (B) may also be a mixture of several acrylonitrile-butadiene-styrene copolymers with mutually different polybutadiene rubber contents, provided that the total rubber content is from 40 to 70 wt.%. For example the acrylonitrile-butadiene-styrene copolymer (B) may comprise from 70 to 100 wt.%, or 80 to 100 wt.%, or 90 to 100 wt.% of HRG-ABS and from 0 to 30 wt.%, 0 to 20 wt.% or 0 to 10 wt.% of b-ABS.

[0084] The impact modifier (B) may be a mixture of at least one acrylonitrile-butadiene-styrene copolymer and at least one further copolymer selected from the group consisting of, methyl methacrylate-butadiene-styrene copolymer, styrene-butadiene-styrene copolymer, styrene-ethylene-butadiene-styrene copolymer and acrylonitrile-styrene-(butyl)acrylate copolymer.

[0085] HRG-ABS copolymers typically comprise at least 90 wt.% of styrene-acrylonitrile copolymer grafted onto the polybutadiene, the remainder being free, i.e. ungrafted, styrene-acrylonitrile copolymer (SAN). It is preferred that the amount of free styreneacrylonitrile copolymer is as low as possible such as preferably at most 5 wt.%, more preferably at least 2 wt.% based on the weight on the HRG-ABS. Most preferably the HRG-ABS does not contain free styrene-acrylonitrile copolymer.

[0086] The amount of styrene and acrylonitrile in the HRG-ABS may vary such that the styrene to acrylonitrile weight ratio is from 90:10 to 60:40.

[0087] The HRG-ABS is typically in the form of a core-shell polymer built up from a rubber-like polybutadiene core on which one or more shells of styrene-acrylonitrile copolymer have been grafted.24POLYOQ81-WO-ORD 12

[0088] The impact modifier may comprise or consist of recycled impact modifier, in particular recycled high rubber graft acrylonitrile-polybutadiene-styrene copolymer. The amount of recycled impact modifier may be at least 10 wt.%, preferably from 10 to 60 wt.%, based on the weight of impact modifier (B).

[0089] The acrylonitrile-butadiene-styrene copolymer may comprise or consist of recycled acrylonitrile-butadiene-styrene copolymer, in particular recycled high rubber graft acrylonitrile-polybutadiene-styrene copolymer. The amount of recycled acrylonitrile-butadiene-styrene copolymer may be at least 10 wt.%, preferably from 10 to 60 wt.%, based on the weight of acrylonitrile-butadiene-styrene copolymer (B).

[0090] Phosphorous-based flame retardant (C)

[0091] The phosphorous based flame retardant is preferably selected from the group consisting of bisphenol A di-phosphate (BPADP), resorcinol diphosphate (RDP), tri-phenyl-phosphate (TPP), solid oligomeric phosphate ester (sol-DP), phosphazene(s) or a combination of at least two of the foregoing phosphorous based flame retardants.

[0092] Such flame retardants are known to the skilled person per se.

[0093] Preferably, the thermoplastic composition comprises at least 50 wt.%, more preferably at least 70 wt.%, at least 90 wt.% or at least 95 wt.%, based on the weight of the phosphorous flame retardant, of bisphenol A di-phosphate.

[0094] The amount of phosphorous based flame retardant is preferably from 10 to 14 wt.%, based on the weight of thermoplastic composition.

[0095] Other than the phosphorous based flame retardant the thermoplastic composition does not comprise any other flame retardant.

[0096] The flame retardant of the invention may comprise phosphazene. Thus, the phosphorous flame retardant preferably comprises from 0 to 60 wt.%, based on the weight of the phosphorous based flame retardant, of phosphazene. More preferably the amount of phosphazene is from 5 to 50 wt.%, or 20 to 40 wt.%. Notwithstanding the foregoing the amount of phosphazene in the thermoplastic composition is preferably from 0.5 to 1024POLYOQ81-WO-ORD 13

[0097] wt.%, based on the weight of thermoplastic composition. Preferably the amount of phosphazene is from 1 to 7 wt.%, more preferably from 1 to 5 wt.%. Since phosphazenes, at present, are relatively expensive materials and moreover affect the heat resistance properties a the thermoplastic composition the thermoplastic composition in accordance with the invention may be free from phosphazene.

[0098] The present invention is not strictly limited to any particular kind of phosphazene compound. Phosphazene compounds are commercially available and known to the skilled person per se.

[0099] It is however an important aspect of the present invention that the amount of phosphazene flame retardant (also referred to as phosphazene) in the thermoplastic composition is kept as low as possible in order not to affect other properties of the thermoplastic composition such as in particular the heat resistance in terms heat deflection temperature and / or Vicat softening temperature, or mechanical properties.

[0100] The phosphazene may be a halogenated phosphazene compound, having the following structure

[0101] (12)

[0102]

[0103] where R8, R10 and R12 can be the same of different and can independently be a hydrogen, a halogen, an aryl group, an aralkyl group, a C1-12 alkoxy, a C1-12 alkyl, a C1-12 haloalkyl or a combination thereof.24POLYOQ81-WO-ORD 14

[0104] An exemplary phenoxyphosphazene is a halogenated phenoxyphosphazene such as trifluorophenoxyphosphazene having the structure:

[0105] (13)

[0106]

[0107] A useful commercially available trifluorophenoxyphosphazene is F - PhZ commercially available from Cenway Tech under the brand name is CWFR - TFTP.

[0108] For the avoidance of doubt and for the purpose of the present invention the structures above, where the fluor atom is bonded to a phosphor atom is not considered as PFAS.

[0109] The phosphazene may however be free of halogen atoms.

[0110] The phosphazene is preferably a cyclic phosphazene, more preferably selected from the group consisting of propoxyphosphazene, phenoxyphosphazene, methylphenoxyphosphazene, aminophosphazene and fluoroalkylphosphazenes. The phosphazenes preferably has the structure of formula 14 below.

[0111]

[0112] 24POLYOQ81-WO-ORD 15

[0113] wherein Ri to R6can be the same or different and can be

[0114] - an aryl group,

[0115] - an optionally substituted aralkyl group,

[0116] - a C1-12 alkyl group, preferably methyl, ethyl, propyl or butyl,

[0117] - C5- to C6-cycloalkyl which is in each case optionally substituted by alkyl, preferably CM alkyl,

[0118] - a hydrogen

[0119] and k is an integer from 1 to 10, preferably from 1 to 8, more particular preferable from 1 to 5.

[0120] Preferably the cyclic phosphazene has a proportion of oligomers having k=1 (trimer) from 50 to 98 mol % preferably from 70 to 90 mol % and more preferably 70-85 mol %. More preferably, the phosphazene is phenoxyphosphazene having the structure of formula 15 below (all radicals Ri - R6are a phenyl group), having a proportion of oligomers having k=1 of at least 50 mol%, preferably at least 80 mol%, more preferably at least 98 mol% , or within a range of from 50 to 98 mol%.

[0121] (15)

[0122]

[0123] In a preferred aspect, the proportion of tetramers (k=2) is from 2 to 50 mol %, based on the amount of cyclic phosphazene, preferably from 5 to 40 mol %.24POLY0081-WO-ORD 16

[0124] In another aspect, the proportion of the higher oligomeric phosphazenes (k=3 -10 or 3-8 or 3-5, depending on the selection for k) is from 0 to 30 mol %, preferably from 2 to 25 mol % based on the amount of cyclic phosphazene.

[0125] The proportion of oligomers having k > 8 is from 0 to 2 mol %, based on the amount of cyclic phosphazene, preferably from 0.1 to 1 mol %.

[0126] Most preferably, the cyclic phosphazene substantially consists or consists of phenoxyphosphazene wherein k is at most 8 and having a proportion of trimer (k=1) of from 70 to 85 mol %, a proportion of tetramer (k=2) of from 10 to 20 mol %, a proportion of higher oligomeric phosphazenes (k=3-, 4, 5, 6 and 7) of from 5 to 15 mol %, wherein the total of cyclic phosphazenes wherein k is at most 8 is 100 mol%. In this respect the term “substantially consists” means that an amount of cyclic phosphazenes wherein k is more than 8 is at most 2 mol %.

[0127] R1 to R6 in formula (14) above may comprise one or more halogen atoms.

[0128] Commercially available phenoxy-phosphazenes include Rabitle FP110 and Rabitle FP 110-T manufactured by FUSHIMI Pharmaceutical Co., Ltd. Rabitle FP110 is free of halogen and antimony.

[0129] It is however preferred that the phosphazene does not contain any halogen substituents. In particular, the phosphazene and in particular the phosphazene of formula I above is preferably free of fluor substituents.

[0130] For the avoidance of doubt it is noted that phosphorous based flame retardant (C) may comprise a mixture of flame retardants.

[0131] The flame retardant preferably does not contain a flame retardant salt.

[0132] The flame retardant, and accordingly the thermoplastic composition preferably do not comprise a sulphone or a sulphone sulphonate, such as salts of a sulphone or sulphone sulphonate.24POLY0081-WO-ORD 17

[0133] Anti-drip agent (D)

[0134] Anti-drip agents known in the art can be used for further enhancing the flame retardancy of the thermoplastic composition of the present invention. Typically, the anti-drip agent is poly-tetrafluoroethylene, or compositions comprising poly-tetrafluoroethylene, such as in particular poly-tetrafluoroethylene dispersed in, encapsulated by or otherwise comprised in a styrene-acrylonitrile copolymer, such materials being generally known as TSAN. The amount of anti-drip agent is from 0.05 to 1 wt.%, preferably from 0.1 to 0.8 wt.% with 0.2 to 0.6 wt.% being particularly preferred.

[0135] Styrene-acrylonitrile copolymer (E)

[0136] The thermoplastic composition of the invention may comprises styrene-acrylonitrile copolymer, which is typically added to improve the flowability of the composition. The amount of styrene-acrylonitrile copolymer is preferably at most 5 wt.%, such as from 0.1 to 3 wt.% or .05 to 2.5 wt.%.

[0137] The styrene-acrylonitrile copolymer may have a melt flow rate of from 1 to 20 g / 10min, preferably 2 to 15 g / min, more preferably 4 to 10 g / 10min (ISO 1133, 190°C, 2.16 kg), a styrene content of from 10 to 50 wt.% and an acrylonitrile content of from 90 to 50 wt.%, based on the weight of the copolymer. A suitable styrene-acrylonitrile copolymer is available from SABIC as CYCOLAC INP576, having a melt flow rate in the range of about of about 5 ~ 10 g / 10min.

[0138] Further components (F)

[0139] The thermoplastic composition may comprise further components including, but not strictly limited to anti-oxidants, thermal stabilizers, mold release agents, UV stabilizers, anti-static agents, pigments and / or dyes. Preferably the amount of further components (F) is at most 3, preferably at most 2, more preferably at most 1.5 or 1 wt.%. In an embodiment the thermoplastic composition comprises at least one type of further component (F). In the context of the present invention the term “further components” may be replaced with the term “additives”, both terms have the same meaning.

[0140] Typically the further components have no or at least no significant influence on the key properties of the thermoplastic composition in terms of impact properties and flame24POLYOQ81-WO-ORD 18

[0141] retardancy. For example, the further components (F) do not comprise glass fibers, flame retardants or impact modifiers.

[0142] Composition and method of manufacture

[0143] Except for the anti-dripping agent it is preferred that the thermoplastic composition of the invention does not comprise any halogen containing compounds.

[0144] Preferably the composition of the invention has or is selected to have a UL94 flame retardancy rating of VO or V1 at 1.2mm, preferably VO at 1.2mm.

[0145] Preferably the composition of the invention has or is selected to have a notched Izod impact resistance of at least 400 J / m determined in accordance with ASTM 256 at 25°C.

[0146] Preferably the composition of the invention has, or is selected to have, a heat deflection temperature (HDT) of at least 80°C, preferably at least 85 °C as determined in accordance with ASTM D648, flatwise, measured on injection molded samples of 3.2 mm thickness and under a load of 1.8 Mpa.

[0147] The composition of the present invention preferably has as a melt volume rate of from 4 to 20 cm3 / 10 min, preferably from 6 to 16, more preferably 7.5 to 15 cm3 / 10 min, determined in accordance with ASTM D1238 (260°C, 2.16kg).

[0148] Other than the anti-drip agent, the composition of the invention is preferably halogen free. The composition of the invention preferably does not comprise a polysiloxane or a polycarbonate-polysiloxane copolymer. The composition of the invention preferably does not comprise one or more of talc, kaolin, mica, clay, wollastonite, bentonite and mixtures of at least two of the foregoing.

[0149] Preferably, the composition has or is selected to have a notched Izod impact resistance of at least 400 J / m, preferably at least 500 J / m, more preferably at least 600 J / m, determined in accordance with ASTM 256 at 25°C.

[0150] Application24POLY0081-WO-ORD 19

[0151] An article comprising or consisting of the composition as disclosed herein can be manufactured using any know technique such as extrusion moulding, injection moulding, blow moulding, thermoforming etc.

[0152] The thermoplastic composition in accordance with the invention is particularly suited for the manufacture of articles that are comprised in or consists of the housing of electric or electronic parts, preferably consumer electronic devices, charging equipment for electrical vehicles or smart meters. For example, the thermoplastic composition of the invention may be used for the manufacture of parts of mobile phones, tablets, chargers for mobile phones or tablets, televisions, computer monitors, laptop computers, desktop computers, printers, scanners, pro audio equipment like mixing desks, guitar modelers and the like. Alternatively the thermoplastic composition may be used for the manufacture of articles comprised in or constituting interior automotive applications.

[0153] The present invention will now be further elucidated on the basis of the following nonlimiting examples.

[0154] Table 1 shows the materials being used in the experiments.

[0155] Table 1

[0156] PC-1 Bisphenol A polycarbonate homopolymer manufactured with an (PC- 105) interfacial process having MVR of 6 cm3 / 10 min (300°C, 1.2 kg). PC-2 Bisphenol A polycarbonate homopolymer manufactured with an (PC- 175) interfacial process having MVR of 26 cm3 / 10 min (300°C, 1.2 kg)- PC-3 Bisphenol A polycarbonate homopolymer manufactured with a (PC-102L) melt transesterification process having an MVR of 6 cm3 / 10 min (300°C, 1.2 kg)

[0157] PC-4 Bisphenol A polycarbonate homopolymer manufactured with a (PC-172L) melt transesterification process and having MVR of 28 cm3 / 10 min (300°C, 1.2 kg).

[0158] PC-5 Bisphenol A polycarbonate homopolymer manufactured with a (PC-0700) melt transesterification process and having a MVR of 7 cm3 / 10 min (300°C, 1.2 kg).

[0159]

[0160] 24POLY0081-WO-ORD 20

[0161] PC-6 Bisphenol A polycarbonate homopolymer manufactured with a (PC-2200) melt transesterification process and having a MVR of 24 cm3 / 10 min (300°C, 1.2 kg).

[0162] ABS_1 ABS available in pellet from SABIC with 15-20 wt.% polybutadiene content (CAS# 9003-56-9)

[0163] ABS_2 ABS commercially available from INEOS as TERLURAN GP-22, having a polybutadiene content of about 22 wt.%

[0164] ABS_3 ABS commercially available from Bhansali Engg as GA-108, having a butadiene content of about 20 wt.% ABS_4 Emulsion-ABS from SABIC having a polybutadiene content of about 55-65% butadiene content (CAS# 9010-94-0) SAN_1 Styrene-Acrylonitrile copolymer having a MVR of 5~10 cm3 / 10 (SAN-576) min (230C, 1.2 kg), a styrene content of about 75 wt.% and acrylonitrile content of about 25 wt.%, (CAS# 9003-54-7) SAN_2 Styrene- acrylonitrile copolymer having a MVR of 50 cm3 / 10 min (230°C, 1.2 kg) ), a styrene content of about 75 wt.% and acrylonitrile content of about 25 wt.%.

[0165] FR Phosphoric acid, (1-methylethylidene)di-4,1 -phenylene (BPADP) tetraphenyl ester (available from Wangsheng, CAS# 5945-33-5) MR Pentaerythritol tetrastearate (CAS# 115-83-3)

[0166] (PETS)

[0167] STAB-1 Tetrakis methylene (3, 5-di-tert-butyl-4-hydroxyhydro cinnamate) (Irganox 1010) methane (available from BASF, CAS# 6683-19-8)

[0168] STAB-2 Tris(2,4-di-t-butylphenyl)phosphite (available from BASF, CAS# (Irgaphos 168) 31570-04-4)

[0169] UV 2-(2 hydroxy-5-t-octylphenyl) benzotriazole (available from ( UV- 5411 ) Cytec, CAS# 3147-75-9)

[0170] TSAN SAN encapsulated PTFE (available from SABIC, CAS# 9003-54- (TSAN) 7 and 9002-84-0) with a PTFE content of 50 wt.%

[0171] FP Ethylene bis(stearamide) (CAS# 110-30-5)

[0172] (EBS)

[0173]

[0174] The compositions of the following Examples and Comparative Examples were extruded on a Werner Pfleiderer 25 / 26 mm co-rotating intermeshing twin-screw extruder having a24POLYOQ81-WO-ORD 21

[0175] length over diameter ratio (L / D) of 41. The components were added at the feed throat of the extruder and extruded with barrel temperatures set at a temperature profile: 100-150-220-240-250-250-250-260-260-260-265° C. The extruder screw speed was set at 300 rpm while maintaining torque of 64- 68%. A vacuum of about 100 - 800 millibar (10 -80 kPa) was applied during the extrusion step.

[0176] Test samples were injection molded with the molding machine set from 80-240-250-260-255 °C and a mold temperature of 70 °C.

[0177] The following test methods were used

[0178] Table 2

[0179] Notched Izod Impact (Nil) ASTM D256; measured at 25°C on injection molded samples 63.5 x 12.7 x 3.2 mm having a notch of 2mm. The reported value is the average of 5 measurements.

[0180] Heat distortion temperature ASTM D648, flatwise on samples of 3.2 mm (HDT) thickness and a load of 1.8 Mpa

[0181] Melt Flow Rate (MFR) Unless specifically defined otherwise the MFR or Melt Volume Rate (MVR) MVR was determined in accordance with ASTM D1238 at 260 °C at a load of 2.16 kg.

[0182] Endcap level (EC%) and The endcap level can be determined based on UV hydroxyl content measurement to determine the amount of terminal OH groups. Combined with the number average molecular weight the endcap level is then determined in accordance with Formula I. The UV spectrophotometer is a Perkin Elmer Lambda 800. Measurements are carried out on 0.01g of a polycarbonate sample dissolved in 10 ml of dichloromethane and placed into a quartz cuvette of 10 mm of optical path. The wavelength to acquire data are 284 and 292 nm. The results from the equipment as ppm of OH are used to calculate the endcap using also the molecular weight of the

[0183]

[0184] 24POLY0081-WO-ORD 22

[0185] polycarbonate and according to the formula for calculation as disclosed herein. Polycarbonate(s) with known amount(s) of terminal OH groups are used as standards for the UV measurements.

[0186] Flame retardancy UL-94 vertical burning test at the indicated thickness

[0187]

[0188] Tables 3a - 3e below show the results of several compositions that were tested.

[0189] Table 3a

[0190] CE1 CE2 CE3

[0191] PC-1 [wt.%] 36

[0192] PC-2 [wt.%] 32.4 10 10

[0193] PC-3 [wt.%] 36 36

[0194] PC-4 [wt.%] 22.4 22.4

[0195] ABS_1 [wt.%] 18 18

[0196] ABS_2 [wt.%] 18

[0197] FR [wt.%] 12.25 12.25 12.25

[0198] MR [wt.%] 0.5 0.5 0.5

[0199] STAB-1 [wt.%] 0.08 0.08 0.08

[0200] STAB-2 [wt.%] 0.08 0.08 0.08

[0201] UV [wt.%] 0.04 0.04 0.04

[0202] TSAN [wt.%] 0.65 0.65 0.65

[0203] MVR [cm3 / 10min] 16.3 16.3 18.1

[0204] Nil [J / m] 443 130 85

[0205] UL-94 @ 1.5mm VO VO VO

[0206] UL-94 @1.2mm V2 V2 V2

[0207] HDT [°C] 81 81 82

[0208]

[0209] Table 3a shows that compositions based on bulk ABS, i.e. ABS with a relatively low amount of polybutadiene and loaded with about 12 wt.% of flame retardant and an anti-24POLY0081-WO-ORD 23

[0210] drip agent show good flame retardancy at a thickness of 1.5mm, but poor performance at 1.2mm. This behaviour is observed for both melt polycarbonate rich as well as interfacial polycarbonate based formulations.

[0211] Table 3b

[0212] E1 E2 E3 E4 E5 E6 E7 E8 PC-1 [wt.%] 32.4 32.4

[0213] PC-2 [wt.%] 10 10 42.5 47.3 10 10 10 10 PC-3 [wt.%] 48.5 38.5 32.4 32.4

[0214] PC-4 [wt.%] 22.4 32.4 37.5 37.3

[0215] PC-5 [wt.%] 32.4 32.4 PC-6 [wt.%] 37.5 37 ABS_4 [wt.%] 5.5 5.5 6.5 6.5 6.5 6.5 6.5 7 SAN_1 [wt.%] 5

[0216] FR [wt.%] 12.25 12.25 12.25 12.25 12.25 12.25 12.25 12.25 MR [wt.%] 0.5 0.5 0.5 0.7 0.5 0.5 0.5 0.5 STAB-1 [wt.%] 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 STAB-2 [wt.%] 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 UV [wt.%] 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 TSAN [wt.%] 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 FP [wt.%] 0.2

[0217] MVR [cm3 / 10min] 14.8 14.3 13.8 12.2 13 14.6 11.4 13.1 Nil [J / m] 480 285 382 600 581 614 634 621 UL-94

[0218] @ 1.5mm VO VO VO VO VO VO VO VO UL-94

[0219] @1.2mm V0 / V1 V1 V0 / V1 VO VO VO VO VO HDT [°C] 86 86 87 88

[0220]

[0221] Table 3b shows the composition of several examples in accordance with the invention, most of which show a flame retardancy rating of VO at 1 ,2mm combined with good impact and acceptable melt flow properties. A key aspect of the invention is the use of emulsion based ABS (i.e. HRG-ABS) with a relatively high rubber content. A comparison between24POLY0081-WO-ORD 24

[0222] E3 and E4 shows that replacing a small portion of the polycarbonate with SAN enhances the melt flow properties of the composition, yet may result in slightly less robust flame retardancy rating. The impact properties of E2 are relatively low compared to the impact properties of E1. The inventors consider that this may be the result, at least in part, of the combination of a low amount of ABS and a higher amount of polycarbonate with a MVR of 26 cm3 / 10min.

[0223] Table 3c

[0224] CE4 CE5 CE6 CE7 CE8 CE9 PC-1 [wt.%] 29.4 29.4 29.4 32.4 29.4 36 PC-2 [wt.%] 39 38.9 37.9 40 40 38.4 ABS_1 [wt.%] 14 17 9 ABS_3 [wt.%] 18 18 18

[0225] ABS_4 [wt.%] 3 FR [wt.%] 12.25 12.25 13.25 12.25 12.25 12.25 MR [wt.%] 0.5 0.5 0.5 0.5 0.5 0.5 STAB-1 [wt.%] 0.08 0.08 0.08 0.08 0.08 0.08 STAB-2 [wt.%] 0.08 0.08 0.08 0.08 0.08 0.08 UV [wt.%] 0.04 0.04 0.04 0.04 0.04 0.04 TSAN [wt.%] 0.65 0.75 0.75 0.65 0.65 0.65

[0226] MVR [cm3 / 10min] 15.4 14.9 15.9 19.9 20.2 13.6 Nil [J / m] 88 103 74 90 90 168 UL-94 @ 1.5mm V1 V1 V1 V2 V1 VO UL-94 @1.2mm V1 V2 V2 V2 V2 VO HDT [°C] 82 80

[0227]

[0228] Table 3c shows, as Table 3a, that certain compositions based on bulk-ABS generally do not have sufficient flame retardancy properties, even at 1.5 mm. The table also shows that there is an influence of the types and amounts of (in particular) ABS and polycarbonate on the flame retardancy.24POLY0081-WO-ORD 25

[0229] Table 3d

[0230] E9 E10 E11 E12 E13 E14 E15 PC-2 [wt.%] 10 80.15 10 10 10 10

[0231] PC-3 [wt.%] 32.1

[0232] PC-4 [wt.%] 37.3 70.15 68.65 78.65 PC-5 [wt.%]

[0233] PC-6 [wt.%] 70.15 68.65 ABS_4 [wt.%] 6.5 7.5 7.5 7.5 7.5 7.5 7.5 SAN_1 [wt.%] 1.5 1.5 1.5 FR [wt.%] 12.25 11 11 11 11 11 11 MR [wt.%] 0.5 0.5 0.5 0.5 0.5 0.5 0.5 STAB-1 [wt.%] 0.08 0.08 0.08 0.08 0.08 0.08 0.08 STAB-2 [wt.%] 0.08 0.08 0.08 0.08 0.08 0.08 0.08 UV [wt.%] 0.04 0.04 0.04 0.04 0.04 0.04 0.04 TSAN [wt.%] 0.65 0.65 0.65 0.65 0.65 0.65 0.65 FP [wt.%] 0.5

[0234] MVR [cm3 / 10min] 14 16.6 16.7 14.8 17.6 16.2 19 Nil [J / m] 630 590 560 540 583 560 569 UL-94 @ 1.5mm VO VO VO VO VO VO VO UL-94 @1.2mm V1 VO VO VO VO VO VO HDT [°C] 85 85 86 85 86

[0235]

[0236] Table 3d shows further compositions in accordance with the invention, most of which have a flame retardancy rating of VO both at 1.5 as well as 1.2mm. Compared to CE1 the HDT is slightly higher, which is considered an improvement. As shown before, a small amount of additional SAN supports good melt flow properties while maintaining acceptable flame retardancy. While the formulation of E9 contains the highest amount of flame retardant, the flame retardancy at 1 ,2mm was found to be V1 rather than VO. Without willing to be strictly bound to it the inventors consider this can be the result of the presence of flow promotor. All examples are based on the use of emulsion type ABS (i.e. HRG-ABS) with a relatively high amount of polybutadiene.24POLY0081-WO-ORD 26

[0237] Table 3e

[0238] CE10 CE11 CE12

[0239] PC-1 [wt.%]

[0240] PC-2 [wt.%] 10 10 10

[0241] PC-3 [wt.%] 32.4 32.4 32.4

[0242] PC-4 [wt.%] 32.5 34.5 34.3

[0243] ABS [wt.%] 6.5 6.5 6.5

[0244] SAN_1 [wt.%] 5

[0245] SAN_2 [wt.%] 3 3

[0246] FR [wt.%] 12.25 12.25 12.25

[0247] MR [wt.%] 0.5 0.5 0.5

[0248] STAB-1 [wt.%] 0.08 0.08 0.08

[0249] STAB-2 [wt.%] 0.08 0.08 0.08

[0250] UV [wt.%] 0.04 0.04 0.04

[0251] TSAN [wt.%] 0.65 0.65 0.65

[0252] FP [wt.%] 0.2

[0253] MVR [cm3 / 10min] 13 14.5 14.7

[0254] Nil [J / m] 120 139 112

[0255] UL-94 @ 1.5mm VO VO VO

[0256] UL-94 @1.2mm V1 V2 VO

[0257] HDT [°C]

[0258]

[0259] Table 3e shows that a low molecular weight SAN improves the melt flow of the composition, yet that desired flame properties along with Impact properties (Nil) may not be obtained.

Claims

24POLYOQ81-WO-ORD 27C LA I M S1. Thermoplastic composition comprising, based on the weight of the composition, (A) from 75 to 85 wt.% of polycarbonate(B) from 4 to 12 wt.% of impact modifier,(C) from 8 to 16 wt.% of phosphorous based flame retardant,(D) from 0.2 to 1.5 wt.% of anti-drip agent,(E) from 0 to 6 wt.% of styrene-acrylonitrile copolymer,(F) from 0 to 3 wt.% of further componentswherein- the sum of the components (A) to (F) is 100 wt.%,- the composition has or is selected to have a UL94 flame retardancy rating of VO at 1.5mm- the composition has a melt volume rate of from 10 to 25 cm3 / 10 min as determined in accordance with ASTM D 1238 (260°C, 2.16 kg),- the impact modifier is a copolymer selected from the group consisting of acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-butadiene- styrene copolymer, styrene-butadiene-styrene copolymer, styrene-ethylene- butadiene-styrene copolymer, acrylonitrile-styrene-(butyl)acrylate copolymer, or mixtures of two or more of the foregoing impact modifiers, having a rubber content of from 55 to 70 wt.%, based on the weight of the copolymer(s), and - the phosphorous based flame retardant (C) comprises, based on the weight of the phosphorous based flame retardant, at least 90 wt.% of a compound selected from the group consisting of bisphenol A bis(diphenyl) phosphate, resorcinol bis(diphenyl) phosphate, triphenyl phosphate, phosphazene and mixtures of at least two of the foregoing.

2. The composition of claim 1 wherein the composition has or is selected to have a UL94 flame retardancy rating of V0 or V1 at 1.2mm, preferably V0 at 1.2mm.24POLYOQ81-WO-ORD 283. The composition of claim 1 or 2 wherein the composition has or is selected to have a notched Izod impact resistance of at least 400 J / m determined in accordance with ASTM 256 at 25°C.

4. The composition of any one or more of claims 1 - 3 wherein the composition has, or is selected to have, a heat deflection temperature (HDT) of at least 80°C, preferably at least 85 °C as determined in accordance with ASTM D648, flatwise, measured on injection molded samples of 3.2 mm thickness and under a load of 1.8 Mpa.

5. The composition of any one or more of claims 1 - 4 wherein the phosphorous based flame retardant is bisphenol A bis(diphenyl) phosphate.

6. The composition of any one or more of claims 1 - 5 wherein the polycarbonate (A) comprises at least 90 wt.%, preferably at least 95 wt.%, more preferably at least 99 wt.% of bisphenol A polycarbonate homopolymer, based on the weight of the polycarbonate.

7. The composition of any one or more of claims 1 - 6 wherein the polycarbonate (A) is a mixture of two or more polycarbonates, wherein said two or more different polycarbonates differ in either type or in melt volume rate, said type being melt polycarbonate or interfacial polycarbonate.

8. The composition of any one or more of claims 1 - 7 wherein the polycarbonate (A) consists of a mixture of at least one interfacial bisphenol A polycarbonate homopolymer and at least one melt bisphenol A polycarbonate homopolymer.

9. The composition of claim 8 wherein the mixture consists of 5 to 20 wt.% of interfacial bisphenol A polycarbonate homopolymer and of 95 to 80 wt.% of melt bisphenol A polycarbonate homopolymer, based on the weight the polycarbonate.

10. The composition of any one or more of claims 1 - 9 wherein the styrene-acrylonitrile copolymer (E) has melt volume rate of from 1 to 20 cm3 / 10min, preferably from 2 to 15 cm3 / 10min, more preferably from 2 to 10 cm3 / 10 min determined in accordance with ASTM D1238 (230°C, 1.2 kg).24POLYOQ81-WO-ORD 2911. The composition of any one or more of claims 1 - 10 wherein the impact modifier (B) comprises at least 90 wt.%, more preferably at least 95 wt.%, most preferably at least 99 wt.%, based on the weight of the impact modifier (B), of acrylonitrile-butadiene- styrene copolymer having a polybutadiene rubber content of from 55 to 70 wt.%, based on the weight of the acrylonitrile-butadiene-styrene copolymer.

12. The composition of any one or more of claims 1 - 11 wherein the further components (F) comprise one or more of a anti-oxidant, heat stabiliser, UV absorber, mold release agent, flow promotor, colorants, fillers.

13. The composition of any one or more of claims 1 - 12 wherein the anti-drip agent (D) comprises poly-tetrafluoroethylene and is preferably poly-tetrafluoroethylene encapsulated by styrene-acrylonitrile copolymer.

14. An article comprising or consisting of the composition of any one or more of claims 1 - 13.

15. The article of claim 14, wherein said article is comprised in or constitutes an electrical vehicle or an electrical or electronic device.

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