Flame retardant composition

Abstract

The present invention relates to an impact modified polycarbonate based composition which has or is selected to have a UL94 flame retardancy rating of V1 or V0 at 1.2mm.

Description

[0001] 24POLY0133-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. Many of such compositions are based on the use of ABS made with a bulk-polymerisation process. These ABS grades typically have a low rubber content which requires that more ABS is needed to obtain the desired properties. However, under application of a higher amount of such bulk-ABS it becomes more difficult to obtain good flame retardancy properties, in particular at low thickness.

[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 the24POLY0133-WO-ORD 2

[0008] 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).

[0009] 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.

[0010] It is an object of the invention to provide for an impact modified polycarbonate composition that combines good impact properties with sufficient flame retardancy at low thickness.

[0011] To that extent the present invention relates a thermoplastic composition comprising, based on the weight of the composition,

[0012] (A) from 55 to 70 wt.% of polycarbonate

[0013] (B) from 12 to 25 wt.% of impact modifier

[0014] (C) from 8 to 16 wt.% of phosphorous based flame retardant,

[0015] (D) from 0.2 to 1.5 wt.% of anti-drip agent,

[0016] (E) from 1 to 7 wt.% of polycarbonate-polysiloxane block copolymer,

[0017] (F) from 0.1 to 3 wt.% of a flame retardant synergist selected from the group consisting of talc, kaolin, mica, wollastonite, bentonite and mixtures of at least two of the foregoing,

[0018] (G) from 0 to 5 wt.% of further components

[0019] wherein

[0020] the sum of the components (A) - (G) is 100 wt.%,

[0021] the composition has or is selected to have a UL94 flame retardancy rating of V1 or V0 at 1.2mm,

[0022] 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 15 to 30 wt.%, based on the weight of the impact modifier.24POLY0133-WO-ORD 3

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

[0024] (A) from 55 to 70 wt.% of polycarbonate

[0025] (B) from 12 to 25 wt.% of acrylonitrile-butadiene-styrene copolymer having a polybutadiene rubber content of from 15 - 30 wt.%, based on the weight of the acrylonitrile-butadiene-styrene copolymer (B),

[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 1 to 7 wt.% of polycarbonate-polysiloxane block copolymer,

[0029] (F) from 0.1 to 3 wt.% of a flame retardant synergist selected from the group consisting of talc, kaolin, mica, wollastonite, bentonite and mixtures of at least two of the foregoing,

[0030] (G) from 0 to 5 wt.% of further components

[0031] wherein,

[0032] - the sum of the components (A) to (G) is 100 wt.%,

[0033] - the composition has or is selected to have a UL94 flame retardancy rating of V1 or V0 at 1.2mm.

[0034] 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.

[0035] Polycarbonate (A)

[0036] 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).24POLY0133-WO-ORD 4

[0037] 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.

[0038] 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.

[0039] 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. More in particular it is preferred that the polycarbonate (A) comprises at least 80 wt.% of interfacial polycarbonate, based on the weight of the polycarbonate (A).

[0040] Nonetheless, 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 I

[0041] ppmOH X Mn

[0042] %EC = 100 - . 340000

[0043]

[0044] 24POLY0133-WO-ORD 5

[0045] 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.

[0046] 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%.

[0047] 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, preferably at most 1 ppm.

[0048] 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.

[0049] 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.24POLY0133-WO-ORD 6

[0050] 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).

[0051] 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.

[0052] 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

[0053] 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 20 g / 10min, more preferably from 5.0 to 12 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.

[0054] The amount of polycarbonate in the composition is preferably from 60 to 65 wt.%.

[0055] 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 during24POLY0133-WO-ORD 7

[0056] the polymerisation process, branched polycarbonate is not to be considered as a copolymer merely because it contains some groups originating from a branching agent.

[0057] Preferably the amount of branched polycarbonate is from 1 to 60 wt.%, preferably 5 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.

[0058] 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)

[0059] (1)

[0060]

[0061] wherein Z is a halogen, C1-3 alkyl, C1-3 alkoxy, C7-12 arylalkylene, C7-12 alkylarylene, and z is 0 to 3;

[0062] a trisubstituted phenol of formula (2)

[0063] (2)

[0064]

[0065] OH24POLY0133-WO-ORD 8

[0066] 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;

[0067] ora compound of formula (3) (isatin-bis-phenol).

[0068]

[0069] 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.

[0070] 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.

[0071] 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.

[0072] A combination of two or more branching agents may be used.

[0073] 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.24POLY0133-WO-ORD 9

[0074] 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.%.

[0075] 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.

[0076] 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).

[0077] 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.

[0078] Impact modifier (B)

[0079] 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. The rubber content of the impact modifier (B) is from 15 to 30 wt.%, preferably from 18 to 26 wt.%. If the impact modifier consists of acrylonitrile-butadiene-styrene copolymer then the polybutadiene rubber content is from 15 to 30 wt.%, preferably from 18 to 26 wt.%.

[0080] Preferably the impact modifier comprises or consists of acrylonitrile-butadiene-styrene copolymer. Thus, the amount of acrylonitrile-butadiene-styrene copolymer in impact24POLY0133-WO-ORD 10

[0081] modifier (B) 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. For the avoidance of doubt, the impact modifier may comprise or consist of one type of acrylonitrile-butadiene-styrene copolymer or of two or more types of acrylonitrile-butadiene-styrene copolymer, wherein the copolymers differ in properties and / or chemical composition. For example, the acrylonitrile-butadiene-styrene copolymers may differ in rubber content, styrene to acrylonitrile molar ratio, melt volume rate etc.

[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.

[0083] Preferably the impact modifier (B) comprises or consists of acrylonitrile-butadiene-styrene copolymer, in particular b-ABS or a mixture of b-ABS and HRG-ABS with a minor amount of HRG-ABS.

[0084] The impact modifier has a rubber content of from 15 - 30 wt.%, based on the weight of the impact modifier. The impact modifier (B) may be a mixture of several copolymers with mutually different rubber contents, provided that the total rubber content is from 15 to- 30 wt.%.

[0085] Preferably, the impact modifier comprises at least 80 wt.%, preferably at least 90 wt.%, more preferably at least 99 wt.%, based on the weight of the impact modifier, of acrylonitrile-butadiene-styrene copolymer. For the avoidance of doubt, this acrylonitrile-24POLY0133-WO-ORD 11

[0086] butadiene-styrene copolymer can be a single acrylonitrile-butadiene-styrene copolymer or a mixture of mutually different acrylonitrile-butadiene-styrene copolymers.

[0087] The acrylonitrile-butadiene-styrene copolymer may consists of a mixture of

[0088] at least one first acrylonitrile-butadiene-styrene copolymer having a polybutadiene rubber content of from 40 to 70 wt.%, preferably 50 to 65 wt.%, more preferably 55 to 65 wt.%, based on the weight of said of acrylonitrile-butadiene-styrene copolymer, and

[0089] at least one second acrylonitrile-butadiene-styrene copolymer having a polybutadiene rubber content of from 15 to 25 wt.% based on the weight of said of acrylonitrile-butadiene-styrene copolymer, provided the total rubber content in the impact modifier is from 15 to 30 wt.% based on the weight of the impact modifier. If the impact modifier consists of acrylonitrile-butadiene-styrene copolymer then the total rubber content, i.e. the total polybutadiene rubber content, is from 15 to 30 wt.%, based on the weight of the acrylonitrile-butadiene-styrene copolymer.

[0090] Thus, the acrylonitrile-butadiene-styrene copolymer may be mixture of b-ABS and HRG-ABS, provided the total rubber content in the impact modifier is from 15 to 30 wt.% based on the weight of the impact modifier.

[0091] The impact modifier (B) may also 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.

[0092] It is preferred that the amount of free styrene-acrylonitrile copolymer in the acrylonitrile-butadiene-styrene 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 acrylonitrile-butadiene-styrene copolymer.

[0093] The amount of styrene and acrylonitrile in the acrylonitrile-butadiene-styrene copolymer may vary such that the styrene to acrylonitrile molar ratio is from 90:10 to 60:40.24POLY0133-WO-ORD 12

[0094] The melt volume rate (MVR) of the impact modifier (B) is preferably from 15 to 30 cm3 / 10min as determined in accordance with ISO 1133 (220°C, 10 kg). Preferably the melt volume rate is from 18 to 25 cm3c / 10min.

[0095] The melt volume rate (MVR) of the acrylonitrile-butadiene-styrene copolymer (B) is preferably from 15 to 30 cm3 / 10min as determined in accordance with ISO 1133 (220°C, 10 kg). Preferably the melt volume rate is from 18 to 25 cm3 / 10min.

[0096] The impact modifier may comprise or consist of recycled impact modifier, in particular recycled 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).

[0097] The acrylonitrile-butadiene-styrene copolymer may comprise or consist of recycled acrylonitrile-butadiene-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).

[0098] Phosphorous-based flame retardant (C)

[0099] 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.

[0100] Such flame retardants are known to the skilled person per se.

[0101] 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.

[0102] The phosphorous based flame retardant (C) may be a mixture of bisphenol A diphosphate (BPADP) and solid oligomeric phosphate ester (sol-DP), or a mixture of bisphenol A di-phosphate (BPADP) and phosphazene(s), wherein the amount of bisphenol A di-phosphate (BPADP) is at least 55 wt.%, based on the weight of the phosphorous based flame retardant (C).24POLY0133-WO-ORD 13

[0103] The amount of phosphorous based flame retardant is preferably from 10 to 14 wt.%, based on the weight of thermoplastic composition.

[0104] Other than the phosphorous based flame retardant the thermoplastic composition does not comprise any other flame retardant.

[0105] 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.%, 10 to 45 wt.% or 15 to 40 wt.%.

[0106] The amount of phosphazene in the thermoplastic composition is preferably from 0.5 to 10 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.%. The amount of phosphazene may be at most 3 wt.%.

[0107] 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.

[0108] 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.

[0109] The phosphazene may be a halogenated phosphazene compound, having the following structure24POLY0133-WO-ORD 14

[0110]

[0111] 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.

[0112] An exemplary phenoxyphosphazene is a halogenated phenoxyphosphazene such as trifluorophenoxyphosphazene having the structure:

[0113] (13)

[0114]

[0115] A useful commercially available trifluorophenoxyphosphazene is F - PhZ commercially available from Cenway Tech under the brand name is CWFR - TFTP.

[0116] 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.24POLY0133-WO-ORD 15

[0117] The phosphazene may however be free of halogen atoms.

[0118] 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.

[0119] (14)

[0120]

[0121] wherein Ri to R6can be the same or different and can be

[0122] - an aryl group,

[0123] - an optionally substituted aralkyl group,

[0124] - a C1-12 alkyl group, preferably methyl, ethyl, propyl or butyl,

[0125] - C5- to C6-cycloalkyl which is in each case optionally substituted by alkyl, preferably CM alkyl,

[0126] - a hydrogen

[0127] and k is an integer from 1 to 10, preferably from 1 to 8, more particular preferable from 1 to 5.

[0128] 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 R1 - 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 -98 mol%.24POLY0133-WO-ORD 16

[0129] (15)

[0130]

[0131] 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 %.

[0132] 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.

[0133] 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 %.

[0134] 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 %.

[0135] R1 to R6 in formula (14) above may comprise one or more halogen atoms.

[0136] 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.24POLY0133-WO-ORD 17

[0137] 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.

[0138] For the avoidance of doubt it is noted that phosphorous based flame retardant (C) may comprise a mixture of flame retardants.

[0139] The flame retardant preferably does not contain a flame retardant salt.

[0140] 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.

[0141] Anti-drip agent (D)

[0142] 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 - 0.6 wt.% being particularly preferred.

[0143] Polycarbonate-polysiloxane copolymer (E)

[0144] The thermoplastic composition comprises from 0 to 7 wt.%, preferably 1 to 7 wt.%, more preferably 3 to 6 wt.% of polysiloxane-polycarbonate copolymer (PC-POS), based on the weight of the thermoplastic composition. The presence of PC-POS is preferred as such materials not only improve the flame retardancy but als result in improved impact properties. The present inventors found that PC / ABS composition based on bulk ABS and having a V0 rating at 1.2 mm may be obtained in absense of a polycarbonate-polysiloxane copolymer. Preferably though a polycarbonate-polysiloxane copolymer is present in the thermoplastic composition.

[0145] The polydiorganosiloxane (also referred to herein as "polysiloxane") blocks of the copolymer comprise repeating diorganosiloxane units as in formula (4)24POLY0133-WO-ORD 18

[0146] R

[0147] — SiO" (4)

[0148] I R

[0149] E

[0150]

[0151] wherein each R is independently a C1-13 monovalent organic group. For example, R can be a C1-13 alkyl, C1-13 alkoxy, C2-13 alkenyl group, C2-13 alkenyloxy, C3-6 cycloalkyl, C3-6 cycloalkoxy, C6-14 aryl, C6-io aryloxy, C7-13 arylalkyl, C7-13 aralkoxy, C7-13 alkylaryl, or C7-13 alkylaryloxy.

[0152] Combinations of the foregoing R groups can be used in the same copolymer.

[0153] The value of E in formula (4) can vary depending on the type and relative amount of each component in the flame retardant composition, the desired properties of the composition, and like considerations. Generally, E has an average value of 2 to 1,000, specifically 3 to 500, more specifically 5 to 100. In an embodiment, E has an average value of 10 to 75, and in still another embodiment, E has an average value of 40 to 60. Where E is of a lower value, e.g., less than 40, it can be desirable to use a relatively larger amount of the polycarbonate-polysiloxane copolymer. Conversely, where E is of a higher value, e.g., greater than 40, a relatively lower amount of the polycarbonate-polysiloxane copolymer can be used.

[0154] In accordance with the present invention the polycarbonate-polysiloxane copolymer has a polysiloxane content of at least 12 wt.%, such as from 15 to 55 wt.%, preferably from 15 to 35 wt.%, 15 to 30 wt.% or 18 to 25 wt.% and based on the weight of the blockcopolymer. While the polysiloxane content may be from 30 to 50 wt.% it is preferred that the polysiloxane content is at most 30 wt.%, preferably at most 25 wt.% as otherwise the copolymer may be less compatible with the polycarbonate (A). A reduced compatibility may result in phase separation and less favourable color properties of the thermoplastic composition. The polycarbonate-polysiloxane block copolymer may have a weight average molecular weight (Mw) of from about 26,000 to about 35,000 g / mol24POLY0133-WO-ORD 19

[0155] For the avoidance of doubt it is to be understood that the term polysiloxane content and siloxane content in the copolymer have the same meaning.

[0156] A combination of a first and a second (or more) polycarbonate-polysiloxane copolymers can be used, wherein the average value of E of the first copolymer is less than the average value of E of the second copolymer.

[0157] In an embodiment, the polysiloxane blocks are of formula (5)

[0158] (5)

[0159]

[0160] wherein E is as defined above; each R can be the same or different, and is as defined above; and Ar can be the same or different, and represents the bisphenol units used for the manufacture of the polycarbonate-polysiloxane copolymer. Typically Ar represents units originating from bisphenol A. That is, Ar groups in formula (5) can be derived from a C6-3o dihydroxyarylene compound, for example 1, 1-bis(4-hydroxyphenyl) methane, 1, 1-bis(4-hydroxyphenyl) ethane, 2,2-bis(4-hydroxyphenyl) propane, 2,2-bis(4-hydroxyphenyl) butane, 2,2-bis(4-hydroxyphenyl) octane, 1,1-bis(4-hydroxyphenyl) propane, 1,1-bis(4-hydroxyphenyl) n-butane, 2,2-bis(4-hydroxy-1 -methylphenyl) propane, 1, 1-bis(4-hydroxyphenyl) cyclohexane, bis(4-hydroxyphenyl sulfide), and 1, 1-bis(4-hydroxy-t-butylphenyl) propane. Combinations comprising at least one of the foregoing dihydroxy compounds can also be used.

[0161] The polysiloxane blocks in the copolymer may be of formula (6)

[0162] (6)

[0163]

[0164] wherein Rand E are as described above, and each R5 is independently a divalent C1-30 organic group.24POLY0133-WO-ORD 20

[0165] The polymerised polysiloxane unit is the reaction residue of its corresponding dihydroxy compound. The polysiloxane blocks may be of formula (7):

[0166]

[0167] wherein R and E are as defined above. R6in formula (7) is a divalent C2-8 aliphatic group. Each M in formula (7) can be the same or different, and can be a cyano, nitro, Ci.8alkylthio, Ci.8alkyl, Ci-8alkoxy, C2.8alkenyl, C2.8alkenyloxy group, C3.8cycloalkyl, C3.8cycloalkoxy, C6-io aryl, C6-io aryloxy, C7-i2aralkyl, C7.i2aralkoxy, C7.-i2alkylaryl, or C7.-i2alkylaryloxy, wherein each n is independently 0, 1, 2, 3, or 4.

[0168] M may be an alkyl group such as methyl, ethyl, or propyl, an alkoxy group such as methoxy, ethoxy, or propoxy, or an aryl group such as phenyl, chlorophenyl, or tolyl; R6is a dimethylene, trimethylene or tetramethylene group; and R is a Ci-8alkyl, cyanoalkyl, or aryl such as phenyl or tolyl. R is preferably or a combination of methyl and phenyl. M may be methoxy, n is one, R6is a divalent C1-3 aliphatic group, and R is methyl.

[0169] Specific polydiorganosiloxane blocks may be of formula’s (8) - (10)

[0170] (8)

[0171] (9)

[0172]

[0173] 24POLY0133-WO-ORD 21

[0174] (10)

[0175]

[0176] or a combination comprising at least one of the foregoing, wherein E has an average value of 2 to 200, 2 to 125, 5 to 125, 5 to 100, 5 to 50, 20 to 80, or 5 to 20.

[0177] In an embodiment, blocks of formula (5) can be derived from the corresponding dihydroxy polysiloxane (11)

[0178]

[0179] wherein R, E, M, R6, and n are as described above.

[0180] The polysiloxane-polycarbonate copolymer has a polysiloxane content of 15 to 55 wt.% based on the weight of the copolymer.

[0181] Preferably the polysiloxane in the polysiloxane-polycarbonate copolymer is comprised of or consists of polydimethylsiloxane.

[0182] Polysiloxane-polycarbonate copolymers containing 10 wt.% or more are generally optically not or less transparent and are more suited towards applications contain colorants or fillers and accordingly my be opaque.

[0183] The polysiloxane-polycarbonate copolymer can have a melt volume flow rate, determined in accordance with IS01133 (300°C / 1.2 kg) of 1 to 50 cubic centimeters per 10 minutes (cm3 / 10 min), specifically 2 to 30 cm3 / 10 min. Mixtures of polysiloxane polycarbonate copolymer of different melt volume rate can be used to achieve the overall desired flow properties. Preferably the melt volume rate of the polycarbonatepolysiloxane block copolymer does not differ too much with the MVR of the24POLY0133-WO-ORD 22

[0184] polycarbonate (A), thereby enhancing the melt mixing of the components in a melt mixing device.

[0185] Flame retardant synergist (F)

[0186] The flame retardant synergist in accordance with the invention is selected from the group consisting of talc, kaolin, mica, clay, wollastonite, bentonite and mixtures of at least two of the foregoing. It is considered that in principle any layered silicate will work. Preferably the flame retardant synergist is talc, kaolin, or a mixture of talc and kaolin. In the context of the present invention the term “synergist” means a material that together with the flame retardant (C) enhances the flame retardancy.

[0187] It is to be noted that addition of flame retardant synergist will positively influence the flame retardancy

[0188] The amount of flame retardant synergist is preferably from 0.1 to 3 wt.%, preferably 0.5 to 2 wt.%, more preferably 0.8 to 1.5 wt.% based on the weight of the thermoplastic composition.

[0189] Further components (G)

[0190] 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 (G) 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 (G). In the context of the present invention the term “further components” may be replaced with the term “additives”, both terms have the same meaning.

[0191] 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 flame retardancy. For example, the further components (G) do not comprise glass fibers, flame retardants or impact modifiers.

[0192] Composition and method of manufacture24POLY0133-WO-ORD 23

[0193] The composition preferably contains an amount of free styrene-acrylonitrile copolymer of at most 3 wt.%, more preferably at most 1 wt.%, based on the weight of thermoplastic composition.

[0194] The composition of the present invention preferably has as a melt volume rate of from 5 to 20 cm3 / 10 min, preferably from 8 to 18 cm3 / 10 min, more preferably 10 to 16 or 10 to 15 cm3 / 10 min or 10 to 14 cm3 / 10 min, determined in accordance with ASTM D1238 (260°C, 2.16kg).

[0195] 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.

[0196] Preferably, the composition of the invention has, or is selected to have, a heat distortion 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.

[0197] Preferably the thermoplastic composition has, or is selected to have, a UL-94 flame retardancy rating of V01 or 1 at 1.0mm.

[0198] Preferably the thermoplastic composition has, or is selected to have, a UL-94 flame retardancy rating of 01 or 1 at 0.8mm.

[0199] Application

[0200] 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.

[0201] 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, desktop24POLY0133-WO-ORD 24

[0202] 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.

[0203] The present invention will now be further elucidated on the basis of the following nonlimiting examples.

[0204] Table 1 shows the materials being used in the experiments.

[0205] Table 1

[0206] 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)

[0207] 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).

[0208] 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).

[0209] 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).

[0210] ABS_1 ABS available in pellet from SABIC with 15-20 wt.% polybutadiene content (CAS# 9003-56-9)

[0211] ABS_4 Emulsion-ABS from SABIC with 55-65% butadiene content (CAS# 9010-94-0)

[0212] 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)

[0213]

[0214] 24POLY0133-WO-ORD 25

[0215] 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.%.

[0216] PC-POS Bisphenol A polycarbonate - polydimethylsiloxane block(EXL-PC) copolymer having a polysiloxane content of 20% and a weight average molecular weight of about 29,000 g / mol

[0217] FR-1 Phosphoric acid, (1-methylethylidene)di-4,1 -phenylene (BPADP) tetraphenyl ester (available from Wangsheng, CAS# 5945-33-5) FR-2 Solid oligomeric phosphate ester (sol-DP), available as Fyroflex (Sol-DO) Sol-DP from ICL

[0218] FR-3 Phenoxyphosphazene (hexaphenoxycyclotriphosphazene) (PPZ) commercially available as Rabitle FP-110T from Fushimi.

[0219] MR Pentaerythritol tetra stearate (CAS# 115-83-3)

[0220] (PETS)

[0221] STAB-1 Tetrakis methylene (3, 5-di-tert-butyl-4-hydroxyhydro cinnamate) (Irganox 1010) methane (available from BASF, CAS# 6683-19-8)

[0222] STAB-2 Tris(2,4-di-t-butylphenyl)phosphite (available from BASF, CAS# (Irgaphos 168) 31570-04-4)

[0223] UV 2-(2 hydroxy-5-t-octylphenyl) benzotriazole (available from ( UV- 5411 ) Cytec, CAS# 3147-75-9)

[0224] TSAN SAN encapsulated PTFE (available from SABIC, CAS# 9003-54- (TSAN) 7 and 9002-84-0) with a PTFE content of 50 wt.%

[0225] Talc Jetfine 3CA Talc, commercially available from Imerys (fine talc) Kaolin Kaolin, Inorganic substance, Hydrated Aluminum Silicate by ACTIVEMINERAL (CAS# 1332-58-7)

[0226] TSAN SAN encapsulated PTFE (available from SABIC, CAS# 9003-54- 7 and 9002-84-0) with a PTFE content of 50 wt.%

[0227]

[0228] 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 a 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: 100-150-24POLY0133-WO-ORD 26

[0229] 220-240-250-250-250-260-260-260-265°C. The extruder screw speed was set at 300 rpm while maintaining torque of 64 to 68%. A vacuum of about 100 to 800 millibar (10 to 80 kPa) was applied during the extrusion step.

[0230] Test samples were injection molded with the molding machine set from 80-240-250-260-255 °C and a mold temperature of 70 °C.

[0231] The following test methods were used

[0232] Table 2

[0233] 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.

[0234] Heat distortion temperature (HDT) ASTM D648, flatwise on samples of 3.2 mm thickness and a load of 1.8 Mpa Melt Flow Rate (MFR) Unless specifically defined otherwise the Melt Volume Rate (MVR) MFR or MVR was determined in accordance with ASTM D1238 at 260 °C at a load of 2.16 kg.

[0235] Endcap level (EC%) and hydroxyl content The endcap level can be determined based on UV 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

[0236]

[0237] 4POLY0133-WO-ORD 27

[0238] 292 nm. The results from the equipment as ppm of OH are used to calculate the endcap using also the molecular weight of the 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.

[0239] Flame retardancy UL-94 vertical burning test at the indicated thickness

[0240]

[0241] 24POLY0133-WO-ORD 28

[0242] Tables 3a - 3c below show the results of several compositions that were tested. Table 3a

[0243] CE1 CE2

[0244] PC-1 [wt.%] 36

[0245] PC-2 [wt.%] 10 32.4

[0246] PC-3 [wt.%] 36

[0247] PC-4 [wt.%] 22.4

[0248] ABS_1 [wt.%] 18 18

[0249] FR-1 [wt.%] 12.25 12.25

[0250] MR [wt.%] 0.5 0.5

[0251] STAB-1 [wt.%] 0.08 0.08

[0252] STAB-2 [wt.%] 0.08 0.08

[0253] UV [wt.%] 0.04 0.04

[0254] TSAN [wt.%] 0.65 0.65

[0255] MVR [cm3 / 10min] 17.0 16.0

[0256] Nil [J / m] 150 400

[0257] HDT [°C] 81 82

[0258] UL-94 @ 1.5mm VO VO

[0259] UL-94 @1.2mm V2 V2

[0260] UL-94 @1.0mm - - UL-94 @0.8mm - -

[0261]

[0262] 4POLY0133-WO-ORD 29

[0263] Table 3b

[0264] CE3 E3 E4 E5 E6 E7 E8 PC-1 [wt.%] 36 36 36 36 36 36 36 PC-2 [wt.%] 31.4 26.4 22.4 30.4 28.4 28.4 28.4 ABS_1 [wt.%] 18 18 22 14 13 13 13 PC-POS [wt.%] 5 5 5 5 5 5 Kaolin [wt.%] 1 1 1 1 1 0.5 Talc [wt.%] 1 0.5 FR-1 [wt.%] 12.25 12.25 12.25 12.25 12.25 12.25 12.25 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

[0265] MVR [cm3 / 10min] 13.9 14.6 13.8 15 11.2 10.7 11.2 Nil [J / m] 150 612 565 585 676 671 686 HDT [°C] N / A N / A N / A N / A N / A N / A N / A UL-94

[0266] @ 1 ,5mm VO VO VO VO VO VO VO UL-94

[0267] @1.2mm VO V1 V1 VO VO VO VO

[0268]

[0269] 4POLY0133-WO-ORD 30

[0270] Table 3c

[0271] E9 E10 E11 E12 E13 E14 PC-1 [wt.%]

[0272] PC-2 [wt.%] 10 10 10 10 10 10 PC-3 [wt.%] 36

[0273] PC-4 [wt.%] 20.4

[0274] PC-5 [wt.%] 36 36 36 36 36 PC-6 [wt.%] 20.4 18.4 18.4 18.4 18.4 ABS_1 [wt.%] 14 14 13 13 13 13 ABS_4 [wt.%] 3 3 3 3 PC-POS [wt.%] 5 5 5 5 5 5 Kaolin [wt.%] 1 1 0.5 0.5 0.5 0.5 Talc [wt.%] 0.5 0.5 0.5 0.5 FR-1 [wt.%] 12.25 12.25 12.25 7.25 7.25 7.25 FR-2 [wt.%] 5 2.5 FR-3 [wt.% 5 2.5 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 0.65 0.65 0.65 0.65 0.65 FP [wt.%]

[0275] [cm3 / 10mi

[0276] MVR n] 15.5 14.8 11.7 12.2 10.9 10.8 Nil [J / m] 487 614 681 670 713 693 HDT [°C] 83 85 84 81 85 84 UL-94 @ 1.5mm VO VO VO VO VO VO UL-94 @1.2mm VO VO VO VO VO VO UL-94 @1.0mm VO VO VO VO VO VO UL-94 @0.8mm V1 V1 V1 V1 VO VO

[0277]

Claims

24POLY0133-WO-ORD 31C LA I M S1. Thermoplastic composition comprising, based on the weight of the composition, (A) from 55 to 70 wt.% of polycarbonate(B) from 12 to 25 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 1 to 7 wt.% of polycarbonate-polysiloxane block copolymer,(F) from 0.1 to 3 wt.% of a flame retardant synergist selected from the group consisting of talc, kaolin, mica, wollastonite, bentonite and mixtures of at least two of the foregoing,(G) from 0 to 5 wt.% of further componentswherein- the sum of the components (A) - (G) is 100 wt.%,- the composition has or is selected to have a UL94 flame retardancy rating of V1 or V0 at 1.2mm,- 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 15 to 30 wt.%, based on the weight of the impact modifier.

2. The composition of claim 1 wherein the composition has or is selected to have a melt volume rate of from 5 to 20 cm3 / 10 min, preferably 10 to 16 cm3 / 10 min, as determined in accordance with ASTM D 1238 (260°C, 2.16 kg).

3. The composition of claim 1 or 2 wherein the composition has or is selected to have a notched Izod impact resistance of at least 500 J / m determined in accordance with ASTM 256.

4. The composition of any one or more of claims 1 - 3 wherein the composition has, or is selected to have, a heat distortion temperature (HDT) of at least 80°C, preferably24POLY0133-WO-ORD 32at 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 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.

6. The composition of any one or more of claims 1 - 7 wherein the impact modifier comprises at least 80 wt.%, preferably at least 90 wt.%, more preferably at least 99 wt.%, based on the weight of the impact modifier, of acrylonitrile-butadiene-styrene copolymer.

7. The composition of claim 6 wherein the acrylonitrile-butadiene-styrene copolymer consists of a mixture of- at least one first acrylonitrile-butadiene-styrene copolymer having a polybutadiene rubber content of from 40 to 70 wt.% based on the weight of said of acrylonitrile-butadiene-styrene copolymer, and- at least one second acrylonitrile-butadiene-styrene copolymer having a polybutadiene rubber content of from 15 to 25 wt.% based on the weight of said of acrylonitrile-butadiene-styrene copolymer.

8. The composition of any one or more of claims 1 - 7 wherein the polycarbonate 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.

9. The composition of any one or more of claims 1 - 8 wherein the polycarbonate comprises at least 80 wt.% of interfacial polycarbonate, based on the weight of the polycarbonate (A).24POLY0133-WO-ORD 3310. The composition of any one or more of claims 1 - 9 wherein the polycarbonatepolysiloxane copolymer comprises from 15 to 25 wt.% of polysiloxane, based on the weight of the block copolymer.

11. The composition of any one or more of claims 1- 10 wherein the further components comprise one or more of a anti-oxidant, heat stabiliser, UV absorber, mold release agent, flow promotor, colorants, fillers.

12. The composition of any one or more of claims 1 - 11 wherein the anti-drip agent comprises poly-tetrafluoroethylene and is preferably poly-tetrafluoroethylene encapsulated by styrene-acrylonitrile copolymer.

13. An article comprising or consisting of the composition of any one or more of claims 1 - 12.

14. The article of claim 13, wherein said article is comprised in or constitutes an electrical vehicle or an electrical or electronic device.

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