WO2011107273A1

WO2011107273A1 - Improved flow ignition resistant carbonate polymer composition

Info

Publication number: WO2011107273A1
Application number: PCT/EP2011/001035
Authority: WO
Inventors: Claude T. E. Van Nuffel; Pascal E. R. E J. Lakeman; Giacomo Parisi
Original assignee: Styron Europe Gmbh
Priority date: 2010-03-02
Filing date: 2011-03-02
Publication date: 2011-09-09
Also published as: TW201137033A; EP2542622A1; CN102834460A

Abstract

The present invention is an ignition resistant carbonate polymer composition, a method to make said composition and fabricated articles made therefrom. The ignition resistant carbonate polymer composition consists of: (i) an aromatic polycarbonate or an aromatic polyester carbonate, (ii) a graft (co)polymer produced by mass polymerization, (iii) a thermoplastic semi-crystalline polyalkylene dicarboxylate polymer having an intrinsic viscosity of from 0.4 to 0.7 dl/g, (iv) an aromatic phosphate compound represented by the formula (I) : wherein, R¹, R², R³ and R⁴ independently of one another each denote optionally halogenated C₁- to C₈-alkyl, or C₅- to C₆- cycloalkyl, C₆- to C₂₀- aryl or C₇- to C₁₂- aralkyl, in each case optionally substituted by alkyl and/or halogen, X denotes a mono- or polynuclear aromatic radical having 6 to 30 C atoms, n independently of one another is 0 or 1, N represents values from 0 to 30, (v) a polytetrafluoroethylene polymer, a fluorothermoplast, or mixture thereof, and (vi) one or more of a thermoplastic vinyl (co)ρolymer, an impact modifier, a filler, a reinforcing material, a stabilizer, a pigment, a dye, a mold release, a lubricant, or an anti-static agent.

Description

IMPROVED FLOW IGNITION RESISTANT CARBONATE POLYMER

COMPOSITION

FIELD OF THE INVENTION

The present invention relates to an ignition resistant carbonate polymer composition demonstrating improved flow characteristics. Said composition comprises a polycarbonate (PC); a mass polymerized graft (co)polymer, preferably a mass polymerized acrylonitrile, butadiene, and styrene terpolymer (mABS); a polyalkylene dicarboxylate polymer, preferably a low viscosity thermoplastic semi-crystalline polyester (PES); and an anti drip agent comprising a polytetrafluoroethylene polymer, a fluorothermoplast, or mixture thereof. The present invention further relates to a method to make said improved flow ignition resistant carbonate polymer composition and fabricated articles formed therefrom.

BACKGROUND OF THE INVENTION

For many years, carbonate polymer compositions have enjoyed widespread success in applications such as electronic equipment, appliance, and tool enclosures and components. In addition to providing an attractive housing for such articles, these enclosures may also play important structural roles. In recent years, one of the challenges facing the continued use of carbonate polymer compositions in such applications is 'thin walling'. One example is applications that are becoming smaller (size reduction), such as cell phones, mp3 players, notepad and notebook computes, and the like. As applications get smaller their housings, as well as their internal components, become thinner and thinner. Conversely, for applications which have increased in size, for instance 50 to 60 inch flat screen TVs, the wall thickness of the enclosure has not only become thinner (weight and material reduction), but the flow lengths much, much longer. Thin walling and longer flow lengths have necessitated carbonate polymer compositions with improved processability, moldability, and/or formability.

One of the key requirements for an electronic article in the event that its electronics fail and catch on fire is that its enclosure and/or internal parts must contain the fire so that it does not spread. If an electronic article enclosure catches fire and begins to drip and the drips are flaming drips, the fire can easily spread and endanger both life and property.

Electrical enclosure applications typically need to meet flammability requirements from one or more regulatory agency, for example Underwriter's Laboratories. For example, the procedure in Underwriter's Laboratories Standard 94 (UL 94) characterizes a material's ease of ignition, and once ignited, its burning characteristics, i.e., is the material self extinguishing, how long does it burn, does it drip and if it drips, are they flaming drips.

Carbonate polymer compositions are not inherently ignition resistant. A variety of techniques have been disclosed which help to meet industry requirements by imparting ignition resistance and lowering the ease in which a carbonate polymer composition catches on fire. Notably, non-halogen phosphorus flame retardant additives have been employed in carbonate polymer compositions to improve ignition resistance by gas phase mechanisms (as a free radical scavenger). Alternatively, or in addition to gas phase additives, attempts to further minimize the ease of flammability by solid phase mechanisms (e.g., char forming) have been disclosed, for example see US Patent Application No. 2009/0203819 which discloses the use of a non-crystalline polyester. Moreover, carbonate compositions, being thermoplastic, are predisposed to softening and dripping when heated. To minimize dripping, the viscosity of the carbonate polymer can be lowered so it does not flow easily and/or a drip suppressant such as polytetrafluoroethane (PTFE) is employed.

Ignition resistant carbonate polymer compositions are well known, for example see USP 5,061,745; 6,596,794; 6,727,301; 6,753,366; and Re 36,188. These patents describe compositions comprising a carbonate polymer, a graft (co)polymer, a phosphorus compound, and polytetrafluoroethane. However, a key challenge in providing a useful ignition resistant carbonate polymer composition is that typically the ignition resistant additive(s) and/or techniques which impart the desired ignition resistant performance cause detrimental effects with one or more of the carbonate composition's other properties, for instance mechanical properties (notably brittleness), thermal properties (thermal instability due to the heat generated by the electronics), aesthetic properties (such as pitting, streaking, gloss gradients, etc.), and especially processability (thus limiting the ability to make thin and/or large parts).

Therefore, it would be desirable to have an ignition resistant carbonate polymer composition which meets industry flammability requirements that can be used to make parts, large and small, while demonstrating a good blend of mechanical, thermal, and aesthetic properties SUMMARY OF THE INVENTION

The present invention is such an ignition resistant carbonate polymer composition. The ignition resistant carbonate polymer composition of the present invention comprises: (i) an aromatic polycarbonate or an aromatic polyester carbonate, (ii) a graft (co)polymer produced by mass polymerization, (iii) a thermoplastic semi-crystalline polyalkylene dicarboxylate polymer having an intrinsic viscosity of from 0.4 to 0.7 dl/g, (iv) an aromatic phosphorous com und represented by the formula I:

wherein, R¹, R², R³ and R⁴ independently of one another each denote optionally halogenated Ci- to Ce-alkyl, or C5- to C6- cycloalkyl, C - to C20- aryl or C₇- to C12- aralkyl, in each case optionally substituted by alkyl and/or halogen, X denotes a mono- or polynuclear aromatic radical having 6 to 30 C atoms, n independently of one another is 0 or 1, N represents values from 0 to 30, (v) a polytetrafluoroethylene polymer, fluorothermoplast, or mixture thereof, and (vi) one or more of a thermoplastic vinyl (co)polymer, an impact modifier, a filler, a reinforcing material, a stabilizer, a pigment, a dye, a mold release agent, a lubricant, or an anti-static agent.

In another embodiment, component (i) in the hereinabove composition is present in an amount from 30 to 75 parts by weight based on the total weight of the ignition resistant carbonate polymer composition.

In another embodiment, component (ii) in the hereinabove composition is present in . an amount from 5 to 60 parts by weight based on the total weight of the ignition resistant carbonate polymer composition and preferably comprises (ii.a) from 5 to 99 percent by weight of a grafting (co)polymer comprising one or more vinyl monomers on (ii.b) from 95 to 1 percent by weight, of one or more a grafting backbone having a glass transition temperature (Tg) of less than 10°C, wherein percents by weight are based on the total weight of component (ii) the graft (co)polymer. In another embodiment, component (iii) in the hereinabove composition is present in an amount from 5 to 45 parts by weight based on the total weight of the ignition resistant carbonate polymer composition.

In another embodiment, component (iv) in the hereinabove composition is present in an amount from 2 to 20 parts by weight based on the total weight of the ignition resistant carbonate polymer composition.

In another embodiment, in component (iv) in the hereinabove composition X is derived from a diol selected from diphenylphenol, bisphenol A, resorcinol or hydroquinone.

In another embodiment, component (iv) in the hereinabove composition the phosphorous compound comprises a mixture of from 3 to 95 weight percent monophosphate compound of formula I and 97 to 5 weight percent oligomeric phosphate compound of formula I.

In another embodiment, component (v) in the hereinabove composition the polytetrafluoroethylene polymer, a fluorothermoplast, or mixture thereof is present in an amount of from 0.01 to 5 parts by weight based on the total weight of the ignition resistant carbonate polymer composition.

In another embodiment, component (v) is a mixture of fibril forming

polytetrafluoroethylene polymer and fluorothermoplast present in an amount of from 0.1 to 3 parts by weight based on the total weight of the ignition resistant carbonate polymer composition.

In another embodiment, component (v) in the hereinabove composition the

fluorothermoplast comprises a polymer of interpolymerized units derived from

tetrafluoroethylene (TFE) and hexafluoropropylene (HFP), a polymer of interpolymerized units derived from TFE, HFP and vinylidenefluonde (VDF), a polymer of interpolymerized units derived from TFE, HFP and a monomer represented by formula VI, or a polymer derived from interpolymerized units derived from TFE and a monomer represented by formula VI: R⁸ ₂C=CR⁸ ₂ wherein each of R⁸ is independently selected from H, CI, or an alkyl group of from 1 to 8 carbon atoms, a cyclic alkyl group of from 1 to 10 carbon atoms, or an aryl group of from 1 to 8 carbon atoms.

In another embodiment, component (v) in the hereinabove composition the fluorothermoplast comprises a terpolymer. having interpolymerized units derived from tetrafluoroethylene (TFE), hexafluoropropylene (HFP) and vinylidenefluoride (VDF). In another embodiment, the present invention is a method to make the hereinabove composition comprising the steps of melt-compounding components (i), (ii), (iii), (iv), (v) and (vi).

In another embodiment, the present invention is a formed article comprising the hereinabove composition, preferably the formed article is an interior trim for rail vehicles, an interior and/or exterior automotive article, an enclosure for electrical devices containing small transformers, an enclosure for information dissemination and/or transmission device, an enclosure and/or cladding for medical purposes, a message device and/or enclosures therefore, a toy vehicles for children, a sheet wall element, an enclosure for safety equipment, a hatchback spoiler, a thermally insulated transport container, an apparatus for keeping and/or caring for small animals, an article for sanitary and/or bathroom installations, a cover grill for ventilation openings, an article for summer houses and sheds, and/or enclosures for garden appliances. Preferred fabricated articles include an instrument housing or enclosure such as for: a power tool, an appliance, a consumer electronic equipment such as a TV, a VCR, a DVD player, a web appliance, an electronic book, etc., - or an enclosure for. information technology equipment such as a telephone, a computer, a monitor, a fax machine, a battery charger, a scanner, a copier, a printer, a hand held computer, a flat screen display, and the like. DETAILED DESCRIPTION OF THE INVENTION

Component (i) of the present invention is a thermoplastic aromatic polycarbonate and/or aromatic polyester carbonate. Suitable aromatic polycarbonates and/or aromatic polyester carbonates according to the invention are known from the literature or can be produced by methods known from the literature (for example, for the production of aromatic polycarbonates, see Schnell, "Chemistry and Physics of Polycarbonates",

Interscience Publishers, 1964, as well as USP 3,028,365; 4,529,791; and 4,677,162; which are hereby incorporated by reference in their entirety. Suitable aromatic polyester carbonates are described in USP 3,169,121; 4,156,069; and 4,260,731; which are hereby incorporated by reference in their entirety.

The production of aromatic polycarbonates is effected, for example, by the reaction of diphenols with carbonic acid halides, preferably phosgene, and/or with aromatic dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalides, by the phase boundary method, optionally with the use of chain terminators, e.g., monophenols, and optionally with the use of trifunctional branching agents or branching agents with a functionality higher than three, for example triphenols or tetraphenols.

Diphenols for the production of the aromatic polycarbonates and/or aromatic polyester carbonates are referably those of formula Π

wherein A denotes a single bond, a Q - C5 alkylene, a C₂ - C5 alkylidene, a C5 - C cycloalkylidene, -0-, -SO-, -CO-, -S-, -SO2-, or a Ce - Q₂ arylene, on to which other aromatic rings, which optionally contain hetero atoms, can be condensed, or a radical of formula ΙΠ or IV

B in each case is independently hydrogen, a Q - C12 alkyl, preferably methyl, or a halogen, preferably chlorine and/or bromine;

x in each case is mutually independently 0, 1, or 2;

p is 0 or 1 ;

R^c and R^d are mutually independent of each other and are individually selectable for each X¹ and are hydrogen or a Ci - Ce alkyl, preferably hydrogen, methyl or ethyl; X¹ denotes carbon; and

m denotes an integer from 4 to 7, preferably 4 or 5, with the proviso that R° and R^d simultaneously denotes an alkyl on at least one Xi atom. The preferred diphenols are hydroquinone, resorcinol, dihydroxybiphenyls, bis(hydroxyphenyl)-Ci - C5 alkanes, bis(hydroxyphenyl)-C5 -Q cycloalkanes,

bis(hydroxyphenyl)ethers, bis(hydroxyphenyl)sulfoxides, bis(hydroxyphenyl)ketones, bis(hydroxyphenyl)sulfones and alpha, alpha'-bis(hydroxyphenyl)diisopropylbenzenes, as well as derivatives thereof which have brominated and/or chlorinated nuclei.

Diphenols which are particularly preferred are 4,4'-dihydroxybiphenyl, bisphenol A, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1 , 1 -bis(4-hydroxyphenyl)-cyclohexane, 1,1- bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4-dihydroxydiphenyl sulfide and 4,4- dihydroxydiphenyl sulfone, as well as di- and tetrabrominated or chlorinated derivatives thereof, such as 2,2-bis(3-chloro-4-hydroxyphenyl)propane, 2,2-bis-(3,5-dichloro-4- hydroxyphenyl)propane or 2,2-bis(3,5-dibrorao-4-hydroxyphenyl)propane. 2, 2-bis-(4- hydroxyphenyl)propane (bisphenol A) is particularly preferred. The diphenols can be used individually or as arbitrary mixtures. The diphenols are known from the literature or can be obtained by methods known from the literature.

Examples of suitable chain terminators for the production of the aromatic polycarbonates include phenol, p-chlorophenol, p-tert-butylphenol or 2,4,6-tribromophenol, as well as long chain alkylphenols such as 4-(l,3-dimethyl-butyl)-phenol or

monoalkylphenols or dialkylphenols which contain a total of 8 to 20 C atoms in their alkyl substituents, such as 3,5-di-tert-butyl-phenol, p-iso-octylphenol, p-tert-octylphenol, p- dodecylphenol, 2-(3,5-dimethylheptyl)-phenol and 4-(3,5-dimethylheptyl)-phenol. The amount of chain terminators used is generally between 0.1 mole percent and 10 mole percent with respect to the molar sum of the diphenols used in each case.

The aromatic polycarbonates and/or aromatic polyester carbonates of the present invention preferably have a mean weight average molecular weights of from about 10,000 to about 200,000 preferably about 20,000 to about 80,000. Unless otherwise indicated, the references to aromatic polycarbonate and/or aromatic polyester carbonate "molecular weight" herein refer to weight average molecular weights (M_w) determined by gel permeation chromatography (GPC) using laser scattering techniques with a bisphenol A polycarbonate standard and is given in units of grams per mole (g/mole).

The aromatic polycarbonates can be branched in the known manner, for example by the incorporation of 0.05 to 2.0 mole percent, with respect to the sum of the diphenols used, of trifunctional compounds or of compounds with a functionality higher than three, for example those which contain three or more phenolic groups. Branched polycarbonates suitable for the present invention can be prepared by known techniques, for example several suitable methods are disclosed in USP 3,028,365; 4,529,791 ; and 4,677, 162; which are hereby incorporated by reference in their entirety.

Suitable branching agents that may be used are tri- or multi-functional carboxylic acid chlorides, such as trimesic acid trichloride, cyanuric acid trichloride, 3,3'- ,4,4'- benzophenonetetracarboxylic acid tetrachloride, 1 ,4,5,8-naphthalene-tetracarboxylic acid tetrachloride or pyromellitic acid tetrachloride for example, in amounts of 0.01 to 1.0 mole percent (with respect to the dicarboxylic acid dichlorides used) or tri- or multi-functional phenols such as phloroglucinol, 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)-2-heptene, 4,4- dimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, l,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1- tris(4-hydroxyphenyl)ethane, tris(4-hydroxyphenyl)-phenyl-methane, 2,2-bis[4,4-bis(4- hydroxyphenyl)cyclohexyl]-propane, 2,4-bis[ 1 -(4-hydroxyphenyl)- 1 -methylethyl]phenol, tetrakis(4-hydroxyphenyl)-methane, 2,6-bis(2-hydroxy-5-methyl-benzyl)-4-methyl-phenol, 2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)propane, or tetrakis(4-[ 1 -(4-hydroxyphenyl)- l-methylethyl]-phenoxy)-methane in amounts of 0.01 to 1.0 mole percent with respect to the diphenols used. Phenolic branching agents can be placed in the reaction vessel with the diphenols. Acid chloride branching agents can be introduced together with the acid chlorides.

Both homopolycarbonates and copolycarbonates are suitable. For the production of copolycarbonates according to component (i) in accordance with the invention, 1 to 25 parts by weight, preferably 2.5 to 25 parts by weight (with respect to the total amount of diphenols to be used) of polydiorganosiloxanes comprising hydroxy-aryloxy terminal groups can also be used. These are known (see, for example, USP 3,419,634) or can be produced by methods known from the literature.

Apart from bisphenol A homopolycarbonates, the preferred polycarbonates are the copolycarbonates of bisphenol A with up to 15 mole percent, with respect to the molar sums of the diphenols, of other diphenols which are cited as preferred or particularly preferred, in particular 2,2-bis(3,5-dibromo-4-hydroxyphenyl)-propane.

The preferred aromatic dicarboxylic acid dihalides for the production of the aromatic polyester carbonates are the diacid dichlorides of isophthalic acid, terephthalic acid, diphenyl ether-4,4'-dicarboxylic acid and naphthalene-2,6-dicarboxylic acid. Mixtures of the diacid dichlorides of isophthalic acid and terephthalic in a ratio between 1 :20 and 20: 1 are particularly preferred. A carbonic acid halide, preferably phosgene, is used in conjunction as a difunctional acid derivative during the production of the polyester carbonates.

Apart from the aforementioned monophenols, suitable chain terminators for the production of the aromatic polyester carbonates include chlorocarboxylic acid esters thereof, as well as the acid chlorides of aromatic monocarboxylic acids which may optionally be substituted by Ci - C22 alkyl groups, or by halogen atoms, and also include aliphatic C₂ - C₂₂ monocarboxylic acid chlorides. The amount of chain terminator is 0.1 to 10 mole percent in each case, with respect to the moles of diphenols in the case of phenolic chain terminators and with respect to the moles of dicarboxylic acid dichlorides in the case of monocarboxylic acid chloride chain terminators.

The aromatic polyester carbonates may also contain incorporated hydroxycarboxylic acids. The aromatic polyester carbonates may be either linear or may be branched. Suitable branching agents are disclosed hereinabove.

The proportion of carbonate structural units in the aromatic polyester carbonates can be arbitrarily varied. The content of carbonate groups is preferably up to 100 mole percent, particularly up to 80 mole percent, most preferably up to 50 mole percent, with respect to the sum of ester groups and carbonate groups. Both the ester and the carbonate fraction of the aromatic polyester carbonates can be present in the form of blocks, or can be randomly distributed in the condensation polymer.

The relative solution viscosity (ηκΐ) of the aromatic polycarbonates and aromatic polyester carbonates is within the range of 1.18 to 1.4, preferably 1.22 to 1.3 (as measured on solutions of 0.5 g of polycarbonate and polyester carbonate, respectively, in 100 mL of methylene chloride at 25°C).

The aromatic polycarbonates and aromatic polyester carbonates can be used individually or in any mixture with each other.

The thermoplastic aromatic polycarbonates and/or aromatic polyester carbonates (i) are present in an amount equal to or greater than about 30 parts by weight, preferably equal to or greater than about 35 parts by weight, preferably equal to or greater than about 40 parts by weight, and more preferably equal to or greater than about 45 parts by weight based on the total weight of the ignition resistant carbonate polymer composition. The

thermoplastic aromatic polycarbonates and/or aromatic polyester carbonates (i) are present in an amount equal to or less than about 75 parts by weight, preferably equal to or greater than about 70 parts by weight, more preferably equal to or greater than about 65 parts by weight, more preferably equal to or greater than about 60 parts by weight, and more preferably equal to or less than about 55 parts by weight based on the weight of the ignition resistant carbonate polymer composition. Unless stated otherwise, parts by weight are based on the total weight of the ignition resistant carbonate polymer composition.

Component (ii) of the present invention is a graft (co)polymer, preferably one or more grafting (co)polymer (ii.a) comprising one or more vinyl monomer grafted on one or more grafting backbone (ii.b), said grafting backbone having a glass transition temperature less than 10°C, preferably less than 0°C, preferably less than about -10°C, and more preferably less than -20°C. The grafting backbone (ii.b) generally has an average particle size (Dy, value) of from 0.01 to 7 microns. The grafting (co)polymer (ii.a) is present in an amount of from 5 to 99, preferably 30 to 80 percent by weight and the grafting backbone (ii.b) is present in an amount of from 95 to 1, preferably from 70 to 20 percent by weight, weight percents are based on the total weight of the graft (co)polymer (ii).

Preferably, the grafting copolymer (ii.a) comprises monomers which are preferably mixtures (ii.a.1) of 50 to 99 parts by weight of aromatic vinyl compounds and/or aromatic vinyl compounds with substituted nuclei (such as styrene, alpha-methylstyrene, p- methylstyrene or p-chlorostyrene) and or butylacrylate, ethylacrylate, or ethylhexylacrylate and/or Q - C alkyl esters of (meth)acrylic acid (such as methyl methacrylate or ethyl methacrylate), and (ii.a.2) 1 to 50 parts by weight of vinyl cyanides (unsaturated nitriles, such as acrylonitrile and methacrylonitrile) and/or C_\ - C₄ alkyl esters of (meth)acrylic acid (such as methyl methacrylate, n-butyl acrylate and t-butyl acrylate) and/or derivatives (such as anhydrides and imides) of unsaturated carboxylic acids (for example maleic anhydride and N-phenylmaleimide).

The preferred monomers (ii.a.l) are selected from at least one of the monomers styrene, alpha-methylstyrene and methyl methacrylate. The preferred monomers (ii.a.2) are selected from at least one of the monomers acrylonitrile, maleic anhydride and methyl methacrylate. The monomers which are particularly preferred are styrene as (ii.a.l) and acrylonitrile as (ii.a.2).

Examples of suitable grafting backbones (ii.b) for graft (co)polymers (ii) include diene rubbers, ethylene/propylene and optionally diene (EP(D)M) rubbers, acrylate, polyurethane, silicone, silicone/acrylate, chloroprene and ethylene/vinyl acetate rubbers.

The preferred grafting backbones (ii.b) are diene rubbers (for example based on butadiene, isoprene, etc.) or mixtures of diene rubbers or copolymers of diene rubbers or mixtures thereof with other copolymerizable monomers (for example according to (ii.a.l) and (ii.a.2)), providing that the glass transition temperature is less than about 10°C, preferably less than about 0°C, preferably less than about -10°C, and more preferably less than about -20°C. Pure polybutadiene rubber is particularly preferred. A particularly preferred graft (co)polymer (ii) is acrylonitrile, butadiene, and styrene terpolymer (ABS).

Graft (co)polymers (ii) are produced by radical polymerization, for example by emulsion, mass, suspension, solution or bulk polymerization. For examples of the mass, bulk, mass-solution (sometimes referred to as solution), or mass-suspension (sometimes referred to as suspension) polymerization, which are generally known as mass

polymerization processes, see USP 3,660,535; 3,243,481; and 4,239,863; which are incorporated herein by reference. Suitable ABS polymers may be produced by redox initiation with an initiator system comprising an organic hydroperoxide and ascorbic acid according to USP 4,937,285; which is incorporated herein by reference.

To achieve the desired balance of end properties (in particularly impact strength and ignition resistance) for the ignition resistant carbonate polymer composition of the present invention we found that using a mass polymerized non-silicon-containing graft (co)polymer is most preferred. A mixture of mass and emulsion polymerized non-silicon-containing graft (co)polymer is less preferred, but may still result in an acceptable overall balance of properties. However, we have found that for the ignition resistant carbonate polymer compositions of the present invention, the use of emulsion polymerized non-silicon- containing graft (co)polymer will not achieve an acceptable balance of properties, especially in regards to hydrolytic stability.

Suitable acrylate rubbers according to (ii.b) of graft (co)polymer (ii) are preferably polymers of acrylic acid alkyl esters, optionally with up to 40 percent by weight, with respect to (ii.b), of other polymerizable, ethylenically unsaturated monomers. The preferred polymerizable acrylic acid esters include C_\ - C₈ alkyl esters, for example methyl, ethyl, butyl, n-octyl and 2-ethylhexyl esters: halogenoalkyl esters, preferably halogeno-Ci - Ce - alkyl esters such as chloroethyl acrylate, as well as mixtures of these monomers.

Monomers with more than one polymerizable double bond can be copolymerized to provide cross-linking. The preferred examples of cross-linking monomers are the esters of unsaturated monocarboxylic acids containing 3 to 8 C atoms and unsaturated monohydric alcohols containing 3 to 12 C atoms, or saturated polyols containing 2 to 4 OH groups and 2 to 20 C atoms, such as ethylene glycol dimethacrylate or allyl methacrylate for example; multiply-unsaturated heterocyclic compounds, such as trivinyl and triallyl cyanurate for example; polyfunctional vinyl compounds such as di- and trivinylbenzenes; and also triallyl phosphate and diallyl phthalate.

The preferred cross-linking monomers are allyl methacrylate, ethylene glycol dimethacrylate, diallyl phthalate and heterocyclic compounds which contain at least 3 ethylenically unsaturated groups. Cross-linking monomers which are particularly preferred are the cyclic monomers triallyl cyanurate, triallyl isocyanurate, triacryloyl hexahydro-s- triazine and triallylbenzenes. The amount of cross-linked monomer is preferably 0.02 to 5, particularly 0.05 to 2 percent by weight, with respect to grafting backbone (ii.b). For cyclic cross-linking monomers containing at least 3 ethylenically unsaturated groups, it is advantageous to restrict the amount thereof to less than 1 percent by weight of graft base (ii.b).

Examples of preferred "other" polymerizable, ethylenically unsaturated monomers which can optionally be employed apart from acrylic acid esters for the production of graft base (ii.b) include acrylonitrile, styrene, alpha-methylstyrene, acrylamides, vinyl-Ci - C¼- alkyl ethers, methyl methacrylate and butadiene. The acrylate rubbers which are preferred as the grafting backbone (ii.b) are emulsion polymers which have a gel content of at least 20 percent, preferably 40 percent, more preferably 60 percent by weight.

Other grafting backbones which are suitable according to (ii.b) are silicone rubbers with graft-active sites.

Since, as is known, the graft monomers comprising the grafting (co)polymer (ii.a) are not grafted completely on to the grafting backbone (ii.b) during the grafting reaction, graft (co)polymers (ii) are also to be understood according to the invention to include those products which are obtained by (co)polymerization of the graft monomers in the presence of the graft base and which occur in conjunction during processing (i.e., (co)polymer from the polymerization of graft monomer(s) of (ii.a)).

Unless otherwise indicated, the average graft base particle size is a volume-weighted mean particle diameter (D_v) determined by analyzing Transmission Electron Microscopy (TEM) images, for a good discussion of particle size determination see USP 6,380,304 which is incorporated herein by reference. Typically, a correction for section thickness is done when particles are larger than 1 micron.

The average particle diameter of the grafting backbone (ii.b) produced by a mass process is equal to or greater than about 0.01 microns, preferably equal to or greater than about 0.1 microns, more preferably equal to or greater than about 0.2 microns, and even more preferably equal to or greater than about 0.3 microns. The average particle diameter of the grafting backbone (ii.b) produced by a mass process is equal to or less than about 7 microns, preferably equal to or less than about 6 microns, more preferably equal to or less than about 5 microns, and even more preferably equal to or less than about 4 microns.

The rubber-modified polymers of the present invention can have a broad

monomodal particle size distribution or a multi-modal particle size distribution, for example, bimodal particle size distribution. In either case, the rubber components can comprise one rubber or a blend of rubbers. In particular, more than one rubber can be used in a

monomodal or bimodal process. A bimodal rubber particle size distribution is defined as having two distinct peaks of particles when graphed on axes of particle size versus volume fraction, whereby one peak designates smaller particles and the other peak designates larger particles.

Typically, in a mass produced grafting backbone bimodal particle size distribution, the larger particle fraction will have a volume average particle size of from about 0.5 microns, and most preferably from about 0.7 microns to about 3 microns, preferably to about 2.5 microns, and most preferably to about 2 microns. Typically, the smaller particle fraction will have a volume average particle size of from about 0.01 microns, preferably from about 0.1 microns to 0.4 microns, preferably to about 0.35 microns, and more preferably to about 0.3 microns.

The gel content of grafting backbone (ii.b) produced by a mass process can be determined at 25°C in toluene and is at least 10 weight percent, preferably at least 15 weight percent, even more preferably at lest 20 weight percent, and most preferably at least 25 weight percent based on the total weight of the grafting backbone (ii.b).

The average particle diameter of the grafting backbone (ii.b) produced by an emulsion process is equal to or greater than about 0.01 microns, preferably equal to or greater than about 0.03 microns, and even more preferably equal to or greater than about 0.05 microns. The average particle diameter of the grafting backbone (ii.b) produced by an emulsion process is equal to or less than about 2 microns, preferably equal to or less than about 1.5 microns, and even more preferably equal to or less than about 1 micron.

Typically, in an emulsion produced grafting backbone bimodal particle size distribution, the larger particle fraction will have a volume average particle size of from about 0.3 microns, more preferably from about 0.4 microns, and most preferably from about 0.5 microns to about 3 microns, preferably to about 2 microns, more preferably to about 1.5 microns, and most preferably to about 1 micron. Typically, the smaller particle fraction will have a volume average particle size of from about 0.01 microns, preferably from about 0.03 microns to 0.3 microns, preferably from about 0.05 microns to about 0.2 microns.

The gel content of an emulsion produced grafting backbone (ii.b) is at least 20 percent by weight, preferably at least 30 percent, more preferably at least 40 percent, even more preferably at least 50 percent, and most preferably at least 60 percent by weight as measured in toluene.

For a mixture of mass produced graft (co)polymer (ii) and emulsion produced graft (co)polymer (ii) the average particle diameter of the grafting backbone (ii.b) is equal to or greater than about 0.01 microns, preferably equal to or greater than about 0.1 microns, more preferably equal to or greater than about 0.15 microns, more preferably equal to or greater than about 0.2 microns, and even more preferably equal to or greater than about 0.25 microns. For a mixture of mass produced graft (co)polymer (ii) and emulsion produced graft (co)polymer (ii) the average particle diameter of the grafting backbone (ii.b) is equal to or less than about 7 microns, preferably equal to or less than about 5 microns, more preferably equal to or less than about 4 microns, more preferably equal to or less than about 3 micron, and most preferably equal to or less than 2 microns.

For a mixture of mass produced graft (co)polymer (ii) and emulsion produced graft (copolymer (ii) the resulting bimodal rubber particle size distribution may be described by the independent preferred rubber particle size ranges given hereinabove for mass produced graft polymer and emulsion produced graft polymer.

The graft (co)polymer (ii) is present in an amount equal to or greater than about 5 parts by weight, preferably equal to or greater than about 7 parts by weight, more preferably equal to or greater than about 10 parts by weight, and more preferably equal to or greater than about 12 parts by weight based on the total weight of the ignition resistant carbonate polymer composition. The graft (co)polymer (ii) is present in an amount equal to or less than about 60 parts by weight, preferably equal to or less than about 50 parts by weight, more preferably equal to or less than about 40 parts by weight, more preferably equal to or less than about 30 parts by weight, and more preferably equal to or less than about 25 parts by weight based on the total weight of the ignition resistant carbonate polymer composition.

Component (iii) of the present invention comprises a thermoplastic polyalkylene dicarboxylate polymer, commonly referred to as a polyester. Preferable thermoplastic polyalkylene dicarboxylate polymers are semi-crystalline, preferably made by melt polymerization having, and more preferably having a low molecular weight. Suitable thermoplastic polyalkylene dicarboxylate polymers are reaction products of aromatic dicarboxylic acids or the reactive derivatives thereof, such as dimethyl esters or anhydrides, and aliphatic, cycloaliphatic or araliphatic diols, dialkyl esters, diacid chlorides, carboxylic acid salts, and diaryl esters, together with mixtures of these reaction products. The dicarboxylic acid may be an aliphatic acid such as succinic, glutaric, adipic, sebacic, azelaic, suberic acid, or cyclohexane dicarboxylic acid, or an aromatic acid such as isophtalic acid, terephthalic acid, naphthyl dicarboxylic acid, or biphenyl dicarboxylic acid. The aromatic acids, especially terephthalic acid, are preferred. The use of an ester and especially a lower alkyl ester is preferred, more preferably a methyl, ethyl or butyl ester.

Preferred polyalkylene dicarboxylate polymers are produced using a mole ratio of diol component to dicarboxylic acid or ester component from about 1 : 1 to about 1.4: 1 and preferably from about 1.2:1 to about 1.3:1.

In addition to terephthalic acid residues, the preferred polyalkylene dicarboxylate may contain up to 20 mole percent, preferably up to 10 mole percent, of residues of other aromatic or cycloaliphatic dicarboxylic acids having 8 to 14 C atoms or aliphatic

dicarboxylic acids having 4 to 12 C atoms, such as for example residues of phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, cyclohexanediacetic acid.

In addition to ethylene glycol or 1,4-butanediol residues, the preferred polyalkylene dicarboxylate polymers may contain up to 20 mole percent, preferably up to 10 mole percent, of other aliphatic diols having 3 to 12 C atoms or cycloaliphatic diols having 6 to 21 C atoms, for example residues of 1,3-propanediol, 2-ethyl-l,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 3-ethyl-2,4-pentane- diol, 2-methyl-2,4-pentanediol, 2,2,4-trimethyl-l,3-pentanediol, 2-ethyl-l,3-hexane-diol, 2,2-diethyl- 1,3-propanediol, 2,5-hexanediol, l,4-di-(.beta.-hydroxy-ethoxy)benzene, 2,2- bis-(4-hydroxycyclohexyl)propane, 2,4-dihydroxy- 1 , 1 ,3,3-tetramethylcyclobutane, 2,2-bis- (4-.beta.-phydroxyethoxyphenyl)propane and 2,2-bis-(4-hydroxypropoxyphenyl)propane.

The polyalkylene dicarboxylate polymers may be branched by incorporating relatively small quantifies of tri-. or tetrahydric alcohols or tri- or tetrabasic carboxylic acids, for example according to USP 3,692,744. Examples of further preferred branching agents are trimesic acid, trimellitic acid, trimethylolethane and trimethylolpropane and

pentaerythritol.

Particularly preferred polyalkylene dicarboxylate polymers are those solely produced from terephthalic acid and the reactive derivatives thereof (for example the dialkyl esters thereof) and ethylene glycol (such as polyethylene terephthalate (PET)) and/or 1, 4- butanediol (such as polybutylene terephthalate (PBT)), and mixtures of these polyalkylene terephthalate polymers.

Preferred mixtures of polyalkylene dicarboxylate polymers contain 1 to 50 weight percent, preferably 1 to 30 weight percent, of polyethylene terephthalate polymer and 50 to 99 weight percent, preferably 70 to 99 weight percent, of polybutylene terephthalate polymer.

Methods of producing polyalkylene dicarboxylate polymers are well known.

Polyalkylene dicarboxylate polymers may be made by melt polymerization and/or solid- state polymerization. The polyalkylene dicarboxylate polymer of the present invention desirably is made by melt polymerization and has a low molecular weight, for example see USP 5,714,262 which is incorporated by reference herein in its entirety. The molecular weight of a polyalkylene dicarboxylate polymer is reflected in its intrinsic viscosity (IV) which is expresses in deciliters per gram (dl/g); the higher the molecular weight (longer the polymer chains), the stiffer the material and, consequently, the higher the intrinsic viscosity. The intrinsic viscosity for the polyalkylene dicarboxylate polymers used in the carbonate polymer compositions of the present invention preferably have an intrinsic viscosity of from 0.4 to 0.7 dl/g, more preferably of from 0.5 to 0.6 dl/g measured in phenol/o- dichlorobenzene (1:1 parts by weight) at 25 °C in an Ubbelohde viscosimeter.

The polyalkylene dicarboxylate polymers may be produced using known methods. The reaction between the alkanediol and the dicarboxylic acid is typically promoted by a metallic catalyst; useful catalysts in the preparation of polyesters are described, for example in USP 4,401,804, incorporated herein by reference. Further suitable reagents for forming polyesters are described, for example, in the following USP 2,465,319; 2,720,502;

2,727,881; 2,822,348; 3,047,539; all of which are incorporated herein by reference and in published art, see Pang et. Al. , REVIEW of CONVENTIONAL and NOVEL

POLYMERIZATION PROCESSES for POLYESTERS, PROGRESS in POLYMER

SCIENCE, ELSEVIER, 31 (2006) 1009-1037. A preparation example of described polyalkylene dicarboxylate polymers could entail heating the dicarboxylic acid or ester thereof, alkenediol and metallic catalyst to typically 180°C-300°C for a period of time suitable for producing the desired polymer. The amount of metallic catalyst used is typically about 0.005-0.2 percent by weight, based on the amount of acid or ester.

The thermoplastic semi-crystalline polyalkylene dicarboxylate polymer (iii) is present in an amount equal to or greater than about 5 parts by weight, preferably equal to or greater than about 10 parts by weight, more preferably equal to or greater than about 15 parts by weight, and more preferably equal to or greater than about 20 parts by weight based on the weight of the ignition resistant carbonate polymer composition. The thermoplastic polyalkylene dicarboxylate polymer (iii) is present in an amount equal to or less than about 45 parts by weight, preferably equal to or less than about 40 parts by weight, more preferably equal to or less than about 35 parts by weight, more preferably equal to or less than about 30 parts by weight, and more preferably equal to or less than about 25 parts by weight based on the weight of the ignition resistant carbonate polymer composition.

Component (iv) of the present invention is an aromatic phosphorous compound that has the formula I:

wherein in the formula I,

R¹, R², R³ and R⁴ independently of one another each denote optionally halogenated Ci- to Cg-alkyl, or C5- to Q- cycloalkyl, Ce- to C₂o- aryl or C7- to C12- aralkyl, in each case optionally substituted by alkyl, preferably Ci-C₄-alkyl, and/or halogen, preferably bromine or chlorine. Preferably, R¹, R², R³ and R⁴ independently of one another represent C1-C4 -alkyl, phenyl, naphthyl or phenyl-C|-C₄-alkyl. The aromatic groups R¹, R², R³ and R⁴ can in turn be substituted by halogen and/or alkyl groups, preferably chlorine, bromine and/or Ci-Q-alkyl. Particularly preferred aryl radicals are cresyl, phenyl, xylenyl, propylphenyl or butylphenyl and the corresponding brominated and chlorinated derivatives thereof.

X in the formula I denotes a mono- or polynuclear aromatic radical having 6 to 30 C atoms. This is derived from diphenols of the formula Π. Preferred diphenols are diphenylphenol, bisphenol A, resorcinol or hydroquinone or chlorinated or brominated derivatives thereof,

n in the formula I independently of one another can be 0 or 1 , and n is preferably 1. N represents values from 0 to 30, preferably an average value of 0.3 to 20, particularly preferably 0.5 to 10, in particular 0.5 to 6.

Compounds of the formula la

wherein

R¹, R², R³ and R⁴, n and N have the meaning given above in the case of formula I, R⁵ and R⁶ independently of one another denote Ci-C4-alkyl, preferably methyl, or

halogen, preferably chlorine and/or bromine,

Y denotes Ci-C₇-alkylidene, Ci-C7-alkylene, Cs-Cn-cycloalkylene, C5-C12- cycloalkylidene, --0—,— S— ,—SO— or—CO— and q denotes 0 or the number 1 or 2, and Y preferably represents Ci-C₇-alkylidene, in particular isopropylidene, or methylene

are furthermore also a preferred phosphorus compound.

In the formula la, the group lb

corresponds to the radical X in formula I.

Monophosphates (N=0), oligophosphates (N=l-30) or mixtures of mono- and oligophosphates (N>0) can be employed as component (iv) according to the invention.

In one embodiment, component (iv) is preferably present in the molding

compositions according to the invention as a mixture of 1 to 99 weight percent, preferably 3 to 95 weight percent, more preferably 5 to 90 weight percent, more preferably 10 to 90 weight percent, more preferably 12 to 40 weight percent of at least one monophosphorus compound of the formula I and 1 to 99 weight percent, preferably 5 to 97 weight percent, more preferably 10 to 95 weight percent, more 10 to 90 weight percent, more preferably 60 to 88 weight percent of at least one oligophosphorus compound of the formula I, in each case weight percent based on the total weight of phosphorus compounds, and the mixture having an average N of 0.3 to 20, preferably 0.5 to 10, particularly preferably 0.5 to 6.

Monophosphorus compounds of the formula I are, in particular, tributyl phosphate, tris-(2-chloroethyl) phosphate, tris-(2,3-dibromopropyl) phosphate, triphenyl phosphate, tricresyl phosphate, diphenyl cresyl phosphate, diphenyl octyl phosphate, diphenyl 2- ethylcresyl phosphate, tri-(isopropylphenyl) phosphate, halogen-substituted aryl phosphates, methylphosphonic acid dimethyl ester, methylphosphonic acid diphenyl ester,

phenylphosphonic acid diethyl ester, triphenylphosphine oxide or tricresylphosphine oxide.

The phosphorus compounds according to component (iv) are known, for example see EP-A 363 608 and EP-A 640 655.

The phosphorus compounds (iv) are present in an amount equal to or greater than 2 parts by weight, preferably equal to or greater than 4 part by weight, more preferably equal to or greater than 6 parts by weight, and most preferably equal to or greater than 8 parts by weight based on the total weight of the ignition resistant carbonate polymer composition of the invention. The phosphorus compounds (iv) are present in an amount equal to or less than 30 parts by weight, preferably equal to or less than 25 parts by weight, more preferably equal to or less than 20 parts by weight, and most preferably equal to or less than 15 parts by weight based on the total weight of the ignition resistant carbonate polymer composition of the invention.

The anti-drip component (v) of the present invention comprises a

polytetrafluoroethylene, preferably fibrillating polytetrafluoroethylene, a fluorothermoplast, and/or mixtures thereof. The fibrillating polytetrafluoroethylene (PTFE) is typically a homopolymer of tetrafluoroethylene (TFE) but may also be a copolymer of TFE with for example another fluorinated monomer such as chlorotrifluoroethylene (CTFE), a perfluorinated vinyl ether such as perfluoromethyl vinyl ether (PMVE) or a perfluorinated olefin such as hexafluoropropylene (HFP). The amount of the fluorinated comonomer should however be low enough so as to obtain a high molecular weight polymer that is not processible from the melt. This means in general that the melt viscosity of the polymer should be more than 10 Pascal seconds (Pa.s.). Typically the amount of the optional comonomers should not be more than 1 percent so that the PTFE conforms to the ISO 12086 standard defining non-melt processible PTFE. Such copolymers of TFE are known in the art as modified PTFE.

The fibrillating PTFE typically has an average particle size (number average) of not more than 10 micron. Generally the average particle size of the fibrillating PTFE will be between 50 nanometer and 5 micron, for example between 100 nanometer and 1 micron. A practical range may be from 50 to 500 nanometers. Conveniently, fibrillating PTFE can be produced via aqueous emulsion polymerization.

The fluorothermoplast used is typically a semi-crystalline fluoropolymer. Typically the fluorothermoplast should have a melting point such that the fluorothermoplast is in its molten state under the melt processing conditions used for processing the carbonate polymer composition. Fluorothermoplasts having a melting point of 100°C to 310°C are generally desired for use in this invention. Preferably, the fluorothermoplast has a melting point of between 100°C and 250°C. Frequently, the fluorothermoplast will have a melting point of not more than 225°C.

The fluorothermoplast should be used in amount effective to avoid agglomeration of the particles of fibrillating PTFE. The effective amount can be easily determined by one skilled in the art with routine experimentation. Typically, an effective amount of fluorothermoplast is an amount of at least 10 percent by weight based on the weight of fibrillating PTFE. It will generally be desired to maximize the amount of PTFE as a higher amount of PTFE will make the latter more effective in achieving desired effects when added to the carbonate polymer composition melt such as for example increasing the melt strength of the carbonate polymer composition. A practical range of the amount of

fluorothermoplast is at least 10 percent by weight, for example between 10 and 60 percent by weight, conveniently between 12 and 50 percent by weight, commonly between 15 and 30 percent by weight based on the total weight of fibrillating PTFE.

Suitable fluorothermoplasts, for use include fluoropolymers that comprise interpolymerized units derived from at least one fluorinated, ethylenically unsaturated monomer, preferably two or more monomers, of the formula V:

R⁷CF=CR₂ V

wherein each R⁷ is independently selected from H, F, CI, alkyl of from 1 to 8 carbon atoms, aryl of from 1 to 8 carbon atoms, cyclic alkyl of from 1 to 10 carbon atoms, or perfluoroalkyl of from 1 to 8 carbon atoms. The R group preferably contains from 1 to 3 carbon atoms. In this monomer each R group may be the same as each of the other R groups. Alternatively, each R group may be different from one or more of the other R groups.

The fluoropolymer may also comprise a copolymer derived from the

interpolymerization of at least one formula V monomer with at least one nonfluorinated, copolymerizable comonomer having the formula VI:

R⁸ ₂C=CR⁸2 VI

wherein each of R⁸ is independently selected from H, CI, or an alkyl group of from 1 to 8 carbon atoms, a cyclic alkyl group of from 1 to 10 carbon atoms, or an aryl group of from 1 to 8 carbon atoms. R⁸ preferably contains from 1 to 3 carbon atoms.

Representative examples of useful fluorinated formula V monomers include, but are not limited to vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene,

chlorotrifluoroethylene, 2-chloropentafluoropropene, dichlorodifluoroethylene, 1,1- dichlorofluoroethylene, and mixtures thereof. Perfluoro-1, 3-dioxoles may also be used.

The perfluoro-1, 3-dioxole monomers and their copolymers are described in USP 4,558,141, which is incorporated herein by reference.

Representative examples of useful formula VI monomers include ethylene, propylene, etc.

Particular examples of fluoropolymers include polyvinylidene fluoride,

fluoropolymers derived from the interpolymerization of two or more different formula V monomers and fluoropolymers derived from one or more formula V monomers with one or more formula VI monomers. Examples of such polymers are those having interpolymerized units derived from vinylidene fluoride (VDF) and hexafluoropropylene (HFP); and those derived from tetrafluoroethylene (TFE) and at least 5 weight percent of at least one copolymerizable comonomer other than TFE. This latter class of fluoropolymers includes polymers of interpolymerized units derived from TFE and HFP; polymers of

interpolymerized units derived from TFE, HFP and VDF; polymers of interpolymerized units derived from TFE, HFP and a formula VI monomer; and polymers derived from interpolymerized units derived from TFE and a formula VI monomer.

The fluorothermoplast may be produced by any of the known polymerization techniques although aqueous emulsion polymerization will generally be preferred for obtaining the melt-processible thermoplastic fluoropolymer. Component (v) is preferably prepared by blending an aqueous dispersion of the fibrillating PTFE with an aqueous dispersion of the fluorothermoplast and coagulating the mixed dispersion followed by drying the product. Such a method is disclosed in for example WO 01/27197. Such method offers the advantage that fibrillation of the PTFE is avoided while preparing component (v). It is however also possible to prepare component (v) by dry blending the P FE and the fluorothermoplast. However, in the latter case, care should be taken that the shear forces applied in the blending operation do not cause the PTFE to fibrillate. Accordingly, blending should then typically be carried out at low temperatures at which fibrillation can be avoided. Once the PTFE is blended with an effective amount of the fluorothermoplast, fibrillation of the PTFE may be prevented and the melt additive can thus be handled in a conventional way. Component (v) may contain further adjuvants to obtain particular desired properties.

Component (v) comprising a polytetrafluoroethylene, a fluorothermoplast, or mixtures thereof is present in an amount equal to or greater than about 0.01 parts by weight, preferably equal to or greater than about 0.05 parts by weight, more preferably equal to or greater than about 0.1 parts by weight, more preferably equal to or greater than about 0.2 parts by weight, and more preferably equal to or greater than about 0.3 parts by weight based on the weight of the ignition resistant carbonate polymer composition. Component (v) comprising a polytetrafluoroethylene, a fluorothermoplast, or mixtures thereof is present in an amount equal to or less than about 5 parts by weight, preferably equal to or less than about 3 parts by weight, more preferably equal to or less than about 1 parts by weight, more preferably equal to or less than about 0.8 parts by weight, more preferably equal to or less than about 0.6 parts by weight, and more preferably equal to or less than about 0.5 parts by weight based on the weight of the ignition resistant carbonate polymer composition.

The ignition resistant carbonate polymer compositions according to the invention contains as component (vi) at least one of an additional polymer and/or conventional additive, such as a thermoplastic vinyl (co)polymer, an impact modifier, lubricants and mold release agents, for example low molecular weight ester, pentaerythritol tetrastearate, poly-alpha-olefins, or combinations thereof, nucleating agents, anti-static agents, stabilizers, fillers and reinforcing materials as well as dyes and pigments. One such stabilizer is present to rmnimize ester-carbonate interchange. Such stabilizers are known in the art, for example see USP 5,922,816; 4,532,290; 4,401,804, all of which are incorporated herein by reference, and may comprise certain phosphorous containing compounds that include phosphoric acid, certain organic phosphorous compounds such as distearyl pentaerythritol diphosphate, mono or dihydrogen phosphate, or mono-, di-, or trihydrogen phosphate compounds, phosphate compounds, and certain inorganic phosphorous compounds such as monosodium phosphate and monopotassium phosphate, silyl phosphates, and silyl phosphate derivatives, alone or in combination and present in an amount effective to inhibit ester-carbonate interchange in the composition.

If present, suitable thermoplastic vinyl (co)polymers are polymers of at least one monomer from the group comprising aromatic vinyl compounds, vinyl cyanides

(unsaturated nitrites), (meth)acrylic acid (Ci - Cg)-alkyl esters, unsaturated carboxylic acids, as well as derivatives (such as anhydrides and imides) of unsaturated carboxylic acids.

(Co)polymers which are particularly suitable are those of (a) in an amount of from 50 to 99, preferably 60 to 80 parts by weight of aromatic vinyl compounds and/or aromatic vinyl compounds which comprise substituted nuclei, such as styrene, alpha-methylstyrene, p-methylstyrene, p-chlorostyrene and/or methacrylic acid (Q - C- -alkyl esters, such as methyl methacrylate or ethyl methacrylate, and (b) in an amount of from 1 to 50, preferably 20 to 40 parts by weight vinyl cyanides (unsaturated nitrites) such as acrylonitrile and methacrylonitrile and/or (meth)acrylic acid (Q - Cg) esters (such as methyl methacrylate, n- butyl acrylate or t-butyl acrylate) and/or unsaturated carboxylic acids (such as maleic acid) and/or derivatives (such as anhydrides and imides) of unsaturated carboxylic acids (for example maleic anhydride and N-phenyl-maleimide).

The copolymer of (a) styrene and (b) acrylonitrile (SAN) is particularly preferred. (Co)polymers are thermoplastic and free from rubber. The (co)polymers are known and can be produced by radical polymerization, particularly by emulsion, suspension, solution or bulk (mass) polymerization. The (co)polymers preferably have molecular weights M_w (weight average, as determined by GPC using laser scattering techniques and narrow molecular weight polystyrene standards) between 15,000 and 200,000.

(Co)polymers according to the present invention are frequently produced as byproducts during the graft polymerization of component (ii), particularly when large amounts of monomers (ii.a.l) and (ii.a.2) comprising grafting copolymer (ii.a) are grafted on to small amounts of rubber (ii.b). The amount of (co)polymer which can also optionally be used according to the invention does not include these by-products of the graft polymerization of (ii). If a (co)polymer is present in the ignition resistant carbonate polymer compositions according to the invention, the ratio by weight of components (ii):(co)polymer may desirably be between 2:1 and 1:4, preferably between 1:1 and 1:2.

If present, the thermoplastic vinyl (co)polymer is present in an amount equal to or greater than about 0.5 parts by weight, preferably equal to or greater than about 1 part by weight, more preferably equal to or greater than about 2 parts by weight, more preferably equal to or greater than about 5 parts by weight, and more preferably equal to or greater than about 10 parts by weight based on the weight of the ignition resistant carbonate polymer composition. If present, the thermoplastic vinyl (co)polymer is present in an amount equal to or less than about 45 parts by weight, preferably equal to or less than about 40 parts by weight, more preferably equal to or less than about 35 parts by weight, more preferably equal to or less than about 30 parts by weight, and more preferably equal to or less than about 25 parts by weight based on the weight of the ignition resistant carbonate polymer composition.

If a vinyl thermoplastic (co)polymer is present in the ignition resistant carbonate polymer compositions according to the invention, the ratio by weight of components (ii):(iii) may desirably be between 2:1 and 1:4, preferably between 1:1 and 1:2.

The ignition resistant carbonate polymer compositions of the present invention may further comprise a filler and/or reinforcing material. Preferred fillers, which may also have a reinforcing action, are glass fibers, carbon fibers, metal fibers, metal coated fibers, thermoset fibers, glass beads, mica, silicates, quartz, talc, titanium dioxide, and/or wollastonite alone or in combinations.

If present, the filler and/or reinforcing material is present in an amount equal to or greater than about 0.5 parts by weight, preferably equal to or greater than about 1 part by weight, more preferably equal to or greater than about 2 parts by weight, more preferably equal to or greater than about 5 parts by weight, and more preferably equal to or greater than about 10 parts by weight based on the weight of the ignition resistant carbonate polymer composition. If present, the filler and/or reinforcing material is present in an amount equal to or less than about 60 parts by weight, preferably equal to or less than about 40 parts by weight, more preferably equal to or less than about 30 parts by weight, more preferably equal to or less than about 25 parts by weight, and more preferably equal to or less than about 20 parts by weight based on the weight of the ignition resistant carbonate polymer composition. The ignition resistant carbonate polymer composition of the present invention may further comprise an impact modifier, for example see USP 6,545,089 and US Publication 2007/0225441 which are incorporated herein by reference. Preferable impact modifiers are rubber materials having a T_g equal to or less than 0°C, preferably equal to or less than -10°C, more preferably equal to or less than -20°C, and most preferably equal to or less than -30°C. Suitable rubbers include polymers such as styrene and butadiene (SB) copolymer, acrylate rubbers, particularly homopolymers and copolymers of alkyl acrylates having from 4 to 6 carbons in the alkyl group or polyolefin elastomers, particularly copolymers of ethylene, propylene and optionally a nonconjugated diene. In addition, mixtures of the foregoing rubbery polymers may be employed if desired.

In one embodiment, the impact modifier is a grafted homopolymer or copolymer of butadiene that is grafted with a polymer of styrene and methyl methacrylate. Some of the preferred rubber-containing materials of this type are the known methyl methacrylate, butadiene, and styrene (MBS) core/shell grafted copolymers having a T_g equal to or less than 0°C and a rubber content greater than 40 percent, typically greater than 50 percent. They are generally obtained by graft polymerizing styrene and methyl methacrylate and or equivalent monomers in the presence of a conjugated diene polymer rubber core, preferably a butadiene homo- or co-polymer. The grafting monomers may be added to the reaction mixture simultaneously or in sequence, and, when added in sequence, layers, shells or wart- like appendages can be built up around the substrate latex, or core. The monomers can be added in various ratios to each other.

In another embodiment, the impact modifier is a silicon-based rubber. Silicon- based rubbers are well known in prior art, see US Patent Application Nos. 2007/0155857 and 2008/0090961, both of which are incorporated herein by reference. A particularly suitable silicon-based rubber is an emulsion polymerized core-shell rubber having in its core a combination of silicone and acrylate. Such silicon-based rubbers may be grafted by a wide variety of monomers such as styrene, acrylonitrile, methylmethacrylate,

butylacrylate, and the like. Desirable silicon-based rubbers are grafted with (meth)acrylates and have a high silicone ratio in their core above, preferably the silicon content is equal to · or greater than above 10 weight percent, more preferably equal to or greater than 20 weight percent.

Suitable silicon-based core-shell graft copolymer prepared by graft polymerization of a vinyl monomer onto a rubber containing about 20 to about 95 percent by weight of silicon. Methods for preparing a graft copolymer in the form of a silicon-based core-shell are well-known in the art and will be readily understood by a person skilled in the art. The graft copolymer suitable for the present invention can have a structure in which a vinyl monomer is grafted onto a core part of the rubber, thus forming a rigid shell. There is no particular limitation on the kind of the silicon-based core-shell copolymer used in the invention, and it may be prepared by conventional methods well-known in the art. For example, the silicon-based core-shell copolymer may be prepared by polymerizing a silicon-based rubber and then grafting one or more compounds selected from the group consisting of styrene, alpha-methylstyrene, halogen or alkyl substituted styrene, acrylonitrile, methacrylonitrile, Cj-Ce methacrylic acid alkylester, Q-Cg acrylic acid alkylester, maleic anhydride, C1-C4 alkyl and phenyl N-substituted maleimide onto the rubber. The Ci-Cg methacrylic acid alkylester and CpCg acrylic acid alkylester belong to esters of methacrylic acid and acrylic acid, respectively, which are esters derived from monohydril alcohol having 1 to 8 carbon atoms. Particular examples thereof may include methacrylic acid methylester, methacrylic acid ethylester and methacrylic acid propylester.

The rubber content of the silicon-based core-shell graft copolymer can be in the range of about 30 to about 90 percent by weight If the rubber content is lower than about 30 percent by weight, the flame retardance of the composition can deteriorate. Meanwhile, if the rubber content exceeds about 90 percent by weight, the impact resistance of the composition can decline.

The silicon-based rubber core may be made of cyclosiloxane, examples of which may include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane,

decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane,

trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrosiloxane,

octaphenylcyclotetrasiloxane, and the like, and mixtures thereof. The silicon-based rubber may be prepared by mixing the siloxane with one or more curing agents. Examples of suitable curing agents may include trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, and the like, and mixtures thereof.

The silicon content of the rubber part, which constitutes a core part of the composition in the present invention, can be in the range of about 20 to about 95 percent by weight. If the silicon content of the rubber part is lower than about 20 percent by weight, the flame retardance of the composition can be hindered, which can make it difficult to acquire levels of flame retardance required for products. Further, if the silicon content is greater than about 95 percent by weight, the impact resistance of the composition can be hampered, which may make it difficult to obtain impact strength required for products.

In addition, the silicon content to a total silicon-based core-shell graft copolymer may be in the range of about 6 to about 85.5 percent by weight. For example, the silicon content to a total silicon-based core-shell graft copolymer may be in the range of about 50 to about 85 percent by weight in terms of flame retardance and impact strength.

In the present invention, if a silicon-based core-shell graft copolymer is used, it is used in an amount of equal to or greater than 0.5 parts by weight, preferably equal to or greater than 1 part by weight, and more preferable equal to or greater than 2 parts by weight based on the weight of the ignition resistant carbonate polymer composition. If the content of the silicon-based core-shell graft copolymer is lower than about 0.5 parts by weight, its effect on impact strength may be insignificant. In the present invention, if a silicon-based core-shell graft copolymer is used, it is used in an amount of equal to or greater less than 20 parts by weight, preferably equal to or less than 15 parts by weight, more preferably equal to or less than 10 parts, and more preferable equal to or less than 5 parts by weight based on the weight of the ignition resistant carbonate polymer composition. If the content thereof is greater than about 20 parts by weight, mechanical strength such as tensile strength, flexural modulus and the like may be lowered.

Other impact modifiers useful in the compositions of this invention are those based generally on a long-chain, hydrocarbon backbone, which may be prepared predominantly from various mono- or dialkenyl monomers and may be grafted with one or more styrenic monomers. Representative examples of a few olefinic elastomers which illustrate the variation in the known substances which would suffice for such purpose are as follows: butyl rubber; chlorinated polyethylene rubber (CPE); chlorosulfonated polyethylene rubber; an olefin polymer or copolymer such as ethylene/propylene (EP) copolymer,

ethylene/styrene (ES) copolymer or ethylene/propylene/ diene (EPDM) copolymer, which may be grafted with one or more styrenic monomers; neoprene rubber; nitrile rubber, polybutadiene and polyisoprene.

If used, the impact modifier is preferably present in an amount of at least about 1 part by weight, preferably at least about 2 parts by weight, more preferably at least about 5 parts by weight, even more preferably at least about 7.5 parts by weight, and most preferably at least about 10 parts by weight based on the total weight of the polymer blend composition. Generally, the impact modifier is present in an amount less than or equal to about 30 parts by weight, preferably less than or equal to about 25 parts by weight, more preferably less than or equal to about 20 parts by weight, even more preferably less than or equal to about 15 parts by weight, and most preferably less than or equal to about 10 parts by weight based on the weight of the polymer blend composition.

The ignition resistant carbonate polymer compositions comprising components (i),

(ii), (iii), (iv), (v) and (vi) are produced by mixing the particular components in a known manner and melt-compounding and/or melt-extruding them at temperatures of from 200°C to 300°C in conventional units such as internal kneaders, extruders and twin-screw extruders.

The individual components may be mixed in a known manner both in succession and simultaneously and both at approximately 23°C (room temperature) and at a higher temperature.

The present invention accordingly also provides a process for the production of the ignition resistant carbonate polymer compositions.

By virtue of their excellent ignition resistance, in particular short burn time, and good mechanical properties and elevated heat resistance, the ignition resistant carbonate polymer compositions according to the invention are suitable for the production of fabricated articles of any kind, in particular those subject to stringent requirements with regard to mechanical properties and especially requiring good flow properties.

The ignition resistant carbonate polymer compositions of the present invention are thermoplastic. When softened or melted by the application of heat, the ignition resistant carbonate polymer compositions of this invention can be formed or molded into fabricated articles using conventional techniques such as compression molding, injection molding, gas assisted injection molding, calendaring, vacuum forming, thermoforming, extrusion and/or blow molding, alone or in combination. The ignition resistant polymer compositions can also be fabricated, formed, spun, or drawn into films, fibers, multi-layer laminates or extruded into sheets and/or profiles. Examples of fabricated articles which may be produced are: enclosures of all kinds, for example for domestic appliances such as juice extractors, coffee machines, food mixers, for office equipment, such as monitors, printers, copiers or cladding sheet for the building sector and automotive components. They may also be used in electrical engineering applications as they have very good electrical properties. The ignition resistant carbonate polymer compositions according to the invention may furthermore, for example, be used to produce the following fabricated articles or shaped articles: interior trim for rail vehicles, interior and exterior automotive applications, enclosures for electrical devices containing small transformers, enclosures for information dissemination and transmission devices, enclosures and cladding for medical purposes, massage devices and enclosures therefore, toy vehicles for children, sheet wall elements, enclosures for safety equipment, hatchback spoilers, thermally insulated transport containers, apparatus for keeping or caring for small animals, articles for sanitary and bathroom installations, cover grilles for ventilation openings, articles for summer houses and sheds, and enclosures for garden appliances. Preferred fabricated articles include housings or enclosures such as for: power tools, appliances, consumer electronic equipment such as TVs, VCRs, DVD players, web appliances, electronic books, etc., or housings or enclosures such as for: information technology equipment such as telephones, computers, monitors, fax machines, battery chargers, scanners, copiers, printers, hand held computers, flat screen displays, etc.

The present invention accordingly also provides the use of the ignition resistant carbonate polymer compositions according to the invention for the production of fabricated articles of all kinds, preferably those stated above, and the articles made from the ignition resistant carbonate polymer compositions according to the invention.

EXAMPLES

To illustrate the practice of this invention, examples of preferred embodiments are set forth below. However, these examples do not in any manner restrict the scope of this invention.

The compositions of Examples 1 to 7 and Comparative Examples A to Dare melt compounded in a Werner and Pfleiderer ZSK-25 25 mm twin-screw co-rotating extruder. The temperature profile from the hopper to the nozzle is 220°C to 265°C. Prior to compounding, the polycarbonate is dried for at least 4 hours at 120°C. A four feeder system is used: a mixture of polycarbonate and ABS pellets is fed via one feeder, powdered additives are added as a dry blend via a second feeder, the BAPP is added at 80°C via a liquid feeder, and the PET is added via a fourth feeder. The mold release agent is sprayed onto the polycarbonate pellets prior to feeding them into the extruder. The throughput is 10 kilograms per hour; the extrudate is cooled in a 50°C water bath and commuted to pellets. Mechanical and thermal property test specimens measuring 3.2mm thick are injection molded on a Demag IntElect 80/370-310 type electrical injection molding machine with the following parameters: Barrel Profile, nozzle to hopper: 290°C to 250°C ; Mold Temperature: 80°C; and Cycle Time: 57 seconds.

UL 94 burn test specimens measuring 1.5mm thick are injection molded on a Demag

IntElect 80/370-310 type electrical injection molding machine with the following parameters: Barrel Profile, nozzle to hopper: 235°C to 240"C ; Mold Temperature: 60°C; and Cycle Time: 39.5 seconds.

UL 94 burn test specimens measuring 2.5mm thick are injection molded on a Demag IntElect 80/370-310 type electrical injection molding machine with the following parameters: Barrel Profile, nozzle to hopper: 235°C to 240°C ; Mold Temperature: 60°C; and Cycle Time: 42 seconds.

The formulation content of Examples 1 to 7 and Comparative Examples A to D are given in Table 1, amounts are in parts by weight based on the total weight of the composition. In Table 1:

"PC" is a bisphenol-A polycarbonate homopolymer having a melt flow of 23 and commercially available as CALIBRE™ 300-23 from the Dow Chemical Company.

"mABS" is a mass polymerized acrylonitrile, butadiene, and styrene terpolymer having about 20 percent acrylonitrile, 15 percent butadiene rubber, and an average rubber particle size (Dv) as determined by Coulter Counter of 1.15 microns;

"eABS" is an emulsion polymerized acrylonitrile, butadiene, and styrene terpolymer having about 12 percent acrylonitrile and 48 percent butadiene rubber;

"SAN" is a styrene and acrylonitrile copolymer comprising 75 percent styrene and 25 acrylonitrile having a melt flow rate of 4.5 (determined at 230°C under a load of 3.8kg);

"PET-1" is a semi-crystalline polyethylene terephthalate with an intrinsic viscosity of 0.64 dl/g available as PET LIGHTER™ C73 from Equipolymer;

"PET-2" is a semi-crystalline polyethylene terephthalate with an intrinsic viscosity of 0.80 dl g available as PET LIGHTER C93 from Equipolymer;

'ΈΑΡΡ' is an oligomeric phosphate flame retardant comprising bisphenol-A bis(diphenyl phosphate) having an average 'n' value of about 1.13 available as REOFOS™ BAPP from Chemtura Corporation; "PTFE-1" is an anti-drip agent comprising a mixture if a fibril forming

polytetrafluoroethylene polymer and a fluorothermoplast available as DYNEON™

MM5935EF from 3M;

"PTFE-2" is an anti-drip agent comprising a fibril forming polytetrafluoroethylene having an average particle size of 550 microns, a bulk density of 500 g 1, a specific gravity of 2.17, and a Rheometric Pressure of 8 MPa according to ASTM D4895 available as ALGOFLON™ DF210 from Solvay;

"MRA" is a liquid mold release agent comprising octyldodecyl stearate available as LOXIOL™ 3820 from Cognis; and

"ANTIOX" is a phenolic antioxidant available as IRGANOX™ 1076 from Ciba

Geigy.

Property performance for Examples 1 to 7 and Comparative Examples A to D are reported in Table 1. In Table 1:

"UL-94" is The Underwriters Laboratories' Standard 94 flammability test which is performed on 1.5 millimeter (mm) and 2.5mm test specimens. Ratings are according to the standard;

"HDT" is heat deflection temperature determined at 1.80 MPa according to ISO 75A using a Ceast heat deflection temperature apparatus;

"Vicat" softening temperature is determined on a Ceast HDT 300 Vicat machine in accordance with ISO 306 at 120° per hour and 1 kg;

"Spiral Flow" flow length measured in mm is determined on a Demag IntElect 80/370 - 150 having a screw diameter of 25mm using an open spiral mold with the following dimensions: Total potential length: 117cm; Thickness: 2mm; and Width: 5mm. The injection molding conditions are:

Temperature, °C @ 240 or 260

Injection Pressure, Bar 1,200

Injection Speed, mm/sec 100

Holding Time, sec 0.5

Holding Pressure, Bar 300

Cooling Time, sec 25

Rotation Per Minute (RPM) 100

Back Pressure, Bar 120

Dosing, mm 24 "Izod" impact resistance as measured by the Notched Izod test (Izod) is determined according to ISO 180/lA at 23°C. Test specimens measured 10 mm x 80 mm x 4 mm. The specimens were notched with a notcher to give a 250 micrometer radius notch. A Zwick 5110 Izod impact testing unit was used; and

'Tensile Strength", "Tensile Rupture", 'Tensile Elongation", and 'Tensile

Modulus" property testing is done in accordance with ISO 527 at room temperature using an Zwick 1455 mechanical tester, tensile strength and elongation are performed at a rate of 50 mm min and tensile modulus is performed at a rate of lmm/min.

Table 1

As can be seen by the data hereinabove, the examples of the invention comprising the low viscosity semi-crystalline polyester and a mass polymerized graft copolymer demonstrate a better combination of flammability, physical, thermal, and flow length performance as compared to the comparative examples comprising the high viscosity polyester and/or emulsion polymerized graft copolymer.

Claims

CLAIMS:

1. An ignition resistant carbonate polymer composition consisting of:

(i) an aromatic polycarbonate or an aromatic polyester carbonate,

(ii) a graft (co)polymer produced by mass polymerization,

(iii) a thermoplastic semi-crystalline polyalkylene dicarboxylate polymer having an intrinsic viscosity of from 0.4 to 0.7 dl/g,

(iv) an aromatic hosphorous compound represented by the formula I:

wherein,

R¹, R², R³ and R⁴ independently of one another each denote optionally halogenated d- to Cg-alkyl, or C5- to C6- cycloalkyl, Ce- to C20- aryl or C₇- to C12- aralkyl, in each case optionally substituted by alkyl and/or halogen,

X denotes a mono- or polynuclear aromatic radical having 6 to 30 C atoms, n independently of one another is 0 or 1 ,

N represents values from 0 to 30,

(v) a polytetrafluoroethylene polymer, a fluorothermoplast, or mixture thereof, and

(vi) one or more of a thermoplastic vinyl (co)polymer, an impact modifier, a filler, a reinforcing material, a stabilizer, a pigment, a dye, a mold release, a lubricant, or an anti-static agent.

2. An ignition resistant carbonate polymer composition consisting of:

(i) from 30 to 75 parts by weight of an aromatic polycarbonate or an aromatic polyester carbonate,

(ii) from 5 to 60 parts by weight of a graft (co)polymer produced by mass polymerization of

(ii.a) from 5 to 99 percent by weight of a grafting (co)polymer comprising one or more vinyl monomers on (ii.b) from 95 to 1 percent by weight of one or more a grafting backbone having a glass transition temperature (T_g) of less than 10°C wherein percents by weight are based on the total weight of the graft (co)polymer,

(iii) from 5 to 45 parts by weight of a thermoplastic semi-crystalline

polyalkylene dicarboxylate polymer having an intrinsic viscosity of from 0.4 to 0.7 dl/g,

(iv) from 2 to 20 parts by weight of an aromatic phosphorous compound represented b the formula I:

wherein in the formula I,

R¹, R², R³ and R⁴ independently of one another each denote optionally halogenated C_\- to Cs-alkyl, or C5- to C6- cycloalkyl, Ce- to C20- aryl or C₇- to C₁₂- aralkyl, in each case optionally substituted by alkyl and/or halogen,

N represents values from 0 to 30,

(v) from 0.01 to 5 parts by weight of a pol tetrafluoroethylene polymer, a fluorothermoplast, or mixture thereof,

and

(vi) one or more of an impact modifier, a stabilizer, a pigment, a dye, a mold release agent, a lubricant, or an antistatic agent,

wherein parts by weight are based on the total weight of the ignition resistant carbonate polymer composition.

3. The ignition resistant carbonate polymer composition of Claim 1 wherein X is derived from a diol selected from diphenylphenol, bisphenol A, resorcinol, or hydroquinone.

4. The ignition resistant carbonate polymer composition of Claim 1 wherein the phosphorous compound (iv) comprises a mixture of from 3 to 95 weight percent monophosphate compound of formula I and 97 to 5 weight percent oligomeric phosphate compound of formula I, weight percent based on the total weight of the phosphorus compounds (iv).

5. The ignition resistant carbonate polymer composition of Claim 1 wherein (v) is a mixture of fibril forming polytetrafluoroethylene polymer and fluorothennoplast present in an amount of from 0.1 to 3 parts by weight based on the total weight of the ignition resistant carbonate polymer composition.

6. The ignition resistant carbonate polymer composition of Claim 5 wherein in component (v) the fluorothennoplast comprises a polymer of interpolymerized units derived from tetrafluoroethylene (TFE) and hexafluoropropylene (HFP), a polymer of

interpolymerized units derived from TFE, HFP and vinylidenefluoride (VDF), a polymer of interpolymerized units derived from TFE, HFP and a monomer represented by formula VI, or a polymer derived from interpolymerized units derived from TFE and a monomer represented by formula VI:

R⁸ ₂C=CR⁸2 VI

wherein each of R⁸ is independently selected from H, CI, or an alkyl group of from 1 to 8 carbon atoms, a cyclic alkyl group of from 1 to 10 carbon atoms, or an aryl group of from 1 to 8 carbon atoms.

7. The ignition resistant carbonate polymer composition of Claim 5 wherein in component (v) the fluorothennoplast comprises a terpolymer having interpolymerized units derived from tetrafluoroethylene (TFE), hexafluoropropylene (HFP) and vinylidenefluoride (VDF).

8. A method for making an ignition resistant carbonate polymer composition comprising the step of melt-compounding:

(ii) from 5 to 60 parts by weight of a graft (copolymer produced by mass polymerization of

(ii.a) from 5 to 99 percent by weight of a grafting (co)polymer comprising one or more vinyl monomers on

(ii.b) from 95 to 1 percent by weight of one or more a grafting backbone having a glass transition temperature (T_g) of less than 10°C, (iii) from 5 to 45 parts by weight of a thermoplastic semi-crystalline

polyalkylene dicarboxylate polymer having an intrinsic viscosity from 0.4 to 0.7 dl g,

(iv) from 2 to 20 parts by weight of an aromatic phosphorous compound represented b the structure:

wherein in the formula I,

R¹, R², R³ and R⁴ independently of one another each denote optionally halogenated Ci- to C8-alkyl, or C5- to Q_>- cycloalkyl, Ce~ to C20- aryl or C₇- to C12- aralkyl, in each case optionally substituted by alkyl and/or halogen,

X in the formula I denotes a mono- or polynuclear aromatic radical having 6 to 30 C atoms,

n in the formula I independently of one another can be 0 or 1,

N represents values from 0 to 30,

(v) from 0.01 to 5 parts by weight of a polytetrafluoroethylene polymer, a fluorothermoplast, or mixture thereof,

and

(vii) one or more of an impact modifier, a filler, a fiber, a stabilizer, a pigment, a mold release, a flow aid, or an antistatic agent,

9. A formed article comprising the ignition resistant carbonate polymer composition of Claim 1.

10. The formed article of Claim 9 is an interior trim for rail vehicle, an interior and/or exterior automotive article, an enclosure for electrical devices containing small transformers, an enclosure for information dissemination and or transmission device, an enclosure and/or cladding for medical purposes, a message device and/or enclosures therefore, a toy vehicles for children, a sheet wall element, an enclosure for safety equipment, a hatchback spoiler, a thermally insulated transport container, an apparatus for keeping and/or caring for small animals, an article for sanitary and/or bathroom installations, a cover grill for ventilation openings, an article for summer houses and sheds, enclosures for garden appliances and/or an enclosure for: a power tool, an appliance, a TV, a VCR, a DVD player, a web appliance, an electronic book, a telephone, a computer, a monitor, a fax machine, a battery charger, a scanner, a copier, a printer, a hand held computer, or a flat screen display.