WO2002018485A1

WO2002018485A1 - Flame-retarded polyphenylene ether composition and method of making same

Info

Publication number: WO2002018485A1
Application number: PCT/US2001/020593
Authority: WO
Inventors: Nirajkumar Patel
Original assignee: General Electric Company
Priority date: 2000-08-31
Filing date: 2001-06-28
Publication date: 2002-03-07
Also published as: AU2001273053A1

Abstract

Polyphenylene ether (PPE) compositions with good fire and flame retardant characteristics utilize lower levels of organophosphate fire-retardant, and therefore do not suffer from the drawbacks of previously known fire- and flame-retardant PPE compositions. The compositions include (a) a polymer component containing a polyphenylene ether; (b) glass or carbon reinforcing fibers in an amount sufficient to increase the modulus and strength of the polymer component; (c) a fire retardant component which is preferably an organophosphate fire retardant; (d) a mineral component in an amount effective to enhance the flame-retardant characteristics of the composition. Other conventional additives utilized in formulation of PPE may be included. The composition is made by mixing the ingredients and compounding into a composition which is suitable for injection molding. This composition can be used in the manufacture of injection molded articles such as electronic components, including television internals such as deflection yokes; printer chassis and plastic pallets.

Description

FLAME-RETARDED POLYPHENYLENE ETHER COMPOSITION AND

METHOD OF MAKING SAME

BACKGROUND OF THE INVENTION

This application relates to a flame-retarded polyphenylene ether (PPE) compositions and to a method of making same.

PPE is a thermoplastic material with high glass transition temperature, high dimensional stability, low specific gravity, hydrolytic stability and good mechanical performance. This combination of properties allows PPE based formulations to be injected molded into products which are used for high heat applications, for example in the automotive, electrical, and construction industries. For some applications, where increased modulus and strength are required, PPE may be reinforced with glass or carbon fibers. However, these reinforced PPE formulations have undesirable flammability characteristics. At high temperature or when exposed to flame, glass or carbon filled PPE tends to burn continuously without extinguishing. Because of this, fire- retarded grades of glass or carbon filled PPE (especially those rated UL94 V0) tend to be formulated using a large amount (for example >15% by weight for a rating of UL94 V0 at l/16th inch thickness) of fire-retardant additives such as phosphorus-containing organic compounds. This increases the cost of the product, and also makes it more difficult to formulate glass or carbon fiber reinforced PPE to meet UL94 V0 fire-retardant standards, because the addition of such large amounts of phosphorus-containing organic compounds like resorcinol diphosphate plasticizes the composition thereby significantly reducing the heat deflection temperature of the formulation. SUMMARY OF THE INVENTION

The present invention provides PPE compositions with good fire and flame-retardant characteristics, which utilize lower levels of organophosphate fire-retardant and which therefor do not suffer from the drawbacks of previously known fire- and flame-retardant PPE compositions. The compositions comprise

(a) a polymer component comprising a polyphenylene ether;

(b) glass or carbon reinforcing fibers in an amount sufficient to increase the modulus and strength of the polymer component;

(c) a fire retardant component, preferably comprising an organophosphate fire retardant; and

(d) a mineral filler component in an amount effective to enhance the flame-retardant characteristics of the composition.

Other conventional additives utilized in formulation of PPE may be included. This composition can be used in the manufacture of injection molded articles such as electronic components, including television internals such as deflection yokes; printer chassis and plastic pallets.

The present invention further provides a method for preparation of a glass or carbon reinforced PPE composition. In accordance with this method, the composition is prepared by compounding a mixture of

(a) a polymer component comprising a polyphenylene ether;

(b) glass or carbon reinforcing fibers in an amount sufficient to increase the modulus and strength of the polyphenylene ether matrix; (c) a fire retardant component, preferably comprising an organophosphate fire retardant; and

This compounding is suitably carried out in a screw type extruder at a temperature of 520 to 620 °F, preferably from 540 to 560 °F.

DETAILED DESCRIPTION OF THE INVENTION

The PPE compositions of the present invention comprise a polymer component comprising a polyphenylene ether (PPE); glass or carbon reinforcing fibers in an amount sufficient to increase the modulus and strength of the polyphenylene ether matrix; a fire retardant component, preferably an organophosphate fire retardant component; and a mineral filler component in an amount effective to enhance the flame-retardant characteristics of the composition. These components act synergistically to provide glass or carbon fiber reinforced PPE with good fire and flame- retardant characteristics, which utilize lower levels of organophosphate fire- retardant and which therefore do not suffer from the drawbacks of previously known fire- and flame-retardant PPE compositions.

This synergism is demonstrated in the results of the tests described below in the Examples which are summarized in Tables 1 and 3 - 6. In these tests, samples of glass or carbon fiber reinforced PPE were prepared by compounding in a twin screw extruder. Some of the compositions were prepared with a mineral component and others without a mineral component and some utilized the substitution of glass beads for the mineral filler, keeping the weight fraction of filler constant for a given set of experiments. The samples were then injection molded and tested for flame-out time in accordance with the UL protocol for V0 rating.

The experiments indicated that addition of small amounts of a mineral component to fire-retardant glass-fiber reinforced PPE allowed achievement of enhanced fire-retardant performance and compliance with the UL94 V0 standard. Table 6 demonstrates that this same type of synergy also exists when the PPE is reinforced with carbon fibers as a substitute for glass fibers. Thus, it is clear that there is a critical and synergistic combination of ingredients which leads to the improved characteristics of the compositions of the present invention.

The composition of the invention is made from a polymer component in which various fillers and additives are incorporated. As used herein, the term "polymer component" refers to the combined mass of all organic polymers present in the composition. While the polymer component may be 100% of a polyphenylene ether, it may also include other polymers selected to achieve desired properties in the final composition. Thus, the polymer component of the composition comprises at least 10%, preferably at least 20%, more preferably at least 35 % and most preferably at least 50% by weight of one or more species of polyphenylene ether. As used herein, the term "polyphenylene ether" refers to individual polymeric PPE species or to mixtures of polymeric PPE species unless the context indicates otherwise.

PPE useful in the present invention is a polymer having repeat units of the general formula 02/18485

wherein in the formula, Ri, R2, R3, and R4 which may be the same or different each represent a member selected from the group consisting of hydrogen atoms, halogen atoms, substituted and unsubstituted alkyl groups and substituted and unsubstituted alkoxy groups. The PPE may be a homopolymer, i.e. the repeat units have the same structural formula, or a copolymer consisting of a combination of two or more types of repeat units where at least one of the Ri, R2, R3, and R4 are different for each different repeat unit comprising the copolymer. The polymer is terminated at each end by a monovalent chemical group or atom such as hydrogen, a halogen, a monovalent hydrocarbon radical (saturated, unsaturated or aromatic) or the like. There are no particular restrictions on the method of manufacturing PPE. For example, this may be produced by reacting phenols according to the procedures presented in the specifications of U.S. Pat. Nos. 3,306,874, 3,257,357, or 3,257,358. Examples of these phenols include 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-dibutylphenol, 2,6-dilaurylphenol, 2,6-dipropylphenol, 2,6-diphenylphenol, 2-methyl-6-ethylphenol,

2-methyl-6-cyclohexylphenol, 2^:methyl-6-tolyl-phenol,

2-methyl-6-methoxyphenol, 2-methyl-6-butylphenol, 2,6-dimethoxyphenol, 2,3,6-trimethylphenol, 2,3,5,6-tetramethylphenol, 2,6-diethoxyphenol, etc., but the invention is not limited to these. One may either use a corresponding homopolymer obtained by reacting one of the above substances or a corresponding copolymer obtained by reacting two or more of the above substances and having the different units contained in the above formula. Specific examples of PPE polymers useful in the invention include but are not 02/18485

limited to poly(2,6-dimethyl-l,4-phenyIene) ether, poly(2,6-diethyl-l,4-phenylene) ether,

ρoly(2-methyl-6-ethyl-l,4-phenylene) ether, poly(2-methyl-6-propyl-l,4-phenylene) ether, poly(2,6-dipropyl-l,4-phenylene) ether, and poly(2-ethyl-6-propyl-l,4-phenylene) ether. Moreover, an example of the PPE copolymer is a copolymer partially containing an alkyl trisubstituted phenol such as 2,3,6-trimethylphenol in the aforementioned polyphenylene ether repeated unit. The PPE resins may also be copolymers having a styrene compound grafted on. An example of such a styrene-compound-grafted polyphenylene ether is a copolymer obtained by graft polymerization of a styrene compound such as styrene, alpha-mefhylstyrene, vinylstyrene, or chlorostyrene onto the aforementioned PPE.

Additional polymeric materials which may be included, individually or in combination, in the polymer component of the invention include crystalline polystyrene which can be added in amounts of 0 to 80 % by weight of the polymer component to improve processability, high impact polystyrene

(HIPS) , which can be added in amounts of 0 to 80 % by weight of the polymer component to improve processability and increase impact strength; styrene- butadiene block copolymers which can be added in amounts of 0 to 30 % by weight of the polymer component to improve the impact properties of the polymer component; and polyamides such as nylon-6,6 and nylon-6 which can be added in amounts of 0 to 80% by weight of the polymer component to improve melt flow and impart increased resistance to organic solvents. The polymeric component may also include a terpene phenol resin (i.e, a copolymer of monoterpenes and phenol such as NIREZ 2150/7042™) or a hydrocarbon polymer (e.g. Arkon P-125) in amounts of 0 to 25 % by weight of the polymeric component to provide better flow to the composition. Other 02/18485

polymers that can be blended in the compositions of the invention include polyphenylene sulfides in amounts from 0 to 50 % by weight to improve heat deflection temperature and the flow.

Glass fibers suitable for use in the compositions of the invention may be of various lengths appropriate and thicknesses appropriate to the application. Coatings of coupling agents, such as aminosilanes may be employed if desired. The glass fibers are added in an amount sufficient to increase the modulus and the strength of the product by a desired amount, and persons skilled in the art will be able to judge the appropriate levels and type of glass fiber needed to achieve a given result.

Carbon fibers suitable for use in the compositions of the invention may be of various lengths appropriate and thicknesses appropriate to the application. Appropriate surface treatment and/ or binders may be employed if desired. The carbon fibers are added in an amount sufficient to increase the modulus and the strength of the product by a desired amount, and persons skilled in the art will be able to judge the appropriate levels and type of carbon fiber needed to achieve a given result.

The polyphenylene ether resin blends of this invention can be rendered flame retardant with the use of flame retardant additives known in the art including halosubstituted diaromatic compounds such as 2,2-bis-(3,5- dichlorophenyl)propane, as described in U.S. Pat. No. 5,461,096 and phosphorous compounds as described in U.S. Pat. No. 5,461,096. Other examples of halosubstituted diaromatic flame retardant additives include brominated benzene, chlorinated biphenyl, brominated polystyrene, chlorine containing aromatic polycarbonates or compounds comprising two phenyl radicals separated by a divalent alkenyl group and having at least two chlorine or two bromine atoms per phenyl nucleus, and mixtures thereof. 02/18485

The preferred flame retardant compounds employed in the compositions of the present invention are free of halogen. These preferred compounds include phosphorous compounds selected from elemental phosphorous, organic phosphonic acids, phosphonates, phosphinates, phosphinites, phosphine oxides such as triphenylphosphine oxide, phosphines, phosphites and phosphates. Typical of the preferred phosphorous compounds are those of the general formula:

and nitrogen analogs of these phosphorous compounds. Each Z represents the same or different radicals including hydrocarbon radicals such as alkyl, cycloalkyl, aryl, alkyl substituted aryl and aryl substituted alkyl; halogen, hydrogen, and combinations thereof provided that at least one of said Qs is aryl. More preferred are phosphates wherein each Q is aryl. Other suitable phosphates include diphosphates and polyphosphates having the following formulae

where Ar is phenyl, biphenyl with a lower alkyl bridge or triphenyl, each Ri is independently hydrocarbon; R₂, R₆ and R are independently hydrocarbon or hydrocarbonoxy, each X¹ is either hydrogen methyl, methoxy or halogen, m is an integer of from 1 to 4; and n is an integer of from about 1 to 30. Preferably, each Ri is independently phenyl or lower alkyl of from 1 to 6 carbon atoms and R2, Rό and R7 are each independently phenyl, lower alkyl of 1 to 6 carbon atoms, phenoxy or (lower) alkoxy of from 1 to 6 carbon atoms.

Examples of suitable phosphates include phenylbisdodecyl phosphate, phenylbisneopentyl phosphate, phenylethylene hydrogen phosphate, phenyl- bis-3,5,5'-trimethylhexyl phosphate, ethydiphenyl phosphate, 2-ethylhexyl di(p-tolyl), phosphate, diphenyl hydrogen phosphate, bis(2-ethyl-hexyl) p- tolylphosphate, tritolyl phosphate, bis(2-ethylhexyl)-phenyl phosphate, tri(nonylphenyl) phosphate, phenyl-methyl hydrogen phosphate, di(dodecyl) p-tolyl phosphate, tricresyl phosphate, triphenyl phosphate, isopropylated triphenyl phosphate, halogenated triphenyl phosphate, dibutylphenyl phosphate, 2-chlorethyldiphenyl phosphate, p-tolyl bis(2,5,5'-trimethylhexyl) phosphate, 2-ethylhexyldiphenyl phosphate and the like.

The most preferred phosphates are triphenyl phosphate, the alkylated triphenyl phosphates, including isopropylated and butylated triphenyl phosphates, bis-neopentyl piperidinyl diphosphate, tetraphenyl bisphenol-A diphosphate, tetraphenyl resorcinol diphosphate, hydroquinone diphosphate, bisphenol-A diphosphate, bisphenol-A polyphosphate, mixtures of these compounds and derivatives of these compounds.

Suitable compounds containing a phosphorus-nitrogen bond include phosphonitrilic chloride, phosphorus ester amides, phosphoric acid- mides, phosphonic acid amides, and phosphinic acid amides. Bis-phosphoramide materials derived from piperazine and hydroxy aromatic compounds are especially useful.

The level of flame retardant added to the PPE resin blends of this invention can range from 1 to 30 wt%. A preferred level for the phoshorous flame retardants is from 1% to 20% by weight of the composition, a more preferred level is from 7% to 20% by weight of the composition, a most preferred level is from 10% to 30% by weight of the composition. In some embodiments it is preferable to use the phoshorous flame retardants such as triphenyl phosphate in combination with other flame retardants such as hexabromobenzene and optionally antimony oxide.

Suitable phosphorous flame retardant additives are commercially available and methods for preparing the phosphate flame retardants are generally known in the art. As an example, the compounds may be prepared by reacting a halogenated phosphate compound with various dihydric or trihydric phenolic compounds until the desired number of phosphate functional groups are obtained. Examples of the phenolic compounds are dihydroxy aromatic compounds such as resorcinol and hydroquinone.

The fire retardant component of the compositions may be a halogenated fire retardant such as brominated polystyrene. Although halogenated flame retardant compounds may be used with the compositions of the present invention, ecologically-preferred compositions, however, are halogen-free and preferably utilize an organophosphate fire retardant. The organophosphate fire retardant component of the compositions may be any of numerous organophosphorus fire retardants that are known in the art. Specific examples include resorcinol diphosphate, bisphenol A diphosphate, tetraxylyl piperazine diphosphamide and the like, e.g. such as disclosed in US patents 4,933,386; 4,343,732; 5,455,292 and RE 36,188 herein and herewith specifically incorporated by reference. The amount of organophosphate fire retardant is selected to achieve the desired final level of fire-retardance.

In general, mineral fillers are added in flame retarding amounts that range from about 0.5 to about 30 weight percent, preferably from about 1 to about 10 weight percent, more preferably from about 1 to about 5 weight percent, and most preferably from about 1 to about 3 weight percent.

The mineral component may be selected among others from the group consisting of mica, clay, wollastonite, silica, barium sulfate, calcium carbonate, titanium dioxide and talc. When clay is used is used it is preferably kaolin.

While not intending to be bound by a particular mechanism of action, it is believed that replacement of glass or carbon fibers by mineral or titanium dioxide reduces the heat transfer coefficient of the composite and helps in char formation, thereby improving flame retardancy. It is believed that glass beads, although they may reduce the heat transfer coefficient, do not help in char formation to a great extent. Thus, use of glass beads in glass/ carbon fiber reinforced PPE does not seem to be as effective as the use of minerals (described later) or titanium dioxide in enhancing flame retardancy of the resulting formulations.

Materials which enhance the impact strength of the PPE resin blends of this invention are not critical but are often desirable. Suitable materials include natural and synthetic elastomeric polymers such as natural rubbers, synthetic rubbers and thermoplastic elastomers. They are typically derived from monomers such as olefins (e.g., ethylene, propylene, 1-butene, 4-methyl-l- pentene) alkenylaromatic monomers, (e.g., styrene and alphamethyl styrene) conjugated dienes (e.g., butadiene, isoprene and chloroprene) and vinylcarboxylic acids and their derivatives (e.g., vinylacetate, acrylic acid, alky lacry lie acid, ethylacrylate, methyl methacrylate acrylonitrile). They may be homopoϊymers as well as copolymers including random, block, graft and core shell copolymers derived from these various suitable monomers discussed more particularly below.

Polyolefins which can be included within the PPE resin blends of this invention are of the general structure: C_nH2n and include polyethylene, polypropylene and polyisobutylene with preferred homopolymers being polyethylene, LLDPE (linear low density polyethylene), HDPE (high density polyethylene) and MDPE (medium density polyethylene) and isotatic polypropylene. Polyolefin resins of this general structure and methods for their preparation are well known in the art and are described for example in U.S. Patent Nos. 2,933,480, 3,093,621, 3,211,709, 3,646,168, 3,790,519, 3,884,993, 3,894,999, 4,059,654, 4,166,055 and 4,584,334. Copolymers of polyolefins may also be used such as copolymers of ethylene and alpha olefins like propylene and 4-methylpentene-l. Copolymers of ethylene and C3-C10 monoolefins and non-conjugated dienes, herein referred to as EPDM copolymers, are also suitable. Examples of suitable C3-C10 monoolefins for EPDM copolymers include propylene, 1-butene, 2-butene, 1- pentene, 2-pentene, 1-hexene, 2-hexene and 3-hexene. Suitable dienes include 1,4 hexadiene and monocylic and poly cyclic dienes. Mole ratios of ethylene to other C3-C10 monoolefin monomers can range from 95:5 to 5:95 with diene units being present in the amount of from 0.1 to 10 mol%. EPDM copolymers can be functionalized with an acyl group or electrophilic group for grafting onto the polyphenylene ether as disclosed in U.S. Patent No. 5,258,455.

When polyolefins are typically present they are present in an amount from about 0.01% to about 20% by weight based on the total weight of the composition. Where the polyolefin is EPDM, the amount is generally from 0.25% by weight to about 3% by weight of the composition.

Suitable materials for impact modification include conjugated diene homopolymers and random copolymers. Examples include polybutadiene, butadiene-styrene copolymers, butadiene-acrylate copolymers, isoprene- isobutene copolymers, chlorobutadiene polymers, butadiene acrylonitrile polymers and polyisoprene. These impact modifiers may comprise from about 0.5 to 30 weight percent of the total composition.

A particularly useful class of impact modifiers with conjugated dienes comprises the AB (di-block), (AB)_m-R (di-block) and ABA' (tri-block) block copolymers. Blocks A and A' are typically alkenyl aromatic units and Block B is typically conjugated diene units. For block copolymers of the formula (AB)m-R, integer m is at least 2 and R is a multifunctional coupling agent for the blocks of the structure AB. 02/18485

Also useful are core shell graft copolymers of alkenylaromatic and conjugated diene compounds. Especially suitable are those comprising styrene blocks and butadiene, isoprene or ethylene-butylene blocks. Suitable conjugated diene blocks include the homopolymers and copolymers described above which may be partially or entirely hydrogenated by known methods, whereupon they may be represented as ethylene-propylene blocks or the like and have properties similar to those of olefin block copolymers. The suitable alkenyl aromatics include styrene, alpha-methyl styrene, para-methyl styrene, vinyl toluene, vinyl xylene and vinyl naphthalene. The block copolymer preferably contains from about 15 to 50% alkenyl aromatic units. Examples of triblock copolymers of this type are polystyrene-polybutadiene-polystyrene (SBS), hydrogenated polystyrene-polybutadiene-polystyrene (SEBS), polystyrene-polyisoprene-polystyrene (SIS) and poly(alpha-methylstyrene)- polyisoprene - poly(alpha-methylstyrene). Examples of commercially available triblock copolymers are the CARIFLEX®, KRATON® D and KRATON® G series from Shell Chemical Company.

Also included are impact modifiers comprising a radial block copolymer of a vinyl aromatic monomer and a conjugated diene monomer. Copolymers of this type generally comprise about 60 to 95 wt% polymerized vinyl aromatic monomer and about 40 to 5 wt% polymerized conjugated diene monomer. The copolymer has at least three polymer chains which form a radial configuration. Each chain terminates in a substantially non-elastic segment, to which the elastic polymer segment is joined. These block copolymers are sometimes referred to as "branched" polymers as described in U.S. Patent No. 4,097,550 and are used in amounts analogous to other conjugated diene based impact modifiers.

Examples of suitable flow promoters and plasticizers include the phosphate plasticizers such as cresyl diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, isopropylated and triphenyl phosphate. Terepene phenol, saturated alicyclic hydrocarbons, chlorinated biphenols and mineral oil are also suitable. When used, the plasticizers are typically employed in an amount of 0.25-25.0 wt% based on the weight of the composition depending on type of flow promotes and plasticizers used.

Suitable antioxidants include hydroxyl amines, hindered phenols such as alkylated monophenols and polyphenols, benzofuranones such as 3 aryl benzolfuranone, alkyl and aryl phosphites such as 2,4-di-tert butyl phenol phosphite and tridecyl phosphite, and hindered amines such as dioctyl methylamine oxide and other tertiary amine oxides. Such antioxidants are preferably used in an amount of 0.1 to 1.5 wt%, based on the weight of the composition.

Suitable U.V. stabilizers include 4,6- dibenzoyl resorcinols, alkanol amine morpholenes and benzotriazole.

Other additives can be included in the compositions of the invention in accordance with conventional practice in the art. For example, stabilizers such as sterically hindered phenols, organic phosphites, diazide oxalates, sterically hindered amines or amine N- oxides may be incorporated. Other exemplary additives include ZnS which functions to deactivate residual copper-based catalyst present in PPE, MgO or ZnO which function as an acid quencher to quench acid generated by the deactivation of residual catalyst, and carbon black or other colorant which functions as a pigment to color the composition. Additives may also be added to the composition for mold release or to reduce viscosity, for example some of the various forms of polyethylene such as HDPE, LDPE and LLDPE. The invention will now be further described with reference to the following, non-limiting examples. All US patents referenced herein are herewith specifically incorporated by reference.

Experimental Description

Samples of glass fiber-reinforced PPE were prepared with and without various loadings of mineral filler. The materials used in each sample are summarized in Table 1, where 0.40 IV PPE refers to a PPE homopolymer prepared by an oxidative coupling process and having an intrinsic viscosity of 0.40; Arkon P-125 is a saturated alicyclic hydrocarbon (Mw = 750) available from Arawaka Chemical Industries; LLDPE is a linear low density- polyethylene obtained from Exxon Chemicals; BPA-DP-FR (bis-phenol-A diphosphate) is a diphosphite ester of bis-phenol-A used as a flame retardant obtained from Akzo Nobel Chemical, Inc.; OCF R22Y K-filament glass fibers are 4 mm long, 14 micron diameter glass fibers sized with an amino silane coupling agent and a urethane film former obtained from Owens-Corning

Fiberglas; Mica Suzorite 200HK is a preparation of special delaminated pure phlogopite mica having a median particle size of 45 microns obtained from Zemex Industrial Minerals, Inc.; Talc Cimpact 610 C is talc obtained from Luzenac America Inc.; Wollastonite Orleans 325 is wollastonite obtained from Orleans, Inc.; Minco Min-Sil 20 is an amorphous fused silica obtained from Minco Corp. ; US Silica (Minusil) is a crystalline fused silica available from US Silica; glass beads are available from Ferro Bedford Chemical; barium sulfate is obtained from Zemex Industrial Minerals; untreated nano-clay is obtained from Nanocore; Huber 90G is a clay available from the J. M. Huber Corp.; Titanium dioxide is titanium dioxide obtained from DuPont; phosphite 168 stabilizer is tris-(2,4-di-f-butylphenyl) phosphite which acts as a thermal stabilizer and antioxidant and which is available from various sources including Argus Chemical, Witco, Great Lakes Chemical and Ciba Specialty Chemicals Corp; magnesium oxide (MgO) is obtainable from Marine Magnesium, Whittaker Clark and Dan, or Akrochem; zinc sulphide (ZnS) is obtained from Ore and Chemical Corporation ; Kraton is ethene-butene rubber impact modifier available from Shell Chemical Company; and HIPS is high impact polystyrene available from Huntsman Chemical. All amounts in the Table 1 are set forth in units of parts per hundred parts of the total composition.

The samples were compounded in a Werner & Pfleiderer co-rotating intermeshing twin-screw extruder. The extruder has a primary (upstream) melting and mixing section for melting resins and mixing with each other, and mixing filler(s) with the polymer melt, and a secondary (downstream) mixing section for distributive mixing of the added fibers. Thus, glass and/ or carbon fibers are added downstream. For the experiments described in this example, the extruder was operated at a temperature of 550 °F, and a speed of 350 rpm, to result in polymer production at a rate of 40 lb/hr. After compounding the samples were injection molded using a Van Dorn Demag 120 ton injection molding machine (melt temperature: 560 °F, mold temperature: 190 °F) to produce specimens for testing.

The following tables illustrate the concept described in this invention. The flame testing was conducted as per the UL94 Vertical Burn Protocol. The results in the tables are based on 20 bar burn-test in order to get statistically meaningful results. A UL94 Analysis tool described below was used to calculate the probability of passing UL94 V0 (vertical bar burn) pass criteria. Viscosities at various shear rates for these samples were measured using Kayeness capillary rheometer. The physical, thermal and mechanical tests were conducted as per the ASTM standards. The results in the tables are average of testing 5 samples (average of 3 samples for HDT) in order to get statistically meaningful data. 08CE05988

Table 1

Raw Material Description 10 11

0.40 IV PPE Resin 61.25 61.25 61.25 61.25 61.25 61.25 61.25 61.25 61.25 61.25 61.25

Arkon P-125 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5

LLDPE 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5

BPA-DPFR 15 15 15 15 15 15 15 15 15 15

OCF R22Y K-filament glass fibers 15 10 10 10 10 10 10 10 10 10 10

Clay, Huber 90G

Mica Suzorite 200HK

Talc Cimpact 610 C

Wollastonite Orleans 325

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Minco Min-Sil 20 5

US Silica (Minusil) _ 5

Barium Sulfate 5

Untreated nano-clay 5

Ti02 5

Glass Beads 5

Phosphite 168 Stabilizer 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

MgO 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

ZnS 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15

Total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00

Specific Gravity 1.224 1.225 1.228 1.225 1.221 1.224 1.226 1.237 1.224 1.238 1.227

UL94 Flame Test, 1/16"

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Average Flame-Out Time, first flame Sec 3.5 2 1.5 1.5 1.6 2 2.8 2.3 1.6 2 1.9 application

Standard Deviation of Flame-Out Time, first Sec 7.2 2.9 0.3 0.5 0.6 0.8 2.3 1 0.7 0.7 0.8 flame application

Average Flame-Out Time, second flame Sec 5.1 2 2.5 2.8 2 2.1 2.5 2.9 1.9 3.4 4.3 application

Standard Deviation of Flame-Out Time, Sec 7.9 1 1.8 2 0.7 1.1 1.4 2.4 1.3 1.8 3.8 second flame application

Average Flame-Out Time, Overall Sec 4.3 2 2 2.1 1.8 2.1 2.6 2.6 1.7 2.7 3.1

Standard Deviation of Flame-Out Time, Sec 7.5 2.2 1.4 1.6 0.7 0.9 1.9 1.8 1 1.6 3

Overall

Probability of passing UL94 VO rating on first 0.5096 0.9970 0.9857 0.9806 1.0000 0.9993 0.9676 0.9668 0.9987 0.9799 0.6835 submittal of 5 flame bars

Probability of passing UL94 VI rating on first 0.9786 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.9911 submittal of 5 flame bars

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Flex. Str. @ yield, 2" Spar i, 1/8", 0.05 psi 23670 20270 22290 21800 21760 20030 20843 21610 21207 21200 21530 in/min, ASTM D790

Flex. Mod 1/8", 0.05 in/min, ASTM D790 kpsi 802.2 742.5 766.9 768.4 719.6 707.9 698.1 705.8 701.4 689.6 714.9

Flex. Strain @ Max Load, ASTM D790 % 3.19 2.87 3.39 3.15 3.41 3.00 3.82 3.84 3.65 3.49 3.31

Viscosity, Pa-Sec, at 300 C at following shear rates

3000 S-ⁱ 76.1 75 75.6 75.1 72.6 ■ 75 72.4 74.3 77.1 73.2 77.3

2500 S-ⁱ 81.7 80.5 81.8 80.7 78.9 81.2 77.7 81 82.9 78.7 83.6

2000 S-¹ 91.5 89.2 88.5 89.9 87.7 90.9 86.2 89.6 90.8 88 93.1

1500 S-¹ 104.3 102.7 100 103.8 99.5 104.2 100.7 102.7 103.4 102.7 105.9

1000 s-ⁱ 127.3 126.1 123.1 125.9 123.1 126.1 119 125.6 125.6 118.8 127.7

700 S-¹ 154.3 149.4 142 150.2 144.7 150.2 141.9 146.6 150.3 141.5 150.2

500 S-¹ 180.7 173.7 163.2 175.4 167.4 169.2 165.2 168.3 171.4 163.9 174

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300 S-ⁱ 223.7 212.2 211.1 216.2 205.3 215.1 206.3 205.2 214.9 200.2 211.6

200 S-ⁱ 291.4 275.3 261 278 265.4 252.9 253.6 25.1.8 269.7 236 265.4

100 s-³ 386.1 353.9 341.4 373.6 330.7 336.1 344.7 314.3 344.7 312.8 346.8

50 S-¹ 543.4 450.5 432.6 493.4 461.2 436.2 439.3 396.4 475 382.5 425.4

25 S-ι 657.8 536.3 486.2 629.2 550.6 543.4 564.3 485.7 635.7 436.2 500.5

The compositions made as shown in Table 1 were tested for flammability using a flame retardance testing tool which provides a prediction of the likelihood that a particular UL standard, such as UL-94 will be passed. The UL-94 protocol calls for bar-shaped specimens of dimensions 5" (12.7 cm) x Vi (1.3 cm) width x the desired normal thickness, UL-94 ratings being specified for a particular thickness, A flame having an inner cone of height %" (1.9 cm) is applied to each specimen so that a distance of 3/8" (1.0 cm) separates the lower end of the specimen from base of the flame. The flame is held in that position for 10 seconds and then removed. A burn time is defined as the time required for the flame issuing from the specimen to disappear. If burning of the specimen ceases within 30 seconds, the flame is reapplied for an additional 10 seconds. The criteria for V-0, V-l, and V-2 ratings are listed in Table 2.

Table 2

Vertical Flame Class Requirements

(Individual NO NO YES specimen) Drip particles that ignite cotton

For a V-0 r ating, no individual burn times, from the first or second application may exceed 10 seconds. The total of the burn times for any five specimens may not exceed 50 seconds. Drip particles that ignite a piece of cotton gauze situated below the specimen are not allowed.

For a V-l rating, no individual burn times, from the first or second application may exceed 30 seconds. The total of the burn times for any five specimens may not exceed 250 seconds. Drip particles that ignite a piece of cotton gauze situated below the specimen are not allowed.

For a V-2 rating, no individual burn times, from the first or second application may exceed 30 seconds. The total of the burn times for any five specimens may not exceed 250 seconds. Drip particles that ignite a piece of cotton gauze situated below the specimen are allowed.

A statistical analysis of the data obtained from a flame test can be applied to determine the probability of at least one possible outcome of the test. Possible outcomes include a first submittal pass, including first time pass and retest, and a second submittal pass, including first time pass and retest, and failure. The probability of at least one outcome, preferably a first time pass on a first submission, provides a measure of the flame retardance of the polymer composition, while minimizing the variability inherent in flame testing, particularly the UL-94 test.

The raw data may be transformed prior to use in the statistical calculations by conversion to equivalent logarithmic values. ("Logarithm" and "logarithmic" refer to base 10 logarithms.) Times less than one second may be rounded up to one second in order to avoid negative logarithmic values. The logarithm of the burn time may then be calculated and used in subsequent steps. Use of transformed data is preferred as a more normal distribution of values associated with burn time is thereby provided. Raw data do not show a normal (bell-shaped) distribution curve because there can be no values less than zero, and data points are typically clustered in the space below the maximum individual burn time. The transformed data, however, more closely fit a normal distribution curve.

The probability of a first time pass may be determined according to the formula:

Pfirst time pass ⁼ (Ptl>mbt, n=0 X Pt2>mbt n=0 X

X Pdrip, n=θ)

where Ptι>mbt, n=o is the probability that no first burn time exceeds a maximum burn time value, Pt2>mbt, n=o is the probability that no second burn time exceeds a maximum burn time value, Ptotai<=m._>. is the probability that the sum of the burn times is less than or equal to a maximum total burn time value, and Pdrip, n=o is the probability that no specimen exhibits dripping during the flame test. First and second burn time refer to burn times after a first and second application of the flame, respectively.

The probability that no first burn time exceeds a maximum burn time value, Ptι>mbt,n=o, may be determined from the formula:

Ptl>mbt, n=0 = (1 -Ptl>mbt)⁵

where Ptι>_mbt is the area under the log normal distribution curve for tl>mbt.

and where the exponent "5" relates to the number of bars tested. The probability that a single second burn time exceeds a maximum burn time value may be determined from the formula:

where Pt2>mbt is the area under the normal distribution curve for t2>mbt. As above, the mean and standard deviation of the burn time data set are used to calculate the normal distribution curve. For the UL-94 V-0 rating, the maximum burn time is 10 seconds. For a V-1 or V-2 rating, the maximum burn time is 30 seconds.

The probability Pdri , n=o that no specimen exhibits dripping during the flame test is an attribute function, estimated by:

(1 - Pdrip)⁵

where the number of bars that drip / the number of bars tested.

The probability

that the sum of the burn times is less than or equal to a maximum total burn time value may be determined from a normal distribution curve of simulated 5-bar total burn times. The distribution may be generated from a Monte Carlo simulation of 1000 sets of five bars using the distribution for the burn time data determined above. Techniques for Monte Carlo simulation are well known in the art. A normal distribution curve for 5- bar total burn times may be generated using the mean and standard deviation of the simulated 1000 sets. Therefore, Ptotai<=mtbt may be determined from the area under a log normal distribution curve of a set of 1000 Monte Carlo simulated 5-bar total burn time for total <= maximum total burn time. For the UL-94 V-0 rating, the maximum total burn time is 50 seconds. For a V-1 or V- 2 rating, the maximum total burn time is 250 seconds. The probability of a retest is determined according to the following formula:

Pretest = (Ptl>mbt, n=l X Pt2>mbt, n=0 X Ptotal<=mtbt X Pdrip, n=θ) +

(Ptl>mbt, n=0 X Pt2>mbt, n=l X Ptotal<=mtbt X Pdrip, n=θ) +

(Ptl>mbt, n=0 X Pt2>mbt, n=0 X

X Pdrip, n=θ) +

(Pfl>mbt, n=0 X Pt2>mbt, n=0 X Ptotal<=mtbt X Pdrip, n=l)

where Ptι>mbt, n₌ι is the probability that a single first burn time exceeds a maximum burn time value, Pt2>mbt, n=ι is the probability that a single second burn time exceeds a maximum burn time value, Pm.b.<totai<=mrtbt is the probability that the sum of individual burn times is greater . than the maximum total burn time value and is less than or equal to the maximum retest total burn time value, Pdrip, n₌ι is the probability that a single specimen exhibits dripping during the flame test and Pti>mbt,

and Pdrip, n=o, are as defined above.

The probability that a single first burn time exceeds a maximum burn time value may be determined from the formula:

Ptl>mbt, n=l =5 X Ptl>mbt X (1 -Ptl>mbt)⁴

where Pti>mbt is defined as above.

The probability that a single second burn time exceeds a maximum burn time value may be determined from the formula:

Pt2>mbt, n=l =5 X Pt2>mbt X (1 -Pt2>mbt)⁴

where Pt2>mbt is defined above. The probability that the sum of individual burn times is greater than the maximum total burn time value and is less than or equal to the maximum retest total burn time value may be determined from the normal distribution curve of simulated 5-bar total times, as described above for Ptotai<=mtbt. Pmtbt<totai<₌mrtbt is equal to the area under a log normal distribution curve of a set of 1000 Monte Carlo simulated 5-bar total burn time for maximum total burn time < total <= the maximum retest total burn time value. For the UL-94 V-0 rating, the maximum total burn time is 50 seconds, and the maximum retest total burn time value is 55 seconds. For a V-1 or V-2 rating, the maximum total burn time is 250 seconds, and the maximum retest total burn time value is 255.

The probability that a single specimen exhibits dripping during the flame test may be estimated from the following attribute function:

1 drip, n=l ⁼ X 1 drip X (1 - 1 drip)

where Pdrip is defined as for a first time pass, above.

By definition, the sum of the probabilities of possible outcomes of a first submittal is one:

Σ(Prθbabilities) = P first time pass + P retest + P failure, no retest = 1.

Therefore, the probability of a failure is given by:

I failure, no retest ⁼ 1 - 1 first time pass " P retest

The probability of a first submittal pass is given by:

1 1st submittal pass ⁼ 1 first time pass ' 1 retest X 1 first time pass

where Pfet time pass and P retest are as defined above. The probability of a second submittal pass is determined according to:

1 2nd submittal pass ⁼ 1 failure, no retest X (1 first time pass ^"*^" 1 retest X I first time pass)

where Pfirst time pass , Pretest and P failure, no retest as defined above.

Finally, the probability of a pass after a first and second submittal, or the overall probability of a pass is:

I overall pass ⁼ 1 1st submittal pass ^"•^" I 2nd submittal pass

Using this procedure, each of the compositions of Table 1 were evaluated. Table 1 compares the effect of adding 5% mineral, titanium dioxide or glass beads on glass fiber reinforced PPE formulations. The total amount of fillers was kept constant at 15% in these experiments. Addition of clay, mica, talcum, wollastonite, silica, barium sulfate, untreated nano-clay and titanium dioxide resulted in enhancement of flame retardancy. Use of glass beads did not improve the flame retardancy to a significant extent.

Table 3 shows the effect of adding minerals at various different levels on flame retardancy of glass fiber reinforced PPE formulations. Again, the total filler level was kept constant at 15% in these experiments. Even presence of 2% mineral in these formulations resulted in robust UL94 VO performance. Moreover, increase in amount of mineral led to enhancement in flame retardancy. Again, use of glass beads instead of a mineral filler in the glass fiber PPE formulation did not improve flame retardancy. 08CE05988

Table 3

Raw Material Description 12 13 14 15 16 17 18

0.40 IV PPE Resin 61.25 61.25 61.25 61.25 61.25 61.25 61.25 61.25 61.25

Arkon P-125 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5

LLDPE 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5

BPA-DP FR 15 15 15 15 15 15 15 15 15

Clay, Huber 90G

Mica Suzorite 200HK

Ti02

Glass Beads 2 5

Phosphite 168 Stabilizer 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

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MgO 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

ZnS 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15

Total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00

Specific Gravity 1.224 1.226 1.225 1.229 1.228 1.228 1.238 1.228 1.227

UL94 Flame Test, 1/16"

Average Flame-Out Time, first flame Sec 3.5 2.1 2 1.9 1.5 1.6 2 1.8 1.9 application

Standard Deviation of Flame-Out Sec 7.2 1.7 2.9 1.1 0.3 0.5 0.7 0.8 0.8

Time, first flame application

Average Flame-Out Time, second Sec 5.1 2.6 2 3.4 2.5 3.1 3.4 3.9 4.3 flame application

Standard Deviation of Flame-Out Sec 7.9 1.6 1 3.9 1.8 2.1 1.8 4.7 3.8

Time, second flame application

Average Flame-Out Time, Overall Sec 4.3 2.4 2 2.6 2 2.4 2.7 2.8 3.1

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Standard Deviation of Flame-Out Sec 7.5 1.6 2.2 2.9 1.4 1.7 1.6 3.5 Time, Overall

Probability of passing UL94 VO rating on first 0.5096 0.9847 0.9970 0.8947 0.9857 0.8825 0.9799 0.7000 0.6835 submittal of 5 flame bars

Probability of passing UL94 VI rating on first 0.9786 1.0000 1.0000 0.9993 1.0000 0.9989 1.0000 0.9933 0.9911 submittal of 5 flame bars

CTE (-40 C to 100 C) in-flow direction mm/mm/C 2.94E-05 2.85E-05 2.82E-05 2.84E-05 3.32E-05 3.30E-05 3.59E-05 2.86E-05 3.23E-05

CTE (-40 C to 100 C) cross-flow mm/mm/C 5.77E-05 5.66E-05 5.70E-05 6.05E-05 5.72E-05 5.90E-05 5.67E-05 5.88E-05 6.00E-05 direction

Un Notch. Izod, 73 F, 1/8", 2 ft lb ft lb / in 7.254 5.867 4.167 6.631 5.839 4.978 4.68 6.371 5.489

Hammer, ASTM D256

Rev. Notch. Izod, 73 F, 1/8", 2 ft lb ft lb / in 4.154 4.225 2.954 4.236 3.786 3.714 2.661 4.716 4.077

Hammer, ASTM D256

Tens. Break Str. (0.2 in/min), ASTM psi 16183 15163 13952, 14835 14907 13449 13022 14773 13834

D 638

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D 638

Tens. Elong @ break, ASTM D 638 % 2.73 2.8 2.48 2.74 2.78 2.79 2.9 2.65 2.87

Flex. Str. @ yield, 2" Span, 1/8", 0.05 psi 23670 23030 20270 22900 22290 21510 21200 22850 21530 in/min, ASTM D790

Flex. Mod. 1/8", 0.05 in/min, ASTM kpsi 802.2 768.6 742.5 788.0 766.9 735.3 689.6 780.9 714.9

D790

Flex. Strain @ Max Load, ASTM D790 % 3.19 3.629 2.867 3.611 3.389 3.751 3.486 3.574 3.311

Viscosity, Pa-Sec, at 300 C at following shear rates

3000 S-ⁱ 76.1 76.6 75 73.9 75.6 79 73.2 76.6 77.3

2500 S-¹ 81.7 82.9 80.5 80.7 81.1 84.9 78.7 82.6 83.6

2000 S-ⁱ 91.5 92.4 89.2 90 ϊ.5 93.7 88 90.5 93.1

1500 S-ⁱ 104.3 106.6 102.7 101.3 100 107 102.7 102.8 105.9

1000 S-ⁱ 127.3 130 126.1 127 123.1 128.2 118.8 123.9 127.7

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700 S-i 154.3 155.9 149.4 146.3 142 149 141.5 152 150.2

500 S-i 180.7 178.1 173.7 173.9 163.2 176.3 163.9 172.5 174

300 S-¹ 223.7 228 212.2 214.9 211.1 212.6 200.2 220 211.6

200 S-¹ 291.4 278.6 275.3 263.4 261 253.6 236 259.8 265.4

100 S-¹ 386.1 392.9 353.9 355.4 341.4 326.8 312.8 358.9 346.8

50 S-¹ 543.4 521.5 450.5 435.7 432.6 432.2 382.5 485.7 425.4

25 S-¹ 657.8 678.6 536.3 500 486.2 578.6 436.2 592.9 500.5

Tables 4 and 5 show similar results when PPE formulations contain higher level of fillers/ reinforcements. Again, enhanced flame retardancy is obtained when part of the glass fibers in the formulations is replaced by a mineral.

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Specific Gravity 1.281 1.286 1.285

UL94 Flame Test, 1/16"

Average Flame-Out Time, first flame application Sec 3.5 2 1.9

Standard Deviation of Flame-Out Time, first flame application Sec 2.4 1 0.5

Average Flame-Out Time, second flame application Sec 5.2 3.4 3.6

Standard Deviation of Flame-Out Time, second flame application Sec 2.5 1.3 1.5

Average Flame-Out Time, Overall Sec 4.3 2.7 2.8

Standard Deviation of Flame-Out Time, Overall Sec 2.6 1.3 1.4

Probability of passing UL94 VO rating on first submittal of 5 flame bars 0.4684 0.9918 0.9580

Probability of passing UL94 VI rating on first submittal of 5 flame bars 0.9972 1.0000 1.0000

CTE (-40 C to 100 C) in-flow direction mm/mm/C 2.24E-05

CTE (-40 C to 100 C) cross-flow direction mm/mm/C 6.42E-05

HDT @ 264 psi 1/8", ASTM D648 F 210.1 208.6 206.7

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Specific Gravity

UL94 Flame Test, 1/16"

Average Flame-Out Time, first flame application Sec 1.9 1.6

Standard Deviation of Flame-Out Time, first flame application Sec 1.6 0.8

Average Flame-Out Time, second flame application Sec 6.6 3.4

Standard Deviation of Flame-Out Time, second flame application Sec 5.2 2.4

4-

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Average Flame-Out Time, Overall Sec 4.2 2.5

Standard Deviation of Flame-Out Time, Overall Sec 4.5 2

Probability of passing UL94 VO rating on first submittal of 5 flame 0.3005 0.8661 bars

Probability of passing UL94 VI rating on first submittal of 5 flame 0.9619 0.9990 bars

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CTE (-40 C to 100 C) in-flow direction mm/mm /c

CTE (-40 C to 100 C) cross-flow direction mm/mm /c

HDT @ 264 psi, 1/8", ASTM D648 F 239.1 239.7

Notch. Izod @ 73 F, 1/8", 2 ft lb Hammer, ASTM D256 ft lb / in 1.17 0.97

Un Notch. Izod, 73 F, 1/8", 2 ft lb Hammer, ASTM D256 ft lb / in 7.49 6.67

Rev. Notch. Izod, 73 F, 1/8", 2 ft lb Hammer, ASTM D256 ft lb / in 4.37 3.99

Total Energy, Dynatup Impact, 4" D X 1/8", 23 C, 7.5 MPH ft lb 7.03 6.20

Tens. Break Str. (0.2 in/min), ASTM D 638 psi 15290 14850

Tens. Elong @ break, ASTM D 638 % 4.75 4.92

Flex. Str. @ yield, 2" Span, 1/8", 0.05 in/min, ASTM D790 psi 18930 19090

Flex. Mod. 1/8", 0.05 in/min, ASTM D790 kpsi 1007 991.7

Table 6 show that the synergistic effect of mineral on flame retardancy is also observed in carbon fiber reinforced PPE formulations. The carbon fiber used in this example was supplied by Fortafil Fibers Inc.

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Total 100.00 100.00 100.00

Specific Gravity 1.264 1.255 1.256

UL94 Flame Test, 1/16"

Average Flame-Out Time, first flame application Sec 2 1.6 1.5

Standard Deviation of Flame-Out Time, first flame application Sec 1.5 0.4 0.4

Average Flame-Out Time, second flame application Sec 10.2 6.9 5.7

Standard Deviation of Flame-Out Time, second flame application Sec 7.9 8.2 3.4

Average Flame-Out Time, Overall Sec 6.1 4.2 3.6

Standard Deviation of Flame-Out Time, Overall Sec 7 6.3 3.2

Probability of passing UL94 VO rating on first submittal of 5 0.0338 0.2939 0.5309 flame bars

Probability of passing UL94 VI rating on first submittal of 5 0.7466 0.9397 0.9958 flame bars

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Claims

WHAT IS CLAIMED IS:

1. A composition comprising:

(a) a polymer component comprising a polyphenylene ether;

(b) glass or carbon reinforcing fibers in an amount sufficient to increase the modulus and strength of the composition;

(c) a fire retardant component;

(d) a mineral component in an amount effective to enhance the flame-retardant characteristics of the composition.

2. The composition of claim 1, wherein the fire retardant component is an organophosphate.

3. The composition of claim 2, wherein the mineral component is a silica.

4. The composition according to claim 3, wherein the mineral component is present in an amount from about 0.5 to about 30 % by weight of the composition.

5. The composition of claim 2, wherein the mineral component is mica.

6. The composition according to claim 5, wherein the mineral component is present in an amount from about 0.5 to about 30 % by weight of the composition.

7. The composition of claim 2, wherein the composition comprises

1 to 30% by weight of glass fibers and 5 to 30% by weight of the organophosphorus fire retardant.

8. The composition of claim 2, wherein the organophosphorus fire retardant is resorcinol diphosphate or bisphenol-A diphosphate.

9. The composition of claim 8, wherein the mineral component is clay.

10. The composition of claim 9, wherein the mineral component is present in an amount from about 0.5 to about 30 % by weight of the composition.

11. The composition of claim 10, wherein the composition comprises 1 to 30% by weight of glass fibers and 5 to 30% by weight of the organophosphorus fire retardant.

12. An injection-molded article formed from a glass or carbon fiber- reinforced polyphenylene ether composition, wherein the glass or carbon fiber-reinforced polyphenylene ether composition comprises:

(a) a polymer component comprising a polyphenylene ether;

(b) glass or carbon reinforcing fibers in an amount sufficient to increase the modulus and strength of the polyphenylene ether composition;

(c) a fire retardant component; and

13. The article of claim 12, wherein the fire retardant component is an organophosphate.

14. The article of claim 13, wherein the mineral component is a silica. 02/18485

15. The article of claim 13, wherein the mineral component is present in an amount from about 0.5 to about 30 % by weight of the composition.

16. The article of claim 13, wherein the mineral component is clay.

17. The article of claim 16, wherein the miner component is present in an amount from about 0.5 to about 30 % by weight of the composition.

18. The article of claim 17, wherein the composition comprises 5 to 50% by weight of glass fibers and 5 to 30% by weight of the organophosphorus fire retardant.

19. A method for making a glass or carbon fiber-reinforced polyphenylene ether composition, comprising the steps of:

preparing a mixture by combining the following ingredients:

(a) a polymer component comprising a polyphenylene ether;

(c) a fire retardant component; and

d) a mineral component in an amount effective to enhance the flame-retardant characteristics of the composition.

compounding the mixture to blend the ingredients into a uniform composition.

20. The method of claim 19, wherein the fire retardant component comprises an organophosphate fire retardant.

21. The method of claim 20, wherein the mineral component is clay.

22. The method of claim 22, wherein the mineral component is present in an amount from about 1 to about 5 percent by weight of the composition.