MXPA98007098A - Compositions of polycarbonate molding - Google Patents

Abstract

The performance of molded articles of polycarbonate resin in the UL-94 test of Underwriters Laboratary for drip inhibition is improved by selecting the particle sizes of the fluorinated polyolefin and styrene-acrylonitrile components in resin blends prepared for molding of article

Description

COMPOSITIONS OF POLYCARBONATE MOLDING FIELD pg UM E CT N The invention relates to thermal optic mixtures of aromatic polymers of carbonate and copolymer of styrene and acrylonitrile.

* BRIEF DESCRIPTION OF THE RELATED ART I The aromatic carbonate polymers »such as the poly carbonates» have become very important commercial thermoplastics. in view of its excellent properties -physical In addition, sometimes the physical properties can be improved by mixing them with other thermoplastics. • frequently the choice of the type of additive thermoplastic and the quantity are critical. For example, mixtures of polycarbonates with copolymers of styrene-acrylonitrile (SAN) have significantly improved flow properties for molding purposes, see for example the description in EU Patent No. 5,106,907. . The polytetrafluoroethylene (PTFE) resin is also an additive for the carbonate molding composition, particularly if the composition is to be used by molding articles such as instrument housings that require # retardation of "fire spread" and "drip delay" see for example US Patents No. 3 »294» B71 and 5 »102,696. Normally, poly terephoro-ethylene (PTFE) is added to the polycarbonate molding mixes to prevent molded articles from leaking when a fire starts. Certain applications demand a specific classification of the UL-94 test from Underwriters Laboratory »as V-O at 1.00 mm. This requirement is needed »for example» in electrical applications »as in boxes and switches. If the materials leak in the UL-94 test, they can not be used in these applications. The patent application of E. U. Series No. 08 / ß06 »027» filed on ß October 1995 »describes a mixture of polymers in which groups of derivatives of Tetrafluoroethylene are encapsulated by a polymer or a copolymer. It has been found that these mixtures are very useful # as additives to increase the fire resistance of polymer compositions. The authors of this have now found that The tight control of the particle size of these encapsulated PTFE particles is key to obtaining the desired performance in UL-94 in polycarbonate articles. The size of the particles has an important influence on the behavior of PTFE in the flame. 25 The effect of anti-drip agent is not only determined by the control of the PTFE particle size.

W ?. It is also required to control the average diameter of the agglomerates of the encapsulated particles. The normal shear stress that occurs during the usual treatment steps usually used, stretches the polymer chains to give the desired anti-drip performance. The control of particle size and agglomerate makes it possible to manufacture products that meet the desired anti-drip properties when produced in conventional equipment. IO Without being limited to a theory of operation, the present authors consider that during the extrusion the encapsulated PTFE agglomerates are broken and the PTFE particles are stretched so that thermomically unfavorable situations occur for the PTFE molecule.

During combustion, the material relaxes »forming the optimum conformation» and retracts from the flame. The approach F manages by controlling the particle size and the agglomerate »in such a way that the shear stresses in the extruder are able to affect the structure of the molecule. If the particles are too small »the forces in the e? Trusor are not able to extend the chain. When the size of the agglomerates and the particles are within the limits, the molecules are stretched and the PTFE reacts as described above at the beginning of a trial.

BRIEF pgSC S g? Q PE THE INVECIÓ The invention comprises a thermoplastic molding composition »comprising: A thermoplastic aromatic polycarbonate resin» A drip-inhibiting ratio of particles of a fluorinated polyolefin resin partially or wholly encapsulated by a thermoplastic copolymer to form agglomerates said fluorinated polyolefin resin has average particle diameters on the scale of about Ol to 4 μm, and said agglomerates have average diameters of 30 to 70 μm »preferably of 35 to 65 μm» and preferably of 40 to 65 μm. The molding compositions of the invention are useful for molding articles with improved performance in the UL-94 drip test.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES OF THE INVENTION The aromatic polycarbonate polymers »useful in the compositions of the present invention» include polycarbonates and also copol ester-carbonates. The polycarbonates and the copolyeti-carbonates are well-known commercially available resins. Methods for preparing polycarbonates by interfacial polymerization »see» for example »the details provided in the patents of E. U. 3» 028.365 »3» 334.154 »3.275» 601i 3.915 »926i 3.030» 33i; 3,169,121; 3,027,814; and 4.18B.314"all of which are incorporated herein by reference. It is also known the preparation of polycarbonate by the process of melting »with an existing plant in Japan and another under construction in Spain. In general, the interfacial polymerization method * comprises the reaction of a dihydric phenol with a halide IO carbonyl (the carbonate precursor). The molten mixture polymerization method comprises the reaction of a dihydric phenol with a diaryl carbonate. Although the reaction conditions of the preparative procedure may vary, several of the procedures Preferred interfacials typically include dissolving or dispersing the diphenol reagents in an aqueous caustic, # add the resulting mixture to a solvent medium immiscible with suitable water »and contact the reagents with the carbonate precursor» such as phosgene, in the presence of a suitable catalyst and under controlled pH conditions. The most commonly used water-immiscible solids »include methylene chloride» 1,2-d chloro-ethane, chlorobenzene. toluene »and similar. The catalyst used accelerates the speed of the polymerization of the dihydric phenol reagent with the carbonate precursor. Representative catalysts include »but m are not limited to tertiary amines such as triet sheet »quaternary phosphonium compounds» quaternary ammonium compounds »and the like. The preferred process for preparing polycarbonate resins comprises a phosgenation reaction. The temperature at which the phosgenation reaction proceeds may vary from less than 0 ° C to more than 100 ° C. The phosgenation reaction preferably proceeds at temperatures from room temperature (25 ° C> to 50 ° C. < * the reaction is exothermic »the rate of addition of phosgene can be used to control the reaction temperature. The amount of phosgene required will generally depend on the amount of the dihydric phenols. The dihydric phenols used are known, and the reactive groups are the two phenolic hydroxyl groups. 15 Some of the dihydric phenols are represented by the general formula: # wherein A is a divalent hydrocarbon radical containing from 1 to about 15 carbon atoms; a substituted divalent hydrocarbon radical containing 1 to Approximately 15 carbon atoms and substituent groups such as halogen; -S-; -SS- »-S (0) w-» -0-; or -c-; # each X is independently selected from the group consisting of hydrogen »halogen» and a monovalent hydrocarbon radical such as an alkyl group of 1 to about 8 carbon atoms, an aryl group of 6-18 carbon atoms »an aralkyl group of 7 to about 14 carbon atoms »a group alloy" from 7 to about 14 carbon atoms "an alkoxy group of 1 to 8 carbon atoms, or an aryloxy group of 6 to 18 carbon atoms, and m is zero or 1 yn is an integer of O • a 4. 10 Typical of some of the dihydric phenols employed are bis-phenols such as bis (4-hydro? I-phenyl) methane »2,2-bis (4-hydroxyphenyl) propane (also known as bisphenol A) , 2,2-bis (4-hydroxy-3'-5-dibromophenyl) propane; dihydric phenol ethers such as bis (4-hydroxy enyl) -ether » bis (3 * 5-dichloro-4-hydroxyphenyl) -ether; dihydroxydiphenols such as p »p * -dihydroxyphenyl» 3 »3 * -dichloro-4-4f-d? h? dro? phenol» dihydroxylation Isulfones such as bis (4-hydroxyphenyl) sulfone. bis (3 »5-dimethyl-4-hydroxyphenyl) sulfone» dihydroxybenzenes such as resorcinol »hydroquinone, substituted dihydroxybenzenes with halogen and alkyl such as 1,4-dihydroxy-2,5-dichlorobenzene »1» 4-d hydroxy-3-methyl-1-benzene »and dihydroxydifeni sulphides and sulfoxides such as bis (4-hydroxyphenyl) sulphide» sulfoxide bis (4-hydroxyphenyl) and bis (3,5-dibromo-4-hydroxyphenyl) sulfoxide. There is available a variety of other dihydric phenols. and are described in U.S. Patent Nos. 2,999,835; 3 »028» 365 and 3 »153» 008 » all of which are incorporated herein by reference. Of course, it is possible to use two or more different dihydric phenols or a combination of a dihydric phenol with glycol. The carbonate precursor can be a carbonyl halide »a diarylcarbonate or a bishaloformate. Carbon halides include carbon bromide and carbonyl chloride and mixtures thereof. Bishaloformates include the bishaloformates of dihydric phenols such as < k bischloroformates of 2.2-bis (4- idroxifeni 1) propane »2.2-bis (4- IO hydroxy-3,5-dichloropheni 1) propane. hydroquinone and the like, or bishaloformates of gl cabals such as ethylene glycol bihaldehoformates. and similar. Although all of the above carbonate precursors are useful, carbonyl chloride is preferred for the interfacial process. known also as phosgene. Diphenylcarbonate is preferred for the melt mixing process. They are also included in the scope of the present invention. the randomly branched, high molecular weight thermoplastic poly carbonates. These polycarbonates Randomly branched are prepared by reacting together a polyfunctional organic compound with the aforementioned d hydrocarbon phenols and carbonate precursor. The polyfunctional organic compounds »useful in the production of the branched polycarbonates are indicated in Patents of U.S. Nos. 3,635,895 and 4,001,184, which are incorporated herein by reference. These compounds polyfunctional are generally aromatic and contain at least three functional groups that are carboxyl, carbohydric anhydrides, phenols, haloformyls or mixtures thereof. Some non-limiting examples of these functional pol aromatic compounds include, but are not limited to, tri-(4-hydrox phenyl) ethane, trimellitic anhydride, trimellitic acid, trichloro trichloride, 4-chloroform, 1-phthalic anhydride, pyromellitic, pyromellitic dianhydride »mellitic acid» mellitic anhydride »trimesic acid» benzophenonatetracarboxylic acid »benzophenone tetracarboxylic anhydride» and the like. Preferred polyfunctional aromatic compounds are lithium tri (4-hydroxyphenyl) ethane trichloric anhydride or trimellitic acid or their haloformyl derivatives. Mixtures of a linear polycarbonate and a branched polycarbonate are also included herein. The polycarbonate resin used in the process of the invention can be of a relatively low molecular weight (MW) or a relatively high molecular weight. Resins with lower P are generally blocked end carbonates. The so-called "blocked ends" polycarbonates are prepared by the methods described above to produce aromatic carbonate polymers "in which the reaction mixture includes small amounts of molecular weight regulators or chain terminators to provide end groups, or terminals on the polymer of IO carbonate and thereby control the molecular weight of the polycarbonate. A molecular weight regulator, ie a chain stop agent, is generally added to the reagents before or during contact with the carbonate precursor. Useful molecular weight regulators include but are not limited to monohydric phenols such as phenol, chroman-I, para-te-butylphenol, and the like. A component of The preferred polycarbonate of the compositions of the invention is IO one blocked at its ends with p-cumi Ifenol. Other compounds which can act as chain terminators for the carbonate polymers are also known. A) Yes. U.S. Patent 3,085,992 describes alkanolamines as chain terminators; U.S. Patent No. 3,399,172 teaches imides as chain terminators; US Patent No. 3,275,601 discloses that aniline and methylene are chain terminators in the interfacial polymerization process to produce polycarbonates; and U.S. Patent No. 4,011,184 disclose primary amines and secondary ones as molecular weight regulators for pol carbonate. Furthermore, U.S. Patent No. 3,028,365 discloses that aromatic amines and other monofunctional compounds can be used to control or regulate the molecular weight of polycarbonates »thereby forming terminal groups ari Icarbamate. In U.S. Patent No. 4,111,910 describes aromatic polycarbonates having carbamate groups of e? tremo. These polycarbonates are prepared using a terminating amount of ammonia, ammonium compounds, cycloalkylamines. aliphatic amines or aralqui primary plates, and cycloalkylamines, alkylamines or aralqui secondary plates. Aromatic carbonate polymers suitable for use in the compositions of the invention include polyester-carbonates, also known as copolyester-polycarbonates. this is »resins containing» in addition to the recurring polycarbonate chain units of the formula: (Ha) wherein D is a divalent aromatic radical of the dihydric phenol used in the polymerization reaction, repeating or recurring carboxylate units "eg of the formula: -C-0-C (0) -RJ ~ C (0) -0-D-3- (Hb) where D is as defined above and A is as defined below. Copper-ester polycarbonate resins are also they prepare by interfacial polymerization techniques »well known to the person skilled in the art» see »for example» the Patents of US Pat. No. 3 »169,121 and 4,487,896. In general, copolyester / polycarbonate resins are prepared as described above for the preparation of polycarbonate homopolymers. but also with the presence of a dicarboxylic acid (ester precursor) in the solvent immiscible in water. ^^^ In general, any acid can be used IO dicarboxylic acid conventionally used in the preparation of linear polyesters, in the preparation of copolyester-carbonate resins. Generally, the dicarboxylic acids that can be used include aliphatic dicarboxylic acids, aromatic dicarboxylic acids and acids. dicarboxylic cos to the aromatic-isatic. These acids are well known and are described, for example, in U.S. Patent No. 3,169,121, which is incorporated herein by reference. Representative of these aromatic dicarboxylic acids are those represented by the general formula: 2? H00C-R * -C00H (III) wherein R represents an aromatic radical such as phenylene »naphthalene» biphenylene »substituted phenylene and the like» a hydrocarbon radical divalent to the phtharomatic such as an aralkyl radical or alkarylo; or two or more aromatic groups bound by non-aromatic linkages of the formula: - E - wherein E is a divalent alkylene or alkylidene group. E may also consist of two or more alkylene or alkylidene groups bonded to a non-alkylene or alkylidene group, for example an aromatic link, a tertiary amino link, an ether link, a carbonyl bond, a link IO containing silicon »or by a sulfur-containing bond such as sulfide» sulfoxide »sulfone and the like. Furthermore, E may be a cycloaliphatic group of five to seven carbon atoms, inclusive, (eg, "cyclopentyl" cyclohexyl), or a cycloalkyl 1 of five to seven carbon atoms "inclusive" such as cyclohexyl idene. E may also be a bond containing sulfur »carbon l» such as sulfur »sulfoxide or sulfone; an ether link; a carbonyl group; a direct link; a group of tertiary nitrogen; or a linkage containing silicon such as silane or siloxy. The expert in matter can conceive other groups that E can represent. For the purposes of the present invention, aromatic dicarboxylic acids are preferred. Thus, in the preferred aromatic difunctional carboxylic acids of the formula (III), R x is an aromatic radical such as phenylene, biphenylene »naphthylene, or substituted phenylene. Some non-limiting examples of aromatic dicarboxylic acids that can used in the preparation of the poly (ester carbonate) or polyarylate resins of the present invention, include phthalic acid, isophthalic acid, terephthalic acid, homophthalic acid, o-, m- and p-phenylenediacetic acid, and the acids polynuclear aromatics such as diphenyldicarboxylic acid and isomeric naphthalenedicarboxylic acids. The attic rings may be substituted with Y groups. And may be an inorganic atom such as chlorine, bromine, fluorine and the like; an organic group such as the nitro group; an organic group such as alkyl; or an oxy group such as alkoxy, it being only necessary that Y be inert to and not be affected by the reactants and the reaction conditions. Particularly useful aromatic dicarboxylic acids are those represented by the general formula: (IV) in which j is a positive integer that has a value of 0 to 4 »inclusive; and each Ra is selected from the group consisting of alkyl radicals, preferably lower alkyl (1 to about 6 carbon atoms). Mixtures of these acids can be used dicarboxi 1 icos. Therefore »in the case where the term" dicarboxylic acid "is used, it is understood that this term includes mixtures of two or more carboxylic acids. The most preferred aromatic dicarboxylic acids are isophthalic acid »terephthalic acid» and mixtures thereof. A particularly useful difunctional carboxylic acid comprises a mixture of isophthalic acid and terephthalic acid wherein the weight ratio of terephthalic acid to acid ^? isophthalic is on the scale of about 10: 1 to IO approximately 0.2: 9.8. Instead of using the dicarboxylic acid per se, it is possible and sometimes it is even preferred to use the reactive derivatives of said acid. Illustrative of these reactive derivatives are the acid halides. The Preferred acid halides are acid dichlorides and acid dibromides. Thus, for example, instead of using isophthalic acid, terephthalic acid or mixtures thereof, it is possible to use isophthaloyl dichloride, terephthalate dichloride and mixtures thereof. The proportions of the reagents used to prepare the copolyester-carbonate resins vary according to the proposed use of the mixtures of the invention containing this product resin. Those skilled in the art are aware of the useful proportions "as described in U. U. patents referred to above. In general »the amount of ester bonds can be approximately 5 to approximately 90 mole percent »in relation to carbonate bonds. For example »5 moles of bisphenol A reacted completely with 4 moles of isophthaloyl dichloride and 1 mole of phosgene would give a copolyester-carbonate of 80 moleß percent of ester linkage. Preferred polycarbonates for use in the present invention are the bisphenol A and phosgene derivatives and have an intrinsic viscosity of about 0.3 to about 1.5 deciliters per gram "measured in methylene chloride at a temperature of 25 ° C" and a porosity within the range of 0.O0 to 2.O ml / g. The fluorinated polyolefins which are used in the present invention as well as the methods for their preparation are described among other documents »in Bill W. Fred W., Jr. Textbook of Polymer Science» Interscience Publishers »New York» NY »1966» p. 425-427; Moner Bear J. C. »Rubber Chem. Tech.» 34, 1521 (1961); and Rudner M.A., Fluorocarbons, Reinhold Publishing Corp. New York, N.Y., and U.S. Patent No. 4,663,991"which are incorporated herein by reference. The preferred fluorinated polyolefin is the polytetrafluoroethylene (PTFE) resin used in the process and compositions of this invention, preferably in a filar form. PTFE is a finely divided powder or fluff as obtained from the polymerization reaction. When a mass of this untreated polytetrafluoroethylene resin, finely divided »from average particle size from Ol to 0.2 microns» as illustrated in figures 1 and 2 of the article Tetrafluoroethane Resin Dispersion "Teflon" from JF Lontz and WB Happoldt Jr. in Ind. and Eng. Chem vol. 44 »p. 1800. 1952. It is subjected to shear stress by rubbing it on the hands »the particles tend to stick together and form a coherent mass. If this mass is extended and examined with a 50-100 X microscope, it shows fibers of various sizes. The examination with an electron microscope shows that these fibers IO are tied with smaller fibers, many of which consist of strings of the primary particles held together by very fine fibers having diameters from one quarter to one tenth or less of the diameter of the particles. In the practice of this invention »it is preferred to use polytetrafluoroethylene having the ability to cause the particles to adhere and spread to ultrafine fibrils when rubbed together with mechanical shear. The effective amount of fluoropoly for the The drip inhibition which is incorporated in the polyalkali resin by the process of the invention may be within the range of from about 0.01 to about 5 parts by weight per 100 parts of the polatonate, preferably from about 0.015. to approximately 3 parts "preferably from about 0.02 to about 2 parts" and most preferably from approximately 0.02 to approximately 1 part.

* The fluoropolymer is preferably used as an aqueous dispersion thereof, the particles having a preferred average size (diameter) of 0.05 to 4 microns, preferably 0.08 microns to 2 microns, and most preferably 0.1. to 1 miera. The fluoropolymer particles are conveniently encapsulated with the copolymer to form the ^ _ agglomerates, by means of spray drying of the aqueous dispersion ™ of the fluoropolymer mixed with the aqueous dispersion of the ÍO. thermoplastic copolymer. In accordance with the process of the invention, the two components, ie, the carbonate resin and the encapsulated fluoropolymer particle agglomerates, are mixed with each other at ambient temperatures and at high speeds. prescribed »using conventional mixing equipment» such as the prior art apparatus described above. In general, the combinations of the components can be mixed in conventional mixer rollers, pasta mixers, Banbury mixers and the like. The known devices and Representative implements for coating particulate materials with a homogeneous liquid are described in U.S. Patent 3,716,020 (De Wit et al.) Issued February 18, 1973, incorporated herein by reference. The styrene-acrylonitrile copolymer (SAN), which is the preferred polymer for encapsulating the PTFE particles of any of the well-known copolymers usable for this purpose can be prepared by copolymerization from about 6B54 to about 80% (preferably from about 70% to about 7854) of styrene and from about 20% to about 32% (preferably from about 22% to about 30%) of Acrylonitrile The molecular weight of SAN can be varied within a broad scale »typically from about 30,000 to about SOO» OOO »but this is not critical. # • »SAN is easily produced by procedures Known such as bulk polymerization »solution» suspension or emulsion. In the broader aspect of the invention, the encapsulated PTFE particle agglomerate encapsulating copolymer component can be present in a proportion of about 40 to about 50% by weight of the agglomerates; At this level, it provides good processing properties, notably in the case of shear stress of the PTFE particles. It is preferred that the copolymer component be present in a proportion of approximately 45 to about 49% by weight »and most preferably no more than 49% by weight. The (average) particle sizes of the SAN particles are conveniently within the range of 35 to 70 μm »and preferably within the range of 40 to 65 μm. The mixtures of the invention can be modified by the addition of additives known in the art of ? combination of plastics. These additives may include fillers (such as clay or talcum), reinforcing agents (such as glass fibers), impact modifiers, other resins, plasticizers, flow promoters and other processing aids, stabilizers, colorants, release agents. of mold »flame retardants» ultraviolet light protection agents »and the like. The production of the compositions of the invention can be carried out by mixing the components using any of the known mixing means for the thermoplastic mixture such as mixing in a kneading machine (such as a Banbury mixer or Werner Pfleiderer mixer) or in an extruder. , or by means of a roller mill), all of which provide the appropriate shear to achieve the desired fire retardant properties of the composition. The mixed composition of the invention can be eroded and cut, if desired, into granules and the like by means of standard techniques. The subsequent processing of the mixed compositions can be carried out by means of conventional molding or extrusion processes, well known in the art. The invention will be better understood with reference to the following examples "which are presented for purposes of illustration and not of limitation" and which indicate the best mode contemplated to carry out the invention. Where is reported »the UL-94 test of Underwiters? Laboratory Test is as follows: The resin is injection molded at approximately 300 ° C in test rods of approximately 12.7 cm by 1.27 cm by 3.175 cm in thickness. These bars are subjected to the test procedure outlined in Bulletin UL-94 of Underwriters »Laboratories» Inc. »Burning Test for Classified Materials C" Combustion Test for Classified Materials "]. According to this test procedure »the materials that pass are classified as V-0» V-I or V-II based on the results of 5 copies. The criteria for each classification V (for vertical) by UL-94 is »briefly» as follows: "V-0": The average flammability and / or glow after removing the ignition flame should not exceed 10 seconds and none of the 5 specimens should drip particles with flame that ignite absorbent cotton. The total flammability / incandescence time after turning on the 5 specimens should not exceed 50 seconds.

EyjE P QS 1-S Molding compositions were made by mixing the ingredients shown in the following table in an extruder Lector ZSK 36 at 270-300 ° C and 300 rpm. The mixed and extruded material was pelleted after it was dried and molded by injection at approximately 240 ° C to prepare specimens of proof. The physical properties were measured in injection molded samples "using the UL-94 test method of Underwriters' Laboratory at l.O mm. Example 1 is not of the invention but is presented for comparison purposes. The formulations and results are given in the following table. The polycarbonate resin was a blend of Lexan polycarbonate resin "grade 920 (General Electric Co. Pittsfield» Massachusetts) (examples 1 and 2) or polycarbonate resin Lexan ** grade 940 (examples 3-6).

IO copolymer used to form the PTFE particle agglomerates was styrene-acryltrine (SAN). These agglomerates were prepared by standard methods using PTFE as the sources identified in the table, to give the agglomerates of the average size and weight ratio of PTFE / SAN indicated in the table. All U.S. Patents and Patent applications identified herein are expressly incorporated by reference.

PICTURE Latex source Average size Paste PTFE »and agglomerate size PROTEUL-94 of particle X (μm) tion 1.0 mm P" SAN PM / N, M PTFE / SAN (Yes / No) 1. Hoechst: 10 Not controlled 24 330,000 2.77 50.4 / 49.5 No ICi: 0.2μ Fluon GDI 64 137,000 2.51 51.7 / 48.3 Yes 3. ICIP: 0.2μ Fluon GDI 42 332,000 2.61 52.6 / 47.4 Yes Í5 4. Hoechst: O.l μ 41 359,000 1.99 54.7 / 45.3 S 5. Ausimont: 0.24 μ 40 326,000 2.61 51.2 / 48.8 Yes 6. Dupont: 20 0.3μ 45 341,000 3.36 52.8 / 47.2 S

Claims (8)

Nqv? PAP OF THE INVENTION CLAIMS

1. - A thermoplastic molding composition comprising: an aromatic polycarbonate thermoplastic resin; a dripping inhibiting ratio of fluoropolymer resin particles at least partially encapsulated by a thermoplastic copolymer in agglomerates; said fluorinated polyolefin resin particles have average particle diameters within the range of about 0.1 to 4 μ; and said agglomerates have an average diameter of 30 to 70 μm. 2.- The composition in accordance with the rei indication 1 »characterized in that the fluoropolymer is fluorinated poly flour. 3. The composition according to claim 2 »characterized in that the fluorinated polyethylene is poly-tetrafluoroethylene. 4. The composition according to claim 1, characterized in that the fluoropolymer is in the amount of about 0.10 to about 5 parts by weight for each 100 parts by weight of the carbonate. 5. The composition according to claim 1, characterized in that the thermoplastic copolymer is styrene and acrylic copolymer. 1onitri lo. 6.- The composition in accordance with the claim 1 is characterized in that the thermoplastic copolymer is from about 40 to about 50% by weight of the agglomerate. 7. The composition according to the rei indication 1 »characterized in that the pol carbonate is prepared by an interfacial procedure. 8. The composition according to claim 1 »characterized in that the polycarbonate is «Prepared by a melt mixing process. F ZG RESUME ^ g W NVE CIÓ The performance of molded articles of polycarbonate resin in the UL-94 test of Underwriters Laboratory for drip inhibition is improved by selecting the particle size of the components of fluorinated pol-olefin and styrene-acrylonitrile in the resin mixtures prepared for molding articles. * EA / lss P98 / 430