JP5419916B2 - Thermally conductive polycarbonate resin composition and molded body - Google Patents

Description

  The present invention relates to a polycarbonate resin composition having excellent thermal conductivity and moldability, and less warping of a molded product, and a molded body thereof.

  Polycarbonate resins have balanced properties such as excellent impact resistance, heat resistance, and dimensional stability, such as electrical / electronic field, precision machine field, automobile field, security / medical field, food / miscellaneous field, etc. It is used for a wide range of applications. In particular, demand is growing in the OA field, electrical / electronic field, precision machine field, and automobile field.

  In these fields, most devices are equipped with components that generate heat, but in recent years, power consumption has increased along with higher performance of devices and components, and the amount of heat generated from components tends to increase. There is a concern that local high temperatures may cause troubles such as malfunctions. At present, the heat generated by using metal materials is diffused in the chassis, chassis, heat sink, etc., but the demand for replacement of these metal parts has increased by increasing the thermal conductivity of inexpensive resin materials. ing.

  As a method for imparting thermal conductivity to a resin material, many methods for mixing various thermal conductive fillers with a resin component have been reported. For example, Patent Document 1 discloses a thermoplastic resin having excellent thermal conductivity in which both high thermal conductivity inorganic fibers and high thermal conductivity inorganic powders are filled. However, in Patent Document 1, there is no example in which a polycarbonate resin is actually used as a thermoplastic resin, and vapor grown carbon fiber whiskers are used as highly thermally conductive inorganic fibers, but the fiber diameter is small. Since the aspect ratio is large, uniform dispersion in the resin is difficult, and sufficient thermal conductivity cannot be obtained due to fiber breakage during dispersion. In Patent Document 1, fluidity, warpage and dimensional stability of an injection molded product are not evaluated at all.

  Patent Document 2 describes a thermally conductive polymer material containing graphitized carbon fiber having a fiber diameter of 5 to 20 μm and an average particle diameter of 10 to 500 μm. However, in Patent Document 2, the main purpose is to increase the filling amount in the resin in order to obtain high thermal conductivity, and the types of polymer materials include silicone rubber, epoxy resin, thermoplastic elastomer, Polyacetal is only used as a thermoplastic resin, all of which are unsuitable for use as a housing for OA, electrical / electronic parts, precision equipment, etc., in terms of strength and appearance. There is no intention to improve moldability, warpage of injection-molded products, and dimensional stability.

  Furthermore, Patent Document 3 describes a thermoplastic resin composition obtained by blending thermally conductive carbon fibers and graphite. However, specifically, polyphenylene sulfide (PPS) is only used as the thermoplastic resin. In addition, the total amount of carbon fiber and graphite used is very large, and there is no description about the improvement of warpage of the molded product.

  Furthermore, Patent Document 4 describes a fiber reinforced resin composition obtained by blending 30 parts by weight or more of a carbon fiber aggregate having a thermal conductivity in the length direction of 400 W / m · K or more with 100 parts by weight of a thermoplastic resin. ing. However, there is only a specific example of blending with polybutylene terephthalate resin, there is no specific thermal conductivity, and there is actually a large blending amount of the carbon fiber aggregate, which is fluid. There is no description about the improvement of the warpage of molded products.

JP-A-8-283456 JP 2002-88250 A JP 2003-49081 A JP 2000-143826 A

  An object of the present invention is to provide a polycarbonate resin composition having excellent thermal conductivity and molding processability and less warping of a molded product, and a molded product thereof.

  As a result of intensive studies to solve the above problems, the present inventors have added a specific amount of specific heat conductive carbon fiber and graphite to an alloy of polycarbonate resin or polycarbonate and another resin, thereby increasing the heat. The present inventors have found that a resin composition excellent in conductivity and molding processability and having little warpage of a molded product and a molded product thereof can be obtained, and the present invention has been achieved.

  That is, the present invention is (B) graphitized carbon fiber based on (A) 100 parts by weight of a polycarbonate-based resin, and has a thermal conductivity of 100 W / m · K or more in the length direction and an average fiber diameter. 5 to 20 μm carbon fiber 5 parts by weight to less than 40 parts by weight and (C) 5 to 100 parts by weight of graphite powder having an average particle diameter of 1 to 500 μm A polycarbonate resin composition and a molded article obtained by molding the thermally conductive polycarbonate resin composition, particularly useful as a housing for OA, electrical / electronic parts, precision equipment parts The present invention relates to a molded body.

  The polycarbonate resin composition of the present invention is excellent in thermal conductivity and molding processability, has little warpage of a molded product, and gives a molded article having good dimensional stability. It is useful in many fields including electrical / electronic parts and casings for precision equipment.

The present invention will be described in detail below.
The (A) polycarbonate resin used in the present invention is not limited to a polycarbonate resin alone (a polycarbonate resin alone is an embodiment containing only one type of polycarbonate resin. For example, a plurality of types having different monomer compositions and molecular weights. Or an alloy (mixture) of a polycarbonate resin and another thermoplastic resin. The alloy preferably contains other thermoplastic resin in a proportion of 100 parts by weight or less, more preferably 70 parts by weight or less, relative to 100 parts by weight of the polycarbonate resin. The other thermoplastic resin is preferably a thermoplastic polyester resin or a styrene resin, more preferably a polybutylene terephthalate resin, a polyethylene terephthalate resin, or an acrylonitrile-butadiene-styrene copolymer, and more preferably a polycarbonate resin of 100 weight. A polycarbonate resin alloy containing 100 parts by weight or less of a polybutylene terephthalate resin or a polyethylene terephthalate resin, or a polycarbonate resin alloy containing 10 to 70 parts by weight of an acrylonitrile-butadiene-styrene copolymer. is there.

In the present invention, an aromatic polycarbonate resin, an aliphatic polycarbonate resin, or an aromatic-aliphatic polycarbonate resin can be used as the polycarbonate resin, and among them, the aromatic polycarbonate resin is preferable. The aromatic polycarbonate resin is a thermoplastic aromatic polycarbonate polymer or copolymer obtained by reacting an aromatic dihydroxy compound with phosgene or a diester of carbonic acid.
Examples of the aromatic dihydroxy compound include 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A), tetramethylbisphenol A, bis (4-hydroxyphenyl) -P-diisopropylbenzene, hydroquinone, resorcinol, 4, 4-dihydroxybiphenyl etc. are mentioned, Preferably bisphenol A is mentioned. Further, for the purpose of further enhancing the flame retardancy, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound, or a polymer or oligomer having a siloxane structure and containing both terminal phenolic OH groups is used. Can do.

The aromatic polycarbonate resin used in the present invention is preferably a polycarbonate resin derived from 2,2-bis (4-hydroxyphenyl) propane, or 2,2-bis (4-hydroxyphenyl) propane and other aromatics. And a polycarbonate copolymer derived from an aromatic dihydroxy compound. Further, two or more kinds of polycarbonate resins may be used in combination.
The molecular weight of the polycarbonate resin is a viscosity average molecular weight converted from the solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent, and is in the range of 14,000 to 30,000, preferably 15,000 to 28. 16,000, more preferably 16,000-26,000. If the viscosity average molecular weight is less than 14,000, the mechanical strength is insufficient, and if it exceeds 30,000, the moldability tends to be difficult, which is not preferable.
The method for producing such an aromatic polycarbonate resin is not limited, and the aromatic polycarbonate resin can be produced by a phosgene method (interfacial polymerization method), a melting method (transesterification method), or the like. Furthermore, the aromatic polycarbonate resin which adjusted the amount of OH groups of the terminal group manufactured by the melting method can be used.

  Furthermore, as the aromatic polycarbonate resin, not only virgin raw materials but also aromatic polycarbonate resins regenerated from used products, so-called material recycled aromatic polycarbonate resins can be used. Used products include optical recording media such as optical disks, light guide plates, automobile window glass and automobile headlamp lenses, vehicle transparent members such as windshields, containers such as water bottles, glasses lenses, soundproof walls and glass windows, waves A building member such as a plate is preferred. In addition, as the regenerated aromatic polycarbonate resin, non-conforming product, pulverized product obtained from sprue or runner, or pellets obtained by melting them can be used.

As another preferable thermoplastic resin used in the present invention, polyethylene terephthalate resin (PET) is produced by either a transesterification reaction between dimethyl terephthalate and ethylene glycol or a direct esterification reaction between terephthalic acid and ethylene glycol. But you can.
As other preferable thermoplastic resins used in the present invention, polybutylene terephthalate resin (PBT) includes DMT method by transesterification of dimethyl terephthalate and 1,4-butanediol, and terephthalic acid and 1,4-butanediol. It may be produced by any direct polymerization method.
In either case of the PET or PBT, phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, and the like together with terephthalic acid or a dialkyl ester thereof during the polycondensation reaction Dibasic acids such as dialkyl esters, tribasic acids and the like, and dialkyl esters thereof can be used. The amount used is preferably in the range of 40 parts by weight or less with respect to 100 parts by weight of terephthalic acid or a dialkyl ester thereof.

  Similarly, during the polycondensation reaction, together with the ethylene glycol or 1,4-butanediol, other aliphatic glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, hexamethylene glycol, In addition to the group glycol, for example, other diols such as cyclohexanediol, cyclohexanedimethanol, xylene glycol, 2,2-bis (4-hydroxyphenyl) propane, glycerin, pentaerythritol, and polyhydric alcohols can be used in combination. The amount of these diols or polyhydric alcohols used is preferably in the range of 40 parts by weight or less with respect to 100 parts by weight of the aliphatic glycol. The amount of these used is preferably in the range of 40 parts by weight or less with respect to 100 parts by weight of terephthalic acid or a dialkyl ester thereof.

The molecular weight of the polyester resin is an intrinsic viscosity measured at 30 ° C. in a mixed solvent of phenol and tetrachloroethane (weight ratio = 50/50), preferably 0.5 to 1.8, and more preferably 0. .7 to 1.5.
Furthermore, as PET and PBT of the present invention, not only virgin raw materials but also PET and PBT regenerated from used products, so-called material recycled PET and PBT can be used. Spent products include mainly containers, films, sheets, fibers, etc., but more suitable are containers such as PET bottles. In addition, as recycled PET and PBT, non-conforming products, pulverized products obtained from sprues, runners, etc., or pellets obtained by melting them can be used.
In the present invention, when (A) the polycarbonate-based resin is an alloy with a polybutylene terephthalate resin or a polyethylene terephthalate resin, a ratio of 100 parts by weight or less of the polybutylene terephthalate resin or the polyethylene terephthalate resin to 100 parts by weight of the polycarbonate resin. It is preferable to contain.

  Further, other preferable thermoplastic resins used in the present invention include styrene resins. Examples of the styrene resin include acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene copolymer, acrylonitrile-ethylenepropylene rubber-styrene copolymer, acrylonitrile-styrene-acrylic rubber copolymer, and the like. A bulk polymerization method or an emulsion polymerization method can be exemplified as a polymerization method of these styrene resins, and a resin polymerized by the bulk polymerization method is desirable.

Furthermore, as the styrene resin of the present invention, not only a virgin raw material but also a styrene resin regenerated from a used product, that is, a so-called material recycled styrene resin can be used. As a used product, a housing etc. are mainly mentioned. In addition, as the regenerated styrene resin, non-conforming products, pulverized products obtained from sprues, runners, etc., or pellets obtained by melting them can be used.
In the present invention, when the (A) polycarbonate resin is an alloy with a styrene resin, the (A) polycarbonate resin contains 100 parts by weight or less of the styrene resin with respect to 100 parts by weight of the polycarbonate resin. It is preferable.

  In the present invention, (B) carbon fiber formed by graphitization is used with 5 to less than 40 parts by weight of carbon fiber having a thermal conductivity in the length direction of 100 W / m · K or more and an average fiber diameter of 5 to 20 μm. To do. The carbon fiber preferably has a thermal conductivity in the length direction of 400 W / m · K or more.

(B) When the thermal conductivity of the graphitized carbon fiber is out of the above range, sufficient thermal conductivity cannot be obtained at a low filling rate as in the present invention. The carbon fibers used in the present invention are converged at a bulk density of 450 to 800 g / l, for example, carbon short fibers (chopped strands) usually cut to 2 to 20 mm as described in JP-A No. 2000-143826. Thus, a carbon short fiber convergent body that is then graphitized is preferred. The carbon short fiber converging body is obtained by converging carbon fibers with a sizing agent, cutting to a predetermined length, and graphitizing to reduce the content of the sizing agent to 0.1% by weight or less. It is. Examples of the conditions for the graphitization treatment include a method of heating at 2800 ° C. to 3300 ° C. in an inert gas atmosphere. As another method, continuous fibers (rovings) can be graphitized and then cut into a predetermined length for use. The average fiber diameter of the carbon fibers can be measured with an image analysis apparatus (for example, image processing R & D system TOSPIX-i manufactured by Toshiba Corporation), and is 5 to 20 μm. If it is less than 5 μm, it tends to cause problems such as a decrease in thermal conductivity when the polycarbonate resin is mixed and filled, and warpage of the molded product becomes large. Hateful. Moreover, when there is more content of a sizing agent than 0.1 weight%, it will be easy to cause the fall of heat conductivity. The blending amount of the carbon fiber is less than 40 parts by weight. Further, when the blending amount is less than 5 parts by weight, sufficient thermal conductivity cannot be obtained. The blending amount is preferably 10 parts by weight or more and less than 40 parts by weight, and more preferably 15 parts by weight or more and 35 parts by weight or less.
Further, (B) a carbon fiber is preferably used as the carbon fiber. For example, 1-30 mm, preferably 2-20 mm is used. Use of the long fiber-shaped material is effective in terms of improving thermal conductivity and reducing warpage of the molded product.

  In the present invention, in order to improve thermal conductivity and molding processability and reduce warpage of the molded product, (C) 5 to 100 parts by weight of graphite powder having an average particle diameter of 1 to 500 μm is used in combination. It is necessary. (C) The average particle diameter of the graphite powder is a value obtained by measuring the average particle diameter in accordance with JIS Z8819-2 by measuring with a laser diffraction method in accordance with JIS Z8825-1. When this value exceeds 500 μm, or when the content exceeds 100 parts by weight, the moldability deteriorates. (C) Even if the average particle diameter of the graphite powder is less than 1 μm, it is difficult to handle such as being scattered during blending, and it is difficult to uniformly disperse it in the resin. Furthermore, sufficient heat conductivity cannot be obtained as content is less than 5 weight part. (C) It is preferable that the average particle diameter of graphite powder is 5-100 micrometers. Further, when the amount of the carbon fiber (B) is small, the amount of (C) the graphite powder is relatively large, and is adjusted as appropriate so as to obtain a predetermined thermal conductivity. For example, when the amount of (B) carbon fiber is 5 to 25 parts by weight, the amount of (C) graphite powder is preferably 20 to 100 parts by weight, more preferably 20 to 80 parts by weight. Less than parts by weight. (B) When the amount of carbon fiber is 25 parts by weight or more and less than 40 parts by weight, the amount of (C) graphite powder is preferably 5 parts by weight or more and 40 parts by weight or less, more preferably 5 parts by weight or more. It is preferably 20 parts by weight or less.

  In the present invention, a flame retardant can be used to impart flame retardancy. The flame retardant is not particularly limited as long as it improves the flame retardancy of the composition, but a phosphoric acid ester compound, an organic sulfonic acid metal salt, and a silicone compound are preferable.

  As the phosphate ester compound used in the present invention, for example, a compound represented by the following formula (1) is preferable.

(In the formula, R ₁ , R ₂ , R ₃ , and R ₄ each independently represent an optionally substituted aryl group, and X represents a divalent aromatic group that may have another substituent. And n represents a number of 0 to 5.)
In the above formula (1), examples of the aryl group represented by R _{1 to} R ₄ include a phenyl group and a naphthyl group. Examples of the divalent aromatic group represented by X include a phenylene group, a naphthylene group, and a group derived from, for example, bisphenol. Examples of these substituents include an alkyl group, an alkoxy group, and a hydroxyl group. When n is 0, it is a phosphate ester, and when n is greater than 0, it is a condensed phosphate ester (including a mixture).

  Specific examples include bisphenol A bisphosphate, hydroquinone bisphosphate, resorcinol bisphosphate, resorcinol-diphenyl phosphate, and substituted and condensates thereof. Examples of commercially available condensed phosphate compounds that can be suitably used as such components include, for example, “CR733S” (resorcinol bis (diphenyl phosphate)), “CR741” (bisphenol A bis ( Diphenyl phosphate)) and Asahi Denka Kogyo Co., Ltd. under the trade name “FP500” (resorcinol bis (dixylenyl phosphate)) and are readily available.

  The content of the phosphate ester flame retardant in the composition of the present invention is 1 to 50 parts by weight, preferably 3 to 40 parts by weight, particularly preferably 5 to 30 parts by weight based on 100 parts by weight of the (A) polycarbonate resin. Parts by weight. If the content of the phosphate ester flame retardant is less than 1 part by weight, the flame retardancy is insufficient, and if it exceeds 50 parts by weight, the heat resistance is excessively lowered.

The organic sulfonic acid metal salt used in the present invention is preferably an aliphatic sulfonic acid metal salt or an aromatic sulfonic acid metal salt. The metal constituting the organic sulfonic acid metal salt is preferably an alkali metal, alkaline earth metal, etc., for example, sodium, lithium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium and the like. Can be mentioned. The organic sulfonic acid metal salt can also be used by mixing two or more kinds of salts.
The aliphatic sulfonate is preferably a fluoroalkane-sulfonic acid metal salt, more preferably a perfluoroalkane-sulfonic acid metal salt. The fluoroalkane-sulfonic acid metal salt is preferably an alkali metal salt of fluoroalkane-sulfonic acid or an alkaline earth metal salt of fluoroalkane-sulfonic acid, more preferably 4 to 8 carbon atoms. Examples thereof include alkali metal salts and alkaline earth metal salts of fluoroalkanesulfonic acid. Specific examples of the fluoroalkane-sulfonic acid metal salt include perfluorobutane-sodium sulfonate, perfluorobutane-potassium sulfonate, perfluoromethylbutane-sodium sulfonate, perfluoromethylbutane-potassium sulfonate, perfluoro Examples include octane-sodium sulfonate and potassium perfluorooctane-sulfonate.

  The aromatic sulfonic acid metal salt is preferably an aromatic sulfonic acid alkali metal salt, an aromatic sulfonic acid alkaline earth metal salt, an aromatic sulfone sulfonic acid alkali metal salt, or an aromatic sulfone sulfonic acid alkaline earth metal. Salts, and the like, and the aromatic sulfonesulfonic acid alkali metal salt and the aromatic sulfonesulfonic acid alkaline earth metal salt may be a polymer. Specific examples of the aromatic sulfonic acid metal salt include 3,4-dichlorobenzenesulfonic acid sodium salt, 2,4,5-trichlorobenzenesulfonic acid sodium salt, benzenesulfonic acid sodium salt, diphenylsulfone-3-sulfonic acid. Sodium salt, potassium salt of diphenylsulfone-3-sulfonic acid, sodium salt of 4,4′-dibromodiphenyl-sulfone-3-sulfonic acid, potassium salt of 4,4′-dibromodiphenyl-sulfone-3-sulfonic acid 4-chloro-4′-nitrodiphenylsulfone-3-sulfonic acid calcium salt, diphenylsulfone-3,3′-disulfonic acid disodium salt, diphenylsulfone-3,3′-disulfonic acid dipotassium salt, and the like. Can be mentioned.

  The compounding amount of the organic sulfonic acid metal salt is preferably 0.01 parts by weight or more and 5 parts by weight or less, more preferably 0.02 parts by weight or more and 3 parts by weight or less, with respect to 100 parts by weight of the (A) polycarbonate resin. Preferably they are 0.03 weight part or more and 2 weight part or less. If the amount of the organic sulfonic acid metal salt is less than 0.01 parts by weight, sufficient flame retardancy is difficult to obtain, and if it exceeds 5 parts by weight, the thermal stability tends to be lowered.

The silicone flame retardant used in the present invention is preferably a polyorganosiloxane having a linear or branched structure. The organic group possessed by the polyorganosiloxane includes hydrocarbons such as alkyl groups and substituted alkyl groups having 1 to 20 carbon atoms, vinyl and alkenyl groups, cycloalkyl groups, and aromatic hydrocarbon groups such as phenyl and benzyl. Chosen from.
Even if polydiorganosiloxane does not contain a functional group, it may contain a functional group. In the case of a polydiorganosiloxane containing a functional group, the functional group is preferably a methacryl group, an alkoxy group or an epoxy group.
These polyorganosiloxanes may be supported on silica.

  Further, in the present invention, for the purpose of preventing dripping at the time of combustion, an anti-dripping agent can be included, and a fluororesin is preferably used. Here, the fluororesin is a polymer or copolymer containing a fluoroethylene structure, for example, a difluoroethylene polymer, a tetrafluoroethylene polymer, a tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene and fluorine. It is a copolymer with an ethylene monomer that does not contain. Polytetrafluoroethylene (PTFE) is preferable, and the average molecular weight is preferably 500,000 or more, and particularly preferably 500,000 to 10,000,000.

As the polytetrafluoroethylene that can be used in the present invention, all types of polytetrafluoroethylene that are currently known can be used. However, when polytetrafluoroethylene having a fibril-forming ability is used, it is even higher. Melting dripping prevention property can be provided. Although there is no restriction | limiting in particular in the polytetrafluoroethylene (PTFE) which has a fibril formation ability, For example, what is classified into the type 3 in ASTM standard is mentioned. Specific examples thereof include, for example, Teflon (registered trademark) 6-J (manufactured by Mitsui DuPont Fluorochemical Co., Ltd.), Polyflon D-1, Polyflon F-103, Polyflon F201 (Daikin Industries, Ltd.), CD076 ( Asahi IC Fluoropolymers Co., Ltd.). Other than those classified as type 3, for example, Argoflon F5 (manufactured by Montefluos Co., Ltd.), polyflon MPA, polyflon FA-100 (manufactured by Daikin Industries, Ltd.) and the like can be mentioned. These polytetrafluoroethylene (PTFE) may be used independently and may combine 2 or more types. Polytetrafluoroethylene (PTFE) having the fibril-forming ability as described above is prepared by, for example, using tetrafluoroethylene in an aqueous solvent in the presence of sodium, potassium, ammonium peroxydisulfide, at a pressure of 1 to 100 psi, at a temperature of 0. It is obtained by polymerizing at ˜200 ° C., preferably 20˜100 ° C.
Alternatively, Teflon (registered trademark) 30-J (manufactured by Mitsui DuPont Fluorochemical Co., Ltd.) dispersed in a solvent may be used.

Further, it may be a polytetrafluoroethylene-containing mixed powder composed of polytetrafluoroethylene particles and organic polymer particles. Specific examples of monomers for producing organic polymer particles include styrene, p-methylstyrene, o-methylstyrene, p-chlorostyrene, o-chlorostyrene, p-methoxystyrene, o-methoxystyrene. Styrene monomers such as 2,4-dimethylstyrene, α-methylstyrene, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate (Meth) acrylic acid ester-based single quantities such as 2-ethylhexyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridodecyl acrylate, tridodecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate , Vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, vinyl ether monomers such as vinyl methyl ether and vinyl ethyl ether, vinyl carboxylate monomers such as vinyl acetate and vinyl butyrate, ethylene, propylene, isobutylene Examples thereof include, but are not limited to, olefin monomers such as diene monomers such as butadiene, isoprene and dimethylbutadiene. Preferably, two or more types of polymers or copolymers of these monomers can be used to obtain organic polymer particles.
The blending amount of the anti-dripping agent is preferably 0.05% by weight or more and 0.5% by weight or less, more preferably 0.2% by weight or more and 0.5% by weight or less in the polycarbonate resin composition. .

In the present invention, an elastomer can be included as an impact resistance improver for improving impact strength. The elastomer is not particularly limited, but a multilayer structure polymer is preferable. As a multilayer structure polymer, the thing containing an alkyl (meth) acrylate type polymer is mentioned, for example. These multi-layered polymers include, for example, polymers produced by continuous multi-stage seed polymerization in which a polymer in a previous stage is sequentially coated with a polymer in a subsequent stage, and a basic polymer. As a structure, it is a polymer having an outermost core layer made of a polymer compound that improves the adhesion between the inner core layer, which is a crosslinking component having a low glass transition temperature, and the matrix of the composition. A rubber component having a glass transition temperature of 0 ° C. or lower is selected as a component that forms the innermost core layer of these multilayer polymers. These rubber components include rubber components such as butadiene, rubber components such as styrene / butadiene, rubber components of alkyl (meth) acrylate polymers, polyorganosiloxane polymers and alkyl (meth) acrylate polymers. Or a rubber component using these in combination. Furthermore, examples of the component that forms the outermost core layer include an aromatic vinyl monomer, a non-aromatic monomer, or a copolymer of two or more thereof. Examples of the aromatic vinyl monomer include styrene, vinyl toluene, α-methyl styrene, monochloro styrene, dichloro styrene, bromo styrene, and the like. Of these, styrene is particularly preferably used. Examples of non-aromatic monomers include alkyl (meth) acrylates such as ethyl (meth) acrylate and butyl (meth) acrylate, vinyl cyanide such as acrylonitrile and methacrylonitrile, and vinylidene cyanide.
The amount of the impact modifier is preferably 1 to 10% by weight, more preferably 2 to 5% by weight in the polycarbonate resin composition.

Further, a reinforcing material can be added to the resin composition of the present invention in order to improve the elastic modulus, strength, and deflection temperature under load. Here, as a reinforcing material, silica, diatomaceous earth, pumice powder, pumice balloon, aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, calcium sulfate, potassium titanate, barium sulfate, calcium sulfite, talc, clay, mica, Examples thereof include glass fiber, glass flake, glass bead, calcium silicate, montmorillonite, bentonite, molybdenum sulfide, boron fiber, silicon carbide fiber, polyester fiber, polyamide fiber, and aluminum borate. Although not particularly limited, glass fiber, glass flake, talc and mica are preferred.
The blending amount of the impact resistance improver is preferably 1 part by weight or more and 100 parts by weight or less, more preferably 10 parts by weight or more and 80 parts by weight or less with respect to 100 parts by weight of the polycarbonate resin.

  Further, the resin composition of the present invention can be added with necessary amounts of stabilizers such as ultraviolet absorbers and antioxidants, and additives such as pigments, dyes, lubricants and mold release agents, as necessary.

  The method for obtaining the resin composition of the present invention is not particularly limited, and after kneading the above components with various kneaders, for example, uniaxial and multiaxial kneaders, Banbury mixers, rolls, Brabender plastograms, and the like. The above components are added to a method of cooling and solidifying, or to a suitable solvent such as hydrocarbons such as hexane, heptane, benzene, toluene, xylene and their derivatives, and dissolved components, or dissolved components and insoluble components are combined. A solution mixing method that mixes in a suspended state is used. The melt-kneading method is preferable from the industrial cost, but is not limited thereto. In melt kneading, it is preferable to use a single-screw or twin-screw extruder.

  In the present invention, it is preferable that the length of the (B) carbon fiber is longer in terms of thermal conductivity, improvement of warpage of the molded product, and the like. In addition, it is preferable that the (C) graphite powder is flat in terms of improvement in thermal conductivity and warpage of a molded product. Thus, when using a long carbon fiber as (B) and a flat graphite powder (scale-like graphite) as (C), this long fiber or flat powder is used when blended into the resin. It is advisable to consider the operating conditions at the time of blending so as not to break and shorten. For this purpose, for example, a method of feeding (B) carbon fiber and (C) graphite powder from the middle of the extruder during kneading is preferable. Among them, a method of feeding (B) carbon fiber and (C) graphite powder from the middle of the extruder using a twin screw extruder is preferable. By adopting such a method, it is possible to suppress breakage and shortening of the carbon fiber and the heat conductive powder during kneading, and stable production becomes possible.

  Alternatively, (B) carbon fiber or (C) graphite powder is mixed in advance with (A) a part of the polycarbonate-based resin, or (A) a part of the polycarbonate-based resin, or (A) a polycarbonate-based resin. A method of blending (B) carbon fiber and / or (C) graphite powder with a part of the above to prepare a masterbatch and then blending it with the remaining (A) polycarbonate resin is also included. If (A) the polycarbonate-based resin contains a resin other than the polycarbonate resin, (A) a part of the polycarbonate-based resin may be a part of the polycarbonate resin or a resin other than the polycarbonate resin. It may be part or all, or part of a mixture of polycarbonate resin and other resin. In the case of a mixture, even if the ratio of the resin composition of the master batch is different from the ratio of the target resin composition, it may be adjusted to the target ratio by adjusting the amount of components added later. When (B) carbon fiber or (C) graphite powder is composed of a plurality of types, all of them may be made into a master batch at the same time, or a part of them may be made into a master batch or a plurality of master batches. Or you may. Further, when there is a difference in dispersibility between (B) carbon fiber and (C) graphite powder between the polycarbonate resin and another resin, it is preferable to prepare a masterbatch with a resin in which they are well dispersed.

  The method for obtaining a molded body using the resin composition of the present invention is not particularly limited, and a molding method generally used for thermoplastic resin compositions such as injection molding, hollow molding, extrusion molding, and sheeting is used. A molding method such as molding, thermoforming, rotational molding, and lamination molding can be applied. Among them, a molded body obtained by injection molding is particularly preferable because it tends to have a high thermal conductivity.

  The molded body of the present invention is widely used for OA equipment parts, electrical / electronic parts, and precision equipment parts, but is particularly suitable for OA equipment casings, electrical / electronic equipment casings, and the like. A notebook, a mobile phone, a PDA, a digital camera, a projector, and the like. It is also suitable for internal parts of OA equipment and electrical / electronic equipment, for example, internal parts of connector members, personal computer members, mobile phones, printers, copiers, scanners, televisions, audio equipment, lighting, office equipment, AV equipment. Etc.

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these ranges.
In the following examples, the following components were used.
(A) Resin (A-1) Polycarbonate resin: Poly-4,4-isopropylidenediphenyl carbonate, manufactured by Mitsubishi Engineering Plastics Co., Ltd., trade name: Iupilon (registered trademark) S-3000, viscosity average molecular weight 21,000 (Hereafter abbreviated as PC)
(A-2) Polyethylene terephthalate resin: manufactured by Mitsubishi Chemical Corporation, trade name: Novapex (registered trademark) GG500 (hereinafter abbreviated as PET)
(A-3) Polybutylene terephthalate resin: manufactured by Mitsubishi Engineering Plastics Co., Ltd., trade name: NOVADURAN (registered trademark) 5010 (hereinafter abbreviated as PBT)
(A-4) Acrylonitrile-butadiene-styrene copolymer (ABS resin): Nippon A & L Co., Ltd., trade name UT-61 (hereinafter abbreviated as ABS)
(B-1) Carbon fiber: manufactured by Mitsubishi Chemical Industries, Ltd., trade name: DIALEAD K223HG, fiber diameter 10 μm, length 6 mm, sizing agent content 0.0%, thermal conductivity 540 W / m · K
(B-2) Carbon fiber: manufactured by Mitsubishi Chemical Industries, Ltd., trade name: DIALEAD K223GM, fiber diameter 10 μm, length 6 mm, sizing agent content 6.2%, thermal conductivity 20 W / m · K

(C-1) Scalar graphite: manufactured by Nishimura Graphite Co., Ltd., trade name PB-90, average particle size 26 μm
(C-2) Aluminum oxide: Showa Denko Co., Ltd., trade name AS-10, average particle size 39 μm, thermal conductivity 30 W / m · K
(C-3) Aluminum nitride: manufactured by Tokuyama Corporation, trade name SH02-SW10 type I, average particle size 12.6 μm, heat conduction HP-1CA, average particle size 16 μm, heat conductivity 60 W / m · K
(D-1) Flame retardant: Phosphate ester compound: Resorcinol bis (dixylenyl phosphate), manufactured by Asahi Denka Kogyo Co., Ltd., trade name: FP500
(D-2) Flame retardant: Potassium perfluorobutanesulfonate: Product name, KFBS, manufactured by Tochem Products Co., Ltd.
(E) Fluororesin: Polytetrafluoroethylene, manufactured by Daikin Industries, Ltd., trade name: Polyflon F-201L
(F) Elastomer: (Butadiene & Styrene) Core / Acrylic Shell Multi-layer Structure Polymer, manufactured by Mitsubishi Rayon Co., Ltd., trade name: METABRENE E-901
(G) Glass flake: Nippon Sheet Glass Co., Ltd., trade name Micro Glass Flaker REFG101

Examples 1-8, Comparative Examples 1-4
(A) Polycarbonate resin, flame retardant, fluororesin, elastomer, and glass flakes prepared at the ratio shown in Table 1 were uniformly mixed with a tumbler mixer, and then a twin-screw extruder (manufactured by Nippon Steel Works, TEX30XCT, L / D = 42, barrel number 12), cylinder temperature 280 ° C., screw rotation speed 200 rpm, feed from the barrel 1 upstream of the extruder to the extruder, melt knead, and further in the middle of the extruder kneading part From the barrel 7, (B) carbon fiber and (C) graphite powder were fed to the extruder at a ratio shown in Table 1 and melt kneaded to pelletize the resin composition.
The following (1) to (4) were evaluated using this resin composition. The results are shown in Table 1.

[Evaluation method]
(1) Thermal conductivity Using an injection molding machine (manufactured by Sumitomo Heavy Industries, SH100, mold clamping force 100T), resin temperature (measured temperature of purge resin): 300 ° C, mold temperature: 110 ° C, Mold: 100 mm long, 100 mm wide, 3 mm thick molded product was injection molded under the condition of injection pressure: 147 MPa, and the resulting injection molded products were stacked three times to quickly measure the thermal conductivity (Kyotherm Electronics, Chemtherm QTM-D3) was used to measure the thermal conductivity of the injection molded product.
(2) Flow length Resin temperature (measured temperature of purge resin): 300 ° C., mold temperature: 100 ° C. using an injection molding machine (SG75 Cycap M-2, mold clamping force 75T, manufactured by Sumitomo Heavy Industries, Ltd.) , Mold: 20 mm width × 2 mm thickness, injection pressure: 147 MPa, the flow length was measured.
(3) Sled Using an injection molding machine (TOSHIKI MACHINE, IS150, mold clamping force 150T), with a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C., a box type of 150 mm × 150 mm / height 20 mm / thickness 2 mm A test piece was molded. Next, the warpage of the top surface of the test piece was measured using a three-dimensional measuring machine manufactured by Mitutoyo Corporation. The measurement was performed at 15 points at 10 mm intervals along the center line of the top surface, and the maximum amount of depression from the reference line connecting both ends was defined as a warp.

(4) Flame retardance According to the test method shown in UL-94 “Flame Test for Material Classification” (hereinafter referred to as UL-94) of Underwriters Laboratories, Inc. The test piece was tested, and based on the result, it was evaluated to any one of UL-94 standard V-0, V-1 and V-2. The test piece was injection molded under the conditions of resin temperature (measured temperature of purge resin) 290 ° C., mold temperature 90 ° C., injection pressure 147 MPa, using an injection molding machine (manufactured by Nippon Steel, J50, mold clamping force 50T). did. The grade criteria for UL-94 are outlined below.
(I) V-0: Combustion time after flame contact for 10 seconds is 10 seconds or less, total combustion time of 5 tubes is 50 seconds or less, and all the test pieces do not drop fine flames that ignite absorbent cotton.
(Ii) V-1: Combustion time after flame contact for 10 seconds is 30 seconds or less, 5 total combustion times are 250 seconds or less, and all test specimens do not drop fine flames that ignite absorbent cotton .
(Iii) V-2: Combustion time after flame contact for 10 seconds is 30 seconds or less, 5 total combustion times are 250 seconds or less, and absorbent cotton is ignited from the particulate flame dropped from these test pieces.
(Iv) NG: When it does not correspond to any of the above burning times and continues to burn.

Examples 1 and 5 to 7 are reference examples.
By comparing Examples 1 to 8 and Comparative Examples 1 to 4, a specific amount of specific heat conductive carbon fiber and graphite powder are added to the alloy of polycarbonate resin or polycarbonate and other resin, thereby increasing the heat conductivity. It is apparent that a resin composition excellent in molding processability, little warpage of the molded product, and excellent in surface smoothness and a molded body thereof can be obtained.

  The polycarbonate resin composition of the present invention is excellent in thermal conductivity and molding processability, has little warpage of a molded product, and gives a molded article having good dimensional stability, and therefore has great industrial utility. In addition, a molded product using the same is useful in many fields including OA equipment, electrical / electronic parts, and precision equipment casings.

Claims (10)

(A) Carbon fiber made of (B) graphitized with respect to 100 parts by weight of polycarbonate-based resin, having a thermal conductivity in the length direction of 400 W / m · K or more, a length of 1 to 30 mm, and a fiber average diameter 5~20μm carbon fiber 25 parts by weight or more than 40 parts by weight, and (C) Ri average particle size name contained 40 parts by weight or less scaly graphite powder 5 parts by weight or more of 1 to 500 [mu] m, (a) The heat conductive polycarbonate resin composition, wherein the polycarbonate resin is a polycarbonate resin alone or a polycarbonate resin alloy containing 100 parts by weight or less of a styrene resin with respect to 100 parts by weight of the polycarbonate resin. . Furthermore, the heat conductive polycarbonate-type resin composition of Claim 1 formed by mix | blending a flame retardant. The heat conductive polycarbonate-type resin composition of Claim 2 whose said flame retardant is a phosphate ester compound shown by following formula (1).

(In the formula, R ₁ , R ₂ , R ₃ , and R ₄ each independently represent an optionally substituted aryl group, and X represents a divalent aromatic group that may have another substituent. And n represents a number of 0 to 5.) Furthermore, the heat conductive polycarbonate-type resin composition of any one of Claims 1-3 formed by mix | blending an anti-dripping agent. The heat conductive polycarbonate-type resin composition of Claim 4 whose said dripping prevention agent is the polytetrafluoroethylene which has fibril formation ability. Furthermore, the heat conductive polycarbonate-type resin composition of any one of Claims 1-5 formed by mix | blending an elastomer as an impact resistance improving agent. Furthermore, the heat conductive polycarbonate-type resin composition of any one of Claims 1-6 formed by mix | blending a reinforcing material. A molded article obtained by molding the thermally conductive polycarbonate resin composition according to any one of claims 1 to 7 . The molded article according to claim 8 , which is a housing for OA, electrical / electronic parts, precision equipment parts. 15 of 10 mm intervals along the center line of the top surface of a box-shaped molded body having an area of 150 mm × 150 mm, a height of 20 mm, and a thickness of 2 mm, which is injection-molded under conditions of a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C. The molded article according to claim 8 or 9, wherein the maximum amount of depression from a reference line obtained by measuring points and connecting both ends is 280 µm or less.