JP4768302B2 - Molded body made of highly heat conductive insulating polycarbonate resin composition - Google Patents

Description

  The present invention relates to a polycarbonate resin composition excellent in thermal conductivity, having a large surface resistance and insulating properties, excellent in moldability and free from 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. In OA and electrical / electronic parts, there are many uses that require insulation, and materials having both high thermal conductivity and insulation are desired.

  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 by a resin composition filled with both high thermal conductivity inorganic fibers and high thermal conductivity inorganic powder. 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, and electrical conductivity of the composition 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, the patent document 2 mainly focuses on increasing the filling amount in the resin in order to obtain high thermal conductivity, and the type of the polymer material is not specified, and silicone rubber, epoxy resin In addition to thermoplastic elastomers, only polyacetal is used as the thermoplastic resin, all of which are used as a housing for OA, electrical / electronic parts, precision instruments, etc. in terms of strength, appearance, etc. However, it is not intended to improve moldability, warpage of injection-molded products, and dimensional stability. Moreover, the electrical conductivity of the composition has not been evaluated at all.

  Furthermore, Patent Document 3 describes a thermoplastic resin obtained by blending a heat conductive carbon fiber and graphite. Specifically, polyphenylene sulfide (PPS) is only used as the thermoplastic resin. Moreover, the total amount of carbon fiber and graphite used is very large, and there is no description regarding the warpage of the molded product and the conductivity of the composition.

  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 / mk or more with 100 parts by weight of a thermoplastic resin. Yes. However, specifically, only an example blended with polybutylene terephthalate resin is described, there is no specific heat conductivity, and the amount of the carbon fiber aggregate is large. There is no description about the sled and the conductivity of the composition.

  Patent Document 5 describes a method for producing vapor grown carbon fiber coated with boron nitride, and further using the vapor grown carbon fiber as a filler produces an insulating high thermal conductivity material. It describes what you can do. However, specific examples of addition are not shown, and in order to produce carbon fibers coated with boron nitride, not only does the cost of equipment such as a heat treatment furnace increase, but the productivity is also poor and practical level. It has not reached.

JP-A-8-283456 JP 2002-88250 A JP 2003-49081 A JP 2000-143826 A JP 2002-235279 A

  An object of the present invention is to provide a polycarbonate resin composition having excellent thermal conductivity, a large surface resistance and insulating properties, excellent molding processability, and less warping of a molded product, and a molded body thereof. To do.

  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 boron nitride powder to an alloy of polycarbonate resin or polycarbonate and another resin. The present inventors have found that a resin composition having excellent thermal conductivity, large surface resistance, insulating properties, excellent molding processability and little warpage of a molded product, and a molded product thereof can be obtained. As a result of further studies based on this finding, the present invention has been completed.

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. The present invention relates to a thermally conductive polycarbonate resin composition containing 5 parts by weight or more and less than 40 parts by weight of 5-20 μm carbon fiber and (C) 5 parts by weight or more and 100 parts by weight or less of boron nitride having an average particle diameter of 1 to 500 μm.
Moreover, this invention relates to the molded object formed by shape | molding the said polycarbonate-type resin composition. The molded body of the present invention is useful as an internal part that requires insulation, such as OA, electrical / electronic, precision equipment, and automobiles.

  The polycarbonate-based resin composition of the present invention is a polycarbonate-based resin composition having excellent thermal conductivity, large surface resistance and insulation, excellent molding processability, and little warpage of a molded product. Its industrial usefulness is great, and it is a material useful for the manufacture of parts such as machines and devices in various fields such as OA equipment, electrical and electronic parts, precision equipment, and automobile-related parts that require insulation.

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 100 parts by weight or less of the other thermoplastic resin with respect to 100 parts by weight of the polycarbonate resin, more preferably 70 parts by weight or less. The other thermoplastic resin is preferably a thermoplastic polyester resin, more preferably a polybutylene terephthalate resin or a polyethylene terephthalate resin, and still more preferably 10 polybutylene terephthalate resin or polyethylene terephthalate resin per 100 parts by weight of the polycarbonate resin. It is a polycarbonate resin type alloy contained in a proportion of ˜70 parts by weight.

In the present invention, aromatic polycarbonate, aliphatic polycarbonate, and aromatic-aliphatic polycarbonate can be used as the polycarbonate resin. Among them, aromatic polycarbonate is preferable. The aromatic polycarbonate resin is a thermoplastic aromatic polycarbonate polymer or copolymer produced 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-dihydroxydiphenyl etc. are mentioned, Preferably bisphenol A is mentioned. Further, for the purpose of further enhancing the flame retardancy, a compound or oligomer having both terminal phenolic OH groups having a siloxane structure and / or a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound is used. be able to.

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 is liable to be difficult.
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, a polyethylene terephthalate resin (PET) may be produced by either a transesterification reaction between dimethyl terephthalate and ethylene glycol or a direct esterification reaction between terephthalic acid and ethylene glycol. .
The polybutylene terephthalate resin (PBT) used in the present invention can be produced by either a DMT method by transesterification of dimethyl terephthalate and 1,4-butanediol, or a direct polymerization method of terephthalic acid and 1,4-butanediol. It may be good.
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 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.

  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, (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.

When the thermal conductivity of (B) is out of the above range, sufficient thermal conductivity cannot be obtained at a low filling rate as in the present invention. The carbon fiber used in the present invention converges carbon short fibers (chopped strands) usually cut to 2 to 20 mm at a bulk density of 450 to 800 g / l, as described in, for example, JP-A No. 2000-143826. And a short carbon fiber convergent body that is then graphitized. 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 diameter of the carbon fiber is preferably 5 to 20 μm, and 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 becomes large. Decreases and a good appearance is difficult to obtain. Moreover, when there is more content of a sizing agent than 0.1 weight%, it will cause the fall of thermal conductivity. The blending amount of the carbon fiber is less than 40 parts by weight, and if it is more than this, molding processability and dimensional stability are lowered and warpage is increased. Further, when the blending amount is less than 5 parts by weight, sufficient thermal conductivity cannot be obtained. The blending amount is preferably less than 10 to 40 parts by weight, and more preferably 15 to 35 parts by weight.
Further, as the carbon fiber, a long fiber is preferably used. For example, 1-30 mm, preferably 2-20 mm is used. Use of the long fiber is effective in improving thermal conductivity and reducing warpage of the molded product.

  In the present invention, in order to provide insulation, improve thermal conductivity and molding processability, and reduce warpage of the molded product, (C) average particle diameter with respect to 100 parts by weight of the polycarbonate-based resin. 5 to 100 parts by weight of boron nitride having a thickness of 1 to 500 μm. When the average particle diameter of the component (C) exceeds 500 μm, or when the content exceeds 100 parts by weight, the moldability is lowered. Even if the average particle size of the component (C) is less than 1 μm, it is difficult to handle such as being scattered during compounding, and it is difficult to uniformly disperse it in the resin. Further, if the content is less than 5 parts by weight, sufficient thermal conductivity and insulation cannot be obtained. Moreover, the preferable range of content of (C) component changes with content of (B) component used together, and it is preferable to set it as an equivalent weight part or more with (B) component. When the content is less than the component (B), sufficient thermal conductivity and insulation may not be obtained. In addition, when the content of the carbon fiber that is the component (B) is small, the content of the boron nitride that is the component (C) is relatively large, and is adjusted as appropriate so as to obtain a predetermined thermal conductivity. It is also preferable. For example, when the amount of carbon fiber (B) is 10 parts by weight or more and less than 40 parts by weight, the content of boron nitride (C) is preferably 10 parts by weight or more and 90 parts by weight or less, and the carbon fiber (B) When the content of is 15 parts by weight or more and 35 parts by weight or less, the content of boron nitride (C) is preferably 15 parts by weight or more and 80 parts by weight or less.

  Boron nitride has a plurality of stable structures such as c-BN (zinc blende structure), w-BN (wurtzite structure), h-BN (hexagonal crystal structure), and r-BN (rhombohedral crystal structure). It has been known. In the present invention, any boron nitride may be used. Among them, hexagonal structure boron nitride is preferably used. In addition, there are spherical and scaly boron nitrides, and any of them can be used in the present invention. However, when a scaly material is used, a molded product with better insulation can be obtained. It is preferable because the mechanical properties are improved. The average particle diameter of the scaly boron nitride powder is generally 1 to 50 μm, and it is also preferable to use a powder having an average particle diameter in such a range. However, the specific gravity and average particle diameter of boron nitride used in the present invention are not limited to this range.

  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 arikari metal organic sulfonic acid metal salt, and a silicone compound are preferable.

  As a phosphoric acid ester compound used by this invention, the compound shown by following formula (1) is preferable, for example.

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently an aryl group which may be substituted, and X is a divalent aromatic which 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 hydroxy 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, resorcin 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 5 parts by weight based on 100 parts by weight of the (A) polycarbonate resin. 30 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 alkali metal salt 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, an alkaline earth metal, etc., and the alkali metal and alkaline earth metal include sodium, lithium, potassium, rubidium, cesium, beryllium, magnesium. , Calcium, strontium and barium. 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. Preferred examples of the fluoroalkane-sulfonic acid metal salt include an alkali metal salt of fluoroalkane-sulfonic acid, an alkaline earth metal salt of fluoroalkane-sulfonic acid, and more preferably, a fluoroalkane having 4 to 8 carbon atoms. Examples include alkali metal salts and alkaline earth metal salts of alkanesulfonic acid. Specific examples of the fluoroalkane-sulfonate include perfluorobutane-sodium sulfonate, potassium perfluorobutane-sulfonate, perfluoromethylbutane-sodium sulfonate, potassium perfluoromethylbutane-sulfonate, perfluorooctane. -Sodium sulfonate, potassium perfluorooctane-sulfonate, and tetraethylammonium salt of perfluorobutane-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. Examples thereof include aromatic sulfonesulfonic acid alkali metal salts and aromatic sulfonesulfonic acid alkaline earth metal salts. 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, and 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, Examples include calcium salt of 4-chloro-4′-nitrodiphenylsulfone-3-sulfonic acid, disodium salt of diphenylsulfone-3,3′-disulfonic acid, and dipotassium salt of diphenylsulfone-3,3′-disulfonic acid. It is done.

  The amount of the organic sulfonic acid metal salt is preferably 0.01 to 5 parts by weight, more preferably 0.02 to 3 parts by weight, and particularly preferably 0.03 to 3 parts by weight with respect to 100 parts by weight of the (A) polycarbonate resin. 2 parts by weight. 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 direct 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.

  Moreover, in this invention, a fluororesin can be included for the purpose of dripping prevention at the time of combustion. 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 polytetrafluoroethylene that can be used in the present invention, all of the currently known types can be used.

  In addition, when polytetrafluoroethylene having a fibril forming ability is used, it is possible to impart higher melt dripping prevention property. 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.

In the present invention, an elastomer may be included to improve impact strength.
As the elastomer, various known materials can be used and are 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.

In addition, the resin composition of the present invention is optionally provided with stabilizers such as ultraviolet absorbers and antioxidants, additives such as pigments, dyes, lubricants, mold release agents, glass fibers, glass flakes and the like. An agent or a reinforcing material such as whisker such as potassium titanate or aluminum borate can be added.
As a method for obtaining the polycarbonate resin composition of the present invention, the above components are kneaded in various kneaders such as a uniaxial and multiaxial kneader, a Banbury mixer, a roll, a Brabender plastogram, etc., and then cooled and solidified. The above components are added to an appropriate solvent, for example, hydrocarbons such as hexane, heptane, benzene, toluene, xylene and their derivatives, and dissolved components, or dissolved components and insoluble components are suspended. The solution mixing method etc. which mix with are 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, (B) a longer carbon fiber is preferable in terms of thermal conductivity, improvement of warpage of a molded product, and the like. When such a long carbon fiber (B) is used, it is advisable to consider the operating conditions at the time of blending so that the long fibers are not broken and shortened when blended into the resin. For this purpose, for example, a method of feeding carbon fiber (B) and boron nitride (C) from the middle of the extruder during kneading is preferable. Among them, a method of feeding a carbon fiber (B) and boron nitride (C) from the middle of the extruder using a twin screw extruder is preferable. By adopting such a method, it is possible to prevent the carbon fiber from being broken and shortened during kneading, and to achieve stable production.

  Alternatively, the carbon fiber (B) is mixed in advance with a part of the polycarbonate resin (A) to form a carbon fiber coated with a part of the resin (A), or after preparing a masterbatch, the remaining The method of mix | blending with resin (A) of this is also mentioned. If the resin (A) contains a resin other than the polycarbonate resin, even if the resin (A) is a resin other than the polycarbonate resin, the polycarbonate resin and the other resin An alloy may be sufficient and a polycarbonate resin alone may be sufficient. In the case of an alloy, it may be different from the ratio of the target resin composition. Further, when there is a difference in the dispersibility of the carbon fiber and boron nitride between the polycarbonate resin and the other resin, it is preferable to prepare a masterbatch with a resin in which the carbon fiber and boron nitride 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, for example, injection molding, hollow molding, extrusion molding, sheet A molding method such as molding, thermoforming, rotational molding, and lamination molding can be applied. Among them, a molded body obtained by injection molding tends to have a particularly high thermal conductivity.
The molded body of the present invention is widely used for OA equipment parts, electrical and electronic parts, precision equipment and automobile-related parts that are required to have insulation properties, and is particularly suitable for internal parts of OA equipment and electrical and electronic equipment. Examples include connector members, personal computer members, televisions, audio equipment, lighting, office equipment, AV equipment members, and the like.

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: S-3000, viscosity average molecular weight 21,000 (hereinafter referred to as PC) (Abbreviated)
(A-2) Polyethylene terephthalate resin: manufactured by Mitsubishi Chemical Corporation, trade name: Novapex GG500 (hereinafter abbreviated as PET)
(A-3) Polybutylene terephthalate resin: manufactured by Mitsubishi Engineering Plastics Co., Ltd., trade name: Nova Duran 5010 (hereinafter abbreviated as PBT)
(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-2) Boron nitride: manufactured by Mizushima Alloy Iron Co., Ltd., trade name FS-3, average particle size 50 μm, thermal conductivity 60 W / m · K, spherical, hexagonal crystal, specific gravity 2.3 g / cm ³
(C-3) Boron nitride: manufactured by Mizushima Alloy Iron Co., Ltd., trade name HP-30, average particle size 6 μm, scaly, hexagonal, specific gravity 2.3 g / cm ³
(C-4) Boron nitride: manufactured by Mizushima Alloy Iron Co., Ltd., trade name HP-1CA, average particle size 16 μm, scaly, hexagonal, specific gravity 2.3 g / cm ³
(D-1) Scalar graphite: manufactured by Nishimura Graphite Co., Ltd., trade name: PB-90, average particle size 26 μm
(D-2) Aluminum oxide: Showa Denko Co., Ltd., trade name AS-10, average particle size 39 μm
(D-3) Aluminum nitride: manufactured by Tokuyama Corporation, trade name SH02-SW10 type I, average particle size 12.6 μm
Flame retardant: Phosphate ester compound: Resorcinol bis (dixylenyl phosphate), manufactured by Asahi Denka Kogyo Co., Ltd., trade name: FP500
Fluororesin: Polytetrafluoroethylene, manufactured by Daikin Industries, Ltd., trade name: Polyflon F-201L
Elastomer: (Butadiene & Styrene) Core / Acrylic Shell Multi-layer Structure Polymer, manufactured by Mitsubishi Rayon Co., Ltd., trade name: METABRENE E-901

Examples 1-2, 4, 5, Comparative Examples 1-6 , 7 and Reference Examples 1-3
(A) Polycarbonate resin, flame retardant, fluororesin and elastomer prepared in the proportions shown in Tables 1 and 2 were uniformly mixed in a tumbler mixer, and then a twin screw extruder (Nippon Steel Works, TEX30XCT, L / D = 42, barrel number 12), cylinder temperature 280 ° C., screw rotation speed 200 rpm, feed from barrel 1 to extruder, melt knead, and barrel 7 (B) carbon fiber and (C) nitriding Boron powder or (D) other filler was fed to the extruder at a ratio shown in Tables 1 and 2 and melt-kneaded to pelletize the resin composition.

-Production of press-molded product The obtained resin composition was subjected to a press temperature of 260 ° C, a residual heat of 8 minutes, a press of 20 seconds, and a cooling of 2 minutes using an automatic hot press (manufactured by Otake Machinery Co., Ltd., 380 square, 65 tons). A press-molded product having a thickness of 2 mm was produced under the conditions.
-Production of injection molded product The obtained resin composition was subjected to conditions of cylinder temperature 280 ° C and mold temperature 80 ° C using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., Cycap M-2, clamping force 75T). Then, an injection molded product of 100 mm × 100 mm × 3 mmt was produced.

[Evaluation methods]
(1) Thermal conductivity About the composition shown in Table 1, about the sample which piled up the press-molded goods produced by the said method, rapid thermal conductivity measuring apparatus (Kyoto Electronics Industrial make, Chemtherm QTM-D3) is used. Used to measure thermal conductivity.
Moreover, about the resin composition shown in Table 2, the heat conductivity was similarly measured about the sample which piled up three injection-molded articles produced by the said method.
(2) Surface resistivity About the resin composition shown in Table 1 and Table 2, about the molded product produced by the same method as said (1), using a digital ultrahigh resistance / microammeter (made by ADVANTEST, R8340) The surface resistivity was measured.
(3) Flow length About the compositions shown in Tables 1 and 2, the resin temperature (measured temperature of purge resin) was measured using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., Psycap M-2, clamping force 75T). ): 290 ° C., mold temperature: 80 ° C., mold: 20 mm width × 1 mm thickness, injection pressure: 147 MPa The flow length was measured.
(4) Warp About the compositions shown in Table 1 and Table 2, using an injection molding machine (manufactured by TOSHIBA MACHINE, mold clamping force 150T) under conditions of a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C., 150 mm × 150 mm / A box-shaped test piece having a height of 20 mm and a thickness of 2 mm was formed. 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.

(5) Flame retardancy For the compositions shown in Tables 1 and 2, according to the test method shown in UL-94 “Flame Test for Material Classification” (hereinafter referred to as UL-94) of Underwriters Laboratories Inc. Based on the results of five test pieces having a thickness of 1/16 inch, the grade was evaluated as one of UL-094 V-0, V-1 and V-2 grades. The grade criteria for each V 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 test pieces do not drop a particulate flame that ignites 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.

  From the results shown in Table 1 and Table 2 above, the molded products of the examples all have excellent thermal conductivity, large surface resistance and insulation, excellent molding processability, and little warpage of the molded products. Recognize. Reference Examples 1 to 3 are examples in which flaky graphite, aluminum oxide and aluminum nitride are used instead of boron nitride, but the molded products of the examples have a surface resistivity as compared with these reference examples. It was remarkably large and excellent in insulation.

  The polycarbonate-based resin composition of the present invention is a polycarbonate-based resin composition molded body having excellent thermal conductivity, large surface resistance, insulating properties, excellent molding processability, and less warping of molded products, and its industrial It is useful in many fields, such as OA equipment, electrical / electronic parts, precision equipment, and automobile-related internal parts that require insulation.

Claims (10)

(A) Carbon fiber (B) is graphitized carbon fiber with respect to 100 parts by weight of polycarbonate-based resin, and has a thermal conductivity of 100 W / m · K or more in the length direction and an average fiber diameter of 5 to 20 μm. 5 parts by weight or more and less than 40 parts by weight of fiber, (C) 5 parts by weight or more and 100 parts by weight or less of boron nitride having an average particle diameter of 1 to 500 μm, and (D) Phosphate ester compound 1 represented by the following general formula (1) A molded article comprising a polycarbonate-based resin composition containing from 50 parts by weight to 50 parts by weight, wherein the molded article has a surface resistivity of 10 ¹² Ω / □ or more at a thickness of 3 mm .

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently an aryl group which may be substituted, and X is a divalent aromatic which may have another substituent. And n represents a number of 0 to 5.) (C) Boron nitride is hexagonal boron nitride, The molded object which consists of a polycarbonate-type resin composition of Claim 1. (C) Boron nitride is scaly, The molded object which consists of a polycarbonate-type resin composition of Claim 1 or 2. (A) The polycarbonate resin is a polycarbonate resin alloy containing a polycarbonate resin alone or a polybutylene terephthalate resin or a polyethylene terephthalate resin in a proportion of 100 parts by weight or less with respect to 100 parts by weight of the polycarbonate resin. The molded object which consists of a polycarbonate-type resin composition of any one of Claims. The molding comprising the polycarbonate-based resin composition according to any one of claims 1 to 4, wherein the carbon fiber (B) has a thermal conductivity in the length direction of 400 W / m · K or more. The body . Polycarbonate-based resin composition further is made by blending the anti-drip agent, molded article comprising the polycarbonate resin composition according to any one of claims 1-5. Polycarbonate-based resin composition further is made by blending an elastomer as an impact modifier, molded article comprising the polycarbonate resin composition according to any one of claims 1-6. The molded article according to any one of claims 1 to 7, which is an internal part of OA, electrical / electronic, precision equipment or automobile. The flow length measured under conditions of an injection pressure of 147 MPa with a mold having a resin temperature of 290 ° C, a mold temperature of 80 ° C, a 20 mm width x 1 mm thickness using an injection molding machine is 110 mm or more. The molded object of any one of Claims. The molded article according to any one of claims 1 to 9, which is an injection-molded product.