JP2008163270A - Polyester-based resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition that can give a resin molded article excellent in conductivity, shielding property against electromagnetic waves, mechanical strength, thermal stability, flame retardancy and external appearance. <P>SOLUTION: The thermoplastic resin composition comprises 50-95 wt.% of a polycarbonate resin (A1) and/or a polyester resin (A2) and 50-5 wt.% of graphite (B), wherein the polycarbonate resin (A1) and/or the polyester resin (A2) and the graphite having a water content of ≤0.2% are combined. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin composition having excellent conductivity. More specifically, by blending specific graphite, it not only prevents electrification, but also exhibits excellent electrical conductivity, as well as mechanical strength, heat resistance, flame retardancy, melt heat stability and appearance. The present invention relates to a resin composition.

  From a polycarbonate resin whose main chain is a repeating unit containing a carbonate bond (—R—O—C (═O) —O—) or a repeating unit containing an ester bond (—R—C (═O) —O—) Polyester resins such as aromatic polyester resin, liquid crystalline polyester resin, and polyarylate resin are excellent in mechanical properties, electrical properties, heat resistance, etc., so electrical / electronic / OA equipment parts, mechanical parts, etc. Is used in many applications.

  These polycarbonate resins and polyester resins have excellent characteristics, but have high electrical resistivity, so that they are easily charged and may cause various troubles due to static electricity. For example, if a resin molded product is charged with static electricity (charges), dust and dust adhere to the surface, resulting in a decrease in appearance and a decrease in commercial value. Especially in electrical / electronic / OA equipment parts applications, charging of this resin molded product may cause erroneous operation and may cause serious functional problems. Therefore, there is a resin material that prevents charging and exhibits excellent conductivity. It has been demanded.

  Also, in electrical / electronic / OA equipment, the electronic components inside the resin molded product, which is the casing, generate electromagnetic waves. Therefore, in order to prevent electromagnetic waves from leaking outside the equipment, plating or vapor deposition is usually used as an electromagnetic shielding layer. A metal film is formed on the surface of the housing by a method such as the above. In recent years, in order to simplify the product manufacturing process and diversify product design, there is a demand for a resin composition that has this electromagnetic shielding property to the resin material of the casing itself, that is, an excellent electromagnetic shielding property. .

As a method for imparting conductivity and electromagnetic wave shielding properties to the resin composition, it is known to add graphite to a polycarbonate resin or a polyester resin. For example, as a resin composition having high solder heat resistance, small anisotropy and warpage, and excellent electrical conductivity with a surface resistivity of 1 × 10 ⁴ to 1 × 10 ⁸ Ω, the average particle size is 5 μm or more. There has been proposed a liquid crystalline polyester resin composition or the like in which graphite and talc having an average particle size of 5 μm or more are blended (see, for example, Patent Document 1).

  In addition, as a resin composition excellent in conductivity, heat resistance, heat stability, low water absorption, and dimensional stability, a composition comprising a conductive filler such as graphite and a polyarylate resin (see, for example, Patent Document 2), As a resin composition having high rigidity and low mechanical property and conductivity anisotropy, a composition comprising a thermoplastic resin such as a polycarbonate resin and a graphite powder having an aspect ratio of 70% or more and a particle of 3 or less is proposed. (For example, refer to Patent Document 3).

  And as exterior parts for vehicles that have conductivity, heat resistance, impact resistance, dimensional stability and surface appearance of molded products, thermoplastic resins such as polyester resins, impact resistance improvers, average particle size of 1 to 70 μm A vehicle exterior part obtained from a thermoplastic resin composition made of graphite and an antistatic resin has been proposed (see, for example, Patent Document 4).

  Furthermore, it comprises a non-fibrous carbon filler such as polycarbonate resin and graphite, and a flow modifier as a resin composition having both excellent antistatic properties without delamination, mechanical strength, flow characteristics and good heat resistance. Resin compositions have been proposed (see, for example, Patent Document 5).

  Further, it prevents hydrolysis of the polyester resin, and has a good heat-of-melt stability, mechanical properties, appearance, and a resin composition having a low coefficient of linear expansion, such as an inorganic filler such as polycarbonate resin, polytrimethylene terephthalate resin, graphite, and the like. A thermoplastic resin composition comprising an organic phosphate ester (see, for example, Patent Document 6) or a resin composition flame-retardant using graphite and not using a non-halogen or phosphorous flame retardant (see, for example, Patent Document 7). .) Is also proposed

JP-A-6-207083 Japanese Patent Laid-Open No. 2000-143958 JP 2001-060413 A Japanese Patent Laid-Open No. 2002-235010 JP 2006-249290 A JP 2004-352823 A JP 2006-273931 A

  However, in any of the resin compositions, it is difficult to obtain a resin molded product in which mechanical strength reduction, yellowing, and molecular weight reduction due to molecular weight reduction are suppressed, and there is a problem that appearance deterioration due to surface roughening also occurs. .

  The problem to be solved by the present invention is to solve all the above-mentioned problems of the prior art and to combine excellent conductivity, mechanical strength, heat resistance, flame retardancy, fusion heat stability and good appearance at the same time. The object is to provide a plastic resin composition.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have determined that the thermoplastic resin during the melting and kneading of the resin composition is particularly polycarbonate because of impurities such as moisture contained in the graphite in the resin composition. It has been found that the resin and the polyester resin are decomposed, resulting in a decrease in mechanical strength due to a decrease in molecular weight.

  And by blending graphite with low moisture content into polyester resin, it has excellent electrical conductivity, mechanical strength, heat resistance, flame retardancy, and melt heat stability, and becomes a thermoplastic resin with good surface properties. It discovered that it became a resin composition, and completed this invention.

  That is, the gist of the present invention is a thermoplastic resin composition comprising 50 to 95% by weight of a polycarbonate resin (A1) and / or a polyester resin (A2) and 50 to 5% by weight of graphite (B). A thermoplastic resin composition comprising (A1) and / or a polyester-based resin (A2) and graphite (B) having a moisture content of 0.2% or less, and a resin formed by molding the same It relates to a molded body.

  The thermoplastic resin composition of the present invention has excellent electrical conductivity, mechanical strength, heat resistance, flame retardancy, and melt heat stability, and can provide a resin molded product with good surface properties. Electronic / OA equipment parts, machine parts, vehicle exterior / skin parts, vehicle interior parts, building materials, various containers, recreational goods / miscellaneous goods, mobile phones, notebook computers, video cameras, copiers, facsimiles, etc. It can be used in a wide range of applications from minute parts to housings for various purposes.

  Hereinafter, the contents of the present invention will be described in detail. The polycarbonate resin (A1) used in the present invention is, for example, a linear or branched thermoplastic fragrance formed by reacting an aromatic dihydroxy compound and a carbonate precursor, or a small amount of a polyhydroxy compound or the like in combination therewith. Group polycarbonate resin or copolymer.

  The manufacturing method of polycarbonate resin (A1) used for this invention is not specifically limited, Conventionally well-known arbitrary manufacturing methods can be used. Specific examples of the production method include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring-opening polymerization method of a cyclic carbonate compound, and a solid phase transesterification method of a prepolymer.

  Specific examples of the aromatic dihydroxy compound used as a raw material include 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A) and 2,2-bis (3,5-dibromo-4-hydroxy). Phenyl) propane (= tetrabromobisphenol A), bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2,2- Bis (4-hydroxyphenyl) octane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (3-tert-butyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (3-bromo-4-hydroxyphenyl) propyl Bread, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (3-cyclohexyl-4-) Hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (4-hydroxyphenyl) -1,1,1-tri Chloropropane, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexachloropropane, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3 Bis (hydroxyaryl) alkanes exemplified by 3-hexafluoropropane and the like;

Exemplified by 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, etc. Bis (hydroxyaryl) cycloalkanes; cardostructure-containing bisphenols exemplified by 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene and the like ;

Dihydroxy diaryl ethers exemplified by 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether and the like; 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxy-3, Dihydroxydiaryl sulfides exemplified by 3′-dimethyldiphenyl sulfide; dihydroxydiaryl sulfoxides exemplified by 4,4′-dihydroxydiphenyl sulfoxide, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfoxide and the like; Dihydroxydiaryl sulfones exemplified by 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone, etc .; hydroquinone, resorcin, 4,4′-dihydroxy Diphenyl, and the like.

  Among these, bis (4-hydroxyphenyl) alkanes are preferably used, and in particular, 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A) from the viewpoint of impact resistance of the obtained polycarbonate resin. Is preferred. The aromatic dihydroxy compound which is a raw material of the polycarbonate resin (A) may be used alone or in combination of two or more in any ratio.

  As the carbonate precursor to be reacted with the aromatic dihydroxy compound, carbonyl halide, carbonate ester, haloformate, etc. are used. Specifically, phosgene; diaryl carbonates such as diphenyl carbonate, ditolyl carbonate; dimethyl carbonate, diethyl carbonate, etc. Dialkyl carbonates; dihaloformates of dihydric phenols and the like. These carbonate precursors may also be used alone or in combination of two or more.

  The polycarbonate resin (A1) may have a branched structure, and specifically, for example, a polycarbonate resin having a branched structure produced by a melt transesterification method, a straight chain produced by an interfacial polymerization method, or the like. Examples thereof include branched aromatic polycarbonate resins obtained by copolymerizing a polyfunctional aromatic compound having three or more functionalities with a polycarbonate resin.

  Examples of the trifunctional or higher polyfunctional aromatic compound include phloroglucin, 4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-2, 4,6-dimethyl-2,4,6- Tri (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-3, 1,3,5-tri (4-hydroxyphenyl) benzene, 1, Polyhydroxy compounds exemplified by 1,1-tri (4-hydroxyphenyl) ethane, etc., or 3,3-bis (4-hydroxyaryl) oxindole (isatin bisphenol), 5-chloroisatin, 5,7 -Dichloro isatin, 5-bromo isatin and the like.

  Among these, 1,1,1-tri (4-hydroxyphenyl) ethane is preferable. The polyfunctional aromatic compound can be used by substituting a part of the above-mentioned aromatic dihydroxy compound, and the amount used is preferably in the range of 0.01 to 10 mol% with respect to the aromatic dihydroxy compound, The range of 0.1-2 mol% is more preferable.

  Next, as a method for producing the polycarbonate resin (A1), an interfacial polymerization method and a melt transesterification method will be described. The reaction by the interfacial polymerization method is usually carried out in the presence of an organic solvent inert to the reaction and an aqueous alkali solution while maintaining the pH at 9 or higher. The reaction is carried out by reacting an aromatic dihydroxy compound with an optional molecular weight modifier (end-stopper) and an antioxidant for antioxidant oxidation with phosgene, followed by a tertiary amine or a secondary amine. A polycarbonate is obtained by adding a polymerization catalyst such as a quaternary ammonium salt and performing interfacial polymerization. The addition of the molecular weight regulator is not particularly limited as long as it is from the time of phosgenation to the start of the polymerization reaction. The reaction temperature is, for example, 0 to 40 ° C., and the reaction time is, for example, several minutes (for example, 10 minutes) to several hours (for example, 6 hours).

  Examples of the organic solvent inert to the reaction include chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, monochlorobenzene and dichlorobenzene, and aromatic hydrocarbons such as benzene, toluene and xylene. Examples of the alkali compound used in the alkaline aqueous solution include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide.

  Examples of the molecular weight regulator include compounds having a monovalent phenolic hydroxyl group. Specifically, for example, m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol, p-tert-butylphenol and and p-long chain alkyl-substituted phenols. The amount of the molecular weight regulator used is preferably 50 to 0.5 mol, more preferably 30 to 1 mol, per 100 mol of the aromatic dihydroxy compound.

  Polymerization catalysts include tertiary amines such as trimethylamine, triethylamine, tributylamine, tripropylamine, trihexylamine and pyridine: quaternary ammonium salts such as trimethylbenzylammonium chloride, tetramethylammonium chloride, triethylbenzylammonium chloride Etc.

  The reaction by the melt transesterification method is specifically, for example, a transesterification reaction between a carbonic acid diester and an aromatic dihydroxy compound. Examples of the carbonic acid diester include dialkyl carbonate compounds such as dimethyl carbonate, diethyl carbonate and di-tert-butyl carbonate, substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate, etc. Among them, diphenyl carbonate or substituted diphenyl carbonate is particularly preferable. Diphenyl carbonate is preferred.

  Adjustment of the molecular weight and terminal hydroxyl group amount in the melt transesterification method is generally performed by adjusting the mixing ratio of the carbonic acid diester and the aromatic dihydroxy compound, or adjusting the degree of pressure reduction during the reaction. As a more aggressive method, there may be mentioned an adjustment method in which a terminal terminator is added separately during the reaction. Examples of the terminal terminator include monohydric phenols, monovalent carboxylic acids, and carbonic acid diesters. The amount of terminal hydroxyl groups greatly affects the thermal stability, hydrolysis stability, color tone, etc. of the product polycarbonate. Although depending on the application, in order to have practical physical properties, it is preferably 1000 ppm or less, particularly preferably 700 ppm or less.

  Moreover, when manufacturing polycarbonate resin (A1) by a melt transesterification method, it is preferable that the amount of terminal hydroxyl groups of polycarbonate resin (A1) is 100 ppm or more. By setting it as the amount of such terminal hydroxyl groups, the fall of molecular weight can be suppressed and a color tone can also be made more favorable.

  In order to obtain such a polycarbonate resin (A1), specifically, for example, in the melt transesterification method, the carbonate diester is used in an equimolar amount or more with respect to 1 mol of the aromatic dihydroxy compound as a raw material. Among them, 1.01-1.30 mol is preferable.

  In the melt transesterification method, a transesterification catalyst is usually used. Although there is no restriction | limiting in particular as a transesterification catalyst, Specifically, an alkali metal compound and / or an alkaline-earth metal compound are preferable, for example. In addition, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound may be used in combination. In addition, it is preferable to deactivate these catalysts after completion of the polymerization.

  The reaction conditions in the melt shell exchange method are arbitrary and may be appropriately selected and determined. Specifically, for example, the reaction is performed at a temperature of 100 to 320 ° C., and finally, the reaction is performed under a reduced pressure of 2 mmHg or less. And a method in which a melt polycondensation reaction is performed while removing by-products such as a group hydroxy compound.

  The melt swell exchange method can be carried out batchwise or continuously, but is preferably carried out continuously in view of the stability of the resin composition of the present invention. Further, as a catalyst deactivator used in the melt shell exchange method, it is preferable to use a compound that neutralizes the catalyst, for example, a sulfur-containing acidic compound or a derivative formed therefrom. The compound that neutralizes such a catalyst is preferably added in an amount of 0.5 to 10 equivalents, more preferably 1 to 5 equivalents, relative to the alkali metal contained in the catalyst. In addition, the compound that neutralizes such a catalyst is preferably 1 to 100 ppm, particularly preferably 1 to 20 ppm, based on the polycarbonate.

  As for the molecular weight of polycarbonate resin (A1) used by this invention, the viscosity average molecular weight [Mv] converted from solution viscosity is 15000-30000 normally. If the viscosity average molecular weight is too low, the mechanical strength is too low. On the other hand, if the viscosity average molecular weight is too high, the fluidity is lowered and the molding process becomes difficult.

  Accordingly, the viscosity average molecular weight is preferably 17000 to 27000, particularly 19000 to 25000. As the polycarbonate resin (A1) used in the present invention, two or more kinds of aromatic polycarbonate resins having different viscosity average molecular weights may be mixed to fall within the above-mentioned viscosity average molecular weight range. A polycarbonate resin that is outside the preferred range may be used.

Here, the viscosity average molecular weight [Mv] is obtained by using methylene chloride as a solvent and obtaining an intrinsic viscosity [η] (unit: dl / g) at a temperature of 20 ° C. using an Ubbelohde viscometer. , Η = 1.23 × 10 ⁻⁴ M ^0.83 . Here, the intrinsic viscosity [η] is a value calculated from the following equation by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g / dl).

  Furthermore, as the polycarbonate resin (A1) used in the present invention, not only a virgin raw material but also a polycarbonate resin regenerated from a used product, so-called material recycled may be used. Used products include optical recording media such as optical discs, light guide plates, vehicle window glass, automotive headlamp lenses, windshields, and other vehicle transparent members, water bottle containers, glasses lenses, soundproof walls, glass windows, corrugated plates, etc. Preferred examples include building materials such as Also, non-conforming products, pulverized products obtained from sprues, runners, etc., or pellets obtained by melting them can be used. The recycled polycarbonate resin is preferably 80% by weight or less of (A1), more preferably 50% by weight or less.

  The polyester-based resin (A2) used in the present invention is a thermoplastic resin composed of a repeating unit whose main chain contains an ester bond. Specifically, for example, an aromatic polyester resin (A2-1), a liquid crystalline polyester resin. (A2-2), polyarylate resin (A2-3), and the like. Below, these (A2-1)-(A2-3) are demonstrated as an example as polyester-type resin (A2) used for this invention.

  The aromatic polyester resin (A2-1) used in the present invention is a thermoplastic polyester having an aromatic ring in a polymer chain unit, and an aromatic dicarboxylic acid (or its ester-forming derivative) and a diol (or its ester formation). Polymer or copolymer obtained by a condensation reaction mainly comprising a functional derivative).

  Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 4,4 ′. -Biphenyl dicarboxylic acid, 3,3'-biphenyl dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenyl sulfone dicarboxylic acid, 4,4'-diphenylisopropylidene Dicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4′-dicarboxylic acid, 2,5-anthracene dicarboxylic acid, 2,6-anthracene dicarboxylic acid, 4,4 ″ -p-terphenylenedicarboxylic acid 2,5-pyridinedicarboxylic acid, etc. Among them, terephthalic acid is preferred. .

  These aromatic dicarboxylic acids may be used as a mixture of two or more. In a small amount, these aromatic dicarboxylic acids and aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid and dodecanedioic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, or p-oxybenzoic acid One or more of such oxycarboxylic acids can be used in combination.

  Examples of the diol component include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, decamethylene glycol, 2-methyl-1,3-propanediol, diethylene glycol, triethylene glycol and other aliphatic diols, Examples thereof include alicyclic diols such as 1,4-cyclohexanedimethanol, and mixtures thereof. If the amount is small, one or more kinds of long chain diols having a molecular weight of 400 to 6,000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, and the like may be copolymerized.

  Specific examples of the aromatic polyester resin (A2-1) used in the present invention include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyhexylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene-1, and the like. 2-bis (phenoxy) ethane-4,4′-dicarboxylate and the like, and copolymers thereof such as polyethylene isophthalate / terephthalate, polybutylene phthalate / isophthalate, polybutylene terephthalate / decanedicarboxy Rate and the like.

  Among them, as the aromatic polyester resin (A2-1) used in the present invention, polybutylene terephthalate and polyethylene terephthalate having a good balance of mechanical properties, moldability and the like are preferable.

  The aromatic polyester resin (A2-1) used in the present invention has an intrinsic viscosity [η measured at 30 ° C. in a 5 to 5 (weight ratio) mixed solvent of phenol and 1,1,2,2-tetrachloroethane. ] Is preferably 0.6 to 1.5 dl / g.

  The liquid crystalline polyester resin (A2-2) used in the present invention is a polyester resin called a thermotropic liquid crystalline polymer, and is composed of a combination of (1) aromatic dicarboxylic acid, aromatic diol and aromatic hydroxycarboxylic acid. (2) those composed of different kinds of aromatic hydroxycarboxylic acids, (3) those composed of combinations of aromatic dicarboxylic acids and aromatic diols, and (4) polyesters such as polyethylene terephthalate are reacted with aromatic hydroxycarboxylic acids. An anisotropic melt is formed at a temperature of 400 ° C. or lower.

  In addition, these ester-forming derivatives may be used in place of these aromatic dicarboxylic acids, aromatic diols and aromatic hydroxycarboxylic acids.

  Specific examples of the liquid crystalline polyester resin (A2-2) used in the present invention include, for example, JP-B-47-47870, JP-B-63-3888, JP-B-63-3891, and JP-B-56- Any conventionally known one described in Japanese Patent No. 18016 can be used. Moreover, the manufacturing method of these liquid crystalline polyester resins (A2-2) is also arbitrary, and any conventionally known method may be applied.

  Specific examples of the commercially available liquid crystalline polyester resin (A2-2) include Eastman Kotak's X7G, Dartco's Xyday, Sumitomo Chemical's Econol, Celanese's Vectra, and the like.

  The polyarylate resin (A2-3) used in the present invention comprises an aromatic dicarboxylic acid or a derivative thereof and a bisphenol or a derivative thereof. Preferred aromatic dicarboxylic acids are isophthalic acid, terephthalic acid, orthophthalic acid, etc., but using a mixture of 9/1 to 1/9 (weight ratio) of isophthalic acid and terephthalic acid is particularly preferable in terms of workability. Is preferred.

  Examples of bisphenols include 2,2-bis (4-hydroxyphenyl) propane, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, 4,4′-dihydroxy-3,3′-dichlorodiphenyl ether, 4, 4′-dihydroxy-diphenyl sulfide, 4,4′-dihydroxy-diphenyl sulfone, 4,4′-dihydroxy-diphenyl ketone, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) n-butane, di- (4-hydroxyphenyl) -cyclohexylmethane, 1,1-bis (4-hydroxyphenyl) -2,2,2-trichloroethane and the like can be mentioned. . Of these, 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A) is preferable.

  The production method of the polyarylate resin (A2-3) used in the present invention is arbitrary, and specific examples include various methods such as solution polymerization, melt polymerization, and interfacial polymerization. The intrinsic viscosity of the polyarylate resin (A2-3) used in the present invention is usually 0.4 to 1.2 dl / g as measured at 30 ° C. in a mixed solvent of phenol / tetrachloroethane (weight ratio 1/1). It is. Specific examples of the commercially available polyarylate resin (A2-3) include U polymer manufactured by Unitika Ltd.

  The graphite (B) used in the present invention is characterized by having a moisture content of 0.2% or less. If the water content is too high, the resin is promoted to be decomposed by melt-kneading with the polycarbonate resin (A1) or the polyester-based resin (A2), resulting in a decrease in molecular weight and a decrease in mechanical strength of the resin molded body, resulting in yellowing. Further, the appearance may be deteriorated due to rough surface.

  The shape of the graphite (B) used in the present invention is arbitrary and may be determined by appropriately selecting from any conventionally known ones. Specifically, for example, natural scale-like graphite, natural earth-like graphite, artificial Examples thereof include graphite. These may be used alone or in combination of two or more in any ratio.

  The graphite (B) used in the present invention further has an average particle size of 50 μm or less, and the content of graphite particles having a particle size of 50 μm or more in the total graphite particle amount is 50% or less (relative particle amount of 50% or less). Preferably there is. The average particle diameter may be appropriately selected and determined as long as it is 50 μm or less, but usually the lower limit is 1 μm.

  If the average particle size of the graphite (B) is too large, or if the relative particle amount of the particle size of 50 μm or more is too large, the dispersibility of the graphite particles may be lowered, and the appearance of the resulting resin molded product may be lowered. Therefore, the graphite (B) used in the present invention preferably has an average particle size of 40 μm or less, more preferably 30 μm or less, and particularly preferably 25 μm or less.

  Conversely, when the mixed material is fed to the kneader even if the average particle size is too small, the graphite (B) may not be stably fed due to aggregation of the graphite particles. It is preferably 3 μm or more, particularly 5 μm or more. In addition, it is preferable that the relative particle amount of graphite particles having a particle size of 50 μm or more is as small as possible. In particular, it is preferably 40% or less, more preferably 30% or less, and particularly preferably 20% or less.

  The aspect ratio of graphite (B) used in the present invention is preferably more than 3 and 50 or less. If this aspect ratio is too small, the effect of improving the electrical conductivity of the resin molded product may be reduced. Conversely, if it is too large, the conductivity, mechanical strength, and anisotropy of the molding shrinkage ratio will become significant. It is not preferable.

  The relative particle amount of graphite (B) in the present invention indicates the ratio of graphite particles having respective particle diameters (ranges) when the number of measured particles is 100%, and the measurement method is usually laser diffraction. It can be measured by an equation distribution measuring device. The aspect ratio indicates the ratio (major axis / minor axis) of the major axis length (major axis) and the minor axis length (minor axis) of graphite (B). The aspect ratio of the graphite (B) used in the present invention is determined by dispersing graphite in a solvent and then dispersing the graphite with a scanning electron microscope (500 times magnification) (photographing range is 250 μm × 250 μm square). ), The major axis and the minor axis were measured for 40 to 50 graphite particle images randomly from this photograph, the ratio was determined, and the average value of the whole was taken as the aspect ratio.

  Further, the graphite (B) used in the present invention preferably has a higher carbon purity, specifically 95% or more, particularly 98% or more. If the carbon purity of graphite is too low, the resin will decompose during melt-kneading with the resin component and the molecular weight will decrease significantly, not only the mechanical strength but also the flame retardancy and the appearance of the resin molding will be reduced. There is. In addition, the graphite (B) used in the present invention is preferably subjected to a surface treatment in order to improve the affinity with the resin component as long as the effects of the present invention are not impaired. Specific examples of such surface treatment include epoxy treatment, urethane treatment, oxidation treatment, and the like.

  The blending amount of the graphite (B) in the thermoplastic resin composition of the present invention is the polycarbonate resin (A1) and / or the polyester resin (A2) (hereinafter, these may be collectively referred to as “component (A)”. ) And graphite (B) (hereinafter sometimes referred to as “component (B)”), the amount is 5 to 50% by weight when the mixture is 100% by weight. If the blending amount of graphite (B) is less than 5% by weight, the electrical conductivity and flame retardancy are insufficient. Conversely, if it exceeds 50% by weight, the impact resistance and fluidity are insufficient.

  The thermoplastic resin composition of the present invention is not limited to the purpose of the present invention, if necessary, in addition to the components (A) and (B), and other resins, impact resistance improvers, and various resin additives. An agent, an inorganic filler, etc. can be mix | blended.

  Examples of other resins include polyolefin resins such as polyethylene resins and polypropylene resins, polystyrene resins, polyamide resins, polyimide resins, polyetherimide resins, polyurethane resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, polymethacrylates. Resin etc. are mentioned.

  Examples of impact modifiers include styrene-butadiene block copolymers, hydrogenated styrene-butadiene block copolymers in which part or all of the butadiene portion is hydrogenated, styrene-isoprene block copolymers, and hydrogenated styrene. -Isoprene block copolymers, ethylene propylene elastomers, thermoplastic polyester elastomers, thermoplastic polyamide elastomers, core-shell polymers having a rubbery core, and the like. Examples of the core-shell polymer having a rubber-like core include butadiene-based rubber and acrylate-based rubber as the core polymer, and examples of the shell polymer include meth- acrylate-based polymer and styrene-based polymer. .

  Resin additives include phosphorus stabilizers, phenolic stabilizers, flame retardants, anti-dripping agents, mold release agents, dyes and pigments, antistatic agents, anti-fogging agents, lubricants / anti-blocking agents, fluidity improvers, plastics Agents, dispersants, antibacterial agents and the like.

  Examples of the inorganic filler include glass fiber, glass milled fiber, glass flake, glass bead, carbon fiber, silica, alumina, titanium oxide, calcium sulfate powder, gypsum, gypsum whisker, barium sulfate, talc, mica, calcium silicate, Carbon black, graphite, iron powder, copper powder, molybdenum disulfide, silicon carbide, silicon carbide fiber, silicon nitride, silicon nitride fiber, brass fiber, stainless steel fiber, potassium titanate fiber or whisker. These can be used alone or in combination of two or more.

  Any conventionally known fluoropolymer can be used as the anti-drip agent. Specific examples include polytetrafluoroethylene (PTFE).

  The thermoplastic resin composition of the present invention can be produced by a known method for producing a thermoplastic resin composition. Specifically, for example, the above-mentioned component (A), component (B), and additive components blended as necessary are mixed in advance using various mixers such as a tumbler and a Henschel mixer, What is necessary is just to melt-knead with a mixer, a roll, a brabender, a single screw kneading extruder, a twin screw kneading extruder, a kneader or the like.

  Further, each component may be mixed in advance without being mixed in advance, or only a part of the components may be mixed in advance and supplied to an extruder using a feeder. Furthermore, when blending components that are susceptible to changes due to heat, shearing force, etc., during melt-kneading, other components are added all at once from the upstream portion of the extruder, and components that are subject to change after the middle stream are added. A method of melt kneading with the resin component is preferable.

  The resin molded body of the present invention can be obtained by using and molding the above-described thermoplastic resin composition of the present invention as a resin material for production (molding) of various products (molded products). The molding method may be appropriately selected and determined from any conventionally known resin molding method.

  Specifically, for example, a general injection molding method, an ultra-high speed injection molding method, an injection compression molding method, a two-color molding method, a hollow molding method such as gas assist, a molding method using a heat insulating mold, a rapid heating mold Molding method, foam molding (including supercritical fluid), insert molding, in-mold coating (IMC) molding method, extrusion molding method, film molding method, sheet molding method, thermoforming method, rotational molding method, laminate molding Method, press molding method and the like. Among these, the injection molding method is preferable from the viewpoint of the degree of freedom of shape and mass productivity of the resin molded body.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In addition, the compounding quantity of each raw material in a following example and a comparative example shows a weight part. Each raw material used in Examples and Comparative Examples is as follows.

<Component A> Polycarbonate: Iupilon S-3000F Mv21000 manufactured by Mitsubishi Gas Chemical Company, Inc.

<Component B> Graphite: The one shown in Table 1 below was used. The moisture content was measured using a Karl Fischer moisture meter (Mitsubishi Chemical Corporation; moisture meter CA-100) at a temperature of 280 ° C.

<C component> Flame retardant: Metal salt flame retardant perfluorobutanesulfonic acid potassium salt RM65 manufactured by MITENI

<Component D> Anti-dripping agent: Polytetrafluoroethylene (PTFE) Teflon (registered trademark) 6J manufactured by DuPont

<E component> Mold release agent: Pentaerythritol tetrastearate VPG861 manufactured by Cocnis Japan

<F component> Stabilizer: Phosphorus stabilizer AX71 manufactured by Asahi Denka Kogyo Co., Ltd.

(Examples 1-7, Comparative Examples 1-6)
[Pellet making]
After uniformly mixing the resin compositions blended in the components and proportions shown in Tables 1 and 2 with a tumbler mixer, using a twin screw extruder (30 mmφ) having two feed ports, the cylinder temperature is 260 ° C. The resin composition and the plate-like filler were fed from the main hopper into the kneader and melted and kneaded to produce pellets.

[Mechanical properties evaluation]
An ISO multi-purpose test piece is manufactured from the obtained pellets using an injection molding machine (Sumitomo Heavy Industries, Ltd., Psycap M-2, clamping force 75T) under conditions of a cylinder temperature of 280 ° C. and a mold temperature of 110 ° C. The flexural modulus FM (measured by a three-point bending test by the ISO 178 bending test method) and the Charpy impact strength CI (measured in a non-notch by ISO 179. In addition, the case where the test machine capacity is 50J is not marked as NB. ) Was measured. The results are shown in Tables 1 and 2.

[Thermal stability evaluation]
In the above-described molding, the viscosity average molecular weight was measured for two resin molded bodies with a molding cycle of 49 seconds and 180 seconds. Tables 1 and 2 show the results with a molding cycle of 49 seconds as “normal” and 180 seconds as “residence”.

[Flammability evaluation]
Using an injection molding machine (J50-EP mold clamping force 50T manufactured by Nippon Steel Works), the obtained pellets were subjected to a UL combustion test piece having a thickness of 1.6 mm under conditions of a cylinder temperature of 280 ° C. and a mold temperature of 110 ° C. Molded and tested for UL94. The results are shown in Tables 1 and 2.

[Measurement of surface resistance]
The obtained pellets are molded into a 3 mm thick, 100 mm square plate using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., SH100, mold clamping 100T). The surface resistance was measured using R8349, R12704 manufactured by Advantest Corporation. The results are shown in Tables 1 and 2.

  From Examples 1-6, it turns out that the thermoplastic resin composition of this invention has the outstanding electroconductivity, mechanical strength, thermal stability, and a flame retardance. And from the outstanding electroconductivity, electromagnetic shielding properties can be expected. In any resin molding, the surface property was good. And Example 7 shows that V-1 becomes V-0 only by slightly increasing the amount of the flame retardant, and the flame retardancy is remarkably improved.

  When Examples 1 to 3 and Comparative Examples 1 and 2 are compared, it can be seen that when the blending amount of graphite exceeds the range of the present invention, flame retardancy is lowered, and further, pelletization by extrusion becomes difficult. And when Examples 1-7 and Comparative Examples 3-6 are compared, if the moisture content of the graphite to be blended is too high beyond the range of the present invention, sufficient thermal stability cannot be obtained and the molecular weight is remarkably reduced. I understand that

Claims (5)

  A thermoplastic resin composition comprising 50 to 95% by weight of a polycarbonate resin (A1) and / or polyester resin (A2) and 50 to 5% by weight of graphite (B), wherein the polycarbonate resin (A1) and / or polyester A thermoplastic resin composition, comprising a resin (A2) and graphite (B) having a moisture content of 0.2% or less.   2. The thermoplastic resin composition according to claim 1, wherein the graphite (B) has an average particle size of 50 μm or less, and the content of graphite particles having a particle size of 50 μm or more is 50% or less of the total amount of graphite particles.   The thermoplastic resin composition according to claim 1 or 2, wherein the aspect ratio of graphite (B) is more than 3 and 50 or less.   The thermoplastic resin composition according to any one of claims 1 to 3, wherein the carbon purity of the graphite (B) is 95% or more.   The resin molding formed by shape | molding the thermoplastic resin composition in any one of Claims 1 thru | or 4.