JP6252146B2 - Carbon fiber reinforced thermoplastic resin composition, pellets formed from the same, and thin molded article - Google Patents

Description

  The present invention relates to a carbon fiber reinforced thermoplastic resin composition, pellets formed by molding the same, and a thin-walled molded article.

  BACKGROUND ART A thermoplastic resin composition reinforced with a fibrous filler such as glass fiber or carbon fiber is widely used because it is excellent in mechanical strength and workability. In particular, aromatic polycarbonate resin has excellent properties such as mechanical strength, dimensional stability, and flame retardancy, so it is used in many applications such as machine parts, automobile parts, electrical / electronic parts, and office equipment parts. Yes. On the other hand, a resin composition in which a fibrous filler such as glass fiber or carbon fiber is blended with an aromatic polycarbonate resin is excellent in rigidity and mechanical strength, but its fluidity decreases, so the injection molding temperature is set to a high temperature. In some cases, it is difficult to obtain a thin molded product. In addition, when injection molding is performed using a multi-point gate mold in order to obtain a thin molded product, there is a problem that the strength of the weld portion is remarkably reduced. Aromatic polycarbonate not only has rigidity and mechanical strength, but also has good fluidity and weld strength during molding when used in precision machine parts such as housings for digital cameras and the like, lens barrel parts, and office equipment parts. There is a need for resin compositions.

  As a thermoplastic resin composition having excellent rigidity and mechanical properties and good surface appearance of a molded article, an aromatic polycarbonate resin, a thermoplastic aromatic polyester resin, a filler, a hydroxyl-containing polymer and a polylactone are blended. A fiber reinforced resin composition has been proposed (see, for example, Patent Document 1). In addition, as a thermoplastic resin composition having a low linear expansion coefficient, high rigidity, and good surface appearance, a resin composition comprising an aromatic polycarbonate resin, an aromatic polyester resin, talc, and carbon fiber has been proposed. (For example, refer to Patent Document 2).

JP 7-242809 A JP 2010-275449 A

  In the resin compositions described in Patent Documents 1 and 2, the rigidity is improved by using carbon fibers, but the flexural modulus is insufficient for use in applications where high rigidity is required. Is a level. On the other hand, in order to improve the rigidity, for example, it is considered effective to increase the blending amount of carbon fiber, but it is obtained when the blending amount of carbon fiber is greatly increased in the techniques described in Patent Documents 1 and 2. A particularly remarkable problem occurs in the carbon fiber reinforced thermoplastic resin composition that the weld strength and fluidity of the resin composition are lowered.

  The present invention relates to a carbon fiber reinforced thermoplastic resin composition having excellent fluidity, high rigidity and tensile strength, and capable of obtaining a molded product with improved weld strength, pellets formed by molding the same, and thin-wall molding The issue is to provide goods.

In order to solve the above problems, the carbon fiber reinforced thermoplastic resin composition of the present invention has the following constitution.
(1) A resin composition comprising (A) an aromatic polycarbonate resin, (B) a thermoplastic polyester resin, (C) carbon fiber, (D) an alkoxysilane compound having an isocyanate group and / or an epoxy group. The total blending amount of (A) aromatic polycarbonate resin and (B) thermoplastic polyester resin is 100% by weight, and (A) aromatic polycarbonate resin blending amount is 1 to 99% by weight, (B) thermoplastic polyester resin The blending amount is 99 to 1% by weight, the total blending amount of (A) aromatic polycarbonate resin and (B) thermoplastic polyester resin is 100 parts by weight, and (C) the carbon fiber blending amount is 25 to 100 parts by weight, (D) Carbon fiber containing 0.01 to 2 parts by weight of an alkoxysilane compound having an isocyanate group and / or an epoxy group Reinforced thermoplastic resin composition,
(2) The carbon fiber reinforced thermoplastic resin composition according to (1), wherein the (B) thermoplastic polyester resin contains an aromatic polyester resin,
(3) The carbon fiber reinforced thermoplastic resin composition according to (1) or (2), wherein (B) the thermoplastic polyester resin contains polybutylene terephthalate,
(4) (D) The carbon fiber reinforced thermoplastic resin composition according to any one of (1) to (3), wherein the alkoxysilane compound having an isocyanate group and / or an epoxy group has an isocyanate group,
(5) The total amount of (A) aromatic polycarbonate resin and (B) thermoplastic polyester resin is 100 parts by weight, and (E) 0.01 to 5 parts by weight of a compound having three or more hydroxyl groups is blended. The carbon fiber reinforced resin composition according to any one of (1) to (4),
(6) A pellet formed by molding the carbon fiber reinforced thermoplastic resin composition according to any one of (1) to (5), wherein the weight average fiber length of the carbon fiber in the pellet is 0.01 to 2 mm. Pellet, which is
(7) A thin molded product obtained by molding the pellet according to (6),
(8) The thin molded article according to (7), which is a casing or a part of an electric / electronic device having a weld portion.

  The carbon fiber reinforced thermoplastic resin composition of the present invention is excellent in fluidity. Furthermore, according to the carbon fiber reinforced thermoplastic resin composition of the present invention, a molded article having high rigidity and tensile strength and improved weld strength can be obtained.

  The carbon fiber reinforced thermoplastic resin composition of the present invention, its pellets and molded products will be specifically described below. The carbon fiber reinforced thermoplastic resin composition of the present invention (hereinafter sometimes referred to as “resin composition”) includes: (A) an aromatic polycarbonate resin, (B) a thermoplastic polyester resin, (C) a carbon fiber, (D) An alkoxysilane compound having an isocyanate group and / or an epoxy group is blended.

  The (A) aromatic polycarbonate resin used in the present invention is a linear or branched aromatic polycarbonate polymer or copolymer. (A) By mix | blending an aromatic polycarbonate resin, characteristics, such as impact resistance and dimensional stability, can be provided to the molded article obtained from a resin composition.

  The (A) aromatic polycarbonate resin used in the present invention can be easily obtained, for example, by reacting an aromatic dihydroxy compound with a carbonate precursor such as phosgene or carbonic acid diester. A known method is used as the reaction method, and examples thereof include an interfacial polymerization method, a melt transesterification method, a solid phase transesterification method of a carbonate prepolymer, and a ring-opening polymerization method of a cyclic carbonate compound.

  A representative example of the aromatic dihydroxy compound is 2,2-bis (4-hydroxyphenyl) propane [bisphenol A]. Other examples include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, and 2,2-bis (4-hydroxyphenyl). Octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-tert-butylphenyl) propane, 2, 2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) Bis (hydroxyaryl) alkanes such as propane; 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis ( Bis (hydroxyaryl) cycloalkanes such as hydroxyphenyl) cyclohexane; Dihydroxydiaryl ethers such as 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether; 4,4′- Dihydroxydiaryl sulfides such as dihydroxydiphenyl sulfide, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfide; 4,4′-dihydroxydiphenyl sulfoxide, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfoxide Dihydroxydiaryl sulfoxides such as 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone Emissions, and the like can be mentioned. Two or more of these may be used.

  Examples of the carbonate precursor to be reacted with the aromatic dihydroxy compound include phosgene and carbonic acid diester. Examples of the carbonic acid diester include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate, and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate.

  The (A) aromatic polycarbonate resin used in the present invention is a co-polymer of an aromatic dihydroxy compound, a carbonate precursor, and other compounds such as piperazine, dipiperidyl hydroquinone, resorcin, and 4,4′-dihydroxydiphenyls. It may be a coalescence. By copolymerizing a polyfunctional compound such as phloroglucin, a branched aromatic polycarbonate resin can be obtained.

  (A) The molecular weight of the aromatic 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, preferably 10,000 to 50,000, more preferably It is 15,000-40,000, Most preferably, it is 18,000-30,000.

  As a method for obtaining an aromatic polycarbonate resin having a desired molecular weight, for example, known methods such as a method using a terminal terminator or a molecular weight regulator, a method for selecting polymerization reaction conditions, and the like are employed.

  The (B) thermoplastic polyester resin used in the present invention includes (a) a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof, (b) a hydroxycarboxylic acid or an ester-forming derivative thereof and (c) ) A polymer or copolymer having a main structural unit of one or more residues selected from the group consisting of lactones. (B) The thermoplastic polyester resin has excellent fluidity compared to (A) aromatic polycarbonate resin, and (C) has excellent interfacial adhesiveness with carbon fiber. Therefore, by blending (B) thermoplastic polyester resin, The fluidity of the resin composition can be improved, and the tensile strength and weld strength of a molded product obtained from the resin composition can be improved.

  Examples of the dicarboxylic acid or ester-forming derivative thereof include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, and anthracene dicarboxylic acid. Acid, 4,4'-diphenyl ether dicarboxylic acid, 5-tetrabutylphosphonium isophthalic acid, aromatic dicarboxylic acid such as 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid And aliphatic dicarboxylic acids such as malonic acid, glutaric acid and dimer acid, alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, and ester-forming derivatives thereof. Two or more of these may be used.

  Examples of the diol or ester-forming derivative thereof include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol, C2-C20 aliphatic glycols such as cyclohexanedimethanol, cyclohexanediol and dimer diol, long chain glycols having a molecular weight of 200 to 100,000 such as polyethylene glycol, poly-1,3-propylene glycol and polytetramethylene glycol, 4, Aromatic dioxy compounds such as 4′-dihydroxybiphenyl, hydroquinone, t-butylhydroquinone, bisphenol A, bisphenol S, bisphenol F, and ester-forming derivatives thereof Etc., and the like. Two or more of these may be used.

  Examples of the polymer or copolymer having as structural units a residue of dicarboxylic acid or its ester-forming derivative and diol or its ester-forming derivative include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate. , Polyhexylene terephthalate, polyethylene isophthalate, polypropylene isophthalate, polybutylene isophthalate, polycyclohexanedimethylene isophthalate, polyhexylene isophthalate, polyethylene naphthalate, polypropylene naphthalate, polybutylene naphthalate, polyethylene isophthalate / terephthalate , Polypropylene isophthalate / terephthalate, polybutylene isophthalate / terephthalate Rate, polyethylene terephthalate / naphthalate, polypropylene terephthalate / naphthalate, polybutylene terephthalate / naphthalate, polybutylene terephthalate / decane dicarboxylate, polyethylene terephthalate / cyclohexanedimethylene terephthalate, polyethylene terephthalate / 5-sodium sulfoisophthalate, polypropylene terephthalate / 5- Sodium sulfoisophthalate, polybutylene terephthalate / 5-sodium sulfoisophthalate, polyethylene terephthalate / polyethylene glycol, polypropylene terephthalate / polyethylene glycol, polybutylene terephthalate / polyethylene glycol, polyethylene terephthalate / polytetramethylene glycol , Polypropylene terephthalate / polytetramethylene glycol, polybutylene terephthalate / polytetramethylene glycol, polyethylene terephthalate / isophthalate / polytetramethylene glycol, polypropylene terephthalate / isophthalate / polytetramethylene glycol, polybutylene terephthalate / isophthalate / polytetramethylene Glycol, polyethylene terephthalate / succinate, polypropylene terephthalate / succinate, polybutylene terephthalate / succinate, polyethylene terephthalate / adipate, polypropylene terephthalate / adipate, polybutylene terephthalate / adipate, polyethylene terephthalate / sebacate, polypropylene terephthalate / se Bactoate, polybutylene terephthalate / sebacate, polyethylene terephthalate / isophthalate / adipate, polypropylene terephthalate / isophthalate / adipate, polybutylene terephthalate / isophthalate / succinate, polybutylene terephthalate / isophthalate / adipate, polybutylene terephthalate / isophthalate / sebacate Aromatic polyester resins such as polyethylene oxalate, polypropylene oxalate, polybutylene oxalate, polyethylene succinate, polypropylene succinate, polybutylene succinate, polyethylene adipate, polypropylene adipate, polybutylene adipate, polyneopentyl glycol adipate, polyethylene Sebacate, PolyPro Rensebaketo, polybutylene sebacate, polyethylene succinate / adipate, polypropylene succinate / adipate, and aliphatic polyester resins such as polybutylene succinate / adipate and the like. Here, “/” indicates copolymerization. Two or more of these may be used.

  (B) terephthalic acid or its ester-forming derivative with respect to all dicarboxylic acids in the polymer or copolymer having the main structural unit as the residue of dicarboxylic acid or its ester-forming derivative and diol or its ester-forming derivative The proportion is preferably 30 mol% or more, more preferably 40 mol% or more.

  Examples of the (ro) hydroxycarboxylic acid or ester-forming derivative thereof include glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxybenzoic acid, p-hydroxybenzoic acid, Examples include 6-hydroxy-2-naphthoic acid and ester-forming derivatives thereof. Two or more of these may be used.

  Examples of the polymer or copolymer having a residue of hydroxycarboxylic acid or its ester-forming derivative as a structural unit include polyglycolic acid, polylactic acid, polyglycolic acid / lactic acid, polyhydroxybutyric acid / β-hydroxybutyric acid / Examples include aliphatic polyester resins such as β-hydroxyvaleric acid. Two or more of these may be used.

  Examples of the (c) lactone include caprolactone, valerolactone, propiolactone, undecalactone, 1,5-oxepan-2-one, and the like. Two or more of these may be used.

  (C) Examples of the polymer or copolymer having a lactone as a structural unit include polycaprolactone, polyvalerolactone, polypropiolactone, polycaprolactone / valerolactone, and the like. Two or more of these may be used.

  Among these, (a) a polymer or copolymer having a main structural unit as a residue of a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof is preferable, and an aromatic dicarboxylic acid or an ester thereof is formed. More preferred is a polymer or copolymer having a main structural unit as the residue of a functional derivative and an aliphatic diol or an ester-forming derivative thereof, selected from terephthalic acid or an ester-forming derivative thereof and ethylene glycol, propylene glycol, or butanediol. More preferred are polymers or copolymers having the main structural unit as the residue of the aliphatic diol or ester-forming derivative thereof. Among them, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate, polyethylene naphthalate, polypropylene naphthalate, polybutylene naphthalate, polyethylene isophthalate / terephthalate, polypropylene isophthalate / terephthalate, polybutylene isophthalate / terephthalate, Aromatic polyester resins such as polyethylene terephthalate / naphthalate, polypropylene terephthalate / naphthalate, and polybutylene terephthalate / naphthalate are particularly preferred, and the rigidity, tensile strength, and heat resistance of the molded product can be further improved. More preferred are polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, polyethylene naphthalate, and polycyclohexanedimethylene terephthalate. Polybutylene terephthalate is most preferable, and the rigidity, tensile strength, and weld strength of the molded product can be further improved.

  The carboxyl end group amount of the thermoplastic polyester resin (B) used in the present invention is preferably 50 eq / t or less, preferably 30 eq / t or less, in terms of fluidity, hydrolysis resistance and heat resistance. Is more preferably 20 eq / t or less, and particularly preferably 10 eq / t or less. The lower limit is 0 eq / t. In the present invention, the carboxyl end group amount of (B) the thermoplastic polyester resin is a value measured by dissolving in o-cresol / chloroform solvent and titrating with ethanolic potassium hydroxide.

  The amount of hydroxyl terminal groups of the thermoplastic polyester resin (B) used in the present invention is preferably 50 eq / t or more, more preferably 80 eq / t or more, in terms of moldability and fluidity, and 100 eq. / T or more is more preferable, and 120 eq / t or more is particularly preferable. On the other hand, the upper limit is preferably 180 eq / t or less.

  The viscosity of the (B) thermoplastic polyester resin used in the present invention is preferably in the range of 0.36 to 1.60 dl / g in terms of moldability, preferably 0.50 to 1.50 dl / g. The range of g is more preferable. In addition, the intrinsic viscosity of (B) thermoplastic polyester resin is the value which measured the o-chlorophenol solution at 25 degreeC.

  The molecular weight of the (B) thermoplastic polyester resin used in the present invention is preferably in the range of more than 8,000 to 500,000 in weight average molecular weight (Mw) in terms of heat resistance, and more than 30,000 to 300,000. More preferably, it is more preferably in the range of more than 8000 and not more than 250,000. In the present invention, Mw of the polyester resin is a value in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography (GPC) using hexafluoroisopropanol as a solvent.

  The (B) thermoplastic polyester resin used in the present invention can be produced by a known polycondensation method or ring-opening polymerization method. Either batch polymerization or continuous polymerization may be used, and any of transesterification and direct polymerization can be applied, but the amount of carboxyl end groups can be reduced and the effect of improving fluidity is increased. In view of this, continuous polymerization is preferable, and direct polymerization is preferable in terms of cost.

  When the thermoplastic polyester resin (B) used in the present invention is a polymer or copolymer obtained by a condensation reaction mainly comprising a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Can be produced by subjecting a dicarboxylic acid or its ester-forming derivative and a diol or its ester-forming derivative to an esterification reaction or a transesterification reaction, followed by a polycondensation reaction. In order to effectively advance the esterification reaction or transesterification reaction and polycondensation reaction, it is preferable to add a polycondensation reaction catalyst during these reactions. Specific examples of the polycondensation reaction catalyst include titanic acid methyl ester, tetra-n-propyl ester, tetra-n-butyl ester, tetraisopropyl ester, tetraisobutyl ester, tetra-tert-butyl ester, cyclohexyl ester, and phenyl ester. , Benzyl esters, tolyl esters, or mixed esters thereof, dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethylditin oxide, cyclohexahexylditin oxide, didodecyltin oxide, triethyltin hydro Oxide, triphenyltin hydroxide, triisobutyltin acetate, dibutyltin diacetate, diphenyltin dilaurate, monobutyltin trichloride Dibutyltin dichloride, tributyltin chloride, dibutyltin sulfide and butylhydroxytin oxide, tin compounds such as alkylstannic acid such as methylstannic acid, ethylstannic acid, butylstannic acid, zirconia compounds such as zirconium tetra-n-butoxide, And antimony compounds such as antimony trioxide and antimony acetate. Two or more of these may be used. Among these, an organic titanium compound and a tin compound are preferable, tetra-n-propyl ester, tetra-n-butyl ester and tetraisopropyl ester of titanic acid are more preferable, and tetra-n-butyl ester of titanic acid is particularly preferable. The addition amount of the polycondensation reaction catalyst is preferably in the range of 0.005 to 0.5 parts by weight with respect to 100 parts by weight of the (B) thermoplastic polyester resin in terms of mechanical properties, moldability and color tone. A range of 01 to 0.2 parts by weight is more preferable.

  The blending amount of (A) aromatic polycarbonate resin and (B) thermoplastic polyester resin in the resin composition of the present invention is 100% by weight of the total blending amount of (A) aromatic polycarbonate resin and (B) thermoplastic polyester resin. As for (A) aromatic polycarbonate resin compounding quantity, 1 to 99 weight%, (B) thermoplastic polyester resin compounding quantity is 1 to 99 weight%. (A) When the compounding quantity of aromatic polycarbonate resin is less than 1 weight%, the impact resistance of the molded article obtained from a resin composition and dimensional stability will fall. It is preferably 30% by weight or more, more preferably 50% by weight or more, and further preferably 60% by weight or more. On the other hand, if the blending amount of (A) aromatic polycarbonate resin exceeds 99% by weight, the blending amount of (B) thermoplastic polyester resin is relatively reduced, so that the fluidity of the resin composition, the rigidity of the molded product, Tensile strength and weld strength are reduced. It is preferably 95% by weight or less, more preferably 90% by weight or less, and still more preferably 85% by weight or less.

  The resin composition of the present invention comprises (C) carbon fiber. (C) By mix | blending carbon fiber, the rigidity and impact resistance of the molded article obtained from a resin composition can be improved. The carbon fiber (C) used in the present invention is not particularly limited, and is a carbonaceous fiber produced using various known carbon fibers such as polyacrylonitrile (PAN), pitch, rayon, lignin, hydrocarbon gas, and the like. And graphite fibers, and fibers obtained by coating these fibers with metal. Two or more of these may be used. Of these, PAN-based carbon fibers capable of improving mechanical properties can be preferably used.

  The carbon fiber (C) used in the present invention is not particularly limited, and examples thereof include chopped strands, roving strands, and milled fibers. The diameter is generally 15 μm or less, preferably 5 to 10 μm.

  The (C) carbon fiber used in the present invention is preferably a chopped strand, and the number of filaments of the carbon fiber strand that is a precursor of the chopped strand is preferably 1,000 to 150,000. When the number of filaments of the carbon fiber strand is within this range, the production cost can be suppressed and the stability in the production process can be secured.

  The strand elastic modulus of the (C) carbon fiber used in the present invention is not particularly limited, but is preferably 150 GPa or more, more preferably 220 GPa or more, and further preferably 250 GPa or more. Moreover, 1000 GPa or less is preferable, as for the upper limit of strand elastic modulus, 700 GPa or less is more preferable, More preferably, it is 500 GPa or less. When the strand elastic modulus is within this preferable range, the mechanical properties of the obtained molded product are further improved, and the production cost can be suppressed.

  The strand strength of the (C) carbon fiber used in the present invention is not particularly limited, but is preferably 1 GPa or more, more preferably 4 GPa or more, and further preferably 5 GPa or more. On the other hand, the upper limit of the strand strength is preferably 20 GPa or less, more preferably 15 GPa or less, and even more preferably 10 GPa or less. When the strand strength is within this range, the tensile strength of the obtained molded product is further improved, and the production cost can be suppressed.

  Here, the strand elastic modulus and strand strength refer to the elastic modulus and strength of a strand produced by impregnating and curing an epoxy resin to a continuous fiber bundle composed of 3,000 to 90,000 carbon fiber single fibers. This is a value obtained by subjecting the test piece to a tensile test according to JIS R7601.

  The (C) carbon fiber used in the present invention may be subjected to a surface oxidation treatment in order to improve adhesion with (A) an aromatic polycarbonate resin or (B) a thermoplastic polyester resin. Examples of the surface oxidation treatment include surface oxidation treatment by energization treatment, oxidation treatment in an oxidizing gas atmosphere such as ozone, and the like.

  In addition, the carbon fiber (C) used in the present invention may have a sizing agent or the like attached to the surface for the purpose of improving the wettability of the resin and improving the handleability. Examples of the sizing agent include a sizing agent containing at least one selected from a maleic anhydride compound, a urethane compound, an acrylic compound, an epoxy compound, a phenol compound, and derivatives of these compounds. A sizing agent containing a compound or an epoxy compound can be preferably used. (C) The content of the sizing agent in the carbon fiber is preferably 0.1 to 10.0% by weight, more preferably 0.3 to 8.0% by weight, and 0.5 to 6.0% by weight. % Is particularly preferred. (C) When the sizing agent in the carbon fiber is within this range, sufficient wettability can be obtained, and more excellent mechanical properties can be obtained.

  (C) A sizing agent is applied to the carbon fiber strand used in the present invention, and a method for producing a chopped carbon fiber is, for example, a method adopted in a glass fiber chopped strand in JP-B-62-9541 Alternatively, the methods described in JP-A-62-244606, JP-A-5-261729, and the like can be applied.

  The compounding amount of (C) carbon fiber in the resin composition of the present invention is 25 to 100 parts by weight, with the total compounding amount of (A) aromatic polycarbonate resin and (B) thermoplastic polyester resin being 100 parts by weight. (C) When the blending amount of the carbon fiber is less than 25 parts by weight, the bending elastic modulus of the obtained molded product is insufficient. (C) 30 weight part or more is preferable and, as for the compounding quantity of carbon fiber, 35 weight part or more is more preferable. On the other hand, when the compounding amount of (C) the carbon fiber exceeds 100 parts by weight, the fluidity of the resin composition and the weld strength of the molded product are lowered. (C) 90 weight part or less is preferable, as for the compounding quantity of carbon fiber, 80 weight part or less is more preferable, and 70 weight part or less is further more preferable.

  The resin composition of the present invention comprises (D) an alkoxysilane compound having an isocyanate group and / or an epoxy group. (D) By blending an alkoxysilane compound having an isocyanate group and / or an epoxy group, the isocyanate group and / or epoxy group reacts with the polymer ends of (A) an aromatic polycarbonate resin and (B) a thermoplastic polyester resin. As a result, the amount of functional groups at the polymer ends increases. (C) Interfacial adhesion to carbon fiber is improved by reaction or interaction between the polymer terminal functional group and the functional group and / or sizing agent on the carbon fiber surface, greatly increasing the weld strength and impact resistance of the molded product. It can be improved. When a thermoplastic resin composition highly filled with a fibrous filler is injection-molded, the weld portion has an orientation state parallel to the flow due to shear force and a vertical orientation state in the core layer. It is known that vertical orientation reduces weld strength. In particular, when a large amount of (C) carbon fiber is used as the fibrous filler, it is easy to form an aggregate in which the (C) carbon fiber is entangled inside the molded product. In addition to improving the interfacial adhesion between the thermoplastic resin and the (C) carbon fiber, the formation of the above-described aggregate can be suppressed and the weld strength can be greatly improved.

  The alkoxysilane compound (D) having an isocyanate group and / or an epoxy group used in the present invention has one or more isocyanate groups and / or epoxy groups in one molecule. It is preferable to have 1 to 3 alkoxy groups in one molecule. Two or more of these compounds may be used.

  Examples of the alkoxysilane compound having one or more isocyanate groups in one molecule include 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropylmethyldimethoxysilane, and 3-isocyanatepropylmethyldiethoxy. Silane, 3-isocyanatopropylethyldimethoxysilane, γ-isocyanatopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropylmethyldimethoxysilane, 3-isocyanatopropylmethyldiethoxysilane, 3-isocyanatopropylethyldimethoxy Silane, 3-isocyanatopropylethyldiethoxysilane, 3-isocyanatopropyltrichlorosilane, etc. It is.

  Examples of the alkoxysilane compound having one or more epoxy groups in one molecule include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl). Examples thereof include ethyltrimethoxysilane.

  Among these, from the point that (A) aromatic polycarbonate resin and (B) thermoplastic polyester resin, and (C) the interfacial adhesion between carbon fibers is improved and the weld strength of the resin composition is high, the isocyanate group is selected. The alkoxysilane compound to contain is preferable and 3-isocyanatopropyltriethoxysilane is more preferable.

  In the resin composition of the present invention, (D) the amount of the alkoxysilane compound having an isocyanate group and / or epoxy group is 100 parts by weight of the total amount of (A) the aromatic polycarbonate resin and (B) the thermoplastic polyester resin. Relative to 0.01 to 2 parts by weight. (D) When the compounding quantity of the alkoxysilane compound which has an isocyanate group and / or an epoxy group is less than 0.01 weight part, (C) The improvement in interfacial adhesiveness with carbon fiber is insufficient, and the weld in the molded product The effect of improving strength and impact resistance cannot be obtained sufficiently. (D) 0.05 weight part or more is preferable and, as for the compounding quantity of the alkoxysilane compound which has an isocyanate group and / or an epoxy group, 0.1 weight part or more is more preferable. On the other hand, when the blending amount of (D) the alkoxysilane compound having an isocyanate group and / or an epoxy group exceeds 2 parts by weight, the tensile strength of the molded product is lowered. (D) As for the compounding quantity of the alkoxysilane compound which has an isocyanate group and / or an epoxy group, 1.5 weight part or less is preferable.

  The resin composition of the present invention may further contain (E) a compound having three or more hydroxyl groups (hereinafter sometimes referred to as “(E) polyfunctional compound”). (E) By mix | blending a polyfunctional compound, the fluidity | liquidity of a resin composition can further be improved and the residual stress at the time of shaping | molding can be reduced. Further, (E) a part of the polyfunctional compound reacts with (A) an aromatic polycarbonate resin or (B) a thermoplastic polyester resin, and (C) the interfacial adhesion with the carbon fiber is improved. The strength of the product can be further improved.

  (E) Examples of the compound having three or more hydroxyl groups include 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,2,3, 6-hexanetetrol, glycerin, diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, triethanolamine, trimethylolethane, trimethylolpropane, ditrimethylolpropane, tritrimethylolpropane, 2-methylpropanetriol, 2 -Methyl-1,2,4-butanetriol, pentaerythritol, dipentaerythritol, tripentaerythritol, methylglucoside, sorbitol, mannitol, sucrose, 1,3,5-trihydroxybenzene, 1,2,4-trihydroxy Polymers such as polyhydric alcohol or a polyvinyl alcohol having a carbon number of 3 to 24, such as benzene and the like. Of these, glycerin, diglycerin, trimethylolpropane, ditrimethylolpropane, pentaerythritol, and dipentaerythritol having a branched structure are preferable from the viewpoint of further improving fluidity and mechanical properties.

  Moreover, it is preferable that (E) the compound which has a 3 or more hydroxyl group contains one or more alkylene oxide units from the point which is excellent by the fluidity | liquidity of a resin composition, and the strength improvement effect of a thin molded article. Preferable examples of the compound (E) having three or more hydroxyl groups containing one or more alkylene oxide units include (poly) oxyethylene glycerin, (poly) oxypropylene glycerin, (poly) oxyethylene diglycerin, (poly ) Oxypropylene diglycerin, (poly) oxyethylene trimethylolpropane, (poly) oxypropylene trimethylolpropane, (poly) oxyethylene ditrimethylolpropane, (poly) oxypropylene ditrimethylolpropane, (poly) oxyethylene pentaerythritol, (Poly) oxypropylene pentaerythritol, (poly) oxyethylene dipentaerythritol, (poly) oxypropylene dipentaerythritol are mentioned. (Poly) oxypropylene trimethylolpropane is preferable in terms of further improving the fluidity and strength of the thin molded article.

  The (E) polyfunctional compound used in the present invention preferably has a weight average molecular weight (Mw) in the range of 50 to 10,000, more preferably 150 to 8,000, from the viewpoint of further improving the fluidity and strength of the thin molded article. Is more preferable, and it is further more preferable that it is the range of 200-3000. In the present invention, Mw of (E) a polyfunctional compound is a value in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography (GPC) using hexafluoroisopropanol as a solvent.

  The blending amount of the (E) polyfunctional compound in the resin composition of the present invention is 0.01 to 5 weights, with the total blending amount of (A) aromatic polycarbonate resin and (B) thermoplastic polyester resin being 100 parts by weight. The range of parts is preferred. (E) The fluidity | liquidity of a resin composition and the intensity | strength of a thin molded article can be improved more as the compounding quantity of a polyfunctional compound is 0.01 weight part or more. 0.05 parts by weight or more is more preferable, and 0.1 parts by weight or more is more preferable. On the other hand, when the compounding amount of the (E) polyfunctional compound is 5 parts by weight or less, the mechanical properties of the molded product can be further improved. 4 parts by weight or less is more preferable, and 3 parts by weight or less is more preferable.

  The resin composition of the present invention includes a stabilizer (an antioxidant, an ultraviolet absorber, a weathering agent, etc.), a lubricant, a mold release agent, a flame retardant, a dye or a pigment as long as the object of the present invention is not impaired. An agent, an antistatic agent, a foaming agent and the like can be blended.

  In addition, the resin composition of the present invention includes a thermoplastic resin other than (A) an aromatic polycarbonate resin and (B) a thermoplastic polyester resin, and a thermosetting resin (for example, phenol) as long as the object of the present invention is not impaired. Resin, melamine resin, polyester resin, silicone resin, epoxy resin, etc.), soft thermoplastic resin (eg, ethylene / glycidyl methacrylate copolymer, ethylene / propylene terpolymer, ethylene / butene-1 copolymer, etc.) , Various core-shell type elastomers, polyamide elastomers, etc.) can be further blended. By blending these resins, it may be possible to obtain a molded product having excellent characteristics.

  In the resin composition of the present invention, each component is preferably dispersed uniformly, and any method can be used as a production method thereof. Representative examples include a method of melt kneading each component at a temperature of 200 to 350 ° C. using a known melt kneader such as a single or twin screw extruder, a Banbury mixer, a kneader, or a mixing roll. . Each component may be melt-kneaded after mixing in advance. In addition, although it is better that the water | moisture content adhering to each component is small and it is desirable to dry beforehand, it is not necessarily necessary to dry all the components.

  A preferred method for producing the carbon fiber reinforced aromatic polycarbonate resin composition of the present invention is to supply (A) to (D) and, if necessary, other additives to the twin screw extruder from the main raw material supply port or the side feeder. , A method of melt kneading under the conditions of a cylinder temperature of 200 to 300 ° C., preferably 220 to 260 ° C.

  In melt-kneading using a twin screw extruder, (A) an aromatic polycarbonate resin, (B) a thermoplastic polyester resin, (C) carbon fiber, (D) an alkoxysilane compound having an isocyanate group and / or an epoxy group and necessary There are no particular restrictions on the method for supplying the polyfunctional compound (E) according to the conditions, but (A) an aromatic polycarbonate resin, (B) a thermoplastic polyester resin, (D) an isocyanate group and / or an epoxy group. The alkoxysilane compound and the (E) polyfunctional compound are preferably supplied from the main raw material supply port, and (C) the carbon fiber can be supplied from the main raw material supply port, but the carbon fiber is cut in the kneading zone. It can also be introduced from the side feeder for the purpose of suppression.

  The resin composition of the present invention is rapidly cooled, for example, by passing the gut after being discharged from the die of a twin screw extruder through a cooling bath filled with water whose temperature is adjusted to 20 ° C. over about 10 seconds. After fixing, pellets can be obtained by pelletizing with a strand cutter. The pellet formed by molding the resin composition of the present invention preferably has a weight average fiber length of 0.01 to 2 mm of carbon fibers in the pellet. When the weight average fiber length of the carbon fibers in the pellet is 0.01 mm or more, the impact resistance of the obtained molded product can be further improved. 0.05 mm or more is more preferable, and 0.1 mm or more is more preferable. Moreover, when the weight average fiber length of the carbon fibers in the pellet is 2 mm or less, the fluidity at the time of molding is excellent, and the impact resistance of the molded product can be further improved. 1 mm or less is more preferable, and 0.5 mm or less is more preferable.

Here, the weight average fiber length of the carbon fibers in the pellet was determined by calcining the obtained pellet at 500 ° C. for 1 hour, dispersing the obtained ash in water, filtering, and then removing the residue with an optical microscope. It can be obtained by observing and measuring the result of measuring the length of 1,000 fibers into a weight average fiber length. Specifically, by putting about 10 g of resin composition pellets in a crucible, steaming until no flammable gas is generated on an electric stove, and then baking for another hour in an electric furnace set at 500 ° C. Only the carbon fiber residue is obtained. Observe an image of the residue magnified 50 to 100 times with an optical microscope, measure the length of 1,000 randomly selected lengths, and give the measured value (mm) (2 digits for the decimal point). And calculated based on the following formula 1 or 2.
Weight average fiber length (Lw) = Σ (Wi × Li) / ΣWi = Σ (π × ri ² × Li × ρ × ni × Li) / Σ (π × ri ² × Li × ρ × ni) ( Formula 1)

  Here, Li is the fiber length of the carbon fiber, ni is the number of carbon fibers of the fiber length Li, Wi is the weight of the carbon fiber of the fiber length Li, ri is the fiber diameter of the carbon fiber of the fiber length Li, and ρ is the carbon fiber Density, π, indicates a circular ratio, and the cross-sectional shape of the carbon fiber is approximated to a perfect circle having a fiber diameter ri.

When the fiber diameter ri and the density ρ are constant, the above formula 1 is approximated as follows, and the weight average fiber length can be obtained by the following formula 2.
Weight average fiber length (Lw) = Σ (Li ² × ni) / Σ (Li × ni) (Formula 2)

  The resin composition of the present invention can be usually produced by injection molding the pellets produced as described above to produce various products. In such injection molding, not only a normal molding method but also an injection compression molding, an injection press molding, a gas assist injection molding, a foam molding (including those by injection of a supercritical fluid), an insert molding, depending on the purpose as appropriate. A molded product can be obtained using an injection molding method such as in-mold coating molding, heat insulating mold molding, rapid heating / cooling mold molding, two-color molding, sandwich molding, and ultrahigh-speed injection molding. The advantages of these various molding methods are already widely known. In addition, either a cold runner method or a hot runner method can be selected for molding.

  The resin composition of the present invention can also be used in the form of various shaped extruded products, sheets, films, etc. by extrusion molding. Further, for forming a sheet or film, an inflation method, a calendar method, a casting method, or the like can be used. It is also possible to form a heat-shrinkable tube by applying a specific stretching operation. Further, the thermoplastic resin composition of the present invention can be made into a hollow molded product by rotational molding or blow molding.

  Although the molded object formed by using the resin composition of this invention does not have a restriction | limiting in particular, It can be set as the thin molded product which has a thin part with thin thickness. In the thin molded article of the present invention, the thickness of the thin part is preferably 0.01 to 2 mm. If the thickness of the thin portion is 0.01 mm or more, the moldability, the rigidity of the molded product, and the tensile strength can be compatible at a higher level. 0.05 mm or more is preferable and 0.1 mm or more is more preferable. On the other hand, if the thickness of the thin portion is 2 mm or less, the weight of the molded product can be reduced. 1.5 mm or less is preferable and 1 mm or less is more preferable.

  The weight average fiber length of the carbon fibers in the thin molded article of the present invention is not particularly limited, but is preferably in the range of 0.01 to 0.5 mm. If the weight average fiber length of the carbon fibers in the thin molded product is 0.01 mm or more, the rigidity, tensile strength, and impact resistance can be further improved. 0.125 mm or more is more preferable, and 0.15 mm or more is more preferable. On the other hand, if the weight average fiber length of the carbon fibers in the thin molded product is 0.5 mm or less, the rigidity, tensile strength, impact resistance and fluidity can be achieved at a higher level. 0.45 mm or less is more preferable, and 0.40 mm or less is more preferable.

  Here, the weight average fiber length in the molded product is the weight of the carbon fiber in the pellet after the obtained thin molded product is fired at 500 ° C. for 1 hour, and the obtained ash is dispersed in water, followed by filtration. The residue can be observed with an optical microscope in the same manner as the measurement of the average fiber length, and the result of measuring the length of 1,000 fibers can be obtained by converting the result into a weight average fiber length.

  The thin molded article formed by molding the resin composition of the present invention is useful for a wide range of applications. For example, it is suitable for parts such as electrical and electronic equipment, OA equipment, information terminal equipment, machine parts, home appliances, vehicle parts, building members, various containers, leisure goods / miscellaneous goods, lighting equipment, etc. It can be suitably used for a housing and a part of a device, and can be particularly suitably used for a housing and a part of an electric and electronic device having a weld portion.

  Examples of electrical and electronic equipment include digital cameras, video cameras, personal computers, notebook computers, televisions, video tape recorders, audio players, DVD players, air conditioners, mobile phones, displays, registers, calculators, copiers, printers, and facsimiles. It can be preferably used for parts or casings of digital cameras, video cameras, personal computers, laptop computers, more preferably digital cameras, video cameras, personal computers, laptop computers having a weld portion, especially for digital cameras, video cameras. It can be preferably used. Examples of the components of the electric / electronic device include covers and frames of various digital image information devices such as camera barrels, camera lens units, and digital cameras.

  In order to describe the present invention more specifically, examples and comparative examples will be described below, but the present invention is not limited to these examples.

  The evaluation method of an Example and a comparative example is shown next. Unless otherwise specified, “part” indicates “part by weight” and “%” indicates “% by weight”.

(1) Flexural modulus The flexural modulus was evaluated at 23 ° C. according to ISO178.

(2) Bending strength According to ISO178, bending strength was evaluated at 23 degreeC.

(3) Tensile strength According to ISO527, the tensile strength was evaluated at 23 degreeC.

(4) Weld strength Injection molding using a mold that has gates (flow channels through which the molten resin flows) at both ends of the ASTM No. 1 dumbbell, and a weld that joins the molten resin and the molten resin at the center of the ASTM No. 1 dumbbell. Then, ASTM No. 1 dumbbell was molded, a tensile test was performed according to ASTM D-638, and the weld strength was evaluated.

(5) Impact resistance According to ISO179, Charpy impact strength (notched) was evaluated at 23 ° C.

(6) Dimensional stability An 80 × 80 × 3 mm square plate is produced by injection molding, the dimensions in the flow direction (MD) and the direction perpendicular to the flow direction (TD) are measured, and the molding shrinkage is calculated by the following formula. evaluated.
(Actual dimension of mold (mm)-dimension of molded product (mm)) / actual dimension of mold (mm) x 100 (%)

(7) Weight average fiber length of carbon fiber 10 g of each sample was cut out from the pellets obtained in each of the examples and comparative examples and the tensile test piece prepared according to the item (3), and combustible gas was generated on an electric stove. After steaming until it stopped, it was baked in an electric furnace set at 500 ° C. for 1 hour, then dispersed in ion-exchanged water and filtered. The residue was observed with an optical microscope at a magnification of 20 to 100 times, the length of 1,000 randomly selected was measured, and the weight average fiber of carbon fibers in pellets and molded products according to (Formula 2) below Each length (mm) was determined.
Weight average fiber length (Lw) = Σ (Li ² × ni) / Σ (Li × ni) (Formula 2)
Here, Li represents the fiber length of the carbon fiber, and ni represents the number of carbon fibers having the fiber length Li.

(8) Fluidity According to ASTM D1238, melt mass flow rate (MFR) was measured and used as an index of fluidity. The measurement was carried out using a melt indexer manufactured by Toyo Seiki Seisakusho under the conditions of 280 ° C. and 2.2 N.

(9) Strength of thin molded product A test piece having a thickness of 200 × 12.7 × 1 mm was prepared, a bending test was performed under the same conditions as in (1), and a load (N) at break was measured.

The following were used as raw materials.
(A) Aromatic polycarbonate resin (A-1) Aromatic polycarbonate resin “Toughlon” (registered trademark) A1900 (manufactured by Idemitsu Kosan Co., Ltd., viscosity average molecular weight 19,000)
(B) Thermoplastic polyester resin (B-1) Polybutylene terephthalate resin “Toraycon” (registered trademark) 1100M (manufactured by Toray Industries, Inc., intrinsic viscosity (o-chlorophenol solution, 25 ° C.) 1.41, melting point 225 ° C. )
(C) Carbon fiber (C-1) Carbon fiber “Torayca” (registered trademark) Yarn T800SC-24K (manufactured by Toray Industries, Inc., tensile strength 5.88 GPa, tensile elastic modulus 294 GPa), resin component adhesion amount 3 A urethane resin emulsion: Superflex 300 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was attached to a weight of 0.0% by weight, dried in a drying oven at 200 ° C. to remove moisture, and then a fiber length of 6. A cut fiber cut to 0 mm was used.
(C-2) Carbon fiber “Torayca” (registered trademark) cut fiber TV14-006 (manufactured by Toray Industries, Inc., original yarn T700SC-12K: tensile strength 4.90 GPa, tensile modulus 230 GPa) was used.
(D) Alkoxysilane compound having an isocyanate group and / or an epoxy group (D-1) 3-isocyanatopropyltriethoxysilane (KBE-9007 manufactured by Shin-Etsu Chemical Co., Ltd.)
(D-2) 2- (3,4 Epoxycyclohexyl) ethyltrimethoxysilane (KBM-303 manufactured by Shin-Etsu Chemical Co., Ltd.)
(D ′) Alkoxysilane compound (D′-1) 3-aminopropyltrimethoxysilane having no isocyanate group or epoxy group (KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.)
(E) Compound having three or more hydroxyl groups (E-1) Polyoxypropylene trimethylolpropane (TMP-F32 manufactured by Nippon Emulsifier Co., Ltd., weight average molecular weight: 308).

(Examples 1-9, Comparative Examples 1-7)
About the composition of Table 1-2, (A) aromatic polycarbonate resin, (B) thermoplastic polyester resin, using the Nippon Steel Works twin screw extruder TEX30 (alpha) which set the cylinder temperature to 250 degreeC, ( D) Mainly an alkoxysilane compound having an isocyanate group and / or an epoxy group, if necessary (D ′) an alkoxysilane compound having neither an isocyanate group nor an epoxy group, and (E) a compound having three or more hydroxyl groups. After being supplied to the raw material supply port, (C) carbon fiber is supplied into the molten resin using a side feeder, the strand discharged from the die is cooled in water, and then cut to a length of 3.0 mm by a land cutter. The pelletization was carried out to obtain carbon fiber reinforced thermoplastic resin composition pellets.

  The carbon fiber reinforced thermoplastic resin composition pellets obtained above were vacuum dried at 80 ° C. for a whole day and night, and the molding temperature shown in Tables 1-2 was used using an injection molding machine SG75H-DUZ manufactured by Sumitomo Heavy Industries, Ltd. The above-mentioned method is set, mold temperature is 80 ° C., injection speed is 50 mm / sec, injection pressure is set to the conditions of molding lower limit pressure (minimum filling pressure) +5 MPa, and various test pieces are molded by injection molding. Evaluation of the characteristics was performed. The evaluation results are shown in Tables 1-2.

  The carbon fiber reinforced thermoplastic resin compositions of Examples 1 to 9 have a high flexural modulus, and are excellent in tensile strength, weld strength, impact resistance, dimensional stability and fluidity. On the other hand, it turns out that the resin composition shown in the comparative example is inferior in any one characteristic.

  The carbon fiber reinforced thermoplastic resin composition of the present invention is excellent in fluidity. Furthermore, according to the carbon fiber reinforced thermoplastic resin composition of the present invention, a molded article having high rigidity and tensile strength and improved weld strength can be obtained. Therefore, in addition to mechanical characteristics, it can be suitably used for housings and parts of electric and electronic devices such as housings for digital cameras and lens barrel parts that require dimensional accuracy, fluidity, and weld strength.

Claims (8)

(A) A resin composition comprising an aromatic polycarbonate resin, (B) a thermoplastic polyester resin, (C) carbon fiber, (D) an alkoxysilane compound having an isocyanate group and / or an epoxy group, The total blending amount of A) aromatic polycarbonate resin and (B) thermoplastic polyester resin is 100% by weight, (A) aromatic polycarbonate resin blending amount is 1 to 99% by weight, (B) thermoplastic polyester resin blending amount is 99 to 1% by weight, with (A) aromatic polycarbonate resin and (B) thermoplastic polyester resin being 100 parts by weight, (C) carbon fiber content is 25 to 100 parts by weight, (D) Carbon fiber reinforced heat in which the amount of the alkoxysilane compound having an isocyanate group and / or an epoxy group is 0.01 to 2 parts by weight Plastic resin composition. (B) The carbon fiber reinforced thermoplastic resin composition according to claim 1, wherein the thermoplastic polyester resin contains an aromatic polyester resin. (B) The carbon fiber reinforced thermoplastic resin composition according to claim 1 or 2, wherein the thermoplastic polyester resin contains polybutylene terephthalate. (D) The thermoplastic resin composition according to any one of claims 1 to 3, wherein the alkoxysilane compound having an isocyanate group and / or an epoxy group has an isocyanate group. The total amount of (A) aromatic polycarbonate resin and (B) thermoplastic polyester resin is 100 parts by weight, and (E) 0.01 to 5 parts by weight of a compound having three or more hydroxyl groups is added. Item 5. The carbon fiber reinforced thermoplastic resin composition according to any one of Items 1 to 4. The pellet formed by shape | molding the carbon fiber reinforced thermoplastic resin composition in any one of Claims 1-5, Comprising: The pellet whose weight average fiber length of the carbon fiber in a pellet is 0.01-2 mm. A thin molded product obtained by molding the pellet according to claim 6. The thin-walled molded article according to claim 7, which is a casing or a part of an electric / electronic device having a weld portion.