JP4485167B2 - Conductive thermoplastic resin composition - Google Patents

Description

  The present invention relates to a conductive thermoplastic resin composition. More specifically, it has excellent electrical conductivity, impact resistance, dimensional stability, heat resistance, fluidity, and appearance, and is suitable not only for automotive exterior parts, but also for electrical / electronic / OA equipment parts, machine parts, etc. Also relates to a suitable conductive thermoplastic resin composition.

  Many resin materials have been used in place of metal materials for electrical / electronic / OA equipment parts, machine parts, automotive exterior parts, etc., and in recent years, plastics have been actively used in automotive exterior parts. Yes. Among exterior parts, vertical metal panels such as fenders, door panels, rear panels, etc., are actively investigating the use of plastics from conventional metal materials. The advantages of plastics include weight reduction, design flexibility, and module assembly. The pedestrian protection and the like can be mentioned, and higher level materials such as impact resistance, dimensional stability, fluidity, and appearance have been required as compared with conventional plastic parts. Parts used together with metal materials such as steel plates, mainly these automobile exterior parts, are painted for coloring, and electrostatic coating is generally performed to improve the adhesion efficiency of the paint. . Electrostatic coating uses a grounded coating as an anode and a coating atomizer as a cathode. A negative high voltage is applied to this to create an electrostatic field between the two electrodes, and the atomized coating particles are charged negatively. This is a painting method in which a paint is efficiently adsorbed on an object that is the opposite electrode. Since thermoplastic resin is electrically insulating, it needs to be electrically conductive for electrostatic coating, and it must contain conductive carbon black to obtain high conductivity with a small amount of conductive material. A lot has been done.

  On the other hand, for example, OA equipment and electronic equipment are becoming smaller and lighter, higher integration, and higher precision, and as a result, the adhesion of dust and dust to electrical and electronic parts is reduced as much as possible, and errors due to static electricity disturbances. The market demand for conductive resins to prevent operation is increasing year by year. For example, IC chips used in semiconductors, IC trays, wafers, internal parts of hard disks used in computers, etc. are more demanding and should be given antistatic properties to completely prevent dust and dust from adhering. is required. In addition, electrical conductivity is also required for components that need to be provided with electromagnetic wave shielding properties, such as notebook personal computer housings, PDA housings, pachinko component substrates, camera shutters, and mobile phone housings.

  For such applications, many resin compositions in which conductive carbon black is blended with a resin composition (polymer alloy) of a polyamide resin and a polyphenylene ether resin have been proposed and are widely known as materials for automobile exterior parts. Yes. However, since the polyamide resin is the main component, there is a problem that the dimensions change due to water absorption. Furthermore, since the coefficient of linear expansion is large, when designing parts in anticipation of thermal expansion under high-temperature use environments, the gap between parts becomes large, and the main component is a crystalline polyamide resin. There was also a problem such as a loss of appearance due to an increase in dimensional change (heating shrinkage rate) during heating.

  Therefore, a resin composition in which conductive carbon black is blended with a polymer alloy of an aromatic polyester resin and an aromatic polycarbonate resin has been proposed as a conductive resin composition that does not change with time due to water absorption. Patent Documents 1 and 2 propose resin compositions composed of aromatic polycarbonate, thermoplastic polyester, rubber-like resin, and carbon black. However, the composition of Patent Document 1 is inferior in fluidity and appearance because it contains a large amount of carbon black. In Patent Document 2, there is no specific description regarding fluidity, conductivity, dimensional stability, and appearance, The disclosed composition is a polymer alloy mainly composed of an aromatic polyester resin or a polymer alloy with a polybutylene terephthalate resin, and is not sufficiently satisfactory in terms of the balance of conductivity and dimensional stability. Furthermore, Patent Document 3 proposes a resin composition composed of aromatic polycarbonate, polybutylene terephthalate, butadiene rubber-like elastic copolymer, carbon black, and inorganic filler, but there is no specific description regarding conductivity, and disclosure is made. The composition is not sufficient in terms of the balance of conductivity, impact resistance, dimensional stability, etc., and a high level of material is required in terms of conductivity, impact resistance, dimensional stability, fluidity, appearance, etc. It was done.

  In addition, a conductive sheet (Patent Document 4) made of polycarbonate, aromatic polyester, and carbon black, and a resin composition (Patent Document 5) made of polycarbonate resin, polyester resin, and carbon black and having excellent jetness have been proposed. However, in Patent Document 3, there is no specific description or mention regarding impact resistance, dimensional stability, and appearance. Further, Patent Document 4 does not mention anything other than jetness, and all of the disclosed compositions. Since carbon black with a large specific surface area was blended, it was not satisfactory in terms of fluidity and appearance.

Japanese Patent Application Laid-Open No. 58-136362 Japanese Unexamined Patent Publication No. 62-185743 Japanese Unexamined Patent Publication No. 63-132961 Japanese Unexamined Patent Publication No. 7-330925 JP-A-4-342759

  The present invention has reached the specific composition of the present invention as a result of intensive studies aimed at providing a conductive thermoplastic resin composition that eliminates the above-mentioned conventional drawbacks. That is, an object of the present invention is to provide a conductive thermoplastic resin composition that is excellent in conductivity and excellent in impact resistance, dimensional stability, heat resistance, fluidity, and appearance.

That is, the gist of the present invention is that (A) 51 to 90 parts by weight of an aromatic polycarbonate resin (hereinafter sometimes abbreviated as A component) and (B) a polyethylene terephthalate resin (hereinafter abbreviated as B component). ) (C) Specific surface area (BET type nitrogen adsorption method) is 150 to 1000 m ² / g and dibutyl phthalate oil absorption is 100 to 450 ml / 100 g with respect to a composition comprising 10 parts by weight of 10 to 49 parts by weight. conductive carbon black and / or hollow carbon fibril (hereinafter sometimes to be abbreviated as C component) Ri greens by blending 0.1 to 5 parts by weight, Moreover, a component continuous phase (hereinafter, "sea phase" In the B component, which has a micro form of sea-island structure, in which the B component constitutes a discontinuous phase (hereinafter referred to as “island phase”), and the C component mainly constitutes the island phase. Exists, or ,
The conductive thermoplastic resin composition satisfies the following specifications .
1) Load deflection temperature is 125 ° C or higher (however, the test method is based on ASTM D648)
2) Heat shrinkage rate is 0.40% or less (however, the test method was evaluated by aging for 40 minutes in a 120 ° C. hot air oven for a 100 mmφ disk-shaped molded product (thickness 3 mm)).
3) Volume resistivity is 1 × 10 ⁸ Ωcm or less (however, the test method is obtained by cutting both ends of ASTM No. 2 dumbbell test piece (thickness 3.2 mm) at both ends so that the length is 50 mm and cutting. After applying a silver paste to both end faces and drying at room temperature, the resistance value (RL: unit Ω) between the both end faces was measured with a tester, and the volume resistivity R (unit: Ωcm) was calculated from the following formula: Calculated.
R = RL × AL / L
(In the formula, AL means the cross-sectional area (unit: cm ² ) of the test piece, and L means the length (unit: cm) of the test piece.)}

The conductive thermoplastic resin composition of the present invention is excellent in conductivity and also excellent in impact resistance, dimensional stability, heat resistance, fluidity, and appearance. Therefore, as a major application of the conductive thermoplastic resin composition having such features, bumpers, fenders, door panels, trunk lids, front panels, rear panels, roof panels, bonnets, pillars, side moldings, garnishes, wheel caps, doors Car exterior parts such as handles, hood bulges, fuel lids, and various spoilers.
Moreover, the conductive thermoplastic resin composition of the present invention can be suitably used for applications requiring electrical conductivity such as, for example, electrical / electronic / OA equipment, in addition to automotive exterior parts. For example, IC chips used in semiconductors, IC trays, wafers, internal parts of hard disks used in computers, etc. need to be optimally conductive in order to provide antistatic properties and completely prevent dust and dust from adhering. It is not satisfied if it is too high or too low. For such applications, a volume resistivity in the range of 2 × 10 ² to 1 × 10 ⁸ Ωcm is selected. On the other hand, in applications where conductivity is required for imparting electromagnetic wave shielding properties, such as notebook PC housings, PDA housings, pachinko parts substrates, camera shutters, mobile phone housings, etc., there is a problem even if the volume resistivity is low. There is no.

(A) Aromatic polycarbonate resin (component A)
The aromatic polycarbonate resin which is the component A of the present invention is an optionally branched thermoplastic aromatic obtained by reacting an aromatic dihydroxy compound or a small amount of a polyhydroxy compound with a carbonate precursor. Polycarbonate polymer or copolymer. The method for producing the aromatic polycarbonate resin is not particularly limited, and the aromatic polycarbonate resin can be produced by a conventionally known phosgene method (interfacial polymerization method), melting method (transesterification method), or the like.

As aromatic dihydroxy compounds, 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A), 2,2-bis (3,5-dibromo-4-hydroxyphenyl) 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-dimethyl) Phenyl) propane, 2,2-bis (3-bromo-4-hydroxyphenyl) propane, 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-trichloropropane, 2,2-bis (4-hydroxyphenyl) Bis (exemplified by -1,1,1,3,3,3-hexachloropropane, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane, etc. Hydroxyaryl) alkanes; 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) silane Bis (hydroxyaryl) cycloalkanes exemplified by rhohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and the like; 9,9-bis (4-hydroxyphenyl) fluorene, Cardo structure-containing bisphenols exemplified by 9,9-bis (4-hydroxy-3-methylphenyl) fluorene; 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, etc. Dihydroxy diaryl ethers, such as 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfide, etc .; 4,4′-dihydroxydiphenyl Sulfoxide, 4,4'-dihydroxy Dihydroxydiaryl sulfoxides exemplified by -3,3'-dimethyldiphenyl sulfoxide and the like; dihydroxydiaryls exemplified by 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone and the like Sulfones; hydroquinone, resorcin, 4,4′-dihydroxydiphenyl and the like. These aromatic dihydroxy compounds may be used alone or in combination of two or more. Among these, 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A) is particularly preferably used from the viewpoint of impact resistance.

  As the carbonate precursor to be reacted with the aromatic dihydroxy compound, carbonyl halide, carbonate ester or haloformate is used. Specifically, phosgene; diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dimethyl carbonate, diethyl carbonate and the like Dialkyl carbonates; dihaloformates of dihydric phenols and the like.

  The aromatic polycarbonate resin may be a branched aromatic polycarbonate resin obtained by copolymerizing a trifunctional or higher polyfunctional aromatic compound. In order to obtain a branched aromatic polycarbonate resin, 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, 1,1, Polyhydroxy compounds represented by 1-tri (4-hydroxyphenyl) ethane or the like, or 3,3-bis (4-hydroxyaryl) oxindole (= isatin bisphenol), 5-chloruisatin, 5,7-dichloroisatin The aromatic dihydroxy compound may be used by substituting a part of the aromatic dihydroxy compound with 5-bromoisatin or the like. Range are preferred, particularly preferred is 0.1 to 2 mol%.

In producing the aromatic polycarbonate resin by reacting the dihydric phenol and the carbonate precursor by the interfacial polycondensation method or the melt transesterification method, a terminal stopper may be used as necessary. In the case of a legal aromatic polycarbonate resin, a terminal terminator or a molecular weight modifier is used. Examples of the terminal terminator or the molecular weight regulator include compounds having a monovalent phenolic hydroxyl group or a monovalent carboxylic acid derivative structure. Examples of the compound having a monovalent phenolic hydroxyl group include substituted phenols such as phenol, alkylphenol, halogenated phenol, alkoxyphenol, and alkoxycarbonylphenol. Specifically, phenol, methylphenol, pn -Butylphenol, p-tert-butylphenol, p-tert-octylphenol, allylphenol, cumylphenol, naphthylphenol, naphthol, bromophenol, tribromophenol, trifluorophenol, methoxyphenol, butoxyphenol, methoxycarbonylphenol, butoxycarbonyl Phenol, dodecyloxycarbonylphenol, octadecyloxycarbonylphenol and the like can be mentioned. Examples of the compound having a monovalent carboxylic acid derivative structure include carboxylic acid, carboxylic acid chloride and the like, and specifically, acetic acid, acrylic acid, formic acid, propionic acid, propiolic acid, butyric acid, isobutyric acid, methacrylic acid. Acid, palmitic acid, stearic acid, pyruvic acid, acetoacetic acid, glycolic acid, lactic acid, glyceric acid, hexafluoroacetic acid, benzoic acid, naphthoic acid, methylbenzoic acid, butylbenzoic acid, vinylbenzoic acid, pentafluorobenzoic acid, pentabromo Examples thereof include carboxylic acids such as benzoic acid, methyl naphthoic acid, and ethyl naphthoic acid, and carboxylic acid chlorides derived from these carboxylic acids.
Also, in the case of an ester exchange aromatic polycarbonate resin, the amount ratio of the terminal hydroxy terminal structure is usually adjusted by adjusting the molar ratio of the raw dihydroxy compound and the carbonic acid diester or by adjusting the degree of vacuum. Can be adjusted. Further, as a more aggressive method, an adjustment method in which a terminal terminator is added separately during the reaction is also well known. Examples of the terminal terminator used here include monohydric phenols, monocarboxylic acids, and carbonic acid diesters. For example, monohydric phenols and monohydric carboxylic acids having 9 or more carbon atoms are preferably used. P-propylphenol, o-sec-butylphenol, p-tert-butylphenol, cumylphenol, tert-octylphenol, phenylphenol, naphthylphenol, 4-hydroxy-p-quarterphenyl, butylbenzoic acid, octylbenzoic acid , Phenylbenzoic acid, naphthalenecarboxylic acid, and the like. As the carbonic acid diesters, for example, carbonic acid diesters derived from monohydric phenols having 9 or more carbon atoms are preferably used. Phenyl carbonate, di (butylphenyl) carbonate DOO, phenyl cumyl phenyl carbonate, di (nonylphenyl) carbonate, and the like methylphenyl naphthyl phenyl carbonate.

  Furthermore, the polyester carbonate which copolymerized the aromatic or aliphatic bifunctional carboxylic acid may be sufficient. Examples of the aliphatic bifunctional carboxylic acid include aliphatic bifunctional carboxylic acids having 8 to 20 carbon atoms, preferably 10 to 12 carbon atoms. Such aliphatic difunctional carboxylic acid may be linear, branched or cyclic. The aliphatic bifunctional carboxylic acid is preferably α, ω-dicarboxylic acid. Preferred examples of the aliphatic bifunctional carboxylic acid include linear saturated aliphatic dicarboxylic acids such as sebacic acid (decanedioic acid), dodecanedioic acid, tetradecanedioic acid, octadecanedioic acid, and eicosanedioic acid.

  Further, a polycarbonate-polyorganosiloxane copolymer obtained by copolymerizing polyorganosiloxane units can be used.

  Aromatic polycarbonate resins are the above-mentioned different polycarbonate resins of various dihydric phenols, branched polycarbonate resins containing branching components, aromatic polycarbonate resins having different production methods, aromatic polycarbonate resins having different terminal terminators, various polyester carbonates, It may be a mixture of two or more of various aromatic polycarbonate resins such as a polycarbonate-polyorganosiloxane copolymer.

  The molecular weight of the aromatic polycarbonate resin is preferably in the range of 10,000 to 30,000 in terms of viscosity average molecular weight converted from the solution viscosity measured at a temperature of 20 ° C. using methylene chloride as a solvent. When the viscosity average molecular weight is less than 10,000, the impact resistance of the molded product obtained from the conductive thermoplastic resin composition according to the present invention is insufficient, and when it exceeds 30,000, the moldability of the resin composition itself. However, neither is preferable. A more preferred range for the viscosity average molecular weight is 13,000 to 28,000, with 15,000 to 25,000 being particularly preferred.

  Moreover, the aromatic polycarbonate resin which is A component of this invention may contain the aromatic polycarbonate oligomer. The viscosity average molecular weight of the aromatic polycarbonate oligomer is preferably 1,500 to 9,500, more preferably 2,000 to 9,000. The content of the polycarbonate oligomer is preferably used in the range of 30% by weight or less in the aromatic polycarbonate resin.

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

(B) Polyethylene terephthalate resin (component B)
The polyethylene terephthalate resin as component B of the present invention is composed of terephthalic acid as a main component as a dicarboxylic acid component and ethylene glycol as a diol component as a main component, and a saturated polyester polymer or copolymer obtained by a condensation reaction thereof. The thermoplastic polyester resin preferably contains 70 mol% or more, more preferably 80 mol% or more of ethylene terephthalate units as repeating units. According to a conventional method, the polyethylene terephthalate resin is produced by reacting the dicarboxylic acid component and the diol component with heating in the presence of a polycondensation catalyst containing titanium, germanium, antimony, etc. It is carried out by discharging the alcohol out of the system, and it is possible to adopt either a batch type or continuous type polymerization method, and it is also possible to increase the degree of polymerization by solid phase polymerization.

  The polyethylene terephthalate resin of the present invention may contain an aromatic dicarboxylic acid other than terephthalic acid as a copolymerization component. Examples of the aromatic dicarboxylic acid include isophthalic acid, 2-chloroterephthalic acid, 2,5-dichloroterephthalic acid, 2-methylterephthalic acid, 4,4-stilbene dicarboxylic acid, 4,4-biphenyldicarboxylic acid, and orthophthalic acid. 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, bisbenzoic acid, bis (p-carboxyphenyl) methane, anthracene dicarboxylic acid, 4,4-diphenyl ether dicarboxylic acid, 4,4-diphenoxyethanedicarboxylic acid Acid, 5-Na sulfoisophthalic acid, ethylene-bis-p-benzoic acid and the like. These aromatic dicarboxylic acids are not limited to one type, and two or more types can be used. The amount of aromatic dicarboxylic acid other than terephthalic acid is preferably 30 mol% or less, more preferably 20 mol% or less, when the total amount of dicarboxylic acid components is 100 mol%. Furthermore, if the polyethylene terephthalate resin of this invention is less than 30 mol% with respect to the whole quantity of a dicarboxylic acid component, it can also contain aliphatic dicarboxylic acid as a copolymerization component. Examples of the aliphatic dicarboxylic acid include adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and the like.

  The polyethylene terephthalate resin of the present invention may contain a diol other than ethylene glycol as a copolymer component. Examples of such diols include diethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, trans- or -2,2,4,4-tetramethyl- 1,3-cyclobutanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, decamethylene Examples include glycol, cyclohexanediol, p-xylenediol, bisphenol A, tetrabromobisphenol A, and tetrabromobisphenol A-bis (2-hydroxyethyl ether). These diols are not limited to one type, and two or more types can be used.

  Furthermore, the polyethylene terephthalate resin of the present invention contains diethylene glycol, which is a side reaction product during polymerization, as a copolymerization component. The amount of diethylene glycol is usually about 0.5 mol% or more, preferably 6 mol% or less, more preferably 5 mol% or less, in 100 mol% of the total amount of diol components.

  The intrinsic viscosity of the polyethylene terephthalate resin is preferably 0.4 to 1.5 dl / g, more preferably 0.5 to 1.2 dl / g. Here, the intrinsic viscosity is measured at 30 ° C. in a solvent of phenol / tetrachloroethane = 50/50 (weight ratio). If the intrinsic viscosity is less than 0.4, the impact resistance tends to decrease, and if it exceeds 1.5, the fluidity tends to decrease. Moreover, the amount of terminal carboxyl groups of the polyethylene terephthalate resin is preferably 5 to 50 eq / t, and more preferably 10 to 30 eq / t. When the terminal carboxyl group amount is less than 5 eq / t, the heat resistance and impact resistance are liable to decrease, and when it exceeds 50 eq / t, the moist heat resistance and thermal stability tend to be insufficient.

  Furthermore, as the polyethylene terephthalate resin as the component B of the present invention, not only a virgin raw material but also a polyethylene terephthalate resin regenerated from a used product, a so-called material recycled polyethylene terephthalate resin can be used. Spent products include mainly containers, films, sheets, fibers, etc., but more suitable are containers such as PET bottles. In addition, as the recycled polyethylene terephthalate resin, non-conforming products, pulverized products obtained from sprues, runners, etc., or pellets obtained by melting them can be used.

(C) Conductive carbon black and / or hollow carbon fibril (component C)
The conductive carbon black which is the component C of the present invention is a conductive carbon black having a specific surface area (BET nitrogen adsorption method) of 150 to 1000 m ² / g. What is carbon black for pigments added to paints or the like for coloring purposes? In contrast, it is in the form of a series of fine particles. The specific surface area is determined by the BET nitrogen adsorption method, and more preferable conductive carbon black is in the range of 200 to 900 m ² / g. If the specific surface area exceeds 1000 m ² / g, the resulting resin composition is inferior in terms of fluidity and appearance, and if it is less than 150 m ² / g, it is inferior in terms of conductivity.
In addition, conductive carbon black having a dibutyl phthalate (DBP) oil absorption measured in accordance with ASTM D2414 of 100 to 450 ml / 100 g is preferable, and that of 150 to 400 ml / 100 g is a balance between conductivity and impact resistance. This is more preferable.
Examples of such preferable conductive carbon black include a furnace method conductive carbon black in which raw material hydrocarbons are pyrolyzed by the combustion heat of crude oil or gas to generate carbon black, and ketjen black obtained by a heavy oil gasification process. Acetylene black obtained by thermally decomposing acetylene gas, and the like, for example, Ketjen black EC (specific surface area 800 m ² / g, oil absorption 360 ml / 100 g) manufactured by Lion, Vulcan XC-72 manufactured by Cabot (Specific surface area 250 m ² / g, oil absorption 178 ml / 100 g), Denexa Printex L6 (specific surface area 250 m ² / g, oil absorption 123 ml / 100 g) and the like are commercially available.

Further, the hollow carbon fibril which is the C component of the present invention has an outer region composed of an essentially continuous multi-layer of regularly arranged carbon atoms, and an inner hollow region. They are essentially cylindrical fibrils that are arranged substantially concentrically. Further, it is preferable that the regularly arranged carbon atoms in the outer region are graphite-like and the hollow region has a diameter in the range of 2 to 20 nm.
Such a component C is described in detail in Japanese Patent Publication No. 62-5000943, US Pat. No. 4,663,230, and the like. As described in detail in the latter U.S. patent specification, the hollow carbon fibril is produced by, for example, transition metal-containing particles such as iron, cobalt, and nickel-containing particles on an alumina support, carbon monoxide, Examples include a method in which a carbon-containing gas such as hydrocarbon is contacted at a high temperature of 850 to 1200 ° C., and carbon generated by pyrolysis is grown into a fiber starting from a transition metal. The C component hollow carbon fibril is sold by Hyperion Catharsis under the trade name of graphite fibril and can be easily obtained.

(D) Rubber polymer (component D)
The conductive thermoplastic resin composition according to the present invention must contain the A component, the B component, and the C component, but for the purpose of improving the impact resistance of the resin composition, the conductive thermoplastic resin composition is further used as a D component. It is preferable to contain a rubbery polymer (hereinafter sometimes abbreviated as D component). Here, the rubbery polymer means a rubbery polymer having a glass transition temperature of 0 ° C. or lower, preferably −20 ° C. or lower, or a monomer copolymerizable with the rubbery polymer as necessary. A polymer obtained by copolymerizing components. The rubbery polymer of component D used in the present invention is not particularly limited as long as it is generally blended in a polycarbonate resin composition and can improve its mechanical properties.

  Examples of rubber-like polymers include polybutadiene, polyisoprene, diene copolymers (styrene / butadiene copolymers, acrylonitrile / butadiene copolymers, acrylic / butadiene rubber, etc.), copolymers of ethylene and α-olefins ( Ethylene / propylene copolymer, ethylene / butene copolymer, ethylene / octene copolymer, etc.), copolymer of ethylene and unsaturated carboxylic acid ester (ethylene / methacrylate copolymer, ethylene / butyl acrylate copolymer) Etc.), copolymers of ethylene and aliphatic vinyl compounds, terpolymers of ethylene, propylene and nonconjugated dienes, acrylic rubber (polybutyl acrylate, poly (2-ethylhexyl acrylate), butyl acrylate / 2-ethylhexyl acrylate Polymers), silicone Rubber (polyorganosiloxane rubber; consisting of a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber IPN type composite rubber etc.) and the like.

  Preferred examples of the monomer component copolymerized with such a rubbery polymer include aromatic vinyl compounds, vinyl cyanide compounds, (meth) acrylic acid ester compounds, and (meth) acrylic acid compounds. . As other monomer components, epoxy group-containing (meth) acrylic acid ester compounds such as glycidyl (meth) acrylate; maleimide compounds such as maleimide, N-methylmaleimide, N-phenylmaleimide; maleic acid, maleic anhydride, Examples thereof include α, β-unsaturated carboxylic acid compounds such as phthalic acid, itaconic acid and anhydrides thereof.

A preferred specific example of the rubber polymer is a core / shell type graft copolymer. Among these, at least one rubber-like polymer selected from butadiene-containing rubber, butyl acrylate-containing rubber, and silicone rubber is used. A core / shell type graft copolymer comprising a shell layer formed by polymerizing at least one monomer selected from an acrylic ester, a methacrylic ester and an aromatic vinyl compound around the core layer is particularly preferred. More specifically, methyl methacrylate-butadiene-styrene polymer (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene polymer (MABS), methyl methacrylate-butadiene polymer (MB), methyl methacrylate-acrylic rubber polymer ( MA), methyl methacrylate-acrylic rubber-styrene polymer (MAS), methyl methacrylate-acrylic butadiene rubber copolymer, methyl methacrylate-acrylic butadiene rubber-styrene copolymer, methyl methacrylate- (acrylic silicone IPN rubber) A polymer etc. can be mentioned.
Preferred examples of other rubbery polymers include polybutadiene rubber, styrene-butadiene copolymer (SBR), styrene-butadiene-styrene block copolymer (SBS), and styrene-ethylene / butylene-styrene block copolymer. Polymer (SEBS), styrene-ethylene / propylene-styrene block copolymer (SEPS), acrylonitrile-butadiene-styrene polymer (ABS), acrylonitrile-styrene-acrylic rubber polymer (ASA), acrylonitrile-ethylenepropylene rubber-styrene A polymer (AES) etc. can be mentioned.
Such rubbery polymers can be used alone or in combination of two or more.

Conductive thermoplastic resin composition The conductive thermoplastic resin composition of the present invention comprising the aforementioned constituent components (AC components) has a sea-island structure in micro form. Specifically, it has a so-called sea-island micro form in which the A component constitutes a continuous phase (sea phase) and the B component constitutes a discontinuous phase (island phase) dispersed in the continuous phase. The C component is present mainly in the B component constituting the island phase. Such micro morphology can be easily confirmed with an electron microscope. That is, from a pellet or molded product of the resin composition itself, an ultra thin film (REICHERT-NSSEIPCS) equipped ultra cryotome (ULTRACUT CUT manufactured by Leica) with a diamond knife at -100 ° C. and a thickness of 100 nm. A section is cut out, the cut section is stained with ruthenium tetroxide (RuO ₄ ), and observed with a transmission electron microscope (manufactured by JEOL Ltd., model: JEM1200EXII type) to observe the dispersed form of each component. can do. Among the resin components, the A component is observed in a darker color than the B component, and the C component is observed in a slightly dark color without staining.

The conductive thermoplastic resin composition of the present invention is excellent in impact strength and dimensional stability because the component A comprising an aromatic polycarbonate resin is in the sea phase. Moreover, since the C component of the conductive carbon black and / or hollow carbon fibril is mainly present in the B component constituting the island phase, the fluidity and impact strength of the resin composition can be reduced even if the C component is blended. The decline is small. Furthermore, the C component that exhibits electrical conductivity has a unique phenomenon that the electrical conductivity of the resin composition itself or the molded product is very excellent, despite being mainly present in the B component that constitutes the island phase. The expression is a major characteristic of the conductive thermoplastic resin composition of the present invention.
Here, “mainly” means that more than half of the C component is present in the B component, preferably 65% or more, and most preferably 85% or more. By dispersing more than half of the C component in the B component, a conductive thermoplastic resin composition having excellent mechanical strength, particularly surface impact strength required for an automobile outer plate and paintability, can be obtained.

In the conductive thermoplastic resin composition of the present invention, the blending ratio of component A to component C, and component D, which is an optional component,
(A) A composition comprising a total of 100 parts by weight of an aromatic polycarbonate resin (component A) 51 to 90 parts by weight and (B) a polyethylene terephthalate resin (component B) 10 to 49 parts by weight,
(C) The specific surface area (BET type nitrogen adsorption method) is required to be 0.1 to 5 parts by weight of conductive carbon black and / or hollow carbon fibrils (component C) of 150 to 1000 m ² / g,
As needed, it is preferable that it is 0.5-30 weight part of (D) rubber-like polymer (D component).

The mixing ratio of the A component and the B component is 51 to 90 parts by weight, preferably 55 to 80 parts by weight, and 10 to 49 parts by weight of the B component, preferably 20 parts in 100 parts by weight of the total amount of the A and B components. -45 parts by weight. If the A component is less than 51 parts by weight, the A component may not become a continuous phase, and as a result, the conductivity, dimensional stability, and impact resistance of the resin composition may be insufficient. On the other hand, when the B component is less than 10 parts by weight, the ratio of the B component mainly containing the C component that develops conductivity decreases, so that the conductivity of the resin composition decreases.
The blending ratio of component C is 0.1 to 5 parts by weight, preferably 0.5 to 4.5 parts by weight, more preferably 1 to 4 parts by weight with respect to 100 parts by weight of the total of component A and component B. . When the C component is less than 0.1 part by weight, the conductivity of the resin composition is insufficient, and when the C component exceeds 5 parts by weight, the fluidity, impact resistance, and appearance of the resin composition are deteriorated. Moreover, the compounding ratio of D component is 0.5-30 weight part with respect to a total of 100 weight part of A component and B component, Preferably it is 1-20 weight part. When the D component is less than 0.5 part by weight, the impact resistance improving effect of the resin composition is small, and when it exceeds 30 parts by weight, the heat resistance (load deflection temperature), rigidity, and dimensional characteristics of the resin composition are greatly decreased.

  The conductive thermoplastic resin composition according to the present invention may contain other resins as long as the effects of the present invention are not impaired. Examples of other resins include thermoplastic polyester resins other than polyethylene terephthalate (polybutylene terephthalate resin, polypropylene terephthalate resin, polyhexylene terephthalate resin, polyethylene naphthalate resin, poly (1,4-cyclohexanedimethylene terephthalate) resin, Liquid crystal polyester, etc.), polyamide resins, polyimide resins, polyetherimide resins, polyurethane resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, polyolefin resins such as polyethylene and polypropylene, styrenes such as polystyrene and acrylonitrile-styrene copolymers Examples thereof include resins such as resins, polymethacrylate resins, phenol resins, and epoxy resins.

  The conductive thermoplastic resin composition according to the present invention must contain the component A, component B and component C, but for the purpose of improving the dimensional stability and heat resistance of the resin composition, An inorganic filler other than the component C can be contained. The inorganic filler used in the present invention is a powder of an inorganic compound other than the component C. The form of the powder may be any of spherical, plate-like, needle-like, fiber-like, etc., but in order to improve the dimensional stability and heat resistance of the finally obtained resin composition, plate-like, needle-like And fibrous materials are preferred. Therefore, in the present invention, the shape of the inorganic filler is clearly distinguished into a spherical shape, a plate shape, a needle shape, and a fiber shape as follows. In the case of a spherical shape, it includes not only a true spherical shape but also an elliptical cross section to some extent and an aspect ratio close to 1. In the case of a plate-like shape, it indicates a plate-like shape and has an aspect ratio (longest length of plate-like surface of plate-like powder / thickness of plate-like powder) in the range of 2-100. In the case of a needle shape, the length is 100 μm or less and the aspect ratio (particle length / particle diameter) is in the range of 2 to 20, and in the case of a fibrous shape, the length exceeds 100 μm. These can be easily distinguished by electron micrographs.

  Specific examples of such plate-like, needle-like, and fibrous inorganic fillers include, as the plate-like filler, magnesium silicate such as talc, clay, mica, graphite, sericite, montmorillonite, plate-like calcium carbonate, plate Alumina, glass flakes, etc., and acicular fillers include calcium silicates such as wollastonite, moss heidi, zonotlite, calcium titanate, aluminum borate, acicular calcium carbonate, acicular titanium oxide, tetrapot type zinc oxide, etc. Examples of the fibrous filler include glass fiber and carbon fiber. Among these inorganic fillers, talc, mica, glass flakes, wollastonite, glass fibers, and carbon fibers are preferable in terms of the balance of impact resistance, dimensional stability, fluidity, and product appearance. From the viewpoint of appearance, talc and wollastonite are preferable. The details of the components and the like of the inorganic filler in the present invention are described in, for example, “Filler Usage Dictionary” (edited by Filler Research Society, Taiseisha, 1994).

  The average particle diameter of these inorganic fillers is preferably 0.1 to 25 μm, more preferably 0.5 to 15 μm in the case of plate-like and needle-like fillers. If the average particle size is less than 0.1 μm, the reinforcing effect tends to be insufficient, and if it exceeds 25 μm, the product appearance tends to be adversely affected. Here, the average particle diameter means D50 measured by a liquid phase precipitation method by X-ray transmission. As an apparatus capable of performing such measurement, a Sedigraph particle size analyzer (manufactured by Micromeritics Instruments, model 5100) can be mentioned. Further, the fiber diameter of the fibrous filler is preferably 1 to 15 μm. If the fiber diameter is less than 1 μm, the reinforcing effect tends to be insufficient, and if it exceeds 15 μm, the product appearance tends to be adversely affected. In addition, the fiber diameter of a fibrous filler can be easily measured with an electron micrograph.

  The inorganic filler may be left untreated, but for the purpose of increasing the affinity with the resin component or the interfacial bond strength, an inorganic surface treatment agent, a derivative such as a higher fatty acid or an ester salt thereof, aminosilane, epoxysilane For the purpose of improving the surface treatment with a coupling agent or the like such as the above, or the handling property, a focusing treatment with an acrylic resin, a urethane resin or the like may be performed. When surface treatment is performed in combination with various surfactants such as nonionic, cation and anionic types, and dispersants such as various resins, the viewpoint of improving mechanical strength and kneadability To preferred. Further, the production method for pulverizing the inorganic filler such as talc from the raw stone is not particularly limited, but from the viewpoint of handling of the inorganic filler, those in an agglomerated state with increased bulk density are preferable. What was granulated using the binder is mentioned as a preferable thing. The blending ratio of the inorganic filler is 1 to 60 parts by weight, preferably 5 to 50 parts by weight, with respect to 100 parts by weight of the total of component A and component B. If the inorganic filler is less than 1 part by weight, the effect of improving the dimensional stability and heat resistance of the resin composition is small, and if it exceeds 60 parts by weight, the fluidity, impact resistance and appearance of the resin composition are deteriorated.

  Furthermore, the conductive thermoplastic resin composition of the present invention may contain various other resin additives in addition to the above components, as long as the effects of the present invention are not impaired. Various resin additives include flame retardants, antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, plasticizers, mold release agents, lubricants, compatibilizers, foaming agents, dyes and pigments, and one or two of them. More than one seed may be added.

Among these additives, in order to suppress the transesterification reaction between the aromatic polycarbonate resin and the polyethylene terephthalate resin, the conductive thermoplastic resin composition preferably contains a heat stabilizer composed of a phosphorus compound. There is also. Preferred examples of the heat stabilizer composed of such a phosphorus compound include various phosphite compounds, phosphonite compounds, and organic phosphates represented by the following formula (1).
O = P (OR) n (OH) 3-n (1)
(In the formula, R is an alkyl group having 10 to 30 carbon atoms, and n is 1 or 2.)

As the phosphite compound, a pentaerythritol type phosphite compound is preferable, distearyl pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-). Preference is given to tert-butyl-4-methylphenyl) pentaerythritol diphosphite. Preferred examples of the phosphonite compound include tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylene-diphosphonite.
The amount of the heat stabilizer composed of the phosphorus compound is 0.5 parts by weight or less, preferably 0.3 parts by weight or less, more preferably 0.1 parts by weight with respect to 100 parts by weight of the total amount of the component A and the component B. Or less.

In the conductive thermoplastic resin composition of the present invention, a resin composition satisfying at least some of the following specifications by the test method described later by blending an appropriate amount of the above-described blending components. However, it is optimal as an electrostatic coating automobile exterior part.
1) Fluidity is 10 × 10 ⁻² cc / s or more in terms of Q value, preferably 13 × 10 ⁻² cc / s or more 2) Surface impact strength is 18 J or more, preferably 20 J or more 3) Heat resistance is load Deflection temperature of 125 ° C. or higher, preferably 130 ° C. or higher 4) Linear expansion coefficient is 8.0 × 10 ⁻⁵ K ⁻¹ or lower, preferably 7.7 × 10 ⁻⁵ K ⁻¹ or lower 5) Heat shrinkage is 0 .40% or less, preferably 0.30% or less 6) Among them, a resin composition satisfying the following specifications is preferable in terms of electrostatic coating, among which the volume resistivity is 1 × 10 ⁸ Ωcm or less. .
1) Load deflection temperature is 125 ° C or higher (however, the measurement method is based on ASTM D648)
2) Heat shrinkage is 0.40% or less (however, the measurement method was evaluated by aging in a hot air oven at 120 ° C. for 40 minutes for a 100 mmφ disk-shaped molded product (thickness 3 mm)).
3) Volume resistivity is 1 × 10 ⁸ Ωcm or less (however, the test method is obtained by cutting both ends of ASTM No. 2 dumbbell test piece (thickness 3.2 mm) so that the length is 50 mm and cutting. After applying a silver paste to both end faces and drying at room temperature, the resistance value (RL: unit Ω) between the both end faces was measured with a tester, and the volume resistivity R (unit: Ωcm) was calculated from the following formula: Calculated.
R = RL × AL / L
(In the formula, AL means the cross-sectional area (unit: cm ² ) of the test piece, and L means the length (unit: cm) of the test piece.)}

Next, the method for preparing the conductive thermoplastic resin composition of the present invention in which the A component constitutes the continuous phase (sea phase) and the C component mainly exists in the B component that constitutes the discontinuous phase (island phase). Is not particularly limited, but from an industrial viewpoint, a melting and kneading method is preferable.
As a typical method of melt-kneading, use of a melt-kneader generally used for thermoplastic resins can be mentioned. For example, a single-screw extruder, a multi-screw extruder, a Banbury mixer, a roll, a Brabender plastogram, and the like can be mentioned. After melt-kneading with a melt-kneader, the mixture is granulated.
As a specific method, there is a method in which the A component, the B component, and the C component are mixed in advance together with the D component as necessary, and are collectively introduced into a melt kneader to obtain a resin composition by melt kneading. . However, the A component and the B component are mixed in advance together with the D component as required, and are added to the upstream portion of the melt kneader at once, melt kneaded, and then the C component in the portion after the middle stream of the melt kneader. Is preferable from the viewpoint of conductivity. In addition, the remainder of component A and component B are blended with component D as necessary in an intermediate composition in which component C is melt-kneaded with at least part of component A in advance, and a resin composition is obtained by melt-kneading. This is a preferable method in terms of conductivity.

In addition, the above components A to D are added to an appropriate solvent, for example, hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and derivatives thereof, regardless of the melting / kneading method. It is also possible to prepare the conductive thermoplastic resin composition of the present invention by a solution mixing method in which dissolved components or dissolved components and insoluble components are mixed in a suspended state.
When manufacturing automobile exterior parts and the like from the conductive thermoplastic resin composition of the present invention, conventionally known methods for molding thermoplastic resins can be used. Examples of the molding method include an injection molding method, an injection compression molding method, a hollow molding method, an extrusion molding method, a sheet molding method, a thermoforming method, a rotational molding method, and a laminate molding method.

  EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these ranges. In the following examples and comparative examples, the blending amount means parts by weight.

In obtaining each resin composition of Examples and Comparative Examples, the following raw materials were prepared.
Component A PC-1: Bisphenol A type aromatic polycarbonate, manufactured by Mitsubishi Engineering Plastics Co., Ltd., Iupilon S-3000FN, viscosity average molecular weight 22,500 (hereinafter abbreviated as PC-1).
PC-2: Bisphenol A type aromatic polycarbonate, manufactured by Mitsubishi Engineering Plastics Co., Ltd., Iupilon H-4000FN, viscosity average molecular weight 15,500 (hereinafter abbreviated as PC-2).

B component PET-1: Polyethylene terephthalate resin, manufactured by Mitsubishi Chemical Corporation, Novapeps GG500, measured by dissolving at a concentration of 1% by weight in a one-to-one (weight ratio) mixture of phenol and tetrachloroethane at a temperature of 30 ° C. The intrinsic viscosity was 0.76 dl / g and the terminal carboxyl group amount was 15 eq / t (hereinafter abbreviated as PET-1).
PET-2: Polyethylene terephthalate resin, manufactured by Mitsubishi Rayon Co., Ltd., Dianite PA-200D, dissolved in a 1 to 1 (weight ratio) mixture of phenol and tetrachloroethane at a temperature of 30 ° C. to a concentration of 1% by weight. The measured intrinsic viscosity was 1.09 dl / g, and the terminal carboxyl group amount was 14 eq / t (hereinafter abbreviated as PET-2).
Other than B component (comparative example)
PBT-1: Polybutylene terephthalate resin, manufactured by Mitsubishi Engineering Plastics Co., Ltd., Novaduran 5020-C, dissolved in a one-to-one (weight ratio) mixture of phenol and tetrachloroethane at a temperature of 30 ° C. to a concentration of 1% by weight The intrinsic viscosity measured in this way was 1.20 dl / g (hereinafter abbreviated as PBT-1).
PBT-2: Polybutylene terephthalate resin, manufactured by Mitsubishi Engineering Plastics Co., Ltd., Novaduran 5008-C, dissolved in a one-to-one (weight ratio) mixture of phenol and tetrachloroethane at a temperature of 30 ° C. to a concentration of 1% by weight The intrinsic viscosity measured in this way was 0.85 dl / g (hereinafter abbreviated as PBT-2).

C component CB1: conductive carbon black, manufactured by Lion Corporation, Ketjen black EC, BET nitrogen adsorption specific surface area 800 m ² / g, dibutyl phthalate oil absorption 360 ml / 100 g (hereinafter abbreviated as CB1).
PC / 15BN: Hollow carbon fibril, manufactured by Hyperion Catalysis Co., Ltd., PC / 15BN, 85% polycarbonate and 15% hollow carbon fibril (graphite fibril BN) having an outer diameter of 15 nm, an inner diameter of 5 nm, and a length of 100 to 10,000 nm. Master batch (hereinafter abbreviated as PC / 15BN).
PC / CB1: PC-1 / 90 weight from barrel 1 using a twin screw extruder (manufactured by Nippon Steel, TEX44, L / D = 42) under the conditions of a cylinder temperature of 280 ° C. and a screw speed of 300 rpm. The parts were fed to an extruder and melt kneaded, and the CB / 10 parts by weight were fed from the barrel 7 to the extruder and melt kneaded to prepare a master batch (hereinafter abbreviated as PC / CB1).
Other than C component (comparative example)
CB2: conductive carbon black, manufactured by Lion Corporation, Ketjen Black EC600JD, BET nitrogen adsorption specific surface area 1270 m ² / g, dibutyl phthalate oil absorption 495 ml / 100 g (hereinafter abbreviated as CB2).
CB3: Conductive carbon black, manufactured by Mitsubishi Chemical Corporation, Mitsubishi Carbon Black MA100, BET nitrogen adsorption specific surface area 110 m ² / g, dibutyl phthalate oil absorption 100 ml / 100 g (hereinafter abbreviated as CB3).

D component Rubber polymer: Core / shell type graft copolymer comprising butadiene (core) / alkyl acrylate / alkyl methacrylate copolymer (shell), manufactured by Kureha Chemical Industry Co., Ltd., Paraloid EXL2603 (hereinafter, referred to as the rubber polymer)
Other components Talc: Compression talc, Hayashi Kasei Co., Ltd., UPN HST0.5, primary (before compression) average particle size 2.7 μm (hereinafter abbreviated as talc)
Phosphorus compound heat stabilizers: organophosphate / formula _{[O = P (OC 18 H} 37) n (OH) 3-n], the compound represented by (a mixture of n = 1 and 2), Asahi Denka ( ADK STAB AX-71 (hereinafter abbreviated as heat stabilizer)

[Preparation of test piece]
The resin composition was injection molded under the conditions of a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C. using an injection molding machine (Toshiba IS150) to produce an ASTM test piece and a 100 mmφ disk-shaped molded product (thickness 3 mm). .

[Evaluation methods]
(1) Fluidity (Q value)
Using a high load flow tester, the flow rate Q value (unit: cc / s) per unit time of the composition was measured under the conditions of 280 ° C. and a load of 160 kgf / cm ² to evaluate the fluidity. An orifice having a diameter of 1 mm and a length of 10 mm was used.
(2) Impact resistance a. Surface impact strength A 100 mmφ disk-shaped molded product (thickness 3 mm) was coated as follows.
V top (made by Dainippon Paint Co., Ltd.) 80 parts by weight, V top curing agent 20 parts by weight, V top thinner 40 parts by weight diluted with spray gun (Anest Iwata W77) After coating on the surface of the disk-shaped molded article, it was dried at room temperature for 10 minutes and then baked at 120 ° C. for 40 minutes in a hot air oven. The coating thickness was about 30 μm.
This coated disk-shaped molded article was subjected to a punching impact test using a high-rate impact tester (manufactured by Shimadzu Corporation) at a punch diameter of 1/2 inch, a support diameter of 3 inches, and a punching speed of 5 m / s. The greater the surface impact strength (fracture energy, unit: J), the better the impact resistance.
Furthermore, as for the fracture appearance in the punching impact test, ◎ for those with ductile fracture without fragment scattering, ○ for those with very little fragment scattering, △ for those with fragment scattering, and fragments severely scattered. A brittle fracture was evaluated as x.
b. Izod impact strength Measured at 23 ° C. using a notched specimen having a thickness of 3.2 mm in accordance with ASTM D256.

(3) Heat resistance (load deflection temperature: DTUL)
In accordance with ASTM D648, the heat distortion temperature (unit: ° C.) was measured at 0.45 MPa.
(4) Dimensional stability (linear expansion coefficient and heat shrinkage)
a. Linear expansion coefficient The linear expansion coefficient (unit: K < ^-1 >) was measured based on ASTM D696. However, the measurement temperature range was 23 to 80 ° C.
b. Heat Shrinkage A 100 mmφ disk shaped product (thickness 3 mm) was aged in a 120 ° C. hot air oven for 40 minutes to evaluate the heat shrinkage (unit:%). The measurement was performed at 23 ° C., and the dimensional average value in the resin flow direction and the perpendicular direction was determined as a dimensional change before and after aging. The smaller this value, the smaller the dimensional change during heating during coating, and the better the dimensional stability.

(5) Conductivity (volume resistivity)
Cut both ends of a parallel part of ASTM No. 2 dumbbell test piece (thickness: 3.2 mm) to a length of 50 mm, apply silver paste to both end faces generated by the cutting, and dry at room temperature. The resistance value (RL: unit Ω) between the both end faces was measured, and the volume resistivity R (unit: Ωcm) was calculated from the following equation.
R = RL × AL / L
(In the formula, AL means the cross-sectional area of the test piece (unit: cm ² ), and L means the length of the test piece (unit: cm).)
(6) Appearance The surface appearance of the disk-shaped molded product was visually observed and evaluated as “◯” when there was no aggregate, “Δ” when there was a little aggregate, and “×” when there was a lot of aggregate.

[Micromorphological observation]
Using the ultramicrotome (ULTRACUT CUT manufactured by Leica Co., Ltd.) equipped with a cryo device (REICHERT-NSSEI FCS) from the pellet of the composition, an ultrathin section having a thickness of 100 nm was prepared at −100 ° C. using a diamond knife. The specimen was stained with ruthenium tetroxide (RuO4), and the micro morphology was observed with a transmission electron microscope (manufactured by JEOL Ltd., model: JEM1200EXII type).

[Examples 1 to 9 and Comparative Examples 1 to 8]
A component, B component, other than B component, D component, and other components are uniformly mixed in the ratio shown in Table 1 and Table 2 with a tumbler mixer, and then a twin screw extruder (manufactured by Nippon Steel Works, TEX30XCT, L / D = 42, barrel number 12), cylinder temperature 260 ° C., screw rotation speed 200 rpm, feed from barrel 1 to extruder and melt knead. The composition was prepared by feeding to an extruder halfway and melting and kneading at the ratio shown in FIG. The obtained physical properties are shown in Tables 1 and 2.

[Examples 10 and 11]
After mixing A component, B component, C component (masterbatch) and D component uniformly with a tumbler mixer in the ratio shown in Table 1, a twin screw extruder (manufactured by Nippon Steel Works, TEX30XCT, L / D = 42, Using a barrel number of 12), a composition was prepared by feeding from the barrel 1 to an extruder at a cylinder temperature of 260 ° C. and a screw speed of 200 rpm, and melt-kneading. The obtained physical properties are shown in Table 1.

[Example 12]
A component, B component, C component and D component were uniformly mixed with a tumbler mixer in the proportions shown in Table 1, and then a twin screw extruder (Nippon Steel Works, TEX30XCT, L / D = 42, barrel number 12) Was used to feed the extruder all at once from the barrel 1 at a cylinder temperature of 260 ° C. and a screw rotation speed of 200 rpm, and melt-kneaded to prepare a composition. The obtained physical properties are shown in Table 1.

[Description of Examples and Comparative Examples]
(1) The composition of Examples 1-12 is excellent in electroconductivity, is excellent in fluidity | liquidity, impact resistance, heat resistance, dimensional stability, and the balance of an external appearance, and is conductive heat for manufacture, such as automotive exterior parts. It is suitable as a plastic resin composition.
(2) The compositions of Comparative Examples 1 to 3 in which the B component polyethylene terephthalate is replaced with polybutylene terephthalate are inferior in conductivity, heat resistance, and dimensional stability compared to the compositions in Examples. I understand.
(3) It turns out that the composition of the comparative example 4 which replaced CB1 of C component with CB2 whose specific surface area exceeds the range of this patent is inferior in fluidity | liquidity and an external appearance.
(4) It turns out that the composition of the comparative example 5 which replaced CB1 of C component with CB3 whose specific surface area is less than the range of this patent is inferior to electroconductivity.
(5) It can be seen that the composition of Comparative Example 6 in which the addition amount of component C is outside the scope of this patent is inferior in fluidity, impact resistance, and appearance as compared with the compositions of the examples.
(6) The composition of Comparative Examples 7 and 8 in which the blending ratio of the A component and the B component deviates from the scope of this patent is inferior in conductivity compared to the composition of the Example, and the composition of Comparative Example 8 is It can be seen that it is inferior in impact resistance, dimensional stability and appearance.
(7) In the micro form, the composition mainly present in the B component in which the A component forms the sea phase, the B component forms the island phase, and the C component forms the island phase is excellent in conductivity and impact resistance. It can be seen that the dimensional stability and the balance of appearance are excellent.

Claims (4)

(A) Aromatic polycarbonate resin (component A) 51 to 90 parts by weight, and (B) polyethylene terephthalate resin (component B) 10 to 49 parts by weight.
(C) Conductive carbon black and / or hollow carbon fibrils (component C) 0.1 to 150 having a specific surface area (BET nitrogen adsorption method) of 150 to 1000 m ² / g and a dibutyl phthalate oil absorption of 100 to 450 ml / 100 g 5 parts by weight Ri name by blending, moreover,
The A component constitutes a continuous phase (hereinafter referred to as “sea phase”), the B component constitutes a discontinuous phase (hereinafter referred to as “island phase”), has a sea-island structure micro-form, and the C component More than half of the B component that constitutes the island phase, and
A conductive thermoplastic resin composition characterized by satisfying the following specifications .
1) Load deflection temperature is 125 ° C or higher (however, the test method is based on ASTM D648)
2) Heat shrinkage rate is 0.40% or less (however, the test method was evaluated by aging for 40 minutes in a 120 ° C. hot air oven for a 100 mmφ disk-shaped molded product (thickness 3 mm)).
3) Volume resistivity is 1 × 10 ⁸ Ωcm or less (however, the test method is obtained by cutting both ends of ASTM No. 2 dumbbell test piece (thickness 3.2 mm) at both ends so that the length is 50 mm and cutting. After applying a silver paste to both end faces and drying at room temperature, the resistance value (RL: unit Ω) between the both end faces was measured with a tester, and the volume resistivity R (unit: Ωcm) was calculated from the following formula: Calculated.
R = RL × AL / L
(Wherein, AL is the cross-sectional area of the specimen (unit: cm to ^2), L is the length of the test piece (unit:. Cm) means a)} to Rukoto conductive thermoplastic characterized by Resin composition. (D) The rubber polymer (D component) is blended at a ratio of 0.5 to 30 parts by weight with respect to a composition comprising 100 parts by weight of the total of A component and B component. Item 2. The conductive thermoplastic resin composition according to Item 1 . Advance A and B components, together with the D component needed to melt-kneading, the claims 1-2, characterized in that is obtained by blending and melt-kneading the C component in the melt-kneaded product The conductive thermoplastic resin composition according to any one of the above. An intermediate composition obtained by melt-kneading C component with at least a part of A component in advance is obtained by melt-kneading the remainder of A component and B component together with D component as necessary. conductive thermoplastic resin composition according to any one of claims 1-2.