Thermoplastic resin composition

Abstract: A thermoplastic resin composition having well-balanced properties which comprises 95-5 weight % of polycarbonate, 5-95 weight % of polyolefin and a particular combination of additional components selected from an unsaturated carboxylic acid-modified polyolefin, polybutylene terephthalate, an oxazoline ring-containing styrene copolymer, a saponified olefin-vinyl ester copolymer and an epoxy group-containing styrene copolymer.

Description: BACKGROUND OF THE INVENTION The present invention relates to a thermoplastic resin composition with good mechanical strength, impact resistance, thermal deformation resistance, moldability and chemical resistance comprising crystalline polyolefin, polycarbonate and additive components. Aromatic polycarbonates have excellent impact strength, heat resistance, rigidity and dimension stability, but they are poor in solvent resistance and moldability. To overcome these problems, attempts have been made to provide polycarbonate compositions with polyolefins. However, since polyolefins and polycarbonates do not have good compatibility, proposals have been made to add various third components to improve their compatibility. Japanese Patent Laid-Open No. 57-108151 discloses a polycarbonate resin composition comprising 100 parts by weight of a polycarbonate resin, 0.3-20 parts by weight of polyethylene and 0.3-20 parts by weight of a butyl rubber. Japanese Patent Laid-Open No. 57-108152 discloses a polycarbonate resin composition comprising 0.3-20 parts by weight of an ethylene-propylene copolymer and/or an ethylene-propylene-diene copolymer as a third component. Japanese Patent Laid-Open No. 57-111351 discloses a polycarbonate resin composition comprising 0.3-20 parts by weight of an isoprene rubber and/or a methylpentene polymer as a third component. Any of these polycarbonate resin compositions, however, suffers from drastic decrease in impact strength when polyethylene content exceeds 10 %, resulting in the surface peel of molded products. Further, there are various proposals in adding third components. For instance, Japanese Patent Laid-Open Nos. 56-76449 and 59-133247 disclose thermoplastic resin compositions comprising polycarbonate, polyolefin and an ABS resin. However, the ABS resin do not have sufficient effects of increasing compatibility, so when polyolefin exceeds 10 %, the thermoplastic resin compositions lose mechanical strength. Japanese Patent Laid-Open No. 59-196360 discloses a polycarbonate resin composition comprising as a third component a copolymer of at least one olefin and an acrylate, methacrylate, acrylic acid or methacrylic acid monomer, for instance, an ethylene-ethyl acrylate copolymer (EEA resin). Japanese Patent Laid-Open No. 61-215649 discloses a polycarbonate resin composition comprising as a third component an olefin-vinyl ester copolymer, for instance, an ethylene-vinyl acetate copolymer (EVA resin). However, these compositions also suffer from decrease in impact strength due to the decrease in compatibility when the amount of polyolefin nears that of polycarbonate. Japanese Patent Laid-Open No. 61-115945 discloses a composition comprising a styrene-ethylene·butylene-styrene block copolymer (SEBS resin) as a third component. However, the addition of the SEBS resin fails to provide sufficient rigidity, thermal deformation resistance, impact strength, and surface peel resistance, though the compatibility is slightly improved. Japanese Patent Publication Nos. 51-24540 and 51-41145 and Japanese Patent Laid-Open No. 60-233151 disclose thermoplastic resin compositions comprising polycarbonate and a graft copolymer produced by grafting a styrene monomer and acrylonitrile monomer to an ethylene-propylene-diene copolymer (AES resin). However, since none of these thermoplastic resin compositions contains polyolefin, they are poor in moldability. In addition, Japanese Patent Laid-Open Nos. 61-159447, 61-120852, 61-225245, 61-235456 and 61-238847 disclose compositions comprising aromatic polycarbonate, polyester and/or modified polyolefin. Further, Japanese Patent Laid-Open No. 49-76948 discloses a thermoplastic resin composition comprising polycarbonate and a styrene-maleic anhydride copolymer. However, since no polyolefin is contained in these compositions, they are poor in solvent resistance. US 4579910 discloses a resin composition comprising a polycarbonate; an olefin - vinyl ester copolymer and either a polyolefin or an olefin - vinyl alcohol copolymer. Japanese Patent Laid - Open No 62-177047 discloses a resin composition comprising a mixture of (a) an ethylene polymer modified with an ethylenically unsaturated carboxylic acid or an anhydride thereof and a metal compound such as a hydroxide and salts of group IA or IIA metals or a mixture of a metal compound and an ethylene polymer; (b) a saponified ethylene - vinyl acetate copolymer; and (c) a hydrophobic thermoplastic resin. As described above although thermoplastic resin compositions based on polycarbonate and polyolefin whose compatibility is improved to have an excellent balance of mechanical strength, moldability and solvent resistance are desired particularly for automobile parts, etc., satisfactory compositions have never been provided. OBJECT AND SUMMARY OF THE INVENTION An object of the present invention is, therefore, to increase the compatibility between polycarbonate and polyolefin, thereby not only improving impact strength, thermal deformation resistance, moldability and chemical resistance but also preventing surface peel. Another object of the present invention is to provide a polycarbonate resin composition having a well-balanced combination of mechanical strength, moldability, and solvent resistance with improved compatibility between. polycarbonate and polyolefin. As a result of intense research in view of the above objects, it has been found that particular additive components as described below can drastically improve the compatibility between polycarbonate and polyolefin, thereby providing thermoplastic resin compositions with excellent mechanical strength, impact resistance, thermal deformation resistance, moldability, and solvent resistance. The present invention has been completed based on this finding. The thermoplastic resin composition according to a first embodiment of the present invention comprises (a) 95-5 weight % of crystalline polyolefin having a crystallinity of 20% or more measured by an X-ray diffraction method, (b) 5-95 weight % of polycarbonate, (c) 2-100 parts by weight, per 100 parts by weight of said (a) and said (b), of a polyolefin modified with unsaturated carboxylic acid or its anhydride, the content of said unsaturated carboxylic acid or its anhydride in the modified polyolefin being 0.1-10 weight %, and (d) 2-100 parts by weight, per 100 parts by weight of said (a) and said (b), of polybutylene terephthalate. The thermoplastic resin composition according to a second embodiment of the present invention comprises (a) 95-5 weight % of crystalline polyolefin having a crystallinity of 20% or more measured by an X-ray diffraction method, (b) 5-95 weight % of polycarbonate (c) 2-30 parts by weight, per 100 parts by weight of said (a) and said (b), of a polyolefin modified with unsaturated carboxylic acid or its anhydride, the content of said unsaturated carboxylic acid or its anhydride in the modified polyolefin being 0.1-10 weight %, and (d) 2-30 parts by weight, per 100 parts by weight of said (a) and said (b), of an oxazoline ring-containing copolymer comprising an oxazoline ring-containing monomer and a styrene monomer, the content of said oxazoline ring-containing monomer in said oxazoline ring-containing copolymer being 0.1-10 weight %. The thermoplastic resin composition according to a third embodiment of the present invention consists essentially of (a) 95-5 weight % of a crystalline polyolefin having a crystallinity of 20% or more measured by an X-ray diffraction method, (b) 5-95 weight % of polycarbonate, (c) 2-30 parts by weight, per 100 parts by weight of said (a) and said (b), of a polyolefin, modified with unsaturated carboxylic acid or its anhydride, the content of said unsaturated carboxylic acid or its anhydride in the modified polyolefin being 0.1-10 weight % and (d) 2-100 parts by weight, per 100 parts by weight of said (a) and said (b), of a saponified olefin-vinyl ester copolymer having a saponification degree of 50% or more, the content of the vinyl ester in said saponified olefin-vinyl ester copolymer being 10-70 weight %. The thermoplastic resin composition according to a fourth embodiment of the present invention comprises (a) 95-5 weight % of crystalline polyolefin having a crystallinity of 20% or more measured by an X-ray diffraction method, (b) 5-95 weight % of polycarbonate, (c) 2-30 parts by weight, per 100 parts by weight of said (a) and said (b), of a polyolefin modified with unsaturated carboxylic acid or its anhydride, the content of said unsaturated carboxylic acid or its anhydride in the modified polyolefin being 0.1-10 weight%, and (d) 2-30 parts by weight, per 100 parts by weight of said (a) and said (b), of an epoxy group-containing styrene copolymer comprising a copolymer composed of an unsaturated epoxy compound and a styrene monomer, the content of said unsaturated epoxy compound being 1-50 mol%. DETAILED DESCRIPTION OF THE INVENTION Polycarbonates, particularly aromatic polycarbonates which can be used in the present invention may be produced by (a) a reaction between bivalent phenol and a carbonate precursor such as phosgene in the presence of an acid acceptor and a molecular weight modifier, or (b) a transesterification reaction between bivalent phenol and a carbonate precursor such as diphenyl carbonate. The bivalent phenols which can be used are preferably bisphenols, particularly 2,2-bis (4-hydroxyphenyl) propane (bisphenol A). Part or total of bisphenol A may be replaced by other bivalent phenols. The other bivalent phenols than bisphenol A include hydroquinone, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) alkane, bis (4-hydroxyphenyl) cycloalkane, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) ether, and halogenated bisphenols such as bis (3,5-dibromo-4-hydroxyphenyl) propane. Homopolymers or copolymers of these bivalent phenols or their mixtures may also be used. Such polycarbonate resins are commercially available. The aromatic polycarbonate preferably has a weight-average molecular weight of 10,000-100,000. When it is less than 10,000, sufficient mechanical properties cannot be provided, and when it exceeds 100,000, the moldability decreases. The more preferable weight-average molecular weight is 20,000-50,000. Crystalline polyolefins which can be used in the present invention include polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1 and other α-olefin polymers, and the preferred polyolefin is polypropylene. Incidentally, the polyolefin need not be a homopolymer. For instance, in the case of polypropylene, it may be a copolymer of propylene with up to 20 weight % of other one or more α-olefins. The preferred comonomers for the propylene copolymer include ethylene. The copolymers may be random copolymers, block copolymers or graft copolymers. The weight-average molecular weight of the polyolefin is 10,000-1,000,000, and preferably 30,000-300,000. Further, it has a melt flow rate (MFR) of 500-0.01 g/10 min at 230°C, and preferably 50-1 g/10 min. When measured by an X-ray diffraction method, the polyolefin has a crystallinity of 20% or more. When the crystallinity is less than 20%, the resulting thermoplastic resin composition has low mechanical strength. The preferred crystallinity is 40 % or more. In the present invention, a weight ratio of the crystalline polyolefin to the polycarbonate is 95-5% to 5-95%. When the polycarbonate is less than 5 weight %, sufficient impact strength and mechanical strength cannot be obtained, and when it exceeds 95 weight %, the moldability and the solvent resistance decrease. Preferably, the polyolefin is 90-10 weight %, and the polycarbonate is 10-90 weight %. More preferably, the polyolefin is 80-20 weight %, and the polycarbonate is 20-80 weight %. The thermoplastic resin composition according to the first embodiment of the present invention is characterized by comprising the modified polyolefin and polybutylene terephthalate as third and fourth components. The modified polyolefin is a polyolefin modified with unsaturated carboxylic acid or its anhydride. The unsaturated carboxylic acids or anhydrides thereof include monocarboxylic acids such as acrylic acid, methacrylic acid, dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, dicarboxylic anhydrides such as maleic anhydride, itaconic anhydride, Particularly, dicarboxylic acid or an anhydride thereof is preferable. The polyolefins which are modified with the unsaturated carboxylic acid or its anhydride include homopolymers of olefins such as polyethylene, polypropylene, polybutene-1, polypentene-1, and copolymers of different olefins or those of olefins and diolefins, such as an ethylene-propylene copolymer, an ethylene-butene-1 copolymer, a propylene-butene-1 copolymer, an ethylene-vinyl acetate copolymer, a propylene-vinyl acetate copolymer, an ethylene-butadiene copolymer, an ethylene-isoprene copolymer, an ethylene-chloroprene copolymer, a propylene-butadiene copolymer, an ethylene-propylene-diene copolymer. The copolymers may be random copolymers, block copolymers, graft copolymers or alternating copolymers. The modified polyolefin preferably does not contain unreacted monomers and has a weight-average molecular weight of 10,000 or more. The more preferable weight-average molecular weight is 30,000-300,000. The content of the unsaturated carboxylic acid or its anhydride in the modified polyolefin is preferably 0.1-10 weight %. When it is less than 0.1 weight %, the addition of the modified polyolefin does not sufficiently increase the compatibility of the aromatic polycarbonate and the polyolefin. On the other hand, when it exceeds 10 weight %, its compatibility with polyolefin decreases. The more preferable amount of the unsaturated carboxylic acid or its anhydride is 0.5-5 weight %. The production of the modified polyolefin can be conducted by a solution method or a melt blending method. In the case of the melt blending method, the polyolefin, the unsaturated carboxylic acid (or anhydride) and a catalyst are charged into an extruder or a double-screw kneader (extruder) and kneaded while heating at 150-250°C. In the case of the solution method, the above starting materials are dissolved in an organic solvent such as xylene, and stirred at a temperature of 80-140°C. In any case, the catalyst may be a usual radical polymerization catalyst selected from peroxides such as benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, acetyl peroxide, tert-butyl perbenzoate, dicumyl peroxide, perbenzoic acid, peracetic acid, tert-butyl perpivalate, azo compounds such as azobisisobutyronitrile. The amount of the catalyst may be 1-100 parts by weight per 100 parts by weight of the unsaturated carboxylic acid or anhydride thereof. The polybutylene terephthalate is a polyester composed of terephthalic acid and 1,4-butylene glycol, which has an intrinsic viscosity [η] of about 0.5-2.0, which is determined from a solution viscosity measured in a phenol/tetrachloroethane mixed solvent (50/50 by weight %) at 30°C. -The terephthalic acid component may be substituted by an alkyl group, a halogen group, and the glycol component may contain, in addition to 1,4-butylene glycol, up to 20 weight % of other glycols such as ethylene glycol, propylene glycol, hexamethylene glycol. The amount of the modified polyolefin added is 2-100 parts by weight per 100 parts by weight of the aromatic polycarbonate + the polyolefin. When it is less than 2 parts by weight, the addition of the modified polyolefin does not have sufficient effect of improving the compatibility between the aromatic polycarbonate and the polyolefin. On the other hand, when it exceeds 100 parts by weight, the mechanical properties such as impact strength is lowered. The preferred amount of the modified polyolefin is 5-50 parts by weight. The amount of the polybutylene terephthalate is 2-100 parts by weight per 100 parts by weight of the aromatic polycarbonate + the polyolefin. When it is less than 2 parts by weight, the addition of the polybutylene terephthalate does not have sufficient effect of improving the compatibility between the aromatic polycarbonate and the polyolefin. On the other hand, when it exceeds 100 parts by weight, the mechanical properties such as impact strength is lowered. The preferred amount of the polybutylene terephthalate is 5-50 parts by weight. The thermoplastic resin composition of this embodiment may further contain up to 100 parts by weight of rubber components such a low-crystallinity ethylene-α-olefin copolymer, an acrylic elastomer, a butyl rubber, per 100 parts by weight of the crystalline polyolefin + the polycarbonate. The polycarbonate and the polyolefin does not have good compatibility, but the modified polyolefin is highly compatible with the polyolefin. In addition, the polycarbonate is compatible with the polybutylene terephthalate by a transesterification reaction therebetween in the process of blending. Further, a reaction takes place between the carboxylic groups of the modified polyolefin and the -OH end groups of the polybutylene terephthalate to generate a graft copolymer. These reactions contribute to the compatibility of the polycarbonate with the polyolefin. Accordingly, by blending the polycarbonate, the polyolefin, the modified polyolefin and the polybutylene terephthalate, good compatibility between the polycarbonate and the polyolefin can be achieved, thereby providing the thermoplastic resin composition with a good balance of mechanical properties, moldability, solvent resistance. The thermoplastic resin composition according to the second embodiment of the present invention is characterized by containing the modified polyolefin and the oxazoline ring-containing styrene copolymer as third and fourth components. The modified polyolefin in this embodiment may be the same as in the first embodiment. The oxazoline ring-containing styrene copolymer is based on an oxazoline ring-containing monomer and a styrene monomer. The oxazoline ring-containing monomer has a vinyl group bonded to an oxazoline ring, a typical example of which is shown by the following formula: wherein R 1 and R 2 are respectively a hydrogen atom or an alkyl group and n is an integer of 2 or 3. Specific examples of the oxazoline ring-containing monomer are 2-isopropenyl-2-oxazoline shown by the following formula (2), 2-isopropenyl-4,4-dimethyl-2-oxazoline shown by the following formula (3), and other vinyl oxazolines. With respect to the styrene monomer, it may be selected from styrene, α methylstyrene, α chlorostyrene or dimethylstryene, although styrene is particularly preferable. The amount of the oxazoline ring-containing monomer is 0.1-10 weight %. When the monomer is less than 0.1 weight %, the oxazoline ring to be cross-linked with the modified polyolefin is insufficient, failing to contribute to the improvement of the compatibility between the polycarbonate and the polyolefin. On the other hand, when it exceeds 10 weight %, the oxazoline ring-containing monomer becomes too reactive, causing the decrease in flowability due to cross-linking. The preferred amount of oxazoline ring-containing monomer is 0.2-3 weight %. Besides the oxazoline ring-containing monomer and the styrene monomer, the oxazoline ring-containing styrene copolymer may contain radical-polymerizable monomers. Such radical-polymerizable monomers include acrylonitrile, (meth)acrylates. The amount of the radical-polymerizable monomers is up to 50 weight %, substituting for the styrene monomer. The oxazoline ring-containing styrene copolymer can be produced from the above starting materials in the presence of a radical polymerization catalyst. When the copolymerization reaction is conducted in a solution, toluene, is used as a solvent and the solution is heated at 40-120°C while stirring. The content of the modified polyolefin is 2-30 parts by weight per 100 parts by weight of the aromatic polycarbonate+ the polyolefin. When it is less than 2 parts by weight, sufficient effect of improving the compatibility between the aromatic polycarbonate and the polyolefin cannot be provided by the addition of the modified polyolefin. On the other hand, when it exceeds 30 parts by weight, the resulting composition has low mechanical properties such as impact resistance. The preferred amount of the modified polyolefin is 5-15 parts by weight in this embodiment. The content of the oxazoline ring-containing styrene copolymer is 2-30 parts by weight per 100 parts by weight of the aromatic polycarbonate + the polyolefin. When it is less than 2 parts by weight, sufficient effect of improving the compatibility between the aromatic polycarbonate and the polyolefin cannot be provided by the addition of the oxazoline ring-containing styrene copolymer. On the other hand, when it exceeds 30 parts by weight, the resulting composition has low mechanical properties such as impact resistance. The preferred amount of the oxazoline ring-containing styrene copolymer is 5-15 parts by weight in this embodiment. The thermoplastic resin composition of this embodiment may further contain up to 100 parts by weight of rubber components such a low-crystallinity ethylene-α-olefin copolymer, an acrylic elastomer, a butyl rubber, per 100 parts by weight of the crystalline polyolefin + the polycarbonate. The oxazoline ring-containing styrene copolymer has a high affinity for the aromatic polycarbonate, and a reaction takes place between the carboxylic groups of the modified polyolefin and the oxazoline groups of the oxazoline ring-containing styrene copolymer to generate a graft copolymer. These reactions contribute to the compatibility of the polycarbonate with the polyolefin. Accordingly, by blending the polycarbonate, the polyolefin, the modified polyolefin and the oxazoline ring-containing styrene copolymer, good compatibility between the polycarbonate and the polyolefin can be achieved, thereby providing the thermoplastic resin composition with a good balance of mechanical properties, moldability, solvent resistance. The thermoplastic resin composition according to the third embodiment of the present invention is characterized by containing the modified polyolefin and the saponified olefin-vinyl ester copolymer as third and fourth components. The modified polyolefin in this embodiment may be the same as in the first embodiment. The saponified olefin-vinyl ester copolymer is composed of a lower α-olefin and vinyl ester. The preferred lower α-olefin is ethylene. The vinyl ester copolymerized with the lower α-olefin is a vinyl ester monomer shown by the following general formula: CH 2 = CHOCOR 3 wherein R 3 is an alkyl group having 1 - 10 carbon atoms or an aryl group having 6 - 12 carbon atoms. Specific examples of the vinyl esters are vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, and particularly preferable among them is vinyl acetate. The content of the vinyl ester in the above saponified olefin-vinyl ester copolymer is 10-70 weight %. When it is less than 10 weight %, or when it exceeds 70 weight %, sufficient effect of improving the compatibility between the aromatic polycarbonate and the polyolefin cannot be provided. The preferred amount of the vinyl ester is 25-60 weight %. The saponification degree of the saponified olefin-vinyl ester copolymer is 50% or more. When it is less than 50%, the saponified olefin-vinyl ester copolymer has an insufficient amount of hydroxy groups to be bonded to the carboxylic groups of the modified polyolefin, failing to provide sufficient effect of improving the compatibility between the aromatic polycarbonate and the polyolefin. The preferred saponification degree is 70% or more. Incidentally, the saponification of the copolymer can be conducted by a usual method, for instance, by heating a copolymer's aqueous solution at 50-90°C, if necessary, in the presence of alkali such as sodium hydroxide. The content of the modified polyolefin is 2-30 parts by weight per 100 parts by weight of the aromatic polycarbonate + the polyolefin. When it is less than 2 parts by weight, sufficient effect of improving the compatibility between the aromatic polycarbonate and the polyolefin cannot be provided by the addition of the modified polyolefin. On the other hand, when it exceeds 30 parts by weight, the resulting composition has low mechanical properties such as impact resistance. The preferred amount of the modified polyolefin is 5-20 parts by weight in this embodiment. The content of the saponified olefin-vinyl ester copolymer is 2-100 parts by weight per 100 parts by weight of the aromatic polycarbonate + the polyolefin. When it is less than 2 parts by weight, sufficient effect of improving the compatibility between the aromatic polycarbonate and the polyolefin cannot be provided by the addition of the saponified olefin-vinyl ester copolymer. On the other hand, when it exceeds 100 parts by weight, the resulting composition has low rigidity. The preferred amount of the saponified olefin-vinyl ester copolymer is 5-50 parts by weight in this embodiment. The thermoplastic resin composition of this embodiment may further contain up to 100 parts by weight of rubber components such a low-crystallinity ethylene-α-olefin copolymer, an acrylic elastomer, or a butyl rubber; per 100 parts by weight of the crystalline polyolefin + the polycarbonate. The saponified olefin-vinyl ester copolymer has a high affinity for the aromatic polycarbonate, and a reaction or hydrogen bonding takes place between the carboxylic groups of the modified polyolefin and the -OH end groups of the saponified olefin-vinyl ester copolymer. These reactions contribute to the compatibility of the polycarbonate with the polyolefin. Accordingly, by blending the polycarbonate, the polyolefin, the modified polyolefin and the saponified olefin-vinyl ester copolymer, good compatibility between the polycarbonate and the polyolefin can be achieved, thereby providing the thermoplastic resin composition with a good balance of mechanical properties, moldability, solvent resistance. The thermoplastic resin composition according to the fourth embodiment of the present invention is characterized by containing the modified polyolefin and the epoxy group-containing styrene copolymer as third and fourth components. The modified polyolefin in this embodiment may be the same as in the first embodiment. The epoxy group-containing styrene copolymer is a copolymer composed of an unsaturated epoxy compound and a styrene monomer. The unsaturated epoxy compound is a compound having an epoxy group and a polymerizable unsaturated group in its molecules including unsaturated glycidyl esters, unsaturated glycidyl ethers, epoxy alkanes, p-glycidyl styrenes, Specific examples thereof are glycidyl acrylate, glycidyl methacrylate, glycidyl itaconate allyl glycidyl ether, 2-methyl allyl glycidyl ether, styrene-p-glycidyl ether, 3,4-epoxy butene, 3,4-epoxy-3-methyl-1-butene, 3,4-epoxy-1-pentene, 3,4-epoxy-3-methylpentene, 5,6-epoxy-1-hexene, vinyl cyclohexene monoxide, p-glycidyl styrene. The styrene monomer may be styrene, α-methylstyrene, vinyl toluene, 2,4-dimethylstyrene, chlorostyrene, p-methylstyrene. Other monomers copolymerizable with the unsaturated epoxy compound and the styrene monomer include acrylonitrile monomers such as acrylonitrile, methacrylonitrile. acrylate monomers such as methyl acrylate, 2-ethylhexyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, butyl acrylate, methoxybutyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, phenyl methacrylate, lauryl methacrylate. The epoxy group-containing monomer in the epoxy group-containing styrene copolymer is 1-50 mol %. When it is less than 1 mol %, it does not have sufficient reactivity with the modified polyolefin, and when it exceeds 50 mol %, it loses compatibility with the polycarbonate. The preferred content of the epoxy group-containing monomer is 3-20 mol %. The amount of the styrene monomer is 50-94 mol % in the epoxy group-containing styrene copolymer. When it is less than 50 mol%, it does not have good compatibility with the polycarbonate. When it exceeds 94 mol %, it does not have sufficient reactivity with the modified polyolefin. The epoxy group-containing styrene copolymer may further contain acrylonitrile. When acrylonitrile, is contained, its content is 5-20 mol %. Acrylonitrile, serves to increase the affinity of the epoxy group-containing styrene copolymer for the polycarbonate. The epoxy group-containing styrene copolymer has a number-average molecular weight of 2,000 or more. When it is less than 2,000, the copolymer's mechanical strength is low. The preferred number-average molecular weight is 3,000-200,000. The content of the modified polyolefin is 2-30 parts by weight per 100 parts by weight of the aromatic polycarbonate + the polyolefin. When it is less than 2 parts by weight, sufficient effect of improving the compatibility between the aromatic polycarbonate and the polyolefin cannot be provided by the addition of the modified polyolefin. On the other hand, when it exceeds 30 parts by weight, the resulting composition has low mechanical properties such as rigidity and impact resistance. The preferred amount of the modified polyolefin is 5-20 parts by weight in this embodiment. The content of the epoxy group-containing styrene copolymer is 2-30 parts by weight per 100 parts by weight of the aromatic polycarbonate + the polyolefin. When it is less than 2 parts by weight, sufficient effect of improving the compatibility between the aromatic polycarbonate and the polyolefin cannot be provided by the addition of the epoxy group-containing styrene copolymer. On the other hand, when it exceeds 30 parts by weight, the resulting composition has low mechanical properties such as rigidity and impact resistance. The preferred amount of the epoxy group-containing styrene copolymer is 5-20 parts by weight in this embodiment. The thermoplastic resin composition of this embodiment may further contain up to 100 parts by weight of rubber components such a low-crystallinity ethylene-α-olefin copolymer, an acrylic elastomer, a butyl rubber. per 100 parts by weight of the crystalline polyolefin + the polycarbonate. The epoxy group-containing styrene copolymer has a good affinity for the polycarbonate, and a reaction takes place between the carboxylic groups of the modified polyolefin and the epoxy groups of the epoxy group-containing styrene copolymer to generate a graft copolymer. These reactions contribute to the compatibility of the polycarbonate with the polyolefin. Accordingly, by blending the polycarbonate, the polyolefin, the modified polyolefin and the epoxy group-containing styrene copolymer, good compatibility between the polycarbonate and the polyolefin can be achieved, thereby providing the thermoplastic resin composition with a good balance of mechanical properties, moldability, solvent resistance, The present invention will be explained in further detail referring to the following Examples. The measurement of the properties of the thermoplastic resin compositions were conducted in each Example and Comparative Example as follows: (1) Flexural modulus Measured according to ASTM D790. (2) Izod impact strength Measured according to ASTM D256 at 23°C and -30°C, respectively. (3) Dynamic melt viscosity Measured by a dynamic spectrometer of Rheometrix at 250°C and 100 rad/sec. (4) Surface peel resistance The surface of each sample was cut by a razor in a checkered pattern to have 100 checkers of 1 mm x 1 mm. An adhesive cellophane tape (manufactured by Nichiban Co., Ltd.) was adhered onto the sample surface and then peeled off. The number of remaining checkers was counted. (5) Weight change by methanol immersion Each sample was immersed in methanol at 25°C for 30 days and the change in its weight was measured. (6) Tensile elongation at break Measured according to ASTM D 638. (7) Heat deflection temperature Measured according to ASTM D648 and shown by a temperature at which a test piece (cantilever) was distorted by a predetermined amount (0.254 mm) under a constant load (4.6 Kgf/cm 2 ) when the temperature was elevated at a constant rate of 2°C/min. (8) Thermal deformation temperature Measured according to JIS K7207, and shown by a temperature at which a test piece (cantilever) was deformed by a predetermined amount (0.25 mm) under a constant load (4.6 Kgf/cm 2 ) when the temperature was elevated at a constant rate of 2°C/min. Examples 1-5 Crystalline polypropylene (J209 manufactured by Tonen Sekiyu Kagaku K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225™ ○ manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), maleic anhydride-modified polypropylene (graft content = 0.6 weight %, unreacted maleic anhydride content = 0) and polybutylene terephthalate (C 7000 manufactured by Teijin, Ltd., intrinsic viscosity [η] = 1.2) were dry-blended in the proportions shown in Table 1. Each of the resulting mixtures was kneaded at 280°C in a double-screw extruder to provide composition pellets. The resulting thermoplastic resin compositions were formed into test pieces by injection molding at 280°C and measured with respect to thermal deformation temperature, dynamic melt viscosity, surface peel resistance and solvent resistance (weight change by methanol immersion). The results are shown in Table 1. Example 6 Block polypropylene (BJ 309 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225™ ○ manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), maleic anhydride-modified polypropylene (graft content = 0.6 weight %, unreacted maleic anhydride content = 0) and polybutylene terephthalate (C7000 manufactured by Teijin, Ltd., intrinsic viscosity [η] = 1.2) were mixed in the proportions shown in Table 1 and formed into thermoplastic resin composition pellets in the same manner as in Example 1. The resulting thermoplastic resin composition was formed into test pieces by injection molding at 280°C, and their properties were measured in the same manner as in Example 1. The results are shown in Table 1. Example 7 Polypropylene (J209 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225™ ○ manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), acrylic acid-modified polypropylene (graft content = 0.8 weight %, unreacted acrylic acid content = 0) and polybutylene terephthalate (C 7000 manufactured by Teijin, Ltd., intrinsic viscosity [η] = 1.2) were mixed in the proportions shown in Table 9 and formed into thermoplastic resin composition pellets in the same manner as in Example 1. The resulting thermoplastic resin composition was formed into test pieces by injection molding at 280°C, and their properties were measured in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 1 In the case of 100 weight % polypropylene, the resin's properties were similarly measured. The results are shown in Table 2. Comparative Example 2 In the case of 100 weight % aromatic polycarbonate, the resin's properties were similarly measured. The results are shown in Table 2. Comparative Examples 3, 4 Thermoplastic resin compositions were prepared in the same manner as in Example 1 except for using a two-component system consisting of the crystalline polypropylene and the aromatic polycarbonate, and their properties were measured. The results are shown in Table 2. Comparative Examples 5, 6 Only the polypropylene, the aromatic polycarbonate resin and the modified polyolefin were mixed in the proportions shown in Table 2 at room temperature in a Henschel mixer. Each resulting mixture was then kneaded at 280°C in a double-screw extruder to provide composition pellets. The properties of the resulting thermoplastic resin compositions were measured in the same manner as in Example 1. The results are shown in Table 2. Comparative Examples 7, 8 Only the polypropylene, the aromatic polycarbonate resin and the polybutylene terephthalate were blended in the proportions shown in Table 2 at 280°C, and the properties of the resulting thermoplastic resin compositions were measured in the same manner as in Example 1. The results are shown in Table 2. It is clear from Tables 1 and 2 that the thermoplastic resin compositions of the present invention have a much better balance of thermal deformation resistance (shown by heat deflection temperature), moldability (shown by dynamic melt viscosity) surface peel resistance and solvent resistance than that outside the scope of the present invention (Comparative Examples). Examples 8-12 Crystalline polypropylene (J209 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225 manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), maleic anhydride-modified polypropylene (graft content = 0.6 weight %, unreacted maleic anhydride content = 0) and a reactive polystyrene (RPS™ ○ manufactured by Dow Chemical, oxazoline ring-containing monomer content = about 1 weight %) as a styrene/oxazoline ring-containing monomer copolymer were dry-blended in the proportions shown in Table 3 and kneaded at 230°C in a double-screw extruder to provide composition pellets. The resulting thermoplastic resin composition pellets were formed into test pieces by injection molding at 230°C and measured with respect to thermal deformation temperature, dynamic melt viscosity, surface peel resistance and solvent resistance (weight change by methanol immersion). The results are shown in Table 3. Example 13 Block polypropylene (BJ 309 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225 manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), maleic anhydride-modified polypropylene (graft content = 0.6 weight %, unreacted maleic anhydride content = 0) and a reactive polystyrene (RPS™ ○ manufactured by Dow Chemical, oxazoline ring-containing monomer content = about 1 weight %) were dry-blended in the proportions shown in Table 3 to prepare thermoplastic resin composition pellets in the same manner as in Example 8. The resulting thermoplastic resin composition pellets were formed into test pieces by injection molding at 230°C, and their properties were measured as in Example 8. The results are shown in Table 3. Example 14 Polypropylene (J209 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225 manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), an acrylic acid-modified polypropylene (graft content = 0.8 weight %, unreacted acrylic acid content = 0) and a reactive polystyrene (RPS™ ○ manufactured by Dow Chemical, oxazoline ring-containing monomer content = about 1 weight %) were dry-blended in the proportions shown in Table 3 to prepare thermoplastic resin composition pellets in the same manner as in Example 8. The resulting thermoplastic resin composition pellets were formed into test pieces by injection molding at 230°C, and their properties were measured as in Example 8. The results are shown in Table 3. Comparative Examples 9, 10 Only the polypropylene, the aromatic polycarbonate resin and the modified polyolefin were mixed in the proportions shown in Table 4 at room temperature in a Henschel mixer. Each of the resulting mixtures was then kneaded at 230°C in a double-screw extruder to provide composition pellets. The properties of the resulting thermoplastic resin compositions were measured in the same manner as in Example 8. The results are shown in Table 4. Comparative Examples 11, 12 Only the polypropylene, the aromatic polycarbonate resin and the oxazoline ring-containing styrene copolymer were blended in the proportions shown in Table 4 at 230°C to prepare thermoplastic resin composition pellets, and their properties were measured in the same manner as in Example 8. The results are shown in Table 4. It is clear from Tables 13 and 14 that the thermoplastic resin compositions of the present invention have a much better balance of thermal deformation resistance (shown by heat deflection temperature), moldability (shown by dynamic melt viscosity), surface peel resistance and solvent resistance than that outside the scope of the present invention (Comparative Examples). Examples 15-19 Crystalline polypropylene (J209 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225™ ○ manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), maleic anhydride-modified polypropylene (graft content = 0.6 weight %, unreacted maleic anhydride content = 0) and a saponified ethylene-vinyl acetate copolymer (95%-saponified ethylene-vinyl acetate copolymer (MB-600 manufactured by Nippon Unicar Co., Ltd., vinyl acetate content = 35 weight %, MI = 35 g/10 min, density = 0.96 g/ml)) were dry-blended in the proportions shown in Table 5, and kneaded at 230°C in a double-screw extruder to provide composition pellets. The resulting thermoplastic resin composition pellets were formed into test pieces by injection molding at 230°C and measured with respect to thermal deformation temperature, dynamic melt viscosity, surface peel resistance and solvent resistance (weight change by methanol immersion). The results are shown in Table 5. Example 20 Block polypropylene (BJ 309 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225™ ○ manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), maleic anhydride-modified polypropylene (graft content = 0.6 weight %, unreacted maleic anhydride content = 0) and a saponified ethylene-vinyl acetate copolymer (95 %-saponified ethylene-vinyl acetate copolymer (MB-600 manufactured by Nippon Unicar Co, Ltd., vinyl acetate content = 35 weight %, MI = 35 g/10 min, density = 0.96 g/ml)) were dry-blended in the proportions shown in Table 5 to prepare thermoplastic resin composition pellets. The resulting thermoplastic resin composition pellets were formed into test pieces by injection molding at 230°C, and their properties were measured as in Example 15. The results are shown in Table 5. Example 21 Polypropylene (J209 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225™ ○ manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), acrylic acid-modified polypropylene (graft content = 0.8 weight %, unreacted acrylic acid content = 0) and a saponified ethylene-vinyl acetate copolymer (95%-saponified ethylene-vinyl acetate copolymer (MB-600 manufactured by Nippon Unicar Co., Ltd., vinyl acetate content = 35 weight %, MI = 35 g/10 min, density = 0.96 g/ml)) were dry-blended in the proportions shown in Table 5 to prepare thermoplastic resin composition pellets. The resulting thermoplastic resin composition pellets were formed into test pieces by injection molding at 230°C, and their properties were measured as in Example 15. The results are shown in Table 5. Comparative Example 13 In the case of 100 weight % polypropylene, the resin's properties were similarly measured. The results are shown in Table 6. Comparative Example 14 In the case of 100 weight % aromatic polycarbonate, the resin's properties were similarly measured. The results are shown in Table 6. Comparative Examples 15, 16 Thermoplastic resin compositions were prepared in the same manner as in Example 15 except for using a two-component system consisting of the crystalline polypropylene and the aromatic polycarbonate, and their properties were measured. The results are shown in Table 6. Comparative Examples 17, 18 Only the polypropylene, the aromatic polycarbonate resin and the modified polyolefin were mixed in the proportions shown in Table 6 at room temperature in a Henschel mixer. Each of the resulting mixtures was then kneaded at 230°C in a double-screw extruder to provide composition pellets. The properties of the resulting thermoplastic resin compositions were measured in the same manner as in Example 15. The results are shown in Table 6. Comparative Examples 19, 20 Only the polypropylene, the aromatic polycarbonate resin and the saponified ethylene-vinyl acetate copolymer were blended and kneaded in the proportions shown in Table 6 at 230°C to prepare thermoplastic resin composition pellets, and their properties were measured in the same manner as in Example 15. The results are shown in Table 6. It is clear from Tables 15 and 16 that the thermoplastic resin compositions of the present invention have a much better balance of thermal deformation resistance (shown by heat deflection temperature), moldability (shown by dynamic melt viscosity), surface peel resistance and solvent resistance than that outside the scope of the present invention (Comparative Examples). Examples 22-26 Crystalline polypropylene (J209 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225™ ○ manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), maleic anhydride-modified polypropylene (graft content = 0.6 weight %, unreacted maleic anhydride content = 0) and a copolymer consisting of 20 weight % of glycidyl methacrylate, 60 weight % of styrene and 20 weight % of acrylonitrile (Blemmer CP20 SA™ ○ manufactured by Nippon Oil And Fats Co., Ltd.) were dry-blended in the proportions shown in Table 7 and kneaded at 230°C in a double-screw extruder to provide composition pellets. The resulting thermoplastic resin composition pellets were formed into test pieces by injection molding at 230°C and measured with respect to thermal deformation temperature, dynamic melt viscosity, surface peel resistance and solvent resistance (weight change by methanol immersion). The results are shown in Table 7. Example 27 Block polypropylene (BJ 309 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225™ ○ manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), maleic anhydride-modified polypropylene (graft content = 0.6 weight %, unreacted maleic anhydride content = 0) and a copolymer consisting of 20 weight % of glycidyl methacrylate, 60 weight % of styrene and 20 weight % of acrylonitrile (Blemmer CP20 SA™ ○ manufactured by Nippon Oil And Fats Co., Ltd.) were dry-blended in the proportions shown in Table 7 to prepare thermoplastic resin composition pellets in the same manner as in Example 22. The resulting thermoplastic resin composition pellets were formed into test pieces by injection molding at 230°C, and their properties were measured as in Example 22. The results are shown in Table 7. Example 28 Polypropylene (J209 manufactured by Tonen Sekiyu Kagaku Kogyo K.K., MFR = 9.0 g/10 min), an aromatic polycarbonate resin (Panlite L 1225™ ○ manufactured by Teijin Chemicals, Ltd., weight-average molecular weight = 22,500), acrylic acid-modified polypropylene (graft content = 0.8 weight %, unreacted acrylic acid content = 0) and a copolymer consisting of 20 weight % of glycidyl methacrylate, 60 weight % of styrene and 20 weight % of acrylonitrile (Blemmer CP20 SA™ ○ manufactured by Nippon Oil And Fats Co., Ltd.) were dry-blended in the proportions shown in Table 7 to prepare thermoplastic resin composition pellets in the same manner as in Example 22. The resulting thermoplastic resin composition pellets were formed into test pieces by injection molding at 230°C, and their properties were measured as in Example 22. The results are shown in Table 7. Comparative Examples 21, 22 Only the polypropylene, the aromatic polycarbonate resin and the modified polyolefin were mixed in the proportions shown in Table 8 at room temperature in a Henschel mixer. Each of the resulting mixtures was then kneaded at 230°C in a double-screw extruder to provide composition pellets. The properties of the resulting thermoplastic resin compositions were measured in the same manner as in Example 22. The results are shown in Table 8. Comparative Examples 23, 24 Only the polypropylene, the aromatic polycarbonate resin and the epoxy group-containing styrene copolymer were blended and kneaded in the proportions shown in Table 8 at 230°C to prepare thermoplastic resin composition pellets, and their properties were measured in the same manner as in Example 22. The results are shown in Table 8 . It is clear from Tables 7 and 8 that the thermoplastic resin compositions of the present invention have a much better balance of thermal deformation resistance (shown by heat deflection temperature), moldability (shown by dynamic melt viscosity), surface peel resistance and solvent resistance than that outside the scope of the present invention (Comparative Examples). As described above in detail, since the thermoplastic resin composition of the the present invention contains the above-described additional components, the compatibility between the polycarbonate and the polyolefin is improved. Accordingly, it has well-balanced properties such as mechanical strength, impact strength, thermal deformation resistance, surface peel resistance, moldability, chemical resistance, etc. The thermoplastic resin composition of the present invention having such properties are highly suitable as engineering plastic materials for parts of automobiles, and electric appliances.

Claims: A thermoplastic resin composition comprising: (a) 95-5 weight % of crystalline polyolefin having a crystallinity of 20% or more measured by an X-ray diffraction method, (b) 5-95 weight % of polycarbonate, (c) 2-100 parts by weight, per 100 parts by weight of said (a) and said (b), of a polyolefin modified with unsaturated carboxylic acid or its anhydride, the content of said unsaturated carboxylic acid or its anhydride in the modified polyolefin being 0.1-10 weight %, and (d) 2-100 parts by weight, per 100 parts by weight of said (a) and said (b), of polybutylene terephthalate. A thermoplastic resin composition comprising: (a) 95-5 weight % of crystalline polyolefin having a crystallinity of 20% or more measured by an X-ray diffraction method, (b) 5-95 weight % of polycarbonate (c) 2-30 parts by weight, per 100 parts by weight of said (a) and said (b), of a polyolefin modified with unsaturated carboxylic acid or its anhydride, the content of said unsaturated carboxylic acid or its anhydride in the modified polyolefin being 0.1-10 weight %, and (d) 2-30 parts by weight, per 100 parts by weight of said (a) and said (b), of an oxazoline ring-containing copolymer comprising an oxazoline ring-containing monomer and a styrene monomer, the content of said oxazoline ring-containing monomer in said oxazoline ring-containing copolymer being 0.1-10 weight %. A thermoplastic resin composition consisting essentially of: (a) 95-5 weight % of a crystalline polyolefin having a crystallinity of 20% or more measured by an X-ray diffraction method, (b) 5-95 weight % of polycarbonate, (c) 2-30 parts by weight, per 100 parts by weight of said (a) and said (b), of a polyolefin, modified with unsaturated carboxylic acid or its anhydride, the content of said unsaturated carboxylic acid or its anhydride in the modified polyolefin being 0.1-10 weight % and (d) 2-100 parts by weight, per 100 parts by weight of said (a) and said (b), of a saponified olefin-vinyl ester copolymer having a saponification degree of 50% or more, the content of the vinyl ester in said saponified olefin-vinyl ester copolymer being 10-70 weight %. A thermoplastic resin composition comprising: (a) 95-5 weight % of crystalline polyolefin having a crystallinity of 20% or more measured by an X-ray diffraction method, (b) 5-95 weight % of polycarbonate, (c) 2-30 parts by weight, per 100 parts by weight of said (a) and said (b), of a polyolefin modified with unsaturated carboxylic acid or its anhydride, the content of said unsaturated carboxylic acid or its anhydride in the modified polyolefin being 0.1-10 weight%, and (d) 2-30 parts by weight, per 100 parts by weight of said (a) and said (b), of an epoxy group-containing styrene copolymer comprising a copolymer composed of an unsaturated epoxy compound and a styrene monomer, the content of said unsaturated epoxy compound being 1-50 mol%.

Inventors: FUJITA YUUJI, KAWAMURA TETSUYA, KITANO KITSUSHO, MIKAMI TAKASHI, NARUKAWA KIYOTADA, NISHIO TAKEYOSHI, NOMURA TAKAO, SATO SHIGERU, SEZUME TADASHI, YOKOI TOSHIO, FUJITA, YUUJI, KAWAMURA, TETSUYA, KITANO, KITSUSHO, MIKAMI, TAKASHI, NARUKAWA, KIYOTADA, NISHIO, TAKEYOSHI, NOMURA, TAKAO, SATO, SHIGERU, SEZUME, TADASHI, YOKOI, TOSHIO
Applicants: TONEN SEKIYUKAGAKU KK, TOYOTA MOTOR CO LTD, TONEN SEKIYUKAGAKU K.K., TOYOTA JIDOSHA KABUSHIKI KAISHA
Application year: 1988
Main classification: C08L23
IPC codes: C08L69, C08L23