Thermoplastic resin composition

Abstract

To provide a thermoplastic resin composition excellent in balance of impact resistance, heat resistance, weather resistance, dimensional stability and thermal stability.SOLUTION: There are provided: a thermoplastic resin composition which contains a polycarbonate resin, a graft copolymer, a copolymer containing an aromatic vinyl monomer and a vinyl cyanide monomer, and talc in specific amounts; and a thermoplastic resin composition which contains a polycarbonate resin, a graft copolymer, a copolymer containing an aromatic vinyl monomer and a vinyl cyanide monomer, talc, and a phosphoric acid compound in specific amounts.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermoplastic resin composition having an excellent balance of impact resistance, heat resistance, weather resistance, dimensional stability and thermal stability. [Background technology]

[0002] Compositions consisting of polycarbonate resin and ABS resin (hereinafter referred to as PC / ABS resin) have excellent impact resistance, heat resistance, and moldability, and are therefore used in a variety of applications, including vehicle parts, home appliances, and office equipment parts. In particular, vehicle parts tend to become larger and have more complex designs. Furthermore, to reduce vehicle weight, molded parts tend to be designed with thinner walls, which creates a demand for materials with excellent moldability, impact resistance, and heat resistance. PC / ABS resins are often used as one of the options.

[0003] When glass fibers or carbon fibers are added to PC / ABS resins to improve rigidity and dimensional stability, the impact resistance decreases and the appearance of the molded product deteriorates. In contrast, when talc is added, the appearance of the molded product improves, but the thermal stability decreases and a defect in appearance known as silver occurs on the surface of the molded product during the injection molding process.

[0004] As methods for improving thermal stability when talc is blended, for example, Patent Document 1 discloses a resin composition containing a polycarbonate resin, a graft polymer, talc, and a phosphate ester compound, Patent Document 2 discloses a resin composition containing a resin having an aromatic polycarbonate resin as an essential component, talc containing a granular organic phosphate ester compound, and a rubbery polymer, and Patent Document 3 discloses a resin composition containing an aromatic polycarbonate resin, an emulsion-polymerized thermoplastic resin, and an acidic phosphate ester having a defined structural formula.

[0005] However, in recent years, molding temperatures have tended to rise due to the trend toward larger molded parts, more complex shape designs, and thinner walls due to weight reduction, and even greater thermal stability is required, which is still not satisfactory. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-138122

[0007] [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-229305

[0008] [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-158737 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a thermoplastic resin composition that has an excellent balance of impact resistance, heat resistance, weather resistance, dimensional stability, and thermal stability. [Means for solving the problem]

[0010] That is, the present invention comprises the following [1] to [5]. [1] A thermoplastic resin composition comprising a polycarbonate resin (A), a graft copolymer (B), a copolymer (C), and talc (D), and satisfying the following conditions (1) to (7): (1) The content of the polycarbonate resin (A) is 40 to 80% by mass in a total of 100% by mass of (A), (B), (C) and (D). (2) The graft copolymer (B) is a graft copolymer obtained by graft polymerization of a rubber polymer (b-1) and a monomer component (b-2) containing at least one selected from the group consisting of an aromatic vinyl monomer, a vinyl cyanide monomer, and a (meth)acrylic acid ester monomer. (3) The content of the graft copolymer (B) is 5 to 45% by mass based on 100% by mass of the total of (A), (B), (C) and (D). (4) The copolymer (C) is a copolymer obtained by polymerizing a monomer component containing an aromatic vinyl monomer and a vinyl cyanide monomer. (5) The content of copolymer (C) is 0 to 39% by mass based on 100% by mass of the total of (A), (B), (C) and (D). (6) The content of talc (D) is 5 to 30% by mass based on 100% by mass of the total of (A), (B), (C), and (D). (7) The thermoplastic resin composition has a resin pH of 5.0 to 6.8. [2] The thermoplastic resin composition according to [1], characterized in that it contains 0.01 to 1.5 parts by mass of a phosphoric acid compound (E) relative to 100 parts by mass of the total of (A), (B), (C), and (D). [3] A thermoplastic resin composition comprising a polycarbonate resin (A), a graft copolymer (B), a copolymer (C), talc (D), and a phosphoric acid compound (E), and satisfying the following conditions (1) to (8): (1) The content of the polycarbonate resin (A) is 40 to 80% by mass in a total of 100% by mass of (A), (B), (C) and (D). (2) The graft copolymer (B) is a graft copolymer obtained by graft polymerization of a rubber polymer (b-1) and a monomer component (b-2) containing at least one selected from the group consisting of an aromatic vinyl monomer, a vinyl cyanide monomer, and a (meth)acrylic acid ester monomer. (3) The content of the graft copolymer (B) is 5 to 45% by mass based on 100% by mass of the total of (A), (B), (C) and (D). (4) The copolymer (C) is a copolymer obtained by polymerizing a monomer component containing an aromatic vinyl monomer and a vinyl cyanide monomer. (5) The content of copolymer (C) is 0 to 39% by mass based on 100% by mass of the total of (A), (B), (C) and (D). (6) The content of talc (D) is 5 to 30% by mass based on 100% by mass of the total of (A), (B), (C), and (D). (7) The content of the phosphoric acid compound (E) is 0.01 to 1.5 parts by mass per 100 parts by mass of the total of (A), (B), (C), and (D). (8) The resin pH of the thermoplastic resin composition is 6.8 or less. [4] A thermoplastic resin composition comprising a polycarbonate resin (A), a graft copolymer (B), a copolymer (C), talc (D), and a phosphoric acid compound (E), and satisfying the following conditions (1) to (8): (1) The content of the polycarbonate resin (A) is 40 to 80% by mass in a total of 100% by mass of (A), (B), (C) and (D). (2) The graft copolymer (B) is a graft copolymer obtained by graft polymerization of a rubber polymer (b-1) and a monomer component (b-2) containing at least one selected from the group consisting of an aromatic vinyl monomer, a vinyl cyanide monomer, and a (meth)acrylic acid ester monomer. (3) The resin pH of the graft copolymer (B) is 3 to 6.6. (4) The content of the graft copolymer (B) is 5 to 45% by mass based on 100% by mass of the total of (A), (B), (C) and (D). (5) The copolymer (C) is a copolymer obtained by polymerizing a monomer component containing an aromatic vinyl monomer and a vinyl cyanide monomer. (6) The content of copolymer (C) is 0 to 39% by mass based on 100% by mass of the total of (A), (B), (C) and (D). (7) The content of talc (D) is 5 to 30% by mass based on 100% by mass of the total of (A), (B), (C), and (D). (8) The content of the phosphoric acid compound (E) is 0.01 to 1.5 parts by mass per 100 parts by mass of the total of (A), (B), (C), and (D). [5] The thermoplastic resin composition according to any one of [1] to [4], characterized in that it contains 3 to 13 parts by mass of a phosphate ester per 100 parts by mass of the total of (A), (B), (C), and (D). [Effects of the Invention]

[0011] The present invention can provide a thermoplastic resin composition that is excellent in balance between impact resistance, heat resistance, weather resistance, dimensional stability, and thermal stability. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below.

[0013] A thermoplastic resin composition according to a first embodiment of the present invention is a thermoplastic resin composition containing a polycarbonate resin (A), a graft copolymer (B), a copolymer (C), and talc (D), and the resin pH of the thermoplastic resin composition is specified within a specific range.

[0014] A thermoplastic resin composition according to a second embodiment of the present invention is a thermoplastic resin composition containing a polycarbonate resin (A), a graft copolymer (B), a copolymer (C), talc (D), and a phosphoric acid compound (E), and the resin pH of the thermoplastic resin composition is specified within a specific range.

[0015] A thermoplastic resin composition according to a third embodiment of the present invention is a thermoplastic resin composition containing a polycarbonate resin (A), a graft copolymer (B), a copolymer (C), talc (D), and a phosphoric acid compound (E), in which the resin pH of the graft copolymer (B) is specified within a specific range.

[0016] The polycarbonate resin (A) used in the thermoplastic resin compositions according to the first, second and third aspects of the present invention is a polymer obtained by a phosgene method in which various dihydroxydiaryl compounds are reacted with phosgene, or a transesterification method in which a dihydroxydiaryl compound is reacted with a carbonate ester such as diphenyl carbonate, and a representative example thereof is a polycarbonate resin produced from 2,2-bis(4-hydroxyphenyl)propane, or "bisphenol A."

[0017] Examples of the dihydroxydiaryl compound include, in addition to bisphenol A, bis(hydroxyaryl)alkanes such as bis(4-hydroxydiphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)diphenylmethane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, and 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane; dihydroxydiphenyl ethers such as 4,4'-dihydroxydiphenyl ether and 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether; dihydroxydiaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide; dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide; and dihydroxydiaryl sulfones such as 4,4'-dihydroxydiphenyl sulfone and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone.

[0018] These may be used alone or in combination of two or more kinds, and other compounds such as piperazine, dipiperidylhydroquinone, resorcinol, and 4,4'-dihydroxydiphenyls may also be mixed.

[0019] Furthermore, the dihydroxydiaryl compound may be mixed with a trivalent or higher phenol compound such as those shown below. Examples of trivalent or higher phenols include phloroglucinol, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptene, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane, 1,3,5-tri-(4-hydroxyphenyl)benzene, 1,1,1-tri-(4-hydroxyphenyl)ethane, and 2,2-bis-[4,4-bis(4-hydroxyphenyl)cyclohexyl]propane. When producing these polycarbonate resins, the weight-average molecular weight of the polycarbonate resin is typically 10,000 to 80,000, preferably 15,000 to 60,000. A molecular weight modifier, catalyst, etc. may be used as needed. The weight-average molecular weight can be measured by gel permeation chromatography (GPC) using polystyrene as a standard.

[0020] The graft copolymer (B) used in the thermoplastic resin compositions according to the first, second and third aspects of the present invention is obtained by graft polymerizing a rubbery polymer (b-1) with a monomer component (b-2) containing at least one monomer selected from an aromatic vinyl monomer, a vinyl cyanide monomer and a (meth)acrylic acid ester monomer.

[0021] The rubbery polymer (b-1) constituting the graft copolymer (B) is not particularly limited, and can be one or more of conjugated diene rubbers such as polybutadiene rubber, styrene-butadiene rubber (SBR), and acrylonitrile-butadiene rubber (NBR), which are obtained by known polymerization methods; ethylene-propylene rubbers such as ethylene-propylene rubber and ethylene-propylene-non-conjugated diene (ethylidene norbornene, dicyclopentadiene, etc.) rubber; acrylic rubbers such as polybutyl acrylate rubber; and silicone rubbers. The acrylic rubbers also include rubbers having a core-shell structure. Examples of rubbers having a core-shell structure (referred to as core / shell) include conjugated diene rubber / acrylic rubber, silicone rubber / acrylic rubber, and hard polymer (glass transition temperature of 20°C or higher) / acrylic rubber. Examples of rigid polymers (having a glass transition temperature of 20°C or higher) include polymers obtained by polymerizing one or more monomers selected from aromatic vinyl monomers, vinyl cyanide monomers, and (meth)acrylic acid ester monomers. Among these, polybutadiene rubber, styrene-butadiene rubber, ethylene-propylene-diene rubber, conjugated diene rubber / acrylic rubber, silicone rubber / acrylic rubber, and rigid polymer (having a glass transition temperature of 20°C or higher) / acrylic rubber are preferred. The glass transition temperature of a rigid polymer can be calculated using the FOX formula.

[0022] The weight-average particle size of the rubbery polymer (b-1) is not particularly limited, but from the viewpoint of impact resistance, it is preferably 0.1 to 2.0 μm, more preferably 0.15 to 1.0 μm. It can also be adjusted by aggregating and enlarging a rubbery polymer having a weight-average particle size of 0.05 to 0.3 μm.

[0023] The graft copolymer (B) is obtained by graft polymerizing the above-mentioned rubbery polymer (b-1) with a monomer component (b-2) containing at least one selected from an aromatic vinyl monomer, a vinyl cyanide monomer, and a (meth)acrylic acid ester monomer.

[0024] Examples of the aromatic vinyl monomer of the monomer component (b-2) include styrene, α-methylstyrene, paramethylstyrene, bromostyrene, etc., and one or more of these can be used.

[0025] Examples of the vinyl cyanide monomer of the monomer component (b-2) include acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile, etc., and one or more of these can be used.

[0026] Examples of the (meth)acrylic acid ester monomer of the monomer component (b-2) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl acrylate, phenyl (meth)acrylate, 4-t-butylphenyl (meth)acrylate, (di)bromophenyl (meth)acrylate, and chlorophenyl (meth)acrylate, and one or more of these can be used.

[0027] The monomer component (b-2) may contain other monomers copolymerizable with the aromatic vinyl monomer, the vinyl cyanide monomer, and the (meth)acrylic acid ester monomer, such as maleimide monomers, amide monomers, unsaturated carboxylic acid monomers, and polyfunctional monomers, and one or more of these may be used.

[0028] Examples of the maleimide monomer include N-phenylmaleimide and N-cyclohexylmaleimide.

[0029] Examples of the amide monomer include acrylamide and methacrylamide.

[0030] Examples of the unsaturated carboxylic acid monomer include (meth)acrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid, and crotonic acid.

[0031] Examples of the polyfunctional monomer include divinylbenzene, allyl (meth)acrylate, ethylene glycol di(meth)acrylate, glycidyl (meth)acrylate, diallyl phthalate, dicyclopentadiene di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, triallyl cyanurate, and triallyl isocyanurate.

[0032] There are no particular restrictions on the composition ratio of the monomers to be graft polymerized onto the rubbery polymer (b-1), but the composition ratio is preferably 50 to 90 mass% of aromatic vinyl monomer, 10 to 50 mass% of vinyl cyanide monomer, and 0 to 40 mass% of other copolymerizable monomers; 0 to 50 mass% of aromatic vinyl monomer, 50 to 100 mass% of (meth)acrylic acid ester monomer, and 0 to 50 mass% of other copolymerizable vinyl monomers; or 20 to 70 mass% of aromatic vinyl monomer, 20 to 70 mass% of (meth)acrylic acid ester monomer, 10 to 60 mass% of vinyl cyanide monomer, and 0 to 50 mass% of other copolymerizable monomers (the total amount of monomers to be graft polymerized onto the rubbery polymer is taken as 100 mass%).

[0033] The content of the rubber polymer (b-1) in the graft copolymer (B) is preferably 20 to 80 mass %, more preferably 40 to 70 mass %, in view of the balance of physical properties such as impact resistance and fluidity.

[0034] The graft ratio of the graft copolymer (B) and the reduced viscosity of the acetone soluble matter are not particularly limited, but from the viewpoint of the balance of physical properties such as impact resistance and fluidity, the graft ratio is preferably 20 to 150%, more preferably 30 to 100%, and particularly preferably 36 to 75%. The reduced viscosity of the acetone soluble matter is preferably 0.2 to 1.5 dL / g, more preferably 0.3 to 1.0 dL / g.

[0035] The graft ratio and the reduced viscosity of the acetone soluble matter can be determined as follows.

[0036] Sorting method Approximately 2 g of graft copolymer (B) and 60 ml of acetone were placed in an Erlenmeyer flask and left to soak for 24 hours. The mixture was then centrifuged at 15,000 rpm for 30 minutes to separate the soluble and insoluble fractions. The insoluble fraction was obtained by drying overnight at room temperature using a vacuum dryer. The soluble fraction was obtained by precipitating the acetone-soluble fraction in methanol and then drying overnight at room temperature using a vacuum dryer. Grafting rate Graft rate (%) = (X-Y) / Y x 100 X: Amount of acetone insoluble matter after vacuum drying (g) Y: Amount of rubber polymer in the graft copolymer (g) Reduced viscosity of acetone soluble matter (dl / g) The acetone soluble portion is dissolved in N,N-dimethylformamide to give a solution with a concentration of 0.4 g / 100 ml, and the reduced viscosity is determined from the flow time measured at 30°C using a Cannon-Fenske viscometer.

[0037] The graft copolymer (B) obtained as described above usually mainly contains a grafted polymer (B1 component) in which a monomer component containing the monomer component (b-2) is grafted onto the rubber polymer (b-1), and also contains a copolymer (referred to as B2 component) in which a monomer component containing the monomer component (b-2) that is not grafted onto the rubber polymer (b-1) is copolymerized. Therefore, in the present invention, when the B2 component contained in the graft copolymer (B) satisfies the monomer components constituting the copolymer (C), it means that the copolymer (C) is contained.

[0038] The polymerization method for the graft copolymer (B) is not particularly limited, and it can be produced by, for example, emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or a combination of these, among which emulsion polymerization is preferred.

[0039] When the graft copolymer (B) is produced by emulsion polymerization, the final product is usually latex. The obtained latex can be converted into powder by coagulating, washing, dehydrating, and drying. As the coagulant used in the coagulation step, one or more of sulfuric acid, magnesium sulfate, calcium chloride, aluminum sulfate, etc. can be dissolved in water and used. Alternatively, a recovery and drying method using a spray dryer or the like can be used without using a coagulant.

[0040] The resin pH of the graft copolymer (B) is In the first and second embodiments of the present invention, there are no particular limitations, but it is preferably 3 to 6.6, more preferably 4 to 6.3, and even more preferably 4.5 to 5.9. In the third embodiment of the present invention, the pH must be 3 to 6.6, preferably 4 to 6.3, and more preferably 4.5 to 5.9. Adjusting the pH to within the above range tends to result in a product with excellent thermal stability. The resin pH of the graft copolymer (B) is measured in the form of a solid such as a powder or granules, and is measured by the method described in the Examples. When the graft copolymer (B) and a part or all of the copolymer (C) are mixed in the form of a latex to obtain a solid, the pH of the solid obtained by mixing is taken as the resin pH of the graft copolymer (B).

[0041] When the graft copolymer (B) is obtained by emulsion polymerization, the resin pH of the resulting powder can be adjusted by adjusting the pH of the slurry (aqueous dispersion of coagulated particles) obtained in the coagulation step. For example, this can be achieved by adding an acidic aqueous solution such as sulfuric acid or hydrochloric acid in the coagulation step to adjust the pH of the slurry to a lower value.

[0042] The copolymer (C) used in the thermoplastic resin compositions according to the first, second and third aspects of the present invention is obtained by polymerizing a monomer component containing an aromatic vinyl monomer and a vinyl cyanide monomer.

[0043] Examples of the aromatic vinyl monomer constituting the copolymer (C) include styrene, α-methylstyrene, paramethylstyrene, bromostyrene, etc., and one or more of these can be used.

[0044] Examples of vinyl cyanide monomers constituting the copolymer (C) include acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile, etc., and one or more of these can be used.

[0045] Furthermore, the copolymer (C) may contain other monomers copolymerizable with the aromatic vinyl monomer and the vinyl cyanide monomer, such as (meth)acrylic acid ester monomers, maleimide monomers, amide monomers, unsaturated carboxylic acid monomers, and polyfunctional monomers, and one or more of these monomers may be used. As these monomers, the same monomers as those described above as the monomer component (b-2) may be used.

[0046] There are no particular restrictions on the composition ratio of the monomers constituting the copolymer (C), but examples include a composition ratio of 50 to 90 mass% aromatic vinyl monomer, 10 to 50 mass% vinyl cyanide monomer, and 0 to 40 mass% other copolymerizable monomers, and a composition ratio of 20 to 70 mass% aromatic vinyl monomer, 10 to 60 mass% vinyl cyanide monomer, 20 to 70 mass% (meth)acrylic acid ester monomer, and 0 to 50 mass% other copolymerizable monomers.

[0047] The reduced viscosity of the copolymer (C) is not particularly limited, but from the viewpoint of the balance of physical properties such as impact resistance and fluidity, it is preferably 0.2 to 1.5 dl / g, more preferably 0.3 to 1.0 dl / g.

[0048] The reduced viscosity can be calculated by the following formula.

[0049] Copolymer (C) is dissolved in N,N-dimethylformamide to give a solution with a concentration of 0.4 g / 100 ml, and the reduced viscosity is determined from the flow time measured at 30° C. using a Cannon-Fenske viscometer.

[0050] The polymerization method for copolymer (C) constituting the thermoplastic resin composition is not particularly limited, and it can be produced by, for example, emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or a combination of these methods.

[0051] The talc (D) used in the thermoplastic resin compositions according to the first, second and third aspects of the present invention is hydrous magnesium silicate having a layer structure, and has an average particle size measured by a laser diffraction particle size measurement method of preferably 0.1 to 50 μm, more preferably 0.5 to 25 μm, and even more preferably 1 to 15 μm.

[0052] The phosphoric acid compound (E) used in the thermoplastic resin compositions according to the second and third aspects of the present invention is a compound in which a hydroxyl group and an oxo group are bonded to a phosphorus atom, and examples thereof include phosphoric acid, phosphorous acid, hypophosphorous acid, diphosphoric acid (polyphosphoric acid), methyl phosphate, and dimethyl phosphate.

[0053] The content of polycarbonate resin (A) constituting the thermoplastic resin composition according to the first, second and third aspects of the present invention must be 40 to 80 mass %, preferably 42 to 77 mass %, and more preferably 45 to 75 mass %, based on 100 mass % of the total of (A), (B), (C) and (D). By adjusting the content within the above range, the balance of fluidity, impact resistance and heat resistance can be improved.

[0054] The content of the graft copolymer (B) constituting the thermoplastic resin composition according to the first, second and third aspects of the present invention must be 5 to 45 mass %, preferably 7 to 35 mass %, and more preferably 10 to 28 mass %, based on 100 mass % of the total of (A), (B), (C) and (D). By adjusting the content within the above range, impact resistance can be improved.

[0055] The content of copolymer (C) constituting the thermoplastic resin composition according to the first, second and third aspects of the present invention must be 0 to 39% by mass, preferably 2 to 36% by mass, and more preferably 4 to 33% by mass, based on 100% by mass of the total of (A), (B), (C) and (D). By adjusting the content within the above range, flowability (moldability) can be improved. Furthermore, when component B2 contained in graft copolymer (B) satisfies the monomer components constituting copolymer (C), the content of copolymer (C) is the sum of component B2 calculated from the graft ratio of graft copolymer (B).

[0056] The content of talc (D) constituting the thermoplastic resin composition according to the first, second and third aspects of the present invention must be 5 to 30 mass %, preferably 8 to 27 mass %, and more preferably 12 to 22 mass %, relative to 100 mass % of the total of (A), (B), (C) and (D). By adjusting the content within the above range, dimensional stability and weather resistance can be improved.

[0057] The content of the phosphoric acid compound (E) constituting the thermoplastic resin composition according to the second and third aspects of the present invention must be 0.01 to 1.5 parts by mass, preferably 0.03 to 1.0 parts by mass, and more preferably 0.05 to 0.7 parts by mass, per 100 parts by mass of the total of (A), (B), (C), and (D). Adjusting the content within the above range can improve thermal stability. Furthermore, in the first aspect of the present invention, the phosphoric acid compound (E) can also be added optionally, and is preferably 0.01 to 1.5 parts by mass, more preferably 0.03 to 1.0 parts by mass, and even more preferably 0.05 to 0.7 parts by mass, per 100 parts by mass of the total of (A), (B), (C), and (D).

[0058] The thermoplastic resin compositions according to the first, second, and third aspects of the present invention may contain other thermoplastic resins as long as the effects of the present invention are not impaired. Examples of such other thermoplastic resins include acrylic resins such as polymethyl methacrylate, polyolefin resins such as polyethylene and polypropylene, polyester resins such as polybutylene terephthalate resin, polyethylene terephthalate resin, and polylactic acid resin, polyamide resins, and polyimide resins.

[0059] Furthermore, the thermoplastic resin compositions according to the first, second, and third aspects of the present invention may contain, within the scope of the present invention, hindered amine light stabilizers; antioxidants such as hindered phenols, sulfur-containing organic compounds, and phosphorus-containing organic compounds; heat stabilizers such as phenols and acrylates; ultraviolet absorbers such as benzoates, benzotriazoles, benzophenones, and salicylates; lubricants such as organonickels and higher fatty acid amides; flame retardants and flame retardant aids such as polybromophenyl ethers, tetrabromobisphenol-A, brominated epoxy oligomers, brominated halogen-containing compounds, phosphate esters, and antimony trioxide; odor masking agents; pigments such as carbon black and titanium oxide; dyes; and reinforcing agents and fillers such as calcium carbonate, aluminum hydroxide, glass fiber, glass flakes, glass beads, glass wool, carbon fiber, and metal fiber.

[0060] Among these, the phosphoric acid ester is preferably contained in an amount of 3 to 13 parts by mass, more preferably 4 to 10 parts by mass, based on 100 parts by mass of the total of (A), (B), (C), and (D) in terms of improving fluidity. Specific examples of the phosphoric acid ester include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri(2-ethylhexyl)phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(isopropylphenyl)phosphate, tris(phenylphenyl)phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl(2-ethylhexyl)phosphate, di(isopropylphenyl)phenyl phosphate, monoisodecyl phosphate, 2-acryloyloxyethyl acid phosphate, 2- Examples of condensed phosphate esters include methacryloyloxyethyl acid phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, triphenylphosphine oxide, tricresylphosphine oxide, diphenyl methanephosphonate, diethyl phenylphosphonate, resorcinol polyphenyl phosphate, resorcinol poly(di-2,6-xylyl)phosphate, bisphenol A polycresyl phosphate, hydroquinone poly(2,6-xylyl)phosphate, and condensates thereof. Examples of condensed phosphate esters include resorcinol bis(di-2,6-xylyl)phosphate, resorcinol bis(diphenyl phosphate), and bisphenol A bis(diphenyl phosphate). A commercially available product of resorcinol bis(di-2,6-xylyl)phosphate is PX-200 (manufactured by Daihachi Chemical Industry Co., Ltd.). A commercially available product of resorcinol bis(diphenyl phosphate) is CR-733S (manufactured by Daihachi Chemical Industry Co., Ltd.). A commercially available product of bisphenol A bis(diphenyl phosphate) is CR-741 (manufactured by Daihachi Chemical Industry Co., Ltd.).Among these, resorcinol bis(di-2,6-xylyl)phosphate and bisphenol A bis(diphenyl phosphate) are preferably used because of their excellent hydrolysis resistance, heat resistance, and low volatility.

[0061] The thermoplastic resin compositions according to the first, second and third aspects of the present invention can be obtained by melt-kneading the above-mentioned components using a known kneading machine such as a roll, a Banbury mixer, a single-screw extruder, a multi-screw extruder or a kneader.

[0062] The resin pH of the obtained thermoplastic resin composition was In the first embodiment of the present invention, it must be 5.0 to 6.8, and preferably 5.4 to 6.7. In the second embodiment of the present invention, it must be 6.8 or less. In the third embodiment of the present invention, there is no particular limitation, but it is preferably 5.0 to 6.8, and more preferably 5.4 to 6.7. By adjusting the pH value within the above range, a product with excellent thermal stability tends to be obtained. The resin pH of the thermoplastic resin composition is measured in the state of a granular solid such as a pellet, and is measured by the method described in the examples.

[0063] The resin pH of the thermoplastic resin composition can be adjusted, for example, by adjusting the resin pH of the constituent graft copolymer (B) or copolymer (C), which can be adjusted in the same manner as the method for adjusting the resin pH of the graft copolymer (B). Alternatively, the resin pH can be adjusted by adding an acidic additive such as diphosphoric acid to the thermoplastic resin composition.

[0064] The thermoplastic resin composition thus obtained can be molded into a molded article by injection molding, extrusion molding, compression molding, injection compression molding, blow molding, or the like. [Example]

[0065] The present invention will be described in detail below using examples, but the present invention is not limited to these examples. In the examples, parts and percentages are by weight. In addition, various physical properties in each of the examples and comparative examples were measured by the following methods.

[0066] Charpy impact strength (NC) Using the pellets obtained in each example and comparative example, various test pieces were molded in accordance with ISO test method 294, and the notched Charpy impact values ​​of 4 mm thick test pieces were measured in accordance with ISO test method 179. Unit: kJ / m 2

[0067] Heat deflection temperature (HDT) Using the pellets obtained in each example and comparative example, various test pieces were molded in accordance with ISO test method 294, and the deflection temperature under load of 1.8 MPa was measured in accordance with ISO 75. Unit: °C

[0068] thermal stability Using an injection molding machine (Japan Steel Works, Ltd. J-180ADS, molding temperature 290°C, mold temperature 60°C), flat plate test pieces (length x width x thickness = 400 mm x 100 mm x 3 mm) were molded under the following conditions. When the weight of the material for the molded product was taken as 100%, approximately 140% was weighed and molded. Next, approximately 140% was weighed out so as to include the approximately 40% of the resin remaining in the cylinder, and then the weighed amount was retained for 270 seconds and molded at a firing speed of 30 mm / s. The appearance of the obtained molded product was visually inspected for defects. Appearance defects were evaluated as follows. 〇: No silver dots on the surface of the molded product △: There are 1 to 10 silver dots on the surface of the molded product ×: There are 10 or more silver dots on the surface of the molded product

[0069] Dimensional stability The linear expansion coefficient was measured to evaluate the dimensional stability. Type A1 dumbbells according to JIS K7139 were molded in accordance with ISO test method 294. Samples were cut from the center of the dumbbells, and the linear expansion coefficient in the MD direction (direction of resin flow) was measured in accordance with JIS K7197. A thermal analyzer, TMA-7100 manufactured by Hitachi High-Tech Science Corporation, was used. The lower the value, the better the dimensional stability, and the evaluation was performed as follows: 〇: Linear expansion coefficient is 5×10 -5 / ℃ △: Linear expansion coefficient is 5×10 -5 / ℃ or more 7×10 -5 / ℃ or less ×: Linear expansion coefficient is 7×10 -5 / ℃

[0070] weather resistance For the weather resistance test, pellets obtained in each example and comparative example were used in an injection molding machine (SAV-30-30, cylinder temperature 250°C, mold temperature 60°C) to mold molded articles (length x width x thickness = 90 mm x 55 mm x 2.5 mm). A Sunshine Weather Meter S80HBB manufactured by Suga Test Instruments Co., Ltd. was used to conduct an accelerated exposure test for 500 hours under conditions of a BPT of 63°C and rain. The color difference (ΔE) of the molded article surface before and after exposure was then measured using the SCE method. The color difference was evaluated using a spectrophotometer (CMS-35SP JC2 manufactured by Murakami Color Research Laboratory Co., Ltd.) as follows: ○: ΔE is less than 7 △: ΔE is 7 to 15 ×: ΔE exceeds 15

[0071] resin pH The resin pH of the graft copolymer (B) and the thermoplastic resin composition was measured as follows. (1) 1 g of the graft copolymer (B) or the thermoplastic resin composition and 40 ml of primary tetrahydrofuran (containing a stabilizer) were added to a 100 ml Erlenmeyer flask and allowed to stand for 24 hours. (2) Add 40 ml of first-grade methanol to a 200 ml beaker and stir with a magnetic stirrer. Add the sample obtained in (1) and then add 40 ml of pure water and stir. (3) The pH of the sample obtained in (2) was measured in accordance with JIS Z-8802 using a desktop electrical conductivity meter (CM-25R, manufactured by Toa DKK Co., Ltd.).

[0072] Polycarbonate resin (A) A polycarbonate resin made from phosgene and bisphenol A with a viscosity average molecular weight of 20,500.

[0073] Preparation of graft copolymer (B-1) A glass reactor was charged with 60 parts by weight of coagulated and agglomerated styrene-butadiene rubber (b-1) latex (styrene 5% by weight, butadiene 95% by weight, mass average particle diameter 440 nm) in terms of solids, stirring was initiated, and nitrogen substitution was performed. After nitrogen substitution, the temperature inside the reactor was raised to 65 °C, and when it reached 65 °C, an aqueous solution containing 0.06 parts by weight of glucose, 0.03 parts by weight of anhydrous sodium pyrophosphate, and 0.001 parts by weight of ferrous sulfate dissolved in 10 parts by weight of deionized water was added, and the temperature was then raised to 70 °C. Subsequently, a mixture of 10 parts by weight of acrylonitrile, 30 parts by weight of styrene, 0.3 parts by weight of tertiary dodecyl mercaptan, and 0.1 parts by weight of t-butyl hydroperoxide and an emulsifier aqueous solution containing 1.0 parts by weight (solids equivalent) of potassium oleate dissolved in 20 parts by weight of deionized water were continuously added dropwise over 4 hours. After the dropwise addition, the mixture was maintained for 3 hours to obtain a graft copolymer (B-1) latex. Then, deionized water was added to 100 parts by mass (solids content) of the obtained graft copolymer (B-1) latex so that the final slurry concentration was 23%, and 4.5 parts by mass of magnesium sulfate and 0.8 parts by mass of 10% sulfuric acid were added, followed by heating to 93°C. The graft copolymer (B-1) latex was then added and coagulated to obtain a polymer-containing slurry. The resulting slurry was then dehydrated and dried to obtain a graft copolymer (B-1) powder. The graft rate of the obtained graft copolymer (B-1) was 42%, the reduced viscosity of the acetone-soluble portion was 0.28 dl / g, and the resin pH was 5.4. The mass average particle size of the aggregated and thickened styrene-butadiene rubber latex was determined as follows. The samples were stained with osmium tetroxide (OsO4), dried, and then photographed using a transmission electron microscope. The area of ​​800 rubber particles was measured using an image analysis processor (IP-1000PC, manufactured by Asahi Kasei Corporation), and their equivalent circle diameters (diameters) were calculated to calculate the mass-average particle diameter.

[0074] Preparation of graft copolymer (B-2) Deionized water was added to 100 parts by mass (solids) of the obtained graft copolymer (B-1) latex to a final slurry concentration of 23%, and 4.5 parts by mass of magnesium sulfate was added and heated to 93°C. The graft copolymer (B-1) latex was then added and coagulated to obtain a polymer-containing slurry. The resulting slurry was then dehydrated and dried to obtain a powder of graft copolymer (B-2). The graft rate of the obtained graft copolymer (B-2) was 42%, the reduced viscosity of the acetone-soluble portion was 0.28 dL / g, and the resin pH was 8.4.

[0075] Preparation of copolymer (C) A copolymer (C) consisting of 75 parts by mass of styrene and 25 parts by mass of acrylonitrile was obtained by a known bulk polymerization method. The copolymer (C) obtained by the above method had a reduced viscosity of 0.50 dL / g.

[0076] Talc (D) Talc: UPN-HST 0.5, manufactured by Hayashi Kasei Co., Ltd.

[0077] Phosphate Compounds (E) Fujifilm Wako Pure Chemical Industries, Ltd., diphosphate

[0078] Other additives Aromatic condensed phosphate ester: PX-200, manufactured by Daihachi Chemical Industry Co., Ltd.

[0079] Examples 1 to 7 and Comparative Examples 1 to 5 Polycarbonate resin (A), graft copolymer (B), copolymer (C), talc (D), phosphoric acid compound (E), and other additives were mixed in the proportions shown in Table 1, and then melt-kneaded and pelletized in a φ26 mm twin-screw extruder set at a cylinder temperature of 260°C, a main screw rotation speed of 450 rpm, and a discharge rate of 30 kg / hr. These pellets were then molded in an injection molding machine to prepare various test specimens for evaluation.

[0080] [Table 1]

[0081] As is clear from Table 1, Examples 1 to 7, which used the thermoplastic resin composition of the present invention, provided an excellent balance of impact resistance, heat resistance, weather resistance, dimensional stability, and thermal stability.

[0082] Regarding the thermoplastic resin composition according to the first aspect of the present invention, In Comparative Examples 1 to 3, the resin pH of the thermoplastic resin compositions was outside the specified range, and the thermostability was poor. Comparative Example 4 was poor in dimensional stability and weather resistance because talc (D) was not added. In Comparative Example 5, the amount of talc (D) added exceeded the specified range, and therefore the impact resistance was poor.

[0083] Regarding the thermoplastic resin composition according to the second aspect of the present invention, In Comparative Examples 1 and 2, the resin pH of the thermoplastic resin compositions was outside the specified range, and the thermostability was poor. In Comparative Example 3, the amount of the phosphoric acid compound (E) added exceeded the specified range, and therefore the thermal stability was poor. Comparative Example 4 was poor in dimensional stability and weather resistance because talc (D) was not added. In Comparative Example 5, the amount of talc (D) added exceeded the specified range, and therefore the impact resistance was poor.

[0084] Regarding the thermoplastic resin composition according to the third aspect of the present invention, In Comparative Example 1, the resin pH of the graft copolymer (B) was outside the specified range, and the thermal stability was poor. Comparative Example 2 was poor in thermal stability because no phosphoric acid compound (E) was added. In Comparative Example 3, the amount of the phosphoric acid compound (E) added exceeded the specified range, and therefore the thermal stability was poor. Comparative Example 4 was poor in dimensional stability and weather resistance because talc (D) was not added. Comparative Example 5 had poor impact resistance because the amount of talc (D) added exceeded the specified range. [Industrial Applicability]

[0085] As described above, the thermoplastic resin composition of the present invention is a thermoplastic resin composition having an excellent balance of impact resistance, heat resistance, weather resistance, dimensional stability, and thermal stability, and therefore can be suitably used as a material for large molded parts to be used outdoors, such as vehicle exterior parts.

Claims

1. A thermoplastic resin composition comprising a polycarbonate resin (A), a graft copolymer (B), a copolymer (C), and talc (D), and satisfying the following conditions (1) to (8): (1) The content of the polycarbonate resin (A) is 40 to 80% by mass in a total of 100% by mass of (A), (B), (C) and (D). (2) The graft copolymer (B) is a graft copolymer obtained by graft polymerization of a rubber polymer (b-1) and a monomer component (b-2) containing at least one monomer selected from the group consisting of an aromatic vinyl monomer, a vinyl cyanide monomer, and a (meth)acrylic acid ester monomer. (3) The content of the graft copolymer (B) is 5 to 45% by mass based on 100% by mass of the total of (A), (B), (C) and (D). (4) The copolymer (C) is a copolymer obtained by polymerizing a monomer component containing an aromatic vinyl monomer and a vinyl cyanide monomer. (5) The content of copolymer (C) is more than 0% by mass and not more than 39% by mass in 100% by mass of the total of (A), (B), (C), and (D). (6) The content of talc (D) is 5 to 30% by mass based on 100% by mass of the total of (A), (B), (C), and (D). (7) Contains 3 to 13 parts by mass of an aromatic condensed phosphate ester (excluding compounds in which a hydroxyl group and an oxo group are bonded to a phosphorus atom) per 100 parts by mass of the total of (A), (B), (C), and (D). (8) The thermoplastic resin composition has a pH of 5.0 to 6.

8.

2. The thermoplastic resin composition according to claim 1, characterized in that it contains 0.01 to 1.5 parts by mass of a phosphoric acid compound (E) per 100 parts by mass of the total of (A), (B), (C), and (D).

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