Thermoplastic resin composition and molded article thereof

Abstract

The present invention provides a thermoplastic resin composition which exhibits excellent weather resistance, heat and humidity aging resistance, impact resistance, and heat resistance and a molded article which is obtained by molding the thermoplastic resin composition. Provided is a thermoplastic resin composition characterized by comprising 1-50 parts by mass of a specific polycarbonate resin (A) including an isosorbide structure, 10-45 parts by mass of a graft copolymer (B) obtained by graft polymerization of a rubbery polymer (a) and monomers (b) including an aromatic vinyl-based monomer and a vinyl cyanide-based monomer, 5-49 parts by mass of an aromatic vinyl-vinyl cyanide-based copolymer (C) obtained by copolymerization of monomers (c) including an aromatic vinyl-based monomer and a vinyl cyanide-based monomer, and 0-40 parts by mass of an aromatic polycarbonate resin (D) (wherein the total of the polycarbonate resin (A), the graft copolymer (B), the aromatic vinyl -vinyl cyanide-based copolymer (C), and the aromatic polycarbonate resin (D) is 100 parts by mass ). Also provided is a molded article which is obtained by molding the thermoplastic resin composition.

Description

Thermoplastic resin composition and molded article thereof

[0001] The present invention relates to a thermoplastic resin composition having excellent weather resistance, resistance to moist heat aging, impact resistance, and heat resistance, and to a molded article obtained by molding this thermoplastic resin composition.

[0002] In recent years, in order to realize a sustainable society, there has been a call to eliminate or reduce the environmental burden, particularly carbon dioxide emissions, which has become a major global issue. In particular, there has been a shift from petroleum-derived plastics to plant-derived materials for resin parts in automobiles, electrical appliances, and other products.

[0003] Plant-derived materials designed to reduce environmental impact have already been put to practical use, and examples of materials that have been developed include polylactic acid resin, polyamide 11 resin made from plant-derived monomers, and polycarbonate resin that uses plant-derived isosorbide structures.

[0004] When these plant-derived materials have low impact strength, they can be used while being compensated for by designing the part shape, etc., and development is also underway to increase the strength of the material itself. In particular, materials for various industrial applications, especially automotive resin parts, are required to exhibit excellent impact resistance while also being weather-resistant so that the parts do not discolor even when exposed to direct sunlight, and heat-resistant so that they do not deform even when exposed to high temperatures due to direct sunlight. Furthermore, from the perspective of product safety, materials with little change in properties over the long term are required. There is also a demand for the use of recycled raw materials and for the increased recyclability of the resins themselves used in products.

[0005] As described above, industrial resins are required to have many properties, but it is difficult to satisfy all of them.

[0006]

[0004] Against this background, for example, Patent Document 1 discloses a thermoplastic resin composition containing a polycarbonate resin having an isosorbide structure, an AES graft copolymer, and an aromatic polycarbonate resin. However, when the amount of the polycarbonate resin having an isosorbide structure used in this thermoplastic resin composition is increased to around 50%, it is difficult to achieve sufficient moist heat aging resistance while maintaining the properties of impact strength, heat resistance, and weather resistance. This has resulted in a problem of limited applications due to the lack of moist heat aging resistance.

[0007] JP 2016-44221 A

[0008] The present invention aims to provide a thermoplastic resin composition having excellent weather resistance, moist heat aging resistance, impact resistance, and heat resistance, and a molded article obtained by molding the thermoplastic resin composition. Another object of the present invention is to provide a thermoplastic resin composition having excellent recyclability and a molded article thereof.

[0009] The present inventors have found that the above-mentioned problems can be solved by blending in a predetermined ratio a polycarbonate resin (A) containing an isosorbide structure, a graft copolymer (B) obtained by graft polymerizing a rubbery polymer (a) with a monomer (b) containing an aromatic vinyl monomer and a vinyl cyanide monomer, an aromatic vinyl-vinyl cyanide copolymer (C) obtained by copolymerizing a monomer containing an aromatic vinyl monomer and a vinyl cyanide monomer, and an aromatic polycarbonate resin (D).

[0010] The present invention provides the following.

[0011] [1] A polycarbonate resin (A) containing an isosorbide structure, the polycarbonate resin (A) containing 65 to 75 mol % of structural units derived from a dihydroxy compound represented by the following formula (1) among all structural units derived from dihydroxy compounds constituting the polycarbonate resin (A) and containing 0.01 to 0.1 mass % of a benzotriazole-based compound, and a rubber-like polymer (a) graft-polymerized with a monomer (b) containing an aromatic vinyl-based monomer and a vinyl cyanide-based monomer. A thermoplastic resin composition comprising: 10 to 45 parts by mass of a graft copolymer (B); 5 to 49 parts by mass of an aromatic vinyl-vinyl cyanide copolymer (C) obtained by copolymerizing a monomer (c) containing an aromatic vinyl monomer and a vinyl cyanide monomer; and 0 to 40 parts by mass of an aromatic polycarbonate resin (D), wherein the total amount of the polycarbonate resin (A), the graft copolymer (B), the aromatic vinyl-vinyl cyanide copolymer (C), and the aromatic polycarbonate resin (D) is 100 parts by mass.

[0012]

[0013] [2] The thermoplastic resin composition according to [1], wherein the aromatic vinyl-cyanide vinyl copolymer (C) has a mass average molecular weight (Mw) of 50,000 to 350,000 and a ratio (Mw / Mn) of the mass average molecular weight (Mw) to the number average molecular weight (Mn) of 1.5 to 3.5.

[0014] [3] A molded article obtained by molding the thermoplastic resin composition according to [1] or [2].

[0015] According to the present invention, a thermoplastic resin composition having excellent weather resistance, moist heat aging resistance, impact resistance, and heat resistance, and a molded article thereof are provided. According to the present invention, it is possible to exhibit impact strength, heat resistance, weather resistance, and moist heat aging resistance even when the content of the polycarbonate resin containing an isosorbite structure is increased up to 50%. Furthermore, the thermoplastic resin composition of the present invention is a thermoplastic resin composition having excellent recyclability, which leads to effective utilization of resources.

[0016] The present invention will be described in detail below.

[0017] [Thermoplastic Resin Composition] The thermoplastic resin composition of the present invention (hereinafter may be simply referred to as the "resin composition") comprises, as resin components: 1 to 50 parts by mass of a polycarbonate resin (A) containing an isosorbide structure, in which 65 to 75 mol % of structural units derived from a dihydroxy compound represented by the following formula (1) are contained in all structural units derived from dihydroxy compounds constituting the polycarbonate resin (A), and the polycarbonate resin (A) contains 0.01 to 0.1 mass % of a benzotriazole-based compound (hereinafter may be referred to as the "isosorbide-based polycarbonate resin (A) of the present invention," "isosorbide-based polycarbonate resin (A)," or "component (A)"); 10 to 45 parts by mass of a graft copolymer (B) (hereinafter may be referred to as the "component (B)") obtained by graft polymerizing a rubbery polymer (a) with a monomer (b) containing an aromatic vinyl-based monomer and a vinyl cyanide-based monomer; The composition is characterized by comprising: 5 to 49 parts by mass of an aromatic vinyl-vinyl cyanide copolymer (C) (hereinafter, sometimes referred to as "component (C)") obtained by copolymerizing a monomer containing an aromatic vinyl monomer and a vinyl cyanide monomer; and 0 to 40 parts by mass of an aromatic polycarbonate resin (D) (hereinafter, sometimes referred to as "component (D)"), provided that the total of components (A) to (D) is 100 parts by mass.

[0018] In the thermoplastic resin composition of the present invention, the resin component refers to the total of the isosorbide-based polycarbonate resin (A), the graft copolymer (B), the aromatic vinyl-vinyl cyanide copolymer (C), and the aromatic polycarbonate resin (D). When the thermoplastic resin composition of the present invention contains resins other than those described above, the resin component refers to the total of the other resins.

[0019] [Polycarbonate Resin (A) Containing an Isosorbide Structure] The isosorbide-based polycarbonate resin (A) used in the present invention is a polycarbonate resin containing 65 to 75 mol % of structural units derived from a dihydroxy compound represented by the following formula (1) among all structural units derived from dihydroxy compounds constituting the polycarbonate resin (A). The isosorbide-based polycarbonate resin (A) is preferably a polycarbonate resin containing structural units derived from a dihydroxy compound represented by the following formula (1) and structural units derived from cyclohexanedimethanol.

[0020]

[0021] The dihydroxy compound represented by the formula (1) includes isosorbide, isomannide, and isoidet, which are stereoisomers. These may be used alone or in combination of two or more. Among them, isosorbide, which is obtained by dehydration condensation of sorbitol produced from various starches that are abundant and easily available as plant-derived resources, is most preferred in terms of availability and ease of production, moldability, heat resistance, impact resistance, surface hardness, and carbon neutrality.

[0022] On the other hand, examples of cyclohexanedimethanol include 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol, with 1,4-cyclohexanedimethanol being preferred due to its availability.

[0023] The isosorbide-based polycarbonate resin (A) used in the present invention may contain structural units derived from one or more dihydroxy compounds other than the dihydroxy compound represented by the formula (1) and cyclohexanedimethanol (hereinafter sometimes referred to as "other dihydroxy compounds"). Examples of other dihydroxy compounds include aliphatic dihydroxy compounds such as ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-heptanediol, and 1,6-hexanediol; tricyclodecane dimethanol, pentacyclopentadecanedimethanol, 2,6-decalindimethanol, 1,5-decalindimethanol, and 2,3-decalindimethanol. , 2,3-norbornane dimethanol, 2,5-norbornane dimethanol, 1,3-adamantanedimethanol and other dihydroxy compounds of alicyclic hydrocarbons; 2,2-bis(4-hydroxyphenyl)propane [=bisphenol A], 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-diethylphenyl)propane, 2,2-bis(4-hydroxy-(3,5-diphenyl)phenyl)propane, 2,2 aromatic bisphenols such as 1,1-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxyphenyl)pentane, 2,4'-dihydroxy-diphenylmethane, bis(4-hydroxyphenyl)methane, bis(4-hydroxy-5-nitrophenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 3,3-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)sulfone, 2,4'-dihydroxydiphenylsulfone, bis(4-hydroxyphenyl)sulfide, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dichlorodiphenyl ether, 9,9-bis(4-(2-hydroxyethoxy-2-methyl)phenyl)fluorene, 9,9-bis(4-hydroxyphenyl)fluorene, and 9,9-bis(4-hydroxy-2-methylphenyl)fluorene.

[0024] When the isosorbide-based polycarbonate resin (A) contains structural units derived from the dihydroxy compound represented by formula (1) and structural units derived from cyclohexanedimethanol, it is preferable that the proportion of structural units derived from cyclohexanedimethanol among all structural units derived from dihydroxy compounds contained in the isosorbide-based polycarbonate resin (A) is 35 mol% or less, for example, 25 to 35 mol%, particularly 27 to 32 mol%. By including structural units derived from cyclohexanedimethanol in the isosorbide-based polycarbonate resin (A), discoloration is less likely to occur, and the effects of increasing molecular weight, improving impact strength, and improving glass transition temperature are achieved. If the proportion of structural units derived from cyclohexanedimethanol is too high, the effects of including structural units derived from the dihydroxy compound represented by formula (1) are impaired, which is undesirable.

[0025] From the viewpoints of being less likely to cause coloration, increasing the molecular weight, improving impact strength, and improving the glass transition temperature, the isosorbide-based polycarbonate resin (A) contains 65 to 75 mol % of structural units derived from the dihydroxy compound represented by the formula (1), preferably 68 to 73 mol %, of all structural units derived from dihydroxy compounds contained in the isosorbide-based polycarbonate resin (A).

[0026] Furthermore, when the isosorbide-based polycarbonate resin (A) contains structural units derived from other dihydroxy compounds, the structural units derived from other dihydroxy compounds preferably account for 10 mol% or less, more preferably 5 mol% or less, of all structural units derived from dihydroxy compounds in the isosorbide-based polycarbonate resin (A). When the isosorbide-based polycarbonate resin (A) contains structural units derived from other dihydroxy compounds, the impact resistance and the effect of improving the molded appearance are improved, but if this proportion is too high, the heat resistance is reduced. Furthermore, when the isosorbide-based polycarbonate resin (A) contains structural units derived from aromatic bisphenols as structural units derived from other dihydroxy compounds, the heat resistance is improved, but if this proportion is too high, the impact strength is reduced.

[0027] The isosorbide-based polycarbonate resin (A) of the present invention contains 0.01 to 0.1 mass % of a benzotriazole-based compound. By containing the benzotriazole-based compound, the isosorbide-based polycarbonate resin (A) has excellent weather resistance even when mixed with other resins.

[0028] Specific examples of the benzotriazole compound include 2-(2'-hydroxy-3'-methyl-5'-hexylphenyl)benzotriazole, 2-(2'-hydroxy3'-t-butyl-5'-hexylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-methyl-5'-t-octylphenyl)benzotriazole, 2-(2'hydroxy-5'-t-dodecylphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2-(2'-hydroxy-3'-methyl-5'-t-dodecylphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-butylphenyl)benzotriazole, and methyl-3-(3-(2H-benzotriazol-2-yl)-5-t-butyl-4-hydroxyphenyl)propionate.

[0029] The isosorbide-based polycarbonate resin (A) of the present invention may contain one or more of these benzotriazole-based compounds.

[0030] Commercially available products of such benzotriazole compounds include Adekastab (registered trademark) LA-29 manufactured by ADEKA Corporation.

[0031] The content of the benzotriazole-based compound in the isosorbide-based polycarbonate resin (A) of the present invention is preferably 0.02 to 0.08% by mass, more preferably 0.02 to 0.05% by mass, from the viewpoint of excellent weather resistance even when mixed with other resins.

[0032] The isosorbide-based polycarbonate resin (A) of the present invention contains a benzotriazole-based compound in the content ratio described above, and preferably contains the following fatty acid esters of polyhydric alcohols in the following preferred ratios, and is therefore also called a "polycarbonate resin composition." However, since the contents of these benzotriazole-based compounds and fatty acid esters of polyhydric alcohols in the isosorbide-based polycarbonate resin (A) are very small, it will be called a "polycarbonate resin" in the present invention.

[0033] The isosorbide-based polycarbonate resin (A) of the present invention preferably contains a fatty acid ester of a polyhydric alcohol from the viewpoint of imparting mold releasability during molding.

[0034] In the fatty acid ester of a polyhydric alcohol, the fatty acid is preferably a higher fatty acid, more preferably a saturated fatty acid having 10 to 30 carbon atoms. Examples of such fatty acids include myristic acid, lauric acid, palmitic acid, stearic acid, and behenic acid.

[0035] In the fatty acid ester of a polyhydric alcohol, the polyhydric alcohol is preferably ethylene glycol, which, when added to a resin, can improve the mold releasability without impairing the transparency of the resin.

[0036] As the fatty acid ester of a polyhydric alcohol, a partial or full ester of a polyhydric alcohol having 1 to 20 carbon atoms and a saturated fatty acid having 10 to 30 carbon atoms is preferred. Examples of such partial or full esters of a polyhydric alcohol and a saturated fatty acid include stearic acid monoglyceride, stearic acid diglyceride, stearic acid triglyceride, stearic acid monosorbitate, behenic acid monoglyceride, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tetrastearate, pentaerythritol tetrapelargonate, propylene glycol monostearate, isopropyl palmitate, and sorbitan monostearate. Among these, stearic acid monoglyceride, stearic acid triglyceride, and pentaerythritol tetrapelargonate are preferred. From the viewpoints of heat resistance and moisture resistance, full esters are more preferred as the fatty acid ester of a polyhydric alcohol.

[0037] The isosorbide-based polycarbonate resin (A) of the present invention may contain one kind of fatty acid ester of these polyhydric alcohols, or may contain two or more kinds of fatty acid esters.

[0038] Commercially available fatty acid esters of such polyhydric alcohols include ethylene glycol distearate E-275 manufactured by NOF Corporation.

[0039] The content of the polyhydric alcohol fatty acid ester in the isosorbide-based polycarbonate resin (A) of the present invention is preferably 0.1 to 0.5 mass %, more preferably 0.2 to 0.4 mass %, from the viewpoint of excellent mold releasability during molding.

[0040] The isosorbide-based polycarbonate resin (A) used in the present invention can be produced by a commonly used production method. The production method of the isosorbide-based polycarbonate resin (A) may be either a solution polymerization method using phosgene or a melt polymerization method in which a dihydroxy compound is reacted with a carbonate diester. As a production method of the isosorbide-based polycarbonate resin (A), a melt polymerization method in which a dihydroxy compound including the dihydroxy compound represented by the formula (1) is reacted with a carbonate diester, which is less toxic to the environment, in the presence of a polymerization catalyst is preferred.

[0041] In such a general production method, the isosorbide-based polycarbonate resin (A) suitable for the present invention can be obtained by adding the above-mentioned benzotriazole-based compound and / or a fatty acid ester of a polyhydric alcohol to the reaction system and carrying out the reaction in the presence of these additives, or by adding the above-mentioned benzotriazole-based compound and / or a fatty acid ester of a polyhydric alcohol to the polycarbonate resin obtained after the reaction.

[0042] The carbonate diester used in the melt polymerization method is usually one represented by the following general formula (2): These carbonate diesters may be used alone or in combination of two or more.

[0043]

[0044] (In the general formula (2), A １ , A ２ represents an aliphatic group having 1 to 18 carbon atoms which may have a substituent or an aromatic group which may have a substituent, and A １ and A ２ may be the same or different.)

[0045] Examples of the carbonic acid diester represented by the above general formula (2) include substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate; dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate.

[0046] Among these, diphenyl carbonate and substituted diphenyl carbonates are preferred, with diphenyl carbonate being particularly preferred.

[0047] As the polymerization catalyst (transesterification catalyst) in the melt polymerization, a known alkali metal compound and / or alkaline earth metal compound is used. A basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound can also be used in combination with the alkali metal compound and / or alkaline earth metal compound as an auxiliary.

[0048] The polymerization reaction may be carried out in a known manner, and may be any of a batch method, a continuous method, or a combination of a batch method and a continuous method.

[0049] In the present invention, the mass average molecular weight (Mw) of the isosorbide-based polycarbonate resin (A) is preferably 25,000 to 60,000, more preferably 30,000 to 60,000, and particularly preferably 35,000 to 58,000, from the viewpoint of the appearance and impact resistance of the resulting molded article. If the mass average molecular weight of the isosorbide-based polycarbonate resin (A) is higher than this range, the fluidity decreases. If the mass average molecular weight of the isosorbide-based polycarbonate resin (A) is lower than this range, the impact resistance and heat resistance of the resulting molded article decrease, and the appearance deteriorates.

[0050] Here, the MFR of the isosorbide-based polycarbonate resin (A) can be used as a measure of the mass average molecular weight. The MFR of the isosorbide-based polycarbonate resin (A), measured under the conditions of ISO 1133 (230°C / 2.16 kg), is preferably in the range of 2 to 30 g / 10 min, more preferably 3 to 20 g / 10 min, and even more preferably 4 to 15 g / 10 min. By having the MFR in this range, the thermoplastic resin composition of the present invention can more effectively exhibit excellent performance in terms of fluidity, impact resistance, heat resistance, and appearance.

[0051] Commercially available isosorbide-based polycarbonate resins (A) include D7340R, D6350R, D5360R, and D5380R-3 under the DURABIO (registered trademark) brand manufactured by Mitsubishi Chemical Corporation.

[0052] The isosorbide-based polycarbonate resin (A) may be used alone or in combination of two or more types differing in the types, compositions, physical properties, etc. of constituent components.

[0053] The amount of isosorbide-based polycarbonate resin (A) in the resin composition of the present invention is 1 to 50 parts by mass, preferably 11 to 50 parts by mass, more preferably 21 to 50 parts by mass, and most preferably 26 to 50 parts by mass, per 100 parts by mass of components (A) to (D) combined, because the resulting resin composition and molded articles thereof exhibit excellent molded appearance, impact resistance, and heat resistance. To ensure even better performance, the amount of isosorbide-based polycarbonate resin (A) may be 36 to 50 parts by mass or even 40 to 50 parts by mass, per 100 parts by mass of components (A) to (D) combined. If the amount of isosorbide-based polycarbonate resin (A) is greater than this range, impact resistance and heat resistance decrease. If the amount of isosorbide-based polycarbonate resin (A) is less than this range, the appearance deteriorates.

[0054] [Graft Copolymer (B)] The graft copolymer (B) contained in the thermoplastic resin composition of the present invention is obtained by graft polymerizing a rubbery polymer (a) with a monomer (b) containing an aromatic vinyl monomer and a vinyl cyanide monomer.

[0055] Examples of the rubbery polymer (a) that forms the graft copolymer (B) include diene-based rubbers such as polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, acrylic ester-butadiene copolymer, styrene-isoprene copolymer, and natural rubber; acrylic rubbers such as polybutyl acrylate; olefin-based rubbers such as ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, and ethylene-α-olefin copolymer; and silicone-based rubbers such as polyorganosiloxane. These may be used alone or in combination of two or more. The rubbery polymer (a) may also have a composite structure, such as a polymerized acrylic ester on polybutadiene or a polymerized acrylic ester on polyorganosiloxane. Among these rubbery polymers (a), acrylic rubbers, silicone rubbers, and olefin-based rubbers are preferred because the resulting resin compositions have excellent weather resistance.

[0056] The volume average particle diameter of the rubber polymer (a) is preferably 90 to 460 nm, more preferably 100 to 440 nm, and even more preferably 120 to 390 nm. When the volume average particle diameter of the rubber polymer (a) is within the above range, the impact resistance and molded appearance of the resulting resin composition and molded article are improved.

[0057] The volume average particle size of the rubbery polymer (a) is measured by the method described in the Examples section below.

[0058] The method for controlling the particle size of the rubber polymer (a) is not particularly limited, and known methods can be used. In particular, methods such as adjusting the type or amount of emulsifier used in producing an emulsified latex of the rubber polymer (a), the shear force applied during kneading, temperature conditions, and moisture content are preferred because they allow for easy control of the particle size. Increasing the amount of emulsifier used, increasing the shear force applied during kneading, raising the temperature, or increasing the moisture content tends to reduce the particle size of the rubber polymer (a).

[0059] The method for producing the emulsified latex of the rubber polymer (a) is not particularly limited, and known methods can be used. For example, emulsion polymerization in an aqueous medium, a method in which the rubber polymer (a) and an emulsifier are melt-kneaded using known melt-kneading means such as a kneader, a Banbury mixer, or a multi-screw extruder, and then dispersed by applying mechanical shear force, and then added to an aqueous medium; a method in which the rubber polymer (a) is dissolved together with an emulsifier in a hydrocarbon solvent such as pentane, hexane, heptane, benzene, toluene, or xylene, and then added to an aqueous medium to emulsify, followed by thorough stirring and distilling off the hydrocarbon solvent; etc. are mentioned. In terms of easy control of particle size, emulsion polymerization in an aqueous medium is preferred for diene rubbers, acrylic rubbers, silicone rubbers, and rubbers in the form of composites thereof. In the case of silicone rubber, olefin rubber, and rubbers in a composite form thereof, a preferred method is to melt-knead the rubbery polymer (a) and the emulsifier using a known melt-kneading means such as a kneader, a Banbury mixer, a multi-screw extruder, etc., to disperse the polymer by applying mechanical shear force, and then add the resulting mixture to an aqueous medium. From the viewpoint of kneading properties, a wax component such as maleic anhydride-modified polyethylene may be used together with the emulsifier during melt-kneading.

[0060] The emulsifier that can be used when emulsifying the rubber polymer (a) may be any commonly used emulsifier, and examples thereof include known ones such as long-chain alkyl carboxylate salts, alkyl sulfosuccinate salts, and alkylbenzene sulfonates.

[0061] There are no particular limitations on whether the rubber polymer (a) is crosslinked. The rubber polymer (a) is preferably crosslinked because it provides excellent impact resistance and color development. The gel content of the rubber polymer (a) is preferably 60 to 99% by mass, and more preferably 80 to 98% by mass.

[0062] The gel content of the rubber polymer (a) indicates the degree of crosslinking of the rubber polymer (a). Specifically, the weighed rubber polymer (a) is dissolved in a suitable solvent for 40 hours, then separated using a 200-mesh wire netting, and the insoluble matter remaining on the wire netting is dried and weighed, and the gel content of the rubber polymer (a) is determined as the ratio (mass%) of the dried insoluble matter to the rubber polymer (a) before dissolving in the solvent. For example, the solvent used to dissolve the rubber polymer (a) is toluene, which makes measurement easy for diene rubbers and olefin rubbers. For acrylic rubbers, acetone is used, which makes measurement easy.

[0063] The method for crosslinking the rubbery polymer (a) is not particularly limited, and known methods can be used. For example, a method for adjusting the amount of organic peroxide or chain transfer agent added during emulsion polymerization of diene rubber, a method for copolymerizing diene rubber or acrylic rubber with a polyfunctional compound during polymerization, or a method for adding an organic peroxide and, if necessary, a polyfunctional compound to diene rubber, silicon rubber, or olefin rubber and heating the mixture are preferred because they make it easy to adjust the degree of crosslinking.

[0064] The organic peroxide is not particularly limited, and examples thereof include peroxyester compounds, peroxyketal compounds, dialkyl peroxide compounds, etc. These compounds may be used alone or in combination.

[0065] The organic peroxide is preferably used in the range of 0.01 to 5 parts by mass per 100 parts by mass of the rubber polymer (a), from the viewpoints that the gel content of the rubber polymer (a) can be easily adjusted to the range of 40 to 99% by mass and that impact resistance can be easily exhibited. Similarly, the polyfunctional compound is preferably used in the range of 10 parts by mass or less per 100 parts by mass of the rubber polymer (a), from the viewpoints that the gel content of the rubber polymer (a) can be easily adjusted to the range of 40 to 99% by mass and that impact resistance can be easily exhibited.

[0066] Graft polymerization of the rubbery polymer (a) with the monomer (b) produces a graft copolymer (B). The monomer (b) contains an aromatic vinyl monomer and a vinyl cyanide monomer, and may contain other monomers.

[0067] Examples of aromatic vinyl monomers include styrene, α-methylstyrene, o-, m-, or p-methylstyrene, vinylxylene, pt-butylstyrene, and ethylstyrene. One or more of these can be used. Among these, styrene and α-methylstyrene are preferred.

[0068] Examples of vinyl cyanide monomers include acrylonitrile, methacrylonitrile, etc. One or more of these may be used.

[0069] The other monomer is a monomer copolymerizable with the vinyl cyanide monomer and the aromatic vinyl monomer. Examples of the other monomer copolymerizable with the vinyl cyanide monomer and the aromatic vinyl monomer include methacrylic acid esters such as methyl methacrylate and methyl acrylate, acrylic acid esters, and maleimide compounds such as N-phenylmaleimide and N-cyclohexylmaleimide.

[0070] The content ratio of the vinyl cyanide monomer and the aromatic vinyl monomer in 100% by mass of the monomer (b) is preferably 70 to 82% by mass of the aromatic vinyl monomer and 18 to 30% by mass of the vinyl cyanide monomer. When the content ratio of the aromatic vinyl monomer and the vinyl cyanide monomer in the monomer (b) is within the above ranges, the molded appearance and impact resistance of the obtained resin composition are further improved.

[0071] When the monomer (b) contains the above-mentioned other monomers, it is preferable for the purpose of achieving the object of the present invention that the content of the other monomers in 100% by mass of the monomer (b) is 30% by mass or less, particularly 20% by mass or less, and especially 10% by mass or less. In this case, it is preferable that the aromatic vinyl monomer and the vinyl cyanide monomer in the monomer (b) account for 70 to 82% by mass and 18 to 30% by mass, respectively, based on a total of 100% by mass of the aromatic vinyl monomer and the vinyl cyanide monomer.

[0072] The graft copolymer (B) is obtained by graft polymerizing the monomer (b) in the presence of the rubber polymer (a). During the graft polymerization, the proportion of the rubber polymer (a) is preferably 40 to 80% by mass, and the proportion of the monomer (b) is preferably 20 to 60% by mass (where the total of the rubber polymer (a) and the monomer (b) is 100% by mass). In general, if the proportion of the rubber polymer (a) is within the above range, the productivity of the graft copolymer (B) is good, and the molded appearance and impact resistance of the resulting resin composition and molded articles thereof are improved.

[0073] The graft copolymer (B) preferably has a graft ratio of 20 to 100%, more preferably 30 to 60%, in order to improve the molded appearance and impact resistance of the resulting resin composition and molded articles thereof.

[0074] The graft ratio (G) in this specification is calculated by the following formula: G=100(P-E) / E P: mass of acetone insoluble matter (mass (g) obtained by washing the graft copolymer (B) or the resin composition with methanol, extracting it with acetone, separating it into an acetone soluble matter and an acetone insoluble matter using a centrifuge, and then vacuum-drying the resulting acetone insoluble matter) E: mass (g) of the rubber polymer (a) used in producing the graft copolymer (B)

[0075] The graft copolymer (B) is produced by a known method such as bulk polymerization, solution polymerization, bulk suspension polymerization, suspension polymerization, emulsion polymerization, etc. Emulsion polymerization is preferred in that the particle size can be easily controlled and polymerization can be easily carried out.

[0076] The content of the vinyl cyanide monomer in the acetone-soluble portion of the graft copolymer (B) of the present invention is preferably 18 to 30% by mass based on 100% by mass of the acetone-soluble portion. The mass-average molecular weight (Mw) of the copolymer component of the acetone-soluble portion of the graft copolymer (B) is preferably in the range of 40,000 to 200,000, more preferably 50,000 to 160,000, and even more preferably 60,000 to 120,000. When the mass-average molecular weight of the acetone-soluble portion is within this range, the thermoplastic resin composition exhibits excellent impact resistance, heat resistance, and moist heat aging resistance.

[0077] The molecular weight distribution (Mw / Mn), which is the ratio of the mass average molecular weight (Mw) to the number average molecular weight (Mn) of the copolymer component in the acetone soluble fraction, is preferably in the range of 1.8 to 4.5, more preferably in the range of 2.0 to 3.0. When the molecular weight distribution is within this range, the excellent impact resistance, heat resistance, and moist heat aging resistance of the thermoplastic resin composition can be more effectively exhibited.

[0078] The mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the copolymer component in the acetone soluble fraction are measured by the methods described in the Examples section below.

[0079] The graft copolymer (B) may be used singly or in the form of a mixture of two or more different types of constituent components, compositions, physical properties, etc.

[0080] The amount of graft copolymer (B) in the resin composition of the present invention is 10 to 45 parts by mass, preferably 10 to 40 parts by mass, more preferably 10 to 35 parts by mass, and most preferably 10 to 30 parts by mass, per 100 parts by mass of the total of components (A) to (D), in order to obtain excellent molded appearance, impact resistance, and heat resistance of the resulting resin composition and molded articles thereof. If the amount of graft copolymer (B) is less than the above lower limit, impact resistance tends to be poor. If the amount of graft copolymer (B) is more than the above upper limit, molded appearance tends to be poor.

[0081] [Aromatic styrene-vinyl cyanide copolymer (C)] The aromatic styrene-vinyl cyanide copolymer (C) of the present invention is a copolymer of an aromatic vinyl monomer and a monomer (c) containing a vinyl cyanide monomer. The monomer (c) may contain other copolymerizable monomers.

[0082] Examples of aromatic vinyl monomers constituting the aromatic styrene-vinyl cyanide copolymer (C) include vinyl toluenes such as styrene, α-methylstyrene, and p-methylstyrene; halogenated styrenes such as p-chlorostyrene; p-t-butylstyrene, dimethylstyrene, and vinyl naphthalenes. These may be used alone or in combination of two or more. Of these, styrene and α-methylstyrene are preferred as aromatic vinyl monomers.

[0083] Examples of the vinyl cyanide monomer constituting the aromatic styrene-vinyl cyanide copolymer (C) include acrylonitrile, methacrylonitrile, etc. These may be used alone or in combination of two or more. Of the vinyl cyanide monomers, acrylonitrile is preferred.

[0084] The monomer (c) may contain, in addition to the vinyl cyanide monomer and the aromatic vinyl monomer, other monomers copolymerizable therewith, such as methacrylic acid esters and acrylic acid esters, such as methyl methacrylate and methyl acrylate, and maleimide compounds, such as N-phenylmaleimide and N-cyclohexylmaleimide.

[0085] The proportions of the aromatic vinyl monomer and the vinyl cyanide monomer in 100% by mass of the monomer (c) are preferably 60 to 85% by mass of the aromatic vinyl monomer and 15 to 40% by mass of the vinyl cyanide monomer, more preferably 65 to 80% by mass of the aromatic vinyl monomer and 20 to 35% by mass of the vinyl cyanide monomer, and even more preferably 68 to 77% by mass of the aromatic vinyl monomer and 23 to 32% by mass of the vinyl cyanide monomer (provided that the total of the aromatic vinyl monomer and the vinyl cyanide monomer is 100% by mass). When the proportions of the aromatic vinyl monomer and the vinyl cyanide monomer are within the above ranges, the thermoplastic resin composition exhibits an excellent appearance and can exhibit excellent effects in impact resistance, moist heat aging resistance, and recyclability.

[0086] When the monomer (c) contains the above-mentioned other monomers, it is preferable for the purpose of achieving the object of the present invention that the content of the other monomers in 100% by mass of the monomer (c) is 20% by mass or less, particularly 10% by mass or less, and especially 5% by mass or less. In this case, the content of the aromatic vinyl monomer and the vinyl cyanide monomer in the monomer (c) is preferably 60 to 85% by mass and 15 to 40% by mass, more preferably 65 to 80% by mass and 20 to 35% by mass, and even more preferably 68 to 77% by mass and 23 to 32% by mass, based on the total 100% by mass of the aromatic vinyl monomer and the vinyl cyanide monomer.

[0087] There are no particular limitations on the method for producing the aromatic styrene-vinyl cyanide copolymer (C). The aromatic styrene-vinyl cyanide copolymer (C) is produced by a known method such as bulk polymerization, solution polymerization, bulk suspension polymerization, suspension polymerization, or emulsion polymerization in the presence of the monomer (c) and, if necessary, a polymerization initiator, a chain transfer agent, or a suspension stabilizer. Of these methods, suspension polymerization is preferred because it produces fewer impurities such as oligomers, solvents, and emulsifiers. The suspension polymerization method was also used as the production method in the examples described below.

[0088] Known chain transfer agents can be used, such as mercaptans such as n-octyl mercaptan, n-dodecyl mercaptan, and t-dodecyl mercaptan, terpene compounds such as terpinolene, and α-methylstyrene dimer. Known polymerization initiators can also be used. Examples of polymerization initiators include organic peroxides such as benzoyl peroxide and lauroyl peroxide, and azo initiators such as azobisisobutyronitrile.

[0089] Known suspension stabilizers can be used in suspension polymerization, including, for example, organic polymeric substances such as polyvinyl alcohol, polyacrylates, carboxymethyl cellulose, gelatin, and tragacanth; inorganic colloidal substances such as barium sulfate, magnesium carbonate, and calcium phosphate; and combinations of these with surfactants.

[0090] The mass average molecular weight (Mw) of the aromatic styrene-vinyl cyanide copolymer (C) is preferably in the range of 50,000 to 350,000, more preferably 100,000 to 300,000, and even more preferably 150,000 to 250,000. When the mass average molecular weight of the aromatic styrene-vinyl cyanide copolymer (C) is within this range, the excellent impact resistance, heat resistance, and moist heat aging resistance of the thermoplastic resin composition are more effectively exhibited. Furthermore, these properties are less susceptible to the effects of molding temperature and environmental conditions.

[0091] The molecular weight distribution (Mw / Mn), which is the ratio of the mass average molecular weight (Mw) to the number average molecular weight (Mn) of the aromatic styrene-vinyl cyanide copolymer (C), is preferably in the range of 1.5 to 3.5, more preferably 2.0 to 3.0. When the molecular weight distribution (Mw / Mn) of the vinyl cyanide-aromatic vinyl copolymer (B) is within this range, the excellent impact resistance, heat resistance, and moist heat aging resistance of the thermoplastic resin composition are more effectively exhibited. Furthermore, these properties are less susceptible to the effects of molding temperature and environmental conditions.

[0092] The mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the vinyl cyanide-aromatic vinyl copolymer (B) are measured by the methods described in the Examples section below.

[0093] The aromatic vinyl-vinyl cyanide copolymer (C) may be used alone or in combination of two or more different types of constituent components, compositions, physical properties, etc.

[0094] The amount of aromatic vinyl-cyanide vinyl copolymer (C) in the resin composition of the present invention is 5 to 49 parts by mass, preferably 5 to 44 parts by mass, more preferably 5 to 39 parts by mass, and even more preferably 5 to 34 parts by mass, per 100 parts by mass of the total of components (A) to (D). The aromatic styrene-cyanide vinyl copolymer (C) is a component effective in exhibiting the weather resistance, impact resistance, heat resistance, and moist heat aging resistance of the resin composition of the present invention. When the content of the aromatic vinyl-cyanide vinyl copolymer (C) is equal to or greater than the above-mentioned lower limit, the impact resistance, heat resistance, and moist heat aging resistance are good. When the content of the aromatic vinyl-cyanide vinyl copolymer (C) is equal to or less than the above-mentioned upper limit, the impact resistance and fluidity are good.

[0095] [Aromatic Polycarbonate Resin (D)] The aromatic polycarbonate resin (D) is not an essential component of the resin composition of the present invention, but by containing the aromatic polycarbonate (D), the impact resistance of the resin composition and the molded article thereof can be further improved.

[0096] The aromatic polycarbonate (D) used in the present invention can be produced by reacting one or more bisphenols with phosgene or a carbonic acid diester.

[0097] The viscosity average molecular weight (Mv) of the aromatic polycarbonate resin (D) is preferably in the range of 10,000 to 50,000, particularly 15,000 to 40,000. If the viscosity average molecular weight (Mv) of the aromatic polycarbonate (D) is below the above range, the impact resistance tends to decrease. If the viscosity average molecular weight (Mv) of the aromatic polycarbonate (D) is above the above range, the flowability tends to decrease, and the moldability tends to be poor.

[0098] Here, the viscosity average molecular weight of the aromatic polycarbonate resin (D) can usually be calculated by inserting the specific viscosity (ηsp) measured at 20°C and a concentration of 0.7 g / 100 ml (methylene chloride) using methylene chloride as a solvent into the following formula: Viscosity average molecular weight = ([η] x 8130) １．２０５ Here, [η] = [(ηsp × 1.12 + 1) １／２ −1) / 0.56C, where C indicates concentration.

[0099] The mass average molecular weight (Mw) of the aromatic polycarbonate resin (D) is preferably in the range of 12,000 to 80,000, particularly 16,000 to 50,000. If the mass average molecular weight (Mw) of the aromatic polycarbonate resin (D) is below this range, the impact resistance tends to decrease. If the mass average molecular weight (Mw) of the aromatic polycarbonate resin (D) is above this range, the flowability tends to decrease, and the moldability tends to deteriorate.

[0100] The molecular weight distribution (Mw / Mn) of the aromatic polycarbonate resin (D) is preferably in the range of 1.8 to 2.8, particularly 1.9 to 2.3. If the molecular weight distribution (Mw / Mn) is below this range, a large amount of energy is required for production. If the molecular weight distribution (Mw / Mn) is above this range, the resistance to moist heat aging tends to deteriorate.

[0101] Here, the mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the aromatic polycarbonate resin (D) are measured by the methods described in the Examples section below.

[0102] Specific examples of bisphenols that are raw materials for the aromatic polycarbonate resin (D) include hydroquinone, 4,4-dihydroxyphenyl, bis-(4-hydroxyphenyl)-alkane, bis-(4-hydroxyphenyl)-cycloalkane, bis-(4-hydroxyphenyl)-sulfide, bis-(4-hydroxyphenyl)-ether, bis-(4-hydroxyphenyl)-ketone, bis-(4-hydroxyphenyl)-sulfone, and alkyl-substituted, aryl-substituted, and halogen-substituted derivatives thereof. These can be used alone or in combination of two or more.

[0103] The aromatic polycarbonate resin (D) may be used alone or in combination of two or more different types of constituent components, compositions, physical properties, etc.

[0104] The amount of aromatic polycarbonate resin (D) in the resin composition of the present invention is 0 to 40 parts by mass, preferably 5 to 35 parts by mass, more preferably 10 to 30 parts by mass, and even more preferably 15 to 30 parts by mass, per 100 parts by mass of the total of components (A) to (D). If the amount of aromatic polycarbonate (D) in the resin composition exceeds the upper limit, the color development and weather resistance of the resulting resin composition and molded articles thereof tend to be inferior.

[0105] [Resin Components] The thermoplastic resin composition of the present invention exhibits excellent properties by blending an isosorbide-based polycarbonate resin (A), a graft copolymer (B), an aromatic vinyl-vinyl cyanide copolymer (C), and an aromatic polycarbonate resin (D) in predetermined ratios. The thermoplastic resin composition of the present invention further preferably contains the isosorbide-based polycarbonate resin (A) and the aromatic vinyl-vinyl cyanide copolymer (C) in the following amounts:

[0106] In particular, in resin compositions in which the isosorbide-based polycarbonate resin (A) is contained in an amount as high as 36 to 50 parts by mass, and even 40 to 50 parts by mass, per 100 parts by mass of the total of components (A) to (D), the amount of aromatic vinyl-vinyl cyanide copolymer (C) is designed to be preferably 5 to 44 parts by mass, more preferably 5 to 30 parts by mass, even more preferably 6 to 25 parts by mass, and particularly preferably 8 to 20 parts by mass, per 100 parts by mass of the total of components (A) to (D), thereby maximizing the effect of moist heat aging resistance.

[0107] The isosorbide-based polycarbonate resin (A), graft copolymer (B), aromatic vinyl-vinyl cyanide copolymer (C), and aromatic polycarbonate resin (D) that constitute the resin composition of the present invention can be recovered from the market or recycled products as raw materials. Furthermore, the resin composition of the present invention itself is recyclable and can be used as a recycled raw material. Therefore, it is possible to design a thermoplastic resin composition by blending virgin raw materials depending on the application.

[0108] [Other Resins] The resin composition of the present invention may contain other resins in addition to the isosorbide-based polycarbonate resin (A), the graft copolymer (B), the aromatic vinyl-vinyl cyanide resin (B), and the aromatic polycarbonate (D).

[0109] Examples of other resins include impact modifiers with compositions or rubber contents that do not fall under the graft copolymer (B) of the present invention, and polyesters such as polystyrene resins, polyacetal resins, nylon resins, methacrylic resins, polyvinyl chloride resins, polyphenylene ether resins, and polylactic acid resins. Blends of two or more of these resins may also be used. Furthermore, the resins may be modified with compatibilizers or functional groups. The resins may also be recycled resins collected from the market.

[0110] When the resin composition of the present invention contains these other resins, in order to reliably obtain the effects of containing the isosorbide-based polycarbonate resin (A), the graft copolymer (B), the aromatic vinyl-vinyl cyanide-based resin (B), and the aromatic polycarbonate (D), the content of the other resins is preferably 20 parts by mass or less per 100 parts by mass of the total of the resin components, i.e., the isosorbide-based polycarbonate resin (A), the graft copolymer (B), the aromatic vinyl-vinyl cyanide-based copolymer (C), the aromatic polycarbonate resin (D), and the other resins.

[0111] [Additives] The resin composition of the present invention may contain other commonly used additives, such as lubricants, pigments, dyes, fillers (carbon black, silica, titanium oxide, etc.), heat stabilizers, antioxidants for oxidation and degradation, weather resistance agents, release agents, plasticizers, antistatic agents, flame retardants, and flame retardant aids, during production (mixing) or molding, within the range that does not impair the physical properties of the resin composition of the present invention or the molded article.

[0112] [Method for producing resin composition] The resin composition of the present invention can be produced by a known method using a known device. For example, a common method is a melt mixing method. Examples of devices used in this method include an extruder, a Banbury mixer, a roller, a kneader, etc. Either a batch method or a continuous method may be used for mixing. There are no particular limitations on the order in which the components are mixed, as long as all the components are mixed uniformly.

[0113] [Molded Article] The molded article of the present invention is obtained by molding the resin composition of the present invention. Examples of molding methods include injection molding, injection compression molding, extrusion, blow molding, vacuum molding, pressure molding, calendar molding, and inflation molding. Among these, injection molding and injection compression molding are preferred because they are suitable for mass production and can produce molded articles with high dimensional accuracy.

[0114] [Uses] The molded article of the present invention obtained by molding the resin composition of the present invention has excellent weather resistance, moist heat aging resistance, impact resistance, and heat resistance. Furthermore, it also has excellent recyclability. Therefore, the molded article of the present invention obtained by molding the resin composition of the present invention can be used for electrical and electronic parts, automobile parts, mechanical parts, housing parts for office automation equipment or home appliances, general goods, building materials, etc. In particular, the molded article of the present invention obtained by molding the resin composition of the present invention can be used as an automobile part for both interior and exterior use, and is particularly useful as an exterior part due to its excellent weather resistance and moist heat aging resistance.

[0115] The present invention will be described in more detail below with reference to Production Examples, Examples, and Comparative Examples. The present invention is not limited to the following Examples in any way, as long as the gist of the present invention is not exceeded. In the following, "parts" refers to "parts by mass."

[0116] In the following, the volume average particle diameter of the rubber polymer (a) was measured using a "Nanotrac 150" manufactured by Nikkiso Co., Ltd. The gel content of the rubber polymer (a) and the graft ratio of the graft copolymer were each determined by the methods described above. In the following examples, the mass P of the acetone-insoluble fraction in the formula for the graft ratio (G) described above is the mass (g) of each of the graft copolymers (B1) and (B2) after washing with methanol, extracting with acetone, separating into acetone-soluble and acetone-insoluble fractions using a centrifuge, and vacuum-drying the resulting acetone-insoluble fraction.

[0117] The mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the copolymer component of the acetone soluble portion of the graft copolymer (B), the aromatic vinyl-vinyl cyanide copolymer (C), and the aromatic polycarbonate resin (D) were measured by the following methods. <Measurement of Mass Average Molecular Weight (Mw) and Molecular Weight Distribution (Mw / Mn)> The mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were measured using GPC (GPC: "HLC8220" manufactured by Tosoh Corporation, column: "TSK GEL Super HZM-H" manufactured by Tosoh Corporation) and tetrahydrofuran (THF: 40°C) as a solvent. The mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were measured in terms of polystyrene. Regarding the copolymer component of the acetone soluble portion of the graft copolymer (B), the acetone soluble portion in the measurement of the graft ratio of the graft copolymer (B) was precipitated with methanol, and the polymer component was dried in a vacuum dryer for 24 hours and used for the GPC measurement. Regarding the aromatic vinyl-cyanide vinyl copolymer (C), component (C) was also dissolved in acetone, and then the polymer component was precipitated in methanol, and the polymer component was dried in a vacuum dryer for 24 hours and used for the GPC measurement. The aromatic polycarbonate resin (D) was dissolved in tetrahydrofuran (THF), and the polymer component was precipitated in acetone, dried in a vacuum dryer for 24 hours, and used for GPC measurement.

[0118] [Isosorbide-based polycarbonate resin (A)] Isosorbide-based polycarbonate resin (A1): "D7340R" manufactured by Mitsubishi Chemical Corporation (isosorbide / 1,4-cyclohexanedimethanol=70 / 30 (mol %), MFR: 10 g / 10 min (ISO1133 230°C / 2.16 kg)), containing 0.02 mass% of "ADEKA STAB (registered trademark) LA-29" manufactured by ADEKA Corporation as a benzotriazole-based compound and 0.3 mass% of "E-275" ethylene glycol distearate manufactured by NOF Corporation as a fatty acid ester of polyhydric alcohol.

[0119] [Graft Copolymer (B)] <Production Example 1: Graft Copolymer (B1)> (Production of Emulsified Latex of Ethylene-Propylene Copolymer (a-1)) 100 parts of an ethylene-propylene copolymer (ethylene / propylene = 78 / 22 (%), Mooney viscosity (ML1+4, 100 ° C.): 20, melting point (Tm): 40 ° C., glass transition temperature (Tg): -50 ° C.), 10 parts of low molecular weight modified polyethylene ("Hiwax 2203A" manufactured by Mitsui Chemicals, Inc.), and 3.1 parts of potassium oleate were mixed. Next, the mixture was fed at 6 kg / hour from the hopper of a twin-screw extruder ("PCM-30" manufactured by Ikegai Steel Co., Ltd., L / D = 40), and melt-kneaded at a heating temperature of 200 ° C. while continuously feeding a 15% by mass aqueous solution of potassium hydroxide at 110 g / hour. The melt was extruded. The molten material was then continuously fed to a cooling single-screw extruder attached to the tip of the extruder and cooled to 90°C. The removed solid was poured into warm water at 80°C and continuously dispersed to obtain an ethylene-propylene copolymer latex having a volume average particle size of 340 nm. 1.2 parts of t-butylcumyl peroxide and 1.0 part of divinylbenzene were added to 100 parts of the solid content of this latex, and the mixture was reacted at 135°C for 5 hours to prepare a latex of ethylene-propylene copolymer (a-1). The gel content of this ethylene-propylene copolymer (a-1) was 76% by mass. The gel content was determined by coagulating the copolymer latex with dilute sulfuric acid, washing with water, and drying it, followed by sampling 1 g of the copolymer, immersing it in 200 mL of toluene for 40 hours, filtering it through a 200-mesh wire net, drying the residue, and measuring its mass.

[0120] (Production of Graft Copolymer (B1)) 60 parts (solids equivalent) of an emulsified latex of ethylene-propylene copolymer (a-1) (EPR) were charged with 0.16 parts of sodium pyrophosphate, 0.008 parts of ferrous sulfate heptahydrate, and 0.38 parts of fructose, and the internal temperature was maintained at 80°C. A monomer mixture consisting of 30.0 parts of styrene (ST) and 10.0 parts of acrylonitrile (AN), and 0.5 parts of cumene hydroperoxide were simultaneously added dropwise to the mixture through separate feed ports over 140 minutes to carry out polymerization. During this time, the internal temperature was maintained constant at 80°C. After completion of the dropwise addition, the mixture was maintained at 80°C for an additional 100 minutes, after which it was cooled to complete the graft polymerization. The reaction product latex was coagulated with an aqueous sulfuric acid solution, washed with water, and then dried to obtain graft copolymer (B1). The composition (mass ratio) of this graft copolymer (B1) was AN / EPR / ST=9.9 / 60.2 / 29.9, the graft ratio was 44%, and the mass average molecular weight (Mw) of the acetone-soluble portion of the graft copolymer (B1) was 68,000 and the molecular weight distribution (Mw / Mn) was 2.8.

[0121] Production Example 2: Graft Copolymer (B2) A nitrogen-purged reactor was charged with 125 parts of pure water, 0.5 parts of glucose, 0.5 parts of sodium pyrophosphate, 0.005 parts of ferrous sulfate, and 60 parts of polybutadiene latex (a-2) (BD) having a volume average particle size of 340 nm (solids content equivalent: gel content 95%) as the rubber polymer (a), and the temperature inside the reactor was raised to 65°C with stirring. Polymerization was initiated when the internal temperature reached 65°C. Using 29 parts of styrene (ST) and 11 parts of acrylonitrile (AN), 0.25 parts of a t-dodecyl mercaptan mixture as a chain transfer agent were continuously added over 5 hours. Simultaneously, an aqueous solution of cumene hydroperoxide (0.2 parts) and potassium oleate as a polymerization initiator was continuously added over 7 hours, and the reaction was completed. To the obtained latex, 1 part of 2,2'-methylenebis(4-methyl-6-t-butylphenol) was added per 100 parts of the latex solids. Subsequently, this latex was coagulated with sulfuric acid, neutralized with sodium hydroxide, washed, filtered, and dried to obtain a powdery graft copolymer (B2). The composition (mass ratio) of this graft copolymer (B2) was AN / BD / ST = 10.7 / 60.1 / 29.2, and the graft rate was 58%. The mass average molecular weight (Mw) of the acetone-soluble portion of the graft copolymer (B2) was 85,000, and the molecular weight distribution (Mw / Mn) was 3.1.

[0122] [Aromatic Vinyl-Cyanide Copolymer (C)] <Production Example 3: Production of Aromatic Vinyl-Cyanide Copolymer (C1)> A monomer mixture consisting of 120 parts of water, 0.002 parts of sodium alkylbenzenesulfonate, 0.5 parts of polyvinyl alcohol, 0.3 parts of azobisisobutyronitrile, 0.1 parts of t-dodecyl mercaptan, 0.3 parts of terpinolene, 26 parts of acrylonitrile, and 74 parts of styrene was placed in a nitrogen-purged reactor, and the mixture was heated from an initial temperature of 60° C. for 5 hours while gradually adding a portion of the styrene, and then the temperature was raised to 120° C. After a further 4 hours of reaction at 120° C., the polymer was removed to obtain an aromatic vinyl-cyanide copolymer (C1) with an acrylonitrile / styrene ratio of 25.8 / 74.2 (mass ratio). The resulting aromatic vinyl-vinyl cyanide copolymer (C1) had a mass average molecular weight (Mw) of 196,000 and a molecular weight distribution (Mw / Mn) of 2.9.

[0123] Production Example 4: Production of aromatic vinyl-vinyl cyanide copolymer (C2) A monomer mixture consisting of 120 parts of water, 0.002 parts of sodium alkylbenzenesulfonate, 0.5 parts of polyvinyl alcohol, 0.3 parts of azobisisobutyronitrile, 0.4 parts of t-dodecyl mercaptan, 27 parts of acrylonitrile, and 73 parts of styrene was placed in a nitrogen-purged reactor. While gradually adding a portion of the styrene, the mixture was heated from an initial temperature of 60°C for 5 hours, and then reached 120°C. After a further 4 hours of reaction at 120°C, the polymer was removed, yielding an aromatic vinyl-vinyl cyanide copolymer (C2) with an acrylonitrile / styrene ratio of 26.8 / 73.2 (by mass). The resulting aromatic vinyl-vinyl cyanide copolymer (C2) had a mass average molecular weight (Mw) of 132,000 and a molecular weight distribution (Mw / Mn) of 2.0.

[0124] Production Example 5 Production of Aromatic Vinyl-Vinyl Cyanide Copolymer (C3) An aromatic vinyl-vinyl cyanide copolymer (C2) having an acrylonitrile / styrene ratio of 25.5 / 74.5 (mass ratio) was obtained in the same manner as in Production Example 4, except that a monomer mixture consisting of 0.62 parts of t-dodecyl mercaptan, 26 parts of acrylonitrile, and 74 parts of styrene was used. The mass average molecular weight (Mw) of the obtained vinyl cyanide-aromatic vinyl copolymer (C2) was 92,000, and the molecular weight distribution (Mw / Mn) was 2.1.

[0125] [Aromatic Polycarbonate Resin (D)] The following commercially available aromatic polycarbonate resins were used. Aromatic polycarbonate resin (D1): "200-20" manufactured by Sumika Polycarbonate Co., Ltd. (Mw: 36,000, Mw / Mn: 1.9) Aromatic polycarbonate resin (D2): "R-30 (recycled product)" manufactured by Cotec Co., Ltd. (Mw: 39,000, Mw / Mn: 2.1)

[0126] Examples 1 to 13, Comparative Examples 1 to 3 The components were mixed according to the formulations shown in Table 1, and 0.2 parts of ADEKA STAB "2112 (trade name)" (tris(2,4-di-t-butylphenyl)phosphite) manufactured by ADEKA Corporation was further added as a phosphite-based antioxidant. The mixture was melt-kneaded at 260°C using a 28 mm twin-screw extruder ("TEX-28V" manufactured by The Japan Steel Works, Ltd.) to obtain a pelletized resin composition. The obtained resin composition was evaluated for weather resistance, moist heat aging resistance, molded appearance, impact resistance, and heat resistance by the following methods. The evaluation results are shown in Table 1. In Table 1, the numerical values ​​of each component in the composition of the thermoplastic resin composition are expressed in parts.

[0127] <Weather resistance> 100 parts of the obtained resin composition was mixed with 0.8 parts of carbon black to color it, and a black colored plate (test piece) of 100 × 100 mm (thickness 2 mm) was injection molded. This black colored plate (test piece) was treated for 400 hours using a Sunshine Weather Meter (manufactured by Suga Test Instruments Co., Ltd.) under conditions of a black panel temperature of 63 ° C and a cycle condition of 60 minutes (12 minutes of rainfall). The degree of discoloration (ΔE) before and after the treatment was measured and evaluated using a color difference meter. The smaller this value, the better the weather resistance.

[0128] <Humid Heat Aging Resistance> (MFR Increase Rate) Pellets of the obtained resin composition were left for 500 hours in a thermo-hygrostat controlled at 80°C and 95% RH (humid heat aging treatment), and then thoroughly dried at 80°C for 24 hours to obtain moist heat aging treated pellets. The fluidity (MFR) of the moist heat aging treated pellets was measured, and the MFR increase rate was calculated using the measured MFR value of the pellets before moist heat aging treatment (initial) according to the following formula: MFR Increase Rate (%) = {MFR after moist heat aging treatment - initial MFR} / initial MFR × 100 The MFR immediately after production (0 hours after moist heat aging treatment) was taken as the initial value. The lower the MFR increase rate, the better the moist heat aging resistance. (IMP Retention Rate) The pellets after the above-mentioned moist heat aging treatment were injection molded and measured in the same manner as in the impact resistance described below. Using the measured value of the pellets before the moist heat aging treatment (initial), the impact strength (IMP) retention rate was calculated according to the following formula: IMP retention rate (%) = IMP after moist heat aging treatment / initial IMP × 100 The IMP immediately after production (0 hours after moist heat aging treatment) was taken as the initial value. The higher the IMP retention rate, the better the moist heat aging resistance.

[0129] <Molding Appearance> For injection-molded articles of the obtained resin compositions, the reflectance (%) of the surface of the molded article was measured at an incident angle of 60° and a reflection angle of 60° in accordance with JIS K7105 using a "Digital Variable Gloss Meter UGV-5D" manufactured by Suga Test Instruments Co., Ltd. A higher reflectance indicates better surface appearance.

[0130] <Impact Resistance> The injection-molded articles of the obtained resin compositions were subjected to a 4 mm V-notched Charpy impact strength (KJ / m) at 23°C in accordance with ISO test method 179. ２ This value was used as the initial IMP for the IMP retention rate.

[0131] <Heat Resistance> The deflection temperature under load (°C) of the injection molded article of the obtained resin composition was measured in accordance with ISO test method 75 using 1.83 MPa, 4 mm, and the flatwise method.

[0132]

[0133] [Discussion] As shown in Examples 1 to 13 in Table 1, the thermoplastic resin composition and molded article of the present invention not only have excellent weather resistance and molded appearance, but also have excellent impact resistance and moist heat aging resistance. Moreover, even Example 13, which used recycled aromatic polycarbonate resin (D2), exhibits excellent moist heat aging resistance. From these results, it can be seen that the thermoplastic resin composition of the present invention has excellent moist heat aging resistance and exhibits excellent performance maintenance (recyclability) even when the molded article is reused.

[0134] On the other hand, the thermoplastic resin compositions and molded articles of Comparative Examples 1 to 3 were insufficient in at least one of weather resistance and moist heat aging resistance. Additionally, Comparative Example 1 does not contain the isosorbide-based polycarbonate resin (A), and therefore does not achieve sustainability. Comparative Examples 2 and 3 do not contain the aromatic vinyl-vinyl cyanide copolymer (C), and therefore exhibit poor moist heat aging resistance. In particular, Comparative Example 3, which used recycled aromatic polycarbonate resin (D2), is prone to increased fluidity, and it is clear that moist heat aging resistance in impact strength is difficult to achieve.

[0135] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications are possible within the scope of the effects of the invention. This application is based on Japanese Patent Application No. 2024-108366 filed on July 4, 2024, the entire contents of which are incorporated by reference.

Claims

1. 1 to 50 parts by mass of a polycarbonate resin (A) containing an isosorbide structure, wherein the polycarbonate resin (A) contains 65 to 75 mol % of structural units derived from a dihydroxy compound represented by the following formula (1) among all structural units derived from dihydroxy compounds constituting the polycarbonate resin (A), and also contains 0.01 to 0.1 mass % of a benzotriazole-based compound; 10 to 45 parts by mass of a graft copolymer (B) obtained by graft polymerizing a rubbery polymer (a) with a monomer (b) containing an aromatic vinyl-based monomer and a vinyl cyanide-based monomer; 5 to 49 parts by mass of an aromatic vinyl-vinyl cyanide copolymer (C) obtained by copolymerizing a monomer (c) containing an aromatic vinyl-based monomer and a vinyl cyanide-based monomer; and 0 to 40 parts by mass of an aromatic polycarbonate resin (D). A thermoplastic resin composition comprising: (wherein the total amount of the polycarbonate resin (A), the graft copolymer (B), the aromatic vinyl-cyanide vinyl copolymer (C), and the aromatic polycarbonate resin (D) is 100 parts by mass).

2. The thermoplastic resin composition according to claim 1, characterized in that the aromatic vinyl-vinyl cyanide copolymer (C) has a mass average molecular weight (Mw) of 50,000 to 350,000 and a ratio (Mw / Mn) of the mass average molecular weight (Mw) to the number average molecular weight (Mn) of 1.5 to 3.

5.

3. The thermoplastic resin composition according to claim 1, characterized in that the polycarbonate resin (A) contains structural units derived from the dihydroxy compound represented by formula (1) and structural units derived from cyclohexanedimethanol, and the proportion of structural units derived from cyclohexanedimethanol among all structural units derived from dihydroxy compounds contained in the polycarbonate resin (A) is 35 mol % or less.

4. The thermoplastic resin composition according to claim 1, wherein the polycarbonate resin (A) contains 0.1 to 0.5 mass % of a fatty acid ester of a polyhydric alcohol.

5. A molded article obtained by molding the thermoplastic resin composition according to any one of claims 1 to 4.

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