Thermoplastic resin composition and molded article

Abstract

This thermoplastic resin composition contains a thermoplastic polyester resin (A), an aromatic polycarbonate resin (B), and a rubber-containing graft copolymer (C) as thermoplastic resin components. The content of the thermoplastic polyester resin (A) is 15-80 mass parts, the content of the aromatic polycarbonate resin (B) is 5-84 mass parts, and the content of the rubber-containing graft copolymer (C) is 1-15 mass parts in 100 mass parts of the thermoplastic resin components. The thermoplastic resin composition contains 4.5 mass% or less of a polymer component soluble in acetone in 100 mass% of the thermoplastic resin components. Also provided is a molded article produced by molding the thermoplastic resin composition.

Description

Thermoplastic resin composition and molded article

[0001] The present invention relates to a thermoplastic resin composition that is excellent in chemical resistance and impact resistance, and that exhibits ductile fracture properties, particularly when subjected to surface impact, and to a molded article thereof.

[0002] Conventionally, a coating resin composition containing a rubber-reinforced vinyl resin, a polyester resin, an ethylene-(meth)acrylic acid ester-carbon monoxide copolymer, and a polycarbonate resin has been proposed as a coating resin composition that can provide a coating appearance with an excellent balance of coatability, impact resistance, moldability, and chemical resistance (Patent Document 1).

[0003] Meanwhile, with the rise in environmental awareness in recent years, there has been a movement to eliminate painting processes in order to reduce carbon dioxide emissions and emissions of volatile organic compounds (VOCs) such as solvents. To meet this demand for unpainted products, it has become necessary to significantly improve the chemical resistance of the resin itself more than ever before. In particular, there has been an accelerating trend toward unpainted resin components for automotive interiors. To achieve unpainted products, it is necessary to solve the problem of resin deterioration caused by contact with hands that have chemicals such as sunscreen cream on them, resulting in the whitening of the surface of the resin components with use.

[0004] As a thermoplastic resin composition that can be used without coating, a thermoplastic resin composition containing a resin obtained by graft copolymerizing an ethylene-propylene rubber polymer with a monomer mixture mainly composed of an aromatic vinyl monomer and a vinyl cyanide monomer, a polyester block copolymer, an aromatic polycarbonate resin, and a linear saturated polyester resin has been proposed (Patent Document 2). However, this thermoplastic resin composition only achieves improvements in weather resistance, heat resistance, scratch resistance, and cold workability, and does not meet current market demands for chemical resistance and impact resistance.

[0005] JP 2018-024719 A JP 01-152148 A

[0006] An object of the present invention is to provide a thermoplastic resin composition which is excellent in chemical resistance and impact resistance, and which exhibits ductile fracture properties particularly when subjected to surface impact, and a molded article thereof.

[0007] As a result of extensive investigations aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by controlling the content of acetone-soluble polymer components in a thermoplastic resin containing a thermoplastic polyester resin (A), an aromatic polycarbonate resin (B), and a rubber-containing graft copolymer (C) in predetermined proportions as thermoplastic resin components to a predetermined value or less, and have thus completed the present invention.

[0008] [1] A thermoplastic resin composition comprising a thermoplastic polyester resin (A), an aromatic polycarbonate resin (B), and a rubber-containing graft copolymer (C) as thermoplastic resin components, wherein the content of the thermoplastic polyester resin (A) is 15 to 80 parts by mass, the content of the aromatic polycarbonate resin (B) is 5 to 84 parts by mass, and the content of the rubber-containing graft copolymer (C) is 1 to 15 parts by mass, per 100 parts by mass of the thermoplastic resin components, and the thermoplastic resin composition contains 4.5% by mass or less of an acetone-soluble polymer component per 100% by mass of the thermoplastic resin components.

[0009] [2] The thermoplastic resin composition according to [1], wherein the content of the rubber polymer in the thermoplastic resin composition is 0.5 to 10 mass% based on 100 mass% of the thermoplastic resin component.

[0010] [3] The thermoplastic resin composition according to [2], wherein the ratio of the content (mass%) of the rubber polymer to the content (mass%) of the acetone-soluble polymer component in the thermoplastic resin composition (mass ratio: rubber polymer / acetone-soluble polymer component) is 1 to 20.

[0011] [4] A molded article obtained by molding the thermoplastic resin composition according to any one of [1] to [3].

[0012] According to the present invention, it is possible to provide a thermoplastic resin composition that has excellent chemical resistance, and the resin does not deteriorate even when touched with hands that have chemicals such as sunscreen cream on them, and that also has excellent impact resistance, and that exhibits a ductile fracture morphology, particularly when subjected to a surface impact, and a molded article thereof.

[0013] The following describes in detail an embodiment of the present invention. The following description is an example (typical example) of an embodiment of the present invention, and the present invention is not limited to the contents thereof as long as it does not depart from the gist of the present invention.

[0014] [Thermoplastic Resin Composition] The thermoplastic resin composition of the present invention comprises, as thermoplastic resin components, a thermoplastic polyester resin (A) (hereinafter sometimes referred to as "component (A)"), an aromatic polycarbonate resin (B) (hereinafter sometimes referred to as "component (B)"), and a rubber-containing graft copolymer (C) (hereinafter sometimes referred to as "component (C)"), wherein, per 100 parts by mass of the thermoplastic resin components, the content of the thermoplastic polyester resin (A) is 15 to 80 parts by mass, the content of the aromatic polycarbonate resin (B) is 5 to 84 parts by mass, and the content of the rubber-containing graft copolymer (C) is 1 to 15 parts by mass, and the thermoplastic resin composition is characterized in that, per 100% by mass of the thermoplastic resin components, the composition contains 4.5% by mass or less of a polymer component soluble in acetone.

[0015] The thermoplastic resin components contained in the thermoplastic resin composition of the present invention are the thermoplastic polyester resin (A), the aromatic polycarbonate resin (B), the rubber-containing graft copolymer (C), and other resins (hereinafter simply referred to as "other resins") other than the thermoplastic polyester resin (A), the aromatic polycarbonate resin (B), and the rubber-containing graft copolymer (C) described below, which are contained as necessary. Therefore, "100 parts by mass of the thermoplastic resin component" means the total of 100 parts by mass of the thermoplastic polyester resin (A), the aromatic polycarbonate resin (B), the rubber-containing graft copolymer (C), and the other resins contained as necessary.

[0016] [Mechanism] By containing the thermoplastic polyester resin (A), aromatic polycarbonate resin (B), and rubber-containing graft copolymer (C) in the specific ratios specified in the present invention and by keeping the content of the acetone-soluble polymer component below the above upper limit, the composition exhibits excellent chemical resistance and impact resistance, and in particular, exhibits ductile fracture morphology upon surface impact. Although the details of the mechanism by which this occurs are not clear, it is believed to be as follows. By kneading the thermoplastic polyester resin (A) and the aromatic polycarbonate resin (B), a fine co-continuous structure of the thermoplastic polyester resin (A) and the aromatic polycarbonate resin (B) is formed, suppressing chemical degradation of the aromatic polycarbonate resin (B) phase. On the other hand, by kneading the thermoplastic polyester resin (A) and the aromatic polycarbonate resin (B), the crystallinity of the thermoplastic polyester resin (A) decreases, and in the absence of the rubber-containing graft copolymer (C), the reduced crystallinity impairs impact resistance. However, the coexistence of a predetermined amount of rubber-containing graft copolymer (C) improves the affinity between the rubber-containing graft copolymer (C) and the aromatic polycarbonate resin (B) through a transesterification reaction between the rubber-containing graft copolymer (C) and the aromatic polycarbonate resin (B). This improves impact resistance. Furthermore, when the acetone-soluble polymer component forms large domains in the thermoplastic polyester resin (A) / aromatic polycarbonate resin (B) cocontinuous structure, chemical resistance tends to decrease, and cracks occur at the interface between the acetone-soluble polymer component and the thermoplastic polyester resin (A), resulting in a decrease in impact resistance. However, by reducing the content of the acetone-soluble polymer component as described above, chemical resistance and impact resistance can be maintained. Furthermore, in addition to the impact absorption due to the rubber elasticity of the rubber-containing graft copolymer (C), energy is absorbed by peeling at the interface of the fine cocontinuous structure formed between the thermoplastic polyester resin (A) and the aromatic polycarbonate resin (B). It is believed that this energy absorption suppresses crack propagation and allows ductile fracture to occur upon surface impact.

[0017] [Thermoplastic polyester resin (A)] As the thermoplastic polyester resin (A), a polymer or copolymer obtained by a polycondensation reaction of a dicarboxylic acid (or an ester-forming derivative thereof) and a diol (or an ester-forming derivative thereof) as main components can be used.

[0018] Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,2'-biphenyldicarboxylic acid, 3,3'-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-diphenylisopropylidenedicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid, 2,5-anthracenedicarboxylic acid, 2,6-anthracenedicarboxylic acid, 4,4'-p-terphenylenedicarboxylic acid, and 2,5-pyridinedicarboxylic acid. Of these, terephthalic acid is preferred.

[0019] Two or more of these dicarboxylic acid components may be mixed and used. In addition, a small amount of one or more of aliphatic dicarboxylic acid components such as adipic acid, azelaic acid, dodecanedioic acid, and sebacic acid, and alicyclic dicarboxylic acid components such as cyclohexanedicarboxylic acid may be mixed and used together with these dicarboxylic acid components.

[0020] Examples of diol components include aliphatic diols such as ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, diethylene glycol, and triethylene glycol; alicyclic diols such as 1,4-cyclohexanedimethanol; and mixtures thereof. Of these, ethylene glycol, propylene glycol, and butylene glycol are preferred. A small amount of a long-chain diol having a molecular weight of 400 to 6,000, such as polyethylene glycol, poly-1,3-propylene glycol, or polytetramethylene glycol, may be used in combination.

[0021] The intrinsic viscosity (IV) of the thermoplastic polyester resin (A) is not particularly limited, but the lower limit may be determined from the viewpoint of mechanical strength and impact strength, and the upper limit from the viewpoint of chemical resistance. The intrinsic viscosity of the thermoplastic polyester resin (A) is preferably 0.70 to 2.00 dL / g, more preferably 0.80 to 1.50 dL / g, and particularly preferably 1.05 to 1.40 dL / g. When the intrinsic viscosity of the thermoplastic polyester resin is within the above range, excellent impact strength and good chemical resistance can be exhibited, and further, molded articles made from the thermoplastic resin composition of the present invention can exhibit excellent appearance characteristics and jet black color. Here, the intrinsic viscosity of the thermoplastic polyester resin (A) is a value measured at 30°C in a mixed solvent of tetrachloroethane and phenol in a 1:1 (mass ratio).

[0022] Preferred examples of these polymers or copolymers include aromatic polyester resins such as polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), and polyethylene-1,2-bis(phenoxy)ethane-4,4'-dicarboxylate, as well as copolymerized aromatic polyester resins such as polybutylene terephthalate / isophthalate and polybutylene terephthalate / decanedicarboxylate. Of these, PET and PBT are preferred from the viewpoints of ease of processability and mechanical properties, and PBT is particularly preferred from the viewpoint of chemical resistance.

[0023] These thermoplastic polyester resins (A) may be used as a mixture of two or more thermoplastic polyester resins, for example, a mixture of PET and PBT. However, a PBT-only system is preferred from the viewpoint of chemical resistance. If necessary, for example, multiple PBT resins with different fluidities may be mixed. Furthermore, recycled PBT resin and virgin PBT, which will be described later, may be mixed into the thermoplastic resin component.

[0024] <Content of Thermoplastic Polyester Resin (A)> In the thermoplastic resin composition of the present invention, the content of component (A) per 100 parts by mass of the total thermoplastic resin components is 15 to 80 parts by mass, preferably 20 to 76 parts by mass, more preferably 21 to 62 parts by mass, and even more preferably 23.5 to 55 parts by mass. When the content of component (A) is equal to or greater than the above-mentioned lower limit, chemical resistance is good. When the content of component (A) is equal to or less than the above-mentioned upper limit, impact resistance is good. When component (A) of a recycled resin described below is used as component (A), the content of component (A) also includes component (A) as the recycled resin.

[0025] [Aromatic Polycarbonate Resin (B)] The aromatic polycarbonate resin (B) is not particularly limited, but one having a viscosity-average molecular weight (Mv) of 10,000 to 100,000, particularly 15,000 to 45,000, and particularly 17,000 to 26,000 is preferably used. When the viscosity-average molecular weight (Mv) of the aromatic polycarbonate resin (B) is within the above range, the impact resistance and moldability of the resulting molded article are improved. Furthermore, molded articles made from the thermoplastic resin composition of the present invention can exhibit excellent appearance and jet black color. Here, the viscosity-average molecular weight (Mv) of the aromatic polycarbonate resin (B) is measured using an Ubbelohde viscometer in a solution using methylene chloride as a solvent, and calculated using the Schnell viscosity formula below: [η] = 1.23 × 10 －４ Mv ０．８３ (In the formula, η represents the intrinsic viscosity, and Mv represents the viscosity average molecular weight.)

[0026] Such aromatic polycarbonate resin (B) is typically produced by reacting a dihydric phenol with a carbonate precursor by a solution method or a melt method. The dihydric phenol used herein includes 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), but part or all of it may be replaced with another dihydric phenol. Examples of other dihydric phenols include bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, and bis(4-hydroxyphenyl)sulfone. Examples of carbonate precursors include carbonyl halides, carbonyl esters, and haloformates. Specific examples include phosgene, diphenyl carbonate, dihaloformates of dihydric phenols, and mixtures thereof.

[0027] In producing the aromatic polycarbonate resin (B), a suitable molecular weight modifier, branching agent, catalyst for accelerating the reaction, etc. may also be used.

[0028] In the present invention, two or more aromatic polycarbonate resins produced in this manner may be mixed and used. For example, two or more aromatic polycarbonate resins having different viscosity average molecular weights (Mv) may be mixed and used after adjusting to the above-mentioned suitable viscosity average molecular weight (Mv). In addition, a recycled aromatic polycarbonate resin and a virgin aromatic polycarbonate resin, which will be described later, may be mixed into the thermoplastic resin component.

[0029] <Content of Aromatic Polycarbonate Resin (B)> In the thermoplastic resin composition of the present invention, the content of component (B) per 100 parts by mass of the thermoplastic resin component is 5 to 84 parts by mass, preferably 10 to 78.5 parts by mass, more preferably 25 to 77 parts by mass, and even more preferably 35 to 74 parts by mass. When the content of component (B) is equal to or greater than the above-mentioned lower limit, the impact resistance is good. When the content of component (B) is equal to or less than the above-mentioned upper limit, the chemical resistance is good. When component (B) of a recycled resin described below is used as component (B), the content of component (B) also includes component (B) as the recycled resin.

[0030] [Rubber-Containing Graft Copolymer (C)] The rubber-containing graft copolymer (C) is obtained by graft polymerizing a vinyl-based monomer mixture (c2) in the presence of a rubbery polymer (c1).

[0031] <Rubber Polymer (c1)> The rubber polymer (c1) (hereinafter, sometimes referred to as "component (c1)") constituting the rubber-containing graft copolymer (C) is not particularly limited, and examples thereof include diene rubber, acrylic rubber, and ethylene rubber. Specific examples include polybutadiene, poly(butadiene-styrene), poly(butadiene-acrylonitrile), polyisoprene, poly(butadiene-butyl acrylate), poly(butadiene-methyl acrylate), polybutyl acrylate, poly(butadiene-methyl methacrylate), poly(butadiene-ethyl acrylate), ethylene-propylene rubber, ethylene-propylene-diene rubber, poly(ethylene-isobutylene), poly(ethylene-methyl acrylate), and poly(ethylene-ethyl acrylate). These rubber polymers are used alone or in a mixture of two or more. Among these, polybutadiene, poly(butadiene-styrene), poly(butadiene-acrylonitrile), poly(butadiene-butyl acrylate), and poly(butadiene-methyl acrylate) are preferred, and polybutadiene and poly(butadiene-styrene) are more preferably used because they provide the thermoplastic resin composition of the present invention with excellent impact resistance.

[0032] From the viewpoint of the impact resistance, fluidity, and jet blackness of the resulting thermoplastic resin composition, the volume average particle diameter of the rubbery polymer (c1) is preferably 50 to 500 nm, more preferably 150 to 400 nm, even more preferably 250 to 340 nm, and most preferably 270 to 330 nm. Here, the volume average particle diameter of the rubbery polymer (c1) is a value measured by the method described in the Examples section below. The average particle diameter of the rubbery polymer may be measured before use in the thermoplastic resin composition, or can be confirmed by image analysis using electron microscope photographs of the thermoplastic resin composition.

[0033] <Vinyl Monomer Mixture (c2)> The vinyl monomer mixture (c2) (hereinafter, may be referred to as "component (c2)") is preferably a vinyl monomer mixture containing at least an aromatic vinyl monomer and a vinyl cyanide monomer.

[0034] Examples of aromatic vinyl monomers include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, t-butylstyrene, o-ethylstyrene, o-chlorostyrene, and o,p-dichlorostyrene. These may be used alone or in combination of two or more.

[0035] Examples of vinyl cyanide monomers include acrylonitrile, methacrylonitrile, and ethacrylonitrile, with acrylonitrile being particularly preferred. The vinyl cyanide monomers may be used alone or in combination of two or more.

[0036] The ratio of the aromatic vinyl monomer to the vinyl cyanide monomer in 100% by mass of the vinyl monomer mixture (c2) is preferably aromatic vinyl monomer / vinyl cyanide monomer=60 to 80% by mass / 20 to 40% by mass, more preferably 65 to 80% by mass / 20 to 35% by mass, and even more preferably 67 to 76% by mass / 24 to 33% by mass, from the viewpoints of moldability of the resulting thermoplastic resin composition and appearance of the molded product.

[0037] In addition to the aromatic vinyl monomer and the vinyl cyanide monomer, the vinyl monomer mixture (c2) may contain 0 to 30% by mass of other vinyl monomers copolymerizable therewith. Examples of other vinyl monomers copolymerizable therewith include, but are not limited to, one or more of: unsaturated carboxylic acid ester monomers such as methyl (meth)acrylate; maleimide monomers such as N-methylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide; unsaturated dicarboxylic acids such as maleic acid; unsaturated dicarboxylic anhydrides such as maleic anhydride; and unsaturated amides such as acrylamide. Among these, methyl (meth)acrylate, N-phenylmaleimide, and maleic anhydride are preferred. The term "(meth)acrylic acid" refers to either or both of acrylic acid and methacrylic acid.

[0038] <Ratio of Rubber Polymer (c1) to Vinyl Monomer Mixture (c2)> The rubber-containing graft copolymer (C) is preferably obtained by graft polymerizing 20 to 70 mass % of a vinyl monomer mixture (c2) in the presence of 30 to 80 mass % of a rubber polymer (c1), provided that the total of the rubber polymer (c1) and the vinyl monomer mixture (c2) is 100 mass %.

[0039] If the rubber polymer (c1) is less than 30% by mass and the vinyl monomer mixture (c2) is more than 70% by mass, the resulting thermoplastic resin composition tends to have poor impact resistance. If the rubber polymer (c1) is more than 80% by mass and the vinyl monomer mixture (c2) is less than 20% by mass, the impact resistance and moldability tend to be reduced. The proportion of the rubber polymer (c1) is more preferably 35 to 70% by mass, even more preferably 40 to 65% by mass, and the proportion of the vinyl monomer mixture (c2) is more preferably 30 to 65% by mass, even more preferably 35 to 60% by mass.

[0040] The rubber-containing graft copolymer (C) does not necessarily have to be entirely grafted with the vinyl-based monomer mixture (c2), and is usually obtained as a mixture with a non-grafted copolymer. This mixture is essentially a composition, but in the present invention, it is included in the rubber-containing graft copolymer (C). This non-grafted copolymer becomes a polymer component extracted as an acetone-soluble matter.

[0041] <Graft Ratio> The graft ratio of the rubber-containing graft copolymer (C) is not limited, but from the viewpoint of impact resistance, it is preferably 10 to 150% by mass, more preferably 20 to 120% by mass, and even more preferably 30 to 90% by mass. The graft ratio of the rubber-containing graft copolymer (C) is measured by the method described in the Examples section below.

[0042] <Molecular Weight of Ungrafted Copolymer> The composition of the ungrafted copolymer in the rubber-containing graft copolymer (C) falls within the range of the blending ratio of the monomer components. The mass average molecular weight (Mw) of the ungrafted copolymer is preferably 20,000 to 400,000, more preferably 30,000 to 200,000, and even more preferably 40,000 to 100,000. The molecular weight distribution (Mw / Mn) is preferably 2.0 to 4.0, more preferably 2.5 to 3.5, and even more preferably 2.7 to 3.2. When the mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) are within the above ranges, the resulting thermoplastic resin composition tends to have better fluidity and impact resistance.

[0043] The mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the ungrafted copolymer can be measured as polystyrene equivalent values ​​by GPC, as described in detail in the Examples section below.

[0044] <Graft polymerization method> There is no particular limitation on the method of graft polymerization of the rubber-containing graft copolymer (C). The rubber-containing graft copolymer (C) can be produced by any known method such as emulsion polymerization, suspension polymerization, continuous bulk polymerization, or continuous solution polymerization. In particular, emulsion polymerization is preferred because it is easy to adjust the rubber content of the rubber-containing graft copolymer (C), produces extremely little oligomers derived from the grafted monomers, does not use organic solvents such as toluene or benzene, and therefore does not leave any residue. It is also easy to handle (e.g., the rubber content can be easily adjusted), and product safety is also a factor.

[0045] Here, when a polymer in block or pellet form, such as an ethylene-propylene rubber polymer, is used as the rubber polymer, emulsion polymerization is difficult. For this reason, it is common to employ a continuous solution polymerization method in which the polymer is dissolved in a solvent. Therefore, in this case, a method in which a rubber polymer dispersion is obtained by a "mechanical emulsification method" and then the rubber-containing graft copolymer (C) is produced by emulsion polymerization is particularly preferred. Here, the "mechanical emulsification method" refers to a method in which a polymer in block or pellet form produced by a separate process is subjected to mechanical shear force in the presence of an emulsifier and a waxy polymer, thereby finely dispersing and stabilizing the polymer in water. In this way, the polymer finely dispersed in water obtained by the mechanical emulsification method can be used as the rubber polymer (c1) and produced as the rubber-containing graft copolymer (C) by emulsion polymerization.

[0046] For polymers dispersed by mechanical emulsification, it is possible to adjust the degree of crosslinking of the polymer by adding a crosslinking agent and a polymerization initiator as necessary and then subjecting the mixture to heat treatment.

[0047] In the process of producing the rubber-containing graft copolymer (C) by emulsion polymerization, examples of the coagulant used for recovering the copolymer from the emulsion include metal salts such as calcium chloride, calcium acetate, and aluminum sulfate, and inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid. Among these, a graft copolymer recovered using an inorganic acid is preferred. This provides excellent impact resistance and ductile fracture properties, as well as excellent chemical resistance, which reduces the effects of chemical degradation and discoloration, allowing the performance of the final part to be maintained for a particularly long period of time.

[0048] The coagulant is selected depending on the emulsifier. When a carboxylic acid soap such as a fatty acid soap or a rosin acid soap is used as the emulsifier, recovery can be achieved using either a metal salt or an inorganic acid, and it is particularly preferable to coagulate and recover using an inorganic acid, particularly sulfuric acid. However, if the product is coagulated with sulfuric acid and then neutralized with sodium hydroxide or the like, it is difficult to obtain the performance required for the final part, so simply rinsing with water is sufficient.

[0049] The amount of coagulant added is usually 1 to 5 parts by mass, preferably 2 to 4 parts by mass, per 100 parts by mass of the solid content of the polymer latex. The coagulant is usually used as an aqueous solution diluted to a coagulant concentration of 1 to 20% by mass. The temperature during coagulation can be set as appropriate, but is usually in the range of 50 to 95°C.

[0050] The rubber-containing graft copolymer (C) may be a blend of multiple rubber-containing graft copolymers produced separately, such as those containing different types of rubber polymers, different rubber particle sizes, or different compositions of graft copolymerization components, depending on the purpose.

[0051] <Content of Rubber-Containing Graft Copolymer (C)> In the thermoplastic resin composition of the present invention, the content of component (C) per 100 parts by mass of the thermoplastic resin component is 1 to 15 parts by mass, preferably 1.5 to 14 parts by mass, more preferably 2 to 13 parts by mass, and even more preferably 2.5 to 10 parts by mass. When the content of component (C) is equal to or greater than the above-mentioned lower limit, the impact resistance is good. When the content of component (C) is equal to or less than the above-mentioned upper limit, the chemical resistance is good. When component (C) of a recycled resin described below is used as component (C), the content of component (C) also includes component (C) as the recycled resin.

[0052] [Other Resins] Examples of other resins that can be used in the present invention include one or more of polyvinyl chloride resin, polystyrene resin, AS-based resin, polymethyl methacrylate resin, methyl methacrylate-styrene copolymer resin, methyl methacrylate-N-phenylmaleimide copolymer resin, polyamide resin, polyphenylene ether-polystyrene composite resin, polypropylene resin, olefin-based resin such as polyethylene resin, styrene-maleic anhydride copolymer resin, polyphenylene ether-based resin, polyoxymethylene-based resin, polysulfone-based resin, polyacrylate-based resin, polyethylene-based resin, thermoplastic polyurethane, polylactic acid, and plant-derived bioplastics.

[0053] <Content of Other Resins> When the thermoplastic resin composition of the present invention contains other resins as thermoplastic resin components, the content of the other resins per 100 parts by mass of the thermoplastic resin component is preferably 0 to 30 parts by mass, more preferably 0 to 20 parts by mass, and even more preferably 0 to 10 parts by mass. By containing the other resins, it becomes possible to develop the properties of the other resins. On the other hand, by keeping the content of the other resins at or below the above upper limit, it is possible to fully exhibit the effects of using components (A) to (C) in the specified ratio, such as chemical resistance and impact resistance.

[0054] [Recycled Resin] The thermoplastic resin composition of the present invention can contain recycled resins, such as recycled thermoplastic polyester resins, recycled aromatic polycarbonate resins, recycled rubber-containing graft copolymers, and other recycled resins, as components (A) to (C) and other resins. The recycled resins can be post-consumer (resins recovered from the market, etc.) or pre-consumer (resin waste generated during the manufacturing or molding process), and are not particularly limited.

[0055] [Acetone-soluble polymer component and rubbery polymer in thermoplastic resin composition] <Content of acetone-soluble polymer component in thermoplastic resin composition> The content of the acetone-soluble polymer component in 100% by mass of the thermoplastic resin component in the thermoplastic resin composition of the present invention is 4.5% by mass or less, preferably 4% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less. On the other hand, there is no particular restriction on the lower limit of the content of the acetone-soluble polymer component, and it may be 0% by mass, i.e., it may not be contained. However, since it is difficult to achieve 0% by mass in reality, it is more than 0% by mass, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more. By having the content of the acetone-soluble polymer component within the above range, a thermoplastic resin composition having excellent chemical resistance and impact resistance is obtained.

[0056] When the thermoplastic resin composition of the present invention contains the aforementioned other resins or recycled resins, the thermoplastic resin component of the present invention corresponds to the sum of components (A) to (C) including the recycled resin and the other resins, and therefore the content of the acetone-soluble polymer component in 100% by mass of the thermoplastic resin component including the other resins and / or recycled resins will satisfy the above range. Therefore, particularly in the case of a thermoplastic resin composition containing recycled resins, it is preferable to confirm the amount of the acetone-soluble polymer component at the recycled raw material stage. In this way, by confirming the amount of the acetone-soluble polymer component in the raw material, wasteful production can be avoided and environmentally friendly production of thermoplastic resin compositions becomes possible.

[0057] <Confirmation of the Amount of Acetone-Soluble Polymer Component in Thermoplastic Resin Composition> The amount of the acetone-soluble polymer component in the thermoplastic resin composition can be determined mainly by the following two methods.

[0058] (Method 1) A thermoplastic resin composition (e.g., about 3 g) is weighed and immersed in a solvent such as hexafluoroisopropanol to separate the soluble and insoluble components. The soluble component (A) contains components (A) and (B) and the acetone-soluble component of component (C), i.e., the ungrafted copolymer (described above). (The grafted polymer component of component (C) simply swells and becomes insoluble.) Next, the soluble component (A) is dropped into a solvent such as chloroform to precipitate (precipitate) component (A). Component (A) can then be separated by filtering this solvent. This chloroform solvent (B) contains component (B) and the acetone-soluble component of component (C) as soluble components. Furthermore, component (B) is precipitated (precipitated) by dropping this chloroform solvent (B) into an acetone solvent. Component (B) can then be separated by filtering. This acetone solvent (c) is dropped into methanol to precipitate the polymer component, and the solid content is then filtered and extracted, dried in a vacuum dryer for 24 hours, and its mass is weighed. This allows the mass of the acetone-soluble polymer component in the thermoplastic resin component to be determined.

[0059] (Method 2) The acetone-soluble content of each component constituting the thermoplastic resin composition is measured to confirm the acetone-soluble polymer component in the thermoplastic resin. For example, the rubber-containing graft copolymer (C) is described as follows. The rubber-containing graft copolymer (e.g., approximately 2 g) is weighed and placed in acetone to separate the acetone-insoluble and acetone-soluble components. The acetone-soluble component is dropped into methanol to precipitate the polymer component. The solid component is then filtered and removed, dried in a vacuum dryer for 24 hours, and its mass is weighed. This allows the mass of the acetone-soluble polymer component in the rubber-containing graft copolymer to be determined. When the graft ratio of the rubber-containing graft copolymer is determined, the mass of the acetone-soluble polymer component in the rubber-containing graft copolymer can be determined from that value.

[0060] In either method, the content of the acetone-soluble polymer component in 100 mass% of the thermoplastic resin component can be determined by dividing the determined amount of the acetone-soluble polymer component by the total amount of the thermoplastic resin component in the thermoplastic resin composition and calculating the percentage.

[0061] <Weight Average Molecular Weight (Mw) of Acetone-Soluble Polymer Component> The weight average molecular weight of the acetone-soluble polymer component obtained by Methods 1 and 2 can also be measured. The weight average molecular weight (Mw) of this acetone-soluble polymer component is preferably 20,000 to 400,000, more preferably 30,000 to 200,000, and even more preferably 40,000 to 100,000. The molecular weight distribution (Mw / Mn) is preferably 2.0 to 4.0, more preferably 2.5 to 3.5, and even more preferably 2.7 to 3.2. When the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the acetone-soluble polymer component are within the above ranges, the resulting thermoplastic resin composition tends to have better impact resistance and chemical resistance. Here, the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) can be measured as polystyrene-equivalent values ​​by GPC. Details are as described in the Examples section below.

[0062] <Rubber polymer content in thermoplastic resin composition> The content of the rubber polymer in 100% by mass of the thermoplastic resin component in the thermoplastic resin composition of the present invention corresponds to, for example, the content of the rubber polymer (c1) in the rubber-containing graft copolymer (C) described above, and is preferably 0.5% by mass or more, more preferably 0.6% by mass or more, even more preferably 1% by mass or more, and particularly preferably 1.5% by mass or more. On the other hand, the content of the rubber polymer in 100% by mass of the thermoplastic resin component is preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 5% by mass or more, and particularly preferably 3.5% by mass or less. If the content of the rubber polymer is above the above lower limit, the impact resistance is further improved, and the molded article exhibits a ductile fracture mode upon surface impact, which is also suitable from a safety standpoint. If the content of the rubber polymer is below the above upper limit, the jet blackness is high, the appearance of the resulting molded article is good, and the heat resistance is also good.

[0063] As with the acetone-soluble polymer component described above, when the thermoplastic resin composition of the present invention contains the other resins or recycled resins described above, the thermoplastic resin component according to the present invention corresponds to the total of components (A) to (C) including the recycled resin and the other resins, and therefore when a recycled resin containing a rubber polymer is used, it is preferable to confirm the content of the rubber polymer in advance at the raw material stage.

[0064] <Mass Ratio of Rubbery Polymer to Acetone-Soluble Polymer Component in Thermoplastic Resin Composition> The ratio of the content (mass%) of the rubbery polymer to the content (mass%) of the acetone-soluble polymer component in the thermoplastic resin composition of the present invention (mass ratio: rubbery polymer / acetone-soluble polymer component) is preferably 1 or more. This allows the thermoplastic resin composition to exhibit significant chemical resistance and impact resistance. From this viewpoint, this ratio is more preferably 2 or more, and even more preferably 4 or more. There is no particular restriction on the upper limit of this ratio, but it is preferably 20 or less, more preferably 15 or less, even more preferably 13 or less, and particularly preferably 12 or less. When the mass ratio of rubbery polymer / acetone-soluble polymer component is within the above range, the thermoplastic resin composition has even more excellent chemical resistance and impact resistance.

[0065] [Additives] The thermoplastic resin composition of the present invention may contain, if necessary, additives that are typically incorporated into thermoplastic resin compositions. Examples of additives include colorants such as pigments and dyes, fillers (carbon black, silica, etc.), halogen-based flame retardants, phosphorus-based flame retardants, stabilizers, reinforcing agents, processing aids, heat resistance agents, antioxidants, weather resistance agents, release agents, plasticizers, and antistatic agents.

[0066] [Method for Producing Thermoplastic Resin Composition] The thermoplastic resin composition of the present invention is produced by mixing and dispersing components (A) to (C) and, if necessary, other thermoplastic resins and additives using a V-type blender, a Henschel mixer, or the like, melt-kneading the resulting mixture using a kneading machine such as an extruder, a Banbury mixer, a pressure kneader, or a roll, and then cutting and pelletizing the mixture using a pelletizer, or the like.

[0067] [Molded Article] The molded article of the present invention is obtained by molding the thermoplastic resin composition of the present invention and has excellent chemical resistance and impact resistance. In particular, it exhibits ductile fracture morphology upon surface impact, and therefore is also excellent in safety. Furthermore, the thermoplastic resin composition of the present invention and the molded article of the present invention can be made excellent in mechanical properties such as rigidity and heat resistance by adjusting the other thermoplastic resins used in combination and their blending amounts. Examples of methods for molding the thermoplastic resin composition of the present invention include injection molding, injection compression molding, extrusion, blow molding, vacuum molding, pressure molding, calendar molding, and inflation molding. Among these, injection molding is preferred because it is easy to mass-produce and can produce molded articles with high dimensional accuracy.

[0068] [Applications and Potential Uses] Specific applications of the molded article of the present invention include many applications, such as automobiles, electrical, electronic, and mechanical parts, industrial products such as flushing parts, and sports and leisure goods. More specifically, automotive applications include radiator grilles, door handles, emblems, lamp housings, various moldings and garnishes, and wheel caps. Electrical, electronic, and mechanical part applications include various switch buttons, arm handles, refrigerator door handles, mobile phone parts, and various housings. Flushing part applications include various flushing handle shower heads and spouts. Sports and leisure goods applications include pachinko machines, slot machine machines, watch frames, decorative buttons, and cosmetic caps. Among these, the molded article is preferably used for automotive exterior and interior parts and flushing parts.

[0069] The thermoplastic resin composition of the present invention is excellent in moldability and various physical properties, and is also suitable for secondary processing. The thermoplastic resin composition of the present invention is a thermoplastic resin composition particularly designed for unpainted applications, but molded articles made of the thermoplastic resin composition of the present invention may be subjected to secondary processing for decoration, such as plating, painting, or silk printing, as necessary.

[0070] To explain the present invention more specifically, examples and comparative examples will be given below. The following examples do not limit the present invention. Unless otherwise specified, "%" represents mass % and "parts" represents mass parts. In some places, acrylonitrile is abbreviated as AN and styrene is abbreviated as ST.

[0071] In the following, the volume average particle diameter of the rubber polymer (c1) was measured by the following (1). The graft ratio of the rubber-containing graft copolymer (C) was measured by the following (2). The mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the acetone-soluble polymer component of the rubber-containing graft copolymer (C) were measured by the following (3).

[0072] (1) Volume average particle diameter The volume average particle diameter in the latex of the rubber polymer (c1) was measured at room temperature using a "Microtrac UPA150" (trade name) manufactured by Honeywell Corporation. The unit is nm. It is known that there is no substantial difference between the particle diameter of the latex of the rubber polymer (c1) and the rubber particle diameter of the rubber polymer (c1) in the resin composition using the same, and the former corresponds to the latter.

[0073] (2) Graft Ratio The graft ratio of the rubber-containing graft copolymer (C) is calculated by the following formula: Graft Ratio (mass%) = {[(n) - (m) x L] / [(m) x L]} x 100 In the above formula, n is the mass n (g) of the acetone-insoluble fraction obtained by adding approximately 1 g (weighed: m (g)) of the rubber-containing graft copolymer (C) to 20 mL of acetone, shaking the mixture at 25°C for 2 hours using a shaker, and then centrifuging the mixture at 5°C for 60 minutes using a centrifuge (rotation speed: 23,000 rpm) to separate the acetone-insoluble and acetone-soluble fractions. L is the mass (g) of the rubbery polymer (c1) contained in the rubber-containing graft copolymer (C). The mass of this rubbery polymer (c1) can be determined by a method of calculation from the polymerization recipe and polymerization conversion rate, a method of determining it using infrared absorption spectroscopy, or the like.

[0074] (3) 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 in polystyrene equivalent using GPC (GPC: Waters "GPC / V2000", column: Showa Denko K.K. "Shodex AT-G+AT-806MS"), using o-dichlorobenzene (145 ° C) as a solvent. The sample for measuring the acetone-soluble polymer component was prepared by dropping the acetone-soluble component from the above-mentioned graft ratio measurement into methanol to precipitate the polymer component, and then filtering and extracting the solid, which was then dried in a vacuum dryer for 24 hours and used for the GPC measurement. In the GPC measurement of AS resin as another resin, the resin was dissolved in acetone, and then the polymer component was precipitated in methanol, and dried in a vacuum dryer for 24 hours, and each of these was used for the GPC measurement.

[0075] [Thermoplastic polyester resin (A)] The following commercially available products were used as the thermoplastic polyester resin (A): Polybutylene terephthalate resin (A-1) Polybutylene terephthalate "DURANEX 2002" (intrinsic viscosity (IV) = 1.02 dL / g) manufactured by Polyplastics Co., Ltd. Polybutylene terephthalate resin (A-2) Polybutylene terephthalate "NovaDuran 5020" (intrinsic viscosity (IV) = 1.20 dL / g) manufactured by Mitsubishi Chemical Corporation

[0076] [Aromatic Polycarbonate Resin (B)] The following commercially available products were used as the aromatic polycarbonate resin (B): Aromatic polycarbonate resin (B-1) "S3000" manufactured by Mitsubishi Engineering-Plastics Corporation (viscosity average molecular weight (Mv) = 22,000) Aromatic polycarbonate resin (B-2) "E2000" manufactured by Mitsubishi Engineering-Plastics Corporation (viscosity average molecular weight (Mv) = 28,000)

[0077] [Rubber-Containing Graft Copolymer (C)] <Synthesis Example 1: Production of Rubber-Containing Graft Copolymer (C-1)> 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 (solids content equivalent) of polybutadiene (BR) latex having a volume average particle size of 320 nm as a rubber polymer (c1-1), and the temperature inside the reactor was raised to 65° C. with stirring. Polymerization was initiated when the internal temperature reached 65° C., and 30 parts of styrene (ST) and 10 parts of acrylonitrile (AN) were used as component (c2-1), and this and 0.20 parts of a t-dodecyl mercaptan mixture as a chain transfer agent were continuously added over 5 hours. Simultaneously, an aqueous solution of polymerization initiators, cumene hydroperoxide (0.18 parts) and disproportionated rosin acid sodium salt (0.35 parts), was continuously added over 7 hours to complete the reaction. To the resulting latex, 1 part of 2,2'-methylenebis(4-methyl-6-t-butylphenol) was added per 100 parts of latex solids. Subsequently, the latex was coagulated at 80°C using 5% sulfuric acid to give a ratio of 2 parts of coagulant per 100 parts of latex solids. The mixture was then washed, filtered, and dried to obtain a powdery rubber-containing graft copolymer (C-1). The rubber (component (c1-1)) content of this rubber-containing graft copolymer (C-1) was 59.8%, and the graft ratio was 58%. The mass-average molecular weight (Mw) of the acetone-soluble polymer component was 56,000, and the molecular weight distribution (Mw / Mn) was 2.8.

[0078] Synthesis Example 2: Production of Rubber-Containing Graft Copolymer (C-2)> 100 parts of ethylene-propylene copolymer, 20 parts of maleic anhydride-modified polyethylene (Mitsui Chemicals, Inc., "Mitsui Hiwax 2203A", mass average molecular weight: 2,700, acid value: 30 mg / g) as an acid-modified olefin polymer, and 5 parts of tallow fatty acid potassium (a mixture of potassium oleate, potassium stearate, and potassium palmitate) as an anionic emulsifier were mixed. This mixture was fed at 4 kg / Hr from the hopper of a twin-screw extruder (Ikegai Corporation, "PCM30", L / D = 40), and heated to 220 ° C., melt-kneaded, and extruded while continuously feeding an aqueous solution of 0.5 parts potassium hydroxide and 2.4 parts ion-exchanged water from a feed port provided in the vent of the twin-screw extruder. The molten mixture was continuously fed to a cooling device attached to the tip of the twin-screw extruder and cooled to 90 ° C. The solids discharged from the tip of the twin-screw extruder were then poured into warm water at 80°C and continuously dispersed, followed by dilution to a solids concentration of approximately 40% by mass, yielding an aqueous olefin resin dispersion containing an ethylene-propylene copolymer (c1-2). 60 parts of this aqueous olefin resin dispersion (solids content) was placed in a stainless steel polymerization vessel equipped with a stirrer, and ion-exchanged water was added to the aqueous olefin resin dispersion so that the solids concentration was 30%. Then, 0.006 parts of ferrous sulfate, 0.3 parts of sodium pyrophosphate, 0.35 parts of fructose, and 1.0 part of tallow fatty acid potassium (a mixture of potassium oleate, potassium stearate, and potassium palmitate) were added, and the temperature was raised to 80°C. Using 30 parts of styrene (ST) and 10 parts of acrylonitrile (AN) as component (c2-2), this and 1.0 part of cumene hydroperoxide were continuously added for 150 minutes, and emulsion polymerization was carried out while maintaining the polymerization temperature at 80°C, yielding an aqueous dispersion containing a rubber-modified graft polymer. An antioxidant was added to the aqueous dispersion containing the rubber-modified graft polymer, and the solids were precipitated with sulfuric acid. After dehydration, washing, and drying, a powdery rubber-containing graft copolymer (C-2) was obtained. The rubber (component (c1-2), volume average particle diameter 375 nm) content of this rubber-containing graft copolymer (C-2) was 59.9%, and the graft ratio was 42%.The mass average molecular weight (Mw) of the acetone-soluble polymer component was 47,000, and the molecular weight distribution (Mw / Mn) was 2.4.

[0079] Synthesis Example 3: Production of Rubber-Containing Graft Copolymer (C-3) 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 50 parts (solids content equivalent) of a polybutadiene-styrene (SBR) latex having a volume average particle size of 310 nm as a rubber polymer (c1-3), and the temperature inside the reactor was raised to 65° C. with stirring. Polymerization was initiated when the internal temperature reached 65° C., and 35.5 parts of styrene (ST) and 14.5 parts of acrylonitrile (AN) were used as components (c2-3), and this and 0.20 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 disproportionated rosin acid sodium salt (0.7 parts), which serve as polymerization initiators, was continuously added over 7 hours to complete the reaction. To the obtained latex, 1 part of 2,2'-methylenebis(4-methyl-6-t-butylphenol) was added per 100 parts of the latex solids, and the procedure was repeated in the same manner as in Synthesis Example 1 to obtain a powdery rubber-containing graft copolymer (C-3). The rubber (component (c1-3)) content of this rubber-containing graft copolymer (C-3) was 49.8%, and the graft ratio was 30%. The mass average molecular weight (Mw) of the acetone-soluble polymer component was 67,000, and the molecular weight distribution (Mw / Mn) was 2.5.

[0080] Synthesis Example 4: Production of Rubber-Containing Graft Copolymer (C-4) 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 40 parts (solids content equivalent) of polybutadiene (BR) latex having a volume average particle size of 290 nm as the rubber polymer (c1-4), and the temperature inside the reactor was raised to 65°C with stirring. Polymerization was initiated when the internal temperature reached 65°C. Using 45 parts of styrene (ST) and 15 parts of acrylonitrile (AN) as component (c2-4), this and 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 disproportionated rosin acid sodium salt (0.7 parts), which served as a polymerization initiator, was continuously added over 7 hours to complete the reaction. To the obtained latex, 1 part of 2,2'-methylenebis(4-methyl-6-t-butylphenol) was added per 100 parts of latex solids, followed by salting out with 5% calcium chloride to give a ratio of 2 parts of coagulant per 100 parts of latex solids, followed by washing, filtration, and drying to obtain a powdery rubber-containing graft copolymer (C-4). The rubber (component (c1-4)) content of this rubber-containing graft copolymer (C-4) was 40.3%, and the graft ratio was 33%. The mass average molecular weight (Mw) of the acetone-soluble polymer component was 74,000, and the molecular weight distribution (Mw / Mn) was 2.3.

[0081] [Other Resins: AS-Based Resins] <Synthesis Example 5: Production of AS-Based Resin> 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 azoisobutylnitrile, 0.62 parts of t-dodecyl mercaptan, 23 parts of acrylonitrile, and 77 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 to obtain an AS-based resin (referred to as "AS" in Table 1) with an acrylonitrile / styrene ratio of 23 / 77. The acetone-soluble vinyl cyanide monomer content of the resulting AS-based resin was 23.1%, the mass-average molecular weight (Mw) was 154,000, and the molecular weight distribution (Mw / Mn) was 2.1.

[0082] [Examples 1 to 16, Comparative Examples 1 to 5] Components (A), (B), and (C) shown in Table 1 were mixed with other resins in the blending ratios (parts) shown in Table 1, and further mixed with 0.1 parts of ADEKA Corporation's ADK STAB "A-60 (trade name)" (tetrakis [methylene-3- (3',5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane) and 0.5 parts of carbon black as a black colorant. The mixture was melt-kneaded in a vacuum-vented twin-screw extruder (manufactured by Ikegai Corporation "PCM30") with a screw diameter of 30 mm at a cylinder temperature of 200 to 260 ° C. and a vacuum of 93.325 kPa. The mixture was taken up as a strand and pelletized using a pelletizer (manufactured by Soken Co., Ltd. "SH-type pelletizer") to obtain a thermoplastic resin composition. The following tests were performed using each thermoplastic resin composition, and the results are shown in Table 1.

[0083] [Preparation of Evaluation Test Pieces and Test Methods] <Preparation of Test Piece (A)> Using an injection molding machine (Shibaura Machine Co., Ltd., product name "IS55FP-1.5A"), a pellet-shaped thermoplastic resin composition was injection molded under conditions of a cylinder temperature of 220 to 250°C and a mold temperature of 60°C to obtain a test piece (A) measuring 80 mm in length, 10 mm in width, and 4 mm in thickness. The test piece (A) was used for measuring Charpy impact strength and deflection temperature under load.

[0084] <Evaluation of Impact Resistance: Measurement of Charpy Impact Strength> A Charpy impact test (notched) was performed on the test piece (A) at 23°C in accordance with ISO 179 standard, and the Charpy impact strength C-IMP (kJ / m ２ The higher the value, the better the impact resistance.

[0085] <Evaluation of Heat Resistance> The deflection temperature under load (HDT) (°C) of the test piece (a) was measured in accordance with ISO test method 75 using a flatwise method at 1.83 MPa and 4 mm.

[0086] <Preparation of Test Piece (B)> The pellet-like thermoplastic resin composition was injection molded using a 75-ton injection molding machine ("JSW-75EIIP" manufactured by The Japan Steel Works, Ltd.) under conditions of a cylinder temperature of 250°C, a mold temperature of 60°C, and an injection speed of 30 mm / sec, to obtain a test piece (B) measuring 55 mm in length, 80 mm in width, and 2.5 mm in thickness. The test piece (B) was used for measuring chemical resistance, surface impact resistance, and molded appearance.

[0087] <Evaluation of Chemical Resistance (Gloss Retention Rate)> A sunscreen cream (Neutrogena's "SPF45 Ultra Shea Dry Touch Oxybenzene Free") was applied to the test piece (B), kept at 80°C for 4 hours, and then wiped off with a cloth. Thereafter, using a "Digital Variable Gloss Meter UGV-5D" manufactured by Suga Test Instruments Co., Ltd., the reflectance (%) of the surface of the test piece (B) was measured at an incident angle of 60° and a reflection angle of 60° in accordance with JIS K7105. The gloss retention rate (%) was calculated for the gloss after the test (after wiping) relative to the gloss before the test (before application). The higher the gloss retention rate, the better the chemical resistance.

[0088] <Evaluation of surface impact resistance> Test piece (B) was punched and measured using a high-speed puncture impact tester "Hydroshot HITS-P10" manufactured by Shimadzu Corporation, with a punch diameter of 12.7 mm, a sample holder hole diameter of 43.0 mm, a punching test speed of 6.7 m / sec, and a temperature of 23°C. The fracture morphology of the test piece was observed and evaluated according to the following criteria. A score of ○ to △ was considered to be pass. ○: Ductile fracture. △: Partial cracking, but can be said to be ductile fracture. ×: Brittle fracture.

[0089] <Evaluation of Molded Appearance (Jet Blackness)> The lightness L* of test piece (B) was measured by the SCE method using a spectrophotometer ("CM-3500d" manufactured by Konica Minolta Optips Co., Ltd.). The measured L* was designated as "L* (ma)." The lower the L*, the blacker the color and the better the jet blackness.

[0090] Furthermore, for each thermoplastic resin composition, the content of the acetone-soluble polymer component (referred to as "acetone-soluble component amount" in Table 1 below) (mass %), the content of the rubbery polymer (referred to as "rubber content" in Table 1 below) (mass %), and the mass ratio of the rubber content to the acetone-soluble component amount (referred to as "rubber / acetone-soluble component ratio" in Table 1 below) were calculated as follows, based on 100 mass % of the thermoplastic resin component. The results are shown in Table 1.

[0091] <Amount of Acetone-Soluble Component> In Examples 1 to 13, 15, and 16 and Comparative Examples 1 to 3, the amount of acetone-soluble component was determined as a percentage of the content (parts by mass) of acetone-soluble component separated in the measurement of the graft ratio of component (C) per 100 parts by mass of the total of components (A) to (C) used as the thermoplastic resin components. In Example 14 and Comparative Examples 4 and 5, the amount of acetone-soluble component was determined as a percentage of the content of acetone-soluble component separated in the measurement of the graft ratio of component (C) per 100 parts by mass of the total of components (A) to (C) used as the thermoplastic resin components and the AS-based resin used as the other resin.

[0092] <Rubber Content> The rubber content in component (C) was determined based on a total of 100 parts by mass of components (A) to (C) used as the thermoplastic resin components and the AS-based resin, and the content percentage was calculated to determine the rubber content.

[0093] <Rubber / Acetone-Soluble Component Ratio> The rubber content calculated by the above method was divided by the amount of acetone-soluble components to obtain the rubber / acetone-soluble component ratio.

[0094] In Table 1, in the column for thermoplastic resin composition formulation, a blank space indicates that the component was not used.

[0095]

[0096] [Discussion] Excellent effects were exhibited in all of the evaluations of the thermoplastic resin compositions of Examples 1 to 16. In contrast, in Comparative Examples 1 to 5, the content of component (C) and the content of the acetone-soluble polymer component were outside the range of the present invention, and therefore chemical resistance and impact resistance were not obtained.

[0097] 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 invention. This application is based on Japanese Patent Application No. 2024-084990 filed on May 24, 2024, and is incorporated by reference in its entirety.

Claims

1. A thermoplastic resin composition comprising thermoplastic polyester resin (A), aromatic polycarbonate resin (B), and rubber-containing graft copolymer (C) as thermoplastic resin components, wherein the content of thermoplastic polyester resin (A) is 15 to 80 parts by mass, the content of aromatic polycarbonate resin (B) is 5 to 84 parts by mass, and the content of rubber-containing graft copolymer (C) is 1 to 15 parts by mass per 100 parts by mass of the thermoplastic resin components, and wherein the thermoplastic resin composition contains 4.5% by mass or less of an acetone-soluble polymer component per 100% by mass of the thermoplastic resin components.

2. The thermoplastic resin composition according to claim 1, wherein the content of the rubber polymer in the thermoplastic resin composition is 0.5 to 10% by mass based on 100% by mass of the thermoplastic resin component.

3. The thermoplastic resin composition according to claim 2, wherein the ratio of the content (mass%) of the rubber polymer to the content (mass%) of the acetone-soluble polymer component in the thermoplastic resin composition (mass ratio: rubber polymer / acetone-soluble polymer component) is 1 to 20.

4. A molded article obtained by molding the thermoplastic resin composition according to any one of claims 1 to 3.

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