Thermoplastic resin composition, resin molded article, and plated member

Abstract

The present invention relates to a thermoplastic resin composition containing 10-50 parts by mass of a rubber-containing graft copolymer (A) and 50-90 parts by mass of another resin per 100 parts by mass of a resin component, the rubber-containing graft copolymer (A) is obtained by graft polymerizing 30-80% by mass of a rubbery polymer (a1) with 20-70% by mass of a vinyl monomer mixture (a2) containing an aromatic vinyl monomer and a vinyl cyanide monomer. The content of the vinyl cyanide monomer component in the acetone-soluble component contained in the thermoplastic resin composition is 20-40 mass% of the total acetone-soluble component. The content of the metal oxide (D) in the thermoplastic resin composition is 4500 ppm or less.

Description

Technical Field

[0001] The present invention relates to a thermoplastic resin composition that has excellent appearance of a plating film (especially uneven small dots and plating unevenness) regardless of the thickness and formation site of the plating film, excellent formability of the plating film (in the present invention, sometimes referred to as plating property, electrodeposition property or covering property), can form a plating film with high adhesion strength, and can maintain excellent plating appearance even after thermal cycling. In addition, the present invention relates to a resin molded product of the thermoplastic resin composition and a plated component using the resin molded product. Background Art

[0002] Molded products made of ABS resin have excellent impact resistance, mechanical strength, and chemical resistance, and are therefore used in a wide range of fields such as office equipment, information / communication equipment, electronic / electrical equipment, household electric appliances, automobiles, and construction. In addition, when a molded product made of ABS resin is subjected to a plating treatment to obtain a plated product, it has excellent plating appearance, high adhesion strength of the plating film, and excellent thermal cycling characteristics, and is therefore used in various applications as a plastic plated component.

[0003] The plating characteristics of plastic plated components are easily affected by the characteristics of the resin composition forming the molded product and factors of the molding conditions. Even when using a resin composition containing ABS resin, there may be poor plating appearance.

[0004] As a thermoplastic resin composition having a high adhesion strength of the plating film and suppressing the expansion and reduction of the adhesion strength of the plating film during thermal cycling, a thermoplastic resin composition having improved plating property by a specified graft copolymer and oligomer content has been proposed (Patent Document 1).

[0005] However, even this thermoplastic resin composition has the following problems.

[0006] It is impossible to form a plating film at the desired site;

[0007] Even if it can be formed, there will be poor appearance;

[0008] Even if the initial plating film has a high adhesion strength, the adhesion strength after thermal cycling will decrease, which may damage the quality of the final product and even its function.

[0009] Prior Art Documents

[0010] Patent Documents

[0011] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-158706 Summary of the Invention

[0012] Problems to be Solved by the Invention

[0013] An object of the present invention is to provide a thermoplastic resin composition which has no defective appearance of a plating film (especially small bumps and uneven plating) regardless of the thickness and formation position of the plating film, has excellent plating properties, can form a plating film with high adhesion strength, and can maintain excellent plating appearance even after thermal cycling. Another object of the present invention is to provide a resin molded article and a plated component of the thermoplastic resin composition.

[0014] Means for solving the problems

[0015] The present inventors have found that by making the content of the cyanated vinyl monomer component in the acetone-soluble component in the thermoplastic resin composition within a specified range and making the content of the metal oxide below a specified value, the above problems can be solved.

[0016] The present invention has been achieved based on such an insight, and its gist is as follows.

[0017] [1] A thermoplastic resin composition comprising 10 to 50 parts by mass of a rubber-containing graft copolymer (A) and 50 to 90 parts by mass of other resins in 100 parts by mass of the resin component. The rubber-containing graft copolymer (A) is obtained by graft-polymerizing 30 to 80% by mass of a rubbery polymer (a1) with 20 to 70% by mass of a vinyl monomer mixture (a2) containing an aromatic vinyl-based monomer and a cyanated vinyl-based monomer (wherein the total of the rubbery polymer (a1) and the vinyl monomer mixture (a2) is 100% by mass).

[0018] The thermoplastic resin composition is characterized in that

[0019] the content of the cyanated vinyl monomer component in the acetone-soluble component contained in the thermoplastic resin composition is 20 to 40% by mass of all the acetone-soluble components,

[0020] the content of the metal oxide (D) in the thermoplastic resin composition is 4500 ppm or less.

[0021] [2] The thermoplastic resin composition according to [1], wherein, as the other resin, an AS-based resin (B) and / or an aromatic polycarbonate resin (C) is included.

[0022] [3] The thermoplastic resin composition according to [1] or [2], wherein, as the other resin, a recycled resin (E) is included.

[0023] [4] A resin molded article formed by molding the thermoplastic resin composition according to any one of [1] to [3].

[0024] [5]A plated component, which is obtained by plating a part or the whole of the resin molded article described in [4].

[0025] Advantages of the Invention

[0026] According to the thermoplastic resin composition of the present invention, for a resin molded article composed of the thermoplastic resin composition, regardless of the thickness and formation position of the plating film, there are no defects in the appearance of the plating film (especially uneven small dots and plating unevenness), the plating property is excellent, and a plating film having excellent appearance and high adhesion strength even after thermal cycling can be formed.

[0027] Therefore, even for a plating film with a thin thickness, a plating film having excellent appearance, excellent adhesion strength, and excellent durability against thermal cycling can be formed. Thus, it is possible to achieve weight reduction of the plated component without impairing the decorativeness, and it is possible to shorten the plating treatment time and reduce the defective product generation rate.

[0028] In addition, it is also possible to effectively utilize recycled resins and achieve product design considering the environment. Detailed Description of Embodiments

[0029] The embodiments of the present invention will be described in detail below.

[0030] In the present invention, a "resin molded article" refers to an article formed by molding the thermoplastic resin composition of the present invention.

[0031] A "plated component" refers to a component obtained by plating a resin molded article, and has a plating film on at least a part of the surface of the resin molded article.

[0032] In the present invention, "plating property" refers to electrodeposition property and covering property based on "formability of plating film" and "properties of the formed plating film".

[0033] The "~" indicating a numerical range means including the numerical values described before and after as the lower limit value and the upper limit value.

[0034] [Thermoplastic Resin Composition]

[0035] The thermoplastic resin composition of the present invention contains 10 to 50 parts by mass of a rubber-containing graft copolymer (A) (hereinafter sometimes referred to as "component (A)") and 50 to 90 parts by mass of other resins in 100 parts by mass of the resin component. The rubber-containing graft copolymer (A) is obtained by graft-polymerizing 20 to 70% by mass of a vinyl monomer mixture (a2) containing an aromatic vinyl monomer and a vinyl cyanide monomer onto 30 to 80% by mass of a rubbery polymer (a1) (wherein the total of the rubbery polymer (a1) and the vinyl monomer mixture (a2) is 100% by mass). The thermoplastic resin composition is characterized in that the content of the vinyl cyanide monomer component in the acetone-soluble component contained in the thermoplastic resin composition is 20 to 40% by mass of all the acetone-soluble components, and the content of the metal oxide (D) in the thermoplastic resin composition is 4500 ppm or less.

[0036] [Rubber-containing graft copolymer (A)]

[0037] The rubber-containing graft copolymer (A) is obtained by graft-polymerizing a vinyl monomer mixture (a2) in the presence of a rubbery polymer (a1).

[0038] [Rubbery polymer (a1)]

[0039] The rubbery polymer (a1) (hereinafter sometimes referred to as "component (a1)") constituting the rubber-containing graft copolymer (A) is not particularly limited. Examples of component (a1) include diene rubbers, acrylic rubbers, and ethylene rubbers. Specifically, 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), poly(ethylene-ethyl acrylate), etc. can be mentioned. These rubbery polymers are used in the form of one kind or a mixture of two or more kinds. Among them, polybutadiene, poly(butadiene-styrene), poly(butadiene-acrylonitrile), poly(butadiene-butyl acrylate), and poly(butadiene-methyl acrylate) are preferred. In addition, from the viewpoint of excellent impact resistance and plating properties of the thermoplastic resin composition of the present invention, polybutadiene and poly(butadiene-styrene) are preferably used.

[0040] From the viewpoints of the impact resistance, fluidity, and plating properties of the obtained thermoplastic resin composition, the volume average particle diameter of the rubbery polymer (a1) is preferably in the range of 50 to 500 nm, more preferably 150 to 400 nm, further preferably 250 to 340 nm, and most preferably 270 to 330 nm.

[0041] Here, the volume average particle diameter of the rubbery polymer (a1) is a value measured by the method described in the items of the following Examples.

[0042] The volume average particle diameter of the rubbery polymer (a1) can be measured at the time of use or can be confirmed by using image analysis or the like, and this image analysis uses an electron micrograph of the resin composition.

[0043] <Vinyl monomer mixture (a2)>

[0044] The vinyl monomer mixture (a2) (hereinafter sometimes referred to as "component (a2)") is a vinyl monomer mixture containing at least an aromatic vinyl monomer and a vinyl cyanide monomer.

[0045] Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, tert-butylstyrene, o-ethylstyrene, o-chlorostyrene, and o,p-dichlorostyrene. As the aromatic vinyl monomer, styrene and α-methylstyrene are particularly preferred. The aromatic vinyl monomer can be used alone or in combination of two or more.

[0046] Examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, and ethylacrylonitrile. As the vinyl cyanide monomer, acrylonitrile is particularly preferred. The vinyl cyanide monomer can be used alone or in combination of two or more.

[0047] From the viewpoints of the moldability of the obtained thermoplastic resin composition and the appearance of the molded article, the ratio of the aromatic vinyl monomer to the vinyl cyanide monomer in 100% by mass of the vinyl monomer mixture (a2) 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 further preferably 67 to 76% by mass / 24 to 33% by mass.

[0048] In addition to aromatic vinyl monomers and vinyl cyanide monomers, the vinyl monomer mixture (a2) may also contain other vinyl monomers copolymerizable therewith in the range of 0 to 30% by mass. Examples of other vinyl monomers copolymerizable therewith include 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; unsaturated amides such as acrylamide; and the like, one or more of these. However, it is not limited to these. Among them, methyl (meth)acrylate, N-phenylmaleimide, and maleic anhydride are preferred. It should be noted that "(meth)acrylic acid" means one or both of acrylic acid and methacrylic acid.

[0049] <Ratio of the rubbery polymer (a1) to the vinyl monomer mixture (a2)>

[0050] The rubber-containing graft copolymer (A) is obtained by graft-polymerizing 20 to 70% by mass of the vinyl monomer mixture (a2) in the presence of 30 to 80% by mass of the rubbery polymer (a1). Among them, the total of the rubbery polymer (a1) and the vinyl monomer mixture (a2) is 100% by mass.

[0051] If the proportion of the rubbery polymer (a1) is less than 30% by mass and the proportion of the vinyl monomer mixture (a2) exceeds 70% by mass, the impact resistance of the resulting thermoplastic resin composition tends to deteriorate. When the proportion of the rubbery polymer (a1) exceeds 80% by mass and the proportion of the vinyl monomer mixture (a2) is less than 20% by mass, the impact resistance and moldability tend to decrease. The proportion of the rubbery polymer (a1) is preferably 35 to 70% by mass, more preferably 40 to 65% by mass, and the proportion of the vinyl monomer mixture (a2) is preferably 30 to 65% by mass, more preferably 35 to 60% by mass.

[0052] The rubber-containing graft copolymer (A) does not need to be the entire amount of the grafted vinyl monomer mixture (a2), and a substance obtained as a mixture with the ungrafted copolymer is usually used. This mixture is originally a composition, but in the present invention, it is included in the rubber-containing graft copolymer (A). It should be noted that this ungrafted copolymer becomes the component extracted as the acetone-soluble component.

[0053] <Graft ratio>

[0054] The graft ratio of the rubber-containing graft copolymer (A) is not limited. From the aspect of impact resistance, the graft ratio of the rubber-containing graft copolymer (A) is preferably 10 to 150% by mass, more preferably 20 to 120% by mass, and further preferably 30 to 90% by mass.

[0055] The grafting ratio of the rubber-containing graft copolymer (A) is measured by the method described in the items of the following examples.

[0056] <Molecular weight of ungrafted copolymer>

[0057] The composition of the ungrafted copolymer in the rubber-containing graft copolymer (A), that is, the acetone-soluble component of the rubber-containing graft copolymer (A), falls within the range of the mixing ratio of the monomer components, that is, the vinyl-based monomer mixture (a2).

[0058] The weight-average molecular weight (Mw) of the ungrafted copolymer is preferably 20,000 to 400,000, more preferably 30,000 to 200,000, and still more preferably 40,000 to 100,000. The molecular weight distribution (Mw / Mn) of the ungrafted copolymer is preferably 2.0 to 4.0, more preferably 2.5 to 3.5, and still more preferably 2.7 to 3.2. By making the weight-average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) within the above ranges, the fluidity and impact resistance of the resulting thermoplastic resin composition tend to be more excellent.

[0059] Here, the weight-average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) of the ungrafted copolymer (acetone-soluble component) can be measured as values in terms of polystyrene conversion based on GPC. The details are as described in the items of the following examples.

[0060] <Graft polymerization method>

[0061] There is no particular limitation on the method for graft polymerization of the rubber-containing graft copolymer (A). The rubber-containing graft copolymer (A) can be produced by any method such as a known emulsion polymerization method, suspension polymerization method, continuous bulk polymerization method, continuous solution polymerization method, etc. Among them, the emulsion polymerization method is particularly preferred. The emulsion polymerization method has the following advantages: it is easy to adjust the rubber content of the rubber-containing graft copolymer (A); the formation of oligomers derived from the grafted monomers is extremely small; no organic solvents such as toluene or benzene are used, so they do not remain; and it is easy to adjust the rubber content, with excellent operability, product safety, etc., and is preferred.

[0062] In the process of production by the emulsion polymerization method, the coagulants used when recovering from the emulsified state include metal salts such as calcium chloride, calcium acetate, aluminum sulfate, and inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid. Among them, the graft copolymer recovered by an inorganic acid is preferred. Thereby, the influence on the adhesion strength of plating, the deterioration and discoloration of the thermoplastic resin composition is small, and the performance maintenance as the final component can be particularly extended.

[0063] The coagulant is selected according to the emulsifier. When using carboxylic acid soaps such as fatty acid soap or rosin acid soap as the emulsifier, any coagulant can be recovered. In this case, it is particularly preferred to carry out coagulation and recovery with an inorganic acid, especially sulfuric acid. However, if neutralization is carried out with sodium hydroxide or the like after coagulation with sulfuric acid, it is difficult to obtain the performance of the final component. Therefore, only washing with water after coagulation is sufficient.

[0064] The addition amount of the coagulant is usually 1 to 5 parts by mass, preferably in the range of 2 to 4 parts by mass, relative to 100 parts by mass of the polymer latex. The coagulant is usually a substance diluted to 1% to 20% in the form of a solution. The temperature during coagulation can be set appropriately. This temperature is usually in the range of 50 to 95 °C.

[0065] The rubber-containing graft copolymer (A) can be used alone. The rubber-containing graft copolymer (A) can be used by mixing various rubber-containing graft copolymers separately manufactured, such as those with different types of rubbery polymers, different rubber particle sizes, and different compositions of the graft copolymer components, according to the purpose.

[0066] <Content of rubber-containing graft copolymer (A)>

[0067] In the thermoplastic resin composition of the present invention, the content of the component (A) in 100 parts by mass in total of the resin components composed of the component (A) and other resins is 10 to 50 parts by mass, preferably 12 to 45 parts by mass, more preferably 15 to 40 parts by mass, and further preferably 20 to 35 parts by mass. If the content of the component (A) is above the above lower limit, the impact resistance and plating property become good. If the content of the component (A) is below the above upper limit, the moldability and the adhesion strength of the plating film become good.

[0068] <Content of rubbery polymer (a1)>

[0069] In the thermoplastic resin composition of the present invention, the content of the rubbery polymer (a1) is preferably 8 to 40% by mass, more preferably 10 to 30% by mass, and further preferably 12 to 20% by mass. If the content of the rubbery polymer (a1) is above the above lower limit, the impact resistance becomes good. If the content of the rubbery polymer (a1) is below the above upper limit, the moldability is excellent and the plating property of large molded articles and the like also becomes suitable.

[0070] [Other resins]

[0071] As other resins used in the present invention, any thermoplastic resin may be used without particular limitation. Examples of other resins include, for example, polyvinyl chloride resin, polystyrene resin, AS resin, polymethyl methacrylate resin, methyl methacrylate-styrene copolymer resin, methyl methacrylate-N-phenyl maleimide copolymer resin, aromatic polycarbonate resin, polyamide resin, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polyphenylene ether-polystyrene composite resin, olefin resins such as polypropylene resin and polyethylene resin, styrene-maleic anhydride copolymer resin, polyphenylene ether resin, polyoxymethylene resin, polysulfone resin, polyacrylate resin, polyphenylene resin, thermoplastic polyurethane, polylactic acid, bioplastics derived from plants, etc., and one or more of these. Among them, AS resin (B) and aromatic polycarbonate resin (C) described below are particularly preferred as impact-resistant and plating materials.

[0072] Other resins may also be resins (E) recycled from resin molded articles containing these thermoplastic resins.

[0073] In the thermoplastic resin composition of the present invention, the content of other resins in a total of 100 parts by mass of the resin components composed of component (A) and other resins is 50 to 90 parts by mass, preferably 55 to 88 parts by mass, more preferably 60 to 85 parts by mass, and further preferably 65 to 80 parts by mass. If the content of other resins is below the above upper limit, the impact resistance and plating properties become good. If the content of other resins is above the above lower limit, the adhesion strength of the plating film after thermal cycling becomes good.

[0074] [AS resin (B)]

[0075] AS resin (B) (hereinafter sometimes referred to as "component (B)") is a copolymer obtained by copolymerizing a vinyl monomer mixture (b1) containing a cyanated vinyl monomer and an aromatic vinyl monomer.

[0076] Examples of cyanated vinyl monomers include acrylonitrile, methacrylonitrile, ethyl acrylonitrile, etc. Acrylonitrile is particularly preferred. Only one type of cyanated vinyl monomer may be used, or two or more types may be used in combination.

[0077] Examples of aromatic vinyl monomers include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, tert-butylstyrene, o-ethylstyrene, o-chlorostyrene, o,p-dichlorostyrene. Styrene and α-methylstyrene are particularly preferred. Only one type of aromatic vinyl monomer may be used, or two or more types may be used in combination.

[0078] From the viewpoints of the moldability and plating properties of the resulting thermoplastic resin composition, the ratio of the vinyl cyanide-based monomer to the aromatic vinyl-based monomer in 100% by mass of the vinyl-based monomer mixture (b1) is vinyl cyanide-based monomer / aromatic vinyl-based monomer = 20 to 40% by mass / 60 to 80% by mass, preferably 22 to 38% by mass / 62 to 78% by mass, more preferably 24 to 35% by mass / 65 to 76% by mass, still more preferably 25 to 32% by mass / 68 to 75% by mass, and most preferably 25 to 29% by mass / 71 to 75% by mass.

[0079] In addition to the vinyl cyanide-based monomer and the aromatic vinyl-based monomer, the vinyl-based monomer mixture (b1) may contain other vinyl-based monomer units copolymerizable therewith in the range of 0 to 30% by mass. Examples of other vinyl-based monomers copolymerizable therewith include unsaturated carboxylic acid ester-based monomers such as methyl (meth)acrylate; maleimide-based monomers such as N-methylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide; unsaturated dicarboxylic acids such as maleic acid; unsaturated dicarboxylic anhydrides such as maleic anhydride; or unsaturated amides such as acrylamide; and one or more of these. However, it is not limited to these. Among them, methyl (meth)acrylate, N-phenylmaleimide, and maleic anhydride are preferred.

[0080] The weight-average molecular weight (Mw) of the AS resin (B) is preferably 50,000 to 300,000, more preferably 65,000 to 200,000, and still more preferably 80,000 to 150,000. The molecular weight distribution (Mw / Mn) of the AS resin (B) is preferably 1.3 to 2.8, more preferably 1.8 to 2.6, and still more preferably 1.7 to 2.4.

[0081] Here, the weight-average molecular weight and the molecular weight distribution (Mw / Mn) of the AS resin (B) can be measured as values in terms of polystyrene based on GPC. The details are as described in the items of the examples below.

[0082] The AS resin (B) may be used alone, or two or more substances having different monomer compositions, molecular weights, etc. may be mixed and used.

[0083] The method for manufacturing the AS resin (B) is not particularly limited, and examples thereof include bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc. If volatile components or oligomers are generated during the manufacturing stage, surface defects such as silver streaks are likely to occur when forming a resin molded article. Therefore, countermeasures such as discharging the gas from the molding die and cleaning the die are required to prevent defective products. In particular, oligomers are likely to be generated in bulk polymerization and solution polymerization. Therefore, for example, Japanese Patent Laid-Open No. 53-19397 describes methods for reducing oligomers. As a result, silver streaks or contamination of the molded article are less likely to occur, and thus the impact on subsequent secondary processing steps such as plating can also be reduced. In the case of suspension polymerization or emulsion polymerization where the generation of oligomers is originally so small that it cannot be detected, no adverse phenomena caused by oligomers will occur. In the case of emulsion polymerization with a large amount of emulsifier mixed, deterioration of thermal stability (color change due to heat) occurs due to the influence of the emulsifier. Therefore, suspension polymerization is preferably used.

[0084] [Aromatic polycarbonate resin (C)]

[0085] As the aromatic polycarbonate resin (C) (hereinafter sometimes referred to as "component (C)"), there is no particular limitation. As component (C), an aromatic polycarbonate resin having a viscosity-average molecular weight (Mv) of 10,000 to 100,000, particularly 15,000 to 30,000, is preferably used. If the viscosity-average molecular weight (Mv) of the aromatic polycarbonate resin (C) is within the above range, the impact resistance and moldability of the resulting molded article are more excellent.

[0086] Here, the viscosity-average molecular weight (Mv) of the aromatic polycarbonate resin (C) is measured using an Ubbelohde viscometer with a solution using dichloromethane as a solvent, and calculated using the following Schnell viscosity formula.

[0087] [η] = 1.23×10 -4 Mv 0.83

[0088] (In the formula, η represents the intrinsic viscosity, and Mv represents the viscosity-average molecular weight.)

[0089] Such an aromatic polycarbonate resin (C) is usually produced by reacting a dihydric phenol with a carbonate precursor by a solution method or a melt method. The dihydric phenol used here is 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), but a part or all of it can be replaced with other dihydric phenols. 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, bis(4-hydroxyphenyl) sulfone, etc.

[0090] Examples of the carbonate precursor include carbonyl halides, carbonyl esters, haloformates, etc. Specifically, phosgene, diphenyl carbonate, dihaloformates of dihydric phenols, and mixtures thereof can be mentioned.

[0091] When producing the aromatic polycarbonate resin (C), appropriate molecular weight regulators, branching agents, catalysts for promoting the reaction, etc. can also be used.

[0092] In the present invention, two or more kinds of the aromatic polycarbonate resins thus produced can also be used in combination. For example, two or more kinds of aromatic polycarbonate resins having different viscosity-average molecular weights (Mv) can be mixed and adjusted to the above-mentioned appropriate viscosity-average molecular weight (Mv) for use.

[0093] [Metal oxide (D)]

[0094] The metal oxide (D) in the present invention is not particularly limited. Examples of the metal oxide (D) include titanium oxide, zinc oxide, zinc sulfide, magnesium oxide, aluminum oxide, barium oxide, calcium oxide, molybdenum oxide, and antimony compounds (antimony trioxide). In addition, composite oxides thereof, such as titanium / antimony composite oxides and nickel / titanium / antimony composite oxides, can also be mentioned. In the following examples, titanium oxide, nickel / titanium / antimony composite oxide, and magnesium oxide were evaluated, but the metal oxide (D) of the present invention is only required to be an oxide of a metal and is not limited to these.

[0095] The thermoplastic resin composition of the present invention may contain only one kind of these metal oxides (D) or may contain two or more kinds of these metal oxides (D).

[0096] These metal oxides (D) are substances derived from colorants, stabilizers or modifiers of resins and incorporated into the thermoplastic resin composition.

[0097] If the average primary particle diameter of these metal oxides (D) is too small or too large, it may affect the plating property. Therefore, it is preferably in the range of 0.01 to 10 μm, more preferably 0.05 to 1 μm, and still more preferably 0.1 to 0.5 μm.

[0098] The average primary particle diameter of the metal oxide (D) can be calculated by observing 50 arbitrarily selected particles with an electron microscope and taking the average of the major axis and minor axis measured for each particle by analyzing the magnified image.

[0099] In the thermoplastic resin composition of the present invention, the content of the metal oxide (D) needs to be adjusted to 4500 ppm or less. If the content of the metal oxide (D) exceeds 4500 ppm, the appearance and plating property of the plating film will be impaired.

[0100] The content of the metal oxide (D) in the thermoplastic resin composition of the present invention is preferably 4000 ppm or less, more preferably 3000 ppm or less, still more preferably 2000 ppm or less, particularly preferably 1500 ppm or less, and even more preferably 1000 ppm or less, 600 ppm or less, 300 ppm or less, and 200 ppm or less in sequence.

[0101] The lower limit of the content of the metal oxide (D) in the thermoplastic resin composition is not particularly limited and may be 0 ppm, that is, the metal oxide (D) is not contained. In a particularly small range, the metal oxide (D) may be contained in an amount exceeding 0 ppm, 0.01 ppm or more, 0.05 ppm or more, 0.1 ppm or more, or 0.5 ppm or more. From the viewpoint of plating properties, the lower the content of the metal oxide (D), the more preferable. If the content of the metal oxide (D) is 200 ppm or less, no significant difference is found in plating properties and the like.

[0102] In order to make the content of the metal oxide (D) in the thermoplastic resin composition not exceed the above upper limit, for example, the following methods can be cited.

[0103] Prevent the mixing of metal oxides in the manufacturing processes of the rubber-containing graft copolymer (A) and other resins.

[0104] When using an additive containing a metal oxide or using a resin containing a metal oxide as the resin (E) for recycling described later, adjust its blending amount to control the content of the metal oxide (D) in the thermoplastic resin composition.

[0105] The method for measuring the content of the metal oxide (D) in the thermoplastic resin composition of the present invention is as described in the items of the following examples. The content of the metal oxide (D) can also be calculated from the content of the metal oxide (D) in each component used in the preparation of the thermoplastic resin composition.

[0106] As a measurement method based on analysis, for example, in the analysis using a fluorescent X-ray apparatus, a standard curve of its content and intensity can be prepared in advance from a sample with a known content according to the type of the metal oxide, the thermoplastic resin composition sample is measured using the fluorescent X-ray apparatus, and the content is obtained from the measured intensity. In addition, an infrared spectroscopic analyzer (IR) can also be used to obtain the content of the metal oxide by preparing a standard curve of the type and content of the metal oxide in advance.

[0107] In particular, in cases where the metal oxide content in the sample is small, etc., for the component obtained by separating the polymer component and the non-polymer component in the sample using a solvent or the like and removing the polymer component as much as possible, the metal oxide content can also be analyzed using a fluorescent X-ray apparatus or an infrared spectroscopic analyzer.

[0108] For recycled materials and the like, these measurement methods can also be used to analyze the content of metal oxides.

[0109] [Recycled resin (E)]

[0110] In the present invention, as other resins, recycled resin (E) (hereinafter sometimes referred to as "recycled resin (E)" or "component (E)"), such as recycled ABS resin, recycled AS resin, and recycled aromatic polycarbonate resin, can be blended.

[0111] The recycled resin (E) can be a post-consumer product or a pre-consumer product, and its supply source is not limited.

[0112] In the present invention, when using the recycled resin (E) as other resins, finally, for the thermoplastic resin composition containing the obtained recycled resin (E), it is preferably confirmed in advance at the raw material stage such that the content of the metal oxide (D) is below the above upper limit and the content of the cyanated vinyl monomer component in the acetone-soluble component is within the following range.

[0113] When the content of the metal oxide (D) is out of the specified range of the present invention, the rubber-containing graft copolymer (A), AS-based resin (B), and aromatic polycarbonate resin (C) can be blended again to adjust it within the limit. Thus, waste of the recycled resin (E) is not generated, and production can be carried out while considering the environment.

[0114] [Content of cyanated vinyl monomer component in acetone-soluble component]

[0115] The thermoplastic resin composition of the present invention is characterized in that the content of the cyanated vinyl monomer component in the acetone-soluble component contained in the thermoplastic resin composition is 20 to 40% by mass of all the acetone-soluble components. By making the content of the cyanated vinyl monomer component in the acetone-soluble component within this range, a thermoplastic resin composition with excellent plating properties is obtained.

[0116] From the viewpoint of plating properties, the content of the cyanated vinyl monomer component in all the acetone-soluble components is preferably 21 to 35% by mass, more preferably 22 to 33% by mass, and further preferably 24 to 30% by mass.

[0117] The content of the cyanated vinyl monomer component in the acetone-soluble component can be determined by a method of direct extraction measurement as described in the items of the following examples or a method calculated from the acetone-soluble components of the raw materials used.

[0118] <Molecular weight of acetone-soluble component>

[0119] The weight-average molecular weight (Mw) of the acetone-soluble component in the thermoplastic resin composition of the present invention is preferably from 20,000 to 400,000, more preferably from 30,000 to 200,000, and still more preferably from 40,000 to 180,000. By making the weight-average molecular weight (Mw) within the above range, the fluidity and impact resistance of the thermoplastic resin composition of the present invention tend to be more excellent.

[0120] Here, the weight-average molecular weight (Mw) of the acetone-soluble component in the thermoplastic resin composition can be measured as a polystyrene-converted value based on GPC. The details are as described in the items of the examples below.

[0121] [Additives]

[0122] In the thermoplastic resin composition of the present invention, additives that are usually compounded in thermoplastic resin compositions may be included as needed.

[0123] Examples of the 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-resistant agents, antioxidants, weather-resistant agents, mold release agents, plasticizers, antistatic agents, and the like.

[0124] However, in the thermoplastic resin composition after compounding such additives, it is preferable to use additives that do not contain metal oxides or contain a small amount of metal oxides in such a manner that the content of the metal oxide (D) is below the above upper limit.

[0125] [Manufacturing method of thermoplastic resin composition]

[0126] The thermoplastic resin composition of the present invention can be manufactured, for example, as follows.

[0127] The component (A) and other thermoplastic resins such as an AS-based resin (B), an aromatic polycarbonate resin (C), and a recycled resin (E), and various additives used as needed are mixed and dispersed by a V-type mixer or a Henschel mixer. The mixture thus obtained is melt-kneaded by a kneading machine such as an extruder, a Banbury mixer, a pressure kneader, or a roll, and then cut and pelletized by a pelletizer or the like.

[0128] The thermoplastic resin composition of the present invention is molded to produce the resin molded article of the present invention.

[0129] [Uses of thermoplastic resin composition]

[0130] The thermoplastic resin composition of the present invention is a thermoplastic resin composition that is excellent in moldability and physical properties and is further suitable for secondary processing. Examples of secondary processing include plating, painting, screen printing, etc. In particular, excellent effects are exhibited in plating applications.

[0131] [Resin molded article]

[0132] The resin molded article of the present invention is formed by molding the thermoplastic resin composition of the present invention. The resin molded article of the present invention is excellent in impact strength and moldability, and the appearance and plating properties of the plating film are excellent.

[0133] By adjusting the type and blending amount of other resins used in combination with the rubber-containing graft copolymer (A), etc., the resin molded article of the present invention can have excellent mechanical properties such as rigidity and heat resistance.

[0134] Examples of the molding method of the thermoplastic resin composition of the present invention include injection molding method, injection compression molding machine method, extrusion method, blow molding method, vacuum molding method, pressure air molding method, calendering method, blow-up molding method, gas injection molding method, etc. Among them, the injection molding method is preferred because molded articles with excellent mass productivity and high dimensional accuracy can be obtained.

[0135] [Plated component]

[0136] The plated component of the present invention is obtained by plating a part or all of the above-mentioned resin molded article of the present invention. The plated component of the present invention has the resin molded article of the present invention and a plating film formed on at least a part of the surface of the resin molded article.

[0137] The plated component of the present invention is obtained by performing a plating treatment on the resin molded article of the present invention. The plating treatment method is not limited in any way. Examples of the plating treatment method include electroless plating method, direct plating method, chromium-free plating method, etc.

[0138] The plated component of the present invention can provide an excellent component that exhibits sufficient effects in the conductor chemical process of plating, has an excellent appearance, and further has excellent formability of the conductive film, and exhibits effects even when the plating film is thin.

[0139] Thus, it can also contribute to weight reduction, etc. In addition, it has environmental effects such as shortening the plating treatment time, reducing the generation rate of defective products, and effectively using recycled resources.

[0140] In addition, as an additional effect, since the resin molded article of the present invention is used for the plated component of the present invention, the adhesion strength with the plating film is excellent, the thermal cycle resistance is also excellent, the adhesion of the plating film after thermal cycling can be maintained, and the plating appearance is also excellent.

[0141] [Use / Possibility of Utilization]

[0142] The specific uses of the coated component of the present invention involve multiple aspects. The coated component of the present invention is suitable for a wide range of uses such as industrial products such as automobiles, electrical / electronic / mechanical components, information / communication equipment, and water-washed components, as well as sports / leisure / game / decorative articles, office supplies, and daily necessities.

[0143] Specifically, as automotive uses, radiator grilles, door handles, emblems, lamp housings, various moldings and decorative parts, wheel covers, etc. can be cited.

[0144] As electrical (appliance) uses, various switch buttons, armrests, refrigerator door handles, mobile phone components, various housings, etc. can be cited.

[0145] As water-washed component uses, various water-washed handles, shower heads, drain outlets, etc. can be cited.

[0146] As sports / leisure / game / decorative articles and daily necessity uses, pachinko machines, pachislot machines, clock frames, decorative buttons, cosmetic caps, etc. can be cited.

[0147] Among them, the coated component of the present invention is preferably used for automotive exterior / interior parts, water-washed components, etc.

[0148] Examples

[0149] To more specifically illustrate the present invention, examples and comparative examples are given below for description. The following examples do not limit the present invention. Here, unless otherwise specified, "%" represents mass %, and "parts" represents mass parts.

[0150] As an abbreviation, there are also places where acrylonitrile is labeled as "AN", styrene is labeled as "ST", and butadiene is labeled as "BD".

[0151] Hereinafter, the volume average particle diameter of the rubbery polymer (a1) is measured by the following (1).

[0152] The grafting rate of the rubber-containing graft copolymer (A) is measured by the following (2).

[0153] The content of the vinyl cyanide monomer component in the acetone-soluble component of the thermoplastic resin composition is measured by the following (3).

[0154] By (3), the content of the vinyl cyanide monomer component in the acetone-soluble component (ungrafted copolymer) of the rubber-containing graft copolymer (A) and the acetone-soluble component of the AS-based resin (B) is also measured.

[0155] The weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the acetone-soluble component (ungrafted copolymer) of the rubber-containing graft copolymer (A), the AS-based resin (B), and the recycled resin (E) are measured by the following (4).

[0156] The method for measuring the viscosity-average molecular weight (Mv) of the aromatic polycarbonate resin (C) is as described above.

[0157] The content of the metal oxide (D) is analyzed by the following (5).

[0158] (1) Volume-average particle size

[0159] Using "Microtrac UPA150" (trade name) manufactured by HONEYWELL, the volume-average particle size in the latex of the rubbery polymer (a1) is measured at room temperature. The unit is nm.

[0160] It is known that there is no substantial difference between the latex particle size of the rubbery polymer (a1) and the rubber particle size of the rubbery polymer (a1) in the resin composition using it, and the former conforms to the latter.

[0161] (2) Grafting rate

[0162] The grafting rate of the rubber-containing graft copolymer (A) is calculated by the following formula.

[0163] Grafting rate (mass %) = {[(n) - (m) × L] / [(m) × L]} × 100

[0164] In the above formula, n is the mass n (g) of the acetone-insoluble component obtained by separating the acetone-insoluble component and the acetone-soluble component by putting about 1 g [weighing: m (g)] of the rubber-containing graft copolymer (A) into 20 mL of acetone, shaking with a shaker for 2 hours at a temperature of 25 °C, and then centrifuging at a temperature of 5 °C with a centrifuge (rotation speed: 23,000 rpm) for 60 minutes.

[0165] L is the mass (g) of the rubbery polymer (a1) contained in the rubber-containing graft copolymer (A). The mass of this rubbery polymer (a1) can be obtained by methods such as calculating from the polymerization formula and polymerization conversion rate, and by infrared absorption spectroscopy.

[0166] (3) Content of vinyl cyanide monomer component in acetone-soluble component

[0167] For Examples 1 to 9 and Comparative Examples 1 to 6, 2 g of each of the obtained thermoplastic resin compositions was put into 40 mL of acetone, shaken for 2 hours using a shaker under the temperature condition of 25°C, and then centrifuged for 60 minutes using a centrifuge (rotation speed: 23,000 rpm) under the temperature condition of 5°C to separate the acetone-soluble component and the acetone-insoluble component. The obtained acetone-soluble component was dropped into methanol to precipitate the polymer components, and then the solid components taken out by filtration were dried in a vacuum dryer for 24 hours. Nitrogen element analysis: JM10 MICRO CORDER (manufactured by J-SCIENCE-LAB Co., Ltd.) was used to measure the nitrogen element (N) therein. The content of the vinyl cyanide-based monomer unit was determined from the content of the nitrogen element (N) present in the sample, and this was taken as the content of the vinyl cyanide monomer component in the acetone-soluble component of the thermoplastic resin composition.

[0168] For the sample for the measurement of the ungrafted copolymer of component (A), the acetone-soluble component with the above grafting rate was dropped into methanol to precipitate the polymer components, and then the solid components taken out by filtration were dried in a vacuum dryer for 24 hours. The nitrogen element (N) of the dried product was measured to determine the content of the vinyl cyanide-based monomer unit.

[0169] For component (B), after dissolving the produced component (B) in acetone, the polymer components were precipitated in methanol, dried in a vacuum dryer for 24 hours, and the nitrogen element (N) of the dried product was measured to determine the content of the vinyl cyanide-based monomer unit.

[0170] In the case of containing an aromatic polycarbonate resin as in Examples 10 to 12 and Comparative Examples 7 to 9, there is the following method for measuring the content of the vinyl cyanide monomer component in the acetone-soluble component. However, in this example, for the acetone-soluble component of the raw materials used, the mixing ratio of each component was multiplied to calculate the amount of the vinyl cyanide-based monomer in the acetone-soluble component, etc.

[0171] The resin composition was dissolved in dichloromethane, and then the polymer components were extracted with methanol. The aromatic polycarbonate resin was decomposed by refluxing this polymer component with monoethanolamine. Then, it was washed with 1 / 10N hydrochloric acid and repeatedly washed again with methanol to remove the decomposition product. The remaining methanol-insoluble component was taken out and dried, and then, in the same manner as the operations in the above Example 1, etc., the acetone-soluble component and the insoluble component were separated, and the content of the vinyl cyanide monomer component in the acetone-soluble component was measured.

[0172] (4) Weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn)

[0173] Regarding the weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn), using GPC (GPC: "GPC / V2000" manufactured by Waters Corporation, column: manufactured by Showa Denko K.K., "Shodex AT-G + AT-806MS"), o-dichlorobenzene (145 °C) was used as the solvent, and the values were determined by polystyrene conversion measurement.

[0174] For the sample to be measured of the ungrafted copolymer, the acetone-soluble component with the above grafting rate was dropped into methanol to precipitate the polymer components, and then the solid components taken out by filtration were dried in a vacuum dryer for 24 hours, and the dried product was used for GPC measurement.

[0175] In addition, in the GPC measurement of component (B) and component (E), after dissolving component (B) and component (E) in acetone, the polymer components were precipitated in methanol and dried in a vacuum dryer for 24 hours, and the dried products were respectively used for GPC measurement.

[0176] (5) Content of metal oxide

[0177] Using a fluorescence X-ray energy dispersive type (EDX-7000) manufactured by SHIMADZU Corporation, a standard curve of its content was prepared in advance according to the type of metal oxide, and the content of the metal oxide was measured.

[0178] For the recycled products (E-1) and (E-2), the acetone-insoluble components were extracted, and after drying, the content of the metal oxide was measured using the same device.

[0179] [Grafted copolymer (A) containing rubber]

[0180] [Synthesis Example 1: Manufacture of grafted copolymer (A-1) containing rubber]

[0181] Into a reactor purged with nitrogen, 125 parts of pure water, 0.5 part of glucose, 0.5 part of sodium pyrophosphate, 0.005 part of ferrous sulfate, and 60 parts (in terms of solid content) of polybutadiene (BR) latex with a volume average particle diameter of 340 nm as the rubbery polymer (a1-1) were charged. While stirring, the temperature inside the reactor was raised to 65°C. The moment when the internal temperature reached 65°C was taken as the start of polymerization. 30 parts of styrene (ST) and 10 parts of acrylonitrile (AN) were used as the component (a2-1), and a mixture of 0.25 part of them and the chain transfer agent tert-dodecyl mercaptan was continuously added over 5 hours. At the same time, an aqueous solution composed of 0.2 part of cumene hydroperoxide as the polymerization initiator and 0.4 part of sodium disproportionated rosin salt was continuously added over 7 hours in parallel to end the reaction. In the resulting latex, 1 part of 2,2'-methylenebis(4-methyl-6-tert-butylphenol) was added per 100 parts of the latex solid content. Then, coagulation was carried out using 5% sulfuric acid at a ratio of 2 parts of coagulant per 100 parts of the latex (polymer component). After washing and filtering, it was dried to obtain a powdery rubber-containing graft copolymer (A-1).

[0182] The rubber (component (a1-1)) content of the rubber-containing graft copolymer (A-1) was 59.8%, and the grafting rate was 45%. In addition, the content of the vinyl cyanide monomer component in the acetone-soluble component was 24.8%, the weight-average molecular weight (Mw) was 48,000, and the molecular weight distribution (Mw / Mn) was 3.1.

[0183] <Synthesis Example 2: Production of rubber-containing graft copolymer (A-2)>

[0184] Into a reactor purged with nitrogen, 125 parts of pure water, 0.5 part of glucose, 0.5 part of sodium pyrophosphate, 0.005 part of ferrous sulfate, and 50 parts (in terms of solid content) of poly(butadiene-styrene) (SBR) latex with a volume average particle diameter of 310 nm as the rubbery polymer (a1-2) were charged. While stirring, the temperature inside the reactor was raised to 65°C. The moment when the internal temperature reached 65°C was taken as the start of polymerization. 35.5 parts of styrene (ST) and 14.5 parts of acrylonitrile (AN) were used as the component (a2-2), and a mixture of 0.20 part of them and the chain transfer agent tert-dodecyl mercaptan was continuously added over 5 hours. At the same time, an aqueous solution composed of 0.2 part of cumene hydroperoxide as the polymerization initiator and 0.7 part of sodium disproportionated rosin salt was continuously added over 7 hours in parallel to end the reaction. In the resulting latex, 1 part of 2,2'-methylenebis(4-methyl-6-tert-butylphenol) was added per 100 parts of the latex solid content. In the same manner as in Synthesis Example 1, a powdery rubber-containing graft copolymer (A2) was obtained.

[0185] The rubber (component (a1-2)) content of the rubber-containing graft copolymer (A-2) is 49.8%, and the grafting rate is 46%. In addition, the content of the vinyl cyanide monomer component in the acetone-soluble component is 28.7%, the weight-average molecular weight (Mw) is 68,000, and the molecular weight distribution (Mw / Mn) is 2.8.

[0186] <Synthesis Example 3: Production of rubber-containing graft copolymer (A-3)>

[0187] Into a reactor purged with nitrogen, 125 parts of pure water, 0.5 part of glucose, 0.5 part of sodium pyrophosphate, 0.005 part of ferrous sulfate, and 50 parts (in terms of solid content) of polybutadiene (BD) latex having a volume average particle diameter of 290 nm as the rubbery polymer (a1-3) were charged, and the temperature inside the reactor was raised to 65°C with stirring. The time when the internal temperature reached 65°C was taken as the start of polymerization. 37.5 parts of styrene (ST) and 12.5 parts of acrylonitrile (AN) were used as component (a2-3), and a mixture of these and 0.25 part of the chain transfer agent tert-dodecyl mercaptan was continuously added over 5 hours. At the same time, an aqueous solution composed of 0.2 part of cumene hydroperoxide as the polymerization initiator and 0.7 part of sodium disproportionated rosin salt was continuously added over 7 hours in parallel to end the reaction. In the resulting latex, 1 part of 2,2'-methylenebis(4-methyl-6-tert-butylphenol) was added per 100 parts of the latex solid content, and then, it was salted out with 5% calcium chloride at a ratio of 2 parts of the coagulant per 100 parts of the latex (polymer component), washed and filtered, and then dried to obtain a powdery rubber-containing graft copolymer (A-3).

[0188] The rubber (component (a1-3)) content of the rubber-containing graft copolymer (A-3) is 49.9%, and the grafting rate is 80%. In addition, the content of the vinyl cyanide monomer component in the acetone-soluble component is 26.9%, the weight-average molecular weight (Mw) is 67,000, and the molecular weight distribution (Mw / Mn) is 3.1.

[0189] [AS resin (B)]

[0190] <Synthesis Example 4: Production of AS resin (B-1)>

[0191] In a reactor purged with nitrogen, 120 parts of water, 0.002 part of sodium alkylbenzenesulfonate, 0.5 part of polyvinyl alcohol, 0.3 part of azoisobutyronitrile, 0.62 part of tert-dodecyl mercaptan, and a monomer mixture composed of 23 parts of acrylonitrile and 77 parts of styrene were used. While gradually adding a part of styrene, the temperature was raised from the starting temperature of 60°C and heated for 5 hours, and then reached 120°C. Further, after reacting at 120°C for 4 hours, the polymer was taken out to obtain an AS resin (B-1) with acrylonitrile / styrene = 23 / 77.

[0192] The content of the vinyl cyanide monomer component in the acetone-soluble component of the obtained AS resin (B-1) was 23.1%, the weight-average molecular weight (Mw) was 154,000, and the molecular weight distribution (Mw / Mn) was 2.1.

[0193] <Synthesis Example 5: Production of AS resin (B-2)>

[0194] Using 0.55 parts of tert-dodecyl mercaptan and a monomer mixture composed of 28 parts of acrylonitrile and 72 parts of styrene, an AS resin (B-2) with acrylonitrile / styrene = 27 / 73 was obtained in the same manner as in Synthesis Example 4.

[0195] The content of the vinyl cyanide monomer component in the acetone-soluble component of the obtained AS resin (B-2) was 28.2%, the weight-average molecular weight (Mw) was 116,000, and the molecular weight distribution (Mw / Mn) was 2.0.

[0196] <Synthesis Example 6: Production of AS resin (B-3)>

[0197] Using 0.65 parts of tert-dodecyl mercaptan and a monomer mixture composed of 35 parts of acrylonitrile and 65 parts of styrene, an AS resin (B-3) with acrylonitrile / styrene = 35 / 65 was obtained in the same manner as in Synthesis Example 4.

[0198] The content of the vinyl cyanide monomer component in the acetone-soluble component of the obtained AS resin (B-3) was 34.8%, the weight-average molecular weight (Mw) was 91,000, and the molecular weight distribution (Mw / Mn) was 2.1.

[0199] [Aromatic polycarbonate resin (C)]

[0200] As the aromatic polycarbonate resin (C), the following commercially available product was used.

[0201] Aromatic polycarbonate resin (C-1): "S3000" manufactured by Mitsubishi Engineering-Plastics Corporation (viscosity-average molecular weight (Mv): 22,000)

[0202] [Metal oxide (D)]

[0203] As the metal oxide (D), the following commercially available product was used.

[0204] Magnesium oxide (D-1): "Kyowamag 150" manufactured by Kyowa Chemical Industry Co., Ltd. (average primary particle size: 4.16 μm)

[0205] Ti / Sb / Ni Composite Oxide (D-2): "42-401A" manufactured by TOMATEC Co., Ltd. ((Ti, Sb, Ni)O2, average primary particle size: 1 μm)

[0206] Titanium Oxide (D-3): "TITANIX JR-405" manufactured by TAYCA Corporation (titanium dioxide, average primary particle size: 0.3 μm)

[0207] [Recycled Resin (E)]

[0208] <Recycled Product of ABS Resin (E-1)>

[0209] The recycled ABS resin (white) recovered from the market was analyzed. As a result, the metal oxide content (titanium oxide) was 30,000 ppm. Additionally, in the resin composition, the rubber content was 13.1%, and the grafting rate was 76%. Also, the content of the vinyl cyanide monomer component in the acetone-soluble component was 25.3%, the weight-average molecular weight (Mw) was 132,000, and the molecular weight distribution (Mw / Mn) was 2.4.

[0210] It was used as the recycled product of ABS resin (E-1).

[0211] <Recycled Product of ABS Resin (E-2)>

[0212] The recycled ABS resin (black) recovered from the market was analyzed. As a result, the metal oxide content (Ti / Sb / Ni composite oxide) was 5,000 ppm. Additionally, in the resin composition, the rubber content was 14.9%, and the grafting rate was 68%. Also, the content of the vinyl cyanide monomer component in the acetone-soluble component was 23.4%, the weight-average molecular weight (Mw) was 158,000, and the molecular weight distribution (Mw / Mn) was 2.6.

[0213] It was used as the recycled product of ABS resin (E-2).

[0214] <Recycled Product of Aromatic Polycarbonate Resin (E-3)>

[0215] The aromatic polycarbonate resin recovered from unwanted optical discs was used.

[0216] The recycling method is as described below.

[0217] Forty recovered optical discs were placed in a CD stripping solution (manufactured by Nippon Marcel Co., Ltd.), slowly stirred with a rod, and immersed for 15 minutes to dissolve and remove the metal part. Then, the disc-shaped aromatic polycarbonate resin was washed with water and dried. These operations were repeated a total of 200 times.

[0218] The obtained disc-shaped aromatic polycarbonate resin was placed in a crusher to form a size of about 4 mm × 4 mm. The viscosity-average molecular weight (Mv) of the recycled aromatic polycarbonate resin (E-3) was 15,000.

[0219] [Examples 1 to 12, Comparative Examples 1 to 9]

[0220] For the substances corresponding to the components (A), (B), (D), and (E) shown in Tables 1 and 2, they were mixed at the compounding ratios (parts) in the tables. In addition, 0.2 part of ADK STAB “A-60 (trade name)” (tetrakis[methylene-3-(3’,5’-di-tert-butyl-4’-hydroxyphenyl)propionate]methane) manufactured by ADEKA Corporation and 0.1 part of “KAOWAX EB-G (trade name)” (ethylene bisstearamide) manufactured by Kao Corporation were compounded and mixed. The mixture was melt-kneaded using a twin-screw extruder with a screw diameter of 30 mm and a vacuum vent (PCM30 manufactured by Ikegai Corporation) at a barrel temperature of 200 to 260 °C and a vacuum of 93.325 kPa. While pulling out the kneaded product in the form of a strand, it was pelletized using a pelletizer (SH type pelletizer manufactured by Soken Corporation) to obtain pellets of the thermoplastic resin composition.

[0221] The weight-average molecular weight (Mw) of the acetone-soluble component in the obtained thermoplastic resin composition was measured by the above method, and the results are shown in Table 1 as “weight-average molecular weight (Mw) of the acetone-soluble component”.

[0222] In addition, the content of the vinyl cyanide monomer component in the acetone-soluble component of the thermoplastic resin composition was measured by the above method, and the results are shown in Table 1 as “content of the vinyl cyanide monomer component in the acetone-soluble component”.

[0223] The following tests were carried out using the obtained pellets of the thermoplastic resin composition, and the results are shown in Tables 1 and 2.

[0224] [Evaluation of fluidity: Measurement of melt volume-flow rate (MVR)]

[0225] For the pellets of each thermoplastic resin composition, the MVR (cm 3 / 10 min) of the thermoplastic resin composition was measured according to ISO 1133 standard under the conditions of a temperature of 220 °C and a load of 98 N (10 kg). MVR is an index of the fluidity of the thermoplastic resin composition, and the higher the MVR, the more excellent the fluidity.

[0226] [Fabrication and test method of evaluation test pieces]

[0227] [Fabrication of test piece (a)]

[0228] Using an injection molding machine (manufactured by Shibaura Machine Co., Ltd., trade name “IS55FP-1.5A”), pellets of each thermoplastic resin composition were injection molded under the conditions of a barrel temperature of 220 to 250 °C and a mold temperature of 60 °C to obtain test piece (a) with a length of 80 mm, a width of 10 mm, and a thickness of 4 mm. Test piece (a) was used for the determination of the Charpy impact strength.

[0229] <Evaluation of impact resistance: Determination of Charpy impact strength>

[0230] For test piece (a), a Charpy impact test (notched) was carried out at 23 °C in accordance with ISO 179 standard to determine the Charpy impact strength. The higher the value, the more excellent the impact resistance.

[0231] <Production of test piece (b)>

[0232] Pellets of each thermoplastic resin composition were injection molded using a 75-ton injection molding machine (“JSW-75EIIP manufactured by Nippon Steel Works, Ltd.) and a model for evaluating plating adhesion strength (length 90 mm × width 50 mm × thickness 3 mm) under the conditions of a barrel temperature of 250 °C, a mold temperature of 60 °C, and an injection speed of 20 mm / sec to obtain test piece (b).

[0233] <Plating process 1>

[0234] For test piece (b), a 1-cm portion on the side opposite to the gate (lower side) was masked. The obtained plating flat plate was immersed in a CRP cleaner (manufactured by Okuno Pharmaceutical Co., Ltd.) at 50 °C for 5 minutes for degreasing. After degreasing, the flat plate was washed with water at 20 °C and then immersed in an etching solution (chromic acid: 400 g / L, sulfuric acid: 200 cc / L) at 68 °C for 10 minutes for etching. After etching, the flat plate was washed with water at 20 °C and then immersed in a CRP reducing agent (manufactured by Okuno Pharmaceutical Co., Ltd.) at 25 °C for 1 minute for neutralization. After neutralization, the flat plate was washed with water at 20 °C and then pre-immersed in hydrochloric acid at 25 °C for 1 minute. Then, it was immersed in a CRP catalyst (manufactured by Okuno Pharmaceutical Co., Ltd.) at 40 °C for 5 minutes for Pd-Sn colloid catalyst treatment. After catalyst treatment, the flat plate was washed with water at 20 °C and then immersed in CRP selectors A and B (manufactured by Okuno Pharmaceutical Co., Ltd.) at 45 °C for 7 minutes for conductivity treatment. After conductivity treatment, the flat plate was washed with water at 20 °C. Then, electroplating with copper was carried out at 20 °C for 40 minutes to deposit electroplated copper with a film thickness of 30 μm on the flat plate. After electroplating with copper, the flat plate was washed with water at 20 °C and then dried at 80 °C for 2 hours to obtain a plated sample 1.

[0235] <Plating property evaluation 1>

[0236] [Appearance: Visual inspection]

[0237] For the plated sample 1, visually inspect whether there are any unevenness such as bumps or pits on the surface and whether non-uniformity has occurred, and make a judgment according to the following criteria.

[0238] ◎: No problem at all (qualified product)

[0239] ○: There are small bumps, pits, non-uniformity, etc. (usable considering subsequent plating)

[0240] △: There are medium-sized bumps, pits, non-uniformity, etc. (high possibility of being a non-conforming product)

[0241] ×: Bumps, pits, and non-uniformity are widespread and cannot be processed (non-conforming product: unusable)

[0242] [Electrodeposition property: Coverage]

[0243] Visually inspect whether a copper plating conductive film has been formed with good adhesion on the surface of the plated sample 1 and whether electrodeposition has occurred, and make a judgment according to the following criteria.

[0244] ◎: No problem at all (qualified product)

[0245] 〇: Electrodeposition has not occurred in areas with little influence such as the docking point part (usable)

[0246] △: 10% has not been electrodeposited (not covered, unusable)

[0247] ×: More than 10% has not been electrodeposited (not covered, unusable)

[0248] [Adhesion strength]

[0249] For the plated sample 1, make a 1-cm-wide incision in the plating film from the masked part, and peel the plating film vertically on the load measuring device from the unplated part to measure its strength. Based on the measured value, judge the plating adhesion strength according to the following criteria.

[0250] ◎: The plating adhesion strength is 12 N / cm or more, which is very excellent.

[0251] ○: The plating adhesion strength is 9 N / cm or more and less than 12 N / cm, and there is no problem in practical use

[0252] △: The plating adhesion strength is 9 N / cm or less, and it is at a level that can be used according to the application.

[0253] <Plating process 2>

[0254] For the test piece (b), a 1 cm portion on the side opposite to the gate (lower side) was masked. Then, the flat plate for plating was immersed in CRP cleaner (manufactured by Okuno Pharmaceutical Co., Ltd.) at 50 °C for 5 minutes for degreasing. After degreasing, the flat plate was washed with water at 20 °C and then immersed in an etching solution (chromic acid: 400 g / L, sulfuric acid: 200 cc / L) at 68 °C for 10 minutes for etching. After etching, the flat plate was washed with water at 20 °C and then immersed in a CRP reducing agent (manufactured by Okuno Pharmaceutical Co., Ltd.) at 25 °C for 1 minute for neutralization. After neutralization, the flat plate was washed with water at 20 °C, pre-soaked in hydrochloric acid at 25 °C for 1 minute, and then immersed in a CRP catalyst (manufactured by Okuno Pharmaceutical Co., Ltd.) at 40 °C for 5 minutes for Pd-Sn colloid catalyst treatment. After the catalyst treatment, the flat plate was washed with water at 20 °C and then immersed in CRP selective agents A and B (manufactured by Okuno Pharmaceutical Co., Ltd.) at 45 °C for 7 minutes for conductor formation treatment. After the conductor formation treatment, the flat plate was washed with water at 20 °C. Then, electroplating of copper was carried out at 20 °C for 15 minutes, and electroplated copper with a film thickness of 10 μm was deposited on the flat plate.

[0255] After electroplating copper, the flat plate was washed with water at 20 °C and then electroplating of nickel was carried out at 55 °C for 8 minutes to further deposit electroplated nickel with a film thickness of 5 μm. After electroplating nickel, the flat plate was washed with water at 20 °C and then electroplating of chromium was carried out at 45 °C for 2 minutes to further deposit electroplated chromium with a film thickness of 0.3 μm. Then, the test piece was dried at 80 °C for 2 hours. Also, the mask was removed and the non-plated part was fabricated at the same time to obtain the plated sample 2.

[0256] <Plating property evaluation 2>

[0257] [Appearance: Visual inspection]

[0258] For the plated sample 1, visually investigate whether there are unevenness such as bumps and dents on the surface and whether non-uniformity has occurred, and make a judgment according to the following criteria.

[0259] ◎: No problem at all (qualified product)

[0260] ○: There are small bumps, dents, non-uniformity, etc. (usable considering subsequent plating)

[0261] △: There are medium-sized bumps, dents, non-uniformity, etc. (high possibility of being a non-conforming product)

[0262] ×: Bumps, dents, and non-uniformity are widely present and cannot be processed (non-conforming product: unusable)

[0263] [Appearance after thermal cycling]

[0264] For the coated sample 2, cooling at -40°C for 1 hour and heating at 80°C for 1 hour were taken as 1 cycle, and 8 cycles were performed. Then, the state of the coating film of sample 2 was visually observed, and the appearance after the thermal cycle was judged according to the following criteria.

[0265] ◎: No discoloration, etc. (qualified product)

[0266] ○: Very little discoloration, swelling, etc. (considered usable)

[0267] △: Slight swelling, etc. (usable according to the application)

[0268] ×: There are widespread uneven small dots, unevenness, etc., and it cannot be processed (non-conforming product, unusable)

[0269] [Table 1]

[0270]

[0271]

[0272] ※: Unable to evaluate.

[0273] [Table 2]

[0274]

[0275]

[0276] ※: Unable to evaluate.

[0277] [Discussion]

[0278] The thermoplastic resin compositions of Examples 1 to 12 showed excellent effects in the evaluation of plating properties.

[0279] In contrast, in Comparative Examples 1 to 9, since the metal oxide content exceeded the scope of the present invention, there were problems of poor appearance due to uneven small dots or unevenness. In addition, they could not obtain the conductivity for plating nor the adhesion strength.

[0280] The present invention has been described in detail using specific methods, but as is known to those skilled in the art, various changes can be made within the scope of achieving the invention effects.

[0281] This application is based on Japanese Patent Application 2023-062220 filed on April 6, 2023, the entire content of which is incorporated herein by reference.

Claims

1. A thermoplastic resin composition, comprising 10 to 50 parts by mass of a rubber-containing graft copolymer (A) and 50 to 90 parts by mass of other resins in 100 parts by mass of a resin component, wherein the rubber-containing graft copolymer (A) is obtained by graft-polymerizing 30 to 80 parts by mass of a rubber polymer (a1) with 20 to 70 parts by mass of a vinyl monomer mixture (a2) containing an aromatic vinyl monomer and a cyanide vinyl monomer, wherein: The total amount of the rubber polymer (a1) and the vinyl monomer mixture (a2) is 100% by mass. The thermoplastic resin composition is characterized in that The content of the vinyl cyanide monomer component in the acetone-soluble component contained in the thermoplastic resin composition is 20% to 40% by mass of the total acetone-soluble component. The content of the metal oxide (D) in the thermoplastic resin composition is 4500 ppm or less.

2. The thermoplastic resin composition according to claim 1, wherein The other resins include AS-based resin (B) and / or aromatic polycarbonate resin (C).

3. The thermoplastic resin composition according to claim 1, wherein As the other resin, a recycled resin (E) is included. 4 . A resin molded article obtained by molding the thermoplastic resin composition according to claim 1 .

5. A plated component, wherein a part or the whole of the resin molded product according to claim 4 is plated.

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