Resin composition for plating and plated molded product

Abstract

To provide a resin composition for plating that is made of a graft copolymer containing a rubbery polymer and excellent in fluidity and adhesion strength of a molded article to plating.SOLUTION: A resin composition for plating contains a graft copolymer (A) obtained by graft-polymerizing a rubbery polymer and monomer components containing an aromatic vinyl-based monomer and an acrylic block copolymer (B), and may further contain the other thermoplastic resin (C). The total content of the graft copolymer (A) and the other thermoplastic resin (C) is 51-99.5 mass% and the content of the acrylic block copolymer (B) is 0.5-49 mass% to 100 mass% of the total content of the graft copolymer (A), the acrylic block copolymer (B), and the other thermoplastic resin (C).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition for plating use and a plated molded article. More specifically, the present invention relates to a resin composition for plating use and a plated molded article obtained by plating an article molded from the resin composition for plating use. [Background technology]

[0002] Styrene-based resins, typified by ABS resin, have excellent moldability and a balance of mechanical properties, as well as excellent paintability and electrical insulation properties, and are therefore used in a wide range of fields, including vehicle interior and exterior parts, building materials, home appliances, electrical and electronic devices, office equipment parts, and office automation equipment.

[0003] Molded products using ABS resin are often required to have a designable appearance. For example, when ABS resin is used as a substitute for metal for the purpose of weight reduction, the ABS resin is often plated with a decorative metallic finish. Resin compositions using ABS resin for plating are disclosed in Patent Documents 1 and 2, for example. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-292921 [Patent Document 2] International Publication No. 2018 / 008669 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, resin compositions for plating that use graft copolymers obtained by graft polymerization of a rubbery polymer, such as ABS resin, with a monomer component containing an aromatic vinyl monomer are required to have even better adhesion strength to the plating of molded articles. One possible way to improve this adhesion strength is to increase the blending ratio of the rubbery polymer. However, this approach has the problem of reducing the fluidity of the resin composition and making it less moldable.

[0006] The thermoplastic resin composition of Patent Document 1 is described as improving the melt fluidity of ABS resin without impairing its plating ability. However, when a specific copolymer, which is a component for improving melt fluidity in Patent Document 1, is blended, the adhesive strength of the molded article to the plating decreases. For this reason, there is a demand for a resin composition for plating that uses the above graft copolymer and that has excellent adhesive strength to the plating of the molded article without reducing the fluidity of the resin composition.

[0007] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resin composition for plating use which uses a graft copolymer containing a rubbery polymer and which has excellent flowability and adhesive strength for plating on molded articles. [Means for solving the problem]

[0008] As a result of extensive research to achieve the above object, the present inventors have found that by blending a graft copolymer containing a rubber polymer with an acrylic block copolymer in a specific ratio, a resin composition for plating use that is excellent in flowability and adhesive strength to plating on molded articles can be obtained. The present disclosure relates to a product that has been completed based on these findings.

[0009] That is, the present invention provides a composition comprising a graft copolymer (A) in which a rubber polymer and a monomer component containing an aromatic vinyl monomer are graft polymerized, and an acrylic block copolymer (B), and may further comprise another thermoplastic resin (C), Provided is a resin composition for plating, in which the total content of the graft copolymer (A) and the other thermoplastic resin (C) is 51 to 99.5 mass%, and the content of the acrylic block copolymer (B) is 0.5 to 49 mass%, relative to 100 mass% of the total of the graft copolymer (A), the acrylic block copolymer (B), and the other thermoplastic resin (C).

[0010] The rubbery polymer preferably contains a conjugated diene rubber.

[0011] The above monomer component preferably further contains a vinyl cyanide monomer.

[0012] The content of the rubbery polymer is preferably 7 to 20% by mass relative to 100% by mass of the total of the graft copolymer (A), the acrylic block copolymer (B), and the other thermoplastic resin (C).

[0013] The acrylic block copolymer (B) preferably has a Shore hardness (type A) of 10-99.

[0014] The melt flow rate of the acrylic block copolymer (B) at 230° C. is preferably 30 g / 10 min or more.

[0015] The acrylic block copolymer (B) is preferably a block copolymer of an acrylic acid ester polymer block and a methacrylic acid ester polymer block.

[0016] The above-mentioned resin composition for plating use preferably contains an aromatic vinyl-vinyl cyanide copolymer and / or a polycarbonate resin as the other thermoplastic resin (C).

[0017] The present invention also provides a plated molded article obtained by plating a molded article made from the above-mentioned resin composition for plating use. [Effects of the Invention]

[0018] The resin composition for plating of the present invention uses a graft copolymer containing a rubber polymer, and has excellent flowability and excellent adhesion strength to plating of molded articles. Furthermore, by using the resin composition for plating, molded articles having excellent impact resistance can be obtained. DETAILED DESCRIPTION OF THE INVENTION

[0019] The resin composition for plating use of the present invention contains at least a graft copolymer (A) obtained by graft polymerization of a rubber polymer with a monomer component containing an aromatic vinyl monomer, and an acrylic block copolymer (B). The resin composition for plating use of the present invention may contain a thermoplastic resin (C) other than the graft copolymer (A) and the acrylic block copolymer (B).

[0020] The resin composition for plating of the present invention is a resin composition used in applications where the surface of a molded article is subjected to a metallic surface treatment (plating).

[0021] (Graft polymer (A)) The graft copolymer (A) is obtained by graft polymerization of a rubber polymer and a monomer component containing an aromatic vinyl monomer. One type of graft polymer (A) may be used alone, or two or more types may be used.

[0022] The rubbery polymer is not particularly limited, and examples thereof include those obtained by known or conventional polymerization methods. Examples of the rubbery polymer include conjugated diene rubbers such as polybutadiene rubber, styrene-butadiene rubber (SBR), and acrylonitrile-butadiene rubber (NBR); ethylene-propylene rubbers such as ethylene-propylene rubber and ethylene-propylene-non-conjugated diene (ethylidene norbornene, dicyclopentadiene, etc.) rubber; acrylic rubbers such as polybutyl acrylate rubber; and silicone rubbers. The rubbery polymers may be used singly or in combination of two or more.

[0023] The acrylic rubber also includes rubbers having a core-shell structure. Examples of rubbers having a core-shell structure (referred to as core / shell) include conjugated diene rubber / acrylic rubber, silicone rubber / acrylic rubber, and hard polymer (polymer with a glass transition temperature of 20°C or higher) / acrylic rubber. Examples of the hard polymer include polymers containing structural units derived from one or more monomers selected from the group consisting of aromatic vinyl monomers, vinyl cyanide monomers, and (meth)acrylic acid ester monomers. The glass transition temperature of the hard polymer can be calculated using the FOX formula.

[0024] Among the rubbery polymers, polybutadiene rubber, styrene-butadiene rubber, ethylene-propylene-non-conjugated diene rubber, and acrylic rubber are preferred. As the acrylic rubber, rubber having a core-shell structure is preferred, and more preferred are conjugated diene rubber / acrylic rubber, silicone rubber / acrylic rubber, and hard polymer / acrylic rubber (referred to as core / shell).

[0025] The mass average particle size of the rubber polymer is not particularly limited, but is preferably 0.1 to 2.0 μm from the viewpoint of excellent impact resistance of the molded article, and more preferably 0.2 to 1.0 μm from the viewpoint of even better adhesion strength of the molded article to plating. The mass average particle size can also be adjusted by aggregating and enlarging a rubber polymer having a mass average particle size of 0.05 to 0.3 μm.

[0026] The graft copolymer (A) is obtained by graft polymerizing the above rubbery polymer with a monomer component containing an aromatic vinyl monomer.

[0027] The content of the rubber polymer in the graft copolymer (A) is preferably 20 to 80 mass%, more preferably 40 to 70 mass%, relative to 100 mass% of the total amount of the graft copolymer (A), from the viewpoint of achieving a better balance of physical properties such as flowability and impact resistance of the molded product.

[0028] The aromatic vinyl monomer constituting the graft copolymer (A) may be a monomer having a styrene structure (a styrene monomer). Examples of the styrene monomer include styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, p-isobutylstyrene, pt-butylstyrene, bromostyrene, and chloromethylstyrene. Among these, styrene and α-methylstyrene are preferred. The aromatic vinyl monomer may be used alone or in combination of two or more.

[0029] The monomer component may contain, in addition to the aromatic vinyl monomer, other monomers copolymerizable with the aromatic vinyl monomer. Examples of the other monomers include vinyl cyanide monomers, (meth)acrylic acid ester monomers, amide monomers, and unsaturated carboxylic acid monomers. One or more of the other monomers may be used.

[0030] Examples of the vinyl cyanide monomer include nitrile group-containing monomers such as acrylonitrile, methacrylonitrile, ethacrylonitrile, and fumaronitrile. Examples of the (meth)acrylic acid ester monomer include alkyl (meth)acrylates having an alkyl group that may have a substituent, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, phenyl (meth)acrylate, 4-t-butylphenyl (meth)acrylate, dibromophenyl (meth)acrylate, and chlorophenyl (meth)acrylate. Examples of the amide monomer include amide group-containing monomers such as acrylamide and methacrylamide. Examples of the unsaturated carboxylic acid monomer include carboxy group-containing monomers such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid.

[0031] The content of the aromatic vinyl monomer in the monomer component is preferably 30 to 95% by mass, more preferably 50 to 90% by mass, and even more preferably 60 to 80% by mass, based on 100% by mass of the total amount of the monomer component. The content of the other monomer is preferably 5 to 70% by mass, more preferably 10 to 50% by mass, and even more preferably 20 to 40% by mass, based on 100% by mass of the total amount of the monomer component.

[0032] The graft ratio of the graft copolymer (A) is not particularly limited, but from the viewpoint of achieving a better balance of physical properties such as flowability and impact resistance of molded articles, it is preferably 20 to 150% by mass, more preferably 30 to 100% by mass, and even more preferably 36 to 75% by mass. The reduced viscosity of the acetone-soluble portion of the graft copolymer (A) is not particularly limited, but is preferably 0.1 to 1.5 dL / g, more preferably 0.2 to 0.6 dL / g.

[0033] The graft ratio and the reduced viscosity of the acetone soluble matter can be determined as follows.

[0034] <Separation method> Approximately 2 g of graft copolymer (A) and 60 ml of acetone are placed in an Erlenmeyer flask and left to soak for 24 hours. The mixture is then centrifuged at 15,000 rpm for 30 minutes to separate the soluble and insoluble fractions. The insoluble fraction is obtained by drying overnight at room temperature using a vacuum dryer. The soluble fraction is obtained by precipitating the acetone-soluble fraction in methanol and then drying overnight at room temperature using a vacuum dryer. <Grafting rate> Graft rate (mass%) = (X-Y) / Y x 100 X: Amount of acetone insoluble matter after vacuum drying (g) Y: Amount of rubber polymer in the graft copolymer (g) <Reduced viscosity of acetone solubles (dl / g)> The acetone soluble portion is dissolved in N,N-dimethylformamide to give a solution with a concentration of 0.4 g / 100 ml, and the reduced viscosity is determined from the flow time measured at 30°C using a Cannon-Fenske viscometer.

[0035] When preparing the graft copolymer (A), it usually contains a grafted polymer (component a1) in which a monomer component containing an aromatic vinyl monomer is grafted onto a rubbery polymer, but it may also produce a copolymer (component a2) in which a monomer component containing an aromatic vinyl monomer that is not grafted onto the rubbery polymer is copolymerized. The copolymer (a2) component corresponds to the other thermoplastic resin (C).

[0036] (Acrylic block copolymer (B)) The acrylic block copolymer (B) is a block copolymer having a polymer block that is a soft segment and a polymer block that is a hard segment. Only one type of acrylic block copolymer (B) may be used, or two or more types may be used.

[0037] The acrylic block copolymer (B) contains an acrylic monomer (a monomer having an acryloyl group or a methacryloyl group) as a monomer component constituting at least one polymer block of the soft segment and the hard segment.

[0038] The acrylic monomer constituting the soft segment is preferably an acrylic ester. That is, the polymer block of the soft segment is preferably an acrylic ester polymer block (b1). Examples of the acrylic ester include acrylic esters having a hydrocarbon group that may have an alkoxy group (particularly, an alkyl acrylate ester that may have an alkoxy group), such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate, isobornyl acrylate, phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, and 2-methoxyethyl acrylate. The hydrocarbon group in the acrylic ester may be an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group in which two or more of these are combined. The acrylic monomers may be used alone or in combination of two or more.

[0039] As the acrylic monomer constituting the acrylic ester polymer block (b1), from the viewpoint of achieving better fluidity and impact resistance of molded articles, preferred are acrylic esters having a hydrocarbon group with 1 to 22 carbon atoms (preferably 1 to 10, more preferably 1 to 4). From the same viewpoint, the hydrocarbon group in the acrylic ester is preferably an aliphatic hydrocarbon. Therefore, the acrylic ester is particularly preferably an alkyl acrylate, and more preferably n-butyl acrylate or 2-ethylhexyl acrylate.

[0040] The acrylic monomer constituting the acrylic ester polymer block (b1) may contain an acrylic monomer other than the acrylic ester having a hydrocarbon group optionally containing an alkoxy group. Examples of the other acrylic monomer include acrylic esters having a crosslinkable functional group, such as 2-hydroxyethyl acrylate, glycidyl acrylate, and allyl acrylate; methacrylic esters constituting hard segments; and carboxyl group-containing monomers, such as methacrylic acid and acrylic acid. The monomer components constituting the soft segments may further include other monomers, such as aromatic vinyl compounds; vinyl cyanide monomers, such as acrylonitrile and methacrylonitrile; and olefins. The proportion of the acrylic ester having a hydrocarbon group optionally containing an alkoxy group in the acrylic ester polymer block (b1) is preferably 90% by mass or more, more preferably 95% by mass or more, based on 100% by mass of the total amount of the monomer components constituting the acrylic ester polymer block (b1).

[0041] The glass transition temperature of the acrylic acid ester polymer block (b1) is not particularly limited, but is preferably from -100 to 20°C, more preferably from -80 to 0°C, and even more preferably from -60 to -40°C.

[0042] The acrylic monomer constituting the hard segment is preferably a methacrylic acid ester. That is, the polymer block of the hard segment is preferably a methacrylic acid ester polymer block (b2). Examples of the methacrylic acid ester include methacrylic acid esters having a hydrocarbon group that may have an alkoxy group (particularly, methacrylic acid alkyl esters that may have an alkoxy group), such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, and 2-methoxyethyl methacrylate. The hydrocarbon group in the methacrylic acid ester may be any of an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which two or more of these are bonded. The acrylic monomer may be used alone or in combination of two or more.

[0043] As the acrylic monomer constituting the methacrylic acid ester polymer block (b2), from the viewpoint of obtaining a molded article with superior impact resistance and heat resistance, a methacrylic acid ester having a hydrocarbon group with 1 to 22 carbon atoms (preferably 1 to 10, more preferably 1 to 4 carbon atoms) is preferred. From the same viewpoint, the hydrocarbon group in the methacrylic acid ester is preferably an aliphatic hydrocarbon. Therefore, as the methacrylic acid ester, alkyl methacrylates are particularly preferred, with methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, and isobornyl methacrylate being more preferred, and methyl methacrylate is particularly preferred.

[0044] The acrylic monomer constituting the methacrylic acid ester polymer block (b2) may contain an acrylic monomer other than the methacrylic acid ester having a hydrocarbon group optionally containing an alkoxy group. Examples of the other acrylic monomer include methacrylic acid esters having a crosslinkable functional group, such as 2-hydroxyethyl methacrylate, glycidyl methacrylate, and allyl methacrylate; acrylic acid esters constituting soft segments; and carboxyl group-containing monomers, such as methacrylic acid and acrylic acid. The monomer components constituting the methacrylic acid ester polymer block (b2) may further include other monomers, such as aromatic vinyl compounds; vinyl cyanide monomers, such as acrylonitrile and methacrylonitrile; and olefins. The proportion of the methacrylic acid ester having a hydrocarbon group optionally containing an alkoxy group in the methacrylic acid ester polymer block (b2) is preferably 90% by mass or more, more preferably 95% by mass or more, based on 100% by mass of the total amount of the monomer components constituting the methacrylic acid ester polymer block (b2).

[0045] The glass transition temperature of the methacrylic acid ester polymer block (b2) is not particularly limited, but is preferably from 30 to 180°C, more preferably from 60 to 160°C, and even more preferably from 100 to 120°C.

[0046] The acrylic block copolymer (B) may have a polymer block (b3) other than the acrylic acid ester polymer block (b1) and the methacrylic acid ester polymer block (b2). The other polymer block is composed of a monomer component other than an acrylic acid ester and a methacrylic acid ester. Examples of monomers constituting the other polymer block include α-olefins such as ethylene, propylene, 1-butene, isobutylene, and 1-octene; conjugated dienes such as butadiene, isoprene, and myrcene; aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, and m-methylstyrene; vinyl acetate, vinylpyridine, acrylonitrile, methacrylonitrile, vinyl ketone, vinyl chloride, vinylidene chloride, vinylidene fluoride, acrylamide, methacrylamide, ε-caprolactone, and valerolactone.

[0047] The bonding form of each polymer block constituting the acrylic block copolymer (B) is not particularly limited, and examples thereof include linear, branched, radial, etc. Examples of the bonding form include linear structures such as a {(b1)-(b2)}n structure, a {(b1)-(b2)}n-(b1) structure, a (b2)-{(b1)-(b2)}n structure, a (b2)-{(b1)-(b2)}n-(b3) structure, and a (b3)-(b2)-{(b1)-(b2)}n-(b3) structure; and a {(b1)-(b2)}nZ structure (n is a natural number in each case, and Z represents a coupling agent residue). From the viewpoint of achieving better dispersibility of the graft copolymer (A) and other thermoplastic resins (C) in the resin composition for plating, a linear structure is preferred, and it is more preferable to use a triblock copolymer in which methacrylic acid ester polymer blocks (b2) are bonded to both ends of an acrylic acid ester polymer block (b1).

[0048] The weight-average molecular weight of the acrylic block copolymer (B) is preferably 10,000 to 200,000, more preferably 15,000 to 150,000. When the weight-average molecular weight of the acrylic block copolymer (B) is 10,000 or more, the melt viscosity is appropriate, the melt-kneadability with the graft copolymer (A) and other thermoplastic resins (C) is good, and the dispersibility of the thermoplastic resin in the molded article is improved. When the weight-average molecular weight is 200,000 or less, the increase in melt viscosity is suppressed, melt fracture during melt molding is prevented, and the appearance of the molded article can be improved. The weight-average molecular weight of each of the acrylic acid ester polymer block (b1) and the methacrylic acid polymer block (b2) in the acrylic block copolymer (B) is preferably 2,000 to 100,000, more preferably 5,000 to 80,000.

[0049] The total content of the acrylic ester polymer blocks (b1) in the acrylic block copolymer (B) is preferably 35 to 85% by mass, more preferably 40 to 80% by mass, and even more preferably 45 to 75% by mass, based on 100% by mass of the total amount of the acrylic block copolymer (B). A content of 35% by mass or more improves the flowability and flexibility of the molded product. A content of 85% by mass or less makes it possible to further reduce the occurrence of sticking in the resin composition for plating. From the same viewpoint, the total content of the methacrylic ester polymer blocks (b2) in the acrylic block copolymer (B) is preferably 15 to 65% by mass, more preferably 20 to 60% by mass, and even more preferably 25 to 55% by mass, based on 100% by mass of the total amount of the acrylic block copolymer (B).

[0050] The total content of the acrylic acid ester polymer block (b1) and the methacrylic acid ester polymer block (b2) in the acrylic block copolymer (B) is preferably 60% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, based on 100% by mass of the total amount of the acrylic block copolymer (B).

[0051] The molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the acrylic block copolymer (B) is preferably 1.01 or more and less than 1.50, more preferably 1.01 to 1.35, and even more preferably 1.01 to 1.20. When the molecular weight distribution is within the above range, the molding processability when the resin composition for plating use is melt-molded becomes more stable.

[0052] The Shore hardness (Type A) of the acrylic block copolymer (B) is preferably 10 to 99, more preferably 20 to 98, and even more preferably 40 to 97. The Shore hardness (Type D) of the acrylic block copolymer (B) is preferably 60 or less (for example, more than 0 and 60 or less), more preferably 5 to 55, and even more preferably 10 to 50. When the Shore hardness is within the above range, the resin composition for plating has better fluidity. The Shore hardness is a value measured in accordance with ISO 7619-1.

[0053] The melt flow rate (MFR) of the acrylic block copolymer (B) at 190°C is preferably 1 to 50 g / 10 min, more preferably 1.5 to 40 g / 10 min, and even more preferably 10 to 30 g / 10 min. The MFR of the acrylic block copolymer (B) at 230°C is preferably 30 g / 10 min or more (e.g., 30 to 600 g / 10 min), more preferably 100 g / 10 min or more (e.g., 100 to 500 g / 10 min), and even more preferably 200 g / 10 min or more (e.g., 200 to 400 g / 10 min). When the MFR is within the above range, the resin composition for plating has better fluidity and the molded article has better processability. The MFR is a value measured at a pressure of 2.16 kg according to ISO 1133.

[0054] The acrylic block copolymer (B) may have a functional group such as a hydroxyl group, a carboxyl group, an acid anhydride group, or an amino group in the molecular chain or at the molecular chain terminal, if necessary.

[0055] (Other thermoplastic resins (C)) The other thermoplastic resin (C) is not particularly limited, and known or commonly used thermoplastic resins can be used. Examples of the other thermoplastic resin (C) include aromatic vinyl resins; acrylic resins such as polymethyl methacrylate resin; polycarbonate resins; polyester resins such as polybutylene terephthalate resin and polyethylene terephthalate resin; polyamide resins; biodegradable resins such as polylactic acid resin; and engineering plastics such as (modified) polyphenylene ether resins, polyoxymethylene resins, polysulfone resins, polyarylate resins, polyphenylene resins, and thermoplastic polyurethane resins. Only one type of other thermoplastic resin (C) may be used, or two or more types may be used.

[0056] Of the other thermoplastic resins (C), aromatic vinyl resins and polycarbonate resins are preferred from the viewpoint of providing molded articles with superior impact resistance.

[0057] The aromatic vinyl resin contains a structural unit derived from an aromatic vinyl monomer. The aromatic vinyl monomer is preferably a styrene monomer. That is, the aromatic vinyl resin is preferably a styrene resin. Examples of the styrene monomer include styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, p-isobutylstyrene, pt-butylstyrene, bromostyrene, and chloromethylstyrene. Among these, styrene and α-methylstyrene are preferred. The aromatic vinyl monomer may be used alone or in combination of two or more.

[0058] The aromatic vinyl resin may contain, in addition to the aromatic vinyl monomer, a structural unit derived from another monomer copolymerizable with the aromatic vinyl monomer. Examples of the other monomer include those exemplified and explained as other monomers that can constitute the graft copolymer (A). The other monomers may be used singly or in combination of two or more.

[0059] The monomer components constituting the aromatic vinyl resin preferably contain a vinyl cyanide monomer as the other monomer. Examples of the vinyl cyanide monomer include those exemplified and explained as vinyl cyanide monomers that can constitute the graft copolymer (A) described above. That is, the aromatic vinyl resin is preferably a copolymer (C1) of an aromatic vinyl monomer and a vinyl cyanide monomer (aromatic vinyl-vinyl cyanide copolymer).

[0060] The monomer components constituting the copolymer (C1) may contain other monomers copolymerizable with the aromatic vinyl monomer and the vinyl cyanide monomer. Examples of such other monomers include those exemplified and explained above as other monomers that can constitute the graft copolymer (A). The above other monomers may be used singly or in combination of two or more.

[0061] The content of structural units derived from aromatic vinyl monomers in copolymer (C1) is preferably 50 to 90% by mass, more preferably 60 to 80% by mass, based on 100% by mass of the total amount of copolymer (C1). The content of structural units derived from vinyl cyanide monomers in copolymer (C1) is preferably 10 to 50% by mass, more preferably 20 to 40% by mass, based on 100% by mass of the total amount of copolymer (C1).

[0062] Specific examples of the aromatic vinyl resin include styrene polymer (PS resin), styrene-acrylonitrile copolymer (AS resin), α-methylstyrene-acrylonitrile copolymer (αMS-ACN resin), methyl methacrylate-styrene copolymer (MS resin), methyl methacrylate-acrylonitrile-styrene copolymer (MAS resin), styrene-N-phenylmaleimide copolymer (S-NPMI resin), and styrene-N-phenylmaleimide-acrylonitrile copolymer (SA-NPMI resin).

[0063] The reduced viscosity of the aromatic vinyl resin is not particularly limited, but is preferably 0.2 to 1.5 dL / g, more preferably 0.3 to 1.0 dL / g, from the viewpoint of achieving a better balance of physical properties such as flowability and impact resistance of molded articles. The reduced viscosity can be determined by dissolving the aromatic vinyl resin in N,N-dimethylformamide to prepare a solution with a concentration of 0.4 g / 100 ml, and measuring the flow time at 30°C using a Cannon-Fenske viscometer.

[0064] Examples of polycarbonate resins include polymers obtained by the phosgene method, in which various dihydroxydiaryl compounds are reacted with phosgene, or by the transesterification method, in which a dihydroxydiaryl compound is reacted with a carbonate ester such as diphenyl carbonate.Specific examples of polycarbonate resins include polycarbonate resins produced from 2,2-bis(4-hydroxyphenyl)propane and bisphenol A.

[0065] Examples of the dihydroxydiaryl compound include, in addition to bisphenol A, bis(hydroxyaryl)alkanes such as bis(4-hydroxydiphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)diphenylmethane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, and 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane; Examples of suitable dihydroxydiaryl compounds include bis(hydroxyaryl)cycloalkanes such as 1,1-bis(4-hydroxyphenyl)cyclopentane and 1,1-bis(4-hydroxyphenyl)cyclohexane, dihydroxydiaryl ethers such as 4,4'-dihydroxydiphenyl ether and 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, dihydroxydiaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfone, and dihydroxydiaryl sulfones such as 4,4'-dihydroxydiphenyl sulfone. The dihydroxydiaryl compounds may be used singly or in combination. In addition to the dihydroxydiaryl compounds, the polycarbonate resin may also contain piperazine, dipiperidyl hydroquinone, resorcinol, 4,4'-dihydroxydiphenyls, and the like.

[0066] Furthermore, the dihydroxydiaryl compounds may be used in combination with the following trivalent or higher phenolic compounds: Examples of trivalent or higher phenolic compounds include phloroglucin, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)heptene, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)heptane, 1,3,5-tri-(4-hydroxyphenyl)benzene, 1,1,1-tri-(4-hydroxyphenyl)ethane, and 2,2-bis-[4,4-bis(4-hydroxyphenyl)cyclohexyl]propane.

[0067] The weight average molecular weight of the polycarbonate resin is, for example, 10,000 to 80,000, and preferably 15,000 to 60,000. The weight average molecular weight can be measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0068] The plating resin composition of the present invention may also contain hindered amine light stabilizers, hindered phenols, sulfur-containing organic compounds, phosphorus-containing organic compounds, and other antioxidants, phenolic and acrylate heat stabilizers, benzoate, benzotriazole, benzophenone, and salicylate UV absorbers, organonickel lubricants and higher fatty acid amides, plasticizers such as phosphate esters, halogen-containing compounds such as polybromophenyl ether, tetrabromobisphenol-A, brominated epoxy oligomers, and brominated compounds, phosphorus-containing compounds, flame retardants and auxiliary flame retardants such as antimony trioxide, odor masking agents, pigments such as carbon black and titanium oxide, and dyes. Furthermore, reinforcing agents and fillers such as talc, calcium carbonate, aluminum hydroxide, glass fiber, glass flakes, glass beads, glass wool, carbon fiber, and metal fiber may also be added.

[0069] The total content of the graft copolymer (A) and the other thermoplastic resin (C) in the resin composition for plating use of the present invention is 51 to 99.5 mass%, preferably 70 to 99 mass%, and more preferably 80 to 98.5 mass%, based on 100 mass% of the total of the graft copolymer (A), the acrylic block copolymer (B), and the other thermoplastic resin (C). When the resin composition for plating use of the present invention does not contain the other thermoplastic resin (C), the above content is the content of the graft copolymer (A) based on 100 mass% of the total of the graft copolymer (A) and the acrylic block copolymer (B).

[0070] The content of the acrylic block copolymer (B) in the resin composition for plating use of the present invention is 0.5 to 49% by mass, preferably 1 to 30% by mass, and more preferably 1.5 to 20% by mass, based on 100% by mass of the total of the graft copolymer (A), the acrylic block copolymer (B), and the other thermoplastic resin (C). When the resin composition for plating use of the present invention does not contain the other thermoplastic resin (C), the content above refers to the content of the acrylic block copolymer (B) based on 100% by mass of the total of the graft copolymer (A) and the acrylic block copolymer (B).

[0071] The content of the graft copolymer (A) in the resin composition for plating use of the present invention is preferably 1 to 60% by mass, more preferably 5 to 55% by mass, and even more preferably 10 to 50% by mass, based on 100% by mass of the total amount of the resin composition for plating use of the present invention. When the content is 1% by mass or more, the effects of incorporating the graft copolymer (A) are easily obtained, and the physical properties such as impact resistance of the molded product are more excellent. When the content is 60% by mass or less, it is possible to incorporate a sufficient amount of the other thermoplastic resin (C), and the effects of incorporating the other thermoplastic resin (C) are more easily obtained.

[0072] The content of the other thermoplastic resin (C) in the resin composition for plating use of the present invention is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, based on 100% by mass of the total amount of the resin composition for plating use of the present invention. When the content is 90% by mass or less, the effects of blending the graft copolymer (A) are easily obtained, and the physical properties such as impact resistance of the molded product are more excellent. The lower limit of the content is, for example, 10% by mass, and may be 30%, 50%, or 60% by mass.

[0073] The content of the rubber polymer in the resin composition for plating of the present invention is preferably 7 to 20 mass %, more preferably 8 to 18 mass %, even more preferably 10 to 15 mass %, and particularly preferably 11 to 14 mass %, relative to 100 mass % of the total of the graft copolymer (A), the acrylic block copolymer (B), and the other thermoplastic resin (C). By adjusting the content within the above range, the balance between plating deposition property and plating adhesion strength can be improved.

[0074] In the resin composition for plating use of the present invention, the total content of the aromatic vinyl monomer and the vinyl cyanide monomer constituting the graft copolymer (A) and the other thermoplastic resin (C) (e.g., copolymer (C1)) is preferably 20 to 73 mass %, more preferably 30 to 65 mass %, and even more preferably 36 to 59 mass %, based on 100 mass % of the total of the graft copolymer (A), the acrylic block copolymer (B), and the other thermoplastic resin (C). When the content is within the above range, the molded article will have excellent adhesion strength to the plating and excellent plating deposition.

[0075] The total content of the graft copolymer (A), acrylic block copolymer (B), and other thermoplastic resin (C) in the resin composition for plating use of the present invention is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, relative to 100% by mass of the total amount of the resin composition for plating use of the present invention. When the content is 50% by mass or more, the effects of the present invention are further improved.

[0076] The notched Charpy impact value of the resin composition for plating of the present invention in accordance with ISO test method 179 (test piece thickness: 4 mm, measurement temperature: 23°C) is 20 kJ / m 2 More preferably, 30 kJ / m or more 2 More preferably, 50 kJ / m 2 The Charpy impact value is 20kJ / m 2 If it is above this level, the impact resistance of the molded article will be superior.

[0077] The melt volume flow rate (MVR) of the plating resin composition of the present invention at 220°C and a load of 98.07 N according to ISO test method 1133 is 2 to 30 cm 3 / 10 minutes is preferable, and 4 to 29 cm is more preferable. 3 / 10 minutes, more preferably 8 to 27 cm 3 When the MVR is within the above range, the adhesive strength to the plating of the molded article is excellent, and the flowability is also excellent.

[0078] The deflection temperature under load of the resin composition for plating of the present invention at a load of 1.8 MPa, as measured in accordance with ISO test method 75, is preferably 75° C. or higher, more preferably 80° C. or higher, even more preferably 82° C. or higher, and particularly preferably 85° C. or higher. When the deflection temperature under load is 75° C. or higher, the molded article has excellent adhesion strength to plating and is also excellent in heat resistance.

[0079] The resin composition for plating use of the present invention can be obtained by mixing the above-mentioned various resins and, if necessary, additives, followed by melt-kneading. For the mixing, a known or conventional kneading machine usually used for mixing resins can be used, such as a roll, a Banbury mixer, an extruder, or a kneader.

[0080] The resin composition for plating obtained in this manner can be molded by injection molding, extrusion molding, compression molding, injection compression molding, blow molding, etc. to produce a resin molded product (molded product). The surface of the molded product can be plated to obtain a plated molded product. The plating can be performed by a known plating method, for example, under the same plating conditions as those for ordinary ABS resin.

[0081] The plating adhesion strength of the plated molded article obtained by plating the above-mentioned resin molded article, as measured in accordance with JIS H8630, is preferably 9 N / cm or more, more preferably 10 N / cm or more, and even more preferably 12 N / cm or more. The resin composition for plating of the present invention has excellent adhesion strength to the plating of the molded article, and therefore can achieve the above-mentioned plating adhesion strength.

[0082] The plating adhesion strength was measured, for example, by molding a resin composition for plating using an injection molding machine to produce a resin molded product having a thickness of 3 mm, and then subjecting the resulting resin molded product to general treatments such as degreasing, etching, adding a catalyst, and washing with water. The resin molded product was then electrolessly plated (nickel plating solution mainly consisting of nickel sulfate, sodium hypophosphite, and sodium citrate, at 50°C for 8 minutes), washed with water, and electrolytic copper plating (room temperature for 2 hours, current density 3 A / dm 2 Measurement can be performed on plated molded products obtained by performing a plating process (film thickness 50 μm). [Example]

[0083] The present invention will be described in detail below using examples, but the present invention is not limited to these examples. In the examples, parts and percentages are based on mass.

[0084] Examples and Comparative Examples The various materials shown in Table 1 were mixed in the blending ratios shown in Table 1, and then melt-kneaded and pelletized in a φ26 mm twin-screw extruder set at a cylinder temperature of 250°C, with a main screw rotation speed of 400 rpm and a discharge rate of 20 kg / hr, to produce pellets (resin composition for plating). The various materials used in the examples and comparative examples were prepared as follows.

[0085] Graft copolymer (A) A glass reactor was charged with 60 parts by weight of coagulated, agglomerated styrene-butadiene rubber latex (5% styrene, 95% butadiene, mass average particle diameter 440 nm) in solids, stirring was initiated, and nitrogen purge was performed. After nitrogen purge, the temperature inside the reactor was raised to 65°C. When it reached 65°C, an aqueous solution containing 0.06 parts by weight of glucose, 0.03 parts by weight of anhydrous sodium pyrophosphate, and 0.001 parts by weight of ferrous sulfate dissolved in 10 parts by weight of deionized water was added, and the temperature was then raised to 70°C. Subsequently, a mixture of 10 parts by weight of acrylonitrile, 30 parts by weight of styrene, 0.3 parts by weight of tertiary dodecyl mercaptan, and 0.1 parts by weight of t-butyl hydroperoxide, and an emulsifier aqueous solution containing 1.0 parts by weight of potassium oleate (solids equivalent) dissolved in 20 parts by weight of deionized water were continuously added dropwise over 4 hours. After the dropwise addition, the mixture was maintained for 3 hours to obtain a graft copolymer latex. The resulting mixture was salted out, dehydrated, and dried to obtain a powder of graft copolymer (A). The graft ratio of the resulting graft copolymer (A) was 42% by mass, and the reduced viscosity of the acetone-soluble portion was 0.28 dL / g. The mass-average particle size of the aggregated and enlarged styrene-butadiene rubber latex was determined as follows. The samples were stained with osmium tetroxide (OsO4), dried, and then photographed using a transmission electron microscope. The area of ​​800 rubber particles was measured using an image analysis processor (model: Asahi Kasei Corporation, "IP-1000PC"), and their equivalent circle diameters were calculated to calculate the mass-average particle diameter.

[0086] Acrylic block copolymer (B1) Product name: "Clarity LA4285", manufactured by Kuraray Co., Ltd.

[0087] Acrylic block copolymer (B2) Product name: "Clarity LA2250", manufactured by Kuraray Co., Ltd.

[0088] Copolymer (C11) A copolymer consisting of 75 parts by mass of styrene and 25 parts by mass of acrylonitrile was obtained by a known bulk polymerization method. The copolymer obtained by the above method had a reduced viscosity of 0.50 dL / g.

[0089] Copolymer (C12) A copolymer consisting of 75 parts by mass of styrene and 25 parts by mass of acrylonitrile was obtained by a known bulk polymerization method. The copolymer obtained by the above method had a reduced viscosity of 0.60 dL / g.

[0090] Polycarbonate resin (C21) A polycarbonate resin made from phosgene and bisphenol A with a viscosity average molecular weight of 20,500.

[0091] Polycarbonate resin (C22) A polycarbonate resin made from phosgene and bisphenol A with a viscosity average molecular weight of 19,000.

[0092] [Measurement and Evaluation] The resin compositions for plating obtained in the examples and comparative examples were evaluated as follows, and the results are shown in Table 1.

[0093] (1) Melt Volume Flow Rate (MVR) The pellets obtained in each of the Examples and Comparative Examples were used to measure the melt volume-flow rate at 220°C and a load of 98.07 N in accordance with ISO test method 1133. Unit: cm 3 / 10 minutes

[0094] (2) Charpy impact strength (NC) Using the pellets obtained in each example and comparative example, various test pieces were molded in accordance with ISO test method 294, and the notched Charpy impact values ​​of 4 mm thick test pieces were measured in accordance with ISO test method 179. Unit: kJ / m 2

[0095] (3) Heat deflection temperature (HDT) Using the pellets obtained in each example and comparative example, various test pieces were molded in accordance with ISO test method 294, and the deflection temperature under load of 1.8 MPa was measured in accordance with ISO test method 75. Unit: °C

[0096] (4) Plating adhesion strength The pellets obtained in each example and comparative example were molded into flat plate molded products for plating (55 x 90 x 3 mm) using an injection molding machine, and plated using the method described below. The adhesion strength of the deposited plating film was then measured in accordance with JIS H8630, with cuts made in the metal film of the plated molded product at 1 cm intervals reaching the substrate, and the metal film was peeled off in the perpendicular direction, and the strength was expressed as the stress (N / cm). <Plating process> The above-mentioned plate molded product for plating was degreased by immersion in a degreasing solution (aqueous surfactant solution) at 55°C for 3 minutes. After degreasing, the plate was rinsed with water at room temperature for 1 minute and then immersed in a surface preparation solution (aqueous sulfuric acid solution - aqueous surfactant solution) for 3 minutes for surface preparation. After surface preparation, the plate was immersed in an etching solution (400 g / L chromic anhydride, 400 g / L sulfuric acid) at 68°C for 15 minutes for etching. After etching, the plate was rinsed with water at room temperature for 1 minute and then immersed in a neutralizing solution (aqueous hydrochloric acid solution) at room temperature for 2 minutes for neutralization. After neutralization, the plate was rinsed with water at room temperature for 1 minute and then immersed in a catalyst application solution (aqueous palladium chloride - stannous chloride - hydrochloric acid solution) at 35°C for 5 minutes for catalyst application. After catalyst application, the plate was rinsed with water at room temperature for 1 minute and then immersed in an accelerator solution (aqueous hydrochloric acid solution) at 40°C for 5 minutes for activation. After activation, the plate was rinsed with water at room temperature for 1 minute, and then immersed in an electroless plating solution (nickel plating solution mainly consisting of nickel sulfate, sodium hypophosphite, and sodium citrate) at 50°C for 8 minutes to perform electroless nickel plating. After rinsing the plate with water at room temperature for 1 minute, it was immersed in an electroless copper plating bath at 25°C for 2 hours with a current density of 3 A / dm 2 A current of 1000 kJ / s was applied to deposit a 50 μm thick electrolytic copper plating film on the plate. After electrolytic copper plating, the plate was rinsed with room temperature water for 1 minute, and then dried at room temperature. After drying, the plate was aged at 80°C for 2 hours and then left overnight.

[0097] (5) Measurement of graft rate The graft copolymer (A) was fractionated using acetone to determine the weight ratio of the acetone insoluble portion, which was 42% by mass.

[0098] [Table 1]

[0099] As shown in Table 1, the resin composition for plating of the present invention was evaluated as having excellent fluidity, adhesion strength to plating on molded articles, and also excellent impact resistance of molded articles (Examples). On the other hand, when the acrylic block copolymer (B) was not included (Comparative Examples 1 and 3 to 5), the adhesion strength to plating on molded articles was poor. Furthermore, Comparative Example 1 was slightly inferior in fluidity and impact resistance of molded articles compared to Example 1, which also contained copolymer (C11). Furthermore, Comparative Example 3 was inferior in fluidity compared to Examples 2 and 3, which also contained copolymer (C11) and polycarbonate resin (C21). When the blending amount of acrylic block copolymer (B) was high (Comparative Example 2), plating could not be applied to molded articles. Furthermore, Comparative Examples 4 and 5 were significantly inferior in impact resistance of molded articles compared to Examples 4 to 6, which also contained copolymer (C12) and polycarbonate resin (C21). [Industrial Applicability]

[0100] The resin composition for plating use of the present invention has excellent flowability and provides molded articles with excellent plating adhesion strength and impact resistance, and can therefore be used in a variety of applications to meet market needs, such as for vehicle interior and exterior parts.

Claims

1. The composition contains a graft copolymer (A) obtained by graft polymerizing a rubber polymer with a monomer component containing an aromatic vinyl monomer and a vinyl cyanide monomer, an acrylic block copolymer (B), and another thermoplastic resin (C), The other thermoplastic resin (C) includes a copolymer (C1) of an aromatic vinyl monomer and a vinyl cyanide monomer, the total content of the aromatic vinyl monomer and the vinyl cyanide monomer constituting the graft copolymer (A) and the other thermoplastic resin (C) is 20 to 73 mass% relative to 100 mass% of the total of the graft copolymer (A), the acrylic block copolymer (B), and the other thermoplastic resin (C); the total content of the graft copolymer (A) and the other thermoplastic resin (C) is 90 to 99.5 mass%, and the content of the acrylic block copolymer (B) is 0.5 to 10 mass%, relative to 100 mass% of the total of the graft copolymer (A), the acrylic block copolymer (B), and the other thermoplastic resin (C); In the graft copolymer (A), the content of the vinyl cyanide monomer is 10 to 50% by mass relative to 100% by mass of the total amount of the monomer components, the content of the structural units derived from vinyl cyanide monomers in the copolymer (C1) is 10 to 50% by mass, relative to 100% by mass of the total amount of the copolymer (C1); The melt volume flow rate (MVR) at 220°C and a load of 98.07N conforming to ISO test method 1133 is 2 to 30 cm ３ / 10 minutes.

2. 2. The resin composition for plating use according to claim 1, wherein the rubbery polymer comprises a conjugated diene rubber.

3. 3. The resin composition for plating according to claim 1, wherein the content of the rubber polymer is 7 to 20% by mass relative to 100% by mass of the total of the graft copolymer (A), the acrylic block copolymer (B), and the other thermoplastic resin (C).

4. 4. The resin composition for plating use according to claim 1, wherein the acrylic block copolymer (B) has a Shore hardness (Type A) of 10 to 99.

5. 5. The resin composition for plating use according to claim 1, wherein the acrylic block copolymer (B) has a melt flow rate at 230° C. of 30 to 600 g / 10 min.

6. 6. The resin composition for plating use according to claim 1, wherein the acrylic block copolymer (B) is a block copolymer of an acrylic acid ester polymer block and a methacrylic acid ester polymer block.

7. The resin composition for plating use according to any one of claims 1 to 6, wherein the other thermoplastic resin (C) comprises a polycarbonate resin.

8. A plated molded article obtained by plating a molded article made of the resin composition for plating use according to any one of claims 1 to 7.

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