Resin composition and resin molded article

Abstract

The present invention relates to a resin composition containing a maleimide copolymer (A), a graft copolymer (B), and a vinyl copolymer (C). Based on 100 parts by mass of the total amount of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C), the total content of aromatic vinyl monomer units is 55 to 65 parts by mass, the total content of vinyl cyanide monomer units is 15 to 27 parts by mass, the total content of maleimide monomer units is 3 to 15 parts by mass, the total content of conjugated diene monomer units is 10 to 20 parts by mass, and the melt mass flow rate under the conditions of 220 °C and 98 N load is 3 to 23 g / 10 min.

Description

Technical Field

[0001] The present invention relates to a resin composition. Background Art

[0002] Heretofore, as a thermoplastic resin having excellent heat resistance, copolymers formed from aromatic vinyl monomers, vinyl cyanide monomers, and maleimide monomers have been studied (for example, Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 3-205411 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In the case of a molded article formed of a thermoplastic resin, when a coating containing an organic solvent is applied to the molded article, there are cases where cracks or the like are generated in the molded article, or an appearance defect occurs because a good coating surface cannot be formed.

[0008] Therefore, an object of the present invention is to provide a resin composition capable of forming a molded article having excellent coating resistance and a resin molded article containing the resin composition.

[0009] Means for Solving the Problems

[0010] The inventors of the present application found that the penetration of a solvent into minute cracks on the surface of a molded article and the swelling and breakage of a coating film caused by the solvent during drying of the coating film are one of the causes of appearance defects on the coating surface, and thus completed the present invention.

[0011] One aspect of the present invention relates to a resin composition comprising: a maleimide copolymer (A) having an aromatic vinyl monomer unit, a vinyl cyanide monomer unit, and a maleimide monomer unit; a graft copolymer (B) obtained by graft-polymerizing at least one selected from the group consisting of an aromatic vinyl monomer and a vinyl cyanide monomer onto a polymer (b) having a conjugated diene monomer unit; and a vinyl copolymer (C) having an aromatic vinyl monomer unit and a vinyl cyanide monomer unit and not having a maleimide monomer unit. Based on 100 parts by mass of the total amount of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C), the total content of the aromatic vinyl monomer units is 55.0 to 65.0 parts by mass, the total content of the vinyl cyanide monomer units is 15.0 to 27.0 parts by mass, the total content of the maleimide monomer units is 3.0 to 15.0 parts by mass, and the total content of the conjugated diene monomer units is 10.0 to 20.0 parts by mass. The resin composition has a melt mass flow rate of 3 to 23 g / 10 min under the conditions of 220°C and a load of 98 N, and the melt mass flow rate is measured by the method described in JIS K 7210.

[0012] For such a resin composition, by combining a specific maleimide copolymer (A), a graft copolymer (B), and a vinyl copolymer (C) such that the contents of the respective monomer units are within the above ranges and the melt flow rate is within the above range, high fluidity at high temperatures, excellent heat resistance, and chemical resistance are simultaneously achieved. For the above resin composition, when it is made to flow at a high temperature to form a resin molded article, strain is not likely to remain in the resin molded article, and thus the generation of cracks caused by such strain can be sufficiently suppressed. Therefore, according to the above resin composition, poor appearance of the painted surface due to cracks can be sufficiently suppressed, and a resin molded article having excellent paint resistance can be achieved.

[0013] In one embodiment, the maleimide copolymer (A) may include a maleimide copolymer (A-1) having a maleimide monomer unit content of 20.0% by mass or more.

[0014] In one embodiment, the content of the maleimide copolymer (A-1) may be 5 to 40% by mass based on the total amount of the resin composition.

[0015] In one embodiment, the graft copolymer (B) may include a graft copolymer (B-1) having a conjugated diene monomer unit content of 45.0 to 65.0% by mass.

[0016] In one embodiment, the content of the graft copolymer (B-1) may be 16 to 34% by mass based on the total amount of the resin composition.

[0017] In one embodiment, the vinyl copolymer (C) may include a vinyl copolymer (C-1) in which the total content of the aromatic vinyl monomer unit and the vinyl cyanide monomer unit is 80.0% by mass or more.

[0018] In one embodiment, the content of the vinyl copolymer (C-1) may be 40 to 74% by mass based on the total amount of the resin composition.

[0019] The gel fraction of the resin composition according to one embodiment may be 15 to 25% by mass based on the total amount of the resin composition.

[0020] Another aspect of the present invention relates to a resin molded article containing the above resin composition.

[0021] Advantages of the Invention

[0022] According to the present invention, there can be provided a resin composition capable of forming a molded article having excellent paint resistance and a resin molded article containing the resin composition. Detailed Description of Embodiments

[0023] Hereinafter, preferred embodiments of the present invention will be described in detail.

[0024] The resin composition of the present embodiment contains: a maleimide copolymer (A) having an aromatic vinyl monomer unit, a vinyl cyanide monomer unit, and a maleimide monomer unit; a graft copolymer (B) obtained by graft-polymerizing at least one selected from the group consisting of an aromatic vinyl monomer and a vinyl cyanide monomer onto a polymer (b) having a conjugated diene monomer unit; and a vinyl copolymer (C) having an aromatic vinyl monomer unit and a vinyl cyanide monomer unit and not having a maleimide monomer unit.

[0025] In addition, in the resin composition of the present embodiment, based on 100 parts by mass of the total amount of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C), the total content of the aromatic vinyl monomer units (i) is 55.0 to 65.0 parts by mass, the total content of the vinyl cyanide monomer units (ii) is 15.0 to 27.0 parts by mass, the total content of the maleimide monomer units (iii) is 3.0 to 15.0 parts by mass, and the total content of the conjugated diene monomer units (iv) is 10.0 to 20.0 parts by mass.

[0026] Furthermore, for the resin composition of the present embodiment, the melt mass-flow rate measured by the method described in JIS K 7210 under the conditions of 220°C and a load of 98 N is 3 to 23 g / 10 min.

[0027] The resin composition of the present embodiment combines a specific maleimide copolymer (A), a graft copolymer (B), and a vinyl copolymer (C) such that the contents of the respective monomer units are within the above ranges and the melt flow rate is within the above range. Thus, the resin composition of the present embodiment simultaneously achieves high fluidity at high temperatures, and excellent heat resistance and chemical resistance. For the resin composition of the present embodiment, when it is caused to flow at a high temperature to form a resin molded article, strain is not likely to remain in the resin molded article, and thus generation of cracks caused by such strain can be sufficiently suppressed. Therefore, according to the resin composition of the present embodiment, appearance defects of the painted surface caused by cracks can be sufficiently suppressed, and a resin molded article having excellent paint resistance can be achieved.

[0028] Hereinafter, each monomer unit included in the resin composition of the present embodiment will be described in detail.

[0029] <Aromatic vinyl monomer unit (i)>

[0030] The aromatic vinyl monomer unit (i) represents a structural unit (repeating unit) derived from an aromatic vinyl monomer. The aromatic vinyl monomer may be a monomer having a carbon-carbon double bond and at least one aromatic ring directly bonded to the double bond, and is preferably a monomer having a group represented by -C(R)=CH2 (R is a hydrogen atom or a methyl group) bonded to the aromatic ring.

[0031] As the aromatic ring included in the aromatic vinyl monomer unit (i), a benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred.

[0032] Examples of the aromatic vinyl monomer include:

[0033] A styrene monomer selected from the group consisting of styrene and styrene derivatives in which a part of the hydrogen atoms of styrene are substituted with substituents,

[0034] A vinylnaphthalene monomer selected from the group consisting of 1-vinylnaphthalene, 2-vinylnaphthalene, and vinylnaphthalene derivatives in which a part of the hydrogen atoms thereof are substituted with substituents, and the like.

[0035] Examples of the substituents of each derivative include a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, preferably a fluorine atom or a chlorine atom), an alkyl group (e.g., an alkyl group having 1 to 16 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms), etc. These groups may further have substituents (e.g., the above-mentioned substituents).

[0036] As the styrene monomer, a compound selected from the group consisting of styrene, α-methylstyrene, p-methylstyrene, ethylstyrene, tert-butylstyrene, chlorostyrene, and dichlorostyrene is preferred, a compound selected from the group consisting of styrene and α-methylstyrene is more preferred, and styrene is further preferred.

[0037] As the vinylnaphthalene monomer, a compound selected from the group consisting of 1-vinylnaphthalene and 2-vinylnaphthalene is preferred, and 2-vinylnaphthalene is more preferred.

[0038] As the aromatic vinyl monomer, a styrene monomer is preferred. That is, as the aromatic vinyl monomer unit (i), a styrene monomer unit is preferred.

[0039] In the resin composition of the present embodiment, based on 100 parts by mass of the total amount of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C), the content of the aromatic vinyl monomer unit (i) is 55.0 parts by mass or more, preferably 56.0 parts by mass or more, more preferably 57.0 parts by mass or more. Thus, there is a tendency that the fluidity of the resin composition at high temperature is further improved, and a resin molded product having more excellent paint resistance is easily obtained.

[0040] In addition, based on 100 parts by mass of the total amount of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C), the content of the aromatic vinyl monomer unit (i) is 65.0 parts by mass or less, preferably 64.0 parts by mass or less. Thus, there is a tendency that a resin molded product having more excellent impact resistance is easily obtained. That is, based on 100 parts by mass of the total amount of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C), the content of the aromatic vinyl monomer unit (i) can be, for example, 55.0 to 65.0 parts by mass, 55.0 to 64.0 parts by mass, 56.0 to 65.0 parts by mass, 56.0 to 64.0 parts by mass, 57.0 to 65.0 parts by mass, or 57.0 to 64.0 parts by mass.

[0041] <Vinyl cyanide monomer unit (ii)>

[0042] The vinyl cyanide-based monomer unit (ii) represents a structural unit (repeating unit) derived from a vinyl cyanide-based monomer. The vinyl cyanide-based monomer can be a monomer having a carbon-carbon double bond and at least one cyano group directly bonded to the double bond.

[0043] Examples of the vinyl cyanide-based monomer include acrylonitrile, methacrylonitrile, fumaronitrile, α-chloracrylonitrile, and the like.

[0044] As the vinyl cyanide-based monomer, acrylonitrile is preferred. That is, as the vinyl cyanide-based monomer unit (ii), an acrylonitrile unit is preferred.

[0045] In the resin composition of the present embodiment, based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the content of the vinyl cyanide-based monomer unit (ii) is 15.0 parts by mass or more, preferably 16.0 parts by mass or more, more preferably 17.0 parts by mass or more, and further preferably 18.0 parts by mass or more. Thus, there is a tendency that the fluidity of the resin composition at high temperatures is further improved, and a resin molded article having more excellent paint resistance is easily obtained.

[0046] In addition, based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the content of the vinyl cyanide-based monomer unit (ii) is 27.0 parts by mass or less, preferably 26.0 parts by mass or less, and more preferably 25.0 parts by mass or less. Thus, there is a tendency that a resin molded article having more excellent heat resistance is easily obtained. That is, based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the content of the vinyl cyanide-based monomer unit (ii) can be, for example, 15.0 to 27.0 parts by mass, 15.0 to 26.0 parts by mass, 15.0 to 25.0 parts by mass, 16.0 to 27.0 parts by mass, 16.0 to 26.0 parts by mass, 16.0 to 25.0 parts by mass, 17.0 to 27.0 parts by mass, 17.0 to 26.0 parts by mass, 17.0 to 25.0 parts by mass, 18.0 to 27.0 parts by mass, 18.0 to 26.0 parts by mass, or 18.0 to 25.0 parts by mass.

[0047] <Maleimide-based monomer unit (iii)>

[0048] The maleimide-based monomer unit (iii) represents a structural unit (repeating unit) derived from a maleimide-based monomer. The maleimide-based monomer can be, for example, a monomer having at least one group represented by the following formula (iii-1). It should be noted that the maleimide-based monomer unit (iii) does not necessarily have to be formed from a maleimide-based monomer. For example, it can also be formed by modifying an unsaturated dicarboxylic acid-based monomer unit described later with ammonia or a primary amine.

[0049] [Chemical formula 1]

[0050]

[0051] Examples of the maleimide-based monomer include maleimide and N-substituted maleimide (i.e., maleimide having a substituent on the nitrogen atom). Examples of the substituent on the nitrogen atom of the N-substituted maleimide include an alkyl group (e.g., an alkyl group having 1 to 18 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms), a cycloalkyl group (e.g., a cycloalkyl group having 3 to 9 carbon atoms, preferably a cycloalkyl group having 4 to 8 carbon atoms, more preferably a cycloalkyl group having 5 to 7 carbon atoms), an aryl group (e.g., an aryl group having 6 to 10 carbon atoms, preferably a phenyl group), etc. These groups can further have substituents (e.g., the above-mentioned substituents, a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, preferably a fluorine atom or a chlorine atom), an alkoxy group (e.g., an alkoxy group having 1 to 18 carbon atoms, preferably an alkoxy group having 1 to 8 carbon atoms, more preferably an alkoxy group having 1 to 4 carbon atoms), etc.).

[0052] Examples of the N-substituted maleimide include:

[0053] N-alkyl maleimides such as N-methyl maleimide, N-ethyl maleimide, N-n-butyl maleimide, N-n-octyl maleimide;

[0054] N-cycloalkyl maleimides such as N-cyclohexyl maleimide;

[0055] N-aryl maleimides such as N-phenyl maleimide, N-(4-methoxyphenyl) maleimide; and so on.

[0056] As the maleimide-based monomer, N-substituted maleimide is preferred, N-aryl maleimide is more preferred, and N-phenyl maleimide is further preferred. That is, as the maleimide-based monomer unit (iii), N-substituted maleimide unit is preferred, N-aryl maleimide unit is more preferred, and N-phenyl maleimide unit is further preferred.

[0057] In the resin composition of the present embodiment, based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the content of the maleimide-based monomer unit (iii) is 3.0 parts by mass or more, preferably 3.5 parts by mass or more. As a result, there is a tendency for the heat resistance to be further improved.

[0058] In addition, based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the content of the maleimide-based monomer unit (iii) is 15.0 parts by mass or less, preferably 13.0 parts by mass or less, more preferably 11.0 parts by mass or less, and further preferably 9.0 parts by mass or less. As a result, there is a tendency for the fluidity of the resin composition at high temperatures to be further improved, and it is easier to obtain a resin molded product with more excellent paint resistance. That is, based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the content of the maleimide-based monomer unit (iii) can be, for example, 3.0 to 15.0 parts by mass, 3.0 to 13.0 parts by mass, 3.0 to 11.0 parts by mass, 3.0 to 9.0 parts by mass, 3.5 to 15.0 parts by mass, 3.5 to 13.0 parts by mass, 3.5 to 11.0 parts by mass, or 3.5 to 9.0 parts by mass.

[0059] <Conjugated diene monomer unit (iv)>

[0060] The conjugated diene monomer unit (iv) represents a structural unit (repeating unit) derived from a conjugated diene monomer. The conjugated diene monomer can be a monomer having a conjugated diene, preferably a hydrocarbon having a conjugated diene.

[0061] The conjugated diene monomer unit (iv) may or may not have a carbon-carbon double bond. For example, the conjugated diene monomer unit (iv) can be a monomer unit having a carbon-carbon double bond formed by the polymerization reaction of a conjugated diene monomer, or a monomer unit not having a carbon-carbon double bond formed by the reaction of this monomer unit with other monomers.

[0062] The number of carbon atoms of the conjugated diene monomer can be, for example, 4 to 5.

[0063] Examples of the conjugated diene monomer include butadiene, isoprene, etc. As the conjugated diene monomer, butadiene is more preferred.

[0064] In the resin composition of the present embodiment, based on 100 parts by mass of the total amount of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C), the content of the conjugated diene monomer unit (iv) is 10.0 parts by mass or more, preferably 11.0 parts by mass or more, and may also be 12.0 parts by mass or more, 13.0 parts by mass or more, or 14.0 parts by mass or more. Thus, there is a tendency that the strength of the resin composition is further improved, and a resin molded article having more excellent impact resistance can be easily obtained.

[0065] In addition, based on 100 parts by mass of the total amount of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C), the content of the conjugated diene monomer unit (iv) is 20.0 parts by mass or less, preferably 19.0 parts by mass or less, more preferably 18.0 parts by mass or less, and may also be 17.0 parts by mass or less, 16.0 parts by mass or less, or 15.0 parts by mass or less. Thus, there is a tendency that the fluidity of the resin composition at high temperatures is further improved, and a resin molded article having more excellent paint resistance can be easily obtained. That is, based on 100 parts by mass of the total amount of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C), the content of the conjugated diene monomer unit (iv) may be 10.0 to 20.0 parts by mass, 10.0 to 19.0 parts by mass, 10.0 to 18.0 parts by mass, 10.0 to 17.0 parts by mass, 10.0 to 16.0 parts by mass, 10.0 to 15.0 parts by mass, 11.0 to 20.0 parts by mass, 11.0 to 19.0 parts by mass, 11.0 to 18.0 parts by mass, 11.0 to 17.0 parts by mass, 11.0 to 16.0 parts by mass, 11.0 to 15.0 parts by mass, 12.0 to 20.0 parts by mass, 12.0 to 19.0 parts by mass, 12.0 to 18.0 parts by mass, 12.0 to 17.0 parts by mass, 12.0 to 16.0 parts by mass, 12.0 to 15.0 parts by mass, 13.0 to 20.0 parts by mass, 13.0 to 19.0 parts by mass, 13.0 to 18.0 parts by mass, 13.0 to 17.0 parts by mass, 13.0 to 16.0 parts by mass, 13.0 to 15.0 parts by mass, 14.0 to 20.0 parts by mass, 14.0 to 19.0 parts by mass, 14.0 to 18.0 parts by mass, 14.0 to 17.0 parts by mass, 14.0 to 16.0 parts by mass, or 14.0 to 15.0 parts by mass.

[0066] The resin composition of the present embodiment may further have an unsaturated dicarboxylic acid monomer unit (v).

[0067] <Unsaturated dicarboxylic acid monomer unit (v)>

[0068] The unsaturated dicarboxylic acid-based monomer unit (v) represents a structural unit (repeating unit) derived from an unsaturated dicarboxylic acid-based monomer. Examples of the unsaturated dicarboxylic acid-based monomer include unsaturated dicarboxylic acids and their anhydrides (unsaturated dicarboxylic anhydrides).

[0069] Examples of the unsaturated dicarboxylic acid include maleic acid, itaconic acid, etc. Examples of the unsaturated dicarboxylic anhydride include maleic anhydride, itaconic anhydride, etc.

[0070] In the resin composition of the present embodiment, based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the content of the unsaturated dicarboxylic acid-based monomer unit (v) can be, for example, 15.0 parts by mass or less, preferably 10.0 parts by mass or less, more preferably 5.0 parts by mass or less, further preferably 3.0 parts by mass or less, and even more preferably 1.0 parts by mass or less.

[0071] The resin composition of the present embodiment may not have the unsaturated dicarboxylic acid-based monomer unit (v). In this case, it can be said that the content of the unsaturated dicarboxylic acid-based monomer unit (v) in the resin composition of the present embodiment is 0 part by mass.

[0072] When the resin composition of the present embodiment has the unsaturated dicarboxylic acid-based monomer unit (v), based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the content of the unsaturated dicarboxylic acid-based monomer unit (v) can be, for example, 0.01 part by mass or more, preferably 0.05 part by mass or more, and more preferably 0.1 part by mass or more. Thus, it is easy to obtain a resin molded product having excellent adhesion to the coating film. That is, based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the content of the unsaturated dicarboxylic acid-based monomer unit (v) can be, for example, 0 to 15.0 parts by mass, 0 to 10.0 parts by mass, 0 to 5.0 parts by mass, 0 to 3.0 parts by mass, 0 to 1.0 parts by mass, 0.01 to 15.0 parts by mass, 0.01 to 10.0 parts by mass, 0.01 to 5.0 parts by mass, 0.01 to 3.0 parts by mass, 0.01 to 1.0 parts by mass, 0.05 to 15.0 parts by mass, 0.05 to 10.0 parts by mass, 0.05 to 5.0 parts by mass, 0.05 to 3.0 parts by mass, 0.05 to 1.0 parts by mass, 0.1 to 15.0 parts by mass, 0.1 to 10.0 parts by mass, 0.1 to 5.0 parts by mass, 0.1 to 3.0 parts by mass, or 0.1 to 1.0 parts by mass.

[0073] The resin composition of the present embodiment may further have other monomer units (x) other than the above (i) to (v).

[0074] As other monomer units (x), for example, methyl (meth)acrylate units, ethyl (meth)acrylate units, butyl (meth)acrylate units, (meth)acrylic acid units, (meth)acrylamide units, etc. can be cited.

[0075] In the resin composition of the present embodiment, based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the content of the other monomer units (x) can be, for example, 15.0 parts by mass or less, preferably 10.0 parts by mass or less, more preferably 5.0 parts by mass or less, can also be 3.0 parts by mass or less, 2.0 parts by mass or less, or 1.0 parts by mass or less, and can also be 0 parts by mass.

[0076] That is, in the resin composition of the present embodiment, based on 100 parts by mass of the total amount of the maleimide-based copolymer (A), the graft copolymer (B), and the vinyl-based copolymer (C), the total content of the above monomer units (i) to (v) can be, for example, 85.0 parts by mass or more, preferably 90.0 parts by mass or more, more preferably 95.0 parts by mass or more, can also be 97.0 parts by mass or more, 98.0 parts by mass or more, or 99.0 parts by mass or more, and can also be 100 parts by mass. Thereby, the above effects can be more significantly exhibited.

[0077] The content of each monomer unit can be determined by 13 the C-NMR method using the following apparatus and measurement conditions.

[0078] Apparatus name: JNM-ECX series FT-NMR (manufactured by JEOL Ltd.)

[0079] Solvent: deuterated chloroform

[0080] Concentration: 2.5 mass%

[0081] Temperature: 27 °C

[0082] Number of accumulations: 8000 times

[0083] Next, each copolymer contained in the resin composition of the present embodiment will be described in detail.

[0084] <Maleimide-based copolymer (A)>

[0085] The maleimide-based copolymer (A) is a copolymer having an aromatic vinyl-based monomer unit (i), a cyanated vinyl-based monomer unit (ii), and a maleimide-based monomer unit (iii).

[0086] The glass transition temperature (Tg1) of the maleimide copolymer (A) is, for example, 153°C or higher, preferably 157°C or higher, and more preferably 163°C or higher. Thereby, it is easy to obtain a resin molded article having more excellent heat resistance. In addition, the glass transition temperature (Tg1) of the maleimide copolymer (A) is, for example, 193°C or lower, preferably 188°C or lower, and more preferably 183°C or lower. Thereby, the dispersibility in the resin composition is improved, and it is easier to prepare a uniform resin composition. That is, the glass transition temperature (Tg1) of the maleimide copolymer (A) can be, for example, 153 to 193°C, 153 to 188°C, 153 to 183°C, 157 to 193°C, 157 to 188°C, 157 to 183°C, 163 to 193°C, 163 to 188°C, or 163 to 183°C.

[0087] It should be noted that in this specification, the glass transition temperature (Tg1) refers to the extrapolated glass transition start temperature (Tig) of the maleimide copolymer measured according to JIS K-7121 using the following apparatus and measurement conditions.

[0088] Apparatus name: Differential scanning calorimeter Robot DSC6200 (manufactured by Seiko Instruments Inc.)

[0089] Temperature increase rate: 10°C / minute

[0090] The weight average molecular weight of the maleimide copolymer (A) is, for example, 50,000 or higher, preferably 70,000 or higher, and more preferably 80,000 or higher. Thereby, it is easy to obtain a resin molded article having more excellent impact resistance. In addition, the weight average molecular weight of the maleimide copolymer (A) is, for example, 170,000 or lower, preferably 160,000 or lower, and more preferably 150,000 or lower. Thereby, there is a tendency that the fluidity of the resin composition at high temperature is further improved, and it is easy to obtain a resin molded article having more excellent paint resistance. That is, the weight average molecular weight of the maleimide copolymer (A) can be, for example, 50,000 to 170,000, 50,000 to 160,000, 50,000 to 150,000, 70,000 to 170,000, 70,000 to 160,000, 70,000 to 150,000, 80,000 to 170,000, 80,000 to 160,000, or 80,000 to 150,000.

[0091] It should be noted that in this specification, the weight average molecular weight is a value converted to polystyrene measured by gel permeation chromatography (GPC), and can be measured under the following conditions.

[0092] Measurement name: SYSTEM-21 Shodex (manufactured by Showa Denko K.K.)

[0093] Column: Three PL gel MIXED-B (manufactured by Polymer Laboratories) are connected in series

[0094] Temperature: 40 °C

[0095] Detection: Differential refractive index

[0096] Solvent: Tetrahydrofuran

[0097] Concentration: 2% by mass

[0098] Standard curve: Prepared using standard polystyrene (PS) (manufactured by Polymer Laboratories)

[0099] The content of each monomer unit in the maleimide copolymer (A) can be appropriately changed in a manner that satisfies a suitable content range in the resin composition, in a manner that satisfies suitable properties of the maleimide copolymer (A), and in a manner that satisfies suitable properties of the resin composition.

[0100] The content of the aromatic vinyl monomer unit (i) in the maleimide copolymer (A) can be, for example, 40.0% by mass or more, preferably 43.0% by mass or more, more preferably 45.0% by mass or more. In addition, the content of the aromatic vinyl monomer unit (i) in the maleimide copolymer (A) can be, for example, 58.0% by mass or less, preferably 55.0% by mass or less, more preferably 52.0% by mass or less. That is, the content of the aromatic vinyl monomer unit (i) in the maleimide copolymer (A) can be, for example, 40.0 to 58.0% by mass, 40.0 to 55.0% by mass, 40.0 to 52.0% by mass, 43.0 to 58.0% by mass, 43.0 to 55.0% by mass, 43.0 to 52.0% by mass, 45.0 to 58.0% by mass, 45.0 to 55.0% by mass, or 45.0 to 52.0% by mass.

[0101] The content of the cyanated vinyl monomer unit (ii) in the maleimide copolymer (A) can be, for example, 5.0% by mass or more, preferably 6.0% by mass or more, more preferably 7.0% by mass or more. In addition, the content of the cyanated vinyl monomer unit (ii) in the maleimide copolymer (A) can be, for example, 20.0% by mass or less, preferably 18.0% by mass or less, more preferably 15.0% by mass or less. That is, the content of the cyanated vinyl monomer unit (ii) in the maleimide copolymer (A) can be, for example, 5.0 to 20.0% by mass, 5.0 to 18.0% by mass, 5.0 to 15.0% by mass, 6.0 to 20.0% by mass, 6.0 to 18.0% by mass, 6.0 to 15.0% by mass, 7.0 to 20.0% by mass, 7.0 to 18.0% by mass, or 7.0 to 15.0% by mass.

[0102] The content of the maleimide monomer unit (iii) in the maleimide copolymer (A) can be, for example, 35.0% by mass or more, preferably 37.0% by mass or more, more preferably 39.0% by mass or more. In addition, the content of the maleimide monomer unit (iii) in the maleimide copolymer (A) can be, for example, 50.0% by mass or less, preferably 47.0% by mass or less, more preferably 44.0% by mass or less. That is, the content of the maleimide monomer unit (iii) in the maleimide copolymer (A) can be, for example, 35.0 to 50.0% by mass, 35.0 to 47.0% by mass, 35.0 to 44.0% by mass, 37.0 to 50.0% by mass, 37.0 to 47.0% by mass, 37.0 to 44.0% by mass, 39.0 to 50.0% by mass, 39.0 to 47.0% by mass, or 39.0 to 44.0% by mass.

[0103] The maleimide copolymer (A) may further have an unsaturated dicarboxylic acid monomer unit (v).

[0104] The content of the unsaturated dicarboxylic acid monomer unit (v) in the maleimide copolymer (A) can be, for example, 10.0% by mass or less, preferably 5.0% by mass or less, more preferably 2.0% by mass or less. In addition, when the maleimide copolymer (A) has the unsaturated dicarboxylic acid monomer unit (v), the content of the unsaturated dicarboxylic acid monomer unit (v) can be, for example, 0.5% by mass or more, and can also be 1.0% by mass or more. That is, the content of the unsaturated dicarboxylic acid monomer unit (v) in the maleimide copolymer (A) can be, for example, 0 to 10.0% by mass, 0 to 5.0% by mass, 0 to 2.0% by mass, 0.5 to 10.0% by mass, 0.5 to 5.0% by mass, 0.5 to 2.0% by mass, 1.0 to 10.0% by mass, 1.0 to 5.0% by mass, or 1.0 to 2.0% by mass.

[0105] In the maleimide-based copolymer, the ratio (v / i) of the unsaturated dicarboxylic acid-based monomer unit (v) to the maleimide-based monomer unit (i) can be, for example, 0.25 or less, preferably 0.14 or less, and more preferably 0.06 or less in terms of molar ratio. In addition, the above ratio (v / i) can be, for example, 0.01 or more, and can also be 0.02 or more. That is, the ratio (v / i) of the unsaturated dicarboxylic acid-based monomer unit (v) to the maleimide-based monomer unit (i) can be, for example, 0 to 0.25, 0 to 0.14, 0 to 0.06, 0.01 to 0.25, 0.01 to 0.14, 0.01 to 0.06, 0.02 to 0.25, 0.02 to 0.14, or 0.02 to 0.06 in terms of molar ratio.

[0106] The maleimide-based copolymer (A) may further have other monomer units (x). Examples of the other monomer units (x) possessed by the maleimide-based copolymer (A) include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylic acid, (meth)acrylamide, and the like.

[0107] The content of the other monomer units (x) in the maleimide-based copolymer (A) can be, for example, 15.0% by mass or less, preferably 10.0% by mass or less, and more preferably 5.0% by mass or less. In addition, when the maleimide-based copolymer (A) has other monomer units (x), the content of the other monomer units (x) can be, for example, 0.5% by mass or more, and can also be 1.0% by mass or more. That is, the content of the other monomer units (x) in the maleimide-based copolymer (A) can be, for example, 0 to 15.0% by mass, 0 to 10.0% by mass, 0 to 5.0% by mass, 0.5 to 15.0% by mass, 0.5 to 10.0% by mass, 0.5 to 5.0% by mass, 1.0 to 15.0% by mass, 1.0 to 10.0% by mass, or 1.0 to 5.0% by mass.

[0108] The maleimide-based copolymer (A) preferably contains a maleimide-based copolymer (A-1) in which the content of the maleimide-based monomer unit (iii) is 20.0% by mass or more. The content of the maleimide-based monomer unit (iii) in the maleimide-based copolymer (A-1) is preferably 25.0% by mass or more, and more preferably 30.0% by mass or more.

[0109] The content of the maleimide copolymer (A) is, for example, 5% by mass or more, preferably 7% by mass or more, more preferably 9% by mass or more, based on the total amount of the resin composition. Thus, it is easy to obtain a resin molded product having more excellent heat resistance. In addition, the content of the maleimide copolymer (A) is, for example, 40% by mass or less, preferably 28% by mass or less, more preferably 23% by mass or less, based on the total amount of the resin composition. Thus, there is a tendency that the fluidity of the resin composition at high temperatures is further improved and it is easy to obtain a resin molded product having more excellent paint resistance. That is, the content of the maleimide copolymer (A) is, for example, 5 to 40% by mass, 5 to 28% by mass, 5 to 23% by mass, 7 to 40% by mass, 7 to 28% by mass, 7 to 23% by mass, 9 to 40% by mass, 9 to 28% by mass, or 9 to 23% by mass, based on the total amount of the resin composition.

[0110] The content of the maleimide copolymer (A-1) is, for example, 5% by mass or more, preferably 7% by mass or more, more preferably 9% by mass or more, based on the total amount of the resin composition. Thus, it is easy to obtain a resin molded product having more excellent heat resistance. In addition, the content of the maleimide copolymer (A-1) is, for example, 40% by mass or less, preferably 28% by mass or less, more preferably 23% by mass or less, based on the total amount of the resin composition. Thus, there is a tendency that the fluidity of the resin composition at high temperatures is further improved and it is easy to obtain a resin molded product having more excellent paint resistance. That is, the content of the maleimide copolymer (A-1) is, for example, 5 to 40% by mass, 5 to 28% by mass, 5 to 23% by mass, 7 to 40% by mass, 7 to 28% by mass, 7 to 23% by mass, 9 to 40% by mass, 9 to 28% by mass, or 9 to 23% by mass, based on the total amount of the resin composition.

[0111] The method for producing the maleimide copolymer (A) is not particularly limited. The maleimide copolymer (A) can be produced, for example, by subjecting a monomer component containing an aromatic vinyl monomer, a vinyl cyanide monomer, and a maleimide monomer to a polymerization reaction. In addition, the maleimide copolymer (A) can also be produced, for example, as follows: A monomer component containing an aromatic vinyl monomer, a vinyl cyanide monomer, and an unsaturated dicarboxylic acid monomer is subjected to a polymerization reaction to form a polymer (A') having an aromatic vinyl monomer unit (i), a vinyl cyanide monomer unit (ii), and an unsaturated dicarboxylic acid monomer unit (v), and at least a part of the unsaturated dicarboxylic acid monomer unit (v) in the polymer (A') is modified into a maleimide monomer unit (iii) for production.

[0112] The method of the polymerization reaction is not particularly limited. For example, known polymerization methods such as bulk polymerization, solution polymerization, and suspension polymerization can be applied.

[0113] The polymerization reaction can be carried out by the reaction of the monomer component with a polymerization initiator. As the polymerization initiator, as long as it is an initiator that can initiate the polymerization reaction of the monomer component, it is not particularly limited, and known polymerization initiators can be used. As the polymerization initiator, for example, organic peroxides, azo compounds, etc. can be exemplified.

[0114] As the organic peroxide, for example, peroxyketal-based such as 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 2,2-bis(4,4-di-tert-butylperoxycyclohexyl)propane, 1,1-bis(tert-butylperoxy)cyclohexane, etc., peroxide ester-based such as tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisopropyl monocarbonate, tert-butyl peroxyacetate, etc., hydroperoxide-based such as dicumyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, etc. can be cited.

[0115] As the azo compound, for example, 2,2-azobisisobutyronitrile, 2,2-azobis(2,4-dimethylvaleronitrile), 2,2-azobis(2-methylbutyronitrile), etc. can be cited.

[0116] In the polymerization reaction, a chain transfer agent or a molecular weight regulator can be used. As the chain transfer agent or the molecular weight regulator, known substances can be used without particular limitation. For example, mercaptans such as tert-dodecyl mercaptan and n-dodecyl mercaptan, terpinolene, α-methylstyrene dimer, etc. can be used.

[0117] The modification of the unsaturated dicarboxylic acid-based monomer unit (v) can be carried out, for example, by the reaction of the polymer (A’) with ammonia and / or a primary amine (hereinafter, also referred to as the modification reaction).

[0118] The reaction temperature of the modification reaction can be, for example, 120°C to 250°C, preferably 150°C to 230°C.

[0119] The modification reaction can be carried out in the presence of a catalyst. As the catalyst, for example, tertiary amines such as trimethylamine and triethylamine are preferred, and trimethylamine is particularly preferred. The amount of the catalyst can be, for example, 0.01 to 2 parts by mass relative to 100 parts by mass of the total amount of ammonia and the primary amine.

[0120] <Graft copolymer (B)>

[0121] The graft copolymer (B) is a copolymer obtained by graft-polymerizing at least one selected from the group consisting of aromatic vinyl monomers and vinyl cyanide monomers onto a polymer (b) having a conjugated diene monomer unit (iv). That is, the graft copolymer has a conjugated diene monomer unit (iv) and at least one selected from the group consisting of an aromatic vinyl monomer unit (i) and a vinyl cyanide monomer unit (ii).

[0122] The glass transition temperature (Tg2) on the low-temperature side of the graft copolymer (B) derived from the polymer (b) is, for example, -40°C or lower, preferably -50°C or lower, and more preferably -70°C or lower. Thereby, it is easy to obtain a resin molded article having more excellent impact resistance in a low-temperature environment.

[0123] The content of each monomer unit in the graft copolymer (B) can be appropriately changed in a manner that satisfies a suitable content range in the resin composition, in a manner that satisfies suitable properties of the graft copolymer (B), and in a manner that satisfies suitable properties of the resin composition.

[0124] The content of the conjugated diene monomer unit (iv) in the graft copolymer (B) can be, for example, 45.0% by mass or more, preferably 47.0% by mass or more, and more preferably 50.0% by mass or more. In addition, the content of the conjugated diene monomer unit (iv) in the graft copolymer (B) can be, for example, 65.0% by mass or less, preferably 63.0% by mass or less, and more preferably 60.0% by mass or less. That is, the content of the conjugated diene monomer unit (iv) in the graft copolymer (B) can be, for example, 45.0 to 65.0% by mass, 45.0 to 63.0% by mass, 45.0 to 60.0% by mass, 47.0 to 65.0% by mass, 47.0 to 63.0% by mass, 47.0 to 60.0% by mass, 50.0 to 65.0% by mass, 50.0 to 63.0% by mass, or 50.0 to 60.0% by mass.

[0125] The total content of the aromatic vinyl monomer unit (i) and the vinyl cyanide monomer unit (ii) in the graft copolymer (B) can be, for example, 35.0% by mass or more, preferably 37.0% by mass or more, more preferably 40.0% by mass or more. In addition, the total content of the aromatic vinyl monomer unit (i) and the vinyl cyanide monomer unit (ii) in the graft copolymer (B) can be, for example, 55.0% by mass or less, preferably 53.0% by mass or less, more preferably 50.0% by mass or less. That is, the total content of the aromatic vinyl monomer unit (i) and the vinyl cyanide monomer unit (ii) in the graft copolymer (B) can be, for example, 35.0 to 55.0% by mass, 35.0 to 53.0% by mass, 35.0 to 50.0% by mass, 37.0 to 55.0% by mass, 37.0 to 53.0% by mass, 37.0 to 50.0% by mass, 40.0 to 55.0% by mass, 40.0 to 53.0% by mass, or 40.0 to 50.0% by mass.

[0126] The content of the aromatic vinyl monomer unit (i) in the graft copolymer (B) can be, for example, 24.0% by mass or more, preferably 25.0% by mass or more, more preferably 27.0% by mass or more. In addition, in this embodiment, the content of the aromatic vinyl monomer unit (i) in the graft copolymer (B) can be, for example, 41.0% by mass or less, preferably 39.0% by mass or less, more preferably 37.0% by mass or less. That is, the content of the aromatic vinyl monomer unit (i) in the graft copolymer (B) can be, for example, 24.0 to 41.0% by mass, 24.0 to 39.0% by mass, 24.0 to 37.0% by mass, 25.0 to 41.0% by mass, 25.0 to 39.0% by mass, 25.0 to 37.0% by mass, 27.0 to 41.0% by mass, 27.0 to 39.0% by mass, or 27.0 to 37.0% by mass.

[0127] The content of the vinyl cyanide monomer unit (ii) in the graft copolymer (B) can be, for example, 9.0% by mass or more, preferably 10.0% by mass or more, more preferably 11.0% by mass or more. In addition, in this embodiment, the content of the vinyl cyanide monomer unit (ii) in the graft copolymer (B) can be, for example, 18.0% by mass or less, preferably 17.0% by mass or less, more preferably 16.0% by mass or less. That is, the content of the vinyl cyanide monomer unit (ii) in the graft copolymer (B) can be, for example, 9.0 to 18.0% by mass, 9.0 to 17.0% by mass, 9.0 to 16.0% by mass, 10.0 to 18.0% by mass, 10.0 to 17.0% by mass, 10.0 to 16.0% by mass, 11.0 to 18.0% by mass, 11.0 to 17.0% by mass, or 11.0 to 16.0% by mass.

[0128] In the graft copolymer (B), the ratio (ii / i) of the content of the vinyl cyanide monomer unit (ii) to the content of the aromatic vinyl monomer unit (i) may be, for example, 0.67 or less, preferably 0.54 or less, more preferably 0.49 or less, by mass ratio. In addition, the above ratio (ii / i) may be, for example, 0.25 or more, and may also be 0.3 or more. That is, the above ratio (ii / i) may be, for example, 0.25 to 0.67, 0.25 to 0.54, 0.25 to 0.49, 0.3 to 0.67, 0.3 to 0.54, or 0.3 to 0.49.

[0129] The graft copolymer (B) may further have other monomer units (y) in addition to the conjugated diene monomer unit (iv), the aromatic vinyl monomer unit (i), and the vinyl cyanide monomer unit (ii).

[0130] Examples of the above monomer units (y) include maleimide monomer units (iii), unsaturated dicarboxylic acid monomer units (v), the above monomer units (x), etc. Among them, (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid butyl ester, (meth)acrylic acid, (meth)acrylamide, etc. are preferred.

[0131] The content of the above monomer units (y) in the graft copolymer (B) may be, for example, 7.0% by mass or less, preferably 5.0% by mass or less, more preferably 3.0% by mass or less. In addition, when the graft copolymer (B) has the above monomer units (y), the content of the above monomer units (y) may be, for example, 0.2% by mass or more, and may also be 0.5% by mass or more. That is, the content of the above monomer units (y) in the graft copolymer (B) may be, for example, 0 to 7.0% by mass, 0 to 5.0% by mass, 0 to 3.0% by mass, 0.2 to 7.0% by mass, 0.2 to 5.0% by mass, 0.2 to 3.0% by mass, 0.5 to 7.0% by mass, 0.5 to 5.0% by mass, or 0.5 to 3.0% by mass.

[0132] The graft copolymer (B) preferably contains a graft copolymer (B-1) in which the content of the conjugated diene monomer unit (iv) is 45.0 to 65.0% by mass.

[0133] The content of the graft copolymer (B) is, for example, 16% by mass or more, preferably 18% by mass or more, more preferably 20% by mass or more, based on the total amount of the resin composition. Thus, it is easy to obtain a resin molded article having more excellent impact resistance. In addition, the content of the graft copolymer (B) is, for example, 34% by mass or less, preferably 32% by mass or less, more preferably 30% by mass or less, based on the total amount of the resin composition. Thus, there is a tendency that the fluidity of the resin composition at high temperature is further improved and it is easy to obtain a resin molded article having more excellent paint resistance. That is, the content of the graft copolymer (B) is, for example, 16 to 34% by mass, 16 to 32% by mass, 16 to 30% by mass, 18 to 34% by mass, 18 to 32% by mass, 18 to 30% by mass, 20 to 34% by mass, 20 to 32% by mass or 20 to 30% by mass, based on the total amount of the resin composition.

[0134] The content of the graft copolymer (B-1) is, for example, 16% by mass or more, preferably 18% by mass or more, more preferably 20% by mass or more, based on the total amount of the resin composition. Thus, it is easy to obtain a resin molded article having more excellent impact resistance. In addition, the content of the graft copolymer (B-1) is, for example, 34% by mass or less, preferably 32% by mass or less, more preferably 30% by mass or less, based on the total amount of the resin composition. Thus, there is a tendency that the fluidity of the resin composition at high temperature is further improved and it is easy to obtain a resin molded article having more excellent paint resistance. That is, the content of the graft copolymer (B-1) is, for example, 16 to 34% by mass, 16 to 32% by mass, 16 to 30% by mass, 18 to 34% by mass, 18 to 32% by mass, 18 to 30% by mass, 20 to 34% by mass, 20 to 32% by mass or 20 to 30% by mass, based on the total amount of the resin composition.

[0135] (Polymer (b))

[0136] Polymer (b) is a polymer having a conjugated diene monomer unit (iv). Polymer (b) may be a homopolymer of a conjugated diene monomer or a copolymer of a conjugated diene monomer and other monomers.

[0137] The content of the conjugated diene monomer unit (iv) in polymer (b) is, for example, 60.0% by mass or more, preferably 80.0% by mass or more, more preferably 90.0% by mass or more, and may also be 100% by mass.

[0138] Polymer (b) may further have other monomer units (y') other than the conjugated diene monomer unit (iv).

[0139] Examples of the monomer unit (y') in the polymer (b) include aromatic vinyl monomer units (i), vinyl cyanide monomer units (ii), and the above monomer unit (y). Among them, styrene and the like are preferred.

[0140] The content of the above monomer unit (y') in the polymer (b) can be, for example, 40.0% by mass or less, preferably 20.0% by mass or less, more preferably 10.0% by mass or less. In addition, when the polymer (b) has the above monomer unit (y'), the content of the above monomer unit (y') can be, for example, 1.0% by mass or more, and can also be 2.0% by mass or more. That is, the content of the above monomer unit (y') in the polymer (b) can be, for example, 0 to 40.0% by mass, 0 to 20.0% by mass, 0 to 10.0% by mass, 1.0 to 40.0% by mass, 1.0 to 20.0% by mass, 1.0 to 10.0% by mass, 2.0 to 40.0% by mass, 2.0 to 20.0% by mass, or 2.0 to 10.0% by mass.

[0141] The method for producing the polymer (b) is not particularly limited. For example, it can be produced by subjecting a monomer component containing a conjugated diene monomer to a polymerization reaction.

[0142] The polymerization method for carrying out the polymerization reaction for producing the polymer (b) is not particularly limited. For example, known polymerization methods such as emulsion polymerization and solution polymerization can be applied.

[0143] The polymerization reaction can be carried out by the reaction of a monomer component and a polymerization initiator. As the polymerization initiator, as long as it is an initiator capable of initiating the polymerization reaction of the monomer component, there is no particular limitation, and known polymerization initiators can be used.

[0144] Examples of the polymerization initiator include peroxides (e.g., potassium persulfate, cumene hydroperoxide, etc.), redox catalysts composed of a peroxide and a reducing agent that promotes its decomposition, azo compounds, organolithium initiators, catalysts composed of a transition metal compound and an organoaluminum; and so on.

[0145] In the polymerization reaction, a chain transfer agent or a molecular weight regulator can be used. As the chain transfer agent or the molecular weight regulator, known substances (such as the above substances) can be used without particular limitation.

[0146] (Graft polymerization)

[0147] The graft copolymer (B) can be produced by graft-polymerizing at least one selected from the group consisting of aromatic vinyl monomers and vinyl cyanide monomers onto the polymer (b).

[0148] Graft polymerization can be carried out by subjecting a monomer component containing a polymer (b) and at least one selected from the group consisting of aromatic vinyl monomers and vinyl cyanide monomers to a polymerization reaction.

[0149] The polymerization method in graft polymerization is not particularly limited. For example, known polymerization methods such as emulsion polymerization, bulk polymerization, solution polymerization, etc. can be applied.

[0150] Graft polymerization can be carried out by the reaction of the polymer (b), the monomer component, and a polymerization initiator. As the polymerization initiator, as long as it can initiate the reaction between the polymer (b) and the monomer component, there is no particular limitation, and known polymerization initiators can be used.

[0151] As the polymerization initiator, for example, the above-mentioned organic peroxides, the above-mentioned azo compounds, redox catalysts composed of a combination of an organic peroxide and a reducing agent that promotes its decomposition, etc. can be exemplified.

[0152] In the polymerization reaction, a chain transfer agent or a molecular weight regulator can be used. As the chain transfer agent or the molecular weight regulator, known substances (such as the above-mentioned substances) can be used without particular limitation.

[0153] In graft polymerization, all of the carbon-carbon double bonds possessed by the conjugated diene monomer units (iv) in the polymer (b) may react with the monomer component, or only a part thereof may react with the monomer component (that is, carbon-carbon double bonds remain in the graft copolymer (B)).

[0154] In the graft copolymer (B), the conjugated diene monomer units (iv) may include monomer units (iv-1) that do not have a carbon-carbon double bond (that is, monomer units that have reacted with the monomer component in graft polymerization), and monomer units (iv-2) that have a carbon-carbon double bond (that is, monomer units that have not reacted with the monomer component in graft polymerization).

[0155] <Vinyl copolymer (C)>

[0156] The vinyl copolymer (C) is a copolymer having an aromatic vinyl monomer unit (i) and a vinyl cyanide monomer unit (ii), and not having a maleimide monomer unit (iii).

[0157] The glass transition temperature (Tg3) of the vinyl copolymer (C) is, for example, 97°C or higher, preferably 100°C or higher, more preferably 103°C or higher. Thereby, it is easy to obtain a resin molded product with more excellent heat resistance. In addition, the glass transition temperature (Tg3) of the vinyl copolymer (C) is, for example, 115°C or lower, preferably 112°C or lower, more preferably 110°C or lower. Thereby, the fluidity of the resin composition at high temperatures is further improved, and it is easy to obtain a resin molded product with more excellent paint resistance. That is, the glass transition temperature (Tg3) of the vinyl copolymer (C) can be, for example, 97 to 115°C, 97 to 112°C, 97 to 110°C, 100 to 115°C, 100 to 112°C, 100 to 110°C, 103 to 115°C, 103 to 112°C, or 103 to 110°C.

[0158] The weight average molecular weight of the vinyl copolymer (C) is, for example, 50,000 or higher, preferably 70,000 or higher, more preferably 80,000 or higher. Thereby, it is easy to obtain a resin molded product with more excellent impact resistance. In addition, the weight average molecular weight of the vinyl copolymer (C) is, for example, 200,000 or lower, preferably 180,000 or lower, more preferably 160,000 or lower. Thereby, the fluidity of the resin composition at high temperatures is further improved, and it is easy to obtain a resin molded product with more excellent paint resistance. That is, the weight average molecular weight of the vinyl copolymer (C) can be, for example, 50,000 to 200,000, 50,000 to 180,000, 50,000 to 160,000, 70,000 to 200,000, 70,000 to 180,000, 70,000 to 160,000, 80,000 to 200,000, 80,000 to 180,000, or 80,000 to 160,000.

[0159] The content of each monomer unit in the vinyl copolymer (C) can be appropriately changed in a manner that satisfies the appropriate content range in the resin composition, in a manner that satisfies the appropriate properties of the vinyl copolymer (C), and in a manner that satisfies the appropriate properties of the resin composition.

[0160] The content of the aromatic vinyl monomer unit (i) in the vinyl copolymer (C) can be, for example, 60.0% by mass or more, preferably 65.0% by mass or more, more preferably 67.0% by mass or more. In addition, the content of the aromatic vinyl monomer unit (i) in the vinyl copolymer (C) can be, for example, 80.0% by mass or less, preferably 77.0% by mass or less, more preferably 75.0% by mass or less. That is, the content of the aromatic vinyl monomer unit (i) in the vinyl copolymer (C) can be, for example, 60.0 to 80.0% by mass, 60.0 to 77.0% by mass, 60.0 to 75.0% by mass, 65.0 to 80.0% by mass, 65.0 to 77.0% by mass, 65.0 to 75.0% by mass, 67.0 to 80.0% by mass, 67.0 to 77.0% by mass, or 67.0 to 75.0% by mass.

[0161] The content of the vinyl cyanide monomer unit (ii) in the vinyl copolymer (C) can be, for example, 20.0% by mass or more, preferably 23.0% by mass or more, more preferably 25.0% by mass or more. In addition, the content of the vinyl cyanide monomer unit (ii) in the vinyl copolymer (C) can be, for example, 40.0% by mass or less, preferably 35.0% by mass or less, more preferably 33.0% by mass or less. That is, the content of the vinyl cyanide monomer unit (ii) in the vinyl copolymer (C) can be, for example, 20.0 to 40.0% by mass, 20.0 to 35.0% by mass, 20.0 to 33.0% by mass, 23.0 to 40.0% by mass, 23.0 to 35.0% by mass, 23.0 to 33.0% by mass, 25.0 to 40.0% by mass, 25.0 to 35.0% by mass, or 25.0 to 33.0% by mass.

[0162] The vinyl copolymer (C) may further have other monomer units (z) in addition to the aromatic vinyl monomer unit (i) and the vinyl cyanide monomer unit (ii).

[0163] Examples of the monomer unit (z) include a conjugated diene monomer unit (iv), an unsaturated dicarboxylic acid monomer (v), the monomer unit (x), etc. Among them, the monomer unit (x) is preferred, and more preferably a monomer unit selected from the group consisting of a (meth)acrylic acid methyl ester unit, a (meth)acrylic acid ethyl ester unit, a (meth)acrylic acid butyl ester unit, a (meth)acrylic acid unit, and a (meth)acrylamide unit.

[0164] The content of the above monomer unit (z) in the vinyl copolymer (C) may be, for example, 15.0% by mass or less, preferably 10.0% by mass or less, more preferably 5.0% by mass or less. In addition, when the vinyl copolymer (C) has the above monomer unit (z), the content of the above monomer unit (z) may be, for example, 0.5% by mass or more and may also be 1.0% by mass or more. That is, the content of the above monomer unit (z) in the vinyl copolymer (C) may be, for example, 0 to 15.0% by mass, 0 to 10.0% by mass, 0 to 5.0% by mass, 0.5 to 15.0% by mass, 0.5 to 10.0% by mass, 0.5 to 5.0% by mass, 1.0 to 15.0% by mass, 1.0 to 10.0% by mass, or 1.0 to 5.0% by mass.

[0165] The vinyl copolymer (C) preferably contains a vinyl copolymer (C-1) in which the total content of the aromatic vinyl monomer unit (i) and the vinyl cyanide monomer unit (ii) is 80% by mass or more. The total content of the aromatic vinyl monomer unit (i) and the vinyl cyanide monomer unit (ii) in the vinyl copolymer (C-1) is preferably 90.0% by mass or more, more preferably 95.0% by mass or more, and may also be 100% by mass.

[0166] The content of the vinyl copolymer (C) based on the total amount of the resin composition may be, for example, 40% by mass or more, preferably 45% by mass or more, more preferably 55% by mass or more. Thereby, it is easy to obtain a resin molded article with more excellent paint resistance. In addition, the content of the vinyl copolymer (C) based on the total amount of the resin composition may be, for example, 74% by mass or less, preferably 72% by mass or less, more preferably 70% by mass or less. Thereby, the fluidity of the resin composition at high temperature is further improved, and it is easy to obtain a resin molded article with more excellent paint resistance. That is, the content of the vinyl copolymer (C) based on the total amount of the resin composition may be, for example, 40 to 74% by mass, 40 to 72% by mass, 40 to 70% by mass, 45 to 74% by mass, 45 to 72% by mass, 45 to 70% by mass, 55 to 74% by mass, 55 to 72% by mass, or 55 to 70% by mass.

[0167] The content of the vinyl copolymer (C-1) is, for example, 40% by mass or more, preferably 45% by mass or more, more preferably 55% by mass or more, based on the total amount of the resin composition. Thus, it is easy to obtain a resin molded article with more excellent painting resistance. In addition, the content of the vinyl copolymer (C-1) is, for example, 74% by mass or less, preferably 72% by mass or less, more preferably 70% by mass or less, based on the total amount of the resin composition. Thus, the fluidity of the resin composition at high temperatures is further improved, and it is easy to obtain a resin molded article with even more excellent painting resistance. That is, the content of the vinyl copolymer (C-1) is, for example, 40 to 74% by mass, 40 to 72% by mass, 40 to 70% by mass, 45 to 74% by mass, 45 to 72% by mass, 45 to 70% by mass, 55 to 74% by mass, 55 to 72% by mass, or 55 to 70% by mass.

[0168] The method for producing the vinyl copolymer (C) is not particularly limited. The vinyl copolymer (C) can be produced, for example, by subjecting a monomer component containing an aromatic vinyl monomer and a vinyl cyanide monomer to a polymerization reaction.

[0169] The method for the polymerization reaction for producing the vinyl copolymer (C) is not particularly limited. For example, it can be the same method as the polymerization reaction for producing the maleimide copolymer (A).

[0170] In the resin composition of the present embodiment, the total content of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C) is, for example, 90% by mass or more, preferably 95% by mass or more, more preferably 98% by mass or more, and may also be 100% by mass, based on the total amount of the resin composition.

[0171] <Other components>

[0172] The resin composition of the present embodiment may further contain other polymers (X) other than the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C).

[0173] The polymer (X) may be a polymer having at least one selected from the group consisting of an aromatic vinyl monomer unit (i), a vinyl cyanide monomer unit (ii), a maleimide monomer unit (iii), a conjugated diene monomer unit (iv), an unsaturated dicarboxylic acid monomer unit, and the above monomer unit (x), or may be a polymer not having an aromatic vinyl monomer unit (i), a vinyl cyanide monomer unit (ii), a maleimide monomer unit (iii), a conjugated diene monomer unit (iv), an unsaturated dicarboxylic acid monomer unit, and the above monomer unit (x).

[0174] The content of the above-mentioned polymer (X) is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 2% by mass or less, based on the total amount of the resin composition, and may be 0% by mass.

[0175] In addition, the resin composition of the present embodiment may further contain other components other than the above. Examples of the other components include impact-resistant modifiers, fluidity modifiers, hardness modifiers, antioxidants, matting agents, flame retardants, flame retardant aids, antifogging agents, sliding property imparting agents, plasticizers, lubricants, mold release agents, ultraviolet absorbers, light stabilizers, antibacterial agents, antifungal agents, antistatic agents, pigments, dyes, and the like.

[0176] The melt mass flow rate of the resin composition of the present embodiment is 3 g / 10 min or more, preferably 5 g / 10 min or more, more preferably 8 g / 10 min or more, under the conditions of 220°C and a load of 98 N. Such a resin composition has more excellent fluidity at high temperatures, and thus the above-mentioned effects can be more significantly exerted.

[0177] In addition, the above melt flow rate is 23 g / 10 min or less, preferably 21 g / 10 min or less, more preferably 19 g / 10 min or less. According to such a resin composition, a resin molded article having more excellent heat resistance and impact resistance can be obtained. That is, the above melt flow rate can be, for example, 3 to 23 g / 10 min, 3 to 21 g / 10 min, 3 to 19 g / 10 min, 5 to 23 g / 10 min, 5 to 21 g / 10 min, 5 to 19 g / 10 min, 8 to 23 g / 10 min, 8 to 21 g / 10 min, or 8 to 19 g / 10 min.

[0178] The gel fraction of the resin composition of the present embodiment is preferably 15% by mass or more, more preferably 17% by mass or more, further preferably 19% by mass or more, based on the total amount of the resin composition. Thereby, it is easy to obtain a resin molded article having more excellent impact resistance.

[0179] In addition, the gel fraction of the resin composition of the present embodiment is preferably 25% by mass or less, more preferably 24% by mass or less, further preferably 22% by mass or less, based on the total amount of the resin composition. Thereby, the fluidity of the resin composition at high temperatures is further improved, and it is easy to obtain a resin molded article having more excellent paintability. That is, the gel fraction of the resin composition of the present embodiment can be, for example, 15 to 25% by mass, 15 to 24% by mass, 15 to 22% by mass, 17 to 25% by mass, 17 to 24% by mass, 17 to 22% by mass, 19 to 25% by mass, 19 to 24% by mass, or 19 to 22% by mass.

[0180] It should be noted that the gel fraction of the resin composition is measured by the following method.

[0181] <Measurement of Gel Fraction>

[0182] (1) Weigh 1.5 g of the sample precisely in a 100 mL stoppered conical flask. (s)

[0183] (2) Add 30 mL of methyl ethyl ketone (MEK) and let it stand overnight.

[0184] (3) After standing overnight, shake it for 10 minutes using a shaker.

[0185] (4) Weigh precisely a 50 mL centrifuge tube made of SUS. (b)

[0186] (5) Transfer the sample solution to the centrifuge tube, rinse the remaining liquid in the conical flask with MEK and add it to the centrifuge tube.

[0187] (6) Use a centrifuge to centrifuge at 24000 rpm for 40 minutes.

[0188] (7) After centrifugation, take out the centrifuge tube and discard the supernatant. Then, add a small amount of MEK to the centrifuge tube and discard the supernatant.

[0189] (8) Pre-dry the centrifuge tube in a hot air dryer (70 °C - 75 °C) for more than 4 hours.

[0190] (9) After pre-drying, perform vacuum drying using a vacuum dryer (70 °C, 76 cmHg) for more than 15 hours.

[0191] (10) After vacuum drying, cool it to room temperature in a desiccator and perform precise weighing. (a)

[0192] (11) Calculate the gel fraction using the following formula.

[0193] Gel fraction (%) = 100 × (a - b) / s

[0194] [In the formula, a represents the weight after vacuum drying (weight of dried gel + centrifuge tube) (g), b represents the weight of the empty centrifuge tube (g), and s represents the weight of the sample (g)]

[0195] The resin composition of this embodiment can also be mixed with an inorganic material and used in the form of a composite material. As the inorganic material, for example, inorganic filler materials such as glass fiber, talc, mica, heat dissipation materials, electromagnetic wave absorption materials, etc. can be cited. In addition, as the inorganic material, carbon black, titanium oxide, pigments, etc. can also be exemplified.

[0196] The manufacturing method of the resin composition of the present embodiment is not particularly limited. For example, it can be manufactured by mixing the above-mentioned components at a high temperature.

[0197] The temperature during mixing only needs to be a temperature at which the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C) can flow and mix. For example, when the highest glass transition temperature among the glass transition temperatures (Tg1) of the maleimide copolymer (A), the glass transition temperature (Tg2) of the graft copolymer (B), and the glass transition temperature (Tg3) of the vinyl copolymer (C) is set as Tg0, the mixing temperature is preferably Tg0 or higher, more preferably Tg0 + 60°C or higher, and further preferably Tg0 + 100°C or higher. In addition, the mixing temperature can be, for example, Tg0 + 150°C or lower, or can also be Tg0 + 130°C or lower. That is, the mixing temperature can be, for example, Tg0 to Tg0 + 150°C, Tg0 to Tg0 + 130°C, Tg0 + 60°C to Tg0 + 150°C, Tg0 + 60°C to Tg0 + 130°C, Tg0 + 100°C to Tg0 + 150°C, or Tg0 + 100°C to Tg0 + 130°C.

[0198] The mixing method is not particularly limited. For example, it can be appropriately selected from known methods using a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader, etc.

[0199] The resin composition of the present embodiment can be used alone or in the form of a composite material mixed with an inorganic material to manufacture a resin molded article. That is, the resin molded article is manufactured by making the resin composition of the present embodiment flow at a high temperature and performing molding.

[0200] The temperature during molding only needs to be a temperature at which the resin composition can flow and be molded. For example, when the Vicat softening point of the resin composition is set as V1 (°C), the molding temperature is preferably V1 + 100°C or higher, more preferably V1 + 120°C or higher, and further preferably V1 + 130°C or higher.

[0201] In addition, the molding temperature can be, for example, V1 + 170°C or lower, preferably V1 + 160°C or lower, and more preferably V1 + 150°C or lower. Conventionally, if the molding temperature of the resin composition is low, there has been a tendency for strain to remain easily in the molded product, for cracks to be easily generated, and for poor appearance of the painted surface due to such cracks. In addition, if the molding temperature is high, there are concerns about various problems such as the generation of decomposition gases, the deterioration of the hue, and the deformation of the mold. In contrast, the resin composition of the present embodiment has excellent fluidity at high temperatures. Therefore, even if the molding temperature is low, strain is not likely to remain, and the generation of cracks and the poor appearance of the painted surface due to such cracks can be sufficiently suppressed. Therefore, with the resin composition according to the present embodiment, various problems such as the generation of decomposition gases, the deterioration of the hue, and the deformation of the mold can be suppressed, and a resin molded product with excellent paint resistance can be manufactured. That is, the molding temperature can be, for example, V1 + 100°C to V1 + 170°C, V1 + 100°C to V1 + 160°C, V1 + 100°C to V1 + 150°C, V1 + 120°C to V1 + 170°C, V1 + 120°C to V1 + 160°C, V1 + 120°C to V1 + 150°C, V1 + 130°C to V1 + 170°C, V1 + 130°C to V1 + 160°C, or V1 + 130°C to V1 + 150°C.

[0202] The molding method is not particularly limited. For example, it can be appropriately selected from known molding methods such as extrusion molding, injection molding, blow molding, and foam molding. The resin composition of the present embodiment has excellent fluidity at high temperatures, and thus has excellent moldability and is particularly suitable for injection molding.

[0203] The use of the resin molded product containing the resin composition of the present embodiment is not particularly limited. For example, it can be suitably used for uses such as automotive interior and exterior trim parts, home appliances, office equipment parts, and building materials.

[0204] The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments.

[0205] Examples

[0206] Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

[0207] <Manufacture of maleimide-based copolymer (A1)>

[0208] The maleimide-based copolymer (A1) was manufactured using the following method.

[0209] Into an autoclave with a capacity of 120 liters equipped with a stirrer, 25 parts by mass of styrene, 9 parts by mass of acrylonitrile, 3 parts by mass of maleic anhydride, 0.05 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 12 parts by mass of methyl ethyl ketone were charged. After purging the gas phase with nitrogen, the temperature was raised to 90 °C over 40 minutes while stirring. After the temperature rise, while maintaining at 90 °C, a solution obtained by dissolving 23 parts by mass of maleic anhydride and 0.2 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 33 parts by mass of styrene were continuously added over 10 hours. Further, after the addition of maleic anhydride was completed, 7 parts by mass of styrene were continuously added over 2 hours. After adding styrene, the temperature was raised to 120 °C and the reaction was carried out for 1 hour to complete the polymerization. Then, 24 parts by mass of aniline and 0.4 part by mass of triethylamine were added to the polymerization solution, and the reaction was carried out at 140 °C for 7 hours. The imidization reaction solution after the completion of the reaction was put into an exhaust-type screw extruder to remove the volatile components, and a granular maleimide-based copolymer (A1) was obtained.

[0210] The obtained maleimide-based copolymer (A1) had a Tg of 169 °C and a weight-average molecular weight of 141,000.

[0211] In addition, in the maleimide-based copolymer (A1), the content of the aromatic vinyl-based monomer unit (i) was 50.5% by mass, the content of the vinyl cyanide-based monomer unit (ii) was 8.2% by mass, the content of the maleimide-based monomer unit (iii) was 39.8% by mass, and the content of the unsaturated dicarboxylic acid-based monomer unit (v) was 1.5% by mass.

[0212] <Manufacture of maleimide-based copolymer (A2)>

[0213] The maleimide-based copolymer (A2) was manufactured by the following method.

[0214] Into an autoclave with a capacity of 120 liters equipped with a stirrer, 65 parts by mass of styrene, 7 parts by mass of maleic anhydride, 0.2 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 25 parts by mass of methyl ethyl ketone were charged. After purging the system with nitrogen, the temperature was raised to 92 °C, and a solution obtained by dissolving 28 parts by mass of maleic anhydride and 0.18 part by mass of tert-butyl peroxy-2-ethylhexanoate in 100 parts by mass of methyl ethyl ketone was continuously added over 7 hours. After the addition, 0.03 part by mass of tert-butyl peroxy-2-ethylhexanoate was further added and the temperature was raised to 120 °C, and the reaction was carried out for 1 hour to complete the polymerization. Then, 32 parts by mass of aniline and 0.6 part by mass of triethylamine were added to the polymerization solution, and the reaction was carried out at 140 °C for 7 hours. The imidization reaction solution after the completion of the reaction was put into an exhaust-type screw extruder to remove the volatile components, and a granular maleimide-based copolymer (A2) was obtained.

[0215] The obtained maleimide copolymer (A2) has a Tg of 186 °C and a weight-average molecular weight of 110,000.

[0216] In addition, in the maleimide copolymer (A2), the content of the aromatic vinyl monomer unit (i) is 51.9% by mass, the content of the maleimide monomer unit (iii) is 46.4% by mass, and the content of the unsaturated dicarboxylic acid monomer unit (v) is 1.7% by mass.

[0217] <Graft copolymer (B1)>

[0218] The graft copolymer (B1) is produced by the following method.

[0219] The graft copolymer (B1) is produced by emulsion graft polymerization. 126 parts by mass of polybutadiene latex having an average particle diameter of 0.3 μm and a solid content concentration of 49% by mass, 17 parts by mass of styrene-butadiene latex having an average particle diameter of 0.5 μm, a styrene content of 24% by mass, and a solid content concentration of 69% by mass, 1 part by mass of sodium stearate, 0.2 part by mass of sodium formaldehyde sulfoxylate, 0.01 part by mass of tetrasodium ethylenediaminetetraacetate, 0.005 part by mass of ferrous sulfate, and 150 parts of pure water are put into a reaction tank equipped with a stirrer, and the temperature is heated to 50 °C. 45 parts by mass of a monomer mixture of 75% by mass of styrene and 25% by mass of acrylonitrile, 1.0 part by mass of tert-dodecyl mercaptan, and 0.15 part by mass of cumene hydroperoxide are continuously added thereto in batches over 6 hours. After the batch addition is completed, the temperature is raised to 65 °C, and the polymerization is further completed in 2 hours to obtain a latex of the graft copolymer (B1). For the obtained latex, magnesium sulfate and sulfuric acid are used as coagulants, and coagulation is carried out so that the pH of the slurry at the time of coagulation becomes 6.8, followed by washing, dehydration, and drying to obtain a powdery graft copolymer (B1).

[0220] The obtained graft copolymer (B1) has a Tg of -85 °C.

[0221] In addition, in the graft copolymer (B1), the content of the aromatic vinyl monomer unit (i) is 31.9% by mass, the content of the vinyl cyanide monomer unit (ii) is 10.6% by mass, and the content of the conjugated diene monomer unit (iv) is 57.5% by mass.

[0222] <Vinyl copolymer (C1)>

[0223] The vinyl copolymer (C1) is produced by the following method.

[0224] The vinyl-based copolymer (C1) is produced by continuous bulk polymerization. As the reactor, one completely mixed tank-type stirred tank with a capacity of 20 L is used for polymerization. A raw material solution containing 58% by mass of styrene, 22% by mass of acrylonitrile, and 20% by mass of ethylbenzene is prepared and continuously fed into the reactor at a flow rate of 6.5 L / h. In addition, tert-butyl peroxyisopropyl monocarbonate as a polymerization initiator and n-dodecyl mercaptan as a chain transfer agent are continuously added to the supply line of the raw material solution such that the concentration of tert-butyl peroxyisopropyl monocarbonate as the polymerization initiator becomes 150 ppm and the concentration of n-dodecyl mercaptan as the chain transfer agent becomes 400 ppm relative to the raw material solution. The reaction temperature of the reactor is adjusted to be 144°C. The polymer solution continuously withdrawn from the reactor is fed into a vacuum devolatilization tank equipped with a preheater to separate unreacted styrene, acrylonitrile, and ethylbenzene. The temperature of the preheater is adjusted such that the temperature of the polymer in the devolatilization tank becomes 235°C, and the pressure in the devolatilization tank is 0.4 kPa. The polymer is pumped out from the vacuum devolatilization tank by a gear pump, extruded in a strand shape, cooled with cooling water, and then cut to obtain the granular vinyl-based copolymer (C1).

[0225] The Tg of the obtained vinyl-based copolymer (C1) is 108°C, and the weight average molecular weight is 145,000.

[0226] In addition, in the vinyl-based copolymer (C1), the content of the aromatic vinyl-based monomer unit (i) is 73.9% by mass, and the content of the vinyl cyanide-based monomer unit (ii) is 26.1% by mass.

[0227] <Vinyl-based copolymer (C2)>

[0228] The vinyl-based copolymer (C2) is produced by the following method.

[0229] The vinyl copolymer (C2) is produced by continuous bulk polymerization. As the reactor, a single completely mixed tank-type stirred tank with a capacity of 20 L is used for polymerization. A raw material solution containing 48% by mass of styrene, 29% by mass of acrylonitrile, and 23% by mass of ethylbenzene is prepared and continuously supplied to the reactor at a flow rate of 6.5 L / h. In addition, tert-butyl peroxyisopropyl monocarbonate as a polymerization initiator and n-dodecyl mercaptan as a chain transfer agent are continuously added to the supply line of the raw material solution so that the concentration of tert-butyl peroxyisopropyl monocarbonate as a polymerization initiator becomes 200 ppm and the concentration of n-dodecyl mercaptan as a chain transfer agent becomes 1300 ppm. The reaction temperature of the reactor is adjusted to be 145 °C. The polymer solution continuously withdrawn from the reactor is supplied to a vacuum devolatilization tank equipped with a preheater to separate unreacted styrene, acrylonitrile, and ethylbenzene. The temperature of the preheater is adjusted so that the temperature of the polymer in the devolatilization tank becomes 225 °C, and the pressure in the devolatilization tank is 0.4 kPa. The polymer is pumped out from the vacuum devolatilization tank by a gear pump, extruded in a strand shape, cooled with cooling water, and then cut to obtain the granular vinyl copolymer (C2).

[0230] The Tg of the obtained vinyl copolymer (C2) is 108 °C, and the weight-average molecular weight is 91,000.

[0231] In addition, in the vinyl copolymer (C2), the content of the aromatic vinyl monomer unit (i) is 67.9% by mass, and the content of the vinyl cyanide monomer unit (ii) is 32.1% by mass.

[0232] The content of each monomer unit contained in each copolymer obtained above is a value measured by 13 the C-NMR method under the following apparatus and measurement conditions.

[0233] Apparatus name: JNM-ECX series FT-NMR (manufactured by JEOL Ltd.)

[0234] Solvent: deuterated chloroform

[0235] Concentration: 2.5% by mass

[0236] Temperature: 27 °C

[0237] Number of accumulations: 8000 times

[0238] (Example 1)

[0239] The resin composition of Example 1 was prepared by the following method.

[0240] After blending the maleimide copolymer (A1), graft copolymer (B1), and vinyl copolymer (C1) at the compounding ratios (mass %) shown in Table 1, they were extruded using a twin-screw extruder TEM-35B (manufactured by Toshiba Machine Co., Ltd.) to obtain a pelletized resin composition.

[0241] For the obtained resin composition, the melt mass-flow rate, Charpy impact strength, Vicat softening point, gel fraction were measured, and the paintability was evaluated by the following methods. The results are shown in Table 1.

[0242] [Measurement of melt mass-flow rate]

[0243] The measurement was carried out according to JIS K7210 under the conditions of 220 °C and a load of 98 N.

[0244] [Measurement of Charpy impact strength]

[0245] According to JIS K-7111, using a notched test piece, the striking direction was the edgewise direction, and the measurement was carried out under the conditions of a relative humidity of 50% and an atmosphere temperature of 23 °C. It should be noted that a digital impact tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.) was used for the measuring machine.

[0246] [Measurement of Vicat softening point]

[0247] According to JIS K7206, by the 50 method (load: 50 N, heating rate: 50 °C / hour), using a test piece of 10 mm × 10 mm and a thickness of 4 mm, the measurement was carried out. It should be noted that an HDT&VSPT test device (manufactured by Toyo Seiki Seisaku-sho, Ltd.) was used for the measuring machine.

[0248] [Measurement of gel fraction]

[0249] The gel fraction of the resin composition was measured by the following method.

[0250] (1) Precisely weigh 1.5 g of the sample in a 100 mL stoppered conical flask. (s)

[0251] (2) Add 30 mL of methyl ethyl ketone (MEK) and let stand overnight.

[0252] (3) After standing overnight, shake for 10 minutes using a shaker.

[0253] (4) Precisely weigh a 50 mL centrifuge tube made of SUS. (b)

[0254] (5) Transfer the sample solution to the centrifuge tube, rinse the residual liquid in the conical flask with MEK and add it to the centrifuge tube.

[0255] (6) Use a centrifuge to perform centrifugation at 24,000 rpm for 40 minutes.

[0256] (7) After centrifugation, take out the centrifuge tube and discard the supernatant. Then, add a small amount of MEK to the centrifuge tube and discard the supernatant.

[0257] (8) Pre-dry the centrifuge tube in a hot air dryer (70 °C to 75 °C) for 4 hours or more.

[0258] (9) After pre-drying, perform vacuum drying using a vacuum dryer (70 °C, 76 cmHg) for 15 hours or more.

[0259] (10) After vacuum drying, cool to room temperature in a desiccator and perform precise weighing. (a)

[0260] (11) Calculate the gel fraction using the following formula.

[0261] Gel fraction (%) = 100 × (a - b) / s

[0262] [In the formula, a represents the weight after vacuum drying (weight of dry gel + centrifuge tube) (g), b represents the weight of the empty centrifuge tube (g), and s represents the weight of the sample (g)]

[0263] [Evaluation of paintability]

[0264] Use an injection molding machine to mold a square plate of 75 mm × 75 mm × 3 mm under the conditions of a barrel temperature of 220 °C and a mold temperature of 50 °C. For this square plate, use a general urethane-based paint commonly used for painting ABS resin for vehicle exterior decoration, and evaluate the paintability using the following method.

[0265] Primer coat: HIURETHANE No.5000 (metallic black) (manufactured by NOF Corporation)

[0266] Top coat: HIURETHANE No.5300 (transparent) (manufactured by NOF Corporation)

[0267] Film thickness: Primer coat is 15 - 17 μm, top coat is 22 - 25 μm

[0268] Drying time: 75 °C, 25 minutes

[0269] For the surface state of the obtained painted molded product, evaluate by visual inspection according to the following criteria.

[0270] AA: There are no irregularities on the painted surface.

[0271] A: A little irregularity is confirmed on the painted surface.

[0272] C: Many irregularities were confirmed on the painted surface.

[0273] (Examples 2 - 7)

[0274] As shown in Table 1, the types and mixing ratios of the polymers were changed, and other than that, the resin compositions were prepared in the same manner as in Example 1. In addition, the obtained resin compositions were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0275] (Comparative Examples 1 - 6)

[0276] As shown in Table 2, the types and mixing ratios of the polymers were changed, and other than that, the resin compositions were prepared in the same manner as in Example 1. In addition, the obtained resin compositions were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0277] [Table 1]

[0278]

[0279] [Table 2]

[0280]

Claims

1. A resin composition comprising: A maleimide copolymer (A) having aromatic vinyl monomer units, vinyl cyanide monomer units, unsaturated dicarboxylic acid monomer units, and maleimide monomer units; A graft copolymer (B) obtained by graft-polymerizing at least one selected from the group consisting of aromatic vinyl monomers and vinyl cyanide monomers onto a polymer (b) having conjugated diene monomer units; and A vinyl copolymer (C) having aromatic vinyl monomer units and vinyl cyanide monomer units and not having maleimide monomer units, Based on 100 parts by mass of the total amount of the maleimide copolymer (A), the graft copolymer (B), and the vinyl copolymer (C), the total content of aromatic vinyl monomer units is 55.0 to 64.0 parts by mass, the total content of vinyl cyanide monomer units is 16.0 to 25.0 parts by mass, the total content of maleimide monomer units is 3.0 to 15.0 parts by mass, the total content of conjugated diene monomer units is 10.0 to 18.0 parts by mass, and the total content of unsaturated dicarboxylic acid monomer units is 0.05 to 10.0 parts by mass, The resin composition has a melt mass flow rate of 3 to 23 g / 10 min under the conditions of 220°C and 98 N load, and the melt mass flow rate is measured by the method described in JIS K 7210. The content of the maleimide copolymer (A) is 5 to 40% by mass, the content of the graft copolymer (B) is 16 to 34% by mass, and the content of the vinyl copolymer (C) is 40 to 74% by mass.

2. The resin composition according to claim 1, wherein, The maleimide copolymer (A) contains a maleimide copolymer (A-1) having a maleimide monomer unit content of 20.0% by mass or more.

3. The resin composition according to claim 2, wherein, The content of the maleimide copolymer (A-1) is 5 to 40% by mass based on the total amount of the resin composition.

4. The resin composition according to any one of claims 1 to 3, wherein, The graft copolymer (B) contains a graft copolymer (B-1) having a conjugated diene monomer unit content of 45.0 to 65.0% by mass.

5. The resin composition according to claim 4, wherein The content of the graft copolymer (B-1) is 16 to 34% by mass based on the total amount of the resin composition.

6. The resin composition according to any one of claims 1 to 3, wherein, The vinyl copolymer (C) contains a vinyl copolymer (C-1) having a total content of aromatic vinyl monomer units and vinyl cyanide monomer units of 80.0% by mass or more.

7. The resin composition according to claim 6, wherein The content of the vinyl copolymer (C-1) is 40 to 74% by mass based on the total amount of the resin composition.

8. The resin composition according to any one of claims 1 to 3, wherein The gel fraction of the resin composition is 15 to 25% by mass based on the total amount of the resin composition.

9. A resin molded article comprising the resin composition according to any one of claims 1 to 8.

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