阅读说明：本技术 热塑性树脂组合物及其成形品 (Thermoplastic resin composition and molded article thereof ) 是由 松本真典 西野广平 于 2020-02-21 设计创作，主要内容包括：本发明提供一种耐冲击性、耐药性、流动性以及色相优异,且具有聚碳酸酯和ABS树脂的热塑性树脂组合物及其成形品。该热塑性树脂组合物包含：具有芳香族乙烯基单体单元、腈化乙烯基单体单元、以及马来酰亚胺单体单元的马来酰亚胺系共聚物(A)；聚碳酸酯(B)；含有选自ABS树脂、ASA树脂、AES树脂、SAN树脂中至少一种的树脂(C)；其中在该热塑性树脂组合物的100质量％中,含有马来酰亚胺单体单元0.5～10质量％和聚碳酸酯(B)20～70质量％。(The invention provides a thermoplastic resin composition which has excellent impact resistance, drug resistance, fluidity and color and is provided with polycarbonate and ABS resin and a formed product thereof. The thermoplastic resin composition comprises: a maleimide-based copolymer (A) having an aromatic vinyl monomer unit, a nitrile vinyl monomer unit, and a maleimide monomer unit; a polycarbonate (B); a resin (C) containing at least one resin selected from the group consisting of ABS resin, ASA resin, AES resin and SAN resin; wherein the thermoplastic resin composition contains 0.5 to 10 mass% of maleimide monomer units and 20 to 70 mass% of polycarbonate (B) per 100 mass%.)

1. A thermoplastic resin composition comprising a maleimide-based copolymer (A) having an aromatic vinyl monomer unit, a nitrile vinyl monomer unit, and a maleimide monomer unit; a polycarbonate (B); and a resin (C) selected from at least one of ABS resin, ASA resin, AES resin and SAN resin, wherein the thermoplastic resin composition comprises 0.5-10 mass% of maleimide monomer unit and 20-70 mass% of polycarbonate (B) in 100 mass%.

2. The thermoplastic resin composition according to claim 1, wherein,

the maleimide copolymer (A) contains 40 to 60% by mass of an aromatic vinyl monomer unit, 5 to 20% by mass of a nitrile vinyl monomer unit, and 20 to 50% by mass of a maleimide monomer unit.

3. The thermoplastic resin composition according to claim 1 or claim 2, wherein,

the thermoplastic resin composition contains 2 to 25 mass% of a maleimide copolymer (A), 20 to 70 mass% of a polycarbonate (B), and 5 to 70 mass% of at least one resin (C) selected from the group consisting of ABS resins, ASA resins, AES resins, and SAN resins.

4. The thermoplastic resin composition according to any one of claims 1 to 3, wherein,

the maleimide copolymer (A) further contains 0.1 to 15 mass% of an unsaturated dicarboxylic anhydride monomer unit.

5. The thermoplastic resin composition according to any one of claims 1 to 4, wherein,

the glass transition temperature of the maleimide-based copolymer (A) is from 165 ℃ to 200 ℃.

6. The thermoplastic resin composition according to any one of claims 1 to 5, wherein,

the maleimide copolymer (A) has a light transmittance of 90% or more at a wavelength of 450nm and an optical path length of 10mm in a 4 mass% tetrahydrofuran solution.

7. A molded article comprising the thermoplastic resin composition according to any one of claims 1 to 6.

Technical Field

The present invention relates to a thermoplastic resin composition and a molded article thereof.

Background

Resin compositions comprising polycarbonate and an ABS resin (hereinafter referred to as "PC/ABS-based resins") are excellent in impact resistance, heat resistance, and moldability, and are used in various applications including automobile products, household electric appliances, and office equipment accessories. In the PC/ABS resin. As a method for improving impact resistance, a technique of blending a copolymer containing maleic anhydride is known (see patent documents 1 and 2).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2002-020572

Patent document 2: international laid-open publication No. 2016/098885

Disclosure of Invention

Problems to be solved by the invention

The invention aims to provide a thermoplastic resin composition which can improve the impact resistance of PC/ABS resin and has excellent drug resistance, fluidity and color and a formed product thereof.

Means for solving the problems

The invention has the following characteristics:

(1) a thermoplastic resin composition comprising a maleimide-based copolymer (A) having an aromatic vinyl monomer unit, a nitrile vinyl monomer unit, and a maleimide monomer unit; a polycarbonate (B); and a resin (C) selected from at least one of ABS resin, ASA resin, AES resin and SAN resin, wherein the thermoplastic resin composition comprises 0.5-10 mass% of maleimide monomer unit and 20-70 mass% of polycarbonate (B) in 100 mass%.

(2) The thermoplastic resin composition according to the item (1), wherein the maleimide-based copolymer (A) comprises 40 to 60% by mass of an aromatic vinyl monomer unit, 5 to 20% by mass of a nitrile vinyl monomer unit, and 20 to 50% by mass of a maleimide monomer unit.

(3) The thermoplastic resin composition according to the item (1) or (2), wherein the thermoplastic resin composition comprises 2 to 25% by mass of the maleimide copolymer (A), 20 to 70% by mass of the polycarbonate (B), and 5 to 70% by mass of at least one resin (C) selected from the group consisting of ABS resins, ASA resins, AES resins, and SAN resins.

(4) The thermoplastic resin composition according to any one of (1) to (3), wherein the maleimide-based copolymer (A) further contains 0.1 to 15% by mass of an unsaturated dicarboxylic anhydride monomer unit.

(5) The thermoplastic resin composition according to any one of (1) to (4), wherein the maleimide-based copolymer (A) has a glass transition temperature of 165 to 200 ℃.

(6) The thermoplastic resin composition according to any one of (1) to (5), wherein the maleimide-based copolymer (A) has a light transmittance of 90% or more at a wavelength of 450nm and an optical path length of 10mm in a 4 mass% tetrahydrofuran solution.

(7) A molded article comprising the thermoplastic resin composition according to any one of (1) to (6).

Effects of the invention

The present invention provides a PC/ABS resin having impact resistance and excellent chemical resistance, fluidity and hue, and a molded article thereof.

Detailed Description

< description of terms >

The term "a to B" used in the specification means a is not less than a and not more than B.

Next, embodiments of the present invention will be described in detail.

The thermoplastic resin composition of the present invention comprises: a maleimide-based copolymer (A) having an aromatic vinyl monomer unit, a nitrile vinyl monomer unit, and a maleimide monomer unit; a polycarbonate (B); and at least one resin (C) selected from the group consisting of ABS resin, ASA resin, AES resin, and SAN resin.

< Maleimide-based copolymer (A) >

The maleimide copolymer (A) is obtained by polymerizing an aromatic vinyl monomer unit, a vinyl cyanide monomer unit and a maleimide monomer unit.

Examples of the aromatic vinyl monomer used in the maleimide-based copolymer (A) include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2, 4-dimethylstyrene, ethylstyrene, p-tert-butylstyrene, α -methylstyrene, α -methyl-p-methylstyrene and the like. Among them, styrene is preferable. The aromatic vinyl monomers may be used alone or in combination of 2 or more.

Examples of the vinyl monomer units to be used for the maleimide-based copolymer (A) include acrylonitrile, methacrylonitrile, ethacrylonitrile and fumaronitrile. Among them, acrylonitrile is preferred. The vinyl cyanide monomers may be used alone or in combination of 2 or more.

Examples of the maleimide monomer unit used in the maleimide copolymer (A) include N-alkylmaleimides such as N-methylmaleimide, N-butylmaleimide and N-cyclohexylmaleimide, and N-phenylmaleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-methoxyphenylmaleimide and N-trichlorophenylmaleimide. Among them, N-phenylmaleimide is preferable. The maleimide monomer may be used alone or in combination of 2 or more.

The amount of the aromatic vinyl monomer unit contained in the maleimide-based copolymer (A) is 40 to 60% by mass, preferably 45 to 55% by mass. When the amount of the aromatic vinyl monomer unit is less than 40% by mass, the hue of the thermoplastic resin composition becomes yellowish, and when it exceeds 60% by mass, the heat resistance of the thermoplastic resin composition is lowered.

The amount of the vinyl cyanide monomer unit contained in the maleimide-based copolymer (A) is 5 to 20% by mass, preferably 7 to 15% by mass. If the amount of the vinyl cyanide monomer unit is less than 5% by mass, the effect of improving the chemical resistance of the thermoplastic resin composition cannot be obtained, and if it exceeds 20% by mass, the hue of the thermoplastic resin composition becomes yellowish.

The maleimide monomer unit is contained in the maleimide copolymer (A) in an amount of 20 to 50% by mass, preferably 25 to 45% by mass. If the amount of the maleimide monomer unit is less than 20% by mass, the effect of improving the heat resistance of the thermoplastic resin composition cannot be obtained, and if it exceeds 50% by mass, the impact strength of the thermoplastic resin composition is lowered.

The maleimide-based copolymer (A) may be polymerized with a monomer copolymerizable with other than the aromatic vinyl monomer, the nitrilated vinyl monomer and the maleimide monomer, within a range not impairing the effect of the present invention. Examples of the monomer polymerizable with the maleimide-based copolymer (A) include unsaturated dicarboxylic anhydride monomers such as maleic anhydride, itaconic anhydride, citraconic anhydride and aconitic anhydride; acrylate monomers such as methyl acrylate, ethyl acrylate, and butyl acrylate; methacrylate monomers such as methyl methacrylate and ethyl methacrylate; vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid; acrylamide and methacrylamide, and the like. The monomer copolymerizable with the maleimide-based copolymer (a) may be used alone or 2 or more kinds may be used in combination.

As the monomer copolymerizable with the maleimide-based copolymer (A), an unsaturated dicarboxylic anhydride monomer is preferred.

The amount of the unsaturated dicarboxylic anhydride monomer unit contained in the maleimide-based copolymer (A) is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass. If the amount of the unsaturated dicarboxylic anhydride unit is less than 0.1% by mass, the effect as a solubilizer for the reaction of the unsaturated dicarboxylic anhydride unit with another resin having an amino group or alcohol group terminal cannot be obtained, and if it exceeds 15% by mass, the thermal stability of the thermoplastic resin composition is lowered.

The content of each monomer unit contained in the maleimide-based copolymer (A) is a value measured by C-13NMR under the following measurement conditions.

Device name: FT-NMR AVANCE300 (manufactured by BRUKER corporation)

Solvent: deuterated chloroform

Concentration: 14% by mass

Temperature: 25 deg.C

The number of times of integration: 10000 times

The glass transition temperature of the maleimide-based copolymer (A) is preferably from 165 to 200 ℃ and more preferably from 170 to 200 ℃ from the viewpoint of improving the heat resistance of the kneaded and mixed resin. The glass transition temperature is an extrapolated glass transition onset temperature (Tig) of the maleimide-based copolymer measured by the following apparatus and measurement conditions in accordance with JIS K-7121.

Device name: differential scanning calorimeter Robot DSC6200 (manufactured by Seiko Instruments Inc.)

Temperature rise rate: 10 ℃/min

It is preferable that the maleimide-based copolymer (A) has a light transmittance of 90% or more at a wavelength of 450nm and an optical path length of 10mm when it is a 4% by mass tetrahydrofuran solution. When the light transmittance is less than 90%, the hue of the thermoplastic resin composition obtained by kneading and mixing is deteriorated. The light transmittance is preferably 92% or more. The light transmittance is a value measured by filling a quartz cell for measurement having an optical path length of 10mm with a solution prepared by adjusting a maleimide copolymer to 4% by mass in tetrahydrofuran, and measuring the light transmittance using a spectrophotometer V-670ST (manufactured by JEOL Ltd.).

The polymerization method of the maleimide-based copolymer (A) is, for example, solution polymerization, bulk polymerization or the like. Solution polymerization is preferable from the viewpoint that the maleimide-based copolymer (a) having a uniform copolymerization component can be obtained by adding the monomer to be copolymerized in a batch or continuous manner and simultaneously polymerizing it. The solvent for solution polymerization is preferably non-polymerizable from the viewpoint that by-products are not easily produced and adverse effects are small, and for example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetophenone; ethers such as tetrahydrofuran and 1, 4-dioxane; aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; n, N-dimethylformamide, dimethylsulfoxide, N-methyl-2-pyrrolidone and the like, and methyl ethyl ketone and methyl isobutyl ketone are preferable from the viewpoint of easy removal of the solvent in the devolatilization and recovery of the maleimide copolymer. Any of a continuous polymerization system, a batch system (a batch system), and a semi-batch system may be used as the polymerization process.

The polymerization method of the maleimide-based copolymer (A) is not particularly limited, but it is preferably one obtained by radical polymerization, and the polymerization temperature is preferably in the range of 80 to 150 ℃. The polymerization initiator is not particularly limited, and for example, known azo compounds such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, azobismethylpropionitrile, and azobismethylbutyronitrile; benzoyl oxide, t-butylperoxybenzoate, 1-bis (t-butylperoxy) -3, 3, 5-trimethylcyclohexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexanoate, di-t-butylperoxide, dicumylperoxide, methyl ethyl-3, 3-di- (t-butylperoxy) butyrate, and other known organic peroxides, and 1 or 2 or more of these may be used in combination. From the viewpoint of controlling the reaction rate and polymerization rate of the polymerization, it is preferable to use an azo compound or an organic peroxide having a half-life of 10 hours at 70 to 120 ℃. The amount of the polymerization initiator used is not particularly limited, and is preferably 0.1 to 1.5 parts by mass, more preferably 0.1 to 1.0 part by mass, based on 100 parts by mass of all monomers used in the polymerization. The amount of the polymerization initiator used is preferably 0.1 part by mass or more because a sufficient polymerization rate can be obtained. When the amount of the polymerization initiator used is 1.5 parts by mass or less, the polymerization rate can be suppressed, the reaction can be easily controlled, and the target molecular weight can be easily obtained.

A chain transfer agent may be used in the production of the maleimide-based copolymer (a). The chain transfer agent to be used is not particularly limited, and examples thereof include n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, α -methylstyrene dimer, ethyl thioglycolate, limonene, terpinolene, and the like. The amount of the chain transfer agent to be used is not particularly limited as long as it is within a range in which the target molecular weight can be obtained, and is preferably 0.01 to 0.8 parts by mass, more preferably 0.1 to 0.5 parts by mass, per 100 parts by mass of all monomers used in the polymerization. When the amount of the chain transfer agent used is 0.01 to 0.8 part by mass, the target molecular weight can be easily obtained.

The maleimide-based copolymer (A) can be converted into a maleimide monomer unit by copolymerizing an aromatic vinyl monomer, a vinyl cyanide monomer and an unsaturated dicarboxylic anhydride and then aminating or primary aminating the unsaturated dicarboxylic anhydride monomer unit in the copolymer (post-imidization method). When the maleimide-based copolymer is obtained by the post-imidization method, the amount of residual maleimide monomer in the copolymer is reduced, and therefore, it is preferable.

The primary amine is, for example, an alkylamine such as methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, n-pentylamine, n-hexylamine, n-octylamine, cyclohexylamine, decylamine, an aromatic amine such as a chlorinated or brominated alkylamine, aniline, toluidine, naphthylamine, etc., and among them, aniline and cyclohexylamine are preferable. These primary amines may be used alone or in combination of 2 or more. The amount of the primary amine to be added is preferably 0.7 to 1.1 molar equivalents, more preferably 0.85 to 1.05 molar equivalents, based on the unsaturated dicarboxylic anhydride monomer unit, although not particularly limited. It is preferable that the molar equivalent of the unsaturated dicarboxylic anhydride monomer unit in the maleimide-based copolymer (A) is 0.7 or more because the resulting thermoplastic resin composition has good thermal stability. It is preferably 1.1 molar equivalent or less because the amount of primary amine remaining in the maleimide-based copolymer decreases.

When the maleimide-based copolymer (A) is obtained by the post-imidization method, a catalyst may be used as needed for the purpose of improving the dehydration ring-closure reaction in the reaction of ammonia or a primary amine with an unsaturated dicarboxylic anhydride monomer unit, particularly the conversion from an unsaturated dicarboxylic anhydride monomer unit to a maleimide monomer unit. Although the kind of the catalyst is not particularly limited, for example, tertiary amine may be used. Examples of the tertiary amine include trimethylamine, triethylamine, tripropylamine, tributylamine, N, N-dimethylaniline and N, N-diethylaniline. The amount of the tertiary amine added is not particularly limited, but is preferably 0.01 molar equivalent or more relative to the unsaturated dicarboxylic anhydride monomer unit. The temperature of the imidization reaction in the present invention is preferably 100 to 250 ℃, and more preferably 120 to 200 ℃. If the temperature of the imide reaction is 100 ℃ or higher, the reaction rate is sufficiently high, and therefore, it is preferable from the viewpoint of productivity. It is preferable that the temperature of the imidization reaction is 250 ℃ or lower, because a decrease in physical properties due to thermal deterioration of the imide-based copolymer (A) can be suppressed.

When the maleimide-based copolymer is obtained by the post-imidization method, the aromatic vinyl monomer, the cyanated vinyl monomer, and the unsaturated dicarboxylic anhydride monomer may all be added at the initial stage of polymerization and then polymerized, but since the aromatic vinyl monomer and the unsaturated dicarboxylic anhydride monomer are strongly polymerizable with each other, the aromatic vinyl monomer and the unsaturated dicarboxylic anhydride monomer are consumed at the initial stage of polymerization, and thus a copolymer having a large amount of cyanated vinyl monomer units is easily produced at the later stage of polymerization. As a result, the obtained maleimide-based copolymer has poor hue or a large composition distribution, and is poor in compatibility when kneaded and mixed with a PC/ABS resin or the like, and the physical properties of the obtained thermoplastic resin composition may not be preferable. Therefore, when the maleimide-based copolymer (a) having a good hue and a small (uniform) composition distribution is obtained, a production method having the following steps is preferably used.

An initial polymerization step: the entire amount of the nitrile vinyl monomer, 10 to 90 mass% of the amount of the aromatic vinyl monomer, and 0 to 30 mass% of the amount of the unsaturated dicarboxylic anhydride monomer are mixed and charged at the initial stage of polymerization to start polymerization.

A middle-stage polymerization process: the balance of the feed amount of the aromatic vinyl monomer and the balance of the feed amount of the unsaturated dicarboxylic anhydride monomer are added separately in portions or continuously while continuing the polymerization.

A post-polymerization process: after the entire unsaturated dicarboxylic anhydride monomer charge is completed, the aromatic vinyl monomer is added in a divided or continuous amount of 1/10 or more and polymerized.

An imidization step: the obtained aromatic vinyl-cyanated vinyl-unsaturated dicarboxylic anhydride copolymer is imidized with ammonia or a primary amine to obtain a maleimide copolymer (A).

The method (devolatilization method) of removing volatile components such as a solvent used for solution polymerization or unreacted monomers from the solution after completion of solution polymerization or the solution after post-imidization of the maleimide-based copolymer (a) may be a known method. For example, a vacuum devolatilization tank equipped with a heater or a devolatilization extruder with a vent may be used. The molten maleimide-based copolymer after devolatilization is transferred to a pelletizing step, extruded into a strand form through a porous die, and processed into pellets by a cold cutting method, an air hot cutting method, or an underwater hot cutting method.

The maleimide copolymer (A) is obtained by melt-mixing the polycarbonate (B) and the resin (C) so that the content of maleimide monomer units is 0.5 to 10% by mass, and preferably 1.0 to 5.0% by mass, based on 100% by mass of the thermoplastic resin composition. When the content of the maleimide monomer unit is less than 0.5% by mass, the effect of improving the heat resistance of the thermoplastic resin composition cannot be obtained, and when it exceeds 10% by mass, the impact strength of the thermoplastic resin composition is lowered. In order to adjust the amount of the maleimide monomer unit in the thermoplastic resin composition, the content of the maleimide monomer unit in the maleimide copolymer (a) may be adjusted, or the amount of the maleimide copolymer (a) to be added in the preparation of the thermoplastic resin composition may be adjusted. Although not particularly limited, the maleimide copolymer (a) is preferably contained in an amount of 2 to 25% by mass, more preferably 5 to 20% by mass, based on 100% by mass of the thermoplastic resin composition, because the working efficiency in melt mixing can be improved.

< polycarbonate (B) >

The polycarbonate (B) is a polymer having a carbonate bond represented by the general formula- [ (O-R-O-C (═ O) - ] -. R is generally a hydrocarbon, and is, for example, an aromatic polycarbonate, an aliphatic polycarbonate, or an alicyclic polycarbonate, depending on the type of the 2-valent hydrocarbon-based compound as the raw material. Further, the copolymer may be a homopolymer composed of 1 kind of repeating unit, or a copolymer composed of 2 or more kinds of repeating units. As the 2-valent hydrocarbon-based compound, polycarbonate using bisphenol A as a raw material is industrially widely produced and is therefore preferably used.

The polycarbonate (B) can be produced by a known method. Examples thereof include a transesterification method (also referred to as a melting method or a melt polymerization method) in which bisphenol a and diphenyl carbonate are melted at a high temperature and the formed phenol is removed under reduced pressure and an ester exchange reaction is carried out, a phosgene method (also referred to as an interfacial polymerization method) in which phosgene is allowed to act in an aqueous solution or a suspension aqueous solution of bisphenol a in the presence of methylene chloride to synthesize phosgene, and a pyridine method in which phosgene is allowed to react with bisphenol a in the presence of pyridine or methylene chloride to synthesize phosgene.

The weight average molecular weight of the polycarbonate (B) is preferably 10,000 to 200,000, more preferably 10,000 to 100,000. The weight average molecular weight of the polycarbonate (B) is a value obtained in terms of polystyrene measured by Gel Permeation Chromatography (GPC).

The polycarbonate (B) is contained in an amount of preferably 20 to 70% by mass, more preferably 35 to 65% by mass based on 100% by mass of the thermoplastic resin composition. When the content of the polycarbonate (B) is less than 20% by mass, the impact strength of the thermoplastic resin composition is lowered, and when it exceeds 70% by mass, the flowability of the thermoplastic resin composition is lowered.

< resin (C) >

The resin (C) is at least one resin selected from the group consisting of ABS resin, ASA resin, AES resin and SAN resin.

The ABS resin, ASA resin and AES resin are graft copolymers obtained by graft polymerizing at least a styrene-based monomer and a nitrile-based monomer to a rubbery polymer. The rubber-like polymer is an ABS resin when a butadiene-based rubber such as polybutadiene or a styrene-butadiene copolymer is used, an ASA resin when an acrylic rubber composed of butyl acrylate, ethyl acrylate or the like is used, or an AES resin when an ethylene-based rubber such as an ethylene- α -olefin copolymer is used. In the graft polymerization, 2 or more of these rubbery polymers may be used in combination.

The ABS resin can be produced by a known method. For example, there can be cited 2 methods of a production method by continuous bulk polymerization, a method using a graft copolymer obtained by emulsion polymerization and a granular SAN resin obtained by continuous bulk polymerization.

The method for producing a graft copolymer by emulsion polymerization is a method of emulsion graft polymerizing a styrene-based monomer and a vinyl nitrile-based monomer in a latex of a rubbery polymer (hereinafter referred to as "emulsion graft polymerization"). By the emulsion graft polymerization method, a latex of the graft copolymer can be obtained.

In the emulsion graft polymerization method, water, an emulsifier, a polymerization initiator, and a chain transfer agent are used, and the polymerization temperature is preferably in the range of 30 to 90 ℃. Examples of the emulsifier include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. The polymerization initiator is, for example, an organic peroxide such as cumene hydroperoxide, diisopropylbenzene peroxide, tert-butyl peroxyacetate, tert-hexyl peroxybenzoate, tert-butyl peroxybenzoate and the like; persulfates such as potassium persulfate and ammonium persulfate, and azo compounds such as azobisbutyronitrile; reducing agents such as iron ions; secondary reducing agents such as sodium formaldehyde sulfoxylate; and chelating agents such as disodium edetate. Chain transfer agents are for example n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, alpha-methylstyrene dimer, ethyl thioglycolate, limonene, terpinolene and the like.

The latex of the graft copolymer can be coagulated by a known method to recover the graft copolymer. For example, a coagulant is added to a latex of a graft copolymer to coagulate the latex, and then the resulting mixture is washed with a dehydrator to dehydrate the latex, followed by a drying step to obtain a powdery graft copolymer.

The content of the monomer remaining in the graft copolymer obtained in the form of powder by the emulsion graft polymerization method is preferably less than 15,000. mu.g/g, more preferably less than 8,000. mu.g/g. The content of the residual monomer can be adjusted by polymerization conditions, and it is a value quantified by gas chromatography.

The content of the rubbery polymer in the graft copolymer obtained by the emulsion graft polymerization method is preferably 40 to 70% by mass, more preferably 45 to 65% by mass, from the viewpoint of impact resistance. The content of the rubbery polymer can be adjusted by the ratio of the styrene-based monomer and the nitrile-based monomer to the rubbery polymer used in the emulsion graft polymerization.

From the viewpoint of impact resistance of the thermoplastic resin composition, the constituent units of the graft copolymer obtained by the emulsion graft polymerization method are preferably 70 to 85 mass% of styrene monomer units and 15 to 30 mass% of nitrile vinyl monomer units, in addition to the rubbery polymer.

The gel component of the graft copolymer is preferably in the form of particles. The gel component is particles of a rubbery polymer obtained by graft-copolymerizing a styrene monomer and a vinyl nitrile monomer, and is a component which is insoluble in an organic solvent such as methyl ethyl ketone and toluene and separated by centrifugation. An occlusion structure in which the styrene-nitrile vinyl copolymer is occluded is formed inside the particles of the rubbery polymer. When the graft copolymer and the styrene-cyanated vinyl-based copolymer are melt-mixed, the gel component is present in the continuous phase of the styrene-cyanated vinyl-based copolymer in the form of particles as a dispersed phase. The gel component is a value calculated by dissolving a graft copolymer of mass W in methylene ketone, precipitating the insoluble component by centrifugation at 20000rpm using a centrifuge, removing the supernatant by decantation to obtain the insoluble component, and then, using the formula gel component (% by mass) of (S/W) × 100 for the mass S of the dried insoluble component after vacuum drying. Alternatively, the gel component can be calculated by dissolving the graft copolymer and the styrene-cyanated vinyl copolymer in methyl ethyl ketone and then centrifuging the resulting solution in the same manner as in the case of the resin composition obtained by melt-mixing the graft copolymer and the styrene-cyanated vinyl copolymer.

The volume average particle diameter of the gel component of the graft copolymer is preferably in the range of 0.10 to 1.0. mu.m, more preferably 0.15 to 0.50. mu.m, from the viewpoint of impact resistance and appearance of a molded article. The volume average particle diameter is a value calculated by cutting an ultrathin section from particles of a resin composition obtained by melt-mixing a graft copolymer and a styrene-cyanated vinyl copolymer, observing with a Transmission Electron Microscope (TEM), and analyzing from an image of the particles dispersed in a continuous phase. The volume average particle diameter can be adjusted by, for example, the particle diameter of a latex of the rubber-like polymer used in the emulsion graft polymerization. The particle size of the latex of the rubbery polymer can be adjusted by the method of adding an emulsifier during emulsion polymerization, the amount of water used, and the like, but in order to achieve the preferable range, a long polymerization time is required, and productivity is low, and among them, there is a method of polymerizing a rubbery polymer having a particle size of about 0.1 μm in a short time and enlarging rubber particles by a chemical coagulation method or a physical coagulation method.

The graft ratio of the graft copolymer is preferably 10 to 100% by mass, more preferably 20 to 70% by mass, from the viewpoint of impact resistance. The graft ratio is a value calculated from the content (RC) of the gel component (G) and the rubbery polymer and using the graft ratio (% by mass) — [ (G-RC)/R ] × 100. The grafting ratio is expressed as: the amount of the styrene-cyanated vinyl copolymer included in the particles of the rubbery polymer per unit mass of the rubbery polymer to be grafted and bonded and the styrene-cyanated vinyl copolymer included in the particles. The graft ratio can be adjusted by the ratio of the monomer to the rubber-like polymer in the emulsion graft polymerization, the kind and amount of the initiator, the amount of the chain transfer agent, the amount of the emulsifier, the polymerization temperature, the charging method (one time/multiple times/continuous), the monomer addition rate, and the like.

The graft copolymer preferably has a toluene swelling degree of 5 to 20 times from the viewpoint of impact resistance and appearance of a molded article. The toluene swelling degree represents the degree of crosslinking of the particles of the rubbery polymer, and is calculated from the mass ratio of the mass of the graft copolymer in a swollen state by toluene to the mass in a dried state after toluene removal by vacuum drying after the insoluble matter is separated by centrifugation or filtration. The degree of swelling in toluene is influenced by the degree of crosslinking of the rubber-like polymer used in the emulsion graft polymerization, and can be adjusted by adding a polyfunctional monomer such as an initiator, an emulsifier, a polymerization temperature, divinylbenzene or the like in the emulsion polymerization of the rubber-like polymer.

SAN resins are copolymers having styrenic monomer units and cyanated vinyl monomer units, such as styrene-cyanated vinyl copolymers.

As other polymerizable monomers of the SAN resin, there may be used, for example, (meth) acrylic acid ester monomers such as methyl methacrylate, acrylic acid ester monomers such as butyl acrylate and ethyl acrylate, (meth) acrylic acid monomers such as methacrylic acid, acrylic acid monomers such as acrylic acid, and N-substituted maleimide monomers such as N-phenylmaleimide.

From the viewpoint of compatibility with polycarbonate, the SAN resin preferably comprises 60 to 90 mass% of styrene-based monomer units and 10 to 40 mass% of nitrile-based monomer units, more preferably 70 to 85 mass% of styrene-based monomer units and 15 to 30 mass% of nitrile-based monomer units. The styrene monomer unit and the vinyl cyanide monomer unit are values measured by 13C-NMR.

As a method for producing the SAN resin, a known method can be used. For example, the polymer can be produced by bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, or the like. The reaction apparatus may be operated by any of a continuous type, a batch type (batch type), and a semi-batch type. From the viewpoint of quality and productivity, bulk polymerization or solution polymerization is preferable, and a continuous type is preferable. Examples of the solvent for bulk polymerization or solution polymerization include alkylbenzenes such as benzene, toluene, ethylbenzene, and xylene, ketones such as acetone and methyl ethyl ketone, and aliphatic hydrocarbons such as hexane and cyclohexane.

In the bulk polymerization or solution polymerization of the SAN resin, a polymerization initiator or a chain transfer agent may be used, and the polymerization temperature is preferably in the range of 120 to 170 ℃. Examples of the polymerization initiator include peroxy ketals such as 1, 1-di (t-butylperoxy) cyclohexane, 2-di (t-butylperoxy) butane, 2-di (4, 4-di-t-butylperoxycyclohexyl) propane and 1, 1-di (t-amylperoxy) cyclohexane; hydrogen peroxides such as cumene hydroperoxide and tert-butyl hydroperoxide; alkyl hydroperoxides such as t-butyl peroxyisopropyl monocarbonate and t-amyl peroxyisononanoate; dialkyl peroxides such as t-butyl cumyl peroxide, di-t-butyl peroxide, dicumyl peroxide, and di-t-hexyl peroxide; peroxy esters such as t-butyl peroxyacetate, t-butyl peroxybenzoate and t-butyl peroxyisopropyl monocarbonate; peroxycarbonates such as t-butyl peroxypropyl carbonate and polyether tetra (t-butyl peroxycarbonate); and N, N '-azobis (cyclohexane-1-carbonitrile), N' -azobis (2-dimethylbutyronitrile), N '-azobis (2, 4-dimethylvaleronitrile), N' -azobis [2- (hydroxymethyl) propionitrile ], and the like, 1 of which may be used or 2 or more thereof may be used in combination. Chain transfer agents are for example n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, alpha-methyl styrene dimer, ethyl thioglycolate, limonene, terpinolene etc.

A known method can be used for devolatilization of the SAN resin from the solution after the polymerization of the SAN resin has been completed to remove volatile components such as unreacted monomers and solvents used in the solution polymerization. For example, a vacuum devolatilization tank equipped with a preheater or a devolatilization extruder with a shower head may be used. The devolatilized SAN resin in a molten state is transferred to a pelletizing step, extruded from a porous die in a strand-like manner, and processed into pellets by a cold cutting method, an air-heated cutting method, or an underwater heated cutting method.

The total of the monomer and solvent contents remaining in the SAN resin is preferably less than 2000. mu.g/g, more preferably less than 1500. mu.g/g. The content of the residual monomer and the solvent can be adjusted by devolatilization conditions, and is a value quantitatively obtained by gas chromatography.

The weight average molecular weight of the SAN resin is preferably 50,000 to 250,000, more preferably 70,000 to 200,000, from the viewpoint of impact resistance and moldability of the resin composition. The weight average molecular weight of the SAN resin is a value obtained in terms of polystyrene measured in a THF solvent by Gel Permeation Chromatography (GPC), and is a value obtained by the same method as that for the maleimide-based copolymer (a). The weight average molecular weight can be adjusted by the kind and amount of the chain transfer agent, the solvent concentration, the polymerization temperature, and the kind and amount of the polymerization initiator at the time of polymerization.

The resin (C) may be 2 types of resins, i.e., a powdery ABS resin obtained by emulsion polymerization and a granular SAN resin obtained by continuous bulk polymerization. Alternatively, a powdery ABS resin obtained by emulsion polymerization and a granular SAN resin obtained by continuous bulk polymerization may be first melt-mixed by an extruder or the like and then formed into a granular ABS resin. Further, there can be cited a method of using a granular ABS resin obtained by continuous bulk polymerization and a powdery ABS resin obtained by emulsion polymerization. There may be mentioned a method in which a granular ABS resin obtained by continuous bulk polymerization and a powdery ABS resin obtained by emulsion polymerization are first melt-mixed by an extruder or the like and then pelletized. Further, a method using a particulate ABS resin obtained by continuous bulk polymerization can be cited.

The resin (C) is preferably contained in an amount of 5 to 70% by mass, more preferably 20 to 60% by mass, based on 100% by mass of the thermoplastic resin composition. When the content of the resin (C) is less than 5% by mass, the chemical resistance of the thermoplastic resin composition decreases, and when it exceeds 70% by mass, the heat resistance of the thermoplastic resin composition decreases.

< thermoplastic resin composition >

The thermoplastic resin composition is obtained by melt-mixing the maleimide copolymer (A), the polycarbonate (B) and the resin (C). The melt-mixing may be carried out by a known method, for example, a method of melt-mixing the maleimide-based copolymer (a), the polycarbonate (B) and the resin (C) by a twin-screw extruder. The twin-screw extruders may be co-rotating or counter-rotating. Examples of the melt mixing apparatus include a single-screw extruder, a multi-screw extruder, a twin-screw rotor continuous kneader, a kneader, and a Banbury mixer. When a twin-screw extruder is used, the temperature of the barrel may be set within a range of 200 to 320 ℃, preferably 210 to 290 ℃.

The thermoplastic resin composition may contain, in addition to the maleimide-based copolymer (a), the polycarbonate (B) and the resin (C), other resin components such as an impact modifier, a fluidity modifier, a hardness modifier, an antioxidant, an inorganic filler, a delustering agent, a flame retardant aid, an anti-dripping agent, a slip property imparting agent, a heat dissipating material, an electromagnetic wave absorbing material, a plasticizer, a lubricant, a mold release agent, an ultraviolet absorber, a light stabilizer, an antibacterial agent, an antifungal agent, an antistatic agent, carbon black, titanium oxide, a pigment, a dye, and the like, as long as the effects of the present invention are not impaired.

The thermoplastic resin composition obtained can be molded by a known method, and examples thereof include injection molding, sheet extrusion molding, vacuum molding, blow molding, foam molding, profile extrusion molding, and the like. In molding, the thermoplastic resin composition is generally heated to 200 to 280 ℃ and then processed, preferably 210 to 270 ℃. The molded article can be used for automobile parts, household electric appliances, office equipment parts, and the like.

Examples

The details are described below with reference to examples, but the present invention is not limited to the following examples.

< production example of maleimide-based copolymer (A-1) >

40 parts by mass of styrene, 10 parts by mass of acrylonitrile, 3 parts by mass of maleic anhydride, 0.1 part by mass of 2, 4-diphenyl-4-methyl-1-pentene, and 9 parts by mass of methyl ethyl ketone were added to an autoclave having a capacity of about 120 liters and equipped with a stirrer, and after replacing the gas phase with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes while stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution of 23 parts by mass of maleic anhydride and 0.22 part by mass of t-butylperoxy-2-ethylhexanoate dissolved in 69 parts by mass of methyl ethyl ketone and 19 parts by mass of styrene were continuously added over 7 hours. After the addition of maleic anhydride was completed, 5 parts by mass of styrene was continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120 ℃ to allow the reaction to proceed for 1 hour, and the polymerization was terminated. Subsequently, 23 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-1. The analysis results of the obtained maleimide-based copolymer A-1 are shown in Table 1.

< production example of maleimide-based copolymer (A-2) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 22 parts by mass of styrene, 13 parts by mass of acrylonitrile, 4 parts by mass of maleic anhydride, 0.1 part by mass of 2, 4-diphenyl-4-methyl-1-pentene and 12 parts by mass of methyl ethyl ketone, and after replacing the gas phase with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes while stirring. After the temperature was raised, the mixture was kept at 92 ℃ for 7 hours, and a solution of 25 parts by mass of maleic anhydride and 0.22 part by mass of t-butylperoxy-2-ethylhexanoate dissolved in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added. After the addition of maleic anhydride was completed, 8 parts by mass of styrene was continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120 ℃ to allow the reaction to proceed for 1 hour, and the polymerization was terminated. Subsequently, 26 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-2. The analysis results of the obtained maleimide-based copolymer A-2 are shown in Table 1.

< production example of maleimide-based copolymer (A-3) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 17 parts by mass of styrene, 22 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of 2, 4-diphenyl-4-methyl-1-pentene and 20 parts by mass of methyl ethyl ketone, and the temperature was raised to 92 ℃ over 40 minutes while stirring after replacing the gas phase with nitrogen. After the temperature was raised, the mixture was kept at 92 ℃ for 7 hours, and a solution prepared by dissolving 20 parts by mass of maleic anhydride and 0.25 part by mass of t-butylperoxy-2-ethylhexanoate in 80 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added. After the addition of maleic anhydride was completed, 8 parts by mass of styrene was continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120 ℃ to allow the reaction to proceed for 1 hour, and the polymerization was terminated. Subsequently, 22 parts by mass of aniline and 0.4 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-3. The analysis results of the obtained maleimide-based copolymer A-3 are shown in Table 1.

< production example of maleimide-based copolymer (A-4) >

40 parts by mass of styrene, 10 parts by mass of acrylonitrile, 3 parts by mass of maleic anhydride, 0.1 part by mass of 2, 4-diphenyl-4-methyl-1-pentene, and 9 parts by mass of methyl ethyl ketone were added to an autoclave having a capacity of about 120 liters and equipped with a stirrer, and after replacing the gas phase with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes while stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 part by mass of t-butylperoxy-2-ethylhexanoate in 69 parts by mass of methyl ethyl ketone and 19 parts by mass of styrene were continuously added over 7 hours. After the addition of maleic anhydride was completed, 5 parts by mass of styrene was continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120 ℃ and the reaction was carried out for 1 hour, thereby completing the polymerization. Subsequently, 12 parts by mass of aniline and 0.2 parts by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-4. The analysis results of the obtained maleimide-based copolymer A-1 are shown in Table 1.

< production example of maleimide-based copolymer (A-5) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 25 parts by mass of styrene, 8 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of 2, 4-diphenyl-4-methyl-1-pentene and 15 parts by mass of methyl ethyl ketone, and the gas phase was replaced with nitrogen gas, followed by stirring and heating to 92 ℃ over 40 minutes. After the temperature was raised, the mixture was kept at 92 ℃ and a solution of 30 parts by mass of maleic anhydride and 0.22 part by mass of t-butylperoxy-2-ethylhexanoate dissolved in 90 parts by mass of methyl ethyl ketone and 25 parts by mass of styrene were continuously added over 7 hours. After the addition of maleic anhydride was completed, 7 parts by mass of styrene was continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120 ℃ to allow the reaction to proceed for 1 hour, and the polymerization was terminated. Subsequently, 31 parts by mass of aniline and 0.6 parts by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction liquid after the completion of the reaction was charged into a vented extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-5. The analysis results of the obtained maleimide-based copolymer A-5 are shown in Table 1.

< production example of maleimide-based copolymer (A-6) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 8 parts by mass of acrylonitrile, 4 parts by mass of N-phenylmaleimide, 0.1 part by mass of 2, 4-diphenyl-4-methyl-1-pentene and 16 parts by mass of methyl ethyl ketone, and the gas phase was replaced with nitrogen gas, followed by stirring and raising the temperature to 92 ℃ over 40 minutes. After the temperature was raised, the mixture was kept at 92 ℃ and a solution of 38 parts by mass of N-phenylmaleimide and 0.2 part by mass of t-butylperoxy-2-ethylhexanoate dissolved in 152 parts by mass of methyl ethyl ketone and 23 parts by mass of styrene were continuously added over 7 hours. After the addition of N-phenylmaleimide was completed, 7 parts by mass of styrene were continuously added over 2 hours. After styrene was added, the temperature was raised to 120 ℃ to allow the reaction to proceed for 1 hour, and the polymerization was terminated. The polymerization solution after the completion of the reaction was fed into a vented extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-7. The analysis results of the obtained maleimide-based copolymer A-6 are shown in Table 1.

< production example of maleimide-based copolymer (A-7) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 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, the inside of the system was purged with nitrogen, and then the temperature was raised to 92 ℃ to continuously add a solution of 28 parts by mass of maleic anhydride and 0.18 part by mass of t-butylperoxy-2-ethylhexanoate dissolved in 100 parts by mass of methyl ethyl ketone over 7 hours. After the addition, 0.03 part by mass of t-butylperoxy-2-ethylhexanoate was further added, and the temperature was raised to 120 ℃ to react for 1 hour, thereby completing the polymerization. Subsequently, 32 parts by mass of aniline and 0.6 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-7. The analysis results of the obtained maleimide-based copolymer A-6 are shown in Table 1.

[ Table 1]

(composition analysis)

The maleimide-based copolymer was measured by the C-13NMR method under the measurement conditions described below.

Device name: FT-NMR AVANCE300 (manufactured by BRUKER corporation)

Solvent: deuterated chloroform

Concentration: 14% by mass

Temperature: 27 deg.C

The number of times of integration: 8000 times (times)

(light transmittance at 450 nm)

A4 mass% tetrahydrofuran solution was prepared by dissolving a maleimide-based copolymer in tetrahydrofuran, and the solution was filled in a quartz cell for measurement having an optical path length of 10mm, followed by measurement using a spectrophotometer V-670ST (manufactured by JEOL Ltd.).

(glass transition temperature)

The midpoint glass transition temperature (Tmg) of the maleimide-based copolymer was measured by the following apparatus and measurement conditions in accordance with JIS K-7121.

Device name: robot DSC6200 (manufactured by Seiko electronics Co., Ltd.)

Temperature rise rate: 10 ℃/min

The following materials were used for the polycarbonate (B).

Lupilon S-2000 manufactured by Mitsubishi engineering plastics corporation

As the resin (C), a graft copolymer (C-1) and a styrene-cyanated vinyl copolymer (C-2) are used.

< production example of graft copolymer (C-1) >

The graft copolymer is prepared by emulsion graft polymerization. A reaction vessel equipped with a stirrer was charged with: 143 parts by mass of a polybutadiene latex having an average particle diameter of 0.3 μm; 1.0 part by mass of sodium stearate; 0.2 part by mass of sodium formaldehyde sulfoxylate; 0.01 part by mass of tetrasodium ethylenediamine tetraacetate; 0.005 part by mass of ferrous sulfate; and 150 parts by mass of pure water, and the temperature was heated to 50 ℃. The addition was stepwise and continuously over 6 hours: 50 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; cumene hydroperoxide 0.15 parts by mass. After the stepwise addition, the temperature was raised to 65 ℃ and further the polymerization was completed for 2 hours to obtain a latex of a graft copolymer. The obtained latex was coagulated with hydrochloric acid as a coagulant, washed and dehydrated, and then dried to obtain a graft copolymer (C-1) in powder form. With respect to the obtained graft copolymer, the polybutadiene content was 50 mass% of the raw material mixing ratio at the time of emulsion graft polymerization. The constituent units of the rubbery polymer were removed by NMR measurement, and the content of styrene and acrylonitrile was 75% by mass and 25% by mass, respectively. The gel was obtained by centrifugal separation, and the gel content was 72 mass%. The graft ratio was 44% calculated from the gel content and the polybutadiene content. The toluene swelling degree was 8.1, and the volume average particle diameter was calculated from the observation result by TEM and was 0.3. mu.m.

< preparation example of styrene-nitrilated vinyl copolymer (C-2) >

The styrene-nitrile vinyl copolymer is prepared by continuous bulk polymerization. As a reactor, 1 complete mixing tank-type stirring tank was used, and polymerization was carried out at a capacity of 20L. A raw material solution of 60.5 mass% of styrene, 21.5 mass% of acrylonitrile and 18.0 mass% of ethylbenzene was prepared and continuously supplied to the reactor at a flow rate of 6.5L/h. The raw material solution was continuously added to the raw material solution supply line so that the concentration of t-butyl peroxyisopropyl monocarbonate as a polymerization initiator was 160ppm and the concentration of n-dodecylmercaptan as a chain transfer agent was 1500 ppm. The reaction temperature in the reactor was adjusted to 145 ℃. The polymer solution continuously withdrawn from the reactor was supplied to a vacuum devolatilizer equipped with a preheater, and unreacted styrene, acrylonitrile and ethylbenzene were separated. The temperature of the preheater was adjusted so that the polymer temperature in the devolatilization vessel was 225 ℃ and the pressure in the devolatilization vessel was 0.4 kPa. The polymer was taken out from the vacuum devolatilization vessel by a gear pump, extruded into strands, cooled with cooling water, and then cut to obtain a styrene-acrylonitrile copolymer (C-2) in the form of pellets. The acrylonitrile unit content was determined to be 25% by mass by the kjeldahl method. Further, the weight average molecular weight was 105,000. The weight average molecular weight is a value in terms of polystyrene measured by Gel Permeation Chromatography (GPC) and is measured under the following conditions.

Device name: SYSTEM-21 Shodex (manufactured by Showa Denko K.K.)

Column: connecting 3 PL gel MIXED-B in series

Temperature: 40 deg.C

And (3) detection: differential refractive index

Solvent: tetrahydrofuran (THF)

Concentration: 2% by mass

Calibration curve: prepared using standard Polystyrene (PS) (manufactured by PL corporation).

< examples and comparative examples >

The maleimide-based copolymer (a), polycarbonate (B) and resin (C) were dry blended at the mixing ratios shown in table 2, and then melt-extruded using a twin-screw extruder to obtain pellets of the thermoplastic resin compositions of examples and comparative examples. The twin-screw extruder used was TEM-35B, a Toshiba mechanical Co., Ltd, having a screw diameter D of 35mm and an L/D of 32, under extrusion conditions of a screw rotation number of 250rpm, a cylinder temperature of 260 ℃ and a discharge amount of 30 kg/h. The resulting strands were cut with a pelletizer to obtain 2mm pellets.

[ Table 2]

[ Table 3]

(Maleimide monomer Unit content)

Calculated from the composition analysis results of table 1 and the mixing ratios of tables 2 and 3.

(Charpy impact strength)

According to JIS K-7111, a notched test piece was used, the impact direction was edgewise (edgewise), and the measurement was performed under conditions of a relative humidity of 50% and an atmospheric temperature of 23 ℃. The measuring machine used isA digital impact tester manufactured by donyo seiko corporation. Charpy impact strength of 50kJ/m²The above results were judged to be good.

(melt mass flow Rate)

Measured at 220 ℃ under a load of 98N in accordance with JIS K7210. The melt mass flow rate was judged to be good when it was 5g/10 min or more.

(Vicat softening point)

According to JIS K7206, the measurement was carried out by the 50 method (load 50N, temperature rise rate 50 ℃/hr) using a test piece of 10mm X10 mm and 4mm in thickness. The measuring machine used was an HDT & VSPT test apparatus manufactured by toyo seiko corporation. The Vicat softening point was judged to be good when it was 120 ℃ or higher.

(drug resistance)

The test piece was observed for cracks after 48 hours at 23 ℃ by the 1/4 ellipsometry, and had a shape of 316X 20X 2mm, a long radius of 250mm and a short radius of 150 mm. In order to remove the influence of the forming strain of the test piece, the test piece was prepared by press-forming at 260 ℃ and cutting out the pellets. The reagents were carried out using xylene.

The critical deformation is calculated by the following equation.

ε＝b/2a²{1-(a²-b²)X²/a⁴}^1.5×t×100

Critical deformation: epsilon, long radius: a. short radius: b. test thickness: t, crack generation point: x

The drug resistance was evaluated according to the critical strain according to the following criteria, and 0.6 or more was accepted.

Very good: 0.8 or more, and O: 0.6-0.7, and delta: 0.3 to 0.5, ×: 0.2 or less

(YI (hue))

A9 cm × 5cm plate was molded at a molding temperature of 240 ℃ by an injection molding machine (IS-50EP, manufactured by Toshiba machine Co., Ltd.) and measured with a COLOR difference meter (COLOR-7 e)²Manufactured by shop glass co.) was measured for the yellowness YI. The yellowness YI was judged to be good when it was 50 or less.

The thermoplastic resin compositions of examples 1 to 10 of the present invention can provide resin compositions having excellent impact resistance, flowability, heat resistance, chemical resistance and hue. In contrast, the thermoplastic resin compositions of comparative examples 1 to 7, which do not satisfy the scope of the present invention, are not within the scope of the present invention, and are inferior in one of impact resistance, fluidity, heat resistance, chemical resistance and color phase.