JPH10158466A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition improved in surface scratch resistance without detriment to the mechanical properties (e.g. impact resistance) and initial surface gloss inherent in the constituent rubber-reinforced styrene resin by mixing the styrene resin with a polymer comprising glutaric anhydride structural units and maleimide structural units. SOLUTION: The polymer added is desirably a polymer comprising glutaric anhydride structural units represented by formula I (wherein R<1> and R<2> are each H or an aliphatic hydrocarbon group) and maleimide structural units represented by formula II (wherein R<3> and R<4> are each H or an aliphatic hydrocarbon group; R<5> is H, an aliphatic hydrocarbon group or a halogen). This polymer can solve the problems that the surface hardness of the rubber- reinforced styrene resin is low because the resin contains a rubbery polymer, thereby the molding is liable to scratches and loses its initial surface gloss.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition having excellent scratch resistance while utilizing the features of a rubber-reinforced styrene resin.

[0002]

2. Description of the Related Art Generally, ABS resin, AES resin, AC
Rubber reinforced styrene resins such as S resin and AAS resin
It is composed of a dispersion layer formed by grafting an aromatic vinyl compound-unsaturated nitrile copolymer onto a rubbery polymer and a continuous layer formed by an aromatic vinyl compound-unsaturated nitrile copolymer. Excellent balance between mechanical properties such as mechanical strength and processability, and the properties can be adjusted widely by changing the copolymer composition ratio, so that molded products can be used in a wide range of fields such as vehicles, household goods, sundries, and general equipment. It is used. However, the rubber-reinforced styrene-based resin has a disadvantage that the surface hardness is low due to containing the rubbery polymer, and the molded product is easily damaged. For example, when used as an exterior material for automobiles, the surface may be scratched by a brush or the like during car washing, and when used as household goods, use a scourer or broom to clean or wash. Then, abrasion is generated on the surface, and the surface gloss is easily lost. Such surface flaws degrade the glossy appearance originally possessed by the molded article. Therefore, in order to solve this drawback, conventionally, the surface of the molded article has been painted or a surface protective coat has been applied.

[0003]

However, in the case of the above-mentioned solution, post-processing by painting or coating is necessary, which not only complicates the manufacturing process but also leads to a remarkable increase in cost. Therefore, these methods are practically disadvantageous as methods for improving the scratch resistance of a molded article made of a rubber-reinforced styrene resin. Under such circumstances, an object of the present invention is to provide a novel rubber-reinforced styrenic resin having improved surface scratch resistance while utilizing mechanical properties such as impact resistance inherent in rubber-reinforced styrene resin and initial surface glossiness. To provide a suitable thermoplastic resin composition.

[0004]

Means for Solving the Problems As a result of intensive studies, the inventors of the present invention have found that a rubber-reinforced styrene resin is blended with a polymer containing both a glutaric anhydride structural unit and a maleimide structural unit to prevent damage. The present inventors have found that the sticking property is remarkably improved, and as a result of further study, completed the present invention.

That is, the present invention firstly provides a thermoplastic resin comprising (A) a rubber-reinforced styrenic resin; and (B) a polymer containing a glutaric anhydride structural unit and a maleimide structural unit. A composition.

Further, the present invention secondly comprises (A) a rubber-reinforced styrene resin; (B) a polymer containing a glutaric anhydride structural unit and a maleimide structural unit; and (C) a maleimide structural unit. A thermoplastic resin composition comprising an aromatic vinyl compound-unsaturated nitrile copolymer.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The rubber-reinforced styrenic resin in the present invention is a rubber-like polymer, an aromatic vinyl compound, a graft polymer obtained by graft-polymerizing an unsaturated nitrile and optionally another ethylenically unsaturated monomer, Alternatively, it is a mixture of the graft polymer and a polymer comprising an aromatic vinyl compound, an unsaturated nitrile and, if desired, another ethylenically unsaturated monomer. Representative examples of the rubber-reinforced styrene resin include ABS (acrylonitrile-butadiene rubber-styrene) resin, AES (acrylonitrile-ethylene-propylene rubber-styrene) resin, ACS (acrylonitrile-chlorinated polyethylene-styrene) resin,
AAS (acrylonitrile-acrylic rubber-styrene) resin and the like. Examples of the rubbery polymer which is one component of the rubber-reinforced styrene resin include diene rubbers such as polybutadiene rubber, acrylonitrile / butadiene copolymer rubber, and styrene / butadiene copolymer rubber; polybutyl acrylate, polypropyl Acrylic rubbers such as acrylate and poly-2-ethylhexyl acrylate; chlorinated polyethylene; ethylene / propylene / non-conjugated diene rubber can be used. Examples of the aromatic vinyl compound to be graft-polymerized to these rubber polymers include, for example, styrene, chlorostyrene, methyl styrene, α-methyl styrene, etc., and the rubber polymer together with the aromatic vinyl compound. As the unsaturated nitrile to be graft-polymerized,
For example, acrylonitrile and the like can be mentioned.
Other ethylenically unsaturated monomers that can be graft-polymerized with an aromatic vinyl compound and an unsaturated nitrile, if desired, include methacrylic monomers such as methyl methacrylate and ethyl methacrylate. .

The method for graft-polymerizing an aromatic vinyl compound, an unsaturated nitrile and, if desired, another ethylenically unsaturated monomer onto the rubbery polymer is not particularly limited. Emulsion polymerization, bulk polymerization,
Known methods such as suspension polymerization can be employed. The composition ratio of each component in the rubber-reinforced styrene-based resin is not particularly limited, but generally, the aromatic vinyl compound is 80 to 50% by weight based on the raw material compound,
2 to 50% by weight of unsaturated nitrile, 10% of rubbery polymer
A rubber-reinforced styrene-based resin obtained by using each component so as to be in the range of 30 to 30% by weight is preferable. The graft ratio of the rubber-reinforced styrene-based resin is not particularly limited, but generally, a polymer obtained by polymerization so as to have a graft ratio in the range of 20 to 80% is preferable.
The rubber-reinforced styrene-based resin may contain an inorganic compound, if desired.

As the polymer (B) containing a glutaric anhydride structural unit and a maleimide structural unit in the present invention, for example, the following general formula (1)

[0010]

Embedded image

(Wherein R ¹ and R ² each represent a hydrogen atom or an aliphatic hydrocarbon group)

A glutaric anhydride structural unit represented by the following general formula (2):

[0013]

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(Wherein R ³ and R ⁴ each represent a hydrogen atom or an aliphatic hydrocarbon group, and R ⁵ represents a hydrogen atom, a hydrocarbon group or a halogen atom)

A polymer containing a maleimide structural unit represented by the formula (1) is preferred. Here, examples of the aliphatic hydrocarbon group which may be represented by R ¹ , R ² , R ³ and R ⁴ include, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, Alkyl groups such as pentyl and hexyl are preferred. Examples of the hydrocarbon group represented by R ⁵ include aliphatic hydrocarbons such as alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, and hexyl group. Alicyclic hydrocarbon groups such as cycloalkyl groups such as cyclohexyl group, methylcyclohexyl group, ethylcyclohexyl group, dimethylcyclohexyl group, diethylcyclohexyl group, trimethylcyclohexyl group and triethylcyclohexyl group; phenyl group, tolyl group, xylyl group , Mesityl group, ethylphenyl group,
Examples include an aromatic hydrocarbon group which may be substituted with a halogen atom, such as an aryl group which may be substituted with a halogen atom such as a diethylphenyl group, a triethylphenyl group, a chlorophenyl group, a dichlorophenyl group, and a trichlorophenyl group. Can be Examples of the halogen atom that may be represented by R ⁵ include a chlorine atom and a bromine atom.

In the present invention, it is important that the polymer (B) contains both a glutaric anhydride structural unit and a maleimide structural unit. When the glutaric anhydride structural unit (6-membered ring structure) in the polymer (B) is replaced with a maleic anhydride structural unit (5-membered ring structure), not only the surface hardness is lowered but also the thermal stability of the polymer is reduced. To make it worse,
When a composition with a rubber-reinforced styrenic resin is used, the effect of improving the scratch resistance becomes insufficient, and the polymer may be decomposed during molding, which is not preferable. Further, when the maleimide structural unit (5-membered ring structure) in the polymer (B) is replaced with a glutarimide structure (6-membered ring structure), the surface hardness becomes lower and the surface gloss becomes worse. When a composition with a rubber-reinforced styrene resin is used, the effect of improving the scratch resistance becomes insufficient,
It is not preferable because the initial gloss becomes insufficient.

With respect to the polymer (B) in the present invention,
If the above-mentioned glutaric anhydride structural unit and maleimide structural unit are contained in the molecule, the chemical structure of the other part is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) Acrylate,
Propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth)
(Meth) acrylic acid monomers such as acrylate and benzyl (meth) acrylate; styrene monomers such as styrene, chlorostyrene and α-methylstyrene; olefin monomers such as ethylene and propylene; and acrylonitrile and the like It may comprise a structural unit derived from an ethylenically unsaturated monomer such as an unsaturated nitrile monomer. Among these ethylenically unsaturated monomers, the resulting polymer (B) has particularly good heat resistance,
Methacrylic monomers such as methyl methacrylate, ethyl methacrylate and cyclohexyl methacrylate; styrene monomers as exemplified above are preferred, and methyl methacrylate is particularly preferred. In this specification, “(meth) acrylate” is a general term for “methacrylate” and “acrylate”, and “(meth) acrylate”
“Acrylic acid” is a general term for “methacrylic acid” and “acrylic acid”.

The content of the glutaric anhydride structural unit in the polymer (B) used in the present invention is not particularly limited. However, from the viewpoint of the scratch resistance of the resin composition, 3% by weight of the polymer (B) is used.
It is particularly preferable that the content is not less than 70% by weight from the viewpoint of the mechanical strength of the resin composition. From the viewpoint of the balance between the two, it is particularly preferred that the content be in the range of 10 to 50% by weight.

Although the content of the maleimide structural unit in the polymer (B) used in the present invention is not particularly limited, it should be at least 2% by weight of the polymer (B) from the viewpoint of the surface gloss of the resin composition. Is particularly preferred, and from the viewpoint of the mechanical strength of the resin composition, the content is preferably 70% by weight or less. From the viewpoint of the balance between the two, the content is preferably in the range of 5 to 50% by weight. The molecular weight of the polymer (B) used in the present invention is not particularly limited, but the weight average molecular weight is preferably 10,000 or more from the viewpoint of the scratch resistance of the resin composition, and 1,000,000 or less from the viewpoint of moldability. Is preferred. From the viewpoint of the balance between the two, it is particularly preferable that it is within the range of 30,000 to 120,000.

The production method for obtaining the polymer (B) is not particularly restricted but includes, for example, (meth) acrylic acid and / or tert-butyl (meth) acrylate, cyclohexylmaleimide, failmaleimide and the like. Or a copolymer with one or more other ethylenically unsaturated monomers copolymerizable with these monomers;
A method such as a method comprising performing a thermal decomposition reaction in a temperature range of 0 ° C., preferably 200 to 350 ° C. can be mentioned. At this time, from the viewpoint of the thermal stability of the obtained polymer (B), methacrylic acid and tert-butyl (meth) acrylate as the raw materials for forming the glutaric anhydride structural unit are respectively tert-
Preference is given to using butyl methacrylate.

The ratio of the rubber-reinforced styrenic resin (A) and the polymer (B) constituting the thermoplastic resin composition of the present invention is not particularly limited.
The weight ratio of (B) is preferably in the range of 30/70 to 97/3, and more preferably in the range of 50/50 to 90/10. When the weight ratio of (A) / (B) is 30/70 or more (particularly 50/50)
(Or greater), the mechanical strength of the resin composition increases. On the other hand, when the weight ratio of (A) / (B) is 97
When the ratio is / 3 or smaller (particularly 90/10 or smaller), the scratch resistance and surface gloss of the resin composition are particularly good.

In the thermoplastic resin composition of the present invention,
As long as the effects of the present invention are not lost, additives such as antioxidants, ultraviolet absorbers, light stabilizers, lubricants and the like; inorganic fibers such as glass fibers, carbon fibers, etc. A filler, a flame retardant, a pigment, a dye, and the like may be blended. Further, the thermoplastic resin composition of the present invention may be blended with another polymer, if necessary, as long as the effects of the present invention are not lost. In particular, rubber-reinforced styrenic resin (A) and polymer (B)
In addition to the above, when the aromatic vinyl compound-unsaturated nitrile copolymer (C) containing a maleimide structural unit is blended, the surface glossiness of the thermoplastic resin composition is further improved.

The maleimide structural unit of the copolymer (C) is represented by the following general formula (3)

[0024]

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Wherein R ⁶ and R ⁷ each represent a hydrogen atom or an aliphatic hydrocarbon group, and R ⁸ represents a hydrogen atom, a hydrocarbon group or a halogen atom.

The structural unit represented by the following is preferred. here,
Examples of the aliphatic hydrocarbon group which may be represented by R ⁶ and R ⁷ include the examples described above for R ³ and R ⁴ . Examples of the hydrocarbon group and the halogen atom that may be represented by R ⁸ include the examples described above for R ⁵ .

In the copolymer (C), examples of the aromatic vinyl compound include styrene, chlorostyrene, methylstyrene and α-methylstyrene, and examples of the unsaturated nitrile include acrylonitrile. be able to. The copolymer (C) includes, in addition to the aromatic vinyl compound and the unsaturated nitrile, an ethylenically unsaturated monomer copolymerizable therewith (for example, methyl (meth) acrylate, ethyl (meth) acrylate). Acrylic acid-based monomer).

The content of the maleimide structural unit in the copolymer (C) is not particularly limited. However, from the viewpoint of the gloss and impact resistance of the resin composition, the content of the maleimide structural unit is preferably 20 to 40%. Preferably it is in the range of 80% by weight. Further, the content of the structural unit derived from the aromatic vinyl compound and the content of the structural unit derived from the unsaturated nitrile in the copolymer (C) are not necessarily limited, but the mechanical properties of the resin composition are not limited. In terms of the above, the structural unit derived from the aromatic vinyl compound is one of the copolymers (C)
It occupies the range of 0 to 70% by weight, and the structural unit derived from the unsaturated nitrile is 10 to 70% by weight of the copolymer (C).
Preferably occupies the range.

The molecular weight of the copolymer (C) used in the present invention is not particularly limited, but from the viewpoint of the mechanical properties of the resin composition, the weight average molecular weight is preferably in the range of 5,000 to 300,000.

The method for obtaining the copolymer (C) is not particularly restricted but includes, for example, a monomer having a maleimide structure such as cyclohexylmaleimide and failmaleimide, an aromatic vinyl compound and an unsaturated nitrile. The copolymer (C) can be obtained by copolymerizing the body mixture by a known polymerization method such as solution polymerization, emulsion polymerization, bulk polymerization, or suspension polymerization.

In the thermoplastic resin composition of the present invention, the content of the copolymer (C) is not particularly limited, but particularly excellent surface glossiness, performance such as scratch resistance, impact resistance, etc. For the purpose of expressing while maintaining a high level, 1 to 50% by weight based on the entire resin composition.
Is more preferably within a range of 5 to 30% by weight.

The method for producing the thermoplastic resin composition of the present invention is not particularly limited. For example, a rubber-reinforced styrene resin (A), a polymer (B) and, if desired, a copolymer (C) A method of preparing by melt-mixing using an extruder or the like, or a method of preparing a polymer (B) and optionally a copolymer (C) during a polymerization step for obtaining a rubber-reinforced styrene resin (A). The method of preparing by adding is mentioned.

For the thermoplastic resin composition of the present invention,
Injection molding, extrusion molding, compression molding, and other molding methods commonly used for rubber-reinforced styrenic resins can be applied, whereby any shape such as a sheet, tray, or box can be used. Can be manufactured.

The thermoplastic resin composition of the present invention has a property (surface) such as mechanical properties such as impact resistance and mechanical strength inherent in the rubber-reinforced styrene resin, and a glossy appearance when molded. (Glossiness) while exhibiting improved scratch resistance on the molded product surface. Therefore, the thermoplastic resin composition of the present invention requires, for example, impact resistance, scratch resistance, and surface gloss of interior and exterior members of automobiles, household articles such as tableware, and equipment members such as home appliances and OA equipment. It can be used effectively in the fields mentioned.

[0035]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" indicates "parts by weight".

In the examples, scratch resistance was measured by a pencil scratch test (JIS-K5400), and surface gloss was measured by gloss (JIS-K5400).
-K7105), impact resistance is Izod impact strength (JI
S-K7110).

The following were used as the rubber-reinforced styrene resin (A).

A-1: ABS resin [Ube Sicon Co., Ltd.
Product name "Psycholac T"]

A-2: AES resin [Ube Sicon Co., Ltd.
Product name "UCL AXS SK30"]

A-3: AAS resin [Ube Saikon Co., Ltd.]
Product name "Weatherfill MD110"]

Reference Example 1 (Preparation Example 1 of polymer (B) containing glutaric anhydride structural unit and maleimide structural unit) 70 parts of methyl methacrylate, 20 parts of methacrylic acid, N-
10 parts of phenylmaleimide, 0.3 parts of lauroyl peroxide and 0.2 parts of octylmercaptan were put in a flask and polymerized at 60 ° C. The obtained polymer was pulverized, placed in a glass tube, and heated in a 280 ° C. oil bath under reduced pressure for 2 hours. The obtained polymer was pulverized, charged into an extruder, melt-extruded while degassing at a resin temperature of 260 ° C., and pelletized to obtain a polymer B-1.
Table 1 shows the content of the structural unit constituting the obtained polymer B-1.

Reference Examples 2 and 3 (Preparation examples of polymer (B) containing glutaric anhydride structural unit and maleimide structural unit-2 and 3) 70 parts of methyl methacrylate, 20 parts of methacrylic acid and N-phenylmaleimide Polymer B-2 or B-3 was obtained in the same manner as in Reference Example 1 except that a monomer mixture having the composition shown in Table 1 was used instead of the monomer mixture consisting of 10 parts. Table 1 shows the contents of the structural units constituting the obtained polymers B-2 and B-3.

Reference Example 4 (Preparation Example of Polymer Containing Glutaric Anhydride Structural Unit) Instead of a monomer mixture consisting of 70 parts of methyl methacrylate, 20 parts of methacrylic acid and 10 parts of N-phenylmaleimide, Polymer B-4 was obtained in the same manner as in Reference Example 1 except that the monomer mixture having the composition shown in Example 1 was used. Table 1 shows the content of the structural unit constituting the obtained polymer B-4.

Reference Example 5 (Preparation Example of Polymer Containing Maleimide Structural Unit) Polymer B-5 was obtained by polymerizing a monomer mixture having the composition shown in Table 1 according to a usual suspension polymerization method. . Table 1 shows the content of the structural unit constituting the obtained polymer B-5.

Reference Example 6 (Preparation example of polymer containing structural units of glutaric anhydride and glutarimide) 70 parts of methyl methacrylate, 30 parts of methacrylic acid, 0.3 part of lauroyl peroxide and 0.3 part of octyl mercaptan. Two parts were placed in a flask and polymerized at 60 ° C. The obtained polymer was pulverized, placed in a glass tube, introduced with ammonia, heated in an 280 ° C. oil bath for 20 minutes, and then heated in a 280 ° C. oil bath under reduced pressure for 2 hours. The polymer thus obtained was pulverized, charged into an extruder, melt-extruded while degassing at a resin temperature of 260 ° C., and pelletized to obtain a polymer B-6. Table 1 shows the content of the structural unit constituting the obtained polymer B-6.

[0046]

[Table 1]

Reference Example 7 (Preparation Example 1 of aromatic vinyl compound-unsaturated nitrile copolymer (C) containing maleimide structural unit) 20 parts of acrylonitrile, 60 parts of styrene, 20 parts of N-phenylmaleimide, lauroyl par Oxide 0.3
Parts and 0.2 parts of octyl mercaptan were placed in a flask and subjected to suspension polymerization at 60 ° C. to obtain a copolymer C-1.

Reference Examples 8, 9 (Preparation Example-2, 3 of aromatic vinyl compound-unsaturated nitrile copolymer (C) containing maleimide structural unit) 3) 20 parts of acrylonitrile, 60 parts of styrene, and N-phenylmaleimide 20 In place of the monomer mixture consisting of parts by weight, a copolymer C-2 was obtained in the same manner as in Reference Example 7, except that a monomer mixture having a composition shown in Table 2 was used.
And C-3.

[0049]

[Table 2]

Examples 1 to 11 The polymers (B-1 to B-3) obtained in the above Reference Examples and the rubber-reinforced styrenic resins (A-1 to A-3) were optionally added to the above Reference Examples. (C-1 to C-3)
At the same time, the mixture was preliminarily mixed at a ratio as shown in Table 3 and melt-mixed with a co-rotating twin-screw extruder to obtain a pellet-shaped thermoplastic resin composition. The obtained pellet-shaped resin composition is supplied to an injection molding machine, and a test piece is prepared by injection molding.
The surface gloss and impact resistance were evaluated. Table 3 shows the obtained results.

[0051]

[Table 3]

Comparative Example 1 A rubber-reinforced styrenic resin A-3 was directly supplied to an injection molding machine and injection-molded to prepare a test piece, and its scratch resistance, surface glossiness and impact resistance were evaluated.
Table 4 shows the obtained results.

Comparative Examples 2 to 6 The polymers (B-4 to B-6, C-
1, C-2) and rubber-reinforced styrene resin (A-1, A-
2) was preliminarily mixed at a ratio as shown in Table 4 and melt-mixed by a co-rotating twin-screw extruder to obtain a pellet-shaped thermoplastic resin composition. The obtained pellet-shaped resin composition was injection-molded in the same manner as in Example 1, and the obtained test pieces were evaluated for scratch resistance, surface glossiness and impact resistance. Table 4 shows the obtained results.

Comparative Example 7 Polymer B-1 was directly supplied to an injection molding machine and injection-molded to prepare a test piece. The test piece was evaluated for scratch resistance, surface glossiness and impact resistance. Table 4 shows the obtained results.

Comparative Example 8 The polymer B-1 and the copolymer C-1 were premixed in the proportions shown in Table 4 and melt-mixed in a co-rotating twin-screw extruder to obtain pellets. Was obtained. The obtained pellet-shaped resin composition was injection-molded in the same manner as in Example 1, and the obtained test pieces were evaluated for scratch resistance, surface glossiness and impact resistance.
Table 4 shows the obtained results.

[0056]

[Table 4]

From the above Table 3, the thermoplastic resin compositions according to the present invention obtained in Examples 1 to 11 give molded articles having excellent surface gloss and scratch resistance and also excellent impact resistance. You can see that. And among these, it turns out that the surface glossiness becomes more favorable in the thermoplastic resin composition (when containing a copolymer (C)) obtained in Examples 7-11. On the other hand, in the case of the rubber-reinforced styrene-based resin alone (Comparative Example 1), the scratch resistance of the surface is insufficient, and a resin other than the present invention in which another resin is blended with the rubber-reinforced styrene-based resin. In the case of the compositions (Comparative Examples 2 to 6), it can be seen that at least one of the surface gloss, scratch resistance and impact resistance is insufficient. In addition, it can be seen that the impact resistance is insufficient when the polymer (B) is used alone or when the resin composition is composed of only the polymer (B) and the copolymer (C).

[0058]

As is evident from the above examples, the thermoplastic resin composition of the present invention has improved surface scratch resistance while making use of the impact resistance and surface gloss inherent of the rubber-reinforced styrene resin. It can be seen that it is significantly improved.

Claims (2)

[Claims] 1. A thermoplastic resin composition comprising (A) a rubber-reinforced styrene resin; and (B) a polymer containing a glutaric anhydride structural unit and a maleimide structural unit. 2. A rubber-reinforced styrene resin; (B) a polymer containing a glutaric anhydride structural unit and a maleimide structural unit; and (C) an aromatic vinyl compound containing a maleimide structural unit-unsaturated. A thermoplastic resin composition comprising a nitrile copolymer.