JPH0826206B2 - Heat resistant thermoplastic resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having excellent heat resistance, impact resistance, and weather resistance.

(Prior Art) ABS resins obtained by graft-polymerizing acrylonitrile and styrene on butadiene rubber are widely used today because of their excellent workability, mechanical strength, surface gloss, and chemical resistance. However, this ABS resin is known to have poor weather resistance because the heat resistance is not sufficient depending on the field of use and the rubber component and heat are easily deteriorated by light.

As a method of improving the heat resistance of ABS resin, it is generally known that a part or all of styrene is replaced with α-methylstyrene. However, even with this method, there is a limit to the improvement of heat resistance, and it is not always satisfactory in the fields requiring heat resistance such as parts of automobiles and light electric equipment.

On the other hand, a copolymer of a vinyl monomer such as styrene and an N-substituted maleimide has a high thermal deformation temperature and thermal decomposition temperature (Polymer Theory Papers Vol. 36, No. 7, p. 447). , 1979
Published by The Society of Polymer Science, Japan, inferior in mechanical properties represented by impact resistance [Journal of Polymer Science (J. Polymer Sci) Vol. 38, p. 241, published 1959). There is.

Therefore, it has been proposed to obtain a copolymer having excellent impact strength and heat resistance by reacting an N-substituted maleimide, an offraine unsaturated nitrile and an aromatic vinyl in the presence of a rubber component (US Patent See the specification of 3,721,724). However, conducting a polymerization reaction of maleimide in the presence of a rubber component not only induces a marked decrease in the polymerization rate, but also increases the amount of the copolymer not involved in the binding with the rubber component and also the molecular weight thereof. Since it tends to be low, it was difficult to achieve both heat resistance and impact strength.

Further, a thermoplastic resin composition prepared by blending a copolymer containing an N-substituted maleimide and a graft copolymer based on a rubber-like polymer has been proposed (Japanese Patent Publication No. 46-34).
103, JP-A-53-117050). The thermoplastic resin composition proposed here exhibits excellent impact strength and heat resistance, but is not yet sufficient.

As a method of improving the weather resistance of ABS resin, a method of using a saturated rubber-like polymer having almost no double bonds in the main chain in place of butadiene rubber has been proposed. It is known to use rubber. Although this saturated rubber is stable against ultraviolet rays, it does not have cross-linking or graft active sites,
It is difficult to take the rubber cross-linking or graft structure, which is an essential condition of this resin-rubber two-phase resin, so that the impact strength is low and the rubber is deformed during molding to cause the so-called weld on the surface of the injection molded product. Partial dichroism is likely to occur, and the appearance of the molded product is inferior to that of ABS resin. In order to improve this drawback, various crosslinking agents have been proposed for copolymerization and peroxide crosslinking. However, in general, increasing the degree of cross-linking of acrylic rubber improves the appearance of the molded product, but decreases the impact strength. In addition, since acrylic rubber has a higher glass transition point than butadiene rubber, it has the drawback of being inferior in impact strength, especially at low temperatures.

(Problems to be Solved by the Invention) As described above, conventionally, no thermoplastic resin composition excellent in impact strength and heat resistance, and also excellent in weather resistance has been known. Inferior to any of the above, or still insufficient characteristics were obtained. The present invention solves such a problem.

(Means for Solving Problems) The present invention provides (A) 56 to 70% by weight of N-arylmaleimide and α
-Copolymer obtained by copolymerizing 44 to 30% by weight of an aromatic vinyl compound containing 75 to 100% by weight of methylstyrene.
Copolymer obtained by copolymerizing 50 to 82% by weight of an aromatic vinyl compound containing 10 to 80% by weight, (B) 80 to 100% by weight of α-methylstyrene, and 18 to 50% by weight of a vinyl cyanide compound. 0 to 60% by weight of the combined product, (C) 0.1 to 20% by weight of a polyvalent vinyl compound or a polyvalent allyl compound (hereinafter referred to as a polyfunctional monomer), and an acrylic acid having an alkyl group of 1 to 13 carbon atoms. 50 ester
~ 99.9% by weight of the polymerizable monomer (a) 95 to 60 parts by weight in the presence of the diene polymer (b) 5 to 40 parts by weight emulsion polymerization to a polymerization rate of 50 to 93% by weight. Graft polymer rubber composition [I] obtained by stopping the polymerization after that, in the presence of 30 to 80 parts by weight, 50 to 80% by weight of an aromatic vinyl compound containing 50 to 90% by weight of α-methylstyrene. And 20 to 90% by weight of a graft copolymer obtained by polymerizing 70 to 20 parts by weight of a polymerizable monomer [II] containing 20 to 40% by weight of a vinyl cyanide compound as a whole. The present invention relates to a heat resistant thermoplastic resin composition containing the above.

First, the copolymer as the component (A) [hereinafter referred to as "copolymer (A)"] will be described.

In the copolymer (A), N-arylmaleimide, which is a copolymerization component, is used in an amount of 56 to 70% by weight, preferably 56 to 65% by weight. If it is less than 56% by weight, the heat resistance will decrease. Further, if it exceeds 70% by weight, the fluidity is lowered. When it is in the range of 56 to 70% by weight, excellent heat resistance and impact resistance can be obtained. On the other hand, the aromatic vinyl compound is 30 to 44% by weight, preferably 35
Used up to 44% by weight. 30% by weight of aromatic vinyl compounds
If it is less than 40% by weight, the fluidity is lowered, and if it exceeds 44% by weight, the heat resistance is lowered. The amount of α-methylstyrene in the aromatic vinyl compound is 75 to 100% by weight, preferably 85 to 100% by weight. If the amount of α-methylstyrene in the aromatic vinyl compound is less than 75% by weight, heat resistance will decrease. It should be noted that other copolymerizable monomers such as acrylonitrile and vinyl acetate may be used in an amount of about 5% by weight or less based on all monomers.

The copolymer (A) can be produced by polymerization by any polymerization method such as solution polymerization, bulk polymerization, suspension polymerization and emulsion polymerization.

As a polymerization initiator used in the polymerization, persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate in the emulsion polymerization, water-soluble peroxides such as Kyumen hydroperoxide and the like, and a redox system are used. In other polymerization methods, oil-soluble peroxides such as benzoyl peroxide and t-butyl peroxide, and azo initiators such as azobisisobutyronitrile can be used. These are usually used in an amount of 0.05 to 5% by weight based on the monomers.

When emulsion polymerization is carried out, an anionic, cationic or nonionic surfactant can be used as an emulsifier, and anionic surfactant is particularly preferable. Specifically, sodium lauryl sulfate, potassium oleate, Potassium rosinate, sodium dioctyl sulfosuccinate, sodium dodecylbenzene sulfonate, etc. are available. These are used in an amount of 0.5 to 7% by weight based on the monomers. In addition, in order to improve the emulsion stability, sodium,
Sulfates, chlorides, carbonates and the like of alkali metals such as potassium may be used together. As the dispersant for carrying out suspension polymerization, polyvinyl alcohol, methyl cellulose, water-soluble polymers such as sodium polyacrylate, and inorganic salts such as calcium phosphate can be used. The organic solvents used for solution polymerization include methyl ethyl ketone dimethylformamide, dimethylacetamide, N-methylpyrrolidone,
Tetrahydrofuran or the like is used.

Furthermore, a chain transfer agent may be used in the polymerization,
Examples of the chain transfer agent include n-dodecyl mercaptan, t-dodecyl mercaptan, xanthogen disulfide, terpene and tetrahydronaphthalene. The chain transfer agent is preferably used in an amount of 0.01 to 3% by weight based on the monomer.

As the aryl group of the N-arylmaleimide,
Phenyl group, 4-diphenyl group, 1-naphthyl group, mono- or dimethylphenyl group, 2,6-diethylphenyl group, mono- or dihalogenated phenyl group, 2,4,6-trichlorophenyl group, 2,4 , 6-tribromophenyl group, 4-n-butylphenyl group, 2-methyl-4-n-butylphenyl group, 4-benzylphenyl group, 2,3- or 4-methoxyphenyl group, 2-methoxy- 5-chlorophenyl group, 2-methoxy-5-bromophenyl group, 2,5-dimethoxy-4-chlorophenyl group, 2,3- or 4-ethoxyphenyl group, 2,5-diethoxyphenyl group, 4-phenyl group Enoxyphenyl group, 4-methoxycarbonylphenyl group, 4-cyanophenyl group, 2,3- or 4-
And a nitrophenyl group, 2,3-, 2,4-, 2,5- or 4,3-methylchlorophenyl group. Particularly, a phenyl group and an o-methylphenyl group are preferable.

Aromatic vinyl compounds other than α-methylstyrene used for producing the copolymer (A) include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene,
Chlorostyrene, dichlorostyrene, bromostyrene,
Dibromostyrene, α-ethylstyrene, methyl-α-
Examples include methyl styrene, dimethyl styrene, vinyl naphthalene. Of these, styrene is preferred.

The weight average molecular weight of the copolymer (A) is preferably in the range of 50,000 to 300,000. If it is less than 50,000, the impact strength tends to decrease, and if it exceeds 300,000, the fluidity tends to decrease.

Next, the copolymer which is the component (B) (hereinafter referred to as "copolymer (B)") will be described.

The copolymerization component of the copolymer (B) is α-methylstyrene.
50 to 82% by weight, preferably 70 to 82% by weight, of an aromatic vinyl compound containing 80 to 100% by weight and a vinyl cyan compound
18 to 50% by weight, preferably 18 to 30% by weight, and 0 to 10% by weight of other copolymerizable vinyl monomers are used. Outside of these ranges, the physical properties deteriorate. Also,
If the amount of the other copolymerizable vinyl monomer is too much, the compatibility with the graft copolymer which is the component (A) and the component (C) becomes poor.

As the aromatic vinyl compound used in the copolymer (B), the same monomer as in the copolymer (A) is used. As the vinyl cyan compound, acrylonitrile, methacrylonitrile, chloroacrylonitrile, etc. are used.
Other copolymerizable vinyl monomers include acrylic acid, methacrylic acid, and their alkyl esters (wherein alkyl has 1 to 6 carbon atoms). The copolymer (B) can be obtained by polymerization in the same manner as the copolymer (A) by any polymerization method such as bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization. The weight average molecular weight of the copolymer (B) is 5 to 30.
It is preferable that it is ten thousand. If the molecular weight is too small, the impact strength tends to decrease, and if it is too large, the fluidity tends to decrease.

Next, the graft copolymer (hereinafter referred to as "graft copolymer (C)") which is the component (C) will be described.

The graft polymer rubber composition [I] comprises a diene polymer (b) as a core, an acrylate ester and a polyfunctional monomer as the polymerizable monomer (a) as essential components, and graft polymerization In the synthesis of this graft polymer rubber [I], the polymerization rate of the polymerizable monomer (a) is not completed up to 100%, and the polymerization rate is 50 to 93% by weight, preferably 55 to 75% by weight. It is necessary to terminate the polymerization in%. If the polymerization rate exceeds 93% by weight, the impact resistance decreases, and if it is less than 50% by weight, the heat resistance tends to decrease.

As the diene copolymer (b), polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, polyisoprene, poly-2,3-dimethylbutadiene, polypiperylene, polychloroprene, etc. can be used. As the monomer (a), a polyfunctional monomer, an acrylate ester having an alkyl group having 1 to 13 carbon atoms and, if necessary, another vinyl compound copolymerizable therewith can be used. As other functional monomers, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol diacrylate, divinylbenzene, diallyl phthalate, dicyclopentadiene acrylate, dicyclopentadiene methacrylate and other polyvalent vinyl compounds, triallyl cyanurate,
Examples include polyallyl allyl compounds such as triallyl isocyanurate and diallyl phthalate.
Triallyl isocyanurate and diallyl cyanurate are particularly preferred. The polyfunctional monomer is used in the polymerizable monomer (a) in an amount of 0.1 to 20% by weight, preferably 0.5 to 10% by weight. If it is less than 0.1% by weight, the degree of crosslinking is insufficient and the impact strength and the appearance of the molded product are poor. If it exceeds 20% by weight, the degree of crosslinking is excessive and the impact resistance decreases. Carbon number 1
Examples of the acrylic acid ester having 13 alkyl groups include ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc. Of these, butyl acrylate is particularly preferable. The acrylic ester is 50 to 99.9% by weight, preferably 65 to 99.5% by weight in the monomer (a).
used. If it is less than 50% by weight, the properties of the acrylic rubber deteriorate. Other vinyl compounds that can be copolymerized with acrylic acid ester include styrene, acrylonitrile, vinyl acetate, acrylic acid, methacrylic acid, methacrylic acid alkyl ester (methyl ester, butyl ester, etc.), and the like. In the range 0 to 30% by weight, preferably 0 to 25% by weight. If it exceeds 30% by weight, the characteristics as an acrylic rubber cannot be sufficiently obtained when the polymerizable monomer (a) is polymerized.

The polymerizable monomer (a) and the diene polymer (b)
Is (b) / (a) in a weight ratio of 5/95 to 40/60, preferably 20
Used in the ratio of / 80-35 / 65. If it is less than 5/95, the effect of improving the impact strength and appearance of the molded product is insufficient, and if it exceeds 40/60, the weather resistance deteriorates, which is not preferable.

The polymerization for producing the above graft polymer rubber composition [I] can be carried out by a known emulsion polymerization.
In this emulsion polymerization, as a polymerization initiator, a persulfate such as potassium persulfate, sodium persulfate or ammonium persulfate, a water-soluble peroxide such as kyumen hydroperoxide, or the like and a combination thereof with a compound forming a redox system are used. As the emulsifier, an anionic, cationic or nonionic surfactant can be used, and anionic surfactant is particularly preferable.

The polymerizable monomer [II] which is graft-polymerized in the presence of the graft polymer rubber composition [I] is 50 to 80% by weight of an aromatic vinyl compound containing 50 to 90% by weight of α-methylstyrene and cyanide. A vinyl compound is added in an amount of 20 to 40% by weight, and further a methacrylic acid ester is added in an amount of 0 to 30% by weight. If the proportion of the polymerizable monomer [II] is outside the above range, the physical properties of the thermoplastic resin will be impaired.

Graft polymer rubber composition [I] and polymerizable monomer [I]
I] is used so that the weight ratio of [I] / [II] is 30/70 to 80/20. If it is less than 30/70, the heat resistance decreases,
When it exceeds / 20, the impact strength decreases.

The aromatic vinyl compound and vinyl cyanide compound used in the polymerizable monomer [II] may be the same as those described above, and the methacrylic acid ester may have 1 to 13 carbon atoms such as methyl methacrylate. Examples include methacrylic acid alkyl esters having an alkyl group.

As for the mixing method of the copolymer (A), the copolymer (B) and the graft copolymer (C), when all three are produced by emulsion polymerization, three or any two are mixed in a latex state. There is a method, or a method of mixing solidified powder in each of the three methods, and any method is acceptable. The mixing ratio of these is 10 to 80% by weight of the copolymer (A) and 0 to 80% by weight of the copolymer (B).
60% by weight and 20 to 90% by weight of the graft copolymer (C). When the content of the copolymer (A) is less than 10% by weight, heat resistance is lowered, and when it exceeds 80% by weight, workability is lowered. If the content of the graft copolymer (C) is less than 20% by weight, the impact strength will decrease, and if it exceeds 90% by weight, the heat resistance will decrease. The copolymer (A), the copolymer (B) and the graft copolymer (C) are preferably 10 to 50% by weight and 30 to 60%, respectively.
It is blended in the range of 20% by weight and 20 to 50% by weight. The fluidity can be improved by using the copolymer (B).

The copolymer (A), the graft copolymer (C) and, if necessary, the copolymer (B) are mixed by a method in which each powder or pellet is melt-kneaded with a roll, a screen, a Banbury mixer, a kneader or the like. be able to. When two or more of them are present in a latex form, they can be mixed in a latex state, then salted out, dehydrated and dried to obtain a powder or pellet, which can also be used as a raw material. When two or more of these exist in solution,
After mixing the solution, a powder or pellet may be prepared by a method such as removing volatile matter, and this may be used as a raw material.

Upon such kneading or mixing, an antioxidant, an ultraviolet absorber, a flame retardant, a pigment, glass fiber, a plasticizer, etc. can be added as required. Furthermore, it is possible to make a desired molded product by extrusion molding, injection molding, etc., and its excellent heat resistance, mechanical characteristics, etc.
It can be used for a wide range of purposes such as industrial parts and household appliances parts.

(Example) Hereinafter, the present invention will be specifically described using examples.

I. Production of Copolymer (A) (1) Synthesis of Copolymer (A-1) In a reactor, 60 parts by weight of solid state N-phenylmaleimide, 40 parts by weight of α-methylstyrene, t-dodecyl A mixture of 0.2 parts by weight of mercaptan, 0.25 parts by weight of t-butylperoxy 2-ethylhexanoate and 0.1 parts by weight of 1,1-bis (t-butylperoxy) 3,3,5 tricyclohexane was charged to 65 ° C. Heat to dissolve evenly. Then, polyvinyl alcohol (0.3 parts by weight) was dissolved in deionized water (300 parts by weight), heated to 70 ° C., added thereto, and the suspension was polymerized under stirring at 75 ° C. for 3 hours and then at 110 ° C. for 2 hours. The polymerization rate after the completion of the polymerization was measured by gas chromatography and found to be 98%. The obtained copolymer was dehydrated and dried to obtain a copolymer (A-1). The weight average molecular weight of this copolymer (A-1) (measured by gel permeation chromatography, converted to standard polystyrene, the same applies hereinafter) was 148,000.

(2) Synthesis of copolymer (A-2) 60 parts by weight of solid state N-phenylmaleimide, 40 parts by weight of α-methylstyrene and t were added to a reactor substituted with nitrogen.
A mixture of 0.3 parts by weight of dodecyl mercaptan was charged, and the temperature was raised to 65 ° C to uniformly dissolve the mixture. Then, a mixture of 200 parts by weight of deionized water heated to 65 ° C. and 4 parts by weight of sodium lauryl sulfate was charged to obtain a uniform dispersion state, and then 10 parts by weight of deionized water was added with 0.15 parts by weight of potassium persulfate and sodium sulfite. A solution in which 0.015 parts by weight was dissolved was added, and emulsion polymerization was carried out at 65 ° C. for 2 hours and 90 ° C. for 2 hours while stirring. When the polymerization rate was calculated from the nonvolatile content of the latex after the completion of the polymerization, it was 97%.

This latex was dropped into a 4% aqueous magnesium sulfate solution heated to 95 ° C. for salting out, dehydration and drying to obtain a copolymer (A-2). The weight average molecular weight of the copolymer (A-2) was 133,000.

(3) Synthesis of copolymer (A-3) 36 parts by weight of α-methylstyrene and 4 parts by weight of styrene were used instead of 40 parts by weight of α-methylstyrene. Otherwise, in the same manner as the copolymer (A-1), the copolymer (A-
3) was obtained. The weight average molecular weight of the copolymer (A-3) is 1
It was 45,000.

II. Manufacture of Copolymer (B) (1) Synthesis of Copolymer (B-1) In a reactor purged with nitrogen, 200 parts by weight of deionized water, 3 parts by weight of sodium dodecylbenzenesulfonate, α-methylstyrene. 67.5 parts by weight, styrene 2.5 parts by weight, acrylonitrile 30 parts by weight and potassium persulfate 0.2 parts by weight were charged, and emulsion polymerization was carried out under stirring at 65 ° C. for 6 hours and at 80 ° C. for 2 hours. The polymerization rate was calculated from the nonvolatile content of the latex after polymerization to be 98%.

This latex was dropped into a 4% aqueous magnesium sulfate solution heated to 95 ° C. for salting out, dehydration and drying to obtain a copolymer (B-1). The weight average molecular weight of the copolymer (B-1) was 98,000.

(2) Synthesis of copolymer (B-2) In a reactor, 200 parts by weight of deionized water, 0.5 parts by weight of polyvinyl alcohol, 65 parts by weight of α-methylstyrene, 5 parts by weight of styrene, 30 parts by weight of acrylonitrile and azobis. 1 part by weight of isobutyronitrile was added, and the suspension was polymerized under stirring at 70 ° C for 10 hours and at 105 ° C for 2 hours. The polymerization rate after the polymerization was measured by gas chromatography and found to be 98%.
This slurry was dehydrated and dried to obtain a copolymer (B-2). The weight average molecular weight of the copolymer (B-2) was 107,000.

(3) Synthesis of copolymer (B-3) 60 parts by weight of α-methylstyrene and styrene instead of 67.5 parts by weight of α-methylstyrene and 2.5 parts by weight of styrene
10 parts by weight were used. Otherwise, the copolymer (B-3) was obtained according to the synthesis of the copolymer (B-1). Copolymer (B-
The weight average molecular weight of 3) was 96,000.

III. Production of Graft Copolymer (C) (1) Synthesis of Graft Copolymer (C-1) In a reactor substituted with nitrogen, 240 parts by weight of deionized water, 1.0 part by weight of potassium oleate, and polybutadiene latex 3
0 parts by weight (solid content), butyl acrylate 70 parts by weight, triallyl isocyanurate 1.4 parts by weight, potassium persulfate 0.0
4 parts by weight and 0.004 parts by weight of sodium sulfite were added, and the atmosphere was replaced with nitrogen. The temperature was raised, emulsion polymerization was carried out at 60 to 65 ° C. for 4 hours under stirring, and then the polymerization was stopped by cooling. At this time, the degree of polymerization determined from the nonvolatile content of the latex was 67%. This is designated as rubber latex (D).

Then, in a reaction vessel, 240 parts by weight of deionized water, 1.0 part by weight of potassium oleate, 0.14 part by weight of sodium formaldehyde sulfoxylate, rubber latex (D) 50
Add parts by weight (in solid content), α-methylstyrene 30 parts by weight, styrene 5 parts by weight, acrylonitrile 15 parts by weight, kyumen hydroperoxide 0.14 parts by weight and t-dodecyl mercaptan 0.16 parts by weight, and after nitrogen replacement, the temperature is raised. Then, emulsion polymerization was carried out under stirring at 65 ° C for 6 hours and then at 90 ° C for 2 hours. The polymerization rate calculated from the nonvolatile content of the latex after polymerization was 95%. This latex was dropped into an aqueous solution of potassium alum and salted out, dehydrated and dried to obtain a graft copolymer (C-1).

(2) Synthesis of graft copolymer (C-2) Instead of 30 parts by weight of α-methylstyrene and 5 parts by weight of styrene, 15 parts by weight of α-methylstyrene and 20 parts of styrene were used.
Parts by weight were used. Others are graft copolymers (C-1)
A graft copolymer (C-2) was obtained according to the synthesis of.

(3) Synthesis of Graft Copolymer (C-3) In the synthesis of Graft Copolymer (C-1), during the polymerization of rubber latex (D), the temperature was raised to 90 ° C. at a polymerization rate of 90%, and the polymerization was continued for 2 hours. Then, a graft copolymer (C-3) was obtained according to the synthesis of the graft copolymer (C-1) except that a rubber latex having a polymerization rate of 98% was obtained.

In the above, in order to determine the polymerization rate by gas chromatography, suspended beads were sampled, dissolved in tetrahydrofuran, subjected to gas chromatography analysis, unreacted monomer was detected, and the amount was detected.
The dispersed particles containing only unreacted monomer did not exist in the reaction solution after completion of the polymerization.

The polymerization rate from the non-volatile content of the latex was obtained by taking a part of the latex, heating it to volatilize the residual monomer and water, and determining the non-volatile content ratio (weight%).

However, the non-volatile components at the time of charging are those which do not volatilize during charging, and include resins, emulsifiers, polymerization initiators and the like.

Example 1 Copolymer (A-1) / copolymer (B-1) / graft copolymer (C-1) = 25/0/35 were mixed in a weight ratio, pelletized by an extruder, and injected. Molded with a molding machine. The results of measuring the physical properties of the molded products are shown in Table 1.

Examples 2 to 8 The mixing ratio of the copolymer (A), the copolymer (B) and the graft copolymer (C) [graft copolymer (C-1)] was changed as shown in Table 1. Others were the same as in Example 1, and Examples 2 to 7 were performed. The results of measuring the physical properties of the molded products are shown in Table 1.

Comparative Example 1 The graft copolymer (C) was used as the graft copolymer (C).
The physical properties were evaluated in the same manner as in Example 1 except that -2) was used. As described above, when the amount of α-methylstyrene as the aromatic vinyl compound component of the graft copolymer is small, the compatibility with the heat resistant resin is poor and the impact strength is greatly reduced, and it cannot be put to practical use.

Comparative Example 2 The graft copolymer (C) was used as the graft copolymer (C).
The physical properties were compared in the same manner as in Example 1 except that -3) was used. As described above, when the polymerization rate of the rubber used in the graft copolymer is increased, the impact strength is greatly reduced and it cannot be put to practical use.

(Effect of the Invention) In the thermoplastic resin composition of the present invention, the graft copolymer and the N-substituted maleimide copolymer have excellent compatibility, and the composition has excellent heat resistance and impact resistance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masafumi Shitara, Inventor Masafumi Shitara, 14 Goi Minamikaigan, Ichihara City, Chiba Hitachi Chemical Co., Ltd.Goi Plant (72) Inventor Isamu Hattori 14 Goi Minamikaigan, Ichihara City, Chiba Hitachi Chemical Goi Factory Co., Ltd. (56) Reference JP 59-18716 (JP, A) JP 61-155416 (JP, A) JP 60-38418 (JP, A) JP 62-34938 ( JP, A)

Claims (1)

[Claims] (1) 56-70 N-arylmaleimide (A)
% To 80% by weight of a copolymer obtained by copolymerizing 44 to 30% by weight of an aromatic vinyl compound containing 75 to 100% by weight of α-methylstyrene, and (B) 80 to 80% of α-methylstyrene. 50 to 82% by weight of an aromatic vinyl compound containing 100% by weight and 0 to 60% by weight of a copolymer obtained by copolymerizing a vinyl cyanide compound of 10 to 50% by weight, and (C) a polyvalent vinyl unit amount Body or polyvalent allyl monomer 0.1
To 20% by weight and 50 to 99.9% by weight of an acrylic acid ester having an alkyl group having 1 to 13 carbon atoms, 95 to 60 parts by weight of a polymerizable monomer (a) is used as a diene polymer (b) 5 ~ 40
Graft polymer rubber composition [I] obtained by emulsion-polymerizing to 50 to 93% by weight in the presence of 10 parts by weight of α-methylstyrene in the presence of 30 to 80 parts by weight of the polymer. Aromatic vinyl compound containing 50-90% by weight of
Graft copolymer obtained by polymerizing 70 to 20 parts by weight of a polymerizable monomer [II] containing 80 to 20% by weight and a vinyl cyanide compound of 20 to 40% by weight is 100% in total. A heat-resistant thermoplastic resin composition which is contained so as to be contained in a weight percentage.