JPS6236442A - Heat-resistant resin composition - Google Patents

Abstract

PURPOSE:To lower heat shrinkage factor and to prevent discoloration, by mixing a copolymer of an N-substd. maleimide and an arom. vinyl compd. with a copolymer of an arom. vinyl compd., a vinyl cyanide and other copolymerizable vinyl monomer. CONSTITUTION:The titled compsn. has an intrinsic viscosity of 0.2-0.8l/g (in methyl ethyl ketone at 30 deg.C) and consists of 5-85wt% copolymer (A) composed of 56-85wt% N-substd. maleimide and 15-44wt% arom. vinyl compd. and 15-95wt% copolymer (B) composed of 70.5-82wt% arom. vinyl compd., 18-29.5wt% vinyl cyanide and 0-50wt% copolymerizable vinyl monomer. 15-100wt% said compsn. may be mixed with 0-85wt% graft polymer obtd. by graft-polymerizing 20-50wt% arom. vinyl compd., 5-20wt% vinyl cyanide and 0-45wt% other copolymerizable vinyl monomer in the presence of 30-70wt% rubbery polymer, whereby impact resistance can be further improved.

Description

[Detailed Description of the Invention] a. Industrial Application Field The present invention relates to a heat-resistant resin composition with excellent heat shrinkage rate.
Specifically, the present invention relates to a heat-resistant resin composition containing an N-substituted maleimide.

b. Prior Art A commonly used method for improving the heat resistance of styrene-acrylonitrile copolymers is to replace part or all of the styrene with α-methylstyrene. Also AB
In order to improve the heat resistance of rubber-modified thermoplastic resins represented by S resin, methods using α-methylstyrene as part of the graft monomer or α-methylstyrene-acrylonitrile copolymer and acrylonitrile-butadiene-styrene copolymer have been proposed. It is known how to mix These thermoplastic resins are used as interior materials in the automobile and light electrical fields, but their heat resistance is still insufficient. Therefore, increasing the content of α-methylstyrene improves heat resistance, but the thermal stability during molding deteriorates.
Systems using only α-methylstyrene had limited heat resistance. In addition, as a method of improving the heat resistance of ABS resin, a method of mixing a maleimide copolymer with ABS resin,
A method has been proposed in which a maleimide monomer is copolymerized during graft copolymerization of ABS resin or in a graft component.

The former method has the advantage that the mixing ratio of ABS resin and maleimide copolymer can be changed relatively easily, and therefore, it is possible to relatively easily produce a wide variety of resins with desired physical properties. Suitable for industrial production.

However, for example, a mixture of a maleimide copolymer made of aromatic vinyl and N-phenylmaleimide and a copolymer made of aromatic vinyl and vinyl cyanide proposed in JP-A-57-131213 and ABS resin. Although the heat distortion temperature of the ABS resin obtained by this method is high, the heat shrinkage rate is large at high temperatures, which is the practical heat resistance, and the heat resistance is inferior, and as an ABS resin that requires super heat resistance, it is still not heat resistant. It was insufficient in several points.

C1 Problems to be Solved by the Invention As described above, conventional methods for improving the heat shrinkage rate of maleimide copolymers include increasing the maleimide content; The improvement effect is small and processability is reduced. Furthermore, when mixed with a graft copolymer such as ABS resin, the impact resistance is greatly reduced.As a result of intensive study by the present inventors to solve the above problem, the present inventors discovered that aromatic vinyl with a specific composition By mixing a copolymer (A) of N-substituted maleimide with a copolymer (B) of aromatic vinyl, vinyl cyanide and other copolymerizable monomers having specific composition and properties,
N-substituted maleimide-containing thermoplastic resin composition (1
), and that by mixing the composition with a graft polymer [II] having a specific composition, a thermoplastic resin composition with excellent impact resistance and heat resistance can be obtained. invention has been achieved.

d. Means for solving the problems The present invention provides a copolymer (A) 5 consisting of 56 to 85% by weight of NW-converted maleimide and 15 to 44% by weight of aromatic vinyl.
~85% by weight and 70.5-82% by weight of aromatic vinyl,
A composition consisting of 18-29.5% by weight of vinyl cyanide and 15-95% by weight of a copolymer (B) consisting of 0-50% by weight of other copolymerizable vinyl monomers, and the intrinsic viscosity of the composition 0.2 to 0.8 df/g (30°C in methyl ethyl ketone), a heat resistant resin composition consisting of a heat resistant resin (1) and the heat resistant resin CI), and a rubbery polymer of 30 to 70% by weight. Aromatic vinyl in the presence of 20-50
The above-mentioned heat-resistant resin (1) is made of a graft polymer (II) obtained by graft copolymerizing 5-20% by weight of vinyl cyanide and 0-45% by weight of other copolymerizable vinyl monomers, and the above heat-resistant resin (1) 15- The purpose of the present invention is to provide a heat-resistant resin composition having an excellent heat shrinkage rate, characterized in that it contains 100% by weight of the above graft polymer [■] and 0 to 85% by weight of the above-mentioned graft polymer [■].

Copolymer (A) and copolymer (B) of the heat-resistant resin (1) may be produced by any method such as solution polymerization, suspension polymerization, or emulsion polymerization, but emulsion polymerization is preferred. .

Alternatively, after separately polymerizing copolymer (A) and copolymer (B), (A) and (B) are mixed, preferably (A) and (B) are emulsified (latex) with each other. Alternatively, after the reaction is completed after producing (A), the monomers constituting (B) are polymerized in the presence of (A) in the same reactor to produce (B). Preferred methods include the method of

The amount of N-substituted maleimide used in copolymer (A) is 56 to 8
5% by weight, preferably 56-80% by weight, more preferably 57-70% by weight. This usage amount is 56% by weight.
If it is less than 85% by weight, the heat resistance and heat shrinkage rate will increase and the practical heat resistance will be poor, so it is not preferable.

The amount of aromatic vinyl used is 15 to 44% by weight, preferably 20 to 44% by weight, more preferably 30 to 43% by weight.
If it is less than 15% by weight, the fluidity decreases, which is undesirable, and if it exceeds 44% by weight, the heat resistance decreases, which is not preferable.

The intrinsic viscosity [η] of the copolymer (A) is 0.05 to 0.8 d
l/g (30 DEG C. in methyl ethyl ketone), more preferably from 0.1 to 0.7, particularly preferably from 0.15 to 0.5. If it is less than 0.05, impact strength decreases, and if it exceeds 0.8, fluidity decreases, which is not preferable.

Examples of the N-substituted maleimide used in the present invention include N-phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-t-butylmaleimide, N-cyclohexylmaleimide, N-0-chlorophenylmaleimide, N- -0-methylphenylmaleimide, N-laurylmaleimide, N-naphthylmaleimide, and the like. Among them, N-phenylmaleimide, N-cyclohexylmaleimide, N-0-methylphenylmaleimide, N-0-
10 phenylmaleimide and the like are preferably used. N
The -substituted maleimide may be added in solid (powder) form, dissolved or dispersed in a solvent, or dispersed, particularly emulsified, in water.

The aromatic vinyl used in the present invention includes styrene,
O-methylstyrene, m-methylstyrene, P-methylstyrene, chlorstyrene, dichlorostyrene, bromstyrene, dibromstyrene, α-methylstyrene, α
-ethylstyrene, methyl-α-methylstyrene, dimethylstyrene, vinylnaphthalene and the like. Among these, styrene and α-methylstyrene are preferred, and α-methylstyrene is particularly preferred. Further, among these, it is particularly preferable to use a mixture containing 50% or more of α-methylstyrene in the aromatic vinyl in order to reduce the heat shrinkage rate.

The amount of aromatic vinyl used in the copolymer (B) is 70.
5 to 82% by weight, preferably 71 to 80% by weight,
More preferably, it is 72 to 78% by weight. If it is less than 70.5% by weight, the fluidity decreases, which is undesirable.
If the amount exceeds % by weight, the compatibility of copolymers (A) and (B) will decrease, which is not preferable. The usage range of vinyl cyanide is 18 to 29.5% by weight, preferably 20 to 2% by weight.
It is 9% by weight, more preferably 22 to 28% by weight.

If it is less than 18% by weight, the compatibility will decrease, and if it exceeds 29.5% by weight, the resin will be colored, which is not preferable.

Other monomers copolymerizable with aromatic vinyl compounds and vinyl cyanide compounds include methyl acrylate, ethyl acrylate, propylene acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclo hexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate,
Alkyl esters of acrylic acid such as benzyl acrylate, methyl methacrylate, ethyl methacrylate, propylene methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate,
Methacrylic acid alkyl esters such as cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate, and benzyl methacrylate; unsaturated acid anhydrides such as maleic anhydride, itaconic anhydride, and citraconic anhydride; Examples include saturated acids, and these are used in one type or in two or more types. Among these, methyl methacrylate is particularly preferred from the viewpoint of improving heat shrinkability.

The amount of other monomers copolymerizable with the aromatic vinyl compound and vinyl cyanide compound is preferably 50% in the total monomer mixture.
The amount is not more than 30% by weight, more preferably not more than 30% by weight, particularly preferably not more than 20% by weight.

The intrinsic viscosity [η] of the copolymer (B) is 0.2 to 1.2 d
l 7g (in methyl ethyl ketone at 30°C) is preferred, more preferably 0.2-9.3d l 7g.

Particularly preferably, it is 0.25 to 0.6 dl 7g. If it is less than 0.2dl 7g, the impact strength will decrease;
If it exceeds 2dl 7g, the fluidity will decrease, which is not preferable. The aromatic vinyl used in the copolymer (B) is the same as that in the copolymer (A), but the α-methylstyrene content is arbitrary and not particularly limited.

As the vinyl cyanide, acrylonitrile, methacrylaterile, chloroacrylonitrile, etc. are used, and among these, acrylonitrile is preferred.

A heat-resistant resin CI) is produced from the above copolymer (A) and copolymer (B), and the composition ratio (A)/(B) is from 5 to
85/95-15 weight ratio, preferably 10-15
80/90-20 weight ratio, more preferably 10-20
The weight ratio is 70/90-30.

The content of α-methylstyrene in the aromatic vinyl component in the heat-resistant resin (I) is preferably 50% by weight or more, more preferably 60% by weight or more, particularly preferably 65% by weight or more.

Further, the intrinsic viscosity [η] (in methyl ethyl ketone at 30°C) of the heat-resistant resin is preferably 0.2 to 0.8 d 127 g, more preferably 0.25 to 0.7 d 7 g, and particularly preferably 0.3 to 0. 6dl 7g.

A composition may be obtained in which a graft polymer (II) is blended with the heat-resistant resin (I) to impart impact resistance. The amount of heat-resistant resin (1) used in the composition is 1
5 to 100% by weight, preferably 15 to 85% by weight
, more preferably 20 to 80% by weight. If it is less than 15% by weight, heat resistance will decrease, which is not preferable.

The graft polymer (n) contains 15 to 70% by weight, preferably 20 to 60% by weight, more preferably 25% by weight of aromatic vinyl in the presence of 20 to 70% by weight, preferably 30 to 65% by weight of the rubbery polymer. ~50% by weight, vinyl cyanide 3~
30% by weight, preferably 5-25% by weight, more preferably 8-20% by weight and other copolymerizable 100%-O
It is obtained by graft copolymerizing 45% by weight, preferably 0 to 30% by weight, more preferably 0 to 20% by weight. If it is outside the above range, the impact strength will decrease, which is not preferable. The intrinsic viscosity [η] of the non-grafted component in the graft polymer [1)) is 0.1 to 1.0 (7 g dl at 30°C in methyl ethyl ketone), preferably 0.2
-0.8, more preferably 0.25-0.7.

If it is less than 0.1, the impact strength will be lowered, and if it exceeds 1.0, the fluidity will be lowered, and it is particularly preferably 40 to 120%.

As the rubbery polymer, butadiene rubber, styrene-butadiene copolymer rubber, chloroprene rubber, natural rubber, acrylic rubber, ethylene-propylene copolymer rubber, etc. are used.

The graft polymer (II) can be produced by grafting the above monomer mixture onto a latex of a rubbery polymer by emulsion polymerization, or by a solution polymerization method in which the above monomers are graft polymerized in a solution of a rubbery polymer. Any method may be used.

The aromatic vinyl used in the graft polymer (II) is the same as the aromatic vinyl in copolymers (A) and (B), and vinyl cyanide and other copolymerizable vinyl monomers include copolymers. Those that can be used in (B) can be used in the same manner.

In the present invention, heat-resistant resin [I] and graft polymer (
When producing a composition consisting of copolymer (A)
, a method of simultaneously mixing (B) and a heat-resistant resin (n),
There is also a method of mixing (A) and [II] and then mixing (B), but the composition (I) is prepared in advance from (A) and (B), and then [I] and [ II] is preferable in that a composition having high heat resistance and impact resistance, particularly high impact resistance, can be obtained.

There is no particular restriction on the method of mixing the heat-resistant resin (I) and the graft polymer (II), but there are methods of mixing both in the form of powder or pellets, mixing them as latex and then coagulating to form a mixed polymer. Preferred examples include a method of separating and recovering the polymer, a method of mixing the two solutions together and then solidifying the mixture, and separating and recovering the mixed polymer, and a combination thereof.

Intrinsic viscosity of a composition consisting of [I] and (II). .

The degree [η] (30° C. in methyl ethyl ketone) is preferably 0.2 to 0.9 d/7 g, more preferably 0.3 to 0.7 d/7 g.

The N-substituted maleimide content in the composition is preferably 3 to 40% by weight, more preferably 4 to 35% by weight, and even more preferably 5 to 30% by weight.

In addition to the heat-resistant thermoplastic resin thus obtained, heat-resistant thermoplastic resins such as polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyamide, styrene, etc.
Maleic anhydride copolymer, polycarbosoot, etc. may be mixed, and additives such as fillers, stabilizers, flame retardants, lubricants, deterioration inhibitors, and plasticizers may be added as appropriate.

The heat-resistant thermoplastic resin obtained in the present invention can be used in fields that require heat resistance, such as automobile interior parts and electrical products.

Example The present invention will be specifically explained below using examples.

Example 1 59.5 parts of solid N-phenylmaleimide, 40.5 parts of α-methylstyrene, and 0.5 parts of t-dodecylmercaptan were added to 150 parts of ion-exchanged water and 2.0 parts of sodium dodecylbenzenesulfonate. After charging and raising the internal temperature of the flask to 60°C, add 0.1 part of sodium ethylenediaminetetraacetate and 0.003 part of ferrous sulfate heptahydrate.
A solution of 0.2 parts of sodium aldehyde sulfoxylate dissolved in 20 parts of ion-exchanged water was added, and 0.1 part of diisopropylbenzene hydroperoxide was added to start polymerization, and the water bath temperature was maintained at 60°C. Polymerization was carried out for 2 hours. The conversion rate was 98%. Also, the limiting viscosity [η] is 0
．． 20d17g (30°C in methyl ethyl ketone). This is referred to as latex of copolymer (A).

Separately, 220 parts of ion-exchanged water, 2.0 parts of sodium dodecylbenzenesulfonate, 7 parts of α-methylstyrene
After adding 2.5 parts of acrylonitrile, 27.5 parts of acrylonitrile, and 0.4 parts of 1-)decyl mercaptan to raise the internal temperature of the flask to 60°C, 0.2 parts of sodium ethylenediaminetetraacetate was added.
A solution of 1 part of ferrous sulfate heptahydrate, 0.003 parts of ferrous sulfate heptahydrate, and 0.2 parts of sodium formaldehyde sulfoxylate dissolved in 20 parts of ion-exchanged water was added, and 0.1 part of diisopropylbenzene hydroperoxide was added. Polymerization was started and continued for 3 hours while maintaining the water bath temperature at 60°C. The conversion rate was 99%'. This is designated as the latex of copolymer (B). The intrinsic viscosity [η] of the copolymer (B) is 0.
42 di/g (30°C in methyl ethyl ketone).

The copolymers (A) and (B) thus obtained are (A
) / (B) = 33.6/66.4 in a latex state, coagulated by pressure coagulation using calcium chloride, washed with water, dried, and collected. This is referred to as heat-resistant resin [I].

Next, add 60 parts of polybutadiene rubber latex (calculated as solid content) to the flask, add 150 parts of ion-exchanged water, and 7 parts of styrene.
Add 3 parts of acrylonitrile and bring the internal temperature of the flask to 6 parts.
After raising the temperature to 0°C, a solution of 0.2 parts of sodium pyrophosphate, 0.01 parts of ferrous sulfate heptahydrate, and 0.4 parts of glucose dissolved in 20 parts of ion-exchanged water was added, and cumene hydroperoxide was added. Polymerization was started by adding 0.05 part, and the water bath temperature was maintained at 70°C. After polymerizing for 1 hour, parts by weight of styrene 2I, 9 parts by weight of acrylonitrile, and 0.05 parts by weight of cumene hydroperoxide were continuously added over 3 hours, and polymerization was further continued for 1 hour to terminate the reaction. The polymerization conversion rate was 97%. The obtained copolymer was coagulated using calcium chloride, washed with water, and dried. This is referred to as graft polymer (II).

Heat-resistant resin [I]/graft polymer (II)-75/2
After mixing at a weight ratio of 5:5 to form a belent, the mixture was molded by injection. Heat-resistant resin (1) and [■]/
The measured physical properties of each molded product of the composition [■] are shown in Tables 1 and 2, respectively.

Example 2 Same as Example 1 except that the mixing ratio of copolymer (A) and copolymer (B) obtained in Example 1 was set to (A)/(B) = 22.4/77.6. The same is true.

Example 3 Copolymer (B) was produced by the following method. 200 parts of ion-exchanged water, 2.5 parts of sodium dodecylbenzenesulfonate, 76.9 parts of α-methylstyrene, 4.8 parts of acrylonitrile, and 0.4 parts of t-dodecylmercaptan were charged into a reactor purged with nitrogen, and the reactor was flushed with nitrogen. The mixture was emulsified while stirring at the bottom. When the internal temperature of the reactor reaches 60°C, add 0.2 parts of sodium formaldehyde sulfoxylate, 0.1 part of sodium ethylenediaminetetraacetate, and 0.003 parts of ferrous sulfate heptahydrate to 20 parts of ion-exchanged water. An aqueous solution dissolved in water was added thereto, and then 0.1 part of diisopropylbenzene hydroperoxide was added to initiate polymerization. One hour after the start of polymerization, 14.4 parts of acrylonitrile was continuously added over 6 hours. Then acrylonitrile 2.
A monomer mixture of 9 parts of methyl methacrylate and 1 part of methyl methacrylate was added, and at the same time 176 parts of the above-mentioned initiator was added, and the polymerization was continued for an additional 2 hours to complete the reaction. medium 30℃d lI
/g) was 0.35.

The mixing ratio of copolymers (A) and (B) is (A) / (
B)=13.4/86.6 (in terms of solid content) and mixed in a latex state, and the physical properties were measured according to the method of Example 1.

Example 4 The aromatic vinyl of copolymer (B) was mixed with 38 parts of styrene and α-
The procedure was the same as in Example 1 except that 37 parts of methylstyrene was used as a mixture.6 The intrinsic viscosity [η] of this polymer was 0.46.

Example 5 The aromatic vinyl of copolymer (A) was mixed with 18.3 parts of styrene,
A mixture of 20.8 parts of α-methylstyrene and 60.9 parts of N-phenylmaleimide were prepared. Obtained copolymer (A)
The intrinsic viscosity [η] was 0.25 dl/g (30°C in methyl ethyl ketone). This copolymer (A) and the copolymer (B) of Example 3 were mixed, and the mixing ratio was 13.1/86.
．． It is the same as Example 3 except that it is set to 9.

Example 6 An ES polymer was produced by the following method.

A homogeneous solution was prepared in advance in a stainless steel autoclave with an internal volume of 5 and a ribbon stirring blade.Cola prime number 15, Mooney viscosity 42, 5-ethylidene-2- as diene component.
nl'DM containing norbornene (Japan Synthetic Rubber Co., Ltd. product JSR [1P22) 35 parts by weight, 45.5 parts by weight of styrene, 120 parts by weight of toluene, t-dodecyl mercap°
Add 0.1 part by weight of tan, raise the temperature while stirring, and bring to a boiling temperature of 50
19.5 parts by weight of acrylonitrile, 0.5 parts by weight of pencil liver oxide, 0.1 part by weight of dicumyl peroxide at ℃
part by weight was added, the temperature was further raised, and after reaching 80℃, 8
The polymerization reaction was carried out at a stirring rotation speed of 10 orpm while controlling the temperature to be constant at 0°C.

The temperature was raised to 120°C over 1 hour from 6 hours after the start of the reaction, and the reaction was continued for an additional 2 hours, resulting in a polymerization rate of 9.
It was 7%. After cooling to 100℃, 2.2'
- After adding 0.2 parts by weight of methylene-bis(4-methyl-6-t-bunalphenol) and mixing, the reaction mixture was extracted from the autoclave and removed by steam distillation to remove most of the unreacted monomer and solvent. After distilling off and finely pulverizing,
40 dragon φ bent extrusion 1 (220℃, >700mm 1%
The volatile components were substantially distilled off under vacuum) and the polymer was recovered as pellets.

Heat-resistant resin [I] using the same copolymers (A) and (B) as in Example 1, mixed at a mixing ratio of copolymer (A)/copolymer (B) = 47.1)52.9 and the above ABS graft polymer (I[) as (I)/(n) = 57.1/
42.9 and the physical properties were measured according to Example 1.

Example 7 The same as Example 1 except that N-0-chlorophenylmaleimide was used instead of N-phenylmaleimide. The intrinsic viscosity [η] of the obtained copolymer (A) is Q, 24
It was djBg.

Example 8 The same as in Example 1 except that the copolymer (B) was produced by the following method.

180 parts of ion-exchanged water, 1.8 parts of potassium stearate, 52 parts of α-methylstyrene, 8.8 parts of methyl methacrylate.
0 parts of acrylonitrile, 8.0 parts of acrylonitrile, and 12.0 parts of styrene, and 0.3 parts of tertiary dodecyl mercaptan were charged into a reactor equipped with a stirrer and purged with nitrogen, and emulsified.

After raising the temperature to 40°C with stirring under a nitrogen stream, 0.166B of sodium formaldehyde sulfoxylate, 0.08 part of sodium ethylenediaminetetraacetate and 0.0 part of ferrous sulfate were dissolved in 16 parts of ion-exchanged water.
Add 03 parts of cumene hydroperoxide, and add 03 parts of cumene hydroperoxide.
．． After adding 25 parts of acrylonitrile to start the polymerization reaction, the jacket temperature of the reaction vessel was controlled at 60° C. and the polymerization was continued for 1 hour, after which 10 parts of acrylonitrile was continuously added over 2 hours. After addition, add 20 parts of ion-exchanged water, 0.2 parts of potassium stearate, and 3 parts of acrylonitrile.
．． 0 part of styrene, 7.0 parts of styrene, and 0.1 part of tertiary dodecyl mercaptan were emulsified, and further added to 4 parts of ion-exchanged water were 0.04 part of sodium formaldehyde sulfate, 0.04 part of h-1-silane, and ethylenediaminetetra After adding a solution of 0.02 parts of sodium acetate and 0.002 parts of ferrous sulfate, 0.05 parts of cumene hydroperoxide was added.
1 part was added to carry out a polymerization reaction for 2 hours. The conversion rate was 98%, and the intrinsic viscosity of this copolymer (B) was 0.37 d.
f 7g.

Comparative Example 1 57.2 parts of styrene was charged into an autoclave equipped with a stirrer, and the system was purged with nitrogen gas, and then heated to a temperature of 80°C. To this, 42.8 parts of N-phenylmaleimide,
A solution of 0.3 parts of benzoyl peroxide dissolved in 85 parts of methyl ethyl ketone was added over 10 hours. Polymerization was continued for an additional 2 hours after the addition. The intrinsic viscosity of the obtained copolymer was 0.42 dl 7g. This is referred to as copolymer (A).

Next, 75 parts of styrene and 25 parts of acrylonitrile were dissolved in 100 parts of methyl ethyl ketone, and polymerization was initiated at 80°C with 0.3 part of benzoyl peroxide to produce a copolymer (B) after the reaction was completed. The intrinsic viscosity was 0.41. After mixing this at a mixing ratio of (A)/(B) = 56/44, it was poured into methanol, coagulated, and dried.

The above heat-resistant resin (1) and the grafted product of Example 1 ■
were mixed at a mixing ratio of (1)/(n) = 75/25, and the physical properties were measured according to Example 1.

The heat shrinkage rate at 130° C. is inferior to that of the examples.

Comparative Example 2 The aromatic vinyl of copolymer (B) was 60 parts of styrene,
The procedure was the same as in Example 1 except that 40 parts of acrylonitrile was used instead of vinyl cyanide. The intrinsic viscosity of the copolymer (B) is 0.6
5, and the heat shrinkage rate is relatively good, but the coloring is severe.

g0 Effects of the Invention Since it has high heat resistance and excellent heat shrinkage, the heat-resistant thermoplastic resin obtained by the present invention can be used for interior parts of automobiles, electrical products, etc.

Patent applicant: Japan Synthetic Rubber Co., Ltd. Representative Patent attorney: Hisao Okuyama ゛2'-□-゛-3 (and 2 others)

Claims (8)

[Claims] (1) Copolymer (A) 5-8 consisting of 56-85% by weight of N-substituted maleimide and 15-44% by weight of aromatic vinyl
A copolymer (B
) 15 to 95% by weight, and the composition has an intrinsic viscosity of 0.20.8 dl/g (in methyl ethyl ketone at 30°C). (2) Copolymer (A) 5-8 consisting of 56-85% by weight of N-substituted maleimide and 15-44% by weight of aromatic vinyl
A copolymer (B
) 15 to 95% by weight of a heat-resistant resin [I],
20-50% by weight of aromatic vinyl, 5-20% by weight of vinyl cyanide and 0-45% by weight of other copolymerizable vinyl monomers were graft copolymerized in the presence of 30-70% by weight of a rubbery polymer. 85% by weight of graft polymer [II]
A heat-resistant resin composition characterized by containing the following: (3) N-substituted maleimide is N-phenylmaleimide, N
The heat-resistant resin composition according to claim (1), which is at least one selected from -cyclohexylmaleimide, N-O-methylphenylmaleimide, and N-O-chlorophenylmaleimide. (4) α-methylstyrene content in aromatic vinyl is 50
% or more by weight of the heat-resistant resin composition according to claim (1). (5) A patent claim in which a heat-resistant resin [I] is produced in advance from copolymers (A) and (B), and the heat-resistant resin [I] and the graft polymer [II] are mixed. Range number (
2) The heat-resistant resin composition described in item 2). (6) The heat-resistant resin [I] is obtained by mixing the copolymer (A) and the copolymer (B) in an emulsified state, or is obtained by mixing the copolymer (A) and the copolymer (B) in the presence of the copolymer (A). The heat-resistant resin composition according to claim (2), which is obtained by polymerizing monomers of component B). (7) The heat-resistant resin composition according to claim (2), wherein the intrinsic viscosity [η] of the methyl ethyl ketone soluble portion in the composition is 0.2 to 0.9 dl/g (30°C in methyl ethyl ketone). thing. (8) The heat-resistant resin composition according to claim (1), wherein the copolymerizable vinyl monomer is methyl methacrylate.