JPS5911605B2 - Method for producing graft copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a graft copolymer consisting of polyphenylene ether and a styrene polymer and substantially free of homopolymer of polyphenylene ether.

Polyphenylene ether resin is an engineering plastic with thermal properties, mechanical properties, electrical properties, etc. not found in conventional thermoplastic resins, and is opening up a wide range of fields of use.

The excellent thermal properties of polyphenylene ether resin are due to its extremely high glass transition temperature compared to conventional thermoplastic resins, and its mechanical properties do not change over a wide temperature range. Very good. However, a major drawback of resins mainly composed of polyphenylene ether is that they are inferior in moldability compared to conventional thermoplastic resins, in conjunction with their high glass transition temperatures. Solving moldability without reducing the various properties of this resin will essentially improve the practical and industrial usefulness of this resin. A number of techniques have been disclosed for improving the processability of polyphenylene ether, including a method of mixing it with polystyrene (for example, U.S. Pat. No. 3,383,435), and a method of mixing styrene in the presence of polyphenylene ether. (e.g. Japanese Patent Publication No. 42-22069), a method of graft polymerizing styrene onto polyphenylene ether (e.g. Japanese Patent Publication No. 46-41383), styrene substantially free of polyphenylene ether homopolymer. A method using grafted polyphenylene ether (for example, Japanese Patent Application Laid-open No. 1983
-51150).

Under such circumstances, the inventors of the present invention have previously discovered
No. 197) A method for producing a graft copolymer substantially free of homopolymer of polyphenylene ether was found, but since the graft polymerization temperature was 200°C or lower, the graft copolymer required a desolventization step. It has drawbacks such as the industrial difficulty in handling the polymer, and it has been necessary to develop a process with better productivity. On the other hand, it is generally known that graft copolymers and block copolymers may be produced by melt-kneading two types of polymers or one or more types of polymers and a vinyl compound.

Many techniques related to these mechanochemical reactions are shown in "Polymer Blend" (written by Kunio Goto, published by Nikkan Kogyo Shimbun, November 21, 1972).
However, in thermoplastic resins that do not have reactive groups such as double bonds in the main chain of the polymer, gel-like polymers (linear polymers are cross-bonded in places and swell in the solvent but do not dissolve). There is no known technology that can achieve an extremely high graft polymerization reaction rate without producing a polymer (hereinafter used in the same meaning) or reducing mechanical strength due to the production of low molecular weight substances. Not yet.
When a gel-like polymer is produced, the molding processability is reduced and the surface of the molded product loses its luster, which is not preferred in practice. In addition, in order to improve the graft polymerization reaction rate, when the reaction conditions are made stricter,
A large amount of low-molecular-weight substances are produced, which greatly reduces mechanical properties, especially impact strength, and tends to produce gel-like polymers. The object of the present invention is to provide a graft copolymer composed of polyphenylene ether and a styrene polymer, which has extremely excellent molding processability, has good surface gloss of molded products, and has low molding anisotropy for injection molded products. It is an object of the present invention to provide a method for producing a practically useful molding material with a small amount.

Furthermore, another object is to provide an advantageous manufacturing method using an industrially simple process. Furthermore, another object is to provide a manufacturing method with high industrial productivity. The present invention is based on a completely new viewpoint of reaction of two types of resins and one or more types of monomers, in which a radical generator and a styrenic compound are present in polyphenylene ether and a styrenic polymer, and a substantially solvent-free reaction is achieved. Below, 20
The present invention relates to a method for producing a graft copolymer consisting of polyphenylene ether and a styrene polymer by melt-kneading at a temperature range of 0 to 300° C. while applying a shear rate of 10 seconds to 1 or more.

The method of the present invention includes, in the presence of a large amount of a radical generator,
The method also includes treating a styrenic polymer under high temperature and melt-kneading, and polymerizing a styrenic compound thereon.

In conventional techniques, this has been considered to be practically undesirable because it greatly reduces the molecular weight of the styrenic polymer or extremely lowers the molecular weight of the polymer produced from the styrenic compound. By making effective use of these undesirable behaviors, and by combining it with polyphenylene ether, it contains substantially no homopolymer of polyphenylene ether, and furthermore, it does not contain gel-like polymers. Thus, we have discovered a new industrially useful production method for obtaining a graft copolymer with excellent moldability without degrading the properties of the resin. The polyphenylene ether referred to in the present invention is defined as (in the formula, R and R2 each represent an alkyl group having 1 to 4 carbon atoms or a halogen atom, and n is an integer indicating the degree of polymerization of 60 to 250
Specific examples include poly(2,6-dimethylphenylene-1,4-ether), poly(2,6-diethylphenylene-1,4-ether), Poly(2-methyl-6-n-butylphenylene-1,4-ether), Poly(2-methyl-6-promphenylene-1,4-ether), Poly(2-methyl-6-chlorophenylene-1,4-ether) ether), poly(
2,6-dichlorophenylene-1,4-ether), poly(2,6-di-n-propylphenylene-1,4-ether), and the like.

It goes without saying that a polyphenylene ether copolymer mainly having the chemical structure represented by the above general formula can also be used. Specific examples thereof include copolymers of 2,6-disubstituted phenonofur and 2,4-disubstituted phenol,
Copolymers of -disubstituted phenols and 2,3,6-trisubstituted phenols, copolymers of 2,6-dimethylphenols and 2-monosubstituted phenols, 3-monosubstituted phenols, or 4-monosubstituted phenols, etc. .

The number average degree of polymerization n of the polyphenylene ether used in the present invention is selected from the range of 60 to 250, preferably 80 to 200.

When the number average degree of polymerization is less than 60, a homopolymer of polyphenylene ether tends to remain, and when the number average degree of polymerization exceeds 250, a gel-like polymer is produced, which is the object of the present invention. It is not possible to improve molding processability, which is one of the problems, and the surface gloss of the molded product is also lowered, which is undesirable. When the polyphenylene ether is poly(2,6-dimethylphenylene-1,4-ether), the relationship between the number average molecular weight MO and (4) has been studied in detail and is expressed by the following formula: (4) = 1.47 x 10-4Mn0.85 (where (4) is the intrinsic viscosity measured in a chloroform solution at 30°C).

In this case, since the molecular weight of the repeating unit of the polymer is 120, the number average degree of polymerization n can be calculated more easily than in (5).

In the Examples described later, the measured values in (6) are used. Further, the polyphenylene ether used in the present invention is preferably a powder having a weight average particle diameter of 2 mm or less.

The styrenic polymer referred to in the present invention is polystyrene or a copolymer of styrene and a vinyl compound, where the vinyl compound accounts for 10% by weight of the styrene polymer. The following styrene copolymer.

Specific examples of the copolymer include styrene-acrylonitrile copolymer, styrene-methyl methacrylate copolymer, styrene-α-methylstyrene copolymer, styrene-maleic anhydride copolymer, and styrene-methyl methacrylate-acrylonitrile copolymer. Examples include terpolymers and copolymers of styrene and one or more of all other copolymerizable substances. The weight average molecular weight of the styrenic polymer is selected from the range of 100,000 or more, preferably 120,000 or more.

10 weight vinyl compounds that can be copolymerized with styrene? When using a styrenic polymer with a content exceeding Not only does it produce only a graft copolymer having , but also a large amount of a low molecular weight styrenic polymer. As a result, moldability is not improved and the resulting polymer has poor impact strength, making it impossible to achieve the object of the present invention. The amount of the styrenic polymer used in the present invention is practically preferably 40 to 10% by weight based on the total amount with the polyphenylene ether.
selected from the range.

The styrene compound referred to in the present invention is 90% by weight? The above is styrene, and represents a mixture containing 10% by weight or less of one or more radically copolymerizable vinyl compounds.

Specific examples of vinyl compounds that can be radically copolymerized include acrylonitrile, methyl methacrylate, α
-Methylstyrene, chlorstyrene, vinyltoluene,
Examples include maleic anhydride. In the present invention, the amount of the styrene compound is from 3 to 30 parts by weight, preferably from 5 to 20 parts by weight, based on 100 parts by weight of the mixed resin consisting of polyphenylene ether and styrene polymer. To be elected.

If the amount is less than 3 parts by weight, the graft copolymer obtained by the method of the present invention tends to have lower mechanical strength, particularly impact strength, which is not preferable.

In the present invention, the presence of a radical generator is essential for promoting the grafting reaction onto polyphenylene ether. Specific examples of compounds that can be used as radical generators include di-tertiary-butyl peroxide; tertiary-butylcumyl peroxide; dicumyl peroxide;
,5-dimethyl-2,5-di(tertiary-butylperoxy)hexane-3;2,5-dimethyl-2,5-di(tertiary-butylperoxy)hexane;tertiary-butyl Hydroperoxide; cumene hydroperoxide; permentahydroperoxide: 2,5-dimethylhex-2,5-dihydroperoxide; acetyl peroxide; octanoyl peroxide; 3,5,
5-trimethylhexanoyl peroxide; benzoyl peroxide; p-chlorobenzoyl peroxide;
Examples include α,d-bis(tertiary-butylperoxy)para-diisopropylbenzene. Two or more radical generators can also be used in combination in conjunction with changes in polymerization temperature.

The amount of the radical generator used in the present invention is as follows: In the method of the present invention, 3 to 30 parts by weight of the styrene compound is added to 100 parts by weight of the mixed resin of polyphenylene ether and styrene polymer. It is selected from the range of 0.5 to 5 parts by weight, preferably 0.8 to 4 parts by weight.

The present invention is carried out substantially without solvent.

When a solvent is present, the styrenic polymer used in the present invention produces a large amount of low molecular weight polymer that does not undergo the graft reaction, in conjunction with the fact that the reaction is carried out at a high temperature that could not be expected from the prior art. Furthermore, polymers produced from styrene-based compounds also have low graft reaction efficiency and produce large amounts of low molecular weight polymers. As a result, the properties of the resulting polymer, particularly its impact strength, are reduced, which is unfavorable for the purpose of the present invention. However, for the purpose of dissolving and adding the radical generator, etc., the amount is 5% by weight for the styrene polymer and styrene compound. It is okay to add some amount. The temperature at which the method of the invention is carried out is selected from the range 200-300°C.

At temperatures below 200°C, polyphenylene ether homopolymers tend to remain, and when producing with high productivity by shortening the reaction time, vinyl compounds such as styrene compounds tend to remain as unreacted monomers. It is undesirable because it remains.

On the other hand, temperatures exceeding 300° C. tend to produce a gel-like polymer, which is undesirable because it reduces the molding processability of the graft copolymer. The method of the present invention is 10 sec-1
It is characterized in that melt-kneading is performed while applying a shear rate higher than or equal to the above.

If melt-kneading is carried out at a shear rate below 10 sec-1, it is inevitable that the homopolymer of polyphenylene ether remains, and there is a tendency to form a gel-like polymer. The purpose of the invention cannot be achieved. The present invention may be carried out by any method as long as it can handle a molten viscous material while applying a shear rate of 10 sec-1 or more during melt-kneading, and either a batch method or a continuous method can be used. To increase productivity,
A continuous method is preferred.

Specific examples include an extruder, an internal mixer kneader, and the like. When carrying out the present invention, it is also possible to add fillers such as other polymer glass fibers, carbon fibers, carbon black, silica, plasticizers, flame retardants, etc. as long as they do not inhibit the graft copolymerization reaction. It is.

In particular, it is desirable to add a rubbery polymer to improve impact strength. The rubber-like polymer may be any polymer having a lower elastic modulus than the graft copolymer obtained by the method of the present invention, and specific examples thereof include polybutadiene, butadiene-styrene copolymer, polyethylene,
Ethylene copolymer, ethylene-propylene copolymer,
Examples include polyisoprene, polyisobutylene, polyacrylic ester, polyamide, polyester, and modified polymers thereof. The amount of the rubbery polymer added is generally a known amount for rubbery polymer-reinforced resin compositions, and is 1 to 1 parts by weight per 100 parts by weight of the resin portion consisting of polyphenylene ether and styrene polymer. 30 parts by weight is preferred. The fact that the graft copolymer obtained by the present invention does not contain a homopolymer of polyphenylene ether is due to A. FactOr et al., J. POlynlerS
cl. , 7B, 2O5 (1969),
That is, polyphenylene ether becomes insoluble in methylene chloride by forming a complex with methylene chloride, and this complex easily releases methylene chloride when heated, and polyphenylene ether becomes insoluble in methylene chloride. The obtained results are confirmed by a combined method.

Specifically, when the polymer obtained by the method of the present invention is dissolved in methylene chloride, it dissolves uniformly and does not produce precipitates, or if left for a long time, even if precipitates are formed, After thorough washing, it is confirmed that the dried polymer contains polystyrene or styrene polymer that cannot be separated. Those skilled in the art know that if 10% by weight or more of a homopolymer of polyphenylene ether remains in the polymer obtained with the composition of the present invention, it can be easily detected by the method of A,'Fact0r et al. If so, you can try again immediately.

Furthermore, the fact that the graft copolymer obtained by the present invention does not contain a homopolymer of polyphenylene ether means that a special combination of a solvent and a non-solvent is used for both the polyphenylene ether and polystyrene polymers. It can also be confirmed by compositional fractionation method. Specifically, it is possible to separate the composition by dissolving a polymer containing polyphenylene ether and polystyrene in benzene, adding n-heptane, and carefully fractionating. When the graft copolymer obtained by the method of the present invention is compositionally fractionated by this method, polystyrene that is difficult to separate is already contained in the fractionated amount of 5% by weight or less. The drawings show the composition fractionation results of a graft copolymer obtained by the method of the present invention and a mixed resin of polyphenylene ether and polystyrene as a comparative example. When using the graft copolymer of polyphenylene ether and polystyrene or styrene polymer obtained by the method of the present invention, which does not contain a polyphenylene ether homopolymer, for various purposes, it is difficult to use it alone. It can also be used in combination with other polymers.

Specific examples include polymer blends with styrene polymers such as polystyrene, styrene-acrylonitrile copolymer, styrene-methyl methacrylate copolymer, or rubber-modified styrenic resins, such as butadiene-based rubber-modified polystyrene, butadiene Examples include blends with rubber-modified styrene-acrylonitrile copolymer, acrylic rubber-modified polystyrene, acrylic rubber-modified styrene-acrylonitrile copolymer, ethylene-propylene copolymer-modified polystyrene, ethylene-methyl methacrylate copolymer-modified polystyrene, and the like. Furthermore, it is also possible to further modify the resin of the present invention by adding fillers such as glass fiber, carbon fiber, carbon black, silica, etc., various polymers, plasticizers, flame retardants, etc. Hereinafter, the method of the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.

In the examples, parts refer to parts by weight. What is weight? are shown respectively. Also, the shear rate was determined by Martelli's SPE. J.O.
urnal, pages 53-61 (June 967) (hereinafter, the same method is used).

That is, the shear rate (S) was determined based on the following formula.

Here, D is the screw diameter, N is the screw rotation speed,
h represents the depth of one screw groove. Examples 1 to 3 and Comparative Examples 1 to 2 (3) are poly(2,6
-dimethylphenylene-1,4-ether) 7009 and polystyrene (manufactured by Asahi Tau Co., Ltd., trade name Styron 69)
0) and 3009 were dry blended at low speed using a pen shell mixer.

While mixing at low speed, a mixed solution of 209 di-tertiary-butyl peroxide dissolved in 2009 styrene was added little by little. After the addition, stirring was continued at high speed for an additional 5 minutes. These compounds were melt-kneaded at 260°C (barrel temperature) using a 4011φ vented single-screw extruder, and the shear rate was changed by changing the rotational speed of the screw of the extruder to perform the graft reaction while melt-kneading. did. In Example 2, the reaction time, that is, the residence time in the extruder was 4 minutes, which was an extremely short time. Despite this, almost all unreacted styrene was volatilized from the extruder vent, and almost all of it was polymerized. 2.09 of this reaction product was dissolved in 40 d of methylene chloride and left for 3 hours. If a precipitate was formed, it was filtered, washed with methylene chloride, then methanol, and dried at 120° C. for 2 hours to obtain a polymer.
Furthermore, the amount of polystyrene in this polymer was measured by infrared absorption spectroscopy. The results are shown in Table-1. Comparative example 2 is shown in the drawing with the results of careful compositional separation using ptane.
shown with.

Comparative Example 2 is the same polyphenylene ether 7 as Example 3.
009 and polystyrene 3009, 401tm
This is a resin composition obtained by polymer blending twice at 260°C in a single-screw extruder with a φ vent. The drawings show that the graft copolymer obtained by the method of the present invention in Example 3 is a copolymer with a characteristic composition distribution of polyphenylene ether and polystyrene, and does not contain a homopolymer of polyphenylene ether. It is clear that it is a copolymer. Furthermore, the moldability of the reactants obtained in Examples 1 to 3 was evaluated, and the results shown in Table 2 were obtained.

It is clear that the reactant obtained by the method of the present invention is a polymer with excellent moldability.

Example 4 (3) is 0.48d1/9 and the average particle diameter is 0
.

Poly(2,6-dimethylphenylene-1,
7009 and the same polystyrene 3009 used in Example 1 were dry blended in a blender.

A mixed solution of 309 2,5-dimethyl-2,5-di(tertiary-butylperoxy)hexane dissolved in 2009 styrene was added to this mixture and further mixed. These mixtures were heated in a twin-screw extruder with a 30mm diameter vent to
The grafting reaction was carried out under melt-kneading while applying a shear rate of 95 sec-1 at 0°C. The residence time was 3.5 minutes. 2.09 of this reaction product was dissolved in 40 ml of methylene chloride and left to stand for 6 hours, but no precipitate was found. This reactant 10009 and polybutadiene rubber-modified polystyrene 1509 containing 40% butadiene were blended and polymer blended using an extruder to obtain a resin composition.

As Comparative Example 3, polyphenylene ether and polystyrene used in Example 4, as well as polybutadiene rubber-modified polystyrene were blended to have the same composition as the above resin composition. This blend was polymer-blended twice using an extruder to obtain a resin composition. These resin compositions were evaluated for moldability, heat distortion temperature, surface gloss of molded pieces, and molding anisotropy of molded products. The results are shown in Table-3. According to the method of the present invention, as is already clear from Examples 1 to 4, the mechanical properties and thermal properties are maintained, the molding processability is excellent, the surface gloss of the molded product is good, and the molding anisotropy is maintained. A molding material with low properties can be obtained.

Furthermore, compared to the prior art, for example, the method described in JP-A No. 50-51197, despite the addition of styrene, the method of the present invention has a significantly higher temperature and a much larger amount than normal radical polymerization. It is clear that in connection with the use of a radical generator, it can be produced with high productivity by a simple process that does not require a solvent removal step and by an extremely short reaction time. Examples 5 to 6, Comparative Example 4 A graft reaction was carried out in the same manner and under the same conditions as in Example 4, except that the amount of the radical generator was changed.

The amount of radical generator and the results are shown in Table 4. In the method of the present invention, even when other conditions are satisfied,
It is clear that the presence of a radical generator is an essential requirement. When the moldability of the reaction product obtained in Comparative Example 4 was evaluated, the melt index was 2.49/1011!
M. The copolymer obtained by the method of the present invention had significantly poor moldability.

Examples 7-8, Comparative Example 5 A graft reaction was carried out in the same manner and under the same conditions as in Example 4, except that the amount of styrene was changed, and the following results were obtained.

The amount of styrene is poly(2,6-dimethylphenylene-1,
It is expressed in parts by weight based on 100 parts by weight of the total amount of 4-ether) and polystyrene. The reactant of Comparative Example 5 was added to Example 4.
As a result of evaluating the impact strength of a resin composition obtained by polymer blending in the same manner as above, the impact strength in the (11) direction was 7.2.
1<g・Cm/I, and the impact strength in the (↓) direction is 6.
51<g・C! ! It was a molding material with significantly low impact strength.

Examples 9-10 A graft reaction was carried out in the same manner and under the same conditions as in Example 4, except that the type of radical generator was changed.

Table 6 shows the types of radical generators and the results. Examples 11-13 A graft reaction was carried out under the same method conditions as in Example 2, except that the amounts of poly(2,6-dimethylphenylene ether) and polystyrene and the temperature were changed.

The composition ratio and the results are shown in Table-7. Example 14 Polymerization of 80 parts by weight of 2,6-xylenol and 20 parts by weight of 2,4-xylenol using copper bis(acetylacetone)ethylenediimine, hexahydrate of nickel chloride, and pyridine as catalysts. The method of Example 4 was repeated using a polyphenylene ether obtained by 0.51 dj/9 and an average particle size of 1.21111.

This reaction product 2.09 was dissolved in methylene chloride 4011,
There was no precipitate after 3 hours of standing, but after 6 hours, the 7
．． 5% precipitated.

This precipitate contained 11% polystyrene.

Example 15 Using cuprous iodide and n-butylamine as a catalyst,
72 parts by weight of 2,6-dimethylphenol and 2,3,6-
(4) obtained by copolymerizing with 28 parts by weight of trimethylphenol = 0.50dj/9, average particle size 0.8
111! The method of Example 4 was repeated using the polyphenylene ether copolymer of

This reaction product 2.09 was dissolved in methylene chloride 401j,
After 3 hours of standing, 3% of the precipitate precipitated, and this precipitate contained 12% polystyrene.

Example 16 (4) was 0.52 d'/g and the average particle diameter was 0.311
poly(2,6-dimethylphenylene-1,4-ether) 7009, methyl methacrylate content 6%
Styrene-methyl methacrylate copolymer 3009
, di-tertiary-butyl peroxide 409, styrene 1
509 and 2 in a 30utφ twin-screw vented extruder.
The grafting reaction was carried out under melt-kneading at 70° C. and a shear rate of 111 sec −1 .

2.09 ml of this reaction product was dissolved in 40 d of methylene chloride.

No precipitate was observed even after 3 hours had passed.

Example 17 In the method of Example 4, styrene 19 was used instead of styrene.
0g and acrylonitrile 10f! The graft reaction was carried out using

The obtained reaction product 2.09 was dissolved in methylene chloride 407111.

After standing for 3 hours, 4% precipitate was measured, and the polymer contained 13% styrene.

A resin composition was prepared using this reaction product in the same manner as in Example 4, and the impact strength was evaluated.

As a result, the impact strength in the (11) direction was 16 kg/cm
! n, and the impact strength in the (↓) direction is 14 kg/C
! It was 11.

Comparative Example 6 In the method of Example 4, styrene 17 was used instead of styrene.
0f! and acrylonitrile 309 to carry out the graft reaction.

Obtained reactant 2.0f! was dissolved in 40 d of methylene chloride, and after standing for 6 hours, 6% of precipitate was present, but this polymer contained 9% of styrene component.

Using this reaction product, the impact strength of a resin composition obtained in the same manner as in Example 4 was evaluated. As a result, the impact strength in the (11) direction was 4.7 kg·C! ! L/CT! It was L, but (↓)
The impact strength in the direction was 1.1 kg·CIL/Cm, and it could not be used practically as a molding material.

Example 18 In Example 4, polystyrene was changed to 259, and a graft reaction was carried out under melt-kneading according to the same method and conditions as in Example 12.

2.09 of this reaction product was dissolved in 40111 methylene chloride and allowed to stand.

After 3 hours, 9% of the polymer was precipitated, and 7% of the styrene component was detected in this polymer.

[Brief explanation of drawings]

The drawing shows the results of compositional fractionation of the reactant obtained in Example 3 and the composition obtained in Comparative Example 2 using benzene/n-heptane.

Claims (1)

[Claims] 1. A radical generator and a styrene compound are present in polyphenylene ether and a styrene polymer, and 1.
A method for producing a graft copolymer consisting of polyphenylene ether and a styrene polymer by melt-kneading while applying a shear rate of 0 sec^-^1 or more. 2. Polyphenylene ether has the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ) or a copolymer mainly consisting of the above structure. 3 Polyphenylene ether is poly(2,6-dimethyl-1,
4-phenylene ether). 4 As a polyphenylene ether, the weight average particle diameter is 2
4. The method according to any one of claims 1 to 3, which uses powder having a size of mm or less. 5. The method according to any one of claims 1 to 5, wherein the styrenic polymer contains 90% or more of styrene. 6. The method according to any one of claims 1 to 5, wherein the styrenic polymer is polystyrene. 7 Styrene-acrylonitrile copolymer, styrene-methyl methacrylate copolymer, styrene-α-methylstyrene copolymer, styrene-acrylonitrile copolymer, styrene-α-methylstyrene copolymer, styrene-based polymer containing less than 10% by weight of comonomer components other than styrene
The method according to any one of claims 1 to 5, which is a chlorostyrene copolymer, a styrene-maleic anhydride copolymer, or a styrene-acrylonitrile-methyl methacrylate copolymer. 8. The method according to any one of claims 1 to 7, wherein the styrenic compound contains 90% by weight or more of styrene. 9. The method according to any one of claims 1 to 8, wherein the styrenic compound is styrene. 10 Claims 1 to 10, wherein the styrenic compound is a mixture of styrene and less than 10% by weight of one or two compounds selected from acrylonitrile, methyl methacrylate, α-methylstyrene, chlorostyrene, and maleic anhydride. The method described in any of Section 8. 11. The method according to any one of claims 1 to 9, wherein the mixing ratio of polyphenylene ether and styrene polymer is 60/40 to 90/10 on a weight basis. 12 Claims 1 to 11, wherein the amount of the radical generator present is 0.5 to 5 parts by weight based on 100 parts by weight of the resin consisting of polyphenylene ether and styrene polymer.
The method described in any of the paragraphs. 13 Claims 1 to 12, wherein the amount of the styrene compound is 3 to 30 parts by weight based on 100 parts by weight of the resin consisting of polyphenylene ether and styrene polymer.
The method described in any of the paragraphs.