JP2000248100A - Styrene-based resin composition for extrusion foaming and molded foam product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a styrene-based resin for extrusion foaming readily allowable to increase expansion ratio at the time of the extrusion foam molding and giving an extrusion molded foam product having an excellent surface property of the molded product. SOLUTION: This styrene-based resin composition comprises 100 pts.wt. styrene-based resin (A) having 0.3-0.9 dl/g reduced viscosity of a soluble part in methyl ethyl ketone, 0.1-20 pts.wt. AS-based resin (B) having 1.0-20 dl/g reduced viscosity of a soluble part in methyl ethyl ketone and 0.1-15 pts.wt. chemical foaming agent (C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ABS for extrusion foaming.
The present invention relates to a resin composition and an extruded foam molded article using the composition.

[0002]

2. Description of the Related Art Resin extruded and foamed moldings are widely used as house interior members, and vinyl chloride resin is mainly used as the resin for reasons such as moldability. However, in recent years, an environmentally friendly alternative resin has been desired over a vinyl chloride resin. Examples of the substitute resin include olefin resins such as polyethylene and polypropylene, and styrene resins such as polystyrene and ABS resin. Among the above alternative resins, olefin-based resins are crystalline and therefore have a narrow extrusion foaming process width, so that extrusion foaming is difficult. Styrene resin is relatively easy to extrude and foam compared to olefin resin, and ABS resin is suitable among styrene resins, but the gas pressure of the blowing agent overcomes the viscosity of the molten resin, Destroy the membrane. As a result, there are drawbacks in that the surface of the extruded foam molded article is rough, and it is difficult to obtain a foam having a uniform foam cell structure, and the expansion ratio cannot be easily increased.

[0003]

SUMMARY OF THE INVENTION The present invention does not provide a styrene resin for extrusion foaming, which can easily increase the expansion ratio at the time of extrusion foam molding and gives an extruded foam molded article having excellent surface properties of the molded article. This was done to solve the problem.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made intensive studies, and as a result, have found that the reduced viscosity of the methyl ethyl ketone soluble component is 0.3 to 0.9 dl / g. Extrusion foam molding having high expansion ratio during extrusion foam molding and excellent surface properties of the molding by adding an AS-based resin having a reduced viscosity of methyl ethyl ketone-soluble component of 1.0 to 20 dl / g to the resin. Have been found, and the present invention has been completed. That is, the present invention relates to a styrene resin (A) 1 having a reduced viscosity of methyl ethyl ketone-soluble component of 0.3 to 0.9 dl / g.
A having a reduced viscosity of 1.0 to 20 dl / g of methyl ethyl ketone-soluble component with respect to 00 parts (parts by weight, hereinafter the same).
0.1 to 20 parts of S-based resin (B), (C) chemical foaming agent
Styrene resin composition (Claim 1), wherein the styrene resin (A) is an ABS resin, wherein the styrene resin composition is an ABS resin. The present invention also relates to an extruded styrene resin molded article obtained by extrusion molding the styrene resin composition according to claim 1 or 2.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The styrene resin (A) used in the present invention contains 100 to 60% of an aromatic vinyl monomer.
(% By weight, the same applies hereinafter) Further, 90 to 60%, particularly 80 to 60% is contained, and monomers other than the aromatic vinyl monomer are 0 to 40%, further 10 to 40%, especially 20 to 40%. 4
It is a polymer containing 0% or a part of the above monomers replaced with other monomers.

Examples of the aromatic vinyl monomer unit include units derived from styrene, α-methylstyrene, p-methylstyrene, chlorostyrene, bromostyrene, vinylnaphthalene and the like. These may be used alone or in combination of two or more.
Among them, α-methylstyrene is particularly preferred from the viewpoint of heat resistance.

Examples of monomers other than the aromatic vinyl compound include, for example, (meth) acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate. Vinyl cyanide compounds such as esters, acrylonitrile, methacrylonitrile, maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-butylmaleimide, N-phenylmaleimide, N- (p-methylphenyl) maleimide And maleimide-based compounds. These may be used alone or in combination of two or more. Among these, acrylonitrile is particularly preferred in terms of impact resistance, thinner resistance, and oil resistance.

[0008] Other polymers may also be added to this. Examples of other polymers include a rubber-like elastic material for imparting impact resistance to the obtained molded article, and an engineering plastic for imparting impact resistance, heat resistance, thinner resistance, and oil resistance. Specific examples of the rubber-like elastic body include diene rubbers such as polybutadiene, butadiene-styrene copolymer (SBR), butadiene-acrylonitrile copolymer (NBR), butadiene-acrylate copolymer, and styrene-propylene. Examples include olefin rubbers such as copolymer (EPR) and ethylene-propylene-non-conjugated diene copolymer (EPDM), acrylic rubbers such as polybutyl acrylate and poly 2-ethylhexyl acrylate, and silicone rubbers. These may be used alone or in combination of two or more. Among them, polybutadiene is particularly preferred from the viewpoint of impact resistance.

When the styrene resin (A) contains the rubber-like elastic material, the content is 5 to 70%, preferably 10 to 70%.
Preferably it is 60%. When the content of the rubber-like elastic body is less than 5%, the effect of improving the impact resistance decreases, and when it exceeds 70%, the rigidity of the molded article obtained from the resin composition becomes too low. I do.

In the case where the styrene resin (A) contains a graft copolymer obtained by graft copolymerizing a graft component such as a vinyl monomer with the rubber-like elastic material, the graft component may be used. Is not treated as a part of the other polymer replaced, but is treated as the aromatic vinyl monomer unit or a monomer unit other than the aromatic vinyl monomer.

Specific examples of the engineering plastic include, for example, polycarbonate, polyamide, polybutylene terephthalate, polyethylene terephthalate and the like. These may be used alone or in combination of two or more. Among them, polycarbonate is preferable in terms of impact resistance and heat resistance.

The reduced viscosity of the methyl ethyl ketone soluble portion of the styrene resin (A) is 0.3 to 0.9 dl / g, preferably 0.4 to 0.8 dl / g. When the reduced viscosity is less than 0.3 dl / g, impact resistance, thinner resistance, oil resistance and the like are reduced, and when it is more than 0.9 dl / g, extrudability is reduced.

Specific examples of the styrene resin (A) include:
For example, general (GS) polystyrene, impact resistance (H
I) Polystyrene, an AS resin which is a copolymer of styrene and acrylonitrile, an ABS resin made of styrene-butadiene-acrylonitrile, and a heat-resistant ABS in which part or most of styrene of the ABS resin is replaced with α-methylstyrene or maleimide or the like. ABS resin such as (heat resistant) AES resin and (heat resistant) AAS resin in which butadiene of ABS resin is replaced with ethylene-propylene rubber or polybutyl acrylate, etc., butadiene rubber of ABS resin is made of silicone rubber, silicone-acryl composite (Heat-resistant) ABS resin replaced with rubber. These may be used alone or in combination of two or more. Among these, an ABS resin is preferable, and an ABS resin composed of styrene-butadiene-acrylonitrile is particularly preferable in terms of impact resistance, thinner resistance, and oil resistance.

The above-mentioned ABS resin usually contains 5 to 40%, preferably 10 to 25% of acrylonitrile units, 5 to 70%, preferably 10 to 60% of butadiene units and 40 to 80%, preferably 50% of styrene units. ~ 70%
It contains.

The method for producing the styrenic resin (A) is not particularly limited, and examples thereof include ordinary emulsion polymerization, suspension polymerization, and solution polymerization. When the styrene-based resin (A) contains the rubber-like elastic body, it is easy to control the particle size of the rubber-like elastic body, so that the molded article has excellent impact resistance and gloss. Is preferred. Further, in the presence of the rubber-like elastic latex such as polybutadiene, ethylene-propylene rubber, polybutyl acrylate, and silicone rubber, a product obtained by graft copolymerization of a vinyl monomer or the like is subjected to salting out coagulation. May be manufactured. Further, a latex of two or more kinds of polymers obtained separately may be mixed, and the mixture may be simultaneously subjected to salting out and coagulation, for example.

The AS resin (B) used in the present invention comprises:
Acrylonitrile unit 5-40%, further 20-30
%, Aromatic vinyl compound unit 95 to 60%, and further 8
0 to 70%, 0 to 30% of monomer units other than acrylonitrile units and aromatic vinyl compound units, and more preferably 0 to 70%.
It is a polymer containing 20%. If the acrylonitrile unit is less than 5%, the molded article obtained from the resin composition tends to have reduced impact resistance and thinner resistance, and
If it exceeds 0%, the thermal stability tends to decrease.
Further, when the aromatic vinyl compound unit is less than 60%, the extrudability of the obtained resin composition is reduced, and the
When the ratio exceeds the above range, the impact resistance and the thinner resistance of the molded article obtained from the resin composition tend to decrease. In addition, a monomer unit other than the acrylonitrile unit and the aromatic vinyl compound unit is often used to improve extrusion moldability and heat resistance.

Examples of the aromatic vinyl compound unit include the same units as those described for the styrene resin (A).

The monomer units other than the acrylonitrile unit and the aromatic vinyl compound unit include, for example, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate and butyl methacrylate. ) Acrylates, maleimide, N-methylmaleimide, N-ethylmaleimide,
N-propylmaleimide, N-butylmaleimide, N-
Examples include units derived from maleimide compounds such as phenylmaleimide and N- (p-methylphenyl) maleimide. These may be used alone or in combination of two or more. Among them, styrene is preferred from the viewpoint of impact resistance and thinner resistance, acrylonitrile is preferred from the viewpoint of thinner resistance and impact resistance, and butyl acrylate is preferred from the viewpoint of impact resistance.

The reduced viscosity of the methyl ethyl ketone soluble portion of the AS resin (B) is 1.0 to 20 dl / g, preferably 3 to 18 dl / g. The reduced viscosity is 1.0 dl /
If the amount is less than 20 g, the extrusion foaming moldability is not improved, and 20 d
If it exceeds 1 / g, an extruded foam molded article having excellent surface appearance of the molded article cannot be obtained.

Specific examples of the AS resin (B) include an AS resin which is a copolymer of acrylonitrile and styrene;
A heat-resistant AS resin in which part or most of styrene of AS resin is replaced with α-methylstyrene or maleimide, etc., and an AS resin in which part or most of acrylonitrile and styrene are replaced with (meth) acrylate or the like. Base resin and the like. The method for producing the AS-based resin (B) is not particularly limited, and examples thereof include ordinary emulsion polymerization, suspension polymerization, and solution polymerization. The resin may be separated, for example, by coagulation of a vinyl monomer and salting out and coagulating.

Further, the latex may be produced by mixing latexes of two or more kinds of polymers obtained separately and coagulating them by salting out simultaneously. The chemical blowing agent (C) used in the present invention includes azodicarbonamide, p, p'-oxybisbenzenesulfonyl semicarbazide, p-toluenesulfonyl semicarbazide, trihydrazide triazine,
Barium azodicarboxylate, N, N'-dinitropentamethylenetetramine, sodium hydrogen carbonate, and the like used for foaming in general thermoplastic resins are listed. The styrene-based resin composition of the present invention is a styrene-based resin composition for extrusion foaming, which can easily increase the expansion ratio during extrusion foam molding and provides an extruded foam molded article having excellent surface properties of the molded article. 0.1 to 20 parts, preferably 0.2 to 15 parts, more preferably 0.3 to 10 parts of AS resin (B) and 100 parts of resin (A), and 0.1 parts of chemical foaming agent (C). ~ 15 parts, preferably 0.2 ~ 1
It is a resin composition obtained by adding 0 parts, more preferably 0.3 to 8 parts. When the amount of the AS-based resin (B) is less than 0.1 part, the surface properties of the extruded foamed molded product are not improved,
If the amount exceeds 20 parts, the effect is saturated and uneconomical, and the impact strength of the extruded foamed molded article is rather reduced.

The styrenic resin composition of the present invention has a lubricating agent, an antioxidant, an alkali metal hydroxide or carbonate, a rigidity, for the purpose of improving moldability without impairing the effects of the present invention. For the purpose of improving, wood flour, talc, mica, glass fiber, carbon fiber and, if necessary, UV absorbers, light stabilizers, pigments for the purpose of improving weather resistance,
One or more plasticizers may be used.

The styrene resin composition may be used as a compound by mixing the styrene resin (A) and the AS resin (B) in powder, flake or pellet form with a Henschel mixer. Further, it may be melt-extruded with a single-screw or multi-screw extruder and pelletized for use.

The resin composition of the present invention can be molded by a known method. For example, the resin composition of the present invention is applied to an extruder using a usual extruder equipped with a sizing and a die having a desired shape. It is charged, extruded and foamed at a cylinder temperature usually set at 150 to 250 ° C., formed into a target shape by placing it under vacuum with a sizing device, and the target object is obtained by a method of taking up the foam with a take-up device. Can be easily obtained.

[0025]

EXAMPLES Examples and comparative examples of the present invention will be shown below, but the present invention is not limited thereto.

The evaluation methods in this example and comparative examples are summarized below. (Reduced viscosity) The obtained powdery resin was dissolved in methyl ethyl ketone at 23 ° C for 12 hours, and then centrifuged.
The soluble matter was precipitated with methanol. The precipitate was dried with a vacuum drier to obtain a sample. N,
A 0.3% solution of N-dimethylformamide was prepared and measured at 30 ° C. with a Ube-Rohde viscometer. (Evaluation of extrusion foaming molding) A styrene resin (A), an AS resin (B) and a chemical foaming agent were mixed with a Henschel mixer,
Small single screw extruder (cylinder diameter φ20 mm, L / D: 26, CR: 2.
7), using a die having an extrusion outlet shape shown in FIG.
To obtain a strip-shaped extruded foam molded article. (Surface properties) The surface of the obtained extruded foam molded article was visually observed and evaluated according to the following criteria.

：: The surface is uniform.

X: The surface is non-uniform (has irregularities). (Shape) The cross-sectional shape of the obtained extruded foam molded article was visually observed and evaluated according to the following criteria.

：: The target sectional shape is almost the same as that of FIG.

×: Other than that. (Foamability) When the target foaming ratio (depending on the specific gravity) was 100%, the case where foaming was 90% or more was evaluated as ○, and below it, as ×. Expansion ratio = (actual expansion ratio / target expansion ratio) × 100
(%) (Example 1) A polymerization vessel equipped with a stirrer was charged with 250 parts of water and 2 parts of sodium alkylbenzenesulfonate. After nitrogen substitution, the temperature was raised to 70 ° C. Further, after adding 0.2 parts of potassium persulfate, α-methylstyrene 6
5 parts, acrylonitrile 30 parts, styrene 5 parts, a monomer mixture consisting of t-dodecyl mercaptan 0.3 parts,
It was added dropwise at a polymerization temperature of 70 ° C. continuously over 7 hours. After completion of the dropwise addition, the polymerization temperature was raised to 75 ° C., and stirring was continued for 1 hour to terminate the polymerization, thereby obtaining a latex of the copolymer (I). The polymerization conversion was 98%. Separately, 280 parts of water and a weight average particle size of 0.30 μm were separately placed in a polymerization vessel equipped with a stirrer.
m, 60 parts of polybutadiene latex having a gel content of 90% (in terms of solid content) were charged, and the temperature was raised to 70 ° C. after nitrogen substitution. After adding 0.1 part of potassium persulfate,
A monomer mixture composed of 12 parts of acrylonitrile and 28 parts of styrene was continuously dropped at a polymerization temperature of 70 ° C. over 5 hours. After completion of the dropping, stirring was continued at 75 ° C. for 1 hour, and then the polymerization was terminated to obtain a graft polymer (II) latex. The polymerization conversion was 98% and the graft ratio was 40%. Copolymer (I) and graft polymer (II) are
1 (weight ratio, solid content) was mixed with the latex as it was.
The obtained mixture was salted out with calcium chloride, washed, filtered and dried to obtain a powdery styrene resin (1). The obtained styrene resin (1) had a reduced viscosity of 0.61 dl / g. On the other hand, 250 parts of water and 2 parts of sodium alkylbenzenesulfonate were charged into a polymerization vessel equipped with a stirrer, and after replacing with nitrogen, the temperature was raised to 70 ° C. After 0.2 parts of potassium persulfate was added, a monomer mixture consisting of 30 parts of acrylonitrile and 70 parts of styrene was dropped at a polymerization temperature of 70 ° C. continuously over 7 hours. After the completion of the dropwise addition, the polymerization temperature was set to 75 ° C., and stirring was continued for 1 hour to terminate the polymerization to obtain a latex of the AS resin (1). The polymerization conversion was 98%. The latex of the AS resin (1) is salted out with calcium chloride, washed,
After filtration and drying steps, a powdery AS-based resin (1) was obtained. The resulting AS resin (1) had a reduced viscosity of 3.3 dl / g.

Next, 3.0 parts of the AS-based resin (1) and 100 parts of the styrene-based resin (1) were set at a target expansion ratio of 1.8, and the chemical blowing agent (1) azodicarbonamide (Vinihole AC-3) was used. 2.0 parts, manufactured by Eiwa Chemical Co., Ltd., phosphorus-based stabilizer (ADK STAB HP-10, Asahi Denka Kogyo Co., Ltd.)
0.3 parts, phenolic stabilizer (ADK STAB AO)
-20, manufactured by Asahi Denka Kogyo Co., Ltd.), 0.5 parts of ethylenebisstearylamide as a lubricant, and 1.0 part of calcium hydroxide (Super Microstar, Maruo Calcium) as a hydroxide of an alkali metal. The mixture was added and mixed with a Henschel mixer to obtain a powder compound (1).
Table 1 shows the results of the extrusion evaluation.

Example 2 Example 2 was repeated except that the amount of the AS resin (1) used was changed from 3.0 parts to 5.0 parts. Table 1 shows the results of the extrusion evaluation.

Example 3 In place of 3.0 parts of AS resin (1), AS resin (2) produced by the following method was used.
The procedure was performed in the same manner as in Example 1 except that 0 part was used. Table 1 shows the results of the extrusion evaluation. (Production of AS resin (2)) Water 2 was added to a polymerization vessel equipped with a stirrer.
50 parts and sodium alkylbenzene sulfonate 2
The mixture was charged and replaced with nitrogen, and then heated to 70 ° C.
After 0.1 part of potassium persulfate was further added, a monomer mixture composed of 20 parts of acrylonitrile, 70 parts of styrene, and 10 parts of butyl acrylate was continuously added dropwise at a polymerization temperature of 70 ° C. for 7 hours. After the completion of the dropwise addition, the polymerization temperature was set to 75 ° C., and stirring was continued for 1 hour to terminate the polymerization to obtain a latex of the AS resin (2). The polymerization conversion was 98%. The latex of the AS-based resin (2) was salted out with calcium chloride, and washed, filtered and dried to obtain a powdery AS-based resin (2). The obtained AS resin (2) had a reduced viscosity of 5.0 dl / g.

(Example 4) The procedure of Example 1 was repeated, except that 3.0 parts of the AS resin (1) was replaced by 0.5 part of the AS resin (3) produced by the following method. . Table 1 shows the results of the extrusion evaluation. (Production of AS resin (3))
50 parts and sodium alkylbenzene sulfonate 2
The mixture was charged and replaced with nitrogen, and then heated to 70 ° C.
Further, after 0.1 part of potassium persulfate was added, a monomer mixture composed of 25 parts of acrylonitrile and 75 parts of styrene was dropped at a polymerization temperature of 70 ° C. continuously over 7 hours. After the completion of the dropwise addition, the polymerization temperature was set to 75 ° C., and stirring was continued for 1 hour to terminate the polymerization to obtain a latex of the AS resin (3). The polymerization conversion was 97%. AS resin (3)
The latex was salted out with calcium chloride, washed, filtered and dried to obtain a powdery AS-based resin (2). The obtained AS resin (3) has a reduced viscosity of 16.7 d.
1 / g.

Example 5 A styrene resin (2) produced by the following method was used in place of the styrene resin (1), and 3.0 parts of the AS resin (1) was replaced with 5. 0
The procedure was performed in the same manner as in Example 1 except for using the parts. Table 1 shows the results of the extrusion evaluation. (Production of styrene resin (2)) Styrene resin (1)
Except that the monomer mixture of copolymer (I) was changed to 23 parts of phenylmaleimide, 20 parts of acrylonitrile and 57 parts of styrene, and copolymer (II) was used instead of copolymer (I). The powdery styrene resin (2) was obtained in the same manner as in the styrene resin (1). The polymerization conversion of the copolymer (II) was 98%. The obtained styrene resin (2) had a reduced viscosity of 0.53 dl / g.

Example 6 A styrene resin (3) produced by the following method was used in place of the styrene resin (1), and an AS resin (2) was used in place of the AS resin (1). Other than that, it carried out similarly to Example 1. Table 1 shows the results of the extrusion evaluation. (Production of styrene resin (3)) Styrene resin (1)
The ratio of the copolymer (I) to the graft polymer (II) is 1:
Except having changed to 2, it carried out similarly to the styrene resin (1), and obtained the powdery styrene resin (3).

(Example 7) Chemical foaming agent (1) Chemical foaming agent (2) Sodium bicarbonate (Cerbon SC) instead of vinylol AC-3 (manufactured by Eiwa Kasei Kogyo Co., Ltd.) with a target foaming ratio of 1.8. -K, manufactured by Eiwa Chemical Industry Co., Ltd.) 2.0
The procedure was performed in the same manner as in Example 1 except for using the parts. Table 1 shows the results of the extrusion evaluation.

(Comparative Example 1) The same procedure as in Example 1 was carried out except that the AS resin (1) was not used. Table 1 shows the results of the extrusion evaluation.

(Comparative Example 2) The procedure of Example 1 was repeated, except that 3.0 parts of the AS resin (1) was replaced by 15 parts of the AS resin (4) produced by the following method. Table 1 shows the results of the extrusion evaluation. (Production of AS resin (4)) Water 2 was added to a polymerization vessel equipped with a stirrer.
50 parts and sodium alkylbenzene sulfonate 2
The mixture was charged and replaced with nitrogen, and then heated to 70 ° C.
After addition of 0.2 part of potassium persulfate, a monomer mixture comprising 30 parts of acrylonitrile, 70 parts of styrene and 0.4 part of t-dodecylmercaptan was added at a polymerization temperature of 7 parts.
It was added dropwise at 0 ° C. continuously over 7 hours. After the completion of the dropwise addition, the polymerization temperature was set to 75 ° C., and stirring was continued for 1 hour to terminate the polymerization, thereby obtaining a latex of AS resin (4). The polymerization conversion was 98%. The latex of the AS resin (4) was salted out with calcium chloride, followed by washing, filtration and drying steps to obtain a powdery AS resin (4). The resulting AS resin (4) had a reduced viscosity of 0.58 dl / g.

(Comparative Example 3) AS resin (5) 0.0 produced by the following method in place of 3.0 parts of AS resin (1) 0.0
The procedure was performed in the same manner as in Example 1 except that 5 parts were used. Table 1 shows the results of the extrusion evaluation.

(Production of AS Resin (5)) A polymerization vessel equipped with a stirrer was charged with 250 parts of water and 2 parts of sodium alkylbenzenesulfonate, and the temperature was raised to 70 ° C. after nitrogen substitution. Further, after adding 0.05 parts of potassium persulfate, a monomer mixture consisting of 25 parts of acrylonitrile and 75 parts of styrene was dropped continuously at a polymerization temperature of 70 ° C. over 7 hours. After the completion of the dropwise addition, the polymerization temperature was brought to 75 ° C,
Stirring was continued for 1 hour to terminate the polymerization to obtain a latex of AS resin (5). The polymerization conversion was 97%. AS
The latex of the resin (5) is salted out with calcium chloride,
After washing, filtration and drying, a powdery AS-based resin (5) was obtained. The obtained AS resin (4) had a reduced viscosity of 21.6 dl / g.

(Comparative Example 4) The same procedure as in Example 1 was carried out except that 5.0 parts of the AS resin (5) was used instead of 3.0 parts of the AS resin (1). Table 1 shows the results of the extrusion evaluation.

(Comparative Example 5) The same procedure as in Example 5 was carried out except that the AS resin (1) was not used. Table 1 shows the results of the extrusion evaluation.

(Comparative Example 6) A procedure was performed in the same manner as in Example 5 except that the AS resin (1) was changed from 5.0 parts to 0.05 part. Table 1 shows the results of the extrusion evaluation.

(Comparative Example 7) A procedure was performed in the same manner as in Example 5 except that the AS resin (1) was changed from 5.0 parts to 12 parts.
The results of the extrusion are shown in Table 1.

(Comparative Example 8) The same procedure as in Example 6 was carried out except that the AS resin (2) was not used. Table 1 shows the results of the extrusion evaluation.

(Comparative Example 9) The procedure of Example 6 was repeated, except that 0.05 parts of the AS resin (4) was used instead of 3.0 parts of the AS resin (2). Table 1 shows the results of the extrusion evaluation. As described above, the amount of the foaming agent used is the target foaming ratio of 1.8 times.

[0048]

[Table 1] As is clear from the results in Table 1, it can be seen that the styrene-based resin composition of the present invention has a large expansion ratio at the time of extrusion foam molding and has excellent surface properties of the molded article.

[0049]

The extruded foam molded article of the present invention is excellent in the surface properties of the molded article, provides a desired expansion ratio, and can be suitably used as an interior member of a house.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an outlet shape of a mold used in extrusion foam molding.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) (C08L 55/02 25:12) F term (reference) 4F074 AA13 AA32 AA98 BA03 BA13 CA22 DA02 DA50 4J002 BC011 BC031 BC041 BC061 BC062 BC071 BC092 BC111 BH011 BH012 BN061 BN121 BN151 BN171 DE206 EQ016 EQ026 EQ036 ES006 EV286 FD326 GL00

Claims (3)

[Claims] 1. A styrene resin 1 having a reduced viscosity of (A) methyl ethyl ketone-soluble component of 0.3 to 0.9 dl / g.
(B) 0.1 to 20 parts by weight of an AS resin having a reduced viscosity of 1.0 to 20 dl / g, and (C) 0.1 to 15 parts by weight of a chemical foaming agent. A styrenic resin composition obtained by adding parts. 2. The styrene resin composition according to claim 1, wherein the styrene resin (A) is an ABS resin. 3. An extruded styrene resin molded article obtained by extruding the styrene resin composition according to claim 1 or 2.