JP3141748B2 - Rubber-modified styrenic resin composition and molded article thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber-modified styrenic resin composition which gives a molded article having excellent surface impact strength and gloss, and to a molded article thereof. The present invention relates to a rubber-modified styrenic resin composition which provides a molded article having excellent gloss while at the same time greatly improving the surface impact strength by adding a specific polymer, and a molded article thereof.

[0002]

2. Description of the Related Art In application fields such as OA equipment and home electric appliances, it is necessary to have a good balance of workability at the time of molding, finished dimensional accuracy of the processed product, mechanical properties such as tension and bending, and physical properties such as heat resistance. Although required, the improvement of gloss and surface impact strength is further demanded, especially for exterior materials. Such demands have reached an increasingly high level in recent years. Also, when used as a packaging material, a high level of surface impact strength and appearance are required. When used as a cushioning material,
One of the essential properties to be provided is that it has excellent shock absorption. However, rubber-modified styrenic resin compositions have not always fully satisfied all the above requirements. As a technique for improving the impact resistance of rubber-modified styrenic resin, Japanese Patent Publication No. 3-4110 is disclosed.
As disclosed in JP-A No. 4, there is known a method of adding a specific amount of an organic polysiloxane and an ethylene-unsaturated carboxylic acid ester copolymer. However, the average particle diameter of the dispersed rubber particles was 0.1 to 2.5 μm, and the surface impact strength was insufficient.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide excellent surface impact strength and gloss by adding a relatively small amount of a blend, as well as excellent moldability and other physical properties.
An object of the present invention is to provide a rubber-modified styrenic resin composition excellent in performance required for an exterior material, a packaging material, and a foamed molded product, and a molded product thereof.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and have reached the present invention. That is, one invention of the present invention is the following (A)
A rubber-modified styrenic resin composition containing 100 parts by weight of the component and 0.1 to 10 parts by weight of the component (B). (A): 10 to 35% by weight of soft component particles are contained, and the average particle size of the soft component particles is 0.1 to 0.5 μm;
And the soft component particles are a single continuous phase consisting only of a styrene-based resin, and a core portion including the core portion ( occlu).
(B): ethylene-methyl acrylate copolymer, ethylene- modified styrene resin having a single occlusion structure composed of a shell portion made of a rubber-like polymer ( de- ocluded)
Len-methyl methacrylate copolymer, ethylene-ethyl
Methacrylate copolymer, ethylene-acrylic acid copolymer
Coalescence, ethylene-methacrylic acid copolymer, ethylene-methacrylate
Tyl acrylate-glycidyl methacrylate copolymer
Body, ethylene-methyl methacrylate-glycidyl meth
Acrylate copolymer, ethylene-vinyl acetate-glycidyl
One kind of poly selected from methacrylate copolymer
And a solubility parameter (SP) of 8.45 to
8.70 and a polymer which does not contain an aromatic vinyl compound unit in the polymer. Among the present invention, another invention relates to an injection-molded article obtained by using the above-mentioned rubber-modified styrene resin composition, extrusion, It relates to a molded article or a foam molded article. The details will be described below.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The rubber-modified styrenic resin (A) used in the present invention comprises one or more styrene-based monomers or one or more styrene-based monomers in the presence of a rubbery polymer. It is a rubber-modified styrene resin obtained by polymerizing a system monomer and a compound copolymerizable therewith.

The styrene monomer used as a raw material of the rubber-modified styrene resin (A) used in the present invention includes, for example, α-styrene such as styrene and α-methylstyrene.
Examples include nucleus-substituted alkylstyrenes such as alkyl-substituted styrene and p-methylstyrene. Examples of the compound copolymerizable with the styrene monomer include vinyl monomers such as acrylonitrile, methacrylonitrile, methacrylic acid, and methyl methacrylate, as well as maleic anhydride, maleimide, and a nucleus-substituted maleimide. As the rubbery polymer, examples Ebasuchi Len - butadiene copolymers, ethylene - propylene - although terpolymers of non-conjugated dienes or the like is used, in which
Also styrene Len - butadiene copolymer are preferred.

The content of the soft component particles in the rubber-modified styrenic resin (A) used in the present invention is 10 to 35% by weight.
However, if it is less than 10% by weight, the improvement of the surface impact strength is not sufficient, and if it is more than 35% by weight, physical properties other than the surface impact strength, for example, rigidity and heat resistance are undesirably reduced.
In the present invention, the content of the soft component particles in the rubber-modified styrene resin (A) is measured by the following method. Specifically, about 0.5 g of a rubber-modified styrene resin as a sample was weighed (weight: W ₁ ), and the sample was dissolved in 50 ml of a methyl ethyl ketone / methanol mixed solvent (volume ratio: 10/1) at room temperature (about 23 ° C.). Let it.
Next, the insoluble matter at the time of the dissolution is isolated by centrifugation, the insoluble matter is dried, and its weight (W ₂ ) is measured. The content of the soft component particles in the rubber-modified styrenic resin is (W ₂ / W
₁ ) It is determined by 100%. The soft component particles have an average particle size of 0.1 to 0.5 μm, preferably 0.1 to 0.3 μm. If it is less than 0.1 μm, the surface impact strength of the molded article is not sufficiently improved, and if it is more than 0.5 μm, appearance such as gloss is undesirably reduced. Here, the average particle diameter is defined as follows. An ultra-thin section of the rubber-modified styrene resin is prepared, a transmission electron micrograph thereof is taken, the particle diameter of the soft component in the photograph is measured, and calculated by the following equation.

[0008]

## EQU1 ## where average particle size = ΣniDi ² / ΣniDi where ni is the number of particles having a particle size Di.

In the present invention, the soft component particles in the rubber-modified styrenic resin (A) include a nucleus portion, which is a single continuous phase composed only of the styrene-based resin, and the core portion (oc).
It must have a single occlusion structure (also referred to as a core / shell structure or a capsule structure) constituted by a shell portion made of a rubber-like polymer that is to be formed as an occluded rubbery polymer. Otherwise, for example, in the case of a so-called salami structure in which a plurality of styrene-based resin small particles are dispersed in a continuous phase made of a rubber-like polymer, the gloss is poor. The observation of the structure of the soft component particles is performed using a transmission electron microscope as in the measurement of the average particle diameter described above. The method of synthesizing (A) the rubber-modified styrene resin in which the soft component particles have a single occlusion structure is described in, for example, Die Angewandte.
Macromolecule Chemie, 5
It can be synthesized by polymerizing styrene in the presence of a styrene-butadiene block copolymer having a styrene content of 15 to 65%, as described in Vol. 8/59, 175-198 (1977).

Next, in the present invention, (B) ethylene
-Methyl acrylate copolymer, ethylene-methyl meta
Acrylate copolymer, ethylene-ethyl methacrylate
Copolymer, ethylene-acrylic acid copolymer, ethylene-
Methacrylic acid copolymer, ethylene-methyl acrylate
Glycidyl methacrylate copolymer, ethylene-methyl
Methacrylate-glycidyl methacrylate copolymer
Body, ethylene-vinyl acetate-glycidyl methacrylate
One type of polymer selected from copolymers, having a solubility parameter (SP) of 8.45 to 8.70, and containing no aromatic vinyl compound unit is a (A) rubber-modified styrenic resin The content is 0.1 to 10 parts by weight with respect to 100 parts by weight. If the content is less than 0.1 part by weight, the effect of improving the surface impact strength is not sufficient. Physical properties are deteriorated, which is not preferable. The content of the component (B) in the composition of the present invention is as follows:
An ultrathin section of the composition is prepared, a transmission electron micrograph thereof is taken, and it can be determined by converting from the area ratio of the component (B) in the photograph. In addition, a method of obtaining from the absorption peak using a spectroscope such as NMR or IR, a method of performing fractionation using a solvent, and the like can be used. The solubility parameter (SP) of the component (B) of the present invention is 8.4.
5 to 8.70, less than 8.45 or 8.7
If it is larger than 0, the effect of improving the surface impact strength is not sufficient. Here, the solubility parameter is Hildebrand.
-Scatchard's theory defines the attractive force between molecules. Detailed explanations are given in general textbooks of polymer science such as "Polymer Blend, Saburo Akiyama
Et al. , CMC Co., Ltd., 4th printing, pages 125-144 (1991). However, this solubility parameter can be determined by a method such as a viscosity method or a swelling degree method by an experiment and the molecular structure. The values are slightly different depending on the method.Therefore, the method of calculating from the molecular structure proposed by Small is used here.This method and theory are described in "Journal of Applied Chemistry ( Journal of
Applied Chemistry), Volume 3, 71
Pp. 80 (1953) ", whereby the solubility parameter was calculated using the following equation.

[0011]

(Equation 2) Fi represents the molar attraction force of a constituent group such as an atom or atomic group constituting the molecule, a bond type, V represents the molar volume, and ρ represents the density. M indicates a molecular weight, and in the case of a polymer, indicates a molecular weight of a repeating unit (that is, a monomer unit). As the value of Fi, the value of Small described in the above two documents was used. Regarding ρ, ΣFi or M of the copolymer, ρ, の of each homopolymer of the monomer units constituting the copolymer
The sum of the values of Fi or M multiplied by the mole fraction of the monomer unit was calculated and used. The component (B) of the present invention is a polymer which does not contain an aromatic vinyl compound unit in the polymer. A composition using a polymer containing an aromatic vinyl compound unit in a polymer has poor surface impact strength.
Examples of the aromatic vinyl compound include styrene and α-
Α-alkyl-substituted styrenes such as methylstyrene, p-
Nucleus-substituted alkylstyrenes Nadogaa such as methyl styrene
I can do it.

The component (B) used in the present invention includes
Tylene-acrylic acid copolymer, ethylene-methacrylic acid
Copolymer, ethylene-methyl methacrylate copolymer,
Ethylene-ethyl methacrylate copolymer, ethylene-
Methyl acrylate copolymer, ethylene-methyl acrylate
Rate-glycidyl methacrylate copolymer, ethylene
-Methyl methacrylate-glycidyl methacrylate
Polymer, ethylene-vinyl acetate-glycidyl methacrylate
It is one type of polymer selected from the group of copolymers.
The ratio of the vinyl monomer and ethylene in the copolymer,
The solubility parameter (SP) can be appropriately determined within a range that gives a copolymer having a solubility parameter (SP) of 8.45 to 8.70. The proportion of the vinyl monomer in the copolymer is preferably 5 to 60% by weight. Further, there is no particular limitation on the bonding mode (for example, random, block, alternate) between the vinyl monomer and ethylene in the copolymer. The copolymer has a melt flow rate according to JIS K7210 at a temperature of 190.
° C, load 2.16 kgf).
About 1 to 500 g / 10 minutes is preferable. Further, in the present invention, when the organic polysiloxane is contained in an amount of 0.01 to 0.5 part by weight based on 100 parts by weight of the rubber-modified styrene resin (A), the improvement of the surface impact strength is further increased. If the amount is more than 0.5 part by weight, the effect of improving the surface impact strength is not further improved. The organic polysiloxane in the present invention generally refers to one represented by the following formula.

[0013]

Embedded image Here, R ₁ and R ₂ represent an alkyl group, an aryl group or a phenyl group. N represents an average degree of polymerization, and 10 to 15
00. Further, those having an epoxy group, amino group, carboxyl group, vinyl group, hydroxyl group, fluorine or alkoxy group introduced into the terminal or in the molecular chain may be used.

The structure of the organic polysiloxane used in the present invention may be any of a homopolymer, a random polymer, a block polymer and a graft polymer, and some of the organic groups of these organic polysiloxanes are hydroxyl groups, alkoxy groups, An organic polysiloxane substituted with a hydroxyalkyl group or the like may be used. Further, these organic polysiloxanes may be used as a mixture of two or more kinds.

Specific examples of the organic polysiloxane used in the present invention include, but are not limited to, for example, polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane. The viscosity of the organic polysiloxane is not particularly limited. However, when the viscosity is less than 10 centistokes, the volatility is large, and when the viscosity is more than 100,000 centistokes, it tends to be difficult to uniformly disperse the composition in the composition. It is preferable that the temperature is in the range of about 10 to 100,000 centistokes at 30 ° C. because it is easy to handle. The method of adding and mixing the organic polysiloxane is not particularly limited, for example,
(A) a method of adding a rubber-modified styrenic resin as a component at each stage of manufacturing, for example, a method of adding to a monomer in advance in a polymerization step, a method of adding to a polymerization system during the polymerization step,
Further, any method such as a method of adding the component (A) and the component (B) in a step of mixing and a method of adding the component in a molding step described below, or a combination thereof may be used.

In order to obtain the rubber-modified styrenic resin composition of the present invention, a predetermined amount of each component is dry-blended with a mixing device such as a Henschel mixer or a tumbler, or a single-screw or twin-screw extruder, a Banbury mixer The mixture may be sufficiently heated and kneaded at a temperature of 180 to 260 ° C. using a kneader such as the above, followed by granulation. If necessary, additives such as an antioxidant, a heat stabilizer, an ultraviolet absorber, a lubricant, an antistatic agent, and a mineral oil can be used.

An injection molded article using the rubber-modified styrene resin composition of the present invention can be obtained by using a generally used injection molding machine.

The extruded product of the rubber-modified styrene resin composition of the present invention can be obtained by using a generally used extruder. The method for extruding the rubber-modified styrenic resin composition of the present invention into an extruded product is not particularly limited. For example, a method of extruding from a T-die after melting with an extruder, or a method of extruding a sheet from an extruder. And then biaxially stretched by a tenter method or an inflation method.

The method of foaming the rubber-modified styrenic resin composition of the present invention to form a foam is not particularly limited. For example, a decomposable foaming agent and the rubber-modified styrenic resin composition are melt-kneaded by an extruder. And a method of foaming: the rubber-modified styrene resin composition is melted by an extruder, and an evaporating foaming agent is directly press-fitted from the middle of the cylinder, and kneaded.
A method of foaming; a method of impregnating small pellets or beads made of the rubber-modified styrene resin composition with an evaporating foaming agent in an extruder or an aqueous suspension, and foaming the impregnated pellets or beads with steam. Can be

The rubber-modified styrenic resin of the present invention is suitable for use in the fields of injection-molded products, extruded sheet products, and foam-formed products that take advantage of its features. That is, specific applications include exterior materials such as light electrical appliances, office equipment, telephones, and OA appliances, and packaging materials such as food containers. In addition, a foam obtained by foaming a resin composition can be used as a so-called cushioning material that absorbs external impact applied to glass products and various precision equipment products and protects the products.

[0021]

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. The measurement and evaluation methods are as follows. Items other than those described below were performed as described above. (1) Flexural modulus (rigidity) Measured according to JIS K7203. (2) Vicat softening point (heat resistance) Measured according to JIS K7206, B method. (3) DuPont type impact strength (surface impact strength) A 2 mm thick flat plate is injection-molded, and at 23 ° C, 50% destruction is performed using a device with a dirt tip diameter of 1/8 inch R and a receiving diameter of 3/16 inch R. The rate energy was measured. The molding machine used was Toshiba IS-150E, the mold temperature was 40 ° C., and the sample shape was 150 × 90 × 2 mm. The energy of the 50% destruction rate of the resin sheet was also measured at 23 ° C. using an apparatus having a dirt tip diameter of 1/8 inch R and a receiving diameter of 3/16 inch R. (4) Drop Weight Impact (Surface Impact Strength) A 2 mm-thick flat plate is injection-molded, and a weight drop of 80 cm in height and a mass of 7.5 kg is tested using a “drop weight-type graphic impact tester” manufactured by Toyo Seiki Seisaku-sho, Ltd. The test piece is naturally dropped on one plane, and the test piece is completely destroyed or penetrated by a striker provided under the weight. The energy value required for crack generation at this time was determined. The molding machine is Toshiba IS
Using -150E, mold temperature 40 ° C, sample shape 15
It was set to 0 × 90 × 2 mm. (5) Surface gloss (surface appearance) A flat plate with a thickness of 2 mm is injection molded, and the central part is JIS
It was measured according to the standard of K7105 45 degree specular gloss measurement method. The molding machine used was Toshiba IS-150E,
The mold temperature was 40 ° C. and the sample shape was 150 × 90 × 2 mm. In addition, the measurement was similarly performed for the resin sheet. (6) Tensile modulus (rigidity) Measured in accordance with JIS K7113 using a resin sheet.

Examples 1 to 7 and Comparative Examples 1 to 9 The components shown in Tables 1 to 4 were heated at 220 ° C. in a 40 mmφ extruder.
And kneaded and granulated to obtain pellets. The obtained pellet was injection molded into a test piece or a flat plate and evaluated.

Examples 11 and 12 and Comparative Example 10 The components shown in Table 5 were dry blended, and a 65 mmφ sheet processing machine (V65-S10, manufactured by Tanabe Plastic Machinery Co., Ltd.)
Extruded at a resin temperature of 240 ° C.
A resin sheet having a thickness of 1.2 to 1.5 mm was obtained. The sheet properties were evaluated. The rubber-modified styrenic resin (A) used was synthesized by a continuous bulk polymerization method as follows. -Examples 1 to 7 , 11 , 12 and Comparative Examples 1 to 6, 10
Component (A) used in Step 1 In a stirred polymerization tank, styrene 80% by weight, styrene butadiene block copolymer (styrene content 40% by weight) 1
A mixed solution consisting of 2% by weight, 5% by weight of ethylbenzene and 3% by weight of mineral oil was fed and polymerized to a conversion of 37.5% at a temperature of 140 ° C. and a stirring speed of 35 rpm. Subsequently, the obtained liquid mixture is transferred to a liquid-filled polymerization tank, where it is polymerized to a conversion rate of 77%.
Transferred to a 0 ° C. degassing tank where volatile components are removed, and then the obtained polymer is passed through a melt extruder and a pelletizer,
A pellet-shaped rubber-modified styrene resin was obtained. Component (A) used in Comparative Example 7 A mixed liquid composed of 89.8% by weight of styrene, 5.6% by weight of polybutadiene, 3.6% by weight of ethylbenzene, and 1% by weight of mineral oil was sent to the stirred polymerization tank. And temperature 1
Polymerization was carried out under the conditions of 40 ° C. and a stirring speed of 60 rpm to a conversion of 23%. Subsequently, the obtained mixed solution was transferred to a full polymerization tank where polymerization was performed to a conversion rate of 70%, and then the contents were transferred to a deaeration tank at 240 ° C. to remove volatile components, and then obtained. The polymer was passed through a melt extruder and a pelletizer to obtain a pelletized rubber-modified styrene resin. -Component (A) used in Comparative Examples 8 and 9 In a stirred polymerization tank, a mixed liquid composed of 87.4% by weight of styrene, 5.4% by weight of polybutadiene, 5% by weight of ethylbenzene, and 2.2% by weight of mineral oil was used. Send liquid, temperature 1
Polymerization was carried out under the conditions of 40 ° C. and a stirring speed of 35 rpm to a conversion rate of 20%. Subsequently, the obtained mixed solution was transferred to a full polymerization tank where polymerization was performed to a conversion rate of 70%, and then the contents were transferred to a deaeration tank at 240 ° C. to remove volatile components, and then obtained. The polymer was passed through a melt extruder and a pelletizer to obtain a pelletized rubber-modified styrene resin. The components (B) used are as follows. B1: ethylene-methyl methacrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., trade name: Acryft WM403, methyl methacrylate content 38% by weight, melt flow rate 15 g / 10 minutes), B2: ethylene-methyl methacrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd.) , Trade name Acklift WK
402, methyl methacrylate content: 25% by weight, melt flow rate: 20 g / 10 minutes), B3 : ethylene-methyl methacrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., trade name: Aklift WH303, methyl methacrylate content: 18% by weight, melt flow rate: 7 g / 10 minutes), B7 : Polypropylene (manufactured by Sumitomo Chemical Co., Ltd., trade name Noblen AD5)
71, melt flow rate 0.2 g / 10 min), B8:
Polyethylene (Sumitomo Chemical Industries, trade name Sumikasen α
FZ103-0, melt flow rate 0.9 g / 10
B9: Polymethyl methacrylate (Sumitomo Chemical Co., Ltd., trade name SUMIPEX-BMHG, melt flow rate 0.5 g / 10 min), B10: Styrene-methyl methacrylate copolymer (Nippon Steel Chemical Co., Ltd., trade name) Estyrene MS300, methyl methacrylate content 30% by weight, melt flow rate 0.2 g / 10 min), B11:
Styrene-acrylonitrile copolymer (manufactured by Mitsubishi Monsanto Kasei, trade name Sunlex SAN-R, acrylonitrile content 26% by weight, melt flow rate 0.9 g / 1)
0 minutes), and the melt flow rate was measured at a temperature of 190 ° C. and a load of 2.16 kgf according to JIS K7210. Tables 6 and 7 show the solubility parameters SP of the component (B). As the organic polysiloxane, a silicone oil manufactured by Toray Silicone, trade name SH200 (polydimethylsiloxane, 10,000 centistokes) was used.

The following can be seen from the results. All examples satisfying the conditions of the present invention show excellent results in all evaluation items. On the other hand, Comparative Example 1 containing no component (B) is significantly inferior in surface impact strength (drop weight impact, Dupont impact strength) and slightly inferior in gloss. Comparative Examples 2 to 4 in which SP has a polymer outside the specified range as component (B)
Is inferior in surface impact strength. Comparative Examples 5 and 6, in which the component (B) contains an aromatic vinyl compound unit and its SP is out of the specified range, are inferior in surface impact strength. Comparative Examples 7 to 9 having a large particle size and a salami structure are inferior in surface impact strength and gloss. Comparative Example 10, which is an extruded sheet containing no component (B), is inferior in surface impact strength and gloss.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

[0029]

[Table 5]

The explanation of the notes common to Tables 1 to 5 is shown below. * 1 (A): Rubber-modified styrene resin (styrene was used as the styrene monomer) * 2 (B): Polymer shown in Tables 6 and 7 * 3 (C): Organic polysiloxane * 4 OCC: single occlusion structure, SAL: salami structure

[0031]

[Table 6]

[0032]

[Table 7]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08L 83:04) (C08L 51/04 101: 00) B29K 25:00 105: 04 (56) References JP-A-3-220255 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 51/04 B29C 45/00 B29C 47/00 C08L 23/08 C08L 83/04 C08L 101/00 B29K 25:00 B29K 105: 04

Claims (6)

(57) [Claims] 1. A rubber-modified styrenic resin composition comprising 100 parts by weight of the following component (A) and 0.1 to 10 parts by weight of the component (B). (A): 10 to 35% by weight of soft component particles are contained, and the average particle size of the soft component particles is 0.1 to 0.5 μm;
And the soft component particles are a single continuous phase consisting only of a styrene-based resin, and a core portion including the core portion ( occlu).
(B): ethylene-methyl acrylate copolymer, ethylene- modified styrene resin having a single occlusion structure composed of a shell portion made of a rubber-like polymer ( de- ocluded)
Len-methyl methacrylate copolymer, ethylene-ethyl
Methacrylate copolymer, ethylene-acrylic acid copolymer
Coalescence, ethylene-methacrylic acid copolymer, ethylene-methacrylate
Tyl acrylate-glycidyl methacrylate copolymer
Body, ethylene-methyl methacrylate-glycidyl meth
Acrylate copolymer, ethylene-vinyl acetate-glycidyl
One kind of poly selected from methacrylate copolymer
And a solubility parameter (SP) of 8.45 to
8.70 and a polymer not containing an aromatic vinyl compound unit in the polymer 2. The resin composition according to claim 1, wherein the component (B) is an ethylene-methyl methacrylate copolymer. 3. The resin composition according to claim 1, which contains 0.01 to 0.5 parts by weight of the organic polysiloxane with respect to 100 parts by weight of the component (A). 4. An injection-molded article using the rubber-modified styrene resin composition according to claim 1, 2 or 3. 5. An extruded product using the rubber-modified styrene resin composition according to claim 1, 2 or 3. 6. A foam molded article using the rubber-modified styrene resin composition according to claim 1, 2 or 3.