KR100429275B1 - Rubber-modified styrenic resin composition and molded article thereof - Google Patents

Abstract

Rubber modified styrene resin (component (A)) and solubility parameter which consist of a styrene-type monomer and 5 to 35 weight% of soft component particle | grains, and whose swelling degree is 3-30 and an average particle diameter of 0.1-5 micrometers. (SP) is 8.45-8.70 and the rubber modified styrene resin composition which consists of a polymer (hereafter (B) component) which does not contain an aromatic vinyl compound unit in a polymer, The average of the soft component particle in the said (A) component When particle size is 0.1-2.5 micrometers, the said (B) component is more than 10 weight part with respect to 100 weight part of (A) component, and it is 250 weight part or less, and the average particle diameter of the soft component particle in the said (A) component is The rubber modified styrene resin composition whose said (B) component is 0.1-250 weight part when it is larger than 2.5 micrometers and 5 micrometers or less.

The rubber modified styrene resin composition of this invention is excellent in impact strength, oil resistance, and moldability, and the molded article which consists of a rubber modified styrene resin composition excellent in the performance calculated | required by an exterior material, a packaging material, and a foamed molded object is obtained.

Description

Rubber modified styrene resin composition and its molded product {RUBBER-MODIFIED STYRENIC RESIN COMPOSITION AND MOLDED ARTICLE THEREOF}

The present invention relates to a rubber-modified styrene resin composition excellent in impact strength and oil resistance.

It is a characteristic required for rubber modified styrene resins in the field of applications such as OA devices and home appliances, and it is excellent in the balance between workability at the time of molding, precision of finished dimensions of processed products, mechanical properties such as tensile and warping, and heat resistance. In order to improve the formability and to be used for an exterior material, the impact strength is further required. This level of demand has recently been increasing. As a method of improving impact strength, the method of adding soft components, such as a styrene-butadiene copolymer, to rubber modified styrene resin is widely known. However, since these soft components have low heat resistance of the butadiene portion in the copolymer, when they remain at a high temperature (about 180 ° C to 250 ° C) at the time of molding, a gel component is formed, and the resulting gel component remains in the molded article, so-called "water As a "material", the surface of the molded article was roughened, and there was a problem that the external appearance was lowered. Or in order to prevent these gel components from remaining as water in the molded article, it is necessary to completely purge the resin retained under high temperature. In order to completely purge the resin retained under high temperature, there is a problem in that it is purged for a long time or purged using a large amount of resin.

Moreover, when used for packaging uses, especially food packaging, oil resistance may be required more.

Also in the case of use as a shock absorbing material, it is necessary to be excellent in impact strength.

By the way, it is hard to say that the conventional rubber modified styrene resin composition is sufficient in the point which fully satisfy | fills all said requirements.

An object of the present invention is to solve the above problems and to provide a rubber-modified styrene resin composition excellent in impact strength, oil resistance and molding processability. Moreover, the objective of this invention is providing the molded article which consists of a rubber | gum modified styrene resin composition excellent in the various performance required for an exterior material, a packaging material, and a foamed molded object.

MEANS TO SOLVE THE PROBLEM The present inventors reached | attained this invention as a result of earnestly examining in order to solve the said subject. That is, one invention of this invention consists of 95-65 weight% of styrene resin and 5-35 weight% of soft component particle | grains, and the swelling degree of this soft component particle | grain is 3-30, and average particle diameter is 0.1-5 micrometers. When the rubber-modified styrene resin (hereinafter sometimes referred to as component (A)) and the solubility parameter (SP) are 8.45 to 8.70 and the polymer does not contain an aromatic vinyl compound unit in the polymer (hereinafter referred to as component (B)). The rubber-modified styrene-based resin composition of the present invention, wherein in the case where the average particle diameter of the soft component particles in the component (A) is 0.1 to 2.5 μm, the component (B) is 10 based on 100 parts by weight of the component (A). More than 250 parts by weight, and when the average particle diameter of the soft component particles in the component (A) is greater than 2.5 µm and less than 5 µm, the rubber-modified styrene system having 0.1 to 250 parts by weight of the component (B). Number The present invention relates to a composition.

Moreover, among this invention, another invention relates to the molded article which consists of the said rubber modified styrene resin composition, especially an injection molded article, an extrusion molded article, and a foam molded article.

It will be described in detail below.

Content of the soft component particle | grains in (A) component used by this invention is 5-35 weight%. If the content of the soft component particles is less than 5% by weight, the composition containing the resin is less impact strength, if more than 35% by weight is less rigid.

The soft component particle | grains in (A) component are the particle | grains of the rubbery polymer only mentioned later, or the particle | grains in which a rubbery polymer contains styrene resin. The structure is not limited, but is a single inner structure composed of, for example, a core portion made of styrene resin only and a shell portion made of a rubbery polymer containing the core portion (called a core / cell structure or capsule structure). And particles having a so-called sarami structure in which a plurality of styrene-based resin small particles are dispersed and present in a particle having a particle or a rubber particle made of a rubbery polymer. In addition, the structure of the soft component particle | grains was implemented using the transmission electron microscope similarly to the measurement of the average particle diameter mentioned later.

The styrene resin of the component (A) is a copolymer of a homopolymer of a styrene monomer or a compound copolymerizable with a styrene monomer. Examples of the styrene monomers include α-alkyl substituted styrenes such as α-methyl styrene and nuclear substituted alkyl styrenes such as p-methyl styrene. Moreover, as a compound copolymerizable with a styrene-type monomer, vinyl monomers, such as an acrylonitrile, methacrylonitrile, methacrylic acid, and methyl methacrylate, Furthermore, maleic anhydride, a maleimide, a nuclear substituted maleimide, etc. are mentioned, for example. Can be mentioned. In the case of a copolymer, content of the copolymerizable compound in a copolymer is 40 weight% or less normally as a monomeric unit of this compound, Preferably it is 30 weight% or less.

Examples of the rubbery polymer include polybutadiene, styrene-butadiene copolymers, ternary copolymers of ethylene-propylene-nonconjugated diene, and the like, and polybutadiene and styrene-butadiene copolymers are more preferable. As polybutadiene, both the high cis polybutadiene with a high cis content rate and the low cis polybutadiene with a low cis content rate can be used.

In addition, in this invention, content of the soft component particle | grains in (A) component is measured by the following method, for example. Approximately 0.5 g of rubber-modified styrene resin, which is a sample, is weighed and weighed (weight: W1), and the sample is dissolved in 50 ml of a methyl ethyl ketone / methanol mixed solvent (volume ratio 10/1) at room temperature (about 23 ° C). Let's do it. Next, the insoluble component at the time of dissolution is isolated by centrifugation, the insoluble component is dried and its weight (W2) is measured. The content of the soft component particles in the rubber-modified styrene resin is (W2 / W1) x 100 (%).

Swelling degree of the soft component particle | grains in (A) component is 3-30, Preferably it is 8-20. If the degree of swelling is too small, the impact strength of the resulting resin composition will be low, and if too large, the rigidity will be inferior.

Swelling degree of this soft component particle | grain can be calculated | required, for example by the following method. That is, about 1.0 g of rubber modified styrene resin which is a sample is melt | dissolved in 50 ml of toluene at room temperature, and is left to stand overnight. The obtained toluene solution was suspended in a centrifuge (10000 rpm x 30 minutes) to separate insoluble matters. Discard the supernatant, weigh the insolubles and set the weight to a. Next, this insoluble matter is dried in a vacuum dryer (70 ° C x 3 hours), and the weight after drying is b. Swelling degree is (a-b) / b.

The manufacturing method of (A) component can mention the method of superposing | polymerizing 1 type, or 2 or more types of styrene monomers, or 1 type, or 2 or more types of styrene monomers, and the compound copolymerizable with this in presence of a rubbery polymer. have. Examples of the polymerization method include a bulk polymerization method or a block or suspension two-stage polymerization method. Rubber-modified styrene which satisfies conditions such as the content of the soft component particles required in the present invention, the average particle diameter of the particles, the degree of swelling, and the like by adjusting the rubber polymer concentration, the stirring speed, the polymerization temperature, the polymerization time and the like during the polymerization reaction. System resins can be obtained. For example, when the rubber polymer concentration is high or the polymerization time is short, the content of the soft component particles is high, and when the stirring speed is high, the average particle size tends to be small. Moreover, when polymerization temperature is high, there exists a tendency for swelling degree to become low.

Next, the (B) component used by this invention is a polymer whose solubility parameter (SP) is 8.45-8.70 and does not contain an aromatic vinyl compound unit.

If the solubility parameter is less than 8.45 or greater than 8.70, the effect of improving the impact strength is not sufficient.

The solubility parameter here also defines the intermolecular attraction forces by Hildebrand-Scatchard's theory. Detailed explanations are described in general textbooks of polymer science, for example, "Polymer Blend, Akimoto Saburo et al., CMC, 4th Edition, 125-144 pages (1991)". In the present invention, a value obtained by a method obtained by calculation from the molecular structure proposed by Small was used. This method and theory are described in detail in the Journal of Applied Chemistry, Vol. 3, pp. 71-80 (1953). Thereby, the solubility parameter was computed using the following formula.

Fi is the molar attraction force of each constituent group such as atoms or groups of atoms, bond type (bond form) between molecules, V is molar volume, ρ is density, M is molecular weight, and in the case of polymer, molecular weight of monomer unit Indicates. The value of Fi used the small value described in the two documents. In the case of the copolymer, it was calculated using the following formula assuming that causticity was established for ρ, ∑Fi and M.

(Where f _k = ∑Fi)

Here, ρ _k , ΣFi, and M _k are the density, molar attraction force, and molecular weight of the homopolymer of the monomers constituting the copolymer, and m _k is the mole fraction of each monomer in the copolymer.

Moreover, (B) component of this invention is a polymer which does not contain an aromatic vinyl compound unit in a polymer. The composition using the polymer containing an aromatic vinyl compound unit is inferior in impact strength. An aromatic vinyl compound here is a styrene derivative, For example, (alpha)-alkyl substituted styrene, such as styrene and (alpha) -methyl styrene, nuclear substituted alkyl styrene, such as p-methyl styrene, etc. are mentioned.

As a polymer whose SP is 8.45-8.70 and does not contain an aromatic vinyl compound unit, the copolymer of ethylene with one or more vinyl monomers of unsaturated carboxylic acid, unsaturated carboxylic acid ester, or carboxylic acid vinyl is mentioned. . Examples thereof include an ethylene-unsaturated carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid ester copolymer, an ethylene-vinyl carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid ester-vinyl carboxylic acid terpolymer, ethylene and 2 And polyunsaturated copolymers comprising at least one unsaturated carboxylic acid ester. As unsaturated carboxylic acid, aliphatic unsaturated carboxylic acid is preferable and as carboxylic acid vinyl, aliphatic carboxylic acid vinyl is preferable.

Specific examples of the unsaturated carboxylic acid include acrylic acid and methacrylic acid. Specific examples of the unsaturated carboxylic acid ester include ethyl acrylate, methyl acrylate, 2-ethyl hexyl acrylate, stearyl acrylate, and glycidyl. Acrylate, methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, glycidyl methacrylate, and the like. Vinyl acetate is mentioned as a specific example of vinyl carboxylate.

Preferred examples of the copolymer of at least one vinyl monomer of unsaturated carboxylic acid, unsaturated carboxylic acid ester or vinyl carboxylic acid and ethylene used in the present invention are ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene- Methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-vinyl acetate, ethylene-methyl acrylate-glycidyl methacrylate copolymer Copolymer, ethylene-methylmethacrylate-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, and the like.

As for the ratio of the said vinyl monomer unit in a copolymer, 5 to 60 weight% is preferable. In addition, the bonding mode (for example, random, block, alternating) of the said vinyl monomer and ethylene in a copolymer is not limited at all. Alternatively, the melt flow index of the copolymer (according to JIS K7210, temperature 190 ° C., and 2.1 kgf load) is not particularly limited, but is preferably about 1 to 500 g / 10 minutes.

In the rubber-modified styrene resin composition of the present invention, the blending amount of the component (B) depends on the average particle size of the soft component particles in the component (A).

When the average particle diameter of the soft component particles in (A) component is 0.1-2.5 micrometers, the compounding quantity of (B) component is 250 weight part or less more than 10 weight part with respect to 100 weight part of (A) component, When the average particle diameter of the soft component particles in (A) component is larger than 2.5 micrometers and 5 micrometers or less, the compounding quantity of (B) component is 0.1-250 weight part with respect to 100 weight part of (A) component.

When the average particle size is 0.1 to 2.5 µm, the impact strength and oil resistance of the rubber-modified styrene resin composition obtained are not sufficient when the blending amount of the component (B) is 10 parts by weight or less. When the average particle size is larger than 2.5 µm and less than or equal to 5 µm, the impact strength and the oil resistance are not sufficient when the blending amount of the component (B) is less than 0.1 part by weight. In any case, when the compounding quantity of (B) component is more than 250 weight part, physical properties, such as rigidity, will fall and are unpreferable.

Further, in applications where rigidity or appearance is important, the resin composition has a compounding amount of (B) component of greater than 10 parts by weight and 250 parts by weight or less with respect to 100 parts by weight of the component (A) at an average particle size of 0.1 to 2.5 μm of the soft component particles. In this application, where the oil resistance or impact strength is important, the blending amount of the component (B) is 0.1 to 250% by weight based on 100 parts by weight of the component (A) when the average particle diameter of the soft component particles is larger than 2.5 µm and 5 µm or less. The dendritic resin composition is preferred. In the case of the former use, the average particle diameter of the soft component is more preferably 0.1 to 2 µm, and in the case of the latter use, the average particle diameter of the soft component particles is more preferably 2.6 to 4 µm.

In addition, the average particle diameter of soft component particle | grains is defined as follows. It is the number average particle diameter which makes the ultra-thin piece of rubber modified styrene resin, takes the transmission electron microscope photograph, measures the soft component particle diameter in a photograph, and calculates it by a following formula. The number of samples of the soft component particles is usually 200 to 500.

Ni is the particle number of particle diameter Di here.

In order to obtain the rubber-modified styrene resin composition of the present invention, a predetermined amount of each component may be dry mixed in a mixing apparatus such as a Henschel mixer, a tumbler, or a kneader such as a uniaxial or biaxial screw extruder or a Banbury mixer. What is necessary is just to heat-knead enough at the temperature of -260 degreeC, and to assemble after that.

The content of component (B) in the resin composition is obtained by, for example, making an ultra-thin section of the composition, taking a transmission electron microscope photograph thereof, and converting the composition from the area ratio of component (B) in the photo, using a spectrometer such as NMR or IR. It can confirm by the method etc. calculated | required from the absorption peak thereof.

If necessary, additives such as antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, antistatic agents, mineral oils and silicone oils can be used. These additives may be added during the dry mixing or kneading, but may be added to the polymerization step when the rubber-modified styrene resin is produced by polymerization.

The rubber modified styrene resin composition of this invention can be made into various molded articles. Examples of the molded article include injection molded articles, extrusion molded articles, foam molded articles, and the like.

There is no restriction | limiting in particular in the method of obtaining an injection molded article, It can manufacture using the injection molding machine generally used.

An extruded article can be obtained using an extrusion machine which is generally used. Although there is no restriction | limiting in particular as a method of manufacturing an extrusion molded article, T-die method etc. can be illustrated, You may extend | stretch uniaxially or biaxially by the denter method or the inflation method after extruded on a sheet | seat or a film. .

Although there is no restriction | limiting in particular as a method of foaming the rubber modified styrene resin composition of this invention to make a foam, For example,

(1) a method of melt-kneading and foaming a decomposable blowing agent and a rubber-modified styrene resin composition in an extruder,

(2) a method in which the rubber-modified styrene resin composition is melted in an extruder, and the evaporation blowing agent is directly pressed in the middle of the cylinder to knead and foam;

(3) A method of impregnating a small pellet or a piece made of a rubber-modified styrene resin composition with an evaporative blowing agent in an extruder or an aqueous suspension, and foaming the impregnated pellet or piece with water vapor.

Azodicarbon amide, trihydrazinotriazine, benzene sulfonyl semicarbazide, etc. are mentioned as a decomposition type blowing agent used here. Propane, n-butane, i-butane, n-pentane, i-pentane, hexane, heptane, a freon etc. are mentioned as an evaporation type foaming agent.

The use of the rubber-modified styrene resin composition of the present invention is suitable for the field of injection molded products, the field of extrusion molded products, and the field of molded foam products utilizing its characteristics.

For example, packaging materials, such as exterior materials, such as a weak electric machine, office equipment, a telephone, and OA equipment, food containers, etc., are concrete uses.

Moreover, the foam obtained by foaming a resin composition as what is called a buffer material which absorbs the impact from the outside applied to glass goods and various precision instrument products, and protects this product can be used.

Example

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited at all by these Examples.

The measurement and evaluation method is as follows.

(1) Moldability (with or without water)

<Injection molding>

Toshiba IS-150E was used to perform flat plate injection molding with a mold temperature of 40 ° C. and a sample shape of 150 × 90 × 2 mm. At that time, the resin was held in the cylinder at 240 ° C. for 1 hour, followed by injection molding to visually evaluate the presence or absence of water on the surface of the flat plate.

〈Extrusion molding〉

The sheet | seat of thickness 0.6mm was processed by extrusion at the resin temperature of 240 degreeC using the sheet | seat processing machine (model V65-S1000 made from Tanabe Plastic Machinery) of 65 mm (phi). At that time, the resin was held in the cylinder at 240 ° C. for 1 hour, and the sheet was extruded to visually evaluate the presence or absence of water on the sheet surface.

(2) oil resistance

The resin composition was preformed at 210 ° C. for 5 minutes and then pressurized at 50 Kg / cm ² under a condition of 5 minutes to form a press sheet of 150 mm × 150 mm × 3 mm, from which a 20 mm × 150 mm × 3 mm test piece was cut out and used for measurement. It was. For measuring oil resistance, fix one end of the test piece to the jig, apply margarine (neosoft manufactured by Seolyu Co., Ltd.) on the surface of the test piece in a state of 10 mm at a place of 100 mm from the fixed place, and at room temperature 24 After leaving still, it evaluated by the presence or absence of the stress crack which arises in a test piece. ○ No stress crack was evaluated, and stress crack was evaluated as ×.

(3) fall impact strength

A flat plate of 2 mm thickness was injection molded, and a weight of 7.5 Kg was dropped naturally from the 80 cm height on the test piece plane using a "falling-type graphic impact tester" manufactured by Toyosei Co., Ltd. Completely destroy or penetrate the specimen. The required energy at this time was obtained. The measurement temperature was 23 degreeC. In addition, the molding machine used IS-150E by Toshiba, and set it as the mold temperature of 40 degreeC, and sample shape 150 mm x 90 mm x 2 mm.

(4) Izod impact strength

The test piece obtained by injection molding was measured according to JIS K7110. Moreover, it was set as the test piece thickness 3.0mm, the notch part, and the measurement temperature of 23 degreeC.

(5) polished (surface appearance)

The flat plate of thickness 2mm was injection-molded, and the center part was measured according to the specification of 45 degree mirror glossiness measuring method of JISK7105. In addition, the molding machine used IS-150E by Toshiba, and set it as the mold temperature of 40 degreeC, and sample shape 150 mm x 90 mm x 2 mm.

(6) flexural modulus (stiffness)

The test piece obtained by injection molding was measured according to JIS K7203. The measurement temperature was 23 degreeC at this time.

Examples 1-7 and Comparative Examples 1-8

The components shown in Tables 1, 2 and 3 were melted at 220 ° C. with a 40 mmφ extruder, kneaded and granulated to obtain pellets. The obtained pellets were injection molded or press molded into test pieces or flat plates and evaluated. In addition, the components shown in Tables 1, 2, and 3 were dry mixed, extruded with an extrusion sheet processing machine, and molding processability was evaluated.

Examples 8-14 and Comparative Examples 9-12

The components shown in Tables 4 and 5 were melted at 220 ° C. with a 40 mmφ extruder and kneaded to obtain pellets. The obtained pellets were injection molded into test pieces or flat plates and evaluated. Moreover, the obtained pellet was press-molded and oil resistance evaluation was performed.

Examples 15-17 and Comparative Examples 13-15

The components shown in Table 3 were dry mixed and extruded at a resin temperature of 240 ° C. using a sheet processing machine of 65 mmφ (manufactured by Tanabe Plastic Machinery, type V65-S1000) to obtain a 0.6 mm thick resin sheet, followed by physical properties of the sheet. Evaluated. The components shown in Table 2 were melted at 220 ° C. with a 40 mmφ extruder, and kneaded together to obtain pellets. The obtained pellets were press-molded to evaluate oil resistance.

In addition, the used (A) rubber modified styrene resin was synthesize | combined as follows by the continuous block polymerization method, and the structure was shown in Table 7.

A1: A mixed liquid consisting of 80% by weight of styrene, 12% by weight of styrene-butadiene block copolymer (styrene content of 40% by weight), 5% by weight of ethylbenzene and 3% by weight of mineral oil was fed to a stirred polymerization tank, and the temperature was 140 ° C. The polymerization was carried out to a conversion rate of 37.5% under conditions of agitation speed of 35 rpm. Subsequently, the obtained liquid mixture is transferred to a fully-capable polymerization tank and polymerized therein to a conversion rate of 77%, and then the contents are transferred to a degassing tank at 240 ° C. to remove volatile components therefrom, and then the obtained polymer is transferred to a melt extruder and a pelletizer. By passing through, a pellet-shaped rubber-modified styrene resin was obtained.

A2: A mixed liquid consisting 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 fed to a stirred polymerization tank, and the conversion rate was 23% under conditions of a temperature of 140 ° C and a stirring speed of 60 rpm. Polymerized. Subsequently, the obtained liquid mixture is transferred to a fully-capable polymerization tank, polymerized to a conversion rate of 70%, and then the contents are transferred to a degassing tank at 240 ° C. to remove volatile components therefrom, and the obtained polymer is then transferred to a melt extruder and a pelletizer. It passed through the base, and obtained the rubber | gum modified styrene resin of a pellet form.

A3: A mixed liquid consisting of 88.3% by weight of styrene, 5.4% by weight of polybutadiene, 3.9% by weight of ethylbenzene and 2.41% by weight of mineral oil was fed to a stirred polymerization tank, and the conversion rate was 17% under conditions of a temperature of 140 ° C and a stirring speed of 45 rpm. Polymerized. Subsequently, the obtained liquid mixture is transferred to a full-pack polymerization tank, polymerized to a conversion rate of 71%, and then the contents are transferred to a degassing tank at 240 ° C. to remove volatile components therefrom, and then the obtained polymer is transferred to a melt extruder and a pelletizer. It passed through the base, and obtained the rubber | gum modified styrene resin of a pellet form.

A4: A mixed liquid consisting of 88% by weight of styrene, 7% by weight of polybutadiene, 3.5% by weight of ethylbenzene and 1.5% by weight of mineral oil was fed to a stirred polymerization tank, and the conversion rate was 18% under conditions of a temperature of 140 ° C and a stirring speed of 15 rpm. Polymerized. Subsequently, the obtained liquid mixture is transferred to a fully liquid polymerization tank where it is polymerized to a conversion rate of 70%, and then the contents are transferred to a degassing tank at 240 ° C. to remove volatile components therefrom, and then the obtained polymer is transferred to a melt extruder and a pelletizer. By passing through, a pellet-shaped rubber-modified styrene resin was obtained.

Moreover, the used (B) component is as follows, respectively.

B1: ethylene-methyl methacrylate copolymer (Sumitomogaku Co., Ltd., trade name Aclift WM403, methyl methacrylate content 38% by weight, melt flow index 15g / 10min),

B2: ethylene-ethyl acrylate copolymer (18 wt% ethyl acrylate content, melt flow index 7g / 10min),

B3: ethylene-vinyl acetate copolymer (Sumitomogaku Kogyo Co., Ltd. brand name Smitate RB-11, vinyl acetate content 41 weight%, melt flow index 60g / 10min),

B4: polypropylene (Sumitomo Chemical Co., Ltd., brand name noble AD571, melt flow index 0.2g / 10min),

B5: polyethylene (Sumitomo Chemical Co., Ltd., trade name Sumikasen α FZ103-0, melt flow index 0.9 g / 10 minutes),

B6: styrene-methyl methacrylate copolymer (Shin-Nitetsu Chemical Co., Ltd., trade name styrene MS200, methyl methacrylate content 20% by weight, melt flow index 0.2g / 10min),

B7: ethylene-methyl methacrylate copolymer (Sumitomo Chemical Co., Ltd., trade name Aclift WK402, methyl methacrylate content 25% by weight, melt flow index 20g / 10min),

B8: ethylene-vinyl acetate copolymer (Sumitomogaku Kogyo Co., trade name Sumate HA-20, vinyl acetate content 20% by weight, melt flow index 20g / 10min),

B9: Styrene-acrylonitrile copolymer (manufactured by Mitsubishi Santo Kasei Co., Ltd., Sanlex SAN-R, acrylonitrile content 26% by weight, melt flow index 0.9g / 10min).

The melt flow index was measured according to JIS K7210 at a temperature of 190 ° C. and a load of 2.16 Kgf. Moreover, the solubility parameter (SP) of these (B) components was shown in Table 8.

From the above results, the following can be seen.

The molded article according to the composition of the embodiment of the present invention is excellent in impact strength and oil resistance. On the other hand, those of Comparative Examples 1 and 5 to 7 having a small amount of component (B) are inferior in oil resistance and impact strength. The thing of the comparative examples 2-4 which contain a polymer whose solubility parameter is outside a prescribed range as (B) component is inferior to impact strength. The thing of the comparative example 8 which does not contain (B) component and contains (C) component is inferior to moldability and oil resistance.

In Tables 4 and 5, the compositions of Examples 8 to 14 of the present invention are excellent in impact strength, oil resistance and molding processability. On the other hand, the composition of the comparative example 9 which does not contain (B) component is inferior to oil resistance and impact strength.

The composition of Comparative Example 10 having a small average particle size of the soft component particles of component (A) is inferior in oil resistance and impact strength. The compositions of Comparative Examples 11 and 12 containing a polymer having a solubility parameter outside the prescribed range as component (B) are inferior in impact strength. Next, in Table 6, the compositions of Examples 15 to 17 of the present invention are excellent in impact strength, oil resistance and molding processability. On the other hand, the composition of Comparative Example 13 containing no component (B) is inferior in oil resistance and impact strength. The compositions of Comparative Examples 14 and 15 containing no component (B) and containing component (C) are inferior in moldability and oil resistance.

Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Comparative Example 2 Compounding (parts by weight) (A) * 1 100A1 100A1 100A1 100A1 100A1 100A1 (B) * 2 0 15B1 20B1 15B2 15B3 15B4 evaluation Molding Process Injection molding none none none none none none Extrusion none none none none none none Oil resistance × ○ ○ ○ ○ ○ Fall impact strength (J) 5.3 9.9 10.6 9.5 8.3 1.5 Izod impact strength (Kgfcm / cm ² ) 6.2 22.3 28.3 20.6 15.9 2.9 Polish(%) 98.7 97.8 99.4 97.5 97.7 93.2 Flexural modulus (Kgf / cm ² ) 20300 16700 15500 16500 16700 20000

* 1: (A) Rubber modified styrene resin

* 2: (B) Polymer shown in Table 8

Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Example 5 Example 6 Compounding (parts by weight) (A) * 1 100A1 100A1 100A2 100A2 100A2 100A2 (B) * 2 15B5 15B6 0 5B1 20B1 20B7 evaluation Molding Process Injection molding none none none none none none Extrusion none none none none none none Oil resistance ○ × × × ○ ○ Fall impact strength (J) 2.3 1.1 5.5 5.4 7.2 7.5 Izod impact strength (Kgfcm / cm ² ) 3.2 2.3 8.7 5.9 15.4 12.9 Polish(%) 94.7 95.8 96.9 96.9 96.8 93.2 Flexural modulus (Kgf / cm ² ) 19300 21700 24700 23400 18600 20000

* 1: (A) Rubber modified styrene resin

* 2: (B) Polymer shown in Table 8

Comparative Example 7 Example 7 Comparative Example 8 Compounding (parts by weight) (A) * 1 100A3 100A3 100A3 (B) * 2 0 20B1 0 (C) * 3 0 0 20C1 evaluation Molding Process Injection molding none none has exist Extrusion none none has exist Oil resistance × ○ × Fall impact strength (J) 8.4 10.3 10.1 Izod impact strength (Kgfcm / cm ² ) 9.7 15.5 9.5 Polish(%) 59.1 64.9 52.8 Flexural modulus (Kgf / cm ² ) 20900 15100 16000

* 1: (A) Rubber modified styrene resin

* 2: (B) Polymer shown in Table 8

* 3: (C) styrene-butadiene-styrene block copolymer

(C1: Butadiene content = 60%, Asahi Kasei, brand name Taffren A)

Comparative Example 9 Example 8 Example 9 Example 10 Comparative Example 10 Compounding (parts by weight) (A) * 1 100A4 100A4 100A4 100A4 100A2 (B) * 2 0 5B1 11B1 20B1 5B1 evaluation Molding Process Injection molding none none none none none Oil resistance × ○ ○ ○ × Fall impact strength (J) 9.1 8.5 10.2 12.1 5.4 Izod impact strength (Kgfcm / cm ² ) 9.0 10.6 13.1 10.4 5.9 Polish(%) 32.0 38.9 43.1 35.5 96.9 Flexural modulus (Kgf / cm ² ) 14900 13900 12700 10500 23400

* 1: (A) Rubber modified styrene resin

* 2: (B) Polymer shown in Table 8

Example 11 Example 12 Example 13 Example 14 Comparative Example 11 Comparative Example 12 Compounding (parts by weight) (A) * 1 100A4 100A4 100A4 100A4 100A4 100A4 (B) * 2 11B2 11B3 20B3 20B8 11B4 11B9 evaluation Molding Process Injection molding none none none none none none Oil resistance ○ ○ ○ ○ ○ × Fall impact strength (J) 10.0 9.3 10.0 9.8 1.1 2.1 Izod impact strength (Kgfcm / cm ² ) 13.1 12.0 9.6 9.6 3.5 3.9 Polish(%) 40.5 35.0 34.9 33.1 31.5 30.5 Flexural modulus (Kgf / cm ² ) 12800 12300 10300 10800 15300 15000

* 1: (A) Rubber modified styrene resin

* 2: (B) Polymer shown in Table 8

Comparative Example 13 Comparative Example 14 Comparative Example 15 Example 15 Example 16 Example 17 Compounding (parts by weight) (A) * 1 100A4 100A4 100A4 100A4 100A4 100A4 (B) * 2 0 0 0 3B1 11B1 25B1 (C) * 3 0 11C1 25C1 0 0 0 evaluation Molding Process Extrusion none has exist has exist none none none Oil resistance × × × ○ ○ ○ Dupont Fall Impact Strength (Kgfcm / mm) 5.3 16.5 19.9 9.3 13.8 12.2 Tensile Modulus MD 9700 8700 6800 9500 7800 5100 (Kgf / cm ²⁾ TD 8100 6200 3200 7900 5600 2600

* 1: (A) Rubber modified styrene resin

* 2: (B) Polymer shown in Table 8

* 3: (C) styrene-butadiene-styrene block copolymer

(C1: Butadiene content = 60% by weight, manufactured by Asahi Kasei, brand name Taffren A)

(A) ingredient Soft component particles A1 A2 A3 A4 Average particle size μm 0.2 0.8 1.8 2.8 weight% 27.0 15.4 17.0 24.0 Swelling degree 13.0 10.0 13.0 12.7 Morphology Single nested type Sarami Sarami Sarami

(B) ingredient B1 B2 B3 B4 B5 B6 B7 B8 B9 Density ρg / cm ³ 0.96 0.93 0.97 0.90 0.92 1.08 0.94 0.94 1.10 Molecular weight of repeating unit 38.5 32.2 38.7 42.0 28.0 103.2 34.1 32.4 83.9 ∑Fi 341 298 343 375 266 872 310 298 768 SP 8.50 8.61 8.60 8.04 8.74 9.13 8.55 8.65 10.07

Claims (11)

A rubber-modified styrene resin composed of 95 to 65% by weight of styrene resin and 5 to 35% by weight of soft component particles, wherein the soft component particles have a swelling degree of 3 to 30 and an average particle diameter of 0.1 to 5 µm (hereinafter, (A Component) and a polymer having a solubility parameter (SP) of 8.45 to 8.70 and not containing an aromatic vinyl compound unit in the polymer (hereinafter, component (B)), and the component (A) and (B) A rubber-modified styrene resin composition containing no compatibilizer for compatibilizing the component, wherein the average particle diameter of the soft component particles in the component (A) is 0.1 to 2.5 µm, When the component B) is more than 10 parts by weight and is 250 parts by weight or less, and the average particle diameter of the soft component particles in the component (A) is greater than 2.5 µm and less than or equal to 5 µm, the component (B) is 0.1 to 250 percent by weight. Mrs. rubber modified styrene resin composition. The resin composition of Claim 1 whose component (B) is a copolymer which consists of ethylene and one or more vinyl monomers of unsaturated carboxylic acid, unsaturated carboxylic acid ester, or carboxylic acid vinyl. The resin composition according to claim 2, wherein the component (B) is an ethylene-unsaturated carboxylic acid ester copolymer. The resin composition according to claim 3, wherein the component (B) is an ethylene-methyl methacrylate copolymer. The resin composition according to claim 2, wherein the component (B) is an ethylene-vinyl carboxylate copolymer. The resin composition according to claim 5, wherein the component (B) is an ethylene-vinyl acetate copolymer. The resin composition of Claim 1 whose component (B) is a copolymer which consists of ethylene and 2 or more types of unsaturated carboxylic ester. The molded article which consists of a rubber modified styrene resin composition in any one of Claims 1-7. The molded article according to claim 8, wherein the molded article is an injection molded article. The molded article according to claim 8, wherein the molded article is an extrusion molded article. The molded article according to claim 8, wherein the molded article is a foam molded article.