TWI496830B - Rubber modified styrene-based resin, preparation thereof and the molding product made therefrom. - Google Patents

Description

Rubber modified styrene resin, preparation method thereof and preparation thereof Molded product

The present invention relates to a rubber-modified styrene-based resin, and more particularly to a rubber-modified styrene-based resin which has good processability and allows a molded article to be obtained to have excellent mechanical properties.

The raw materials of plastic molded articles such as electrical equipment and household goods are generally rubber-modified styrene resins or polycarbonate resins (Polycarbonate Resin). Among them, rubber modified styrene resin, such as Acrylonitrile-Butadiene-Styrene Resin (ABS), has the advantages of easy molding, and the molded article has high surface hardness. Excellent properties such as good chemical resistance, and therefore rubber-modified styrene-based resins have been widely used in various fields.

However, as consumers' demands for impact strength and mechanical properties of molded articles are increasing, rubber-modified styrenic resins still need to be continuously improved to meet market demands.

In addition, in order to improve the appearance of the gate of the injection molded article, and to adopt fully automated production, the processing and molding industry is gradually injection molding by means of a pin gate. The pinhole gate is extremely small due to the small hole. The resin melt having a high viscosity does not easily flow through the pores to be molded, and therefore, it is necessary to improve the fluidity of the rubber-modified styrene resin to improve the problem. On the other hand, when a molded article of a rubber-modified styrene-based resin is produced by an extrusion molding method, the rubber-modified styrene-based resin is placed in a kneading extruder and melt-kneaded, and then passed through A die extrusion molded product; however, in order to facilitate the extrusion molding process and further increase the productivity thereof, the processing properties (such as fluidity and discharge amount) of the rubber-modified styrene resin are ) is even more demanding.

At present, the way to improve the rubber-modified styrene resin often fails to improve the product properties and improve the processing convenience. For example, the processing properties of the rubber-modified styrene resin are improved, but the mechanical properties are not good, so how to process A balance between nature and mechanical properties is an important topic that has been widely studied.

Accordingly, a first object of the present invention is to provide a rubber-modified styrene-based resin which has both good processing properties and which can provide a molded article with good mechanical properties.

Thus, the rubber-modified styrenic resin of the present invention comprises: 76% by weight to 86% by weight of the continuous phase formed by the copolymer component (A), and 14% by weight to 24% by weight of the rubber particle component (B) The dispersed phase formed. Wherein the copolymer component (A) is a styrene-acrylonitrile-based copolymer (A ₁ ); the rubber particle component (B) comprises rubber particles (B ₁ ) having a non-occlusive structure, and has a occlusion The rubber particles of the structure (B ₂ ); and the Z average molecular weight Mz×10 ^{-4 of} the rubber modified styrene resin measured by colloidal permeation chromatography, and the rubber change measured at a temperature of 220 ° C and a load of 10 kg The ratio of the melt flow index MI of the styrene-based resin Mz × 10 ^-4 /MI is less than 18.

Therefore, a second object of the present invention is to provide a molded article.

Thus, the molded article of the present invention is obtained by molding a rubber-modified styrene resin as described above.

Accordingly, a third object of the present invention is to provide a process for preparing the above rubber-modified styrene resin.

Thus, a method for preparing the rubber-modified styrenic resin of the present invention comprises the steps of: comprising 18% by weight to 25% by weight of the emulsion polymerized rubber graft copolymer (I) and 5% by weight to 35% by weight of the block polymeric rubber The copolymer (II) and the copolymer mixture of 40% by weight to 75% by weight of the solution-polymerized ethylene-based copolymer (III) are kneaded.

The invention has the effect that the rubber modified styrene resin of the invention is prepared by the method comprising the emulsion polymerization rubber graft copolymer (I), the bulk polymer rubber graft copolymer (II), and the solution polymerization ethylene copolymerization. The mixture of the substance (III) is subjected to a kneading treatment, and the content of the copolymer component (A) and the rubber particle component (B) of the rubber-modified styrene resin is controlled, and the rubber is modified with the benzene. The ethylene-based resin has an Mz × 10 ^-4 /MI of less than 18, and the rubber-modified styrene-based resin has good processing properties (melt flow index and discharge amount), and the obtained molded article also has excellent mechanical properties. (impact strength and hot and cold cycle).

The contents of the present invention will be described in detail below:

"Rubber modified styrene resin"

The rubber-modified styrenic resin of the present invention comprises 76% by weight to 86% by weight of the continuous phase formed by the copolymer component (A), and 14% by weight to 24% by weight of the rubber particle component (B). Disperse phase. Preferably, the rubber particle component (B) is contained in an amount ranging from 14% by weight to 20% by weight. When the content of the copolymer component (A) is less than 76% by weight, there is a disadvantage that the amount of discharge is lowered; when the content of the copolymer component (A) is more than 86% by weight, there is a disadvantage that the impact strength is insufficient.

The Z-average molecular weight (Mz×10 ^-4 ) of the rubber-modified styrene resin was measured by Gel Permeation Chromatography (GPC), and the load was 10 kg at a temperature of 220 ° C. The ratio of the melt flow index (MI) of the rubber modified styrene resin (Mz × 10 ^-4 /MI) was less than 18, and the Z average molecular weight of the rubber modified styrene resin was The ratio of the melt flow index (Mz × 10 ^-4 /MI) is not less than 18, which may result in poor discharge, insufficient impact strength, and poor thermal cycle. Preferably, the ratio of the Z average molecular weight to the melt flow index (Mz×10 ⁻⁴ /MI) of the rubber modified styrene resin is greater than 10 and less than 16, when the rubber is modified by the Z average of the styrene resin. When the ratio of the molecular weight to the melt flow index (Mz × 10 ^-4 /MI) is more than 10 and less than 16, the discharge amount, the impact strength, and the hot and cold cycle will reach a well-balanced preferred value.

The copolymer component (A) and the rubber particle component (B) in the rubber-modified styrene resin of the present invention are each further described below:

<Copolymer component (A)>

The copolymer component (A) is a styrene-acrylonitrile-based copolymer (A ₁ ). The styrene-acrylonitrile-based copolymer (A ₁ ) includes 50% by weight to 90% by weight of a styrene-based monomer unit, and 10% by weight to 50% by weight of an acrylonitrile-based monomer unit.

<Rubber particle component (B)>

The rubber particle component (B) includes rubber particles (B ₁ ) having a non-occluded structure, and rubber particles (B ₂ ) having a occluding structure.

Preferably, the rubber particle component (B) comprises from 25% by weight to 95% by weight, based on the total amount of the rubber particle component (B), of rubber particles (B ₁ ) having a non-occluded structure. And 5 to 75% by weight of rubber particles (B ₂ ) having a occluding structure. The rubber particles (B ₂ ) having a absorbing structure include one or several styrene-based copolymers and a first rubber body coated with a styrene-based copolymer. The rubber particles (B ₁ ) having a non-occluded structure include a second rubber body. The first rubber body and the second rubber body may be the same or different. The styrene-based copolymer is formed by a polymerization reaction comprising a mixture comprising a styrene monomer and an acrylonitrile monomer and optionally adding another copolymerizable vinyl monomer, the styrene monomer And the acrylonitrile-based monomer is used as in the block-like polymeric rubber graft copolymer (II) described below. The first rubber body or the second rubber body is respectively formed of a rubber component, and the rubber component is used as in the block polymer rubber graft copolymer (II) described below.

Preferably, the rubber particle component (B) comprises rubber particles having a weight average particle diameter of less than 0.4 μm, and rubber particles having a weight average particle diameter of 0.4 to 2 μm.

Preferably, the ratio of the total area of the rubber particles having a weight average particle diameter of less than 0.4 μm to the total area of the rubber particles having a weight average particle diameter of 0.4 to 2 μm is less than 3 throughout the composition. More preferably, the ratio of the total area of the rubber particles having a weight average particle diameter of less than 0.4 μm to the total area of the rubber particles having a weight average particle diameter of 0.4 to 2 μm is more than 1 and less than 3 throughout the composition. If the ratio of the total area of the rubber particles having a weight average particle diameter of less than 0.4 μm to the total area of the rubber particles having a weight average particle diameter of 0.4 to 2 μm is not less than 3, the disadvantage of poor thermal cycle is caused.

"Method for preparing rubber modified styrene resin"

A method of preparing the rubber-modified styrenic resin of the present invention comprises subjecting a kneaded composition comprising a copolymer mixture to a kneading treatment. Preferably, the method for preparing a rubber-modified styrene-based resin further comprises an extrusion granulation treatment after the kneading.

Wherein the mixture comprises 18% by weight to 25% by weight of the emulsion polymerized rubber graft copolymer (I), 5% by weight to 35% by weight of the bulk polymer rubber graft copolymer (II), and 40% by weight to 75% by weight The solution-polymerized ethylene-based copolymer (III) is % by weight.

Hereinafter, the emulsion-polymerized rubber graft copolymer (I), the bulk polymer rubber graft copolymer (II), and the solution-polymerized ethylene-based copolymer (III) will be described in detail one by one:

<Emulsified Polymer Rubber Graft Copolymer (I)>

The emulsion polymerized rubber graft copolymer (I) is obtained by graft polymerization of a rubber emulsion. The emulsion-polymerized rubber graft copolymer contains 45% by weight to 85% by weight of a rubber emulsion (solids), and 15% by weight to 55% by weight of the first monomer component.

In the graft polymerization, an additive may be optionally added, such as, but not limited to, a coagulant, an emulsifier, a polymerization initiator, or a chain transfer agent. After the graft polymerization reaction, steps such as coagulation, dehydration, and drying may be selectively performed.

The emulsion-polymerized rubber graft copolymer (I) contains a styrene-acrylonitrile-based copolymer (A ₁ ) and rubber particles (B ₁ ) having a non-occlusive structure. After the graft polymerization, the content of the styrene-acrylonitrile-based copolymer (A ₁ ) is in the range of 15% by weight to 55 based on 100% by weight based on the total amount of the emulsion-polymerized rubber graft copolymer (I). weight%.

[Rubber emulsion]

The rubber emulsion is obtained from 60% by weight to 100% by weight of the rubber component, and 0% by weight to 40% by weight of other copolymerizable monomers are obtained by emulsion polymerization, or further subjected to emulsion treatment after emulsion polymerization. .

The rubber emulsion is, for example but not limited to, polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, butadiene-methyl methacrylate copolymer, or isoprene-acrylic acid. Butyl ester copolymer and the like.

The rubber component is selected from a diene rubber, a polyacrylate rubber, or a polyoxyalkylene rubber. The diene rubber may be used singly or in combination, and the diene rubber is, for example but not limited to, butadiene rubber, isoprene. Rubber, chloroprene rubber, ethylene propylene diene terpolymer (EPDM), styrene-diene rubber, or acrylonitrile-diene rubber. Wherein the butadiene rubber is, for example but not limited to, a high cis (Hi-Cis) content butadiene rubber and a low cis (Low-Cis) content butadiene rubber, the high cis content butadiene The typical weight composition of cis (Cis)/vinyl (Vinyl) in rubber is (94 to 98 wt%) / (1 to 5 wt%), and the rest of the composition is trans (Trans) structure, and Mooney viscosity (mooney) Viscosity) between 20 and 120, the molecular weight range is preferably from 100,000 to 800,000; the typical weight composition of cis/vinyl in the low cis content butadiene rubber ranges from (20 to 40 wt%) / (1 to 20wt%), the rest is a trans structure, and the Mooney viscosity is between 20 and 120, and the molecular weight range is preferably from 100,000 to 800,000. The styrene-diene rubber is, for example but not limited to, styrene-butadiene rubber, styrene-isoprene rubber, etc., and the styrene-diene rubber may be a block copolymer or a random copolymer. (random) or star type, wherein the styrene-butadiene rubber has a weight ratio of styrene to butadiene ranging from 5:95 to 80:20, and the molecular weight range is preferably 50,000 to 600,000. Preferably, the styrene-diene rubber is a styrene-butadiene rubber.

The other copolymerizable monomer is, for example but not limited to, a styrene monomer, an acrylonitrile monomer, an acrylate monomer, or a methacrylate monomer.

The hypertrophy treatment can be carried out by a general method of freezing fat, mechanical fat or additive hypertrophy. The additive used in the additive hypertrophy method is, for example but not limited to, (1). Acidic substance: acetic anhydride, hydrogen chloride or sulfuric acid, etc.; (2). Salt-based substances: sodium chloride, potassium chloride or calcium chloride; (3). Polymeric condensate containing carboxylic acid group: (meth)acrylic acid-(meth) acrylate copolymer (such as methyl Acrylic acid-butyl acrylate copolymer, methacrylic acid-ethyl acrylate copolymer, and the like.

For example, the method for producing a diene rubber emulsion may be polymerized by an emulsion polymerization method using a diene monomer (for example, butadiene), or 50 to 100% by weight of a diene monomer and 0 weight. From 100% by weight to 50% by weight of a monomer such as styrene and/or acrylonitrile is polymerized by an emulsion polymerization method to obtain a diene rubber emulsion having a weight average particle diameter of from 0.05 μm to 0.8 μm. A small particle size diene rubber emulsion having a weight average particle diameter of 0.05 μm to 0.18 μm may be obtained by an emulsion polymerization method, and then subjected to a fertilizer treatment to increase the weight of the small particle size diene rubber emulsion. A large particle size diene rubber emulsion having an average particle diameter of 0.2 μm to 0.8 μm.

[First monomer component]

The first monomer component comprises 50% to 90% by weight of a styrenic monomer, 10% to 50% by weight of an acrylic monomer, and 0% to 40% by weight of another copolymerizable single body.

The styrene monomer may be used singly or in combination, such as but not limited to styrene, α-methylstyrene, p-t-butylstyrene, p-methylstyrene, ortho- Methylstyrene, m-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, α-methyl-p-methylstyrene, or bromostyrene. Preferably, the styrenic monomer is selected from the group consisting of styrene, alpha-methylstyrene, or a combination thereof.

The acrylonitrile monomer may be used singly or in combination, the acrylonitrile The monomer is, for example but not limited to, acrylonitrile or α-methacrylonitrile. Preferably, the acrylonitrile-based monomer is acrylonitrile.

The other copolymerizable vinyl monomer may be used singly or in combination, and the other copolymerizable vinyl monomer such as, but not limited to, an acrylic monomer, a methacrylic monomer, an acrylate monomer, or a A acrylate type monomer or the like. The acrylic monomer is, for example but not limited to, acrylic acid or the like. The methacrylic monomer is, for example but not limited to, methacrylic acid or the like. The acrylate monomer is, for example but not limited to, methyl acrylate, ethyl acrylate, isopropyl acrylate, or butyl acrylate. Preferably, the acrylate monomer is butyl acrylate. The methacrylate monomer is, for example but not limited to, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate, hexyl methacrylate, A Cyclohexyl acrylate, dodecyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate ), ethylene dimethacrylate, or neopentyl dimethacrylate, etc., preferably, the methacrylate monomer is selected from methyl methacrylate Or butyl methacrylate.

[additive]

The polymerization initiator is selected from a monofunctional polymerization initiator, a polyfunctional polymerization initiator, or a combination thereof. The monofunctional polymerization initiator may be used singly or in combination, and the monofunctional polymerization initiator is, for example but not limited to, benzoyl peroxide, dicumyl peroxide, Tributyl peroxide (t-butyl) Peroxide), t-butyl hydroperoxide, cumene hydroperoxide, t-butyl-peroxy benzoate, double- Bis-2-ethylhexyl peroxy dicarbonate, tert-butyl peroxy isopropyl carbonate (BPIC), cyclohexanone Peroxide), 2,2'-azo-bis-isobutyronitrile (AIBN), 1,1'-azobiscyclohexane-1-carbonitrile (1, 1'-azo-biscyclohexane-1-carbonitrile, or 2,2'-azo-bis-2-methyl butyronitrile. Among them, benzammonium peroxide and 2,2'-azo-bis-isobutyronitrile are preferred. The polyfunctional polymerization initiator may be used singly or in combination, and the polyfunctional polymerization initiator is, for example but not limited to, 1,1-bis-tert-butylperoxycyclohexane (1,1-bis-t) -butyl peroxy cyclohexane (TX-22), 1,1-bis-tert-butylperoxide-3,3,5-trimethylcyclohexane (1,1-bis-t-butylperoxy-3,3 ,5-trimethyl cyclohexane, abbreviated as TX-29A), 2,5-dimethyl-2,5-bis-(2-ethylperoxyhexane)hexane [2,5-dimethyl-2,5-bis -(2-ethylhexanoxy peroxy)hexane], 4-(t-butylperoxycarbonyl)-3-hexyl-6-[7-(t-butylperoxycarbonyl)heptyl]cyclohexane {4-( T-butyl peroxy carbonyl)-3-hexyl-6-[7-(t-butyl peroxy carbonyl)heptyl]cyclohexane}, di-t-butyl-diperoxyazelate 2,5-Dimethyl-2,5-bis(benzimidoxime)-hexane [2,5-dimethyl-2,5-bis-(benzoyl Peroxy)hexane], di-t-butyl peroxy-hexahydro-terephthalate (BPHTH), or 2,2-bis (4,4-di) -T-butyl-peroxide (2,2-bis-(4,4-di-t-butyl peroxy)cyclohexyl propane, abbreviated as PX-12].

The chain transfer agent may be used singly or in combination, and the chain transfer agent is, for example but not limited to, n-dodecyl mercaptan (NDM), stearyl mercaptan, third - t-dodecyl mercaptan (TDM), n-propyl mercaptan, n-octyl mercaptan, tri-octyl mercaptan, tri-decyl mercaptan, or antimony Terpinolene and the like.

The coagulant may be used singly or in combination, and the coagulant is, for example but not limited to, sulfuric acid, acetic acid, sodium sulfate, potassium sulfate, sodium hydrogen sulfite, potassium hydrogen sulfite, ammonium hydrogen sulfite, pyrosulfite, pyrosulfate. , hydrosulfite, formaldehydesulfoxylate, thiosulfate, sulfoxylate, calcium chloride, magnesium chloride, magnesium sulfate, or aluminum sulfate. Preferably, the coagulating agent is selected from the group consisting of sodium hydrogen sulfite, sodium metabisulfite, sodium dithionite, or sodium formaldehyde sulfoxylate.

The emulsifier may be used singly or in combination, and the emulsifier is, for example, but not limited to, potassium laurate, potassium stearate, potassium oleate, sodium dioctylsulfosuccinate or the like.

Preferably, the additive is used in an amount ranging from 0.01 part by weight to 5 parts by weight based on 100 parts by weight of the total of the rubber emulsion and the first monomer component. Part by weight; more preferably, the additive is used in an amount ranging from 0.1 part by weight to 3 parts by weight.

<Blocked Polymer Rubber Graft Copolymer (II)>

The bulk polymeric rubber graft copolymer (II) is obtained by bulk polymerization, and the bulk polymeric rubber graft copolymer comprises 100 parts by weight of the second monomer component, and 5 parts by weight to 30% by weight. Parts of the rubber component.

In the bulk polymerization reaction, an additive may be optionally added, and the additive is, for example but not limited to, a solvent, a polymerization initiator or a chain transfer agent, and the like.

The bulk polymer rubber graft copolymer (II) contains a styrene-acrylonitrile copolymer (A ₁ ) and rubber particles (B ₂ ) having a occluding structure.

[Rubber component]

The rubber component is the same as the rubber component used in the rubber emulsion prepared in the above-mentioned emulsion polymerization rubber graft copolymer (I), and therefore will not be described again.

[Second monomer component]

The second monomer component comprises 50% by weight to 90% by weight of the styrenic monomer, and 10% by weight to 50% by weight of the acrylic monomer, and optionally 0% by weight to 40% by weight. Other copolymerizable vinyl monomers. Preferably, the second monomer component comprises 58% by weight to 80% by weight of the styrene monomer, and 20% by weight to 42% by weight of the acrylonitrile monomer, and optionally 0% by weight~ 40% by weight of other copolymerizable vinyl monomers.

The type of the styrene monomer, the acrylonitrile monomer, and other copolymerizable vinyl monomers is as described above for the preparation of emulsion polymerization rubber grafting. The styrene monomer, the acrylonitrile monomer, and the other copolymerizable vinyl monomer used in the first monomer component in the copolymer (I) are the same, and therefore will not be described again.

[additive]

The polymerization initiator and the chain transfer agent in the additive selectively used in the bulk polymerization reaction are of the same kind as the polymerization initiator and the chain transfer agent used in the preparation of the emulsion polymerization rubber graft copolymer (I). Therefore, it will not be repeated.

The solvent may be used singly or in combination, and the solvent is, for example but not limited to, benzene, toluene, ethylbenzene, p-xylene, o-xylene, m-xylene, pentane, octane, cyclohexane, methyl ethyl ketone, acetone or methyl butyl Ketones, etc.

Preferably, the polymerization initiator is used in an amount ranging from 0.01 part by weight to 10 parts by weight based on 100 parts by total of the total of the rubber component and the second monomer component. Preferably, the chain transfer agent is used in an amount ranging from 0.001 part by weight to 1 part by weight based on 100 parts by total of the total of the rubber component and the second monomer component. Preferably, the solvent is used in an amount ranging from 10 parts by weight to 40 parts by weight based on 100 parts by weight of the total of the rubber component and the second monomer component.

The bulk polymer rubber graft copolymer (II) is prepared by continuously feeding the above-mentioned rubber component, styrene monomer, acrylonitrile monomer, and other copolymerizable vinyl monomer. After entering the reactor, after the reaction reaches the desired conversion rate, the solution formed by the reaction is continuously taken out from the reactor and introduced into a devolatilizer, and the unreacted starting material is removed by the devolatilizer And the volatile component produced after the reaction is removed, that is, the bulk polymeric rubber graft copolymer (II) of the present invention is obtained, or further fabricated grain.

The reactor is, for example but not limited to, a plug flow reactor (PFR), a continuous stirred-tank reactor (CSTR), or a reactor containing a static mixer (Static reactor) )Wait. The number of the reactors may be one, or two or more, preferably three or more, in combination. When more than two reactors are used, the first reactor is preferably a fully mixed reactor (CSTR). Preferably, the reactor is operated at a temperature in the range of from 80 ° C to 200 ° C; more preferably, the reactor is operated at a temperature in the range of from 90 ° C to 160 ° C. Preferably, the operating pressure of the reactor ranges from 1 kg/cm ² to 5 kg/cm ² .

The devolatilizer can use a vacuum degassing tank device or a degasser. The unreacted starting material removed by the devolatilizer or the volatile component generated after the reaction can be optionally recovered by a condenser, and the water in the recovered liquid can be removed and used as a starting material.

<Solvent Polymerized Vinyl Copolymer (III)>

The solution-polymerized ethylene-based copolymer (III) is obtained by solution polymerization, and the solution-polymerized ethylene-based copolymer (III) contains a third monomer component.

In the solution polymerization, an additive may be optionally added, such as, but not limited to, a coagulant, an emulsifier, a solvent, a polymerization initiator or a chain transfer agent, and the like. After the solution polymerization reaction, the steps of coagulation, dehydration, drying, and the like may be selectively performed.

The solution-polymerized ethylene-based copolymer (III) contains a styrene-acrylonitrile-based copolymer (A ₁ ).

[Third monomer component]

The third monomer component comprises from 60% by weight to 80% by weight of the styrenic monomer, and from 20% by weight to 40% by weight of the acrylic monomer, and optionally from 0% by weight to 40% by weight. Other copolymerizable vinyl monomers.

The type of the styrene monomer and the acrylonitrile monomer is the same as the styrene monomer and the acrylonitrile monomer used in the first monomer component in the preparation of the emulsion polymerized rubber graft copolymer (I). Therefore, it will not be repeated.

The other copolymerizable vinyl monomers in the third component may be used singly or in combination, such as, but not limited to, acrylic monomers, methacrylic monomers, acrylate monomers, methacrylate systems. a monomeric or monofunctional maleic imine monomer or the like, wherein the acrylic monomer, the methacrylic monomer, the acrylate monomer or the methacrylate monomer is an emulsion polymerization rubber prepared as described above The first monomer component in the graft copolymer (I) is the same and will not be described again.

[additive]

a coagulating agent, an emulsifier, a solvent, and a polymerization initiator which are additives which are selectively used in the solution polymerization reaction for preparing the solution-polymerized ethylene-based copolymer (III), and the above-mentioned preparation of the emulsion-polymerized rubber graft copolymer (I) and The coagulating agent, the emulsifier, the solvent, and the polymerization initiator used in the bulk polymeric rubber graft copolymer (II) are the same, and therefore will not be described again.

[chain transfer agent]

The chain transfer agent used in the preparation of the solution-polymerized ethylene-based copolymer may be a monofunctional chain transfer agent, a polyfunctional chain transfer agent or a mixture of both.

The monofunctional chain transfer agent can be used singly or in combination, for example but not limited to: (1). Mercaptan: methyl mercaptan, n-butyl mercaptan, cyclohexyl mercaptan, n--12 Alkyl mercaptan, stearyl mercaptan, t-dodecoyl mercaptan (TDM), n-propyl mercaptan, n-octyl mercaptan, third - octyl mercaptan, tri-decyl mercaptan, etc.; (2) alkyl amines: monoethylamine, diethylamine, triethylamine, monoisopropylamine, diiso Propylamine, monobutylamine, di-n-butylamine, tri-n-butylamine, etc.; (3.) Other: pentaphenylethane, α-methylstyrene dimer (α -methyl styrene dimer), terpinolene. Preferably, the monofunctional chain transfer agent is n-dodecyl mercaptan and tert-dodecyl mercaptan.

The polyfunctional chain transfer agent can be used singly or in combination, such as, but not limited to, pentaerythritol tetrakis (3-mercapto propionate), pentaerythritol tetrakis (2-) [pentaerythritol tetrakis (2-mercapto acetate)], tri-methyl 2-propcapto acetate, tri- (3-mercapto acetate), tris-(3-mercaptopropionic acid) Trimethylolpropane tris (3-mercapto propionate), TMPT], trimethylol-propane tris (6-mercapto hexanate), and the like. Preferably, the polyfunctional chain transfer agent is tris-(3-mercaptopropionic acid) trimethylolpropyl ester.

The chain transfer agent is used in an amount of from 0 to 2 parts by weight, preferably from 0.001 to 1 part by weight, based on 100 parts by total of the total of the solution-polymerized ethylene-based copolymer (III).

In the method for producing the solution-polymerized ethylene-based copolymer (III), the starting materials such as the styrene-based monomer, the acrylonitrile-based monomer, and other copolymerizable vinyl-based monomer are continuously fed into the reactor. After all the monomers in the starting material reach the desired conversion rate, the solution formed by the reaction is continuously taken out from the reactor and introduced into a devolatilizer, and the devolatilizer is unreacted. The starting material and the volatile component generated after the reaction are removed, that is, the solution-polymerized ethylene-based copolymer (III) is obtained, or further granulated. Among them, the final monomer conversion ratio is 50% by weight or more, preferably 60% by weight or more, and more preferably 70% by weight or more.

The reactor is, for example but not limited to, a columnar flow reactor, a fully mixed reactor, or a reactor containing a static mixer. The number of the reactors may be one, or two or more, preferably three or more, in combination. When more than two reactors are used, the first reactor is preferably a fully mixed reactor, and the final reactor is preferably a columnar flow reactor. Preferably, the reactor is operated at a temperature in the range of from 20 ° C to 300 ° C, more preferably from 60 ° C to 250 ° C, most preferably from 80 ° C to 240 ° C. Preferably, the operating pressure of the reactor ranges from 1 kg/cm ² to 10 kg/cm ² .

The devolatilizer can use a vacuum degassing tank device or a degasser. The unreacted starting material removed by the devolatilizer or the volatile component generated after the reaction can be optionally recovered by a condenser, and the water in the recovered liquid can be removed and used as a starting material.

The rubber modified styrene resin of the present invention can be prepared by a general mixing method, and the emulsion polymerized rubber graft copolymer (I), the block polymer rubber graft copolymer (II), and the solution polymerization ethylene copolymer ( III) Placement The rubber-modified styrene-based resin of the present invention is obtained by stirring in a stirrer until homogeneously mixing, and optionally adding an additive or other polymer. Wherein, the additive is, for example but not limited to, an antioxidant, a plasticizer, a processing aid, an ultraviolet stabilizer, a UV absorber, a filler, a strengthening agent, a coloring agent, a lubricant, a charging inhibitor, a flame retardant, and a flame retardant , heat stabilizers, coupling agents, etc. The additive may be respectively polymerized in the polymerization reaction of the above-mentioned emulsion polymerized rubber graft copolymer (I), bulk polymer rubber graft copolymer (II) or solution polymerized ethylene copolymer (III), after polymerization reaction, and before coagulation. Or the above-mentioned additive may be added during the process of preparing the rubber-modified styrene-based resin by performing the extrusion kneading treatment.

The antioxidant may be used singly or in combination, and the antioxidant is, for example but not limited to, a phenol-based antioxidant, a thioether-based antioxidant, or a phosphorus-based antioxidant. Preferably, the antioxidant is used in an amount of 2 parts by weight or less based on 100 parts by weight of the total of the rubber-modified styrene resin.

The phenolic antioxidant may be used singly or in combination, and the phenolic antioxidant is, for example but not limited to, octadecyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropionate [ 3,5-bis(1,1-dimethylethyl)-4-hydroxybenzenepropanoic acid octadecyl ester, model: antioxidant IX-1076], triethylene glycol bis[3-(3-tert-butyl-5-methyl- 4-hydroxyphenyl)propionate], tetrakis[methylene-3-(3,5-bis-tert-butyl-4-hydroxyphenyl)propionate]methane, 2-tert-butyl-6 -(3-t-butyl-2-hydroxy-6-methylbenzyl)-4-methylphenyl acrylate, 2,2'-methylene-bis(4-methyl-6- Tributylphenol) [2,2'-methylenebis(4-methyl-6-tert-butylphenol), model: Antioxidant 2246], 2,2'-thiobis(4-methyl-6-tert-butylphenol), 2,2'-thio-diethylene-bis[3-(3,5-double Tert-butyl-4-hydroxyphenyl)propionate], or 2,2'-ethylenediamine-bis[ethyl-3-(3,5-bis-tert-butyl-4-hydroxybenzene) Base) propionate] and the like.

The thioether-based antioxidant may be used singly or in combination, and the thioether-based antioxidant is, for example but not limited to, distearyl thiodipropionate, dipalmitoside dipropionate, pentaerythritol-tetra-(beta) - dodecamethyl-thiopropionate), or dioctadecyl sulfide, and the like.

The phosphorus-based antioxidant may be used singly or in combination, and the phosphorus-based antioxidant is selected from a phosphite-containing phosphorus-based antioxidant or a phosphate-containing phosphorus-based antioxidant or a combination thereof. The phosphite-containing phosphorus-based antioxidants such as, but not limited to, tris(nonylphenyl) phosphite, dodecyl phosphite, 4,4'-butylene bis(3-methyl-6- Tributylphenyl-bistridecylphosphite), tris(2,4-t-butylphenyl)phosphite, and the like. The phosphate-containing phosphorus-based antioxidant such as, but not limited to, tetrakis(2,4-t-butylphenyl)-4,4'-extended biphenyl phosphate, or 9,10-dihydro-9-oxygen -10-phosphate phenoxy-10-oxygen and the like.

The slip agent may be used singly or in combination, and the slip agent is, for example, but not limited to, metal soap such as calcium stearate, magnesium stearate, lithium stearate, or ethylene bis-stearamide (EBA). ), methylene distearylamine, palmitic acid decylamine, butyl stearate, palmitate stearate, pentaerythritol tetra-fatty acid ester, polypropionic acid tristearate, n-docosanoic acid, hard A compound such as a fatty acid, a polyethylene wax, a octadecanoic acid wax, a carnuba wax, a petroleum wax or the like. Preferably, the amount of the slip agent is in the range of 100 parts by weight based on 100 parts by weight of the total amount of the rubber-modified styrene resin. Parts by weight or less.

The other polymer is, for example but not limited to, polycarbonate, polyamine, polyethylene terephthalate, polybutylene terephthalate, polyphenylene ether, polyvinyl chloride, polymethyl methacrylate , ethylene-methyl methacrylate copolymer, polypropylene, styrene-butadiene block copolymer, hydrogenated acrylonitrile-butadiene copolymer, hydrogenated styrene-butadiene block copolymer, and the like. Preferably, the polymer is used in an amount ranging from 5 parts by weight to 200 parts by weight based on 100 parts by total of the total of the rubber-modified styrene resin.

The molded article of the rubber-modified styrene-based resin of the present invention is obtained by subjecting a rubber-modified styrene-based resin as described above to a processing and molding process. This processing and molding process can be carried out in a conventional manner and will not be described again.

The present invention will be further illustrated by the following examples, but it should be understood that this embodiment is intended to be illustrative only and not to be construed as limiting.

<Example>

[Synthesis Example 1] Emulsified Polymerized Rubber Graft Copolymer (I)

(1). 95.0 parts by weight of 1,3-butadiene, 5.0 parts by weight of acrylonitrile, 15.0 parts by weight of potassium persulfate solution, 3.0 parts by weight of sodium pyrophosphate, 1.5 parts by weight of potassium oleate, 140.0 parts by weight of distilled water, and 0.2 parts by weight of the third-dodecyl mercaptan was reacted at a reaction temperature of 65 ° C for 12 hours to obtain an oak A latex emulsion (having a conversion of 94%, a solid content of about 40%, and a weight average particle diameter of 0.1 μm).

(2). 85.0 parts by weight of ethyl acrylate, 15.0 parts by weight of acrylic acid, 0.3 parts by weight of thirteen-dodecyl mercaptan, 2.0 parts by weight of potassium oleate, 1.0 part by weight of sodium dioctylsulfosuccinate, 0.4 The carboxylic acid group-containing polymer aggregating agent is obtained by reacting parts by weight of cumene hydroperoxide, 0.3 parts by weight of sodium formaldehyde sulfoxylate, and 200.0 parts by weight of distilled water at a reaction temperature of 75 ° C for 5 hours. The rate is 95%, pH 6.0).

(3) using 3 parts by weight of the carboxylic acid group-containing polymer aggregating agent (dry weight) to make 100 parts by weight of the rubber latex (dry weight) liquid to obtain a fattening rubber emulsion (pH 8.5, weight average particle size) The diameter is 0.30 μm).

(4) Further 100.0 parts by weight of the hyperplasticized rubber emulsion (dry weight), 23.3 parts by weight of styrene, 10 parts by weight of acrylonitrile, 1.2 parts by weight of potassium oleate, 0.2 parts by weight of a third-dodecyl mercaptan 0.5 parts by weight of cumene hydroperoxide, 3.0 parts by weight of ferrous sulfate solution (concentration: 0.2% by weight), 3.0 parts by weight of sodium formaldehyde sulfoxylate solution (concentration: 10% by weight), and 20.0 parts by weight of ethylenediaminetetraacetic acid solution ( The concentration was 0.25 wt%), and 200.0 parts by weight of distilled water was mixed and reacted. Wherein, styrene and acrylonitrile are added to the reaction system for polymerization within 5 hours by continuous addition, followed by coagulation with calcium chloride (CaCl ₂ ), dehydration, and drying to a moisture content of 2% or less, thereby preparing Emulsified polymeric rubber graft copolymer (I).

(5) Dissolving the emulsion-polymerized rubber graft copolymer (I) with tetrahydrofuran and filtering to obtain a filtrate, and then adding methanol to the filtrate, so that the emulsion-polymerized rubber graft copolymer (I) has a non-occluded structure. The rubber particles (B ₁ ) were precipitated and filtered, and it was calculated that the emulsion polymerized graft copolymer (I) of the synthesis example 1 was composed of 25% by weight of a styrene-acrylonitrile copolymer, and 75% by weight of The rubber particles (B1) having a non-occluded structure were composed, and the rubber particles (B ₁ ) having a non-occlusive structure had a weight average particle diameter of 0.31 μm.

[Synthesis Example 2] Bulk polymeric rubber graft copolymer (II)

(1). 103.2 parts by weight of styrene, 15 parts by weight of styrene butadiene rubber (content of styrene is 25% by weight, content of butadiene is 75% by weight, Mw = 130,000), and 45.4 parts by weight of ethylbenzene 31.4 parts by weight of acrylonitrile, 3.9 parts by weight of butyl acrylate, 0.08 parts by weight of n-dodecyl mercaptan, 0.063 parts by weight of 3,5-bis(1,1-dimethylethyl)-4-hydroxybenzene The octadecyl propyl propionate and 0.063 parts by weight of ethylene disteamine are mixed to obtain a mixture.

(2). 100 parts by weight of styrene, 3.0 parts by weight of 1,1-bis-tert-butylperoxycyclohexane, and 1.8 parts by weight of dibenzoyl peroxide were mixed to form a polymerization initiator solution.

(3) using a pump at a flow rate of 61 kg / hour, and the polymerization initiator solution was continuously supplied to the first reactor at a flow rate of 1.3 kg / hour to carry out a reaction, and the obtained polymerization was completed. The solution then enters the second reactor, the third reactor and the fourth reactor in sequence to carry out the reaction. The first, second, third, and fourth reactors described above are connected in series, and the reactors are all columnar flow reactors having a capacity of 100 liters. The first reactor reaction temperature is 75 ° C to 90 ° C, stirring at a rotation speed of 110 rpm; the second reactor reaction temperature is 95 ° C to 105 ° C, stirring at a rotation speed of 80 rpm; The reactor reaction temperature was 110 ° C to 125 ° C, and the mixture was stirred at a rotation speed of 60 rpm; the fourth reactor reaction temperature was 135 ° C to 150 ° C, and stirred at a rotation speed of 5 rpm; finally, the polymer solid content was 62.5%. After the reaction is completed, the unreacted monomer and solvent are removed by devolatilization equipment for recycling, and then the strip is extruded through a die, and then cooled and pelletized to obtain a bulk polymer rubber graft copolymer (II). .

(4) mixing acetone with the bulk polymeric rubber graft copolymer (II), so that the rubber particles (B ₂ ) having a occluding structure in the bulk polymeric rubber graft copolymer (II) are precipitated and filtered, that is, It is calculated that the bulk polymeric rubber graft copolymer (II) is composed of 88.2% by weight of a styrene-acrylonitrile-based copolymer and 11.8% by weight of rubber particles (B ₂ ) having a occluding structure.

[Synthesis Example 3] Solution polymerization ethylene copolymer (III)

(1). One comprises 65.5 parts by weight of styrene, 34.5 parts by weight of acrylonitrile, and 0.022 parts by weight of N,N'-4,4'-diphenylmethane bismaleimide, 0.01 parts by weight of 1, 1-bis-tert-butylperoxy-3,3,5-trimethylcyclohexane (starter), 0.4 parts by weight of dodecyl mercaptan (chain transfer agent), and 25 parts by weight of B a first mixed solution of benzene is continuously supplied to a first reactor at a flow rate of 37 kg/hour for polymerization; a polymer solution obtained in the first reactor is introduced into the second reactor, and one comprises 100 parts by weight Styrene, and 0.15 parts by weight of a second mixed solution of N,N'-4,4'-diphenylmethane bismaleimide, continuously supplied to a second reactor at a flow rate of 3 kg / hour The polymerization reaction is carried out; the polymer solution obtained in the second reactor is further introduced into a third reactor for polymerization. The first, second, and third reactors are sequentially connected in series, and the first and second reactors are CSTRs, The three reactors are PFR, and the volumes of the first, second, and third reactors are 40 liters, 40 liters, and 75 liters, respectively, and the reaction tank temperatures are 95 ° C, 105 ° C, and 135 ° C, respectively, and the stirring rates are 120 rpm and 90 rpm, respectively. At 35 rpm, the monomer conversion at the third reactor outlet was 74% by weight.

(2) After the completion of the polymerization, the copolymer solution obtained by the third reactor reaction is subjected to a step of devolatilization, extrusion, granulation, and the like to obtain a solution-polymerized ethylene-based copolymer (III).

[Synthesis Example 4] Solution polymerization ethylene copolymer (IV)

(1). 76% by weight of styrene and 24% by weight of acrylonitrile were placed at a rate of 12 kg/hour at a temperature of 108 ° C and a capacity of 45 liters of a continuous tank reactor equipped with a stirrer Mixing and reacting, and adding ethylene distearylamine, benzoyl peroxide and tert-dodecyl mercaptan to the continuous kettle type reactor at a rate of 3.0 g/hour. a solution, maintaining the proportion of toluene in the reaction solution at 15%, and maintaining the polymerization rate at 55%, and removing the volatile component by a devolatilization device to obtain a solution polymerization ethylene copolymer (IV) Particles (melt flow index is 3.0).

(2) While obtaining the particles of the solution-polymerized ethylene-based copolymer (IV), the removed volatile components may be condensed by a condenser as a recovery liquid, and continuously added to a continuous reactor type reactor for further use. .

[Examples 1 to 7 and Comparative Examples 1 to 4] Rubber-modified styrene-based resin and molded article thereof

(1). Examples 1 to 7 are the emulsion-polymerized rubber graft copolymers (I) of Synthesis Example 1 according to the amounts of the components listed in Table 1, Synthesis Example 2 The bulk polymeric rubber graft copolymer (II) and the solution polymerized ethylene copolymer (III) are mixed to form a resin mixture, and 0.7 parts by weight of ethylene double ten is added based on 100 parts by weight of the total of the resin mixture. Octaamine, and 0.5 parts by weight of octadecyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropionate [3,5-bis(1,1-dimethylethyl) -4-hydroxybenzenepropanoic acid octadecyl ester, model: IX-1076], forming a copolymer mixture. Further, the copolymer mixture was mixed and granulated at 235 ° C by an extruder (manufacturer model: Werner & Pfleidrer ZSK 35) to obtain a rubber-modified styrene-based resin of the present invention. (2). Next, after the rubber-modified styrene-based resin is injected into the test piece at 230 ° C by an injection molding machine (manufacturer model: Zhenxiong SM-90), the rubber-modified styrene-based resin of the present invention is obtained. The results of the analysis and physical property evaluation are shown in Table 2.

[Quality test]

1. Melt flow index (MI): The rubber-modified styrene-based resins of Examples 1 to 7 and Comparative Examples 1 to 4 were tested at 220 ° C × 10 kg in accordance with JIS K-7210, in units of: g/10min.

2. Z-average molecular weight (Mz × 10 ^-4 ): The rubber-modified styrene resins of Examples 1 to 7 and Comparative Examples 1 to 4 were measured by a conventional colloidal permeation chromatography.

3. Weight average particle diameter: The rubber-modified styrene-based resins of Examples 1 to 7 and Comparative Examples 1 to 4 were respectively dyed with osmium tetroxide (OsO ₄ ), and then photographed by a transmission electron microscope at 10,000 magnification. The rubber particles (200 to 1,000 in number) photographed in the photograph were individually measured for their particle diameter (D, unit μm), and the average particle diameter (Davg) was determined according to the following formula:

In the formula, N _i is the number of rubber particles having a particle diameter D _i ; D _i is the particle diameter of the i-th rubber particle.

4. The total area of rubber particles

The rubber-modified styrene resins of Examples 1 to 7 and Comparative Examples 1 to 4 were observed with a transmission electron microscope at a magnification of 1 million times, and the total area of the rubber particles was calculated by using image pro plus software.

5. Continuous phase Q value

Continuous phase Q value = weight average molecular weight ÷ number average molecular weight

6. Impact strength (Izod): The rubber-modified styrene resins of Examples 1 to 7 and Comparative Examples 1 to 4 were injected, and according to the standard method of ASTM D-256 (23 ° C, 1/notched) 4 吋 thick test piece) Prepare standard test pieces and test the standard test pieces according to the provisions of ASTM D-256, unit: kg-cm/cm.

7. Low-temperature drop-ball impact: The rubber-modified styrene-based resins of Examples 1 to 7 and Comparative Examples 1 to 4 were respectively prepared to have a test of 107 mm × 107 mm × 1/8". sheet. The low temperature falling ball impact strength needs to be placed in the -20 ° C freezer for 24 hours before measuring the instrument Dynatup 8250, according to ASTM-3763, the weight drop weight is 23.64 kg, the drop weight is 0.56 m. The impact velocity was 3.34 m/sec and the energy required to break the test pieces was measured in units of J.

8. Thermal cycle: The rubber-modified styrene resins of Examples 1 to 7 and Comparative Examples 1 to 4 were respectively prepared into test pieces having a size of 230 mm × 30 mm × 2 mm, and after the test pieces were stretched by 10%, It is mounted on a bending fixture and placed in a closed device containing cyclopentane gas for thermal cycle test (cold heat cycle condition is first stage: -30 ° C, 12 hours; second stage: 60 ° C, 12 hours) Repeat three cycles) and observe the appearance of the test pieces for cracks. No crack is marked as "○", and cracks are marked as "X".

9. Discharge amount: The discharge amount of the rubber-modified styrene-based resin of Examples 1 to 7 and Comparative Examples 1 to 4 was evaluated by a uniaxial extruder (manufacturer model: continental mechine MH540), and the extrusion temperature was 230 ° C, and the rotation speed was 40 rpm. Weighed after 5 minutes. Unit: g/min.

As shown in Tables 1 and 2, it was confirmed that Examples 1 to 7 were mixed using the above-mentioned emulsion polymerization rubber graft copolymer (I), bulk polymer rubber graft copolymer (II), and solution polymerization ethylene resin (III). The rubber modified styrene resin obtained by refining, the content of the control copolymer component (A) is in the range of 76% by weight to 86% by weight, and the content of the rubber particle component (B) is in the range of 14% by weight to 24% by weight. And the rubber modified styrene resin has a ratio of the Z average molecular weight to the melt flow index of less than 18, so that the rubber modified styrene resin has a discharge amount of 57 to 62, thereby demonstrating the rubber modification. The styrene resin has excellent processing properties, and the molded article obtained from the rubber modified styrene resin has an impact strength of 31.1 to 42.8, which proves that the molded article obtained by the rubber modified styrene resin has Excellent mechanical properties, low-temperature falling ball impact strength of 8.1 to 10.8 and good performance in hot and cold cycle test, representing the molded product of the rubber modified styrene resin in low temperature and thermal expansion and contraction environment It still maintains good properties.

Comparative Examples 1 and 2 were prepared by using an emulsion-polymerized rubber graft copolymer (I), a bulk polymerized rubber graft copolymer (II), and a solution-polymerized ethylene-based copolymer (IV), and The ratio of the Z average molecular weight to the melt flow index of the rubber modified styrene resin is 20.29 and 19.68, respectively, resulting in a discharge volume of only 50 and 48, respectively. The molded article obtained has low temperature falling ball impact strength, impact strength and thermal cycle. The performance is also much lower than in Examples 1 to 7.

In Comparative Example 3, since the content of the copolymer component (A) was 86.85% by weight and the content of the rubber particle component (B) was 13.15% by weight, the impact strength of the obtained molded article was 20, and the low-temperature falling ball impact was obtained. The intensity is 5.5, And did not pass the thermal cycle test.

In Comparative Example 4, since the ratio of the Z average molecular weight to the melt flow index of the rubber-modified styrene resin was 25.40, the amount of the rubber-modified styrene resin discharged was only 40, and the obtained molded article did not pass through the heat and cold. Loop test.

In summary, the rubber modified styrene resin of the present invention is prepared by using an emulsion polymerized rubber graft copolymer (I), a bulk polymer rubber graft copolymer (II), and a solution polymerized ethylene copolymer (III). The preparation method of the kneading treatment is carried out, and the content of the copolymer component (A) and the rubber particle component (B) of the rubber-modified styrene resin is controlled, and the Z average of the rubber-modified styrene resin is matched. The ratio of the molecular weight to the melt flow index is less than 18, so that the rubber modified styrene resin has good processing properties, and the obtained molded article has excellent mechanical properties and can be in the case of low temperature and thermal expansion and contraction. The performance of the present invention can be achieved by maintaining good performance.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.

Claims (10)

A rubber-modified styrene-based resin comprising 76% by weight to 86% by weight of a continuous phase formed by the copolymer component (A); and 14% by weight to 24% by weight of a rubber particle component (B) a dispersed phase; wherein the copolymer component (A) is a styrene-acrylonitrile-based copolymer (A ₁ ); the rubber particle component (B) comprises rubber particles (B ₁ ) having a non-occluded structure, and a rubber particle (B ₂ ) having a occlusion structure; and a Z average molecular weight Mz × 10 ^{-4 of} the rubber modified styrene resin measured by colloidal permeation chromatography, and a load of 10 kg at a temperature of 220 ° C The ratio Mz × 10 ^-4 /MI of the melt flow index MI of the rubber-modified styrene-based resin is less than 18. The rubber-modified styrene-based resin according to claim 1, wherein the Mz × 10 ^-4 /MI is more than 10 and less than 16. The rubber-modified styrene-based resin according to claim 2, wherein the rubber particle component (B) is contained in an amount ranging from 14 to 20% by weight. The rubber-modified styrene-based resin according to claim 1, wherein the rubber particle component (B) comprises rubber particles having a weight average particle diameter of less than 0.4 μm, and rubber particles having a weight average particle diameter of 0.4 to 2 μm. The rubber-modified styrene-based resin according to claim 4, wherein the total area of the rubber particles having a weight average particle diameter of less than 0.4 μm and the rubber particles having a weight average particle diameter of 0.4 to 2 μm are used throughout the composition. The ratio of the total area is less than 3. The rubber-modified styrene-based resin according to claim 5, wherein the total area of the rubber particles having a weight average particle diameter of less than 0.4 μm and the rubber particles having a weight average particle diameter of 0.4 to 2 μm are used throughout the composition. The ratio of the total area is greater than 1 and less than 3. A molded article obtained by subjecting a rubber-modified styrene-based resin according to any one of claims 1 to 6 to a molding process. A method for producing a rubber-modified styrene-based resin according to any one of claims 1 to 6, which comprises comprising 18% by weight to 25% by weight of an emulsion polymerized rubber graft copolymer (I), 5 to 35% by weight of the bulk polymer rubber graft copolymer (II), and 40 to 75% by weight of the copolymer mixture of the solution polymerized ethylene copolymer (III) are kneaded. The method according to claim 8, wherein the solution-polymerized ethylene-based copolymer (III) comprises a styrene-based monomer comprising 60% by weight to 80% by weight, and 20% by weight to 40% by weight. The monomer component of the acrylonitrile-based monomer is obtained by polymerization. The method of claim 8, further comprising an extrusion granulation treatment after the mixing.