KR20170134298A - Thermoplastic resin composition and molding product made therefrom - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition and a molded product formed therefrom. The purpose of the present invention is to provide a thermoplastic resin composition which has both sheet extrusion properties and vacuum formability by increasing elongational viscosity and lowering shear viscosity at the same time, and a molded product formed from the thermoplastic resin composition. The thermoplastic resin composition comprises a branched copolymer and a rubber-modified styrene based resin, wherein the branched copolymer includes a tetrathiol compound unit, a styrene-based monomer unit, and an acrylonitrile-based monomer unit. The rubber-modified styrene based resin includes a continuous phase formed of 70 to 90 wt% of a styrene-based copolymer and a dispersed phase formed of 10 to 30 wt% of rubber particles, and the styrene-based copolymer comprises first and second styrene-acrylonitrile based copolymers with different weight average molecular weights. Based on the total content 100 wt% of the first and second styrene-acrylonitrile based copolymers, the first styrene-acrylonitrile based copolymer has a content of 45 to 55 wt%, and the second styrene-acrylonitrile based copolymer has a content of 45 to 55 wt%.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a thermoplastic resin composition,

The present invention relates to a resin composition, and more particularly to a thermoplastic resin composition and a molded article formed therefrom.

BACKGROUND ART Thermoplastic resins such as styrene resins have been widely applied to a wide range of fields such as home electronic devices, machine parts, office supplies, electronic devices, and automobile industries. Among them, a molded article made of a styrenic resin has uniform surface gloss and is very beautiful in appearance, so that it is usually used as a casing of a product.

A common thermoplastic resin processing molding method, such as injection molding, extrusion molding, or stretch blow molding, can mold a thermoplastic resin. In addition, there is a special processing method of the same type as that of vacuum molding, which is a method of extruding a resin into a sheet, heating it to soften it, and producing a necessary molded article by using a vacuum pressure. Among them, the degree of difficulty of sheet extrusion relates to the shear viscosity of the resin itself, and generally, it is advantageous for sheet extrusion molding if the shear viscosity is low. In addition, since the vacuum formability is related to the elongational viscosity of the resin itself, a high elongation viscosity means that the resin can be easily stretched and deformed during processing, and the moldability is improved.

It has been known in the prior art that addition of a small amount of a linear copolymer or a branched copolymer improves the shear viscosity and elongational viscosity of a thermoplastic resin. However, if the added amount is too high, The shear viscosity of the resin can not be lowered, and therefore the sheet extrusion characteristics can be influenced. Therefore, it is a problem to be solved that a high elongation viscosity and a low shear viscosity ratio are combined with the thermoplastic resin.

The present invention is intended to provide a thermoplastic resin composition which increases the extensional viscosity and decreases the shear viscosity ratio so that the extrusion of the sheet and the vacuum formability are combined, and a molded article formed from the composition.

The thermoplastic resin composition of the present invention includes a branched copolymer and a rubber-modified styrene resin. Wherein the branched copolymer comprises a tetrathiol compound unit, a first styrene monomer unit and a first acrylonitrile monomer unit, wherein the rubber-modified styrene resin is a styrene-based copolymer containing 70% by weight to 90% by weight A continuous phase formed and a dispersed phase formed from 10% by weight to 30% by weight of rubber particles, wherein the styrenic copolymer comprises a first styrene-acrylonitrile-based copolymer and a second styrene-acrylonitrile- And the weight-average molecular weight of the first styrene-acrylonitrile-based copolymer is different from the weight-average molecular weight of the second styrene-acrylonitrile-based copolymer. The content of the first styrene-acrylonitrile-based copolymer is from 45% by weight to 55% by weight based on 100% by weight of the total content of the first styrene-acrylonitrile-based copolymer and the second styrene-acrylonitrile- %, And the content of the second styrene-acrylonitrile-based copolymer is 45 wt% to 55 wt%.

In one embodiment of the present invention, the weight average molecular weight of the first styrene-acrylonitrile-based copolymer is, for example, 180,000 to 240,000, and the weight average molecular weight of the second styrene- For example, between 110,000 and 170,000.

In one embodiment of the present invention, the first styrene-acrylonitrile-based copolymer comprises 71 wt% to 74 wt% of a second styrene-based monomer unit and 26 wt% to 29 wt% of a second acrylonitrile-based monomer Unit, and the second styrene-acrylonitrile-based copolymer comprises 60 wt% to 69 wt% of a third styrene-based monomer unit and 31 wt% to 40 wt% of a third acrylonitrile-based monomer unit .

In one embodiment of the present invention, the content of the branched copolymer is from 1 part by weight to 10 parts by weight based on 100 parts by weight of the rubber-modified styrene series.

In one embodiment of the present invention, the content of the branched copolymer is from 1.5 to 8 parts by weight based on 100 parts by weight of the rubber-modified styrene resin.

In one embodiment of the present invention, the content of the branched copolymer is from 2.5 to 6 parts by weight based on 100 parts by weight of the rubber-modified styrene resin.

In one embodiment of the present invention, the average radius of gyration of the branched copolymer is from 75 nanometers to 110 nanometers.

In one embodiment of the present invention, the average radius of gyration of the branched copolymer is 80 nanometers to 100 nanometers.

In one embodiment of the present invention, the weight average molecular weight of the branched copolymer is from 1 million to 7 million.

In one embodiment of the present invention, the weight average molecular weight of the branched copolymer is 2,000,000 to 5,000,000.

In one embodiment of the present invention, the tetrathiol compound unit is formed of a tetrathiol compound.

In one embodiment of the present invention, the tetrathiol compound is selected from the group consisting of pentaerythritol tetrakis (3-mercapto propionate), pentaerythritol tetrakis (2-mercaptoethanate ), pentaerythritol tetrakis (2-mercapto ethanate), pentaerythritol tetrakis (4-mercapto butanate), pentaerythritol tetrakis (5-mercapto pentanate) pentaerythritol tetrakis (5-mercapto pentanate)], and pentaerythritol tetrakis (6-mercapto hexanate).

In one embodiment of the present invention, the tetrathiol compound is, for example, pentaerythritol tetrakis (3-mercapto propionate).

The molded article of the present invention is formed of the thermoplastic resin composition as described above.

According to the above description, the thermoplastic resin composition of the present invention comprises a branched copolymer and a rubber-modified styrene resin, and the styrene-based copolymer in the rubber-modified styrene resin has first and second styrene- Acrylonitrile-based copolymer, wherein the content of the first styrene-acrylonitrile-based copolymer is 45 wt% based on 100 wt% of the total content of the first and second styrene-acrylonitrile- To 55% by weight, and the content of the second styrene-acrylonitrile copolymer is 45% by weight to 55% by weight. The molded article thus produced can have an improved elongational viscosity and a lowered shear viscosity, It is suitable not only for extrusion but also for special processing methods such as vacuum forming.

In order to make the features and advantages of the present invention clearer and easier to understand, embodiments will be described in detail.

Hereinafter, embodiments of the present invention will be described in detail, but these embodiments are illustrative, and the disclosure of the present invention is not limited thereto.

In one embodiment of the present invention, the thermoplastic resin composition comprises a branched copolymer and a rubber-modified styrene resin. Wherein the branched copolymer comprises a tetrathiol compound unit, a first styrene monomer unit and a first acrylonitrile monomer unit; The rubber-modified styrenic resin includes a continuous phase styrenic copolymer and a dispersed phase rubber particle, wherein the styrenic copolymer further contains a first styrene-acrylonitrile copolymer and a second styrene-acrylonitrile copolymer having different weight average molecular weights Nitrile-based copolymer. Based on 100% of the total content of the first styrene-acrylonitrile-based copolymer and the second styrene-acrylonitrile-based copolymer, the content of the first styrene-acrylonitrile-based copolymer is 45% by weight to 55% And the content of the second styrene-acrylonitrile-based copolymer is 45% by weight to 55% by weight.

On the other hand, in the thermoplastic resin composition of the present embodiment, the content of the branched copolymer is, for example, 1 part by weight to 10 parts by weight based on 100 parts by weight of the rubber-modified styrene resin. , The elongation viscosity and the shear viscosity rate are increased. The content of the branched copolymer is preferably about 1.5 parts by weight to 8 parts by weight, and the content of the branched copolymer is more preferably about 2.5 parts by weight to 6 parts by weight.

Hereinafter, the present embodiment will be described, but the present invention is not limited thereto.

Origin of Branched Copolymer

The tetrathiol compound unit contained in the branched copolymer of this embodiment may be formed of a tetrathiol compound. For example, the tetrathiol compound is formed after removing hydrogen from the thiol group from the tetrathiol compound, and the tetrathiol compound is, for example, pentaerythritol tetrakis (3-mercapto propionate) Pentaerythritol tetrakis (2-mercapto ethanate)], pentaerythritol tetrakis (4-mercapto butanate)], pentaerythritol tetrakis (2-mercaptoethanate) A group consisting of pentaerythritol tetrakis (5-mercapto pentanate), and pentaerythritol tetrakis (6-mercapto hexanate) ≪ / RTI > Among them, pentaerythritol tetrakis (3-mercaptopropionate) is preferable.

Also, the first styrene-based monomer unit contained in the branched copolymer is, for example, a styrene monomer unit; The first acrylonitrile-based monomer unit is, for example, an acrylonitrile monomer unit. Herein, the so-called monomer unit refers to a structural unit in which a first styrene-based monomer or a first acrylonitrile-based monomer is subjected to a copolymerization reaction.

The first styrene-based monomer may be used alone or in combination. The first styrene-based monomer may be selected from styrene,? -Methylstyrene, pt-butylstyrene, p-methylstyrene, But are not limited to, 4-dimethylstyrene, ethylstyrene,? -Methyl-p-methylstyrene or bromostyrene, and the first styrene-based monomer is styrene,? -Methylstyrene, or a combination thereof desirable.

The first acrylonitrile-based monomer may be used alone or in combination, and the first acrylonitrile-based monomer may include, but is not limited to, acrylonitrile or? -Methylacrylonitrile, The nitrile-based monomer is preferably acrylonitrile.

The branched copolymer of this embodiment can be produced by a conventional method known in the art to which the present invention belongs, for example, by emulsion polymerization, bulk polymerization, suspension polymerization and solution polymerization, The average radius of turn of the coalescence is, for example, between 75 nanometers and 110 nanometers, more preferably between 80 nanometers and 100 nanometers. The weight average molecular weight is, for example, between 1 million and 7,000,000, and more preferably between 2,000,000 and 5,000,000.

Origin of rubber-modified styrene resin

Among the rubber-modified styrene type resins of this embodiment, the weight average molecular weight of the first styrene-acrylonitrile-based copolymer in the styrenic copolymer for forming a continuous phase is between 180,000 and 240,000, for example, -Acrylonitrile-based copolymer has a weight average molecular weight of, for example, between 110,000 and 170,000. The rubber particles forming the dispersed phase include, for example, graft copolymers grafted to rubber polymers and rubber polymers, for example, rubber graft copolymers. The rubber-modified styrene-based resin in the present embodiment can be used, for example, by a graft-kneading method in which the styrene-based copolymer and a rubber component (for example, a rubber graft copolymer) are kneaded in a dry state using a twin-screw extruder.

≪ First styrene-acrylonitrile copolymer >

In this embodiment, the first styrene-acrylonitrile-based copolymer comprises, for example, 71 to 74 wt% of a second styrene-based monomer unit and 26 to 29 wt% of a second acrylonitrile-based monomer Unit. Herein, the so-called monomer unit refers to a structural unit in which a second styrene-based monomer or a second acrylonitrile-based monomer is subjected to a copolymerization reaction.

Specifically, in the first embodiment, the first styrene-acrylonitrile-based copolymer is not particularly limited in the method of producing the copolymer and can be selected from commonly used solution polymerization methods, bulk polymerization methods, emulsion polymerization methods, suspension- And the like can be used, and it is preferable to use a solution polymerization method or a bulk polymerization method. The reactors used in the above reactions may be one or a combination of different types of complete mixed continuous type reactors (CSTR), plug flow reactors (PFR), or static mixing reactors. For example, in the solution-polymerization method, the first styrene-acrylonitrile-based copolymer production method comprises preparing a monomer component comprising a second styrene-based monomer and a second acrylonitrile-based monomer by solution copolymerization. However, the present invention is not limited thereto. In another embodiment, a method for preparing a first styrene-acrylonitrile-based copolymer comprises reacting a monomer component of a second styrene-based monomer, a second acrylonitrile-based monomer, and a first other copolymerizable monomer through a solution copolymerization reaction Or may be manufactured.

The second styrenic monomer may be selected from the group consisting of styrene,? -Methylstyrene, pt-butylstyrene, p-methylstyrene, o-methylstyrene, m- But are not limited to, 4-dimethylstyrene, ethylstyrene,? -Methyl-p-methylstyrene or bromostyrene, and the second styrene-based monomer is preferably styrene,? -Methylstyrene or a combination thereof Do. Further, the content range of the second styrene-based monomer is, for example, 50% by weight to 90% by weight based on 100% of the total amount of the second styrene-based monomer, the second acrylonitrile-based monomer and the first other copolymerizable monomer ; Preferably from 55% to 85% by weight; And more preferably from 58% by weight to 80% by weight.

The second acrylonitrile-based monomer may be used alone or in combination, and the second acrylonitrile-based monomer may include, but is not limited to, acrylonitrile or -methyl acrylonitrile, and the second acrylonitrile- The monomer is preferably acrylonitrile. Further, the content range of the second acrylonitrile-based monomer may be, for example, from 10% by weight to 50% by weight, based on the total amount of the second styrene-based monomer, the second acrylonitrile-based monomer and the first other copolymerizable monomer %ego; Preferably from 15% to 45% by weight; More preferably 20% by weight to 42% by weight.

The first other copolymerizable monomer may be used singly or in combination, and the first other copolymerizable monomer may be an acrylic acid monomer, a methacrylic acid monomer, an acrylate monomer, a methacrylate monomer, a monofunctional maleimide monomer, There can be mentioned ethylene, propylene, 1-butylene, 1-pentene, 4-methyl-1-pentene, ethylene chloride, vinylidene chloride, tetrafluoroethylene, vinylidene chloride, trifluoroethylene chloride, hexafluoro But are not limited to, propylene, butadiene, propenylamine, isobutenylamine, vinyl acetate, ethyl vinyl ether, methyl vinyl ketone, maleic acid, But are not limited to, cis-methylbutenedioic acid, trans-methylbutenedioic acid, and the like. In particular, acrylic acid monomers include, but are not limited to, acrylic acid. The methacrylic acid monomer includes, but is not limited to, methacrylic acid, and the acrylate-based monomer includes but is not limited to methacrylate, ethyl acrylate, or butyl acrylate, and the acrylate- . Examples of the methacrylate monomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, phenyl methyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, 2 (Meth) acrylates such as methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, epoxypropyl methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, ethylene dimethacrylate, or neopentyl dimethacrylate neopentyl dimethacrylate). The monofunctional maleimide-based monomer means that only a single maleimide functional group is contained in the monomer. The monofunctional maleimide-based monomer may be used singly or in combination, and the monofunctional maleimide-based monomer may be, for example, maleimide, N-methylmaleimide, N-butylmaleimide, N-hexylmaleimide , N-dodecylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide (abbreviated as PMI), N-2-methylmaleimide, N-2,3-dimethyl Maleic anhydride, maleimide, N-2,4-dimethyl maleimide, N-2,6-dimethyl maleimide, N-2,3-diethyl maleimide, N- -Dibutylmaleimide, N-2,4-dibutylmaleimide, N-2,3-dichlorophenylmaleimide, N-2,4-dichlorophenylmaleimide, N-2,3-dibromophenylmaleimide Amide or N-2,4-dibromophenylmaleimide, and the like. The monofunctional maleimide-based monomer is preferably, for example, N-phenylmaleimide. Also, the first other copolymerizable monomer is preferably selected from methyl methacrylate, butyl methacrylate, monofunctional maleimide-based monomer, or a combination as described above. Also, the content of the first other copolymerizable monomer may be, for example, from 0% by weight to 40% by weight, based on the total amount of 100% by weight of the second styrene-based monomer, the second acrylonitrile-based monomer and the first other copolymerizable monomer %ego; 0% by weight to 30% by weight; And more preferably 0 wt% to 22 wt%.

The solvent used in the solution copolymerization reaction is, for example, benzene, toluene, ethylbenzene, p-xylene, o-xylene, m-xylene, pentane, octane, cyclohexane, methyl ethyl ketone, acetone or methyl butyl ketone. The amount of the solvent used is, for example, 0 to 40 parts by weight, preferably 5 to 35 parts by weight, based on 100 parts by weight of the reactant.

In the solution copolymerization reaction, the polymerization initiator may be selectively added. The amount of the polymerization initiator to be used is, for example, 0 to 1 part by weight, preferably 0.001 to 0.5 part by weight, based on 100 parts by weight of the reactant.

More specifically, the polymerization initiator may include a single functional polymerization initiator, a multifunctional polymerization initiator, or a combination thereof. The monofunctional polymerization initiator may be used singly or in combination, and the monofunctional polymerization initiator may be benzoyl peroxide, dicumyl peroxide, t-butyl peroxide, cumene hydrogen peroxide cumene hydroperoxide, t-butyl-peroxy benzoate, bis-2-ethylhexyl peroxy dicarbonate, t-butyl peroxyisopropyl carbonate tert-butyl peroxy isopropyl carbonate (BPIC), cycolhexanone peroxide, 2,2'-azo-bis-isobutyronitrile (abbreviated as AIBN), 1 Azo-biscyclohexane-1-carbonitrile, or 2,2'-azo-bis-2-methylbutyronitrile (2,2 ' -azo-bis-2-methyl butyronitrile), among which benzoyl peroxide, 2,2'-azo-bis-isobutyronitrile It is preferred.

The multifunctional polymerization initiator may be used alone or in combination. The multifunctional polymerization initiator may be 1,1-bis-t-butyl peroxy cyclohexane (abbreviated as TX -22), 1,1-bis-t-butyl peroxy-3,3,5-trimethyl cyclohexane (abbreviated as TX-29A 2,5-dimethyl-2,5-bis- (2-ethylhexanoxyperoxy) hexane), 4- (t-butyloxycarbonyloxy) Butylperoxycarbonyl) -3-hexyl-6- [7- (t-butylperoxycarbonyl) heptyl] cyclohexane- (t-butyl peroxy carbonyl) heptyl] cyclohexane, di-t-butyl-diperoxyazelate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane Di-t-butyl peroxy-hexahydroterephthalate (abbreviated BPHTH), or 2,2-bis (2-hydroxyethyl) (4,4-Ya-t-Bu But are not limited to, 2,2-bis- (4,4-di-t-butyl peroxy) cyclohexyl propane, abbreviated as PX-12.

In the solution copolymerization reaction, a chain transfer agent may be selectively added. The chain transfer agent may be used alone or in combination. The chain transfer agent may be selected from the group consisting of (1) mercaptan compounds such as methylmercaptan, n-butylmercaptan, cyclohexylmercaptan, n-dodecylmercaptan n- dodecyl mercaptan, NDM), stearyl mercaptan, t-dodecyl mercaptan (abbreviated as TDM), n-propyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, t-nonyl mercaptan, pentaerythritol tetrakis (3-mercapto propionate), pentaerythritol tetrakis (2-mercaptoethanate), pentaerythritol tetrakis mercapto ethanate), pentaerythritol tetrakis (4-mercapto butanate), pentaerythritol tetrakis (5-mercapto pentanate (5-mercaptobutanate) ), Pentaerythritol tetrakis (6-mercap Mercaptohexanate), trimethylolpropane tris (2-mercaptoethanate), trimethylolpropane tris (3-mercaptopropionate), and the like. (trimethylolpropane tris (3-mercapto propionate), abbreviated as TMPT), or trimethylolpropane tris (6-mercapto hexanate); (2) A method for producing an alkylamine-based compound, which is a compound selected from monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, monobutylamine, n-dibutylamine, Etc; (3) Other chain transfer agents include, but are not limited to, pentaphenylethane,? -Methylstyrene dimer, terpinolene, and the like. The chain transfer agent is preferably n-dodecyl mercaptan, t-dodecyl mercaptan, trimethylolpropane tris (3-mercaptopropionate), or a combination of the two. Further, the amount of the chain transfer agent to be used is, for example, 0 to 2 parts by weight, preferably 0.001 to 1 part by weight, based on 100 parts by weight of the reactant.

The operation temperature range of the solution copolymerization reaction is, for example, 70 to 140 ° C, and preferably 90 to 130 ° C.

≪ Second styrene-acrylonitrile copolymer >

In this embodiment, the method and the process for producing the second styrene-acrylonitrile-based copolymer are substantially the same as those of the first styrene-acrylonitrile-based copolymer, and the difference is that the second styrene-acrylonitrile- For example, 60 wt% to 69 wt% of a third styrene monomer unit, and 31 wt% to 40 wt% of a third acrylonitrile monomer unit. Here, the so-called monomer unit refers to a structural unit in which a third styrene-based monomer or a third acrylonitrile-based monomer is subjected to a polymerization reaction. The third styrene-based monomer may be selected from monomers listed in the second styrene-based monomer, and may be used alone or in combination of several kinds. The third acrylonitrile-based monomer may be used in combination with the second acrylonitrile-based monomer One of the monomers listed may be used alone or in combination of several.

<Rubber Graft Copolymer>

The rubber graft copolymer of the rubber-modified styrene type resin of this embodiment can be produced by graft polymerization of a rubber polymer and a copolymerizable monomer component. The rubber polymer includes, for example, but not limited to, diene rubber, polyacrylate rubber, or polysiloxane rubber, and it is preferable to use diene rubber alone or in combination.

For example, the rubber graft copolymer may be graft polymerized with an additive such as a rubber polymer (solid), a monomer component comprising a styrene-based monomer and an acrylonitrile-based monomer, and optionally an added emulsifier, polymerization initiator or chain transfer agent &Lt; / RTI &gt;

The rubber graft copolymer in the present embodiment may be prepared by graft polymerization of 2 to 90 parts by weight of a diene rubber and 98 to 10 parts by weight of a monomer mixture, wherein 100 parts by weight of the monomer mixture , Said monomer mixture comprises 40 to 90 parts by weight of a fourth styrenic monomer, 60 to 10 parts by weight of a fourth acrylonitrile monomer and 0 to 40 parts by weight of a second optional other copolymerizable monomer &Lt; / RTI &gt; Suspension, or emulsion polymerization method, respectively, and may be polymerized by a combination of such polymerization methods, for example, an emulsion-bulk or bulk-suspension polymerization method, and may be polymerized by emulsion polymerization, bulk polymerization Method and solution polymerization method.

The rubber-graft copolymer obtained by emulsion polymerization is graft-polymerized with 98 to 10 parts by weight of a monomer mixture in the presence of 2 to 90 parts by weight (dry weight) of a diene rubber emulsion , And an emulsion having a weight average particle diameter of 0.05 mu m to 0.8 mu m of rubber particles is prepared through the steps of condensation, dehydration and drying. The rubber content of the rubber graft polymer produced by the emulsion polymerization method is usually 25% by weight to 90% by weight, and preferably 45% by weight to 80% by weight.

The diene rubber may be used singly or in combination. Examples of the diene rubber include butadiene rubber, butadiene-styrene rubber, butadiene-acrylonitrile rubber and butadiene-methyl acrylonitrile rubber. The monomer may be directly polymerized in the form of a weight average particle diameter of 0.05 to 0.8 mu m, or may be first polymerized into a rubber emulsion of small particle diameter of 0.05 mu m to 0.18 mu m, The small particle size rubber emulsion having a size of 0.18 mu m may be enlarged to a rubber emulsion having a size of 0.2 mu m to 0.8 mu m. The above-mentioned gouging method can be a chemical non-conversion method of adding an organic acid or a polymer flocculant containing a metal salt or a carboxyl group, a mechanical agitating mechanical non-conversation method or a freezing non-conversation method. Among them, the polymer flocculant used in the chemical non- Methacrylic acid copolymer.

A method for producing a rubber graft copolymer obtained by using bulk or solution polymerization is a method in which, for example, 2 to 25 parts by weight of a diene rubber is previously dissolved in a monomer mixture of 98 to 75 parts by weight and optionally in a solvent Based on 100 parts by weight of the monomer mixture, the monomer mixture comprises 40 to 90 parts by weight of a fourth styrene-based monomer, 10 to 60 parts by weight of a fourth acrylonitrile-based monomer, and 0 to 40 parts by weight of A second other copolymerizable monomer, and then the resulting solution is pumped into a reactor to effect graft polymerization. The molecular weight of the polymer can be controlled by adding a suitable chain transfer agent, for example, t-dodecyl mercaptan, depending on the situation during the reaction. The reaction tank used can be constituted by combining a plurality of reaction tanks in series or in parallel, A tank reactor equipped with a stirrer is preferably used, and the solvent used may be toluene, xylene, ethylbenzene, methyl-ethyl ketone, ethyl acetate, and the like.

Examples of the diene rubber used in the bulk or solution polymerization method include those produced by polymerizing by the anionic polymerization method such as butadiene rubber, isoprene rubber, chlorobutadiene rubber, butadiene-acrylonitrile rubber, butadiene-styrene rubber and the like Among them, the butadiene rubber is distinguished from the Hi-Cis content and the low-Cis content. In the high sheath rubber, a typical weight composition of (94% to 98%) / (1% to 5%) of the cis / vinyl group and the remaining composition has a trans structure, Mooney viscosity, Is in the range of 20 to 120, and the molecular weight is in the range of 100,000 to 800,000. In low sheath rubbers, typical weight compositions of cis / ethylene groups are (20% to 40%) / (1% to 20%) and the remainder are trans structures and Mooney viscosity is between 20 and 120. Of the diene-based rubber graft copolymers of the bulk or solution polymerization method of the present embodiment, a suitable rubber is preferably butadiene rubber.

The rubber graft copolymer obtained by polymerizing by the bulk or solution polymerization method preferably has a weight-average particle diameter of, for example, from 0.6 탆 to 10 탆, and preferably from 0.9 탆 to 7 탆, , The rubber content of the rubber graft copolymer is preferably 4 wt% to 25 wt%, and preferably 8 wt% to 15 wt%, for example.

In addition to using the rubber graft copolymer of the emulsion polymerization method or the rubber (graft copolymer) of the bulk (or solution) polymerization method described above, the rubber graft copolymer of the present embodiment may be used in combination with the above- Among them, the bimodal distribution may be, for example, (1) a weight average particle diameter of 0.2 to 0.8 μm (emulsion polymerization), a weight average particle diameter of 0.6 to 10 μm (bulk or solution polymerization); Or (2) a weight average particle diameter of 0.05 to 0.18 mu m (emulsion polymerization) and a weight average particle diameter of 0.6 to 10 mu m (bulk or solution polymerization).

The three-point distribution is, for example, a weight average particle diameter of 0.05 to 0.15 m (emulsion polymerization), a weight average particle diameter of 0.17 to 0.8 m (emulsion polymerization) and a weight average particle diameter of 0.25 to 7.0 m Or solution polymerization).

The above-mentioned method of testing the weight average particle size of the rubber particles was carried out by dying the resin with osmium tetroxide (OsO ₄ ) and then photographing it with a transmission electron microscope. About 1000 pieces of the rubber-dispersed particles photographed in the photograph were taken and their particle diameters were measured Next, the weight average particle diameter is obtained by the following formula.

Rubber weight average particle diameter =

In the above formula, n is the number of rubber particles having a &quot; rubber particle diameter D &quot;.

Since the kind of the fourth styrene-based monomer used in the rubber graft copolymer of the present embodiment is the same as that of the second styrene-based monomer, the description of the fourth styrene-based monomer is omitted, and styrene or? -Methylstyrene .

Since the kind of the fourth acrylonitrile monomer used in the rubber graft copolymer of the present embodiment is the same as that of the second acrylonitrile monomer, the description of the second acrylonitrile monomer is omitted, Ronitril is preferred.

The second kind of other copolymerizable monomer used in the rubber graft copolymer of the present embodiment is the same as that of the first other copolymerizable monomer, and thus the description of the second other copolymerizable monomer is omitted. The second other copolymerizable monomer is methyl methacrylate , Butyl methacrylate, and N-phenylmaleimide.

The thermoplastic resin composition of the present embodiment may contain various additives such as an antioxidant, a lubricant, an ultraviolet absorber, an ultraviolet stabilizer, an antistatic agent, a colorant, and the like at a time of adding the branched copolymer or the rubber- A polymerization step of the resin or a kneading extrusion step.

The molded article of another embodiment of the present invention is formed from the thermoplastic resin composition as described above. There is no particular limitation on the method for producing the molded article, and it is possible to employ a heat molding, a vacuum molding or a combination of the above processes. The heat molding and the vacuum molding may be performed by a known method, and therefore, a description thereof will be omitted.

Hereinafter, the thermoplastic resin composition of the present invention will be described in more detail with reference to a plurality of experiments. Although the present invention is described in the following, it is to be understood that various changes and modifications may be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as limited by the following experiments.

The average rotation radius and weight average molecular weight of each component prepared by the following experiment are as follows.

<Average radius of rotation>

Multi-angle laser light scattering (MALLS) model DAWN8 + manufactured by Wyatt Technology using Gel Permeation Chromatography (GPC) manufactured by Waters and The model was measured in series with ViscoStar-II viscometer. Columns: MZ-Gel SDplus linear 5 μm, 300 mm × 8.0 mm, mobile phase: THF (flow rate 0.5 ml / min)

&Lt; Weight average molecular weight &

(Waters RI-2414) and an ultraviolet visible light detector (Waters PDA-2996) using Gel Permeation Chromatography (GPC) manufactured by Waters, Column: MZ-Gel SDplus linear 5 탆, 300 mm x 8.0 mm, mobile phase: THF (flow rate 0.5 ml / min).

Each component used in Experimental Example and Comparative Example is prepared as follows.

Synthesis of Bifunctional Copolymer (BHAS-1)

0.3 parts by weight of pentaerythritol tetrakis (3-mercaptopropionate), 71 parts by weight of styrene monomer, 29 parts by weight of acrylonitrile monomer, 150 parts by weight of ion-removing water, 0.4 parts by weight of calcium phosphate, 0.03 parts by weight Carboxyl group anionic surfactant, 0.01 part by weight of polyoxyethyl alkyl phosphate and 0.001 part by weight of 2,2'-azo-bis-isobutyronitrile initiator are added to one reactor and the reactor is completely sealed. The mixture was sufficiently stirred and dispersed, and then heated to raise the reaction temperature to 70 캜, and polymerization was carried out for 3 hours. After completion of the polymerization reaction, the reactor is cooled to room temperature to terminate the reaction. The obtained product was washed, dehydrated and dried to obtain a branched copolymer (BHAS-1) having a weight average molecular weight of 357,000 and an average rotation radius [R (avg)] of 80.7 nm.

Preparation of first styrene-acrylonitrile-based copolymer (A-1)

68 parts by weight of styrene, 32 parts by weight of acrylonitrile and 8 parts by weight of ethylbenzene were mixed and then 0.01 part by weight of t-dodecylmercaptan was further mixed. Then, at a flow rate of 35 kg / hr, And fed continuously into an oxidation reactor. That a volume of 40 liters of the reactor, and the internal temperature was maintained for 145 ℃, respectively, and the pressure is maintained for 4kg / cm ^2, the total conversion factor is about 55%.

After completion of the polymerization, the obtained copolymer solution is heated by a preheater, and volatile substances such as unreacted monomers and solvents are removed through a vacuum degassing vessel. Subsequently, the obtained polymer melt was extruded and granulated to obtain a first styrene resin having a weight average molecular weight of 210,000, a styrene monomer unit content of 72% and an acrylonitrile monomer unit content of 28% -Acrylonitrile-based copolymer (A-1).

Preparation of Second Styrene-acrylonitrile Copolymer (A-2)

55 parts by weight of styrene, 45 parts by weight of acrylonitrile and 8 parts by weight of ethylbenzene were mixed and continuously fed into the continuous reactor until fully mixed at a flow rate of 35 kg / hr. That a volume of 40 liters of the reactor, and the internal temperature was maintained for 145 ℃, respectively, and the pressure is maintained for 4kg / cm ^2, the total conversion factor is about 55%.

After completion of the polymerization, the obtained copolymer solution is heated by a preheater, and volatile substances such as unreacted monomers and solvents are removed through a vacuum degassing vessel. Subsequently, the obtained polymer melt was extruded (granulated) to obtain a second styrene resin having a weight average molecular weight of 140,000, a styrene monomer unit content of 67% and an acrylonitrile monomer unit content of 33% -Acrylonitrile-based copolymer (A-2).

Preparation of Rubber Graft Copolymer (B-1)

150.00 parts by weight of 1,3-butadiene, 15.00 parts by weight of potassium persulfate solution (concentration of 1% by weight), 2.00 parts by weight of potassium oleate, 0.13 parts by weight of ethylene glycol dimethacrylate and 190.00 parts by weight of distilled water, And reacted for 14 hours to obtain a rubber emulsion having a weight average particle diameter of 0.1 탆 (conversion rate: 94%, solid content: about 36%).

(Concentration: 1% by weight), 0.50 parts by weight of sodium dodecylsulfate solution (concentration: 10% by weight), 1.00 parts by weight of n-dodecyltrimethylammonium hydroxide Silmercaptan and 200.00 parts by weight of distilled water were reacted at a reaction temperature of 75 DEG C for 5 hours to obtain a polymer flocculant solution of carboxyl group having a conversion of about 95% and a pH value of 6.0.

Thereafter, 100 parts by weight of the rubber latex is extruded using a polymer flocculant containing 3 parts by weight (dry weight) of carboxyl groups. The obtained rubber latex has a pH value of 8.5 and a rubber weight average particle diameter of about 0.3 μm.

300.0 parts by weight of the non-saponified rubber latex (dry weight), 75.0 parts by weight of styrene, 25.0 parts by weight of acrylonitrile, 2.0 parts by weight of t-dodecyl mercaptan, 3.0 parts by weight of cumene hydrogen peroxide, 3.0 parts by weight of ferrous sulfate solution 0.2 weight%), 0.9 weight part formaldehyde sodium sulfoxylate (concentration 10 weight%) and 3.0 weight part ethylenediaminetetraacetic acid solution (concentration 0.25 weight%) were grafted with styrene acrylonitrile copolymer Followed by a polymerization reaction to prepare a rubber graft copolymer. The prepared rubber graft copolymer emulsion was coagulated with calcium chloride and dehydrated to 2% or less and dried to obtain a rubber graft copolymer (B-1) having a weight average particle diameter of 0.31 mu m and a rubber content of 75 wt% ) Can be produced.

Preparation of Rubber Graft Copolymer (B-2)

6.6 parts by weight of polybutadiene (Asadene 55AS, trade name) was completely dissolved in 74.4 parts by weight of styrene, 25.6 parts by weight of acrylonitrile and 30 parts by weight of ethylbenzene, using 0.08 part by weight of benzoyl peroxide as an initiator, And the feed solution is continuously introduced into a first reactor having a volume of 45 liters. The reaction temperature is 100 DEG C, and a spiral stirrer equipped with a cooling circulation tube is disposed inside the reactor, and the stirring speed is 150 rpm. The monomer conversion rate of the first reactor was 15%. The reacted mixture was continuously taken out through the first reactor and sequentially transferred to the second, third and fourth reactors, and 0.1 part by weight of t-dodecane Silmercaptan is introduced, and the phase reversal phenomenon occurs in the second reactor. The apparatuses of the second, third and fourth reactors are the same as those of the first reactor except that the reaction temperatures are sequentially 105 ° C, 110 ° C and 125 ° C, and the stirring speed is 270 rpm, 150 rpm and 110 rpm, respectively. When the conversion rate of the mixture reached 60%, the mixture was taken out and transferred to a devolatilizer to remove unreacted monomers and volatile components, and the mixture was extruded and assembled. When the weight average particle diameter of the rubber particles was 0.95 mu m and the rubber content was 10 wt% % Of the graft copolymer (B-2) can be produced.

Preparation of Experimental Examples 1 to 6

37.59 parts by weight of the first styrene-acrylonitrile copolymer (A-2), based on 100 parts by weight of the rubber-modified styrene resins (A-1, A-2, B-1 and B- 37.59 parts by weight of a second styrene-acrylonitrile copolymer (A-2), 17.73 parts by weight of a rubber graft copolymer (B-1) and 7.09 parts by weight of a rubber graft copolymer (B- (Model: ZPT-25, manufacturer: Sawaku Kogyo Co., Ltd.), and the blending ratio to the branched copolymer (BHAS-1) shown in Tables 1 and 2 was applied. Then, 2.0 parts by weight of a lubricant And further kneaded at a kneading temperature of 220 ° C and then extruded by a twin-screw extruder to obtain the thermoplastic resin compositions of Experimental Examples 1 to 6.

The extensional viscosity and shear viscosity of each of the thermoplastic resin compositions prepared in the above experiment were measured by the following measuring methods, and the results are shown in Tables 1 and 2.

<Elongation viscosity>

Using a Rheometer ARES-G2 manufactured by TA Instruments, the temperature was measured at 170 占 폚 and the shear rate was measured at 0.5 / s.

<Shear viscosity ratio>

Using a Rheometer ARES-G2 manufactured by TA Instruments, the temperature was measured at 230 占 폚 and the shear rate was measured at 100 / s.

Experimental Example 1 Experimental Example 2 Experimental Example 3 Rubber-modified styrene resin B-1 Weight portion 17.73 17.73 17.73 B-2 Weight portion 7.09 7.09 7.09 A-1 Weight portion 37.59 37.59 37.59 A-2 Weight portion 37.59 37.59 37.59 A-1 / A-2 Weight% / weight% 50/50 50/50 50/50 BHAS-1 Weight portion 2.5 3 4 R.C% weight% 14 14 14 Shear viscosity rate
(230 DEG C * 100 / s) Pa * sec 1513 1508 1516 Elongation viscosity
(170 DEG C * 0.5 / s) Pa * sec 952131 1090034 1102379

A-1: First styrene-acrylonitrile copolymer

A-2: Second styrene-acrylonitrile copolymer

B-1: Rubber graft copolymer

B-2: Rubber graft copolymer

BHAS-1: Branched copolymer

R.C%: Total rubber content

(Table 1 Continuous) Experimental Example 4 Experimental Example 5 Experimental Example 6 Rubber-modified styrene resin B-1 Weight portion 17.73 17.73 17.73 B-2 Weight portion 7.09 7.09 7.09 A-1 Weight portion 37.59 37.59 37.59 A-2 Weight portion 37.59 37.59 37.59 A-1 / A-2 Weight% / weight% 50/50 50/50 50/50 BHAS-1 Weight portion 6 2 8 R.C% weight% 14 14 14 Shear viscosity rate
(230 DEG C * 100 / s) Pa * sec 1525 1520 1575 Elongation viscosity
(170 DEG C * 0.5 / s) Pa * sec 1112390 852122 1126555

In the results of Tables 1 and 2, in addition to the use of the branched copolymer, the thermoplastic resin compositions of Experimental Examples 1 to 6 were prepared by mixing the first styrene-acrylonitrile-based A styrene-acrylonitrile copolymer containing a copolymer (A-1) and a second styrene-acrylonitrile copolymer (A-2) having a weight average molecular weight of 140,000 was further added. Based on 100% by weight of the total content of the first styrene-acrylonitrile copolymer (A-1) and the second styrene-acrylonitrile copolymer (A-2), the first styrene- The content of the styrenic copolymer (A-1) and the content of the second styrene-acrylonitrile copolymer (A-2) were respectively 50% by weight. Thus, the thermoplastic resin compositions of Experiments 1 to 6 It has a relatively low shear viscosity and an excellent extensional viscosity, and can have both sheet extrusion and vacuum formability.

In detail, in Experimental Examples 1 to 6, the content of the branched copolymer was limited within the range of 1.5 to 8 parts by weight based on 100 parts by weight of the rubber-modified styrene resin, As a result of further restricting the content of the branched copolymer contained in Example 4 to within the range of 2.5 to 6 parts by weight, all of the shear rates exhibited a relatively low shear viscosity as compared with the shear viscosity of Experimental Example 6. [

On the other hand, in the known technique, since the shear viscosity can rise as the content of the branched copolymer increases, the properties of the sheet extruding property are not ideal. However, in Experiments 1 to 5 of Tables 1 and 2 The results show that the present invention can improve the above drawbacks. For example, the shear viscosity of Experimental Example 4 containing 6 parts by weight of the branched copolymer is almost the same as that of Experimental Example 5 containing 2 parts by weight of the branched copolymer, 5 &lt; / RTI &gt;

Preparation of Comparative Examples 1 to 7

The manufacturing method of the thermoplastic resin compositions of Comparative Examples 1 to 7 is the same as that of Experimental Examples 1 to 6 except that Comparative Examples 1 to 7 are prepared by mixing the components listed in Tables 3 and 4 The shear viscosity and elongational viscosity were measured in the same manner as described above, and the results are shown in Tables 3 and 4.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Rubber-modified styrene resin B-1 Weight portion 17.73 17.73 17.73 17.73 B-2 Weight portion 7.09 7.09 7.09 7.09 A-1 Weight portion 30.072 30.072 30.072 45.108 A-2 Weight portion 45.108 45.108 45.108 30.072 A-1 / A-2 Weight% / weight% 40/60 40/60 40/60 60/40 BHAS-1 Weight portion 2 2.5 3 2 R.C% weight% 14 14 14 14 Shear viscosity rate
(230 DEG C * 100 / s) Pa * sec 1498 1519 1541 1577 Elongation viscosity
(170 DEG C * 0.5 / s) Pa * sec 710223 831449 924110 818020

A-1: First styrene-acrylonitrile copolymer

A-2: Second styrene-acrylonitrile copolymer

B-1: Rubber graft copolymer

B-2: Rubber graft copolymer

BHAS-1: Branched copolymer

R.C%: Total rubber content

Table 3 (continued) Comparative Example 4 Compare 5 Comparative Example 6 Rubber-modified styrene resin B-1 Weight portion 17.73 17.73 17.73 B-2 Weight portion 7.09 7.09 7.09 A-1 Weight portion 45.108 45.108 75.18 A-2 Weight portion 30.072 30.072 0 A-1 / A-2 Weight% / weight% 60/40 60/40 100/0 BHAS-1 Weight portion 2.5 3 3 R.C% weight% 14 14 14 Shear viscosity rate
(230 DEG C * 100 / s) Pa * sec 1630 1672 1791 Elongation viscosity
(170 DEG C * 0.5 / s) Pa * sec 954381 869104 1093517

In the results of Tables 3 and 4, the thermoplastic resin compositions of Comparative Examples 1 to 6 were similarly prepared using a branched copolymer and two kinds of styrene-acrylonitrile copolymers in a specific ratio, but the shear viscosity and the elongation viscosity Are significantly worse than those of Experimental Examples 1 to 6. For example, in Comparative Examples 1 to 3, the total content of the first styrene-acrylonitrile copolymer (A-1) and the second styrene-acrylonitrile copolymer (A-2) The content of the first styrene-acrylonitrile copolymer (A-1) was 40 wt%, the content of the second styrene-acrylonitrile copolymer (A-2) was 60 wt% That is, the content of the first styrene-acrylonitrile copolymer (A-1) is lower than 45% by weight and the content of the second styrene-acrylonitrile copolymer (A-2) is higher than 55% , And thus even if the content of the branched copolymer is within the range of 1 to 10 parts by weight, the elongational viscosity of Comparative Examples 1 to 3 is still low.

Further, in Comparative Examples 4 to 6, the total content of the first styrene-acrylonitrile copolymer (A-1) and the second styrene-acrylonitrile copolymer (A-2) The content of the first styrene-acrylonitrile copolymer (A-1) was 60% by weight and the content of the second styrene-acrylonitrile copolymer (A-2) was 40% The content of the first styrene-acrylonitrile copolymer (A-1) is higher than 55% by weight, the content of the second styrene-acrylonitrile copolymer (A-2) is lower than 45% The shear viscosity measured in Comparative Examples 4 to 6 indicates relatively higher shear viscosity than the experimental examples, even if the content of the branched copolymer is within the range of 1 to 10 parts by weight.

On the other hand, when comparing the experimental examples and the comparative examples using the same weight part of the branched copolymer, for example, 2 parts by weight of the branched copolymer in Experimental Example 5, Comparative Example 1 and Comparative Example 4 were used, And Comparative Example 1, although the shear viscosity ratio of Comparative Example 1 was slightly lower than the shear viscosity ratio of Experimental Example 5, Experimental Example 5 had a rather excellent elongation viscosity; In Experimental Example 5 and Comparative Example 4, in Comparative Example 4, although the elongation viscosity was improved, the shear viscosity ratio also increased accordingly. In comparison, in Experimental Example 5, the elongation viscosity was increased and the shear viscosity was also considered , The test sample 5 had comparatively good sheet extrusion and vacuum formability as compared with Comparative Examples 1 and 4.

In Example 2 and Comparative Examples 3, 6 and 7, 3 parts by weight of a branched copolymer was used. Among them, the first styrene-acrylonitrile copolymer (A-1) of Comparative Example 3 and Comparative Example 6 ) And the content of the second styrene-acrylonitrile copolymer (A-2) exceeded the range of 45% by weight to 55% by weight, the shear viscosity and elongational viscosity were worse than in Experiment 2; In Comparative Example 7, although the elongational viscosity increased through the branched copolymer, in Comparative Example 7, since only a single styrene-acrylonitrile-based copolymer was used, the shear viscosity ratio of the thermoplastic resin composition could not be effectively lowered, Which is lower than Experimental Example 2 in terms of application to processing.

In conclusion, the thermoplastic resin composition of the present invention includes a branched copolymer and a rubber-modified styrene resin. Wherein the branched copolymer comprises a tetrathiol compound unit, a first styrene monomer unit and a first acrylonitrile monomer unit; The rubber-modified styrenic resin comprises a continuous phase formed from 70% by weight to 90% by weight of a styrenic copolymer and a dispersed phase formed from 10% by weight to 30% by weight of rubber particles, wherein the styrene- Styrene-acrylonitrile copolymer and a second styrene-acrylonitrile copolymer, wherein the weight average molecular weight of the first styrene-acrylonitrile copolymer and the weight of the second styrene-acrylonitrile copolymer The average molecular weight is different; The content of the first styrene-acrylonitrile-based copolymer is from 45% by weight to 55% by weight based on 100% by weight of the total content of the first styrene-acrylonitrile-based copolymer and the second styrene-acrylonitrile- %, And the content of the second styrene-acrylonitrile-based copolymer is 45 wt% to 55 wt%. By using the first styrene-acrylonitrile-based copolymer and the second styrene-acrylonitrile-based copolymer mixed in the thermoplastic resin composition with the branched copolymer and the specific ratio, the thermoplastic resin composition of the present invention is excellent in sheet extrusion performance and vacuum It is possible to combine moldability.

Although the present invention has been disclosed by way of example, the present invention is not limited to the above-described embodiments, but various changes and modifications may be made without departing from the spirit and scope of the present invention. And the scope of protection of the present invention is therefore limited to those defined in the appended claims.

Claims (13)

As the thermoplastic resin composition,
A branched copolymer comprising a tetrathiol compound unit, a first styrene-based monomer unit and a first acrylonitrile-based monomer unit; And
A continuous phase formed of 70 to 90 wt% of a styrenic copolymer, and a dispersed phase of 10 to 30 wt% of rubber particles,
Wherein the styrenic copolymer comprises a first styrene-acrylonitrile copolymer and a second styrene-acrylonitrile copolymer,
Wherein the first styrene-acrylonitrile-based copolymer comprises 71 wt% to 74 wt% of a second styrene-based monomer unit and 26 wt% to 29 wt% of a second acrylonitrile-based monomer unit, Wherein the styrene-acrylonitrile-based copolymer comprises 60 wt% to 69 wt% of a third styrene-based monomer unit and 31 wt% to 40 wt% of a third acrylonitrile-based monomer unit,
The weight average molecular weight of the first styrene-acrylonitrile copolymer is 180,000 to 240,000, the weight average molecular weight of the second styrene-acrylonitrile copolymer is 110,000-170,000,
The content of the first styrene-acrylonitrile-based copolymer and the second styrene-acrylonitrile-based copolymer may be 45% by weight or less based on 100% by weight of the total content of the first styrene- To 55% by weight, and the content of the second styrene-acrylonitrile-based copolymer is 45% by weight to 55% by weight,
Wherein the rubber particles have a bimodal distribution of a weight-average particle diameter in the range of 0.2 탆 to 0.8 탆 and 0.6 탆 to 10 탆. The method according to claim 1,
The content of the first styrene-acrylonitrile-based copolymer and the second styrene-acrylonitrile-based copolymer may be 50% by weight or less based on 100% by weight of the total content of the first styrene-acrylonitrile- And the content of the second styrene-acrylonitrile-based copolymer is 50% by weight. The method according to claim 1,
Wherein the content of the branched copolymer is 1 part by weight to 10 parts by weight based on 100 parts by weight of the rubber-modified styrene resin. The method of claim 3,
Wherein the content of the branched copolymer is 1.5 parts by weight to 8 parts by weight based on 100 parts by weight of the rubber-modified styrene resin. 5. The method of claim 4,
Wherein the content of the branched copolymer is from 2.5 parts by weight to 6 parts by weight based on 100 parts by weight of the rubber-modified styrene resin. The method according to claim 1,
Wherein the average radius of gyration of the branched copolymer is from 75 nanometers to 110 nanometers. The method according to claim 6,
Wherein the branched copolymer has an average rotation radius of 80 nanometers to 100 nanometers. The method according to claim 1,
Wherein the branched copolymer has a weight average molecular weight of from 1 million to 7,000,000. 9. The method of claim 8,
Wherein the branched copolymer has a weight average molecular weight of 2,000,000 to 5,000,000. The method according to claim 1,
Wherein the tetrathiol compound unit is formed from a tetrathiol compound. 11. The method of claim 10,
The tetrathiol compound is preferably selected from the group consisting of pentaerythritol tetrakis (3-mercapto propionate), pentaerythritol tetrakis (2-mercapto (2-mercapto) pentaerythritol tetrakis (4-mercapto butanate), pentaerythritol tetrakis (5-mercapto pentanate), pentaerythritol tetrakis (5-mercapto pentanate) , And pentaerythritol tetrakis (6-mercapto hexanate). The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is a thermoplastic resin composition. 12. The method of claim 11,
Wherein the tetrathiol compound is pentaerythritol tetrakis (3-mercapto propionate). 2. The thermoplastic resin composition according to claim 1, wherein the tetrathiol compound is pentaerythritol tetrakis (3-mercapto propionate). A molded article formed from the thermoplastic resin composition of any one of claims 1 to 12.