TW201720864A - Thermoplastic resin composition and molding product made therefrom - Google Patents

Abstract

A thermoplastic resin composition and a molding product made therefrom are provided. The thermoplastic resin composition includes a rubber modified styrene series resin and a branched copolymer. The weight average molecular weight of the branched copolymer is between one million and seven million. The branched copolymer includes a tetrathiol compound unit, a styrene series monomer unit, and an acrylonitrile series monomer unit.

Description

Thermoplastic resin composition and molded article thereof

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

The thermoplastic styrene resin is well evaluated for its formability, physical properties, and mechanical properties, and the molded article has a good appearance and gloss, which is widely used in electronics. In addition to electrical appliances and automotive parts, it is especially suitable for the processing of refrigerator plates.

In general, the thermoplastic styrene-based resin can be processed by a molding method such as injection molding, extrusion molding, or blow molding. In the case of specific processing, such as thermoforming or vacuum forming, the thermoplastic styrene resin is firstly pressed into a sheet and then formed into a desired molded article; The thermoplastic styrene resin is processed to impart a good shear viscosity and an excellent elongation viscosity to the thermoplastic styrene resin, and to maintain a good slab during thermoforming or vacuum forming. Sex and vacuum formability. Although related research has proposed the use of linear copolymers as processing aids for this purpose, it is not possible to increase the elongational viscosity of thermoplastic styrenic resins while reducing the shear viscosity, which makes them more limited in processing.

The present invention provides a thermoplastic resin composition and a molded article formed from the above composition, which greatly improves vacuum forming properties and maintains good sheeting characteristics.

A thermoplastic resin composition of the present invention comprising a rubber-modified styrene-based resin, and a condensed copolymer having a weight average molecular weight of 1,000,000 to 7,000,000, and the divergent copolymer comprises four A thiol compound unit, a styrene monomer unit, and an acrylonitrile monomer unit.

In an embodiment of the invention, the divergent copolymer has an average radius of gyration of from 75 nm to 110 nm.

In an embodiment of the invention, the above-mentioned branched copolymer has a weight average molecular weight of 2,000,000 to 5,000,000.

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

In one embodiment of the present invention, the content of the condensed copolymer is from 1 part by weight to 8 parts by weight based on 100 parts by weight of the rubber-modified styrene resin.

In an embodiment of the invention, the content of the dicrotene copolymer is from 1.5 parts by weight to 6 parts by weight based on 100 parts by weight of the rubber-modified styrene-based resin.

In one embodiment of the present invention, the content of the dicroform copolymer is from 2 parts by weight to 4 parts by weight based on 100 parts by weight of the rubber-modified styrene resin.

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

In an embodiment of the invention, the tetrathiol compound is selected from the group consisting of pentaerythritol tetrakis (3-mercapto propionate) and tetrakis(2-mercaptoacetic acid) pentaerythritol [pentaerythritol tetrakis (2) -mercapto ethanate)], pentaerythritol tetrakis (4-mercapto butanate), pentaerythritol tetrakis (5-mercapto pentanate), and tetra (4-mercapto butanate) At least one of the group consisting of: 6-mercapto hexanate; 6-mercapto hexanate.

In an embodiment of the invention, the tetrathiol compound is pentaerythritol tetrakis (3-mercapto propionate).

In an embodiment of the invention, the styrene monomer unit is a styrene monomer unit.

In an embodiment of the invention, the acrylonitrile monomer unit is an acrylonitrile monomer unit.

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

Based on the above, the thermoplastic resin composition of the present invention contains a divalent copolymer having a tetrathiol compound unit having a weight average molecular weight of 1,000,000 to 7,000,000, which is made of a thermoplastic resin composition. The resulting molded article has excellent shear viscosity and elongational viscosity, and is particularly suitable for vacuum forming applications of sheets.

The above described features and advantages of the present invention will be more apparent from the following description.

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

In an embodiment of the invention, the thermoplastic resin composition comprises a rubber-modified styrene-based resin and a condensed copolymer having a weight average molecular weight of 1,000,000 to 7,000,000, and the divergent copolymerization The material includes a tetrathiol compound unit, a styrene monomer unit, and an acrylonitrile monomer unit. Here, the term "compound unit" means a structural unit formed by copolymerization of a tetrathiol compound, and the monomer unit means a structural unit formed by copolymerization of a styrene monomer or an acrylonitrile monomer. And the content of the conjugated copolymer is from 1 part by weight to 10 parts by weight based on 100 parts by weight of the rubber-modified styrene-based resin, and preferably, the content of the condensed copolymer is from 1 part by weight to 8 parts by weight, more preferably, the content of the condensed copolymer is from 1.5 parts by weight to 6 parts by weight, and most preferably, the content of the condensed copolymer is from 2 parts by weight to 4 parts by weight; The ingredients mentioned.

Divided copolymer

The dicromeric copolymer of the present invention contains a tetrathiol compound unit, a styrene monomer unit, and an acrylonitrile monomer unit. The tetrathiol compound unit may be formed of a tetrathiol compound, for example, by removing a hydrogen on a thiol group from a tetrathiol compound. The tetrathiol compound is, for example, selected from the group consisting of pentaerythritol tetrakis (3-mercapto propionate), pentaerythritol tetrakis (2-mercapto ethanate), and tetrakis(2-mercapto propionate). Pentaerythritol tetrakis (4-mercapto butanate), pentaerythritol tetrakis (5-mercapto pentanate), and tetrakis(6-mercaptohexanoic acid) At least one of a group consisting of pentaerythritol tetrakis (6-mercapto hexanate); in this embodiment, the tetrathiol compound is tetrakis(3-mercaptopropionic acid) pentaerythritol [pentaerythritol tetrakis (3) -mercapto propionate)] is better. In the present embodiment, when the dichroic copolymer is synthesized, the total amount of the styrene monomer and the acrylonitrile monomer used for the synthesis of the branched copolymer is 100 parts by weight, and 0.3, 0.6 or 1.0 can be used. Parts by weight of tetrakis(3-mercaptopropionic acid) pentaerythritol, but is not limited thereto.

The styrene monomer unit is preferably a styrene monomer unit; and the acrylonitrile monomer unit is preferably an acrylonitrile monomer unit. Here, the monomer unit means a structural unit formed by copolymerization of a styrene monomer or an acrylonitrile monomer.

The above styrenic monomers may be used singly or in combination, and the styrenic monomers include, but are 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 styrene, alpha-methyl styrene, or a combination thereof.

The above acrylonitrile-based monomers may be used singly or in combination, and the acrylonitrile-based monomers include, but are not limited to, acrylonitrile or α-methacrylonitrile. Preferably, the acrylonitrile monomer is acrylonitrile.

The branched copolymer of the present embodiment can be produced by a conventional method known in the art, such as emulsion polymerization, bulk (bulk) polymerization, suspension polymerization, and solution polymerization, and the average radius of gyration of the obtained bifurcated copolymer is preferably. It is from 75 nm to 110 nm, more preferably from 80 nm to 100 nm; the weight average molecular weight is preferably from 1,000,000 to 7,000,000, more preferably from 2,000,000 to 5,000,000.

Rubber modified styrene resin

The rubber-modified styrene-based resin of the present embodiment can be composed, for example, of a continuous phase formed of a styrene-based copolymer and a dispersed phase formed of rubber particles, and the rubber particles comprise a rubber polymer and grafted onto the rubber polymer. Branch copolymer. The method for producing a rubber-modified styrene-based resin may be a simultaneous grafting method or a grafting and kneading method in which a rubber component (such as a rubber polymer) is added to a polymerization of a styrene-based copolymer. In the reaction process, a rubber-modified styrene resin is obtained by participating in a polymerization reaction; the grafting and kneading method is a rubber component (such as a rubber polymer or a rubber graft copolymer, particularly a rubber graft copolymer) The styrene-based copolymer is directly kneaded by a biaxial extruder, and then extruded into a rubber-modified styrene-based resin; wherein a slip agent may be added together for mixing.

The polymerization reaction in the method for producing the rubber-modified styrene resin is, for example, but not limited to, a bulk polymerization method, a solution polymerization method, an emulsion polymerization method, a bulk suspension polymerization method, or the like.

< Rubber graft copolymer >

The rubber-grafted copolymer of the rubber-modified styrene resin of the present embodiment can be obtained by graft polymerization of a rubber polymer and a copolymerizable monomer component. The rubber polymer is, for example but not limited to, a diene rubber, a polyacrylate rubber or a polyoxyalkylene rubber. Among them, a diene rubber is preferred, and it may be used singly or in combination.

For example, the rubber graft copolymer may be a rubber polymer (solid content), a monomer component containing a styrene monomer and an acrylonitrile monomer, and an optionally added emulsifier, polymerization initiation. Additives such as a reagent or a chain transfer agent are obtained by graft polymerization.

The rubber graft copolymer of the rubber-modified styrene resin of the present embodiment may be obtained by graft polymerization of 2 parts by weight to 90 parts by weight of the diene rubber, and 98 parts by weight to 10 parts by weight of the monomer mixture, wherein The monomer mixture may contain 40 parts by weight to 90 parts by weight of the styrene-based monomer, 60 parts by weight to 10 parts by weight of the acrylonitrile-based monomer, and 0 part by weight to 100 parts by weight of the monomer mixture. 40 parts by weight of optional copolymerizable monomers; which can be obtained by polymerization by bulk, solution, suspension or emulsion polymerization, respectively, or by a combination of these polymerization methods, such as emulsification-block The method of bulk or block-suspension polymerization is preferably an emulsion polymerization method, a bulk polymerization method, and a solution polymerization method.

The method for producing a rubber graft copolymer obtained by emulsion polymerization may be grafted in a presence of from 2 parts by weight to 90 parts by weight (dry weight) of the diene rubber emulsion, and from 98 parts by weight to 10 parts by weight of the monomer mixture. The emulsion obtained by polymerizing the rubber particles having a weight average particle diameter of 0.05 μm to 0.8 μm is obtained by a step of coagulation, dehydration, drying, and the like. The rubber graft copolymer obtained by the above emulsion polymerization method usually has a rubber content of from 25% by weight to 90% by weight, preferably from 45% by weight to 80% by weight.

The above diene rubber may be used singly or in combination, such as, but not limited to, butadiene rubber, butadiene-styrene rubber, butadiene-acrylonitrile rubber or butadiene-methacrylonitrile rubber, and the like. It is a butadiene rubber which can be directly polymerized into a weight average particle diameter of 0.05 μm to 0.8 μm, or can be first polymerized into a small particle size rubber emulsion of 0.05 μm to 0.18 μm, and then subjected to a conventional rubber fat method. a rubber emulsion of a small particle size of 0.05 μm to 0.18 μm is formed into a rubber emulsion of 0.2 μm to 0.8 μm, and the rubber fat method may be a chemical fertilizer method of adding an organic acid or a metal salt or a polymer aggregating agent containing a carboxylic acid group. Mechanical agglomeration of mechanical agitation or frozen fat method, etc., wherein the polymer agglutinating agent used in the chemical fertilizer method can use butyl acrylate-methacrylic acid copolymer.

In the method for producing a rubber graft copolymer obtained by bulk or solution polymerization, for example, 2 parts by weight to 25 parts by weight of the diene rubber may be previously dissolved in 98 parts by weight to 75 parts by weight of the monomer mixture and In the solvent to be selected, the monomer mixture may include 40 parts by weight to 90 parts by weight of the styrene monomer, and 10 parts by weight to 60 parts by weight of the acrylonitrile system based on 100 parts by weight of the monomer mixture. Monomer and 0 to 40 parts by weight of other copolymerizable monomers, and then pumping the resulting solution into a reaction tank for graft polymerization, optionally adding a chain transfer agent during the reaction, for example, a third - dodecyl mercaptan to control the molecular weight of the polymer, and the reaction tank used may be a combination of a plurality of tanks connected in series or in parallel, preferably a kettle-shaped reaction tank with a strong agitator, and the solvent used may be toluene, Xylene, ethylbenzene, methyl-ethyl ketone, ethyl acetate, and the like.

The diene rubber used in the bulk or solution polymerization method is preferably obtained by an anionic polymerization method, such as butadiene rubber, isoprene rubber, chloroprene rubber, butadiene-propylene. Nitrile rubber, butadiene-styrene rubber, etc., wherein butadiene rubber has high cis (Hi-Cis) content and low cis (Los-Cis) content; in high cis rubber, cis ( The typical weight composition of Cis)/Vinyl is 94% to 98%/1% to 5%, and the rest of the composition is trans structure with a Mooney viscosity of 20 to 120 and a molecular weight range of 10 Ten thousand to 800,000 is preferred. In the low cis rubber, the typical weight composition of cis/vinyl is 20% to 40%/1% to 20%, and the rest is a trans structure with a Mooney viscosity of 20 to 120. In the diene rubber graft copolymer of the block or solution polymerization method of the present embodiment, a suitable rubber is preferably a butadiene rubber.

a rubber graft copolymer obtained by polymerization in a bulk or solution polymerization method, wherein the weight average particle diameter of the rubber particles is generally from 0.6 μm to 10 μm, preferably from 0.9 μm to 7 μm, which is obtained by the bulk or solution polymerization method. The rubber graft copolymer has a rubber content of usually 4% by weight to 25% by weight, preferably 8% by weight to 15% by weight.

The rubber graft copolymer of the present embodiment may be used in addition to the rubber graft copolymer of the emulsion polymerization method or the rubber graft copolymer of the bulk (or solution) polymerization method. Forming a bimodal or trimodal distribution, wherein the bimodal distribution is as follows: (1) a weight average particle diameter of 0.2 μm to 0.8 μm (emulsification polymerization), a weight average particle diameter of 0.6 μm to 10 μm (block or solution polymerization); Or (2) a weight average particle diameter of 0.05 μm to 0.18 μm (emulsification polymerization), and a weight average particle diameter of 0.6 μm to 10 μm (block or solution polymerization).

The three-peak type distribution is, for example, a weight average particle diameter of 0.05 μm to 0.15 μm (emulsification polymerization), a weight average particle diameter of 0.17 μm to 0.8 μm (emulsification polymerization), and a weight average particle diameter of 0.25 μm to 7.0 μm (block or solution). polymerization).

The method for testing the weight average particle diameter of the rubber particles is to dye the resin with osmium tetroxide (OsO ₄ ), and then take a transmission electron microscope to take about 1000 pieces of rubber dispersed particles in the photograph. The particle size is determined by the following formula:

n in the above formula is the number of rubber particles having a rubber particle diameter D.

The styrene monomer used in the rubber graft copolymer of the present embodiment may be used singly or in combination, such as but not limited to styrene, α-methylstyrene, α-chlorostyrene, p-tert-butylstyrene. , p-methylstyrene, o-chlorostyrene, p-chlorostyrene, 2,5-dichlorostyrene, 3,4-dichlorostyrene, 2,4,6-trichlorostyrene or 2 , 5-dibromostyrene, and the like. Preferred styrenic monomers may be selected from the group consisting of styrene, alpha-methyl styrene or combinations of the foregoing.

The acrylonitrile-based monomer used in the rubber graft copolymer of the present embodiment may be used singly or in combination, and examples thereof include, but are not limited to, acrylonitrile, α-methacrylonitrile, and the like. A preferred acrylonitrile monomer is acrylonitrile.

Other copolymerizable monomers used in the rubber graft copolymer of this embodiment may be used singly or in combination, such as, but not limited to, acrylate monomers, methacrylate monomers, and monofunctional maleimide. It is a monomer or the like.

Specific examples of the acrylate-based monomer include methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, polyethylene glycol diacrylate, and the like. A preferred acrylate monomer is butyl acrylate.

Specific examples of the methacrylate monomer include: methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate, hexyl methacrylate, Cyclohexyl methacrylate, dodecyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, ethylene dimethacrylate (ethylene Dimethacrylate), neopentyl dimethacrylate, and the like. Preferred methacrylate monomers are methyl methacrylate and butyl methacrylate.

Specific examples of the monofunctional maleimide-based monomer include: maleic imine, N-methyl maleimide, N-isopropyl maleimide, N-butyl mala Yttrium, N-hexylmaleimide, N-octylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, N-phenyl horse醯imine, N-2-methylphenylmaleimide, N-2,3-dimethylphenylmaleimide, N-2,4-dimethylphenyl mala Imine, N-2,3-diethylphenylmaleimide, N-2,4-diethylphenylmaleimide, N-2,3-dibutylphenyl Malay Yttrium, N-2,4-dibutylphenylmaleimide, N-2,6-dimethylphenylmaleimide, N-2,3-dichlorophenylmale Yttrium, N-2,4-dichlorophenylmaleimide, N-2,3-dibromophenylmaleimide or N-2,4-dibromophenylmalazone Amines, etc. A preferred monofunctional maleimide monomer is N-phenylmaleimide.

In addition, other copolymerizable monomers, such as acrylic monomers (eg, acrylic acid, methacrylic acid), anhydrous maleic acid, anhydrous methyl maleic acid, anhydrous methyl fumaric acid, fumaric acid (fumaric acid), an unsaturated carboxylic acid compound such as itaconic acid, and an esterification monomer thereof (for example, dimethyl fumarate, dibutyl itaconate), ethylene, propylene, 1-butyl Alkene, 1-pentene, 4-methyl 1-pentene, ethylene chloride, vinyl chloride fork, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, butadiene, propenylamine, Isobutenylamine, vinyl acetate, ethyl vinyl ether, methyl vinyl ketone, triallyl isocyanate, and the like.

< Styrene copolymer >

In the rubber-modified styrene-based resin of the present embodiment, the styrene-based copolymer can be obtained by polymerizing a styrene-based monomer and an acrylonitrile-based monomer, and optionally adding another copolymerizable monomer. The styrene-based copolymer may include 65% by weight to 78% by weight of styrene-based monomer units, 22% by weight to 35% by weight of acrylonitrile-based monomer units, and 0% by weight to 13% by weight of other The monomer unit can be copolymerized. Here, the monomer unit means a structural unit formed by copolymerization of a styrene monomer, an acrylonitrile monomer, or another copolymerizable monomer. The styrene-based copolymer is preferably a styrene-acrylonitrile-based copolymer.

In detail, in one embodiment, the preparation method of the styrene-acrylonitrile-based copolymer is not particularly limited, and may be a solution copolymerization method, a bulk copolymerization method, an emulsion copolymerization method, a suspension copolymerization method, or the like which is generally used. It is preferably a solution copolymerization method or a block copolymerization method. The reactor used in the foregoing reaction may be one of a fully mixed continuous reactor (CSTR), a column flow reactor (PFR), or a static mixing reactor or Different kinds of combinations. Taking the solution copolymerization method as an example, the production method of the styrene-acrylonitrile-based copolymer is obtained by solution copolymerization of a monomer component including a styrene monomer and an acrylonitrile monomer. However, the invention is not limited thereto. In another embodiment, the styrene-acrylonitrile-based copolymer may be prepared by a solution comprising a monomer component including a styrene monomer, an acrylonitrile monomer, and other copolymerizable monomers. It is obtained by polymerization.

The type of the styrene monomer is the same as the styrene monomer used in the rubber graft copolymer, and the styrene monomer may be used singly or in combination. Preferably, the styrene monomer is styrene. Α-methylstyrene, or a combination thereof. Further, the content of the styrene monomer may range from 50% by weight to 90% by weight based on 100% by weight of the total of the styrene monomer, the acrylonitrile monomer and the other copolymerizable monomer; preferably. It is from 55% by weight to 85% by weight; more preferably from 58% by weight to 80% by weight.

The type of the acrylonitrile-based monomer is the same as the acrylonitrile-based monomer used in the rubber graft copolymer, and the acrylonitrile-based monomer may be used singly or in combination. Preferably, the acrylonitrile-based monomer is acrylonitrile. Further, the content of the acrylic monomer may be from 10% by weight to 50% by weight based on 100% by weight based on the total amount of the styrene monomer, the acrylonitrile monomer and the other copolymerizable monomer; It is 15% by weight to 45% by weight; more preferably 20% by weight to 42% by weight.

Other kinds of copolymerizable monomers are like other copolymerizable monomers used in the foregoing rubber graft copolymer, and the other copolymerizable monomers may be used singly or in combination, preferably, the other copolymerizable singles The body is selected from methyl methacrylate, butyl methacrylate, monofunctional maleimide monomers, or a combination thereof. Further, the content of the other copolymerizable monomer may range from 0% by weight to 40% by weight based on 100% by weight of the total of the styrene monomer, the acrylonitrile monomer and the other copolymerizable monomer; It is preferably from 0% by weight to 30% by weight; more preferably from 0% by weight to 22% by weight.

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

Further, in the solution copolymerization reaction, a polymerization initiator may be optionally added. The polymerization initiator may be used in an amount of from 0 to 1 part by weight, preferably from 0.001 to 0.5 part by weight, based on 100 parts by total of the total amount of the reactant.

In detail, the polymerization initiator includes a monofunctional polymerization initiator, a polyfunctional polymerization initiator, or a combination thereof. The monofunctional polymerization initiators may be used singly or in combination, and the monofunctional polymerization initiators include, but are not limited to, benzoyl peroxide, dicumyl peroxide, peroxidation. T-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxybenzoate (t- Butyl-peroxy benzoate, bis-2-ethylhexyl peroxy dicarbonate, tert-butyl peroxy isopropyl carbonate (BPIC) , cyclohexanone peroxide, 2,2'-azo-bis-isobutyronitrile (AIBN), 1,1'-azobiscyclohexane 1-,1'-azo-biscyclohexane-1-carbonitrile, or 2,2'-azo-bis-2-methylbutyronitrile (2,2'-azo-bis-2-methyl) Butyronitrile), wherein benzammonium peroxide and 2,2'-azo-bis-isobutyronitrile are preferred.

The polyfunctional polymerization initiators may be used singly or in combination, and the polyfunctional polymerization initiators include, but are 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, referred to 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-per-butyl-perperoxyazelate, 2 ,5-Dimethyl-2,5-bis(benzoyl peroxy)hexane, di-tertiary butyl peroxidation -di-t-butyl peroxy-hexahydro-terephthalate (BPHTH), or 2,2-bis(4,4-di-t-butylperoxy)cyclohexylpropane (2) ,2-bis-(4,4-di-t-butyl peroxy)c Yclohexyl propane, referred to as PX-12).

Further, in the solution copolymerization reaction, a chain transfer agent may be selectively added. The chain transfer agent may be used singly or in combination, and the chain transfer agent includes, but is not limited to: (1) a mercaptan compound: methyl mercaptan, n-butyl mercaptan, cyclohexyl mercaptan, n- thirteen N-dodecyl mercaptan (NDM), stearyl mercaptan, t-dodecyl mercaptan (TDM), n-propyl mercaptan , n-octyl mercaptan, tri-octyl mercaptan, tri-decyl mercaptan, pentaerythritol tetrakis (3-mercapto propionate), isova Pentaerythritol tetrakis (2-mercapto ethanate), pentaerythritol tetrakis (4-mercapto butanate), pentaerythritol Pentaerythritol tetrakis (5-mercapto pentanate), pentaerythritol tetrakis (6-mercapto hexanate), tri-(2- Trimethylolpropane tris (2-mercapto ethanate), tris-(3-mercaptopropionic acid) trimethylolpropyl ester (trime) Thylolpropane tris (3-mercapto propionate), referred to as TMPT), or trimethylol-propane tris (6-mercapto hexanate), etc.; (2) alkylamine (alkyl) Amines) compounds: monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, monobutylamine, di-n-butylamine, or tri-n-butylamine, etc. (3) Other chain transfer agents: pentaphenylethane, α-methyl styrene dimer or terpinolene. Preferably, the chain transfer agent is selected from n-dodecyl mercaptan, tertiary dodecyl mercaptan, tris-(3-mercaptopropionic acid) trimethylol propyl ester, or the like combination. Further, the chain transfer agent may be 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 amount of the reactants.

Further, the operating temperature range of the solution copolymerization is, for example, 70 ° C to 140 ° C, preferably 90 ° C to 130 ° C.

A molded article according to another embodiment of the present invention is formed of the thermoplastic resin composition as described above. The preparation method of the molded article is not particularly limited, and thermoforming, vacuum forming, or a combination of the above processes may be employed. The thermoforming and vacuum forming can be carried out in a known manner and will not be described again.

The thermoplastic resin composition of the present invention will be more specifically described below with reference to several experiments. Although the following experiments are described, the materials used, the amounts and ratios thereof, the processing details, the processing flow, and the like can be appropriately changed without departing from the scope of the invention. Therefore, the invention should not be construed restrictively based on the experiments described below.

The average radius of gyration and the weight average molecular weight of each component obtained by the following experiment were determined as follows:

<average radius of gyration>

Multi-angle laser light scattering instrument (multi-angle) of DAWN8 ⁺ manufactured by Wyatt Technology Co., Ltd. using Gel Permeation Chromatography (GPC) manufactured by Waters Co., Ltd. Laser light scattering,MALLS) and Viscostar-II viscometer to determine the average radius of gyration [R(avg)], the analysis conditions are: MZ-Gel SDplus linear 5μm, 300mm × 8.0mm, mobile phase: THF (flow rate 0.5 ml/min).

<weight average molecular weight>

Gel Permeation Chromatography (GPC) manufactured by Waters Co., Ltd., with differential refractive index detector (Waters RI-2414) and ultraviolet visible light detector (Waters PDA-2996) The measurement conditions were as follows: column: MZ-Gel SDplus linear 5 μm, 300 mm × 8.0 mm, mobile phase: THF (flow rate 0.5 ml/min).

Each of the components used in the experimental examples and comparative examples was prepared as follows:

Synthesis of divergent copolymer

< Divided copolymer (BHAS-1)>

In the reactor, 0.3 parts by weight of tetrakis(3-mercaptopropionic acid) pentaerythritol, 71 parts by weight of styrene monomer, 29 parts by weight of acrylonitrile monomer, 150 parts by weight of deionized water, and 0.4 parts by weight of Calcium phosphate, 0.03 parts by weight of a carboxyl anionic surfactant, 0.01 parts by weight of a polyoxyethylene alkyl phosphate, and 0.001 parts by weight of a 2,2'-azobisisobutyronitrile starter are mixed and added to one In the reactor. The reactor was completely sealed. The mixture was thoroughly stirred to disperse. Heating was carried out to raise the reaction temperature to 75 ° C and the polymerization was carried out for 3 hours. After the end of the polymerization, the reactor was cooled to room temperature to terminate the reaction. The obtained product was washed, dehydrated and dried to obtain a divergent copolymer (BHAS-1) having a weight average molecular weight of 3.57 million and an average radius of gyration [R (avg)] of 80.7 nm.

< Divided copolymer (BHAS-2)>

The method for producing the divalent copolymer (BHAS-1) differs in that 0.6 parts by weight of pentaerythritol tetrakis(3-mercaptopropionic acid) is used to prepare a bifurcated copolymer (BHAS-2) having a weight average molecular weight of 3.02 million. The average radius of gyration [R(avg)] was 94.6 nm.

Linear copolymer (AS-869G)

A linear acrylonitrile-styrene (Linear AN-SM) copolymer (manufactured by Toray Industries, Inc., trade name AS-869G) having a weight average molecular weight of 2.75 million and an average radius of gyration [R(avg)] of 120.6 nm.

Rubber graft copolymer (BP-1) Preparation

150.00 parts by weight of 1,3-butadiene, 15.00 parts by weight of potassium persulfate solution (concentration 1 wt%), 2.00 parts by weight of potassium oleate, 0.13 parts by weight of ethylene glycol dimethacrylate and 190.00 The parts by weight of distilled water was reacted at a reaction temperature of 65 ° C for 14 hours to obtain a rubber emulsion having a weight average particle diameter of 0.1 μm (conversion ratio of about 94%, solid content of about 36%).

90.00 parts by weight of n-butyl acrylate, 10.00 parts by weight of methacrylic acid, 0.50 parts by weight of potassium persulfate solution (concentration: 1 wt%), 0.50 parts by weight of sodium lauryl sulfate solution (concentration: 10 wt%) 1.00 parts by weight of n-dodecyl mercaptan and 200.00 parts by weight of distilled water were reacted at a reaction temperature of 75 ° C for 5 hours to obtain a carboxylic acid group-containing polymer flocculant emulsion having a conversion of about 95% and a pH of 6.0. .

Thereafter, 3 parts by weight (dry weight) of a carboxylic acid group-containing polymer aggregating agent is used to ferment 100 parts by weight of the rubber latex, and the obtained rubber emulsion has a pH of 8.5 and a rubber weight average particle diameter of about 0.3. Mm.

Further, 300.0 parts by weight of the above-mentioned enlarged rubber emulsion (dry weight), 75.0 parts by weight of styrene, 25.0 parts by weight of acrylonitrile, 2.0 parts by weight of thirteen-dodecyl mercaptan, and 3.0 parts by weight of isopropyl Benzene hydroperoxide, 3.0 parts by weight of ferrous sulfate solution (concentration 0.2 wt%), 0.9 parts by weight of sodium formaldehyde sulfoxylate solution (concentration: 10 wt%), and 3.0 parts by weight of ethylenediaminetetraacetic acid solution (concentration 0.25) Gt%), the above-mentioned hypertrophized rubber emulsion is graft-polymerized with a styrene acrylonitrile copolymer to produce a rubber graft copolymer. The prepared rubber graft copolymer emulsion is coagulated with calcium chloride, and then dehydrated and dried to less than 2% to obtain a desired rubber graft copolymer (BP-1), and the average weight of the rubber particles is The particle size was 0.31 μm and the rubber content was 75% by weight.

Rubber graft copolymer (BP-2) Preparation

6.6 parts by weight of polybutadiene (available from Asahi Kasei Co., Ltd. under the trade name Asadene 55AS) was completely dissolved in 74.4 parts by weight of styrene and 25.6 parts by weight of propylene with 0.08 parts by weight of benzamidine peroxide as a starting agent. Nitrile and 30 parts by weight of ethylbenzene to form a feed solution, and then the feed solution is continuously fed into a first reactor having a volume of 45 liters, the reaction temperature is 100 ° C, and a cooling circulation tube is disposed in the reactor. The spiral agitator has a stirring rate of 150 rpm, a monomer conversion rate of 15% in the first reactor, and the mixture after the first reactor reaction is continuously taken out and sequentially sent to the second, third, and fourth reactions. In the third reactor, 0.1 part by weight of a third-dodecyl mercaptan is simultaneously added, and the reverse phenomenon is generated in the second reactor, and the second, third and fourth reactors are first and the first The reactor is the same, but the reaction temperature is 105 ° C, 110 ° C, 125 ° C, and the stirring rate is 270 rpm, 150 rpm and 110 rpm. When the conversion ratio of the hydrazine mixture reaches 60%, the mixture is taken out and sent to the devolatilizer. Remove unreacted monomer Volatiles, after which extrusion granulation, can be prepared of the granulated rubber graft copolymer (BP-2), rubber particles of weight average particle diameter of 0.95 m, the rubber content of 10 wt%.

Preparation of styrene copolymer

68 parts by weight of styrene, 32 parts by weight of acrylonitrile, and 8 parts by weight of ethylbenzene were mixed, and then mixed with 0.01 part by weight of the third-dodecyl mercaptan, and at a flow rate of 35 kg/hr. The mixture was continuously fed to a fully mixed continuous reactor having a volume of 40 liters, an internal temperature of 145 ° C, a pressure of 4 kg/cm ² and an overall conversion of about 55%.

After the completion of the polymerization, the obtained copolymer solution was heated by a preheater, and volatile substances such as unreacted monomers and solvents were removed in a vacuum degassing tank. Next, the obtained polymer melt is subjected to granulation to obtain a styrene-acrylonitrile copolymer (AS) having a weight average molecular weight of 210,000 and a styrene monomer unit content of 72% and an acrylonitrile monomer unit content. It is 28%.

Preparation of thermoplastic resin composition

In a dry state, based on 100 parts by weight of the rubber-modified styrene resin (BP-1, BP-2 and AS), 15.20 parts by weight of a rubber graft copolymer (BP-1), 6.08 by weight A portion of the rubber graft copolymer (BP-2) and 78.72 parts by weight of the styrene-acrylonitrile copolymer (AS) are added to a two-axis extruder (Model: ZPT-25, manufacturer: Zeji Industry Co., Ltd.) And adding a ratio of a pair of divergent copolymer (BHAS-1), a divergent copolymer (BHAS-2), and a linear copolymer (AS-869G) according to the table, and adding 2.00 parts by weight of a lubricant to 220°. The thermoplastic resin composition of Experimental Example 1 to Experimental Example 8, Comparative Example 1 and Comparative Example 2 was obtained by kneading at a kneading temperature of C and then extruding it by a biaxial extruder.

The elongational viscosity and shear viscosity of each of the thermoplastic resin compositions prepared in the above experiment were measured by the following measurement methods, and the results are shown in Table 1.

<Elongation viscosity>

A rheometer (Rheometer ARES-G2) manufactured by TA Instruments was used at a temperature of 170 ° C and a shear rate of 0.5 / s.

<Shear viscosity>

A rheometer (Rheometer ARES-G2) manufactured by TA Instruments was used at a temperature of 230 ° C and a shear rate of 100 / s.

Table I BP-1: rubber graft copolymer BP-2: rubber graft copolymer AS: styrene-acrylonitrile copolymer BHAS-1: divergent copolymer BHAS-2: divergent copolymer AS-869G: linear copolymerization Object

Table 1 (continued)

In the results of Table 1, the divergent copolymer (BHAS-1) and the divergent copolymer (BHAS-2) were exemplarily used for comparison with the linear copolymer (AS-869G), but this should not be used. Limit the invention.

First, please refer to Experimental Examples 1, 3 and Comparative Examples 1 and 2 of Table 1, which are respectively containing 2 parts by weight of a branched copolymer (BHAS-1) and 2 parts by weight of a divalent copolymer (BHAS-2). 2 parts by weight of a linear copolymer (AS-869G) and a thermoplastic resin composition without adding a bifurcated copolymer or a linear copolymer; wherein Comparative Example 2 was prepared without adding any divergent copolymer or linear copolymer The thermoplastic resin composition has a high shear viscosity (1703 Pa*sec) and is not easy to perform sheet metal working, and its elongational viscosity (685312 Pa*sec) is also low, which is disadvantageous for vacuum forming. Although in Comparative Example 1, 2 parts by weight of a linear copolymer (AS-869G) was added so that the thermoplastic resin composition had a high elongational viscosity (821718 Pa*sec), its shear viscosity (1739 Pa*) Sec) did not achieve significant improvement.

On the other hand, in the thermoplastic resin compositions of Experimental Examples 1 and 3, the same weight parts (2 parts by weight) of the branched copolymer (BHAS-1) and the branched copolymer (BHAS-2) were respectively added, and the elongational viscosity was not only large. As a result, the shear viscosity was also significantly lowered, so the thermoplastic resin compositions of Experimental Examples 1 and 3 had better sheeting and vacuum formability.

From the test results of Experimental Example 1 to Experimental Example 4, it is understood that regardless of the use of 2 parts by weight or 3 parts by weight of the condensed copolymer, the divergent copolymer contains a tetrathiol compound unit and the obtained bifurcated copolymer The weight average molecular weight is from 1,000,000 to 7 million, so the elongational viscosity measured in Experimental Example 1 to Experimental Example 4 is higher than that of Comparative Example 1 or 2, and is measured in Experimental Example 1 to Experimental Example 4. The shear viscosity is not more than 1673 Pa*sec, which means that it is easy to be formed by a plate press, which is suitable for vacuum forming applications.

In addition, from the measurement results of Experimental Examples 1, 2, and 5-8, it is known that the more the content of the branched copolymer added, the greater the elongation viscosity, and the shear viscosity also increases, especially the divergent copolymer exceeds 4 In the case of parts by weight, Experimental Example 6 was exemplified (containing 6 parts by weight of a divalent copolymer), and the elongational viscosity of Experimental Example 6 exceeded 1,200,000 Pa*sec, and the shear viscosity (1799 Pa*sec) was slightly higher than that of Comparative Example 1. Shear viscosity (1739 Pa*sec), so that the appropriate amount of the copolymer can be added to the thermoplastic resin composition according to the processing requirements, and subsequent processing is easy.

In summary, the thermoplastic resin composition of the present invention comprises a rubber-modified styrene resin and a condensed copolymer having a weight average molecular weight of 1,000,000 to 7,000,000 and comprising a tetrathiol. a compound unit, a styrene monomer unit, and an acrylonitrile monomer unit. The thermoplastic resin composition of the present invention imparts a good shear viscosity and an excellent elongational viscosity by the above-mentioned dike-like copolymer, so that the sheeting property and vacuum moldability required for processing (particularly, vacuum molding) can be maintained.

While the present invention has been described above by way of example, it is not intended to limit the scope of the present invention, and it is possible to make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

Claims (13)

A thermoplastic resin composition comprising: a rubber modified styrene resin; and a divergent copolymer having a weight average molecular weight of 1,000,000 to 7 million, the divergent copolymer comprising a tetrathiol compound unit, a styrene series Body unit and acrylonitrile monomer unit. The thermoplastic resin composition according to claim 1, wherein the divergent copolymer has an average radius of gyration of from 75 nm to 110 nm. The thermoplastic resin composition according to claim 1, wherein the divalent copolymer has a weight average molecular weight of 2,000,000 to 5,000,000. The thermoplastic resin composition according to claim 1, wherein the content of the conjugated copolymer is from 1 part by weight to 10 parts by weight based on 100 parts by weight of the rubber-modified styrene resin. The thermoplastic resin composition according to claim 4, wherein the content of the conjugated copolymer is from 1 part by weight to 8 parts by weight based on 100 parts by weight of the rubber-modified styrene resin. The thermoplastic resin composition according to claim 5, wherein the content of the conjugated copolymer is from 1.5 parts by weight to 6 parts by weight based on 100 parts by weight of the rubber-modified styrene resin. The thermoplastic resin composition according to claim 6, wherein the content of the conjugated copolymer is from 2 parts by weight to 4 parts by weight based on 100 parts by weight of the rubber-modified styrene resin. The thermoplastic resin composition according to claim 1, wherein the tetrathiol compound unit is formed of a tetrathiol compound. The thermoplastic resin composition according to claim 8, wherein the tetrathiol compound is selected from the group consisting of pentaerythritol tetrakis (3-mercapto propionate) and tetrakis (2-mercapto). Pentaerythritol tetrakis (2-mercapto ethanate), pentaerythritol tetrakis (4-mercapto butanate), tetrakis(5-mercaptovaleric acid) pentaerythritol [pentaerythritol tetrakis (5) -mercapto pentanate)] and at least one of the group consisting of pentaerythritol tetrakis (6-mercapto hexanate). The thermoplastic resin composition according to claim 9, wherein the tetrathiol compound is pentaerythritol tetrakis (3-mercapto propionate). The thermoplastic resin composition according to claim 1, wherein the styrene monomer unit is a styrene monomer unit. The thermoplastic resin composition according to claim 1, wherein the acrylonitrile monomer unit is an acrylonitrile monomer unit. A molded article is formed from the thermoplastic resin composition according to any one of claims 1 to 12.