TWI432461B - Styrene-based resin composition, method for preparing the same and products made therefrom - Google Patents

Description

Styrene resin composition, preparation method thereof and molded article obtained therefrom

The present invention relates to a styrene resin, and more particularly to a styrene resin composition comprising a copolymer and rubber particles coated with a styrene copolymer.

Generally, styrene-based resins with high impact resistance are well evaluated for their formability and mechanical properties, and the molded articles formed therefrom have good appearance and gloss, and are then widely used in electronics and electrical appliances. Supplies and car parts. However, for styrene-based resins having high impact resistance, in order to be applied to a wider range of fields, glossiness and impact resistance are often required.

Generally, a styrene resin having high impact resistance is composed of rubber particles and a styrene main body, and the rubber particles can be classified into rubber particles coated with a styrene copolymer and rubber particles not coated with a styrene copolymer. Among them, in the styrene resin containing the rubber particles not coated with the styrene copolymer, the weight average particle diameter of the rubber particles is small, so that the styrene resin has characteristics of high glossiness and high impact resistance. In the styrene resin containing the rubber particles coated with the styrene copolymer, the weight average particle diameter of the rubber particles is large and the particle size distribution is uneven, so that the gloss and impact resistance of the styrene resin are not good, and the styrene resin cannot be used. Meet the needs of users.

Furthermore, at present, styrene resins containing rubber particles which are not coated with a styrene copolymer are mostly used in an emulsion polymerization manner, but the emulsion polymerization method may cause a problem of waste water waste liquid, which does not meet the economic benefits of the industry, and thus in recent years, In order to meet the requirements of environmental protection, the method for preparing a styrene resin having high impact resistance is changed from an emulsion polymerization method to a bulk polymerization method or a solution polymerization method, but the overall polymerization method or solution polymerization method is used. The obtained styrene-based resin is the above-mentioned styrene resin containing rubber particles coated with a styrene copolymer, and does not meet the needs of the product of the manufacturer.

Therefore, how to develop a styrene-based resin having high gloss and impact resistance under the consideration of environmentally-friendly processes has become an urgent problem to be solved by those skilled in the art.

Accordingly, a first object of the present invention is to provide a process for preparing a styrene resin composition.

Thus, the method for preparing a styrene resin composition of the present invention comprises the steps of: subjecting a first starting material to a continuous solution polymerization to form a first reaction mixture, wherein the first starting material comprises a rubber component, The monomer component and the solvent include a styrene monomer, and the rubber component comprises a first rubber component and a second rubber component; and a second starting material is subjected to continuous solution polymerization to form a second a reaction mixture, wherein the second starting material comprises a monomer component comprising a styrenic monomer and a solvent; then, the first reaction mixture is mixed with the second reaction mixture, and continuous solution polymerization is carried out, ie This styrene resin composition can be obtained.

A second object of the present invention is to provide a styrene resin composition.

Thus, the styrene resin composition of the present invention is obtained by the method as described above.

In particular, the inventors of the present invention actively researched and developed different styrenic resin compositions by the above-mentioned preparation methods, which contribute to the improvement of the gloss and impact resistance of the styrene resin composition, and can satisfy the industry for benzene. The demand for a vinyl resin composition.

Accordingly, a third object of the present invention is to provide a styrene resin composition having better gloss and impact resistance, comprising: a copolymer as a continuous phase, the copolymer comprising a styrene monomer unit And rubber particles coated with a styrene-based copolymer as a dispersed phase; in the rubber particles coated with the styrene-based copolymer, n rubbers coated with a styrene-based copolymer having a particle diameter of more than 0.4 μm are collected Particles, and calculate the central value B and the average value C by the following two formulas: the central value , Ai represents the particle diameter difference between the styrene copolymer having the largest particle diameter and the styrene copolymer having the smallest particle diameter in the rubber particles coated with the styrene copolymer having the i-th particle diameter of more than 0.4 μm; value Among them, the range of C/B is less than 15%.

A fourth object of the present invention is to provide a molded article of a styrene resin composition.

Then, the molded article of the styrene resin composition of the present invention is formed of a styrene resin composition as described above.

The effect of the present invention is that the particle size of the styrene-based copolymer in the rubber particles coated with the styrene-based copolymer is adjusted so that the C/B range is less than 15%, and then the styrene-based resin composition has Better gloss and impact resistance.

<Preparation of styrene resin composition>

The method for preparing a styrene resin composition of the present invention comprises the steps of: subjecting a first starting material to a continuous solution polymerization to form a first reaction mixture, wherein the first starting material comprises a rubber component, including benzene a monomer component and a solvent of the vinyl monomer, and the rubber component comprises a first rubber component and a second rubber component; and a second starting material is subjected to continuous solution polymerization to form a second reaction mixture Wherein the second starting material comprises a monomer component comprising a styrenic monomer and a solvent; and then, the first reaction mixture is mixed with the second reaction mixture and subjected to continuous solution polymerization to obtain The styrene resin composition.

The reactor for carrying out the continuous solution polymerization reaction includes, but is not limited to, a plug flow reactor (PFR), a continuous stirred-tank reactor (CSTR), or a static type mixing. Reactor (Static reactor) and the like. The number of the reactors may be two or more, preferably three or more. When several reactors are used, the reactors may be connected in series or in parallel, wherein one reactor is arranged in parallel with the other reactors. These reactors are preferably columnar flow reactors.

Preferably, the reactor for performing the continuous solution polymerization comprises a first reactor R1 and a second reactor R2 connected in series, and a sixth reactor having an outlet in parallel with the first reactor R1. R6, the outlet of the sixth reactor R6 is connected to the second reactor R2. The reaction temperature of the reactors is not particularly limited, and is determined depending on the solid content of each reactor at the time of polymerization. The reaction temperatures of the reactors range from 70 °C to 230 °C.

In detail, in the step of the continuous solution polymerization reaction, the first starting material is continuously introduced into the first reactor R1 for polymerization, and after the polymerization reaction, a first reaction mixture is formed and introduced into the second reactor. R2; the second starting material is continuously introduced into the sixth reactor R6, after the polymerization reaction, a second reaction mixture is formed, and introduced into the second reactor R2, and mixed with the first reaction mixture, and The second reactor R2 produces a reverse rotation phenomenon. Optionally, it is further reacted in the second reactor R2 to form a third reaction mixture, which is then introduced into the third reactor R3, the fourth reactor R4 and the fifth reactor R5 to carry out a polymerization reaction.

In a specific example of the present invention, the reactor for performing the continuous solution polymerization reaction comprises a first reactor R1, a second reactor R2, a third reactor R3, a fourth reactor R4, and a fifth reaction which are sequentially connected in series. R5, and a sixth reactor R6 connected in parallel with the first reactor R1 and having an outlet, the outlet of the sixth reactor R6 being connected to the second reactor R2.

After the polymerization reaction in the reactor reaches the desired conversion rate, the solution after the reaction is continuously taken out from the reaction system, and further introduced into a devolatilization device, by which the devolatilization device will be unreacted. The styrene resin composition of the present invention can be obtained by removing the starting material and the volatile component generated after the reaction, or further granulating.

In general, the devolatilizer can use a vacuum degassing tank device or a degasser. The unreacted starting material or volatile component removed by the devolatilizer is optionally recovered by a condenser, and if necessary, the water in the recovered liquid can be removed and used as a starting material. The devolatilizer may be, for example, a uniaxially attached devolatilizing extruder, a biaxial venting extruder, a thin film, or a devolatilization tank with a vacuuming device. In the devolatilization process, a devolatilization aid may be added to the extruder as needed. The devolatilization aid includes, but is not limited to, water, cyclohexane, carbon dioxide, and the like. The devolatilizer may also be provided with a kneading zone or a pumping zone as needed, and the screw rotation speed ranges from 120 rpm to 350 rpm. For the purposes of the present invention, the devolatilizer is preferably a two-axis extruder with a devolatilization port. The devolatilizer may be used in series or in plurality, and the temperature thereof is controlled at 180 ° C to 350 ° C, preferably 200 ° C to 320 ° C, more preferably 220 ° C to 300 ° C, and the vacuum of the devolatilizer is controlled at 300 Torr or less, preferably 200 Torr or less, more preferably 100 Torr or less.

The first starting material comprises 5% by weight to 20% by weight of the rubber component, 55% by weight to 90% by weight of the monomer component including the styrene monomer, and 5% by weight to 25% by weight of the solvent; The second starting material comprises from 75% by weight to 99% by weight and comprises a monomer component of a styrene monomer, and a solvent of from 1% by weight to 25% by weight. In the continuous solution polymerization, a polymerization initiator, a chain transfer agent or the like may be optionally added to the first starting material or the second starting material.

The rubber component includes, but is not limited to, a diene rubber, a polyolefin rubber, a polyacrylate rubber, or a polyoxyalkylene rubber. The polyolefin rubber includes, but is not limited to, an ethylene-propylene rubber. Preferably, the rubber component is a diene rubber. Preferably, the diene rubber is obtained by polymerizing a diene monomer (or a diene monomer and another monomer), and has a glass transition temperature of 0 ° C or lower. The diene monomer may be used singly or in combination, and the diene monomer includes, but is not limited to, 1,3-butadiene, methyl-1,3-butadiene, 2,3-dimethyl- 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, chloroprene, and the like. Preferably, the diene monomer is selected from the group consisting of 1,3-butadiene, 2-methyl-1,3-butadiene, 1,3-pentadiene, chloroprene, or the like. Wait for a combination.

The diene rubber includes, but is not limited to, butadiene rubber, isoprene rubber, chloroprene rubber, ethylene propylene diene terpolymer (EPDM), styrene. - a diene rubber, an acrylonitrile-diene rubber, or the like. The butadiene rubber includes, but is not limited to, a high cis (Hi-Cis) content of butadiene rubber and a low cis (Low-Cis) content of butadiene rubber. The typical weight composition of cis (Cis)/vinyl (Vinyl) in the high cis content butadiene rubber is (94 to 99 wt%) / (0 to 5 wt%), and the rest of the composition is trans. (Trans) structure, and Mooney viscosity is between 20 and 120, and the molecular weight range is preferably from 100,000 to 800,000. The typical weight composition of cis/vinyl in the low cis content butadiene rubber ranges from (20 to 40 wt%) / (6 to 20 wt%), the balance is trans structure, and the Mooney viscosity is From 20 to 120, the molecular weight range is preferably from 100,000 to 800,000.

The styrene-diene rubber includes, but is not limited to, styrene-butadiene rubber, styrene-isoprene rubber, and the like. The styrene-diene rubber has a Mooney viscosity of 20 to 80 and a solution viscosity of 3 cps to 200 cps (measured by a 5% by weight styrene solution at 25 ° C), wherein the styrene-diene system The content of the 1,2-vinyl (1,2-vinyl) monomer unit in the rubber is in the range of 8 to 40% by weight, and the total amount of the styrene-diene rubber is 100% by weight, the styrene The content of the monomer unit ranges from 5% by weight to 35% by weight, and the weight average molecular weight of the styrene-diene rubber ranges from 50,000 to 800,000.

The structure of the diene rubber may be a homopolymer block structure, a random structure, a tapered or tapered structure, a linear structure, a divergent structure, or the like. Mixed structure. For example, the styrene-diene rubber of the homopolymer block construction includes, but is not limited to, a styrene-butadiene-styrene block (S-B-S). The randomly constructed styrene-diene rubber includes, but is not limited to, styrene-random styrene/butadiene-styrene block (S-random S/BS), random styrene/butadiene embedded Section (random S/B), butadiene-random styrene/butadiene-butadiene block (B-random S/BB), butadiene-random styrene/butadiene block ( B-random S/B). The styrene-diene rubber having an increasing or decreasing structure includes, but is not limited to, styrene-increasing or decreasing styrene/butadiene-styrene block (S-taper S/BS), butadiene - Composition of increasing or decreasing styrene/butadiene-styrene blocks (B-taper S/BS).

The styrene monomer may be used singly or in combination, and the styrene monomer includes, but not limited to, styrene, α-methyl styrene, p-methyl styrene, m-methyl styrene, ortho-A. Styrene, ethyl styrene, 2,4-dimethyl styrene, p-tert-butyl styrene, α-methyl-p-methyl styrene, bromine-styrene, dibromo-styrene , 2,4,6-tribromostyrene, and the like.

The monomer component further includes other copolymerizable monomers. Preferably, the monomer copolymer is used in an amount of 100% by weight based on the monomer component, and the other copolymerizable monomer is used in an amount ranging from 5% by weight to 50% by weight. %. The other copolymerizable monomers may be used singly or in combination, and the other copolymerizable monomers include, but are not limited to, ethylbenzene, acrylic monomers, methacrylic monomers, acrylate monomers, methacrylic acid. Ester monomer, maleic imine monomer, anhydrous maleic acid, cis-methylbutenedioic acid, anhydrous methyl fumarate (trans-methylbutenedioic) Acid), fumaric acid, itaconic acid, dimethylfumarate, dibutyl itaconate, and the like. The acrylic monomer includes, but is not limited to, acrylic acid or the like. The methacrylic monomer includes, but is not limited to, methacrylic acid or the like. The methacrylate monomer includes, but is not limited to, methyl methacrylate, ethyl methacrylate, and the like. The maleimide monomer includes, but is not limited to, maleic imine, nitrogen-methyl maleimide, nitrogen-isopropyl maleimide, nitrogen-butyl maleimide, Nitrogen-hexylmaleimide, nitrogen-octylmaleimide, nitrogen-dodecylmaleimide, nitrogen-cyclohexylmaleimide, nitrogen-phenylmaleimide , Bismaleimide monomer, and the like.

The solvent may be used singly or in combination, and the solvent includes, but is not limited to, (1) aromatic hydrocarbons: toluene, ethylbenzene, xylene, etc.; (2) aliphatic hydrocarbons: hexane, heptane, cyclohexane Alkane; (3) ketones: methyl ethyl ketone, acetone and methyl ketone; (4) esters.

In a specific example of the present invention, the rubber component comprises 80% by weight to 99% by weight of the first rubber component and 1% by weight to 20% by weight of the second rubber component.

Preferably, the first rubber component comprises 5% by weight to 20% by weight of a linear structure styrene-butadiene rubber and 80% by weight to 95% by weight of a bifurcated styrene-butadiene rubber; The rubber component includes 50% by weight to 70% by weight of a linear structure styrene-butadiene rubber and 30% by weight to 50% by weight of a bifurcated styrene-butadiene rubber.

The styrene-butadiene rubber in the first rubber component has a Mooney viscosity of 20 to 70 and a solution viscosity of 10 cps to 50 cps (measured by a 5% concentration of a styrene solution at 25 ° C), wherein The content of the 1,2-vinyl monomer unit in the styrene-butadiene rubber ranges from 8% by weight to 30% by weight, and the weight average molecular weight of the styrene-butadiene rubber ranges from 200,000 to 500,000.

The styrene-butadiene rubber in the second rubber component has a Mooney viscosity of 30 to 80, and a solution viscosity of 100 cps to 200 cps (measured by a 5% concentration of a styrene solution at 25 ° C), wherein The content of the 1,2-vinyl monomer unit in the styrene-butadiene rubber ranges from 8% by weight to 25% by weight, and the weight average molecular weight of the styrene-butadiene rubber ranges from 400,000 to 800,000.

The solid content of the first reaction mixture after the first starting material is reacted in the first reactor R1 ranges from 10% by weight to 30% by weight; preferably, the solid content ranges from 12% by weight to 25% by weight; more preferably The solids content ranges from 15% by weight to 20% by weight.

The solid content of the second reaction mixture after the second starting material is reacted in the sixth reactor R6 ranges from 30% by weight to 60% by weight; preferably, the solid content ranges from 40% by weight to 60% by weight; Preferably, the solids content ranges from 45% to 55% by weight.

The solid content of the third reaction mixture ranges from 20% by weight to 35% by weight; preferably, the solid content ranges from 23% by weight to 33% by weight; more preferably, the solid content ranges from 25% by weight to 32% by weight %.

After the fifth reactor R5 is mixed, the subsequent polymerization reaction is carried out, and the reaction mixture has a solid content ranging from 25% by weight to 55% by weight; preferably, the solid content ranges from 30% by weight to 50% by weight; More preferably, the solids content ranges from 35% to 45% by weight.

The polymerization initiator is selected from a monofunctional polymerization initiator, a polyfunctional polymerization initiator, or a combination thereof. The monofunctional polymerization initiator may be used singly or in combination, and the monofunctional polymerization initiator includes, but is not limited to, benzoyl peroxide, dicumyl peroxide, 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 (ANBN), 1,1'-azobicyclo 1,1'-azo-biscyclohexane-1-carbonitrile, 2,2'-azo-bis-2-methylbutyronitrile (2,2'-azo-bis-2- Methyl butyronitrile) and the like. Among them, benzammonium peroxide and diphenylisopropyl peroxide are preferred.

The polyfunctional polymerization initiator may be used singly or in combination, and the polyfunctional polymerization initiator includes, but is not limited to, 1,1-bis-tert-butylperoxycyclohexane (1,1-bis-t) -butyl peroxy cyclohexane (TX-22), 1,1-bis-tert-butylperoxide-3,3,5-trimethylcyclohexane (1,1-bis-t-butylperoxy-3,3 ,5-trimethyl cyclohexane, abbreviated as TX-29A), 2,5-dimethyl-2,5-bis-(2-ethylperoxyhexane)hexane [2,5-dimethyl-2,5-bis -(2-ethylhexanoxy peroxy)hexane], 4-(t-butylperoxycarbonyl)-3-hexyl-6-[7-(t-butylperoxycarbonyl)heptyl]cyclohexane {4-( T-butyl peroxy carbonyl)-3-hexyl-6-[7-(t-butyl peroxy carbonyl)heptyl] cyclohexane}, di-t-butyl-diperoxyazelate , 2,5-Dimethyl-2,5-bis(benzoquinone peroxy)hexane, 2,5-dimethyl-2,5-bis-(benzoyl peroxy)hexane, di-t-butyl Di-t-butyl peroxy-hexahydro-terephthalate (BPHTH), 2,2-bis(4,4-di-t-butylperoxy)cyclohexylpropane [ 2,2-bis-(4,4-di-t-butyl peroxy)cyclohexyl propane, abbreviated as P X-12], a polyfunctional monoperoxycarbonate (for example, manufactured by ATOFINA, USA, trade name Luperox JWE B-50). Preferably, the polymerization initiator is used in an amount ranging from 0 ppm to 10,000 ppm based on 100 parts by weight of the total amount of the starting materials; more preferably, the polymerization initiator is used in an amount ranging from 10 ppm to ～ 7,000 ppm.

The chain transfer agent is selected from a monofunctional chain transfer agent, a polyfunctional chain transfer agent, or a combination thereof. The monofunctional chain transfer agent may be used singly or in combination, and the monofunctional chain transfer agent includes, but is not limited to, (1) mercaptans: methyl mercaptan, n-butyl mercaptan, cyclohexyl sulfur Alcohol, n-dodecyl mercaptan (NDM), stearyl mercaptan, t-dodecyl mercaptan (TDM), N-propyl mercaptan, n-octyl mercaptan, tri-octyl mercaptan, tri-decyl mercaptan, etc.; (2) alkyl amines: monoethylamine, diethyl Amine, triethylamine, monoisopropylamine, diisopropylamine, monobutylamine, di-n-butylamine, tri-n-butylamine, etc.; (3) other; pentaphenylethane ( Penta phenylethane), α-methylstyrene dimer, terpinolene, and the like. Among them, n-dodecyl mercaptan and tert-dodecyl mercaptan are preferred.

The polyfunctional chain transfer agent may be used singly or in combination, and the polyfunctional chain transfer agent includes, but is not limited to, pentaerythritol thirrol tetrakis (3-mercapto propionate), Pentaerythritol tetrakis (2-mercapto acetate), trimethylolpropane tris (2-mercapto acetate), three -(3-mercaptopropionic acid) trimethylolpropane tris (3-mercapto propionate), abbreviated as TMPT], tris-(6-mercaptohexanoic acid) trimethylolpropyl ester [trimethylol-propane tris (6 -mercapto hexanate)] and so on. Among them, tris-(3-mercaptopropionic acid) trimethylolpropyl ester is preferred. Preferably, the chain transfer agent is used in an amount ranging from 0 ppm to 10,000 ppm based on 100 parts by weight of the total amount of the starting materials; more preferably, the chain transfer agent is used in an amount ranging from 10 ppm to 7,000 ppm. .

In the range in which the effect of the styrene resin composition of the present invention is not impaired, various additives may be added as necessary in the preparation of the styrene resin composition of the present invention. The additive may be used singly or in combination, and the additive is selected from the group consisting of an antioxidant, a conductive agent, a charge inhibitor, a plasticizer, a filler, a colorant, a lubricant, a charge inhibitor, a flame retardant, and a flame retardant. A light stabilizer, a thermal stabilizer, a release agent, a tackifier, a coupling agent, or a combination thereof. The above additives may be added in the above continuous solution polymerization reaction or after the polymerization reaction, respectively. The above additives may, for example, be mineral oil, an ester-based plasticizer of butyl stearate, a polyester-based plasticizer, an organopolyoxane of polydimethyloxane, a higher fatty acid and a metal salt thereof, and a hindered amine-based antibody. Hindered amine, glass fiber, etc. The polyester-based plasticizer or mineral oil is used in an amount ranging from 0 part by weight to 5 parts by weight per 100 parts by weight based on the total amount of the styrene resin composition. Preferably, the polyester-based plasticizer or mineral oil is used in an amount ranging from 0.05 part by weight to 2 parts by weight, respectively. The organopolysiloxane is used in an amount ranging from 0 parts by weight to 0.5 parts by weight based on 100 parts by weight of the total amount of the styrene resin composition. Preferably, the organopolyoxane is used in an amount ranging from 0.002 parts by weight to 0.2 parts by weight.

In the range in which the effect of the styrene resin composition of the present invention is not impaired, various polymers may be mixed as necessary in the preparation of the styrene resin composition of the present invention. The polymer may be used singly or in combination, and the polymer includes, but is not limited to, a styrene-(meth)acrylate-acrylonitrile copolymer, a styrene-(meth)acrylate copolymer, and benzene. Ethylene-(meth)acrylate-acrylonitrile-maleimide copolymer, styrene-(meth)acrylate-maleimide copolymer, (meth)acrylic acid An ester-maleimide copolymer or a copolymer of the diene rubber modified (or graft modified). The polymer is used in an amount of 200 parts by weight or less based on 100 parts by weight of the total of the styrene resin composition. It can adjust or improve the heat resistance, rigidity or flow processability of the styrene resin composition.

The styrene resin composition of the present invention is obtained by the method as described above.

In particular, the inventors of the present invention actively studied and developed different styrenic resin compositions by the above-mentioned preparation methods, which contribute to the improvement of the glossiness and impact resistance of the styrene resin composition, and can satisfy the industry's The demand for a styrene resin composition.

<Styrene resin composition>

The rubber particles coated with the styrene copolymer in the styrene resin composition include one or several styrene copolymers, a rubber body coated with a styrene copolymer, and a graft onto the rubber body. Graft copolymer. The styrene-based copolymer and the graft copolymer are each formed by polymerization of a monomer component including a styrene-based monomer. The rubber system is formed from a rubber component. The rubber particles coated with the styrene-based copolymer have a bimodal distribution, and the weight average particle diameter ranges from 0.4 μm to 1.2 μm, and the other weight average particle diameter ranges from 4 μm to 9 μm.

The styrene resin composition of the present invention comprises a copolymer as a continuous phase, the copolymer comprising a styrene monomer unit; and a rubber particle coated with a styrene copolymer as a dispersed phase; In the rubber particles of the ethylene-based copolymer, n rubber particles coated with a styrene-based copolymer having a particle diameter of more than 0.4 μm were collected, and the central value B and the average value C were calculated by the following two formulas: the central value , Ai represents the particle diameter difference between the styrene copolymer having the largest particle diameter and the styrene copolymer having the smallest particle diameter in the rubber particles coated with the styrene copolymer having the i-th particle diameter of more than 0.4 μm; value Among them, the range of C/B is less than 15%.

When the range of the C/B is 15% or more, it means that the styrene copolymer having a larger particle diameter and the styrene copolymer having a smaller particle diameter in each rubber particle coated with the styrene copolymer are more. That is, the uniformity of the particle diameter of the styrene-based copolymer is not good, and the uneven particle size of the styrene-based copolymer makes the gloss and impact resistance of the styrene-based resin composition unsatisfactory. When the range of C/B is less than 15%, it means that the larger particle size styrene copolymer and the smaller particle size styrene copolymer in each of the rubber particles coated with the styrene copolymer are less. That is, the styrene-based copolymer has a relatively uniform particle size, and the styrene-based resin composition has better gloss and impact resistance. Preferably, the C/B range is less than 13%. More preferably, the C/B range is less than 11%.

In the method for measuring rubber particles coated with a styrene-based copolymer having a particle diameter of more than 0.4 μm in the styrene resin composition of the present invention, the styrene resin composition is dyed with osmium tetroxide (OsO ₄ ), and then The coated styrene-based copolymer having a particle size of more than 0.4 μm can be obtained by photographing through a transmission electron microscope and magnifying 25,000 times of the rubber particles coated with the styrene-based copolymer photographed in the photograph. Rubber particles of matter. The method for measuring the difference in particle size Ai between the styrene copolymer having a larger particle diameter and the styrene copolymer having a smaller particle diameter in the rubber particles coated with the styrene copolymer is to use the above 25,000 magnification photo. The image processing technique obtained an image of the styrene copolymer, and the particle size of the styrene copolymer was measured by Soft Imaging System's Analyse SIS software.

The larger the central value B or the average value C, the more uneven the particle size of the styrene-based copolymer in the rubber particles coated with the styrene-based copolymer, and the smaller the central value B or the average value C indicates the package. The particle size of the styrene-based copolymer in the rubber particles coated with the styrene-based copolymer is more uniform. In order to make the styrene resin composition have better gloss and impact resistance, the center value B preferably ranges from less than 0.29 μm; more preferably, the center value B ranges from less than 0.28 μm.

The ratio of the central value B and the average value C of the styrene resin composition of the present invention to the central value B can be achieved by the arrangement of a plurality of reactors during polymerization, the reactor stirring speed, the reactor size, and other polymerization conditions. The polymerization conditions are adjusted, for example, the polymerization reaction temperature, the type and amount of the polymerization initiator used, the solid content of the reaction mixture after the reaction of each reactor, and the type of the rubber component in the starting material, among which, in particular, the reaction The arrangement of the reactor, the size of the reactor, and the type of rubber component in the starting material are more likely to affect the ratio of the average value C to the central value B.

The weight average molecular weight of the copolymer in the styrene resin composition of the present invention is not particularly limited, and preferably, the copolymer has a weight average molecular weight ranging from 50,000 to 300,000. More preferably, the copolymer has a weight average molecular weight ranging from 10,000 to 200,000.

Preferably, the styrene resin composition contains 60% by weight to 95% by weight of the copolymer; and 5% by weight to 40% by weight of the rubber particles coated with the styrene-based copolymer. More preferably, the styrene resin composition contains 70% by weight to 90% by weight of the copolymer; and 10% by weight to 30% by weight of the rubber particles coated with the styrene-based copolymer. More preferably, the styrene resin composition contains 75% by weight to 88% by weight of the copolymer; and 12% by weight to 25% by weight of the rubber particles coated with the styrene-based copolymer.

The molded article of the styrene resin composition of the present invention is formed of a styrene resin composition as described above. The formation method can be carried out by a kneading method, a processing molding method, or a combination thereof.

The kneading method can be performed by a Brabender plastometer, a Banbury mixer, a kneading-mixer, a roller press, or a single-axis or two-axis extruder. Usually, after being kneaded by these extruders, the pressed extrudate is cooled and granulated. The kneading mode has an operating temperature range of from 160 ° C to 280 ° C. Preferably, the operating temperature range is from 180 ° C to 250 ° C. The forming method can use injection molding, compression molding, extrusion molding, blow molding, thermoforming, vacuum molding, and hollow molding.

The invention is further described in the following examples, but it should be understood that these examples are for illustrative purposes only and are not to be construed as limiting.

<Example>

In the practice of the present invention, the combinations of the reactors of Examples 1 to 3 are the first reactor R1 (volume 30 liters), the second reactor R2 (volume 10 liters), and the third reactor R3 (volume 30 liters). a fourth reactor R4 (volume 100 liters) and a fifth reactor R5 (volume 100 liters) connected in series, and a sixth reactor R6 (100 liters in volume) in parallel with the first reactor R1, and the sixth The outlet of reactor R6 is connected above the second reactor R2. These reactors are all columnar flow reactors. The reaction temperatures of the reactors are the average of the inlet and outlet regions of each reactor.

<Example 1> Styrene resin composition

The reaction temperatures of the first reactor R1, the second reactor R2, the third reactor R3, the fourth reactor R4, the fifth reactor R5, and the sixth reactor R6 are 96 ° C, 102 ° C, 102 ° C, and 100, respectively. °C, 100 ° C and 120 ° C. The stirring rates of the first reactor R1, the second reactor R2, the third reactor R3, the fourth reactor R4, the fifth reactor R5, and the sixth reactor R6 are 40 rpm, 200 rpm, 120 rpm, 25 rpm, 20 rpm, respectively. 40 rpm.

The first starting material comprises 10.5% by weight of a rubber component, 76.5% by weight of styrene, 13% by weight of ethylbenzene, 900 ppm of 1,1-bis-tert-butylperoxycyclohexane and 1000 ppm of positive- Dodecyl mercaptan. The rubber component comprises 95% by weight of the first rubber component and 5% by weight of the second rubber component. The second starting material contained 87% by weight of styrenic monomer and 13% by weight of ethylbenzene.

The first rubber component comprised 13% by weight of a linear structure styrene-butadiene rubber and 87% by weight of a divergent structure styrene-butadiene rubber. The styrene-butadiene rubber has a Mooney viscosity of 45 and a solution viscosity of 35 cps (measured by a 5% by weight solution of styrene at 25 ° C), wherein 1 of the styrene-butadiene rubber The content of the 2-vinyl monomer unit is in the range of 18% by weight, and the weight average molecular weight of the styrene-butadiene rubber is in the range of 350,000.

The second rubber component contained 58% by weight of a linear structure styrene-butadiene rubber and 42% by weight of a divergent structure styrene-butadiene rubber. The styrene-butadiene rubber had a Mooney viscosity of 55 and a solution viscosity of 170 cps (measured at a concentration of 5% by weight of a styrene solution at 25 ° C). Wherein the content of the 1,2-vinyl monomer unit in the styrene-butadiene rubber is in the range of 12% by weight, and the weight average molecular weight of the styrene-butadiene rubber is in the range of 660,000.

The first starting material is continuously introduced into the first reactor R1 at a flow rate of 38 liters/hour to carry out a polymerization reaction. After the polymerization reaction, a first reaction mixture is formed and introduced into the second reactor R2, wherein the first reaction is carried out. The solids content of the mixture was 16.6% by weight.

The second starting material is continuously introduced into the sixth reactor R6 at a flow rate of 18 liters/hour to carry out a polymerization reaction. After the polymerization reaction, a second reaction mixture is formed and introduced into the second reactor R2, wherein the first starting material is introduced into the second reactor R2. The solid content of the second reaction mixture was 48% by weight.

Mixing the first reaction mixture with the second reaction mixture in the second reactor R2 and continuing the polymerization reaction, and then introducing the third reactor R3, the fourth reactor R4 and the fifth reactor R5 into the reaction The polymerization reaction wherein the solid content of the reaction mixture after the reaction in the second reactor R2 was 30% by weight, and the solid content of the reaction mixture after the reaction in the fifth reactor R5 was 40.5% by weight. The styrene resin composition of the present invention can be obtained by removing a low volatile matter such as an unreacted monomer or a solvent by a devolatilizer. The starting materials, the amounts used, and the polymerization conditions are shown in Table 1, and the evaluation results are shown in Table 2.

Further, according to the method for measuring rubber particles coated with a styrene-based copolymer having a particle diameter of more than 0.4 μm on page 19 of the present specification, the structure of Fig. 1 can be obtained, and the particle diameter difference Ai, the center value B, and The average value C, the results are shown in Table 2.

[Examples 2 to 4]

In Examples 2 to 3, the styrene resin composition was prepared in the same manner as in Example 1, except that the starting material type, the amount used, and the polymerization conditions were changed. The starting materials, the amounts used, and the polymerization conditions are shown in Table 1, and the evaluation results are shown in Table 2.

[Comparative Example 1]

The reactors are combined in such a manner that the first reactor R1 (volume 100 liters), the second reactor R2 (volume 100 liters), the third reactor R3 (volume 100 liters), and the fourth reactor R4 (volume 100) liter). These reactors are all columnar flow reactors. The reaction temperatures of the reactors are the average of the inlet and outlet regions of each reactor.

The reaction temperatures of the first reactor R1, the second reactor R2, the third reactor R3, and the fourth reactor R4 were 97 ° C, 105 ° C, 115 ° C, and 125 ° C, respectively. The stirring rates of the first reactor R1, the second reactor R2, the third reactor R3, and the fourth reactor R4 were 40 rpm, 200 rpm, 60 rpm, and 25 rpm, respectively.

The first starting material comprises 7% by weight of rubber component, 87% by weight of styrene, 6% by weight of ethylbenzene, 1000 ppm of 1,2-bis-tert-butylperoxycyclohexane and 500 ppm of n-dodecane. Mercaptan. The rubber component comprises 94% by weight of the first rubber component and 6% by weight of the second rubber component.

The first rubber component comprised 13% by weight of a linear structure styrene-butadiene rubber and 87% by weight of a divergent structure styrene-butadiene rubber. The styrene-butadiene rubber has a Mooney viscosity of 45 and a solution viscosity of 35 cps (measured by a 5% by weight solution of styrene at 25 ° C), wherein 1 of the styrene-butadiene rubber The content of the 2-vinyl monomer unit is in the range of 18% by weight, and the weight average molecular weight of the styrene-butadiene rubber is in the range of 350,000.

The second rubber component contained 58% by weight of a linear structure styrene-butadiene rubber and 42% by weight of a divergent structure styrene-butadiene rubber. The styrene-butadiene rubber has a Mooney viscosity of 55 and a solution viscosity of 170 cps (measured at a concentration of 5% by weight of a styrene solution at 25 ° C), wherein the styrene-butadiene rubber has 1 The content of the 2-vinyl monomer unit is in the range of 12% by weight, and the weight average molecular weight of the styrene-butadiene rubber is in the range of 660,000.

The first starting material is continuously introduced into the first reactor R1 at a flow rate of 53 liters/hour to carry out a polymerization reaction. After the polymerization reaction, a first reaction mixture is formed and sequentially introduced into the second reactor R2 and the third reaction. And a fourth reactor R4, wherein the first reaction mixture has a solid content of 18% by weight, the reaction mixture after the second reactor R2 has a solid content of 37% by weight, and is in the fourth reactor R4. The reaction mixture after the reaction had a solid content of 35% by weight. The styrene resin composition of the present invention can be obtained by removing a low volatile matter such as an unreacted monomer or a solvent by a devolatilizer. The starting materials, the amounts used, and the polymerization conditions are shown in Table 1, and the evaluation results are shown in Table 2.

Further, according to the method for measuring rubber particles coated with a styrene-based copolymer having a particle diameter of more than 0.4 μm on page 19 of the present specification, the structure of Fig. 2 can be obtained, and the particle diameter difference Ai, the center value B, and The average value C, the results are shown in Table 2.

[Comparative Example 2]

The styrene resin composition was manufactured by Asahi Kasei Co., Ltd., model 403R. The preparation method was prepared by continuous solution polymerization, and the evaluation results are shown in Table 2.

Further, according to the method for measuring rubber particles coated with a styrene-based copolymer having a particle diameter of more than 0.4 μm on page 19 of the present specification, the structure of Fig. 3 can be obtained, and the particle diameter difference Ai, the center value B, and The average value C, the results are shown in Table 2.

【Test items】 1. Impact strength (Izod) evaluation:

The styrene resin compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were injected, and a standard test was prepared in accordance with the standard method of ASTM D-256 (23 ° C, a 1/4 thickness test piece with a notch). The sheet was then tested in accordance with ASTM D-256, unit: Kg-cm/cm.

2. Determination of the content of continuous phase and dispersed phase in styrene resin composition:

The styrene resin compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were dissolved in tetrahydrofuran, and then subjected to a Fourier transform infrared spectrometer (Fourier Transform Infrared Spectrometer, manufactured by Nicolet Co., Ltd., model Nexus). 470) Test, unit: % by weight.

3. Melting coefficient (representing fluidity, melt index, 200 ° C, 5 kg; referred to as MI) evaluation and determination:

The styrene resin compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were tested in accordance with ASTM Standard D-1238 method, and the unit was g/10 minutes.

4. Tensile strength (Tsy) evaluation measurement:

The styrene resin compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were tested in accordance with ASTM D-638, and were measured at a speed of 6 mm/min in units of kg/cm ² .

5. Gloss evaluation:

The styrene resin compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were extruded at 220 ° C into disk test pieces having a thickness of 1/8" (3.17 mm) and a diameter of 5.5 cm, and were BYK Micro-TRI ( The analysis was carried out at a 60 degree angle and measured according to the ASTM D-2457 method in units of %.

In Comparative Example 1, the difference in particle diameter between the styrene copolymer having the largest particle diameter and the styrene copolymer having the smallest particle diameter in the rubber particles coated with the styrene copolymer of the styrene resin composition was found. The central value B is 0.370 μm, and the average value C is 0.103 μm, and the C/B is 27.8%, indicating that the larger particle diameter of the benzene of each of the rubber particles coated with the styrene copolymer in Comparative Example 1 The ethylene-based copolymer and the styrene-based copolymer having a small particle diameter are many, that is, the uniformity of the particle size of the styrene-based copolymer is not good, and the gloss and impact resistance of the styrene-based resin composition are not good.

In Comparative Example 2, the difference in particle diameter between the styrene copolymer having the largest particle diameter and the styrene copolymer having the smallest particle diameter in the rubber particles coated with the styrene copolymer of the styrene resin composition The center value B is 0.300 μm, and the average value C is 0.050 μm, and the C/B is 18%, indicating that the larger particle diameter of the benzene of each of the rubber particles coated with the styrene copolymer in Comparative Example 2 The ethylene-based copolymer and the styrene-based copolymer having a small particle diameter are many, that is, the uniformity of the particle size of the styrene-based copolymer is not good, and the gloss and impact resistance of the styrene-based resin composition are not good.

Further, in Examples 1 to 3, in the rubber particles coated with the styrene-based copolymer of the styrene resin composition of the present invention, the C/B ratio was 10.5% to 12.1%, indicating that each of Examples 1 to 3 was used. The styrene copolymer having a larger particle diameter in a rubber particle is less than the styrene copolymer having a smaller particle diameter, that is, the uniformity of the particle size of the styrene copolymer is good, so that the styrene resin composition is obtained. It has better gloss and impact resistance. From the above results, it was further confirmed that the process of the present invention can effectively produce a styrene resin composition having both good gloss and impact resistance.

As described above, the particle size of the styrene-based copolymer in the rubber particles coated with the styrene-based copolymer is adjusted so that the range of C/B is less than 15%, which in turn makes the styrene-based resin composition high. Gloss and high impact resistance make it possible to achieve the object of the present invention.

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

Figure 1 is a schematic view showing a structural form of a styrene resin composition having a magnification of 25,000 times in a preferred embodiment of the present invention;

Figure 2 is a schematic view showing a structural form in which the styrene resin composition of Comparative Example 1 of the present invention has a magnification of 25,000 times;

Fig. 3 is a schematic view showing a structure in which the styrene resin composition of Comparative Example 2 of the present invention has a magnification of 25,000 times.

Claims (10)

A method for preparing a styrene resin composition, comprising the steps of: subjecting a first starting material to a continuous solution polymerization to form a first reaction mixture, wherein the first starting material comprises a first rubber component, a second rubber component, comprising a monomer component of a styrene monomer and a solvent; and a second starting material is subjected to continuous solution polymerization to form a second reaction mixture, wherein the second starting material comprises a a monomer component comprising a styrene monomer and a solvent; and then, the first reaction mixture is mixed with the second reaction mixture, and subjected to continuous solution polymerization to obtain the styrene resin composition; wherein The first starting material is subjected to continuous solution polymerization at a feed rate of 38 to 40 liters/hour, and the second starting material is subjected to a continuous solution polymerization at a feed rate of 11 to 18 liters/hour; the first rubber The composition comprises 5% by weight to 20% by weight of a linear structure styrene-butadiene rubber and 80% by weight to 95% by weight of a bifurcated styrene-butadiene rubber; the second rubber component comprises 5 0% by weight to 70% by weight of a linear structure of styrene-butadiene rubber and 30% by weight to 50% by weight of a bifurcated styrene-butadiene rubber; the solvent consists essentially of at least one of the following solvents: toluene, Ethylbenzene, xylene, hexane, heptane, cyclohexane, methyl ethyl ketone, acetone and methyl ketone. The method for producing a styrene resin composition according to the first aspect of the invention, wherein the first starting material is continuously introduced into the first reactor R1 for polymerization, and after the polymerization, a first reaction mixture is formed. And introducing the second reactor R2; the second starting material is continuously introduced into the sixth reactor R6, after the polymerization reaction, a second reaction mixture is formed, and introduced into the second reactor R2, and the first The reaction mixture is mixed and a reverse rotation phenomenon occurs in the second reactor R2. The method for producing a styrene resin composition according to the first aspect of the invention, wherein the first reaction mixture has a solid content in the range of 10% by weight to 30% by weight; The solid content of the second reaction mixture after the reaction of the starting materials in the sixth reactor R6 ranges from 30% by weight to 60% by weight. The method for producing a styrene resin composition according to claim 1, wherein the first starting material comprises 5% by weight to 20% by weight of the rubber component, and 55% by weight to 90% by weight and comprises styrene. a monomer component of the monomer, and a solvent of 5 wt% to 25% by weight; the second starting material comprises a monomer component of 75 wt% to 99 wt% of the styrene monomer, and 1 wt% to 25 % by weight of solvent. A styrene-based resin composition obtained by the method according to any one of claims 1 to 4. A styrene resin composition comprising: a copolymer as a continuous phase, the copolymer comprising a styrene monomer unit; and a rubber particle coated with a styrene copolymer as a dispersed phase; In the rubber particles of the styrene-based copolymer, n rubber particles coated with a styrene-based copolymer having a particle diameter of more than 0.4 μm are collected, and the center value B and the average value C are calculated by the following two formulas: the central value , Ai represents the particle diameter difference between the styrene copolymer having the largest particle diameter and the styrene copolymer having the smallest particle diameter in the rubber particles coated with the styrene copolymer having the i-th particle diameter of more than 0.4 μm; value Where C/B is less than 15%. The styrenic resin composition according to claim 6, wherein the C/B range is less than 13%. The styrenic resin composition according to claim 6, wherein the C/B range is less than 11%. The styrene resin composition according to claim 6, wherein the central value B is in a range of less than 0.29 μm. A molded article of a styrene resin composition, which is formed from a styrene resin composition as described in any one of claims 6 to 9.