TWI418590B - Transparent Rubber Modified Styrene Resin - Google Patents

Description

Transparent rubber modified styrene resin

The present invention relates to a transparent rubber-modified styrene-based resin, and more particularly to a rubber-modified styrene-based resin comprising a continuous phase formed of a copolymer and a dispersed phase containing a plurality of rubber particles.

The rubber-modified styrene-based resin is a material having good strength and processability, and is therefore widely used in household articles, home electric appliances, and outer casings of OA machines such as food containers and packaging materials. However, since the general rubber-modified styrene resin is opaque, it cannot be used for the manufacture of transparent articles. In order to make the rubber-modified styrene resin have both strength and transparency, and to satisfy other desirable properties of the subsequent application (such as chemical resistance, other mechanical properties, etc.), it is known that the styrene resin is The styrene-butadiene block copolymer is kneaded, but this method cannot effectively improve the strength of the rubber-modified styrene resin, and the obtained resin is disadvantageous for subsequent use.

Japanese Laid-Open Patent No. 4-180907 discloses a method for improving the transparency and strength of a rubber-denatured copolymer by grafting styrene with methyl methacrylate in the presence of a block copolymer of styrene-butadiene. Copolymerization. Although this method can improve the transparency and strength of the resin, it cannot meet the demand for high chemical resistance.

Japanese Laid-Open Patent Publication No. 8-239532 provides a transparent rubber-modified styrene resin comprising a styrene-alkyl (meth) acrylate copolymer and a styrene-butadiene rubber having the same refractive index. Although the resin of this patent can improve the transparency and impact resistance of the resin, the chemical resistance and physical properties of the resin cannot be improved.

From the above, it is known that an ideal transparent rubber-modified styrene-based resin is required to have both chemical resistance and the like in addition to physical properties, so as to satisfy the current demand.

Accordingly, it is an object of the present invention to provide a transparent rubber-modified styrene-based resin which combines good strength, chemical resistance and other mechanical properties.

Thus, the transparent rubber-modified styrenic resin of the present invention comprises: a dispersed phase (A) comprising a plurality of rubber particles formed of a rubbery copolymer, and a continuous phase (B) formed by a copolymer; In the dispersed phase (A), the rubber particles have an average particle diameter of 0.2 to 0.55 μm, and the rubbery copolymer is a linear block copolymer, and includes 10 to 50% by weight of a polystyrene block, and 50 to 90 wt% of a polybutadiene block; in the continuous phase (B), the copolymer comprises 21 to 55 parts by weight of a styrene monomer unit, and 23 to 70 parts by weight of a (meth)acrylic acid. An ester monomer unit, and 9 to 22 parts by weight of the acrylonitrile monomer unit; and a yield difference of the copolymer continuous phase (B) and the rubbery copolymer of <0.01.

The transparent rubber-modified styrene-based resin of the present invention transmits the specific components and composition of the dispersed phase (A) and the continuous phase (B), so that the transparent rubber-modified styrene-based resin composition of the present invention has high chemical resistance, transparency, Properties such as rigidity (tensile strength), elongation, etc., and a good balance between properties can be achieved.

The transparent rubber-modified styrene resin of the present invention comprises a dispersed phase (A) comprising a plurality of rubber particles formed of a rubbery copolymer, and a continuous phase (B) formed by a copolymer; In (A), the rubber particles have a weight average particle diameter of 0.2 to 0.55 μm, and the rubbery copolymer is a linear block copolymer, and includes 10 to 50% by weight of a polystyrene block, and 50~ 90 wt% polybutadiene block; in the continuous phase (B), the copolymer comprises 21 to 55 parts by weight of styrene monomer units, and 23 to 70 parts by weight of (meth) acrylate system a monomer unit, and 9 to 22 parts by weight of an acrylic monomer unit; and a difference in yield of the continuous phase (B) of the copolymer and the rubbery copolymer is <0.01.

Hereinafter, the dispersed phase (A) of the rubber particles formed by a rubbery copolymer and the continuous phase (B) formed by the copolymer are respectively described in detail:

[Dispersed phase (A) of rubber particles formed from a rubbery copolymer]

The rubbery copolymer is obtained by an anionic polymerization reaction of a styrene monomer, a butadiene monomer, and an appropriate amount of a solvent in the presence of an organic solvent and an organolithium compound initiator. Among them, 5 wt% of styrene monomer solution has a viscosity of 3 to 60 cps at 25 °C.

Preferably, the rubbery copolymer has a Moony viscosity (ML ₁₊₄ ) ranging from 20 to 80.

The rubbery copolymer structure is a linear block copolymer, and the structure thereof may be: a homopolymer block structure, a partial random block structure, and an increasing composition. Block-block construction.

This linear construction includes but is not limited to:

(1)(AB) _n

(2)A BA) _n

(3)B AB) _n

Wherein A represents a polystyrene block, B represents a polybutadiene block, and the boundary between the A block and the B block does not necessarily need to be clearly distinguished, and n=1 or an integer of 1 or more.

Preferably, the rubbery copolymer has a linear block structure, more preferably an incremental block structure. It should be particularly noted that the increasing block structure of the composition is not limited to the styrene incremental block structure, or the butadiene incremental block structure, wherein A-(B/A)-B, BA - (B/A)-A or B-(B/A)-AA-(B/A)-B is more preferred.

Preferably, 8 wt% or more of the polybutadiene block is a 1,2-vinyl structure.

Preferably, the styrenic monomer is selected from the group consisting of: styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, o-methylstyrene, ethylstyrene , 2,4-dimethylstyrene, p-tert-butylstyrene, α-methyl-p-methylstyrene, bromine-styrene, dibromo-styrene, 2,4,6-three Bromostyrene, or a combination of these.

Preferably, the butadiene monomer is selected from the group consisting of: 1,2-butadiene, 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-double -Methyl-1,3-butadiene, or a combination of these. More preferably, the butadiene monomer is 1,2-butadiene or 1,3-butadiene.

The organolithium compound initiator is a compound containing one or more lithium atoms in the molecule. Preferably, the organolithium compound initiator is selected from the group consisting of ethyl lithium, n-pentyl lithium, isopropyl lithium, n-butyl lithium, secondary butyl lithium, hexyl lithium, cyclohexyl lithium, benzene. Lithium, benzyl lithium, naphthyllithium, tert-butyllithium, trimethylenedilithium, tetramethylenedilithium, butadiene dilithium and isoprene dilithium, or one of these combination.

Preferably, the rubbery copolymer has a polymerization rate, a 1,2-vinyl content, a reactivity ratio of a butadiene monomer to a styrene monomer, and a random state, which is permeable to a polar compound or none. Regulators to adjust. More preferably, the polar compound or randomizer is selected from the group consisting of ethers, amines, thioetheramines, alkylbenzenes, sulfons, and potassium or sodium salts of alkyl oxides. .

When the content of the polyethylene block in the rubber copolymer is less than 10% by weight or the content of the polybutadiene block is more than 90% by weight, the transparency of the rubber-modified styrene-based resin may be deteriorated. Preferably, the rubbery copolymer comprises 15 to 40% by weight of the polystyrene block and 60 to 85% by weight of the polybutadiene block, based on 100% by weight of the rubbery copolymer.

The rubber particles have a weight average particle diameter (Dw) of 0.2 to 0.55 μm. When the weight average particle diameter of the rubber particles is less than 0.2 μm, the impact resistance of the rubber-modified styrene resin decreases; when the weight average particle diameter of the rubber particles is more than 0.55 μm, the transparency of the rubber-modified styrene resin not ideal. Preferably, the rubber particles have a weight average particle diameter of 0.3 to 0.48 μm.

The above weight average particle diameter is obtained by taking an ultra-thin sectioning method by an electron microscope and calculating by the following formula, and the photograph contains at least 300 particles or more:

Wherein ni represents the particle diameter of the rubber particles; Di represents the number of rubber particles.

[Continuous phase formed by the copolymer (B)]

In the continuous phase (B) formed by the copolymer, the copolymer comprises 21 to 55 parts by weight of a styrene monomer unit, 23 to 70 parts by weight of a (meth) acrylate monomer unit, and 9 to 9 22 parts by weight of an acrylonitrile monomer unit. When the content of the acrylonitrile monomer unit is less than 9 parts by weight, the chemical resistance, rigidity (tensile strength) and elongation properties of the rubber-modified styrene resin are not satisfactory; when the acrylonitrile monomer unit is When the content is more than 22 parts by weight, the transparency and impact strength of the rubber-modified styrene-based resin are deteriorated.

Preferably, the copolymer comprises 21 to 55 parts by weight of a styrene monomer unit, 24 to 68 parts by weight of a (meth) acrylate monomer unit, and 11 to 21 parts by weight of an acrylonitrile monomer. unit. More preferably, the copolymer comprises 21 to 55 parts by weight of a styrene monomer unit, 23 to 67 parts by weight of a (meth) acrylate monomer unit, and 12 to 20 parts by weight of an acrylonitrile monomer. unit.

Preferably, the type and other variations of the styrene monomer of the continuous phase (B) of the copolymer are the same as those of the styrene monomer of the rubber copolymer, and the description thereof will not be repeated here.

Preferably, the (meth) acrylate monomer is selected from a methacrylate or acrylate monomer. The methacrylates include, but are not limited to, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and the like; and the acrylates include, but are not limited to, methyl acrylate, ethyl acrylate, and butyl acrylate. Ester, 2-methylpentyl acrylate, 2-ethylpentyl acrylate, octyl acrylate, and the like. More preferably, the (meth) acrylate monomer is methyl methacrylate or methyl acrylate.

The acrylonitrile-based monomer may be, for example but not limited to, acrylonitrile, α-methacrylonitrile or the like.

Preferably, the continuous phase of the copolymer (B) may optionally contain from 0 to 40 parts by weight of other copolymerizable monomer units.

The type of the copolymerizable monomer is not particularly limited, and the content ratio of the various copolymerized monomer units may be matched as needed to adjust the refractive index of the copolymer so that the obtained rubber-modified styrene-based resin does have Transparency.

Specific examples of the copolymerizable monomer are (1) unsaturated fatty acids: itaconic acid, maleic acid, fumaric acid, crotonic acid, cinnamic acid, etc.; Maleimide: nitrogen-methyl maleimide, nitrogen-ethyl maleimide, nitrogen-butyl maleimide, nitrogen-octyl maleimide, Nitrogen-isopropylmaleimide, nitrogen-phenylmaleimide, nitrogen-p-bromo-phenylmaleimide, nitrogen-o-chloro-phenylmaleimide, nitrogen - cyclohexane-maleimide, etc.; (3) unsaturated carboxylic anhydrides: maleic anhydride, itaconic anhydride, citraconic anhydride, etc.; (4) amine-containing unsaturated compounds: allylamine (amino)ethyl (meth) acrylate, aminopropyl (meth) acrylate, etc.; (5) acrylamide-based compound: acrylamide, N-methyl acrylamide, and the like.

The polymer structure of the continuous phase (B) of the copolymer may be linear or divergent, wherein the divergent polymer may provide the transparent rubber-modified styrene resin with better impact strength. The continuous phase (B) of the copolymer having a divergent structure can be obtained by a prior art, for example, adding a polyfunctional unsaturated group-containing monomer, a starter, a polyfunctional chain transfer agent, or one of the above or A combination of several monomers or reagents.

[Transparent rubber-modified styrene resin]

Preferably, the transparent rubber-modified styrene resin comprises a dispersed phase (A) of rubber particles formed by 5 to 25 wt% of a rubbery copolymer, and a copolymer continuous phase (B) of 75 to 95% by weight. When the content of the dispersed phase (A) of the rubber particles formed by the rubbery copolymer is less than 5% by weight, the strength of the resin may be lowered; if it exceeds 25% by weight, the transparency of the resin may be lowered.

The content of the insoluble matter in the transparent rubber-modified styrene-based resin of the present invention is not particularly limited, and is usually 2 to 40% by weight, preferably 8 to 35% by weight, more preferably 12 to 30% by weight. When the insoluble content is less than 2% by weight, the rubber-modified styrene-based resin has insufficient impact strength, and when the content of the insoluble content is more than 40% by weight, the rubber-modified styrene-based resin has poor transparency.

The swelling index of the transparent rubber-modified styrene-based resin of the present invention is also not particularly limited, and is usually 2 to 25, preferably 3 to 20, more preferably 5 to 15. When the swelling index is not in the range of 2 to 25, the physical properties (especially impact strength) and transparency of the transparent rubber-modified styrene resin cannot satisfy the demand.

The above-mentioned insoluble content and swelling index are measured by dissolving 1 g of the resin in a mixed solvent of 1:1 toluene and acetone, dissolving at 25 ° C for 24 hours, and then centrifuging in a centrifuge (15,000 rpm) for 20 minutes. After the separation, the lower layer liquid was taken out and weighed to obtain the insoluble weight after swelling. Further, the insoluble portion after swelling was vacuum dried at 80 ° C for 12 hours to obtain a dry insoluble portion and weighed. Calculate the insoluble content (wt%) and the swelling index using the following formula:

In the method for producing a transparent rubber-modified styrene-based resin of the present invention, the rubber-like copolymer is batch-wise or continuous with a styrene-based monomer, a (meth)acrylic monomer, and an acrylonitrile-based monomer. Bulk or solution graft polymerization. In the above process, other copolymerizable monomers are optionally added for the reaction.

In the continuous solution graft polymerization, first, the rubbery copolymer, the styrene monomer, the (meth)acrylic monomer, and the acrylonitrile monomer are added to a solvent to form a raw material mixed solution. Dissolving the raw material mixed solution, for example, in a conventional dissolution tank having a high shear stress and a high stirring speed, and the dissolution tank may have, for example, a belt-shaped spiral stirring blade, a propeller stirring blade, or the like, which may be high. The dissolution tank of the stirring blade of the shear force. After sufficient time is passed, the rubbery copolymer is completely dissolved into a state of a rubber solution to facilitate pumping of the raw material mixed solution to the reactor. The raw material mixed solution or the monomer solution is continuously fed into the first reactor and/or the second reactor, and/or the subsequent reactor thereof, respectively, and is required to be in the first and/or second and/or The subsequent reactor adds a chain transfer agent and a starter to promote the progress of the graft polymerization.

The reactor may be, for example, the same or a combination of different types of continuous stirred reactor (CSTR), plug flow reactor, static reactor. The reaction temperature is controlled at 70-230 ° C, and the final monomer conversion rate can reach 30-95%, but 50-90% is preferred.

Preferably, the rubber-modified styrene resin is polymerized by using a continuous stirred reactor for the first reactor, followed by a second and/or subsequent reactor, and the subsequent reactor may be a continuous stirred reaction. , plug flow reactor or static hybrid reactor.

The monomer conversion of the first reactor is about 1 to 30 wt%, preferably 2 to 25 wt%, more preferably 3 to 22 wt%. The monomer conversion rate of the first reactor is selected according to the type of the rubber copolymer content selected, the viscosity, etc., in order to prevent the reverse reaction of the rubber from occurring in the first reactor. The reverse conversion reaction is carried out in a subsequent reactor (e.g., the second or third reactor), so that the obtained rubber-modified styrene-based resin can obtain good physical properties.

The solvent is selected from aromatic hydrocarbons, ketones or esters. Preferably, the solvent is selected from the group consisting of toluene, ethylbenzene, xylene, methyl ethyl ketone, ethyl acetate, or a combination thereof; in addition, the solvent may be mixed with an aliphatic hydrocarbon, the aliphatic hydrocarbon The compound is selected from n-ethane, cyclohexane or n-heptane.

Preferably, the initiator is added in an amount of from 0 to 2 parts by weight, more preferably from 0.001 to 0.7 parts by weight, based on 100 parts by weight of the continuous phase. The initiator may be, for example but not limited to, dibenzoyl peroxide, dicumyl peroxide, dibenzoyl superoxide, tributyl peroxide. (t-butyl peroxide), hydrogen peroxide, t-butylhydroxy peroxide, cumene hydroperoxide, t-butyl peroxybenzoate , di-2-ethylhexyl peroxy dicarbonate, tert-butyl peroxy isopropyl carbonate (BPIC), cyclohexanone peroxide (cyclohexanone peroxide), 2,2'-azo-bis-isobutyronitrile, 1,1'-azo-bis-1-cyclohexanecarbonitrile (1 , 1'-azo-bis-1-cyclohexanecarbonitrile, 2,2'-azo-bis-2-methylbutyronitrile, azo-bis-iso Azo-bis-isobutyronitrile, 1,1-di-t-butylperoxycyclohexane (TX-22), 1,1-di-peroxidation Tributyl-3,3,5-trimethylcyclohexane (1 , 1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 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-(peroxy-tert-butylcarbonyl)-3-hexyl-6-[7-(peroxybutyl carbonyl) {h>butyl-cycloperoxy carbonyl-3-hexyl-6-[7-(t-butyl peroxycarbonyl)heptyl]cyclo-hexane}, di-tert-butyl diperoxide Acid (di-t-butyl-diperoxyazelate), 2,5-dimethyl-2,5-bis(benzophenone)-hexane [2,5-dimethyl-2,5-bis-(benzoyl peroxy) Dimethyl]-di-per-butyl peroxy-hexahydro-terephthalate (BPHTP), and 2,2-bis(4,4-di-) Tributyl butyl peroxy) cyclohexanyl propane [2,2-bis-(4,4-di-t-butylperoxy)cyclohexanyl propane].

Preferably, the chain transfer agent is added in an amount of from 0 to 2 parts by weight, more preferably from 0.01 to 0.7 parts by weight, based on 100 parts by weight of the continuous phase (B). The chain transfer agent can be, for example but not limited to, the following specific examples:

1) Mercaptans: methyl mercaptan, n-butyl mercaptan, cyclohexyl mercaptan, n-dodecyl mercaptan, stearyl mercaptan, third-ten T-dodeyl mercaptan (TDM), n-propyl mercaptan, n-octyl mercaptan, tri-octyl mercaptan, tri-decyl mercaptan, and the like.

2) alkyl amines: monoethylamine, diethylamine, triethylamine, monoisopropylamine, dimonopropylamine, monobutylamine, di-n-butylamine, three - n-butylamine and the like.

3) Pentaerythritol tetrakis (3-mercapto propionate), pentaerythritol tetrakis (2-mercapto ethanate), four (4) -mercaptoic acid)pentaerythritol tetrakis(4-mercaptobutanate), pentaerythritoltetrakis (5-mercapto pentanate), tetrakis(6-mercaptohexanoic acid) Pentaerythritol tetrakis (6-mercapto hexanate), tris-(2-mercaptoacetate) trimethylolpropane tris (2-mercapto ethanate), tris-(3-mercaptopropionic acid) trishydroxyl Trimethylolpropane tris (3-mercapto propionate, TMPT for short), trimethylolpropane tris (4-mercapto butanate), tris-(5-mercaptovaleric acid) Trimethylolpropane tris (5-mercapto pentanate), trimethylol-propane tris (6-mercapto hexanate), and the like.

4) Others: pentaphenylethane, α-methyl styrene dimer, terpinolene.

Preferably, the polyfunctional unsaturated group monomer is added in an amount of 0 to 1 part by weight, more preferably 0.005 to 0.6 part by weight, based on 100 parts by weight of the continuous phase, and specific examples thereof are as follows:

1) Divinyl benzene, 1,2,4-trivinyl benzene, 1,3,5-trivinylbenzene (1,3,5-trivinyl Vinylbenzenes such as benzene).

2) ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol diacrylate Polyethylene glycol dimethacrylate, 1,3-propylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, 1, A triacrylate such as 1,6-hexanene glycol dimethacrylate, neopentyl alcohol, or triethylol ethane triacrylate.

3) Tetraacrylate such as tetramethylol methanetetraacrylate.

After the polymerization reaction, the raw material mixed solution is taken out from the reactor and placed in a devolatilization device, and the devolatilizer is used to remove low volatiles such as residual monomers, solvents, dimers, triads, etc., and recovered. After the polymer, the transparent rubber-modified styrene-based resin of the present invention can be obtained.

Preferably, after the devolatilization treatment, the volatile matter in the resin is reduced to 1 wt% or less, more preferably 0.8 wt% or less, still more preferably 0.5 wt% or less.

The devolatilization device can be, for example, a uniaxial or biaxial extruder with a devolatilization, and a devolatilization aid such as water, cyclohexane, carbon dioxide or the like can be added to the extruder as needed. Preferably, the extruder may also be provided with a kneading zone, a push section, and the like as needed. Preferably, the screw speed is 120 to 350 rpm.

In addition, other devolatilization devices such as thin film evaporators may be employed, or one or a plurality of devolatilization tanks with vacuuming equipment may be used in series. Preferably, the temperature of the devolatilization tank is controlled at 180 to 350 ° C, preferably 200 to 320 ° C, more preferably 220 to 300 ° C. Preferably, the degree of vacuum of the devolatilizer is controlled to be 300 torr or less, more preferably 200 torr or less, still more preferably 100 torr or less.

In the range which does not significantly impair the effect of the rubber-modified styrene-based resin of the present invention, an additive may be added in the above polymerization process, and may be added at the polymerization reaction stage or after completion of the reaction as needed. The additive may be, for example but not limited to: a coloring agent, a filler, a flame retardant, a flame retardant (such as antimony trioxide, etc.), a light stabilizer, a thermal stabilizer, a plasticizer, a slip agent, a release agent, and a viscosity-increasing agent. Agent, charge inhibitor, oxidation inhibitor, conductive agent, etc.; specific examples of the additive: mineral oil, such as butyl stearate ester plasticizer, polyester plasticizer, such as organic polyoxane, such as poly Dimethyl decane, higher fatty acids and metal salts thereof, hindered amine-based antioxidants, glass fibers, and the like may be used singly or in combination.

Preferably, the ester-based plasticizer or mineral oil is added in an amount of 0 to 5 wt%, more preferably 0.05 to 2 wt%, based on 100% by weight of the resin.

Preferably, the organopolysiloxane is added in an amount of from 0 to 0.5% by weight, more preferably from 0.002 to 0.2% by weight, based on 100% by weight of the resin.

Further, other resins may be further added to prevent or improve the heat resistance, rigidity, and flow processability of the resin without impairing the transparency of the rubber-modified styrene resin of the present invention. Preferably, the other resin is added in an amount of 0 to 200 parts by weight based on 100 parts by weight of the resin, and specific examples thereof are, for example but not limited to, styrene-(meth)acrylate-acrylonitrile. Copolymer, styrene-based (meth)acrylate copolymer, styrene-based (meth)acrylate-acrylonitrile-maleimide copolymer, styrene-(methyl An acrylate-maleimide copolymer, a (meth)acrylate-maleimide copolymer, or a copolymer modified (or graft modified) with a diene rubber .

The use of the rubber-modified styrene-based resin of the present invention is not particularly limited, and can be applied to various molded articles such as injection molding and compression molding, or finished products obtained by extrusion molding, blow molding, thermoforming, vacuum molding, and hollow molding. For example, a plate, a film molded product, etc., and the formulation can be adjusted according to requirements to make the resin have high fluidity and high heat resistance.

The addition of the additive or other resin to the rubber-modified styrene-based resin is not particularly limited in order, and may be performed by a Brabender plastometer, a Banbury mixer, a kneader-mixer, a roller press, a shaft or A general mixing and kneading machine such as a two-axis extruder is prepared by mixing and kneading. Usually, after the mixing and kneading, the pressed extrudate is cooled and granulated. Preferably, the kneading is carried out at 160 to 280 ° C, more preferably 180 to 250 ° C.

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

<Examples 1 to 4> [Example 11]

12 parts by weight of the rubbery copolymer, 33 parts by weight of styrene monomer, 52 parts by weight of methyl methacrylate monomer, 15 parts by weight of acrylonitrile monomer, 33 parts by weight of ethylbenzene, and dibenzoguanidine peroxide 1000 ppm was uniformly mixed to form a feed solution. Wherein, the rubbery copolymer is a linear increasing block copolymer of Mooney viscosity 45, containing 25 wt% of polystyrene block, and 75 wt% of polybutadiene block, wherein 1,2-vinyl content Accounting for 15.4 wt%. The block copolymer contains one polystyrene block, one polybutadiene block, and one styrene/butadiene block in which the styrene component is gradually increased.

The feed solution was continuously pumped at a flow rate of 35 kg/hr to a continuous polymerization unit in series of four fully mixed continuous stirred reactors (each having a capacity of 40 liters). Wherein, the reaction temperature of the first reactor was controlled at 99 ° C, the reaction temperature of the second reactor was controlled at 102 ° C, the reaction temperature of the third reactor was controlled at 120 ° C, and the reaction temperature of the fourth reactor was controlled at 134 ° C. After the reaction solution was reacted, the conversion rate was about 57%, and the retort equipment was extruded to obtain the transparent rubber-modified styrene resin of Example 1. The composition and content ratio of the feed solution of Example 1 are described in detail in Table 1.

[Examples 2 to 4 and Comparative Examples 1 to 6]

The polymerization conditions and preparation methods of Examples 2 to 4 and Comparative Examples 1 to 5 were substantially the same as those of Example 1, except for the composition and content ratio of the feed solution, and the polymerization reaction conditions. The polymerization conditions and preparation methods of Comparative Example 6 were substantially the same as in Example 1, except for the rubbery copolymer used, the composition and content ratio of the feed solution, and the polymerization conditions. The compositions and content ratios of the feed solutions of Examples 2 to 4 and Comparative Examples 1 to 6 are described in detail in Table 1. The characteristics of the respective components in the preparation processes of Examples 2 to 4 and Comparative Examples 1 to 6 are shown in Table 2, respectively.

[Physical property test]

The following physical properties of the resins of Examples 1 to 4 and Comparative Examples 1 to 6 were respectively analyzed, and the results are shown in Table 2 in detail.

First, chemical resistance (oil resistance):

The resin was injection molded into a 23 cm long test piece, and the test piece was fixed on a bow tester to form a curved bow shape, and then the surface of the test piece was coated with olive oil, and then left at room temperature, and observed after 6 hours. Appearance and the results are recorded in Table 2.

○: indicates that the appearance of the test piece did not change.

△: indicates that the test piece has a slight crack appearance.

×: indicates that the test piece has a severe crack.

Second, impact resistance (IZOD):

The Izod impact strength was measured according to the ASTM D-256 measurement standard, and a 1/4 inch thick test piece with a notch at 23 ° C was used.

Third, transparency (also known as haze, Haze):

The resin was injection molded into a test piece of 3 mm thickness, and transparency was measured in accordance with ASTM D-1003 test standard, wherein a higher transparency value indicates poorer transparency.

Fourth, the content of polystyrene block (wt%) determination:

The rubbery copolymer is added to 1,2-dichloro-benzene, and after heating, the rubbery copolymer is dissolved, and then a t-butylydroperoxide solution and osmium tetroxide are added and mixed. Continue to heat for 15 minutes, add methanol and sulfuric acid after cooling, then filter with filter paper, dry, weigh, and calculate by the following formula:

Polystyrene block content (wt%) = net residue after filtration / rubber copolymer weight × 100%

5. Determination of tensile strength (TSy):

Determined by ASTM D-638 standard method, measured at a speed of 6 mm/min, in units of kg/cm ² .

6. Determination of elongation (EL):

Determined according to ASTM D-638 standard method, measured at a speed of 6 mm/min, in %.

7. Determination of the proportion of monomer units contained in the copolymer of continuous phase (B):

The transparent rubber-modified styrene-based resin was dissolved in tetrahydrofuran (THF) and pulled, and then tested by a Fourier transform infrared spectrometer (FT-IR, manufactured by Nicolet Co., model Nexus 470).

Referring to Table 2, it was found from the experimental results of Comparative Examples 1 to 3 that the content of the acrylonitrile monomer unit in the continuous phase (B) of the copolymer of the transparent rubber-modified styrene resin was less than 9 parts by weight, or no propylene. In the case of a nitrile monomer unit, the resin has poor physical properties such as chemical resistance, rigidity (tensile strength), and poor elongation.

From the experimental results of Comparative Example 4, when the content of the acrylonitrile monomer unit of the continuous phase (B) of the copolymer in the transparent rubber-modified styrene resin is more than 22 parts by weight, the transparency and impact strength of the resin. difference. From the experimental results of Comparative Example 5, it was found that the rubbery copolymer in the rubber-modified styrene resin used a non-linear block structure containing no polystyrene block, and the styrene system of the continuous phase of the copolymer (B) When the content of the monomer unit is too small, the resin has poor transparency and rigidity (tensile strength) and the like, and the weight average particle diameter of the rubber particles is too large. Comparative Example 6 used a rubber-like copolymer having a non-polystyrene block-free nonlinear block structure, which was poor in transparency and rigidity (tensile strength), and had a difference in weight average particle diameter and yield of rubber particles. is too big.

The transparent rubber-modified styrene-based resin of Examples 1 to 4 has better chemical resistance and processability, and also has good transparency and physical property balance, and is a resin having industrial use value.

In summary, the transparent rubber-modified styrene resin of the present invention not only allows the resin to have good transparency by adjusting the specific component ratio, but also makes the obtained resin have good chemical resistance, processability and elongation. It is a transparent rubber-modified styrene resin composition with good balance of properties and impact resistance.

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.

Claims (6)

A transparent rubber-modified styrene-based resin comprising: a dispersed phase (A) comprising a plurality of rubber particles formed of a rubbery copolymer, and a continuous phase (B) formed by a copolymer; in the dispersed phase In (A), the rubber particles have a weight average particle diameter of 0.2 to 0.55 μm, and the rubbery copolymer is a linear block copolymer, and includes 10 to 50% by weight of a polystyrene block, and 50~ 90 wt% polybutadiene block; in the continuous phase (B), the copolymer comprises 21 to 55 parts by weight of styrene monomer units, and 23 to 70 parts by weight of (meth) acrylate system a monomer unit, and 9 to 22 parts by weight of an acrylic monomer unit; and a difference in yield of the copolymer and the rubber-like copolymer is <0.01. The transparent rubber-modified styrene-based resin according to claim 1, wherein the copolymer contains the styrene-based monomer unit 21 by weight based on 100 parts by weight of the copolymer in the continuous phase (B). 55 parts by weight, 24 to 68 parts by weight of the (meth) acrylate monomer unit, and 11 to 21 parts by weight of the acrylonitrile monomer unit. The transparent rubber-modified styrene-based resin according to claim 1, wherein the copolymer contains the styrene-based monomer unit 21 by weight based on 100 parts by weight of the copolymer in the continuous phase (B). 55 parts by weight, 23 to 67 parts by weight of the (meth) acrylate monomer unit, and 12 to 20 parts by weight of the acrylonitrile monomer unit. The transparent rubber-modified styrene-based resin according to the first aspect of the invention, wherein the transparent rubber-modified styrene-based resin contains 5 to 25 wt% of the dispersed phase (A), and 75 to 95 wt% of the continuous phase. (B). The transparent rubber-modified styrene-based resin according to the first aspect of the invention, wherein the rubber particles have a weight average particle diameter of 0.3 to 0.48 μm. The transparent rubber-modified styrene-based resin according to claim 1, wherein the rubber-like copolymer comprises a polystyrene block of 15 to 40% by weight based on 100% by weight of the rubber-like copolymer. And the polybutadiene block is 60 to 85 wt%.