JP4833529B2 - Rubber-modified styrenic resin composition - Google Patents

Description

  The present invention relates to a specific rubber-modified styrenic resin composition. More specifically, the present invention relates to a rubber-modified styrenic resin composition having excellent impact resistance and fluidity while having good environmental stress crack resistance and low contamination.

  Styrenic resins have excellent molding processability, mechanical properties, and the like, and the resulting molded products have good appearance and gloss, and thus have been widely applied to the periphery of electronic, electrical products and automobile parts.

  However, the styrene resin has a drawback that it is difficult to achieve a good balance of physical properties. For example, if the molecular weight of the polymer is increased to improve the impact resistance, the fluidity of the resin decreases. On the other hand, when the molding temperature is increased to improve the fluidity, yellowing and thermal decomposition are likely to occur in the molded product, which adversely affects the physical properties of the final molded product. If an attempt is made to improve fluidity by adding a large amount of lubricant instead of high-temperature molding, the mechanical properties are deteriorated. Also, when trying to improve fluidity by molding conditions (for example, increasing the injection pressure during injection molding) instead of adding a large amount of lubricant, the molded product has a lot of residual stress and the molded product has chemical resistance and crack resistance. Deteriorate.

  In order to solve the above problem, in Patent Document 1, a polyfunctional ethylenic compound such as divinylbenzene is added to the polymerization reaction of an aromatic monovinyl group compound to improve resin molding processability and impact resistance. Has been proposed. However, when divinylbenzene is used alone, high fluidity and good impact resistance cannot be obtained at the same time, and the use of divinylbenzene causes excessive high molecular weight crosslinkable foreign matter on the inner wall of the reactor during the copolymerization reaction. As a result, contamination of the final styrene resin increases.

Further, in Patent Document 2, resin processing property and impact resistance are obtained by using 50 to 10,000 ppm of an organic peroxide containing a tetrafunctional group, a bifunctional group and a monofunctional group in a polymerization reaction of an aromatic monovinyl group compound. It has been proposed to improve performance. However, even when the above organic peroxides are used in combination, it is still impossible to obtain high fluidity and good impact resistance at the same time. make worse.
JP-A-2-182711 Japanese Patent Laid-Open No. 9-278816

  An object of the present invention is to provide a styrenic resin composition which imparts high fluidity and good impact resistance, has good environmental stress crack resistance, and has little contamination.

The rubber-modified styrenic resin composition of the present invention is composed of a styrene copolymer (A) as a continuous phase and rubber particles (B) as a dispersed phase. Further, the styrene copolymer (A) contains (i-1) 50 to 90 parts by weight of a styrene monomer, (i-2) 10 to 50 parts by weight of a vinyl cyanide monomer, and (i-3) and others. 0 to 40 parts by weight of the copolymerizable vinyl monomer (the total of which is 100 parts by weight) and 100 parts by weight of the total of (i-1), (i-2) and (i-3). In contrast, 0.0005 to 1.0 part by weight of a polyfunctional maleimide monomer is copolymerized, and this styrenic copolymer (A) is a continuous phase and rubber particles (B) are dispersed phases. The rubber content in the rubber-modified styrene resin composition is 1 to 40% by weight, and the styrene copolymer (A) has a MIR of 21.5 to It is a rubber-modified styrene resin composition having a weight average molecular weight of 30.0 and 60,000 to 145,000.
MIR = HMI / MI
HMI: MFR at 10 kg load at 200 ° C (g / 10 min)
MI: MFR at 1 kg load at 200 ° C (g / 10 min)

  According to the present invention, a styrenic resin composition having high fluidity and good impact resistance, good environmental stress cracking resistance and low contamination is provided.

  Specific examples of the (i-1) styrene monomer used in the present invention include styrene, α-methylstyrene, pt-butylstyrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, Examples include 2,4-dimethylstyrene, ethylstyrene, α-methyl-p-methylstyrene, and bromostyrene. Among them, styrene or α-methylstyrene is preferable. These styrenic monomers can be used alone or in combination. The amount of the (i-1) styrene monomer used is 100 parts by weight of the total amount of the monomers for copolymerization comprising the above (i-1), (i-2) and (i-3). 50 to 90 parts by weight, preferably 55 to 85 parts by weight, more preferably 58 to 80 parts by weight.

  Specific examples of the (i-2) vinyl cyanide monomer used in the present invention include acrylonitrile and α-methylacrylonitrile. Among them, acrylonitrile is preferable. This (i-2) vinyl cyanide monomer is in a total amount of 100 parts by weight of the copolymerization monomers consisting of the above (i-1), (i-2) and (i-3), 10 to 50 parts by weight, preferably 15 to 45 parts by weight, and more preferably 20 to 42 parts by weight.

The (i-3) other copolymerizable vinyl monomer used in the present invention has a vinyl group and (i-1) a styrene monomer of the present invention, (i-2) cyan refers to vinyl based monomer copolymerizable with monomers such as acrylic acid ester monomer, although etc. methacrylic ester monomer are mentioned monofunctional maleimide monomers is not used .

  Here, specific examples of the acrylate monomer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, polyethylene glycol diacrylate, and the like, but butyl acrylate is preferred.

  Specific examples of the methacrylic acid ester monomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, 2-methacrylic acid 2- Hydroxyethyl, glycidyl methacrylate, dimethylaminoethyl methacrylate, ethylene dimethacrylate, neopentyl dimethacrylate and the like can be mentioned, among which methyl methacrylate and butyl methacrylate are preferred.

  The monofunctional maleimide monomer is a monomer containing one maleimide functional group. Specific examples include maleimide, N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide, N- Octylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-2-methylphenylmaleimide, N-2,3-dimethylphenylmaleimide, N-2,4-dimethylphenylmaleimide, N-2, 3-diethylphenylmaleimide, N-2,4-diethylphenylmaleimide, N-2,3-dibutylphenylmaleimide, N-2,4-dibutylphenylmaleimide, N-2,6-dimethylphenylmaleimide, N-2, Examples include 3-dichlorophenylmaleimide, N-2,4-dichlorophenylmaleimide, N-2,3-dibromophenylmaleimide, N-2,4-dibromophenylmaleimide, etc. That is, among them N- phenylmaleimide are preferred.

  Other copolymerizable vinyl monomers include, for example, acrylic acid monomers (for example, acrylic acid and methacrylic acid), maleic anhydride, methylmaleic anhydride, fumaric acid, itaconic acid, and the like. Unsaturated carboxylic acid compounds and ester monomers thereof (eg, dimethyl fumarate, dibutyl itaconate, etc.), ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, ethylene chloride, chloride Examples also include vinylidene, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, butadiene, propenylamine, isobutylenylamine, vinyl acetate, ethyl vinyl ether, methyl vinyl ketone, triallyl isocyanurate and the like.

  The use amount of the other copolymerizable vinyl monomer (i-3) is the total of the copolymerization monomers consisting of the above (i-1), (i-2) and (i-3). In an amount of 100 parts by weight, 0 to 40 parts by weight, preferably 1 to 34 parts by weight, more preferably 3 to 30 parts by weight, most preferably 0 to 30 parts by weight, particularly preferably 0 to 30 parts by weight. 22 parts by weight.

  The polyfunctional maleimide monomer in the present invention refers to a compound having two or more maleimide functional groups. For example, there are 2, 3, or 4 maleimide functional group compounds. The monomer having a maleimide group is preferable, and examples of the structural formula thereof are shown in the chemical formula (1) and the chemical formula (1 ′).

In the above formulas (1) and (1 ′), X is an alkylene group having 1 to 10 carbon atoms, an arylene group, a carbonyl group, —SO ₂ —, —SO—, —O—, —ORO— (R is carbon number) 2 to 10 alkylene groups or arylene groups). In the chemical formula (1 ′), Y and Y ′ are an alkyl group or aryl group having 1 to 4 carbon atoms which may be the same or different from each other.
Specific examples of the polyfunctional maleimide monomer include, for example, N, N′-4,4 ′-(3,3′-dimethyldiphenylmethane) bismaleimide, N, N′-4,4 ′-(3, 3'-diethyldiphenylmethane) bismaleimide, N, N'-4,4'-diphenylmethane bismaleimide, N, N'-4,4'-2,2-diphenylpropane bismaleimide, N, N'-4,4 '-Diphenyl ether bismaleimide, N, N'-3,3'-diphenylsulfone bismaleimide, N, N'-4,4'-diphenylsulfone bismaleimide, N, N'-4,4'-diphenylsulfoxide bismaleimide N, N'-4,4'-benzophenone bismaleimide, bis (4-maleimidophenyloxyphenyl) 2,2-propane, N, N'-1,3-phenylene bismaleimide, etc. , N'-4,4'-diphenylmethane bismaleimide, bis (4-maleimidophenyloxyphenyl) 2,2-propane, N, N'-1,3-phenylenebis Maleimide is preferred.
In the present invention, the amount of the polyfunctional maleimide monomer used is 100 parts by weight of the total amount of the monomers for copolymerization comprising the above (i-1), (i-2) and (i-3). The amount is 0.0005 to 1.0 part by weight, preferably 0.001 to 0.3 part by weight, and more preferably 0.003 to 0.15 part by weight. When the amount of the polyfunctional maleimide monomer used exceeds 1.0 part by weight, the viscosity of the polymer is rapidly increased in the polymerization of the styrene copolymer (A), and cross-linked foreign matters and contamination are likely to occur.

  The styrenic copolymer (A) in the present invention can be produced by a continuous bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, or a reaction apparatus used for these polymerizations. Among these, continuous bulk polymerization or solution polymerization is preferable. Examples of the reaction apparatus include a plug flow reaction apparatus (hereinafter abbreviated as “PFR”), a complete mixing reaction apparatus (hereinafter abbreviated as “CSTR”), and a static mixing reaction apparatus. One, two or three or more reactors can be used together, and preferably three or more reactors are used together. When three or more reactors are used in combination, it is preferable that the first reactor is a fully mixed reactor and the final reactor is a plug flow reactor.

In the present invention, the method for producing the styrene copolymer (A) can carry out the reaction by continuously charging the raw material solution into the reaction apparatus. In that case, it is preferable to add a polymerization initiator, the amount used is 100 parts by weight of the total amount of the copolymerization monomers consisting of the above (i-1), (i-2) and (i-3). The amount is usually 0 to 1 part by weight, preferably 0.001 to 0.5 part by weight. Such a polymerization initiator includes a monofunctional polymerization initiator or a polyfunctional polymerization initiator.
Examples of the monofunctional polymerization initiator that can be used in the present invention include benzoyl peroxide, dicumyl peroxide, t-butyl peroxide, t-butyl hydroperoxide, cumyl hydroperoxide, t-butyl peroxybenzoate, Bis-2-ethylhexyl peroxydicarbonate, t-butylperoxyisopropyl carbonate (hereinafter abbreviated as “BPIC”), cyclohexanone peroxide, 2,2′-azo-bisisobutyronitrile, 1,1′-azobis -(Cyclohexane-1-carbonitrile), 2,2'-azo-bis-2-methylbutyronitrile, dimethyl 2,2'-azobis (2-methylpropionate) and the like. Of these, benzoyl peroxide and dicumyl peroxide are preferred.

  Examples of the polyfunctional polymerization initiator that can be used in the present invention include 1,1-bis- (t-butylperoxy) cyclohexane, 1,1-bis- (t-butylperoxy) -3,3,5- Trimethylcyclohexane (hereinafter abbreviated as “TX-29A”), 2,5-dimethyl-2,5-bis- (2-ethylhexanoylperoxy) hexane, 4- (t-butylperoxycarbonyl) -3- Hexyl-6- [7- (t-butylperoxycarbonyl) heptyl] cyclohexane, di-t-butyl-diperoxyazelate, 2,5-dimethyl-2,5-bis- (benzoylperoxy) hexane , Di-t-butylperoxyhexahydro-terephthalate, 2,2-bis- (4,4-di-t-butylperoxy) cyclohexylpropane (hereinafter abbreviated as “PX-12”), polyfunctional monopar Oxycarbonate (eg ATOFINA, USA) Like the trade name Luperox JWE), etc. is. Of these, TX-29A and PX-12 are preferred.

The reaction temperature in the case of using the above reaction apparatus is usually 20 to 300 ° C, preferably 60 to 250 ° C, more preferably 80 to 240 ° C. When using the reactor, the reaction pressure is controlled between 1 and 10 kg / cm ² . Chain transfer agents can be used to control the molecular weight of the polymer. The amount of the chain transfer agent used is generally 0-2 with respect to 100 parts by weight of the total amount of the monomers for copolymerization consisting of the above (i-1), (i-2) and (i-3). Part by weight, preferably 0.001 to 1 part by weight. Examples of chain transfer agents that can be used in the present invention include monofunctional chain transfer agents and polyfunctional chain transfer agents.

Examples of the monofunctional chain transfer agent that can be used in the present invention include the following.
(1) Mercaptans: methyl mercaptan, n-butyl mercaptan, cyclohexyl mercaptan, n-dodecyl mercaptan, stearyl mercaptan, t-dodecyl mercaptan (hereinafter abbreviated as “TDM”), n-propyl mercaptan, n-octyl mercaptan, t -Octyl mercaptan, t-nonyl mercaptan, 5-t-butyl-2-methyl-thiophenol and the like.

(2) Alkylamines: monoethylamine, diethylamine, triethylamine, isopropylamine, diisopropylamine, butylamine, di-n-butylamine, tri-n-butylamine and the like.

(3) Others: pentaphenylethane, α-methylstyrene dimer, terpinolene and the like.
Among these monofunctional chain transfer agents, n-dodecyl mercaptan and t-dodecyl mercaptan are preferable.

  Polyfunctional chain transfer agents include pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (2-mercaptoacetate), trimethylolpropane tris (2-mercaptoacetate), trimethylolpropane tris (3- Mercaptopropinate) (hereinafter abbreviated as “TMPT”), trimethylolpropane tris (6-mercaptohexanate), 1,8-dimercaptooctane, and the like. Of these, TMPT is preferred.

  The styrenic copolymer (A) is prepared by continuously charging the raw material solution into the reaction apparatus and reacting, and after the conversion of all monomers contained in the raw material solution reaches a predetermined value, the reaction apparatus The polymer solution is continuously taken out from the mixture, introduced into a volatilizer to remove unreacted monomers and volatile components, and then granulated. The conversion rate of all the above monomers can be usually 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more. As the volatilization apparatus, a vacuum devolatilization apparatus or an extrusion devolatilization apparatus can be used, and unreacted monomers and volatile components are recovered with a condenser, and after removing water in the recovered liquid as necessary, the raw material is recovered. Can be used again as a solution.

  In the production of the styrene copolymer (A) in the present invention, a solvent can be added as necessary. The amount of the solvent used is usually 0 to 100 parts by weight with respect to 100 parts by weight of the total amount of the copolymerization monomers consisting of the above (i-1), (i-2) and (i-3). The amount is preferably 0 to 60 parts by weight, more preferably 1 to 50 parts by weight. Examples of the solvent that can be used in the present invention include benzene, toluene, ethylbenzene, p-xylene, o-xylene, m-xylene, pentane, octane, cyclohexane, methyl ethyl ketone, acetone, and methyl isobutyl ketone.

  The weight average molecular weight of the styrenic copolymer (A) in the present invention is 60,000 to 145,000, preferably 65,000 to 120,000, more preferably 70,000 to 115,000. When the weight average molecular weight of the copolymer (A) is less than 60,000, the impact resistance of the rubber-modified styrene resin composition is deteriorated, while the weight average molecular weight of the copolymer (A) is 145,000. If it exceeds, the fluidity of the rubber-modified styrenic resin composition will be insufficient. The weight average molecular weight of the copolymer (A) is controlled by selecting a chain transfer agent and its use amount, selecting a polymerization initiator and its use amount, selecting a solvent and using it in the copolymer (A) copolymerization. The amount, polymerization temperature, polymerization time, or selection of the reactor can be adjusted.

The MIR of the styrenic copolymer (A) in the present invention is usually 21.5 to 30.0, preferably 21.8 to 29.0, and more preferably 22.0 to 28.0. This MIR is the ratio of HMI to MI (HMI / MI), where HMI is MFR at 10 kg load at 200 ° C (g / 10 min), and MI is MFR at 1 kg load at 200 ° C (g / min). 10 minutes). MFR refers to a melt flow index, which can be measured by the ASTM D-1238 method.
The MIR of the styrenic copolymer (A) is the usage amount and addition timing of the polyfunctional maleimide monomer, the selection and usage amount of the polyfunctional polymerization initiator, the selection of the reactor, and the total single amount. The final conversion rate of the product (for example, a part of the use amount of the styrene monomer, polyfunctional maleimide monomer or polyfunctional polymerization initiator of the above (i-1) is the second reactor or the second It can be controlled by adding to the subsequent reactor). Said control method can be used individually or in combination of 2 or more types.

In the present invention, if the following conditions (1) and (2) are satisfied at the same time, the physical properties such as environmental stress crack resistance, impact resistance and fluidity of the rubber-modified styrenic resin composition are improved and contamination is reduced.
(1) In the polymerization of the styrenic copolymer (A), the amount of the polyfunctional maleimide monomer used is a copolymer comprising the above (i-1), (i-2) and (i-3). The amount is 0.0005 to 1.0 part by weight based on 100 parts by weight of the total amount of the monomers for polymerization.
(2) The MIR of the styrene copolymer (A) is 21.5-30.0.

  The present invention is a rubber-modified styrenic resin composition having the styrene copolymer (A) as a continuous phase and the rubber particles (B) as a dispersed phase, and the rubber content is usually 1 to 40% by weight, preferably Is 3 to 35% by weight, more preferably 5 to 30% by weight. When the rubber content is 1 to 40% by weight, the rubber-modified styrenic resin composition has a good balance between fluidity and impact resistance.

  Examples of the method for producing the rubber-modified styrene resin composition of the present invention include a method in which a rubber component is added and reacted in the production of the styrene copolymer (A) (hereinafter referred to as a simultaneous graft method). Alternatively, a method in which a rubber component (for example, a general rubber or a rubber-like graft copolymer, preferably a rubber-like graft copolymer) is directly mixed with the styrene copolymer (A) (hereinafter referred to as a graft blend method) Is mentioned. In the simultaneous grafting method, a general bulk polymerization method, solution polymerization method, emulsion polymerization method, suspension polymerization method, or the like can be employed. Examples of the method for producing the rubber-like graft copolymer include an emulsion polymerization method and an emulsion bulk polymerization method, and the emulsion polymerization method is particularly preferable.

  As the production method for obtaining the rubber-modified styrenic resin composition of the present invention, the above two methods will be described.

[Method 1: Simultaneous grafting method]
In Method 1, the rubber-modified styrene-based resin composition can be produced by using a reactor used for continuous bulk polymerization and solution polymerization. Examples of such a reaction apparatus include a plug flow reaction apparatus (PFR), a complete mixing reaction apparatus (CSTR), and a static mixing reaction apparatus. One, two or three or more reactors can be used together, and preferably three or more reactors are used together. When three or more reactors are used in combination, it is preferable that the first reactor is a fully mixed reactor and the final reactor is a plug flow reactor.
In Method 1, a raw material solution (including a rubber component) is continuously charged into a reaction apparatus to perform a reaction. The reaction temperature in the case of using the above reaction apparatus is usually 30 to 300 ° C, preferably 60 to 250 ° C, more preferably 80 to 240 ° C. The reaction pressure when using the reactor is preferably controlled between 1 and 10 kg / cm ² . In order to control the molecular weight of the polymer, a polymerization initiator or a chain transfer agent can be used as necessary.

  Thereafter, after the conversion rate of all the monomers contained in the raw material solution reaches a predetermined value, this polymer solution is continuously taken out from the reaction apparatus and introduced into a volatilization apparatus to introduce unreacted monomers and volatilization. The rubber-modified styrenic resin composition of the present invention having the styrene copolymer (A) as a continuous phase and the rubber particles (B) as a dispersed phase is obtained by removing the components and then granulating. The conversion rate of all the above monomers can be usually 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more. A vacuum devolatilizer or an extrusion devolatilizer can be used as the devolatilizer, and unreacted monomers and volatile components are recovered with a condenser, and moisture in the recovered liquid is removed as necessary. It can be used again as a raw material solution.

  The raw material solution used for the bulk or solution polymerization reaction for producing the rubber-modified styrene resin composition of the present invention is (i-1) 50 to 90 parts by weight of a styrene monomer, (i-2) vinyl cyanide 10 to 50 parts by weight of monomer and (i-3) 0 to 40 parts by weight (100 parts by weight in total) of other copolymerizable vinyl monomers, and (i-1) and (i-2) ) And (i-3), the polyfunctional maleimide monomer is 0.0005 to 1.0 part by weight, the solvent is 0 to 100 part by weight, and the rubber component is 0.5 to 25 part by weight. Here, styrene monomers, vinyl cyanide monomers, other copolymerizable vinyl monomers, polyfunctional maleimide monomers, solvents and polymerization initiators added as necessary, chain Examples of the amount used and the specific examples of the transfer agent are the same as those described in the raw material solution used for the production of the styrene copolymer (A).

  The rubber-modified styrene resin composition can also be produced by an emulsion polymerization method. The content of the emulsion polymerization method is the same as that of the rubbery graft copolymer (B ′) described later, but a styrene monomer, a vinyl cyanide monomer, and other copolymerizable vinyl resins. The difference lies in the copolymerization of the polyfunctional maleimide monomer in an amount consistent with the present invention along with the monomer.

  In the bulk or solution polymerization reaction for producing the rubber-modified styrenic resin composition of the present invention, a mixed solution of a rubber component and a monomer such as a styrene monomer or a vinyl cyanide monomer is polymerized. Although the rubber phase exists in a state of a continuous phase in the initial stage, the conversion rate of monomers such as a styrene monomer and a vinyl cyanide monomer gradually increases due to the graft polymerization reaction of the rubber component, As the reactor is also stirred, the rubber component is finally surrounded by monomers such as styrene monomers and vinyl cyanide monomers and their polymers (dispersed phase). On the other hand, monomers such as styrene monomers and vinyl cyanide monomers and polymers thereof become continuous phases. Finally, a rubber particle phase is formed in the rubber-modified styrenic resin composition. The weight average particle diameter of the rubber particles is usually 0.05 to 10 μm, preferably 0.1 to 5 μm, more preferably 0.8. It can be 1 to 2 μm.

The rubber in the present invention means a soft polymer having a glass transition temperature of 0 ° C. or lower.
Specific examples of the rubber component used in Method 1 include diene rubber, polyolefin rubber (for example, ethylene-propylene rubber), polyacrylate rubber, polysiloxane rubber, and the like. The diene rubber refers to a polymer obtained by polymerizing a diene monomer component.
Specific examples of such a diene rubber include butadiene rubber, isoprene rubber, chlorobutadiene rubber, ethylene-propylene-ethylidene norbornene rubber, styrene-diene rubber, acrylonitrile-diene rubber, and the like. Among these, as the butadiene rubber, two kinds of polybutadiene rubbers, Hi-Cis and Low-Cis, are preferable. The high cis rubber has a typical weight ratio of cis and vinyl groups of 94 to 99% and 0 to 5%, respectively, the other composition component is a trans structure, and the Mooney viscosity is in the range of 20 to 120. The range of the weight average molecular weight is preferably 100,000 to 800,000. The low cis rubber has a typical weight ratio of cis and vinyl groups of 20 to 40% and 6 to 20%, respectively, the other composition component is a trans structure, and the Mooney viscosity is in the range of 20 to 120. The range of the weight average molecular weight is preferably 100,000 to 800,000.
Specific examples of the styrene-diene rubber include styrene-butadiene rubber and styrene-isoprene rubber, and these may be any of a composition comprising a block copolymer, a random copolymer, or a taper copolymer. The weight ratio of styrene in the styrene-butadiene rubber is preferably in the range of 50% by weight or less, and the weight average molecular weight is preferably 50,000 to 600,000. Of the above rubbers, butadiene rubber and styrene-butadiene rubber are preferred.

[Method 2: Graft kneading method]
Method 2 is a method for producing the rubber-modified styrenic resin composition of the present invention by kneading and extruding a mixture of the styrene copolymer (A) and the rubber-like graft copolymer (B ′).

  In the method 2, a mixture of a styrene copolymer (A) and a rubbery graft copolymer (B ′) is usually dry blended with a commonly used Henschel mixer, and then, for example, an extruder, a kneader, or a banbury. The rubber-modified styrenic resin composition can be produced by melt-kneading with a mixer such as a mixer.

A general continuous bulk reaction, solution polymerization reaction, emulsion polymerization reaction or suspension polymerization reaction can be used for the production method of the rubber-like graft copolymer (B ′).
Regarding the continuous bulk reaction or solution polymerization reaction, the raw material solution can be subjected to a graft polymerization reaction by a continuous bulk reaction or a solution polymerization reaction to obtain a rubber-like graft copolymer (B ′). The raw material solution is (i-1) 50 to 90 parts by weight of styrene monomer, (i-2) 10 to 50 parts by weight of vinyl cyanide monomer, and (i-3) other copolymerizable vinyl. 0 to 40 parts by weight of the monomer (over 100 parts by weight in total) and 100 to 100 parts by weight of the solvent (i-1), (i-2) and (i-3) Part and rubber component 0.5 to 25 parts by weight. A polymerization initiator and a chain transfer agent can be added as necessary. In this raw material solution, a polyfunctional maleimide monomer is not usually used, and when used, it is limited to less than the lower limit of the amount used of the present invention. Here, the styrene monomer, vinyl cyanide monomer, other copolymerizable vinyl monomer, solvent, polymerization initiator and chain transfer agent are used in amounts and specific examples are styrene The same as those described in the raw material solution used for the production of the copolymer (A) can be mentioned, and the explanation regarding the composition of the rubber component is the same as that described in the method 1.

  In the present invention, in the continuous bulk or solution polymerization reaction of the rubber-like graft copolymer (B ′), a mixed solution of a rubber component and a monomer such as a styrene monomer or a vinyl cyanide monomer is Although the rubber phase exists in a continuous phase at the initial stage of polymerization, the conversion rate of monomers such as styrene monomers and vinyl cyanide monomers gradually increases due to the graft polymerization reaction of rubber components. In addition, as the reaction system is stirred, the rubber component is surrounded by monomers such as styrene monomers and vinyl cyanide monomers and polymers thereof and the state of dispersed particles (dispersed particles). On the other hand, monomers such as styrene monomers and vinyl cyanide monomers and polymers thereof become continuous phases. Finally, a rubber particle phase is formed in the rubber-like graft copolymer (B ′). The weight average particle diameter of the rubber particles is 0.05 to 10 μm, preferably 0.1 to 5 μm, more preferably 0.1 to 2 μm. Can do.

  Regarding the emulsion polymerization reaction, the rubber-like graft copolymer (B ′) can be produced by the emulsion polymerization reaction. The production method includes 40 to 90 parts by weight of rubber latex (as solid content) 15 to 95% by weight of styrene monomer, 5 to 50% by weight of vinyl cyanide monomer, and other copolymerizable monomers. A rubber-like graft copolymer latex mixed with 60 to 10 parts by weight of a monomer mixture having a ratio of 0 to 35% by weight, and graft-polymerized using an appropriate emulsifier and initiator and, if necessary, a chain transfer agent And the desired rubber-like graft copolymer (B ′) can be obtained by subjecting to coagulation, dehydration, drying treatment and the like.

The rubber component of the rubber latex is the same as that shown in Method 1, and a diene rubber is particularly preferable.
The production method of the diene rubber latex is, for example, a diene monomer (for example, butadiene) by the emulsion polymerization method, or another copolymerizable monomer such as styrene or acrylonitrile with 100 to 50% by weight of the diene monomer. And a method of polymerizing 0 to 50% by weight of a monomer such as (meth) acrylic acid ester to form a diene rubber latex having a weight average particle size of 0.05 to 0.6 μm.
In addition, the diene monomer is polymerized by an emulsion polymerization method to obtain a diene rubber latex having a small particle size having a weight average particle size of 0.05 to 0.20 μm, and then a freezing method, a homogenizer treatment method, and A method for producing a diene rubber latex having a weight average particle diameter of 0.22 to 0.6 μm and a large particle diameter by agglomerating and enlarging the diene rubber latex having a small particle diameter by an additive aggregation method or the like. Additives used in the additive aggregation method include acid substances such as acetic anhydride, hydrogen chloride and sulfuric acid, salts such as sodium chloride, potassium chloride and calcium chloride, (meth) acrylic acid- (meth) acrylic acid Examples include carboxyl group-containing polymer flocculants such as ester copolymers (for example, methacrylic acid-butyl acrylate copolymer, methacrylic acid-ethyl acrylate copolymer).

  Various additives such as antioxidants, lubricants, UV absorbers, UV stabilizers, antistatic agents, colorants and the like can be added to the rubber-modified styrene resin composition of the present invention as necessary. What is necessary is just to select suitably each polymerization stage of a styrene-type copolymer (A) or each rubber modified styrene-type resin composition, a kneading | mixing extrusion stage, etc. as time. The amount of the additive used is usually 6 parts by weight or less with respect to 100 parts by weight of the rubber-modified styrenic resin composition. Other additives such as flame retardants and impact modifiers can be added as necessary, and the amount used is usually 30 parts by weight or less with respect to 100 parts by weight of the rubber-modified styrenic resin composition.

  In the rubber-modified styrene resin composition of the present invention, various polymers other than the styrene copolymer (A) can be mixed and used as necessary. That is, in the case of the rubber-modified styrene resin composition, the continuous phase can contain various polymers other than the styrene copolymer (A). These polymers include acrylonitrile-butadiene-styrene copolymers, acrylonitrile-styrene copolymers, acrylonitrile-butadiene-alphamethylstyrene copolymers, acrylonitrile-styrene-methyl methacrylate copolymers, acrylonitrile. -Styrene-N-phenylmaleimide copolymer, styrene-maleic anhydride copolymer, styrene-N-phenylmaleimide copolymer, methyl methacrylate copolymer, polycarbonate, styrene-methyl acrylate copolymer Polymer, methyl acrylate-butadiene-styrene copolymer, acrylonitrile-butadiene-N-phenylmaleimide-styrene copolymer, polyamide, polyester, polyphenylene ether, acrylonitrile-acrylate rubber-styrene copolymer, acrylo Examples include nitrile- (ethylene-propylene rubber) -styrene copolymers, acrylonitrile-silicone rubber-styrene copolymers, and other polymers. These polymers can be used alone or in combination. The amount of these other polymers used is usually 80 parts by weight or less with respect to 100 parts by weight of the flame retardant styrene resin composition.

  The resin composition of the present invention is particularly suitable for injection molding as a thermoplastic resin because of its excellent balance of physical properties, fluidity, and appearance.

  The present invention will be described more specifically with reference to the following examples and comparative examples. However, the present invention is not limited to the following examples.

<Synthesis Example of Styrene Copolymer (A)>
“Synthesis Example a: Synthesis of Styrene Copolymer (A-1)”
Styrene monomer (hereinafter abbreviated as “SM”) 64.5 parts by weight, acrylonitrile monomer (hereinafter abbreviated as “AN”) 35.5 parts by weight, N, N′-4,4′-diphenylmethane bismaleimide monomer 0.025 parts by weight (hereinafter abbreviated as “BMI”), 0.02 parts by weight of benzoyl peroxide (hereinafter abbreviated as “BPO”) as a polymerization initiator, and t-dodecyl mercaptan (hereinafter abbreviated as “TDM”) as a chain transfer agent A mixed solution of 0.4 part by weight and 25 parts by weight of ethylbenzene (hereinafter abbreviated as “EB”) as a solvent was completely dissolved to obtain a raw material solution.
The above raw material solution was continuously charged into a three-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 36 kg / hour to carry out the polymerization reaction. Then, the polymer solution obtained from the first reactor was introduced into the second reactor while continuously taking out, and an additional mixed solution consisting of 100 parts by weight of SM and 0.22 parts by weight of BMI was added at a flow rate of 2 kg / hour. Then, the polymerization reaction was carried out continuously in the second reactor. The polymer solution obtained from the second reactor was continuously taken out and introduced into the third reactor, and an additional mixed solution consisting of 100 parts by weight of SM and 0.04 parts by weight of BMI was added at a flow rate of 2 kg / hour. Then, the polymerization reaction was carried out continuously in the third reactor.
The first and second reactors were completely mixed reactors (hereinafter abbreviated as “CSTR”), and the third reactor was a plug flow reactor (hereinafter abbreviated as “PFR”). The internal volume of the reactor is 40 liters, 40 liters, and 75 liters, respectively, and the reaction inlet temperature is maintained at 95 ° C, 105 ° C, and 135 ° C, respectively, and the reaction stirring speed is 120 rpm, 90 rpm, and 35 rpm, respectively. Retained.
When the conversion rate of the third reactor reaches 72% by weight, the polymer solution obtained from the third reactor is continuously taken out and introduced into a volatilizer, such as a vacuum devolatilizer or an extrusion devolatilizer. It was introduced into a volatilizer to remove unreacted monomers and volatile components, and then granulated to obtain a styrene copolymer (A-1). Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-1).

“Synthesis Example a-1: Synthesis of Styrene Copolymer (A-1-1)”
SM 64.5 parts by weight, AN 35.5 parts by weight, N, N'-4,4'-2,2-diphenylpropane bismaleimide monomer 0.025 parts by weight, BPO as a polymerization initiator 0.02 parts by weight, chain transfer agent TDM 0.4 A mixed solution of parts by weight and 25 parts by weight of EB as a solvent was completely dissolved to obtain a raw material solution.
The above raw material solution was continuously charged into a three-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 36 kg / hour to carry out the polymerization reaction. Then, the polymer solution obtained from the first reactor was continuously taken out and introduced into the second reactor, and further 100 parts by weight of SM, N, N′-4,4′-2,2-diphenylpropane bis An additional mixed solution consisting of 0.22 parts by weight of maleimide monomer was continuously charged into the second reactor at a flow rate of 2 kg / hour to carry out the polymerization reaction. Then, the polymer solution obtained from the second reactor was continuously taken out and introduced into the third reactor, and further 100 parts by weight of SM, N, N'-4,4'-2,2-diphenylpropane bis An additional mixed solution consisting of 0.04 parts by weight of maleimide monomer was continuously charged into the third reactor at a flow rate of 2 kg / hour to carry out the polymerization reaction.
The first and second reactors were completely mixed reactors (hereinafter abbreviated as “CSTR”), and the third reactor was a plug flow reactor (hereinafter abbreviated as “PFR”). The internal volume of the reactor is 40 liters, 40 liters, and 75 liters, respectively, and the reaction inlet temperature is maintained at 95 ° C, 105 ° C, and 135 ° C, respectively, and the reaction stirring speed is 120 rpm, 90 rpm, and 35 rpm, respectively. Retained.
When the conversion rate of the third reactor reaches 72% by weight, the polymer solution obtained from the third reactor is continuously taken out and introduced into a volatilizer, such as a vacuum devolatilizer or an extrusion devolatilizer. It was introduced into a volatilizer to remove unreacted monomers and volatile components, and then granulated to obtain a styrene copolymer (A-1-1). The weight average molecular weight of the styrene copolymer (A-1-1) was 89721, and the MIR value was 24.3.

“Synthesis Example a-2: Synthesis of Styrene Copolymer (A-1-2)”
SM 64.5 parts, AN 35.5 parts, N, N'-4,4'-diphenyl ether bismaleimide monomer 0.025 parts, BPO 0.02 parts as polymerization initiator, TDM 0.4 parts by weight as chain transfer agent and solvent A mixed solution of 25 parts by weight of EB was completely dissolved to obtain a raw material solution.
The above raw material solution was continuously charged into a three-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 36 kg / hour to carry out the polymerization reaction. Then, while continuously removing the polymer solution obtained from the first reactor, introduced into the second reactor, further SM 100 parts by weight, N, N'-4,4'-diphenyl ether bismaleimide monomer 0.22 The additional mixed solution consisting of parts by weight was continuously charged into the second reactor at a flow rate of 2 kg / hour to carry out the polymerization reaction. Then, while continuously taking out the polymer solution obtained from the second reactor, it was introduced into the third reactor, and further 100 parts by weight of SM, N, N′-4,4′-diphenyl ether bismaleimide monomer 0.04 The additional mixed solution consisting of parts by weight was continuously charged into the third reactor at a flow rate of 2 kg / hour to carry out the polymerization reaction.
The first and second reactors were completely mixed reactors (hereinafter abbreviated as “CSTR”), and the third reactor was a plug flow reactor (hereinafter abbreviated as “PFR”). The internal volume of the reactor is 40 liters, 40 liters, and 75 liters, respectively, and the reaction inlet temperature is maintained at 95 ° C, 105 ° C, and 135 ° C, respectively, and the reaction stirring speed is 120 rpm, 90 rpm, and 35 rpm, respectively. Retained.
When the conversion rate of the third reactor reaches 72% by weight, the polymer solution obtained from the third reactor is continuously taken out and introduced into a volatilizer, such as a vacuum devolatilizer or an extrusion devolatilizer. It was introduced into a volatilizer to remove unreacted monomers and volatile components, and then granulated to obtain a styrene copolymer (A-1-2). The weight average molecular weight of the styrene copolymer (A-1-2) was 88945, and the MIR value was 24.1.

“Synthesis Example b: Synthesis of Styrene Copolymer (A-2)”
SM 65.5 parts by weight, AN 34.5 parts by weight, BMI 0.022 parts by weight, 1,1-bis- (t-butylperoxy) -3,3,5-trimethylcyclohexane (hereinafter abbreviated as “TX-29A”) as a polymerization initiator A mixed solution of 0.01 parts by weight, 0.4 parts by weight of TDM and 25 parts by weight of EB was completely dissolved to obtain a raw material solution.
The above raw material solution was continuously charged into a three-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 37 kg / hour to carry out the polymerization reaction. Then, the polymer solution obtained from the first reactor was introduced into the second reactor while being continuously taken out, and an additional mixed solution consisting of 100 parts by weight of SM and 0.15 parts by weight of BMI was added at a flow rate of 3 kg / hour. Then, the polymerization reaction was carried out continuously in the second reactor. Then, while continuously taking out the polymer solution obtained from the second reactor, it was introduced into the third reactor to carry out the polymerization reaction.
The first and second reactors were CSTR and the third reactor was PFR. The internal volume of the reactor is 40 liters, 40 liters, and 75 liters, respectively, and the reaction inlet temperature is maintained at 95 ° C, 105 ° C, and 135 ° C, respectively, and the reaction stirring speed is 120 rpm, 90 rpm, and 35 rpm, respectively. Retained.
When the conversion rate of the third reactor reached 74% by weight, the polymer solution obtained from the third reactor was continuously taken out and introduced into the volatilizer by the same operation method as in Synthesis Example a. , Devolatilization, extrusion, granulation and the like were performed to obtain a styrene copolymer (A-2). Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-2).

“Synthesis Example c: Synthesis of Styrene Copolymer (A-3)”
SM 64.5 parts by weight, AN 35.5 parts by weight, BMI 0.007 parts by weight, 2,2-bis- (4,4-di-t-butylperoxy) cyclohexylpropane (hereinafter abbreviated as “PX-12”) as a polymerization initiator ) A mixed solution of 0.005 parts by weight, 0.4 parts by weight of TDM and 25 parts by weight of EB was completely dissolved to obtain a raw material solution.
The above raw material solution was continuously charged into a four-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 36 kg / hour to carry out the polymerization reaction. Then, while continuously taking out the polymer solution obtained from the first reactor, it was introduced into the second reactor, and an additional mixed solution consisting of 100 parts by weight of SM, 0.066 parts by weight of BMI, and 0.054 parts by weight of TX-29A. Was continuously charged into the second reactor at a flow rate of 2 kg / hour to carry out the polymerization reaction. Then, while continuously removing the polymer solution obtained from the second reactor, it was introduced into the third reactor, and an additional mixed solution consisting of 100 parts by weight of SM and 0.013 parts by weight of TX-29A was added at 2 kg / The polymerization reaction was carried out by continuously charging the third reactor at a flow rate of time. Then, while continuously taking out the polymer solution obtained from the third reactor, it was introduced into the fourth reactor to carry out the polymerization reaction.
The first and second reactors were CSTR, and the third and fourth reactors were PFR. The internal volume of the reactor is 40 liters, 40 liters, 75 liters and 75 liters, respectively, and the reaction inlet temperature is maintained at 95 ° C, 105 ° C, 130 ° C and 135 ° C, respectively, and the reaction stirring speed is 120 rpm, It was kept at 90 rpm, 38 rpm, and 35 rpm.
When the conversion rate of the fourth reactor reached 76% by weight, the polymer solution obtained from the fourth reactor was continuously taken out and introduced into the volatilizer by the same operation method as in Synthesis Example a. , Devolatilization, extrusion, granulation, and the like were performed to obtain a styrene copolymer (A-3). Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-3).

“Synthesis Example d: Synthesis of Styrene Copolymer (A-4)”
A mixed solution of 64.5 parts by weight of SM, 35.5 parts by weight of AN, 0.028 parts by weight of BMI, 0.006 parts by weight of PX-12, 0.4 parts by weight of TDM and 25 parts by weight of EB was completely dissolved to obtain a raw material solution.
The above raw material solution was continuously charged into a three-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 36 kg / hour to carry out the polymerization reaction. Then, the polymer solution obtained from the first reactor was introduced into the second reactor while continuously taking out, and an additional mixed solution consisting of 100 parts by weight of SM and 0.033 parts by weight of TX-29A was added at 2 kg / hour. The polymerization reaction was carried out by continuously charging the second reaction apparatus at a flow rate of 5%. Then, while continuously taking out the polymer solution obtained from the second reactor, it was introduced into the third reactor, and 100 parts by weight of SM was continuously fed into the third reactor at a flow rate of 2 kg / hour. A polymerization reaction was performed.
The first and second reactors were CSTR and the third reactor was PFR. The internal volume of the reactor is 40 liters, 40 liters, and 75 liters, respectively, and the reaction inlet temperature is maintained at 95 ° C, 105 ° C, and 135 ° C, respectively, and the reaction stirring speed is 120 rpm, 90 rpm, and 35 rpm, respectively. Retained.
When the conversion rate of the third reactor reached 71% by weight, the polymer solution obtained from the third reactor was continuously taken out and introduced into the volatilizer by the same operation method as in Synthesis Example a. , Devolatilization, extrusion, granulation and the like were performed to obtain a styrene copolymer (A-4). Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-4).

“Synthesis Example e: Synthesis of Styrene Copolymer (A-5)”
A mixed solution of 64.5 parts by weight of SM, 35.5 parts by weight of AN, 0.022 parts by weight of BMI, 0.02 parts by weight of BPO, 0.4 parts by weight of TDM and 25 parts by weight of EB was completely dissolved to obtain a raw material solution.
The above raw material solution was continuously charged into a three-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 36 kg / hour to carry out the polymerization reaction. Then, while continuously taking out the polymer solution obtained from the first reactor, it was introduced into the second reactor, and an additional mixed solution consisting of 100 parts by weight of SM, 0.2 parts by weight of BMI, and 0.08 parts by weight of TX-29A. Was continuously charged into the second reactor at a flow rate of 2 kg / hour to carry out the polymerization reaction. Then, while continuously taking out the polymer solution obtained from the second reactor, it was introduced into the third reactor, and 100 parts by weight of SM was continuously fed into the third reactor at a flow rate of 2 kg / hour. A polymerization reaction was performed.
The first and second reactors were CSTR and the third reactor was PFR. The internal volume of the reactor is 40 liters, 40 liters, and 75 liters, respectively, and the reaction inlet temperature is maintained at 95 ° C, 105 ° C, and 135 ° C, respectively, and the reaction stirring speed is 120 rpm, 90 rpm, and 35 rpm, respectively. Retained.
When the conversion rate of the third reactor reached 72% by weight, the polymer solution obtained from the third reactor was continuously taken out and introduced into the volatilizer by the same operation method as in Synthesis Example a. , Devolatilization, extrusion, granulation and the like were performed to obtain a styrene copolymer (A-5). Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-5).

“Synthesis Example f: Synthesis of Styrene Copolymer (A-6)”
In the raw material solution, the same procedure as in Synthesis Example b except that the composition of the monomer was 60 parts by weight of SM, 34 parts by weight of AN, 6 parts by weight of methyl methacrylate (abbreviated as MMA), and 0.022 parts by weight of BMI. It was manufactured by the method. The conversion of the final third reactor was 74% by weight. Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-6).

“Synthesis Example g: Synthesis of Styrene Copolymer (A-7)”
The raw material solution was prepared in the same manner as in Synthesis Example b except that the monomer composition was 61 parts by weight of SM, 39 parts by weight of AN, 0.022 part by weight of BMI and 0.5 part by weight of TDM. The conversion of the final third reactor was 72% by weight. Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-7).

“Synthesis Example h: Synthesis of Styrene Copolymer (A-8)”
In the raw material solution, the second reactor was composed of 73 parts by weight of SM, 27 parts by weight of AN, 0.066 part by weight of BMI, 0.01 part by weight of TX-29A, 0.3 part by weight of TDM, and 25 parts by weight of EB. An additional mixed solution was prepared in the same manner as in Synthesis Example b, except that the monomer composition was 100 parts by weight of SM and 0.45 parts by weight of BMI. The conversion of the final third reactor was 73% by weight. Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-8).

“Comparative Synthesis Example i : Synthesis of Styrene Copolymer (A-9)”
A mixed solution of 68 parts by weight of SM, 32 parts by weight of AN, 0.02 part by weight of BPO, 0.4 part by weight of TDM and 25 parts by weight of EB was completely dissolved to obtain a raw material solution.
The above raw material solution was continuously charged into a two-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 40 kg / hour to carry out the polymerization reaction. Then, a polymer solution obtained from the first reactor was introduced into the second reactor while continuously taking out, and a polymerization reaction was performed.
The first and second reactors were CSTR. The internal volume of the reactor was 40 liters and 40 liters, respectively, the reaction inlet temperature was kept at 100 ° C. and 120 ° C., and the reaction stirring speed was kept at 120 rpm and 90 rpm, respectively.
When the conversion rate of the second reactor reached 52% by weight, the polymer solution obtained from the second reactor was continuously taken out and introduced into the volatilizer by the same operation method as in Synthesis Example a. , Devolatilization, extrusion, granulation and the like were performed to obtain a styrene copolymer (A-9). Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-9).

“Comparative Synthesis Example j: Synthesis of Styrene Copolymer (A-10)”
The raw material solution was prepared by the same operation method as in Synthesis Example i, except that 0.01 part by weight of BMI was added as the monomer composition. The conversion of the final second reactor was 53% by weight. Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-10).

“Comparative Synthesis Example k: Synthesis of Styrene Copolymer (A-11)”
In the raw material solution, 0.035 parts by weight of divinylbenzene (hereinafter abbreviated as “DVB”) was added as the monomer composition, and the amount of TDM used was changed to 0.5 parts by weight. Manufactured by operating method. The conversion of the final second reactor was 54% by weight. Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-11).

“Comparative Synthesis Example l: Synthesis of Styrene Copolymer (A-12)”
The raw material solution was produced by the same operation method as in Synthesis example b, except that the amount of TDM used was changed to 0.6 parts by weight. The conversion of the final third reactor was 72% by weight. Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-12).

“Comparative Synthesis Example m: Synthesis of Styrene Copolymer (A-13)”
The raw material solution was produced by the same operation method as in Synthesis Example b, except that the amount of TDM used was changed to 0.1 parts by weight. The conversion of the final third reactor was 73% by weight. Table 1 shows the reaction conditions and analysis results in the production of the styrene copolymer (A-13).

R1,R2： 完全混合式反応装置（CSTR）
R3,R4：プラグフロー反応装置（PFR）
SM：スチレン単量体
AN：アクリロニトリル単量体
MMA：メタクリル酸メチル単量体
BMI：N,N'-4,4'-ジフェニルメタンビスマレイミド単量体
DVB：ジビニルベンゼン
BPO：ベンゾイルパーオキサイド
TX-29A：1,1−ビス−（t−ブチルパーオキシ）−3,3,5−トリメチルシクロヘキサン
PX-12：2,2−ビス−（4,4−ジ−t−ブチルパーオキシ）シクロヘキシルプロパン
TDM：t-ドデシルメルカプタン
EB：エチルベンゼン “Comparative Synthesis Example n: Synthesis of Styrene Copolymer (A-14)”
In the raw material solution, except that BMI was changed to 1.5 parts by weight as the monomer composition, the same operation as in Synthesis Example i was performed, but the viscosity of the reaction system was excessively increased and the hue of the reaction product was deteriorated. At the same time, contamination and cross-linking foreign matters increased, and eventually polymerization could not be continued. The polymer obtained from the second reactor was taken out and the melt flow index was measured. As a result, the MIR value was 32.5.

R1, R2: Completely mixed reactor (CSTR)
R3, R4: Plug flow reactor (PFR)
SM: Styrene monomer
AN: Acrylonitrile monomer
MMA: Methyl methacrylate monomer
BMI: N, N'-4,4'-diphenylmethane bismaleimide monomer
DVB: Divinylbenzene
BPO: Benzoyl peroxide
TX-29A: 1,1-bis- (t-butylperoxy) -3,3,5-trimethylcyclohexane
PX-12: 2,2-bis- (4,4-di-t-butylperoxy) cyclohexylpropane
TDM: t-dodecyl mercaptan
EB: Ethylbenzene

<Synthesis Example of Rubber-like Graft Copolymer (B ′)>
“Synthesis Example of Rubber-like Graft Copolymer (B′-1)”
A mixed solution of 68 parts by weight of SM, 32 parts by weight of AN, 7 parts by weight of butadiene rubber (abbreviated as BD), 0.03 part by weight of BPO, 0.3 part by weight of TDM and 35 parts by weight of EB was completely dissolved to obtain a raw material solution.
The above raw material solution was continuously charged into a four-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 40 kg / hour to carry out the polymerization reaction. Then, a polymer solution obtained from the first reactor was introduced into the second reactor while continuously taking out, and a polymerization reaction was performed. Then, while continuously taking out the polymer solution obtained from the second reactor, it was introduced into the third reactor to carry out the polymerization reaction. Then, while continuously taking out the polymer solution obtained from the third reactor, it was introduced into the fourth reactor to carry out the polymerization reaction.
The first through fourth reactors were CSTR. The internal volume of the reactor is 40 liters, the reaction inlet temperature is maintained at 100 ° C, 105 ° C, 115 ° C, and 130 ° C, respectively, and the reaction agitation speed is 300 rpm, 200 rpm, 150 rpm, and 90 rpm, respectively. Retained.
When the conversion rate of the fourth reactor reached 65% by weight, the polymer solution obtained from the fourth reactor was continuously taken out and introduced into the volatilizer by the same operation method as in Synthesis Example a. , Devolatilization, extrusion, granulation, and the like were performed to obtain a rubber-like graft copolymer (B′-1). Its rubber content was 10% by weight.

"Synthesis example of rubber graft copolymer (B'-2)"
Synthetic rubber latex having a conversion rate of 94%, a solid content of about 36%, and a weight average particle size of about 0.1 μm is reacted for 14 hours at a temperature of 65 ° C. according to the formulation of each component in Table 2. Obtained.

On the other hand, carboxyl group-containing polymer flocculants were produced from the components shown in Table 3. That is, the reaction was carried out for 5 hours at a temperature of 75 ° C. according to the formulation of each component in Table 3, and a latex of a polymer flocculant containing a carboxyl group having a conversion rate of about 95% and a pH of 6.0 was obtained.

Next, 3 parts by weight (as a solid content) of the polymer flocculant containing the carboxyl group is added to 100 parts by weight (as a solid content) of the synthetic rubber latex to increase the pH to 8.5 and the rubber particle size to 0.31 μm. A rubber latex was obtained. Next, styrene and acrylonitrile monomers were graft polymerized with the enlarged rubber latex according to the formulation of each component in Table 4 to produce a rubber-like graft copolymer.

  The rubber-like graft copolymer latex obtained by the above blending is solidified using calcium chloride, dehydrated, and further dried until the water content is 2% by weight or less, the rubber content is 50% by weight, A rubber-like graft copolymer (B′-2) having a rubber weight average particle size of 0.31 μm was obtained.

<Examples and comparative examples of rubber-modified styrenic resin compositions>
[Simultaneous grafting method]
"Example 1"
65.5 parts by weight of SM, 34.5 parts by weight of AN, 8.0 parts by weight of BD, 0.022 parts by weight of BMI, 0.04 parts by weight of TX-29A, 0.4 parts by weight of TDM, and butyl stearate as a plasticizer (hereinafter abbreviated as “BS”) A mixed solution of 5 parts by weight and 35 parts by weight of EB was completely dissolved to obtain a raw material solution.
The above raw material solution was continuously charged into a four-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 37 kg / hour to carry out the polymerization reaction. Then, the polymer solution obtained from the first reactor was introduced into the second reactor while being continuously taken out, and an additional mixed solution consisting of 100 parts by weight of SM and 0.15 parts by weight of BMI was added at a flow rate of 3 kg / hour. Then, the polymerization reaction was carried out continuously in the second reactor. Then, while continuously taking out the polymer solution obtained from the second reactor, it was introduced into the third reactor to carry out the polymerization reaction. Then, while continuously taking out the polymer solution obtained from the third reactor, it was introduced into the fourth reactor to carry out the polymerization reaction.
The first and second reactors were CSTR, and the third and fourth reactors were PFR. The reactor internal volumes are 40 liters, 40 liters, 75 liters and 75 liters, respectively, and the reaction inlet temperatures are maintained at 100 ° C, 105 ° C, 115 ° C and 130 ° C, respectively, and the reaction stirring speed is 300 rpm, It was kept at 200 rpm, 150 rpm, and 90 rpm.
When the conversion rate of the fourth reactor reached 75% by weight, the polymer solution obtained from the fourth reactor was continuously taken out and introduced into the volatilizer by the same operation method as in Synthesis Example a. , Devolatilization, extrusion, granulation and the like were performed to obtain a rubber-modified styrene resin composition. Its rubber content was 10% by weight. The obtained rubber-modified styrenic resin composition was dissolved in a tetrahydrofuran solution, the continuous phase of the styrene copolymer (A) was taken out, and the melt flow index was measured. As a result, the weight average molecular weight of the continuous phase was 103,711. The MIR was 24.2. Table 5 shows the reaction conditions and analysis results in the production of the rubber-modified styrene resin composition.

"Comparative Example 1"
Completely dissolves a mixed solution of SM 68 parts, 32 parts AN, 8.0 parts BD, 0.0002 parts BMI, 0.04 parts TX-29A, 0.4 parts TDM, 1.5 parts BS and 35 parts EB. To obtain a raw material solution.
The above raw material solution was continuously charged into a four-tank series reactor. That is, the raw material solution was continuously charged into the first reactor at a flow rate of 40 kg / hour to carry out the polymerization reaction. Then, while continuously taking out the polymer solution obtained from the first reactor, it was introduced into the second reactor to carry out the polymerization reaction. Then, while continuously taking out the polymer solution obtained from the second reactor, it was introduced into the third reactor to carry out the polymerization reaction. Then, while continuously taking out the polymer solution obtained from the third reactor, it was introduced into the fourth reactor to carry out the polymerization reaction.
The first and second reactors were CSTR, and the third and fourth reactors were PFR. The reactor internal volumes are 40 liters, 40 liters, 75 liters and 75 liters, respectively, and the reaction inlet temperatures are maintained at 100 ° C, 105 ° C, 115 ° C and 130 ° C, respectively, and the reaction stirring speed is 300 rpm, It was kept at 200 rpm, 150 rpm, and 90 rpm.

R1,R2： 完全混合式反応装置（CSTR）
R3,R4：プラグフロー反応装置（PFR）
SM：スチレン単量体
AN：アクリロニトリル単量体
BD：ブタジエンゴム
BMI：N,N'-4,4'-ジフェニルメタンビスマレイミド単量体
TX-29A：1,1−ビス−（t−ブチルパーオキシ）−3,3,5−トリメチルシクロヘキサン
TDM：t-ドデシルメルカプタン
EB：エチルベンゼン When the conversion rate of the fourth reactor reached 74% by weight, the polymer solution obtained from the fourth reactor was continuously taken out and introduced into the volatilizer by the same operation method as in Synthesis Example a. , Devolatilization, extrusion, granulation and the like were performed to obtain a rubber-modified styrene resin composition. Its rubber content was 10.3% by weight. The obtained rubber-modified styrenic resin composition was dissolved in a tetrahydrofuran solution, the continuous phase of the styrene copolymer (A) was taken out, and the melt flow index was measured. As a result, the weight average molecular weight of the continuous phase was 101,224. The MIR was 21.1. Table 5 shows the reaction conditions and analysis results in the production of the rubber-modified styrene resin composition.

R1, R2: Completely mixed reactor (CSTR)
R3, R4: Plug flow reactor (PFR)
SM: Styrene monomer
AN: Acrylonitrile monomer
BD: Butadiene rubber
BMI: N, N'-4,4'-diphenylmethane bismaleimide monomer
TX-29A: 1,1-bis- (t-butylperoxy) -3,3,5-trimethylcyclohexane
TDM: t-dodecyl mercaptan
EB: Ethylbenzene

[Graft kneading method]
"Example 2"
20 parts by weight of rubbery graft copolymer (B'-1), 30 parts by weight of rubbery graft copolymer (B'-2), 50 parts by weight of styrene copolymer (A-1) and N, N ' -0.3 parts by weight of ethylene bis (stearylamide) (hereinafter abbreviated as "EBS") was dry blended with a Henschel mixer, and the cylinder temperature was set to 200 to 220 ° C and the die adapter temperature was set to 220 ° C. The mixture was melt-kneaded using a twin-screw extruder to obtain a pellet-like rubber-modified styrene resin composition. Its rubber content was 17% by weight. Table 6 shows the composition of the rubber-modified styrenic resin composition, extrusion conditions, and physical property analysis results.

"Example 2-1"
Pellets were processed under the same extrusion conditions as in Example 2 except that 50 parts by weight of styrene copolymer (A-1-1) was used instead of styrene copolymer (A-1). A rubber-modified styrene resin composition was obtained. The rubber-modified styrenic resin composition had a rubber content of 17% by weight, an impact strength of 19.2 kg-cm / cm, and evaluation of fluidity, environmental stress crack resistance and contamination were all good.

"Example 2-2"
The pellets were processed under the same extrusion conditions as in Example 2 except that 50 parts by weight of the styrene copolymer (A-1-2) was used instead of the styrene copolymer (A-1). A rubber-modified styrene resin composition was obtained. The rubber-modified styrenic resin composition had a rubber content of 17% by weight, an impact strength of 18.8 kg-cm / cm, and the evaluation of fluidity, environmental stress crack resistance and contamination were all good.

"Example 3"
30 parts by weight of rubber-like graft copolymer (B'-2), 20 parts by weight of the rubber-modified styrene resin composition obtained in Example 1, 50 parts by weight of styrene copolymer (A-2) and 0.3 parts by weight of EBS The part was processed under the same extrusion conditions as in Example 2 to obtain a pellet-like rubber-modified styrene resin composition. Its rubber content was 17% by weight. Table 6 shows the composition of the rubber-modified styrenic resin composition, extrusion conditions, and physical property analysis results.

Example 4
A rubber-like graft copolymer (B'-2) 34 parts by weight, a styrene copolymer (A-1) 66 parts by weight and EBS 0.3 parts by weight were processed under the same extrusion conditions as in Example 2 to produce pellets. A rubber-modified styrene resin composition was obtained. Its rubber content was 17% by weight. Table 6 shows the composition of the rubber-modified styrenic resin composition, extrusion conditions, and physical property analysis results.

"Examples 5 to 11"
The styrenic copolymer (A) was produced by the same operation method as in Example 4 except that the type and amount of use were adjusted. Table 6 shows the composition, extrusion conditions, and physical property analysis results of the obtained rubber-modified styrene resin compositions.

"Comparative Example 2"
It manufactured by the same operation method as Example 2 except having adjusted the kind of styrene-type copolymer (A). Table 6 shows the composition of the rubber-modified styrenic resin composition, extrusion conditions, and physical property analysis results.

"Comparative Examples 3-7"
The styrenic copolymer (A) was produced by the same operation method as in Example 4 except that the type and amount of use were adjusted. Table 6 shows the composition, extrusion conditions, and physical property analysis results of the obtained rubber-modified styrene resin compositions.

<Physical property evaluation method>
1. MIR
MIR is the ratio of HMI to MI (HMI / MI), where HMI is the MFR at 10 kg load at 200 ° C (g / 10 min) and MI is the MFR at 1 kg load at 200 ° C (g / 10 Min). (MFR refers to the melt flow index, which can be measured by the ASTM D-1238 method.)

2. Weight average molecular weight The above styrene copolymer (A) was dissolved in a tetrahydrofuran solution and subjected to measurement analysis using gel permeation chromatography (GPC, manufactured by Waters). Polystyrene was used as a standard during the analysis. The GPC analysis conditions are as follows.
Column: KD-806M
Detector: Water RI-2410
Mobile phase: THF (flow rate 1.0 / min)

3. Rubber content
Measurement is performed using a Fourier transform infrared spectrometer manufactured by Nicolet (series number: Nexus 470). (Unit:% by weight)

4). Shock resistance
Measured by ASTM D-256 (notched, 1/4 inch thickness, unit: kg-cm / cm).

5). Flowability The rubber-modified styrenic resin composition was molded using a spiral flow mold (2 mmt) at a cylinder temperature of 200 ° C., a mold temperature of 50 ° C., and an injection pressure of 1000 kg / cm ² with an Seioo SM90 injection molding machine, The fluidity was evaluated by the flow length. (Unit: mm)
○: 230 mm or more Δ: 215 or more and less than 230 mm ×: less than 215 mm

6). Environmental stress crack resistance 100 mm x 12.7 mm x 3 mm test piece is fixed on a 1/4 oval jig with a radius of curvature of 165 mm and immersed in a 30% alcohol solution. evaluate.
○: 48 hours or more.
Δ: 24 hours or more and less than 48 hours.
X: Less than 24 hours.

7). Contamination Take 10 g of the flame-retardant styrene resin composition, use a hot press to produce a circular film with a diameter of 200 mm and a thickness of 0.3 mm, and observe the number of contaminations on the film. Here, the contamination in the present invention is usually a discolored and difficult-to-melt material that occurs in the process of making the resin composition of the present invention, and the main components thereof are a styrene monomer and a vinyl cyanide monomer. The body is polymerized and has a small lump shape.
○: 0 to 1 point △: 2 to 4 points ×: 5 points or more

Claims (4)

(i-1) 50 to 90 parts by weight of styrene monomer, (i-2) 10 to 50 parts by weight of vinyl cyanide monomer, and (i-3) other copolymerizable vinyl monomers 0-22 parts by weight (these total 100 parts by weight), the (i-1), (i -2) and the total per 100 parts by weight, monofunctional maleimide monomer of (i-3) A styrene-based copolymer (A) obtained by copolymerizing 0.0005 to 0.3 parts by weight of a polyfunctional maleimide monomer without using a body is used as a continuous phase, and rubber particles (B) made of a diene rubber are used as a dispersed phase. A rubber-modified styrenic resin composition,
The rubber content in the rubber-modified styrenic resin composition is 1 to 40% by weight, and the styrene copolymer (A) has an MIR calculated from the following formula of 21.5 to 30.0, and its weight average molecular weight. A rubber-modified styrenic resin composition having a molecular weight of 60,000 to 145,000.
MIR = HMI / MI
HMI: MFR at 10 kg load at 200 ° C (g / 10 min) measured by ASTM D-1238 method
MI: MFR at 1 kg load at 200 ° C. measured by ASTM D-1238 method (g / 10 min) The content ratio of the (i-2) vinyl cyanide monomer in (i-1), (i-2) and (i-3) in a total of 100 parts by weight is 20 to 42 parts by weight. 2. The rubber-modified styrenic resin composition according to 1. The polyfunctional maleimide monomer is N, N′-4,4 ′-(3,3′-dimethyldiphenylmethane) bismaleimide, N, N′-4,4 ′-(3,3′-diethyl Diphenylmethane) bismaleimide, N, N'-4,4'-diphenylmethane bismaleimide, N, N'-4,4'-2,2-diphenylpropane bismaleimide, N, N'-4,4'-diphenyl ether bis Maleimide, N, N'-3,3'-diphenylsulfone bismaleimide, N, N'-4,4'-diphenylsulfone bismaleimide, N, N'-4,4'-diphenylsulfoxide bismaleimide, N, N 3. The method according to claim 1, wherein the selected material is selected from '-4,4'-benzophenone bismaleimide, bis (4-maleimidophenyloxyphenyl) 2,2-propane, and N, N'-1,3-phenylenebismaleimide. A rubber-modified styrene-based resin composition. The rubber-modified styrene resin composition according to claim 1 or 2, wherein the diene rubber is selected from butadiene rubber, styrene-diene rubber, and acrylonitrile-diene rubber.