JP2005082717A - Polystyrene resin composition for plastic card - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a rubber modified styrene resin composition for a plastic card which markedly improves heat stability, mold staining resistance, flexing resistance, adhesion properties to an IC (integrated circuit) chip in injection molding at a high temperature while holding excellence in impact resistance, rigidity, and heat strength resistance. <P>SOLUTION: This rubber modified styrene resin composition for the plastic card is obtained by compounding, per 100 pts.wt. of a rubber modified styrene resin comprising 5-95 wt% of a rubber-like graft copolymer (I) obtained by polymerizing a styrene monomer and an acrylonitrile monomer in the presence of a rubber by using an emulsion polymerization process, and 95-5 wt% of another rubber-like graft copolymer (II) obtained by polymerizing the monomers in the presence of the rubber by using a bulk polymerization process and/or a solution polymerization process, 2-35 pts.wt. of a methacrylate polymer (IV) therewith, wherein the rubber-like graft copolymer (I) contains rubber particles of two peaked particle diameter distribution having a weight-average particle diameter of 0.05-0.18 μm and 0.2-1.0 μm, and the rubber-like graft copolymer (II) contains rubber particles having the weight-average particle diameter of 0.5-10 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rubber-modified styrenic resin composition used for plastic cards (for example, IC cards), and in particular, while maintaining good impact resistance, rigidity and heat resistance strength, thermal stability, moldability and mold resistance. The present invention relates to a rubber-modified styrenic resin composition for plastic cards, which has greatly improved contamination, bending resistance (bending strength), and adhesion to an IC chip.

  An IC card is obtained by providing an IC chip on a plastic card, thereby giving the card various functions such as storage, identification, confidentiality or release, and information transmission. As a material for the plastic card, a polyvinyl chloride resin (for example, PVC) is generally used. Polyvinyl chloride resin is advantageous in price and has good thin-wall molding processability. In addition, in order to improve impact resistance and flexibility, impact resistance can be easily improved by adding methyl methacrylate-butadiene-styrene copolymer, ethylene-vinyl acetate copolymer, etc. to polyvinyl chloride resin. Because of its flexibility, it has been used as a material for plastic cards. However, the polyvinyl chloride resin has disadvantages such as poor thermal stability during molding, insufficient impact resistance at low temperatures, and difficulty in recycling.

  Conventionally, rubber-modified styrenic resins have a certain impact resistance and are widely applied to various resin molding fields in combination with the ease of molding. However, when applied to an IC card, since the card itself is extremely thin, it must be injection-molded at a high temperature and must have good product strength. Specifically, when rubber-modified styrenic resin is applied to an IC card, for example, there is a problem of poor thermal stability of the resin and mold contamination in high temperature injection molding, insufficient bending strength of a thin IC card, and an IC chip. Problems such as poor adhesion to cards made of rubber-modified styrene resin must be overcome. In particular, improvement in adhesion is important because poor adhesion is only related to reliability in use of an IC card.

  A rubber-modified styrene resin composition that overcomes the disadvantages of the above-mentioned polyvinyl chloride resin as a card material and has various properties required for plastic cards (especially IC cards), specifically, good impact resistance Rubber modified styrenic resin composition with significantly improved thermal stability, mold fouling resistance, bending resistance, and adhesion to IC chips in high-temperature injection molding while maintaining its properties, rigidity and heat resistance To do.

  The present invention was made as a result of intensive studies to solve the above conventional problems, and the rubber-modified styrenic resin composition of the present invention maintains good impact resistance, rigidity and heat resistance strength. On the other hand, the thermal stability, mold contamination resistance, bending resistance, and adhesion to the IC chip in high temperature injection molding are greatly improved.

In order to achieve the above required performance, the rubber-modified styrenic resin composition for plastic cards of the present invention comprises the following components.
5 to 95% by weight of a rubber-like graft copolymer (I) obtained by polymerizing a styrene monomer and an acrylonitrile monomer in the presence of rubber by an emulsion polymerization method, and a styrene monomer in the presence of rubber. 95 to 5% by weight of a rubber-like graft copolymer (II) obtained by polymerizing a monomer and an acrylonitrile monomer by a bulk and / or solution polymerization method, a styrene monomer, an acrylonitrile monomer, and A methacrylate-based polymer is used for 100 parts by weight of a rubber-modified styrene resin composed of 0 to 70% by weight of a copolymer (III) obtained by polymerizing other monomers copolymerizable with these as required. The rubber-like graft copolymer (I) has 2 to 35 parts by weight of the coalescence (IV), and the rubbery graft copolymer (I) has rubber particles having a bimodal particle size distribution of 0.05 to 0.18 μm and 0.2 to 1.0 μm. The rubbery graft copolymer (II) has a weight average particle size of 0.5 to 10 μm. Is a rubber-modified styrenic resin composition for plastic cards with a beam particle.

  Rubber-modified styrene series for plastic cards with good mechanical properties, high heat resistance, excellent thermal stability in high-temperature injection molding, and improved resistance to mold contamination due to the composition of the above specific resin components A resin composition is obtained.

  The resin composition of the present invention also has characteristic properties required particularly for IC cards in addition to the above improved properties. For example, when a cyanoacrylate-based adhesive is used, a high bonding ability is exhibited, and as a result, bonding processing between a plastic card and an IC chip becomes easy.

  Further, since the rubber-modified styrene resin composition of the present invention has excellent mold-contamination resistance, the effect of corrosion of the IC chip due to contaminants on the mold surface is small, and the IC chip is fitted into the IC card. Excellent workability. At the same time, it has good bending resistance (excellent in repeated bending tests) and satisfies important characteristics required for IC card products.

  The rubber-like graft copolymer (I) used in the present invention can be composed of a graft copolymer (A) and a graft copolymer (B). The weight ratio ((A) / (B)) of the graft copolymer (A) is preferably 5/95 to 95/5. Such a graft copolymer (A) contains 50 to 85% by weight of a styrene monomer, 50 to 15% by weight of an acrylonitrile monomer, and other copolymerizable with these in the presence of an enlarged rubber latex. Obtained by graft polymerization of 0 to 40% by weight of the above monomer (the remainder of the styrene-based monomer and acrylonitrile-based monomer in the total amount of 100% by weight of the graft copolymer (A)). . On the other hand, the graft copolymer (B) contains 50 to 85% by weight of a styrene monomer, 50 to 15% by weight of an acrylonitrile monomer, and other copolymerizable with these in the presence of an unextended rubber latex. Obtained by graft polymerization of 0 to 40% by weight of the above monomer (the balance of the styrene monomer and the acrylonitrile monomer in the total amount of the graft copolymer (B) of 100% by weight). .

  The rubber used in the rubber-like graft copolymer (I), more specifically, the rubber latex used in the production of the graft copolymers (A) and (B) has a glass transition temperature of 0 ° C. or lower. This refers to rubber polymer latex. Examples of such rubber polymers include diene rubbers (for example, polybutadiene, polyisoprene, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, styrene-isoprene copolymers), ethylene-propylene copolymers (for example, Ethylene-propylene-diene copolymer), polysilicon rubber, and acrylate rubber. Two or more of the above rubbers can be used in combination. Of these, the use of diene rubber is preferred.

  The rubber latex for the graft copolymer (A) can be obtained by emulsion polymerization. For example, in the case of using a diene rubber, the latex is a polymerization of a diene monomer alone or another monomer copolymerizable therewith (for example, a styrene monomer, an acrylonitrile monomer, etc.) (5 The diene-based synthetic rubber latex having a small particle diameter of 0.05 to 0.18 μm is obtained by reacting at a reaction temperature of ˜90 ° C. for 1 to 76 hours, and this small particle-sized diene-based synthetic rubber latex is frozen. By enlargement using the enlargement method, mechanical enlargement method, or chemical enlargement method, an enlarged rubber latex having a weight average particle diameter of 0.2 to 1.0 μm can be obtained. The enlargement of the small particle size diene synthetic rubber latex in the chemical enlargement method is, for example, 0.5 to 10 parts by weight of the polymer flocculant (solid content) with respect to 100 parts by weight of the small particle size diene synthetic rubber latex. It can be carried out by blending and stirring and mixing at room temperature. Additives that can be used in the chemical enlargement method include acidic substances such as acetic anhydride, hydrogen chloride and sulfuric acid, or inorganic salts such as sodium chloride, potassium chloride and calcium chloride, and methacrylic acid-methacrylate copolymers ( Examples thereof include carboxylic acid group-containing polymer flocculants such as methacrylic acid-butyl acrylate copolymer and methacrylic acid-ethyl acrylate copolymer). Of these, carboxylic acid group-containing polymer flocculants are preferred.

  Further, the rubber latex for the graft copolymer (B) can be obtained by emulsion polymerization, preferably by polymerizing a diene monomer and another monomer copolymerizable therewith, to obtain a weight average. A diene rubber latex having a particle size of 0.05 to 0.18 μm can be obtained.

  The rubbery graft copolymer (I) used in the present invention is composed of 100 parts by weight (solid content) of the rubber latex and 2 to 200 parts by weight of styrene monomer or acrylonitrile monomer. And a monomer mixture composed of other monomers copolymerizable therewith, and an appropriate emulsifier and an initiator are blended to carry out graft polymerization. Examples of the initiator include general ones such as dibenzoyl peroxide, diisopropylbenzene hydroperoxide, t-butyl peroxide, cumene hydroperoxide, and potassium persulfate.

  The graft ratio of the rubber-like graft copolymer (I) used in the present invention can be controlled by the polymerization conditions. For example, the grafting rate of the rubber-like graft copolymer (I) can be controlled by adjusting the polymerization temperature, the amount and type of initiator, emulsifier and chain transfer agent, the method of adding the monomer, and the like. A molecular weight of the rubber-like graft copolymer (I) can be adjusted by adding a chain transfer agent. Examples of such chain transfer agents include n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan and the like. The molecular weight of the rubber-like graft copolymer (I) can also be adjusted by the polymerization conditions such as the polymerization temperature, the type and amount of initiator used, and the method for adding the monomer. The reaction temperature of the graft polymerization is 90 ° C. or lower, preferably 30 to 80 ° C. On the other hand, the grafting monomer can obtain the rubber-like graft copolymer (I) by batch feed, sequential feed, or continuous feed.

  Styrene monomers used in the rubbery graft copolymer (I) include styrene, α-methylstyrene, α-chlorostyrene, p-t-butylstyrene, p-methylstyrene, o-chlorostyrene, Examples include p-chlorostyrene, 2,5-dichlorostyrene, 3,4-dichlorostyrene, 2,4,6-tribromostyrene, 2,5-dibromostyrene, and among them, styrene or α-methylstyrene is preferable. .

  Examples of the acrylonitrile monomer include acrylonitrile and α-methylacrylonitrile. Examples of other copolymerizable monomers used in the rubbery graft copolymer (I) include (meth) acrylic acid ester monomers, maleimide monomers, (meth) acrylic acid, and maleic anhydride. It is done. Among these, (meth) acrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, benzyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, 2-hydroxy methacrylate Examples thereof include ethyl, glyceryl methacrylate, and dimethylaminoethyl methacrylate. Among them, methyl methacrylate is preferable.

  Maleimide monomers include maleimide, N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide, N-octylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-2, 3-dimethylphenylmaleimide, N-2,4-dimethylphenylmaleimide, N-2,3-ethylphenylmaleimide, N-2,4-ethylphenylmaleimide, N-2,3-dibutylphenylmaleimide, N-2, 4-dibutylphenylmaleimide, N-2,6-dimethylphenylmaleimide, N-2,3-dichlorophenylmaleimide, N-2,4-dichlorophenylmaleimide, N-2,3-dibromophenylmaleimide, N-2,4 -Dibromophenylmaleimide and the like can be mentioned, among which N-phenylmaleimide is more preferable.

  In this invention, when manufacturing rubber-like graft copolymer (I), a graft copolymer (A) and a graft copolymer (B) can be separately sent to a mixer and mixed. The mixing ratio is preferably (A) / (B) = 5 to 95/95 to 5 (weight ratio). The rubber-like graft copolymer (I) necessary for the present invention can be obtained after the steps of condensation, dehydration and drying. The rubber-like graft copolymer (I) thus produced has a bimodal particle size distribution with rubber weight average particle sizes of 0.5 to 0.18 μm and 0.2 to 1.0 μm.

  The amount of the rubbery graft copolymer (I) used in the present invention is 5 to 95% by weight in the total of the copolymers (I) to (III), preferably 8 to 70% by weight, Most preferably, it is 10-50 weight. When the amount of the rubber-like graft copolymer (I) used is less than 5% by weight, the fluidity and impact strength of the rubber-modified styrene resin composition for plastic cards to be produced are both lowered, and the bending resistance is also a little. At the same time, the tensile strength becomes insufficient, and a whitening phenomenon (a phenomenon in which the bent portion becomes white) is likely to occur due to repeated bending tests. On the other hand, when the amount used exceeds 95% by weight, the fluidity, thermal stability, mold contamination resistance and bending resistance of the rubber-modified styrenic resin composition for plastic cards to be produced are deteriorated.

  The rubbery graft copolymer (II) used in the present invention can be obtained by polymerizing by a bulk and / or solution polymerization method. Specifically, 85 to 50% by weight of styrene monomer, 15 to 50% by weight of acrylonitrile monomer, and 0 to 40% by weight of other monomers copolymerizable with these (rubber-like graft copolymer ( It is obtained by graft polymerization of 100 parts by weight of the total amount of styrene monomer and acrylonitrile monomer) and 2 to 25 parts by weight of diene rubber. This is a method in which a diene rubber is dissolved in a monomer and / or a solvent in advance and sent to a reaction vessel by a pump for graft polymerization. The reaction tank is usually composed of 2 to several combinations, and the use of a kettle type reaction tank equipped with a powerful stirrer is most preferable. Monomer and diene rubber are mixed in a uniform state and polymerized in a continuous manner. In addition, the molecular weight can be controlled by adding the chain transfer agent (for example, t-dodecyl mercaptan) appropriately during the reaction.

  The diene rubber used in the rubber-like graft polymer (II) is obtained by polymerizing by a bulk polymerization method and / or a solution polymerization method or an emulsion polymerization method with a conjugated diene monomer as a main component. Examples of the diene rubber include butadiene rubber, isoprene rubber, chlorobutadiene rubber, styrene-butadiene copolymer rubber, and acrylonitrile-butadiene copolymer rubber. Among these, butadiene rubber includes high cis type rubber and low cis type rubber. The microstructure of high cis butadiene rubber is generally 90-98% / 1-5% / 1 in composition ratio of cis-1,4 polymer / 1,2-vinyl polymer / trans-1,4 polymer ~ 5%. The Mooney viscosity is preferably 20 to 120, and the molecular weight range is preferably 100,000 to 800,000. On the other hand, the low cis-type butadiene rubber generally has a microstructure of cis-1,4 polymer / 1,2-vinyl polymer of 20-40% / 1-20%, and the rest is trans-1,4 It is a polymer. The Mooney viscosity is preferably 20 to 120. The styrene-butadiene copolymer rubber includes block copolymers (for example, diblock copolymers and triblock copolymers) and random copolymers. In the styrene-butadiene copolymer rubber, the preferred styrene / butadiene weight ratio is 5/95 to 80/20, and the preferred molecular weight range is 50,000 to 600,000. The molecular structure of the diene rubber is linear or branched (eg, star). Diene rubbers suitable for the rubber-like graft copolymer (II) of the present invention are butadiene rubber and styrene-butadiene copolymer.

  The styrene-based monomer, acrylonitrile-based monomer, and other monomers copolymerizable with these used in the production of the rubber-like graft copolymer (II) are the rubber-like graft copolymer (I ), The detailed description thereof is omitted here.

  The weight average particle diameter of the rubber particles of the rubber-like graft copolymer (II) obtained by the bulk and / or solution polymerization method is 0.5 to 10 μm, preferably 0.8 to 7 μm.

  The amount of the rubbery graft copolymer (II) used is 5 to 95% by weight in the total of the copolymers (I) to (III), preferably 8 to 90% by weight, most preferably 10%. ~ 88 wt%. When the amount of the rubber-like graft copolymer (II) used is less than 5% by weight, the thermal stability, mold contamination resistance, and flex resistance of the rubber-modified styrene resin composition for plastic cards to be produced are all Deteriorate. On the other hand, when the amount used exceeds 95% by weight, the fluidity, impact strength and tensile strength of the rubber-modified styrene resin composition for plastic card to be produced are all lowered, and whitening due to repeated bending tends to occur.

  The copolymer (III) used in the present invention comprises 85 to 50% by weight of a styrene monomer, 15 to 50% by weight of an acrylonitrile monomer, and other monomers that can be copolymerized with these monomers 0 to It is obtained by polymerizing 40% by weight. The styrene-based monomer, acrylonitrile-based monomer and other monomers copolymerizable with these used in the production of the copolymer (III) are produced as the rubber-like graft copolymer (I). Therefore, detailed description thereof is omitted here. The copolymer (III) can be obtained by a bulk, solution, suspension, or emulsion polymerization method, and a bulk or solution polymerization method is particularly preferable. The molecular weight of the copolymer (III) is preferably 60,000 to 400,000, particularly preferably 80,000 to 300,000. The amount used is 0 to 70% by weight in the total of the copolymers (I) to (III). The acrylonitrile content of this copolymer (III) can generally be 20 to 50% by weight, but it is preferable for satisfying the required performance (for example, chip adhesion, tensile strength) of the plastic card more reliably. Is 28 to 45% by weight, most preferably 30 to 40% by weight.

  The methacrylate polymer (IV) used in the present invention is a methacrylic acid ester monomer, and optionally 0 to 20% by weight of an acrylic acid ester monomer, or other copolymerizable with these. Polymerized from 0 to 60% by weight of monomer. The weight average molecular weight is preferably from 50,000 to 450,000, more preferably from 80,000 to 400,000, and most preferably from 100,000 to 300,000.

  Specific examples of the methacrylic acid ester monomer include n-octyl methacrylate, methyl methacrylate, n-butyl methacrylate and the like. Specific examples of the acrylate monomer include n-hexyl acrylate, methyl acrylate, ethyl acrylate, butyl acrylate, octadecyl acrylate, and the like. These monomers may be polymerized alone or in combination of two or more. Other monomers copolymerizable with these include acrylonitrile, styrene, maleic anhydride, α-methylstyrene, and mixtures thereof.

  The methacrylate polymer (IV) used in the present invention is generally polymerized in the presence of a solvent. The solvent is used so that the polymer solid content is 50% by weight or less, but the solid content is preferably 40% by weight or less. Such solvents include hexane, heptane, octane, benzene, toluene, xylene, cyclohexane, cyclohexene, cyclodecane, isooctane, aliphatic hydrocarbons such as naphtha or aromatic hydrocarbons such as naphtha, methyl ethyl ketone, methyl isobutyl ketone, acetic acid. A polar solvent such as ethyl can be used. These solvents preferably have a boiling point of 40 to 225 ° C under normal pressure, and more preferably 60 to 150 ° C.

  Polymerization of the methacrylate polymer (IV) can be performed using a radical initiator. Such radical initiators include dibenzoyl peroxide, dicumyl peroxide, 2,2'-azo-bisisobutyronitrile, 2,2'-azo-bisdimethylvaleronitrile, azobis-2-methylisobutyronitrile. , Dimethyl 2,2'-azobisisobutyrate, diethyl peroxide, distearyl peroxide, t-butyl peroxide, 2,4-dichlorobenzoyl peroxide, acetyl peroxide, t-butyl peroxybenzoate, t- Examples include pentyl peroxy octoate, 1,1-bis-t-butyl peroxycyclohexane, and a particularly practical initiator is 2,2′-azo-bisisobutyronitrile. When the initiator is used, the amount used is 0.01 to 1% by weight, preferably 0.03 to 0.5% by weight, and most preferably 0.07 to 0.1% by weight based on the total amount of the monomer mixture to be fed. The amount of the methacrylate polymer (IV) used in the present invention is 2 to 35 parts by weight with respect to 100 parts by weight of the rubber-modified styrene resin comprising the copolymers (I) to (III). When the amount of the methacrylate polymer (IV) used is less than 2 parts by weight, the adhesion kinetic properties and mold contamination resistance of the rubber-modified styrenic resin composition for plastic card to be produced are deteriorated. On the other hand, when the amount used exceeds 35 parts by weight, the fluidity and impact strength of the rubber-modified styrenic resin composition for plastic cards to be produced are deteriorated, and the bending resistance is also slightly deteriorated.

  If necessary, other additives can be added to the rubber-modified styrene resin composition for plastic cards of the present invention. Examples of such additives include antioxidants, plasticizers, processing aids, light stabilizers, ultraviolet absorbers, fillers, reinforcing agents, colorants, lubricants, antistatic agents, flame retardants, flame retardant aids, There are heat stabilizers. Such an additive can be added during the polymerization reaction, after the polymerization reaction, before the latex coagulation, or during the extrusion kneading step. Each additive is specifically shown below, but all of the addition amounts are shown in amounts relative to 100 parts by weight of the total of the copolymers (I) to (III) and the methacrylate polymer (IV).

Antioxidants include phenolic antioxidants, thioether antioxidants, phosphorus antioxidants, chelating agents, and the like.
The addition amount of the phenolic antioxidant is preferably 0.005 to 2.0 parts by weight, and typical examples thereof include octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, triethylene glycol bis-3. -(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate, tetrakis [methylene-3- (3,5-bis-t-butyl-4-hydroxyphenyl) propionate] methane, 2-t-butyl -6- (3-t-butyl-2-hydroxy-6-methylbenzyl) -4-methylphenylpropionate, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'- Thiobis (4-methyl-6-t-butylphenol), 2,2'-thiodiethylenebis (3- (3,5-bis-t-butyl-4-hydroxyphenyl) propionate, 2,2'-ethyleneglycolamide And bis [ethyl-3- (3,5-bis-t-butyl-4-hydroxyphenyl) propionate.

  The amount of thioether-based antioxidant added is preferably 0.005 to 2.0 parts by weight, and typical examples thereof include distearyl thiodipropionate, dihexadecyl thiodipropionate, pentaerythritol tetra (β-dodecylthiopropionate), And bisoctadecyl thioether.

  The addition amount of the phosphorus-based antioxidant is preferably 0.015 to 2.0 parts by weight, and typical examples thereof include phosphite ester-based antioxidants and phosphinic acid ester-based antioxidants. More specifically, tri (nonylphenyl) phosphite, dodecyl phosphite, cycloneopentyl tetrahydronaphthalene bis (octadecyl phosphite), 4,4′-butyl bis (3-methyl-6-t- Butylphenylbistridecanoyl phosphite, tri (2,4-t-butylphenyl) phosphite, tetra (2,4-t-butylphenyl) -4,4'-diphenylenephosphite, 9 , 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and the like.

  The amount of the chelating agent added is preferably 0.001 to 2.0 parts by weight, and specific examples include dibenzoylmethane and ethylenediaminetetraacetic acid sodium salt.

The amount of lubricant added is preferably 0.03 to 5.0 parts by weight. Specific examples include metal soaps such as calcium stearate, magnesium stearate, and lithium stearate, ethylene distearyl amide, palmitic acid amide, butyl stearate, palmyl stearate. , Polypropylene glycol stearate, compounds such as n-docosanilic acid, stearic acid, polyethylene wax, octacosanoic acid wax, carnuba wax, petroleum wax and the like. In order to improve the extrusion moldability and thermoformability of the resin composition, a processing aid such as methacrylic acid ester can be added. Examples of the processing aid include a core-shell type processing aid having a weight average molecular weight of 500,000 or more. Agents.
The addition amount of the ultraviolet absorber is preferably 0.02 to 2.0 parts by weight, and specific examples include benzotriazole compounds, diphenyl ketone compounds, cyanoacrylic compounds and the like. Examples of the light stabilizer include hindered amine compounds.

  In order to improve the weather resistance and ultraviolet resistance of the resin, it is preferable to use an ultraviolet absorber such as a hindered amine light stabilizer and a cyanoacrylic acid compound in combination. For example, it is desirable to use the product name uvinul 4050H (0.02 to 1.0% by weight) and the product name uvinul 3035 (0.02 to 1.0% by weight) provided by BASF (Ludwigshafen, Germany).

  Representative examples of antistatic agents include low molecular weight compounds such as tertiary amine compounds and quaternary ammonium salt compounds, or permanent antistatic polymer materials such as polyamide polyethers and polyethylene oxide. It is done.

  Specific examples of the filler include calcium carbonate, silica, mica and the like.

  Examples of the reinforcing agent include glass fiber, carbon fiber, and various whiskers.

  Typical examples of the colorant include titanium oxide, iron oxide, graphite, and phthalocyanine dye.

  Specific examples of the heat stabilizer include dibutyltin maleate and basic magnesium stearate. On the other hand, a low molecular weight styrene-maleic anhydride copolymer can be used as the thermal discoloration inhibitor, and the amount added is preferably 0.1 to 1.0 part by weight.

  As a typical mixing method for obtaining the resin composition of the present invention, generally, after each resin component is dry blended with a high speed mixer or the like, an extruder (single screw or twin screw type), a kneader or a Banbury mixer, etc. The method of melt-kneading with a kneader is mentioned.

  As molding methods suitable for the resin composition of the present invention, there are molding methods such as injection molding, extrusion molding, blow molding, and vacuum molding.

  Hereinafter, based on an Example and a physical-property evaluation result, this invention is demonstrated in detail. In the examples, unless otherwise specified, the blending amount is shown in wt% or parts by weight.

  The following examples and the description thereof relate to the present invention, but do not limit the scope of the claims of the present application.

Production Example 1: Production of rubber-like graft copolymer (I-1) In order to produce rubber-like graft copolymer (I-1), graft copolymers (A) and (B) were prepared as shown below. Manufactured.
(1) Preparation of graft copolymer (A) Component Weight part
1,3-Butadiene 95.0
Acrylonitrile 5.0
Potassium persulfate solution 15.0
Sodium pyrophosphate 3.0
Potassium oleate 1.5
Distilled water 140.0
t-Dodecyl mercaptan 0.2

  The above components were reacted at a reaction temperature of 65 ° C. for 12 hours to obtain a synthetic rubber latex having a conversion rate of 94%, a solid content of about 40%, and a weight average particle size of 0.1 μm.

In addition, a carboxyl group-containing polymer flocculant composed of the following components was produced.
Ingredients by weight
n-Butyl acrylate 85.0
Methacrylic acid 15.0
t-Dodecyl mercaptan 0.3
Potassium oleate 2.0
Dioctyl sodium sulfosuccinate 1.0
Cumene hydroperoxide 0.4
Sodium formaldehyde sodium sulfate 0.3
Distilled water 200.0

  The above components were reacted at a reaction temperature of 75 ° C. for 5 hours to obtain a carboxyl group-containing polymer flocculant having a conversion rate of 95% and a pH value of 6.0.

  Then, 3 parts by weight of the carboxyl group-containing polymer flocculant (solid content) was used to enlarge 100 parts by weight of the synthetic rubber latex (solid content). The enlarged rubber latex had a pH value of 8.5 and a weight average particle size of 0.3 μm.

  Finally, the enlarged rubber latex was graft-polymerized with the following composition to obtain a graft copolymer (A) (rubber content was 75% by weight) having a weight average particle diameter of 0.31 μm. In the graft polymerization, styrene / acrylonitrile contained in the following blending components was continuously added to the reaction system over 5 hours for polymerization.

Ingredient Weight part Enlarged rubber latex (solid content) 100.0
Styrene 25.0
Acrylonitrile 8.3
Potassium oleate 1.2
t-Dodecyl mercaptan 0.2
Cumene hydroperoxide 0.5
Ferrous sulfate solution (0.2%) 3.0
Formaldehyde conversion sodium sulfate solution (10%) 3.0
Ethylenediaminetetraacetic acid sodium solution (0.25%) 20.0
Distilled water 200.0

(2) Production of Graft Copolymer (B) Using synthetic rubber latex (rubber particle weight average particle size is 0.1 μm) obtained in the production of (1) Graft Copolymer (A), the following composition To give a non-hypertrophic graft copolymer (B). The rubber particles had a weight average particle size of 0.1 μm and a rubber content of 50% by weight.

Ingredient Weight part Synthetic rubber latex (solid content) 100.0
Styrene 75.0
Acrylonitrile 25.0
Potassium oleate 2.0
t-Dodecyl mercaptan 0.6
Cumene hydroperoxide 1.4
Ferrous sulfate solution (0.2%) 8.6
Formaldehyde sodium sulfate solution (10%) 8.6
Sodium ethylenediaminetetraacetate solution (0.25%) 57.0
Distilled water 200.0

The graft copolymer (A) and the graft copolymer (B) were separately coagulated with calcium chloride (CaCl ₂ ), dehydrated, and further dried to a water content of 2% or less. Then, the graft copolymer (A) / (B) is mixed at a weight ratio of 60/40, and the rubber-like graft copolymer having a bimodal particle size distribution in which the weight average particle diameter of the rubber particles is 0.1 μm and 0.31 μm. Combined (I-1) (rubber content 65 weight%) was obtained.

Production Example 2: Preparation of rubber-like graft copolymer (I-2) Same as graft copolymer (A) in Production Example 1, with a rubber content of 75% by weight and a weight average particle size of rubber particles of 0.31. It was μm.

Production Example 3: Production of Rubber-like Graft Copolymer (I-3) Same as Graft Copolymer (B) in Production Example 1, the rubber content is 50% by weight, and the weight average particle diameter of the rubber particles is 0.1. It was μm.

Production Example 4: Preparation of rubber-like graft copolymer (II)
0.08 parts by weight of benzoyl peroxide was used as an initiator, and 6.6 parts by weight of polybutadiene (Asaden 55AS from Asahi Kasei Co., Ltd.) was completely dissolved in 74.4 parts by weight of styrene, 25.6 parts by weight of acrylonitrile, and 30 parts by weight of ethylbenzene to form a raw material solution. The raw material solution was continuously charged into a 45 liter first reactor. This reactor has a propeller stirrer with a cooling circulation pipe inside. By maintaining the stirring speed at 150 rpm at a reaction temperature of 100 ° C., the monomer conversion in the first reactor was 15%. The reaction mixture in the first reactor was continuously taken out and fed sequentially to the second, third and fourth reactors. In addition, 0.1 weight part of t-dodecyl mercaptan was added in the 3rd reactor. It was confirmed that the phase inversion phenomenon occurred in the second reactor. The second, third, and fourth reactors had the same specifications as the first reactor, and the reaction temperatures were maintained at 105 ° C., 110 ° C., and 125 ° C., and the stirring speeds were maintained at 270 rpm, 150 rpm, and 110 rpm.

  When the conversion rate of the mixture reaches 60%, the mixture is taken out and sent to a devolatilizer to separate and remove unreacted monomers and volatile components, extruded and pelletized, and the weight average particle diameter of rubber particles is 0.95. A granular rubber-like graft copolymer (II) having a μm and a rubber content of 11% by weight was obtained.

Production Example 5 Production of Copolymer (III) 60% by weight of styrene and 40% by weight of acrylonitrile were mixed at a feed rate of 12 kg / hr, ethylene distearylamide was added thereto at 3.0 g / hr, and benzoyl par Oxide, t-dodecyl mercaptan, and a recovered liquid composed of unreacted monomers and volatiles recovered by cooling from the reaction system described later were mixed together to form a raw material solution. This raw material solution was supplied to a 45 liter continuous kettle reactor equipped with a stirrer, the temperature was set at 108 ° C., and the polymerization rate was maintained at 55%.

  Unreacted monomers and other volatile components were removed from the reaction solution through a devolatilizer to obtain styrene copolymer pellets. These removed volatile components were condensed by a condenser to obtain a recovered liquid, which was recycled to the raw material solution system described above. In this system, the reaction rate was adjusted by the amount of benzoyl peroxide and the amount of t-dodecyl mercaptan was controlled to obtain a styrene-acrylonitrile copolymer (III) having an acrylonitrile content of 32% by weight.

Evaluation methods

Various properties of the rubber-modified styrene resin composition of the present invention were evaluated by the following methods.
(1) Fluidity: Using an IS100EN injection molding machine manufactured by Toshiba Machine Co., Ltd., using a spiral flow mold under molding conditions of a cylinder temperature of 220 ° C., a mold temperature of 60 ° C., and an injection pressure of 600 kg / cm ^2. It was injection molded and the flow length of the resin was evaluated.

(2) Impact resistance: Izod impact strength was measured based on ASTM-D256 (23 ° C., notched thickness 1/4 inch test sheet). The unit is expressed in kg-cm / cm.

(3) Bending resistance (bending strength): 8.5cm x 5.5cm x 0.25cm (length x width x thickness) injection-molded sheet (ABCD rectangle in Fig. 1) was prepared, and both ends of the diagonal of the rectangular sheet Were fitted into two roller cuts (EF in FIG. 1). The diameter of the roller (3.4cm) is about 1/3 of the diagonal length of the sheet, and the cut line on the roller is about 2cm long (EF) and the depth at which the sheet is fitted 1cm (UV in Fig. 2) And The distance from the horizontal cut to the top of the roller (XY in FIG. 2) is about 0.5 cm. Then, as shown in FIG. 1, the two rollers fitted with the sheet horizontally in the cut are brought close to each other and stopped when they collide with each other, and the two rollers are rotated in the opposite directions, and the rectangular sheet is rotated. Move until is straight (flat). One cycle so far, and one cycle takes about 2 seconds. The evaluation was based on the following criteria.
○: Whitening cracks do not occur even after 5000 cycles or more.
Δ: Some whitening cracks occur between 3000 cycles and less than 5000 cycles.
X: Severe whitening crack occurs at 3000 cycles or less.

(4) Thermal stability: An injection-molded sheet having a size of 4 inches x 4 inches x 1/8 inch (length x width x thickness) is left in a constant temperature bath at 180 ° C for 60 minutes. Changes in hue were observed and evaluated according to the following criteria.
○: The color became light yellow.
Δ: The color became yellow.
X: The color became brown.

(5) Tensile strength: Tensile strength was measured based on ASTM-D638. Units are expressed in kg / cm ^2.

(6) Adhesive strength measurement method: An injection molded sheet of 100 mm × 12.7 mm × 5 mm (length × width × thickness) was used as a test piece, and the two test pieces were bonded as shown in FIG. In other words, 0.2cc of cyano adhesive (manufactured by Arteco, Japan) was evenly applied to both sides of the IC chip (13mm x 11mm), and the test specimens were quickly bonded and pasted to each side, and the adhesive part was attached. A 1 kg load was applied and the mixture was allowed to stand for 1 hour. Then, an adhesion kinetic property analysis (USA Innstron 4511 Universal Testing Machines, Peel Speed: 6 mm / min) was performed. That is, as shown in FIG. 3, the fixtures at both ends were each pulled in parallel to the left and right (6 mm / min), and the tensile strength (stress required for peeling) was measured and evaluated according to the following criteria.
○: Tensile strength is 200 kg / cm ² or more.
Δ: Tensile strength exceeds 200 kg / cm ² and less than 120 kg / cm ² .
X: Tensile strength is 120 kg / cm ² or less.

(7) Resistance to mold contamination: 50 continuous shots were injection-molded at 280 ° C., and the contamination status of the mold (a little mold deposit) was observed and evaluated according to the following criteria.
○: There is no mold contamination.
Δ: There is a little mold dirt.
X: The mold dirt is severe.

[Example 1]
Under dry conditions, 30% by weight of the rubber-like graft copolymer (I-1) obtained in Production Example 1, 20% by weight of the rubber-like graft copolymer (II) obtained in Production Example 4, and in Production Example 5 Polymethylmethacrylate resin (IV-1) (Bijin Jitsugyo) with respect to a total of 100 parts by weight of the obtained styrene-acrylonitrile copolymer (III) 50% by weight and (I-1) + (II) + (III) (Acryrex CM-207, flow coefficient is 8.0 g · m / 10 min) 12 parts by weight are mixed after drying, and melt-kneaded at 220 ° C. using a ZSK35 extruder from Werner & Pfleiderer to obtain a rubber-modified styrene resin composition It was. The evaluation results are shown in Table 1.

[Examples 2 to 7]
In Examples 2 to 7, the same operations as in Example 1 were performed with the formulations shown in Table 1 to obtain rubber-modified styrene resin compositions. In particular, in Examples 5 and 7, instead of polymethyl methacrylate resin (IV-1), polymethyl methacrylate resin (IV-2) (Amirex CM-211, manufactured by Kitami Jitsugyo Co., Ltd., flow coefficient is 16.0 g · m / 10 min) Was used. The evaluation results of the rubber-modified styrenic resin composition obtained in each example are shown in Table 1.

[Comparative Examples 1-6]
In Comparative Examples 1 to 4, rubbery graft copolymer (I-1) was used, in Comparative Example 5, rubbery graft copolymer (I-2) was used, and in Comparative Example 6, rubbery graft copolymer (I-2) was used. I-3) was used respectively. Table 1 shows the blending ratio of each component. And operation similar to Example 1 was performed and the rubber-modified styrene-type resin composition was obtained. The evaluation results are shown in Table 1.

  As can be seen from Comparative Example 1, when the amount of the rubber graft copolymer (I-1) used is less than 5% by weight, the fluidity, impact strength, and tensile strength of the rubber-modified styrene resin composition are all deteriorated. A whitening phenomenon is likely to occur due to a repeated bending test (bending resistance test). As can be seen from Comparative Example 2, when the amount of the rubber graft copolymer (II) used is less than 5% by weight, the thermal stability of the resin composition is poor and the mold contamination resistance and flex resistance are poor. As can be seen from Comparative Example 3, when the amount of the methacrylate polymer (IV) used is less than 2 parts by weight, the adhesive strength between the resin composition and the IC chip is reduced, and the mold contamination resistance is also deteriorated. . As can be seen from Comparative Example 4, when the amount of the methacrylate polymer (IV) used exceeds 35 parts by weight, the fluidity and impact strength of the resin composition deteriorate and the flex resistance also deteriorates. As can be seen from Comparative Example 5, when the rubber graft copolymer (I-1) is changed to the rubber-like graft copolymer (I-2), the adhesive strength between the resin composition and the IC chip decreases. Finally, as can be seen from Comparative Example 6, when the rubber graft copolymer (I-1) is changed to the rubbery graft copolymer (I-3), the impact strength, tensile strength, and bending resistance of the resin composition are changed. Both sex and the like worsen.

  As is clear from the test results of each of the above examples, in the present invention, the resin composition is limited without limiting the impact strength, rigidity, and heat resistance by limiting the component resin and setting a specific blending ratio. A rubber-modified styrene resin composition for plastic cards, which greatly improves the thermal stability and moldability of the product, and has excellent mold contamination resistance, flex resistance, and excellent adhesion to an IC chip, In particular, a rubber-modified styrenic resin composition for plastic cards to which an IC chip is bonded can be provided.

  What has been described above is a comparative example of the present invention, and does not limit the scope of the present invention. It is claimed that all simple changes and modifications made based on the scope of the claims of the present invention and the detailed description of the invention should be included in the patent scope of the present invention.

It is the schematic which shows the state of the bending resistance test of this invention, and has shown the state by which the injection molding sheet | seat ABCD was engage | inserted into the cut | interval of two rollers horizontally with two rollers. It is a side view of the roller used for the bending resistance test of this invention, UV shows the depth of a cut | interruption, XY shows the distance of the cut | interruption set | placed in the horizontal state, and a roller surface. It is the schematic which shows the adhesion state of the test piece used for adhesive strength measurement, and a test method.

Claims (5)

5 to 95% by weight of a rubber-like graft copolymer (I) obtained by polymerizing a styrene monomer and an acrylonitrile monomer in the presence of rubber by an emulsion polymerization method, and a styrene monomer in the presence of rubber. 95 to 5% by weight of a rubber-like graft copolymer (II) obtained by polymerizing a monomer and an acrylonitrile monomer by a bulk and / or solution polymerization method, a styrene monomer, an acrylonitrile monomer, and Methacrylate based on 100 parts by weight of rubber-modified styrenic resin consisting of 0 to 70% by weight of copolymer (III) obtained by polymerizing other monomers copolymerizable with these used as required It contains 2 to 35 parts by weight of polymer (IV),
The rubber-like graft copolymer (I) has rubber particles having a bimodal particle size distribution with a weight average particle size of 0.05 to 0.18 μm and 0.2 to 1.0 μm,
A rubber-modified styrenic resin composition for plastic cards, wherein the rubber-like graft copolymer (II) has rubber particles having a weight average particle diameter of 0.5 to 10 μm.   The rubber-like graft copolymer (I) comprises a graft copolymer (A) composed of rubber particles having a weight average particle diameter of 0.2 to 1.0 μm and a graft copolymer composed of rubber particles having a weight average particle diameter of 0.05 to 0.18 μm. (B) and the weight ratio of the graft copolymer (A) to the graft copolymer (B) (graft copolymer (A) / graft copolymer (B)) is 5/95 to 95 The rubber-modified styrenic resin composition for plastic cards according to claim 1, which is / 5.   The graft copolymer (A) contains 50 to 85% by weight of a styrene monomer, 50 to 15% by weight of an acrylonitrile monomer, and other copolymerizable with these in the presence of an enlarged rubber latex. The rubber-modified styrene resin composition for plastic cards according to claim 2, obtained by graft polymerization of 0 to 40% by weight of monomers.   The graft copolymer (B) contains 50 to 85% by weight of a styrenic monomer, 50 to 15% by weight of an acrylonitrile monomer and other copolymerizable with these in the presence of an unextended rubber latex. The rubber-modified styrene resin composition for plastic cards according to claim 2, obtained by graft polymerization of 0 to 40% by weight of monomers.   In the presence of a diene rubber, the rubbery graft copolymer (II) is 50 to 85% by weight of a styrene monomer, 50 to 15% by weight of an acrylonitrile monomer and other monomers copolymerizable therewith. The rubber-modified styrenic resin composition for plastic cards according to claim 1, obtained by polymerizing 0 to 40% by weight of a polymer by a bulk and / or solution polymerization method.

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