KR20180011140A - Transparent resin composition and method for producing the same - Google Patents

Abstract

It is an object of the present invention to provide a resin composition which is transparent and excellent in heat resistance and does not cause defective appearance at the time of injection molding. (A) containing a copolymer containing an unsaturated dicarboxylic acid anhydride monomer unit and a transparent resin (B) other than the styrene series resin (A), wherein the styrene resin A total thickness of 2 mm, a total light transmittance of 88% or more, and a haze of 0.3% or less. The styrene-based resin (A) contains 45 to 90% by mass of a styrene monomer unit, 10 to 55% by mass of an unsaturated dicarboxylic acid anhydride monomer unit, (meth) acrylic acid monomer unit, (meth) , And the transparent resin (B) preferably contains at least one kind selected from a methacrylic resin, a methyl methacrylate-styrenic copolymer and a styrene-acrylonitrile-based copolymer Do.

Description

Transparent resin composition and method for producing the same

The present invention relates to a transparent resin composition and a process for producing the same.

BACKGROUND ART Transparent resins such as methacrylic resin, methyl methacrylate-styrene copolymer and styrene-acrylonitrile copolymer are used in various applications such as parts for home appliances, automobile parts, food packaging containers, construction materials, and miscellaneous goods. In addition, it is also used as an optical member for a liquid crystal display such as an optical film, a diffusion plate, and a light guide plate, taking advantage of excellent transparency. These transparent resins have problems such as good optical properties such as transparency and low heat resistance, and have been used only for limited use. As techniques for improving the heat resistance of a transparent resin, Patent Documents 1 and 2 are known.

WO 2014/021264 WO 2014/065129

The present invention provides a novel transparent resin composition and a method for producing the same.

(A) a styrene-based resin (A) comprising a copolymer comprising (1) an unsaturated dicarboxylic acid anhydride monomer unit and a transparent resin (B) other than the styrene- , A total light transmittance of not less than 88%, and a haze of not more than 0.3%.

(Meth) acrylic acid ester monomer unit and (meth) acrylic acid ester monomer unit; and (2) the styrene-based resin (A) is a copolymer of styrene type monomer units in an amount of 45 to 90% by mass and an unsaturated dicarboxylic acid anhydride monomer unit, And 10 to 55 mass% of at least one monomer unit selected from other vinyl-based monomer units copolymerizable with the vinyl monomer unit.

(3) The positive resist composition as described in (1) or (2) above, wherein the transparent resin (B) comprises at least one selected from a methacrylic resin, a methyl methacrylate-styrene copolymer and a styrene- ).

(4) The resin composition according to any one of (1) to (3), wherein the content of the styrene resin (A) is 5 to 50 mass% and the content of the transparent resin (B) is 95 to 50 mass% .

(5) The styrene-based resin (A) according to any one of (1) to (4), wherein the styrene-based resin (A) has a Vicat softening temperature of 110 ° C or higher as measured in accordance with JIS K7206 at a load of 50N and a heating rate of 50 ° C / Resin composition.

(6) A molded article obtained by injection molding the resin composition according to any one of (1) to (5).

(7) A styrene resin (A) containing a copolymer containing an unsaturated dicarboxylic acid anhydride monomer unit and a transparent resin (B) other than the styrene resin (A) And feeding the resulting mixture to an extruder, followed by melt-kneading.

(8) The thermoplastic resin composition according to any one of the above items (1) to (5), wherein the styrene resin (A) comprises 45 to 90% by mass of a styrene monomer unit and at least one monomer selected from the group consisting of an unsaturated dicarboxylic acid anhydride monomer unit, And 10 to 55% by mass of at least one monomer unit selected from other vinyl-based monomer units copolymerizable with the vinyl monomer unit.

(9) The photosensitive resin composition according to any one of (7) to (8), wherein the transparent resin (B) comprises at least one member selected from the group consisting of a methacrylic resin, a methylmethacrylate-styrene copolymer and a styrene- ). ≪ / RTI >

(10) The resin composition according to any one of (7) to (9), wherein the content of the styrene resin (A) is 5 to 50 mass% and the content of the transparent resin (B) is 95 to 50 mass% ≪ / RTI >

(11) The styrene-based resin (A) according to any one of (7) to (10), wherein the styrene type resin (A) has a Vicat softening temperature of 110 ° C or higher as measured in accordance with JIS K7206 under a load of 50N and a temperature rising rate of 50 ° C / A method for producing a resin composition.

The resin composition of the present invention is useful for components, automobile parts, building materials, optical members, food containers, and the like which are required to have heat resistance and good appearance in view of excellent transparency. Particularly, Loses.

<Explanation of Terms>

In the present specification, for example, the phrase &quot; A to B &quot; means not less than A and B or less.

Hereinafter, embodiments of the present invention will be described in detail.

The transparent resin composition of the present invention comprises a styrene type resin (A) containing a copolymer containing an unsaturated dicarboxylic acid anhydride type monomer unit and a transparent resin (B) other than the styrene type resin (A) , A total light transmittance of 2 mm thickness measured based on ASTM D1003 of 88% or more and haze of 0.3% or less. This resin composition is obtained by feeding styrene resin (A) and transparent resin (B) to an extruder using separate quantitative feeders and melt-kneading.

The styrene-based resin (A) is a copolymer containing a styrene-based monomer unit and an unsaturated dicarboxylic acid anhydride-based monomer unit and is a copolymer of a (meth) acrylic acid-based monomer unit, a (meth) And at least one monomer unit selected from other vinyl-based monomers. Examples of the styrene resin (A) include styrene-methyl methacrylate-maleic anhydride copolymer, styrene-maleic anhydride copolymer and the like.

Examples of the styrene monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, pt-butylstyrene, . Of these, styrene is preferable. The styrene-based monomer may be used singly or in combination of two or more.

Examples of the unsaturated dicarboxylic acid anhydride monomer include maleic anhydride, itaconic anhydride, citraconic anhydride, and aconitic anhydride. Of these, maleic anhydride is preferred. The unsaturated dicarboxylic acid anhydride monomer may be used singly or in combination of two or more.

The (meth) acrylic acid-based monomer unit is acrylic acid, methacrylic acid or the like, and among these, methacrylic acid is preferable.

The (meth) acrylic acid ester monomer unit includes, for example, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate, isobornyl methacrylate And methacrylic acid ester monomers such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate and decyl acrylate. Of these, methyl methacrylate units are preferred. The (meth) acrylic acid ester monomer may be used singly or in combination of two or more.

As other vinyl-based monomers capable of copolymerization, acrylonitrile monomers such as acrylonitrile, methacrylonitrile, ethacrylonitrile, and fumaronitrile, and N-substituted maleimide monomers such as N-phenylmaleimide can be used have.

The constitutional unit of the styrene-based resin (A) is a copolymer comprising 45 to 90% by mass of a styrene monomer unit, an unsaturated dicarboxylic acid anhydride monomer unit, a (meth) acrylic acid monomer unit, a (meth) And 10 to 55% by mass of at least one monomer selected from other vinyl-based monomers copolymerizable with the vinyl monomer. More preferably 45 to 85% by mass of the styrene monomer unit, 10 to 30% by mass of the unsaturated dicarboxylic acid anhydride monomer unit and 5 to 45% by mass of the (meth) acrylic acid ester monomer unit, great. The compositional analysis of each monomer unit is a value measured under the measurement conditions described below by the C-13 NMR method.

Device name: FT-NMR AVANCE 300 (manufactured by Bruker)

Solvent: deuterated chloroform

Concentration: 14 mass%

Temperature: 27 ℃

Accumulated count: 8,000 times

The weight average molecular weight (Mw) of the styrene type resin (A) is preferably 50,000 to 300,000, and more preferably 100,000 to 250,000. When the weight average molecular weight (Mw) is in the range of 50,000 to 300,000, the balance between strength and moldability is preferable. The weight average molecular weight (Mw) can be controlled by the polymerization temperature and polymerization time in the polymerization step, the kind and amount of the polymerization initiator, the kind and amount of the chain transfer agent, the kind and amount of the solvent used in polymerization, and the like. The weight average molecular weight (Mw) is a value measured in terms of polystyrene measured by gel permeation chromatography (GPC), and is a measured value under the measurement conditions described below.

Device name: SYSTEM-21 Shodex (manufactured by Showa Denko)

Column: 3 serial PLgel MIXED-B

Temperature: 40 ° C

Detection: differential refractive index

Solvent: tetrahydrofuran

Concentration: 2 mass%

Calibration curve: Prepared using standard polystyrene (PS) (manufactured by PL).

As the polymerization method of the styrene type resin (A), a known method can be adopted. From the viewpoint of a simple process and excellent productivity, the radical polymerization method is preferable.

As a method for producing the styrene-based resin (A), a known method can be adopted. For example, by solution polymerization, bulk polymerization and the like. In addition, both the continuous method and the batch method can be applied. In the copolymerization of the styrene-based monomer and the unsaturated dicarboxylic acid anhydride-based monomer, since the alternating copolymerization is high, the solution polymerization is preferably carried out in such a manner that the copolymerization composition can be made uniform by polymerization while the unsaturated dicarboxylic acid anhydride- desirable. The solvent for the solution polymerization is preferably a non-condensed polymer in view of difficulty of producing by-products and less adverse effects, and examples thereof include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, tetrahydrofuran, Aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, N, N-dimethylformamide, dimethylsulfoxide, N-methyl-2-pyrrolidone and the like.

In the solution polymerization or bulk polymerization of the styrene type resin (A), a polymerization initiator and a chain transfer agent can be used, and the polymerization temperature is preferably in the range of 70 to 180 ° C. Examples of the polymerization initiator include dibenzoyl peroxide, t-butyl peroxybenzoate, 1,1-bis (t-butylperoxy) -2-methylcyclohexane, t-butylperoxyisopropyl monocarbonate , peroxides such as t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyacetate, dicumyl peroxide and ethyl-3,3-di- (t-butylperoxy) Azo compounds such as acetonitrile, butyronitrile, azobiscyclohexanecarbonitrile, azobismethylpropionitrile and azobismethylbutyronitrile, and these may be used alone or in combination of two or more. Two or more of these polymerization initiators may be used in combination. Among them, it is preferable to use an organic peroxide having a 10-hour half-life temperature of 70 to 110 ° C. The chain transfer agent includes, for example, n-octylmercaptan, n-dodecylmercaptan, t-dodecylmercaptan,? -Methylstyrene dimer, ethyl thioglycolate, limonene and terpinolene.

As a devolatilizing method for removing volatile components such as unreacted monomers and a solvent used for solution polymerization from the solution after completion of the polymerization of the styrene type resin (A), known methods can be employed. For example, a vacuum degassing vessel equipped with a preheater or a degassing extruder equipped with a vent may be used. The devolatilized styrenic resin (A) in a melted state is sent to a granulation process, extruded into a strand shape by a porous die, and processed into a pellet by a cold cut method, an air hot cut method or an underwater hot cut method .

From the viewpoint of transparency, the total light transmittance of the styrene resin (A) according to the present invention measured on the basis of ASTM D1003 is preferably not less than 88% and not more than 0.5%, more preferably not more than 0.5% The light transmittance is 90% or more, and the haze is 0.3% or less. The styrene resin (A) having excellent transparency is obtained by polymerization so that the copolymer composition distribution becomes small.

According to JIS K7206, the Vicat softening temperature of the styrenic resin (A), which is determined by a load of 50N and a heating rate of 50 占 폚 / hour, is preferably 115 占 폚 or higher, and more preferably 125 占 폚 or higher. The higher the Vicat softening temperature, the higher the effect of improving the heat resistance of the methacrylic resin. The Vicat softening temperature of the styrene-based resin (A) can be adjusted by the content of a heat-resistant monomer such as an unsaturated dicarboxylic acid anhydride monomer unit or a (meth) acrylic acid-based monomer unit.

The transparent resin (B) is transparent and is compatible with the styrenic resin (A) at a temperature during melt-kneading and molding, and examples thereof include methacrylic resin, methyl methacrylate-styrene copolymer, styrene- Acrylonitrile-based copolymer and the like. Among them, the methacrylic resin is preferred because of its excellent optical properties. The constituent unit of the methyl methacrylate-styrene copolymer system is preferably 70 to 97% by mass of methyl methacrylate unit and 3 to 30% by mass of styrene. The constituent unit of the styrene-acrylonitrile-based copolymer is preferably 70 to 85% by weight of styrene and 15 to 30% by weight of acrylonitrile. As the methacrylic resin, methyl methacrylate-styrene copolymer and styrene-acrylonitrile copolymer, commercially available ones can be used. The shape may be pellets or beads, but the particle size distribution is preferably aligned.

From the viewpoint of transparency, the total light transmittance of the transparent resin (B) according to the present invention measured on the basis of ASTM D1003 is preferably not less than 88% and haze is not more than 0.5%, more preferably not more than 0.5% The transmittance is 90% or more, and the haze is 0.3% or less.

It is necessary to quantitatively supply the styrenic resin (A) and the transparent resin (B) to an extruder using separate quantitative feeders. The feed port of the extruder may be provided in one place as long as a separate quantitative feeder is used for each resin, or a plurality of feed ports may be provided in accordance with the number of the fixed feeders. A method in which a styrene resin (A) and a transparent resin (B) are dry-blended, and then a hopper is fed to an extruder provided at a single feed port or a dry blend is carried out in an extruder equipped with only one fixed feeder In the method of collectively feeding the resin composition, the molded resin is shaken inside and the appearance is defective when the obtained resin composition is injection-molded. This fluctuation is caused by the non-uniformity of the refractive index and occurs when the blending ratio of the styrene type resin (A) and the transparent resin (B) varies in the resin composition. In the injection molding, the molten resin introduced from the gate is filled in the mold while expanding like a balloon in the flow direction. Therefore, when there is variation in the mixing ratio, portions having different refractive indices are generated in the layer shape and observed as shaking. When the shaking becomes remarkable, it may be seen as a striped shape. In addition, this fluctuation is sometimes referred to as striae. In the method of collectively feeding the extruder after dry blending, segregation occurs due to difference in shape or density between the styrene type resin (A) and the transparent resin (B), and the blending ratio varies.

Two or more kinds of the styrene type resin (A) or the transparent resin (B) can be used in a common range, but it is necessary to use a separate feeder. The supply ratio of the styrene type resin (A) and the transparent resin (B) may be arbitrarily set within a range compatible with the styrene type resin (A) and the transparent resin (B).

The feeder is a device for feeding a pellet or a bead-shaped raw material resin to an extruder, and a known feed can be used. However, since it is necessary to supply a quantitative raw material, it is necessary to use a quantitative feeder. Examples of the quantitative feeder include a loss in weight feeder, a volumetric feeder, a weighted belt feeder, and the like. Particularly, a loss in weight feeder is preferable, and feed accuracy is preferably within ± 1%. It is preferable that each of the feeders is controlled in cooperation with each other, and it is preferable to control the supply amount of the other feeder to a constant ratio with respect to the main feeder supply amount.

The raw resin supplied to the extruder is continuously melted and kneaded in an extruder, extruded from a porous die into a strand shape, and a pellet-shaped resin composition is obtained by a cold cut method, an air hot cut method or an underwater hot cut method. As the extruder, a known apparatus can be used, and for example, a twin-screw extruder, a single screw extruder, a multiaxial screw extruder, a continuous kneader with a biaxial rotor, and the like can be given.

Additives such as an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, a lubricant, a dye and a flame retardant may be added to the resin composition within a range that does not impair transparency.

The content of the styrene resin (A) and the transparent resin (B) in the resin composition is preferably 5 to 50 mass% and 95 to 50 mass%, more preferably 15 to 50 mass% and 85 to 50 mass% %, More preferably 15 to 35 mass% and 85 to 65 mass%, respectively. By setting the content of the styrene resin (A) and the transparent resin (B) to 5 to 50 mass% and 95 to 50 mass%, respectively, a transparent resin composition excellent in balance between heat resistance and surface hardness can be obtained.

From the viewpoint of transparency, the total light transmittance of the resin composition of the present invention measured on the basis of ASTM D1003 of 2 mm thickness is 88% or more and the haze is 0.3% or less. The total light transmittance is preferably 90% or more. The haze is preferably 0.2% or less. The styrene-based resin (A) and the transparent resin (B) are compatible with each other and are produced by the method of the present invention, whereby a resin composition having excellent transparency can be obtained.

The Vicat softening temperature of the resin composition determined by a load of 50 N and a heating rate of 50 占 폚 / hour in accordance with JIS K7206 is preferably 110 占 폚 or higher, more preferably 113 占 폚 or higher, and even more preferably 115 占 폚 or higher. The higher the Vicat softening temperature, the more members can be applied.

As the molding method of the resin composition, a known method can be adopted. For example, injection molding, press molding, sheet molding, and the like. Particularly, injection molding is suitable in that molding defects such as shaking do not occur inside the molded article. The molding defects of the shake shape are particularly noticeable in an injection molded article having a large thickness, but the resin composition of the present invention does not cause appearance defects even in the case of an injection molded article having a large thickness.

Example

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples.

&Lt; Styrene-based resin (A) >

&Lt; Production example of styrene type resin (A-1) >

A 20% maleic anhydride solution dissolved in methyl isobutyl ketone so that the concentration of maleic anhydride is 20 mass%, and a solution of maleic anhydride dissolved in methyl isobutyl ketone so that the amount of t-butyl peroxy-2-ethylhexanoate becomes 2 mass% A 2% t-butylperoxy-2-ethylhexanoate solution was prepared in advance and used for polymerization. In a 120-liter autoclave equipped with a stirrer, 3.6 kg of 20% maleic anhydride solution, 24 kg of styrene, 8.8 kg of methyl methacrylate and 20 g of t-dodecylmercaptan were charged, the gaseous portion was replaced with nitrogen gas, And the temperature was raised to 88 DEG C over 40 minutes. The temperature was raised to 88 ° C, and a 20% maleic anhydride solution at 2.7 kg / hour and a 2% t-butyl peroxy-2-ethylhexanoate solution at a sequential rate of 375 g / Lt; / RTI &gt; Thereafter, the addition of 2% t-butylperoxy-2-ethylhexanoate solution was stopped, and 40 g of t-butylperoxyisopropyl monocarbonate was added. The 20% maleic anhydride solution was heated to 120 ° C over 4 hours at a heating rate of 8 ° C / hour, while maintaining an autoclaving rate of 2.7 kg / hr. The addition of the 20% maleic anhydride solution was stopped when the amount of the addition amounted to 32.4 kg. After elevating the temperature, the polymerization was terminated by maintaining the temperature at 120 ° C for 1 hour. The polymerized liquid was fed continuously to a biaxial extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomers were subjected to devolatilization treatment and extruded in a strand shape to be cut to obtain a styrene type resin (A- 1). Composition A-1 was analyzed by C-13 NMR method. The molecular weight was also measured with a GPC apparatus. The compositional analysis was carried out. The structural units of A-1 were 60% by mass of styrene monomer units, 22% of methyl methacrylate monomer units, and 18% by mass of maleic anhydride monomer units. The weight average molecular weight (Mw) was 160,000, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) was 2.4. The total light transmittance of the 2 mmt mirror-finished plate molded by injection molding was 91% and haze was 0.2%. According to JIS K7206, the Vicat softening temperature, which was determined by a load of 50 N and a heating rate of 50 占 폚 / hour, was 133 占 폚.

&Lt; Production example of styrene type resin (A-2) >

A 20% maleic anhydride solution and a 2% t-butyl peroxy-2-ethylhexanoate solution were prepared in the same manner as in A-1. 2.8 kg of a 20% maleic anhydride solution, 25.6 kg of styrene, 8.8 kg of methyl methacrylate and 20 g of t-dodecylmercaptan were charged into a 120-liter autoclave equipped with a stirrer, the gaseous portion was replaced with nitrogen gas, The temperature was raised to 88 DEG C over 40 minutes while stirring. After the temperature rise, 2.1 kg / hour of a 20% maleic anhydride solution and 2% t-butyl peroxy-2-ethylhexanoate solution were continuously fed at a seeding rate of 500 g / Lt; / RTI &gt; Thereafter, the addition of 2% t-butylperoxy-2-ethylhexanoate solution was stopped, and 40 g of t-butylperoxyisopropyl monocarbonate was added. The 20% maleic anhydride solution was heated to 120 DEG C over 4 hours at a heating rate of 8 DEG C / hour while maintaining an autoclave rate of 2.1 kg / hr. The addition of the 20% maleic anhydride solution was stopped when the amount of the added water was 25.2 kg. After the temperature was elevated, the polymerization solution was maintained at 120 DEG C for 1 hour and the polymerization was terminated. The polymerization solution was fed continuously to a biaxial demagnetization extruder by using a gear pump to conduct devolatilization of methyl isobutyl ketone and a small amount of unreacted monomers, Extruded and cut to obtain a styrene-based resin (A-2) in the form of pellets. The obtained composition A-2 was subjected to composition analysis, molecular weight and total light transmittance in the same manner as in A-1. The compositional analysis was carried out. The constituent units of A-2 were 64 mass% of styrene monomer units, 22 mass% of methyl methacrylate monomer units and 14 mass% of maleic anhydride monomer units. The weight average molecular weight (Mw) was 170,000, and the ratio of the number average molecular weight (Mn), Mw / Mn, was 2.6. The total light transmittance of the 2 mmt mirror-finished plate molded by injection molding was 91% and haze was 0.2%. According to JIS K7206, the Vicat softening temperature, which was determined by a load of 50 N and a heating rate of 50 占 폚 / hour, was 126 占 폚.

&Lt; Production example of styrene type resin (A-3 >

A 25% maleic anhydride solution dissolved in methyl isobutyl ketone was prepared in advance so that the concentration of maleic anhydride was 25 mass%, and was used for polymerization. The 2% t-butylperoxy-2-ethylhexanoate solution was adjusted and used for polymerization in the same manner as in the production example of (A-1). 3.52 kg of 25% maleic anhydride solution, 24 kg of styrene, 7.2 kg of methyl methacrylate and 20 g of t-dodecylmercaptan were charged into a 120-liter autoclave equipped with a stirrer, and the gas phase portion was replaced with nitrogen gas, And the temperature was raised to 92 캜 over 40 minutes. After the temperature was elevated, the 25% maleic anhydride solution and the 2% t-butyl peroxy-2-ethylhexanoate solution were continuously added while maintaining the temperature at 92 ° C. From the 4th hour to the 7th hour, 3.17 kg / hour, from the 7th hour to the 10th hour, 1.58 kg / hour from the 10th hour to the 13th hour from the 4th hour, The rate of addition was changed stepwise to give an addition rate of 0.54 kg / hr until the time, and a total of 31.71 kg was added. The 2% t-butyl peroxy-2-ethylhexanoate solution was added at a rate of 0.24 kg / hr from the start of the addition to the 7 th hour and at a rate of 0.39 kg / hr from the 7 th hour to the 13 th hour, And 4.02 kg in total was added. The polymerization temperature was maintained at 92 ° C from the start of the addition to the 7th hour, then the temperature was elevated to 116 ° C over 6 hours at a heating rate of 4 ° C / hour, and the polymerization was terminated at 116 ° C for 1 hour. The polymerized liquid was fed continuously to a biaxial extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomers were subjected to devolatilization treatment and extruded in a strand shape to be cut to obtain a styrene type resin (A- 3). The obtained composition A-3 was subjected to composition analysis, molecular weight and total light transmittance as in A-1. Analysis of the composition revealed that the constituent units of A-3 were 60% by mass of styrene monomer units, 18% of methyl methacrylate monomer units, and 22% by mass of maleic anhydride monomer units. The weight average molecular weight (Mw) was 160,000, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) was 2.4. The total light transmittance of the 2 mmt mirror-finished plate molded by injection molding was 90% and haze was 0.2%. According to JIS K7206, the Vicat softening temperature determined by a load of 50N and a temperature raising rate of 50 占 폚 / hour was 142 占 폚.

&Lt; Transparent Resin (B) >

&Lt; Transparent resin (B-1) >

As the transparent resin (B-1), a methacrylic resin (Acryphet VH manufactured by Mitsubishi Rayon Co., Ltd.) was used. According to JIS K7206, the Vicat softening temperature, which was determined by a load of 50 N and a heating rate of 50 占 폚 / hour, was 108 占 폚.

&Lt; Transparent resin (B-2) >

As the transparent resin (B-2), a methyl methacrylate-styrene copolymer having 80 mass% of methyl methacrylate unit and 20 mass% of styrene unit was used. According to JIS K7206, the Vicat softening temperature, which was determined by a load of 50 N and a heating rate of 50 占 폚 / hour, was 104 占 폚.

&Lt; Examples 1 to 6, Comparative Examples 1 to 6 >

Styrene resin (A) and transparent resin (B) were melt-kneaded in the form shown in Table 1 using an extruder to obtain a resin composition. In Examples 1 to 6, the styrene resin (A) and the transparent resin (B) were supplied to the extruder using separate quantitative feeders. The supply amount of the transparent resin B was set to 15 kg / hr in Examples 1 to 3, 19 kg / hr in Example 4, 10 kg / hr in Example 5 and 15 kg / hr in Example 6, ) Was controlled so as to be the mixing ratio shown in Table 1 (the total amount supplied was 20 kg / hr). The quantitative feeder used was a Ross in weight type feeder (CE-W-1 manufactured by Kubota Corporation). In Comparative Examples 1 to 6, the pellets of the styrene type resin (A) and the transparent resin (B) were dry blended at a blending ratio shown in Table 1, and then fed to the extruder using the same feeder. The supply amount of the dry blended pellets was set at 20 kg / hr. The extruder used was a twin-screw extruder (TEM-26SX manufactured by Toshiba Kiki K.K.), the cylinder temperature was set at 240 ° C, and the screw rotation number was set at 250 rpm. After melt-kneading in an extruder, the mixture was extruded from a porous die into a strand shape, and a pellet-shaped resin composition was obtained by a cold-cut method. The resin composition obtained was evaluated as follows. The evaluation results are shown in Table 1.

(Vicat softening point)

The Vicat softening point was measured using a test piece having a size of 10 mm x 10 mm and a thickness of 4 mm in accordance with the method 50 (load: 50 N, temperature raising rate: 50 DEG C / hour) based on JIS K7206: 1999. In addition, the measuring instrument was an HDT & VSPT tester manufactured by Toyo Seiki Seisakusho Co., Ltd.

(Total light transmittance, Haze)

The total light transmittance and haze were measured using an injection molding machine (IS-50EPN manufactured by Toshiba Kikai K.K.) at a cylinder temperature of 240 DEG C and a mold temperature of 70 DEG C, Mm was measured using a haze meter (NDH-1001DP type, manufactured by Nippon Denshoku Kogyo K.K.) in accordance with ASTM D1003.

(Presence of defective appearance)

A mirror-finished plate having a length of 127 mm, a width of 127 mm and a thickness of 6 mm was molded under the molding conditions of a cylinder temperature of 250 占 폚 and a mold temperature of 70 占 폚 by using an injection molding machine (J140AD-180H manufactured by Nippon Seiko Co., Ltd.) And the presence or absence of defective appearance was confirmed.

In the examples in which the styrene type resin (A) and the transparent resin (B) are separately fed, there is no defective external appearance in appearance, and the appearance, transparency and heat resistance are excellent. On the other hand, in the comparative example in which the dry blend was fed in a batch, appearance defects such as shaking appearance occurred.

INDUSTRIAL APPLICABILITY The resin composition of the present invention is transparent, excellent in appearance, and excellent in heat resistance, so that it is useful for components of home appliances, automobile parts, building materials, optical members, food containers and the like. Particularly, since there is no defective appearance in injection molding, it can be suitably used.

Claims (11)

(A) containing a copolymer containing an unsaturated dicarboxylic acid anhydride monomer unit and a transparent resin (B) other than the styrene series resin (A), wherein the styrene resin , A total light transmittance of 2 mm in thickness of 88% or more, and a haze of 0.3% or less. 2. The thermoplastic resin composition according to claim 1, wherein the styrene-based resin (A) comprises a styrene-based monomer unit in an amount of 45 to 90 mass%, an unsaturated dicarboxylic acid anhydride monomer unit, a (meth) And 10 to 55 mass% of at least one monomer unit selected from other vinyl monomer units copolymerizable therewith. The positive resist composition according to claim 1 or 2, wherein the transparent resin (B) comprises at least one member selected from a methacrylic resin, a methyl methacrylate-styrene copolymer and a styrene-acrylonitrile copolymer . The resin composition according to any one of claims 1 to 3, wherein the content of the styrene resin (A) is 5 to 50 mass% and the content of the transparent resin (B) is 95 to 50 mass%. The styrene resin (A) according to any one of claims 1 to 4, wherein the styrene type resin (A) has a Vicat softening temperature of 110 占 폚 or higher determined by a load of 50 N and a heating rate of 50 占 폚 / hour according to JIS K7206 Composition. A molded article obtained by injection molding the resin composition according to any one of claims 1 to 5. A styrene resin (A) containing a copolymer containing an unsaturated dicarboxylic acid anhydride monomer unit and a transparent resin (B) other than the styrene resin (A) are separately fed to an extruder And melt-kneading the resin composition. 8. The thermoplastic resin composition according to claim 7, wherein the styrene-based resin (A) comprises a styrene-based monomer unit in an amount of 45 to 90 mass%, an unsaturated dicarboxylic acid anhydride monomer unit, a (meth) And 10 to 55% by mass of at least one monomer unit selected from other vinyl monomer units copolymerizable therewith. The positive photosensitive resin composition according to claim 7 or 8, wherein the transparent resin (B) comprises at least one selected from methacrylic resin, methyl methacrylate-styrene copolymer and styrene- acrylonitrile copolymer By weight based on the total weight of the resin composition. 10. The resin composition according to any one of claims 7 to 9, wherein the content of the styrene resin (A) is 5 to 50 mass% and the content of the transparent resin (B) is 95 to 50 mass% Gt; The styrene resin (A) according to any one of claims 7 to 10, wherein the styrene type resin (A) has a Vicat softening temperature of 110 캜 or higher, which is determined by a load of 50 N and a temperature raising rate of 50 캜 / hour according to JIS K7206 &Lt; / RTI &gt;