JP4458931B2 - Transparent rubber-modified copolymer resin composition, molded product obtained therefrom, and method for producing the composition - Google Patents

Description

  The present invention relates to a rubber-modified copolymer resin composition excellent in transparency, hue, and practical strength, a molded product obtained therefrom, and a method for producing the composition.

  The transparent rubber-modified copolymer resin obtained by copolymerizing a styrene monomer and a (meth) acrylic acid ester monomer in the presence of a rubbery polymer has transparency and impact resistance. Various studies have been made to achieve the balance. For example, it has been reported that optical transparency is dramatically improved by using lower alkyl methacrylate and higher alkyl methacrylate as two or more kinds of (meth) acrylic acid ester monomers (for example, (See Patent Document 1). In addition, a rubber-modified copolymer resin composition excellent in transparency and impact resistance can be obtained by using a specific rubber-like polymer and adjusting the toluene swelling index and the toluene insoluble content / swelling index ratio within a specific range. It is reported that it can be obtained (see, for example, Patent Document 2).

On the other hand, by adding a specific stabilizer to a block copolymer composed of a specific monoalkenyl aromatic compound and a conjugated diene compound, a heat-stabilized block copolymer composition having excellent heat stability and discoloration resistance is obtained. It has been reported that it can be obtained (see, for example, Patent Document 3).
JP-A-52-124095 JP-A-6-16744 Japanese Patent Laid-Open No. 2001-234022

  However, these resin compositions have practical strength in applications in practical fields such as thick molded products, although the molded products obtained from them can be improved in terms of transparency and impact resistance. Was still low. For this reason, these resin compositions have the disadvantages that their use is limited and the commercial value of the resin molded product is lost as compared with transparent ABS (acrylonitrile-butadiene-styrene) resin, polycarbonate resin and the like. It was.

  Recently, several methods for producing transparent rubber-modified copolymer resins with improved practical strength have been reported. However, a rubber-modified copolymer resin having sufficient transparency and productivity has not been obtained yet. In addition, when copolymerizing a styrene monomer and a (meth) acrylate monomer in the presence of a rubbery polymer, the type and amount of the anti-aging agent added to the rubbery polymer In some cases, the radical polymerization reaction is inhibited, the polymerization rate is lowered, and the productivity is lowered. Furthermore, even if it does not contain an anti-aging agent, or contains an anti-aging agent, depending on the type and amount, when the rubber-modified copolymer resin is molded, the molded product is colored yellow and the hue is extremely high. In addition, there is a defect that irregularities called fish eyes are generated on the surface of the molded body due to abnormal crosslinking of the rubber-like polymer due to the heat history during the molding process.

  In view of the above circumstances, an object of the present invention is to provide a rubber-modified copolymer resin composition excellent in transparency, hue, and practical strength, a molded product obtained therefrom, and a method for producing the composition. .

  The present inventors have intensively studied to solve the above-mentioned problems. As a result, a rubber-like polymer containing a specific anti-aging agent is used, and the volume average particle diameter of rubber particles dispersed in the resin, the rubber-like polymer is used. The rubber-modified copolymer resin composition in which the difference between the refractive index of the polymer and the refractive index of the continuous phase and the swelling index due to toluene are in a specific range, and the total amount of monomers remaining in the resin is not more than a specific value. I found that I can achieve. Further, it has been found that such a rubber-modified copolymer resin composition with a small amount of remaining monomer can be obtained by a specific production method, and the present invention has been completed based on these findings.

（式中、Ｒ₁及びＲ₃は−ＣＨ₂−Ｓ−Ｒ₅（Ｒ₅は炭素数１〜１８を有するアルキル基を表す）を表し、Ｒ₂は水素原子又はメチル基を表し、Ｒ₄は炭素数１〜８を有するアルキル基又は炭素数５〜１２を有するシクロアルキル基を表す）
で表される老化防止剤０．０２〜０．３質量％を含有するスチレン−ブタジエン系ランダム共重合体ゴムの存在下に、スチレン系単量体と、（メタ）アクリル酸エステル系単量体とをスチレン系単量体対（メタ）アクリル酸エステル系単量体の比１〜９９質量部：９９〜１質量部（スチレン系単量体と、（メタ）アクリル酸エステル系単量体との合計を１００質量部とする）で単量体の合計１００質量部に対してスチレン−ブタジエン系ランダム共重合体ゴム０．１〜３０質量部の割合で共重合させて得られるゴム変性共重合樹脂であって、樹脂中に分散するゴム粒子の体積平均粒子径（ｄｖ）が０．４〜１．６μｍであり、温度２５℃における前記共重合体ゴムの屈折率とスチレン系単量体と、（メタ）アクリル酸エステル系単量体とを共重合させてなる連続相の屈折率との差が０．００３以下であり、２５℃でのトルエンによる膨潤指数が５〜１１であり、樹脂中に残存する単量体の合計が質量により７００ｐｐｍ以下であるゴム変性共重合樹脂組成物を成形してなる成形物であって、射出成形された厚さ２ｍｍのプレートが全光線透過率８５％以上、曇価４％以下を有する成形物。
２．前記スチレン−ブタジエン系ランダム共重合体ゴムが、スチレン単量体単位３２〜４５質量％から成る共重合体である上記１記載の成形物。
３．前記スチレン系単量体がスチレンであり、（メタ）アクリル酸エステル系単量体がメチルメタクリレートとｎ−ブチルアクリレートである上記１又は２記載の成形物。
４．前記老化防止剤が２，４−ビス［（オクチルチオ）メチル］−Ｏ−クレゾールである上記１〜３のいずれか一に記載の成形物。
５．射出成形された厚さ２ｍｍのプレートが色相２．０未満を有する上記１〜４いずれか一に記載の成形物。
６． 下記の一般式（１）：

（式中、Ｒ₁及びＲ₃は−ＣＨ₂−Ｓ−Ｒ₅（Ｒ₅は炭素数１〜１８を有するアルキル基を表す）を表し、Ｒ₂は水素原子又はメチル基を表し、Ｒ₄は炭素数１〜８を有するアルキル基又は炭素数５〜１２を有するシクロアルキル基を表す）
で表される老化防止剤をスチレン−ブタジエン系ランダム共重合体ゴムに配合し、該老化防止剤を配合したスチレン−ブタジエン系ランダム共重合体ゴムの存在下に、スチレン系単量体と、（メタ）アクリル酸エステル系単量体とを溶液又は塊状で樹脂率が６０〜９５質量％になるように共重合させた後に、直列につないだ２基以上の脱揮槽に導入して揮発分を除去して樹脂組成物中に残存する単量体の量を低減させるに際し、脱揮槽を、第一段で温度１５０〜２００℃、圧力１００ｋＰａ以下で作動させ、第二段で温度２２０〜２６０℃、圧力７ｋＰａ以下で作動させ、樹脂組成物中に残存する単量体の合計量を質量により７００ｐｐｍ以下にするゴム変性共重合樹脂組成物の製造方法。
７．前記老化防止剤が２，４−ビス［（オクチルチオ）メチル］−Ｏ−クレゾールである上記６記載の製造方法。
Thus, according to the present invention, the following inventions 1 to 7 are provided.
1. Under Symbol of the general formula (1):

Wherein R ₁ and R ₃ represent —CH ₂ —S—R ₅ (R ₅ represents an alkyl group having 1 to 18 carbon atoms), R ₂ represents a hydrogen atom or a methyl group, R ₄ Represents an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms)
In the presence of a styrene-butadiene random copolymer rubber containing 0.02 to 0.3% by mass of an antioxidant represented by the formula (1), a styrene monomer and a (meth) acrylic acid ester monomer preparative styrene monomer to the (meth) ratio 1-99 parts by weight of acrylic acid ester monomer: 99-1 parts by weight of (styrene monomer, and (meth) acrylic acid ester monomer butadiene random copolymer rubber 0.1 to 30 parts by weight of the rubber-modified copolymer obtained by copolymerizing at a rate of polymerization - total styrene per 100 parts by weight of the monomer in which) and 100 parts by weight of The volume average particle diameter (dv) of the rubber particles dispersed in the resin is 0.4 to 1.6 μm, and the refractive index of the copolymer rubber and the styrenic monomer at a temperature of 25 ° C. , (meth) co acrylic acid ester monomer The difference from the refractive index of the combined continuous phase is 0.003 or less, the swelling index by toluene at 25 ° C. is 5 to 11, and the total of the monomers remaining in the resin is 700 ppm or less by mass A molded product obtained by molding a rubber-modified copolymer resin composition , wherein the injection-molded plate having a thickness of 2 mm has a total light transmittance of 85% or more and a haze value of 4% or less .
2 . 2. The molded article according to 1 above, wherein the styrene-butadiene random copolymer rubber is a copolymer composed of 32 to 45% by mass of a styrene monomer unit.
3 . 3. The molded article according to 1 or 2 above, wherein the styrene monomer is styrene and the (meth) acrylic acid ester monomer is methyl methacrylate and n-butyl acrylate.
4. The molded article according to any one of the above 1 to 3, wherein the anti-aging agent is 2,4-bis [(octylthio) methyl] -O-cresol.
5 . Molded article according to the fourth any one having a plate less than Hue 2.0 thick 2mm injection molded.
6 . The following general formula (1):

Wherein R ₁ and R ₃ represent —CH ₂ —S—R ₅ (R ₅ represents an alkyl group having 1 to 18 carbon atoms), R ₂ represents a hydrogen atom or a methyl group, R ₄ Represents an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms)
Is blended with a styrene-butadiene random copolymer rubber , and in the presence of the styrene- butadiene random copolymer rubber blended with the antioxidant, a styrene monomer and ( after the resin rate is copolymerized so as to 60 to 95% by mass meth) acrylic acid ester monomer solution or bulk, volatiles were introduced into 2 groups or more devolatilizing tank by connecting in series When the amount of the monomer remaining in the resin composition is reduced by removing the devolatilization tank , the devolatilization tank is operated at a temperature of 150 to 200 ° C. and a pressure of 100 kPa or less at the first stage, and at a temperature of 220 to 200 at the second stage. 260 ° C., is operated below a pressure 7 kPa, the manufacturing method of the rubber-modified copolymer resin composition to below 700ppm by total weight of the mass of the monomer remaining in the resin composition.
7 . The production method according to 6 above, wherein the anti-aging agent is 2,4-bis [(octylthio) methyl] -O-cresol.

  The rubber-modified copolymer resin composition of the present invention has excellent transparency such that an injection molded plate having a thickness of 2 mm has a total light transmittance of 85% or more and a haze of 4% or less as measured in accordance with JIS K7105. In addition, the hue measured in accordance with JIS K7105 is less than 2.0, there is no discoloration during processing and molding, and the balance of practical properties such as impact strength, fluidity and practical strength is excellent. Further, the rubber-modified copolymer resin composition of the present invention has a small amount of monomer remaining after polymerization, and can appropriately crosslink the rubber-like polymer, and the rubber-like polymer becomes abnormal due to its thermal history. Fish eyes generated by crosslinking are not generated, and the productivity is excellent. Furthermore, the rubber-modified copolymer resin composition of the present invention can be easily produced by using a rubbery polymer containing a specific anti-aging agent and using two or more devolatilization tanks.

The present invention is described in detail below.
The rubber-modified copolymer resin composition of the present invention comprises a styrenic monomer, a (meth) acrylic acid ester monomer, and optionally other styrene monomers in the presence of a rubbery polymer containing an antioxidant. A transparent rubber-modified copolymer resin obtained by copolymerizing with a monomer, in which a styrene monomer, a (meth) acrylate monomer, and optionally other monomers Rubber particles are dispersed in a continuous phase obtained by copolymerization of

  In the present invention, it is preferable to use a diene polymer as the rubber-like polymer. Examples of the diene polymer include polybutadiene, styrene-butadiene rubber, styrene-butadiene block rubber, partially hydrogenated polybutadiene, partially hydrogenated styrene-butadiene rubber, and partially hydrogenated styrene-butadiene block rubber. -Butadiene rubber and styrene-butadiene block rubber are preferred.

  The rubbery polymer preferably has a 5% by mass styrene solution viscosity at a temperature of 25 ° C. of 15 to 60 mPa · s, and more preferably has a 5% by mass styrene solution viscosity at 25 ° C. of 20 to 40 mPa · s.

  The rubber-like polymer preferably has a 1,2-vinyl bond ratio of 16 mol% or less of unsaturated bonds based on butadiene, more preferably 10-14 mol%.

  The styrene-butadiene rubber or styrene-butadiene block rubber contains 32 to 45% by mass of a styrene monomer unit.

  The rubber-like polymer used in the present invention can contain a polymer other than the diene polymer in an amount less than 50 parts by mass with respect to 100 parts by mass of the rubber-like polymer.

（式中、Ｒ₁及びＲ₃は−ＣＨ₂−Ｓ−Ｒ₅（Ｒ₅は炭素数１〜１８を有するアルキル基、好ましくはｎ−オクチル又はｎ−ドデシル基を表す）を表し、Ｒ₂は水素原子又はメチル基を表し、Ｒ₄がメチル基と異なる基を表す時は、メチル基を表し、Ｒ₄は炭素数１〜８を有するアルキル基、例えばメチル、エチル、ｎ−ブチル、ｓｅｃ−ブチル、ｔ−ブチル基等、好ましくはメチル、ｔ−ブチル基又は炭素数５〜１２を有するシクロアルキル基、例えばシクロペンチル、シクロヘキシル、シクロヘプチル、シクロオキシル基等、好ましくはシクロヘキシル基を表す）
で表される老化防止剤を含有する。 The rubbery polymer used in the present invention has the following general formula (1):

Wherein R ₁ and R ₃ represent —CH ₂ —S—R ₅ (R ₅ represents an alkyl group having 1 to 18 carbon atoms, preferably n-octyl or n-dodecyl group), and R ₂ Represents a hydrogen atom or a methyl group, and when R ₄ represents a group different from a methyl group, it represents a methyl group, and R ₄ represents an alkyl group having 1 to 8 carbon atoms, such as methyl, ethyl, n-butyl, sec -Butyl, t-butyl group, etc., preferably methyl, t-butyl group or a cycloalkyl group having 5 to 12 carbon atoms, such as cyclopentyl, cyclohexyl, cycloheptyl, cyclohexyl group, etc., preferably cyclohexyl group)
It contains an anti-aging agent represented by

  Specific examples of the antioxidant include 2,4-bis [(octylthio) methyl] -O-cresol, 2,4-bis [(dodecylthio) methyl] -O-cresol, 2,4-bis [(phenylthio). And methyl] -3-methyl-6-t-butylphenol. Among them, 2,4-bis [(octylthio) methyl] -O-cresol is preferable.

  The anti-aging agent is in the range of 0.02 to 0.3% by mass, preferably 0.06 to 0.15% by mass, more preferably 0.08 to 0.12% by mass, based on the rubber-like polymer. Blend. When the blending amount of the antioxidant is less than 0.02% by mass with respect to the rubber-like polymer, the swelling index of the rubber-modified copolymer resin composition with toluene can be lowered, and the resulting molded product is inferior in hue. On the other hand, if the blending amount of the anti-aging agent is more than 0.3% by mass relative to the rubber-like polymer, the swelling index of the rubber-modified copolymer resin composition with toluene can be increased, and the molded product has transparency and Inferior in practical strength.

  Examples of the styrenic monomer used in the present invention include styrene, α-methyl styrene, p-methyl styrene, pt-butyl styrene, etc. Among them, styrene is preferable. These styrene monomers may be used alone or in combination of two or more.

  Examples of the (meth) acrylic acid ester monomer used in the present invention include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-methylhexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, methyl acrylate, ethyl acrylate, n -Butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate and the like can be mentioned, and among them, methyl methacrylate and n-butyl acrylate are preferable. These (meth) acrylic acid ester monomers may be used alone or in combination of two or more.

  Examples of other monomers copolymerizable with the styrene monomer and (meth) acrylate monomer used in the present invention include acrylonitrile, n-butyl acrylate, methacrylic acid, maleic anhydride, and the like. Of these, n-butyl acrylate is preferred.

  The proportion of styrene monomer, (meth) acrylic acid ester monomer, and optionally other monomers used is optional for styrene monomer vs. (meth) acrylic acid ester monomer 1 to 99 parts by mass: 99 to 1 part by mass: 0 to 10 parts by mass (styrene monomer and (meth) acrylic acid ester monomer, optionally The total amount with other monomers is 100 parts by mass), preferably 5 to 95 parts by mass: 95 to 5 parts by mass: 0 to 5 parts by mass.

  The rubber-like polymer in the rubber-modified copolymer resin composition of the present invention is based on a total of 100 parts by mass of a styrene monomer, a (meth) acrylic acid ester monomer, and other monomers. The ratio of 0.1 to 30 parts by mass is preferable because a molded article having an excellent balance between transparency and impact resistance can be obtained. When the rubber-like polymer is used at a ratio of 3 to 15 parts by mass with respect to 100 parts by mass of the total amount of monomers, a molded product having a further excellent balance between transparency and impact resistance can be obtained. .

In the rubber-modified copolymer resin composition of the present invention, the rubber particles dispersed in the continuous phase have a volume average particle diameter (dv) in the range of 0.4 to 1.6 μm, preferably in the range of 0.4 to 1.3 μm. More preferably, it is in the range of 0.5 to 1.2 μm. When the volume average particle diameter (dv) of the rubber particles is smaller than 0.4 μm, the resulting molded product is inferior in hue and practical strength, while the volume average particle diameter (dv) of the rubber particles is larger than 1.6 μm. The molded product is inferior in transparency.
The rubber particles are formed as the polymerization proceeds when the monomers are copolymerized in the presence of the rubber-like polymer. The volume average particle diameter (dv) of the rubber particles can be adjusted by changing the magnitude of the shear stress applied to the rubber particles by stirring during polymerization and the addition amount of a polymerization initiator or a molecular weight modifier. The volume average particle diameter (dv) can also be adjusted by mixing rubber-modified copolymer resins having different particle diameters.

In the present invention, the refractive index of a rubber-like polymer at a temperature of 25 ° C., a styrene monomer, a (meth) acrylate monomer, and optionally other monomers are copolymerized. It is necessary to make the difference from the refractive index of the continuous phase as small as possible, preferably 0.003 or less. When the difference in refractive index exceeds 0.003, the resulting molded product is inferior in transparency. Such a difference in refractive index can be made within the intended range by appropriately adjusting the type of rubbery polymer used, the particle diameter thereof, and the type and amount of monomer used.
In the present invention, the refractive index of the rubber-like polymer is a value measured at a temperature of 25 ° C. by preparing a test piece having a thickness of 0.5 mm using a press molding machine. The refractive index of the continuous phase was determined by dissolving the rubber-modified copolymer resin composition in methyl ethyl ketone (MEK) at a temperature of 25 ° C. for 24 hours, and then centrifuging at a temperature of 10 ° C. or lower and 24,000 rpm for 40 minutes. It is the value measured after concentration.

  The rubber-modified copolymer resin composition of the present invention has a polystyrene-equivalent weight average molecular weight (Mw) measured by GPC (gel permeation chromatography) method of 70,000 to 500,000, preferably 100,000 to 400,000. More preferably, it is 120,000 to less than 250,000, and particularly preferably 130,000 to less than 160,000. When the weight average molecular weight (Mw) is less than 70,000 or more than 500,000, the rubber-modified copolymer resin composition may have a defect such as an increase in yellowness of the molded product during molding. Adjustment of a weight average molecular weight (Mw) can be adjusted with the temperature at the time of superposition | polymerization, a molecular weight modifier, etc.

  The rubber-modified copolymer resin composition of the present invention has a melt mass flow rate (MFR) measured in accordance with JIS K7210 of 3.5 to 20 g / 10 minutes, preferably 3.6 to 12 g / 10 minutes, more preferably Is 3.7 to 10 g / 10 min. When the melt mass flow rate (MFR) is less than 3.5, transparency during low temperature molding and practical impact resistance are lowered. On the other hand, when the melt mass flow rate (MFR) exceeds 20 g / 10 minutes, the impact resistance is lowered. The melt mass flow rate (MFR) can be adjusted by the type and amount of (meth) acrylic acid ester, the initiator used during polymerization, the molecular weight adjusting agent, and the like.

  Furthermore, the rubber-modified copolymer resin composition of the present invention has a swelling index of 5 to 11, preferably 7 to 11, and more preferably 8 to 10. When the swelling index is less than 5, the resulting molded product is inferior in hue, and when the swelling index exceeds 11, the obtained molded product is increased in haze and inferior in transparency and in practical strength. The swelling index can be adjusted by the addition amount of an anti-aging agent contained in the rubber-like polymer, the heating conditions in the devolatilization tank, and the like.

  In the rubber-modified copolymer resin composition of the present invention, the total of the styrene monomer, (meth) acrylic acid ester monomer, and other monomers remaining in the resin composition is 700 ppm or less by mass. , Preferably 500 ppm or less, more preferably 300 ppm or less. If the total amount of monomers remaining in the resin composition exceeds 700 ppm, the resulting molded product is inferior in hue and causes odor during molding.

  The amount of unreacted monomer remaining in the resin composition is generally determined by lowering the pressure in the devolatilization tank when the resin composition is passed through the devolatilization tank and the monomer is devolatilized together with the solvent. And can be reduced by raising the temperature. However, when the reaction solution is exposed to such severe conditions for a long time, not only the polymer once generated is degraded and the productivity is deteriorated, but also the hue of the molded product obtained from the resin composition, etc. It will cause deterioration of properties. Therefore, in the present invention, two or more devolatilization tanks are connected in series, and most of the monomer and solvent are removed from the reaction solution by devolatilization under mild conditions in the first stage. In order to further devolatilize and remove the monomer and solvent in the tank, the time for exposing the reaction solution to harsh conditions is shortened. According to the present invention, the total amount of monomers and solvent remaining in the rubber-modified copolymer resin composition without reducing the productivity of the desired rubber-modified copolymer resin composition and without causing deterioration of the properties of the molded product. The amount can be sufficiently reduced.

  The rubber-modified copolymer resin composition of the present invention has an excellent hue because the b value (b1) representing the hue of a 2 mm thick plate molded at a mold temperature of 40 ° C. and a cylinder temperature of 230 ° C. is small. To preferred. In the present invention, the range of the b value (b1) of the molded product is not particularly limited, but is preferably less than 2.0, more preferably less than 1.8, and particularly preferably 1.5 or less. If the b1 value is 2.00 or more, the yellowishness of the molded product is strong and the hue is inferior.

  The rubber-modified copolymer resin composition of the present invention comprises a styrenic monomer, a (meth) acrylic acid ester monomer, and optionally other styrene monomers in the presence of a rubbery polymer containing an antioxidant. It can be produced by copolymerizing with a monomer. In the present invention, the copolymerization method may be a known method such as solution polymerization, bulk polymerization, suspension polymerization, etc., and may be carried out by any of batch polymerization method and continuous polymerization method. In particular, block polymerization in which the monomer is copolymerized in the form of a solution or block in the presence of a rubber-like polymer, and then the resulting copolymer is passed through a devolatilizing preheater / devolatilizing tank and exposed to high temperatures. Alternatively, the continuous polymerization method of solution polymerization is preferable because the rubber-modified copolymer resin composition can be efficiently produced.

Below, the preferable process for manufacturing the rubber-modified copolymer resin composition of this invention is demonstrated concretely.
The rubber-like polymer is blended with the amount of anti-aging agent specified above, and the rubber-like polymer containing the anti-aging agent is mixed with a styrene monomer, a (meth) acrylic acid ester monomer, optionally The other monomer, if necessary, a polymerization solvent is added to dissolve the rubber-like polymer, and a polymerization initiator is added to this as necessary, and the resulting solution is supplied to a stirred reactor. In a stirring reactor, polymerization is advanced with sufficient stirring, the polymer composition is made uniform, and rubber particles are refined to obtain a desired particle size. Further, the polymerization conditions such as temperature can be determined in consideration of the fluidity and productivity of the rubber-modified copolymer resin, the heat removal capability of the reactor, and the like.

Next, the polymerization solution exiting the stirring type reactor is introduced into a plug flow type tower type or tube type reactor, and the reaction is further advanced without adding external stirring, so that the resin ratio is 60 to 95% by mass, preferably 70%. It is copolymerized so that it may become -95 mass%, More preferably, it is 75-85 mass%. When the resin ratio is lower than 70%, the production efficiency is poor. On the other hand, when the resin ratio is higher than 95%, the viscosity of the polymerization solution becomes high and transportation becomes difficult. The resin ratio in the present invention was determined as follows: about 3 g of the polymer solution was dissolved in about 30 g of toluene, and this was dropped into about 400 g of methanol to precipitate a solid, which was filtered with No. 5A filter paper. After that, the solid matter remaining on the filter paper is dried in a hot air dryer at a temperature of 70 ° C. for 4 hours to determine the mass of the solid matter. The mass of the obtained solid after drying was calculated from the following formula as the amount of resin in the polymerization solution:
Resin ratio = (mass of solid / mass of polymerization solution) × 100

  If necessary, one or more stirring reactors and plug flow reactors may be used.

  The polymerization solvent added to the raw material as necessary is added for the purpose of reducing the viscosity of the raw material solution in the reactor. As the solvent, toluene, ethylbenzene, xylene, and the like are suitable, and the amount used can be appropriately determined so that a favorable progress of the reaction can be obtained.

  In the present invention, it is preferable to add a polymerization initiator in order to accelerate the polymerization reaction rate. As the polymerization initiator, a known azo compound or a known organic peroxide can be used. Specific examples of the azo compound include azobisisobutyronitrile and azobiscyclohexanecarbonitrile. The organic peroxide preferably has a one-hour half-life temperature of 90 to 130 ° C. Specific examples of the organic peroxide include benzoyl peroxide, t-butylperoxybenzoate, 1,1-bis (t- Butylperoxy) -3,3,5-trimethylcyclohexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexanoate, di-t-butyl peroxide, dicumyl peroxide, ethyl -3,3-di- (t-butylperoxy) butyrate and the like.

  The polymerization initiator is 0.005 to 0.5 parts by mass with respect to a total of 100 parts by mass of the styrene monomer, the (meth) acrylic acid ester monomer, and other monomers, preferably Add 0.02-0.1 parts by weight. When the addition amount of the polymerization initiator is less than 0.005 parts by mass with respect to 100 parts by mass in total of the monomers, the polymerization reaction rate cannot be promoted, and the other is more than 0.5 parts by mass. Then, the polymerization reaction rate becomes too fast and it becomes difficult to control the polymerization reaction. These organic peroxides may be used alone or in combination of two or more.

Moreover, it is preferable to add well-known molecular weight modifiers, such as 4-methyl-2,4-diphenyl pentene-1, t-dodecyl mercaptan, n-dodecyl mercaptan, at the time of superposition | polymerization.
The addition amount of the molecular weight modifier is preferably 0.005 to 5 mass with respect to a total of 100 mass parts of the styrene monomer, the (meth) acrylic acid ester monomer, and the other monomers. Part, more preferably in the range of 0.01 to 1 part by mass. When the addition amount of the molecular weight modifier is less than 0.005 parts by mass or more than 5 parts by mass with respect to 100 parts by mass, the purpose of adjusting the molecular weight of the obtained copolymer is not achieved. There is a case.

  If necessary, an antioxidant can be added to the raw material solution, during the polymerization, or at the end of the polymerization, preferably to the raw material solution. Antioxidants include octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionate, 2,4-dimethyl-6- (1-methylpentadecyl) phenol, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-a, a ′, a ′ '-(Mesitylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl -4-hydroxy-m-tolyl) propionate, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3,5-triazi -2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6-bis (octylthio) -1,3,5-triazin-2-ylamino) Known antioxidants such as phenol can be mentioned, and among them, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate is preferable.

  The addition amount of the antioxidant is preferably 0.05 to 5 parts by mass, more preferably 100 parts by mass with respect to the total of 100 parts by mass of the styrene monomer, the (meth) acrylate monomer and other monomers. Is in the range of 0.1 to 1 part by mass. When no hindered phenolic antioxidant is added during polymerization or when an antioxidant other than the hindered phenolic antioxidant is used, the hindered phenolic antioxidant is further added to 100 parts by mass of the monomer. On the other hand, when adding more than 1 mass part, the yellowishness of resin may increase or recyclability may become low, and may be unpreferable.

  Next, the reaction solution exiting the plug flow reactor is passed through a devolatilization tank for the purpose of removing unreacted monomers and solvents. According to the present invention, devolatilization is performed in multiple stages using two or more devolatilization tanks. That is, when the reaction solution is passed through the devolatilization tank, the total amount of monomers remaining in the resin composition in the first stage is 150,000 ppm or less, preferably 100,000 ppm or less, more preferably 70,000 ppm by mass. Below. Next, as the second stage, the resin composition from which the monomer and solvent have been removed in the first stage is passed through a devolatilization tank for the purpose of further removing the monomer and solvent, and the single resin remaining in the resin composition. The total amount of the monomer is 700 ppm or less, preferably 500 ppm or less, more preferably 300 ppm or less by mass. In the first stage, the devolatilization tank is preferably operated under conditions of a resin temperature of 150 to 200 ° C. and a pressure of 100 kPa or less, and is operated under conditions of a resin temperature of 160 to 190 ° C. and a pressure of 90 kPa or less. More preferred. In the second stage, the devolatilization tank is preferably operated under conditions of a resin temperature of 220 to 260 ° C. and a pressure of 7 kPa or less, and is operated under conditions of a resin temperature of 240 to 250 ° C. and a pressure of 2 kPa or less. More preferred. In the second stage, when the resin temperature is lower than 220 ° C., the molded article of the rubber-modified copolymer resin composition obtained by increasing the swelling index of the rubber-modified copolymer resin composition is inferior in haze and practical strength. On the other hand, when the resin temperature is higher than 260 ° C., the molded product of the rubber-modified copolymer resin composition obtained by decomposing the produced copolymer and increasing the amount of the monomer remaining in the resin, Inferior in hue. When devolatilization is performed in two or more stages, it is preferable to perform devolatilization within the above-described conditions.

  The rubber-modified copolymer resin composition of the present invention is obtained by extracting the product from the devolatilization tank and making it into pellets, chips, powders and the like as necessary.

  In the rubber-modified copolymer resin composition of the present invention, additives such as weathering agents, lubricants, plasticizers, colorants, antistatic agents, mineral oils, flame retardants and the like can be added as necessary. It can mix | blend in the step of.

  The rubber-modified copolymer resin composition of the present invention can be processed into various molded articles such as films and sheets by a known method such as injection molding, extrusion molding, compression molding, vacuum molding and the like, and can be put to practical use. If necessary, the rubber-modified copolymer resin composition of the present invention includes an ABS graft product, MBS (methyl methacrylate-styrene-butadiene) graft product, SBS (styrene-butadiene-styrene) copolymer, polycarbonate, polyamide. In addition, other resins such as polyester can be used by melt-kneading.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.

（ｎiは粒子径Ｄiを有するゴム粒子の個数の割合である）
（４）ゴム変性共重合樹脂組成物の重量平均分子量（Ｍｗ）は、下記に記載する通りのＧＰＣ測定条件で測定した：
装置名：ＳＹＳＴＥＭ−２１ Ｓｈｏｄｅｘ（昭和電工社製）
カラム：ＰＬ ｇｅｌ ＭＩＸＥＤ−Ｂを３本直列
温度：４０℃
検出：示差屈折率
溶媒：テトラハイドロフラン
濃度：２質量％
検量線：標準ポリスチレン（ＰＳ）（ＰＬ社製）を用いて作製し、重量平均分子量はＰＳ換算値で表した。
（５）透明性
東芝機械（株）社製射出成形機（ＩＳ−５０ＥＰＮ）を用いて、金型温度６０℃、シリンダー温度２３０℃で厚さ２ｍｍのプレートを成形した。この成形品を用い、透明性の尺度としてＪＩＳ Ｋ７１０５に準拠し、全光線透過率および曇り度を測定した（単位：％）。なお、測定機は、日本電色工業社製ＨＡＺＥメーター（ＮＤＨ−１００１ＤＰ型）を用いた。全光線透過率が８５％以上、曇り度が４％以下を合格とした。
（６）色相
東芝機械（株）社製射出成形機（ＩＳ−５０ＥＰＮ）を用いて、金型温度６０℃、シリンダー温度２３０℃で厚さ２ｍｍのプレートを成形した。この成形品を用い、色差の尺度としてＪＩＳ Ｋ７１０５に準拠して、日本電色工業社製色差計（Σ８０）を用いてｂ値を測定した（単位：−）。このｂ値は、成形品の色相、青色味と黄色味を表すもので、ＪＩＳ Ｋ７１０５に準拠してハンターダイアグラムにおけるｂ値を採用する。
（７）屈折率
ゴム状重合体の屈折率：プレス成形機を用いて厚さ０．５ｍｍの試験片を作製して、ディジタル屈折率計ＲＸ−２０００（アタゴ（株）社製）を用いて温度２５℃で測定した。なお、接触液はヨウ化水銀カリウム飽和水溶液を使用した。
連続相の屈折率：試料０．３５ｇを精秤（ａ）し、これをメチルエチルケトン（ＭＥＫ）３５ｍｌに温度２５℃で２４時間かけて溶解させた後に、溶解液を事前に質量（ｂ）を測定した容量５０ｍｌの遠心管に移し、最大遠心半径１０．７ｃｍのローターを用いて、温度１０℃以下、２４０００ｒｐｍで４０分間遠心分離し、上澄み液を濃縮して屈折率を測定した（測定器：エルモ社製 形式：Ｎｏ１６１０１ アッベ屈折計）。
（８）実用強度
（５）で成形した厚さ２ｍｍのプレートを用いて評価した。ＪＩＳ Ｋ７２１１に準拠し、５０％破壊エネルギーを測定した（単位：ｋｇ・ｃｍ）。
（９）メルトマスフローレート（ＭＦＲ）
ゴム変性共重合樹脂組成物のメルトマスフローレート（ＭＦＲ）は、ＪＩＳ Ｋ７２１０に準拠し、温度２３０℃、荷重２．１６ｋｇにおいて測定した。 In the examples, the evaluation was as follows.
(1) The swelling index was measured as follows: 1.3 g of a sample was precisely weighed and dissolved in 25 ml of toluene at a temperature of 25 ° C. for 24 hours, and then the mass (a) of the solution was measured in advance. Transfer to a centrifuge tube having a volume of 50 ml, and set the temperature in the centrifuge to 10 ° C. using a rotor with a maximum centrifugal radius of 10.7 cm, and centrifuge at 15,000 rpm for 60 minutes. After removing the non-precipitate by slowly inverting the centrifuge tube and holding it for 10 seconds, the mass (b) of the centrifuge tube before drying is measured. The centrifuge tube is dried in a vacuum dryer at a temperature of 60 ° C. for 24 hours, the mass (c) of the centrifuge tube after drying is measured, and the swelling index is calculated by the following formula:
Swelling index = (ba) / (ca)
(2) The total of the styrenic monomer, (meth) acrylic acid ester monomer and other monomers remaining in the rubber-modified copolymer resin composition is as follows according to the GC (gas chromatography) method. Measured under conditions:
Device name: GC12A FID detector column manufactured by Shimadzu Corporation: Glass column φ3mm × 3m
Filler: Polyethylene glycol carrier: Nitrogen temperature: Column 115 ° C, inlet 220 ° C
Injection sample: 0.5 g of sample was dissolved in 10 mL of N, N-dimethylformamide containing cyclopentane as an internal standard.
Injection volume: 1 μL
(3) The volume average particle diameter (dv) of the rubber particles was measured as follows: The resin composition or the polymerization solution was dissolved in dimethylformamide and dispersed in an ultrasonic dissolution tank for about 30 minutes. The particle diameter (volume sphere equivalent diameter) measured by polarization scattering intensity difference measurement (PIDS theory) was dropped into a laser diffraction / scattering particle size distribution analyzer (LS-230) manufactured by Beckman Coulter, Inc. = (6v / π) ^1/3 ) was determined as the average particle size obtained by the following formula:

(Ni is the ratio of the number of rubber particles having a particle diameter Di)
(4) The weight average molecular weight (Mw) of the rubber-modified copolymer resin composition was measured under GPC measurement conditions as described below:
Device name: SYSTEM-21 Shodex (manufactured by Showa Denko)
Column: 3 PL gel MIXED-B in series Temperature: 40 ° C
Detection: Differential refractive index Solvent: Tetrahydrofuran Concentration: 2% by mass
Calibration curve: produced using standard polystyrene (PS) (manufactured by PL), and the weight average molecular weight was expressed in terms of PS.
(5) Transparency Using an injection molding machine (IS-50EPN) manufactured by Toshiba Machine Co., Ltd., a plate having a thickness of 2 mm was molded at a mold temperature of 60 ° C. and a cylinder temperature of 230 ° C. Using this molded product, the total light transmittance and haze were measured according to JIS K7105 as a measure of transparency (unit:%). In addition, the Nippon Denshoku Industries Co., Ltd. HAZE meter (NDH-1001DP type) was used for the measuring machine. A total light transmittance of 85% or more and a haze of 4% or less were accepted.
(6) Hue Using a Toshiba Machine Co., Ltd. injection molding machine (IS-50EPN), a plate having a thickness of 2 mm was molded at a mold temperature of 60 ° C and a cylinder temperature of 230 ° C. Using this molded product, the b value was measured using a color difference meter (Σ80) manufactured by Nippon Denshoku Industries Co., Ltd. as a measure of color difference in accordance with JIS K7105 (unit: −). This b value represents the hue, blueness and yellowness of the molded product, and the b value in the Hunter diagram is adopted in accordance with JIS K7105.
(7) Refractive index Refractive index of rubber-like polymer: A test piece having a thickness of 0.5 mm was prepared using a press molding machine, and a digital refractometer RX-2000 (manufactured by Atago Co., Ltd.) was used. Measurement was performed at a temperature of 25 ° C. Note that a saturated aqueous solution of potassium potassium iodide was used as the contact liquid.
Refractive index of continuous phase: Weigh accurately 0.35 g of sample (a), dissolve it in 35 ml of methyl ethyl ketone (MEK) at a temperature of 25 ° C. for 24 hours, and then measure the mass (b) of the solution in advance. The sample was transferred to a centrifuge tube with a capacity of 50 ml and centrifuged at a temperature of 10 ° C. or less and 24000 rpm for 40 minutes using a rotor with a maximum centrifugal radius of 10.7 cm. The supernatant was concentrated and the refractive index was measured (measuring instrument: Elmo). Company type: No16101 Abbe refractometer).
(8) Practical strength Evaluation was made using a 2 mm thick plate molded in (5). In accordance with JIS K7211, 50% fracture energy was measured (unit: kg · cm).
(9) Melt mass flow rate (MFR)
The melt mass flow rate (MFR) of the rubber-modified copolymer resin composition was measured at a temperature of 230 ° C. and a load of 2.16 kg according to JIS K7210.

Reference example 1
A rubber-like polymer A was produced by substantially using the conditions of the method for producing a styrene-butadiene random copolymer rubber described in, for example, US Pat. No. 3,094,512. Specifically, the stainless steel polymerization tank with a jacket, coil, and stirrer with an internal volume of 1000 L was washed with cyclohexane dehydrated to a moisture content of 10 ppm or less and purged with nitrogen, and then the moisture content was maintained under a nitrogen gas atmosphere. 540 kg of cyclohexane containing 152 ppm of tetrahydrofuran dehydrated to 10 ppm or less was charged into the polymerization tank and heated to an internal temperature of 80 ° C., and then 0.8 kg of a cyclohexane solution of 10 wt% n-butyllithium was added. Next, 6.25 kg / hr of styrene dehydrated to a water content of 10 ppm or less and 33.75 kg / hr of butadiene dehydrated by passing through a molecular sieve are simultaneously supplied for 4 hours under a constant condition of an internal temperature of 80 ° C. And polymerized. Thereafter, 65 kg of styrene dehydrated to a water content of 10 ppm or less was added at 80 ° C., and polymerization was performed for 10 minutes within a range where the maximum temperature did not exceed 120 ° C., and all of the charged styrene was polymerized. Thereafter, the polymerization solution was transferred to the next reaction vessel, 0.08 parts by mass of water was added to 100 parts by mass of the polymer to stop the polymerization, and then carbon dioxide gas was added while moving to the next reaction vessel. It was summed up.
Next, 2,4-bis [(octylthio) methyl] -O-cresol (IRGNOX1520L manufactured by Ciba Specialty Chemicals Co., Ltd.) and octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate (IRGNOX 1076 manufactured by Ciba Specialty Chemicals Co., Ltd.) is added to 0.08 parts by mass and 0.24 parts by mass, respectively, with respect to 100 parts by mass of the polymer, and then the solvent is removed by steam stripping. The styrene-butadiene rubbery polymer A was obtained by drying with a hot roll. This rubber-like polymer A had a 5% by mass styrene solution viscosity at 25 ° C. of 25 mPa · s, and the proportion of 1,2-vinyl bonds among the unsaturated bonds based on butadiene was 12 mol%. In addition, by analysis, 0.08 parts by mass of 2,4-bis [(octylthio) methyl] -O-cresol, octadecyl-3- (3,5-di-t-) with respect to 100 parts by mass of the rubber-like polymer. It was confirmed that 0.24 parts by mass of butyl-4-hydroxyphenyl) propionate was contained.

Reference example 2
2,4-bis [(octylthio) methyl] -O-cresol (IRGNOX1520L manufactured by Ciba Specialty Chemicals Co., Ltd.) and octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (Ciba A styrene-butadiene system was carried out in the same manner as in Reference Example 1 except that 0.10 parts by mass and 0.24 parts by mass of Special Chemicals IRGNOX 1076) were added to 100 parts by mass of the polymer, respectively. A rubbery polymer B was obtained. This rubber-like polymer B had a 5% by mass styrene solution viscosity at 25 ° C. of 25 mPa · s, and the proportion of 1,2-vinyl bonds among the unsaturated bonds based on butadiene was 12 mol%. In addition, by analysis, 0.10 parts by mass of 2,4-bis [(octylthio) methyl] -O-cresol, octadecyl-3- (3,5-di-t) with respect to 100 parts by mass of the rubber-like polymer. It was confirmed that 0.24 parts by mass of (butyl-4-hydroxyphenyl) propionate was contained.

Reference example 3
Except for adding 0.31 part by mass of 2,4-bis [(octylthio) methyl] -O-cresol (IRGNOX1520L manufactured by Ciba Specialty Chemicals Co., Ltd.) to 100 parts by mass of the polymer, the same as in Reference Example 1 To obtain a styrene-butadiene rubbery polymer C. This rubber-like polymer C had a 5 mass% styrene solution viscosity at 25 ° C. of 25 mPa · s, and the proportion of 1,2-vinyl bonds among the unsaturated bonds based on butadiene was 12 mol%. Further, it was confirmed by analysis that 0.31 part by mass of 2,4-bis [(octylthio) methyl] -O-cresol was contained with respect to 100 parts by mass of the rubber-like polymer.

Reference example 4
The same procedure as in Reference Example 1 was conducted except that 2,4-bis [(octylthio) methyl] -O-cresol (IRGNOX1520L manufactured by Ciba Specialty Chemicals Co., Ltd.) was not added to 100 parts by mass of the polymer. Thus, a styrene-butadiene rubber-like polymer D was obtained. This rubber-like polymer D had a 5% by mass styrene solution viscosity at 25 ° C. of 25 mPa · s, and the proportion of 1,2-vinyl bonds among the unsaturated bonds based on butadiene was 12 mol%. Moreover, it was confirmed by analysis that 2,4-bis [(octylthio) methyl] -O-cresol was not contained with respect to 100 parts by mass of the rubber-like polymer.

Example 1
A complete mixing-type stirred tank of about 5 L in volume, a second reactor of about 20 L in volume, a column type plug flow reactor with a volume of about 40 L, and two devolatilization tanks equipped with a preheater are connected in series. Connected to configure the reactor. 7% by mass of the rubber-like polymer A obtained in Reference Example 1 was 44% by mass of styrene, 31% by mass of methyl methacrylate (hereinafter referred to as MMA), 6% by mass of n-butyl acrylate (hereinafter referred to as n-BA), and 12% by mass of ethylbenzene. Dissolved in the mixed solution composed, and further 1,2-bis (t-butylperoxy) -cyclohexane (Perhexa C, manufactured by NOF Corporation, 1 hour half-life temperature 111.1 ° C.) 0.02% by mass, octadecyl- 0.2% by mass of 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (IRGANOX1076 manufactured by Ciba Specialty Chemicals Co., Ltd.) was mixed to obtain a raw material solution. This raw material solution was introduced into a first reactor controlled at a temperature of 110 ° C. at 7 kg / hour. The reaction solution was continuously withdrawn from the first reactor, and 3.0 g of n-dodecyl mercaptan (thiocalcol 20 manufactured by Kao Corporation) was added to the reaction solution per hour, and then introduced into the second reactor controlled at a temperature of 130 ° C. . The second reactor was stirred at 100 rpm. Next, the reaction solution was continuously withdrawn from the second reactor, and after adding 3.0 g of n-dodecyl mercaptan per hour to this reaction solution, the temperature was adjusted to 130 ° C. to 150 ° C. in the direction of flow. Was introduced into a tower-type plug flow reactor. While heating this reaction liquid with a preheater, it was introduced into the first devolatilization tank controlled at a temperature of 175 ° C. and a pressure of 70 kPa, and further introduced into a devolatilization tank controlled at a temperature of 240 ° C. and a pressure of 0.7 kPa. Then, volatile components such as unreacted monomers were removed. The resin liquid was extracted with a gear pump and extruded and cut into a strand shape to obtain a pellet-shaped resin. Table 1 shows the physical property evaluation results.

Example 2
It carried out similarly to Example 1 except having controlled the 2nd devolatilization tank pressure to 1.4 kPa. Table 1 shows the physical property evaluation results.

Example 3
9% by mass of the rubber-like polymer A was dissolved in a mixed solution composed of 43% by mass of styrene, 30% by mass of MMA, 6% by mass of n-BA, and 12% by mass of ethylbenzene, and the stirring number of the second complete mixing type reactor was 150 rpm. The same procedure as in Example 1 was performed except that. Table 1 shows the physical property evaluation results.

Example 4
The same operation as in Example 1 was conducted except that the resin temperature in the second devolatilization tank was controlled to 255 ° C. Table 1 shows the physical property evaluation results.

Example 5
The same procedure as in Example 1 was conducted except that the resin temperature in the second devolatilization tank was controlled at 225 ° C. Table 1 shows the physical property evaluation results.

Example 6
The same procedure as in Example 1 was conducted except that 7% by mass of rubber-like polymer A was dissolved in a mixed solution composed of 45.6% by mass of styrene, 29.4% by mass of MMA, 6% by mass of n-BA, and 12% by mass of ethylbenzene. It was. Table 1 shows the physical property evaluation results.

Example 7
The same procedure as in Example 1 was conducted except that octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate was not added to the raw material solution. Table 1 shows the physical property evaluation results.

Example 8
The same procedure as in Example 1 was performed except that the rubber-like polymer B obtained in Reference Example 2 was used. Table 1 shows the physical property evaluation results.

Example 9
11% by mass of rubber-like polymer A was dissolved in a mixed solution composed of 41.1% by mass of styrene, 29.9% by mass of MMA, 6% by mass of n-BA, and 12% by mass of ethylbenzene. The same procedure as in Example 1 was performed except that the number of stirring was 200 rpm. Table 1 shows the physical property evaluation results.

Example 10
The same procedure as in Example 1 was performed except that the gas was introduced into one devolatilization tank controlled at a temperature of 240 ° C. and a pressure of 0.7 kPa. Table 1 shows the physical property evaluation results.

Comparative Example 1
It carried out like Example 1 except having controlled the 2nd devolatilization tank pressure to 50.0 kPa. Table 2 shows the physical property evaluation results.

Comparative Example 2
The same procedure as in Example 1 was performed except that the resin temperature in the second devolatilization tank was controlled at 215 ° C. Table 2 shows the physical property evaluation results.

Comparative Example 3
The same procedure as in Example 1 was performed except that the rubber-like polymer C obtained in Reference Example 3 was used. Table 1 shows the physical property evaluation results.

Comparative Example 4
The same procedure as in Example 1 was performed except that the resin temperature in the second devolatilization tank was controlled at 270 ° C. Table 2 shows the physical property evaluation results.

Comparative Example 5
The same procedure as in Example 1 was performed except that the number of stirrings in the second complete mixing reactor was 50 rpm. Table 2 shows the physical property evaluation results.

Comparative Example 6
The same procedure as in Example 1 was performed except that the number of stirrings in the second complete mixing reactor was changed to 300 rpm. Table 2 shows the physical property evaluation results.

Comparative Example 7
The same procedure as in Example 1 was conducted except that the amount of n-dodecyl mercaptan added to the reaction solution continuously withdrawn from the second complete mixing reactor was changed to 40.0 g per hour. Table 2 shows the physical property evaluation results.

Comparative Example 8
The same procedure as in Example 1 was performed except that the rubber-like polymer D obtained in Reference Example 4 was used. Table 2 shows the physical property evaluation results.

As can be seen from Comparative Example 1 in Table 2, when the total amount of monomers remaining in the rubber-modified copolymer resin composition is more than 700 ppm, a molded product obtained by molding the rubber-modified copolymer resin composition is Inferior hue. As can be seen from Comparative Example 2, when the resin temperature of the second devolatilization tank is lower than 240 ° C., the molded product obtained by increasing the swelling index of the rubber-modified copolymer resin composition has a haze and practical use. Inferior in strength. As can be seen from Comparative Example 3, when the amount of the anti-aging agent contained in the rubbery polymer exceeds 0.3% by mass with respect to the rubbery polymer, the resulting molded product is inferior in haze and practical strength. . As can be seen from the ratio Comparative Examples 4, when the total of the monomers remaining in the rubber-modified copolymer resin composition is larger than 700 ppm, the molded article obtained is inferior in hue. The resulting molded product of the rubber-modified copolymer resin composition is inferior in hue. As can be seen from Comparative Example 5 , when the volume average particle diameter (dv) of the rubber particles dispersed in the resin is larger than 1.6 μm, the resulting molded product is inferior in haze. As can be seen from Comparative Example 6 , when the volume average particle diameter (dv) of the rubber particles dispersed in the resin is smaller than 0.4 μm, the obtained molded product is inferior in hue and practical strength. As can be seen from Comparative Example 7 , when the volume average particle diameter (dv) of the rubber particles dispersed in the resin is larger than 1.6 μm, the obtained molded product is inferior in haze. As can be seen from Comparative Example 8 , when the rubber-like polymer does not contain an anti-aging agent, the molded product obtained by reducing the swelling index of the rubber-modified copolymer resin composition is inferior in hue.
On the other hand, as can be seen from Examples 1 to 10 in Table 1, the rubber-modified copolymer resin composition of the present invention has good transparency and hue of the product, and is excellent in practical strength.

  The rubber-modified copolymer resin composition of the present invention has good transparency, product hue, and practical strength, and is useful for various applications such as home appliances and packaging materials. In particular, the rubber-modified copolymer resin composition of the present invention is suitable as a beverage / food container, packaging material, molded product, sheet, film, or the like that requires high transparency.

Claims (7)

Under Symbol of the general formula (1):

Wherein R ₁ and R ₃ represent —CH ₂ —S—R ₅ (R ₅ represents an alkyl group having 1 to 18 carbon atoms), R ₂ represents a hydrogen atom or a methyl group, R ₄ Represents an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms)
In the presence of a styrene-butadiene random copolymer rubber containing 0.02 to 0.3% by mass of an antioxidant represented by the formula (1), a styrene monomer and a (meth) acrylic acid ester monomer preparative styrene monomer to the (meth) ratio 1-99 parts by weight of acrylic acid ester monomer: 99-1 parts by weight of (styrene monomer, and (meth) acrylic acid ester monomer butadiene random copolymer rubber 0.1 to 30 parts by weight of the rubber-modified copolymer obtained by copolymerizing at a rate of polymerization - total styrene per 100 parts by weight of the monomer in which) and 100 parts by weight of The volume average particle diameter (dv) of the rubber particles dispersed in the resin is 0.4 to 1.6 μm, and the refractive index of the styrene- butadiene random copolymer rubber at a temperature of 25 ° C. Monomer and (meth) acrylic The difference between the refractive index of the continuous phase made by copolymerizing ester-based monomer is not more than 0.003, a swelling index with toluene at 25 ° C. is 5 to 11, single remaining in the resin A molded product obtained by molding a rubber-modified copolymer resin composition having a total of 700 ppm or less by mass , and an injection-molded plate having a thickness of 2 mm has a total light transmittance of 85% or more and a haze value of 4 % Moldings with% or less . The styrene - butadiene random copolymer rubber, molded product according to claim 1, wherein the copolymer comprising styrene monomer units 32-45 wt%. The molded product according to claim 1 or 2, wherein the styrene monomer is styrene, and the (meth) acrylic acid ester monomer is methyl methacrylate and n-butyl acrylate. The molded article according to any one of claims 1 to 3, wherein the anti-aging agent is 2,4-bis [(octylthio) methyl] -O-cresol. Molded product according to any one of claims 1 to 4 plate thickness 2mm injection molded has less color phase 2.0. The following general formula (1):

Wherein R ₁ and R ₃ represent —CH ₂ —S—R ₅ (R ₅ represents an alkyl group having 1 to 18 carbon atoms), R ₂ represents a hydrogen atom or a methyl group, R ₄ Represents an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms)
Is blended with a styrene-butadiene random copolymer rubber , and in the presence of the styrene- butadiene random copolymer rubber blended with the antioxidant, a styrene monomer and ( after the resin rate is copolymerized so as to 60 to 95% by mass meth) acrylic acid ester monomer solution or bulk, volatiles were introduced into 2 groups or more devolatilizing tank by connecting in series When the amount of the monomer remaining in the resin composition is reduced by removing the devolatilization tank , the devolatilization tank is operated at a temperature of 150 to 200 ° C. and a pressure of 100 kPa or less at the first stage, and at a temperature of 220 to 200 at the second stage. 260 ° C., is operated below a pressure 7 kPa, the manufacturing method of the rubber-modified copolymer resin composition to below 700ppm by total weight of the mass of the monomer remaining in the resin composition. The method according to claim 6, wherein the anti-aging agent is 2,4-bis [(octylthio) methyl] -O-cresol.