JP2005336433A - Rubber-modified copolymer resin composition and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber-modified copolymer resin composition having good moldability and hue and excellent balance between transparency and impact strength. <P>SOLUTION: The rubber-modified copolymer resin composition comprises a rubber-modified copolymer resin obtained by copolymerizing a styrenic monomer and a methacrylic ester monomer in the presence of a rubber-like polymer and an acrylic or a methacrylic ester oligomer having ≤0°C glass transition temperature (Tg). The composition has ≥80°C Vicat softening temperature (VST) measured on the basis of JIS K7206 and ≤10 mass% amount extracted with n-hexane. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rubber-modified copolymer resin composition excellent in production efficiency, good moldability and hue, and excellent in balance between transparency and impact strength, a production method thereof, and a molded article thereof.

  Rubber-modified copolymer resin obtained by copolymerizing styrene monomer and (meth) acrylic acid ester monomer mainly composed of methyl methacrylate in the presence of rubber-like polymer has transparency and impact resistance. Since it is relatively excellent in balance, it is used in various applications including home appliances, sundries, packaging materials, and optical applications (see, for example, Patent Document 1). In recent years, in order to further improve moldability, a technique of copolymerizing a styrene monomer and two (meth) acrylic acid ester monomers (see, for example, Patent Document 2), and further terpene hydrogenation A technique of adding a processability improving agent such as a resin (see, for example, Patent Document 3) is disclosed.

Japanese Examined Patent Publication No. 44-19547 (page 1-10) JP-A-4-277549 (page 1-14) JP-A-5-171001 (page 2-11)

However, when copolymerizing a styrene monomer and two (meth) acrylic acid ester monomers in the presence of a rubbery polymer, the moldability is improved, but the rubber-modified copolymer resins having different moldability In order to obtain a polymer, it is necessary to carry out copolymerization by changing the monomer composition, and the productivity is not efficient. In addition, the cost of refining the recovered solvent in solution polymerization is high, and the economy is inferior. There was a problem.
Moreover, the technology of adding a processability improver such as a terpene-based hydrogenated resin has problems such as insufficient effect of improving moldability, a decrease in hue, and insufficient balance between transparency and impact resistance. there were.

  The present invention does not require copolymerization of two (meth) acrylic acid ester monomers, has excellent production efficiency, good moldability and hue, and excellent balance between transparency and impact strength The present invention relates to a modified copolymer resin composition and a production method.

  As a result of intensive studies to solve such problems, the present inventors have obtained a rubber-modified copolymer obtained by copolymerizing a styrene monomer and a methacrylate ester monomer in the presence of a rubber-like polymer. It consists of a resin and a (meth) acrylate oligomer having a glass transition temperature (Tg) of 0 ° C. or less, a Vicat softening temperature (VST) measured in accordance with JIS K7206 is 80 ° C. or more, and an n-hexane extract is 10 mass. The rubber-modified copolymer resin composition characterized by being no more than% has been found to have good moldability and hue, and excellent balance between transparency and impact strength, and has led to the present invention.

  In addition, a method for producing a rubber-modified copolymer resin composition characterized by adding a (meth) acrylic acid ester oligomer having a glass transition temperature (Tg) of 0 ° C. or less during copolymerization is excellent in production efficiency and molding. The present invention has been found out that the property and hue are excellent and the balance between transparency and impact strength is excellent.

  Furthermore, the method for producing a rubber-modified copolymer resin composition characterized in that the copolymerization is solution polymerization has excellent production efficiency, good moldability and hue, and excellent balance between transparency and impact strength. And found the present invention.

That is, the present invention relates to a rubber-modified copolymer resin obtained by copolymerizing a styrene monomer and a methacrylic acid ester monomer in the presence of a rubber-like polymer and a glass transition temperature (Tg) of 0 ° C. or less ( A rubber-modified copolymer resin comprising a (meth) acrylate ester-based oligomer, having a Vicat softening temperature (VST) measured in accordance with JIS K7206 of 80 ° C. or more and an n-hexane extract of 10% by mass or less. It is a composition.
Further, the rubber-modified copolymer resin composition is characterized in that the weight average molecular weight of the (meth) acrylate oligomer is 200 to 8000, and the rubber-modified copolymer resin and the (meth) acrylate ester The rubber-modified copolymer resin composition is characterized in that the ratio of the oligomer is 90 to 99.5 parts by mass: 10 to 0.5 parts by mass, and the melt mass flow rate is 2 g / 10 min or more. The rubber-modified copolymer resin composition described above. A method for producing the rubber-modified copolymer resin composition described above, wherein a (meth) acrylic acid ester oligomer having a glass transition temperature (Tg) of 0 ° C. or less is added during copolymerization, and the copolymerization is solution polymerization. It is also a manufacturing method of said rubber-modified copolymer resin composition characterized by being, It is related with the molded object formed by shape | molding the rubber-modified copolymer resin composition obtained by those manufacturing methods.

  The rubber-modified copolymer resin composition and manufacturing method have excellent production efficiency, good moldability and hue, and excellent balance between transparency and impact strength, so it can be used in various applications including home appliances, packaging materials, and optical applications. Can be widely used.

The present invention is described in detail below.
Examples of the styrene monomer include styrene, α-methyl styrene, p-methyl styrene, pt-butyl styrene and the like. Preferably, styrene is 90% by mass with respect to 100% by mass of the styrene monomer. % Or more.

  Examples of the (meth) acrylic acid ester monomer include methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, Preferably, 90% by mass or more of methyl methacrylate is used with respect to 100% by mass of the (meth) acrylic acid ester monomer.

  The ratio of the styrene monomer and the (meth) acrylate monomer is preferably a styrene monomer: (meth) acrylate monomer = 5 to 95 parts by mass: 95 to 5 parts by mass. More preferably, it is styrene monomer: (meth) acrylic acid ester monomer = 10 to 90 parts by mass: 90 to 10 parts by mass. However, the total of the styrene monomer and the (meth) acrylic acid ester monomer is 100 parts by mass.

  Copolymerizable monomers other than styrene monomers and (meth) acrylic acid ester monomers, such as acrylonitrile, maleic anhydride, (meth) acrylic acid, N-phenylmaleimide, etc. And it can be contained if it is less than 50 mass parts with respect to a total of 100 mass parts of (meth) acrylic acid ester monomer.

Examples of the rubber-like 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. Is a styrene-butadiene block rubber having a styrene content of 15 to 45% by mass, more preferably 10 to 50% by mass. Moreover, the 5 mass% styrene solution viscosity in 25 degreeC of temperature becomes like this. Preferably it is 15-200 mPa * s, More preferably, it is 20-60 mPa * s. The proportion of 1,2-vinyl bonds in the unsaturated bonds based on butadiene is preferably 8 to 25 mol%, more preferably 10 to 16 mol%.
A polymer other than the rubber-like polymer can be contained as long as it is less than 50 parts by mass with respect to 100 parts by mass of the rubber-like polymer.

  The ratio of the rubber-like polymer is preferably 0.1 to 30 parts by mass, more preferably 3 to 15 parts by mass with respect to 100 parts by mass in total of the styrene monomer and the (meth) acrylate monomer. It is.

  The rubber-modified copolymer resin is obtained by copolymerizing a styrene monomer and a (meth) acrylate monomer in the presence of a rubbery polymer. The rubbery polymer is dissolved in a styrene monomer and a (meth) acrylate monomer and then used for copolymerization.

Copolymerization can be carried out by a known method, but is preferably solution polymerization with addition of a known solvent such as ethylbenzene or toluene. The solvent is preferably used in an amount of 25 parts by mass or less, more preferably 2 to 20 parts by mass with respect to a total of 100 parts by mass of the styrene monomer and the (meth) acrylic acid ester monomer. Use of a solvent may lower the viscosity during copolymerization and improve polymerization controllability. Furthermore, in the solution polymerization, the production method of the present invention can reduce the purification cost of the recovered solvent, and is economical.
The copolymerization mode is preferably a continuous polymerization mode. Although there is no restriction | limiting in particular as a reaction apparatus, It is preferable to use combining a complete mixing type reactor, a column type plug flow type reactor, a devolatilization tank, etc.
The copolymerization temperature is preferably 80 to 170 ° C, more preferably 100 to 160 ° C.

At the time of copolymerization, t-butylperoxybenzoate, t-butylperoxy-2-ethylhexanoate, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1- Bis (t-butylperoxy) -cyclohexane, 2,2-bis (4,4-di-butylperoxycyclohexyl) propane, t-butylperoxyisopropyl monocarbonate, di-t-butyl peroxide, dicumylper Known polymerization initiators such as oxide, ethyl-3,3-di- (t-butylperoxy) butyrate, 4-methyl-2,4-diphenylpentene-1, t-dodecyl mercaptan, n-dodecyl mercaptan, etc. It is preferable to add a known molecular weight regulator.
The addition amount of the polymerization initiator and the molecular weight modifier is preferably 0.005 to 5 parts by mass, more preferably 0 with respect to 100 parts by mass in total of the styrene monomer and the (meth) acrylate monomer. 0.01 to 1 part by mass.

  In addition, a known crosslinking agent such as divinylbenzene and a known antioxidant such as octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate may be added during copolymerization. .

なお、体積平均粒子径（ｄｖ）の制御は重合時の撹拌数、重合開始剤や分子量調整剤の添加量、異なる粒子径を有するゴム変性共重合樹脂の混合等で実施できる。 Rubber particles are dispersed in the rubber-modified copolymer resin. The rubber particles are formed as the polymerization proceeds when the styrene monomer and the methacrylic acid ester monomer are copolymerized in the presence of the rubber-like polymer.
The volume average particle diameter (dv) of the rubber particles is not particularly limited, but is preferably 0.4 to 1.6 μm, more preferably 0.5 to 1.2 μm. The volume average particle diameter (dv) of the present invention is determined by measuring the particle diameter Di (equivalent circle diameter) of about 3000 rubber particles in the photograph from an ultra-thin section transmission electron micrograph of the resin. It is set as the average particle diameter obtained by Formula 1.

The volume average particle size (dv) can be controlled by the number of stirring during polymerization, the addition amount of a polymerization initiator or a molecular weight regulator, mixing of rubber-modified copolymer resins having different particle sizes, and the like.

The rubber-modified copolymer resin composition comprises a rubber-modified copolymer resin and a (meth) acrylic acid ester oligomer having a glass transition temperature (Tg) of 0 ° C. or lower, preferably −10 ° C. or lower, more preferably −20 ° C. or lower. Become.
A (meth) acrylic acid ester oligomer having a glass transition temperature (Tg) of 0 ° C. or lower has, as monomer units, ethyl acrylate (homopolymer Tg = −24 ° C.), n-butyl acrylate (homopolymer Tg = Oligomers mainly composed of hexyl acrylate (homopolymer Tg = −57 ° C.), octyl acrylate (homopolymer Tg = −65 ° C.), hexyl methacrylate (homopolymer Tg = −5 ° C.), etc. I can give you. The monomer unit may be an oligomer containing styrene, acrylonitrile, maleic anhydride, (meth) acrylic acid, N-phenylmaleimide or the like, but is preferably an n-butyl acrylate oligomer. . When a (meth) acrylic acid ester oligomer having a glass transition temperature (Tg) of 0 ° C. or lower is not used, the balance between moldability, transparency and impact strength is poor. The (meth) acrylic acid ester oligomer may be obtained by a known method or commercially available (for example, ARUFON manufactured by Toa Gosei Co., Ltd.). The glass transition temperature (Tg) of the (meth) acrylic acid ester oligomer can be adjusted by the composition and molecular weight.
The weight average molecular weight of the (meth) acrylic acid ester oligomer having a glass transition temperature (Tg) of 0 ° C. or lower is preferably 200 to 8000, more preferably 300 to 2000. When the weight average molecular weight (Mw) is outside this range, the balance between moldability, transparency and impact strength may be poor. The weight average molecular weight (Mw) can be adjusted by an initiator, a chain transfer agent, a polymerization temperature condition, etc. used at the time of (meth) acrylate oligomer polymerization.
In addition, the (meth) acrylic acid ester oligomer weight average molecular weight (Mw) of the present invention is a polystyrene equivalent weight average molecular weight (Mw) measured by GPC, and was measured under the measurement conditions described below.
Device name: GPC-8020 (manufactured by Tosoh Corporation)
Column: 4 KF404-HQ (manufactured by Shodex) Temperature: 40 ° C
Detection: Differential refractive index Solvent: Tetrahydrofuran Concentration: 0.3% by mass
Calibration curve: produced using standard polystyrene (PS) (manufactured by PL), and the weight average molecular weight was expressed in terms of PS.

  The ratio of the rubber-modified copolymer resin and the (meth) acrylic acid ester oligomer having a glass transition temperature (Tg) of 0 ° C. or lower is preferably rubber-modified copolymer resin: glass transition temperature (Tg) of 0 ° C. or lower ( (Meth) acrylate ester oligomer = 90-99.5 parts by mass: 10-0.5 parts by mass, more preferably rubber-modified copolymer resin: (meth) acrylate having a glass transition temperature (Tg) of 0 ° C. or less System oligomer = 95 to 99 parts by mass: 5 to 1 part by mass. However, the total of the rubber-modified copolymer resin and the (meth) acrylic acid ester oligomer having a glass transition temperature (Tg) of 0 ° C. or less is 100 parts by mass. If it is out of this range, the balance between moldability, transparency and impact strength, and the hue may be poor.

  When mixing a rubber-modified copolymer resin and a (meth) acrylate oligomer having a glass transition temperature (Tg) of 0 ° C. or less, a (meth) acrylate ester oligomer having a glass transition temperature (Tg) of 0 ° C. or less is used. It is preferable to add at the time of copolymerization. Further, it is more preferable to add a (meth) acrylic acid ester oligomer having a glass transition temperature (Tg) of 0 ° C. or less after the rubber particles are formed during copolymerization. By adding at the time of copolymerization, the balance between moldability, transparency and impact strength may be further improved.

  The rubber-modified copolymer resin composition has a Vicat softening temperature (VST) measured based on JIS K7206 of 80 ° C. or higher, preferably 81 ° C. or higher, more preferably 82 to 98 ° C. When the Vicat softening temperature (VST) is low, the hue is lowered, the balance between transparency and impact resistance is lowered, and use is limited because of low heat resistance. The Vicat softening temperature (VST) can be adjusted by adjusting the type and amount of (meth) acrylic acid ester (C), the type and amount of (meth) acrylic acid ester oligomer, the amount of initiator used during polymerization, and the like. it can. The Vicat softening temperature (VST) is 50 methods (load 50 N, temperature rising rate 50 ° C./hour), and the test piece is 10 mm × 10 mm and 4 mm thick.

The rubber-modified copolymer resin composition has an n-hexane extract content of 10% by mass or less, preferably 1 to 8% by mass or less, and more preferably 2 to 6% by mass. When the n-hexane extract exceeds 10% by mass, heat resistance, transparency and hue are lowered. The n-hexane extract can be adjusted by the amount of (meth) acrylic acid ester oligomer added.
The n-hexane extract of the present invention is obtained by evaporating an extract obtained by refluxing a freeze-pulverized sample (assumed to be Ag) for 6 hours or more using an extractor such as Soxhlet. An extract (referred to as Bg) is obtained by drying and is calculated by the following formula [Equation 2].

  The rubber-modified copolymer resin composition preferably has a melt mass flow rate (MFR) measured based on JIS K7210 of 2 g / 10 minutes or more, more preferably 3 to 10 g / 10 minutes. When the melt mass flow rate (MFR) is outside this range, a molded product having a complicated shape may not be obtained in injection molding, or the balance between transparency and impact resistance may be poor. The melt mass flow rate (MFR) can be adjusted with the type and amount of the (meth) acrylic acid ester oligomer, the initiator used during the polymerization, the chain transfer agent, and the like. The melt mass flow rate (MFR) is measured using resin pellets at a temperature of 200 ° C. and a load of 49 N.

The gel content of the rubber-modified copolymer resin composition is not particularly limited, but is preferably 10 to 30% by mass, and more preferably 12 to 25% by mass. If the gel content is outside this range, the balance between transparency and impact resistance may be poor. Adjustment of a gel part can be adjusted with the addition amount of rubber-like polymer (A), the stirring conditions at the time of superposition | polymerization, the kind and addition amount of a polymerization initiator, a molecular weight regulator, etc.
The gel content in the present invention is measured as follows.
A sample of 0.35 g was precisely weighed (a) and dissolved in 35 ml of methyl ethyl ketone (MEK) at a temperature of 25 ° C. for 24 hours, and then the lysate was transferred to a 50 ml centrifuge tube whose mass (b) was measured in advance. Using a rotor with a maximum centrifugal radius of 10.7 cm, centrifuge at 24,000 rpm for 40 minutes at a temperature of 10 ° C. or less, remove the non-precipitated matter by decantation, and dry it in a vacuum dryer at a temperature of 70 ° C. for 24 hours. The mass (c) of the centrifuge tube is measured, and the gel content is calculated by the following formula [Equation 3].

The swelling index of the rubber-modified copolymer resin composition is not particularly limited, but is preferably 7 to 17, more preferably 9 to 14. When the swelling index is outside this range, the balance between transparency and impact resistance may be poor. The swelling index of the rubber-modified copolymer resin can be adjusted by adding an antioxidant, heating conditions in the devolatilization tank, or the like.
The swelling index is measured as follows. After about 0.35 g of sample was dissolved in 35 ml of toluene at a temperature of 25 ° C. for 24 hours, the lysate was transferred to a 50 ml centrifuge tube whose mass (d) was measured in advance, and a rotor with a maximum centrifugal radius of 10.7 cm was placed. Use, centrifuge at 15000 rpm for 60 minutes at a temperature of 10 ° C. or less, remove the non-precipitate by decantation, and then measure the mass (e) of the centrifuge tube before drying. It is dried in a vacuum dryer at a temperature of 70 ° C. for 24 hours, the mass (f) of the centrifuge tube after drying is measured, and the swelling index is calculated by the following equation [Equation 4].

  The rubber-modified copolymer resin composition may be added with additives such as antioxidants, weathering agents, lubricants, colorants, antistatic agents, mineral oil, flame retardants, MS resins, emulsion graft copolymers, etc. as necessary. And can be added at any stage during manufacture. The method of adding is not particularly limited, and examples thereof include a method of adding at the time of polymerization and a method of melt kneading with an extruder.

  The rubber-modified copolymer resin composition is processed into various molded articles by a known method such as injection molding, extrusion molding, compression molding, vacuum molding, etc., and is put to practical use.

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

Reference example 1
A 500 ml pressurized stirred tank reactor equipped with a hot oil heating device was filled with ethyl 3-ethoxypropionate. The temperature in the reactor was set to 250 ° C. The reactor pressure was set above the expected vapor pressure using a pressure regulator. Next, while maintaining the reactor pressure constant, 100 parts by mass of n-butyl acrylate, 0.1 part by mass of di-t-butyl peroxide and 10 parts by mass of 2,4-diphenyl-4-methyl-1-pentene were weighed. The raw material liquid was prepared and stored in the raw material tank. The raw material liquid was continuously supplied from the raw material tank to the reactor while keeping the pressure in the reactor constant. At this time, the feed rate was set so that the average residence time of the raw material liquid in the reactor was 12 minutes. A reaction liquid corresponding to the feed amount of the raw material liquid was continuously extracted from the outlet of the reactor. During the continuous supply of the raw material liquid, the temperature in the reactor was maintained at 250 ° C. The obtained reaction solution was introduced into a thin film evaporator, and unreacted monomers were removed under reduced pressure at 235 ° C. and 40 kPa to obtain a (meth) acrylate oligomer. The obtained (meth) acrylic acid ester oligomer had a glass transition temperature (Tg) of −71 ° C. and a weight average molecular weight (Mw) of 2400.
Reference example 2
The same operation as in Reference Example 1 was performed except that the temperature in the reactor was set to 270 ° C. The obtained (meth) acrylic acid ester oligomer had a glass transition temperature (Tg) of −78 ° C. and a weight average molecular weight (Mw) of 1500.
Reference example 3
The same operation as in Reference Example 1 was performed except that the temperature in the reactor was set to 270 ° C. The obtained (meth) acrylic acid ester oligomer had a glass transition temperature (Tg) of −58 ° C. and a weight average molecular weight (Mw) of 10,000.

Reference example 4
The same procedure as in Reference Example 1 was conducted except that 10 parts by mass of n-butyl acrylate and 90 parts by mass of styrene were used. The obtained (meth) acrylic acid ester oligomer had a glass transition temperature (Tg) of 40 ° C. and a weight average molecular weight (Mw) of 3,500.

Reference Example 5
The same procedure as in Reference Example 1 was conducted except that 55 parts by mass of n-butyl acrylate and 45 parts by mass of styrene were used. The obtained (meth) acrylic acid ester oligomer had a glass transition temperature (Tg) of −15 ° C. and a weight average molecular weight (Mw) of 2900.

Example 1
A first fully mixed reactor of about 5 L with a stirrer, a second fully mixed reactor of about 15 L with a stirrer, a column type plug flow reactor with a volume of about 40 L, and a preheater are attached. The devolatilization tanks were connected in series. Asaprene 670A manufactured by Asahi Kasei Co., Ltd. as a rubbery polymer (styrene-butadiene rubber, styrene content 40% by mass, 5% by mass styrene solution viscosity at 25 ° C. 33 mPa · s, 1,2-vinyl bond ratio 13.9 mol% 9.3 parts by mass in a mixed solution composed of 52 parts by mass of styrene, 48 parts by mass of methyl methacrylate (hereinafter referred to as MMA) and 15 parts by mass of ethylbenzene, and further 1,1-bis (t-butylperoxy) -0.03 part by mass of cyclohexane and 0.05 part by mass of octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate were mixed to obtain a raw material solution. This raw material solution was introduced into a first complete mixing reactor controlled at a temperature of 115 ° C. at 7 kg / hour. The reaction solution was continuously withdrawn from the first complete mixing reactor, and 3.0 g of n-dodecyl mercaptan was added to the reaction solution per hour, and then introduced into the second complete mixing reactor controlled at a temperature of 130 ° C. The number of stirrings in the second complete mixing type reactor was 150 rpm to form rubber particles. Next, the reaction solution was continuously withdrawn from the second complete mixing reactor, and 4.0 g of n-dodecyl mercaptan per hour and 160 g of the (meth) acrylate oligomer obtained in Reference Example 1 were added to the reaction solution. Then, it was introduced into a column type plug flow reactor adjusted so as to have a temperature gradient of 130 ° C. to 150 ° C. in the direction of flow. While the reaction liquid extracted from the tower-type plug flow reactor is heated by a preheater, it is introduced into a devolatilization tank controlled at a temperature of 230 ° C and a pressure of 1.3 kPa to remove volatile components such as ethylbenzene and monomers. did. 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
The same operation as in Example 1 was conducted except that the amount of the (meth) acrylic acid ester oligomer obtained in Reference Example 1 was changed to 320 g / hour. Table 1 shows the physical property evaluation results.

Example 3
The same procedure as in Example 1 was performed except that the (meth) acrylic acid ester oligomer obtained in Reference Example 2 was used. Table 1 shows the physical property evaluation results.

Comparative Example 1
The same procedure as in Example 1 was performed except that the (meth) acrylate ester oligomer was not added. Table 1 shows the physical property evaluation results.

Comparative Example 2
The same procedure as in Example 1 was conducted except that the (meth) acrylic acid ester oligomer obtained in Reference Example 1 was changed to 1600 g per hour. Table 1 shows the physical property evaluation results.

Comparative Example 3
The same operation as in Example 1 was performed except that the (meth) acrylic acid ester oligomer obtained in Reference Example 4 was used. Table 1 shows the physical property evaluation results.

Example 4
100 parts by mass of the resin obtained in Comparative Example 1 and 3 parts by mass of the (meth) acrylic acid ester oligomer obtained in Reference Example 1 were extruded at 230 ° C. using a twin-screw extruder. Table 1 shows the physical property evaluation results.

Example 5
The same procedure as in Example 1 was performed except that the (meth) acrylic acid ester oligomer obtained in Reference Example 5 was used. Table 1 shows the physical property evaluation results.

Example 6
The same procedure as in Example 1 was performed except that the (meth) acrylic acid ester oligomer 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 mixed solution was composed of 52 parts by mass of styrene, 38 parts by mass of MMA, 10 parts by mass of n-butyl acrylate, and 15 parts by mass of ethylbenzene. Table 1 shows the physical property evaluation results.

Comparative Example 5
The same procedure as in Comparative Example 2 was performed except that the (meth) acrylic acid ester oligomer obtained in Reference Example 4 was used. Table 1 shows the physical property evaluation results.

  Examples relating to the rubber-modified copolymer resin composition of the present invention are all good in moldability and hue, excellent in balance between transparency and impact resistance, and in comparative examples that do not meet the conditions of the present invention, molding The property and hue were good, and any of the physical properties of the balance between transparency and impact resistance was inferior.

The evaluation was based on the following method.
(1) Vicat softening temperature (VST)
The Vicat softening temperature (VST) is measured based on JIS K7206 using 50 samples (load 50 N, temperature rising rate 50 ° C./hour) with a test piece of 10 mm × 10 mm and a thickness of 4 mm. In addition, the measuring machine used the Toyo Seiki Seisakusho HDT & VSPT test apparatus.
(2) n-hexane extract The n-hexane extract was measured by the method described above.

(3) Glass transition temperature (Tg)
Measurement was performed using EXSTAR6000 DSC (manufactured by Seiko Instruments Inc.) at a temperature increase rate of 10 ° C./min.
(4) Weight average molecular weight (Mw)
The weight average molecular weight (Mw) of the (meth) acrylic acid ester oligomer was measured by the method described above.

(5) Melt mass flow rate (MFR)
Melt mass flow rate (MFR) was measured using resin pellets at a temperature of 200 ° C. and a load of 49 N based on JIS K7210. The measuring machine used was a melt indexer (F-F01) manufactured by Toyo Seiki Seisakusho.

(6) Transparency 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 40 ° C and a cylinder temperature of 230 ° C. Using this molded product, the haze value was measured using a HAZE meter (NDH-1001DP type) manufactured by Nippon Denshoku Industries Co., Ltd. (unit:%) in accordance with JIS K7105 as a measure of transparency. A haze value of 3% or less was accepted.
(7) Charpy impact strength As a measure of impact resistance, based on JIS K7111, a type 1 test piece having a notch type A was used, and the impact direction was measured using edgewise to measure the Charpy impact strength (unit: kJ / M2). The measuring machine used was a digital impact tester manufactured by Toyo Seiki Seisakusho. Charpy impact strength of 7 kJ / m2 or more was accepted.
(8) 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 40 ° 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: −). The b value was 3 or less.

Claims (7)

A rubber-modified copolymer resin obtained by copolymerizing a styrene monomer and a methacrylic acid ester monomer in the presence of a rubber-like polymer and a (meth) acrylic acid ester having a glass transition temperature (Tg) of 0 ° C. or less. A rubber-modified copolymer resin composition comprising a system oligomer and having a Vicat softening temperature (VST) measured in accordance with JIS K7206 of 80 ° C. or more and an n-hexane extract of 10% by mass or less. The rubber-modified copolymer resin composition according to claim 1, wherein the weight average molecular weight of the (meth) acrylic acid ester oligomer is 200 to 8000. The ratio of the rubber-modified copolymer resin and the (meth) acrylic acid ester oligomer is 90 to 99.5 parts by mass: 10 to 0.5 parts by mass. Copolymer resin composition. The rubber-modified copolymer resin composition according to any one of claims 1 to 3, wherein the melt mass flow rate is 2 g / 10 min or more. The rubber-modified copolymer according to any one of claims 1 to 4, wherein a (meth) acrylate oligomer having a glass transition temperature (Tg) of 0 ° C or lower is added during copolymerization. A method for producing a resin composition. The method for producing a rubber-modified copolymer resin composition according to any one of claims 1 to 4, wherein the copolymerization is solution polymerization. A molded article obtained by molding the rubber-modified copolymer resin composition obtained by the production method of claim 5 or 6.