JP2002097335A - Rubber-modified aromatic vinyl-based copolymer resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber-modified aromatic vinyl-based copolymer resin composition having transparency and excellent in practical physical properties, particularly Charpy impact strength and drop impact strength. SOLUTION: This resin composition comprises 99-80 wt.% rubber-modified aromatic vinyl-based copolymer resin containing a styrene-butadiene block copolymer having a specific glass transition temperature as disperse particles and 1-20 wt.% at least one kind of resin selected from hydrogenated coumarone, MBS resin and a styrene-butadiene-based block copolymer resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a food packaging container, a blister pack, a general container case, a sheet, which is transparent and has improved practical properties such as impact strength, fluidity, low-temperature moldability and the like.
The present invention relates to a high impact aromatic vinyl resin copolymer composition that can be widely used for films and the like. Specifically, an aromatic vinyl- (meth) acrylic acid alkyl ester-based copolymer having one or more aromatic vinyl-based structural units having a specific ratio and one or more alkyl (meth) acrylate-based structural units is used. As a continuous phase, rubber-like polymer particles having a specific glass transition point are used as a dispersed phase, and as additives, hydrogenated coumarone resin, MBS resin, styrene-
The present invention relates to a rubber-modified aromatic vinyl copolymer resin composition containing a resin selected from any of butadiene-based block copolymer resins and having excellent transparency, impact strength, and low-temperature moldability.

[0002]

2. Description of the Related Art In general, various styrene-butadiene block copolymers, such as those having a linear block structure and those having a radially branched block structure, are known.
As its properties, it is remarkably excellent in transparency, and generally changes from a rubbery state to a resinous state as the styrene content increases. However, such a styrene-butadiene block copolymer has a drawback of being inferior in practical physical properties such as rigidity and strength, and conventionally, polystyrene is blended in order to solve such a drawback. However, blending polystyrene with the styrene-butadiene block copolymer improves rigidity but has problems such as impairing transparency, which is an excellent property of the styrene-butadiene block copolymer.

In order to maintain and improve the transparency and to improve the impact resistance developed by rubber reinforcement, there have been proposed many methods of polymerizing a mixed solution comprising styrene, alkyl methacrylate and a butadiene rubber polymer. I have. For example, JP-A-52-124095,
JP-A-62-169812, JP-A-62-151
No. 415 describes a method for polymerizing a mixed solution comprising an aromatic vinyl, an alkyl methacrylate, a methyl methacrylate and a diene rubber polymer.

[0004]

However, in the techniques disclosed therein, the obtained thermoplastic resin is transparent and exhibits high elongation in tensile properties. However, as shown in the Izod impact strength, The effect of rubber reinforcement is still inadequate. That is, although the transparency and elongation are improved, the impact strength including the Izod impact strength is not improved. As an improvement, Japanese Patent Laid-Open Publication No.
No. 0855, No. 7-97500, No. 7-2921
No. 91 proposes a composition in which a resin component such as MBS is added to a resin obtained from styrene, alkyl (meth) acrylates, and a styrene-butadiene rubber polymer. Although the impact strength has been improved, there is still a problem that the balance of fluidity, impact strength, and transparency is poor.

[0005]

SUMMARY OF THE INVENTION In view of such circumstances, the present inventors have found that they have transparency, a good balance of impact strength and fluidity, and have excellent physical properties such as optical properties and low-temperature moldability. As a result of intensive studies on the rubber-modified aromatic vinyl copolymer resin composition, the present invention has been completed. That is, the present invention relates to a rubber-modified aromatic vinyl copolymer resin containing a rubbery polymer as dispersed particles in a continuous matrix resin, wherein (1) the continuous matrix has a refractive index substantially equivalent to that of the rubbery polymer. Having a structural unit of 20 to 80% by mass of one or more aromatic vinyl compounds and one or more alkyl (meth) acrylate compounds 20 to
For 97 to 80% by mass of the copolymer which is 80% by mass,
(2) The content of the rubbery polymer of 3 to 20% by mass,
The glass transition point of the dispersed particles is in the range of −75 to −30 ° C., and the average particle size of the dispersed particles is 0.3 to 2.1 μm.
m, the rubber-modified aromatic vinyl copolymer resin 99 to 8
0% by mass, hydrogenated coumarone resin as an additive,
1 to 20% by mass of a resin selected from the group consisting of MBS resin and styrene-butadiene block copolymer resin
The present invention relates to a transparent rubber-modified aromatic vinyl copolymer resin composition characterized by containing.

Hereinafter, the present invention will be described in detail. The rubber-modified aromatic vinyl copolymer resin constituting the present invention, in the presence of a rubbery polymer, an aromatic vinyl compound and (meth)
It is obtained by copolymerizing an alkyl acrylate compound with one or more compounds which can be copolymerized with an aromatic vinyl compound and an alkyl (meth) acrylate compound if necessary. . Here, as the aromatic vinyl compound, for example, in addition to styrene,
α-alkyl-substituted styrene such as α-methylstyrene, α-methyl-p-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4
-Dimethylstyrene, ethylstyrene, p-tert-
Nuclear alkyl-substituted styrenes such as butylstyrene, o-
Conventional rubbers such as chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-bromostyrene, nuclear halogenated styrene such as 2-methyl-1,4-chlorostyrene, 2,4-dibromostyrene, and vinylnaphthalene One or a mixture of two or more styrene compounds known for a modified styrene resin is used. Typically, styrene alone or a combination of styrene and other aromatic vinyl compounds described above is used. Is performed.

The alkyl (meth) acrylate compounds include methyl methacrylate, ethyl methacrylate, butyl methacrylate, methoxyethyl acrylate,
Lauryl methacrylate, tridecyl methacrylate, palmitin methacrylate, pentadecyl methacrylate, stearyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, lauryl acrylate, tridecyl acrylate, palmitin acrylate, pentadecyl acrylate, acrylic acid Stearyl and the like.

The compound which can be copolymerized with the aromatic vinyl compound and the alkyl (meth) acrylate compound constituting the aromatic vinyl copolymer resin of the present invention includes, for example, acrylonitrile, methacrylonitrile, fumaronitrile, Vinyl cyanide such as maleonitrile and α-chloroacrylonitrile; maleimide such as methacrylic acid, acrylic acid, maleic anhydride, and phenylmaleimide; vinyl acetate and divinylbenzene; and aromatic vinyl compounds and alkyl (meth) acrylates. Used as a mixture with an ester compound.

The rubbery polymer dispersed in the rubber-modified aromatic vinyl copolymer resin component of the present invention in the form of particles includes a block portion (A) composed of a random or tapered copolymer of styrene and butadiene; It is a block copolymer composed of a polymer or a styrene-butadiene copolymer block part (B) composed mostly of styrene. Preferably, (a) the rubber-based polymer has a mass ratio of the block portion (A) composed of a random or tapered copolymer of styrene and butadiene of 15 to 15%.
95% by mass, the mass ratio of the styrene homopolymer or the styrene-butadiene copolymer block portion (B) composed mostly of styrene is 85 to 5% by mass, and (b) styrene is 5 to 35% by mass. Butadiene and styrene random or tapered copolymer block portion (A) comprising 70% by mass and 65% to 95% by mass of butadiene; and styrene comprising 90% to 100% by mass of styrene and 0% to 10% by mass of butadiene. It comprises a homopolymer or a styrene-butadiene copolymer block part (B) composed mostly of styrene, and (c) a glass transition point of a random or tapered copolymer part (A) of butadiene and styrene is -80. To (-35 ° C), and among (d) butadiene-based unsaturated bonds,
(E) a styrene-butadiene-based block copolymer in which the ratio of 1,2-vinyl bonds is 8.0 to 20.0% by mass, and the viscosity of a 5% by mass styrene solution at 25 ° C. is in the range of 20 to 50 centipoise. Combination is preferred.

More preferably, (a) the mass ratio of the block portion (A) composed of a random or tapered copolymer of styrene and butadiene in the rubbery polymer is 60 to 90% by mass, and the styrene homopolymer or large The styrene-butadiene copolymer block portion (B) in which the portion is composed of styrene has a mass ratio of 40 to 10
Mass%, and (b) styrene 10 mass% to 25 mass%
Or a butadiene and styrene random or tapered copolymer block portion (A), comprising 75% to 90% by mass of butadiene, and 95% to 100% by mass of styrene.
And (b) a styrene homopolymer or styrene-butadiene copolymer block portion (B) comprising 0% to 5% by mass of butadiene, and (c) a glass transition of a random or tapered copolymer portion (A) of butadiene and styrene. The point is in the range of −80 to −40 ° C., (d) the ratio of 1,2 vinyl bonds among the unsaturated bonds based on butadiene is 10.0 to 17.0 mass%, and (e) 25 ° C. Is preferably a styrene-butadiene-based block copolymer having a viscosity of a 5% by weight styrene solution in the range of 25 to 40 centipoise. If the proportion of the 1,2-vinyl bond exceeds 20% by mass, the morphology and particle size of the rubber particles become irregular and the impact resistance is poor, while if less than 8% by mass, the rubber form becomes irregular and the impact resistance deteriorates. . 5 at 25 ° C
When the viscosity of the mass% styrene solution is 20 centipoise or less, the impact resistance is poor. If it exceeds 50 centipoise, the particle size of the dispersed rubber particles will be uneven, and the resulting resin will have poor gloss.

In the present invention, the mass ratio of the random or tapered copolymer block portion (A) of butadiene and styrene in the rubbery polymer is 15 to 9%.
The content is 5% by mass, preferably 20 to 90% by mass, and more preferably 60 to 90% by mass. When the mass ratio of the block portion (A) in the copolymer rubber is less than 15% by mass, the rubber particle diameter of the rubber-reinforced transparent resin is reduced, and the impact strength is reduced. Becomes inferior. Also, when the mass ratio of the block portion (A) in the copolymer rubber exceeds 95% by mass, the adhesion at the interface between the dispersed rubber particles in the rubber-reinforced transparent resin and the continuous phase is reduced, so The strength is reduced, and the balance between transparency and impact strength becomes poor.

[0012] In addition, as long as the effects of the present invention are not impaired,
A boundary portion between a block portion (A) composed of a random or tapered copolymer of styrene and butadiene and / or a styrene-butadiene copolymer block portion (B) composed mainly of styrene homopolymer or styrene; A) and / or (B) may have a butadiene block at a part of both ends. In addition,
Here, the random copolymer block portion of styrene and butadiene (A) refers to a copolymer block portion having a structure in which the bonding mode of styrene and butadiene is randomly and uniformly distributed along the polymer chain. The tapered copolymer block portion (A) refers to a copolymer block portion in which the bonding mode of styrene and butadiene has a gradient structure of styrene and butadiene composition along the polymer chain or a structure corresponding thereto.

The rubbery polymer used in the resin composition of the present invention is produced by a usual living anionic polymerization method using an organolithium catalyst in a hydrocarbon solvent. There is no particular limitation on any method such as a method of mixing two or more different block copolymer rubbers. When the rubbery polymer is produced in a hydrocarbon solvent using an organolithium catalyst, examples of the organolithium catalyst include n-propyllithium, isopropylpropyllithium, n-butyllithium, and sec-butyl. Lithium, tert-butyllithium, methyllithium, ethyllithium, n-hexyllithium, cyclohexyllithium, benzyllithium, lithium naphthalene and the like are used, preferably,
n-Butyl lithium, sec-butyl lithium and the like are used. Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as pentane, n-hexane, n-heptane, isooctane, and n-decane; alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclopentane; benzene, xylene, and toluene. Aromatic hydrocarbons are used. Further, a polar substance may be produced in the presence of a polymerization system. Polar substances include triethylamine, tri-n-butylamine, pyridine, N, N, N ', N'-tetramethylethylenediamine, hexamethylphosphoramide, triphenylphosphine, diethyl ether, tetrahydrofuran, dioxane, ethylene glycol methyl ether, diethylene glycol Dimethyl ether, potassium butoxide, sodium butoxide and the like, preferably N, N, N ′, N′-tetramethylethylenediamine,
Tetrahydrofuran or the like is used.

The rubbery polymer used in the present invention is preferably a random or tapered copolymer block part (A) of butadiene and styrene and a styrene homopolymer or a styrene-butadiene copolymer composed mostly of styrene. A styrene-butadiene-based block copolymer composed of a polymer block portion (B) is used. As a method for producing such a styrene-butadiene-based block copolymer by a usual living anion polymerization method, for example, an organic In a hydrocarbon solvent in which a lithium catalyst exists,
A method in which a mixture of butadiene and styrene is supplied at a polymerization rate lower than the polymerization rate of the monomer at a set polymerization temperature to carry out polymerization (for example, a method described in JP-B-38-2394) can be applied. No. That is, polymerization is performed while supplying a monomer mixture having a desired butadiene and styrene composition ratio at a polymerization rate or lower, and then supplying a monomer mixture having a different butadiene and styrene composition ratio at a polymerization rate or lower. Is repeated once or more to obtain the block copolymer of the present invention. Also, a method of adding a polar substance to a polymerization system containing an organolithium catalyst (for example,
Application of the method described in JP-A-6-15386) can also be mentioned as a production method by living anionic polymerization. That is, in a polymerization system containing an organolithium catalyst and a polar substance, a monomer mixture having a desired butadiene / styrene composition ratio is polymerized, and if necessary,
Thereafter, a monomer mixture having a different composition ratio of butadiene and styrene is added and polymerized, and if necessary, this operation is repeated one or more times to obtain the block copolymer of the present invention. A method based on a combination of these methods is also possible.

In the production of the rubber-modified aromatic vinyl copolymer resin composition of the present invention, an organic solvent can be used if necessary. Examples of the organic solvent include benzene, toluene, xylene, ethylbenzene, acetone, isopropylbenzene, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, and the like. It is preferable to use other solvents such as aliphatic hydrocarbons and dialkyl ketones in combination with aromatic hydrocarbons as long as the dissolution of the rubbery polymer is not impaired. The rubbery polymer is composed of an aromatic vinyl compound and an alkyl (meth) acrylate compound or an aromatic vinyl compound and (meth)
It is dissolved in a mixture of an alkyl acrylate compound and a monomer copolymerizable therewith or a solvent.
When an organic solvent is used, the monomer concentration in the polymerization solution and the produced copolymer concentration are reduced, so that the polymerization rate can be reduced to an easily controllable level and the runaway of the polymerization reaction can be prevented. The viscosity of the polymerization liquid decreases, and the uniform mixing of the polymerization liquid and the movement of the polymerization liquid are facilitated, so that the operability as a production process is improved.

However, if the concentration of the organic solvent in the polymerization solution is too high, the polymerization rate is too low, and the productivity is reduced. It is not preferable because the polymer particles easily aggregate and the transparency of the resin decreases. In addition, the recovery energy of the solvent becomes large and the economic efficiency becomes poor. Therefore, the concentration of the organic solvent in the reaction tank is usually in the range of 5 to 50 parts by mass based on 100 parts by mass of the total amount of the polymerization solution. The solvent may be added after the polymerization conversion rate becomes relatively high in viscosity, but it is better to add the solvent before the polymerization in advance, uniformity of quality,
It is preferable from the viewpoint of controlling the polymerization temperature. When polymerizing the monomer, it may be polymerized in the temperature range of 110 to 190 ° C. in the absence of a polymerization initiator, or 50 to 180 ° C. using an organic peroxide that generates radicals as a polymerization initiator. , Preferably in a temperature range of 90 to 150 ° C.,
The polymerization is preferably performed in the presence of a peroxide.

In the present invention, a polymerization initiator can be used. The organic peroxide used is 2,2-bis (t-butylperoxy) butane, 2,2-bis (t-
Peroxyketals such as butylperoxy) octane, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate , Di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t -Butylperoxy) hexane,
Dialkyl peroxides such as 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, acetyl peroxide, isobutyryl peroxide,
Octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m
-Diacyl peroxides such as toluoyl peroxide, di-isopropylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, di-
n-propylperoxydicarbonate, di-3-methoxybutylperoxydicarbonate, di-2-ethoxyethylperoxydicarbonate, di-methoxyisopropylperoxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydi Peroxycarbonates such as carbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, t-butylperoxyacetate, t-butylperoxyisobutyrate, t-butylperoxypiparate, t-butylper Oxyneodecanoate, cumylperoxyneodecanoate, t-butylperoxy 2-ethylhexanoate, t-butylperoxy 3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butyl peroxybe Peroxyesters such as zoate, di-t-butyldiperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxyisopropylcarbonate, acetylacetone peroxide, methyl ethyl ketone Ketone peroxides such as peroxide, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p- Menthan hydroperoxide, 2,5-dimethylhexane-2,
Hydroperoxides such as 5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, polyacyl peroxides of dibasic acids, and polyperoxyesters of dibasic acids and polyols One or more initiators can be used. However, the use of an organic peroxide is preferred because a high grafting efficiency is easily obtained. The amount of use is not particularly limited, but is preferably 0.001 to 5.0 parts by mass with respect to 100 parts by mass of the monomer mixture.

In the polymerization, chain transfer agents such as mercaptans, α-methylstyrene linear dimer, monoterpenoid molecular weight regulator (turbinolene) and hindered phenols, hindered bisphenols and hindered as antioxidants Trisphenols and the like, for example, 2,6-di-t-butyl-4-methylphenol, stearyl-β- (3,5-di-t-butyl-4)
-Hydroxyphenyl) propionate may be used.

The resins obtained by the above polymerization methods include:
Known antioxidants, for example 2,6-di-tert-butyl-4-methylphenol, 2- (1-methylcyclohexyl) 4,6-dimethylphenol, 2,2′-methylene-bis (4-ethyl-6 tert-butylphenol), 4,4'-thiobis- (6-tert-butyl-3-methylphenol), dilaurylthiodipropionate, tris (di-nonylphenyl) phosphite, inorganic stabilizers such as calcium and tin Known UV absorbers, for example p-tert-butylphenyl salicylate, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2- (2'-hydroxy-4'-n-octoxyphenyl) benzothiazole Known lubricants such as paraffin wax, stearic acid, hydrogenated oil, stearamide, methylene bis-stere; Roamido, n- butyl stearate, ketone wax, octyl alcohol,
Lauryl alcohol, hydroxystearic acid triglyceride; known flame retardants such as antimony oxide, aluminum hydroxide, zinc borate, tricresyl phosphate,
Chlorinated paraffins, tetrabromobutane, hexabromobutane, tetrabromobisphenol A; known antistatic agents, such as stearoamidopropyldimethyl-β-hydroxyethylammonium nitrate; known colorants, such as titanium oxide, carbon black, Other inorganic or organic pigments, known fillers such as calcium carbonate, clay, silica, glass fibers, glass spheres, and carbon fibers can be added as needed, but are not limited thereto. Further, when these additives are blended with the resin, the additives may be blended alone or a plurality of kinds of additives may be blended. Furthermore, it can be blended with another resin and provided for molding. Further, these additives may be added at an intermediate stage of the polymerization process. In addition, a modifier used in a styrene-based resin, an acrylic resin, or the like can be applied to modify the characteristics of the product surface such as a sheet or a film.

In the present invention, the molecular weight of the matrix resin can be controlled by changing the type, amount and timing of addition of the chain transfer agent. The particle size of the rubber-dispersed particles can be controlled by changing the stirring conditions, in addition to the type, amount and timing of addition of the chain transfer agent. In order to maintain transparency, a method that does not change the composition of the polymer formed during the polymerization is used. For example, a method of adding a monomer as needed during the polymerization, a method of continuously adding the monomer, and the like are used.

In the rubber-modified aromatic vinyl copolymer resin composition of the present invention, the continuous matrix has a refractive index substantially equivalent to that of the rubber-like polymer, and the structural unit is composed of at least one aromatic vinyl-based copolymer. Compound 20 to 80% by mass and one or more alkyl (meth) acrylate compounds 20 to 8
0% by mass, but one or more aromatic vinyl compounds, which are constituent units of the copolymer, are present in an amount of 40 to 6%.
A copolymer having 5% by mass and 35 to 60% by mass of one or more alkyl (meth) acrylate compounds is more preferred.

In order to make the refractive index of the continuous matrix substantially equal to that of the rubber-like polymer, the aromatic vinyl-based compound of the continuous matrix and the (meth) A method of controlling the ratio with the alkyl acrylate is used. For example, the ratio of the styrene structural unit contained in the rubbery polymer is X%, the refractive index of polystyrene is nPS, the refractive index of polybutadiene is nPB,
The ratio of the styrene monomer structural unit contained in the continuous matrix is Y%, and the refractive index of the styrene monomer structural unit is n.
Assuming that the refractive index of the S, alkyl (meth) acrylate structural unit is nM, the following formulas I, II, and III may be satisfied. | N1-n2 | ≦ 0.01 Formula I n1 = nPS × X ÷ 100 + nPB × (100−X) ÷ 100 Formula II n2 = nS × Y ÷ 100 + nM × (100−Y) ÷ 100 Formula III In Formula I, n1 is The refractive index of the rubbery polymer, n2
Is the refractive index of the continuous matrix. The values of nPS, nPB, nS, and nM in Formulas II and III are determined based on the type of the monomer used, for example, in a polymer handbook (Four
th Edition, VI / 571). Further, the ratio X% of the styrene structural unit contained in the rubbery polymer and the ratio Y% of the styrene monomer structural unit contained in the copolymer are represented by a volume fraction,
Either the weight fraction or the molar fraction may be used, and in any case, the formula I may be satisfied. Among these, the volume fraction or the weight fraction is preferably used, and particularly preferably the weight fraction is used. Thus, Formula I, Formula II, Formula II
From I, the aromatic vinyl compound of the copolymer and (meth)
The proportion of the alkyl acrylate can be determined.

In the rubber-modified aromatic vinyl copolymer resin composition of the present invention, the content of the rubbery polymer is 3 to 20% by mass, more preferably 5 to 20% by mass.
The rubbery polymer is present as dispersed particles in the resin composition of the present invention, and has an average particle size of 0.3 to
It is necessary that the particle diameter is in the range of 2.1 μm and the glass transition point of the dispersed particles is in the range of −75 to −30 ° C.
More preferably, the average particle size of the dispersed particles is 0.5 to
It is preferable that the particle diameter is in the range of 1.0 μm and the glass transition point of the dispersed particles is in the range of −70 to −35 ° C. If the average particle size exceeds 2.1 μm, the appearance becomes poor,
If it is less than 0.3 μm, the impact resistance is undesirably reduced. The average particle diameter referred to here is LS-230 (Beckman
Dimethylformamide was used as a dispersing agent, and the volume average value was determined. There is no particular limitation on the particle size distribution state, and any distribution state having a single peak distribution and a distribution state having a double mountain distribution may be used.

The resin used as an additive in the rubber-modified aromatic vinyl copolymer resin composition of the present invention includes hydrogenated coumarone resin, MBS resin, and styrene-butadiene block copolymer resin. It can be used alone or in combination. The molecular weight and molecular structure are not particularly limited, and the degree of hydrogenation in the hydrogenated coumarone resin, the block structure in the styrene-butadiene-based block copolymer resin, and the like can be arbitrarily determined. The effect of improving physical properties such as impact strength when these resins are added to the rubber-modified aromatic vinyl-based copolymer resin used in the present invention is smaller than that of the rubber-modified aromatic vinyl-based copolymer resin known so far. Large and transparency is not impaired. The content of these additives is 1 to 20% by mass based on the rubber-modified styrene resin. If it is less than 1% by mass, the effect of reinforcing the strength is insufficient, which is not preferable. If the content exceeds 20% by mass, the rigidity and the transparency are undesirably reduced.

The resin used as an additive in the present invention may be added by a known method or technique in the raw material solution, in the middle of the polymerization reactor, at the exit of the polymerization reactor, or at any point in the recovery system or the pelletization stage. Can be. It is also possible to knead using an extruder, or to blend with pellets at the time of molding and mix them in the molding machine.

From the obtained resin composition, various molded articles can be formed by injection molding or extrusion molding. Furthermore, it can be formed into a sheet or a film using a T-die sheet extruder, a casting machine, a biaxial stretching machine, and an inflation machine. The resulting molded article is used for covers, cases, household goods, etc. by utilizing its excellent transparency and impact resistance. In particular, it is useful as a material for styrene resin sheets and films, and can be suitably used as a food packaging container, daily goods packaging, or lamination sheet film.

[0027]

Embodiments of the present invention will be described below. First, the rubber-modified aromatic vinyl copolymer resin composition containing the rubbery polymer as dispersed particles of the present invention can be produced by a conventionally known method. That is,
A rubbery polymer is dissolved in a raw material solution comprising an aromatic vinyl compound and a (meth) acrylic acid alkyl ester compound, a polymerization solvent as necessary, and a polymerization initiator, in the presence or absence of a commonly used radical catalyst. , The raw material is supplied to a reactor equipped with a stirrer to carry out polymerization. The polymerization temperature can be determined in consideration of the fluidity and productivity of the rubber-modified aromatic vinyl copolymer resin, the heat removal capability of the reactor, and the like. After completion of the polymerization, a treatment under vacuum is performed to remove unreacted monomers, polymerization solvent, and the like, whereby a rubber-modified aromatic vinyl copolymer resin can be obtained.

[0028]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The data shown in Examples and Comparative Examples were measured according to the following methods. The molecular weight distribution of the styrene-butadiene block copolymer rubber was measured by the GPC method under the following conditions. Solvent (mobile phase): THF, deaerator: ER manufactured by ERMA
C-3310, pump: PU-980, manufactured by JASCO Corporation, flow rate: 1.0 ml / min, autosampler: AS-8, manufactured by Tosoh Corporation
020, column oven: L-5030 manufactured by Hitachi, Ltd.
Set temperature 40 ° C, Column composition: TSKgurdco manufactured by Tosoh Corporation
One lumn MP (× L) 6.0mmID × 4.0cm and TSK-GEL MULTIPORE HXL-M manufactured by Tosoh Corporation
7.8 mm ID × 30.0 cm 2 lines, 3 lines in total, detector: RI Hitachi L-3350, data processing: SIC480 data station. The glass transition point of the styrene-butadiene-based block copolymer rubber (A) is determined by using Seiko Denshi Kogyo's DSC-200 and SSC-5000 series,
The measurement was performed under the following conditions. From room temperature, the temperature is raised to the temperature of the melting point of polystyrene plus the temperature of alpha, held at that temperature for about 10 minutes, and cooled at a cooling rate of 20 to 25 ° C./min to the glass transition temperature of polybutadiene minus the temperature of alpha (n = 1). ), Raise the temperature again to the melting point of polystyrene plus the temperature of alpha, hold at that temperature for about 10 minutes,
The polybutadiene was cooled at a cooling rate of 25 ° C./min to the glass transition temperature minus alpha (n = 2) and the average of the two measurements was recorded.

The glass transition point of the dispersed particles dispersed in the rubber-modified aromatic vinyl- (meth) acrylic acid alkyl ester copolymer was determined by using a rubber-modified aromatic vinyl copolymer resin sample a
(Accurately weigh 1 g) with acetone / methyl ethyl ketone 4
/ 6 (volume ratio) was dispersed in 30 cc of a mixed solvent, the insoluble matter was separated by centrifugation and dried, and the styrene-based dispersion was obtained using DSC-200 and SSC-5000 series manufactured by Seiko Instruments Inc. The measurement was performed under the same conditions as in the measurement of the glass transition point of the butadiene-based block copolymer rubber (A). The microstructure of the styrene-butadiene block copolymer rubber, in particular, the vinyl bond content and the styrene content of the butadiene portion were determined by infrared spectroscopy (Hampton, Anal. C.).
Chem., 21, 923 (1949)), and the styrene solution viscosity was measured by an Ostwald viscometer. The graft ratio of the rubber-modified aromatic vinyl copolymer resin composition was determined by using the sample S1.
(Accurately weigh 1 g) with acetone / methyl ethyl ketone 4
/ 6 (volume ratio) in a mixed solvent of 30 cc, the insoluble matter is separated by a centrifugal separation method and dried, and the mass (S2) of the insoluble matter is precisely weighed and determined by the following formula 1. Here, S3 indicates the content of the rubbery polymer in the sample S1. {Equation 1} Graft ratio (g) = [(S2 / S1) -S3] / S3 × 100 The swelling index is obtained by measuring the sample S4 (about 1 g is precisely weighed) with toluene 30
After stirring for 1 hour to dissolve, the supernatant was removed by centrifugation, the mass of the remaining swelled product (S5) was precisely weighed, and then the remaining swelled product was vacuum-dried. It is a characteristic value determined by the following formula 2 from the result of precisely weighing the mass (S6) of the dry solid content to be obtained. {Equation 2} Swelling index = S5 / S6

The surface gloss, total light transmittance and haze were determined by JI
S-K7105, Charpy impact strength is JIS K-7
111 (notched), flexural modulus and flexural stress are J
ISK-7203, JIS K-7113 for tensile strength, tensile modulus and elongation, JIS for Vicat softening point
K-7206, fluidity at high temperature is JIS K-7
210, pencil hardness was measured according to JIS K-5400. Similarly, the drop weight impact strength was measured from a height of 62 cm using a drop weight graphic impact tester (trademark of an instrumented drop weight impact tester manufactured by Toyo Seiki Seisaku-sho) by molding a flat plate having a thickness of 2 mm with an injection molding machine. A heavy weight of 6.5 kg was naturally dropped on the plane of the test piece fixed to the holder (diameter 40 mm), and a striker (diameter 1) provided at the lower part of the weight weight was used.
2.7 mm) to completely break or penetrate the test piece, and the total energy required at this time (referred to as total absorbed energy) was measured. Further, the amount of the polybutadiene rubber component in the rubber-modified styrene copolymer resin composition was determined by a halogen addition method in which iodine chloride was added to a double bond and measured.

[0031]

EXAMPLE 1 A styrene-butadiene random copolymer (A) constituting the styrene-butadiene block copolymer rubber was prepared from styrene-butadiene random copolymer rubbers such as US Pat. No. 3,094,512. A method, that is, a production condition that generally satisfies the relationship of polymerization rate> styrene-butadiene mixed monomer supply rate under a certain condition, is generally used. The concrete implementation method is as follows. A stainless steel polymerization tank having an inner volume of 1000 L with a jacket, a coil and a stirrer is washed with cyclohexane dehydrated to a water content of 10 ppm or less, replaced with nitrogen, and then dehydrated to a water content of 10 ppm or less under a nitrogen gas atmosphere. 540 kg of cyclohexane containing 35 ppm of tetramethylethylenediamine
Was charged into a polymerization tank, and after raising the internal temperature to 80 ° C., 0.8 kg of a cyclohexane solution containing 10 wt% of n-butyllithium was added. Next, at a constant internal temperature of 80 ° C., a water content of 1
8.75 kg / h of styrene dehydrated to 0 ppm or less, and butadiene 35 dehydrated by passing through a molecular sieve
kg / h were fed simultaneously for 4 hours to carry out polymerization. afterwards,
Styrene dehydrated to a water content of 10 ppm or less
Add 5 kg, and add 1 kg as long as the maximum temperature does not exceed 120 ° C.
Polymerization was performed for 0 minutes to polymerize all the charged styrene.

Thereafter, the polymerization solution is transferred to the next reaction tank,
After 0.08 parts by mass of water was added to 100 parts by mass of the polymer to terminate the polymerization, carbon dioxide was added and neutralized during the transfer to the next reaction tank. Next, 2,4-bis is used as a stabilizer.
After adding [(octylthio) methyl] -O-cresol at a rate of 0.2% to the polymer, the solvent was removed by steam stripping, and the mixture was dried with a hot roll at 100 ° C. to form a styrene-butadiene block. A polymer rubber was obtained. 7.9% by mass of the styrene-butadiene block copolymer rubber was used as 46.6% by mass of a styrene monomer, 32.5% by mass of methyl methacrylate, and butyl acrylate.
100 parts by mass of a solution dissolved in 6% by mass and 8.4% by mass of ethylbenzene are mixed with 1,1-bis (tert-butylperoxyl) 3,3,5-trimethylcyclohexane 0.0
A solution consisting of 15 parts by mass was continuously fed into the first polymerization machine, and a polymerization reaction with stirring was carried out at a polymerization temperature of 125 ° C., followed by continuously charging the whole amount into a plug flow type reactor for polymerization. Thereafter, the mixture was polymerized to a polymerization rate of 85%, and the solution was fed to a vented extruder to remove volatile components at 230 ° C. under reduced pressure, to draw out a molten strand from a die, water-cooled, cut with a cutter, and pelletized. Resin was obtained. At this time,
Hydrogenated coumarone resin (S-Crystal A-12 manufactured by Nippon Steel Chemical Co., Ltd.) is used per 100 parts by mass of the rubber-modified styrene resin.
OS) 5 parts by mass were fed to a vented extruder. Tables 1 and 2 show various analytical values and solid physical property evaluation results.

[0033]

Example 2 The styrene-butadiene random copolymer (A) constituting the styrene-butadiene-based block copolymer rubber was produced from styrene-butadiene-based random copolymer rubbers such as US Pat. No. 3,094,512. A method, that is, a production condition that generally satisfies the relationship of polymerization rate> styrene-butadiene mixed monomer supply rate under a certain condition, is generally used. The concrete implementation method is as follows. A stainless steel polymerization tank having an inner volume of 1000 L with a jacket, a coil and a stirrer is washed with cyclohexane dehydrated to a water content of 10 ppm or less, replaced with nitrogen, and then dehydrated to a water content of 10 ppm or less under a nitrogen gas atmosphere. Then, 540 kg of cyclohexane containing 35 ppm of trimethylethylenediamine was charged into the polymerization tank, and after raising the internal temperature to 80 ° C., 0.8 kg of a cyclohexane solution containing 10 wt% of n-butyllithium was added. Next, at a constant internal temperature of 80 ° C., a water content of 10
3.89 kg / h of styrene dehydrated to less than ppm and 35 k of butadiene dehydrated by passing through a molecular sieve
g / h were fed simultaneously for 4 hours to carry out polymerization. Then, styrene dehydrated to a water content of 10 ppm or less at 80.degree.
kg, and the maximum temperature should not exceed 120 ° C.
The polymerization was carried out for minutes, and all of the charged styrene was polymerized.

Thereafter, the polymerization solution is transferred to the next reaction tank,
After 0.08 parts by mass of water was added to 100 parts by mass of the polymer to terminate the polymerization, carbon dioxide was added and neutralized during the transfer to the next reaction tank. Next, 2,4-bis is used as a stabilizer.
[(Octylthio) methyl] -O-cresol was added at a rate of 0.2% to the polymer, the solvent was removed by steam stripping, dried with a hot roll at 100 ° C, and dried with a styrene-butadiene block. A heavy rubber was obtained. 7.9% by mass of the styrene-butadiene block copolymer rubber was used as 46.6% by mass of a styrene monomer, 32.5% by mass of methyl methacrylate, and butyl acrylate.
100 parts by mass of a solution dissolved in 6% by mass and 8.4% by mass of ethylbenzene are mixed with 1,1-bis (tert-butylperoxyl) 3,3,5-trimethylcyclohexane 0.0
A solution consisting of 15 parts by mass was continuously fed into the first polymerization machine, and a polymerization reaction with stirring was carried out at a polymerization temperature of 125 ° C., followed by continuously charging the whole amount into a plug flow type reactor for polymerization. Thereafter, the mixture was polymerized to a polymerization rate of 85%, and the solution was fed to a vented extruder to remove volatile components at 230 ° C. under reduced pressure, to draw out a molten strand from a die, water-cooled, cut with a cutter, and pelletized. Resin was obtained. At this time,
Five parts by mass of MBS resin (BTA723 manufactured by Kureha Chemical Co., Ltd.) was supplied to the vented extruder per 100 parts by mass of the rubber-modified styrene resin. Tables 1 and 2 show various analytical values and solid physical property evaluation results.

[0035]

Embodiment 3 The styrene-butadiene tapered copolymer block portion (A) constituting the styrene-butadiene block copolymer rubber is a styrene-butadiene random copolymer rubber such as US Pat. No. 3,094,512. In other words, it can be obtained by applying a production method that satisfies the relationship of polymerization rate> supply rate of styrene-butadiene mixed monomer under certain conditions. That is, polymerization is performed while supplying a monomer mixture having a desired butadiene / styrene composition ratio at a polymerization rate or lower, and then supplying a monomer mixture having a different butadiene / styrene composition ratio at a polymerization rate or lower, By repeating this operation one or more times, the styrene-butadiene tapered copolymer block (A) constituting the styrene-butadiene-based block copolymer rubber used in the present invention can be synthesized.

A specific implementation method will be described. Internal volume 10
A stainless steel polymerization tank equipped with a 00 L jacket, coil and stirrer was washed with cyclohexane dehydrated to a water content of 10 ppm or less, and after nitrogen replacement, 540 kg of cyclohexane containing 35 ppm of trimethylethylenediamine was dehydrated under a nitrogen gas atmosphere to a water content of 10 ppm or less. After charging into a polymerization tank and raising the internal temperature to 80 ° C, n-butyl lithium 10
0.8 kg of a wt% cyclohexane solution was added. Next, under a constant internal temperature of 80 ° C., styrene dehydrated to a water content of 10 ppm or less and butadiene dehydrated by passing through a molecular sieve were obtained by changing a specific feed rate and polymerization time in six stages. Feeding and polymerization were carried out at the same time, and the feed rate and polymerization time at this time were as follows.
First stage: 2.6 kg / h of styrene, butadiene
9 kg / h, polymerization time 1.3 hours. Second stage: styrene 6.1 kg / h, butadiene 32.8 kg / h, polymerization time 1.2 hours. Third stage: styrene 8.7 kg / h, butadiene 25.9 kg / h, polymerization time 1.0 hour. Fourth stage: styrene 8.1 kg / h, butadiene 14.9 k
g / h, polymerization time 1.0 hour. Fifth stage: styrene
7 kg / h, butadiene 10.5 kg / h, polymerization time 1.2 hours. Sixth stage: styrene 7.8 kg / h, butadiene 5.0 kg / h, polymerization time 0.9 hour.

Thereafter, 45 kg of styrene dehydrated to a water content of 10 ppm or less was added at 80 ° C.
Polymerization was performed for 10 minutes at a temperature not exceeding ℃, and all of the charged styrene was polymerized. Thereafter, the polymerization solution was transferred to the next reaction tank, water was added to 0.08 parts by mass with respect to 100 parts by mass of the polymer to stop the polymerization, and then carbon dioxide was added during the transfer to the next reaction tank. Summed up. Next, 2,4-bis [(octylthio) methyl] -O-cresol was added as a stabilizer at a ratio of 0.2% to the polymer, and the solvent was removed by steam stripping. To obtain a styrene-butadiene block copolymer rubber. 7.9% by mass of the styrene-butadiene block copolymer rubber was used as 46.6% by mass of a styrene monomer, 32.5% by mass of methyl methacrylate, and butyl acrylate.
100 parts by mass of a solution dissolved in 6% by mass and 8.4% by mass of ethylbenzene are mixed with 1,1-bis (tert-butylperoxyl) 3,3,5-trimethylcyclohexane 0.0
A solution consisting of 15 parts by mass was continuously fed into the first polymerization machine, and a polymerization reaction with stirring was carried out at a polymerization temperature of 125 ° C., followed by continuously charging the whole amount into a plug flow type reactor for polymerization. Thereafter, the mixture was polymerized to a polymerization rate of 85%, and the solution was fed to a vented extruder to remove volatile components at 230 ° C. under reduced pressure, to draw out a molten strand from a die, water-cooled, cut with a cutter, and pelletized. Resin was obtained. At this time,
Per 100 parts by mass of the rubber-modified styrenic resin, styrene-
5 parts by mass of a butadiene-based block copolymer resin (TR-2000 manufactured by Nippon Synthetic Rubber Co., Ltd.) was supplied to a vented extruder. Tables 1 and 2 show various analytical values and solid physical property evaluation results.

[0038]

Comparative Example 1 The procedure of Example 1 was repeated except that no hydrogenated coumarone resin was used. Tables 1 and 3 show various analytical values and solid physical property evaluation results.

[0039]

Comparative Example 2 The procedure of Example 2 was repeated except that no MBS resin was used. Tables 1 and 3 show various analytical values and solid physical property evaluation results.
Shown in

[0040]

Comparative Example 3 The procedure of Example 3 was repeated except that the styrene-butadiene block copolymer resin was not used. Tables 1 and 3 show various analytical values and solid physical property evaluation results.

[0041]

Comparative Example 4 7.9% by mass of a styrene-butadiene block copolymer rubber (NS-316S manufactured by Nippon Zeon Co.) was used in an amount of 46.6% by mass of a styrene monomer, and methyl methacrylate 3 was used.
2.5 mass%, 100 mass parts of a solution dissolved in 4.6 mass% of butyl acrylate and 8.4 mass% of ethylbenzene, and 1,1-bis (tert-butylperoxyl) 3;
A solution consisting of 0.015 parts by mass of 3,5-trimethylcyclohexane is continuously fed into the first polymerization machine, and after stirring polymerization at a polymerization temperature of 125 ° C., the whole amount is continuously fed into a plug flow reactor. It was charged and polymerized. Thereafter, the mixture was polymerized to a polymerization rate of 85%, and the solution was fed to a vented extruder to remove volatile components at 230 ° C. under reduced pressure, to draw out a molten strand from a die, water-cooled, cut with a cutter, and pelletized. Resin was obtained. At this time, 5 parts by mass of a hydrogenated coumarone resin (S-Crystal A-12OS manufactured by Nippon Steel Chemical Co., Ltd.) was supplied to the vented extruder per 100 parts by mass of the rubber-modified styrene resin. Tables 4 and 5 show various analytical values and solid physical property evaluation results.

[0042]

Comparative Example 5 7.9% by mass of a styrene-butadiene block copolymer rubber (NS-312S manufactured by Nippon Zeon Co.) was used in an amount of 46.6% by mass of a styrene monomer, and methyl methacrylate 3 was used.
2.5 mass%, 100 mass parts of a solution dissolved in 4.6 mass% of butyl acrylate and 8.4 mass% of ethylbenzene, and 1,1-bis (tert-butylperoxyl) 3;
A solution consisting of 0.015 parts by mass of 3,5-trimethylcyclohexane is continuously fed into the first polymerization machine, and after stirring polymerization at a polymerization temperature of 125 ° C., the whole amount is continuously fed into a plug flow reactor. It was charged and polymerized. Thereafter, the mixture was polymerized to a polymerization rate of 85%, and the solution was fed to a vented extruder to remove volatile components at 230 ° C. under reduced pressure, to draw out a molten strand from a die, water-cooled, cut with a cutter, and pelletized. Resin was obtained. At this time, 5 parts by mass of MBS resin (BTA723 manufactured by Kureha Chemical Co., Ltd.) was supplied to the vented extruder per 100 parts by mass of the rubber-modified styrene resin. Table 4 shows various analytical values and solid physical property evaluation results.
It is shown in FIG.

[0043]

Comparative Example 6 7.9% by mass of a styrene-butadiene block copolymer rubber (670A, manufactured by Nippon Elastomer Co.) was used in an amount of 46.6% by mass of a styrene monomer, and methyl methacrylate 3 was used.
2.5 mass%, 100 mass parts of a solution dissolved in 4.6 mass% of butyl acrylate and 8.4 mass% of ethylbenzene, and 1,1-bis (tert-butylperoxyl) 3;
A solution consisting of 0.015 parts by mass of 3,5-trimethylcyclohexane is continuously fed into the first polymerization machine, and after stirring polymerization at a polymerization temperature of 125 ° C., the whole amount is continuously fed into a plug flow reactor. It was charged and polymerized. Thereafter, the mixture was polymerized to a polymerization rate of 85%, and the solution was fed to a vented extruder to remove volatile components at 230 ° C. under reduced pressure, to draw out a molten strand from a die, water-cooled, cut with a cutter, and pelletized. Resin was obtained. At this time, a styrene-butadiene-based block copolymer resin (TR-20 manufactured by Nippon Synthetic Rubber Co., Ltd.) was used per 100 parts by mass of the rubber-modified styrene-based resin.
00) 5 parts by mass were fed to a vented extruder. Tables 4 and 5 show various analytical values and solid physical property evaluation results.

[0044]

Comparative Example 7 The procedure of Comparative Example 4 was repeated except that no hydrogenated coumarone resin was used. Tables 4 and 6 show various analytical values and evaluation results of solid physical properties.

[0045]

Comparative Example 8 The procedure of Comparative Example 5 was repeated except that no MBS resin was used. Tables 4 and 6 show various analytical values and solid physical property evaluation results.
Shown in

[0046]

Comparative Example 9 The procedure of Comparative Example 6 was repeated except that the styrene-butadiene block copolymer resin was not used. Tables 4 and 6 show various analytical values and evaluation results of solid physical properties.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

[Table 3]

[0050]

[Table 4]

[0051]

[Table 5]

[0052]

[Table 6]

[0053]

As described above, the present invention relates to a rubber-modified aromatic vinyl copolymer resin using a styrene-butadiene block copolymer having a specific range of Tg, a hydrogenated coumarone resin, MBS resin, styrene-butadiene. By containing the system block copolymer resin as an additive, the practical properties of the transparent composition, particularly the Charpy impact strength and the falling weight impact strength, are remarkably improved. Furthermore, it has excellent moldability and is suitable for molding, sheet processing, foam molding and the like. Further, the present invention provides a production method that can utilize a known production method, and its industrial value is extremely large.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 53:02) C08L 53:02) F-term (Reference) 4J002 BK002 BN161 BN162 BN211 BP012 GG01 GG02 4J026 AC11 AC16 BA04 BA05 BA06 BA08 BA27 GA09

Claims (4)

[Claims] 1. A rubber-modified aromatic vinyl copolymer resin containing a rubbery polymer as dispersed particles in a continuous matrix resin, wherein (1) the continuous matrix has a refractive index substantially equal to that of the rubbery polymer. Having a structural unit of 20 to 80% by mass of one or more aromatic vinyl compounds and 20 to 8 of one or more alkyl (meth) acrylate compounds
For 97 to 80% by mass of the copolymer, which is 0% by mass,
(2) The content of the rubbery polymer of 3 to 20% by mass,
The glass transition point of the dispersed particles is in the range of −75 to −30 ° C., and the average particle size of the dispersed particles is 0.3 to 2.1 μm.
m, the rubber-modified aromatic vinyl copolymer resin 99 to 8
0% by mass, hydrogenated coumarone resin as an additive,
1 to 20% by mass of a resin selected from the group consisting of MBS resin and styrene-butadiene block copolymer resin
A transparent rubber-modified aromatic vinyl copolymer resin composition characterized by containing: 2. The aromatic vinyl compound is styrene,
2. The transparent rubber-modified aromatic vinyl copolymer resin composition according to claim 1, wherein the alkyl (meth) acrylate compound is methyl methacrylate alone or a mixture of methyl methacrylate and butyl acrylate. 3. The rubbery polymer dispersed in the rubber-modified aromatic vinyl copolymer resin component in the form of particles is a block portion (A) composed of a random or tapered copolymer of styrene and butadiene, and a styrene homopolymer. Or a block copolymer comprising a styrene-butadiene copolymer block part (B) composed mostly of styrene; Vinyl copolymer resin composition. 4. A mass ratio of a block portion (A) composed of a random or tapered copolymer of styrene and butadiene in a rubbery polymer dispersed in a particle form in a rubber-modified aromatic vinyl copolymer resin component. The mass ratio of the styrene-butadiene copolymer block part (B) composed of 15 to 95% by mass, styrene homopolymer or most of styrene is 85 to 5% by mass. 4. The transparent rubber-modified aromatic vinyl copolymer resin composition according to item 1.