JPH08193161A - High-impact transparent resin composition - Google Patents

Abstract

PURPOSE: To obtain a resin compsn. improved in resistance to plane impact, stiffness, and transparency by compounding a specific block copolymer with a rubber-modified polystyrene. CONSTITUTION: A conjugated diene and a vinylarom. hydrocarbon are subjected to block copolymn. at-100 deg.C to 150 deg.C for 1-10hr in the presence of an anionic initiator in a hydrocarbon solvent, giving a block copolymer comprising at least two polymer blocks mainly comprising vinylarom. hydrocarbon units and at least one polymer block mainly comprising conjugated diene units and having a content of vinylarom. hydrocarbon units of 65-90wt.%. 70-99.5wt.% block copolymer obtd. as above is compounded with 0.5-30wt.% rubber-modified polystyrene which is obtd. by grafting styrene onto a rubberlike butadiene polymer, contains dispersed particles contg. polystyrene and having an average particle size of 0.5-10μm, and has a polystyrene content of 75-90wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition comprising a block copolymer and a rubber-modified polystyrene having dispersed particles having a specific structure and having excellent surface impact resistance, rigidity and transparency. It is a resin composition that is utilized in the fields of injection molding and sheet molding by taking advantage of its characteristics.

[0002]

2. Description of the Related Art Conventionally, a block copolymer resin composed of a vinyl aromatic hydrocarbon and a conjugated diene can be easily molded by extrusion molding, injection molding, blow molding, vacuum molding, etc., so that food molding containers, household products, etc. It is used in a wide range of applications as a material for electric parts, industrial products, etc.

However, even though these block copolymer resins are transparent, they are not always satisfactory in terms of the balance between rigidity and impact resistance. Therefore,
Various methods have been tried for the purpose of these improvements. Japanese Patent Publication No. 52-16496, Japanese Patent Publication No. 59-37
No. 299, a composition comprising rubber-modified polystyrene and a styrene-butadiene block copolymer has an impact strength,
It is disclosed that it is excellent in elongation, whitening in folds, fin properties and surface gloss. JP-A-54-62251 and JP-A-52-136253 disclose a composition of a block copolymer resin and polystyrene as means for improving rigidity, and JP-A-57-21442 and KAISHO 59-187048 discloses a composition of a block copolymer resin and an elastomer having a low styrene content as a means for improving impact resistance.

[0004]

SUMMARY OF THE INVENTION The above-mentioned composition comprising the rubber-modified polystyrene and the styrene-butadiene block copolymer described in the prior art cannot provide sufficient transparency, and the block copolymer In the composition of the combined resin and polystyrene, the rigidity is improved, but the transparency and impact resistance are lowered, and the rigidity is lowered in the composition of the block copolymer resin and the elastomer having a small styrene content, A resin composition excellent in impact resistance, rigidity and transparency has been desired.

[0005]

DISCLOSURE OF THE INVENTION In view of the above situation, the present inventors have conducted extensive studies to obtain a resin composition having excellent impact resistance, rigidity and transparency, and as a result, dispersion of a block copolymer and a specific structure. It was found that the above object was achieved by a composition with rubber-modified polystyrene having particles, and the present invention was completed. That is, the present invention includes: (a) a polymer block containing at least two vinyl aromatic hydrocarbons as a main component and at least one polymer block containing a conjugated diene as a main component, and having a vinyl aromatic hydrocarbon content of 65 to 90% by weight of a block copolymer 70 to 99.5% by weight, and (b) a rubber-modified polystyrene obtained by graft-polymerizing styrene to a butadiene-based rubber-like polymer, wherein Including polystyrene, and the average particle size of dispersed particles is 0.5 to 10
.mu.m, the rubber-modified polystyrene having a polystyrene content of the dispersed particles of 75% by weight to 90% by weight.
An impact-resistant transparent resin composition comprising 30% by weight, wherein the content of polystyrene in the dispersed particles of (b) is more than 80% by weight and 90% by weight or less. A transparent resin composition, and an impact-resistant transparent resin composition comprising 100 parts by weight of the transparent impact-resistant resin composition described above and 1 to 150 parts by weight of a styrene-based polymer. The present invention also provides the impact-resistant transparent resin composition as described above, wherein the styrene-based polymer is a non-rubber-modified styrene-based polymer.

The present invention will be described in detail below. The block copolymer used in the present invention is a block copolymer having at least two vinyl aromatic hydrocarbon-based polymer blocks and at least one conjugated diene-based polymer block. Here, the polymer block mainly composed of vinyl aromatic hydrocarbon means a copolymer block of vinyl aromatic hydrocarbon containing 50% by weight or more of vinyl aromatic hydrocarbon and a conjugated diene and / or vinyl aromatic A hydrocarbon homopolymer block, and a polymer block containing a conjugated diene as a main component means a conjugated diene containing a conjugated diene in an amount exceeding 50% by weight and a vinyl aromatic hydrocarbon copolymer block and / or a conjugated diene alone. Refers to a polymer block.

If a random copolymer portion of a vinyl aromatic hydrocarbon and a conjugated diene is present in a polymer block mainly containing a vinyl aromatic hydrocarbon or a polymer block mainly containing a conjugated diene, they are copolymerized. Vinyl aromatic hydrocarbons are evenly distributed in the polymer block,
It may be distributed in a tapered shape. In addition, a plurality of portions where the vinyl aromatic hydrocarbon is evenly distributed and / or portions where the vinyl aromatic hydrocarbon is distributed may coexist in the copolymer portion.

The block copolymer used in the present invention can be basically produced by a conventionally known method. For example, JP-B-36-19286, JP-B-43-17979 and JP-B-48-2423. Gazette, Japanese Patent Publication No. Sho 49-36
The methods described in Japanese Patent Publication No. 957, Japanese Patent Publication No. 57-49567, Japanese Patent Publication No. 58-11446, and the like can be mentioned. However, the production conditions of each constituent polymer must be set so as to satisfy the requirements described later. . All of the above known methods are methods of block copolymerizing a conjugated diene and a vinyl aromatic hydrocarbon in an hydrocarbon solvent using an anionic initiator such as an organic lithium compound. The polymer structure of the block copolymer used in the present invention is, for example,

[0009]

Embedded image A- (BA) _n , A- (BA) _n -B, B
-(AB) _{n + 1} [In the above formula, A is a polymer block mainly containing a vinyl aromatic hydrocarbon, and B is a polymer block mainly containing a conjugated diene. The boundary between the A block and the B block does not necessarily have to be clearly distinguished. n is an integer of 1 or more, generally 1 to 5. ] The linear block copolymer represented by, or

[0010]

Embedded image General formula; [(AB) _k ] _{m + 2-} X, [(AB) _k- A] _{m + 2}
-X, [(B-A) _k ] _{m + 2-} X, [(B-A) _k-
B] _{m + 2-} X [In the above formula, A and B are the same as defined above, and k and m
Is an integer of 1 or more, generally 1 to 5. X represents a residue of a coupling agent such as silicon tetrachloride or tin tetrachloride or a residue of an initiator such as a polyfunctional organolithium compound. ] A radial block copolymer represented by the following, or a mixture of these block copolymers having an arbitrary polymer structure can be used.

As the vinyl aromatic hydrocarbon used in the present invention, styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, Examples thereof include vinyl anthracene and 1,1-diphenylethylene, but styrene is particularly commonly used. These may be used alone or in combination of two or more. The conjugated diene is a diolefin having a pair of conjugated double bonds, such as 1,3-butadiene and 2
-Methyl-1,3-butadiene (isoprene), 2,3
-Dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene and the like can be mentioned, but in general, 1,3-butadiene, isoprene and the like can be mentioned. These may be used alone or in combination of two or more.

Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as butane, pentane, hexane, isopentane, heptane and octane, alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane and ethylcyclohexane, or Aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene can be used. These may be used alone or in combination of two or more.

Examples of the organic lithium compound include organic monolithium compounds, organic dilithium compounds and organic polylithium compounds having one or more lithium atoms bonded in the molecule. Specific examples of these include ethyl lithium, n-propyl lithium, isopropyl lithium, and n.
-Butyl lithium, sec-butyl lithium, tert
-Butyl lithium, hexamethylene dilithium, butadienyl dilithium, isoprenyl dilithium and the like. These may be used alone or in combination of two or more.

In the present invention, for the purpose of adjusting the polymerization rate, changing the microstructure of the polymerized conjugated diene part (ratio of cis, trans, vinyl), adjusting the reaction ratio of the conjugated diene and the vinyl aromatic hydrocarbon, etc. Polar compounds and randomizing agents can be used. Examples of polar compounds and randomizing agents include tetrahydrofuran, ethers such as diethylene glycol dimethyl ether and diethylene glycol dibutyl ether, amines such as triethylamine and tetramethylethylenediamine, thioethers, phosphines, phosphoramides, alkylbenzene sulfonates, potassium and sodium salts. Examples include alkoxides.

The polymerization temperature for producing the polymer in the method of the present invention is generally in the range of -10 ° C to 150 ° C, preferably 40 ° C to 120 ° C. Although the time required for the polymerization varies depending on the conditions, it is usually 48 hours or less, and particularly preferably 1 to 10 hours. Further, it is desirable to replace the atmosphere of the polymerization system with an inert gas such as nitrogen gas. The polymerization pressure is not particularly limited as long as it is within the above-mentioned polymerization temperature range and is a pressure sufficient to maintain the monomer and the solvent in the liquid layer. Further, it is necessary to take care so that impurities that inactivate the catalyst and the living polymer, such as water, oxygen, carbon dioxide gas, do not enter the polymerization system.

The block copolymer used in the present invention has a vinyl aromatic hydrocarbon content of 65 to 90% by weight, preferably 70 to 85% by weight. The block copolymer has a vinyl aromatic hydrocarbon content of 65% by weight.
If it is less than 100% by weight, the rigidity and transparency of the resin composition molded article are deteriorated.

The preferred range of the block ratio of the vinyl aromatic hydrocarbon polymer block of the block copolymer used in the present invention is 50 to 100% by weight. When the block rate is less than 50% by weight, the rigidity of the resin composition molded article is poor, which is not preferable. The block ratio of the vinyl aromatic hydrocarbon block is the weight of the vinyl aromatic hydrocarbon and the conjugated diene in the step of copolymerizing at least a part of the vinyl aromatic hydrocarbon and the conjugated diene during the production of the block copolymer,
It can be controlled by changing the weight ratio, the polymerization reactivity ratio and the like. As a specific method, (a) a mixture of a vinyl aromatic hydrocarbon and a conjugated diene is continuously supplied to a polymerization system for polymerization, and / or (b) a polar compound or a randomizing agent is used. Then, a method such as copolymerizing a vinyl aromatic hydrocarbon and a conjugated diene can be adopted.

Examples of polar compounds and randomizing agents include ethers such as tetrahydrofuran, diethylene glycol dimethyl ether and diethylene glycol dibutyl ether, amines such as triethylamine and tetramethylethylenediamine, thioethers, phosphines, phosphoramides, alkylbenzene sulfonates, potassium salts. And sodium alkoxide. Incidentally, the block ratio of the vinyl aromatic hydrocarbon polymer block incorporated in the block copolymer in the present invention,
A method of oxidatively decomposing a block copolymer with di-tert-butyl hydroperoxide using osmium tetroxide as a catalyst [I. M. KOLTHOFF, eta
l. , J. et al. Polym. Sci. 1,429 (194
The method described in 6)], the vinyl aromatic hydrocarbon polymer block component (however, the vinyl aromatic hydrocarbon polymer component having an average degree of polymerization of about 30 or less is excluded) is quantified, and the following formula is obtained. The value obtained from

[0019]

[Equation 1]

The molecular weight of the block copolymer used in the present invention can be optionally adjusted by the amount of the catalyst used for polymerization, but from the viewpoint of moldability, the melt flow index (JIS
K-6870 was measured under the conditions of G, temperature of 200 ° C., weight of 5 Kg) of 0.1 to 100 g / 10 minutes,
It is preferably in the range of 1 to 50 g / 10 minutes. If desired, the block copolymer used in the present invention can be hydrogenated in the presence of a hydrogenation catalyst in an inert solvent and used as a hydrogenated product. A specific method is as follows:
The methods described in Japanese Patent Publication No. 8704 and Japanese Patent Publication No. 43-6636, and more preferably, the methods described in Japanese Patent Publication No. 63-4841 and Japanese Patent Publication No. 63-5401.

The compounding amount of the block copolymer of the resin composition of the present invention is 70 to 99.5% by weight, preferably 80 to 9%.
It is in the range of 9.0% by weight. If the amount of the block copolymer is less than 70% by weight, the transparency is lowered, and if it exceeds 99.5% by weight, the surface impact resistance is lowered, which is not preferable. The rubber-modified polystyrene of the present invention is obtained by polymerizing a butadiene rubber-like polymer, alone or in a mixture of styrene, α-methylstyrene, vinyltoluene, P-methylstyrene, vinylxylene, vinylnaphthalene and the like. The butadiene rubber-like polymer of the rubber-modified polystyrene of the present invention is
Polybutadiene, styrene-butadiene copolymer, styrene-butadiene block copolymer are used. or,
The molecular weight and degree of branching of the butadiene-based polymer are not limited.

The amount of the butadiene rubber-like polymer of the rubber-modified polystyrene of the present invention is not particularly limited, but it is preferably in the range of 1 to 15% by weight. The rubber-modified polystyrene of the present invention is produced by a method which is widely used in the production of conventionally known rubber-modified polystyrene (HIPS resin), that is, bulk polymerization, bulk-suspension polymerization, emulsion polymerization and the like. The particle size of the dispersed particles made of the butadiene rubber-like polymer can be determined by a known method such as stirring strength, the molecular weight of the styrene-based polymer produced, the amount of the molecular weight modifier, the amount of the solvent, and the molecular weight of the butadiene-based rubber-like polymer used. It is adjusted by changing the amount of the polymerization initiator. The amount of dispersed particles (gel amount) and the swelling index are adjusted by controlling the temperature of the recovery system of the method generally used in the method for producing rubber-modified polystyrene.

The rubber-modified polystyrene dispersed particles of the present invention have a structure in which polystyrene is contained therein, and the form thereof may be a salami structure or a core-shell structure. Although the content of polystyrene in the dispersed particles of the rubber-modified polystyrene of the present invention is adjusted by the styrene content in the butadiene rubber-like polymer used in the production of the rubber-modified polystyrene and the content of styrene contained and grafted in the dispersed particles. In addition, the rubber-modified polystyrene obtained by the above-mentioned method is dissolved in a styrene monomer, and benzoyl peroxide, t-butyl peroxide, di-t-butyl peroxide, 1,1-bis (t- (Butylpa-oxy) 3,3,5-trimethylcyclohexane, dicumylperoxide, etc. In the presence of an organic peroxide or the like, this solution is heated under stirring to radically polymerize to increase the polystyrene graft amount of the dispersed particles. Any method may be used.

The polystyrene content of the dispersed particles of the rubber-modified polystyrene of the present invention is a value obtained from the following formula.

[Equation 2]

The amount of polystyrene in the dispersed particles can be determined by pyrolysis gas chromatography, infrared spectroscopic analysis, block rate measurement described in the present invention and the like. The content of polystyrene in the dispersed particles of the rubber-modified polystyrene of the present invention is 75% by weight to 90% by weight, preferably 80% by weight.
And 90% by weight or less. If it is less than 75% by weight, the transparency of the resin composition molded article will be inferior, and if it exceeds 90% by weight, the surface impact resistance will be lowered, such being undesirable. The average particle size of the dispersed particles of the rubber-modified polystyrene of the present invention is 0.5 to
It is in the range of 10 μm, preferably in the range of 1 to 5 μm.
When it is less than 0.5 μm, the surface impact resistance of the resin composition molded product is low, and when it exceeds 10 μm, the transparency of the molded product is poor, which is not preferable. The average particle size of the dispersed particles is obtained by taking a transmission electron microscope photograph (magnification: 10,000 times) and measuring about 100 to 200 dispersed particles in the photograph.

The average particle diameter was calculated by the following formula.

## EQU3 ## Average particle size = ΣNiDi ⁴ / ΣNiDi ³ (wherein Ni represents the number of dispersed particles having a particle diameter Di). The amount of rubber-modified polystyrene of the resin composition of the present invention is
It is in the range of 0.5 to 30% by weight, preferably 1 to 20% by weight. If the amount of the rubber-modified polystyrene is less than 0.5% by weight, the surface impact resistance is lowered, and if it exceeds 30% by weight, the transparency is lowered, which is not preferable.

The styrene-based polymer which may be blended with the specific rubber-modified polystyrene in the present invention is a rubber-modified polystyrene excluding the specific rubber-modified polystyrene of the present invention,
Examples thereof include a styrene-acrylic acid ester copolymer having a rubber-like elastic material as dispersed particles and a non-rubber-modified styrene-based polymer. The dispersed particle diameter of the rubber-like elastic body of the styrene-acrylic acid ester copolymer having the rubber-like elastic body as dispersed particles is 0.1 to 1.2 μm, which is similar to the rubber particles in the rubber-modified polystyrene of the present invention. Means The preferred acrylic acid ester is one or more of methyl methacrylate, butyl acrylate, butyl methacrylate and the like. Examples of the non-rubber-modified styrene polymer include polystyrene, styrene-α-methylstyrene copolymer, acrylonitrile-styrene copolymer, styrene-methacrylic acid ester copolymer, and styrene-maleic anhydride copolymer. Particularly preferred is polystyrene. These can be used alone or as a mixture of two or more kinds.

The blending amount of the styrenic polymer in the resin composition of the present invention is 1 to 150 parts by weight, preferably 5 parts by weight, based on 100 parts by weight of the sum of the components (a) and (b).
-100 to 100 parts by weight, and if it exceeds 150 parts by weight, the surface impact resistance decreases, which is not preferable. The resin composition of the present invention can be produced by any conventionally known compounding method. For example, an open roll, an intensive mixer, an internal mixer, a co-kneader, a continuous kneader with a twin-screw rotor, a melt-kneading method using a general kneader such as an extruder, each component is dissolved or dispersed in a solvent and then mixed with a solvent. And the like are used.

The resin composition of the present invention may contain any additive as required. The kind of the additive is not particularly limited as long as it is one generally used for compounding plastics, for example, glass fiber, glass beads, silica,
Inorganic reinforcing agents such as calcium carbonate and talc; organic reinforcing agents such as organic fibers and coumarone indene resin; cross-linking agents such as organic peroxides and inorganic peroxides; pigments such as titanium white, carbon black and iron oxides; dyes, difficult Examples include flame retardants, antioxidants, ultraviolet absorbers, antistatic agents, lubricants, plasticizers, other extenders, and mixtures thereof.

The resin composition of the present invention can be used as it is, or after being colored and molded by the same processing means as a usual thermoplastic resin, for any purpose. For example, it can be used for containers of OA equipment parts, daily necessities, foods, miscellaneous goods, light electric parts, etc. by injection molding, blow molding, etc. In addition, food containers, fruits and vegetables, which are thermoformed by methods such as vacuum forming and pressure forming of extruded products such as sheets and films.
It can be used in a wide range of applications such as confectionery containers.

[0031]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but these do not limit the scope of the present invention. Block Copolymer of Component (a) Table 1 shows the block copolymer of component (a) used in Examples and Comparative Examples. The block copolymers of A-1 to A-7 used n-butyllithium as an initiator in a cyclohexane solvent, added cyclohexane solutions of monomers in the order shown in the polymer structure to polymerize, and terminated the polymerization with methanol. Then, 2- (2-hydroxy-3-t-butyl-5-methylbenzyl) -4-methyl-6-t-butylphenylacrylate and trisnonylphenylphosphite were added to 100 parts by weight of the block copolymer, respectively. It was obtained by adding 0.5 part by weight as a stabilizer and distilling off the solvent. The block polystyrene content (% by weight) was measured by decomposing the block copolymer with osmic acid and then reprecipitating it in methanol. The melt flow (MI) was measured under G condition.

[0032]

[Table 1] (Note) A is a polybutadiene block, B is a copolymer block of butadiene and styrene, and C is a polybutadiene block. X is used as a coupling agent 1,
It is a residue of 3-bis (N, N-glycidylaminomethyl) cyclohexane. C of A-6 is 3% by weight, Al / A
2 is 1/3 (weight ratio). Al / A2 other than A-6
Is 1/1 (weight ratio).

(B) Component rubber-modified polystyrene Table 2 shows the (b) component rubber-modified polystyrene used in Examples and Comparative Examples. B-5 and 6 are rubber-modified polystyrene obtained by bulk polymerization of styrene in which polybutadiene rubber is dissolved. The other rubber-modified polystyrenes other than B-5 and 6 are rubber-modified polystyrene obtained by bulk polymerization of styrene in which polybutadiene or styrene-butadiene rubber is dissolved, and then dissolved in styrene again to give 1,1- Bis (t-butylperoxy) 3,3,5
-Trimethylcyclohexane (600 ppm) and t-dodecyl mercaptan (600 ppm) were added, and this solution was heated at 120 ° C for 2 hours with stirring to increase the polystyrene graft amount of the dispersed particles, which is a rubber-modified polystyrene. The amount of dispersed particles of the rubber-modified polystyrene is the weight% obtained by dissolving the rubber-modified polystyrene in toluene or MEK, filtering the dispersed particles with a centrifuge, and drying. The polystyrene content of the dispersed particles was determined by measuring pyrolysis gas chromatography of the dispersed particles to determine the polystyrene content. The measurement conditions were such that the column filler was APIZONE GREASE L, the decomposition temperature was 600 ° C., the injection temperature was 250 ° C., and the column temperature was 140 ° C.

[0034]

[Table 2]

(Examples 1 to 7 and Comparative Examples 1 to 7) An extruder was used in which the block copolymer of the component (a) and the rubber-modified polystyrene of the component (b) shown in Table 3 were blended (wt%). After pelletizing using, the molded piece with a thickness of 3 mm was prepared using an injection molding machine and the physical properties were measured. The results are shown in Table 3.
The block copolymer, the rubber-modified polystyrene, and the compounding amount within the ranges specified in the present invention are pencil hardness (in accordance with JIS K5400), which is a measure of surface hardness, and flexural elastic modulus (in accordance with ASTM D790), which represents rigidity. It can be seen that the balance of the dart impact value (according to ASTM D1709) showing the impact resistance is excellent. As for transparency, a haze value (according to JIS K6714) was low, and a transparent and beautiful molded product was obtained.

[0036]

[Table 3]

(Examples 8 to 10 and Comparative Example 8) The block copolymers of the component (a) shown in Table 4 and the rubber-modified polystyrene and polystyrene of the component (b) [Asahi Kasei Polystyrene manufactured by Asahi Kasei Co., Ltd.] 685] is formed into a sheet having a thickness of about 0.7 mm with a 40 mm sheet extruder, and the tensile elastic modulus (according to JIS K-6872: unit is Kgf / c).
m ² ), surface impact strength (conforms to ASTM D1709 except that the weight shape is ½ inch): Unit is Kgf · c
m) and haze value (according to JIS K6714: unit is%). It can be seen that the sheet molded product within the range defined by the present invention is transparent and has excellent rigidity and surface impact resistance.

[0038]

[Table 4]

[0039]

As described above, by using the composition of the block copolymer and the rubber-modified polystyrene having dispersed particles having a specific structure, a molded article excellent in surface impact resistance, rigidity and transparency is provided. To do.

Claims (4)

[Claims] 1. A composition comprising (a) a polymer block containing at least two vinyl aromatic hydrocarbons as a main component and at least one polymer block containing a conjugated diene as a main component, and having a vinyl aromatic hydrocarbon content. 70 to 99.5% by weight of a block copolymer, which is 65 to 90% by weight, and (b) a rubber-modified polystyrene obtained by graft-polymerizing styrene to a butadiene rubber-like polymer, wherein the inside of dispersed particles thereof 0.5 to 30% by weight of the rubber-modified polystyrene, in which polystyrene is included in the rubber composition, the average particle diameter of the dispersed particles is 0.5 to 10 μm, and the polystyrene content of the dispersed particles is 75% to 90% by weight. An impact-resistant transparent resin composition comprising: 2. The impact-resistant transparent resin composition according to claim 1, wherein the content of polystyrene in the dispersed particles of (b) is more than 80% by weight and 90% by weight or less. 3. An impact-resistant transparent resin composition comprising 100 parts by weight of the impact-resistant transparent resin composition according to claim 1 and 1 to 150 parts by weight of a styrene-based polymer. 4. The impact-resistant transparent resin composition according to claim 3, wherein the styrene-based polymer is a non-rubber-modified styrene-based polymer.