JPS6131459A - Resin composition having improved stress cracking property and impact resistance - Google Patents

Abstract

PURPOSE:The titled composition having improved impace resistane and oil resistance, by blending polyphenylene ether resin with a hydrogenated derivative of a specific elastomer block copolymer and a specified block copolymer. CONSTITUTION:(A) 20-90pts.wt. polyphenylene ether resin is blended with (B) >=0.5pt.wt. hydrogenated derivative of A1-B-A2 type elastomer block copolymer (A1 and A2 are vinyl aromatic hydrocarbon block; B is conjugated diene block, molecular weight of B is larger than molecular weight of combined A1 and A2), (C) >=0.5pt.wt. block copolymer comprising two or more elastomeric blocks and two or more non-elastomeric blocks, wherein preferably at least one end is elastomeric block, and a weight ratio of vinyl aromatic hydrocarbon to conjugated diene is 10:90-55:45, and (D) 0-80pts.wt. styrenic resin preferably rubber-reinforced styrenic resin having impact resistance in such a way that total amounts are 100pts.wt. and the total of the components B and C are <=40pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermoplastic resin composition having excellent impact resistance and oil resistance. More specifically, (a) polyphenylene ether m resin, (b) hydrogenated derivative of A1-B-A2 type elastomeric block copolymer, and (c) composition ratio of elastomeric block and non-elastomeric block were specified. The present invention relates to a resin composition containing a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene, and (d) a styrene resin.

[Conventional technology]

Polyphenylene ether is a resin that has attracted much attention in recent years because of its excellent mechanical properties, electrical properties, and heat resistance, as well as its low water absorption and good dimensional stability. However, since polyphenylene ether resin alone generally has poor processability and impact strength, in many industrial applications it is used as a blend with polystyrene or rubber-reinforced polystyrene.

On the other hand, it is also a trend in recent years that the shapes of industrial parts and electrical parts are becoming more complex, and the properties of resins are also becoming more and more demanding.
Especially in terms of impact resistance and oil resistance, the resins mentioned above are no longer able to adequately meet these uses.

In order to meet these demands, several attempts have been made to improve impact resistance. For example, JP-A-48-628
No. 51, JP-A-51-129450, and JP-A-52-125560 disclose polyphenylene ether resins containing linear block copolymers and radial block copolymers of vinyl aromatic hydrocarbons and conjugated dienes. Compositions incorporating polymers are presented.

That is, JP-A-48-62851 and JP-A-51-
1.29450 discloses (a) a polyphenylene ether resin, (b) an A''-ba2 type elastomer block copolymer of vinyl aromatic compounds AI and A2 and conjugated diene B, and (c) as an optional component. A thermoplastic resin composition comprising a styrene homopolymer or random copolymer resin is described. Also, JP-A-52-125560 discloses (a) a polyphenylene ether resin, (b) a styrene resin, and (c ) Thermoplastic molding compositions are described which consist of a homogeneous mixture of a radial teleblock copolymer consisting of a vinyl aromatic compound, a conjugated diene, and a coupling agent.

Furthermore, JP-A-53-79943 discloses (a) polyphenylene ether resin, (b) styrene resin, (c)
Thermoplastic compositions consisting of elastomeric block copolymers of the AB-Al type and hydrogenated derivatives of (d) and (c) are described.

However, although the compositions obtained by carrying out these suggestions have a certain degree of impact resistance improvement effect, they are not fully satisfactory depending on the intended use. In order to achieve a sufficiently high degree of impact resistance using the methods presented above, it is necessary to increase the amount of the block copolymer described in these methods, and in such cases, stiffness and heat resistance This is extremely undesirable from a practical point of view, as it causes problems such as a decrease in performance.

Furthermore, it has been found in the process of achieving the present invention that the stress cracking properties of the composition obtained by carrying out the method presented above are slightly improved, but not enough to solve the practical problem. isn't it.

[Problem that the invention seeks to solve]

The present invention has been made in order to obtain a polyphenylene ether resin composition having good impact resistance and stress cracking properties without deteriorating the excellent performance of the polyphenylene ether resin.

The present invention comprises (i) a hydrogenated product of an A1-B-A2 type elastomeric block copolymer, (11) a vinyl aromatic hydrocarbon and a conjugated diene in which the composition ratio of elastomeric blocks and non-elastomeric blocks is specified. This was based on the discovery that a significant improvement effect could be obtained by using a block copolymer with

[Means and effects for solving the problems] According to the present invention, (a) 20 to 90 parts by weight of polyphenylene ether resin (b) A, -B-A2 type elastomer block copolymer (however, Ao and AQ are 0.5 parts by weight of a hydrogenated derivative of a polymerized vinyl aromatic hydrocarbon block, B is a polymerized conjugated diene block, and the molecular weight of B is greater than the combined molecular weight of AI and A2. (c) consisting of at least two elastomeric blocks and at least two non-elastomeric blocks, and the weight ratio of vinyl aromatic hydrocarbon to conjugated diene is 1;
Block copolymer of vinyl aromatic hydrocarbon and conjugated diene with a ratio of 0:90 to 55:45: 05 parts by weight or more (a) Styrenic resin Used in the range of 0 to 80 parts by weight, making the total 100 parts by weight A resin composition formulated as follows fh7 provides a resin composition in which the total of component (b) and component (c) does not exceed 40 parts by weight.

The polyphenylene ether resin referred to in the present invention is [■]
Or, in the general formula of [■], [I] [old (R1+ RQ + R3+ R4+ R5 and R6 are the same or different alkyl groups with 1 to 4 carbon atoms excluding tert-butyl groups, aryl groups, R5 and R6 are not hydrogen atoms at the same time)
A polymer or copolymer having the repeating unit shown above is produced by, for example, reacting raw material phenol with oxygen in the presence of a complex of copper and manganese, although the manufacturing method is not particularly limited.

Specific examples of polyphenylene ether resins that can be used in the present invention include poly(2,6-dimethyl-1°4-phenylene) ether, pho! J (2,6-dichloro-1,4-phenylene) ether, poly(2,6-dichloro-1,4-phenylene) ether, poly(2゜6-dipromo-1,4-phenylene) Ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2-chloro-6-methyl-1,4-phenylene) ether, poly(2-methyl-6-isopropyl-1) ,4
-phenylene) ether, poly(2,6-di-n-propyl-1,4-phenylene) ether, poly(2-1
0-6-bromo-1,4-phenylene) ether, poly(2-chloro-6-ethyl-1,4-phenylene) ether, poly(2-chloro-6-ethyl-1,4-
phenylene) ether, poly(2-methyl-1,4-phenylene) ether, poly(2-phenyl-1,4-phenylene) ether, PoIJ (2-methyl-6-phenyl-1,4-phenylene) ether , poly(2-bromo-6-phenyl-], ]4-phenylene ether, and polyphenylene obtained by copolymerizing an alkyl-substituted phenol such as 2.2.3.6- )limethylphenol with, for example, O-cresol. Examples include polyphenylene ether copolymers mainly having an ether structure. Furthermore, these may be grafted with a monomer mainly composed of styrene.

The PoIJ phenylene ether resin is used in a range of 20 to 90 parts by weight. If the amount is less than 20 parts by weight, the good heat resistance that polyphenylene ether materials originally have will be impaired. Moreover, if it exceeds 90 parts by weight, the molding processability will be greatly reduced, making it undesirable as a molding material.

The hydrogenated product of the A, -B-A2 type elastomer block copolymer that can be used in the present invention is the A1-B-12 type in which the center and end blocks are changed. In the compositions of the present invention, the central block B is derived from a conjugated diene such as butadiene, imprene, 1,3-pentadiene, 2,3-dimethylbutadiene, etc., and the terminal blocks A and A2 are vinyl aromatic Compounds such as styrene, α
- Obtained by hydrogenation of copolymers derived from methylstyrene, vinyltoluene, vinylnaphthalene, etc., in particular copolymers of said blocks in which the average unsaturation of the central block B has been reduced to below 20% of its original value. Polymers in which the molecular weight of B is greater than the combined molecular weight of A1 and A2 can be used; 20,000 to about 450,000
It is preferred to form a central block B having an average molecular weight of up to .

Such block copolymers are prepared by adding hydrogenation catalysts such as nickel, Raney nickel, copper chromate, etc. to the block copolymers obtained by organometallic initiation, for example using sodium or lithium metals or their organic derivatives. Hydrogenation can be carried out using molybdenum sulfide, fine platinum powder, etc. The preparation of hydrogenated block copolymers is described in detail in US Pat. No. 3,431,323.

The second block copolymer used in the present invention consists of at least two elastomeric blocks and at least two non-elastomeric blocks, and has a weight ratio of vinyl aromatic hydrocarbon to conjugated diene of 10; 90 to 55. :45 is a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene.

This second block copolymer is composed of at least two elastomeric blocks and at least two non-elastomeric blocks, at least one terminal block is an elastomeric block, and a vinyl aromatic hydrocarbon and a conjugated diene A block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene having a weight ratio of 10:90 to 55:45 is particularly preferred for achieving the object of the present invention. If the second block copolymer does not meet the above requirements,
In the final composition, the desired improvement effect is weak.

In the present invention, an elastomeric block is defined as having a vinyl aromatic hydrocarbon content of 75% by weight or less, preferably 5% by weight.
A copolymer block of a vinyl aromatic hydrocarbon and a conjugated diene/and/or a conjugated diene homopolymer block with a vinyl aromatic hydrocarbon content of 0 weight% or less, and a non-elastomer block is a block with a vinyl aromatic hydrocarbon content of 75% by weight. more than 8, preferably 8
It is a copolymer block of 5% by weight or more of a vinyl aromatic hydrocarbon and a conjugated diene, or/and a vinyl aromatic hydrocarbon homopolymer block. The vinyl aromatic hydrocarbon in the copolymer block of vinyl aromatic hydrocarbon and conjugated diene may be uniformly distributed in the block or may be distributed in a tapered shape.

The number average molecular weight of the second block copolymer used in the present invention is generally 10,000 to 1.000.000, preferably 20. OO6~500. It's OOO.

The polymer structure of the second block copolymer used in the present invention can be exemplified by the following general formula.

(B) Es A1'Bq -('A-B→-A2 (B) B+ -At B2 -(-A -, gu-A9~ B1 (C) [El-A1-'B2-(4-B
4x) C", A, I BQ+A-B blind At] 3(
In the above formula, B + B1, BQ + B8 are elastomeric blocks, A + A1 * AQ are non-elastomeric blocks, X is silicon tetrachloride, tin tetrachloride,
Indicates the residue of a coupling agent such as epoxidized soybean oil or polyester ester, or the residue of an initiator such as a polyfunctional organolithium compound. m and n are integers of 0 or 1 or more.

Generally it is O or an integer from 1 to 5. ) In the above general formula, A, A□lAl1 or B.

Bs + B9 and Ba may have the same or different molecular weight composition, microstructure, etc., respectively.

The second block copolymer is obtained by sequentially polymerizing a monomer for forming an elastomeric block and a hexamer for forming a non-elastomeric block in a hydrocarbon solvent using an organic lithium compound as a catalyst. It can be manufactured by

Vinyl aromatic hydrocarbons used in the production of the block copolymer used in the present invention include styrene, 0-methylstyrene, p-methylstyrene, p-tert-f
f/l/styrene, ■, 3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene, etc., and styrene is particularly common. These may be used not only as a single type but also as a mixture of two or more types. Further, the conjugated diene is a diolefin having a conjugated double bond having 4 to 801 carbon atoms, such as 1,3 butadiene, 2-methyl 1,3-butadiene (isoprene), 2,3-dimethyl Examples include 1,3 butadiene, 1,3-hentadiene, 1,3-hexadiene, etc., but 1,3-hexadiene is particularly common.
Examples include butadiene and isoprene. These may be used not only as a single type but also as a mixture of two or more types.

The second block copolymer used in the present invention may be blended into the thermoplastic resin after undergoing modification treatments such as halogenation, sulfonation, hydroxylation, epoxidation, and maleation, if necessary. It is possible.

In the present invention, it is essential to use the two types of block copolymers described above together. The ratio of the two types of block copolymers used is not particularly limited, but is usually 1:3 to 3:1.
used in

The total amount of the two types of block copolymers is 40 parts by weight or less based on 100 parts by weight of the total composition. If it exceeds 40 parts by weight, properties such as rigidity and good heat resistance that polyphenylene ether materials originally have will be impaired, which is not preferable.

The styrenic resin that can be used in the present invention has specific examples (in the formula,
R represents hydrogen, lower alkyl or halogen, 2 is selected from the group consisting of vinyl, hydrogen, chlorine and lower alkyl, and p is an integer from O to 5. It has at least 25% by weight. As used herein, the term "styrenic resin" is defined by the formula above and includes, by way of example, homopolymers such as polystyrene and polychlorostyrene,
Modified polystyrenes, such as rubber-modified polystyrenes, as well as styrene-containing copolymers, such as styrene-acrylonitrile copolymers (SAN), styrene-butadiene copolymers, styrene-acrylonitrile-butadiene copolymers (ABS), polyα-methylstyrene, ethylvinylbenzene and divinylbenzene copolymer of,
Styrene and α.

Copolymers of β-unsaturated dicarboxylic acid anhydrides, copolymers of imidized styrene and α, β-unsaturated dicarboxylic acids, and the like are included.

Styrenic resin components suitable for the present invention are rubber-modified impact styrenic resins, such as polystyrene modified with natural or synthetic rubber. Modified synthetic rubbers include, for example, polybutadiene, polyisoprene, dienes and other comonomers,
Rubbery copolymers of styrene, acrylonitrile, acrylic esters, etc., including block copolymers of the A-B-A and A-B type (A is a vinyl aromatic, e.g. styrene, B is a diene, e.g. butadiene) and ethylene -Glopyrene dienterpolymer- (
EPDM) rubber, etc.

The styrene resin is used in an amount of 80 parts by weight or less. 80
If the amount exceeds 1 part by weight, the heat resistance of the final composition decreases, which is undesirable.

Depending on the purpose, the composition of the present invention may be added with conventionally known additives, such as Al(OH)a, phosphoric acid esters, melamine flame retardants, rogen flame retardants, red phosphorus, and other flame retardants; Polybutene, low molecular weight polyethylene, mineral oil, epoxidized soybean oil, polyethylene glycol, plasticizers such as fatty acid esters, phosphorous esters, hindered phenols, alkanolamines, acid amides, dithiocarbamate metal salts, inorganic One or more stabilizers such as sulfides and metal oxides, various ultraviolet absorbers, colorants, mold release agents, etc. can be added.

Furthermore, the composition of the present invention may contain reinforcing fillers such as glass fibers, carbon fibers, various metal fibers, various metal flators, asbestos, wollastonite, calcium carbonate, Merck, mica, zinc oxide, potassium titanate, titanium oxide, etc. , glass peas, etc., it is possible to obtain a filler-containing resin composition having even higher rigidity and heat resistance.

If a conductive filler such as carbon fiber is selected as the filler, functions such as conductivity and electromagnetic shielding properties can be imparted.
The composition of the present invention is no exception.

The composition of the present invention can be obtained using an extruder, a kneader, etc.
, a roll mixer, a Banbury mixer, or the like is used. In the case of melt mixing, all the components may be mixed at the same time, or some components may be mixed in advance, and then the remaining components may be added and mixed.

The resin composition of the present invention thus obtained can be processed into sheets, foams, films, injection molded products of various shapes, hollow moldings, etc. by any conventionally known molding method, such as extrusion molding, injection molding, and blow molding. It can be easily molded into a wide variety of practically useful products such as molded products, pressure-formed products, and vacuum-formed products.

The present invention will be explained below with reference to Examples, but the present invention is not limited to the following Examples.

In the examples, parts indicate parts by weight. In addition, physical property values were measured by the following method.

Heat resistance: JIS-
The heat distortion temperature (hereinafter abbreviated as H, I, T) was measured at a load of 18.6 kg/cIn2 according to K7207.

Impact strength): Notched isot impact strength was measured using injection molded test pieces having a thickness of 1/4 according to A, STM-D~638 (measurement temperature: 23°C).

Impact strength 2): Using a test piece with a thickness of 31 nm, DuPont type darting was performed using a 1/16"R missile.

○Evaluation rank ◎: 75kg-υ or more ○: 55kg-cm or more, less than 75kg-m △: 35k
G - Brass or more, 55 to 9 - Less than Fu
, a test piece sample with a length of 120 mm is prepared. This test piece is annealed in a hot air dryer at 80° C. for 24 hours to remove residual strain. Next, one end of this test piece was held in a creep rupture measuring machine made by Seiwa Riko, and the other end was
After setting the load, apply 02 g of shaft grease D (manufactured by Sato Special Oil Co., Ltd.) at a position 20 mm from the load setting side, and then keep it in a constant temperature room at 23° C. and 50% humidity to measure the time until breakage. The longer the time until breakage, the better the stress cracking property.

○Evaluation rank ○: 100 hours or more △: 50 hours or more and less than 100 hours
In addition to those shown in Table 2, the following were used.

Polyphenylene ether: ηsp/c = 0.60
(5% solution in chloroform) of poly(2,6-dimethylphenylene-1,4-ether). (Hereinafter abbreviated as pPE) Styron QH405: Manufactured by Asahi Kasei Industries, Ltd. I Impact Polystyrene Styron 685: Polystyrene Dylark+ manufactured by Asahi Kasei Industries, Ltd. 232: Styrene-maleic anhydride copolymer manufactured by AROO Polymers (hereinafter referred to as pPE) (abbreviated as SMA) Styrene-N-phenylmaleimide copolymer: A prototype polymer with a N-phenyl-maleimide content of 10% was used (hereinafter abbreviated as SPMI) Clayton G] 651 A manufactured by Nijinil Chemical Co., Ltd. -B-4
Type 2 hydrogenated styrene-butadiene block copolymer (
Styrene content 33%, polymer concentration 20wt%, toluene solution viscosity 2000 cps (25°C)) Kraton G1.652: Same as above (styrene content 29%,
Polymer concentration 20wt%, toluene solution viscosity 550c
ps (25°G)) Califlex TR20I manufactured by Nisiel Chemical Co., Ltd., non-hydrogenated A, -B-A2 type styrene-butadiene block copolymer (styrene content 30%, polymer concentration 2
5wt, % toluene solution viscosity 4000 cps (25
°C)) [Manufacture of block copolymer] Polymerize the monomers of part B1 at about 70 °C in a cyclohexane solvent under a nitrogen atmosphere using n-butyllithium as a catalyst according to the monomer amounts shown in Table 1. After the monomer was substantially completely polymerized, 1 part of the monomer was added and polymerized. After the added monomers have substantially completely polymerized, B2, A2. BB
A linear block copolymer was obtained by sequentially polymerizing parts. On the other hand, the radial type block copolymer was prepared using B11A in the same manner as above according to the monomer amounts shown in Table 2.
After sequentially polymerizing 1°B9 and A9, silicon tetrachloride was added in an amount of 4 moles per part to n-butyllithium used in the polymerization, and a coupling reaction was carried out. In addition, in Tables 1 and 2, the amount of monomer charged is 0.
A step means that the polymerization of that step was omitted. Moreover, block polymer 6 means that the parts in parentheses were added at the same time. Further, when a mixed monomer of butadiene and styrene was used in forming the elastomeric block (Block Polymer 8), 1 part by weight of tetrahydrofuran was used as a randomizing agent per 100 parts by weight of the total fecal monomer.

Each block copolymer obtained contains 2,4 as a stabilizer.
-D-tert-butyl-p-cresol, trisnonylphenyl phosphite and phenothiazine were each added in an amount of 05 parts by weight per 100 parts by weight of the block copolymer.

In Tables 1 and 2, Bd represents butadiene, St represents styrene, and Is represents isoprene.

Table 2 Examples 1 to 6 and Comparative Examples 1 to 2 50 parts of PPE, 35 parts of Stylon 685, 5 parts of Kraton 01651, 10 parts of the block copolymer shown in Tables 1 and 2, Irganox 1076 as a stabilizer
(manufactured by Ciba-Geigy) was mixed in a blender, and then mixed at a maximum cylinder temperature of 2 using a twin-screw extruder.
A pellet was obtained by extrusion at 90°C, and a test piece was prepared using an injection molding machine at 290°C and used for testing.

The results are shown in Table 3, and it can be seen that the thermoplastic resin composition blended with the block copolymer defined by the present invention has excellent grain impact resistance and stress cracking resistance.

Comparative Example 3 In Example 1, the block copolymers shown in Tables 1 and 2 were replaced with Cariflex'I'RIIOI, and the test was conducted in exactly the same manner as in Example 1.

The results are shown in Table 3. It can be seen that the stress cracking properties are not sufficiently good.

Comparative Example 4 In Comparative Example 3, a test was performed in the same manner as in Example 1 except that Kraton G 651 was replaced with Kraton G1652. The results are shown in Table 3. Comparative example 3 and I
n, it can be seen that the stress cracking properties are not sufficiently good.

Comparative Example 5 In Example 1, a test was conducted in the same manner as in Example 1 except that Kraton G1651 was not used and 15 parts of Block Polymer 1 in Table 1 was used. The results are shown in Table 3. It can be seen that the stress cracking properties are not sufficiently good.

Comparative Example 6 In Example 1, a test was conducted in the same manner as in Example 1 except that Block Polymer 1 in Table 1 was not used and 15 parts of Kraton G1651 was used. The results are shown in Table 3. It can be seen that the impact strength and stress crack resistance are not sufficiently good.

Examples 7 to 9 and Comparative Examples 7 to 9 Each component was blended in the numbers shown in Table 4, and tested in the same manner as in Example 1.

The results are shown in Table 5. It can be seen that the thermoplastic resin composition having the blending ratio specified in the present invention has heat resistance, which is a characteristic of polyphenylene ether-based materials, and is excellent in impact resistance and stress cracking resistance.

On the other hand, it can be seen that when the blending ratio is outside the scope of the present invention, a decrease in rigidity, a decrease in heat resistance, etc. occur, and the excellent properties originally possessed by polyphenylene ether-based materials are lost.

Example 10 PPE 40 parts, SM1, 10 parts, Styron 685 2
A composition containing 0 parts, 525 parts of QH40, 3 parts of Kraton 01651, 12 parts of the block polymer shown in Table 1, and 0.2 parts of Irganox 1076 was prepared by the method of Example 1 and subjected to testing. The results are shown in Table 6. It can be seen that a composition that meets the objectives of the present invention was obtained.

Example 11 In Example 1, 68535 parts of Stylon was replaced with 20 parts of Stylon 685' and 15 parts of SPML,
The test was carried out in the same manner as in Example 1. The results are shown in Table 6. It can be seen that a composition meeting the purpose of the present invention was obtained.

Example 12 In Example 1, the PPE was ηsp//IC-065(
Exactly the same composition and conditions except that chloroform (5% solution) was replaced with a copolymer of 2,6-dimethylphenol (90 mol%) and 2.3.6-)limethylphenol (10 mol%). The evaluation was carried out. The results are shown in Table 6. It can be seen that a composition that meets the objectives of the present invention was obtained.

Table 4 Table 5 Table 6 [Effects of the Invention] As described above, the present invention reduces the excellent performance such as rigidity and heat resistance originally possessed by polyphenylene ether resin. It is possible to improve the impact resistance and stress cracking property without causing any damage, and it dramatically expands the field of application of polyphenylene ether resins, and has great industrial significance.

Claims (1)

[Scope of Claims] [1] (a) 20 to 90 parts by weight of polyphenylene ether resin (b) A_1-B-A_2 type elastomer block copolymer (A_1 and A_2 are polymerized vinyl aromatic hydrocarbon blocks) and B is a polymerized conjugated diene block, and the molecular weight of B is greater than the combined molecular weight of A_1 and A_2) (c) at least two elastomers. block and at least two non-elastomeric blocks, the weight ratio of vinyl aromatic hydrocarbon to conjugated diene is 10:90.
0.5 parts by weight or more of a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene with a ratio of ~55:45 (d) Styrenic resin Used in the range of 0 to 80 parts by weight, so that the total amount is 100 parts by weight. A resin composition in which the total of component (b) and component (c) does not exceed 40 parts by weight. [2] Consisting of at least two elastomeric blocks and at least two non-elastomeric blocks, the weight ratio of vinyl aromatic hydrocarbon to conjugated diene is 10:90
~55:45 block copolymer of vinyl aromatic hydrocarbon and conjugated diene consisting of at least two elastomeric blocks and at least two non-elastomeric blocks, with at least one end being an elastomeric block. The resin composition according to item 1, which is a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene, and the weight ratio of the vinyl aromatic hydrocarbon to the conjugated diene is from 10:90 to 55:45. thing. [3] Polyphenylene ether resin has the formula [I] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [II] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_1, R_2, R_3, R_4, R_5, R
_6 is the same or different alkyl group having 1 to 4 carbon atoms excluding tert-butyl group, aryl group, halogen, monovalent residue such as hydrogen, R_5 and R_6 are not hydrogen at the same time) as a repeating unit, The constituent unit is [I] or [I
] and [II], which is a homopolymer or a copolymer. [4] Polyphenylene ether resin is poly(2,6-
The composition according to claim 1, which is dimethyl-1,4-phenylene) ether. [5] The composition according to claim 1, wherein the polyphenylene ether resin is a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol. [6] The styrenic resin is polystyrene, a copolymer of styrene and α,β-unsaturated dicarboxylic acid anhydride containing at least 25% by weight of styrene, and a copolymer of styrene and α,β-unsaturated dicarboxylic acid anhydride containing at least 25% by weight of styrene. The composition according to claim 1, which is one or more copolymers of imidized unsaturated dicarboxylic acids. [7] The composition according to claim 1, wherein the styrenic resin is polystyrene. [8] The composition according to claim 1, wherein the styrenic resin is rubber-modified high-impact polystyrene.