JPH11293042A - Thermoplastic elastormer composition for automotive molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition that reduces a restoring force on bending of an automotive molding and that has a low specific gravity and remarkably excellent flexibility and molding processability. SOLUTION: A thermoplastic elastomer composition comprises (a) 100 pts.wt. block copolymer comprising at least two polymer blocks A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound and/or a hydrogenated block copolymer obtained by hydrogenating the block copolymer (wherein the polymer block B contains a polyisoprene block in which 20-80% of the isoprenes have 1,4-bonds and 80-20% thereof have 3, 4-bonds; or at least 80% of double bonds derived from isoprenes in the block copolymer are hydrogenated.), (b) 10-130 pts.wt. vinyl aromatic resin, (c) 15-300 pts.wt. non-aromatic softening agent for a rubber, (d) 0.1-3 pts.wt. organic peroxide and (e) 0.1-10 pts.wt. crosslinking auxiliary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to various moldings such as wind molding, roof molding, protector molding and weatherstrip molding which are mounted on an automobile, and the various moldings have gentle bending restoring force, low specific gravity and flexibility. sex,
The present invention relates to a thermoplastic elastomer composition having excellent moldability.

[0002]

2. Description of the Related Art In recent years, the body of automobiles has adopted a streamlined shape with the advancement of the technology. In the case of a long object such as a molding, it is often extruded. In many cases, a molded article is bent and mounted on an automobile. For this reason, polyvinyl chloride, which has a small bending restoring force and good moldability, is widely used as a molding material. However, in view of weight reduction and environmental measures, olefin resins and styrene resins have been used instead of polyvinyl chloride, which has good moldability, but it has been extruded due to its large bending recovery. It has been very difficult to bend a long product after processing and mount it on an automobile. In addition, since styrene resins have poor oil resistance, there is a problem that their use is limited in fields requiring oil resistance and heat resistance, such as automotive applications such as molding.

[0003]

DISCLOSURE OF THE INVENTION The present invention uses a thermoplastic elastomer composition which has a gentle bending restoring force, is gentle, has excellent light weight, flexibility, oil resistance, moldability, and vibration damping properties, for use in molding of automobiles. The purpose of the present invention is to solve the conventional problem.

[0004]

As a result of studying the present invention, it has been found that styrene / conjugated diene-based block copolymers and / or hydrogenated block copolymers have vinyl aromatic resins and non-aromatic rubbers. Crosslinking with an organic peroxide together with a softener for softness, gentle bending restoring force, light weight, rich in flexibility, excellent in oil resistance, molding workability, vibration damping properties, effective thermoplastic for various moldings for automobiles It has been found that an elastomer composition is obtained. In particular, the present invention is effective in various moldings such as wind molding, roof molding, protector molding, and weatherstrip molding that are mounted on an automobile. That is, the present invention provides a thermoplastic elastomer resin composition used in various moldings for automobiles, which has a gentle bending restoring force, a small specific gravity, and excellent flexibility and moldability. Secondly, the present invention is characterized in that the thermoplastic elastomer resin composition comprises: (a) at least two polymer blocks A mainly made of a vinyl aromatic compound and at least one polymer block B mainly made of a conjugated diene compound And / or 100 parts by weight of a hydrogenated block copolymer obtained by hydrogenating the block copolymer. (However, the polymer block B contains a polyisoprene block, and isoprene is a block copolymer in which 20 to 80% by weight has 1,4-bonds and 80 to 20% by weight has 3.4-bonds.) Or at least 80 of aliphatic double bonds derived from isoprene of the block copolymer.
% Hydrogenated block copolymer) (b) Vinyl aromatic resin 10 to 130 parts by weight (c) Softener for non-aromatic rubber 15 to 300 parts by weight (d) Organic part Oxide 0.1 to 3 parts by weight (e) Crosslinking aid 0.1 to 10 parts by weight.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Each component in the composition of the present invention will be described. Component (a): Essential component The block co-assembly and the hydrogenated block copolymer are mainly made of a vinyl aromatic compound (hereinafter, sometimes referred to as a vinyl aromatic compound as a main component). A block copolymer obtained by hydrogenating a block copolymer consisting of a block A and at least one polymer block B mainly made of a conjugated diene compound (hereinafter sometimes referred to mainly as a conjugated diene compound). The block copolymer and the hydrogenated block copolymer contain a vinyl aromatic compound as a whole in an amount of 5 to 60% by weight, preferably 20 to 50% by weight. 50% by weight or more, preferably 70% by weight or more of a vinyl aromatic compound and an optional component such as a conjugated diene compound. The is a homopolymer or copolymer block. The polymer block B mainly composed of a conjugated diene compound contains 50% by weight or more, preferably 70% by weight or more of a conjugated diene compound and optional components,
For example, homopolymers or polymer blocks made from vinyl aromatic compounds. As the vinyl aromatic compound constituting the block copolymer and the hydrogenated block copolymer,
For example, one or more of styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, and the like can be selected, and among them, styrene is preferable. Also,
Examples of the conjugated diene compound include butadiene, isoprene, 1.3-pentadiene, 2.3-dimethyl-1.
One or more selected from 3-butadiene and the like,
Among them, butadiene, isoprene and a combination thereof are preferred. In the polymer block B mainly composed of a conjugated diene compound, its microstructure can be arbitrarily selected. The polymer block B mainly composed of a conjugated diene compound contains a polyisophrene block, and isoprene has a weight of 20 to 80% by weight. 9% is a 1,4-bond and its 80-
Hydrogenated block copolymer in which at least 80% of the block copolymer or 20% by weight of the aliphatic double bond derived from isoprene is hydrogenated having 3.4 bonds; It consists of coalescence.
The above is, for example, the number average molecular weight of the block copolymer and the hydrogenated block copolymer which are commercially available from Kuraray Co., Ltd. as Hibler VS and Hybler HVS, are preferably 5,000 to 1,000,000,
More preferably, it is in the range of 10,000 to 500,000, even more preferably 100,000 to 300,000, and the molecular weight distribution is 10 or less. Component (b): Essential component Examples of the vinyl aromatic resin include polystyrene, rubber-modified polystyrene (impact polystyrene), and styrene-α.
-Methyl styrene copolymer, styrene-paramethyl styrene copolymer, styrene-atalylic rubber-acrylonitrile copolymer, styrene-maleic anhydride copolymer, and the like, and one or more of these. Can be selected. The rubber component of rubber-modified polystyrene is 2 to
It contains 15%. Among them, polystyrene is preferable. Further, the melt flow rate is 0.5 to 60 g / 1.
It is preferably 0 minutes (measured at 200 ° C under a load of 5.0 kg). Further, those having a weight average molecular weight of 10 ³ to 10 ⁷ are preferred. When component (b) is used, component (a) 1
The lower limit is 10 parts by weight or more, preferably 20 parts by weight or more, more preferably 50 parts by weight or more based on 00 parts by weight. The upper limit is used in an amount of 130 parts by weight or less, preferably 80 parts by weight or less. If the amount is less than 10 parts by weight, the moldability will be poor. On the other hand, if it exceeds 130 parts by weight, the hardness of the obtained elastomer composition becomes too high, and the flexibility is lost. Component (c): Essential Component The non-aromatic rubber softener is a non-aromatic mineral oil or a liquid or low molecular weight synthetic softener. A mineral oil softener generally used for rubber is a mixture of an aromatic ring, a naphthene ring and a paraffin chain in which the number of carbon atoms is 50% or more of the total number of carbon atoms. System, naphthene ring carbon number is 30 ~
Those with 40% are called naphthenics, and those with 30% or more of aromatic carbons are called aromatics. The mineral oil-based rubber softener used as the component (c) of the present invention includes:
Paraffinic and naphthenic in the above category,
Aromatic softeners are not preferred in terms of dispersibility with component (a). In particular, component (c) of the present invention is preferably a paraffinic one. Those with little are particularly suitable. Component (c)
Is at least 15 parts by weight, preferably at least 30 parts by weight, and at most 300 parts by weight, preferably at most 150 parts by weight, per 100 parts by weight of component (a). If the amount is more than 300 parts by weight, the softener tends to bleed out, which may give tackiness to the final product, and also deteriorates the mechanical properties. In addition, the blending of less than 15 parts by weight is
Moldability becomes difficult, and the flexibility of the resulting composition is lost. Component (d): Essential Component Examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, and 2,5.
-Dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di (ter
t-butylperoxy) hexyne-3, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, 1.3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (Tert-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-
Chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butylcumyl peroxide, and the like, These may be used alone or in combination of two or more. Among them, 2,5-dimethyl-2,2 is preferred in terms of odor, coloring, and scorch stability.
5-di- (tert-butylperoxy) hexane,
2,5-Dimethyl-2,5-di (tret-butylperoxy) hexyne-3 is most preferred. The amount of component (d) is 0.1 to 3 parts by weight based on 100 parts by weight of component (a). Component (e): Indispensable component As a crosslinking aid, divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate Such a polyfunctional methacrylate monomer, a polyfunctional vinyl monomer such as vinylidide or vinyl stearate can be blended as a crosslinking aid. With such a compound, a uniform and efficient crosslinking reaction can be expected. Component (e) is compounded in an amount of 01 or more and 1 to 100 parts by weight of component (a).
0 parts by weight or less, preferably 5 parts by weight or less. In addition to the above components, the following optional components can be blended. Ingredient (f-1): optional ingredient At least 2 mainly made from a vinyl aromatic compound
A block copolymer consisting of one polymer block A and at least one polymer block B mainly made of a conjugated diene compound, and / or a hydrogenated block copolymer obtained by hydrogenating the same. (However, the polymer block B mainly made of a conjugated diene compound contains a polyisoprene block, and 70 to 100% by weight of isoprene.
Is a block copolymer having a 1.4-bond, or at least 9 of aliphatic double bonds derived from isoprene.
0% is hydrogenated. When this component (f-1) is used, the component (a) 10
200 parts by weight or less, preferably 150 parts by weight with respect to 0 parts by weight
Use in amounts less than parts by weight. If the amount of the component (f-1) exceeds 200 parts by weight, the moldability deteriorates. When used, the lower limit is not particularly limited, but is usually 5 parts by weight or more, preferably 10 parts by weight or more. The preferred amount is 5 to 150 parts by weight. Component (f-2): Optional component The peroxide-crosslinkable olefin resin and / or copolymer rubber containing the same in the present invention mainly undergoes a crosslinking reaction by being subjected to heat treatment in the presence of a peroxide. Use a material with reduced fluidity.
Examples of the olefin resin include high-density polyethylene (low-pressure polyethylene), low-density polyethylene (high-pressure polyethylene), and linear low-density polyethylene (ethylene and a small amount of preferably 1 to 10 mol% of butene-1 and hexene-
1, copolymers with α-olefins such as octene-1)
Such as polyethylene, ethylene-propylene copolymer,
Examples thereof include an ethylene-vinyl acetate copolymer and an ethylene-acrylate copolymer, and one or more selected from these are preferably used. Particularly preferred is ethylene • produced using a metallocene catalyst (single-site catalyst) having a density of 0.90 g / cm ³ or less.
Octene copolymer. These generally have a temperature of 19
The MFR at 0 ° C. and a load of 2.16 kg is 0.1 to 5.
0 g / 10 min, more preferably 0.3 to 1.0 g / 10
Minutes are preferred. When the component (f-2) is used, it is used in an amount of 130 parts by weight or less, preferably 80 parts by weight or less based on 100 parts by weight of the component (a). When the amount of the component (f-2) exceeds 130 parts by weight, the heat resistance of the obtained thermoplastic elastomer composition is lost, and the moldability is deteriorated. The lower limit for use is not particularly limited, but is usually 3 parts by weight or more, preferably 10 parts by weight or more. The preferred amount is from 0 to 80 parts by weight. Component (f-3): Optional component The effect of blending the peroxide-decomposable olefin-based resin and / or a copolymer rubber containing it with a rubber composition of the obtained composition is good and the appearance of the molded article is good. Having. The peroxide-decomposable olefin-based resin and / or a copolymer rubber containing the same are thermally decomposed by heat treatment in the presence of peroxide to reduce the molecular weight,
It is an olefin-based polymer or copolymer that increases the fluidity of the resin when it melts. For example, isotactic polypropylene or a copolymer of propylene with another α-olefin, ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene and the like can be mentioned. The crystallinity of the peroxide decomposable olefin resin used and / or the homo part of the copolymer rubber containing the same by DSC measurement (differential scanning calorimetry) is Tm 150 ° C. to 167.
C. and ΔHm in the range of 25 mJ / mg to 83 mJ / mg are preferred. The crystallinity is measured by Tm and ΔHm measured by DSC.
Can be estimated from Outside the above range, the rubber elasticity of the obtained elastomer composition at 100 ° C. or higher is not improved. MFR of peroxide decomposable olefin resin and / or copolymer rubber containing the same used (JI
S K 7210, 190 ° C, 2.16 kg load)
Preferably, when added at the time of dynamic crosslinking, usually 0.1 to 5
0 g / 10 min, preferably 0.5 to 20 g / 10 min. When added after the completion of dynamic crosslinking, it is usually 0.1 to 200 g / 10 min, preferably 0.5 to 60 g.
g / 10 minutes. When added at the time of dynamic cross-linking, if the MFR is less than 0.1 g / 10 minutes, the moldability of the obtained elastomer tends to decrease, and 50 g / 1
Above 0 minutes, the rubber elasticity of the obtained elastomer composition tends to deteriorate. When added after the completion of dynamic crosslinking, if the MFR is less than 0.1 g / 10 minutes, the moldability of the elastomer will be reduced, and if it is more than 200 g / 10 minutes, the rubber elasticity of the obtained elastomer composition will be deteriorated. Component (f-
When 3) is used, it is used in an amount of 130 parts by weight or less, preferably 80 parts by weight or less based on 100 parts by weight of the component (a). If the amount of the component (f-3) exceeds 130 parts by weight, the resulting thermoplastic elastomer composition will have too high a hardness to lose flexibility, and a rubber-like product cannot be obtained. The lower limit for use is not particularly limited, but is usually at least 3 parts by weight, preferably at least 10 parts by weight. The preferred amount is from 0 to 80 parts by weight. Component (f-4): Optional component A hydrogenated petroleum resin can be blended as required. When a hydrogenated petroleum resin is blended, there is an effect that the flexibility and stickiness are well-balanced, and although there is flexibility, there is no stickiness. Examples of the hydrogenated petroleum resin used in the present invention include hydrogenated petroleum resins, for example, hydrogenated aliphatic petroleum resins, hydrogenated aromatic petroleum resins, hydrogenated copolymerized petroleum resins, hydrogenated alicyclic petroleum resins, and hydrogenated petroleum resins. Terpene resin. The hydrogenated petroleum resin is obtained by hydrogenating a petroleum resin produced by a conventional method by a conventional method. The petroleum resin, petroleum refining industry, resinous products obtained in various steps of petrochemical industry, or those steps,
In particular, it refers to a resin obtained by copolymerizing an unsaturated hydrocarbon obtained in a naphtha cracking step as a raw material.
For example, an aliphatic petroleum resin whose main raw material is a C5 fraction,
Aromatic petroleum resins, their copolymerized petroleum resins, and hydrogenated alicyclic petroleum resins whose main raw material is 9 fractions. Among them, a cyclopentadiene compound and a vinyl aromatic compound are copolymerized. The hydrogenated alicyclic petroleum resin is preferably hydrogenated. When the component (f-4) is used, it is used in an amount of 100 parts by weight or less, preferably 80 parts by weight or less based on 100 parts by weight of the component (a). 10
If the amount exceeds 0 parts by weight, the surface properties of the molded article will deteriorate. Also,
The lower limit for use is not particularly limited, but is usually 1
It is more than weight part. The preferred amount is from 0 to 80 parts by weight. Component (f-5): Optional component An inorganic filler can be blended as required. The inorganic filler has an effect of improving some physical properties such as compression set of the molded article, and has an economic advantage by increasing the amount. Calcium carbonate, talc,
Magnesium hydroxide, mica, clay, parium sulfate,
Examples include natural silicic acid, synthetic silicic acid (white carbon), titanium oxide, and carpon black. Of these, calcium carbonate and talc are particularly preferred. Component (f
When -5) is used, it is used in an amount of 100 parts by weight or less, preferably 60 parts by weight or less based on 100 parts by weight of the component (a). When the amount exceeds 100 parts by weight, the mechanical strength of the obtained elastomer composition is remarkably reduced, and the hardness is increased to lose flexibility, so that a rubber-like product cannot be obtained. The lower limit for use is not particularly limited, but is usually 5 parts by weight or more. The preferred amount is 0 to 50 parts by weight. However, actually the component (a)
The ratio is determined in consideration of the compounding ratio of (f), particularly the restoring force that affects the quality of the obtained styrene-based thermoplastic elastomer composition. In addition, the composition of the present invention includes various anti-blocking agents, sealant improvers, heat stabilizers, antioxidants, antioxidants, ultraviolet absorbers depending on the application in addition to the above components,
It is also possible to have a lubricant, a nucleating agent, a coloring agent and the like.
Next, a method for producing the above-described composition of the present invention will be described. The production method is not particularly limited, and the above-described composition of the present invention can be produced by melt-kneading the components at once. Conventional melt-kneading techniques and equipment (1
Any of a screw or twin screw extruder, a roll, a Banbury mixer, various kneaders and the like can be used.

[0006]

The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to these examples.
The evaluation method used in Examples and Comparative Examples was as follows. (1) Hardness In accordance with JIS K 7215, a test piece was measured for hardness after 15 seconds using a 6.3 mm-thick press sheet. (2) Specific gravity Based on JIS K 7112, the test piece was measured using a 6.3 mm thick press sheet. (3) Flexural restoring force After leaving the metal plate (thickness 10 mm, width 50 mm, length 150 mm, roundness of the tip: R10) shown in FIG. 1 for 30 minutes in the measurement temperature atmosphere, a test piece (thickness 3 mm) , Width 10
2 mm and length 150 mm) as shown in FIG. 2 so that the center part (75 mm from the end) and the apex of the tip part are fixed, and a weight with a load of 100 g is applied from above to uniformly apply the load to the entire test piece. I made it. The metal plate and test piece fixed in this way are
After leaving at a predetermined temperature (25 ° C.) for 3 minutes, the load was released as shown in FIG. 3 and the time required for the test piece to return to a 90 ° angle was measured. The following substances were used as each component. Component (a): High Brass VS-1 manufactured by Kuraray Co., Ltd. Styrene content: 20% by weight, isoprene content: 70% by weight Hydrogenation rate: 0% Component (b): Polystyrene homopolymer, GP-1 manufactured by Denki Kagaku Kogyo MFR: 6.4 g / 10 min (200 ° C., 5 kg load) Component (c): Diana Process Oil PW-90 manufactured by Idemitsu Kosan Co., Ltd. Type: Paraffin oil Component (d): Kayahexa AD component manufactured by Kayaku Akzo (E): NK ester 3G manufactured by Shin-Nakamura Chemical Co., Ltd. Type: triethylene glycol dimethacrylate Component (f-1): Kuraray Co., Ltd. Septon 4077 Styrene content: 30% by weight, isoprene content: 70% by weight Number average Molecular weight: 260,000, Weight average molecular weight: 320,000 Molecular weight distribution: 1.23, Hydrogenation rate: 90% or more Component (f -2): Peroxide crosslinked olefin resin BondFast BF-E manufactured by Sumitomo Chemical Co., Ltd. Type: epoxy-containing ethylene copolymer MFR: 3 g / 10 minutes (190 ° C., 2.16 kg load) Component (f-3): peroxide Degradable olefin resin PP CJ700 manufactured by Idemitsu Petrochemical Co., Ltd. Type: polypropylene homopolymer, crystallinity: Tm 166 ° C. ΔHm 82 mJ / mg, MFR: 2.5 g / 10 min (190 ° C. 2.16 kg load) Component (f) -4): Hydrogenated petroleum resin Idemup P-140 manufactured by Idemitsu Petrochemical Type: Hydrogenated petroleum resin C5-aromatic copolymer hydrogenated resin Component (f-5): Filler RS400 manufactured by Sankyo Seiko Co., Ltd., Type: Calcium carbonate Experimental example 1 In experimental example 1, each component was melt-kneaded at once. Melt kneading conditions were as follows. : Twin screw extruder (L / D = 4
7), kneading temperature of 180 to 240 ° C and screw rotation speed of 100 rpm. The above-mentioned test was performed on the obtained resin composition, and the results are shown in Table 1. Comparative Example 1 Type: Styrene-based resin RIKEN VINYL INDUSTRY CO., LTD. Actimer AE-1190S Comparative Example 2 Type: Vinyl chloride-based resin RIKEN VINYL INDUSTRY CO., LTD. Company BVV0497A Comparative Example 3 Type: Olefin-based resin Mirastomer 9070N manufactured by Mitsui Chemicals, Inc.

[0007]

[Table 1]

[0008]

According to the thermoplastic elastomer composition of the present invention, when used for each molding of automobiles, the molding itself has a small restoring force and is gentle and flexible, as compared with the synthetic resin used for conventional molding. Rich in oil resistance, molding workability and vibration damping effect,
In particular, it is very easy to mount it on a molding for automobile use and has an effect of improving stability. Also, when used in fields requiring heat resistance and oil resistance, such as molding of automobiles, there is a characteristic of exhibiting a very excellent effect.

[Brief description of the drawings]

FIG. 1 is a schematic view showing the shape of a bending restoring force measuring jig of the present invention and the shape of a test piece.

FIG. 2 is a schematic view showing a fixing method of bending restoring force measurement according to the present invention.

FIG. 3 is an explanatory diagram of an experimental method for measuring a time required for a test piece to return according to the present invention.

FIG. 4 is a schematic view of a front part in which the molded article of the present invention is incorporated.

FIG. 5 is a schematic view of a method for bending and attaching a molded article according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Restoration measurement jig 2 Test piece 3 Wind molding 4 Windshield 5 Vehicle 6 Wind molding push-out position 7 Wind molding attachment position

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 53/02 C08L 53/02 (72) Inventor Naohisa Miyakawa 265-1 Kawaato Shirai-cho, Shiba-machi, Inba-gun, Chiba Pref. 72) Inventor Katsuhisa Kato 261-5 Kawato, Shirai-cho, Inba-gun, Chiba Pref.

Claims (2)

[Claims] 1. A thermoplastic elastomer composition for automobile molding used in various places such as wind molding, roof molding, protector molding and weatherstrip molding to be mounted on an automobile, wherein each of the moldings has a bending restoring force and A thermoplastic elastomer composition for automobile molding, characterized by using a thermoplastic elastomer composition having a low specific gravity and excellent in flexibility, oil resistance and moldability. 2. The thermoplastic elastomer composition according to claim 1, comprising: (a) at least two polymer blocks A mainly made of a vinyl aromatic compound and at least one polymer block B mainly made of a conjugated diene compound. And / or 100 parts by weight of a hydrogenated block copolymer obtained by hydrogenating the block copolymer. (However, including the polymer block B polyisoprene block,
Isoprene is a block copolymer in which 20 to 80% by weight of the block copolymer has a 1,4-bond and 80 to 20% by weight of the block copolymer has a 3.4-bond, or an aliphatic derivative derived from isoprene in the block copolymer. (Hydrogenated block copolymer in which at least 80% of the double bonds are hydrogenated) (b) 10 to 130 parts by weight of vinyl aromatic resin. (C) 15 to 300 parts by weight of a softener for non-aromatic rubber. (D) 0.1 to 3 parts by weight of an organic peroxide. (E) 0.1 to 10 parts by weight of a crosslinking aid. The thermoplastic elastomer composition according to claim 1, wherein the thermoplastic elastomer composition comprises: