JP2005089656A - Styrenic thermoplastic elastomer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a styrenic thermoplastic elastomer composition having good softness, extrusion moldability, surface gloss and scratch resistance. <P>SOLUTION: The styrenic thermoplastic elastomer composition comprises (a) a block copolymer composed of a polymer block of a styrenic compound and a copolymer block of the styrenic compound with a conjugated diene and having ≥50,000 and ≤100,000 weight-average molecular weight and/or its hydrogenated block copolymer, (b) an olefinic resin, (c) a softener for hydrocarbon-based rubbers and (d) a block copolymer, composed of a polymer block of a styrenic compound and a polymer block of a conjugated diene and having ≥80,000 and ≤100,000 weight-average molecular weight, in which a ratio of 1,2-conjugate occupied in a unit derived from a conjugated diene is ≥20% and ≤50% and/or its hydrogenated block copolymer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a styrenic thermoplastic elastomer composition having good flexibility, extrudability, surface gloss, and scratch resistance.

  In recent years, thermoplastic elastomers that are rubber-like soft materials that do not require a vulcanization process and that have the same molding processability as thermoplastic resins have become automotive parts, home appliance parts, electric wire coverings, medical parts, miscellaneous goods, Widely used in the field of footwear. As one kind of such thermoplastic elastomers, hydrocarbon oils and olefins are added to hydrogenated vinyl aromatic compound-conjugated diene compound block copolymers (hereinafter sometimes abbreviated as “hydrogenated block copolymers”). The thing which mix | blended the system polymer is proposed (refer patent documents 1-3).

However, these styrenic thermoplastic elastomers have a problem that the scratch resistance is insufficient and the surface gloss is inferior.
Japanese Patent Laid-Open No. 50-14742 JP 52-65551 A JP 58-206644 A

  This invention is made | formed in view of the said situation, and makes it a subject to provide a styrene-type thermoplastic elastomer composition with a favorable softness | flexibility, extrusion moldability, surface glossiness, and scratch resistance.

As a result of intensive studies, the present inventors have found that two types of block copolymers, a block copolymer that gives an elastomer composition excellent in scratch resistance and a block copolymer that gives an elastomer composition excellent in flexibility, The present inventors have found that an elastomer composition comprising an olefin resin and a hydrocarbon rubber softener exhibits excellent properties, and has completed the present invention. That is, the gist of the present invention includes the following components (a) to (d), the weight ratio of (a) / (b) is 50/50 to 95/5, and (a) and (b) (C) is contained in a ratio of 3 parts by weight to 250 parts by weight and (d) is contained in a ratio of 3 parts by weight to 150 parts by weight with respect to a total amount of 100 parts by weight. An elastomer composition.
(B) The following general formula (1)
A (BA) _m and / or (AB) _m (1)
(In the formula, A represents a polymer block of a styrene compound, B represents a copolymer block of a styrene compound and a conjugated diene, and m represents an integer of 1 to 5.)
A block copolymer having a weight average molecular weight of 50,000 to 1,000,000 and / or its hydrogenated block copolymer (b) an olefin resin (c) a hydrocarbon rubber softener (d) (2)
C (D-C) _n and / or (C-D) _n (2)
(In the formula, C represents a polymer block of a styrene-based compound, D represents a polymer block of a conjugated diene, and n represents an integer of 1 to 5.)
A block copolymer having a weight average molecular weight of 80,000 to 1,000,000, wherein the proportion of 1,2-conjugate in the structural unit derived from the conjugated diene is 20% or more and 50% or less. Polymer and / or hydrogenated block copolymer thereof

  Since the thermoplastic elastomer composition according to the present invention is excellent in flexibility, extrudability, surface gloss, and scratch resistance, for example, toy / exercise equipment use, food packaging use, daily miscellaneous goods use, desk mat, etc. Stationery applications, automotive functional parts applications, automotive interior / exterior applications, civil engineering / architecture applications such as civil engineering sheets and waterproof sheets, vibration control applications, AV / home appliance applications, OA / office equipment applications, clothing / footwear applications, textile applications, It can be used in the fields of medical equipment applications such as various catheters, sanitary products such as paper diapers and sanitary products, materials for chemical and mining industries, materials for packaging and transportation, agricultural, livestock and fishery materials.

The block copolymer of component (a) used in the thermoplastic elastomer composition according to the present invention includes a polymer block A of a styrene compound constituting a hard segment, and a styrene compound and a conjugated diene constituting a soft segment. The copolymer block B.
Examples of the styrene compound used in the polymer block A include styrene compounds such as styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene; vinyl naphthalene, Examples thereof include polycyclic aromatic compounds having a vinyl group such as vinyl anthracene. Among these, styrene compounds, particularly styrene, are preferred.

As the styrene compound used for the copolymer block B, the same styrene compound used for the polymer block A can be used.
Examples of the conjugated diene used for the copolymer block B include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc. Among these, butadiene, isoprene, or butadiene / A mixture of isoprene, in particular butadiene, is preferred. In addition, the ratio of the 1,2-conjugate in the structural unit derived from a conjugated diene is usually 10% or more and 30% or less. If this ratio is low, the coefficient of restitution tends to be high and the rubber elasticity tends to be low. Therefore, the lower limit of the ratio of 1,2-bond is preferably 13% or more. On the other hand, if this ratio is too high, the flexibility tends to be low, so the upper limit of the 1,2-conjugate ratio is preferably 25% or less.

  Component (a) is preferably a hydrogenated block copolymer obtained by hydrogenating a carbon-carbon double bond derived from the conjugated diene of the block copolymer or one containing this. The hydrogenation rate of the carbon-carbon double bond of this block copolymer is usually 30% or more. When the hydrogenation rate is low, the weather resistance and heat resistance of the elastomer composition tend to be inferior. Therefore, the hydrogenation rate is preferably 50% or more, particularly preferably 90% or more.

  The content of the polymer block A in the block copolymer of the component (a) is usually 3% by weight or more and 70% by weight or less. If the content of the polymer block A is small, the mechanical strength and heat resistance of the composition tend to be inferior. Therefore, the lower limit of the content of the polymer block A is 4% by weight or more, particularly 5% by weight or more. Is preferred. On the contrary, if the content of the polymer block A is too large, the flexibility is lost and the softening agent for hydrocarbon rubber tends to bleed, so the upper limit of the content of the polymer block A is 50% by weight. Hereinafter, 30% by weight or less is particularly preferable.

The polymer block B is preferably a random copolymer in order to give flexibility to the resulting elastomer composition and to reduce the resilience.
The weight average molecular weight in terms of polystyrene measured by gel permeation chromatography of the block copolymer of component (a) is 50,000 to 1,000,000. Since the mechanical strength of a thermoplastic elastomer composition tends to be inferior when the weight average molecular weight is small, the lower limit of the weight average molecular weight is preferably 75,000 or more. On the other hand, if it is too large, the moldability tends to be inferior, and therefore the upper limit of the weight average molecular weight is preferably 500,000 or less.

The proportion of the structural unit derived from the styrenic compound in the block copolymer of component (a) and / or the hydrogenated block copolymer thereof is usually from 50% by weight to 80% by weight. Outside this range, since the scratch resistance of the elastomer composition tends to deteriorate, the lower limit of the proportion of structural units derived from the styrene compound is preferably 55% by weight or more, and the upper limit is preferably 75% by weight or less. .
The microstructure of the conjugated diene in this block copolymer and the block copolymer of component (d) described later was measured by NMR spectrum. C. Randall, J. et al. Polym. Sci. Polym. Phs. Ed. , Vol. 13,901 (1975), and can be obtained by assigning the obtained signal.

  The block copolymer of component (a) can be produced by any known method. For example, a method of performing block polymerization in an inert solvent using a lithium catalyst or the like (see Japanese Patent Publication No. 40-23798) can be mentioned. The hydrogenation treatment of the block copolymer can be carried out in an inert solvent in the presence of a hydrogenation catalyst (Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 59- 133203, JP-A-60-79005, etc.). Examples of such a block copolymer include “Tuftec SOE-SS” (manufactured by Asahi Kasei Corporation).

  The block copolymer of component (a) can also be produced by first polymerizing a styrene compound, then copolymerizing the styrene compound and a conjugated diene, and coupling them with a coupling agent. Can do. Furthermore, it can also be produced by copolymerizing a styrene compound and a conjugated diene using a dilithium compound as an initiator, and then successively polymerizing the styrene compound.

  Examples of the component (b) olefin resin include propylene homopolymers, propylene resins such as propylene-ethylene random copolymers and propylene-ethylene block copolymers mainly composed of propylene; Copolymers, ethylene-based copolymers of ethylene and other olefins, ethylene-vinyl acetate copolymers, ethylene- (meth) acrylic acid copolymers, ethylene- (meth) acrylic acid ester copolymers, etc. Ethylene-based resin; crystalline polybutene-1 resin and the like. Among these, propylene-based resin is preferable. Moreover, the melt flow rate (JIS-K7210, 230 degreeC, 21.2N load) of propylene-type resin is 0.05-200 g / 10min normally. When the melt flow rate is out of the above range, there may be a problem in injection moldability and extrusion moldability. The melt flow rate is preferably 0.1 to 100 g / 10 min.

  Component (c) hydrocarbon rubber softeners include paraffinic, naphthenic, aromatic mineral oil hydrocarbons; synthetic resin hydrocarbons such as polybutenes, polybutadienes and other low molecular weight compounds. Can be mentioned. Mineral oil-based hydrocarbons, particularly paraffinic oils in which the carbon number of paraffinic hydrocarbons occupies 50% of the total carbon number is preferred. The weight average molecular weight of the mineral oil-based hydrocarbon is preferably 300 to 2,000, particularly 500 to 1,500, and the kinematic viscosity at 40 ° C. is preferably 20 to 800 cst, particularly preferably 50 to 600 cst. The pour point is preferably -40 to 0 ° C, particularly -30 to 0 ° C, and the flash point is preferably 200 to 400 ° C, particularly 250 to 350 ° C.

The component (d) block copolymer is composed of a polymer block C of a styrene compound constituting a hard segment and a polymer block D of a conjugated diene constituting a soft segment.
As the styrene compound used for the polymer block C, the same styrene compound used for the polymer block A can be used, and styrene is preferable. As the conjugated diene, the same conjugated diene as that used for the polymer block B can be used, and butadiene, isoprene, or a mixture of butadiene / isoprene, particularly butadiene is preferable. In the block copolymer of component (d), the proportion of 1,2-bonds of structural units derived from conjugated dienes is 20% or more and 50% or less. If this ratio is low, the coefficient of restitution becomes high and the rubber elasticity tends to be low. Therefore, the lower limit of the ratio of 1,2-bond is preferably 25% or more. On the contrary, if this ratio is too high, the flexibility tends to be low, so the upper limit of the 1,2-conjugate ratio is preferably 45% or less.

  The component (d) preferably contains a hydrogenated block copolymer obtained by hydrogenating a carbon-carbon double bond derived from the conjugated diene of the block copolymer or one containing this. The hydrogenation rate of the carbon-carbon double bond of this block copolymer is usually 30% or more. If the hydrogenation rate is low, the weather resistance and heat resistance of the elastomer composition tend to be inferior, so the hydrogenation rate is preferably 50% or more, particularly preferably 90% or more.

  The content of the polymer block C in the component (d) block copolymer is usually 10% by weight or more and 50% by weight or less. If the content of the polymer block C is small, the mechanical strength and heat resistance of the composition tend to be inferior. Therefore, the lower limit of the content of the polymer block C is 15% by weight or more, particularly 20% by weight or more. preferable. On the contrary, if the content is too large, flexibility is lost and the softening agent for hydrocarbon rubber tends to bleed, so the upper limit of the content of the polymer block C is 45% by weight or less, particularly 40% by weight. % Or less is preferable.

  The weight average molecular weight in terms of polystyrene measured by gel permeation chromatography of the block copolymer of component (d) is from 80,000 to 1,000,000. If the weight average molecular weight is small, the thermoplastic elastomer composition tends to be inferior in rubber elasticity, mechanical strength and extrusion processability, so the lower limit of the weight average molecular weight is preferably 100,000 or more, particularly preferably 150,000 or more. On the contrary, since the extrusion processability tends to be inferior even if it is too large, the upper limit of the weight average molecular weight is preferably 500,000 or less, particularly preferably 400,000 or less.

The block copolymer of component (d) can be produced by any known method, for example, a method according to the method for producing component (a) described above. Examples of such block copolymers that can be obtained on the market include “KRATON-G” (manufactured by Kraton Polymer Co., Ltd.), “Septon” (manufactured by Kuraray Co., Ltd.), “Tuff Tech” (manufactured by Asahi Kasei Co., Ltd.), and the like. Can be mentioned.
The thermoplastic elastomer composition according to the present invention can be produced by mixing the components (A) to (D). The blending ratio of component (I) / (B) is 50/50 to 95/5. If the proportion of component (a) is low, the elastomer composition may be inferior in scratch resistance and flexibility, whereas if the proportion is too high, the heat resistance, injection molding processability and extrusion processability tend to be inferior. . Therefore, the blending ratio of (A) / (B) is preferably 55/45 to 90/10, particularly 60/40 to 85/15.

  The ratio of the component (C) to the total of 100 parts by weight of the components (A) and (B) is 3 parts by weight or more and 250 parts by weight or less. If the proportion of the component (c) is low, the flexibility of the elastomer composition may be inferior, so the proportion of the component (c) is preferably 5 parts by weight or more, particularly preferably 7 parts by weight or more. Conversely, if the proportion is too high, the component (c) tends to bleed out, so the proportion of the component (c) is preferably 200 parts by weight or less, particularly preferably 150 parts by weight or less.

The ratio of component (d) to 100 parts by weight of the total of components (a) and (b) is 3 parts by weight or more and 150 parts by weight or less. If the component (d) is low, the elastomer composition tends to be inferior in flexibility, so the lower limit of the proportion of the component (d) is preferably 5 parts by weight or more, particularly preferably 7 parts by weight or more. Conversely, if the ratio is too high, the scratch resistance tends to be inferior, and therefore the upper limit of the ratio of component (d) is preferably 130 parts by weight or less, particularly preferably 100 parts by weight or less.
The thermoplastic elastomer composition according to the present invention may be subjected to dynamic heat treatment in the presence of a crosslinking agent. This treatment can improve the heat resistance and oil resistance of the elastomer composition. In the dynamic heat treatment, the components (a) to (d) are uniformly mixed using a mixing apparatus such as a Henschel mixer, a ribbon blender, or a V-type blender, and then mixed with a mixing roll, kneader, Banbury mixer, Brabender plastograph, uniaxial Or it can carry out by melt-kneading using kneading apparatuses, such as a twin-screw extruder.

  In the dynamic heat treatment, a crosslinking agent and a crosslinking aid may be added. Examples of the crosslinking agent include organic peroxides, sulfur, maleimide crosslinking agents, phenolic crosslinking agents, oximes and polyamines. Among these, organic peroxides, maleimides or phenolic crosslinking agents, particularly organic peroxides. Oxides are preferred.

  Examples of the organic peroxide include di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, , 5-Dimethyl-2,5-di (t-butylperoxy) hexyne-3, 1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-di (t-butylperoxy) -3 Dialkyl peroxides such as 1,3,5-trimethylcyclohexane; t-butylperoxybenzoate, t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5 -Peroxyesters such as dimethyl-2,5-di (benzoylperoxy) hexyne-3; acetyl peroxide, lauroylper Kishido, benzoyl peroxide, p- chlorobenzoyl peroxide, 2,4-diacyl peroxides such as benzoyl peroxide and the like; and hydroperoxides such as diisopropylbenzene hydroperoxide and the like. Among these, those having a half-life temperature of 140 ° C. or more, for example, 1,3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylper) Oxy) hexane or 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 is preferred.

  Examples of the crosslinking aid include peroxide crosslinking aids such as sulfur, p-quinonedioxime, p-dinitrosobenzene, 1,3-diphenylguanidine, m-phenylenebismaleimide; divinylbenzene, triallylcia Polyfunctional vinyl compounds such as nurate, triallyl isocyanurate, diallyl phthalate; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, allyl Polyfunctional (meth) acrylate compounds, such as (meth) acrylate, etc. are mentioned.

  The dynamic heat treatment is usually performed by heating and kneading at a temperature of 100 to 300 ° C., preferably 110 to 280 ° C., usually for 10 seconds to 30 minutes, preferably 20 seconds to 20 minutes. The organic peroxide is generally used in an amount of 0.1 to 3 parts by weight, preferably 0.1 to 1 part by weight, based on 100 parts by weight of the total of components (A) to (D). The crosslinking aid is usually used in an amount of 5 parts by weight or less, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the total of components (A) to (D). In addition, although the reaction mixture will be in a semi-molten state or a molten state depending on the types of components (a) to (d) used and the temperature of the dynamic heat treatment, any of them may be used in the present invention. In addition, when kneading, a method of kneading each component at a time may be used, or a multistage division kneading method may be used in which an arbitrary component is kneaded and then the other remaining components are added and kneaded.

In addition to the components (a) to (d), other components can be added to the thermoplastic elastomer composition according to the present invention as long as the effects of the present invention are not impaired.
Other components include, for example, fillers, antioxidants, heat stabilizers, light stabilizers, UV absorbers, neutralizers, lubricants, antifogging agents, antiblocking agents, slip agents, dispersants, colorants, Various additives such as flame retardants, antistatic agents, conductivity-imparting agents, metal deactivators, molecular weight modifiers, antibacterial agents, antifungal agents, fluorescent whitening agents, other thermoplastic resins, other elastomers, etc. Is mentioned. These may be used alone or in combination.

Examples of the filler include glass fiber, hollow glass sphere, carbon fiber, talc, calcium carbonate, mica, potassium titanate fiber, silica, metal soap, titanium dioxide, and carbon black.
Examples of other thermoplastic resins include polyphenylene ether resins, polyamide resins such as nylon 6 and nylon 66; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyoxymethylene homopolymers and polyoxymethylene copolymers. Examples include polyoxymethylene resins; polymethylmethacrylate resins.

Examples of other elastomers include olefin rubbers such as ethylene / propylene copolymer rubber and ethylene / propylene / non-conjugated diene copolymer rubber; styrene rubbers other than (A) and (D); polybutadiene and the like. It is done.
The other components may be preliminarily contained in any of the components (a) to (d), or may be mixed either at the time of mixing each component or at the time of dynamic heat treatment.

  The thermoplastic elastomer composition according to the present invention includes, for example, injection molding (insert molding method, two-color molding method, sandwich molding method, gas injection molding method, etc.), extrusion molding method, inflation molding method, T-die film molding method, It can be formed by a molding method such as a laminate molding method, a blow molding method, a hollow molding method, a compression molding method, or a calendar molding method. Furthermore, after molding, it may be used alone or as a laminate with other materials by secondary processing such as lamination molding or thermoforming.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In addition, the component (a)-(d) used by the Example and the comparative example is as follows.
Component (I): Hydrogenated styrene-styrene-butadiene block copolymer having a copolymer structure of styrene block-styrene / butadiene random copolymer block-styrene block (total styrene content: 66% by weight, styrene block Content: 18% by weight, hydrogenation rate: 99%, weight average molecular weight: 172,000, 1,2-vinyl bond content of butadiene: 14.1%, SOE-SS “L601” manufactured by Asahi Kasei Corporation)
Component (b): Propylene polymer resin (melt flow rate: 0.9 g / 10 min)
Component (C): Paraffinic oil (weight average molecular weight: 540, “PW90” manufactured by Idemitsu Kosan Co., Ltd.).
Component (d): Hydrogenated styrene-butadiene block copolymer having a copolymer structure of styrene block-butadiene block-styrene block (styrene block content: 33% by weight, hydrogenation rate: 98% or more, weight average (Molecular weight: 245,000, 1,2-vinyl bond content in butadiene block: 37%)

Evaluation Method (1) was measured using pellets of the thermoplastic elastomer composition. In addition, a sheet (120 mm wide, 80 mm long) obtained by injection molding with an inline screw type injection molding machine (“IS130” manufactured by Toshiba Machine Co., Ltd.) under conditions of an injection pressure of 50 MPa, a cylinder temperature of 220 ° C., and a mold temperature of 40 ° C. (2) to (5) were measured using a thickness of 2 mm.
(1) MFR: JIS K7210 compliant (230 ° C, load 5 kg)
(2) Hardness: JIS K6253 compliant (JIS-A)
(3) Gloss: JIS Z8741 compliant (4) Scratch resistance: Using a Toyo Seiki Co., Ltd. (Tavers clutch tester), the surface of the styrene thermoplastic elastomer sheet was scratched with a tungsten carbide cutter at a weight of 700 g. The surface was visually evaluated in the following three stages.
○: Not scratched △: Almost scratched ×: Scratched (5) Injection moldability: Styrenic thermoplastic elastomer sheet does not have short shots, and there are significant appearance defects such as delamination and flow marks near the gate. If not, the moldability was good, and if there was either a shortcut or a significant appearance failure, the moldability was bad.
(6) Extrudability: From a pipe die of a 40 mmφ pipe forming machine (full flight type screw, L / D = 28, manufactured by IK Corporation), cylinder temperature 190 ° C., die temperature 190 ° C., screw rotation speed 20 rpm Thus, an elastomer tubular body having an outer diameter of 8 mm and an inner diameter of 5 mm was produced. Extrusion processability is good when there is no problem in extrusion molding and there is no remarkable appearance defect in the produced elastomeric tubular body, and extrusion processability is good when there is a problem in extrusion molding or there is a remarkable appearance defect. Defective.

Examples 1-2 and Comparative Examples 1-2
Tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4) is used with respect to 100 parts by weight of the total amount of components (A) to (D) of the elastomer composition blended in the composition shown in Table 1. '-Hydroxyphenyl) propionate] methane ("Irganox 1010", manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.1 part by weight was added, and the compression ratio L / D was 33 and the cylinder diameter was 45 mm using a twin screw extruder. The mixture was melt kneaded at a temperature of 0 ° C., extruded from a die in a strand shape, and cut to obtain pellets of a thermoplastic elastomer composition. The obtained pellets were evaluated by the above method. The results are shown in Table 1.

Claims (10)

The following components (a) to (d) are contained, the weight ratio of (a) / (b) is 50/50 to 95/5, and the total amount of (a) and (b) is 100 parts by weight. (Iii) is contained in a proportion of 3 to 250 parts by weight, and (d) is contained in a proportion of 3 to 150 parts by weight.
(B) The following general formula (1)
A (BA) _m and / or (AB) _m (1)
(In the formula, A represents a polymer block of a styrene compound, B represents a copolymer block of a styrene compound and a conjugated diene, and m represents an integer of 1 to 5.)
A block copolymer having a weight average molecular weight of 50,000 to 1,000,000 and / or its hydrogenated block copolymer (b) an olefin resin (c) a hydrocarbon rubber softener (d) (2)
C (D-C) _n and / or (C-D) _n (2)
(In the formula, C represents a polymer block of a styrene-based compound, D represents a polymer block of a conjugated diene, and n represents an integer of 1 to 5.)
A block copolymer having a weight average molecular weight of 80,000 to 1,000,000, wherein the proportion of 1,2-conjugate in the structural unit derived from the conjugated diene is 20% or more and 50% or less. Polymer and / or hydrogenated block copolymer thereof The styrenic thermoplastic elastomer composition according to claim 1, wherein the styrenic compounds of A and B are styrene. 3. The styrenic thermoplastic elastomer composition according to claim 1, wherein the conjugated diene of B is butadiene. The styrene thermoplastic elastomer composition according to claim 3, wherein the proportion of 1,2-bonds in the structural unit derived from butadiene is 10% or more and 30% or less. The ratio of the polymer block A in the block copolymer of component (a) and / or the hydrogenated block copolymer thereof is 3 wt% or more and 70 wt% or less. A styrenic thermoplastic elastomer composition as described above. The proportion of the structural unit derived from the styrenic compound in the block copolymer of component (a) and / or the hydrogenated block copolymer thereof is 50 wt% or more and 80 wt% or less. The styrenic thermoplastic elastomer composition according to any one of 1 to 5. The styrene thermoplastic elastomer composition according to any one of claims 1 to 6, wherein the olefin resin is a propylene polymer. The styrenic thermoplastic elastomer composition according to any one of claims 1 to 7, wherein the styrene compound of C is styrene. 9. The styrenic thermoplastic elastomer composition according to claim 1, wherein the conjugated diene of D is butadiene and / or isoprene. The ratio of the polymer block C to the block copolymer of component (d) and / or the hydrogenated block copolymer thereof is 10% by weight or more and 50% by weight or less. The styrenic thermoplastic elastomer composition according to any one of the above.