JP5568327B2 - Thermoplastic elastomer composition - Google Patents

Description

  The present invention relates to a thermoplastic elastomer composition used for sealing materials, packing, vibration damping members, tubes, industrial articles, sundries, sports applications and the like.

  Conventionally, as a thermoplastic elastomer composition having flexibility and rubber elasticity, a composition comprising a hydrogenated block copolymer containing a block unit of a polymer composed of a styrene monomer, an oil, and a polyolefin polymer Is widely used (see Patent Documents 1 and 2). Polypropylene is generally used as the polyolefin polymer, but some compositions containing polyethylene are also known (see Patent Document 3).

  Moreover, as a thermoplastic elastomer composition having good chlorine water resistance, there is a composition using a silane-crosslinked polyolefin (see Patent Documents 4 and 5).

JP 2000-103934 A JP-A-8-34900 JP 2001-240720 A JP-A 61-159441 JP 2000-219785 A

  Since the composition described in Patent Document 3 has a large molecular weight of the block copolymer, it has insufficient fluidity and lacks moldability.

  In addition, a highly flexible thermoplastic elastomer composition tends to deteriorate the copolymer in an environment such as chlorine water. Although the compositions described in Patent Documents 4 and 5 have good chlorine water resistance, they are disadvantageous in terms of low productivity and hygiene due to silane crosslinking, and are expensive in terms of cost.

  An object of the present invention is to provide a thermoplastic elastomer composition having good moldability and productivity, excellent chlorine water resistance, and good restoring force after compression.

The present invention
(A) hydrogenated thermoplastic styrenic elastomer,
(B) Paraffin oil having a kinematic viscosity at 40 ° C. of ²⁰ to 1000 mm ² / s ,
(C) polyethylene having a density of 870 to 940 kg / m ³ , a melt mass flow rate of 100 g / 10 min or less at 190 ° C. and a load of 2.16 kg measured according to JIS K6922-2 , and
(D) a thermoplastic elastomer composition comprising a compatibilizing agent which is a block copolymer having at least one amorphous part block and a crystalline polyolefin block in the molecule , The hydrogenated thermoplastic styrenic elastomer comprises a group consisting of a styrene-ethylene-butylene-styrene block copolymer, a styrene-ethylene-propylene-styrene block copolymer, and a styrene-ethylene-ethylene-propylene-styrene block copolymer. It is made of an elastomer having a weight average molecular weight of 180,000 to 250,000, which is at least one selected, and the content of the paraffin oil is 50 to 300 parts by mass with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. The content of the polyethylene is the hydrogenated thermoplastic styrenic elastomer Per 100 parts by mass, 10 to 200 parts by weight, the thermoplastic elastomer composition (although, di-block copolymer of the polymer block and an elastomeric polymer block of a vinyl aromatic hydrocarbon and / or a hydrogenated Excluding things including things)
About.

  The thermoplastic elastomer composition of the present invention has excellent moldability and productivity, excellent chlorine water resistance, and excellent restoring force after compression.

The thermoplastic elastomer composition of the present invention comprises:
(A) A hydrogenated product of a block copolymer (Z) comprising a block unit (s) of a polymer comprising a styrene monomer and a block unit (b) of a polymer comprising a conjugated diene compound. Hydrogenated thermoplastic styrenic elastomer,
It contains (B) paraffin oil and (C) polyethylene, and contains specific amounts of paraffin oil and polyethylene with respect to the hydrogenated thermoplastic styrene-based elastomer.

  In the hydrogenated block copolymer (Z), styrene monomers constituting the block unit (s) include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1, Examples include 3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, and vinylanthracene.

  The block copolymer (Z) consists of a hard part (hard segment) composed of block units (s) and a soft part (soft segment) composed of block units (b), from the viewpoint of determining the overall physical properties. The content of the block unit (s) in the block copolymer (Z) is preferably 5 to 80% by mass, more preferably 10 to 70% by mass, and further preferably 15 to 40% by mass.

  Examples of the conjugated diene compound constituting the block unit (b) include butadiene, isoprene, 1,3-pentadiene and the like.

  Specific examples of the hydrogenated thermoplastic styrene elastomer include styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene block copolymer, styrene-ethylene-ethylene-propylene-styrene block copolymer. , Styrene-butadiene rubber, acrylonitrile-butadiene rubber, pyridine-butadiene rubber, styrene-isoprene rubber, styrene-ethylene copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, poly ( α-methylstyrene) -polybutadiene-poly (α-methylstyrene), poly (α-methylstyrene) -polyisoprene-poly (α-methylstyrene), ethylene-propylene copolymer, styrene-chloroprene rubber, etc. . These may be used singly or as a mixture of two or more. From the viewpoint of raw material preparation and workability, styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene. -It is preferably at least one selected from the group consisting of a styrene block copolymer (SEPS) and a styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), and in particular the block unit (b) SEBS having fewer branched chains in the conjugated diene compound portion is more preferable.

  The block copolymer (Z) may be partially or completely hydrogenated, but the unsaturated bond is reduced by hydrogenation, and heat resistance, weather resistance and mechanical properties are obtained. It is done. From these viewpoints, the hydrogenation rate is preferably 80% or more, and more preferably 90% or more.

  The weight average molecular weight of the hydrogenated thermoplastic styrenic elastomer is 180,000 to 500,000. From the viewpoint of heat resistance and mechanical properties, it is 180,000 or more, preferably 190,000 or more, more preferably 200,000 or more. Further, from the viewpoint of ease of flow during heating, that is, formability during production, it is 500,000 or less, preferably 300,000 or less, more preferably 250,000 or less. From these viewpoints, the weight average molecular weight of the hydrogenated thermoplastic styrenic elastomer is preferably 190,000 to 300,000, more preferably 200,000 to 250,000.

The kinematic viscosity of paraffin oil at 40 ° C. is 20 to 1000 mm ² / s. If the kinematic viscosity is too low, it tends to volatilize and the storage stability of the resulting composition may decrease, so it is 20 mm ² / s or more, preferably 25 mm ² / s or more, more preferably 30 mm ² / s. That's it. If the kinematic viscosity is too high, deficiencies in operability during production occur, and therefore, it is 1000 mm ² / s or less, preferably 700 mm ² / s or less, more preferably 500 mm ² / s or less. From these viewpoints, the kinematic viscosity of paraffin oil at 40 ° C. is preferably 25 to 700 mm ² / s, more preferably 30 to 500 mm ² / s.

  The content of the paraffin oil is 50 to 300 parts by mass with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. If the content of paraffin oil is too small, the dispersibility of various blending components decreases, so the amount is 50 parts by mass or more, preferably 55 parts by mass or more, with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. Preferably it is 60 parts by mass or more. Further, if the content of paraffin oil is too large, oil bleed occurs, leading to deterioration of physical properties and the like. Therefore, it is 300 parts by mass or less, preferably 290 parts per 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. It is not more than part by mass, more preferably not more than 280 parts by mass. From these viewpoints, the content of paraffin oil is preferably 55 to 290 parts by mass, more preferably 60 to 280 parts by mass with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer.

The density of polyethylene is 870-940 kg / m ³ . If the density is too low, the numerical value of the compression set (CS) is increased, because the restoring force after compression is reduced, and the 870 kg / m ³ or more, preferably 875kg / m ³ or more, more preferably 880 kg / m ³ or more. Further, when the density is too high, familiar with the paraffin oil is poor, since the oil bleeding is likely to occur, and at 940 kg / m ³ or less, preferably 935 kg / m ³ or less, more preferably 930 kg / m ³ or less is there. From these viewpoints, the density of polyethylene is preferably 875 to 935 kg / m ³ , more preferably 880 to 930 kg / m ³ .

  The melt mass flow rate (MFR) of polyethylene is 100 g / 10 min or less. If the MFR is too high, the shearing force is not applied during kneading and kneading cannot be performed, so that it is 100 g / 10 min or less, preferably 80 g / 10 min or less, more preferably 50 g / 10 min or less. Further, if the MFR is too low, the temperature applied to the molding material at the time of molding becomes higher and the processing becomes difficult. Therefore, it is preferably 0.3 g / 10 min or more, more preferably 0.5 g / 10 min or more. From these viewpoints, the melt mass flow rate of polyethylene is preferably 0.3 to 80 g / 10 min, more preferably 0.5 to 50 g / 10 min.

  The content of polyethylene is 10 to 200 parts by mass with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. Polyethylene has the effect of imparting plasticity (can be molded into a free shape) and the effect of `` bonding '' for kneading during kneading. Both effects are adequately exhibited when the polyethylene content is low. Not. From this viewpoint, the amount is 10 parts by mass or more, preferably 15 parts by mass or more, and more preferably 20 parts by mass or more with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. Further, since the hard property becomes strong when the polyethylene content is too large, it is 200 parts by mass or less, preferably 180 parts by mass or less, more preferably 160 parts by mass with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. Or less. From these viewpoints, the content of polyethylene is preferably 15 to 180 parts by mass, more preferably 20 to 160 parts by mass with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer.

  The thermoplastic elastomer composition of the present invention preferably further contains a compatibilizer from the viewpoint of reducing stickiness and improving the feeling of use.

  As the compatibilizing agent, a block copolymer having at least one block A of amorphous part (rubber part) and crystalline polyolefin block B in the molecule is preferable.

The structure of the block copolymer having at least one block A and block B in the molecule is not particularly limited, and (BA) n ₁ , (BA) n ₂ -B, (A -B) n ₃ -A (n ₁ , n ₂ and n ₃ are integers of 1 or more) and structures in which these are bound by a coupling agent are exemplified. Among these, a triblock copolymer or a copolymer having a larger number of blocks is preferable.

  As such a copolymer, a copolymer comprising a polymer block A ′ mainly composed of a conjugated diene compound and a block B ′ mainly composed of a conjugated diene compound and having a portion capable of becoming a crystalline polyolefin by a crosslinking treatment or the like. There is.

  Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene and the like.

  The polymer block A ′ mainly composed of a conjugated diene compound is a block that can become an amorphous polyolefin rubbery polymer block after hydrogenation. For example, if the polybutadiene has a vinyl bond (content of 1,2- and 3,4-bond) of about 25 to 85%, the structure similar to that of a rubber-like ethylene-butene copolymer block is obtained by hydrogenation. The resulting amorphous block.

  The block B ′ having a portion that can become a crystalline polyolefin, for example, can be converted into an ethylene polymer by hydrogenation if the vinyl bond (content of 1,2- and 3,4-bonds) of polybutadiene is about 25% or less. It becomes a crystalline block showing a similar structure.

  As such a block copolymer, there is a block copolymer of an olefin block forming a highly crystalline polymer such as polypropylene as a hard part and a monomer copolymer block showing an amorphous property as a soft part. Specifically, olefin crystal block polymers such as olefin crystals, ethylene-butylene copolymers, olefin crystals (CEBC), ethylene-ethylene-butylene-ethylene block copolymers, propylene-polyethylene oxide-propylene blocks Examples thereof include a copolymer and a propylene-olefin (amorphous) -propylene block copolymer. These may be used alone or in combination of two or more.

  Furthermore, as a block copolymer that can be used as a compatibilizing agent in the present invention, a part of the block B constituting the block copolymer represented by the above general formula is replaced with a block C of a polymer of a vinyl aromatic compound. There may also be block copolymers.

  Specific examples of the vinyl aromatic compound include styrene, t-butyl styrene, α-methyl styrene, p-methyl styrene, divinyl styrene, 1,1-diphenyl styrene, etc. Among these, styrene and α Methyl styrene is preferred.

  As a block copolymer including the block C made of a polymer of a vinyl aromatic compound, there is a block copolymer represented by B-A-C, such as a styrene-ethylene-butylene-olefin crystal block copolymer. Can be mentioned.

  In the present invention, the compatibilizing agent may be used singly or as a mixture of two or more, but polyethylene hardly affects the aqueous sodium hypochlorite solution. A styrene-ethylene-butylene-olefin crystal block copolymer (SEBC) is preferred from the viewpoint of improving the chlorine water resistance by “adapting” polyethylene having strong chlorine water resistance with a hydrogenated thermoplastic styrene elastomer.

  The content of the compatibilizer is preferably 5 parts by mass or more, and 10 parts by mass or more with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer from the viewpoint of “familiarity” between the hydrogenated thermoplastic styrene elastomer and polyethylene. Is more preferable. Further, from the viewpoint of preventing deterioration of chlorine water resistance and mechanical properties, the amount is preferably 30 parts by mass or less and more preferably 20 parts by mass or less with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. From these viewpoints, the content of the compatibilizing agent is preferably 5 to 30 parts by mass, more preferably 10 to 20 parts by mass with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer.

  The thermoplastic elastomer composition of the present invention preferably further contains polyphenylene ether from the viewpoint of improving compression set.

  The polyphenylene ether has an effect of improving the tensile strength of the obtained elastomer composition at a high temperature (for example, 70 ° C.), and imparts a reduction in compression set to the elastomer composition. The polyphenylene ether may be a modified polyphenylene ether in which a styrene resin is blended or grafted.

  From the viewpoint of improving compression set, the content of polyphenylene ether is preferably 3 parts by mass or more and more preferably 5 parts by mass or more with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. Further, from the viewpoint of preventing an increase in permanent elongation accompanying a decrease in rubber elasticity of the elastomer composition, it is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. . From these viewpoints, the content of the modifier is preferably 3 to 30 parts by mass, more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer.

  The thermoplastic elastomer composition of the present invention is, as necessary, a reinforcing agent such as carbon black, silica, carbon fiber, glass fiber, etc. within a range not impairing the effects of the present invention; calcium carbonate, talc, clay, titanium oxide, Fillers such as mica; lubricants, light stabilizers, antioxidants, ultraviolet absorbers, pigments, flame retardants, antistatic agents, mold release agents, tackifiers, crosslinking agents, crosslinking aids, foaming agents, fragrances, etc. Various additives may be contained.

  In addition, the thermoplastic elastomer composition of the present invention may appropriately contain other polymers as long as the effects of the present invention are not impaired.

  The thermoplastic elastomer composition of the present invention is, for example, a hydrogenated thermoplastic styrene-based elastomer, paraffin oil, polyethylene, and if necessary, a mixture of raw materials containing a compatibilizer, polyphenylene ether, etc., and is solidified by cooling. Obtained. From the viewpoint of uniform dispersion, the raw material mixture is preferably obtained by dry-mixing raw materials other than paraffin oil and mixing the resulting mixture with paraffin oil by a method such as impregnation with paraffin oil. A method and a shape for solidifying the melt-kneaded material are not particularly limited, but it is preferable to form into a pellet shape that is easy to handle by injection molding or the like.

  “Mixing” as used in the present invention is not particularly limited as long as various components are mixed well, and various components may be dissolved and mixed in a soluble organic solvent, or by melt kneading. You may mix. The former mixing method requires a relatively large amount of organic solvent, and the latter melt-kneading method, which is industrially simple, is preferable in consideration of costs, natural environment, workplace environment, fire-fighting regulations, and the like.

  When melt-kneading, a general extruder can be used, and it is preferable to use a twin-screw extruder for improving the kneading state. Supply to the extruder may be provided by mixing various components in advance from one hopper, or may be provided while charging each component in two hoppers and quantifying with a screw or the like under the hopper. The melt kneading temperature is preferably equal to or higher than the melting point of the elastomer or the like. Further, the upper limit is preferably 350 ° C. or less, and more preferably 300 ° C. or less, from the viewpoint of preventing the oxidation and thermal decomposition of the elastomer.

  The hardness of the thermoplastic elastomer composition of the present invention is preferably 80 or less from the viewpoint of exhibiting good flexibility and obtaining sufficient sealability (sealing property) in the case of using as a sealing material or packing, etc. The following is more preferable. Further, from the viewpoint of shape retention, mechanical properties, and oil bleeding, 20 or more is preferable, and 30 or more is preferable. From these viewpoints, the hardness of the thermoplastic elastomer composition is preferably 80 or less, more preferably 20 to 50, and still more preferably 30 to 50. The hardness of the composition is measured according to JIS K 6253A.

  Various physical properties of the raw materials used in Examples and Comparative Examples were measured by the following methods.

(Weight average molecular weight of hydrogenated thermoplastic elastomer (Mw))
Under the following measurement conditions, the molecular weight is measured in terms of polystyrene by gel permeation chromatography, and the weight average molecular weight is determined.

Measuring instrument: SIC Autosampler Model 109
Sugai U-620 COLUMN HEATER
Uniflows UF-3005S2B2
Detector: MILLIPORE Waters 410
Differential Refractometer
Column: Shodex KF806M x 2 Oven temperature: 40 ° C
Eluent: Tetrahydrofuran (THF) 1.0ml / min
Standard sample: Polystyrene sample solution: Mix the sample with THF to which 0.2 mass% of 2,6-di-t-butyl-p-phenol (BHT) is added so that the concentration is 0.020 g / 10 ml, and stir at room temperature And dissolve.
Sample solution injection volume: 100 μl
Correction: The molecular weight calculation is performed by correcting the deviation of the BHT peak between the calibration curve measurement and the sample measurement.

[Kinematic viscosity of paraffin oil]
Measure at a temperature of 40 ° C according to JIS-Z-8803.

[Polyethylene melt mass flow rate (MFR)]
Measured in accordance with JIS K6922-2 under test conditions of 190 ° C and 2.16 kg load.

Examples 1 to 9 and Comparative Examples 1 to 14 (Examples 1 5 are reference examples)
The raw materials shown in Tables 1 and 2 other than paraffin oil were dry-mixed and then impregnated with paraffin oil to obtain a mixture. The obtained mixture was melt-kneaded with an extruder (manufactured by Technobel, KZW32TW-60MG-NH, cylinder temperature: 160 to 220 ° C., screw rotation speed: 300 r / min). However, in Comparative Example 2 in which paraffin oil having too high kinematic viscosity was used, the raw material was not impregnated with the paraffin oil, and melt kneading could not be performed.

  The details of the raw materials described in Tables 1 and 2 used in Examples and Comparative Examples are as follows.

[SBC (hydrogenated thermoplastic styrene elastomer)]
SEBS A: G1651 (Clayton), Mw 210,000, Block unit (s) content 33% by mass
SEBS B: G1650 (Clayton), Mw 109,000, block unit (s) content 29% by mass
SEEPS: Septon 4099 (manufactured by Kuraray), Mw 422,000, block unit (s) content 30% by mass

〔oil〕
Paraffin oil A: PW-90 (made by Idemitsu Kosan Co., Ltd.), kinematic viscosity (40 ° C) 84mm ² / s
Paraffin oil B: Lucant HC-100 (Mitsui Chemicals), kinematic viscosity (40 ° C) 1300mm ² / s

[PE (polyethylene)]
LLDPE (Ultra Low Density Polyethylene): NUCG5651 (Nihon Unicar), density 920kg / m ³ , MFR 1.0g / 10min, flexural modulus 215MPa
LDPE (low density polyethylene) A: Novatec LJ-808 (manufactured by Nippon Polyethylene), density 917kg / m ³ , MFR 21g / 10min, flexural modulus 110MPa
LDPE B: Petrocene 353 (manufactured by Tosoh Corporation), density 915kg / m ³ , MFR 145g / 10min, flexural modulus 90MPa
HDPE (High Density Polyethylene): Nipolon Hard HD-1000 (manufactured by Tosoh Corporation), density 964kg / m ³ , MFR 20g / 10min, flexural modulus 1160MPa

[PP (polypropylene)]
Homo PP: PM600A (manufactured by Sun Allomer), density 900kg / m ³ , flexural modulus 1650MPa

[Compatibilizer]
SEBC: Dynalon 4600P (manufactured by JSR), MFR 5.6g / 10min, styrene monomer content 20% by mass

[Other additives]
PPE (polyphenylene ether): PX100L (Mitsubishi Engineering Plastics)

  The obtained melt-kneaded product was extruded into strands and cut into pellets having a diameter of about 3 mm and a thickness of about 3 mm with a cutter while cooling in cold water.

The pellets are injection molded under the following conditions, and two types of plates with different sizes:
Plate A: 2mm thick x 125mm wide x 125mm long
Plate B: 6mm thick x 25mm wide x 125mm long
Molded into.

[Injection molding conditions]
Injection molding machine: 100MSIII-10E, manufactured by Mitsubishi Heavy Industries, Ltd.
Injection molding temperature: 170 ° C
Injection pressure: 30%
Injection time: 10 seconds Mold temperature: 40 ℃

  Using the plate A or the plate B, hardness, chlorine water resistance, compression set, dispersibility, and stickiness were measured or evaluated by the following methods.

〔Hardness〕
Using plate B, measure according to JIS K 6253A.

[Chlorine resistant]
Plate A is immersed for 15 days in 100 ppm active chlorine concentration sodium hypochlorite at 60 ° C. Since the active chlorine concentration becomes inactive over time when the temperature is high, new chlorine water is replaced every 24 hours. After 15 days, the plate is taken out and washed with water, the change in appearance is visually observed, and the chlorine water resistance is evaluated according to the following evaluation criteria.

<Evaluation criteria>
○: No change in appearance △: Some change in yellowing, swelling, etc. ×: Yellowing, swelling

(Compression set (CS))
Measurement is performed under the conditions of 70 ° C. × 24 hours according to JIS K 6262, using a test piece in which seven plates A are stacked and adjusted to a thickness of 13 mm by compression.

〔dispersion〕
The plate B is cut, and the dispersion state of the unmelted material and the like in the cross section and the unevenness on the surface are visually observed, and ◯: good or x: bad is evaluated.

[Sticky]
Based on the touch of the plate, the stickiness is evaluated according to the following evaluation criteria.

<Evaluation criteria>
◎: No stickiness ○: Slightly sticky △: Sticky ×: Sticky

  From the above result, in Examples 1-9, compared with Comparative Examples 1-14, it is excellent in the softness | flexibility of a composition and chlorine water resistance, and the restoring force after compression is also favorable, and dispersion | distribution and usability of various components It turns out that it is also favorable.

  The thermoplastic elastomer composition of the present invention is used for sealing materials, packing, vibration damping members, tubes, industrial articles, miscellaneous goods, sports applications and the like.

Claims (4)

(A) hydrogenated thermoplastic styrenic elastomer,
(B) Paraffin oil having a kinematic viscosity at 40 ° C. of ²⁰ to 1000 mm ² / s ,
(C) polyethylene having a density of 870 to 940 kg / m ³ , a melt mass flow rate of 100 g / 10 min or less at 190 ° C. and a load of 2.16 kg measured according to JIS K6922-2 , and
(D) a thermoplastic elastomer composition comprising a compatibilizing agent which is a block copolymer having at least one amorphous part block and a crystalline polyolefin block in the molecule , The hydrogenated thermoplastic styrenic elastomer comprises a group consisting of a styrene-ethylene-butylene-styrene block copolymer, a styrene-ethylene-propylene-styrene block copolymer, and a styrene-ethylene-ethylene-propylene-styrene block copolymer. It is made of an elastomer having a weight average molecular weight of 180,000 to 250,000, which is at least one selected, and the content of the paraffin oil is 50 to 300 parts by mass with respect to 100 parts by mass of the hydrogenated thermoplastic styrene elastomer. The content of the polyethylene is the hydrogenated thermoplastic styrenic elastomer Per 100 parts by mass, 10 to 200 parts by weight, the thermoplastic elastomer composition (although, di-block copolymer of the polymer block and an elastomeric polymer block of a vinyl aromatic hydrocarbon and / or a hydrogenated Excluding things that contain things) .   The thermoplastic elastomer composition according to claim 1, wherein the hardness of the composition measured according to JIS K 6253A is 80 or less. The thermoplastic elastomer composition according to claim 1 or 2 , wherein the compatibilizing agent is a styrene-ethylene-butylene-olefin crystal block copolymer. Furthermore, the thermoplastic-elastomer composition in any one of Claims 1-3 containing polyphenylene ether.