JP2010275459A - Elastomer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastomer composition wherein the loss tangent (tan&delta;) and hardness are enhanced within a preferred range of hardness as an elastomer without impairing mechanical properties such as fracture elongation and fracture strength. <P>SOLUTION: The elastomer composition includes (A) 100 pts.mass of a hydrogenated block copolymer which is obtained by hydrogenating a block copolymer consisting of at least one polymer block mainly containing a vinyl aromatic compound and at least one polymer block mainly containing a conjugated diene compound; (B) 1-500 pts.mass of an oil as a softening agent; and (C) 0.1-50 pts.mass of a polyolefin resin as a processing aid; as well as (D) at least one selected from an aromatic hydrocarbon resin, a linear aliphatic hydrocarbon resin, a chromane-indene resin, and a phenol-acetylene resin, having weight average molecular weight in the range of 100-5,000; wherein the Asker-C hardness is 10-70 degree. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an elastomer composition. More specifically, the present invention relates to an elastomer composition having both loss tangent (tan δ) and hardness increased within a suitable hardness range as an elastomer without impairing physical properties such as breaking elongation and breaking strength. is there.

Thermoplastic elastomers have excellent flexibility and moldability, so they can be used in automobile interior and exterior materials, home appliance parts, electronic equipment, medical equipment, sports equipment, stationery, toys, packaging materials, gaskets and packing, and adhesives. It is used in a wide range of fields.
As this thermoplastic elastomer, for example, as disclosed in Patent Documents 1 to 4, a so-called MNCS (Micro Network Controlled Structure) material composed of a styrenic thermoplastic elastomer, oil, polyolefin, polyphenylene ether, or the like has been frequently used in recent years. It has come to be.
By the way, for elastomer compositions used for vibration absorbing materials and shock absorbing materials, the viscoelastic properties, particularly loss tangent (tan δ), are improved without impairing the performance as an elastomer, and vibration energy and shock energy are absorbed. It is required to improve the performance.
However, in reality, an effective method for increasing tan δ without impairing the performance as an elastomer has not been found so far.

JP 2000-44691 A JP 2000-169666 A JP 2002-226666 A JP 2004-115753 A

In Patent Documents 1 to 4, there is no mention of the addition of a resin component for increasing tan δ while maintaining the performance as an elastomer in the MNCS material.
The present invention has been made under such circumstances, and the loss tangent (tan δ) and the hardness are both in the preferred hardness range as an elastomer without impairing physical properties such as elongation at break and strength at break. It is an object to provide an enhanced elastomer composition.

As a result of intensive research to develop an elastomer composition having the above-mentioned preferable properties, the present inventor can achieve the object by adding a specific resin to the MNCS material having the predetermined hardness described above. I found.
The present invention has been completed based on such findings.

That is, the present invention
[1] Water obtained by hydrogenating at least one of (A) a polymer block mainly composed of a vinyl aromatic compound and at least one polymer block mainly composed of a conjugated diene compound While containing 1 to 500 parts by weight of (B) an oil as a softening agent and (C) 0.1 to 50 parts by weight of a polyolefin-based resin as a processing aid, with respect to 100 parts by weight of the additive block copolymer And (D) at least one selected from the group consisting of aromatic hydrocarbon resins, chain aliphatic hydrocarbon resins, coumarone-indene resins and phenol-acetylene resins having a weight average molecular weight in the range of 100 to 5,000. And an elastomer composition characterized by having an Asuka C hardness of 10 to 70 degrees,
[2] The hydrogenated block copolymer of component (A) is a polystyrene-hydrogenated polybutadiene-polystyrene triblock copolymer and / or a polystyrene-hydrogenated polyisoprene-polystyrene triblock copolymer. [1] an elastomer composition,
[3] The elastomer composition according to the above [1] or [2], wherein the oil as the softener of the component (B) is a non-aromatic oil,
[4] The elastomer composition according to any one of [1] to [3], wherein the content of the component (D) is 10 to 250 parts by mass with respect to 100 parts by mass of the component (A).
[5] Further, (E) the elastomer composition according to any one of [1] to [4] above containing polyphenylene ether, and [6] the polyolefin resin of component (C) is a polypropylene resin. 1] to [5] any elastomer composition,
Is to provide.

  According to the present invention, by adding a specific resin to an MNCS material having a predetermined hardness, a loss tangent (within a suitable hardness range as an elastomer is obtained without impairing physical properties such as elongation at break and strength at break. It is possible to provide an elastomer composition having both tasδ) and hardness increased.

  The elastomer composition of the present invention comprises (B) 1 to 500 parts by mass of an oil as a softening agent and (C) with respect to 100 parts by mass of the hydrogenated block copolymer as component (A) shown below. In addition to 0.1 to 50 parts by mass of a polyolefin resin as a processing aid, (D) at least one selected from the following specific resins having a weight average molecular weight in the range of 100 to 5000 And the Asuka C hardness is 10 to 70 degrees.

[(A) Hydrogenated block copolymer]
In the elastomer composition of the present invention, as the hydrogenated block copolymer used as the component (A), for example, a block copolymer of polybutadiene and polystyrene, and a block copolymer of polyisoprene and polystyrene, or Obtained by hydrogenating a block copolymer of polybutadiene or ethylene-butadiene random copolymer and polystyrene, for example, diblock copolymer of crystalline polyethylene and polystyrene, styrene-ethylene / butylene-styrene triblock Preferred examples of such a copolymer (SEBS) and styrene-ethylene / propylene-styrene triblock copolymer (SEPS) include SEBS and SEPS.
As the component (A), a block copolymer having at least two polymer blocks mainly composed of vinyl aromatic compounds and at least one polymer block mainly composed of conjugated diene compounds (for example, styrene-butadiene- A hydrogenated block copolymer obtained by hydrogenating a styrene block copolymer, a styrene-isoprene-styrene block copolymer, or the like) is more preferable. The number average molecular weight of these hydrogenated block copolymers is preferably 60,000 or more, and when this number average molecular weight is 60,000 or more, bleeding of the softening agent (B) described later is suppressed. The compression set is small. The upper limit of the number average molecular weight is not particularly limited, but is usually about 400,000.
In addition, the said number average molecular weight is the value of standard polystyrene conversion measured by the gel permeation chromatograph (GPC) method.

  The content of the amorphous styrene block in the hydrogenated block copolymer is 10 to 70% by mass, preferably 15 to 60% by mass. The glass transition temperature (Tg) of the amorphous styrene block portion is 60 ° C. or higher, preferably 80 ° C. or higher. Also, the polymer at the portion connecting the amorphous styrene blocks at both ends is preferably an amorphous one. For example, an ethylene-butylene copolymer, an ethylene-propylene copolymer, a butadiene polymer or an isoprene is used. Examples thereof include a hydrogenated product of a polymer, and may be a block or random copolymer of these. In addition, although the hydrogenated block copolymer of the said (A) component is mainly used independently, you may blend and use 2 or more types.

[(B) Oil as softener]
In the elastomer composition of the present invention, oil as a softening agent is used as the component (B). The oil as the softening agent for the component (B) is contained for the purpose of reducing the hardness of the hydrogenated block copolymer of the component (A). The oil as the softening agent for component (B) is preferably a non-aromatic oil from the viewpoint of performance. The non-aromatic oil preferably has a kinematic viscosity at 40 ° C. of 100 mm ² / s or more from the viewpoint of suppressing weight loss and bleed due to volatilization. more preferably ~10000mm is ² / s, particularly 200~5000mm ² / s are preferred. Further, the molecular weight is preferably a number average molecular weight of less than 20,000, particularly 10,000 or less, especially 5,000 or less. Both hydrophilic and hydrophobic oils can be used. The oil as the softening agent having such properties can be appropriately selected from various non-aromatic oils such as mineral oils, vegetable oils, and synthetics. Here, process oils such as naphthenic and paraffinic are exemplified as mineral oils, and as a vegetable oil, castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, Examples include wax, pine oil, and olive oil. Among them, in particular, one or more selected from mineral oil-based paraffinic oil, naphthenic oil, or synthetic polyisobutylene-based oil, the number average molecular weight of which is 450 to 5,000 Is preferred.

  The oil of the said (B) component may be used individually by 1 type, and 2 or more types may be mixed and used if mutual compatibility is favorable. Although content of these oils is 1-500 mass parts with respect to 100 mass parts of said (A) component, Preferably it is 20-400 mass parts, Most preferably, it is 100-300 mass parts. When the content is 1 part by mass or more, sufficient hardness reduction can be achieved, and sufficient flexibility of the elastomer composition can be obtained. On the other hand, when the amount is 500 parts by mass or less, the oil does not bleed and sufficient mechanical strength of the elastomer composition can be obtained. The content of this oil is appropriately selected within the above range depending on the molecular weight of the hydrogenated block copolymer of component (A) and the type of other components added to the hydrogenated block copolymer. Is preferred.

[(C) Polyolefin resin as processing aid]
In the elastomer composition of the present invention, a polyolefin resin as a processing aid is used as the component (C). The main component of the (C) component polyolefin-based resin is to improve the processability of the elastomer composition, but it also has the effect of improving the heat resistance of the composition.
The polyolefin resin of the component (C) is preferably crystalline from the viewpoint of performance, and more preferably a crystalline polypropylene resin. Examples of the crystalline polypropylene-based resin include isotactic polypropylene, a copolymer of propylene and a small amount of other α-olefin (for example, propylene-ethylene copolymer, propylene / 4-methyl-1-pentene copolymer). ) And the like. When a copolymer of isotactic polypropylene is used as the crystalline polypropylene resin, those having an MFR (JIS K7210) in the range of 0.1 to 100 g / 10 min, particularly 0.5 to 50 g / 10 min are preferable. Can be used. Although content of the said (C) component is 0.1-50 mass parts with respect to 100 mass parts of said (A) component, Preferably it is 0.1-30 mass parts, Most preferably, it is 5-20 mass parts. It is. When the content is 0.1 parts by mass or more, the processability and heat resistance characteristics of the elastomer composition can be improved. On the other hand, when the content is 50 parts by mass or less, the hardness of the obtained elastomer composition becomes too high. There is nothing.

In the elastomer composition, in order to improve the processability and heat resistance of the composition, a polystyrene resin can be used in combination with the component (C). As the polystyrene-based resin, those obtained by either a radical polymerization method or an ionic polymerization method can be suitably used as long as they are obtained by a known production method. The number average molecular weight of the polystyrene resin is preferably selected from the range of 5,000 to 500,000, more preferably 10,000 to 200,000, and the molecular weight distribution [weight average molecular weight (Mw) and number average molecular weight (Mn )) (Mw / Mn)] is preferably 5 or less. Examples of the polystyrene resin include polystyrene, styrene-butadiene block copolymer having a styrene unit content of 60% by mass or more, rubber-reinforced polystyrene, poly α-methylstyrene, polypt-butylstyrene, and the like. These may be used alone or in combination of two or more. Furthermore, a copolymer obtained by polymerizing a mixture of monomers constituting these polymers can also be used. In the elastomer composition of the present invention, when a polystyrene resin is used in combination with the component (C), the hardness of the resulting composition tends to be higher than when no polystyrene resin is used. Therefore, the hardness of the elastomer composition obtained can also be adjusted by selecting these compounding ratios. In this case, the ratio of polyolefin resin / polystyrene resin is preferably selected from the range of 95/5 to 5/95 (mass ratio).
In addition, said weight average molecular weight Mw and number average molecular weight Mn are the values of standard polystyrene conversion measured by GPC method.

[(D) Resin]
In the elastomer composition of the present invention, as the component (D), an aromatic hydrocarbon resin, a chain aliphatic hydrocarbon resin, a coumarone-indene resin, a phenol, At least one selected from acetylene resins is used.
If the weight average molecular weight of each resin is within the above range, the object of the present invention can be achieved effectively. A preferred weight average molecular weight is in the range of 500-3000. In addition, the said weight average molecular weight is the value of standard polystyrene conversion measured by GPC method.

Examples of the aromatic hydrocarbon resin include C ₉ synthetic petroleum resin which is a copolymer of styrene, indene, α-methylstyrene and methylindene for C _{8 to} C ₁₀ fractions.
The chain aliphatic hydrocarbon resin is obtained, for example, by homopolymerizing or copolymerizing at least one selected from α-olefins and diene compounds, and has a weight average molecular weight of 100 to 5000. About a resin is used.
The coumarone / indene resin is a resin obtained by polymerizing coumarone, indene, styrene, etc. in coal tar, and the phenol-acetylene resin usually contains pt-butylphenol and acetylene, zinc naphthenate, etc. Is a resin obtained by condensing as a catalyst.

In the present invention, when the component (D) is added to an elastomer material containing the component (A), the component (B), the component (C), and an optional component described later, Both the hardness and tan δ can be increased without impairing the breaking elongation and breaking strength. In addition, the higher the tan δ, the better the absorbability of impact energy and vibration energy. Therefore, the obtained elastomer composition can provide an excellent shock absorbing material and vibration damping material.
In the elastomer composition of this invention, it is preferable that content of the said (D) component is 10-250 mass parts with respect to 100 mass parts of said (A) component. If this content is in the above range, the elastomer composition can maintain the Asuka C hardness described later in the range of 10 to 70 degrees, and has high hardness and tan δ without impairing the breaking elongation and breaking strength. It will be a thing. More preferable content of the said (D) component is 20-100 mass parts, and still more preferable content is 30-80 mass parts.

[Optional ingredients]
If desired, the elastomer composition of the present invention may contain polyphenylene ether as the component (E) for the purpose of improving the compression set of the composition.
((E) polyphenylene ether)
In the present invention, the polyphenylene ether used as the component (E) may be a homopolymer, a copolymer, or an alloy with polystyrene, polypropylene, or polyamide.
Examples of the homopolymer include poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), and poly (2,6-diphenyl-1). , 4-phenylene ether), poly (2-methyl-6-phenyl-1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether) and the like. Examples thereof include polyphenylene ether copolymers such as copolymers of 2,6-dimethylphenol and monovalent phenols (for example, 2,3,6-trimethylphenol and 2-methyl-6-butylphenol). .
The polyphenylene ether of component (E) is commercially available. For example, “Zylon (registered trademark)” series manufactured by Asahi Kasei Chemicals, “Noryl (registered trademark)” series manufactured by GE Plastics, Inc. can be used. it can.
In the elastomer composition of this invention, it is preferable that content of the polyphenylene ether of the said (E) component is 10-250 mass parts with respect to 100 mass parts of above-mentioned (A) components.

(filler)
If necessary, the elastomer composition of the present invention may contain a filler. Examples of the filler include clay, inorganic filler such as clay, diatomaceous earth, silica, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxide, mica, graphite, aluminum hydroxide, various metal powders, Wood chips, glass powder, ceramic powder, granular or powdered solid filler such as granular or powdered polymer, other various natural or artificial short fibers, long fibers (eg, straw, hair, glass fiber, metal fiber, various other Or other polymer fibers).
Moreover, weight reduction can be achieved by including a hollow filler, for example, an organic hollow filler made of an inorganic hollow filler such as a glass balloon or a silica balloon, a polyvinylidene fluoride, a polyvinylidene fluoride copolymer, or the like. Furthermore, in order to improve various physical properties such as weight reduction, it is possible to mix various foaming agents, and it is also possible to mix gas mechanically during mixing.

(Other additives)
Other additives include flame retardants, antibacterial agents, hindered amine light stabilizers, UV absorbers, antioxidants, colorants, silicone oils, silicone polymers, and highblurs (trade name: Kuraray, vinyl) -Other thermoplastic elastomers such as a block copolymer in which polystyrene blocks are linked to both ends of a polyisoprene block), Norex (trade name: manufactured by ZEON Corporation, polynorbornene obtained by ring-opening polymerization of norbornene) or Resins and the like can be contained.

[Properties of elastomer composition]
In the elastomer composition of the present invention, the polymeric organic material constituting the same preferably has a three-dimensional continuous network skeleton structure, and the formed three-dimensional continuous network skeleton structure has an average diameter of the skeleton. The average diameter of the cells (mesh) is preferably 500 μm or less, more preferably 300 μm or less, and the volume fraction of the polymer organic material is expressed as [volume of the polymer organic material] / (Volume of polymer organic material + volume of softener)] × 100 (%), the volume fraction of the polymer organic material is preferably 50% or less, more preferably 33% or less. Is desirable.
Moreover, the Asuka C hardness of the said elastomer composition needs to exist in the range of 10-70 degree | times. If the Asuka C hardness is less than 10 degrees, the mechanical strength is low and sufficient performance is not exhibited. On the other hand, if it exceeds 70 degrees, the properties as an elastomer are lost and sufficient performance is not exhibited. The preferred Asuka C hardness is 10 to 60 degrees, more preferably 10 to 50 degrees.
The Asuka C hardness is a value measured using an ASK-c hardness meter.

[Production of Elastomer Composition]
The method for producing the elastomer composition of the present invention is not particularly limited, and a known method can be applied. For example, after dry blending the above components (A) to (D) and optionally used (E) components and various additives, a heat kneader, such as a single screw extruder, twin screw extruder, roll, Banbury mixer, etc. , Melt kneading using a plastic bender, kneader, high shear mixer, etc., and if necessary, adding a crosslinking agent such as organic peroxide, a crosslinking aid, etc., or mixing these necessary components simultaneously. It can be easily manufactured by heat-melting and kneading. In addition, an elastomer composition in which a polymer organic material and a softening agent are kneaded is prepared in advance, and this composition is further mixed with one or more polymer organic materials of the same type or different types from those used here. Can also be manufactured. Furthermore, the elastomer composition of the present invention can be cross-linked by adding a cross-linking agent such as an organic peroxide, a cross-linking aid or the like.

The elastomer composition of the present invention is molded into a desired shape using various conventionally known molding methods such as injection molding, extrusion molding, blow molding, hollow molding, compression molding, calendar molding, etc. It can be used for various purposes.
The elastomer composition of the present invention has a good breaking elongation and breaking strength, has a good flexibility and a high tan δ, and is therefore excellent in vibration energy and impact energy absorption, and is a vibration damping material. And is suitably used for shock absorbing materials.
Also, a wide range of parts such as automotive interior materials, exterior materials, home appliances, audio equipment, OA equipment, various switches, medical equipment, optical cables, sports equipment, shoes, building materials, various packings, sealing materials, cushioning materials, toys, stationery, etc. Can be used in the field.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, about the physical property of the elastomer composition obtained in each case, it evaluated in accordance with the method shown below.
(1) Asuka C hardness A test piece was prepared based on JIS K6253, and the Asuka C hardness at 25 ° C. was measured with an Asuka C hardness meter [manufactured by Kobunshi Keiki Co., Ltd., model name “ASK-c hardness meter”].
(2) Tensile test About the sheet punched into DIN3 dumbbell shape, using a tensile tester [manufactured by ORIENTEC, model name “Tensilon RTC-1225A”], in accordance with JIS K 6251, test temperature 25 ° C., tensile speed 200 mm A tensile test was performed under the conditions of / min, and the breaking strength Tb, breaking elongation Eb, and 300% elongation stress _M300 were measured.
(3) Dynamic viscoelastic properties A sheet having a length of 40 mm, a width of 5 mm, and a thickness of 2 mm was prepared and used as a sample. Using this sample, a viscoelastic spectrometer “RDAIII” (manufactured by Rheometric Scientific F.E. Co., Ltd.) was used, and the measurement conditions were a distance between chucks of 2 mm, a dynamic strain of 1%, a frequency of 1 Hz, and a measurement temperature of 25 ° C. Then, dynamic viscoelasticity measurement was performed and loss tangent (tan δ) was measured.

Examples 1-4
100 parts by weight of SEPS with a weight average molecular weight of 300,000 and a polystyrene block content of 30% by mass (trade name “Septon 4077” manufactured by Kuraray Co., Ltd.), paraffinic oil having a kinematic viscosity at 40 ° C. of 380 mm ² / s [Idemitsu Kosan Product name “Diana Process Oil PW380”, number average molecular weight 750] 263 parts by mass, polypropylene [manufactured by Nippon Novatec, trade name “BC05B”, MFR 50 g / 10 min] 5 parts by mass, and shown in Table 1 (D ) 20 parts by mass of various resin components are mixed in advance, and then a twin-screw kneader (manufactured by Toshiba Machine Co., Ltd., TEM58BS type, screw length / cylinder diameter = 62.5, ratio of kneading zone length to screw length = 62 %) At 180 ° C., and cut with a cutter while extruding into a strand shape. LET) was obtained.
Using this pellet, each test piece for measuring physical properties was prepared, and Aska C hardness, Eb, Tb, M ₃₀₀ and tan δ were measured. The results are shown in Table 1.

Comparative Example 1
In Examples 1 to 4, an elastomer composition (pellet) was obtained in the same manner as in Examples 1 to 4 except that the component resin (D) was not used.
Using this pellet, each test piece for measuring physical properties was prepared, and Aska C hardness, Eb, Tb, M ₃₀₀ and tan δ were measured. The results are shown in Table 1.

[note]
The trade names and company names of the component resin (D) in Table 1 are as follows.
Aromatic hydrocarbon resin: “Nisseki Neopolymer” manufactured by Nippon Petrochemical Co., Ltd.
Chain aliphatic hydrocarbon resin: “STRUKTOL 40MS” manufactured by schill & SEILacher
Coumarone Indene Resin: “Powder Coumarone Resin” manufactured by Morimura Sangyo Co., Ltd.
Phenol-acetylene resin: “KORESIN” manufactured by BASF

In Table 1, the index of each characteristic is a value based on 100 for Comparative Example 1 in which component (D) is not blended.
As can be seen from Table 1, in the SEPS system, when each resin of the component (D) is blended, the Asuka C hardness and tan δ can be increased without impairing the physical properties of Eb and Tb.

Examples 5-8
SEBS having a weight average molecular weight of 60,000 and a polystyrene block content of 30% by mass [trade name “Tuftec H1272” manufactured by Asahi Kasei Chemicals Co., Ltd.] 100 parts by mass, paraffinic oil having a kinematic viscosity at 40 ° C. of 380 mm ² / s [Idemitsu Kosan Product name “Diana Process Oil PW380”, number average molecular weight 750] 163 parts by mass, polypropylene [manufactured by Nippon Polyolefin Co., Ltd., trade name “JP0M1600”, MFR 11 g / 10 min] 12 parts by mass, and shown in Table 2 ( D) 20 parts by mass of each resin of the component are mixed in advance, and then a twin-screw kneader (manufactured by Toshiba Machine Co., TEM58BS type, screw total length / cylinder diameter = 62.5, ratio of kneading zone length to screw total length = 62 %) At 180 ° C., cut with a cutter while extruding into a strand, It was obtained Tomah composition (pellets).
Using this pellet, each test piece for measuring physical properties was prepared, and Aska C hardness, Eb, Tb, M ₃₀₀ and tan δ were measured. The results are shown in Table 2.

Comparative Example 2
In Examples 5 to 8, an elastomer composition (pellet) was obtained in the same manner as in Examples 5 to 8, except that the component resin (D) was not used.
Using this pellet, each test piece for measuring physical properties was prepared, and Aska C hardness, Eb, Tb, M ₃₀₀ and tan δ were measured. The results are shown in Table 2.

[note]
The trade names and company names of component resin (D) in Table 2 are the same as the footnotes in Table 1.
In Table 2, the index of each characteristic is a value in which the value of Comparative Example 2 in which (D) component resin is not blended is 100.
As can be seen from Table 2, also in the SEBS system, when each resin of the component (D) is blended as in the SEPS system, the Asuka C hardness and tan δ are increased without impairing the physical properties of Eb and Tb. Can do.

The elastomer composition of the present invention has a good breaking elongation and breaking strength, has a good flexibility and a high tan δ, and is therefore excellent in vibration energy and impact energy absorption, and is a vibration damping material. And is suitably used for shock absorbing materials.
In addition, a wide range of parts such as automobile interior materials, exterior materials, home appliances, audio equipment, OA equipment, various switches, medical equipment, optical cables, sports equipment, shoes, building materials, various packing, sealing materials, cushioning materials, toys, stationery, etc. Can be used in the field.

Claims (6)

  (A) A hydrogenated block copolymer obtained by hydrogenating a block copolymer comprising at least one polymer block mainly composed of a vinyl aromatic compound and at least one polymer block mainly composed of a conjugated diene compound. (B) 1 to 500 parts by mass of an oil as a softening agent and (C) 0.1 to 50 parts by mass of a polyolefin-based resin as a processing aid with respect to 100 parts by mass of the polymer, D) At least one selected from the group consisting of aromatic hydrocarbon resins, chain aliphatic hydrocarbon resins, coumarone / indene resins, and phenol / acetylene resins having a weight average molecular weight in the range of 100 to 5,000. An elastomer composition comprising an Asuka C hardness of 10 to 70 degrees.   The hydrogenated block copolymer of component (A) is a polystyrene-hydrogenated polybutadiene-polystyrene triblock copolymer and / or a polystyrene-hydrogenated polyisoprene-polystyrene triblock copolymer. The elastomer composition as described.   The elastomer composition according to claim 1 or 2, wherein the oil as the softening agent for component (B) is a non-aromatic oil.   (D) The elastomer composition in any one of Claims 1-3 whose content of a component is 10-250 mass parts with respect to 100 mass parts of (A) component.   Furthermore, the elastomer composition in any one of Claims 1-4 containing (E) polyphenylene ether.   The elastomer composition according to any one of claims 1 to 5, wherein the polyolefin resin of component (C) is a polypropylene resin.