JP2003128871A - Thermoplastic polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic polymer composition which is excellent in heat resistance, reduced in unmelted gel and surface thickness, and gives a formed article, particularly, suitable for use in a high temperature atmosphere. SOLUTION: The thermoplastic polymer composition comprises; (a) 100 parts by mass of a block copolymer containing two or more polymer blocks A comprising a vinyl aromatic compound and one or more polymer block B comprising a conjugate diene compound, wherein 35% or more of carbon-carbon double bond derived from the conjugate diene compound is hydrogenated, the constitutional unit derived from the vinyl aromatic compound is contained in an amount of 5 to 75% by mass and the weight average molecular weight is 400,000 or more; (b) 50 to 300 parts by mass of a softening agent for non-aromatic-based rubber; and (c) 10 to 100 parts by weight of an olefin-based resin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic polymer composition. The thermoplastic polymer composition provided by the present invention is excellent in heat resistance, rubber elasticity, and oil absorption, and a molded product obtained from such a thermoplastic polymer composition has less unmelted gel and has a surface of a molded product. Since it is less sticky, it is useful as a member used in a high-temperature atmosphere such as automobile interior parts, household appliances parts, and industrial products.

[0002]

2. Description of the Related Art A typical example of a thermoplastic elastomer which is a vinyl aromatic compound-conjugated diene block copolymer or its hydrogenated product is a styrene-butadiene-styrene type block copolymer or its hydrogenated product, styrene. -A styrene-based thermoplastic elastomer such as isoprene-styrene type block copolymer or a hydrogenated product thereof. These styrene-based thermoplastic elastomers were appropriately combined with other polymers such as polyolefin resins such as polyethylene and polypropylene and non-aromatic rubber softeners typified by paraffin oil, depending on the application. Used as a resin composition. Such a resin composition does not require a vulcanization step, has rubber elasticity, is excellent in flexibility, has good moldability, and has characteristics such as being lightweight, and has problems such as recyclability and environmental pollution. From this viewpoint, in recent years, it has been used as a substitute for vulcanized rubber and polyvinyl chloride in a wide range of fields such as automobile parts, industrial products, sundries, and sports products.

[0003]

However, a molded article made of a conventionally known styrene-based thermoplastic elastomer or a resin composition containing the same is generally difficult to exhibit rubber elasticity under high temperature conditions. Further, it has a problem that the surface of the molded product is apt to become sticky, and its use is limited in applications where it is used in an atmosphere exposed to high temperatures, such as automobile interior parts, home electric appliance parts, and industrial products. . Thus, the object of the present invention is to obtain a molded product suitable for use even in an atmosphere exposed to high temperatures, with less unmelted gel and stickiness, rubber elasticity maintained even at high temperatures, and oil absorption. It is intended to provide a thermoplastic polymer composition containing a specific styrene-based thermoplastic elastomer having excellent properties.

[0004]

According to the present invention, the above-mentioned problems are (1) (a) two or more polymer blocks A composed of a vinyl aromatic compound and a polymer block B composed of a conjugated diene compound. Is a block copolymer containing one or more of 35% or more of the carbon-carbon double bond derived from the conjugated diene compound is hydrogenated, the content of the structural unit derived from the vinyl aromatic compound is 5 ~ 75% by mass,
And 100 parts by mass of a block copolymer having a weight average molecular weight of 400,000 or more, and (b) a softening agent for non-aromatic rubbers 50 to 50
300 parts by mass, (c) a thermoplastic polymer composition containing 10 to 100 parts by mass of an olefin resin, and (2)
This is solved by providing a molded article comprising the thermoplastic polymer composition of (1).

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The block copolymer used as the component (a) in the thermoplastic polymer composition of the present invention comprises two or more polymer blocks A made of a vinyl aromatic compound and one polymer block B made of a conjugated diene compound. It is a block copolymer containing more than one, 35% or more of the carbon-carbon double bond derived from the conjugated diene compound is hydrogenated, and the content of the constituent unit derived from the vinyl aromatic compound is 5 to 75. It is a block copolymer having a mass% and a weight average molecular weight of 400,000 or more.

Examples of the vinyl aromatic compound which constitutes the polymer block A in the block copolymer (a) include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene and p-methylstyrene. -T
-Butylstyrene, 2,4-dimethylstyrene, 2,
4,6-trimethylstyrene, p-methoxystyrene,
Examples thereof include vinyl naphthalene and vinyl anthracene. The polymer block A may be composed of one kind of these vinyl aromatic compounds, or may be composed of two or more kinds in combination. Among these,
The polymer block A is preferably composed of styrene and / or α-methylstyrene.

The content of the polymer block A in the block copolymer (a) is required to be within the range of 5 to 75% by mass based on the mass of the block copolymer (a). It is preferably within the range of 60% by mass.
When the content of the polymer block A in the block copolymer (a) is less than 5% by mass, the mechanical strength of the molded product obtained from the thermoplastic polymer composition becomes insufficient, while 75% by mass is added. If it exceeds, the flexibility of the molded product obtained from the thermoplastic polymer composition is impaired.

The polymer block B in the block copolymer (a) is composed of a conjugated diene compound, and 35% or more of carbon-carbon double bonds derived from the conjugated diene compound are hydrogenated. Examples of the conjugated diene compound constituting the polymer block B include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,
Examples include 3-pentadiene and 1,3-hexadiene. The polymer block B can be composed of one or more of these conjugated diene compounds. Among these, the polymer block B is preferably composed of butadiene, isoprene or a mixture of isoprene and butadiene, and particularly preferably composed of a mixture of isoprene and butadiene. When the polymer block B is composed of a mixture of isoprene and butadiene, the mixing ratio is not particularly limited.

The microstructure of the conjugated diene compound unit in the polymer block B is not particularly limited, but when butadiene is used alone, the content of 1,2-bond (vinyl bond) is usually 5 to 95. The content of 1,2-bonds is preferably in the range of 20 to 60 mol%, from the viewpoint of emphasizing rubber elasticity.
More preferably, it is in the range of 50 mol%. Further, when isoprene is used alone or when isoprene and butadiene are mixed and used, the total amount of 1,2-bonds and 3,4-bonds is usually in the range of 5 to 95 mol%. From the viewpoint of emphasizing rubber elasticity, the total amount of 1,2-bonds and 3,4-bonds (vinyl bonds) is preferably in the range of 5 to 40 mol%, and in the range of 5 to 20 mol%. It is more preferable.

In the polymer block B, 35% or more of the carbon-carbon double bond derived from the conjugated diene compound needs to be hydrogenated, preferably 50% or more is hydrogenated, and 75% is preferable. The above is more preferably hydrogenated, and particularly preferably 95% or more is hydrogenated. The hydrogenation rate of the carbon-carbon double bond derived from the conjugated diene compound in the polymer block B is 3
If it is less than 5%, the heat resistance and weather resistance of the molded article made of the thermoplastic polymer composition will be impaired.

The block copolymer (a) is required to have at least two polymer blocks A and at least one polymer block B from the viewpoint of heat resistance, rubber elasticity, mechanical strength and the like. Is. The binding mode of the polymer block A and the polymer block B may be linear, branched or any combination thereof, but when the polymer block A is represented by A and the polymer block B is represented by B , ABA, a triblock structure, (AB) n, (AB) n-
A, a multiblock copolymer represented by (where n represents an integer of 2 or more), and the like can be given. Among these, a triblock structure represented by ABA is
It is particularly preferable in terms of elasticity, mechanical strength, melt adhesion and handleability.

The weight average molecular weight of the block copolymer (a) used in the present invention must be 400,000 or more.
The upper limit of the weight average molecular weight of the block copolymer (a) is not particularly limited, but it is 10 from the viewpoint of moldability.
It is preferably 0,000 or less, more preferably 800,000 or less, and further preferably 500,000 or less. When the weight average molecular weight of the block copolymer (a) is less than 400,000, the heat resistance of the molded product obtained from the thermoplastic polymer composition becomes insufficient and the surface of the molded product becomes sticky. Cheap. The weight average molecular weight referred to in the present specification means gel permeation chromatography (GP).
C) A polystyrene-equivalent weight average molecular weight determined by measurement.

The block copolymer (a) has a functional group such as a carboxyl group, a hydroxyl group, an acid anhydride, an amino group or an epoxy group in the molecular chain or at the molecular end unless the purpose of the present invention is impaired. You may have.

The block copolymer (a) can be produced, for example, by the following known anionic polymerization method. That is, a vinyl aromatic compound and a conjugated diene are sequentially added in an inert organic solvent such as n-hexane or cyclohexane using an alkyl lithium compound such as n-butyl lithium, s-butyl lithium or t-butyl lithium as an initiator. Polymerization to form a polymer, the polymer obtained, according to a known method, in an inert organic solvent, platinum,
Noble metals such as palladium and rhodium are activated carbon, silica,
Hydrogenation in the presence of a hydrogenation catalyst such as a catalyst supported on a carrier such as alumina; Raney nickel; an organonickel compound, an organocobalt compound, or a Ziegler-based catalyst such as a composite catalyst of these compounds and another organometallic compound Thus, the block copolymer (a) can be produced. The hydrogenation rate of the polymer block B in the block copolymer (a) is determined by measuring the content of carbon-carbon double bonds derived from the conjugated diene compound in the polymer block by iodine value measurement, infrared spectrophotometry. Total, ¹ H-N
It can be measured by an MR spectrum or the like and can be obtained from the measured value.

The non-aromatic rubber softening agent used as the component (b) in the thermoplastic polymer composition of the present invention includes:
Any conventionally known non-aromatic softening agent for rubber can be used, and among them, non-aromatic mineral oil or liquid or low molecular weight synthetic softening agent is suitable. The non-aromatic softening agent for rubber (b) may be used alone or in combination of two or more kinds. Generally, a mineral oil-based softening agent for rubber called process oil or extender oil, which is used for softening, increasing volume, improving processability of rubber, is a combination of aromatic ring, naphthene ring and paraffin chain. A mixture in which the number of carbon atoms in the paraffin chain accounts for 50% or more of the total number of carbon atoms is called paraffin-based, and the one in which the carbon number of the naphthene ring is 30 to 45% is naphthene-based and the number of aromatic carbon atoms. A compound having more than 30% is called an aromatic system. In the present invention, among the above-mentioned process oils, as the component (b), paraffin-based process oil and naphthene-based process oil can be used. In addition to them, white oil, mineral oil, low molecular weight copolymer of ethylene and α-olefin, paraffin wax, liquid paraffin,
Conjugated diene-based polymers such as polybutene, liquid polybutadiene and liquid polyisoprene, or hydrogenated products thereof,
Liquid polyisobutylene or the like can be used. Among these, paraffinic process oil is preferable in the present invention.

The non-aromatic softening agent for rubber (b) is a rubber bullet.
From the viewpoint of sex, the kinematic viscosity at 40 ° C. is 30 to 400 m.
m^Two/ S is preferably in the range of 30 to 200
mm ^Two/ S is more preferable. Softener for non-aromatic rubber
Kinematic viscosity at 40 ° C of (b) is 30 mm^TwoLess than / s
Heat resistance, especially compression set at high temperature
The performance tends to be poor, while the kinematic viscosity at 40 ° C is 3
0 mm^Two/ S or more, the value of the kinematic viscosity is large
It is possible to improve heat resistance according to
0 mm^Two/ S or more is industrially available due to its manufacturing method.
Have difficulty. In addition, for non-aromatic rubber in the present specification
Kinematic viscosity of softening agent (b) at 40 ° C (mm^Two/ S)
Is a dynamic viscosity measured at a temperature of 40 ° C using a B-type viscometer.
Degree of softening agent (b) for non-aromatic rubber at 40 ° C
The value of the quotient divided by the density.

The amount of the non-aromatic softening agent for rubber (b) used is 50 based on 100 parts by mass of the block copolymer (a).
Is required to be within the range of 300 to 300 parts by mass, and 50
It is preferably in the range of 250 parts by mass. When the amount of the non-aromatic softening agent for rubber (b) used is less than 50 parts by mass relative to 100 parts by mass of the block copolymer (a),
Moldability of the thermoplastic polymer composition is impaired, while 30
When it exceeds 0 parts by mass, the heat resistance of the molded product obtained from the thermoplastic polymer composition is lowered, and the surface of the molded product tends to be sticky.

Examples of the olefin resin used as the component (c) in the thermoplastic polymer composition of the present invention include polyethylene resins such as low density polyethylene, high density polyethylene and linear low density polyethylene; homopolypropylene, Propylene resins such as block polypropylene and random polypropylene; ethylene-α-olefin copolymers, cyclic polyolefin polymers, polymethylpentene, polybutene-1 and the like. Among these, propylene-based resins such as homopolypropylene, block polypropylene and random polypropylene are particularly preferable. The olefin resin (c) may be used alone or in combination of two or more. Also,
As the olefin resin (c), it is also possible to use one having a functional group such as a carboxyl group, a hydroxyl group, an amino group or an epoxy group at the molecular end or side chain.

The amount of the olefin resin (c) used is required to be within the range of 10 to 100 parts by mass, and within the range of 15 to 80 parts by mass, relative to 100 parts by mass of the block copolymer (a). Is preferred. When the amount of the olefin resin (c) used is less than 10 parts by mass relative to 100 parts by mass of the block copolymer (a), the moldability of the thermoplastic polymer composition is impaired, while when it exceeds 100 parts by mass. ,
The flexibility and compression set at high temperature of the molded product obtained from the thermoplastic polymer composition are reduced.

The thermoplastic polymer composition of the present invention contains, in addition to the above-mentioned components (a) to (c), styrene resins such as polystyrene, AS resin, ABS resin and the like, if necessary; polyphenylene ether resins; Nylon 6, Nylon 66
Polyamide resin such as polyethylene terephthalate,
Polyester resins such as polybutylene terephthalate;
Polyurethane-based resins; polyoxymethylene-based resins such as polyoxymethylene homopolymers and polyoxymethylene-based copolymers; acrylic-based resins such as polymethylmethacrylate-based resins; ethylene-methacrylate copolymers, ethylene-acrylic acid copolymers, ethylene -Methacrylic acid copolymer, ethylene-unsaturated carboxylic acid copolymer or its ionomer, chlorosulfonated polyethylene,
Chlorinated polypropylene, ethylene-maleic anhydride copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-dimethylaminoethyl methacrylate copolymer,
Ethylene-propylene copolymer (EPM), ethylene
Propylene / non-conjugated diene terpolymer (EPDM),
It further contains another polymer such as a vinyl aromatic compound-conjugated diene block copolymer or a hydrogenated product thereof, which is different from the component (a) and has a weight average molecular weight of less than 400,000 and does not impair the gist of the present invention. You may have.

Further, the thermoplastic polymer composition of the present invention comprises
If necessary, carbon black, silica, carbon fiber,
Reinforcing agents such as glass fiber; fillers such as calcium carbonate, talc, clay, titanium oxide, barium sulfate, zinc white, mica; lubricants, light stabilizers, antioxidants, heat stabilizers, UV absorbers, pigments, difficult It may contain a flame retardant, an antistatic agent, an antiblocking agent, a release agent, a tackifier, a cross-linking agent, a cross-linking aid, a foaming agent, a perfume and the like.

The thermoplastic polymer composition of the present invention can be used after being subjected to a crosslinking treatment by further adding a crosslinking agent such as organic peroxide, if necessary. Also,
At that time, a crosslinking aid may be used in combination.

The thermoplastic polymer composition of the present invention is a method conventionally used in melt-kneading a thermoplastic polymer, for example, a single-screw extruder, a twin-screw extruder, a Banbury mixer, a Brabender, an open roll, It can be prepared by kneading each constituent in a molten state using a kneader such as a kneader. In addition, prior to kneading, a homogeneous thermoplastic polymer composition can be easily obtained by dry-blending each component in advance using a mixer such as a Henschel mixer or a tumbler. In addition,
The kneading is usually carried out at a temperature in the range of 170 to 250 ° C.

The thermoplastic polymer composition of the present invention can be formed into a sheet, a film or a tube by various known methods such as extrusion molding, injection molding, hollow molding, compression molding, calender molding and the like. It can be molded into a molded body of any shape such as a shape. Further, the thermoplastic polymer composition of the present invention can also be made into a composite molded article obtained by compounding with another material such as plastic or cloth by a two-color molding method, insert molding method, coextrusion or the like. .

The thermoplastic polymer composition of the present invention can be used as a raw material for various industrial products and industrial parts.
Specifically, automotive interior parts such as instrument panels, center panels, center console boxes, door trims, pillars, assist grips, handles, airbag covers, etc .; automotive exterior parts such as malls; remote control switches; various key tops for OA equipment. Home appliances such as TVs, stereos, and vacuum cleaners; underwater products such as underwater glasses and underwater camera covers; various cover parts; industries with various packings for sealing, waterproofing, soundproofing, vibration damping, etc. Parts: Automotive functional parts such as rack & pinion boots, suspension boots, constant velocity joint boots, etc .; electric and electronic parts such as wire coatings; footwear applications such as sports shoes, fashion sandals; belts, hoses, tubes;
It can be used for sports goods; building materials such as doors and window frames; various joints; valve parts; medical supplies such as gaskets for medical syringes.

In particular, the molded product obtained from the thermoplastic polymer composition of the present invention retains rubber elasticity even at high temperatures, has a small amount of unmelted gel, and is less sticky. It is used in an atmosphere exposed to high temperatures such as industrial products, and can be suitably used for applications requiring heat resistance.

[0027]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following examples and comparative examples,
The molded articles obtained from the thermoplastic polymer composition were evaluated for hardness, compression set, tackiness and unmelted gel by the methods described below.

Using a hardness press molding machine (50 tons), the thermoplastic polymer compositions obtained in the following Examples and Comparative Examples were treated at 220 ° C.
Then, after melt-molding using a sheet mold having a length of 150 mm × width of 150 mm × thickness of 2 mm, the sheet was taken out from the mold and immediately cooled by a water-cooling type cooling press to obtain a sheet. Using the obtained sheet, IRHD pocket hardness was measured according to JIS K-6253.

Using a compression set press machine (50 tons), the thermoplastic polymer compositions obtained in the following Examples and Comparative Examples were treated at 220 ° C.
At a diameter of 29.
After a cylindrical test piece of 0 mm × thickness 12.5 mm was melt-molded, the test piece was taken out of the mold and immediately cooled by a water-cooling type cooling press to obtain a test piece. Using the obtained test piece, the compression set when left for 22 hours under the conditions of a temperature of 120 ° C. and a compression deformation amount of 25% was measured according to JIS K-6262 and used as an index of rubber elasticity.

150 mm length × 150 mm width × thickness 2 used for measuring the stickiness hardness of the surface of the molded body
mm sheet is sandwiched between two sheets of paper (white recycled PPC paper; manufactured by Canon), and this is the same size polypropylene sheet (thickness 2 mm) 2
It is sandwiched by using a sheet, and a load of 100 g is placed on it, and 4
It was left for 1 week under 0 ° C atmosphere. After the load was released and the polypropylene sheet was removed, the degree of stain on the paper was visually observed and evaluated as follows. ◎: No stain by non-aromatic rubber softening agent ○: Slight stain by non-aromatic rubber softening agent △: A lot of non-aromatic rubber softening agent ×: Non-aromatic Significant contamination due to group-type rubber softeners

150 mm long × 150 mm wide × thickness 2 used for measuring the hardness of unmelted gel
With respect to the mm sheet, the presence or absence of unmelted gel was visually observed and evaluated as follows. ◎: Unmelted gel not observed ○: Unmelted gel is slightly seen △: Many unmelted gels ×: Unmelted gel is remarkable

The contents and abbreviations of the components used in the following examples are as follows. [1] Block Copolymer (a) [Production Method: Reference Example] Using s-butyllithium as a polymerization initiator, styrene and isoprene, butadiene, or a mixture of isoprene and butadiene are sequentially added in cyclohexane. And anionically polymerized to form an ABA-type triblock copolymer in which styrene polymer blocks are bound to both ends of a polymer block composed of a conjugated diene compound, or AB in which styrene polymer blocks are bound to one end.
Each type of diblock copolymer was prepared. The obtained triblock copolymer or diblock copolymer was added to 0.8 in a cyclohexane using a Ziegler-based catalyst.
A hydrogenation reaction was carried out at 75 ° C. in a hydrogen pressure atmosphere of Mpa to obtain block copolymers (a) -1 to (a) -5 having the physical properties shown in Table 1 below.

[0033]

[Table 1]

[2] Softener for non-aromatic rubber (b) (b) -1: "Diana Process P" manufactured by Idemitsu Kosan Co., Ltd.
W-32 "(paraffinic process oil; kinematic viscosity = 3)
0.85 mm ² / s (40 ° C.)) (b) -2: “Diana Process P” manufactured by Idemitsu Kosan Co., Ltd.
W-90 ”(paraffin-based process oil; kinematic viscosity = 9
5.54 mm ² / s (40 ° C.)) (b) -3: “Diana Process P” manufactured by Idemitsu Kosan Co., Ltd.
W-380 "(paraffinic process oil; kinematic viscosity =
381.6 mm ² / s (40 ° C))

[3] Olefin Resin (c) (c) -1: "J106" manufactured by Grand Polymer Co., Ltd.
W "(Homopolypropylene) MFR: 15g / 10min (2
30 ° C-2.16 Kg), elongation at break: 200% Rockwell hardness: 100, tensile yield strength: 38MP
a Bending initial elastic modulus: 1600 MPa

Examples 1 to 6 and Comparative Examples 1 to 8 The above block copolymer (a), the non-aromatic softening agent for rubber (b) and the olefin resin (c) are shown in Table 2 and Table 2. Three
Dry-blended in advance with the blending amount shown in, and the resulting mixture was melt-kneaded using a twin-screw extruder at a cylinder temperature of 230 ° C. and a screw rotation speed of 200 rpm, and then extruded into a strand shape and cut to obtain a thermoplastic resin. Pellets of the polymer composition were produced. Using the obtained pellets, a sheet and a test piece having a predetermined shape were prepared by the method described above, and various physical properties were evaluated by the method described above. The results are shown in Tables 2 and 3.
Are also shown.

[0037]

[Table 2]

[0038]

[Table 3]

From the results shown in Table 2, in Examples 1 to 6, the block copolymer (a), the non-aromatic softening agent for rubber (b) and the olefin resin (c) were in the ranges specified in the present invention. By satisfying all of the above, it is possible to obtain a molded product which is excellent in heat resistance, particularly compression set at high temperature (120 ° C.), has good stickiness on the surface of the molded product, and has no unmelted gel. I understand.

On the other hand, in Comparative Examples 1 to 3, since the weight average molecular weight of the block copolymer (a) was less than the range specified in the present invention, the obtained molded product had a sticky surface and unmelted gel. The results are inferior to those of Examples 1 to 6 in terms of amount. In Comparative Example 4, the block copolymer (a)
The weight average molecular weight of does not satisfy the range specified in the present invention,
Moreover, since the content (styrene content) of the polymer block A constituting the block copolymer (a) exceeds the range specified in the present invention, the obtained molded article has extremely high hardness, and The values of compression set, stickiness and the amount of unmelted gel at high temperature (120 ° C.) are also inferior to those of the examples.

In Comparative Example 5, although the weight average molecular weight of the block copolymer (a) satisfies the range specified in the present invention, the hydrogenation rate is less than the value specified in the present invention, so that the obtained molding is obtained. The results are inferior to the examples regarding the value of compression set, stickiness and the amount of unmelted gel at a high temperature (120 ° C.) of the body. In Comparative Example 6, since the diblock copolymer was used, the compression set of the obtained molded article at a high temperature (120 ° C.) was large, and the stickiness and the amount of unmelted gel were also higher than those of the Examples. Results inferior. In Comparative Example 7, the compounding amount of the non-aromatic rubber softening agent (b) exceeds the range specified in the present invention, so the compression set value and stickiness at high temperature (120 ° C.) of the obtained molded article are high. The results are inferior to the examples in terms of the properties and the amount of unmelted gel. In Comparative Example 8, since the blending amount of the olefin resin (c) exceeds the range specified in the present invention, the obtained molded product has high hardness,
In addition, the compression set value and the amount of unmelted gel at a high temperature (120 ° C.) of the molded body are inferior to those of the examples.

[0042]

According to the present invention, there is little unmelted gel and stickiness, and it is possible to obtain a molded product suitable for use especially in an atmosphere exposed to high temperature, and rubber elasticity is maintained even at high temperature. A thermoplastic polymer composition having excellent oil absorption is also provided.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F071 AA12X AA20 AA22X AA71                       AA75 AF13 AF25 AF55 AH07                       AH12 AH17 BA01 BB03 BC01                 4J002 AE05X BB023 BB053 BB113                       BB123 BB173 BK003 BP01W                       FD010 FD140 GM00 GN00                       GQ00

Claims (4)

[Claims] 1. A block copolymer containing (a) two or more polymer blocks A made of a vinyl aromatic compound and one or more polymer blocks B made of a conjugated diene compound, wherein the conjugated diene compound is a block copolymer. 35% or more of the carbon-carbon double bond derived from is hydrogenated, the content of the structural unit derived from the vinyl aromatic compound is 5 to 75% by mass,
And 100 parts by mass of a block copolymer having a weight average molecular weight of 400,000 or more, and (b) a softening agent for non-aromatic rubbers 50 to 50
300 parts by mass and (c) olefin resin 10 to 10
A thermoplastic polymer composition containing 0 part by mass. 2. The thermoplastic polymer composition according to claim 1, wherein the polymer block B comprising the conjugated diene compound of the block copolymer (a) comprises butadiene, isoprene, or a mixture of isoprene and butadiene. 3. The kinematic viscosity at 40 ° C. is 30 to 400 m.
The thermoplastic polymer composition according to claim 1, wherein a non-aromatic softening agent for rubber is used in the range of m ² / s. 4. A molded product comprising the thermoplastic polymer composition according to claim 1.