JP2002327098A - Thermoplastic elastomer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition having excellent moldability in extrusion molding, injection molding and blow molding, giving a molding with good mechanical properties, not thermally deformed at a high temperature of >=150 deg.C and tolerable for continuous use. SOLUTION: This thermoplastic elastomer composition comprises (a) 100 pts.wt. of at least a kind of elastomer selected from the group consisting of a block copolymer composed of at least two polymer blocks A comprising mainly aromatic vinyl compound and at least one polymer block B comprising mainly conjugated diene compound, a hydrogenated block copolymer thereof and an olefinic copolymer rubber, (b) 5 to 500 pts.wt. of a polypropylene-based resin and (c) 5 to 450 pts.wt. of a polymethylpentene-based resin, where the weight ratio (b)/(c) is 0.2 to 6.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic elastomer composition and, more particularly, to a thermoplastic elastomer composition having excellent heat deformation resistance, extrudability, injection moldability, blow moldability, and the like.

[0002]

2. Description of the Related Art In recent years, thermoplastic elastomers, which are soft materials having rubber elasticity, do not require a vulcanization step, and are moldable and recyclable similar to thermoplastic resins, have been used for automobile parts, home electric parts, It is widely used in the fields of wire coating, medical parts, footwear, sundries and the like.

[0003] Among thermoplastic elastomers, polystyrene-based thermoplastic elastomers such as styrene-butadiene block polymer (SBS) and styrene-isoprene block polymer (SIS), which are block copolymers of an aromatic vinyl compound and a conjugated diene compound, include: The thermoplastic elastomer composition which is rich in flexibility, has good rubber elasticity at room temperature, and has excellent processability is widely used as a substitute for vulcanized rubber.

Further, elastomer compositions obtained by hydrogenating an intramolecular double bond of a block copolymer of styrene and a conjugated diene in these elastomers are elastomers having improved heat aging resistance (thermal stability) and weather resistance. As is widely used.

Further, thermoplastic elastomer compositions using these hydrogenated block copolymers still have rubber-like properties, for example, oil resistance, deformation under heating and compression (compression set).
In order to improve this point, there has been proposed a crosslinked product obtained by crosslinking a composition containing a hydrogenated derivative of the block copolymer (for example, Japanese Patent Application Laid-Open JP-A-59-6236, JP-A-63-6
No. 57662, Japanese Patent Publication No. 3-49927, Japanese Patent Publication No. 3-11291 and Japanese Patent Publication No. 6-13628).

However, even these crosslinked thermoplastic elastomers do not exhibit mechanical properties at high temperatures, particularly at 150 ° C. or higher, and most of them have a continuous use temperature of about 120 ° C. or lower. In applications where it is used as a material for components that are exposed to high temperatures, such as peripheral components, its use has been problematic.

[0007]

SUMMARY OF THE INVENTION In view of the above problems, the present invention has good mechanical properties, does not thermally deform at a high temperature of 150 ° C. or higher, can be used continuously, and has good extrusion moldability.
An object of the present invention is to provide a thermoplastic elastomer composition having excellent injection moldability and blow moldability.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, by blending a thermoplastic elastomer with a specific ratio of a polypropylene resin and a polymethylpentene resin, The inventors have found that a thermoplastic elastomer having excellent heat resistance can be obtained, and have completed the present invention.

That is, the first invention of the present invention provides (a)
(A-1) a block copolymer comprising at least two polymer blocks A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound, (a-2) ) 100% by weight of at least one elastomer selected from the group consisting of a hydrogenated block copolymer obtained by hydrogenating (a-1) and (a-3) an olefin copolymer rubber, and (b) polypropylene. A composition comprising 5 to 500 parts by weight of a base resin and (c) 5 to 450 parts by weight of a polymethylpentene resin,
A thermoplastic elastomer composition, wherein the weight ratio of (b) / (c) is from 0.2 to 6.5.

[0010] The second invention of the present invention further comprises (d) 1 to 250 parts by weight of a polyethylene resin.
The thermoplastic elastomer composition according to the first aspect, wherein the weight ratio of (c) is from 0.2 to 4.

A third invention of the present invention is the thermoplastic elastomer according to the first or second invention, further comprising (e) 0.01 to 3.5 parts by weight of an organic peroxide. A composition.

Further, the fourth invention of the present invention is characterized in that it further comprises (f) 1 to 200 parts by weight of a softener for non-aromatic rubber. It is a thermoplastic elastomer composition.

A fifth aspect of the present invention provides the thermoplastic elastomer composition according to any one of the first to fourth aspects, further comprising (g) 1 to 300 parts by weight of an inorganic filler. It is.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The components constituting the present invention, the production method, and the use thereof will be described in detail below.

1. Components of Thermoplastic Elastomer Composition (1) Elastomer Component (a) The elastomer component (a) used in the present invention comprises the following (a-
It is at least one elastomer selected from the group consisting of 1), (a-2) and (a-3).

(A-1) Block copolymer The block copolymer component (a-1) comprises at least two polymer blocks A mainly composed of an aromatic vinyl compound,
It is a block copolymer comprising at least one polymer block B mainly composed of a conjugated diene compound. For example, ABA, BABA, ABBABA
And an aromatic vinyl compound-conjugated diene compound block copolymer having such a structure.

The above block copolymer contains an aromatic vinyl compound in an amount of 5 to 60% by weight, preferably 20 to 50% by weight, and a polymer block A mainly composed of an aromatic vinyl compound.
Is preferably composed of only an aromatic vinyl compound,
Alternatively, it is a copolymer block of 50% by weight or more, preferably 70% by weight or more of an aromatic vinyl compound and an optional component such as a conjugated diene compound.

The polymer block B mainly composed of a conjugated diene compound is preferably composed of only a conjugated diene compound, or 50% by weight or more, preferably 70% by weight or more of a conjugated diene compound and optional components such as aromatic vinyl. It is a copolymer block with a compound.

The number average molecular weight of the block copolymer is preferably from 5,000 to 1,500,000, more preferably from 10,000 to 550,000, and still more preferably from 1 to 550,000.
It is in the range of 00,000 to 400,000 and the molecular weight distribution is 10 or less. The molecular structure of the block copolymer is
It may be linear, branched, radial or any combination thereof.

In the polymer block A mainly composed of an aromatic vinyl compound and the polymer block B mainly composed of a conjugated diene compound, distribution of units derived from the conjugated diene compound or the aromatic vinyl compound in the molecular chain. May be random, tapered (the monomer component increases or decreases along the molecular chain), partially block-shaped, or an arbitrary combination thereof. When there are two or more polymer blocks A mainly containing an aromatic vinyl compound or two or more polymer blocks B mainly containing a conjugated diene compound, each polymer block has a different structure even if each has the same structure. There may be.

As the aromatic vinyl compound constituting the block copolymer, for example, one or more of styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene and the like can be selected. However, styrene is preferred. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3
One or more kinds are selected from -dimethyl-1,3-butadiene and the like, and among them, butadiene, isoprene and a combination thereof are preferable.

Specific examples of the above block copolymer include:
Styrene-butadiene-styrene copolymer (SBS),
Styrene-isoprene-styrene copolymer (SIS),
And the like.

Numerous methods have been proposed as methods for producing these block copolymers. Typical methods include, for example, a method described in Japanese Patent Publication No. 23798/1971 using a lithium catalyst or Ziegler catalyst. It can be obtained by performing block polymerization in an inert medium using a type catalyst.

(A-2) Hydrogenated block copolymer The hydrogenated block copolymer component (a-2) is a hydrogenated product of (a-1) and is a polymer mainly composed of an aromatic vinyl compound. It is a hydrogenated product of a block copolymer composed of at least two blocks A and at least one polymer block B mainly composed of a conjugated diene compound.

In the hydrogenated product of the component (a-1), in the polymer block B mainly composed of a conjugated diene compound, the hydrogenation rate is optional, but is preferably 50%.
Or more, more preferably 55% or more, and still more preferably 60% or more.
% Or more. Also, its microstructure is optional,
For example, in a polybutadiene block, 1,2-
The microstructure is preferably from 20 to 50% by weight, particularly preferably from 25 to 45% by weight. Moreover, the thing which selectively hydrogenated the 1,2- bond may be used. In the polyisoprene block, isoprene is preferably 70 to 10
Preferably, 0% by weight has a 1,4-microstructure and at least 90% of the aliphatic double bonds derived from isoprene are hydrogenated.

When a hydrogenated block copolymer is used depending on the application, the above hydrogenated product can be appropriately used according to the application.

Specific examples of the hydrogenated block copolymer (a-2) include styrene-ethylene-butene-styrene copolymer (SEBS), styrene-ethylene-propylene-styrene copolymer (SEPS), Styrene-ethylene-ethylene-propylene-styrene copolymer (SE
EPS), styrene-butadiene-butylene-styrene copolymer (partially hydrogenated styrene-butadiene-styrene copolymer, SBBS) and the like.

(A-3) Olefin copolymer rubber The olefin copolymer rubber component (a-3) is obtained by copolymerizing an α-olefin such as ethylene, propylene, 1-butene and 1-pentene. An elastomer or an olefin-based copolymer rubber obtained by copolymerizing these with a non-conjugated diene is exemplified.

Examples of the non-conjugated diene include dicyclopentadiene, 1,4-hexadiene, dicyclooctadiene,
Methylene norbornene, 5-ethylidene-2-norbornene and the like can be mentioned.

Specific examples of such olefin copolymer rubbers include ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber, ethylene-1-butene copolymer rubber, Ethylene-1
-Butene-non-conjugated diene copolymer rubber, ethylene-propylene-1-butene copolymer rubber, and the like.

(2) Polypropylene-based resin component (b) The polypropylene-based resin used in the present invention is a peroxide-decomposable olefin-based resin, which is thermally decomposed by heat treatment in the presence of an organic peroxide to be decomposed. Reduces the fluidity during melting, improves the rubber dispersibility of the obtained elastomer composition, and improves the appearance of the molded article, and has the effect of adjusting the hardness and shrinkage. It is.

The polypropylene resin used in the present invention is:
It is a crystalline polypropylene, and includes a propylene homopolymer and a propylene-α-olefin copolymer having a propylene content of 50 mol% or more. Here, examples of the α-olefin include copolymers with ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, and the like. Among these, a propylene homopolymer, a block or random copolymer of propylene and ethylene is preferred.

In the above block copolymer of propylene and ethylene, the melting point of the homopolymerized portion measured by DSC is 150 to 167 ° C. for Tm and 25 to 83 mJ / for ΔHm.
A range of mg is preferred. The crystallinity can be estimated from Tm and ΔHm measured by DSC. Tm, △ Hm
If it is outside the above range, the oil resistance and rubber elasticity at 150 ° C. or higher of the obtained elastomer composition are not improved.

The melt flow rate of the component (b) (MFR, ASTM D-1238, L condition, 230
C) is preferably 0.1 to 200 g / 10 min, more preferably 0.5 to 100 g / 10 min. If the MFR is less than 0.1 g / 10 minutes, the moldability of the obtained elastomer composition will deteriorate, and if it exceeds 200 g / 10 minutes, the mechanical strength of the obtained elastomer composition will decrease.

The amount of component (b) is 100 parts (a)
The amount is 5 to 500 parts by weight, preferably 10 to 200 parts by weight, based on parts by weight. If the amount is less than 5 parts by weight, the mechanical properties are reduced and the moldability is deteriorated.
If the amount exceeds 00 parts by weight, the heat-resistant deformation resistance of the obtained elastomer composition deteriorates.

(3) Polymethylpentene resin component (c) Polymethylpentene resin component (c) used in the present invention
Is a resin having a high melting point, has excellent heat resistance, and functions as a heat-resistant deformable thermoplastic elastomer composition. The component (c) is a methyl-1-pentene polymer, and is a homopolymer of 4-methyl-1-pentene and / or 3-methyl-1-pentene or 4-methyl-1-pentene and / or Alternatively, a copolymer of 3-methyl-1-pentene and another α-olefin may be used. Among them, 4-methyl-1-
Pentene homopolymers or copolymers of 4-methyl-1-pentene with other α-olefins are preferred. Examples of the α-olefin include ethylene, propylene,
-Butene, 1-octene, 1-decene, 1-dodecene,
C2-C20 alpha-olefins, such as 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosane, are mentioned. Among these, copolymers with α-olefins such as ethylene are more preferable in consideration of flexibility and kneadability with other resins to be blended.

As the copolymer, 4-methyl-1-pentene and / or 3-methyl-1-pentene is preferably at least 80% by weight, more preferably at least 85% by weight,
More preferably, 4-methyl-1- containing 90% by weight or more.
Copolymers mainly composed of pentene and / or 3-methyl-1-pentene are preferred. These can be used alone or in combination of two or more.

The melt flow rate (MFR) of such a 4-methyl-1-pentene and / or 3-methyl-1-pentene polymer is 5.0 kg under a temperature of 260 ° C. according to ASTM D1238. Is preferably in the range of 0.1 to 400 g / 10 min. It is more preferably in the range of 0.5 to 200 g / 10 min, and still more preferably in the range of 1.0 to 150/10 min.

The melting point is preferably from 200 to 260.
° C, more preferably 210-240 ° C, even more preferably 215-235 ° C, and the density (ASTM D150
5) is preferably 0.80 to 0.86 g / cm ³ , more preferably 0.82 to 0.84 g / cm ³ , and still more preferably 0.825 to 0.840 g / cm ^3. is there.

4-methyl-1-pentene and / or 3
As the -methyl-1-pentene polymer, a commercially available product can be used, and specifically, TP manufactured by Mitsui Chemicals, Inc.
X, MX001, MX002, MX004, MX02
1, MX321, RT18 or DX845 (all are trademarks).

The amount of component (c) is 100 parts
The amount is 5 to 450 parts by weight, preferably 10 to 250 parts by weight, based on parts by weight. When the compounding amount is less than 5 parts by weight, the heat deformation resistance deteriorates, and when it exceeds 450 parts by weight,
The mechanical properties of the obtained elastomer composition are reduced and the moldability is deteriorated.

In the elastomer composition of the present invention, the weight ratio of (b) / (c) in the polypropylene resin component (b) and the polymethylpentene resin component (c) is within the above range. 0.2 to 6.5, preferably 0.5 to 6.5. By setting the content within the above range, it is possible to obtain an elastomer composition having an excellent balance between heat deformation resistance and moldability. Weight ratio (b)
If / (c) is less than 0.2, mechanical properties and moldability deteriorate, and if / (c) exceeds 6.5, heat deformation resistance deteriorates.

(4) Polyethylene Resin (d) The thermoplastic elastomer composition of the present invention may optionally contain a polyethylene resin component (d). Component (d) increases viscosity during melting without deteriorating heat deformation resistance, and at the same time, heat-treats in the presence of an organic peroxide to mainly cause a cross-linking reaction and reduce its fluidity. It is. As the component (d),
For example, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ultra-low-density polyethylene and the like can be mentioned. Among these, high density polyethylene is preferred.

The amount of component (d) is 100 parts (a)
When blended with respect to parts by weight, the amount is preferably 1 to 250 parts by weight, more preferably 5 to 100 parts by weight. 2
When the amount exceeds 50 parts by weight, the heat resistance of the obtained elastomer composition is deteriorated.

In the case where the component (d) is blended in the elastomer composition of the present invention, (d) in the polyethylene resin component (d) and the polymethylpentene resin component (c) within the above range. ) / (C) is preferably 0.2 to 4 by weight, more preferably 0.1 to 4%.
5 to 3. By setting the content within the above range, an elastomer composition having improved extrusion moldability and blow moldability without deteriorating heat deformation resistance can be obtained. If the weight ratio (d) / (c) is less than 0.2, extrudability and blow moldability will not be improved, and if it exceeds 4, the heat deformation resistance will deteriorate.

(5) Organic peroxide component (e) The thermoplastic elastomer composition of the present invention may optionally contain an organic peroxide component (e).
The component (e) functions to generate radicals, react the radicals in a chain reaction, and crosslink the component (a) and the component (d) blended as necessary. Also,
At the same time, the component (b) is decomposed to control the fluidity of the composition at the time of melt-kneading, thereby improving the dispersion of the rubber component.

As the component (e), for example, dicumyl peroxide, di-tert-butyl peroxide, 2,
5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di- (t
tert-butylperoxy) hexyne-3, 1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy)-
3,3,5-trimethylcyclohexane, n-butyl-
4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, ter
t-butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, ter
T-butylcumyl peroxide and the like can be mentioned. Among these, from the viewpoints of odor, coloring and scorch safety, 2,5-dimethyl-2,5-di- (ter
t-butylperoxy) hexane, 2,5-dimethyl-
2,5-di- (tert-butylperoxy) hexyne-3 is particularly preferred.

The amount of the component (e) is
It is 0.01 to 3.5 parts by weight, preferably 0.05 to 1.25 parts by weight, based on 100 parts by weight of the component (a). If the amount is less than 0.01 part by weight, crosslinking cannot be sufficiently achieved, and the heat resistance and mechanical strength of the obtained elastomer are low. On the other hand, when the content exceeds 3.5 parts by weight, the moldability deteriorates.

(6) Softener component for non-aromatic rubber (f) The thermoplastic elastomer composition of the present invention may optionally contain a softener component for non-aromatic rubber (f). Can be. Component (f) may include non-aromatic mineral oils or liquid or low molecular weight synthetic softeners. The mineral oil softener used for rubber is a mixture of an aromatic ring, a naphthene ring, and a paraffin chain in which the number of carbon atoms in the paraffin chain accounts for 50% or more of the total number of carbon atoms. Those having a naphthene ring carbon number of 30 to 40% are called naphthenics, and those having an aromatic carbon number of 30% or more are called aromatics.

The mineral oil-based rubber softener used as the component (f) of the present invention is classified into paraffin-based and naphthene-based softeners. The use of an aromatic softening agent is not preferred because its use makes the component (a) soluble and inhibits a cross-linking reaction and the like, so that the physical properties of the obtained composition cannot be improved.
The component (f) is preferably a paraffinic one,
Further, among the paraffin-based compounds, those having less aromatic ring components are particularly suitable. Examples of the liquid or low molecular weight synthetic softener include polybutene, hydrogenated polybutene, low molecular weight polyisobutylene, and the like.

The properties of these softeners for non-aromatic rubbers are such that the dynamic viscosity at 37.8 ° C. is 20 to 50,000.
cSt, dynamic viscosity at 100 ° C. is 5-1500 c
St, the pour point is preferably -10 to -15 ° C, and the flash point (COC) is preferably 170 to 300 ° C. Further, those having a weight average molecular weight of 100 to 2,000 are preferred.

The amount of the component (f) is as follows:
The amount is 1 to 200 parts by weight, preferably 5 to 100 parts by weight, per 100 parts by weight of the component (a). The amount is 1
If the amount is less than part by weight, the moldability deteriorates, and if it exceeds 200 parts by weight, the heat-resistant deformation property of the obtained elastomer composition decreases, and the softener tends to bleed out.

(7) Inorganic filler component (g) In the elastomer composition of the present invention, an inorganic filler component (g) can be blended if necessary. Component (g) has the effect of improving some physical properties such as compression set of molded articles obtained from the elastomer composition,
It has the economic benefits of weight gain. The components (g) include calcium carbonate, talc, silica, diatomaceous earth, barium sulfate, magnesium carbonate, magnesium hydroxide, mica, clay, titanium oxide, carbon black, glass fiber, hollow glass balloon, carbon fiber, calcium titanate fiber , Natural silica, synthetic silica (white carbon)
And the like. Of these, calcium carbonate and talc are particularly preferred.

The amount of the component (g) is as follows:
The amount is preferably from 1 to 300 parts by weight, more preferably from 5 to 100 parts by weight, based on 100 parts by weight of the component (a). 3
If the amount is more than 00 parts by weight, the mechanical strength of the obtained elastomer composition is remarkably reduced, the moldability is deteriorated, and the appearance of the molded product is deteriorated.

(8) Other Components In addition to the above components, the elastomer composition of the present invention may further contain, if necessary, various antiblocking agents.
It may also contain a sealability improver, a heat stabilizer, an antioxidant, a light stabilizer, an ultraviolet absorber, a lubricant, a crystal nucleating agent, a colorant, and the like. Here, as the antioxidant, for example,
2,6-di-tert-p-butyl-p-cresol,
Phenols such as 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol, 4,4-dihydroxydiphenyl, tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane Antioxidants, phosphite antioxidants, thioether antioxidants, and the like. Of these, phenolic antioxidants and phosphite antioxidants are particularly preferred. The antioxidant is preferably used in an amount of 0 to 3.0 parts by weight, particularly preferably 0.1 to 1.0 part by weight, based on 100 parts by weight of the total of the components (a) to (f).

2. Production of Thermoplastic Elastomer Composition The thermoplastic elastomer composition of the present invention comprises the above components (a) to (c) or, if necessary, components (d) to (g).
And then melt-kneading the components simultaneously or in any order.

The method of melt kneading is not particularly limited, and a generally known method can be used. For example, a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, various kneaders, or the like can be used. For example, a moderate L / D twin screw extruder,
The above operation can be performed continuously by using a Banbury mixer, a pressure kneader, or the like. Here, the temperature of the melt-kneading is preferably from 200 to 270 ° C.

3. Uses of the thermoplastic elastomer composition The thermoplastic elastomer composition of the present invention has good mechanical properties, does not thermally deform at a high temperature of 150 ° C or higher, can be used continuously, and has extrudability and injection moldability. Since it is excellent in blow moldability, it can be mainly used for applications such as members in an automobile engine room and members around the engine.

[0059]

EXAMPLES The present invention will be specifically described with reference to the following examples and comparative examples, but the present invention is not limited to these examples. The methods and samples for measuring physical properties used in the present invention are shown below.

1. Physical property measurement method (1) Hardness: A 6.3 mm thick pressed sheet was used as a test piece in accordance with JIS K6253.

(2) Flexural modulus: ASTM D 790
And measured at room temperature using a 6.3 mm-thick press sheet.

(3) Tensile strength: According to JIS K6251, a 1 mm thick press sheet was punched out into a No. 3 dumbbell-type test piece and used. Tensile speed is 500mm
/ Min. (Measured at room temperature and 150 ° C.)

(4) 100% elongation stress: JIS K6
In accordance with No. 251, the test piece was a 1 mm thick pressed sheet
No. dumbbell-shaped test piece was used. Tensile speed is 5
00 mm / min.

(5) Elongation at break: According to JIS K6251, a 1 mm thick press sheet was punched out into a No. 3 dumbbell-type test piece. Tensile speed is 500mm
/ Min.

(6) Injection moldability: Using an injection molding machine with a mold clamping pressure of 120 tons, a molding temperature of 220 ° C. and a mold temperature of 40
° C, injection speed 55mm / sec, injection pressure 600kg / cm
² , a holding pressure of 400 kg / cm ² , an injection time of 6 seconds, a cooling time of 45 seconds, and a 13.5 × 13.5 × 2 mm sheet were formed. The presence or absence of a flow mark that would cause delamination, surface layer peeling, deformation, and significantly deteriorating the appearance was visually determined and evaluated according to the following criteria. ◎: Very good ○: Good ×: Poor

(7) Extrusion Formability: A sheet of 50 mm × 1 mm was extruded, and the drawdown property, surface appearance and shape were observed and evaluated according to the following criteria. ◎: Very good ○: Good ×: Poor

(8) Blow moldability: 2 mm thick x 25 mm
A cylindrical parison of φ was blown twice, and the drawdown property, surface appearance and shape were observed, and evaluated according to the following criteria. ◎: Very good ○: Good ×: Poor

2. Samples used in Examples and Comparative Examples (1) SBS block copolymer component (a-1): VEC
TOR2518 (manufactured by DEXCO POLYMERS) (2) Hydrogenated block copolymer component (a-2): Septon 4077 (manufactured by Kuraray Co., Ltd.), styrene content: 30
% By weight, isoprene / butadiene content: 70% by weight,
Number average molecular weight: 260,000, weight average molecular weight: 32
000, molecular weight distribution: 1.23, hydrogenation rate: 90
% Or more (3) Olefin copolymer rubber component (a-3): ethylene-butene copolymer (EBR); Esprene N0441
(Manufactured by Sumitomo Chemical Co., Ltd.) (4) Polypropylene (PP) component (b): PP-BC
8 (manufactured by Nippon Polychem Co., Ltd.), crystallinity: Tm166
° C, ΔHm82mJ / mg, MFR 1.8g / 10min (230 ° C, 2.16kg) (5) Polymethylpentene resin component (c): TPX
MX021 (manufactured by Mitsui Chemicals, Inc.) (6) Polyethylene resin component (d): HDPE-HB-
214R (manufactured by Nippon Polychem Co., Ltd.), crystallinity: Tm
130 ° C, ΔHm106mJ / mg, MFR0.05g
/ 10 min (190 ° C, 2.16 kg) (7) Organic peroxide component (e): Perhexa 25B (manufactured by NOF Corporation) (8) Softener component (f): Diana Process Oil P
W-90 (manufactured by Idemitsu Kosan Co., Ltd.) (9) Calcium carbonate component (g): NS400 (manufactured by Sankyo Seiko Co., Ltd.) (10) Hindered phenol / phosphite / lactone complex antioxidant component (h): HP2215 (manufactured by Ciba Specialty Chemicals)

Examples 1 to 8 and Comparative Examples 1 to 4 Using the components shown in Tables 1 and 2, the mixture was charged into a twin screw extruder having an L / D of 47, and kneading temperature was 250 ° C. Melt kneading was performed at several 350 rpm to form pellets. Next, the obtained pellets were injection molded to prepare test pieces, which were subjected to the respective tests. The evaluation results are shown in Tables 1 and 2.

[0070]

[Table 1]

[0071]

[Table 2]

As is clear from Tables 1 and 2, Examples 1 to 8 are the thermoplastic elastomer compositions of the present invention. Regardless of the presence or absence of optional components (d) to (h), any of the thermoplastic elastomer compositions showed good properties. Septon 4077 of component (a-2)
A part or all of the resin is Tuftec P JT-90 (styrene-butadiene-butylene-styrene copolymer manufactured by Asahi Kasei Corporation, SBBS, styrene content: 30% by weight, weight average molecular weight (Mw): 110,000, number average) Molecular weight (M
n): 99000, molecular weight distribution: 1.11), the same good results were obtained.

On the other hand, Comparative Example 1 was a case where the component (b) was not blended, and the thermoplastic elastomer composition was inferior in elongation at break and poor in injection moldability, extrusion moldability and blow moldability. Comparative Example 2 was a case where the component (c) was not blended, and the thermoplastic elastomer composition had a tensile strength at a high temperature of 0 and was inferior in heat resistance. Comparative Example 3 was a case where the amount of the component (b) was too large and (b) / (c) was too large, and the thermoplastic elastomer composition had a low tensile strength at a high temperature and was inferior in heat resistance. Comparative Example 4 shows (b) /
(C) was too small, and the thermoplastic elastomer composition was inferior in elongation at break, and injection moldability, extrusion moldability, and blow moldability were deteriorated.

[0074]

Industrial Applicability The thermoplastic elastomer composition of the present invention has good mechanical properties, does not thermally deform at a high temperature of 150 ° C. or higher, can be used continuously, and has extrudability, injection moldability, and blowability. Since it has excellent moldability, it can be mainly used for applications such as members in an automobile engine room and members around the engine.

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Claims (5)

[Claims] 1. A block comprising (a) (a-1) at least two polymer blocks A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound. Copolymer (a-2) (a-
100 parts by weight of at least one elastomer selected from the group consisting of a hydrogenated block copolymer obtained by hydrogenating 1) and (a-3) an olefin-based copolymer rubber;
A composition comprising (b) 5 to 500 parts by weight of a polypropylene resin and (c) 5 to 450 parts by weight of a polymethylpentene resin, wherein the weight ratio of (b) / (c) is 0.1%.
A thermoplastic elastomer composition having a composition of 2 to 6.5. 2. The composition further comprises (d) 1 to 250 parts by weight of a polyethylene resin, and the weight ratio of (d) / (c) is 0.2 to 4
The thermoplastic elastomer composition according to claim 1, wherein 3. The thermoplastic elastomer composition according to claim 1, further comprising (e) 0.01 to 3.5 parts by weight of an organic peroxide. (F) softeners for non-aromatic rubbers 1 to 20
The thermoplastic elastomer composition according to any one of claims 1 to 3, further comprising 0 parts by weight. 5. The thermoplastic elastomer composition according to claim 1, further comprising (g) 1 to 300 parts by weight of an inorganic filler.