JP2001181459A - Heat-resistant thermoplastic elastomer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic elastomer composition capable of giving molded forms with high heat resistance and excellent flexibility and rubbery properties as well. SOLUTION: This thermoplastic elastomer composition is obtained by compounding (A) 100 pts.wt. of a thermoplastic elastomer produced by dynamic heat treatment of (a) a crystalline olefin-based resin and (b) a rubber in the presence of a crosslinking agent with (B) 3-300 pts.wt. of a 4-methyl-1-pentene- based polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic elastomer composition, and more particularly to a thermoplastic elastomer composition capable of providing a molded article having excellent heat resistance.

[0002]

2. Description of the Related Art Vulcanized rubber has excellent flexibility and heat resistance, but has problems in moldability. For example, in the case of injection molding, an additive is compounded and kneaded in rubber and supplied into a mold. After that, since it is necessary to crosslink, a special molding machine is required, the molding cycle time is long, and the process is complicated. Extrusion molding has a similar problem, which is a problem in mass-producing crosslinked rubber products. Further, after vulcanized rubber is once molded and vulcanized, it does not melt even if reheated, so that there is also a problem that post-processing such as joining cannot be performed.

In view of the above, thermoplastic elastomers have recently been used in place of vulcanized rubbers. Among them, olefin-based thermoplastic elastomers have been used in light of light weight, environmental pollution resistance, and economy. Is increasing. However, conventional olefin-based thermoplastic elastomers have insufficient heat resistance as compared with vulcanized rubbers, and improvement thereof has been desired.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic elastomer composition which is excellent in heat resistance and can obtain a molded article excellent in flexibility and rubber properties.

[0005]

The present invention relates to the following heat-resistant thermoplastic elastomer composition. (1) 4-methyl-1 based on 100 parts by weight of a thermoplastic elastomer (A) obtained by dynamically heat-treating a crystalline olefin-based resin (a) and a rubber (b) in the presence of a crosslinking agent. -A heat-resistant thermoplastic elastomer composition containing the pentene polymer (B) in a proportion of 3 to 300 parts by weight. (2) A 4-methyl-1-pentene polymer (B) is
4-methyl-1-pentene content 80 to 99.9% by weight, α-olefin having 2 to 20 carbon atoms 0.1 to 2
The heat-resistant thermoplastic elastomer composition according to the above (1), which is 0% by weight of a 4-methyl-1-pentene / α-olefin random copolymer. (3) The heat-resistant thermoplastic elastomer composition according to the above (1) or (2), wherein the crystalline olefin-based resin (a) is a crystalline propylene-based polymer. (4) The rubber (b) is ethylene / α-olefin / non-conjugated polyene copolymer rubber, ethylene / α-olefin copolymer rubber, isoprene rubber or its hydrogenated product, butadiene rubber or its hydrogenated product, styrene -Butadiene rubber or its hydrogenated product, styrene-isoprene rubber or its hydrogenated product, chloroprene rubber, butyl rubber, halogenated butyl rubber, acrylonitrile-butadiene rubber, chlorinated polyethylene rubber, fluorine rubber, silicone rubber,
The heat-resistant thermoplastic elastomer composition according to any one of the above (1) to (3), which is at least one kind of rubber selected from the group consisting of polysulfide rubber and urethane rubber. (5) The gel content in the thermoplastic elastomer (A) is 5
The heat-resistant thermoplastic elastomer composition according to any one of the above (1) to (4), which is 0% by weight or more. (6) The heat-resistant thermoplastic elastomer composition according to any one of the above (1) to (5), wherein the crosslinking agent is an organic peroxide. (7) The heat-resistant thermoplastic elastomer composition according to any one of (1) to (6), wherein the thermoplastic elastomer (A) is obtained by dynamically heat-treating with a twin-screw extruder.

[Crystalline olefin-based resin (a)] The crystalline olefin-based resin (a) used in the present invention is obtained by subjecting one or more monoolefins to a high-pressure method or a low-pressure method. It is a crystalline high molecular weight solid product obtained by polymerization. Examples of such a crystalline olefin resin (a) include isotactic and syndiotactic monoolefin polymer resins. These representative resins are commercially available.

Suitable starting olefins for the crystalline olefin resin (a) include ethylene, propylene, 1-butene, 1-pentene, 1-hexene and 1-hexene.
-Octene, 1-decene, 2-methyl-1-propene,
C2-C20 such as 3-methyl-1-pentene, 4-methyl-1-pentene and 5-methyl-1-hexene;
Preferably, there are 2 to 12 α-olefins. These α-olefins are used alone or in combination of two or more.

[0008] Regarding the polymerization mode, any type of polymerization mode can be adopted as long as a resinous material can be obtained, whether it is a random type or a block type.

As the crystalline olefin resin (a), a propylene polymer is preferable, and specifically, propylene homopolymer, propylene / ethylene block copolymer, propylene / ethylene, and propylene / ethylene / butene random copolymer are preferable.

The crystalline olefin resin (a) used in the present invention has a melt flow rate (MFR: ASTM).
D 1238-65T, 230 ° C, 2.16 kg load)
Is usually 0.01 to 100 g / 10 min, preferably 0.0
It is desirable to be in the range of 5 to 50 g / 10 minutes.

The above-mentioned crystalline olefin resin (a) has a role of improving the fluidity and heat resistance of the heat-resistant thermoplastic elastomer composition of the present invention. The crystalline olefin resin (a) may be used alone or in combination of two or more.

[Rubber (b)] The rubber (b) used in the present invention is an ethylene / α-olefin / non-conjugated polyene copolymer rubber, an ethylene / α-olefin copolymer rubber, isoprene rubber or a hydrogenated hydrogenated isoprene rubber. Product, butadiene rubber or its hydrogenated product, styrene / butadiene rubber or its hydrogenated product, styrene / isoprene rubber or its hydrogenated product, chloroprene rubber, butyl rubber, halogenated butyl rubber, acrylonitrile / butadiene rubber, chlorinated polyethylene rubber, fluorine It is at least one rubber selected from the group consisting of rubber, silicone rubber, polysulfide rubber and urethane rubber. Among them, ethylene / α-olefin / non-conjugated polyene copolymer rubber is preferable, and particularly, the molar ratio of ethylene / propylene is from 30/70 to 90 /.
10, preferably 55/45 to 85/15, iodine value of 1 to 30 g / 100 g, preferably 3 to 25 g / 100
g, Mooney viscosity ML _{1 + 4} (100 ° C.) is 15 to 250,
Preferably an ethylene / propylene / non-conjugated diene rubber of 30 to 160 is preferred.

[Thermoplastic Elastomer (A)] The thermoplastic elastomer (A) used in the present invention is prepared by moving the crystalline olefin resin (a) and rubber (b) in the presence of a crosslinking agent by the method described below. It is an elastomer obtained by thermal treatment.

The ratio of the crystalline olefin resin (a) and the rubber (b) used is such that the amount of the crystalline olefin resin (a) is 10 to 80 with respect to the total amount of the crystalline olefin resin (a) and the rubber (b). % By weight, preferably 15 to 60% by weight, and rubber (b) 90 to 20% by weight, preferably 85 to 85% by weight.
Desirably, it is 40% by weight. When the use ratio of the crystalline olefin-based resin (a) and the rubber (b) is in the above range, the heat-resistant thermoplastic elastomer composition of the present invention which is excellent in flexibility and rubber elasticity and excellent in molding processing can be obtained. .

The thermoplastic elastomer (A) used in the present invention may contain a softening agent and / or an inorganic filler as other components in addition to the crystalline olefin resin (a) and the rubber (b). it can.

As the softening agent used as another component, a softening agent usually used for rubber can be used. Specifically, petroleum-based substances such as process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, petrolatum; coal tars such as coal tar and coal tar pitch; castor oil, linseed oil, rapeseed oil, soybean oil, Fatty oils such as coconut oil; waxes such as tall oil, beeswax, carnauba wax and lanolin; fatty acids such as ricinoleic acid, palmitic acid, stearic acid, barium stearate and calcium stearate or metal salts thereof;
Synthetic polymer substances such as coumarone indene resin and atactic polypropylene; ester plasticizers such as dioctyl phthalate, dioctyl adipate and dioctyl sebacate; other microcrystalline waxes, sub (factice), liquid polybutadiene, modified liquid polybutadiene, liquid thiocol And so on.

In the present invention, the softener is used in an amount of 150 parts by weight or less, preferably 2 to 100 parts by weight, more preferably 5 parts by weight, based on 100 parts by weight of the total amount of the crystalline olefin resin (a) and the rubber (b). It is used in a proportion of ~ 80 parts by weight. When the softening agent is used in the above ratio, the obtained heat-resistant thermoplastic elastomer composition of the present invention has excellent fluidity during molding and does not lower the mechanical properties of the molded article. In the present invention, the softener may be added during the production of the thermoplastic elastomer (A) or may be added in advance to the rubber (b).
May be oil-exhibited.

As the inorganic filler used as other components, specifically, calcium carbonate, calcium silicate,
Clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, alumina, barium sulfate, aluminum sulfate, calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite, glass fiber, glass sphere, shirasu balloon, basic sulfuric acid Examples include magnesium whiskers, calcium titanate whiskers, and aluminum borate whiskers.

In the present invention, the inorganic filler comprises a total amount of the crystalline olefin resin (a) and the rubber (b) of 10%.
100 parts by weight or less, preferably 2 to 5 parts by weight with respect to 0 parts by weight
It is used in a proportion of 0 parts by weight. In the present invention, when the amount of the inorganic filler is in the above range, the heat-resistant thermoplastic elastomer composition of the present invention having excellent rubber elasticity and moldability can be obtained.

The thermoplastic elastomer (A) may further contain, as other components, known heat-resistant stabilizers, anti-aging agents, weather-resistant stabilizers, antistatic agents, lubricants such as metal soaps, waxes, and the like. It can be added within a range that does not impair.

The thermoplastic elastomer (A) used in the present invention comprises the above-mentioned crystalline olefin resin (a),
The rubber (b) is obtained by mixing the rubber (b) and other components to be blended as required, and then dynamically performing a heat treatment in the presence of a crosslinking agent. Here, “dynamically heat-treating” means that the crystalline olefin-based resin (a) and the rubber (b) are kneaded in a molten state.

Examples of the crosslinking agent used for the dynamic heat treatment include organic peroxides, phenol resins, sulfur, hydrosilicone compounds, amino resins, quinones or derivatives thereof, amine compounds, azo compounds, and epoxy compounds. Crosslinking agents generally used in thermosetting rubbers, such as compounds and isocyanates, may be mentioned. Among these crosslinking agents, organic peroxides are preferred.

Examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, and 2,5-dimethylperoxide. Dimethyl-2,5-
Di- (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,
tert-butyl perbenzoate, tert-butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butyl cumyl peroxide and the like.

Among them, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane and 2,5-dimethyl-2,5 are preferable in terms of odor and scorch stability.
-Di- (tert-butylperoxy) hexyne-3,
1,3-Bis (tert-butylperoxyisopropyl) benzene is preferred, of which 2,5-dimethyl-
2,5-di- (tert-butylperoxy) hexane is most preferred.

Such an organic peroxide is used in an amount of 0.02 to 3 parts by weight, preferably 0.05 to 3 parts by weight, based on 100 parts by weight of the total of the crystalline polyolefin resin (a) and the rubber (b).
It is used in such an amount that it becomes １1 part by weight. When the compounding amount of the organic peroxide is within the above range, appropriate crosslinking proceeds, so that a thermoplastic elastomer (A) excellent in heat resistance, tensile properties, elastic recovery, rebound resilience, moldability and the like can be obtained.

In the present invention, sulfur, p-quinonedioxime, p,
p'-dibenzoylquinone dioxime, N-methyl-N
-4-dinitrosoaniline, nitrosobenzene, diphenylguanidine, trimethylolpropane-N, N'-
Peroxy crosslinking auxiliary such as m-phenylenedimaleimide, or polyfunctional such as divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate Polyfunctional vinyl monomers such as a functional methacrylate monomer, vinyl butyrate, and vinyl stearate can be blended.

By using a compound as described above,
A uniform and mild crosslinking reaction can be expected. In the present invention, divinylbenzene is most preferred. Divinylbenzene is easy to handle, and the crystalline polyolefin resin (a)
And good compatibility with the rubber (b), and has a function of solubilizing the organic peroxide, and acts as a dispersant for the organic peroxide. A thermoplastic elastomer (A) having a balance with physical properties can be obtained.

The compound such as the above-mentioned crosslinking aid or polyfunctional vinyl monomer is used in an amount of usually not more than 2 parts by weight, preferably not more than 2 parts by weight, based on 100 parts by weight of the total of the crystalline polyolefin resin (a) and the rubber (b). It is used in an amount of 0.3 to 1 part by weight.

In order to accelerate the decomposition of the organic peroxide, triethylamine, tributylamine, 2,4,6
-Decomposition accelerators such as tertiary amines such as tri (dimethylamino) phenol and naphthenates such as aluminum, cobalt, vanadium, copper, calcium, zirconium, manganese, magnesium, lead and mercury may be used.

The dynamic heat treatment in the present invention is preferably performed in a non-open type apparatus, and is preferably performed in an atmosphere of an inert gas such as nitrogen or carbon dioxide. The temperature of the heat treatment is 3 degrees from the melting point of the crystalline polyolefin resin (a).
It is in the range of 00 ° C, usually 150 to 250 ° C, preferably 170 ° C to 225 ° C. The kneading time is usually 1-2.
0 minutes, preferably 1 to 10 minutes. The applied shearing force is a shear rate of 10 to 50,000 sec.
c ^-1 , preferably in the range of 100 to 20,000 sec ^-1 .

As a kneading apparatus, a mixing roll, an intensive mixer (for example, Banbury mixer, kneader), a single-screw or twin-screw extruder can be used, but a non-open type apparatus is preferable, and a twin-screw extruder is particularly preferable. .

The thermoplastic elastomer (A) has a gel content of at least 50% by weight, preferably 8% by the following method.
It is desirably 0% by weight or more. [Measurement method of gel content] A 100 mg sample of the thermoplastic elastomer (A) was sampled, and 0.5 mm × 0.5 mm
A sample cut into × 0.5 mm strips is immersed in 30 ml of cyclohexane at 23 ° C. for 48 hours in a closed container, then the sample is taken out on a filter paper and dried at room temperature for at least 72 hours until a constant weight is obtained. I do.

From the weight of the dried residue, the weight of all cyclohexane-insoluble components (fibrous filler, filler, pigment, etc.) other than the polymer component, and the weight of the crystalline polyolefin resin (a) in the sample before immersion in cyclohexane are determined. The reduced value is referred to as “corrected final weight (Y)”.
On the other hand, the weight of the rubber (b) in the sample is referred to as “corrected initial weight (X)”. Here, the gel content is determined by the following equation (1).

Gel content (% by weight) = [corrected final weight (Y) / corrected initial weight (X)] × 100 (1)

[4-methyl-1-pentene polymer (B)] The 4-methyl-1-pentene polymer (B) used in the present invention is a homopolymer of 4-methyl-1-pentene. It may be a random copolymer of 4-methyl-1-pentene and another α-olefin. Examples of the α-olefin copolymerized with 4-methyl-1-pentene include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, Α-olefins having 2 to 20 carbon atoms, preferably 6 to 20 carbon atoms, such as 1-octadecene and 1-eicosene. 4-
Α-olefin copolymerized with methyl-1-pentene is 2
There may be more than one species.

4-Methyl-1-pentene polymer (B)
Is a copolymer, the content of 4-methyl-1-pentene is 80 to 99.9% by weight, preferably 90 to 99.9% by weight, and the content of the copolymer component is 0.1 to 20% by weight. And a copolymer containing 4-methyl-1-pentene as a main component, preferably 0.1 to 10% by weight. When the content of the copolymer component is in the above range, a heat-resistant thermoplastic elastomer composition of the present invention having more excellent heat resistance can be obtained.

4-Methyl-1-pentene polymer (B)
MFR (ASTM D 1238, 260 ° C, 5 kg
Load) is 0.1 to 200 g / 10 min, preferably 1 to 1
Those in the range of 50 g / 10 minutes are preferred.

4-Methyl-1-pentene polymer (B)
Can also use a commercial item. Commercially available products include, for example, TPX MX001 and MX00 manufactured by Mitsui Chemicals, Inc.
2, MX004, MX021, MX321, RT18 or DX845 (all are trademarks). Other manufacturers' products can be used if they meet the above requirements. 4-methyl-1-pentene polymer (B)
Can be used alone, or two or more can be used in combination.

[Heat-Resistant Thermoplastic Elastomer Composition] The heat-resistant thermoplastic elastomer composition of the present invention comprises 4-methyl-per 100 parts by weight of the thermoplastic elastomer (A).
It is a thermoplastic elastomer composition containing 3 to 300 parts by weight, preferably 10 to 150 parts by weight of the 1-pentene polymer (B). 4-methyl-1-pentene polymer (B)
Is within the above range, the heat-resistant thermoplastic elastomer composition of the present invention having excellent heat resistance and excellent flexibility and rubber elasticity can be obtained.

If necessary, the heat-resistant thermoplastic elastomer composition of the present invention may contain the above-mentioned softener, inorganic filler, heat-resistant stabilizer, anti-aging agent, weather-resistant stabilizer, anti-static agent, lubricant such as metal soap and wax. Other components can be blended.

The heat-resistant thermoplastic elastomer composition of the present invention is produced by mixing the thermoplastic elastomer (A), the 4-methyl-1-pentene polymer (B) and other components to be blended if necessary. However, it is preferable to use the dynamic heat treatment method described above. However, the heat treatment is performed at a temperature equal to or higher than the melting point of the 4-methyl-1-pentene polymer (B). Specifically, it is desirable to heat-treat dynamically at a temperature in the range of 240 to 300 ° C, preferably 240 to 270 ° C.

[0041]

The heat-resistant thermoplastic elastomer composition of the present invention comprises a thermoplastic elastomer (D) obtained by dynamically heat-treating a crystalline olefin resin (a) and a rubber (b) in the presence of a crosslinking agent. A) Since a specific amount of the 4-methyl-1-pentene polymer (B) is contained, a molded article having excellent heat resistance and excellent flexibility and rubber properties can be obtained.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. The polymers used in the examples and comparative examples are as follows.

(A-1) Propylene homopolymer: MF
R (ASTM D 1238-65T, 230 ° C, 2.
16 kg load) = 10 (g / 10 minutes), sometimes abbreviated as PP hereinafter. (B-1) oil-extended ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber: molar ratio of units derived from ethylene to units derived from propylene (ethylene / propylene) = 79/21; Iodine value based on ethylidene norbornene = 13, Mooney-viscosity ML
_{1 + 4} (100 ° C.) = 140 parts by weight of a copolymer rubber having a mineral oil softening agent (PW-Idemitsu Kosan Co., Ltd.)
380 (trademark)) may be abbreviated as oil-extended rubber, hereinafter oil-extended EPDM, in an oil-extended proportion of 80 parts. (B-2) Butyl rubber: Mooney viscosity ML _{1 + 4} (100
° C) = 65, degree of unsaturation = 0.7 mol%

(B-1) 4-methyl-1-pentene copolymer: TPX MX002 (trade name) manufactured by Mitsui Chemicals, Inc., MFR (ASTM D1238, 260 ° C., 5 ° C.)
kg load) = 23 g / 10 min, 4-methyl-1-pentene content = 93% by weight, content of a mixture of olefins having 16,18 carbon atoms (trade name: Dialen D-168) =
7% by weight

Example 1 As shown in Table 1, propylene homopolymer (a-1)
Of ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber (b-1) 135 parts by weight (75 parts by weight of copolymer, amount of softener) 60 parts by weight), an organic peroxide [2,5-dimethyl-2,5-di- (tert-
Butylperoxy) hexane], and 0.4 part by weight of divinylbenzene, and thoroughly mixed in a Henschel mixer. Then, the mixture was fed to a twin-screw extruder and subjected to dynamic heat treatment under the following conditions. Pellets of the thermoplastic elastomer (A-1) were obtained.

[Dynamic heat treatment conditions] Extruder: ZSK-53 (trade name) manufactured by Werner & Freidel, screw diameter: 53 mm Temperature setting: C1 / C2 / C3 / C4 / C5 / D = 140
/ 160/180/220/220/200 (° C) Maximum shear rate: 2800 (1 / sec) Extrusion amount: 50 (kg / h)

Next, as shown in Table 2, 100 parts by weight of the thermoplastic elastomer (A-1) pellets and 4 parts by weight
After mixing 50 parts by weight of pellets of the -methyl-1-pentene copolymer (B-1) again with a Henschel mixer,
The mixture was fed to a twin-screw extruder and subjected to dynamic heat treatment under the following conditions to obtain pellets of a thermoplastic elastomer composition.

[Dynamic heat treatment conditions] Extruder: ZSK-53 (trade name) manufactured by Werner & Freidel, screw diameter: 53 mm Temperature setting: C1 / C2 / C3 / C4 / C5 / D = 200
/ 240/260/270/270/250 (° C) Maximum shear rate: 2000 (1 / sec) Extrusion output: 60 (kg / h)

Next, predetermined test pieces were prepared by injection molding using the pellets of the thermoplastic elastomer composition, and the permanent elongation and the softening temperature were measured. Table 2 shows the results.

Comparative Example 1 In Example 1, a propylene homopolymer (a-polymer) was used in place of the 4-methyl-1-pentene copolymer (B-1).
Dynamic heat treatment was performed in the same manner as in Example 1 except that 1) was used to obtain pellets of the thermoplastic elastomer composition. Next, a test piece was prepared using the pellets in the same manner as in Example 1, and the permanent elongation and the softening temperature were measured. Table 2 shows the results.

Example 2 As shown in Table 1, propylene homopolymer (a-1)
20 parts by weight of the pellets and 20 parts by weight of butyl rubber (b-2) were kneaded with a Banbury mixer heated to 170 ° C. for 10 minutes, then passed through an open roll to form a sheet having a thickness of 4 mm, and further cut with a cutter to form a 4 mm square. Was prepared. Next, 40 parts by weight of these pellets and 108 parts by weight of oil-extended ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber (b-1) pellets (60 parts by weight of the copolymer rubber, softening 48 parts by weight of the agent), an organic peroxide [2,5-dimethyl-
2,5-di- (tert-butylperoxy) hexane] and 0.5 parts by weight of divinylbenzene, and thoroughly mixed in a Henschel mixer. Heat treatment was performed to obtain pellets of the thermoplastic elastomer (A-2).

Next, the thermoplastic elastomer (A-
2) 100 parts by weight of the pellet and 70 parts by weight of the pellet of the 4-methyl-1-pentene copolymer (B-1) were mixed again with a Henschel mixer, and then subjected to a dynamic heat treatment in the same manner as in Example 1. Thus, pellets of the thermoplastic elastomer composition were obtained. Next, a test piece was prepared using the thermoplastic elastomer composition pellets in the same manner as in Example 1, and the permanent elongation and the softening temperature were measured. Table 2 shows the results.

Comparative Example 2 In Example 2, a propylene homopolymer (a-polymer) was used in place of the 4-methyl-1-pentene copolymer (B-1).
Dynamic heat treatment was performed in the same manner as in Example 2 except that 1) was used, to obtain pellets of the thermoplastic elastomer composition. Next, a test piece was prepared using the pellet in the same manner as in Example 2, and the permanent elongation and the softening temperature were measured. Table 2 shows the results.

[0054]

[Table 1] * 1 Organic peroxide: 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane * 2 Gel content: calculated from the above formula (1) by the above method.

[0055]

[Table 2] * 1 A-1: See Table 1 * 2 A-2: See Table 1 * 3 Permanent elongation: Measured in accordance with JIS K6301. However, the retained length was a length corresponding to 100% elongation. * 4 Softening temperature: Using a DuPont TMA measuring device, the temperature at which a needle with a load of 49 g was inserted by 0.1 mm was defined as the softening temperature. The heating rate was 20 ° C./min.

From the results shown in Table 2, it can be seen that the thermoplastic elastomer compositions of Examples have a higher softening temperature and higher heat resistance than those of Comparative Examples, and have the same rubber properties.

Continued on the front page F-term (reference) 4J002 AC03W AC06W AC07W AC08W BB12W BB15W BB17X BB18W BB24W BB26W BC05W BD12W BN06W BN13W BP02W CH023 CK02W CP03W EA056 EH076 EK036 EK046 EK0146 EK046 EK0EK

Claims (7)

[Claims] 1. A thermoplastic elastomer (A) obtained by dynamically heat-treating a crystalline olefin-based resin (a) and a rubber (b) in the presence of a crosslinking agent is added to 100 parts by weight of a thermoplastic elastomer (A).
A heat-resistant thermoplastic elastomer composition containing the methyl-1-pentene polymer (B) in a proportion of 3 to 300 parts by weight. 2. A 4-methyl-1-pentene polymer (B) having a 4-methyl-1-pentene content of 80 to 9;
9.9% by weight, 4-methyl-1-pentene-α-olefin having an α-olefin content of 2 to 20 carbon atoms of 0.1 to 20% by weight.
The heat-resistant thermoplastic elastomer composition according to claim 1, which is an olefin random copolymer. 3. The heat-resistant thermoplastic elastomer composition according to claim 1, wherein the crystalline olefin resin (a) is a crystalline propylene polymer. 4. The rubber (b) is ethylene / α-olefin / non-conjugated polyene copolymer rubber, ethylene / α-olefin copolymer rubber, isoprene rubber or hydrogenated product thereof, butadiene rubber or hydrogenated product thereof , Styrene-butadiene rubber or its hydrogenated product, styrene-isoprene rubber or its hydrogenated product, chloroprene rubber, butyl rubber,
4. A rubber according to claim 1, which is at least one rubber selected from the group consisting of halogenated butyl rubber, acrylonitrile / butadiene rubber, chlorinated polyethylene rubber, fluorine rubber, silicone rubber, polysulfide rubber and urethane rubber.
A heat-resistant thermoplastic elastomer composition according to any one of the above. 5. The heat-resistant thermoplastic elastomer composition according to claim 1, wherein the gel content of the thermoplastic elastomer (A) is 50% by weight or more. 6. The heat-resistant thermoplastic elastomer composition according to claim 1, wherein the crosslinking agent is an organic peroxide. 7. The heat-resistant thermoplastic elastomer composition according to claim 1, wherein the thermoplastic elastomer (A) is obtained by dynamically heat-treating with a twin-screw extruder.