JP3254807B2 - Thermoplastic elastomer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic elastomer composition. More specifically, the present invention relates to an olefin-based thermoplastic elastomer composition having excellent mechanical properties, capable of replacing a vulcanized rubber, having little oil bleed, and having good appearance.

[0002]

2. Description of the Related Art Thermoplastic elastomers (hereinafter referred to as "TP")
E ". ) Does not require a vulcanization step and can be processed with a normal thermoplastic resin molding machine. Applications have been developed in a wide range of fields, including automobile parts, home electric parts, and miscellaneous goods. I have. Among them, the olefin-based TPE composition is known from JP-A-48-26838 and the like. However, this composition is inferior to vulcanized rubber in terms of flexibility, tensile strength at break, elongation at break, compression set and the like, and thus has limited applications.
In order to improve these performances, the addition of a mineral oil-based softening agent or a peroxide non-crosslinked hydrocarbon-based rubber-like substance imparts flexibility, and the use of a crosslinking aid increases the degree of crosslinking and improves compression set. Various attempts have been made. (For example, JP-B-56-15740).

However, in these compositions, even if the degree of cross-linking is increased to improve the compression set, the flexibility is reduced, the breaking strength and elongation at break in a tensile test are reduced, or the composition is softened to the surface. It is difficult to obtain an olefin-based TPE composition having an excellent balance of physical properties due to bleeding of the agent.

[0004]

The problem to be solved by the present invention under the present circumstances is that olefin-based TPEs, especially olefin-based TPEs having a low hardness (90 or less in Shore A hardness).
PE has less oil bleed, good appearance, flexibility and mechanical properties (especially tensile strength at break, elongation at break, compression set).
Olefin TP with good extrudability or injection moldability
An object of the present invention is to provide an E composition.

[0005]

The present inventors have conducted intensive studies to overcome the above-mentioned drawbacks of the conventional method, and as a result, an oil-extended olefin copolymer containing a specific mineral oil-based softener in advance. Using a rubber and a specific ethylene-α-olefin copolymer resin, a composition obtained by partially cross-linking a mixture containing them is found to be excellent in flexibility and mechanical properties, and to complete the present invention. Reached. That is, the present invention
° C Mooney viscosity (ML _{1 + 4} 100 ° C) is 120-350
Per 100 parts by weight of the olefin copolymer rubber
40-95% by weight of an oil-extended olefin-based copolymer rubber (A) containing 20-150 parts by weight of a mineral oil-based softener and an ethylene-α-olefin copolymer having the following properties (b1)-(b5) (B) 0.005 to 2.0 parts by weight of organic peroxide (C), 0.01 to 4.0 parts by weight of crosslinking aid (D), and at least one selected from polybutene, polyisobutylene and butyl rubber, based on a total of 100 parts by weight of 5 to 60% by weight. 1
The present invention relates to a thermoplastic elastomer composition obtained by partially cross-linking a mixture comprising 0 to 100 parts by weight of a kind polymer (E) and 5 to 100 parts by weight of a propylene-based polymer resin (F). . (B1) the ethylene content is 50 mol% or more, (b2) α
The olefin is an α-olefin having 6 to 12 carbon atoms, (b3) having a density of 0.870 to 0.935 g / cm ³ , (b4)
The lowest melting peak temperature by a differential scanning calorimeter (DSC) is 100 ° C. or more, and (b5) the cold xylene-soluble portion is 1 to 25% by weight. Hereinafter, the present invention will be described in detail.

In the present invention, the olefin copolymer rubber used in the oil-extended olefin copolymer rubber (A) includes, for example, ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene rubber, It is an amorphous random elastic copolymer containing an olefin as a main component, such as an ethylene-butene-non-conjugated diene rubber and a propylene-butadiene copolymer rubber. Among these, an ethylene-propylene-non-conjugated diene rubber is particularly preferred.
As the non-conjugated diene, dicyclopentadiene, 1,4-
Hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene and the like are preferred, and ethylidene norbornene is particularly preferred.

As a more preferred specific example, the propylene content is 10 to 55% by weight, preferably 20 to 40% by weight.
Ethylene-propylene-ethylidene norbornene copolymer rubber (hereinafter referred to as "EPDM") having a non-conjugated diene content of 1 to 30% by weight, preferably 3 to 20% by weight, such as ethylidene norbornene. Part 1
00 ° C Mooney viscosity (ML _{1 + 4} 100 ° C) is 120 ~
350, preferably 140-300. If the propylene content is less than 10% by weight, flexibility is lost and 55
If it is more than 10% by weight, the mechanical properties tend to decrease. If the content of non-conjugated diene typified by ethylidene norbornene is less than 1%, mechanical properties tend to decrease, and if it exceeds 30% by weight, injection moldability tends to decrease. If the Mooney viscosity at 100 ° C. (ML _{1 + 4} 100 ° C.) is lower than 120, the mechanical properties are lost, and if it is higher than 350, the appearance of the molded article is impaired. However, when EPDM having a Mooney viscosity of 120 to 350 is used, the mechanical properties are large, the tensile strength at break and the elongation at break are dramatically improved, and the crosslinking efficiency is increased. This leads to improved distortion. EPDM manufactured by a known method can be used.

[0008] The mineral oil-based softener used in the present invention is a high-boiling petroleum fraction incorporated for the purpose of improving processability and mechanical properties, and is a paraffinic, naphthenic or aromatic. Although there is a group system or the like, a paraffin system is preferably used. When the amount of the aromatic component is large, the contamination becomes strong, and the use for a transparent product or a bright product is limited, which is not preferable.

The oil-extended olefin-based copolymer rubber (A) is
Mineral oil-based per 100 parts by weight of olefin-based copolymer rubber
20 to 150 parts by weight of a softener, preferably 30 to 120 parts by weight
It contains parts by weight. If less than 20 parts by weight,
The fluidity of the refining TPE composition is reduced,
Workability and injection moldability are impaired. On the other hand, 150 parts by weight
When the amount increases, the plasticity increases significantly and the processability deteriorates.
In addition, the performance of the product, such as physical properties, deteriorates, which is preferable.
Not good. And oil-extended olefin copolymer rubber
100 ° C. Mooney viscosity (ML) of (A) _{1 + 4}100 ℃)
Is preferably 30 to 100, more preferably 40 to 9
0. Below 30 the mechanical properties are lost and 100
If it is higher, molding tends to be difficult.

EPDM having a Mooney viscosity of 120 to 350
When a large amount of a mineral oil-based softening agent is blended using olefin, an olefin-based TPE composition capable of simultaneously satisfying improvement of processability by securing flexibility and improvement of fluidity, and improvement of mechanical properties is obtained. I can do it. Generally, a mineral oil-based softener is used as a flowability improver in an olefin-based TPE composition.
When PDM is not used, regardless of the viscosity of EPDM, 40 parts by weight of mineral oil-based softener per 100 parts by weight of EPDM is used.
If it is added in an amount of not less than part by weight, bleeding of the softening agent occurs on the surface of the TPE composition, which is not preferable because contamination and adhesion of the product are observed. However, 100 ° C Mooney viscosity is 120-350
Using oil-extended EPDM in which 20 to 150 parts by weight of a mineral oil-based softening agent is previously blended per 100 parts by weight of EPDM,
There is no bleeding of the softener, no contamination or sticking of the product is observed, and a TPE composition having excellent physical properties such as breaking strength, breaking elongation and compression set can be obtained. Despite the large blending ratio of this mineral oil-based softener, no bleeding of the softener was observed because EPD having a high Mooney viscosity
It is considered that when M is used, the upper limit of the allowable oil extension amount of the mineral oil-based softening agent increases, and the softening agent suitably added in advance is uniformly dispersed in EPDM.

A known method is used for the oil extension method of EPDM. For example, using a device such as a roll or a Banbury mixer, a method of oil-extending by a method of mechanically kneading EPDM and a mineral oil-based softener, or adding a predetermined amount of a mineral oil-based softener to an EPDM solution, and thereafter And a method obtained by removing the solvent by a method such as steam stripping.
Among these, a preferred oil-extension method is a method using an EPDM solution, and the EPDM solution is obtained by polymerization using an EPDM solution.
The operation is easier when a solution is used.

The ethylene-α- used in the present invention
The (b1) ethylene content of the olefin copolymer (B) is 50 mol% or more, and more preferably 85 mol% or more.

The ethylene-α-olefin copolymer (B) used in the present invention comprises (b2) an α-olefin having 6 carbon atoms.
To 12 α-olefins, and the content of α-olefins is preferably 1 to 15 mol%. As the α-olefin, hexene-1,4-methyl-pentene-
1, octene-1 or the like alone or in combination.

The ethylene-α-olefin copolymer (B) used in the present invention has a (b3) density of 0.870 to 0.935 g / c.
m ³ , preferably 0.890 to 0.935 g / cm ³ , more preferably 0.910 to 0.930 g / cm ³ . (B3) is
Is less than 0.870 g / cm ^3, not preferred since the mechanical properties is reduced, also, the (b3) is 0.935 g / cm ³
Exceeding the range is not preferred because the flexibility is reduced and a balanced physical property cannot be obtained.

In the ethylene-α-olefin copolymer (B) used in the present invention, (b4) it is necessary that a minimum melting peak is observed at 100 ° C. or more in a temperature rising thermogram by a differential scanning calorimeter (DSC). It is. A plurality of melting peaks may be observed within the above temperature range. If the (b4) minimum melting peak temperature is less than 100 ° C., heat resistance is undesirably reduced.

In the ethylene-α-olefin copolymer (B) used in the present invention, (b5) a cold xylene-soluble portion (CX
S) is 1 to 25% by weight, preferably 3 to 20% by weight. When (b5) is less than 1% by weight, flexibility,
The balance of physical properties such as heat resistance was not obtained, and (b5) was 25%.
Exceeding the weight% is not preferable because the processability is reduced. The CXS of the copolymer (B) has many components having a weight average molecular chain length of 100 to 900 nm.

The ethylene-α-olefin copolymer of the component (B) is subjected to dynamic heat treatment to partially co-crosslink with the oil-extended olefin copolymer rubber of the component (A) to provide the present invention. Contributes to the improvement of processability and physical properties of the thermoplastic elastomer composition.

In order to achieve the effect of compounding the component (B),
The weight ratio (A) / (B) of the ethylene-α-olefin copolymer (B) to the oil-extended olefin copolymer rubber (A) is 40/60 to 95/5, preferably 60/40 to 90. / 10. If the content of the component (B) is less than 95/5, the purpose of adding the component (B) cannot be attained. If the content of the component (B) is more than 40/60, the fluidity of the thermoplastic elastomer composition decreases, and the moldability deteriorates. I do.

In the present invention, if necessary, at least one polymer (E) selected from polybutene, polyisobutylene and butyl rubber can be blended.
Of these, polyisobutylene is most preferred for performance and handling.

As the organic peroxide (C) for partially crosslinking a mixture comprising the oil-extended olefin copolymer rubber (A) and the ethylene-α-olefin copolymer (B), 2,5
-Dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,1,3-bis (t-butylperoxy) Isopropyl) benzene, 1,1-di (t-butylperoxy) 3,5,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (peroxybenzoyl) hexyne-3, dicumyl peroxide, etc. There is.
Of these, odor and scorch properties are particularly favorable for 2,5-
Dimethyl-2,5-di (t-butylperoxy) hexane is preferred.

The amount of the organic peroxide (C) added is 0.005 to 2.50 parts by weight based on 100 parts by weight of the total of the oil-extended olefin copolymer rubber (A) and the ethylene-α-olefin copolymer (B).
0 parts by weight, preferably in the range of 0.01 to 0.6. If the amount is less than 0.005 parts by weight, the effect of the crosslinking reaction is small,
If it exceeds 2.0 parts by weight, it is difficult to control the reaction, and it is not economically advantageous.

In producing the composition of the present invention, N, N,
N′-m-phenylene bismaleimide, toluylene bismaleimide, P-quinone dioxime, nitrobenzene,
Diphenylguanidine, trimethylolpropane, divinylbenzene, ethylene glycol dimethacrylate,
Polyfunctional compounds such as polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate are blended. By blending such a compound, a uniform and mild cross-linking reaction occurs, and it is possible to improve mechanical properties.

The amount of the crosslinking aid (D) added is 0.01 to 4.0 with respect to 100 parts by weight of the total of the oil-extended olefin copolymer rubber (A) and the ethylene α-olefin copolymer (B).
It can be selected in the range of parts by weight. Preferably 0.05-2.
0 parts by weight. If the amount is less than 0.01 part by weight, the effect is hard to appear,
Exceeding 4 parts by weight is not economically advantageous.

The propylene polymer resin (F) used in the present invention is preferably polypropylene or a copolymer resin of propylene and an α-olefin having 2 or more carbon atoms. Specific examples of the α-olefin having 2 or more carbon atoms include ethylene, 1-butene, 1-pentene, and 3-methyl-
1-butene, 1-hexene, 1-decene, 3-methyl-
There are 1-pentene, 4-methyl-1-pentene, 1-octene and the like. The melt flow rate of these polymer resins is preferably from 0.1 to 100 g / 10 minutes, and more preferably from 0.5 to 50 g / 10 minutes. 100g / 10 even if the melt flow rate is less than 0.1g / 10min
Even if it is larger than a minute, a problem arises in workability. The amount of the propylene-based polymer resin (F) in the elastomer composition according to the present invention is determined by the difference between the oil-extended olefin-based copolymer rubber (A) and the ethylene-α-olefin copolymer resin (B).
Is 5 to 100 parts by weight with respect to 100 parts by weight in total. Preferably it is 10 to 70 parts by weight.

Oil-extended olefin-based copolymer rubber (A), ethylene-α-olefin copolymer (B), organic peracid (C), crosslinking aid (D), if necessary, polymer (E), A specific production method for obtaining a thermoplastic elastomer composition by partially cross-linking a mixture composed of the propylene-based polymer resin (F) will be described below. Oil-extended olefin copolymer rubber (A), ethylene-α-olefin copolymer (B), organic peroxide (C), crosslinking aid (D), if necessary, polymer (E), and propylene The polymer resin (F) and the like are mixed at a specific ratio and dynamically heat-treated. That is, they are melted and kneaded. As the mixing and kneading apparatus, a conventionally known non-open type Banbury mixer, twin screw extruder, or the like is used. The kneading temperature may be 150 to 300 ° C. for about 1 to 30 minutes. In the production of this composition, auxiliary materials such as an inorganic filler, an antioxidant, a weathering agent, an antistatic agent, and a coloring agent can be blended as required.

The oil-extended olefin copolymer rubber (A), ethylene-α-olefin copolymer (B), crosslinking aid (D), if necessary, polymer (E), and propylene polymer resin (F ) Are preferably blended and kneaded as oil-extended olefin-based copolymer rubber (A), ethylene-α-olefin copolymer (B), crosslinking aid (D), and propylene-based polymer. A mixture with the resin (F) and, if necessary, the polymer (E) and the above-mentioned auxiliary materials are blended in a predetermined ratio, and the mixture is heated at a temperature of 150 to 250 ° C. using a known non-release type kneader such as a Banbury mixer. After sufficient kneading and homogenization, the composition is sufficiently blended with the organic peroxide (C) using an internal mixer such as a tumbler or a super mixer. Next, this blend was prepared at 200 ° C. to 300 ° C. using a twin-screw continuous extruder capable of obtaining a strong kneading force.
By dynamically heat-treating at ° C., a thermoplastic elastomer composition that becomes partially crosslinked can be obtained.

Examples of the auxiliary material include the following as specific examples of the antistatic agent. That is,
(A) cationic amines such as primary amine salts, tertiary amines, quaternary ammonium compounds, and pyridine derivatives;
(B) Sulfated oil, soap, sulfated ester oil, sulfated amide oil, sulfated salts of olefins, fatty alcohol sulfates, alkyl sulfates, fatty acid ethyl sulfonates, alkylnaphthalene sulfonates,
Alkylbenzene sulfonate, succinate sulfonate, anionic ones such as phosphate ester salts,
(C) Partial fatty acid esters of polyhydric alcohols, ethylene oxide adducts of fatty alcohols, ethylene oxide adducts of fatty acids, ethylene oxide adducts of fatty acid amino or fatty acid amides, ethylene oxide adducts of alkyl phenols, ethylene oxides of alkyl naphthols Adducts, ethylene oxide adducts of partial fatty acid esters of polyhydric alcohols, nonionic ones such as polyethylene glycol, and (d) amphoteric ones such as carboxylic acid derivatives and imidazoline derivatives are generally usable. In particular, non-ionic compounds, particularly, polyoxyethylene alkylamines, polyoxyethylene alkylamides, fatty acid esters thereof, and fatty acid esters of glycerin are preferable.

As the above antistatic agent, a single type may be used, or a mixture of two or more types may be used. Further, the compounding amount thereof is the same as that of the thermoplastic elastomer composition 1 according to the present invention.
The amount is preferably about 0.03 to 2 parts by weight, more preferably about 0.04 to 1 part by weight, per 100 parts by weight. If the compounding ratio is higher than this, bleeding to the surface and deterioration in physical properties of the thermoplastic elastomer composition occur, which is not preferable. By the addition of the antistatic agent, a molded article having flexibility and without stickiness can be obtained. In addition, the adhesion of dust and the like due to the absence of stickiness and the bleeding of the softener is reduced, and at the same time, the chargeability, which is the original function of the antistatic agent, is reduced, and the adhesion of dust due to charging is also reduced.

On the other hand, in some cases, slipperiness is desired as the property of the surface of the molded product, but higher fatty acid amides can be used for this purpose. Specific examples of the higher fatty acid amide include lauric amide, balmitic acid amide,
Saturated fatty acid amides such as stearic acid amide and behenic acid amide, unsaturated fatty acid amides such as erucic acid amide, oleic acid amide, bridic acid amide, elaidic acid amide, methylenebisstearic acid amide, methylenebisoleic acid amide, ethylenebisstearin Acid fatty acid amides and bis fatty acid amides such as ethylene bisoleic acid amide are used. Particularly preferred higher fatty acid amides are compounds having a melting point of about 70 ° C to 110 ° C. The amount of the higher fatty acid amide is preferably about 0.03 to 2 parts by weight, more preferably about 0.04 to 1 part by weight, based on 100 parts by weight of the thermoplastic elastomer composition according to the present invention. If the compounding ratio is higher than this, leaching of the higher fatty acid amide onto the surface and deterioration of the physical properties of the thermoplastic elastomer composition occur, which is not preferable.

The above-mentioned auxiliary materials can be blended at the stage of producing the elastomer composition according to the present invention, at the time of processing or at the time of using the product after processing.

In the thermoplastic elastomer composition of the present invention, inorganic fillers such as calcium carbonate, calcium silicate, clay, kaolin, talc, silica and diatomaceous earth are provided as long as the strength, moldability and rubber properties are not impaired. , Mica powder, asbestos, alumina, barium sulfate, aluminum sulfate, calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite, glass fiber,
Glass spheres, shirasu balloons, carbon fibers, etc. or coloring agents such as carbon black, titanium oxide, zinc white,
Bengal, ultramarine, navy blue, azo pigments, nitroso pigments, lake pigments, phthalocyanine pigments and the like can be blended.

In the present invention, a known antioxidant such as a phenol-based, sulfite-based, phenylalkane-based, phosphite-based or amine-based stabilizer, or a weathering agent is used in an olefin-based plastic or an olefin-based copolymer rubber. Can be blended.

(C) In order to accelerate the decomposition of the organic peroxide, trisethylamine, tributylamine, 2,3
Tertiary amines such as 4,6-tris (dimethylamino) phenol, aluminum, cobalt, panadium, copper, calcium, zirconium, manganese, magnesium,
Naphthenates such as lead and mercury, and organometallic carboxylates such as octanoate can be used together in the step of dynamically heat-treating.

The thermoplastic elastomer composition of the present invention comprises:
It can be molded with the equipment used for ordinary thermoplastics and is suitable for extrusion molding, calendar molding and especially injection molding. Since the composition obtained by the production method of the present invention is partially crosslinked, it has excellent rubber properties such as heat resistance, weather resistance, tensile properties, flexibility and rebound resilience, and has good fluidity. Therefore, when a large-sized thick product is used, a product having a good appearance without flow marks or sink marks can be obtained.

The thermoplastic elastomer composition of the present invention can be used for automobile parts such as body panels, bumper parts, side shields and steering wheels, shoe soles, sandals and other footwear, electric wire coatings, connectors and cap plugs. Products include parts, golf club grips, baseball bat grips, swimming pools, swimming fins, leisure goods such as underwater glasses, gaskets, waterproof cloths, garden hoses, belts and the like. The thermoplastic elastomer of the present invention is particularly suitable for use in large thickness products such as bumper parts.

[0036]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In addition, the test methods used for the sheet forming process and the physical property measurement in these Examples and Comparative Examples are as follows. (1) Mooney viscosity (ML _{1 + 4} 100 ° C): ASTM
D-927-57T. Equation 1 for EPDM
Was calculated.

[0037]

Log (ML ₁ / ML ₂ ) = 0.0066 (△ PHR) ML ₁ : Mooney viscosity of EPDM ML ₂ : Mooney viscosity of oil-extended EPDM ΔPHR: Oil extension amount per 100 parts by weight of EPDM

(2) Cold xylene-soluble part (CXS) 5 g of a polymer is dissolved in 500 ml of xylene and cooled slowly to room temperature. Then, the mixture was allowed to stand in a bath at 20 ° C. for 4 hours, filtered, and the filtrate was concentrated, dried, dried and weighed.

(3) Melt flow rate (MFR) According to the method defined in JIS K6760.

(4) Density According to the method specified in JIS K6760. After annealing for 1 hour in water at 100 ° C., the density was measured.

(5) Differential scanning calorimeter (DSC) DSC-7 manufactured by PerkinElmer was used. Approximately 1 cut out from a sheet of about 0.5mm thickness created by hot pressing
0 mg of the sample was placed in a sample pan for DSC measurement, and 150
Preheating at 5 ° C for 5 minutes, cooling down to 40 ° C at 1 ° C / minute,
After holding for 5 minutes, the temperature was raised to 150 ° C. at a rate of 10 ° C./min to obtain a thermogram.

(6) Extrudability: USV type 25 mmφ extruder made of Union Plastics. Full flight type screw, screw rotation speed 30
rpm. The judgment was performed on the extruded skin using a T-die. The judgment rank is as follows. ：: Excellent △: Good ×: Poor

(7) Oil bleeding property:
It was left in an oven at 0 ° C for 1 hour, and the oil bleeding on the surface of the molded product was visually observed. The judgment rank is as follows. ：: No bleed at all. Δ: Slight bleed. X: There is bleed.

Example 1 In a 5% by weight hexane solution of EPDM (ML _{1 + 4} 100 ° C. = 143, propylene content = 30% by weight, iodine value = 10), a mineral oil-based softener (Idemitsu Kosan Co., Ltd.) was used per 100 parts by weight of EPDM. , Diana Process Oil PW-380), and then 72 parts by weight of oil-extended EPDM (ML _{1 + 4} 100 ° C. = 78) desolvated by steam stripping, Vistanex MML-100 (polyisobutylene, Esso). 7 parts by weight, ethylene-hexene-
1 copolymer [Sumikacene α FZ201 manufactured by Sumitomo Chemical Co., Ltd.
−0, MFR at 190 ° C. = 2.0 g / 10 minutes, (b3)
Density 0.912 g / cm ³ , (b4) the lowest melting peak temperature by DSC is 101 ° C., and (b5) 10 parts of cold xylene soluble part
% By weight. 14 parts by weight, polypropylene (MFR =
12 g / 10 minutes, 7 parts by weight of Sumitomo Noblen FL8013, and 0.2 parts by weight of Sumilizer BM (N, N'-m-phenylenebismaleimide, manufactured by Sumitomo Chemical Co., Ltd.) were kneaded with a Banbury mixer at 170 to 200 ° C. for 7 minutes. ,
A pellet-shaped master batch was prepared using an extruder.
Next, 0.05 parts by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (hereinafter, referred to as “organic peroxide”) per 100 parts by weight of the master batch was added using a Henschel mixer. The homogenous blending operation was performed for 10 minutes. This blend was subjected to dynamic heat treatment at 220 ° C. ± 10 ° C. for 70 seconds using a twin-screw kneading extruder capable of obtaining a strong kneading force to obtain a partially crosslinked thermoplastic elastomer composition. The physical properties and moldability of the obtained elastomer composition were evaluated. The evaluation results are shown in Table 1.

Comparative Example 1 In the production of a master batch in Example 1,
Add 72 parts by weight of PDM to JSR EP-24 (ML _{1 + 4} 10
0 ° C. = 70, propylene content = 44% by weight, iodine value =
12, EPDM, manufactured by Nippon Synthetic Rubber Co., Ltd.), and the same procedure as in Example 1 was performed, except that the mineral oil-based softening agent PW-380 was changed to 21 parts by weight. Table 1 shows the evaluation results.

Examples 2-3 The elastomer composition obtained in Example 1 (intermediate composition)
FL8013 or FZ201 for 100 parts by weight
-20 was added in an amount of 20 parts by weight, and molding and physical properties were evaluated. Table 1 shows the results.

Comparative Examples 2-3 The elastomer composition (intermediate composition) obtained in Comparative Example 1
FL8013 or FZ201 for 100 parts by weight
-20 was added in an amount of 20 parts by weight, and molding and physical properties were evaluated. Table 1 shows the results.

[0048]

[Table 1]

[0049]

As described above, according to the present invention, it is possible to provide a thermoplastic elastomer composition having very little oil bleed and having excellent mechanical properties and appearance.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-28232 (JP, A) JP-A-1-103639 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 23/00-23/36

Claims (6)

(57) [Claims] 1. A 100 ° C. Mooney viscosity (ML _{1 + 4} 100
Oil-extended olefin-based copolymer rubber (A) 40 containing 20 to 150 parts by weight of a mineral oil-based softening agent per 100 parts by weight of an olefin-based copolymer rubber having a C of 120 to 350).
Organic peroxide (C) 0.0 to 95% by weight and 100% by weight of ethylene-α-olefin copolymer (B) having the following properties (b1) to (b5):
05 to 2.0 parts by weight, crosslinking aid (D) 0.01 to 4.0 parts by weight,
0-100 parts by weight of at least one polymer (E) selected from polybutene, polyisobutylene and butyl rubber, and propylene-based polymer resin (F) 5-100
A thermoplastic elastomer composition obtained by partially crosslinking a mixture consisting of parts by weight. (B1) the ethylene content is 50 mol% or more, (b2) α
The olefin is an α-olefin having 6 to 12 carbon atoms, (b3) having a density of 0.870 to 0.935 g / cm ³ , (b4)
The lowest melting peak temperature by a differential scanning calorimeter (DSC) is 100 ° C. or more, and (b5) the cold xylene-soluble portion is 1 to 25% by weight. 2. An olefin copolymer rubber comprising ethylene-
The composition according to claim 1, which is a propylene-nonconjugated diene rubber. 3. An ethylene-propylene-ethylidene norbornene copolymer rubber having a propylene content of 10 to 55% by weight and an ethylidene norbornene content of 1 to 30% by weight. Item 3. The composition according to Item 2. 4. An oil-extended olefin-based copolymer rubber (A)
00 ° C Mooney viscosity (ML _{1 + 4} 100 ° C) is 30 ~ ₁
The composition of claim 1 wherein the composition is 00. 5. An ethylene-α-olefin copolymer (B)
Is an ethylene-4-methyl-pentene-1 copolymer or an ethylene-hexene-1 copolymer. 6. The composition according to claim 1, wherein the mineral oil softener is a paraffin softener.