JP2005298682A - Thermoplastic elastomer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a thermoplastic elastomer composition which has excellent adhesiveness to polyester-based resins, excellent compression permanent set resistance in a high temperature region, excellent oil resistance, and excellent extrusion and injection moldability, so as to be used as a substitute for polyester-based thermoplastic elastomers, does not need a drying process before molded, and is inexpensive. <P>SOLUTION: This thermoplastic elastomer composition is characterized by comprising (a) 100 pts. wt. of an unsaturated nitrile-conjugated diene copolymer rubber, (b) 10 to 150 pts. wt. of a polyolefin-based resin, (c) 5 to 80 pts. wt. of a polar ethylenic copolymer, and (d) 1 to 25 pts. wt. of a crosslinking agent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a thermoplastic elastomer composition. In particular, the present invention relates to a thermoplastic elastomer composition excellent in oil resistance and compression set in a high temperature region, and excellent in moldability and adhesiveness with a polyester resin.

In recent years, thermoplastic elastomers, which are soft materials with rubber elasticity and do not require a vulcanization process, can be molded and processed like thermoplastic resins, and can be recycled. Automotive elastomers, home appliance parts, wire coatings, medical use Widely used in the fields of parts, footwear, sundries, etc.

  Among them, polyester-based thermoplastic elastomers are used in automobile CVJ boots and the like because they are excellent in bending fatigue resistance, heat resistance, and oil resistance, and are excellent in adhesion to polar resins such as polyester resins. However, polyester-based thermoplastic elastomers are expensive. Moreover, it is easy to hydrolyze and needs to be dried before molding, resulting in problems such as poor weather resistance and compression set.

  Many thermoplastic elastomer compositions obtained by dynamically crosslinking olefin resins and olefin copolymer rubbers are also known. For example, an elastomer composition in which an ethylene copolymer resin such as an ethylene-vinyl acetate copolymer and a rubber such as a halogenated butyl rubber are dynamically cross-linked is disclosed (for example, Patent Document 1). However, this is inferior in adhesiveness with a polyester resin.

JP-A 61-26641

The present inventor has excellent adhesiveness with polyester resins to be an alternative to polyester thermoplastic elastomers, is excellent in compression set and oil resistance in high temperature range, and extrusion and injection moldability, and does not require drying before molding. As a result of intensive research to obtain an inexpensive thermoplastic elastomer composition (which does not hydrolyze), the target composition is obtained by melting and kneading a nitrile rubber with an olefin thermoplastic resin and crosslinking. And the present invention has been achieved.

The present invention
(A) 100 parts by weight of copolymer rubber of unsaturated nitrile and conjugated diene,
(B) 10 to 150 parts by weight of a polyolefin resin,
A thermoplastic elastomer composition comprising 5 to 80 parts by weight of (c) polar ethylene copolymer and 1 to 25 parts by weight of (d) a crosslinking agent is provided.

In a preferred embodiment of the present invention, component (d) is a phenolic resin-based crosslinking agent.

In another preferred embodiment of the present invention, the thermoplastic elastomer composition further comprises (e) a crosslinking accelerator in an amount of 20 parts by weight or less.

In another preferred embodiment of the invention, component (e) is zinc oxide and the amount is 0.05 to 20 parts by weight.

In another preferred embodiment of the invention, component (e) is tin chloride and the amount is 0.1 to 10 parts by weight.

  Moreover, this invention provides the molded object characterized by comprising the said thermoplastic elastomer composition.

  Furthermore, the present invention provides a sealing member for an automobile CVJ boot, comprising the thermoplastic elastomer composition.

Furthermore, the present invention provides an automobile fuel tube comprising the above thermoplastic elastomer composition.

Furthermore, the present invention provides a composite molded article comprising the thermoplastic elastomer composition and a polyester resin.

  The thermoplastic elastomer composition of the present invention is excellent in oil resistance and compression set in a high temperature region, and is excellent in molding processability and adhesion to a polyester resin.

(A) Copolymer rubber of unsaturated nitrile and conjugated diene:
Component (a) used in the present invention is a copolymer rubber of an unsaturated nitrile and a conjugated diene, and the content of the unsaturated nitrile is preferably 25% by weight or more, more preferably 30 to 50% by weight. When the unsaturated nitrile content is less than 25% by weight, the oil resistance is deteriorated.
The component (a) preferably has a Mooney viscosity ML _{1 + 4} (100 ° C.) of 20 to 120, more preferably 40 to 100. When Mooney viscosity ML _{1 + 4} (100 ° C.) is less than 20, rubber elasticity is poor, and when it exceeds 120, processability is inferior.

  Here, specific examples of the unsaturated nitrile include α, β-unsaturated nitriles, and examples include acrylonitrile and methacrylonitrile, with acrylonitrile being preferred. The α, β-unsaturated nitrile can be used alone or in combination of two or more. Examples of the conjugated diene include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, chloroprene and the like, among which 1,3-butadiene and isoprene are preferable. . Conjugated dienes can be used singly or in combination of two or more.

Component (a) can be produced by a conventional method. For example, in the case of acrylonitrile-butadiene copolymer, it is preferably produced by emulsion polymerization, and the microstructure of the butadiene unit is, for example, cis-1,4 structure 10-15%, trans-1,4 structure 65-85% and It can consist of 15-20% vinyl structure.
Examples of the synthesis catalyst include transition metal catalysts such as Ni, Co, and Ti compounds.

  The component (a) used in the thermoplastic elastomer composition of the present invention includes, in addition to the acrylonitrile-butadiene copolymer rubber (NBR), acrylonitrile-butadiene-isoprene copolymer rubber (NBIR), acrylonitrile-isoprene copolymer. Examples thereof include combined rubber (NIR), acrylonitrile-butadiene-butoxyacrylate copolymer rubber, acrylonitrile-butadiene-acrylic acid copolymer rubber, acrylonitrile-butadiene-methacrylic acid copolymer rubber, and partially crosslinked NBR is also preferable. Used.

(B) Polyolefin resin:
Component (b) used in the present invention is a polyolefin-based resin, for example, a homopolymer of olefins such as ethylene, propylene, butene-1, 4-methylpentene-1, or a copolymer mainly composed of these olefins. Is mentioned. The component (b) is synthesized by polymerizing the above monomers by an ordinary method, and examples of the catalyst used at that time include Ziegler-Natta catalysts and metallocene catalysts.

  Preferable examples of the component (b) include ethylene or propylene homopolymers or crystalline copolymers mainly composed of ethylene or propylene. Specifically, high density polyethylene, low density polyethylene, ethylene Examples thereof include crystalline ethylene copolymers such as α-olefin copolymers, crystalline propylene copolymers such as propylene homopolymers and propylene / α-olefin copolymers. Here, the α-olefin used in the copolymer of ethylene or propylene is an α-olefin having 3 to 10 carbon atoms, such as propylene, butene-1, hexene-1, 4-methylpentene-1, 3-methyl. Penten-1, octene-1, etc. are mentioned. Crystalline copolymers mainly composed of ethylene or propylene include crystalline ethylene polymers such as ethylene / butene-1 copolymer, ethylene / hexene-1 copolymer, and ethylene / octene-1 copolymer. , Crystals of propylene / ethylene random copolymer, propylene / ethylene block copolymer, propylene / ethylene random block copolymer, propylene / butene-1 copolymer, propylene / ethylene / butene-1 terpolymer A propylene-based polymer. More preferably, as the component (b), a crystalline polypropylene copolymer and a crystalline ethylene copolymer synthesized with a metallocene catalyst are used. Particularly preferred is a crystalline polypropylene copolymer.

Component (b) has a melting point by DSC of preferably 30 to 180 ° C, more preferably 40 to 170 ° C. Here, the melting point by DSC is the peak top melting point obtained by a differential scanning calorimeter (DSC). Specifically, using DSC, a sample amount of 10 mg is taken, held at 190 ° C. for 5 minutes, and then −10 Crystallization is performed at a rate of temperature decrease of 10 ° C / min up to 10 ° C, held at -10 ° C for 5 minutes, and then measured to 200 ° C at a rate of temperature increase of 10 ° C / min.

The compounding quantity of a component (b) is 10-150 weight part with respect to 100 weight part of component (a), Preferably it is 20-100 weight part. If it exceeds 150 parts by weight, the compression set, flexibility and adhesion to polyester of the resulting thermoplastic elastomer composition will deteriorate. If it is less than 10 parts by weight, the moldability and manufacturability of the resulting thermoplastic elastomer composition deteriorate.

(C) Polar ethylene copolymer The component (c) used in the present invention includes (c-1) a copolymer of ethylene and a monomer represented by formula (I) or (II), and (C-2) An ethylene ionomer resin is included.
^{_{CH 2 = C (R 1)}} -COOR 2 ... (I)
^{_{CH 2 = C (R 1)}} -OCOR 2 ... (II)
(Wherein R ¹ represents hydrogen or a methyl group, and R ² represents hydrogen or an alkyl group having 1 to 10 carbon atoms)

(C-1) Copolymer of ethylene and a monomer represented by formula (I) or (II):
Examples of the monomer represented by the formula (I) or (II) include (meth) acrylic acid, vinyl acetate, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, isobutyl acrylate, methacryl Examples include butyl acid.

  In the component (c-1), the content of the monomer represented by the formula (I) or (II) is preferably 10% by weight or more, more preferably 10 to 50% by weight, and still more preferably 20 to 50%. % By weight, particularly preferably 25-45% by weight. If the said content is less than 10 weight%, the compatibility of a component (a) and a component (b) will deteriorate. When it exceeds 50 weight%, the compression set of the thermoplastic elastomer composition obtained will deteriorate.

(C-2) Ethylene ionomer resin:
Component (c-2) is one of the carboxyl groups of the ethylene / α, β-unsaturated carboxylic acid copolymer or ethylene / α, β-unsaturated carboxylic acid / α, β-unsaturated carboxylic acid ester copolymer. The part is neutralized and / or crosslinked with metal ions.

  The α, β-unsaturated carboxylic acid constituting the copolymer is preferably one having 3 to 8 carbon atoms, more preferably acrylic acid, methacrylic acid, maleic acid, fumaric acid, maleic anhydride. Etc. are used. The α, β-unsaturated carboxylic acid ester is preferably one having 4 to 8 carbon atoms, more preferably methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, isobutyl acrylate. Butyl methacrylate, dimethyl phthalate and the like are used. As the α, β-unsaturated carboxylic acid, acrylic acid and methacrylic acid are particularly preferably used, and as the α, β-unsaturated carboxylic acid ester, isobutyl acrylate is particularly preferably used.

The metal ion is a metal ion having a valence of 1 to 3, particularly a metal ion having a valence of 1 to 3 of groups I, II, III, IV and VII in the periodic table. For example, Na ⁺ , K ⁺ , Li ⁺ , Zn ^{++ and the} like can be mentioned. These metal ions may be a mixed component of two or more kinds, or may be a mixed component with ammonium ions. Of these metal ions, Zn ⁺⁺ and Na ⁺ are particularly preferable.

  Specific examples of component (c) include ethylene / vinyl acetate copolymer (EVA), ethylene / methyl methacrylate copolymer (EMMA), ethylene / ethyl acrylate copolymer (EEA), and ethylene / methyl acrylate copolymer. (EMA), ethylene / acrylic acid copolymer (EAA), ethylene / methacrylic acid copolymer (EMAA), and ethylene ionomer resin in which the molecules of ethylene / methacrylic acid copolymer are crosslinked with metal ions. Of these, ethylene / vinyl acetate copolymer (EVA) and ethylene / methacrylic acid copolymer (EMAA) are preferable.

  Component (c) preferably has an MFR (190 ° C., 21.18 N load) of 1 dg / min or more, more preferably 10 to 50 dg / min. If the MFR is less than 1 dg / min, the moldability of the resulting thermoplastic elastomer composition deteriorates. When MFR exceeds 50 dg / min, the compression set of the thermoplastic elastomer composition obtained will deteriorate. Here, MFR is a value measured in accordance with JIS K-6924 (JIS K-6730 has been abolished and shifted) (190 ° C., 21.18 N).

  Examples of the product of component (c) include EVAFLEX P-3307 (EV150) (MFR 30 dg / min, vinyl acetate content 33 wt%, tensile strength 9 MPa) manufactured by Mitsui DuPont Polychemical Co., Ltd., P-2807 (EV250) ( MFR 15 dg / min, vinyl acetate content 28 wt%, tensile strength 14 MPa), P-2805 (EV 260) (MFR 6 dg / min, vinyl acetate content 28 wt%, tensile strength 22 MPa), P-2505 (EV 360) (MFR 2 dg / Min, vinyl acetate content 25 wt%, tensile strength 27 MPa), P-1907 (EV450) (MFR 15 dg / min, vinyl acetate content 19 wt%, tensile strength 13 MPa), and the like. Among these, EVAFLEX P-3307 (EV150) is preferable.

  The compounding quantity of a component (c) is 5-80 weight part with respect to 100 weight part of component (a), Preferably it is 10-50 weight part. If the blending amount of component (c) exceeds 80 parts by weight, the compression set and oil resistance of the resulting thermoplastic elastomer composition deteriorate, and if it is less than 5 parts by weight, the compatibility between component (a) and component (b) Therefore, the molding appearance of the resulting thermoplastic elastomer composition and the adhesion to polyester deteriorate.

(D) Crosslinking agent:
The component (d) used in the present invention is a crosslinking agent capable of crosslinking the component (a), and various crosslinking agents can be used. For example, a phenol resin type crosslinking agent, a sulfur type crosslinking agent, an organic peroxide, etc. are mentioned, and a phenol resin type crosslinking agent is especially preferable.

（式中、Ｑは、−ＣＨ₂−及び−ＣＨ₂−Ｏ−ＣＨ₂−から成る群から選ばれる二価基であり、ｍは０又は１乃至２０の正の整数であり、Ｒ’は有機基である）を有するフェノール樹脂およびその末端水酸基が臭素化されたフェノール樹脂である。好ましくは、Ｑは、二価基−ＣＨ₂−Ｏ−ＣＨ₂−であり、ｍは０又は１乃至１０の正の整数であり、Ｒ’は２０未満の炭素原子を有する有機基である。なおより好ましくは、ｍは０又は１乃至５の正の整数であり、Ｒ’は４乃至１２の炭素原子を有する有機基である。 The phenolic resin-based crosslinking agent is preferably represented by the general formula (I):

Wherein Q is a divalent group selected from the group consisting of —CH ₂ — and —CH ₂ —O—CH ₂ —, m is 0 or a positive integer of 1 to 20, and R ′ is And a phenol resin having a terminal hydroxyl group brominated. Preferably, Q is a divalent group —CH ₂ —O—CH ₂ —, m is 0 or a positive integer from 1 to 10, and R ′ is an organic group having less than 20 carbon atoms. Even more preferably, m is 0 or a positive integer from 1 to 5, and R ′ is an organic group having 4 to 12 carbon atoms.

  Among the phenol resins, alkylphenol formaldehyde resins, methylolated alkylphenol resins, and brominated alkylphenol resins are more preferable, and alkylphenol formaldehyde resins are particularly preferable.

  The phenolic resin can be produced by a conventional method, for example, by condensing an alkyl-substituted phenol or unsubstituted phenol with an aldehyde, preferably formaldehyde, in an alkaline medium, or condensing a bifunctional phenol dialcohol. Can be manufactured. Or a commercially available phenol resin can also be used.

Examples of products of the above-mentioned phenolic resin-based crosslinking agent include tackolol 201 (alkylphenol formaldehyde resin, manufactured by Taoka Chemical Industry Co., Ltd.), tackolol 250-I (brominated alkylphenol formaldehyde resin having a bromination rate of 4%, manufactured by Taoka Chemical Industry Co., Ltd.), Tactrol 250-III (brominated alkylphenol formaldehyde resin, manufactured by Taoka Chemical Industry Co., Ltd.), PR-4507 (manufactured by Gunei Chemical Industry Co., Ltd.), Vulcaresat 510E (manufactured by Hoechst), Vulkaresat 532E (manufactured by Hoechst), Vulkarensen E (manufactured by Hoechst) ), Vulkaresen 105E (manufactured by Hoechst), Vulcaresen 130E (manufactured by Hoechst), Vulcaresol 315E (manufactured by Hoechst), A berol ST 137X (manufactured by Rohm & Haas), Sumilite Resin PR-22193 (manufactured by Sumitomo Durez), Symform-C-100 (manufactured by Anchor Chem.), Symform-C-1001 (manufactured by Anchor Chem.), Tamanoru 531 (Manufactured by Arakawa Chemical Co., Ltd.), Schenectady SP1059 (manufactured by Schenectady Chem.), Schenectady SP1045 (manufactured by Schencchemy Chem.), CRR-0803 (manufactured by U.C.C.), Schemadedy SP1055 (manufactured by Schemady Chem.) Schenectady SP1056 (manufactured by Schenectady Chem.), CRM-0803 (manufactured by Showa Union Synthesis Co., Ltd.), Vulk dur A (Bayer Corp.) can be cited, Tackirol 201 (alkylphenol formaldehyde resin) Among them are preferably used.

The compounding quantity of a component (d) is 1-25 weight part with respect to 100 weight part of component (a), Preferably it is 2-15 weight part. If the amount of component (d) exceeds the upper limit, the manufacturability and moldability of the resulting thermoplastic elastomer composition will deteriorate. On the other hand, if it is less than the lower limit, the compression set and oil resistance of the resulting thermoplastic elastomer composition deteriorate.
(E) Crosslinking accelerator:
The component (e) is used as an optional component in order to improve the function of the component (a) as a crosslinking agent more effectively. Examples of the component (e) include zinc oxide, magnesium oxide and tin dichloride, and these can be used alone or in combination of two or more.

The amount of component (e), when blended, is 20 parts by weight or less with respect to 100 parts by weight of (a).

When zinc oxide is used as the component (e), a metal stearate salt or the like can be used in combination as a dispersant. Zinc oxide is blended in an amount of 20 parts by weight or less, preferably 0.05 to 18 parts by weight, more preferably 0.1 to 15 parts by weight with respect to 100 parts by weight of component (a). When the upper limit is exceeded, manufacturability and extrusion / injection moldability of the resulting thermoplastic elastomer composition deteriorate.

When tin chloride is used as the component (e), the amount is 10 parts by weight or less, preferably 0.1 to 8 parts by weight, more preferably 0.5 to 6 parts by weight with respect to 100 parts by weight of the component (a). It is blended with. When the upper limit is exceeded, manufacturability and extrusion / injection moldability of the resulting thermoplastic elastomer composition deteriorate.

In the composition of the present invention, a heat stabilizer, an antioxidant, a light stabilizer, an ultraviolet absorber, a crystal nucleating agent, an antiblocking agent, a sealability improver, a stearin, and the like, as long as the object of the present invention is not impaired. Release agents such as acids and silicone oils, lubricants such as polyethylene wax, colorants, pigments, inorganic fillers (alumina, talc, calcium carbonate, mica, wollastonite, clay), foaming agents (organic and inorganic), Flame retardants (hydrated metal compounds, red phosphorus, ammonium polyphosphate, antimony, silicone) and the like can be blended.

Examples of the antioxidant include 2,6-di-tert-p-butyl-p-cresol, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol, 4,4- Examples thereof include phenolic antioxidants such as dihydroxydiphenyl and tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, phosphite antioxidants, thioether antioxidants, and the like. Of these, phenolic antioxidants and phosphite antioxidants are particularly preferred.

The thermoplastic elastomer composition of the present invention can be produced by melting and kneading the above components (a) to (d) and, if necessary, other components simultaneously or in any order. The method of melt kneading is not particularly limited, and generally known methods can be used. For example, a single screw extruder, a twin screw extruder, a roll, a Banbury mixer, or various kneaders can be used. Moreover, the said operation can also be performed continuously by using a moderate L / D twin-screw extruder, a Banbury mixer, a pressure kneader, etc. Here, the temperature of melt kneading is preferably 160 to 200 ° C.

  The thermoplastic elastomer composition of the present invention thus obtained is excellent in moldability and oil resistance and compression set in a high temperature region. Therefore, it is useful as an automobile fuel tube. Moreover, since the thermoplastic elastomer composition of the present invention is excellent in heat-fusibility with a polyester resin, it is useful as an automobile CVJ boot member, and particularly as a seal member thereof. These molded articles can be produced by extrusion or injection molding of the thermoplastic elastomer composition of the present invention.

  Next, the present invention will be described in detail using Examples and Comparative Examples, but the present invention is not limited to the following Examples. The test methods and raw materials used in the examples and comparative examples are as follows.

1. Test method (1) Specific gravity: Based on JIS K7112, the test piece was measured using a 1 mm thick press sheet.
(2) Hardness: In accordance with JIS K 7215, the test piece was measured with durometer hardness / type A using a 6.3 mm thick press sheet.
(3) Tensile strength, 100% elongation stress, and elongation: In accordance with JIS K 6301, a 1 mm thick press sheet was punched into a No. 3 dumbbell mold and used. The tensile speed was 500 mm / min.
(4) Compression set: In accordance with JIS K 6262, a 6.3 mm thick press sheet was used as a test piece. The measurement was performed at 120 ° C. for 22 hours under the condition of 25% deformation.
(5) Volume swelling ratio: In accordance with JIS K 6258, the test piece used was a 2 mm thick press sheet, and the volume swelling ratio after being immersed in IRM # 902 oil at 120 ° C. for 72 hours was measured.
(6) Compatibility: A sheet of 130 mm × 130 mm × 2 mm (gate shape: film gate, gate size: 130 × 0.5 mm) was injection molded with a 120 t injection molding machine, and acrylonitrile-butadiene copolymer rubber (NBR). The compatibility between the powder and polypropylene (PP) was judged. The molding conditions are as follows.
Molding temperature 220 ° C
Mold temperature 30 ℃
Injection speed 55mm / sec Injection pressure 1400kg / cm ²
Holding pressure 400kg / cm ²
Injection time: 5 seconds Cooling time: 20 seconds ○: The sheet surface is smooth ×: NBR powder is present on the sheet surface, and it is crushed.
(7) Extrudability: A 50 mm × 1 mm sheet was extruded using a 40 mm extruder, and the drawdown property, surface appearance and shape were observed and evaluated according to the following criteria.
Barrel temperature 200 ℃
Die temperature 200 ℃
Die shape 50mm × 1mm
Screw shape Full flight L / D: 22
Screw rotation speed 40rpm
○: Good (no drawdown, good surface appearance)
X: bad (there is a drawdown and the surface appearance is bad)
(8) Injection moldability: A 130 mm × 130 mm × 2 mm sheet (gate shape: film gate, gate size: 130 × 0.5 mm) was injection molded with a 120 t injection molding machine, and the appearance (whether flow marks and sink marks were generated) ) Was visually observed and evaluated according to the following criteria. The molding conditions are as follows.
Molding temperature 220 ° C
Mold temperature 30 ℃
Injection speed 55mm / sec Injection pressure 1400kg / cm ²
Holding pressure 400kg / cm ²
Injection time 5 seconds Cooling time 20 seconds ○: No flow mark or sink mark ×: Flow mark or sink mark occurs (9) Necessity of drying before molding: Extrusion molding (7) and injection molding (8) It was evaluated whether or not drying was necessary before performing.
○: No difference in moldability even if it is dried or not ×: If it is not dried, the surface of the molded product may be roughened due to evaporation of moisture (in the case of extrusion molding), or silver streaks may occur (injection molding) in the case of).
(10) Adhesiveness with polyester: A 2 mm thick sheet is prepared by injection molding in the same manner as in (8) above, and a 2 mm thick sheet of polyester prepared by the same injection molding is superimposed on the 3 mm thick metal. The film was put into a heat resistant frame, pressed at 220 ° C. for 1.5 minutes, and pressed for 1 minute (50 kg / cm 2) to a thickness of 3 mm for adhesion. The two sheets were partially masked during bonding, the two sheets were peeled off from the part, and the peeled state was observed to evaluate the adhesiveness according to the following criteria.
○: Even if the two sheets are pulled by hand, the two sheets are not peeled off, or even if they are peeled off, the material breaks down, and a part of the material remains adhered to the polyester sheet.
X: It peels cleanly at the interface between the two sheets.
(11) Manufacturability: Each component was kneaded using a pressure kneader mixer having a capacity of 3 L (kneading at 180 ° C. for 5 to 20 minutes), and evaluated according to the following criteria.
○: The thermoplastic kneaded material was discharged.
X: The discharged material is not thermoplastic.

2. Raw material component (a): PNC-38 (manufactured by JSR Corporation), acrylonitrile-butadiene copolymer rubber (NBR), nitrile content 38%, Mooney viscosity ML _{1 + 4} (100 ° C.) = 60
Comparative component (a): CHLOROBUTYL 1066 (manufactured by JSR Corporation), chlorinated butyl rubber, specific gravity 0.92, ML _{1 + 8} (100 ° C.) = 38, chlorine content 1.2%
Component (b): Novatec BC08AHA (manufactured by Nippon Polychem Co., Ltd.), propylene-ethylene block copolymer, density: 0.902 g / cm ³ , hardness: 94 (Shore A), MFR (230 ° C., 21.18 N load): 80 dg / min, weight average molecular weight: 100,000
Comparative component (b): Nordel IP 4770R (manufactured by DuPont Dow Elastomer), EPDM
Component (c): EV150, manufactured by Mitsui DuPont Polychemical Co., Ltd., ethylene-vinyl acetate copolymer (EVA), MFR 30 dg / min, vinyl acetate content 33% by weight, tensile strength 9 MPa
Component (d): Tackirol 201, manufactured by Taoka Chemical Industry Co., Ltd., alkylphenol formaldehyde resin component (e-1): zinc oxide, zinc oxide two types manufactured by Sakai Chemical Co., Ltd. (e-2): first chloride Tin (anhydrous type), polyester thermoplastic elastomer manufactured by Nippon Chemical Industry Co., Ltd .: Hytrel 4047 (manufactured by Toray DuPont)

Examples 1-3 and Comparative Examples 1-9
The components shown in Tables 1 and 2 were charged in a 3 L capacity pressure kneader type mixer in the amounts (parts by weight) shown in the above table, melt-kneaded at a kneading temperature of 180 ° C., and pelletized. Next, the obtained pellet was injection-molded or press-molded to prepare a test piece, which was used for each test. The evaluation results are shown in Tables 1 and 2.

As shown in Table 1, the thermoplastic elastomer composition of the present invention is excellent in oil resistance and compression set in a high temperature region, and is excellent in moldability and adhesion to a polyester resin.
On the other hand, as shown in Table 2, the composition of Comparative Example 1 in which component (b) is less than the lower limit is inferior in moldability and manufacturability. The composition of Comparative Example 2 in which the component (b) exceeds the upper limit is inferior in flexibility, compression set, and adhesion to polyester. Moreover, the composition of Comparative Example 3 that does not contain the component (c) is inferior in manufacturability, compatibility, moldability, and adhesion to polyester. When the component (c) exceeds the upper limit, oil resistance and compression set are deteriorated (Comparative Example 4). Further, the composition of Comparative Example 5 in which component (d) is less than the lower limit is inferior in compression set and oil resistance, and the composition of Comparative Example 6 in which component (d) exceeds the upper limit is manufacturable and molded. Inferior to sex. The composition of Comparative Example 7 uses chlorinated butyl rubber in place of component (a), and is inferior in compression set and oil resistance, and inferior in adhesion to a polyester resin. The composition of Comparative Example 8 uses ethylene-propylene-nonconjugated diene copolymer rubber (EPDM) instead of component (b). This composition has good adhesion to the polyester resin, but is inferior in moldability and manufacturability. Comparative Example 9 compares the composition of the present invention with a polyester-based thermoplastic elastomer. Polyester thermoplastic elastomers are expensive and need to be dried before molding (easily hydrolyzable) and inferior in compression set.

Claims (9)

(A) 100 parts by weight of copolymer rubber of unsaturated nitrile and conjugated diene,
(B) 10 to 150 parts by weight of a polyolefin resin,
A thermoplastic elastomer composition comprising (c) 5 to 80 parts by weight of a polar ethylene copolymer and (d) 1 to 25 parts by weight of a crosslinking agent. The thermoplastic elastomer composition according to claim 1, wherein the component (d) is a phenol resin-based crosslinking agent. The thermoplastic elastomer composition according to claim 1 or 2, further comprising (e) a crosslinking accelerator in an amount of 20 parts by weight or less. The thermoplastic elastomer composition according to claim 3, wherein the component (e) is zinc oxide and the amount thereof is 0.05 to 20 parts by weight. The thermoplastic elastomer composition according to claim 3, wherein the component (e) is tin chloride and the amount thereof is 0.1 to 10 parts by weight. A molded article comprising the thermoplastic elastomer composition according to claim 1. A sealing member for an automobile CVJ boot, comprising the thermoplastic elastomer composition according to claim 1. An automobile fuel tube comprising the thermoplastic elastomer composition according to claim 1. A composite molded body comprising the thermoplastic elastomer composition according to claim 1 and a polyester resin.