JP4231368B2 - Thermoplastic elastomer composition - Google Patents

Description

  The present invention relates to a thermoplastic elastomer composition, particularly excellent in flexibility, compression set in a high temperature region, excellent oil resistance, excellent compatibility, bending whitening resistance, bending fatigue resistance, oil bleed resistance, The present invention relates to a thermoplastic elastomer composition excellent in extrusion moldability and injection moldability.

  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 parts, home appliance parts, wire coating materials, medical Widely used in fields such as parts, footwear and sundries.

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

In addition, an elastomer composition obtained by hydrogenating an intramolecular double bond of a block copolymer of styrene and a conjugated diene in these elastomers is further improved as an elastomer having improved heat aging resistance (thermal stability) and weather resistance. Widely used.
However, thermoplastic elastomer compositions using these hydrogenated block copolymers still have problems with rubber-like properties such as oil resistance, heat-press deformation rate (compression set) and rubber elasticity at high temperatures. In order to improve this point, a crosslinked product obtained by crosslinking a composition containing a hydrogenated derivative of the block copolymer has been proposed (see, for example, Patent Documents 1 to 5).
However, the crosslinked composition of the hydrogenated block copolymer disclosed in the above publication has a problem that the compression set is still insufficient at a high temperature, particularly at 100 ° C. or more, and the mechanical strength tends to decrease. The current level of performance has not reached the performance level required for vulcanized rubber applications. In extrusion molding, since the melt tension at a high temperature is low, shape retention is deteriorated, and in injection molding, there are many problems on the molding surface such as a longer molding cycle (molding time).

Many thermoplastic elastomer compositions obtained by dynamically crosslinking olefin resins and olefin copolymer rubbers are also known. Among these, an elastomer composition obtained by dynamically crosslinking an ethylene copolymer resin such as an ethylene-vinyl acetate copolymer and a rubber such as a halogenated butyl rubber (for example, see Patent Document 6), an ethylene-vinyl acetate copolymer. An elastomer composition containing an EPDM rubber dynamically vulcanized in the presence of an ethylene copolymer resin such as a coalescence (see, for example, Patent Document 7), an ethylene-hexene copolymer, and an ethylene-butene copolymer. Vulcanizing a mixture of an elastomer composition (for example, see Patent Document 8) containing a dynamically vulcanized halogenated butyl rubber, an α-monoolefin copolymer rubber such as EPDM, and crystalline polypropylene The composition containing the thermoplastic elastomer obtained by this and a low density ethylene-alpha-olefin copolymer (for example, refer patent document 9). , Obtained by blending a vulcanized EPDM and a crystalline ethylene polymer, and further vulcanizing a molded article (see, for example, Patent Document 10) subjected to a free radical crosslinking treatment, and a mixture of EPDM and crystalline polypropylene. Composition containing thermoplastic elastomer, high-density polyethylene and low-density polyethylene (see, for example, Patent Document 11), crosslinkable rubber such as terpolymer rubber, thermoplastic resin such as polypropylene, and processing of highly fluid linear polyolefin An elastomer obtained by crosslinking a mixture of additives (see, for example, Patent Document 12) has been disclosed, but this composition was also poor in high-temperature compression set and was not satisfactory in practice.
In addition, a thermoplastic vulcanized rubber composition containing semi-crystalline polypropylene as an essential component for rubber and thermoplastic random ethylene copolymer has been disclosed in order to improve toughness at the time of pulling, but a large amount of semi-crystalline polypropylene is disclosed. Therefore, there is a problem that the balance between flexibility, bleed resistance, and high temperature compression set is poor. (See Patent Document 13.)
However, in the olefin resin-based thermoplastic elastomer composition disclosed in the above publication, it is necessary to use a rubber having a high Mooney viscosity in order to improve high temperature compression set. There was a problem that the moldability was inferior. In addition, the dynamically cross-linked elastomer composition of ethylene resin synthesized with other than EPDM and LLDPE with a density exceeding 0.910 g / cm ³ or a single site catalyst (multisite catalyst) is kneaded at a low temperature of about 80 ° C. It cannot be produced, the crosslinking reaction precedes the resin kneading, a uniform thermoplastic composition cannot be easily obtained, and the deterioration of the resin and softening agent due to the high resin temperature causes bleeding and blooming. There was a problem. In addition, the compatibility is very poor, so it is inferior in bending whitening resistance, bending fatigue resistance, and oil bleed resistance, and still has insufficient compression set at high temperatures, particularly at 100 ° C or higher, resulting in a decrease in mechanical strength. There is a problem that it is easy, and the current level of performance has not reached the performance level required for vulcanized rubber applications.
Furthermore, in the above prior art, the addition amount of the crosslinking accelerator is 50 to 200 parts by weight with respect to 100 parts by weight of the crosslinking agent, and a very large addition amount is disclosed. The present condition is that the compression set at a high temperature does not reach the performance level conventionally required for vulcanized rubber applications.
In addition, the olefin-based elastomer is limited to a hardness of 50 to 90 A, and has a disadvantage that it cannot be used particularly for applications that require flexibility.
In addition, when adding a softener for rubber to an olefin-based elastomer to obtain flexibility, the softener bleeds from the molded product and the oil absorbability is poor at the time of manufacture. . In particular, those showing flexibility of 50 A or less were not practical because the blistering of the softening agent from the molded product was remarkable and the extrusion / injection moldability was poor.

          JP 59-6236 A           JP-A 63-57662           Japanese Patent Publication No. 3-49927           Japanese Patent Publication No. 3-11291           Japanese Patent Publication No. 6-13628           Japanese Examined Patent Publication No. 61-26641           Japanese Patent Laid-Open No. 2-113046           JP-A-3-17143           JP-A-3-234744           Japanese Patent Laid-Open No. 1-132643           JP-A-2-255733           JP 2002-220493 A           JP 2001-524563 A

  In view of the above problems, the object of the present invention is particularly excellent in oil resistance, no bleed of a softening agent, excellent in flexibility, and can obtain good compression set at high temperatures even with rubber having a low Mooney viscosity. A thermoplastic elastomer composition excellent in extrusion and injection moldability, in which compression set in a high temperature region for a long period (48 hours or more) is specifically improved by using an amount of a crosslinking agent and a very small amount of a crosslinking accelerator. It is to provide.

  As a result of intensive studies to achieve the above object, the present inventor has obtained an ethylene copolymer rubber as a crystalline olefin resin, a copolymer of an aromatic vinyl compound and a conjugated diene compound, and a hydrogenated aromatic. A copolymer of a vinyl compound and a conjugated diene compound, at least one polymer selected from the group consisting of hydrogenated conjugated diene compound polymers, melt kneaded with a softener for non-aromatic rubber, a specific crosslinking agent and a crosslinking agent It has been found that a thermoplastic elastomer composition excellent in flexibility, free from rubber softener bleed, and excellent in oil resistance, compression set and molding processability can be obtained by crosslinking with a specific amount of accelerator. The present invention has been completed.

  The thermoplastic elastomer composition of the present invention is a thermoplastic elastomer composition having excellent oil resistance, flexibility, no bleed, excellent compression set in a long-term high temperature range, and excellent extrusion and injection moldability. It can be suitably used as a material for brake parts centered on parts, parts for hydraulically or pneumatically operated devices, elastic polymer parts and the like.

That is, according to the first invention of the present invention, (a) 100 parts by weight of ethylene copolymer rubber,
(B) 20 to 250 parts by weight of a crystalline olefin resin,
(C) 2 to 30 parts by weight of a crosslinking agent (d) 0.01 to 0.5 parts by weight of a crosslinking accelerator (e) 10 to 300 parts by weight of a softener for non-aromatic rubber (f) conjugated with an aromatic vinyl compound A copolymer with a diene compound,
A copolymer of a hydrogenated aromatic vinyl compound and a conjugated diene compound;
5 to 100 parts by weight of at least one polymer selected from the group consisting of hydrogenated conjugated diene compound polymers,
There is provided a thermoplastic elastomer composition characterized in that

According to the second invention of the present invention, in the first invention, (a) the ethylene copolymer rubber has a Mooney viscosity of 10 to 180 (ML _{1 + 4} , 125 ° C.). Elastomeric compositions are provided.

  According to the third invention of the present invention, in the first or second invention, (c) the cross-linking agent is at least one cross-linking agent selected from the group consisting of a phenol resin and a brominated phenol resin. A thermoplastic elastomer composition is provided.

  According to a fourth aspect of the present invention, there is provided a thermoplastic elastomer composition characterized in that in any one of the first to third aspects, (c) the crosslinking agent is an alkylphenol formaldehyde resin.

  According to a fifth invention of the present invention, in any one of the first to fourth inventions, (d) at least one crosslinking selected from the group consisting of zinc oxide, magnesium oxide and tin dichloride is used as the crosslinking accelerator. A thermoplastic elastomer composition is provided that is an accelerator.

  According to a sixth aspect of the present invention, there is provided the thermoplastic elastomer composition according to any one of the first to fifth aspects, wherein (d) the crosslinking accelerator is zinc oxide. .

  According to the seventh invention of the present invention, in any one of the first to sixth inventions, (h) an organic peroxide is further added in an amount of 0.01 to 0 to 100 parts by weight of the component (a). A thermoplastic elastomer composition characterized by containing .5 parts by weight is provided.

  According to an eighth aspect of the present invention, there is provided a molded body characterized by being molded from the thermoplastic elastomer composition according to any one of the first to seventh aspects.

  Hereinafter, the components of the thermoplastic elastomer composition of the present invention, the production of the thermoplastic elastomer composition, and the uses of the thermoplastic elastomer composition will be described in detail.

1. Component of thermoplastic elastomer composition (a) Ethylene copolymer rubber The ethylene copolymer rubber (a) used in the thermoplastic elastomer composition of the present invention includes ethylene and propylene, 1-butene, 1-pentene and the like. And an ethylene copolymer rubber formed by copolymerizing these and an non-conjugated diene.

  Examples of the non-conjugated diene include 5-ethylidene-2-norbornene (ENB), 1,4-hexadiene, 5-methylene-2-norbornene (MNB), 1,6-octadiene, 5-methyl-1,4-hexadiene. 3,7-dimethyl-1,6-octadiene, 1,3-cyclopentadiene, 1,4-cyclohexadiene, tetrahydroindene, methyltetrahydroindene, dicyclopentadiene, 5-isopropylidene-2-norbornene, 5-vinyl -Norbornene, dicyclooctadiene, methylene norbornene and the like can be mentioned.

  Specific examples of the ethylene-based copolymer rubber of component (a) include, for example, ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber, ethylene-1-butene copolymer rubber, ethylene Examples include -1-butene-nonconjugated diene copolymer rubber and ethylene-propylene-1-butene copolymer rubber. Among these, ethylene-propylene-nonconjugated diene copolymer rubber (EPDM) is preferable from the viewpoint of crosslinkability of the phenol resin crosslinking agent.

The range of the ethylene content of the component (a) used in the present invention is preferably 40 to 80% by weight, more preferably 50 to 75% by weight. In particular, in the range of 60 to 75% by weight, the balance between manufacturability, compression set at high temperature, and tensile strength is very good.
The non-conjugated diene content is preferably 0.5 to 8% by weight, more preferably 4 to 8% by weight. If it is less than the lower limit, the expression of compression set due to crosslinking is insufficient.

Further, the Mooney viscosity ML _{1 + 4} (125 ° C.) of the component (a) used in the present invention is preferably 10 to 180, more preferably 20 to 150. When the Mooney viscosity ML _{1 + 4} (125 ° C.) of the component (a) is less than 10, the compression set of the thermoplastic elastomer composition is lowered. When the upper limit is exceeded, moldability deteriorates.

  Further, the melting point of the crystal part in the DSC of the component (a) used in the present invention is less than 50 ° C, more preferably less than 45 ° C, and still more preferably less than 40 ° 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 temperature increase rate of 10 ° C / min.

(B) Crystalline olefin-based resin In the thermoplastic elastomer composition of the present invention, a crystalline olefin-based resin (b) can be contained. The component (b) is used for the purpose of improving oil resistance, adjusting the hardness, and improving moldability of the thermoplastic elastomer composition.
Examples of the component (b) used in the present invention include a crystalline ethylene or propylene homopolymer or a crystalline copolymer mainly composed of ethylene or propylene. For example, high-density polyethylene, low-density polyethylene, crystalline ethylene polymer such as ethylene / butene-1 copolymer, isotactic polypropylene, propylene / ethylene copolymer, propylene / butene-1 copolymer, propylene / Examples thereof include crystalline propylene-based polymers such as ethylene butene-1 terpolymer. Among these, a polypropylene resin is preferable.

Further, the melting point by DSC of the crystalline olefin resin (b) in the thermoplastic elastomer composition of the present invention is 50 ° C. or higher, preferably 130 ° C. or higher, more preferably 140 ° C. or higher, and still more preferably 150 It is above ℃.
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.

  When blended, the amount of component (b) is preferably 20 to 250 parts by weight, more preferably 30 to 150 parts by weight, based on 100 parts by weight of component (a). When the compounding amount of the component (b) exceeds the upper limit, the compression set decreases, and when it falls below the lower limit, the oil resistance, moldability, and bending fatigue resistance decrease.

(C) Crosslinking agent If the crosslinking agent (c) used in the thermoplastic elastomer composition of the present invention is a crosslinking agent capable of crosslinking the ethylene copolymer rubber (a), it is an organic peroxide, a sulfur type. Any non-crosslinking agent can be used as long as it is a crosslinking agent other than a crosslinking agent. Examples of non-sulfur crosslinking agents include phenol resins, maleimides, silicon-containing crosslinking agents, and the like. Among them, phenol resin crosslinking agents are used. preferable.

  Preferred phenolic resin crosslinkers, called resole resins, are prepared by condensation of alkyl-substituted phenols or unsubstituted phenols with aldehydes in an alkaline medium, preferably with formaldehyde, or with bifunctional phenol dialcohols. Is done. Alkyl substituents of alkyl substituted phenols typically have from 1 to about 10 carbon atoms. Preferred are dimethylolphenols or phenolic resins substituted with an alkyl group having from 1 to about 10 carbon atoms in the p-position. These phenolic crosslinking agents are typically thermosetting resins and are called phenolic resin crosslinking agents or phenolic resins. Specific examples of the crosslinking of the thermoplastic vulcanized resin with phenol resin are described in US Pat. No. 4,311,628, US Pat. Nos. 2,972,600 and 3,287,440. This technique can also be used in the present invention.

  Examples of preferred phenolic resin crosslinking agents are those represented by the general formula (I),

（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）

(In the formula, 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 an organic group. is there)

Defined by 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 above phenolic resins, alkylphenol formaldehyde resins, methylolated alkylphenol resins, brominated alkylphenol resins and the like are preferable, and those that are not brominated from the environmental viewpoint are desirable, but those having a terminal hydroxyl group brominated may be used, In particular, an alkylphenol formaldehyde resin is preferable.

  Examples of the above-mentioned phenolic cross-linking agents 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.), and tackolol. 250-III (brominated alkylphenol formaldehyde resin, manufactured by Taoka Chemical Co., Ltd.), PR-4507 (manufactured by Gunei Chemical Industry Co., Ltd.), Vulcaresat 510E (manufactured by Hoechst), Vulkaresat 532E (manufactured by Hoechst), Vulkaresen E (manufactured by Hoechst) Vulkaresen 105E (manufactured by Hoechst), Vulcaresen 130E (manufactured by Hoechst), Vulcaresol 315E (manufactured by Hoechst), mberol ST 137X (Rohm & Haas), Sumilite Resin PR-22193 (Sumitomo Durez), Symform-C-100 (Anchor Chem.), Symphor-C-1001 (Anchor Chem.), Tamorol 531 (Manufactured by Arakawa Chemical Co., Ltd.), Schenectady SP1059 (manufactured by Schenectady Chem.), Schenectady SP1045 (manufactured by Schemy Chem. Schenectady SP1056 (manufactured by Schenectady Chem.), CRM-0803 (manufactured by Showa Union Synthesis Co., Ltd.), Vulk Adur A (manufactured by Bayer) can be mentioned, and among them, tackolol 201 (alkylphenol formaldehyde resin) can be preferably used.

  The silicon-containing crosslinking agent generally includes a silicon hydride compound having at least one SiH group. These compounds react with the carbon-carbon double bond of the unsaturated polymer in the presence of a hydrosilylation catalyst. Hydrogenated siliceous compounds useful in practicing the present invention include methylhydrogen polysiloxanes, methylhydrogen dimethyl-siloxane copolymers, alkylmethyl polysiloxanes, and alkylmethyl polysiloxanes. polysiloxanes), bis (dimethylsilyl) alkanes, bis (dimethylsilyl) benzene, and mixtures thereof, but are not limited thereto.

  Preferred silicon hydride compounds have the formula:

（式中、各Ｒは、１乃至２０の炭素原子を有するアルキル、４乃至１２の炭素原子を有するシクロアルキル及びアリールから独立して選ばれ、ｍは１乃至約５０の値を有する整数であり、ｎは１乃至約５０の値を有する整数であり、ｐは、０乃至約６の値を有する整数である）により定義され得る。

Wherein each R is independently selected from alkyl having 1 to 20 carbon atoms, cycloalkyl having 4 to 12 carbon atoms, and aryl, and m is an integer having a value of 1 to about 50. , N is an integer having a value from 1 to about 50, and p is an integer having a value from 0 to about 6.

  The compounding quantity of a component (c) is 2-30 weight part with respect to 100 weight part of component (a), Preferably it is 5-25 weight part. When the amount of component (c) exceeds the upper limit, the fluidity of the thermoplastic elastomer composition is remarkably reduced, making it difficult to produce and mold. Moreover, compression set also deteriorates. On the other hand, if it is less than the lower limit, the compression set of the thermoplastic elastomer composition is deteriorated.

(D) Crosslinking accelerator The crosslinking accelerator (d) used in the thermoplastic elastomer composition of the present invention is used for more effectively improving the function of the crosslinking agent of component (c). As a component (c), when using a phenol resin crosslinking agent, zinc oxide, magnesium oxide, tin dichloride, etc. are mentioned. In addition, when using zinc oxide as a crosslinking catalyst, a stearic acid metal salt etc. can be used together as a dispersing agent. Of the above accelerators, zinc oxide is particularly preferred.

  The amount of component (d) is preferably 0.01 to 0.5 parts by weight, more preferably 0.05 to 0.3 parts by weight, per 100 parts by weight of component (a). If the blending amount of component (d) exceeds the above upper limit, crosslinking will not occur uniformly, and the fluidity of the resulting thermoplastic elastomer composition will be lowered, making it difficult to produce and mold, bending whitening resistance, bending fatigue resistance And oil bleed resistance deteriorate, and at the same time, compression set deteriorates. On the other hand, if it is less than the said lower limit, crosslinking efficiency will fall and the compression set of the thermoplastic elastomer composition obtained will deteriorate.

  Among the present invention, a combination of a non-halogen crosslinking agent as the component (c) and zinc oxide as the component (d) is preferable, and a combination of a non-halogen phenol crosslinking agent and zinc oxide is particularly preferable. In that case, even if there is no halogen donor, compression set in a good high temperature region can be exhibited by setting the addition amount of the component (c) and the component (d) in the above range.

  The ratio of (c) crosslinking agent to (d) crosslinking accelerator is preferably (d) / (c) = 0.03 / 100 to 50/100, more preferably 0.2 / 100 to 6 /. 100, more preferably 0.5 / 100 to 3/100.

  Among the present inventions, a combination of a non-halogen crosslinking agent and zinc oxide is preferable, and a combination of a non-halogen phenol crosslinking agent and zinc oxide is particularly preferable. In that case, even when there is no halogen donor, a good compression set in a high temperature region can be exhibited by using the amount of component (c) added to component (d) in the above ratio.

(E) Non-aromatic rubber softener The thermoplastic elastomer composition of the present invention may contain a non-aromatic rubber softener (e). The component (e) is used for the purpose of imparting flexibility and improving moldability of the thermoplastic elastomer composition.

  Examples of the non-aromatic rubber softener include paraffinic compounds having 4 to 155 carbon atoms, preferably paraffinic compounds having 4 to 50 carbon atoms, and specifically include butane, pentane, hexane, and heptane. , Octane, nonane, decane, undecane, dodecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosan, heneicosan, docosan, tricosan, tetracosan, pentacosan, hexacosan, heptacosan, octacosan, nonacosan, triacontane, hentria contane, N-paraffins (linear saturated hydrocarbons) such as dotriacontane, pentatriacontane, hexacontane, heptacontane, isobutane, isopentane, neopentane, isohexane, isopentane, neo Xane, 2,3-dimethylbutane, 2-methylhexane, 3-methylhexane, 3-ethylpentane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethyl Pentane, 2,2,3-trimethylbutane, 3-methylheptane, 2,2-dimethylhexane, 2,3-dimethylhexane, 2,4-dimethylhexane, 2,5-dimethylhexane, 3,4-dimethylhexane 2,2,3-trimethylpentane, isooctane, 2,3,4-trimethylpentane, 2,3,3-trimethylpentane, 2,3,4-trimethylpentane, isononane, 2-methylnonane, isodecane, isoundecane, Isododecane, isotridecane, isotetradecane, isopentadecane, isooctadecane, iso Nodekan, isoeicosane, 4-ethyl-5-isoparaffins methyl octane (branched saturated hydrocarbons) and can include derivatives of these saturated hydrocarbons. These non-aromatic rubber softeners are preferably used in a mixture and are liquid at room temperature.

  Commercially available non-aromatic rubber softeners that are liquid at room temperature include NA Solvent (isoparaffinic hydrocarbon oil) manufactured by Nippon Oil & Fats Co., Ltd., and PW-90 (n-paraffinic process manufactured by Idemitsu Kosan Co., Ltd.). Oil), IP-solvent 2835 (synthetic isoparaffinic hydrocarbon, 99.8 wt% or more isoparaffin) manufactured by Idemitsu Petrochemical Co., Ltd., neothiozole (n-paraffinic process oil) manufactured by Sanko Chemical Co., Ltd., and the like. .

  Moreover, a small amount of unsaturated hydrocarbons and derivatives thereof may coexist in the non-aromatic rubber softener. Unsaturated hydrocarbons include ethylene, propylene, 1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 3-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2 -Ethylene hydrocarbons such as butene, 1-hexene, 2,3-dimethyl-2-butene, 1-heptene, 1-octene, 1-nonene, 1-decene, acetylene, methylacetylene, 1-butyne, 2- Examples thereof include acetylene hydrocarbons such as butyne, 1-pentyne, 1-hexyne, 1-octyne, 1-nonine and 1-decyne.

  As for the compounding quantity of a component (e), 10-300 weight part is preferable with respect to 100 weight part of component (a), More preferably, it is 20-200 weight part. When the blending amount of the component (e) exceeds the upper limit, bleeding occurs on the surface of the molded article made of the composition obtained, and mechanical properties and compression set are also reduced. On the other hand, if the lower limit is not reached, the flexibility is lost and the moldability is also deteriorated.

(F) at least one heavy selected from the group consisting of a copolymer of an aromatic vinyl compound and a conjugated diene compound, a copolymer of a hydrogenated aromatic vinyl compound and a conjugated diene compound, and a hydrogenated conjugated diene compound polymer. Copolymer (f-1) Copolymer of aromatic vinyl compound and conjugated diene compound used for thermoplastic elastomer composition of the present invention, (f-2) Copolymer of hydrogenated aromatic vinyl compound and conjugated diene compound (F-3) At least one polymer (f) selected from the group consisting of hydrogenated conjugated diene compound polymers is used to hold (e) a non-aromatic rubber softener and adjust flexibility. Used for.

(F-1) A copolymer of an aromatic vinyl compound and a conjugated diene compound is (f-1-1) a random copolymer of an aromatic vinyl compound and a conjugated diene compound, or (f-1-2) aroma. And a block copolymer of an aromatic vinyl compound and a conjugated diene compound.

  (F-1-1) As an aromatic vinyl compound constituting a random copolymer of an aromatic vinyl compound and a conjugated diene compound, for example, styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, etc. One or more can be selected from among them, and styrene is particularly preferable. In addition, as the conjugated diene compound, for example, one or two or more kinds are selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc., among which butadiene, isoprene and These combinations are preferred.

(F-1-1) The random copolymer of the aromatic vinyl compound and the conjugated diene compound contains 3 to 60% by weight, preferably 5 to 50% by weight of the aromatic vinyl compound.

  (F-1-1) The number average molecular weight of the random copolymer of the aromatic vinyl compound and the conjugated diene compound is preferably 150,000 to 500,000, more preferably 170,000 to 400,000. Preferably it is the range of 200,000-350,000, and molecular weight distribution is 10 or less.

  Specific examples of the random copolymer of the (f-1-1) aromatic vinyl compound and the conjugated diene compound include a copolymer of styrene and butadiene (SBR).

  (F-1-2) In the case of a block copolymer of an aromatic vinyl compound and a conjugated diene compound, at least two polymer blocks A mainly composed of the aromatic vinyl compound and mainly composed of the conjugated diene compound. A block copolymer comprising at least one of polymer blocks B. For example, an aromatic vinyl compound-conjugated diene compound block copolymer having a structure such as ABA, BABA, ABBABA, or the like can be given.

  The block copolymer of the (f-1-2) aromatic vinyl compound and the conjugated diene compound contains 5 to 60% by weight, preferably 20 to 50% by weight of the aromatic vinyl compound.

  The polymer block A mainly composed of an aromatic vinyl compound is preferably composed only of an aromatic vinyl compound, or is a copolymer of an aromatic vinyl compound of 50% by weight or more, preferably 70% by weight or more and a conjugated diene compound. It is a coalesced block.

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

  (F-1-2) The number average molecular weight of the block copolymer of the aromatic vinyl compound and the conjugated diene compound is preferably 5,000 to 1,500,000, more preferably 10,000 to 550,000. More preferably, it is in the range of 100,000 to 400,000, and the molecular weight distribution is 10 or less. The molecular structure of the block copolymer may be linear, branched, radial, or any combination thereof.

  Further, in the polymer block A mainly composed of these aromatic vinyl compounds and the polymer block B mainly composed of conjugated diene compounds, the distribution of units derived from the conjugated diene compound or aromatic vinyl compound in the molecular chain is random, It may be tapered (in which the monomer component increases or decreases along the molecular chain), partially in a block form, or any combination thereof. When there are two or more polymer blocks A mainly composed of aromatic vinyl compounds or polymer blocks B mainly composed of conjugated diene compounds, each polymer block has a different structure even if each has the same structure. There may be.

  (F-1-2) Examples of the aromatic vinyl compound constituting the block copolymer of the aromatic vinyl compound and the conjugated diene compound include styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, and the like. One or more can be selected from among them, and styrene is particularly preferable. In addition, as the conjugated diene compound, for example, one or two or more kinds are selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc., among which butadiene, isoprene and These combinations are preferred.

  Specific examples of the block copolymer of (f-1-2) aromatic vinyl compound and conjugated diene compound include styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS). ) And the like.

  A number of methods have been proposed for producing block copolymers of these (f-1-2) aromatic vinyl compounds and conjugated diene compounds. Typical methods include, for example, JP-B-40- It can be obtained by block polymerization in an inert medium using a lithium catalyst or Ziegler type catalyst by the method described in Japanese Patent No. 23798.

  (F-2) A hydrogenated product of a copolymer of an aromatic vinyl compound and a conjugated diene compound is (f-2-1) a hydrogenated product of a random copolymer of an aromatic vinyl compound and a conjugated diene compound, (F-2-2) Hydrogenated product of block copolymer of aromatic vinyl compound and conjugated diene compound.

Component (f-2-1) Hydrogenated Random Copolymer of Aromatic Vinyl Compound and Conjugated Diene Compound As component (f-2-1) of the present invention, a conjugated diene compound and an aromatic vinyl compound are 50% by weight. A copolymer mainly having a random structure as described below, and examples of the aromatic vinyl compound include styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene. , N, N-diethyl-p-aminoethylstyrene, vinyltoluene, p-tert-butylstyrene, and the like can be selected, and among them, styrene is preferable.
Moreover, as a conjugated diene compound, 1 type (s) or 2 or more types is chosen from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, for example.

From the viewpoint of tensile properties and heat deformation resistance, the melt mass flow rate (according to ASTM D1238, measured at 230 ° C. and a load of 21.18 N) is preferably 12 g / 10 min or less, more preferably 6 g / 10 min or less. .
The aromatic vinyl compound content is preferably as low as 25% by mass or less for the purpose of obtaining a flexible resin composition. If it is 20 mass% or less, it is more preferable. For the same purpose, it is also important to saturate the carbon-carbon double bond of the conjugated diene compound by hydrogenation.

  In the random structure of an aromatic vinyl compound and a conjugated diene compound, the aromatic vinyl compound is randomly bonded, and at least 90% of the aliphatic double bond based on the conjugated diene compound is hydrogenated. preferable.

Examples of the component component (f-2-1) include Dynalon 1320P (JSR Corporation).

(F-2-2) Hydrogenated product of block copolymer of aromatic vinyl compound and conjugated diene compound (f-2-2) Hydrogenated product of block copolymer of aromatic vinyl compound and conjugated diene compound Is obtained by hydrogenating a block copolymer comprising at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound. Mention may be made of hydrogenated block copolymers or hydrogenated conjugated diene block copolymers.
A block comprising at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound that can be used in the thermoplastic elastomer composition of the present invention. The hydrogenated block copolymer component obtained by hydrogenating the copolymer contains at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound. It is a polymer obtained by hydrogenating one block copolymer. For example, a hydrogenated block copolymer of an aromatic vinyl compound-conjugated diene compound having a structure such as A-B, A-B-A, B-A-B-A, or A-B-A-B-A Is obtained.

  The polymer block A mainly composed of an aromatic vinyl compound may be a polymer composed only of an aromatic vinyl compound or a copolymer of an aromatic vinyl compound and less than 50% by weight of a conjugated diene compound. The polymer block B mainly composed of a conjugated diene compound may be a polymer composed solely of a conjugated diene compound or a copolymer of a conjugated diene compound and less than 50% by weight of an aromatic vinyl compound.

  (F-2-2) As the aromatic vinyl compound constituting the hydrogenated product of the block copolymer of the aromatic vinyl compound and the conjugated diene compound, for example, styrene, α-methylstyrene, vinyl toluene, p-second One or two or more types can be selected from 3-butyl styrene, among which styrene is preferable. In addition, as the conjugated diene compound, for example, one or two or more kinds are selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc., among which butadiene, isoprene and These combinations are preferred.

  Hydrogenated block obtained by hydrogenating a block copolymer comprising at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound In the polymer block B mainly composed of a conjugated diene compound, the hydrogenation rate of the polymer component is arbitrary, but it is preferably 50% or more, more preferably 55% or more, and still more preferably 60% or more. Further, the microstructure is arbitrary. For example, when the block B is composed of butadiene alone, the polybutadiene block preferably has a 1,2-microstructure of 20 to 50% by weight, particularly preferably 25 to 45%. % By weight. Moreover, the thing which hydrogenated the 1, 2- bond selectively may be sufficient. When block B is composed of a mixture of isoprene and butadiene, the 1,2-microstructure is preferably less than 50%, more preferably less than 25%, and even more preferably less than 15%.

  When block B is composed of isoprene alone, in the polyisoprene block, preferably 70 to 100% by weight of isoprene has a 1,4-microstructure, and preferably at least aliphatic double bonds derived from isoprene. 90% hydrogenated is preferred.

  (F-2-2) When using a hydrogenated product of a block copolymer of an aromatic vinyl compound and a conjugated diene compound depending on the application, it is preferable to use the above hydrogenated product appropriately according to the application. I can do it.

  Moreover, it is preferable that the polymer block A exists in the ratio of 5-70 weight% of the whole component. Furthermore, the weight average molecular weight of the whole component is preferably 150,000 to 500,000, more preferably 200,000 to 400,000. When the weight average molecular weight is below 200,000, oil bleeding occurs.

(F-2-2) Specific examples of hydrogenated components of block copolymers of aromatic vinyl compounds and conjugated diene compounds include styrene-ethylene / butene copolymers (SEB), styrene-ethylene / propylene copolymers. Polymer (SEP), styrene-ethylene-butene-styrene copolymer (SEBS), styrene-ethylene-propylene-styrene copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene copolymer (SEEPS), Examples thereof include a styrene-butadiene / butylene-styrene copolymer (partially hydrogenated styrene-butadiene-styrene copolymer, SBBS).
Among these, a styrene-ethylene / ethylene / propylene / styrene copolymer (SEEPS) is most preferable from the viewpoint of excellent flexibility imparting characteristics and a very small oil bleed. Of these, a styrene-ethylene / ethylene / propylene / styrene copolymer (SEEPS) having a weight average molecular weight of 200,000 to 400,000 is most preferable.

  A block obtained by hydrogenating a block copolymer comprising at least one polymer block A mainly composed of these aromatic vinyl compounds and at least one polymer block B mainly composed of a conjugated diene compound. As a method for producing a copolymer, a number of methods have been proposed. As a typical method, for example, a lithium catalyst or a Ziegler type catalyst is used by the method described in JP-B-40-23798. It can be obtained by block polymerization in an inert medium. Such a hydrogenation treatment of the block copolymer can be performed in the presence of a hydrogenation catalyst in an inert solvent by a known method.

Examples of the hydrogenated conjugated diene block copolymer that can be used in the thermoplastic elastomer composition of the present invention include, for example, a crystalline ethylene block obtained by hydrogenating a butadiene block copolymer and an amorphous block. And a block copolymer (CEBC) having a functional ethylene-butene block. In the present invention, the hydrogenated product of the conjugated diene compound block copolymer may be used alone or in combination of two or more.
Moreover, the weight average molecular weight of the hydrogenated product of the conjugated diene block copolymer is 500,000 or less, and preferably 200,000 to 450,000. When the weight average molecular weight exceeds 500,000, the extrusion / injection moldability deteriorates. When the weight average molecular weight falls below 200,000, oil bleeding occurs and compression set deteriorates.

  The compounding quantity of a component (f) is 5-100 weight part with respect to 100 weight part of component (a), Preferably it is 5-60 weight part. Oil bleed occurs when the amount of component (f) is less than 5 parts by weight. Moreover, when it exceeds 100 weight part, compression set will fall.

  (F) at least one selected from the group consisting of a copolymer of an aromatic vinyl compound and a conjugated diene compound, a copolymer of a hydrogenated aromatic vinyl compound and a conjugated diene compound, and a hydrogenated conjugated diene compound polymer. Among polymers, (f-2-2) Hydrogenation of a block copolymer of an aromatic vinyl compound and a conjugated diene compound is excellent in the effect of imparting flexibility, which is a feature of the present invention, and has very little oil bleed. Among them, styrene-ethylene / ethylene / propylene-styrene copolymer (SEEPS) is more preferable, and septon 4077 is most preferable in terms of molecular weight.

(H) Organic peroxide In the thermoplastic elastomer composition of the present invention, an organic peroxide (h) can be contained as required. Component (h) is used for the purpose of further improving the compression set of the thermoplastic elastomer composition.

  Examples of the component (h) include 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) -3,3,5- Trimethylcyclohexane, benzoyl peroxide, m-methylbenzoyl peroxide, m-toluoyl peroxide, t-hexylperoxybenzoate, 1,1-bis (t-butylperoxy) 2-methylcyclohexane, 1,1-bis (T-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (4,4-dibutylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) Oxy) cyclododecane, t-hexylperoxyisopropyl monocarbonate, oxalic acid peroxide 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, m-toluoyl and benzoyl Peroxide, t-butylperoxyisobutyrate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate , T-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxyacetate, 2,2-bis (t-butylperoxy) butane , Dicumyl peroxide, di-tert-butyl peroxide, 2,5 Dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-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-chloro Examples thereof include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butyl cumyl peroxide and the like.

  Of these, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane (1 minute half-life temperature 147 ° C.), 2, in terms of odor, colorability and scorch stability 5-dimethyl-2,5-di (tert-butylperoxy) hexane (1 minute half-life temperature 179 ° C.) and 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3 (1 minute) A half-life temperature of 194 ° C.) is preferable. In the case of the composition of the present invention, a low-temperature decomposition type organic peroxide having a 1 minute half-life temperature of 165 ° C. or less may be used.

  When blended, the amount of component (h) is 0.01 to 0.5 parts by weight, preferably 0.01 to 0.3 parts by weight, based on 100 parts by weight of component (a). . If the blending amount exceeds 0.5 parts by weight, the decomposition reaction by the organic peroxide is prioritized and the compression set is lowered.

(I) Other components In the thermoplastic elastomer composition of the present invention, a heat stabilizer, an antioxidant, a light stabilizer, an ultraviolet absorber, a crystal nucleating agent, and a blocking agent are further added as long as the object of the present invention is not impaired. Inhibitors, sealability improvers, release agents such as stearic acid and silicone oil, lubricants such as polyethylene wax, colorants, pigments, inorganic fillers (alumina, talc, calcium carbonate, mica, wollastonite, clay), A foaming agent (organic or inorganic), a flame retardant (hydrated metal compound, red phosphorus, ammonium polyphosphate, antimony, silicone) or 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.

2. Production of Thermoplastic Elastomer Composition The thermoplastic elastomer composition of the present invention may be prepared by adding the above components (a) to (f) or other components as necessary, and adding each component simultaneously or in any order. It can be manufactured by mixing.

  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. For example, the above operation can be performed continuously by using an appropriate L / D twin screw extruder, Banbury mixer, pressure kneader, or the like. Here, the temperature of the melt kneading is preferably 160 to 200 ° C., and it is preferable to take a kneading time of 5 to 30 minutes in order to sufficiently advance the crosslinking. More preferably, it is 10 to 20 minutes.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example and a comparative example, this invention is not limited only to an Example. The evaluation methods and raw materials used in the examples are as follows.

1. Evaluation method (1) Specific gravity: In accordance with JIS K 7112, 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 a durometer hardness, type A, using a 6.3 mm thick press sheet.
(3) Tensile strength, 100% modulus, 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 the test piece. The measurement was performed at 70 ° C. × 22 hours under the condition of 25% deformation.
(5) Manufacturability: Manufactured with a pressure kneader mixer having a capacity of 3 L (kneading at 180 ° C. for 10 to 30 minutes) and evaluated according to the following criteria.
○: The thermoplastic kneaded material was discharged.
X: The discharged material is not thermoplastic.
(6) Extrudability: A 17 mm diameter round bar was extruded at 130 to 140 ° C. with a 40 mm extruder, the drawdown property, surface appearance and shape were observed, and evaluated according to the following criteria.
○: Good Δ: Surface appearance and shape are good, but there is a slight drawdown ×: Poor (7) Injection moldability: A 130 mm × 130 mm × 2 mm sheet is injection molded at 130-150 ° C. with a 120 t injection molding machine, The appearance was visually observed and the presence or absence of flow marks and sink marks was evaluated according to the following criteria.
○: Good △: Sink also looks good but has a slight flow mark ×: Bad (8) Bending whitening property: When a 2 mm thick press sheet is fixed with a 180-degree folding clip, left for 1 hour, and the clip is removed The state of was evaluated according to the following criteria.
○: No cracks, whitening or wrinkles in the folds ×: Cracks, whitening or wrinkles in the creases (9) Bending fatigue resistance: In accordance with JIS K 6260, the test piece is a 2 mm thick press sheet, 25 mm wide and long It was used by punching to a thickness of 150 mm. The maximum distance between grips in the reciprocating motion was 75 mm, and the minimum distance was 18 mm. After performing this reciprocating motion 1000000 times at a speed of 300 times per minute, the state when the test piece was removed was visually confirmed and evaluated according to the following criteria.
○: No cracking ×: Cracking (10) Oil bleed resistance: Kraft sheet of 130 × 160 × 2 mm thickness obtained by hot press at 180 ° C., preheating 2 minutes / pressurization 2 minutes, pressure 50 kg / cm ² A 500 g weight having a disk shape of 70 mm in diameter was put between papers, and the state of the kraft paper after standing for 168 hours at room temperature (23 ° C.) was visually observed and evaluated according to the following criteria.
◎: No trace of oil bleed is observed on kraft paper ○: Trace of oil bleed is observed slightly on kraft paper △: Trace of oil bleed is observed in 10% or more and less than 30% of kraft paper ×: Traces of oil bleed are observed in 30% or more of the kraft paper area (12) Oil absorbency: until kneading with a 3 L pressure kneader until the non-aromatic rubber softener is completely absorbed and the liquid content disappears The time was judged visually and evaluated according to the following criteria.
○: Absorbed within 5 minutes ×: Not absorbed even after kneading for 5 minutes or more (13) Oil resistance evaluation Volume swelling rate (%): In accordance with JIS K 6258, 2 mm thick press sheet was used for the test piece . The swelling ratio after immersion in IRM # 902 at 120 ° C. for 24 hours was measured.

2. Raw material component (a): Nordel IP 4760P Specific gravity: 0.86 Mooney viscosity ML _{1 + 4} (125 ° C.): 70 (ASTM D-1646) Weight average molecular weight: 210,000 Ethylene: 67% ENB: 4.9% Melting point 5 ° C
(B) Crystalline olefin resin: Novatec BC08AHA (manufactured by Nippon Polychem Co., Ltd.) Polypropylene, 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, melting point 160 ° C.
Ingredient (c): Phenolic resin: Tackirol 201 (Taoka Chemical Co., Ltd.)
Ingredient (d): Zinc oxide: Two types of zinc white (manufactured by Sakai Chemical Co., Ltd.)
Component (e) Non-aromatic rubber softener: Paraffin oil: PW-90 (manufactured by Idemitsu Kosan Co., Ltd.) Average molecular weight 746
Component (f-1-1) SBR: JSR SL552 Styrene 24%, Mooney viscosity ML _{1 + 4} (100 ° C.) 55, vinyl bond amount 39%, specific gravity 0.94
Ingredient (f-1-2) SBS: VECTOR 2518, DEXCO POLYMERS
Component (f-2-2) Hydrogenated product of block copolymer of aromatic vinyl compound and conjugated diene compound: Septon 4077 (trademark; manufactured by Kuraray Co., Ltd.), styrene content 30% by weight, number average molecular weight 260, 000, weight average molecular weight 320,000, molecular weight distribution 1.23, hydrogenation rate 90% or more Component (f-2-2) Hydrogenated block copolymer of aromatic vinyl compound and conjugated diene compound: Septon 4033 (SEPS) (trademark; manufactured by Kuraray Co., Ltd.), styrene content 30% by weight, number average molecular weight 130,000, weight average molecular weight 100,000, molecular weight distribution 1.30, hydrogenation rate 90% or more Component (f) CEBC : JSR DYNARON HSB1729
Specific gravity 0.88, hardness 73A, glass transition point-50 ° C (ASTM D3418), MFR 0.5g / 10 min (230 ° C, 98N, ASTM D1238)

Examples 1-8, Comparative Examples 1-12
Each component was put into a pressure kneader type mixer having a capacity of 3 L and melt-kneaded at a kneading temperature of 180 ° C. and a kneading time of 10 to 30 minutes to form pellets. Next, the obtained pellet was injection-molded and press-molded to prepare a test piece, which was used for each test. The evaluation results are shown in Table 1.

As is clear from Table 1, the thermoplastic elastomer composition of the present invention had good characteristics (Examples 1 to 8).
On the other hand, in Comparative Examples 1 and 2, the amount of component (b) is out of the scope of the present invention.
When the component (b) is less than the lower limit, oil resistance, moldability, and bending fatigue resistance are lowered. On the other hand, when the upper limit is exceeded, compression set is reduced.
In Comparative Examples 3 and 4, the amount of component (c) is out of the scope of the present invention. If it is less than the lower limit, the compression set and oil resistance of the thermoplastic elastomer composition deteriorate. When the upper limit is exceeded, the fluidity of the thermoplastic elastomer composition is remarkably reduced, making production and molding difficult. Moreover, compression set also deteriorates.
In Comparative Examples 5 and 6, the amount of component (d) is out of the scope of the present invention. If it is less than a lower limit, crosslinking efficiency will fall and the compression set and oil resistance of the thermoplastic elastomer composition obtained will deteriorate. If the upper limit is exceeded, crosslinking will not occur uniformly, and the fluidity of the resulting thermoplastic elastomer composition will be reduced, making it difficult to produce and mold, resulting in deterioration in bending whitening resistance, bending fatigue resistance, and oil bleed resistance. At the same time, compression set deteriorates.
In Comparative Examples 7 and 8, the amount of component (e) is out of the scope of the present invention. Below the lower limit, flexibility is lost and moldability deteriorates. If the upper limit is exceeded, bleeding occurs on the surface of the molded article made of the composition obtained, and mechanical properties, compression set, and oil resistance also deteriorate.
In Comparative Examples 9 and 10, the amount of component (f) is out of the scope of the present invention. If it is less than the lower limit, oil bleeding occurs. On the other hand, when the upper limit is exceeded, compression set and oil resistance deteriorate.
In Comparative Example 11, acrylonitrile-butadiene copolymer (NBR) was used instead of component (f).
The obtained composition was inferior in mechanical strength, bending whitening and bending fatigue, and inferior in oil absorption and oil bleeding resistance.
In Comparative Example 11, isoprengo soot (IR) was used instead of component (f).
The resulting composition was inferior in oil absorption, oil bleed resistance, bending whitening, and bending fatigue resistance.

  The thermoplastic elastomer composition of the present invention is excellent in compression set in a high temperature region, and is excellent in extrusion moldability and injection moldability. Therefore, the blow molding method, extrusion molding method, injection molding method, thermoforming method, elastic welding (elasto -Welding) method, compression molding method, and the like.

Specific applications include, for example, automotive parts, lighting gaskets, 3D exchange blow clean air ducts, Furo seal hinge covers, belly pans (Robotec extrusion gaskets), cup holders, side brake grips, shift knob covers, seat adjustment knobs, IP Skin, flapper door seal, wire harness grommet, rack and pinion boot, suspension cover boot (strut cover boot), glass guide, inner belt line seal, roof guide, trunk lid seal, molded quarter window gasket, corner molding, glass encap Schlation (Robotech Extrusion), food seal, glass encap shresh Down (injection molding), glass run channels, secondary seals, and the like. Industrial parts include curtain wall gaskets for high-rise buildings, window frame seals, adhesion to metals / reinforcing fibers, parking deck seals, expansion joints, expansion joints for earthquake countermeasures, and residential window door seals (for example, coextrusion). , Housing door seal, handrail skin, walking mat (sheet), rubber feet, washing machine drain hose (two-color molding with PP, etc.), washing machine lid seal, air conditioner motor mount, drain pipe seal (two colors with PP) Molding, etc.), riser tube, (PVC etc.) pipe joint packing, caster wheel, printer roll, duct hose, wire & cable, syringe shrimp gasket and the like. Furthermore, as daily necessities / parts, speaker surround, hairbrush grip, razor grip, cosmetic grip / foot, toothbrush grip, daily necessities brush grip, broom tip, kitchenware grip, measuring spoon grip, branch cutting scissor grip, glass heat-resistant container lid Garden grips, scissor grips, stapler grips, computer mice, golf bag parts, wall-coated iron grips, chainsaw grips, screwdriver grips, hammer grips, electric drill grips, grinder grips, alarm clocks, etc.

  More specific specific applications include, for example, vehicle parts such as weather seals, brake parts such as cups, coupling discs and diaphragm cups, boots such as constant speed joints and rack transmission joints, tubes, sealing gaskets, Parts of hydraulic or pneumatic actuators, O-rings, pistons, valves, valve seats, valve guides and other elastic polymer-based parts, or elastic polymers in combination with other materials such as metal / plastic combination materials, V-belts A transmission belt comprising a molded rubber having a toothed belt, ground short fiber reinforced V or short fiber flocked V, with truncated ribs having a cloth surface finish V Etc.

Claims (7)

(A) 100 parts by weight of ethylene copolymer rubber,
(B) 20 to 250 parts by weight of a crystalline olefin resin,
(C) 2 to 30 parts by weight of a phenol resin-based crosslinking agent (d) 0.01 to 0.5 parts by weight of at least one crosslinking accelerator selected from the group consisting of zinc oxide, magnesium oxide and tin dichloride (e) 10 to 300 parts by weight of softener for aromatic rubber (f) Copolymer of aromatic vinyl compound and conjugated diene compound, copolymer of hydrogenated aromatic vinyl compound and conjugated diene compound, hydrogenated conjugated diene compound 5 to 100 parts by weight of at least one polymer selected from the group consisting of polymers,
A thermoplastic elastomer composition comprising: 2. The thermoplastic elastomer composition according to claim 1, wherein the ethylene copolymer rubber has a Mooney viscosity of 10 to 180 (ML _{1 + 4} , 125 ° C.). The thermoplastic elastomer composition according to claim 1 or 2, wherein (c) the phenol resin-based crosslinking agent is at least one crosslinking agent selected from the group consisting of phenol resins and brominated phenol resins. (C) The thermoplastic resin composition according to any one of claims 1 to 3, wherein the phenolic resin-based crosslinking agent is an alkylphenol formaldehyde resin. The thermoplastic elastomer composition according to any one of claims 1 to 4 , wherein (d) the crosslinking accelerator is zinc oxide. The thermoplastic peroxide according to any one of claims 1 to 5 , wherein (h) the organic peroxide is contained in an amount of 0.01 to 0.5 parts by weight with respect to 100 parts by weight of the component (a). Elastomer composition. The molded object characterized by shape | molding from the thermoplastic-elastomer composition of any one of Claims 1-6 .