JP2006143783A - Thermoplastic crosslinked rubber composition - Google Patents

Abstract

A thermoplastic crosslinked rubber composition having excellent continuous productivity and mechanical strength is provided.
A crosslinked thermoplastic crosslinked rubber composition comprising (A) a crosslinkable rubber-like polymer, (B) an olefinic resin, and (C) an olefinic wax, wherein (C) is It is produced using a metallocene catalyst containing ethylene and an α-olefin having 3 to 20 carbon atoms, and the weight average molecular weight (Mw) calculated by gel permeation chromatography (GPC) is 3000 to 20000. An average molecular weight (Mn) of 500 to 10,000 is a highly productive thermoplastic crosslinked rubber composition.
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Description

  The present invention relates to a thermoplastic crosslinked rubber composition. More specifically, the present invention relates to a thermoplastic crosslinked rubber composition that has excellent mechanical strength and enables stabilization of quality for excellent continuous productivity.

A thermoplastic elastomer composition by so-called dynamic crosslinking, in which a radically crosslinkable elastomer and a non-radical crosslinkable resin such as PP are cross-linked while melt-kneaded in an extruder in the presence of a radical initiator, is a known technique. It is widely used for applications such as automobile parts.
As such a thermoplastic elastomer composition, a dynamic crosslinking technique using an olefin-based elastomer (for example, see Patent Documents 1 and 2) produced by ethylene-propylene-diene rubber (EPDM) is known. Since the productivity and mechanical strength are not sufficient and not necessarily satisfied in the market, there is a need in the industry for thermoplastic elastomer compositions that can withstand practical use.
JP-A-8-120127 Japanese Patent Laid-Open No. 9-137001

  In view of such a current situation, an object of the present invention is to provide a thermoplastic crosslinked rubber composition that does not have the above-described problems, that is, has excellent continuous productivity and mechanical strength.

As a result of intensive studies on a thermoplastic crosslinked rubber composition having excellent continuous productivity and mechanical strength, the present inventors have surprisingly achieved continuous productivity and mechanical strength by combining specific polymers. The present invention has been completed.
That is, the present invention relates to a crosslinked thermoplastic crosslinked rubber composition comprising (A) a crosslinkable rubber-like polymer, (B) an olefinic resin, and (C) an olefinic wax, wherein the (C) Which contains ethylene and an α-olefin having 3 to 20 carbon atoms, is produced using a metallocene catalyst, and has a weight average molecular weight (Mw) calculated by gel permeation chromatography (GPC) of 3000 to 20000, A thermoplastic crosslinked rubber composition having a number average molecular weight (Mn) of 500 to 10,000,
It is.

  The thermoplastic crosslinked rubber composition of the present invention has excellent mechanical strength, and enables stabilization of quality due to excellent continuous productivity.

The present invention will be specifically described below.
The composition of the present invention comprises (A) a crosslinkable rubbery polymer, (B) an olefin resin, and (C) an olefin wax.
Here, it is important that the components (A) and (B) are crosslinked while maintaining thermoplasticity. Crosslinking of the above components improves excellent mechanical properties, particularly rubber properties and durability.
And since component (C) acts as a dispersing agent and a processing aid with respect to components (A) and (B), it has been found that continuous productivity and mechanical strength are remarkably improved, and the present invention is completed. did.

Hereinafter, each component of the present invention will be described in detail.
Ingredient (A)
In the present invention, (A) the crosslinkable rubber-like polymer is, for example, a diene rubber such as polybutadiene, poly (styrene-butadiene), poly (acrylonitrile-butadiene), and a saturated polymer rubber obtained by hydrogenating the diene rubber. (Hydrogenated copolymer rubber), isoprene rubber, chloroprene rubber, acrylic rubber such as polybutyl acrylate, ethylene-propylene copolymer, ethylene-octene copolymer, ethylene-propylene-diene monomer terpolymer Examples thereof include a crosslinked rubber or non-crosslinked rubber such as an ethylene / α-olefin copolymer such as (EPDM), and a thermoplastic elastomer containing the rubber component.
Further, (A) preferably has a glass transition temperature (Tg) of −10 ° C. or lower.
The Mooney viscosity (ML) (based on ISO 289-1985 (E)) measured at 100 ° C. of the component (A) is preferably 20 to 150, more preferably 50 to 120.

  In the present invention, one of the preferred polymers for the component (A) is an ethylene / α-olefin copolymer, more preferably a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. Examples of the α-olefin include propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, and dodecene-1. Etc. Among them, hexene-1, 4-methylpentene-1, and octene-1 are preferable, and an α-olefin having 3 to 12 carbon atoms is particularly preferable, and propylene, butene-1, and octene-1 are most preferable.

In addition, the component (A) can contain a monomer having an unsaturated bond as necessary, for example, conjugated diolefins such as butadiene and isoprene, non-conjugated diolefins such as 1,4-hexadiene, Examples thereof include cyclic diene compounds such as dicyclopentadiene and norbornene derivatives, and acetylenes. In particular, ethylidene norbornene (ENB) and dicyclopentadiene (DCP) are most preferable.
In the present invention, an ethylene / α-olefin copolymer (hereinafter referred to as an ethylene / α-olefin copolymer of (A)), which is one of the preferred copolymers of component (A), is a known metallocene catalyst. It is preferable to manufacture using.

In general, a metallocene catalyst comprises a cyclopentadienyl derivative of a group IV metal such as titanium or zirconium and a co-catalyst, and is not only highly active as a polymerization catalyst but also a polymer obtained in comparison with a Ziegler catalyst. The molecular weight distribution is narrow and the distribution of the α-olefin having 3 to 20 carbon atoms, which is a comonomer in the copolymer, is uniform.
The ethylene / α-olefin copolymer of component (A) used in the present invention preferably has a copolymerization ratio of α-olefin of 1 to 60% by weight, more preferably 10 to 50% by weight, most preferably. Is 20 to 45% by weight. The copolymerization ratio of α-olefin is preferably 60% by weight or less from the viewpoints of the hardness and tensile strength of the composition, and is preferably 1% by weight or more from the viewpoints of flexibility and mechanical strength.

The density of the ethylene / α-olefin copolymer of component (A) is preferably in the range of 0.8 to 0.9 g / cm ³ . By using an ethylene / α-olefin copolymer having a density in this range, the thermoplastic elastomer composition of the present invention having excellent flexibility and low hardness can be obtained.
The ethylene / α-olefin copolymer of component (A) used in the present invention desirably has long chain branching. Due to the presence of long chain branching, it is possible to make the density smaller compared to the proportion (% by weight) of the α-olefin copolymerized without reducing the mechanical strength. An ethylene / α-olefin copolymer having high hardness and high strength can be obtained. The ethylene / α-olefin copolymer having a long chain branch is described in US Pat. No. 5,278,272.

The ethylene / α-olefin copolymer of component (A) preferably has a melting point peak of a thermobalance (DSC) above room temperature. When it has a melting point peak, the form is stable in the temperature range below the melting point, it is easy to handle and has little stickiness.
The melt index of the ethylene / α-olefin copolymer of the component (A) used in the present invention is in the range of 0.01 to 100 g / 10 minutes (190 ° C., 2.16 kg load (0.212 Pa)). Are preferably used, more preferably 0.2 to 10 g / 10 min. From the viewpoint of crosslinkability of the thermoplastic crosslinked rubber composition of the present invention, 100 g / 10 min or less is preferable, and from the viewpoint of fluidity and processability, 0.01 g / 10 min or more is preferable.

In the present invention, the hydrogenated copolymer which is another preferred copolymer of the component (A) is a homopolymer rubber of at least one conjugated diene monomer, or a conjugated diene monomer and an aromatic A copolymer rubber composed of an aromatic vinyl monomer, preferably a hydrogenated copolymer rubber in which the hydrogenation rate of the full double bond of the random copolymer is 50% or more, particularly the main chain and the side chain A hydrogenated copolymer rubber in which 50% or more of all olefinic double bonds of the unsaturated polymer rubber comprising a polymer and / or copolymer having a double bond are hydrogenated is preferable.
In the hydrogenated copolymer rubber, if necessary, for example, olefinic, methacrylic ester, acrylic ester, unsaturated nitrile, vinyl chloride monomer and other conjugated dienes can be copolymerized. A monomer (hereinafter referred to as a copolymerizable monomer) can be copolymerized.

Examples of the conjugated diene monomer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3- Hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene and the like can be mentioned, and 1,3-butadiene, isoprene and 1,3-pentadiene are preferable, Most preferred are 3-butadiene and isoprene.
Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, t-butylstyrene, divinylbenzene, N, N-dimethyl-p-aminoethylstyrene, and vinylpyridine. Styrene and α-methylstyrene are preferable. The aromatic monomers can be used alone or in combination of two or more. The aromatic vinyl monomer content is preferably 0 to 80% by weight, more preferably 0 to 50% by weight, and most preferably 0 to 30% by weight.

  In the hydrogenated copolymer as the component (A), the vinyl bond in the conjugated diene monomer portion before hydrogenation may be present uniformly in the molecule, or may increase or decrease or decrease along the molecular chain. It may also include a plurality of blocks having different vinyl bond contents. When the aromatic vinyl monomer and / or copolymerizable monomer is included, the conjugated diene monomer and the aromatic vinyl monomer and / or copolymerizable monomer are randomly bonded. However, it may contain a block-like aromatic vinyl monomer and / or a block-like copolymerizable monomer. The content of the block-like aromatic vinyl polymer is preferably 20% by weight or less, more preferably 10% by weight or less, based on the total aromatic vinyl monomer.

The total olefinic double bonds in the hydrogenated copolymer rubber are 50% or more, preferably 90% or more, more preferably 95% or more, and the remaining double bonds in the main chain are 5% or less. The residual double bond in the side chain is 5% or less. Specific examples of such hydrogenated copolymer rubbers include partially or completely hydrogenated diene rubbers such as polybutadiene, poly (styrene-butadiene), poly (acrylonitrile-butadiene), polyisoprene, polychloroprene. Examples thereof include rubber-like polymers, and hydrogenated butadiene-based or hydrogenated isoprene-based rubber is particularly preferable.
Such a hydrogenated copolymer rubber can be obtained by partially hydrogenating the above-described diene rubber by a known hydrogenation method. For example, a method of hydrogenation using a triisobutylborane catalyst described in FLRamp, etal, J. Amer. Chem. Soc., 83, 4672 (1961), HungYu Chen, J. Polym. Sci. Polym. Letter Ed., A method of hydrogenation using toluenesulfonylhydrazide described in 15,271 (1977), or a method of hydrogenation using an organic cobalt-organic aluminum catalyst or an organic nickel-organic aluminum catalyst described in Japanese Patent Publication No. 42-8704. Can be mentioned.

Here, particularly preferred hydrogenation methods are disclosed in JP-A-59-133203 and JP-A-60-220147 using inert catalysts that can be hydrogenated under mild conditions of low temperature and low pressure, or inert organic compounds. Contacting with hydrogen in a solvent in the presence of a catalyst comprising a bis (cyclopentadienyl) titanium compound and a hydrocarbon compound having a sodium atom, a potassium atom, a rubidium atom or a cesium atom This is the method shown in the gazette.
The hydrogenated copolymer rubber preferably has a 5 wt% styrene solution viscosity (5% SV) at 25 ° C. in the range of 20 to 300 centipoise (cps). A particularly preferred range is 25 to 150 cps.
The hydrogenated copolymer rubber preferably has crystallinity, and the endothermic peak calorific value, which is an index of crystallinity, is controlled by adding a polar compound such as tetrahydrofuran or controlling the polymerization temperature. The reduction of the endothermic peak heat amount is achieved by increasing the amount of polar compound during the production of the rubbery polymer or increasing the 1,2-vinyl bond by decreasing the polymerization temperature.

The component (A) used in the present invention may be a mixture of a plurality of types. In such a case, the workability can be further improved.
In the present invention, the proportion of the polymer having a polystyrene equivalent molecular weight of 150,000 or less in the component (A) is preferably 30% by weight or less, more preferably 25% or less, still more preferably 20% or less, most preferably Preferably it is 15% or less, Most preferably, it is 10% or less. When the ratio is 30% or less, the crosslinkability is remarkably increased, and the mechanical strength, appearance, feel, wear resistance and oil resistance are improved.
In the present invention, as a method for controlling the proportion of the polymer having a polystyrene-reduced molecular weight of 150,000 or less in the component (A), a method for increasing the overall molecular weight so that the portion having a molecular weight of 150,000 or less is 30% or less. Or a method of removing a part having a molecular weight of 150,000 or less by an operation such as extraction, or a polymerization method in which a molecular weight of 150,000 or less is not selectively generated by a polymerization catalyst or the like.

Ingredient (B)
The component (B) in the present invention is a copolymer resin containing ethylene or / and α-olefin, which is 2 to 20 carbon atoms, such as ethylene or propylene resin, and particularly propylene resin. Is preferred. Moreover, about the molecular weight of a component (B), it exists in the high molecular weight area | region from the below-mentioned component (C) olefin wax.
Specific examples of the propylene-based resin most preferably used in the present invention include homoisotactic polypropylene, propylene, and other α-olefins such as ethylene, butene-1, pentene-1, and hexene-1. And isotactic copolymer resins (including blocks and random).
In the present invention, among components (B), (B-1) a propylene random copolymer resin such as a random copolymer resin of ethylene and propylene, which is a cross-linked olefin resin, or (B-1) and (B-2) A combination with a propylene block copolymer resin or a homopolypropylene resin, which is a decomposable olefin resin, is preferred. The appearance and mechanical strength are further improved by combining two types of olefin resins, such as a crosslinked olefin resin and a decomposable olefin resin.

Examples of the component (B-1) include a random copolymer resin of ethylene and propylene. When the ethylene component is present in the polymer main chain, it becomes a cross-linking point of the cross-linking reaction, and a cross-linked olefin resin. The characteristics of
Component (B-2) is mainly composed of an α-olefin, and preferably contains no ethylene unit in the polymer main chain. However, when an ethylene-α olefin copolymer is present as a dispersed phase, such as a propylene block copolymer resin, the characteristics of the decomposable olefin resin are exhibited.
Component (B) may be a combination of a plurality of components (B-1) and (B-2).
Among the most preferable components (B-1), a random copolymer resin with an α-olefin mainly composed of propylene can be produced by a high pressure method, a slurry method, a gas phase method, a bulk method, a solution method, and the like. As the polymerization catalyst, Ziegler-Natta catalyst, single site, metallocene catalyst is preferable. In particular, when a narrow composition distribution and molecular weight distribution are required, a random copolymerization method using a metallocene catalyst is preferable.

A specific method for producing a random copolymer resin is disclosed in European Patent No. 0969433A1 or US Pat. No. 5,1984,401, and after introducing liquid propylene into a reactor equipped with a stirrer, the catalyst is introduced into a gas phase or liquid phase from a nozzle. Add to. Next, ethylene gas or α-olefin is introduced into the gas phase or liquid phase of the reactor, and the reaction temperature and reaction pressure are controlled to conditions under which propylene is refluxed. The polymerization rate is controlled by the catalyst concentration and the reaction temperature, and the copolymer composition is controlled by the amount of ethylene or α-olefin added.
Moreover, the thing of the range of 0.1-100 g / 10min (230 degreeC, 2.16kg load (0.212Pa)) is preferably used for the melt index of the olefin resin used suitably by this invention. From the viewpoint of heat resistance and mechanical strength of the thermoplastic elastomer composition, it is preferably 100 g / 10 min or less, and from the viewpoint of fluidity and moldability, 0.1 g / 10 min or more is preferable.

Ingredient (C)
In the present invention, the component (C) is produced using a metallocene catalyst containing ethylene and an α-olefin having 3 to 20 carbon atoms, and is calculated by gel permeation chromatography (GPC) (Mw) ) Is 3000-20000, preferably 3000-15000, more preferably 5000-10000, and the number average molecular weight (Mn) is 500-10000, preferably 500-8000, more preferably 1000. ~ 5000.

Conventional olefinic waxes are often sticky because they contain low molecular weight components in the oligomer region and often give off bad odors, but consist of a cyclopentadienyl derivative of a group IV metal such as titanium or zirconium and a promoter. Olefinic waxes produced with metallocene catalysts have not only a narrow molecular weight distribution, but in the case of copolymers, the distribution of the α-olefin having 3 to 20 carbon atoms, which is a comonomer, is uniform. Less is.
In the present invention, the component (A) is preferably 1 to 99% by weight, more preferably 10 to 80% by weight, in each component in 100 parts by weight of the composition comprising the components (A), (B) and (C). , Most preferably 20 to 70% by weight, component (B) is preferably 0.99 to 99% by weight, more preferably 19.99 to 85% by weight, most preferably 29.9 to 77% by weight. Component (C) is preferably 0.01 to 10% by weight, more preferably 0.01 to 5% by weight, and most preferably 0.1 to 3% by weight. Within the above range, the balance between formability and mechanical strength is improved.

Ingredient (D)
The composition of the present invention is preferably crosslinked with a crosslinking agent (D).
Component (D) contains (D-1) a crosslinking initiator as an essential component, and contains (D-2) a polyfunctional monomer and (D-3) a monofunctional monomer as necessary. The component (D) is used in an amount of 0.001 to 10 parts by weight, preferably 0.005 to 3 parts by weight based on 100 parts by weight of the total of components (A), (B) and (C). Within the above range, the level of crosslinking increases, and the balance between the appearance and mechanical strength of the composition is improved.

Here, examples of the (D-1) crosslinking initiator include radical initiators such as organic peroxides and organic azo compounds, and specific examples thereof include 1,1-bis (t-butylperoxy). −3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1- Bis (t-butylperoxy) cyclododecane, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl-4,4-bis (t Peroxyketals such as -butylperoxy) butane and n-butyl-4,4-bis (t-butylperoxy) valerate.
Further, di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, α, α′-bis (t-butylperoxy-m-isopropyl) benzene, α, α′-bis (t- Butylperoxy) diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 Dialkyl peroxides: acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl Such as peroxide and m-trioyl peroxide Examples include diacyl peroxides.

  Furthermore, t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, di-t -Peroxyl such as butyl peroxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, and cumylperoxyoctate Oxyesters; and t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide and 1,1,3,3-tetramethyl Butyl peroxide It may be mentioned of hydroperoxides.

Among these compounds, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2, 5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 are preferred.
The component (D-1) is preferably used in an amount of 1 to 80% by weight, more preferably 10 to 50% by weight in the component (D). 1% by weight or more is preferable from the viewpoint of crosslinkability, and 80% by weight or less is preferable from the viewpoint of mechanical strength.

  In the present invention, the (D) polyfunctional monomer contained in the (D) crosslinking agent as necessary is preferably a radical polymerizable functional group as a functional group, and particularly preferably a vinyl group. Although the number of functional groups is 2 or more, it is effective particularly in the case of having 3 or more functional groups in combination with (D-3). Specific examples include divinylbenzene, triallyl isocyanurate, triallyl cyanurate, diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, ethylene glycol dimethacrylate, Triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, P-quinonedioxime, P, P'-dibenzoylkidioxime, phenylmaleimide, allyl methacrylate, N, N'-m-phenylenebismaleimide, diallyl phthalate , Tetraallyloxyethane, 1,2-polybutadiene and the like are preferably used. Triaryl isocyanurate is particularly preferable. These polyfunctional monomers may be used in combination.

The (D-2) is preferably used in an amount of 1 to 80% by weight, more preferably 10 to 50% by weight in the component (D). 1% by weight or more is preferable from the viewpoint of crosslinkability, and 80% by weight or less is preferable from the viewpoint of mechanical strength.
The component (D-3) used in the present invention is a vinyl monomer added to control the crosslinking reaction rate, preferably a radical polymerizable vinyl monomer, an aromatic vinyl monomer, Unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile, ester monomers such as acrylate monomers and methacrylate monomers, unsaturated monomers such as acrylate monomers and methacrylic monomers Examples thereof include unsaturated carboxylic acid anhydrides such as carboxylic acid monomers and maleic anhydride monomers, and N-substituted maleimide monomers.

The component (D-3) is preferably used in an amount of 1 to 80% by weight, more preferably 10 to 50% by weight in the component (D). 1% by weight or more is preferable from the viewpoint of crosslinkability, and 80% by weight is preferable from the viewpoint of mechanical strength.
In the present invention, the most preferable combination (D) of the crosslinking agent is 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane (trade name Perhexa 25B, manufactured by NOF Corporation as a crosslinking initiator. ) Or Nippon Oil & Fats Co., Ltd., 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 and polyfunctional monomer, manufactured by Nippon Kasei Co., Ltd., triallyl isocyanurate (TAIC) Is excellent in mechanical strength and (E) retention when (E) described later is present.

Ingredient (E)
The component (E) is preferably a process oil made of hydrocarbons such as paraffinic, naphthenic and aromatic. In particular, naphthenic hydrocarbon-based process oils are preferred from the viewpoint of compatibility with paraffinic hydrocarbons or rubber. From the viewpoint of heat and light stability, the aromatic hydrocarbon content in the process oil is preferably 10% or less, more preferably 5% or less, in terms of the carbon number ratio of ASTM D2140-97. Most preferably, it is 1% or less.
These components (E) are used for adjusting the hardness and flexibility of the composition with respect to a total of 100 parts by weight of components (A), (B) and (C), preferably 5 to 500 parts by weight, preferably 10 to 10 parts by weight. 150 parts by weight are used. Within the above range, the balance between flexibility and bleed resistance is excellent.
In the present invention, when abrasion resistance is required, a polyorganosiloxane having a kinematic viscosity of 5000 centistokes (5 × 10 −3 m ² / sec) or more as defined in JIS-K2410 at 25 ° C. Can be added.
The polyorganosiloxane is in the form of a viscous syrupy to gum, and is not particularly limited as long as it is a polymer containing an alkyl, vinyl and / or aryl group-substituted siloxane unit. Of these, polydimethylsiloxane is most preferred.

The kinematic viscosity (25 ° C.) of the polyorganosiloxane used in the present invention is 5000 CS (5 × 10 −3 m ² / sec) or more, more preferably 10,000 CS (1 × 10 −2 m ² / sec) or more. 10 million ^(10m 2 / sec) below, and most preferably less than 50,000 CS (0.05m ² / sec) over 2 million ^(2m 2 / sec).
In the present invention, the amount of polyorganosiloxane added is preferably 0.01 to 20 parts by weight, more preferably 0 to 100 parts by weight in total with (A), (B) and (C). 0.1 to 10 parts by weight, most preferably 0.5 to 5 parts by weight.
Among the compositions of the present invention, when high-temperature rubber properties such as high-temperature compression set or mechanical strength are required, a crystal nucleating agent classified into phosphate ester-based, sorbitol-based, or carboxylate-based is used. Can be passed on.

Specific examples of the crystal nucleating agent include 2,2′-methylenebis (4,6-di-t-butylphenyl) phosphate, bis (p-methylbenzylidene) sorbitol, bis (p-ethylbenzylidene) sorbitol, etc. Can be mentioned. Specific examples of the inorganic filler include aluminum oxide, iron oxide, titanium oxide, manganese oxide, magnesium oxide, zirconium oxide, zinc oxide, molybdenum oxide, cobalt oxide, bismuth oxide, chromium oxide, tin oxide, antimony oxide, nickel oxide. , Copper oxide, tungsten oxide, etc. or complex (alloy), aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, zeolite, calcium hydroxide, barium hydroxide, basic magnesium carbonate, hydroxide Hydrates of inorganic metal compounds such as hydrates of zirconium and tin oxide, zinc borate, zinc metaborate, barium metaborate, zinc carbonate, magnesium carbonate, mu calcium, calcium carbonate, barium carbonate, kaolin, montmorillonite, bentonite , Ku Chromatography, mica, there may be mentioned talc, among them preferably a plate-like filler, talc, mica, kaolin is particularly preferred.
The amount of the crystallinity improver is preferably 0.01 to 200 parts by weight, more preferably 0.1 to 150 parts by weight with respect to 100 parts by weight as a total of components (A), (B) and (C). The most preferred amount is 0.1 to 100 parts by weight, and the most preferred amount is 0.1 to 50 parts by weight.

Ingredient (F)
In the present invention, a thermoplastic resin (F) other than the component (B) can be blended. The component (F) is not particularly limited as long as it can be dispersed with the components (A), (B), and (C). For example, a polystyrene type, a polyphenylene ether type, a polyvinyl chloride type, a polyamide type, a polyester type, a polyphenylene sulfide type, a polycarbonate type, a polymethacrylate type, etc., or a mixture of two or more types can be used.
In the present invention, component (F) is preferably 1 to 99 parts by weight, more preferably 10 to 90 parts by weight, most preferably 100 parts by weight of the composition comprising components (A), (B) and (C). Preferably it is 20-80 weight part. In addition, the composition of the present invention includes other inorganic fillers, plasticizers, organic / inorganic pigments, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, silicon to the extent that the characteristics are not impaired. Oils, antiblocking agents, foaming agents, antistatic agents and antibacterial agents can be contained.

For the production of the composition of the present invention, it is possible to employ a general method such as a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, etc. used for the production of ordinary resin compositions and rubber compositions. Is possible. In particular, a twin screw extruder is preferably used in order to achieve dynamic crosslinking efficiently. The twin-screw extruder uniformly and finely disperses components (A), (B) and (C), and further adds other components to cause a crosslinking reaction. More suitable for manufacturing.
As a preferred specific example, the composition of the present invention can be produced through the following processing steps. That is, components (A), (B) and (C) are mixed well and charged into a hopper of an extruder. The component (D) may be added from the beginning together with the components (A), (B) and (C), or may be added from the middle of the extruder. The oil may be added from the middle of the extruder, or may be added separately at the beginning and midway. You may add a part of component (A), (B) and (C) from the middle of an extruder. The components (A) and (D) undergo a crosslinking reaction when heated and melted and kneaded in an extruder, and (E) a softener is added to melt and knead to sufficiently achieve a crosslinking reaction and kneading dispersion. After making it take out from an extruder, the pellet of the composition of this invention can be obtained.

Further, a particularly preferable melt extrusion method is a case where a twin screw extruder having a length L in the die direction from the raw material addition portion and having an L / D of 5 to 100 (where D is a barrel diameter) is used. is there. The twin-screw extruder has a plurality of supply parts of a main feed part and a side feed part that have different distances from the tip part, and is provided between the supply parts and between the tip part and the tip part. It is preferable that a kneading portion is provided between the supply portion and the supply portion at a short distance from each other, and the length of the kneading portion is 3D to 10D, respectively.
In addition, one twin-screw extruder of the production apparatus used in the present invention may be a twin-screw co-rotating extruder or a bi-shaft counter-rotating extruder. As for the engagement of the screw, there are a non-engagement type, a partial engagement type, and a complete engagement type, and any type may be used. When applying a low shearing force to obtain a uniform resin at a low temperature, a different direction rotation / partial meshing screw is preferred. When slightly larger kneading is required, a co-rotating and complete meshing screw is preferable. When larger kneading is required, a co-rotating and fully meshing screw is preferred.

The most preferable production method of the composition of the present invention is a method in which the components (A), (B) and (C) are melt-mixed and then crosslinked by the component (D).
The thermoplastic elastomer composition thus obtained can be produced into various molded products by an arbitrary molding method. Injection molding, extrusion molding, compression molding, blow molding, calendar molding, foam molding and the like are preferably used.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these. In these examples and comparative examples, the test methods used for evaluating various physical properties are as follows.
(1) Tensile strength at break [MPa]
Evaluation was performed at 23 ° C. according to JIS K6251.
(2) Molecular weight distribution The molecular weight and molecular weight distribution of the GPC apparatus and measuring method are not particularly limited, but the present inventor used the following apparatus and measuring method.
1. Equipment Waters 150C GPC
2. One column SHODEX AT-807S One Tosoh TSK-GEL GMH-H6 Two, three in total Solvent 1,2,4-trichlorobenzene 4. Measurement temperature 140 ℃
5. Standard material Polystyrene Also, having a peak in the molecular weight distribution is a change curve with respect to the baseline in the GPC measurement, and includes either a broad curve or a sharp curve. The number of peaks is defined by the number of contact points between the tangent line and the curve parallel to the baseline. The peak weight average molecular weight is the peak top of the GPC curve, and refers to the intersection of a tangent line drawn with a straight line parallel to the base line and the curve.
(3) Continuous productivity (quality stability)
Using a twin-screw extruder, the composition is continuously melt extruded for 10 hours, and the tensile breaking strength is measured from the composition obtained every hour, and the continuous productivity (quality stability) is evaluated from the strength change. did. The difference between the maximum and minimum tensile rupture strength at 10 hours was used as an indicator of continuous productivity.

The following were used for each component used in Examples and Comparative Examples.
(A) Crosslinkable rubbery polymer 1) Ethylene / α-olefin copolymer a) Ethylene / propylene / ethylidene norbornene (ENB) copolymer (TPE-1)
It is produced by a method using a metallocene catalyst described in JP-A-3-163088. The composition ratio of ethylene / propylene / ENB of the copolymer is 72/24/4 (weight ratio), and the Mooney viscosity is 100. (Referred to as TPE-1)
b) Ethylene / propylene / ethylidenenorbornene (ENB) copolymer (TPE-2)
It is produced by a method using an ordinary Ziegler catalyst. The composition ratio of ethylene / propylene / ENB of the copolymer is 72/24/4 (weight ratio), and the Mooney viscosity is 105. (Referred to as TPE-2)
c) Copolymer of ethylene and octene-1 (TPE-3)
It was produced by a method using a metallocene catalyst described in JP-A-3-16388. The composition ratio of ethylene / octene-1 in the copolymer is 72/28 (weight ratio), and the Mooney viscosity is 100. (Referred to as TPE-3)

2) Hydrogenated conjugated diene rubber a) Hydrogenated butadiene polymer The hydrogenated butadiene polymer is produced by hydrogenating a butadiene polymer based on the method described in WO01 / 48079. The Mooney viscosity is 100. (Referred to as H-BR)
b) Hydrogenated Styrene / Butadiene Copolymer A styrene / butadiene copolymer is produced by hydrogenation based on the method described in WO01 / 48079. The styrene / butadiene composition ratio of the precursor copolymer is 70/30 (weight ratio), and the Mooney viscosity is 100. (Referred to as H-SBR)

(B) Olefin resin (1) Polypropylene Isotactic homopolypropylene (referred to as PP)
(C) Olefin Wax Produced by a method using a known metallocene catalyst or Ziegler catalyst. Polypropylene wax, polyethylene wax, and ethylene / propylene copolymer wax are shown in Table 1.
(D) Crosslinking agent 1) Crosslinking initiator (D-1)
2,5-dimethyl-2,5-bis (t-butylperoxy) hexane (referred to as POX)
2) Polyfunctional monomer (D-2)
Triallyl isocyanurate (referred to as TAIC)

[Examples 1 to 9 and Comparative Examples 1 to 4]
As the extruder, a twin-screw extruder (40 mmφ, L / D = 47) having an inlet at the center of the barrel is used. As the screw, a double screw having a kneading part before and after the injection port is used.
A mixture having the composition described in Table 1 is introduced into a twin screw extruder, and melt extrusion is performed at 160 ° C. for 10 hours.
A sheet having a thickness of 2 mm is prepared from the composition thus obtained by compression molding at 200 ° C., and the mechanical properties and continuous productivity are evaluated. The results are shown in Table 1.

  The thermoplastic crosslinked rubber composition of the present invention includes automotive parts, automotive interior materials, airbag covers, machine parts, electrical parts, cables, hoses, belts, toys, sundries, daily necessities, building materials, sheets, films, etc. It can be used in a wide range of applications and plays a major role in the industry.

Claims (6)

  A crosslinked thermoplastic crosslinked rubber composition comprising (A) a crosslinkable rubber-like polymer, (B) an olefin resin and (C) an olefin wax, wherein the component (C) is ethylene and 3 to 3 carbon atoms. The weight average molecular weight (Mw) calculated by gel permeation chromatography (GPC) is 3000 to 20000, and the number average molecular weight (Mn) is 20 to 20,000. A thermoplastic crosslinked rubber composition characterized by having a viscosity of 500 to 10,000.   Component (A) contains ethylene and an α-olefin having 3 to 20 carbon atoms, and an ethylene / α-olefin copolymer (A-1) produced using a metallocene catalyst, or a main chain and a side chain One or more types of crosslinks selected from hydrogenated rubber (A-2) in which 50% or more of all olefinic double bonds of the unsaturated rubber comprising a homopolymer and / or copolymer having a double bond are hydrogenated. The thermoplastic crosslinked rubber composition according to claim 1, which is a heat-resistant rubber-like polymer.   The thermoplastic crosslinked rubber composition according to claim 1 or 2, wherein the component (B) is a propylene resin.   The thermoplastic crosslinked rubber composition according to claim 1, wherein the composition comprising the components (A) and (B) is a polymerizable olefin-based crosslinkable rubber composition.   The thermoplastic crosslinked rubber composition according to any one of claims 1 to 4, which is crosslinked by a crosslinking agent (D).   The thermoplastic crosslinked rubber composition according to any one of claims 1 to 5, further comprising an improver (E) selected from a softener, a polyorganosiloxane, and a crystalline nucleating agent.