JP2007254514A - Soft polymer composition - Google Patents

Abstract

To provide a soft polymer composition having excellent heat resistance and scratch resistance.
SOLUTION: A crosslinked thermoplastic crosslinked rubber composition comprising a crosslinkable rubber-like polymer (A) and a thermoplastic resin (B) is added to a copolymer comprising a conjugated diene monomer and an aromatic vinyl monomer. A polymer composition obtained by blending a hydrogenated copolymer (C), which is obtained by hydrogenating a polymer and in which aromatic vinyl monomer portions are mainly bonded in a random manner. A copolymer of a conjugated diene monomer and an aromatic vinyl monomer having an aromatic vinyl monomer content of 50 wt% or more and 90 wt% or less is preferable.
[Selection figure] None

Description

  The present invention relates to a polymer composition. More specifically, the present invention relates to a soft polymer composition excellent in scratch resistance and heat resistance.

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 an elastomer composition, a technique using an olefin-based elastomer (see Patent Documents 1 and 2 below) produced by ethylene-propylene-diene rubber (EPDM) or a metallocene catalyst is known. However, the composition has poor scratch resistance.

  In addition, a composition in which an oil-extended olefin copolymer rubber, an olefin resin, and a softener are crosslinked with an organic peroxide and then a hydrogenated styrene thermoplastic elastomer is added (see Patent Document 3 below), an olefin rubber, A composition in which an olefin resin, a softener, and a filler are partially crosslinked with an organic peroxide, and an A- (BA) n type block copolymer is blended (see Patent Document 4 below), a crosslinked rubber-containing thermoplastic A composition comprising a styrene block copolymer, a softener, and a polyolefin resin (see Patent Document 5 below) is disclosed as an elastomer. Since the composition of the above publication does not necessarily have sufficient heat resistance and scratch resistance, a rubber-based composition that can withstand practical use is required.

JP-A-8-120127 Japanese Patent Laid-Open No. 9-137001 JP-A-3-292342 Japanese Patent Publication No. 3-58381 JP-A-7-11067

  In view of such a current situation, an object of the present invention is to provide a soft polymer composition that does not have the above-described problems, that is, has excellent scratch resistance and heat resistance.

As a result of earnestly examining a soft polymer composition excellent in scratch resistance and heat resistance, the present inventor has surprisingly found that by combining a thermoplastic crosslinked rubber composition and a specific hydrogenated copolymer, The inventors have found that the scratch resistance can be dramatically improved while maintaining the heat resistance of the composition, and the present invention has been completed.
That is, the present invention is a polymer composition as described below.

(1) Copolymerization of a conjugated diene monomer and an aromatic vinyl monomer in a crosslinked thermoplastic crosslinked rubber composition comprising a crosslinkable rubber-like polymer (A) and a thermoplastic resin (B) A polymer composition comprising a hydrogenated copolymer (C) obtained by hydrogenating a coalescence and having aromatic vinyl monomer portions bonded mainly randomly.
(2) The above (C) is a copolymer comprising a conjugated diene monomer and an aromatic vinyl monomer, wherein the aromatic vinyl monomer content is 50 wt% or more and 90 wt% or less ( The polymer composition as described in 1).
(3) An ethylene / α-olefin copolymer (A-1) produced using a metallocene catalyst, wherein (A) contains ethylene and an α-olefin having 3 to 20 carbon atoms, or a main chain and a side chain A kind selected from hydrogenated polymer rubber (A-2) in which 50% or more of all olefinic double bonds of unsaturated rubber comprising a homopolymer and / or copolymer having a double bond are hydrogenated The polymer composition as described in (1) or (2) above, which is a crosslinkable rubbery polymer.
(4) Conjugated diene, wherein (A) comprises (A-1) and (A-2), and (A-2) has an aromatic vinyl monomer content of 50 wt% or more and 90 wt% or less A hydrogenated copolymer obtained by hydrogenating a copolymer comprising a monomer and an aromatic vinyl monomer, and wherein the aromatic vinyl monomer portion is mainly randomly bonded (( The polymer composition according to any one of 1) to (3).
(5) The polymer composition according to any one of (1) to (4), wherein (B) is an olefin resin.
(6) The polymer composition according to any one of (1) to (5), which is crosslinked with a crosslinking agent (D).
(7) The above (1) to (6) further containing at least one additive (E) selected from the group consisting of a softener, a powdery compound that does not melt at 250 ° C., a styrene thermoplastic elastomer, and a resin wax. The polymer composition according to any one of the above.

  The soft polymer composition of the present invention has the effect of being excellent in heat resistance and scratch resistance.

The present invention will be specifically described below.
The molded article of the present invention comprises a crosslinked thermoplastic crosslinked rubber composition comprising a crosslinkable rubber-like polymer (A) and a thermoplastic resin (B), and a specific hydrogenated copolymer.
Here, it is important that (A) and (B) be crosslinked while maintaining thermoplasticity. By crosslinking the above components, heat resistance and scratch resistance are excellent in order to maintain a stable morphology even under high shear.
And when (C) which is not bridge | crosslinked is added to a thermoplastic crosslinked rubber composition, it discovered that flaw resistance improved remarkably and completed this invention.
Hereinafter, each component of the present invention will be described in detail.

(A) Component In the present invention, the crosslinkable rubber-like polymer (A) is obtained by hydrogenating a diene rubber such as polybutadiene, poly (styrene-butadiene), poly (acrylonitrile-butadiene), and the diene rubber. Saturated polymer rubber (hydrogenated copolymer rubber), isoprene rubber, chloroprene rubber, acrylic rubber such as polybutyl acrylate, ethylene-propylene copolymer, ethylene-octene copolymer, ethylene-propylene-diene monomer Examples thereof include a crosslinked rubber or non-crosslinked rubber such as an ethylene / α-olefin copolymer such as a terpolymer (EPDM), and a thermoplastic elastomer containing the rubber component.
Further, (A) preferably has a glass transition temperature (Tg) of −10 ° C. or lower.
And (A) Mooney viscosity (ML) (ISO 289-1985 (E) conformity) measured at 100 degreeC has preferable 20-150, More preferably, it is 50-120.

  In the present invention, one of the preferred crosslinkable rubbery polymers (A) is an ethylene / α-olefin copolymer, which is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. Is more preferable. 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.

  Moreover, the crosslinkable rubber-like polymer (A) can contain a monomer having an unsaturated bond, if necessary, such as conjugated diolefins such as butadiene and isoprene, 1,4-hexadiene and the like. Non-conjugated diolefins, cyclic diene compounds such as dicyclopentadiene and norbornene derivatives, and acetylenes are exemplified. 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 (A-1) in (A)), which is one of the preferred copolymers of (A), is known. It is preferable to produce using a metallocene catalyst.
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 (A-1) (A) used in the present invention preferably has an α-olefin copolymerization ratio of 1 to 60% by weight, more preferably 10 to 50% by weight. %, Most preferably 20 to 45% by weight. The copolymerization ratio of the 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 (A-1) in (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 (A-1) of (A) used in the present invention preferably 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.

Further, the ethylene / α-olefin copolymer (A-1) of (A) desirably has a melting point peak of a thermobalance (DSC) at room temperature or higher. 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 (A-1) used in the present invention is 0.01-100 g / 10 min (190 ° C., 2.16 kg load (0.212 Pa). )) Is preferably used, and more preferably 0.2 to 10 g / 10 min. From the viewpoint of crosslinkability of the thermoplastic elastomer 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, another preferred copolymer (A) is a hydrogenated polymer rubber (hereinafter referred to as hydrogenated polymer rubber (A-2)). The hydrogenated polymer rubber (A-2) is a homopolymer rubber of at least one conjugated diene monomer or a copolymer rubber comprising a conjugated diene monomer and an aromatic vinyl monomer. A hydrogenated polymer rubber in which the hydrogenation rate of all double bonds of the random copolymer is 50% or more is preferable, and in particular, a polymer and / or copolymer having double bonds in the main chain and side chains Preferably, the unsaturated polymer rubber is a hydrogenated polymer rubber in which 50% or more of all olefinic double bonds are hydrogenated.

  In the hydrogenated polymer rubber, if necessary, for example, a single quantity copolymerizable with a conjugated diene such as an olefin, methacrylate ester, acrylate ester, unsaturated nitrile, or vinyl chloride monomer. The body (hereinafter referred to as 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 polymer rubber as (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. In addition, a plurality of blocks having different vinyl bond contents may be included. 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 polymer rubber are 50% or more, preferably 90% or more, more preferably 95% or more, and the remaining double bonds of the main chain are 5% or less, The residual double bond of the side chain is 5% or less. Specific examples of such hydrogenated polymer rubbers include rubbers obtained by partially or completely hydrogenating diene rubbers such as polybutadiene, poly (styrene-butadiene), poly (acrylonitrile-butadiene), polyisoprene, and polychloroprene. In particular, hydrogenated butadiene-based or hydrogenated isoprene-based rubber is preferable.

  Such a hydrogenated polymer 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), Hung Yu Chen, J. Polym. Sci. Polym. Letter Ed , 15,271 (1977), or hydrogenation using a toluenesulfonyl hydrazide or an organic cobalt-organic aluminum catalyst or an organic nickel-organic aluminum catalyst described in Japanese Patent Publication No. 42-8704 And the like.

  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 polymer 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 polymer rubber preferably has crystallinity, and the endothermic peak calorific value, which is an index of the 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 crosslinkable rubber-like polymer (A) used in the present invention may be used by mixing 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-reduced molecular weight of 150,000 or less in the crosslinkable rubber-like polymer (A) is preferably 30% by weight or less, more preferably 25% or less, and still more preferably. 20% or less, most preferably 15% or less, and most preferably 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 crosslinkable rubber-like polymer (A), the whole is so that the portion having a molecular weight of 150,000 or less is 30% or less. And 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.

  In the present invention, the degree of crosslinking obtained from the xylene-insoluble matter of (A) is preferably 10% or more, more preferably 30%, and most preferably 70%. When it is within the above range, excellent injection moldability, flexibility and scratch resistance are exhibited.

Component (B) In the present invention, the thermoplastic resin (B) is not particularly limited. For example, polyolefin-based, polystyrene-based, polyphenylene ether-based, polyvinyl chloride-based, polyamide-based, polyester-based, polyphenylene sulfide-based, polycarbonate A single type or a mixture of two or more types of polymethacrylates and the like can be used.
Among them, an olefin resin is preferable as (B), for example, a copolymer resin containing ethylene or / and α-olefin alone or in combination of 2 to 20 carbon atoms such as ethylene or propylene resin, and the like. Particularly preferred is a propylene-based resin.

  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 the component (B), a propylene random copolymer resin such as a random copolymer resin of ethylene and propylene, which is a cross-linked olefin resin (B-1), or decomposed with (B-1) A combination with a propylene block copolymer resin or a homopolypropylene resin, which is a type olefin resin (B-2), 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 (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 Show properties.
(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.
(B) may be a combination of a plurality of components (B-1) and (B-2).

  Random copolymer resin with α-olefin mainly composed of propylene among (B-1) can be produced by high pressure method, slurry method, gas phase method, bulk method, solution method, etc. As the 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 Application No. 0969433 or US Pat. No. 5,1984,401, and after introducing propylene into a reactor equipped with a stirrer, the catalyst is discharged from a nozzle. Add to gas phase or liquid phase. 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.

  In the present invention, each component in 100 parts by weight of the composition comprising (A) and (B), (A) is preferably 1 to 99% by weight, more preferably 10 to 80% by weight, most preferably 20 to 70% by weight, and (B) is preferably 1 to 99% by weight, more preferably 90 to 20% by weight, and most preferably 80 to 30% by weight. Within the above range, the balance between injection moldability and scratch resistance is improved.

  In the present invention, the composition comprising (A) and (B) may be one obtained by melting and mixing separate (A) and (B) with an extruder, and (A) and (B). A polymerization type olefin composition produced during polymerization may be used. Such a polymerization-type olefin composition is a thermoplastic elastomer produced by a polymerization method comprising a dispersed phase of olefin rubber and a continuous phase of olefin resin. Usually, it is produced by a multistage polymerization method.

  In the present invention, the multistage polymerization method means a polymerization method in which a plurality of types of polymers can be continuously produced by performing multistage polymerization of two or more stages, instead of completing the polymerization once. However, this method is different from the usual polymer blending method in which a mixed resin composed of different kinds of polymers is obtained using a mechanical method.

  The olefinic crosslinkable rubber composition obtained by the multistage polymerization method is a copolymer obtained by multistage polymerization of (1) hard segment and (2) soft segment in a reactor. (1) The hard segment is typically a propylene homopolymer block or a copolymer block of propylene and an α-olefin, such as propylene / ethylene, propylene / 1-butene, propylene / ethylene / 1- Examples include binary or ternary copolymer blocks such as butene. The (2) soft segment is typically an ethylene homopolymer block and a copolymer block of ethylene and α-olefin, such as ethylene / propylene, ethylene / 1-butene, ethylene / propylene / 1-butene. Binary or ternary copolymer blocks such as

Component (C) In the present invention, the hydrogenated copolymer (C) is obtained by hydrogenating a copolymer comprising a conjugated diene monomer and an aromatic vinyl monomer, and the aromatic vinyl monomer. The body part is mainly bonded randomly, and preferably from a conjugated diene monomer and an aromatic vinyl monomer having an aromatic vinyl monomer content of 50% by weight or more and 90% by weight or less. It is a copolymer.

Regarding the hydrogenation rate of (C), a hydrogenated copolymer rubber in which the hydrogenation rate of all double bonds of the random copolymer is 50% or more is preferable, and in particular, it has double bonds in the main chain and side chains. A hydrogenated copolymer rubber in which 50% or more of all olefinic double bonds of the unsaturated polymer rubber made of a polymer and / or copolymer are hydrogenated is preferable.
Although the essential requirements of (C) in the present invention are as described above, the requirements described in (A-2) above are satisfied as necessary for other requirements.
In the present invention, (C) is used in an amount of 5 to 500 parts by weight, preferably 10 to 150 parts by weight, based on a total of 100 parts by weight of (A) and (B). Within the above range, scratch resistance is excellent.

(D) Component It is preferable that the thermoplastic crosslinked rubber composition in the polymer of the present invention is crosslinked with a crosslinking agent (D).
The crosslinking agent (D) contains the crosslinking initiator (D-1) as an essential component, and contains a polyfunctional monomer (D-2) and a monofunctional monomer (D-3) as necessary. The crosslinking agent (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 (A) and (B). Within the above range, the level of cross-linking is increased and the wear resistance of the composition is improved.

  Here, examples of the crosslinking initiator (D-1) include radical initiators such as organic peroxides and organic azo compounds. 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; di-t-butyl peroxide, dicumyl peroxide, -Butyl cumyl peroxide, α, α'-bis (t-butylperoxy-m-isopropyl) benzene, α, α'-bis (t-butylperoxy) diisopropylbenzene, 2,5-dimethyl-2,5 -Dialkyl peroxides such as bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3; acetyl peroxide, isobutyryl peroxide, octanoyl Diacyl peroxides such as peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and m-trioyl peroxide; t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, di-t-butyl peroxyisophthalate, 2,5 -Peroxyesters such as dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, and cumylperoxyoctate; and t-butylhydro Hydroperoxides such as peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide and 1,1,3,3-tetramethylbutyl peroxide To mention That.

  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 (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 polyfunctional monomer (D-2) contained in the crosslinking agent (D) as necessary is preferably a radical polymerizable functional group as the 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'-dibenzoylquinonedioxime, 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 (D-3) used in the present invention is a vinyl monomer, preferably a radical polymerizable vinyl monomer, and an unsaturated nitrile such as an aromatic vinyl monomer, acrylonitrile, or methacrylonitrile. Monomers, ester monomers such as acrylic acid ester monomers and methacrylic acid ester monomers, unsaturated carboxylic acid monomers such as acrylic acid monomers and methacrylic acid monomers, maleic anhydride Examples thereof include unsaturated carboxylic acid anhydrides such as monomers, low molecular weight monomers such as N-substituted maleimide monomers, and macromonomers in which a vinyl group such as a methacryloyl group is substituted at one end of the polymer. it can.
The (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 of the crosslinking agent (D) is 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane (trade name: Perhexa 25B, manufactured by NOF Corporation as a crosslinking initiator. ) Or 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 manufactured by Nippon Oil & Fats Co., Ltd. and triallyl isocyanurate (TAIC) manufactured by Nippon Kasei Co., Ltd. )) Is excellent in mechanical strength and retainability of the softener when the softener described below is present.

(E) Component In the present invention, if necessary, at least one additive (E) selected from the group consisting of a softener, a powdery compound that does not melt at 250 ° C., a styrene thermoplastic elastomer, and a resin wax is added. be able to.
The softener is preferably a process oil composed of paraffinic, naphthenic, aromatic hydrocarbons. 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 softeners are used in an amount of 5 to 500 parts by weight, preferably 10 to 150 parts by weight, based on 100 parts by weight of the total of (A) and (B). Within the above range, the balance of dispersibility, flexibility and bleed resistance is excellent.

In the present invention, when abrasion resistance is required, polyorganosiloxane (F) can be added as necessary, and the kinematic viscosity at 25 ° C. of JIS-K2410 is 5000 centistokes (5 The polyorganosiloxane which is more than x10 < ^-3 > m < ² > / sec) is preferable.

The polyorganosiloxane is in the form of a viscous syrup or gum and is not particularly limited as long as it is a polymer containing alkyl, vinyl and / or aryl group-substituted siloxane units. 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). ) 10,000,000 CS ^(10m 2 / sec), less is less than most preferably 50,000 CS (0.05m ² / sec) over 2 million ^CS (2m 2 / sec).
In this invention, it is preferable that the addition amount of (F) is 0.001-20 weight part with respect to a total of 100 weight part of (A) and (B), More preferably, it is 0.1-10. Parts by weight, most preferably 0.5 to 5 parts by weight.

  In the present invention, other inorganic fillers, plasticizers, organic / inorganic pigments, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, silicone oils, foaming agents to the extent that they do not impair their characteristics It is possible to contain an antistatic agent and an antibacterial agent.

  For the production of the polymer composition of the present invention, a general method such as a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder or the like used for the production of ordinary resin compositions and elastomer compositions should be adopted. Is possible. In particular, a twin screw extruder is preferably used in order to achieve dynamic crosslinking efficiently. In the twin-screw extruder, (A) and (B) are uniformly and finely dispersed, and other components are added to cause a crosslinking reaction, thereby continuously producing the composition of the present invention. Is more suitable.

  The polymer composition of the present invention may be prepared by first producing a thermoplastic crosslinked rubber composition comprising (A) and (B), and then adding (C) and melt-mixing them. A thermoplastic crosslinked rubber composition composed of (A) and (B) may be produced in the pre-use stage, (C) may be added with a side feeder, and melt mixed.

  The thermoplastic crosslinked rubber composition can be produced through the following processing steps as a suitable specific example. That is, (A) ((A-1) and (A-2)) and (B) are mixed well and put into a hopper of an extruder. At this time, it is preferable that (A-1) and (A-2) are simultaneously added to the extruder and melt-kneaded. (D) may be added from the beginning together with (A) and (B), 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 (A) and (B) from the middle of an extruder. When heated and melted and kneaded in an extruder, the above (A) and (D) undergo a crosslinking reaction, and (E) a softening agent is added to melt and knead to sufficiently enhance the crosslinking reaction and kneading dispersion. Thereafter, by taking out from the extruder, pellets of the thermoplastic crosslinked rubber composition 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 portions of a main feed portion and a side feed portion that are different in distance from the tip portion, and is provided between the plurality of supply portions and between the tip portion and the above It is preferable that a kneading portion is provided between the tip portion and the supply portion at a short distance, 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 screws, 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 type screw is preferred. When slightly larger kneading is required, the same-direction rotating / completely meshing type screw is preferable. When larger kneading is required, a co-rotating and fully meshing screw is preferable.
The most preferable production method of the thermoplastic crosslinked rubber composition of the present invention is a method in which (A) and (B) are uniformly melt-mixed and then crosslinked by (D).

  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. Heat resistance (TMA method)
Using TMA100 and SSC5000 manufactured by Seiko Denshi Kogyo Co., Ltd., the temperature (° C.) at which a probe with a diameter of 1 mm in a load of 20 g / mm ² enters 100 μm is defined as a softening temperature, which is an index of heat resistance.

2. Flexibility (Recovery angle)
A 2mm thick sheet is bent 180 degrees in a 23 ° C room, placed on a horizontal surface in that state, and then a 1kg weight is removed after 10 seconds. After the shape has fully recovered, the angle between the horizontal surface and the bent sheet is measured. And the recovery angle. The smaller the recovery angle, the higher the recovery and the higher the flexibility.
Further, the flexibility is determined according to the following criteria from the feel of the sheet.
◎ Very good ○ Good △ Good, but a little hard × Hard, not flexible

3. Scratch resistance The scratches on the sheet, which are formed by dropping a wedge having a tip of 10 mm in length and 1 mm in width and a weight of 1000 g onto a sheet from a height of 5 cm, are visually evaluated according to the following criteria.
◎ Extremely good ◯ Good △ Good, but scratches are conspicuous × Scratches are remarkable In addition, when two symbols are used in combination, such as ◎ ○, the middle is shown.
At the same time, the flaw depth is measured by scanning the flaw of the sheet with a laser beam.

The following were used for each component used in Examples and Comparative Examples.
(A) Crosslinkable rubbery polymer (A-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) produced by a method using a normal 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)

(A-2) Hydrogenated polymer rubber a) Hydrogenated butadiene polymer The hydrogenated butadiene polymer is produced by hydrogenating a butadiene polymer based on the method described in WO 01/48079. The Mooney viscosity is 100. (Referred to as H-BR)
b) Hydrogenated styrene / butadiene random copolymer The hydrogenated styrene / butadiene random copolymer is produced by hydrogenating a styrene / butadiene random copolymer based on the method described in WO 01/48079. 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) Thermoplastic resin Polypropylene Isotactic homopolypropylene (referred to as PP) MFR: 0.5 g / 10 min (230 ° C., 2.16 kg load)

(C) Hydrogenated copolymer obtained by hydrogenating a copolymer comprising a conjugated diene monomer and an aromatic vinyl monomer, and in which the aromatic vinyl monomer portions are mainly bonded randomly. Combined (C-1) HBR
(C ') Hydrogenated styrene / butadiene block copolymer (C'-1) Commercially available SEBS (styrene / ethylene butylene = 70/30 weight ratio) (referred to as SEBS-1)
(C′-2) Commercially available SEBS (styrene / ethylene butylene = 30/70 weight ratio) (referred to as SEBS-2)

(D) Crosslinking agent (D-1) Crosslinking initiator 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane (referred to as POX)
(D-2) Polyfunctional monomer Triallyl isocyanurate (referred to as TAIC)

[Examples 1 to 5 and Comparative Examples 1 to 3]
As the extruder, a twin screw extruder (cylinder inner diameter (D) = 40, screw length (L) (L / D) = 50) 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. In the addition procedure, (A), (B), and (D) are added in the previous stage, melt-kneaded, and then (C) is added with a side feeder.
The composition shown in Table 1 is melt-extruded at a cylinder temperature of 160 ° C. and pelletized. A 2 mm thick sheet is produced from the composition thus obtained at 200 ° C. using a T-die extruder and subjected to various evaluations. The results are shown in Table 1.

  According to Table 1, it is more flexible and scratch-resistant when the crosslinked polymer is first produced and then blended with (C) than when the rubbery polymer (C) is crosslinked with (A) during dynamic crosslinking. It turns out that it is excellent. In addition, (A) is a copolymer rubber produced using a metallocene-based catalyst and / or a hydrogenated polymer rubber bonded randomly, and (C) is a conjugated diene monomer bonded randomly. It can be seen that in the case of a hydrogenated copolymer composed of an aromatic vinyl monomer, the heat resistance is remarkably improved in addition to the above excellent characteristics.

  The polymer composition of the present invention includes automobile parts, automobile interior materials, airbag covers, machine parts, electrical parts, cables, hoses, belts, toys, sundries, daily necessities, building materials, sheets, films and the like. It can be used for a wide range of purposes and plays a major role in the industry.

Claims (7)

  A copolymer comprising a conjugated diene monomer and an aromatic vinyl monomer is added to a crosslinked thermoplastic crosslinked rubber composition comprising a crosslinkable rubber-like polymer (A) and a thermoplastic resin (B). A polymer composition comprising a hydrogenated copolymer (C) which is added and the aromatic vinyl monomer portion is mainly bonded randomly.   2. The copolymer (C) is a copolymer comprising a conjugated diene monomer and an aromatic vinyl monomer, wherein the aromatic vinyl monomer content is 50 wt% or more and 90 wt% or less. Polymer composition.   An ethylene / α-olefin copolymer (A-1) produced using a metallocene catalyst, wherein (A) contains ethylene and an α-olefin having 3 to 20 carbon atoms, or double in the main chain and side chain One or more types of crosslinks selected from hydrogenated polymer rubber (A-2) in which 50% or more of all olefinic double bonds of the unsaturated rubber comprising a homopolymer having a bond and / or a copolymer are hydrogenated The polymer composition according to claim 1, wherein the polymer composition is a conductive rubber-like polymer.   (A) is composed of (A-1) and (A-2), and (A-2) is an aromatic vinyl monomer content of 50 wt% or more and 90 wt% or less. A hydrogenated copolymer obtained by hydrogenating a copolymer comprising an aromatic vinyl monomer and an aromatic vinyl monomer portion bonded mainly randomly. The polymer composition according to any one of the above.   (B) is an olefin resin, The polymer composition in any one of Claims 1-4.   The polymer composition according to any one of claims 1 to 5, which is crosslinked with a crosslinking agent (D).   Furthermore, at least 1 type of additive (E) chosen from the group which consists of a softening agent, the powdery compound which does not melt at 250 degreeC, a styrene-type thermoplastic elastomer, and a resin-type wax was contained in any one of Claims 1-6. Polymer composition.