JP2002012703A - Rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition which is good in processability, dimension stability, and the vulcanized rubber obtained from the rubber composition is excellent in abrasion resistance, tensile strength and usable for belts, hoses, tires, etc. SOLUTION: This rubber composition comprises [1] a cross-linked rubber particle component wherein the toluene-insoluble portion is >=50 mass% and the number average particle diameter is 3-1,000 nm, and [2] a noncross-linked rubber component wherein the toluene-insoluble portion is <20 mass%. The cross-linked rubber particle component is made of a polymer comprising one of (1) a conjugated diene unit, (2) a conjugated diene unit and an α,β-unsaturated nitrile unit and (3) a conjugated diene unit and an acrylate unit, as well as a monomer unit having at least two polymerizable unsaturated groups. The noncross-linked rubber component is a polymer comprising one of (a) a conjugated diene unit, (b) (a) and an aromatic vinyl unit, (c) (a) and an α,β-unsaturated nitrile unit, (d) (a) and an acrylate unit, and (e) an ethylene unit and a 3-12C α-olefin unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rubber composition comprising a crosslinked rubber particle component and a non-crosslinked rubber component as essential components.
The rubber composition of the present invention is excellent in processability, particularly excellent in workability and dimensional stability when silica is used as a reinforcing agent.
The vulcanized rubber obtained by vulcanizing this rubber composition can be used in various industrial applications as rubber products such as belts, hoses, rolls and tires.

[0002]

2. Description of the Related Art Conventionally, as raw material rubbers used in rubber products, (A) a polymer represented by butadiene rubber, isoprene rubber, chloroprene rubber and natural rubber, whose repeating unit consists only of conjugated diene units, B) a polymer having a conjugated diene unit and an aromatic vinyl unit as a repeating unit, represented by styrene-butadiene copolymer rubber, styrene-isoprene copolymer rubber, styrene-isoprene-butadiene copolymer rubber,

[0003] (C) A polymer represented by an acrylonitrile-butadiene copolymer rubber, which essentially comprises a conjugated diene unit and an α, β-unsaturated nitrile unit as repeating units, and (D) an acrylic rubber. A polymer consisting essentially of an acrylate unit as a repeating unit, (E) a polymer comprising ethylene, an α-olefin having 3 to 12 carbon atoms, and, if necessary, a non-conjugated polyene as a repeating unit typified by ethylene-propylene rubber. Coalescence, etc. are frequently used.

If these raw rubbers are used and silica is used as a reinforcing agent, colored rubber products other than black can be obtained.
In addition, heat generation can be suppressed to a low level as the performance of the compounded rubber using them. However, when silica is used, there is a problem that the tensile strength and abrasion resistance of the vulcanized rubber are reduced as compared with carbon black. Further, as another problem when silica is blended, the processability during kneading and the decrease in the integrity of the compound, the smoothness of the surface when the compound is made into a sheet by a roll or the like is not sufficient, and the sheet edge is also insufficient. And it shrinks considerably with cooling.

[0005] One possible reason for such a problem is that silica is not sufficiently dispersed and aggregates. In a rubber composition in which silica is not sufficiently dispersed, not only the intended reinforcing effect due to the blending of the reinforcing agent is not obtained, but also heat generation due to the interaction between the poorly dispersed silica particles occurs, and the processability is greatly reduced. May drop. The reason for the poor dispersion of silica is that silica has a strong self-interaction and is likely to be aggregated compared to carbon black, and that most of the raw rubber is composed of carbon and hydrogen as main components, and compared to silica. It is considered that the polymer has low polarity and thus has low affinity with silica.

In order to increase the affinity between silica and a hydrocarbon rubber, the use of a conjugated diene rubber into which a functional group having an affinity for silica has been introduced has been studied. For example, a conjugated diene rubber having a hydroxyl group introduced therein (WO 96/23027) and a conjugated diene rubber having an alkoxysilyl group introduced therein (Japanese Patent Laid-Open No. 9-20862).
No. 3) and a conjugated diene rubber in which an alkoxysilyl group and an amino group or a hydroxyl group are introduced (Japanese Patent Application Laid-Open No. 9-208633). But,
Many of the conjugated diene rubbers having these functional groups introduced are:
When the silica is mixed, it is strongly agglomerated with the silica, and thus has problems such as poor dispersion, large heat generation during processing, and poor processability.

[0007] A silane coupling agent is generally blended for the purpose of preventing aggregation of silica and uniformly dispersing the silica. Thereby, the dispersibility of silica is improved to some extent, and the processability of the rubber composition and the tensile strength and wear resistance of the vulcanized rubber are considerably improved. However, problems such as the smoothness of the sheet surface and sheet edge and the shrinkage of the sheet during cooling have not been sufficiently improved. Further, in order to sufficiently improve the processability, tensile strength, wear resistance and the like, it is necessary to add a considerable amount of a silane coupling agent to silica at about 8 to 15% by mass. Is expensive and causes an increase in the cost of the rubber composition.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and has good workability at the time of kneading, a smooth sheet surface and a uniform sheet edge. An object of the present invention is to provide a rubber composition having excellent processability and workability, such as low shrinkage upon cooling. A vulcanized rubber obtained by vulcanizing this rubber composition has excellent tensile strength, wear resistance and the like.

[0009]

In order to solve the above-mentioned problems, various investigations have been conducted. As a result, it was found that silica was used as a reinforcing agent by adding a crosslinked rubber particle component having a specific composition to a rubber composition. Even so, it was found that a rubber composition having excellent workability at the time of kneading, good smoothness of the sheet surface and sheet edge, and little shrinkage of the sheet during cooling can be obtained. It was also found that the use of this rubber composition can provide a vulcanized rubber having low heat build-up and sufficient tensile strength and abrasion resistance. Further, even if the amount of the silane coupling agent is reduced or the silane coupling agent is not added, the processability, tensile strength, etc. can be sufficiently improved to such an extent that practically no problem occurs. Was found. The present invention has been made based on such findings.

[0010] The rubber composition of the present invention has [1] a toluene insoluble content of 50% by mass or more and a number average particle size of 3 to 10%.
A rubber composition comprising a crosslinked rubber particle component having a diameter of 00 nm and [2] a non-crosslinked rubber component having a toluene insoluble content of less than 20% by mass, wherein the crosslinked rubber particle component is conjugated as a repeating unit (1). A polymer comprising a diene unit and a monomer unit having at least two polymerizable unsaturated groups,
(2) As a repeating unit, a conjugated diene unit and α, β
A polymer comprising an unsaturated nitrile unit and a monomer unit having at least two polymerizable unsaturated groups, (3) a conjugated diene unit, an acrylate unit, and at least two polymerizable units as repeating units. At least one of a polymer having a monomer unit having an unsaturated group,
The non-crosslinked rubber component is (a) a polymer whose repeating unit is composed of only a conjugated diene unit, (b) a polymer having a conjugated diene unit and an aromatic vinyl unit as a repeating unit, and (c) a repeating unit having: Conjugated diene units and α,
at least one of a polymer having a β-unsaturated nitrile unit, (d) an acrylic rubber, and (e) a polymer having an ethylene unit and an α-olefin unit having 3 to 12 carbon atoms as a repeating unit. It is characterized by being.

The "crosslinked rubber particle component" comprises (A) a monomer forming a conjugated diene unit (hereinafter, referred to as "monomer"), (B) a monomer, and an α, β-unsaturated A monomer that forms a nitrile unit (hereinafter, referred to as “monomer”);
And (C) a monomer, one of monomers forming an acrylate unit (hereinafter, referred to as “monomer”), and (D) a monomer having at least two polymerizable unsaturated groups. And a monomer that forms a body unit (hereinafter referred to as “monomer”).

This crosslinked rubber particle component has a toluene-insoluble content of 50% by mass or more, which is obtained from a solid content in a filtrate which is immersed in 100 ml of toluene at room temperature for 24 hours and then filtered through a 100-mesh wire gauze. It is preferable that the amount is at least mass%. If the toluene insoluble content is less than 50% by mass, the processability is not sufficiently improved. In addition, a laser particle size analysis system (manufactured by Otsuka Electronics Co., Ltd., model "LP"
A-3100 ") has a number average particle diameter of 3 to
It is preferably 1000 nm, particularly preferably 10 to 500 nm, and more preferably 30 to 100 nm. When the particle diameter exceeds 1000 nm, the crosslinked rubber particle component is not sufficiently dispersed in the rubber composition, and the processability is reduced. The particle size of the crosslinked rubber particle component can be controlled by the type and amount of the emulsifier and the electrolyte used in the emulsion polymerization.

As the crosslinked rubber particle component, a monomer and a monomer described below, and a monomer described below optionally used together are used, and a polymerization method such as emulsion polymerization or suspension polymerization is used. Can be manufactured. That is, monomers, which are generally used in the production of rubber and the like by emulsion polymerization,
By performing polymerization in an aqueous medium such as a monomer and a monomer in the presence of a monomer having at least two polymerizable functional groups and capable of introducing a crosslinked structure into a molecular chain by copolymerization, The crosslinked rubber particle component constituting the rubber composition of the present invention can be produced.

As the monomer, 1,3-butadiene,
Isoprene (2-methyl-1,3-butadiene), 2,
3-dimethyl-1,3-butadiene and chloroprene (2-chloro-1,3-butadiene) and the like.
One of these monomers may be used alone, or two or more thereof may be used in combination. In the repeating unit in the crosslinked rubber particle component, the content of the unit composed of a monomer is 30 to 99.8% by mass, particularly 40 to 99.8% by mass.
It is preferred that When the content of the monomer unit is less than the lower limit, the processability may not be sufficiently improved, and the tensile strength of the vulcanized rubber tends to decrease.

Examples of the monomer include acrylonitrile, methacrylonitrile, and derivatives thereof, and acrylonitrile is preferred. One of these monomers may be used alone, or two or more thereof may be used in combination. In the repeating unit in the crosslinked rubber particle component, the content of the unit composed of a monomer is preferably 69.99% by mass or less, particularly preferably 69.99% by mass or less.
When the content of the monomer unit exceeds the upper limit, the kneading processability of the rubber composition, the smoothness of the sheet surface and edges, the shrinkage of the sheet upon cooling, the vulcanizability and the like tend not to be sufficiently improved. It is in.

The monomers include (1) methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and iso- (meth) acrylate.
Propyl, n-butyl (meth) acrylate, (meth)
-Iso-butyl acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, (meth) Nonyl acrylate, alkyl (meth) acrylates such as decyl (meth) acrylate, and (2) methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, ( Examples thereof include alkoxyalkyl (meth) acrylates such as ethoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate, and butoxyethyl (meth) acrylate. These monomers may use only one kind of each kind, two or more kinds may be used in combination, or different kinds may be used in combination.

In the repeating unit in the crosslinked rubber particles, the content of the unit composed of a monomer is preferably 69.99% by mass or less, particularly preferably 59.99% by mass or less. When the content of the monomer unit exceeds the upper limit, the kneading processability of the rubber composition, the smoothness of the sheet surface and edges, the shrinkage of the sheet upon cooling, the vulcanizability and the like tend not to be sufficiently improved. It is in.

As the monomers, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth)
Acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, Examples include divinylbenzene, diisopropenylbenzene, and trivinylbenzene. One of these monomers may be used alone, or two or more thereof may be used in combination.

In the repeating unit in the crosslinked rubber particle component, the content of the unit composed of a monomer is 0.01 to 10%.
It is preferably from 0.1 to 10% by mass, especially from 0.1 to 10% by mass. When the content of the monomer unit is less than 0.01% by mass, the degree of crosslinking of the crosslinked rubber particle component does not become sufficiently high, and the particle shape cannot be maintained during processing, so that the rubber composition is processed. May not improve. On the other hand, if the content exceeds 10% by mass, the tensile strength of the vulcanized rubber tends to decrease.

The crosslinked rubber particle component has at least a part thereof as a repeating unit, one polymerizable unsaturated group, an amino group, a hydroxyl group, an epoxy group and a carboxylic acid group (CO ₂ H and / or CO ₂ ^- ) Containing 0.1 to 30% by mass of a monomer unit having at least one functional group. Incidentally, the monomer forming this monomer unit is referred to as "monomer".

Among the monomers, the monomer having an amino group is preferably a monomer having a tertiary amino group,
(A) dimethylaminomethyl (meth) acrylate, diethylaminomethyl (meth) acrylate, 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2- (di-n-propylamino) ethyl (meth) ) Acrylate, 2-dimethylaminopropyl (meth) acrylate, 2-diethylaminopropyl (meth) acrylate, 2- (di-n-
Propylamino) propyl (meth) acrylate, 3-
Dimethylaminopropyl (meth) acrylate, 3-diethylaminopropyl (meth) acrylate and 3-
Dialkylaminoalkyl (meth) acrylates such as (di-n-propylamino) propyl (meth) acrylate;

(B) N-dimethylaminomethyl (meth)
Acrylamide, N-diethylaminomethyl (meth) acrylamide, N- (2-dimethylaminoethyl) (meth) acrylamide, N- (2-diethylaminoethyl) (meth) acrylamide, N- (2-dimethylaminopropyl) (meth) Acrylamide, N- (2-diethylaminopropyl) (meth) acrylamide, N-
N-dialkylaminoalkyl group-containing unsaturated amides such as (3-dimethylaminopropyl) (meth) acrylamide and N- (3-diethylaminopropyl) (meth) acrylamide;

(C) N, N-dimethyl-p-aminostyrene, N, N-diethyl-p-aminostyrene, dimethyl (p-vinylbenzyl) amine, diethyl (p-vinylbenzyl) amine, dimethyl (p- Vinylphenethyl) amine, diethyl (p-vinylphenethyl) amine, dimethyl (p-vinylbenzyloxymethyl) amine, dimethyl [2- (p-vinylbenzyloxy) ethyl] amine, diethyl (p-vinylbenzyloxymethyl) amine , Diethyl [2- (p-vinylbenzyloxy) ethyl] amine, dimethyl (p-vinylphenethyloxymethyl) amine, dimethyl [2- (p-vinylphenethyloxy) ethyl] amine, diethyl (p-vinylphenethyloxymethyl) amine ) Amine, diethyl [2-
(P-vinylphenethyloxy) ethyl] amine, 2-
And tertiary amino group-containing vinyl aromatic compounds such as vinylpyridine, 3-vinylpyridine and 4-vinylpyridine. Among them, dialkylaminoalkyl (meth) acrylates and tertiary amino group-containing vinyl aromatic compounds are preferred. These monomers having an amino group may use only one of each kind,
Two or more types can be used in combination, and different types can be used in combination.

As the monomer having a hydroxyl group,
(A) 2-hydroxyethyl (meth) acrylate, 2
Hydroxyalkyls such as -hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; (Meth) acrylates; (b) mono (meth) acrylates of polyalkylene glycols (the number of alkylene glycol units is, for example, 2 to 23) such as polyethylene glycol and polypropylene glycol;

(C) Unsaturation containing hydroxyl group such as N-hydroxymethyl (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide and N, N-bis (2-hydroxyethyl) (meth) acrylamide Amides, (d) o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, o-hydroxy-α-methylstyrene, m-hydroxy-α-methylstyrene, p-hydroxy-α-methylstyrene and p-hydroxystyrene Examples include hydroxyl group-containing vinyl aromatic compounds such as vinylbenzyl alcohol, and (e) (meth) allyl alcohol. Of these, hydroxyalkyl (meth) acrylates and hydroxyl group-containing vinyl aromatic compounds are preferred. One of these monomers having a hydroxyl group may be used alone, two or more of them may be used in combination, or different types may be used in combination.

The monomers having an epoxy group include (meth) allyl glycidyl ether, glycidyl (meth) acrylate and 3,4-oxycyclohexyl (meth)
Acrylate and the like. One of these monomers having an epoxy group may be used alone, or two or more thereof may be used in combination.

Examples of the monomer having a carboxylic acid group include:
(A) unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, tetraconic acid and cinnamic acid, non-polymerizable polycarboxylic acids such as phthalic acid, succinic acid and adipic acid; (Meth) allyl alcohol and 2-
(B) Free carboxyl group-containing esters such as monoesters with a hydroxyl group-containing unsaturated compound such as hydroxyethyl (meth) acrylate, and salts thereof. Of these, unsaturated carboxylic acids are preferred.
In addition, these monomers having a carboxylic acid group may be used alone or in combination of two or more, and different types may be used in combination.

These monomers can be arbitrarily selected and used. Further, two or more kinds can be used in combination as described above. For example, a monomer having an amino group and a monomer having a hydroxyl group can be combined and used as a monomer. Further, in the repeating unit in the crosslinked rubber particle component, the content of the unit composed of a monomer is 0.1 to 30% by mass, particularly 0.3% by mass.
It is preferably from 15 to 15% by mass. If the content of the monomer unit is less than 0.1% by mass, the affinity between the crosslinked rubber particles and silica becomes insufficient, and the processability of the rubber composition may not be sufficiently improved. On the other hand, when this content exceeds 30% by mass, the crosslinked rubber particles and silica are aggregated, and the processability tends to decrease.

Further, in the formation of the repeating unit (2) in the crosslinked rubber particle component, if necessary, a monomer (hereinafter, referred to as "monomer") and an acrylate which form an aromatic vinyl unit. At least one of the monomers forming the unit may be used in combination. In the formation of the repeating unit (3), a monomer forming an aromatic vinyl unit may be used in combination, if necessary. In the formation of the repeating unit (1), no monomer is used in combination.

As the monomers, styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene,
α-methylstyrene, 2,4-dimethylstyrene, 2,
4-diisopropylstyrene, 4-tert-butylstyrene, tert-butoxystyrene and the like. Further, as the monomer for forming the acrylate unit, the same monomer as described above can be used. One of these monomers may be used alone, two or more of them may be used in combination, or different types may be used in combination.

In forming the crosslinked rubber particle component, another compound having one copolymerizable unsaturated group may be further used in combination. Examples of such a compound include vinylidene cyanide, vinyl chloride, vinylidene chloride, (meth) acrylamide, and maleimide. One of these monomers may be used alone, or two or more thereof may be used in combination. When these monomers are used, when the total amount of the other monomers is 100 parts by mass (hereinafter abbreviated as “parts”), 0.1 to 50 parts, especially 0.5 part
To 30 parts.

The crosslinked rubber particles can be produced by emulsion polymerization or suspension polymerization using a radical polymerization initiator, but are preferably produced by emulsion polymerization from the viewpoint of uniformity of particle size and particle diameter.

As the radical polymerization initiator, benzoyl peroxide, lauroyl peroxide, tert
-Butyl hydroperoxide, cumene hydroperoxide, paramenthane hydroperoxide, di-te
Organic peroxides such as rt-butyl peroxide and dicumyl peroxide can be used. Also, an azo compound represented by azobisisobutyronitrile, an inorganic peroxide represented by potassium persulfate, and a redox catalyst represented by a combination of these peroxides and ferrous sulfate are used. You can also. One of these radical polymerization initiators may be used alone, two or more of them may be used in combination, or different types may be used in combination. Also, ter
mercaptans such as t-dodecyl mercaptan, n-dodecyl mercaptan, carbon tetrachloride, thioglycols,
Chain transfer agents such as diterpenes, terpinolene and γ-terpinenes can also be used in combination.

The emulsifier used in the emulsion polymerization includes an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant and the like. Further, a fluorine-based surfactant can also be used. These emulsifiers may be used alone, or two or more of them may be used in combination, or different types may be used in combination.

As the suspension stabilizer used in the suspension polymerization, polyvinyl alcohol, sodium polyacrylate, hydroxyethyl cellulose and the like can be mentioned.
One of these suspension stabilizers may be used alone, or two or more thereof may be used in combination.

In emulsion polymerization or suspension polymerization, each monomer and radical polymerization initiator may be charged in their entirety into a reaction vessel to start polymerization, or may be continuously or intermittently continued during the reaction. May be added. The polymerization can be carried out at 0 to 80 ° C. using a reactor from which oxygen has been removed, and operating conditions such as temperature and stirring can be appropriately changed during the reaction. The polymerization system may be a continuous system or a batch system.

The above “non-crosslinked rubber component” includes the following (a)
Or at least one of the polymers (e). (A) a polymer in which the repeating unit consists solely of a conjugated diene unit (formed of a monomer); (b) a conjugated diene unit and an aromatic vinyl unit (formed of a monomer) as the repeating unit (C) as a repeating unit, a conjugated diene unit and α, β-
A polymer having an unsaturated nitrile unit (formed of a monomer); and (c) optionally containing an acrylate unit (formed of a monomer) and an aromatic vinyl unit. Is also good. (D) Acrylic rubber, usually containing 50% by mass or more of acrylate. This (d) contains a monomer unit (formed by a monomer) having two or more polymerizable carbon-carbon double bonds in the molecule in order to introduce an unsaturated group. You may. (E) as a repeating unit, a polymer having an ethylene unit (formed of only ethylene) and an α-olefin unit having a prime number of 3 to 12 (formed of a monomer);
This (e) may optionally contain a non-conjugated polyene unit (formed by a monomer).

A monomer (monomer) forming a conjugated diene unit constituting the non-crosslinked rubber component (a) to (d), and a monomer forming an aromatic vinyl unit constituting the non-crosslinked rubber component (b) Monomer (monomer), monomer (monomer) forming α, β-unsaturated nitrile unit constituting non-crosslinked rubber component (c), and non-crosslinked rubber component (c), (d) The monomers (monomers) forming the acrylate units constituting the above are the monomers used for forming the crosslinked rubber particle components, respectively.
The same monomers as described above can be used.

In the acrylic rubber of the non-crosslinked rubber component (d), the number of carbon atoms of a monomer having two or more polymerizable carbon-carbon double bonds in a molecule used for introducing an unsaturated group is as follows: It is preferably from 5 to 25. As monomers, vinyl methacrylate, vinyl acrylate,
Allyl methacrylate, dicyclopentenyloxyethyl acrylate, 1,1-dimethylpropenyl methacrylate, 1,1-dimethylpropenyl acrylate,
1,1-dimethyl-3-butenyl methacrylate, 1,
1-dimethyl-3-butenyl acrylate, divinyl itaconate, divinyl maleate, vinyl 1,1-dimethylpropenyl ether, vinyl 1,1-dimethyl-3-
Butenyl ether, 1-acryloyl-1-phenylethene and the like. Among these, vinyl methacrylate, allyl methacrylate and dicyclopentenyloxyethyl acrylate are particularly preferred. One of these monomers may be used alone, or two or more thereof may be used in combination.

The monomer forming the ethylene unit in the non-crosslinked rubber component (e) is ethylene. In addition, propylene, 1-butene, 1-pentene, 1
-Hexene, 4-methyl-1-pentene, 1-heptene, 5-methyl-1-hexene, 1-octene, 1-nonene, 5-ethyl-1-hexene, 1-decene, 3-methyl-1-butene And the like. One of these
-Hexene and 1-octene are particularly preferred. One of these monomers may be used alone, or two or more thereof may be used in combination.

As the monomer, a commonly used non-conjugated diene can be used without any particular limitation. For convenience, the polymer is divided into two types depending on whether or not a branched chain is formed in the produced polymer. Can be. Examples of the non-conjugated diene having a branched chain formed in the polymer include dicyclopentadiene, 2,5-norbornadiene, 5-vinyl-2-norbornene, and aliphatic α, ω-diene having 6 to 20 carbon atoms. No. As the aliphatic α, ω-diene,
1,5-hexadiene, 1,6-heptadiene, 1,7
-Octadiene, 1,8-nonadiene, 1,9-decadiene and the like.

Non-conjugated dienes having no branched chain formed in the polymer include 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropenyl-2-norbornene, 5- (1-butenyl). ) -2-
Norbornene, cyclooctadiene, vinylcyclohexene, 1,5,9-cyclododecatriene, 6-methyl-4,7,8,9-tetrahydroindene, 2,2′-
Dicyclopentenyl, trans-1,2-divinylcyclobutane, 2-methyl-1,4-hexadiene, 1,6
-Octadiene, 1,4-hexadiene, 7-methyl-
1,6-octadiene, 5,7-dimethyl-1,6-octadiene, 3,7-dimethyl-1,6-octadiene, 1,4,7-octatriene, dicyclooctadiene, methylene norbornene, and the like. Can be.

Among these non-conjugated polyenes, those having a branched chain formed in the polymer are preferably 1,9-decadiene and dicyclopentadiene. Examples in which no branched chain is formed include 5-ethylidene-2-norbornene, 1,4-hexadiene, 7-methyl-1,6.
-Octadienes and 5,7-dimethyl-1,6-octadienes are preferred. Each of these non-conjugated polyenes has 1
Although only one kind may be used or two or more kinds may be used in combination, it is more preferable to use at least one kind each having a polymer having a branched chain and one not having a branched chain.

The non-crosslinked rubber component selected from (a) to (e) includes the following. (A) a polymer in which the repeating unit is composed of only a conjugated diene unit; an emulsion-polymerized polybutadiene rubber, a Ziegler-based catalyst mainly containing a transition metal compound such as Ti, Ni, Co, and an organic aluminum compound, or a Nd compound and an organic aluminum High-ci prepared by a catalyst comprising a compound
s-polybutadiene rubber, high-trans-polybutadiene rubber prepared by a catalyst comprising a Ba compound and an organomagnesium compound, an organoaluminum compound,
Emulsion polymerized polyisoprene rubber, high-cis-polyisoprene rubber, butadiene / isoprene copolymer rubber, natural rubber, chloroprene rubber, etc.

(B) Polymer having a conjugated diene unit and an aromatic vinyl unit as a repeating unit; styrene / butadiene random copolymer rubber, styrene / butadiene block copolymer rubber, styrene / isoprene random copolymer rubber, styrene / styrene copolymer Isoprene / butadiene random copolymer rubber, styrene / butadiene / styrene triblock copolymer rubber, styrene / isoprene / styrene triblock copolymer rubber, etc.

(C) A polymer having a conjugated diene unit and an α, β-unsaturated nitrile unit as essential units and optionally having an aromatic vinyl unit and an acrylate unit; acrylonitrile-butadiene copolymer rubber; (D) acrylic rubber, such as acrylonitrile / isoprene copolymer rubber, acrylonitrile / styrene / butadiene copolymer rubber, acrylonitrile / styrene / isoprene copolymer rubber

(E) As a repeating unit, an ethylene unit and an α-olefin unit having 3 to 12 carbon atoms are essential,
If necessary, a polymer having a non-conjugated polyene unit; ethylene / propylene copolymer rubber, ethylene / 1-butene copolymer rubber, ethylene / 1-pentene copolymer rubber, ethylene / 1-hexene copolymer rubber, ethylene / 1 -An octene copolymer rubber or the like, or an ethylene / propylene / diene copolymer rubber such as ethylene / propylene / 5-ethylidene-2-norbornene having a monomer unit forming a non-conjugated polyene unit.

The non-crosslinked rubber component may have at least one functional group selected from an amino group, a hydroxyl group, an epoxy group, a carboxylic acid group and an alkoxysilyl group. As a monomer for introducing an amino group, a hydroxyl group, an epoxy group, and a carboxylic acid group, the same monomers as in the case of the crosslinked rubber particle component can be used.

Examples of the monomer having an alkoxysilyl group include (meth) acryloxymethyltrimethoxysilane,
(Meth) acryloxymethylmethyldimethoxysilane,
(Meth) acryloxymethyldimethylmethoxysilane,
(Meth) acryloxymethyltriethoxysilane, (meth) acryloxymethylmethyldiethoxysilane, (meth) acryloxymethyldimethylethoxysilane, (meth) acryloxymethyltripropoxysilane, (meth) acryloxymethylmethyldipropoxy Silane,
(Meth) acryloxymethyldimethylpropoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyldimethylmethoxysilane, γ- (meth) ) Acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropyldimethylethoxysilane, γ- (meth) acryloxypropyltripropoxysilane, γ- (meth) Acryloxypropylmethyldipropoxysilane, γ-
(Meth) acryloxypropyldimethylpropoxysilane, γ- (meth) acryloxypropylmethyldiphenoxysilane, γ- (meth) acryloxypropyldimethylphenoxysilane, γ- (meth) acryloxypropylmethyldibenzyloxysilane and γ -(Meth) acryloxypropyldimethylphenoxysilane and the like.

As the monomer having an amino group, a hydroxyl group, an epoxy group, a carboxylic acid group and an alkoxysilyl group, only one of each type may be used.
More than one kind can be used together, and different kinds can be used together. Incidentally, the affinity between silica and the non-crosslinked rubber component can be enhanced by the combined use of the alkoxysilyl group.

The non-crosslinked rubber component is used to convert each of the monomers constituting them into monomers to be used such as emulsion polymerization, suspension polymerization, solution radical polymerization, solution anion polymerization, and solution transition metal catalyzed polymerization. It can be manufactured by an appropriate method. The non-crosslinked rubber component into which the functional group has been introduced can be produced by using a monomer used for forming a crosslinked rubber particle component or the above alkoxysilyl group in combination. The polymerization method is not particularly limited, but is preferably produced by emulsion polymerization or suspension polymerization.

The non-crosslinked rubber component has a toluene insoluble content of "20% by mass or less" calculated from the solid content in the filtrate obtained by immersing in 100 ml of toluene at room temperature for 24 hours and then filtering through a 100 mesh wire mesh. , 15% by mass or less, more preferably 10% by mass or less. Further, the weight average molecular weight in terms of polystyrene determined by GPC (gel permeation chromatography) is preferably 50,000 to 2,000,000.

The rubber composition of the present invention contains 1 to 7 parts based on 100 parts of the total rubber component contained in the rubber composition.
It is preferable to contain 0 parts of the crosslinked rubber particle component and 30 to 99 parts of the non-crosslinked rubber component. If the crosslinked rubber particle component is less than 1 part, the effect of improving processability is small, and if it exceeds 70 parts, the physical properties of the vulcanized rubber are undesirably reduced.

The rubber composition of the present invention may further contain a mineral oil-based softener. Those containing this mineral oil-based softener are generally referred to as oil-added crosslinked rubber components. Examples of the mineral oil-based softener include aromatic oil, naphthenic oil, and paraffin oil. One of these may be used, or a mixture of two or more thereof may be used. The content of the mineral oil-based softener is 10 to 80 parts, preferably 10 to 60 parts, when the total of the crosslinked rubber particle component and the non-crosslinked rubber component is 100 parts,
More preferably, it can be 10 to 50 parts. This mineral oil-based softener may be blended with the above-mentioned crosslinked rubber particle component or with the above-mentioned non-crosslinked rubber component.

When the rubber composition of the present invention is put to practical use, usually a reinforcing agent is blended. The reinforcing agent is not particularly limited, but silica and / or carbon black is preferably used. As this silica,
What is generally used as a bright-color reinforcing compound for synthetic rubber can be used. The type of silica is not particularly limited, but may be wet-process white carbon, dry-process white carbon, colloidal silica, and JP-A-62-62.
No. 838, precipitated silica and the like.
Of these, wet-process white carbon containing hydrous silicic acid as a main component is particularly preferred. Each of these silicas may be used alone or in combination of two or more. The specific surface area of this silica is not particularly limited,
Usually 50 to 400 m ^{2 in} nitrogen adsorption specific surface area (value measured by BET method according to ASTM D3037-81)
/ G, especially 50-220 m ² / g, even 70-220
When m ² / g, the desired reinforcing effect is sufficiently obtained, and the wear resistance and heat generation of the vulcanized rubber are sufficiently improved.

When the above-mentioned silica is used alone, its content is 2 to 120 parts, particularly 10 parts, when the total content of the crosslinked rubber particle component and the non-crosslinked rubber component is 100 parts.
It is preferable to set it to 100 parts. If the content of the silica is less than 2 parts, a sufficient reinforcing effect cannot be obtained, which is not preferable. On the other hand, if the content is 120 parts, a sufficient reinforcing effect can be obtained, and it is not necessary to contain more than this amount.

The type of the carbon black is not particularly limited, but furnace black, acetylene black, thermal black, channel black, graphite and the like can be used. Among these, furnace black is particularly preferred, and specific examples thereof include:
SAF, ISAF, ISAF-HS, ISAF-LS,
IISAF-HS, HAF, HAF-HS, HAF-L
S, FEF and the like. One type of these carbon blacks may be used alone, or two or more types may be used in combination.

The nitrogen adsorption specific surface area of carbon black measured in the same manner as in the case of silica is preferably 5 to 200.
m ² / g, more preferably 50 to 150 m ² / g,
More preferably, it is 80 to 130 m ² / g. Within this range, the tensile strength, wear resistance, etc. of the vulcanized rubber will be sufficiently improved. The DBP adsorption amount of carbon black is not particularly limited, but is preferably 5 to 300 ml / 100.
g, more preferably 50 to 200 ml / 100 g, particularly preferably 80 to 160 ml / 100 g, since the tensile strength, wear resistance and the like are sufficiently improved. Further, as carbon black, JP-A-5-230290
Cetyltrimethylammonium bromide described in Japanese Patent Application Laid-Open Publication No. H10-21087 has an adsorption specific surface area of 110 to 170 m ² / g, and D after repeatedly compressed four times at a pressure of 165 MPa.
BP (24M4DBP) oil absorption is 110-130ml /
By using 100 g of the high-structure carbon black, the abrasion resistance can be further improved.

As a reinforcing agent, silica and carbon black can be used in combination. In this case, the content
Total 1 of the content of the crosslinked rubber particle component and the non-crosslinked rubber component
The amount is preferably 10 to 120 parts, particularly preferably 40 to 100 parts with respect to 00 parts. If the total amount is less than 10 parts, a sufficient reinforcing effect cannot be obtained, which is not preferable. Meanwhile, 1
If it is 20 parts, a sufficient reinforcing effect can be obtained, and it is not necessary to contain more than this. Further, the amount ratio of silica to carbon black is not particularly limited.
0 parts, carbon black is 5 to 200 parts,
In particular, it is preferably 10 to 150 parts. When the amount ratio is within this range, a vulcanized rubber having more excellent tensile strength and wear resistance can be obtained. Further, a carbon-silica dual phase filler or the like can be used as a reinforcing agent.

The rubber composition of the present invention may contain the following various components in addition to the above-mentioned reinforcing agent. As a filler, talc, clay, calcium carbonate, magnesium carbonate and the like can be added in an appropriate amount. In addition, petroleum-based blended oils such as aromatic process oils, naphthene-based process oils, and paraffin-based process oils can be blended as extender oils. As the extender oil, aromatic and naphthenic process oils are preferred. Further, when silica is used as a reinforcing agent, the balance between processability and reinforcing property can be further improved by using a silane coupling agent in combination. The compounding amount of the silane coupling agent is preferably less than 20 parts, particularly less than 12 parts with respect to 100 parts of silica. Also, as an activator, diethylene glycol, polyethylene glycol,
Silicone oil, triethanolamine, tri-is
o-Propanolamine and the like can also be used. In addition, an appropriate amount of an antioxidant, a processing aid, or the like can be added.

Examples of the crosslinking agent include sulfur such as powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur and highly dispersible sulfur, sulfur halides such as sulfur monochloride and sulfur dichloride, dicumyl peroxide, and di-sulfur. Organic peroxides such as t-butyl peroxide, quinone dioximes such as p-quinone dioxime, p, p'-dibenzoylquinone dioxime, triethylenetetramine, hexamethylenediaminecarbamate, 4,4'-methylenebis- Examples thereof include organic polyamine compounds such as o-chloroaniline, and alkylphenol resins having a methylol group. Of these, sulfur is preferred, and powdered sulfur is particularly preferred. These cross-linking agents may be used alone, or two or more of them may be used in combination, or different types may be used in combination.

This crosslinking agent is usually used when the total amount of the crosslinked rubber particle component and the non-crosslinked rubber component is 100 parts.
The amount can be 0.1 to 15 parts, preferably 0.3 to 10 parts, particularly preferably 0.5 to 5 parts. When a crosslinking agent having a ratio in this range is blended, the tensile strength, abrasion resistance and the like are sufficiently improved.

Examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazolesulfenamide, Nt-butyl-2-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, -Sulfenamide-based vulcanization accelerators such as -oxyethylene-2-benzothiazolesulfenamide, N, N'-diisopropyl-2-benzothiazolesulfenamide, diphenylguanidine, dioltotolylguanidine, orthotolylbiguanidine and the like Guanidine vulcanization accelerators, thiocarbanilides, thiouretylthiourea, ethylenethiourea, diethylthiourea, thiourea vulcanization accelerators such as trimethylthiourea,

2-mercaptobenzothiazole, dibenzothiazyldisulfide, 2-mercaptobenzothiazole zinc salt, 2-mercaptobenzothiazole sodium salt, 2-mercaptobenzothiazolecyclohexylamine salt, 2- (2,4-dinitrophenylthio) Thiazole-based vulcanization accelerators such as benzothiazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, thiuram-based vulcanization accelerators such as dipentamethylenethiuram tetrasulfide,

Sodium dimethyldithiocarbamate,
Sodium diethyldithiocarbamate, sodium di-n-butyldithiocarbamate, lead dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc pentamethylenedithiocarbamate, zinc ethylphenyldithiocarbamate, Acceleration of dithiocarbamic acid-based vulcanization such as tellurium diethyldithiocarbamate, selenium dimethyldithiocarbamate, selenium diethyldithiocarbamate, copper dimethyldithiocarbamate, iron dimethyldithiocarbamate, diethylamine diethyldithiocarbamate, piperidine pentamethylenedithiocarbamate, and pipecoline methylpentamethylenedithiocarbamate. Agent, sodium isopropyl xanthate, isop Pirukisantogen zinc, butyl xanthate zinc xanthate-based vulcanization accelerators such as and the like.

One of these vulcanization accelerators may be used alone, two or more of them may be used in combination, or different types may be used in combination. It is particularly preferable to use at least a sulfenamide-based vulcanization accelerator as the vulcanization accelerator. The compounding amount of the vulcanization accelerator is 0.1 to 15 parts, especially 0.3 parts, when the total amount of the crosslinked rubber particle component and the non-crosslinked rubber component is 100 parts.
It is preferably from 10 to 10 parts, more preferably from 1 to 10 parts.

As a vulcanization activator, higher fatty acids such as stearic acid and zinc oxide can be used. As zinc oxide, those having a high surface activity and a particle size of 5 μm or less are preferable. As such zinc oxide, activated zinc white having a particle size of 0.05 to 0.2 μm or 0.3 to 1 μm
m and zinc white. Further, zinc oxide or the like surface-treated with an amine-based dispersant or wetting agent can also be used.

These vulcanization activators may be used alone or in combination of two or more, and different types may be used in combination. The vulcanization activator can have an appropriate blending amount depending on the type thereof. When a higher fatty acid is used, the total amount of the crosslinked rubber particles and the non-crosslinked rubber component is 100 parts by weight.
It is preferably 15 parts, particularly 0.1 to 10 parts, and more preferably 0.5 to 5 parts. When using zinc oxide,
0.05 to 10 parts, especially 0.1 to 7 parts, furthermore 0.5 to
Preferably it is 5 parts. A compounding amount in this range is particularly preferable because the processability of the rubber composition and the tensile strength and abrasion resistance of the vulcanized rubber are improved in a very well-balanced manner.

The rubber composition of the present invention and a rubber product using the same can be produced as follows. First, reinforcing agents such as cross-linked rubber particles, non-cross-linked rubber components, silica, carbon black, carbon-silica dual phase filler, extending oil, and other compounding agents are mixed using a kneader such as a Banbury mixer. Knead at a temperature of ~ 180 ° C. Thereafter, the kneaded material is cooled, and a vulcanizing agent such as sulfur, a vulcanization accelerator and the like are further compounded using a Banbury mixer or a mixing roll, and molded into a predetermined shape. Next, vulcanization is performed at a temperature of 140 to 180 ° C. to obtain a required vulcanized rubber, that is, a rubber product.

Further, this vulcanized rubber can be used as a rubber product in various fields due to its excellent properties. For example, rubber roll, milling roll, belt,
Industrial products such as hoses, sponges, rubber plates, rubberized cloth,
It can be used as footwear such as transparent shoes, general colored shoes, and sponge soles, large vehicles such as treads, base treads, sidewalls, and rubber chafers, general vehicle tires, sanitary skins, and sanitary materials such as medical supplies. .

[0071]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail by way of examples. (1) Production of Crosslinked Rubber Particle Components A polymerization vessel was charged with 200 parts of water, 4.5 parts of a rosin acid soap, and a monomer having the composition shown in Table 1 (the unit in Table 1 is "parts"). . Thereafter, the temperature of the polymerization vessel was set at 5 ° C., and 0.1 part of p-menthane hydroperoxide, 0.07 part of sodium ethylenediaminetetraacetate, 0.05 part of ferrous sulfate heptahydrate were used as radical polymerization initiators. Department,
And sodium formaldehyde sulfoxylate 0.
15 parts were added and polymerized for 12 hours to obtain an emulsion containing crosslinked rubber particles. The polymerization conversion was about 100%. Next, if necessary, this emulsion is mixed with an aromatic oil in an amount of 37.5 parts based on 100 parts of the crosslinked rubber particles, and this is coagulated with sulfuric acid and a salt to form a crumb, and then dried with hot air. Drying was carried out by a machine to obtain crosslinked rubber particle components 1 to 8 having the monomer compositions shown in Table 1. In Table 1, the crosslinked rubber particle component No. 5 is an oil-extended type containing an aromatic oil (see Table 6), and the other is a non-oil-extended type not containing an aromatic oil.

[0072]

[Table 1]

(2) Production of Non-Crosslinked Rubber Component In a polymerization vessel, 200 parts of water, 4.5 parts of rosin acid soap, and a monomer having the composition shown in Table 2 (units in Table 2 are "parts"). Was charged. Thereafter, the temperature of the polymerization vessel was set at 5 ° C., and 0.1 part of p-menthane hydroperoxide, 0.07 part of sodium ethylenediaminetetraacetate, 0.05 part of ferrous sulfate heptahydrate were used as radical polymerization initiators. Department,
And sodium formaldehyde sulfoxylate 0.
The polymerization was started by adding 15 parts. 60% polymerization conversion
When the reaction reached, the reaction was terminated by adding diethylhydroxylamine, and then the unreacted monomer was recovered by steam stripping to obtain an emulsion containing a non-crosslinked rubber component. Next, if necessary, this emulsion is mixed with an aromatic oil so that the amount becomes 37.5 parts with respect to 100 parts of the non-crosslinked rubber component, and the resulting mixture is coagulated with sulfuric acid and a salt to form a crumb. Non-crosslinked rubber component 1 consisting of the monomer composition shown in Table 2 after drying with a hot air drier
~ 8. In addition, the non-crosslinked rubber particle component No. 7 and 8 are oil-extended types containing an aromatic oil (see Table 6), and others are non-oil-extended types without an aromatic oil.

As the non-crosslinked rubber component, the following three types of non-crosslinked rubber were also used. (A) Solution-polymerized styrene / butadiene copolymer rubber, manufactured by JSR Corporation, trade name "JSR SL57
4 ", amount of bound styrene; 15% by mass, amount of 1,2-vinyl bond; 57%, amount of 1,4-trans bond; 27%, 1,
4-cis bond amount: 16% (b) Polybutadiene rubber, manufactured by JSR Corporation, trade name "JSR BR01" (c) Ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber, manufactured by JSR Corporation ,
Trade name "JSR EP33", ethylene content; 52% by mass, 5-ethylidene-2-norbornene content; 8.1% by mass

[0075]

[Table 2]

The binding amount of each monomer in Table 2 was measured by the following method. (A) Amount of bound styrene (% by mass); determined by preparing a calibration curve by infrared absorption spectroscopy. (B) Amount of bound acrylonitrile (% by mass): The rubber was dissolved in toluene and reprecipitated with methanol twice to purify, purified, vacuum dried, subjected to elemental analysis, and calculated from the nitrogen content. . (C) Amount of bound acrylate (% by mass); determined from ¹³ C-nuclear magnetic resonance spectrum. (D) Amino group-containing monomer binding amount (% by mass): Purification by twice dissolving the rubber in toluene and reprecipitating with methanol, followed by vacuum drying and elemental analysis,
It was calculated from the nitrogen content.

(E) Amount of hydroxyl-containing monomer bound (% by mass): The rubber was dissolved in toluene and reprecipitated with methanol twice, purified, dried in vacuo, and dried.
It was measured by 0 MHz ¹ H-NMR. (F) Epoxy group-containing monomer binding amount (% by mass): The operation of dissolving the rubber in toluene and reprecipitating with methanol is described in 2
After performing purification twice and drying under vacuum, the Jay method [R. R.
Jay; Anal. Chem. , 36, 667 (196)
4)] and determined by titration.

(G) Carboxylic acid group-containing monomer binding amount (% by mass): The rubber was dissolved in toluene and reprecipitated with methanol twice to purify the product, followed by vacuum drying. It was dissolved in chloroform and determined by neutralization titration. (H) Alkoxysilyl group-containing monomer binding amount (% by mass): The rubber was dissolved in toluene and reprecipitated with methanol twice to purify the product, dried in vacuum, and dried.
Measured in MHz ¹ H-NMR. Table 2 shows the results of the measurements.

(4) Preparation of Rubber Composition and Vulcanized Rubber Using the crosslinked rubber particle component shown in Table 1 and the non-crosslinked rubber component shown in Table 2, the compounding formulas shown in Tables 3 to 7 were used in the formulation of Labo Plastomill (Toyo Seiki Co., Ltd.). (Manufactured by the company) to obtain rubber compositions of Examples 1 to 20 shown in Tables 3 to 7. Then, it was vulcanized at 160 ° C. for 20 minutes by a vulcanizing press to obtain a vulcanized rubber. Also,
The rubber compositions of Comparative Examples 1 to 7 shown in Tables 5 to 7 were similarly obtained using only the non-crosslinked rubber component without using the crosslinked rubber particle component, and vulcanized in the same manner.

[0080]

[Table 3]

[0081]

[Table 4]

[0082]

[Table 5]

[0083]

[Table 6]

[0084]

[Table 7]

The following ingredients were used in the above formulation. Silica; manufactured by Nippon Silica Industry Co., Ltd., trade name "Nipsil VN3" Carbon black; manufactured by Mitsubishi Chemical Corporation, trade name "Diablack N220" Silane coupling agent; manufactured by GE Toshiba Silicone Co., trade name, "TSL8380" Anti-aging Agent: manufactured by Ouchi Shinko Chemical Co., Ltd., trade name "Nocrack 810NA" Vulcanization accelerator; (a) manufactured by Ouchi Shinko Chemical Co., Ltd.
Product name “Noxeller CZ”, (b) manufactured by Ouchi Shinko Chemical Co., Ltd., product name “Noxeller D”

The physical properties of the rubber composition and the vulcanized rubber were evaluated by the following methods. (A) Processability: Evaluated by the wrapping property around the roll when the rubber composition was kneaded with the roll. The evaluation criteria are as follows. A: Excellent without floating from the roll surface. ；: Slightly rising and good. Δ: winding, but easy to float and inferior. ×: hardly wrapped, very poor

(B) Shrinkage of unvulcanized rubber sheet: The degree of shrinkage of the unvulcanized rubber sheet after kneading the rubber composition with a roll, and the surface condition were visually observed. The evaluation criteria are as follows. A: The shrinkage is extremely small, the surface of the unvulcanized rubber sheet is smooth and glossy, and it is excellent. ；: Shrinkage is small, the surface of the unvulcanized rubber sheet is smooth and good. Δ: Shrinkage was observed and inferior. X: The shrinkage was extremely large, and the unvulcanized rubber sheet was cut off and very poor.

(C) Tensile properties: Elongation at break EB (%) and tensile strength TB using a No. 3 type test piece at a measurement temperature of 25 ° C. and a tensile speed of 500 mm / min in accordance with JIS K 6301 (MPa) was measured. (D) Abrasion resistance: Measured using an Akron abrasion tester according to JIS K 6264. The evaluation result is represented by an integer ranging from severe wear (0 point) to extremely low wear (5 points). The results of the evaluation are also shown in Tables 3 to 7.

According to Tables 3 to 7, the rubber compositions of Examples 1 to 20 are excellent in processability and dimensional stability, the vulcanized rubber has sufficiently high elongation and tensile strength, and has abrasion resistance of 4 or 4. 5 is good. On the other hand, in Comparative Examples 1 to 7 in which no crosslinked rubber particle component was used, workability and dimensional stability, particularly, dimensional stability was reduced, abrasion resistance was inferior to 3 or 2, and tensile strength was not sufficient. It turns out that there are cases.

[0090]

According to the rubber composition of the present invention, the rubber obtained by using the rubber composition has good processability and furthermore has excellent dimensional stability. In particular, excellent properties are exhibited by containing silica as a reinforcing material. In addition, a vulcanized rubber excellent in tensile strength, abrasion resistance and the like can be obtained.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 91/00 C08K 5/54 (72) Inventor Yoshiyuki Udagawa 2-11-24 Tsukiji, Chuo-ku, Tokyo JSR Corporation (72) Inventor Hiroshi Akima 11-11-24 Tsukiji, Chuo-ku, Tokyo FSR term (reference) 4J002 AC021 AC032 AC061 AC062 AC071 AC082 AC091 AC092 AC101 AC111 AE053 BG042 DA036 DE236 DJ016 DJ036 DJ046 EX007FD016 FD140 FD150

Claims (9)

[Claims] [1] A crosslinked rubber particle component having a toluene-insoluble content of 50% by mass or more and a number average particle diameter of 3 to 1000 nm, and [2] a non-crosslinked rubber having a toluene-insoluble content of less than 20% by mass. A crosslinked rubber particle component comprising: (1) a repeating unit comprising:
A polymer comprising a conjugated diene unit and a monomer unit having at least two polymerizable unsaturated groups, (2) a conjugated diene unit, an α, β-unsaturated nitrile unit and at least 2 And a monomer unit having a polymerizable unsaturated group, and (3) as a repeating unit,
A conjugated diene unit, an acrylate unit and at least 2
A polymer comprising at least one monomer unit having a polymerizable unsaturated group, wherein the non-crosslinked rubber component is (a) a polymer wherein the repeating unit comprises only a conjugated diene unit, (B) a polymer having a conjugated diene unit and an aromatic vinyl unit as a repeating unit, and (c) a conjugated diene unit and α,
at least one of a polymer having a β-unsaturated nitrile unit, (d) an acrylic rubber, and (e) a polymer having, as a repeating unit, an ethylene unit and an α-olefin unit having 3 to 12 carbon atoms. A rubber composition, characterized in that: 2. The conjugated diene forming each of the conjugated diene units constituting the crosslinked rubber particle component and the conjugated diene forming each of the conjugated diene units constituting the non-crosslinked rubber component are 1,3-butadiene. , 2,3-dimethyl-
The aromatic vinyl which is at least one of 1,3-butadiene, isoprene and chloroprene and forms the aromatic vinyl unit constituting the non-crosslinked rubber component is styrene, 2-methylstyrene, or 3-methylstyrene. , 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-tert-butylstyrene and tert-butoxystyrene
And a monomer that forms a monomer unit having at least two polymerizable unsaturated groups that constitutes the crosslinked rubber particle component is ethylene glycol di (meth) acrylate, propylene glycol di (meth). Acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri ( At least one of meth) acrylate, pentaerythritol tetra (meth) acrylate, divinylbenzene, diisopropenylbenzene and trivinylbenzene, wherein the α, β-unsaturated nitrile unit constituting the crosslinked rubber particle component is Monomer to form, or the above non-crosslinked The alpha, beta-monomer to form an unsaturated nitrile units, acrylonitrile, methacrylonitrile and rubber composition according to claim 1 is at least one of these derivatives constituting the beam components. 3. At least a part of the crosslinked rubber particle component is composed of one polymerizable unsaturated group, an amino group, a hydroxyl group, an epoxy group and a carboxylic acid group (CO ₂ H and / or CO ₂ ) as a repeating unit. _3. The rubber composition according to claim 1, wherein the rubber composition contains 0.1 to 30% by mass of a monomer unit having at least one functional group of ( ₂ ) ^- ). 4. A method according to claim 1, wherein at least a part of the non-crosslinked rubber component has one polymerizable unsaturated group, an amino group, a hydroxyl group, an epoxy group, a carboxylic acid group (CO ₂ H and / or CO ₂ ) as a repeating unit. ₂ ^-) and alkoxy rubber composition according to any one of claims 1 to 3 monomer units containing 0.1 to 30 wt% and at least one functional group of the silyl group. 5. The rubber composition according to claim 1, further comprising a mineral oil softener. 6. The rubber composition according to claim 1, further comprising silica and / or carbon black. 7. When the silica is contained and the carbon black is not contained, the content of the silica is 2 to 100 parts by mass in total of the crosslinked rubber particle component and the non-crosslinked rubber component. The rubber composition according to claim 6, wherein the amount is 120 parts by mass. 8. When the silica and the carbon black are used in combination, the total content of the silica and the carbon black is based on 100 parts by mass of the total amount of the crosslinked rubber particle component and the non-crosslinked rubber component. The rubber composition according to claim 6, which is 10 to 120 parts by mass. 9. The rubber composition according to claim 6, further comprising a silane coupling agent.