JP2021161134A - Rubber composition and rubber molding - Google Patents

Abstract

To provide a rubber composition that has processability comparable to those of the conventional rubber compositions while allowing production of a crosslinked product having excellent strength and flexibility.SOLUTION: A rubber composition contains (A) ethylene-α-olefin-nonconjugated polyene copolymer rubber and (B) carbon black surface-treated with an organohydrogen polysiloxane compound.SELECTED DRAWING: None

Description

The present invention relates to a rubber composition and a rubber molded body, and more particularly to a rubber molded body composed of a rubber composition containing ethylene, an α-olefin, and a non-conjugated polyene copolymer rubber, and a crosslinked product thereof.

Since the ethylene / α-olefin / non-conjugated polyene copolymer does not have an unsaturated bond in the main chain, it is superior in weather resistance, heat resistance, and ozone resistance as compared with conjugated diene-based rubber.
The rubber composition containing ethylene / α-olefin / non-conjugated polyene copolymer rubber and its crosslinked material utilize the above-mentioned properties, and utilize the above-mentioned properties, and utilize the above-mentioned properties, and are used for automobile industrial parts, industrial rubber products, electrical insulating materials, civil engineering and building materials, rubberized materials. Widely used for rubber products such as cloth. Among them, since rubber products having excellent wear resistance are required for sealing parts used in a dynamic environment, it is widely known that carbon black is blended to enhance the reinforcing property (Patent Documents 1 and 2). Such).

Further, Patent Documents 3 and 4 disclose a technique for blending carbon black surface-treated with an alkoxysilane compound or the like into a rubber component.

Japanese Unexamined Patent Publication No. 2000-191863 Japanese Unexamined Patent Publication No. 2012-31342 Japanese Unexamined Patent Publication No. 10-30067 Japanese Unexamined Patent Publication No. 10-46047

However, in the conventional rubber composition containing carbon black, if the amount of reinforcing material such as carbon black is increased in order to increase the strength of the crosslinked product, the workability deteriorates (viscosity increases when unvulcanized). In some cases, the flexibility of the crosslinked product was reduced.

Therefore, an object of the present invention is to provide a rubber composition capable of producing a crosslinked product having excellent workability as that of a conventional product but having excellent strength and flexibility.

The present inventors have found that the above problems can be solved by blending carbon black with a specific surface treatment into a rubber composition, and have completed the present invention.
The gist of the present invention is as follows.

[1]
(A) Ethylene α- having a structural unit (a1) derived from ethylene, a structural unit (a2) derived from an α-olefin having 3 or more carbon atoms, and a structural unit (a3) derived from a non-conjugated polyene. A rubber composition containing carbon black surface-treated with an olefin / non-conjugated polyene copolymer rubber and (B) an organohydrogen polysiloxane compound.

[2]
The rubber composition of the above [1], wherein the non-conjugated polyene comprises at least one selected from the group consisting of 5-ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene (VNB).

[3]
The rubber composition according to the above [1] or [2], wherein the α-olefin contains propylene.
[4]
The rubber composition according to any one of [1] to [3], wherein the content of the surface-treated carbon black (B) is 1 to 400 parts by mass with respect to 100 parts by mass of the copolymer rubber (A). thing.

[5]
The rubber composition according to any one of the above [1] to [4], further containing a cross-linking agent.
[6]
A rubber molded product made of a crosslinked product of the rubber composition of the above [5].

The rubber composition according to the present invention can produce a crosslinked product having excellent strength and flexibility while having the same workability as a conventional product.

Hereinafter, the rubber composition and the like according to the present invention will be described in more detail.
[Rubber composition]
The rubber composition according to the present invention
(A) Ethylene α- having a structural unit derived from ethylene (a1), a structural unit derived from an α-olefin (a2) having 3 or more carbon atoms, and a structural unit derived from a non-conjugated polyene (a3). Carbon black surface-treated with an olefin / non-conjugated polyene copolymer rubber (hereinafter, also referred to as "copolymer rubber (A)") and (B) an organohydrogen polysiloxane compound (hereinafter, "surface-treated carbon black"). (B) ”.)
It is characterized by including.

<Copolymer rubber (A)>
The ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) is non-conjugated with a structural unit (a1) derived from ethylene and a structural unit (a2) derived from an α-olefin having 3 or more carbon atoms. It has a structural unit (a3) derived from polyene.

The α-olefin has 3 or more carbon atoms, preferably 3 to 20, and more preferably 3 to 8.
Examples of the α-olefin include propylene, 1-butene, 4-methylpentene-1,1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, and the like. Examples thereof include 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptene, 1-nonadecene, 1-eicosene, 9-methyldecene-1, 11-methyldodecene-1, and 12-ethyltetradecene-1. .. Among these, propylene, 1-butene, 4-methylpentene-1, 1-hexene and 1-octene are preferable, and propylene is particularly preferable.

These α-olefins may be used alone or in combination of two or more.
As an example of the non-conjugated polyene,
1,4-Hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4,5-dimethyl-1,4-hexadiene, 7- Chain non-conjugated diene such as methyl-1,6-octadiene, 8-methyl-4-ethylidene-1,7-nonadien and 4-ethylidene-1,7-undecadien;
Methyltetrahydroindene, 5-ethylidene-2-norbornene (ENB), 5-methylene-2-norbornene, 5-isopropyriden-2-norbornene, 5-viniliden-2-norbornene, 6-chloromethyl-5-isopropenyl- Cyclic non-conjugated diene such as 2-norbornene, 5-vinyl-2-norbornene (VNB), 5-isopropenyl-2-norbornene, 5-isobutenyl-2-norbornene, cyclopentadiene and norbornene;
2,3-Diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornene, 4-ethylidene-8-methyl-1,7-nonadien, etc. Trien is mentioned. Among these, 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene are preferable.

These non-conjugated polyenes may be used alone or in combination of two or more.
The molar ratio ((a1) / (a2)) of the structural unit (a1) derived from ethylene to the structural unit (a2) derived from α-olefin is preferably 50/50 to 95/5. It is preferably 60/40 to 80/20.

The proportion of the structural unit (a3) derived from the non-conjugated polyene in the copolymer rubber (A) is preferably 1.0 to 20.0% by mass, more preferably 3.0 to 15% by mass. More preferably, it is 4.0 to 14% by mass.

The ultimate viscosity [η] of the copolymer rubber (A) measured in decalin at 135 ° C. is usually 0.5 to 5.0 dL / g, preferably 0.5 to 4.0 dL / g. ..
Examples of the copolymer rubber (A) include ethylene / propylene / 5-ethylidene-2-norbornene random copolymer and ethylene / propylene / 5-ethylidene-2-norbornene / 5-vinyl-2-norbornene random. Copolymers can be mentioned.

The method for producing the copolymer rubber (A) is not particularly limited, and for example, the methods described in [0012] to [0018] of Patent Document 1 (Japanese Unexamined Patent Publication No. 2012-31342) can be adopted.

<Surface treatment carbon black (B)>
The surface-treated carbon black (B) is carbon black surface-treated with an organohydrogenpolysiloxane compound. Examples of the carbon black to be surface-treated include various carbon blacks such as SAF, ISAF, HAF, MAF, FEF, GPF, SRF, FT, and MT.

The average particle size of the surface-treated carbon black (B) and the surface-treated carbon black is preferably 20 to 50 μm, more preferably 20 to 40 μm, from the viewpoint of reinforcing properties and processability of the rubber composition.

Examples of the organohydrogenpolysiloxane compound include compounds represented by the following general formula (1).

In the formula (1), each of the plurality of Rs is independently a hydrocarbon group having 1 to 20 carbon atoms or a cyano group-containing group, preferably a hydrocarbon group having 1 to 15 carbon atoms, and more preferably. It is an alkyl group having 1 to 10 carbon atoms.

Examples of R include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, octyl group, cycloalkyl group, phenyl group, cyano group and vinyl group. , Allyl group is mentioned.

m is an integer of 1 to 50, preferably an integer of 2 to 30.
n is an integer of 1 to 50, preferably an integer of 2 to 30.
Examples of the compound represented by the general formula (1) include ethylhydrogenpolysiloxane, propylhydrogenpolysiloxane, and methylhydrogenpolysiloxane (compounds in which R is all a methyl group in the general formula (1)). preferable.

The surface treatment of carbon black with the organohydrogenpolysiloxane compound can be performed by a conventionally known method.
Examples of commercially available products of the surface-treated carbon black (B) include "SI01-4 DK" (manufactured by Daito Kasei Co., Ltd.).

The amount of the surface-treated carbon black (B) in the rubber composition according to the present invention is the copolymer rubber (A) 100 from the viewpoint of the balance between physical properties (strength and flexibility of crosslinked product) and roll processability. It is preferably 1 to 400 parts by mass, more preferably 10 to 150 parts by mass, and further preferably 50 to 100 parts by mass with respect to parts by mass.

Since carbon black usually has a carboxyl group, a hydroxyl group, or the like on its surface, when it is blended with EPDM, it has poor compatibility with EPDM, and agglutination between carbon blacks is observed. On the other hand, since the surface-treated carbon black (B) has a group represented by R in the above formula (1), it has high compatibility with EPDM, is well dispersed in the EPDM composition, and Since the Si—O bond of the organohydrogenpolysiloxane compound has a high bond energy, the rubber composition of the present invention containing the surface-treated carbon black (B) has the same processability as the conventional product (for example, (not yet). It is presumed that a crosslinked product having excellent strength and flexibility can be produced while having vulcanization) rubber composition (evaluated by Mooney viscosity).

<Reinforcing material>
The surface-treated carbon black (B) also functions as a reinforcing material for the copolymer rubber (A) in the rubber composition according to the present invention, but the rubber composition according to the present invention has the effect of the present invention. A reinforcing material other than the surface-treated carbon black (B) may be contained as long as it is not impaired.

Examples of such a reinforcing material include a reinforcing material generally used as a reinforcing material for synthetic rubber. Specific examples include silica, activated calcium carbonate, light calcium carbonate, heavy calcium carbonate, fine powder talc, fine powder silicic acid, talc and clay, and the surfaces thereof are treated with a silane coupling agent or the like, or surface-treated. Examples thereof include non-carbon black and surface-treated carbon black (excluding the surface-treated carbon black (B)).

These may be used alone or in combination of two or more.
When the reinforcing material is used, the amount of the reinforcing material in the rubber composition according to the present invention is the total amount of the reinforcing material and the surface-treated carbon black (B), and the copolymer rubber (A) is used. It is usually 10 to 800 parts by mass, preferably 20 to 300 parts by mass with respect to 100 parts by mass.

<Crosslinking agent>
The rubber composition according to the present invention may contain a cross-linking agent.
Examples of the cross-linking agent include vulcanizing agents such as sulfur and sulfur compounds, and organic peroxides.

(Vulcanizing agent)
Examples of vulcanizing agents include sulfur (sulfur) and sulfur compounds.
Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, and insoluble sulfur. Sulfur also functions as a cross-linking aid when organic peroxides, described below, are used.

Examples of sulfur compounds include sulfur chloride, sulfur dichloride, high molecular weight polysulfide, and sulfur compounds that release active sulfur at the brewing temperature to sulphurize (eg, morpholine disulfide, alkylphenol disulfide, tetramethyl). Sulfur disulfide, dipentamethylene thiuram tetrasulfide, selenium dimethyldithiocarbamate) can be mentioned.

Of these, sulfur is preferred.
These may be used alone or in combination of two or more.
When the vulcanizing agent is used, the amount of the vulcanizing agent in the rubber composition according to the present invention is usually 0.1 to 10 parts by mass with respect to 100 parts by mass of the copolymer rubber (A). It is preferably 0.3 to 5 parts by mass.

(Vulcanization accelerator)
It is preferable to use a vulcanization accelerator in combination with the vulcanization agent.
As an example of the vulcanization accelerator,
Sulfenamide compounds such as N-cyclohexyl-2-benzothiazolesulfenamide, N-oxydiethylene-2-benzothiazolsulfenamide, N, N-diisopropyl-2-benzothiazolsulfenamide;
2-Mercaptobenzothiazole (eg, Sunseller M (trade name, manufactured by Sanshin Chemical Industry Co., Ltd.)), 2- (2', 4'-dinitrophenyl) mercaptobenzothiazole, 2- (morpholinodithio) benzothiazole ( Example: Thiazole compounds such as Noxeller MDB-P (trade name, manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) and dibenzothiazole disulfide (eg Suncella DM);
Guanidine compounds such as diphenylguanidine, diorsotril guanidine, diorsonitrile guanidine, orthonitrile big guanide, diphenylguanidine phthalate;
Aldehyde amines or aldehyde-ammonia compounds such as acetaldehyde-aniline reactants, butyraldehyde-aniline condensates, hexamethylenetetramine, acetaldehyde ammonia;
2-Imidazolines compounds such as mercaptoimidazoline;
Thioyuria compounds such as thiocarbanilide, diethylthioyuria, N, N'-dibutylthioyuria (eg, Sunseller BUR), trimethylthioyuria, diorsotrilthioyuria;
Tetramethyl thiuram monosulfide (eg, Sunseller TS), tetramethyl thiuram disulfide (eg, Sunseller TT), tetraethyl thiuram disulfide (eg, Sunseller TET), tetrabutyl thiuram disulfide (eg, Sunseller TBT), dipentamethylene thiuram tetrasulfide. Thiram compounds such as (eg, Sunseller TRA);
Zinc dimethyldithiocarbamate (eg, Sunseller PZT), zinc diethyldithiocarbamate (eg, Sunseller EZT), lead dibutyldithiocarbamate (eg, Sunseller BT), zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate. , Dithioate compounds such as selenium dimethyldithiocarbamate, telluryl dimethyldithiocarbamate;
Zantate compounds such as zinc dibutylxanthate;
Zinc oxide (zinc oxide)
("Suncellor" is a trade name of a vulcanization accelerator manufactured by Sanshin Chemical Industry Co., Ltd.). These may be used alone or in combination of two or more.

When the vulcanization accelerator is used, the amount of the vulcanization accelerator in the rubber composition according to the present invention is usually 0.1 to 20 mass by mass with respect to 100 parts by mass of the copolymer rubber (A). Parts, preferably 0.2 to 10 parts by mass.

(Organic peroxide)
Examples of the organic peroxides include dicumyl peroxide, di-t-butyl peroxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butylhydroperoxide, and t-butyl. Cumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxyn) hexin-3, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2, Examples thereof include 5-dimethyl-2,5-mono (t-butylperoxy) -hexane and α, α'-bis (t-butylperoxy-m-isopropyl) benzene. Among these, dicumyl peroxide, di-t-butyl peroxide, and di-t-butylperoxy-3,3,5-trimethylcyclohexane are preferable. These may be used alone or in combination of two or more.

When the organic peroxide is used, the amount of the organic peroxide in the rubber composition according to the present invention is usually 0.0003 to 0.05 mol with respect to 100 g of the copolymer rubber (A). It is preferably 0.001 to 0.03 mol.

(Crosslinking aid)
It is preferable to use a cross-linking aid in combination with the organic peroxide.
Examples of the cross-linking aid include quinone dioxime compounds such as p-quinone dioxime, methacrylate compounds such as polyethylene glycol dimethacrylate, allyl compounds such as diallyl phthalate and triallyl cyanurate, maleimide compounds, and divinyl. Examples include benzene. These may be used alone or in combination of two or more.

When the cross-linking aid is used, the amount of the cross-linking aid in the rubber composition according to the present invention is 0.5 to 2 mol, preferably approximately equal to 1 mol of the organic peroxide used. It is a mole.

<Softener>
The rubber composition according to the present invention may contain a softening agent.
As the softening agent, a softening agent usually blended in a rubber composition can be used.

As an example of the softener,
Petroleum-based softeners such as process oils, lubricating oils, paraffins, liquid paraffins, petroleum asphalts, and petrolatum;
Coal tar softeners such as coal tar and coal tar pitch;
Fat oil-based softeners such as castor oil, flax oil, rapeseed oil, and coconut oil;
Tall oil;
sub;
Waxes such as beeswax, carnauba wax, and lanolin;
Fatty acids and fatty acid salts such as ricinoleic acid, palmitic acid, barium stearate, calcium stearate, zinc laurate;
Examples thereof include synthetic polymer substances such as petroleum resin, atactic polypropylene, and kumaron inden resin. Among these, petroleum-based softeners are preferable, and process oils are particularly preferable. These may be used alone or in combination of two or more.

When the softener is used, the amount of the softener in the rubber composition according to the present invention is usually 150 parts by mass or less, preferably 130 parts by mass, based on 100 parts by mass of the copolymer rubber (A). It is as follows.

<Processing aid>
The rubber composition according to the present invention may contain a processing aid.
As the processing aid, a processing aid usually blended in the rubber composition can be used.

As an example of the processing aid,
Higher fatty acids such as goricinolic acid, stearic acid, palmitic acid, lauric acid;
Higher fatty acid salts such as barium stearate, zinc stearate, calcium stearate;
Examples thereof include higher fatty acid esters such as ricinoleic acid ester, stearic acid ester, partiminic acid ester, and lauric acid ester. These may be used alone or in combination of two or more.

When the processing aid is used, the amount of the processing aid in the rubber composition according to the present invention is usually 10 parts by mass or less, preferably 5 parts by mass with respect to 100 parts by mass of the copolymer rubber (A). It is less than a part by mass.

<Other ingredients>
The rubber composition according to the present invention includes various known compounding agents generally used in the production of rubber products, for example, aging, in addition to the above-mentioned components, depending on the use and performance of the crosslinked product (vulcanized product). Inhibitors, activators, reaction inhibitors, colorants, dispersants, flame retardants, plasticizers, antioxidants, scorch inhibitors, UV absorbers, antistatic agents, lubricants, antifungal agents, vulcanization accelerators, adhesive Additives, dyes (dispersion dyes, acidic dyes, etc.), inorganic / organic pigments, surfactants, compounding agents for foaming (foaming agents, foaming aids, etc.), or defoaming agents impair the object of the present invention. It may be appropriately selected within a range that does not exist, and blended in an appropriate amount.

(Manufacturing method of rubber composition)
The rubber composition according to the present invention is produced by a conventionally known production method of a rubber composition, except that the copolymer rubber (A) and the surface-treated carbon black (B) are used as raw materials thereof. Can be done.

As a method for producing the rubber composition according to the present invention, for example, the copolymer rubber (A) and the surface-treated carbon are used by internal mixers (sealed mixers) such as a Banbury mixer, a kneader, and an intermix. Black (B) and, if necessary, a reinforcing material, a softener (for oil spreading), a processing aid, a vulcanization accelerator and the like are kneaded at a temperature of 80 to 170 ° C. for 2 to 20 minutes. Then, a softening agent, a vulcanizing agent (for example, sulfur), a vulcanization accelerator, and, if necessary, an additive such as a foaming agent and a cross-linking agent are added to the obtained blend in rolls such as open rolls. Alternatively, using a kneader, a vulcanization accelerator, a cross-linking aid, a foaming aid, and a de-methodizing agent are additionally mixed as necessary, kneaded at a roll temperature of 40 to 80 ° C. for 5 to 30 minutes, and then dispensed. Can be manufactured by

[Rubber molded product]
The rubber molded product according to the present invention is made of a crosslinked product (vulcanized product) of the rubber composition according to the present invention, and has excellent slidability. Therefore, it can be used for various purposes such as automobile parts, home appliance-related parts, civil engineering / building material-related parts, miscellaneous goods, and daily necessities.

An example of such an application is
Automotive and Aircraft Weather Strips (eg Door Weather Strips, Trunk Weather Strips, Luggage Weather Strips, Roof Side Rail Weather Strips, Sliding Door Weather Strips, Ventilator Weather Strips, Sliding Group Panel Weather Strips, Front Window Weather Strips, Rear Window Weather Strips Strips, Quarter Window Weather Strips, Rock Pillar Weather Strips, Door Glass Outer Weather Strips, Door Glass Inner Weather Strips),
Dam windshield, glass run channel, door mirror bracket, seal headlamp, seal cowl top;
Automotive hoses (eg brake hoses, radiator hoses, heater hoses, air cleaner hoses, water supply hoses),
Gas hose,
Building material seal parts (for example, gaskets, air tights, joint materials)
Door stop,
Home appliance seal parts,
Automotive cups and sealants (eg master cylinder piston cups, wheel cylinder piston cups),
Examples include sealing materials for industrial machinery, sheets, transmission belts or transport belts, coated electric wires, electric wire joints, electrically insulating parts, semi-conductive rubber parts, rolls for OA equipment, industrial rolls, household rubber products and shoes.

The rubber molded product of the present invention may be a foam molded product as long as the effects of the present invention are not impaired. Examples of the foamed molded product include a sponge for weather strips such as a sponge for door sponge, a sponge for opening trim, a sponge for hood seal, and a sponge for trunk seal, and a highly foamed sponge material such as heat insulating sponge and dam rubber.

(Manufacturing method of rubber molded product)
The rubber molded product according to the present invention is prepared by preparing an unvulcanized rubber composition according to the present invention by the method as described above, and then (or) in the same manner as when vulcanizing (crosslinking) general rubber. It can be produced by molding into a desired shape (at the same time) and then vulcanizing (crosslinking).

The unvulcanized rubber composition according to the present invention prepared as described above can be molded and vulcanized by various molding methods, preferably by mold molding such as compression molding, injection molding and injection molding. Can be molded and vulcanized.

In the case of compression molding, for example, a pre-weighed unvulcanized rubber composition according to the present invention is placed in a mold, and after the mold is closed, the rubber composition is heated at a temperature of 120 to 270 ° C. for 30 seconds to 120 minutes. A vulcanized rubber molded product is obtained.

In the case of injection molding, for example, a ribbon-shaped or pellet-shaped compounded rubber is supplied to the pot in a preset amount by a screw, and then the preheated compounded rubber is continuously fed into the mold by a plunger in 1 to 20 seconds. After injecting the compounded rubber, it is heated at a temperature of 120 to 270 ° C. for 30 seconds to 120 minutes to obtain a desired rubber molded product.

In the case of injection molding, for example, a pre-weighed compounded rubber is put into a pot, injected into a mold by a piston in 1 to 20 seconds, and after the compounded rubber is injected, it is heated at a temperature of 120 to 270 ° C. for 30 seconds to 120 minutes. By doing so, the desired vulcanized rubber molded product can be obtained.

Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.
[Characteristics of unvulcanized rubber]
<Moony viscosity>
Using a Mooney viscometer (SMV202 type manufactured by Shimadzu Corporation), the Mooney viscosity ML (1 + 4) of unvulcanized rubber was measured at 100 ° C. in accordance with JIS K6300.

[Vulcanized rubber characteristics]
<Hardness>
The hardness of the sheet (type A durometer hardness) was measured according to JIS K6253. However, six rubber sheets having a thickness of 2 mm were used as test pieces by stacking flat portions to have a thickness of about 12 mm. No test pieces containing foreign matter, air bubbles, or scratches were used. The size of the measurement surface of the test piece was set so that the tip of the push needle could be measured at a position 12 mm or more away from the end of the test piece.

<Tensile characteristics>
According to JIS K6251, a tensile test was conducted under the conditions of a measurement temperature of 23 ° C. and a tensile speed of 500 mm / min, and the tensile strength (T _b ) [MPa] and elongation (E _b ) [%] of the rubber sheet during cutting were measured. bottom.

[Comparative Example 1]
Ethylene / propylene / 5-ethylidene-2-norbornene ternary copolymer (trade name: Mitsui EPT 4045M, manufactured by Mitsui Chemicals, Inc.) 100 parts by mass, stearic acid 1 part by mass, zinc black 5 parts by mass, Carbon black (FEF) (trade name: Asahi # 60UG, manufactured by Asahi Carbon Co., Ltd., various physical properties are as shown in Table 1) 80 parts by mass and paraffin-based process oil (trade name: Diana Process PW-380, 50 parts by mass of Idemitsu Kosan Co., Ltd. was kneaded with a 1.7 liter capacity polymer mixer for 5 minutes.

Further, after winding this formulation on a 6-inch roll having a surface temperature of 50 ° C., a vulcanization accelerator (trade name: Sunseller M, manufactured by Sanshin Chemical Industry Co., Ltd.) was added to 236 parts by mass of this formulation. 0.5 parts by mass, 1 part by mass of vulcanization accelerator (trade name: Sunseller TT, manufactured by Sanshin Chemical Industry Co., Ltd.) and 1.5 parts by mass of sulfur were added and kneaded for 8 minutes. I let things cool.

From this compound (unvulcanized rubber composition), a rubber sheet (vulcanized rubber) having a thickness of 2 mm was prepared by vulcanizing at 160 ° C. for 20 minutes using a press molding machine.
The physical properties of the formulation (unvulcanized rubber) and rubber sheet (vulcanized rubber) obtained as described above were measured by the above method. The results are shown in Table 2.

[Example 1]
Carbon black (FEF) surface-treated with methylhydrogenpolysiloxane (trade name: SI01-4 DK, manufactured by Daito Kasei Co., Ltd., various physical properties are as shown in Table 1) changed to 80 parts by mass. A formulation (unsulfurized rubber) and then a rubber sheet (sulfurized product) were prepared in the same manner as in Comparative Example 1 except for the above.

The physical properties of the formulation (unvulcanized rubber) and rubber sheet (vulcanized rubber) obtained as described above were measured by the above method. The results are shown in Table 2.

Claims (6)

(A) Ethylene α- having a structural unit (a1) derived from ethylene, a structural unit (a2) derived from an α-olefin having 3 or more carbon atoms, and a structural unit (a3) derived from a non-conjugated polyene. A rubber composition containing carbon black surface-treated with an olefin / non-conjugated polyene copolymer rubber and (B) an organohydrogen polysiloxane compound. The rubber composition according to claim 1, wherein the non-conjugated polyene comprises at least one selected from the group consisting of 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene. The rubber composition according to claim 1 or 2, wherein the α-olefin contains propylene. The rubber according to any one of claims 1 to 3, wherein the content of the surface-treated carbon black (B) is 1 to 400 parts by mass with respect to 100 parts by mass of the copolymer rubber (A). Composition. The rubber composition according to any one of claims 1 to 4, further comprising a cross-linking agent. A rubber molded product made of a crosslinked product of the rubber composition according to claim 5.