JP2002146125A - Oil-extended rubber and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ethylene/α-olefin/non-conjugated diene copolymer-based oil-extended rubber which gives a vulcanized product improved in mechanical strengths, compression permanent set, impact resilience, and the like, when vulcanized. SOLUTION: This oil-extended rubber comprising (A) 100 pts.wt. of an ultrahigh mol.wt. ethylene/α-olefin/non-conjugated diene copolymer rubber having an intrinsic viscosity of >=5.5 dl/g (measured at 135 deg.C in decalin solvent) and (B) X mol.wt. of a mineral oil-based extending oil, characterized in that the Moony viscosity Y (ML1+4, 190 deg.C) of the oil-extended rubber and the amount X mol.wt. of the extending oil satisfy the following expression: Y>=-0.5X+80...(1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ultrahigh molecular weight ethylene / α-olefin / non-conjugated diene copolymer rubber which is blended with a mineral oil-based extender oil to provide mechanical strength and compression elongation when vulcanized. The present invention relates to an oil-extended rubber from which a vulcanizate excellent in distortion and the like and having high rebound resilience can be obtained, and a method for producing the oil-extended rubber.

[0002]

2. Description of the Related Art Ethylene / α-olefin / conjugated diene copolymer rubber is used for rubber materials for automobiles such as weatherstrip materials including sponges, rubber materials for building materials, rubber belts and the like.
It is used in a wide range of applications such as rubber roller materials, rubber materials for vibration isolation, thermoplastic elastomer modifiers, tubes, hoses, and general rubber products. In this case, the ethylene / α-olefin / conjugated diene copolymer rubber is often used as an oil-extended rubber oil-extended with an extension oil from the viewpoint of improving processability.

[0003] On the other hand, in the above-mentioned applications of ethylene / α-olefin / non-conjugated diene copolymer rubber, an oil-extended rubber which gives a vulcanizate having improved mechanical strength, compression set, rebound resilience and the like is required. ing. However,
Existing vulcanizates of oil-extended rubber have problems such as insufficient mechanical strength, compression set, and rebound resilience.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an oil-extended rubber which gives a vulcanized product which, when vulcanized, has improved mechanical strength, compression set, rebound resilience, etc., and a method for producing the same. It is in.

[0005]

According to the present invention, there is provided an oil-extended rubber using an ultra-high molecular weight ethylene / α-olefin / non-conjugated diene copolymer rubber, and a method for producing the oil-extended rubber. The above object of the invention is achieved. (1) 100 parts by weight of an ultrahigh molecular weight ethylene / α-olefin / non-conjugated diene copolymer rubber having an intrinsic viscosity (measured in a decalin solvent at 135 ° C.) of 5.5 dl / g or more; An oil-extended rubber containing X parts by weight of a system-extended oil, wherein Mooney viscosity Y (ML _{1 + 4} , 19
(0 ° C.) and an oil-extended amount X parts by weight satisfy the following formula (1). Y ≧ −0.5X + 80 (1) (2) The oil-extended rubber according to the above (1), wherein the α-olefin of the component (A) is propylene and the non-conjugated diene is ethylidene norbornene. (3) (B) Viscosity specific gravity constant (VG.
C. Oil-extended rubber according to the above (1) or (2), wherein (value) is 0.790 to 0.999. (4) Mooney viscosity Y of oil-extended rubber (ML _{1 + 4,} 190 ° C)
(1) to (1) to wherein the oil extension amount X parts by weight satisfies the following expression (2).
(3) The oil-extended rubber according to any of the above. Y ≧ −0.5X + 90 (2) (5) (A) Ultra-high molecular weight ethylene having an intrinsic viscosity (measured in a decalin solvent at 135 ° C.) of 5.5 dl / g or more.
(B) Mineral oil-based extender oil 1 to 100 parts by weight (solid content conversion) of α-olefin / non-conjugated diene copolymer rubber solution
The oil-extended rubber according to any one of the above (1) to (4), comprising: a first step of mixing 200 parts by weight in a solution state; and a second step of removing a solvent from the mixed solution obtained in the first step. Production method.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION (A) Ultra-high molecular weight ethylene / α-olefin / non-conjugated diene copolymer rubber used in the present invention (hereinafter also referred to as “(A) copolymer rubber of the present invention”)
Is ethylene, an α-olefin having 3 to 20 carbon atoms,
And a non-conjugated diene. 3 carbon atoms used
Examples of the α-olefin of -20 to -20 include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene and the like. -Hexene, 1-
Octene, more preferably propylene, is used.
These α-olefins can be used alone or in combination of two or more. The content of the ethylene component is from 50 to 80% by weight, preferably from 60 to 80% by weight, based on all the monomer components.
75% by weight. When the ethylene component content is within the above range, the rubber-like properties and low-temperature properties of the vulcanized rubber obtained from the oil-extended rubber become appropriate. When the ethylene component content exceeds 80% by weight, compression set at a low temperature of the vulcanized rubber deteriorates, while when it is less than 50% by weight,
Problems such as a decrease in the productivity of the copolymer rubber and an increase in cost are not preferred.

[0007] Non-conjugated dienes include, for example, 5
-Ethylidene-2-norbornene, dicyclopentadiene, 5-propylidene-2-norbornene, 5-vinyl-2-norbornene, 2,5-norbornadiene, 1,
Cyclic polyenes such as 4-cyclohexadiene, 1,4-cyclooctadiene, and 1,5-cyclooctadiene;
1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 5-methyl-
1,5-heptadiene, 6-methyl-1,5-heptadiene, 6-methyl-1,6-octadiene, 7-methyl-
1,6-octadiene, 5,7-dimethyl-1,6-octadiene, 7-methyl-1,7-nonadiene, 8-methyl-1,7-nonadiene, 8-methyl-1,8-decadiene, 9- Methyl-1,8-decadiene, 4-ethylidene-1,6-octadiene, 7-methyl-4-ethylidene-1,6-octadiene, 7-methyl-4-ethylidene-1,6-nonadiene, 7-ethyl- 4-ethylidene-
Internal unsaturated bonds having 6 to 15 carbon atoms such as 1,6-nonadiene, 6,7-dimethyl-4-ethylidene-1,6-octadiene, and 6,7-dimethyl-4-ethylidene-1,6-nonadiene A chain polyene having 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene,
Α, ω- such as 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, 1,11-dodecadiene, 1,12-tridecadiene, and 1,13-tetradecadiene
A diene, and preferably 5-ethylidene-2-
Norbornene, dicyclopentadiene, 5-vinyl-2
-Norbornene, 7-methyl-1,6-octadiene,
5-methyl-1,4-hexadiene is mentioned, and more preferably, 5-ethylidene-2-norbornene is used. These non-conjugated dienes can be used alone or in combination of two or more.

The non-conjugated diene has an iodine value of 5 to 40, preferably 7 to 30. This iodine value is a measure of the content of the non-conjugated diene component. If the iodine value is less than 5, crosslinking becomes insufficient, and the compression set of the vulcanized rubber deteriorates. When the amount exceeds the above range, gelation is apt to occur during kneading, and troubles such as occurrence of bumps are liable to occur in a molding process such as extrusion.

The (A) copolymer rubber of the present invention has an intrinsic viscosity [η] of 5.5 in a decalin solvent measured at 135 ° C.
dl / g or more, preferably 5.6 to 12 dl / g, more preferably 6.0 to 10 dl / g. When the intrinsic viscosity is less than 5.5 dl / g, use of a filler having low reinforcing property,
Or, under low filling, the strength is insufficient. In addition, 12d
Copolymer rubber exceeding 1 / g is difficult to produce. The intrinsic viscosity of the (A) copolymer rubber of the present invention is ethylene · α
-It means that the olefin / non-conjugated diene copolymer rubber has a very high molecular weight. In the present invention, a specific amount of a mineral oil-based extender oil is extended to a copolymer rubber having such a high molecular weight in the production stage, and an oil-extended rubber that satisfies the above formula (1) is produced. The above properties of the vulcanized rubber are improved while maintaining good processability. If the intrinsic viscosity of the (A) copolymer rubber of the present invention is less than 5.5 dl / g, the oil extension amount in the above range may not satisfy the formula (1). The intrinsic viscosity of the (A) copolymer rubber of the present invention can be achieved by adjusting the amount of catalyst and hydrogen gas as a molecular weight regulator used in the following method for producing a copolymer rubber of the present invention. .

[0010] The weight average molecular weight of the copolymer rubber (A) of the present invention is usually 1.3 to 6 million, preferably 1 to 6,000,000.
500,000-2,200,000, the number average molecular weight is usually 200,000-3,
It is 100,000, preferably 300,000 to 900,000, and the molecular weight distribution (Mw / Mn) is usually 2.0 to 6.0, preferably 2.2 to 5.0.

The copolymer rubber (A) of the present invention can be produced by an appropriate method such as a gas phase polymerization method, a solution polymerization method and a slurry polymerization method. These polymerization operations can be carried out in a batch system or a continuous system. In the above solution polymerization method or slurry polymerization method, an inert hydrocarbon is usually used as a reaction medium. Such inert hydrocarbon solvents include, for example, n-pentane, n-
Hexane, n-heptane, n-octane, n-decane,
aliphatic hydrocarbons such as n-dodecane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and aromatic hydrocarbons such as benzene, toluene and xylene. These hydrocarbon solvents can be used alone or in combination of two or more. Further, the raw material monomer can be used as a hydrocarbon solvent.

As the polymerization catalyst used for producing the copolymer rubber (A) of the present invention, for example, an olefin polymerization catalyst comprising a compound of a transition metal selected from V, Ti, Zr and Hf and an organometallic compound is used. Can be mentioned. The transition metal compound and the organometallic compound can be used alone or in combination of two or more. Particularly preferred examples of such an olefin polymerization catalyst include metallocene catalysts comprising a metallocene compound and an organoaluminum compound or an ionic compound which reacts with the metallocene compound to form an ionic complex;
Alternatively, a Ziegler-Natta catalyst comprising a vanadium compound and an organoaluminum compound can be used. In the production of the copolymer rubber (A), hydrogen gas may be used as a molecular weight regulator. The amount of hydrogen gas used varies depending on the type of catalyst, the amount of catalyst, the polymerization conditions such as polymerization temperature and polymerization pressure, and the polymerization process such as polymerization scale, stirring state, and charging method.For example, a Ziegler-Natta catalyst was used. In solution polymerization, it is usually 0.01 to 20 ppm, preferably 0.1 to 19 ppm, based on all monomer components.

The oil-extended rubber of the present invention is obtained by adding (B) mineral oil-based extender oil (X parts by weight) to (A) 100 parts by weight of the ultrahigh molecular weight ethylene / α-olefin / non-conjugated diene copolymer rubber of the present invention. Mooney viscosity Y (ML _{1 + 4,}
(190 ° C.) and an oil-extended rubber which satisfies the following formula (1), preferably the following formula (2), and more preferably the following formula (3). Y ≧ −0.5X + 80 (1) Y ≧ −0.5X + 90 (2) Y ≧ −0.5X + 95 (3) In the above equation (1), the value of Y is (− 0.5X + 8
Below 0), the mechanical strength of the vulcanized rubber, compression set,
It is difficult to exhibit high rebound resilience.

As described above, the present invention is particularly characterized in that the Mooney viscosity of the oil-extended rubber is measured at a high temperature of 190 ° C. and the above formula (1) is satisfied. Usually, the Mooney viscosity of an oil-extended rubber is measured at a temperature of about 100 ° C. to 125 ° C., but the oil-extended rubber of the present invention uses an ultra-high molecular weight ethylene / α-olefin / non-conjugated diene copolymer rubber. Therefore, in this temperature range, the rotor of the measuring instrument slips, and the Mooney viscosity cannot be measured properly.
The present inventors have found that the Mooney viscosity can be appropriately measured by measuring at a high temperature of 190 ° C. The Mooney viscosity Y measured at 190 ° C. and the oil extension amount X by weight satisfy the above formula (1).
It became clear that the vulcanized rubber obtained from the oil-extended rubber was extremely important together with the oil-extended amount for improving the physical properties such as mechanical strength, compression set, and rebound resilience. When the formula (1) is not satisfied, the above characteristics are not improved. Formula (1) can be satisfied by adjusting the oil extension amount within the above range according to the intrinsic viscosity of the ethylene / α-olefin / non-conjugated diene copolymer rubber.

The amount of the mineral oil-based extender oil (B) used is preferably 1 to 100 parts by weight of the copolymer rubber (A).
200 parts by weight, more preferably 70 to 150 parts by weight,
Particularly preferred is 80 to 130 parts by weight. If the amount of the mineral oil-based extender oil (B) is less than 1 part by weight based on 100 parts by weight of the (A) copolymer rubber, the production is difficult.
If the amount exceeds 0 parts by weight, processing is difficult due to poor dispersion of the filler. By using the mineral oil-based extender oil in the above range, the operability during kneading of the obtained oil-extended rubber is improved. By using (B) mineral oil-based extender oil in an amount of 70 parts by weight or more, the unvulcanized rubber sheet appearance (blended rubber sheet skin) is improved.

The mineral oil-based extender oil (B) used in the oil-extended rubber of the present invention is preferably a viscosity specific gravity constant (or viscosity specific gravity constant; hereinafter abbreviated as VGC). ) Is 0.790 to 0.999, and more preferably V.I. G. FIG. C. Is 0.790 to 0.949, particularly preferably V.I. G. FIG. C. Is 0.790 to 0.912. As the extender oil, generally, an aromatic extender oil,
Naphthenic extender oil and paraffin extender oil are known.

Among these, as the aromatic extender oil satisfying the above viscosity specific gravity constant, Diana Process Oil AC-12, AC460, AH- manufactured by Idemitsu Kosan Co., Ltd.
16, AH-58, manufactured by Exxon Mobil Co., Ltd., Mobilzol K, 22 and 130, manufactured by Nikko Kyoishi Co., Ltd., manufactured by Kyoishi Processes X50, X100, X140, manufactured by Shell Chemical Co., Ltd. Resox No. 3. Deuterex 729UK, manufactured by Nisseki Mitsubishi Co., Ltd. (former Nippon Oil Co., Ltd.), Comolex 200, 300, 500, 700;
ExxonMobil Esso Process Oil 1
10, 120, Nisseki Mitsubishi Co., Ltd. [former Mitsubishi Oil Co., Ltd.]
And Mitsubishi 39 heavy process oil, Mitsubishi 39 heavy process oil, Mitsubishi 39 heavy process oil, and the like.

As the naphthenic extender oil satisfying the above viscosity specific gravity constant, Diana Process Oil NS-24, NS-100, NM-26, N manufactured by Idemitsu Kosan Co., Ltd.
M-280, NP-24, Naplex 38 manufactured by ExxonMobil Co., Ltd., Fukkor F manufactured by Fujikosan Co., Ltd.
LEX # 1060N, # 1150N, # 1400N, #
2040N, # 2050N, Kyoishi processes R25, R50, R200, R1000 manufactured by Nikko Kyoishi Co., Ltd., Shellflex 371JY manufactured by Shell Chemical Co., Ltd., 3
71N, 451, N-40, 22, 22, 22R, 32R, 100R, 100S, 100SA, 2
20RS, 220S, 260, 320R, 68
0, Komorix No. 2 process oil manufactured by Nisseki Mitsubishi Co., Ltd. [former Nippon Oil Co., Ltd.], Esso Process Oil L-2, 765 manufactured by ExxonMobil Co., Ltd., Nisseki Mitsubishi Co., Ltd. [ Former Mitsubishi Oil Co., Ltd.] Mitsubishi 20 Light Process Oil.

Further, as paraffin-based extender oil satisfying the above viscosity specific gravity constant, Diana Process Oil PW-90, PW-380, PS-3 manufactured by Idemitsu Kosan Co., Ltd.
2, PS-90, PS-430, manufactured by Fujikosan Co., Ltd.
Fukkor Process P-100, P-200, P-30
0, P400, P-500, Kyoishi Process P-200, P-300, P-500, Kyoishi E manufactured by Nikko Kyoishi Co., Ltd.
PT750, 1000, Kyoishi process S90, manufactured by Shell Chemical Co., Ltd., Lubrex 26, 100, 46
0, Esso Process Oil 815, 845, and B-1 manufactured by ExxonMobil Co., Ltd., Naplex 32 manufactured by ExxonMobil Co., Ltd., manufactured by Nisseki Mitsubishi Co., Ltd. (formerly Mitsubishi Oil Co., Ltd.) Mitsubishi 10 light process oil and the like.

Thus, (A) ultra high molecular weight ethylene.
Since the α-olefin / non-conjugated diene copolymer rubber is oil-extended with the mineral oil-based extender oil (B), fillers such as carbon black and silica can be uniformly finely dispersed in the copolymer rubber (A) of the present invention. It becomes possible to disperse, and it is possible to remarkably improve workability and various characteristics of a molded product. In addition, this makes it possible to surprisingly improve the molded appearance of the obtained compounded rubber and improve the mechanical strength, compression set and rebound resilience of a vulcanized rubber using this oil-extended rubber.

The oil-extending method is not particularly limited, but is preferably a method in which (B) a mineral oil-based extending oil is added to the polymerization solution of the (A) copolymer rubber of the present invention and mixed in a solution state. Can be. This method is operable according to (A) of the present invention.
The step of mixing the copolymer rubber and the mineral oil-based extender oil (B) can be omitted, which is preferable in that both are excellent in mixing uniformity. When the extender oil is added to the polymer solution, it is preferable after the end of the polymerization, for example, after the addition of a polymerization terminator. A required amount of extender oil is added to a polymer solution containing an organic solvent and mixed well in a solution state (first step). Next, a crumb is obtained by a steam stripping method in which steam is blown into the polymer solution containing the extension oil, or the polymer solution containing the extension oil is directly subjected to the first step by means of an extruder, a devolatizer, or the like. The solvent is removed from the mixed solution obtained in (1) to separate the oil-extended rubber from the solvent (second step). The obtained oil-extended rubber can be dried by a vacuum drier, a hot-air drier, a roll, or the like as necessary (third step) to isolate the target oil-extended rubber. Also, as an oil exhibition method,
An oil-extended rubber can also be prepared by blending (A) a copolymer rubber and (B) a mineral oil-based extender oil in a molten state. In this case, as a blending method, a single-screw extruder, a twin-screw extruder, a banbury, a roll, a kneader, a plast mill, or the like is employed, and a melt-kneading temperature of 60 to 180 ° C is suitable. By using the mineral oil-based extender oil in the above range, the operability during kneading and the appearance after molding are improved.

As described above, the oil-extended rubber of the present invention comprises (A)
It can be obtained by adding (B) mineral extender oil at any stage of the production operation after the copolymer rubber is produced by polymerization. For example, it may be added to the polymerization solution after the completion of the polymerization. In addition, mineral extender oil can be added in portions.

The oil-extended rubber of the present invention contains a filler, a vulcanizing agent,
A vulcanization accelerator, a vulcanization aid, a foaming agent, and other various compounding agents are mixed and kneaded in an appropriate amount according to the application to form a compounded rubber,
By vulcanization, a vulcanized rubber is obtained. At this time, the above-mentioned mineral oil-based extending oil may be included, and a softener may be additionally blended within a range not to impair the achievement of the object of the present invention. Softening agents that can be used include process oils, lubricating oils,
Paraffin, liquid paraffin, petroleum asphalt, petrolatum, coal tar pitch, castor oil, linseed oil, sub, beeswax, ricinoleic acid, palmitic acid, barium stearate, calcium stearate, zinc laurate, atactic polypropylene, cumarone indene resin And the like.

The fillers that can be used in the present invention include carbon black, finely divided silica, glass powder, glass beads, mica, calcium carbonate, potassium titanate whisker, talc, clay, barium sulfate, glass flake, fluorine Resins and the like can be mentioned. Among them, carbon black is preferably used from the viewpoint of improving the strength of the vulcanized rubber and reducing the cost of the vulcanized rubber. Carbon black includes SRF, GPF, FEF, HA
F, ISAF, SAF, FT, MT, etc.
Either can be used, but SRF, F
The use of EF and GPF is preferred. Although the amount of the filler varies depending on the application, it is 5 to 300 parts by weight, preferably 10 to 20 parts by weight, per 100 parts by weight of the (A) copolymer rubber of the present invention.
0 parts by weight.

As the vulcanizing agent, sulfur; sulfur compounds such as sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, selenium dimethyldithiocarbamate; dicumyl peroxide, 2,5-dimethyl −
2,5-di (tert-butylperoxy) hexane, 2,5
-Dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-dimethyl-2,5-
Organic peroxides such as di (tert-butylperoxy) hexine-3, di-tert-butyl peroxide, di-tert-butyloxy-3,3,5-trimethylcyclohexane, tert-butyl hydroperoxide and the like can be mentioned. Among them, sulfur, dicumyl peroxide, ditertiary butyl peroxide and ditertiary butylperoxy-3,3,5-trimethylcyclohexane are preferred.

The sulfur or sulfur-based compound is usually used in an amount of 0.1 to 100 parts by weight of the copolymer rubber (A) of the present invention.
It is used in a proportion of 1 to 10 parts by weight, preferably 0.5 to 5 parts by weight. The organic peroxide is used in an amount of usually 0.1 to 15 parts by weight, preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the copolymer rubber (A) of the present invention. When sulfur or a sulfur-based compound is used as a vulcanizing agent, a vulcanization accelerator and a vulcanization aid are used in combination, if necessary.

Examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazole-sulfenamide, N-oxydiethylene-2-benzothiazole-sulfenamide, N, N-diisopropyl-2-benzothiazolesulfenamide, 2-mercapto Benzothiazole, 2
-(2,4-dinitrophenyl) mercaptobenzothiazole, 2- (2,6-diethyl-4-morpholinothio) benzothiazole, dibenzothiazyl-disulphide; diphenylguanidine, triphenylguanidine,
Diorthotolylguanidine, orthotolylguanide, diphenylguanidine phthalate; acetaldehyde-aniline reactant, butyraldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde ammonia; 2-mercaptoimidazoline; thiocarbanilide, diethylthiourea, dibutylthiourea , Trimethylthiourea, diortho tolyl thiourea; tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulphide, tetrabutylthiuram disulfide, pentamethylenethiuram tetrasulfide, zinc dimethyldithiocarbamate,
Zinc diethylthiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, tellurium diethyldithiocarbamate;
Zinc dibutylxanthogenate and the like can be mentioned. These vulcanization accelerators are the (A) copolymer rubber 1 of the present invention.
It is used in a proportion of usually 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, based on 00 parts by weight.

Examples of the vulcanization aid include metal oxides such as magnesium oxide and zinc white, and the use of zinc white is preferred. These vulcanization aids are usually used in an amount of from 1 to 2 parts by weight per 100 parts by weight of the (A) copolymer rubber of the present invention.
0 parts by weight, preferably 3 to 10 parts by weight are used.

When vulcanizing with a peroxide, quinone dioximes such as sulfur and p-quinone dioxime are used.
Crosslinking aids such as polyethylene glycol dimethacrylate, diallyl phthalate, triallyl cyanurate, and divinylbenzene may be used. This crosslinking aid is usually added to 100 parts by weight of the (A) copolymer rubber of the present invention.
0.1 to 20 parts by weight, preferably 0.1 to 10 parts by weight is used.

When producing a foam, a foaming agent is blended. Examples of the foaming agent include sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, ammonium nitrite, N, N'-dimethyl N, N'-dinitrone terephthalamide, N, N'-dinitrone pentamethylenetetramine, azo Dicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile, azodiaminobenzene, barium azodicarboxylate, benzenesulfonylhydrazide, toluenesulfonylhydrazide, P, P'-oxybis (benzenesulfonylhydrazide), diphenylsulfone-3 , 3'-disulfonylhydrazide, calcium azide, 4,4'-diphenyldisulfonyl azido valatolulmonyl azide. The foaming agent is usually 0.5 to 30 parts by weight based on 100 parts by weight of the (A) copolymer rubber of the present invention.
Preferably, it is blended in a ratio of 1 to 15 parts by weight. Also,
If necessary, a foaming aid may be used in combination with the foaming agent.

As the rubber component, other types of rubber or other ethylene / α-olefin / non-conjugated diene copolymer may be used together with the copolymer rubber (A) of the present invention as long as the object of the present invention is not impaired. Rubber can be used in combination.

A compounded rubber can be prepared by kneading the oil-extended rubber and each of the above-mentioned additives using a conventionally known kneading machine. That is, the above compounded components can be added to the oil-extended rubber and kneaded using an open roll mill, a Banbury mixer, a kneader, or the like to obtain a compounded rubber. In this case, the melting and kneading temperature is usually 30 to 200 ° C, preferably 60 to 180 ° C.

Thereafter, the compounded rubber is formed into a desired shape by an extruder or a mold, and then, a high-frequency heating device, an air oven,
It can be vulcanized by a heating device such as PCM or LCM to obtain a vulcanized rubber product. Further, a vulcanized rubber product may be manufactured by a method of molding and vulcanizing in a mold using a vulcanizing apparatus known per se. The production of vulcanized rubber products varies greatly depending on the vulcanization method, formulation, and application. For example, in the case of press vulcanization, as vulcanization conditions, the heating temperature is preferably 140 to 200 ° C., and the heating time is 1 to 60. Minutes.

The above-described oil-extended rubber of the present invention includes rubber materials for automobiles such as weatherstrip materials including sponges, rubber materials for building materials, rubber belts, rubber roller materials, rubber materials for vibration damping, thermoplastic elastomer modifiers, It is suitably used for manufacturing hoses, industrial rubber products, and the like.

[0035]

EXAMPLES The present invention will be described below in detail with reference to examples, but the scope of the present invention is not limited by the examples. Each measurement and evaluation in the examples and comparative examples,
The procedure was as follows. (1) Ethylene content (% by weight) It was measured by an infrared absorption spectrum method. (2) Iodine value It was measured by an infrared absorption spectrum method. (3) Mooney viscosity (ML _{1 + 4,} 190 ° C.) Measured at a measurement temperature of 190 ° C., a residual heat time of 1 minute, and a time of 4 minutes until the viscosity was read. Parts by weight of extended oil added to 100 parts by weight of polymerized rubber The extended oil parts by weight were obtained from the oil component obtained by boiling the oil extended rubber with a 3/1 mixture of ethanol / toluene and the rubber component from which the oil component was extracted. .

(5) Evaluation of Compound Rubber Sheet Skin Rolls of the compound rubber were rolled out, and the sheet skin was visually evaluated. O: There is no unevenness on the surface, and the gloss is good. Δ: No surface unevenness, no gloss. ×: The surface is uneven, and there is no gloss. (6) Tensile test According to JIS K 6301, 100% modulus (M ₁₀₀ ), tensile stress at break (T _B ), tensile elongation at break (E _B ), and hardness (Dilometer D type, H _S ) It was measured. (7) Compression set In accordance with JIS K 6301, the compression set was measured at 70 ° C. for 22 hours. (8) Rebound resilience test Measured at 25 ° C according to JIS K6301.

The compounding agents (1) to (9) used are as follows. Compounding agent (1): Diana Process Oil PW-380 (extended oil) manufactured by Idemitsu Kosan Co., Ltd. (VGC value = 0.7
94) Compounding agent (2): 5 parts by weight of zinc flower manufactured by Nippon Chemical Industry Co., Ltd. Compounding agent (3): 1 part by weight of stearic acid manufactured by NOF CORPORATION Compounding agent (4): Nip seal manufactured by Nippon Silica Co., Ltd. VN
(Silica fine particles) 10 parts by weight Compounding agent (5): dibenzothiacyl disulfide
5 parts by weight Compounding agent (6): 1.5 parts by weight of N-cyclohexyl-2-benzothiazyl sulfenamide Compounding agent (7): Tetraethylthiuram disulfide
0.7 part by weight Compounding agent (8): dipentamethylenethiuram tetrasulfide 0.7 part by weight Compounding agent (9): 0.5 part by weight of sulfur Compounding amounts of the compounding agents (2) to (8) are copolymerized. The value is based on 100 parts by weight of rubber.

Reference Examples 1 to 6 (Intrinsic viscosity = 7.1, 6.
Ultra high molecular weight EP of 2, 6.0, 5.6, 5.5 dl / g
Production of R) According to a general production of a solution polymerization method, hexane is used as a solvent and an organic aluminum compound (C2H
5) In the presence of 1.5AlCl1.5, soluble vanadium compound VOCl3, ethylene, propylene, ENB (5-ethylidene-2-
Norbornene) was randomly copolymerized in such a ratio as to obtain a desired composition. In this case, VOCl3 was reduced to such an extent that it was not deactivated, and the amount of hydrogen gas used as a molecular weight regulator was adjusted to 20 ppm or less based on the amount of monomer used.

Comparative Reference Examples 1 to 3 (Intrinsic viscosity = 3.8,
4.4 Production of EPR of 5.3 dl / g) Using the same solvent and catalyst as in Reference Examples 1 to 6, and using the amount of hydrogen gas used as a molecular weight modifier under a relatively high activity state with respect to the monomer, It was manufactured by adjusting to 21 ppm or more.

Examples 1-4, Comparative Examples 1-2 The oil-extended rubbers of the ethylene / propylene / ethylidene norbornene copolymer rubbers of Examples 1-4 and Comparative Examples 1-2 shown in Table 1 were prepared after the polymerization. Was prepared by adding the above-mentioned extender oil [Blending agent (1)] to the polymerization solution of the above (1). Examples 2 to 4,
And in the case of Comparative Examples 1-2, the above compounding agent (1)
[Extension oil] was added in an amount of 105 parts by weight in the compounded rubber in accordance with the oil extension amount to 100 parts by weight of the copolymer rubber. Further, the above-mentioned compounding agents (2) to (4) were added in the amounts described above, and the mixture was kneaded with a BR-type Banbury mixer (content: 1.7 liter) set at 50 ° C. for 3 minutes at a rotation speed of 60 rpm to obtain a compounded rubber. I got Then, the unvulcanized rubber composition obtained by blending the above-mentioned blending agents (5) to (9) with the above-described blending agents (5) to (9) with a 10-inch roll kept at 50 ° C and kneading the mixture was mixed at 160 ° C. 2 in the steam press
After heating for 0 minutes, a vulcanized sheet was obtained. Compression set, JI
The sample for S rebound resilience measurement was 2
A test piece was obtained by heating for 5 minutes, and a physical property test was performed. Table 1 shows the evaluation results.

From the results shown in Table 1, the following is clear. The vulcanizates using the oil-extended rubber of the present invention of Examples 1 to 4 have excellent breaking strength, good breaking elongation, small compression set, and high rebound resilience. Further, the oil-extended rubber satisfying the above formula (3) has more excellent strength and compression set characteristics. On the contrary,
The oil-extended rubber of Comparative Example 2 has a low intrinsic viscosity of the copolymer rubber, a low Mooney viscosity of the oil-extended rubber, and does not satisfy Formula (1). The oil-extended rubber of Comparative Example 1 satisfies Formula (1). However, the vulcanized rubber obtained does not satisfy the intrinsic viscosity of the copolymer rubber and cannot exhibit excellent physical properties as compared with the case of using the oil-extended rubber of the present invention.

[0042]

[Table 1]

Examples 5 to 6, Comparative Example 3 The oil-extended rubber of the ethylene / propylene / ethylidene norbornene copolymer rubber of Examples 5 to 6 and Comparative Example 3 described in Table 2 was added to the polymerization solution after the completion of the polymerization. It was prepared by adding the above-mentioned extender oil [Compound (1)]. Further, the above-mentioned compounding agents (2) to (4) were added in the amounts described above, and the mixture was added at 50 ° C.
The mixture was kneaded for 3 minutes at a rotation speed of 60 rpm with a BR type Banbury mixer (content: 1.7 liters) set as described above to obtain a compounded rubber. This compounded rubber was sheeted out with a 10-inch roll maintained at 50 ° C., and the skin of the sheet was visually evaluated. Table 2 shows the results. From the results in Table 2, the following is clear. In Comparative Example 3, when the oil-extended rubber having a low oil extension of less than 70 parts by weight was used, the sheet surface of the compounded rubber was inferior, and the oil-extension amounts were 80 parts by weight and 70 parts by weight, respectively. The oil-extended rubber obtained had a compounded rubber sheet having excellent skin.

[0044]

[Table 2]

[0045]

The oil-extended rubber obtained by oil-extending the ultrahigh-molecular-weight ethylene / α-olefin / non-conjugated diene copolymer rubber of the present invention with a mineral oil-based extender oil has a mechanical strength, compression set, It can give vulcanizates with improved rebound resilience, etc., and can be used for materials such as automotive rubber materials such as belts, rollers, vibration insulators, hoses, rubber materials for construction materials, weather strip materials, and industrial rubber products. It can be suitably used in the field of rubber products whose properties play an important role. Also,
By mixing with another rubber or a thermoplastic resin, it can be used as a modifier for improving the rebound resilience.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Fumio Tsutsumi 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside JSR Co., Ltd. (72) Minoru Tanaka 2-11-24 Tsukiji 2-chome, Chuo-ku, Tokyo JSR Incorporated F term (reference) 4F070 AA12 AA13 AA14 AA15 AA16 AA40 AA63 AE28 FA04 FA17 4J002 AE05X BB15W FD010 FD140 FD150 FD320 GC00 GL00 GM00 GM01 GN00

Claims (5)

[Claims] (A) An intrinsic viscosity (13% in decalin solvent)
Ultra high molecular weight ethylene / α-olefin / non-conjugated diene copolymer rubber 10 (measured at 5 ° C.) of 5.5 dl / g or more
(B) an oil-extended rubber containing X parts by weight of a mineral oil-based extender oil with respect to 0 parts by weight, wherein the Mooney viscosity Y (M
L _{1 + 4,} 190 ° C.) and an oil extension amount X parts by weight satisfying the following formula (1). Y ≧ −0.5X + 80 (1) 2. The oil-extended rubber according to claim 1, wherein the α-olefin of the component (A) is propylene and the non-conjugated diene is ethylidene norbornene. 3. The oil-extended rubber according to claim 1, wherein the viscosity specific gravity (VGC value) of the mineral oil-based extending oil (B) is 0.790 to 0.999. 4. The Mooney viscosity of oil-extended rubber Y (ML _{1 + 4,} 1
The oil-extended rubber according to any one of claims 1 to 3, wherein the oil-extended rubber (90 ° C) and the oil-extended amount X satisfy the following formula (2). Y ≧ −0.5X + 90 (2) (A) Intrinsic viscosity (13% in decalin solvent)
(B) mineral oil-based extender oil 1 with respect to 100 parts by weight (in terms of solid content) of an ultra-high molecular weight ethylene / α-olefin / non-conjugated diene copolymer rubber solution (measured at 5 ° C.) of 5.5 dl / g or more. The production of an oil-extended rubber according to any one of claims 1 to 4, comprising a first step of mixing a solution in an amount of from 200 to 200 parts by weight, and a second step of removing a solvent from the mixed solution obtained in the first step. Method.