Abstract: A rubber composition for fuel cell seals, HDD top cover gaskets or cable connector seals is disclosed. The rubber composition comprises a specific ethylene/?-olefin/non-conjugated polyene copolymer [A], a specific organopolysiloxane [B] and an SiH group-containing compound [C], with the weight ratio of [A]:[B] being 100:0 to 5:95. A fuel cell sealing material, HDD top cover gasket material, cable connector sealing material, fuel cell seal, HDD top cover gasket and cable connector seal according to the present invention comprise the composition. A fuel cell according to the present invention includes the fuel cell seal. A hard disk drive of the present invention includes the gasket. An automotive cable connector according to the present invention is sealed by the composition. The invention provides a crosslinkable rubber composition that has good high-speed moldability and can give fuel cell seals excellent in resistances to heat, acids and gas permeation.

Abstract: The crosslinkable rubber composition is crosslinkable at room temperature, has a gelation time at room temperature of 30 days or less, and can prepare a crosslinked rubber sheet by crosslinking the composition at room temperature, wherein the crosslinked rubber sheet has a tensile elongation of 20% or more, and is free of cracks after treatment at 40° C. in a 50 pphm ozone concentration for 96 hr. Specifically, it comprises an ethylene/&agr;-olefin/non-conjugated polyene random copolymer rubber comprising a norbornene compound having a specific vinyl end group, an SiH group-containing compound, which has at least two SiH groups in one molecule, and optionally a platinum catalyst, a reaction inhibitor and/or a silane-coupling agent. The sealing, potting and coating materials and adhesives of the present invention comprise the above rubber composition.

Abstract: The invention provides an ethylene-&agr;-olefin-unconjugated polyene random copolymer rubber having hydrolyzable silyl groups in the molecule, which is crosslinkable with air-borne moisture at room temperature and is not only useful for resin modification, but also applicable as elastic sealants and adhesives, and a method for preparing the same.

Abstract: A blend of a rubber and a rubber modifier, the rubber modifier comprising an ethylene/&agr;-olefin copolymer rubber (A) composed of one or more copolymers selected from the group consisting of a copolymer of ethylene and an &agr;-olefin having 3-20 carbon atoms and a copolymer of ethylene, an &agr;-olefin having 3-20 carbon atoms and a non-conjugated polyene, the copolymer rubber (A) having the parameters: an ethylene/&agr;-olefin mole ratio in the range of 51/49 to 87/13, an intrinsic viscosity [&eegr;] determined in decahydronaphthalene at 135° C. in the range of 0.8 to 2.5 dl/g and an iodine value in the range of 0 to 40.

Abstract: According to the present invention, there is provided a rubber composition for a conveyor belt comprising (A) 100 parts by weight of an ethylene/&agr;-olefin containing 3 to 20 carbon atoms/non-conjugated polyene copolymer rubber containing a diene unit derived from special non-conjugated dienes, (B) 0.5 to 15 parts by weight of an organic peroxide, (C) 30 to 80 parts by weight of a carbon black and (D) 5 to 25 parts by weight of a softening agent. This rubber composition provides excellent mechanical strength, heat resistance (including heat aging resistance), abrasion resistance and roll processability. It is especially preferred to convey a sintered product, a coke, a cement, clinker and quicklime.

Abstract: The curable composition of the present invention contains (A1) a silyl-containing ethylene/&agr;-olefin/non-conjugated polyene random copolymer rubber which has a structural unit derived from a norbornene compound as the non-conjugated polyene with at least one specific vinyl group at the terminal and contains a specific hydrolyzable silyl group, and (B) a compound, other than the rubber (A1), having a hydroxyl group and/or a hydrolyzable group, e.g., (B1) a compound having a silanol group and/or a compound which can react with moisture to form a compound having a silanol group in the molecule.

Abstract: The crosslinkable rubber composition is crosslinkable at room temperature, has a gelation time at room temperature of 30 days or less, and can prepare a crosslinked rubber sheet by crosslinking the composition at room temperature, wherein the crosslinked rubber sheet has a tensile elongation of 20% or more, and is free of cracks after treatment at 40° C. in a 50 pphm ozone concentration for 96 hr. Specifically, it comprises an ethylene/&agr;-olefin/non-conjugated polyene random copolymer rubber comprising a norbornene compound having a specific vinyl end group, an SiH group-containing compound, which has at least two SiH groups in one molecule, and optionally a platinum catalyst, a reaction inhibitor and/or a silane-coupling agent. The sealing, potting and coating materials and adhesives of the present invention comprise the above rubber composition.

Abstract: A rubber modifier comprises an ethylene/&agr;-olefin copolymer rubber (A) composed of one or more copolymers selected from the group consisting of a copolymer of ethylene and an &agr;-olefin having 3-20 carbon atoms and a copolymer of ethylene, an &agr;-olefin having 3-20 carbon atoms and a non-conjugated polyene, the copolymer rubber (A) having the parameters: an ethylene/&agr;-olefin mole ratio in the range of 51/49 to 87/13, an intrinsic viscosity [&eegr;] determined in decahydronaphthalene at 135° C. in the range of 0.8 to 2.5 dl/g and an iodine value in the range of 0 to 40.

Abstract: The present invention provides a raw rubber lapping film formed of an ethylene·&agr;-olefin random copolymer comprising ethylene unit and an &agr;-olefin unit having 4 to 20 carbon atoms and a raw rubber bale lapped with this film. Since the film is superior in strength and release properties and has good dispersibility in ethylene·&agr;-olefin copolymer rubber, the operation of lapping raw rubber with a film, the operation of stripping a film from a lapped raw rubber bale and the operation of separating each of a plurality of raw rubber bales are carried out easily and yet there is no adverse effect on the subsequent rubber processing step without stripping the film by heating at a temperature higher than the melting point of the film at the time of kneading.

Abstract: The heat-resistant rubber composition of the invention is a vulcanizable composition comprising 100 parts by weight of a specific ethylene-&agr;-olefin-nonconjugated polyene copolymer rubber (A) composed of ethylene, an &agr;-olefin or 3 to 20 carbon atoms and a nonconjugated polyene which is a vinyl end group-containing norbornene compound, 0.2 to 5 parts by weight of an amine type anti-aging agent (C) and/or a hindered phenol type anti-aging agent (D), 1 to 10 parts by weight of a sulfur type anti-aging agent (E) and an organic peroxide (B). This heat-resistant rubber composition can provide a vulcanized rubber molded product showing not only excellent mechanical properties and electrical properties and but also prominently high thermal aging resistance.

Abstract: A process for preparing an ethylene/.alpha.-olefin/norbornene nonconjugated polyene random copolymer, comprising preparing an ethylene random copolymer simultaneously meeting the following requirements (1) to (5):(1) the molar ratio of ethylene (a) to an .alpha.-olefin (b) having 3 to 20 carbon atoms ranges from 40:60 to 95:5;(2) a given amount of non conjugated polyene (c) has a norbornene skeleton;(3) the available network chain density .nu. is not less than 1.5.times.10.sup.20 /cm.sup.3 after press cross-linking of the copolymer using a dicumyl peroxyde;(4) the ratio of the rate .gamma.1 of shear showing a shearing stress of 0.4.times.10.sup.6 dyn/cm.sup.2 as determined from the melt flow curve at 100.degree. C. and the rate .gamma.2 of shear showing a shearing stress of 2.4.times.10.sup.6 dyn/cm.sup.2, that is .gamma.2/.gamma.1 and the available network chain density .nu. has a relationship represented by the following general formula: 0.04.times.10.sup.-19 .ltoreq.Log(.gamma.2/.gamma.1)/.nu..ltoreq.0.20.

Abstract: A curable rubber composition comprises of a silicone rubber (A) and an ethylene-.alpha.-olefin-polyene amorphous copolymer (B) containing as the polyene component a norbornene compound having at least one kind of vinyl terminal group represented by 5-vinyl-2-norbornene or 5-methylene-2-norbornene. The rubber composition is speedily cured, if said components (A) and (B) are mixed by the A/B mixing ratio of 98/2-2/98 (% by weight) and kneaded in the presence of an organic peroxide. A vulcanizate rubber excelling in mechanical strength, water resistance and thermal aging resistance can be manufactured from said composition, since its crosslink density can be enhanced without impairing processing properties. Additionally, said composition entails reduced mold fouling phenomenon in the molding operation. Vulcanizate rubber thereby obtained can be advantageously used as industrial parts and electric parts.

Abstract: A heat-resistant rubber composition of the invention is a vulcanizable composition comprising a specific ethylene-.alpha.-olefin-nonconjugated polyene copolymer rubber (A) and an organic peroxide (B). This heat-resistant composition has high crosslinking efficiency given by the organic peroxide and high modulus, and can provide a vulcanized rubber molded product of excellent resistance to environmental deterioration such as thermal aging resistance. The other heat-resistant rubber composition of the invention is a vulcanizable composition comprising 100 parts by weight of a specific ethylene-.alpha.-olefin-nonconjugated polyene copolymer rubber (A) composed of ethylene, an .alpha.-olefin or 3 to 20 carbon atoms and a nonconjugated polyene which is a vinyl end group-containing norbornene compound, 0.2 to 5 parts by weight of an amine type anti-aging agent (C) and/or a hindered phenol type anti-aging agent (D), 1 to 10 parts by weight of a sulfur type anti-aging agent (E) and an organic peroxide (B).

Abstract: Disclosed is an ethylene copolymer rubber which is a random copolymer rubber of (a) ethylene, (b) an .alpha.-olefin of 3 to 20 carbon atoms, (c) a nonconjugated polyene containing, in one molecule, one carbon-to-carbon double bond polymerizable by a metallocene catalyst among carbon-to-carbon double bonds, and (d) a nonconjugated polyene containing, in one molecule, two carbon-to-carbon double bonds polymerizable by the metallocene catalyst among carbon-to-carbon double bonds. The ethylene copolymer rubber has excellent moldability, high vulcanization rate, good mechanical properties such as high vulcanization strength, excellent low-temperature flexibility and thermal aging resistance. Also disclosed is a process for preparing the ethylene copolymer rubber with high activity, high conversion ratio of .alpha.-olefin and high random copolymerizability.

Abstract: A heat-resistant rubber composition of the invention is a vulcanizable composition comprising a specific ethylene-&agr;-olefin-nonconjugated polyene copolymer rubber (A) and an organic peroxide (B). This heat-resistant composition has high crosslinking efficiency given by the organic peroxide and high modulus, and can provide a vulcanized rubber molded product of excellent resistance to environmental deterioration such as thermal aging resistance. The other heat-resistant rubber composition of the invention is a vulcanizable composition comprising 100 parts by weight of a specific ethylene-&agr;-olefin-nonconjugated polyene copolymer rubber (A) composed of ethylene, an &agr;-olefin or 3 to 20 carbon atoms and a nonconjugated polyene which is a vinyl end group-containing norbornene compound, 0.2 to 5 parts by weight of an amine type anti-aging agent (C) and/or a hindered phenol type anti-aging agent (D), 1 to 10 parts by weight of a sulfur type anti-aging agent (E) and an organic peroxide (B).