Abstract: An olefin thermoplastic elastomer composition comprises a crystalline polyolefin resin (A) and an ethylene/&agr;-olefin/nonconjugated polyene copolymer rubber (B), and optionally a softener (C) and/or an inorganic filler (D), in a specific ratio. The copolymer rubber (B) is prepared by the use of a metallocene catalyst and comprises ethylene, an &agr;-olefin of 3 to 20 carbon atoms and a nonconjugated polyene. This composition ca provide molded products of more excellent tensile strength, elongation at break, elastomeric properties (elongation set, permanent compression set, etc.), heat resistance and low-temperature properties than the conventional non-crosslinked olefin thermoplastic elastomers, even if the composition is in the non-crosslinked form. The composition in the partially or completely crosslinked form can provided molded products of more excellent low-temperature properties, tensile strength, elongation at break and elastomeric properties than the conventional vulcanized rubbers.

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: An olefin thermoplastic elastomer composition comprises a crystalline polyolefin resin (A) and an ethylene/&agr;-olefin/nonconjugated polyene copolymer rubber (B), and optionally a softener (C) and/or an inorganic filler (D), in a specific ratio. The copolymer rubber (B) is prepared by the use of a metallocene catalyst and comprises ethylene, an &agr;-olefin of 3 to 20 carbon atoms and a nonconjugated polyene. This composition ca provide molded products of more excellent tensile strength, elongation at break, elastomeric properties (elongation set, permanent compression set, etc.), heat resistance and low-temperature properties than the conventional non-crosslinked olefin thermoplastic elastomers, even if the composition is in the non-crosslinked form. The composition in the partially or completely crosslinked form can provided molded products of more excellent low-temperature properties, tensile strength, elongation at break and elastomeric properties than the conventional vulcanized rubbers.

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 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 rubber composition useful as a tire side wall or tire tread is formed from an unsaturated olefin copolymer (A) or (A′) and diene rubber (B). Copolymers (A) and (A′) are each obtained from (i) ethylene, (ii) aromatic vinyl compound, (iii) non-conjugated polyene, and, optionally (iv) alpha-olefin having at least 3 carbon atoms. When used in forming a tire side wall, copolymer (A) has a molar ratio of (i)/(iv) from 100/0 to 40/60; molar ratio of [((i)+(iv))/(ii)] from 98/2 to 60/40; an intrinsic viscosity, measured in decalin, at 135° C., from 1.0 to 6.0 dl/g; and iodine value from 10 to 50. For use in tire tread, copolymer (A′), has a molar ratio (i)/(iv) from 100/0 to 40/60; molar ratio [((i)+(iv)):(ii)] from 99/1 to 85/15. The weight ratio (A′)/(B) is from 1/99 to 50/50. The compositions for tire side wall are characterized by excellent strength properties and bending fatigue resistance and low fuel consumption.

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 vulcanizable rubber composition comprising a blend which is prepared by micro-dispersing a polyolefin resin (B) in an ethylene-.alpha.-olefin-nonconjugated polyene copolymer rubber (A) comprising ethylene, a C.sub.3 -C.sub.20 .alpha.-olefin and a nonconjugated polyene in a molten state and in which the mean diameter of dispersed particles of the polyolefin resin (B) is 2 .mu.m or below and the (B) to (A) weight ratio ranges from 5/95 to 50/50. The micro-dispersion of a polyolefin resin (B) can easily be attained by kneading the components (A) and (B) together with compounding ingredients (such as reinforcement, filler, softener, vulcanization accelerator, vulcanizing agent and so on) in a rubber kneader, through the resin (B) is essentially difficult of micro-dispersion. Further, the composition enables the provision of rubber articles having a high and constant quality at a low cost, because the resin (B) can well be dispersed by conventional rubber kneaders in a short time without fail.

Abstract: Disclosed is a foam processable rubber composition which comprises an ethylene/.alpha.-olefin of 3 to 20 carbon atoms/non-conjugated polyene copolymer rubber (A), a crystalline polyolefin resin (B) having a melting point of 100 to 150.degree. C. and a foaming agent (C), in specific proportions. The copolymer rubber (A) has an ethylene/.alpha.-olefin molar ratio of 60/40 to 80/20, an intrinsic viscosity (.eta.), as measured in decalin at 135.degree. C., of 0.7 to 2 dl/g, and an iodine value of 10 to 50. A vulcanized rubber foam-molded product can be obtained by vulcanizing and foaming the rubber composition. The rubber composition can provide vulcanized rubber foam-molded products having excellent vulcanization properties such as weathering resistance, heat resistance, ozone resistance and tear strength. Besides, the rubber composition exhibits excellent precision moldability and productivity of vulcanized rubber foam-molded products in transfer molding, injection molding and cast molding.

Abstract: A terpolymer rubber prepared from ethylene, .alpha.-olefin having 3 to 20 carbon atoms and branched chain polyene of the formula ##STR1## wherein R.sup.1 represents C.sub.1 -C.sub.5 alkyl, and R.sup.2 and R.sup.3 represent hydrogen atom or C.sub.1 -C.sub.5 alkyl, such as, for example, 6,7-dimethyl-4-ethylidene-1,6-octadiene, 6,7-dimethyl-4-ethylidene-1,6-nonadiene, and 9-methyl-4-ethylidene-1,8-decadiene; when added to a rubber (diene rubber, nitrile rubber or random copolymer rubber from ethylene, C.sub.3 -C.sub.20 .alpha.-olefin, and optionally a nonconjugated diene) provides curable rubber compositions having rapid vulcanization rates, for example, as lows as about 7 to 10 seconds. The diene rubber compositions also have excellent resistances to weather,ozone and heat aging while maintaining excellent mechanical strength characteristics. The nitrile rubber compositions also have excellent oil resistance.

Abstract: The ethylene/.alpha.-olefin/nonconjugated polyene copolymer rubber composition of the present invention comprises in specified proportions a crystalline polyolefin resin (A) and an ethylene/.alpha.-olefin/nonconjugated polyene copolymer rubber (B) composed of ethylene, an .alpha.-olefin having 3 to 20 carbon atoms and a specific branched chain polyene compound. The molar ratio of ethylene units to .alpha.-olefin units, iodine value and intrinsic viscosity ?.eta.! of the ethylene/.alpha.-olefin/nonconjugated polyene copolymer rubber (B) are within respective specified ranges. This rubber composition is excellent in low temperature properties. When the above olefinic thermoplastic elastomer composition is partially or entirely crosslinked, a molding can be provided which is superior to the conventional vulcanized rubbers in low temperature properties, tensile strength, elongation at break and rubber properties.

Abstract: Disclosed is a process for preparing an ethylene-.alpha.-olefin-nonconjugated polyene random copolymer comprising random copolymerizing (a) ethylene, (b) an .alpha.-olefin of 3 or more carbon atoms and (c) a nonconjugated polyene in the presence of a metallocene catalyst containing a specific metallocene compound. The ethylene-.alpha.-olefin-nonconjugated polyene random copolymer prepared by the process has such properties that (i) the copolymer contains units derived from ethylene (a) and units derived from the .alpha.-olefin of 3 or more carbon atoms (b) in a molar ratio of 40/60 to 95/5 ?(a)/(b)!, (ii) the iodine value is 1 to 50, (iii) the intrinsic viscosity (.eta.) is more than 0.1 dl/g and less than 8.0 10 dl/g, (iv) the intensity ratio D of T.alpha..beta. to T.alpha..alpha. in the .sup.13 C-NMR spectrum, T.alpha..beta./T.alpha..alpha., is not more than 0.5, (v) the B value is 1.00 to 1.50, (vi) the glass transition temperature Tg is not higher than -50.degree. C., and (vii) the ratio g.eta.

Abstract: The ethylene/.alpha.-olefin/nonconjugated polyene copolymer rubber composition of the present invention comprises in specified proportions a crystalline polyolefin resin (A) and an ethylene/.alpha.-olefin/nonconjugated polyene copolymer rubber (B) composed of ethylene, an .alpha.-olefin having 3 to 20 carbon atoms and a specific branched chain polyene compound. The molar ratio of ethylene units to .alpha.-olefin units, iodine value and intrinsic viscosity ?.eta.! of the ethylene/.alpha.-olefin/nonconjugated polyene copolymer rubber (B) are within respective specified ranges. This rubber composition is excellent in low temperature properties. When the above olefinic thermoplastic elastomer composition is partially or entirely crosslinked, a molding can be provided which is superior to the conventional vulcanized rubbers in low temperature properties, tensile strength, elongation at break and rubber properties.

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: Disclosed is a process for preparing an ethylene-.alpha.-olefin-nonconjugated polyene random copolymer comprising random copolymerizing (a) ethylene, (b) an .alpha.-olefin of 3 or more carbon atoms and (c) a nonconjugated polyene in the presence of a metallocene catalyst containing a specific metallocene compound. The ethylene-.alpha.-olefin-nonconjugated polyene random copolymer prepared by the process has such properties that (i) the copolymer contains units derived from ethylene (a) and units derived from the .alpha.-olefin of 3 or more carbon atoms (b) in a molar ratio of 40/60 to 95/5 ?(a)/(b)!, (ii) the iodine value is 1 to 50, (iii) the intrinsic viscosity (.eta.) is more than 0.1 dl/g and less than 8.0 10 dl/g, (iv) the intensity ratio D of T.alpha..beta. to T.alpha..alpha. in the .sup.13 C-NMR spectrum, T.alpha..beta./T.alpha..alpha., is not more than 0.5, (v) the B value is 1.00 to 1.50, (vi) the glass transition temperature Tg is not higher than -50.degree. C., and (vii) the ratio g.eta.

Abstract: Disclosed is an ethylene-.alpha.-olefin-nonconjugated polyene random copolymer which is a random copolymer of (a) ethylene, (b) an .alpha.-olefin of 3 or more carbon atoms and (c) a nonconjugated polyene, and has such properties that (i) the copolymer contains (a) units derived from ethylene and (b) units derived from the .alpha.-olefin of 3 or more carbon atoms in a molar ratio of 40/60 to 95/5 ((a)/(b)), (ii) the iodine value is in the range of 1 to 50, (iii) the intrinsic viscosity (.eta.), as measured in decahydronaphthalene at 135.degree. C., is in the range of 0.1 to 8.0 dl/g, and (iv) the ratio g.eta.* of the intrinsic viscosity (.eta.) of the copolymer defined above to the intrinsic viscosity (.eta.).sub.blank of a linear ethylene-propylene copolymer having the same weight-average molecular weight as the ethylene-.alpha.-olefin-nonconjugated polyene random copolymer and having an ethylene content of 70% by mol, (.eta.)/(.eta.).sub.blank, is in the range of 0.2 to 0.

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).