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: 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: This invention relates to a composition comprising (A) an ethylene-&agr;-olefin having 3 to 20 carbon atoms-non-conjugated polyene copolymer, (B) a specific fine-powdered silicic acid and/or a silicate having a specific surface area of 5 to 500 m2/g (BET adsorption amount: ISO 5794/1, Annex D), (C) at least one kind of &agr;,&bgr;-unsaturated carboxylic acid metal salts, (D) an organic peroxide, further optionally (E) one antioxidant selected from sulfur-containing antioxidants, phenolic antioxidants and amine antioxidants, and/or (F) sulfur, and this invention relates to a rubber product obtainable by crosslinking the above composition.

Abstract: A kneading status evaluation method for a rubber composition containing at least a rubber and a filler comprises the steps of a complex modulus measurement step (1) in which a complex modulus E*(a) at a given strain &egr; a and a complex modulus E*(b) at a given strain &egr; b differing from the strain &egr; a of the rubber composition (I) are measured, a filler dispersion index calculation step (2) in which a filler dispersion index (N) of the rubber composition (I) is calculated with complex elastic moduli E*(a) and E*(b) obtained in the previous step (1) according to the equation shown below, and a comparison step (3) to compare a predetermined target filler dispersion index (R) with the filler dispersion index (N) calculated in the previous step (2), and/or a complex viscosity coefficient measurement step (5) to measure a complex viscosity coefficient &eegr;* of the rubber composition (I) under at least two different temperatures, and a kneading status monitor index calculation step (6) to calculate a kne

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: This invention relates to a rubber composition comprising an ethylene-&agr;-olefin having 3 to 12 carbon atoms-non-conjugated polyene copolymer rubber, a specific alkoxysilane compound, a specific polysiloxane and a specific fine-powdered silicic acid and/or silicate, to vulcanizing method of the rubber composition, and to a rubber product obtainable by the vulcanizing method.

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 relates to an ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber comprising ethylene, an &agr;-olefin having 3 to 20 carbon atoms and a non-conjugated polyene, characterized in that: (i) the intrinsic viscosity [&eegr;] as measured in decalin solvent at 135° C. is 1.5 to 5.0 dl/g; (ii) the g&eegr;* or g′ value is 0.6 to 0.9; (iii) the Mw/Mn is 3.0 to 50; (iv) the iodine value is 10 to 40; (v) the molar ratio of ethylene to the &agr;-olefin having 3 to 20 carbon atoms is 40/60 to 95/5; and (vi) the intensity ratio D of T&agr;&bgr; to T&agr;&agr; in 13C-NMR spectrum (T&agr;&bgr;/T&agr;&agr;) is 0.5 or less, as well as to a rubber composition for sealing using said copolymer rubber, a molded rubber part for sealing, and a process for preparing said molded part.

Abstract: The present invention relates to an olefinic thermoplastic elastomer composition which comprises a crystalline polyolefin resin (A), an ethylene-&agr;-olefin-non-conjugated polyene copolymer rubber (B) and at least on rubber (C) selected from polyisobutylene, butyl rubber and a propylene-ethylene copolymer rubber having a propylene content of 50 mol % or more or an ethylene-&agr;-olefin copolymer (D) having a density of 0.870 to 0.

Abstract: A propylene polymer composition comprising a propylene polymer prepared by using a zirconocene catalyst having two aryl-substituted indenyl group and having a melt flow rate (MFR) of 0.01 to 30 g/10 min and a second propylene polymer prepared by using a zirconocene catalyst having a melt flow rate (MFR) of 30 to 1,000 g/l 0 min and, if desired, a soft polymer, a ratio of the MFR of the second propylene polymer to the MFR of the second propylene polymer being not less than 30. These propylene polymer compositions are excellent in heat resistance, mechanical strength, tensile elongation at break, etc., and hence they can be favorably used for various structural materials such as those of automobile and electrical appliances, daily necessaries, various films and sheets.

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 novel and useful linear triene compound represented by the following formula (1) is co-polymerized with an &agr;-olefin to obtain an ethylenically unsaturated copolymer which is superior in weather-ability, heat resitance and fastness to ozone, together with superior scorch stability and vulcanizability at high velocity in which R1, R2, R3, R4, R5 and R6 stand each, independently of each other, for hydrogen atom or an alkyl having 1-3 carbon atoms, R7 represents an alkyl having 1-3 carbon atoms and n is an integer of 0-5, with the proviso that each of R4s or of R5s may be identical with or different from each other, respectively, when n is 2 or greater.

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 propylene polymer composition is prepared by mixing a first propylene polymer prepared using an olefin polymerization catalyst containing a specific metallocene catalyst component of formula (I), e.g., rac-dimethylsilylene-bis{1-(2-ethyl-4-phenylindenyl)} zirconium dichloride, and an organoaluminum-oxy cocatalyst, with a second propylene polymer component. The compositions are excellent in heat resistance, mechanical strength, tensile elongation at break, and other properties and can be used to produce various structural materials, sheets and films.

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 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: The chain polyene-group containing norbornene compound of the invention is represented by the formula [I]: ##STR1## wherein n is an integer of 1 to 5, R.sup.1 is an alkyl group of 1 to 5 carbon atoms, and R.sup.2 and R.sup.3 are each independently a hydrogen atom or an alkyl group of 1 to 5 carbon atoms.The unsaturated ethylene copolymer of the invention is a random copolymer of 30 to 92% by mol of (i) ethylene units, 6 to 70% by mol of (ii) specific .alpha.-olefin units and 0.1 to 30% by mol of (iii) units derived from the norbornene compound [I], where the molar ratio of (i)/(ii) is in the range of 40/60 to 92/8 and the unit (iii) is represented by the specific formula, and has an intrinsic viscosity [.eta.] of 0.05 to 10 dl/g.The novel unsaturated ethylene copolymer is excellent in weathering resistance, heat resistance and ozone resistance and has a high vulcanizing rate.

Abstract: A process for preparing a propylene polymer composition having excellent rigidity, heat resistance and impact resistance, the process comprising conducting multistage polymerization including a step (a) for preparing a propylene (co)polymer (a), a step (b) for preparing a propylene-olefin copolymer (b) and a step (c) for preparing an ethylene-olefin copolymer (c) in the presence of (A) a transition metal compound and (B) a compound activating the transition metal compound (A), in which the steps (a), (b) and (c) may be carried out in any order, each of the second and subsequent stage polymerizations is carried out in the presence of a polymer or polymers obtained by the preceding stage or stages, respectively, and the resulting propylene polymer composition contains the propylene (co)polymer (a) in an amount of 20 to 90% by weight, the propylene-olefin copolymer (b) in an amount of 5 to 75% by weight and the ethylene-olefin copolymer (c) in an amount of 5 to 75% by weight, and has MFR, as measured at 230.

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).