Abstract: An ?-olefin/non-conjugated cyclic polyene copolymer (A) includes structural units (I) derived from an ?-olefin and structural units (H) derived from a vinyl group-containing cyclic olefin. The copolymer has a molecular weight distribution (Mw/Mn) of not more than 2.7 and is amorphous or low crystalline with a crystalline heat of fusion (?H) of less than 90 kJ/kg. The copolymer is efficiently produced using a specific transition metal catalyst that has a ligand with a phenoxyimine skeleton. The copolymer of the invention has a narrower molecular weight distribution and a higher content of vinyl groups as compared with existing copolymers. The copolymer can then give crosslinked products having excellent tensile properties. The copolymer is also used as a plasticizer for polymers such as rubbers, and provides excellent processability and superior mechanical strength and rubber elasticity of crosslinked products.

Abstract: Provided is a rubber composition which can give a tire excellent in braking performance and fuel consumption and which is excellent in mechanical strength and fatigue resistance, and a use thereof. The rubber composition of the present invention contains a (A) 60 to 0.1 parts by weight of a nonconjugated polyene copolymer, which is a random copolymer containing 96 to 70 mol % of the structural units derived from ?-olefin (A1) and 4 to 30 mol % of the structural units derived from a nonconjugated polyene (A2), and has a glass transition temperature (Tg) of ?25 to 20° C., (B) 40 to 99.9 parts by weight of a diene rubber and (C) at least one selected from the group consisting of specific polymers.

Abstract: Disclosed are a conjugated polyene copolymer comprising a random copolymer having structural units derived from ?-olefin (A1) of 2 to 20 carbon atoms and structural units derived from nonconjugated polyene (A2), said nonconjugated polyene copolymer having a glass transition temperature (Tg) of ?25 to 20 ? and Mooney viscosity of [ML(1+4)100?] of 5 to 190; a rubber composition comprising the nonconjugated polyene copolymer and a diene-based rubber (B); a modifier for tires comprising the copolymer; a rubber material for tires comprising the rubber composition; a tire tread obtained from the rubber material for tires; and a tire having the tire tread.

Abstract: A process for producing a rubber composition containing a nonconjugated polyene copolymer (A), a softener (B) and a diene rubber (C), comprising: a step of mixing a copolymer composition (I), said copolymer composition (I) comprising 100 parts by weight of a nonconjugated polyene copolymer (A), said nonconjugated polyene copolymer (A) being a random copolymer containing 96 to 70 mol % of the structural units derived from ?-olefin (A1) and 4 to 30 mol % of the structural units derived from nonconjugated polyene (A2) and having a glass transition temperature (Tg) of ?25 to 20° C., and 1 to 100 parts by weight of the softener (B); the diene rubber (C); and optionally further the softener (B). A tire tread using the rubber composition and a tire having the tire tread.

Abstract: It is an object of the present invention to provide a non-conjugated cyclic diene and a non-conjugated cyclic diene composition which enable the production of a polymer based on non-conjugated cyclic diene which makes it possible to produce a (co)polymer at a high degree of polymerization activity, and a method of producing a polymer based on non-conjugated cyclic diene which makes it possible to produce a (co)polymer at a high degree of polymerization activity. A non-conjugated cyclic diene is used which meets at least one of the following requirements: (1) it contains a compound having a seven-membered cyclic triene hydrocarbon structure in a specific amount or less and (2) it contains a conjugated polyene compound having an eight-membered bicyclic hydrocarbon structure in a specific amount.

Abstract: A silicon-containing olefin copolymer is provided which comprises (a) a constituent unit derived from —CH2—CH2— such as ethylene, (b) a constituent unit derived from —CH2—CHR— where R is a hydrocarbon group of 1 to 18 carbon atoms, and (c) a constituent unit containing a specific silicon-containing group. A silicon-containing olefin copolymer is also provided which is obtainable by co-polymerizing ethylene, an a-olefin of 3 to 20 carbon atoms and a specific silicon-containing ethylene monomer.

Abstract: The invention has an object of providing a process for producing an ethylene/?-olefin/non-conjugated polyene copolymer with good polymerization activity and high conversion of non-conjugated polyene. The invention achieves the object by providing a process for producing an ethylene/?-olefin/non-conjugated polyene copolymer that comprises copolymerizing ethylene, an ?-olefin and a non-conjugated polyene in a hydrocarbon solvent with use of a transition metal compound catalyst, and removing the unreacted monomers and the hydrocarbon solvent from the copolymer solution without removing the catalyst residue, wherein the copolymerization is carried out at a polymerization temperature of 100° C. or above and a polymerization pressure of 2.7 MPa or above in a manner such that the non-conjugated polyene concentration in the polymerization solution is less than the maximum non-conjugated polyene concentration Cmax (mol/L) indicated below: Cmax=0.050 (mol/L) when the copolymer has an iodine value (IV) of 9.

Abstract: It is an object of the present invention to provide a non-conjugated cyclic diene and a non-conjugated cyclic diene composition which enable the production of a polymer based on non-conjugated cyclic diene which makes it possible to produce a (co)polymer at a high degree of polymerization activity, and a method of producing a polymer based on non-conjugated cyclic diene which makes it possible to produce a (co)polymer at a high degree of polymerization activity. A non-conjugated cyclic diene is used which meets at least one of the following requirements: (1) it contains a compound having a seven-membered cyclic triene hydrocarbon structure in a specific amount or less and (2) it contains a conjugated polyene compound having an eight-membered bicyclic hydrocarbon structure in a specific amount.

Abstract: An ethylene copolymer is provided which is a copolymer of ethylene and an ?-olefin of 3 to 20 carbon atoms and has the following properties: (a) the melt index (MI2) at 190° C. under a load of 2.16 kg is in the range of 0.0001 to 1000 g/10 min, (b) the density is not more than 0.899 g/cm3, (c) the relationship between a vinyl group amount and MI2 of the polymer satisfies the following expression: (vinyl group amount: number of vinyl groups/1000 carbon atoms)?0.004509+0.000815×log(MI2), and (d) the relationship between a vinylidene group amount and MI2 of the polymer satisfies the following expression: (vinylidene group amount: number of vinylidene groups/1000 carbon atoms)?0.013528+0.002445×log(MI2).

Abstract: The first silicon-containing olefin copolymer of the present invention comprises (a) a constituent unit derived from —CH2—CH2—, (b) a constituent unit derived from —CH2—CHR— [R is a hydrocarbon group of 1 to 18 carbon atoms], and (c) a constituent unit containing a specific silicon-containing group, and has a molar ratio [(a)/(b)] of the constituent units (a) to the constituent units (b) of from 99/1 to 30/70, a content of the constituent unit (c) of from 0.1 to 10 mol % based on 100 mol % of the total amounts of the constituent units (a), (b) and (c), and a branching index of not less than 0.70. The second silicon-containing olefin copolymer of the present invention is obtainable by copolymerizing ethylene, an ?-olefin of 3 to 20 carbon atoms and a specific silicon-containing ethylene monomer, and has a molar ratio of ethylene to ?-olefin of from 99/1 to 30/70, an intrinsic viscosity, as measured in decalin at 135° C., of from 0.1 to 10 dl/g, a content of the ethylene monomer of from 0.

Abstract: A tire provided with a tire tread made from a rubber composition comprising (A) a random copolymer based on non-conjugated cyclic polyene comprising structural units originated from one or more &agr;-olefins (A1) and originated from one or more non-conjugated cyclic polyene (A2), the said random copolymer having a content of the structural unit(s) originated from one or more &agr;-olefins (A1) in the range of 93 to 70 mole %; a content of the structural unit originated from one or more non-conjugated cyclic polyene (A2) in the range of 7 to 30 mole %; an intrinsic viscosity [&eegr;], determined in decalin at 135° C., in the range of 0.01 to 20 dl/g; a glass transition temperature (Tg) of not higher than 40° C.; and an iodine value in the range of 50 to 150, and (B) a rubber based on diene, in a weight proportion of {the random copolymer based on non-conjugated cyclic polyene (A)} versus {the rubber based on diene (B)} in the range from 60/40 to 0.1/99.

Abstract: The ethylene copolymer of the invention is a copolymer (A-1) of ethylene and an &agr;-olefin of 3 to 20 carbon atoms and has the following properties:

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 process for producing an aromatic polyamide which comprises:(a) a dicarboxylic acid component which consists of 30-100 mol % of terephthalic acid and optionally 0-70 mol % of at least one dicarboxylic acid other than terephthalic acid, and(b) a diamine component which consists of 50-100 mol % of an aliphatic alkylenediamine of 4-25 carbons and optionally 0-50 mol % of at least one alicyclic diamine of 3-25 carbons, said process comprising a first step of performing melt reaction of said dicarboxylic acid with said diamine, thereby giving a low molecular weight condensate having an intrinsic viscosity [.eta.] of 0.05-0.6 dl/g, a second step of subjecting it to solid phase polymerization, thereby giving an aromatic polyamide precursor having an intrinsic viscosity [.eta.] of 0.5-1.0 dl/g, and a third step of subjecting it to melt polymerization, thereby giving an aromatic polyamide having a desired intrinsic viscosity [.eta.] of 0.8-2.5 dl/g.

Abstract: The semiaromatic polyamide of the invention comprises 40 to 90% by mol of (A) recurring units derived from terephthalic acid and an aliphatic diamine of 4 to 12 carbon atoms, 0 to 50% by mol of (B) recurring units derived from isophthalic acid and an aliphatic diamine of 4 to 12 carbon atoms, 0 to 60% by mol of (C) recurring units derived from an aliphatic dicarboxylic acid of 4 to 18 carbon atoms and an aliphatic diamine of 4 to 12 carbon atoms and 0 to 50% by mol of (D) recurring units derived from a lactam or an aminocarboxylic acid of 6 to 20 carbon atoms, and has a content of boiling water-soluble components (MO components) of not more than 0.25% by weight. The semiaromatic polyamide has a low content of the MO components, so that mold contamination hardly brought about in the molding process, and also molded articles of good heat resistance can be produced.