Zeon Corporation

Kyoto University

Shingo Okuno

Yasuo Tsunogae

Hiroyuki Nitadori

Shigetaka Hayano

Fumiaki Bando

Mitsuo Sawamoto

Makoto Ouchi

Naoaki Kuramoto

Takeshi Sugimura

A ring-opened copolymer including structural units derived from a norbornene compound having a specific structure and structural units derived from a monocyclic olefin, wherein the proportion of the structural units derived from a norbornene compound is 25 to 90 wt % and the proportion of the structural units derived from a monocyclic olefin is 10 to 75 wt % relative to the total repeating structural units in the ring-opened copolymer, the weight average molecular weight of the ring-opened copolymer is 100,000 to 1,000,000, and the cis/trans ratio of the ring-opened copolymer is 0/100 to 50/50.

Ring-opened copolymer

A ring-opened copolymer composition has a ring-opened copolymer containing structural unit derived from a norbornene compound represented by general formula (1) below and structural unit derived from a monocyclic olefin, wherein a content of a norbornene compound represented by general formula (1) is 1 ppm by weight or more and 1000 ppm by weight or less based on the ring-opened copolymer, wherein Rto Rare each a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom, and Rand Rmay be bonded to each other to form a ring, and 'm' is 0 or 1.

Ring-opening copolymer composition

A crosslinkable composition containing: a liquid monocyclic olefin ring-opened polymer (A) having a reactive group at a polymer chain end thereof and a weight-average molecular weight (Mw) of 1,000 to 50,000; and a crosslinkable compound (B) having, in the molecule, two or more functional groups reactive with the reactive group at the polymer chain end of the monocyclic olefin ring-opened polymer (A).

Crosslinkable composition and crosslinked product

A rubber composition that contains 0.1 to 50 parts by weight of an organic peroxide with respect to 100 parts by weight of a cyclopentene ring-opening polymer.

Rubber composition and crosslinked rubber

A cyclopentene ring-opening copolymer having a branch structure contains a structure in which at least four cyclopentene ring-opening polymer chains are linked via a branch-structural unit. At least part of the cyclopentene ring-opening polymer chains is terminally modified.

Cyclopentene ring-opening copolymer and method of producing the same

A rubber composition containing: a solid rubber (A) having a weight-average molecular weight (Mw) of 100,000 or more; and a liquid monocyclic olefin ring-opened polymer (B) having a weight-average molecular weight (Mw) of 1,000 to 50,000, wherein a proportion of the liquid monocyclic olefin ring-opened polymer (B) is 1 to 100 parts by weight per 100 parts by weight of the solid rubber (A).

Rubber composition and rubber crosslinked product

A crosslinked rubber is produced by crosslinking a polymer composition containing 100 parts by weight of a rubber component containing a cyclopentene ring-opening polymer and 20 to 200 parts by weight of carbon black, wherein, when the crosslinked rubber is subjected to an ozone treatment in which the rubber is maintained at 40&#xb0; C. and an ozone concentration of 50 pphm for 144 hours under a 20% tensile strain, the crosslinked rubber shows a rate of change in tensile strength before and after ozone treatment of within &#xb1;70%.

Crosslinked rubber

A liquid cyclopentene ring-opened polymer having a weight average molecular weight (Mw) of 1,000 to 50,000 and a cis double content of 55% or more in repeating units.

Liquid cyclopentene ring-opened polymer, rubber composition, and rubber crosslinked product

A crosslinked rubber is a member for use in an environment at &#x2212;10&#xb0; C. or less produced by crosslinking a polymer composition containing 20 to 200 parts by weight of carbon black with respect to 100 parts by weight of a rubber component containing a monocyclic olefin ring-opening polymer having a proportion of cis bond of a structural unit derived from a monocyclic olefin of 45 to 95%.

Use of crosslinked rubber

Provided is a rubber composition for a tire containing a rubber component including 15 to 55 wt % of an end modified group-containing cycloolefin ring-opening polymer having a glass transition temperature of &#x2212;120 to &#x2212;90&#xb0; C. and 45 to 85 wt % of an end modified group-containing solution polymerized conjugated diene polymer having a glass transition temperature of &#x2212;60 to &#x2212;10&#xb0; C. and having an aromatic vinyl monomer unit content ratio of more than 30 wt % and 50 wt % or less, a silica, and a silane coupling agent including a monosulfide group and/or a thiol group, wherein the content of the silica with respect to 100 parts by weight of the rubber component is 30 to 200 parts by weight, and the content of the silane coupling agent including a monosulfide group and/or a thiol group with respect to 100 parts by weight of the silica is 0.3 to 20 parts by weight.

Rubber composition for tire

A cycloolefin rubber having a weight average molecular weight of 100,000 to 800,000, having a silyl group at the polymer chain end, and containing a fatty acid ester of a polyvalent alcohol. A cycloolefin rubber excellent in processability at the time of blending and kneading and excellent in low heat buildup property can be provided.

Cycloolefin rubber and method of production of same and rubber composition, cross-linked rubber, and tire

Conjugated diene polymer comprising at least a conjugated diene monomer unit, the conjugated diene polymer has a number-average molecular weight (Mn) in terms of polystyrene of 1,000 to 1,000,000, a ratio (Mw/Mn) of a weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of lower than 2.0 and the polymer bears a halogen atom at a terminal of the polymer chain. Method for producing the conjugated diene polymer comprises subjecting a monomer containing at least a conjugated diene to living radical polymerization using a polymerization initiator comprising a halogenocyclopentadienyl triorganophosphine &#x3b7;-olefin ruthenium complex represented by formula (6) (and an organic halide. 

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Tokyo, Japan

Shingo Okuno