Japan Synthetic Rubber Co., Ltd.

Jsr Corporation

Nobuyuki Sakabe

Toshio Miyabayashi

Yasuhiko Takemura

Hiroji Enyo

Kenzo Ohkita

Shinichiro Zen

Yoshiyuki Udagawa

Kenji Hasegawa

Noboru Oshima

Fumio Tsutsumi

Akihiko Morikawa

Katsutoshi Sawada

Koei Komatsu

Tarou Kanamori

Kouji Kawahara

Yooichiroh Maruyama

Toshio Ohhara

Yuuichi Hashiguchi

Hiroshi Ise

Shigeyuki Nishiyama

Akira Kogure

A process for manufacturing a cycloolefin addition polymer includes polymerizing monomers containing a cycloolefin compound using a catalyst containing a nickel compound or a palladium compound by addition polymerization in the presence of a molecular weight controlling agent in two steps, that is a step of a initiating the polymerization reaction using the monomers in an amount of not more than 80 wt % of the total monomers and a step of supplying the remaining monomers to the reaction system during the polymerization reaction. A cycloolefin addition polymer with a uniform quality, having a narrow molecular weight distribution and a controlled molecular weight, and excellently balanced processability and mechanical strength can be obtained at a high polymerization conversion rate using the process. The process can be operated at a highly controlled polymerization temperature, and is thus suitable for industrially manufacturing a cycloolefin addition polymer.

Process for manufacturing cycloolefin addition polymer

Composition of cyclic olefin addition copolymer and cross-linked material

An ethylene copolymer rubber composition which comprises an ethylene copolymer rubber and at least one member selected from the group consisting of a vulcanizing agent and a cross-linking agent and optionally a conjugated diene rubber, said ethylene copolymer rubber being composed of ethylene, an .alpha.-olefin having 3 to 12 carbon atoms, a non-conjugated diene represented by the following structural formula (I): ##STR1## wherein R.sup.1 and R.sup.2 represent independently hydrogen atoms or alkyl groups having 1 to 8 carbon atoms, R.sup.3 represents an alkyl group having 1 to 8 carbon atoms, and n is an integer of 2 to 10, and an .alpha.,.omega.-diene represented by the following structural formula (II) :

Ethylene copolymer rubber composition

A hydrogenated copolymer rubber which is a hydrogenation product of a random copolymer rubber consisting of:

Hydrogenated copolymer rubber, rubber composition comprising said rubber

A substantially random, linear vinylidene fluoride-acrylic acid ester copolymer comprising:

Vinylidene fluoride-acrylic acid ester copolymer, process for producing

A multi-component copolymer rubber consisting essentially of (A) 20 to 69.5% by weight of a cyano-substituted alkyl (meth)acrylate, (B) 30 to 79.5% by weight of an alkyl acrylate, (C) 0.5 to 10% by weight of a crosslinkable monomer and (D) 0 to 10% by weight of other ethylenically unsaturated monomer copolymerizable with (A), (B) and (C), excels in heat resistance, ozone resistance, sour gasoline resistance and sour gasohol resistance. There properties of said multi-component copolymer rubber can further be improved by incorporating into the copolymer rubber a crosslinking agent, a metal salt, a vinylidene fluoride polymer, a vinyl chloride resin or other multi-component copolymer rubber.

Multi-component copolymer rubber, a process for producing the same and a

A multi-component copolymer rubber consisting essentially of (A) 20 to 69.5% by weight of a cyano-substituted alkyl (meth)acrylate, (B) 30 to 79.5% by weight of an alkyl acrylate, (C) 0.5 to 10% by weight of a crosslinkable monomer and (D) 0 to 10% by weight of other ethylenically unsaturated monomer copolymerizable with (A), (B) and (C), excels in heat resistance, ozone resistance, sour gasoline resistance and sour gasohol resistance. These properties of said multi-component copolymer rubber can further be improved by incorporating into the copolymer rubber a crosslinking agent, a metal salt, a vinylidene fluoride polymer, a vinyl chloride resin or other multi-component copolymer rubber.

Multi-component copolymer rubber, a process for producing the same, and

Conjugated diolefinic polymers having a molecular weight of less than 1,000,000 can be produced at high polymerization rates and in high yields by polymerizing a conjugated diolefin or copolymerizing a conjugated diolefin with a vinyl aromatic hydrocarbon in the presence of an alfin catalyst, in which as a molecular weight regulator is used a halogenated unsaturated hydrocarbon represented by the formula, ##EQU1## wherein R is an alkyl group having 1 to 7 carbon atoms, a vinyl group, a phenyl group, an alkyl-substituted phenyl group, a halogen atom or a hydrogen atom, and X, Y and Z which may be same or different are individually a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms, at least one of the R, X, Y and Z being a halogen atom. The above-mentioned molecular weight regulator not only displays a prominent molecular weight-regulating effect, even when used in a small amount, but also is easily commercially obtainable and inexpensive, so that marked commercial advantages can be attained according to the above-mentioned process.

Process for producing conjugated diolefinic polymers

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Yokkaichi, Japan

Nobuyuki Sakabe