Nippon Zeon Company, Ltd.

Zeon Corporation

Takafumi Kawanaka

Hiroyuki Watanabe

Kohkichi Noguchi

Kiyoshi Hosoya

Kazuhiro Takahashi

Osamu Mori

Shizuo Kitahara

Shuichi Akita

Yoshiaki Aimura

Akira Tsukada

Hiroyasu Nagamori

Haruhiko Fujita

Hiroyuki Kotsuji

Takuji Kishimoto

Masahiro Shimizu

Takeshi Ohishi

Hirofumi Masuda

Tetuya Toyoshima

A nitrile group-containing copolymer rubber comprising 10 to 40 wt % of &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile unit (a), 10 to 60 wt % of &#x3b1;,&#x3b2;-ethylenically unsaturated carboxylic acid ester unit (b), and 20 to 70 wt % in total of conjugated diene unit (c) and saturated conjugated diene unit (d), wherein a content ratio 'x' of a conjugated diene unit (c) based on the total content of said conjugated diene unit (c) and said saturated conjugated diene unit (d) is 0.08 or smaller, and 'x&#xb7;A' defined as a product of said ratio &#x201c;x&#x201d; and a content ratio &#x201c;A&#x201d; (%) of said &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile unit (a) is 1.5 or smaller. According to the present invention, a nitrile group-containing copolymer rubber capable to provide a rubber vulcanizate highly balanced in mechanical strength, heat aging resistance, oil resistance, cold resistance and ozone resistance, and a vulcanizable rubber composition using the rubber can be provided.

Nitrile group-containing copolymer rubber and a vulcanizable nitrile group-containing copolymer rubber composition

A process for hydrogenating a conjugated diene polymer wherein a conjugated diene polymer is hydrogenated in the presence of a catalyst comprising a platinum group metal or its compound, and a basic compound. More specifically, (1) hydrogenation is conducted in a reaction system prepared by incorporating the catalyst and the basic compound in a solution or latex of the conjugated diene polymer; (2) hydrogenation is conducted in a reaction system prepared by incorporating a catalyst system comprising a combination of the catalyst with the basic compound, in a solution or latex of the conjugated diene polymer; or (3) hydrogenation is conducted in a reaction system prepared by incorporating the catalyst in a solution of a composition comprising the conjugated diene polymer and the basic compound. Thus, a hydrogenated conjugated diene polymer can be efficiently and industrially advantageously produced using a small amount of a catalyst.

Method of hydrogenating conjugated diene polymer, hydrogenation catalyst system, and composition of basic, conjugated diene polymer

A crosslinkable rubber composition comprising (a) 100 weight parts of a nitrile group-containing highly saturated copolymer rubber containing units of an ethlenically unsaturated dicarboxylic acid monoalkyl ester monomer, (b) 0.5 to 10 parts by weight of a polyamine crosslinking agent, and (c) 0.5 to 10 parts by weight of a basic crosslinking accelerator. This rubber composition gives a crosslinked nitrile group-containing highly saturated copolymer rubber article having excellent heat resistance, flex fatigue resistance and elongation, and reduced permanent set.

Crosslinkable rubber composition and crosslinked object

There are provided an acrylate polymer elastomer containing a particular acrylic ester unit as a constitutive component, and a vulcanizable composition comprising the elastomer and a vulcanizing agent. The acrylate polymer elastomer is obtained by copolymerizing

Acrylate polymer elastomer and vulcanizable composition containing the

An additive for improving the dispersibility of a particulate substance in an organic medium, a thermoplastic polymer, or a thermosetting resin, is at least one compound having a ##STR1## bond in the molecule, including, for example, compounds having an oxazolinium ion in the molecule. The preferred additive compounds are oligomeric or polymeric.

Additive for organic medium or thermoplastic polymer

There are provided an acrylic copolymer elastomer containing an acrylic acid polyalkylene glycol ester as a constituent, and a vulcanizable composition comprising said elastomer and a vulcanizing agent, which composition gives a vulcanizate excellent in cold resistance, heat resistance and oil resistance. The acrylic copolymer elastomer is obtained by copolymerizing

Acrylic copolymer elastomer and vulcanizable composition containing same

An improved diene type polymer rubber is prepared by reacting a diene type polymer rubber, to which an alkali metal and/or an alkaline earth metal has been added, with a compound represented by the formula: ##STR1## wherein M is oxygen or sulfur, R.sub.1 and R.sub.4 are a substituent having no hydrogen on the .alpha.-carbon atom, R.sub.2 and R.sub.3 are hydrogen or a hydrocarbon group, m is an integer of at least 2, and n is an integer of 2 to 4. The diene type polymer rubber is characterized in that, even after storage for a long time, the Mooney viscosity rises only to a very slight extent, and the rebound, wet skid resistance and other physical properties of the cured product thereof are not substantially changed.

Growing community of inventors

Yokohama, Japan

Takafumi Kawanaka