Nippon Zeon Company, Ltd.

Nippon Zenn Co. Ltd.

Yoichiro Kubo

Noboru Watanabe

Motofumi Oyama

Kiyomori Ohura

Yoshiaki Aimura

Sachio Hayashi

Toshiharu Honda

Kazuhiro Takahashi

Kiyomori Oura

Eitaro Nakamura

Takaaki Kohtaki

Shizuo Kitahara

Tetsu Ohishi

Riso Iwata

Hideyoshi Shimoda

Tsuyoshi Nakagawa

Hideyoshi Shomoda

Disclosed herein is a process for the selective hydrogenation of the carbon-carbon double bonds of an unsaturated, nitrile-group-containing polymer with hydrogen in the presence of a hydrogenation catalyst. An aqueous emulsion of the unsaturated, nitrile-group-containing polymer is used. Optionally, an organic solvent capable of dissolving or swelling the polymer is caused to exist at a volume ratio of the aqueous emulsion to the organic solvent in a range of from 1:3 to 1:0. A palladium compound is used as the hydrogenation catalyst. The aqueous emulsion is brought into contact with gaseous or dissolved hydrogen while maintaining an emulsified state.

Hydrogenation process of unsaturated, nitrile-group-containing polymer

A catalyst comprising a high-molecular complex formed from a palladium compound and a nitrile group-containing polymer, and a method for hydrogenating a conjugated diene polymer which comprises selectively hydrogenating only a carbon-carbon double bond of the conjugated diene polymer using same.

Method for hydrogenating conjugated diene polymer

In a method for hydrogenating a nitrile group-containing unsaturated copolymer which comprises selectively hydrogenating only a carbon-carbon double bond of the nitrile group-containing unsaturated copolymer in solution, the improvement wherein a palladium complex represented by formula

Method for hydrogenating nitrile group-containing unsaturated copolymer

Disclosed is a magnetic recording medium comprising a non-magnetic support and a magnetic layer composed mainly of a ferromagnetic powder and a binder, which is formed on one surface of the support, and an optional backcoat layer composed mainly of a non-magnetic powder and a binder, which is formed on the other surface of the support. At least one of the magnetic layer and the backcoat layer contains a compound having at least one &gt;C.dbd.N.sup..sym. &lt; bond in the molecule. When preparing the magnetic recording medium, the magnetic powder or non-magnetic powder may be surface-treated with the &gt;C.dbd.N.sup..sym. &lt; group-containing compound.

Magnetic recording medium comprising a magnetic layer or backcoat layer

A catalyst comprising a high-molecular complex formed from a palladium compound and anitrile group-containing polymer, and a method for hydrogenating a conjugated diene polymer which comprises selectively hydrogenating only a carbon-carbon double bond of the conjugated diene polymer using same.

A nitrile group-containing, highly saturated copolymer rubber is disclosed, the copolymer chain of which is comprised of (1) 5 to 40% by weight of units of an unsaturated nitrile monomer, (2) 1 to 80% by weight of units of a monomer selected from a fluorine-free unsaturated carboxylic acid ester monomer and a fluorine-containing vinyl monomer and (3) up to 20% by weight of units of a conjugated diene monomer, with the balance being (4) units of a hydrogenated conjugated diene monomer, wherein the sum of the contents of the monomer units (1) and (2) is 30 to 90% and the sum of the contents of the monomer units (3) and (4) is 10 to 70% by weight. This copolymer rubber results in a rubber composition having an improved cold resistance.

Nitrile group-containing highly saturated copolymer rubber and rubber

A rubber composition comprising a nitrile group-containing hydrocarbon rubber and a vulcanizing system, characterized in that the iodine value of said rubber does not exceed 120 and the pH of the tetrahydrofuran solution of said rubber is at least 5.

Method of vulcanizing rubber at pH 5 to 10

A process for hydrogenating a conjugated diene polymer which comprises hydrogenating the carbon-carbon double bond of the conjugated diene polymer using a hydrogenation catalyst supported on a carrier, the carrier being an oxide of an element of Group IVa of the periodic table such as TiO.sub.2 or ZrO.sub.2.

Process for hydrogenating conjugated diene polymers

An anti-degrading rubber article to be used in contact with a mineral oil containing an oil modifier, at least that surface of said rubber article which is to come into contact with said mineral oil being composed substantially of a vulcanization product, obtained by using a sulfur vulcanization system, of a copolymer rubber having polymer chains consisting of

Oil-resistant and anti-degrading rubber article

For use in sealing semiconductors, an epoxy resin composition is provided which comprises an epoxy resin, a curing agent, a filler and a modifier, wherein the modifier is a diene polymer or acrylic polymer having an iodine number of not more than 120 or both included in an amount of 1 to 50 parts by weight per 100 parts by weight of the epoxy resin.

Sealed semiconductor containing an epoxy resin composition

A rubber article with excellent oil resistance and aging resistance to be used in contact with a polyolefin oil or a lubricating oil containing a polyolefin oil, at least the surface of the rubber article being contacted with said oil, said rubber article being composed substantially of a vulcanized product of a copolymer rubber comprising (1) 10 to 60% by weight of units derived from an unsaturated nitrile, (2) 0 to 30% by weight of units derived from a conjugated diene, and (3) 90 to 10% by weight of units derived from an ethylenically unsaturated monomer other than the unsaturated nitrile and/or units resulting from the hydrogenation of units derived from a conjugated diene.

Rubber member having oil resistance and resistance to deterioration

A heat-resistant and oil-resistant rubber composition comprising a nitrile group-containing rubber having an iodine value of not more than 120 and a nitrile group-containing liquid polymer having an iodine value of not more than 120.

Oil-resistant rubber composition

A belt comprising a copolymer rubber and fibers and having strong adhesion strength even after heat-aging in air or oil and repeated deformation. The copolymer rubber has in its polymer chain (1) 10 to 60% by weight of units derived from an unsaturated nitrile, (2) 0 to 30% by weight of units derived from a conjugated diene and (3) 10 to 90% by weight of units derived from an ethylenically unsaturated monomer other than unsaturated nitriles and/or units formed by hydrogenating units derived from a conjugated diene.

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Yokohama, Japan

Yoichiro Kubo