Zeon Corporation

Atsuhiro Shiono

Yoshio Fukumine

Arinobu Katada

Tomoyuki Shibuya

Kentarou Mori

A method for producing a nitrile group-containing copolymer rubber including copolymerizing a monomer mixture containing an &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer and a conjugated diene monomer, in which the copolymer has a Mooney viscosity (ML1+4, 100&#xb0; C.) in a range of 30 to 60 at a time point when a polymerization conversion rate is 60%, the copolymerization is carried out until the polymerization conversion rate reaches 85% or more, and the obtained nitrile group-containing copolymer rubber has a Mooney viscosity (ML1+4, 100&#xb0; C.) of 85 to 150.

Method for producing nitrile group-containing copolymer rubber

A nitrile group-containing copolymer rubber including 10 to 60 wt % of an &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer unit and 1 to 60 wt % of an &#x3b1;,&#x3b2;-ethylenically unsaturated dicarboxylic acid monoester monomer unit, and having an iodine value of 120 or less, wherein a processability index Ipro (Ipro=CC&#xd7;SA) is 0.0030 or less, where the processability index Ipro is the product of the carboxyl group content CC, which is the number of moles of carboxyl groups per 100 g of nitrile group-containing copolymer rubber, and the absorbance area SA of a carboxylic anhydride group determined by infrared spectroscopy.

Nitrile group-containing copolymer rubber

The present invention provides a nitrile group-containing highly saturated copolymer rubber comprising an &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer unit in a content of 15 wt % or more and less than 28 wt %, an &#x3b1;,&#x3b2;-ethylenically unsaturated monocarboxylic acid ester monomer unit (b) in a content of 10 to 50 wt %, and a conjugated diene monomer unit (c) in a content of 22 to 75 wt %, and having an iodine value of 120 or less, wherein the conjugated diene monomer unit (c) is at least partially hydrogenated, and a proportion of an isoprene unit in the conjugated diene monomer unit (c) is 33 wt % or more.

Nitrile group-containing highly saturated copolymer rubber

The present invention provides a nitrile group-containing highly-saturated copolymer rubber comprising an &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer unit (a) in a content of 28 wt % or more and a conjugated diene monomer unit (b) in a content of 20 to 72 wt %, and having an iodine value of 120 or less, wherein the conjugated diene monomer unit (b) is at least partially hydrogenated, and a proportion of an isoprene unit in the conjugated diene monomer unit (b) is 33 wt % or more.

A cross-linkable nitrile rubber composition has a carboxyl group-containing nitrile rubber (A) with an iodine value of 120 or less, polyamine cross-linking agent (B), and at least one compound (C) selected from an aliphatic alcohol (c1) having 1 to 9 carbon atoms, hydroxyl group-containing aromatic compound (c2), and nitrogen-containing heterocyclic compound (c3).

Cross-linkable nitrile rubber composition and cross-linked rubber

A cross-linked rubber is excellent in both fuel oil resistance and cold resistance. A cross-linkable rubber composition contains: a nitrile group-containing copolymer rubber [A] including less than 30 wt % &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer units (a1), conjugated diene monomer units (b1), and &#x3b1;,&#x3b2;-ethylenically unsaturated dicarboxylic acid monoester monomer units (d1), wherein at least part of the conjugated diene monomer units (b1) is hydrogenated; a nitrile group-containing copolymer rubber [B] including not less than 30 wt % &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer units (a2) and conjugated diene monomer units (b2), wherein at least part of the conjugated diene monomer units (b2) may be hydrogenated; and an amine-based cross-linking agent.

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Tokyo, Japan

Atsuhiro Shiono