Zeon Corporation

Sayaka Inoue

Tomonori Nakashima

Kentaro Ono

Hiroyasu Nagamori

Nobuyoshi Emori

Chikara Katano

Shiho Mosaki

A method of recovering nitrile rubber from water-containing crumbs includes crumb-like nitrile rubber using an extruder in which a screw is disposed inside a barrel so as to be capable of being rotationally driven. The barrel is formed with at least a washing zone. The method includes supplying washing water to the washing zone at a water pressure of 0.2 MPa or higher while mixing the crumb-like nitrile rubber and the supplied washing water in the washing zone, thereby washing the crumb-like nitrile rubber.

Method for recycling nitrile rubber

A carboxyl group-containing nitrile rubber having an iodine value of 120 or less, wherein the content of sodium is 1500 ppm by weight or less, the total content of calcium, magnesium, and aluminum is 350 ppm by weight or less, and the storage elastic modulus at 140° C. is 350 kPa or more.

Carboxyl group-containing nitrile rubber

A latex of a carboxyl group-containing nitrile rubber contains an &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer unit in a content of 8 to 60 wt % and having an iodine value of 120 or less, wherein the total content of potassium and sodium contained in the latex is 2,300 to 10,000 ppm by weight with respect to the whole latex.

Latex and friction material

A nitrile group-containing highly saturated copolymer rubber composition includes a nitrile group-containing highly saturated copolymer rubber (A) having &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer units and (meth)acrylic acid ester monomer units and having an iodine value of 120 or less and a polyether ester-based plasticizer (B) having structural unit made of three or more ether compounds which are successively bonded. A nitrile group-containing highly saturated copolymer rubber composition excellent in vulcanization speed and giving cross-linked rubber has excellent heat resistance and cold resistance.

Nitrile group-containing highly saturated copolymer rubber composition and cross-linked rubber

A dip-molding composition of the present invention contains a latex (A) of a nitrile-group-containing highly saturated copolymer rubber (a). The nitrile-group-containing highly saturated copolymer rubber (a) contains an &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer unit and a conjugated diene monomer unit, and being obtained by hydrogenating at least part of the conjugated diene monomer unit. A dip-molded article of the present invention is produced by dip molding of the above dip-molding composition.

Composition for dip molding and dip-molded article

A nitrile rubber composition comprising a highly saturated nitrile rubber (A) containing &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer units in a ratio of 8 to 60 wt % and having an iodine value of 120 or less and an alkylated phenol compound (B), wherein a ratio of content of the alkylated phenol compound (B) with respect to a total of the highly saturated nitrile rubber (A) and the alkylated phenol compound (B) is 0.01 to 1 wt %, and a difference (&#x3b7;2&#x2212;&#x3b7;1) between a plasticity number &#x3b7;2 after storage at 70&#xb0; C. for 7 days in a state of an aqueous dispersion by being dispersed in water and a plasticity number &#x3b7;1 before the storage is 12 or less is provided.

Nitrile rubber composition, latex composition of highly saturated nitrile rubber, and cross-linked rubber

A nitrile rubber composition comprising a carboxyl group-containing highly saturated nitrile rubber containing &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer units in a ratio of 5 to 60 wt % and having an iodine value of 120 or less, a filler, and a polyamine-based cross-linking agent, wherein a content of the filler is 100 parts by weight or more and less than 200 parts by weight with respect to 100 parts by weight of the carboxyl group-containing highly saturated nitrile rubber. Accordingly a nitrile rubber composition able to give a cross-linked rubber with excellent in original state physical properties, compression set resistance, and sour gasoline resistance and small in tension set is provided.

Nitrile rubber composition and cross-linked rubber

A nitrile group-containing copolymer rubber containing &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer units in 10 to 60 wt % and having a weight average radius of gyration of 10 to 100 nm in range is provided. According to the present invention, a nitrile group-containing copolymer rubber excellent in processability and able to give cross-linked rubber excellent in normal physical properties can be provided.

Nitrile group-containing copolymer rubber, cross-linkable rubber composition, and cross-linked rubber

A latex for friction member use including rubber particles comprised of a carboxyl group-containing highly saturated nitrile rubber containing &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer units in a ratio of 10 to 60 wt % and having an iodine value of 120 or less, wherein a difference &#x394;d (&#x394;d=d90&#x2212;d50) between a volume cumulative 90% particle size (d90) of the rubber particles and volume cumulative 50% particle size (d50) of the rubber particles which are measured by a light scattering method is 0.0240 &#x3bc;m or more is provided.

Latex for friction member use and friction member

A nitrile group-containing copolymer rubber contains &#x3b1;,&#x3b2;-ethylenically unsaturated nitrile monomer units in a ratio of 10 to 60 wt % and has a Z-average radius of gyration of 100 nm or more. Preferably, the nitrile group-containing copolymer rubber has an iodine value of 120 or less. Further, preferably, the nitrile group-containing copolymer rubber has a plasticity number of 14 to 90. It is possible to provide a nitrile group-containing copolymer rubber able to give a cross-linked rubber excellent in tensile stress, compression set resistance, and low heat buildup property.

Growing community of inventors

Tokyo, Japan

Sayaka Inoue