Patents by Inventor Hiroyuki Kotsuji

Hiroyuki Kotsuji has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Rubber, rubber composition, and crosslinked object
    Patent number: 6812312
    Abstract: A nitrile group-containing highly saturated copolymer rubber comprising (a) 0 to 20% by weight of 1,3-butadiene units, (b) 0 to 50% by weight of saturated 1,3-butadiene units, (c) 40 to 50% by weight of &agr;,&bgr;-ethylenically unsaturated nitrile monomer units, and (d) 10 to 35% by weight and at least 8% by mol of other monomer units, wherein the sum of 1,3-butadiene units (a) and saturated 1,3-butadiene units (b) is in the range of 20 to 50% by weight. A rubber composition comprising this copolymer rubber and a crosslinking agent gives a crosslinked product exhibiting good oil resistance, namely, good resistance to rancid gasoline and not hardening even when it is placed in contact with oil containing condensed aromatics.
    Type: Grant
    Filed: April 15, 2002
    Date of Patent: November 2, 2004
    Assignee: Zeon Corporation
    Inventors: Suguru Ito, Hiroyuki Kotsuji, Hiroko Ohnishi
  • Crosslinkable rubber composition and crosslinked object
    Patent number: 6657014
    Abstract: 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.
    Type: Grant
    Filed: February 20, 2002
    Date of Patent: December 2, 2003
    Assignee: Zeon Corporation
    Inventors: Osamu Mori, Takafumi Kawanaka, Yoshiaki Aimura, Hiroyuki Kotsuji, Haruhiko Fujita
  • Rubber, crosslinkable rubber composition, and crosslinked object
    Patent number: 6548604
    Abstract: A nitrile group-containing highly saturated copolymer rubber comprising (a) 10-40 wt. % of &agr;,&bgr;-ethylenically unsaturated nitrile monomer units, (b) 10-60 wt. % of &agr;,&bgr;-ethylenically unsaturated carboxylic acid ester monomer units, (c) 0.01-21 wt. % of conjugated diene monomer units, and (d) 14-69.99 wt. % of saturated conjugated diene monomer units, wherein the sum of monomer units (c) plus (d) is 20-70 wt. %, the ratio of monomer units (d)/[monomer units (c) plus (d)] is at least 70 wt. %, and the difference between the extrapolated glass transition-initiating temperature (Tig) and the extrapolated glass transition-ending temperature (Teg), as measured by DSC is not higher than 10° C. The copolymer rubber gives a crosslinked product having good cold resistance, oil resistance and dynamic properties.
    Type: Grant
    Filed: April 15, 2002
    Date of Patent: April 15, 2003
    Assignee: Zeon Corporation
    Inventors: Hiroyuki Kotsuji, Akira Tsukada