Patents by Inventor Hisanori Ohta

Hisanori Ohta 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).

  • Process for producing dip-formed rubber article
    Patent number: 6372856
    Abstract: A dip-formed rubber article is produced by dip-forming a vulcanizable rubber latex composition comprising an unsaturated nitrile-conjugated diene copolymer rubber latex, a sulfur-containing vulcanizer, and at least one vulcanization accelerator selected from (i) dithiocarbamic acid compounds of the formula (1): wherein R1 and R2 independently represent and hydrocarbon group having at least 6 carbon atoms, and (ii) zinc dithiocarbamate compounds of the formula (2): wherein R1 and R2 are as defined above.
    Type: Grant
    Filed: January 16, 2001
    Date of Patent: April 16, 2002
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Yutaka Ozawa, Hisanori Ohta
  • Process for producing dip-formed rubber article
    Publication number: 20010004653
    Abstract: A vulcanizable dip-forming rubber latex composition comprising an unsaturated nitrile-conjugated diene copolymer rubber latex, a sulfur-containing vulcanizer, and a vulcanization accelerator comprising at least one compound selected from (i) dithiocarbamic acid compounds of the formula: 1
    Type: Application
    Filed: January 16, 2001
    Publication date: June 21, 2001
    Inventors: Yutaka Ozawa, Hisanori Ohta
  • Dipping latex composition and rubber articles made therefrom by dipping
    Patent number: 6187857
    Abstract: A vulcanizable dip-forming rubber latex composition comprising an unsaturated nitrile-conjugated diene copolymer rubber latex, a sulfur-containing vulcanizer, and a vulcanization accelerator comprising at least one compound selected from (i) dithiocarbamic acid compounds of the formula: and (ii) zinc dithiocarbamate compounds of the formula: wherein R1 and R2 are hydrocarbon groups having at least 6 carbon atoms which may be the same or different, and an optional thiazole compound. A rubber article dip-formed from the rubber latex composition has no crack occurrence, good surface luster and good vulcanization properties, and does not contain a nitrosamine, and therefore, is suitable for medical use.
    Type: Grant
    Filed: January 22, 1999
    Date of Patent: February 13, 2001
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Yutaka Ozawa, Hisanori Ohta
  • Copolymer latex, method for preparing the same and use thereof
    Patent number: 5369166
    Abstract: A copolymer latex is provided which comprises 30 to 90% by weight of a conjugated diene monomer unit, 9 to 50% by weight of an ethylenically unsaturated nitrile monomer unit, 0.1 to 20% by weight of an ethylenically unsaturated acid monomer unit and 0 to 20% by weight of an other ethylenically unsaturated monomer unit copolymerizable therewith, having a polystyrene-converted weight average molecular weight of 50,000 to 500,000, and containing 45% or less of methyl ethyl ketone insoluble matter. The latex is presented by emulsion polymerization using a polymerization initiator containing a peroxide whose decomposition temperature giving a half-life period of 10 hours is 100.degree. C. or higher and a reducing agent. The latex is used advantageously for dip molding.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: November 29, 1994
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Yutaka Ozawa, Hisanori Ohta