Patents by Inventor Takakazu Kojima

Takakazu Kojima 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).

  • 3,6-diamino-2,5-pyrazinedicarbonitrile
    Patent number: 5317102
    Abstract: This invention relates to 3,6-diamino-2,5-pyrazinedicarbonitrile which is a red crystal and yellowish green fluorenscent substance and the methods of preparation from compounds represented by formula [I], ##STR1## (wherein R are aryl, alkyl, aralkyl or alkenyl or may be substituted), as a starting material, under acidic condition in the presence of oxygen.
    Type: Grant
    Filed: August 7, 1992
    Date of Patent: May 31, 1994
    Assignee: Nippon Soda Co., Ltd.
    Inventors: Seiji Tazaki, Tomio Yagihara, Nobuo Matsui, Atsushi Yanagisawa, Takakazu Kojima
  • 3,6-diamino-2,5-pyrazinedicarbonitrile
    Patent number: 5294711
    Abstract: This invention relates to 3,6-diamino-2,5-pyrazinedicarbonitrile which is a red crystal and yellowish green fluorescent substance and the methods of preparation from compounds represented by formula [I], ##STR1## (wherein R are aryl, alkyl, aralkyl or alkenyl or may be substituted), as a starting material, under acidic condition in the presence of oxygen.
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: March 15, 1994
    Assignee: Nippon Soda Co., Ltd.
    Inventors: Seiji Tazaki, Tomio Yagihara, Nobuo Matsui, Atsushi Yanagisawa, Takakazu Kojima
  • Process for producing 4-carboxamido-5-cyano-2-imidazolone
    Patent number: 4128719
    Abstract: A process for producing 4-carboxamido-5-cyano-2-imidazolone which comprises reacting diaminomaleonitrile with carbon dioxide in a polar solvent, optionally in the presence of a basic catalyst.
    Type: Grant
    Filed: December 16, 1977
    Date of Patent: December 5, 1978
    Assignee: Sagami Chemical Research Center
    Inventors: Takakazu Kojima, Yozo Ohtsuka
  • Process for producing 4-carboxamido-5-cyano-2-imidazolone
    Patent number: 4093810
    Abstract: A process for producing 4-carboxamido-5-cyano-2-imidazolone which comprises reacting diaminomaleonitrile with carbon dioxide in a polar solvent, optionally in the presence of a basic catalyst.
    Type: Grant
    Filed: July 26, 1976
    Date of Patent: June 6, 1978
    Assignee: Sagami Chemical Research Center
    Inventors: Takakazu Kojima, Yozo Ohtsuka