Patents by Inventor Shouzi Obuchi

Shouzi Obuchi 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 refining 1,3-dimethyl-2-imidazolidinone
    Patent number: 5075406
    Abstract: The present invention is directed to a refining process for removing impurities from 1,3-dimethyl-2-imidazolidinone (DMI) by the use of a composite salt; and a process for preparing an aromatic polyamide having a high polymerization degree from an aromatic diisocyanate and an aromatic dicarboxylic acid by using, as a reaction solvent, DMI purified by the above-mentioned process.
    Type: Grant
    Filed: December 13, 1990
    Date of Patent: December 24, 1991
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Kobayashi, Mitsuo Wada, Shouzi Obuchi, Hiroshi Takayanagi
  • Process for refining 1,3-dimethyl-2-imidazolidinone
    Patent number: 5011936
    Abstract: The present invention is directed to a refining process for removing impurities from 1,3-dimethyl-2-imidazolidinone (DMI) by the use of a composite salt; and a process for preparing an aromatic polyamide having a high polymerization degree from an aromatic diisocyanate and an aromatic dicarboxylic acid by using, as a reaction solvent, DMI purified by the above-mentioned process.
    Type: Grant
    Filed: March 7, 1989
    Date of Patent: April 30, 1991
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Kobayashi, Mitsuo Wada, Shouzi Obuchi, Hiroshi Takayanagi