Patents by Inventor Shouji Obuchi

Shouji 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).

  • Production process of aromatic polyamide
    Patent number: 4923951
    Abstract: An aromatic polyamide is produced by subjecting an aromatic diisocyanate and an aromatic dicarboxylic acid to polycondensation in the presence of an alkali metal compound and/or an alkaline earth metal compound as a catalyst in an aprotonic polar solvent. The aromatic polyamide can be rendered suitable for use in the production of high-tenacity fibers by charging in advance the solvent, aromatic dicarboxylic acid and catalyst in a mixing system, reducing the water content in the mixing system to at least 50 ppm and then introducing the aromatic diisocyanate to conduct the polycondensation.
    Type: Grant
    Filed: February 7, 1989
    Date of Patent: May 8, 1990
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Kobayashi, Shouji Obuchi, Hiroaki Matsuno, Mitsuo Wada, Hiroshi Takayanagi