Patents by Inventor Kiyoshi Iwahashi

Kiyoshi Iwahashi 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 production of methyltetrahydrophthalic anhydride
    Patent number: 5237074
    Abstract: This invention provides a process for producing methyltetrahydrophthalic anhydride characterized in that maleic anhydride and a C.sub.5 fraction are subjected to Diels-Alder reaction in the presence of a radical polymerization inhibitor and oxygen. According to the process of this invention, formation of gels as byproduct is substantially completely inhibited.
    Type: Grant
    Filed: October 21, 1991
    Date of Patent: August 17, 1993
    Assignee: New Japan Chemical Co., Ltd.
    Inventors: Shoji Tani, Kenji Nishio, Kiyoshi Iwahashi, Shigeki Hashimoto