Patents by Inventor Shuichi Tokumoto

Shuichi Tokumoto 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 preparation of acyclic ethyleneamines
    Patent number: 5082972
    Abstract: At least one of ammonia and ethylenediamine is reacted with monoethanolamine in the presence of a catalyst containing phosphoric acid or its condensate in order to prepare acyclic ethyleneamines, and the catalyst can be improved in performance and the life of the catalyst can be prolonged by feeding a phosphorus-containing material to a reaction system during the reaction. In addition, the catalyst having a deteriorated performance can be reactivated by adding the phosphorus-containing material to the catalyst.
    Type: Grant
    Filed: July 11, 1990
    Date of Patent: January 21, 1992
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Komiyama, Hisaharu Kuboyama, Takashi Jimbo, Hiroyoshi Watanabe, Shuichi Tokumoto, Yumiko Endoh, Eiichi Sugiyama, Yoshitaro Naganuma