Patents by Inventor Kazumitsu Hishinuma

Kazumitsu Hishinuma 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).

  • Hydrothermal process for preparing zirconia-alumina base ultra-fine powders of high purity
    Patent number: 4769351
    Abstract: A process for preparing a zirconia-alumina base composite ultra-fine powder is described, including the steps of: mixing an aluminum salt or an alumina hydrate with an aqueous zirconium oxychloride solution, with or without metal salt acting as a stabilizer; mixing urea or a substance capable of generating ammonia by hydrolysis with the resulting mixture; and allowing the mixture to react at a temperature of 140.degree. to 300.degree. C. and a pressure of 4 to 150 kg/cm.sup.2 in a high-temperature and -pressure vessel. The reaction product is further dried, calcined and crushed to obtain an ultra-fine powder.
    Type: Grant
    Filed: May 4, 1987
    Date of Patent: September 6, 1988
    Assignees: Chichibu Cement Co., Ltd., Shigeyuki Soumiya
    Inventors: Shigeyuki Soumiya, Masahiro Yoshimura, Zenjiro Nakai, Kazumitsu Hishinuma, Takao Kumaki