Patents by Inventor Tsukawa Takahashi

Tsukawa Takahashi 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).

  • Zirconia sol, method for production thereof, porous ceramic-producing slurry, and porous ceramic product obtained by use thereof
    Patent number: 5275759
    Abstract: A highly concentrated zirconia sol is produced by a method which comprises heating an aqueous solution of a zirconium salt in the presence of urea thereby obtaining a transparent zirconia sol, concentrating the zirconium sol with an ultrafilter membrane, and subjecting the concentrated zirconic sol to thermal concentration at a temperature of not higher than 80.degree. C. The sol thus obtained enjoys lasting stability. Optionally, this sol may incorporate therein a chelating agent and a compound of a metal other than zirconium. A slurry of the zirconia sol incorporating therein minute refractory particles is useful for the manufacture of a porous ceramic article. A ceramic product obtained by firing this slurry is advantageously used in a mold for casting.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: January 4, 1994
    Assignee: Nippon Shokubai Kagaku Kogyo Co., Ltd.
    Inventors: Shigemi Osaka, Kazuo Hata, Tsukawa Takahashi, Teruyuki Moto