Patents by Inventor Takayuki Ishizuki

Takayuki Ishizuki 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 producing columbite-type niobate and process for producing perovskite-type compound therefrom
    Patent number: 5366718
    Abstract: A process for producing a columbite-type niobate and a process for producing a niobium-containing lead-type perovskite compound using the columbite-type niobate. A precursor slurry of a columbite compound composed of a fresh niobium hydroxide, a metal acetate and ammonium aqueous solution is spray-dried, and is calcined at 500.degree. C. or higher to obtain a crystalline columbite-type compound having grain sizes of 1 .mu.m or smaller to which was then mixed a lead component. The mixture is calcined, pulverized and is sintered at a temperature of 800.degree. to 1100.degree. C. to synthesize a highly dielectric material of a niobium-containing lead-type composite perovskite. The precursor of columbite is calcined at 500.degree. to 1100.degree. C. to obtain fine columbite-type niobate crystals of grain sizes of 1 .mu.m or smaller. A lead-type perovskite compound using the above crystals can be sintered at a temperature of as low as 950.degree. C.
    Type: Grant
    Filed: November 10, 1993
    Date of Patent: November 22, 1994
    Assignees: Mizusawa Industrial Chemicals Ltd., TDK Corporation
    Inventors: Teiji Sato, Hitoshi Nakata, Takayuki Ishizuki, Shoichi Iwaya, Koji Takahashi, Yuuiti Sannohe, Hitoshi Tanaka