Patents by Inventor Masumi Rokkaku

Masumi Rokkaku 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).

  • High temperature stable alumina and method of manufacturing the same
    Patent number: 5905048
    Abstract: To provide a high-temperature stable transition-type alumina that does not undergo transformation into .alpha.-alumina even at high-temperature exceeding 1300.degree. C., and a method for producing the transition-type alumina.A metal aluminum block is placed on a block of .alpha.-alumina composed of Al.sub.2 O.sub.3. Portions of the .alpha.-alumina block and the metal aluminum block close to their boundary was strongly heated by contacting the flame of burning gas with the portions. Alumina and a relatively small amount of magnesium are thereby vaporized, and allowed to react with oxygen in the atmosphere, thereby obtaining a transition-type alumina that contains a small amount of magnesium in the crystal structure. The transition-type alumina obtained by this method is substantially of single crystal type, and does not undergo transformation into .alpha.-alumina even at high temperatures exceeding 1300.degree. C.
    Type: Grant
    Filed: September 26, 1997
    Date of Patent: May 18, 1999
    Assignee: Japan Fine Ceramics Center
    Inventors: Michiko Kusunoki, Masumi Rokkaku, Yuichi Ikuhara