Patents by Inventor Keizou Yokoi

Keizou Yokoi 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).

  • Patent number: 7470414
    Abstract: High purity phosphoric acid having an Sb content of 200 ppb or less and a sulfide ion content of 200 ppb or less as impurity contents on a 85 weight percent H3PO4 basis. The high purity phosphoric acid is useful as an etching solution for semiconductor devices having a silicon nitride film, an etching solution for liquid crystal display panels having an alumina film, a metallic aluminum etching solution, an alumina etching solution for ceramics, a raw material of phosphate glass for optical fiber, a food additive, and so forth. A metallic material having low capability of forming a lithium compound penetrates through the whole thickness of the active material layer 5.
    Type: Grant
    Filed: June 28, 2004
    Date of Patent: December 30, 2008
    Assignee: Nippon Chemical Industrial Co., Ltd.
    Inventors: Kenichi Ishikawa, Keizou Yokoi, Kosuke Takeuchi, Yutaka Kurita, Heiji Uchiyama
  • Publication number: 20060073088
    Abstract: High purity phosphoric acid having an Sb content of 200 ppb or less and a sulfide ion content of 200 ppb or less as impurity contents on a 85 weight percent H3PO4 basis. The high purity phosphoric acid is useful as an etching solution for semiconductor devices having a silicon nitride film, an etching solution for liquid crystal display panels having an alumina film, a metallic aluminum etching solution, an alumina etching solution for ceramics, a raw material of phosphate glass for optical fiber, a food additive, and so forth. A metallic material having low capability of forming a lithium compound penetrates through the whole thickness of the active material layer 5.
    Type: Application
    Filed: June 28, 2004
    Publication date: April 6, 2006
    Inventors: Kenichi Ishikawa, Keizou Yokoi, Kosuke Takeuchi, Yutaka Kurita, Heiji Uchiyama