Patents by Inventor Masatsugu Kawawaki

Masatsugu Kawawaki 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).

  • Purification method for producing high purity niobium compound and/or tantalum compound
    Patent number: 7214362
    Abstract: An object of the present invention is to provide a method for purifying a highly pure niobium compound and/or tantalum compound, the method enabling the purification of a highly pure niobium compound and tantalum compound in a simplified manner at a low cost. The object is met by providing a method comprising adding an organic solvent to an aqueous solution containing a niobium compound and/or tantalum compound together with impurities, and then performing extraction via the solution. A niobium compound and/or tantalum compound dissolved in a solution is allowed to precipitate, and said aqueous solution is obtained by dissolving the precipitate in water.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: May 8, 2007
    Assignee: Stella Chemifa Kabushiki Kaisha
    Inventors: Hirohisa Kikuyama, Masahide Waki, Hiroto Izumi, Hirofumi Yazaki, Kenji Aoki, Shinji Hashiguchi, Masatsugu Kawawaki, Yuko Murakami
  • Purification method for producing high purity niobium compound and/or tantalum compound
    Patent number: 7175823
    Abstract: The present invention provides a method enabling the high purification of a niobium compound and/or tantalum compound in a simplified manner at a low cost. This is accomplished by providing a method enabling the high purification of a niobium compound and/or tantalum compound comprising the steps of preparing a solution containing niobium and/or tantalum, allowing a precipitate comprising niobium and/or tantalum to develop, separating the precipitate by filtration from the filtrate, converting the precipitate to a liquid melt or taking the filtrate, and separating a niobium compound from a tantalum compound or vice versa by utilizing the difference in solubility to the solvent between the niobium compound and the tantalum compound.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: February 13, 2007
    Assignee: Stella Chemifa Kabushiki Kaisha
    Inventors: Hirohisa Kikuyama, Masahide Waki, Hiroto Izumi, Hirofumi Yazaki, Kenji Aoki, Shinji Hashiguchi, Masatsugu Kawawaki, Yuko Murakami
  • Purification method for producing high purity niobium compound and/or tantalum compound
    Publication number: 20050255035
    Abstract: The present invention provides a method enabling the high purification of a niobium compound and/or tantalum compound in a simplified manner at a low cost. This is accomplished by providing a method enabling the high purification of a niobium compound and/or tantalum compound comprising the steps of preparing a solution containing niobium and/or tantalum, allowing a precipitate comprising niobium and/or tantalum to develop, separating the precipitate by filtration from the filtrate, converting the precipitate to a liquid melt or taking the filtrate, and separating a niobium compound from a tantalum compound or vice versa by utilizing the difference in solubility to the solvent between the niobium compound and the tantalum compound.
    Type: Application
    Filed: February 27, 2003
    Publication date: November 17, 2005
    Inventors: Hirohisa Kikuyama, Masahide Waki, Hiroto Izumi, Hirofumi Yazaki, Kenji Aoki, Shinji Hashiguchi, Masatsugu Kawawaki, Yuko Murakami
  • Method of purifying niobium compound and/or tantalum compound
    Publication number: 20050123459
    Abstract: The present invention provides a method for purifying a niobium compound and/or tantalum compound in a simplified manner at a low cost. This is accomplished by providing a method for purifying a niobium compound and/or tantalum compound whereby a niobium compound and/or tantalum compound dissolved in a solvent is allowed to precipitate to be isolated.
    Type: Application
    Filed: February 27, 2003
    Publication date: June 9, 2005
    Inventors: Hirohisa Kikuyama, Masahide Waki, Hiroto Izumi, Hirofumi Yazaki, Kenji Aoki, Shinji Hashiguchi, Masatsugu Kawawaki, Yuko Murakami
  • Purification method for producing high purity niobium compound and/or tantalum compound
    Publication number: 20050115364
    Abstract: An object of the present invention is to provide a method for purifying a highly pure niobium compound and/or tantalum compound, the method enabling the purification of a highly pure niobium compound and tantalum compound in a simplified manner at a low cost. The object is met by providing a method comprising adding an organic solvent to an aqueous solution containing a niobium compound and/or tantalum compound together with impurities, and then performing extraction via the solution. A niobium compound and/or tantalum compound dissolved in a solution is allowed to precipitate, and said aqueous solution is obtained by dissolving the precipitate in water.
    Type: Application
    Filed: February 27, 2003
    Publication date: June 2, 2005
    Inventors: Hirohisa Kikuyama, Masahide Waki, Hiroto Izumi, Hirofumi Yazaki, Kenji Aoki, Shinji Hashiguchi, Masatsugu Kawawaki, Yuko Murakami