Patents by Inventor Yoshihisa Koiwai

Yoshihisa Koiwai 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 metal powder
    Patent number: 4437883
    Abstract: Metal powder having low oxygen and carbon contents and suitable for powder metallurgy may be obtained by using, as an atomizing medium, a special composition containing an alcohol having 1-4 carbon atoms and water as its essential components when impinging the atomizing medium against a molten metal in a state isolated from the ambient air to produce the metal powder.
    Type: Grant
    Filed: February 14, 1983
    Date of Patent: March 20, 1984
    Assignees: Sumitomo Metal Industries, Ltd., Nippon Oil Co. Ltd.
    Inventors: Toshihiko Kubo, Minoru Ichidate, Toshiyuki Kawai, Sadao Yonehara, Yoshihisa Koiwai, Kazuhiko Endo
  • Method for regenerating and recycling catalyst for oxidation of sulfur dioxide
    Patent number: 4101635
    Abstract: In a method for oxidizing sulfur dioxide by contacting a sulfur dioxide-containing gas and an oxygen-containing gas with an aqueous solution containing pentavalent vanadium and divalent manganese as a catalyst, the method for regenerating and recycling the oxidation catalyst which comprises adding at least one calcium compound selected from the group consisting of calcium oxide, calcium hydroxide and calcium carbonate and an oxygen-containing gas as an oxidizing agent to at least a part of the aqueous solution catalyst used in the oxidation reaction, separating the resulting gypsum, and recycling the recovered aqueous solution catalyst for use in the oxidation of sulfur dioxide.
    Type: Grant
    Filed: February 28, 1977
    Date of Patent: July 18, 1978
    Assignee: Nippon Oil Company Ltd.
    Inventors: Masao Nambu, Syunichi Yamamoto, Yoshihisa Koiwai