Patents by Inventor Takahiro Ohnuki

Takahiro Ohnuki 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 the phosphate chemical conversion treatment of a steel material
    Patent number: 4880476
    Abstract: A corrosion-resistant phosphate chemical conversion coating layer is formed on a steel material surface by a process comprising bringing the steel material into contact with a treatment liquid containing mixed anions consisting of phosphate ions and at least one other type of active anions, at least one type of metal ions, and an oxidizing agent, to provide a phosphate chemical conversion coating layer on the surface of the steel material, wherein the ratio (P/An) in weight of the phosphate ions (P) to the total of mixed anions (An) is 1/2 or less and the temperature of the treatment liquid is maintained at a level of 40.degree. C. or less without external heating.
    Type: Grant
    Filed: December 9, 1987
    Date of Patent: November 14, 1989
    Assignees: Nippondenso Co., Ltd., Nihon Parkerizing Co., Ltd.
    Inventors: Shigeki Matsuda, Kazuhiko Mori, Wataru Gotou, Takahiro Ohnuki