Patents by Inventor Hidehiro Nakao

Hidehiro Nakao 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: 6245389
    Abstract: A method of circulating an electroless nickel plating solution is characterized in that the system comprises the following process steps effected in the following order: (A) a step of electrolessly plating nickel using a plating solution having nickel hypophosphite contained as a chief chemical material for supplying a plating metal ion Ni2+ and a hypophosphorous acid ion H2PO2− acting as a reducing agent; (B) a step of removing HPO32− from a plating solution that has aged in the step (A); (C) a step of desalting the mother liquor separated from the step (B); and (D) a step of adjusting the components of the treated plating solution and then circulating same back into the step (A) of electroless nickel plating. According to the present invention, the plating solution is free from the formation and accumulation of a sulfuric acid salt and hence a long service life is ensured and a great advantage in environmental protection is provided.
    Type: Grant
    Filed: August 26, 1998
    Date of Patent: June 12, 2001
    Assignees: Nippon Chemical Industrial Co., Ltd., Meltex, Inc.
    Inventors: Ken Horikawa, Muneo Mita, Hidehiro Nakao, Katsuhiro Tashiro