Patents by Inventor Tatsuhiko Ejima

Tatsuhiko Ejima 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 treating surface of aluminum foil for use as electrode of electrolytic capacitors
    Patent number: 4547275
    Abstract: A process for treating the surface of aluminum foil for use as an electrode of electrolytic capacitors to increase the surface area of the foil to the greatest possible extent includes the three steps of pre-etching treatment, intermediate nitric acid treatment and post-etching treatment. The pre-etching treatment is conducted electrolytically in an aqueous solution of chromic acid and at least one of chromic acid and chromates. The intermediate nitric acid treatment is carried out by immersing the pre-etched foil in an aqueous solution of nitric acid to remove a chromate film formed by the pre-etching from the foil surface, especially from the interior of the resulting pits. The post-etching treatment is conducted electrolytically in an aqueous solution of hydrochloric acid, or hydrochloric acid and an oxidizing acid.
    Type: Grant
    Filed: January 28, 1985
    Date of Patent: October 15, 1985
    Assignee: Showa Aluminum Kabushiki Kaisha
    Inventors: Tatsuhiko Ejima, Kozo Arai, Eizo Isoyama, Tadao Fujihira