Patents Assigned to Kabushiki Kaisha Aiden
  • Process for coloring aluminum anodic oxide film
    Patent number: 3962049
    Abstract: An aluminum or aluminum alloy member is immersed in an acidic bath and is subjected to passage of an electrical current to form an anodic oxide film. The applied voltage is lowered either stepwise, linearly, or suddenly to a value in the range between about two-thirds and one one-hundredth, and the voltage is maintained at the lower value for a predetermined period of time, optionally with periodic interruption. The member with the thus formed anodic oxide film is then subjected to an electrolytic coloring treatment.
    Type: Grant
    Filed: May 15, 1972
    Date of Patent: June 8, 1976
    Assignee: Kabushiki Kaisha Aiden
    Inventor: Shigeru Ueki