Patents by Inventor Minoru Hamada

Minoru Hamada 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 preventing color migration in colored moldings of polyoxymethylene resins
    Patent number: 4331439
    Abstract: This invention deals with the coloring or dyeing of polyoxymethylene resins and particularly with preventing color migration therein. Color migration in molded articles of colored polyoxymethylene resins is prevented by dyeing the articles with disperse dyes, and treating the articles with a compound having one or more isocyanate groups, for example, a urethane prepolymer.
    Type: Grant
    Filed: December 19, 1980
    Date of Patent: May 25, 1982
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Minoru Hamada, Hisaya Sakurai, Jyunzo Masamoto, Takeo Yoshida, Hiroshi Hazawa