Patents by Inventor Shuji Tsukahara

Shuji Tsukahara 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).

  • Method of coloring polycarbonate extruded or molded products for optical members
    Patent number: 5116547
    Abstract: A method of coloring a polycarbonate extruded or molded product for optical members, which is colored by a liquid coloring process for obtaining a colored polycarbonate extruded or molded product for optical members by extrusion or injection molding. The process involves mixing a polycarbonate resin for optical members and a liquid coloring agent dispersion obtained by dispersing a coloring agent in a dispersing agent. The dispersing agent includes a specific saturated fatty acid ester or silicon oil. After mixing the polycarbonate resin and liquid coloring agent dispersion, the resulting mixture is melted and thereafter extruded or molded to form a product for optical members.
    Type: Grant
    Filed: July 20, 1990
    Date of Patent: May 26, 1992
    Assignees: Mitsubishi Gas Chemical Co., Victor Company of Japan, Ltd.
    Inventors: Shuji Tsukahara, Toshikazu Umemura, Kazuyoshi Ichise