Patents by Inventor Masaharu Okawa

Masaharu Okawa 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).

  • Preparation of polymeric materials disintegratable by ultraviolet light
    Patent number: 3969432
    Abstract: A process for preparing vinyl aromatic resin-, e.g. styrene-,based resinous materials to render them brittle and disintegratable upon prolonged exposure to ultraviolet light while retaining, in the absence of ultraviolet light, substantially the same appearance, processability and mechanical properties of conventional vinyl aromatic resin-based materials, comprising copolymerizing said vinyl aromatic monomer with from 0.5 to 6.0% of a conjugated diene monomer, e.g. isoprene, based on the total weight of the two monomers, initially copolymerizing said vinyl aromatic monomer with only a portion of the total amount of conjugated diene monomer and then completing the copolymerization with the remainder thereof, and the polymeric resin obtained by said process.
    Type: Grant
    Filed: June 27, 1974
    Date of Patent: July 13, 1976
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Shigenori Togami, Masaharu Okawa, Junji Hara, Masami Tsuruta