Patents by Inventor Isao Akihara

Isao Akihara 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).

  • Water-in-oil emulsion process for producing an aromatic polycarbonate
    Patent number: 5047497
    Abstract: A process for producing an aromatic polycarbonate in a water-in-oil emulsified form, having an improved heat stability during molding at a high temperature, is described. In the process according to the present invention, a tertiary amine is added to the water-to-oil emulsion after the average diameter of liquid droplets of the water phase is reduced to not more than 10.mu.m. The polycarbonate obtained by the process of the present invention is improved in heat stability and can provide a molded article with less coloration.
    Type: Grant
    Filed: April 9, 1990
    Date of Patent: September 10, 1991
    Assignee: Mitsubishi Kasei Corporation
    Inventors: Mitsuhiko Tamura, Isao Akihara
  • Preparation with controlled amounts of polycarbonate carbon tetrachloride
    Patent number: 4839458
    Abstract: Disclosed herein is a process for producing a resin having carbonate bonding, comprising polymerizing a hydroxydiaryl compound and phosgene in an organic solvent of methylene chloride such that the concentration of carbon tetrachloride in phosgene and methylene chloride in the polymerization system satisfies the following equation:A+5B.ltoreq.200(wherein A represents carbon tetrachloride concentration (ppm) in phosgene and B represents carbon tetrachloride concentration (ppm) in methylene chloride).
    Type: Grant
    Filed: June 17, 1987
    Date of Patent: June 13, 1989
    Assignee: Mitsubishi Chemical Industries Ltd.
    Inventors: Shinichiro Koga, Akira Matsuno, Katsuyuki Sakata, Yoshiaki Ohtani, Isao Akihara