Patents by Inventor Shigenori Shirouzu

Shigenori Shirouzu 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).

  • Optical disk substrate comprising aromatic polycarbonate
    Patent number: 4923962
    Abstract: A resin material for optical instruments comprising a polycarbonate having the repeating units represented by the following general formula: ##STR1## wherein X represents ##STR2## has an extremely small birefringence particularly to oblique-incident lights.
    Type: Grant
    Filed: October 12, 1988
    Date of Patent: May 8, 1990
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Kazuyoshi Shigematsu, Shigenori Shirouzu, Shuji Sakamoto, Toshiyasu Suzuki
  • Polyformal resin and process for producing said resin
    Patent number: 4801679
    Abstract: Polyformal resins having a repeating unit represented by the general formula: ##STR1## wherein the symbols are as defined in the appended claims and an intrinsic viscosity at 20.degree. C. as a methylene chloride solution of at least 0.2 dl/g, and a process for efficiently producing the polyformal resins. The present polyformal resins are excellent in heat resistance and optical properties, and thus are useful as materials for production of optical instruments, for example.
    Type: Grant
    Filed: January 20, 1988
    Date of Patent: January 31, 1989
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Kazuyoshi Shigematsu, Shigenori Shirouzu