Patents by Inventor Hiroshi Takeguchi

Hiroshi Takeguchi 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).

  • Aromatic polycarbonate
    Patent number: 6255436
    Abstract: An aromatic polycarbonate of the present invention is produced by reacting an aromatic dihydroxy compound with a compound capable of introducing a carbonate bond, and has a viscosity-average molecular weight of 12,000 to 40,000 and a content of a cyclic oligomer represented by the formula (1) of not more than 1,000 ppm, in which the percentage of the content of said cyclic oligomer represented by the formula (1) based on the total contents of the cyclic oligomer represented by the formula (1), an oligomer represented by the formula (2) and an oligomer represented by the formula (3) satisfies the following relational formula [I]: 0 < ( 1 ) ( 1 ) + ( 2 )
    Type: Grant
    Filed: November 22, 1999
    Date of Patent: July 3, 2001
    Assignees: Mitsubishi Chemical Corporation, Mitsubishi Gas Chemical Company, Inc.
    Inventors: Masatoshi Kimura, Michio Kawai, Hiroshi Takeguchi, Hiroshi Nakano, Masayuki Nakajima, Katsushige Hayashi