Patents by Inventor Kazuko Hirahara

Kazuko Hirahara 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).

  • Heat-sensitive recording material
    Patent number: 4761396
    Abstract: In a heat-sensitive recording material comprising a colorless or pale-colored basic dye and an electron accepting reactant material which is reactive with the basic dye to form a color when contacted therewith, and comprising at least one of the specific phthalide derivatives as the basic dye, the heat-sensitive recording material characterized in that at least one compound selected from the group consisting of the specific fluorene derivatives and the specific p-phenylenediamine derivatives is further contained in the recording material.
    Type: Grant
    Filed: February 5, 1987
    Date of Patent: August 2, 1988
    Assignee: Kanzaki Paper Manufacturing Co., Ltd.
    Inventors: Nobuo Kanda, Kazuko Hirahara, Mitsuru Kondo