Patents by Inventor Tatuo Ishiki

Tatuo Ishiki 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).

  • Solid writing material
    Patent number: 3957495
    Abstract: A writing material in solid form containing a solid vehicle in which is dispersed a non-volatile oily solvent containing electron a substantially colorless donative chromogenic compound which develops color upon contact with an electron accepting substance, more than 50 % by weight of the solid vehicle being an ester of a higher (hydroxy) fatty acid or a mixture comprising an ester of a higher (hydroxy) fatty acid and a microcrystalline wax, and the non-volatile oily solvent being contained in the writing material in a range of from 10 to 50 % by weight of the entire writing material.
    Type: Grant
    Filed: May 24, 1974
    Date of Patent: May 18, 1976
    Assignee: Pilot Man-Nen-Hitsu Kabushiki Kaisha
    Inventors: Takeshi Teranishi, Tatuo Ishiki, Kunio Kosaki