Patents by Inventor Toshiyuki Uemura

Toshiyuki Uemura 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).

  • Surface-treated organic pigment and process for the production thereof
    Patent number: 5928419
    Abstract: A surface-treated organic pigment excellent in initial dispersibility and long-term dispersion stability in water and an organic solvent and free from the coagulation of pigment particles, obtained by reacting a sulfonating agent with an organic pigment dispersed in a solvent in which the organic pigment is insoluble or sparingly soluble, and thereby introducing a sulfonic acid group to the surface of each particle of the organic pigment.
    Type: Grant
    Filed: October 6, 1997
    Date of Patent: July 27, 1999
    Assignee: Toyo Ink Manufacturing Co., Ltd.
    Inventors: Toshiyuki Uemura, Tsukasa Iguchi, Sunao Satake, Hisashi Uraki, Yasuharu Iida
  • Hole-transporting material and use thereof
    Patent number: 5681664
    Abstract: Hole-transporting materials of the following formula (1) have excellent hole-transporting capability and excellent durability,H--A--?--B--A--!.sub.n --B--A--H (1)wherein A is an aromatic amine derivative residue of the following formula (2), B is a residue of the following formula (3), and n is an integer of 1 to 5,000,Formula (2): ##STR1## Formula (3): ##STR2## and the above hole-transporting materials therefore give an organic EL device and an electrophotographic photoreceptor which are excellent in stability in the continuous operation for a long period time.
    Type: Grant
    Filed: August 2, 1995
    Date of Patent: October 28, 1997
    Assignee: Toyo Ink Manufacturing Co., Ltd.
    Inventors: Michiko Tamano, Toshikazu Onikubo, Toshiyuki Uemura, Tadashi Ogawa, Toshio Enokida