Patents by Inventor Sengo Ishizuka

Sengo Ishizuka 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).

  • Phthalocyanine pigment compositions
    Patent number: 4088507
    Abstract: A copper phthalocyanine pigment composition consisting essentially of 100 parts by weight of copper phthalocyanine and 0.5 - 30 parts by weight of a copper phthalocyanine derivative having the following formula ##STR1## WHEREIN Cu--Pc-- is the residue of copper phthalocyanine, m and n are each an integer of 1 - 4, and R.sub.1 and R.sub.2 are each a substituted or non-substituted alkyl group or a heterocyclic group containing the nitrogen atom appearing in the formula.
    Type: Grant
    Filed: April 27, 1977
    Date of Patent: May 9, 1978
    Assignee: Toyo Ink Manufacturing Co., Ltd.
    Inventors: Tuneo Tanaka, Sengo Ishizuka, Keniti Tokuda, Akimitsu Suzuki
  • Pigment compositions
    Patent number: 3973981
    Abstract: A non-crystallizing and non-flocculating pigment composition comprising as the base material a base organic pigment sch a phthalocyanine and as the additive a specified derivative of a starting organic pigment such as phthalocyanine.
    Type: Grant
    Filed: December 30, 1974
    Date of Patent: August 10, 1976
    Assignee: Toyo Ink Manufacturing Co., Ltd.
    Inventors: Masayuki Miyatake, Sengo Ishizuka, Takao Takagi