Patents by Inventor Yuuji Hirasawa

Yuuji Hirasawa 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).

  • Pigment dispersing agent and pigment composition containing the same
    Patent number: 6123763
    Abstract: A colorless or only slightly colored pigment dispersing agent which is feasible as a pigment dispersing agent for pigments having various hues and has the general formula (1), ##STR1## wherein R.sub.1, R.sub.2, X.sub.1, Y.sub.1, Y.sub.2, k and h are as defined in claim 1.
    Type: Grant
    Filed: January 20, 1999
    Date of Patent: September 26, 2000
    Assignee: Toyo Ink Mfg. Co., Ltd.
    Inventors: Takashi Kamikubo, Yuuji Hirasawa, Toru Omura
  • Monoazo lake pigment suitable for use in printing ink and process for the production thereof
    Patent number: 5286287
    Abstract: A monoazo lake pigment and a process for its production; the monoazo lake pigment excellent in clearness, transparency, gloss and tinting strength is obtained by coupling a diazo component which is an aromatic amine having a sulfonic acid group with a coupler component which contains .beta.-naphthol or .beta.-oxynaphthoic acid and adding a laking agent during or after the coupling reaction, the coupler component further containing 0.1 to 30 mol %, based the coupler component, of a compound of the following formula, ##STR1## wherein n=1 or 2.
    Type: Grant
    Filed: September 9, 1992
    Date of Patent: February 15, 1994
    Assignee: Toyo Ink Manufacturing Co., Ltd.
    Inventors: Yuuji Hirasawa, Akimitsu Mochizuki
  • Microphone
    Patent number: D967076
    Type: Grant
    Filed: September 6, 2019
    Date of Patent: October 18, 2022
    Assignee: SONY GROUP CORPORATION
    Inventors: Hiromi Iizuka, Yuuji Hirasawa, Yohei Sakuraba