Patents by Inventor Akihiro Kotsugai

Akihiro Kotsugai 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).

  • Method of preparing composite particles comprising adhering wax particles to the surface of resin particles
    Patent number: 5368972
    Abstract: A method of preparing composite particles is disclosed, which comprises the steps of dispersing matrix organic resin particles having a polar group on a surface thereof in a hydrophilic organic liquid, water or mixture thereof to prepare a dispersion of the matrix organic resin particles; dispersing a wax in a hydrophilic organic liquid, water or mixture thereof by use of a nonionic surface active agent to prepare an emulsion of the wax; mixing the dispersion of the matrix organic resin particles and the emulsion of the wax in the presence of a surface active agent with a polarity opposite to that of the polar group on the matrix organic resin particles to obtain a dispersion in which finely-divided particles of the wax are caused to adhere to the surface of the matrix particles; and heating the dispersion to fix the finely-divided particles of the wax on the surface of the matrix organic resin particles.
    Type: Grant
    Filed: February 11, 1993
    Date of Patent: November 29, 1994
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Yamashita, Akihiro Kotsugai, Yoichiro Watanabe, Koichi Katoh, Hiromitsu Kawase