Patents by Inventor Yayoi Yoshioka

Yayoi Yoshioka 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).

  • Functional polyamic acid microfine particles, functional polyimide microfine particles, and processes for their production
    Patent number: 6335418
    Abstract: A primary object of the invention is to provide a production technology for functional polyamic acid microfine particles and functional polyimide microfine particles by which the particle shape, size and size distribution can be freely controlled. The invention is concerned with a process for synthesizing polyamic acid particles having functional groups at least on the surface from a tetracarboxylic anhydride and a diamine compound characterized by its comprising (a) a first step which comprises providing a tetracarboxylic anhydride and a diamine compound at least one of which has functional groups and preparing a first solution containing the tetracarboxylic anhydride and a second solution containing the diamine compound and (b) a second step which comprises mixing the first and second solutions under ultrasonic agitation to thereby precipitate polyamic acid microfine particles from the mixed solution.
    Type: Grant
    Filed: August 18, 2000
    Date of Patent: January 1, 2002
    Assignees: Osaka Prefectural Government, Sumitomo Bakelite Co., Ltd.
    Inventors: Katsuya Asao, Hitoshi Morita, Hitoshi Onishi, Masaki Kimoto, Yayoi Yoshioka, Hidenori Saito