Patents by Inventor Haruhiro Hirai

Haruhiro Hirai 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).

  • Process for preparing large-sized polymer particles
    Patent number: 4694035
    Abstract: A process for preparing large-sized polymer particles having a particle diameter in a range of 0.1 to 500 .mu.m by seeded polymerization is described, comprising:finely dispersing a polymerizable monomer in an aqueous medium to prepare a monomer dispersion in which a number average particle diameter of the resulting monomer droplets is not larger than that of seed particles, and a number average particle diameter in a semi-stable condition (Dm) of the monomer droplets satisfies, with a desired number average particle diameter of the final polymer particle as D, the following relation:0.5.times.D<Dm<3.5.times.Dcombining said monomer dispersion with a dispersion of seed particles to make the polymerizable monomer absorbed or adsorbed on the seed particles; andpolymerizing the polymerizable monomer in the presence of a polymerization initiator.
    Type: Grant
    Filed: January 27, 1986
    Date of Patent: September 15, 1987
    Assignee: Japan Synthetic Rubber Co., Ltd.
    Inventors: Kiyoshi Kasai, Masayuki Hattori, Osamu Kikuchi, Hiromi Takeuchi, Haruhiro Hirai, Nobuo Sakurai