Patents by Inventor Hitoshi Ishigaki

Hitoshi Ishigaki 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).

  • Acrylamide polymers and use thereof
    Patent number: 5942573
    Abstract: Provided by this invention are an acrylamide polymer which has a weight-average molecular weight (a) of from 1,500,000 to 10,000,000 and a weight-average inertial radius (b) of from 30 to 150 nm, the ratio (b)/(a) of the weight-average inertial radius (b) to the weight-average molecular weight (a) being 0.00004 or smaller; and an aqueous solution of an acrylamide polymer which solution has a polymer concentration ranging from 22 to 60%, a Brookfield viscosity at 25.degree. C. of 50,000 cps or smaller and a weight-average molecular weight of from 500,000 to 10,000,000. They are useful as paper strength agents.
    Type: Grant
    Filed: June 24, 1997
    Date of Patent: August 24, 1999
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Hirotoshi Doki, Hitoshi Ishigaki, Toshiki Oyanagi, Tsugio Matsubara, Shigeo Watanabe
  • Acrylamide polymers and use thereof
    Patent number: 5627249
    Abstract: Provided by this invention are an acrylamide polymer which has a weight-average molecular weight (a) of from 1,500,000 to 10,000,000 and a weight-average inertial radius (b) of from 30 to 150 nm, the ratio (b)/(a) of the weight-average inertial radius (b) to the weight-average molecular weight (a) being 0.00004 or smaller; and an aqueous solution of an acrylamide polymer which solution has a polymer concentration ranging from 22 to 60%, a Brookfield viscosity at 25.degree. C. of 50,000 cps or smaller and a weight-average molecular weight of from 500,000 to 10,000,000. They are useful as paper strength agents.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: May 6, 1997
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Hirotoshi Doki, Hitoshi Ishigaki, Toshiki Oyanagi, Tsugio Matsubara, Shigeo Watanabe