Patents by Inventor Katsunosuke Kitagawa

Katsunosuke Kitagawa 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 separating surfactants from liquid used in the manufacture of concentrated fluoropolymer dispersions
    Patent number: 4639337
    Abstract: A process for separating the ammonium salt of a selected fluoroalkanoic acid and a selected hydrocarbyl oxyethoxylatedpolyether from aqueous dross liquor which comprises:A. extracting the ammonium salt (in the form of its corresponding acid) and the ethoxylated compound from an acidified aqueous dross liquor by agitating with a selected organic liquid and separating the organic liquid layer,B. (1) contacting said organic liquid layer with activated alumina,(2) washing and drying the alumina and contacting it with ammonium hydroxide,C. boiling the organic liquid obtained in step B1 until the ethoxylated compound remains.
    Type: Grant
    Filed: March 14, 1985
    Date of Patent: January 27, 1987
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Charles S. Cope, Katsunosuke Kitagawa, Kazuo Konabe