The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 23, 2010
Filed:
May. 22, 2007
David William Johnson, Washington, WV (US);
Robert John Cavanaugh, Cincinnati, OH (US);
David William Johnson, Washington, WV (US);
Robert John Cavanaugh, Cincinnati, OH (US);
E.I. du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A process for reducing fluorosurfactant content of a fluorosurfactant-containing aqueous fluoropolymer dispersion stabilized with nonionic surfactant. The process includes reducing the fluorosurfactant content of the stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion to a predetermined level to provide a reduced surfactant dispersion, adding non-fluorinated anionic surfactant to the reduced fluorosurfactant dispersion, and concentrating the reduced fluorosurfactant dispersion. The non-fluorinated anionic surfactant is added in stages wherein a first portion is added to the dispersion prior to concentrating and a second portion of the non-fluorinated anionic surfactant is added to the dispersion after concentrating.