Patent · US Active

Staged addition of non-fluorinated anionic surfactant to reduced fluorosurfactant fluoropolymer dispersion

US7666928B2 · kind B2 · utility

1Cited by

21References

16Claims

0Family size

Assignee

E.I. DU PONT DE NEMOURS AND COMPANY · US

Inventors

David W. Johnson · San Diego, US
Robert John Cavanaugh · Cincinnati, US

Key dates

Filing date	May 22, 2007
Grant date	Feb 23, 2010
Priority date	—
Expiry date	Jan 25, 2028

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08J2327/12
WIPO fieldOther special machines
WIPO sectorMechanical engineering

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.