Solutions of perfluorinated polymers in SF.sub.6 with or without CO.sub.2

US5696195A · kind A · utility

Assignees

• E.I. DU PONT DE NEMOURS AND COMPANY · US
• THE JOHNS HOPKINS UNIVERSITY · US

Inventors

• William H. Tuminello · Newark, US
• Mark A. McHugh · Baltimore, US
• Cynthia Asli Mertdogan · Parkersburg, US

Key dates

• Filing date: Jun 4, 1996
• Grant date: Dec 9, 1997
• Expiry date: Jun 4, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2327/18
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

Perfluorinated polymers are dissolved in supercritical carbon dioxide and/or sulfur hexafluoride at elevated temperatures and pressures. The solutions are useful for making foams, spun-bonded or paper-like webs, or for purification of polymers.