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:
Aug. 05, 1997
Filed:
May. 15, 1995
Arthur Zenker Moss, Wilmington, DE (US);
Martin Gerald Wagner, Wilmington, DE (US);
Raymond Richard Zolandz, Wilmington, DE (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
This invention relates to methods for preparing membranes of polyfluoroethylene (PTFE) and to the asymmetric membranes fabricated thereby. Such membranes are useful as separation and ultrafiltration membranes. The membranes are produced as a single layer. Method steps including contacting a substrate with a solution of PTFE in a perfluorinated cycloalkane solvent at a high temperature to cause a film of such solution to be coated on the substrate, removing the coated substrate from the solution and rapidly cooling it by contact with a second solvent, removing the coated substrate from the second solvent, drying the film, and optionally separating film from substrate.