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:
Nov. 06, 1990
Filed:
Sep. 01, 1989
Heinz-Joachim Muller, Worth, DE;
Friedbert Wechs, Worth, DE;
Akzo N.V., Arnhem, NL;
Abstract
A process produces microporous powders or shaped articles, in particular membranes in the form of flat films, tubular films or hollow fibers, which may be used for controlled release of an active compound, for dialysis, gas separation, ultrafiltration or microfiltration, from polyvinylidene fluoride and/or polyphenylene sulfide and/or polysulfone and/or polyacrylonitrile and/or ethylene/vinyl alcohol copolymer and/or ethylene/chlorotrifluoroethylene copolymer and/or polyethersulfone and/or polyether-imide and/or polymethyl methacrylate and/or polycarbonate and/or cellulose triacetate. The process utilizes phase separation by means of thermally induced triggering or triggering induced by a non-solvent of a solution of the polymer in a mixture containing .epsilon.-caprolactam as the essential dissolving constituent. The solution may be formed before the phase separation is triggered.