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:
Apr. 23, 1991
Filed:
Oct. 23, 1989
Axel Walch, Frankfurt am Main, DE;
Juergen Wildhardt, Huenstetten, DE;
Dieter Beissel, Wiesbaden, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
A process for preparing an asymmetrical macroporous membrane from a polymer solution comprised as the dissolved portion fraction a polymeric mixture comprised of about 5-70% by weight of polyvinylpyrrolidone having a molecular weight of .gtoreq.100,000 Dalton and about 95-30% by weight of a polymer selected from the group consisting of polysulfone, a polyether sulfone, and an aromatic or araliphatic polyamide, said weight being relative to the total weight of the dissolved polymeric fraction, by action of a coagulating liquid, wherein the coagulation is effected under conditions such that skin formation, asymmetrical port formation and retention of the polyvinylpyrrolidone are achieved, recovering the asymmetrical macroporous membrane comprising the polymeric mixture.