Asymmetrical ultrafiltration membrane on the basis of cellulose triacetate

US4253963A · kind A · utility

Assignee

• Sartorius AG · DE

Inventors

• Walter Franken · Eschweiler, DE
• Dieter Nussbaumer · Oettingen, DE
• Horst Perl · Göttingen, DE
• Ludwig Weickhardt · Bovenden, DE

Key dates

• Filing date: Apr 10, 1979
• Grant date: Mar 3, 1981
• Expiry date: Apr 10, 1999

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D2323/04
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

An asymmetrical ultrafiltration membrane based on cellulose triacetate, optionally substituted by up to 30% cellulose diacetate, is made wettable without tendency to embrittlement or shrinkage by adding hydrophobic synthetic silicic acid to the casting solution.