Permselective membrane and use

US4229291A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Axel Walch · Baldham, DE
• Jurgen Wildhardt · Wallrabenstein, DE
• Dieter Beissel · Wiesbaden, DE

Key dates

• Filing date: Nov 20, 1978
• Grant date: Oct 21, 1980
• Expiry date: Nov 20, 1998

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D71/56
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Disclosed is a specific polyamide membrane suitable for hemofiltration, comprising a permselective asymmetric membrane of heteroporous structure comprising a polyamide which comprises a plurality of recurring terephthaloyldiamine units. The membrane has an ultrafiltration capacity of from about 1.5.SM.10.sup.-3 to about 15.multidot.10.sup.-3 cm/s.multidot.bar, determined for water at 0.1 bar and 20.degree. C., a thickness of not more than about 100 microns, and a molecular weight exclusion limit of from about 20,000 to about 70,000 Dalton. The membrane is produced in a process which comprises introducing a solution of the polyamide in a water-miscible organic solvent into an aqueous precipitating liquid to obtain a coagulated membrane sheet, which is subsequently washed and dried.