Semipermeable membranes of copolyamides

US4217227A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Klaus Elfert · Krefeld, DE
• Gerhard D. Wolf · Dormagen, DE
• Francis Bentz
• Hans Egon Kunzel

Key dates

• Filing date: Jun 29, 1978
• Grant date: Aug 12, 1980
• Expiry date: Jun 29, 1998

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G69/38
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The invention relates to semipermeable membranes with a water absorption capacity of from 4.5 to 10% by weight preferably from 4.5 to 8% by weight as measured on approximately 40.mu. thick symmetrical films at room temperature and 65% relative air humidity, with a throughflow of at least 80 1/m.sup.2 d for a desalination level of at least 85% and consisting of a fully aromatic copolyamide with a relative viscosity of .gtoreq.1,4, as measured on a 0.5% N-methyl pyrrolidone solution at a temperature of 20.degree. C.