Method of producing dialyzing membrane

US4164437A · kind A · utility

Assignee

• Akzo N.V. · NL

Inventors

• Werner Henne · Wuppertal, DE
• Gustav Dunweg · Wuppertal, DE
• Werner Schmitz · Wuppertal, DE
• Raimund Pohle · Wuppertal, DE
• Friedrich Lawitzki · Wuppertal, DE

Key dates

• Filing date: Jun 23, 1977
• Grant date: Aug 14, 1979
• Expiry date: Jun 23, 1997

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D69/147
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A dialyzing membrane, especially for hemodialysis, formed as a hollow fiber, tubular foil or flat sheet by regeneration of cellulose from a cuprammonium solution, the membrane comprising at least two firmly adhered cellulosic layers including at least one dialyzing layer consisting essentially of a semipermeable regenerated cellulose and at least one adsorbent layer consisting of said regenerated cellulose containing embedded therein fine particles of an adsorbent material in an amount of up to 95% by weight with reference to the dry weight of the adsorbent layer, preferably 1 to 90% and especially 20 to 70% by weight, when the adsorbent layer is part of a hollow fiber structure. The dialyzing membrane of the invention is produced by a method requiring at least two cuprammonium cellulose solutions, one of which is free of adsorbent particles and another of which contains a suspension of adsorbent particles, the different solutions being spun from adjacent spinning slots for immediate layer to layer contact and then introduced over a short air gap into a coagulating or precipitating bath to entrap the adsorbent particles in the spun layer in which the particles were originally suspe…