Stabilization of dilute aqueous solutions of high molecular weight homopolymers and copolymers based on water-soluble ethylenically unsaturated compounds

US4581405A · kind A · utility

Assignee

• BASF SE

Inventors

• Franz-Dieter Martischius · Neustadt, DE
• Wilfried Heide · Freinsheim, DE

Key dates

• Filing date: Sep 24, 1984
• Grant date: Apr 8, 1986
• Expiry date: Sep 24, 2004

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S507/936
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

Dilute aqueous solutions of high molecular weight polymers of acrylamide or methacrylamide or of homopolymers or copolymers of salts of ethylenically unsaturated C.sub.3 -C.sub.5 -carboxylic acids are stabilized to thermal degradation by adding (a) at least 20 ppm of an inorganic sulfur compound, in which the sulfur has an oxidation number of +2 to +5, and (b) at least 20 ppm of a complexing agent for metal ions.