Preparation of ultrapure N-vinylpyrrolidone polymers

US5354945A · kind A · utility

Assignee

• BASF SE

Inventors

• Juergen Detering · Schifferstadt, DE
• Hartwig Voss · Bischofswerda, DE

Key dates

• Filing date: Nov 30, 1992
• Grant date: Oct 11, 1994
• Expiry date: Nov 30, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S210/908
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for preparing ultrapure polymers (or solutions thereof) which contain at least 20% by weight of N-vinylpyrrolidone as copolymerized units and have a Fikentscher K value of from 10 to 45 by customary free-radical polymerization in solution and subsequent purification of the solution with or without drying comprises purifying the solutions of the polymers by separating off the low molecular weight impurities by means of ultrafiltration at from 20.degree. to 100.degree. C. and from 1 to 80 bar.