Method for producing water-swellable hydorphilic polymers, said polymers and use thereof

US6565768B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Joachim Dentler · Bruchköbel, DE
• Norbert Herfert · Charlotte, US
• Rudolf Schliwa · Alzenau, DE
• Uwe Stuven · Bad Soden, DE
• Fritz Engelhardt · Frankfurt am Main, DE

Key dates

• Filing date: Apr 6, 2001
• Grant date: May 20, 2003
• Expiry date: Apr 6, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S528/93
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Water-swellable hydrophilic polymers are prepared by neutralization of the acidic hydrogel having a degree of neutralization of 0-40 mol % to an ultimate degree of neutralization of 60-85 mol % by mixing with a neutralizing agent in a mincer comprising a system of screw, rotating blade, restricted flow zone and breaker plate, whereinthe mincer has a power output of from 1000 to 6000 Wh/m3 the hydrogel passes through a zone having-an energy dissipation density of from 400 to 800 W/1 of mixing volumethe average residence time of the hydrogel in the mincer is from 5 to 30 secondsthe breaker plate has an open area of from 20 to 40%.