Process for the alkaline saponification of crosslinked acrylonitrile bead polymers

US7166645B2 · kind B2 · utility

Assignee

• LANXESS Deutschland GmbH · DE

Inventors

• Michael Happ · Scottsdale, US
• Dieter Irmscher · Bensberg, DE
• Wolfgang Podszun · Neunburg vorm Wald, DE
• Rudiger Seidel · Sandersdorf, DE
• Wolfgang Zarges · Neunburg vorm Wald, DE

Key dates

• Filing date: Apr 21, 2004
• Grant date: Jan 23, 2007
• Expiry date: Feb 14, 2025

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F2810/20
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The alkaline saponification of acrylonitrile bead polymers provides weakly acidic cation exchangers with little intrinsic color and with reduced residual nitrogen content if the saponification is begun at a temperature T1 of from 70 to 120° C. and, once a degree of saponification of at least 65% has been reached, is completed at a temperature T2 of from 120 to 180° C.