Process for the preparation of very acidic cation exchangers

US6228896A · kind A · utility

Assignee

• IAB Ionenaustauscher GmbH Bitterfeld · DE

Inventors

• Reinhard Bachmann · Bad Kötzting, DE
• Lothar Feistel · Delitzsch, DE
• Rudiger Seidel · Sandersdorf, DE
• Karl-Heinz Siekiera · Wolfen, DE

Key dates

• Filing date: Jun 17, 1998
• Grant date: May 8, 2001
• Expiry date: Jun 17, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F2800/20
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the preparation of mechanically and osmotically stable, high-capacity strongly acidic cation exchangers having a particle size of .gtoreq.0.1 mm by sulphonation of gel-like or porous bead polymers with sulphuric acid without the use of inert chlorine-containing swelling agents and/or of comonomers based on acrylonitrile. According to the invention, such strongly acidic cation exchangers can be prepared by sulphonation of gel-like and porous bead polymers, prepared by copolymerization of styrene and divinylbenzene having a crosslinker content of up to 65% by weight of divinylbenzene with and without inert composition, with 80-96% strength sulphuric acid at temperatures of 125-180.degree. C. and a reaction time of up to 20 h. According to the novel process, strongly acidic cation exchangers can be prepared without the use of the inert chlorine-containing environmentally harmful swelling agent 1,2-dichloroethane, with quality features and material characteristics identical or similar to products produced by the conventional processes.