Bayer Aktiengesellschaft

Iab Ionenaustauscher Gmbh Bitterfeld

Iab Ionennaustauscher Gmbh Bitterfeld

Lothar Feistel

Karl-Heinz Siekiera

Reinhard Bachmann

R&uuml;diger Seidel

Kurt Wegewitz

Wolfgang Podszun

Alfred Mitschker

Olaf Halle

Gerold Schade

Claudia Schmid

Hubertus Mittag

The present invention relates to a process for producing monodisperse anion-exchanger gels with high stability, purity and coarse particle size greater than 800 &#x3bc;m starting from a monodisperse bead polymer with a swelling index of from 2.5 to 7.5 and more than one subsequent feed procedure without any separation between the polymerization steps and then modifying to give the anion exchanger.

Process for producing coarse-particle anion-exchanger gels

Process for the preparation of free-flowing strongly acidic cation exchangers

Sulfonated strongly acidic cation exchangers are rendered free-flowing by treatment with wetting agents or water soluble initiators, washing with water at temperatures of at least 60&deg; C. and heat drying.

The invention relates to a process for preparing substantially monodisperse crosslinked bead polymers useful as precursors for ion exchangers.

Process for preparing monodisperse crosslinked bead polymers

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 &gE;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&deg; 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.

Process for the preparation of very acidic cation exchangers

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Delitzsch, Germany

Lothar Feistel