Process for preparing monodisperse cation-exchanger gels

Abstract

The invention relates to a process for preparing monodisperse cation-exchanger gels with increased oxidation resistance and with high osmotic stability and purity by (a) polymerizing monodisperse microencapsulated monomer droplets made from a monomer mixture (1) comprising from 90.5 to 97.99% by weight of styrene, from 2 to 7% by weight of divinylbenzene, and from 0.01 to 2.5% by weight of free-radical generator in aqueous suspension to conversions of from 76 to 100%, (b) adding a monomer mixture (2) made from 70.5 to 95.99% by weight of styrene, from 4 to 15% by weight of divinylbenzene, from 0 to 12% by weight of a third comonomer, and from 0.01 to 2.5% by weight of one or more free-radical generators to form a copolymer, wherein a portion of from 50 to 100% by weight of the monomer mixture (2) is added under polymerization conditions in which at least one free-radical generator from monomer mixture (2) is active, and (c) functionalizing the reaction product from process step (b) by sulfonation.

Dependencies are inferred from the claim text.