Patent ID: 7462286

Claim:
A method for producing an ion exchanger which comprises carboxyl groups and —(CH 2 ) m NR 1 R 2 groups, comprising the steps of: a) reacting monomer droplets of a mixture of a monovinyl aromatic compound, a polyvinyl aromatic compound, a (meth)acrylic compound, and an initiator or an initiator combination, thereby, forming a crosslinked bead polymer, and b) functionalizing the crosslinked bead polymer using chelating groups and reacting, in this functionalizing step, the copolymerized (meth)acrylic compounds to form (meth)acrylic acid groups, where m is an integer from 1 to 4, R 1 is hydrogen or a radical CH 2 —COOR 3 or CH 2 P(O)(OR 3 ) 2 or —CH 2 —S—CH 2 COOR 3 or —CH 2 —S—C 1 —C 4 -alkyl or —CH 2 —S—CH 2 CH(NH 2 )COOR 3 or or its derivatives or C═S(NH 2 ), R 2 is a radical CH 2 COOR 3 or CH 2 P(O)(OR 3 ) 2 or —CH 2 —S—CH 2 COOR 3 or —CH 2 —S—C 1 C 4 -alkyl or —CH 2 —S—CH 2 CH(NH 2 )COOR 3 or or its derivatives or C═S(NH 2 ) and R 3 is H or Na or K.