Alkylation of cross-linked polymers containing N- or amine or ammonium groups

The invention relates to a method for alkylating cross-linked polymers containing N- or amino, ammonium or spiro-bicyclic ammonium groups. According to said method, the gelated polymers, obtained by polymerization and cross-linking, are a) optionally, deprotonated in water, an organic solvent or in a mixture of an organic solvent and water, by adding a base, b) optionally, washed once or more with water, an organic solvent or a mixture of an organic solvent and water, then c) one or more alkylators are added to the gel suspension which is stirred in water, an organic solvent or in a mixture of an organic solvent and water, at a temperature of between 5 and 160° C. at normal or increased pressure, with a base being added after a short mixing time and d) reprotonation is carried out using a mineral acid, optionally after one or more washing steps, resulting in the alkylated, cross-linked polymers containing N- or amino, ammonium or spirobicyclic ammonium groups, accordingly.