Highly swellable absorption medium with reduced caking tendency

A process for the production of an absorption medium with a reduced caking tendency in a moist environment and/or at high temperatures, comprising the steps of:

• providing a component I which is a water- or aqueous fluid-absorbing, dried, surface-cross-linked polymer particle based on polymerized monomers containing at least partially neutralized acid groups;
• surface coating component I with a coating agent selected from the group consisting of nitrogen-containing, non-ionic surfactants as component II and optionally a Lewis acid as component III;
• and heat-treating the mixture, wherein said surfactant has the general formula I:
• in which
• R1 is an aliphatic C1 to C30 hydrocarbon z-substituted aliphatic residue,
• R2 is selected from a hydrogen, an C2 to C24 aliphatic hydrocarbon residue, and a hydroxyalkylene residue
• R3, which may be identical or different, has the same meaning as R2, provided that with amide compounds, at least one of residues R2 or R3 represents a hydroxyalkylene residue or an alkoxylated hydroxyalkylene residue or a corresponding esterified or alkoxylated or esterified and alkoxylated hydroxyalkylene residue with the definition given for R2 above;
• n is 1;
• and z is a whole number from 1 to 4.