Patent ID: 8742026

Claim:
A process for producing water-absorbing polymer particles with improved permeability comprising i) polymerization of a monomer solution or suspension comprising a) at least one ethylenically unsaturated monomer which bears acid groups and optionally is at least partly neutralized, b) at least one crosslinker, c) at least one initiator, d) optionally one or more ethylenically unsaturated monomers copolymerizable with the monomers mentioned under a) and e) optionally one or more water-soluble polymers, ii) drying the resulting polymer gel, iii) grinding the dried polymer gel to give polymer particles, iv) classifying the polymer particles, and v) thermally surface postcrosslinking the classified polymer particles, wherein the polymer particles are pneumatically conveyed after step iii) and before step iv), and wherein an initial gas velocity in the pneumatic conveying corresponds to a Froude number of at least 20.