Surface crosslinked and surfactant coated absorbent resin particles and method of preparation

A process for the preparation of surface crosslinked absorbent resin particles which comprises

• A) contacting particles of a hydrogel of crosslinked carboxyl containing water-absorbent resins with a nonionic surfactant having an HLB of from 3 to 10, optionally in the presence of a composition comprising a polyhydroxy compound which is ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerol, polyglycerol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, propane diol butane diol, diethanolamine, triethanolamine, trimethylolpropane, pentaerythritol, sorbitol or mannitol, optionally water and optionally a water miscible polar solvent, under conditions such that the surfactant and optionally the polyhydroxy compound, coat the water-absorbent resin particles without significant penetration into the interior of the absorbent resin particles;
• B) drying the mixture of the hydrogel of the water-absorbent resin, and composition containing the surfactant and optionally the polyhydroxy compound, under conditions such that the water, and optional solvent if present, are removed and the surfactant and optionally the polyhydroxy compound does not significantly react with the carboxyl moieties of the water-absorbent resin;
• C) optionally, reducing the particle size of the dried coated absorbent resin by mechanical means;
• and
• D) heating the coated water-absorbent resin particles under conditions such that the surfactant and optionally the polyhydroxy compound react with the carboxy moieties of the water-absorbent resin so as to crosslink the surface of the water-absorbent resin particles.