Patent ID: 6914099

Claim:
A process for the preparation of water-absorbent resin particles, the process comprising: (I) polymerizing a polymerization mixture comprising: (a) one or more ethylenically unsaturated carboxyl-containing monomers, (b) one or more crosslinking agents, (c) optionally one or more comonomers copolymerizable with the carboxyl-containing monomer, and (d) a polymerization medium, to form a crosslinked hydrogel, (II) contacting the crosslinked hydrogel with a peroxodisulfate salt, (III) comminuting the hydrogel to particles prior to or after the peroxodisulfate salt is added in step (II), and (IV) drying the hydrogel to form resin, wherein step (II) is conducted in the substantial absence of a combination of surfactant and a material capable of adding across or reacting with a vinylic double bond so as to form reaction products which are incapable of vinylic polymerization via free radical initiation.