摘要 |
<p>The present invention provides an improved process for preparing a highly water absorbent resin having a superior suction power and excellent gel strength, which comprises: (1) dehydrating a polymer, which is prepared by partially neutralizing monomers or polymers containing a carboxyl or carboxylate group and polymerizing them, by using an azeotropic distillation method in the presence of a lipophilic solvent; (2) crosslinking the dehydrated polymer in the presence of a hydrophilic crosslinking agent and dehydrating the crosslinked polymer by using an azeotropic distillation method; and (3) filtering and drying the reaction products to recover the crosslinked polymer, wherein the improvement comprises: (a) in step(1), the polymer is dehydrated until it has a water content of 25% by weight or less based on the weight of the polymer; and, (b) in step(2), water is employed to penetrate the hydrophilic crosslinking agent into the intraparticle in an amount ranging from 7.0 to 25.0% by weight based on the weight of the polymer, for the crosslinking process and an amount of 60% by weight or more based on the added amount of water is removed from the crosslinked polymer during the dehydration process.</p> |