Patent ID: 7285614
Filing Date: 2007-10-23
Classification: A61L

Abstract:
1. A hydrophilic superabsorbent polymer composition comprising an absorbent polymer that is the reaction product of: a) from about 55 to about 99.9 wt. % based on the absorbent polymer of polymerizable unsaturated acid group containing monomers; b) a first neutralizing agent selected from monovalent hydroxides, monovalent carbonate, or monovalent bicarbonate salts, or mixtures thereof; c) a second neutralizing agent comprising a multivalent metal hydroxide; d) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent; and e) an initiator for initiation of free-radical polymerization; wherein the absorbent polymer has a degree of neutralization of more than about 25%, and from about 20 mole % to about 75 mole % of the unsaturated acid group containing monomers are neutralized with the first neutralizing agent, and from about 5 mole % to about 40 mole % of the unsaturated acid group containing monomers are neutralized with the second neutralizing agent, at a temperature of about 75° C. or less, and the absorbent polymer is formed into an absorbent polymer particle which is surface treated with from about 0.001 to about 5.0 wt. % of surface crosslinking agent applied to the polymer particle surface; and wherein the hydrophilic superabsorbent polymer composition has an absorption time of about 5+10 a