Patent ID: 8883881

Claim:
A particulate superabsorbent polymer comprising: a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers comprising acrylic acid neutralized with an alkali hydroxide to from 50 to 80 mol %; b) from about 0.001 to about 5.0% by weight of internal crosslinking agent based on the weight of a); wherein elements a) and b) are polymerized, dried to have a final product moisture content of less than 5 wt %, and comminuted into a particulate gel having a particle size of from 150 microns to about 850 microns; wherein the particulate superabsorbent polymer further comprise a crosslinked surface comprising: c) from about 0.01 to about 3.0% by weight of surface crosslinking agent applied to the particle surface based on dry polymer powder weight; and d) from about 0.01 to 0.5% by weight of a thermoplastic polymer based on dry polymer powder weight, wherein said thermoplastic polymer has a thermoplastic melt temperature wherein the thermoplastic polymer is applied on the particle surface coincident with, or followed by a temperature at least about the thermoplastic melt temperature, and wherein the thermoplastic polymer is either added to the particulate superabsorbent polymer with the surface crosslinking agent c) or applied to the particulate superabsorbent polymer before the surface crosslinking agent c) is added to the particulate superabsorbent polymer, wherein the thermoplastic polymer is part of the surface crosslinked portion of the particulate superabsorbent polymer wherein said particulate superabsorbent polymer has a gel bed permeability II of from about 300×10 −9 to about 1000×10 −9 cm 2 .