Patent ID: 7812082
Filing Date: 2010-10-12
Classification: A61L,C08J,C08L,C09D,Y10T

Abstract:
1. Thermoplastic polymer treated superabsorbent polymer particles comprising a superabsorbent polymer composition comprising a superabsorbent polymer comprising: a) from about 55 to about 99.9% by weight of the superabsorbent polymer of polymerizable unsaturated acid group containing monomer based on the superabsorbent polymer; and b) from about 0.001 to about 5% by weight of internal crosslinking agent based on the polymerizable unsaturated acid group containing monomer; wherein the superabsorbent polymer has a degree of neutralization of greater than about 25%; wherein elements a) and b) are polymerized and prepared into superabsorbent polymer particles further comprising the following surface additives to form surface treated superabsorbent polymer particles i) from about 0.001 to about 5% by weight of surface crosslinking agent based on the dry superabsorbent polymer composition; ii) from about 0.01 to about 10% by weight of the dry superabsorbent polymer composition of a penetration modifier selected from polyethylene glycols, tetraethylene glycol dimethyl ether, monovalent metal salts, surfactants, water soluble polymers, thermoplastic resins or blends thereof; iii) from 0 to about 5% by weight of a multivalent metal salt based on the dry superabsorbent polymer composition; iv) from 0 to about 2% by weight of a surfactant based on the dry superabsorbent polymer composition; v) from about 0.01 to about 1% by weight of an insoluble, inorganic powder based on the dry superabsorbent polymer composition; and vi) from about 0.01 to about 1% by weight of a thermoplastic polymer based on the dry superabsorbent polymer composition, wherein the thermoplastic polymer is a surface additive deposited on the superabsorbent polymer particles to form thermoplastic polymer treated superabsorbent polymer particles, wherein the thermoplastic polymer surface treated superabsorbent polymer particles are heat treated wherein the thermoplastic polymer of vi) is applied to the superabsorbent polymer particles prior to the heat treatment; and wherein the thermoplastic polymer surface treated superabsorbent polymer particles are sized in the range of from about 300 to about 600 microns, wherein the superabsorbent polymer particles further comprise a coating of from about 0.1 to about 5% by weight of a cationic polymer selected from poly(vinyl amines), poly(allylamines), poly(ethylene imine), poly(amino propanol vinyl ethers), poly(acrylamidopropyl trimethyl ammonium chloride), poly(diallyldimethyl ammonium chloride), partially deacetylated chitin, chitosan, polyasparagins, polylysines, polyglutamines, polyarginines, including salts thereof, based on the dry superabsorbent polymer composition, and wherein the thermoplastic polymer surface treated superabsorbent polymer particles exhibit a centrifuge retention capacity of at least about 23 g/g as measured by the Centrifuge Retention Capacity Test; a free swell gel bed permeability of at least 100 Darcy as measured by the Free Swell Gel Bed Permeability Test; and superabsorbent polymer composition shake-out of less than about 20% as measured by the Oven Shake-Out Procedure.