Patent ID: 7850882

Claim:
A method of making layered integrated shaped product containing dimensionally stable hydrophilic polyurethane foam which comprises: a) casting onto a surface an aqueous reaction mixture containing a urethane pre-polymer containing free isocyanate groups and, optionally, a dimensional control ingredient in a ratio effective to produce a dimensionally stable foam of desired firmness when cured thereby producing a first layer of uncured polyurethane foam and compressing said first layer; b) distributing a composition containing an absorbent or a working ingredient that releases over time when exposed to a solvent fluid onto said first layer of uncured polyurethane; c) thereafter further adding a second layer of uncured polyurethane on said first layer and compressing the resulting uncured layered mass, d) curing the layered mass to produce a resulting layered integrated shaped product of dimensionally stable hydrophilic polyurethane foam containing a core region enriched in an absorbent or a working ingredient that releases over time when exposed to a solvent fluid; wherein said composition contains a working ingredient comprising a water soluble polymer selected from the group consisting of polyethylene oxide, polyvinyl pyrrolidone, polyacrylamide, hydroxypropyl cellulose, polyvinyl imidazoline, and polyhydroxyethylmethacrylate, and co-polymers and mixtures of said polymers; and said composition containing a water soluble polymer is in the form of a powder having a particle size between about 10 and about 300 mesh.