Kimberly-clark Corporation

Gerard J Ring

Chad E Garvey

Jose F Pazos

Gerard M Aberson

An absorbent superwicking crosslinked polyurethane foam composition, into which is incorporated an effective amount of at least one amino acid, a one percent by weight aqueous solution of which has a pH of no more than about 8. The amino acid contains one amino group and at least one carboxylic acid group. A method for preparing such compositions also is described. The polyurethane foam composition is useful as a sponge and in the manufacture of such absorbent composite structures as disposable diapers, incontinent products, disposable bibs, feminine care products such as tampons and napkins, and the like.

Superwicking crosslinked polyurethane foam composition containing amino

A superabsorbent polyurethane foam which contains a plurality of polycarbonyl moieties covalently attached to the polyurethane through at least one urethane, thiourethane, or urea linkage. The carbonyl portions of such polycarbonyl moieties can be carbamoyl, substituted carbamoyl, or carboxy or the alkali metal or ammonium salts thereof. The foam can be prepared by mixing an isocyanate-terminated prepolymer with a first compound having at least one isocyanate-reactive group and at least one carbon-carbon double bond, allowing the mixture to react, and then mixing with the resulting product an aqueous solution of a carboxylate-containing second compound having at least one carbon-carbon double bond. A thermally activated free radical initiator is present in the final reaction mixture. Preferably, the polyurethane is derived from an isocyanate-terminated poly(oxyalkylene) polyol having an isocyanate functionality greater than two and the polycarbonyl moieties are derived from second compounds which typically are acrylate or methacrylate salts, i.e., alkali metal or ammonium salts of acrylic or methacrylic acid. The first compound usually is the 2-hydroxyethyl ester of acrylic or methacrylic acid. Such superabsorbent polyurethane foam is useful in the manufacture of absorbent articles, especially disposable absorbent articles such as diapers, sanitary napkins, bedpads, incontinent pads, and the like.

Process of making a crosslinked superabsorbent polyurethane foam

The invention comprises of an anionic polyelectrolyte hydrogel reversibly cross-linked with a polyvalent metal cation having a valence of at least two. This hydrogel may be combined with a removal agent for imparting delayed swelling characteristics when contacted with a water-containing fluid. The delayed swelling allows the water-containing fluid to penetrate or permeate the system before swelling is initiated, thereby providing enhanced wetting prior to the onset of swelling and alleviating gel blockage.

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Woodstock, GA, United States of America

Gerard J Ring