Highly absorbent polyurethane foam

Abstract

A highly hydrophilic polyurethane article, which is the skeletal network of a cellular polyurethane foam subjected to a reticulation process wherein the polyurethane contains up to 100 parts of a superabsorbent material per hundred parts of polyol used in preparing the polyurethane, is useful in absorbing and holding large amounts of aqueous liquids is prepared by: (a) mixing a polyisocyanate, a polyol and a blowing agent with a finely divided superabsorbent material which is insoluble in a liquid which the material absorbs and which absorbs at least 15 times its weight of said liquid, (b) reacting the polyisocyanate, polyol and blowing agent under foaming conditions to produce a foam of polyurethane which cmprises a multitude of gas cells or bubbles within the polyurethane matrix, (c) curing said foam of polyurethane, forming a cellular structure with windows or membranes of solid polyurethanes present between gas cells or bubbles, (d) removing the windows or membranes by thermal reticulation thereby leaving the skeletal structure of the cured polyurethane; and said article is useful wherever high absorption and retention of large quantities of aqueous liquids is needed, including diapers, surgical sponges, and so forth.

Dependencies are inferred from the claim text.