Patent ID: 6174929
Filing Date: 2001-01-16
Classification: A61L,C05G,C08J

Abstract:
A process for preparing water-absorbing foamlike crosslinked polymers, which comprises foaming a polymerizable aqueous mixture of(a) monoethylenically unsaturated monomers containing acid groups, which are at least 50 mol % neutralized,(b) with or without other monoethylenically unsaturated monomers,(c) crosslinkers,(d) with or without one or more polymerization initiators,(e) from 0.1 to 20% by weight of at least one surfactant,(f) with or without one or more solubilizers and(g) with or without thickeners, foam stabilizers, polymerization regulators, fillers and/or cell nucleating agentsin a first process stage by dispersing fine bubbles of a gas inert to free radicals and polymerizing the resulting foam in a second process stage with formation of a foamed hydrogel, the polymerization being started by contact heating and/or irradiating with light from the UV/visible region a layer of the foamed mixture on both surfaces.