Patent ID: 8217092

Claim:
A multicomponent polyurethane/vinyl ester hybrid foam system for forming a gradient foam with soft and rigid foam regions, with a polyol component (A), which contains at least one polyol with a hydroxy functionality of at least 2, a catalyst for the reaction of the polyol with the polyisocyanate, a vinyl ester mixture including at least one polymerizable hydroxyvinyl ester and at least one branched, at least trifunctional, polymerizable vinyl ester, and water or a blowing agent based on a compressed or liquefied gas as foam-forming agent; a polyisocyanate component (B), which contains at least one polyisocyanate with an NCO functionality of at least 2; and a component (C), which contains a thermally activatable free radical-forming agent that is activated thermally at a temperature of 60° C. to 90° C. as a catalyst for the polymerization of the vinyl monomer, the component (C) present separately from the polyol component (A) and/or the polyisocyanate component (B) to inhibit reaction and reacting only when mixed, wherein the proportion by weight of the vinyl ester mixture in the polyol component (A) is greater than the proportion by weight of the at least one polyol in the polyol component (A) as well as the proportion by weight of the at least one polyisocyanate in the polyisocyanate component (B).