MODIFIED RIGID, FOAMABLE URETHANE COMPOSITION AND METHOD

摘要

A polyurethane composition to provide a rigid polyurethane foam suitable for use as a core material in a composite laminate and which polyurethane composition includes an additive compound or oligomer-prepolymer having hydroxy groups for reaction with the diisocyanate of the polyurethane or whi ch has been prereacted with a diisocyanate and which contains after the polyurethane reaction ethylenically unsaturated groups, like allyl or acryli c groups, to react with an unsaturated polyester resin. The invention includes the organic additive oligomer-prepolymer and the hybrid polyester-rigid polyurethane laminates.