Process for the production of substantially closed-cell rigid foams containing urethane, urea and biuret groups showing excellent adhesion to solid surfaces and their use

摘要

Substantially closed-cell rigid foams containing urethane, urea and biuret groups are produced by reacting an NCO terminated prepolymer with a compound having at least two isocyanate-reactive hydrogen atoms and a molecular weight of from about 400 to about 10,000 in the presence of a catalyst and water by any of the known techniques. The NCO terminated prepolymer is the reaction product of x parts by weight of an at least difunctional polyol having an OH value of less than 100 with y parts by weight of an at least difunctional polyisocyanate. The ratio of x to y is at least 1:10. The product foams are particularly useful as insulating materials.