Abstract: The invention relates to the use of silicone-polyether copolymers of the formula I ##STR1## as surface-active substances in the production of high-resilience polyurethane foams.

Abstract: High resilience polyurethane foams are produced by reacting a mixture of highly reactive polyols having a weight average molecular weight between about 4800 and 6500 g/mole and containing at least 70% primary hydroxyl groups and optionally fillers, polyfunctional isocyanates, amine activators, cross-linking agents, tin catalysts, blowing agents and stabilizers. The inventive stabilizers can be used universally in high resilience slabstock foam systems as well as in high resilience molded foam systems and in formulations based on pure TDI, TDI/MDI mixtures as well as on pure MDI in combination with appropriate polyols.

Abstract: In a method for the preparation of highly elastic, cold curing polyurethane foams, equilibrated organofunctional polysiloxanes of the average general formula ##STR1## wherein R.sup.1 is methyl or R.sup.2,R.sup.2 is chloropropyl,n has a value of 0 to 12,m has a value of 1 to 8 when R.sup.1 is methyl and a value of 0 to 6 when R.sup.1 is chloropropyl,are added in amounts of 0.01 to 2.0% by weight, based on the polyols, to the reaction batch.The stabilizing properties of the organofunctional polysiloxanes are superior to those of the known products. The foams, produced pursuant to the invention, have a coarser cell structure and a higher elasticity. The foams are more open-celled as measured by the impression force.