Abstract: The invention relates to a process for producing viscoelastic polyurethane foams by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups in the presence of c) catalysts, d) blowing agents, wherein ai) diphenylmethane diisocyanate or aii) mixtures of diphenylmethane diisocyanate and polymethylenepolyphenylene polyisocyanates and/or aiii) prepolymers which comprise isocyanate groups and can be prepared by reacting aiv) polyether alcohols with diphenylmethane diisocyanate or mixtures of diphenylmethane diisocyanate and polymethylenepolyphenylene polyisocyanates are used as a) polyisocyanates and mixtures of at least one catalyst ci) and at least one catalyst cii) are used as catalysts.

Abstract: Highly resilient polyurethane foams are prepared by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms reactive with isocyanate groups, by a process in which a mixture containing, based in each case on the weight of the mixture, b1) from 5 to 75% by weight of at least one polymer polyol and b2) from 25 to 95% by weight of a mixture containing, based in each case on the weight of the mixture b2), b2i) from 70 to 98% by weight of at least one polyether alcohol having a molecular weight of from 3 500 to 6 500 g/mol, a functionality of less than or equal to 3 and an ethylene oxide content of from 8 to 20% by weight, based on the weight of the polyether alcohol, and b2ii) from 2 to 30% by weight of at least one polyether alcohol having a molecular weight of from greater than 4 000 to 7 000 g/mol, a functionality of from 4 to 8 and an ethylene oxide content of from 5 to 15% by weight, based on the weight of the polyether alcohol, is used as compounds b) having two hydrogen atom

Abstract: Highly resilient polyurethane foams are prepared by reacting