| abstract |
Described herein is a process for producing polyurethane foams having a density of 30 g/dm3 to 70 g/dm3, in which (a) aromatic polyisocyanate is mixed with (b) polymeric compounds having isocyanate-reactive groups, (c) optionally chain extender and/or crosslinking agent, (d) catalyst, (e) blowing agent including water, (f) 0.1% to 5% by weight of lactam, and (g) optionally additives, at an isocyanate index of 50 to 95 to form a reaction mixture, and the reaction mixture is converted to the polyurethane foam, wherein the catalyst includes metal catalyst and amine catalyst, and the amine catalyst has tertiary nitrogen atoms and the content of tertiary nitrogen atoms in the amine catalyst is from 0.0001 to 0.003 mol/100 g of foam. Also described herein is a polyurethane foam and a method of using such a flexible polyurethane foam for the production of cushions, seat cushions, or mattresses. |