A process for producing possibly microcellular, elastic mouldings in the density range from 0.8 to 1.5 g/cm<3> with a compact surface from polyurethanes possibly containing urea groups by reacting a reaction mixture producing such polyurethanes produced by the reaction injection moulding process in closed moulds, in which the polyisocyanate component of the reaction mixture is a polyisocyanate mixture liquid above 5 DEG C based on 4,4'-diphenyl methane diisocyanate with an NCO content of 14.5 to 24 wt.% and a content of allophant groups (calculated as C2HN2O3, molecular weight = 101) of 7.7 to 14.5 wt.%.
