Cellular Polyurethane elastomer which is produced by reacting:(a) an isocyanate component which includes methylenebis(phenyl isocyanate) (MDI) and/or tolylene diisocyante (TDI), in monomeric form or as liquefied prepolymer with(b) compounds which at least two isocyanate-reactive hydrogen atoms and(c) 4,4'-methylenebis(3-chloro-2,6-dialylaniline) or a mixture of 4,4'-methylenebis-(3-chloro-2,6-dialyaniline) with one or more aromatic, aliphatic or cycloaliphatic diamines as chain extending agent, if desired with further polyol, and(d) a blowing agent in the presence of the usual catalysts and, if desired, other additives.