DE2940856

A process for the manufacture of non-cellular and cellular polyurethane elastomers by (a) preparing a hydroxyl group-containing prepolymer by reacting a higher molecular weight polyhydroxyl compound and optionally a chain extender with an organic diisocyanate at a weight ratio of OH groups to NCO groups of 1.2:1 to 2:1, (b) dividing the prepolymer into two components A and B in a weight ratio of about 80:20 to 20:80, (c) reacting component A with 1,5-naphthylene diisocyanate (NDI) in a weight ratio of OH:NCO groups of about 1:2.5 to 1:12 to produce a terminal NCO group-containing NDI-polyurethane adduct, (d) mixing component B with chain extenders and/or cross-linking agents and/or water, and optionally auxiliaries and additives, and (e) reacting the NDI-polyurethane adduct (from step c) with the mixture from step d.