Polyurethanes with low volume contraction

Using components of free polyisocyanate solvent A) they consist of from 5 to 95% by weight of polyisocyanate molecules constructed from at least two molecules of araliphatic diisocyanate and 95 to 5% by weight of araliphatic monomeric diisocyanates, and present a content of isocyanate groups of 18 to 43 5% by weight, for the manufacture of bodies of compact polyurethane or foamed lightfastness.