Process for preparing polyurethane elastomers utilising diols of the dianhydro-hexitol-type in connection with polyoxyalkylene-polydialkyl siloxane copolymers

摘要

1. Process for the preparation of compact polyurethane elastomers by the reaction of a) 1,5-diisocyanatonaphthalene or mixtures of aromatic diisocyanates predominantly containing 1,5-diisocyanatonaphthalene, b) relatively high molecular weight compounds in the molecular weight range of from 400 to 10 000 containing at least two isocyanate reactive hydrogen atoms or isocyanate prepolymers of a) and b) and optionally a proportion of c), c) chain lengthening agents or mixtures of chain lengthening agents having molecular weights of from 62 to 399, d) silicones and optionally e) catalysts and other known additives, characterized in that diols of the 1,4-3,6-dianhydrohexitol series are used as chain lengthening agents c), optionally in admixture with other low molecular weight chain lengthening agents, in combination with one or more polyoxyalkylene-polydialkylsiloxane copolymers in quantities of from 0.5 to 5 % by weight, based on the polyurethane.