Verfahren zur Herstellung von Polyurethanelastomeren

摘要

A polyurethane elastomer is prepared by reacting in the melt or in an inert organic solvent a linear dihydroxy compound of M.W. 500-5000 and melting point below 60 DEG C. with a molar excess of an organic diisocyanate in an OH/NCO ratio of 1:1.5 to 1:3, mixing the -NCO terminated prepolymer obtained with 80-130% of the stoichiometric amount calculated on the -NCO groups of an organic chain extender of formula R1-NH-(CH2)x-Y-(CH2)x-NHR1/h where R1 is hydrogen or a lower alkyl group and Y is the radical obtained either by removing the hydrogen atoms from the nitrogen atoms of piperazine or a lower alkyl piperazine or Y is a functional radical of the formula in which R1 is a lower alkyl group and #c is an integer from 1-4, the chain extending reaction being effected in an organic polar solvent at 0-100 DEG C. and recovering the polyurethane having 20-1000 milliequivalents of tertiary nitrogen per kg. of polyurethane elastomer from the solution.