PROCESS FOR PREPARING COMPACT OR CELLULAR POLYURETHANE ELASTOMERS AND ISOCYANATE PREPOLYMERS SUITABLE FOR THIS PURPOSE

摘要

Polyurethane elastomer production is claimed in which the polyisocyanate component used together with high mol. wt. polyhydroxy components and optionally also low mol. wt. chain extenders and/or crosslinkers, catalysts, foaming agents etc comprises: (A) 1,4-phenylene diisocyanate; and (B) toluene diisocyanate, diphenylmethane diisocyanate, 3,3-dimethyl-diphenyl-diisocyanate, 1,2-diphenylethane-diisocyanate and/or a 4-12C aliphatic- and/or 6-18C cycloaliphatic-diisocyanate. Also claimed are prepolymers of NCO group content 3.3-10 wt.% obtained by reaction of the polyhydroxy component and optionally the chain extender and/or crosslinker with (B) to give a urethane polyaddition product of NCO content of 0.05-8 wt.% which is then reacted with (A). The aliphatic and cycloaliphatic diisocyanates in this instance are 1,6-hexamethylene diisocyanate and 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane.