Process for Producing Compact or Cellular Polyurethane Elastomers Based on 3,3'-Dimethyl Biphenyl 4,4'-Diisocyanate-Containing Polyisocyanate Mixtures and Isocyanate Prepolymers Suitable therefor

摘要

Compact and preferably cellular polyurethane elastomers based on polyisocyanate mixtures containing 3,3'-dimethylbiphenyl 4,4'-diisocyanate are produced by reactinga) relatively high molecular weight polyhydroxyl compounds and, if desired,b) low molecular weight hydroxyl-containing chain extenders and/or crosslinkers withc) 3,3'-dimethylbiphenyl 4,4'-diisocyanate and at least one additional aromatic diisocyanate selected from the group consisting of tolylene diisocyanate, diphenylmethane diisocyanate, 1,2-diphenylethane diisocyanate and phenylene diisocyanate, and/or at least one aliphatic diisocyanate having from 4 to 12 carbon atoms and/or at least one cycloaliphatic diisocyanate having from 6 to 18 carbon atoms, where the formative components (a), (c) and, if used, (b) are advantageously reacted by the prepolymer method,in the presence or absence ofd) catalysts,e) blowing agents andf) additives.Isocyanate prepolymers suitable for this purpose are preferably ones based on diphenylmethane 4,4'-diisocyanate and 3,3'-dimethylbiphenyl 4,4'-diisocyanate.