VERFAHREN ZUR HERSTELLUNG VON ISOCYANATGRUPPEN AUFWEISENDEN PREPOLYMEREN, DIE NACH DIESEM VERFAHEN ERHAELTLICHEN PREPOLYMEREN UND IHRE VERWENDUNG ALS BINDEMITTEL IN EINKOMPONENTENLACKEN.

摘要

New free isocyanate gp.-contg. prepolymers contg. 1-16 wt.% isocyanate are prepd. by reacting: (a) a polyisocyanate component with (b) a polyhydroxyl component consisting of (i) at least one polyester-polyol having average OH-functionality 1.8-5 and average OH-no. 15-300, or of (ii) mixts. of polyester-polyols (i) with up to 10 wt.%, w.r.t. the wt. of the mixt., of opt. ester gp.-contg. (cyclo)alkane-polyols having OH-no. over 300; while maintaining an NCO/OH-equiv. ratio above 2:1. The novelty consists in using, as component (a), (1) triisocyanato -isocyanurates having formula (I), where X1,X2,X3 are each opt. different difunctional, aliphatic or cycloaliphatic hydrocarbyl having mol.wt. 84-206, (2) mixts. of (I) with their higher homologues (II) contg. over 1 isocyanurate ring, or (3) mixts. of (I) and (II) with up to 60 NCO equiv.%, w.r.t. the total amt. of (a), of isocyanurate gp.-free polyisocyanates. The prepolymers are claimed per se.