| 摘要 |
This invention relates to polyisocyanates showing isocyanate groups blocked with 1,2,4-triazole having a blocked isocyanate group content of 7 to 14 percent by weight, constituting transformation products of A) A polyisocyanate constituent, composed by (i) polyisocyanates for lacquers based on (cyclo)aliphatic diisocyanates or by (ii) such polyisocyanates for lacquers mixtures with cycloaliphatic diisocyanates having a maximum molecular weight of 300, B) 50 to 80 equivalents percent, referred to constituent A) isocyanate groups of a monofunctional blocking agent for isocyanate groups, which is composed at least of up to 90 percent by weight 1,2,4-triazole, C) 10 to 30 equivalents percent, referred to constituent A) isocyanate groups of a polyester constituent with an OH index of 56 to 250 and, given the case, D) 0 to 20 equivalents percent, referred to constituent A) isocyanate groups of chosen hydrazine derivatives, and the use of blocked polyisocyanates as crosslinker in lacquers to bake a constituent polyurethane.
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