POLYISOCYANATES CONTAINING ALLOPHANATE AND ISOCYANURATE GROUPS, A PROCESS FOR THEIR PRODUCTION FROM A MIXTURE OF DIISOCYANATES AND THEIRUSE IN TWO-COMPONENT COATING COMPOSITIONS

摘要

The present invention is directed to a polyisocyanate mixture which i) has an NCO content of 10 to 47% by weight, ii) is prepared from a mixture of 1,6-hexamethylene diisocyanate and a cyclic organic diisocyanate having (cyclo)aliphatically-bound isocyanate groups in a molar ratio of 10:90 to 90:10 and iii) contains isocyanurate and allophanate groups in a molar ratio of monoisocyanurates to monoallophanates of 10:1 to 1:5, wherein the allophanate groups are formed from urethane groups which are based on the reaction product of an organic diisocyanate having (cyclo)aliphatically bound isocyanate groups and a monoalcohol containing at least 1 carbon atom and having a molecular weight of up to 2500. The present invention is also directed to a process for the production of these polyisocyanate mixtures and to their use, optionally in blocked form, as an isocyanate component in two-component coating compositions.