| 摘要 |
Use of 0.02-2 wt.% of a quaternized benzylammonium carboxylate trimerization catalyst for preparation of low viscosity and less colored polyisocyanates containing isocyanurate groups by partial trimerization of (cyclo)aliphatic diisocyanates and separation of the excess diisocyanate. Low viscosity and less colored polyisocyanates containing isocyanurate groups are prepared by partial trimerization of aliphatic and/or cycloaliphatic diisocyanates and separation of the excess diisocyanate, in the presence of 0.02-2 wt.%, based on the total wt. of diisocyanate, of at least one trimerization catalyst of formula (I). R<1> = (II); A-E = H, Cl, 1-4C alkyl, alkoxy or alkoxycarbonyl, OH, (R<5>)3SiO-, (R<5>)2N-, -COOH, (R<5>)2N-CH2- or phenyl, or any two adjacent groups A to E can form a common 5- or 6-membered (un)saturated ring which can also contain nitrogen, sulfur or oxygen heteroatoms; F, G = H, Me or F; R<2>, R<3> = 1-18C alkyl or R<1>; R<4> = H, Me, 2-18C alkyl, 3-8C cycloalkyl or 2-12C alkoxy; R<5> = 1-18C alkyl; Y<-> = R<6>COO<->; and R<6> = H or optionally branched 1-12C aliphatic or araliphatic. Independent claims are also included for: (1) the diisocyanate trimerization catalyst of formula (I) and (2) its preparation. |
