摘要 |
<p>Mixtures comprisea) polyisocyanates (polyisocyanates A), comprising structural units selected from the isocyanurate and biuret group, derived from aliphatic or cycloaliphatic diisocyanates (diisocyanates C),b) non-A polyisocyanates (polyisocyanates B), comprising structural units selected from the allophanate and urethane group, derived fromb1) aliphatic or cycloaliphatic diisocyanates (diisocyanates C) andb2) polyhydric aliphatic or cycloaliphatic alcohols (alcohols A),the molar ratio of the polyisocyanates A to the polyisocyanates B being from 200:1 to 5:1.</p> |