摘要 |
<p>Silicate esters which catalyse the formation of isocyanurates or isocyanaurate linkages in isocyanate condensation polymers have the formula <CHEM> wherein R1 is a C2-C4 alkylene radical and R2 is either a methyl or alkyl radical. The catalysts may be used to prepare polyurethanes, poly(isocyanurates) and poly(2-oxazolidones).</p> |