Process for producing isocyanurates by cyclotrimerizing isocyanates using polymer-bound catalysts

摘要

This invention relates to a process for preparing a trimer by the steps of: (a) cyclotrimerizing a polyisocyanate in the presence a polymer- bound trimerization catalyst by contacting said polyisocyanate with said catalyst at a temperature of between about 20° and about 135. degree. C. in a reaction to form an isocyanurate-containing cyclotrimerized isocyanate wherein a portion of the isocyanate moieties comprising said polyisocyanate are converted to isocyanurate groups, and (b) separating said catalyst from said cyclotrimerized isocyanate in order to stop said reaction after a desired amount of isocyanate moieties in said polyisocyanate have been converted to isocyanurate moieties.