Process for preparing stable solutions of trimerized isocyanates in monomeric polyisocyanates

摘要

Trimerized isocyanates having improved solubility in polyisocyanates are prepared by reacting a polyisocyanate with a low equivalent weight polyol to form a first prepolymer, forming a cotrimer from said first prepolymer by reaction of same with diphenylmethane diisocyanate or polymeric derivatives thereof, and forming a second isocyanate terminated prepolymer by reacting said cotrimer with a second low equivalent weight polyol. The resulting cotrimer can be diluted in a polyisocyanate and used to prepare polymers, particularly polyurethane foams, having excellent properties.