The invention provides a multistage process for continuously preparing organic polyisocyanates, preferably diisocyanates, more preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic polyamines with carbonic acid derivatives and alcohols into monomeric polyurethanes of low molecular mass, and the dissociation of said polyurethanes. The invention further provides an associated preparation process in which at certain reaction stages the polyisocyanates prepared and unutilizable residues are removed and reusable by-products and intermediates are recycled to preliminary stages.
该发明提供了一种多级过程,用于连续制备有机聚
异氰酸酯,优选为二
异氰酸酯,更优选为脂肪族或环脂族二
异氰酸酯,通过将相应的有机
多胺与
碳酸衍
生物和醇反应成低分子量单体聚
氨酯,并解离所述聚
氨酯。该发明还提供了一个相关的制备过程,在该过程中,在某些反应阶段,制备的聚
异氰酸酯和无法利用的残留物被移除,并且可回收的副产物和中间体被循环利用到初步阶段。