The invention concerns a method for preparing polyisocyanates by cyclodimerization of isocyanate functions borne by initial monomer isocyanates. The invention is characterised in that it comprises steps which consist in: a) providing a reaction medium comprising initial monomer isocyanates, optionally in the presence of a solvent; b) adding to said reaction mixture a (cyclo)dimerization catalyst comprising a compound of the family of super acids; c) heating the reaction medium to a temperature ranging between 0° C. and 300° C., advantageously between 20° C. and 200° C. until the desired rate of transformation is obtained; d) optionally inactivating or eliminating the reaction catalyst; and e) optionally eliminating the unreacted monomer.
本发明涉及一种通过环二聚化初始单体
异氰酸酯上的
异氰酸酯官能团制备聚
异氰酸酯的方法。该发明的特点在于,它包括以下步骤:a)提供包含初始单体
异氰酸酯的反应介质,可选地在溶剂的存在下;b)向所述反应混合物中加入一种(环)二聚化催化剂,该催化剂包括超酸家族的化合物;c)将反应介质加热至0℃至300℃之间的温度,优选在20℃至200℃之间,直到获得所需的转化率;d)可选地失活或消除反应催化剂;e)可选地消除未反应的单体。