The invention relates to a novel process for preparing low-monomer-content trimers based on 2,4- and/or 2,6-diisocyanatotoluene (TDI). A catalytic trimerization is carried out in a mixture of from 20 to 80% by weight of a diisocyanate component containing at least 80% by weight of 2,4- and/or 2,6-diisocyanatotoluene, from 20 to 80% by weight of solvent, and 0-20% by weight of an alcohol component, and also phenolic catalysts containing dialkylamino-methyl groups. In the course of ongoing trimerization, in one or more steps, additional monomeric 2,v4-diisocyanatotoluene is metered in.
本发明涉及一种基于2,4-和/或2,6-二异
氰酸甲苯(TDI)的低单体含量三聚体的新型制备工艺。在含有至少80%重量的2,4-和/或2,6-二异
氰酸甲苯的二
异氰酸酯组分20-80%重量,20-80%重量的溶剂和0-20%重量的醇组分的混合物中,进行催化三聚反应,并加入含有二烷基
氨基甲基基团的
酚类催化剂。在持续的三聚反应中,在一个或多个步骤中,不断加入额外的单体2,4-二异
氰酸甲苯。