Verfahren zur Herstellung von aromatischen Carbodiimiden

A process for the preparation of aromatic carbodiimides by means of the carbodiimidisation of aromatic monoisocyanates in the presence of distillable organic phosphorus compounds as catalysts at from 120 to 220@C up to a degree of carbodiimidisation of at most 80 %, and subsequent removal by distillation of the unreacted starting isocyanate, together with the catalyst, from the reaction mixture, and also, where appropriate, subsequent working up by distillation of the reaction mixture, and also the carbodiimides which can be obtained by this process.