PROCESS FOR THE PRODUCTION OF ISOCYANATES PREFERABLY DIISOCYANATES AND POLYISOCYANATES WITH SOLVENT RECIRCULATION

摘要

The present invention relates to a process for the preparation of a compound of formula I by reacting an amine with phosgene in liquid or gaseous form to form the corresponding isocyanate and subsequently removing the solvent in two or more stages to obtain two or more solvent streams, Preferably diisocyanates and polyisocyanates, of diphenylmethane series (MDI) by recycling at least a portion of the stream.