Process for the preparation of polyisocyanates with biuret structure

摘要

A process for the continuous production of polyisocyanates (I) having a biuret structure by continuous reaction of an excess of organic diisocyanates having exclusively aliphatic and cycloaliphatic isocyanate groups with organic diamines having exclusively aliphatic and cycloaliphatic primary amine groups at greater than 170 degrees C comprises dose addition of acids during the reaction.