POLYMERIC ALLOPHANATES OF DIPHENYLMETHANE DIISOCYANATE, PREPOLYMERS OF THESE POLYMERIC ALLOPHANATES, AND PROCESSES FOR THE PREPARATION OF THE POLYMERIC ALLOPHANATES AND THE PREPOLYMERS THEREOF

摘要

The present invention relates to a new high functionality MDI. Inparticular, this invention relates to polymeric allophanates based ondiphenylmethane diisocyanate having an NCO group content of 12 to30%, prepolymers thereof, and processes for the production of thesecompositions. The prepolymers are stable liquids having NCO groupcontents of about 10 to about 28%.