New polymeric allophanates of diphenylmethane diisocyanate, perpolymers 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. In particular, this invention relates to polymeric allophanates based on diphenylmethane diisocyanate having an NCO group content of 12 to 30%, prepolymers thereof, and processes for the production of these compositions. The prepolymers are stable liquids having NCO group contents of about 10 to about 28%.