LIQUID 1,3-PHENYLENE DIISOCYANATE, 1,1'-BIPHENYL DIISOCYANATE AND 1,1'-OXY-BIS-(ISOCYANATO-BENZENE)

摘要

Allophanate-modified 1,3-phenylene diisocyanates or 1,1-biphenyldiisocyanates or 1,1'-oxy-bis-(isocyanato benzenes) which are storagestable liquid at 25°C are made by reacting the diisocyanate and a mono-alcohol to form an isocyanate containing urethane groups. The urethanegroups in the diisocyanate are then converted to allophanate groups.The resultant product which has an isocyanate group content of fromabout 10 to about 40% may be further reacted with isocyanate-reactivecompounds to produce an allophanate-modified diisocyanate prepolymercontaining urethane or urea groups having an isocyanate group contentof from about 5 to about 40.0%. The liquid, storage-stable, allophanate-modified diisocyanates produced by these processes are particularlyuseful in the production of elastomers and flexible foams.