Curable compositions based on polyuretidiones, polythiols and photoactivable bases and generation of isocyanates from uretidiones

摘要

Curable compositions based on polyuretidiones, polythiols and photoactivable bases are disclosed. Also a process for generating isocyanate groups by exposing uretidiones to radiation in the range of 100-315 nm is disclosed. The process can be used in a dual curing system for curing compositions that comprise groups that under go photoinduced polymerizations and active hydrogen groups that react with the generated isocyanates.

主权项

1. A curable composition comprising
(a) a polyuretidione that contains from 5 to 45% by weight of uretidione groups; 10 to 55% by weight of urethane groups; and less than 2% by weight of isocyanate groups, the percentages by weight being based on total weight of uretidione, urethane and isocyanate groups; (b) a polythiol; and (c) a photoactivable nitrogen containing base.