Blocked isocyanates and their production and use.

摘要

Blocked polyisocyanates made with a plurality of blocking agents having substantially different deblocking agents have the advantage that they can be used without the parent polyisocyanate ever being released. More particularly, polyurethanes are made by reacting such blocked polyisocyanates with a suitable polyol first at a temperature such that one of the isocyanate groups becomes deblocked, and then at a higher temperature such that the remaining isocyanate groups are deblocked.