Process for making urethane-isocyanurates

A method for exposing a substrate to water in that is at least partly in the form of a liquid at a temperature of 70° C. to 140° C. and a pressure of 150 kPa to 5000 kPa, the method comprising:

• (a) applying a reaction mixture to a substrate, which reaction mixture has an isocyanate index of at least 10 and includes an aromatic polyisocyanate component, a polyol component having a polyol with a hydroxyl equivalent weight of at least 500, and a catalyst component having an isocyanate trimerization catalyst, and at least partially curing the reaction mixture to form a polyisocyanurate or polyurethane-isocyanurate polymer having a glass transition temperature of at least 80° C., and
• (b) exposing the substrate and the polyisocyanurate or polyurethane-isocyanurate polymer to water in that is at least partly in the form of a liquid at a temperature of 70° C. to 140° C., and a pressure of 150 kPa to 5000 kPa.