| abstract |
A two-part polyurethane adhesive system includes a resin component A and a curative B. The resin component A includes a monomeric polyisocyanate and a prepolymer. The curative B includes a polyether polyol having a molecular weight of from 3000 to 20,000 and another polyol having 4-8 hydroxyl groups and a molecular weight of from 200 to 1000. The system includes a tin (IV) catalyst, which is contained in the resin component, and a blocked aza-type catalyst, which is contained in the curative. The system has excellent shelf stability, gives an excellent open time at ambient temperatures, and cures rapidly when heated to 65°C or higher. |