Polyurethane crosslinkers, and the process for preparing and using the same

摘要

A polyurethane crosslinker is provided by reacting a partially-blocked diisocyanate and a hydroxyl-terminated, carboxyl group-containing polyurethane precursor. The precursor is a reaction product of a diol containing a carboxyl group and another diol of high molecular weight, and a diisocyanate. The instant crosslinkers are particularly useful in water-based coating compositions for metal containers.