Waterborne Polyisocyanate Crosslinker (HDI-based, 75% in water-dispersible solvent)

Waterborne polyisocyanates are hydrophilically modified by grafting non-ionic polyether segments or ionic groups onto the HDI polyisocyanate backbone. These groups orient at the water interface and allow the isocyanate to disperse as fine droplets without rapid reaction. The kinetics of NCO-water reaction are sufficiently slow relative to NCO-hydroxyl crosslinking that a useful pot life of 4–8 hours is achieved before significant hydrolysis occurs.