application Covestro Desmodur N3400 HDI dimer ultra-low viscosity high-solid low-viscosity formula uses anti-yellowing curing agent Product Introduction Aliphatic polyisocyanate (HDI uretdione); Used as a curing agent component for ... 11/20154Covestro Desmodur N3400 HDI dimer ultra-low viscosity high-solid low-viscosity formula uses anti-yellowing curing agent