The Effect of MolecularWeight of Epoxy Resin on the Deposition Behaviour of Water-borne Epoxy-amine

Water-borne epoxy resins were prepared by reacting epoxy resins with different molecular weights (360, 900, 1700, 3200) with diethanolamine. The resins were then neutralized with 10% by wt acetic acid and emulsified in water. The resins were applied onto steel panels by a cathodic electrodeposition procedure. The deposition behaviour of the resins were studied using the effect of voltage-time (at constant current) and current density-time (at constant voltage) variations on the determined coulombic efficiency and the throwing power.