Abstract: An improved aqueous cathodic electrocoating composition having a binder of an epoxy-amine adduct which is of an epoxy resin that has been reacted with an amine, and a blocked polyisocyanate crosslinking agent; wherein the improvement is the use of a water soluble electrically conductive polymeric additive of a polyepoxy hydroxy ether resin reacted with a ketimine and optionally up to 60% of the epoxy end groups of the resin reacted with another amine and the resin has an epoxy equivalent weight of about 500-900, a weight average molecular weight of about 1,000-5,000 and an electrical conductivity of about 4,000-8,000 microsiemens to provide an electrocoating composition having improved throw power.

Abstract: An electrocoating composition containing an epoxy amine adduct which is the reaction product of a polyepoxide resin and an amine, an acrylic amine resin and a blocked polyisocyanate crosslinking agent;wherein the composition is prepared by blending a first emulsion of the epoxy amine adduct and the blocked polyisocyanate crosslinking agent with a second emulsion of the acrylic amine resin and a blocked polyisocyanate crosslinking agent; where the first and second emulsions are each individually formed by blending the adduct or resin with the blocked crosslinking agent and then adding an organic acid to form a salt which forms a stable aqueous emulsion.

Abstract: An improved electrodepositable cationic resin is disclosed. Prior art electrodepositable cationic resins are formed from polyepoxides which are chain extended with polyether or polyester polyols to internally flexibilize the resin. Our polyepoxide resin is chain extended with amide diol which gives a resin which is hydrolytically stable and does not tend to absorb moisture.