Abstract: Coating of a resin blend on a metal substrate by electrodeposition wherein the resin blend comprises a poly(3,4-dihydro-3-substituted-1,3-benzoxazine) and a reactive polyamine. The resin blend is dispersed in an aqueous medium containing a protonating acid and is subjected to cathodic electrophoresis to deposit the blend on a metal substrate as an adherent film which is dried and cured by the application of heat. The resin blend cures at relatively low temperatures without evolution of volatile matter.

Abstract: An aqueous dispersion comprising a poly(3,4-dihydro-3-substituted-1,3 benzoxazine) and a protonated reactive polyamine, wherein the polyamine is at least difunctional, its reactive groups being primary or secondary amine and is protonated with an inorganic or organic acid and wherein the poly(dihydrobenzoxazine) is the reaction product of about 1 equivalent of a primary amine, about 1 equivalent of a phenol and about two equivalents of formaldehyde. The dispersions can be dried and cured to provide useful surface coatings and primers. The curing step occurs without evolution of volatile matter.