Epoxy-phosphate aqueous dispersions

A stable aqueous dispersion comprising an epoxy-phosphate ester polymer salt provided by reacting a diglycidyl ether of a bisphenol having an average molecular weight in the range of 2000 to 5000 and a 1,2-epoxy equivalency of from 1.5 to 2.0 with from 0.2 to 0.5 mol of orthophosphoric acid for each oxirane equivalent in the polyepoxide to thereby form a monoester reaction product containing from 30% to 80% of its initial oxirane content as residual epoxy functionality, and then reacting the monoester reaction product with at least 2 mols of a volatile amine per equivalent of oxirane functionality in said monoester to provide a water dispersible product lacking oxirane functionality, and then dispersing said water dispersible product in water together with from 5% to 50%, based on total resin solids, of aminoplast or phenoplast resin, said dispersion being effected with the aid of water miscible organic solvent comprising at least about 10% of an ether alcohol to provide organic solvent in a weight ratio with respect to water of 5:95 to 50:50.

A method of producing a water dispersible epoxy-phosphate ester polymer salt having improved stability in aqueous dispersion in admixture with aminoplast or phenoplast resin comprising reacting a resinous polyepoxide having at least about 1.4 oxirane groups per molecule with less than 0.9 mol of orthophosphoric acid for each oxirane equivalent in the polyepoxide to thereby form a monoester reaction product containing at least 10% of its initial oxirane functionality, and then reacting the monoester reaction product so-provided with at least 1 mol of a volatile amine per equivalent of oxirane functionality in said monoester to provide a water dispersible product lacking oxirane functionality.