The present disclosure is directed to an electrodepositable coating composition comprising (a) a hydroxyl-functional addition polymer comprising constitutional units, at least 70% of which comprise formula (I) wherein each R.sup.1 is independently one of hydrogen, an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group, an alkylcycloalkyl group, a substituted alkylcycloalkyl group, a cycloalkylalkyl group, a substituted cycloalkylalkyl group, an aryl group, a substituted aryl group, an alkylaryl group, a substituted alkylaryl group, a cycloalkylalkyl group, a substituted cycloalkylaryl group, an arylalkyl group, a substituted arylalkyl group, an arylcycloalkyl group, or a substituted arylcycloalkyl group, and the % based upon the total constitutional units of the hydroxyl-functional addition polymer; (b) an active hydrogen-containing, ionic salt group-containing film-forming polymer; (c) a curing agent; and (d) a curing catalyst.

A film-forming composition capable of undergoing dual cure, comprising: (1) a resin component comprising at least one polyepoxide; and (2) a radiation-curable diluent comprising a reaction product of a composition comprising: (a) a partially capped polyisocyanate; and (b) an ethylenically unsaturated monomer having active hydrogen functional groups capable of reacting with isocyanate groups. Also provided are processes for improving corrosion resistance of a metal substrate using the above composition.

Disclosed herein is a cathodic electrodeposition coating composition, which includes (A) a cationic amino-containing epoxy resin, (B) a blocked polyisocyanate having neutralized amine, which is obtained by a process including steps of (i) reacting a polyurethane prepolymer containing isocyanate groups with at least one blocking agent selected from the group consisting of oximes, pyrazoles and active methylene compounds, to provide a partially blocked polyisocyanate, (ii) reacting remaining isocyanate groups in the partially blocked polyisocyanate with an amine compound having active hydrogen, to provide an amine-containing blocked polyisocyanates, and (iii) neutralizing the amine-containing blocked polyisocyanates with an acid, and (C) a curing catalyst. Further disclosed herein are a process for preparing the cathodic electrodeposition coating composition, and a coating bath for the cathodic electrodeposition including the cathodic electrodeposition coating composition.

Disclosed herein is a method of dispersing a self-emulsifying crosslinker including at least two steps: i) preparing an aqueous acid dispersion (I) of a self-emulsifying crosslinker, and the microstructure of liquid phase of the aqueous acid dispersion (I) is water-in-oil; and ii) adding water into the aqueous acid dispersion (I) to obtain an aqueous acid dispersion (II), and the microstructure of liquid phase of the aqueous acid dispersion (II) is oil-in-water. Additionally disclosed here is a self-emulsifying crosslinker dispersion prepared by the method and the self-emulsifying crosslinker dispersion has a Z-average particle size in a range of from 50 to 200 nm.

An object of the present invention is to provide a preparation method for improving the edge part rust prevention property in the preparation of a cationic electrodeposition coating composition containing a bismuth compound as a curing catalyst. The present invention provides a method for preparing a cationic electrodeposition coating composition, including a step of preparing a resin emulsion (i) containing an aminated resin (A) and a blocked isocyanate curing agent (B), a step of preparing a pigment dispersion paste (ii) containing a bismuth-metal oxide mixture liquid (C) containing a bismuth compound (c1), a metal oxide (c2), a monohydroxycarboxylic acid (c3) having 3 to 5 carbon atoms in total and a solvent; a pigment dispersion resin (D); a polyvalent acid (E); and a pigment (F), and a step of mixing the resin emulsion (i) and the pigment dispersion paste (ii).

The invention provides an electrodepositable coating composition comprising a resinous phase dispersed in an aqueous medium, said resinous phase comprising: (1) an ungelled active hydrogen-containing, cationic salt group-containing resin; (2) an at least partially blocked polyisocyanate curing agent; and (3) a pigment component, wherein the pigment component comprises an inorganic, platelike pigment present in the resinous phase, wherein the electrodepositable coating composition contains less than 8 percent by weight of a grind vehicle, based on the total weight of solids in the electrodepositable coating composition. The invention also provides methods of improving the corrosion resistance of a metal substrate and coated substrates.