Electrodepositable coating compositions comprising onium salt group-containing polymers prepared by atom transfer radical polymerization

摘要

Disclosed are thermosetting compositions which are comprised of a resinous phase dispersed in an aqueous medium, the resinous phase comprising (a) an ungelled active hydrogen group-containing polymer which contains onium salt groups, the polymer having been prepared by atom transfer radical polymerization in the presence of an initiator having at least one radically transferable group, and (b) a curing agent having at least two functional groups which are reactive with the active hydrogen groups of (a). The active hydrogen group-containing polymers of the thermosetting compositions, which are prepared by atom transfer radical polymerization, have narrow molecular weight distributions and well-defined, specifically tailored polymer architecture which can provide enhanced crosslink density and dispersibility of the thermosetting compositions. Also disclosed is a method of electrocoating a conductive substrate using the thermosetting compositions of the invention, and a substrate coated by this method.