Methods of making oligomers, coating compositions containing them, and coated articles

摘要

An oligomer is made by capping a uretdione compound of structure with a compound (II) having an active hydrogen and a carbamate or cyclic carbonate group under conditions in which the isocyanate groups but not the uretdione group react. The product (III) is either reacted with a reactant having at least two active hydrogens under reaction conditions that cleave the uretdione ring, after which any cyclic carbonate groups may be converted to carbamate groups, or a product (III) having cyclic carbonate groups is reacted with ammonia or primary amine to provide uretdione with a hydroxy carbamate group that is then self-condensed under uretdione ring-opening conditions. A curable coating composition comprises the oligomer; a coated article is prepared by applying a layer of the curable coating composition and curing the applied layer.