OLIGOMERS, METHODS OF MAKING THEM, COATING COMPOSITIONS CONTAINING THEM, AND CURED COATINGS

An oligomer may be made by capping a uretdione compound of structure (I) wherein each R1 is independently selected from alkylene groups having 1 to 12 carbon atoms, arylene groups having 5 to 12 carbon atoms, and arylalkylene and alkylarylene groups having 6 to 15 carbon atoms, wherein alkylene groups, alkylene portions of arylakylene groups, and alkyl portions of alkylarylene groups may be linear, branched, or cyclic with a compound having an active hydrogen and having a carbamate group or cyclic carbonate group the reaction being carried out under conditions in which the isocyanate groups but not the uretdione group of compound (I) react to form a compound (III), the compound (III) then being reacted with a reactant having at least two active hydrogens selected from polyols, polyamines having at least two amine groups selected from primary and secondary amine groups, and aminoalcohols having at least one amine group that is a primary or secondary amine group to form a product that is an oligomer. Any cyclic carbonate groups may be converted to carbamate groups. Also disclosed is an oligomer comprising repeating monomer units of structures in which n is an integer from 1 to 4 and R1 is as previously defined. Also disclosed is a curable coating composition including at least one of the disclosed oligomers and at least one aminoplast resin crosslinker; a method of coating a substrate with the coating composition, a cured coating derived from the coating composition, and a coated substrate with the cured coating.