abstract |
A multi-component composite coating composition comprising a base coat deposited from a pigmented film-forming composition and a transparent top coat applied over the base coat in which the base coat is a thermosetting composition comprising a co-reactable solid, particulate mixture of (i) an epoxy functional polymer containing at least one of the polymer chain structures -[(M)p-(G)q]x- or -[(G)q-(M)p]x- wherein M is an oxirane-free residue of at least one ethylenically unsaturated monomer, G is a glycidyl-functional ethylenically unsaturated monomer, p and q each independently has a value of 0 to typically less than 100, and x has a value of at least 1 to typically less than 100, the total value of p, q and x selected such that said epoxy functional polymer has a number average molecular weight of at least 250, and (ii) a co-reactant having functional groups reactive with the epoxy groups of (i). The epoxy functional polymer is prepared by atom transfer radical polymerization and has a polydispersity index of less than 2.5. |