| 摘要 |
A film-forming composition is provided comprising: (i) an amide functional polymer, copolymer or oligomer selected from (a) acrylic polymers, (b) polyesters, (c) polyurethanes, (d) polyethers or (e) mixtures thereof; and (ii) an aminoplast crosslinking agent containing methylol and/or methylol ether groups. The acrylic polymers have a plurality of groups of at least one of the structures: <IMAGE> (I) and <IMAGE> (II) wherein n is 0 or 1, R1 is hydrogen or methyl, R2 is a divalent linking group having about 1 to 30 carbon atoms when the group is of the first structure, or R2 is alkylene having about 2 to 13 carbon atoms when the group is of structure II, and R3 is hydrogen or lower alkyl having 1 to 4 carbon atoms. The (b), (c), and (d) polymers each have a plurality of terminal amide groups. The film-forming composition prior to curing has a theoretical hydroxyl value less than about 50 based on total resin solid weight of the film-forming composition, excluding any hydroxyl functionality associated with N-methylol groups. After curing, the film-forming composition exhibits a high level of acid etch resistance. The film forming composition can also be the clear film-forming composition with a base coat in a multi-component composite coating composition.
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