N-alkoxymethyl (meth)acrylamide functional polymers and their use in self-crosslinkable coating compositions

A method for applying a composite coating to a substrate which comprises applying to the substrate a colored film-forming composition to form a base coat and applying to said base coat a clear film-forming composition to form a transparent top coat over the base coat characterized in that the clear film-forming composition is self-crosslinkable and comprises as the main resinous component a non-gelled addition polymer which is the free radical initiated reaction product of the following polymerizable ethylenically unsaturated monomers:

• a) about 40 to 80% by weight of an N-alkoxymethyl(meth)acrylamide;
• b) about 20 to 60% total by weight of at least one polymerizable ethylenically unsaturated monomer selected from the group consisting of styrene, methyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, and mixtures thereof;
• c) up to 10% by weight, based on total weight of the polymerizable ethylenically unsaturated monomers used in preparing the polymer, of a hydroxyl functional ethylenically unsaturated monomer selected from the group consisting of hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, and hydroxybutyl (meth)acrylate, and
• d) up to 5% by weight, of an acid functional ethylenically unsaturated monomer, and
• where the percentage by weight is based on total weight of the polymerizable ethylenically unsaturated monomers used in preparing the polymer.