| abstract |
This invention is directed to an aqueous coating composition containing about 40-90% by weight, based on the weight of the coating composition, of an aqueous carrier and 10-60% by weight, based on the weight of the coating composition, of a binder of (a) about 50 to 98%, based on the weight of the binder, of a crosslinked graft copolymer comprising: (i) 2 to 98%, based on the weight of the graft copolymer, of a polymeric backbone of polymerized mono ethylenically unsaturated monomers and 0.5-10.0% by weight, based on the weight of the backbone, of polymerized difunctional ethylenically unsaturated crosslinking monomers and (ii) 98 to 2%, by weight of the graft copolymer, of macromonomers attached to said polymeric backbone at a single terminal point of each macromonomer, said macromonomers containing polymerized ethylenically unsaturated monomers and about 10 to 90%, based on the weight of the macromonomer, of polymerized ethylenically unsaturated monomers all containing carboxylic functionality such that the macromonomers are water dispersible when neutralized with an amine and the macromonomers have a weight average molecular weight of about 1,000-30,000; said graft copolymer being in the form of a stabilized crosslinked latex; and (b) 2 to 50%, based on the weight of the binder, of a crosslinking agent which, when the composition is cured, reacts and crosslink with the graft copolymer; such a composition provides an automotive finish with improved properties such as improved chip resistance in comparison to conventional finishes that are formed from a non-crosslinked latex. |