Patent ID: 6875834

Claim:
An aqueous coating composition comprising: (1) a first polymer comprising, as polymerized units: (a) 16 to 25 percent, based on the weight of the first polymer, of a monoethylenically unsaturated monomer containing an acidic functional group selected from one or more of carboxylic, sulfonic and phosphonic groups; and (b) zero up to 60 percent, based on the weight of the first polymer, of a (meth)acrylic monomer containing one or more pendant reactive functional groups selected from hydroxy, thiol and amino groups; and (c) zero up to 70 percent, based on the weight of the first polymer, of one or more vinyl aromatic monomers; and (d) 15 to 90 percent, based on the weight of the first polymer, of one or more (C 1 -C 20 ) alkyl (meth)acrylate ester monomers; and (e) zero up to 10 percent, based on the weight of the first polymer, of one or more other copolymerizable monomers; (1) a polyfunctional crosslinker agent comprising pendant functional groups selected from one or more of isocyanate, carbodiimide, aziridinyl and epoxy groups; (2) 0.1 to 15 percent, based on the weight of the aqueous coating composition, of coalescing agent; (3) zero up to 10 percent, based on the weight of the aqueous coating composition, of additives selected from one or more of waxes, surfactants, defoamers, leveling agents, alkali-soluble resins and plasticizers; and (4) 50 to 99 percent, based on the weight of the aqueous coating composition, of water; wherein: the first polymer has a number average molecular weight from grteater than 50,000 up to 2,000,000; the polyfunctional crosslinker agent is used in an amount sufficient to provide from 0.2 to 5 equivalents of pendant functional groups per equivalent of corresponding pendant reactive functional groups in the first polymer; the combined amount of (1) and (2) is from 10 to 90 percent, based on the weight of the aqueous coating composition; and the sum of (1), (2), (3), (4) and (5) percents add up to 100 percent.