Patent ID: 7247671

Claim:
Aqueous crosslinkable coating composition suitable for anti-graffiti and heavy duty applications comprising: (A) an aqueous polymer emulsion comprising at least one vinyl fluoropolymer in which: (i) said at least one vinyl fluoropolymer comprises as a polymerised constituent monomer thereof a fluoromonomer(s) having the formula: wherein R 1 is CH 3 or H, R 2 is a perfluorinated C 1-5 alkyl group and n is 1, 2, 3 or 4, and wherein said fluoromonomer(s) forms from 5 to 60 weight % of the total monomers used to prepare said at least one vinyl fluoropolymer; (ii) said at least one vinyl fluoropolymer comprises as a polymerised constituent monomer thereof 2 to 58 weight % of a polymerised non-fluoro, non-acid hydroxyl functional monomer(s) in an amount to provide or contribute to a hydroxyl value, which said at least one vinyl fluoropolymer possesses, of at least 8 mg KOH/g of solid polymer; (iii) said at least one vinyl fluoropolymer comprises as a polymerised constituent monomer(s) thereof from 0.2 to 10 weight % of a non-fluoro, non-hydroxy carboxylic acid-functional monomer(s) in an amount to provide or contribute to an acid value, which said at least one vinyl fluoropolymer possesses, of within the range of from 2 to 80 mg KOH/g of solid polymer; (iv) wherein said at least one vinyl fluoropolymer comprises as a polymerised constituent monomer(s) 0 to 92 weight % of a non-fluoro, non-acid, non-hydroxyl monomer(s); and (v) said at least one vinyl fluoropolymer has a glass transition temperature Tg within the range of from −50 to 90° C.; and (B) at least one hydroxyl-reactive crosslinker material; wherein said at least one hydroxyl-reactive crosslinker material of component (B) is present in an amount such the ratio of hydroxyl groups from the polymer(s) of component (A) to the hydroxyl-reactive groups of the crosslinker material of component (B) is within the range of from 0.1 to 10, said coating composition providing coatings with anti-graffiti ratings of 30 to 35 against graffiti from seven differently colored markers.