Patent ID: 7094826

Claim:
An aqueous ambient temperature crosslinkable coating composition comprising a crosslinkable water-dispersible hyperbranched macromolecule(s) with a PDi less than 60 and a dispersed polymer(s) with a particle size in the range of from 25 to 1000 nm and an acid value below 150 mgKOH/g where the ratio of the crosslinkable hyperbranched macromolecule(s) to the dispersed polymer(s) is in the range of from 90:10 to 25:75 on a solids weight basis, and wherein said composition when drying to form a coating has the following properties at 23±2° C.: i) an open time of at least 20 minutes at 23±2° C.; ii) a wet edge time of at least 10 minutes at 23±2° C.; iii) a tack-free time of ≦15 hours at 23±2° C.; iv) a dust free time of ≦5 hours at 23±2° C.; v) 0 to 25% of co-solvent by weight of the composition; and vi) an equilibrium viscosity of ≦5,000 Pa·s, when measured using any shear rate in the range of from 0.09±0.005 to 90±5 s −1 and an equilibrium viscosity of ≦3,000 Pa·s when measured using any shear rate in the range of from 0.9±0.05 to 90±5 s −1 , and an equilibrium viscosity of ≦1,500 Pa·s when measured using any shear rate in the range of from 9±0.5 to 90±5 s −1 , at any solids content when drying in the range of from 20 to 55% by weight of the composition and at 23±2° C. wherein said hyperbranched macromolecule(s) has a solution viscosity ≦80 Pa·s, as determined from an 80% by weight solids solution of the crosslinkable hyperbranched macromolecule(s) in at least one of the solvents selected from the group consisting of N-methylpyrrolidone, n-butylglycol and mixtures thereof, using a shear rate of 90±5 s −1 and at 50±2° C.; and wherein said hyperbranched macromolecule(s) has a solution viscosity ≦100 Pa·s, as determined from a 70% by weight solids solution of the crosslinkable hyperbranched macromolecule(s) in a solvent mixture consisting of: i) at least one of the solvents selected from the group consisting of N-methylpyrrolidone, n-butylglycol and mixtures thereof; ii) water and iii) N,N-dimethylethanolamine; where i), ii) and iii) are in weight ratios of 20/7/3 respectively, using a shear rate of 90±5 s −1 and at 23±2° C.; and wherein said dispersed polymer(s) is at least one member of the group consisting of vinyl polymer; polyurethane; polyester; polyether; polyamide; polyepoxide; and polymer hybrids thereof.