Patent ID: 8138262

Claim:
A waterborne, radiation-curable coating composition comprising: (a) a water dispersible polymer comprising a carboxylic acid functional vinyl polymer having an acid number of 15 to 50; (b) a hydrophobic multi-functional ethylenically unsaturated compound; and (c) a neutralizing agent comprising a monofunctional tertiary amine having a pK a of no more than 9.5 and present in an amount of at least 50 percent by weight, based on the total amine in the composition; wherein the monofunctional tertiary amine neutralizes acid groups of the carboxylic acid functional vinyl polymer; wherein the coating composition has a pH of 7 to 9″; wherein the composition has an initial viscosity of 100 to 300 centipoise at 77° F. and a final viscosity of 100 to 450 cps at 77° F. and wherein the composition is cured by exposure to ultraviolet rays or electron beam radiation.