Water based scratch-off ink for gaming forms

摘要

A scratch-off coating composition and method for application of the coating to lottery forms and the like employs a water based dispersion of acrylic resin, at approximately equal proportions of resin and water, by weight. The dispersion is adjusted to a pH greater than 7.0, and preferably a surfactant is added as a wetting, defoaming and/or dispersing agent. A pigment of metallic particles such as aluminum paste is added, together with a powdered filler such as calcium carbonate, at about 5 to 25% by weight of the coating composition. The composition can be applied in successive layers, including outer layers of relatively higher proportions of resin for improving wet rub resistance. For the outer surface layers, a number of ink formulations are disclosed.