Thermosetting aqueous varnish compositions

Abstract From the Canadian patent

Aqueous thermosetting varnish compositions that are particularly water resistant after curing are disclosed. These compositions contain by weight (A) about 20-40 percent of a solution copolymer polymerized from monomers consisting essentially of (a) about 50-75 percent vinyl ester of a C1-C3 carboxylic acid, (b) about 10-45 percent of C1-C8 alkyl acrylate or methacrylate ester and (c) about 5-15 percent of a mixture of (i) at least about 0.5 percent monoethylenically unsaturated C3-C5 carboxylic acid and (ii) at least about 2 percent C2-C4 hydroxyalkyl acrylate or methacrylate. The copolymer is polymerized at a temperature of at least 110°C. and at a non-volatile solids content of 60-80 …