Water-dispersed epoxy/acrylic coatings for plastic substrates

A plastic substrate which has been coated with a paint coating composition containing a thermosetting polymeric binder comprising on a polymer weight basis:

• between 20% and 99% acrylic copolymer of copolymerized ethlenically unsaturated monomers comprising by weight 50% and 90% acrylic monomer, between 1% and 25% carboxyl functional monomer, between 1% and 30% of tertiary amine functional monomer, with the balance being other ethylenically unsaturated monomer, where said acrylic copolymer is self-neutralizing and dispersible into water due to the tertiary amino functional groups of the copolymerized tertiary amine functional monomer;
• between 1% and 80% epoxy resin comprising the coreaction product of three to five molecules of epichlorohydrin reacted with one molecule of sorbitol, where said epoxy resin is adapted to crosslink with said acrylic copolymer upon curing, said epoxy resin coreacted with sufficient alkanolamine compound to render the epoxy resin water dispersible;
• where said acrylic copolymer and said epoxy resin are dispersed into water;
• and
• said coating composition is applied to said plastic substrate and said polymeric binder is thermoset at ambient temperatures.