Pigmented low temperature cure emulsions

A process for preparing a stable, aqueous latex sealer comprising water, one or more binder latexes, and a glycoluril crosslinking agent adapted to cure with said binder latexes, which comprises

• providing a latex sealer composition comprising by weight between 5% and 60% of a glycoluril crosslinking agent and between 40% and 95% of an emulsion polymer latex prepared in an aqueous medium and selected from the group consisting of acrylic, styrene acrylic, vinyl acetate, vinyl chloride and vinylidene chloride binder or mixtures thereof, said emulsion polymer having a reactive functionality selected from the group consisting of hydroxyl, carboxyl, amido or methylolamido adapted to react with said glycoluril crosslinking agent, said emulsion polymer free of amine groups;
• and
• treating said latex sealer composition with a protonated cation exchange agent to provide a latex coating having a pH of less than about 2.5, whereby said coating does not gel or destabilize at room temperature, but is heat curable at temperatures from about 60.degree. F. to 350.degree. F. without addition of acid cure catalyst.

A process for preparing a stable, clear aqueous acrylic latex sealer comprising water, one or more binder latexes, and a glycoluril crosslinking agent adapted to cure with said binder latexes, which comprises

• providing a latex sealer composition comprising by weight between 5% and 60% of a glycoluril crosslinking agent and between 40% and 95% of an emulsion polymer comprising polymerized ethylenically unsaturated monomers on a weight basis of between 0% and 10% carboxylic monomer, 2% and 20% alkylhydroxy acrylate or methacrylate monomer, and the balance being other ethylenically unsaturated monomer comprising monomers selected from vinyl monomers, styrene monomers or acrylate monomers whereby said emulsion polymer contains reactive groups for crosslinking reaction with said crosslinking agent, and said emulsion polymer being free of amine groups;
• and
• treating said latex sealer with a cation exchange agent to provide a latex coating composition having a pH less than about 2.5, which does not gel or destabilize at room temperature, but is heat curable at temperatures from about 60.degree. F. to 350.degree. F. without addition of acid cure catalyst.

A coating composition substantially free of cations comprising by weight between 20% and 95% emulsion polymer and between 5% and 80% glycoluril, said emulsion polymer containing reactive hyroxy, carboxyl, or acrylamide groups adapted to be coreactive with glycoluril, where said emulsion polymer is free of amine groups, said composition produced by treating the coating composition with ion exchange resin to substantially remove the cations from the emulsion polymer and the glycoluril to reduce the pH of the coating composition to less than about 2.5.