US Patent 7544733 Stain resistant water-borne coating composition

Aqueous coating compositions are described where the binder includes an anionically stabilized polymeric dispersion. The monomers used to prepare the dispersion are acrylic acid and methacrylic acid as a carboxylic monomer and styrene, alpha methyl styrene or vinyl toluene as a hydrophobic high Tg aromatic monomer and an alkyl acrylate ester as a low Tg monomer. The relative weight proportions of the monomers are required to satisfy a formula. Blends of high and low Tg dispersions are also described. Paints formulated with the binders exhibit an excellent balance of stain resistance, tint strength and viscosity stability.