Patent ID: 8748528

Claim:
A liquid coating composition useful for providing a water-vapor permeable, air barrier membrane by coating on a construction surface, the liquid coating composition being an aqueous emulsion, comprising: a hydrophobic acrylic polymer, wherein the hydrophobic acrylic polymer comprises about 50% to 97% by weight based on total solids in the liquid composition, the hydrophobic acrylic polymer comprising a homopolymer or a copolymer of an acrylic ester having a repeating group represented by the structure —(—CH 2 —C(R 1 )HCOOR—)— wherein R is a C2-C8 alkyl group and R 1 is H or CH 3 ; a water soluble polymer, wherein the water-soluble polymer comprises about 1% to 20% by weight based on total solids in the liquid composition, and wherein the water-soluble polymer comprises polyvinyl alcohol, polyethylene oxide, water soluble cellulosic polymers, hydrolyzed maleic anhydride polymers and copolymers, polyvinylpyrrolidone, sulfonated polystyrene, polysulfoethyl acrylate, poly(2-hydroxyethylacrylate), polyacrylamide, poly(acrylic acid) and alkali metal salts thereof, natural or synthetically modified polysaccharides, proteins, alginates, xanthan gums, or guar gums, or combinations of two or more of such water soluble polymers; an inorganic filler, wherein the inorganic filler comprises about 2-40% by weight based on total solids in the liquid composition; a freezing-point lowering component comprising a water-soluble metal salt, wherein the water-soluble metal salt comprises about 0.5-15% by weight of the total weight of the liquid composition, said water-soluble metal salt comprising calcium nitrite, sodium nitrite, or a mixture thereof; and an evaporation enhancing agent in an amount of about 0.5-15% by weight of the total weight of the liquid composition, the evaporation enhancing agent comprising at least one solvent selected from methanol, ethanol, oxybis-propanol, vinyl acetate, butyl acetate, ethyl acetate, methyl isobutyl ketone, methyl ethyl ketone, or a combination of two or more of these solvents; and wherein the liquid composition comprises water in an amount of about 30-50% by weight of the total weight of the liquid composition.