Patent ID: 8362132

Claim:
An aqueous coating composition having a pigment volume content (PVC) of from 78 to 85% comprising, based on the total volume solids of the dry coating unless otherwise stated: a) opacifying pigment particles comprising i) from 3 to 10% titanium dioxide, ii) from 0 to 20% of hollow polymeric particles; b) non-opacifying extender particles comprising at least one of i) calcium magnesium carbonate, ii) calcium carbonate, iii) nepheline syenite, and iv) kaolin, wherein i)+ii)+iii)+iv)=40 to 80%, and iv)=0 to 20%; c) polymer binder particles of calculated Fox Tg of from 5 to 25° C. having an acid value of from 15 to 65 mg KOH/g of polymer, comprising polymer binder particles derived from acrylic monomers and optionally further comprising styrene and/or its derivatives; d) a dispersant having a weight average molecular weight of at least 3500 Daltons, and wherein the dispersant demand of a mixture of the opacifying pigment particles, other than the hollow polymeric particles, of a), and the extender particles of b) is greater than 0.35 wt %, calculated on the weight of the titanium dioxide and extender particles, wherein the dispersant demand is estimated by the following method or its equivalent: i) gradually adding dispersant to an aqueous dispersion of the non-polymeric opacifying pigment particles and extender particles and monitoring the viscosity of the resulting mixture to determine the minimum viscosity; and ii) identifying the amount of dispersant added to reach the minimum viscosity as the dispersant demand; and e) a fugitive coalescing solvent; wherein the composition is free of non-fugitive coalescing solvent.