Patent ID: 8840718

Claim:
A coating composition comprising: (a) from 1% to 12% by weight, based on the total weight of the coating composition, of photocatalytic titanium dioxide particles having a mean particle size between 5 nm and 40 nm; (b) from 0.05% to 40% by weight of calcium carbonate particles, wherein the ratio of calcium carbonate particles to photocatalytic titanium dioxide particles is from 0.01 to 50; and (c) a polysiloxane polymer latex able to provide a silicone-based film wherein said polysiloxane comprises 0.05% to 20% by weight of the coating composition; (d) a solvent selected from water, an organic solvent or a mixed solvent consisting of water and an organic solvent; and (e) from 0.1% to 20% based on the total weight of the coating composition, of hollow styrene acrylic copolymer resin microspheres having an outside diameter of from 0.1 μm to 10 μm, wherein (i) the opacity of a dry film coating formed from said coating composition is greater than the opacity of a dry film coating formed from the same coating composition which is absent said hollow styrene resin microspheres, and (ii) percent weight loss of said dry film coating over a defined time period is less than percent weight loss of the dry film coating absent the styrene microspheres over the same defined time period.