Depolluting coating composition

Abstract

The invention is a coating composition comprising photocatalytic titanium dioxide particles, an opacifying agent, a silicone compound, de-HNO 3 particles, styrene resin hollow microspheres, and a solvent. The combination of a silicone compound and styrene resin hollow microspheres in a depolluting coating composition results in improved opacity and durability compared to conventional coatings.

1 . A coating composition comprising: (a) photocatalytic titanium dioxide particles; (b) an opacifying agent; (c) a silicone compound; (d) de-HNO 3  particles; (e)styrene resin hollow microspheres; and (f) a solvent. 
     
     
         2 . The coating composition of  claim 1  wherein the photocatalytic titanium dioxide particles are anatase, rutile or mixtures thereof. 
     
     
         3 . The coating composition of  claim 1  wherein the photocatalytic titanium dioxide particles are predominantly anatase. 
     
     
         4 . The coating composition of  claim 3  wherein photocatalytic titanium dioxide particles have a mean particle size of between 2 and 100 nm. 
     
     
         5 . The coating composition of  claim 1  wherein the photocatalytic titanium dioxide particles are present in an amount ranging from 0.5 to 20%, by weight of the total composition. 
     
     
         6 . The coating composition of  claim 1  wherein the opacifying agent is pigmentary titanium dioxide. 
     
     
         7 . The coating composition of  claim 1  wherein the silicone compound is a polysiloxane. 
     
     
         8 . The coating composition of  claim 1  wherein the de-HNO 3  particles are selected from the group consisting of calcium carbonate, zinc carbonate, magnesium carbonate, and mixtures thereof. 
     
     
         9 . The coating composition of  claim 1  wherein the de-HNO 3  particles are calcium carbonate. 
     
     
         10 . The coating composition of  claim 1  wherein the styrene resin hollow microspheres are selected from the group consisting of polystyrene, poly-α-methylstyrene, and styrene-acrylic copolymer resins. 
     
     
         11 . The coating composition of  claim 1  wherein the styrene resin hollow microspheres are styrene-acrylic copolymer resins. 
     
     
         12 . The coating composition of  claim 1  wherein the solvent comprises water. 
     
     
         13 . The coating composition of  claim 1  further comprising an organic polymer. 
     
     
         14 . The coating composition of  claim 13  wherein the organic polymer is selected from the group consisting of acrylic polymers, polyvinyl acetates, and styrene-butadienes.