Photocatalytic compositions, and uses thereof for obtaining water paints

A building or construction which has received a coating including a photocatalytic composition which comprises:

• (a) at least one cement binder, in the range of 20% to 50% by weight;
• (b) at least one photocatalyst, wherein the at least one photocatalyst includes Titanium Dioxide particles, photocatalytically active in the visible spectrum, the Titanium Dioxide particles comprising 0.5% to 5% by weight;
• (c) at least one cellulose having a Brookfield viscosity RVT at 20° C. from 100 to 70,000 mPa·s, wherein the at least one cellulose is in the range of 0.8% to 2.2% by weight;
• (d) at least one fluidizing agent, wherein the at least one fluidizing agent is in the range of 0.1% to 1.2% by weight;
• (e) at least one first calcareous filler in the form of particles of which at least 95% by weight has a dimension not greater than 40 μm, wherein the at least one first calcareous filler is in the range of 15% to 35% by weight;
• (f) at least one second calcareous filler in the form of particles of which at least 95% by weight has a dimension not greater than 20 μm, wherein the at least one second calcareous filler is in the range of 15% to 35% by weight, wherein the at least one second calcareous filler has finer particle size than the at least one first calcareous filler;
• (g) at least one thermal insulator material comprising hollow ceramic spheres with sub-mm diameters, in the range of 0.1% to 4% by weight, and
• (h) glass bubble borosilicate microspheres, in the range of 0.1% to 4% by weight.

A method of manufacturing a photocatalytic composition, and adding water to the photocatalytic composition, the method including mixing together photocatalytic composition components comprising:

• (a) at least one cement binder, in the range of 20% to 50% by weight of the photocatalytic composition;
• (b) at least one photocatalyst, wherein the at least one photocatalyst includes Titanium Dioxide particles, photocatalytically active in the visible spectrum, the Titanium Dioxide particles comprising 0.5% to 5% by weight of the photocatalytic composition;
• (c) at least one cellulose having a Brookfield viscosity RVT at 20° C. from 100 to 70,000 mPa·s, wherein the at least one cellulose is in the range of 0.8% to 2.2% by weight of the photocatalytic composition;
• (d) at least one fluidizing agent, wherein the at least one fluidizing agent is in the range of 0.1% to 1.2% by weight of the photocatalytic composition;
• (e) at least one first calcareous filler in the form of particles of which at least 95% by weight has a dimension not greater than 40 μm, wherein the at least one first calcareous filler is in the range of 15% to 35% by weight of the photocatalytic composition;
• (f) at least one second calcareous filler in the form of particles of which at least 95% by weight has a dimension not greater than 20 μm, wherein the at least one second calcareous filler is in the range of 15% to 35% by weight of the photocatalytic composition, wherein the at least one second calcareous filler has finer particle size than the at least one first calcareous filler;
• (g) at least one thermal insulator material comprising hollow ceramic spheres with sub-mm diameters, in the range of 0.1% to 4% by weight of the photocatalytic composition, and
• (h) glass bubble borosilicate microspheres, in the range of 0.1% to 4% by weight of the photocatalytic composition;
• wherein water is added to the photocatalytic composition in a predetermined proportion, by mixing until a homogeneous and fluid product is obtained, wherein weight ratio between water and the at least one cement binder (a) is from 0.2 to 0.8.