De-polluting and self-cleaning epoxy siloxane coating
View Patent ↗De-polluting, self-cleaning coating compositions are disclosed which comprise photocatalytic titanium dioxide and a binder comprising an epoxy siloxane polymer. The compositions produce durable, self-cleaning coatings with photocatalytic activity against pollutants in the air, such as NO x compounds.
1. An organic solvent based composition for forming a self-cleaning, de-polluting single coating comprising:
(i) photocatalytic titanium dioxide;
(ii) a binder comprising an epoxy-functional silicon compound and an amino-functional silicon compound;
(iii) one or more pigments; and
(iv) an alkaline extender that is capable of neutralizing acidic species produced from degradation of NO x compounds;
wherein the total pigment volume concentration of the organic solvent based composition is about 5% to about 70% by volume of the dry coating, and wherein the organic solvent based composition is substantially free of water, and wherein the organic solvent based composition is capable of effective application to a substrate as a single coating.
2. The composition of claim 1 , wherein the amino-functional silicon compound is an amino silane.
3. The composition of claim 1 , wherein the epoxy-functional silicon compound is an epoxy siloxane polymer.
4. The composition of claim 1 , wherein the epoxy-functional silicon compound is an epoxy silane.
5. The composition of claim 1 , wherein the epoxy-functional silicon compound comprises one or more terminal epoxy groups.
6. The composition of claim 1 , further comprising a polysiloxane polymer or a silane compound.
7. The composition of claim 1 , wherein the pigment is titanium dioxide.
8. The composition of claim 1 , wherein the photocatalytic titanium dioxide is greater than about 95% in the anatase crystalline form.
9. The composition of claim 1 , wherein the total pigment volume concentration is about 10% to about 50%.
10. The composition of claim 1 , wherein the total pigment volume concentration is about 10% to about 40%.
11. The composition of claim 1 , wherein the total pigment volume concentration is about 15% to about 35%.
12. The composition of claim 1 , wherein the total pigment volume concentration is about 15% to about 30%.
13. The composition of claim 1 , wherein the total pigment volume concentration is about 20% to about 35%.
14. The composition of claim 1 , wherein the total pigment volume concentration is about 20% to about 30%.
15. The composition of claim 1 , wherein the composition comprises about 1% to about 10% photocatalytic titanium dioxide by volume.
16. The composition of claim 1 , wherein the composition comprises about 1% to about 5% photocatalytic titanium dioxide by volume.
17. The composition of claim 1 , wherein the composition comprises about 1% to about 3% photocatalytic titanium dioxide by volume.
18. The composition of claim 1 , wherein the composition comprises about 1% to about 5% photocatalytic titanium dioxide by volume and wherein the total pigment volume of the composition is about 10% to about 40%.
19. The composition of claim 1 , wherein the composition comprises about 1% to about 5% photocatalytic titanium dioxide by volume and wherein the total pigment volume of the composition is about 20% to about 35%.
20. The composition of claim 1 , wherein the alkaline extender is calcium carbonate.