POROUS TITANIUM DIOXIDE COATINGS AND METHODS OF FORMING POROUS TITANIUM DIOXIDE COATINGS HAVING IMPROVED PHOTOCATALYTIC ACTIVITY

• US 20110045970A1
• Filed: 10/28/2010
• Published: 02/24/2011
• Est. Priority Date: 09/09/2008
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Sharma, Pramod K.
• Granted Patent: US 8,802,589 B2
• Time in Patent Office: Days
• US Class Current: 502/350
• CPC Class Codes: C03C 17/256 Coating containing TiO2
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2217/71 Photocatalytic coatings
• CPC Class Codes: C03C 2217/75 Hydrophilic and oleophilic coatings
• CPC Class Codes: C03C 2218/112 by spraying
• CPC Class Codes: C03C 2218/113 by sol-gel processes
• CPC Class Codes: C09D 1/00 Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
• CPC Class Codes: C09D 5/14 Paints containing biocides, e.g. fungicides, insecticides or pesticides C09D5/16 takes precedence
• CPC Class Codes: C09D 5/1618 inorganic
• CPC Class Codes: C09D 7/63 organic
• CPC Class Codes: C23C 18/1216 Metal oxides C23C18/1212 takes precedence
• CPC Class Codes: C23C 18/1254 Sol or sol-gel processing

Abstract

Methods for forming porous anatase titanium dioxide coatings are disclosed. Sol-gel compositions are prepared having at least one porosity agent, are applied to a substrate, and at least one porosity agent is removed. Porous anatase titanium dioxide coatings having at least one of improved antimicrobial properties, self-cleaning properties, hydrophilicity, and/or temperability are also disclosed. Substrates comprising such coatings are also disclosed.

Claims

1. A method of forming a porous anatase titanium dioxide coating on a substrate, comprising:

preparing a titanium dioxide sol-gel composition comprising at least one porosity agent;

coating the substrate with the sol-gel composition; and

removing the porosity agent.

2. The method of claim 1, wherein said porosity agent is polyethylene glycol.

3. The method of claim 2, wherein the polyethylene glycol is present in the sol-gel composition in an amount comprising at least about 5 wt % of the total weight of the sol-gel composition.

4. The method of claim 3, wherein the polyethylene glycol is present in the sol-gel composition in an amount comprising at least about 10 wt % of the total weight of the sol-gel composition.

5. The method of claim 4, wherein the polyethylene glycol is present in the sol-gel composition in an amount comprising at least about 20 wt % of the total weight of the sol-gel composition.

6. The method of claim 1, wherein the substrate comprises a glass substrate.

7. The method of claim 6, wherein the glass substrate is chosen from clear or low-iron glass.

8. The method of claim 1, wherein the porosity agent is removed by heating the coated substrate at a temperature greater than about 600°

C.

9. A method of improving at least one of antimicrobial properties, self-cleaning properties, hydrophilicity, and temperability of a titanium dioxide coating, comprising:

preparing a titanium dioxide sol-gel composition comprising at least one porosity agent;

coating a substrate with the sol-gel composition; and

heating the coated substrate to remove the porosity agent without forming rutile phase titanium dioxide.

10. The method of claim 9, wherein the porosity agent is polyethylene glycol.

11. The method of claim 10, wherein the polyethylene glycol is present in the sol-gel composition in an amount comprising at least about 5 wt % of the total weight of the sol-gel composition.

12. The method of claim 11, wherein the polyethylene glycol is present in the sol-gel composition in an amount comprising at least about 10 wt % of the total weight of the sol-gel composition.

13. The method of claim 12, wherein the polyethylene glycol is present in the sol-gel composition in an amount comprising at least about 20 wt % of the total weight of the sol-gel composition.

14. The method of claim 9, wherein said substrate is chosen from clear or low-iron glass.

15. A substrate comprising a porous anatase titanium dioxide coating, wherein the porous anatase titanium dioxide coating comprises a water contact angle less than about 12°

.

16. The substrate comprising a porous anatase titanium dioxide coating according to claim 15, wherein the porous anatase titanium dioxide coating comprises a water contact angle less than about 10°

.

17. The substrate comprising a porous anatase titanium dioxide coating according to claim 15, wherein the substrate is a glass substrate.

18. The substrate comprising a porous anatase titanium dioxide coating according to claim 17, wherein the porous anatase titanium dioxide coating comprises a visible light transmission greater than about 75%.

19. The substrate comprising a porous anatase titanium dioxide coating according to claim 17, wherein the porous anatase titanium dioxide coating comprises a reflection of incident light at the porous anatase titanium dioxide coating of less than about 26.5%.

20. (canceled)