TITANIUM DIOXIDE COATINGS HAVING ROUGHENED SURFACES AND METHODS OF FORMING TITANIUM DIOXIDE COATINGS HAVING ROUGHENED SURFACES

• US 20100112024A1
• Filed: 11/03/2008
• Published: 05/06/2010
• Est. Priority Date: 11/03/2008
• 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 8,545,899 B2
• Time in Patent Office: Days
• US Class Current: 424/409
• CPC Class Codes: A01N 25/34 Shaped forms, e.g. sheets, not provided for in any other sub-group of this main group
• CPC Class Codes: A01N 59/16 Heavy metals; Compounds thereof
• CPC Class Codes: C03C 17/007 containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• CPC Class Codes: C03C 2217/45 Inorganic continuous phases
• CPC Class Codes: C03C 2217/48 having a specific function
• CPC Class Codes: C03C 2217/77 Coatings having a rough surface
• CPC Class Codes: C03C 2218/113 by sol-gel processes
• CPC Class Codes: Y10T 428/24413 Metal or metal compound

Abstract

Methods for forming surface roughened titanium dioxide coatings are disclosed. Sol-gel compositions may be prepared having colloidal metal oxide particles and/or colloidal silica particles, formed on a substrate, and subsequently the coated substrate may be heated at a temperature sufficient to form a surface roughened anatase titanium dioxide coating. Surface roughened titanium dioxide coatings having at least one of improved antimicrobial properties, self-cleaning properties, hydrophilicity, and/or activation time are also disclosed. Substrates comprising such coatings are also disclosed.

Claims

1. A method of forming an anatase titanium dioxide coating having a roughened surface on a substrate, comprising:

preparing a titanium dioxide sol-gel composition comprising colloidal metal oxide particles or colloidal silica particles;

coating the substrate with the sol-gel composition; and

heating the coated substrate to form a surface roughened anatase titanium dioxide coating.

2. The method of claim 1, wherein the colloidal metal oxide particles or colloidal silica particles have an average particle size less than or equal to about 200 nm.

3. The method of claim 2, wherein the colloidal metal oxide particles or colloidal silica particles have an average particle size less than or equal to about 100 nm.

4. The method of claim 1, wherein the surface roughened titanium dioxide coating has a mean square roughness ranging from about 2 nm to about 20 nm.

5. The method of claim 4, wherein the surface roughened titanium dioxide coating has a mean square roughness ranging from about 8 nm to about 12 nm.

6. The method of claim 1, wherein the sol-gel composition comprises at least 5 wt % of said colloidal metal oxide particles or colloidal silica particles relative to the total weight of the sol-gel composition.

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

8. The method of claim 7, wherein the glass substrate is chosen from clear glass and low-iron glass substrates.

9. The method of claim 1, wherein the coated substrate is heated at a temperature of about 600°

C. or greater.

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

preparing a titanium dioxide sol-gel composition comprising colloidal metal oxide particles or colloidal silica particles;

coating a substrate with the sol-gel composition; and

heating the coated substrate to form a surface roughened anatase titanium dioxide coating.

11. The method of claim 10, wherein the colloidal metal oxide particles or colloidal silica particles have an average particle size less than or equal to about 200 nm.

12. The method of claim 11, wherein the colloidal metal oxide particles or colloidal silica particles have an average particle size less than or equal to about 100 nm.

13. The method of claim 10, wherein the surface roughened titanium dioxide coating has a mean square roughness ranging from about 2 nm to about 20 nm.

14. The method of claim 13, wherein said surface roughened titanium dioxide coating has a mean square roughness ranging from about 8 nm to about 12 nm.

15. The method of claim 10, wherein the sol-gel composition comprises at least 5 wt % colloidal silica particles relative to the total weight of the sol-gel composition.

16. The method of claim 10, wherein the substrate is chosen from clear glass and low-iron glass.

17. The method of claim 10, wherein the coated substrate is heated at a temperature of about 600°

C. or greater.

18. An antimicrobial and/or self-cleaning laminate, comprising:

a substrate;

a surface roughened anatase titanium dioxide coating comprising colloidal metal oxide particles or colloidal silica particles on a surface of the substrate.

19. The antimicrobial and/or self-cleaning laminate of claim 18, wherein the surface roughened anatase titanium dioxide coating comprises at least about 5 wt % of colloidal silica particles or metal oxide particles.

20. The antimicrobial and/or self-cleaning laminate of claim 19, wherein the surface roughened anatase titanium dioxide coating comprises at least about 10 wt % of colloidal silica particles or metal oxide particles.

21. A titanium dioxide coated substrate, wherein said titanium dioxide coating is made by:

preparing a titanium dioxide sol-gel composition comprising colloidal metal oxide particles or colloidal silica particles;

coating a substrate with the sol-gel composition; and

heating the coated substrate to form a surface roughened anatase titanium dioxide coating.