Titanium dioxide coatings having roughened surfaces and methods of forming titanium dioxide coatings having roughened surfaces

• US 8,545,899 B2
• Filed: 11/03/2008
• Issued: 10/01/2013
• 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.
• Primary Examiner(s): Wax, Robert A
• Assistant Examiner(s): Park, H. Sarah
• Application Number:
  US12/263,968
• Publication Number:
  US 20100112024A1
• Time in Patent Office: 1,793 Days
• Field of Search: None
• US Class Current: 424/724
• 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;

adding colloidal silica particles to the titanium dioxide sol-gel composition to form a combined titanium dioxide and colloidal silica sol-gel composition, wherein the colloidal silica particles have an average particle size of about 70 nm to about 100 nm;

coating the substrate with the combined sol-gel composition; and

heating the coated substrate at a temperature ranging from about 550°

C. to about 650°

C. to form a surface roughened anatase titanium dioxide coating;

wherein the surface roughened titanium dioxide coating has a mean square roughness ranging from about 8 nm to about 12 nm; and

wherein the combined titanium dioxide and colloidal silica sol-gel composition comprises colloidal silica in an amount less than or equal to about 20 wt % relative to a total weight of the sol-gel composition.

2. The method of claim 1, wherein the combined titanium dioxide and colloidal silica sol-gel composition comprises at least 5 wt % of said colloidal silica particles relative to the total weight of the sol-gel composition.

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

4. The method of claim 3, wherein the glass substrate is chosen from clear glass and low-iron glass substrates.

8. The method of claim 1, wherein the titanium dioxide sol-gel composition comprises a titanium alkoxide or a titanium chloride.

10. The method of claim 1, wherein the combined titanium dioxide and colloidal silica sol-gel composition comprises colloidal silica in an amount less than or equal to about 15 wt % relative to the total weight of the sol-gel composition.

12. The method of claim 1, wherein the combined titanium dioxide and colloidal silica sol-gel composition comprises colloidal silica in an amount of about 5 wt % to about 15 wt % relative to the total weight of the sol-gel composition.

5. 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;

adding colloidal silica particles to the titanium dioxide sol-gel composition to form a combined titanium dioxide and colloidal silica sol-gel composition, wherein the colloidal silica particles have an average particle size of about 70 nm to about 100 nm;

coating a substrate with the combined sol-gel composition; and

heating the coated substrate at a temperature ranging from about 550°

C. to about 650°

C. to form a surface roughened anatase titanium dioxide coating;

wherein the surface roughened titanium dioxide coating has a mean square roughness ranging from about 8 nm to about 12 nm; and

wherein the combined titanium dioxide and colloidal silica sol-gel composition comprises colloidal silica in an amount less than or equal to about 20 wt % relative to a total weight of the sol-gel composition.

6. The method of claim 5, wherein the combined titanium dioxide and colloidal silica sol-gel composition comprises at least 5 wt % colloidal silica particles relative to the total weight of the sol-gel composition.

7. The method of claim 5, wherein the substrate is chosen from clear glass and low-iron glass.

9. The method of claim 5, wherein the titanium dioxide sol-gel composition comprises a titanium alkoxide or a titanium chloride.

11. The method of claim 5, wherein the combined titanium dioxide and colloidal silica sol-gel composition comprises colloidal silica in an amount less than or equal to about 15 wt % relative to the total weight of the sol-gel composition.

13. The method of claim 5, wherein the combined titanium dioxide and colloidal silica sol-gel composition comprises colloidal silica in an amount of about 5 wt % to about 15 wt % relative to the total weight of the sol-gel composition.