Low-maintenance coatings

• US RE43,817 E1
• Filed: 10/12/2011
• Issued: 11/20/2012
• Est. Priority Date: 07/12/2004
• Status: Active Grant

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Inventors: Krisko, Annette J., Myli, Kari B., Pfaff, Gary L., Brownlee, James E.
• Primary Examiner(s): Sample, David R
• Application Number:
  US13/271,794
• Time in Patent Office: 405 Days
• Field of Search: None
• US Class Current: 428/432
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 17/3423 at least one of the coatings comprising a suboxide
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2217/213 SiO2
• CPC Class Codes: C03C 2217/71 Photocatalytic coatings
• CPC Class Codes: C03C 2218/155 by reactive sputtering
• CPC Class Codes: C03C 2218/156 by magnetron sputtering

Abstract

The invention provides a substrate bearing a low-maintenance coating. The coating includes two films: a first film comprising silica (e.g., silicon dioxide) and a second film comprising titania (e.g., titanium dioxide). Preferably, both films are provided within particular thickness ranges. The invention also provides methods of depositing such coatings.

Claims

1. A low-maintenance coating on a glass sheet, the coating comprising a first base film positioned directly over a first major surface of the glass sheet and a second photocatalytic film positioned directly over the first base film, wherein the first base film includes a base film and has a thickness of less than about 100 angstroms, and wherein the second film includes a photocatalytic film and has a thickness of less than about 100 angstroms.

2. The low-maintenance coating of claim 1 wherein the base film is silica.

3. The low-maintenance coating of claim 2 wherein the coated first major surface is in periodic contact with rain.

4. The low-maintenance coating of claim 1 wherein the photocatalytic film is titania.

5. The low-maintenance coating of claim 1 wherein the thickness of the first base film is between about 70 angstroms and about 100 angstroms.

6. The low-maintenance coating of claim 1 wherein the thickness of the second photocatalytic film is between about 30 angstroms and about 120 100 angstroms.

7. The low-maintenance coating of claim 1 wherein the glass sheet is a window pane mounted in a window frame, and wherein the coated first major surface is exposed to an outdoor environment.

8. The low-maintenance coating of claim 1 wherein the first base film consists essentially of silica and the second photocatalytic film consists essentially of titania.

9. The low-maintenance coating of claim 8 wherein the silica is silicon dioxide, and the titania is titanium dioxide or substoichiometric titanium oxide.

10. The low-maintenance coating of claim 1 wherein the first base and second photocatalytic films are both sputtered films.

16. The low-maintenance coating of claim 2 wherein the base film further comprises an oxidized electrically conductive material.

17. The low-maintenance coating of claim 16 wherein the electrically conductive material is aluminum.

18. The low-maintenance coating of claim 8 wherein the base film has a thickness of between about 70 angstroms and about 100 angstroms, and the photocatalytic film has a thickness of between about 30 angstroms and about 100 angstroms.

11. A low-maintenance coating on a glass sheet, the coating comprising a first film positioned directly over a first major surface of the glass sheet and a second film positioned directly over the first film, wherein the first film consists essentially of silica and has a thickness of between about 30 angstroms and about 100 angstroms, and wherein the second film consists essentially of titania and has a thickness of less than 100 angstroms but greater than about 30 angstroms.

12. The low-maintenance coating of claim 11 wherein the second film has a thickness of less than about 80 angstroms.

13. The low-maintenance coating of claim 11 wherein the silica of the first film contains aluminum oxide.

14. The low-maintenance coating of claim 11 wherein the silica of the first film includes an electrically conductive material present in oxidized form.

15. The low-maintenance coating of claim 14 wherein the second film is an outermost film of the coating.

19. A low-maintenance coating on a substrate, the coating comprising a base film extending directly from a first major surface of the substrate to a thickness of less than about 100 angstroms, and a photocatalytic film extending directly from a surface of the base film to a thickness of less than about 100 angstroms.

20. The low-maintenance coating of claim 19 wherein the base film consists essentially of silica and the photocatalytic film consists essentially of titania.

21. The low-maintenance coating of claim 19 wherein the base and photocatalytic films are both sputtered films.

22. The low-maintenance coating of claim 19 wherein the base film extends directly from the first major surface of the substrate to a thickness of between about 70 angstroms and about 100 angstroms, and the photocatalytic film extends directly from the surface of the base film to a thickness of between about 30 angstroms and about 100 angstroms.