Low-maintenance coating technology

• US 7,820,296 B2
• Filed: 09/12/2008
• Issued: 10/26/2010
• Est. Priority Date: 09/14/2007
• Status: Expired due to Fees

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Inventors: German, John, Hartig, Klaus, Krisko, Annette J., Myli, Kari B.
• Primary Examiner(s): Blackwell; Gwendolyn
• Application Number:
  US12/209,788
• Publication Number:
  US 20090075067A1
• Time in Patent Office: 774 Days
• Field of Search: 428/428, 428/432, 428/689, 428/697, 428/701, 428/702
• US Class Current: 428/432
• CPC Class Codes: C03C 17/002 for flat glass, e.g. float glass
• CPC Class Codes: C03C 17/2456 Coating containing TiO2
• CPC Class Codes: C03C 17/3411 with at least two coatings of inorganic materials C03C17/36, C03C17/42 take precedence
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2217/219 CrOx, MoOx, WOx
• CPC Class Codes: C03C 2217/23 Mixtures
• CPC Class Codes: C03C 2217/71 Photocatalytic coatings
• CPC Class Codes: C03C 2217/91 Coatings containing at least one layer having a composition gradient through its thickness
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: C23C 14/024 Deposition of sublayers, e.g. to promote adhesion of the coating C23C14/027 takes precedence
• CPC Class Codes: C23C 14/083 of refractory metals or yttrium
• CPC Class Codes: C23C 14/3464 using more than one target C23C14/56 takes precedence
• CPC Class Codes: C23C 14/352 using more than one target C23C14/56 takes precedence
• CPC Class Codes: Y10T 428/261 In terms of molecular thickness or light wave length
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

The invention provides a substrate bearing a low-maintenance coating. In some embodiments, the coating includes a low-maintenance film that includes a thickness of film comprising titania, wherein only part of that thickness includes tungsten. The thickness includes an inner portion and an outer portion, the outer portion being the part that includes tungsten. The invention also provides methods and equipment for depositing such coatings.

Claims

1. A substrate having a major surface on which there is a low-maintenance coating, the low-maintenance coating including a thickness of film comprising titania, said thickness being less than 250 Å

, wherein only part of that thickness includes tungsten oxide, said thickness including an inner portion and an outer portion, the inner portion being closer to the substrate than is the outer portion, the outer portion being the part that includes tungsten oxide, wherein the outer portion defines an exposed, outermost face of the low-maintenance coating, wherein the coating has a region ratio of between about 0.2 and 7, the region ratio being the thickness of the outer portion divided by the thickness of the inner portion, and wherein said coated substrate has a haze value of less than 0.30.

2. The substrate of claim 1 wherein the thickness of the outer portion is no more than about 90 Å

.

3. The substrate of claim 1 wherein said thickness of film comprising titania is less than about 150 Å

.

4. The substrate of claim 1 wherein the outer portion is a substantially homogenous film comprising both titanium dioxide and tungsten oxide.

5. The substrate of claim 4 wherein the inner portion is a substantially homogenous film consisting essentially of titania.

6. The substrate of claim 1 wherein the outer portion has a tungsten load characterized by a metal-only atomic ratio of between about 0.01 and about 0.34, this ratio being the number of tungsten atoms in the outer portion divided by the number of titanium atoms in the outer portion.

7. The substrate of claim 1 wherein the low-maintenance coating includes a base film between the major surface of the substrate and said thickness of film comprising titania.

8. The substrate of claim 7 wherein the base film and said thickness of film comprising titania have a combined thickness of less than about 150 Å

.

9. The substrate of claim 7 wherein the base film comprises silica.

10. The substrate of claim 7 wherein the base film comprises alumina.

11. The substrate of claim 7 wherein the base film has a thickness of less than about 100 Å

.

12. The substrate of claim 1 wherein a base film is provided between said thickness of film comprising titania and the major surface of the substrate, and an intermediate film is provided between the base film and said thickness of film comprising titania.

13. The substrate of claim 12 wherein the base film and the intermediate film each have a thickness of less than 100 Å

.

14. The substrate of claim 13 wherein base film comprises alumina and the intermediate film comprises silica.

15. The substrate of claim 14 wherein the base film comprises alumina at a thickness of less than about 50 Å

and the intermediate film comprises silica at thickness of less than about 50 Å

.

16. The substrate of claim 1 wherein a transparent conductive oxide film is provided between the major surface of the substrate and the low-maintenance coating.

17. The substrate of claim 16 wherein the substrate is a transparent pane that is part of a multiple-pane insulating glazing unit having a between-pane space, wherein the major surface bearing the low-maintenance coating faces away from the between-pane space of the unit.

18. The substrate of claim 1 wherein the substrate is part of a triple-pane insulating glazing unit.

19. The substrate of claim 1 wherein the substrate is part of a multiple-pane insulating glazing unit having two exterior major surfaces each bearing a low-maintenance coating comprising titania.

20. A substrate having a major surface on which the following films are coated in sequence, moving outwardly from the major surface:

i) a functional film comprising a material selected from the group consisting of indium tin oxide and fluorine-containing tin oxide; and

ii) a thickness of film comprising titania, wherein only part of that thickness includes tungsten oxide, said thickness including an inner portion and an outer portion, the inner portion being closer to the substrate than is the outer portion, the outer portion being the part that includes tungsten oxide, wherein the outer portion defines an exposed, outermost face, and wherein a thickness ratio defined as said thickness of film comprising titania divided by the thickness of the functional film is between about 0.004 and about 0.08, and wherein a region ratio defined as the thickness of the outer portion divided by the thickness of the inner portion is between about 0.2 and 7.

21. The substrate of claim 20 wherein said thickness ratio is between about 0.004 and about 0.025.

22. The substrate of claim 20 wherein between the functional film and said thickness of film comprising titania there is a layer having a thickness of less than 100 Å

.

23. The substrate of claim 20 wherein between the functional film and said thickness of film comprising titania there is a layer comprising silica, alumina, or both.

24. The substrate of claim 20 wherein between the functional film and said thickness of film comprising titania there are two layers of film having a combined thickness of less than 100 Å

.

25. A substrate having a major surface on which there is both a transparent conductive oxide film and a low-maintenance coating, the transparent conductive oxide film being closer to the substrate than is the low-maintenance coating, the low-maintenance coating including a thickness of film comprising titania, wherein only part of that thickness includes tungsten oxide, said thickness including an inner portion and an outer portion, the inner portion being closer to the substrate than is the outer portion, the outer portion being the part that includes tungsten oxide, wherein the outer portion defines an exposed, outermost face of the low-maintenance coating, wherein a region ratio defined as the thickness of the outer portion divided by the thickness of the inner portion is between about 0.2 and 7, wherein between the transparent conductive oxide film and said thickness of film comprising titania there are two layers including one comprising silica and one comprising alumina.

26. The substrate of claim 25 wherein said two layers have a combined thickness of less than 100 angstroms.

27. The substrate of claim 25 wherein said layer comprising alumina is closer to the substrate than is said layer comprising silica.

28. The substrate of claim 25 wherein said layer comprising alumina is contiguous to said layer comprising silica.

29. The substrate of claim 25 wherein the substrate is a transparent pane that is part of a multiple-pane insulating glazing unit having a between-pane space, wherein the major surface bearing the transparent conductive oxide film and the low-maintenance coating faces away from the between-pane space of the unit.