Low-maintenance coatings, and methods for producing low-maintenance coatings

• US 8,506,768 B2
• Filed: 09/03/2010
• Issued: 08/13/2013
• Est. Priority Date: 09/14/2007
• Status: Active Grant

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Inventors: Myli, Kari B., Krisko, Annette J., Brownlee, James E., Pfaff, Gary L.
• Primary Examiner(s): MCDONALD, RODNEY GLENN
• Application Number:
  US12/875,221
• Publication Number:
  US 20100326817A1
• Time in Patent Office: 1,075 Days
• Field of Search: 204/192.26, 204/192.27, 204/192.28
• US Class Current: 204/192.26
• 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 both titanium oxide and tungsten oxide. The invention also provides methods and equipment for depositing such coatings.

Claims

1. A method comprising:

depositing a low-maintenance coating on a major surface of a glass sheet, the low-maintenance coating including a base film and a functional film,

wherein the base film is deposited by a sputtering technique where at least one target is sputtered in an atmosphere into which both inert gas and reactive gas are flowed and an inflow rate for the inert gas divided by an inflow rate for the reactive gas is between 0.4 and 9, and

wherein the functional film is deposited by a sputtering technique that uses at least one target having a sputterable material comprising both titanium oxide and tungsten oxide, the titanium oxide comprising TiO and TiO₂.

2. The method of claim 1 wherein the sputtering technique for depositing the base film involves a plurality of targets each carrying a sputterable material consisting essentially of:

1) one or more metals, or

     2) one or more semi-metals, or

     3) at least one metal and at least one semi-metal, and the sputtering technique for depositing the functional film involves a plurality of oxide targets each carrying the sputterable material comprising both titanium oxide and tungsten oxide.

3. The method of claim 2 wherein the sputterable material used in depositing the base film includes silicon.

4. The method of claim 1 wherein the inert gas is argon and the reactive gas is oxygen or nitrogen.

5. The method of claim 1, wherein the at least one target having the sputterable material comprising both titanium oxide and tungsten oxide is at least one target consisting essentially of titanium oxide and tungsten oxide, wherein titanium is present at about 59-74 weight percent of the target, tungsten is present at about 1.4-3.8 weight percent of the target, and oxygen is present at about 23.3-38.6 weight percent of the target.

6. The method of claim 1, wherein the sputtering technique for depositing the base film and the sputtering technique for depositing the functional film both use magnetron sputtering.

7. The method of claim 1, wherein the base film is deposited to a thickness of less than about 300 angstroms.

8. The method of claim 1, wherein the functional film is deposited to a thickness of less than 200 angstroms.

9. The method of claim 1, wherein the functional film is deposited to a thickness of less than 150 angstroms.

10. The method of claim 1, wherein the low-maintenance coating is deposited such that the base film and the functional film have a combined thickness of less than about 350 angstroms.

11. The method of claim 1, wherein the functional film is deposited by sputtering the at least one target having the sputterable material comprising both titanium oxide and tungsten oxide in an atmosphere into which both inert gas and reactive gas are flowed, and an inflow rate for the inert gas divided by an inflow rate for the reactive gas is between 0.4 and 6.

12. The method of claim 1, wherein the depositing of the low-maintenance coating is performed such that the low-maintenance coating has an average surface roughness of between 0.4 and 3.0 nm.

13. The method of claim 1, wherein the low-maintenance coating has a physical thickness and an area, the physical thickness varying by less than 20 angstroms over the area of the low-maintenance coating.

14. A method comprising:

depositing a low-maintenance coating on a major surface of a glass sheet, the low-maintenance coating including a base film and a functional film,

wherein the base film is deposited by a sputtering technique where at least one target is sputtered in an atmosphere into which both inert gas and reactive gas are flowed and an inflow rate for the inert gas divided by an inflow rate for the reactive gas is between 0.4 and 9, and

wherein the functional film is deposited by a sputtering technique that uses at least one target having a sputterable material comprising both titanium oxide and tungsten oxide, the titanium oxide comprising TiO and TiO₂, and

the depositing of the low-maintenance coating is performed such that the functional film defines an exposed outermost face of the low-maintenance coating.

15. The method of claim 14, wherein the base film is deposited to a thickness of less than about 300 angstroms.

16. The method of claim 14, wherein the functional film is deposited to a thickness of less than 200 angstroms.

17. The method of claim 14, wherein the functional film is deposited to a thickness of less than 150 angstroms.

18. The method of claim 14, wherein the low-maintenance coating is deposited such that the base film and the functional film have a combined thickness of less than about 350 angstroms.

19. The method of claim 14, wherein the functional film is deposited by sputtering the at least one target having the sputterable material comprising both titanium oxide and tungsten oxide in an atmosphere into which both inert gas and reactive gas are flowed, and an inflow rate for the inert gas divided by an inflow rate for the reactive gas is between 0.4 and 6.

20. The method of claim 14, wherein the depositing of the low-maintenance coating is performed such that the low-maintenance coating has an average surface roughness of between 0.4 and 3.0 nm.