Coating glass

• US 6,540,884 B1
• Filed: 08/02/1999
• Issued: 04/01/2003
• Est. Priority Date: 08/04/1998
• Status: Expired due to Fees

• Current Assignee: Flachglas AG, Pilkington PLC
• Original Assignee: Pilkington PLC
• Inventors: Nöthe, Axel, Siddle, John Robert
• Primary Examiner(s): VerSteeg, Steven H.
• Application Number:
  US09/365,667
• Time in Patent Office: 1,338 Days
• Field of Search: 204/192.15, 204/192.12, 204/192.22, 427/377, 427/383.5
• US Class Current: 204/192.22
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3605 Coatings of the type glass/metal/inorganic compound
• CPC Class Codes: C03C 17/3613 Coatings of type glass/inorganic compound/metal/inorganic compound/metal/other
• CPC Class Codes: C03C 17/3615 Coatings of the type glass/metal/other inorganic layers, at least one layer being non-metallic
• CPC Class Codes: C03C 17/3618 Coatings of type glass/inorganic compound/other inorganic layers, at least one layer being metallic
• CPC Class Codes: C03C 17/366 Low-emissivity or solar control coatings
• CPC Class Codes: C03C 17/3681 the multilayer coating being used in glazing, e.g. windows or windscreens

Abstract

A process for the production of a low emissivity coating on a glass substrate comprising, in sequence, depositing a reflective metal layer, and reactively sputtering a metal oxide layer over the metal layer in the presence of an oxygen scavenger. The oxygen scavenger is preferably a hydrocarbon, in particular methane. The metal oxide layer may comprise tin oxide, zinc oxide, tungsten oxide and other metal oxides are also likely to be suitable.

Claims

1. A process for the production of an electrically conductive low emissivity coating on a glass substrate, comprising, in sequence:

(a) providing a glass substrate having at least one surface;

(b) depositing a reflective metal layer above a surface of the glass substrate;

(c) providing an atmosphere for reactive sputtering of a metal oxide, said atmosphere containing methane as an oxygen scavenger; and

(d) depositing a metal oxide layer over the reflective metal layer by reactive sputtering in said atmosphere.

2. A process according to claim 1 wherein the atmosphere in which the metal oxide layer is reactively sputtered further contains an oxidizing gas.

3. A process according to claim 2 wherein the oxidizing gas is oxygen.

4. A process according to claim 1 wherein the metal oxide layer comprises tin oxide, zinc oxide or tungsten oxide.

5. A process according to claim 1 wherein the reflective metal layer is a silver layer.

6. A process according to claim 1 wherein the coating has a sheet resistance, the sheet resistance of the coating increases by less than 25% on overcoating with the metal oxide layer.

7. A process according to claim 1 wherein the coating has a sheet resistance, the sheet resistance of the coating increases by less than 20% on overcoating with the metal oxide layer.

8. A process according to claim 1 wherein the coating has a sheet resistance, the sheet resistance of the coating is below 12 Ω

/square after overcoating with the metal oxide layer.

9. A process to claim 1 wherein the process additionally comprises heat treating the coated glass substrate in an atmosphere containing oxygen.

10. A process according to claim 9 wherein the coating has a sheet resistance, the sheet resistance of the coating is below 30 Ω

/square after the glass has been overcoated with the metal oxide layer and then heat-treated in an atmosphere containing oxygen.

11. A process according to claim 1 wherein the reflective metal layer has a thickness in the range 8-18 nm.

12. A process according to claim 1 wherein the coating has more than one reflective metal layer.

13. A process according to claim 1 wherein the process comprises an additional step of depositing a protective layer between the reflective metal layer and the metal oxide layer.