Double silver low-emissivity and solar control coatings

• US 20030049464A1
• Filed: 09/04/2001
• Published: 03/13/2003
• Est. Priority Date: 09/04/2001
• Status: Abandoned Application

• Current Assignee: AFG Industries Incorporated (AGC, Inc.)
• Original Assignee: AFG Industries Incorporated (AGC, Inc.)
• Inventors: Glenn, Darin, Dannenberg, Rand, Johnson, Herb, Countrywood, Joe, Sieck, Peter A.
• Application Number:
  US09/944,372
• Publication Number:
  US 20030049464A1
• Time in Patent Office: Days
• US Class Current: 428/432
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• 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 17/3626 one layer at least containing a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3639 Multilayers containing at least two functional metal layers
• CPC Class Codes: C03C 17/3644 the metal being silver
• CPC Class Codes: C03C 17/3652 the coating stack containing at least one sacrificial layer to protect the metal from oxidation
• CPC Class Codes: C03C 17/366 Low-emissivity or solar control coatings
• CPC Class Codes: C03C 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: G02B 5/282 reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection
• CPC Class Codes: Y10T 428/12618 Plural oxides
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A low-emissivity multilayer coating includes, in order outward from the substrate, a first layer including a layer containing titanium oxide, a layer containing silicon nitride, or a sublayer layer containing titanium oxide in combination with a sublayer containing silicon nitride; a second layer including Ag; a third layer including at least one layer selected from titanium oxide layers and silicon nitride layers; a fourth layer including Ag; and a fifth layer including silicon nitride. The color of the coatings can be varied over a wide range by controlling the thicknesses of the layers of titanium oxide, silicon nitride and Ag. A diffusion barrier of oxidized metal protects relatively thin, high electrical conductivity, pinhole free Ag films grown preferentially on zinc oxide substrates. Oxygen and/or nitrogen in the Ag films improves the thermal and mechanical stability of the Ag. Dividing the first layer of titanium oxide, the Ag layers, and/or the third layer with a sublayer of oxidized metal can provide greater thermal and mechanical stability to the respective layers.

Claims

1. A low-emissivity coating on a substrate, the coating comprising, in numerical order outward from the substrate,

a first layer including at least one layer selected from titanium oxide layers and silicon nitride layers;

a second layer including Ag;

a third layer including at least one layer selected from titanium oxide layers and silicon nitride layers;

a fourth layer including Ag; and

a fifth layer including silicon nitride.

2. The coating according to claim 1, wherein the first layer is from 5 to 30 nm thick.

3. The coating according to claim 1, wherein the titanium oxide in the first layer is amorphous.

4. The coating according to claim 1, wherein the third layer comprises at least one of a TiO₂ layer and a Si₃N₄ layer.

5. The coating according to claim 1, wherein the third layer comprises a superlattice of titanium oxide and silicon nitride.

6. The coating according to claim 1, wherein at least one of the second layer and the fourth layer consists of, in numerical order outward from the substrate,

a first sublayer including a zinc oxide;

a second sublayer including Ag; and

a third sublayer including an oxidized metal.

7. The coating according to claim 6, wherein the zinc oxide comprises nitrogen.

8. The coating according to claim 6, wherein the oxidized metal comprises an at least partially oxidized Ni—

Cr alloy.

9. The coating according to claim 1, wherein the Ag in at least one of the second layer and the fourth layer further comprises at least one of oxygen and nitrogen.

10. The coating according to claim 1, wherein the Ag in at least one of the second layer and the fourth layer further comprises a means for strengthening the Ag against thermally induced changes.

11. The coating according to claim 1, wherein at least one of the first layer, the second layer, the third layer, and the fourth layer is divided by a layer of an oxidized metal.

12. The coating according to claim 11, wherein the oxidized metal is an at least partially oxidized Ni—

Cr alloy.

13. The coating according to claim 1, wherein at least one layer of the first layer, the second layer, the third layer, and the fourth layer is divided by layer including a means for strengthening the at least one layer against thermally induced changes.

14. A method of making a low-emissivity coating on a substrate, the method comprising

depositing at least one layer including Ag;

and

forming the coating of claim 1.

15. The method according to claim 14, wherein the depositing comprises sputtering.

16. A method of making a low-emissivity coating on a substrate, the method comprising

a step for depositing at least one layer including Ag on a substrate;

and

forming the coating of claim 1.

17. A low-emissivity coating on a substrate, the coating comprising, in numerical order outward from the substrate,

a first layer including at least one layer selected from titanium oxide layers and silicon nitride layers;

a second layer including a first means for reflecting infrared radiation;

a third layer having an index of refraction greater than or equal to 1.9 at a wavelength of 550 nm;

a fourth layer including a second means for reflecting infrared radiation; and

a fifth layer including a means for protecting the coating from abrasion.

18. The coating according to claim 17, wherein

at least one of the first means for reflecting infrared radiation and the second means for reflecting infrared radiation consists of, in numerical order outward from the substrate, a first sublayer, a second sublayer including Ag, and a third sublayer;

the first sublayer includes a means for preferentially orienting a crystal structure of the second sublayer; and

the third sublayer includes an oxidized metal.

19. The coating according to claim 18, wherein the oxidized metal comprises an at least partially oxidized Ni—

Cr alloy.

20. The coating according to claim 17, wherein

at least one of the first means for reflecting infrared radiation and the second means for reflecting infrared radiation consists of, in numerical order outward from the substrate, a first sublayer, a second sublayer including Ag, and a third sublayer;

the first sublayer includes a zinc oxide; and

the third sublayer includes a means for preventing the Ag in the second sublayer from corroding.

21. The coating according to claim 19, wherein the zinc oxide comprises nitrogen.

22. A low-emissivity coating on a transparent substrate, the coating comprising, in numerical order outward from the substrate,

a first layer including at least one layer selected from titanium oxide layers and silicon nitride layers;

a second layer including a zinc oxide;

a third layer including Ag;

a fourth layer including a first oxidized metal;

a fifth layer including at least one layer selected from titanium oxide layers and silicon nitride layers;

a sixth layer including a zinc oxide;

a seventh layer including Ag;

an eight layer including a second oxidized metal; and

a ninth layer including silicon nitride.