Coated article with IR reflecting layer and method of making same

• US 8,409,717 B2
• Filed: 04/21/2008
• Issued: 04/02/2013
• Est. Priority Date: 04/21/2008
• Status: Expired due to Fees

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Centre Luxembourgeois de Recherches pour le Verre et la Ceramique SA, Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Lao, Jingyu, Lingle, Philip J., Boyce, Brent, Disteldorf, Bernd, Blacker, Richard
• Primary Examiner(s): McNeil, Jennifer
• Assistant Examiner(s): COLGAN, LAUREN ROBINSON
• Application Number:
  US12/081,789
• Publication Number:
  US 20090263596A1
• Time in Patent Office: 1,807 Days
• Field of Search: 428/426, 428/432, 428/433, 428/434, 428/688, 428/689, 428/699, 428/701, 428/702
• US Class Current: 428/432
• CPC Class Codes: B32B 17/06 comprising glass as the main or only constituent of a layer, next to another layer of a specific material
• CPC Class Codes: B32B 2255/20 Inorganic coating
• CPC Class Codes: B32B 2255/28 Multiple coating on one surface
• CPC Class Codes: B32B 2307/304 Insulating
• CPC Class Codes: B32B 2307/412 Transparent
• CPC Class Codes: B32B 2307/416 Reflective
• CPC Class Codes: C03C 17/2453 Coating containing SnO2
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• 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 17/3634 one layer at least containing carbon, a carbide or oxycarbide
• 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 17/3681 the multilayer coating being used in glazing, e.g. windows or windscreens
• CPC Class Codes: C03C 2217/21 Oxides
• CPC Class Codes: C03C 2217/211 SnO2
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2217/216 ZnO
• CPC Class Codes: C03C 2217/219 : CrOx, MoOx, WOx
• CPC Class Codes: C03C 2217/256 : Ag
• CPC Class Codes: C03C 2217/281 : Nitrides
• CPC Class Codes: C03C 2217/70 : Properties of coatings
• CPC Class Codes: C03C 2218/154 : by sputtering
• CPC Class Codes: C03C 2218/156 : by magnetron sputtering
• CPC Class Codes: C23C 14/0652 : Silicon nitride
• CPC Class Codes: C23C 14/086 : of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: E06B 2009/2417 : Light path control; means to control reflection
• CPC Class Codes: E06B 3/6715 : specially adapted for increased thermal insulation or for controlled passage of light E06B3/66323 takes precedence; coating of glass pains C03C17/00; devices or arrangements for controlling the intensity, colour, phase, polarisation or direction of light G02F1/00
• CPC Class Codes: E06B 9/24 : Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; Slat blindsoperating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00
• CPC Class Codes: Y10T 428/265 : 1 mil or less

Abstract

Example embodiments of this invention relate to a coated article including an infrared (IR) reflecting layer of a material such as silver or the like, for use in an insulating glass (IG) window unit for example. In certain example embodiments, the coating is a single-silver type coating, and includes an overcoat including an uppermost layer of or including silicon nitride and a layer of or including tin oxide immediately under and contacting the silicon nitride based overcoat. In certain example embodiments, the thicknesses of the silicon nitride based overcoat and the tin oxide based layer are balanced (e.g., substantially equal, or equal plus/minus about 10%). It has surprisingly been found that such balancing results in an improvement in thermal cycling performance and improved mechanical durability. In certain example embodiments, the coating may realize surprisingly good substantially neutral film side reflective coloration, and may achieve an improved visible transmission, SHGC ratio and low U-values. Moreover, in certain example embodiments, stress in the overcoat of the coating may be reduced by reducing nitrogen gas flow (N₂ ml/kW) and cathode power during a sputter-deposition process, thereby further improving thermal cycling performance.

Claims

1. A coated article including a coating supported by a glass substrate, the coating comprising:

at least one dielectric layer;

a layer comprising zinc oxide over the at least one dielectric layer;

an infrared (IR) reflecting layer comprising silver on the glass substrate, located over and directly contacting the layer comprising zinc oxide, wherein the coating includes only one IR reflecting layer;

a layer comprising an oxide of Ni and/or Cr located over and directly contacting the IR reflecting layer comprising silver;

an overcoat comprising a layer comprising tin oxide located over the oxide of Ni and/or Cr and a layer comprising silicon nitride located over and contacting the layer comprising tin oxide;

wherein, in the overcoat, the layer comprising tin oxide and the layer comprising silicon nitride have substantially equal thicknesses plus/minus 10% in order to improve thermal cycling performance and mechanical durability of the coating and the layer comprising tin oxide and the layer comprising silicon nitride each have a thickness of from about 160-180 Å

.

2. The coated article of claim 1, wherein the at least one dielectric layer comprises a first layer comprising silicon nitride contacting the glass substrate, a layer comprising titanium oxide over and contacting the first layer comprising silicon nitride, and a second layer comprising silicon nitride over and contacting the layer comprising titanium oxide, and wherein the layer comprising zinc oxide directly contacts the second layer comprising silicon nitride.

3. The coated article of claim 1, wherein the coating has a sheet resistance (R_s) of no greater than 11 ohms/square.

4. The coated article of claim 1, wherein the coating has a sheet resistance (R_s) of no greater than 10 ohms/square.

5. The coated article of claim 1, wherein the coated article is an insulating glass (IG) window unit.

6. The coated article of claim 5, wherein the IG unit has an SHGC value of at least 0.68, a visible transmission of at least 74.5%, and an Energy Rating of at least 29.

7. The coated article of claim 5, wherein the IG unit has an SHGC value of at least 0.65, a visible transmission of at least 70%, and an Energy Rating of at least 25.

8. The coated article of claim 7, wherein the IG unit has a U-value of no greater than 0.30 Btu/h ft F.

9. The coated article of claim 7, wherein the IG unit comprises at least an interior glass substrate and an exterior glass substrate, wherein the coating is provided on a surface of the interior glass substrate facing a gap between the interior and exterior glass substrates, and wherein the IG unit has, as viewed from an exterior of a building in which the IG unit is provided, a reflective a* value of from about −

4 to 0, and a reflective b* value of from about −

1 to +2.5.