IG window unit including double silver coating having increased SHGC to U-value ratio, and corresponding coated article for use in IG window unit or other window

• US 9,302,936 B2
• Filed: 01/09/2015
• Issued: 04/05/2016
• Est. Priority Date: 09/03/2013
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Wuillaume, Francis, Boyce, Brent
• Primary Examiner(s): Robinson, Lauren
• Assistant Examiner(s): COLGAN, LAUREN ROBINSON
• Application Number:
  US14/592,970
• Publication Number:
  US 20150118465A1
• Time in Patent Office: 452 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: 1/1
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• 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 17/366 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 2217/211 SnO2
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2217/216 ZnO
• CPC Class Codes: C03C 2217/228 Other specific oxides
• CPC Class Codes: C03C 2217/281 Nitrides
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: E06B 2009/2417 Light path control; means to control reflection
• CPC Class Codes: E06B 3/67 characterised by additional arrangements or devices for heat or sound insulation or for controlled passage of light
• 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 428/2495 Thickness [relative or absolute]

Abstract

An insulating glass (IG) window unit includes first and second substrates, and a low-emissivity (low-E) coating supported by one of the substrates. The low-E coating has two silver based infrared (IR) reflecting layers and allows the IG window unit to realize an increased SHGC to U-value ratio, and an increased thickness ratio of an upper silver based layer of the coating to a bottom silver based layer of the coating. The low-E coating is designed to have a low film-side reflectance, so that for example when the low-E coating is used on surface number three of an IG window unit the IG window unit can realize reduced visible reflectance as viewed from the outside of the building on which the IG window unit is mounted or is to be mounted.

Claims

1. A coated article including a low-emissivity (low-E) coating on a substrate, the low-E coating comprising, moving away from the substrate:

a dielectric layer comprising silicon nitride;

a dielectric layer comprising titanium oxide;

a first lower contact layer comprising zinc oxide;

a first IR reflecting layer comprising silver located over and directly contacting the first lower contact layer;

a first upper contact layer comprising metal oxide located over and directly contacting the first IR reflecting layer comprising silver;

a layer comprising zinc stannate located over and directly contacting the first upper contact layer comprising metal oxide;

a layer consisting essentially of tin oxide located over and directly contacting the layer comprising zinc stannate;

a second lower contact layer comprising zinc oxide located over and directly contacting the layer consisting essentially of tin oxide;

wherein a total thickness of the layer comprising zinc stannate and the layer consisting essentially of tin oxide is from 600-900 Å

;

a second IR reflecting layer comprising silver located over and directly contacting the second lower contact layer;

a second upper contact layer located over and directly contacting the second IR reflecting layer comprising silver; and

a dielectric layer;

wherein the low-E coating has only two IR reflecting layers comprising silver, and wherein the low-E coating has a normal emissivity of no greater than 0.04;

wherein a ratio of a thickness of the first IR reflecting layer comprising silver to a thickness of the second IR reflecting layer comprising silver, calculated as the thickness of the first IR reflecting layer comprising silver divided by the thickness of the second IR reflecting layer comprising silver, is from 0.30 to 0.50 and provides a SHGC of at least 0.54; and

wherein the coated article, measured monolithically, has a visible transmission of at least about 70% and film side visible reflectance of no greater than 6.5%.

2. The coated article of claim 1, wherein the first upper contact layer comprises an oxide of Ni and/or Cr.