Heat load reduction windshield

• US 5,902,505 A
• Filed: 10/20/1993
• Issued: 05/11/1999
• Est. Priority Date: 04/04/1988
• Status: Expired due to Term

• Current Assignee: Vitro Flat Glass LLC (Compagnie De Saint-Gobain)
• Original Assignee: PPG Industries Incorporated (Nouryon BV)
• Inventors: Finley, James Joseph
• Primary Examiner(s): Walberg, Teresa
• Assistant Examiner(s): Robinson, Daniel Leon
• Application Number:
  US08/139,260
• Time in Patent Office: 2,029 Days
• Field of Search: 219/547, 219/203, 219/219, 428/623, 204/192.1, 204/192.28
• US Class Current: 219/547
• 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 17/3639 Multilayers containing at least two functional metal layers
• CPC Class Codes: C03C 17/3644 the metal being silver
• CPC Class Codes: C03C 17/3649 made of metals other than 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 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A multiple-layer, high transmittance, low emissivity coated article is disclosed comprising at least two infrared reflective metal layers alternatingly combined with at least three metal oxide antireflective layers to produce a coating with superior low emissivity and low visible reflectance, especially for use to reduce heat load in automobiles, wherein the coating furthermore is electroconductive for use in an electrically heatable transparency.

Claims

1. An electrically heatable transparency comprising a glass sheet, a transparent electroconductive coating on a major surface of the sheet, a first bus bar in contact with the coating along a first edge portion of the sheet, a second bus bar in contact with the coating along a second edge portion of the sheet opposite the first edge portion, an electroconductive extension extending from each end of the second bus bar to the first edge portion along third and fourth edge portions respectively, the extensions being electrically insulated from the coating, wherein the coating comprises:

a. a first transparent antireflective metal oxide film of an oxide reaction product of zinc and tin deposited on a surface of said glass sheet;

b. a primer layer of titanium on said first transparent antireflective film;

c. a transparent infrared reflective silver film deposited on said antireflective metal oxide layer;

d. a first transparent metal-containing primer layer comprising titanium deposited on said infrared reflective metallic film; and

e. a second transparent antireflective metal oxide film of an oxide reaction product of zinc and tin on said primer film;

in combination with

f. a second transparent metal-containing primer layer comprising titanium on said second antireflective metal oxide film;

g. a second transparent infrared reflective silver film deposited on said second transparent titanium primer film;

h. a third transparent metal-containing primer layer comprising titanium deposited on said second infrared reflective silver layer; and

i. a third transparent antireflective metal oxide film of an oxide reaction product of zinc and tin deposited on said third primer layer, and

j. a protective metal-containing overcoat deposited over said third antireflective metal oxide film.

2. A method for fabricating an electrically heatable coated glass transparency for heat load reduction comprising the steps of:

a. sputtering a metal in a reactive atmosphere comprising oxygen thereby depositing a first transparent metal oxide film comprising an oxide reaction product of zinc and tin on a surface of a transparent glass substrate;

b. sputtering a transparent, infrared reflective electroconductive metallic film over said transparent metal oxide film;

c. sputtering a first transparent primer layer comprising titanium over said transparent reflective electroconductive metallic film;

d. sputtering a second transparent metal oxide film comprising an oxide reaction product of zinc and tin over said first primer layer;

in combination with the steps of

e. sputtering a second transparent primer layer comprising titanium over said second transparent metal oxide film;

f. sputtering a second transparent infrared reflective metal film over said second primer layer;

g. sputtering a third transparent primer layer comprising titanium over said second infrared reflective layer;

h. sputtering a third transparent antireflective metal oxide layer comprising an oxide reaction product of zinc and tin over said third primer layer to produce an electroconductive multilayer coating; and

i. depositing a protective metal-containing overcoat deposited over said third antireflective oxide film, and

j. applying first and second bus bars to said substrate in contact with said coating.

3. A method for fabricating an electrically heatable coated and laminated transparency comprising the steps of:

a. placing a transparent glass substrate in a sputtering chamber;

b. sputtering zinc and tin in a reactive atmosphere comprising oxygen to deposit a first transparent zinc/tin oxide film on a surface of said substrate;

c. sputtering titanium to deposit a first primer layer on said oxide film;

d. sputtering silver in an inert atmosphere to deposit a first transparent silver film on said primer layer;

e. sputtering titanium to deposit a second primer layer on said first silver film;

f. sputtering zinc and tin in a reactive atmosphere comprising oxygen to deposit a second zinc/tin oxide film on said second primer layer;

g. sputtering titanium to deposit a third primer layer on said second oxide film;

h. sputtering silver in an inert atmosphere to deposit a second silver film on said third primer layer;

i. sputtering titanium to deposit a fourth primer layer on said second silver layer;

j. sputtering zinc and tin in a reactive atmosphere comprising oxygen to deposit a third zinc/tin oxide film on said fourth primer layer;

k. depositing a metal-containing protective coating over said third metal alloy oxide film;

l. applying first and second bus bars to said substrate in contact with said coating; and

m. laminating the coated transparent substrate with a transparent plastic substrate.