Low transmission heat-reflective glazing materials

• US 5,306,547 A
• Filed: 12/14/1990
• Issued: 04/26/1994
• Est. Priority Date: 12/14/1990
• Status: Expired due to Term

• Current Assignee: Southwall Technologies, Inc. (Eastman Chemical Company)
• Original Assignee: Southwall Technologies, Inc. (Eastman Chemical Company)
• Inventors: Meyer, Stephen F., Hood, Thomas G.
• Primary Examiner(s): Loney, Donald J.
• Application Number:
  US07/628,893
• Time in Patent Office: 1,229 Days
• Field of Search: 428/34, 428/262, 428/213, 428/432, 428/433, 428/434, 428/458, 428/469, 428/472, 428/689, 428/699, 428/702, 428/333, 428/701, 52/788, 52/789, 156/107, 156/109, 427/165, 427/166, 427/419.2, 427/419.3, 359/360, 359/589
• US Class Current: 428/213
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3613 Coatings of type glass/inorganic compound/metal/inorganic compound/metal/other
• 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 17/38 at least one coating being a coating of an organic material
• CPC Class Codes: C03C 17/42 at least one coating of an organic material and at least one non-metal coating
• 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: 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: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/261 In terms of molecular thickness or light wave length
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31826 Of natural rubber

Abstract

High-performance heat-reflective films having a metallic silver layer bounded by two dielectric layers are disclosed. The thickness of the layers is selected to insure high levels of heat rejection but relatively high levels of light transmission together with a substantial level of color neutrality.

Claims

1. A heat-reflective glazing material comprising a transparent substrate having a surface and a composite film on the surface,

the composite film having a single discrete layer consisting essentially of metallic silver of from 270Å

to 400Å

in thickness disposed between two discrete layers of transparent dielectric, one a bottom layer located between the substrate and the silver layer and the other a top layer located on top of the silver layer,

the bottom layer being at least about 30Å

in physical thickness and the top layer having an index of refraction at 550 nm of 1.75 to 2.50 and being from 950Å

to 1800Å

in optical thickness, the thickness of the dielectric layers being selected so as to yield a composite film having a total transmission of available solar energy in the visible wavelengths of 380-750 nm of less than 40% and a reflection of solar energy in all wavelengths of at least about 50% and a transmitted and reflected color neutrality such that the maximum transmission at any wavelength between 400Å and

700Å

(Tmax(400-700)) is not greater than 1.7 times the minimum transmission at any wavelength between 400Å and

700Å

(Tmin(400-700)) and the maximum reflectance at any wavelength between 400Å and

700Å

(Rmax(400-700)) is not greater than 1.7 times the minimum reflectance at any wavelength between 400Å and

700Å

(Rmin(400-700)), and absolute values for each of L*a*b* color space coordinates, Ta*, Tb*, Ra* and Rb* of less than 6.

2. The glazing material of claim 1 wherein the three layers of the composite film are each a sputter-deposited layer.

3. The glazing material of claim 2 wherein the substrate is glass.

4. A high performance double-pane window glazing comprising two panes of glass held in parallel spaced apart relationship thereby defining an inside pane and outside pane and an internal cavity wherein the outside pane is the glazing material of claim 3 with the composite film facing into the cavity.

5. The glazing material of claim 3 having an interior and an exterior surface and a composite film on the interior surface.

6. The glazing material of claim 3 having an interior and an exterior surface and a composite film on the exterior surface.

7. The glazing material of claim 2 wherein the substrate is plastic sheet.

8. A high performance double-pane window glazing comprising two panes of glass held in parallel spaced apart relationship thereby defining an inside pane and outside pane and an internal cavity wherein the outside pane is a sheet of glass having the glazing material of claim 7 laminated to the side facing into the cavity.

9. The glazing material of claim 7 held in parallel separation between two spaced-apart sheets of glass, thereby creating a triple-sheet glazing structure.

10. The glazing material of claim 7 laminated to a glass sheet.

11. The glazing material of claim 1 additionally comprising a protective layer of hardcoat deposited over the composite layer.

12. A solar sheet control glazing material comprising a sheet of clear float glass from about 1/8 inch thick through about 1/4 inch thick and having an outer solar-impacting surface and an inner surface having sputter-deposited on its inner surface a three-layer composite heat-reflective sputter-deposited film made up of a 290Å

to 380Å

thick layer consisting essentially of silver deposited between a 30Å

to 1000Å

which transparent dielectric underlayer and a 500Å

to 950Å

which top layer of transparent dielectric having an index of refraction of from 1.75 to 2.50 and an optical thickness of from 950Å

to 1800Å

.

13. The glazing material of claim 12 wherein the dielectric for both the underlayer and the top layer is a metal oxide.

14. The glazing material of claim 13 wherein the dielectric for both the underlayer and the top layer is InO₂.

15. The glazing material of claim 14 wherein the silver layer is about 310-315Å

thick and the two lnO₂ layers are each about 565-575Å

thick.

16. The glazing material of claim 14 wherein the silver layer is about 360-370Å

thick and the two InO₂ layers are each about 575-585Å

thick.

17. A heat-control glazing material comprising a flexible poly(ethylene terephthalate) film of from 0.5 to 3 mils in thickness having sputter-deposited on one of its surfaces a three-layer composite heat-reflective sputter-deposited film made up of a 290Å

-to-380Å

-thick layer consisting essentially of silver deposited between a 30Å

to 1000Å

thick transparent dielectric underlayer and a 500Å

-to-950Å

-thick top layer of transparent dielectric having an index of refraction of from 1.75 to 2.50 and an optical thickness of from 950Å

to 1800Å

.

18. The glazing material of claim 17 wherein the dielectric for both the underlayer and the top layer is a metal oxide.

19. The glazing material of claim 18 wherein the dielectric for both the underlayer and the top layer is InO₂.

20. The glazing material of claim 19 wherein the silver layer is about 310-315Å

thick and the two InO₂ layers are each about 565-575Å

thick.

21. The glazing material of claim 19 wherein the silver layer is about 360-370Å

thick and the two InO₂ layers are each about 575-585Å

thick.