Solar control low-emissivity coatings

• US 7,807,248 B2
• Filed: 08/14/2007
• Issued: 10/05/2010
• Est. Priority Date: 08/14/2007
• Status: Active Grant

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Inventors: German, John R., Pfaff, Gary L.
• Primary Examiner(s): Sample; David R
• Assistant Examiner(s): Khan; Tahseen
• Application Number:
  US11/838,481
• Publication Number:
  US 20090047466A1
• Time in Patent Office: 1,148 Days
• Field of Search: 428/98, 428/220
• US Class Current: 428/98
• 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 17/3652 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: Y10T 428/24 Structurally defined web or sheet [e.g., overall dimension, etc.]

Abstract

A substrate bearing a solar control low-emissivity coating. The solar control low-emissivity coating includes one or more dielectric absorber films. In some embodiments, the dielectric absorber film has an absorption ratio of k_{380<λ<450 nm}/k_{650<λ<760 nm} that is less than 1.9.

Claims

1. A transparent substrate bearing a solar control low-emissivity coating, the coating comprising:

an innermost infrared-reflective film comprising silver and an outermost infrared-reflective film comprising silver;

a first dielectric absorber film between the substrate and the innermost infrared-reflective film, the first dielectric absorber film having a coefficient of extinction (k) of greater than 0.4 and having a neutral absorption ratio of k<sub>380<

λ

<

450 nm</sub>/k<sub>650<

λ

<

760 nm</sub> between 0.52 and 1.9;

a second dielectric absorber film further from the substrate than the outermost infrared-reflective film, the second dielectric absorber film having a coefficient of extinction (k) at 550 nm of greater than 0.4 and having a neutral absorption ratio of k<sub>380<

λ

<

450 nm</sub>/k<sub>650<

λ

<

760 nm</sub> between 0.52 and 1.9; and

the coating is either a double-type low-emissivity coating or a triple-type low emissivity coating,

if the coating is a double-type emissivity coating, then it has a middle coat located between said two infrared-reflective films and the middle coat consists essentially of transparent dielectric film; and

if the coating is a triple-type coating, then it further includes an intermediate infrared-reflective film comprising silver and it has two spacer coats each located between two of the infrared-reflective films and each consisting essentially of transparent dielectric film.

2. The substrate of claim 1 wherein the first and second dielectric absorber films both comprise nitride film.

3. The substrate of claim 1 wherein at least one of the first and second dielectric absorber films comprises a compound nitride including silicon nitride mixed with another nitride.

4. The substrate of claim 1 wherein the first and second dielectric absorber films both comprise a compound nitride including silicon nitride mixed with at least one other nitride selected from the group consisting of titanium nitride, niobium nitride, zirconium nitride, chromium nitride, and nickel-chrome nitride.

5. The substrate of claim 1 wherein at least one of the first and second dielectric absorber films comprises titanium nitride and/or niobium nitride.

6. The substrate of claim 1 wherein the first and second dielectric absorber films each have an optical thickness of less than 600 Å

.

7. The substrate of claim 1 wherein the coated substrate has a monolithic visible transmittance of less than 0.60.

8. The substrate of claim 7 wherein the monolithic visible transmittance is between 0.30 and 0.50.

9. The substrate of claim 1 wherein the coated substrate has a monolithic transmitted color characterized by the following color coordinates:

0.2<

x<

0.35, and 0.2<

y<

0.35, under 1931 CIE color standard.

10. The substrate of claim 1 wherein the transparent substrate is a glass pane that is part of a multiple-pane insulating glazing unit.

32. The substrate of claim 1 wherein said transparent dielectric film has an extinction coefficient (k) at 550 nm of less than 0.1.

11. A transparent substrate bearing a solar control low-emissivity coating, the coating being a double-type low-emissivity coating comprising:

a first infrared-reflective film comprising silver and a second infrared-reflective film comprising silver, the first infrared-reflective film being closer to the substrate than the second infrared-reflective film;

a middle coat between the first and second infrared-reflective films, wherein the middle coat does not include any dielectric absorber film but rather consists essentially of transparent dielectric film;

a first dielectric absorber film between the substrate and the first infrared-reflective film, the first dielectric absorber film having a coefficient of extinction (k) at 550 nm of greater than 0.4; and

a second dielectric absorber film further from the substrate than the second infrared-reflective film, the second dielectric absorber film having a coefficient of extinction (k) at 550 nm of greater than 0.4,

wherein the first and second dielectric absorber films both have a neutral absorption ratio of k<sub>380<

λ

<

450 nm</sub>/k<sub>650<

λ

<

760 nm</sub> between 0.52 and 1.9.

12. The substrate of claim 11 wherein the first and second dielectric absorber films both comprise nitride film.

13. The substrate of claim 11 wherein at least one of the first and second dielectric absorber films comprises a compound nitride including silicon nitride mixed with another nitride.

14. The substrate of claim 11 wherein both of the first and second dielectric absorber films comprise a compound nitride including silicon nitride mixed with at least one other nitride selected from the group consisting of titanium nitride, niobium nitride, zirconium nitride, chromium nitride, and nickel-chrome nitride.

15. The substrate of claim 11 wherein at least one of the first and second dielectric absorber films comprises titanium nitride and/or niobium nitride.

16. The substrate of claim 11 wherein the first and second dielectric absorber films each have an optical thickness of less than 600 Å

.

17. The substrate of claim 11 wherein the coated substrate has a monolithic visible transmittance of between 0.30 and 0.50.

18. The substrate of claim 11 wherein the coated substrate has a monolithic transmitted color characterized by the following color coordinates:

0.2<

x<

0.35, and 0.2<

y<

0.35, under 1931 CIE color standard.

19. The substrate of claim 11 wherein a first suboxide barrier layer is directly over the first infrared-reflective film, and a second suboxide barrier layer is directly over the second infrared-reflective film, and wherein innermost portions of the first and second suboxide barrier layers are defined by suboxide film rather than metal film.

20. The substrate of claim 19 wherein the first and second suboxide barrier layers are directly beneath respective transparent dielectric layers.

21. The substrate of claim 11 wherein a titanium suboxide layer is directly over the second infrared-reflective layer, the second dielectric absorber film being directly over the titanium suboxide layer.

33. The substrate of claim 11 wherein said transparent dielectric film has an extinction coefficient (k) at 550 nm of less than 0.1.

22. A transparent substrate bearing a solar control low-emissivity coating, the coating being a triple-type low-emissivity coating comprising, in sequence outwardly:

a first absorber film comprising nitride, the first absorber film having a coefficient of extinction (k) at 550 nm of greater than 0.4;

a first infrared-reflective film comprising silver;

a first spacer coat, wherein the first spacer coat does not include any dielectric absorber film but rather consists essentially of transparent dielectric film;

a second infrared-reflective film comprising silver;

a second spacer coat, wherein the second spacer coat does not include any dielectric absorber film but rather consists essentially of transparent dielectric film;

a third infrared-reflective film comprising silver; and

a second absorber film comprising nitride, the second absorber film having a coefficient of extinction (k) at 550 nm of greater than 0.4;

wherein the first and second absorber films both have a neutral absorption ratio of k<sub>380<

λ

<

450 nm</sub>/k<sub>650<

λ

<

760 nm</sub> between 0.52 and 1.9.

23. The substrate of claim 22 wherein at least one of the first and second absorber films comprises a compound nitride including silicon nitride mixed with another nitride.

24. The substrate of claim 22 wherein both of the first and second absorber films comprise a compound nitride including silicon nitride mixed with at least one other nitride selected from the group consisting of titanium nitride, niobium nitride, zirconium nitride, chromium nitride, and nickel-chrome nitride.

25. The substrate of claim 22 wherein the first and second nitride absorber films both comprise titanium nitride and/or niobium nitride.

26. The substrate of claim 22 wherein first, second, and third suboxide barrier layers are directly over the first, second, and third infrared-reflective layers, respectively, and wherein innermost portions of the three suboxide barrier layers are formed by suboxide film rather than metal film.

27. The substrate of claim 26 wherein the three suboxide barrier layers are directly beneath respective transparent dielectric layers.

28. The substrate of claim 22 wherein a titanium suboxide layer is directly over the third infrared-reflective layer, the second nitride absorber film being directly over the titanium suboxide layer.

29. The substrate of claim 22 wherein the coated substrate has a monolithic visible transmittance of between 0.30 and 0.50.

30. The substrate of claim 22 wherein the coated substrate has a monolithic transmitted color characterized by the following color coordinates:

0.2<

x<

0.35, and 0.2<

y<

0.35, under 1931 CIE color standard.

31. The substrate of claim 30 wherein the monolithic transmitted color is characterized by the following color coordinates:

0.25<

x<

0.33, and 0.25<

y <

0.33, under 1931 CIE color standard.

34. The substrate of claim 22 wherein said transparent dielectric film has an extinction coefficient (k) at 550 nm of less than 0.1.