Matchable low-E I.G. units and laminates and methods of making same

• US 20030101749A1
• Filed: 09/19/2002
• Published: 06/05/2003
• Est. Priority Date: 12/06/1999
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Larson, Steven L., Lingle, Philip J., Stachowiak, Grzegorz
• Granted Patent: US 6,782,718 B2
• Time in Patent Office: Days
• US Class Current: 65/60.2
• 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 17/3618 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 17/3644 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 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: Y10T 428/12542 More than one such component
• CPC Class Codes: Y10T 428/12576 Boride, carbide or nitride component
• CPC Class Codes: Y10T 428/12896 Ag-base component
• CPC Class Codes: Y10T 428/12944 Ni-base component
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A neutral blue-green heat treatable and matchable glass laminate or I.G. unit employs a layer system whose visible transmittance increases by at least 4% during heat treatment and whose ΔE*_ab is less than about 3.0 and Δa* is less than about 0.7. The sputter coated layer system includes a silver layer sandwiched between nichrome layers and thereafter layers of Si₃N₄.

Claims

1. In a glass article having at least two glass substrates in light transmitting communication with each other and having a sputter coated heat treatable layer system on at least one of said substrates, which coated substrate is heat treated, the improvement comprising said glass article being matchable and wherein said sputter coated layer system comprises from the glass substrate on which it is coated, outwardly:

a) a layer of silicon nitride;

b) a substantially metallic layer of nickel or nickel alloy having a nickel content of at least about 10% by weight Ni, said layer being substantially free of a nitride or oxide of said metal;

c) a substantially metallic layer of silver;

d) a substantially metallic layer of nickel or a nickel alloy having a nickel content of at least about 10% by weight Ni, said layer being substantially free of a nitride or oxide of said metal; and

e) a layer of silicon nitride;

wherein said heat treated layer coating system has a visible transmittance at least 4% greater than before it was heat treated; and

wherein the relative thicknesses of said layers combine to result in said heat treated coated substrate which when viewed monolithically from the glass side of said coating has a Δ

E*_ab less than 5.0 and a Δ

a* less than about 0.8.

2. A glass article according to claim 1 wherein said glass article is an insulating glass unit comprised of two panes of glass in substantially spaced parallel position one with respect to the other to define an insulating space therebetween, and wherein said layer coating system is located on a surface of one of said panes of glass within said insulating space.

3. A glass article according to claim 1 wherein said glass article is a glass laminate comprised of at least two sheets of glass sealed together and having therebetween said layer coating system.

4. A glass article according to claim 1 wherein the thicknesses of the layers are within the following range:

5. A glass article according to claim 1 wherein said layer system consists essentially of said five layers and wherein a* and b* of said coated heat treated substrate are both negative.

6. A glass article according to claim 5 wherein said coated heat treated substrate has a color wherein a* is from about −

2.3 to −

6.3 and b* is from about −

4.5 to −

10.5.

7. A glass article according to claim 5 having a generally neutral, blue-green color and wherein said coated heat treated substrate has a color wherein a* is from about −

3.3 to −

5.3 and b* is from about −

6.4 to −

9.0.

8. A glass article according to claim 1 or 7 wherein said heat treated coated glass substrate when viewed monolithically from the glass side of said coating has a Δ

E*_ab of less than 4.0 and a Δ

a* of less than 0.5.

9. A glass article according to claim 1 wherein said coated heat treated glass substrate is comprised of a clear glass substrate.

10. A glass article according to claim 1 wherein said coated heat treated glass substrate is a tempered glass substrate having a visible transmittance after tempering which is 5-7% greater than before tempering.

11. A glass article according to claim 1 or 10 wherein said glass article is an insulating glass unit and has a Δ

E*_ab no greater than 3.0 and a Δ

a* less than 0.7 when viewed from a glass side.

12. A glass article according to claim 1 wherein said thicknesses of said layers are:

13. A glass article according to claim 12 wherein said substantially metallic layers consist essentially of Ni, Fe, and Cr.

14. A glass article according to claim 1 wherein said article is an insulating glass unit having an insulation space between said coated heat treated glass substrate and an uncoated glass substrate, wherein said glass of said substrates is clear glass and wherein said heat treated coated glass substrate monolithically has the following characteristics before and after heat treatment when measured at a glass thickness of 6 mm:

15. A glass article according to claim 14 wherein said heat treated coated glass substrate monolithically has the following characteristics before and after heat treatment when measured at a glass thickness of 6 mm:

16. A glass article according to claim 14 wherein said insulating glass unit has the following characteristics when measured at a glass substrate thickness of 6 mm:

17. A glass article according to claim 16 wherein said heat treated coated glass substrate is tempered.

18. A glass article according to claim 1 wherein the Δ

a* of said coated glass substrate is substantially zero.

33. A glass article according to claim 1, 4 or 12 wherein said layer coating system so formed is mechanically and chemically durable both before and after said heat treatment.

19. In the method of making a matchable glass article having at least two glass substrates in light transmitting communication with each other and having a heat treatable sputter coated layer system on at least one surface of a said substrate which coated substrate is heat treated, the improvement comprising the steps of:

a) sequentially sputter coating onto a surface of at least one of said glass substrates a said heat treatable layer system which comprises from the glass substrate on which it is coated outwardly;

a first layer of silicon nitride;

a second substantially metallic layer of nickel or nickel alloy having a nickel content of at least about 10% by weight Ni, said layer being substantially free of a nitride or oxide of said metal;

a third substantially metallic layer of silver;

a fourth substantially metallic layer of nickel or a nickel alloy having a nickel content of at least about 10% by weight Ni, said layer being substantially free of a nitride or an oxide of said metal; and

a fifth layer of silicon nitride;

wherein the relative thicknesses of said layers combine to result in said article when viewed from a glass side having a Δ

E*_ab no greater than 3.0 and a Δ

a* less than 0.7;

b) subjecting said substrate having said coating thereon to a heat treatment which increases the visible transmittance of said coated substrate by at least 4%; and

c) thereafter fabricating said glass substrates so as to be in light transmitting communication with each other thereby to form said matchable glass article.

20. The method according to claim 19 wherein said heat treatment is selected from tempering, bending and heat strengthening.

21. The method according to claim 19 wherein said glass article is an insulating glass unit comprised of two panes of glass one of said panes having said coating thereon and said fabrication step includes retaining said panes in substantially parallel relationship with each other thereby to define an insulating space therebetween and wherein said layer coating system is located on a surface of said coated pane which is located within said insulating space.

22. The method according to claim 19 wherein said article is a glass laminate comprised of at least two glass sheets, one of which has said heat treatable sputter coated layer system thereon, and said fabrication step includes laminating said coated glass sheet after it is heat treated to another glass sheet such that the said coating layer is located between said glass sheets.

23. The method according to claim 19 wherein the thicknesses of the layers are within the following range:

24. The method according to claim 19 wherein said heat treatment is tempering.

25. The method according to claim 19 wherein said heat treatment increases said visible transmittance by 5%-7%.

26. The method according to claim 19 wherein said glass article has a generally neutral blue-green color and when viewed from the glass side of said coating has a Δ

E*_ab of less than 2.0 and a Δ

a* of less than 0.5.

27. The method according to claim 19 wherein said heat treatable coated glass substrate, monolithically when measured at a glass thickness of 6 mm has a Δ

E*_ab less than 5.0 and a Δ

a* less than 0.8.

28. The method according to claim 27 wherein said monolithic Δ

E*_ab is less than 4.0 and a Δ

a* is less than 0.5.

29. The method according to claim 28 wherein said monolithic Δ

a* is substantially zero.

30. The method of claim 19 wherein said article is an insulating glass unit whose U-values and shading coefficients are substantially the same as those of an otherwise identically formed I.G. unit whose coated substrate is not heat treated.

31. The method according to claim 30 wherein said U-values and shading coefficients are:

32. The method according to claim 19 wherein said layer coating system so formed is mechanically and chemically durable both before and after said heat treatment.