Neutral, high performance, durable low-E glass coating system and insulating glass units made therefrom

• US 5,800,933 A
• Filed: 12/27/1996
• Issued: 09/01/1998
• Est. Priority Date: 11/02/1995
• Status: Expired due to Term

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Lingle, Philip J., Larson, Steven L., Hartig, Klaus W.
• Primary Examiner(s): Zimmerman, John J.
• Application Number:
  US08/774,929
• Time in Patent Office: 613 Days
• Field of Search: 428/622, 428/623, 428/627, 428/630, 428/632, 428/666, 428/673, 428/680, 428/34, 428/46, 52/786.1
• US Class Current: 428/622
• 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: E06B 3/66304 Discrete spacing elements, e.g. for evacuated glazing units
• CPC Class Codes: Y10T 428/12542 More than one such component
• CPC Class Codes: Y10T 428/12549 Adjacent to each other
• CPC Class Codes: Y10T 428/12576 Boride, carbide or nitride component
• CPC Class Codes: Y10T 428/12597 Noncrystalline silica or noncrystalline plural-oxide component [e.g., glass, etc.]
• CPC Class Codes: Y10T 428/12611 Oxide-containing component
• CPC Class Codes: Y10T 428/12896 Ag-base component

Abstract

A low-E sputter-coated layer system for automotive and architectural purposes of the basic Si₃ N₄ /NiCr/Ag/NiCr/Si₃ N₄ type improved by either an undercoat of TiO₂ or the use of stainless steel in the Si₃ N₄ layers, or both. By selection of appropriate thicknesses the layer coatings may be rendered heat treatable. I.G. units are an advantage product in which the coatings may be employed.

Claims

1. In a sputter-coated glass article comprised of a glass substrate having on a surface thereof, from the glass outwardly, a layer system including:

a first layer of Si₃ N₄ ;

a first layer of nickel or nichrome;

a layer of silver;

a second layer of nickel or nichrome; and

a second layer of Si₃ N₄ ;

wherein at least one of said Si₃ N₄ layers includes from about 0.5%-15% by weight stainless steel, and wherein when said glass substrate has a thickness of about 2 mm-6 mm, said coated glass substrate has a normal emissivity (E_n) of about 0.06 or less, a hemispherical emissivity (E_h) of about 0.08 or less, a sheet resistance (R_s) of about 7.0 ohms/_sq. or less and having a substantially neutral visible reflected color when viewed from the glass side.

2. A sputter-coated glass article according to claim 1, wherein said coated glass substrate has a visible transmittance of at least about 70%.

3. A sputter-coated glass article according to claim 1, wherein both of said first and second layers of Si₃ N₄ include stainless steel in an amount of from about 0.5%-15% by weight.

4. A sputter-coated glass article according to claim 3, wherein said layer system includes an undercoat layer of TiO₂.

5. A sputter-coated glass article according to claims 3, or 4, wherein said article is heat treatable.

6. A sputter-coated glass article according to claims 3, or 4, wherein said article is chemically and mechanically durable.

7. A sputter-coated glass article according to claim 1, wherein said layer system includes the following layers and approximate thicknesses, from the glass outwardly:

space="preserve" listing-type="tabular">______________________________________ Layer thickness Å

______________________________________ Si.sub.3 N.sub.4 20-600 NiCr 7-100 Ag 75-250 NiCr 7-50 Si.sub.3 N.sub.4 50-600 ______________________________________

8. A sputter-coated glass article according to claim 7, wherein said layer system includes an undercoat layer of TiO₂ in a thickness of about 100 Å

to 400 Å

.

9. A sputter-coated glass article according to claim 7, wherein each of said layers of Si₃ N₄ includes about 0.5%-15% by weight of stainless steel.

10. A sputter-coated glass article according to claim 9, wherein said layer system further includes an undercoat layer of TiO₂ in a thickness of about 100 Å

to 400 Å

.

11. A sputter-coated glass article according to claim 7, wherein said NiCr layers are substantially free of chromium nitride and said layer system is temperable.

12. A sputter-coated glass article according to claim 7, wherein said glass substrate has a normal emissivity (E_n) of about 0.05 or less, a hemispherical emissivity (E_h) of about 0.06 or less, and a sheet resistance (R_s) of about 5.0 ohms/_sq. or less.

13. A sputter-coated, heat treatable, glass article comprised of a glass substrate having on a planar surface thereof, from the glass outwardly, a layer system including:

a first layer of Si₃ N₄ ;

a first layer of nickel or nichrome;

a layer of silver;

a second layer of nickel or nichrome; and

a second layer of Si₃ N₄ ;

wherein at least one of said layers of Si₃ N₄ further includes stainless steel in an amount of about 0.5%-15% by weight of said layer.

14. A sputter-coated, heat treatable, glass article according to claim 13, wherein said thicknesses of said layers are:

said first layer of Si₃ N₄, about 200 Å

to 600 Å

;

said first layer of nickel or nichrome, about 7 Å

to 100 Å

;

said layer of silver, about 115 Å

to 190 Å

;

said second layer of nickel or nichrome, about 7 Å

to 50 Å

; and

said second layer of Si₃ N₄, about 50 Å

to 600 Å

.

15. A sputter-coated, heat treatable, glass article according to claim 14, wherein said article has a visible transmittance of at least about 70%, an E_n of less than about 0.06, and E_h of less than about 0.07, and wherein said layer system is mechanically and chemically durable and has a substantially neutral visible reflected color when viewed from the glass side.

16. A sputter-coated glass article according to claim 13, wherein said layer system further includes an undercoat layer of TiO₂ having a thickness of about 100 Å

to 400 Å

.

17. A sputter-coated glass article comprised of a glass substrate having on a surface thereof, from the glass outwardly, a layer system consisting essentially of and having about the following thicknesses:

space="preserve" listing-type="tabular">______________________________________ Layer thickness Å

______________________________________ Si.sub.3 N.sub.4 400-500 NiCr 7-30 Ag 140-170 NiCr 7-15 Si.sub.3 N.sub.4 400-600 ______________________________________

and wherein said layers of Si₃ N₄ include stainless steel in an amount of 0.5%-15% by weight of each said layer.

18. A sputter-coated glass article according to claim 17, wherein said article is heat treatable.

19. A sputter-coated article according to claim 18, wherein said stainless steel in layers (a) and (e) is in an amount of about 6% by weight of each said layer.

20. A sputter-coated article according to claim 19, wherein said layers (b) and (d) are comprised of chromium nitride and said stainless steel is comprised of chromium nitride.

21. A sputter-coated article according to claim 20, wherein said stainless steel is No. 316 stainless steel.

22. A sputter-coated article according to claim 17, wherein said glass substrate having said layer system on one of the surfaces thereof has the following characteristics:

space="preserve" listing-type="tabular">______________________________________ GLASS SIDE R.sub.G Y is about 8 to 18 a.sub.h is about -3 to +3 b.sub.h is about 0 to -15 FILM SIDE R.sub.f Y is about 4 to 15 a.sub.h is about 0 to +8 b.sub.h is about -5 to -20 ______________________________________

wherein RY is the reflectance and a_h and b_h are the color coordinates as measured in Hunter units, Ill. C, 10°

observer.

23. A sputter-coated article according to claim 22, wherein the glass side and film side characteristics are:

space="preserve" listing-type="tabular">______________________________________ GLASS SIDE R.sub.G Y is about 9 to 15 a.sub.h is about -1 to +3 b.sub.h is about -2 to -10 FILM SIDE R.sub.f Y is about 4 to 10 a.sub.h is about +3 to +7 b.sub.h is about -10 to -20. ______________________________________

24. A sputter-coated article according to claim 17, wherein said visible transmittance of said coated glass substrate is about 74%-76%.

25. An insulating glass unit comprised of at least two substantially parallel, spaced sheets of glass wherein at least one sheet of glass is a sputter-coated sheet of glass according to claim 17.

26. An insulating glass unit according to claim 25, wherein said two sheets of glass are sealed together at their peripheral edges thereby to define an insulating chamber therebetween, and wherein said layer system is located on a surface of one of said glass sheets within said insulating chamber, and the reflectance and color characteristics when viewed from outside are:

R_G Y about 14 to 20

a_h about -2 to +2

b_h about 0 to -10

and when viewed from the in side are;

R_f Y about 11 to 18

a_h about 0 to +4

b_h is about 0 to -10

and the visible transmittance is at least about 61%.

27. An insulating glass unit according to claim 26, wherein said unit is an insulating glass window, door or wall and the visible transmittance is at least about 63% and said layer system is heat treatable.