High performance, durable, low-E glass

• US 5,344,718 A
• Filed: 04/30/1992
• Issued: 09/06/1994
• Est. Priority Date: 04/30/1992
• 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., Hartig, Klaus W.
• Primary Examiner(s): Fuller, Benjamin R.
• Assistant Examiner(s): LUND, VALERIE A
• Application Number:
  US07/876,350
• Time in Patent Office: 859 Days
• Field of Search: 428/614, 428/627, 428/630, 428/631, 428/668, 428/622, 428/623, 428/630, 428/627, 359/360
• US Class Current: 428/623
• 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 17/3639 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: C03C 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: C23C 14/0652 Silicon nitride
• CPC Class Codes: C23C 14/0688 Cermets, e.g. mixtures of metal and one or more of carbides, nitrides, oxides or borides
• CPC Class Codes: C23C 14/185 by cathodic sputtering
• CPC Class Codes: G02B 5/282 reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection
• 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.]

Abstract

A high performance, durable, low-E glass exhibiting about 80% or more visible transmittance, a hemispherical emissivity (E_h) of about 0.13 or less, and a normal emissivity (E_n) of about 0.10 or less is formed by sputter-coating a layer system on the glass substrate which comprises an undercoat and overcoat of Si₃ N₄, at least one silver layer, and at least two sandwiching layers of a nickel or nickel alloy, preferably with the nickel alloy being nichrome, and the chromium being in the form of a nitride thereof.

Claims

1. A sputter-coated glass article comprising a glass substrate having thereon from the glass outwardly, a layer system comprising:

(a) an undercoat layer of Si₃ N₄,

(b) a layer of nickel or nichrome,

(c) a layer of silver,

(d) a layer of nickel or nichrome, and

(e) an overcoat layer of Si₃ N₄ ;

and, when said glass substrate has a thickness of about 2 mm-6 mm, said coated glass has a visible transmittance of at least about 78%, a normal emissivity (E_n) of less than about 0.12 and a hemispherical emissivity (E_h) of less than about 0.16.

2. A sputter-coated glass article according to claim 1 wherein said layer system consists essentially of five layers.

3. A sputter-coated glass article according to claim 1 wherein said layer system specifically consists essentially of, from the glass outwardly,

(a) a layer of Si₃ N₄,

(b) a layer of nichrome,

(c) a layer of silver,

(d) a layer of nichrome,

(e) a layer of silver,

(f) a layer of nichrome, and

(g) a layer of Si₃ N₄.

4. A sputter-coated glass article according to claim 3 wherein each said silver layer is about 50 Å

thick and each said nichrome layer is less than about 7 Å

thick.

5. A sputter-coated glass article according to claim 1 wherein each said nickel or nichrome layer has a thickness less than about 7 Å

and wherein there is only one silver layer and said silver layer is greater than about 90 Å

thick.

6. A sputter-coated glass article according to claim 5 wherein said silver layer is about 90-105 Å

thick.

7. A sputter-coated glass article according to claim 5 wherein said undercoat of Si₃ N₄ is at least about 400 Å

thick and said overcoat Si₃ N₄ layer is at least about 540 Å

thick.

8. A sputter-coated glass article according to claim 1 wherein said layer system is durable and said visible transmittance is about 78% to about 80%.

9. A sputter-coated glass article according to claim 8 wherein said E_n is about 0.10 or less and said E_h is about 0.13 or less.

10. A sputter-coated glass article according to claim 9 wherein said E_n is about 0.09-0.10 and said E_h is about 0.12-0.13.

11. A sputter-coated glass article according to claim 8 which has a sheet resistance of about 10.5 ohms/_sq. or less.

12. A sputter-coated glass article according to claim 11 wherein said sheet resistance is about 9-10 ohms/_sq..

13. A sputter-coated glass article comprising a glass substrate having thereon from the glass outwardly, a layer system comprising:

(a) an undercoat layer of Si₃ N₄,

(b) a nichrome based layer selected from the group consisting of nichrome and nitrided nichrome,

(c) a layer of silver,

(d) a nichrome based layer selected from the group consisting of nichrome and nitrided nichrome, and

(e) an overcoat layer of Si₃ N₄,

at least one said nichrome based layer being nitrided nichrome, and when said glass substrate has a thickness of about 2 mm-6 mm, said coated glass has a visible transmittance of at least about 78%, a normal emissivity (E_n) of less than about 0.12 and a hemispherical emissivity (E_h) of less than about 0.16.

14. A sputter-coated glass article according to claim 13 wherein each said nichrome based layer is said nitrided nichrome.

15. A sputter-coated glass article according to claim 13 wherein said nichrome is about 80% nickel and about 20% chromium by weight.

16. A sputter-coated glass article according to claim 15 wherein said transmittance is about 78% to about 80%, said E_n is about 0.10 or less and said E_h is about 0.13 or less.

17. A sputter-coated glass article according to claim 16 wherein said coated glass has a sheet resistance of about 10.5 ohms/_sq. or less.

18. A sputter-coated glass article according to claim 17 wherein a thickness of any said nichrome based layer is less than about 7 Å

thick and a total thickness of said silver is about 90-105 Å

thick.

19. A sputter-coated glass article according to claim 18 wherein there is only one silver layer about 95 Å

thick.

20. A sputter-coated glass article comprising a glass substrate having thereon, from the glass outwardly, a layer system comprising:

(a) an undercoat layer of Si₃ N₄,

(b) a nichrome based layer selected from the group consisting of nichrome and nitrided nichrome,

(c) a layer of silver

(d) a nichrome based layer selected from the group consisting of nichrome and nitrided nichrome,

(e) a layer of silver,

(f) a nichrome based layer selected from the group consisting of nichrome and nitrided nichrome, and

(g) an overcoat layer of Si₃ N₄,

each said silver layer being about 50 Å

thick and at least one said nichrome based layer being nitrided nichrome, and when said glass substrate has a thickness of about 2 mm-6 mm, said coated glass has a visible transmittance greater than about 76%, a normal emissivity (E_n) of less than about 0.12 and a hemispherical emissivity (E_h) of less than about 0.16.

21. A sputter-coated glass article according to claim 20 wherein each said nichrome based layer is said nitrided nichrome and has a thickness of less than about 7 Å

, a total thickness of each of said silver layer combined is about 90-105 Å

, the coated glass has a sheet resistance of about 10.5 ohms/sq. or less, said nichrome is 80% nickel and 20% chromium by weight, said transmittance is about 78%-80%, said E_n is about 0.10 or less and said E_h is about 0.13 or less.