Highly tetrahedral amorphous carbon coating on glass

• US 20010014398A1
• Filed: 03/15/2001
• Published: 08/16/2001
• Est. Priority Date: 05/03/1999
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Veerasamy, Vijayen S.
• Granted Patent: US 6,303,226 B2
• Time in Patent Office: Days
• US Class Current: 428/408
• CPC Class Codes: B05D 5/083 involving the use of fluoropolymers
• CPC Class Codes: B08B 17/06 by giving articles subject to fouling a special shape or arrangement
• CPC Class Codes: B08B 17/065 the surface having a microscopic surface pattern to achieve the same effect as a lotus flower
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: B32B 17/1033 Laminated safety glass or glazing containing temporary protective coatings or layers
• CPC Class Codes: B60S 1/54 using gas, e.g. hot air
• CPC Class Codes: B60S 1/58 for rear windows
• CPC Class Codes: C03C 17/22 with other inorganic material C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 17/3441 comprising carbon, a carbide or oxycarbide
• CPC Class Codes: C03C 17/347 comprising a sulfide or oxysulfide
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3634 one layer at least containing carbon, a carbide or oxycarbide
• 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 17/42 at least one coating of an organic material and at least one non-metal coating
• CPC Class Codes: C03C 2217/282 Carbides, silicides
• CPC Class Codes: C03C 2217/76 Hydrophobic and oleophobic coatings
• CPC Class Codes: C03C 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: C03C 2218/112 : by spraying
• CPC Class Codes: C03C 2218/151 : by vacuum evaporation
• CPC Class Codes: C03C 2218/31 : Pre-treatment
• CPC Class Codes: C03C 23/0075 : Cleaning of glass specially adapted to plate glass B08B11/00
• CPC Class Codes: C03C 3/076 : with 40% to 90% silica, by weight C03C3/045 takes precedence
• CPC Class Codes: C23C 16/26 : Deposition of carbon only
• CPC Class Codes: C23C 26/00 : Coating not provided for in groups C23C2/00 - C23C24/00
• CPC Class Codes: Y10T 428/265 : 1 mil or less
• CPC Class Codes: Y10T 428/268 : Monolayer with structurally defined element
• CPC Class Codes: Y10T 428/30 : Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

A soda inclusive glass substrate is coated with a highly tetrahedral amorphous carbon inclusive layer that is a form of diamond-like carbon (DLC). In certain embodiments, the amorphous carbon layer includes at least about 35% sp³ carbon-carbon bonds, more preferably at least about 70%, and most preferably at least about 80% of the sp³ carbon-carbon bonds. The high density (e.g. greater than or equal to about 2.4 gm/cm³) of the amorphous carbon layer prevents soda from exiting the glass and reacting with water at surface(s) of the glass, thereby minimizing visible stains (or corrosion) on the glass. The high density amorphous carbon layer also may repel water. In some embodiments, the highly tetrahedral amorphous carbon layer is part of a larger DLC coating, while in other embodiments the highly tetrahedral layer forms the entirety of a DLC coating on the substrate.

Claims

1. A coated glass comprising:

a soda inclusive glass substrate comprising, on a weight basis;

SiO₂ from about 60-80%,

Na₂O from about 10-20%,

CaO from about 0-16%,

K₂O from about 0-10%,

MgO from about 0-10%,

Al₂O₃ from about 0-5%; and

a non-crystalline diamond-like carbon (DLC) coating provided on said glass substrate, wherein said DLC coating includes at least a first highly tetrahedral amorphous carbon layer having at least about 35% sp³ carbon-carbon bonds and an average density of at least about 2.4 gm/cm³.

2. The coated glass of

claim 1

, wherein said DLC coating further includes a second layer therein of amorphous carbon that is in direct contact with said substrate so that said second layer is disposed between said substrate and said first highly tetrahedral amorphous carbon layer, and wherein said first highly tetrahedral amorphous carbon layer has a greater density and a greater percentage of sp³ carbon-carbon bonds than said second layer of amorphous carbon.

3. The coated glass of

claim 1

, wherein said first highly tetrahedral amorphous carbon layer has at least about 70% sp³ carbon-carbon bonds, and wherein said glass substrate is a soda lime silica glass substrate including from about 66-75% SiO₂, from about 10-20% Na₂O, from about 5-15% CaO, from about 0-5% MgO, from about 0-5% Al₂O₃, and from about 0-5% K₂O.

4. The coated glass of

claim 3

, wherein said highly tetrahedral amorphous carbon layer has at least about 80% sp³ carbon-carbon bonds.

5. The coated glass of

claim 3

, wherein said DLC coating has an average hardness of at least about 40 Gpa, and an average density of at least about 2.4 gm/cm³.

6. The coated glass of

claim 1

, wherein said DLC coating has a thickness of from about 30 to 3,000 Å

.

7. The coated glass of

claim 6

, wherein said DLC coating has a thickness of from about 50 to 300 Å

.

8. The coated glass of

claim 1

, wherein said DLC coating has a bandgap of from about 1.8 to 2.2 eV.

9. The coated glass of

claim 1

, wherein the coated glass comprises the following characteristics:

visible transmittance (Ill. A);

>

60% UV transmittance;

<

38% IR transmittance;

<

35%.

10. The coated glass of

claim 1

, wherein said DLC coating includes at least about 70% sp³ carbon-carbon bonds.

11. The coated glass of

claim 1

, wherein said DLC coating includes at least about 80% sp³ carbon-carbon bonds.

12. The coated glass of

claim 1

, wherein said DLC coating is from about 30 to 3,000 Å

thick, and wherein said first highly tetrahedral amorphous carbon layer of said DLC coating is from about 30 to 2,900 Å

thick.

13. The coated glass of

claim 1

, wherein said DLC coating includes sp³ carbon-carbon bonds subimplanted in a surface of said glass substrate so as to strongly bond said DLC coating to said glass substrate.

14. The coated glass of

claim 1

, further comprising a low-E coating system having at least one layer provided between said glass substrate and said DLC layer.

15. A coated glass comprising:

a glass substrate including at least about 5% by weight Na₂O;

a highly tetrahedral amorphous carbon layer, for reducing corrosion on the substrate, having a density of at least about 2.4 gm/cm³ provided on said glass substrate in order to reduce corrosion or stains on the coated glass, wherein said highly tetrahedral amorphous carbon layer includes sp² and sp³ carbon-carbon bonds; and

wherein said highly tetrahedral amorphous carbon layer has more sp³ carbon-carbon bonds than sp² carbon-carbon bonds.

16. The coated glass of

claim 15

, further comprising another amorphous carbon layer located between said substrate and said highly tetrahedral amorphous carbon layer, and wherein said another amorphous carbon layer has a density less than said highly tetrahedral amorphous carbon layer and a lesser percentage of sp³ carbon-carbon bonds than said highly tetrahedral amorphous carbon layer.

17. The coated glass of

claim 15

, wherein said highly tetrahedral amorphous carbon layer has at least about 70% sp³ carbon-carbon bonds, and a thickness of from about 30-300 Å

.

18. The coated glass of

claim 17

, wherein said highly tetrahedral amorphous carbon layer is in direct contact with said glass substrate.

19. A coated glass comprising:

a soda inclusive glass substrate comprising, on a weight basis;

SiO₂ from about 60-80%,

Na₂O from about 10-20%,

CaO from about 0-16%,

K₂O from about 0-10%,

MgO from about 0-10%,

Al₂O₃ from about 0-5%;

a diamond-like carbon (DLC) coating provided on said glass substrate for reducing visible corrosion, wherein said DLC coating has an average density of at least about 2.4 gm/cm³ and a thickness of from about 50 to 300 Å

; and

wherein the coated glass comprises the following characteristics;

visible transmittance;

>

60%

UV transmittance;

<

38%

IR transmittance;

<

35%.

20. A method of making a coated glass article, the method comprising the steps of:

providing a glass substrate comprising, on a weight basis, 60-80% SiO₂, 10-20% Na₂O, 0-16% CaO, 0-10% K₂O, 0-10% MgO, and 0-5% Al₂O₃; and

forming at least one highly tetrahedral amorphous carbon layer having more sp³ carbon-carbon bonds than sp² carbon-carbon bonds on the glass substrate for reducing potential for corrosion.

21. The method of

claim 20

, wherein said forming step includes using a plasma ion beam and using acetylene gas to form the at least one carbon layer on the glass substrate.

22. The method of

claim 20

, wherein said forming step includes using a plasma ion beam to form the highly tetrahedral amorphous carbon layer, and varying the ion energy from about 200 to 800 eV during the deposition of an interfacial portion of the amorphous carbon layer deposited immediately adjacent the substrate to a lower level of from about 100 to 150 eV during the deposition of a higher density portion of the carbon layer that is deposited over the interfacial portion.

23. An automotive window comprising:

a substrate transparent to at least about 70% of visible light rays;

a highly tetrahedral amorphous carbon inclusive coating provided on said substrate, wherein said coating has a thickness of from about 50 to 300 Å and

a substantial number of sp³ carbon-carbon bonds; and

wherein the automotive window comprises the following optical characteristics;

visible transmittance;

>

70%

UV transmittance;

<

38%

IR transmittance;

<

35%.

24. The automotive window of

claim 23

, wherein said substrate includes one of soda lime silica glass, borosilicate glass, and substantially transparent plastic, and wherein said coating has an average density of at least about 2.4 gm/cm³.

25. The automotive window of

claim 23

, wherein the window is an automotive windshield.

26. A method of coating a glass substrate to improve long-term strength of the glass substrate, the method comprising the steps of:

providing a glass substrate having at least one crack with a tip defined therein;

depositing a layer of diamond-like carbon directly on the glass substrate at an energy level so that carbon atoms make their way into the crack to a location proximate the tip of the crack; and

the carbon atoms in the crack preventing some water molecules from reaching a silicon-oxygen bond at the tip of the crack thereby improving the long-term strength of the glass.

27. The method of

claim 26

, wherein said energy level is an ion energy level of from about 200 to 1,000 eV.