Coatings on glass

• US 5,749,931 A
• Filed: 06/07/1995
• Issued: 05/12/1998
• Est. Priority Date: 07/08/1993
• Status: Expired due to Fees

• Current Assignee: Libbey-Owens-Ford Co. (Eaton Corporation PLC.), Pilkington PLC
• Original Assignee: Libbey-Owens-Ford Co. (Eaton Corporation PLC.), Pilkington PLC
• Inventors: Soubeyrand, Michel J., Goodman, Ronald D., Jenkinson, Timothy
• Primary Examiner(s): Czaja, Donald E.
• Assistant Examiner(s): Ruller, Jacqueline A.
• Application Number:
  US08/471,909
• Time in Patent Office: 1,070 Days
• Field of Search: 427/165, 427/166, 427/167, 65/60.1, 65/60.2, 65/60.5, 65/95, 65/97, 65/98
• US Class Current: 65/60.1
• CPC Class Codes: B60R 1/08 involving special optical features, e.g. avoiding blind spots , e.g. convex mirrors; Side-by-side associations of rear-view and other mirrors B60R1/025, B60R1/10 take precedence
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3482 comprising silicon, hydrogenated silicon or a silicide
• CPC Class Codes: G02B 5/0833 comprising inorganic materials only

Abstract

A method of producing mirrors comprising depositing onto a ribbon of hot glass during the production process a coating comprising at least one pyrolytic reflecting layer and at least two reflection enhancing layers, the last applied or outer of the enhancing layers also serving as a protective layer for the coating. The mirrors have a visible light reflection of at least 35% and less than 70% and exhibit a bright silver or chrome appearance. There is also a provided a mirror having such a coating.

Claims

1. A method of producing mirrors including depositing onto a ribbon of hot float glass during travel thereof through the float bath section of a float glass production line a coating comprising, in sequence, at least one pyrolytic reflecting layer, and at least two reflection enhancing layers, the outer of which is tin oxide whereby the mirrors exhibit a bright silver or chrome appearance and have a visible light reflection of at least 45% and less than 70%.

2. A method of producing mirrors as defined in claim 1, wherein said coating exhibits a substantially neutral color in reflection such that, as defined by reference to the CIELAB color scale system, a*² +b*² is less than 50 (Illuminant A).

3. A method of producing mirrors as defined in claim 2, wherein a*² +b*² is less than 32.

4. A method of producing mirrors as defined in claim 3, wherein a* is between -4 and +4 and b* between +4 and -4.

5. A method of producing mirrors as defined in claim 4, wherein said mirrors have a visible light reflection in the range of 45% to 65%.

6. A method of producing mirrors including depositing onto a ribbon of hot float glass during travel thereof through the float bath section of a float glass production line a coating comprising a pyrolytic reflecting layer and at least two reflection enhancing layers, the outer of which is also a protective layer and is selected from the group consisting of tin oxide, titanium dioxide and mixtures thereof whereby the mirrors exhibit a bright silver or chrome appearance and have a visible light reflection of at least 45% and less than 70%.

7. A method of producing mirrors as defined in claim 6, wherein said coating exhibits a substantially neutral color in reflection as defined by the CIELAB color scale system of a* between -4 and +4 and b* between +4 and -4 (Illuminant Å

).

8. A method of producing mirrors as defined in claim 7, wherein said pyrolytic reflecting layer comprises silicon and has a refractive index of at least 2.8.

9. A method of producing mirrors as defined in claim 8, wherein said silicon layer has a thickness in the range of 100 Å

to 220 Å

.

10. A method of producing mirrors as defined in claim 7, wherein the intermediate reflection enhancing layer comprises an oxide of silicon having a refractive index of less than 2.

11. A method of producing mirrors as defined in claim 10, wherein said oxide of silicon has a thickness in the range of 80 Å

to 220 Å

.

12. A method of producing mirrors as defined in claim 7, wherein said outer layer comprises an oxide selected from the group consisting of tin oxide, titanium dioxide and mixtures thereof in a thickness range of 80 Å

to 220 Å

.

13. A method of producing mirrors as defined in claim 12, wherein said outer layer has a refractive index in the range of 1.95 to 2.7 but in all events higher than the refractive index of the intermediate reflection enhancing layer.

14. A method of producing mirrors as defined in claim 13, wherein said protective layer comprises undoped tin oxide in a thickness range of 80 Å

to 220 Å

.

15. A method of producing mirrors including depositing onto a ribbon of hot float glass during travel thereof through the float bath section of a float glass production line a coating comprising a first layer consisting essentially of silicon having a refractive index of at least 2.8 and a thickness in the range of 100 Å

to 220 Å

, a second layer consisting essentially of an oxide of silicon having a refractive index of less than 2 and a thickness in the range of 80 Å

to 220 Å

, and a third layer consisting essentially of an oxide selected from the group consisting of tin oxide, titanium dioxide and mixtures thereof having a refractive index in the range of 1.95 to 2.7 but in all events higher than that of the second layer and a thickness in the range of 80 Å

to 220 Å

, whereby the mirrors have a visible light reflectance between 45% and 65% and a substantially neutral reflected color defined by the CIELAB color scale of a* between -4 and +4 and b* between +4 and -4 (Illuminant A).

16. A method of producing automotive mirrors exhibiting a bright silver or chrome appearance, including depositing, in sequence, onto a ribbon of hot float glass during travel thereof through the float bath section of a float glass production line a coating comprising at least one pyrolytic reflecting layer and at least two reflection enhancing layers, the outer of which is also a protective layer and composed of tin oxide, annealing the coated ribbon, cutting the annealed ribbon into blanks, and thereafter bending and, optionally, tempering said blanks to provide mirrors having a visible light reflectance of at least 45% and less than 70% and a reflected color defined by the CIELAB color scale system of a* between +4 and -4 and b* between -4 and +4 (Illuminant A).