Coated substrate with high reflectance

• US 7,195,821 B2
• Filed: 11/02/2004
• Issued: 03/27/2007
• Est. Priority Date: 03/20/1998
• Status: Expired due to Fees

• Current Assignee: Glaverbel
• Original Assignee: Glaverbel
• Inventors: Tixhon, Eric
• Primary Examiner(s): McNeil; Jennifer
• Assistant Examiner(s): BLACKWELL, GWENDOLYN
• Application Number:
  US10/979,099
• Publication Number:
  US 20050142365A1
• Time in Patent Office: 875 Days
• Field of Search: 428/432, 428/697, 428/698, 428/699, 428/701, 428/702
• US Class Current: 428/432
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• 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 2217/71 Photocatalytic coatings
• CPC Class Codes: C03C 2217/75 Hydrophilic and oleophilic coatings
• CPC Class Codes: C03C 2218/112 by spraying
• CPC Class Codes: C03C 2218/152 by cvd
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/407 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A transparent coated substrate with rather high reflectance, especially for use as in exterior glazing panels for buildings or automotives, is provided by a substrate carrying a coating stack comprising a pyrolytically-formed main layer containing oxide of tin and an outer layer comprising TiO₂, whereby the so-coated substrate has a reflectance (RL) of more than 10%. The coated substrate advantageously shows photocatalytic and hydrophilic properties.

Claims

1. A coated transparent substrate carrying a coating stack, the coating stack being comprised of:

an undercoat positioned between the substrate and the main coating layer and which imparts to the coated substrate a more neutral tint in reflection;

a pyrolytically-formed main coating layer which comprises oxides of tin, and

an outer reflective layer comprising titanium oxide and having a refractive index in the range 2.0 to 2.8,

whereby the so-coated substrate has a reflectance (RL) of more than 15%; and

a purity in reflection of less than 10%.

2. A coated transparent substrate as claimed in claim 1, in which the outer reflective layer further contains an oxide of one or more of nickel, tin, zinc and zirconium.

3. A coated transparent substrate as claimed in claim 2, in which the outer reflective layer comprises oxides of titanium and tin.

4. A coated transparent substrate as claimed in claim 3, in which the outer reflective layer has a geometric thickness in the range 30 to 150 nm.

5. A coated transparent substrate as claimed in claim 2, in which the outer reflective layer has a geometric thickness ranging from 3 to 150 nm.

6. A coated transparent substrate as claimed in claim 3, in which the outer reflective layer comprises at least 50% by volume of tin oxide and at least 30% by volume of titanium oxide.

7. A coated transparent substrate as claimed in claim 4, in which the outer reflective layer has a thickness in the range 60 to 70 nm.

8. A coated transparent substrate as claimed in claim 1, in which the coating stack further comprises an intermediate layer positioned between the main coating layer and the outer reflective layer.

9. A coated transparent substrate as claimed in claim 8, in which the intermediate layer comprises aluminum oxide or silicon oxide.

10. A coated transparent substrate as claimed in claim 1, in which the main layer has a geometric thickness in the range of at least 250 nm.

11. A coated transparent substrate as claimed in claim 1, in which the main layer contains oxides of tin and antimony.

12. A coated transparent substrate as claimed in claim 11, in which the Sb/Sn molar ratio in the main coating layer is in the range of 0.01 to 0.5.

13. A coated transparent substrate as claimed in claim 12, in which the Sb/Sn molar ratio in the main coating layer is in the range of 0.03 to 0.21.

14. A coated transparent substrate as claimed in claim 1, wherein the undercoat is selected from oxides of silicon, aluminum oxinitride, and mixtures of oxides of aluminum and of vanadium.

15. A coated transparent substrate as claimed in claim 1, in which the geometric thickness of the undercoat is in the range of 30 to 100 nm.

16. A coated transparent substrate as claimed in claim 15, in which the geometric thickness of the undercoat is in the range of 60 to 75 nm.

17. A coated transparent substrate as claimed in claim 1, in which the undercoat imparts to the coated substrate a more neutral tint in reflection.

18. A coated transparent substrate as claimed in claim 1, having a luminous transmittance (TL) of at least 40%.

19. A coated transparent substrate as claimed in claim 1, having a luminous transmittance (TL) of at least 60%.

20. A coated transparent substrate as claimed in claim 1, having a luminous transmittance (TL) of at least 65%.

21. A coated transparent substrate as claimed in claim 1, having a maximum reflectance (RL) of 30%.

22. A coated transparent substrate as claimed in claim 1, having a maximum reflectance (RL) of 25%.

23. A coated transparent substrate as claimed in claim 1, having a maximum reflectance (RL) of 20%.

24. A glazing panel comprising a coated transparent substrate as claimed in claim 1.

25. A glazing panel comprising at least two substrate sheets of which one is a coated transparent substrate as claimed in claim 1.

26. A building glazing panel as claimed in claim 1.

27. A vehicle window glazing panel as claimed in claim 1.

28. A coated transparent substrate as claimed in claim 1, in which the outer reflective layer has a geometric thickness ranging from 3 to 150 nm.

29. A coated transparent substrate as claimed in claim 1, in which the main layer comprises oxides of tin and antimony and the Sb/Sn molar ratio in the main coating layer is in the range 0.01 to 0.5.

30. A coated transparent substrate as claimed in claim 29, in which the Sb/Sn molar ratio is in the range 0.03 to 0.21.

31. A coated transparent substrate as claimed in claim 1, in which the main coating layer further includes an additive comprising one or more of aluminum, chromium, cobalt, iron, manganese, magnesium, nickel, titanium, vanadium, zinc and zirconium.

32. A coated transparent substrate as claimed in claim 31, in which the additive is selected from chromium, iron and magnesium.

33. A coated transparent substrate as claimed in claim 1, in which the undercoat comprises one or more oxides of silicon.

34. A coated transparent substrate as claimed in claim 1, in which the undercoat comprises alumina.

35. A coated transparent substrate as claimed in claim 1, in which the geometric thickness of the undercoat is in the range 60 to 75 nm.