Coated substrates

• US 20030064231A1
• Filed: 05/13/2002
• Published: 04/03/2003
• Est. Priority Date: 06/08/1999
• Status: Active Grant

• Current Assignee: Johannes Andreas Maria Ammerlaan, Richard Joseph Mccurdy, Simon James Hurst
• Original Assignee: Johannes Andreas Maria Ammerlaan, Richard Joseph Mccurdy, Simon James Hurst
• Inventors: Maria Ammerlaan, Johannes Andreas, Hurst, Simon James, McCurdy, Richard Joseph
• Granted Patent: US 6,929,862 B2
• Time in Patent Office: Days
• US Class Current: 428/432
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 35/004 Photocatalysts
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 37/0215 Coating
• 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 17/10761 containing vinyl acetal
• CPC Class Codes: C03C 17/2456 Coating containing TiO2
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2217/71 Photocatalytic coatings
• CPC Class Codes: C03C 2218/152 by cvd
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium

Abstract

A coated substrate, especially a glass substrate, such coated substrate having high photocatalytic activity and low visible light reflection as well as being highly abrasion resistant. Preferably, the coating is a titanium oxide coating, the photolytic activity is greater than 5×10⁻³ cm⁻¹min⁻¹, and coating side visible light reflection is 35% or lower.

Claims

1. A photocatalytically active coated substrate comprising a substrate having a photocatalytically active titanium oxide coating on one surface thereof, characterised in that the coated surface of the substrate has a photocatalytic activity of greater than 5×

10<sup>−

3 cm−

1</sup>min<sup>−

1</sup>and in that the coated substrate has a visible light reflection measured on the coated side of 35% or lower.

2. A photocatalytically active coated substrate as claimed in claim 1 wherein the coated surface of the substrate has a photocatalytic activity of greater than 1×

10<sup>−

2</sup> cm<sup>−

1</sup>min<sup>−

1</sup>.

3. A photocatalytically active coated substrate as claimed in claim 2 wherein the coated surface of the substrate has a photocatalytic activity of greater than 3×

10<sup>−

2</sup> cm<sup>−

1</sup>min<sup>−

1</sup>.

4. A photocatalytically active coated substrate as claimed in claim 1 wherein the coated substrate has a visible light reflection measured on the coated side of 20% or lower.

5. A photocatalytically active coated substrate as claimed in claim 4 wherein the coated substrate has a visible light reflection measured on the coated side of 15% or lower.

6. A photocatalytically active coated substrate as claimed in claim 1 wherein the substrate comprises a glass substrate.

7. A photocatalytically active coated substrate as claimed in claim 1 wherein the coated substrate has an alkali metal ion-blocking underlayer between the surface of the substrate and the photocatalytically active titanium oxide coating.

8. A photocatalytically active coated substrate as claimed in claim 7 wherein the alkali metal ion-blocking underlayer is a layer of silicon oxide.

9. A photocatalytically active coated substrate as claimed in claim 1 wherein the photocatalytically active titanium oxide coating has a thickness of 30 nm or lower.

10. A photocatalytically active coated substrate as claimed in claim 9 wherein the photocatalytically active titanium oxide coating has a thickness of 20 nm or lower.

11. A photocatalytically active coated substrate as claimed in claim 10 wherein the photocatalytically active titanium oxide coating has a thickness in the range 2 nm to 20 nm.

12. A photocatalytically active coated substrate as claimed in claim 1 wherein the coated surface of the substrate has a static water contact angle of 20°

or lower.

13. A photocatalytically active coated substrate as claimed in claim 1 wherein the coated substrate has a haze of less than 1%.

14. A photocatalytically active coated substrate as claimed in claim 1 produced by a process as claimed in claim 1.

15. A photocatalytically active coated substrate as claimed in claim 1 wherein the coated surface of the substrate is durable to abrasion, such that the coated surface remains photocatalytically active after it has been subjected to 300 strokes of the European standard abrasion test.

16. A photocatalytically active coated substrate as claimed in claim 15 wherein the coated surface remains photocatalytically active after it has been subjected to 500 strokes of the European standard abrasion test.

17. A photocatalytically active coated substrate as claimed in claim 16 wherein the coated surface remains photocatalytically active after it has been subjected to 1000 strokes of the European standard abrasion test.

18. A photocatalytically active coated substrate as claimed in claim 16 wherein the haze of the coated substrate is 2% or lower after being subjected to the European abrasion test.

19. A photocatalytically active coated substrate as claimed in claim 1 wherein the coated surface of the substrate is durable to humidity cycling such that the coated surface remains photocatalytically active after the coated substrate has been subjected to 200 cycles of the humidity cycling test.

23. A multiple glazing unit comprising a first glazing pane of a coated substrate as claimed in claim 1 in spaced, opposed relationship to a second glazing pane.

24. Laminated glass comprising a first glass ply of a coated glass as claimed in claim 1, a polymer interlayer, and a second glass ply.

20. A durable photocatalytically active coated glass comprising a glass substrate having a coating on one surface thereof, said coating comprising an alkali metal ion-blocking underlayer and an outer photocatalytically active titanium oxide layer, wherein the coated surface of the substrate is durable to abrasion such that the coated surface remains photocatalytically active after it has been subjected to 300 strokes of the European standard abrasion test.

21. A durable photocatalytically active coated glass as claimed in claim 20 wherein the coated glass has a visible light reflection measured on the coated side of 35% or lower, and wherein the photocatalytically active titanium oxide layer has a thickness of 30 mn or lower.

22. A coated glass comprising a glass substrate having a photocatalytically active titanium oxide coating on one surface thereof, characterised in that the coated surface of the glass has a photocatalytic activity of greater than 8×

10<sup>−

2</sup> cm<sup>−

1</sup>min<sup>−

1</sup> and in that the coated glass has a visible light reflection measured on the coated side of less than 20%.