Method for preparing a photocatalytic coating integated into glazing heat treatment

• US 20060201203A1
• Filed: 07/21/2004
• Published: 09/14/2006
• Est. Priority Date: 07/23/2003
• Status: Abandoned Application

• Current Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Original Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Inventors: Nadaud, Nicolas, Labrousse, Laurent
• Application Number:
  US10/565,001
• Publication Number:
  US 20060201203A1
• Time in Patent Office: Days
• US Class Current: 65/60.500
• CPC Class Codes: C03C 17/2456 Coating containing TiO2
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3441 comprising carbon, a carbide or oxycarbide
• CPC Class Codes: C03C 2217/71 Photocatalytic coatings
• CPC Class Codes: C03C 2218/365 Coating different sides of a glass substrate

Abstract

The invention relates to a method for preparing a material exhibiting photocatalytic properties and comprising at least partially crystallised titanium oxide, in particular in the form of anatase at temperatures higher than 600° C. Said invention also relates to a glass sheet whose at least one face is coated with a material which contains titanium oxide and is thermally treatable at a temperature higher than 600° C. by such methods as quenching and/or bowing, but preserving the photocatalytic activity and required optical properties thereof for a clean-surface glazing. The invention also relates to a monolithic foliated glazing which is simple or multilayer and comprises said glass sheet, and to the use of said glazing for a building, a transport vehicle, as an ordinary glazing, for interior use, street furniture, mirror, a display system screen and photovolatic glazing.

Claims

1. A method of preparing a material exhibiting photocatalytic properties comprising a coating comprising at least partially crystallized titanium oxide, comprising

heating a transparent or semi-transparent substrate,

wherein the substrate comprises a coating of titanium dioxide on at least a first face of the substrate,

to a temperature greater than 600°

C., and

conducting crystallization of the titanium dioxide at the temperature greater than 600°

C.

thereby at least partially crystallizing the titanium dioxide and forming the material.

2. The method of claim 1, wherein the temperature is greater than 630°

C.

3. The method of claim 1, further comprising a toughening treatment, a bending treatment, or a toughening and a bending treatment carried out on the material.

4. The method of claim 1, wherein the titanium dioxide coating is formed by deposition, wherein the substrate is a glass or glass-ceramic substrate, and wherein the substrate, optionally, has been provided beforehand with one or more functional multilayers, one or more functional layers, or a combination thereof.

5. The method of claim 4, further comprising the deposition, on at least a second face of the substrate, of one or more functional multilayers, one or more functional layers, or a combination thereof.

6. The method of claim 5, wherein the heating and conducting are conducted after the depositions on at least the first and second faces.

7. The method of claim 5, wherein the deposition on the at least first and second faces is carried out by cathode sputtering.

8. The method of claim 7, wherein the deposition on the at least first and second faces is carried out in line simultaneously or almost simultaneously, along substantially identical directions, and in opposite senses.

12. A single or multiple, laminated, monolithic glazing, comprising the material exhibiting photocatalytic properties obtained in accordance with the method of claim 1, wherein the substrate is a constituent glass sheet.

13. The glazing as claimed in claim 12, wherein, beneath the coating of a material exhibiting photocatalytic properties, the at least first face of the substrate comprises at least one layer, and wherein the at least one layer forms a barrier to the migration of alkali metals from the glass liable to result from the application of temperatures in excess of 600°

C.

14. The glazing as claimed in claim 12, wherein at least a second face of the continuous glass sheet further comprises one or more functional multilayers, one or more functional layers, or a combination thereof, selected from the group consisting of a thermal control, a low-emissivity multilayer, a layer with an optical functionality, wherein the optical functionality is seleted from the group consisting of antireflection, light radiation filtration, coloration, and scattering, a layer comprising an antisoiling photocatalytic material, a hydrophilic layer, a hydrophobic layer, a network of conductive threads, a conductive layer, an antenna, an antistatic layer, and a combination thereof.

15. The application of glazing of claim 14, wherein the glass sheet comprises at least one property selected from the group consisting of self cleaning, antifogging, anticondensation and antisoiling.

16. The method of claim 1, wherein the least partially crystallized titanium oxide is in anatase form.

17. The method of claim 2, wherein the least partially crystallized titanium oxide is in anatase form.

18. The method of claim 3, wherein the least partially crystallized titanium oxide is in anatase form.

19. The method of claim 4, wherein the least partially crystallized titanium oxide is in anatase form.

20. The method of claim 5, wherein the least partially crystallized titanium oxide is in anatase form.

9. A glass sheet, at least one face of which comprises a coating of a material comprising titanium oxide, wherein the glass sheet is capable of undergoing a heat treatment at above 600°

C. while still preserving the photocatalytic activity and the optical quality that are required for antisoiling glazing.

10. The glass sheet as claimed in claim 9, wherein the mean colorimetric variation Δ

E in reflection on the coating side induced by the heat treatment at above 600°

C. is at most 2.8.

11. A laminated glazing, comprising the glass sheet of claim 9 and at least one additional functional layer, at least one functional multilayer, or a combination thereof.