Substrate with a photocatalytic coating

• US 6,846,556 B2
• Filed: 04/05/2002
• Issued: 01/25/2005
• Est. Priority Date: 09/15/1995
• Status: Expired due to Term

• Current Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Original Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Inventors: Boire, Philippe, Talpaert, Xavier
• Primary Examiner(s): McNeil, Jennifer
• Application Number:
  US10/116,164
• Publication Number:
  US 20020150681A1
• Time in Patent Office: 1,026 Days
• Field of Search: 428/325, 428/428, 428/432, 428/701, 428/702, 427/164, 427/165, 427/167, 427/255, 359/580, 359/582, 359/585, 359/586
• US Class Current: 428/325
• CPC Class Codes: C03C 17/002 for flat glass, e.g. float glass
• CPC Class Codes: C03C 17/007 containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• CPC Class Codes: C03C 17/256 Coating containing TiO2
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 17/3441 comprising carbon, a carbide or oxycarbide
• CPC Class Codes: C03C 2217/211 SnO2
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2217/213 SiO2
• CPC Class Codes: C03C 2217/214 Al2O3
• CPC Class Codes: C03C 2217/22 ZrO2
• CPC Class Codes: C03C 2217/23 Mixtures
• CPC Class Codes: C03C 2217/24 Doped oxides
• CPC Class Codes: C03C 2217/45 Inorganic continuous phases
• CPC Class Codes: C03C 2217/477 Titanium oxide
• CPC Class Codes: C03C 2217/479 Metals
• CPC Class Codes: C03C 2217/71 Photocatalytic coatings
• CPC Class Codes: C03C 2217/94 Transparent conductive oxide layers [TCO] being part of a multilayer coating
• CPC Class Codes: C03C 2218/113 by sol-gel processes
• CPC Class Codes: C04B 2111/00818 Enzyme carriers
• CPC Class Codes: C04B 2111/80 Optical properties, e.g. transparency or reflexibility
• CPC Class Codes: C04B 35/00 : Shaped ceramic products characterised by their composition porous ceramic products C04B38/00; ceramic articles characterised by particular shape, see the relevant classes, e.g. linings for casting ladles, tundishes, cups or the like B22D41/02; ceramic substrates for microelectronic semi-conductors H01L23/15; Ceramics compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides other than as macroscopic reinforcing agents C22C; shaping of ceramics B28B; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products chemical preparation of powders of inorganic compounds C01; infiltration of sintered ceramic preforms with molten metal C04B41/51
• CPC Class Codes: C04B 41/0072 : Heat treatment
• CPC Class Codes: C04B 41/009 : characterised by the material treated
• CPC Class Codes: C04B 41/4562 : Photographic methods, e.g. making use of photo-sensitive materials
• CPC Class Codes: C04B 41/5027 : Oxide ceramics in general; Specific oxide ceramics not covered by C04B41/5029 - C04B41/5051
• CPC Class Codes: C04B 41/5041 : Titanium oxide or titanates
• CPC Class Codes: C04B 41/51 : Metallising , e.g. infiltration of sintered ceramic preforms with molten metal covering materials with metals in general C23C; ceramic compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides, other than as macroscopic reinforcing agents C22C; infiltration of preforms containing free metal, e.g. cermets C22C
• CPC Class Codes: C04B 41/5105 : with a composition mainly composed of one or more of the noble metals or copper
• CPC Class Codes: C04B 41/52 : Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
• CPC Class Codes: C04B 41/81 : Coating or impregnation
• CPC Class Codes: C04B 41/89 : for obtaining at least two superposed coatings having different compositions
• CPC Class Codes: G02F 1/1333 : Constructional arrangements; Manufacturing methodsG02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133502 : Antiglare, refractive index matching layers
• CPC Class Codes: G02F 1/1533 : structural features not otherwise provided for
• CPC Class Codes: G02F 1/157 : Structural association of cells with optical devices, e.g. reflectors or illuminating devices
• CPC Class Codes: Y10T 428/12611 : Oxide-containing component
• CPC Class Codes: Y10T 428/12993 : Surface feature [e.g., rough, mirror]
• CPC Class Codes: Y10T 428/24802 : Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24975 : No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/25 : Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/252 : Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
• CPC Class Codes: Y10T 428/256 : Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/265 : 1 mil or less
• CPC Class Codes: Y10T 428/31841 : Next to cellulosic
• CPC Class Codes: Y10T 428/31938 : Polymer of monoethylenically unsaturated hydrocarbon

Abstract

The subject of the invention is a glass-, ceramic- or vitroceramic-based substrate (1) provided on at least part of at least one of its faces with a coating (3) with a photocatalytic property containing at least partially crystalline titanium oxide.

It also relates to the applications of such a substrate and to its method of preparation.

Claims

1. A coated substrate which is a glass, ceramic or vitro-ceramic substrate provided on at least a portion of one of its faces with a coating having photocatalytic properties, and comprising titanium oxide at least partially crystallized in the anatase form, and wherein the coating has a refractive index of from about 2.30 to about 2.35.

2. The coated substrate of claim 1, which is a glass substrate.

3. The coated substrate of claim 1, which is a ceramic substrate.

4. The coated substrate of claim 1, which is a vitro-ceramic substrate.

5. The coated substrate of claim 1, wherein the titanium oxide is in the form of crystallites having an average size of between 0.5 and 100 nm.

6. The coated substrate of claim 1, wherein the titanium oxide is in the form of crystallites having an average size of between 1 and 50 nm.

7. The coated substrate of claim 1, wherein the titanium oxide is in the form of crystallites having an average size of between 10 and 40 nm.

8. The coated substrate of claim 1, wherein the titanium oxide is in the form of crystallites having an average size of between 20 and 30 nm.

9. The coated substrate of claim 1, wherein coating is deposited by chemical vapor deposition followed by annealing.

10. The coated substrate of claim 1, wherein the coating has a thickness between 5 nm and 1 micron.

11. The coated substrate of claim 1, wherein the coating has a thickness between 5 nm and 100 nm.

12. The coated substrate of claim 1, wherein the coating has a thickness between 10 and 80 nm.

13. The coated substrate of claim 1, wherein the coating has a thickness between 20 and 50 nm.

14. A process for a producing a coated substrate as claimed in claim 1, comprising:

chemical vapor depositing at least one titanium precursor on at least part of at least one face of a glass-, ceramic-, or vitroceramic-based substrate, to produce a photocatalytic coating containing at least partially crystalline titanium oxide,

wherein

the crystalline titanium oxide is in the form of crystallites with an average size of between 0.5 and 100 nm, and the thickness of the coating is between 5 nm and 1 micron.

15. The process of claim 14, wherein the substrate is glass.

16. The process of claim 14, wherein the substrate is a float-glass.

17. The process of claim 14, wherein the coating containing the at least partially crystalline titanium oxide has a degree of porosity of 65 to 99%.

18. The process of claim 14, wherein the coating containing the at least partially crystalline titanium oxide has a degree of porosity of 70 to 99%.

19. The process of claim 14, wherein the coating containing the at least partially crystalline titanium oxide has a degree of porosity of 70 to 90%.

20. The process of claim 14, wherein the crystalline titanium oxide is in the form of crystallites with an average size of between 0.5 and 60 nm.

21. The process of claim 14, wherein the crystalline titanium oxide is in the form of crystallites with an average size of between 1 and 50 nm.

22. The process of claim 14, wherein the crystalline titanium oxide is in the form of crystallites with an average size of between 10 and 40 nm.

23. The process of claim 14, wherein the crystalline titanium oxide is in the form of crystallites with an average size of between 20 and 30 nm.

24. The process of claim 14, wherein the thickness of the coating containing the at least partially crystalline titanium oxide is between 5 nm and 100 nm.

25. The process of claim 14, wherein the thickness of the coating containing the at least partially crystalline titanium oxide is 10 nm to 80 nm.

26. The process of claim 14, wherein the thickness of the coating containing the at least partially crystalline titanium oxide is between 5 nm and 20 nm.

27. The process of claim 14, wherein the crystalline titanium oxide is in the form of crystallites and the thickness of the coating containing the at least partially crystalline titanium oxide is at least two times greater than the mean diameter of the crystallites.

28. The process of claim 14, wherein the crystalline titanium oxide is in the anatase form, in the rutile form, or in the form of a mixture of anatase and rutile.

29. The process of claim 14, wherein the titanium oxide is crystalline with a degree of crystallization of at least 25%.

30. The process of claim 14, wherein the titanium oxide is crystalline with a degree of crystallization of between 30 and 80%.

31. The process of claim 14, wherein the surface of the coating containing the at least partially crystalline titanium oxide has a contact angle with water of less than 5 after exposure to light radiation.

32. The process of claim 14, wherein the surface of the coating containing the at least partially crystalline titanium oxide has a contact angle with water of less than 1 after exposure to light radiation.

33. The process of claim 14, wherein the RMS roughness of the coating containing the at least partially crystalline titanium oxide is between 2 and 20 nm.

34. The process of claim 14, wherein the RMS roughness of the coating containing the at least partially crystalline titanium oxide is between 5 and 20 nm.

35. The process of claim 14, wherein the chemical vapor deposition is conducted at a temperature of 400 to 600°

C.

36. The process of claim 14, wherein the chemical vapor deposition is conducted at a temperature of 400 to 600°

C.

37. The process of claim 14, wherein the titanium precursor is a titanium halide.

38. The process of claim 14, wherein the titanium precursor is an organometallic titanium compound.

39. The process of claim 14, wherein the titanium precursor is a titanium alcoholate.

40. The process of claim 14, wherein the titanium precursor is TiCl4.

41. The process of claim 14, wherein the titanium precursor is selected from the group consisting of Ti(OiPr)4, titanium diisopropoxide diacetylacetonate, titanium tetraoctyleneglycolate, and titanium acetylacetonate.

42. The process of claim 14, wherein the coating containing the at least partially crystalline titanium oxide also contains at least one additive capable of accentuating the photocatalytic activity of the titanium oxide.

43. The process of claim 14, further comprising incorporating metal particles or particles based on such a metal into the coating, wherein the metal is selected from the group consisting of cadmium, tin, tungsten, zinc, cerium, and zirconium.

44. The process of claim 14, further comprising inserting into the crystal lattice of the titanium oxide at least one the metal is selected from the group consisting of niobium, tantalum, iron, bismuth, cobalt, nickel, copper, ruthenium, cerium, and molybdenum.

45. The process of claim 14, further comprising covering at least part of the coating containing the at least partially crystalline titanium oxide with a layer of metal oxides or salts, wherein the metal is selected from the group consisting of iron, copper, ruthenium, cerium, molybdenum, vanadium, and bismuth.

46. The process of claim 14, wherein the coating containing the at least partially crystalline titanium oxide also contains an amorphous or partially crystalline oxide or mixture of oxides of the silicon oxide, tin oxide, zirconium oxide, or aluminum oxide type.

47. The process of claim 14, further comprising coating at least a portion of the coating containing the at least partially crystalline titanium oxide with a noble metal.

48. The process of claim 47, wherein the noble metal is selected from the group consisting of platinum, rhodium, silver, and palladium.

49. The process of claim 14, wherein

the substrate is coated with at least one thin layer, wherein the thin layer has an anti-static function, a thermal function or an optical function, or forms a barrier to the migration of alkali metals;

and

the coating containing the at least partially crystalline titanium oxide is coated on the thin layer.

50. The process of claim 49, wherein the thin layer has an anti-static function.

51. The process of claim 50, wherein the thin layer is based on a conductive material of the metal type or of the doped metal oxide type.

52. The process of claim 51, wherein the thin layer is based on ITO, SnO2:

F, ZnO;

F, ZnO;

Al, ZnO;

Sn or a metal oxide which is stoichiometrically deficient in oxygen.

53. The process of claim 52, wherein the metal oxide which is stoichiometrically deficient in oxygen is SnO2-x or ZnO2-x, wherein x<

2.

54. The process of claim 49, wherein the thin layer has a thermal function.

55. The process of claim 54, wherein the thin layer is based on a conductive material of the metal type or of the doped metal oxide type.

56. The process of claim 55, wherein the thin layer is based on ITO, SnO2:

F, ZnO;

F, ZnO;

Al, ZnO;

Sn or a metal oxide which is stoichiometrically deficient in oxygen.

57. The process of claim 56, wherein the metal oxide which is stoichiometrically deficient in oxygen is SnO2-x or ZnO2-x, wherein x<

2.

58. The process of claim 49, wherein the thin layer has an optical function.

59. The process of claim 58, wherein the thin layer is based on a conductive material of the metal type or of the doped metal oxide type.

60. The process of claim 59, wherein the thin layer is based on ITO, SnO2:

F, ZnO;

F, ZnO;

Al, ZnO;

Sn or a metal oxide which is stoichiometrically deficient in oxygen.

61. The process of claim 60, wherein the metal oxide which is stoichiometrically deficient in oxygen is SnO2-x or ZnO2-x, wherein x<

2.

62. The process of claim 58, wherein the thin layer is based on an oxide or on a mixture of oxides with a refractive index which is intermediate between that of the coating containing the at least partially crystalline titanium oxide and that of the substrate.

63. The process of claim 62, wherein the thin layer is composed of A1203, SnO2, 1n203, silicon oxycarbide, or silicon oxynitride.

64. The process of claim 49, wherein the thin layer forms a barrier to the migration of alkali metals.

65. The process of claim 64, wherein the thin layer is based on silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, A1203:

F, or aluminum nitride.

66. The process of claim 14, wherein the coating containing the at least partially crystalline titanium oxide is the final layer of a stack of anti-glare layers.

67. The process of claim 14, wherein the coating containing the at least partially crystalline titanium oxide is deposited in at least two successive stages.

68. The process of claim 14, wherein the coating containing the at least partially crystalline titanium oxide is subjected, after deposition, to at least one heat treatment of the annealing type.