Methods of making crystalline titania coatings

• US 20040202890A1
• Filed: 04/08/2003
• Published: 10/14/2004
• Est. Priority Date: 04/08/2003
• Status: Abandoned Application

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Steffek, Cory D., Kutilek, Luke A.
• Application Number:
  US10/409,417
• Publication Number:
  US 20040202890A1
• Time in Patent Office: Days
• US Class Current: 428/689
• CPC Class Codes: C01G 23/053 Producing by wet processes, e.g. hydrolysing titanium salts
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C03C 17/256 Coating containing TiO2
• CPC Class Codes: C23C 14/083 of refractory metals or yttrium
• CPC Class Codes: C23C 26/00 Coating not provided for in groups C23C2/00 - C23C24/00
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles

Abstract

A method is provided for shifting the amorphous to crystalline transition temperature of a titania coating. The method includes adding a dopant, such as Mo, V, Al, Zn, Zr, Li, K, Co, La, Ca, Ba, Si, Ag, Cu, Ni, Mg, Mn, Cd, Fe, Cr, Tb, Y, Sn, Ge, and/or Pd to a titania-containing material. The doped material can then be applied, e.g., by spray pyrolysis, onto a substrate. A coated article is also provided.

Claims

1. A method of shifting the amorphous to crystalline transition temperature of a titania coating material, comprising the steps of:

adding at least one dopant to a titania-containing material, the dopant selected from at least one of Mo, V, Al, Zn, Zr, Li, K, Co, La, Ca, Ba, Si, Ag, Cu, Ni, Mg, Mn, Cd, Fe, Cr, Tb, Y, Sn, Ge, and Pd, and mixtures or combinations thereof.

2. The method of claim 1, wherein the dopant is vanadium and is present in an amount of 1 to 6 atomic percent.

3. The method of claim 1, wherein the dopant is aluminum and is present in an amount of less than 2 atomic percent.

4. The method of claim 1, wherein the dopant is molybdenum and is present in an amount of less than 2 atomic percent.

5. The method of claim 1, including applying the titania precursor material and dopant by spray pyrolysis.

6. The method of claim 1, including applying the titania precursor material and dopant by chemical vapor deposition.

7. The method of claim 1, wherein the precursor material and dopant are applied at a temperature in the range of 1100°

F. to 1200°

F. (593°

C. to 648°

C.).

8. The method of claim 1, wherein the precursor material and dopant are applied at a temperature in the range of 400°

F. to 1100°

F. (204°

C. to 593°

C.).

9. The method of claim 1, wherein the dopant is vanadium and is present in an amount of 1 to 8 atomic percent.

10. The method of claim 9, wherein the coating includes a crystal lattice comprising a monoclinic crystal system.

11. The method of claim 1, wherein the vanadium is present in an amount of 5 to 7 atomic percent and the coating includes monoclinic and tetragonal (anatase) crystal systems

12. The method of claim 1, including heating the coated substrate to a temperature of at least 900°

F. (482°

C.) for 30 minutes.

13. The method of claim 1, wherein the coating is photoactive

14. The method of claim 1, wherein the coating is photohydrophilic.

15. The method of claim 1, wherein the dopant is aluminum and is applied by spray pyrolysis at a deposition temperature in the range of 1100°

F. to 1200°

F. (593°

C. to 648°

C.).

16. A coated article, comprising:

a substrate; and

a titania doped coating formed over the substrate, the coating comprising at least one dopant selected from Mo, V, Al, Zn, Zr, Li, K, Co, La, Ca, Ba, Si, Ag, Cu, Ni, Mg, Mn, Cd, Fe, Cr, Tb, Y, Sn, Ge, and Pd, and mixtures or combinations thereof.

17. The coated article of claim 16, wherein the dopant is vanadium and is present in an amount of 1 to 8 atomic percent.

18. The coated article of claim 16, wherein the coating has a thickness in the range of greater than 0 Å

to 500 Å

.

19. The coated article of claim 16, wherein the coating includes a crystal lattice comprising a monoclinic crystal system.

20. The coated article of claim 16, wherein the coating has a grain size of greater than 60 nm.

21. The coated article of claim 16, wherein the coating has a grain size in the range of greater than 60 nm to 120 nm.

22. The coated article of claim 16, wherein the coating is photohydrophilic.

23. A pigment, comprising:

a vanadium doped titania material having a crystalline structure comprising a monoclinic crystal system.

24. The pigment of claim 23, wherein the vanadium is present in the range of 1 atomic percent to 8 atomic percent of the titania material.

25. The pigment of claim 23, wherein the vanadium is present in the range of 5 atomic percent to 7 atomic percent of the titania material.