PHOTOCATALYST FILM, PROCESS FOR PRODUCING PHOTOCATALYST FILM, ARTICLE AND METHOD FOR HYDROPHILIZATION

• US 20100298120A1
• Filed: 10/16/2008
• Published: 11/25/2010
• Est. Priority Date: 10/16/2007
• Status: Abandoned Application

• Current Assignee: Ube-Nitto Kasei Company Limited (UBE Corporation)
• Original Assignee: Ube-Nitto Kasei Company Limited (UBE Corporation)
• Inventors: Kitagawa, Takeshi, Suematsu, Daisuke, Takami, Kazuyuki, Tanaka, Naoki
• Application Number:
  US12/738,364
• Publication Number:
  US 20100298120A1
• Time in Patent Office: Days
• US Class Current: 502/159
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 31/06 containing polymers organometallic polymers B01J31/123; polymer-bound organometallic complexes B01J31/165; coordination polymers B01J31/1691
• CPC Class Codes: B01J 35/33 Electric or magnetic properties
• CPC Class Codes: B01J 37/0215 Coating
• CPC Class Codes: B01J 37/10 in the presence of water, e.g. steam
• CPC Class Codes: C02F 1/32 with ultraviolet light
• CPC Class Codes: C02F 2305/10 Photocatalysts
• CPC Class Codes: Y02W 10/37 using solar energy
• 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 photocatalyst film of which at least one main surface contains photo-semiconductor particles; said main surface being a surface that becomes hydrophilic by irradiation with light, wherein the hydrophilization speed thereof when it is irradiated with light having a half-value width of 15 nm or less after kept in a dark place is less than 2 (l/deg/min/10⁵) in an irradiated-light wavelength region of 370 nm or more and is 2 (l/deg/min/10⁵) or more at least partly in an irradiated-light wavelength region of 300 to 360 nm.

Claims

1. A photocatalyst film of which at least one main surface contains photo-semiconductor crystallization product, said main surface being a surface that becomes hydrophilic by irradiation with light,

wherein the hydrophilization speed thereof when it is irradiated with light having a half-value width of 15 nm or less after kept in a dark place is less than 2 (l/deg/min/10⁵) in an irradiated-light wavelength region of 370 nm or more and is 2 (l/deg/min/10⁵) or more at least partly in an irradiated-light wavelength region of 300 to 360 nm

3. The photocatalyst film as recited in claim 1, wherein said photo-semiconductor crystallization product contains crystalline titanium oxide.

4. The photocatalyst film as recited in claim 3, wherein the content of the crystalline titanium oxide having a crystal diameter in the range of 1 to 10 nm in the total crystalline titanium oxide is 90% or more.

5. The photocatalyst film as recited in claim 3, wherein the content of the crystalline titanium oxide having a crystal diameter in the range of 1 to 10 nm in the total crystalline titanium oxide is 100%.

6. The photocatalyst film as recited in claim 3, wherein the content of the crystalline titanium oxide having a crystal diameter in the range of 1 to 10 nm in the at least one main surface is 3% or more.

7. The photocatalyst film as recited in claim 3, wherein the content of the crystalline titanium oxide having a crystal diameter in the range of 1 to 10 nm in the at least one main surface is 5% or more.

8. The photocatalyst film as recited in claim 3, which has a portion where at least five crystal grains exist when its cross section in the range of 50 nm×

50 nm is observed through a transmission electron microscope.

9. The photocatalyst film as recited in claim 3, wherein the at least one main surface contains crystalline titanium oxide and amorphous titanium oxide which exist together.

10. The photocatalyst film as recited in claim 3, wherein said crystalline titanium oxide is dispersed in the amorphous titanium oxide.

11. The photocatalyst film as recited in claim 3, which has a thickness of 1 μ

m or less.

12. The photocatalyst film as recited in claim 1, wherein said main surface has a contact angle of less than 20 degrees to water when the photocatalyst film is irradiated with sunlight.

13. The photocatalyst film as recited in claim 1, wherein a decomposing speed of methylene blue under the irradiation with artificial sunshine of 3 mW/cm² is 0.1 or less in terms of an absorbance-decreasing speed Δ

ABS/min at a maximum absorption wavelength of the methylene blue applied thereon.

14. The photocatalyst film as recited in claim 1, wherein said photo-semiconductor crystallization product is present in a hydrolysis condensation product of titanium alkoxide, and said titanium alkoxide has the form of a composite in which the titanium alkoxide forms a hydrolysis condensate with an organic polymer compound and the content thereof is continuously changed in the depth direction from a surface.

15. The photocatalyst film as recited in claim 1, which further contains fine particles of a metal compound other than the photo-semiconductor crystallization product.

16. The photocatalyst film as recited in claim 15, wherein the fine particles of a metal compound other than the photo-semiconductor crystallization product are silica fine particles.

17. The photocatalyst film as recited in claim 1, which further contains at least one metal compound selected from an inorganic metal salt, an organic metal salt and an alkoxide of metal other than titanium and silicon.

18. The photocatalyst film as recited in claim 17, wherein the metal compound is aluminum nitrate.

19. A process for producing the photocatalyst film recited in claim 3, which comprises heat-treating an amorphous titanium oxide film at a temperatures of 100°

C. or lower in the presence of water.

20. The process as recited in claim 19, wherein said amorphous titanium oxide film is formed by applying only once a coating agent containing a composite that is a hydrolysis condensation product of titanium alkoxide and an organic polymer compound, whereby the content of the hydrolysis condensation product of titanium alkoxide is continuously changed in the depth direction from a surface.

22. The photocatalyst film as recited in claim 1, wherein said photo-semiconductor crystallization product contains crystalline titanium oxide nano-tubes.

24. An article having the photocatalyst film recited in or the photocatalyst film obtained by the process recited in claim 19, on a surface of a substrate.

25. The article as recited in claim 24, wherein said substrate is an organic substrate.

26. The article as recited in claim 24, which further has an functional film having a thickness of 500 nm or less on a surface thereof.

27. The article as recited in claim 26, wherein said functional film contains silica.

28. A method of hydrophilization, which comprises using the article recited in claim 24, under irradiation with sunlight.

2. A photocatalyst film of which at least one main surface contains, as a photo-semiconductor crystallization product, photo-semiconductor particles having a crystal diameter in the range of 1 to 10 nm.

21. A photocatalyst film of which at least one main surface contains, as a photo-semiconductor crystallization product, photo-semiconductor nano-tubes having a tube thickness in the range of 1 to 10 nm.

23. The photocatalyst film as recited in claim 21, which further contains a binder component.