Photocatalyst composite and process for producing the same

• US 6,277,346 B1
• Filed: 05/27/1997
• Issued: 08/21/2001
• Est. Priority Date: 06/28/1993
• Status: Expired due to Term

• Current Assignee: Toto Limited
• Original Assignee: Akira Fujishima, Ishihara Sangyo Kaisha Limited, Kazuhito Hashimoto
• Inventors: Watanabe, Mitsuru, Fujishima, Akira, Murakami, Hajime, Hashimoto, Kazuhito, Murasawa, Sadao, Fukui, Yasuro
• Primary Examiner(s): Beck, Shrive
• Assistant Examiner(s): BARR, MICHAEL E
• Application Number:
  US08/863,393
• Time in Patent Office: 1,547 Days
• Field of Search: 477/567, 477/583, 477/584, 502/300, 502/350, 502/326, 502/330, 502/329, 502/353, 428/703, 428/206, 428/208, 423/239.1, 423/239.2
• US Class Current: 423/239.2
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 37/0219 the coating containing organic compounds
• 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 17/3405 with at least two coatings of organic materials C03C17/36, C03C17/42 take precedence
• CPC Class Codes: C03C 2204/02 Antibacterial glass, glaze or enamel
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2217/25 Metals
• CPC Class Codes: C03C 2217/29 Mixtures
• CPC Class Codes: C03C 2217/445 Organic continuous phases
• 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 2218/11 from solutions or suspensions
• CPC Class Codes: Y10S 430/148 Light sensitive titanium compound containing
• CPC Class Codes: Y10S 430/151 Matting or other surface reflectivity altering material

Abstract

A photocatalyst composite is provided which comprise a substrate having particles of a photocatalyst such as titanium oxide, adhered thereon via a less degradative adhesive such as a fluorinated polymer comprising a copolymer of a vinyl ester and/or vinyl ether and a fluoroolefin, or a silicon based polymer or cement. Furthermore, a process for producing the photocatalyst composite and a coating composition containing the photocatalyst composite are provided.

Claims

1. A method for removing NOx comprising the steps of exposing a photocatalyst composite for removing NOx to an atmosphere containing NOx wherein the photocatalyst composite includes a mixture of photocatalyst particles having a photocatalytic function with cement as a less degradative adhesive adhered on a substrate.

2. The method for removing NOx according to claim 1, wherein the amount of said photocatalyst particles having a photocatalytic function is within the range of 5 to 40% by volume based on the total amount of said photocatalyst particles and said less degradative adhesive.

3. The method for removing NOx according to claim 1, wherein on the substrate is provided a first layer comprising an adhesive without containing any photocatalyst particles and further on said first layer is provided a second layer comprising said mixture of said photocatalyst particles with said less degradative adhesive.

4. The method for removing NOx according to claim 1, wherein said photocatalyst particles comprise at least one selected from the group consisting of metals and metal compounds of V, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Pt and Au as a second component inside each of said photocatalyst particles and/or on the surfaces thereof.

5. The method for removing NOx according to claim 1, wherein said photocatalyst particles are of titanium oxide.