Anti-fog element

• US 5,854,708 A
• Filed: 07/21/1997
• Issued: 12/29/1998
• Est. Priority Date: 07/26/1996
• Status: Expired due to Term

• Current Assignee: Murakami Corporation
• Original Assignee: Murakami Corporation
• Inventors: Nakamura, Masatoshi, Komatsu, Toru
• Primary Examiner(s): NGUYEN, THONG Q
• Application Number:
  US08/897,291
• Time in Patent Office: 526 Days
• Field of Search: 359/507, 359/509, 359/512, 359/601-609
• US Class Current: 359/512
• CPC Class Codes: C03C 17/256 Coating containing TiO2
• CPC Class Codes: C03C 17/3411 with at least two coatings of inorganic materials C03C17/36, C03C17/42 take precedence
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 2217/71 Photocatalytic coatings
• CPC Class Codes: C03C 2218/365 Coating different sides of a glass substrate

Abstract

An anti-fog element includes a transparent substrate such as a glass substrate, a transparent film of a photocatalyzer such as TiO₂ catalyzing a photocatalytic reaction on the transparent substrate, and a film of a transparent porous inorganic oxide such as SiO₂ formed on the film of the photocatalyzer and having a surface exhibiting a hydrophilic property. Organic matters etc. deposited in openings of the porous inorganic oxide film are dissolved and removed by a photocatalytic reaction caused by light excitation of the photocatalyzer film whereby the anti-fog property of the anti-fog element can be maintained over a long period of time.

Claims

1. An anti-fog element comprising:

a transparent substrate;

a transparent film of a photocatalyzer catalyzing a photocatalytic reaction formed on the transparent substrate; and

a transparent porous inorganic oxide film formed on the film of the photocatalyzer as the outer layer of said anti-fog mirror which is exposed to the air and having a surface exhibiting a hydrophilic property wherein said transparent film of photocatalyzer is made of TiO₂ and said porous inorganic oxide film is made of SiO₂.

2. An anti-fog element as defined in claim 1 further comprising a transparent electrode film formed between the surface of the transparent substrate and the photocatalyzer film, said transparent electrode film being made electrically conductive.

3. An anti-fog element as defined in claim 1 which is transparent in its entirety and is constructed as an automobile window.

4. An anti-fog element as defined in claim 1 further comprising a reflecting film formed on a rear surface of the transparent substrate to form an anti-fog mirror.

5. An anti-fog element as defined in claim 4 adapted for use as an automobile outer mirror.

6. An anti-fog element as defined in claim 1 further comprising a reflecting film formed on a rear surface of the transparent substrate and a resistance heat generating element laminated on the rear surface of the reflecting film to form an anti-fog mirror, said resistance heat generating element being made electrically conductive.

7. An anti-fog element as defined in claim 6 adapted for use as an automobile outer mirror.

8. An anti-fog element as defined in claim 1 further comprising a reflecting film formed on a rear surface of the transparent substrate to form an anti-fog mirror, said reflecting film being made electrically conductive and constituting a resistance heat generating element.

9. An anti-fog element as defined in claim 8 adapted for use as an automobile outer mirror.

10. An anti-fog element as defined in claim 1 wherein the TiO₂ film has an anatase structure.

11. An anti-fog mirror comprising:

a substrate;

a reflecting film formed on the front surface of said substrate;

a transparent film of a photocatalyzer catalyzing a photocatalytic reaction formed on said reflecting film; and

a transparent porous inorganic oxide film formed on the film of the photocatalyzer as the outer layer of said anti-fog mirror which is exposed to the air said photocatalyzer having a surface exhibiting a hydrophilic property wherein said transparent film of photocatalyzer is made of TiO₂ and said porous inorganic oxide film is made of SiO₂.