Photocatalyst-carrying structure and photocatalyst coating material

• US 6,228,480 B1
• Filed: 03/18/1998
• Issued: 05/08/2001
• Est. Priority Date: 06/19/1995
• Status: Expired due to Term

• Current Assignee: Nippon Soda Company Limited
• Original Assignee: Nippon Soda Company Limited
• Inventors: Abe, Shinji, Yoshimoto, Tetsuo, Fukayama, Shigemichi, Kimura, Nubuo
• Primary Examiner(s): NAKARANI, DHIRAJLAL S
• Application Number:
  US08/981,303
• Time in Patent Office: 1,147 Days
• Field of Search: 428/328, 428/329, 428/330, 428/331, 428/429, 428/447, 428/448, 428/451, 428/452, 106/287.13, 106/287.16, 106/287.19, 502/158, 502/236, 502/242, 502/350
• US Class Current: 428/328
• 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: B01J 37/0225 of metal substrates
• CPC Class Codes: B01J 37/036 to form a gel or a cogel
• CPC Class Codes: C03C 17/42 at least one coating of an organic material and at least one non-metal coating
• 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 2217/478 Silica
• CPC Class Codes: C03C 2217/71 Photocatalytic coatings
• CPC Class Codes: Y10T 428/256 Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/257 Iron oxide or aluminum oxide
• CPC Class Codes: Y10T 428/258 Alkali metal or alkaline earth metal or compound thereof
• CPC Class Codes: Y10T 428/259 Silicic material
• CPC Class Codes: Y10T 428/31612 As silicone, silane or siloxane
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane
• CPC Class Codes: Y10T 428/31667 Next to addition polymer from unsaturated monomers, or aldehyde or ketone condensation product

Abstract

The present invention provides a photocatalyst-carrying structure which has a structure, wherein an adhesive layer is provided in between a photocatalyst layer and a substrate, the adhesive layer is composed of silicon-modified resin, polysiloxane-containing resin or colloidal silica-containing resin, and for forming the photocatalyst layer a composition comprising a metal oxide gel or a metal hydroxide gel and a photocatalyst is used. Further, the present invention also provides a photocatalyst coating agent for producing a photocatalyst-carrying structure which contains silicon compound, at least one metal oxide sol or metal hydroxide sol, and at least one photocatalyst powder or sol.

Claims

1. A photocatalyst-carrying structure comprising a photocatalyst layer, an adhesive layer and a substrate, wherein the adhesive layer is disposed between the photocatalyst layer and the substrate and comprises

a silicon-modified resin, the adhesive layer containing from 2 to 60% by weight silicon;

a resin containing colloidal silica, wherein the adhesive layer comprises from 5 to 40% by weight of said colloidal silica;

or

a resin containing polysiloxane, which is a polycondensation product of a compound represented by a formula (1)

2. The photocatalyst-carrying structure according to claim 1, wherein the silicon-modified resin used for the adhesive layer is acryl-silicon resin.

3. The photocatalyst-carrying structure according to claim 1, wherein the adhesive layer is composed of a resin containing polysiloxane, and said polysloxane is made of either a hydrolyzed product of silicon alkoxide containing at least one C₁-C₅ alkoxy or a compound prepared via the said hydrolyzed product.

4. The photocatalyst-carrying structure according to claim 1, wherein the adhesive layer is made of silicon-modified resin containing polysiloxane.

5. The photocatalyst-carrying structure according to claim 1, wherein the adhesive layer is made of a resin containing colloidal silica and the diameter of the particles of the colloidal silica is 10 nm or less.

6. The photocatalyst-carrying structure according to claim 1, wherein the adhesive layer is made of silicon-modified resin containing colloidal silica.

7. The photocatalyst-carrying structure according to claim 1, wherein the metal oxide gel or the metal hydroxide gel contained in the photocatalyst layer is gel and their specific surface area dried at 150°

C. is 100 m²/g or more, and is composed of one or more gels of metals selected from a group consisting of silicon, aluminium, titanium, zirconium, magnesium, niobium, tantarum, tungsten and tin, respectively.

8. The photocatalyst-carrying structure according to claim 1, wherein the photocatalyst layer is a photocatalyst complex composed of more than 2 kinds of metal oxide gels or metal hydroxide gels and a phohtocatalyst, and the adhesive property of the complex after dipping it into boiling water which shows an electroconductivity of 200 μ

S/cm at 20°

C. is expressed as an evaluated-point of 6 or more according to cross-cut Scotch tape test provided in JIS K5400.

9. The photocatalyst-carrying structure according to claim 8, wherein the photocatalyst layer is composed of a photocatalyst complex, which comprises oxide gel or hydroxide gel of one or more metals selected from a group consisting of aluminium, titanium, zirconium and niobium, and silicon, and has a specific surface area after drying at 150°

C. of 50 m²/g or more.

10. The photocatalyst-carrying structure according to claim 1, wherein the photocatalyst layer is composed of a photocatalyst complex which contains either silicon-modified resin or silane compound 10 to 50% by weight, either a metal oxide gel or a metal hydroxide gel from 15 to 85% by weight on the solid component basis and a photocatalyst from 5 to 75% by weight, and the photocatalyst complex has an adhesive property of point 6 or more expressed from the criterion according to cross-cut Scotch tape test provided in JIS K5400 after dipping it for 15 min. into boiling water which shows an electroconductivity of 200 μ

S/cm at 20°

C.

11. The photocatalyst-carrying structure according to claim 10, wherein the silicon-modified resin or the silane compound contained in the photocatalyst layer is acryl-silicon resin, epoxy-silicon resin or a silane coupler.

12. The photocatalyst-carrying structure according to claim 1, characterized in that the adhesive property of the structure after exposing it to black light radiation of which ultraviolet light intesity is 3 mW/cm² for 500 hours at 40°

C. and 90% R.H. is evaluated as point 6 or more according to the criterion of cross-cut Scotch tape test provided in JIS K5400.

13. A photocatalyst-carrying glass, characterized in that the glass has a constitution wherein an adhesive layer is provided in between a photocatalyst layer and a substrate, and the adhesive layer and the photocatalyst layer described in claim 1 are used therein.

14. A photocatalyst-carrying plastic molding which has a structure wherein an adhesive layer is provided in between a photocatalyst layer and a plactic molding, and the photocatalyst layer and the adhesive layer used therein are the ones described in claim 1.

15. A sticking film prepared by applying a sticker onto the back side of the photocatalyst-carrying plastic film described in claim 14.

16. A photocatalyst-carrying cloth which has a structure wherein an adhesive layer is provided in between a photocatalyst layer and a substrate, and the photocatalyst layer and the adhesive layer used therein are the ones described in claim 1.

17. A photocatalyst-carrying metal which has a structure wherein an adhesive layer is provided in between a photocatalyst layer and the metal, and the photocatalyst layer and the adhesive layer used therein are the ones described in claim 1.

18. A photocatalyst-carrying timber and a photocatalyst-carrying wooden material which respectively has a structure wherein an adhesive layer is provided in between a photocatalyst layer and the timber or the wooden material, and the photocatalyst layer and the adhesive layer used therein are the ones described in claim 1.

19. The structure of claim 1 wherein the adhesive layer comprises a silicon modified resin.

20. The structure of claim 1 wherein the adhesive layer comprises a resin containing colloidal silica.

21. The structure of claim 1 wherein the adhesive layer comprises a resin comprising polysiloxane.

22. A coating material of a photocatalyst comprising 0.001 to 5% by weight silicon compounds;

0.1 to 30% by weight of a metal oxide sol and/or a metal hydroxide sol, on the solid component basis and from 0.1 to 30.0% by weight on the solid component basis a photocatalyst powder and/or sol.

23. The coating material of a photocatalyst according to claim 22, wherein the silicon compound is an alkoxy silane compound represented by a general formula (2),

24. The coating material of a photocatalyst according to claim 22, characterized in that the metal oxide sol and/or the matal hydroxide sol comprise a metal selected from a group consisting of silicon, aluminium, titanium, zirconium, niobium, tantalum, magnesium, tungsten and tin, and the specific surface area of such sol after drying at 150°

C. is 50 m²/g or more, respectively.

25. The coating material of a photocatalyst according to claim 22, characterized in that the silicon compound is composed of one or more compounds selected from a group consisting of tetramethoxy silane, tetraethoxy silane, methyl trimethoxy silane, methyl triethoxy silane and their hydrolized products.

26. A coating of a photocatalyst used for producing a photocatalyst-carrying structure wherein an adhesive layer is disposed between a photocatalyst layer and a substrate wherein the coating comprises two coating materials (1) and (2), wherein

(1) is a coating material for forming said adhesive layer and wherein (1) comprises a resin component, said resin component comprising from 1 to 50% by weight of a silicon-modified resin containing 2-60% by weight of silicon and either a resin containing 3-60% by weight of polysiloxane or a resin containing 5-40% by weight of colloidal silica, and

(2) a coating material for forming a photocatalyst layer onto the adhesive layer comprise 0.001-5% by weight of a silicon compound, 0.1-30% by weight of a metal oxide sol and/or a metal hydroxide sol on the solid component basis and 0.1-30% by weight of a photocatalyst powder and/or sol on the solid component basis.

27. The coating material of a photocatalyst according to claim 26, wherein the resin contained in the coating material for forming an adhesive layer is a resin containing polysiloxane, and said polysiloxane is the hydrolized product of alkoxy silane with an alkoxy group having 1-5 carbon atoms or an other compound produced from said hydrolized product.

28. The coating material of a photocatalyst according to claim 26, wherein the resin contained in the coating material for forming an adhesive layer is a resin containing colloidal silica, and the diameter of said colloidal silica is 10 nm or less.

29. The coating material of a photocatalyst according to claim 26, wherein the resin contained in the coating material for forming an adhesive layer is silicon-modified resin containing polysiloxane.

30. The coating material of a photocatalyst according to claim 26, wherein the resin contained in the coating material for forming an adhesive layer is silicon-modified resin containing colloidal silica.