Aqueous dispersion and coating material using the same, and photocatalytic film and product

Patent metadata

Field	Value
Publication number	US-10335771-B2
Application number	US-201816001167-A
Country	US
Kind code	B2
Filing date	Jun 6, 2018
Priority date	Jun 1, 2012
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

An aqueous dispersion of an embodiment includes visible-light responsive photocatalytic composite microparticles containing tungsten oxide and zirconium oxide, and an aqueous dispersion medium in which the photocatalytic composite microparticles are dispersed. In the photocatalytic composite microparticles, a ratio of a mass of the zirconium oxide to a mass of the tungsten oxide is in a range of from 0.05% to 200%, and a D50 particle size in particle size distribution is in a range of from 20 nm to 10 μm. The aqueous dispersion has pH in a range of from 1 to 9.

First claim

The invention claimed is:

1. A method for manufacturing a photocatalytic film, comprising:
preparing an aqueous dispersion including a visible-light responsive photocatalytic composite microparticles containing tungsten oxide microparticles and zirconium oxide microparticles, and an aqueous dispersion medium in which the photocatalytic composite microparticles are dispersed; and
applying the aqueous dispersion on a base material to form a photocatalytic film having a film thickness in a range of 2 to 1000 nm,
wherein the photocatalytic composite microparticles are dispersed in the aqueous dispersion medium in a range of 0.001 to 50 mass %;
wherein a D50 particle size in a particle size distribution of the photocatalytic composite microparticles is in a range of 20 nm to 10 μm;
wherein the zirconium oxide microparticles have rod-shaped primary particles, and a ratio of an average major axis of the rod-shaped primary particles to an average primary particle size of the tungsten oxide microparticles is in a range of 0.05 to 20; and
wherein a pH of the aqueous dispersion is in a range of 1 to 9.

2. The method according to claim 1 ,
wherein the photocatalytic composite microparticles contain at least one metal element selected from the group consisting of nickel, titanium, manganese, iron, palladium, platinum, ruthenium, copper, silver, aluminum, and cerium; and
wherein the photocatalytic composite microparticles contain the zirconium oxide microparticles in a range of 10 to 200 mass % with respect to the tungsten oxide microparticles, the metal element in a range of 0.005 to 2 mass % with respect to the tungsten oxide microparticles, and the balance being the tungsten oxide microparticles.

3. The method according to claim 1 ,
wherein the D50 particle size of the photocatalytic composite microparticles is in a range of 50 nm to 1 μm; and
wherein the pH of the aqueous dispersion is in a range of 5 to 7.5.

4. The method according to claim 1 ,
wherein a D90 particle size in a particle size distribution of the photocatalytic composite microparticles is in a range of 0.05 to 10 μm.

5. The method according to claim 1 ,
wherein the aqueous dispersion contains at least one selected from the group consisting of activated carbon, zeolite, and porous ceramics.

6. The method according to claim 1 ,
wherein the base material is made of glass, ceramics, resin, metal, paper, fiber, or wood.

7. The method according to claim 1 ,
wherein the photocatalytic film is formed on a surface of a building material, an interior material, a home electric appliance, or a filter used in a home electric appliance.

8. A method for manufacturing a photocatalytic film, comprising:
preparing a coating material comprising: an aqueous dispersion including a visible-light responsive photocatalytic composite microparticles containing tungsten oxide microparticles and zirconium oxide microparticles, and an aqueous dispersion medium in which the photocatalytic composite microparticles are dispersed; and a binder component comprising at least one selected from the group consisting of an inorganic binder and an organic binder; and
applying the coating material on a base material to form a photocatalytic film having a film thickness in a range of 2 to 1000 nm,
wherein the photocatalytic composite microparticles are dispersed in the aqueous dispersion medium in a range of 0.001 to 50 mass %;
wherein a D50 particle size in a particle size distribution of the photocatalytic composite microparticles is in a range of 20 nm to 10 μm;
wherein the zirconium oxide microparticles have rod-shaped primary particles, and a ratio of an average major axis of the rod-shaped primary particles to an average primary particle size of the tungsten oxide microparticles is in a range of 0.05 to 20; and
wherein a pH of the aqueous dispersion is in a range of 1 to 9.

9. The method according to claim 8 ,
wherein the photocatalytic composite microparticles contain at least one metal element selected from the group consisting of nickel, titanium, manganese, iron, palladium, platinum, ruthenium, copper, silver, aluminum, and cerium; and
wherein the photocatalytic composite microparticles contain the zirconium oxide microparticles in a range of 10 to 200 mass % with respect to the tungsten oxide microparticles, the metal element in a range of 0.005 to 2 mass % with respect to the tungsten oxide microparticles, and the balance being the tungsten oxide microparticles.

10. The method according to claim 8 ,
wherein the D50 particle size of the photocatalytic composite microparticles is in a range of 50 nm to 1 μm; and
wherein the pH of the aqueous dispersion is in a range of 5 to 7.5.

11. The method according to claim 8 ,
wherein a D90 particle size in a particle size distribution of the photocatalytic composite microparticles is in a range of 0.05 to 10 μm.

12. The method according to claim 8 ,
wherein the coating material contains at least one selected from the group consisting of activated carbon, zeolite, and porous ceramics.

13. The method according to claim 8 ,
wherein the base material is made of glass, ceramics, resin, metal, paper, fiber, or wood.

14. The method according to claim 8 ,
wherein a content of the binder component in the coating material is in a range of from 5 to 95 mass %.

15. The method according to claim 8 ,
wherein the inorganic binder comprises at least one selected from the group consisting of a product obtained through decomposition of a hydrolytic silicon compound, an organopolysiloxane compound, a polycondensate of the organopolysiloxane compound, silica, water glass, phosphate, metal oxide, cement, gypsum, lime, and frit.

16. The method according to claim 8 ,
wherein the organic binder comprises at least one selected from the group consisting of fluorine-based resin, silicone resin, acrylic resin, epoxy resin, polyether resin, melamine resin, urethane resin, and alkyd resin.

17. The method according to claim 8 ,
wherein the photocatalytic film is formed on a surface of a building material, an interior material, a home electric appliance, or a filter used in a home electric appliance.

Assignees

• Toshiba Kk
• Toshiba Materials Co Ltd

Inventors

• Fukushi Daisuke
• Kusaka Takao
• Sato Akira
• Nakano Kayo
• Nitsuta Akihisa
• Inui Yukiko
• Oota Hiroyasu

Classifications

• B01J23/30 Primary

  Tungsten · CPC title

• B01J23/8993

  with chromium, molybdenum or tungsten · CPC title

• B01J21/063

  Titanium; Oxides or hydroxides thereof · CPC title

• B01J23/888

  Tungsten · CPC title

• B01J37/0221

  of particles · CPC title