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

Patent metadata

Field	Value
Publication number	US-10010869-B2
Application number	US-201414200352-A
Country	US
Kind code	B2
Filing date	Mar 7, 2014
Priority date	Jun 1, 2012
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

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

What is claimed is:

1. An aqueous dispersion, comprising:
visible-light responsive photocatalytic composite microparticles containing tungsten oxide microparticles, zirconium oxide microparticles each having a crystal structure, and at least one metal element selected from the group consisting of nickel, titanium, manganese, iron, palladium, platinum, ruthenium, copper, silver, aluminum, and cerium; and
an aqueous dispersion medium in which the photocatalytic composite microparticles are dispersed;
wherein the photocatalytic composite microparticles contain zirconium oxide microparticles in a range of 10 mass % to 200 mass % with respect to the tungsten oxide microparticles, the metal element in a range of 0.005 mass % to 2 mass % with respect to the tungsten oxide microparticles, and the balance being tungsten oxide microparticles;
wherein a D50 particle size of the tungsten oxide microparticles and zirconium oxide microparticles, individually, in a particle size distribution of the photocatalytic composite microparticles is in a range of 50 nm to 1 pm;
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 5 to 7.5.

2. The aqueous dispersion according to claim 1 ,
wherein the photocatalytic composite microparticles contain zirconium oxide microparticles in a range of 10 mass % to 150 mass % with respect to the tungsten oxide microparticles.

3. The aqueous dispersion according to claim 1 ,
wherein a ratio of the atomicity of zirconium to the atomicity of tungsten in the photocatalytic composite microparticles is in a range of 10% to 400%.

4. The aqueous dispersion according to claim 1 ,
wherein the photocatalytic composite microparticles are dispersed in the aqueous dispersion medium in a range of 0.001 mass % to 50 mass %.

5. The aqueous dispersion according to claim 1 ,
wherein the metal element is contained in the photocatalytic composite microparticles in at least one form selected from the group consisting of an element substance of the metal element, a compound of the metal element, and a complex compound of the metal element and tungsten or zirconium.

6. A coating material, comprising:
the aqueous dispersion according to claim 1 ; and
at least one binder component selected from the group consisting of an inorganic binder and an organic binder.

7. A photocatalytic film, configured to be formed by applying the aqueous dispersion according to claim 1 on a base material.

8. A photocatalytic film, configured to be formed by applying the coating material according to claim 6 on a base material.

9. A product comprising the photocatalytic film according to claim 7 .

10. A product comprising the photocatalytic film according to claim 8 .

11. The aqueous dispersion according to claim 1 , wherein each of the zirconium oxide micro particles has a monoclinic crystal structure.

12. The aqueous dispersion according to claim 1 , wherein the aqueous dispersion has a color whose a* is 10 or less, b* is −5 or more, and L* is 50 or more when the color of the aqueous dispersion is expressed by an L*a*b* color system.

13. The aqueous dispersion according to claim 1 , wherein the pH of the aqueous dispersion is in a range of 6 to 7.

Assignees

• Toshiba Kk
• Toshiba Materials Co Ltd

Inventors

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

Classifications

• B01J21/063

  Titanium; Oxides or hydroxides thereof · CPC title

• B01J37/0221

  of particles · CPC title

• C09D1/00

  Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances · CPC title

• B01J23/8993

  with chromium, molybdenum or tungsten · CPC title

• B01J23/30 Primary

  Tungsten · CPC title