Phoyocatalytic coating

Patent metadata

Field	Value
Publication number	US-2016361706-A1
Application number	US-201615248124-A
Country	US
Kind code	A1
Filing date	Aug 26, 2016
Priority date	Dec 22, 2006
Publication date	Dec 15, 2016
Grant date	—

Abstract

In one aspect, the present invention is directed to a coating composition. The coating composition comprises photocatalytic particles and an alkali metal silicate binder comprising an alkoxysilane. In another aspect, the present invention is directed to a coated article. The coated article has a photocatalytic coating with improved durability on its external surface that is formed from the aforesaid coating composition.

First claim

1 . A method of making a coated article, comprising:
providing an article having an external surface, providing a composition comprising between 30 weight % and 60 weight % photocatalytic particles and an alkali metal silicate binder, wherein the alkali metal silicate binder further comprises a tetraethoxysilane, and wherein the composition comprises between 32 weight % and 60 weight % tetraethoxysilane, depositing the composition onto the article, and heating the deposited article to form a coating thereon.

2 . The method of claim 1 , wherein the article is a roofing granule.

3 . The method of claim 1 , wherein the article is a tile.

4 . The method of claim 1 , wherein the photocatalytic particles comprise TiO 2 , ZnO, WO 3 , SnO 2 , CaTiO 3 , Fe 2 O 3 , MoO 3 , Nb 2 O 5 , Ti x Zr (1-x) O 2 , SiC, SrTiO 3 , CdS, GaP, InP, GaAs, BaTiO 3 , KNbO 3 , Ta 2 O 5 , Bi 2 O 3 , NiO, Cu 2 O, SiO 2 , MoS 2 , InPb, RuO 2 , CeO 2 , Ti(OH) 4 , or combinations thereof.

5 . The method of claim 1 , wherein the photocatalytic particles comprise crystalline anatase TiO 2 , crystalline rutile TiO 2 , crystalline ZnO, or combinations thereof

6 . The method of claim 1 , wherein the photocatalytic particles are doped with C, N, S, F, Pt, Pd, Au, Ag, Os, Rh, RuO 2 , Nb, Cu, Sn, Ni, Fe, or combinations thereof

7 . The method of claim 1 , wherein the alkoxysilane comprises methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, isobutyltrimethoxysilane, pentyltriethoxysilane, octyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetrakis(s-butoxy)silane, tetrakis( 2 -ethyl-butoxy)silane, tetrakis( 2 -ethyl-hexoxy)silane, tetrakis( 2 -methoxy-ethoxy)silane, tetraphenoxysilane, hexaethoxydisiloxane, tetracetoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, and di-t-butoxydiacetoxysilane, or combinations thereof.

8 . The method of claim 1 , wherein the alkoxysilane comprises a tetraethoxysilane.

9 . The method of claim 1 , wherein the durability of the coating measured using the Coating Durability Test is more than about 70%.

10 . The method of claim 1 , wherein the alkali metal silicate binder comprises lithium silicate, sodium silicate, potassium silicate, or combinations thereof.

11 . The method of claim 1 , wherein the alkali metal silicate binder further comprises a pigment.

12 . A method of making a coated roofing granule, comprising:
providing a roofing granule having an external surface, providing a composition comprising between 30 weight % and 60 weight %_photocatalytic TiO 2 particles and an alkali metal silicate binder, wherein the alkali metal silicate binder further comprises a tetraethoxysilane and wherein the composition comprises between 32 weight % and 60 weight % tetraethoxysilane, depositing the composition onto the roofing granule, and heating the deposited roofing granule to form a coating thereon, wherein the durability of the coating measured using the Coating Durability Test is more than about 70%.

Assignees

• 3M Innovative Properties Co

Inventors

• Bai Feng
• Gould Rachael A T
• Anderson Mark T

Classifications

• B01D53/8678

  Removing components of undefined structure · CPC title

• E04F13/00

  Coverings or linings, e.g. for walls or ceilings (flooring E04F15/00; decoration of surfaces, mosaic work B44, e.g. paper-hanging B44C7/00; made of webs, e.g. of fabrics or wallpaper {, as such, or their manufacturing} D03D, D04G, D04H, D06N, D21H; construction of {false} ceilings E04B9/00; roofings or similar water-tight coverings against precipitation E04D) · CPC title

• B01J21/063

  Titanium; Oxides or hydroxides thereof · CPC title

• C08K3/013

  Fillers, pigments or reinforcing additives · CPC title

• C09D183/04

  Polysiloxanes · CPC title