Low-emissivity coating and functional construction material for window and door including same
Disclosed is a multi-layered low-emissivity coating sequentially comprising: a Ti-based oxide layer, a composite metallic oxide layer of zinc and aluminum, a low-emissivity protective metal layer, and a low-emissivity layer.
1. A multi-layered low-emissivity coating having a bottom surface and a top surface opposite to the bottom surface, the multi-layered low-emissivity coating sequentially comprising, from the bottom surface to the top surface:
a Ti-based oxide layer;
a composite metallic oxide layer of zinc and aluminum;
a low-emissivity protective metal layer; and
a low-emissivity layer,
wherein the composite metallic oxide layer of zinc and aluminum comprises a composite metallic oxide of zinc and aluminum represented by ZnAlO x , where 0.9≦x≦1.1.
2. The multi-layered low-emissivity coating of claim 1 , wherein the composite metallic oxide layer of zinc and aluminum has a thickness of about 2 nm to about 10 nm.
3. The multi-layered low-emissivity coating of claim 1 , wherein the low-emissivity layer has an emissivity of about 0.01 to about 0.3.
4. The multi-layered low-emissivity coating of claim 1 , wherein the low-emissivity layer comprises at least one selected from the group consisting of Ag, Au, Cu, Al, Pt, ion-doped metal oxide, and combinations thereof.
5. The multi-layered low-emissivity coating of claim 4 , wherein the ion-doped metal oxide include indium tin oxide, fluorine-doped tin oxide, Al-doped zinc oxide and gallium zinc oxide.
6. The multi-layered low-emissivity coating of claim 1 , wherein the low-emissivity layer has a thickness of 5 nm to 25 nm.
7. The multi-layered low-emissivity coating of claim 1 , wherein the low-emissivity protective metal layer has an extinction coefficient in a visible light region of about 1.5 to about 4.
8. The multi-layered low-emissivity coating of claim 1 , wherein the low-emissivity protective metal layer comprises at least one selected from the group consisting of Ni, Cr, alloys of Ni and Cr, Ti, and combinations thereof.
9. The multi-layered low-emissivity coating of claim 1 , further comprising an outermost dielectric layer having a Si-based composite metal nitride on at least one of the bottom surface or the top surface of the low-emissivity coating.
10. The multi-layered low-emissivity coating of claim 9 , wherein the Si-based composite metal nitride is a composite represented by SiAlN x , where 1.2≦x≦1.5.
11. The multi-layered low-emissivity coating of claim 1 , wherein the Si-based composite metal nitride comprises at least one selected from the group consisting of Al, Ti, Co, and combinations thereof.
12. The multi-layered low-emissivity coating of claim 1 , wherein the Ti-based oxide layer comprises a composite represented by TiO x , where 1.8≦x≦2.2.
13. The multi-layered low-emissivity coating of claim 1 , wherein the low-emissivity layer has a sheet resistance of 0.78 Ω/sq to 6.42 Ω/sq.
14. The multi-layered low-emissivity coating of claim 1 , wherein the low-emissivity layer has an emissivity of about 0.01 to about 0.08.
15. A multi-layered low-emissivity coating having a bottom surface and a top surface opposite to the bottom surface, the multi-layered low-emissivity coating comprising, from the bottom surface to the top surface:
a first outermost dielectric layer;
a Ti-based oxide layer;
a composite metallic oxide layer of zinc and aluminum;
a first low-emissivity protective metal layer;
a low-emissivity layer;
a second low-emissivity protective metal layer; and
a second outermost dielectric layer;
wherein
the first outermost dielectric layer and the second outermost dielectric layer comprise a Si-based composite metal nitride, and
the composite metallic oxide layer of zinc and aluminum comprises a composite metallic oxide of zinc and aluminum represented by ZnAlO x , where 0.9≦x≦1.1.
16. A functional construction material for at least one of a window or a door, comprising: a transparent substrate; and the low-emissivity coating according to claim 1 coated on the transparent substrate.
17. The functional construction material for at least one of a window or a door of claim 16 , wherein the low-emissivity coating is laminated in such a way that the Ti-based oxide layer is arranged closer to the transparent substrate than the low-emissivity layer.
18. The functional construction material for at least one of a window or a door of claim 16 , wherein the transparent substrate has a visible light transmittance in the range of about 90% to about 100%.
19. The functional construction material for at least one of a window or a door of claim 16 , wherein the transparent substrate is a glass or transparent plastic substrate.
20. The functional construction material for at least one of a window or a door of claim 16 , wherein the transparent substrate has a thickness of 2 mm to 12 mm.