Near infrared reflecting coatings on glass
Multi-layer solar control films composed of metal oxide, oxynitride, carbide, and/or oxycarbide layers are deposited on a substrate by atmospheric pressure chemical vapor deposition (APCVD). The film layers have alternating high/low refractive index. The coated substrate reflects near infrared (NIR) radiation, while transmitting a high level of visible radiation.
1 . A process for producing a coated substrate which reflects the near infrared portion of the solar spectrum comprising depositing multiple film layers of metal-containing oxide, oxynitride, carbide and/or oxycarbide compounds onto a substrate by atmospheric pressure chemical vapor deposition, wherein said coated substrate reflects at least 17 percent of the near infrared radiation over the range of 750-2500 nm.
2 . The process of claim 1 wherein the substrate is glass.
3 . The process of claim 1 wherein said multilayer film comprises from 2 to 5 layers.
4 . The process of claim 3 wherein said multilayer film comprises 3 layers.
5 . The process of claim 1 wherein said films are comprised of metal oxides, metal carbides, metal oxynitrides, or oxycarbides of Si, Ti, Sn, Al, Ta, Zr, or Zn; or mixtures thereof.
6 . The process of claim 5 , wherein all film layers comprise metal oxides.
7 . The process of claim 1 wherein at least one layer of the film comprises antimony-doped tin oxide.
8 . The process of claim 1 wherein said coated substrate has a visible transmission of greater than about 70 percent, and visible reflectance of less than about 20 percent.
9 . The process of claim 1 wherein each film layer has a refractive index of between 1.46 to 2.6.
10 . The process of claim 1 wherein each film layer has a thickness of from 100 Å to 2000 Å.
11 . The process of claim 1 wherein the deposition rate is up to 600 Å/sec.
12 . The process of claim 11 wherein the deposition rate is from 400 to 500 Å.
13 . A coated substrate comprising a substrate having directly deposited thereon multiple layers of metal oxide, oxynitride, carbide and/or oxycarbide films, wherein said coated substrate reflects at least 17 percent of the near infrared radiation over the range of 750-2500 nm, and has a visible transmission of greater than 70 percent and a visible reflectance of least than 20 percent.
14 . The coated substrate of claim 13 wherein said multiple film layers are deposited by atmospheric pressure chemical vapor deposition.
15 . The coated substrate of claim 13 wherein said multiple film layers comprise from 2 to 5 layers.