Coated substrate with high reflectance

Abstract

A transparent coated substrate with rather high reflectance, especially for use as in exterior glazing panels for buildings or automotives, is provided by a substrate carrying a coating stack comprising a pyrolytically-formed main layer containing oxide of tin and an outer layer comprising TiO 2 , whereby the so-coated substrate has a reflectance (RL) of more than 10%. The coated substrate advantageously shows photocatalytic and hydrophilic properties.

1 - 26 . (canceled)  
     
     
         27 . A transparent substrate carrying a coating stack, the coating stack comprising, in order from the substrate: 
 an undercoat layer,    a pyrolytically-formed main coating layer comprising oxide of tin, and    an outer reflective layer which has a refractive index ranging from 2.0 to 2.8,    so that the coated transparent substrate has a reflectance (RL) of more than 10%.    
     
     
         28 . The coated transparent substrate as claimed in claim  1 , wherein the main coating layer has a geometric thickness of at least 250 nm.  
     
     
         29 . The coated transparent substrate as claimed in claim  1 , wherein the outer reflective layer has a geometric thickness ranging from 30 to 150 nm.  
     
     
         30 . The coated transparent substrate as claimed in claim  1 , wherein the outer reflective layer contains at least one oxide selected from the group consisting of nickel, tin, titanium, zinc, and zirconium.  
     
     
         31 . The coated transparent substrate as claimed in claim  1 , wherein the outer reflective layer comprises titanium oxide.  
     
     
         32 . The coated transparent substrate as claimed in claim  1 , wherein the outer reflective layer comprises titanium oxide and tin oxide.  
     
     
         33 . The coated transparent substrate as claimed in claim  1 , wherein the main coating layer further comprises antimony.  
     
     
         34 . The coated transparent substrate as claimed in claim  1 , wherein the main coating layer further comprises antimony and an additive which is at least one element selected from the group consisting of aluminum, chromium, cobalt, iron, manganese, magnesium, nickel, titanium, vanadium, zinc, and zircomum.  
     
     
         35 . The coated transparent substrate as claimed in claim  1 , wherein the undercoat layer imparts to the coated transparent substrate a more neutral tint in reflection.  
     
     
         36 . The coated transparent substrate as claimed in claim  1 , wherein the undercoat layer comprises at least one oxide of silicon.  
     
     
         37 . The coated transparent substrate as claimed in claim  1 , wherein the undercoat layer comprises alumina.  
     
     
         38 . The coated transparent substrate as claimed in claim  1 , wherein the undercoat layer has a geometric thickness which ranges from 60 to 75 nm.  
     
     
         39 . The coated transparent substrate as claimed in claim  1 , wherein the coating stack further comprises an intermediate layer positioned between the main coating layer and the outer reflective layer.  
     
     
         40 . The coated transparent substrate as claimed in claim  13 , wherein the intermediate layer comprises one of aluminum oxide or silicon oxide.  
     
     
         41 . The coated transparent substrate as claimed in claim  1 , having a luminous transmittance (TL) of at least 60%.  
     
     
         42 . The coated transparent substrate as claimed in claim  1 , having a reflectance (RL) of at least 15%.  
     
     
         43 . The coated transparent substrate as claimed in claim  1 , having a selectivity (TL/FS) greater than 1.00.  
     
     
         44 . The coated transparent substrate as claimed in claim  1 , having a colour in reflection defined by a Hunter value a between 0 and −4.0.  
     
     
         45 . The coated transparent substrate as claimed in claim  1 , having a colour in reflection defined by a Hunter value b between −5.3 and −1.5.  
     
     
         46 . The coated transparent substrate as claimed in claim  1 , having a colour in reflection defined by a Hunter value a between 0 and −2 and a Hunter value b between −4 and −2.  
     
     
         47 . The coated transparent substrate as claimed in claim  1 , having a purity in reflection of not greater than 14.8%.  
     
     
         48 . The coated transparent substrate as claimed in claim  1 , having a purity in reflection of less than 10%.  
     
     
         49 . A glazing panel, comprising a coated transparent substrate as claimed in claim  1 .  
     
     
         50 . The glazing panel as claimed in claim  23 , which has a structure of a glazing panel for a building.  
     
     
         51 . The glazing panel as claimed in claim  23 , which has a structure of a window for a vehicle.  
     
     
         52 . A transparent substrate carrying a coating stack, the coating stack comprising, in order from the substrate: 
 an undercoat layer imparting to the coated transparent substrate a more neutral tint in reflection,    a pyrolytically-formed main coating layer comprising oxide of tin, and    an outer reflective layer having a geometric thickness ranging from 30 to 150 nm and a refractive index ranging from 2.0 to 2.8,    so that the coated transparent substrate has a reflectance (RL) of more than 10%.    
     
     
         53 . The coated transparent substrate as claimed in claim  26 , wherein the outer reflective layer consists essentially of titanium oxide.  
     
     
         54 . The coated transparent substrate as claimed in  claim 27 , having a colour in reflection defined by a Hunter value a between 0 and −3.7 and a Hunter value b between −5.3 and −2 and having a purity in reflection not greater than 10.7%.  
     
     
         55 . A transparent substrate carrying a coating stack, the coating stack comprising, in order from the substrate: 
 an undercoat layer,    a pyrolytically-formed main coating layer comprising oxide of tin, and    an outer reflective layer having a geometric thickness ranging from 30 to 150 nm and a refractive index ranging from 2.0 to 2.8,    so that the coated transparent substrate has a reflectance (RL) of more than 10%, has a colour in reflection defined by a Hunter value a between 0 and −3.7 and a Hunter value b between −5.3 and −2 and has a purity in reflection not greater than 10.7%.    
     
     
         56 . The coated transparent substrate as claimed in  claim 29 , wherein the outer reflective layer consists essentially of titanium oxide.