Coating compositions for glass substrates

Abstract

The present disclosure provides a coated glass substrate, first and second coating compositions, and a process for coating the substrate. The first composition includes a source of tin, a source of fluorine, a source of titanium, and a solvent. The second composition includes a source of tin, a source of fluorine, and a solvent, and can be free of titanium. The first composition is applied to the substrate under elevated temperatures, and a first or sub layer is formed on the substrate via pyrolysis. The second composition is then applied, to form a second or top layer over the sub layer.

1 . A coating composition, comprising:
 a source of tin, present in an amount of 15 wt % to 50 wt %, based on the weight of the composition;   a source of fluorine, present in an amount of 5 wt % to 30 wt %, based on the weight of the composition;   a source of titanium, present in an amount of 2 wt % to 15 wt %, based on the weight of the composition; and   a solvent.   
     
     
         2 . The composition of  claim 1 , wherein the composition consists of the source of tin, the source of fluorine, the source of titanium, and the solvent. 
     
     
         3 . The composition of  claim 1 , wherein the source of tin is a tin oxide, the source of fluorine is a carboxylic acid with a fluorine group, the source of titanium is a titanium oxide. 
     
     
         4 . The composition of  claim 1 , wherein the source of tin is dibutyl tin oxide, the source of fluorine is trifluoroacetic acid, the source of titanium is titanium isopropoxide, and the solvent is ethanol. 
     
     
         5 . A coating composition, comprising:
 a source of tin, present in an amount of 15 wt % to 50 wt %, based on the weight of the composition;   a source of fluorine, present in an amount of 2 wt % to 15 wt %, based on the weight of the composition; and   a solvent.   
     
     
         6 . The composition of  claim 5 , wherein the composition consists of the source of tin, the source of fluorine, and the solvent. 
     
     
         7 . The composition of  claim 5 , wherein the source of tin is a tin oxide, the source of fluorine is a carboxylic acid with a fluorine group, the source of titanium is a titanium oxide. 
     
     
         8 . The composition of  claim 5 , wherein the source of tin is monobutyl tin trichloride, the source of fluorine is hydrofluoric acid, and the solvent is water. 
     
     
         9 . The composition of  claim 5 , wherein the composition is free of titanium. 
     
     
         10 . A coated substrate, comprising, in consecutive arrangement:
 a glass or glass-ceramic substrate;   a first layer on at least one side of the substrate;   a second layer on top of the first layer,   wherein the first layer comprises a tin compound, a fluorine compound, and a titanium compound, and   wherein the second layer comprises a tin compound and a fluorine compound.   
     
     
         11 . The coated substrate of  claim 10 , wherein the second layer is free of titanium. 
     
     
         12 . The coated substrate of  claim 10 , wherein the first layer has a thickness of between 60 and 175 nanometers. 
     
     
         13 . The coated substrate of  claim 10 , wherein the second layer has a thickness of between 175 and 300 nanometers. 
     
     
         14 . The coated substrate of  claim 10 ,
 wherein the first layer has a first index of refraction and the second layer has a second index of refraction, and   wherein a ratio of the first index of refraction to the second index of refraction is between 1.05 and 1.35.   
     
     
         15 . The coated substrate of  claim 10 , further comprising an intermediate later between the glass substrate and the first layer. 
     
     
         16 . The coated substrate of  claim 15 , wherein the intermediate layer comprises a material selected from the group consisting of silicon dioxide, titanium dioxide, and tin dioxide. 
     
     
         17 . A process of preparing the coated substrate of  claim 10 , comprising the steps of:
 heating an uncoated glass or glass-ceramic substrate to a temperature between 1050 and 1200 F;   applying a first composition to at least one side of the uncoated substrate, wherein the first composition comprises a source of tin, a source of fluorine, a source of titanium, and a solvent;   applying a second composition on top of the first composition, wherein the second composition comprises a source of tin, a source of fluorine, and a solvent.   
     
     
         18 . The process of  claim 17 , wherein the second composition is free of titanium. 
     
     
         19 . The process of  claim 17 , wherein the source of tin in each of the first and second compositions is a tin oxide, the source of fluorine in each of the first and second compositions is a carboxylic acid with a fluorine group, and the source of titanium in the second composition is a titanium oxide. 
     
     
         20 . The process of  claim 17 , wherein the first composition comprises:
 the source of tin, present in an amount of 15 wt % to 50 wt %, based on the weight of the first composition;   the source of fluorine, present in an amount of 5 wt % to 30 wt %, based on the weight of the first composition;   a source of titanium, present in an amount of 2 wt % to 15 wt %, based on the weight of the first composition; and   a first solvent, and   
       wherein the second composition comprises:
 the source of tin, present in an amount of 15 wt % to 50 wt %, based on the weight of the second composition; 
 the source of fluorine, present in an amount of 2 wt % to 15 wt %, based on the weight of the second composition; and 
 a second solvent