COATING COMPOSITIONS FOR GLASS SUBSTRATES
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