Antiglare touch screen displays and other coated articles and methods of forming them

Abstract

Touch screen displays and other coated articles demonstrating antiglare properties are provided. A method of forming an antiglare coating on a substrate is also provided, and may be used to prepare the coated articles. The method comprises: (a) heating the substrate to a temperature of at least 100° F. (37.8° C.) to form a heated substrate; (b) applying a curable film-forming composition on at least one surface of the heated substrate to form a substrate coated with a sol-gel layer; and (c) subjecting the coated substrate to thermal conditions for a time sufficient to effect cure of the sol-gel layer. The curable film-forming composition comprises: (i) a silane; (ii) a mineral acid; and (iii) a solvent; wherein the weight ratio of mineral acid to silane is greater than 0.008:1 and the curable film-forming composition has a solids content of less than 10 percent by weight.

What is claimed is: 
     
         1 . A touch screen display demonstrating antiglare properties, wherein the touch screen display comprises a substrate and a cured coating formed by spray applying a curable film-forming composition to at least one surface of the substrate and curing of the curable film-forming composition, wherein the curable film-forming composition has a solids content of less than 10 percent by weight and comprises:
 (i) a tetraalkoxysilane comprising tetramethoxysilane and/or tetraethoxysilane present in an amount of less than 32 percent by weight, based on the total weight of the curable film-forming composition;   (ii) a mineral acid; and   (iii) a solvent;   wherein the weight ratio of mineral acid to tetraalkoxysilane is greater than 0.008:1 and less than 0.12:1; and wherein the cured coating demonstrates a surface roughness (R a ) of no more than 98 nm and a pencil hardness of at least 8 H, and wherein the coating is formed by a process comprising:   (a) heating the substrate to a temperature of 100 to 350° F. (37.8 to 176.7° C.) to form a heated substrate;   (b) spray applying the curable film-forming composition to at least one surface of the heated substrate to form a coated substrate; and   (c) subjecting the coated substrate to thermal conditions for a time sufficient to effect cure of the sol-gel layer.   
     
     
         2 . The touch screen display of  claim 1  wherein the coating comprises a cured inorganic network matrix. 
     
     
         3 . The touch screen display of  claim 2  wherein the curable film-forming composition comprises a sol-gel composition. 
     
     
         4 . The touch screen display of  claim 1 , wherein the solvent (iii) comprises at least one of an alcohol and a glycol ether. 
     
     
         5 . The touch screepn display of  claim 4 , wherein the solvent (iii) comprises isopropanol, propylene glycol methyl ether, propylene glycol methyl ether acetate, dipropylene glycol monomethyl ether, and/or diethylene glycol monobutyl ether. 
     
     
         6 . The touch screen display of  claim 1 , wherein the cured coating demonstrates a surface roughness (R a ) of no more than 80 nm. 
     
     
         7 . The touch screen display of  claim 6 , wherein the cured coating further demonstrates anti-sparkling. 
     
     
         8 . The touch screen display of  claim 1 , wherein step (a) comprises heating the substrate to a temperature of 200 to 350° F. (93.3 to 176.7° C.). 
     
     
         9 . The touch screen display of  claim 1 , where the surface roughness is demonstrated in microscopic topography of the cured coating as hills and valleys when a cross section of the coating is viewed, 
     
     
         10 . A coated article demonstrating antiglare properties, wherein the coated article is prepared by a process comprising:
 (a) heating a substrate to a temperature of 100 to 350° F. (37.8 to 176.7° C.) to form a heated substrate;   (b) spray applying a curable film-forming composition to at least one surface of the heated substrate to form a substrate coated with a sol-gel layer; wherein the curable film-forming composition has a solids content of less than 10 percent by weight and comprises:
 (i) a tetraalkoxysilane comprising tetramethoxysilane and/or tetraethoxysilane present in an amount of less than 32 percent by weight, based on the total weight of the curable film-forming composition; 
 (ii) a mineral acid; and 
 (iii) a solvent 
   wherein the weight ratio of mineral acid to tetraalkoxysilane is greater than 0.008:1 and less than 0.12:1; and   (c) subjecting the coated substrate to thermal conditions for a time sufficient to effect cure of the sol-gel layer and form a cured coating on the substrate, wherein the cured coating demonstrates a surface roughness (R a ) of no more than 98 nm.   
     
     
         11 . The coated article of  claim 10 , wherein said coated article comprises a glass optical article. 
     
     
         12 . The coated article of  claim 10 , wherein step (a) comprises heating the substrate to a temperature of 200 to 350° F. (93.3 to 176.7° C.). 
     
     
         13 . The coated article of  claim 10 , wherein the mineral acid (ii) comprises nitric acid. 
     
     
         14 . The coated article of  claim 10  wherein step (c) comprises heating the coated substrate to a temperature in the range of between 120° C. and 200° C. for at least 1 hour. 
     
     
         15 . The coated article of  claim 10  wherein the coated article demonstrates a gradient gloss across its surface. 
     
     
         16 . The coated article of  claim 10 , wherein the solvent (iii) comprises at least one of an alcohol and a glycol ether. 
     
     
         17 . The coated article of  claim 16 , wherein the solvent (iii) comprises isopropanol, propylene glycol methyl ether, propylene glycol methyl ether acetate, dipropylene glycol monomethyl ether, and/or diethylene glycol monobutyl ether. 
     
     
         18 . The coated article of  claim 10 , where the surface roughness is demonstrated in microscopic topography of the cured coating as hills and valleys when a cross section of the coating is viewed. 
     
     
         19 . The coated article of  claim 10 , wherein the cured coating demonstrates a surface roughness (R a ) of no more than 80 nm. 
     
     
         20 . The coated article of  claim 19 , wherein the cured coating further demonstrates anti-sparkling.