Coated article

Abstract

A new article is disclosed. The article includes a a functional coating with a first emissivity value over at least a portion of a ply and a protective coating comprising 35 wt. % to 100 wt. % alumina and 0 wt. % to 65 wt. % silica and having a second emissivity value over at least a portion of the functional coating. The coating stack on the article has an emissivity value greater than the emissivity value of the functional coating.

1 . A method of making a laminated article, comprising the steps of: 
 providing a first substrate having a major surface;    applying a functional coating having an emissivity value over at least a portion of the first substrate major surface;    applying a protective coating comprising 35 wt. % to 100 wt. % alumina and 0 wt. % to 65 wt. % silica over at least a portion of the functional coating to form a coating stack having an emissivity value greater than the emissivity value of the functional coating;    providing a second substrate;    heating the first and second substrates to desired shapes; and    laminating the first and second substrates together with an interlayer, with the protective coating facing the interlayer.    
   
   
       2 . The method of  claim 1 , wherein the protective coating has a refractive index of less than 2.  
   
   
       3 . The method of  claim 1 , wherein the protective coating has a refractive index about the same as the refractive index of the second substrate.  
   
   
       4 . The method of  claim 1 , wherein the protective coating increases the emissivity of the coating stack to be in the range of 0.3 to 0.9.  
   
   
       5 . The method of  claim 1 , wherein the protective coating increases the emissivity of the coating stack to greater than or equal to 0.5.  
   
   
       6 . The method of  claim 1 , including adding a sufficient protective coating such that the emissivity of the coating stack is within 0.2 of the emissivity of the first substrate.  
   
   
       7 . A method of making a coated article, comprising the steps of: 
 providing a coating having a predetermined infrared reflectance and a predetermined emissivity; and    altering the coating such that the emissivity increases but the infrared reflectance remains substantially the same.    
   
   
       8 . A laminated article, comprising: 
 a first ply having a first major surface;    a functional coating over at least a portion of the first major surface and having an emissivity value;    a protective coating comprising 35 wt. % to 100 wt. % alumina and 0 wt. % to 65 wt. % silica over at least a portion of the functional coating to form a coating stack having an emissivity, the protective coating configured to increase the emissivity of the coating stack over the emissivity of the functional coating alone;    a second ply; and    an interlayer located between the first and second plies, with the protective coating facing the interlayer.    
   
   
       9 . The article of  claim 8 , wherein the first and second plies are selected from glass, plastic, and ceramic material.  
   
   
       10 . The article of  claim 8 , wherein the protective coating has a refractive index in the range of 1.5 to 2.0.  
   
   
       11 . The article of  claim 8 , wherein the protective coating increases the emissivity of the coating stack to be in the range of 0.3 to 0.9.  
   
   
       12 . An article, comprising: 
 a substrate;    a functional coating over at least a portion of the substrate; and    a protective coating comprising 35 wt. % to 100 wt. % alumina and 0 wt. % to 65 wt. % silica over the functional coating, wherein the functional coating and the protective coating define a coating stack and the protective coating provides the coating stack with an emissivity higher than the emissivity of the functional coating alone.    
   
   
       13 . The article as claimed in  claim 12 , wherein the substrate is selected from glass, plastic, and ceramic.  
   
   
       14 . The article as claimed in  claim 12 , wherein the article is an automotive transparency.  
   
   
       15 . The article as claimed in  claim 12 , wherein the substrate has a thickness of 2 mm to 20 mm.  
   
   
       16 . The article of in  claim 12 , wherein the functional coating has an emissivity of 0.1 or less.  
   
   
       17 . The article of  claim 12 , wherein the protective coating increases the emissivity of the coating stack by at least a factor of two with respect to the emissivity of the functional coating.  
   
   
       18 . The article of  claim 12 , wherein the protective coating increases the emissivity of the coating stack by a factor in the range of 2 to 20 compared to the emissivity of the functional coating.  
   
   
       19 . The article as claimed in  claim 12 , wherein the functional coating has an emissivity of 0.1 or less and the coating stack has an emissivity of 0.5 or more.  
   
   
       20 . The article as claimed in  claim 12 , wherein the emissivity of the coating stack is 0.5 to 0.8.  
   
   
       21 . The article as claimed in  claim 12 , wherein the protective coating has a thickness of greater than 1 micron.  
   
   
       22 . The article as claimed in  claim 12 , wherein the protective coating has a thickness of less than 5 microns.  
   
   
       23 . The article as claimed in  claim 12 , wherein the protective coating comprises 86 wt. % to 90 wt. % alumina and 10 wt. % to 14 wt. % silica.  
   
   
       24 . The article as claimed in  claim 12 , wherein the protective coating is solar absorbing in at least one of the UV, IR, or visible regions of the electromagnetic spectrum.  
   
   
       25 . A monolithic automotive transparency, comprising: 
 a glass substrate;    a functional coating over at least a portion of the glass substrate; and    a protective coating over the functional coating to form a coating stack, the protective coating comprising 35 wt. % to 100 wt. % alumina and 0 wt. % to 65 wt. % silica having a thickness in the range of 1 micron to 5 microns and providing the coating stack with an emissivity of at least 0.5.    
   
   
       26 . The transparency as claimed in  claim 25 , wherein the protective coating comprises 70 wt. % to 90 wt. % alumina and 10 wt. % to 30 wt. % silica.