Thermal barrier composition

Abstract

The thermal barrier composition of the present invention provides a glassy matrix comprising an alkoxy-functionalized siloxane and a functionally-terminated silane or siloxane, polymethylsilsesquioxane dissolved in a crosslinking agent, and optionally a filler and/or hollow glass microspheres.

That which is claimed is:  
     
         1 . A thermal barrier coating composition 
 (a) a glassy matrix comprising an alkoxy-functionalized siloxane and a functionally-terminated silane or siloxane;    (b) polymethylsilsesquioxane dissolved in a crosslinking agent;    (c) optionally, a filler, and    (d) optionally hollow glass microspheres.    
     
     
         2 . The thermal barrier coating composition according to  claim 1 , wherein the alkoxy-functionalized siloxane is selected from the group consisting of polydiethoxysiloxane, polydimethoxysiloxane, tetramethoxysiloxane and tetraethoxysiloxane and the functionally-terminated siloxane is an epoxy-functionalized polydiethoxysiloxane.  
     
     
         3 . The thermal barrier coating composition according to  claim 1 , wherein the crosslinking agent is titanium isopropoxide.  
     
     
         4 . The thermal barrier coating compositiong according to  claim 1 , wherein the filler is selected from the group consisting of fumed silica, mica, kaolin, bentonite, talc, zinc oxides, iron oxides and pigments.  
     
     
         5 . The thermal barrier coating composition according to  claim 1 , wherein the glassy matrix is crosslinked using a titanium or tin catalyst.  
     
     
         6 . The thermal barrier coating composition according to  claim 5 , wherein the titanium or tin catalyst is selected from the group consisting of titanium methoxide, titanium ethoxide, titanium isopropoxide, titanium propoxide, titanium butoxide, titanium diisopropoxide (bis 2,4-pentanedionate), titanium diisopropoxide bis(ethylacetoacetao) titanium ethylhexoxide, dibutyl tin diacetate, dibutyltin laurate, dimethyl tin dineodecanoate, dioctyl dilauryl tin, and dibutyl butoxy chlorotin, and mixtures thereof.  
     
     
         7 . The thermal barrier coating composition according to  claim 1 , further comprising an anti-corrosion agent.  
     
     
         8 . A substrate coated with a thermal barrier composition comprising a glassy matrix comprising an alkoxy-functionalized siloxane and a functionally-terminated silane or siloxane, polymethylsilsesquioxane dissolved in a crosslinking agent, optionally, a filler, and optionally hollow glass microspheres.  
     
     
         9 . The substrate according to  claim 8 , wherein the substrate is selected from the group consisting of steel, stainless steel, titanium, aluminum, magnesium and zinc.  
     
     
         10 . The substrate according to  claim 8 , wherein the alkoxy-functionalized siloxane is selected from the group consisting of polydiethoxysiloxane, polydimethoxysiloxane, tetramethoxysilane and tetraethoxysilane and the functionally-terminated siloxane is an epoxy-functionalized polydiethoxysiloxane.  
     
     
         11 . The substrate according to  claim 8 , wherein the crosslinking agent is titanium isopropoxide.  
     
     
         12 . The substrate according to  claim 8 , wherein the filler is selected from the group consisting of fumed silica, mica, kaolin, bentonite, talc, zinc oxides, iron oxides, and pigments.  
     
     
         13 . The substrate according to  claim 8 , wherein the glassy matrix is crosslinked using a titanium or tin catalyst.  
     
     
         14 . The substrate according to  claim 13 , wherein the titanium or tin catalyst is selected from the group consisting of titanium methoxide, titanium ethoxide, titanium isopropoxide, titanium propoxide, titanium butoxide, titanium diisopropoxide (bis 2,4-pentanedionate), titanium diisopropoxide bis(ethylacetoacetao) titanium ethylhexoxide, dibutyl tin diacetate, dibutyltin laurate, dimethyl tin dineodecanoate, dioctyl dilauryl tin, and dibutyl butoxy chlorotin, and mixtures thereof.  
     
     
         15 . The substrate according to  claim 8 , further comprising an anti-corrosion agent.  
     
     
         16 . A method of forming a thermal barrier composition comprising the steps of 
 (a) dissolving polymethylsilsesquioxane in a crosslinking agent;    (b) mixing a glass matrix comprising an alkoxy-functionalized siloxane and a functionally-terminated silane with a tin or titanium catalyst to terminate the silanol groups on the end of the siloxane; and    (c) mixing (a) and (b) together.    
     
     
         17 . The method according to  claim 16 , including adding filler or glass microspheres to the dissolved polymethylsilsesquioxane of step (a) or the mixture of step (c).  
     
     
         18 . The method according to  claim 16 , wherein the alkoxy-functionalized siloxane is selected from the group consisting of polydiethoxysiloxane, polydimethoxysiloxane, tetramethoxysilane and tetraethoxysilane and the functionally-terminated siloxane is an epoxy-functionalized polydiethoxysiloxane.  
     
     
         19 . The method according to  claim 16 , wherein the crosslinking agent is titanium isopropoxide.  
     
     
         20 . The method according to  claim 16 , wherein the filler selected from the group consisting of fumed silica, mica, kaolin, bentonite, talc, zinc oxides, zinc phosphates, iron oxides and pigments.  
     
     
         21 . The method according to  claim 16 , wherein the titanium or tin catalyst is selected from the group consisting of titanium methoxide, titanium ethoxide, titanium isopropoxide, titanium propoxide, titanium butoxide, titanium diisopropoxide (bis 2,4-pentanedionate), titanium diisopropoxide bis(ethylacetoacetao) titanium ethylhexoxide, dibutyl tin diacetate, dibutyltin laurate, dimethyl tin dineodecanoate, dioctyl dilauryl tin, and dibutyl butoxy chlorotin, and mixtures thereof.  
     
     
         22 . The method according to  claim 16 , further comprising an anti-corrosion agent.