Composition with film forming alkylsilsesquioxane polymer and method for applying hydrophobic films to surfaces

Abstract

A solid composition having a solid state film forming substance mixed with an inert carrier. The composition is heated in a vacuum chamber to evaporate the film forming substance by sublimation to form a molecular beam of amphiphilic molecules which settle on a substrate surface within the chamber and bond thereto while self-assembling into a thin film.

We claim:  
     
         1 . A composition that includes a solid state film forming alkylsilsesquioxane polymer and an inert binder.  
     
     
         2 . The composition of  claim 1  wherein said solid state film forming alkylsilsesquioxane polymer comprises 10-50% by weight of said composition.  
     
     
         3 . The composition of  claim 1  pressed into a tablet.  
     
     
         4 . The composition of  claim 1  pressed into a metal cup.  
     
     
         5 . The composition of  claim 1  wherein said solid state film forming alkylsilsesquioxane polymer is derived from RmSiXn where the non-polar R is a substituted silane or siloxane, an alkyl, a per-fluorinated alkyl, an alkyl ether, or a per-fluorinated alkyl ether group of 6-20 carbon atoms and most preferably 10-20 carbon atoms, where X is selected from the group consisting of halogens, hydroxy, alkoxy and acetoxy groups, and where m is 1-3, n is 1-3 and m+n equal 4.  
     
     
         6 . The composition of  claim 1  wherein said solid state film forming alkylsilsesquioxane polymer is derived from RmSiXn, where R is C 18 , X is an ethoxy group, m is 1-3, n is 1-3 and m+n equal 4.  
     
     
         7 . The composition of  claim 1  wherein said solid state film forming alkylsilsesquioxane polymer is derived from alkylsilanes.  
     
     
         8 . The composition of  claim 1  wherein said solid state film forming alkylsilsesquioxane polymer is derived from RmSiXn where R is an alkyl and alkyl ether or a fluorinated alkyl and fluorinated alkyl ether chain containing C6-C20, where X is Cl, Br, I, an alkoxy group or an acetoxy group, and where m is 1-3, n is 1-3 and m+n equal 4.  
     
     
         9 . The composition of  claim 1  wherein said solid state film forming alkylsilsesquioxane is derived from octadecyltrichlorosilane.  
     
     
         10 . The composition of  claim 1  wherein said binder includes one or more of titanium dioxide, silica and alumina.  
     
     
         11 . The composition of  claim 1  wherein said binder comprises metal oxide powder.  
     
     
         12 . A composition containing a metal oxide powder and 10-50% by weight of solid state film forming alkylsilsesquioxane polymer powder.  
     
     
         13 . The composition of  claim 12  wherein said composition is compressed into a tablet.  
     
     
         14 . The composition of  claim 12  wherein said composition is compressed into a metal cup.  
     
     
         15 . A composition containing a metal oxide powder and 10-50% by weight of a solid state film forming substance having amphiphilic molecules that are capable of self-assembly into a thin film on a substrate surface.  
     
     
         16 . A method of coating substrate surfaces with a hydrophobic thin film of amphiphilic molecules comprising the steps of positioning a substrate and a solid state film forming substance of amphiphilic molecules within a vacuum chamber, evaporating the film forming substance to form a molecular beam of amphiphilic molecules, and allowing the amphiphilic molecules in the molecular beam to settle on the substrate surface and self-assemble thereon into a hydrophobic thin film.  
     
     
         17 . The method of  claim 16  including the step of rotating said substrate while said amphiphilic molecules in said molecular beam settle thereon within said vacuum chamber.  
     
     
         18 . The method of  claim 16  including the step of maintaining the temperature within said vacuum chamber at less than 100° C.  
     
     
         19 . The method of  claim 16  wherein said step of evaporating is carried out to provide a film formation on the substrate surface at a rate of 0.1-1.0 nanometers of film thickness per second.  
     
     
         20 . The method of  claim 19  wherein the film formation rate is 0.4-0.6 nanometers of film thickness per second.  
     
     
         21 . The method of  claim 16  wherein said method is carried out for a time to provide the substrate with a film having a thickness of 3-100 nanometers.  
     
     
         22 . The method of  claim 21  wherein the method is carried out for a time to provide the substrate with a film having a thickness of 6-15 nanometers.  
     
     
         23 . The method of  claim 16  including the step of maintaining the vacuum chamber at a vacuum of 1×10 −4  to 1×10 −6  torr.  
     
     
         24 . The method of  claim 16  wherein the step of positioning a solid state film forming substance of amphiphilic molecules within a vacuum chamber is carried out by positioning within the vacuum chamber a composition that includes a mixture of an inert powder and a powdered film forming substance of amphiphilic molecules.  
     
     
         25 . The method of  claim 24  wherein the step of positioning a composition in the chamber is carried out by positioning the composition in the form of a compressed tablet.  
     
     
         26 . The method of  claim 24  wherein the step of positioning a composition in the chamber is carried out by positioning the composition compressed within a metal cup.  
     
     
         27 . The method of  claim 24  wherein the step of positioning a composition is carried out positioning a composition that includes a mixture of a metal oxide powder and a powdered film forming substance of amphiphilic molecules.  
     
     
         28 . The method of  claim 27  wherein the step of positioning a composition is carried out by positioning a composition that contains 10-50% by weight of the powdered film forming substance of amphiphilic molecules.  
     
     
         29 . A method of coating substrate surfaces with a hydrophobic thin film of amphiphilic molecules comprising the steps of positioning within a vacuum chamber a substrate and a solid composition that contains a solid state film forming substance of amphiphilic molecules, heating the composition to evaporate the film forming substance and form a molecular beam of amphiphilic molecules, allowing the amphiphilic molecules in the molecular beam to settle on the substrate surface and self-assemble thereon into a hydrophobic thin film, and maintaining the temperature within the vacuum chamber below 100° C.  
     
     
         30 . The method of  claim 29  including the step of maintaining the vacuum chamber at a vacuum of 1×10 −4  to 1×10 −6  torr.  
     
     
         31 . In a method of producing a solid state film forming alkylsilsesquioxane polymer of amphiphilic molecules by the hydrolysis and polymerization of monomers, the step of heating the alkylsilsesquioxane polymer in a vacuum to remove residual water therefrom and provide a dehydrated product.  
     
     
         32 . The method of  claim 31  wherein the step of heating in a vacuum is carried out at a temperature of 160-180° C.  
     
     
         33 . The method of  claim 32  wherein the step of heating in a vacuum is carried out at a vacuum at least as low as 1×10 −2  torr.  
     
     
         34 . The method of  claim 33  wherein the step of heating in a vacuum is carried out for at least one hour.  
     
     
         35 . The method of  claim 31  including the step of crushing the dehydrated alkylsilsesquioxane polymer product to a fine powder.