Stainless-steel foils with inorganic/organic hybrid film coating

Abstract

An inorganic-organic hybrid film-coated stainless steel foil comprising a stainless steel foil substrate having coated on one surface or both surfaces thereof an inorganic-organic hybrid film, wherein the inorganic-organic hybrid film comprises a skeleton formed of an inorganic three-dimensional network structure mainly comprising a siloxane bond, with at least one crosslinked oxygen of the skeleton being replaced by an organic group and/or a hydrogen atom; and an inorganic-organic hybrid film-coated stainless steel foil comprising a stainless steel foil having coated thereon a plurality of inorganic-organic hybrid films each mainly comprising a siloxane bond, wherein at least a part of Si constituting each inorganic-organic hybrid film is chemically bonded to one or both of an organic group and hydrogen, provided that the uppermost layer out of the plurality of inorganic-organic hybrid films may be an inorganic SiO 2 film, and adjacent films of the plurality of inorganic-organic hybrid films (including the inorganic SiO 2 film) differ in the composition from each other.

1 . An inorganic-organic hybrid film-coated stainless steel foil comprising a stainless steel foil substrate having coated on one surface or both surfaces thereof an inorganic-organic hybrid film, wherein said inorganic-organic hybrid film comprises a skeleton formed of an inorganic three-dimensional network structure mainly comprising a siloxane bond, with at least one crosslinked oxygen of said skeleton being replaced by an organic group and/or a hydrogen atom, and the ratio [H]/[Si] between hydrogen concentration [H] (mol/l) and silicon concentration [Si] (mol/l) in said film satisfies the condition of 0.1≦[H]/[Si]≦10.  
     
     
         2 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 1 , wherein said organic group is one or more member selected from an alkyl group, an aryl group, a hydroxyl group, a carboxyl group and an amino group.  
     
     
         3 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 1 , wherein the average roughness Raf of the surface of said inorganic-organic hybrid film satisfies the condition of Raf≦0.02 μm.  
     
     
         4 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 1 , wherein the thickness Tf of said inorganic-organic hybrid film satisfies the condition of 0.05 μm≦Tf≦5 μm.  
     
     
         5 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 1 , wherein the thickness Tf of said inorganic-organic hybrid film and the thickness Ts of said stainless steel foil substrate satisfy the condition of Tf≦Ts/20.  
     
     
         6 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 1 , wherein the thickness Tf of said inorganic-organic hybrid film and the average roughness Ras of the surface of said stainless steel foil substrate satisfy the condition of Ras≦Tf/2.  
     
     
         7 . An inorganic-organic hybrid film-coated stainless steel foil comprising a stainless steel foil having coated thereon a plurality of inorganic-organic hybrid films each mainly comprising a siloxane bond, wherein at least a part of Si constituting each inorganic-organic hybrid film is chemically bonded to one or both of an organic group and hydrogen, provided that the uppermost layer out of said plurality of inorganic-organic hybrid films may be an inorganic SiO 2  film, and adjacent films of said plurality of inorganic-organic hybrid films (including the inorganic SiO 2  film) differ in the composition from each other.  
     
     
         8 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 7 , wherein out of said plurality of inorganic-organic hybrid films, the thermal expansion coefficient of the upper inorganic-organic hybrid film is smaller than the thermal expansion coefficient of the lower inorganic-organic hybrid film.  
     
     
         9 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 7 , wherein the uppermost film is an SiO 2  film.  
     
     
         10 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 7 , wherein the uppermost inorganic-organic hybrid film is an inorganic-organic hybrid film in which at least a part of the Si constituting the film is bonded to hydrogen but is not bonded to an organic group.  
     
     
         11 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 7 , wherein the molar ratio of H/Si in said uppermost inorganic-organic hybrid film is 1.0 or less.  
     
     
         12 . The inorganic-organic hybrid film-coated stainless steel foil as claimed  claim 7 , wherein said uppermost inorganic-organic hybrid film has a thickness of 0.5 μm or less.  
     
     
         13 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 7 , wherein out of said plurality of inorganic-organic hybrid films, the lowermost inorganic-organic hybrid film is an inorganic-organic hybrid film in which at least a part of Si constituting the film is bonded to an alkyl group having a carbon number of 1 to 4.  
     
     
         14 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 13 , wherein said alkyl group is a methyl group.  
     
     
         15 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 14 , wherein the molar ratio of methyl group/Si in said lowermost inorganic-organic hybrid film is from 0.2 to 1.0.  
     
     
         16 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 7 , wherein said lowermost inorganic-organic hybrid film has a thickness of 0.5 to 5 μm.  
     
     
         17 . The inorganic-organic hybrid film-coated stainless steel foil as claimed in  claim 7 , which further comprises an inorganic-organic hybrid film having a medium thermal expansion coefficient between the uppermost inorganic-organic hybrid film having a small thermal expansion coefficient and the lowermost inorganic-organic hybrid film having a large thermal expansion coefficient.