Transparent substrate and method of manufacturing the same

Abstract

At least one monomolecule film is formed on a transparent substrate surface directly or via a protective film. The monomolecule film is formed with chemical coupling of chlorosilane surface active compound, for example, of the formula: F(CF 2 )m(CH 2 )nSiR q X 3 — q where m is an integer of from 1 to 15, n is an integer of from 0 to 15 provided that the total of m and n is an integer of from 10 to 30 and R is an alkyl or an alkoxyl group, or F(CF 2 )m′(CH 2 )n′A(CH 2 )pSiR q X 3—q where m represents an integer ranging from 1 to 8, n′ represents an integer ranging from 0 to 2, p represents an integer ranging from 5 to 25, q represents an integer ranging from 0 to 2, X represents a halogen atom or an alkoxyl group, R represents an alkyl or an alkoxyl group, and A represents —0—, a —COO— or —Si(CH 3 ) 2 —. The transparent substrate such as glass is made hydrophobic and free of contamination.

What is claimed:  
     
         1 . A transparent substrate comprising at least one monomolecule film formed as an outer most surface layer on at least one surface of the transparent substrate either directly or indirectly, wherein the monomolecule film contains a hydrophobic group and is bonded through a covalent bond to the surface of the substrate.  
     
     
         2 . The transparent substrate according to  claim 1 , wherein the monomolecule film containing hydrophobic groups is bonded to the surface through a —Si— group.  
     
     
         3 . The transparent substrate according to  claim 1 , wherein the monomolecule film containing hydrophobic group is bonded to the surface through siloxane bonds via a siloxane-based protective film prepared on the substrate.  
     
     
         4 . The transparent substrate according to  claim 1 , wherein the hydrophobic group is a fluorine-containing hydrocarbon group.  
     
     
         5 . A transparent substrate comprising a monomolecule film formed as an outer most surface layer on both surfaces of the transparent substrate either directly or indirectly, wherein one of the surfaces is covered with a covalently bonded monomolecule film containing a hydrophobic group, and the other surface is covered with a covalently bonded monomolecule film containing a hydrophilic group.  
     
     
         6 . The transparent substrate according to  claim 5 , wherein the hydrophobic group is a fluorine-containing hydrocarbon group.  
     
     
         7 . The transparent substrate according to  claim 5 , wherein the hydrophilic groups is a hydroxyl group.  
     
     
         8 . A transparent substrate comprising at least one monomolecule film formed as an outer most surface layer on at least one surface of the transparent substrate either directly or via a protective film, wherein the monomolecule film is formed by a chemical covalent bonding from a silane halide-based or alkoxy silane-based surface active compound of the formula:  
       A)F′(CF 2 )m(CH 2 )n Si Rq X 3—q    
       where m represents an integer ranging from 1 to 15, n represents an integer ranging from 0 to 15, the sum of m and n ranges from 10 to 30, q represents an integer ranging from 0 to 2, R represents an alkyl or an alkoxyl group, and X is a halogen atom or an alkoxyl group, or of the formula:  
       F(CF 2 )m′(CH 2 )n′A(CH 2 )p SiR q X 3—q    (B)  
       [where m′ represents an integer ranging from 1 to 8, n′ represents an integer ranging from 0 to 25, q represents an integer ranging from 5 to 25, q represents an integer ranging from 0 to 2, X represents a halogen atom or an alkoxyl group, R represents an alkyl or an alkoxyl group, and A represents —0—, a —COO— or —Si(CH 3 ) 2 —].  
     
     
         9 . The transparent substrate according to  claim 8 , wherein the monomolecule film is bonded to the protective film covering the substrate through a chemical covalent bond.  
     
     
         10 . The transparent substrate according to  claim 8 , wherein said silane halide-based surface active compound is a chlorosilane-based surface active compound of the formula:  
       CF 3 (CH 2 ) 2 Si(CH 3 ) 2 (CH 2 ) 15 SiOl 3,  CF 3 (CF 2 ) 3 (CH 2 ) 2 Si(CH 3 ) 2 (CH 2 ) 9 SiOl 3 , CF 3 CH 2 O(CH 2 )15SiCl 3 , CF 3 COO(CH 2 )15SiCl 3 , CF 3 (CF 2 ) 7 (CH 2 ) 2 Si(OCH 3 )Cl 2 , or CF 3 (CF 2 ) 7 (CH 2 ) 2 Si(CH 3 )Cl 2 . 
     
     
         11 . A method of modifying a surface of a transparent substrate comprising: 
 applying, in a non-aqueous organic solvent, a silane-based surface active compound having a reactive silane group at one end and a hydrophobic group at the other end containing fluorine, to a surface of the transparent substrate or on a surface of a protective film provided on the transparent substrate under such conditions that the silane-based surface active compound is chemically adsorbed to the surface, thereby forming a monomolecule film having the hydrophobic group and —Si— group and being covalently bonded to the applied surface.    
     
     
         12 . The method of according to  claim 11 , wherein the silane-based surface active compound is a chemical material containing an end chlorosilyl (—SiCl) group.  
     
     
         13 . A method of modifying a surface of a transparent substrate comprising: 
 contacting a surface of a molded transparent substrate with an organic solvent solution of a silane-based surface active compound having a reactive silane group at one end and a hydrophobic group at the other end to form a chemically adsorbed monomolecule film from the silane-based surface active compound on at least one surface of the transparent substrate or over the entire surface area    
     
     
         14 . The method according to  claim 13 , wherein the reactive silane group is a chlorosilane group.  
     
     
         15 . The method according to  claim 13 , wherein the silane-based surface active compound is represented by the formula:  
       CF 3 —(CF 2 ) t —(R 2 ) r —SiCl V Y 3—v    
       [where t is an integer of at least 0, preferably 0 to 10, is 0 or 1, R 2  is an alkylene group of from 1 to 20 carbon atoms which may contain a vinylene (—CH=CH—), ethynylene (—C±C—) group or may be interrupted by a —0—, —Si(CH 3 ) 2  —or —COO—, Y is a hydrogen atom, a lower alkyl group or lower alkoxyl group and v is an integer ranging from 0 to 2.  
     
     
         16 . A transparent method of modifying a surface of a molded substrate having two surface, comprising: 
 (A) contacting both of the surface of the molded transparent substrate with a non-aqueous solvent containing a material having at least two chlorosilyl groups;    (B) washing the transparent substrate using a non-aqueous organic solution to remove the non-reacted material having at least two chlorosilyl groups of the transparent substrate after the contacting step;    (C) treating the transparent substrate with water after the non-reacted material washing step, thereby forming a hydrophilic monomolecule film composed of a silane material having at least one silanol group; and    (D) treating the transparent substrate having thus formed silanol groups with silane-based surface active compound having a reactive silane group at one end and a hydrophobic group at the other end, thereby laminating a chemically adsorbed hydrophobic monomolecule film on the hydrophilic monomolecule film having silanol groups.    
     
     
         17 . The method according to  claim 16 , which further comprises between the steps (C) and (D), coating one surface of the transparent substrate with a water-soluble coating film and, after the step (D), removing the water soluble coating film, thereby forming a hydrophobic monomolecule film on one surface and a hydrophilic monomolecule film on the other surface.  
     
     
         18 . The method according to  claim 16 , wherein the reactive silane group is a chlorosilane group.  
     
     
         19 . The method according to  claim 16 , wherein the silane-based surface active compound is represented by the formula:  
       CF 3 —(CF 2 ) t —(R 2 )r—SiCl v Y 3—v    
       where t is an integer of at least 0, preferably 0 to 10, r is 0 or 1, R is an alkylene group of from 1 to 20 carbon atoms which may contain a vinylene (—CH=CH—), ethynylene (—C±C—) group or may be interrupted by a —0—, —Si(CH 3 )2 —or —COO—, Y is a hydrogen atom, a lower alkyl group or lower alkoxyl group and v is an integer ranging from 0 to 2.  
     
     
         20 . The method according to  claim 16 , wherein the material having at least two chlorosilyl groups is selected from the group consisting of:  
       SiCl 4 ,SiHCl 3 ,SiH 2 Cl 2 , and Cl—(SiCl 2 O) n SiCl 3    
       (where n is an integer of 1 to 4)  
     
     
         21 . A transparent substrate comprising at least one monomolecule film formed as an outer most surface layer on at least one surface of an optical device, either directly or indirectly, wherein said monomolecule film contains a hydrophobic group and is bonded through a covalent bond to the surface of said optical device, 
 wherein said optical device is selected from the group consisting of motor vehicle glasses and windshields, building window glasses, mirrors, optical lenses, fresnel lenses, glass lenses, and transparent tempered glass.    
     
     
         22 . The transparent substrate as recited in  claim 21 , wherein said optical device is a vehicle windshield.  
     
     
         23 . The transparent substrate as recited in  claim 21 , wherein the outer surface of said substrate is sufficiently hydrophobic to render said substrate non-adherent to oil and water.  
     
     
         24 . The transparent substrate as recited in  claim 21 , wherein said monomolecule film comprises a chlorosilane molecule having a fluoroalkyl group, wherein the number of fluorine atoms counted from the end of the molecule is between 9 and 31.