Corrosion control method of metal

Abstract

The present invention provides a method of preventing a metal from corroding by giving a high corrosion resistance in the state of retaining the functions of the metal surface, a surface of a thin film material particularly. A stable silane coupling layer which has a robust bond is formed on a metal surface by using a silane coupling agent and an oxidizer in combination.

1 . A corrosion control method of a metal, the method comprising the steps of:
 bringing a metal substrate into contact with a solution containing an organic functional silane at least partially hydrolyzed, an oxidizer and a solvent; and   removing thereafter the solvent on the metal substrate, and thereby forming a silane coupling layer on the metal substrate.   
     
     
         2 . A corrosion control method of a metal, the method comprising the steps of:
 applying an oxidation treatment to a metal substrate;   bringing thereafter the metal substrate into contact with a solution containing an organic functional silane at least partially hydrolyzed and a solvent; and   removing thereafter the solvent on the metal substrate and thereby forming a silane coupling layer on the metal substrate.   
     
     
         3 . A corrosion control method of a metal, the method comprising the steps of:
 immersing a metal substrate in a solution containing an oxidizer;   bringing thereafter the metal substrate into contact with a solution containing at least one kind of organic functional silane, and thereby forming a silane coupling layer on the metal substrate.   
     
     
         4 . The corrosion control method according to  claim 1  or  3 , wherein the oxidizer is at least one kind selected from the group consisting of hydrogen peroxide; chloric acid, perchloric acid, persulfuric acid and nitric acid and salts thereof; ammonium persulfate; and diammonium cerium nitrate. 
     
     
         5 . The corrosion control method according to  claim 2 , wherein an oxidizer used in the oxidation treatment is air or ozone. 
     
     
         6 . The corrosion control method according to  claim 1 , further comprising a step of:
 applying a heat treatment after forming the silane coupling layer on the metal substrate.   
     
     
         7 . The corrosion control method according to  claim 2 , further comprising a step of:
 applying a heat treatment after forming the silane coupling layer on the metal substrate.   
     
     
         8 . The corrosion control method according to  claim 3 , further comprising a step of:
 applying a heat treatment after forming the silane coupling layer on the metal substrate.   
     
     
         9 . The corrosion control method according to  claim 2  or  3 , wherein the organic functional silane is represented by the following chemical formula (1) or (2),
   X 1   3-n R n SiZ  (1)
 
   X 1   3-n SiR′SiX 2   3-n   (2)
 
 
       (in the expression: n is 0 or 1; X 1  and X 2  are selected from hydrolytic groups (methoxy, ethoxy, methoxyethoxy, propyl, butyl, isobutyl, s-butyl, t-butyl and acetyl) and both the X 1  and X 2  may be either an identical substance or different substances; Z is selected from organic functional groups represented by amino, mercapto, phenyl, vinyl, epoxy, methacryl, isocyanate, ureide and sulfa, or alkyl groups; R is a methyl group; and R′ is selected from alkyl, alkenyl, and alkenyl having at least one amino group or S group substituted in place of a hydrogen atom). 
     
     
         10 . The corrosion control method according to any one of  claims 1  to  3 , wherein the metal substrate is Fe, Co, Ni or Cu, or an alloy thereof.