Sealing liquid for anodic oxide coating films of aluminum alloy, concentrated liquid and sealing method

Abstract

The present invention provides a sealing treatment solution free from a nickel salt. The sealing treatment solution is capable of ensuring a sealing performance comparative to that in the method using a sealing treatment solution containing a nickel salt, and ensuring that the resulting sealing-treated anodic oxide film has excellent contamination resistance. The present invention provides a sealing treatment solution for anodic oxide film of aluminum alloy, the sealing treatment solution comprising a metal salt, a pH buffer, and a surfactant, the metal salt being at least one member selected from alkali metal salts and alkaline-earth metal salts.

1 - 17 . (canceled) 
     
     
         18 . A sealing treatment solution for anodic oxide film of aluminum alloy, the sealing treatment solution comprising a metal salt, a pH buffer, and a surfactant, the metal salt being at least one member selected from the group consisting of alkali metal salts and alkaline-earth metal salts, the pH buffer being a nitrogen-containing heterocyclic compound. 
     
     
         19 . The sealing treatment solution according to  claim 18 , wherein the metal salt is a metal salt of at least one metal selected from the group consisting of Na, Mg, K and Ca. 
     
     
         20 . The sealing treatment solution according to  claim 18 , wherein the metal salt is a metal salt of at least one metal selected from the group consisting of Mg and Ca. 
     
     
         21 . The sealing treatment solution according to  claim 18 , wherein the metal salt is at least one member selected from the group consisting of acetates, sulfamates, sulfates, and nitrates. 
     
     
         22 . The sealing treatment solution according to  claim 18 , wherein the metal salt is a nitrate. 
     
     
         23 . The sealing treatment solution according to  claim 18 , wherein the surfactant is at least one member selected from the group consisting of anionic surfactants and ampholytic surfactants. 
     
     
         24 . The sealing treatment solution according to  claim 18 , wherein the surfactant is at least one member selected from the group consisting of sulfate-based surfactants, sulfonate-based surfactants, and phosphoric ester-based surfactants. 
     
     
         25 . The sealing treatment solution according to  claim 18 , wherein the sealing treatment solution has a pH of 7.0 to 10.0. 
     
     
         26 . The sealing treatment solution according to  claim 18 , wherein the sealing treatment solution is free from nickel-based metal salt. 
     
     
         27 . The sealing treatment solution according to  claim 18 , wherein the total amount of the metal salt, the pH buffer, and the surfactant in the sealing treatment solution is 0.2 to 100 g/L. 
     
     
         28 . A concentrated liquid of a sealing treatment solution for anodic oxide film of aluminum alloy, the sealing treatment solution comprising a metal salt, a pH buffer, and a surfactant, the metal salt being at least one member selected from the group consisting of alkali metal salts and alkaline-earth metal salts, the pH buffer being a nitrogen-containing heterocyclic compound. 
     
     
         29 . A sealing treatment method for anodic oxide film of aluminum alloy, comprising the step of:
 immersing an article having an anodic oxide film of aluminum alloy in a sealing treatment solution for an anodic oxide film of aluminum alloy,   the sealing treatment solution comprising a metal salt, a pH buffer, and a surfactant, and   the metal salt being at least one member selected from the group consisting of alkali metal salts and alkaline-earth metal salts, the pH buffer being a nitrogen-containing heterocyclic compound.   
     
     
         30 . The sealing treatment method according to  claim 29 , wherein the sealing treatment solution has a liquid temperature of 85 to 100° C. 
     
     
         31 . The sealing treatment method according to  claim 29 , wherein the sealing treatment solution has a pH of 7.0 to 10.0. 
     
     
         32 . An article sealed by the sealing treatment method according to  claim 29 .