Anti-corrosive agent for washing of metal with acid, detergent solution composition, and method for washing of metal

Abstract

An anti-corrosive agent for washing of a metal with an acid, which comprises an amphoteric polymeric compound (P) having at least one cationic constituent unit (A) having a specific structure, at least one anionic constituent unit (B) having a specific structure and a specific sulfur-containing constituent unit (C).

1 . An anti-corrosive agent for washing of a metal with an acid, comprising an amphoteric polymer compound (P) having: at least one cationic constituent unit (A) having a structure represented by the following structural formula (Ia) or (Ib), a structure corresponds to an inorganic acid salt or an organic acid salt thereof or a structure represented by the following structural formula (IIa) or formula (IIb): 
       
         
           
           
               
               
           
         
       
       wherein R 1  in formulae (Ia) and (Ib), above, is hydrogen atom, methyl group, ethyl group, or benzyl group; R 2  and R 3  in formulae (IIa) and (IIb), above, each independently are hydrogen atom, methyl group, ethyl group, or benzyl group; and X −  in formulae (IIa) and (IIb), above, is a counter ion;
 at least one anionic constituent unit (B) represented by the following structural formula (III), (IV) or (V): 
 
       
         
           
           
               
               
           
         
       
       wherein R 4  in formula (III), above, is hydrogen or methyl group; and Y in formulae (III), (IV) and (V) each independently are hydrogen, Na, K, NH 4 , ½Ca, ½Mg, ½Fe, ⅓Al, or ⅓Fe for each carboxy group to which they are bonded); and
 a constituent unit (C) represented by the following structural formula (VI): 
 
       
         
           
           
               
               
           
         
       
     
     
         2 . The anti-corrosive agent according to  claim 1 , wherein the counter ion X −  is an anion derived from an organic acid or an inorganic acid. 
     
     
         3 . The anti-corrosive agent according to  claim 1 , wherein at least a part of the cationic constituent unit (A) is derived from a cationic monomer selected from the group consisting of diallylamines and inorganic acid salts and organic acid salts thereof. 
     
     
         4 . The anti-corrosive agent according to  claim 1 , wherein at least a part of the cationic constituent unit (A) is derived from diallyldimethylammonium chloride and at least a part of the anionic constituent unit (B) is derived from maleic acid. 
     
     
         5 . An anti-corrosive agent for washing of a metal with an acid, comprising an amphoteric polymer compound (F) obtainable by copolymerizing:
 at least one monomer (a) having a structure represented by the following structural formula (VII), a corresponds to an inorganic acid salt or an organic acid salt thereof or a structure represented by the following structural formula (VIII):   
       
         
           
           
               
               
           
         
       
       wherein R 5  in formula (VII), above, is hydrogen atom, methyl group, ethyl group, or benzyl group; R 6  and R 7  in formula (VIII), above, each independently are hydrogen atom, methyl group, ethyl group, or benzyl group; and Z −  in formula (VIII), above, is a counter ion);
 at least one monomer (β) selected from the group consisting itaconic acid, citraconic acid, mesaconic acid, maleic acid, fumaric acid, methylenemalonic acid, and compounds in which the hydrogens in the carboxyl groups in these acids are entirely or partially substituted with at least one species selected from the group consisting of Na, K, NH 4 , ½Ca, ½Mg, ½Fe, ⅓Al, and ⅓Fe; and 
 sulfur dioxide. 
 
     
     
         6 . A detergent solution composition comprising an acid solution and an anti-corrosive agent according to  claim 1 , wherein the content of the amphoteric polymer compound (P) or the amphoteric polymer compound (P′) is 0.1 to 50000 mg based on 1 L of the acid solution. 
     
     
         7 . A method for washing a metal, characterized in that the detergent solution composition according to  claim 6  is sprayed to the surface of the metal or the surface of the metal is immersed in the detergent solution composition to carryout the washing. 
     
     
         8 . A detergent solution composition comprising an acid solution and an anti-corrosive agent according to  claim 5 , wherein the content of the amphoteric polymer compound (P) or the amphoteric polymer compound (P′) is 0.1 to 50000 mg based on 1 L of the acid solution. 
     
     
         9 . A method for washing a metal, characterized in that the detergent solution composition according to  claim 8  is sprayed to the surface of the metal or the surface of the metal is immersed in the detergent solution composition to carryout the washing.