Corrosion inhibitors containing anionic surfactants

Abstract

The invention relates to the use of compounds of the formula (1) in which R 1 is C 1 - to C 29 -alkyl, C 2 - to C 29 -alkenyl, C 6 - to C 30 -aryl or C 7 - to C 30 -alkylaryl, and anionic surfactants as corrosion inhibitors.

1 . A method for inhibiting corrosion on a metal surface, said method comprising contacting said metal surface with a composition comprising a metal salt of the compound of the formula (1) 
       
         
           
           
               
               
           
         
       
       in which R 1  is C 1 - to C 29 -alkyl, C 2 - to C 29 -alkenyl, C 6 - to C 30 -aryl or C 7 - to C 30 -akylaryl, and an anionic surfactant. 
     
     
         2 . The method of  claim 1 , wherein R 1  is an alkyl or alkenyl group having 7 to 17 carbon atoms. 
     
     
         3 . The method of  claim 1 , wherein the metal salt is an alkali metal salt. 
     
     
         4 . The method of  claim 1 , wherein the anionic surfactant is an alkylphosphate which carries an alkyl group having 6 to 30 carbon atoms or an alkylaryl group having 7 to 30 carbon atoms. 
     
     
         5 . The method of  claim 1 , wherein the anionic surfactant is an alkyl ether phosphate which carries an alkyl group having 6 to 30 carbon atoms or an alkylaryl group having 7 to 30 carbon atoms. 
     
     
         6 . The method of  claim 1 , wherein the anionic surfactant is an alkylphosphonate of the formula (2) 
       
         
           
           
               
               
           
         
       
       in which R is a C 6 - to C 30 -alkyl radical or a C 7 - to C 30 -alkylaryl radical and M is a cation. 
     
     
         7 . The method of  claim 1 , wherein the anionic surfactant is an alkylpolyalkylene glycol ether carboxylate or alkylarylpolyalkylene glycol ether carboxylate of the formula RO(A) m CO 2 M, in which R is a C 4 -C 30 -alkyl or a C 7 -C 30 -alkylaryl radical, A is an ethoxy or propoxy unit, m is a number greater than 0 and M is a cation. 
     
     
         8 . The method of  claim 1 , wherein the anionic surfactant is an N-acylmethyltaurate of the formula R(C═O)(NCH 3 )CH 2 CH 2 SO 3 M, in which R is a C 5 -C 29 -alkyl or a C 5 -C 29 -alkenyl radical and M is a cation. 
     
     
         9 . The method of  claim 1 , the anionic surfactant is an N-acylsarcosinate of the formula R(C═O)(NCH 3 )CH 2 CO 2 M, in which R is a C 5 -C 29 -alkyl or a C 5 -C 29 -alkenyl radical and M is a cation. 
     
     
         10 . The method of  claim 1 , wherein the anionic surfactant is an N-acylglutamate of the formula (3) 
       
         
           
           
               
               
           
         
       
       in which R is a C 5 -C 29 -alkyl or a C 5 -C 29 -alkenyl radical and M is a cation. 
     
     
         11 . The method of  claim 1 , wherein the anionic surfactant is an alkylsuccinate of the formula (4) 
       
         
           
           
               
               
           
         
       
       in which D is —CH 2 CHR—, R is a C 6 -C 30 -alkyl or a C 6 -C 30 -alkenyl radical, R′ is hydrogen or a C 1 -C 18 -alkyl or a C 3 -C 18 -alkenyl radical and M is a cation. 
     
     
         12 . The method of  claim 1 , the anionic surfactant is an alkylsuccinimide of the formula (5) 
       
         
           
           
               
               
           
         
       
       in which R is a C 6 -C 30 -alkyl or a C 6 -C 30 -alkenyl radical and M is a cation. 
     
     
         13 . The method of  claim 1 , wherein a total amount of metal salt to nonionic surfactant is from 5 to 5000 ppm. 
     
     
         14 . The method of  claim 1 , wherein a weight ratio of metal salt to nonionic surfactant is from 1:9 to 9:1. 
     
     
         15 . The method of  claim 1 , wherein said composition further comprises a hydrocarbon and said metal surface is an apparatus for conveying and transporting the hydrocarbon. 
     
     
         16 . The method of  claim 1 , wherein the composition further comprises a metal processing composition. 
     
     
         17 . A composition containing at least one metal salt of a compound of the formula (1) 
       
         
           
           
               
               
           
         
       
       in which R 1  is C 1 - to C 29 -alkyl, C 2 - to C 29 -alkenyl, C 6 - to C 30 -aryl or C 7 - to C 30 -alklaryl, and at least one anionic surfactant. 
     
     
         18 . The composition as claimed in  claim 17 , wherein a weight ratio of metal salt to nonionic surfactant is from 9:1 to 1:9.