Corrosion inhibitors containing nonionic 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 nonionic 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 (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 a nonionic 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 nonionic surfactant is an adduct of from 1 to 25 mol of ethylene oxide and an alcohol having a C 4 — to C 30 -alkyl or C 4 — to C 30 -alkenyl radical. 
     
     
         5 . The method of  claim 1 , wherein the nonionic surfactant is a product of an addition reaction of from 1 to 40 mol of ethylene oxide with a water-insoluble condensate of propylene oxide and propylene glycol having a molecular weight of from 1500 to 1800 g/mol. 
     
     
         6 . The method of  claim 1 , wherein the nonionic surfactant is obtained by the addition of propylene oxide to ethylenediamine up to a molecular weight of from 2500 to 3000 g/mol, and subsequent ethoxylation up to a molecular weight of from 5000 to 11 000. 
     
     
         7 . The method of  claim 1 , wherein the nonionic surfactant is an alkoxylated C 4 — to C 24 -alkylphenol. 
     
     
         8 . The method of  claim 1 , the nonionic surfactant an alkoxylated tributylphenol or tristyrylphenol. 
     
     
         9 . The method of  claim 1 , wherein the nonionic surfactant is a compound of formula 3 
       
         
           
           
               
               
           
         
         in which 
         R is C 7 -C 21 -alkyl, 
         R 1  in each case is alkyl or hydroxyalkyl having 1 to 4 carbon atoms or (C 2 H 4 O) x —H 
         x is a number from 1 to 3. 
       
     
     
         10 . The method of  claim 1 , wherein a total amount of metal salt to nonionic surfactant is from 5 to 5000 ppm. 
     
     
         11 . The method of  claim 1 , wherein a weight ratio of metal salt to nonionic surfactant is from 1:9 to 9:1. 
     
     
         12 . 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. 
     
     
         13 . The method of  claim 1 , wherein the composition further comprises a metal processing composition. 
     
     
         14 . 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 -alkylaryl, and at least one nonionic surfactant. 
       
     
     
         15 . The composition as claimed in  claim 14 , wherein a weight ratio of metal salt to nonionic surfactant is from 9:1 to 1:9.