Corrosion inhibitors containing cationic surfactants

Abstract

The invention relates to the use of compositions containing metal salts 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 cationic surfactants as corrosion inhibitors.

1 . The use of compositions containing metal salts of compounds of the formula (1) 
       
         
           
           
               
               
           
         
         in which R′ 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 cationic surfactants as corrosion inhibitors. 
       
     
     
         2 . The use as claimed in  claim 1 , R′ being an alkyl or alkenyl group having 7 to 17 carbon atoms. 
     
     
         3 . The use as claimed in  claim 1  and/or  2 , the metal salt being an alkali metal salt. 
     
     
         4 . The use as claimed in one or more of  claims 1  to  3 , the cationic surfactant being a quaternary ammonium salt which contains at least one C 8 - to C 24 -alkyl or alkenyl group linked to the nitrogen atom of the ammonium group. 
     
     
         5 . The use as claimed in one or more of  claims 1  to  4 , the cationic surfactant being an ester quat which is obtainable by esterification of an amino alcohol with a C 8 - to C 24 -fatty acid and subsequent quaternization of the amino groups with a methylating agent. 
     
     
         6 . The use as claimed in one or more of  claims 1  to  5 , the cationic surfactant corresponding to the formula (2) 
       
         
           
           
               
               
           
         
         in which 
         R1 is C 5 - to C 22 -alkyl 
         R2 is methyl 
         R3 is methyl or -A-(OA) n -OH 
         R4 is -A-(OA) n -OH 
         A is —C 2 H 4 — 
         n is a number from 0 to 20 
         X is a suitable anion. 
       
     
     
         7 . The use as claimed in one or more of  claims 1  to  6 , the cationic surfactant corresponding to the formulae (3) to (5) 
       
         
           
           
               
               
           
         
         in which 
         R is C 4 - to C 22 -alkyl, C 4 - to C 22 -alkenyl or C 4 - to C 22 -alkylaryl 
         R1 is H, C 1 - to C 3 -alkyl or C 2 - to C 3 -hydroxyalkyl 
         n is a number from 0 to 10 
         X is a suitable anion. 
       
     
     
         8 . The use as claimed in  claim 6  or  7 , wherein X is an anion selected from chloride, bromide, iodide, fluoride, sulfate, hydrogen sulfate, carbonate, bicarbonate, acetate, citrate, phosphate, mono- and dihydrogen phosphate, pyrophosphate, polyphosphate, metaphosphate, nitrate, methylsulfate, phosphonate, methylphosphonate, methanedisulfonate, methylsulfonate, ethanesulfonate or an anion of the formulae R 6 SO 3 , R 7 SO 4  or R 6 COO, in which R 6  and R 7  are C 2 -C 20 -alkyl, preferably C 10 -C 18 -alkyl, and R 7  is additionally C 1 -C 18 -alkylphenyl. 
     
     
         9 . The use as claimed in one or more of  claims 1  to  8 , wherein the total amount of metal salt to cationic surfactant is from 5 to 5000 ppm. 
     
     
         10 . The use as claimed in one or more of  claims 1  to  9 , wherein the weight ratio of metal salt to cationic surfactant is from 1:9 to 9:1. 
     
     
         11 . The use as claimed in one or more of  claims 1  to  10  as corrosion inhibitors in apparatuses for conveying and transporting hydrocarbons in oil production and processing. 
     
     
         12 . The use as claimed in one or more of  claims 1  to  11  as corrosion inhibitors in metal processing compositions. 
     
     
         13 . A composition containing at least one metal salt of a compound of the formula (1) 
       
         
           
           
               
               
           
         
         in which R′ 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 cationic surfactant. 
       
     
     
         14 . The composition as claimed in  claim 13 , wherein the weight ratio of metal salt to cationic surfactant is from 9:1 to 1:9.