Corrosion inhibitors containing anionic surfactants
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.