Corrosion inhibitors containing nonionic 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 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.