Process and compositions for corrosion inhibition of metallic materials

Claim 1

A process for inhibiting corrosion of metallic materials in the presence of an aqueous medium, which comprises adding to the aqueous medium a compound of the formula I or II ##STR14## in which R 1 denotes C 12 -C 26 -alkyl or C 12 -C 26 -alkenyl; n denotes a number from 0 to 5; Z.sup.⊕ denotes a group of the formula ##STR15## where R 2 is C 1 -C 3 -alkyl and R 3 is C 1 -C 3 -alkyl or a group of the formula --C 2 H 4 O-- x H, x being a number from 1 to 3; A.sup.⊖ denotes an anion of the following formulae: SCN.sup.⊖ or R 4 SO 3 ⊖, where R 4 is C 6 -C 9 -alkyl or C 6 -C 9 -alkenyl, provided that the sum of the carbon atoms is R 1 and R 4 is at least 21; or A.sup.⊖ is ##STR16## where Hal is fluorine, chlorine, bromine or iodine, R 5 is C 1 -C 5 -alkyl, C 2 -C 5 -alkenyl or C 1 -C 5 -alkoxy in the 3, 4, 5 and 6 positions and R 6 is hydrogen or hydroxy in the 2 and 3 positions to the carboxyl group or A.sup.⊖ is ##STR17## where R 7 is COO - or SO 3 (-) and R 8 is hydrogen or methyl, and in which: R 9 denotes a group of the formula R 12 --(OCH 2 CH 2 )y--, C 8 -C 18 -alkylaryl or aryl-C 8 -C 18 -alkyl, R 12 denotes C 14 -C 22 -alkyl or C 14 -C 22 -alkenyl, y denotes a number from 0 to 5 and the radicals R 10 are identical and denote C 1 -C 4 -alkyl or C 1 -C 4 -hydroxyalkyl, said compound of formula I or II being in an amount effective to inhibit corrosion of a metallic material and inhibiting corrosion of said metallic material.