| abstract |
A composition, in contact with a corrodable metal surface, which composition comprises:n a) an aqueous-based or oil-based system; and b) as inhibitor for protecting the metal surface against corrosion, at least one compound having the formulan as well as salts or partial esters thereof wherein: n is 0 or an integer ranging from 1 to 20. R is a straight or branched chain C 4 -C 30 alkyl group, optionally interrupted by one, two or three oxygen atoms or substituted by one, two or three hydroxy groups, a C 5 -C 12 cycloalkyl group, a C 6 -C 10 aryl group optionally substituted by one, two or three C 1 -C 12 alkyl groups, or a C 7 -C 13 aralkyl group which is optionally substituted by a hydroxyl group; R 1 is H or a straight- or branched chain C 1 -C 4 alkyl group; R 2 is H, a straight or branched chain Ci-C 4 alkyl group or C0 2 H; R 3 is H, a straight or branched chain Ci-C 4 alkyl group, -CH 2 C0 2 H or -CH 2 CH 2 C0 2 H; R 4 is H, a straight or branched chain Ci-C 4 alkyl group or C0 2 H; Rs is H, a straight or branched chain Ci-C 4 alkyl group, CH 2 C0 2 H or CH 2 CH 2 C0 2 H; provided that at least one group R 4 must be C0 2 H, with the provisio, that compositions comprising an oil-based system and a compound having the formulan wherein R, R 1 and R 2 are hydrogen or alkyl radicals, having a total from 10 to 38 C-atoms, are excluded. |