Corrosion inhibited compositions

Abstract

Corrosion-inhibited compositions are described comprising a functional fluid in contact with a ferrous metal and, as corrosion inhibitor, a compound having the formula: ##STR1## wherein X is H, an alkali- or alkaline earth metal, NH.sub.4, the residue of a protonated amine, or the group --OX is the residue of an alkanol having from 1 to 20 carbon atoms or of di-, tri- or tetra-ol having from 2 to 12 carbon atoms; R.sup.1, R.sup.2 and R.sup.4 are the same or different and each is H or --CH.sub.2 CH.sub.2 COOX wherein X has its previous meaning; R.sup.3 and R.sup.5 are the same or different and each is H, --CH.sub.2 CH.sub.2 COOX wherein X has its previous meaning, or R.sup.3 or R.sup.5 is a straight- or branched chain alkyl group having from 3 to 16 carbon atoms; or R.sup.3 and R.sup.5, together with the carbon atom to which they are each attached, may form a cycloalkanone ring containing from 5 to 15 carbon atoms.

Dependencies are inferred from the claim text.