Reaction products of sulfonamido-carboxylic acids or carboxamido-carboxylic acids with alkanolamines, and their use as low-foaming corrosion inhibitors

Abstract

Products which have been obtained by reacting an acid of the formula I ##STR1## where R.sup.1 and R.sup.2 are hydrogen, fluorine, chlorine, bromine or alkyl or alkoxy of 1 to 4 carbon atoms, but the sum of the carbon atoms of R.sup.1 and R.sup.2 is not greater than 7 and preferably not greater than 3, A is a benzene, naphthalene or anthracene radical or a biphenyl structure, such as a diphenyl, diphenylmethane, diphenyl ether, diphenyl sulfide, diphenyl sulfoxide or diphenyl sulfone radical, R.sup.3 is hydrogen, alkyl of not more than 4 carbon atoms, .beta.-cyanoethyl or hydroxyalkyl of 2 to 4 carbon atoms, R.sup.4 is hydrogen, fluorine, chlorine, bromine, alkyl or alkoxy of 1 to 4 carbon atoms, hydroxyl or carboxyl and X is --SO.sub.2 -- or --CO--, with an amine of the formula II ##STR2## where R.sup.5 and R.sup.6 are hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.2 -C.sub.4 -hydroxyalkyl and/or ##STR3## R.sup.7 and R.sup.8 being hydrogen, C.sub.1 -C.sub.4 -alkyl or C.sub.2 -C.sub.4 -hydroxyalkyl and n being an integer from 2 to 4, in the ratio, expressed in terms of equivalents, of from 1:1 to 1:4, and corrosion inhibitors which contain these products, with or without the admixture of an alkanolamine/boric acid reaction product.

Dependencies are inferred from the claim text.