Anticorrosives

DETAILED DESCRIPTION What is claimed is: 1.
Anticorrosive additive for aqueous solutions consisting essentially of an effective amount of a conventional corrosion inhibitor selected from the group consisting of sodium carbonate, sodium nitrite, sodium nitrate, borax, sodium dichromate, sodium silicate, an alkali salt of arsensous acid, arsenic acid, phosphorous acid, phosphoric acid, an alkali metal tungstate, an alkali salt of benzoic or toluic acid, an alkali metal salt of a phenol, an alkanolamine and an organosilicon compound and an amount of between 0.
03 and 2% by weight of a heterocyclic nitrogen compound having the formula ##STR4## wherein R.
sup.
1 and R.
sup.
2 are hydrogen or together with the carbon atoms to which they are attached represent an optionally substituted benzene ring; R.
sup.
3, r.
sup.
4, r.
sup.
5 and R.
sup.
6 independently of one another are selected from the group of hydrogen, lower alkyl, phenyl and phenyl substituted by one or more lower alkyls; X is sulphur or an imino group (NH) optionally substituted on the nitrogen atom; and n is an integer from 1 to 13.
2.
Anticorrosive additive of claim 1 wherein the heterocyclic nitrogen compound is selected from the group of .
DELTA.
.
sup.
2 -2-(.
epsilon.
-aminopentyl)imidazoline, .
DELTA.
.
sup.
2 -1-(.
beta.
-aminoethyl)-2-(.
epsilon.
-aminopentyl)-imidazoline, .
DELTA.
.
sup.
2 -2-(.
epsilon.
-aminopentyl)-thiazoline, 2-(.
beta.
-amino-.
beta.
-methylpropyl)-benzimidazole, 2-(.
delta.
-aminobutyl)-benzimidazole, 2-(.
epsilon.
-aminopentyl)-benzimidazole, 2-(.
lambda.
-aminoundecyl)-benzimidazole, 2-(.
epsilon.
-methylaminopentyl)-benzimidazole, 2-(.
epsilon.
-aminopentyl)-1-phenyl benzimidazole, 2-(.
epsilon.
-aminopentyl)-5-methyl benzimidazole, 2-(.
gamma.
-phenylaminopropyl)-5-methyl benzimidazole, 2-(.
gamma.
-aminopropyl)-benzthiazole, 2-(.
beta.
-amino-.
beta.
-methylpropyl)-benzthiazole, 2-(.
epsilon.
-aminopentyl)-benzthiazole, 2-(.
gamma.
-methylaminopropyl)-benzthiazole, 2-(.
epsilon.
-dimethylaminopentyl)-benzimidazole, and 2-(.
gamma.
-aminopropyl)-benzimidazole