Corrosion inhibiting metal working fluid

DETAILED DESCRIPTION What is claimed is: 1.
A water-base composition which is non corroding to metals in contact therewith comprising an effective corrosion inhibiting amount of a concentrate comprising: A.
2-heptyl-1-ethoxypropionic acid imidazoline, sodium salt in an amount of at least about 2 wt %; B.
a free amine selected from the group consisting of diethanolamine, triethanolamine and mixtures thereof in an amount of about 20 to 27 wt %; and C.
an amine salt of a dicarboxylic acid selected from the group consisting of the diethanolamine and triethanolamine salts of a C.
sub.
8 to C.
sub.
14 dicarboxylic acid and mixtures thereof in an amount such that the weight ratio of amine salt to free amine is about 3:8 to 5:8.
2.
The water-base composition of claim 1 wherein in the concentrate the weight ratio of amine salt to free amine is about 4:8.
3.
The water-base composition of claim 1 wherein in the concentrate the 2-heptyl-1-ethoxy propionic acid imidazole, sodium salt is in an amount of about 2 wt %.
4.
The water-base composition of claim 1 wherein in the concentrate the dicarboxylic acid is a linear dicarboxylic acid.
5.
The water-base composition of claim 1 wherein in the concentrate the dicarboxylic acid is a mixture of linear dicarboxylic acids.
6.
The water-base composition of claim 1 wherein in the concentrate the free amine is triethanolamine and the amine salt is a triethanolamine salt.
7.
The water-base composition of claim 1 wherein the concentrate additionally comprises an ethoxylated nonylphenol.
8.
A water-based composition which is non corroding to metals in contact therewith comprising an effective corrosion inhibiting amount of a concentrate comprising: A.
2-heptyl-1-ethoxypropionic acid imidazoline, sodium salt in an amount of at least about 2 wt %; B.
triethanolamine is an amount of about 20 to 27 wt %; and C.
the triethanolamine salt of a dicarboxylic acid selected from the group consisting of a linear C.
sub.
8 to C.
sub.
14 dicarboxylic acid and mixtures thereof in an amount such that the weight ratio of triethanolamine salt to triethanolamine is about 4:8