Control of corrosion and scale in circulating water systems by means of partial esters of polyfunctional organic acids

A process for inhibiting corrosion and scale on ferrous metal surfaces in a circulating water system comprising the addition to circulating water in said system an effective amount of additive selected from partial ester compounds having the formula:

• ##STR21## R is a hydrocarbon radical having 8 to 20 carbon atoms selected from alkyl, alkenyl, cycloalkyl and arylalkyl;
• m is a value from 1 to 5;
• Z is hydrogen or methyl;
• Y is selected from alkylene or arylene having 2 to 8 carbon atoms, ##STR22## where n is from 2 to 6, ##STR23## where n is from zero to 3, ##STR24## wherein R' is alkyl or alkenyl of 1 - 12 carbon atoms, ##STR25## where y is .ltoreq. x, where x .ltoreq. 300, and ##STR26## wherein x is .gtoreq. 0, x = y .gtoreq. z, where x + y .ltoreq. 300 and R' is phenyl or a hydrocarbon radical of from 10 to 18 carbon atoms, and
• wherein m and Z are as defined before, and
• M is selected from hydrogen, ammonium, alkylammonium, polyalkylammonium, alkali metal, or alkali earth metal;
• and
• X is selected from COOM, PO(OM).sub.2 and SO.sub.3 M wherein M is as defined before.