FIELD: protection of metals from corrosion in heat exchange systems.
SUBSTANCE: corrosion inhibitor formulations for use in heat transfer fluids comprise: (a) optionally substituted benzoic acid or a salt thereof; (b) at least a first n-alkylmonocarboxylic acid or a salt thereof and a second n-alkylmonocarboxylic acid or a salt thereof, wherein the first n-alkylmonocarboxylic acid and the second n-alkylmonocarboxylic acid are different; and (c) an azole compound. The weight percent ratio of the first n-alkyl monocarboxylic acid or salt thereof to the weight percent of the second n-alkyl monocarboxylic acid or salt thereof ranges from about 1:0.75 to about 1:2.00. The ratio of the weight percent of benzoic acid or salt thereof to the combined weight percent of the first n-alkyl monocarboxylic acid or salt thereof and the second n -alkyl monocarboxylic acid or salt thereof ranges from about 1:0.30 to about 1:2.25.
EFFECT: simultaneous provision of effective protection against corrosion both for compacted graphite cast iron and aluminium alloys.
41 cl, 11 tbl, 24 ex
