Patent ID: 7641813

Claim:
An antifreeze composition comprising a) a water soluble liquid alcohol freezing point depressant, b) a triazine based compound of formula I, c) a mixture of tolutriazole compounds of formulae II and III, d) 2-ethylhexanoic acid or an alkali metal salt thereof, e) heptanoic acid or an alkali metal salt thereof and f) water, where the compounds of formula I are where Z is a C 1 -C 11 alkylene group, X is hydrogen or an alkali metal, R 1 and R 2 , independently are hydrogen or methyl, R 3 is a group —NR 4 R 5 where R 4 is C 1 -C 12 alkyl or -Z-COOX and R 5 is hydrogen or C 1 -C 12 alkyl; and where the compounds of formulae II and III are where 2-ethylhexanoic acid or its alkali salt together with heptanoic acid or its alkali salt are present from about 20% to about 60% by weight, based on the weight of the composition.