Abstract: Disclosed are coolants comprising brazed metal corrosion inhibitors. In one embodiment, the disclosed brazed metal corrosion inhibitor will comprise a polycarboxylic acid functional compound having the structure: wherein R1, R2, R3, and R4 are each independently selected from the group consisting of H, OH, COOH, C1-C10 alkyl groups, glycol esters, anhydride groups, —COOM, and combinations thereof, wherein M is at least one of H, alkali metal ions, alkali earth metal ions, NH4+, amines, imidazoline, polyalcohol esters, C1 to C12 alkyl groups, and combinations thereof; wherein (1) at least three of R1, R2, R3, and R4 contain the group —COOM, wherein M is defined above; or (2) at least two of R1, R2, R3, and R4 contain an anhydride group, and at least one of R1, R2, R3, and R4 contain the group —COOM, wherein M is defined above.

Abstract: This invention relates to organic acid corrosion inhibitors for use in antifreeze coolant compositions. The corrosion inhibitors comprise a C.sub.8 mono-carboxylic acid component, or isomers and/or salts thereof, and a neo-decanoic acid, or isomers and/or salts thereof. The corrosion inhibitors of this invention provide improved corrosion protection to metal surfaces as compared to conventional inhibitors and provide surprisingly improved corrosion protection as compared to inhibitors containing only a single mono-carboxylic acid component.