| abstract |
Disclosed is a coolant comprising a corrosion inhibitor for brazed metals. In one embodiment, the disclosed brazed metal corrosion inhibitor comprises a compound having a polycarboxylic acid functional group having the structure (I), wherein R 1 , R 2 , R 3 , and R 4 is each independently selected from the group consisting of H, OH, COOH, C 1 -C 10 alkyl group, glycol ester, anhydride group, —COOM, and combinations thereof, where M is , H, alkali metal ions, alkaline earth metal ions, NH 4 + , amines, imidazolines, polyhydric alcohol esters, at least one of C 1 -C 12 alkyl groups, and combinations thereof; 1) R 1, R 2, R 3, and at least three of R 4 include a group -COOM, (M in the formula is as defined above); or, (2 R 1, R 2, R 3, and at least two of R 4 forms an anhydride group, R 1, R 2, R 3, and, at least one of R 4 is a group -COOM (Wherein M is as defined above). |