| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid coolant composition not only capable of inhibiting or preventing discoloration of an aluminum material but also excellent in rust proof properties. SOLUTION: This composition comprises a freezing point depressant containing as an effective component at least either one of alcohols and glycols, a rust proof agent and further a barium compound. The ratio of the barium compound is 0.0001-0.05 wt.% in terms of the barium element. The rust proof agent is at least one selected among silicates, phosphates, molybdates, nitrates, tungstates, aromatic monobasic and polybasic carboxylates, aliphatic monobasic and polybasic carboxylates, triazole compounds and thiazole compounds. Further is preferably incorporated at least one selected from sequestering agents comprising a carboxylic acid or a salt thereof to an amino nitrogen, polyphosphoric acids and polycarboxylic acid type polymers. |
