ANTIFREEZING FLUID COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain an antifreezing fluid composition capable of suppressing corrosion of a metal used for cooling systems of internal combustion engines and preventing lowering of pH of whole antifreezing fluid composition over a long period of time. SOLUTION: This composition consists essentially of glycols containing a corrosion inhibitor and further contains 1-7 wt.% 7-9C aliphatic monocarboxylic acid or its alkali metal salt or 9-12C aliphatic dicarboxylic acid or its alkali metal salt and 0.01-2 wt.% benzylimidazole and its alkyl derivative and does not contain an amine salt, a boric acid salt, a nitrous acid salt and a silicic acid salt. Corrosion of metals is suppressed by including the 7-9C aliphatic monocarboxylic acid or its alkali metal salt or 9-12C aliphatic dicarboxylic acid or its alkali metal salt and lowering of pH of whole antifreezing fluid composition is prevented over a long period by including benzylimidazole and its alkyl derivative.