| 摘要 |
PURPOSE: To obtain a coolant compsn. which has a marked effect on corrosion prevention of a metal, esp. common steel, is highly safe, and can be used in applications such as food production by adding a specific compd. to an aq. lower alcohol soln. CONSTITUTION: This coolant compsn. is obtd. by adding a salt of an arom. carboxylic acid and a nitrite to an aq. soln. of a 1-3C aliph. alcohol, pref. ethyl alcohol. The concn. of the alcohol is usually set so that the freezing point of the compsn. is about 10 deg.C lower than the lowest use temp. Suitable concns. of the salt of the carboxylic acid and the nitrite are 0.1-10wt.% and 0.01-5wt.%, respectively, based on the compsn. The compsn. pref. has a pH of 6.0-12.0. Examples of the carboxylic acid are benzoic, p-tert-butylbenzoic, phthalic, isophthalic, and terephthalic acids. If necessary, a glycol may be added as a freezing point depressant. |
