| 摘要 |
FIELD: chemical technology. ^ SUBSTANCE: invention relates to a method for preparing a concentrate of a low-freezing cooling liquid used, in particular, in the cooling systems of internal combustion engines. Method involves dissolving 2-mercaptobenzthiazole in sodium hydroxide aqueous solution in ethylene glycol medium at temperature 40-50°C. Also, method involves separate preparing aqueous-glycol solution of addition agents by successive dissolving sodium phosphate, sodium carbonate, ethylenediaminetetraacetic acid disodium salt and sodium tetraborate in water at stirring at temperature 70-80°C in ethylene glycol medium followed by addition of early prepared 2-mercaptobenzthiazole and aqueous-glycol solution of addition agents, froth breaker and dye to the main amount of ethylene glycol. Method provides enhancing quality of the end product, decreasing the process time and enhancing output of device. ^ EFFECT: improved preparing method. ^ 1 ex |
