Coolant

One of the most common (and most effective as a coolant) coolants is ordinary water, in particular soft , distilled or deionized water that does not leave scale. The advantages of water as a coolant are, in particular, high specific heat, low viscosity , high fluidity , affordability and low price. However, water has corrosive activity in relation to many metals (more precisely, it is not water in itself that possesses corrosive activity, but a weak electrolyte formed due to its impurities that provokes electrochemical corrosion ) and also tends to freeze at a negative temperature to form continuous ice monolith, which, due to the increase in volume during freezing, can seriously damage the engine water jacket and radiators. Therefore, at present, as a rule, special coolants are used, the basis of which is still the same water, but with functional additives (additives) that increase its operational characteristics.

Coolants (coolants) fall into two broad categories - summer coolants and winter (low-freezing) coolants , also known as antifreezes . Currently, the performance of antifreezes has increased to such an extent that in countries with a temperate and cold climate they are often used for year-round operation of vehicles.

Summer coolants are designed for use in the warmer months, as well as in warm, frost-free climates. In most cases, they are distilled or deionized water with the addition of a package of corrosion inhibitors (usually produced in the form of a concentrate in place of added to the water).

A low-freezing coolant (antifreeze) consists of water, usually also distilled or deionized (about half of the composition), a low-freezing component - in most cases, ethylene glycol , and special additives ( corrosion inhibitors ) that compensate for the corrosive activity of water and ethylene glycol. By and large, ethylene glycol coolants of different grades differ from each other only in the percentage between water and ethylene glycol, which determines the temperature of crystallization onset, as well as in the composition of the additive package, the latter often being used as standard, produced by large chemical concerns such as BASF . However, the quality of raw materials plays a role, in particular, the degree of purity of water and ethylene glycol. In the cheapest coolants, instead of monoethylene glycol, its surrogates can be used - diethylene glycol and other polyglycols, which have poorer chemical stability and therefore have a low service life. Propylene glycol is currently being introduced as a replacement for ethylene glycol. Propylene glycol antifreezes are less toxic, but their production is more expensive, and they have a lower boiling point.

Along with this, almost all aqueous solutions of inorganic salts ( sodium chloride, potassium chloride, calcium chloride ), aniline , alcohols , glycerin , glycols , cellosolves , carbitols , etc. can be used to impart low-temperature coolant properties. One of the best antifreezes is 40- degree ethyl alcohol , which spread in such as has occurred due to the high cost, volatility, flammability and expressed psychoactive properties , cause mass poisoning personnel fleets x (even in the form of methylated spirits ). Cheaper methyl alcohol was also used as part of some antifreezes, but its high toxicity turned out to be a big problem, combined with high volatility and fire hazard common to all monohydric alcohols.

All ethylene glycol-based coolants are also very toxic when taken orally (the lethal dose for pure ethylene glycol is approximately 2 ml / kg body weight for an adult). In case of poisoning, glycol antifreeze acts on the central nervous system , causing loss of coordination, weakness, and vomiting. The first symptoms of ethylene glycol poisoning are similar to alcohol poisoning, but after 20 ... 30 minutes they are replaced by loss of consciousness and convulsions; in severe poisoning in the absence of treatment, death occurs after 13-20 days. Treatment is similar to methanol poisoning. Since ethylene glycol coolants taste sweet, children and pets are most at risk of poisoning. In the United States , for example, in several states, manufacturers are required to add bitter flavors to antifreeze. It should be noted that antifreeze vapors are also of particular danger, for example, those entering the cabin in the presence of leaks in the radiator of the heating system or its faucet, and which can cause chronic poisoning. With such chronic inhalation poisoning, eye and upper respiratory tract irritation, lethargy, and drowsiness are observed. Inhalation poisoning usually does not pose a danger to life; treatment is a general strengthening therapy (vitamins, intravenous glucose, etc.).

"Antifreeze" is a trade designation of non-freezing coolant developed in the USSR , although at present this word has already become a household word. Ethylene glycol is used as antifreeze in Tosol. TOSOL is intended for cooling car engines at any time of the year within the temperature indicated in the brands. The numbers 40 and 65, which are in the Tosol brands, mean the beginning of the freezing temperature of the brand. The lowest freezing point of the ethylene glycol-water system is around −70 ° C.

Externally, the standard TOSOL-40 is a blue liquid, TOSOL-65 is red. Color is necessary to determine a clear coolant level in the expansion tank so as not to confuse different brands, and also to distinguish smudges of coolant from smudges of other operating fluids. A change in the color of the coolant during operation signals a loss in the operational properties of the coolant and the need to replace it: after a certain period of operation, TOSOL becomes blue-green, then green, yellow and, finally, becomes discolored. A colorless liquid (and without the addition of dye, glycol antifreeze is colorless) would work no worse than a colored one, from the point of view of the coolant, the dye has no functional load. Nevertheless, a color change signals the aging of the liquid, in particular, the development of corrosion inhibitors contained in it, which significantly reduces its performance. The speed of color change depends on the operating temperature of the coolant: when the engine is overheated - about 105 ° C and above - TOSOL can turn yellow already after 500 hours of operation or less, while at normal operating temperature - about 95 ° C - it changes color to green only after 500-600 hours and remains so for a long time.

The developers of the Tosola recipe were Alexei Vasilievich Borisov and Oscar Naumovich Dyment. The developers of the production technology and the organizers of its production are Evgeny Borisovich Chizhov and Mark Petrovich Shatalov. The authors of the trade name are Kiryan Boris Vladimirovich and Chizhov Evgeny Borisovich. Corrosion tests conducted Tikhonov Yuri Vladimirovich.

Title

The word "TOSOL" is derived from the abbreviation "TOS" - "Technology of Organic Synthesis", a department of the Research Institute of Organic Chemistry and Technology , where the creators worked, and the ending "-ol" used to denote alcohols ( ethylene glycol is a dihydric alcohol). For example: " ethanol " - ethyl alcohol , "ethane-1,2-di ol " - ethylene glycol. According to another version, “OL” is the abbreviation of the Separate Laboratory that developed the substance.

• GOST 28084-89 (Russian Federation)
• BS 6580: 1992 (UK)
• SAE J 1034 (USA)
• ASTM D 3306 (USA)
• ONORM V5123 (Austria)
• AFNOR NF R15-601 (France)
• CUNA NC956 16 (Italy)
• JIS K2234 (Japan)