RU2751879C2 - Automotive coolant formulation - Google Patents

Abstract

FIELD: petrochemistry.

SUBSTANCE: invention relates to the field of petrochemistry, namely to coolants and antifreezes intended for use as heat carriers in heat exchangers and in cooling systems of internal combustion engines. An automotive coolant is proposed, including (the content is indicated in wt %): ethylene glycol or a mixture of ethylene glycol with di -, triethylene glycol and/or glycerin 45,490-91,570; anti-foaming agent (polydimethysiloxane with a viscosity of 50 to 500 mm²/s) 0.002-0.004 and/or defoamer Laprol PD-1 0,002-0,004; pH indicator of a number of fluoronic dyes and/or cemactives T 0.0007-0.0013; as anticorrosive additives: dibasic organic acid from the series butanedioic, pentanedioic, hexanedioic, heptanedioic, octanedioic, nonanedioic, decanedioic, and / or a mixture thereof, and/or monobasic organic acid from the series pentanoic, hexanoic, heptanoic, 2-ethylhexanoic, octanoic and/or benzoic acid or a mixture of these acids 2.090-4.480; molybdenum-containing salts of alkali metals from the series sodium molybdate, lithium molybdate, potassium molybdate and/or ammonium molybdate or a mixture of them 0.150-0.315;alkali metal hydroxides from the series sodium hydroxide, lithium hydroxide, potassium hydroxide or a mixture of 0.960-1.930; alkali metal metasilicates from the series sodium metasilicate, potassium metasilicate 0.013-0.035; alkali metal nitrites from the series sodium nitrite, potassium nitrite and/or ammonium nitrite 0.08-0.200; trilon B (disodium salt of ethylenediaminetetraacetic acid) 0.0015-0.005 and/or OEDF 0.0015-0.005; benzotriazole and/or its derivatives 0.250-0.640; water 0.0-51.430.

EFFECT: reduced corrosion activity when using automotive coolant.

1 cl, 2 tbl

Description

The invention relates to the field of petrochemistry, namely to coolants and antifreezes, intended for use as heat carriers in heat exchangers and in cooling systems of internal combustion engines.

Automotive coolant TITAN HD contains an aqueous solution of monoglycols and / or polyglycols and / or polyhydric alcohols of various compositions, an antifoam agent, which is used as polydimethylsiloxanes with different viscosities and / or polyester obtained by polymerizing ethylene oxide in the presence of mono- and / or dipropylene glycols, propanediols , butanediols, pH indicator - from a number of fluorone dyes and / or cements T, as anticorrosive additives - a mixture of organic dibasic and / or monosonic acids, a highly effective corrosion inhibitor, which is a mixture of methanol, secondary fatty alcohols and ketones of fraction C ₁₀ - C ₁₃ , which is the product of liquid-phase oxidation of the fraction of n-alkanes C ₁₀ -C ₁₃ and / or molybdenum-containing salts of alkali metals and / or hydroxides of alkali metals and / or metasilicates of alkali metals and / or nitrites of alkali metals, and disodium salt of ethylenediaminetetraacetic acid and / or HEDP, and benzotriazole and / or its products one with the following ratio of components, expressed in mass%: ethylene glycol or a mixture of ethylene glycol with di-, triethylene glycol and / or with glycerin 45.490-91.570; antifoam agent (polydimethysiloxane with a viscosity of 50 to 500 mm ² / s) 0.002-0.004 and / or antifoam agent Laprol PD-1 0.002-0.004; pH indicator from a number of fluorone dyes and / or cements T 0.0007-0.0013; as anticorrosive additives: dibasic organic acid from the range of butanedioic, pentanedioic, hexanedioic, heptanedioic, octanedioic, nonanedioic, decanedioic and / or their mixture and / or monobasic organic acid from the range of pentanoic, hexanoic, heptanoic, 2-ethylhexanoic and / or octane benzoic acid or a mixture of these acids 2.090-4.480; a highly effective corrosion inhibitor, which is a mixture of methanol, secondary fatty alcohols and ketones of the C ₁₀ -C ₁₃ fraction, which is the product of the liquid-phase oxidation of the C ₁₀ -C ₁₃ 0.000-0.001 n-alkane fraction; molybdenum-containing alkali metal salts from the series sodium molybdate, lithium molybdate, potassium molybdate and / or ammonium molybdate, or a mixture thereof 0.150-0.315; alkali metal hydroxides from the series sodium hydroxide, lithium hydroxide, potassium hydroxide or a mixture thereof 0.960-1.930; alkali metal metasilicates from the series sodium metasilicate, potassium metasilicate 0.013-0.035; alkali metal nitrites from the series sodium nitrite, potassium nitrite and / or ammonium nitrite 0.08-0.200; Trilon B (disodium salt of ethylenediaminetetraacetic acid) 0.0015-0.004 and / or HEDP 0.0015-0.005; benzotriazole and / or its derivatives 0.250-0.640; water 0.0-51.430. Due to the specified composition of the components, a decrease in the crystallization temperature, an improvement in the anti-corrosion properties of the coolant and an increase in the alkalinity reserve are achieved, which makes it possible to ensure a high service life of the coolant without replacement, equal to 450-500 thousand km of run.

EFFECT: automobile coolant has a lower crystallization temperature, lower corrosivity, a large reserve of alkalinity, and, as a consequence, a longer service life. The technical result is achieved through strict adherence to the qualitative and quantitative composition of the coolant.

The invention relates to the field of chemical technology, in particular to compositions of low-freezing coolants (coolant), intended for cooling systems of internal combustion engines, as well as used as heat carriers in heat exchangers and thermal control systems operated at low and moderate temperatures.

In the 20s of the XX century, the first low-freezing coolant appeared, called antifreeze. The first coolant, antifreeze, was made on the basis of glycerin. High viscosity and insufficient fluidity of this type of coolant became a problem.

A mixture of ethylene glycol with water is highly corrosive and tends to foaming, so various additives are added to the coolant.

At the moment, the composition of the most common antifreezes is a mixture of components:

The basis of antifreeze is a glycol-water mixture, which depends on: the ability of antifreeze not to freeze at low temperatures, its specific heat capacity, viscosity and impact on rubber. In Russia, the most common coolants based on ethylene glycol. But its aqueous solution is aggressive to the materials of the cooling system parts (steel, cast iron, aluminum, copper, brass, solder).

A complex of additives: anticorrosive (inhibitors), antifoam and stabilizing.

The term for replacing the coolant, depending on its class, is as follows:

1) Classic (traditional) antifreeze - 50-75 thousand km. or 1-2 years of operation

2) "Hybrid" coolants - 100-150 thousand km. or 2-3 years of operation

3) Carboxylate coolants - 200-250 thousand km. or 3-5 years of operation.

Glycol-based coolant compositions are widely found in the patent literature.

In the patent of the European Patent Convention [Antifreeze composition: US Pat. 0299942 EP. No. 88870108.3, MKI C09K 5/00, app. 06/16/1988; publ. 12/02/1992; Bul. No. 92/49] describes the formulation of automotive antifreeze, consisting of a glycol component (including glycerin), both separate and their mixture, water in a mass ratio from 98: 2 to 10:90, 0.5-3% phosphoric acid and / or its salts. As other additives to improve the properties of automotive antifreeze, the authors propose the following components: manganese compounds, for example, oxide, hydroxide, acids, permanganates of alkali and alkaline earth metals, manganese salts in an amount of 0.005-0.02%; magnesium compounds, including oxide, hydroxide, magnesium salts in the amount of 0.005-0.05%; aromatic polyacids, including phthalic, isophthalic, terephthalic, hemimellite, trimellite, etc. in an amount of 0.1-0.5%, depending on the content of the glycol component; aliphatic dibasic organic acids, for example, adipic, sebacic, etc. in an amount of 0.1-0.7%; as well as molybdates (0.3-0.7%), tungstates (0.3-0.7%); and some other components, including polymeric ones. This patent describes the test methods for the obtained antifreeze and the results confirming the possibility of its use in automobile engines.

In the patent of the European Patent Convention [Antifreeze / coolant composition: US Pat. EP 1281742. No. 00993852.3, MKI C09K 5/00, app. 03/23/2000; publ. 02/05/2003; Bul. No. 2003/06] describes the formulation of glycol-based automotive antifreeze using both individual components and a mixture of glycol components. Dibasic aliphatic acids (0.1-8%), alkali metal salts (0.1-10%), triazole are used as additives.

For this formulation, numerous studies on corrosiveness have been carried out, experiments have shown the possibility of using this antifreeze in automobile engines.

In the patent [Process for producing an antifreeze composition containing lower alcohols and glycerol via alcoholysis of a glyceride: Pat. 2298721 EP. No. 10184192.2, MKI C09K 5/00; app. March 24, 2005; publ. 03/23/2011; Bul. No. 2011/12], presents a composition for use as an antifreeze, an anti-icing agent, which is obtained from crude glycerin, glycerides of alcohols C1-C4, in which the content of glycerin is 0.5% -60% and 20% -85% of propylene glycol.

Tests of this composition for compliance with the requirements of regulatory documents showed satisfactory results.

In the patent [Engine coolant additive: US Pat. EP 2778208. No. 14159350.9; MKI C09K 5/00, app. 03/13/2014; publ. 09/17/2014; Bul. No. 2014/38], described additives to the coolant containing :, salts of a monobasic carboxylic acid; azole salts; water, in an amount not exceeding about 25-35% by weight, based on the total weight of the coolant additive.

Engine coolant formulations are usually a mixture of the main component, ethylene glycol, glycerin and water, and minor amounts of other components such as silicates, phosphates, nitrates, borates, molybdates, organic acids and azoles. Typically, these other components are present in the coolant in the form of salts, so the composition generally has a pH of 7 or higher, up to 14.

Engine parts are made of ferrous metals, which are in contact with coolants, including, therefore, a pH greater than 7 facilitates the formation of a protective film on the surface of the ferrous metal.

It should also be noted that one of the components of the group are borates, for example, borax (Na ₂ B ₄ O ₅ (OH) ₄ ⋅8H ₂ O), which has an acidic pH at low water contents, but forms an alkaline buffer solution as the water content.

Antifreeze additives also include corrosion inhibitors, colorants, defoamers, surfactants, depressants, and biocides.

Some of these components are solids that must be dissolved in, for example, coolant.

Corrosion inhibitors prevent pitting and other forms of corrosion that can significantly shorten engine life.

The main component of the coolant can be obtained in various ways, while sometimes unique and difficult methods are required to obtain various additives, therefore additives make a significant contribution to the cost of a commercial product.

An additive to a coolant is considered, in which a salt of a monobasic carboxylic acid is present, 40-70% of the mass. from the total weight of the additive added, and the amount of this component varies depending on the molecular weight of the carboxylic acid. As carboxylic acids suitable for this formulation, acids from the following series are used: hexanoic, heptanoic, isoheptanoic, octanoic, 2-ethylhexanoic, nonanoic, neononanoic, decanoic, undecanoic, dodecanoic, neodecanoic, as well as their combinations.

Triazoles of various compositions are used as the azole component. The content of the azole component varies in the range from 1 to 10% of the mass.

A specific formulation of the coolant additive is proposed: potassium hydroxide (45% solution) 402.7 g; 2-ethylhexanoic acid 483.2 g; sodium tolyltriazole (in 50% aqueous sodium hydroxide solution) 40.25 g; 50% aqueous NaOH solution 80.5 g; sodium molybdate 31.3 g; Plurafac® LF 224 1.52 g; Silbreak 320 0.78 g.

In the patent [Antifreeze composition: US Pat. 2174220. # 228574; MKI C09K 5/00, app. 09/06/1938; publ. 09/26/1939] describes a coolant containing ammonium chloride (1 part by weight), sodium carbonate (1 part by weight), glycerin (2-3 parts by weight), water (4-6 parts by weight), sodium hydroxide ( to pH = 7.0). It was found that this composition has a freezing point of -10 ° C.

In the patent [Antifreeze composition: US Pat. 2200184 US. No. 235959; MKI C09K 5/00, app. 10/20/1938; publ. 05/07/1940] describes the formulation of automotive antifreeze, where along with the above components to reduce the freezing point of antifreeze, special additives are used - ethanolamine components. It was found that the addition of monoethanolamine chloride decreases the freezing point to -20 ° C.

A recipe containing 0.5-5% of ethylene glycol in a mixture with glycerin monoricinoleate and / or ethylene glycol freed from soap, as well as a set of additives to achieve the required antifreeze properties is described in the patent [Antifreeze composition: US Pat. 2386182 US. No. 454195; MKI C09K 5/00, app. 08/08/1942; publ. 10/09/1945].

Antifreeze based on glycerin is also discussed in the patent [Antifreeze composition: US Pat. 4455248 US. No. 546081; MKI C09K 5/00, app. 10/31/1983; publ. 06/19/1984]: for its preparation mix 100 masses, parts of glycerin, 0.1-500 masses. parts of water, 0.1 mass. part of sodium metasilicate, 1.6-2.2 wt. parts of potassium phosphate, 0.15-0.5 wt. parts of boron-containing salts of alkali metals, 0.1-0.4 wt. part of sodium nitrate, as well as a set of anti-corrosion additives, in particular tolyltriazole, benzotriazole, mercaptobenzotriazole. In this case, the pH of the antifreeze is 9.0-11.5.

Buffer mixtures, anticorrosive additives, defoamers are described in the patent [Organophosphate-containing antifreeze: US Pat. 4613445 US. No. 633210; MKI C09K 5/00, app. 07/23/1984; publ. 09/23/1986]. Borate and phosphate are used as buffer mixtures. Benzoic acid, dibasic organic aliphatic acids, and combinations of components are added to achieve the desired pH and alkalinity. It is proposed to use organic phosphorus compounds as corrosion inhibitors, in particular, phosphoric acid esters.

In the patent [Metal corrosion inhibitive coolant composition containing alkenylsuccinic acid or alkali metal salt thereof: US Pat. 5851419 US. No. 08/829528; MKI C09K 5/00, app. 03/28/1997; publ. 12/22/1998] the authors disclose the composition of a coolant containing derivatives of succinic acid, in combination with derivatives of benzoic acid, to ensure corrosion resistance and a satisfactory pH and alkalinity.

In the patent [Hydroxybenzoic acid as pH buffer and corrosion inhibitor for antifreeze containing organosiloxane-silicate copolymers: US Pat. 4241016 US. No. 06/082705; MKI C09K 5/00, app. 10/09/1979; publ. 12/23/1980] describes a method for inhibiting corrosion of metals, in particular aluminum, using hydroxybenzoic acid as corrosion inhibitors in combination with organosiloxane copolymer at pH from 9 to 11.

In the patent [Orthosilicate ester containing heat transfer fluids: US Pat. 4460478 US. No. 06/430374; MKI C09K 5/00, app. 09/30/1982; publ. 07/17/1984] shows the composition of a coolant containing an ester of orthosilicate with a pH of 6 to 8, containing from 25 to 4000 ppm of silicon. It is proposed to use hydroxybenzoate as a corrosion inhibitor.

In the patent [Corrosion-inhibited antifreeze / coolant composition: US Pat. 5085793 US. No. 07/615763; MKI C09K 5/00, app. 11/19/1990; publ. 02/04/1992] describes the composition of antifreeze, in which hydroxybenzoates are used for corrosion protection. Antifreeze consists of a glycol component, which can be either glycerin or a monobasic aromatic carboxylic acid with a carboxyl group near hydroxyl radicals. This patent also discloses a method for inhibiting metal corrosion. The corrosion inhibitor is a hydroxybenzoate and at least one component from the group of borates, silicates, benzoates, nitrates, nitrites, molybdates, thiazoles and aliphatic diacids or their salts.

In the patent [Liquid coolant compositions with anti-corrosive property containing magnesium and calcium compounds: US Pat. 5718836 US. No. 08/559199; MKI C09K 5/00, app. 11/13/1995; publ. 17.02.1998] describes the composition of the coolant containing calcium and / or magnesium salts, and other corrosion inhibitors, including benzoic acid.

Patent of the European Convention [Additive for an antifreeze product: US Pat. EP 0348303. No. 19890401784; MKI C09K 5/00, app. 06/23/1989; publ. 12/27/1989; Bul. No. 89/52] describes a corrosion inhibitor that has shown itself well when working at elevated temperatures - salicylate or acetylsalicylate. The examples show that when exposed to high temperatures, the formation of acids from the main component of antifreeze occurs much faster and the pH decreases. The addition of salicylate seems to suppress the increase in basicity, the pH rises with thermal exposure. Increasing or decreasing the pH below specified limits is undesirable as it corrodes the cooling system.

Patent [Engine antifreeze coolant composition: US Pat. 5387360 US. No. 08/132042; MKI C09K 5/00, app. 10/05/1993; publ. 02/07/1995] discloses the composition of the coolant containing glycols, as the main component, for example, ethylene glycol, propylene glycol, 1,3-butylene glycol, hexylene glycol, diethylene glycol and glycerin. The composition also includes one of the standard non-silicate corrosion inhibitors and about 0.005-0.5% citric acid and / or its corresponding salts.

In the patent [Antifreeze concentrate and coolant compositions and preparation thereof: US Pat. 7790054 US. No. 11/769943; MKI C09K 5/00, app. 06/28/2007; publ. 09/07/2010] the content of the main component from the group of alkylene glycols, glycol ethers, glycerin and their mixtures varies from 50 to 99.8%. It is also proposed to introduce into the composition of antifreeze from 0.1 to 10% wt. branched organic acids (C5-C18) or salts and amines of branched organic acids (C5-C16); substituted aromatic acids (C7-C18) or salts and amines of such acids. In one embodiment, the composition is used in the form of a concentrate in a mixture with water of 10-90% of the mass.

To reduce the freezing point, it is proposed to use depressants from the series: octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, neodecanoic acid, benzoic acid, 2-hydroxybenzoic acid, and mixtures thereof. Also proposed is a method for improving the thermal stability of antifreeze, including mixing the main component with appropriate additives.

The closest in technical essence and the achieved effect is a coolant containing masses. %: 50.0-97.2 ethylene glycol or a mixture of ethylene glycol with di-, triethylene glycol and / or monoalkyl ethers (C ₁ -C ₂ ) of polyoxyalkylene glycols with an average molecular weight of 90-120, 0.5-8.0 sodium tetraborate decahydrate, 0.02-2.5 benzotriazole and / or its derivatives, and / or sodium or potassium salt of 2-mercaptobenzthiazole, 0.05-4.5 hydroxide and / or carbonate of an alkali metal, 0.1-7.0 boric, or adipic, or sebacic, or benzoic, or triazinotriyltriiminopolyhexanoic, or 2-ethylhexanoic, or sorbic, or 2-mercaptobenzothiazoyl succinic acids, or a mixture of these acids and 2.0-49.0 water, 0.001-0.02 dye [Cooling liquid: Pat ... 2213119 C2 RF, N 2001123306 A, MKI S09L 5/00, app. 20.08.2001, publ. 07/29/2003].

The technical object of the invention is to provide a coolant with a lower corrosivity, a relatively higher reserve of alkalinity, a lower temperature of the onset of crystallization.

The proposed coolant includes (the content is indicated in% by weight): ethylene glycol or a mixture of ethylene glycol with di-, triethylene glycol and / or with glycerin 45.490-91.570; antifoam agent (polydimethysiloxane with a viscosity of 50 to 500 mm ² / s) 0.002-0.004 and / or antifoam agent Laprol PD-1 0.002-0.004; pH indicator from a number of fluorone dyes and / or cements T 0.0007-0.0013; as anticorrosive additives: dibasic organic acid from the range of butanedioic, pentanedioic, hexanedioic, heptanedioic, octanedioic, nonanedioic, decanedioic and / or their mixture and / or monobasic organic acid from the range of pentanoic, hexanoic, heptanoic, 2-ethylhexanoic and / or octane benzoic acid or a mixture of these acids 2.090-4.480; a highly effective corrosion inhibitor, which is a mixture of methanol, secondary fatty alcohols and ketones of the C ₁₀ -C ₁₃ fraction, which is the product of the liquid-phase oxidation of the C ₁₀ -C ₁₃ 0.000-0.001 n-alkane fraction; molybdenum-containing alkali metal salts from the series sodium molybdate, lithium molybdate, potassium molybdate and / or ammonium molybdate, or a mixture thereof 0.150-0.315; alkali metal hydroxides from the series sodium hydroxide, lithium hydroxide, potassium hydroxide or a mixture thereof 0.960-1.930; alkali metal metasilicates from the series sodium metasilicate, potassium metasilicate 0.013-0.035; alkali metal nitrites from the series sodium nitrite, potassium nitrite and / or ammonium nitrite 0.08-0.200; Trilon B (disodium salt of ethylenediaminetetraacetic acid) 0.0015-0.004 and / or HEDP 0.0015-0.005; benzotriazole and / or its derivatives 0.250-0.640; water 0.0-51.430. Due to the specified composition of the components, a decrease in the crystallization temperature, an improvement in the anticorrosive properties of the coolant and an increase in the alkalinity reserve are achieved, which makes it possible to ensure a high service life of the coolant without replacement, equal to 450-500 thousand km of run.

The claimed coolant differs from the prototype by the introduction of new components (a highly effective corrosion inhibitor, which is a mixture of methanol, secondary fatty alcohols and ketones of the C ₁₀ -C ₁₃ fraction, which is the product of the liquid-phase oxidation of the C ₁₀ -C ₁₃ n-alkane fraction) and a new ratio components. The use of new components in the proposed composition of the coolant (a highly effective corrosion inhibitor, which is a mixture of methanol, secondary fatty alcohols and ketones of the C ₁₀ -C ₁₃ fraction, which is a product of liquid-phase oxidation of the C ₁₀ -C ₁₃ n-alkane fraction) and the found ratio of all ingredients provides such properties that are manifested only in the specified technical solution, namely, lower corrosivity, a relatively higher reserve of alkalinity, a lower temperature of the beginning of crystallization.

To increase the service life of the coolant, it is important that the alkalinity reserve is more than 10 cm ³ . From the data obtained, it follows that the developed coolant has a higher alkalinity reserve (32.9 cm ³ ) compared to the prototype, the alkalinity reserve of which is 8.7-20.8 cm ³ . One of the key characteristics of any coolant is the onset of crystallization temperature, as this parameter determines the temperature limit for the application of the fluid. The lower the crystallization temperature of the coolant, the more versatile it is, since it allows it to be used in a wider temperature range. The experimental data obtained indicate that the developed liquid is characterized by lower crystallization onset temperatures than the prototype. With regard to the corrosiveness of the developed coolant, in comparison with the prototype, there is a significant decrease in the corrosive effect on steel, cast iron and copper under equal conditions for conducting corrosion tests.

Thus, the comparative analysis showed that the developed coolant surpasses the prototype in terms of key primary characteristics. Compared with the prototype, corrosion losses for steel, cast iron and copper are 0.3, 0.3 and 0.8 mg, respectively.

The technology for preparing the proposed coolant consists in dissolving anticorrosive additives, antifoaming agent, pH indicator in water at a temperature of 20-80 ° C, followed by mixing the additive solution with ethylene glycol or a mixture of ethylene glycol with di-, triethylene glycol and / or with glycerin. The resulting mixture is filtered to obtain the finished product. The components included in the formulation of the proposed coolant are not in short supply and are produced industrially.

Determination of the reserve of alkalinity is carried out according to the method ASTM-1121. The pH is measured in 50% solutions of antifreeze samples according to the ASTM-1287 method.

Corrosion tests are carried out on 50% solutions according to the ASTM D-1384 method for 336 hours at 88 ± 1 ° C with air aeration.

Determination of the crystallization onset temperature is carried out in accordance with the ASTM D 1177 method.

Table 1 shows the compositions of the samples of the inventive coolant and in table 2 their properties in comparison with the prototype. From the data in table 2 it can be seen that the proposed coolant has a lower corrosivity, a relatively higher reserve of alkalinity than the prototype, a lower temperature of the onset of crystallization.

Example 1.

Place 50.660 g of water in a container and gradually dissolve 0.002 g of Laprol PD-1, 0.0007 g of Tsemaktiv T-5S, 2.09 g of a mixture of adipic (hexanedioic) and benzoic acids in a ratio of 1.7 / 1, 0.150 g of molybdate sodium and 0.960 g of sodium hydroxide, 0.013 g of sodium metasilicate, 0.080 g of sodium nitrite, 0.0015 g of Trilon B, and 0.250 g of tolyltriazole. Stirred for 1.0 hour at a temperature of 20-40 ° C and then add 45.7978 g of ethylene glycol. Then the mixture is stirred at a temperature of 20-80 ° C for 1.0 h until all components are completely dissolved.

Table 1 (examples 1-19) shows the compositions of the proposed coolant prepared under the conditions described in example 1.

Table 2 shows a comparison of the most corrosion-safe prototype with the proposed coolant.

Thus, the comparative analysis showed that the developed coolant surpasses the prototype in terms of key primary characteristics.

A further increase in the content of anti-corrosive components does not lead to a significant decrease in the corrosive effect of the coolant on metals and alloys, however, it significantly reduces the alkalinity reserve and increases the cost of the product.

An increase in the content of antifoam and antifoam is also economically impractical and degrades the performance properties of the coolant.

Claims (1)

Automotive coolant includes (the content is indicated in% by weight): ethylene glycol or a mixture of ethylene glycol with di-, triethylene glycol and / or with glycerin 45.490-91.570; antifoam agent (polydimethysiloxane with a viscosity of 50 to 500 mm ² / s) 0.002-0.004 and / or antifoam agent Laprol PD-1 0.002-0.004; pH indicator from a number of fluorone dyes and / or cements T 0.0007-0.0013; as anticorrosive additives: dibasic organic acid from the range of butanedioic, pentanedioic, hexanedioic, heptanedioic, octanedioic, nonanedioic, decanedioic, and / or their mixture, and / or monobasic organic acid from the range of pentanoic, hexanoic, heptanoic, 2-ethylhexanoic, 2-ethylhexanoic / or benzoic acid or a mixture of these acids 2.090-4.480; molybdenum-containing alkali metal salts from the series sodium molybdate, lithium molybdate, potassium molybdate and / or ammonium molybdate, or a mixture thereof 0.150-0.315; alkali metal hydroxides from the series sodium hydroxide, lithium hydroxide, potassium hydroxide or a mixture thereof 0.960-1.930; alkali metal metasilicates from the series sodium metasilicate, potassium metasilicate 0.013-0.035; alkali metal nitrites from the series sodium nitrite, potassium nitrite and / or ammonium nitrite 0.08-0.200; Trilon B (disodium salt of ethylenediaminetetraacetic acid) 0.0015-0.005 and / or HEDP 0.0015-0.005; benzotriazole and / or its derivatives 0.250-0.640; water 0.0-51.430.