RU2370513C1 - Antifreeze - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: antifreeze contains sodium nitrite 0.1-0.2 wt %, sodium nitrate 0.2-0.3 wt %, sodium salt of 2- mercaptobenzothiazole 3.0-4.0 wt %, ethanolamine borate 2.0-4.0 wt %, ethyleneglycol 50.0-60.0 wt % and water - the rest.

EFFECT: improved protective properties of the antifreeze towards steel, cast-iron and aluminium.

1 cl, 4 tbl

Description

The invention relates to antifreezes - low-freezing coolants and can be used to cool internal combustion engines (ICE) of cars, agricultural machinery, special equipment, and also as a coolant in heat exchangers.

The liquids used in the cooling system of the internal combustion engine of automotive vehicles are subject to stringent requirements for the lower limit of the operating temperature, as well as for the corrosive and chemical effects on metal and rubber engine parts.

Known antifreeze, including, wt.%: Ethylene glycol 93.0-93.5, alkali metal benzoate 2.90-3.10, alkali metal salicylate 0.08-0.12, alkali metal hydroxide 0.20-0.30 , sodium tetraborate (anhydrous) 0.65-0.75, cyclohexanone 0.28-0.32, alkali metal salt of 2-mercaptobenzthiazole 0.01-0.02, benzotriazole 0.27-0.28, N-benzylidenecyclohexylamine 0 , 28-0.32, alkali metal nitrite 0.15-0.20, silicone defoamer 0.02-0.03, dye 0.0015-0.035 and the rest of the water (RU 2050396 C1, class C09K 5/10, C23F 11/12, 11/14, 12/20/1995).

The disadvantage of this antifreeze is a multicomponent complex composition, including 9 anticorrosion additives with their total content from 4.82 to 5.41 wt.%, Which greatly complicates the technology for producing coolant.

The closest analogue of the proposed technical solution is antifreeze, including, wt.%: Sodium nitrite 0.1-0.2, sodium nitrate 0.1-0.2, sodium benzoate 0.5-5.0, sodium tetraborate 0.1 -0.5, hexamethylenediamine phosphate 0.1-5.0, benzotriazole 0.20 or 2-mercaptobenzthiazole sodium salt (captax) 0.80-0.95, ethylene glycol 79.8-98.1 and the rest water. If necessary, an antifreeze and a dye are introduced into the antifreeze composition (application of Great Britain No. 1397792, class C09K 5/00, 06/18/1975).

The disadvantage of this composition is that it is quite aggressive towards ferrous metals and aluminum.

The technical result of the invention is to increase the protective properties of antifreeze in relation to steel, cast iron and aluminum.

This result is achieved in that the antifreeze, including sodium nitrite, sodium nitrate, sodium salt of 2-mercaptobenzthiazole, ethylene glycol and water, additionally contains ethanolamine borate in the following ratio, wt.%:

Sodium nitrite 0.1-0.2 Sodium nitrate 0.2-0.3 2-mercaptobenzthiazole sodium salt 3.0-4.0 Ethanolamine Borate 2.0-4.0 Ethylene glycol 50.0-60.0 Water Rest

A distinctive feature of the proposed technical solution is that the introduction of ethanolamine into the borate at the stated ratio of the components allows to obtain antifreeze with high protective properties in relation to ferrous and non-ferrous metals.

Ethanolamine borates (BEAs) are the products of the reaction of boric acid with mono-, di- or triethanolamine. Monoethanolamine borate (BMEA) is prepared according to the following scheme:

H ₂ NCH ₂ CH ₂ OH + H ₃ BO ₃ → H ₂ NCH ₂ CH ₂ OB (OH) ₂ .

Diethanolamine borate (BDEA) is prepared according to the scheme:

HN (CH ₂ CH ₂ OH) ₂ + H ₃ BO ₃ → HN (CH ₂ CH ₂ O) ₂ BOH.

Triethanolamine borate (BTEA) is prepared according to the scheme:

N (CH ₂ CH ₂ OH) ₃ + H ₃ BO ₃ → N (CH ₂ CH ₂ O) ₃ B.

The introduction of BEA in the composition of antifreeze in an amount of less than 2.0 wt.% Does not significantly increase the anticorrosive properties of the liquid in relation to ferrous metals. The introduction of BEA in an amount of more than 4.0 wt.% Is impractical, since there is no further increase in protective properties.

The technology for obtaining BEA is as follows.

In a flask equipped with a mechanical stirrer, a thermometer and a Dean-Stark nozzle, 2 moles of EA (121 g of MEA, 210 g of DEA or 298 g of TEA) are loaded. After heating the EA to 100-110 ° C, 62 g (1 mol) of boric acid is introduced into the flask and a condensation reaction is carried out at a temperature of 160-180 ° C until the water evolution ceases. After cooling to 70-80 ° C, 132 g of water are added to the resulting product. Ethanolamines borates are clear, light yellow solutions with a pH of 10-11 and an amine number of 185-195 mg HCl / g.

The technology for preparing antifreeze is as follows.

The calculated quantities of water (softened), sodium nitrite and sodium nitrate, BEA, obtained as described above, and the 2-mercaptobenzthiazole sodium salt (TU 113-00-05761631-23-91) are successively loaded into a container with a stirrer. After stirring for 10-15 minutes, ethylene glycol is added to the resulting aqueous solution, and the mixing process is continued for another 30-40 minutes. If necessary, any neutral dyes can be added to the antifreeze composition, in particular, Na-fluorescein for light green color and others.

The compositions of the antifreeze samples are presented in table 1.

Tests of liquids for corrosion on metals at 88 ± 2 ° С for 336 h were carried out according to the methods described in GOST 28084-89, which are in full accordance with ASTM methods.

The results of corrosion testing of the compositions of the proposed antifreeze in comparison with the composition of the prototype are presented in table.2.

Tests of rubber for swelling in the proposed antifreeze was carried out according to GOST 9.030 at a temperature of 100 ° C for 70 hours

The results of the rubber test for swelling are given in table.3.

The main physico-chemical properties of the proposed antifreeze are given in table 4.

The use of the proposed antifreeze in internal combustion engines of automotive, agricultural and special equipment will protect components and components of internal combustion engines made of ferrous and non-ferrous metals from corrosion damage.

Table 1
The compositions of the proposed antifreeze Components The content of the components according to the examples, wt.% one 2 3 four 5 Sodium nitrite 0.10 0.15 0.20 0.05 0.25 Sodium nitrate 0.20 0.25 0.30 0.15 0.35 Captax 3.0 3,5 4.0 2.5 4,5 BMEA 4.0 - - - 4,5 BDEA - 3.0 - 1,5 - BTEA - - 2.0 - - Ethylene glycol 60.0 55.0 50,0 45.0 65.0 Water 32,7 38.1 43.5 50.8 25,4

table 2
Antifreeze Corrosion Test Results The composition of antifreeze Material copper brass solder cast iron steel aluminum Weight loss, g / m ² . day Example 1 0,03 0.04 0.05 0,03 0.02 0.05 Example 2 0.02 0,03 0.04 0.02 0.01 0,03 Example 3 0,03 0.04 0.04 0,03 0.02 0,03 Example 4 0.05 0.04 0.06 0.09 0,07 0.09 Example 5 0.04 0,03 0.05 0.04 0.04 0.06 Prototype 0.05 0.04 0.06 0.1 0.09 0.08 Requirements GOST 28084-89 no more than 0.1 no more than 0.1 no more than 0.2 no more than 0.1 no more than 0.1 no more than 0.1

Table 3
Rubber test results for swelling in antifreeze Indicators The value of the indicator for examples Prototype GOST norm one 2 3 four 5 Rubber swelling,%: standard samples of rubber grade 57-5006
standard samples of rubber brand 57-7011 1,6 1.3 1.4 2.2 1.7 3,5 no more than 5 1,1 0.9 1,0 1,5 1,2 2.7 no more than 5

Table 4
The main physico-chemical properties of the proposed antifreeze Indicator Antifreeze with BMEA Antifreeze with BDEA Antifreeze with BTEA Density at 20 ° C, g / cm ³ 1,070 1,072 1,076 Boiling point at a pressure of 110.3 kPa (760 mm Hg), ° C 107.5 109 110.5 Hydrogen index (pH) at a temperature of 20 ° C 10.1 10.0 9.0 Alkalinity reserve, cm ³ 23.5 23.1 20.3 The temperature of the onset of crystallization, ° C -40 -43 -44

Claims (1)

Antifreeze, including sodium nitrite, sodium nitrate, sodium salt of 2-mercaptobenzthiazole, ethylene glycol and water, characterized in that it additionally contains ethanolamine borate in the following ratio, wt.%:
Sodium nitrite 0.1-0.2 Sodium nitrate 0.2-0.3 2-mercaptobenzthiazole sodium salt 3.0-4.0 Ethanolamine Borate 2.0-4.0 Ethylene glycol 50.0-60.0 Water Rest