SK278773B6 - Non-freezing mixture - Google Patents

Abstract

This patent describes a non-freezing mixture containing 94 up 99 weight percent of monoethylenglycole, 0,0001 up to 0,01 weight percent of silicon oil, 01 up to 3 weight percent of triethanolamine, 0.1 up to 2 weight percent of phosphoric acid, 0,05 up to 0,8 weight percent of 2-merkaptobenzthiazole, 0,05 up to 0,5 weight percent of 1,2,3-benztriazole 0,1 up to 2 weight percent of sodium benzoane, 0,0001 up to 0,1 of N,N'- -disalicylidene-1,2-diaminopropane, 0.1 up to 1 weight percent sodium or potassium hydroxide, while the rest completing 100 percent is water. This non freezing mixture is diluted with water, when applied in the real systems used for heat transfer purposes, so that the solution with concentration 20 up to 60 percent is created, having good properties, when talking about the heat transfer and having good properties closed to corrosion effect as for the construction materials of the for heat transfer purposes is made.

Description

Technical field

The invention relates to an antifreeze composition suitable for use in automotive engine cooling systems and other heat exchange apparatuses.

BACKGROUND OF THE INVENTION

Efficient cooling of internal combustion engines is a prerequisite for their efficient operation. For heat dissipation, cooling systems containing aqueous monoethylene glycol solutions, suitably additive additives, are used as heat transfer medium to improve the desired performance properties.

Cooling systems of internal combustion engines are required as essential properties for good thermal conductivity and sufficient heat capacity, significantly affecting in the circulating cooling system the amount of heat dissipated from the cylinder walls and the head of the engine block. Because of the necessity to work in different climatic conditions, the antifreeze must have a reasonably low freezing point and, in the case of solidification, must not damage the metal parts of the cooling system by volume change, it must form a slurry. The high boiling temperature ensures the function of the charge even in the opposite climatic conditions. At the operating temperature, no bubbles of vapors deteriorating in the heat transfer to the coolant may occur on the hot engine parts, nor in the foam system.

The most widespread feature of cooling systems is their corrosion effect on construction materials, metals, alloys, joints and seals. Furthermore, it is required that the cartridge not smell, be satisfactory in terms of toxicological parameters and, last but not least, be cost-effective.

To meet these demanding requirements, the additives added to the antifreeze must be balanced and form a system providing all the desired performance properties to a satisfactory degree. The refrigerant charge, consisting of monoethylene glycol, water and additives, is essentially a buffer, in which many complex reactions take place during operation, resulting in the formation of corrosion products and conversion of the substances involved. The pH value should not fall below 7 while using the cooling system charge.

Requirements for qualitative parameters of antifreeze mixtures are given by ČSN 66 8910.

Among the substances used as additives to antifreeze mixtures based on monoethylene glycol, mention may be made of organic and inorganic acids such as nitric and phosphoric acids, as well as phthalic, benzoic, sebacic, 3-nitrophthalic and others in the form of salts.

The basic substances used are hydroxides, sodium and potassium, carbonates and acidic carbonates. Organic bases include ethanolamines, in particular triethanolamine, urea, aniline, methylene tetraraamines and other nitrogenous bases. Frequently used additives are salts such as alkali metal nitrates and nitrites, manganese and magnesium, various alkali salts of phosphoric acid, molybdates, alkali metal tungstates, water-soluble alkali metal silicates, borax, as well as salts of organic acids, benzoic, tert-butylbenzoic , clay and others most often in the form of sodium and potassium salts. Of the heterocyclic compounds, benzothiazole derivatives, choline and others are most commonly used. Various organosilicon compounds and silicone oils, surfactants and complexones are also used as additives. The antifreeze compositions contain, in addition to natural ingredients, monoethylene glycol such as diethylene glycol and triethylene glycol, and some of its simplest derivatives include ethylene glycol ethers, 1,2-peopylene glycol and glycerin.

A typical example of a composition for preparing an antifreeze composition for use in automotive technology is the composition of Japanese Patent 63,191,882, cited 10 in Chemical Abstracts 109-24-213. 457k (1988). The composition for preparing the low-setting mixture consists of 95 wt. parts of monoethylene glycol; 5 wt. parts of water; 1.5 wt. a portion of phosphoric acid at a concentration of 85%; wt .; 0.3 wt. a portion of phthalic acid; 15 0.02 wt. a portion of magnesium nitrate; 0.3 wt.

a portion of 2-mercaptobenzothiazole; 0.2 wt. parts of methylbenztriazole; 0.1 wt. a portion of benztriazole; 0.4 wt. a portion of sodium nitrate; 3 wt. parts of sodium benzoate; 0.5 wt. % of sodium molybdate and 1.8 wt. 20 parts potassium hydroxide. Said composition is diluted with water to achieve the desired freezing point of the low solidifying liquid; exhibits improved corrosion resistance properties.

The used antifreeze should not contain nitrates and nitrites, heavy metal compounds for ecological and health reasons and the use of dextirin should also be avoided.

SUMMARY OF THE INVENTION

The present invention provides an antifreeze composition comprising 94 to 99 wt. % monoethylene glycol, 0.0001 to 0.01 wt. % silicone oil, 0.1 to 3 wt. % Triethanolamine, 0.1 to 2 wt. % sodium benzoate, 0.0001 to 0.1 wt. % N, N'-disalicylidene-1,2-diaminopropane, 0.1 to 1 wt. sodium or potassium hydroxide, the remainder being water.

DETAILED DESCRIPTION OF THE INVENTION

The 600 ml beaker contains a thermometer and a pair of electrodes - glass and calomel, connected to a 45 pH meter. The beaker contents are stirred magnetically.

The individual components of the low-setting mixture are dosed into a beaker and after 10 minutes homogenization the temperature and pH values are recorded. The ingredients were dosed in the following order.

500 g of monoethylene glycol (20.8 ° C, pH 5.512); 0.03 g of methyl silicone oil having a specific gravity of 950 kg / m ³ and a viscosity of 200 mPa · s (21.0 ° C, pH 5.553); 2 g of triethanolamine (21.2 ° C, pH 9.961); 2.805 g of 85% by weight phosphoric acid (22.3 ° C, pH 55 3.383); 2.4092 g of a 30% aqueous solution of sodium 2-mercaptobenzothiazole containing 5 wt. sodium hydroxide (23.0 ° C, pH 4.246); 1.0024 g of 1,2,3-benztriazole (23.1 ° C, pH 4.243); 1.5607 g sodium benzoate (23.4 ° C, pH 5.874); 0,2 g of N, N'-di60 salicylidene-1,2-diaminopropane as an 80% solution in toluene (23,7 ° C, pH 5,907) and 4,004 g of a 40% aqueous sodium hydroxide solution (25, 3 ° C, pH 8.510).

The physical chemical properties of the antifreeze composition prepared were compared to the standardized ones

STSEV 2130-80 and ČSN 66 8910 and are listed in the table.

The antifreeze had a pH of 8.0099 before the corrosion test and a pH of 7.9653 after the corrosion test. The alkaline reserve after the corrosion test was 2.33 ml of 0.1 mol / L hydrochloric acid.

The prepared antifreeze was tested for health risk to the extent required by Regulation No. 20/1984 of the Journal of the Ministry of Health of the Slovak Republic dated 1 January 1986. It was found that in the field of general toxicity, namely acute oral toxicity and acute dermal toxicity according to is not toxic, tests for primary skin irritation have shown that the preparation is not irritant. In the field of special toxicity tests, the gene mutation test (Ames test), the chromosome mutation test (micronucleus test), and the DNA damage detection and repair test (reporter test) showed that the preparation was not a mutagen.

Based on these results, the antifreeze can be used in the technical practice for the intended purpose.

Industrial usability

For proper use in real heat transfer systems, the composition according to the invention is diluted with water so as to form, as a rule, 20 to 60 wt. Concentrated solution with good heat transfer properties, showing minimal corrosion effects on heat transfer system construction materials, allowing long-term use with significant economic benefit to the user.

Claims (2)

PATENT CLAIMS The antifreeze comprises 94 to 99 wt. % monoethylene glycol, 0.0001 to 0.01 wt. % silicone oil, 0.1 to 3 wt. % triethanolamine, 0.1 to 2 wt. % phosphoric acid, 0.05 to 0.8 wt. % Of 2-mercaptobenzothiazole sodium, 0.05 to 0.5 wt. % 1,2,3-benztriazole, 0.1 to 2 wt. % sodium benzoate, 0.0001 to 0.1 wt. % N, N'-disalicylidene-1,2-diaminopropane, 0.1 to 1 wt. sodium or potassium hydroxide, the remainder being water.