Field of the Invention The present invention relates to pH-value buffering of heat-transmitting liquids--for example of cooling liquids for waste heat removal in compressors or internal combustion engines, industrial heat exchangers, cooling systems, heating systems, solar heat exchangers, hydraulic liquids and other applications.

Prior Art The purpose of heat-transmitting liquids is to effectively absorb heat energy at one point and transfer it at another point of a system, respective of hydraulic liquids to transmit mechanical power in the form of pressure, all without a loss in the preferred properties of the liquids during an operation. In regards to temperature and environment in which the liquid is placed, it is repeatedly required to have the widest possible range between the freezing point and boiling point, whether during operating or standing conditions. The liquid must also be environmentally friendly in the case of accidental leakage or mechanical failure. A further important property of the liquid is that it cannot corrode the construction materials of the exchanger or hydraulic systems. This capacity is determined by a set of corrosion inhibitors, and the pH-value is an important parameter of the corrosive effect of the liquid. A liquid having pH-value in a range of 7.0 to 9.0 is the most acceptable for construction materials such as copper and copper base alloys, solder, ferrous metals, such as steel and cast iron and aluminum base alloys, the materials which are most frequently used. This value must be retained with a new liquid filling at various dilution ratios, when diluted by deionized, softened, industrial, drinking or hard water, and in long term use. This aim is reached by an application of the materials with a capacity to buffer the pH-value within the mentioned range. For example, alkaline salts of organic alkylcarboxilic or arylcarboxilic acids which simultaneously form effective corrosion inhibitors are applied, but they have a slight buffering capacity. Alkali phosphates, ammonium phosphates or amino phosphates, as well silicones, are not suitable for using in water with a content of calcium and magnesium salts which precipitate phosphates or silicones. Amines, such as alkanolamines or imidazole and corresponding salts, are not suitable in the potential formation of high toxic and carcinogen nitrosamines by a presence of nitrites; borax is not allowed by some manufacturers.

According to patent application internationally published under the number WO 9709332, triethanolaminetriborate may be a component of heat-transmitting or hydraulic liquid ; however, in regard to its physical-chemical properties, it composes an essential portion of the liquid and thus it is not an additive to stabilize the pH-value.

Summary of the Invention The present invention relates to a composition of liquids for energy transmission, especially heat transmission and mechanical power transmission, through pressure, based on water or water solutions of oxa-alkanols, alkane diols, alkane triols, oxa-alkane diols and their derivatives, in which alkaline salts of 1, 3,2-dioxaborolan-2-ol and/or alkaline salts of 1,3, 2- dioxaborinan-2-ol and/or their derivatives and/or their compounds are used to stabilize the pH- value within the range of 7.0 to 9.0. The liquids may further be treated by foaming reductive additives, color indicator substances for visual distinction and significant flavors in order to detect when accidentally digested. The liquids may, if necessary, be used diluted in relation to the required freezing point, heat capacity, viscosity, lubrication power, etc. At present, concentrated liquids and also their diluted solutions are unrestrictedly miscible with generally used cooling and hydraulic liquids, based on ethylene glycol, propylene glycol, and polyglycols, without loss of their utility properties.

From an environmental viewpoint, there is the significant fact that alkaline salts of 1, 3,2-dioxaborolan-2-ol, 1, 3,2-dioxaborinan-2-ol and their derivatives are biodegradable while forming harmless inorganic boron compounds, prevailingly salts of boric acid, carbon dioxide and water. This was proved by biodegradability testing using a sample of the cooling liquid invention carried out by the Institute of Water and Environment Technology at the University of Chemical Technology, Prague, conforming to the methodology of the Ministry of Environment, Part 2/1994 of April 15,1994. The test proved that the material is highly biodegradable. The salts whose anion is in borolane and possibly the borinane ring substituted by at least one hydroxyl group are in this respect of particular advantage.

Description of the preferred embodiments Example 1 A compound has been prepared of : Ethylene glycol 85.32 per cent of mass Water 10.73 Sodium 1, 3,2-dioxaborolan-2-ol 3.04 Sodium diethylhexane acid 0.51 Disodium sebacic acid 0. 38 Benztriazol 0.02 The alkaline reserve of the compound was determined as a consumption of hydrochloric acid, c=0. 1 mol/1 in titration of the solution containing 10 ml of the compound and 90 ml of demineralized water, up to a pH-value of 5.50. Fig. 1 shows a typical titrimetric curve within the range of pH-value 9.0 to 5.5. The curve demonstrates buffering capacity of the compound within a pH-value range of 7.0 to 9.0, required to secure preferred anticorrosive properties. The compound was employed in corrosion tests conforming to ASTM 1384-80 of six metal samples-- copper, solder, brass, steel, cast iron and aluminum base alloy--silumin in all glass apparatus.

The metal samples were exposed continuously for 336 hours to a compound containing 1 part of the compound to 2 parts corrosive water containing sulfate, chloride and hydrogencarbonate ion 100 mg/1 respectively, at a temperature of 88°C, bubbled through with air at 100 ml/min. After mechanical cleaning and removal of chemical residues, the corrosion loss of the sample metal surface was determined as follows, in g per m2 : copper <1 ; solder <2 brass <1 ; steel <1 ; cast iron <3 and aluminum base alloy <2.

Example 2: A compound has been prepared of : 1, 2 propylene glycol 84.29 per cent of mass Water 11. 33 Sodium 4-methyl-1, 3,2-dioxaborolan-2-ol 3.61 Disodium azelaine acid 0.75 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 solder <3 brass <1 steel <1 ; cast iron <1 ; and aluminum base alloy <2.

Example 3: A compound has been prepared of : 1,2 propylene glycol 83.81 per cent of mass Water 11. 28 Sodium 4-methyl-1, 3,2-dioxaborolan-2-ol 4.00 Sodium hexanoic acid 0.89 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 solder <3 brass <1 steel <1 ; cast iron <3 and aluminum base alloy <2.

Example 4: A compound has been prepared of : 1,4-butanediol 82.68 per cent of mass Water 11. 41 Potassium 4, 5-dimethyl-1, 3,2-dioxaborolan-2-ol 4.52 Potasium decanoic acid 1.37 Benzthiazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in the example 1. Metal corrosion loss is, copper < 1, solder < 2, brass < 2, steel < 2, cast iron < 2, aluminum base alloy < 2.

Example 5: A compound has been prepared of : Glycerol 84.45 per cent of mass Water 9.40 Compound of sodium 4- (1, 2,3-trihydroxypropyl)- 5-hydroxymethyl-1,3, 2-dioxaborolan-2-ol and sodium 4, 5-di- (1, 2-dihydroxyethyl)-1, 3,2- dioxaborolan-2-ol in configuration D-galacto--on C6 carbon chain, at a ratio of 1: 99 to 99: 1 5.55 Disoduim suberic acid 0.58 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in the example 1. Course of the titration is shown in Fig. 1, with pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 ; solder <3 brass <1 steel <1 ; cast iron <2 and aluminum base alloy <2.

Example 6: A compound has been prepared of : Glycerol 84.45 per cent of mass Water 9.36 Compound of sodium 4- (1, 2, 3-trihydroxypropyl)- 5-hydroxymethyl-1, 3, 2-dioxaborolan-2-ol and sodium 4, 5-di- (1, 2-dihydroxyethyl) -1,3, 2- dioxaborolan-2-ol in configuration D-manno--on C6 carbon chain, at a ratio of 1: 99 to 99: 1 5.55 Disoduim azelaic acid 0.62 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 solder <2 brass <1 steel <1 cast iron <2 and aluminum base alloy <2.

Example 7: A compound has been prepared of : Glycerol 84. 39 per cent of mass Water 9. 38 Compound of sodium 4- (1, 2,3-trihydroxypropyl)- 5-hydroxymethyl-1, 3,2-dioxaborolan-2-ol and sodium 4, 5-di- (1, 2-dihydroxyethyl)-1, 3,2- dioxaborolan-2-ol in configuration D-gluco--on C6 carbon chain, at a ratio of 1: 99 to 99: 1 5.55 Disoduim suberic acid 0.66 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 solder <2 brass <1 steel <1 ; cast iron <2 and aluminum base alloy <2.

Example 8: A compound has been prepared of : Water 92. 34 per cent of mass Compound of sodium 4- (1, 2,3-trihydroxypropyl)- 5-hydroxymethyl-1, 3,2-dioxaborolan-2-ol and sodium 4, 5-di- (1, 2-dihydroxyethyl)-1, 3,2- dioxaborolan-2-ol in configuration D-manno--on C6 carbon chain, at a ratio of 1: 99 to 99: 1 6.70 Sodium 2-ethylhexanoic acid 0.54 Disoduim sebacic acid 0.40 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 ; solder <3 brass <2 ; steel <2 cast iron <3 ; and aluminum base alloy <2.

Example 9: A compound has been prepared of : Diethylene glycol 84.60 per cent of mass Water 10.65 Compound of sodium 5-hydroxy-1, 3,2- dioxaborinan-2-ol and sodium 4-hydroxymethyl- 1, 3,2-dioxaborolan-2-ol, at a ratio of 1: 99 to 99: 1 3.84 Sodium 2-ethylhexanoic acid 0.51 Disoduim sebacic acid 0.38 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 solder <2 brass <1 steel <1 cast iron <2, and aluminum base alloy <2.

Example 10: A compound has been prepared of : Dipropylene glycol, compound of isomers 83.22 per cent of mass Water 11.40 Compound of sodium 5-hydroxy-1,3, 2- dioxaborinan-2-ol and sodium 4-hydroxymethyl- 1, 3,2-dioxaborolan-2-ol, at a ratio of 1: 99 to 99: 1 3.19 Sodium 2-ethylhexanoic acid 2.17 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 2, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 solder <2 brass <1 ; steel <1 ; cast iron <2 and aluminum base alloy <2.

Example 11: A compound has been prepared of : Ethoxyethanol 82.39 per cent of mass Water 12.38 Compound of sodium 5-hydroxy-1,3, 2- dioxaborinan-2-ol and sodium 4-hydroxymethyl- 1, 3,2-dioxaborolan-2-ol, at a ratio of 1: 99 to 99: 1 3.47 Disoduim sebacic acid 1.74 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of A 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 solder <4 brass <2 steel <2 cast iron <4 and aluminum base alloy <3.

Example 12: A compound has been prepared of : Glycerol 86.18 per cent of mass Water 9.58 Compound of sodium 5-hydroxy-1, 3,2- dioxaborinan-2-ol and sodium 4-hydroxymethyl- 1, 3,2-dioxaborolan-2-ol, at a ratio of 1: 99 to 99: 1 4.22 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 3, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 solder <6 brass <1 steel <1 ; cast iron <6 and aluminum base alloy <2.

Example 13: A compound has been prepared of : Glycerol 86.54 per cent of mass Water 9.61 Sodium 1, 3,2-dioxaborinan-2-ol 3.07 Sodium hexanoic acid 0.76 Sodium mercaptobenzthiazole 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 ; solder <3 brass <1 steel <1 ; cast iron <3 and aluminum base alloy <2.

Example 14: A compound has been prepared of : Ethylene glycol 84.54 per cent of mass Water 10.62 Sodium 4-methyl-1,3, 2-dioxaborinan-2-ol 3. 81 Sodium 2-ethylhexanoic acid 1.01 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of i 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 ; solder <2 brass <1 steel <1 cast iron <2 and aluminum base alloy <2.

Example 15: A compound has been prepared of : Triethylene glycol 84.52 per cent of mass Water 10.52 Sodium 5, 5-dimethyl-1, 3,2-dioxaborinan-2-ol 4.11 Disodium dodecanoic acid 0.83 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 ; solder <3 brass <1 ; steel <1 cast iron <3 and aluminum base alloy <2.

Example 16: A compound has been prepared of : Glycerol 85.48 per cent of mass Water 9.50 Sodium 4-propyl-5-ethyl-1, 3,2-dioxaborinan-2-ol 3.66 Disodium sebacic acid 1.34 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 2, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 solder <2 brass <1 ; steel <1 ; cast iron <1 and aluminum base alloy <2.

Example 17: A compound has been prepared of : Glycerol 85.48 per cent of mass Water 9.50 Sodium 5-hydroxymethyl-5-methyl-1, 3,2- dioxaborinan-2-ol 4.10 Soduim 2-ethylhexanoic acid 0.90 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss in g per m2 of the metal sample surface was as follows: copper <1 solder <3 brass <1 steel <1 ; cast iron <2 and aluminum base alloy <2.

Example 18: A compound has been prepared of : Glycerol 85.19 per cent of mass Water 9.46 Sodium 5-hydroxymethyl-5-ethyl-1, 3,2- dioxaborinan-2-ol 4.43 Soduim n-octanoic acid 0.90 Benztriazol 0.02 The alkaline reserve and buffering capacity of the compound were determined in the same manner as in example 1. The course of the titration is shown in Fig. 1, with a pH-value difference of 0.05. Corrosion tests were carried out as in example 1. The metal corrosion loss was as follows: copper <1 ; solder <2 brass <1 steel <1 cast iron <2 and aluminum base alloy <2.

Example 19: The compounds have been prepared pursuant examples 1 to 18, being further refined by additives like silicone antifoaming agent in the amount of 0.1 per cent of mass, bitter flavor substance, denatoniumbenzoate, glucose penta-acetate and saccharose octa-acetate in the amount of 0.01 per cent of mass and color indicator, rhodamine B and fluorescein in the amount of 0.005 per cent of mass. Buffering capacity and corrosion weight loss remained unchanged.

Example 20: Compounds of the liquids have been prepared pursuant examples 1 to 11 and 13 to 18, with demineralized, industrial and drinking water at a ratio of 10 to 90 per cent volume of the liquid concentrate to 90 to 10 per cent volume of water. Corrosion tests were carried out as in example 1 and were no further diluted by corrosive water. The metal corrosion loss was as follows: copper <3 solder <4 brass <4 steel <4 ; cast iron <4 and aluminum base alloy <3. The compound prepared pursuant example 12 had a corrosion loss as follows: copper <1 solder <6 brass <1 steel <1 ; cast iron <6 and aluminum base alloy <2.