JPH0561317B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a novel coolant. More specifically, it is a coolant containing an inorganic salt and/or organic salt that has an endothermic reaction with water, urea, water, and a special thickening gelling agent. This invention relates to a refrigerant with improved durability. [Prior art] Generally, when ammonium nitrate is dissolved in water,
Although it exhibits a cooling effect by lowering the temperature to around -5°C for several minutes, it has the drawback of extremely short low-temperature sustainability. This is because ammonium nitrate has a very high solubility in water, and all of it dissolves instantly. In addition, since the solubility of a mixture of ammonium nitrate and a compound having water of crystallization in the molecule is generally high in water, the solubility of these compounds in water is 40 to 60 parts per 100 parts of the salt.
It is used with a small amount of water, such as Although a low temperature drop can be obtained in this case as well, since the amount of water is small, its solubility is also low, and the entire endothermic ability of ammonium nitrate cannot be brought out, so it is difficult to obtain sufficient low temperature maintenance ability. An example that has already been published as a patent is a method in which an inorganic salt such as ammonium nitrate and a salt having water of crystallization in the molecule are used in combination to mix both solids in the absence of water. This coolant is obtained by utilizing the endothermic reaction of ammonium nitrate with crystal water. However, in these methods, a rapid endothermic reaction occurs with the water of crystallization and the temperature is lowered, but the drawback is that low-temperature sustainability is low, and various improvements have been attempted. In addition, the patent publication and the patent publication describe a method of using other salts in combination to provide low-temperature sustainability, and furthermore, although there is no cooling ability, carboxymethyl cellulose, gelatin, casein, which is known as a moisture absorbing agent for improving solutions, etc. Methods are known in which silicates, silica gel, asbestos, kaolin, bentonite, calcium carbonate, magnesium carbonate, etc. are added to inorganic salts, organic salts, urea, and water. [Problems to be Solved by the Invention] However, such conventional methods have not sufficiently achieved the objective of increasing cooling capacity and low-temperature sustainability, and there is still room for improvement. The present invention aims to solve the above problems. [Means for Solving the Problems] The present inventors have discovered that by dissolving inorganic salts and/or organic salts and urea in special water, low-temperature cooling can be easily obtained and the cooling ability can be maintained for a long time. As a result of various studies on coolants, we found that inorganic and/or organic salts that have an endothermic reaction with water, urea, water and special thickening gelling agents, preferably nonionic, anionic, or amphoteric surfactants, It has been discovered that a coolant formed by thickening and gelling a copolymer obtained by addition-polymerizing propylene oxide and ethylene oxide to a polyhydric alcohol, or a polyoxyethylene-hydrogenated lanolin obtained by adding ethylene oxide to lanolin, achieves the above object, The present invention has now been completed. The reason why the cooling ability of the coolant of the present invention lasts for a long time is that in the presence of water, the thickening gelling agent improves the viscosity of the water and dissolves in water to gel, absorbing heat. This is thought to be because the salts that cause the reaction do not dissolve rapidly, but the dissolution proceeds gradually, resulting in sustained cooling. Examples of inorganic salts and organic salts having cooling ability effective in the present invention include ammonium nitrate, ammonium chloride, potassium chloride, potassium dichromate, potassium permanganate, sodium carbonate decahydrate, sodium thiosulfate pentahydrate, and sodium sulfate. Examples include decahydrate, calcium chloride hexahydrate, calcium nitrate tetrahydrate, sodium sulfide nonahydrate, oxalic acid dihydrate, potassium hydrogen oxalate, and potassium oxalate. Among these, ammonium nitrate is often used because of its large cooling capacity. These inorganic salts and/or organic salts may be used alone or in an appropriate combination of two or more together with urea. In the present invention, urea is important in obtaining maximum efficacy before cooling due to its ability to control the solubility of other salts. The use of urea in the present invention is from 100 to 300 parts, preferably 150 parts per 300 parts of inorganic and/or organic salts.
A range of ~250 parts (weight ratio) is good. The special thickening and gelling agents that improve low-temperature sustainability in the present invention include polymer surfactants with various structures and properties, polyols that are copolymer compounds, and hydrogenated lanolins. More specifically, the polymeric surfactant of the present invention is a non-polyoxyethylene alkyl ether made by addition polymerizing 3 to 50 moles of ethylene oxide to a higher saturated alcohol having an alkyl composition of 12 to 18 carbon atoms and having a hydroxyl group in the molecule. Examples of ionic surfactants include those with 3 to 5 moles of ethylene oxide added to lauryl alcohol with an alkyl composition of 12 carbon atoms, and those with 20 moles of ethylene oxide added to stearyl alcohol with an alkyl composition of 18 carbon atoms are particularly excellent. Demonstrate performance. Furthermore, lauric acid, myristic acid, which is a saturated higher fatty acid with an alkyl composition of 12 to 18 carbon atoms, and which has a different structure from the above-mentioned ether type nonionic surfactant,
Effective are alkyl diethanolamide type nonionic surfactants synthesized from palmitic acid, stearic acid, and unsaturated higher fatty acids with an alkyl composition of 18 to 22 carbon atoms, oleic acid, linoleic acid, linoleic acid, and erucic acid. In addition, several types of anionic surfactants whose main components are polymeric higher alcohols and whose structures and properties are completely different from the above-mentioned nonionic surfactants are effective as thickening and gelling agents. be. As an example, sulfation of the hydroxyl group of lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, which are saturated higher alcohols with an alkyl composition of 12 to 18 carbon atoms, and oleyl alcohol, which is an unsaturated higher alcohol, and ethylene oxide to each higher alcohol. 3 to 10
An anionic surfactant prepared by sulfating polyoxyethylene alkyl ether with molar addition and neutralizing each sulfate with sodium also exhibits excellent effects. Further, as above, an anionic surfactant prepared by neutralizing a sulfated product of a higher alcohol or a sulfated product of polyoxyethylene alkyl ether with triethanolamine, and a sulfated product of a higher alcohol,
Alternatively, an anionic surfactant, which is an ammonium salt obtained by neutralizing polyoxyethylene alkyl ether sulfate with ammonium, is also a good thickening and gelling agent. In addition to nonionic and anionic surfactants, fatty acid amidopropyldimethylaminobetaine-type amphoteric surfactants whose main components are saturated fatty acids with an alkyl composition of 12 to 18 carbon atoms, and oleylamidepropyldimethylaminobetaine, an unsaturated fatty acid. type amphoteric surfactant, betaine type amphoteric surfactant of saturated fatty acids with alkyl composition of 12 to 18 carbon atoms such as lauric acid, myristic acid, palmitic acid, and stearic acid; oleyl dicarboxymethyl betaine type amphoteric surfactant of unsaturated fatty acid The agent has excellent properties. Further, by mixing this betaine type amphoteric surfactant and each of the above-mentioned nonionic or anionic surfactants in an appropriate ratio, even more excellent properties can be exhibited. Furthermore, monomeric polyhydric alcohols having structures and properties different from those of the above-mentioned nonionic, anionic, and amphoteric surfactants, such as propylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, propylene oxide, A mixed gelling agent consisting of a polyol of a copolymer obtained by addition polymerization of ethylene oxide, and an appropriate mixture of the substance and an alkylolamide nonionic surfactant exhibits better properties. The present inventor has also confirmed that polyoxyethylene-hydrogenated lanolin, which is obtained by adding ethylene oxide to lanolin, also has excellent thickening and gelling properties. The various thickening and gelling agents used in the present invention are preferably used in an amount of 5 to 20 parts based on water. Although various thickening and gelling agents alone can be sufficiently effective, excellent effects can be obtained by mixing different thickening and gelling agents in appropriate proportions. In addition, by mixing a polyol with various surfactants, or by mixing a poorly water-soluble gelling agent with various surfactants, a thickening gelling agent that is soluble in water and has excellent gelling properties can be obtained. You can get it. In the present invention, anhydrous or hydrated inorganic salts and/or organic salts having endothermic energy can also be used. Examples of anhydrous inorganic salts and organic salts used in the present invention include ammonium nitrate, ammonium chloride, potassium chloride, potassium oxalate, and potassium hydrogen oxalate. Examples of hydrated substances containing water of crystallization in the molecule include sodium sulfate decahydrate. salt, sodium carbonate 10
Examples include hydrate, sodium thiosulfate pentahydrate, calcium nitrate tetrahydrate, sodium sulfide nonahydrate, oxalic acid dihydrate, etc., and two or three of these may be used in combination. The present invention will be specifically explained below with reference to Examples and Comparative Examples. Examples 1 to 16 In order to carry out the present invention, various thickening and gelling agents shown in Table 1 are dissolved in water, and a coolant mixture of each composition is added and dissolved therein to determine the low temperature persistence of the coolant. Table 1 shows the changes over time. In addition, for comparison with the present invention, in Table 2, coolant components of various compositions were mixed, and changes over time in low-temperature sustainability of the coolant were shown. From the Examples and Comparative Examples, it is clear that the coolant of the present invention has excellent cooling ability and low-temperature sustainability.

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[Table] [Effects of the Invention] According to the present invention, low-temperature cooling can be easily carried out, and the cooling ability can be maintained for a long time, which is an epoch-making effect.

Claims (1)

[Claims] 1. An inorganic salt and/or organic salt having an endothermic reaction with water, urea, water, and an alkyl composition having 12 carbon atoms.
A coolant containing a nonionic surfactant consisting of polyoxyethylene alkyl ether, which is obtained by adding ethylene oxide to ~18 saturated alcohol. 2 Inorganic salts and/or organic salts that have an endothermic reaction with water, urea, water and a saturated or unsaturated alkyl group having 12 to 18 carbon atoms, with a molecular formula A cooling agent containing an alkydiethanolamide nonionic surfactant represented by: 3 Inorganic and/or organic salts that have an endothermic reaction to water, urea, water and alkyl composition with 12 carbon atoms
A coolant comprising an anionic surfactant of the triethanolamine salt, ammonium salt or sodium salt of ~18 saturated or unsaturated alkyl sulfuric acid or polyoxyethylene alkyl ether sulfuric acid. 4 An inorganic salt and/or organic salt that has an endothermic reaction with water, urea, water and a saturated or unsaturated alkyl group having 12 to 18 carbon atoms, with a molecular formula of Alkylamidopropyl dimethyl betaine series or A cooling agent containing an alkyl betaine amphoteric surfactant represented by: 5 Inorganic salts and/or organic salts that have an endothermic reaction with water, urea, water, saturated or unsaturated alkylamide propyl dimethyl betaine-based or alkyldicarboxymethyl betaine-based amphoteric surfactants having 12 to 18 carbon atoms, and anions. or a coolant comprising a mixture of nonionic surfactants. 6 Inorganic salts and/or organic salts that have an endothermic reaction with water, polyols of copolymers made by addition polymerization of urea, water, propylene glycol, trimethylolpropane, glycerin, pentaerythritol, sorbitol, propylene oxide, ethylene oxide, or such compounds. and an alkylolamide type nonionic surfactant. 7. A coolant containing polyoxyethylene-hydrogenated lanolin, which is obtained by adding ethylene oxide to inorganic and/or organic salts having an endothermic reaction with water, urea, water, and lanolin.