PURPOSE: To form a cooling agent which is easy to store for a long time, has a great cooling capacity and a long working life, and is handy for carrying, by using specified ester and monohydric alcohol in combination with water as catalyst.
CONSTITUTION: This cooling agent is prepared by mixing on use one or more substances selected from the group consisting of esters of, e.g., formic acid, acetic acid, propionic acid, and lactic acid (wherein the number of carbon atoms is 10 or less) with one or more substances selected from the group consisting of monohydric alcohols, e.g., methanol, ethanol, propanol, and butanol (wherein the number of carbon atoms is 10 or less). This mixture undergoes a reaction shown by the formula (wherein R1 and R3 are each alkyl; R2 is alkyl, phenyl, benzyl, etc.) in the presence of water. The heat of reaction (endothermic) is utilized for cooling. In this endothermic reaction, the reaction rate can be controlled by the amount of water added which serves as catalyst, and the working life can thereby be adjusted.
ISHIMURA KAZUHIKO
HASEGAWA KAZUKO
