| 摘要 |
<p>PURPOSE:To provide a thermogenic compsn. which is excellent in latent heat of heat generation and can control temperature by itself, by blending insoluble anhydrous gypsum, an inorg. fulfate or sufite salt and water together. CONSTITUTION:Insoluble anhydrous gypsum, an inorg. sulfate or sulfite salt and water are blended together. Pref. the sulfate or sulfite is used in an amount of 0.1-5wt% based on the amount of insoluble anhydrous gypsum. When the amount is outside the above range, hydration rate becomes slow. Thus, such an amount is not preferred from the viewpoint of the utilization of exothermic energy. Preferred amount of water is in the range of 10-30wt% from the viewpoints of calorific velue and moldability. During the course of the conversion of insoluble anhydrous gypsum into gypsum dihydrate, reaction rate varies depending on temeperature conditions. Reaction proceeds rapidly at a low temp. But, at 42 deg.C or higher, the reaction rate is slow and hardly takes place. The invention is based on the discovery that while insoluble anhydrous gypsum controls temperature by itself by this peculiar reaction, is continued to proceed and the temperature is kept at 40 deg.C over a long period of time.</p> |
