| abstract |
1284136 Exothermic compositions CIBA GEIGY AG 4 Nov 1969 [4 Nov1968] 54086/69 Heading C5G An exothermic composition which liberates heat on adding water consists of an alkali metal oxide or an alkaline earth metal oxide and a solid acid or an acid salt of a strong acid, or mixtures, thereof. Oxides of Ca, Ba, Sr, Na, K, or Li are preferred, and the acid may be phosphoric, sulphamic, tartaric, oxalic, or citric. Preferred salts are sodium hydrogen sulphate and potassium hydrogen sulphate. The acids may be hydrated, and a preferred acid mixture consists of a major portion of hydrated oxalic or citric acid and the remainder sulphamic acid. There should be more than enough oxide present to neutralize the acid reactant, but not more than enough to react with all the acid and all the water produced during the reaction of the acid and the oxide. |