Nature of the description: white hygroscopic crystalline powder or colorless shiny diamond crystal, flammable. The melting point 263 ℃, which exceeds the melting point of sublimation and decomposition, but does not melt. Heated to 300 ℃, release hydrogen cyanide, the temperature rises again, then broken down into methane, hydrogen and nitrogen. The relative density of 1.331 (20 / 4 ℃), flash point 250 ℃. Almost no smell, sweet and bitter. Soluble in water and chloroform, insoluble in carbon tetrachloride, acetone, benzene and ether, insoluble in petroleum ether. In the weak acid solution is decomposed into ammonia and formaldehyde. Contact with the flame, immediately flame burn and produce smoke. Are volatile.
Production methods: from formaldehyde and ammonia condensation obtained. Formaldehyde solution will be placed in the reactor, Tung ammonia, carried out in an alkaline solution condensation reaction, the reaction temperature maintained at 50-70 ℃, liquid cooled into liquid film vacuum evaporator at 60-80 ℃, under evaporation, so that its concentration from 24% to 38% -42%, and then filtering the reaction solution by vacuum evaporation crystallization, leaching was finished drying the methenamine.