Patent GB-587452-A (GB)
Title: Improvements in or relating to processes of manufacturing tetryl
Filed: 1944-02-25
Abstract: Tetryl is purified by mixing with agitation a 25 per cent. to 50 per cent. by weight solution in an inert water mixible organic solvent therefore at a temperature between 40 DEG C and the boiling point of the solvent and not higher than 90 DEG C, with an amount of water equal to 3 to 5 times the weight of the tetryl and having a temperature of 50 DEG  C.-90 DEG  C. and continuing agitation until the precipitated tetryl in the liquid phase solidifies.  Additional water may be added after solidification.  In an example water is added rapidly with vigorous agitation to an acetone solution of tetryl.  The solidified product is separated, washed with hot water and dried.  The mother liquor is treated with cold water and the precipitated material added to the crude tetryl, the diluted mother liquor being then fractionally distilled to recover the solvent.  The process may be carried out continuously by passing tetryl solution and water into the bottom of a vessel provided with an agitator, the overflow suspension being passed to filter beds, preferably after adding more water.  Other solvents specified which may be used alone or in admixture are methyl ethyl ketone, methyl acetate, dioxane, ethylene glycol or diethylene glycol-mono alkyl (such as methyl, ethyl or butyl) ethers.  The solvent may also contain a little water or one or more organic liquids such as methyl, ethyl and isopropyl alcohols, benzene, toluene, chlorobenzene, ethylene chloride, trichloroethylene, methyl isobutyl ketone or ethyl acetate.  A constant boiling solvent mixture may be used.ALSO:Tetryl is purified by mixing with agitation a 25-50 per cent by weight solution in an inert water-miscible, organic solvent therefor, at a temperature between 40 DEG  C. and the boiling point of the solvent and not higher than 90 DEG  C., with an amount of water equal to 3-5 times the weight of the tetryl and having a temperature of 50-90 DEG  C., and continuing agitation until the precipitated tetryl in the liquid phase solidifies.  Additional water may be added after solidification.  The process may be used to treat crude tetryl obtained by the nitration with mixed acid of dimethylaniline or dinitromethylaniline.  The tetryl treated preferably contains a trace of nitric acid.  In an example, water is added rapidly with vigorous agitation to an acetone solution of tetryl.  The solidified product is separated, washed with hot water and dried.  The mother liquor is treated with cold water, and the precipitated material added to the crude tetryl, the diluted mother liquor being then fractionally distilled to recover the solvent.  The process may be operated in a continuous manner by passing tetryl solution and water into the bottom of a vessel provided with an agitator.  The overflow suspension is passed to filter beds, preferably after addition of more water.  Other solvents specified which may be used alone or in admixture are methyl ethyl ketone, methyl acetate, dioxane, ethylene glycol- or diethylene glycol-mono-alkyl (such as methyl, ethyl or butyl) ethers.  The solvent may also contain a little water or one or more organic liquids such as methyl, ethyl and isopropyl alcohols, benzene, toluene, chlorobenzene, ethylene chloride, trichloroethylene methyl isobutyl ketone or ethyl acetate.  A constant boiling solvent mixture may be used.