GB757129A - Improvements in or relating to propellents and method of making same - Google Patents

Abstract

757,129. Propellants. OLIN MATHIESON CHEMICAL CORPORATION. April 8, 1954 [June 9, 1953], No. 10346/54. Class 9(2) A propellant for cartridges for rapid fire guns is prepared by forming nitrocellulose powder base into grains having a surface area 75-84 sq. cms. per gram and a web 0.015-0.025 in., and treating the grains with a non-migratory deterrent, having a negative, heat of explosion constant greater than -200 calories per gram, only in the region thereof which extends from each surface not more than 1/6th of the web of the grain. Deterrents, which may be present in amount 3-12 per cent, may be dibutyldiamyi-, or diphenylphthalate, triphenyl- or tricresyl phosphate, butyl stearate, diethyl-, methyl ethyl-, or dimethyl-diphenyl urea, or glycerol sebacate. The grains may be impregnated with 10- 20 per cent liquid explosive nitric ester of a polyhydric alcohol, e.g. 10 per cent nitroglycerine, as energizing modifier before deterrent treatment. In an example, nitrocellulose (13.2 per cent N 2 ) is dehydrated with ethyl alcohol and partially colloided by agitation with diethyl ether and diphenylamine. The nitrocellulose is blocked and forced through an extrusion die and cut into cylindrical grains of length equal to thickness. After drying, the grains are suspended in water, and an emulsion of nitroglycerine. ethyl acetate, toluene, and gum arabic in water is added, and the temperature raised to 70‹C. The ethyl acetate and toluene are removed by passing in air with continued agitation. An emulsion of dibutyl phthalate and gum arabic in water is added to the agitated slurry and the grains separated. The grains are tumbled in a sweetie barrel with potassium nitrate, diphenyl phthalate, and dinitrotoluene, and then with graphite. The resulting grains have surface area 77 sq. cms./grm., web 0.016 in., and contain 6.5 per cent deterrent in the region 0.0025 in. from each surface.