GB1156703A - Gelling of Nitric Acid - Google Patents

Abstract

1,156,703. Gelled nitric acid; explosive compositions. E. I. DU PONT DE NEMOURS & CO. 8 Sept., 1966 [9 Sept., 1965; 23 Oct., 1965; 30 Aug., 1966], No. 40185/66. Headings C1A and ClD. [Also in Division C3] Aqueous nitric acid is gelled by copolymerizing in situ in the nitric acid a mixture of unsaturated monomers comprising (a) up to 20%, based on the weight of the nitric acid, of a monomer of the formula CH 2 = CRX and/or a monovinyl pyridine, and (b) up to 30%, based on the weight of (a), of a monomer having at least two terminal unsaturated methylene groups. In monomer (a) X is -CN, -COOR, -CONR 2 , or COOM, M is ammonium, alkali metal, or alkaline earth metal, and R is hydrogen or lower alkyl which may be hydroxy- or cyano-substituted. Many suitable monomers are listed, examples of (a) being acrylonitrile, acrylamide, acrylic acid, methacrylic acid, 4- vinyl pyridine, and 2-methyl-o-vinyl pyridine; and of (b) N,N<SP>1</SP> - methylene - bis - acrylamide, N,N<SP>1</SP>,N<SP>11</SP> - triacrylyl - hexahydro - s - triazine, tetramethylene glycol dimethacrylate, trimethylene propane trimethacrylate, ethylene glycol dimethacrylate, divinyl benzene, allyl acrylate, N-allyl methacrylamide, diallyl ether, diallyl adipate, diallyl maleate, diallyl ether of pentaerythritol, diallylamine, N,N<SP>1</SP>-diallyl adipamide, N-allyl acrylamide, and vinyl methacrylate. The copolymer, may be formed by free radical catalysis, using as promoters ammonium or alkali metal persulphates, perborates, or pervanadates, to which may be added hydrogen peroxide, hydrazine, hydroxylamine, or carbohydrazide, and also copper, silver, ferrous, or cobaltous ions; other catalysts referred to are hydrogen peroxide with ferrous ions, cobaltic ions with or without hydrazine and persulphate ions, and organic azo compounds and peroxides, several of which are specified. Detonating explosive compositions containing the gelled nitric acid may also include the following ingredients:-nitrobenzene, nitrotoluenes, liquid and solid hydrocarbons, cellulose and starch products, sugar, silicon, ferrosilicon, sulphur, and aluminium as non-explosive fuels; RDX, nitrocellulose, smokeless powder, and TNT as explosive sensitizers; and ammonium, sodium, and potassium nitrates, ammonium and potassium sulphates and acetates, and potassium mono-hydrogen phosphate as oxidizing salts. In making the gel, nitric acid of strength 5- 99% by weight may be sparged with nitrogen to remove oxygen and oxides of nitrogen, and then mixed with the other components, the mixture being cooled if necessary; gels of varying viscosity may be produced, ranging from flowing pourable masses to rigid bodies. Apart from its use in explosives, the gel may be used for etching and other metallurgical uses, in chemical synthesis, including the manufacture of fertilizers, and for acidifying in mineralogical processes.