Sensitizers, priming compositions

Both 2,4-dinitrosoresorcinol (23) and 2,4-dinitroresorcinol (24) are important in the explosives industry. The lead salt of 2,4-dinitrosoresorcinol has a low ignition temperature and finds use in priming compositions and in electrical igniters. The lead salt of 2,4-dinitroresorcinol is a weak initiator but is found to exhibit high sensitivity to friction and stab action without being highly sensitive to impact, and as such, this compound has found use in primers. 

Priming Composition. A physical mixture of materials that is very sensitive to impact or percussion and, when so exploded, undergoes very rapid autocombustion. The products of such an explosion are hot gases and incandescent solid particles. Priming compositions are used for the ignition of primary explosives, BkPdr, igniter charges and propellants in small arms ammunition (Ref 40a, p 112) (See also in Section 3, Part D and Section 4,... 

Glass in Priming Compositions. It is known that sensitivity of expl mi its to friction (percussion) is greatly increased when a small amt of ground glass [or of other abrasive material, such as sand or carborundum (See Vol 2, p C65-L)] is mixed with (he expl... 

Abrasive. Any grinding or polishing material, such as emery, ground glass, carborundum, infusorial earth, pumice etc. Some of these materials are used in priming compositions in order to increase the sensitivity of other components (such as MF, KCIO, etc) to friction or impact. Crystalline SbaS3 used in priming compns functions not only as a fuel but also as an abrasive(See under Primers)... 

Complex Explosives. These are formed by a combination of two or more compds or ions. Several cobalt chromium complexes were studied by Tomlinson (Ref) to determine their promise as initiators or ingredients of priming compositions. As a class, chromic salts appeared to be more sensitive to initiation more brisanr, and to possess greater initiating ability than cobaltic compds. The latter type of complexes, however,... 

The ideal priming composition would consist of a cheap, readily available, relatively safe to handle, simple chemical compound of uniform granulation which when subjected to impact would undergo rapid, highly exothermic decomposition. The only compound to even approach these specifications is lead dinitroresorcinate however, it is far too sensitive. In practice, no single chemical compound meets all the requirements of an ideal primer. 

CHAPTER 17 THE PREPARATION OF NITRO TETRAZOLES LNTA forms heavy, granular, yellowish white crystals, which are not very soluble in water—the crystals are more readily soluble in hot water. LNTA detonates when heated to 220 Celsius, and is slightly more percussion sensitive then mercury fulminate as a result, its use in priming compositions has been questioned, but it can be safely desensitized by mixing with dextrose, flour, or gum Arabic immediately after preparation. The desensitized product can be successfully used in priming compositions for use in bullet primers and the like. ... 

Another important use of primary explosives lies in their application as sensitizers in priming compositions. The purpose of such mixtures is to provide reliable ignition and the role of the primary explosives in such mixtures is to make them sensitive enough to be easily ignited. The detonation of such a mixture is undesirable and must be prevented by careful selection of the ingredients and then-quantities for a particular application. 

Priming compositions or priming mixtures are sensitive explosive mixtures that are designed to produce a flame in a particular application. They are most often mixtures containing a primary explosive as one of the components in such a form and amount that ensures the inability to initiate detonation of the mixture. The role of the primary explosive is to sensitize the mixture to external stimuli, not to make it detonatable. Priming mixtures are used in percussion caps for ignition of gun powder, on electric fuseheads, delay elements, etc. 

Duguet, J. Priming composition which is sensitive to percussion and a method for preparing it. US Patent 4,566,921, 1986... 

Introduction. This chapter contains discussions of military primary explosives. The chemical, physical, thermochemical, sensitivity, performance, and stability characteristics of each explosive are covered. The method of manufacture is also given. If knov m, the chemical structure of each compound is shov m. This chapter also contains a discussion of priming compositions. 

Sallott, G. P. et al., Proc. Int. Pyrotech. Semin., 1984, 589-602 Compositions prepared from mercury(II) nitrate and ferrocene or its derivatives show promise as explosive priming mixtures, but such mixtures are fairly sensitive to electrostatic initiation and should be handled in the wet state. 

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