PL80202B1 - - Google Patents

Description

Proprietor of the patent: Dynamit Nobel AG, Troisdorf (Federal Republic of Germany) Fuseless molding of the propellant charge The invention concerns the moldless moldings of propelling landings made of explosives that burn at a moderate rate or that decompose when deflagrating, not susceptible to detonation, such as detonation. vinyl nitrate, nitroguanidine, pentrite and the like - or a mixture of these materials. These moldings are particularly applicable to industrial devices such as stud shotguns, impact devices, operating elements, quick-action switches or the like. However, when using such moldings there are great advantages, as the usual cartridge cases fall off. However, their serious drawback is also revealed, consisting in the fact that the unprotected surface is sensitive and the moldings due to the easy flammability of the explosives used to make them ignite rapidly or may be ignited inadvertently. may be stored and used only with the prescribed precautions. Moreover, the unprotected surface of the moldings, due to the absorptive properties of the substances used and the usually porous structure, absorbs vapors of water or other liquids, as well as contaminants such as grease, oil, dirt and the like. In addition to the special handling for safety reasons, it is therefore also necessary to take care of the age of manipulation under the usually primitive conditions of handling the compacts in practice. The object of the invention is to remedy the above-mentioned drawbacks. According to the invention, this is achieved by the fact that the moldings are provided with a tightly adhering, preferably a thin, protective film to protect against unintentional ignition or burning, and against contamination and moisture uptake. Such a protective layer is produced by denitrating the surface of the molding, that is, by the decomposition of nitro or nitrate groups on the surface. The cleavage of the nitro or nitrate groups on the surface of the starting material is simply achieved by immersing the pressurized in a bath of suitable chemicals such as sulphites or hydrosulphites and the like, and then removing the cleavage products by washing. In addition, or in place of the layer thus formed, The coils can be applied to the compacted protective film of reactive resins, for example polyurethanes, polyglycides and the like, or soluble resins, such as polyvinyl acetate and mixed polymers, polyacrylates, and also suspensions based on polybutadiene, polyvinyl acetate and polyacrylate. In addition, products such as methyl cellulose, cellulose glycolates or the like are used as materials for the production of protective films. 80 20280 202 3 The protective film is applied, depending on the type of starting material used, by dipping, coating or rolling out of solution. While polyurethane varnishes are suitable for dipping and coating, they can be used both as pre-polymers with additional cross-linking and as finished varnishes, as well as multifunctional aromatic glycide ethers, mixed polyethylene-polyvinylacetate polymers, polyesters. acrylic, polyvinyl acetate suspensions, mixed polybutadiene polymers and mixed polyacrylic polymers, cellulose glycolates are preferably used for precipitation. If there is or is provided a flame mass, the protective film may cover it or possibly also attach. Since penetration into the porous structure of the compact is avoided in the procedure according to the invention, the protective film may therefore be very thin, but nevertheless the risk of handling the compacts is reduced to a moderate size. In addition, a deeper penetration of contaminants is largely prevented and the resistance to mechanical stress is improved and the abrasion resistance is reduced - without the formation of significant residues upon combustion. Example. From moist, fibrous nitrocellulose with a nitrogen content of 12.6%, to which 3% of centralite and 0.5 of diphenylamine were applied, tablets with a diameter of 6 mm and a thickness of 5 mm were made in a matrix by means of a hydraulic press. On one of the surfaces they have a sloping indentation 2 mm deep and with an upper diameter of 4 mm. The tablets have a smooth surface and are so resistant to mechanical stress that they do not break with normal handling. The porous structure is also recognizable by the fact that the tablet sucks up drops of water. The tablets are dried before further processing. Then 5 mg of a moist ignition mass is rubbed into the cavity and the plate is dried until it is dehydrated. The tablets are then passed through a bath consisting of a mixture of 20.4 parts glycol polyester with a molecular weight of 1200, 6 parts toluene diisocyanate, 3 parts dimethyl glycol phthalate and 70 parts methylene chloride. The solvent evaporates very quickly. As a result of the subsequent heating, the coating hardens and forms a well-adhering thin film that protects the powder from all sides. PL PL

Claims (1)

1. Claimed Claimless molding of a propellant charge from explosives such as nitrocellulose, polyvinyl azoitane, iidtroguanidine, pyrite, etc. or from mixtures thereof, in particular for devices for industrial use, such as shock-breakers, collet breakers, impact devices operators, quick-action switches or the like, characterized in that it is provided with a strongly adhering thin protective film, produced by subjecting the decomposition of nitro or nitrate groups in the surface of the molded part and / or constituting a coating of reactive resins, therefore, soluble, methyl cellulose, carboxymethyl cellulose or the like. LDA - Plant No. 2 - TYPO, dom. 586/76 - 100 copies. Price PLN 10 PL PL