FR2686970A1 - FUEL CARTRIDGE SOCKET. - Google Patents

Abstract

The invention relates to cartridge cases the walls of which are combustible or decomposable. The walls are formed by one or more windings of textile fibers which are bound by a particular binding agent. Binding agents have the characteristics of explosive agents and are made up either of a mixture of polymers and explosives having a decomposition temperature above 180 ° C, or of nitro aromatic polymers which have two or more nitro groups per aromatic nucleus and which also have decomposition temperatures above 180 ° C. Mixtures of these two groups of binding agents can also be used. Cartridge cases which have such walls are formally stable, have high mechanical strength, are very temperature stable up to 24 ° C and burn without leaving virtually any residue.

Description

D

FUEL CARTRIDGE SOCKET

  The object of the present invention is a cartridge case for ammunition, combustible or decomposable, the wall of which consists of one or more windings of textile threads which are linked with

a binding agent.

  Sockets of combustible or decomposable cartridges whose walls comprise several windings of textile threads, are known for example from DE-A-24 24 900 The textile threads are nitrated and reinforced by synthetic threads The individual windings are linked one to the other by a binding agent and reinforced Nitrocellulose is preferably used as binding agent, but it is also possible

use other plastics.

  These known combustible or decomposable sockets however have the following drawbacks: it is known that when using non-metallic cartridges, the energy which is developed during firing cannot be eliminated satisfactorily, so that the magazine for cartridges heats up faster than when using metal sockets In addition, it also happens that combustible sockets transmit their combustion heat to the cartridge chamber. As a result, after several shots, the cartridge magazine is so hot that there is early ignition of the ammunition in the cartridge chamber. Such early ignition takes place in particular for ammunition whose propellant charge

  has insufficient temperature stability.

  The propellant charges described in DE-A-24 24 900 exhibit such an insufficiency of temperature stability, so that the nitrated textile fibers behave practically like nitrocellulose and decompose by explosion at temperatures above 1500 C at following an autocatalysis Such a temperature is reached very quickly after firing

with non-metallic sockets.

  There was therefore the problem of obtaining cartridges of combustible cartridges which are thermally stable at a temperature higher than 1500 C, intervening in the cartridge store and which have a high mechanical resistance The high mechanical resistance is necessary to protect the explosive charge from '' other external mechanical influences during storage and transport of ammunition and to take over the sealing function in the cartridge chamber at the start

of shooting.

  This problem was solved by the discovery of cartridge cases for combustible or decomposable ammunition whose walls are made of one or more windings of textile fibers which are linked by a binding agent and which is characterized by the fact that it contains polymers which, during their combustion, do not form aggressive gases, in admixture with explosives whose decomposition temperature is above 1800 C and / or aromatic nitro polymers having decomposition temperatures above 1800 C and which have on average two or more of two nitro groups per aromatic nucleus. The binding agents in accordance with the invention can in themselves have propellant properties in this case, they can be used without the addition of explosive substances stable at high temperature. The binding agents which themselves do not have propellant properties, can be used in mixture with explosives stable at high temperature. The explosive part in these mixtures can be between 30 and 70% and preferably between 40 and 60%.

in weight.

  As binding agents for this field of application, more particularly suitable are thermoplastic polymers, which burn without leaving a residue and which do not form aggressive gases during their combustion. Particularly suitable bodies are those prepared by reaction of polyvinyl alcohol with aldehydes having 1 to 6 carbon atoms which can also be classified in the family of polyvinylacetals Preferably used

polyvinyl butyral.

  Appropriate binding agents, in accordance with the invention, also consist of polymers which are introduced in the form of monomers and which, after mixing and in the presence of an appropriate initiator or of a crosslinking agent, are subjected to radical condensation or crosslinking Among these compounds, mention may be made of methyl- (meth) -acrylate

or acrylonitrile.

  As binding agents, polyurethanes, polyesters, epoxy resins or rubber can also be used, optionally in the form of

aqueous solutions or emulsions.

  As regards the explosive bodies, stable at high temperature, which according to the invention can be used with binding agents, mention may be made of the explosive bodies known per se, thermally stable above 180 C and giving rise to to gas formation, organic nitro derivatives, nitroamines, as well as nitric acid esters Organic nitro derivatives are for example aromatic products with one or two rings, such as the di or triamino derivatives of symmetrical trinitrobenzene, their products acylation, such as by

  example s-hexanitro-oxanilide or s-hexanitro-

  diphenylurea, as well as picric acid salts, such as ammonium or guanidine picrates This group also includes nitrated aromatic products with two rings, which are optionally linked to each other by via a carbon atom, such as, for example, the diphenyl nitro, its derivative 3,3 '-diamino and shexanitrostilbene or nitro aromatic products with two rings which are linked via an atom of oxygen, sulfur or nitrogen Examples

  are hexanitrodiphenyloxide, hexanitrodiphenyl-

  sulfide, hexanitrodiphenylsulfone and hexanitro-

  diphenylamine Furthermore, heterocyls containing picryl residues, such as thiophene, 1,3thiazole, triazine or pyrimidine, nitro heterocycles, such as tetranitrocarbazole, tetranitroacridone or tacot, also belong to these groups. sure is

  consisting of 2,3-tetranitro: 5,6-dibenzo-1,3 a, 4,6 a-

  tetraazapentalene. The thermally stable nitric acid esters which can be used as an explosive, in accordance with the invention, such as the nitroamines, are less numerous. Mention may be made, by way of example, of hexanitrodiphenylaminoethylnitrate which, compared with hexanitrodiphenylamine, has gained in stability by substitution of the hydrogen atom of the NH group As an amino nitro derivative, octogen in its two isomeric forms o (and B, more particularly the

  last, has great value.

  Binding agents based on nitro polymeric aromatic products which have propellant properties, are essentially dichloropolynitrobenzene or dichloropolynitrodiphenyl polymerization products. Polymers are homopolymers of these products which, in the presence of copper powder, are obtained according to a reaction of 'Ullmann or reaction products of these aromatic products with nitrated hydroquinones The compounds are for example described in DE-C-27 52 166 and DE-A-30 23 462, to which it is more particularly

refers to.

  The nitro aromatic polymers can be used alone or in admixture with the above-mentioned binding agents, as conforming binding agents.

to the invention.

  In addition to the explosive substances, oxygen donors can also be present in the binding agents, either alone or as a mixture with metallic powder, in the form of a solution or dispersion. As oxygen donors, mention may be made of oxidizing agents from the group of metal peroxides, nitrates of alkali or alkaline earth metals, or peroxide disulfates The preferred oxidizing agents are zinc peroxide As the metal, mention may be made more particularly of titanium, zirconium, magnesium, cermagnesium, cersilicon,

aluminum-magnesium alloys.

  The oxidizing agents used in amounts of 0 to 50% by weight, relative to the mixture of binding agents and the metals, are present in proportions of O to 20% relative to the mixture of binding agents When used jointly oxidizing agents or metals, it is preferred to use the groups of substances present in proportions such

  that they burn up like a pyrotechnic mixture.

  The fibers which can be used in accordance with the invention are easily combustible textile fibers which are known in themselves for producing walls of cartridge cases as reinforcing fibers. For this purpose, either fibers totally synthetic or natural fibers which, at the combustion temperatures of the powder with an explosive charge, are combustible or decomposable. Among the fibers which can be decomposed, mention may be made of fibers which, at the combustion temperatures of the powder of the charge, essentially transform into gaseous product and / or finely divided particles The fibers which, during their combustion or their decomposition, increase the oxygen index of the

  filler powder, are particularly preferred.

  Fibers which are also particularly preferred are easily combustible organic fibers, such as polyester or polyamide fibers. By polyester fibers, mention may be made of fibers which result from condensation products of aromatic dicarboxylic acid, in particular terephthalic acid. or their esters with diols Examples of polyamide fibers are the different

kinds of Nylon.

  In addition to fibers wholly or semi

  synthetic, other totally or semi-synthetic fibers can also be used, such as for example polyolefin fibers (such as polyethylene or polypropylene fibers), polyacrylic fibers such as for example poly (meth) acrylic fibers or polymer fibers which

  result from the addition of polyglycols on the diiso-

  cyanates such as polyurethane fibers Examples of other semi-synthetic fibers are those derived from natural polymers, such as for example based on cellulose Mention may be made here of cellulose acetate fibers having an acetyl group content included between 74 and 92% and in which the acetyl groups can also be, by total or partial saponification, hydrolysed or else

  cellulose fibers which according to the copper process

  ammonia, are prepared from regenerated cellulose or from the viscose process. Mention may also be made of fibers called synthetic silk. It is also possible to use fibers of inorganic products which can be decomposed at the combustion temperatures of the explosive charge / binder mixture and which form combustion products turning to dust. Mention may be made in this connection of metallic fibers or

glass fibers.

  Among the fibers which can also be used, mention may be made of graphite fibers or carbon fibers. As an example of natural fibers, we

  may cite casein, cotton, hemp or jute.

  The cartridge case sockets are produced in accordance with the invention in a manner known per se: the fibers are first wound on a sleeve, preferably several

  windings with a defined thread tension.

  The winding of several layers can be carried out for each of the layers in a different direction and pitch compared to the previous layers or applied subsequently, so that the threads of a layer cross the threads of the lower or upper layer It is also one or more layers of yarn may be applied so

longitudinal on the socket.

  The individual wires can have different sections; preferably they have a circular section, with a diameter of the order of 15 to 25 pum These threads can consist of a large number of finer, individual filaments, which can be

twisted before winding.

  The application of the binding agent according to the invention is preferably carried out before the winding of the wires on the sleeve. In the binding agent, are also in the form of a homogeneous solution or dispersion, in addition to the explosive products. optionally oxidizing agents and metal powder, other additives known per se for explosives, such as combustion moderators, porosity agents It is also possible to apply the binding agent during the course of the winding, for example by sprinkling the fibers or even on the finished winding, for example by immersion

  of the bundle of fibers wound in the binding agent.

  After obtaining the winding coated with the binding agent and the additives, the binding agent is left to harden, for example at high temperature If necessary,

it is free from solvents.

  After hardening, the winding obtained is transformed in a known manner into the sleeve

  cartridge with the desired geometry.

  Optionally, it is still subjected to a surface coating to obtain better sliding properties

in the weapon.

  The cartridge cartridges claimed preferably have an external diameter greater than 20 mm They are stable against thermal decomposition at temperatures above 1500 C and up to 2500 C They also have shape stability and mechanical resistance sufficient to protect them from external influences during storage and handling and for the sealing function in the cartridge chamber during

start of shooting.

  In addition, the casings burn practically without leaving a residue when fired or decompose by formation of decomposition products in the form of particles, easily removable from the cartridge store, so that it is possible to

  proceed to a series of rapid shots.

EXAMPLE 1

  On a rotating glass pipe having a diameter of 15 mm, a viscose fiber winding is carried out at an angle ranging from the right angle relative to the longitudinal axis to 10, over a

  layer, up to a width of about 10 cm.

  This product was then painted with a mixture of an acrylic resin emulsion in water, containing 50% solid matter and octogen (1: 1, compared to the solid content) and the whole a was slightly dried with hot air On the still flexible layer, a new layer of viscose fibers was applied, as indicated above, in an opposite direction. The second layer was again coated as indicated above. proceeded in this way until six layers of fibers were obtained. The finished winding was then hardened in an oven at 1500 ° C. for 30 minutes. After these procedures, after separation from the glass pipe, a solid pipe with a wall thickness of 0.8 mm which included approximately 20% by weight of fibers and the remainder consisting of octogen and the binder

in a weight ratio of 1: 1.

  The sample of the pipe was cut into a small piece and introduced into a glass pipe which was heated in a Wood-scher alloy with 20 K / min At 244 a C, a significant development of smoke was observed by decomposition of the components The ignition of the coil sample with a gas flame spontaneously gave rise to combustion with a

total destruction.

EXAMPLE 2

  A pipe was prepared as described in Example 1, in which a gel comprising a mixture comprising g of polyvinyl-n-butyral and 5 g of polynitropoly phenylene in 40 g of was applied to the winding layers a mixture of solvent agents constituting ethyl acetate at 78 V /%, butyl acetate 15 V /% and ethanol 15 V /% After preparation of six layers, the thickness of the wall of the pipe is dried at 1000 C for 1 hour and was 0.4 mm The proportion of fibers was 11.2% The weight of transformation into smoke according to the process described above was 2350 C Destruction by combustion under pressure normal was violent and led to

  virtually residue-free destruction.

EXAMPLE 3

  A process as in Examples 1 and 2 The product applied, however, consisted of a mixture of cellulose acetate in an organic solvent having a solid content of 34% and octogen, in proportions by weight of 1: 1 with respect to the fluid After the application of six winding layers, it was heated for 1 hour at 1000 ° C. The pipe thus obtained after extraction from the glass pipe, had a wall thickness of 0.5 mm The fiber content was 16.1% by weight The weight of transformation into smoke was around 2530 C. The destruction by combustion at ambient pressure was violent by the formation of soot The formation of soot can be

  reduced by addition of an oxidizing agent.

Claims (3)

  1 Combustible or decomposable cartridge case for ammunition, which has a wall of one or more windings of textile fibers, which are linked by a binding agent, characterized in that the binding agent of the wall consists of: a) by polymers which, when burned, do not form aggressive gases, in mixture with explosive products the decomposition temperature of which is above 1800 C; and / or b) nitric aromatic polymers, the decomposition temperature of which is greater than 1800 ° C. and which have on average two or more groups nitro by aromatic nucleus.   2 cartridge socket according to claim 1, characterized in that the percentage of polymers in the socket is between 10 and 50%, preferably between 10 and 20% and that the percentage of aromatic nitro polymers is between 10 and% . 3 cartridge case according to claim 1 a) or 2, characterized in that the proportion of explosive substance in the binding agent is between 30 and 70% by weight.