Combustible propellant charge case

Abstract

The invention relates to a combustible propellant charge case for ammunition dischargeable from a gun barrel, comprising cellulose, nitrocellulose, MO3 particles, wherein M = Mo and / or W, and cationic surfactant, wherein the average particle size d50 of the MO3 particles is 0.5–2.0 µm, the maximum particle size d100 of the MO3 particles is ≤ 20 µm, and the quotient of the average MO3 concentration in wt.% in a volume element of approximately 0.05 to 1.0 cm3 (cVE) at any desired point in the propellant charge case and the total MO3 concentration in wt.% (ctot) in the propellant charge case is cVE:ctot = 0.80–0 1.20.

Description

[0001] Combustible propellant case

[0002] The present invention relates to a combustible propellant case with MoOs and / or WOs particles, a method for producing the combustible propellant case and a use of the combustible propellant case for firing ammunition.

[0003] When ammunition is fired from a gun barrel, the burning of the propellant powder creates high temperatures and pressures, which lead to severe wear on the gun barrels, especially in the case of large-caliber projectiles such as those used in artillery guns and tanks.

[0004] To reduce wear, erosion-reducing additives, such as wax or paraffin, can be added to the propellant powder or the combustible propellant case enclosing the propellant powder, as described in DE 39 27 400 A1.

[0005] EP 1 227 295 A1 describes that erosion-reducing additives can be added to a propellant case in the form of oxides of rare earth elements or one of the elements of the sixth subgroup of the periodic table or polyoxymethylene.

[0006] EP 1 647 538 A1 describes the addition of polyacetylene or a mixture of WO3 or MoOs and CeO2 or La2O3 or Y2O3 in the form of particles to a propellant case to reduce erosion, with an average particle size of 1 to 10 pm and a maximum particle size of 30 pm. Tungsten trioxide (WO3) and molybdenum trioxide (MoOs), as additives to the propellant case, can reduce barrel erosion and thus barrel wear to a certain extent, presumably by capturing atomic hydrogen. However, barrel wear of this ammunition still requires improvement in order to reduce maintenance requirements, increase the service life of the weapon barrels, and in particular, improve the precision of the ammunition's advance, since an eroded barrel exhibits significantly reduced firing accuracy.

[0007] Therefore, it is an object of the invention to reduce barrel wear in ammunition fired from a weapon barrel, in particular in artillery or tank barrels.

[0008] This object is achieved by a combustible propellant charge casing according to patent claim 1, a method for producing a combustible propellant charge casing according to patent claim 11 and a use of a combustible propellant charge casing according to patent claim 15. Further features, embodiments and advantages emerge from the dependent claims and the description.

[0009] One aspect of the invention relates to a combustible propellant cartridge case for ammunition fired from a weapon barrel, comprising

[0010] - pulp,

[0011] - Nitrocellulose,

[0012] - 5 - 10 wt.% MOs particles, based on the total weight of the propellant case, where M = Mo and / or W, and

[0013] - 0.01 - 2 wt.% cationic surfactant, based on the total weight of the propellant case, wherein the average particle size dso of the MOs particles is 0.5 - 2.0 pm, the maximum particle size do of the MOs particles is < 20 pm, and the quotient of the average MOs concentration in wt.% in a volume element of about 0.05 to 1.0 cm 3 (CVE) at any location in the propellant case and the total MOs concentration in wt.% (c ges ) in the propellant case CVE : c ges = 0.80 - 1.20.

[0014] A further aspect of the invention relates to a method for producing a combustible propellant charge casing, comprising the steps

[0015] (a) preparing a slurry of cellulose, nitrocellulose, MOs particles, where M = Mo and / or W, and cationic surfactant in water,

[0016] (b) mixing the slurry,

[0017] (c) dewatering the slurry on a screen to produce a raw felt,

[0018] (d) pressing the raw felt and

[0019] (e) Drying to form a combustible propellant case.

[0020] According to the invention, MOs particles are understood to be MoOs particles (molybdenum trioxide particles) or WOs particles (tungsten trioxide particles). WO3 particles are preferred.

[0021] Within the scope of the invention, it was found that propellant charge cases of the prior art with metal oxide particles such as MoOs or WOs particles exhibit strong concentration fluctuations of the metal oxides in the propellant charge case and that this is at least one factor for the still excessive barrel wear after firing ammunition with corresponding propellant charge cases.

[0022] Surprisingly, the use of a cationic surfactant in the manufacturing process leads to a relatively uniform and small particle size of the MoOs and / or WOs particles and to a smaller concentration variation of the MoOs and / or WO3 in the combustible propellant case, thereby avoiding temperature and pressure peaks during pre-firing and thereby reducing barrel wear. Without being bound by the invention, it is assumed that the cationic surfactant, in conjunction with a relatively small particle size and narrow particle size distribution, counteracts sedimentation of the MoOs and WOs particles during the manufacturing process, thereby promoting effective recrystallization of the MoOs and WO3 in the pulp (slurry) and thus enabling a relatively uniform particle size distribution. On the other hand, the dispersing effect of the surfactant, i.e.Keeping the MoOs and / or WOs particles suspended promotes the particles' attachment to the nitrocellulose and pulp fibers, preventing the MoOs and / or WOs particles from settling due to gravity. This leads to less fluctuation in the concentration of the MoOs and / or WOs particles in the finished propellant case. This is particularly relevant for the MoOs and WOs particles used in the invention, since the density of these substances is particularly high.

[0023] The particle size and particle size distribution are determined using laser diffraction in a wet measurement (Malvern system, Mastersizer E, wet measurement in water in a cuvette). This yields a particle size distribution curve. xmeans that x volume percent of the particles have a diameter smaller than the specified value. For example, with a d50 value (average particle size) of 1 pm, 50 vol.% of the particles have a diameter of 1 pm (micrometer). With a d20 value (maximum particle size) of 10 pm, 100 vol.% of the particles have a diameter < 10 pm.

[0024] For the purposes of the invention, a surfactant is understood to be a substance that is surface-active and thus reduces the surface tension of a liquid or the interfacial tension between two phases, thus supporting the formation of dispersions such as suspensions. Cationic surfactants have positively charged groups, such as quaternary ammonium groups. For the purposes of the invention, polyamines are understood to be saturated, open-chain and / or cyclic organic compounds with terminal amino groups and optionally secondary and tertiary amino groups. Such a polyamine can be produced, for example, by reacting ethylenediamine and / or propylenediamine with ethylene oxide with complete or almost complete substitution of the oxygen atoms.Furthermore, for example, a reaction of ethylenediamine and / or propylenediamine with epichlorohydrin with complete or almost complete substitution of the oxygen and chlorine atoms is possible. Such polyamines can be in oligomeric or polymeric form. A cationic surfactant derived from a polyamine is, for example, the salt of a polyamine with an acid, such as acetic acid.

[0025] In a preferred embodiment of the invention, the cationic surfactant has two or more cationic groups. Preferably, the cationic surfactant is a salt of an organic polyamine and / or polyethyleneimine with an acid. The acid can be an organic or inorganic acid, preferably an inorganic acid, for example hydrochloric acid or sulfuric acid. Further preferred is a surfactant available under the trade name Paragas. Paragas is a mixture of various compounds, essentially the salt of a polyethyleneamine / imine with an acid. With these preferred cationic surfactants, particularly constant MOs concentrations can be achieved in the propellant case, i.e., small concentration variations, whereby particularly low barrel wear during pre-shot can be achieved.

[0026] The combustible propellant case according to the invention contains 0.01-2 wt.% cationic surfactant, preferably 0.05-1 wt.%, more preferably 0.07-0.8 wt.%, even more preferably 0.1-0.6 wt.%, particularly preferably 0.3-0.5 wt.% cationic surfactant. With these concentrations, very constant MOs concentrations can be achieved in the propellant case according to the invention and thus particularly low barrel wear during pre-firing. The combustible propellant case according to the invention is characterized in that the concentration of MoOs and / or WOs particles in the propellant case is more constant than in propellant cases of the prior art, in which the concentration fluctuates greatly within the propellant case and is also subject to significant fluctuations from case to case. A concentration difference of an average value of, for example, 8 wt.% of - 3 wt.% within known propellant charge cases, ie a minimum value of 5 wt.-% is usual. In the propellant charge case according to the invention, in contrast, the concentration fluctuations of the MoOs and / or WOs particles are smaller, preferably <1.5 wt.%, more preferably <1.0 wt.%, particularly preferably <0.7 wt.%, in particular <0.5 wt.%. In the axial direction of the propellant charge case, the concentration fluctuations are preferably even smaller, preferably <1.0 wt.%, more preferably <0.5 wt.%.

[0027] The MoOs and WOs concentrations are measured wet-chemically by cutting out, for example, a piece of the propellant case, e.g., punching it out, measuring 1 cm x 1 cm x the wall thickness of the propellant case (usually 3.3 mm). This piece is destroyed by fuming with concentrated nitric acid and then incinerating in a muffle furnace at 800 °C. The ash content of the preliminary sample (nitrocellulose pulp and cellulose without WO3) as well as the loss on ignition of the tungsten trioxide are taken into account. By determining the residual moisture in the sample, the analytical result can be expressed as a dry substance. m From balance ' 10 w(Talc, WO3) = - 7 — w z sc he) m Einwaage■ (100 - w(H20)) ■ (100 - GV) rriOutweight = Mass of the pellet used after annealing [g] mInput weight = Mass of the pellet used before annealing [g] W(H20) = Water content of the pellet used [%] GV = Loss on ignition of the talc or tungsten trioxide [%] w(ash) = Ash content of the preliminary sample, calculated on the dry substance basis [%]

[0028] To determine the total MoOs and / or WOs concentration, a wet-chemical measurement is carried out on the entire propellant case according to the above procedure. Alternatively, at least three wet-chemical measurements of approximately 0.05 to 1.0 cm each can be carried out according to the above procedure. 3 volume at randomly selected locations on the propellant case and the arithmetic mean is calculated. The total MoOs and / or WOs concentration (c ges ) in the propellant case is the total mass of MoOs and / or WO3 in the propellant case divided by the total mass of the propellant case.

[0029] The quotient of the average MOs concentration in wt.% in a volume element of about 0.05 to 1 .0 cm 3 (CVE) at any location in the propellant case and the total MOs concentration in wt.% (c ges ) in the propellant case is CVE : Cges — 0.80 - 1.20, preferably 0.85 - 1.15, most preferably 0.90 - 1.10, with M = Mo and / or W, preferably W.

[0030] The volume element from 0.05 to 1.0 cm 3 preferably has a volume of about 0.1 to 0.8 cm 3 , more preferably about 0.2 to 0.6 cm 3 , in particular about 0.33 cm 3More preferably, it is a continuous volume element. In a preferred embodiment of the invention, the volume element has the wall thickness of the propellant charge case. A propellant charge case typically has a length of approximately 30-90 cm (centimeters), a diameter of 100-160 mm (millimeters), and a wall thickness of approximately 2-4 mm, in particular 3.3 mm.

[0031] The volume element for determining CVE preferably has a size of 0.5 cm x 0.5 cm x 0.2 cm to 1.5 cm x 1.5 cm x 0.4 cm, preferably 0.5 cm x 0.5 cm x 0.33 cm to 1.5 cm x 1.5 cm x 0.33 cm, particularly preferably 1.0 cm x 1.0 cm x 0.33 cm. These volume elements, which have the wall thickness of the propellant charge casing as their thickness, thus reflect the deviations in the axial direction of the propellant charge casing over multiple measurements. In the axial direction, the deviation from the mean value is particularly small. For a volume element for the determination of CVE with a size of 0.5 cm x 0.5 cm x 0.2 cm to 1.5 cm x 1.5 cm x 0.4 cm, CVE : Cges is preferably 0.85 - 1.15, preferably 0.90 - 1.10, particularly preferably 0.92 - 1.08. This reflects the concentration variation in the axial direction.

[0032] In a preferred embodiment of the propellant case according to the invention, the average particle size dso of the MOs particles is 0.5 - 2.0 pm, the maximum particle size do of the MOs particles is < 20 pm, and the quotient of the average MOs concentration in wt.% in a volume element (CVE) at any point in the propellant case and the total MOs concentration in wt.% (Cges) in the propellant case CVE: c ge s = 0.85 - 1.15, preferably 0.90 - 1.10, particularly preferably 0.92 - 1.08, wherein the volume element has a size of 0.5 cm x 0.5 cm x 0.2 cm to 1.5 cm x 1.5 cm x 0.4 cm, wherein the propellant charge casing has a wall thickness and the 0.2 cm to 0.4 cm are the wall thickness of the propellant charge casing.

[0033] As an alternative to the wet-chemical determination described above, the MoO3 and / or WO3 concentration can be measured using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). For this purpose, a section of the propellant case is prepared, and an SEM-EDX measurement is performed on an area of ​​approximately 100 pm x 100 pm. The measurement is a surface measurement and reflects the Mo3 and / or WO3 concentration in the upper layer of the section. It is expressed as a weight percent. The wet-chemical determination as described above is preferred.

[0034] In a preferred embodiment of the invention, the MoOs and / or WOs particles have a relatively uniform particle size, i.e., the particle size distribution is comparatively narrow. This is reflected by a low d0 value compared to the d50 value. The d50 value of the MOs particles (MoOs and / or WOs particles) according to the invention is 0.5 - 2.0 pm, preferably 0.7 - 1.6 pm, particularly preferably 0.8 - 1.4 pm, and most preferably 0.9 - 1.1 pm. The dwo value of the MoOs and / or WOs particles is <20 pm, preferably <15 pm, further preferably <12 pm, particularly preferably <10 pm. With these particle sizes, very constant MOs particle concentrations can be achieved in the propellant charge case according to the invention, i.e.,particularly low concentration variations, which allows for low pipe wear during the advance shot, and in addition, these uniform particle sizes have the advantage that they themselves ensure low temperature and pressure peaks during the advance shot, which can reduce pipe wear even further.

[0035] A uniform particle size in the sense of a narrow particle size distribution is achieved by mixing the slurry in the process according to the invention in the presence of a cationic surfactant, preferably for at least 15 minutes. Mixing is preferably carried out by stirring. Without being bound by this according to the invention, it is assumed that the cationic surfactant surrounds the generally slightly negatively charged MoOs and / or WOs particles (MoOs and WO3 are slightly acidic in an aqueous environment), thereby keeping the MoOs and / or WOs particles in suspension and thus promoting recrystallization, i.e., dissolution and recrystallization.Even if a broad particle size distribution of the MoOs and / or WOs particles is used, after carrying out the process according to the invention, the particle size distribution in the propellant charge casing is very narrow, for example dso = 0.5 to 2.0 pm, preferably 0.8 to 1.4 pm, with do 15 pm, preferably < 12 pm, particularly preferably < 10 pm. A narrowing of the particle size distribution takes place and this ensures more uniform thermal stress and pressure stress in the weapon barrel, whereby thermal peaks and pressure peaks are avoided and barrel wear is reduced.

[0036] According to the invention, the average concentration of MO3 in the propellant charge case (total MO3 concentration) is 5-10 wt.%, preferably 6-9 wt.%, particularly preferably 7-8 wt.%, with M = Mo and / or W. M is preferably tungsten (W). In a preferred embodiment of the invention, the propellant charge case contains, in addition to the MoOs and / or WOs particles, less than 1 wt.%, preferably less than 0.5 wt.%, particularly preferably less than 0.1 wt.% of other metal oxide particles.

[0037] The combustible propellant case according to the invention preferably contains 45 - 65 wt.%, in particular 52 - 58 wt.%, nitrocellulose and / or 25 - 50 wt.%, in particular 33 - 40 wt.%, cellulose.

[0038] The method according to the invention comprises the steps

[0039] (a) preparing a slurry of pulp, nitrocellulose,

[0040] MOs particles, where M = Mo and / or W, and cationic surfactant in water,

[0041] (b) mixing the slurry, preferably for at least 5 minutes, more preferably at least 20 minutes, most preferably 30 minutes to 2 hours.

[0042] (c) dewatering the slurry on a screen to produce a raw felt,

[0043] (d) pressing the raw felt and

[0044] (e) Drying to form a combustible propellant case.

[0045] In a preferred embodiment of the invention, the slurry in step (a) contains 5-10 wt.% MOs particles, based on the total weight of pulp, nitrocellulose, MOs particles and cationic surfactant and / or 0.1-2 wt.% cationic surfactant, based on the total weight of pulp, nitrocellulose, MOs particles and cationic surfactant.

[0046] The method according to the invention preferably comprises the steps

[0047] (a) preparing a slurry (pulp) of cellulose, nitrocellulose, 5 - 10 wt.% MOs particles, based on the total weight of the propellant case, where M = Mo and / or W, and 0.1 - 2 wt.% cationic surfactant, based on the total weight of the propellant case, in water,

[0048] (b) mixing the slurry, preferably for at least 5 minutes, more preferably at least 20 minutes, most preferably 30 minutes to 2 hours.

[0049] (c) dewatering the slurry on a screen to produce a raw felt,

[0050] (d) pressing the raw felt and

[0051] (e) Drying to form a combustible propellant case.

[0052] The surfactant preferably partially deposits on fibers, so that the amount of surfactant in the sleeve is preferably somewhat lower than in the slurry used.

[0053] In a preferred embodiment of the process according to the invention, in step (a)

[0054] 45 - 65 wt% nitrocellulose,

[0055] 25 - 50 wt% cellulose,

[0056] 5 - 10 wt.% MoOs and / or WOs particles,

[0057] A slurry is prepared in water containing 0.1-2 wt.% cationic surfactant, the wt.% in each case based on the total mass of nitrocellulose, cellulose, MoOs and / or WOs particles and / or cationic surfactant, and optionally additives, stabilizers, and / or binder resin. It is understood that the sum of the weight percentages of the individual components equals 100 wt.%. A preferred stabilizer is akardite.

[0058] The pressing of the raw felt in step (d) preferably takes place at 20-175 °C, more preferably 100-175 °C, most preferably 120-150 °C. Drying preferably takes place under ambient conditions, in particular in a so-called standard climate.

[0059] In a preferred embodiment of the process according to the invention, a stabilizer is additionally added in step (a). The stabilizer is preferably acardite (diphenylamine). This stabilizer serves in particular to stabilize the nitrocellulose.

[0060] In a further preferred embodiment of the process according to the invention, a binder resin is additionally added in step (a). The binder resin can be added, for example, in the form of binder resin particles. During subsequent compression at elevated temperature, the binder resin melts and bonds the fibers together. The binder resin is preferably a polymer or a polymer blend of polystyrene-polybutadiene rubber (latex).

[0061] In a preferred embodiment of the invention, a lacquer is applied to the surface of the propellant case after step (e). A nitrocellulose lacquer is preferred. When using a lacquer, the binding resin described above is preferably added in step (a).

[0062] In a further preferred embodiment of the process according to the invention, a plastic is applied to the surface of the pressed raw felt between steps (d) and (e). The plastic is preferably a polyurethane (PU). This is preferably done by immersing the pressed raw felt in a bath of polyols with isocyanate crosslinking agents and subsequent drying, during which the polyurethane cures.

[0063] The method according to the invention preferably comprises the steps

[0064] (a) preparing a slurry (pulp) of cellulose, nitrocellulose, MOs particles, where M = Mo and / or W, and cationic surfactant in water,

[0065] (b) mixing the slurry, preferably for at least 15 minutes, (c) dewatering the slurry on a screen to produce a raw felt,

[0066] (d1 ) Pressing the raw felt,

[0067] (d2) applying a plastic to the surface of the pressed raw felt, preferably a polyurethane and

[0068] (e) Drying to form a combustible propellant case.

[0069] The method according to the invention also preferably comprises the steps

[0070] (a) preparing a slurry (pulp) of cellulose, nitrocellulose and binder resin particles in water, adding MOs particles, where M = Mo and / or W, and cationic surfactant in water,

[0071] (b) mixing the slurry, preferably for at least 15 minutes,

[0072] (c) dewatering the slurry on a screen to produce a raw felt,

[0073] (d) pressing the raw felt and

[0074] (e) drying to a combustible propellant case,

[0075] (f) applying a varnish to the surface of the combustible propellant case, preferably a nitrocellulose varnish.

[0076] The slurry (pulp) is preferably mixed using conventional stirring tools, such as rotating blades. The slurry is dewatered by pouring the slurry onto a sieve, allowing the water to flow through the holes in the sieve, possibly assisted by a vacuum. The raw felt is then pressed onto this sieve with a matching mating piece, thus producing a slightly moist propellant case. This propellant case is then dried to produce the combustible propellant case according to the invention.

[0077] The present invention also relates to the use of the propellant case according to the invention for firing ammunition, in particular artillery ammunition. The invention is further explained below using two examples:

[0078] Example 1 :

[0079] Production of combustible shells for tank cannon ammunition

[0080] 1. Pulp boards are pulverized into a pulp in water (2,627 liters of process water). This occurs in a container with a rotating blade at the bottom. The pulp weighs 78.8 kg. The pulp is then ground in a refiner. A further 1,200 liters of process water are added.

[0081] 2. Nitrocellulose is stirred into the fiber pulp. The total weight is 120.0 kg.

[0082] 3. Check the fabric density approx. 8%

[0083] 4. Addition of another 1600 liters of process water.

[0084] 5. Addition of Paragas: The Paragas is mixed with water and added to the mixture while stirring.

[0085] 6. The stabilizer Akardite is added: The Akardite is suspended in water and ground. It is then added to the mixture while stirring.

[0086] 7. 16.8 kg of WOs particles are suspended in 32 liters of water and added to the mixture while stirring.

[0087] 8. The mixture is pumped into the target container and diluted with process water.

[0088] 9. The fibers are separated by suction onto sieve forms in special basins that are in communication with the target container. This creates the raw felt.

[0089] 10. The raw felts are then pressed at approximately 170 °C. During pressing, the water from the raw felt is removed by vacuum. This step produces the core in its defined shape. 11. The pressed cores are PU-impregnated by briefly immersing them in a bath of polyols with isocyanate crosslinking agents, followed by drying and curing in a drying tunnel.

[0090] 12. Conditioning in standard climate (drying).

[0091] 13. Mechanical cutting and chamfering.

[0092] Example 2:

[0093] Production of combustible shells for artillery ammunition

[0094] Steps 1 -3 are identical.

[0095] Step 4 involves the addition of binding resin particles. These binding resin particles are later melted during compression and bond the fibers together. These are polymers made of polystyrene-polybutadiene latex.

[0096] Raw felt production and pressing analogous to the above process.

[0097] Step 11 is omitted here.

[0098] Steps 12 and 13 are carried out analogously.

[0099] The final step is painting. This is done with an NC paint containing the appropriate color pigment.

[0100] It is understood that the features mentioned above and those to be explained below can be used not only in the specified combinations, but also in other combinations or alone, without departing from the scope of the present invention. The advantages of features or combinations of several features mentioned are merely exemplary and can be used alternatively or cumulatively. The combination of features of different embodiments of the invention or of features of different patent claims is possible, deviating from the selected references to the patent claims.

Claims

Claims 1 . Combustible propellant case for ammunition fired from a gun barrel, comprising - pulp, - Nitrocellulose, - 5 - 10 wt.% MOs particles, based on the total weight of the propellant case, where M = Mo and / or W, and - 0.01 - 2 wt.% cationic surfactant, based on the total weight of the propellant case, wherein the average particle size dso of the MOs particles is 0.5 - 2.0 pm, the maximum particle size do of the MOs particles is < 20 pm, and the quotient of the average MOs concentration in wt.% in a volume element of about 0.05 to 1.0 cm 3 (CVE) at any location in the propellant case and the total MOs concentration in wt.% (c ges ) in the propellant case CVE : c ge s = 0.80 - 1.

20.

2. Combustible propellant case according to claim 1, characterized in that the average particle size dso of the MOs particles is 0.8 - 1.4 pm.

3. Combustible propellant case according to claim 1 or 2, characterized in that the d o value of the MOs particles is < 12 pm.

4. Combustible propellant case according to one of the preceding claims, characterized in that the propellant case contains 7 - 8 wt.% MO3 particles and / or 0.05 - 1 wt.% cationic surfactant.

5. Combustible propellant charge casing according to one of the preceding claims, characterized in that CVE : c ges = 0.85 - 1.

15.

6. Combustible propellant charge casing according to one of the preceding claims, characterized in that the volume element has a size of approximately 0.5 cm x 0.5 cm x 0.2 cm to 1.5 cm x 1.5 cm x 0.4 cm, wherein the propellant charge casing has a wall thickness which is 0.2 cm to 0.4 cm the wall thickness of the propellant charge casing and cvE:c g es = 0.90 - 1.

10.

7. Combustible propellant case according to one of the preceding claims, characterized in that the quotient of the average MO3 concentration in wt.% in a volume element of about 0.33 cm 3 (CVE) at any point in the propellant case and the total MO3 concentration in wt.% (c ges ) in the propellant case CVE : c ges = 0.80 - 1.20 is 8. Combustible propellant case according to one of the preceding claims, characterized in that M = W.

9. Combustible propellant case according to one of the preceding claims, characterized in that the cationic surfactant contains two or more cationic groups.

10. Combustible propellant case according to one of the preceding claims, characterized in that the cationic surfactant is a salt of an organic polyamine and / or polyethyleneimine with an acid.

11. A method for producing a combustible propellant charge casing according to any one of claims 1 to 10, comprising the steps (a) preparing a slurry of cellulose, nitrocellulose, MOs particles, where M = Mo and / or W, and cationic surfactant in water, (b) mixing the slurry, (c) dewatering the slurry on a screen to produce a raw felt, (d) pressing the raw felt and (e) Drying to form a combustible propellant case.

12. The method according to claim 11, characterized in that the slurry in step (a) contains 5 - 10 wt.% MOs particles, based on the total weight of pulp, nitrocellulose, MOs particles and cationic surfactant and / or 0.1 - 2 wt.% cationic surfactant, based on the total weight of pulp, nitrocellulose, MOs particles and cationic surfactant.

13. The method according to claim 11 or 12, characterized in that the cationic surfactant contains two or more cationic groups, preferably the cationic surfactant is a salt of an organic polyamine with an acid.

14. The method according to any one of claims 11 to 13, characterized in that in step a) a stabilizer is additionally added, preferably acardite.

15. Use of a combustible propellant charge casing according to one of claims 1 to 10 for firing ammunition, in particular artillery ammunition.