EP1241151A1 - Temperature-insensitive propellant powder - Google Patents

Abstract

The proposed TLP has a temperature-independent burning behavior and high ballistic stability. The manufacturing process is based on a perforated bulk powder grain, which is treated in a mixing device with a solid, a cone-stabilizing moderator or desensitizer (and optionally with a radical generator) and a low-viscosity liquid. With a minimal amount of solid, moderator or desensitizer and liquid, the shape function is influenced by continuous mixing to such an extent that the gas formation rate is practically independent of the powder temperature. As a result, the muzzle energy at normal temperature and especially at low operating temperatures can be significantly increased compared to ordinary TLP. In the propellant charge powder according to the invention, the grain of which has at least one cavity opening with an opening to an outer surface of the grain, the opening being closed by a pin, the pin has a temperature-dependent mobility. The mobility is such that there is a higher mobility at a lower application temperature than at a higher application temperature, so that the peg permits faster hole burn-off at a lower application temperature than at a higher application temperature. <IMAGE> <IMAGE> <IMAGE>

Description

Technical area

The invention relates to a propellant powder, the grain of which has at least one with an opening has an opening opening to an outer surface of the grain, the opening is closed with a pin. Furthermore, the invention relates to a method for Production of such a powder.

State of the art

Propellant powder (TLP) for conventional barrel weapon systems must be procured in this way be under different environmental conditions (system specific Factors) work properly and safely. Large temperature differences when using weapons are one of the most important influences that a propellant charge manufacturer or an ammunition manufacturer has to consider. So it can easily happen that Local and / or global climate conditions Safe drive solutions in one temperature range from - 54 ° C to + 63 ° C / + 71 ° C (and even up to + 100 ° C in aircraft use).

Since TLP burns naturally depending on the temperature (physical laws), there is usually a considerable amount of fire in the temperature range mentioned Pressure differences.

As with all weapon systems, tube weapons are in constant demand after increased performance (e.g. higher kinetic energy of the projectile in the tank, longer ranges for artillery shells, shorter flight times for anti-aircraft missiles [Machine gun], higher probability of first shot, etc.).

Here are performance increases, which are realized by means of new weapon developments have to be very expensive.

For cost reasons, there is therefore great interest in defense technology, the desired ones Performance improvements in existing weapon platforms to accomplish (increase in combat value).

The desired performance improvements can only be achieved by exhausting all reserves and through a combination of suitable measures (optimization of internal ballistic Operations) can be achieved with the weapon-technical framework unchanged stay.

• Bessere Leistungsfähigkeit der Grundrezeptur des Treibladungspulvers durch die Verwendung von Rezepturen mit hoher Force (spezifische Energie bzw. Pulverkraft).
• Erreichen maximaler Schüttdichten (durch hohe Dichten bzw. optimale Oberflächeneigenschaften des TLP) in den gegebenen Hülsenvolumen.
• Erhöhung der Progressivität beim TLP-Abbrand.
• Minimierung bzw. Eliminierung der Temperaturabhängigkeit des TLP-Abbrands

Such measures are:

• Better performance of the basic formulation of the propellant powder by using recipes with high force (specific energy or powder power).
• Achieve maximum bulk densities (due to high densities or optimal surface properties of the TLP) in the given sleeve volume.
• Increasing the progressiveness of the TLP burnup.
• Minimization or elimination of the temperature dependency of the TLP burnup

The problem with providing these new high performance TLPs is there now in avoiding unwanted side effects, i.e. on the requested elevated Performance level the full extended system compatibility with regard to pipe (erosion, Corrosion), weapon (peak gas pressure) and the environment (avoidance of environmental problems To ensure recipe components).

Finally, it is desirable that the required high performance TLP be inexpensive are producible, i.e. with easily accessible, inexpensive starting materials and with simple processes can be manufactured.

According to the physical laws, the burning speed depends on the Autoignition temperature and the initial temperature of the propellant body. This behavior leads to the well-known property of such classic blowing agents, that their linear burning speed more or less from the initial temperature depends. This inevitably also means that peak gas pressure and muzzle velocity have a more or less steep temperature gradient. This The temperature-dependent performance of such blowing agents has considerable disadvantages, e.g. small First shot hit probability and much lower projectile energy at normal and especially at low operating temperatures. The limiting factor is always that of maximum peak gas pressure occurring at high temperatures.

There is little work in the literature dealing with weapon system modifications or deal with propellant powders that provide constant, temperature-independent performance provide.

For example, US Pat. No. 4,106,960 mentions a surface coating in which a 19 - hole propellant powder with 18% polymethyl methacrylate (mol. weight> 100,000), 3.4% titanium oxide, 1.9% diphenylcresyl phosphate and 100% toluene (all percentages based on the TLP) is coated in 20 application and drying cycles. About 10 to 20 parts by weight (based on the amount of TLP) are preferred inert material mounted on the TLP. This corresponds to an inert coating layer from 100 to 200 microns. This greatly delays the ignition of the TLP. You mix this highly treated TLP with untreated TLP, which is an instantaneous ignition has, it is possible to invert the temperature dependence of the propellant charge powder. A mixture of treated grain and untreated grain showed in the pressure bomb (where all material burns) a temperature-independent behavior, the burning time was not specified. The temperature-independent behavior was in the gunfire Not checked.

In a review by D. L. Kruczynski, J. R. Hewitt, Technical Report BRL-TR-3283 (1991) temperature compensation techniques and technologies are mentioned in which desensitizers have a certain influence on the reduction of the temperature coefficient should have. However, the mechanism still seems to be unclear. Will continue the production of TLP suggested which brittle fracture (surface enlargement) at low firing temperatures for a liveliness increase and compression the soft grain and thus the holes (surface reduction) at high Shot temperatures used for a reduction in liveliness. Such processes are difficult to control and involve an immense security risk.

Another proposal for reducing the temperature dependency relates to the adaptation of the chamber volume depending on the powder temperature.

Another publication that also deals with the reduction of temperature sensitivity of propellant powders, especially for artillery use, and similar arguments used, comes from T. T. Nguyen, R. J. Spear, Department of Defense, Australia, DSTO-TR-0102 (1994). It is noted there that no additive can be found was able to reduce the temperature dependence of the powder burn.

Presentation of the invention

The object of the invention is to provide a propellant charge powder of the type mentioned in the introduction, that shows a largely temperature-independent combustion behavior without essential Losses in other properties have to be accepted. In particular neither the ignition behavior nor the chemical and ballistic stability of the Propellant powder deteriorate.

The solution to this problem is defined by the features of claim 1. According to the A propellant charge powder of the type mentioned at the outset is characterized in that that the peg has a temperature-dependent mobility that is such that at lower Application temperature there is a higher mobility than at a higher application temperature, so that the peg is stronger at a lower application temperature Hole burn-up permits than at higher application temperatures.

The physical conditions given at a low application temperature ensure that the pins are torn out of their position on the first pressure wave and release the holes. The contact point between the pin and the perforated wall is given, is quasi fragile at low temperature. At a higher temperature on the other hand, it is quasi tough and better withstands the ignition pressure wave. that the "brittleness" or "toughness" of the anchorage are statistical parameters. It is not about having each peg exactly the same behavior on the pressure wave shows. Rather, it is sufficient if the whole of the cones of all powder grains in the Statistically, ammunition shows this characteristic behavior. Of course it is necessary to make trials to a certain extent for a particular Ammunition to achieve the desired temperature independence. Because of the Statement on how to choose the mobility of the cones however, the specialist will recognize which optimization he has to carry out in the individual case.

The hole erosion is used to characterize the extent to which the holes run out Combustion processes contribute to the rate of gas formation. The more holes released the more surface is available for the erosion. Accordingly more gas is produced from the grain per unit of time.

It should be mentioned that only the compressed and anchored part of the material in the hole is understood as a pin. The relative loose material that is under the compacted part of the filling does not act as Pin in the sense of the invention and is therefore not named as such. It understands in practice that there is not necessarily a clear limit to the cone demarcates. The pin can also "flow" into the rest of the hole filling. As far as the invention is concerned, one section will be sufficient in any case give high tightness, which withstand an ignition pressure wave in a controlled manner can.

The invention has various approaches compared to the approaches proposed in the prior art Benefits. First of all, it should be noted that they are basically for two- and multi-base, perforated propellant powder (TLP) suitable for gun weapon applications. It can be Manufacture propellant powder that has a temperature-independent combustion behavior, can be easily initiated by conventional means of ignition and also via a have high ballistic stability (service life). Because of the temperature independence (more or less constant gas formation rate) the powder energy Make optimal use of the entire temperature range.

Trials have shown that it can by combining the following internal ballistic optimization and improvement measures is possible with introduced Weapon systems a performance increase (muzzle energy) of 10% and more to achieve.

The cone should preferably consist of a substance contained in the green grain (i.e. the untreated one perforated TLP), is not soluble. This ensures that the anchoring of the pin in the opening and thus the mobility of the pin is not can change through diffusion processes. The anchoring is essentially determined by surface parameters at the level of the grain or cone structure.

The pin preferably consists essentially of an inert solid. Depending on Powder temperature is more or less strongly affected by the pressure wave of the ignition pushed the cavity in. By moving the pin, the active surface becomes increases and consequently the gas development per unit of time. At relatively lower The initial temperature quickly disengages from the anchor. Thereby the flammable TLP surface is increased almost instantaneously. At a relatively high powder temperature the anchorage of the peg, on the other hand, is quite resistant and the flammable TLP surface is reduced to a minimum.

A solid with a grain size in the range of 0.01 to 100 micrometers can be used become. The grain size will have to be matched to the size of the opening. If the grains of the solid are relatively large, it is difficult to enter the opening be introduced. The grain size is typically in the range from 0.1 to 50 Microns.

However, it is not imperative that the solid be inert. It can also contain energy. However, it has to burn and burn less quickly than the green grain.

Suitable inert solids are e.g. Graphite, talc, titanium oxide, carbon black, potassium sulfate, potassium cryolite and / or calcium carbonate. There are also other substances that can be used do not react with the green grain. The substances mentioned can both can be used individually as well as in connection with each other.

The invention is not limited to the fact that the pin consists exclusively of inert substances consists. It is possible that small amounts of an energetic solid add, in particular nitrocellulose, hexogen, octogen, nitroguanidine, nitrotriazole, Ethylenedinitramine, ethyltetryl, ammonium picrate, trinitrotoluene, trinitrobenzene, Tetranitroaniline etc., strong oxidizing agents may also be included, such as Ammonium nitrate, potassium nitrate, ammonium perchlorate, potassium perchlorate etc., if these have no incompatibilities with the selected recipe. Attention should be paid to this be that the stability or resistance of the pegs formed in the openings (Perforations) compared to the ignition shock wave at higher powder temperatures get lost.

Compounds with a melting point are suitable as admixable energetic solids above about 80 ° C. These solids must not have high sensitivity to impact or friction exhibit. A selection of highly explosive and therefore only very limited suitable substances are in R. Meyer, Explosivstoffe, Verlag Chemie 1979, page 121 ff. listed.

The pin preferably has a melting temperature which is above a manufacturing, Storage and / or application temperature, in particular above 90 ° C.

The propellant powder is typically a two- or multi-base single- or multi-hole powder. That is, the grain is cylindrical (with an outer diameter of, for example, 1 mm to 20 mm or preferably 3 mm to 15 mm) and preferably has 7 to 19 axially continuous Holes. The ratio of grain diameter to grain length is usually in the range between 0.3-2.0, preferably 0.8-1.2. Other powder geometries, e.g. Rosette shape, Hexagon shapes are also possible.

The diameter of the holes is z. B. in a range of 0.03 to 0.5 mm in particular 0.1 to 0.3 mm. Finer holes are advantageous in the context of the invention. It can then work with smaller amounts of inert material. In addition, the Better control the quality of the anchoring of the pins. Typically they are compact (compressed) cones have a length to diameter ratio in the range of 5 to 60.

The green grain can be made in a known manner by pressing a solvent-containing or solvent-free powder dough or wrap with or without explosive oil additives in one Extrusion press or obtained by extrusion.

The cavities closed off by the pins are axially continuous channels a void volume that is a multiple of a volume of a compact spigot is.

To produce the propellant powder that burns independently of the temperature, the Introduced into the opening and solidified and fixed in the form of a pin, that the peg has a temperature-dependent mobility that is such that at lower Application temperature given a higher mobility (displaceability in the hole) than at a higher application temperature, so that the pin at a lower application temperature allows faster hole erosion than at a higher temperature.

The solid is preferably in the grain with the help of a moderator, in particular one insoluble moderator, and a volatile liquid introduced into the opening. The whole thing takes place in a mixing apparatus, e.g. B. a drum instead. With the rotation the mixture of moderator, liquid and solid gradually by the powder mass pressure stuffed into the holes of the grain or the wet mixture works under Influence of the powder mass pressure into the holes. It can be said that fill the holes of the TLP relatively quickly with the dry solid. For the invention On the other hand, it is important that there is a condensed at the entrance of the hole Section is formed from solid, which is the ignition pressure wave among the specific can also withstand the desired conditions. It has been shown that at finished grain the density of the solid in the holes from the outside towards the inside decreases, the relatively loose mass located under the compacted pin, for the control of the hole erosion is of no significant importance.

The green grain, the solid and the moderator are mixed in with a liquid a mixing apparatus at a temperature in the range of 0 ° C to 90 ° C during one Treatment duration between 10 minutes and 3 hours and with a rotation speed the mixing apparatus processed between 2 and 30 revolutions per minute.

According to a preferred embodiment, a moderator is used who is radical can be networked. A radical generator is also used to crosslink the solid.

The solid and the moderator are in the mixing apparatus in the smallest possible Amount of z. B. 0.001% by weight to 4% by weight based on the weight of the untreated Grünkorns used. Typically, the solid and the moderator are in one quantity of significantly less than 1% by weight in the drum of the mixing apparatus.

The low-viscosity liquid is also in a similar amount in the mixing apparatus added: 0.1% by weight to 5% by weight, based on the weight of the untreated grain. Low viscosity is a liquid in the present context if it is associated with the dissolved moderator can be easily transported at room temperature. It can be low molecular weight common solvents such as water, alcohol, toluene, cyclohexane etc. can be used.

A radical generator can e.g. B. in an amount of 0.1 mol% to 5 mol% based on the molar amount of the networkable moderator are used, the radical generator at Surface treatment temperature in the mixing apparatus a high disintegration stability having. The disintegration time during the surface treatment is for half of the radical generator for example greater than 10 hours. In contrast, at the polymerization temperature the radical generator should quickly break down into radicals. Here the decay time for the Half of the radical generator should be less than 1 hour.

The propellant powder must be flushed with inert gas or vacuum / flushed can be freed from atmospheric oxygen with inert gas at room temperature after it has been mixed with the networkable moderator and has been treated with an initiator.

The moderator is typically networked under inert gas at normal pressure a temperature of less than 90 ° C and for a period of less than that six-fold decay half-life of the radical generator was carried out at this temperature.

Particularly suitable as uncrosslinked moderators are polyvinyl alcohol, poly (α-methylstyrene) Poly (vinyl alcohol-co-vinyl acetate), poly (vinyl alcohol-co-ethylene), Polybutadiene diol, polybutadiene diol dimethacrylate or polybutadiene diol diacrylate or longer chain Hydrocarbons such as waxes. Because these moderators in the TLP matrix don't are soluble, they remain in the cone and on the TLP surface. A diffusion into the TLP grain or away from the TLP interface does not take place.

The liquid is water, hexane, cyclohexane, toluene or a mixture of water / ethanol, Water / methanol, water / acetone, ethanol / cyclohexane or toluene / hexane used.

As networkable moderators such. B. the following substances are applicable: hexanediol diacrylate, Dipropylene glycol diacrylate, ethylene glycol dimethacrylate, tetraethylene glycol diacrylate, Trimethylolpropane triacrylate, triethylene glycol diacrylate, propoxylated glycerol triacrylate, Pentaerythritol tetraacrylate, ethoxylated bisphenol A diacrylate, propoxylated Neopentyl glycol diacrylate, ethoxylated neopentyl glycol diacrylate, polyethylene glycol diacrylate, Polybutadiene diol diacrylate, polybutadiene diol dimethacrylate, Polyethylene glycol dimethacrylate, polypropylene oxide diacrylate.

The liquid can be evaporated while rotating from the open mixer be removed. The finished propellant powder is then during stored for several days at an elevated temperature (e.g. 3 days at 60 ° C) to remove residual solvent and remove other volatile components.

The perforated TLP can be of any recipe and dimension. So they can For example, be made from the following energy sources:

Nitrocellulose with different degrees of nitration, polyglycidyl nitrate, polyglycidyl azide, PolyNIMMO, PolyAMMO, PolyBAMO, ethylene glycol dinitrate, diethylene glycol dinitrate, Nitroglycerin, butane triol trinitrate, metriol trinitrate, nitroguanidine, hexogen, octogen, alkyl NENA, CL-20, DNDA57, NTO, PETN, etc.

The perforated TLP can, if appropriate, be used for additives known in powder production Stabilization, pipe protection, softening and flare control included. Known Additives to increase stability, which are suitably used such as Akardit II (CAS No. 724-18-5), Centralit I (CAS No. 90-93-7), Centralit II (CAS No. 611-92-7), 2-Nitrodiphenylamine (CAS No. 836-30-6) and Diphenylamine (CAS No. 122-39-4), for Tube protection, e.g. talc (CAS No. 14807-96-6), titanium dioxide (CAS No. 13463-67-7), Calcium carbonate (CAS No. 1317-65-3) or magnesium silicate (CAS No. 14807-96-6), for Softening such as camphor (CAS No. 76-22-2) or dibutyl phthalate (CAS No. 84-74-2), and for fire suppression such as potassium sulfate (CAS No. 7778-80-5) or potassium cryolite. Furthermore, the green powder can also contain other known additives to improve the ignition behavior and included to modulate the combustion behavior. All the additives mentioned can be added to the powder dough during green grain production, i.e. they are therefore evenly distributed in the grain matrix. The total amount of these additives in the Green grain is preferably between 0-20% by weight, based on the nitrocellulose content between 0.1-5% by weight. However, it is also possible to use the additives according to the invention To bring in surface treatment.

From the following detailed description and the entirety of the claims there are further advantageous embodiments and combinations of features of the invention.

Brief description of the drawings

Fig. 1a-c

Gegenüberstellung der Versuchsergebnisse zu FM 2032n/9;

Fig. 2a-c

Darstellung der angebrannten TLP-Körner;

Fig. 3a-c

Druckbombenversuche mit unbehandeltem Grünkorn FM2708n und mit Muster FM 2712n und FM 2758n;

Fig. 4a-b

Darstellung des Druckverlaufs und des Spitzengasdrucks in Abhängigkeit von der Temperatur bei Waffenbeschuss;

Fig. 5a-c

Darstellung der dynamischen Lebhaftigkeiten des unbehandelten, des behandelten und des gealterten TLP in der Druckbombe;

Fig. 6

Konzentrationsprofile des vernetzten Moderators (propoxyliertes Glycerintriacrylat) vor und nach der beschleunigten Alterung (4 Wochen, 71°C);

Fig. 7

Konzentrationsprofile des vernetzten Moderators Ethylendiglycoldimethacrylat vor und nach der beschleunigten Alterung (4 Wochen, 71°C);

Fig. 8a-c

Reduktion der Temperaturabhängigkeit des Abbrands und ballistische Stabilität für unbehandeltes TLP, für behandeltes TLP nach 4 Wochen bei 21°C und für behandeltes TLP nach 4 Wochen bei 63°C;

Fig. 9a-d

Druckbombenbeschüsse bei verschiedenen Pulvertemperaturen des Grünkorns (Fig. 9a), des behandelten Pulvers (Fig. 9b), des beschleunigt gealterten, behandelten Pulvers (Fig. 9c) und einer Mischung aus 70 Gew.% Grünkorn und 30 Gew.% behandeltem Korn (Fig. 9d);

Fig. 10a-b

Druckbombenbeschüsse bei einerseits gasdicht gelagertem und andererseits künstlich gealtertem TLP.

The drawings used to explain the exemplary embodiment show:

1a-c

Comparison of the test results for FM 2032n / 9;

2a-c

Representation of the burnt-in TLP grains;

3a-c

Pressure bomb tests with untreated green grain FM2708n and with samples FM 2712n and FM 2758n;

4a-b

Representation of the pressure curve and the peak gas pressure as a function of the temperature at gunfire;

5a-c

Representation of the dynamic vivacity of the untreated, the treated and the aged TLP in the pressure bomb;

Fig. 6

Concentration profiles of the cross-linked moderator (propoxylated glycerol triacrylate) before and after accelerated aging (4 weeks, 71 ° C);

Fig. 7

Concentration profiles of the networked moderator ethylene diglycol dimethacrylate before and after accelerated aging (4 weeks, 71 ° C);

8a-c

Reduction of the temperature dependence of the burn-up and ballistic stability for untreated TLP, for treated TLP after 4 weeks at 21 ° C and for treated TLP after 4 weeks at 63 ° C;

9a-d

Bombing at different powder temperatures of the green grain (Fig. 9a), the treated powder (Fig. 9b), the accelerated aged, treated powder (Fig. 9c) and a mixture of 70% by weight green grain and 30% by weight treated grain (Fig 9d);

Figures 10a-b

Bombardment of pressure bombs on the one hand in a gas-tight storage and on the other hand artificially aged TLP.

Ways of Carrying Out the Invention

In order to obtain the temperature-independent TLP according to the invention, a special one Surface treatment carried out:

For this purpose, the perforated green grains in a polishing drum with a solid, a cone-stabilizing moderator and a low-viscosity liquid speak at a certain temperature for a certain time at a certain time speak Rotational speed mixed. The individual surface treatment materials must be compatible with the TLP green grain.

The compatibility must be determined from case to case using suitable measurement methods. So z. B. intensive mixtures of green grain and surface treatment materials at 80 ° C in the heat flow calorimeter (WFK) for extensive heat development examined or the surface treatment material is in excess Quantities applied to the green grain or diffused into the green grain. These samples are subjected to the 90 ° C weight loss test or examined in the WFK. Another Test to determine the compatibility is the determination of the deflagration temperature such surface treatment materials / green grain mixtures.

To the solid:

The solid used can be a pure substance or a mixture of substances act from different solids. It is important that the average grain size of the Solid or the solid mixture is in a favorable range if the solid or the solid mixture is not soluble in the low-viscosity liquid. The solid or the solid mixture should be easily in the hole with the help of the mixing apparatus be insertable. Furthermore, it should compress well so that the pin is sufficient Has firmness. For example, the grain size of the solid should not be larger than 1/10 of the Hole diameter.

These grain sizes are in the range between 0.01 microns and 200 microns, preferably in Range 0.1 to 50 microns. (In the experimental examples described below, the Grain size in the range of 0.5 to 45 microns.) The liquid and the solid as well the solid / liquid ratio should be chosen so that the solid particles do not agglomerate, but keep their full mobility. This is important for one efficient closing of the perforations at their outer ends.

If the solid or mixture of solids is soluble in the low-viscosity liquid logically, the average grain size does not matter.

Solids or solid mixtures in the liquid used are preferred are not soluble.

Basically, any solid or mixture of solids can be used chemically stable within the application temperature range of the TLP and with the TLP formulation is compatible and therefore does not negatively affect the chemical life. In addition, the solid can be used in the entire manufacturing, bombardment and storage temperature range do not melt and do not become too essential during the entire service life Sublimate portions of the TLP grain and / or diffuse into it. To be favoured Substances selected whose melting point is at least 10 ° C - 20 ° C above the maximum Operating temperature. Substances with a melting point above are preferred have of 90 ° C and are insoluble in the TLP recipe or at most only very have low solubility in it.

Solids or solid mixtures which have a positive are also preferred Influence the TLP (LOVA properties = Low Vulnerability Ammunition, high Bulk density, good pourability, erosion-reducing, fire-retardant, high energy content, electrical conductivity and good ignitability).

The solids or their mixtures are primarily inert substances.

For reasons of ignitability, the TLP must be made of inert solids or their mixtures the smallest possible amounts are used. Relate to the green grain between 0.001 and 4 percent inert solids or solid mixtures are used, preferably between 0.01 and 2 percent.

Examples of inert solids that can be used pure or as mixtures, are graphite, talc, titanium oxide, potassium cryolite, tungsten trioxide, molybdenum trioxide, Magnesium oxide, boron nitride, potassium sulfate, acardite, centralite, calcium carbonate, oxalamide, Ammonium carbamate, ammonium oxalate, etc. Polymers and Copolymers with or without functional groups, linear, branched or cross-linked.

About the cone stabilizing moderator:

Solid or liquid substances are used as moderators. In doing so, the firm Moderators in the low-viscosity liquid, which is used as a third component will solve. Liquid moderators or moderator solutions can in the low-viscosity Liquid is also present as an emulsifier.

In principle, all solid and liquid substances that have good chemical compatibility with the basic recipe of the green grain and low volatility are suitable as moderators (eg vapor pressure at 21 ° C of <10 ^-2 bar). The moderator can be used as a pure substance or as a mixture of substances.

The moderators used are generally inert substances. But it is quite possible that energetic "moderators" can be used: However, these must be insensitive to the mechanical stress during the surface treatment process, in later ammunition processing or ammunition transport and its use.

The amounts of moderators or moderator mixtures used are between 0.001 and 4%, preferably between 0.01 and 2%.

The moderator can be either soluble or insoluble in the TLP matrix. Is the moderator soluble, it is also called a desensitizer and can also be used accordingly this function known per se can be used.

When using a moderator that is soluble in the TLP matrix, surface treatment is formed a concentration gradient in the outermost TLP layer. This concentration gradient can degrade through diffusion during the TLP lifespan, which inevitably changes the burning properties of the TLP. This usually manifests itself in higher ones Vivacity and top gas pressures, making the ballistic properties unfavorable influenced and in extreme cases can destroy the weapon.

This ballistic instability of the TLP (caused by diffusion processes) must not occur. Therefore, the problem of moderator diffusion is of central importance in the Surface treatment from TLP. The diffusion phenomena are of the composition of the TLP, depending on the type of moderator used and the temperature.

If two- or multi-base TLPs with high explosive oil concentrations are used, this is the case the diffusion of moderators is relatively favored. Therefore, the inventive Surface treatment can be designed so that during TLP storage no or only a slight diffusion-related change in the interior ballistic properties occur. If moderately diffusing moderators are used, either sufficient small quantities are used, or it must be ensured that the diffusion process before the ammunition is finished is practically complete.

1.) Man verwendet Moderatoren, die in der Grünkornmatrix gut löslich sind und die zwei oder mehr radikalisch polymerisierbare Gruppen tragen. Nach der Eindiffusion der Moderatoren werden diese polymerisiert. Das entstehende Netzwerk ist hochmolekular, unlöslich und mit der Pulvermatrix verhakt und somit diffusionsstabil.

2.) Man verwendet einen in der Grünkornmatrix unlöslichen Moderator, der zudem einen sehr geringem Dampfdruck bei Raumtemperatur aufweist. Dieser sitzt dann nach der Oberflächenbehandlung nur auf der Grünkornoberfläche und kann aus Affinitätsgründen praktisch nicht ins TLP-Korn eindiffundieren. Ein Moderatorverlust an der TLP-Oberfläche durch Verdampfen/Sublimation ist bei genügend hohem Molekulargewicht vernachlässigbar. Niedermolekulare, lösliche Moderatoren, die sich für die erfindungsmässigen Oberflächenbehandlungen von zwei- und mehrbasigen TLP eignen, weisen einen möglichst geringen Dampfdruck bei 21°C auf und sind entweder flüssig oder, wenn sie in der niederviskosen Flüssigkeit löslich sind, Feststoffe. Geeignete Stoffklassen umfassen Ether, Ester, Urethane, Harnstoffe und Ketone. Beispiele sind Campher, Dibutylphthalat, Diamylphthalat, Centralit, Dipropyladipat, Di(2-Ethylhexyl)adipat, Diphenylurethan, Methylphenylurethan, Hexandiol-diacrylat, Ethylenglykol-dimethacrylat, etc.

Alternatively, moderators can be used for the surface treatment according to the invention, which cannot diffuse appreciably in the TLP matrix. This can be done in two ways:

1.) Moderators are used which are readily soluble in the green grain matrix and which carry two or more radical-polymerizable groups. After the moderators are diffused in, they are polymerized. The resulting network is high molecular weight, insoluble and interlocked with the powder matrix and thus stable against diffusion.

2.) You use a moderator that is insoluble in the green grain matrix and also has a very low vapor pressure at room temperature. After the surface treatment, it only sits on the green grain surface and, for reasons of affinity, can practically not diffuse into the TLP grain. A moderator loss on the TLP surface due to evaporation / sublimation is negligible if the molecular weight is sufficiently high. Low-molecular, soluble moderators, which are suitable for the inventive surface treatments of two- and multi-base TLP, have the lowest possible vapor pressure at 21 ° C and are either liquid or, if they are soluble in the low-viscosity liquid, solids. Suitable classes of substances include ethers, esters, urethanes, ureas and ketones. Examples are camphor, dibutyl phthalate, diamyl phthalate, centralite, dipropyl adipate, di (2-ethylhexyl) adipate, diphenyl urethane, methyl phenyl urethane, hexanediol diacrylate, ethylene glycol dimethacrylate, etc.

Oligomeric, soluble moderators such as polyether and polyester are also suitable Molecular weights from 500 to 3000 daltons. Examples are poly (tetrahydrofuran), Polymethyl vinyl ether, poly (oxyethylene), polyethylene glycol, poly (butanediol) divinyl ether, polyester such as SANTICIZER 431, PARAPLEX G-54, or poly [di (ethylene glycol) adipate, polyethylene glycol, Polyethylene glycol acrylate, polyethylene glycol methacrylate, polyethylene glycol diacrylate, Polyethylene glycol dimethacrylate, polyethylene glycol dimethyl ether, poly (propylene glycol), Poly (propylene glycol) acrylate, poly (propylene glycol) diacrylate, poly (propylene glycol) ether, Polycaprolactone diol, polycaprolactone triol and those derived therefrom Co-oligomers. There are none for the acrylates / methacrylates Polymerization reactions carried out.

The moderators which can be crosslinked by free radicals comprise low molecular weight compounds or Oligomers or polymers containing at least two radicals per molecule carry polymerizable groups.

• niedermolekularen Verbindungen bzw. Oligomeren oder Polymeren, welche pro Molekül mindestens eine polymerisierbare Gruppe besitzen und
• Verbindungen, die mindestens zwei polymerisierbare Gruppen tragen.

The radically networkable moderators also include mixtures of

• low molecular weight compounds or oligomers or polymers which have at least one polymerizable group per molecule and
• Compounds that carry at least two polymerizable groups.

These compounds are either insoluble in the TLP matrix and thus remain on the TLP surface or they are soluble and therefore diffuse in the course of the invention Surface treatment in the top layer of the TLP. A suitable thermal activatable radical starter (initiator) must be added to the networkable moderator become. The initiator should be so soluble in the moderator that it is is distributed homogeneously in the moderator. The treatment conditions and the initiator must be chosen so that the initiator during the surface treatment process in the polishing drum, if possible, cannot disintegrate into radicals. Are initiator and polymerizable moderator either present as a layer on the TLP surface or diffused into the outermost TLP layer, so the atmospheric oxygen and sometimes the Indian Outermost TLP layer of oxygen removed by vacuum at room temperature and replaced by inert gas. This is necessary so that the radical reactions (Polymerization, crosslinking) without annoying side reactions and with high yield expire. Under inert gas, the temperature of the TLP is increased to such an extent that the initiator breaks down into radicals as quickly and completely as possible. These radicals then start the Polymerization or the networking of moderators.

Initiators which are practical at room temperature are preferably used as radical initiators not, but at temperatures around 60 ° C to 90 ° C very quickly in the corresponding Radicals decay. This guarantees a quick, gentle and complete implementation of polymerizable moderators. Examples of suitable radical initiators are tert. peroxyneodecanoate, Di (4-tert.butylcyclohexyl) peroxydicarbonate, tert. Butyl peroxypivalate, Dilauroyl peroxide, bis (aza-isobutyronitrile) etc.

The amount of the polymerization initiator used depends on the amount of deployed, networkable moderator. Between 0.1 and 5 mol% of initiator are obtained used on 1 mole of moderator. Initiator amounts between 1 and 4 mole%.

Derivatives of diacrylates, triacrylates, Tetraacrylates, dimethacrylates, trimethacrylates, tetramethacrylates, diacrylamides, Triacrylamides, dimethacrylamides, trimethacrylamides, divinyl esters, trivinyl esters, Divinyl ethers, trivinyl ethers, divinyl aromatics, trivinyl aromatics etc. are suitable.

Examples of low molecular weight, radically crosslinkable moderators are Hexanediol diacrylate, hexanediol dimethacrylate, ethylene glycol dimethacrylate, Tetraethylene glycol diacrylate, triethylene glycol diacrylate, dipropylene glycol diacrylate, Trimethylolpropane triacrylate, pentaerythritol tetraacrylate etc.

Examples of oligomeric, radically crosslinkable moderators are low molecular weight ones Polyethylene glycol diacrylate, low molecular weight polyethylene glycol dimethacrylate, ethoxylated bisphenol A diacrylate, propoxylated neopentyl glycol diacrylate, ethoxylated Neopentyl glycol diacrylate, propoxylated glycerol triacrylate, ethoxylated pentaerythritol tetraacrylate Etc.

Examples of polymeric, radically crosslinkable moderators are Polybutadiene diol diacrylate, high molecular weight polyethylene glycol diacrylate, high molecular weight Polyethylene glycol dimethacrylate, high molecular polypropylene oxide diacrylate etc.

The moderators who are not very soluble or completely insoluble in the TLP are solid or liquid compounds that are soluble in the low-viscosity liquid or at least are finely emulsifiable. The connections in question can be act inert or energetic substances. It must be assumed that the Moderator concentration on the TLP surface not by sublimation or diffusion can change. This can be done by using either high melting, low molecular weight or of oligomeric or polymeric compounds. moreover the volatility in the case of insoluble compounds which have polymerizable groups, after application to the TLP grain additionally by a polymerization reaction (as described above).

Apolar polymers and oligomers or strongly polar are suitable as insoluble moderators Polymers and oligomers with or without polymerizable groups.

Examples include totally or partially hydrolyzed polyvinyl acetate, poly (vinyl alcohol-coethylene), Polybutadiene, polybutadiene diol, polybutadiene diol diacrylate, polystyrene, Polyvinylpyrrolidone, poly (acrylonitrile-co-butadiene), poly (α-methylstyrene), poly (vinyltoluene-co-α-methylstyrene), Etc.

To the low-viscosity liquid:

In the case of the low-viscosity liquid which is needed, the surface treatments according to the invention it is a solvent or solvent mixture, the solid or liquid cone-stabilizing moderator very well dissolve or can be finely emulsified, but the TLP grain cannot or only very little is able to swell. Liquids with high or low polarity are well suited. The boiling point of the liquid must be higher than the surface treatment temperature. Nevertheless, the low-viscosity liquid should have a sufficiently high volatility that evaporation at the treatment temperature can take place in a short time (between 5 and 60 minutes). If necessary, the liquid can also with the help of Pressure reduction or be removed using a warm gas stream. The liquid can be pure Solvent or a mixed solvent can be used. For surface treatment amounts of 0.1% to 5% liquid (based on the amount of TLP) used. Between 0.5% and 2% liquid is preferably used.

Examples of particularly suitable low-viscosity liquids are water and mixtures from water and methanol, mixtures from water and ethanol, mixtures from water and Propanol, mixtures of water and acetone, mixtures of water and tetrahydrofuran, as well as pentane, hexane, heptane, cyclohexane, toluene, methylene chloride and mixtures thereof.

Perforated TLP are treated with the substances mentioned above in a polishing drum. The volume of an arbitrarily large polishing drum made of steel or copper, whereby the Minimum volume is limited to about 10 liters, this is partially done with a perforated TLP filled. The desired degree of filling is between 5 and 50%, preferably between 10 and 40%. The TLP can be ungraphited or graphitized. This is done by turning first the solid or the solid mixture is applied and homogeneous to the whole Distributed TLP surface. If the TLP used is already sufficiently graphitized, it can if necessary, a further introduction of solid material can be dispensed with or it can another solid is added. Then a solution from the low-viscosity Liquid and the moderator or the moderator mixture added. in the If a crosslinking of polymerizable moderators is desired, this contains Solution also the polymerization initiator.

Because of safety considerations (electrostatic charges during transport from TLP) the powder must always be covered with an electrically conductive material at least one of the solid components should be either graphite dust or Be acetylene black.

If the solid consists of inert (non-energetic) material, it is only in small amounts (based on the TLP). So in the polishing drum between 0.01% and 2% solids homogeneously distributed on the TLP. In the case of an admixture of energetic material can because of the better ignitability of this mixture Concentration of more than 2% can be used.

With optimal flow movements of the TLP grains and at temperatures between 0 ° C and 90 ° C, preferably between 20 ° C and 70 ° C is left for a certain time the added substances act on the TLP surface. The exposure process lasts between 5 minutes and 4 hours, preferably between 15 minutes and 120 minutes. The polishing drum must (depending on the steam pressure of the used Liquid) must be gas-tight.

After the exposure time, in the case of a gas-tight treatment facility, the Removed the lid of the filling hole so that most of the low-viscosity liquid can evaporate. This evaporation process must also be precisely controlled in time. The time period can be between 5 minutes and 4 hours, preferably between Evaporated for 10 minutes and 120 minutes. The evaporation can by other Measures are additionally supported or promoted. For example, an air or Inert gas flow can be passed over the moist TLP.

In the case of non-polymerizing moderators, the treated TLP then becomes subjected to a sharp drying process. This leaves the last traces of solvents removed and the treatment layer stabilized. This is how the TLP is typically Leave at 60 ° C for about 3 days in a convection oven. This allows e.g. ethanol Remove completely (<0.01%).

If a radically polymerizable moderator is used and one If the polymerization reaction is to be carried out, a corresponding one is also used Polymerization initiator added. The surface treatment of the TLP is as possible carried out at a lower temperature and the low-viscosity liquid at the same temperature away. The surface treatment is preferably carried out at room temperature. The TLP is then vacuumed of solvent residues and atmospheric oxygen freed and placed under inert gas. Alternatively, the TLP can only be used with the inert gas purged to displace atmospheric oxygen. As an inert gas e.g. argon or nitrogen can be used. Only then is the TLP mass applied to the under inert gas required polymerization temperature, which is usually around 30 ° C to 60 ° C above the treatment temperature.

E.g. treated at room temperature, a polymerization initiator is used, which is thermally stable at room temperature, but very quickly in at 50 ° C to 80 ° C the corresponding radicals disintegrate.

The decay half-life of a polymerization initiator is the time in which half of the Initiator has broken down into radicals at a certain temperature. This decay half-life is, because of its central importance, in all commercially available thermal Initiators known. So that the polymerization reactions are as complete as possible the polymerization time at a certain temperature to four to six times the decay half-life of the initiator used Temperature set. Then the TLP is opened directly in the air or under the inert gas Cooled to room temperature. Because preferred for applying the polymerizable moderator low-boiling, apolar solvents are used, the TLP is after Evacuation and polymerization practically solvent-free.

The surface treatment processes shown above cause the perforated channels in the entrance area with compact, compacted cones, consisting mainly of the used solids or solid mixtures and from moderator, closed become.

The low-viscosity liquid and / or the moderator soluble in the TLP causes this (Desensitizer) that the pin is additionally solidified and anchored in the perforated channel.

Surprisingly, it was found that with the right choice of treatment parameters all surface-treated, perforated TLP have a greatly reduced temperature dependency or even a largely temperature-independent characteristic when burning exhibit. It was observed that when firing at high powder temperatures the pegs are anchored in a practically stable manner in the perforated channels and remain in place. Thereby is in the first burning phase the burning process of the TLP due to the changed shape function unlike classic behavior and the inherently fast powder burn-off at high temperatures there is therefore a lot of compensation. Will the same TLP at room temperature fired, the shape function changes in the sense that a faster Surface enlargement takes place and thus the gas formation rate to that at high Operating temperatures can be adjusted. Finally one observed at very low TLP temperatures that the gas formation rate due to reaching a classic Behavior in terms of shape function in perforated TLP is that of a green grain equalizes.

The burn in the perforations of the TLP is therefore due to the treatment-related influence slows down to the shape function with increasing powder temperatures. This works the with increasing temperature, the burning speed of the TLP becomes faster. Ideally, the two effects compensate, so that the surface-treated TLP has a temperature-independent burning behavior.

This mechanism of action according to the invention thus differs completely from that other mechanisms described in the literature for achieving a reduced Temperature dependence. In particular, this mechanism is not based on the (dangerous) Embrittlement of the TLP at low temperatures.

With the right choice of surface treatment components, this effect remains obtained when the treated TLP undergoes accelerated aging (e.g. 4 weeks storage at 63 ° C) or stored at room temperature for a very long time. Thus points the surface-treated TLP has good ballistic stability, i.e. the one with this Ammunition filled with propellant powder can be fired safely and with constant performance become.

It was also found that the surface treatment according to the invention is different also has a favorable effect on the flowability and bulk density of the TLP. That's how they are Bulk densities of the treated TLP are up to 10% higher than the bulk densities of the untreated TLP.

Since the shell volume of a given ammunition component is specified, in case of increased bulk density, place more powder in this given tube volume.

TU behavior (temperature-independent combustion characteristics) and high bulk density now that existing tubes can be filled with more TLP and thus the kinetic energy of the projectile can be increased without doing so throughout Temperature range of the given maximum pressure in the weapon exceeded becomes.

A TLP that is subjected to a surface treatment according to the invention is therefore suitable was, significant and inexpensive combat value increases in existing weapon systems to realize without impairing the full system compatibility. in the This treated TLP can also be used in newly developed weapon systems become. It can z. B. improves the ignition and / or pipe erosion can be reduced.

1.) Einarbeitung eines nichtflüchtigen Feststoffs in die Perforationen eines zwei- oder mehrbasigen Treibladungskorns in geeigneten Behandlungsvorrichtungen. Verwendet werden dazu Feststoffe mit einer mittleren Korngrösse, die deutlich kleiner ist als der Perforationsdurchmesser, geeignete Moderatoren zur Zapfenstabilisation und eine adäquate Menge einer leicht zu entfernenden, niederviskosen Flüssigkeit.

2.) Die gebildeten Behandlungsschichten aus Feststoff werden in den Perforationen mit Hilfe des Moderators und der niederviskosen Flüssigkeit dermassen verdichtet bzw. verankert, dass mit steigender Einsatztemperatur die Verschliessung resistenter wird gegen den Anzündschock und damit die Formfunktion entsprechend beeinflusst wird. Diese Eigenschaft der Zapfen bleibt unverändert über die ganze Produktelebensdauer des Treibladungspulvers (ballistische Stabilität).

3.) Art und Konzentration des Feststoffs, des Moderators und der niederviskosen Flüssigkeit werden zusammen mit den Oberflächenbehandlungsparametern (Masse, Temperatur, Drehzahl, Behandlungsdauer, etc.) auf jedes Pulverkorn und die entsprechende Anzündung angepasst, um das optimale Ergebnis zu erhalten.

4.) Durch stärkere Oberflächenbehandlung (Erhöhung der Konzentration des Feststoffs und/oder des Moderators und/oder der Behandlungsdauer) kann die normale Temperaturabhängigkeit des TLP-Abbrands sogar invertiert werden: Dermassen stark behandelte TLP brennen bei tiefen Temperaturen schneller ab als bei hohen Temperaturen ("negativer Temperaturkoeffizient").

5.) Durch Abmischen von stark behandeltem TLP (mit invertiertem Abbrandverhalten) mit unbehandeltem TLP lassen sich ebenfalls TLP herstellen, deren Abbrand unabhängig von der Temperatur ist. Generell kann durch Abmischen von behandeltem mit unbehandeltem TLP die Brisanz in einem weiten Bereich variiert werden.

The essence of the invention can be summarized as follows:

1.) Incorporation of a non-volatile solid in the perforations of a two- or multi-base propellant grain in suitable treatment devices. Solids with an average grain size, which is significantly smaller than the perforation diameter, suitable moderators for cone stabilization and an adequate amount of an easy-to-remove, low-viscosity liquid are used for this.

2.) The treatment layers formed from solid are compacted or anchored in the perforations with the help of the moderator and the low-viscosity liquid so that the sealing becomes more resistant to the ignition shock and thus the shape function is correspondingly influenced with increasing operating temperature. This property of the cones remains unchanged over the entire product life of the propellant powder (ballistic stability).

3.) The type and concentration of the solid, the moderator and the low-viscosity liquid are adjusted together with the surface treatment parameters (mass, temperature, speed, duration of treatment, etc.) to each powder grain and the corresponding ignition in order to obtain the optimal result.

4.) With stronger surface treatment (increasing the concentration of the solid and / or the moderator and / or the duration of the treatment), the normal temperature dependence of the TLP burn-off can even be inverted: TLPs that have been treated in this way burn more quickly at low temperatures than at high temperatures ( "negative temperature coefficient").

5.) By mixing heavily treated TLP (with inverted burning behavior) with untreated TLP, TLP can also be produced, the burning of which is independent of the temperature. In general, the explosiveness can be varied within a wide range by mixing treated with untreated TLP.

By checking the parameters described in points 1) to 3), it is possible to Novel propellant bulk powder with greatly reduced to neutral temperature sensitivity to produce (pure treated TLP).

• Die Treibladungspulver-Rohmasse wurde aus 58 % Nitrocellulose, 26 % Nitroglycerin und 16 % Diethylenglycoldinitrat gefertigt. Als Stabilisator wurde Akardit II verwendet.
• Das perforierte Grünkorn wurde in einer Strangenpresse mit einer 19-Loch Matrize hergestellt. Die Matrizendimension ist bei den Beispielen jeweils angegeben.
• Das oberflächenbehandelte Grünkorn mit einem praktisch temperaturunabhängigen Abbrandverhalten wird auch als SCDB (Surface Coated Double Base) Treibladungskorn bezeichnet.

The following should be said about the examples described below:

• The propellant powder raw material was made from 58% nitrocellulose, 26% nitroglycerin and 16% diethylene glycol dinitrate. Akardit II was used as a stabilizer.
• The perforated green grain was produced in an extrusion press with a 19-hole matrix. The matrix dimension is given in the examples.
• The surface-treated green grain with a practically temperature-independent burn-off behavior is also referred to as SCDB (Surface Coated Double Base) propellant grain.

Example 1 (FM 2032n / 9)

In a treatment facility (treatment drum) 90 kilograms of green grain, made with a 10.5x (19x0.2) mm die, presented at 16 ° C. Add 180 Grams of graphite (0.2% by weight based on the TLP) and a solution of 1440 milliliters 80% vol ethanol (16 ml per kg TLP) and 225 grams polytetrahydrofuran 650 (0.25% by weight based on the TLP).

When the drum is closed gastight, the mixture is at 16 ° C and 14 U / Min. 30 minutes long stirred. Then the lid of the polishing drum is removed and the solvent evaporated for 105 minutes.

The treated TLP is dried at 60 ° C for 3 days.

1a-c shows a comparison of the test results of the combustion behavior of a propellant powder in the ballistic bomb. The ratio is on the abscissa of the current pressure P to the maximum pressure Pmax and on the ordinate is the dynamic one Liveness (1 / bar sec) x100 applied. In Fig. 1a is the behavior of the untreated Grünkorns can be seen at application temperatures of -40 ° C, + 21 ° C and + 50 ° C. In Fig. 1b the pressure bomb tests are immediately after the powder production and in Fig. 1c recorded after 5 years of storage at 21 ° C.

In comparison with the green grain, the surface-treated (SCDB) TLP FM 2032n / 9 shows in the 150 ml pressure bomb (loading density 0.2, shelling at -40 ° C, + 21 ° C and + 50 ° C) the three powder temperatures very small liveliness differences. That means that Burning is practically independent of temperature.

Part of the treated TLP is 5 in a closed vessel at room temperature Stored for years. A pressure bomb is shot again from this stored TLP (Fig. 1c). The TLP shows practically the same dynamic vivacity as 5 years previously, i.e. the burn-off is still temperature-independent.

Example 2 (FM 2712n)

220 kilograms of green grain are produced in a large treatment facility a 12.0x (19x0.20) mm die and warmed up to 30 ° C, presented. In addition there are 187 Grams (0.085% by weight based on the TLP) of graphite and then a solution 264 grams of polytetrahydrofuran 650 (0.12% by weight based on TLP) and 2040 grams of 75% vol Ethanol (10.6 milliliters per kilogram of TLP). Leave at 30 ° C with the drum closed for 60 minutes at a speed of 8.25 rpm. stir. After that the lid of the polishing drum is removed, again 187 grams (0.085% by weight) of graphite added and the solvent was evaporated while rotating for 30 minutes.

The TLP treated in this way is dried at 60 ° C. for 3 days.

Example 3 (FM 2758n)

This treatment is carried out exactly the same as in Example 2.

In order to confirm the mechanism of temperature-independent burning of the TLP, Powder grains in an extinguishing bomb examined at different temperatures: A rupture disc opened the bomb at approx. 700 bar and the burnt-in TLP grains were thrown into a water bath and extinguished. The recuperated, partially burned TLP were photographed.

2a-c show the burnt-in TLP grains, which are at -40 ° C., + 21 ° C. and + 50 ° C. were shot. It can be clearly seen that at low temperatures other shape functional properties contribute to the burning mechanism than at high temperatures.

3a again shows the pressure bomb results of the untreated green grain FM2708n. 3b and 3c show the test results of the two samples FM 2712n and FM 2758n. It is clearly evident that the temperature dependence of the TLP burnup could be greatly reduced.

A weapon bombardment has also been carried out with these patterns. As from Fig. 4b (Peak gas pressure depending on the temperature) can be seen via the whole temperature range from -40 ° C to + 63 ° C no big variations in the pressure course be determined. The measured muzzle velocities also only vary very light (Fig. 4a: muzzle velocity depending on the temperature). in the In contrast, the untreated TLP LKE II shoots very temperature-dependent.

Example 4 (CM 0310n / 112)

8 kilograms of green grain are produced in a treatment facility at room temperature with the die 12.0x (19x0.20) mm. Add 32 grams (0.40 % By weight based on the TLP) graphite (grain size 45 microns) and distributes it homogeneously on the entire bulk powder surface by turning at 24 rpm. during 5 minutes in the closed drum.

A solution consisting of 100 is then sprayed while rotating the powder mass Grams of cyclohexane (1.25% by weight based on the TLP), 40 grams of propoxylated Glycerol triacrylate (0.5% by weight based on the TLP) and 2 grams of di (4-tert-butylcyclohexyl) peroxydicarbonate (5% by weight based on the triacrylate).

If the drum is closed gas-tight, the mass is at room temperature for 60 minutes touched. Then the lid of the treatment device is removed and the solvent evaporated while rotating for 30 minutes.

The treated TLP is transferred to a vacuum cabinet and there at room temperature evacuated until a final pressure of about 1 mbar is reached. Then the vacuum cabinet filled with nitrogen and the heating switched on. Once the TLP reaches a temperature of 70 ° C, this temperature is left to act for about two hours. The TLP is then allowed to cool to room temperature.

HPLC studies of the treated TLP showed that there was no free triacrylate in the TLP there was more.

1 kg of the treated TLP is sealed in a gas-tight bag and attached to Stored at 71 ° C for 4 weeks. This corresponds to storage at room temperature of several decades (50 to 100 years). The rest of the TLP is stored at room temperature.

From the artificially aged sample, from the normally stored sample and from untreated TLP is shot a 150 ml pressure bomb (loading density 0.2) at -40 ° C, + 21 ° C and + 50 ° C.

The results are shown in Figures 5a-c. The dynamic vivacity of the treated TLP (Fig. 5b) at the different bombardment temperatures do not differ more as strong as those of the green grain (Fig. 5a). The TLP treated is less become temperature sensitive. The dynamic animations have changed through artificial aging did not change (Fig. 5c) because of diffusion of the polymerized moderator is no longer possible. On the one hand, this is due to the greatly increased molecular weight of the moderator through the networking and additionally through the hooking of the polymeric moderator chains with the nitrocellulose chains. That means the treated TLP is ballistically stable.

Studies of the concentration profile using FTIR confirm that the networked moderator can no longer diffuse. This is in Fig. 6 (relative concentration in function the depth of penetration). The moderator's concentration gradients are there Surface of the TLP grains unchanged before and after artificial aging.

Example 5 (FM 2706n / F)

Analogously to example 4, a green grain was made with the matrix 11.0x (19x0.20) mm, treated with a networkable moderator.

Ethylene glycol dimethacrylate (1.3% by weight or TLP) was used.

After the moderator was crosslinked, the residual ethylene glycol dimethacrylate content was reduced determined by GC / MS. It was found that> 95% of the dimethacrylate was converted. The TLP was stored at 71 ° C for 4 weeks and then with FTIR microspectroscopy its concentration profile compared to normally stored TLP. In the Fig. 7 concentration profiles of the networked moderator show that even under drastic storage conditions no diffusion can be determined. That means again that this TLP is ballistically stable.

Example 6 (AM 0116n / 202)

In a small rotary drum, 8 kilograms of green grain are mixed with a 12x (19x0.20) mm die was produced, submitted. The green grain was previously on Heated to 60 ° C.

Add to the warm green grain by turning at 26 rpm. 12 grams of graphite (0.12 % By weight based on the TLP). As soon as the graphite is homogeneously distributed on the TLP a solution of 90 grams of water (1.1% by weight based on the TLP) and 5.6 grams Polyvinyl alcohol (0.07% by weight based on the TLP) was added and with the Drum mixed at 60 ° C for 70 minutes.

Then the cap is removed and the water is rotated for 20 minutes evaporated.

The treated TLP is dried at 60 ° C for three days.

In Fig. 8a-c are the pressure bombs at different powder temperatures of the Grünkorns (Fig. 8a: untreated), the treated powder (Fig. 8b: after storage at 21 ° C for 4 weeks) and the accelerated aged, treated powder (Fig. 8c: 4 weeks at 63 ° C). The pressure bomb clearly shows the reduction in temperature dependence of powder burn-off after the surface treatment according to the invention. This reduction remains unchanged when the treated TLP undergoes artificial aging is subjected. Because of its insolubility, polyvinyl alcohol cannot enter the TLP matrix diffuse. This treated TLP is also ballistically stable.

Example 7 (AM 0106n / 1)

In a medium surface treatment device thermostatted to 30 ° C 55 kilograms of green grain, made with a 13.7x (19x0.26) mm rosette matrix was submitted. The green grain was previously heated to 30 ° C.

Add to the warm green grain by turning at 13.6 rpm. 55 grams of graphite (0.10% by weight based on the TLP). As soon as the graphite is homogeneously distributed on the TLP, is a solution of 512 grams of ethanol (75% vol. ethanol, 25% vol. water) and 27.5 Gram polytetrahydrofuran 650 (0.05% by weight based on the TLP) added and at closed drum mixed at 30 ° C for 60 minutes.

The cap is then removed and the aqueous ethanol is turned while rotating Evaporated for 15 minutes.

The treated TLP is dried at 60 ° C for three days.

In Fig. 9a-d the pressure bombing at different powder temperatures of the Grünkorns (Fig. 9a: untreated), the treated powder (Fig. 9b: after storage at 21 ° C for 4 weeks) and the accelerated aged, treated powder (Fig. 9c: 4 weeks at 63 ° C). The pressure bomb clearly shows the reduction in temperature dependence of powder burn-off after the surface treatment according to the invention. This reduction remains unchanged when the treated TLP undergoes artificial aging is subjected. This treated TLP is also ballistically stable.

9d is a mixture of 70% by weight of green grain and 30% by weight of treated Grain shown. With such mixtures, the liveliness of the TLP burnup can still can also be controlled.

Example 8 (AM 0116n / 308)

8 kilograms of green grain are produced in a treatment facility at room temperature with the die 12.0x (19x0.20) mm. Add 16 grams (0.20% by weight based on the TLP) graphite (grain size 45 microns) and distributes it homogeneously on the entire bulk powder surface by turning at 24 rpm. during 5th Minutes in the closed drum.

Then spray a solution consisting of 60 grams while rotating the powder mass Cyclohexane (0.75% by weight based on the TLP) and 12 grams Polybutadiene diol dimethacrylate (0.15% by weight based on the TLP) on the graphitized TLP.

If the drum is closed gastight, the mass at room temperature will be 100 minutes long stirred. Then the lid of the treatment device is removed and the solvent evaporated while rotating for 20 minutes.

The treated TLP is then dried at 60 ° C for 3 days.

Part of this surface-treated TLP is at 71 ° C for 4 weeks in one gas-tight bag artificially aged (Fig. 10b), during which the other part of the TLP is gas-tight is stored at room temperature (Fig. 10a).

Both TLPs are bombarded in the 150 cm ³ pressure bomb at - 40 ° C, + 21 ° C and + 63 ° C. The results are shown in Fig. 10. Although the moderator is not networked on the TLP, there is no change in vivacity in the pressure bomb before (Fig. 10a) and after (Fig. 10b) aging. This means that the moderator is neither diffused nor diffused into the TLP.

Examination of the concentration profiles using FTIR microspectroscopy before and after the aging of the TLP also shows no changes.

• Die vorliegende Erfindung erbrachte die neue Erkenntnis, dass die Senkung des Temperaturkoeffizienten von perforierten, zwei- bis mehrbasigen TLP durch gezielte Versiegelung der Perforationen mit Zapfen erreicht wird, welche eine temperaturabhängige Mobilität haben. Durch geeignete Oberflächenbehandlungsprozesse können die Löcher des TLP dermassen verschlossen werden, dass der Lochbrand bei hohen TLP-Temperaturen verzögert, bei tiefen Temperaturen sofort abläuft (Einfluss auf die Formfunktion). Dies führt zu einem Abbrandverhalten des oberflächenbeschichteten zweibasigen TLP, welches weitgehend unabhängig von der Temperatur des TLP ist.
• Überraschenderweise wurde gefunden, dass bei einer optimalen Wahl der Behandlungs-Komponenten und -Parameter mit Kleinstmengen an Behandlungsmitteln ein temperaturunabhängiger Abbrand des artreinen, behandelten TLP erzielt werden kann. Das hat den grossen Vorteil, dass sich das behandelte Treibladungskorn sehr leicht durch die Initialzündung anzünden lässt. Zudem lässt sich die erfindungsgemässe Oberflächenbehandlung dermassen reproduzieren, dass das behandelte TLP artrein (und nicht unbedingt als Gemisch) eingesetzt werden kann. Somit ist ein homogener Abbrand erreichbar.
• Überraschenderweise wurde zudem gefunden, dass die erfindungsgemässe Oberflächenbehandlung die Herstellung ballistisch stabiler TLP erlaubt. Somit ist über die gesamte Einsatzdauer des Munitionssystems ein gleichbleibendes Abbrandverhalten gewährleistet.
• Diese neuartigen Oberflächenbehandlungen können im Prinzip auf jedes perforierte Grünkorn angewendet werden, sind aber der jeweiligen Rezeptur und Matrix des TLP als auch dem Anzündsystem anzupassen, um die Temperaturabhängigkeit des TLP-Abbrands möglichst optimal einstellen zu können.
• Die gefundene Oberflächenbehandlungstechnik erlaubt es, TLP herzustellen, die innerhalb eines breiten Temperaturintervalls ähnlich grosse Gasbildungsraten und somit ähnliche Mündungsgeschwindigkeiten und Spitzengasdrücke aufweisen. Dies hat zur Folge, dass unabhängig von der Umgebungstemperatur, bei welcher die Munition verschossen wird, ein konstant hohes Energieniveau zur Verfügung steht und somit die endballistische Leistung konstant und hoch gehalten werden kann.
• Mit der erfindungsgemässen Oberflächenbehandlung kann das Temperaturverhalten des TLP in weiten Bereichen variiert oder ein gewünschtes Verhalten gezielt eingestellt werden. Wird die Oberflächenbehandlung in abgeschwächter Form durchgeführt (kleinere Mengen an Feststoff und/oder Moderator (Phlegmatisator) und/oder kürzere Behandlungszeiten als bei der optimalen Behandlung), so wird eine reduzierte Temperaturunabhängigkeit des TLP-Abbrandes erzielt. Bei einer optimalen Behandlung ist der TLP-Abbrand jedoch annähernd temperaturunabhängig. Wird eine starke Oberflächenbehandlung durchgeführt (grössere Mengen an Feststoff und/oder Moderator (Phlegmatisator) und/oder längere Behandlungszeiten als bei der optimalen Behandlung), so kann das Temperaturverhalten des TLP invertiert werden: Bei hohen Temperaturen ist in diesem Fall die Gasbildungsrate des behandelten TLP geringer als bei tiefen Temperaturen.
• Somit kann durch das Abmischen von stark behandeltem und nicht behandeltem TLP im richtigen Verhältnis ebenfalls ein TLP mit temperaturunabhängigem Abbrandverhalten hergestellt werden.
• Das behandelte Schüttpulver weist eine verbesserte Rieselfähigkeit und eine erhöhte Schüttdichte auf. Die Schüttdichte ist ein Mass dafür, welches Gewicht an Treibladungspulver in einer Volumeneinheit untergebracht werden kann und wird typischerweise in der Einheit Gramm pro Liter (g/l) angegeben. Diese erhöhte Schüttdichte ist von grosser Bedeutung, da das Hülsenvolumen einer gegebenen Munitionskomponente vorgegeben ist. Je mehr Pulvermenge sich in diesem vorgegebenen Hülsenvolumen unterbringen lässt, desto mehr chemische Energie steht schliesslich für die ballistische Anwendung zur Verfügung.
• Da für die neuartige Oberflächenbehandlung nur sehr kleine Mengen an energetisch inertem Material eingesetzt werden, fällt der Leistungsabfall des behandelten TLP kaum ins Gewicht (gemäss Verbrennungskalorimetrie besitzt das behandelte TLP im Vergleich zum Grünkorn lediglich eine um ca. 2% geringere Explosionswärme).

In summary, the following should be noted:

• The present invention brought about the new finding that the lowering of the temperature coefficient of perforated, two- to multi-base TLP is achieved by targeted sealing of the perforations with cones, which have a temperature-dependent mobility. By means of suitable surface treatment processes, the holes in the TLP can be closed in such a way that the hole fire is delayed at high TLP temperatures and takes place immediately at low temperatures (influence on the shape function). This leads to a burning behavior of the surface-coated two-base TLP, which is largely independent of the temperature of the TLP.
• Surprisingly, it was found that with an optimal choice of treatment components and parameters with small amounts of treatment agents, a temperature-independent burn-off of the pure, treated TLP can be achieved. This has the great advantage that the treated propellant grain can be ignited very easily by the initial ignition. In addition, the surface treatment according to the invention can be reproduced to such an extent that the treated TLP can be used in pure form (and not necessarily as a mixture). This enables homogeneous burn-up.
• Surprisingly, it was also found that the surface treatment according to the invention allows the production of ballistically stable TLP. This ensures constant combustion behavior over the entire period of use of the ammunition system.
• In principle, these new types of surface treatments can be applied to any perforated green grain, but they must be adapted to the respective recipe and matrix of the TLP and the ignition system in order to be able to optimally adjust the temperature dependence of the TLP burnup.
• The surface treatment technology found makes it possible to produce TLPs that have similarly large gas formation rates and thus similar muzzle velocities and peak gas pressures within a wide temperature range. The consequence of this is that regardless of the ambient temperature at which the ammunition is fired, a constantly high energy level is available and the final ballistic performance can thus be kept constant and high.
• With the surface treatment according to the invention, the temperature behavior of the TLP can be varied within wide ranges or a desired behavior can be set in a targeted manner. If the surface treatment is carried out in a weakened form (smaller amounts of solid and / or moderator (desensitizer) and / or shorter treatment times than in the case of the optimal treatment), a reduced temperature independence of the TLP burnup is achieved. With optimal treatment, however, the TLP burnup is almost independent of temperature. If a strong surface treatment is carried out (larger amounts of solid and / or moderator (desensitizer) and / or longer treatment times than with the optimal treatment), the temperature behavior of the TLP can be inverted: In this case, the gas formation rate of the treated TLP is high at high temperatures less than at low temperatures.
• Thus, by mixing heavily treated and untreated TLP in the correct ratio, a TLP with temperature-independent combustion behavior can also be produced.
• The treated bulk powder has an improved flowability and an increased bulk density. The bulk density is a measure of which weight of propellant powder can be accommodated in a volume unit and is typically given in the unit gram per liter (g / l). This increased bulk density is of great importance since the shell volume of a given ammunition component is predetermined. The more amount of powder that can be accommodated in this given sleeve volume, the more chemical energy is ultimately available for ballistic use.
• Since only very small amounts of energetically inert material are used for the novel surface treatment, the drop in performance of the treated TLP is negligible (according to combustion calorimetry, the treated TLP has only about 2% less heat of explosion than the green grain).

The good service life is particularly noteworthy. Storage for long periods or at high temperatures is possible without the burn-off characteristics essential to influence.

In contrast to the prior art, the surface treatment process according to the invention a tendency to brittle fracture or the development of cross-burners low temperatures are not favored.

By using minimal amounts of treatment agent, that the burn in the pressure bomb or in the weapon is made independent of temperature can be without the ignition behavior is deteriorated.

The treatment process is simple, reproducible and relatively inexpensive.

Claims (22)

Propellant powder, the grain of which has at least one cavity opening with an opening to an outer surface of the grain, the opening being closed with a peg, characterized in that the peg has a temperature-dependent mobility which is such that greater mobility is given at a lower application temperature than at a higher application temperature, so that the peg allows more hole burnout at a lower application temperature than at a higher application temperature. Propellant powder according to claim 1, characterized in that the pin consists of a substance which is not soluble in a green grain on which the treated grain is based. Propellant powder according to claim 1 or 2, characterized in that the pin essentially consists of an inert solid, in particular with a grain size in the range from 0.01 to 100 micrometers, particularly preferably in the range from 0.1 to 50 micrometers. Propellant powder according to one of claims 1 to 3, characterized in that the inert solid consists essentially of graphite, talc, titanium oxide, carbon black, potassium sulfate, potassium cryolite, tungsten trioxide and / or calcium carbonate. Propellant powder according to one of claims 1 to 3, characterized in that the pin has a small proportion of energetic solid, in particular nitrocellulose, hexogen, etc. Propellant powder according to one of claims 1 to 4, characterized in that the pin has a melting temperature which is above a manufacturing, storage and / or application temperature, in particular above 90 ° C. Propellant powder according to one of claims 1 to 6, characterized in that the grain has several, in particular 7 to 19, axially through holes and that the cavity of a hole closed by the pin has a cavity volume which is a multiple of the volume of a pin. Propellant powder according to claim 6, characterized in that the grain is cylindrical and has a diameter of in particular 1 to 20 mm, particularly preferably from 3 to 15 mm and that the holes have a diameter of 0.03 to 0.5 mm, in particular 0.1 to Have 0.3 mm. Propellant powder according to one of claims 1 to 7, characterized in that the grain is two or more bases. Method for producing a propellant charge powder, wherein a grain is produced with at least one cavity opening with an opening to an outer surface of the grain, characterized in that a solid in the form of a cone is introduced into the opening in such a way that the cone has a temperature-dependent mobility, which is such that there is greater mobility at a lower application temperature than at a higher application temperature, so that the peg permits faster hole erosion at a lower application temperature than at a higher application temperature. A method according to claim 9, characterized in that the solid is introduced into the opening, compressed and anchored with the aid of a moderator, or a moderator insoluble in the grain, and a volatile liquid. A method according to claim 9 or 10, characterized in that the spigot by processing the solid, the moderator and the liquid in a mixing apparatus at a temperature in the range from 0 ° C to 90 ° C for a treatment period between 10 minutes and 3 hours and with a rotational speed of the mixing apparatus between 2 and 30 revolutions per minute is created. Method according to one of claims 9 to 11, characterized in that the moderator is radically crosslinkable with the help of a radical generator and that the solid is thereby compressed and anchored. Method according to one of claims 11 to 12, characterized in that the solid and / or the moderator is used in an amount of 0.001% by weight to 4% by weight, based on the weight of the untreated green grain, in the mixing apparatus. Method according to one of Claims 11 to 13, characterized in that the low-viscosity liquid is used in the mixing apparatus in an amount of 0.1% by weight to 5% by weight, based on the weight of the untreated grain. Method according to one of claims 12 to 14, characterized in that a radical generator is used in an amount of 0.1 mol% to 5 mol% based on the molar amount of the crosslinkable moderator, the radical generator having a high stability to disintegration at a surface treatment temperature, in particular a disintegration time for half of the radical generator of more than 10 hours, on the other hand rapidly decomposing into radicals at the polymerization temperature, in particular a disintegration time for half of the radical generator of less than 1 hour. Method according to one of claims 12 to 15, characterized in that the propellant powder is freed from atmospheric oxygen by means of flushing with inert gas or by means of vacuum / flushing with inert gas at room temperature after it has been treated with the crosslinkable moderator and with an initiator. Method according to one of claims 12 to 17, characterized in that the crosslinking of the moderator is carried out under inert gas at normal pressure, at a temperature of less than 90 ° C and for a period of less than six times the decay half-life of the radical generator at this temperature. Method according to one of claims 11 to 18, characterized in that as a solid graphite, talc, titanium oxide, carbon black, potassium sulfate, potassium cryolite, calcium carbonate, tungsten trioxide, as a moderator in particular polytetrahydrofuran, polyvinyl alcohol, poly (vinyl alcohol-co-vinyl acetate), poly (vinyl alcohol -co-ethylene), polybutadiene diol, polybutadiene diol dimethacrylate, poly (α-methylstyrene), polybutadiene or polybutadiene diol diacrylate is used. Method according to one of claims 11 to 19, characterized in that water, ethanol, hexane, cyclohexane or a mixture of water / ethanol, water / methanol or water / acetone is used as the liquid. A method as claimed in any one of claims 11 to 20, that A diacrylate as crosslinkable moderators hexanediol diacrylate, dipropylene glycol diacrylate, ethylene glycol dimethacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, triethylene glycol diacrylate, propoxylated glycerol triacrylate, pentaerythritol tetraacrylate, ethoxylated bisphenol diacrylate, neopentyl glycol-propoxylated, ethoxylated neopentyl glycol diacrylate , Polyethylene glycol diacrylate, polybutadiene diol diacrylate, polybutadiene diol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene oxide diacrylate. Method according to one of claims 11 to 21, characterized in that the liquid is removed by rotary evaporation from the open mixing apparatus and that the propellant charge powder is then stored at 60 ° C for 3 days.

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