EP3872054A1 - Binding agent for an explosive - Google Patents

Abstract

The invention relates to a binder for an explosive, comprising at least one ionic liquid and a polymer, the polymer being formed from monomers or molecules of a further polymer crosslinked by means of a crosslinking agent to form an elastic network, the ionic liquid being incorporated in the network.

Description

The invention relates to a binder for an explosive, comprising at least one ionic liquid and a polymer. More than one ionic liquid can be present in a mixture of ionic liquids.

From the EP 2 698 361 B1 the use of a composition comprising a polar polymer and an ionic liquid or a mixture of ionic liquids as a means for phlegmatizing and binding a pyrotechnic active mass is known. The composition is a viscoelastic material formed by dissolving the polymer in the ionic liquid or the mixture of ionic liquids, the polymer comprising polyacrylonitrile, polyvinyl nitrate, polyvinylpyrrolidone (PVP) or nitrocellulose.

From the EP 2 698 359 B1 an insensitive explosive substance comprising an explosive and a phlegmatizer is known, the phlegmatizer comprising at least one ionic liquid, the explosive substance further comprising a binder. The binder comprises a polar polymer or polar macromolecule or a polymer or macromolecule which is soluble in the ionic liquid or can be swollen by it.

The well-known pourable and curing high-performance active compound DLE-C038 is hexanitroisowurtzitane (CL-20) in the form of particles of different sizes, which are mixed with a binder consisting of hydroxyl-terminated polybutadiene (HTPB), which is cured using an isocyanate as a hardener became.

The object of the present invention is to provide an alternative binding agent for an explosive which, when binding an explosive, results in the formation of an insensitive explosive substance. Furthermore, a method for producing such a binder is to be specified.

The invention is achieved by the features of claims 1 and 13. Appropriate configurations result from the features of claims 2 to 12 as well as 14 and 15.

According to the invention, a binder for an explosive is provided which comprises at least one ionic liquid and a polymer. The polymer is formed from monomers or molecules of a further polymer which are crosslinked to form an elastic network by means of a crosslinking agent. In order to fulfill its function, the crosslinking agent has at least two functional groups per molecule which react with the monomers or molecules of the further polymer each having at least two functional groups per molecule in order to bring about the crosslinking. A network is understood to mean a polymer extending two-dimensionally or three-dimensionally, i. H. the crosslinked polymer is by no means merely linear. This is achieved in that a small proportion, for example 1%, of the molecules of the crosslinking agent or of the monomers or of the molecules of the further polymer has at least three functional groups. The functional groups of the monomers or the molecules of the further polymer can be, for example, OH groups and the functional groups of the molecules of the crosslinking agent can be isocyanate groups.

The ionic liquid is embedded in the network. The monomers or molecules of the further polymer are preferably polar so that they are soluble in the ionic liquid, which is always polar, or can be swollen or gelled by the ionic liquid. An ionic liquid (= liquid salt) is a liquid which, in contrast to a salt solution or any other liquid containing ions, consists exclusively of ions, whereby a small proportion of impurities does not prevent exclusivity. In contrast to a molten salt, an ionic liquid is already liquid at a temperature below 100 ° C without the salt being dissolved in a solvent such as water. In general, an ionic liquid is an organic salt, the ions of which prevent the formation of a stable crystal through charge delocalization and steric effects.

The inventors have found that the viscoelastic properties of the EP 2 698 359 B1 known insensitive explosive active mass and from the use according to the EP 2 698 361 B1 resulting pyrotechnic active mass change strongly depending on the temperature. When it is hot, the viscosity of the active compound is greatly reduced, while when it is cold it rises sharply, thereby hardening the active compound. This hardening increases the sensitivity to mechanical stress, so that when it is cold, mechanical stress, such as a blow, can lead to an undesired conversion or detonation of the active material.

The inventors have recognized that the advantageous properties of the known active composition containing a polymer and an ionic liquid can be maintained over a wide temperature range and at the same time the temperature dependence of the viscoelastic properties can be reduced if the polymer forms a two-dimensional or three-dimensional network in which the ionic liquid is incorporated. By crosslinking the monomers or the molecules of the further polymer, migration of the ionic liquid within the binder is avoided or at least greatly reduced and the temperature dependence of the mechanical properties of the binder is greatly reduced.

Such a binder can be produced by the method according to the invention, in which the monomers or the molecules of the further polymer, the ionic liquid and the crosslinking agent and optionally the explosive for crosslinking the monomers or molecules of the further polymer are mixed with one another in a crosslinking reaction and the resultant Mixture is incubated. Incubation allows crosslinking to occur. The incubation usually takes place until the crosslinking reaction is complete. The crosslinking can be accelerated by adding heat. During the incubation, the binding agent can be brought into shape with any explosives it may contain, for example by pouring it into an appropriate ammunition casing or introducing it in some other way.

The monomers or molecules of the further polymer can be dissolved or swollen in the ionic liquid, in particular before mixing with the explosive and / or with the crosslinking agent or also during this. The crosslinking agent can then before, during or after dissolving with the ionic Liquid can be mixed. The mixture can be heated to accelerate the crosslinking reaction. Alternatively or additionally, a catalyst which catalyzes the crosslinking reaction, in particular iron acetylacetonate to activate isocyanate groups in the crosslinking agent, can be mixed with the monomers or molecules of the further polymer, the ionic liquid and the crosslinking agent and optionally the explosive to accelerate the crosslinking reaction. For this purpose, the catalyst can be added before, during or after the mixing of individual components mentioned or of a resulting mixture. For example, it can also be dissolved in the ionic liquid before the monomers or molecules of the further polymer are brought into contact with the ionic liquid.

The monomers and the molecules of the further polymer and / or the ionic liquid can be selected such that the decomposition temperature of the crosslinked polymer or the ionic liquid is lower than the decomposition temperature of the explosive. As a result, the safety of an explosive active compound containing the binder according to the invention, which is contained in a solid, closed container, is significantly increased if the container with the explosive active compound is slowly heated, as is done, for example, in the event of a fire or simulated in the so-called cook-off test. The reason for this is that the container is broken open before the explosive can react due to an early decomposition of the polymer or the ionic liquid due to an increase in temperature and the resulting pressure inside the container. A detonation of a warhead or a projectile in the event of a fire can thereby be prevented or the detonation effect of the explosive substance contained therein can at least be greatly reduced.

The further polymer can comprise or consist of a linear, ie unbranched, polymer or an energetic polymer. The energetic polymer can be a linear polymer. An energetic polymer is understood to mean a polymer which, after ignition or ignition, releases energy, in particular at least 1 kJ / g, by reaction without external oxidizing agents, such as atmospheric oxygen. Such polymers usually carry energetic groups such as azido groups, nitro groups, nitramine groups or nitrate groups. Energetic polymers which are well suited for the binder according to the invention are, for example, nitrocellulose (NC) or polyvinyl nitrate (PVN). NC and PVN are usually always incompletely nitrided, ie not all in the underlying Base molecule cellulose or polyvinyl alcohol containing OH groups have been esterified during the nitration of the base molecule. NC and PVN are available commercially with different N contents. For example, an NC with an N content of 12% has proven to be well suited for the binder according to the invention. In commercially available NC and commercially available PVN there are always molecules with at least two or three free OH groups that are available for a crosslinking reaction with the crosslinking agent. The presence of molecules with only one or no free OH group is harmless because these molecules cannot be crosslinked to form a network and thus even act as plasticizers in the binder according to the invention, which reduces the sensitivity of an explosive bound therewith.

In addition to the energetic polymer, the binder can comprise at most 50% by weight of a non-energetic polymer. The non-energetic polymer can be an epoxy resin, a polyester, polytetrahydrofuran, polyethylene glycol or polypropylene glycol. A proportion of more than 50% by weight of a non-energetic polymer leads to a relatively strong reduction in the performance of an active explosive composition containing the binder according to the invention.

The crosslinking agent can be an, in particular aliphatic, diisocyanate, triisocyanate, polyisocyanate or a mixture of at least two of these isocyanates, an, in particular di-, tri- or polyfunctional, epoxide, in particular a bisphenol-A-based epoxide, or a, in particular di -, tri- or polyfunctional, include or consist of acid anhydride. The diisocyanate can be hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPI), tolylene diisocyanate (TDI) or methylenediphenyl diisocyanate (MDI). The triisocyanate can be, for example, hexamethylene triisocyanate, hexamethylene diamine biuret or a biuret triisocyanate. A suitable mixture of hexamethylene diisocyanate and hexamethylene diamine biuret is sold by Covestro AG under the trade name "Desmodur® N100". However, only a relatively small amount of this mixture should be used in the binder according to the invention in order to avoid a relatively strong crosslinking and thus a relatively high hardness of the binder.

In one embodiment of the binder according to the invention, molecules of the crosslinking agent each have at least three functional ones that are each suitable for forming a bond with one of the monomers or the molecules of the further polymer Groups, in particular isocyanate groups, on. As an alternative or in addition, the monomers or molecules of the further polymer can each have at least three functional groups, in particular OH groups, each suitable for forming a bond with a molecule of the crosslinking agent. It has proven to be advantageous if at least 1% of the molecules of the crosslinking agent or the monomers or molecules of the further polymer or 1% of the total molecules of the crosslinking agent and the monomers or molecules of the further polymer have at least three functional groups. As a result, good immobilization of the ionic liquid can be ensured by forming an at least two-dimensional network.

It is also favorable if the ionic liquid is insoluble in water and, in particular, insoluble in water and not hygroscopic. This can prevent the composition and the properties of the binder according to the invention from changing due to water absorbed, in particular from the air.

The ionic liquid can contain a perchlorate, nitrate, acetate, dicyanamide, hexafluorophosphate or tetrafluoroborate ion as the anion. As a cation, the ionic liquid can contain an alkylimidazolium ion, an alkyl-alkylimidazolium ion, an alkyl-methylimidazolium ion, in particular a dimethylimidazolium ion or ethylmethylimidazolium ion, a tetrazolium ion or a triazolium ion. The ionic liquid can be, for example, an alkyl imidazolium perchlorate, an alkyl alkyl imidazolium perchlorate, an alkyl imidazolium tetrafluoroborate, an alkyl alkyl imidazolium tetrafluoroborate, alkyl imidazolium dicyanamide or an alkyl alkyl imidazolium dicyanamide. Suitable ionic liquids are, for example, 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF ₄ ), 1-butyl-3-methylimidazolium dicyanamide (BMIM-C ₂ N ₂ ) or n-butylmethylimidazolium perchlorate (BMIM-ClO ₄ ). With regard to the use of the binder for an explosive, it is advantageous if the ionic liquid is an energetic ionic liquid, in particular n-butylmethylimidazolium perchlorate (BMIM-ClO ₄ ). An energetic ionic liquid is one that releases energy, in particular at least 1 kJ / g, after ignition or ignition without the need for an additional oxidizing agent, such as, for example, atmospheric oxygen. In this way it is possible to provide a binding agent which releases at least 1 MJ / kg of energy when an explosive bound therewith is reacted.

In order to achieve the highest possible density of an explosive active composition containing the binder, it is also advantageous if the ionic liquid is one whose density is at least 1000 kg / m ³ , in particular at least 1100 kg / m ³ .

The binder can be contained in an explosive active compound comprising an explosive, in particular a crystalline explosive. The explosive can be octogen, hexogen, nitropenta (PETN), triaminotrinitrobenzene (TATB), diaminodinitroethylene (FOX-7), hexanitroisowurtzitane (CL-20) or dihydroxyl-ammonium-5,5'-bistetrazole-1,1 '-diolate (TKX-50).

Fig. 1

Das Ergebnis einer Messung eines nicht vernetzten Bindemittels gemäß dem Stand der Technik,

Fig. 2

das Ergebnis einer Messung eines erfindungsgemäßen Bindemittels,

Fig. 3

die Ergebnisse von Messungen von zwei Bindemitteln gemäß dem Stand der Technik und einem erfindungsgemäßen Bindemittel,

Fig. 4

das Ergebnis einer Messung eines zweiten erfindungsgemäßen Bindemittels,

Fig. 5

das Ergebnis einer Messung eines dritten erfindungsgemäßen Bindemittels,

Fig. 6

das Ergebnis einer Messung eines vierten erfindungsgemäßen Bindemittels,

Fig. 7

das Ergebnis einer Messung eines fünften erfindungsgemäßen Bindemittels und

Fig. 8

das Ergebnis einer Messung eines sechsten erfindungsgemäßen Bindemittels.

The invention is explained in more detail below on the basis of exemplary embodiments. All of the following figures show the result of rheological measurements of various binders over the specified temperature ranges. The results are shown as values for the storage modulus G 'and the loss modulus G ". They show:

Fig. 1

The result of a measurement of a non-crosslinked binder according to the prior art,

Fig. 2

the result of a measurement of a binder according to the invention,

Fig. 3

the results of measurements of two binders according to the prior art and one binder according to the invention,

Fig. 4

the result of a measurement of a second binder according to the invention,

Fig. 5

the result of a measurement of a third binder according to the invention,

Fig. 6

the result of a measurement of a fourth binder according to the invention,

Fig. 7

the result of a measurement of a fifth binder according to the invention and

Fig. 8

the result of a measurement of a sixth binder according to the invention.

The reagents for the preparation of active explosives containing binders are given in the tables below. 1 kg of each of the explosive active masses was produced. In the case of the active explosives containing nitrocellulose (NC), the NC was first dissolved in a mixture of acetone and ethyl acetate in a ratio of 1: 1. The respective ionic liquid, the respective isocyanate and the iron acetylacetonate serving as a catalyst were then each added to this solution and then stirred for a few minutes using a magnetic stirrer in order to obtain a homogeneous mixture. Approx. 400 ml of the acetone-ethyl acetate mixture were used in each case. Instead of the acetone-ethyl acetate mixture used, ethanol, ethanol and ethyl ether in a ratio of 2: 1, ethanol and acetone in a ratio of 2: 1 or ethanol-ethyl acetate in a ratio of 2: 1 or any other solvent or solvent mixture that both the to crosslinking monomers or molecules of the further polymer dissolves and is also miscible with the ionic liquid, can be used.

The dried explosive is slurried into the resulting solution, and the resulting mixture is poured into a mixer and mixed therein. After 5 minutes, the mixture is heated to about 70 ° C. and the pressure is gradually reduced to below 2 mbar in order to completely draw off the acetone-ethyl acetate mixture. As a result, the explosive crystals are coated with the binder. After the solvent had been removed, the mixing and heating of the mixer were ended and the pressure in the mixer was adjusted to atmospheric pressure again. After opening the mixer, a slightly sticky, colorless, powdery mass that was easy to dose was found in it. This was removed and in each case 24 g of it was pressed into a tablet in a pressing tool having a diameter of 21 mm. Tablets produced in this way were used in a gap test.

The gap test is a standard test for determining the insensitivity of explosive substances or explosives. The height of a standardized water column, referred to as a "gap" or "gap", is measured which is sufficient to transfer a shock wave generated by detonation of a standard explosive charge in the water column to the explosive substance to be examined, so that it still detonates reliably or reliably no longer detonated. the Values are given in mm of the water column. In the following tables, the first value under "Gap [mm]" denotes the value at which the explosive substance to be investigated still reliably detonates ("GO") and the second value the value at which the explosive substance to be investigated is no longer reliable detonated ("NO GO"). The lower these values are, the more insensitive the explosive substance is. In the tables below, “TMD” denotes the theoretical maximum density of the respective explosive active mass, given ^{in kg / m 3.}

Example 1 - state of the art:

Mixture for the production of the known compressible, insensitive explosive active compound DXP-1340 containing a plasticizer: material Type Wt% miscellaneous Acrylate rubber Hytemp 4454 1.0 TMD = 1833 Dioctyl adipate (DOA) Plasticizers 3.0 Octogen NSO 137 sieved 630 µm 67.2 Octogen NSO 152 28.8

Example 2 - state of the art:

Mixture for making one from the EP 2 698 359 B1 known pressable, fully energetic, insensitive explosive substance containing an ionic liquid: material Type Wt% miscellaneous Nitrocellulose Hawthorn H24 1.75 BMIM-ClO ₄ self-synthesized 5.25 TMD = 1853 Octogen NSO 137 sieved 630 µm 65.7 Octogen NSO 152 27.3

Example 3:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Nitrochemie TLP-NC 0.70 BMIM-ClO ₄ self-synthesized 6.30 TMD = 1849 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 Hexamethylene diisocyanate Sigma-Aldrich 52649 0.0175 Iron acetylacetonate Merck 8.03912.0250 0.0035

Example 4:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Synthesia Grade E 1.398 BMIM-ClO ₄ self-synthesized 5,593 TMD = 1852 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 Hexamethylene diisocyanate Sigma-Aldrich 52649 0.006 Iron acetylacetonate Merck 8.03912.0250 0.003

Example 5:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Synthesia Grade E 1.748 BMIM-ClO ₄ self-synthesized 5.243 TMD = 1854 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 Hexamethylene diisocyanate Sigma-Aldrich 52649 0.006 Iron acetylacetonate Merck 8.03912.0250 0.003

Example 6:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Synthesia E37 1,747 BMIM-ClO ₄ self-synthesized 5.241 TMD = 1854 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 Hexamethylene diisocyanate Sigma-Aldrich 52649 0.008 Iron acetylacetonate Merck 8.03912.0250 0.003

Example 7:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Synthesia Grade E 1,747 BMIM-ClO ₄ self-synthesized 5.241 TMD = 1854 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 Hexamethylene diisocyanate Sigma-Aldrich 52649 0.008 Iron acetylacetonate Merck 8.03912.0250 0.003

Example 8:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Synthesia Grade E 1.048 BMIM-ClO ₄ self-synthesized 5.241 TMD = 1856 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 Hexamethylene polyisocyanate Desmodur ® N100 0.008 Iron acetylacetonate Merck 8.03912.0250 0.003

Example 9:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Synthesia E37 1.744 BMIM-ClO ₄ self-synthesized 5.232 TMD = 1854 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 Hexamethylene diisocyanate Sigma-Aldrich 52649 0.021 Iron acetylacetonate Merck 8.03912.0250 0.003

Example 10:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Synthesia E37 1.744 BMIM-ClO ₄ self-synthesized 5.233 TMD = 1854 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 Hexamethylene polyisocyanate Desmodur ® N100 0.020 Iron acetylacetonate Merck 8.03912.0250 0.003

Example 11:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Synthesia Grade E 1.744 BMIM-ClO ₄ self-synthesized 5.233 TMD = 1854 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 Hexamethylene polyisocyanate Desmodur ® N100 0.020 Iron acetylacetonate Merck 8.03912.0250 0.003

Example 12:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Nitrochemie TLP-NC 0.689 BMIM-ClO ₄ self-synthesized 6.204 TMD = 1848 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 pG-DiNCO Sigma-Aldrich 433497 0.103 Iron acetylacetonate Merck 8.03912.0250 0.003 pG-DiNCO = polypropylene glycol, toluene (2,4) di-isocyanate-terminated

Example 13:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Nitrochemie TLP-NC 0.692 BMIM-ClO ₄ self-synthesized 6.231 TMD = 1848 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 pG-DiNCO Sigma-Aldrich 433497 0.069 Iron acetylacetonate Merck 8.03912.0250 0.007 pG-DiNCO = polypropylene glycol, toluene (2,4) di-isocyanate-terminated

Example 14:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Nitrochemie TLP-NC 0.689 BMIM-ClO ₄ self-synthesized 6,201 TMD = 1848 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 pG-DiNCO Sigma-Aldrich 433497 0.103 Iron acetylacetonate Merck 8.03912.0250 0.007 pG-DiNCO = polypropylene glycol, toluene (2,4) di-isocyanate-terminated

Example 15:

Mixture for the production of a pressable, an ionic liquid and the binder according to the invention containing fully energetic insensitive explosive active mass with an ionic liquid, a further polymer and a crosslinking agent: material Type Wt% miscellaneous Nitrocellulose Nitrochemie TLP-NC 0.692 BMIM-ClO ₄ self-synthesized 6.225 TMD = 1849 Octogen NSO 137 sieved 630 µm 65.1 Octogen NSO 152 27.9 pG-DiNCO Sigma-Aldrich 433497 0.069 Iron acetylacetonate Merck 8.03912.0250 0.014 pG-DiNCO = polypropylene glycol, toluene (2,4) di-isocyanate-terminated

i ist dabei die imaginäre Einheit der komplexen Zahl G*. Der Speichermodul G' ist proportional zu dem Anteil der Deformationsenergie, der im Bindemittel gespeichert wird und nach Entlastung wieder aus dem Bindemittel gewonnen werden kann. Der Verlustmodul G" entspricht dem Verlustanteil der Energie, welche durch innere Reibung in dem Bindemittel in Wärme umgewandelt wird. Die Bindemittelproben mit Vernetzungsagens wurden jeweils zunächst bei der höchsten dargestellten Temperatur so lange gemessen, bis der Speichermodul G' nicht mehr angestiegen ist. Dies zeigte den Abschluss der Vernetzungsreaktion an. Anschließend wurde die Temperatur langsam über den in den Figuren jeweils angegebenen Temperaturbereich abgesenkt.In the Figures 1 to 8 the results from rheometric measurements of the rheological properties of the binders of some of the above explosive active compounds are shown in each case. For these measurements, the binder was not mixed with the respective explosive. The storage modulus G 'indicates the value for the elastic component and the loss modulus G "the value for the viscous component of the complex shear modulus G * defined in the form of a complex number as follows: $$\mathrm{G}*=\mathrm{G}+\mathrm{i}\cdot \mathrm{G}$$

i is the imaginary unit of the complex number G *. The storage modulus G 'is proportional to the portion of the deformation energy that is stored in the binding agent and can be recovered from the binding agent after the load is removed. The loss modulus G ″ corresponds to the proportion of energy lost which is converted into heat by internal friction in the binder. The binder samples with crosslinking agent were each measured at the highest temperature shown until the storage modulus G 'no longer increased. This was shown The temperature was then slowly reduced over the temperature range indicated in each case in the figures.

Fig. 1 shows the result of the rheometric measurement of the binder from Example 2. This binder contains nitrocellulose and an ionic liquid, but no crosslinking agent. The course of the curves in Fig. 1 shows that the storage modulus G 'changes in the temperature range from +80 ° C to -60 ° C from 5 Pa to 500 kPa, ie over 5 orders of magnitude.

Fig. 2 shows the result of the corresponding rheometric measurement for the binder composition according to the invention contained in Example 3, which contains the crosslinking agent hexamethylene diisocyanate and the catalyst iron acetylacetonate which catalyzes the crosslinking. The figure shows that the storage modulus G 'here in the range from +80 ° C. to -60 ° C. changes significantly less than in the case of the binder from example 2.

Fig. 3 shows the results of the measurements of the binder compositions from Example 1 ("Hytemp / DOA 25/75"), Example 2 ("NC / BMIM-ClO ₄ 25/75") and Example 3 ("NC / BMIM-ClO ₄ / HDMI 90 /10/0.055 "). Fig. 3 clearly shows the effect of the networking. The binder from Example 1, which is used as a reference, is also crosslinked. However, this binder is not energetic and therefore results in a reduced

Performance of an explosive active composition containing this binding agent compared to the performance achievable with the binding agent according to the invention if it contains an energetic further polymer and / or an energetic ionic liquid.

Fig. 4:

Bindemittel aus Beispiel 4

Fig. 5:

Bindemittel aus Beispiel 8

Fig. 6:

Bindemittel aus Beispiel 12

Fig. 7:

Bindemittel aus Beispiel 13

Fig. 8:

Bindemittel aus Beispiel 14

The results shown in the other figures were determined as follows with the binders from the other examples:

Fig. 4:

Binder from example 4

Fig. 5:

Binder from example 8

Fig. 6:

Binder from example 12

Fig. 7:

Binder from example 13

Fig. 8:

Binder from example 14

Compared to uncrosslinked binders, the results show a significantly reduced change in the storage modulus G 'as a function of the temperature.

The results of the gap tests are listed in Table 1 below: Table 1: material TMD / (kg / m ³ ) Density / (kg / m ³ ) % TMD Gap / mm Result Tg / ° C Insensitive? % Plasticizer example 1 1833 1810 98.7 12/13 GO / NO GO -55 Yes DOA Example 2 1853 1840 99.3 12/13 GO / NO GO <-60 Yes BMIM-ClO ₄ Example 3 1849 1820 98.5 12/13 GO / NO GO <-60 Yes BMIM-ClO ₄

In the gap test, the limit value of the gap for an insensitive explosive is 15 mm. If the gap is equal to or smaller than 15 mm and the explosive does not detonate repeatedly, it is classified as insensitive. In all of the examples in the above table, no detonation took place at a gap of 13 mm, so that the tested explosive substances can all be classified as insensitive. "Tg" means "glass transition temperature" in the table above. The glass transition temperature was measured by means of dynamic difference calorimetry (DSC). For military purposes, the glass transition temperature should be below -54 ° C. This is easily achieved for the active composition according to the invention according to Example 3.

Table 2 below shows the performance data calculated and measured for Examples 1 to 3 at the densities actually achieved in accordance with Table 1 above. The measured values are given in brackets. Table 2: material D / (m / s) p / GPa example 1 8850 (8615) 33.0 Example 2 8860 (8630) 34.5 Example 3 8770 33.5

Claims (15)

Binder for an explosive, comprising at least one ionic liquid and one polymer,
characterized,
that the polymer is formed from monomers or molecules of a further polymer crosslinked by means of a crosslinking agent to form an elastic network, the ionic liquid being embedded in the network. Binder according to claim 1,
characterized,
that the further polymer comprises or consists of a linear polymer or an, in particular linear, energetic polymer, in particular nitrocellulose (NC) or polyvinyl nitrate (PVN). Binder according to claim 2,
characterized,
that the binder, in addition to the energetic polymer, comprises at most 50% by weight of a non-energetic polymer, in particular an epoxy resin, a polyester, polytetrahydrofuran, polyethylene glycol or polypropylene glycol. Binder according to one of the preceding claims,
characterized,
that the crosslinking agent comprises or consists of a, in particular aliphatic, diisocyanate, triisocyanate, polyisocyanate or a mixture of at least two of these isocyanates, an epoxide, in particular a bisphenol-A-based epoxide, or an acid anhydride. Binder according to claim 4,
characterized,
that the diisocyanate is hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPI), tolylene diisocyanate (TDI) or methylenediphenyl diisocyanate (MDI) and the triisocyanate is hexamethylene triisocyanate, hexamethylene diamine biuret or a biuret triisocyanate. Binder according to one of the preceding claims,
characterized,
that either molecules of the crosslinking agent each have at least three functional groups each suitable for forming a bond with one of the monomers or the molecules of the further polymer, in particular isocyanate groups, and / or the monomers or molecules of the further polymer each at least three each for forming a bond with one Molecule of the crosslinking agent have suitable functional groups, in particular OH groups. Binder according to one of the preceding claims,
characterized,
that the ionic liquid is insoluble in water, in particular insoluble in water and not hygroscopic. Binder according to one of the preceding claims,
characterized,
that the ionic liquid has a perchlorate, nitrate, acetate, dicyanamide, hexafluorophosphate or tetrafluoroborate ion as the anion and / or an alkylimidazolium ion, an alkyl-alkylimidazolium ion, an alkyl-methylimidazolium ion, in particular dimethylimidazolium Ion or ethylmethylimidazolium ion, a tetrazolium ion or a triazolium ion as a cation. Binder according to one of the preceding claims,
characterized,
that the ionic liquid is 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF ₄ ), 1-butyl-3-methylimidazolium dicyanamide (BMIM-C ₂ N ₂ ) or n-butylmethylimidazolium perchlorate (BMIM-ClO ₄ ). Binder according to one of the preceding claims,
characterized,
that the ionic liquid is an energetic ionic liquid, in particular n-butylmethylimidazolium perchlorate (BMIM-ClO ₄ ). Binder according to one of the preceding claims,
characterized,
that the ionic liquid is one whose density is at least 1000 kg / m ³ , in particular at least 1100 kg / m ³ . Binder according to one of the preceding claims,
characterized,
that the binding agent is contained in an explosive substance, in particular octogen, hexogen, nitropenta (PETN), triaminotrinitrobenzene (TATB), diaminodinitroethylene (FOX-7) or hexanitroisowurtzitane (CL-20). Method for producing a binder according to one of the preceding claims, characterized in that - The monomers or molecules of the further polymer, the ionic liquid and the crosslinking agent
or - The monomers or molecules of the further polymer, the ionic liquid, the crosslinking agent and the explosive
for crosslinking the monomers or molecules of the further polymer are mixed with one another in a crosslinking reaction and the mixture resulting therefrom is incubated. Method according to claim 13,
characterized,
that the monomers or molecules of the further polymer, in particular before mixing with the explosive and / or with the crosslinking agent, are dissolved or swollen in the ionic liquid. Method according to claim 13 or 14,
characterized,
that a catalyst which catalyzes the crosslinking reaction, in particular iron acetylacetonate, is mixed with the monomers or molecules of the further polymer, the ionic liquid and the crosslinking agent and optionally the explosive.

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