Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
  • C06B45/04—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive
  • C06B45/06—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component
  • C06B45/10—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component the organic component containing a resin
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B21/00—Apparatus or methods for working-up explosives, e.g. forming, cutting, drying
  • C06B21/0008—Compounding the ingredient
  • C06B21/0025—Compounding the ingredient the ingredient being a polymer bonded explosive or thermic component

Definitions

• the present invention relates to composite pyrotechnic products, particularly suitable as propellant powders for tube weapons (more particularly for tank artillery). These are composite pyrotechnic products, which contain a high level of energetic charges in a binder. These products are particularly interesting, especially in terms of strength (of energy power), vulnerability (see below a reminder on this concept, familiar to the skilled person), and scope of application as to the nature of loads that they can contain. They can opportunely be optimized in terms of erosivity.
• the present invention also relates to a process for preparing said composite pyrotechnic products. Said method is particularly easy to implement.
• propellant powders consisting of one or more gelatinized energy bases having a homogeneous appearance (hence their name).
• homogeneous propellant powders mention may be made of "smoke-free" powders based on nitrocellulose alone or based on a nitrocellulose-nitroglycerine mixture.
• organic (powdery) energy charges In order to improve the energy performance of these "homogeneous" powders, it has been sought to incorporate organic (powdery) energy charges. These charged powders no longer have a homogeneous appearance, but a heterogeneous appearance in which we distinguish on the one hand, the energy binder and on the other hand, the charges.
• Such charged powders are called “composite” or “heterogeneous”.
• Such charged powders are for example described in the French patent application FR 2,488,246.
• nitrocellulose energy binder has the disadvantage of making these powders vulnerable.
• Vulnerability is defined as the property that powders can be able to ignite and deflag under the effect of a physical, random, undesired phenomenon, such as the impact of a projectile. Vulnerability is a major defect for powders intended to be loaded on board battle tanks The development of modern combat gear has therefore led the skilled person to search for propellant powders that are not very vulnerable.
• inert binder composite powders consisting mainly of organic energy charges in a synthetic resin.
• Such powders are much less vulnerable than homogeneous powders or composites with energy binders (nitrocellulose).
• energy binders nitrocellulose.
• these powders must, in order to deliver the necessary energy during firing, contain very high levels of charges, often close to 80% of the total mass of the powder.
• the inert binder composite powders thus have the characteristic of containing very little binder with respect to their powdery filler.
• the precursor mixtures of these powders must, however, be able to be worked (in particular being able to be calendered or spun through a die of relatively small diameter, most often including pins intended to create the channels present in the final strand of powder), and the powders must keep their geometric shape in time. It is particularly with reference to obtaining these composite propellant powders with inert binder for tube weapons that the skilled person has encountered and still faces serious difficulties.
• thermoplastic binders of synthetic origin, that can be used in the preparation of composite pyrotechnic products and present in their composition, exist to date as thermoplastic binders and as thermosetting binders (obtained from oligomers).
• thermoplastic binders allow, in theory, temperature, a mechanical work of the product to give it the desired geometry. It should, however, of course, that the working temperature (to which the binder is deformable) is compatible with the stability of the present charges and, with reference to this unavoidable requirement, it is often necessary to involve a solvent. The intervention of such a solvent increases the implementation of the process.
• the patent application EP 0 036 481 describes a process for manufacturing composite explosives with a thermoplastic binder.
• the patent application IN 498 / DEL / 2001 discloses a method of preparing propellant containing hexogen (RDX) fillers in a thermoplastic binder.
• RDX hexogen
• thermosetting binders obtained from oligomers
• polyurethane binders crosslinkable
• thermosetting binders
• thermosetting binders To operate without solvent, with thermosetting binders, said skilled in the art has made extensive use of the so-called “casting” or “global” technique, which consists in simultaneously mixing in a kneader the liquid elemental constituents of the resin and the energy charges and to cast, before polymerization, the mixture thus obtained in a mold to conduct the polymerization itself.
• This technique which has been widely described, for example in the French patent applications FR 2 109 102, FR 2 196 998, FR 2 478 623 and FR 2 491 455, may be suitable for the manufacture of solid composite propellants for rocket engines, rockets, or the manufacture of composite explosives for gear heads, which are most often used in the form of large diameter products, but is totally unsuitable for the industrial manufacture of large, medium-sized composite powders and small calibres and more generally to that of certain composite pyrotechnic products;
• thermosetting inert binder especially small diameters
• the first which consists in mixing in a kneader the constituents of the resin with the energetic charges, to initiate the crosslinking of the resin and, during crosslinking, to perform, in a very short time, the shaping of the product, as described for example in the French patent applications FR 1 409 203 and FR 2 159 826.
• This technique requires a sharp adjustment of the kinetics of crosslinking to allow the dough to work and because of this, it is difficult to manage at industrial scale;
• the composite pyrotechnic products obtained by this second technique mainly consist, on the one hand, of a polymeric binder (for example polyurethane) obtained by reaction of a polyhydroxylated prepolymer (having a number-average molecular weight of between 2000 and 5000 and an average functionality of hydroxyl groups (OH greater than 2 and less than 3) (PBHT, polyether) , polyester, for example) with a crosslinking agent (diisocyanate), and secondly, by an energetic charge, preferably octogen (HMX) or hexogen (RDX), at a rate of about 80% by weight.
• a polymeric binder for example polyurethane
• a first step mixing said polyhydroxy prepolymer with said energetic charge and with a quantity of diisocyanate of between 50% and 90% by weight of the stoichiometric quantity necessary for the complete polymerization (reaction) of all the hydroxyl groups (OH) said prepolymer and performing the condensation reaction of the isocyanate groups (NCO) on the hydroxyl groups (OH) so as to obtain a partially polymerized (crosslinked) paste; + in a second step, to mix with said pulp partially polymerized (crosslinked) thus obtained the complement of diisocyanate necessary to reach said stoichiometric quantity necessary for the complete polymerization (crosslinking) and to extrude the pasty mixture thus obtained; then,
• the technique in question thus comprises two polymerization or crosslinking steps, more specifically a first pre-crosslinking step (or first crosslinking step) with an amount of isocyanate allowing a partially polymerized (crosslinked) paste to be obtained, exhibiting adequate mechanical strength and cohesion for the implementation of the continuation of the process (in particular extrusion) and a second crosslinking step leading to the final product with the desired crosslinked binder.
• said technique overcomes the two types of difficulties mentioned above (difficulty due to the lack of mechanical strength and cohesion of the product to be extruded and the problem of the "pot life").
• the dosages of the crosslinking agent (diisocyanate) for the implementation of the pre-crosslinking are delicate. They require great precision.
• the field of application of said technique is limited, in view of the nature of the intervening crosslinking agent (of isocyanate type, to react with hydroxyl functions), as to the nature of the energy charges present, in the as some energy charges (having intrinsic acidity) are likely to react, in a parasitic reaction, with said crosslinking agent (isocyanate type) present.
• the presence of such fillers (EDNA, nitropyrazoles, for example) is therefore problematic for managing the steps of pre-crosslinking and complementary crosslinking.
• composite pyrotechnic products particularly suitable as propellant powders for tube weapons, of a new type.
• These (new) composite pyrotechnic products contain a high level of filler in a binder of a new type (this binder is neither a thermoplastic binder nor a thermoset binder).
• the present invention thus relates to new composite pyrotechnic products. Characteristically, their compositions, expressed in percentages by weight, contain:
• a polymeric gum chosen from polyurethane-polyester gums, polyurethane-polyether gums and mixtures thereof, the number-average molecular mass of which is greater than 20,000 g / mol and the Mooney viscosity of which is between 20 and 70 ML (5 +4) at 100 ° C.
• the composite pyrotechnic products of the invention therefore contain a high level of organic energy charges in a binder of a new type: a binder, gum type ("raw rubber"), uncrosslinked. It is seen further that said binder is likely to contain a plasticizer.
• the composite pyrotechnic products of the invention therefore contain a high level of organic energy charges: from 78 to 90% by weight, advantageously from 80 to 86% by weight.
• organic charges of any type (not selected, as in the context of heat-crosslinkable binders, taking into account the crosslinking reaction to be implemented later), the mineral fillers being discarded insofar as they generate solid particles) are not per se original.
• organic energy charges known per se and, for the most part, already packaged according to the prior art in a conventional organic polymeric binder (such as PBHT), in particular crosslinked.
• RDX hexogen
• HMX octogen
• NGU nitroguanidine
• EDNA ethylene dinitramine
• GUDN dinitramide N-guanylurea
• 1,1-diamino-2,2-dinitroethylene FOX 7 (DADE)
• TAGZT bis (triaminoguanidinium) 5'-azotetrazolate
• DHDZT dihydrazinium 5,5'-azotetrazolate
• HBT bis (2,2-dinitropropyl) nitramine
• BDNPN 2,2-dinitropropyl) nitramine
• organic energetic charges of EDNA particularly preferably, there is a mixture of EDNA feeds and RDX feeds. It is by no means excluded to find only RDX loads or EDNA loads, but as noted above, mixes of EDNA loads and RDX loads can achieve an optimum in reference to the strength tradeoff. / erosivity. It is understood that the more these mixtures contain RDX, the more they are energetic but the more they are erosive.
• the energy charges are in the form of solid grains, distributed homogeneously within the binder. These solid grains suitably have, in a known Persian manner, several particle size distributions.
• the organic energy charges are therefore within an original binder.
• Said original binder is based on an eraser of the type specified. According to a variant, it consists essentially of said gum (at least one additive being present in a small amount), or it consists of said gum. According to another variant, it consists essentially of said gum and at least one plasticizer (at least one additive being present in a small amount), or it consists of said gum and at least one plasticizer.
• Said eraser is chosen from polyurethane-polyester gums (ie of the polyurethane type with flexible segments of polyester type), polyurethane-polyether gums (ie polyurethane-type polyurethane-type hoses) and their mixtures,
• Such a rubber is perfectly suitable for the purposes of the invention, insofar as, in the proportions indicated (only 10 to 22%, it is recalled that high load products are involved), 1) it allows to work mechanically mixing (charges + gum) at low temperature, ie at a temperature below 120 ° C, or even below 100 ° C (fully compatible with the stability of the present charges), and without the use of solvent; and 2) it gives the final product the mechanical and cohesive strength required.
• Said gum generally consists of a polyurethane-polyester gum or a polyurethane-polyether, but mixtures of at least two gums (at least two polyurethane-polyester gums, at least two polyurethane-polyether gums or at least one polyurethane-polyester gum and at least one polyurethane-polyether gum, such gum mixtures (gums within the meaning of the invention) constituting a gum within the meaning of the invention) having the required properties (mentioned above) may be used.
• Said gum advantageously consists of a polyurethane-polyester gum.
• composition of the composite pyrotechnic products of the invention is therefore likely to contain at least one plasticizer.
• at least one plasticizer (energetic or non-energetic), present, is generally at a level of 2 to 8% by weight (of the total composition).
• Such at least one plasticizer advantageously consists, with reference to the strength of the product, in at least one energetic plasticizer.
• composition of the composite pyrotechnic products of the invention therefore advantageously contains at least one energetic plasticizer (an energetic plasticizer, at least two energetic plasticizers, or at least one energetic plasticizer and at least one non-energetic plasticizer), very advantageously it contains a plasticizer energy.
• the energy plasticizer (s) in question is (are) advantageously of the nitrate and / or nitramine type.
• the energy plasticizer (s) in question is (are) very advantageously chosen from diethylene glycol dinitrate. (DEGDN), triethylene glycine dinitrate (TEGDN), butanetriol trinitrate (BTTN), trimethylolethane trinitrate (TMETN), a mixture of 2,4-dinitro-2,4-diaza-pentane, 2,4 -dinitro-2,4-diaza-hexane and 3,5-dinitro-3,5-diaza-heptane (and especially DNDA 5.7), the nitrato ethy!
• DEGDN diethylene glycol dinitrate
• TAGDN triethylene glycine dinitrate
• BTTN butanetriol trinitrate
• TMETN trimethylolethane trinitrate
• 2,4-dinitro-2,4-diaza-pentane 2,4 -dinitro-2,4-diaza-hexane
• nitramines especially methyl-2-nitratoethyl-nitramine (methylNENA) and ethyl-2-nitratoethyl-nitramine (ethylNENA) and mixtures thereof.
• methylNENA methyl-2-nitratoethyl-nitramine
• ethylNENA ethyl-2-nitratoethyl-nitramine
• processing agent candellila wax and / or paraffin, for example
• the composite pyrotechnic products of the invention are perfectly suitable as propellant powder for tube weapons. Said composite pyrotechnic products of the invention therefore advantageously consist of such powders.
• the composite pyrotechnic products of the invention, as described above, are also suitable, in particular, as tactical propellant, explosive composition and gas generator.
• Said method constitutes the second object of the present invention. He understands :
• polymeric gum chosen from polyurethane-polyester gums, polyurethane-polyether gums and mixtures thereof, the number-average molecular mass of which is greater than 20,000 g / mol and the Mooney viscosity of which is between 20 and 70 ML ( 5 +4) at 100 ° C;
• a pasty mixture is thus produced, the precursor of the final product aimed at.
• a pasty mixture is advantageously made by twin-screw (extrusion) or bi-cylinder, depending on the amounts to implement. It is usually done at a temperature between 60 ° C and 120 ° C (end values included). It is often carried out at a temperature of 80 ° C. It is understood that this mixing temperature is a function of the nature of the gum and the presence or absence of at least one plasticizer.
• the product is prepared in the desired form (n products are generally prepared). Said third step is therefore analyzed as a step of shaping the dough.
• This formatting can include spinning or calendering.
• the spun product is generally cut into strands (to the desired length).
• Such strands suitable as propellant powders for tube weapons, generally have a length of 2 to 20 mm, for a diameter of 1 to 20 mm (more generally for a diameter of 2 to 15 mm).
• the calendered product in the form of a plate (such a plate generally has a thickness of 10 to 20 mm), is generally cut into platelets.
• steps b and c of said method may comprise:
• UREPAN ® G 641 sold by RheinChemie company (polyaddition product of diphenylmethane diisocyanate and a polyester). It has the following characteristics:
• UREPAN ® G 643 sold by RheinChemie company (polyaddition product of diphenylmethane diisocyanate and a polyester). It has the following characteristics:
• EDNA ethylene dinitramine
• DNEU wet dinitroethylene urea
• the medium was stirred for 30 minutes at room temperature.
• the mixture was poured on a bath of cold water at about 5 ° C. with stirring.
• the solid was then separated from the mother liquors by filtration, and washed several times with distilled water to neutral pH and then filtered off. It was then taken up, wet, for the synthesis of EDNA.
• the decarboxylation step was carried out by adding the
• the reaction medium was then cooled so that the EDNA precipitated.
• the suspension was then filtered and dried. A return of
• the obtaining of EDNA has been confirmed by infra-red.
• Trioxyethylene glycol dinitrate (TEGDN) was obtained by nitration in a sulfonitrile medium of trioxyethylene glycol.
• Composite pyrotechnic products of the invention of three types were prepared and tested. Their mass composition and their force (measured or calculated) are respectively given in Tables 1, 2 and 3 below. Below each of said tables 1, 2 and 3 are specified other characteristics of said products.
• Step b of the process of the invention the pasty mixtures were obtained with a twin cylinder, in a known Persian manner.
• the gum was first introduced between the rolls of the bi-roll (rolling mill), brought to a temperature of 65 ° C. It has been softened. Then, a mixture + plasticizer charges (previously made in a container) was added. To the resulting mixture was then added candelilla wax.
• Step c of the process of the invention the pasty mixtures obtained were introduced into a press pot heated to 80 ° C to effect spinning at a pressure of between 280 and 320 bar. After cutting, we obtained strands of powder (diameter: 10 mm, length: 11 mm).
• Em 1.4% (maximum crush before rupture).
• Em 29.7% (maximum crush before rupture).

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• 2013
  • 2013-11-22 FR FR1302707A patent/FR3013705B1/fr active Active
• 2014
  • 2014-11-21 EP EP14809915.3A patent/EP3071537B1/de active Active
  • 2014-11-21 WO PCT/FR2014/000250 patent/WO2015075327A1/fr active Application Filing
  • 2014-11-21 PL PL14809915T patent/PL3071537T3/pl unknown
  • 2014-11-21 CA CA2930486A patent/CA2930486A1/fr not_active Abandoned
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