Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B21/00—Nitrogen; Compounds thereof
  • C01B21/082—Compounds containing nitrogen and non-metals and optionally metals
  • C01B21/087—Compounds containing nitrogen and non-metals and optionally metals containing one or more hydrogen atoms
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B23/00—Compositions characterised by non-explosive or non-thermic constituents
  • C06B23/002—Sensitisers or density reducing agents, foam stabilisers, crystal habit modifiers
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B31/00—Compositions containing an inorganic nitrogen-oxygen salt
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/01—Particle morphology depicted by an image
  • C01P2004/02—Particle morphology depicted by an image obtained by optical microscopy
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/30—Particle morphology extending in three dimensions
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/54—Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension

Definitions

• the subject of the present invention is a process for obtaining (new) ammonium dinitroamide crystals as well as the new ammonium dinitroamide crystals obtainable by said process.
• the present invention also relates to energy composites containing such crystals.
• Ammonium dinitroamide crystallizes in the P 2i / a space group.
• the crystals of the invention, in this same group, have an original crystallized form, "modified". This is explained in detail below.
• Ammonium dinitroamide corresponds to the formula
• urethane route the nitration and the treatment of the urethane lead to the ammonium salt of N-nitrourethane (ANU).
• ANU N-nitrourethane
• This salt is then nitrated by N 2 O 5 in a continuous reaction to form the N, N-dinitro not isolated and reacted directly with ammonia to form I 1 DNA and regenerate the urethane;
• the so-called sulphamate route the ammonium or potassium sulphamate is nitrated with a low-temperature sulphonitric mixture and then the reaction medium is neutralized and generally concentrated.
• I 1 DNA obtained in solution, was crystallized in a conventional manner (by concentration, by adding a non-solvent and / or cooling ...) .
• Malesa et al. have advocated a recrystallization (Propellants, Explosives, Pyrotechnies, 24, 83-89 (1999)).
• the crude DNA crystals obtained are in the form of rods or even needles, characterized by an important form factor (this parameter, which is conventional, is defined as the ratio, for the crystals, of their greater dimension on their smaller dimension).
• this parameter which is conventional, is defined as the ratio, for the crystals, of their greater dimension on their smaller dimension.
• Such rods or needles are shown in FIGS. 1 and 2 (optical transmission microscope photographs). They have a form factor of about 10.
• Said “prills” are generally obtained, either by melting the DNA with vigorous stirring in a non-solvent liquid and then cooling rapidly, or by using a "prilling" tower, a tower within which the molten DNA is sprayed into a gas stream.
• the Applicant proposes a completely original solution.
• This solution does not rely on a conditioning of the crude crystals obtained but on a modification of the process for obtaining the crystals (of the crystallization process); it is based on the generation of crystals having an original crystallized form, more adapted to their formulation, particularly at high concentration levels.
• Said original crystallized form can be analyzed as a modified crystallized form (with respect to the known crystallized form, characterized by an important form factor) but it should be understood that the modification results from a modification (upstream) of the crystallization process and not a modification (downstream) on crystals obtained according to the crystallization process of the prior art.
• Modifying a crystallization process to generate crystals in an original crystallized form is not an innovative operation in itself. This type of operation, based on the intervention of crystal growth modifiers, has notably been used in processes for the preparation of food sugars. However, it has never been described, to the knowledge of the Applicant, in the context of DNA, with reference to the technical problem of its formulation.
• the inventors have shown, quite surprisingly, that it is possible to intervene on the crystallization of DNA, in order to reduce the crystal form factor, that there are additives crystallization modifiers growth DNA crystals: + soluble in 1 I of DNA crystallization solvents; + performance: able to preferentially adsorb on (and to desorb from) faces that have the fastest growth rate and are therefore present at the ends of the sticks or needles;
• the present invention in aspects of process and product, based on the use of additives (of crystallization) of crystal habit modifiers I 1 DNA. It is the inventors' credit to transpose the concept of modification of the crystallization process in the context of the crystallization of I 1 DNA and have identified performance crystallization modifiers in this context.
• the present invention relates to a process for obtaining ammonium dinitroamidide crystals
• said method comprises:
• crystallization within said solution containing said at least one crystalline facies modifier, by any appropriate treatment.
• the crystallization is implemented in a conventional manner
• the solvent of the solution is selected from the crystallization solvent I 1 DNA, known. It may in particular consist of an alcohol, acetone, acetonitrile or a mixture of these solvents. It is advantageously chosen from alcohols and their mixtures. The use of ethanol-methanol mixtures is particularly recommended.
• the at least one crystalline facies modifier is effective and not excessive.
• the crystalline facies modifier is advantageously effective in small quantities and therefore used in small quantities. This minimizes the risk of polluting the crystals, modifying the properties of said crystals. With reference to these problems, care is taken not to use said crystal facies modifier in excessive amounts. It is generally used in a proportion of less than 5% by weight, relative to the weight of DNA in solution; advantageously at a rate of at most 3% by weight, relative to the weight of DNA in solution.
• the invention relates to the DNA crystals obtainable by the method described above ("modified" crystallization process, by the presence of at least one crystalline facies modifier at its Implementation).
• Said crystals have an original crystallized form, a crystalline facies different from that of the crystals of the prior art, obtained by the "unmodified" crystallization process. Said crystals are characterized by a form factor lower than that of said crystals of the prior art. The growth of said crystals has been thwarted.
• the present invention relates to DNA crystals characterized by a form factor of less than or equal to 5; and more particularly DNA crystals characterized by a form factor of between 1.5 and 5 (values of 1.5 and 5 being included). To date, such crystals have never been described. On reading the foregoing, those skilled in the art have already understood the great interest of these DNA crystals for use in the preparation of energy composites, especially of the propellant or explosive type.
• Energy composites containing energetic charges in a binder, energetic or not, of which at least a part of said energetic charges consist of crystals as described above and / or as obtained by the process described above, constitute the third object of the invention.
• Said composites may contain a high content of said crystals, in any case a higher content than that of crystals of the prior art. Due to the modification of the crystalline facies, part of the problems of steric hindrance can be overcome.
• the energy composites of the invention advantageously contain more than 30%, very advantageously more than 50%, by weight of said crystals. They are likely to contain up to about 70%.
• the modified crystallization proposed is a simple operation, easily extrapolable, the implementation of which does not require specific equipment and does not present any particular pyrotechnic risk. It can also be carried out in inexpensive and non-toxic solvents. Said crystallization is thus much more interesting than the "prilling" techniques mentioned in the introduction to this text.
• Said proposed modified crystallization makes it possible to obtain DNA crystals of particular interest in that they make it possible to use said DNA in energy composites with high charge rates.
• Said DNA crystals are also less hygroscopic than those of the prior art.
• Figures 1 and 2 show DNA crystals of the prior art, the type "stick” or “needle”.
• Figures 3, 4 and 5 show DNA crystals of the invention, respectively obtained after the implementation of Examples 6, 7 and 8.
• the crystal surrounded in FIG. 5 has a mean diameter of 150 ⁇ m.
• the reactor used is a 750 ml jacketed reactor.
• the reactor is equipped with a ball cooler whose end is connected to a desiccant system (silica gel crystals).
• a desiccant system sica gel crystals
• the temperature is controlled in the medium by means of a thermal probe and regulated by a circulation of fluid in the jacket.
• the agitation (marine propeller) of the reaction medium is provided by an electrical system.
• the crystallization system (reactor + refrigerant) is also heated with a heat gun.
• the reactor (flask) is introduced at ambient temperature:
• the mixture is heated at 65 ° C. with stirring for 45 minutes until complete dissolution. It is placed at 400 rpm and the following cooling ramp is applied: cooling of 60 ° to 30 ° C. in 45 min, followed by a plateau of temperature at 30 ° C. for 30 min, then a new cooling of 30 ° C. 2O 0 C (or ambient) in Ih45.
• the suspension is filtered on Buchner (standard filter paper) and then placed in an oven at 40 ° C. for 2 hours. About 240 g of DNA are collected, the average crystal diameter of which is 245 ⁇ m (broad distribution of 50 to 440 ⁇ m). The appearance of crystals is that of white crystallized sugar.
• Crystals obtained according to the prior art (chemically purified crude DNA) and crystals of the invention (those obtained according to Example 6) were used to make explosive pastes. Said crystals come from the same batch of manufacture (in fact, the crystals of the invention are obtained after dissolution of crystals of the prior art and re-crystallization in the presence of a growth modifier). Said pastes have the following weight composition:
• Crystals obtained according to the prior art (chemically purified crude DNA) and crystals of the invention (those obtained according to Example 9) were tested with reference to their hygroscopic properties. Said crystals come from the same batch of manufacture (in fact, the crystals of the invention are obtained after dissolution of crystals of the prior art and re-crystallization in the presence of growth modifiers).
• Moisture uptake was measured using a high precision scale located in a controlled relative humidity chamber. After a drying phase of 25 h, the moisture regain (dm / mO) is lower for I 1 DNA crystallized according to the invention for DNA crystallized in conventional manner. After 5 hours at 65% relative humidity (RH), the modified morphology factor DNA offers a prolonged practical use of about 3 hours compared to the DNA which has not been crystallized according to the new process (purified crude ): the kinetics of water intake is slowed down.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Medicinal Preparation (AREA)
• Peptides Or Proteins (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

Country Status (7)

Cited By (2)

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• 2005
  • 2005-04-12 FR FR0503618A patent/FR2884244B1/fr not_active Expired - Fee Related
• 2006
  • 2006-04-11 WO PCT/FR2006/050326 patent/WO2006108991A2/fr not_active Ceased
  • 2006-04-11 RU RU2007135718/15A patent/RU2379231C2/ru not_active IP Right Cessation
  • 2006-04-11 EP EP06726332.7A patent/EP1868940B1/fr not_active Not-in-force
  • 2006-04-11 JP JP2008505941A patent/JP5291455B2/ja not_active Expired - Fee Related
  • 2006-04-11 US US11/918,018 patent/US7789980B2/en not_active Expired - Fee Related
• 2007
  • 2007-10-09 NO NO20075094A patent/NO20075094L/no not_active Application Discontinuation

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