KR101766539B1 - PREPARATION METHOD FOR β-HMX PARTICLES - Google Patents

Abstract

The present invention relates to a method for producing beta-HMX (beta-HMX) particles, and more particularly, to a method for producing beta-HMX particles by dispersing beta-HMX particles at a constant concentration in a dispersion medium, HMX particles obtained by pulverizing β-HMX particles and seeding them into an organic solvent saturated with HMX, followed by cooling and recovering the precipitated β-HMX particles after a lapse of a predetermined time, and drying ≪ / RTI > According to the present invention, nano to submicron? -HMX particles having an average particle size of about 0.3 to 0.8 μm can be produced in a smooth surface state.

Description

PREPARATION METHOD FOR < RTI ID = 0.0 > β-HMX PARTICLES &

The present invention relates to a method for producing beta-HMX (beta-HMX) particles, and more particularly, to a method for preparing beta-HMX particles by dispersing beta-HMX particles in a dispersion medium The present invention relates to a method for producing β-HMX particles having excellent nano-to-submicron size with excellent pulverized productivity.

HMX (cyclotetramethylene tetranitramine) is a typical nitramine-based high-energy material and is a compound widely used in solid propellant compositions, including plastic bonded explosives (PBX). HMX is colorless crystals and there are five crystal forms such as α-HMX, β-HMX, γ-HMX, δ-HMX and ε-HMX. The highest density (ρ = 1.902 g / cm ³ ) in these crystals and the thermodynamically stable β-HMX with a monoclinic crystal system. However, due to the inherent sensitivity, studies are under way for long time dullness.

In the 1960s, during the Vietnam War, USS Oriskany and USS Forrestal, as well as the MK24, laser guided missiles, and many aircraft warships and ammunition loaded with ammunition, Strategies Non-intent External stimulant Causes of deflagration that do not react at all to the attack of heat, impact, shooting, storm wave, bullet or debris caused by sympathetic detonation, or avoid sudden explosion phenomenon Synthesis and composition of the present invention.

The insensitivity of a composition consisting predominantly of a desensitizing agent is determined by the physicochemical properties of the high-wise compound (e.g. stoichiometry, oxygen balance, average particle size, particle size distribution, shape, , Polymer binders, plasticizers, other additives, etc.). The insensitivity of high-molecular compounds can be achieved by controlling the external properties (particle size distribution and average particle size) of the individual particles and internal properties (for example, inclusions, impurities, heterophase presence, defect concentration, voids, etc.).

For example, when the average particle diameter of the high-molecular compound is small, there is an effect of reducing the crystal defect concentration contained in the crystal and a reaction site that can promote relatively hot spot generation due to decrease of vacancies. In addition, when the shape of the high-density compound is close to a polygonal or spherical shape, there is an advantage that the mechanical strength is improved, the external impact is uniformly dispersed on the particle surface,

And unintentional stimulation of high-level compounds into heat, impact, and surface contact, they can be quantified by slow or rapid heating, impact sensitivity, friction sensitivity, and shock sensitivity. have.

The shock sensitivity is a shock wave response characteristic of a high explosive, which is a shock wave amplification phenomenon caused by the chemical energy release of a high explosive, which causes ignition. What is deeply related to shock sensitivity in various physicochemical properties is the particle size and surface roughness of a high explosive and it is known to be an emulsion, a liquid explosive, a porous solid explosive it is observed that the shock sensitivity of a high energy composition such as a solid explosive and a plastic bonded explosive (PBX) varies depending on the particle size of a separately formed high explosive (see Non-Patent Document 1).

Nichols et al. Found that when the hot spot size of β-HMX particles decreases from 3 ㎛ to 0.6 ㎛, the reaction time of impact is about 36 times slower. It was also found that when the hot spot density was reduced to about 1/100, the attack time was 36 times slower. When the hot spot size increased from 0.2 ㎛ to 2 ㎛, the critical temperature of explosion due to impact decreased from 1162K to 985K. Therefore, β-HMX particles become insensitive as the particle size becomes smaller (see Non-Patent Document 1).

The average particle size of β-HMX particles for lowering the shock sensitivity and shock sensitivity is not known, but when the hot spot size and density are considered roughly, the size of the β-HMX particles should be about 1 μm or less do. FIG. 1 shows the correlation between the average particle diameter and the impact sensitivity of β-HMX particles reported in various literatures (see Non-Patent Documents 2 to 7). From the figure, the impact sensitivity is lowest at an average particle diameter of 1 μm or less.

The correlation between particle surface roughness and shock sensitivity or susceptibility to β-HMX is not known, but when compared to RDX with the same ring and similar -NO ₂ groups, Bellitto et al. show that the shock sensitivity of RDX is surface roughness (surface roughness). According to Czerki et al., The sensitivity of RDX particles to RDX particles having an average particle diameter of 10 to 30 탆 and RDX particles having an average particle diameter of 100 to 300 탆 are not correlated with internal voids, (See Non-Patent Documents 8 to 9). In the present invention, it is preferable that the particle density of the particles is in the range of 0.1 to 10 μm.

The energy due to the surface friction between the particle-particle or crystal-crystal is not dissipated but is concentrated on the corners or angled surface, but the smooth surface particles have a shock sensitivity that is rapidly dissipated by the friction energy accumulated by the inter- . In addition, when the shape of the particles is not angular, there is an advantage that the packing density of the high explosive powder is increased because the intergranular porosity is reduced. Therefore, the surface characteristics and the average particle size of β-HMX required to lower the shock sensitivity are comparatively smooth surface state and small particle size of 1 μm or less.

The first consideration in the production of β-HMX particles is the manufacturability of β-form crystalline forms. When the metastable γ-HMX particles are produced, they become stable β-HMX due to the crystal type transition (transfer from γ-HMX (or a-HMX) to β-HMX) and due to the volume change and transition heat generated by phase transition The filling density and the mechanical strength of the HMX particles, the energy composition cracking during storage or transport, the generation of fine powder and its aggregation, and the increase in sensitivity due to crystal growth. This results in fatal consequences in the utilization of the energy composition.

To date, the technique of clearly producing nano-sized to submicron sized β-HMX particles has been reported in supercritical fluid, grinding. The HMX particles produced by other techniques can not clearly identify the crystal form via Raman, IR, and XRD (see Non-Patent Documents 10 to 11).

The β-HMX particles formed by the supercritical fluid (SAS, RESS, etc.) have an average particle diameter of about 0.09 to 0.67 μm or less, and the shape is nearly spherical or irregular. Supercritical conditions are p = 68 ~ 272 atm and HMX concentration is 0.003 ~ 0.5 wt%.

In the case of pulverization, spherical particles with an average particle size of about 0.6 ㎛ were prepared. Under optimum process conditions, the grinding time was 4 hours, the HMX concentration was 10 wt%, and the agitation speed was 1000 rpm.

Briefly discussing the advantages and disadvantages of the β-HMX particle manufacturing technology, wet milling has a large amount of HMX to be treated, but the disintegration medium is easily lost by evaporation, so there is a possibility of ignition and the grinding time is long. Although highly spherical β-HMX particles are produced, intergranular agglomeration can occur due to the negative charge specific to nitramine-based materials, and internal stress accumulation occurs due to continuous surface grinding shock, resulting in unintentional explosion This is a concern. In the case of the supercritical system, it is possible to prepare submicron β-HMX particles without solvent recovery and waste generation. However, β-HMX concentration is very low to several mg level compared with solvent, and operates at high pressure and temperature. There are disadvantages.

A. L. Nichols, C. M. Tarver, A Statistical Hot Spot Reactive Flow Model for Shock Initiation and Detection of Solid High Explosives, UCRL-JC-145031, Lawrence Livermore National Laboratory, 2002. J. Kaur, VP Arya, G. Kaur, T. Raychaudhuri P. Lata., Evaluation of Ultrasonic Treatment for the Size Reduction of HNS and HMX in Comparison Solvent-Antisolvent Crystallization, Propellants, Explosives, Pyrotechnics, 37, 662-669, 2012. Y. Wang, W. Jiang, X. Song, G. Deng, F. Li, Insensitive HMX (Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) Nanocrystals Fabricated by High- Yield, Low-Cost Mechanical Milling, Central European Journal of Energetic Materials, 10, 277-287, 2013. J. Liu, W. Jiang, Q. Yang, J. Song, G. Hao, F. S. Li, Study of nano-nitramine Explosives: Preparation, Sensitivity and Application, Defense Technology, 10, 184-189, 2014. B. Risse, F. Schnell, D. Spitzer, Sythesis and Desensitization of Nano-β-HMX, Propellants, Explosives, Pyrotechnics, 35, 1-5, 2015. Z. Gao, J. Cai, B. Long, Z. Fan, Preparation of HMX Ultrafine Particles by Supercritical CO2 method, Chinese Journal of Explosives & Propellants, 31 (4), 22-26, 2008. Mongolia, Super HMX system and sensitivity study, Masanori, Nanjing R & D, 2013. V. Bellitto, M. I. Melnik, Atomic Force Microscopy-Imaging, Measuring and Manipulating Surfaces at Atomic Scale, Intech, 2012. H. Czerki, W. G. Proud, Relationship between the Morphology of Granular Cyclotrimethylene-trinitramine and Its Shock Sensitivity, Journal of Applied Physics, 102, 113515, 2007. Y. Wang, W. Jiang, X. Song, G. Deng, F. Li, Insensitive HMX (Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) Nanocrystals Fabricated by High- Yield, Low-Cost Mechanical Milling, Central European Journal of Energetic Materials, 10 (2), 277-287, 2013. Y. Bayat, S. M. Pourmortazavib, H. Iravania, H. Ahadia, Statistical Optimization of Supercritical Carbon Dioxide Antisolvent Process for Preparation of HMX Nanoparticles, Journal of Supercritical Fluids, 72, 248-254, 2012.

As described above, supercritical fluids and pulverization methods are currently available for the production of nano-sized or submicron-sized β-HMX that does not contain any other crystal form. Each of these techniques is characterized by the possibility of evaporation and ignition of the β-HMX dispersion medium, a decrease in productivity due to very low solubility, a high process temperature and pressure, an expensive device manufacturing cost, internal stress accumulation by surface grinding, there is a problem in that intergranular agglomeration occurs due to the negative charge peculiar to the nitramine-based material. Therefore, there is a demand for a method of producing nano to submicron [beta] -HMX particles in a smooth and comparatively mild condition as compared with the conventional methods.

Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a method for grinding a β-HMX particle by pulverizing the β-HMX particle in a dispersion medium and recovering the β-HMX particle in a seed form to a solution saturated with HMX to form an irregular surface And a method for producing β-HMX particles of nanometer to submicron size by avoiding stress accumulation due to the above-mentioned problems.

(A) dispersing β-HMX particles in a dispersion medium at a constant concentration (S210), (b) dispersing β-HMX particles in a (C) a step (S230) of recovering the β-HMX particles which have been pulverized in the step (b) by filtration and washing, (d) a step (d) of recovering β-HMX particles dispersed in the dispersion medium A step S28 of seeding a β-HMX particle solution in which β-HMX particles are dispersed, recovered in step (c), in a solution saturated with HMX (cyclotetramethylene tetranitramine) (e) cooling the mixed solution to a predetermined temperature and precipitating β-HMX particles after a predetermined time elapses (S250), and (f) filtering the β-HMX particles precipitated in the step (e) And a step S260 of recovering the water by washing.

Further, in the method for producing β-HMX particles, a step of adding a dispersant to the dispersion medium before the step (b), or a step of adding a dispersant to the mixed solution after the step (d) and before the step (e) As shown in FIG.

Specifically, as shown in FIG. 3, (a) dispersing beta-HMX (beta-form cyclotetramethylene tetranitramine) particles at a constant concentration (S310) in the dispersion medium, (b) adding a dispersant to the dispersion medium HMX particles dispersed in the dispersion medium in step (S330), (c) in step (S330), (b) a step (S330) of grinding the dispersed β-HMX particles through the step (b) (E) removing β-HMX particles from the β-HMX particles dispersed in the distilled water through the step (d), to a solution saturated with HMX (cyclotetramethylene tetranitramine) (F) cooling the mixed solution to precipitate β-HMX particles (S360) after a predetermined time has elapsed (S360), and (g) And recovering the β-HMX particles precipitated in the filtration step (S370) by filtration and washing to prepare β-HMX particles .

(A) dispersing beta-HMX (beta-form cyclotetramethylene tetranitramine) particles at a constant concentration in step (S410); (b) (C) after the step (b), recovering the pulverized? -HMX particles by filtration and washing (S430); (d) (c) a step (S440) of seeding a recovered β-HMX particle-dispersed solution of β-HMX particles in a solution saturated with HMX (step 440); (e) Adding a dispersant to the mixed solution (S450); (f) cooling the mixed solution to which the dispersant has been added through the step (e), and precipitating nano to submicron? -HMX particles after a predetermined time has elapsed (S460), and (g) recovering the β-HMX particles precipitated in the step (f) through filtration and washing (S470 ) Can be prepared to produce the? -HMX particles.

The β-HMX particles prepared according to the present invention are β-HMX particles having a size of nano to submicron.

Hereinafter, with reference to FIG. 2, the method for producing β-HMX particles of the present invention will be described in detail.

As shown in FIG. 2, step (a) S210 is a step of dispersing β-HMX particles in a dispersion medium at a constant concentration. The dispersion is carried out at a temperature of 15 to 25 ° C., It can also proceed well in containers of the type.

Also, in the step (a), the dispersion medium is a mixture containing at least one compound that is mixed with water (H ₂ O) or water (H ₂ O), wherein the compound to be mixed with the water (H ₂ O) At least one selected from the group consisting of methyl alcohol, ethyl alcohol, n-propanol, n-butanol, isopropanol and isobutanol .

Further, the mass ratio of the water (H ₂ O) compound with the water (H ₂ O) is mixed with a 1: 1 to 1:10 preferably in the range. Particularly, a range of 1: 2 to 1: 5 is more preferable.

If the mass ratio is out of the above range, the solubility of HMX may increase due to excessive mixing to lower the recovery of the β-HMX particles, and the dispersion of the β-HMX particles may be deteriorated to cause aggregation.

In the step (a), the concentration of the β-HMX particles is preferably in the range of 1 to 20 wt%. In particular, a range of 5 to 10 wt% is more preferable.

If the concentration exceeds the concentration range of the β-HMX particles, the yield of the β-HMX particles may be lowered or the average particle diameter of the β-HMX particles may rapidly increase.

In addition, the average particle diameter of the? -HMX particles dispersed in the step (a) is preferably in the range of 1 to 10,000 μm.

If the average particle size of the β-HMX particles is out of the range, coarse particles are generated due to the uniformalization during the grinding process of the β-HMX particles, so that the grinding time becomes long or the particle size distribution of the β-HMX particles becomes uneven It is preferable to satisfy the above range.

(b) Step S220 is a step of grinding the β-HMX particles dispersed in the dispersion medium. The β-HMX particles are pulverized into particles having a small particle size in the dispersion medium by a grinding ball, The material of the crusher is a metal oxide such as ZrO ₂ , Al ₂ O ₃ , SiO _2, and SiC. It is preferable that the diameter of the pulverizing sphere is in the range of 0.01 to 1.2 mm.

If the diameter of the crusher is out of the above range, a metal or a metal oxide derived from the crusher may remain in the β-HMX particles, which affects the aerobic characteristics, purity and storage performance of β-HMX. When the diameter of the crusher is less than the above range, the crushing time is long, and therefore, it is preferable to satisfy the above range.

In the step (b), the β-HMX particles may be pulverized in the dispersion medium by stirring the pulverized β-HMX particles together with the pulverizer at a stirring rate of 100 to 5000 rpm for 0.5 to 24 hours.

At this time, there is a problem that the average particle size of the β-HMX particles is 1 μm or more at a time when the milling time is shorter than the above range, and when the time is longer than the above range, .

If the stirring speed is slower than the above range, the particle size distribution may be widened due to uneven pulverization. If the stirring speed is out of the above range, Since there is no significant difference between the grinding time and the average particle diameter of the? -HMX particles in the production process, it is preferable that the above range is satisfied.

(c) Step (S230) is a step of recovering the pulverized β-HMX particles by filtration and washing. Preferably, the solution in which the β-HMX particles are suspended is hydrophilic PTFE (polytetrafluoroethylene) mm and a pore size of 0.1 [mu] m using a membrane filter to recover β-HMX particles.

The recovered β-HMX particles are washed with at least one solution selected from carbon tetrachloride, cyclohexane, hexane, ethyl ether and diethyl ether, It can be dried in a vacuum oven at 65 deg. C for 12 hours.

(d) Step S240 is a step of inoculating the recovered β-HMX particles into a HMX (cyclotetramethylene tetranitramine) saturated solution as seeds, wherein the HMX is saturated at a constant concentration in an organic solvent .

The organic solvent is acetone. Butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, At least one selected from the group consisting of N-methyl-2-pyrrolidone, acetonitrile, methyl alcohol and ethyl alcohol can be used.

The saturation of HMX can be carried out at a temperature range of 0 to 80 캜, preferably a temperature range of 20 to 40 캜. If the temperature is lower than the above range, it is difficult to supply sufficient supersaturation for the growth of the β-HMX particles, and if the temperature is higher than the above range, the average particle diameter of the β-HMX particles may become 1 μm or more due to excessive HMX dissolution.

In step (d) (S240), the amount of the β-HMX particle solution is preferably in the range of 0.1 to 1 g per 10 g of the HMX saturated solution. If the amount of the β-HMX particle solution is out of the range, secondary nucleation may not occur due to a very small amount of seed seeding, or grain growth may be uneven due to excessive seed seeding.

It is preferable that the mass ratio between the β-HMX particle solution and the HMX saturated solution is in the range of 1:10 to 1:20. When the mass ratio is out of this range, the β-HMX The average particle diameter of the particles can be increased.

(e) Step S250 is a step of cooling the solution inoculated with the β-HMX particles as seeds to precipitate β-HMX particles having a size of nano or submicron.

The cooling temperature is preferably in the range of 0 to 40 占 폚. If the temperature is out of the above temperature range, the rate of occurrence of supersaturation for the growth of the β-HMX particles is slow or coarse β-HMX particles are generated and the particle size distribution becomes uneven.

The cooling rate of the mixed solution is preferably in the range of 0.01 캜 / min to 5 캜 / min. If the cooling time is longer than the above range, the production of β-HMX particles decreases as the time required for cooling increases. When the cooling rate is increased, the nucleation temperature is lowered, and β-HMX particles having an average particle size of 1 μm or more can be produced.

After cooling, it is preferable to keep the solution for 10 to 180 minutes. There is a problem that the average particle diameter becomes 1 탆 or more or the yield of the β-HMX particles is lowered due to the continuous growth of the β-HMX particles.

On the other hand, as described above, a dispersant may be added to suppress the growth of the β-HMX particles in the mixed solution before the step (b) or after the step (d) and before the step (d) have.

The dispersant may be at least one selected from the group consisting of polyvinyl pyrrolidone (PVP), polyvinyl pyrrolidone (PVP) -co-poly (vinyl alcohol), polyvinyl alcohol ), Sodium dodecyl sulfonate (SDSA), sodium dodecyl benzene sulfonate (SDBS), polyoxyethylene sorbitan monolaurate (Tween 20), polyoxyethylene Polyoxyethylene sorbitan monopalmitate (Tween 40), polyoxyethylene sorbitan monostearte (Tween 60), polyoxyethylene sorbitan monooleate (Tween 80), sorbitan monostearate Polyacrylic acid, sorbitan monolaurate (span 20), starch, poly (acrylic acid), oleyl alcohol, poly (styrene-co-butyl acrylate), hexadecyl trimethylammonium bromide hexadecyltrimethylammonium bromide, alkylphenyl ethoxylate, oleylamine, poly (alkylene imine), poly (alkylene oxide), cellulose and dextrin and dextrin may be used.

The amount of the dispersant is preferably in the range of 10 to 100,000 ppm with respect to the? -HMX particles. If the amount of the dispersant is out of the range, the growth of the β-HMX particles may not be inhibited or the dispersant may remain in the β-HMX particles.

(f) Step S260 is a step of cooling and collecting the recovered β-HMX particles after a certain time has elapsed. The solution in which the β-HMX particles are precipitated through the step (e) The same method can be used to recover β-HMX particles by filtration and washing using a hydrophilic PTFE (polytetrafluoroethylene) material with a membrane filter having a diameter of 47 mm and a pore size of 0.1 μm have.

The recovered β-HMX particles are further washed and dried by recovering the pulverized β-HMX particles through filtration and washing, or recovering the precipitated β-HMX particles through filtration and washing. , A solution of at least one selected from the group consisting of carbon tetrachloride, cyclohexane, hexane, ethyl ether and diethyl ether, It can be dried for 12 hours.

As described above, unlike the conventional supercritical carbon dioxide method, it does not require high temperature or high pressure, and it is a method of producing β-HMX particles having no surface stress accumulation due to rough surfaces and surface grinding such as wet grinding, Unlike the method, β-HMX particles can be produced in large quantities by avoiding the aggregation state and recovered as non-aggregated monolithic particles.

The present invention relates to a process for producing β-HMX particles having high productivity and excellent insensitivity. The β-HMX particles have an average particle size of 0.3 to 0.8 μm and a particle size of nano to submicron -HMX particles can be produced. Therefore, it is possible to produce β-HMX particles which are relatively insensitive due to maximization of the bursting pressure due to an increase in packing density and decrease in the concentration of internal defects.

Therefore, the nano to submicron sized β-HMX particles prepared from the present invention can be widely used as civil and military compositions such as composite energetic materials, high explosives and solid composite propellants.

1 is a log-log graph between impact sensitivity (H ₅₀ (cm)) and average particle diameter (d _avg ) of β-HMX particles reported in prior art documents.
FIGS. 2 to 4 are flowcharts of a method for producing β-HMX particles according to an embodiment of the present invention.
FIG. 5 is a graph showing the average particle size change of β-HMX particles according to the grinding time in Example 1 of the present invention. FIG.
6 is a scanning electron micrograph of β-HMX particles according to the grinding time in Example 1 of the present invention.
7 is an X-ray diffraction curve of the β-HMX particles obtained in Example 1 of the present invention.
8 is a scanning electron micrograph of the? -HMX particles prepared in Example 1 according to the elapsed time.
9 is a graph showing the average particle diameters of the? -HMX particles prepared in Example 1 and Example 2 according to elapsed time.
10 is a scanning electron micrograph of γ-HMX particles prepared in Comparative Example 1 of the present invention.
11 is an X-ray diffraction curve of γ-HMX particles prepared in Comparative Example 1 of the present invention.

As used herein, the terms "comprising," " comprising, "or" added, "and the like should not be construed as necessarily including the various elements or steps described in the specification above, Elements, or steps, but may also include additional elements or steps.

The following examples and comparative examples are provided for the purpose of further illustrating the present invention but are not to be construed to limit the scope of the present invention. Those skilled in the art may be embodied in many different forms.

In Example 1, the? -HMX particles dispersed in the dispersion medium in the above-described production method of? -HMX particles were pulverized by a ball milling method and then the pulverized? -HMX particles were recovered by filtration and washing .

Specifically, 300 g of β-HMX particles having an average particle size of about 2.34 μm at a temperature of 25 ° C. were dispersed in a solution containing 2.5 L of distilled water and 0.5 L of isopropanol as a dispersion medium. Crushing balls having a diameter of 0.1 mm ZrO ₂ are put in the same mass ratio as the β-HMX particles, followed by ball milling. At this time, the crusher rotation speed was set to 3000 rpm. After the pulverization, the solution in which the β-HMX particles were suspended was filtered with a membrane filter having a diameter of 47 mm and a pore size of 0.1 μm using a hydrophilic polytetrafluoroethylene (PTFE) to obtain β-HMX particles Was recovered. The recovered β-HMX particles were washed with hexane and dried in a vacuum oven at 65 ° C. for 12 hours.

5 to 7 are SEM micrographs and X-ray diffraction diagrams of β-HMX particles according to Example 1, respectively.

As shown in FIG. 5, when the crushing time was 10 minutes, 20 minutes, 30 minutes, 40 minutes and 50 minutes, the average particle diameter of the β-HMX particles was 0.9 μm, 0.63 μm, 0.35 μm and 0.37 μm, As a result, the average particle size decreased. 6 is a scanning electron microscope (SEM) photograph of? -HMX particles according to the pulverization time. The shape of the β-HMX particles is generally elliptical.

FIG. 7 is an X-ray diffractogram of β-HMX particles prepared according to Example 1 and compared with data of JCPDS (Joint Committee on Powder Diffraction Standards).

The relative intensities of the crystalline form of β-HMX (JCPDS 42-1768) at 2θ of 14.72 °, 16.04 °, 20.56 °, 23.06 °, 26.2 °, 29.68 ° and 31.94 ° were 100, 22, 35, 31, 55, and 53, respectively. Compared with such JCPDS data, the crystal form of the HMX particles recovered in Example 1 of the present invention is? -HMX.

In Example 2, β-HMX particles having an average particle diameter of about 0.37 μm obtained in Example 1 are used as seeds, and β-HMX particle solutions in which about 0.5 g of species are dispersed in about 10 g of distilled water are prepared . 50 mL of a solution saturated with HMX (cyclotetramethylene tetranitramine) in an organic solvent at 40 ° C. was cooled to 10 ° C. at 1 ° C. per minute. After about 10 minutes, about 5 g of the β-HMX particle solution prepared above was introduced and β -HMX < / RTI > The precipitated β-HMX particles were filtered with a membrane filter made of hydrophilic PTFE (polytetrafluoroethylene) having a diameter of 47 mm and a pore size of 0.1 μm, and β-HMX particles were recovered. The recovered β-HMX particles were washed three times with hexane and dried in a vacuum oven at 65 ° C. for 12 hours.

8 is a scanning electron microscope (SEM) photograph of the β-HMX particles prepared in Example 2 according to elapsed time.

In Example 3, β-HMX particles were prepared in the same manner as in Example 2, except that poly (vinyl pyrrolidone) (PVP) was added as a dispersant to a mixed solution mixed with an HMX saturated solution .

In Example 4, β-HMX particles were prepared in the same manner as in Example 2, except that the cooling temperature of the mixed solution mixed with the HMX saturated solution was changed from 20 ° C. to 10 ° C.

FIG. 9 is a graph showing changes in average particle diameter of the? -HMX particles prepared in Examples 2 to 4 according to elapsed time. As shown, the growth of beta-HMX particles was inhibited when PVP was added as a dispersant. Further, it can be confirmed that the results similar to those of the third embodiment are obtained when the cooling temperature is changed as in the fourth embodiment.

In Comparative Example 1, 1 kg of? -HMX was dissolved in acetone at 50 占 폚, and 10 kg of distilled water was separately prepared at 20 占 폚. The acetone solution in which the β-HMX was dissolved was sprayed to distilled water at a pressure of 8 bar. Immediately after nozzle injection, HMX particles were precipitated. The solution in which the HMX particles were suspended was a hydrophilic PTFE (polytetrafluoroethylene) having a diameter of 47 mm and was filtered with a membrane filter having a pore size of 0.1 탆 to recover HMX particles. The HMX particles were recovered from hexane, ≪ / RTI > The particles were dried in a vacuum oven at 65 DEG C for 12 hours.

FIG. 10 is a scanning electron microscope (SEM) photograph of the HMX particles prepared in Comparative Example 1. FIG.

11 is an X-ray diffractogram of the HMX particles prepared in Comparative Example 1 and was compared with data of JCPDS (Joint Committee on Powder Diffraction Standards).

When the crystal form is? -HMX (JCPDS 44-1621), 2? Is 13.94 °, 14.04 °, 14.55 °, 16.92 °, 19.84 °, 20.22 °, 20.33 °, 21.74 °, 23.07 °, 23.17 °, 23.84 °, 24.85 ° Relative intensities at 100, 24.96, 25.53, 26.57, 26.91, 27.33, 27.43, 27.92, 27.93, 28.02, 28.09, 28.34, 28.38, , 100, 80, 88, 42, 26, 26, 24, 50, 49, 45, 22, 22, 52, 27, 20 29, 35, 21, 21, 32, 32, 37, When compared with the JCPDS data, the HMX particles prepared in Comparative Example 1 are gamma-HMX particles.

Table 1 below shows the results of the BAM fall hammer test to determine whether explosion and decomposition reactions can occur by impact on HMX particles obtained according to Examples 1 to 3 and Comparative Example 1, It is impact sensitivity. "Impact sensitivity" is the impact energy obtained by the BAM fall hammer test.

HMX sample Average particle diameter (占 퐉) Crystal form Impact energy (J) Example 1 2.36 beta 7.66 Example 2 0.45 beta 11.38 Example 3 0.85 beta 17.30 Comparative Example 1 0.72 gamma 8.95

As shown in Table 1, the impact energy of the? -HMX particles obtained in Example 3 was the highest and the most insensitive.

As described above, the? -HMX particles according to this embodiment are prepared by dispersing? -HMX particles in a dispersion medium at a constant concentration and then pulverizing the? -HMX particles to obtain β-HMX particles, seeding them in an organic solvent saturated with HMX, The β-HMX particles prepared by the method of recovering β-HMX particles after filtration and washing after a certain period of time after cooling are smooth and have an average particle size of about 0.3 to 0.8 μm and not more than 1 μm Nano to sub-micron. The impact energy according to the BAM fall hammer test was insensitive to less than 17.30 J and satisfied the conditions of very stable storage and storage. Also, due to the reduction of the particle size, a large specific surface area was obtained, It can be dramatically accelerated.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, The scope of the present invention is not limited thereto. It will be apparent to those skilled in the art that various changes, substitutions, and alterations can be made hereto without departing from the spirit of the present invention, and it is obvious that those parts easily changeable by those skilled in the art are also included in the scope of the present invention.

Claims (20)

delete (a) dispersing β-HMX (beta-form cyclotetramethylene tetranitramine) particles in a dispersion medium at a constant concentration;
(b) adding a dispersant to the dispersion medium;
(c) pulverizing the? -HMX particles dispersed in the dispersion medium through the step (b);
(d) recovering the pulverized? -HMX particles through filtration and washing through the step (c);
(e) The β-HMX particle solution in which β-HMX particles were collected by the above step (d) was inoculated into HMX saturated solution, which is an organic solvent saturated with HMX (cyclotetramethylene tetranitramine) Preparing a solution;
(f) cooling the mixed solution and precipitating? -HMX particles after a lapse of a predetermined time; And
(g) recovering the β-HMX particles precipitated in the step (f) by filtration and washing,
Wherein the dispersion medium is at least one selected from the group consisting of ethyl alcohol, n-propanol, n-butanol, isopropanol, and isobutanol, : 1 to 1: 10,
The organic solvent may be at least one selected from the group consisting of gamma-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, N, N-dimethylformamide, wherein the solvent is at least one selected from dimethylformamide, N-methyl-2-pyrrolidone, acetonitrile, methyl alcohol and ethyl alcohol. -HMX particle manufacturing method. (a) dispersing β-HMX (beta-form cyclotetramethylene tetranitramine) particles in a dispersion medium at a constant concentration;
(b) pulverizing the? -HMX particles dispersed in the dispersion medium through the step (a);
(c) recovering the pulverized β-HMX particles through filtration and washing through the step (b);
(d) The β-HMX particle solution in which β-HMX particles are dispersed is recovered by adding the purified β-HMX particle solution to the HMX saturated solution, which is an organic solvent saturated with HMX (cyclotetramethylene tetranitramine) Preparing a solution;
(e) adding a dispersant to the mixed solution;
(f) cooling the mixed solution to which the dispersing agent has been added through the step (e), and precipitating the β-HMX particles after a lapse of a predetermined time; And
(g) recovering the β-HMX particles precipitated in the step (f) by filtration and washing,
Wherein the dispersion medium is at least one selected from the group consisting of ethyl alcohol, n-propanol, n-butanol, isopropanol, and isobutanol, : 1 to 1: 10,
The organic solvent may be at least one selected from the group consisting of gamma-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, N, N-dimethylformamide, wherein the solvent is at least one selected from dimethylformamide, N-methyl-2-pyrrolidone, acetonitrile, methyl alcohol and ethyl alcohol. -HMX particle manufacturing method. The method according to claim 2 or 3,
Wherein the β-HMX particles have an average particle diameter of 1 μm to 10,000 μm in the step (a). The method according to claim 2 or 3,
Wherein the concentration of the β-HMX particles in the step (a) is 1 to 20 wt%. delete delete The method according to claim 2 or 3,
Wherein the pulverization is carried out by a pulverizer and the material of the pulverizer comprises at least one selected from ZrO ₂ , Al ₂ O ₃ , SiO ₂ and SiC, and the diameter of the pulverizer is 0.01 mm to 1.2 mm -HMX particle manufacturing method. 9. The method of claim 8,
Wherein the β-HMX particles are pulverized in the dispersion medium by stirring the β-HMX particles dispersed through the step (a) with the grinder at a speed of 100 to 5000 rpm for 0.5 to 24 hours, ≪ / RTI > delete The method according to claim 2 or 3,
Wherein the HMX saturated solution is saturated with the HMX in the organic solvent at 0 to 80 占 폚. The method according to claim 2 or 3,
Wherein the amount of β-HMX particles seeded into 10 g of the HMX saturated solution is in the range of 0.1 to 1 g. The method according to claim 2 or 3,
Wherein the mixed solution is cooled to 0 to 40 占 폚. The method according to claim 2 or 3,
Wherein the cooling rate of the mixed solution is 0.01 占 폚 / min to 5 占 폚 / min. The method according to claim 2 or 3,
Wherein the mass ratio between the β-HMX particle solution and the HMX saturated solution is in the range of 1:10 to 1:20. The method according to claim 2 or 3,
Wherein the mixed solution is cooled and the time elapsed thereafter is 10 to 180 minutes. The method according to claim 2 or 3,
The dispersant may be at least one selected from the group consisting of polyvinyl pyrrolidone (PVP), polyvinyl pyrrolidone (PVP) -co-poly (vinyl alcohol), polyvinyl alcohol ), Sodium dodecyl sulfonate (SDSA), sodium dodecyl benzene sulfonate (SDBS), polyoxyethylene sorbitan monolaurate (Tween 20), polyoxyethylene Polyoxyethylene sorbitan monopalmitate (Tween 40), polyoxyethylene sorbitan monostearte (Tween 60), polyoxyethylene sorbitan monooleate (Tween 80), sorbitan monostearate Polyacrylic acid, sorbitan monolaurate (span 20), starch, poly (acrylic acid), oleyl alcohol, poly (styrene-co-butyl acrylate), hexadecyl trimethylammonium bromide hexadecyltrimethylammonium bromide, alkylphenyl ethoxylate, oleylamine, poly (alkylene imine), poly (alkylene oxide), cellulose and dextrin (dextrin). < / RTI > The method according to claim 2 or 3,
Wherein the concentration of the dispersant is 10 to 100,000 ppm with respect to the? -HMX particles. The method according to claim 2 or 3,
The step of recovering the pulverized β-HMX particles through filtration and washing, or the step of recovering the recovered β-HMX particles through filtration and washing, followed by washing and drying the recovered β-HMX particles ≪ / RTI > 20. The method of claim 19,
In the washing and drying step, the β-HMX particles may be at least one selected from the group consisting of carbon tetrachloride, cyclohexane, hexane, ethyl ether, and diethyl ether. Wherein the solution is washed with a solution.

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