JP6220769B2 - Production method of carbon particles by detonation method - Google Patents

Description

  The present invention relates to a method for producing carbon particles by a detonation method. More specifically, the present invention relates to a method for producing carbon particles containing diamond and graphitic carbon by a detonation method using a material containing at least an explosive substance.

  Nanoscale diamonds (also called nanodiamonds) have many excellent properties such as high hardness and extremely low coefficient of friction, so they have already been used in various fields, and as a very promising new material, Application development is under consideration.

  It is known that nanodiamonds can be synthesized using, for example, detonation reaction of explosives. In this synthesis method, detonation is performed only with the explosive raw material that is a carbon source, and carbon atoms decomposed and released from the molecules constituting the explosive raw material by detonation reaction are generated as diamond at high temperature and high pressure at the time of detonation. It is generally called the detonation method. See, for example, Non-Patent Document 1 for the production of nanodiamonds by the detonation method.

  Conventionally, nano-diamond production by the detonation method has been performed in Eastern European countries such as Russia and Ukraine, the United States, China, and the like. In these countries, as explosive raw materials for carbon sources, military waste explosives can be obtained at low cost. Therefore, trinitrotoluene is used alone, or trinitrotoluene and trimethylenetrinitroamine (RDX, hexogen) are used. Or cyclotetramethylenetetranitramine (HMX, also called octogen) has been used in combination.

  The demand for nanodiamonds is expected to increase in the future with the development of applications. However, the production using military waste explosives is limited. Therefore, there is a possibility that the supply will be insufficient in the international market in the future. Thus, domestic production is expected, but the above-described conventional method has a problem that it cannot be economically profitable because nanodiamonds cannot be produced with high yield.

  Thus, various proposals have been made to improve the yield of nanodiamonds. For example, Patent Document 1 proposes a method in which an iron cylindrical container containing an explosive substance is detonated while suspended in water. Patent Document 2 proposes a method in which an explosive substance is detonated in a state where the explosive substance is contained in a bag made of a hydrocarbon polymer via a coolant. Further, Patent Document 3 proposes a method in which an explosive substance is detonated in a state of being accommodated in a container formed of ice.

  However, in the method described in Patent Document 1, a large amount of iron scrap is contained in the residue of the detonation reaction, and much labor is required for refining the carbon particles. Moreover, since iron acts as an oxidation catalyst for diamond, the yield of nanodiamond is greatly reduced. In fact, the yield of nanodiamond is about 1-5%. Moreover, the finally obtained nanodiamond contains impurities of iron, and the quality may deteriorate. In the method described in Patent Document 2, carbon particles can be purified relatively easily, but the effect of improving the yield of nanodiamonds is insufficient and still remains at about 5%. In the method described in Patent Document 3, it is necessary to use a container formed of ice having a larger size than an iron container or a hydrocarbon polymer bag body in order to rapidly cool the product of the detonation reaction. There is. Accordingly, a large refrigeration facility is required, and the running cost may be high. In addition, since a container formed of ice gradually melts under normal conditions, preparation for detonation reaction must be urgently involved, and there are time constraints. Moreover, the yield of nanodiamonds is certainly slightly improved compared to the methods described in Patent Documents 1 and 2, but is still only about 7%.

JP-A-3-271109 JP 2007-269576 A JP 2012-135718 A

Yozo Kakubuchi (Author), “2.3 Dynamic high pressure (detonation method)”, Diamond Industry Association (ed.), “Diamond Technology Overview”, NG, January 2007, pp. 28-33

  In view of the above situation, the present inventors have conducted various studies in order to develop a method for producing high-quality nanodiamonds with high yield and high productivity by the detonation method. As a result, it has been found that nanodiamonds can be obtained in high yield even when detonation is carried out in a state where explosive substances are contained in a container formed of an acrylic resin.

  A container made of an acrylic resin is used as a container for storing explosive substances. Acrylic resin is widely used as a resin for forming a general container, or an organic substance is used as a material for forming a container. This is because, if an acrylic resin is used, it is thought that most of it is burnt and decomposed by the detonation reaction and becomes a carbon source to improve the yield of nanodiamond. However, even if an acrylic resin container is used, the debris reaction residue contains a lot of debris, and as with the iron container, it has a lot of effort to refine the carbon particles. I understood. In addition, it was also found that the yield of nanodiamond was still lower than that in the case of using a container formed of ice, and remained at about 5%. Therefore, it is necessary to develop a method capable of increasing the productivity and reducing the yield of nanodiamond by reducing the debris of the container contained in the residue of the detonation reaction as much as possible.

  The present invention solves this problem, and an object of the present invention is to provide a method for producing carbon particles containing diamond and graphitic carbon by a detonation method using a material containing at least an explosive substance. More specifically, an object of the present invention is to provide a method for producing high-quality carbon particles and thus diamond with high yield and high productivity.

  In producing carbon particles containing diamond and graphitic carbon by a detonation method using a raw material containing at least an explosive substance, the present inventors have accommodated the raw material in a container formed of a specific material. As a result, it was found that carbon particles with good quality and thus diamond can be obtained with high yield and high productivity as compared with the conventional method described above, and the present invention has been completed.

  In the present specification, the explosive means a substance capable of performing a detonation reaction. Both explosive materials and non-explosive materials are included in explosives. An explosive substance means a substance that causes a rapid combustion reaction. Explosive substances are generally roughly classified into solid explosives that do not have fluidity at room temperature and normal pressure, and liquid explosives that have fluidity. In this specification, unless otherwise specified, one or both of a solid explosive and a liquid explosive are meant.

  In this specification, “including at least an explosive substance” means that at least an explosive substance is required to cause a detonation reaction. In general, explosive substances and raw material are used in the method of producing carbon particles by the detonation method. At this time, the explosive substance may also serve as the raw material, or the raw material may be used separately from the explosive substance. In the following, a case where a raw material is used separately from an explosive material will be described unless otherwise specified. In the case where the explosive substance also serves as the raw material, the raw material in the following explanation shall be read as explosive as necessary.

  When the explosive substance detonates, the raw material is decomposed to the atomic level, and free carbon atoms are aggregated in a solid state without being oxidized to generate diamond or graphitic carbon. At the time of detonation, the raw material is brought into a high temperature and high pressure state due to a decomposition reaction, but immediately expands and is cooled. The process from high temperature and high pressure to vacuum cooling occurs in a much shorter time than normal combustion or deflagration, which is an explosion phenomenon slower than detonation. Carbon particles are produced.

  The present invention is a method for producing carbon particles by a detonation method, comprising a step of containing a raw material containing at least an explosive substance in a container and detonating the explosive substance, wherein the container includes a nitrate ester, A container formed of a material containing at least one selected from the group consisting of a nitro compound and an azide is used.

  In the production method of the present invention, as the container, nitrocellulose, nitromethane, nitroethane, nitrate esterified cyclodextrin polymer, glycidyl azide polymer, nitrate esterified hydroxy-terminated polybutadiene, poly (3,3-nitratomethyl) methyloxetane and nitrate esterification It is preferable to use a container formed of a material containing at least one selected from the group consisting of polyglycidyl. It is particularly preferred to use a container formed from a material containing nitrocellulose, such as celluloid.

  In the production method of the present invention, detonation is performed in a state where a raw material containing at least an explosive substance is contained in a container. At this time, if a container formed of the specific material described above is used, the material constituting the container becomes part of the carbon atoms constituting the carbon particles in the detonation reaction, or carbon dioxide gas or nitrogen gas. Since it changes to gas such as water vapor and dissipates, the debris of the container contained in the residue of the detonation reaction can be extremely reduced. Therefore, the carbon particles can be easily separated and purified from the residue of the detonation reaction, and as a result, the quality and productivity of the carbon particles and diamond are improved. Moreover, the ratio in the mass ratio which can collect | recover carbon particles from the carbon in a raw material substance improves, and the ratio in the mass ratio which can collect | recover diamond from the carbon in a raw material substance by extension improves. In the present specification, a ratio in a mass ratio at which carbon particles can be recovered from carbon in the raw material is referred to as “carbon particle yield” which is a mass ratio of the carbon particles to the raw material. In addition, a ratio in a mass ratio at which diamond can be recovered from carbon in the raw material is referred to as “diamond yield” which is a mass ratio of diamond to the raw material.

  The production method of the present invention can further include a step of recovering carbon particles from the residue obtained in the detonation step. In the recovery step, for example, if classification and purification treatment is performed, carbon particles can be obtained in the form of powder having a desired particle size. Moreover, the manufacturing method of this invention can further include the process of isolate | separating a diamond from the carbon particle obtained at the collection | recovery process. In the separation step, for example, if a purification treatment is performed, the graphitic carbon can be removed from the carbon particles to obtain diamond. These classification treatments and purification treatments may be appropriately combined in each step as necessary, or may be repeated an appropriate number of times.

  According to the production method of the present invention, carbon particles having good quality including diamond and graphitic carbon, and thus diamond can be obtained with high yield and high productivity by detonation.

It is sectional drawing which shows typically an example of the explosion apparatus used for the manufacturing method of this invention.

  The production method of the present invention is a method of producing carbon particles by a detonation method, including a step of containing a raw material containing at least an explosive substance in a container and detonating the explosive substance, A container formed of a material containing at least one selected from the group consisting of a nitrate ester, a nitro compound and an azide is used.

  In the production method of the present invention, first, a raw material containing at least an explosive substance is placed in a container. As a container, the container formed from the material containing at least 1 sort (s) selected from the group which consists of nitrate ester, a nitro compound, and an azide is used. The organic compound forming the container generally becomes part of the carbon atoms constituting the carbon particles in the detonation reaction, or changes into a gas such as carbon dioxide gas, nitrogen gas, water vapor, and is dissipated. The debris of the container contained in the residue of the detonation reaction can be extremely reduced.

  Among the materials constituting the container, examples of the nitrate ester include nitrocellulose, nitrated cyclodextrin polymer, nitrated hydroxy-terminated polybutadiene, poly (3,3-nitratomethyl) methyloxetane, and nitrated polyglycidyl nitrate. It is done. Examples of the nitro compound include nitromethane and nitroethane. Examples of the azide include glycidyl azide polymer. These polymers are commonly referred to as “energetic polymers” and are, for example, polymers used to mold composite propellants. For details, see, for example, “High Energy Materials”, “Propellants, Explosives and Pyrotechnics”, Chapter 4 Propellants, Section 4.9 Ingredients of Solid Rocket Propellants, Wiley-VCH Verlag GmbH & Co. KGaA (2010). Since nitromethane and nitroethane are liquids at room temperature and normal pressure, for example, they may be used as a solidified product molded from a thermoplastic resin such as an acrylic resin. Nitrocellulose may be used as, for example, a so-called celluloid solid solution composed of about 75% nitrocellulose and about 25% camphor. Of these materials, celluloid is particularly preferred because it is readily available and inexpensive.

  In the production method of the present invention, when the explosive substance also serves as the raw material, the raw material means only the explosive substance, whereas when the raw material is used separately from the explosive substance, the raw material Means explosive and raw material. The raw material is an explosive material or a non-explosive material that is a carbon source for the detonation method. The explosive substance is a substance that causes detonation and becomes a carbon source itself, or a substance that causes a stable detonation in order to generate carbon particles from a raw material. In addition, when the molecule | numerator which comprises an explosive substance contains a carbon atom, the said explosive substance may become a carbon source with a raw material substance.

  In the production method of the present invention, the explosive substance is not particularly limited. For example, trinitrotoluene (also referred to as TNT), cyclotrimethylenetrinitroamine (RDX, also referred to as hexogen), cyclotetramethylenetetra Solid explosives such as nitramine (HMX, also called octogen), pentaerythritol tetranitrate (also called PETN), tetranitromethylaniline (also called tetryl); a mixture of hydrazine and hydrazine nitrate, a mixture of hydrazine and ammonium nitrate, hydrazine and nitrate Liquid explosives such as a mixture of hydrazine and ammonium nitrate, nitromethane, and a mixture of hydrazine and nitromethane. As used herein, hydrazine includes its hydrate, hydrazine hydrate. These explosive substances may be used alone or in combination of two or more.

  Among the explosive substances, solid explosives can be used as a raw material. Therefore, when an explosive substance also serves as a raw material, a solid explosive may be used alone. In addition, when a raw material is used separately from an explosive substance, two or more kinds of solid explosives may be used in combination, or one or more kinds of solid explosives and a liquid explosive may be used in combination. In any case, it is important to select the explosive material so that the explosion speed of the explosive material is higher than that of the raw material. The explosion speed is a propagation speed of detonation when an explosive substance causes detonation, and is measured by a Dortrish method, an ion gap method, an optical fiber method, or the like. See LASL Explosive Properties Date, ed. Gibbs, T.R. and Propolato, A., University of California Press, Berkeley, Los Angels, London, 1980 for explosive speeds defined in the present invention. Table 1 shows the explosive speed of typical explosive substances. The explosive materials in Table 1 indicate materials that can be detonated stably.

  When using a raw material separately from the explosive substance, the amount of the explosive substance and the raw material used may be appropriately adjusted according to the desired amount of carbon particles, and is not particularly limited. The ratio represented by the raw material is mass ratio, preferably 0.1 or more, more preferably 0.2 or more, preferably 1 or less, more preferably 0.9 or less, and still more preferably 0. .8 or less. If the ratio of the amount used is less than 0.1, a detonation reaction sufficient to generate carbon particles cannot be performed, and thus the yield may decrease. Conversely, if the ratio of the amount used exceeds 1, explosive substances are used more than necessary, which may increase production costs.

  Hereinafter, an embodiment for carrying out the manufacturing method of the present invention will be described in detail with reference to the drawings. Here, a case where a raw material is used separately from an explosive substance will be described. However, when an explosive substance also serves as a raw material, the raw material in the following description is replaced with an explosive substance as necessary. FIG. 1 is a cross-sectional view schematically showing an example of an explosion device used in the production method of the present invention. The explosive device shown in FIG. 1 is merely illustrative and is not intended to limit the present invention.

  First, the raw material 10 and the explosive substance 12 are accommodated in the container 20. Hereinafter, a container that stores the raw material 10 and the explosive substance 12 is referred to as an “explosion container”. The material forming the explosion container 20 is as described above. The dimensions and shape of the explosion container 20 may be appropriately set according to the desired amount of carbon particles, and are not particularly limited. However, the shape of the explosion container 20 is particularly preferably a cylindrical container because a stable detonation reaction can be performed to achieve a high yield of carbon particles. The explosion container 20 does not necessarily have to be provided with a lid, but is preferably provided with a lid in order to attach and hold an explosive agent or detonator for detonating explosive substances. As the explosion container, a commercially available container formed from a specific material may be used, or the explosion container may be produced by itself using the specific material. The method for producing the explosion container is not particularly limited. In the detonation reaction, the production method of the present invention is an explosion formed from a material that becomes part of the carbon atoms constituting the carbon particles or changes into a gas such as carbon dioxide, nitrogen, or water vapor. It is because it has the characteristics in using a container. That is, if an explosion container formed of such a specific material is used, the effect of the present invention can be achieved without depending on the manufacturing method.

  In the explosion container 20, the explosive substance 12 is disposed around the raw material substance 10. When the explosive substance 12 is arranged around the raw material substance 10, the high temperature and high pressure accompanying the shock wave generated by the detonation of the explosive substance 12 is applied to the raw material substance 10 as uniformly as possible, that is, in an explosive shape. It is preferable to arrange the source material 10 and the explosive material 12 symmetrically so as to ensure symmetry. Therefore, for example, when both the raw material 10 and the explosive substance 12 are solid, the raw material 10 and the explosive substance 12 are concentrically formed by, for example, melting and compressing them in a cylindrical split mold. A columnar molded body is produced, and the molded body may be installed in a cylindrical container with the axial direction aligned. When the raw material 10 is solid and the explosive material 12 is a liquid explosive, the raw material 10 is melted and pressed to produce a cylindrical molded body, and the molded body is formed into a cylindrical shape. After arranging the axial direction in the center of the inside of the container, liquid explosives may be injected around it. Or after inject | pouring a liquid explosive into a cylindrical container, you may install the said molded object by aligning an axial direction in the inner center part of the said container. When the raw material 10 is liquid and the explosive substance 12 is solid, the explosive substance 12 is melted and pressed to produce a concentric hollow columnar shaped body, and the shaped body is cylindrical. It is only necessary to inject the raw material 10 into the hollow part of the container after the axial direction is aligned in the container.

  In the manufacturing method of the present invention, the explosive substance 12 is then detonated to generate carbon particles from the raw material substance 10. A shock wave generated by the detonation reaction of the explosive substance 12 propagates toward the raw material 10, and the shock wave is compressed by the shock wave to cause detonation, and the carbon decomposed and released from the organic molecules constituting the raw material 10. Atoms change to carbon particles containing diamond and graphitic carbon.

  Detonation may be performed in either an open system or a closed system. In order to perform detonation in an open system, for example, detonation may be performed inside earth or a tunnel excavated underground. However, it is preferable to perform detonation in a closed system because the residue can be prevented from scattering over a wide range. In order to perform detonation in a closed system, detonation may be performed in a state where an explosion container is loaded in, for example, a chamber. Hereinafter, a chamber used for detonation is referred to as an “explosion chamber”. The explosion chamber may be made of metal or concrete as long as it has sufficient strength to withstand detonation. It is preferable to suspend and load the explosion container in the explosion chamber.

  When detonation is performed in an explosion chamber, if the atmosphere in the explosion chamber does not substantially contain oxygen during detonation, the oxidation reaction of carbon can be suppressed. Can be improved. In order to obtain such an atmosphere, the atmosphere in the explosion chamber is replaced with an inert gas such as nitrogen gas, argon gas, carbon dioxide gas, or evacuated to about −0.1 to −0.01 MPaG. Alternatively, after evacuating and releasing the atmosphere (oxygen) from the explosion chamber, an inert gas may be injected into the explosion chamber to a weak positive pressure of about +0.000 to +0.001 MPaG. In this specification, the symbol G attached after the pressure unit means a gauge pressure.

  Moreover, it is preferable to dispose a coolant around the explosion vessel in the explosion chamber because the generated diamond can be rapidly cooled to prevent the phase transition to graphite carbon. In order to arrange the coolant in this manner, for example, the explosion container 20 may be installed in the cooling container 30 and the coolant 32 may be injected into the gap between the cooling container 30 and the explosion container 20. At this time, if the coolant 32 is a substance that does not substantially generate an oxidizing substance such as oxygen or ozone, the oxidation reaction can be suppressed, so that the yield of carbon particles is improved. In order to obtain this coolant, for example, oxygen gas dissolved in the coolant 32 may be removed, or a coolant 32 that does not contain a constituent element that generates an oxidizing substance such as oxygen or ozone may be used. Examples of the coolant 32 include water, alkyl halides such as chlorofluorocarbons and carbon tetrachloride. Water is particularly preferred because it has little adverse effect on the environment.

  The explosive substance 12 is normally detonated using a detonator or a detonation wire. In order to cause detonation more reliably, an explosive agent may be interposed between the explosive substance 12 and the detonator or explosive wire. Examples of the explosive charge include Composition C-4 and SEP manufactured by Asahi Kasei Chemicals. In this case, after attaching the explosive charge 22 and the detonator or explosive wire 24 to the explosion container 20, for example, it is loaded into the explosion chamber. When the coolant 32 is used, it is preferable to store the explosion container 20 in a liquid-tight container so that the coolant 32 does not enter the explosion container 20, for example. Examples of the liquid-tight container include bags made of olefin-based synthetic resins such as polyethylene and polypropylene as raw materials. If the explosive substance 12 is detonated and detonated after setting in this way, carbon particles containing diamond and graphitic carbon can be obtained as the residue.

  In the production method of the present invention, the residue obtained in the detonation process may include debris of an explosion container, or detonation debris such as conductors / wires as impurities. In such a case, it is preferable to provide a step of removing rubble from the residue obtained in the detonation step and collecting the carbon particles. In this recovery step, for example, if classification and purification treatment is performed, the carbon particles can be obtained in the form of a dry powder having a desired particle size.

  Typically, first, coarse rubble is removed from the obtained residue, followed by classification with a sieve or the like, and a sieve passing part and a residue on the sieve are separated, and the sieve passing part is recovered. The residue on the sieve is classified again after crushing. Water is separated from the finally obtained sieve passage to obtain a dry powder. At this time, the sieve openings may be adjusted as appropriate, separation and purification treatments may be repeated, and the sieve passage having a sieve opening corresponding to the desired particle size may be used as the product.

  More specifically, for example, when detonation is performed in the explosion chamber using water as the coolant 32, water containing the residue is collected from the explosion chamber and separated by settling. Then, after removing coarse rubble from the sediment, the supernatant liquid is recovered as a waste liquid, and the sediment is classified with a sieve or the like to obtain a sieve passage. Since some of the generated carbon particles may adhere to the rubble, the residue on the sieve is crushed and separated by ultrasonic vibration or the like, and classified again with a sieve or the like. Usually, the residue on the sieve of about 30 μm is often the debris of the explosion container 20 or blasting debris such as conductors / wires. Therefore, it is disposed of as industrial waste after collection, and the part of the sieve that passes about 30 μm is collected as a product. It is preferable to do. Alternatively, a sieve having a smaller particle size can be collected as a product using a sieve having a smaller opening than 30 μm. The recovered product is obtained by separating the water by centrifugation or the like and drying it to obtain a powder of carbon particles having a desired particle size.

  Depending on the application, the obtained carbon particle powder can be further purified. For example, the organic component adhering to the carbon particles is removed using an organic solvent such as acetone. Moreover, the metal component mixed in the carbon particles is removed using an inorganic acid such as nitric acid. Each treatment condition may be appropriately adjusted according to the concentration of the organic solvent or inorganic acid used, and is not particularly limited. Specifically, the acetone treatment is performed at a normal temperature to 60 ° C. for about 4 to 8 hours using, for example, about 8 to 12 times the amount of acetone as a mass ratio. The most preferable acetone treatment is performed at about 50 ° C. for about 6 hours using about 10 times the amount of acetone by mass. The nitric acid treatment is performed, for example, at about 90 to 120 ° C. for about 5 to 30 minutes using about 4 to 10 times the amount of nitric acid as the mass ratio. The most preferable nitric acid treatment is performed at a treatment temperature of about 100 to 110 ° C. for about 15 minutes using concentrated nitric acid (specific gravity 1.38) of about 6 to 7 times the sample by mass. The treated product is obtained by separating the water by centrifugation or the like and drying it to obtain a powder of purified carbon particles having a desired particle size.

  In the production method of the present invention, diamond can also be produced from the obtained carbon particles. In such a case, it is preferable to provide a step of separating diamond from the carbon particles obtained in the recovery step. In this separation step, for example, if a purification treatment is performed, it is possible to remove the graphitic carbon from the carbon particles and obtain diamond. The purification process includes a process of removing graphitic carbon using an inorganic acid such as perchloric acid. The treatment conditions may be appropriately adjusted according to the concentration of the inorganic acid used, and are not particularly limited. Specifically, the perchloric acid treatment is performed at about 180 to 220 ° C. for about 5 to 30 minutes using, for example, about 18 to 22 times the amount of perchloric acid as the mass ratio. The most preferable perchloric acid treatment is carried out at about 190 to 210 ° C. for about 10 to 15 minutes using about 20 times the amount of perchloric acid (concentration 60%) as a mass ratio.

  The carbon particles obtained by the production method of the present invention contain diamond and graphitic carbon. Therefore, even if it remains as it is or after any post-treatment, if the graphitic carbon remains sufficiently, the excellent characteristics of diamond and graphitic carbon can be utilized. Useful for various applications. For example, making use of diamond's excellent properties such as abrasiveness, durability, and wear resistance, such as tools, antiwear agents, lubricants, fluidized whetstones, fixed whetstones, plating / coating, durable films, lithium battery parts, etc. Useful for applications. Also, taking advantage of the superior properties of graphite carbon such as conductivity, water repellency and biocompatibility, fiber materials, resin coatings that provide functionality, drug delivery systems, electronic device covers, battery electrode materials, electrical conductivity It is useful for applications such as adhesive film, reinforced rubber / water-repellent rubber, catalyst and adsorbent. Further, for example, the carbon particles may be subjected to perchloric acid treatment and / or plasma oxidation treatment to remove graphitic carbon. In this case, taking advantage of the excellent properties of diamond such as high refraction, transparency, and durability, it is particularly useful for use in optical parts such as optical lenses.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. It is also possible to carry out and they are all included in the technical scope of the present invention.

  First, a method for evaluating the carbon particles of the present invention will be described.

<Mass method (weight method)>
First, the sample is treated at 50 ° C. for 6 hours with 10 times the mass of acetone (made by Wako Pure Chemicals, special grade). By this treatment, organic components contained in the sample are dissolved in acetone and removed. Next, the residue is collected by sedimentation separation, washed with water and dried, and then the mass is measured, whereby the organic component can be quantified from the difference in mass between the sample and the residue after acetone treatment.

  The residue after the acetone treatment is treated at a temperature of 100 to 110 ° C. for 15 minutes using 6 to 7 times as much concentrated nitric acid (manufactured by Wako Pure Chemical, specific gravity 1.38, special grade). By this treatment, the metal component contained in the sample is dissolved in nitric acid and removed. Next, the residue is recovered by sedimentation separation, washed with water, dried, and then the mass is measured to obtain the recovered amount of carbon particles. The yield of the carbon particles is calculated as a percentage of the recovered amount of the carbon particles with respect to the mass of the raw material substance and the explosive substance. In addition, when the explosive substance does not contain a carbon atom, the mass is not considered in the calculation of the yield. Moreover, a metal component can be quantified from the mass difference between the residue after the acetone treatment and the residue after the nitric acid treatment.

  The residue after the nitric acid treatment is treated at 190 to 210 ° C. for 10 to 15 minutes using 20 times the amount of perchloric acid (manufactured by Wako Pure Chemicals, concentration 60%, special grade) by mass ratio. By the treatment, graphitic carbon contained in the carbon particles is oxidized and removed by perchloric acid. Subsequently, the residue is recovered by sedimentation separation, washed with water, dried, and then the mass is measured to obtain the recovered amount of diamond. The yield of diamond is calculated as a percentage of the recovered amount of diamond with respect to the mass of the raw material and explosive material. In addition, when the explosive substance does not contain a carbon atom, the mass is not considered in the calculation of the yield. In addition, graphitic carbon can be quantified from the difference in mass between the residue after nitric acid treatment and the residue after perchloric acid treatment.

  Next, an example in which carbon particles were produced using a container formed from a specific material by the production method of the present invention, and a comparative example in which carbon particles were produced from a container formed from other materials Will be described.

Example 1
In this example, carbon particles were produced by a detonation method using an explosion vessel made of celluloid.

  First, two celluloid plates having a thickness of 1 mm were overlapped and wound around a previously produced wooden cylinder to form a cylinder having an inner diameter of 12 cm and a height of 20 cm. Separately, an adhesive in which celluloid was dissolved in acetone was used to adhere a cylindrical seam to prevent the contents from leaking from the adhesive surface and foreign matter from entering from the outside. A lid on which two identical celluloid plates were superposed on one end of the cylinder was adhered with the same adhesive to close the bottom. A removable cover in which two identical celluloid plates were overlapped was attached to the other end of the cylinder. A nozzle for attaching and fixing a detonator such as a detonator was provided at the center of the lid.

In this example, TNT was used as a raw material separately from the hydrazine liquid explosive which is an explosive substance. TNT used was a cylindrical molded body (manufactured by Chuka Kayaku). The mass of the TNT molded body was 2.52 kg, and the density was 1.60 g / cm ³ . Further, hydrazine nitrate and hydrazine hydrate were mixed at a mass ratio of 3: 1 to prepare 0.93 kg of a hydrazine-based liquid explosive.

Next, detonation reaction was performed using an explosion device as shown in FIG. The molded body as the raw material 10 was placed in the center of the explosion container 20, and the liquid explosive as the explosive substance 12 was filled therearound. An explosive 22 (SEP), explosive wire, and No. 6 electric detonator 24 were attached to the top of the explosion container 20, covered, and stored in a liquid-tight polyethylene bag. A container having a capacity of 200 L was used as the cooling container 30. The explosion container 20 was installed in the cooling container 30. At this time, the outer bottom surface of the explosion container 20 was adjusted to be 29.5 cm in height from the inner bottom surface of the cooling container 30 by using the iron mount 34 and the iron perforated disk 36. And distilled water was put into the cooling container 30 as the cooling material 32, and the cooling material 32 was filled in the gap between the cooling container 30 and the explosion container 20. A polyethylene bag containing distilled water was placed on top of the cooling vessel. A total of 200 L of distilled water was used. After the cooling container 30 was covered, it was suspended from the ceiling in an explosion chamber with an internal volume of 30 m ³ using a wire sling. The inside of the explosion chamber was evacuated from atmospheric pressure, and the amount of remaining oxygen gas was calculated to be about 25.5 g.

  After setting in this way, the explosive material 12 was detonated by detonating the explosive wire with the detonator. Then, about 200 L of water containing the residue was recovered from the explosion chamber and settled and separated to remove coarse rubble. At this time, since the supernatant liquid was strongly alkaline, the pH was adjusted to weak acidity by adding citric acid. The supernatant liquid that became weakly acidic was recovered as a waste liquid as it was. The precipitate was classified with a sieve having an opening of 100 μm / 16 μm using a vibrating sieve device (“KG-700-2W” manufactured by KOWA). The portion passing through the 16 μm sieve was recovered as it was. The residue on the sieve is crushed for about 5 minutes with an ultrasonic vibrator ("4G-250-3-TSA" manufactured by Crest), and the carbon content is separated from the rubble surface. -700-2W "), and classified again with a sieve having an opening of 100 µm / 32 µm / 16 µm, and the sieve passage was collected. In addition, each sieve passage part was left to stand for 24 hours in a 80 degreeC drying machine ("OF-450S" made from ASONE), and it was set as the dry powder, after evaporating a water | moisture content.

  Thus, a total of 492.5 g of carbon particles was obtained as 104.5 g for the 16 μm sieve passage, 243.9 g for the 32 μm sieve passage and 144.1 g for the 100 μm sieve passage. Among these, the carbon particles were evaluated by the above-mentioned weight method for the portion passing through the 16 μm sieve and the portion passing through the 32 μm sieve. Table 2 below shows the experimental contents, the total recovered amount and yield of carbon particles, and the total recovered amount and yield of diamond in this experimental example.

<< Example 2 >>
In this example, an explosion vessel made of celluloid having an inner diameter of 12 cm and a height of 50 cm produced in the same manner as in Example 1 was used. As a raw material, TNT (industrial grade) was filled and the diameter was 10 cm and height. Using a TNT molded body with a mass of 6.30 kg and a density of 1.59 g / cm ³ molded into a 48 cm cylinder, and changing the amount of explosive hydrazine liquid explosive from 0.93 kg to 2.17 kg Example 1 except that the outer bottom surface of the explosion vessel was adjusted to be 15 cm high from the inner bottom surface of the cooling vessel, and the amount of distilled water used as the coolant was changed from 200 L to 220 L. In the same manner as above, carbon particles of 257.4 g of a 16 μm sieve passage, 531.8 g of a 32 μm sieve passage and 336.4 g of a 100 μm sieve passage were obtained. The total recovered amount of carbon particles was 1125.6 g. Table 2 below shows the experimental contents, the total recovered amount and yield of carbon particles, and the total recovered amount and yield of diamond in this example.

≪Comparative example 1≫
In this comparative example, carbon particles containing diamond and graphitic carbon were produced by an explosion method using an explosion container made of acrylic resin.

  First, a cylinder having an inner diameter of 12 cm and a height of 57 cm was cut out from an acrylic cast pipe having an outer diameter of 13 cm and a wall thickness of 5 mm. At one end of the cylinder, an acrylic plate having a thickness of 10 mm was used as a lid, and the bottom was closed by bonding with an adhesive. An acrylic plate having a thickness of 3 mm was attached to the other end of the cylinder as a detachable lid. At the center of the lid, a nozzle that can be fitted with a detonator was bonded so that a detonator or other detonator could be fixed at the center of the lid.

In this comparative example, TNT was used as a raw material, separately from the hydrazine liquid explosive which is an explosive substance. TNT used was a cylindrical molded body (manufactured by Chuka Kayaku). The mass of the TNT molded body was 6.50 kg, and the density was 1.58 g / cm ³ . Also, hydrazine nitrate and hydrazine hydrate were mixed at a mass ratio of 3: 1 to prepare 2.50 kg of hydrazine liquid explosive.

Next, detonation reaction was performed using an explosion device as shown in FIG. Specifically, the celluloid explosion container was changed to an acrylic resin explosion container, the 200 L cooling container was changed to a 99.5 L cooling container, and the outer bottom surface of the explosion container was inside the cooling container. It was adjusted to be located at a height of 22.5 cm from the bottom, the amount of distilled water used as a coolant was changed from 200 L to 99.5 L, and an explosion chamber with an internal volume of 30 m ³ was set to an internal volume of 26.5 m ³ Except that it was changed to the explosion chamber of, carbon particles having a passage of 1383.0 g of 16 μm sieve, 769.0 g of passage of 32 μm sieve and 919.9 g of passage of 100 μm sieve were obtained in the same manner as in Example 1. The total recovered amount of carbon particles was 3071.9 g. The experimental contents, the total recovery amount and yield of carbon particles, and the total recovery amount and yield of diamond are shown in Table 2 below.

  As shown in Table 2, when the celluloid container is used, the yield of diamond is similar to the case of using the acrylic resin container, although the yield of carbon particles is similar. It has improved. In addition, when a celluloid container is used, the yield of diamond is higher than when an iron container is used (Patent Document 1) or when a hydrocarbon polymer bag is used (Patent Document 2). Moreover, compared with the case where the container formed with ice is used (patent document 3), the comparable yield is ensured.

  Furthermore, when celluloid containers were used, the debris of the explosion container was extremely small, so the residue of the detonation reaction was black and the amount was small, so it was very easy to separate and purify the carbon particles. . On the other hand, when an acrylic resin container is used, the debris of the detonation reaction is white and large in quantity because it contains a large amount of debris from the explosion container. It required a lot of effort. Further, when the celluloid container was used, the proportion of the organic component was considerably smaller than when the acrylic resin container was used, and the subsequent purification treatment, particularly the acetone treatment, was very easy. As described above, the fact that the debris of the explosion container is small and the ratio of the organic component is small greatly improves the quality of the carbon particles and thus the diamond, and greatly contributes to the improvement of the productivity. In addition, when a celluloid container is used, the running cost is lower and there are no time restrictions compared to the case of using a container formed of ice (Patent Document 3), so productivity can be improved. Can be planned.

  Therefore, according to the production method of the present invention, it is easy to separate and purify carbon particles and diamond from the detonation residue, and finally, high-quality carbon particles and, consequently, diamond can be produced in high yield. It turns out that it can be obtained well.

  According to the production method of the present invention, a high-quality diamond can be produced with high yield and high productivity by the detonation method. Therefore, the production method of the present invention makes a great contribution in various fields related to applications utilizing the excellent characteristics of graphitic carbon and diamond.

10 Raw material 12 Explosive material 20 Explosive vessel 22 Explosive agent 24 Detonator and detonator 30 Cooling vessel 32 Coolant 34 Mounting base 36 Holed disc

Claims (5)

  A method for producing carbon particles by a detonation method, comprising a step of containing a raw material containing at least an explosive substance in a container and detonating the explosive substance, wherein the container includes a nitrate ester, a nitro compound and an azide. A production method using a container formed of a material containing at least one selected from the group consisting of chemical compounds.   The container is selected from the group consisting of nitrocellulose, nitromethane, nitroethane, nitrated cyclodextrin polymer, glycidyl azide polymer, nitrated hydroxy-terminated polybutadiene, poly (3,3-nitratomethyl) methyloxetane and nitrated polyglycidyl nitrate. The manufacturing method of Claim 1 using the container formed from the material containing at least 1 sort (s) made.   The manufacturing method of Claim 1 or 2 using the container formed from the material containing a nitrocellulose as the said container.   The manufacturing method of any one of Claims 1-3 further including the process of collect | recovering carbon particles from the residue obtained at the said detonation process.   The manufacturing method of Claim 4 which further includes the process of isolate | separating a diamond from the carbon particle obtained at the said collection | recovery process.