JP2009155153A - Porous gunpowder and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a granular porous gunpowder having a high rate of gas evolution in combustion and a method for producing the same. <P>SOLUTION: The method for producing the granular porous gunpowder includes a step of preparing a lacquer comprising a gunpowder component, an organic solvent and a nitrate and/or a sulfate, a step of preparing a granulation aqueous solution having specific gravity (20°C) of 1.0-1.1, and a heating step wherein the lacquer is added to the granulation aqueous solution and the granulation aqueous solution is heated under stirring to a temperature exceeding a boiling point of the organic solvent. The porous gunpowder has tentative specific gravity of 0.5-0.9 g/cm<SP>3</SP>. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a granular porous explosive that can be used as a propellant for a firearm such as a rifle and a method for producing the same.

  There is a demand for an explosive (propellant or propellant) used for a firearm or the like to increase the gas generation rate during combustion. In order to increase the gas generation rate, there is a method of increasing the combustion surface area, and a slicing method and a porous method are known. Since the slicing method has a limit in increasing the combustion surface area, a porous method is desirable to increase the combustion surface area.

  As a method for making explosives porous, a molding method using a drawing method has been conventionally used. However, in the drawing method, a material extruded from a base is cut into an arbitrary length (or thickness). In order to produce a propellant by (cutting), the molded body produced by the drawing method has burrs (indeterminate projections) on the surface such as the cut surface and the cut end, so that the fluidity is lowered. There is a problem that an error occurs in the weighing such as when the container is bulky and filled into a predetermined container.

  Patent Document 1 discloses a method for producing a small explosive composition by charging a lacquer mixed solution composed of nitrocellulose lacquer, ethyl acetate, a stabilizer, and a polymer flocculant into an aqueous solution and heating the mixture. Are listed. However, there is no description about making it porous.

  Patent Document 2 describes that a propellant having a temporary specific gravity of 0.2 or less and a foamed spherical or porous cylindrical shape is used, but there is no description of a production method.

  Patent Document 3 describes nitrified cotton-based hollow particles having an average particle diameter of 5 to 200 μm and an apparent specific gravity of 0.001 to 0.4 g / cc. However, the apparent specific gravity is too small, and it is not suitable as a propellant for firearms.

Patent Document 4 describes a method for producing a powdered explosive composition, but there is no description about making it porous.
Japanese Patent Publication No. 61-37239 Japanese Patent Publication No. 3-81078 Japanese Patent Laid-Open No. 3-7733 JP 2002-179491 A

  An object of the present invention is to provide a granular porous explosive that has good fluidity, can increase the combustion surface area, and can increase the gas generation rate, and a method for producing the same.

The present invention provides the following inventions as means for solving the problems.
1. Preparing a lacquer containing an explosive component, an organic solvent, nitrate and / or sulfate;
A step of preparing a granulated aqueous solution having a specific gravity (20 ° C.) of 1.0 to 1.1,
After adding the lacquer to the granulated aqueous solution, the temperature-raising step of raising the temperature of the granulated aqueous solution to a temperature exceeding the boiling point of the organic solvent while stirring.
A method for producing a granular porous explosive.
In the temperature raising step, the granulated aqueous solution may be further heated to 85 ° C. or higher (up to about 85 to 95 ° C.) to further reduce the organic solvent and moisture in the porous explosive.
2. Furthermore, the manufacturing method of the porous explosive of Claim 1 which has a pressing process which makes a porous explosive flat by a rolling means. A granular porous explosive may be rolled with water, and a rolling roll etc. may be used as a rolling means.
3. Furthermore, the manufacturing method of the porous explosive of Claim 1 which has the surface process which coat | covers the surface of a porous explosive with a coating agent.
4). The method for producing a porous explosive according to any one of claims 1 to 3, wherein the organic solvent is a combination of a good solvent and a poor solvent for the explosive component.
5. The manufacturing method of the porous explosive of any one of Claims 1-4 whose content of the nitrate contained in the said lacquer and / or sulfate is 1-70 mass parts with respect to 100 mass parts of explosive components.
6). The manufacturing method of the porous explosive of any one of Claims 1-5 whose specific gravity (20 degreeC) of the said granulated aqueous solution is 1.005 to 1.05.
7). A porous explosive having a temporary specific gravity of 0.5 to 0.9 g / cm3 determined by the following measurement method, which is obtained by the production method of the present invention.

(Measurement method of provisional specific gravity)
One end is closed and the other end opening glass-made cylindrical vessel (inner diameter 65.8Mm, height 155.9Mm, volume 530 cm ^3), the said quantity of explosive when poured gunpowder amount satisfying the cylindrical container (G) is measured, and the ratio of the explosive amount (g) to the volume (cm ³ ) of the cylindrical container is determined as a temporary specific gravity (g / cm ³ ).
8). The porous explosive whose gas generation rate (DP / DT) of the said porous explosive is 150-500 bar / msec.
(Measurement method of the gas generation rate)
MIL-STD-286C METHOD 801.1.2 According to the test method described in QUICKNESS AND FORCEMEASURMENT OF PROPELLANT. However, a closed container with a capacity of 200 cm ³ was used so that the loading density of the explosive was 0.05, the pressure in the closed container when 10 g of granular explosive was burned was measured, and the gas generation rate (DP / DT) is an average value of five values at pressures 0.3, 0.4, 0.5, 0.6, and 0.7 times the maximum pressure.
9. A porous explosive in which the porous explosive is a rifle propellant.

  Since the method for producing a porous explosive according to the present invention can process granulation and porosification in one step, the productivity is higher than the drawing method. In addition, the propellant particles obtained by the production method of the present invention have good fluidity because there are no surface burrs or the like generated during cutting, and are porous and have an increased combustion surface area. The speed has been increased.

  Although the manufacturing method of this invention is demonstrated for every process, the order of each process is not restrict | limited. Moreover, in the manufacturing method of this invention, one process can also be divided into two or more, and two or more processes can also be made into one.

  First, a lacquer containing an explosive component, an organic solvent, nitrate and / or sulfate is prepared in the first step. The explosive component used in this step is a known component described in Patent Documents 1 to 4 and the like, and includes a plasticizer, a stabilizer, an oxidizing agent, a binder, and the like as necessary in addition to the explosive. In addition, in the explosive component, the content of nitrocellulose is the largest and is preferably 50% by mass or more, and the explosive component can be appropriately selected according to the purpose of use.

  The organic solvent can dissolve the explosive component and has a boiling point of less than 100 ° C., and can be used, for example, one or a combination of two or more selected from ethyl acetate, butyl acetate, methyl ethyl ketone, acetone and the like. When two or more organic solvents are used in combination, it is desirable to use a combination of solvents having similar boiling points.

  Moreover, the said organic solvent can use what differs in the solubility with respect to a nitrocellulose according to the shape of a propellant. For example, if an organic solvent (good solvent) having a high solubility in nitrocellulose is used, the propellant particles are likely to be spherical, and if an organic solvent (poor solvent) having a low solubility is used, it is difficult to be spherical. As the good solvent, ethyl acetate, butyl acetate, methyl ethyl ketone, acetone and the like can be used, and those having low solubility in water are preferable. As the poor solvent, alcohols such as ethyl alcohol and isopropyl alcohol can be used.

  In the production method of the present invention, the above-mentioned good solvent and poor solvent are preferably used in combination as the organic solvent, and a combination of ethyl acetate and ethyl alcohol is preferred. By using a poor solvent in combination, the lacquer contains nitrocellulose undissolved components (cellulose component and the like), and it becomes easy to maintain the porosity of the lacquer (or explosive) in the porous formation process (temperature raising step). The ratio (volume ratio) when combining the good solvent and the poor solvent can be appropriately selected according to the explosive component. For example, the weight ratio of the poor solvent / good solvent is preferably 100/10 to 100/100, and preferably 100/30 to 100/70 is more preferable. When the weight ratio of the poor solvent increases, the amount of undissolved components in the lacquer increases, and the surface of the resulting porous explosive tends to be uneven.

  100-1000 mass parts is preferable with respect to 100 mass parts of explosives components, and, as for the quantity of the organic solvent contained in a lacquer, 200-400 mass parts is more preferable.

  Nitrate and / or sulfate is a component that dissolves in the granulated aqueous solution and becomes an auxiliary agent for making the propellant particles porous, and examples thereof include potassium nitrate, sodium nitrate, barium nitrate, and potassium sulfate.

  The content of nitrate and / or sulfate contained in the lacquer is preferably 1 to 70 parts by mass, more preferably 5 to 50 parts by mass, and still more preferably 10 to 30 parts by mass with respect to 100 parts by mass of the explosive component. By setting it as the above range, the target porous state (such as provisional specific gravity) can be adjusted.

  In the next step, a granulated aqueous solution having a specific gravity (20 ° C.) of 1.0 to 1.1 is prepared. This step may be performed before the lacquer preparation step or in parallel with the lacquer preparation step.

  The granulated aqueous solution is made to have a specific gravity range by adding a specific gravity adjusting agent to water or water, and the specific gravity (20 ° C.) is more preferably from 1.005 to 1.05, still more preferably 1. 005 to 1.02. The smaller the specific gravity, the more easily the porous explosives become porous, but the more difficult it becomes to be spherical, and the larger the specific gravity, the more likely to become spherical, but it becomes difficult to become porous.

  Specific gravity adjusting agents include inorganic salts such as potassium nitrate, sodium sulfate, and calcium carbonate.

  Further, by adding a protective colloid such as starch, gum arabic or carboxymethylcellulose to the granulated aqueous solution, the granular propellant can be stably dispersed in the granulated aqueous solution. The addition amount of the protective colloid is preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of water.

  The granulated aqueous solution is prepared by adding a specific gravity adjusting agent and a protective colloid agent to water and then heating and stirring as necessary. In addition, after preparation, before adding lacquer, it adjusts to normal temperature-about 50 degreeC.

  In the granulated aqueous solution, a good solvent of the organic solvent used in the lacquer may be added in an amount corresponding to the solubility of the good solvent in the granulated aqueous solution. As a result, it is possible to suppress the good solvent near the lacquer surface from eluting into the granulated aqueous solution, and to reduce the roughness (small irregularities) on the surface of the obtained granular porous explosive.

  In the next step, after adding the lacquer to the granulated aqueous solution, the granulated aqueous solution is gradually heated while being stirred, preferably up to about 85 ° C, more preferably up to about 90 ° C, and even more preferably about 95 ° C. Raise the temperature to near.

  The ratio of the granulated aqueous solution to the lacquer is preferably such that the lacquer is 0.5 to 0.6 parts by mass with respect to 100 parts by mass of the granulated aqueous solution.

  The stirring speed of the granulated aqueous solution in the heating step may be a speed at which the lacquer is uniformly dispersed in the granulated aqueous solution.

  The temperature increase rate of the granulated aqueous solution in the temperature increasing step affects the evaporation of the organic solvent contained in the lacquer and the solidification of the lacquer accompanying the evaporation of the organic solvent, and the shape of the propellant to be granulated (spherical) Affects the porous state. In the vicinity of the boiling point of the organic solvent contained in the lacquer, if the rate of temperature rise is slow, it tends to be spherical but difficult to become porous, and if the rate of temperature rise is fast, it tends to become porous but difficult to be spherical.

  The temperature increase rate can be controlled in one stage or multiple stages in consideration of the influence. For example, in the temperature raising step, the first stage in which the lacquer is dispersed in a granular form from the stirring start temperature, the second stage from the first stage to the vicinity of the boiling temperature of the organic solvent contained in the lacquer (boiling point or about ± 2 ° C. from the boiling point). The temperature rising rate may be different in each stage, divided into a stage, a third stage from the second stage to around 85 ° C., and a fourth stage from the third stage to around 95 ° C. However, it may be the same level.

  The first stage is a temperature range from the initial stirring temperature to a temperature at which the organic solvent contained in the lacquer does not vaporize (for example, a temperature of about −10 ° C. from the boiling point of the organic solvent). The temperature can be increased at a temperature increase rate of about min. The second stage and the third stage are a temperature range around the boiling point temperature of the organic solvent contained in the lacquer, and the temperature is gradually raised, preferably 3 to 15 ° C./min, more preferably 5 to 10 The temperature is raised at ° C / min.

  The fourth step is a step of further removing the organic solvent and moisture in the porous explosive, and the temperature is preferably raised at 5 to 15 ° C./min, more preferably at 5 to 10 ° C./min.

  By such agitation and temperature increase, the lacquer is dispersed in a granular form, and nitrate and sulfate are eluted in the granulated aqueous solution from the dispersion process of the lacquer or the dispersed granular lacquer, and the organic solvent is further volatilized and removed. Therefore, the lacquer in a dispersed state is solidified by forming pores therein and becomes a granular porous explosive.

  In addition, by appropriately controlling the temperature rising state as described above, it becomes easy to form a granular and porous explosive having a smooth surface, no burrs, etc., and a spherical or elliptical cross section and a shape similar thereto.

  Further, by finally raising the temperature to 95 ° C., the concentration of the remaining organic solvent can be reduced to about 0.1% by mass. If the residual concentration of the organic solvent is too high, the gas generation rate of the porous explosive may be reduced, which is not preferable.

Thereafter, the granular porous explosive produced in the granulated aqueous solution is taken out and dried by blowing cold air or hot air. In the production method of the present invention, if necessary,
(1) sieving process to equalize the granular porous powder
(2) A crushing process in which a granular porous powder is flattened by applying pressure through a rolling roll together with water,
(3) By adhering or impregnating the surface of a granular porous explosive or a porous explosive collapsed with a combustion inhibitor (for example, dinitrotoluene, dibutylphthalate, camphor, diphenylamine, ethyl central or a mixture thereof) , Surface process to reduce the burning rate at the beginning of ignition,
(4) A flame extinguishing treatment process for attaching potassium nitrate to the surface of granular gunpowder or a porous gunpowder that has been collapsed so that the combustion gas generated from the muzzle during combustion does not re-burn,
(5) Antistatic treatment (fluidity improving treatment) process in which graphite is sprayed on the surface of the granular porous explosive and rubbed together.
These steps can be added.

  In the present invention, the granular porous explosive obtained in the temperature raising step is subjected to a pressing treatment in the pressing step, thereby forming a flat porous gunpowder to increase the gas generation rate. The gas generation rate can be adjusted by performing the surface treatment in the process. Note that the order of the crushing step and the surface step is not limited, and only the surface step may be provided without providing the surface step, or only the surface step may be provided without providing the surface step. .

  The porous explosive obtained by the production method of the present invention has a circular or elliptical cross section and a shape similar to them, and has an average particle size of 300 to 1000 μm, preferably 400 to 600 μm. Then, it may be a flat shape.

  The flat shape has a thickness to thickness ratio of 1/10 to 10/10, preferably 2/10 to 4/10. The porous explosive has, for example, a thickness of 0.1 to 0.8 mm, preferably 0.2 to 0.4 mm, and an average length of 0.5 to 1.5 mm, preferably 0.6 to 1. 0 mm.

The porous explosive obtained by the production method of the present invention has a temporary specific gravity of 0.5 to 0.9 g / cm ³ , preferably 0.6 to 0.8 g / cm ³ , and a gas generation rate (DP / DT) is 150 to 500 bar / msec, preferably 200 to 460 bar / msec.

  The porous explosive obtained by the production method of the present invention is particularly suitably used as a rifle propellant (propellant particle).

(1) Average particle size (μm)
The particle size (outside dimension) of the granular explosive (propellant particles) was measured with a micrometer, and the average particle size (μm) was obtained by arithmetically averaging the particle sizes of the 20 granular explosives.

(2) Temporary specific gravity (g / cm ³ )
A cylindrical powder container (inner diameter: 65.8 mm, height: about 155.93 mm, volume: 530 cm ³ ) with one end closed and the other end opened is filled with granular powder (propellant particles) that fills the cylinder container. The amount (g) of the explosive at the time of pouring was measured, and the ratio of the amount (g) of the explosive to the volume (cm ³ ) of the cylindrical container was obtained as a temporary specific gravity.

(3) Appearance and internal structure The appearance and cross section of the granular explosive (propellant particles) were enlarged and observed using an SEM, and the photograph was taken. This evaluated the external appearance (shape and surface state) and internal structure (porous state with or without pores) of the granular explosive.

(4) Thickness (mm) and outer diameter (mm)
About 20 pressed granular powders, the thickness (length) with respect to the thickness (outer diameter) was measured with calipers, and the average value (mm) of each was determined.

(5) Gas generation rate (DP / DT)
MIL-STD-286C METHOD 801.1.2 Measured by the test method shown in QUICKNESS AND FORCEMEASURMENT OF PROPELLANT. However, a sealed container having a volume of 200 cm ³ was used so that the loading density was 0.05, and the pressure in the sealed container when 10 g of granular explosive (propellant particles) was burned was measured. The gas generation rate (DP / DT) was an average value of five values at pressures 0.3, 0.4, 0.5, 0.6, and 0.7 times the maximum pressure.

Examples 1-8, Comparative Example 1
(Lacquer preparation process)
Each component having the composition shown in Table 1 was put in a dissolver and dissolved at room temperature for 5 hours to obtain a lacquer. The explosive component is 100% by mass in total in terms of mass%, and the other is mass part indication for 100 parts by mass of explosive.

(Preparation of granulated aqueous solution)
After adding sodium sulfate in an amount (parts by mass) shown in Table 1 to 100 parts by mass of water, the mixture was held at 95 ° C. for 2 hours for dissolution. Thereafter, calcium carbonate and starch in the amounts (parts by mass) shown in Table 1 were added to the liquid maintained at 95 ° C., and further maintained at 95 ° C. for 1 hour, followed by cooling to obtain a granulated aqueous solution. .

(Stirring / heating process)
To 100 parts by mass of the granulated aqueous solution maintained at 50 ° C. while stirring, 0.06 parts by mass of ethyl acetate was added as a granulation aid, and further stirred at the same temperature. Next, the lacquer is gradually added to the granulated aqueous solution, and while stirring and dispersing, the granulated aqueous solution is heated according to the heating pattern shown in Table 1 (FIGS. 1 to 3), and finally, 5 hours. Over 95 ° C. Thereafter, the heating was stopped and the mixture was naturally cooled to 50 ° C. to produce a granular porous explosive.

  Next, a granular porous explosive was taken out from the granulated aqueous solution, blown with hot air of 50 ° C. and dried to obtain a granular explosive (granulated product or propellant particles). The obtained granular explosive was subjected to antistatic treatment (fluidity improving treatment) by adding 0.2 part by weight of graphite to 100 parts by weight of the explosive and attaching the graphite to the surface of the explosive by a mixing machine. . In the following examples, the antistatic treatment was similarly performed.

  Each evaluation shown in Table 1 was performed for the granular explosives (granulated products or propellant particles) obtained in Examples 1 to 8 and Comparative Example 1. An SEM photograph (appearance photograph and sectional photograph) of the granular explosive obtained in Example 1 is shown in FIG. 4, and an SEM photograph (appearance photograph and sectional photograph) of the granular explosive obtained in Comparative Example 1 is shown in FIG.

  As apparent from FIGS. 4 and 5, the granular explosive of Example 1 was porous, but the granular explosive of Comparative Example 1 did not have pores. The gas generation rate of the granular explosive of Example 1 is 202 bar / msec, the gas generation rate of the granular explosive of Comparative Example 1 is 71 bar / msec, and the granular explosive of Example 1 is compared with the granular explosive of Comparative Example 1. The gas generation rate is greatly improved.

  When the cross-section was observed, the granular explosives obtained in Examples 2 to 8 were all circular or elliptical and shapes similar thereto, and were porous with vacancies inside.

Examples 9 to 16, Comparative Example 2
Each granular explosive (propellant particle) obtained in Examples 1 to 8 and Comparative Example 1 was subjected to Examples 9 to 16 and Comparative Example 2, respectively, and pressed to obtain a pressed product under the conditions shown in Table 2. It was. Each measurement shown in Table 2 was performed on the obtained pressed product. Each SEM photograph (appearance of each pressed flat product and enlarged photograph of the cross section) is shown in FIGS.

  When comparing the granular explosives of Example 9 and Example 1 of Table 1, the provisional specific gravity is slightly reduced and the gas generation rate is increased by the compression.

Examples 17-19
In the surface glue liquid shown in Table 3, the pressed product of Example 10 was immersed under the conditions shown in Table 3 to obtain a surface glue treated product. Each measurement shown in Table 3 was performed on the obtained surface treated product.

  When comparing the granular explosives of Examples 17 to 19 and Example 10 of Table 2, the gas generation rate is decreased and adjusted by the surface treatment.

The figure which shows the temperature rising pattern in a temperature rising process. The figure which shows another temperature rising pattern in a temperature rising process. The figure which shows another temperature rising pattern in a temperature rising process. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Example 1. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Comparative Example 1. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Example 9. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Example 10. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Example 11. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Example 12. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Example 13. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Example 14. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Example 15. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Example 16. The SEM photograph of the external appearance and cross section of the granular explosive obtained in Comparative Example 2.

Claims (9)

Preparing a lacquer containing an explosive component, an organic solvent, nitrate and / or sulfate;
A step of preparing a granulated aqueous solution having a specific gravity (20 ° C.) of 1.0 to 1.1,
After adding the lacquer to the granulated aqueous solution, the temperature-raising step of raising the temperature of the granulated aqueous solution to a temperature exceeding the boiling point of the organic solvent while stirring.
A method for producing a granular porous explosive.   Furthermore, the manufacturing method of the porous explosive of Claim 1 which has a pressing process which makes a porous explosive flat by a rolling means.   Furthermore, the manufacturing method of the porous explosive of Claim 1 which has the surface process which coat | covers the surface of a porous explosive with a coating agent.   The method for producing a porous explosive according to any one of claims 1 to 3, wherein the organic solvent is a combination of a good solvent and a poor solvent for the explosive component.   The manufacturing method of the porous explosive of any one of Claims 1-4 whose content of the nitrate contained in the said lacquer and / or sulfate is 1-70 mass parts with respect to 100 mass parts of explosive components.   The manufacturing method of the porous explosive of any one of Claims 1-5 whose specific gravity (20 degreeC) of the said granulated aqueous solution is 1.005 to 1.05. It is a granular porous explosive whose temporary specific gravity calculated | required by the following measuring method is 0.5-0.9 g / cm < ³ >, Comprising: The porous explosive obtained by the manufacturing method of Claim 1.
(Measurement method of provisional specific gravity)
When a cylindrical porous explosive in an amount that fills the cylindrical container is poured into a glass cylindrical container (inner diameter 65.8 mm, height 155.9 mm, volume 530 cm ³ ) with one end closed and the other end opened. The explosive amount (g) is measured, and the ratio of the explosive amount (g) to the volume (cm ³ ) of the cylindrical container is determined as a provisional specific gravity (g / cm ³ ).   The porous explosive according to claim 7, wherein a gas generation rate (DP / DT) of the porous explosive is 150 to 500 bar / msec.   The porous explosive according to claim 7 or 8, wherein the porous explosive is a rifle propellant.