JP5987446B2 - Triple base propellant composition - Google Patents

Description

  The present invention relates to a triple-based propellant composition used, for example, in gun ammunition. More specifically, the present invention relates to a propellant composition considering safety during handling and storage.

  Conventionally, triple-base projectiles have been used for ammunition for artillery such as a howitzers. This triple-base propellant was developed for the purpose of increasing combustion power, reducing gun erosion (burning), reducing muzzle flame, etc. without increasing the combustion temperature. The composition of the triple base propellant uses nitrocellulose, nitro plasticizer, nitroguanidine as a base, and additionally contains additives such as stabilizers, flame retardants, and brighteners (for example, Non-Patent Document 1). reference). Nitroglycerin is generally used as the nitro plasticizer, but Non-Patent Document 1 also proposes the use of diethylene glycol dinitrate.

Such triple base propellants are generally produced using a known solvent companding method. The main steps of the solvent drawing method will be described below.
[Kneading step] The raw material of the triple base propellant is put into a kneading machine and stirred to obtain a kneading agent having a desired viscosity.
[Drawing step] After the kneading agent is put into the drawing machine, pressure is applied to the kneading agent to obtain a string-like extruding agent formed into a desired shape with a die and a pin.
[Cutting step] The extruding drug is passed through a rotary cutting machine or a guillotine cutting machine to obtain a cutting drug cut into a desired drug length.
[Drying step] The cutting agent is dried with warm air until the desired moisture value and residual solvent value are obtained to obtain a propellant.

"Firearms Ammunition Technology Handbook" Japan Defense Technology Association, February 2, 2005, p.351-352

  Although the triple base propellant composition using nitroglycerin as a nitro plasticizer described in Non-Patent Document 1 has no problem with combustion temperature and manufacturability, it contains a highly sensitive nitroglycerin, There was a problem with safety during handling and storage.

  In contrast, since diethylene glycol dinitrate is less sensitive than nitroglycerin, the use of diethylene glycol dinitrate as a nitro plasticizer is expected to improve safety during handling and storage. However, when the blending amount of diethylene glycol dinitrate is too large, the handleability decreases due to the increased elasticity of the extruding agent, and the variation in shrinkage rate of the cutting agent in the drying process occurs, leading to a decrease in manufacturability. Moreover, since the compounding quantity of the nitroguanidine which has the effect of lowering | hanging a combustion temperature falls relatively, it becomes easy to burn a gun barrel. On the other hand, if the amount is too small, the shortage of the plasticizer component leads to a decrease in ductility and an increase in brittleness, resulting in a decrease in mechanical properties. That is, when a large impact at the time of shooting is given to a propellant having low ductility or high brittleness, the propellant is easily crushed. Thereby, it becomes difficult to obtain stable combustion of the propellant, and it becomes difficult to stabilize the velocity of the bullet for each shot. That is, depending on the blending amount, the required manufacturability, mechanical properties and erosion properties cannot be satisfied. However, in the said nonpatent literature 1, there is no detailed description regarding the compounding quantity etc. in the case of using diethylene glycol dinitrate as a nitro plasticizer.

  Accordingly, an object of the present invention is to provide a triple base propellant composition that is excellent in manufacturability, mechanical properties, and erodibility, and has high safety during handling and storage.

  That is, the triple base propellant composition of the present invention contains component (a) diethylene glycol dinitrate, component (b) nitrocellulose, component (c) nitroguanidine, component (a) diethylene glycol dinitrate, component (b ) The content of component (a) diethylene glycol dinitrate is 15 to 46% by weight with respect to 100% by weight of the total weight of nitrocellulose and component (c) nitroguanidine, and the content of component (b) nitrocellulose is 20 to 50% by weight, and the content of component (c) nitroguanidine is 28 to 55% by weight.

  According to the triple base propellant composition of the present invention, the following effects can be exhibited. First, by using a component (a) diethylene glycol dinitrate having low sensitivity as a nitro plasticizer, safety during handling and storage can be ensured. In addition, component (a) diethylene glycol dinitrate, component (b) nitrocellulose, component (c) nitroguanidine, and component (a) diethylene glycol dinitrate, component (b) nitrocellulose, component (c) nitro By setting the content of guanidine within a specific range, excellent manufacturability, mechanical properties, and erodibility can be ensured. That is, according to the present invention, it is possible to provide a triple base propellant composition that is excellent in manufacturability, mechanical properties, and erodibility, and has high safety during handling and storage.

Embodiments of the present invention will be specifically described below.
The present invention contains component (a) diethylene glycol dinitrate, component (b) nitrocellulose, and component (c) nitroguanidine in a specific blending ratio. A propellant composition excellent in manufacturability, mechanical properties, and erodibility can be obtained while maintaining safety during handling and storage by using a specific blending ratio.

<Component (a) Diethylene glycol dinitrate>
First, component (a) diethylene glycol dinitrate will be described. Diethylene glycol dinitrate is an energy plasticizer that contains nitrate ester, and is less sensitive to impact than nitroglycerin, which has been used as a nitrate ester energy plasticizer, and is a highly safe substance. is there.

  The content of diethylene glycol dinitrate is 15 to 46% by weight, preferably 25 to 35% by weight, based on 100% by weight of the total weight of diethylene glycol dinitrate, nitrocellulose and nitroguanidine. When the content exceeds 46% by weight, the plasticizer component of the propellant becomes excessive, resulting in a decrease in handling property due to a decrease in the viscosity of the extruding agent and an increase in variation in shrinkage rate of the cutting agent in the drying process. There exists a tendency for the manufacturability of a thing to fall. On the other hand, if the content is less than 15% by weight, the plasticizer component of the propellant composition becomes too small, and the mechanical properties tend to decrease. That is, the shortage of the plasticizer component causes a decrease in ductility and an increase in brittleness, and the propellant is easily destroyed during shooting. As a result, the velocity of the bullets becomes difficult to stabilize after each shot, and further, an explosion occurs due to a detonation reaction in which combustion proceeds at a speed higher than the speed of sound, causing serious damage to surrounding personnel and equipment. There is a case.

<Component (b) Nitrocellulose>
Next, component (b) nitrocellulose will be described. Nitrocellulose (nitrified cotton) is a fuel and a component that functions as a binder (binder) for granulating (graining) the propellant. Nitrocellulose is a nitrate ester obtained by treating cellulose with a mixed acid of nitric acid and sulfuric acid.

  The content of nitrocellulose is 20 to 50% by weight, preferably 27 to 43% by weight, based on 100% by weight of the total weight of diethylene glycol dinitrate, nitrocellulose and nitroguanidine. When the content of nitrocellulose exceeds 50% by weight, it is difficult to reduce the combustion temperature, which is not preferable. This is because the amount of nitroguanidine as an energy base material is relatively reduced. When the content of nitrocellulose is less than 20% by weight, mechanical properties tend to decrease due to a decrease in ductility or an increase in brittleness due to a shortage of binder components. Moreover, manufacturability is impaired due to a decrease in ductility.

<Component (c) Nitroguanidine>
Next, component (c) nitroguanidine will be described. Nitroguanidine is an energy base that is a nitro compound, and is a component having a function of lowering the combustion temperature and improving the explosive power.

  The content of nitroguanidine is 28 to 55% by weight, preferably 34 to 45% by weight, based on 100% by weight of the total weight of diethylene glycol dinitrate, nitrocellulose and nitroguanidine. When the content of nitroguanidine exceeds 55% by weight, the blending amount of nitrocellulose as a binder component and diethylene glycol dinitrate as a plasticizer component is relatively reduced, resulting in a decrease in ductility and an increase in brittleness. The mechanical properties tend to decrease. When the content of nitroguanidine is less than 28% by weight, the blending amount of nitrocellulose increases relatively, so the combustion temperature cannot be reduced, and the erosion of the gun barrel increases and the gun barrel life tends to be shortened. is there.

  The propellant composition of the present invention may contain, in addition to the above-described components, stabilizers, anti-inflammatory agents, brighteners and the like that are used in ordinary propellants as necessary. Examples of the stabilizer include diphenyl urea derivatives such as diphenyl urea, methyl diphenyl urea, ethyl diphenyl urea, diethyl diphenyl urea, dimethyl diphenyl urea, and methyl ethyl diphenyl urea, diphenyl amine derivatives such as diphenyl amine and 2-nitrodiphenyl amine, ethyl phenyl urethane, Examples thereof include phenylurethane derivatives such as methylphenylurethane, diphenylurethane derivatives such as diphenylurethane, and resorcinol. These compounds are used alone or as a mixture of two or more.

  Among these compounds, since the melting point is 120 ° C. or higher, a diphenylurea derivative having a high effect of reliably capturing nitrogen oxides generated from nitrocellulose even at high temperatures, and suppressing the natural decomposition of nitrocellulose, Specifically, methyl diphenyl urea, diphenyl urea or dimethyl diphenyl urea is preferable, and methyl diphenyl urea or dimethyl diphenyl urea is particularly preferable.

  Examples of the flame retardant include potassium sulfate and potassium nitrate, and examples of the brightener include graphite, carbon black, acetylene black and the like, and each ratio is used within a normal range.

Next, a manufacturing method will be described.
A triple base propellant can be produced by extruding the triple base propellant composition of the present invention. First, a predetermined amount of diethylene glycol dinitrate, nitrocellulose, nitroguanidine, and if necessary, a stabilizer, a flame retardant and a brightener are weighed. After weighing, put all the raw materials into the kneader and add an appropriate amount of organic solvent to the kneader and mix uniformly. Next, the mixture is loaded into an extrusion apparatus, a predetermined pressure is applied, and the mixture is extruded through a die to be molded into a predetermined shape and size. Thereafter, the triple base propellant having a predetermined shape and size can be manufactured by cutting and drying.

  In addition, as the organic solvent used in the extrusion molding method, any one that dissolves or swells nitrocellulose as a binder can be used. Examples thereof include organic solvents such as acetone, methyl alcohol, ethyl alcohol, isopropyl alcohol, ethyl acetate, butyl acetate, diethyl ether, toluene, and methyl ethyl ketone. These mixed solutions can also be used. In particular, acetone, ethyl alcohol, and diethyl ether are preferable in terms of excellent compatibility with nitrocellulose.

  Next, the propellant which is a molded product will be described. The triple base propellant can be appropriately sized and shaped according to the application. Examples of the shape include a non-porous tube, a single-hole tube, and a porous tube. A single-hole tubular means a cylindrical body or hexagonal cylinder having one through-hole extending in the axial direction, and a multi-hole tubular means a plurality (for example, 7, 19, and 37) through-holes extending in the axial direction. It is a cylindrical body or hexagonal cylinder body having

Hereinafter, specific examples and comparative examples will be given to explain the results of evaluating the manufacturability and properties of the obtained propellant by producing a propellant by extruding a triple base propellant composition. However, the present invention is not limited to the scope of these examples. Abbreviations in Table 1 represent the following meanings. Moreover,% display in Table 1 and the following description is a weight reference | standard.
DEGN: Diethylene glycol dinitrate NC: Nitrocellulose NQ: Nitroguanidine

<Example 1>
A molded product of a triple base propellant composition having the composition shown in Table 1 was produced by the following method.
A mixture of propylene component diethylene glycol dinitrate 33%, binder component nitrocellulose 27% and base component nitroguanidine 40% was mixed with acetone (propellant composition) with acetone. A mixed solution of 55% and ethyl alcohol 45% was added 30% with respect to the weight of the propellant composition, and mixed uniformly with a so-called Werner mixer. The Werner mixer is a device that stirs and mixes with a stirring blade attached to a rotating shaft extending in the lateral direction. This mixture (washer) was then loaded into an extruder. A 12.5 mm die and a 0.5 mm pin are attached in advance to the extrusion apparatus, and the moisturizer is extruded while passing through this die by applying pressure, and is a 19-hole tubular tube having 19 through holes. A cylindrical drug extrudate was molded. The extrudate was cut into a length of 10.0 mm and dried to obtain a granular triple base propellant. The productivity at that time was evaluated by the method described later.
Further, using this triple base propellant, mechanical properties and erodibility were evaluated by the methods described later. The results are shown in Table 1.

<Examples 2 to 6>
Each triple base propellant was manufactured in accordance with Example 1 with the composition shown in Table 1, and the manufacturability, mechanical properties, and erodibility were determined. The results are shown in Table 1.

<Comparative Examples 1-6>
Triple base propellants were produced by the same method as in Example 1 with the compositions shown in Table 1. Each characteristic was evaluated by the same method as in Example 1. The results are shown in Table 1.

Next, a method for evaluating the characteristics of the propellant compositions in Examples and Comparative Examples is shown below.
[Manufacturability]
A method for evaluating manufacturability will be described. The following evaluation criteria evaluated the ease of shaping | molding in the case of extruding the propellant composition of each Example and a comparative example with an extrusion molding apparatus, and the handleability at the time of conveying to a cutting machine.
(Double-circle): The flexibility of the extruding drug was very appropriate, and it was very easy to handle.
○: The extrudate was flexible enough to be handled easily.
(Triangle | delta): Since the flexibility of the extruding medicine was low or too high, it was necessary to handle with care.
X: The flexibility of the extrudate was not appropriate and a problem occurred in handling.
Regarding manufacturability, it is necessary to make ◎ or ○.

[Mechanical properties]
A compression strength test method for evaluating the mechanical properties of the propellant will be described. The compressive strength test was performed using a tensile compression tester (AL-50kNB) manufactured by Minebea Co., Ltd. A sample of a triple base propellant composition as a sample was placed on the center of the sample stage, and then compressed in the length direction at a speed of 30 mm / min for a compression test. Then, the maximum load value and the compressibility were read from the stress strain curve, and the mechanical properties were evaluated. A large impact is given to the triple base propellant when shooting a tank gun, a field gun, etc. Therefore, triple base propellants are required to withstand the impact. In this test, it is necessary that the maximum load value is 23 MPa or more and the compression rate is 8.0% or more.

[Bakeout]
A method for evaluating the erodibility will be described. Here, the combustion temperature, which is an index of erodibility, was calculated. In order to reduce the erosion generated on the inner surface of the gun barrel, it is preferable to lower the combustion temperature as much as possible. The combustion temperature was calculated by a thermal equilibrium calculation known in the art. The combustion temperature calculated by thermal equilibrium calculation should be 2850K or less.

From the test results in Table 1, the following was found.
It became clear that all the triple base propellants shown in Examples 1 to 6 have no problem in manufacturability and erodibility. Furthermore, in the mechanical properties, all have a maximum load value of 25 MPa or more, and all have a compressibility of 8.1% or more, and it was confirmed that there is no problem in the mechanical properties. .

  As shown in Table 1, in Comparative Example 1 in which 13% by weight of diethylene glycol dinitrate is blended, there is no problem with the erosion property, but there are problems with mechanical properties and manufacturability because the plasticizer component is insufficient. all right. On the other hand, in Example 2 in which 15% by weight of diethylene glycol dinitrate was blended, there was no problem in manufacturability, mechanical properties and erodibility, so the blending amount of diethylene glycol dinitrate should be at least 15% by weight or more. It became clear that.

  Further, in Comparative Example 2 in which 48% by weight of diethylene glycol dinitrate was blended, there was no problem with the erosion and mechanical properties, but the plasticizer component was excessive, so the flexibility of the extruding drug became very high, It was found that there was a problem in manufacturability. On the other hand, in Example 3 in which 46% by weight of diethylene glycol dinitrate was blended, there was no problem in manufacturability, mechanical properties, and erodibility, so the blending amount of diethylene glycol dinitrate was at most 46% by weight. It became clear that there was a need to do.

  In Comparative Example 3 in which 18% by weight of nitrocellulose was blended, there was no problem in terms of erosion and mechanical properties, but it was found that there was a problem in manufacturability due to a shortage of binder components. On the other hand, in Example 3 in which 20% by weight of nitrocellulose was blended, there was no problem in manufacturability, mechanical properties, and erodibility, so the blending amount of nitrocellulose should be at least 20% by weight or more. It became clear.

  In Comparative Example 4 in which 52% by weight of nitrocellulose was blended, there was no problem in mechanical properties and manufacturability, but it was found that there was a problem in the erosion property because there was much nitrocellulose having an effect of increasing the combustion temperature. On the other hand, in Example 4 in which 50% by weight of nitrocellulose was blended, there was no problem in manufacturability, mechanical properties and bakeability, so the blending amount of nitrocellulose needs to be 50% by weight or less. It became clear.

  In Comparative Example 5 in which 26% by weight of nitroguanidine was blended, there was no problem in mechanical properties and manufacturability, but it was found that there was a problem in erosion resistance because there was little nitroguanidine having an action of lowering the combustion temperature. On the other hand, in Example 5 in which 28% by weight of nitroguanidine was blended, there was no problem in manufacturability, mechanical properties, and erodibility. Therefore, the blending amount of nitroguanidine needs to be 28% by weight or more. It became clear.

In Comparative Example 6 in which 57% by weight of nitroguanidine was blended, there was no problem with erosion, but the content of nitroguanidine, which is a solid component, increased, and it was found that there were problems with mechanical properties and manufacturability. On the other hand, in Example 6 in which 55% by weight of nitroguanidine was blended, there was no problem in manufacturability, mechanical properties and erodibility, so the blending amount of nitroguanidine was required to be 55% by weight or less. It became clear.

  As described above, the triple base propellant composition of the present invention uses diethylene glycol dinitrate having low sensitivity as a plasticizer component, while ensuring safety during handling and storage, while diethylene glycol dinitrate, nitro By limiting the blending amounts of cellulose and nitroguanidine as described above, it is excellent in manufacturability, mechanical properties, and bakeability.

Claims (1)

In a triple base propellant containing a base consisting of component (a) diethylene glycol dinitrate, component (b) nitrocellulose, and component (c) nitroguanidine,
With respect to 100% by weight of the total weight of component (a) diethylene glycol dinitrate, component (b) nitrocellulose and component (c) nitroguanidine,
The content of component (a) diethylene glycol dinitrate is 15 to 46% by weight,
The content of component (b) nitrocellulose is 20 to 50% by weight,
A triple base propellant composition, wherein the content of component (c) nitroguanidine is 28 to 55% by weight.