JPS6256479A - Production of microcrystal of octogen - Google Patents

Abstract

PURPOSE:To advantageously obtain microcrystals of an isomer actogen of 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane, by adding a solution of a surfactant to a medium in diluting a solution of the 1,3,5,7-tetranitro-1,3,5,7- tetrazacyclooctane dissolved in a solvent with water to deposit the octogen. CONSTITUTION:A solution 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (HMX) dissolved in a solvent, preferably acetone, is diluted with water to deposit octogen (beta-HMX) useful as ammunition. In the process, one or more selected from surfactants, preferably anionic surfactants selected from sulfonates, sulfuric acid ester salts, and phosphoric acid ester salts normally in 0.05-1% concentration are added to the above-mentioned solvent and/or to readily afford only microcrystals of only octogen put to practical use in four isomers of the HMX.

Description

Detailed Description of the Invention (a) Technical Field of the Invention The present invention relates to octogen (hereinafter referred to as β-HMX).
The present invention relates to a method for producing microcrystals of.

(b) Technical background The use of octogen is exclusively for ammunition, and in Japan it is regulated by the Defense Agency standard (NDS K 4305). There are six particle size classes stipulated in this standard, of which class E is classified as "44 μm".
The amount passing through the sieve is 98% or more. The present invention relates to a method for producing octogen defined as class E.

(c) Conventional technology and problems Conventionally, methods for producing microcrystals of β-HMX include:
■By dissolving 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (hereinafter referred to as HMX) in a solvent and cooling this solution, β-H
A method of precipitating MX, ■ A method of dissolving HMX in a solvent and evaporating or distilling this solution to precipitate β-HMX, ■ A method of dissolving HMX in a solvent and converting this solution into a substance that is poorly soluble in HMX. A method of precipitating β-HMX by diluting it with
Additionally, water has generally been used as a substance that is poorly soluble in HMX.

In order to obtain microcrystals of β-HMX, it is necessary to cause a rapid change in concentration, and the means for this are: 1) rapid cooling, 2) rapid dilution, 2) a combination of the above methods 2 and 3. is usually done.

However, it is difficult to obtain microcrystals of β-HMX using such conventional methods. That is, HMX is α-1β-9γ-9
There are four isomers of δ-, and β-HMX is the least sensitive of the four, so only β-HMX is put to practical use. However, in the conventional method described above, α-2γ-9δ- 3 types of H
MX or HMX mixed therein precipitated at the same time, making it impossible to put it to practical use.

Object of the Invention The present invention has been made to solve the problems of the prior art, and its purpose is to facilitate the precipitation of microcrystals of β-HMX, and to provide β-HMX that can be put into practical use. -HMX
It is an object of the present invention to provide a method for producing microcrystals of β-HMX, which allows only β-HMX to be extracted.

(k) Structure of the Invention In order to achieve the above object, the present invention provides a method in which HMX dissolved in a solvent is diluted with water to precipitate β-HMX, in which a surfactant is added to the solvent and/or water. It is composed of

Here, acetone is suitable as the solvent.

Furthermore, surfactants are anionic surfactants, and when classified based on the structure of the hydrophilic group, there are sulfonates, sulfate ester salts, and phosphate ester salts, and at least one selected from these groups. More than one agent is preferred. An example of this is shown in Table 1.

Further, the concentration of the surfactant is preferably 0.05 to 1%. For example, as shown in Examples 1 and 2, the present inventor has found that the desired microcrystals can be reliably produced with 1% at room temperature (20°C) and 0.05% at low temperature (0°C). I confirmed that it can be done. From this, it is understood that the lower the temperature, the better the results even if the concentration of the surfactant is lower. However, it has also been confirmed that if the temperature is too low, it takes time for the precipitation of microcrystals.

From the above, the optimum concentration of the surfactant is determined depending on the temperature used, but 0.05 to 1% is usually sufficient in the range of 0 to 20°C.

If there is equipment to control the temperature, high temperatures (20°C
(above) or low temperature (below 0°C), but the range can be decided based on economic considerations.
It is not particularly limited.

Ku) Examples of the invention Examples will be explained below.

Example 1 15 g of β-HMX was mixed with 600 g of hot acetone (45-5
5°C) and add additional surfactant. Approximately 2 kg of this hot solution of acetone with added surfactant
Pour into water at 0'C with stirring at a speed of 240 rpm. After continuing stirring for about 30 minutes, β-HMX is precipitated, and it is confirmed using a microscope that isomers such as α- and T- are not contained. The crystals are filtered and washed with water at about 20° C. until the surfactant is removed in 1 minute.

The crystals obtained by these operations are sieved through a 44 μm sieve and the passage rate is analyzed. Furthermore, it was confirmed by infrared absorption spectroscopy that this crystal was β-HMX. Experimental results using various surfactants are shown in Table 2.

Example 2 15 g of β-HMX was mixed with 600 g of hot acetone (45-5
5° C.) and further add a surfactant. This hot solution of acetone was added to 1 kg of surfactant at approximately 0°C.
of water with stirring at a speed of 24 Orpm.

Hereinafter, the same operations as in Example 1 are performed. Experimental results using several types of surfactants are shown in Table 3.

From these experimental results, it is clear that when a surfactant is added, microcrystalline β-HMX is formed.

Furthermore, from Tables 2 and 3, it can be seen that thinner crystals can be obtained at lower temperatures. However, this shows that when the temperature is low, even a small amount of surfactant is effective.

Furthermore, the reference example in which no surfactant was added shows that the particle size is coarse.

In addition, in Tables 2 to 6, infrared absorption spectroscopy is performed for β-HM
This is to check whether or not X etc. exists.

If α-HMX, r-HMX, etc. are present in the sample, 14
．． A clear absorption band is observed at wavelengths from 0 to 14.3 μm. On the other hand, β-HMX is 14.0 to 14.3 μm
There is no absorption band at the wavelength of .

The outline of the analysis method is as follows.

Sample 1 is placed in an agate mortar and finely ground (pulverized, then an appropriate amount of a well-dried alkali halide (generally potassium bromide is used) is added, and the mixture is further finely mixed. The sample is pressurized to remove air while forming a transparent tablet with a thickness of 1 to 1 mm.The sample is subjected to an infrared absorption spectrum analyzer, and the relative intensity of transmitted light at each successive wavelength is recorded on a recording paper.

Example 3-1 (Example in which a surfactant is added only to the solvent) 15 g of β-HMX was mixed with 600 g of hot acetone (45-5
5°C) and further add a surfactant. This hot solution of acetone is poured into 1 kg of water at about 0° C. with stirring at a speed of 24 Orpm. Hereinafter, the same operations as in Example 1 are performed. Experimental results using several types of surfactants are shown in Table 5.

Example 3-2 (Example in which surfactant was added only to water) 15 g of β-HMX was mixed with 600 g of hot acetone (45-5
5°C) and heat the acetone to 1 kg of water at approximately 0°C with surfactant at 24Q rpm.
Pour in while stirring at a speed of . Hereinafter, the same operation as on the actual flow side 1 will be performed. Experimental results using several types of surfactants are shown in Table 4.

As is clear from comparing these experimental results with the reference examples in Table 3, surfactants were added to acetone.

When added to water, microcrystalline β-HMX
is obtained.

Example 4 (Example using α-HMX as the starting material) 15 g of α-HMX was mixed with 600 g of hot acetone (45-5
This hot solution of acetone is poured into 1 kg of water at about 0° C. with added surfactant while stirring at a speed of 240 rpm. Hereinafter, the same operations as in Example 1 are performed. Experimental results using several types of surfactants are shown in Table 5.

As the experimental results show, even when the starting material is α-HMX, the isomer obtained by recrystallization is the β type, and the generation of microcrystals is no different from when β-HMX is used as the starting material. No difference is recognized.

Example 5 (Example where multiple types of surfactants are used simultaneously) 15g of HMX was mixed with 600g of hot acetone (45-55℃)
), and the hot acetone solution was added to 1 kg of water at about O'C with two or more surfactants added at 24Orp.
Add the mixture while stirring at a speed of m.

Hereinafter, the same operations as in Example 1 are performed. Experimental results using several types of surfactants are shown in Table 6.

As shown in the experimental results in Table 6, it is clear that the use of two or more types of surfactants does not impede the formation of microcrystals or the β-type.

Effects of the Invention As described above, the present invention provides β by diluting a solution in which HMX is dissolved with water. In the production method for precipitating -HMX, since a surfactant is added to these media, it is possible to easily obtain microcrystals of only β-HMX, which is used for practical use among the four isomers of HMX.

Patent applicant: Nippon Koki Co., Ltd.

Claims (5)

[Claims] (1) In a method in which 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane dissolved in a solvent is diluted with water to precipitate octogen, the interface between the solvent and/or water is A method for producing microcrystals of octogen, which comprises adding an activator. (2) The method for producing microcrystals of octogen according to claim 1, wherein the solvent is acetone. (3) The method for producing microcrystals of octogen according to claim 1, wherein the surfactant is an anionic surfactant. (4) Claim 3, characterized in that the anionic surfactant is at least one agent selected from the group of sulfonates, sulfate ester salts, and phosphate ester salts. A method for producing microcrystals of octogen. (5) The method for producing microcrystals of octogen according to claim 1, wherein the concentration of the surfactant is 0.05 to 1%.