JPS5930791A - Aqueous explosive composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydrous explosive composition containing inorganic nitrates as a main component. The present invention relates to a water-containing explosive composition which has improved explosive properties by significantly improving the bubble stability and significantly lowering the crystallization temperature of inorganic nitrates.

Conventionally, air bubbles have been introduced into hydrous explosives mainly composed of inorganic nitrates, and it is known that these air bubbles, together with sensitizers such as metal aluminum powder, play an important role in improving the detonation sensitivity of hydrous explosives. ing. There are several methods for introducing air bubbles, such as introducing air bubbles using a mechanical device, introducing air bubbles by adding a porous or hollow substance, and introducing air bubbles using a blowing agent. It cannot be said that it is stable, and the bubbles gradually decrease or become localized, causing a decrease in complete explosiveness. In addition, since the water content of hydrous explosives is as low as 10 to 80%, the inorganic acid rings such as ammonium nitrate are in a supersaturated state at room temperature, resulting in huge crystallization and becoming heterogeneous, resulting in a significant drop in explosive properties. It is the cause. Calcium nitrate, sodium nitrate, etc. are usually added to improve this problem, but these have the disadvantage that the calcium and sodium components do not contribute to gasification in the event of an explosion.

In order to solve such problems, this invention was made, and contains inorganic nitrates as the main component, water, combustible material, binder component, optionally a sensitizer, and a gelling agent. The present invention provides a hydrous explosive composition characterized in that it contains microfibrillated cellulose.

The MFO used in this invention has a valve manufactured by Japanese Patent Application Laid-Open No. 56-1
It is obtained by beating according to the method shown in the specification of No. 00801, and is defined in the same specification as "microfibrous cellulose", and is a cellulose in which the bulbs are uniformly dispersed in water. means. In other words, when the bulb is suspended in water and passed through a special homogenizer several times, a shearing force is applied under high pressure and the bulb fibers are beaten and become microfibrillated (the original fiber structure is lost, forming lamellae). composed of sheets or microfibrils) to increase surface area. This increase in surface area depends on the number of passes through the homogenizer, ranging from the initial specific surface area of 1-2°/2 of the raw material valve to more than 2°/1. Due to the increase in surface area, Q, MFC does not easily retain water or organic solvent, and the suspension stability is dramatically improved, and the cellulose concentration is 0.
．． A 5% aqueous dispersion leads to a situation where cellulose does not settle and separate even if left for 24 hours.

The hydrous explosive composition of the present invention is characterized in that it contains the above-mentioned more Mya, and the bubbles introduced into the composition by the above-mentioned methods are significantly stabilized. It has the excellent property of significantly lowering the crystallization temperature.

The NFC used in the compositions of this invention may contain up to about 6% by weight of cellulose. Therefore, the cellulose content in the MFC can be up to about 6% by weight based on the total water content of the composition of the invention, in which case no additional water is needed. Since MFC has the effect of stabilizing bubbles even when added in small amounts, it is appropriate to add 0.05% by weight or more based on dry cellulose based on the water in the composition, especially 0.4% by weight or more. Containing it has a great stabilizing effect. -1 fcMFo as an additive lowers the crystallization temperature when ammonium nitrate is used instead of nitrate, but 0.0
The effect tends to be large in the range of 5 to 2.0% by weight.
The amount of M1+'C added is appropriately selected in consideration of other components.

The reason why M1+'O used in this invention significantly stabilizes the bubbles in the hydrous explosive and greatly suppresses the crystallization of ammonium nitrate is considered as follows.

In other words, MFC consists of cell openings and microfibrils that are extremely uniformly dispersed in water (1).As mentioned above, it has a fine fibrillar structure, a large surface area, and shape retention, so it can evenly disperse air bubbles and ammonium nitrate in the system. It is thought that it can be dispersed and maintained and stabilized in a three-dimensional structure.

When adding MFO to a hydrous explosive, MFOOI (I) is neutral, so it does not affect the pH of the system, does not inhibit the stability of metal aluminum powder, etc., and is also effective against gelation of guar gum. It has no adverse effects and can be easily gelled with chromium-based or antimony-based gelling agents.Furthermore, in terms of chemical composition, it is almost pure cellulose, so in the event of an explosion, the entire weight of MPO is completely converted into gas. It also has the advantage of contributing to an increase in explosive force.

The inorganic nitrates contained in the composition of this invention include:
Examples include ammonium nitrate, calcium nitrate, and sodium nitrate. These act as oxidizing agents, and ammonium nitrate is preferred, but calcium nitrate and/or sodium nitrate may also be used in combination. The appropriate content of inorganic nitrate is 65 to 75% by weight. Further, the total water content is suitably 5 to 20% by weight. Examples of combustible materials include starch, wood flour, oil, etc., and 5 to 8% by weight is suitable. In addition, guar gum, carboxymethyl cellulose,
Examples include hydroxyethyl cellulose, and 0.5 to
Contains 1% by weight.

As the sensitizing agent that may be added as desired, high explosives such as trinitrotoluene and trimethylenetrinitramine can be used.
Examples of + include metal powders such as aluminum, -magnesium-aluminum alloy, and silicon iron. Further, in order to prepare a slurry-like hydrous explosive, examples of the gelling agent of the above-mentioned binder, which is optionally added, include sodium dichromate, sodium pyroantimonate, and the like.

The composition of the present invention can be produced by mixing all the components at once and stirring the mixture using a conventional stirrer, for example, a stirrer with propeller-shaped or paddle-shaped blades. Alternatively, a predetermined amount of solid composition is mixed in advance, and M
It can also be produced by adding water to the FO and stirring to homogenize it, or adding it without adding water little by little into the mixture of the solid components while stirring. Alternatively, after mixing MFO into the solid component mixture with stirring, the required amount of water may be added, or water may be added to the solid component mixture first and MFC may be mixed after fc separation. .

Next, this invention will be explained with examples.

Examples 1-4. Comparative Example 1 Water 2 (1', ammonium nitrate 801°, calcium nitrate 10°, sodium nitrate 61°) and guar gum (globylene oxide added, low viscosity product) 0.5F were placed in a beaker and stirred with a magnetic stirrer. In Example 1, MFO (water 97.6% by weight, cellulose content 2.4%) 1y and water 92 were added to the liquid, in Example 2 the above MFC22 and water 82, and in Example 8 the above MFC !5P and water 5?, MF f:!1 in Example 4
In Comparative Example 1, 10 liters of water was added and stirred.

Then each was placed in a lab mixer (approximately 7000 rpm).
After stirring for 10 minutes and mechanically generating air bubbles,
The mixture was transferred to a measuring cylinder of xoog7 and allowed to stand, and the state of bubbles was comparatively observed.'fc (fc without adding gelling agent to evaluate the stability of bubbles in a short period of time).

The results are shown in Table 1, and the system containing no MFO (Comparative Example 1)
), most of the bubbles floated and separated just one hour after the stirring was stopped, whereas in the systems in which MFC was added (Examples 1 to 4), the bubbles were significantly stabilized as the amount of MFO added increased. In particular, when the cellulose/total water content (wt%) in the MFC was 0.4% or more, the bubbles remained well dispersed for more than two weeks.

(Below margin continues on next page) Examples 5 to 8. Comparative Example 2 After preparing each sample under the same conditions as Examples 1 to 4 and Comparative Example 1, micro hollow glass spheres ("Glass Bubbles B15 type" manufactured by Sumitomo 3M, particle size of about 80 μm, Add 0.225' of bulk specific gravity 0.1W/Q:) to each sample as a substitute for air bubbles, stir with a magnetic stirrer, then transfer to a 100i measuring cylinder and compare the flotation and separation status of glass spheres. Observed.

The results are shown in Table 2, which shows the same tendency as Table 1, and M
The addition of FC showed a significant stabilizing effect.

Examples 9-17. Comparative example 8~? The following experiment was conducted to compare the effect of ammonium nitrate on crystallization retardation. The components of each composition in Table 8 were mixed in a beaker and heated to 60° C. in a hot water bath without stirring to completely dissolve fc (MFO is insoluble). The obtained liquid was kept at room temperature (
The crystallization temperature was measured while cooling naturally at 20°C (20°C).
The 7'CMFC used was 2.4% by weight of cellulose and 97% by weight of water.
．． 6% by weight). In both cases, needle-like crystals were observed to grow in a plate-like arrangement over the entire system over a period of several seconds to several tens of seconds. The temperature at the time of crystallization is shown in the lower part of Table 8. As a result, compared to Comparative Example 8 of ammonium nitrate-hydrogen, which crystallized at 88.4°C, when MFC was added as in Examples 9 to 14, the crystallization temperature of ammonium nitrate decreased significantly and reached the maximum temperature. The temperature decreased by 6.6℃. Calcium nitrate, which is commonly used, has a reduction effect of 1 to 5°C as shown in Comparative Examples 4 and 5, but Example 1
From Comparative Example 4 and Comparative Example 4, MFO clearly showed a greater effect with a very small amount. In addition, as in Examples 15 to 17 and Comparative Example 7, the effect of MFO addition was clearly observed even in the presence of calcium nitrate and sodium nitrate, and at most 3
, it was possible to further reduce the temperature by 2°C. In this case as well, the quantitative influence of MFC had the same tendency as in Examples 9-14.

Claims (1)

[Claims] 1. Microfibrillated cellulose is added to a hydrous explosive composition containing inorganic nitrates as a main component, water, combustibles, a binder component, and optionally a sensitizing agent, a gelling agent, etc. A hydrous explosive composition characterized by: