JPS60231484A - Castable explosive composition and manufacture - 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 Field of the Invention The present invention relates to explosive compositions. More particularly, this invention relates to cast explosive compositions having relatively high density, energy and critical diameter. The term "cast" refers to a body that is fluid when compounded at elevated temperatures, but solidifies, or hardens, when cooled to ambient temperature, and is non-flowable or non-extrudable. This is done by "pouring" or casting while pouring into a container of the desired shape in order to solidify the composition into that shape.

Although the compositions of the present invention cure, they also remain ready to be machined into desired shapes.

The compositions of the present invention are prepared by raising the temperature to form a water-in-oil emulsion, which upon cooling forms a casting composition. The composition comprises an inorganic oxidizing agent salt,
An organic liquid fuel that is immiscible with water, water with a volume of less than about 5, any fuel or sensitizer, and an elevated compounding temperature to form a water-in-oil emulsion, but at lower or ambient temperatures. By weakening the emulsification and crystallizing the inorganic oxidizing salt, casting
It contains a special type of emulsifier that allows the product to form.

Water-in-oil emulsified explosives are well known in the art, e.g., U.S. Pat.
22.258 and 4,141,767. Such explosive compositions contain a continuous phase of an organic liquid fuel immiscible with water and a discontinuous phase of an emulsified aqueous inorganic oxidant salt solution. These explosive compositions usually contain density-lowering agents for sharpening purposes.

These compositions have a greasy consistency that makes them water resistant and generally extrudable.

Past efforts have focused on preparing stable emulsion explosive compositions and thus preventing or minimizing the disruption or weakening of the emulsion and the formation of crystallization of inorganic oxidant salts that are initially dispersed through the continuous fuel phase. I came for it. This has been accomplished by generally using about 8 or more cycles of water to lower the crystallization temperature of the oxidizer salt solution and especially the emulsion which is stable to emulsion breakdown. In contrast, the present invention uses water below about 5% and a type of emulsifier that does not form a particularly stable emulsion, weakening the emulsion and producing crystallization of the oxidant salt. The composition is made into a shaped cast product.

Low moisture emulsions are evident from U.S. Pat. No. 4,248,644, which discloses that the melt contains ammonium nitrate as a discontinuous phase and that the composition contains substantially no water in the fuel. discloses emulsifying explosive compositions in the form of "bath melts". L
However, this composition remains stable even after cooling to ambient temperature.
“Greaky consistency.”

Contains an emulsifier of the type that imparts. Thus, low water per se does not guarantee the formation of a casting composition. The casting compositions of the present invention require the combination of low levels of water and the special emulsifiers described herein.

The compositions of the invention have advantageous properties. There has been a widespread need for explosive compositions that can be poured while hot into containers of various shapes, but which can be cast without having to be cooled, cast, or hardened into the shape of a container. In the past, these types of explosives were cast from self-molded explosives such as TNT, Composition B, and Pentlite. However, stiff compositions are relatively expensive.

The casting compositions of the present invention have physical properties similar to cast autoexplosives due to their high density energy content, but the cost of the ingredients is much lower. Thus, a major benefit of the present invention is to provide an easy-to-cast explosive composition containing relatively inexpensive ingredients. In addition to stiffness, the composition loses its greasy consistency upon cooling and precipitation of oxidant salts, although it retains adequate water resistance due to the hardened nature of its surface. Due to its ease of handling, the composition remains fluid for some time even after cooling Lu to lower the crystallization temperature of the salt.

When initially formulated at elevated temperatures, the compositions of the present invention have a greasy consistency and are in the form of a water-in-oil emulsion. Kneading is advantageous for many reasons. The emulsion form is finely and evenly dispersed throughout the continuous fuel phase, increasing the ease with which the oxidizer and fuel warp. The oxidizer salts initially disperse through the fuel phase as droplets in solution at elevated temperatures, and as the composition cools, precipitation of the salts within the droplets physically inhibits the formation of fine salt crystals. The resulting stiffness enhances the homogeneity between the oxidizer and the fuel. Another benefit is that the goose emulsion is liquid and can be bong transported or extruded as desired. As the emulsion cools, the greasy nature is immediately lost due to gradual crystallization of the salts, and if t<, the composition remains stable even after cooling below the crystallization temperature of the salts. It retains its emulsified liquid texture during manufacturing. This makes the composition similar to its initial texture as an emulsion even at lower temperatures. In this way, the addition of other ingredients such as solid sensitizers or density reducers can be carried out at lower temperatures. Shrinkage and/or voids can be minimized after addition to the container.

And the danger to people of high temperature material processing can be reduced. Non-emulsifying compositions will harden rapidly after cooling below the crystallization melt temperature of the ingredients.

The inorganic oxidizing agent salt is used in amounts ranging from about 45% to about 92% of the total composition.2 The oxidizing agent salt is preferably an ammonium nitrate salt, but other salts may also be used. Other oxidant salts are selected from the group consisting of ammonium, alkali and alkaline earth metal nitrates, chlorates and perchlorine. Preferably, about 10% to about 65% of the total oxidant salt is added in particulate or sized form.

The water-immiscible organic liquid fuel that forms the continuous phase of the composition when blended at elevated temperatures is generally present in the order of about 2% to about 15% by weight of the total composition. The actual I used may vary depending on the particular immiscible fuel(s) and, if any, other fuels used. The immiscible organic liquid fuel may be aliphatic, cycloaliphatic and/or aromatic, and may be saturated or unsaturated as long as the straw remains liquid at the compounding temperature. Preferred fuels include mineral oils, waxes, paraffin oils, benzene, toluene, quinoa and mixtures of liquid hydrocarbons commonly referred to as petroleum distillates such as ganolin, kerosene and diesel fuel. Particularly preferred liquid fuels are mixtures of mineral oil, JI62 fuel oil, paraffin wax, microcrystalline wax and straw.

Aliphatic and aromatic nitro compounds can also be used. Halogenated organic fuels can also be used in up to about 25% of the fuel. Mixtures of the above may also be used.

Water can be used at about 5% or less of the total composition. Organic liquids that are miscible with water can partially replace water as solvents for the salts, and such liquids act as fuels for the compositions. Miscible liquid fuels may include alcohols such as methyl alcohol, glycols such as ethylene glycol, amides such as formamide, and similar nitrogen-containing liquids. The use of less water is an important direction of the present invention.

Optionally, solid or other liquid fuels or both can be used in addition to immiscible organic fuels.

Examples of solid fuels that can be used are pulverized aluminum particles; pulverized carbonaceous materials such as giltstone or coal; pulverized vegetable granules such as flour; and sulfur.

Liquid fuels include the water-miscible fuels mentioned above.

Particularly selected solid fuels can be used in amounts up to about 5% by weight to increase the density and energy of the composition. Granular, finely divided, or perforated grade aluminum can also be used, with finely divided being preferred.

In some cases, a sensitizing agent can also be used, and at a temperature of 5'C approximately 15
Give a critical diameter not larger than 0u. The critical diameter is the smallest diameter at a given temperature that will reliably detonate an explosive at a given temperature. ], 5°/cc. At relatively high densities above 5°/cc, sensitizers are generally used to provide moderate sensitivity.

The sensitizing agent may be selected from the group consisting of particulate metals, molecular explosives and mixtures of dough ingredients. Granular aluminum shavings or other metal particles can be used in a range of up to about 50 particles. Aluminum particles are paint grade,
It may be finely ground or granular. An example of a particulate molecular explosive is pentaerythritol tetranitrate (PE
TN), cyclotrimethylenetrinitramine (RDX)
, trinitrotorny/(TNT), cyclotetramethylenetetranitramine (HMX) and nitrocellulose.

Other types of molecular explosives are water-soluble salts such as amine nitrates or perchlorates, including monomethylamine or ethylenenoamine nitrates, and alkanolamine salts such as ethanolamine nitrate or chloride.

Molecular explosives can be used in a range of about 10 to about 70 weight percent, preferably about 45 weight percent. A preferred sensitizer is RDX, alone or in combination with finely ground aluminum.

Emulsifiers are key ingredients in the compositions of the present invention. The emulsifier must be capable of forming a water-in-oil emulsion at elevated compounding temperatures.

In addition to stiffness, the emulsifier must be capable of weakening the emulsification upon cooling so that the inorganic oxidant salt in the solution precipitates out at a temperature below the crystallization temperature of the solution.

Thus, the emulsion should be such that it is inherently unstable in the composition and will readily precipitate as the composition is cast. Emulsifiers that have been found to yield compositions with straw-like properties include aliphatic amines having the formula: :RNI-32゜Here, R is carbon atom 4
It has a chain length in the range of ~22. Acidic salts of fatty amines such as sulfosuccinic acid disodium ethynelated nonylphenol half ester; complex iphosphate ester (SYnFac9214); and sucrose stearate and straw examples are anions; Represents the grade of cationic and nonionic milking agents.

Emulsifiers cause water-in-oil emulsions to form at elevated compounding temperatures, but also weaken the emulsification at ambient temperatures and precipitate inorganic acid arsenic salts to produce casting compositions. Emulsifiers are used in amounts of about 0.2 to about 5 parts. It is desirable for the emulsifier to contain saturated carbon and arsenic chains as its lipophilic portion, although unsaturated forms can also be used. Although unsaturated forms may not form castings as easily or quickly as saturated forms, saturated forms also tend to form more stable emulsions. Aliphatic amine or its emulsifier salt is 14 to 1
Preferably, the aliphatic amine has a chain length of 8 carbon atoms, and more preferably the aliphatic amine is an alkylammonium salt composed of saturated molecules having a chain length of 14 to 8 carbon atoms.

The aliphatic amine emulsifiers of this invention can also act as crystallinity modifiers in that they control crystal growth of oxidant salts and prevent the formation of larger desensitizing crystals.

Although it is desirable for the compositions of the present invention to have high densities, the compositions can be reduced from their natural densities by the addition of density-lowering agents such as small hollow particles such as plastic or glass materials and perlite. be able to.

In addition to kneading, air bubbles may be mixed into the composition during formation, or a dash of a chemical gas releasing agent such as sodium nitrite may be introduced. The dough chemically decomposes in the composition creating air bubbles. The use of density reducing agents to increase sensitivity is well known in the art.

The compositions of the present invention are formulated by initially forming a solution of the oxidant salt(s) in the melt or, if water is present, by raising the temperature above the crystallization or solidification temperature of the salt. This melt or solution is then added to a solution of milk shavings and an immiscible organic liquid fuel, and if treated sufficiently vigorously, especially at ambient or elevated temperatures, the oxidizer salt forms a continuous organic liquid fuel phase. This produces an emulsion of the bath melt or solution.

Normal stiffness can be substantially achieved by constant rapid stirring. Stirring should be continued until the formulation is homogeneous. Any solid, particulate fuel and/or oxidizer salts and other ingredients, if any, are then added and stirred through the formulation by conventional equipment. The compounding process can also be accomplished in a continuous manner as known in the art. Any solid particulate fuel, such as any particulate oxidizer salt or aluminum particles, is preferably added at ambient temperature and the entire composition is cooled to a temperature below the freezing or crystallization temperature of the oxidizer salt. Then it occurs. As previously mentioned, the crystallization ratio of oxidizer salts is limited even at temperatures below the crystallization temperature, over a certain amount of time, and due to ease of handling even when containing 60% solids. The rate of hardening depends on the degree of purification of the original emulsion and on the shear strength and intensity of the shear that the composition undergoes during processing while it is below the crystallization temperature. It is something. The emulsifier and type of liquid fuel also affect cure speed.

It is advantageous to pre-dissolve the emulsifier in the organic liquid fuel before adding it to the oxidizer salt melt or liquid. This method allows emulsions to form quickly and with minimal agitation. The emulsifier can be added separately and just before emulsification, if desired or if, for example, the emulsifier degrades at the high temperature of the fuel.

The following table further illustrates the invention.

In Table 1, Examples A and B were prepared by the method described above and are representative compositions of the invention. Example A contains multiple dry AN (ammonium nitrate) sized particles (50%) and no aluminum. In contrast to stiffness, Example B is less than stiffness I.
The finely pulverized aluminum contains 39 cycles, which gives Example B a much stronger density and considerably more energy. The residual example shows a deformation on the components. Examples GL and O incorporate glass microballoons and thus have relatively low density but high sensitivity. The example is 40%
Contains dry potassium perchlorate. Examples of other emulsifiers that have been found to be suitable for producing casting compositions according to the present invention are disodium ethoxylated nonylphenol half ester of sulfosuccinic acid (Syn Fac 92]4) and sucrose stearate.

Table 1 illustrates sensitized compositions having critical diameters not greater than about 50 mm at a temperature of 5'C. Example A contains RDX as the single sensitizer and has a density of 1.
65 ri/cc, but still superior in sensitivity than a 1-diameter carved 12 detonator, which is about 25 orders of magnitude smaller. 1TIFCO Example B contains RDX and 30% finely ground aluminum as a composite sensitizer, and has a density of At 1.81.9/cc, it was possible to make a candlestick with a diameter of a small diameter. Example B had an extremely high engineering energy (22]]Cal/y-) due to the presence of aluminum. When formulating Example B, form the emulsion at 130°C i
The combination of AN (ammonium nitrate) and SN (sodium nitrate) salts had a crystallization temperature of 120 °C) and was cooled to 80 °C by adding aluminum and RDX at ambient temperature. Ta. The resulting composition still had a greasy feel after being mixed in solids for more than an hour. Examples C-E show variations in ingredients. Examples F and G contain potassium nitrate as the additional oxidizer salt, and Example G contains a multineedle sensitizer (70% RDX). Other examples of emulsifiers found to produce casting compositions in accordance with the present invention include half ester of disodium ethoxylated nonylphenol of sulfosuccinic acid: morganophosphate ester (Syn Fac9214).

The compositions of the present invention are also EJ capable for most common explosive applications. When initially formulated, the composition is extrudable and transportable, allowing it to be filled into a variety of container configurations for a variety of uses. The sensitized particles have physical and chemical properties similar to those of casting self-explosives, and thus can be used in boosters, munitions loading, artillery shells, etc.

Although the invention has been described with reference to certain illustrative and preferred embodiments, it will be obvious to those skilled in the art that various modifications may be made. Such variations are also considered to be within the scope of the invention as set forth in the appended claims.

Claims (1)

[Claims] ■) An explosive composition consisting of an inorganic oxidizing agent, a salt; an organic liquid fuel that is immiscible with water; characterized by containing an emulsifier that causes the water-in-oil emulsion to form a form 1 attack at elevated compounding temperatures, weakens the emulsification of the emulsion, and causes the inorganic oxidizer salt to crystallize at ambient temperature to form a casting composition. Casting explosive composition. 2) The emulsifier has the following formula: RNH2 (where R is 14 carbon atoms)
acid salts of such aliphatic amines; disodium ethoxylated nonylphenol hemi-nysteltate of sulfosuccinic acid; complex organophosphate nystelt; and hisanoclose. The composition according to claim 1), which is selected from the group consisting of Stearare-1. 3) The composition according to claim 2), wherein the emulsifier is saturated. 4) A composition according to claim 2) in which the emulsifier has a chain length lying in the range from 14 to 18 carbon atoms. 5] The composition according to claim 3), wherein the emulsifier is alkylammonium acetate. 6) The composition of claim 1), wherein the composition includes a sensitizing agent to provide a non-canine critical diameter of about 150 mm at a temperature of about 5°C. 7) A composition according to claim 6), wherein the sensitizing agent is selected from TNT, RDX, PETN, HMX-, granular aluminum, nitrocellulose, and mixtures thereof. 8) The composition of claim 7), wherein the sensitizing agent is RDX, making up at least about 10 parts of the total composition. 9) Composition 1.10)R according to claim 7), wherein the sensitizer comprises a mixture of RDX and granular anosiminium
, DX are present in a part I of at least about 10, and the aluminum is present in a part I of at least about 20. 11) Up to 20% of additional inorganic oxidizer salts selected from the group consisting of ammonium, alkali and alkaline earth metal salts of nitric acid, chloric acid and perchloric acid. Composition of. 12) about 4 additional oxidizer salts selected from the group consisting of ammonium, alkali and alkaline earth metal salts of perchloric acid;
The composition according to claim 1), which contains up to 0 parts. 13) The composition according to claim 1, which contains a density-lowering agent for lowering the density of the composition. 14) (a) A water-in-oil emulsion containing an inorganic oxidizing agent salt, about 5% or less water, a water-immiscible organic liquid fuel, and an emulsifier, the emulsion being emulsified. (b) cooling the emulsion to an environmental temperature below the crystallization temperature; (c) By adding an emulsifier, a water-in-oil emulsion is formed at an elevated blending temperature, but the emulsion weakens the emulsion and precipitates inorganic oxidant salts at ambient temperature, resulting in a casting composition. 1. A method for producing a cast explosive composition, characterized in that it produces a product.