JPS6224399B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a water-in-oil emulsion explosive composition (hereinafter abbreviated as W/O emulsion explosive composition).
The present invention relates to an explosive composition containing a novel emulsifier that forms a W/O emulsion,
By using specific hydrogenated castor oil fatty acid esters and/or polyoxyalkylene hydrogenated castor oil fatty acid esters as emulsifiers,
W/O that has performance superior to conventional known emulsifiers in terms of stability over time of detonation sensitivity (diameter) and detonation sensitivity at low temperatures.
The present invention relates to type emulsion explosive compositions. Regarding the W/O type emulsion explosive composition,
It has been researched for a long time, and the initial ones were because the morphology of the W/O emulsion was unstable (that is, the contact area between the dispersed phase and the continuous phase was relatively small), so explosive sensitizers such as nitroglycerin were used. Or non-explosive sensitizing agents such as monomethylamine nitrate (hereinafter abbreviated as sensitizing substances), or atomic number 13
Compounds of metals other than Groups 1 and 2 of the periodic table, detonation catalytic sensitizers such as water-soluble strontium compounds, or sensitizing oxidants such as ammonium or alkali metal perchlorates, etc. (hereinafter abbreviated as auxiliary sensitive substances) were added to improve the detonation sensitivity at small diameters.
However, W/O type emulsion explosive compositions containing such sensitive substances or auxiliary sensitive substances, etc., may be susceptible to damage if, for example, the above-mentioned sensitive substances separate due to some factor during manufacturing or use. There was a potential danger of becoming extremely sensitive, or of the toxicity of the above-mentioned sensitive substances. In this sense, a W/O emulsion explosive composition has also been disclosed which does not contain any of the above-mentioned sensitive substances or auxiliary sensitive substances and has improved detonation sensitivity in small diameters (enabling detonation with a detonator). For example, according to US Pat. No. 4,110,134, emulsifiers include sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene ether, polyoxyalkylene oleate, polyoxyalkylene laurate, phosphorus Contains acid oleate, substituted oxazoline, and phosphate ester, and contains a glass microballoon as a bubble retaining agent. It has a diameter of about 1.25 inches (31.8 mm) and can be completely detonated with a No. 6 detonator to a tentative specific gravity of up to 1.25. It is written that. According to US Pat. No. 4,149,917, emulsifiers include sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene (4) lauryl ether, polyoxyethylene (2) ether, polyoxyethylene ( 2) By blending stearyl ether, polyoxyalkylene oleate, polyoxyalkylene laurate, phosphoric oleate, substituted oxoline, phosphoric ester, and mixtures thereof, microbubbles are produced without containing a bubble-retaining substance. Adjust the temporary specific gravity to 0.95,
With a diameter of 1.25 inches (31.8 mm), it can be completely detonated with a No. 6 detonator even after two months have passed since manufacture (explosive temperature 21.1℃), and can be completely detonated with a No. 8 detonator even after eight months have passed (explosive temperature 21.1
°C). The number in brackets after oxyalkylene represents the number of moles of oxyalkylene group bonded to one hydroxyl group. It corresponds to the numerical value represented by "m" of the emulsifier defined in the claims. same as below. It is well known that various emulsifiers are used in W/O type emulsion explosive compositions that do not contain the above-mentioned sensitizing substances or auxiliary sensitizing substances. Various emulsifiers that form emulsions are known. However, as can be seen from the fact that W/O type emulsion explosive compositions using emulsifiers other than those described in the above-mentioned US patent specification contain the above-mentioned sensitive substances or auxiliary sensitive substances, etc. That W/
Because the O-type emulsion has poor stability over time, the stability over time of detonation sensitivity at small diameters (25 mm diameter) and low temperatures is extremely poor. Furthermore, even with the W/O type emulsion explosive composition using the emulsifier described in the above-mentioned US patent specification, the stability over time of the detonation sensitivity at low temperatures is sufficiently satisfactory with a smaller diameter (25 mm diameter). It wasn't. The inventors of the present invention have conducted intensive research over a long period of time while taking into account the above-mentioned problems.
A substance that has not been considered as an emulsifier for an O-type emulsion explosive composition is a W/ It has been discovered that it can be formed into an O-type emulsion, and the W/O-type emulsion explosive composition thus obtained has performance superior to conventional known emulsifiers in terms of stability over time of detonation sensitivity at small diameters and low temperatures. The present invention was completed based on the discovery that the invention has the following properties. That is, the W/O emulsion explosive composition of the present invention comprises (a) a dispersed phase of an oxidizing agent aqueous solution consisting of (a) ammonium nitrate or ammonium nitrate and another inorganic oxide salt, and (b) water, (c) fuel oil and/or Containing a continuous phase of combustible material consisting of waxes, (d) an emulsifier consisting of a specific hydrogenated castor oil fatty acid ester and/or polyoxyalkylene hydrogenated castor oil fatty acid ester described below, and (e) microscopic hollow spheres or microbubbles. It is characterized by: The aqueous oxidizing agent solution of the W/O emulsion explosive composition of the present invention contains ammonium nitrate as a main component and contains other inorganic oxidizing acid salts as necessary. Here, the other inorganic oxide salts are, for example, nitrates of alkali metals or alkaline earth metals such as sodium nitrate and calcium nitrate. These inorganic oxidized acid salts may be used alone or as a mixture of two or more. The amount of ammonium nitrate is generally 50% to 94.7% of the total (by weight, the same applies below)
If necessary, other inorganic oxide salts may be contained in an amount of 40% or less of the total inorganic oxide salts containing ammonium nitrate. If the amount of ammonium nitrate is less than the lower limit, the oxygen balance (the relationship between excess and deficiency of oxygen between the oxidizing agent and the combustible agent) will be too poor (oxygen deficiency), resulting in poor explosiveness and aftergassing. If the upper limit is exceeded, the dissolution temperature of ammonium nitrate in water becomes too high, resulting in poor productivity, and the explosive reactivity of ammonium nitrate becomes poor, resulting in poor detonation sensitivity. Regarding the other inorganic oxide salts mentioned above, by adding a small amount, the amount of oxygen supplied can be increased and the dissolution temperature in water can be lowered, improving explosiveness and manufacturability, but if the amount exceeds 40%, Since the amount of solid residue after the explosion increases, the power will be reduced and it will be disadvantageous in terms of economy. Note that the amount of water used in the oxidizing agent aqueous solution is, in principle, 5% to 25%. If it is less than 5%, the melting temperature of ammonium nitrate or ammonium nitrate and other inorganic oxide salts becomes too high, resulting in poor productivity and poor detonation sensitivity due to poor explosive reactivity. If it exceeds 25%, productivity is improved because the melting temperature of ammonium nitrate or ammonium nitrate and other inorganic oxide salts is lowered, but the amount of gas and heat generated after the explosion is reduced, resulting in poor detonation sensitivity and reduced power. low. Fuel oils and/or wax fuel oils include hydrocarbons, such as paraffinic hydrocarbons, olefinic hydrocarbons, naphthenic hydrocarbons, aromatic hydrocarbons, saturated or unsaturated hydrocarbons, petroleum, refined mineral oil,
Lubricants, liquid paraffin, etc. and hydrocarbon derivatives,
For example, nitrohydrocarbons. Waxes include unrefined microcrystalline wax derived from petroleum, refined microcrystalline wax,
These include paraffin wax and the like, mineral waxes such as montan wax and ozokerite, animal waxes such as whale wax, and insect waxes such as beeswax. These fuel oils/waxes may be used alone or as a mixture of two or more. The amount of fuel oil and/or waxes is generally 0.1% to 10%.
%. If the fuel oil and/or wax is less than 0.1%, the stability of the W/O emulsion explosive composition will be poor, and if it exceeds 10%, the oxygen balance will be too poor, resulting in poor explosiveness and aftergassing. The hydrogenated castor oil fatty acid ester and polyoxyalkylene hydrogenated castor oil fatty acid ester which are emulsifiers of the W/O emulsion explosive composition of the present invention are, for example, hydrogenated castor oil lauric acid monoester, hydrogenated castor oil Hydrogenated castor oil fatty acid esters (fatty acid residues are branched (including body)
and polyoxyethylene (2) hydrogenated castor oil stearic acid mono(di,tri) ester, polyoxyethylene hydrogenated castor oil oleic acid mono(di,tri) ester, polyoxypropylene (6) hydrogenated castor oil oleic acid mono(di, tri) ester, , tri) ester, polyoxyethylene (4) hydrogenated castor oil linolenic acid mono (di, tri) ester, polyoxypropylene (10) hydrogenated castor oil erucic acid mono (di, tri) ester, polyoxyethylene (10) hydrogenated Polyoxyalkylene hydrogenated castor oil fatty acid esters (fatty acid residues also include branched products) such as castor oil lauric acid mono(di,tri)ester. [In the formula, one X represents RCO-- or at least one RCO(O,R') _n-- , and the remainder represents a hydrogen atom. However, R is C _o H _2o+1 , C _o H _2o-1 , C _o
H _2o-3 , C _o H _2o-5 , R' is -CH ₂ -CH ₂ - or

[Formula], n is 9 to 24, and m is 2 to 20] These emulsifiers are used alone or as a mixture of two or more. The amount of emulsifier added is generally 0.1%.
~5%. Preferably it is 0.5% to 4%. If these various emulsifiers are less than 0.1%, W/O
The stability of the detonation sensitivity of the type emulsion explosive composition over time at small diameters and low temperatures is poor, and if it exceeds 5%, the oxygen balance becomes poor, resulting in poor explosiveness and aftergassing, which is also disadvantageous from an economic point of view. Further, the W/O type emulsion explosive composition of the present invention has a temporary specific gravity of 0.80 to 1.35 by using a temporary specific gravity adjusting agent.
(preferably adjusted to 1.00 to 1.15). The temporary specific gravity adjusting agent is a micro hollow sphere or a micro bubble, and the micro hollow sphere is obtained from, for example, glass, alumina, shale, shirasu, silica, volcanic rock, sodium silicate, borax, nacre, obsidian, etc. These include inorganic micro hollow spheres, pitch, carbonaceous micro hollow spheres obtained from coal, etc., synthetic resin micro hollow spheres obtained from phenolic resin, polyvinylidene chloride, epoxy resin, urea resin, etc. The spheres may be used alone or as a mixture of two or more. The amount of micro hollow spheres is generally 0.1
~10%. Microbubbles are, for example, microbubbles obtained by foaming a chemical foaming agent, or microbubbles obtained by mechanically blowing air or other gas during or after the formation of a W/O emulsion. Air bubbles, etc. Chemical blowing agents are, for example, inorganic chemical blowing agents such as alkali metal boron hydrides, those using a combination of sodium nitrite and urea, or N,N'-dinitrosopentamethylenetetramine, azodicarboxylic acid amide, azo These include organic chemical blowing agents such as bisisobutyronitrile. These chemical blowing agents may be used alone or as a mixture of two or more. The amount of chemical blowing agent added is generally 0.01% to 2%. However, regarding the temporary specific gravity adjusting agent, the temporary specific gravity of the micro hollow spheres is less than 0.1%, the chemical blowing agent is less than 0.01%, or the W/O type emulsion explosive composition is
If the amount of air or other gas exceeds 1.35, the detonation sensitivity will be poor and even if the explosion occurs, the detonation velocity will be low. If the micro hollow spheres exceed 10%, or if the chemical blowing agent exceeds 2%, or if the amount of air or other gas is such that the tentative specific gravity of the W/O emulsion explosive composition is less than 0.80. Although the detonation sensitivity is good, the detonation speed is low, so the power is small. The method for producing the W/O emulsion explosive composition of the present invention is, for example, as follows. That is, an oxidizing agent aqueous solution is obtained by dissolving ammonium nitrate or a mixture of ammonium nitrate and other inorganic oxidizing acid salts in water at about 80°C to 90°C. On the other hand, the emulsifier defined in the present invention and fuel oil and/or waxes are heated at 80°C to 90°C.
A mixture (hereinafter abbreviated as plasticizer mixture) is obtained by melt-mixing the mixture. Next, first put the combustible mixture in a heat-retainable container with a certain volume, and mix and stir for about 5 minutes at about 1600 rpm using a commonly used propeller blade stirrer while gradually adding the oxidizing agent aqueous solution. Obtain a W/O emulsion at 85°C. Next, a W/O emulsion explosive composition is obtained by mixing micro hollow spheres or a chemical blowing agent into the W/O emulsion using a vertical mixer at about 30 rpm. In addition, when containing microbubbles made of a gas such as air instead of microbubbles made of microhollow spheres or a chemical blowing agent, it is possible to incorporate gas such as air into the W/O type emulsion while stirring. A W/O emulsion explosive composition is obtained. Next, the W/O type emulsion explosive composition of the present invention will be specifically explained with reference to Examples and Comparative Examples. Note that all parts and percentages in each example are based on weight. Example 1 A W/O type emulsion explosive composition having the formulation shown in Table 1 was manufactured as follows. First, 381.5 parts (76.30%) of ammonium nitrate and 22.85 parts (4.75%) of sodium nitrate were added to 55.25 parts (11.05%) of water and dissolved by heating to obtain an oxidizing agent aqueous solution at about 85°C. On the other hand, hydrogenated castor oil lauric acid monoester defined in the present invention
A mixture of 8.75 parts (1.75%) and 17.05 parts (3.41%) of unrefined microcrystalline wax was heated and melted to obtain a combustible mixture at about 85°C. Next, first put the combustible agent mixture in a heat-insulating container, then gradually add the oxidizing agent aqueous solution and mix and stir for 5 minutes at about 1600 rpm using a propeller blade stirrer to reach about 85℃. A W/O type emulsion was obtained. Next, a W/O emulsion explosive composition was prepared by mixing 14.60 parts (2.92%) of glass micro hollow spheres with an average particle size of 75μ into the W/O emulsion using a vertical mixer at approximately 30 rpm. Obtained. This W/O type emulsion explosive composition was molded to have a diameter of 25 mm, a length of approximately 180 mm, and a drug amount of 100 gr, and was subjected to various performance tests as a medicine package wrapped in viscose-treated paper. Performance tests included (a) measurement of provisional specific gravity one day after production, and (b) repeated temperature cycles in which the sample cartridge was kept at 60℃ for 24 hours and then kept at -15℃ for 24 hours, with this as one cycle. After conducting a forced deterioration storage test, the number of temperature cycles that can cause a complete detonation when a detonation test is performed at -5℃ using a No. 6 detonator is determined, and the number of temperature cycles is calculated at room temperature
°C) Estimated as the number of months of storage for complete detonation when left unattended (1 temperature cycle described above is approximately 1
It was estimated based on the experimental confirmation that it corresponds to 1 month. ) detonation sensitivity temporal stability test, and
(c) Temporary specific gravity measurements were made during the detonation test described in (b) above.
The results were as shown in Table 1. Examples 2 to 11 A W/O emulsion explosive composition having a composition as shown in Table 1 contains hydrogenated castor oil oleate monoester and hydrogenated castor oil linole instead of hydrogenated castor oil lauric acid monoester in Example 1. Acid monoester, polyoxyethylene (2) hydrogenated castor oil isostearic acid diester, polyoxyethylene
(4) Hydrogenated castor oil oleate triester, polyoxyethylene (4) Hydrogenated castor oil linoleate triester, polyoxypropylene (6) Hydrogenated castor oil oleate diester, polyoxypropylene (10) Hydrogenated castor oil erucate diester , polyoxypropylene (10), hydrogenated castor oil erucic acid triester, and a mixture thereof. Sample cartridges were prepared from these W/O emulsion explosive compositions in the same manner as described in Example 1, and performance tests were conducted on the same items. The results were as shown in Table 1. Example 12 A W/O emulsion explosive composition having the composition shown in Table 1 was prepared as in Example 1 except that N,N'-dinitrosopentamethylenetetramine was used instead of the glass micro hollow spheres. Produced according to Example 1. A sample cartridge was prepared from this W/O emulsion explosive composition in the same manner as described in Example 1, and this sample cartridge was heated in a constant temperature bath at approximately 50°C for 2 hours to blend. Chemical blowing agent (N,
The same performance tests as in Example 1 were conducted on a product whose temporary specific gravity was adjusted by decomposing and foaming N'-dinitrosopentamethylenetetramine. The results were as shown in Table 1. Example 13 A W/O type emulsion explosive composition having the formulation shown in Table 1 was produced by the following method. That is, first, a W/O type emulsion was obtained according to Example 1. Next, while blowing air into the above-mentioned W/O type emulsion through a thin nozzle, mixing and stirring was performed at approximately 1600 rpm for 2 minutes using a propeller blade type stirrer to introduce microbubbles of air. An O-type emulsion explosive composition was obtained. Sample cartridges were prepared from this W/O emulsion explosive composition in the same manner as described in Example 1, and performance tests were conducted on the same items. The results were as shown in Table 1. Comparative Examples 1 to 8 W/O emulsion explosive compositions having the formulations shown in Table 2 were produced according to Example 1.
This W/O type emulsion explosive composition was prepared in Example 1.
A sample drug package was prepared using the same method as described in 2012, and performance tests were conducted on the same items. The results were as shown in Table 2. Comparative Examples 9 and 10 W/O emulsion explosive compositions having the formulations shown in Table 2 were produced according to Examples 12 and 13. Sample cartridges were prepared from this W/O emulsion explosive composition in the same manner as described in Example 1, and performance tests were conducted on the same items.
The results were as shown in Table 2.

【table】

【table】

[Table] Examples of emulsifiers defined in the present invention include hydrogenated castor oil lauric acid monoester, hydrogenated castor oil oleic acid monoester, hydrogenated castor oil linoleic acid monoester, polyoxyethylene (2) hydrogenated castor oil isostearic acid diester, and polyoxyethylene (2) hydrogenated castor oil isostearic acid diester. Ethylene(4)
Hydrogenated castor oil oleic acid triester, polyoxyethylene (4) hydrogenated castor oil linoleic acid triester, polyoxypropylene (6) hydrogenated castor oil oleic acid diester, polyoxypropylene (10) hydrogenated castor oil erucic acid diester and polyoxy W/O emulsion explosive composition containing propylene (10) hydrogenated castor oil erucic acid triester (Example 1)
In the case of ~9), the number of months for complete detonation storage at -5°C using a No. 6 detonator was 22 to 27 months. On the other hand, in the case of W/O type emulsion explosive compositions containing known emulsifiers (Comparative Examples 1 to 7), the period was 6 to 19 months. In addition, a W/O emulsion explosive composition containing 2.50% of sodium nitrate and ammonium nitrate as inorganic oxide salts other than ammonium nitrate, liquid paraffin as a combustible agent, silica micro hollow spheres as a bubble retaining agent, and sorbitan monooleate as an emulsifier. In the case of (Comparative Example 8), the storage period for complete detonation at -5℃ using a No. 6 detonator was 24 months, but polyoxyethylene (2) hydrogenated castor oil was used as the emulsifier specified in the present invention. The life of the W/O emulsion explosive composition (Example 10) containing 2.50% isostearic acid diester was 29 months. In addition, the emulsifiers specified in the present invention include hydrogenated castor oil oleic acid monoester (0.80%), polyoxyethylene (4) hydrogenated castor oil oleic acid triester (0.80%), and polyoxypropylene (10) hydrogenated castor oil erucic acid. W/O emulsion explosive composition blended with triester (0.90%) (Example
11), it was 30 months. In addition, a W/O was prepared in which the tentative specific gravity was adjusted by adding 0.20% N,N'-dinitrosopentamethylenetetramine as a chemical blowing agent without adding a bubble retaining agent, and adding 1.80% sorbitan monooleate as an emulsifier. In the case of the type emulsion explosive composition (Comparative Example 9), the storage period for complete detonation at -5°C using a No. 6 detonator was 14 months, but the composition of the present invention was used instead of sorbitan monooleate. The life of the W/O emulsion explosive composition (Example 12) containing 1.80% of the specified polyoxyethylene (2) hydrogenated castor oil isostearate diester was 19 months. In addition, a W/O emulsion explosive composition in which the tentative specific gravity was adjusted by mechanically introducing microbubbles without adding a bubble retaining agent, and 1.80% of sorbitan monoolefinic acid ester was added as an emulsifier (Comparative Example 10)
In this case, the storage period for complete detonation at -5℃ using a No. 6 detonator was 13 months, but polyoxyethylene (2) cured according to the present invention was used instead of sorbitan monooleate. The life of the W/O emulsion explosive composition containing 1.80% castor oil isostearic acid diester (Example 13) was 20 months. As explained above based on each Example and Comparative Example, W/
The O-type emulsion explosive composition has significantly improved stability over time in detonation sensitivity at small diameters (25 mm diameter) and low temperatures compared to W/O-type emulsion explosive compositions containing conventional emulsifiers. .

Claims (1)

[Scope of Claims] 1. (a) a dispersed phase of an oxidizing agent aqueous solution consisting of ammonium nitrate or ammonium nitrate and other inorganic oxide salts, and (b) water, and (c) a continuous combustible material consisting of fuel oil and/or waxes. phase, (d) the following general formula [In the formula, one X represents RCO- or at least one represents RCO(O,R') _n- , and the remainder represents a hydrogen atom. However, R is C _o H _2o+1 , C _o H _2o-1 , C _o
H _2o-3 , C _o H _2o-5 , R' is -CH ₂ -CH ₂ - or [Formula], n is 9 to 24, and m is 2 to 20] 1. A water-in-oil emulsion explosive composition, characterized in that it contains an emulsifier consisting of one or more of the following: and (e) microscopic hollow spheres or microbubbles.