JPH0210797B2 - - 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,
This invention relates to a W/O emulsion explosive composition that has improved stability over time of detonation sensitivity and dead pressure resistance at small diameters (25 mm) and low temperatures. 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 sensitizers such as perchlorates and chlorates of ammonium or alkali metals. Most of the bombs contained sensitive oxidizers (hereinafter abbreviated as auxiliary sensitive substances) to improve 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, several W/O emulsion explosive compositions have been disclosed that do not contain any of the above-mentioned sensitive substances or auxiliary sensitive substances and have improved detonation sensitivity in small diameters (capable of being detonated by detonators). For example, according to US Pat. No. 4,110,134,
As an emulsifier, sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene ether, polyoxyalkylene oleate, polyoxyalkylene laurate,
Contains phosphoric acid oleate, substituted oxazoline, and phosphoric acid ester, and contains glass microballoon as a bubble retaining agent. The diameter of the drug is approximately 1.25 inches (31.8 mm), and it reaches its peak in a No. 6 detonator 18 to 24 hours after manufacture. Completely explodes to a tentative specific gravity of 1.25 (drug temperature 21.1
℃～26.7℃). Further, according to US Pat. No. 4,149,917, emulsifiers include sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene (4) lauryl ether, polyoxyethylene (2) ether,
Contains polyoxyethylene (2) stearyl ether, polyoxyalkylene oleate, polyoxyalkylene laurate, phosphoric oleate, substituted oxazoline, phosphoric ester, and mixtures thereof (however, the numbers in parentheses are (indicates the number of added moles of ethylene oxide),
The tentative specific gravity was adjusted to 0.95 using microbubbles without containing a bubble-retaining substance, and the diameter of the gun was 1.25 inches (31.8 mm), and it was completely detonated with a No. 6 detonator even two months after production (drug temperature 21.1°C). It is stated that even after 8 months, a No. 8 detonator will cause a complete explosion (drug temperature 21.1℃). Furthermore, according to JP-A No. 55-75993, No. 55-75994, and No. 55-75995, a W/O emulsion explosive composition containing an imidazoline derivative, a mercaptan, and an oxyethylene oxypropylene block copolymer as an emulsifier is disclosed. Even after 30 temperature cycles (one cycle of 4 hours at 0°C and 7 hours at 40°C) without adding any sensitive substances or auxiliary sensitive substances, the product remained at No. 6 at -10°C to -20°C. Completely detonated with a detonator. However, the W/O emulsion explosive composition using the emulsifier described in the above-mentioned US patent specification and published patent application was prepared by the inventors at room temperature (10°C to 30°C).
°C) Temperature cycle test (60 °C) that reflects well over time
After one cycle of 24 hours at -15℃ and 24 hours at -5℃
It is detonated with No. 6 detonator. One cycle corresponds to approximately one month of aging at room temperature. ), it was 6 to 26 cycles (6 to 26 months), and in terms of stability over time, it was somewhat satisfactory considering the usage situation in Japan. However, since W/O emulsion explosives are inherently thermodynamically unstable, they are destroyed by many factors other than time, and the detonation sensitivity decreases with the degree of detonation, eventually leading to the detonator not detonating. up to. Among these, the most problematic phenomenon is the non-explosion phenomenon (generally called the "dead pressure phenomenon"), which is caused by the destruction of the emulsion form due to the action of detonation waves and combustion gas from adjacent holes.
It is called. ). In that sense, the temperature cycle test mentioned above requires 6 to 26 cycles (6 to 26 months).
However, considering the stability of the W/O emulsion form and the above-mentioned non-explosion phenomenon (dead pressure phenomenon), it is still insufficient, and it is necessary to use a smaller diameter (25 mm diameter) and lower detonation sensitivity at low temperatures. A W/O emulsion with strong resistance to dead pressure and stability over time has been desired. The inventors of the present invention have carried out intensive research over a long period of time while taking into account the above-mentioned problems, and as a result, a W/O type emulsion explosive composition obtained by using a new specific emulsifier is as follows: The present invention was completed after it was found that the emulsifier has better performance than conventionally known emulsifiers in terms of stability over time of detonation sensitivity and dead pressure resistance at small diameters and low temperatures. That is, the W/O emulsion explosive composition of the present invention comprises a dispersed phase of an oxidizing agent aqueous solution consisting of ammonium nitrate or ammonium nitrate and other inorganic oxide salts and water, and a continuous phase of a combustible substance consisting of fuel oil and/or waxes. , an emulsifier, and a water-in-oil emulsion explosive composition comprising micro hollow spheres or microbubbles, in which the emulsifier contains a polymerized fatty acid and a mixed fatty acid of fatty acids, and a polyhydric alcohol or a polyoxyalkylene polyhydric alcohol (hereinafter referred to as (polyoxyalkylene)). This is a water-in-oil emulsion explosive composition characterized by being an ester compound with a polyhydric alcohol (abbreviated as polyhydric alcohol). 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. Also, alkali metal or alkaline earth metal perchlorates,
An auxiliary sensitizing substance such as chlorate or a sensitizing substance such as monomethylamine nitrate is not an essential component in terms of stability of detonation sensitivity over time and resistance to dead pressure, but may be blended. These inorganic oxidized salts are 1
Use as a seed or a mixture of two or more. The amount of ammonium nitrate is generally 48% to 94.7% of the total.
(on a weight basis, the same applies hereinafter), and 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 minimum 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 minimum dissolution temperature in water can be lowered, so explosiveness and manufacturability can be improved, but the amount exceeds 40%. This increases the amount of solid residue after the explosion, resulting in lower power and disadvantages in terms of economy. Note that the amount of water used in the oxidizing agent aqueous solution is generally 5% to 25%. If it is less than 5%, the minimum 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%, the minimum melting temperature of ammonium nitrate or ammonium nitrate and other inorganic oxide salts will be lowered, so productivity will be improved, but the amount of gas produced after the explosion, the amount of fuel, etc. will be reduced, resulting in poor detonation sensitivity.
Power is 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 oils,
Lubricants, liquid paraffin, etc. and hydrocarbon derivatives,
For example, nitrohydrocarbons. Waxes include microcrystalline wax derived from petroleum, petrolatum, paraffin wax, etc., mineral waxes such as montan wax and osokerite, animal waxes such as spermaceti wax, and insect waxes such as beeswax. It is. 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 new specific emulsifier that can be used in the W/O emulsion explosive composition of the present invention is prepared by mixing and heating a polymerized fatty acid, a mixed fatty acid consisting of a fatty acid, and a (polyoxyalkylene) polyhydric alcohol, It is an ester compound obtained through a dehydration reaction in which water produced by the reaction is distilled off at a temperature of °C. The polymerized fatty acids that are the raw materials for that particular emulsifier are:
For example, unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, tall oil fatty acids, soybean oil fatty acids, and linseed oil fatty acids, and fatty acids containing unsaturated fatty acids such as corn oil fatty acids, olive oil fatty acids, rice bran oil fatty acids, and safflower oil fatty acids. Polymerized fatty acids obtained by intermolecular polymerization reaction of unsaturated fatty acids in It is a polymerized fatty acid obtained by further decomposing and separating the polymerized oil. The fatty acids that are raw materials for the specific emulsifier include, for example, lauric acid, palmitic acid, stearic acid,
Saturated and unsaturated fatty acids such as isostearic acid, behenic acid, oleic acid and linoleic acid, corn oil fatty acid, olive oil fatty acid, rice bran oil fatty acid, and safflower oil fatty acid. Examples of (polyoxyalkylene) polyhydric alcohols that are raw materials for the specific emulsifier include (polyoxyalkylene) sorbitan, (polyoxyalkylene) propylene glycol, (polyoxyalkylene) glycerol, and (polyoxyalkylene) glycol. (polyoxyalkylene) polyhydric alcohol. Mixed fatty acids consisting of polymerized fatty acids and fatty acids are
The polymerized fatty acid may be a mixture obtained from the two methods described above. However, the ratio of polymerized fatty acid to fatty acid is 9:1 to 0.2:9.8 by weight. The proportion of polymerized fatty acids
If it exceeds 90%, the emulsification rate will deteriorate and stable W/O
Unfavorable because it does not form a mold emulsion;
Further, if the proportion of polymerized fatty acid is less than 2%, sufficient improvement in the stability over time of detonation sensitivity and dead pressure resistance at small diameters and low temperatures, which are the objectives of the present invention, is not achieved, which is not preferable. These new specific emulsifiers may be used alone or as a mixture of two or more. The amount of emulsifier added is generally 0.1% to 7%. Preferably 0.5% to 4
%. If these various emulsifiers are less than 0.1%, W/O
The type emulsion explosive composition has poor detonation sensitivity over time stability and dead pressure resistance at small diameters and low temperatures;
If it exceeds 7%, the oxygen balance becomes poor, resulting in poor explosiveness and aftergassing, which is also disadvantageous in terms of economy. 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 1.20). 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 sand, volcanic rock, sodium silicate, borax, nacre, obsidian, etc. Inorganic micro hollow spheres, carbonaceous micro hollow spheres obtained from pitch, coal, etc., synthetic resin micro hollow spheres obtained from phenolic resins, polyvinylidene chloride, epoxy resins, urea resins, 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 blowing 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 include, 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 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 microhollow 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. The detonation sensitivity is good, but 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 90°C to 95°C. On the other hand, the emulsifier defined in the present invention and fuel oil and/or waxes are heated at 90°C to 95°C.
A mixture (hereinafter abbreviated as combustible mixture) is obtained by melting and mixing at °C. 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 ppm using a commonly used propeller blade stirrer while gradually adding the oxidizing agent aqueous solution. Obtain a W/O type emulsion at 90°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 gas such as air instead of microbubbles caused by microscopic hollow spheres or a chemical blowing agent, W/O emulsion can be mixed by stirring while blowing gas such as air into the W/O type emulsion. /O type 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 (4.57%) 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 90°C. On the other hand, 8.75 parts (1.75%) of sorbitan (polymerized oleic acid/1/8 oleic acid) monoester specified in the present invention and microcrystalline wax (wax rex)
602 (manufactured by Mobil Oil) and 17.05 parts (3.41%) of the mixture was heated and melted to obtain a combustible mixture at about 90°C. Next, first put the combustible mixture in a heat-insulating container, then gradually add the oxidizing agent aqueous solution and mix and stir for 5 minutes at about 1,600 rpm using a propeller blade stirrer to bring the mixture to about 90°C. A W/O type emulsion was obtained. Next, 14.60 parts (2.92%) of glass micro hollow spheres (B15/250; manufactured by 3M) with an average particle size of 75μ were added to the above W/O emulsion using a vertical mixer to approx.
A W/O emulsion explosive composition was obtained by mixing at 30 rpm. The sorbitan (polymerized oleic acid/oleic acid 1/8) monoester used here was prepared by mixing sorbitan and a mixture of polymerized oleic acid and oleic acid in a weight ratio of 1:8, heating the mixture, and heating the mixture at 150°C. This is a compound obtained by dehydration reaction. The W/O type emulsion explosive composition obtained as described above was molded to have a diameter of 25 mm, a length of approximately 170 mm, and a drug amount of 100 gr, and was packaged in viscose-treated paper and subjected to various performance tests. provided. Performance tests include (a) measurement of provisional specific gravity one day after production, and (b)
After conducting a forced deterioration storage test in which the sample cartridge was kept at 60°C for 24 hours and then kept at -15°C for 24 hours, this temperature cycle was repeated, using a No. 6 detonator. Determine the number of temperature cycles that can cause a complete explosion when performing an explosion test at 5℃,
The number of such cycles was estimated as the number of months of storage for complete explosion when stored at room temperature (10 to 30°C) (estimated from the fact that it was experimentally confirmed that one temperature cycle corresponds to approximately one month when stored at room temperature). ) Detonation sensitivity temporal stability test, (c) Provisional specific gravity measurement during the detonation test in (b) above, and (d) A medicine package (drug amount 100g) wrapped in viscose-treated paper and 50g dynamite were separated at a certain distance. After completely detonating 50g of dynamite, the test agent was detonated one second after hanging at a distance, and a dead pressure resistance test was conducted by converting the maximum underwater pressure (Kg/cm ² ) for complete detonation from the minimum distance for complete detonation. . 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 contained sorbitan (polymerized linoleic acid) in place of the sorbitan (polymerized oleic acid/oleic acid 1/8) monoester of Example 1. /stearic acid 1/6) diester, propylene glycol (polymerized tall oil fatty acid/linoleic acid 1/4) monoester, glycerol (polymerized linseed oil fatty acid/
Behenic acid 1/2) monoester, sorbitan (polymerized soybean oil fatty acid/oleic acid 1/1) diester, ethylene glycol (polymerized fish oil fatty acid/linolenic acid 2/1) monoester, polyoxyethylene (4) sorbitan (polymerized safflower oil fatty acid/corn oil fatty acid 4/1) diester (however, the number in parentheses following polyoxyethylene indicates the number of moles of ethylene oxide added. The same applies hereinafter), polyoxypropylene (2) glycerol (polymerized cottonseed oil Fatty acid/olive oil fatty acid 6/1) monoester,
Example 1 with the formulation compositions of Examples 2 to 11 shown in Table 1 except that polyoxyethylene (2) glycol (polymerized oleic acid/rice bran oil fatty acid 8/1) monoester and mixtures thereof were used. Manufactured in accordance with The various emulsifiers are obtained by dehydrating the polyhydric alcohol, the polymerized fatty acid, and the mixture of fatty acids. These W/
A sample cartridge was prepared using the O-type emulsion explosive composition in the same manner as described in Example 1,
Performance tests were conducted on the same items. The result is the first
It was as shown in the table. 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 in place 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 the sample cartridge was heated in a constant temperature bath at approximately 50°C for 2 hours to blend. The same performance tests as in Example 1 were conducted on a chemical blowing agent (N,N'-dinitrosopentamethylenetetramine) which was decomposed and foamed to adjust the tentative specific gravity. 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 W/O type emulsion through a thin nozzle, the mixture is stirred for 2 minutes at approximately 1600 rpm using a propeller blade stirrer to introduce microbubbles of air. A 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 19 W/ of the compounding composition shown in Tables 2 and 3
An O-type emulsion explosive composition was produced according to Example 1. 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. Comparative Examples 20 and 21 W/O emulsion explosive compositions having the formulation shown in Table 3 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] Shows the number of moles of propylene oxide added.

【table】

【table】

【table】

[Table] As emulsifiers defined in the present invention, sorbitan (polymerized oleic acid/oleic acid 1/8) monoester, sorbitan (polymerized linoleic acid/stearic acid 1/6) diester, propylene glycol (polymerized tall oil fatty acid/linoleic acid) 1/4) Monoester, glycerol (polymerized linseed oil fatty acid/
Behenic acid 1/2) monoester, sorbitan (polymerized soybean oil fatty acid/oleic acid 1/1) diester, ethylene glycol (polymerized fish oil fatty acid/linolenic acid 2/1) monoester, polyoxyethylene (4) sorbitan (polymerized safflower oil fatty acid/corn oil fatty acid 4/1) diester, polyoxypropylene (2) glycerol (polymerized cottonseed oil fatty acid/olive oil fatty acid 6/1) monoester and polyoxyethylene (2) glycol (polymerized oleic acid/rice bran oil) W/O emulsion explosive compositions containing fatty acid 8/1) monoesters (Example 1 to
In the case of 9), the storage period for complete explosion at -50℃ using a No. 6 detonator is 36 to 39 months, and the maximum pressure for complete explosion is 97
It was between Kg/cm ² and 124Kg/cm ² . On the other hand, in the case of W/O type emulsion explosive compositions containing known emulsifiers (Comparative Examples 1 to 9), the storage time for complete detonation at -5°C using a No. 6 detonator is 6 months to 26 months. The maximum pressure was 40Kg/cm ² to 75Kg/cm ² . In addition, in the case of W/O emulsion explosive compositions (Comparative Examples 10 to 18) in which an ester compound of a normal fatty acid and a polyhydric alcohol which is not blended with the polymerized fatty acid specified in the present invention is blended as an emulsifier, 6 The number of complete explosions stored at -5℃ using a No. 1 detonator is 9 months to 19
The maximum pressure for complete explosion was 40Kg/cm ² to 75Kg/cm ² . In addition, sodium nitrate and calcium nitrate are used as inorganic oxide salts other than ammonium nitrate, liquid paraffin is used as a combustible agent, silica micro hollow spheres (Silica Balloon NL; manufactured by Kushiro Coal Dry Distillation) are used as a bubble retaining agent, and 2.50% sorbitan stearate diester is used as an emulsifier. In the case of the blended W/O emulsion explosive composition (Comparative Example 19), the storage period for complete detonation at -5°C using a No. 6 detonator is 28 months, and the maximum pressure for complete detonation is 97 Kg/cm ² , W/O containing 2.50% of sorbitan (polymerized linoleic acid/stearic acid 1/6) diester as an emulsifier defined in the present invention.
That of type emulsion explosive composition (Example 10) is
It took 40 months, and the maximum pressure for complete explosion was 192Kg/cm ² .
Further, as emulsifiers defined in the present invention, sorbitan (polymerized linoleic acid/stearic acid 1/6) diester and sorbitan (polymerized soybean oil fatty acid/oleic acid 1/1) diester are each used at 0.8% and glycerin (polymerized cottonseed oil fatty acid/ Palmitic acid 6/
1) The W/O type emulsion explosive composition (Example 11) containing 0.9% monoester is 42
The maximum detonation pressure was 170Kg/cm ² . In addition, W/ was prepared by adding 0.2% of N,N'-dinitrosopentamecheletetramine as a chemical foaming agent to adjust the tentative specific gravity without adding a bubble retaining agent, and adding 1.80% of sorbitan stearate diester as an emulsifier. O-type emulsion explosive composition (comparative example)
20), the storage period for complete detonation at -5℃ using a No. 6 detonator is 9 months, and the maximum detonation pressure is 38
W/ ^O emulsion explosive composition containing 1.80% of sorbitan (polymerized linoleic acid/stearic acid 1/6) diester specified in the present invention instead of sorbitan stearate diester (example). 12), it took 30 months and the maximum pressure at complete explosion was 79Kg/ ^cm2 . In addition, a W/O emulsion explosive composition (Comparative Example 21) in which the tentative specific gravity was adjusted by mechanically introducing microbubbles without adding a bubble retaining agent, and 1.80% sorbitan stearate diester as an emulsifier was used. In this case, the storage period for complete detonation at −5°C using a No. 6 detonator was 8 months, and the maximum detonation pressure was 33 Kg/cm ² . The W/O emulsion explosive composition (Example 13) containing 1.80% sorbitan (polymerized linoleic acid/stearic acid 1/6) diester as an emulsifier was 33 months, and the maximum pressure for complete detonation was 70 kg/ ^cm2. It was hot. As explained above based on each Example and each Comparative Example, a W/O emulsion explosive containing an emulsifier which is an esterified product of a mixed fatty acid of a polymerized fatty acid and a fatty acid specified in the present invention and a polyhydric alcohol. The composition has significantly improved stability over time of detonation sensitivity and dead pressure resistance at small diameters (25 mm diameter) and low temperatures compared to conventional W/O emulsion explosive compositions containing known emulsifiers. It is something.

Claims (1)

[Scope of Claims] 1. A dispersed phase of an oxidizing agent aqueous solution consisting of ammonium nitrate or ammonium nitrate and other inorganic oxidizing acid salts and water, a continuous phase of a combustible substance consisting of fuel oil and/or waxes, an emulsifier, and micro hollow spheres or In a water-in-oil emulsion explosive composition consisting of microbubbles, the emulsifier contains polymerized fatty acids and fatty acids in a weight ratio of 9:
A water-in-oil emulsion explosive composition, which is an ester compound of a mixed fatty acid having a ratio of 1 to 0.2:9.8 and a polyhydric alcohol or a polyoxyalkylene polyhydric alcohol. 2. The water-in-oil emulsion explosive composition according to claim 1, wherein the proportion of the emulsifier is 0.1 to 7% by weight based on the total weight of the water-in-oil emulsion explosive composition.