JPS6213319B2 - - 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 diglycerol fatty acid esters and/or polyoxyalkylene diglycerol fatty acid esters as emulsifiers, we have achieved performance superior to conventional known emulsifiers in terms of stability over time of detonation sensitivity at small diameters (25 mm diameter) and low temperatures. The present invention relates to a W/O emulsion explosive composition having the following properties. 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 U.S. 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, and 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. Further, 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 oxazoline, phosphoric ester, and mixtures thereof, it is possible to form microbubbles 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). 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 A continuous phase of a combustible agent consisting of waxes, (d) an emulsifier consisting of a specific diglycerol fatty acid ester and/or polyoxyalkylene diglycerol 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 low power. . 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 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 spermaceti 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 content of 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 diglycerol fatty acid ester and polyoxyalkylene diglycerol fatty acid ester which are emulsifiers of the W/O emulsion explosive composition of the present invention are diglycerol fatty acid monoester and polyoxyalkylene fatty acid monoester represented by the following general formulas () and (). Range glycerol fatty acid monoester,
These include diglycerol fatty acid diesters and polyoxyalkylene diglycerol fatty acid diesters. [R=C _o H _2o+1 , C _o H _2o-1 , C _o H _2o-3 , or C _o H
_2o-5 (n=9~24) R'=-CH ₂ CH ₂ - or

[Formula] x, y, z = 0 to 20] [R=CnH _2o+1 , CnH _2o-1 , CnH _2o-3 or CnH _2o-5
(n=9~24) R′=−CH ₂ CH ₂ − or

[Formula] x, y=0 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 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 containing a chemical blowing agent, or by mechanically blowing air or other gas during or after the formation of a W/O emulsion. Microbubbles, 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 bodies 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 80°C to 90°C. On the other hand, the emulsifier defined in the present invention and fuel oil and/or waxes were heated at 80°C to 90°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 rpm using a commonly used propeller blade stirrer while gradually adding the oxidizing agent aqueous solution. Obtain a W/O type 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 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 emulsion explosive composition having the formulation shown in Table 1 was produced 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 85°C. On the other hand, a mixture of 8.75 parts (1.75%) of diglycerol lauric acid monoester specified in the present invention and 17.05 parts (3.41%) of unrefined microcrystalline wax was heated and melted, and the combustible mixture was heated to about 85°C. Obtained. 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°C. 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 test 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 experimental confirmation that it corresponds to 1 month. ), and (c) provisional specific gravity measurements during the detonation test described in (b) above were conducted. 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 diglycerol oleate monoester, diglycerol isostearate monoester, diglycerol isostearate monoester, diglycerol isostearate monoester, Diglycerol oleate diester, diglycerol erucate diester, diglycerol linoleate diester, polyoxyethylene (4) diglycerol stearate diester, polyoxyethylene (4) diglycerol oleate diester, polyoxypropylene (10)
It was produced according to Example 1 except that diglycerol erucate diester and a mixture thereof were used. 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 are 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 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 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 prepared by decomposing and foaming N'-dinitrosopentamethylenetetramine and adjusting its temporary 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-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 are 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 medicine package was prepared using the same method as described in 2012, and performance tests were conducted on the same items. The results are shown in Table 2. Comparative Examples 9 and 10 W/O emulsion explosive compositions having the formulation shown in Table 2 were produced according to Examples 12 and 13. A sample cartridge was 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 are shown in Table 2.

【table】

[Table] Examples of emulsifiers defined in the present invention include diglycerol laurate monoester, diglycerol oleate monoester, diglycerol isostearate diester, diglycerol oleate diester, diglycerol erucate diester,
1.75% each of diglycerol linoleate diester, polyoxyethylene (4) diglycerol stearate diester, polyoxyethylene (4) diglycerol oleate diester, and polyoxypropylene (10) diglycerol erucate diester
In the case of the blended W/O emulsion explosive compositions (Examples 1 to 9), the storage periods for complete detonation at -5°C using a No. 6 detonator were 22 months, 27 months, and 23 months, respectively.
29 months, 25 months, 26 months, 24 months, 23 months and 24 months. On the other hand, in the case of W/O type emulsion explosive compositions (Comparative Examples 1 to 7) containing known emulsifiers, the period was 6 to 18 months. Also, a W/O emulsion explosive composition containing sodium nitrate and calcium 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 2.50% of sorbitan monooleate as an emulsifier. In the case of Comparative Example 8, the storage period for complete detonation at -5°C using a No. 6 detonator was 24 months; Blended W/O emulsion explosive composition (Example 10)
In this case, the number of months it could be stored for complete detonation at -5℃ using a No. 6 detonator was 30 months. In addition, a W/O emulsion explosive composition containing 1.25% diglycerol oleate monoester and 1.25% polyoxyethylene (4) diglycerol oleate diester as an emulsifier defined in the present invention (Example
11), the number of months it could be stored for complete detonation at -5℃ using a No. 6 detonator was 32 months. In addition, W/ was prepared by adding 0.20% of N・N'-dinitrosopentamethylenetetramine as a chemical foaming agent to adjust the tentative specific gravity without adding a bubble retaining agent, and adding 1.80% of sorbitan monooleate as an emulsifier. In the case of the O-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 present invention was used instead of sorbitan monooleate. A W/O emulsion explosive composition (Example 12) containing 1.80% diglycerol oleate diester as an emulsifier defined by
The number of months it could be stored for a complete explosion was 20 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 monooleate 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 diglycerol oleate diester was used as an emulsifier specified in the present invention instead of sorbitan monooleate. of
The W/O emulsion explosive composition containing 1.80% (Example 13) could be stored for 19 months for complete detonation at -5°C using a No. 6 detonator. As explained above based on each Example and each Comparative Example, the W/O type emulsion explosive composition blended with the emulsifier specified by the present invention is different from the W/O type emulsion explosive composition blended with the conventional emulsifier. Compared to the previous version, the stability over time of detonation sensitivity at small diameter (25 mm diameter) and low temperature has been greatly improved.

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 agent consisting of fuel oil and/or waxes. Phase, (d) The following general formulas () and () [Formula] [Formula] [In the formula, R=CnH _2o+1 , CnH _2o+1 , CnH _2o-1 ,
CnH _2o-3 or CnH _2o-5 (n = 9 to 24) R' = -CH ₂ CH ₂ - or [Formula] X, Y, Z = 0 to 20] 1. An emulsion-in-oil explosive composition comprising: an emulsifier consisting of one or more oxyalkylene diglycerol fatty acid esters; and (e) micro hollow spheres or microbubbles.