JPH037733A - Pyroxylin-based hollow particle and hydrous explosive composition containing same particle - Google Patents

Abstract

PURPOSE:To obtain the title particles not reducing explosive power, useful as explosive, fireworks, smoking insecticide, etc., having specific particle diameters and a specific gravity, containing a large amount of pyroxylin. CONSTITUTION:The aimed particles containing >=30% pyroxylin and having 5-200mum, preferably 10-150mum average particle diameter and 0.001-0.4g/cc apparent specific gravity is blended with an oxidizing agent, a sharply sensitizing agent, a surfactant and water to give a hydrous explosive composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to hollow particles of nitrified cotton thread used in explosives, fireworks, smoke pesticides, etc., and further relates to a hydrous explosive composition containing the hollow particles of nitrified cotton thread. It is something.

[Conventional technology]

Conventional hydrous explosives contain oxidizing agents, sensitizing agents, thickening agents, cross-linking agents,
A method has been used in which a hydrous explosive composition contains a surfactant, an oil agent, and water as the main components, and further includes small bubbles in the composition to improve detonation characteristics such as detonation sensitivity and detonation propagation.

Nitrified cotton itself has excellent explosive and combustible properties, so it has been widely used as an additive in explosives, but ordinary nitrated cotton is fibrous and cannot be expected to have any effect in containing small bubbles. Ta.

On the other hand, the average particle size of nitrified cotton particles is 10 to 50 μm.
A ball powder or fleet ball having an m1 specific gravity of 1.2 to 1.6 was known. L7 or L7 contained almost no air bubbles in its particles as indicated by its specific gravity, so it was completely insufficient to add to a hydrous explosive to improve its detonation properties.

Various methods are known for this method of including small bubbles and L7. For example, by strongly mechanically treating an explosive composition mixed with a suitable surfactant to form bubbles, by adding a chemical compound that generates a gas, dry wood flour, aluminum, etc. A method in which a dry fine powder such as powder is added and the air adsorbed on the surface of the fine powder forms bubbles, a hollow sphere formed from an inorganic material, or a hollow sphere formed from a synthetic resin or natural resin. ball,
There is a method of forming particles by adding gas-containing particles, such as a multi-cell method or a porous method. As a specific example, U.S. Pat. There is an example of 250 μm glass hollow particles,
U.S. Pat. No. 3,773,573 has a density of 0.
1 g/cm3 or less, average particle size 200 μm or less, especially density 0.05~O, OO5g/cm3, average particle size 2~
There is an example of thermoplastic hollow particles with a diameter of 100 μm, and it is described that they are effective in improving explosion sensitivity under static pressure or in improving explosive power.

However, explosives containing air bubbles have a problem in that during long-term storage, air bubbles are gradually removed from the explosive, resulting in deterioration of detonation properties. On the other hand, in the case of explosives containing hollow particles, it is rare for these particles to escape during storage, but there are problems described below.

As hollow particles, non-flammable inorganic substances such as natural glass, etc.
The use of foamed particles made from materials such as whitebait, fly ash, sodium silicate, borates, or phosphate polymers is disadvantageous because they are completely inert when detonated. In addition, since many inorganic hollow particles are strong, they are difficult to break at low pressures, and the amount of heat supplied by adiabatic compression of the gas within the hollow particles, which serves as the initiator, is small when detonating. There were also problems with sensitivity.

Therefore, hollow particles made from synthetic resins such as olefins, vinyl compounds, polymers or copolymers such as vinylidene chloride, etc., which act as L2 with combustible agents in the event of an explosion, or a mixture of these are used. Attempts have been made to improve detonation characteristics such as detonation speed and combustion efficiency without reducing power by blending them.

However, although the shell walls of these synthetic resin hollow particles are flammable, they are flame retardant.
Although it was improved compared to inorganic hollow particles 7, it was disadvantageous in terms of power.

[Problems to be Solved by the Invention] Conventional nitrified cotton ball powder or Fleet Ball as a sensitizing agent does not contain air bubbles in the particles, so it cannot improve the detonation characteristics of hydrous explosives, and it is difficult to improve the detonation properties of hydrous explosives, and it is difficult to improve the detonation properties of hydrous explosives. Since the system hollow fine particles are non-flammable or flame-retardant, they do not participate in the explosive reaction, resulting in a disadvantage in that they reduce the power of the hydrous explosive.

[Means to solve the problem]

In view of the above-mentioned problems, the inventors of the present invention have conducted extensive research and have developed hollow particles that do not reduce explosive power by using nitrified cotton thread hollow particles containing easily flammable nitrified cotton as the material for the shell wall of the hollow particles. The present invention was completed based on the discovery that the present invention can be obtained.

That is, the present invention relates to nitrified cotton-based hollow particles and hydrous explosives containing the same, and more particularly, the present invention relates to nitrified cotton-based hollow particles and hydrous explosives containing the same, and more specifically, particles containing nitrified cotton in an amount of 30% or more by weight, an average particle diameter of 5 to 200 μm, and an apparent specific gravity of 0. The present invention relates to nitrified cotton yarn hollow particles having a weight of .001 to 0.4 g/cc and a hydrous explosive composition containing the same. The average particle diameter here refers to a number-averaged value obtained by measuring a sample using an electron microscope. Further, the apparent specific gravity refers to the value obtained by weighing 100 cc of a sample into a 100 cc graduated cylinder, measuring the weight, and dividing the weight by 100.

The nitrified cotton contained in the nitrified cotton yarn hollow particles of the present invention is obtained by treating cellulose raw materials such as pulp or linter with a mixture of sulfuric acid/nitric acid, etc., and has a nitrogen content of 10 to 14% and a degree of polymerization. 30 to 1000 can be used.

The nitrified cotton yarn hollow particles of the present invention are compatible with other synthetic resins, piriforms, S-containing solvents, stabilizers, protective colloids, and surfactants due to the stability of nitrified cotton, the needs for producing nitrified cotton yarn hollow particles, and hydrous explosives. It may also contain auxiliary agents such as agents and lubricants, or some of the components of the explosive composition.

It is essential that the nitrified cotton yarn hollow particles of the present invention contain 30% or more of nitrified cotton by weight. If the amount of nitrified cotton in the nitrified cotton yarn hollow particles is less than this, the mechanical strength of the particles will be weak and the combustibility will also be insufficient.

The method for preparing the nitrified cotton yarn hollow particles of the present invention is not limited in any way, but, for example, they can be prepared by heating particles of nitrified cotton yarn encapsulating a low-boiling point organic solvent or water. In preparing the nitrified cotton thread hollow particles of the present invention, a method of preparing the nitrified cotton thread particles by heating water-encapsulating nitrified cotton thread particles is preferred. In the method of preparing particles of nitrified cotton yarn encapsulating a low-boiling point organic solvent by heating, the particle size becomes too small;
Moreover, the appearance has a high relative importance. An example of the method for preparing the nitrified cotton yarn hollow particles of the present invention is shown below. Nitrified cotton or nitrified cotton and the aforementioned stabilizers, protective colloids, surfactants, lubricants, and other auxiliaries, or some of the components of the explosive composition are dissolved in an organic solvent such as ethyl acetate or isopropyl acetate, and a small amount of A W2O type dispersion is prepared by adding with stirring a quantity of water. Further, the W10 type dispersion obtained here is added to a large amount of water while stirring to prepare a (Wlo)/W type dispersion, which is filtered and dried to obtain the nitrified cotton fiber hollow particles of the present invention. I can do it. Here, the average particle diameter of the present invention is 5 to 20
In order to obtain nitrified cotton yarn hollow particles with a diameter of 0 μm and an apparent specific gravity of 0.001 to 0.4, the amount of water when preparing a W2O type dispersion must be 5 to 30% by weight of the amount of organic solvent. It is preferable that

If the amount is less than this, the apparent specific gravity of the hollow particles of nitrified cotton obtained will be too high, and if it is more than this, the particles will break and particles with a uniform diameter cannot be obtained. Moreover, in drying after filtration, it is preferable that the drying temperature is 60 to 140°C.

If the temperature is lower than this, foaming will be insufficient and the apparent specific gravity will be too high; if the temperature is higher than this, the particles will break due to rapid evaporation of water, making it impossible to obtain particles of uniform size.

The average particle diameter of the nitrified cotton yarn hollow particles of the present invention must be within the range of 5 μm to 2001 Im. If the average particle diameter is larger than 200 μm, dispersion tends to be uneven when mixed into an explosive composition. , it becomes difficult to make a homogeneous explosive, and the detonation characteristics of the explosive become uneven, which is not preferable. If the average particle diameter is 5 μm or less, the effect of its addition will be small. The average particle size of
Particularly preferred are those within the range of μm to 150 μm. The shape of the particles is preferably close to spherical from the viewpoints of homogeneous mixing in explosives, dispersibility, and close packing.

The apparent specific gravity of the nitrified cotton yarn hollow particles of the present invention is 0.001
It is necessary to be within the range of ~0.4 g/cc.

If the apparent specific gravity is greater than 0.4 g/cc, it is undesirable because it is necessary to add a large amount to the explosive composition to increase the explosion sensitivity, and the explosion sensitivity also tends to decrease. . On the other hand, if it is less than 0.001 g/cc, the difference in specific gravity will be too large when added to an explosive composition, making uniform dispersion difficult. LA is not preferred as it may result in poor dispersion.

The blending ratio of the nitrified cotton fiber hollow particles of the present invention to the explosive is determined by taking into account oxygen balance, detonation properties, high potency, manufacturability, etc., but is usually 0.01 to 10% based on the weight of the explosive.
It is blended within the range of weight %.

If the amount of the nitrified cotton yarn hollow particles is less than 0.01% by weight, the detonation sensitivity will be poor, and even if an explosion occurs, the agitation speed will be low or the aftergas will be poor. In addition, the blending amount of nitrified cotton hollow particles was 10
If the weight exceeds the weight, the detonation sensitivity is good, but the detonation velocity is low, so the power is low, and the oxygen balance tends to become negative, resulting in poor aftergassing.

The nitrified cotton yarn hollow particles of the present invention may be added alone to the hydrous explosive, but they can also be used in combination with other known hollow particles.

The oxidizing agent used in the present invention contains ammonium nitrate as a main component, and may contain other inorganic oxidizing agents as necessary. Here, other inorganic oxidizing agents are, for example, alkali metal and alkaline earth metal nitrates such as sodium nitrate and calcium nitrate. In addition, auxiliary sensitive substances such as perchlorates and chlorates of alkali metals and alkaline earth metals are used. These la-free oxidizing agents are used as species or a mixture of two or more. The amount of the inorganic oxidizing agent generally ranges from 20% to 95% by weight of the explosive, and if necessary, other inorganic oxidizing agents may be included in an amount of up to 50% by weight of the total inorganic oxidizing agent including ammonium nitrate. . Further, the particle size of the inorganic oxidizing agent in the present invention is not particularly limited.

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 aftergas. 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 deteriorates, resulting in poor detonation sensitivity.

Regarding the other inorganic oxidizing agents mentioned above, by adding them in small amounts, 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 if the amount exceeds 50% by weight, This increases the amount of solid residue left after the explosion, which reduces the power and makes it economically disadvantageous.

Examples of the sensitizing agent used in the present invention include water-soluble hydrazine nitrate, aliphatic amine nitrate having 1 to 3 carbon atoms, and phenylamine nitrate.

Among these, aliphatic amine nitrates are preferred because they provide explosive properties and long-term stability. Examples of water-soluble aliphatic amine nitrates include methylamine nitrate, ethylamine nitrate, ethanolamine nitrate, propylamine nitrate, and phenylamine nitrate, and as a group thereof, methoxyphenylamine nitrate, 2.4-
Examples include methylphenylamine nitrate, 2,6-methylphenylamine nitrate, and the like. Furthermore, as a sensitizing agent, aluminum flakes may be mixed and used as necessary.

The amount of sensitizing agent added is 5% to 40% by weight of the weight of the explosive.
It is blended within the range of. If it is less than 5% by weight, stable detonator detonation properties and detonation propagation cannot be obtained;
Exceeding this will result in a large negative oxygen balance, which will cause problems with the gas after blasting.

Thickeners used in the present invention include guar gum, low molecular weight guar gum, guar gum derivatives such as hydroxyethyl-modified guar gum, hydroxymethyl-modified guar gum, locust Bing gum, Locus I Pinga 1% derivative, hydrolyzed gum, oxidized gum, It consists of one or a combination of two or more natural or synthetic polymer compounds such as xanthan, polyacrylamide, carboxymethylcellulose, starch, modified starch, and crosslinked starch. Furthermore, antimonates, chromates, borates, etc. are used as crosslinking agents for the above-mentioned thickeners.

The amount of the thickener used in the present invention is 0% of the weight of the explosive.
．． The content is 5 to 6% by weight, and if it is less than 0.5% by weight, the hydrous explosive composition will separate, and if it exceeds 6% by weight, it will be difficult to manufacture. Preferably, it is blended in an amount of 0.9% to 4% by weight.

The surfactant used in the present invention is not particularly limited and includes all conventionally known surfactants. For example, sorbitan fatty acid esters, glycerin fatty acid esters, polyoxyalkylene fatty acid esters, oxazoline derivatives, imidapurine derivatives, phosphoric acid esters, alkali metal and alkaline earth metal salts of fatty acids, -grade, secondary and tertiary amines, Nitrates or acetates of primary, secondary and tertiary amines. These surfactants are used singly or as a mixture of two or more. The amount of surfactant is generally 0.1% by weight of the explosive.
to 8% by weight. Preferably it is 0.5% to 4% by weight. If the content of these various surfactants is less than 0.1% by weight, the stability of the detonation sensitivity over time and dead pressure resistance of the hydrous explosive composition at small diameters and low temperatures will be poor, and if it exceeds 8% by weight, the oxygen balance will deteriorate and an explosion may occur. This results in poor performance and aftergas, which is disadvantageous from an economic point of view.

Examples of the oil used in the present invention include fuel oil and waxes, and fuel oil is a hydrocarbon such as paraffinic hydrocarbon, olefinic hydrocarbon, naphthenic hydrocarbon, aromatic hydrocarbon, saturated or unsaturated hydrocarbon. Saturated hydrocarbons, petroleum, refined mineral oils, lubricants, liquid paraffin, etc. and hydrocarbon derivatives, such as 34 nitrohydrocarbons, etc. In addition, waxes used include microcrystalline wax derived from petroleum, petrolatum paraffin wax, etc., mineral waxes such as montan wax and osikerite, animal waxes such as whale wax, and insect waxes such as beeswax. . These oils are used singly or as a mixture of two or more.

Furthermore, the amount of oil agents added is generally from 0.1% to 10% by weight based on the weight of the explosive. If the oil agent is less than 0.1% by weight, the stability of the explosive composition will be poor, and if it exceeds 10% by weight, the oxygen balance will be too poor, resulting in poor explosiveness and aftergassing.

Note that the amount of water added is, in principle, 5% to 25% by weight of the weight of the explosive. If it is less than 5% by weight, the minimum melting temperature of ammonium nitrate or ammonium nitrate and other inorganic oxidizing agents will become too high, resulting in poor productivity and poor detonation sensitivity due to poor explosive reactivity. If it exceeds 25% by weight, the minimum melting temperature of ammonium nitrate or ammonium nitrate and other inorganic oxidizing agents will be lowered, so productivity will be improved, but the amount of gas produced and the amount of heat after detonation will be reduced, resulting in poor detonation sensitivity. Power is low.

The hydrous explosive targeted by the present invention is a conventionally known fully hydrous explosive containing hollow particles. For example, slurry explosives and water-in-oil emulsion explosives are targeted.

〔Example〕

Next, the present invention will be explained with reference to Examples, but the present invention is not limited to these Examples, and it goes without saying that many modifications can be made without departing from the spirit of the invention. It should be noted that all parts and percentages are by weight unless otherwise specified.

Example 1 3.7 parts of nitrified cotton [manufactured by Asahi Kasei Kogyo ■, trade name: HIG60, nitrification line -70%] was dissolved in 48.3 parts of isopropyl acetate. Next, 8 parts of water was added to the above, and at the same time, the mixture was strongly stirred using a propeller type stirrer to form a W2O type suspension. Furthermore, 250 parts of an aqueous solution containing 1% gelatin was added to 40 parts.
While maintaining the temperature at °C, the W10 type suspension described above was quickly added thereto, and the mixture was stirred at 2.000 rpm using a homomixer to prepare a (Wlo)/W type suspension. The (Wlo)/W suspension formed in step 7 was heated to 80°C and continued stirring to remove isopropyl acetate contained in the shell wall and to remove the water-containing nitrified cotton particles from the water. It was precipitated inside.

The nitrified cotton particles remaining in the aqueous solution were transferred to another tank and washed with warm water at 50°C, and then dried under reduced pressure at 100″C to remove the encapsulated water to obtain nitrified cotton fiber hollow particles. The hollow particles obtained were substantially composed of nitrified cotton, had an average particle diameter of 20 μm, and an apparent specific gravity of 0.03 g/cc.

Examples 2 to 5 Nitrified cotton yarn hollow particles were produced in the same manner as in Example 1, except that the stirring speed was changed as shown in Table 1.

The obtained nitrified cotton yarn hollow particles were all substantially composed of nitrified cotton, and their average particle diameters and apparent specific gravity are shown in Table 1.

Comparative Example 1.2 Nitrified cotton yarn hollow particles were produced in the same manner as in Example 1, except that the stirring speed was changed as shown in Table 2.

Table 2 shows the average particle diameter and apparent specific gravity of each of the obtained nitrified cotton thread hollow particles.

Comparative Example 3.4 The nitrification type 1 hollow particles produced in Example 3 were separated by the distance of wind scattering to prepare the samples shown in Table 2.

Example 6 A slurry explosive having the composition shown in Table 3 was prepared as follows.

The method for producing the hydrous explosive composition used to evaluate the effectiveness of the nitrified cotton thread hollow particles of the present invention is based on ammonium nitrate 42
After heating a mixed solution of 40 parts of monomethylamine nitrate aqueous solution (including 15 parts of water) to 30°C, 0.5 part of the nitrified cotton thread hollow particles of Example 1 were added as hollow particles, and hydroxypropyl Add 1.0 part of modified guar gum and 13 parts of sodium nitrate, mix for about 2 minutes, and add phosphoric acid ester (manufactured by Dai-ichi Kogyo Co., Ltd., trade name NIBLYSURF A219B).
Add 0.2 parts of cross-linked starch, 2 parts of paint-grade aluminum powder, and a cross-linking agent (1% potassium piaroantimonate to guar gum) and mix uniformly for about 2 minutes to form a hydrous explosive composition. I got it.

Examples 7 to 11 The compositions shown in Table 3 were prepared in the same manner as in Example 6 using the nitrified cotton yarn hollow particles of Examples 2 to 5.

Comparative Examples 5 to 11 The compositions shown in Table 4 were prepared in the same manner as in Example 6 using the nitrified cotton yarn hollow particles of Comparative Examples 1 to 4 or without using the nitrified cotton yarn hollow particles.

Example 12 A W10 type emulsion explosive having the composition shown in Table 5 was prepared as follows.

First, by adding 65.5 parts of ammonium nitrate and 11 parts of sodium nitrate to 13 parts of water and heating, approximately 90.
An aqueous oxidizing agent solution at °C was obtained. On the other hand, 2.5 parts of sorbitan monooleate was added to 3.5 parts of microcrystalline wax (manufactured by Mobil Oil Company, trade name: Wax Rex 602).
A combustible mixture having a temperature of about 90°C was obtained by heating and melting the mixture.

Next, the mixture of combustible materials was first put into a heat-insulating container, and then the oxidizing agent solution was gradually poured and stirred to obtain a W10 type emulsion at about 90°C.

Furthermore, the nitrified cotton hollow particles produced in Example 1 0.
5 parts were added and mixed uniformly to obtain an emulsion explosive.

Examples 13 to 17 The compositions shown in Table 5 were prepared in the same manner as in Example 12 using the nitrified cotton yarn hollow particles of Examples 2 to 5.

Comparative Examples 12 to 17 Compositions shown in Table 6 were prepared using the nitrified cotton yarn hollow particles of Comparative Examples 1 to 4 or without using the nitrified cotton yarn hollow particles 811j in the same manner as in Example 12.

Example 18 2.6 parts of nitrified cotton [manufactured by Asahi Kasei Industries ■, trade name: HIG60, nitrification subdivision -70%], 0.5 parts of polyurethane resin [manufactured by Dainippon Ink & Chemicals, trade name: T5250], as a stabilizer Low molecular weight epoxy compounds [Union carbides, trade name: BAKEL, ITE ERL4221]
0.3 part was dissolved in 45.7 parts of isopropyl acetate, and the following procedure was carried out in the same manner as in Example 1 to obtain nitrified cotton thread hollow particles. The obtained hollow particles contained 70% nitrified cotton and had an average particle size of 25.
μm, and the apparent specific gravity was 0.02 g/cc. A slurry explosive was prepared using the hollow particles in the same manner as in Example 6, and tested in the same manner.

Example 9 The same procedure as in Example 18 was carried out except that the amount of nitrified cotton was changed to 1.5 parts and the amount of polyurethane resin was changed to 1.26 parts. The obtained hollow particles contained 40% nitrified cotton, had an average particle diameter of 20 μm, and had an apparent specific gravity of 0.02. Using these hollow particles, a slurry explosive was prepared in the same manner as in Example 6, and tested in the same manner.

Comparative Example 18 The same procedure as in Example 18 was carried out except that the amount of nitrified cotton was changed to 0.9 parts and the amount of polyurethane resin was changed to 1.65 parts. The obtained hollow particles contained 25% nitrified cotton, had an average particle diameter of 20 μm, and had an apparent specific gravity of 0.02. A slurry explosive was prepared using the hollow particles in the same manner as in Example 6, and tested in the same manner.

Regarding Examples 6 to 19 and Comparative Examples 5 to 1B, each slurry explosive and W10 type emulsion explosive were loaded into a polyethylene tube with a diameter of 25 mm and packaged to a weight of 100 g, and the following performance tests were conducted using a medicine package. Served.

Manufacture - (a) Specific gravity of explosive (g/cc) after week (b)
Measurement of bare detonation velocity (m/s) at 20°C, and (c)
In order to evaluate the explosive power, a ballistic pendulum test described in JTSK4810 (Explosives Performance Test Method) was conducted. The results are shown in Tables 3 to 6.

(Hereinafter, blank spaces) 21-22- Table 1 Table 3 [Effects of the Invention] The present invention provides hollow particles of hydrous explosives having an average particle diameter of 5 to 5.
200 μm and apparent specific gravity of 0.001 to 0.4 g
/cc, it is possible to obtain a high-performance hydrous explosive with no reduction in explosive power. The hydrous explosive of the present invention is extremely useful in industries such as civil engineering and mining because of its high performance.

Claims (1)

[Claims] 1. Contains 30% or more of nitrified cotton by weight and has an average particle size of 5 to 5.
200μm and apparent specific gravity 0.001 to 0.4g/
Nitrified cotton hollow particles characterized by being cc. 2. Contains 30% or more of nitrified cotton by weight and has an average particle size of 5~
200μm and apparent specific gravity 0.001 to 0.4g/
1. A water-containing explosive composition comprising nitrified cotton-based hollow particles of cc, an oxidizing agent, a sensitizing agent, a thickener, a surfactant, and water.