EP1478608B1 - Plastic explosive composition, especially for a small-calibre priming for tunnel construction, a method for the production thereof, and a booster for using the same - Google Patents

Abstract

In using a plastic explosive composition (PEC), the ignitor, in spite of initially closed stoppers (12), can be inserted very easily and precisely in the PEC. When the PEC is combined with a booster, safe and central placing of the ignitor in the sleeve (11) is ensured, and the PEC, because of the stoppers on both sides, can be safely and densely packed. The PEC contains (wt.%): pentaerythritol tetranitrate and/or hexogen and/or octogen as high explosive material (50-80), dibutyl phthalate and/or diamyl phthalate as plastifying agent (15-30), nitrocellulose (0.5-3), inorganic nitrates, e.g. sodium (Na) and/or potassium (K) nitrate (up to 10), and small amounts of impurities, colorants and inert materials. Independent claims are also included for the following: (1) a process for preparation of the PEC having the above properties involving making a mixture containing (wt.%) dibutyl phthalate and/or diamyl phthalate as plasticizer (15-30) and nitrocellulose (0.5-3) to form a gelatin, to which are added pentaerythritol tetranitrate (nitropenta) and/or hexogen and/or octogen as high explosive materials (50-80), inorganic nitrates (up to 10) and small amounts of colorant and inert materials, until a homogeneous composition is obtained; (2) a booster for the explosive material, especially for the borehole loading tube, a small caliber priming, and a boosting charge for tunnel construction, with a tubular sleeve (11) with plastics stoppers (12) at both end sections, of which at least one can be penetrated by the ignitor for the explosive in the sleeve (11), where the sleeve stoppers (12) are strongly and tightly closed, and at least one stopper has a central opening (19) for an ignitor, so that the ignitor is enclosed centrally, and can be arrested.

Description

The invention relates to a plastic explosive composition, in particular for a small-caliber starter for tunneling, with substances that are non-toxic, have good handling safety and detonability, with at least one highly explosive explosive and a plasticizer; and a method for its production with the features of the preamble of the single method claim; and a booster for an aforementioned plastic explosive composition, in particular for loading hoses for boreholes and a small-caliber initial ignition, ie boosting charge for tunneling, with a tubular sleeve with plugs made of plastic at both end portions, of which at least one permeable to an igniter of the explosive in the sleeve is.

The global trend towards larger explosive systems in the extraction of raw materials has led to the mechanization of the loading work. Explosive-free explosives, such as ANFO (Ammonium Nitrate Fuel Oil) explosives and emulsion explosives, are produced on mixed-load vehicles and are pumped directly into the wells by means of discharge devices. Such explosives have good blasting parameters, but are not in most cases Explosive capsule sensitive and require a strong initiation. Frequently, a so-called impact cartridge is used for this, which can be initiated with a conventional explosive ignition safely. In recent years, the use of boosters or ignition amplifiers has been amplified instead of impact cartridges. These usually consist of highly explosive explosives such as pentaerythritol tetranitrate (Nitropenta) and / or trinitrotoluene (TNT). For surface applications, the diameter of such booster is usually 65 mm.

Now loose explosives, in powder form or as emulsions to a greater extent in the underground area, especially in tunneling, used. However, the borehole diameters in tunneling are much smaller than those of surface mining operations in order to be able to carry out targeted explosions. Usually they are in the range of 36 to 50 mm. The loose explosives are blown or pumped into the wells using a loading hose. The loading tube is understandably smaller in diameter than the bore so that there is no jamming / clogging when the loading tube is inserted into the wellbore. Usually the outside diameter of the loading tube is between 25 and 27 mm, the inside diameter 19 mm. When loading technology in tunneling, the booster is provided with the explosive detonator, inserted into the charging hose and brought in this way with the charging hose into the hole. The diameter of the booster must therefore be smaller than the inside diameter of the charging hose.

The booster must cause a small-caliber initial ignition, so represent a small-caliber boost charge.

Known booster consist of a tubular sleeve, the ends of which are closed with plugs, one of the plugs having openings, such as a slot for easier insertion of the explosive and a detonator. From these openings explosive constituents can escape and liquid enter, whereby explosives can reach the inner walls of the packages, so the inner walls of bags or boxes for boosters, which can lead to problems from a safety and work-hygenic point of view. The slot also serves to insert the igniter into the explosive mass in the booster, which protrudes only loosely, at least without any further attachment and positioning in the explosive mixture. In the case of a solid explosive mixture is usually even a preformed cavity for the detonator to incorporate into the explosive mixture, but with the risk that the igniter sits too loosely in the cavity or vice versa to jamming during insertion of the igniter into the cavity of the Booster is coming. When introducing the igniter, moreover, the explosive mixture swells out of the booster, which also leads to undesirable contamination. The booster prepared in this way can also be fitted with an igniter from one side only, and consequently leads to a complicated, because only upright handling, which contains the risk of loss of the igniter and / or the explosive mixture. An exact, because extremely effective, centric alignment of each manufacturer in the diameter slightly varying igniter is only by careful Handling and alignment during the insertion of the detonator individually possible. That is, the person entitled to blast can adjust this only by hand.

Several compositions for such boosters are known in the literature. Already in 1929 Stettbacher ( Urbanski, T., chemistry and technology of explosives, VEB German publishing house for basic industry, Leipzig, 1964, volume III, page 239 ) Explosives consisting only of Nitropenta and Nitroglycerin, which he called Pentrinite. Depending on the quality of the nitropenta (crystal size) and the composition, a plastic mixture can be obtained, otherwise nitroglycerin will run out of the mixture after a few days. Exiting nitroglycerin from an explosive mixture always represents a serious quality and safety deficiency, since nitroglycerin has a impact energy of 0.2 J. After the z. B. valid German and European transport regulations, an explosive substance may only be transported if its impact energy greater than 2 J and its friction energy is greater than 80 N.
Stettbacher also proposed a substitute for dynamite, which consists only of nitroglycerin, nitrocellulose and nitropenta. Investigations have shown that this explosive is characterized on the one hand by a very high detonation velocity (> 8000 m / s), on the other hand the impact energy required for the explosion release is only 7.5 J (with the addition of potassium nitrate even 5 J), the required frictional energy only 180 N.

Also, gelatinous ammonium nitrate explosives with high nitroglycerin and / or nitroglycol content can be used for boosters. Since the critical diameter for gelatinous ammonium nitrate explosives is between 15 and 16 mm (excluding inclusion) depending on the composition, gelatinous ammonium nitrate explosives for such applications are additionally provided with highly explosive explosives in order to obtain the required detonator sensitivity. These explosive compositions are also very sensitive to impact. The impact sensitivity required for detonation release is 7.5 J. Another disadvantage of these explosive mixtures is the effect of "aging". Prolonged storage causes the fine air bubbles introduced by the manufacturing process to disappear. The internal surface of the explosive composition decreases and thus also its sensitivity (cf. Ullmann's Encyclopedia of Industrial Chemistry, Verlag Chemie GmbH, Weinheim, Volume 21 ).

Also cast or pressed explosive compositions of TNT or Nitropenta or mixtures of both substances are used for boosters.

Newer plastic explosives like for example FR-A-947052 known contain hexogen / octogen / Nitropenta mixtures and a plasticizer (eg, styrene-butadiene copolymer).

Many of the listed explosive compositions contain nitroglycerin and / or nitroglycol as a component. These substances are classified as "very toxic" according to the current hazardous substances legislation. The component TNT is also classified as "toxic". The use of these substances especially in the underground area is problematic considered. The known explosive compositions are therefore less suitable to achieve the object of the present invention satisfactorily.

As already mentioned, the known boosters are not dense and expensive to handle and are strongly influenced by the physical properties of the explosive mixtures, with the result that cavities for the detonators undergo changes which are difficult to calculate when the explosive mixtures are changed. Consequently, the known boosters are also unsuitable for satisfactorily achieving the object of the present invention.

Object of the present invention is to provide a plastic explosive composition, especially for a small-caliber initial ignition, ie boosting charge in tunneling, which contains no toxic substances, has a small critical diameter and still improved handling safety (higher impact and friction energy) than before to disclose known explosive compositions and a process for its preparation.

• 50 - 80 Gew.-% Pentaerythrittetranitrat und/oder Hexogen und/oder Octogen als hochbrisantem Explosivstoff,
• 15 - 30 Gew.-% Dibutylphtalat und/oder Diamylphtalat als Plastifiziermittel,
• 0,5 - 3 Gew.-% Nitrocellulose,
• bis zu 10 Gew.-% anorganischen Nitraten, wie Natrium- und/oder Kaliumnitrat, und
• geringen Beimengungen an Farb- und Inertstoffen

besteht; und hinsichtlich des Verfahrens zu dessen Herstellung durch die kennzeichnenden Merkmale des einzigen Verfahrensanspruches.A further object of the present invention is to provide a booster for a plastic explosive composition, in particular for charging hoses for boreholes and a small-caliber initial ignition, ie boosting in tunneling, which has none of the disadvantages mentioned in the prior art, in connection with the plastic explosive composition according to the application Transport and application safe, as well as easy to use, and ensures optimal and secure positioning of the igniter in the booster. The object with regard to the plastic explosive composition is inventively achieved in that the composition of

• 50-80% by weight of pentaerythritol tetranitrate and / or hexogen and / or octogen as a highly explosive explosive,
• 15-30% by weight of dibutyl phthalate and / or diamyl phthalate as plasticizer,
• 0.5-3% by weight of nitrocellulose,
• up to 10% by weight of inorganic nitrates, such as sodium and / or potassium nitrate, and
• small admixtures of colorants and inert substances

consists; and in terms of the process for its preparation by the characterizing features of the single method claim.

The task in terms of the booster is achieved by the characterizing features of the booster independent claim.

Advantageous embodiments of the invention will become apparent from the dependent claims.

According to the invention, the composition consists of 50 to 80 parts by weight of a highly explosive explosive such as pentaerythritol tetranitrate and / or hexogen and / or octogen, 15 to 30 parts by weight of a plasticizer such as dibutyl phthalate and / or diamyl phthalate, nitrocellulose in the order of 0.5 to 3%, inorganic nitrates such as sodium and / or potassium nitrate up to 10% and small amounts of colorants and inert substances.

The explosive composition is primarily intended as a small-caliber initial charge (diameter 15 mm), also known as boosters or boosters, for the safe ignition of loose explosives. Also powdery or emulsions.

Dibutyl phthalate and diamyl phthalate are used in the explosive industry, especially in the production of smokeless powder as a plasticizer (see Ullmann's Encyclopedia of Industrial Chemistry, Verlag Chemie GmbH, Weinheim, Volume 20, p 102). These substances therefore surprisingly contribute significantly to the composition according to the invention. The use of dibutyl phthalate is still out US-A-3311513 known.

The detonability of an explosive basically depends on its ignitability and the ability to relay the detonation.

The ignitability is defined according to DIN 20163 "Blasting technique, November 1994 edition", a comparison parameter for the ignition sensitivity of an explosive which detects the required detonator strength or the explosive quantity of an ignition amplifier. The "critical diameter" is according to DIN 20163 "blasting technique", the diameter of a charging station below which the detonation is no longer reliably forwarded. An explosive of high detonability therefore generally requires a small detonator strength and has a small critical diameter. For testing is generally z. For example, a detonator or an electric detonator contains 0.6 g Nitropenta as a secondary charge. According to Applicable (including German) regulations, the testing of explosives on detonator sensitivity is performed with a Prüfzünder, which has a lower secondary charge. Such test detonators contain 0.375 g or only 0.250 g Nitropenta. Internationally also Prüfzünder be used with 0.450 g Nitropenta.

According to the invention, dibutyl phthalate and diamyl phthalate are used as an excellent substitute for nitroglycerin / nitroglycol in order to overcome the disadvantages mentioned above - toxicological (very toxic) and safety-related properties. Although both substances are classified as "harmful" by the current hazardous substances legislation, they are not classified as "very toxic" or "toxic". The non-toxic, in any case not classified as "very toxic" or "toxic" dibutyl phthalate used in the application according to the invention is also referred to as Diisobutylphtalat and is classified according to hazardous substances legislation as only "dangerous for the environment".

zu einer Gelatine gemischt werden. Beispiel 4 ist als Vergleichsbeispiel zu betrachten, da hier kein Alkalimetallnitrat eingesetzt wird. Dibutylphtalat und Diamylphtalat besitzen, wie bereits ausgeführt, eine phlegmatisierende Wirkung für die Sprengstoffzusammensetzung. Die Handhabungssicherheit wird bei den vorstehenden anmeldungsgemäßen Rezepturen und der erfindungsgemäßen Rezeptur deutlich verbessert. Schlag- und Reibenergie sind höher als bei bekannten Sprengstoffzusammensetzungen. Andererseits weist die Sprengstoffzusammensetzung einen kleinen kritischen Durchmesser auf, der für sogenannte Booster gewünscht wird.According to the application is advantageously proposed that to achieve a desired high detonation velocity of at least 6260 m / s, a impact energy of at least 15 J and a friction energy of at least 360 N and a critical diameter of at least 15 mm and charging hoses less than the inner diameter, each according to the application Recipes of the table below

be mixed to a gelatin. Example 4 is to be regarded as a comparative example, since no alkali metal nitrate is used here. As already stated, dibutyl phthalate and diamyl phthalate have a phlegmatizing effect on the explosive composition. The handling safety is significantly improved in the above formulations according to the application and the recipe according to the invention. Impact and friction energy are higher than known explosive compositions. On the other hand, the explosive composition has a small critical diameter which is desired for so-called boosters.

Advantageously, it is further provided that the constituents of dibutyl phthalate and / or diamyl phthalate form a gelatin with nitrocellulose by mixing, which together with nitropenta and / or hexogen and / or octogen and sodium nitrate and / or potassium nitrate and the colorants and inert substances is a plastic homogeneous mass. The explosive mixture is thus particularly easy to handle and can be well filled in even extremely thin plastic sleeves, which are well movable in the thin charging tube of perhaps only up to 19 mm inside diameter. The explosive mixture is mainly filled in rigid, cylindrical plastic sleeves, which are closed on both sides with plastic plugs. The plastic plugs have a star-shaped predetermined breaking point, whereby the insertion of the igniter can be done very easily and easily.

Advantageously, it is further provided that the explosive mixture has a consistency with a plasticity, which causes a simple insertion in both sides closable plastic sleeves, as well as the introduction of a detonator facilitates in this booster and ensures the maintenance of the igniter therein. The explosive composition thus has a plastic consistency, which facilitates the insertion of the igniter. Also, the retention of the igniter in the plastic sleeve (the booster) is significantly better for a plastic explosive composition than for cast or pressed explosive compositions (TNT / Nitropenta).

• 15 - 30 Gew.-% Dibutylphtalat und/oder Diamylphtalat als Plastifiziermittel, und
• 0,5 - 3 Gew.-% Nitrocellulose,

gemischt wird, bis sich eine Gelatine bildet und anschließend in diese Gelatine

• 50 - 80 Gew.-% Pentaerythrittetranitrat (Nitropenta) und/oder Hexogen und/oder Octogen als hochbrisantem Explosivstoff, und
• bis zu 10 Gew.-% anorganische Nitrate, wie Natrium- und/oder Kalciumnitrat, und
• geringe Mengen an Farb- und Inertstoffen

The inventive method, according to which a composition of

• 15-30% by weight of dibutyl phthalate and / or diamyl phthalate as plasticizer, and
• 0.5-3% by weight of nitrocellulose,

is mixed until a gelatin forms and then into this gelatin

• 50-80% by weight of pentaerythritol tetranitrate (nitropenta) and / or hexogen and / or octogen as a highly explosive explosive, and
• up to 10% by weight of inorganic nitrates, such as sodium and / or calcium nitrate, and
• small amounts of colorants and inert substances

be added until by mixing a plastic homogeneous mass forms, in particular supports the mechanization of the loading work on site, ensures a high safety standard and leads to a long-term stability
Explosive composition, in addition to the advantages that have already been described in connection with the composition.

The task with regard to the booster for a plastic explosive composition according to the application is achieved according to the invention in that the plugs firmly and tightly close the sleeve and at least one plug has a central, individually openable passage opening for an igniter which centers, locks and seals the igniter.

Surprisingly, it has been shown that the igniter can be introduced particularly easily and precisely into a plastic explosive mass despite initially closed plug. A combination of the plastic explosive mass with the booster according to the invention ensures almost automatically the safe and centric Seat of the igniter in the sleeve with largely tightness even with inserted detonator. D. h., The plastic explosive mass is securely and tightly packed in the sleeve due to the mutual stopper, so that neither explosives or explosive components can get to the outside and humidity inside. As already stated, have known plug openings, z. B. slots for easier insertion of the igniter from which explosives and / or liquid leak / can occur and the environment is polluted. This also leads to safety problems.

Advantageously, it is provided that the explosive mixture fills the inner volume of the sealed sleeve only incompletely. As a result, a swelling of plastic explosive mass when inserting the second plug and the igniter is safely excluded in a simple manner.

Advantageously, it is further provided that the remaining volume in the closed sleeve corresponds at least to the volume of the initiator to be introduced and a plug. As a result, various effects can be prevented. It has been found that thereby pushing out of the opposite plug when inserting the second plug can be prevented as well as when inserting the igniter in one of the plug. Experience has shown that even a few percent of the filling volume suffice as a free-standing cavity.

According to the application is further provided that the sleeve is rigid and circular cylindrical and the plug tight and firmly projecting with a portion into the interior of the sleeve and having an outer remaining flange whose outer diameter corresponds to that of the sleeve. As a result, a safe and predictable handling of the plug is possible even in robust operation on site. Because of the flange, each plug can only be pressed to a predetermined depth in the sleeve. The plugs are either easy to squeeze o. The like. And / or with adhesive o. The like. Provide and thus virtually automatically seal the sleeve. Since the flange has the same outer diameter as the sleeve, the mobility of the booster in the charging hose is not limited.

According to the application is further provided that each plug is elastic and circularly symmetrical and the outer flange, together with a central projecting into the sleeve portion has a shape similar to a thimble, with a protruding into the sleeve bottom, which forms the passage opening for the igniter. With this simple measure, the handling is greatly facilitated especially when inserting a detonator. The thimble forms, so to speak, a goal funnel for the detonator, which leads the detonator safely to the passage opening.

Advantageously, it is further provided that the bottom of the plug is oriented orthogonally to the longitudinal extent of the sleeve and has a smaller wall thickness with a predetermined breaking point applied radially from the center. As a result, the passage opening, which is closed on its own, can always be broken open in the center, without the need for special dexterity or force. According to the application, it is further provided that one or both surfaces of the bottom are radially provided with straight lines of reduced cross-section, which form the predetermined breaking point (s) and, similar to a cake, at least three identical straps (pieces). As a result, the production cost is to keep low, since the predetermined breaking point itself are to be made of radially extending lines of smaller cross-section and already satisfy three pieces of cake-shaped tabs to form a star-shaped through hole and to achieve all application advantages can.

According to the application is further provided that the tabs of the star-shaped passage opening center the detonated detonator due to their predetermined elasticity, set and seal the sleeve at the same time. As a result, the inserted igniter is always inserted centrally in the sleeve and at the same time secured by the forming tabs against pulling out. The star-shaped passage opening is broken only as far as necessary, that is according to the diameter of the igniter. The forming tabs nestle snugly and thus close to the detonator. The sleeve is sealed according to the application with and without detonator. Also, an accidentally inserted detonator can be removed again, because the elasticity of the tabs allow this and they relax after removal and close the passage opening again.

Furthermore, it is advantageously provided that the sleeve and the plug made of polyethylene or polypropylene. This allows the materials to be used, which are easy to work with, ensure a safe interaction with each other and optimally meet the sliding requirements in the charging hose, with an outer diameter corresponding to the critical diameter and, if necessary, smaller than the inner charging hose diameter.

Advantageously, it is further provided that the sleeve meets the requirements of an extrusion process and the plug which an injection-molding process. This makes it possible to manufacture the booster according to the application economically attractive.

example 1

At an estimated 100 parts by weight, 28.3% dibutyl phthalate and 1.7% nitrocellulose are mixed until gelatin forms. Now 65% nitropenta, 5% potassium nitrate and small amounts of colorants and inert substances are added until a homogeneous plastic mass is formed. Blasting parameters: Initiierfähigkeit: Test detonator PETN 0.450 g (Diameter: 15 mm) Detonation velocity: 6400 m / s (Diameter: 15 mm) Impact energy: 20 y frictional energy: 360 N

Example 2

At an estimated 100 parts by weight, 25% dibutyl phthalate and 1% nitrocellulose are mixed until a gelatin is formed. Now, 65% Nitropenta, 9% potassium nitrate and small amounts of colorants and inert substances added until a homogeneous plastic mass forms. Blasting parameters: Initiierfähigkeit: Test igniter PETN 0.250 g (Diameter: 15 mm) Detonation velocity: 6260 m / s (Diameter: 15 mm) Impact energy: 20 y frictional energy: 360 N

Example 3

At an estimated 100 parts by weight, 20% dibutyl phthalate and 1% nitrocellulose are mixed until a gelatin forms. Now 75% nitropenta, 4% potassium nitrate and small amounts of colorants and inert substances are added until a homogeneous plastic mass is formed. Blasting parameters: Initiierfähigkeit: Test igniter PETN 0.250 g (Diameter: 15 mm) Detonation velocity: 6430 m / s (Diameter: 15 mm) Impact energy: 15 y frictional energy: > 360 N

Comparative Example 4

At an estimated 100 parts by weight, 20% dibutyl phthalate and 1% nitrocellulose are mixed until gelatin forms. Now 79% nitropenta, 0% potassium nitrate and small amounts of colorants and inert substances are added until a homogeneous plastic mass is formed. Blasting parameters: Initiierfähigkeit: Test igniter PETN 0.250 g (Diameter: 15 mm) Detonation velocity: 6900 m / s (Diameter: 15 mm) Impact energy: 17.5 y frictional energy: > 360 N

Example 5

21% dibutyl phthalate and 1.5% nitrocellulose are mixed at an estimated 100 parts by weight until a gelatin forms. Now 68.5% nitropenta, 9% potassium nitrate and small amounts of colorants and inert substances are added until a homogeneous plastic mass is formed. Blasting parameters: Initiierfähigkeit: Test igniter PETN 0.250 g (Diameter: 15 mm) Detonation velocity: 6475 m / s (Diameter: 15 mm) Impact energy: 15 y frictional energy: 360 N

Example 6

21% dibutyl phthalate and 1.0% nitrocellulose are mixed at an estimated 100 parts by weight until a gelatin forms. Now 70.0% nitropenta, 8% potassium nitrate and small amounts of colorants and inert substances are added until a homogeneous plastic mass is formed. Blasting parameters: Initiierfähigkeit: Test igniter PETN 0.250 g (Diameter: 15 mm) Detonation velocity: 6750 m / s (Diameter: 15 mm) Impact energy: 17.5 y frictional energy: > 360 N

The formulations are characterized by explosive properties, which correspond to those formed with toxic substances, by an extremely high impact energy and the other advantages already mentioned.

Fig. 1

eine Ansicht eines erfindungsgemäßen Booster, teilweise geschnitten,

Fig. 2

eine Draufsicht des Boosters gem. Fig. 1 entsprechend der Linie A-A,

Fig. 3

einen schematisch dargestellten Stopfen des Boosters in Seitenansicht, und

Fig. 4

eine Draufsicht des Boosters gem. Fig. 1 entsprechend der Linie B-B mit aufgebrochener Durchgangsöffnung.

An embodiment of the present invention, in particular with regard to the booster for a plastic explosive composition, in particular for charging hoses for boreholes and a small caliber initial ignition for tunneling is explained in more detail below with reference to a drawing. It shows:

Fig. 1

a view of a booster according to the invention, partially cut,

Fig. 2

a top view of the booster gem. Fig. 1 according to the line AA,

Fig. 3

a plug shown schematically the booster in side view, and

Fig. 4

a top view of the booster gem. Fig. 1 corresponding to the line BB with broken through opening.

Fig. 1 partially shows a view of a booster 10 according to the application, which has a sleeve 11 made of plastic and two plugs 12, also made of plastic. The plugs 12 have an outer flange 13 with an outer diameter corresponding to that of the sleeve 11. The sleeve 11 and the plug 12 have a circular cylindrical basic shape and are firmly and tightly connected. This connection takes place via a circular cylindrical portion 14 which is integrally connected to the flange 13 of the plug 12 and z. B. protrudes a few millimeters into the sleeve 11 and is firmly and tightly engaged with the inner wall 15 of the sleeve 11. This connection can be made non-positively and / or by the aid of adhesive or heat. Although these are the preferred compounds, it goes without saying that screwed or other connections, such as snap and snap connections, are also possible. Regarding the in Fig. 1 Bottom shown cut 12, the flange 13 has a centrally disposed, projecting into the sleeve 11 thimble-shaped (cylindrical) section 16 with a bottom 17 and one in the Fig. 1 indicated radial breaking point 18. The flange 13 is open in the area of the thimble-shaped portion 16, so that only a cross-sectional area in Fig. 4 shown detonator 21 with its front side against the bottom 17 and thus can be pressed against the predetermined breaking point 18 and breaks them in a predeterminable manner. The detonator can also fill the entire star-shaped through opening 19, that is to say the base 17. The predetermined breaking point (s) 18 are formed by from the center radially (radially) extending lines with cross-sectional reduction, which in one of the surfaces, for. B. the outer surface of the bottom 17 is introduced. The flange 13 also prevents the plug 12 from being pushed in during the opening 19 being broken through.

Fig. 2 shows a plan view corresponding to line AA in Fig. 1 , Visible are the circular symmetrical shape of the plug 12 and the flange 13 as well as the bottom 17 with radial, radial predetermined breaking points 18 are provided, two of which are shown. These form a total of six cake piece-shaped sections, better called tabs 20. The thus formed, star-shaped through hole 19 is arranged deep in the thimble-shaped portion 16 and thus facilitates quasi funnel-shaped threading of the igniter 21. Moreover, the description goes to Fig. 1 directed.

Fig. 3 schematically shows a side view of a plug 12 with flange 13, cylindrical portion 14 for fixing the plug 12 in the sleeve 11 and the thimble-shaped portion 16 shown in phantom to insert this plug 12 with still closed through hole 19 in the sleeve 11, without the, the other end of the sleeve 11 occlusive, further plug 12 is pushed out again, according to the application provided that the sleeve 11 is only partially filled with plastic explosive. According to the invention, the sleeve 11 is also filled with plastic explosive only to such an extent that even expulsion of explosive during the insertion of the igniter 21 fails to occur. Experiments have shown that in normal igniter the remaining volume about 1 cm at a z. B. 15 mm diameter booster 10 corresponds, or about a filling of only 90 to 95% of the booster 10th

Fig. 4 shows a plan view of Fig. 3 along the line BB. The representation corresponds to the acc. Fig. 2 to the description of which reference is also made. However, the passage opening 19 is broken and therefore shown in a star shape, with an inner cross section which may correspond to that of a fuze 21. The igniter 21 can be larger and smaller Have cross-section. The radially arranged lines of the predetermined breaking points 18 have formed elastic tabs 20, which determine the available free diameter of the passage opening 19 with their angular tips and, due to their elastic material tension, hold the igniter 21 in the center and secure it against being pulled out. With a suitable choice of the material break the predetermined breaking points barely on, as absolutely necessary and the tabs 20 nestle against the igniter 21, so that even in the case of the inserted igniter 21, the through hole 19 is virtually closed tight.

In summary it can be stated that the radial predetermined breaking point 18 of the plug 12 is designed so that it is dense on the one hand and thus prevents the escape of explosives or components thereof, on the other hand is thin and has a special construction, the easy insertion of the igniter 21st allows. When inserting the igniter 21, the predetermined breaking points 18, forming tabs 20, broken. The igniter 21 can easily be introduced into the plastic explosive mass according to the invention and is thus securely and centrically fixed in the sleeve 11 by the combination of the elastic explosive mass with the plastic bottles 20. By the tabs 20 slipping out of the igniter 21 is further difficult. Since the plug 12 is identical on both sides, the igniter 21 can be inserted from each side into the sleeve 11. The booster 10 does not have to be taken by the person entitled to blast in a certain direction in order to introduce the igniter 21 can.

The advantage of a plastic explosive mass in such a booster 12 over a cast, solid explosive mixture is further that for the introduction of the igniter 21 no preformed cavity must be present in the explosive. A preformed cavity always presents a risk that the igniter 21 may be too loose or jamming occurs upon insertion of the igniter 21. The volume of the sleeve 11 is only 90 to 95% filled with the plastic explosive mass (on one side of the sleeve 11 remain empty about 10 millimeters, with a diameter of the sleeve 11 in the centimeter range). This cavity is u. a. sufficient for the insertion of the igniter 21, without that arranged on the opposite side of the sleeve 11 plug 12 is moved out of the sleeve 11. The sleeve 11 and the plug 12 are made of plastics such as polyethylene and polypropylene. The sleeve 11 preferably in the extrusion process and the plug 12 in the injection-molding process, which leads to a good economic price-performance ratio.

The in the above description, in the Fig. 1, 2, 3 and 4 As well as the claims disclosed features of the invention may be essential both individually and in any combination for the realization of the invention in its various embodiments.

Claims (19)

1. Plastic explosive composition, in particular for a small-calibre priming for tunnel construction and/or underground blasting, with substances which are not toxic, are safe to handle and have a good detonation capacity, with at least one high-explosive substance and one plasticizer, characterized in that the composition consists of

   - 50-80 wt.-% pentaerythritol tetranitrate and/or hexogen and/or octogen as high-explosive substance,

   - 15-30 wt.-% dibutyl phthalate and/or diamyl phthalate as plasticizer,

   - 0.5-3 wt.-% nitrocellulose,

   - up to 10 wt.-% inorganic nitrates, such as sodium and/or potassium nitrate, and

   - small additions of colourants and inert materials,

   the constituents dibutyl phthalate and/or diamyl phthalate form, by mixing, a gelatin with nitrocellulose which, together with PETN and/or hexogen and/or octogen and sodium nitrate and/or potassium nitrate and the colourants and inert materials, is a plastic homogeneous composition.
2. Explosive composition according to claim 1, characterized by a critical diameter of at least 15 mm, a detonation rate of at least 6260 m/s, an impact energy of at least 15 J and a friction energy of at least 360 N.
3. Explosive composition according to claim 2, characterized by

   - 65 wt.-% PETN and/or hexogen and/or octogen,

   - 28.3 wt.-% dibutyl phthalate and/or diamyl phthalate,

   - 1.7 wt.-% nitrocellulose,

   - 5 wt.-% sodium and/or potassium nitrate, and

   - small additions of colourants and inert materials.
4. Explosive composition according to claim 2, characterized by

   - 65 wt.-% PETN and/or hexogen and/or octogen,

   - 25 wt.-% dibutyl phthalate and/or diamyl phthalate,

   - 1.0 wt.-% nitrocellulose,

   - 9 wt.-% sodium and/or potassium nitrate, and

   - small additions of colourants and inert materials.
5. Explosive composition according to claim 2, characterized by

   - 75 wt.-% PETN and/or hexogen and/or octogen,

   - 20 wt.-% dibutyl phthalate and/or diamyl phthalate,

   - 1.0 wt.-% nitrocellulose,

   - 4 wt.-% sodium and/or potassium nitrate, and

   - small additions of colourants and inert materials.
6. Explosive composition according to claim 2, characterized by

   - 68.5 wt.-% PETN and/or hexogen and/or octogen,

   - 21 wt.-% dibutyl phthalate and/or diamyl phthalate,

   - 1.5 wt.-% nitrocellulose,

   - 9 wt.-% sodium and/or potassium nitrate, and

   - small additions of colourants and inert materials.
7. Explosive composition according to claim 2, characterized by

   - 70 wt.-% PETN and/or hexogen and/or octogen,

   - 21 wt.-% dibutyl phthalate and/or diamyl phthalate,

   - 1.0 wt.-% nitrocellulose,

   - 8 wt.-% sodium and/or potassium nitrate, and

   - small additions of colourants and inert materials.
8. Explosive composition according to one or more of the preceding claims, characterized by a consistency with a plasticity which effects a simple insertion into plastic sleeves which can be sealed at both ends, and also facilitates the insertion of an ignitor into this ignition enhancer and ensures that the ignitor stops therein.
9. Process for producing the plastic explosive composition according to claim 1, in particular for a small-calibre priming for tunnel construction, with substances which are not toxic, are safe to handle and easy to detonate, with at least one high-explosive substance and one plasticizer, characterized in that a composition of

   - 15-30 wt.-% dibutyl phthalate and/or diamyl phthalate as plasticizer, and

   - 0.5-3 wt.-% nitrocellulose,
   is mixed until it forms a gelatin and then

   - 50-80 wt.-% pentaerythritol tetranitrate (PETN) and/or hexogen and/or octogen as high-explosive substance, and

   - up to 10 wt.-% inorganic nitrates, such as sodium and/or potassium nitrate, and

   - small quantities of colourants and inert materials are added to this gelatin until a plastic homogeneous composition forms by mixing.
10. Booster which contains a plastic explosive composition according to claim 1, in particular for loading tubes for bore holes and a small-calibre priming, thus supercharge for tunnel construction, with a tubular sleeve (11) with plastic stoppers (12) at both end sections, of which at least one can be penetrated by an ignitor (21) of the explosive in the sleeve (11), characterized in that the stoppers (12) seal the sleeve (11) securely and tightly and at least one stopper (12) has a central through-hole (19) that opens individually for an ignitor (21), which centres and locks the ignitor (21) in place and surrounds it in a sealing manner.
11. Booster according to claim 10, characterized in that the explosive mixture only incompletely fills the internal volume of the sealed sleeve (11), with a diameter corresponding to the critical diameter.
12. Booster according to claim 11, characterized in that the volume of the sealed sleeve (11) that remains free corresponds to at least the volume of the ignitor to be inserted (21) and one stopper (12).
13. Booster according to claim 12, characterized in that the sleeve (11) is rigid and circular cylindrical and the stoppers (12) project in a secure and tight manner with a section (14) into the inside of the sleeve (11) and have a flange (13) which remains outside, the external diameter of which corresponds to that of the sleeve (11).
14. Booster according to claim 13, characterized in that each stopper (12) is elastic and circularly symmetric and the external flange (13), together with a central section (16) that projects into the sleeve (11), has a shape similar to a thimble, with a base (17) which projects into the sleeve (11) and forms the through-hole (19) for the ignitor (21).
15. Booster according to claim 14, characterized in that the base (17) of the stopper (12) is aligned orthogonal to the longitudinal extension of the sleeve (11) and has a smaller wall thickness with a predetermined breaking point (18) radiating out from the middle.
16. Booster according to claim 15, characterized in that one or both surfaces of the base (17) are provided radiating out with straight lines of reduced cross-section which form the predetermined breaking point(s) (18) and at least three identical plates (20) (pieces), in the manner of a cake.
17. Booster according to claim 16, characterized in that the plates (20) of the star-shaped through-hole (19) centre and fix the inserted ignitor (21) thanks to their predeterminable elasticity and simultaneously seal off the sleeve (11).
18. Booster according to one or more of the preceding claims 10 to 17, characterized in that the sleeve (11) and the stoppers (12) consist of polyethylene or polypropylene.
19. Booster according to one or more of the preceding claims 10 to 17, characterized in that the sleeve (11) meets the requirements of an extrusion process and the stopper (12) meets those of an injection-moulding process.

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