Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B41/00—Compositions containing a nitrated metallo-organic compound
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B25/00—Compositions containing a nitrated organic compound
  • C06B25/34—Compositions containing a nitrated organic compound the compound being a nitrated acyclic, alicyclic or heterocyclic amine
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B43/00—Compositions characterised by explosive or thermic constituents not provided for in groups C06B25/00 - C06B41/00
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06C—DETONATING OR PRIMING DEVICES; FUSES; CHEMICAL LIGHTERS; PYROPHORIC COMPOSITIONS
  • C06C7/00—Non-electric detonators; Blasting caps; Primers

Definitions

• the technical sector of the present invention is that of initiation compositions sensitive to percussion intended for example to equip the heads of percussion rockets.
• the percussion rocket heads intended to ensure the initiation of deflagrant or detonating delay or instantaneous relays comprise an initiation or primer composition, sensitive to the penetration of a striker tip with a more or less sharp end. Under the effect of this percussion, this composition decomposes by detonating or exploding very strongly depending on the nature of the explosive used.
• the initiation compositions exist in similar forms and belong to two distinct families; a first family which does not have a priming power and therefore serves either to initiate a delay or a composition with a special effect, or to initiate the detonation on condition of adding a priming element following it generally consisting of lead azide; the second family has sufficient ignition power to directly initiate the detonation of a relay without requiring an intermediate composition.
• the first family belongs to the compositions based on basic lead styphnate called "NOL 130" in the USA, lead dinitrorésorcinate called “L mixture” or RD 1651 in GREAT BRITAIN or lead thiocyanate in FRANCE.
• the second family belongs to compositions based on primary explosives such as lead azide with the addition of tetrazene, especially used in France.
• compositions which are moreover very sensitive, have the drawback of not supporting storage at medium temperature, above 75 ° C., for periods of time greater than a few days and of not supporting temperature peaks either. , of the order of 100 to 120 ° C, for durations greater than a few hours, conditions which are frequently encountered in places of storage or use of ammunition equipped with these primers.
• French patent 2,309,493 mainly describes a process for coating primary explosives and generally mentions the possibility of preparing primers from copper chlorotetrazolate, oxidants and reducing agents. However, it is above all to facilitate handling primary explosives by coating them with a binder; moreover, no priming composition is proposed.
• Detonation initiation compositions are characterized by their sensitivity to percussion, by their heat stability and by their power to initiate a secondary explosive.
• Conventional compositions based on tetrazene have good sensitivity and good priming power but have the disadvantage of an alteration of these properties under the action of temperature.
• the conventional compositions based on lead thiocyanate have a good sensitivity which is not altered by temperature but it does not have any initiating power; they require the introduction into the pyrotechnic chain of an element generally consisting of lead azide.
• the object of the present invention is to provide an initiation composition very sensitive to percussion, at least as sensitive as the conventional compositions mentioned above, but whose properties are preserved under severe environmental conditions.
• the subject of the invention is therefore an initiation composition endowed with high thermal stability sensitive to percussion and comprising a primary explosive and a sensitization additive, characterized in that it comprises 40 to 95% by mass of a explosive with tetrazolic cycle, 2.5 to 40% by mass of an oxidizing agent and 2.5 to 40% by mass of a reducing agent.
• the primary explosive can be represented by 5-nitrotetrazole, the mercury or silver salt of 5-nitrotetrazole, neutral or basic azotetrazole of silver or lead, halogenated tetrazoles and their salts, or a mixture of these.
• the oxidant can be represented by potassium, strontium or barium chlorate or perchlorate, lead or manganese dioxide, potassium permanganate, sodium or potassium dichromate or a mixture of these, and the reducing agent with antimony sulfide, lead thiocyanate, titanium, zirconium, boron or a mixture thereof.
• composition according to the invention resides in the fact that it has excellent thermostability properties while retaining its sensitivity to initiation even after a long stay in a harsh environment.
• the primer according to the invention predominantly generates a shock wave capable of initiating the charge of a projectile, such as an explosive shell provided with its percussion rocket, a shell with a hollow charge etc. .
• a determined charge of the mixture obtained is introduced by manual or mechanical, unitary or multiple process, into cells of miniature stainless steel detonators with an internal diameter of approximately 3.8 mm, then a sealing disc is placed. paper or plastic fiber and each load is compressed with a force of around 300 daN.
• the detonators thus prepared can be initiated by percussion through the shutter disc using a steel tip with a frustoconical end.
• Another series of conventional initiators is produced in the same way, containing an initiation composition containing 95% by mass of lead azide and 5% of tetrazene.
• the apparatus includes a base allowing the estimation of the priming power by detonation, behind a variable aluminum barrier, of a charge of 50 mg of pentrite whose regime is verified by piercing or not drilling a 2 mm thick steel witness plate.
• the initiators according to the invention produce in a very short time a deflagration similar to those which are necessary at the head of certain pyrotechnic chains such as those with short delay for example. They have a very good sensitivity which is little modified after each of the tests unlike the conventional primers which provide widely dispersed results.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Air Bags (AREA)

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Citations (4)

• 1984
  • 1984-12-06 DE DE8484402506T patent/DE3478595D1/de not_active Expired
  • 1984-12-06 EP EP19840402506 patent/EP0183884B1/de not_active Expired

Patent Citations (4)

Non-Patent Citations (1)

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