Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B21/00—Apparatus or methods for working-up explosives, e.g. forming, cutting, drying
  • C06B21/0033—Shaping the mixture
  • C06B21/0066—Shaping the mixture by granulation, e.g. flaking
• • 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
  • C06B25/18—Compositions containing a nitrated organic compound the compound being nitrocellulose present as 10% or more by weight of the total composition
  • C06B25/24—Compositions containing a nitrated organic compound the compound being nitrocellulose present as 10% or more by weight of the total composition with nitroglycerine
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
  • C06B45/04—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive
  • C06B45/06—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component
  • C06B45/10—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component the organic component containing a resin
  • C06B45/105—The resin being a polymer bearing energetic groups or containing a soluble organic explosive

Definitions

• the present invention relates to the field of homogeneous propellant powders in grains for weapons and more particularly to that of gun powders for battle tanks.
• the invention relates to propellants based on nitrocellulose, nitrated oil and polyvinyl nitrate, as well as a process for their production.
• the basic material for the manufacture of current propellant powders is nitrocellulose, which gelatinized by a suitable solvent such as an ethyl ether-ethyl alcohol mixture and mixed with the usual additives known to those skilled in the art, such as stabilizers and moderators. combustion, provides the powders commonly known by the general name of "smoke-free powders". These powders are well suited for most conventional weapons. They are for example described in the book “Les Poudres et Explosifs", by MM. L. VENNIN, E. BURLOT, H. LE-CORCHE, Librairie Polytechnique ch. BERANGER, page 578 et seq., (1932).
• the present invention relates to a new homogeneous propellant powder in grains, based on nitrocellulose, an explosive nitrated oil and polyvinyl nitrate, which has sufficient strength to be used in tank guns while not having the disadvantages of double base powders and in particular by being less erosive than the latter.
• the powders according to the invention are characterized in that they contain between 50 and 75 parts by weight of nitrocellulose, between 5 and 25 parts by weight of polyvinyl nitrate and between 5 and 25 parts by weight of a nitrated oil per 100 parts by weight of energy base.
• the powders according to the invention have a force comparable to that developed, under the same firing conditions, by conventional gun powders based on nitrocellulose and nitroglycerine, but they have a lower combustion temperature than the latter and are therefore less erosive for weapons.
• the Applicant has moreover observed that the powders according to the invention have a lower tendency to exudate than conventional powders based on nitrocellulose and on a nitrated oil, and that, surprisingly, their temperature coefficient is significantly lower than that of conventional gun powders.
• the temperature coefficient measures the variations in the ballistic properties of a powder (pressure in the chamber and speed of the projectile at the exit of the weapon) as a function of temperature, the lower this coefficient is the less the ballistic properties of the powder are dependent on temperature.
• the powder grains according to the invention contain, as was said above, between 50 and 75 parts of nitrocellulose, between 5 and 25 parts of nitrated oil and between 5 and 25 parts of polyvinyl nitrate per 100 parts of base energetic.
• the Applicant has observed that apart from these ranges of composition, no homogeneous powder is obtained having sufficient ballistic and mechanical properties to be able to be used as gun powders.
• An oil chosen from the group consisting of nitroglycerin, trimethylol methane trinitrate and trimethylol ethane trinitrate can be used as the nitrated oil. According to a preferred embodiment of the invention, nitroglycerin is used.
• the invention also relates to a method for manufacturing powders according to the invention.
• This process is a process with solvents which consists in kneading in the presence of said solvents the energy bases until a homogeneous paste is obtained which is spun in the press, in the form of strands which are wrung out and cut into grains. The powder grains are then soaked and dried. Obtaining a homogeneous paste from nitrocellulose, a nitrated oil: and polyvinyl nitrate is very delicate.
• a solvent acetone / light aliphatic alcohol is used as solvent in proportions such that the content of the acetone paste on mixing is between 30 and 36% by weight relative to the weight of dry nitrocellulose and polyvinyl nitrate. and in that the acetone / alcohol weight ratio is between 1.10 and 1.50.
• As light aliphatic alcohol ethyl alcohol is preferred.
• the kneading must be carried out as follows. The selected quantities of nitrocellulose, generally impregnated with alcohol, and nitrated oil, generally already dissolved in acetone, are introduced into the mixer, and the mixture is supplemented with acetone and alcohol.
• the stabilizer is then added together with any additives and the mixer is then rotated.
• dry polyvinyl nitrate is added in fractions by rotating the kneader between each fraction so as to obtain each time the absorption of polyvinyl nitrate by the paste already formed.
• the mixer is rotated for several hours so as to obtain a perfectly homogeneous paste. About five hours is usually enough.
• the dough thus obtained is then spun into strands by press. The strands are then wrung before being cut into grains.
• the spin is made at a temperature below 30 ° C so as not to alter the mechanical properties of the strands.
• the strands are cut into grains.
• the grains after having optionally undergone a first hot drying, are then soaked in water and dried in a conventional manner.
• the grains of powder are generally not smoothed, but they can be graphitized according to the intended use.
• the invention thus makes it possible to have grains of homogeneous powder based on nitrocellulose, nitrated oil and polyvinyl nitrate which are in particular usable in the tanks of battle tanks, these grains of powder having a force comparable to that developed in the same conditions by conventional powder grains based on nitrocellulose and nitroglycerin.
• the powder grains according to the invention also have the double advantage of having a lower combustion temperature than these conventional powder grains and of having a lower temperature coefficient.
• the powder according to the invention gives, according to the projectile temperatures, a speed at least equal to or greater than that given by a conventional simple base powder and that, between - 40 ° C and + 51 ° C the speed of the projectile varies only 49 m / s with the powder according to the invention whereas it varies from 88 m / s with a conventional powder.
• the pressures developed in the chamber during ignition are the same applies to the pressures developed in the chamber during ignition.
• the combustion temperature of the powder according to the invention calculated from the energy balance is 3600 K ° whereas for a conventional double base powder of the same strength it is close to 3780K °, so that one thanks to the invention has a sufficiently strong powder to be able to be advantageously used in tank guns, while being less hot than the usual double base powders used in this type of weapon.
• Example 1 Take the powder from Example 1 and graphite it in a bezel with 0.2% by weight of graphite.
• the powder thus obtained is fired at room temperature in a smooth 120 ° barrel.
• the projectile weighs 6.2 kg and 8.2 kg of powder are used.
• the speed of the projectile at 40 meters from the muzzle of the cannon is 1675.5 m / s and the maximum pressure developed in the combustion chamber of 4068 bars.
• This example is intended to show the importance of compliance with the operating conditions in the manufacture of the powder and more particularly the importance of compliance with the conditions relating to the quantities of solvents used.
• Example 2 The procedure is exactly as described in Example 1 with the only difference that a total of 18.1 kg of alcohol and 23.6 kg of acetone are used.
• the dough content of acetone in kneading is therefore only 28% relative to the weight of dry nitrocellulose and polyvinyl nitrate.
• the acetone / alcohol weight ratio is 1.3 and is therefore found to be correct.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Molecular Biology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Dispersion Chemistry (AREA)
• Emergency Medicine (AREA)
• Crystallography & Structural Chemistry (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Air Bags (AREA)
• Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
• Colloid Chemistry (AREA)
• Medicinal Preparation (AREA)

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Publications (3)

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• 1978
  • 1978-12-22 FR FR7836103A patent/FR2444651A1/fr active Granted
• 1979
  • 1979-11-27 IL IL58818A patent/IL58818A/xx unknown
  • 1979-12-05 US US06/100,646 patent/US4347087A/en not_active Expired - Lifetime
  • 1979-12-06 CA CA000341336A patent/CA1143165A/en not_active Expired
  • 1979-12-11 EP EP79401002A patent/EP0013850B1/de not_active Expired
  • 1979-12-11 DE DE7979401002T patent/DE2963381D1/de not_active Expired
  • 1979-12-18 NO NO794131A patent/NO148413C/no unknown
  • 1979-12-21 AU AU54151/79A patent/AU526506B2/en not_active Ceased

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