Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B31/00—Compositions containing an inorganic nitrogen-oxygen salt
  • C06B31/28—Compositions containing an inorganic nitrogen-oxygen salt the salt being ammonium nitrate
  • C06B31/32—Compositions containing an inorganic nitrogen-oxygen salt the salt being ammonium nitrate with a nitrated organic compound
• • 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
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S149/00—Explosive and thermic compositions or charges
  • Y10S149/11—Particle size of a component
  • Y10S149/112—Inorganic nitrogen-oxygen salt
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S149/00—Explosive and thermic compositions or charges
  • Y10S149/11—Particle size of a component
  • Y10S149/115—Organic fuel

Definitions

• the present invention relates to improved pyrotechnic gas-generating compositions. More particularly, the present invention concerns inorganic nitrate gas-generating compositions which burn-off rich in gas, and are useful in pressure, gas-producing propellant charges, cartridges, missile propulsion, and other explosive applications.
• Ammonium nitrate compositions which contain various additives which act as catalysts and/or control the reaction velocity are well known for use in ejecting fireextinguishing compositions from fire extinguishers.
• cartridges are utilized containing a charge of an ammonium nitrate-containing mixture, which develops a substantial amount of gas when burning.
• the gas volume which is developed by such mixtures depends, to a large extent, upon the content of ammonium nitrate, which yields during the reaction predominantly gaseous nitrogen and water.
• Such a gas-producing composition may contain, for example, a high content of ammonium nitrate, i.e., about 78.5%, about 9% potassium nitrate, about 6.9% ammonium and about 5.6% potassium dichromate.
• This mixture is capable of yielding a gas volume of up to about 200 millimeters per gram of charge mixture. While this gas-producing mixture may find some application, for example, in fire extinguishers as discussed above, the yield of gas generated by this mixture and available for use is too low for many purposes and applications, such as a gas-producing propellant charge in cartridges, missile applications, etc., and thus its use is highly restricted.
• An object of the present invention is to provide an improved gas-generating composition which overcomes the disadvantages of the prior art.
• Another object of the present invention is to provide an improved inorganic nitrate'containing, gas-generating composition capable of generating a substantial increase in gas yield.
• a further object of the present invention is to produce an improved, gas-generating composition without materially increasing the reaction temperature, reducing the reaction velocity, and impairing the ignitability of the mixture.
• a still further object of the present invention is to produce an improved, gas-generating composition which is Patented Oct. 24, 1967 ice not characterized as an explosion-dangerous substance, and wherein the catalyzing action of ammonium dichromate upon ammonium nitrate is not adversely affected.
• a gas-generating composition containing a mixture of ammonium nitrate and aminotetrazole it has been found, for example, that an ammonium nitrate charge containing aminotetrazole increases the useable and effective gas volume by as much as about 100% and even higher.
• the ammonium nitrate present in the gas-generating composition of the present invention is present in a major amount of about 53 to 83% by weight, based on the weight of the total components of the composition, preferably about 60 to by weight.
• the aminotetrazole is present in a minor amount, i.e., about 2 to 25% by weight, advantageously about 5 to 15% by weight.
• a part of the aminotetrazole present in the gas-generating composition of the present invention can be exchanged with other suitable nitrogen-containing compounds.
• suitable nitrogen-containing compounds for example, about 5 to 40% of the aminotetrazole can be substituted with a mixture of about 60 to 98% aminotetrazole and about 2 to 40% dicyandiamide.
• this nitrogen-containing material improves the burning-off velocity and lighting power of the composition while not materially changing the volume of the gas being generated.
• the ammonium nitrate used in the composition of the present invention may be of any type, for example, ordinary commercial ammonium nitrate, such as is used for fertilizers, or military grade ammonium nitrate.
• the commercial grade nitrate generally contains a small amount of impurities, and the particles of nitrate are usually coated with a moisture-resisting material, such as parafiin wax.
• Military grade ammonium nitrate which is almost chemi cally pure is particularly suitable for use in the composi tion of the present invention.
• the ammonium nitrate is preferably used in a finely divided particulate form, which may be obtained either by pulling or by grinding.
• ammonium nitrate, gas-generating composition of the present invention frequently contains minor amounts of other inorganic nitrates, such as, for example, sodium nitrate or potassium nitrate.
• inorganic nitrates can be present in an amount of about 6 to 9% by weight preferably about 6.5 to 8.5% by weight.
• the present invention also contemplates the presence of a coolant, for example, ammonium oxalate, urea oxalate, ammonium nitrate, oxalic acid, oxamide, and the like, and an inorganic catalyst, for example, ammonium dichromate and the alkali and alkaline earth metal dichromates, e.g., sodium, potassium and magnesium dichromate.
• a coolant for example, ammonium oxalate, urea oxalate, ammonium nitrate, oxalic acid, oxamide, and the like
• an inorganic catalyst for example, ammonium dichromate and the alkali and alkaline earth metal dichromates, e.g., sodium, potassium and magnesium dichromate.
• the gas-generating composition contains coolants, they are present in an amount of about 5 to 7% by weight, preferably 5.5 to 6.5% by weight.
• the dichromates are present, they are employed in
• the gas-generating composition of the present invention may optionally, and frequently, advantageously, contain other constituents.
• ballistic modifiers can be used in the composition of the present invention to control the burning rate and to enhance the ignitability of the composition.
• Suitable ballistic modifiers include guanidine nitrate, nitroguanidine, cyclotrimethylenetrinitramine, 2,4-dinitrophenoxyethanol, and the like.
• Various burning rate promoters such as, for example, finely divided carbon, which are not catalysts per se may also be incorporated into the present composition.
• Oximes or asphalts may be used to improve low temperature ignitability.
• Aromatic amines are advantageously used as gas-evolution, stabilization additives.
• aromatic amines examples include toluenediamine, diphenylarnine, naphthalenediamine, and toluenetriamine.
• the aromatic hydrocarbon amines can be used in amounts of between about 0.5 and 5%. While these aromatic hydrocarbon amines are effective, they are frequently not sufficiently effective for severe duty when used alone. It has been found that superior stabilization is obtained when N-phenylmorpholine is used with an aromatic hydrocarbon amine. Because of the plasticizing effect of the N- phenylmorpholine, it is generally desirable to use the aromatic hydrocarbon amines as the primary stabilizing additive and the N-phenylmorpholine in an amount needed to obtain the specific stability. In general, when aromatic hydrocarbon amines are present, between about 0.1 and 1% of N-phenylmorpholine will be used.
• all of the components of the gasgenerating composition of the present invention will have a grain size of less than 200 microns to faciliate intimate mixture or blending of the various components with each other and correspondingly achieve a homogeneous mixture, which assures uniform burning.
• the ammonium nitrate compositions of the present invention are advantageously compressed into a compact form.
• the ingredients are intimately mixed and then consolidated under pressure by molding or extrusion at ambient or elevated temperatures.
• compression pressures of up to about 2,500 kg/cm. can be used to make the desired pellets.
• Producing compact pellets by this method produces a defined burning surface and achieves a desired burning velocity, and thus a uniform reaction mixture.
• Various types of conventional molding or extrusion apparatus are suitable for the purposes of the present invention. In some instances, it has been found desirable to add solvents to the gas-generating composition to facilitate the molding process. Solvents suitable for this purpose include hexane, heptane, cyclohexane, benzene, petroleum ether, and the like.
• the pyrotechnic mixture of the present invention is useful as pressure, gas-producing, propellant charges in cartridges; as gas-generating compositions for use in jet propulsion, e.g., in the propulsion of rockets, ground-t0- ground missiles, ship-to-shore missiles, air-to-ground missiles; as a propulsion means in assist take-off of military and commercial aircraft, and many other uses.
• Example 1 A pyrotechnic mixture is prepared by mixing 78.5% by weight of ammonium nitrate with 9% by weight potassium nitrate, 6.9% by weight ammonium oxalate, and 5.6% by weight of potassium dichromate. The components of the mixture, which have an average particle size of less than 200 microns, are thoroughly mixed to form a homogeneous mixture. The mixture is then formed into pellets using a conventional molding apparatus at a compression pressure of about 2,500 kg./cm. Upon burning, the composition yields a gas volume of approximately 200 cc. per gram of charge mixture.
• Example 11 A pyrotechnic composition is prepared by mixing 66.7% by weight ammonium nitrate with 7.6% by weight potassium nitrate, 5.9% by weight ammonium oxalate, 4.8% by weight ammonium dichromate and 15.0% by weight of aminotetrazole. The mixture is pelleted in the same manner as in Example I. Upon burning, a gas volume of about 400 cc. is produced per gram of charged mixture.
• a pyrotechnic gas-generating composition comprising about 53 to 83% of ammonium nitrate and about 2 to 25% of aminotetrazole.
• composition of claim 1 wherein about 5 to 40% by weight of the aminotetrazole is replaced by a mixture of about 2 to 40% by weight dicyandiamide and 60 to 98% by weight of aminotetrazole.
• composition of claim 1 wherein all the components have a grain size of less than about 200 microns.
• a pyrotechnic gas-generating composition comprising about 53 to 83% by weight of ammonium nitrate, about 6 to 9% by weight potassium nitrate, about 5 to 7% by weight ammonium oxalate, about 4 to 6% by weight ammonium dichrom-ate, and about 2 to 25% by weight of aminotetrazole.
• composition of claim 4 wherein about 5 to 40% by Weight of the aminotetrazole is replaced by a mixture of about 2 to 40% by weight dicyandiamide and 60 to 98% by weight of aminotetrazole.
• a process for producing a pyrotechnic mixture of improved gas-producing properties which comprises mixing together about 53 to 83% by weight ammonium nitrate, and about 2 to 25 by weight of aminotetrazole to form a homogeneous mixture, and forming said mixture into pellets by compressing them at a pressure of up to about 2,500 kg./cm.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Air Bags (AREA)
• Nitrogen Condensed Heterocyclic Rings (AREA)

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Cited By (15)

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Citations (1)

• 1965
  • 1965-08-14 DE DE19651446918 patent/DE1446918A1/de active Pending
• 1966
  • 1966-08-04 US US570163A patent/US3348985A/en not_active Expired - Lifetime
  • 1966-08-12 NL NL6611390A patent/NL6611390A/xx unknown
  • 1966-08-12 BE BE685468D patent/BE685468A/xx unknown
  • 1966-08-12 GB GB36323/66A patent/GB1126567A/en not_active Expired
  • 1966-08-12 AT AT772166A patent/AT261460B/de active

Patent Citations (1)

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