Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06C—DETONATING OR PRIMING DEVICES; FUSES; CHEMICAL LIGHTERS; PYROPHORIC COMPOSITIONS
  • C06C15/00—Pyrophoric compositions; Flints

Definitions

• This invention relates to non-toxic, zinc peroxide-containing, IR tracer compositions and to IR tracer projectiles containing such compositions which, when fired, generate a dim visibility IR trace.
• US Patent No. 5,661 ,257 patented Aug 26, 1997, MULTISPECTRAL COVERT TARGET MARKER.
• Such patented target marker included a near-IR emitting photodiode which was encased in a hardened polymeric molding material.
• Those patented target markers suffered from the defect that they were not easily amenable to be incorporated into an IR projectile.
• compositions included metallic magnesium as well as strontium nitrate, sodium nitrate and barium therein.
• IR tracer compositions suffer from the defects that barium is a toxic element and that sodium emits yellow light.
• Tracer projectiles provide a reliable means of determining whether projectiles impact on the desired target or whether adjustments in aim are necessary.
• One problem with the use of conventional tracer projectiles is that they emit visible light, which thereby makes the source of the tracer ammunition discernable to the enemy.
• An object of a second aspect of the present invention is to provide improved IR tracer projectiles which generate an IR trace which is substantially-completely IR radiation.
• heavy metals e.g., barium nor any other toxic elements
• a broad aspect of the present invention provides a non- toxic substantially- metallic-metal-free, zinc peroxide-containing, IR tracer composition
• a non-toxic substantially- metallic-metal-free, zinc peroxide-containing, IR tracer composition comprising: from about 26 to about 30% by weight, or from about 65 to about 80% by weight, of zinc peroxide peroxide; from about 40 to about 47% by weight of potassium nitrate; from about 10 to about 25% by weight of a non-metallic fuel which consists of sodium salicylate; from about 5 to about 26% by weight of a retardant which consists of either iron carbonate or magnesium carbonate or calcium carbonate; from about 5 to about 10% by weight of at least one binder which is either calcium resinate, or a synthetic resin binder which consists of a copolymer of hexafluoropropylene and vinylidene fluoride, or from about 5 to about 7.5% by weight of cellulose acetate butyrate; wherein the total percentage of the ingredients add up
• the present invention in another aspect, provides an IR tracer projectile comprising a hollow cylindrical shell made of a suitable metallic material, and having a conical nose; a conventional heavy filler disposed in the hollow conical nose; the non-toxic, metallic-metal-free, zinc peroxide-containing, infrared tracer composition as disclosed hereinabove in its generic, sub-generic and specific aspects, compressed immediately against the filler; a conventional ignition material compressed against said compressed tracer composition; and a metal disc capping the hollow shell.
• the present invention provides infrared-producing (hereinafter "IR"- producing) compositions which are capable of producing a consistent IR output when provided in IR tracer projectiles which are medium caliber, e.g., 0.50 caliber, long range accuracy ammunition (Match grade)
• IR infrared-producing
• the IR output includes near IR and far IR bands (0.76 to 3.0 ⁇ m). The intensity of the IR radiation depends on the specific wavelength of these bands.
• Conventional pyrotechnic mixtures typically contain a finely-divided mixture of an oxidizer and a fuel (metallic, non-metallic or organic fuel).
• the oxidizer which contains oxygen, is added to sustain combustion and the metallic atoms are responsible for the characteristic color output.
• the fuel is added in order to sustain combustion of the mixture and to provide heat energy.
• Finely divided powdered fuel is very reactive with an oxidizing agent. Above a certain temperature, namely, the ignition temperature, the oxidizer decomposes to release oxygen, which then reacts quickly with the fuel in an exothermic reaction.
• An oxidizer and a fuel alone do not make practical compositions for the purpose of providing suitable emissions.
• Each of a flame retardant and a binding agent is also incorporated into the mixture.
• the IR tracer compositions of aspects of the present invention possess unique requirements not generally addressed by the prior art conventional tracer systems. While it is not desired to be limited to any particular theory, it is believed that a hypothesis concerning the formation of purely infrared emission without the presence of visible light may be developed based on black body radiation theory. The requirement would then be for the IR tracer to maximize output at a wavelength of 1 to 3 ⁇ m range.
• compositions were investigated to maximize the IR intensity while also maximizing the duration of the IR trace and minimizing the generation of excessive amounts of heat for each type of medium caliber projectiles.
• the compositions to be described hereinafter burn cleanly and relatively coolly and emit relatively-small (i.e., almost negligible) quantities of visible light in proportion to the infrared radiation emitted.
• the basic components of the IR tracer compositions of aspects of the present invention are able to augment near-IR emissions when fired. This is accomplished by the addition of an IR producing oxidizer and fuel.
• the IR tracer compositions of aspects of the present invention include zinc peroxide as the oxidizer, an organic fuel, a flame retardant, and a binder.
• the oxidizer is zinc peroxide.
• Peroxides of other transition metals e.g., titanium, chromium, manganese, iron, cobalt, nickel, copper, zirconium, etc, are not useful in the IR tracer composition of aspects of the invention.
• the peroxides of such transition metals either provide inert compositions or provide compositions which emit toxic effluents.
• the preferred organic fuel is sodium salicylate (C 7 H 5 NaO 3 ). This organic fuel has a low melting point and generates a large amount of gases during the combustion, which facilitates the removal of solid residues and soot inside the tracer cavity of the projectile.
• lithium salicylate nor potassium salicylate would be suitable since they provide compositions which are too hygroscopic. Furthermore, these compounds are not conveniently commercially available and so the compositions cannot be easily industrialized.
• Another component of the IR tracer compositions of aspects of the present invention is potassium nitrate.
• the nitrates of other alkali metals are not useful in IR tracer compositions of aspects of the present invention, since lithium nitrate produces a composition which is too hygroscopic, while sodium nitrate emits a yellow color.
• the preferred flame retardants in the IR tracer compositions of aspects of the present invention are iron carbonate and magnesium carbonate although calcium carbonate would also be useful.
• the presence of iron carbonate or magnesium carbonate or calcium carbonate brings about a better control of the rate of burning and reduces substantially the flash and output of visible light.
• the carbonates of other transition metals are not suitable.
• the carbonates of chromium and cobalt contaminate the atmosphere, the carbonate of nickel has carcinogenic properties and the carbonate of zirconium has excessive luminosity properties.
• a binder maintains the other particulate forms of constituents of the IR tracer compositions of aspects of the present invention together.
• the binder increases the structural integrity of the IR tracer composition to prevent any break up of the trace in flight. It protects the composition from moisture and increases the flowability of the composition.
• Suitable binders include cellulose acetate butyrate (CAB), calcium resinate, a vinyl acetate resin or the fluoroelastomer known by the trade mark VITON A. Such binders have the properties of acting as a fuel retardant, as a waterproofing agent, and/or as an agent to reduce soot formation.
• CAB cellulose acetate butyrate
• VITON A fluoroelastomer
• Such binders have the properties of acting as a fuel retardant, as a waterproofing agent, and/or as an agent to reduce soot formation.
• the IR tracer compositions of aspects of the present invention differ significantly over conventional tracer compositions, especially conventional IR tracer compositions, of
• the IR tracer compositions were prepared by first dry mixing the powdered ingredients to provide a dry intermediate composition.
• the binder was dissolved in a suitable aprotic solvent, namely, methyl ethyl ketone.
• the so-formed binder solution was then incorporated into the dry intermediate composition to provide a wet mixture.
• the wet mixture so provided was transferred to a suitable mixer in order to obtain a substantially-completely homogeneous mixture of all ingredients.
• the homogenous mixture so-formed was dried in an oven at about 20-40°C until it was sufficiently dry for sieving.
• the dry mixture was then sieved to break up agglomerated particles.
• the IR tracer composition was thus provided as relatively small particles of random shape.
• the tracer projectile 10 includes a hollow shell 12 of, preferably, a copper alloy (90% Cu/ 10% Zn), whose hollow nose 14 is filled with a suitable heavy filler 16.
• the IR tracer composition 18 is compressed immediately against the filler 16.
• a conventional ignition material 20 is compressed against the IR tracer composition 18.
• the IR tracer projectile 10 is capped by means of a brass closure disc 22.
• each of the IR tracer compositions was inserted into 0.50 caliber tracer projectiles and fired.
• the IR tracer composition inside the projectile body was ignited by hot gases emitted by a propellant.
• the IR trace was found to be visible from the firing position and could not be seen with the naked eye by the observers placed at an angle with respect to the trajectory of the IR tracer projectile.
• the calorific output of the IR tracer composition measured with a calorimeter was about 500 cal/g, which is about one third less than the calorific output generated by conventional IR tracer compositions, (500 cal/g compared to 1200 cal/g for conventional IR tracer compositions).
• the IR trace can, thus, be designated as a cold trace.
• the IR intensity of the IR emission as measured with a spectrophotometer equipped with IR filters at a wavelength of 760 nanometers was found to be about 1 to 4 watts/steradian , and at a wavelength of 3,000 nanometers was found to be about 1.7 to 2.1 watts/steradian.
• the IR tracer compositions of aspects of the present invention was found to have an IR luminosity as measured with a spectrophotometer at a wavelength of 760 nanometers of about 1 to 2 watts/steradian and an IR luminosity as measured with a spectrophotometer at a wavelength of 3000 nanometers of about 1 to 4 watts/steradian.
• the IR trace can be seen up to 1000m compared to 600m for conventional 0.50 caliber tracer projectiles.
• the medium caliber , i.e., 0.50 caliber, IR tracer projectiles of an aspect of the present invention containing the IR tracer compositions of aspects of the present invention have been found to increase the length of trace along the firing line by up to about 120%.
• the IR tracer compositions of aspects of the present invention produce relatively low burn rate materials so that the IR trace can be seen from the firing point to a longer distance down range.
• the burn rate is adjustable for medium caliber, i.e., 0.50 caliber, ammunition to meet or exceed NATO and specific user requirements.
• medium caliber i.e. 0.50 caliber
• ammunition to meet or exceed NATO and specific user requirements.
• particular burn rates can be adjusted, the ratio of IR radiation to visible light can be optimized (i.e., substantially no visible light), and the general physical and chemical properties can be carefully selected.
• the medium caliber i.e., 0.50 caliber, IR tracer projectiles of aspects of the present invention containing the IR tracer compositions of aspects of the present invention have a relatively slow burning rate so that the IR tracer can be seen up to 1800m compared to 1500m for conventional 0.50 caliber tracer projectiles.
• the IR tracer compositions of aspects of the present invention do not degrade with time, when properly stored at a temperature varying between 5°C and 20°C, with a relative humidity which ranged between 50% and 70%.
• the calorific heat of an IR tracer projectile containing IR tracer compositions of aspects of the present invention at the beginning of the storage period was about 675 cal/g and remained constant over a minimum storage period of 6 months.
• IR tracer compositions of aspects of the present invention do not contain any toxic elements
• compositions of aspects of the present invention may easily be industrialized.
• Not all zinc peroxide-containing compositions satisfy the utility requirements as set forth in the above tests.
• compositions having the ingredients/proportions set forth in the following Tables 2A, 2B and 2C have been found not to be useful
• the present invention provides IR tracer compositions for the production of IR projectiles for medium caliber, i.e., 0.50 caliber, ammunition.
• the IR tracer compositions of aspects of the present invention are non- toxic.
• the rate of burning is selectively controllable so that the IR trace can be seen at longer distance from the firing position than conventional IR trace projectiles containing conventional IR trace compositions.

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• Engineering & Computer Science (AREA)
• Metallurgy (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)

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• 2005
  • 2005-04-05 US US11/098,368 patent/US20060219339A1/en not_active Abandoned
• 2006
  • 2006-03-28 EP EP06721718A patent/EP1866264A4/de not_active Withdrawn
  • 2006-03-28 WO PCT/CA2006/000455 patent/WO2006105635A1/en active Application Filing
  • 2006-03-28 CA CA2604977A patent/CA2604977C/en not_active Expired - Fee Related
  • 2006-03-28 EP EP11166798A patent/EP2360134A3/de not_active Withdrawn

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