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
  • C06B33/00—Compositions containing particulate metal, alloy, boron, silicon, selenium or tellurium with at least one oxygen supplying material which is either a metal oxide or a salt, organic or inorganic, capable of yielding a metal oxide
  • C06B33/08—Compositions containing particulate metal, alloy, boron, silicon, selenium or tellurium with at least one oxygen supplying material which is either a metal oxide or a salt, organic or inorganic, capable of yielding a metal oxide with a nitrated organic compound
• • 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
• • 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
  • C06B45/18—Compositions or products which are defined by structure or arrangement of component of product comprising a coated component
  • C06B45/30—Compositions or products which are defined by structure or arrangement of component of product comprising a coated component the component base containing an inorganic explosive or an inorganic thermic component
  • C06B45/32—Compositions or products which are defined by structure or arrangement of component of product comprising a coated component the component base containing an inorganic explosive or an inorganic thermic component the coating containing an organic compound

Definitions

• the following invention relates to pressable aluminum-containing explosive compositions. More particularly, the invention relates to low-sensitivity, pressable aluminum-containing explosive compositions and a method for producing them.
• Pressable explosive compositions that contain aluminum and high explosives such as for example l,3,5,7-tetranitro-l,3,5,7-tetraaza cyclooctane (HMX), and l,3,5-trinitro-l,3,5- triaza cyclohexane (RDX) have been known for some time. These have generally been explosive compositions using wax as the binder. Such wax-based compositions do not however satisfy the requirements for explosives for low-sensitivity ammunition.
• high explosives such as for example l,3,5,7-tetranitro-l,3,5,7-tetraaza cyclooctane (HMX), and l,3,5-trinitro-l,3,5- triaza cyclohexane (RDX)
• pressable explosive compositions can be made in an aqueous environment by what one skilled in the art knows as a water slurry process. Because of safety considerations, aluminum-containing compositions are not ordinarily made in water since aluminum reacts exothermally with water under formation of aluminum hydroxide and hydrogen gas. It has therefore been more common to mechanically mix in aluminum with this type of composition. This can result however in a mixture of explosive and aluminum that is not homogenous in the charges after these are pressed.
• PBXIH-18 pressable aluminum-containing composition
• This composition is comprised of HMX, aluminum, Di-2-ethyl hexyl adipat (also called Di-octyl adipat or simply DOA) and HyTemp 4454 (Polyacrylic binder sold by Zeon Chemicals).
• the composition of this material in terms of percentage weight of HMX, aluminum and binder was not specified and is still unknown.
• Comp-A3 is a well-known RDX composition with wax as the binder.
• Comp-A3/aluminum compositions are produced by mechanically mixing aluminum together with Comp- A3 and has been used in large quantities in weapons systems.
• a disadvantage with such mechanical mixing is that the aluminum and explosive are not mixed well enough and after pressing the result is charges where the aluminum and the explosive are not homogenously dispersed.
• Another disadvantage with this Comp- A3/aluminum composition is that it does not satisfy the requirements for use in low- sensitivity ammunition. PBXIH-18 was therefore developed to satisfy the requirements for the explosive.
• PBXEH- 18 uses a slurry of explosive and aluminum in a perflouronated solvent PF-5080 (essentially completely flouronated octane compositions, sold by 3M).
• PF-5080 essentially completely flouronated octane compositions, sold by 3M.
• the process resembles what one skilled in the art refers to. as a water slurry process. However, water is replaced by PF-5080 because of fear for reaction of aluminum with water.
• Joseph Turci et al. (US 5 472 531) describes an aluminum-containing composition that is made by kneading together an explosive, aluminum and a binder together with a volatile solvent in a kneading " machine, and thereafter extruding out the product which is then cut up in order to make a powder of the composition.
• This process has several disadvantages, among others requiring the use of an expensive kneading machine and extruding equipment.
• a more safety related disadvantage is that this process also uses a pre-dried explosive. Transportation and handling of dried HMX or RDX are, as described previously, connected with a risk. In addition to the increased risk, there is also an economic disadvantage in that predrying the explosive requires time, energy and equipment.
• compositions are based on CL-20 ( 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12- hexaazaisowurtzitane ) as the explosive and CAB ( cellulosic acetate butyrate) as the polymer with BDNPA/F (1: 1 mixture of Bis(2,2-dinitropropyl)acetal and Bis(2,2- dinitropropyl)formal ) as a softener.
• CL-20 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12- hexaazaisowurtzitane
• CAB cellulosic acetate butyrate
• BDNPA/F 1 mixture of Bis(2,2-dinitropropyl)acetal and Bis(2,2- dinitropropyl)formal
• compositions contain CL-20 as the explosive, which one skilled in the art knows as a substantially more sensitive explosive than HMX or RDX. One skilled in the art would therefore be unlikely to use this type of composition in a low-sensitivity ammunition.
• CL-20 is also very expensive as a result of the costly process of its manufacture.
• Dyno Nobel ASA has for many years manufactured compositions based on RDX, wax and aluminum. This has been performed using passivated aluminum for the process and is based on an older French patent (FR 2 031 677).
• the French patent describes a process whereby by using passivated aluminum one can make compositions with wax and other binders so long as the binder contains an acidic group such as for example a carboxylic acid group or an acidic hydroxyl group such as for example phenol.
• the acidic group was necessary in order to coat the aluminum with wax and thereby be able to make a homogenous granulate of RDX, aluminum and binder. Without these acidic groups, it was only possible to coat the explosive with aluminum dust.
• the passivating of aluminum in this patent is based on warming up a suspension of aluminum in an aqueous solution of calcium bichromate or in an aqueous solution of mono-natrium phosphate and boric acid.
• the first-mentioned, so-called bichromated aluminum was for years used as passivated aluminum.
• bichromated aluminum was for years used as passivated aluminum.
• Dyno Nobel has, for several years before the restrictions on bichromated aluminum, worked with alternate passivating methods.
• the present invention relates to a pressable explosive composition that comprises between 5% by weight and 55% by weight aluminum and between 45% by weight and 95% by weight HMX and/or RDX, the remainder being a binder.
• the binder that is used is of such a type that the explosive composition will satisfy the requirements for use in a low-sensitivity ammunition (IM-requirements).
• the binder can be, but is not limited to, a mixture of a polyacrylic elastomer such as HyTemp 4454 (marketed by Zeon Chemicals) and a softener.
• the softener can be, but is not limited to 2-diethylhexyladipat (also known as plastomoll, dioctyl adipat or DOA).
• compositions according to the invention will, as a result of the aluminum content, provide an explosive with increased explosive pressure ("enhanced blast explosive").
• an elastomeric binder such as for example a HyTemp 4454/DOA mixture as used in the present invention, provides explosive compositions with appropriate characteristics such that they can be used in low-sensitivity ammunition.
• HMX- or RDX-based compositions with a binder-mixture of HyTemp 4454 and DOA have been in focus the last 10-20-years and have been shown to have quite good IM characteristics. Compositions with this binder system have therefore often been used in various weapons systems.
• the present invention allows the use of a press operation to produce charges that have increased explosive pressure and that can be used in low- sensitivity ammunition.
• One skilled in the art is aware of several advantages afforded by the use of a press operation as opposed to a casting process, whether cast-cured or melt- pourable. One of these is that a much higher production tempo is possible whereas a casting/stiffening process is time-consuming.
• pressing equipment is much cheaper than casting equipment.
• One skilled in the art will therefore appreciate the economic advantages of pressing charges as opposed to casting them so long as the charges do not have too large of a diameter, which is a limiting factor for pressable charges.
• the present invention relates to a method for producing the aforementioned compositions by what is known by one skilled in the art as a standard water slurry process.
• a standard water slurry process explosive crystals and passivated aluminum powder is washed in water and heated before a solution of a binder system is added. After such addition, the mixture is further heated to 100° C. such that the solvent is distilled whereby the binder is precipitated out and coats the particles of explosive and aluminum, and binds these together into granulated particles.
• the distilled solvent is directly recycled after separation from water. The granulates of the coated product are isolated by filtering.
• the present invention provides clear advantages in that the compositions can be produced in a water slurry process.
• a water slurry process provides the advantage over a mechanical dry mixing of a composition with explosive and aluminum powder of providing a much more homogenous granulate where aluminum and the explosive are evenly dispersed in each corn. This is important for one skilled in the . art since an even, homogenous dispersion of explosive, aluminum and binder is essential in the finished charges since they would otherwise not have consistent performance in terms of safety and yield.
• the present invention has the advantage that the raw material crystals can be moist before their use in the process.
• the explosive crystals can be produced, stored and transported in a moist state.
• a kneading process such as described by Joseph Turci et al. (US 5 472 531) it is known by one skilled in the art that dry crystals must be used. Handling large quantities of dry RDX and HMX crystals is known to one skilled in the art to be associated with higher risk than handling such crystals in a moist state.
• one is relieved from the need to dry the crystals which one skilled in the art knows to be an economic advantage since it does not require the use of drying equipment, energy and drying time.
• the present invention allows the production of aluminum- containing compositions in a standard water slurry process by removing the solvent by distillation by heating up to 100° C, such that the binder that is precipitated binds together the explosive and the aluminum.
• the binder that is precipitated binds together the explosive and the aluminum.
• the present invention allows the production of aluminum- containing compositions in a standard water slurry process using aluminum that is passivated with isostearic acid as opposed to the much more environment-unfriendly and health-damaging and more expensive aluminum that is passivated by bichromation such as described in the French patent (FR 2 031 677).
• passivated means that the aluminum is coated with a material/composition that actively hinders the reaction of aluminum with water under the conditions that exist in a water slurry process for the production of an explosive. This effect can be achieved by a coating that physically prevents water from coming in contact with the aluminum, a coating that has an inhibiting effect, on the reaction between water and aluminum, or a combination of these.
• the coating is created by materials/compositions that have relatively little damaging effect on the environment beyond the explosive's intended explosive effect, that is to say, it should not leave poisonous residues that can enter the environment.
• the invention should therefore not be understood to be limited to the preferred coating of isostearic acid, in that one skilled in the art will understand that other types of wax or binders will have the same, or approximately the same effect as the preferred isostearic acid.
• HMX crystalline explosives
• CL20 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane
• HNS 2,2',4,4',6,6'- hexanitrotransstilben
• TATB l,3,5-triamino-2,4,6-trinitrobenzene
• NTO 3-nitro- l,2,4-triazole-5-one
• elastomers such as for example styrene-butadine or styrene-isoprene copolymer which are available from among other sources Kraton polymers.
• Other examples are europren and cyanacryl (trademarks from EniChem), Krynac (trademark from Bayer polymers), Nipol (trademark from Zeon chemicals) and Noxtite (trademark from Nippon Mektron ).
• energy-rich elastomers have been investigated for use in explosive compositions however none of these are commercially available today.
• HyTemp 4454 has been chosen because it has been used for years in the explosives industry for pressable compositions and for the known characteristic that HyTemp 4454 results in compositions with excellent characteristics for use in low-sensitivity ammunition.
• HyTemp is also known to have good compatibility with explosives, something that is very important for this type of composition.
• DOS Dioctyl sebacat
• IDP Isodecsyl pelargonate
• Dioctyl maleate DOM
• Dioctyl phthalate DOP
• Glycidylic acid polymer GAP
• BDNPA/F BDNPA/F (1:1 mixture of Bis(2,2-dinitropropyl)acetal and Bis(2,2- dinitropropyl)formal)
• Alkyl-NENA N-alkyl-Nitrato Ethyl Nitramine
• HyTemp 4454 and DOA are used as the binder because this binder mixture is known to one skilled in the art to provide pressable explosive compositions with good characteristics for use with low-sensitivity ammunition.
• HyTemp 4054 and HyCar 4054 were used, which are the same polymer as HyTemp 4454, but which are delivered in larger clumps compared to HyTemp 4454.
• passivated aluminum is defined as passivated with 0. 3% by weight isostearic acid.
• Example 1 In a 150 1 reactor, 13.05 kg of HMX was washed in approximately 50 1 water under stirring. The mixture was heated up to approximately 60° C. and 0.75 kilograms of passivated aluminum was added to this mixture. Thereafter an ethyl acetate solution of 0.3 kg HyTemp 4454 and 0.9 kg DOA was added in a thin stream. Thereafter the solution was further heated to 100° C. under distillation of the ethyl acetate-water azeotrope. The mixture was cooled and run through a filter where the product (approximately 15 kg) was filtered out.
• the product is a granulate, and investigation in an optical microscope reveals that the aluminum and the explosive are homogenously disbursed in each granule.
• Composition analysis shows that the product contains 87.1% by weight HMX, 5.5% by weight DOA, 2.3% by weight HyTemp and 5.1% by weight aluminum.
• the product is a granulate, and investigation in an optical microscope reveals that the aluminum and the explosive are homogenously disbursed in each granule.
• Composition analysis shows that the product contains 83.3% by weight HMX, 5.6% by weight DOA, 1.8% by weight HyTemp and 9.3% by weight aluminum.
• the product is a granulate, and investigation in an optical microscope reveals that the aluminum and the explosive are homogenously disbursed in each granule.
• Composition analysis shows that the product contains 66.6% by weight HMX, 5.7% by weight DOA, 1.8% by weight HyTemp and 25.9% by weight aluminum.
• the product is a granulate, and investigation in an optical microscope reveals that the aluminum and the explosive are homogenously disbursed in each granule.
• Composition analysis shows that the product contains 63.2% by weight HMX, 5.5% by weight DOA, 1.7% by weight HyTemp and 29.6% by weight aluminum.
• the product is a granulate, and investigation in an optical microscope reveals that the aluminum and the explosive are homogenously disbursed in each granule.
• Composition analysis shows that the product contains 43.4% by weight HMX, 5.5% by weight DOA, 1.9% by weight HyTemp and 49.3% by weight aluminum.
• the product is a granulate, and investigation in an optical microscope reveals that the aluminum and the explosive are homogenously disbursed in each granule.
• Composition analysis shows that the product contains 63.5% by weight RDX, 4.4% by weight DOA, 1.4% by weight HyTemp and 30.7% by weight aluminum.
• the product is a granulate, and investigation in an optical microscope reveals that the aluminum and the explosive are homogenously disbursed in each granule.
• Composition analysis shows that the product contains 59.4% by weight RDX, 10.8% by weight HMX, 7.1% by weight DOA, 2.3% by weight HyTemp and 20.4% by weight aluminum.
• the product is a granulate, and investigation in an optical microscope reveals that the aluminum and the explosive are homogenously disbursed in each granule.
• Composition analysis shows that the product contains 38.6% by weight RDX, 32.4% by weight HMX, 6.9% by weight DOA, 2.3% by weight HyTemp and 19.8% by weight aluminum.
• Example 1 shows that a water slurry process functions very well for a wide range of aluminum content.
• the content of aluminum varies from 5% by weight through 50% by weight aluminum.
• Example 6 shows that the process also functions when HMX is substituted with RDX.
• Example 7-8 show that it is possible to produce granules with a mixmre of RDX and HMX in differing percentages together with aluminum.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Inorganic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Dispersion Chemistry (AREA)
• Molecular Biology (AREA)
• Powder Metallurgy (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=34961739

Family Applications (1)

Country Status (2)

Families Citing this family (2)

Family Cites Families (5)

• 2005
  • 2005-03-17 WO PCT/NO2005/000092 patent/WO2005108329A1/en active Application Filing
  • 2005-03-17 EP EP05722101A patent/EP1756022A1/de not_active Ceased

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events