Resin Cured Binary Explosive

Abstract

The devices and methods described below provide for a plasticized, adhesive binary explosive mixture formed with nitromethane (NM) plasticized with nitrocellulose (NC) as an energetic component and a urethane resin mixed with any suitable mechanical sensitizer as the sensitizer component. The addition of the sensitizer component to the plasticized component of NM/NC causes the resulting gel mixture to become explosive while maintaining stability.

Description

FIELD OF THE INVENTIONS

The inventions described below relate to the field of energetic materials, more specifically nitroalkane based binary explosives.

BACKGROUND OF THE INVENTIONS

A binary explosive mixture is an explosive composition produced by the combination of two components just prior to use and for which each component is non-detonable under normal industrial practices. There are many two and three component binary explosives using a solid or liquid fuel and a solid or liquid oxidizer that becomes explosive upon mixing the fuel and oxidizer components. There are many problems with conventional binary explosives and one of the most inconvenient is that they need to be mixed and used in a closed container.

Nitrocellulose (NC) is an energetic plasticizer which is not considered an explosive when the nitrogen content is <12.6%. NC diluted in a solvent (no more than 55% NC or wetted with water-no less than 25% water) is considered a flammable liquid or solid respectively according to the United States Department of Transportation. Conventionally NC is not suitable for use in nitroalkane based binary explosive use because amines are often used in nitroalkane based binary explosives as sensitizers. The addition of amines to nitrocellulose can be hazardous and may cause deflagration.

SUMMARY

The devices and methods described below provide for a plasticized, adhesive binary explosive having a energetic component formed by the combination of nitromethane (NM) or other suitable nitroalkane chemical combined with nitrocellulose as an energetic plasticizer to form a non-detonable energetic component. An optional stabilizer chemical, for example, retinyl acetate (RA) or any other suitable explosive stabilizer, may be added to the energetic component for stability. This non-detonable energetic component may be sensitized by the addition of a sensitizer component formed of a urethane resin chemical and any suitable mechanical sensitizer. The addition of the urethane resin enables the formation of polyurethane through the reaction between the isocyanate group (R—N═C═O) of the urethane resin and the non-nitrated hydroxyl groups (R—OH) on the nitrocellulose. Addition of a physical sensitizer such as (microballoons, suitable metal powders, or any suitable combination of the two) produces a detonable solid upon mixing. The addition of the mechanical sensitizer to the plasticized or gelatinized energetic component causes the mixture of the plasticized or gelatinized component and sensitizer component to become explosive while maintaining stability. Curing times can be tailored to meet specific requirements by utilization of optional different urethane resins.

Additionally, various diols (butane diol, ethylene glycol, etc.) may be optionally included in the energetic component to modify the curing characteristics of the explosive gel mixture. The end result is a highly customizable binary explosive mixture displaying properties that range from a runny gel to a stiff rubber like consistency.

The advantage of this explosive mixture is that it is adhesive to surfaces however they are oriented and could be used in a variety of applications including explosive breaching. For example, on vertical surfaces or on the underside of horizontal surfaces. Additional benefits include the fact that the NM/NC energetic gel component is non-explosive (as is the sensitizer component of urethane and microballoons/metal powders) while the energetic component and the sensitizer component are separated) which greatly simplifies shipping and storage. It also increases safety for the user due to the fact that they will not have to transport high explosives on their person or in their vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-section view of a binary component dispensing tube with a first mixer nozzle.

FIG. 2 is a cross-section view of the binary component dispensing tube of FIG. 1 with a stabilized energetic component.

FIG. 3 is a cross-section view of the binary component dispensing tube of FIG. 1 with a diol treated energetic component, an alternate sensitizer component and a second mixing tip.

FIG. 4 is a cross-section view of the binary component dispensing tube of FIG. 1 with a stabilized diol treated energetic component, an alternate sensitizer component and a second mixing tip.

DETAILED DESCRIPTION OF THE INVENTIONS

Referring to FIGS. 1, 2 and 3, a plasticized, adhesive binary explosive mixture 3 is formed using nitromethane which is plasticized to form energetic gel component 1 by the addition of non-explosive nitrocellulose which has <12.6% nitrogen. This plasticized or gelatinized energetic gel component 1 is prepared by addition of 5-30% NC into the NM with use of any suitable stirrer such as a high shear stirrer. The higher the percentage of NC relative to the NM will increase the viscosity of the energetic component 1.

The addition of 0.5-20% of a sensitizer component 2 which is any suitable urethane resin 2A combined with any suitable mechanical sensitizer 2B (such as microballoons, any suitable metal powders, or any suitable combination of the two) to the plasticized/gelatinized mixture of nitromethane/nitrocellulose (NM/NC), energetic component 1, produces explosive gel mixture 3. The mass of NC is measured as a percentage of the mass of the NM. The mass of the RA is measured as a percentage of the NC, while the mass of the sensitizer component 2 is measured as a percentage of energetic component 1. Explosive gel mixture 3 is adhesive to surfaces in any orientation and could be used in a variety of applications including explosive breaching avalanche control, unexploded ordinance disposal and mining. Additional benefits include the fact that the energetic component 1, or stabilized NM/NC gel 1S, is non-explosive which greatly simplifies shipping, storage and transportation. As illustrated in FIG. 2, as an option, any suitable explosive stabilizer, such as for example retinyl acetate 4 (RA), Diethyldiphenylurea, Dimethyldiphenylurea, Methyldiphenylurea, or Triphenylamine, may be added to energetic component 1 to form stabilized energetic component 1S which forms stabilized binary explosive mixture 3S.

Suitable urethane (isocyanate/diisocyante) resins for sensitizer component 2 might be selected from the following urethanes: the active isocyanate monomers include toluene diisocyanate (TDI), methylene diphenyl isocyanate (MDI), 1,6-hexamethylene diisocyante (HDI), 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethyl-cyclohexane (isophorone diisocyante/IPDI) and 4,4′-diisocyanato dicyclohexylmethane (H₁₂MDI).

The addition of a mechanical sensitizer 2B such as glass microballoons and/or powdered metal increases the energy output of the resulting explosive gel mixture 3 or 3S. Suitable metal powders include aluminum powder (spherical and/or flake), magnesium powder, zirconium powder, boron powder, silicon powder and titanium hydride powder. Modification of the urethane resin mechanical sensitizer mixture with various metal powders, microballoons or combinations of metal powders and/or microballoons allows for the manipulation of the shock impulse of the detonation. For example, the detonation may be manipulated by the choice of mechanical sensitizers to produce a sharp breaking impulse or a slower pushing impulse by the selection of the mechanical sensitizer mixture.

The curing time of explosive gel mixtures 3 or 3S can be tailored to meet specific requirements by the use of one or more preselected urethane resins to form resin 2R to form an alternate sensitizer component 2X. Additionally, various chemicals such as any suitable diol 6, for example, butane diol, ethylene glycol, etc. may be optionally included in the energetic component 1 or the stabilized energetic component 1S to modify the curing characteristics of the explosive gel mixture to form gel 3A or 3AS as illustrated in FIGS. 3 and 4. The end result is a highly customizable binary explosive mixture displaying properties that range from a runny gel to a stiff rubber like consistency.

In use, a user would combine the plasticized energetic component 1, 1S, or 1X of NM/NC with sensitizer component 2 or 2X forming the explosive mixture, gel 3, 3A, 3S or 3XS. The explosive mixture is detonated using any suitable detonator such as a standard blasting cap. The plasticized NM/NC energetic component 1 may be contained in one tube of a binary component applicator 10 with a dual plunger and any suitable mixing nozzle such as mixing nozzle 11 or optional mixing tip 12 and the selected sensitizer component 2 may be contained in an adjacent tube of the applicator. Compressing the dual plunger on the binary component applicator will inject proportional amounts of the plasticized NM/NC, component 1, and the selected sensitizer component 2 into the mixing nozzle 11. Plasticized, adhesive binary explosive flows from the mixing nozzle producing a bead of adhesive high explosive gel mixture 3. Securing a detonator such as a blasting cap into the plasticized, adhesive binary explosive gel 3 will enable the binary explosive mixture to be detonated when the detonator is initiated.

The color of the energetic component 1, 1S or 1X and a suitable sensitizer component such as sensitizer component 2 or 2X are sufficiently different that it is possible to distinguish plain plasticized NM/NC from a sensitized and explosive mixture, such as gels 3, 3A, 3S or 3XS. Mixing the energetic component and the sensitizer component causes a distinct color change that indicates the two component have been mixed and activated as gel 3, 3A, 3S or 3XS. Once activated the mixture, gel 3, 3A, 3S or 3XS, is sensitive to a standard blasting cap.

While the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the inventions. The elements of the various embodiments may be incorporated into each of the other species to obtain the benefits of those elements in combination with such other species, and the various beneficial features may be employed in embodiments alone or in combination with each other. Other embodiments and configurations may be devised without departing from the spirit of the inventions and the scope of the appended claims.

Claims

1. A binary explosive comprising:

an energetic component comprising nitromethane mixed with nitrocellulose having less than 12.6% nitrogen to form plasticized nitromethane/nitrocellulose; and

a sensitizer component comprising a urethane resin combined with any suitable mechanical sensitizer selected from the group microballoons, aluminum powder, magnesium powder, zirconium powder, boron powder, silicon powder or titanium hydride powder.

2. The binary explosive of claim 1 wherein the energetic component further comprises an explosive stabilizer.

3. The binary explosive of claim 1 wherein the energetic component further comprises a diol.

4. The binary explosive of claim 2 wherein the energetic component further comprises a diol.

5. The binary explosive of claim 3 wherein the diol is butane diol.

6. The binary explosive of claim 3 wherein the diol is ethylene glycol.

7. The binary explosive of claim 4 wherein the diol is butane diol.

8. The binary explosive of claim 2 wherein the explosive stabilizer is selected from the group, retinyl acetate, diethyldiphenylurea, dimethyldiphenylurea, methyldiphenylurea, or triphenylamine.

9. A nitroalkane mixed with nitrocellulose having less than 12.6% nitrogen to form plasticized gel, the plasticized gel combined with a sensitizer component comprising:

a urethane resin combined with any suitable mechanical sensitizer selected from the group microballoons, aluminum powder, magnesium powder, zirconium powder, boron powder, silicon powder or titanium hydride powder

10. The plasticized gel and a sensitizer component of claim 9 wherein the suitable mechanical sensitizer comprises a first portion of microballoons and a second portion of metal powder selected from the group aluminum powder, magnesium powder, zirconium powder, boron powder, silicon powder or titanium hydride powder.

11. The plasticized gel and a sensitizer component of claim 9 wherein the sensitizer component is an alternate sensitizer component with preselected urethane components.

12. The plasticized gel and a sensitizer component of claim 9 wherein the plasticized gel further comprises a diol.

13. The plasticized gel and sensitizer component of claim 11 wherein the plasticized gel further comprises a diol.

14. The plasticized gel and sensitizer component of claim 12 wherein the diol is butane diol.

15. The plasticized gel and sensitizer component of claim 12 wherein the diol is ethylene glycol.

16. The plasticized gel and sensitizer component of claim 13 wherein the diol is butane diol.

17. The plasticized gel and sensitizer component of claim 13 wherein the diol is ethylene glycol.

18. A binary explosive mixture comprising:

an energetic component comprising nitromethane mixed with nitrocellulose having less than 12.6% nitrogen, a diol, and an explosive stabilizer to form plasticized nitromethane/nitrocellulose; and

a sensitizer component comprising a urethane resin and any suitable mechanical sensitizer selected from the group microballoons, aluminum powder, magnesium powder, zirconium powder, boron powder, silicon powder or titanium hydride powder.

19. The binary explosive mixture of claim 18 wherein the explosive stabilizer is selected from the group, retinyl acetate, diethyldiphenylurea, dimethyldiphenylurea, methyldiphenylurea, or triphenylamine.

20. The binary explosive mixture of claim 18 wherein the diol is ethylene glycol.