Title of Invention

"A PROCESS FOR THE PREPARATION OF FREE FLOW RDX POWDER"

Abstract

This invention relates to a process for the preparation of the free flow RDX powder for use for the manufacture of a detonsting cord. According to this process the explosive for example RDX/HMX powder is treated with cationic/non—ionic surfactant and polyelectrolytes at ambient temperature for a period of 1 to 9 hours- The treated explosive is then mixed with solid power material in order to enhance the flow characteristices of the explosive powder.

Full Text

This invention relates to a process for the preparation of free flow RDX powder for use in manufacture of detonating cord. Though the reference has been made to cyclotrimethylene trinitramine, the process is useful to prepare free flow HMX explosive material also. The detonating cord is an explosive device used to transmit detonation wave front from one point to another point to initiate single or multiple charges at a time. The cord is widely used in mining and to initiate shaped charge explosives in the perforation of oil wells in oil fields. The detonating cords are prepared either by a dry process or a wet process as such known in the art. There are disadvantages associated with the known processes for the manufacture of detonating cord. One of the main disadvantages is that dry process is applicable only to the explosive which are in the form of powder capable to flow freely for example Pentaery thritol Tetranitrate. However, this process is not suitable to prepare the detonating cord from the fine powder of Cyclotimethylene trinitramine/and HMX explosives. Therefore, to prepare the detonating cord of Cyclotimethylene trinitramine the wet process is used. The main disadvantage with the wet process is that the slurry of the explosive is encased by using a braiding machine and which is a very slow and cumbersome process. Also pnuematic pressure is required to convert the slurry into the Cylindrical Core explosive. Another disadvantage is that the consistency and performance of the cord is reduced due to absorption of the traces of the solvent onto the explosive. Yet another disadvantage is that this process is not useful for preparing the detonating cord of large volume as required. Further the process is very costly. Therefore the main object of this invention is to propose a process for the preparation free-flow RDX powder. Another object of this invention is to propose a free flowing RDX powder for use in a dry process for the manufacture of detonating cord which is an easy process. Yet another object of this invention is to propose a process for the preparation of a free flowing RDX powder which is safe in handling during the preparation of the detonating cord. According to this invention there is provided a process for the preparation of the free flow RDX powder for use in the manufacture of detonating cord characterised by the step of treating the explosive for example RDX/HMX powder with cationic/non-ionic surfactant and polyelectrolytes at ambient temperature for a period of 1 to 8 hours and mixing said treated explosive with solid powder material in order to enhance the flow characteristics of the explosive powder. In accordance with this invention the high explosive material such as Cyclotimethylene trinitramine (RDX) or HMX is first treated with the cationic/non-ionic surfactant for example (1) Cetylpyridenium Chloride, (2) Cetyltrimethyl ammonium bromide, (3) Alkyl dimethyl bezyl ammonium chloride, (4) Poly-4-vinyl pyridine and/or (5) Dodecyl 1,1,1 N trimethyl ammonium chloride, polyelectrolytes for example (1) Poly propoxy-quaternary ammonium chloride, (2) Poly (diallyldimethyl ammonium chloride) and/or (3) Poly (2-hydroxy propyl-1, IN dimethyl ammonium chloride) to impart improved flow and anti static properties to the explosive material. A conventional dye is added during the step of treatment to impart the colour of the to explosive. The treated explosive material is further treated with one or more solid powder material such as hydro-phobic or percipited silica, aluminium tristearate, and calcium distearate to further enhance the flow characteristics of the explosive. According to an option the oxidising salts such as potassium nitrate, sodium nitrate and/or barium peroxide, in the fine powder form is added to increase the velocity of detonation and efficiency of combustion. The treated dry explosive is filled in a funnel and is allowed to flow under gravity to form a core into a cylindrical tube which is formed from Polytetra fluro ethylene or Poly ethylene tape by passing the same through a dye under the funnel simultaneously, during core formation. The tube core so formed is wrapped with polystyrene or rayon or polyester yarn from 8-10 spindle plate as secondary yarn and the core tube is further wrapped from a spindle plate to provide the outer primary wrapp over the cylindrical core explosive. The cylindrical core explosive so obtained is then subjected to the step of extrusion with nylon for coating the cylindrical core. A process for the preparation of free flowing Cyclotimethylene trinitramine powder for the manufacture of the detonating cord is herein described in detail and illustrated in the following examples. The process for the preparation of -free flawing RDX powder comprises in treating explosive materials such as RDX or HMX with surfactants and polyelectrolytes. For this purpose 1 parts of explosive material RDX powder of the size which passes through the 36 mesh and does not passes through 3 mesh is treated with .1 to .3 parts of surfactant for example (i) Cetylpyridenium chloride, (2) Cetyltrimethyl ammonium bromide, (3) Alfcyl dimethyl bezyl ammonium chloride, (4) Poly-4-vinyl pyridine and/or (5) Dodecyl 1,1,1 N trimethyl ammonium chloride- .05 to .15 parts of polyelectrolytes for example (1) Poly propoxy-quaternary ammonium chloride, (2) Poly (diallyldimethyl ammonium chloride) and/or (3) Poly (2-hydroxy propyl-I, IN dimethyl ammonium chloride* and .0*31 to .05 parts of dye for example Rasamiline in aqueous phase using 100 parts of water at ambient temperature for a period of i. to 8 hours under constant slow stirring. The polyelectrolyte, surfactant and the dye are first dissolved in water and the RDX is then added in the water mixture to get aqueous suspension. The pH is adjusted between 6.5 to 7.5. The aqueous mixture is then filtered to get wet RDX powder which is subjected to the step of air drying at 5 to 6"C so as to have moisture level less than 1PPM. The dried free flow RDX powder is sieved through a 36 mesh. The sieved powder is then further mixed/treated with ,3 to 0.1 part of solid powder material for example hydro-phobic or percipited silica, aluminium tristearate, and calcium distearate to get mare free flow RDX powder useful to prepare RDX cord by a dry process. The free flaw RDX/HMX powder is obtained due the synergetic effect during the treatment process of the explosive material. According to an option RDX explosive is treated with surfactant or polyelectrolyte alone or in combination the manner herein above described for use of the explosive for the preparation of propellants and cast explosive devices but not. for the preparation of RDX cord. EXAMPLE 1 1 parts of diallyldimethyl ammonium chloride, 2 parts of cetyl trimethyl ammonium bromide and .4 parts of dye (Rosamiline) were dissolved in 2 parts of water to get a clear solution. 2000 parts of RDX was added to the water solution to prepare an aqueous slurry at the room temperature. The slurry was kept under slow agitation or stirring for 3 hours and the pH was adjusted to 7. The slurry so obtained was filtered and air dried at 60"C -for 4 hours to obtain a moisture content less than 1PPM. The dried RDX was sieved through 36 mesh and the powder so obtained was mixed throughly with i parts o-f hyrophobic silica to get free flow RDX powder - The RDX powder was used to prepare 17gm/meter and 0.5 gm/aieter deteonating cords by the dry process and was subjected to the extrusion coating step with nylon to get the -final cord. The cords were tested and the velocity of detonation was found 7900+-S0 meter per second and 7500 + 83 meter/sec. which were higher than the conventional cord preapared by wet process. EXftHFLE 2 1.5 parts of paly temperature. The slurry was kept under slow agitation or stirring for 4 hours and the pH was 7.2. The slurry so obtained was filtered and air dried at 55°C for 8 hours to obtain a moisture level below 1PPM. The dried RDX was sieved through 36 mesh and the powder so obtained was mixed throughly with .8 parts of a mixture of aluminium tristearate and precipitated silica in the ratio of 1;3 to get free flow RDX powder. The RDX powder was used to prepare a 17gm/meter detonating cord by the dry process and was subjected to the extrusion coating step with nylone to get the final cord. The cord was tested and the velocity of detonation (VQD> was found 785+5 meter per second which is higher than the conventional cord preapared by wet process. EXAMPLE 3 1.25 parts propoxy quaternary ammonium chloride, 2.5 parts of a mixture of poly 4-vinyl pyridine and lodeeyl 1,1,1 trimethyl ammonium chloride in the ratio of 2:3 and .75 parts dye were dissolved in 2 parts of water to get a clear solution. 25 parts of RDX was added to the water solution to prepare an aqueous slurry at the room temperature. The slurry was kept under slow agitation for 3 hours and the pH was 6.8. The slurry so obtained was filtered and air dried at 60"C for 4 hours to moisture level less than 1PPM. The dried RDX was sieved through 36 mesh and the powder so obtained was mixed throughly with 1-5 parts of a Isi mixture of hydrophobic silica and calcium distearate to get free flow RDX powder. The nylon coated card prepared in 17 and 8.5 gm/snetet- gave velocity of detonation 79+5 and 7500+-80meter/second respectively. WE CLAIM: 1. A process for the preparation of the free flow RDX powder for use in the manufacture of detonating cord characterised by the step of treating the explosive for example RDX/HMX powder with cationic/non-ionic surfactant and polyelectrolytes at ambient temperature for a period of 1 to 8 hours and mixing said treated explosive with solid powder material in order to enhance the flow characteristics of the explosive powder. 2. A process as claimed in claim 1 wherein 100 parts of cyclotrimethylene trinitramine (RDX) is treated with 0.1 to 0.3 parts of surfant, 0.05 to .15 parts of polyelectrolyte and .001 to 0.005 parts of dye in an aqueous phase using 100 parts of water. 3. A process as claimed in claim 1 wherein said step of treating is carried on under constant slow agitation/stirring. 4. A process as claimed in any of the claims 1 to 3 wherein the pH of the mixture is adjusted in between 6.5 to 7.5. 5. A process as claimed in claim 1 wherein said surfactant comprises (1) Cetylpridimium chloride, (2) Cetyltrimethyl ammonium bromide, (3) Alkyl dimethyl bezyl ammonium chloride, (4) Poly-4-vinyl pyridine and/or (5) Dodecyl 1,1,1 trimethyl ammonium chloride. 6. A process as claimed in claim 1 wherein said polyelectrolytes comprises (1) Poly propoxy-quaternary ammonium and/or (3) Poly (2-hydroxy propyl-1, IN dimethyl ammonium chloride). 7. A process as claimed in claim 1 wherein said solid powder material comprises 0.03 to 0.1 parts of one or more hydrophobic or precipitated silica, aluminium tristerate and calcium distearate. 8. A process as claimed in claim 1-7 wherein fine powder of potassium nitrate, sodium nitrate and/or barium per oxide is mixed with said free explosive to increase the VOD and combustion of the detonating cord. 9. A process as claimed in claim 1 wherein said RDX powder is treated with surfactant or electrolyte alone or in combination thereof. 10. A process for the preparation of the free flow RDX powder for use for the manufacture of a detonating cord substantially as herein described and illustrated.

Documents:

1787-DEL-1996-Abstract.pdf

1787-DEL-1996-Claims.pdf

1787-del-1996-complete specification (granted).pdf

1787-DEL-1996-Correspondence-Others.pdf

1787-DEL-1996-Correspondence-PO.pdf

1787-del-1996-descripiton (provisional).pdf

1787-del-1996-description (complete).pdf

1787-DEL-1996-Form-1.pdf

1787-DEL-1996-Form-19.pdf

1787-DEL-1996-Form-2.pdf

1787-DEL-1996-Form-3.pdf

1787-DEL-1996-Form-5.pdf

1787-DEL-1996-Form-6.pdf

1787-DEL-1996-GPA.pdf