|Title of Invention||
"AN IMPROVED PROCESS FOR THE PREPARATION OF MAGNESIUM BASED IGNITER"
|Abstract||This invention relates to an improved process for the prtepa ra t i on of maqnesium based igniter. The process coeprises in coating magnesius paarticlses with a fiuoroelastomer solution. The coated magnesium particles are drjed and then treated w i t h polytetrafluore ethylene.|
Idiot 1,', di 5~.~trI'.Pi ut ~i'~ of mar;i~'~ him and pot ~ I urn nitrate I~r'r~ irirtit or foim~tlat ir'n~; i~; that it is inr'f fo(~tlvo for r~ Ii'" f tie I r i ch mope I ant ~ thai) the prope] I ants a ,i stated hr' trio above, and ha~ing hi gli degree of fuel—richness
The further disadvantage of the another- cInsr~ of Igniter forniulatlons like, magnesium and fluorocarbon based igniter formulations known in the prior art l~ the neciriven lent method of prepa rat I on thereof and Its I muted area of application.
f3ecausn of these disadvantages of the known igniters and their formuiation~ based on boron, aluminium and maqrir'slum in combination with potassium nitrate, pota~~Ium perelilorate and potassium nitrate respectively each of ~em
ignit:e only one or two classes of propellants due to t~eir tr~itiI t.r'1 cI~arateristic5i by thel r sped fic formulat1on~ and he met; hod of p repa rat i on t he roof
'rho object of the present invention is to propose
an improved magnesium based igniter and a methof or preparation thereof.
Another object of the present invention is to propose a magnesium based igniter, which also comprises of and
polytetrafluoro ethylene and are easy to form and result in powder, pellet and powder-pellet combined form products ready to use for igniting lAte propeitants.
2$ 1 1 a not; her oh jec t; of the present invent i on I s to pt opc~~;e a magnesi urn baSed igniter and the method of preparation tllerrY)r which occupies a small volume and releases energy without: causing excessive pressure peaks in sustained form instantaneously giving conlinous production of the energy as gaseous product which impinges on the propellant, requl red to be ignited with the proposed igni ter of the invention.
Yet another object of the present invention is to propose a magnesium based igniter for all classe5 of propellants, which releese5high heat flux and higher flame temperature to the surface of the propellant, required to be ignited.
According to this invention there is provided an improved process for the preparation of magnesium based igniter which comprises in coating magnesium particles, with a fluoroelastomer solution, drying the coated magnesium particles, treating said dried particles with polytetrafluoro ethylene.
In accordance with the present invention two types of
formulations of the igniter are proposed with magnesium—lean and magnesium—rich compositions. Accordinq to the process (for 100 g of batch Size) of the present invention 25—33 g of iiiw preferably 30-33 g of magnesium preferably in
spherical shape of particle size of 30—60 microns preferably of 35-50 microns is allowed to react in first step of the process with 2-10 g of fluoroelastomer preferably 4—6 g of this elastomer is dissolved in 40-60 ml of low boiling organic solvent preferably acetone for 10—15 minutes. The resulted product, which in turn is coated magnesium is spreaded in metallic tray to form a 2-4 mm thick layer and is dried at room temperature for 2-3 hrs. The dried product is passed through a higher size of mesh preferably 30 mesh which results into powder form of the product which in turn is allowed to react in second step of the process with 60-70 g preferably 63—65 g of polytetrafluoroethylene of specific particles size ranging upto 60 micron more preferably 20 micron to 40 micrcm for 15-25 minutes. The resulted formulation as referred here as magnesium lean igniter formulat ion.
According to the another preferred embodiment of the present invention the another preferred formulation is prepared on reaction of reactants 65—75 g, preferably 72.5 to
73.5 g, of magnesium and 5—15 g, preferably 10—12 g of fluoroelastomer which are allowed to react in first step and subsequently the resulted coated product is allowed to react with 10—20 g, preferahly 15—17 g of polytetrafluoroethylene an second step of the proposed process of the invent ion. The resu lted formu 1 ati on is referred here as magnesium—ri (11 igniter formulation.
The synthetic formulations, like magnesium-lean and magnesaum-r~ch formu 1 ati ons as stated herein above, were prepared according to the preferred embodiments of the present invention, and were reacted on to the surfaces of various classes of propellants, required to be ignited. The following description as intended to disclose the method of
US rig tho said formulations and it Is clear from the following examples that the proposed formulations are suitable in powder, arid or pellet forms ann can ignite the all most all clas~;es of propellants like met;al—base propellants, double base propellants, composite propellants, composite modified double base propellants and hydrocarbon based propellarits.
According to preferred embodiment of the present invention 1 g of magnosium-rich formulation is pelleted with a pellet making machine to a size of 8mm diameter and 5mm
thickness at a compaction load of preferably 700-900 kg/cm. According the process of the present invention, to ignite
metal based fuel rich propellants of 100 mm diameter, 4—5 pellets of magnesium rich igniter formulation packed in a cambric cloth bag aiongwith a squibb is kept on the propellant ignition surface and ignited with I amp electric current. Reaction products of this igniter consistinq of hot part:icles of magnesium (hg), magnesium fluoride (1 ig/gaseous) impinge on the propellant surface at a sustained rate and in turn transfer heat to the propellant surface facilitating ignition.
It is anr,ther preferred embodiment of the process of the present invention to ignite double base propellants of 100 mm diameter, 3—4g of magnesium-lean composition in powder form packed in cambric cloth bag alongwith a squl Hi is kept on propel lant ignit ion surface and igni t;ed with I amp. e I octric current . Th '~ react i on products on iqn it i n of th' forrnryl ati on yi Ql d hi 'Ocr gaseous exhaust products it
temperature compr i si ni of magnes i tim fluoride (1 ig/gaseous) carbon tetrafi uoride (gaseou'j , carbon di fl uoride (gaseous) arid carbon (sol id)
According to sf i I I another preferred enubod I rnc'rit of t;iw' process of the present invention to iqn i t;e compos i t:
propellants, composifo modified double base propel lants arid hydrocarbon based fuel—rich propellants, i() to 12 g of
i 'in it ('I I o mui at inns coiv; ist 1 nq (if bot.h I ike 2—3 q of the f m in uf niar~nes i urn--I ean I ormul al on and 8—9 ~i of t hr
pr I I ri fm in of mignes1 urn—ri oh formulation are used. The 'art i ~n ~t oducts on iqnj t;i on of the igniter formtilat.ion
comprises of magnesium (Ii q) , magnesium fluoride
(1 i ~u i rl/qasrous) , carbon tetra I luoride (gaseous) and carbon (sol iii) , and ignite these (lasses of propellants.
1) An improved process for the preparation of magnesium
based igniter which comprises in coating magnesium particles,
with a fluoroelastomer solution, drying the coated
magnesium particles, treating said dried particles with
2) A process as claimed in claim 1 wherein said
magnesium particles have a size of 30-60 microns,
and preferably 35-50 microns.
3) A process as claimed in claim 1 wherein said
magnesium particles are coated with 2-10 g, preferably
4-6 g of fluoroelastomer preferably dissolved to every
40-60 ml of low boiling organic solvent such as acetone.
4) A process as claimed in claim 1 wherein said
second step of said reaction of said dried coated
magnesium is treated with 60-70 g, preferably 63-65 g
5) A process as claimed in claims 1 to 4 wherein
said polytetrafluoroethylene has a particle size upto
60 microns more preferably 20 microns to 40 microns
for 15-25 minutes.
6) A process as claimed in claims 1,2 and 5 wherein
said formulation and the method of 65-75 g, preferably
72.5-73.5 g of magnesium is present to every and
5-15 g, preferably 10-12 g of fluoroelastomer in said step of coating, the dried coated magnesium treated with 10-20 g, preferably 15-17 g of polytetrafluoroethylene.
7) An improved process for the preparation of
magnesium based igniter substantially as herein
8) An magnesium based igniter whenever made by a
process as claimed in claim 7.
|Indian Patent Application Number||32/DEL/1996|
|PG Journal Number||09/2008|
|Date of Filing||05-Jan-1996|
|Name of Patentee||THE CHIEF CONTROLLER, RESEARCH & DEVELOPMENT MINISTRY OF DEFENCE|
|Applicant Address||TECHNICAL COORDINATION DTE., DEFENCE RESEARCH & DEV. ORGN., B-341, SENA BHAWAN, DHQ P.O. NEW DELHI 110011. INDIA|
|PCT International Classification Number||C06B 45/10|
|PCT International Application Number||N/A|
|PCT International Filing date|