Use of a tetraphenylphosphonium halogenated salt as smoke-producing agent and smoke-producing pyrotechnic composition incorporating such a material

Abstract

Disclosed is the use of at least one tetraphenylphosphonium halogenated salt as smoke-producing agent in a pyrotechnic composition designed to ensure masking of a target with regard to electromagnetic radiation in a given wavelengths range. Also disclosed is also a smoke-producing pyrotechnic composition including at least one tetraphenylphosphonium halogenated salt.

1 . A method to mask a target with regard to electromagnetic radiation in a given wavelengths range, comprising providing a pyrotechnic composition comprising at least one tetraphenylphosphonium halogenated salt as a smoke-producing agent, and applying the composition to mask the target. 
     
     
         2 . The method according to  claim 1 , wherein the tetraphenylphosphonium halogenated salt used is tetraphenylphosphonium bromide. 
     
     
         3 . The method according to  claim 1  in order to obtain masking with a camouflage coefficient above 45% for a duration of at least 90 seconds. 
     
     
         4 . Smoke-producing pyrotechnic composition intended to mask a target with regard to electromagnetic radiation in a given wavelengths range and comprising at least one energetic material, such as a reduction-oxidation couple, as well as at least one smoke-producing agent generating masking particles, the composition comprising as smoke-producing agent at least one tetraphenylphosphonium halogenated salt. 
     
     
         5 . The composition according to  claim 4 , comprising as smoke-producing agent tetraphenylphosphonium bromide or tetraphenylphosphonium iodide. 
     
     
         6 . The composition according to  claim 5 , comprising as energetic material a reduction-oxidation couple associating, as a reductant, a metallic powder and, as an oxidant, a fluoropolymer. 
     
     
         7 . The composition according to  claim 6 , wherein the fluoropolymer is a fluoropolymer having in its molecular structure a fluorine percentage above 60%. 
     
     
         8 . The composition according to  claim 6 , comprising at least one reductant selected from among the following bodies: magnesium, aluminium, zirconium, titanium, calcium silicide, boron. 
     
     
         9 . The composition according to  claim 6 , comprising at least one oxidant selected from among the following bodies: vinylidene fluoride and hexafluoropropylene dipolymer, polytetrafluoroethylene, tetrafluoroethylene or their mixtures. 
     
     
         10 . The composition according to  claim 6 , comprising at least one chlorinated compound in a proportion below 10% in mass. 
     
     
         11 . The composition according to  claim 10 , comprising at least one organochlorinated compound with a chlorination rate above 60%. 
     
     
         12 . The composition according to  claim 4 , comprising:
 10% to 40% in mass of energetic material,   90% to 60% in mass of smoke-producing agent,   0% to 10% in mass of chlorinated agent,   0% to 8% in mass of binding agent.   
     
     
         13 . The composition according to  claim 12 , wherein the binding agent consists of at least one epoxy-type resin added in a proportion of approximately 5% of the overall mass of the bloc. 
     
     
         14 . The composition according to  claim 12 , comprising:
 12% in mass of magnesium powder,   18% in mass of vinylidene fluoride and hexafluoropropylene dipolymer,   63% in mass of tetraphenylphosphonium salt,   7% in mass of chlorinated agent.   
     
     
         15 . The composition according to  claim 12 , comprising:
 12% in mass of magnesium powder,   12% in mass of vinylidene fluoride and hexafluoropropylene dipolymer,   69% in mass of tetraphenylphosphonium salt,   7% in mass of chlorinated agent,   5% in mass of epoxy resin.   
     
     
         16 . The composition according to  claim 12 , comprising:
 15% in mass of magnesium powder,   15% in mass of vinylidene fluoride and hexafluoropropylene dipolymer,   69% in mass of tetraphenylphosphonium salt,   5% in mass of epoxy resin.   
     
     
         17 . The composition according to  claim 12 , comprising:
 15% in mass of magnesium powder,   15% in mass of vinylidene fluoride and hexafluoropropylene dipolymer,   62% in mass of tetraphenylphosphonium salt,   7% in mass of chlorinated agent,   5% in mass of epoxy resin.   
     
     
         18 . The composition of  claim 12 , wherein the mass of the energetic material is 20% to 30%. 
     
     
         19 . The composition of  claim 18 , wherein the mass of the smoke-producing agent is 60% to 70%. 
     
     
         20 . The composition of  claim 19 , wherein the mass of the chlorinated agent is 0 to 7%.