Production of pyrotechnic delay composition

Abstract

A process for producing a pyrotechnic delay composition includes admixing an oxidizer, a fuel, a surfactant and a liquid, to form a paste or slurry. The paste or slurry is dried to remove the liquid and to obtain a solid product which, if necessary, is rendered into particulate form. Optionally, the solid particulate product is classified to obtain a pyrotechnic delay composition in particulate form.

1 . A process for producing a pyrotechnic delay composition, the process including
 admixing an oxidizer, a fuel, a liquid and a rheology modifier having the ability to alter or modify the burning rate of a delay element made from the delay composition, to form a paste or slurry;   drying the paste or slurry to remove the liquid and to obtain a solid product;   if necessary, rendering the solid product into particulate form; and   optionally, classifying the solid particulate product, to obtain a pyrotechnic delay composition in particulate form.   
     
     
         2 . The process according to  claim 1 , wherein the rheology modifier is in particulate form. 
     
     
         3 . The process according to  claim 2 , wherein the rheology modifier comprises a polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone and/or a powdered smectite clay. 
     
     
         4 . The process according to  claim 2 , wherein the rheology modifier, when admixed with the other solid constituents, is in the form of an aqueous dispersion. 
     
     
         5 . The process according to  claim 1 , wherein the rheology modifier comprises 0.25% to 4%, by mass, of the paste or slurry. 
     
     
         6 . The process according to  claim 5 , wherein the rheology modifier comprises 0.1% to 2%, by mass, of the liquid-containing paste or slurry. 
     
     
         7 . The process according to  claim 1 , wherein the liquid is an organic solvent. 
     
     
         8 . The process according to  claim 1 , wherein the liquid is water. 
     
     
         9 . The process according to  claim 1 , wherein the oxidizer comprises red lead, barium sulphate and/or potassium perchlorate. 
     
     
         10 . The process according to  claim 1 , wherein the fuel comprises silicon, zinc, and/or magnesium. 
     
     
         11 . The process according to  claim 1 , wherein the composition comprises, on a mass basis,
 oxidizer 40-90%   fuel 5-60%   rheology modifier 0.1-2%   
     
     
         12 . A pyrotechnic delay composition, which is in solid particulate form, with the particles comprising an oxidizer, a fuel and a rheology modifier having the ability to alter or modify the burning rate of a delay element made from the delay composition. 
     
     
         13 . A pyrotechnic delay composition according to  claim 12 , which includes, in addition to the rheology modifier, another surfactant. 
     
     
         14 . A pyrotechnic delay composition according to  claim 12 , wherein the rheology modifier comprises a polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone and/or a powdered smectite clay. 
     
     
         15 . A pyrotechnic delay composition according to  claim 12 , wherein the oxidizer comprises red lead, barium sulphate and/or potassium perchlorate. 
     
     
         16 . A pyrotechnic delay composition according to  claim 12 , wherein the fuel comprises silicon, zinc, and/or magnesium. 
     
     
         17 . A pyrotechnic delay composition according to  claim 12 , wherein the composition comprises, on a mass basis,
 oxidizer 40-90%   fuel 5-60% rheology modifier 0.1-2%   
     
     
         18 . A pyrotechnic delay composition according to  claim 12 , which contains no red lead. 
     
     
         19 . The process according to  claim 1 , which includes admixing with the oxidizer and the fuel, another surfactant in addition to the rheology modifier. 
     
     
         20 . The process according to  claim 1 , wherein the pyrotechnic delay composition contains no red lead.