Phosphate stabilization of basic copper nitrate

Abstract

An improved gas generant composition is provided which contains components including basic copper nitrate, at least one fuel material and a phosphate stabilizer, wherein the phosphate stabilizer inhibits moisture induced deleterious interaction between the basic copper nitrate and other components of the gas generant composition.

1 . In a gas generant composition comprising components including basic copper nitrate and at least one fuel material, the improvement comprising: 
 a phosphate stabilizer, wherein the phosphate stabilizer inhibits moisture induced deleterious interaction between the basic copper nitrate and other of the gas generant composition components.    
   
   
       2 . The gas generant composition of  claim 1  wherein the phosphate stabilizer is present in a concentration of at least about 1 part by weight phosphate per about 770 parts by weight basic copper nitrate.  
   
   
       3 . The gas generant composition of  claim 1  wherein the phosphate stabilizer is present in a concentration of from about 1 part by weight phosphate per about 770 parts by weight basic copper nitrate to about 1 part by weight phosphate per about 15 parts by weight basic copper nitrate.  
   
   
       4 . The gas generant composition of  claim 1  wherein the phosphate stabilizer is present in a concentration of from about 1 part by weight phosphate per about 770 parts by weight basic copper nitrate to about 1 part by weight phosphate per about 150 parts by weight basic copper nitrate.  
   
   
       5 . The gas generant composition of  claim 1  wherein the phosphate stabilizer is selected from the group consisting of tetrasodium pyrophosphate, sodium phosphate dibasic, phosphoric acid and combinations thereof.  
   
   
       6 . The gas generant composition of  claim 1  wherein the phosphate stabilizer comprises tetrasodium pyrophosphate.  
   
   
       7 . The gas generant composition of  claim 1  wherein the phosphate stabilizer inhibits moisture induced deleterious interaction between the basic copper nitrate and the fuel material.  
   
   
       8 . The gas generant composition of  claim 1  wherein the fuel material comprises a transition metal nitrate complex.  
   
   
       9 . The gas generant composition of  claim 1  wherein the other gas generant composition components further comprise at least one burn rate enhancer.  
   
   
       10 . The gas generant composition of  claim 9  wherein the phosphate stabilizer inhibits moisture induced deleterious interaction between the basic copper nitrate and the burn rate enhancer.  
   
   
       11 . The gas generant composition of  claim 9  wherein the bum rate enhancer comprises a transition metal complex of a tetrazole containing at least one ammine-containing ligand.  
   
   
       12 . The gas generant composition of  claim 1  comprising: 
 about 10 to about 60 composition weight percent basic copper nitrate;    about 10 to about 50 composition weight percent of at least one fuel material; and    a phosphate stabilizer present in a concentration of about 1 part by weight phosphate per about 770 parts by weight basic copper nitrate to about 1 part by weight phosphate per about 150 parts by weight basic copper nitrate.    
   
   
       13 . A stabilized gas generant composition comprising: 
 a fuel;    a burn rate enhancer including a transition metal complex of tetrazole containing at least one ammine-containing ligand;    basic copper nitrate oxidizer; and    a phosphate stabilizer,    wherein the phosphate stabilizer inhibits moisture induced deleterious interaction between the basic copper nitrate and the transition metal complex of tetrazole containing at least one ammine-containing ligand.    
   
   
       14 . The stabilized gas generant composition of  claim 13  wherein the phosphate stabilizer is present in a concentration of from about 1 part by weight phosphate per about 770 parts by weight basic copper nitrate to about 1 part by weight phosphate per about 15 parts by weight basic copper nitrate.  
   
   
       15 . The stabilized gas generant composition of  claim 13  wherein the phosphate stabilizer is tetrasodium pyrophosphate.  
   
   
       16 . The stabilized gas generant composition of  claim 15  wherein the tetrasodium pyrophosphate is present in a concentration of at least about 0.1 composition weight percent.  
   
   
       17 . The stabilized gas generant composition of  claim 15  wherein the tetrasodium pyrophosphate is present in an amount of from about 0.1 to about 5 composition weight percent.  
   
   
       18 . The stabilized gas generant composition of  claim 15  wherein the tetrasodium pyrophosphate is present in an amount of about 0.1 to about 0.5 composition weight percent.  
   
   
       19 . The stabilized gas generant composition of  claim 13  wherein the fuel comprises guanidine nitrate.  
   
   
       20 . The stabilized gas generant composition of  claim 13  wherein the burn rate enhancer is selected from the group consisting of copper diammonium bitetrazole, copper ethylenediamine bitetrazole and combinations thereof.  
   
   
       21 . The stabilized gas generant composition of  claim 13  further comprising a metal oxide burn rate enhancing and slag formation additive.  
   
   
       22 . The stabilized gas generant composition of  claim 13  comprising: 
 about 10 to about 50 composition weight percent fuel;    about 10 to about 60 composition weight percent basic copper nitrate;    at least about 10 composition weight percent burn rate enhancer; and    a phosphate stabilizer present in a concentration of about 1 part by weight phosphate per 770 parts by weight basic copper nitrate to about 1 part by weight phosphate per 150 parts by weight basic copper nitrate.    
   
   
       23 . A method for making the stabilized gas generant composition of  claim 13  comprising the steps of: 
 preparing an aqueous slurry including the fuel and the burn rate enhancer;    adding an amount of the phosphate stabilizer to the aqueous slurry;    preparing a dry blend of basic copper nitrate;    mixing the dry blend into the aqueous slurry; and    drying the aqueous slurry to form the stabilized gas generant composition.