Enhanced slag formation for copper-containing gas generants

Abstract

Gas generants comprising copper are provided that have improved slagging ability. In certain aspects, the gas generants include a fuel, an oxidizer comprising basic copper nitrate, and a large particle size endothermic slag-forming component, such as aluminum hydroxide (Al(OH) 3 ). The gas generants may be cool burning, e.g., having a maximum flame temperature at combustion (T c )≦about 1,900K (1,627° C.). The disclosure also provides methods of enhancing slag formation for a gas generant composition that comprises copper. Such methods enhance slag formation during combustion of the gas generant composition by at least 50%.

What is claimed is: 
     
         1 . A gas generant composition comprising:
 a fuel;   an oxidizer comprising basic copper nitrate; and   an endothermic slag-forming component having an average particle size diameter of greater than or equal to about 150 μm, wherein the gas generant composition has a maximum flame temperature at combustion (T c ) of less than or equal to about 1,900K (1,627° C.).   
     
     
         2 . The gas generant composition of  claim 1 , wherein the endothermic slag-forming component has a decomposition temperature in a range of greater than or equal to about 180° C. to less than or equal to about 450° C. 
     
     
         3 . The gas generant composition of  claim 1 , wherein the endothermic slag-forming component is present at greater than or equal to about 5% by weight to less than or equal to about 20% by weight of the total gas generant composition. 
     
     
         4 . The gas generant composition of  claim 1 , wherein the endothermic slag-forming component is selected from the group consisting of: aluminum hydroxide, hydromagnesite, Dawsonite, magnesium hydroxide, magnesium carbonate subhydrate, Bohemite, calcium hydroxide, and combinations thereof. 
     
     
         5 . The gas generant composition of  claim 1 , wherein the fuel is selected from the group consisting of: guanidine nitrate, copper bis guanylurea dinitrate, hexamine cobalt (III) nitrate, copper diammine bitetrazole, and combinations thereof. 
     
     
         6 . The gas generant composition of  claim 1 , wherein the oxidizer comprising basic copper nitrate is present at greater than or equal to about 30% to less than or equal to about 70% by weight of the gas generant composition. 
     
     
         7 . The gas generant composition of  claim 1 , wherein the endothermic slag-forming component has an average particle size diameter of greater than or equal to about 200 μm. 
     
     
         8 . The gas generant composition of  claim 1 , wherein the fuel is present at greater than or equal to about 25% to less than or equal to about 70% by weight of the total gas generant composition; the oxidizer is present at greater than or equal to about 25% to less than or equal to about 75% by weight of the total gas generant composition; the endothermic slag-forming component is present at greater than or equal to about 5% to less than or equal to about 20% by weight of the total gas generant composition; and greater than or equal to 0% to less than or equal to about 4% of one or more gas generant additives selected from the group consisting of: flow aids, press aids, metal oxides, and combinations thereof. 
     
     
         9 . The gas generant composition of  claim 8 , further comprising a co-oxidizer comprising a perchlorate-based compound present at greater than 0% to less than or equal to about 3% by weight of the total gas generant composition. 
     
     
         10 . A gas generant composition comprising:
 a fuel;   at least one oxidizer comprising basic copper nitrate; and   an endothermic slag-forming component comprising aluminum hydroxide having an average particle size diameter of greater than or equal to about 150 μm, wherein the gas generant composition has a maximum flame temperature at combustion (T c ) of less than or equal to about 1,900K (1,627° C.).   
     
     
         11 . The gas generant composition of  claim 10 , wherein the maximum flame temperature at combustion (T c ) is greater than or equal to about 1,350K (1,077° C.) to less than or equal to about 1,450K (1,177° C.). 
     
     
         12 . The gas generant composition of  claim 10 , wherein the endothermic slag-forming component comprising aluminum hydroxide is present at greater than or equal to about 5% by weight to less than or equal to about 20% by weight of the total gas generant composition. 
     
     
         13 . The gas generant composition of  claim 10 , wherein the fuel is selected from the group consisting of: guanidine nitrate, copper bis guanylurea dinitrate, hexamine cobalt (III) nitrate, copper diammine bitetrazole, and combinations thereof. 
     
     
         14 . The gas generant composition of  claim 10 , wherein the endothermic slag-forming component comprising aluminum hydroxide has an average particle size diameter of greater than or equal to about 200 μm. 
     
     
         15 . The gas generant composition of  claim 10 , wherein the fuel is present at greater than or equal to about 25% to less than or equal to about 70% by weight of the total gas generant composition; the oxidizer is present at greater than or equal to about 25% to less than or equal to about 75% by weight of the total gas generant composition; the endothermic slag-forming component is present at greater than or equal to about 5% to less than or equal to about 20% by weight of the total gas generant composition; and greater than or equal to 0% to less than or equal to about 4% of one or more gas generant additives selected from the group consisting of: flow aids, press aids, metal oxides, and combinations thereof. 
     
     
         16 . The gas generant composition of  claim 15 , further comprising a co-oxidizer comprising a perchlorate-based compound present at greater than 0% to less than or equal to about 3% by weight of the total gas generant composition. 
     
     
         17 . A method of enhancing slag formation for a gas generant composition, the method comprising:
 introducing an endothermic slag-forming component having an average particle size diameter of greater than or equal to about 150 μm to a gas generant composition comprising a fuel and an oxidizer comprising basic copper nitrate, wherein the introducing of the endothermic slag-forming component enhances slag formation during combustion of the gas generant composition by at least 50%.   
     
     
         18 . The method of  claim 17 , wherein the gas generant composition has a maximum flame temperature at combustion (T c ) of less than or equal to about 1,900K (1,627° C.), the fuel is selected from the group consisting of: guanidine nitrate, copper bis guanylurea dinitrate, hexamine cobalt (III) nitrate, copper diammine bitetrazole, and combinations thereof, and the endothermic slag-forming component is selected from the group consisting of: aluminum hydroxide, hydromagnesite, Dawsonite, magnesium hydroxide, magnesium carbonate subhydrate, Bohemite, calcium hydroxide, and combinations thereof. 
     
     
         19 . The method of  claim 17 , wherein the endothermic slag-forming component enhancing slag formation comprises aluminum hydroxide and is present at greater than or equal to about 5% by weight to less than or equal to about 20% by weight of the total gas generant composition. 
     
     
         20 . The method of  claim 17 , wherein the introducing of the endothermic slag-forming component enhances slag formation during combustion of the gas generant composition by at least 60%.