Gas generator containing a flash suppressant

Abstract

Flame suppressants or catalysts, independent of the gas generant composition, reduce the flame front and carbon monoxide produced by combustion of gas generating compositions employed within gas generating systems such as vehicle occupant restraint systems, for example. Heterogeneous distribution of the flash suppressant and the gas generant within the gas generant bed facilitates, upon gas generator activation, a reduction in flame front of any known gas generant without reformulating the gas generating composition.

1 . A gas generating system comprising:
 a gas generator for generating gas;   a propellant chamber within said gas generator;   a gas generating composition within said propellant chamber combustible to produce gas and a flame front; and   a flame suppressant distributed about said gas generating composition within said propellant chamber in heterogeneous, separate, and distinct relationship to said gas generating composition;   wherein said gas generating composition and said flame suppressant each define a first and a second solid phase, respectively, said first and second solid phases distinct from each other wherein the flame suppressant and the gas generating composition are not combined into one composition.   
     
     
         2 . The gas generating system of  claim 1  wherein said gas generating composition comprises nitrocellulose. 
     
     
         3 . The gas generating system of  claim 1  comprising a pretensioner. 
     
     
         4 . The gas generating system of  claim 1  comprising an airbag inflator. 
     
     
         5 . The gas generating system of  claim 1  wherein said gas generating system is a vehicle occupant protection system. 
     
     
         6 . The gas generating system of  claim 1  wherein said flame suppressant is selected from at least one member of the group selected from transition metals, transition metal oxides, and mixtures thereof. 
     
     
         7 . The gas generating system of  claim 1  wherein said flame suppressant comprises about 2 to 35% by weight and said gas generating composition comprises about 65 to 98% by weight, said weight percents based on the combined weight of the gas generating composition and the flame suppressant. 
     
     
         8 . The gas generating system of  claim 1  wherein said flame suppressant is selected from the group consisting of transitional metals including copper, iron, cerium, platinum, vanadium, zinc, zirconium, barium, lanthanum, manganese, nickel, molybdenum, rhodium, and palladium; transitional metal oxides selected from the group of oxides formed with metals selected from the group consisting of copper, iron, cerium, platinum, vanadium, zinc, zirconium, barium, lanthanum, manganese, nickel, molybdenum, rhodium, and palladium; an alkali metal such as sodium or potassium and a mixture containing two or more constituents selected from one or more of the groups including transitional metals, oxides of transitional metals, and alkali metals. 
     
     
         9 . A gas generating system comprising:
 a gas generator for generating gas;   a propellant chamber within said gas generator;   a gas generating composition comprising nitrocellulose, said gas generant contained within said propellant chamber and said gas generant combustible to produce gas; and   a flame suppressant distributed about said gas generating composition within said propellant chamber, said flame suppressant selected from one or more of the group consisting of transitional metals, transitional metal oxides, and mixtures thereof;   wherein said gas generating composition and said flame suppressant each define a first and a second solid phase, respectively, said first and second solid phases distinct from each other wherein the flame suppressant and the gas generant are not combined into one composition, and, said flame suppressant reduces the flame front otherwise produced by the gas generator in the absence of said flame suppressant.   
     
     
         10 . The gas generating system of  claim 9  wherein said flame suppressant is selected from the group consisting of transitional metals including copper, iron, cerium, platinum, vanadium, zinc, zirconium, barium, lanthanum, manganese, nickel, molybdenum, rhodium, and palladium; transitional metal oxides selected from the group of oxides formed with metals selected from the group consisting of copper, iron, cerium, platinum, vanadium, zinc, zirconium, barium, lanthanum, manganese, nickel, molybdenum, rhodium, and palladium; an alkali metal selected from the group consisting of sodium or potassium; and a mixture containing two or more constituents selected from one or more of the groups selected from the group consisting of transitional metals, oxides of transitional metals, and alkali metals. 
     
     
         11 . The gas generating system of  claim 9  wherein said flame suppressant comprises about 2 to 35% by weight and said gas generating composition comprises about 65 to 98% by weight, said weight percents based on the combined weight of the gas generating composition and said flame suppressant. 
     
     
         12 . A gas generating system comprising:
 a gas generator for generating gas;   a propellant chamber within said gas generator;   a gas generating composition within said propellant chamber combustible to produce gas and a flame front; and   a flame suppressant distributed about said gas generating composition within said propellant chamber in juxtaposed, separate, and heterogeneous relationship to said gas generating composition;   wherein said gas generating composition and said flame suppressant each define a first and a second solid phase, respectively, said first and second solid phases distinct from each other wherein the flame suppressant and the gas generating composition are not combined into one homogeneous composition.   
     
     
         13 . The gas generating system of  claim 12  wherein said gas generating composition is provided in a tablet or extruded form, and that said flame suppressant is distributed about the tablets within said propellant chamber. 
     
     
         14 . The gas generating system of  claim 12  wherein said flame suppressant is a molybdenum dioxide/copper oxide catalyst.