Gas generant compositions

Abstract

The present invention generally relates to gas generant compositions for inflators of occupant restraint systems, for example. An extrudable pyrotechnic composition includes polyvinylazoles for use within an airbag gas generator. The fuel may be selected from exemplary polyvinylazoles including 5-amino-1-vinyltetrazole, poly(5-vinyltetrazole), poly(2-methyl-5-vinyl)tetrazole, poly(1-vinyl)tetrazole, poly(3-vinyl)1,2,5 oxadiazole, and poly(3-vinyl)1,2,4-triazole. An oxidizer is combined with the fuel and preferably contains phase stabilized ammonium nitrate.

1 . A gas generating system comprising a composition, the composition comprising: 
 an aromatic fuel component consisting of one or more aromatic fuels, said fuel comprising a member of the group consisting of polyvinyltetrazoles, polyvinyltriazoles, and polyvinyidiazoles; and    an oxidizer,    wherein said polymeric azole comprises about 5-40%, and said oxidizer comprises about 60-95%, said percentages stated by weight of said composition, and said composition extrudable upon combination of said fuel and said oxidizer.    
   
   
       2 . The gas generating system of  claim 1  wherein said composition further comprises: 
 a secondary fuel selected from the group consisting of 5,5′-Bis-1H-tetrazole (BHT.1GAD), diguanidinium salt of 5,5′-Bis-1H-tetrazole (BHT.2GAD), monoaminoguanidinium salt of 5,5′-Bis-1H-tetrazole (BHT.1AGAD), diaminoguanidinium salt of 5,5′-Bis-1H-tetrazole (BHT.2AGAD), monohydrazinium salt of 5,5′-Bis-1H-tetrazole (BHT.1HH), dihydrazinium salt of 5,5′-Bis-1H-tetrazole (BHT.2HH), monoammonium salt of 5,5′-bis-1H-tetrazole (BHT.1NH 3 ), diammonium salt of 5,5′-bis-1H-tetrazole (BHT.2NH 3 ), mono-3-amino-1,2,4-triazolium salt of 5,5′-bis-1H-tetrazole (BHT.1ATAZ), di-3-amino-1,2,4-triazolium salt of 5,5′-bis-1H-tetrazole (BHT.2ATAZ), and diguanidinium salt of 5,5′-Azobis-1H-tetrazole (ABHT.2GAD), monoammonium salt of 3-nitro-1,2,4-triazole (NTA.1NH 3 ), monoguanidinium salt of 3-nitro-1,2,4-triazole (NTA.1GAD), diammonium salt of dinitrobitriazole (DNBTR.2NH 3 ), diguanidinium salt of dinitrobitriazole (DNBTR.2GAD), and monoammonium salt of 3,5-dinitro-1,2,4-triazole (DNTR.1NH 3 ).    
   
   
       3 . A gas generating system comprising a composition, the composition comprising: 
 a fuel component comprising a member of the group consisting of polyvinyltetrazoles, polyvinyltriazoles, and polyvinyidiazoles; and    phase stabilized ammonium nitrate,    wherein said polymeric azole comprises about 5-40%, and said phase stabilized ammonium nitrate comprises about 60-95%, said percentages stated by weight of said composition.    
   
   
       4 . The gas generating system of  claim 1  wherein said oxidizer is selected from the group consisting of transitional metal nitrates, alkali metal nitrates, alkaline earth metal nitrates, and combinations thereof.  
   
   
       5 . The gas generating system of  claim 1  wherein said fuel is selected from the group consisting of 5-amino-1-vinyltetrazole, poly(5-vinyltetrazole), poly(2-methyl-5-vinyl) tetrazole, poly(1-vinyl) tetrazole, poly(3-vinyl)1,2,5 oxadiazole, and poly(3-vinyl)1,2,4-triazole.  
   
   
       6 . The gas generating system of  claim 1  wherein said oxidizer is selected from the group consisting of metal and nonmetal nitrates, perchlorates, and chlorates, and metal and nonmetal organic and inorganic oxides, and combinations thereof.  
   
   
       7 . The gas generating system of  claim 1  wherein said composition comprises: 
 a fuel selected from the group consisting of poly(2-methyl-5-vinyl)tetrazole, 5-amino-1-vinyltetrazole, poly(5-vinyltetrazole), poly(1-vinyl)tetrazole, poly(3-vinyl)1,2,5-oxadiazole, and poly(3-vinyl)1,2,4-triazole, and mixtures thereof; and    an oxidizer selected from the group consisting of strontium nitrate, potassium nitrate, and phase stabilized ammonium nitrate.    
   
   
       8 . The gas generating system of  claim 1  wherein said composition comprises 5-amino-1-vinyltetrazole and phase stabilized ammonium nitrate.  
   
   
       9 . The gas generating system of  claim 1  wherein said composition comprises poly(2-methyl-5-vinyl) tetrazole and phase stabilized ammonium nitrate.  
   
   
       10 . The gas generating system of  claim 1  wherein said composition comprises poly(5-vinyltetrazole) and phase stabilized ammonium nitrate.  
   
   
       11 . The gas generating system of  claim 1  wherein said composition comprises poly(1-vinyl) tetrazole and phase stabilized ammonium nitrate.  
   
   
       12 . The gas generating system of  claim 1  wherein said composition comprises poly(3-vinyl)1,2,5 oxadiazole and phase stabilized ammonium nitrate.  
   
   
       13 . The gas generating system of  claim 1  wherein said composition comprises poly(3-vinyl)1,2,5 triazole and phase stabilized ammonium nitrate.  
   
   
       14 . A method of forming a gas generating composition comprising a polymeric azole fuel and an oxidizer, the method comprising the steps of: 
 providing a solvent effective to dissolve a fuel comprising a polymeric azole selected from the group consisting of polyvinyltetrazoles, polyvinyltriazoles and polyvinylfurazans, the solvent selected with regard to the solvability of the functional group(s) that may be present on the polymeric azole, the solvent placed in a mixing vessel;    heating the solvent below boiling and below the autoignition temperature of any constituents to be added to the vessel;    adding the fuel to the solvent and dissolving the same while stirring the mixture;    adding the oxidizer to the solvent and dissolving the same while stirring the mixture;    at least partly cooking off the solvent by maintaining a steady heat and stirring of the slurry; and    coprecipitating a homogenous solution containing the fuel and the oxidizer.    
   
   
       15 . A gas generating system containing a gas generant produced by the method of  claim 14.