Gas generant and manufacturing method thereof

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. A novel method of forming the compositions is also presented wherein the various constituents are wetted and/or dissolved, and then cured within the polyvinylazole matrix thereby forming a more intimate combination within the gas generant composition. A vehicle occupant protection system 180, and other gas generating systems, incorporate the compositions of the present invention.

1 . A method of forming a gas generating composition comprising the steps of: 
 providing a solvent effective to dissolve a fuel comprising a polymeric azole selected from the group consisting of vinyl tetrazoles, vinyl triazoles and vinyl furazans, 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;    adding the fuel to the mixing vessel;    adding an oxidizer to the mixing vessel;    stirring the mixture;    adding an initiator to the mixing vessel to initiate polymerization of the slurry; and    curing the mixture.    
   
   
       2 . The method of  claim 1  further comprising the step of adding an additive to the mixing vessel prior to adding the initiator.  
   
   
       3 . The method of  claim 1  further comprising the step of heating the mixing vessel below boiling.  
   
   
       4 . The method of  claim 1  wherein adding the solvent and adding the fuel to the mixing vessel comprises the same step whereby the fuel also functions as the solvent.  
   
   
       5 . A gas generating system containing a gas generant produced by the method of  claim 1 .  
   
   
       6 . A gas generating system containing a gas generant formed by the method comprising the steps of: 
 providing a solvent effective to dissolve a fuel comprising a polymeric azole selected from the group consisting of vinyl tetrazoles, vinyl triazoles and vinyl furazans, 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;    adding the fuel to the mixing vessel;    adding an oxidizer to the mixing vessel;    stirring the mixture;    adding an initiator to the mixing vessel to initiate polymerization of the slurry; and    curing the mixture.    
   
   
       7 . The gas generating system of  claim 6  wherein said system is a vehicle occupant protection system.  
   
   
       8 . The gas generating system of  claim 6  wherein said system is an airbag system.  
   
   
       9 . The gas generating system of  claim 6  wherein said system is a seatbelt assembly system.  
   
   
       10 . The gas generating system of  claim 6  wherein said system activates an inflatable floatable device.  
   
   
       11 . The gas generating system of  claim 6  wherein said system is a fire extinguishing system.