Vehicular occupant restraint

Abstract

An igniter composition such as for a gas generant material used in pressure activated restraint system devices such as micro-gas generator applications such as seat belt pretensioners is provided. The igniter composition includes a fuel component containing at least about 3 composition weight percent and less than 15 composition weight percent of boron and an oxidizer component, wherein the fuel component and the oxidizer component are present in stoichiometrically balanced amounts. Associated methods of gas generation are also provided.

What is claimed is:  
     
         1 . An igniter composition comprising: 
 a fuel component containing at least about 3 composition weight percent and less than 15 composition weight percent of boron, and    an oxidizer component containing at least one oxidizer material selected from the group consisting of alkali metal nitrates, alkaline earth metal nitrates and mixtures thereof,    wherein the fuel component and the oxidizer component are present in stoichiometrically balanced amounts.    
     
     
         2 . The igniter composition of  claim 1  wherein: 
 the fuel component additionally contains at least one fuel material that produces gas on reaction with the at least one oxidizer material.  
 
     
     
         3 . The igniter composition of  claim 2  wherein the at least one fuel material that produces gas on reaction with the at least one oxidizer material comprises guanidine nitrate.  
     
     
         4 . The igniter composition of  claim 3  comprising less than about 60 composition weight percent guanidine nitrate.  
     
     
         5 . The igniter composition of  claim 4  comprising: 
 at least about 20 composition weight percent guanidine nitrate and no more than about 40 composition weight percent guanidine nitrate.  
 
     
     
         6 . The igniter composition of  claim 1  wherein the at least one oxidizer material is potassium nitrate.  
     
     
         7 . The igniter composition of  claim 6  wherein potassium nitrate is present in a concentration of at least about 40 composition weight percent and no more than about 85 composition weight percent.  
     
     
         8 . The igniter composition of  claim 7  wherein the fuel component additionally contains at least about 8 composition weight percent guanidine nitrate and less than about 60 composition weight percent guanidine nitrate.  
     
     
         9 . The igniter composition of  claim 8  wherein: 
 the oxidizer component contains at least about 55 composition weight percent and no more than about 75 composition weight percent of potassium nitrate and  
 the fuel component contains, 
 at least about 7 composition weight percent and less than about 10 composition weight percent of boron; and  
 at least about 20 composition weight percent and no more than about 30 composition weight percent of guanidine nitrate.  
 
 
     
     
         10 . The igniter composition of  claim 1  containing less than about 10 composition weight percent of boron.  
     
     
         11 . An occupant restraint system device comprising a housing containing a supply of reactant material, the reactant material including a fuel component containing at least about 3 composition weight percent and less than 15 composition weight percent of boron, and an oxidizer component containing at least one oxidizer material selected from the group consisting of alkali metal nitrates, alkaline earth metal nitrates and mixtures thereof, wherein the fuel component and the oxidizer component are present in stoichiometrically balanced amounts.  
     
     
         12 . The occupant restraint system device of  claim 11  wherein the housing additionally contains a supply of gas generant material and wherein upon activation of the device the reactant material reacts to produce ignition reaction products which contact at least a portion of the supply of gas generant material to initiate generation of gas thereby.  
     
     
         13 . The occupant restraint system device of  claim 12  wherein the supply of reactant material comprises at least about 20% on a weight basis of the supply of reactant material and the supply of gas generant material combined.  
     
     
         14 . A seat belt pretensioner comprising the occupant restraint system device of  claim 12 .  
     
     
         15 . A micro-gas generator comprising the occupant restraint system device of  claim 12 .  
     
     
         16 . The occupant restraint system device of  claim 11  wherein the reactant material fuel component contains less than about 10 composition weight percent of boron.  
     
     
         17 . The occupant restraint system device of  claim 11  wherein the reactant material fuel component additionally contains at least one fuel material that produces gas on reaction with the at least one oxidizer material.  
     
     
         18 . The occupant restraint system device of  claim 17  wherein the at least one fuel material that produces gas on reaction with the at least one oxidizer material comprises guanidine nitrate.  
     
     
         19 . The occupant restraint system device of  claim 18  wherein the reactant material comprises less than about 60 composition weight percent guanidine nitrate.  
     
     
         20 . The occupant restraint system device of  claim 19  wherein the reactant material comprises: 
 at least about 20 composition weight percent guanidine nitrate and no more than about 40 composition weight percent guanidine nitrate.  
 
     
     
         21 . The occupant restraint system device of  claim 11  wherein the at least one oxidizer material is potassium nitrate.  
     
     
         22 . The occupant restraint system device of  claim 21  wherein potassium nitrate is present in the reactant material in a concentration of at least about 40 composition weight percent and no more than about 85 composition weight percent.  
     
     
         23 . The occupant restraint system device of  claim 22  wherein the fuel component additionally contains at least about 8 composition weight percent guanidine nitrate and less than about 60 composition weight percent guanidine nitrate.  
     
     
         24 . The occupant restraint system device of  claim 23  wherein: 
 the reactant material oxidizer component contains at least about 55 composition weight percent and no more than about 75 composition weight percent of potassium nitrate and  
 the reactant material fuel component contains,  
 at least about 7 composition weight percent and less than about 10 composition weight percent of boron; and  
 at least about 20 composition weight percent and no more than about 30 composition weight percent of guanidine nitrate.  
 
     
     
         25 . A method of generating gas suitable for use in an occupant restraint system of a motor vehicle, said method comprising: 
 igniting a supply of an igniter composition containing a fuel component containing at least about 3 composition weight percent and less than 15 composition weight percent of boron, and an oxidizer component containing at least one oxidizer material selected from the group consisting of alkali metal nitrates, alkaline earth metal nitrates and mixtures thereof, wherein the fuel component and the oxidizer component are present in stoichiometrically balanced amounts, to form igniter composition reaction products and    contacting a supply of a gas generant composition with the igniter composition reaction products to form product gas.    
     
     
         26 . The method of  claim 25  wherein the igniter composition is present in a relative amount of at least about 20% of the supply of the igniter composition and the supply of the reactant material, on a weight basis.