Copper containing igniter composition for a gas generant

Abstract

An igniter composition for a gas generant and a related method of igniting a gas generant are provided in which, in addition to a boron fuel component and an oxidizer component, the igniter composition additionally includes a gas-forming source of a condensable metal effective for transferring heat to the gas generant.

What is claimed is:  
     
         1 . An igniter composition comprising: 
 boron fuel:    an oxidizer: and    a gas-forming source of condensable copper metal effective for transferring heat to a gas generant,    wherein the gas-forming source of condensable copper metal is a copper complex that includes at least one ligand selected from the group consisting of anionic ligands, neutral alkyl ligands having at least one balancing anion, neutral ammonia ligands having at least one balancing anion, and combinations thereof.    
     
     
         2 . The igniter composition of  claim 1  wherein the copper complex comprises a copper II cation.  
     
     
         3 . The igniter composition of  claim 1  wherein the copper complex comprises at least one anionic ligand selected from the group consisting of oxalic acid, bitetrazole, aminotetrazole, guanylurea nitrate, acetic acid, tartaric acid, 5-nitrouracil, and combinations thereof.  
     
     
         4 . The igniter composition of  claim 1  wherein the copper complex comprises at least one neutral alkyl ligand selected from the group consisting of 1,2-diaminopropane, 1,3-diaminopropane, and 1,3-diaminopentane.  
     
     
         5 . The igniter composition of  claim 4  wherein at least one balancing anion comprises nitrate.  
     
     
         6 . The igniter composition of  claim 1  wherein the copper complex comprises at least one neutral ligand selected from the group consisting of diamine and ethylene diamine.  
     
     
         7 . The igniter composition of  claim 6  wherein at least one balancing anion comprises nitrate.  
     
     
         8 . The igniter composition of  claim 1  further comprising an auxiliary fuel.  
     
     
         9 . The igniter composition of  claim 1 , further comprising a binder composition.  
     
     
         10 . An igniter composition comprising: 
 about 8 to about 20 composition weight percent boron;    about 30 to about 80 composition weight percent oxidizer; and    about 10 to about 40 composition weight percent gas-forming source of condensable copper metal effective for transferring heat to a gas generant,    wherein the gas-forming source of condensable copper metal includes a copper complex having at least one ligand selected from the group consisting anionic ligands, neutral alkyl ligands having at least one balancing anion, neutral ammonia ligands having at least one balancing anion, and combinations thereof.    
     
     
         11 . The igniter composition of  claim 10  wherein the copper complex comprises a copper II cation.  
     
     
         12 . The igniter composition of  claim 10  wherein the copper complex comprises at least one anionic ligand selected from the group consisting of oxalic acid, bitetrazole, aminotetrazole, guanylurea nitrate, acetic acid, tartaric acid, 5-nitrouracil, and combinations thereof.  
     
     
         13 . The igniter composition of  claim 12  wherein the copper complex comprises copper oxalate, copper aminotetrazole, copper guanylurea nitrate, or copper tartrate.  
     
     
         14 . The igniter composition of  claim 10  wherein the copper complex includes at least one neutral alkyl ligand selected from the group consisting of 1,2-diaminopropane, 1,3-diaminopropane, and 1,3-diaminopentane.  
     
     
         15 . The igniter composition of  claim 14  wherein at least one balancing anion comprises nitrate.  
     
     
         16 . The igniter composition of  claim 10  wherein the copper complex includes at least one neutral ammonia ligand selected from the group consisting of diamine and ethylene diamine.  
     
     
         17 . The igniter composition of  claim 16  wherein at least one balancing anion is nitrate.  
     
     
         18 . The igniter composition of  claim 17  wherein the copper complex comprises copper bis-ethylenediamine dinitrate.  
     
     
         19 . The igniter composition of  claim 10  wherein the oxidizer comprises potassium nitrate.  
     
     
         20 . The igniter composition of  claim 10  further comprising up to about 25 composition weight percent auxiliary fuel.  
     
     
         21 . The igniter composition of  claim 20  wherein the auxiliary fuel comprises guanidine nitrate.  
     
     
         22 . The igniter composition of  claim 10  further comprising up to about 5 composition weight percent binder.  
     
     
         23 . A method for igniting a gas generant to inflate an airbag cushion of an inflatable restraint system of a motor vehicle comprising the steps of: 
 providing an igniter composition including boron fuel, an oxidizer and a gas-forming copper complex including at least one ligand selected from the group consisting of anionic ligands, neutral alkyl ligands having at least one balancing anion, neutral ammonia ligands having at least one balancing anion, and combinations thereof; and    igniting the igniter composition such that the gas-forming copper complex reacts with the boron fuel and the oxidizer to form a gas and condensable copper metal that conducts heat to the gas generant.    
     
     
         24 . The method of  claim 23  wherein the igniter composition comprises: 
 about 8 to about 20 composition weight percent boron fuel;  
 about 30 to about 80 composition weight percent oxidizer; and  
 about 10 to about 40 composition weight percent gas-forming copper complex.  
 
     
     
         25 . The method of  claim 24  wherein the gas-forming copper complex is selected from the group consisting of copper oxalate, copper aminotetrazole, copper guanylurea nitrate, copper tartrate, copper bis-ethylenediamine dinitrate, and combinations thereof.  
     
     
         26 . The method of  claim 24  wherein the oxidizer is potassium nitrate.  
     
     
         27 . The method of  claim 24  wherein the igniter composition further comprises up to about 25 composition weight percent auxiliary fuel.  
     
     
         28 . The method of  claim 27  wherein the auxiliary fuel comprises guanidine nitrate.  
     
     
         29 . The method of  claim 24  further comprising the step of providing a pyrotechnic squib.  
     
     
         30 . The method of  claim 29  further comprising the step of contacting the igniter composition with reaction products from the pyrotechnic squib to ignite the igniter composition.