Extrudable gas generant

Abstract

Extrudable gas generant compositions which, upon combustion, produce or result in an improved effluent and related methods for generating inflation gas for use in an inflatable restraint system are provided. Such extrudable gas generant compositions include a non-azide, organic, nitrogen-containing fuel, at least one copper-containing compound, a perchlorate additive and a polymeric binder material. The at least one copper-containing compound may be selected from basic copper nitrate, cupric oxide, a copper diammine-ammonium-nitrate mixture wherein the ammonium nitrate is present in the mixture in a range of about 3 to about 90 weight percent, and/or a copper-nitrate complex resulting from reaction of 5-aminotetrazole with basic copper nitrate. The perchlorate additive is present in an amount effective to result in a gaseous effluent, when the gas generant composition is combusted, having a reduced content of at least one species selected from carbon monoxide, ammonia, nitrogen dioxide and nitric oxide, as compared to a same gas generant free from the perchlorate additive. The polymeric binder material is effective to render the gas generant composition extrudable.

1 . A method for generating an inflation gas for inflating an airbag cushion of an inflatable restraint system of a motor vehicle, the method comprising:
 igniting an extrudable gas generant composition comprising:
 at least one non-azide, organic, nitrogen-containing fuel; 
 at least one copper-containing compound selected from the group consisting of basic copper nitrate, cupric oxide, a copper diammine dinitrate-ammonium nitrate mixture wherein ammonium nitrate is present in the mixture in a range of about 3 to about 90 weight percent, copper diammine bitetrazole, a copper-nitrate complex resulting from reaction of 5-aminotetrazole with basic copper nitrate, and combinations thereof; 
 sufficient ammonium perchlorate to result in the gas generant composition, when combusted, having an increased burn rate and a gaseous effluent having a reduced content of at least one species selected from the group consisting of carbon monoxide, ammonia, nitrogen dioxide and nitric oxide, as compared to a same gas generant composition free of the ammonium perchlorate; and 
 a polymeric binder material effective to render the gas generant composition extrudable; and 
   inflating the airbag cushion with the inflation gas.   
   
   
       2 . The method of  claim 1  wherein the ammonium perchlorate is present in the extrudable gas generant composition in a relative amount of 1 to 10 composition weight percent. 
   
   
       3 . The method of  claim 1 , wherein upon combustion, copper (II) chloride is a principle chlorine-containing species found in the gaseous effluent. 
   
   
       4 . The method of  claim 1  wherein the at least one non-azide, organic, nitrogen-containing fuel comprises guanidine nitrate present in a relative amount of 5 to 30 composition weight percent. 
   
   
       5 . The method of  claim 1  wherein the at least one non-azide, organic, nitrogen-containing fuel present in the extrudable gas generant composition is guanidine nitrate present in a relative amount of 5 to 20 composition weight percent. 
   
   
       6 . The method of  claim 1  wherein at least one copper-containing compound present in the extrudable gas generant composition is a copper diammine dinitrate-ammonium nitrate mixture wherein ammonium nitrate is present in the mixture in a range of about 3 to about 90 weight percent 
   
   
       7 . The method of  claim 1  wherein the at least one copper-containing compound present in the extrudable gas generant composition comprises basic copper nitrate. 
   
   
       8 . The method of  claim 1  wherein at least one copper-containing compound present in the extrudable gas generant composition is a copper-nitrate complex resulting from reaction of 5-aminotetrazole with basic copper nitrate. 
   
   
       9 . The method of  claim 8  wherein the copper-nitrate complex resulting from reaction of 5-aminotetrazole with basic copper nitrate is present in the gas generant composition in a relative amount of 30 to 60 composition weight percent. 
   
   
       10 . The method of  claim 1  wherein the extrudable gas generant composition includes a combination of basic copper nitrate and a copper-nitrate complex resulting from reaction of 5-aminotetrazole with basic copper nitrate present in a relative amount of 50 to about 80 composition weight percent. 
   
   
       11 . The method of  claim 10  wherein the combination of basic copper nitrate and the copper-nitrate complex includes about 20 to about 40 weight percent basic copper nitrate based on the total weight of the combination and about 60 to about 80 weight percent of the copper-nitrate complex based on total weight of the combination. 
   
   
       12 . The method of  claim 1  wherein the ammonium perchlorate is present in a particle size sufficient to result in the extrudable gas generant composition having increased heterogeneity and effectiveness to inhibit the generation of undesirable species in the gaseous effluent. 
   
   
       13 . The method of  claim 12  wherein the ammonium perchlorate has a mean particle size in excess of 100 microns and is present in a relative amount of 1 to 10 composition weight percent. 
   
   
       14 . The method of  claim 13  wherein the ammonium perchlorate has a mean particle size in excess of 200 microns. 
   
   
       15 . The method of  claim 1  wherein the extrudable gas generant composition additionally comprises a perchlorate additive combustion enhancer selected from the group consisting of iron oxide, copper chromite, ferricyanide/ferrocyanide pigments, and combinations thereof. 
   
   
       16 . The method of  claim 1  wherein the inclusion of ammonium perchlorate results in the gas generant composition, when combusted, having a reduced content of at least carbon monoxide without a countervailing increase countervailing increase in levels of undesirable oxides of nitrogen selected from the group consisting of nitric oxide, nitrogen dioxide and combination thereof. 
   
   
       17 . A method for generating an inflation gas for inflating an airbag cushion of an inflatable restraint system of a motor vehicle, the method comprising:
 igniting an extrudable gas generant composition comprising:
 at least one non-azide, organic, nitrogen-containing fuel present in a relative amount of 5 to 60 composition weight percent; 
 at least one copper-containing compound selected from the group consisting of basic copper nitrate, cupric oxide, copper diammine dinitrate-ammonium nitrate mixture wherein ammonium nitrate is present in the mixture in a range of about 3 to about 90 weight percent, copper diammine bitetrazole, a copper-nitrate complex resulting from reaction of 5-aminotetrazole with basic copper nitrate, and combinations thereof, the at least one copper-containing compound present in a relative amount of 10 to 80 composition weight percent; 
 ammonium perchlorate present in a relative amount of 1 to 10 composition weight percent and having a mean particle size in excess of 100 microns sufficient to result in the extrudable gas generant composition having increased heterogeneity to result in a gaseous effluent, when the gas generant composition is combusted, having a reduced content of at least one species selected from the group consisting of carbon monoxide, ammonia, nitrogen dioxide and nitric oxide, as compared to a same gas generant composition free of the ammonium perchlorate; and 
 a polymeric binder material present in a relative amount of 1 to 20 composition weight percent to render the gas generant composition extrudable, the polymeric binder material selected from the group of cellulosic materials, natural gums, polyacrylates, polyacrylamides, polyurethanes, polybutadienes, polystyrenes, polyvinyl alcohols, polyvinyl acetates, silicones and combinations of two or more thereof; and 
   inflating the airbag cushion with the inflation gas.   
   
   
       18 . A method for generating an inflation gas for inflating an airbag cushion of an inflatable restraint system of a motor vehicle, the method comprising:
 igniting an extrudable gas generant composition comprising:
 5 to 30 composition weight percent guanidine nitrate; 
 10 to 80 composition weight percent of a combination of at least one copper-containing compound selected from the group consisting of basic copper nitrate, cupric oxide, a copper diammine dinitrate-ammonium nitrate mixture wherein the ammonium nitrate is present in the mixture in a range of about 3 to about 90 weight percent, copper diammine bitetrazole, a copper-nitrate complex resulting from reaction of 5-aminotetrazole with basic copper nitrate, and combinations thereof; 
 1 to 10 composition weight percent of ammonium perchlorate having a mean particle size in excess of 200 microns sufficient to result in the extrudable gas generant composition having increased heterogeneity to inhibit the generation of undesirable species in the gaseous effluent; and 
 1 to 20 composition weight percent of polymeric binder material effective to render the gas generant composition extrudable, wherein the polymeric binder material is selected from the group consisting of cellulosic materials, natural gums, polyacrylates, polyacrylamides, polyurethanes, polybutadienes, polystyrenes, polyvinyl alcohols, polyvinyl acetates, silicones and combinations of two or more thereof; and 
   inflating the airbag cushion with the inflation gas.