Gas generator fuel composition

Abstract

The invention relates to solid gas generator fuel compositions (gas producing mixtures), comprising: (A) nitroguanidine or nitroguanidine stabilised with 0.1 to 0.5% nitroguanidinium hydrogen sulphate and nitroguanidinium nitrate as fuel; (B) an oxidising agent selected from the group comprising alkali and earth alkali nitrates, chlorates and perchlorates, ammonium nitrate and perchlorate, copper compounds with oxidising properties and mixtures thereof; (C) a stabiliser selected from the group comprising hydrophobic SiO 2 , inorganic and organic acids and mixtures thereof; and optionally (D) a combustion stabiliser or moderator and ash former or trap and mixtures thereof. The above gas generator fuel compositions comprise an improved shelf-life under hot storage conditions at 110° C.

1 . Propellant for gas generators, comprising 
 (A) nitroguanidine as a fuel, stabilized with 0.1 to 0.5 percent by weight nitroguanidinium hydrogen sulfate and nitroguanidinium nitrate,    (B) an oxidizing agent selected from the group consisting of alkali metal and alkaline earth metal nitrates, -chlorates and -perchlorates, ammonium nitrate and -perchlorate, oxidizing copper compounds and mixtures thereof,    (C) a stabilizer selected from the group consisting of inorganic and organic acids and mixtures thereof, optionally    (D) a burn-up stabilizer or moderator, respectively, and slag former or slag trap, respectively, and mixtures thereof.    
     
     
         2 . Propellant for gas generators, comprising 
 (A) nitroguanidine as a fuel,    (B) an oxidizing agent selected from the group consisting of alkali metal and alkaline earth metal nitrates, -chlorates and -perchlorates, ammonium nitrate and -perchlorate, oxidizing copper compounds and mixtures thereof,    (C) boric acid as a stabilizer, optionally    (D) a burn-up stabilizer or moderator, respectively, and slag former or slag trap, respectively, and mixtures thereof.    
     
     
         3 . Propellant for gas generators according to  claim 1  or  2 , wherein component (A) is present in an amount of about 33 to about 60 percent by weight, preferably of about 40 to about 60 percent by weight and particular of about 45 to about 55 percent by weight, component (B) is present in an amount of about 35 to about 55 percent by weight, preferably of about 38 to about 52 percent by weight and in particular of about 40 to about 48 percent by weight, component (C) is present in an amount of up to about 5 percent by weight, preferably of up to about 3 percent by weight, more preferably of up to about 1.6 percent by weight and in particular of about 0.5 to 1.6 percent by weight and component (D) is present in an amount of up to about 7 percent by weight, preferably of up to about 5 percent by weight and in particular of about 0.4 to about 5 percent by weight.  
     
     
         4 . Propellant for gas generators according to any one of  claims 1  to  3 , wherein component (C) additionally comprises hydrophobic SiO 2  as a stabilizer.  
     
     
         5 . Propellant for gas generators according to any one of  claims 1  to  4 , wherein component (B) is selected from the group consisting of sodium nitrate, potassium nitrate, strontium nitrate, ammonium perchlorate, potassium chlorate, copper(II)trihydroxynitrate and mixtures thereof.  
     
     
         6 . Propellant for gas generators according to any one of  claims 1  to  5 , wherein component (B) is a mixture of potassium nitrate and ammonium perchlorate.  
     
     
         7 . Propellant for gas generators according to any one of claims  1  and  3  to  6 , wherein component (C) is selected from the group consisting of boric acid, citric acid, tartaric acid, cyanuric acid, terepthalic acid and fumaric acid.  
     
     
         8 . Propellant for gas generators according to any one of  claims 1  to  7 , wherein as component (C) an inorganic or organic acid is present besides hydrophobic SiO 2  as stabilizer.  
     
     
         9 . Propellant for gas generators according to any one of  claims 1  to  8 , wherein component (D) is selected from the group consisting of Al 2 O 3 , Fe 2 O 3 , SiO 2 , iron acetylacetonate, mixtures thereof and mixtures of highly dispersed Al 2 O 3  with highly dispersed SiO 2 .  
     
     
         10 . Propellant for gas generators according to  claim 9 , wherein Al 2 O 3  is highly dispersed Al 2 O 3 .  
     
     
         11 . Propellant for gas generators according to  claim 9 , wherein component (D) is a mixture of about 16 percent by weight highly dispersed Al 2 O 3  and about 84 percent by weight highly dispered SiO 2 .  
     
     
         12 . Propellant for gas generators according to any one of  claims 1  to  11  further comprising as component (E) at least one binder.  
     
     
         13 . Propellant for gas generators according to  claim 12 , wherein component (E) is selected from cellulose compounds, polymers of one or more polymerizable olefinic unsaturated monomers, a metal salt of stearic acid being insoluble in water at room temperature and graphite.  
     
     
         14 . Propellant for gas generators according to  claim 12  or  13 , wherein component (E) is present in amount of up to about 5 percent by weight, preferably of up to about 3 percent by weight, more preferably of up to about 1 percent by weight and in particular of about 0.2 to about 0.5 percent by weight.  
     
     
         15 . Propellant for gas generators according to any one of  claims 1  to  14 , comprising 
 (A) nitroguanidine stabilized with 0.1 to 0.5 percent by weight nitroguanidinium hydrogen sulfate and nitroguanidinium nitrate as a fuel,  
 (B) KNO 3  or a mixture of KNO 3  and NH 4 ClO 4  as oxidizing agent,  
 (C) a stabilizer selected from the group consisting of hydrophobic SiO 2 , boric acid, citric acid, tartaric acid, cyanuric acid, terephthalic acid, fumaric acid and mixtures thereof,  
 (D) highly dispersed Al 2 O 3 , optionally as a mixture with Fe 2 O 3  and  
 (E) graphite.  
 
     
     
         16 . Propellant for gas generators comprising 
 (A) nitroguanidine stabilized with 0.1 to 0.5% nitroguanidinium hydrogen sulfate and nitroguaninidinium nitrate as a fuel,    (B) Sr(NO 3 ) 2  or a mixture of KNO 3  or NaNO 3  with NH 4 ClO 4  as oxidizing agent, an optionally    (D) at least one burn-up stabilizer/moderator and slag former/slag trap.    
     
     
         17 . Propellant for gas generators according to  claim 16 , wherein component (D) is selected from the group consisting of Al 2 O 3 , highly dispersed Al 2 O 3 , Fe 2 O 3 , SiO 2 , iron acetyl acetonate, mixtures thereof and a mixture of highly dispersed Al 2 O 3  with highly dispersed SiO 2 .  
     
     
         18 . Propellant for gas generators according to  claim 16  or  17 , wherein component (A) is present in an amount of about 33 to about 60 percent by weight, preferably of about 40 to about 60 percent by weight and in particular of about 45 to about 55 percent by weight, component (B) is present in an amount of about 35 to about 55 percent by weight, preferably of about 38 to about 52 percent by weight and in particular of about 40 to about 48 percent by weight and component (D) is present in an amount of up to about 7 percent by weight, preferably of about 5 percent by weight and in particular of about 0.4 to about 5 percent by weight.  
     
     
         19 . Propellant for gas generators according to any one of  claims 16  to  18 , further comprising as component (E) at least one binder.  
     
     
         20 . Propellant for gas generators according to  claim 19 , wherein the binder is selected from the group consisting of cellulose compounds, polymers of one or more polymerizable olefinic unsaturated monomers, a metal salt of stearic acid being insoluble in water at room temperature and graphite.  
     
     
         21 . Use of a propellant for gas generators according to any one of  claims 1  to  20  as gas generating agent in airbags, as extinguishing agent or as propellant.