Pyrotechnic gas generator compounds

Abstract

The main subject of the present invention is a solid pyrotechnic gas generator compound, the composition of which contains, expressed in weight percentages: from 60 to 70% of guanidine nitrate, from 26 to 33%, advantageously 26 to 30%, of potassium perchlorate, from 2.5 to 6% of at least one combustion modifier chosen from transition metal oxides, the precursors of such oxides and mixtures thereof, from 0 to 6% of at least one additive, and does not contain an explosive ingredient. Such a compound is particularly effective for the inflation of side airbags.

1 . A solid pyrotechnic gas generator compound, the composition of which contains:
 guanidine nitrate, and   potassium perchlorate,   
       characterized in that its composition, expressed in weight percentages, contains from:
 60 to 70% of guanidine nitrate, 
 26 to 33%, advantageously 26 to 30%, of potassium perchlorate, 
 2.5 to 6% of at least one combustion modifier chosen from transition metal oxides, the precursors of such oxides and mixtures thereof, 
 0 to 6% of at least one additive, and 
 
       does not contain an explosive ingredient. 
     
     
         2 . The compound as claimed in  claim 1 , wherein its composition consists of said guanidine nitrate, potassium perchlorate, at least one combustion modifier and optionally at least one additive. 
     
     
         3 . The compound as claimed in  claim 1 , wherein its composition is at least 94% by weight, advantageously at least 98% by weight, or even 100% by weight, made up of said guanidine nitrate, potassium perchlorate and at least one combustion modifier. 
     
     
         4 . The compound as claimed  claim 1 , wherein said at least one combustion modifier is chosen from zinc oxide (ZnO), iron oxide (Fe 2 O 3 ), chromium oxide (Cr 2 O 3 ), manganese dioxide (MnO 2 ), copper oxide (CuO), basic copper nitrate (Cu(NO 3 ) 2 .3Cu(OH) 2 ) and mixtures thereof. 
     
     
         5 . The compound as claimed in  claim 1 , wherein said at least one combustion modifier consists of copper oxide and/or basic copper nitrate. 
     
     
         6 . The compound as claimed in  claim 5 , which has a pressure exponent of less than or equal to 0.1, for a pressure of between 6 and 52 MPa. 
     
     
         7 . The compound as claimed in  claim 1 , wherein said at least one combustion modifier has a specific surface area of greater than 3 m 2 /g, advantageously greater than 10 m 2 /g and very advantageously greater than 25 m 2 /g. 
     
     
         8 . The compound as claimed in  claim 1 , wherein its composition contains silica as additive. 
     
     
         9 . The compound as claimed in  claim 8 , wherein said silica is in pulverulent form having a high specific surface area, advantageously of 100 m 2 /g or more, and of micrometric size, advantageously of nanometric size, or in the form of silica fibers of from 1 to 20 microns in diameter and from 20 to 500 microns in length. 
     
     
         10 . The compound as claimed in  claim 1 , wherein it is obtained by means of a dry process, which comprises a step of compacting a pulverulent mixture containing the constituent ingredients of said compound in powder form, optionally followed by a granulation step, itself optionally followed by a step of forming by pelletizing. 
     
     
         11 . The compound as claimed in  claim 1 , wherein it is in the form of granules, pellets or monolithic blocks. 
     
     
         12 . A pulverulent composition, which is a precursor of a compound as claimed in  claim 1 , the composition of which corresponds to that of a compound as claimed in  claim 1 . 
     
     
         13 . A gas generator, suitable for an airbag, which contains at least one compound as claimed in  claim 1 .