Method for inflating a gas bag and gas bag module for use in this method

Abstract

A method for inflating a gas bag of a safety arrangement in vehicles provides a gas generator which contains a pyrotechnic propellant comprising an organic fuel and ammonium perchlorate as an oxidizing agent. The pyrotechnic propellant, after its activation, releases a gas which has an amount of hydrochloric acid. A coating is arranged on the inner surface of the gas bag, on which the hydrochloric acid is neutralized or absorbed.

1 . A method for inflating a gas bag of a safety arrangement in vehicles comprising the step of: providing a gas generator and a gas bag connected to the gas generator, the gas generator containing a pyrotechnic propellant consisting essentially of one or more of an organic fuel and ammonium perchlorate and, in relation to the weight of the fuel and ammonium perchlorate, between 0 and 10 percent by weight of conventional additives, and the gas bag having a coating arranged on an inner surface of the gas bag; activating the pyrotechnic propellant, thereby releasing a gas which contains an amount of hydrochloric acid, supplying the gas to the gas bag, and neutralizing or absorbing the hydrochloric acid on the coating in the gas bag.  
     
     
         2 . The method according to  claim 1 , characterized in that the coating comprises an amount of chemical substances which are reacted immediately with the hydrochloric acid to convert the hydrochloric acid into harmless solid reaction products.  
     
     
         3 . The method according to  claim 2 , characterized in that the chemical substances are selected from the group consisting of the oxides, peroxides, hydroxides, carbonates, hydrogen carbonates and oxalates of alkali metals, alkaline earth metals and transition metals and mixtures thereof.  
     
     
         4 . The method according to  claim 2 , characterized in that the chemical substances are selected from the group consisting of organic amines and polymeric compounds with basic functional groups.  
     
     
         5 . The method according to  claim 4 , characterized in that the polymeric compounds are selected from the group of polyamines and ion exchanger resins.  
     
     
         6 . The method according to any of claims  1 , characterized in that the coating comprises surface-active substances capable of absorbing hydrochloric acid.  
     
     
         7 . The method according to  claim 6 , characterized in that the surface-active substances are selected from the group consisting of synthetic silicic acid, aluminium oxide and aluminium hydroxide, titanium dioxide, activated carbon, soot, nanopowder and mixtures thereof.  
     
     
         8 . A method for inflating a gas bag of a safety arrangement in vehicles comprising the steps of: providing a gas generator and a gas bag connected to said gas generator, the gas generator containing a pyrotechnic propellant consisting essentially of one or more of an organic fuel and ammonium perchlorate and, in relation to the weight of fuel and ammonium perchlorate, between about 0 and 10 percent by weight of conventional additives; activating the pyrotechnic propellant, thereby releasing a gas, which contains an amount of hydrochloric acid; and, concurrently with the activation of the pyrotechnic propellant, releasing and supplying chemical substances from said gas generator to the gas bag, which react in the gas bag immediately with the hydrochloric acid and convert the hydrochloric acid into harmless solid reaction products.  
     
     
         9 . A gas bag module for use in a safety arrangement in vehicles, comprising a gas bag and a gas generator connected to the gas bag, the gas generator containing a pyrotechnic propellant which consists essentially of one or more of an organic fuel and ammonium perchlorate and, in relation to the weight of the fuel and the ammonium perchlorate, between about 0 and 10 percent by weight of conventional additives, and the gas bag having a coating adapted for the neutralization or absorption of hydrochloric acid released from the pyrotechnic propellant.  
     
     
         10 . The gas bag module according to  claim 10 , characterized in that the pyrotechnic propellant consists of the organic fuel and ammonium perchlorate.  
     
     
         11 . The gas bag module according to  claim 9 , characterized in that the pyrotechnic propellant has a gas yield, related to mass, of over 95 percent.  
     
     
         12 . The gas bag module according to  claim 9 , characterized in that the coating comprises an effective amount of chemical substances which are adapted for reacting immediately with the hydrochloric acid.  
     
     
         13 . The gas bag module according to  claim 12 , characterized in that the chemical substances are selected from the group consisting of the oxides, peroxides, hydroxides, carbonates, hydrogen carbonates and oxalates of alkali metals, alkaline earth metals and transition metals and mixtures thereof.  
     
     
         14 . The gas bag module according to  claim 12 , characterized in that the chemical substances are selected from the group consisting of organic amines and polymeric compounds with basic functional groups.  
     
     
         15 . The gas bag module according to  claim 14 , characterized in that the polymeric compounds are selected from the group of polyamines and ion exchanger resins.  
     
     
         16 . The gas bag module according to  claim 9 , characterized in that the coating comprises surface-active substances with a capability of absorbing hydrochloric acid.  
     
     
         17 . The gas bag module according to  claim 16 , characterized in that the surface-active substances are selected from the group consisting of synthetic silicic acid, aluminium oxide and aluminium hydroxide, titanium dioxide, activated carbon, soot, nanopowder and mixtures thereof.