Gas generating compositions and methods for their use are provided. Metal complexes are used as gas generating compositions. These complexes are comprised of a cationic metal template, sufficient oxidizing anion to balance the charge of the complex, and a neutral ligand containing hydrogen and nitrogen. The complexes are formulated such that when the complex combusts nitrogen gas and water vapor is produced. Specific examples of such complexes include metal nitrite ammine, metal nitrate ammine, and metal perchlorate ammine complexes, as well as hydrazine complexes. Such complexes are adaptable for use in gas generating devices such as automobile air bags.

Metal complexes for use as gas generants

To deploy an inflatable member, such as an occupant restraint safety bag in a motor vehicle, a liquid propellant is expelled from a storage reservoir into a reaction chamber through ports created at frangible pressure points in the reservoir wall and ignited by detonation of an explosive charge to generate a non-toxic, bag inflating gas by exothermic reaction

Liquid propellant inflator for vehicle occupant restraint apparatus

Provided is a gas generating agent with a low combustion temperature and good ignition ability. The gas generating agent includes: (a) a fuel; (b) an oxidizing agent including a basic metal nitrate; (c) a basic metal carbonate; and (d) a binder (not including a component selected from starch, etherified starch, methyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, guar gum, etherified guar gum, tamarind gum, poly(vinyl alcohol), polyvinyl ether, polyacrylamide, polyethylene oxide, and polyvinyl pyrrolidone). The fuel of the component (a) includes melamine cyanurate (MC) and nitroguanidine (NQ), with MC/NQ (ratio of contents) of being within a range of 0.20 to 1.50.

Gas generating composition

A low-solids gas generating composition, which is a mixture of a fuel selected for the group consisting of cellulose, cellulose acetate, hexamine, and mixtures thereof, and an oxidizer selected from the group consisting of ceric ammonium nitrate, lithium nitrate, lithium perchlorate, sodium perchlorate, phase stabilized ammonium nitrate, a combination of ammonium nitrate with potassium nitrate, potassium perchlorate, or mixtures thereof, such that the combination is a solid solution, a mixture of ammonium perchlorate and at least one alkali metal salt, and mixtures thereof. The combination of ammonium nitrate with other salts in solid solution is intended to phase stabilize the ammonium nitrate. The oxidizer-fuel mixture is within about 4 percent of stoichiometric balance. Useful alkali metal salts include lithium carbonate, lithium nitrate, sodium nitrate, potassium nitrate, and mixtures thereof. The preferred oxidizers for the gas generating composition of the invention are ceric ammonium nitrate, lithium nitrate, lithium perchlorate, sodium perchlorate, a mixture of ammonium perchlorate and at least one alkali metal salt, and mixtures thereof. In addition, the gas generating composition may include an energizing agent, such as RDX or HMX. The gas generating composition of the invention may further comprise sub-micron fumed silica to reduce moisture contamination and serve as a processing and powder flow aid and/or a binder, and may be in the form of pressed pellets, grains, or granules.

Gas generating compositions

The present invention relates to a low temperature autoignition composition for safely initiating combustion of a main pyrotechnic charge in a gas generator or pyrotechnic device exposed to flame or a high temperature environment. The low temperature autoignition compositions of the invention include a mixture of an oxidizer and a powdered metal, wherein the oxidizer includes a comelt or mixture comprising ammonium nitrate and at least one of an alkali metal nitrate, an alkaline earth metal nitrate, a complex salt nitrate, a dried, hydrated nitrate, an alkali metal chlorate, an alkali metal perchlorate, an alkaline earth metal chlorate, an alkaline earth metal perchlorate, ammonium perchlorate, sodium nitrite, potassium nitrite, silver nitrite, a complex salt nitrite, a solid organic nitrate, a solid organic nitrite, or a solid organic amine, and where the metal fuel and oxidizer are present in amounts sufficient to provide an autoignition composition having an autoignition temperature of no more than about 232° C. The present invention also relates to a method for initiating a gas generating composition or pyrotechnic composition in a gas generator or pyrotechnic device exposed to flame or a high temperature environment. In the method of the invention, the gas generating composition or pyrotechnic composition is placed in thermal contact with a low temperature autoignition composition of the invention.

Method of safely initiating combustion of a gas generant composition using an autoignition composition

A deflagrating composition yielding a gas comprising principally carbon dioxide and water vapor comprises a substantially homogeneous mixture of powders preferably having an average particle size less than about 25 microns. The composition has an oxygen bearing oxidizing powder and an organic reducing powder having the formula CxHyOz, having a melting point greater than about 165 DEG F, and a sufficiently low vapor pressure to have no more than a minute amount of sublimation prior to oxidation by the oxidizing powder upon ignition. The oxidizing powder and reducing power or "fuel" are sufficiently near stoichiometry to produce a gas comprising principally carbon dioxide and water vapor upon combustion for inflation of an automobile restraint bag with a non-toxic, at least partly condensable gas. In one embodiment the mixture further comprises an endothermic decomposition coolant having a thermal decomposition product selected from the class consisting of carbon dioxide and water and decomposable below the combustion temperature of the mixture. A method of this invention comprises inflation of a gas bag by combustion of a mixture like that described above. In one embodiment, the mixture may include a reducible metal oxide having a decomposition temperature in the same range as ferric oxide. In another embodiment the mixture is burned adjacent a reservoir of water for producing vapor for inflating the bag, to be followed by rapid deflation as the vapor condenses.

Vincent O Catanzarite

Papers

Gas generator composition and method