Atlantic Research Corporation

Aerojet-general Corporation

Norman H Lundstrom

Robert S Scheffee

Aaron J Greso

Brian K Wheatley

James D Martin

Daniel S Luke

Robert D Lynch

Aaron J Gresco

Robert S Scheffe

R Stephen Scheffee

Nondetonable, or low detonation sensitivity, substantially nontoxic liquid monopropellants are provided. The liquid propellants are formed from aqueous solutions of solid oxidizers in liquid oxidizers and water soluble liquid fuels and formulated to have a freezing point less than &#x2212;10&#xb0; C. Liquid oxidizers may be inorganic or organic aqueous solutions, with hydrogen peroxide being preferred. Preferred solid oxidizers are water soluble nitrates including ammonium dinitramide, aminoguanidine dinitrate, ammonium nitrate, hydroxylamine nitrate, hydrazine nitrate, guanidine nitrate and aminoguanidine nitrate. Preferred liquid fuels are water soluble alcohols, amines and amine nitrates, hydroxyethyl hydrazine, hydroxyethylhydrazine nitrate, cyanoguanidine, guanidines, aminoguanidines, triaminoguanidines, and their nitrate salts, ethanolamine dinitrate, ethylenediamine dinitrate, polyvinyl nitrate, and aziridine.

Premixed liquid monopropellant solutions and mixtures

Gas generant compositions exhibit low autoignition temperatures. In preferred forms, the gas generant compositions include azobisformamidine dinitrate (AZODN) and a eutectic mixture (comelt) of silver nitrate and potassium nitrate. The comelt of silver nitrate and potassium nitrate is most preferably present in the formulations of the invention in an amount to achieve a low autoignition temperature of between about 140&deg; C. (284&deg; F.) to about 160&deg; C. (320&deg; F.). The compositions of the invention may include a variety of auxiliary components typically employed in conventional gas generant compositions for their intended purpose. For example, especially preferred formulations of the present invention will include a powdered metal or metal oxide as a combustion catalyst to speed the decomposition reaction and also as a combustion aid to facilitate the ignition of the primary propellant or gas generant.

Gas generant compositions exhibiting low autoignition temperatures and methods of generating gases therefrom

A pyrotechnic gas generant composition includes a high oxygen balance compound or fuel, preferably, azodiformamidine dinitrate, which is the resulting reaction product of an aminoguanidine salt and nitric acid. Specifically, the high oxygen balance compound or fuel of the present invention is the resulting reaction product of aminoguanidine salts, such as aminoguanidine nitrate, aminoguanidine bicarbonate, or aminoguanidine sulfate with nitric acid. Preferably, the aminoguanidine salt is aminoguanidine bicarbonate. The resulting reaction product is a yellow precipitate that can be used alone, with or without oxidizers or other additives, for very rapid self-deflagration or in combination with oxidizers and additives. In each instance, the gas generant composition provides both high gas output and low production of solid combustion products. Further, the precipitant is relatively non-hygroscopic and has a high burn rate. The gas generating composition is useful as a gas generator for an air bag of an occupant restraint system for an automobile, gun propellants, inflation and expulsion devices, flotation devices, pyrotechnics, fire suppression devices and smokeless, reduced smoke and smokey rocket propellants.

Method for the gas-inflation articles

Solid gas generant compositions produce low particulates (e.g., condensed ash) when ignited. The solid gas generant compositions most preferably include a nitramine, at least one oxidizer selected from nitrates of strontium or cerium, in admixture with or without potassium perchlorate, and a binder. Graphite may optionally be employed. The gas generant compositions are usefully employed in inflatable vehicle occupant passive restraint systems (e.g., air bag systems).

Low ash gas generant and ignition compositions for vehicle occupant passive restraint systems

Chemical delivery systems for fire suppression

Solid pyrotechnic gas generant compositions and monopropellants are provided for use in inflators of automotive air bag restraint systems which, when combusted, produce acceptable burning rates, generate a high concentration of substantially innocuous gases, and a low concentration of substantially water insoluble non-toxic solid combustion products which limits the potential for asthmatic and pulmonary conditions. The propellant compositions provided are based on metal salts of lanthanide and rare earth elements, particularly lanthanide or rare earth nitrate salts and lanthanide or rare earth complexes with nitrogen-containing cations and nitrate anions. Scandium and cerium are preferred lanthanide and rare earth elements for these compositions.

Propellant compositions with salts and complexes of lanthanide and rare earth elements

Gas generative compositions especially useful in inflators for protective passive restraint devices (e.g., motor vehicle air bags, escape slide chutes, lift rafts, and the like) include a nitrogen-containing fuel and an oxidizer selected from copper (II) oxide (CuO), cupric nitrate, basic copper nitrate (Cu(NO.sub.3).sub.2.3Cu(OH.sub.2), strontium nitrate (Sr(NO.sub.3).sub.2) and mixtures thereof. Most preferably the nitrogen-containing fuel is azodicarbonamidine dinitrate (AZODN) and/or 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20). The compositions of the present invention provide high burning rates with acceptable burning rate pressure exponents which allow their operation at lower pressures, thereby resulting in the use of less costly, lower weight, and lower strength materials for design and manufacture of the inflator pressure vessel.

Gas generative compositions

Chlorate-free autoignition compositions are disclosed, and may be embodied in compositions comprised of (i) an azodiformamidine dinitrate (ADFD), a self-deflagrating, low ignition temperature fuel, (ii) an oxidizer (e.g., a perchlorate, nitrate or mixture thereof) and (iii) an ignition accelerator/augmentor (e.g., a metal or metal oxide powder). One especially preferred solid AIP composition in accordance with the present invention includes ADFD, a mixture of ammonium perchlorate and sodium nitrate, an iron oxide powder and a binder, such as a poly(alkylene carbonate).

Chlorate-free autoignition compositions and methods

A nonazide gas generant that may be used in an inflation device, such as a vehicle passenger restraint system, comprising a hydrated or anhydrous mixture of nonazide fuel, an oxidizer and a quantity of copper phthalocyanine, otherwise known as Monarch Blue and/or azodicarbonamidine dinitrate. Specifically, the nonazide gas generant composition of the present invention may include phase stabilized ammonium nitrate (PSAN), high bulk density nitroguanidine (HBNQ), one or more nonazide fuels, a quantity of copper phthalocyanine and/or azodicarbonamidine dinitrate and optionally a binder. The gas generant composition of the present invention is capable of self-sustained burning at low or ambient temperatures and pressures, important for use in dual stage 'smart' inflator automotive passenger restraint systems, while exhibiting a relatively high gas volume to solid particulate ratio upon combustion at acceptable flame temperatures. The composition also exhibits a tailorable burning rate and properties to preclude catastrophic events during cook off tests.

Nonazide ammonium nitrate based gas generant compositions that burn at

A pyrotechnic gas generant composition including a high oxygen balance compound or fuel which is the resulting reaction product of aminoguanidine nitrate and nitric acid. Specifically, the resulting reaction product is a yellow precipitate that can be used alone, with or without oxidizers or other additives, for very rapid self-deflagration or in combination with oxidizers and additives. In each instance, the gas generant composition provides both high gas output and low production of solid combustion products. Further, the precipitant is relatively non-hygroscopic and has a high burn rate. Specifically, the gas generating composition is useful as a gas generator for an air bag of an occupant restraint system for an automobile, gun propellants, inflation and expulsion devices, flotation devices, pyrotechnics, fire suppression devices and smokeless, reduced smoke and smokey rocket propellants.

Pyrotechnic gas generant composition including high oxygen balance fuel

A pyrotechnic gas generant composition including a high oxygen balance fuel that is the resulting reaction product of an aminoguanidine or polyaminoguanidine salt and nitric acid, namely, aminoguanidine dinitrate, diaminoguanidine dinitrate, and triaminoguanidine dinitrate. Specifically, aminoguanidine dinitrate, diaminoguanidine dinitrate, and triaminoguanidine dinitrate can be used as monopropellants or in combination with oxidizers and additives as a solid bipropellant composition. In each instance, the high oxygen balance fuel(s) of the present invention provide(s) both high gas output and low production of solid combustion products. Specifically, the high oxygen balance fuel(s) may be incorporated into gas generators, gun propellants, inflation and expulsion devices, flotation devices, pyrotechnics, fire suppression devices and smokeless, reduced smoke and metallized rocket propellants.

Growing community of inventors

Manassas, VA, United States of America

Norman H Lundstrom