Auto-igniting pyrotechnic booster composition

Abstract

The present invention generally relates to auto-ignition/booster compositions for inflators of occupant restraint systems, for example. An exemplary auto-ignition composition in accordance with the present invention includes a metal chlorate, an auto-ignition fuel selected from the group including sugars and orgainic acids, and a nitrogen-containing secondary fuel.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60 / 539,798 filed on Jan. 28, 2004.BACKGROUND OF THE INVENTION [0002] Auto-ignition materials in automotive air bag inflators allow the device to safely deploy in the event of a fire. By including an auto-ignition composition the likelihood of a safety hazard resulting from the bursting of an inflator is substantially reduced. [0003] On the other hand, pyrotechnic booster compositions raise the operating pressure of a pressure vessel or inflator prior to ignition of the main or primary gas generant. As a result, ready ignition of the primary gas generant is facilitated along with sustained combustion thereof. [0004] Accordingly, most inflators or gas generators for vehicle occupant protection systems, for example, typically include an auto-ignition composition juxtaposed next to a discrete booster composition. In the event of a fire, the auto-ignition compositio...

AI Technical Summary

Benefits of technology

[0006] A pyrotechnic formulation including an auto-ignition fuel, an auto-ignition oxidizer, a booster fuel, a booster oxidizer, and an optional fuel / binder such as silicone that self-ignites at a specific design temperature or temperature range. The pyrotechnic also serves as a booster for pyrotechnic gas generators used as automotive gas generators or air bag inflators. Accordingly, the present compositions may function both as an auto-ignition pyrotechnic and as a booster charge pyrotechnic thereby eliminating the need for two separate compositions in the inflator.

[0007] Furthermore, the booster composition also propagates ignition of the main gas generation through flame and / or heat propagation. The sequence of events for the auto-ignition of an inflator includes the ignition of the auto-ignition material, which subsequently ignites the booster material, which in turn ignites the main gas generating pyrotechnic. This invention eliminates the need for individual auto-ignition and booster pyrotechnics, and replaces them with one single pyrotechnic component, greatly simplifying the inflator design, and improving inflator performance.

[0008] By integrating the auto-ignition and booster compounds into one composition, the single auto-ignition / booster grain can be molded or pressed to fit the desired inflator design. This component would be larger than a single auto-ignition tablet or grain, whereby a greater surface area facilitates increased heat conduction relative to primary gas generant and relative to the auto-ignition function in case of a fire. This single pyrotechnic also enhances the simplicity of the inflator design.

Problems solved by technology

An ongoing challenge is to continue simplification of gas generator manufacturing processes thereby resulting in lower overall costs.

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