Enhanced thermal and ignition stability azide gas generant intermediates
US5437229A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1993 |
| Grant date | Aug 1, 1995 |
| Priority date | — |
| Expiry date | Apr 8, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC06D5/06
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Slurry and spray dried azide-based gas generant intermediates are made having a hydrazoic acid content of less than about 3.times.10 EXP(-3) M/L, a pH of greater than 8.0 up to about 12.5, and impurity metal ions Ca, Mg, Pb, Fe, Mn and Cu, each below about 25 ppm. These intermediates are made by slurrying powdered ingredients of the azide and oxidizer/reactant in water, wet grinding the slurry and spray drying to form a particulate material which is molded into pellets or tablets which are useful as the gas generant in vehicle crash bags or inflators. The basicity of the water is adjusted to a pH of greater than 8.0 up to about 12.5, preferably about 10, by the addition of a base, such as NaOH, followed by the addition of such solid ingredients as S, MoS.sub.2 and NaN.sub.3, and preferably the NaN.sub.3 is added last, whereby hydrazoic acid production is minimized. The contaminant Ca and Mg ions are minimized by softening the water supplied. Impurity ions are also minimized by being precipitated as non-hazardous compounds by adding such agents as sodium sulfide and tri-sodium phosphate to the slurry. Impurities in the MoS.sub.2 feed may be further minimized by chemical leaching pur…
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