Gas generant igniter coating materials and methods

• US 20040089383A1
• Filed: 02/06/2003
• Published: 05/13/2004
• Est. Priority Date: 02/06/2003
• Status: Abandoned Application

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Taylor, Robert D., Mendenhall, Ivan V.
• Application Number:
  US10/359,962
• Publication Number:
  US 20040089383A1
• Time in Patent Office: Days
• US Class Current: 149/19.2
• CPC Class Codes: C06B 21/0083 Treatment of solid structures, e.g. for coating or impregnating with a modifier compositions therefor C06B23/00
• CPC Class Codes: C06B 33/04 the material being an inorganic nitrogen-oxygen salt
• CPC Class Codes: C06C 9/00 Chemical contact igniters; Chemical lighters

Abstract

Gas generant grains, such as tablets, granules or particulates, are coated with a dispersion of oxidizer particulates, metal fuel particulates, a fluoropolymer binder with which at least a portion of the metal fuel is reactive, and a solvent for the fluoropolymer.

Claims

1. An ignition material comprising:

finely divided particulates of metal fuel, the metal fuel being reactive with fluorine moieties of a fluoropolymer,

finely divided oxidizer particulates, and

a fluoropolymer binder in which the finely divided particulates of metal fuel and the finely divided oxidizer particulates are substantially uniformly distributed.

2. The ignition material of claim 1 comprising the oxidizer particulates at between about 55 and about 75 wt. %, the metal particulates at between about 10 and about 40 wt. %, and the fluoropolymer binder at between about 1 and about 5 wt. %, said weight percentages being based on total weight of ignition material.

3. The ignition material of claim 1 wherein the metal fuel is selected from the group consisting of magnesium, aluminum, boron, beryllium, calcium, strontium, barium, sodium lithium, titanium and zirconium, mixtures of these metals and alloys of these metals.

4. The ignition material of claim 1 comprising magnesium.

5. The ignition material of claim 1 comprising aluminum.

6. The ignition material of claim 1 comprising boron.

7. The ignition material of claim 1 comprising a mixture or alloy of magnesium and aluminum.

8. The ignition material of claim 7 further comprising boron.

9. The material of claim 1 wherein the metal fuel comprises between about 20 and about 50 wt. % magnesium and between about 50 and about 80 wt. % aluminum, said weight percentages of magnesium and aluminum being based on total weight of magnesium and aluminum, and 0 to 20 wt. % boron, said weight percentage of being based on total weight of ignition material.

10. The ignition material of claim 9 containing at least 1 wt. % boron, said weight percentage of being based on total weight of ignition material.

11. The ignition material of claim 1 additionally comprising up to about 10 wt. % of a desensitizing additive, said weight percentage being based on total weight of ignition material.

12. The ignition material of claim 11 wherein the ignition material includes the desensitizing agent bentonite clay.

13. The ignition material of claim 1 in a form suitable for coating a substrate further comprising a solvent for said fluoropolymer binder in an amount sufficient to dissolve said fluoropolymer binder.

14. A method of providing an ignition material-coated gas generant substrate comprising providing a gas generant substrate and coating the gas generant substrate with the ignition material of claim 13.

15. The method of claim 14 wherein the ignition material is coated on the gas generant substrate by spray coating.

16. An ignition material-coated gas generant formulation comprising a gas generant having a coating of the ignition material of claim 1.

17. The ignition material-coated gas generant formulation of claim 16, wherein the substrate is a gas generant grain having a maximum weight of about 3.0 grams and the ignition material-coated gas generant formulation is capable of self-ignition.

18. An ignition material useful for coating a gas generant material substrate, the ignition material comprising oxidizer particulates, fuel particulates comprising metal fuel, and a fluoropolymer reactive with the metal fuel, the fluoropolymer being present at a level of between about 1 and about 5 wt. % of the ignition material.

19. The ignition material of claim 18 wherein the oxidizer particulates are present at a level of between about 55 and about 75 wt. % of ignition material and the metal particulates are present at between about 10 and about 40 wt. % of ignition material.

20. The ignition material of claim 19 additionally comprising up to about 10 wt. % of a desensitizing additive, said weight percentage being based on total weight of ignition material.

21. An ignition material-coated gas generant comprising a gas generant material substrate having a coating of the ignition material of claim 18.

22. The ignition material-coated gas generant of claim 21, wherein the gas generant material substrate is a gas generant grain having a maximum weight of about 3.0 grams and wherein the ignition material-coated gas generant is capable of self-ignition.

23. A method of coating a gas generant material to provide an adherent ignition material film thereon;

the method comprising,

dissolving a fluoropolymer in a solvent to form a fluoropolymer solution,

dispersing particulates of oxidizer and fuel in the fluoropolymer solution to form a dispersion, and

coating a gas generant substrate with the dispersion.

24. The method of claim 23 wherein the fluoropolymer comprises between about 1 and about 5 wt. % of the dispersion, exclusive of the solvent.

25. The method of claim 23 wherein the dispersion is coated onto the gas generant substrate by spray coating.

26. The method of claim 23 wherein the dispersion is coated onto the gas generant substrate by spray coating in a fluidized bed.

27. The method according to claim 23 wherein the gas generant substrate is a gas generant grain having a maximum weight of about 3.0 grams, the coated gas generant substrate is capable of self-ignition.