Borohydride fuels in gas generant compositions

• US 5,401,340 A
• Filed: 01/10/1994
• Issued: 03/28/1995
• Est. Priority Date: 08/10/1993
• Status: Expired due to Fees

• Current Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Original Assignee: Thiokol Corporation (Howmet Aerospace, Inc.)
• Inventors: Doll, Dan W., Lund, Gary K., Blau, Reed J., Hinshaw, Jerald C., Wallace, Ingvar A. II
• Primary Examiner(s): Walsh, Donald P.
• Assistant Examiner(s): CHI, ANTHONY
• Application Number:
  US08/179,150
• Time in Patent Office: 442 Days
• Field of Search: 149/37, 149/45, 149/22, 149/75, 149/108.2, 149/109.2, 149/109.4
• US Class Current: 149/22
• CPC Class Codes: C06B 33/00 Compositions containing particulate metal, alloy, boron, silicon, selenium or tellurium with at least one oxygen supplying material which is either a metal oxide or a salt, organic or inorganic, capable of yielding a metal oxide
• CPC Class Codes: C06B 43/00 Compositions characterised by explosive or thermic constituents not provided for in groups C06B25/00 - C06B41/00
• CPC Class Codes: C06D 5/06 by reaction of two or more solids

Abstract

A sodium-azide-free gas-generating composition includes an oxidizable borohydride fuel and an oxidizing agent containing oxygen and a metal. The fuel and the oxidizing agent are selected such that water vapor is produced upon reaction between the borohydride fuel and the oxidizing agent. Suitable oxidizing agents contain a metal and oxygen and are selected from a metal oxide, a metal oxide hydrate, a metal oxide hydroxide, a metal hydrous oxide, a metal hydroxide, or mixtures thereof. The fuel and oxidizing agent are selected such that water vapor is the major gaseous combustion product.

Claims

1. A solid gas-generating composition comprising an oxidizable borohydride fuel and an oxidizing agent, wherein said oxidizing agent comprises at least one member selected from the group consisting of a metal oxide, a metal oxide hydrate, a metal oxide hydroxide, a metal hydrous oxide, a metal hydroxide, or mixtures thereof, and wherein water vapor is the major gaseous reaction product generated by reaction between said oxidizable borohydride fuel and said oxidizing agent.

2. A solid gas-generating composition according to claim 1, comprising from about 5 wt. % to about 40 wt. % borohydride fuel and from about 95 wt. % to about 60 wt. % oxidizing agent.

3. A solid gas-generating composition according to claim 1, wherein the oxidizable borohydride fuel is selected from salts or complexes of BH₄^-, B₃ H₈^-, B₈ H₈^2-, B₉ H₁₅, B₁₀ H₁₄, B₁₀ H₁₀^2-, B₁₁ H₁₄^-, B₁₂ H₁₂^2-, and mixtures thereof.

4. A solid gas-generating composition according to claim 1, wherein the oxidizable borohydride fuel is based on BH₄^-.

5. A solid gas-generating composition according to claim 4, wherein the oxidizable borohydride fuel is selected from LiBH₄, NaBH₄, KBH₄, RbBH₄, CsBH₄, Mg(BH₄)₂, Ca(BH₄)₂, Ba(BH₄)₂, Al(BH₄)₃, Zn(BH₄)₃, transition metal complexes of BH₄^-, and mixtures thereof.

6. A solid gas-generating composition according to claim 1, wherein the oxidizable borohydride fuel and the oxidizer are in the form of a finely divided powder.

7. A solid gas-generating composition according to claim 6, wherein the particle size range of the powder is from about 0,001 μ

to about 400 μ

.

8. A solid gas-generating composition according to claim 1, wherein the oxidizing agent is a metal oxide selected from CuO, Co₂ O₃, Co₃ O₄, Bi₂ O₃, Fe₂ O₃, CoFe₂ O₄, and mixtures thereof.

9. A solid gas-generating composition according to claim 1, wherein the oxidizing agent is a metal hydroxide selected from Fe(OH)₃, Co(OH)₃, Co(OH)₂, Ni(OH)₂, Cu(OH)₂, Zn(OH)₂, and mixtures thereof.

10. A solid gas-generating composition according to claim 1, wherein the oxidizing agent is a hydrated metal oxide selected from Fe₂ O₃.xH₂ O, SnO₂.xH₂ O, MoO₃.H₂ O, and mixtures thereof.

11. A solid gas-generating composition according to claim 1, wherein the oxidizing agent is a metal oxide hydroxide selected from MnO(OH), MnO(OH)₂, FeO(OH), MnO(OH)₃, and mixtures thereof.

12. An automobile air bag system comprising:

a collapsed, inflatable air bag;

a gas-generating device connected to the air bag for inflating said air bag, said gas-generating device containing a gas-generating composition comprising an oxidizable borohydride fuel and an oxidizing agent, wherein said oxidizing agent comprises at least one member selected from the group consisting of a metal oxide, a metal oxide hydrate, a metal oxide hydroxide, a metal hydrous oxide, a metal hydroxide, or mixtures thereof, and wherein water vapor is the major gaseous product generated by said solid gas-generating composition;

wherein said oxidizing agent is present in an amount from about 0.5 to about 3 times the stoichiometric amount of oxidizing agent necessary to completely oxidize the borohydride present; and

means for igniting said gas-generating composition.

13. An automobile air bag system according to claim 12, wherein said gas-generating composition comprises from about 5 wt. % to about 40 wt. % oxidizable borohydride fuel and from about 95 wt. % to about 60 wt. % oxidizing agent.

14. An automobile air bag system according to claim 12, wherein the oxidizable borohydride fuel is selected from BH₄^-, B₃ H₈^-, B₈ H₈^2-, B₉ H₁₅, B₁₀ H₁₄, B₁₀ H₁₀^2-, B₁₁ H₁₄^-, B₁₂ H₁₂^2-, and mixtures thereof.

15. An automobile air bag system according to claim 12, wherein the oxidizable borohydride fuel is based on BH₄^-.

16. An automobile air bag system according to claim 15, wherein the oxidizable borohydride fuel is selected from LiBH₄, NaBH₄, KBH₄, RbBH₄, CsBH₄, Mg(BH₄)₂, Ca(BH₄)₂, Ba(BH₄)₂, Al(BH₄)₃, Zn(BH₄)₃, transition metal complexes of BH₄^-, and mixtures thereof.

17. An automobile air bag system according to claim 12, wherein the oxidizing agent is a metal oxide selected from CuO, Co₂ O₃, Co₃ O₄, Bi₂ O₃, Fe₂ O₃, CoFe₂ O₄, and mixtures thereof.

18. An automobile air bag system according to claim 12, wherein the oxidizing agent is a metal hydroxide selected from Fe(OH)₃, Co(OH)₃, Co(OH)₂, Ni(OH)₂, Cu(OH)₂, Zn(OH)₂, and mixtures thereof.

19. An automobile air bag system according to claim 12, wherein the oxidizing agent is a hydrated metal oxide selected from Fe₂ O₃. xH₂ O, SnO₂.xH₂ O, MoO₃ H₂ O, and mixtures thereof.

20. An automobile air bag system according to claim 12, wherein the oxidizing agent is a metal oxide hydroxide selected from MnO(OH), MnO(OH)₂, FeO(OH), MnO(OH)₃, and mixtures thereof.

21. An automobile air bag system having a hybrid gas-generating system comprising:

a collapsed, inflatable air bag;

a pressure tank having a rupturable opening, said pressure tank containing an inert gas;

a gas-generating device for producing hot combustion gases and capable of rupturing the rupturable opening, said gas-generating device being configured in relation to the pressure tank such that hot combustion gases are mixed with and heat the inert gas and wherein said gas-generating device and the pressure tank are connected to the inflatable air bag such that the combustion gases and inert gas are capable of inflating the air bag, said gas-generating device containing a gas-generating composition comprising an oxidizable borohydride fuel and an oxidizing agent, wherein said oxidizing agent comprises at least one member selected from the group consisting of a metal oxide, a metal oxide hydrate, a metal oxide hydroxide, a metal hydrous oxide, a metal hydroxide, or mixtures thereof, and wherein water vapor is the major gaseous product generated by said solid gas-generating composition;

wherein said oxidizing agent is present in an amount from about 0.5 to about 3 times the stoichiometric amount of oxidizing agent necessary to completely oxidize the borohydride present; and

means for igniting the gas-generating composition.

22. An automobile air bag system according to claim 21, wherein said inert gas is argon or helium.

23. An automobile air bag system according to claim 21, wherein said gas-generating composition comprises from about 5% to about 40% borohydride fuel and from about 95% to about 60% oxidizing agent.

24. An automobile air bag system according to claim 21, wherein the oxidizable borohydride fuel is selected from BH₄^-, B₃ H₈^-, B₈ H₈^2-, B₉ H₁₅, B₁₀ H₁₄, B₁₀ H₁₀^2-, B₁₁ H₁₄^-, B₁₂ H₁₂^2-, and mixtures thereof.

25. An automobile air bag system according to claim 21, wherein the oxidizable borohydride fuel is based on BH₄^-.

26. An automobile air bag system according to claim 25, wherein the oxidizable borohydride fuel is selected from LiBH₄, NaBH₄, KBH₄, RbBH₄, CsBH₄, Mg(BH₄)₂, Ca(BH₄)₂, Ba(BH₄)₂, Al(BH₄)₃, Zn(BH₄)₃, transition metal complexes of BH₄^-, and mixtures thereof.

27. An automobile air bag system according to claim 21, wherein the oxidizing agent is a metal oxide selected from CuO, Co₂ O₃, Co₃ O₄, Bi₂ O₃, Fe₂ O₃, CoFe₂ O₄, and mixtures thereof.

28. An automobile air bag system according to claim 21, wherein the oxidizing agent is a metal hydroxide selected from Fe(OH)₃, Co(OH)₃, Co(OH)₂, Ni(OH)₂, Cu(OH)₂, Zn(OH)₂, and mixtures thereof.

29. An automobile air bag system according to claim 21, wherein the oxidizing agent is a hydrated metal oxide selected from Fe₂ O₃.xH₂ O, SnO₂.xH₂ O, MoO₃.H₂ O, and mixtures thereof.

30. An automobile air bag system according to claim 21, wherein the oxidizing agent is a metal oxide hydroxide selected from MnO(OH)₂, MnO(OH)₂, FeO(OH), MnO(OH)₃, and mixtures thereof.

31. A vehicle containing a supplemental restraint system having an air bag system comprising:

a collapsed, inflatable air bag,

a gas-generating device connected to said air bag for inflating said air bag, said gas-generating device containing a gas-generating composition comprising an oxidizable borohydride fuel and an oxidizing agent, wherein said oxidizing agent comprises at least one member selected from the group consisting of a metal oxide, a metal oxide hydrate, a metal oxide hydroxide, a metal hydrous oxide, a metal hydroxide, or mixtures thereof, and wherein water vapor is the major gaseous product generated by said solid gas-generating composition;

wherein said oxidizing agent is present in an amount from about 0.5 to about 3 times the stoichiometric amount of oxidizing agent necessary to completely oxidize the borohydride present; and

means for igniting said gas-generating composition.

32. A vehicle as defined in claim 31, further comprising a pressure tank having a rupturable opening, said pressure tank containing an inert gas;

wherein the gas-generating device produces hot combustion gases capable of rupturing the rupturable opening, and wherein the gas-generating device is configured in relation to the pressure tank such that hot combustion gases are mixed with and heat the inert gas and wherein the gas-generating device and the pressure tank are connected to the inflatable air bag such that the mixture of combustion gases and inert gas are capable of inflating the air bag.