Gas generating compositions

• US 5,780,768 A
• Filed: 08/30/1996
• Issued: 07/14/1998
• Est. Priority Date: 03/10/1995
• Status: Expired due to Term

• Current Assignee: Nammo Talley, Inc. (Nammo AS)
• Original Assignee: Nammo Talley, Inc. (Nammo AS)
• Inventors: Haun, Daniel, Ludwig, Christopher P., Knowlton, Gregory D.
• Primary Examiner(s): Anthony, Joseph D.
• Application Number:
  US08/706,198
• Time in Patent Office: 683 Days
• Field of Search: 149/19.1, 149/19.7, 149/45, 149/67, 149/61, 149/62, 149/70, 149/36.76, 149/78.83, 149/92, 149/88, 149/120, 149/190.2
• US Class Current: 149/36
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: C06D 5/06 by reaction of two or more solids

Abstract

A low-solids gas generating composition, comprising a mixture of a fuel selected for the group consisting of guanidine nitrate, nitroguanidine, cellulose, cellulose acetate, hexamine, and mixtures thereof, and an oxidizer selected from the group consisting of ceric ammonium nitrate, lithium nitrate, lithium perchlorate, sodium perchlorate, phase stabilized ammonium nitrate, a combination of ammonium nitrate with potassium nitrate, potassium perchlorate, or mixtures thereof, such that the combination is a solid solution, a mixture of ammonium perchlorate and at least one alkali metal salt, and mixtures thereof, where the fuel is not nitroguanidine when the oxidizer includes ammonium nitrate. The combination of ammonium nitrate with other salts in solid solution is intended to phase stabilize the ammonium nitrate. The oxidizer-fuel mixture is within about 4 percent of stoichiometric balance. Useful alkali metal salts include lithium carbonate, lithium nitrate, sodium nitrate, potassium nitrate, and mixtures thereof. The preferred oxidizers for the gas generating composition of the invention are ceric ammonium nitrate, lithium nitrate, lithium perchlorate, sodium perchlorate, a mixture of ammonium perchlorate and at least one alkali metal salt, and mixtures thereof. The preferred fuels are guanidine nitrate, nitroguanidine, and mixtures thereof. In addition, the gas generating composition may include an energizing agent, such as RDX or HMX. The gas generating composition of the invention may further comprise sub-micron fumed silica to reduce moisture contamination and serve as a processing and powder flow aid and/or a binder, and may be in the form of pressed pellets, grains, or granules.

Claims

1. A low-solids gas generating composition, comprising a mixture of a fuel selected for the group consisting of guanidine nitrate, nitroguanidine, and mixtures thereof, and an oxidizer selected from the group consisting of ceric ammonium nitrate, lithium nitrate, lithium perchlorate, sodium perchlorate, a mixture of ammonium perchlorate and at least one alkali metal salt, and mixtures thereof, wherein the oxidizer-fuel mixture is within about 4 percent of stoichiometric balance, and produces no more than about 30 percent solids on combustion.

2. The gas generating composition of claim 1, wherein the alkali metal salt is selected from the group consisting of lithium carbonate, lithium nitrate, sodium nitrate, potassium nitrate, and mixtures thereof.

3. The gas generating composition of claim 2, further comprising sub-micron fumed silica.

4. The gas generating composition of claim 2, wherein the fuel further comprises at least one of cellulose, cellulose acetate or hexamine.

5. The gas generating composition of claim 2, wherein the gas generant is in the form of pressed pellets, grains, or granules.

6. The gas generating composition of claim 1, further comprising an energizing agent.

7. The gas generating composition of claim 6, wherein the energizing agent is selected from the group consisting of RDX and HMX.

8. The gas generating composition of claim 7, comprising guanidine nitrate, RDX, HMX, or mixtures thereof and an oxidizer comprising a mixture of ammonium perchlorate and sodium nitrate.

9. The gas generating composition of claim 8, comprising from about 12 to about 52 percent by weight guanidine nitrate, from about 15 to about 45 percent by weight RDX, HMX, or mixtures thereof and from about 31 to about 45 percent by weight oxidizer, wherein the oxidizer comprises ammonium perchlorate and sodium nitrate in a mole ratio of about 1 mole of ammonium perchlorate to about 1 to about 4 moles of sodium nitrate.

10. The gas generating composition of claim 9, comprising about 30 percent by weight guanidine nitrate, about 32 percent by weight RDX, HMX, or mixtures thereof, about 21 percent by weight ammonium perchlorate, and about 17 percent by weight sodium nitrate.

11. The gas generating composition of claim 1, comprising guanidine nitrate and an oxidizer comprising a mixture of ammonium perchlorate and sodium nitrate.

12. The gas generating composition of claim 11, comprising from about 54 to about 67 percent by weight guanidine nitrate and from about 33 to about 46 percent by weight oxidizer, wherein the oxidizer comprises ammonium perchlorate and sodium nitrate in a mole ratio of about 1 mole of ammonium perchlorate to about 1 to about 4 moles of sodium nitrate.

13. The gas generating composition of claim 12, comprising about 59 percent by weight guanidine nitrate, about 23 percent by weight ammonium perchlorate, and about 18 percent by weight sodium nitrate.

14. The gas generating composition of claim 1, comprising guanidine nitrate and an oxidizer comprising a mixture of ammonium perchlorate and lithium carbonate.

15. The gas generating composition of claim 14, comprising from about 41 to about 57 percent by weight guanidine nitrate and from about 43 to about 59 percent by weight oxidizer, wherein the oxidizer comprises ammonium perchlorate and lithium carbonate in a mole ratio of about 1 mole of ammonium perchlorate to about 1 to about 1.4 moles of lithium carbonate.

16. The gas generating composition of claim 15, comprising about 47 percent by weight guanidine nitrate, about 40 percent by weight ammonium perchlorate, and about 13 percent by weight lithium carbonate.

17. The gas generating composition of claim 1, comprising guanidine nitrate and an oxidizer comprising a mixture of ammonium perchlorate and lithium nitrate.

18. The gas generating composition of claim 17, comprising from about 56 to about 68 percent by weight guanidine nitrate and from about 32 to about 44 percent by weight oxidizer, wherein the oxidizer comprises ammonium perchlorate and lithium nitrate in a mole ratio of about 1 mole of ammonium perchlorate to about 1 to about 8 moles of lithium nitrate.

19. The gas generating composition of claim 18, comprising about 61 percent by weight guanidine nitrate, about 24 percent by weight ammonium perchlorate, and about 15 percent by weight lithium nitrate.

20. The gas generating composition of claim 1, comprising guanidine nitrate and an oxidizer comprising a mixture of ammonium perchlorate and potassium nitrate.

21. The gas generating composition of claim 20, comprising from about 50 to about 64 percent by weight guanidine nitrate and from about 36 to about 50 percent by weight oxidizer, wherein the oxidizer comprises ammonium perchlorate and potassium nitrate in a mole ratio of about 1 mole of ammonium perchlorate to about 1 to about 2 moles of potassium nitrate.

22. The gas generating composition of claim 21, comprising about 57 percent by weight guanidine nitrate, about 23 percent by weight ammonium perchlorate, and about 20 percent by weight potassium nitrate.

23. The gas generating composition of claim 1, comprising guanidine nitrate and ceric ammonium nitrate.

24. The gas generating composition of claim 23, comprising from about 51 to about 65 percent by weight guanidine nitrate and from about 35 to about 49 percent by weight ceric ammonium nitrate.

25. The gas generating composition of claim 24, comprising about 56 percent by weight guanidine nitrate and about 44 percent by weight ceric ammonium nitrate.

26. The gas generating composition of claim 1, comprising guanidine nitrate and lithium nitrate.

27. The gas generating composition of claim 20, comprising from about 61 to about 70 percent by weight guanidine nitrate and from about 30 to about 39 percent by weight lithium nitrate.

28. The gas generating composition of claim 27, comprising about 68 percent by weight guanidine nitrate and about 32 percent by weight lithium nitrate.

29. The gas generating composition of claim 1, comprising guanidine nitrate and lithium perchlorate.

30. The gas generating composition of claim 29, comprising from about 65 to about 75 percent by weight guanidine nitrate and from about 25 to about 35 percent by weight lithium perchlorate.

31. The gas generating composition of claim 30, comprising about 68 percent by weight guanidine nitrate and about 32 percent by weight lithium perchlorate.

32. The gas generating composition of claim 1, comprising nitroguanidine and an oxidizer comprising a mixture of ammonium perchlorate and lithium carbonate.

33. The gas generating composition of claim 32, comprising from about 38 to about 53 percent by weight nitroguanidine and from about 47 to about 62 percent by weight oxidizer, wherein the oxidizer comprises ammonium perchlorate and lithium carbonate in a mole ratio of about 1 mole of ammonium perchlorate to about 1 to about 1.3 moles of lithium carbonate.

34. The gas generating composition of claim 33, comprising about 44 percent by weight nitroguanidine, about 42 percent by weight ammonium perchlorate, and about 14 percent by weight lithium carbonate.

35. The gas generating composition of claim 1, comprising nitroguanidine and an oxidizer comprising a mixture of ammonium perchlorate and sodium nitrate.

36. The gas generating composition of claim 35, comprising from about 50 to about 62 percent by weight nitroguanidine, and from about 38 to about 50 percent by weight oxidizer, wherein the oxidizer comprises ammonium perchlorate and sodium nitrate in a mole ratio of about 1 mole of ammonium perchlorate to about 1 to about 3 moles of sodium nitrate.

37. The gas generating composition of claim 36, comprising about 55 percent by weight nitroguanidine, about 26 percent by weight ammonium perchlorate, and about 19 percent by weight sodium nitrate.

38. The gas generating composition of claim 1, comprising nitroguanidine and lithium perchlorate.

39. The gas generating composition of claim 38, comprising from about 62 to about 71 percent by weight nitroguanidine, and from about 29 to about 38 percent by weight lithium perchlorate.

40. The gas generating composition of claim 39 comprising about 65 percent by weight nitroguanidine and about 35 percent by weight lithium perchlorate.

41. The gas generating composition of claim 1, comprising nitroguanidine and ceric ammonium nitrate.

42. The gas generating composition of claim 41, comprising from about 48 to about 61 percent by weight nitroguanidine and from about 39 to about 52 percent by weight ceric ammonium nitrate.

43. The gas generating composition of claim 42, comprising about 53 percent by weight nitroguanidine and about 47 percent by weight ceric ammonium nitrate.