Stable initiator compositions and igniters

• US 20050258159A1
• Filed: 05/20/2004
• Published: 11/24/2005
• Est. Priority Date: 05/20/2004
• Status: Active Grant

• Current Assignee: Alexza Pharmaceuticals Inc. (Grupo Ferrer Internacional SA)
• Original Assignee: Alexza Molecular Delivery Corporation (Grupo Ferrer Internacional SA)
• Inventors: Tom, Curtis, Hale, Ron L., Solas, Dennis W., Pettit, Hilary N., Lei, Mingzu, Song, Soonho
• Granted Patent: US 7,402,777 B2
• Time in Patent Office: Days
• US Class Current: 219/270
• CPC Class Codes: F23Q 3/006 Details sparking-plugs H01T13/00

Abstract

High sparking initiator compositions with a controlled amount of power are disclosed. The initiator compositions comprise a metal containing oxidizing agent, at least one metal reducing agent, and a non-explosive binder. Low voltage igniters that provide bidirectional plumes upon ignition are also disclosed. These igniters have a electrically resistive element positioned across a hole in a support which directs the plume. These igniters and compositions are useful in the actuation of solid fuel heating unit, in particular, sealed heating units.

Claims

1. A reliable high sparking initiator composition comprising

a. a mixture of

i. a metal containing oxidizing agent

ii. at least one metal reducing agent, and

iii. a non-explosive binder

b. wherein said mixture is characterized by release of a total amount of energy between the range of 0.25 J and 8.5 J upon actuation and a deflagration time between the range of 5 to 30 milliseconds at a composition thickness of between about 20 to 100 microns.

2. The initiator composition of claim 1, wherein the deflagration time is less than 20 millisecond.

3. The initiator composition of claim 1, wherein the deflagration time is less than 10 millisecond.

4. The initiator composition of claim 1, wherein said at least one metal reducing agent is selected from the group consisting of:

aluminum, zirconium, and boron,

5. The initiator composition of claim 1, wherein said metal containing oxidizing agent is selected from the group consisting of:

a chlorate of an alkali, a chlorate of an alkali earth metal, a perchlorate of an alkali metal, a perchlorate of an alkali earth metal, and an oxide of a metal.

6. The initiator composition of claim 5, wherein the oxidizing agent is selected from at least one of the following:

molybdenum trioxide, copper oxide, tungsten trioxide, potassium chlorate, and potassium perchlorate.

7. The initiator composition of claim 1, wherein the composition comprises at least two metal reducing agents.

8. The initiator composition of claim 7, wherein at least one of the two metal reducing agents is boron.

9. The initiator composition of claim 8, wherein the boron is present in about 7-10% by weight relative to other oxidizing and reducing agents in the mixture.

10. The initiator composition of claim 1, wherein the metal reducing agent and the metal-containing oxidizing agent comprise powders.

11. This initiator composition of claim 10, wherein at least one of the powders is of a nanoparticle size.

12. The initiator composition of claim 10, wherein both the metal reducing agent and the metal-containing oxidizing agent are powders of nanoparticle size.

13. The initiator composition of claim 1 wherein said compositions comprises 25-75% by weight of said oxidizing agent.

14. The initiator composition of claim 1 wherein said compositions comprises 25-75% by weight of said reducing agent.

15. The initiator composition of claim 1, wherein said composition contains less than about 15 percent by weight of binder, based on total composition dry weight.

16. The initiator composition of claim 1, wherein said composition contains less than 5 percent by weight of binder, based on total composition dry weight.

17. The initiator composition of claim 15, wherein the binder is inert.

18. The initiator composition of claim 17, wherein the binder is selected from the group consisting of Viton or Laponite.

19. The initiator composition of claim 1, wherein said composition is for use with an electrical resistance actuation mechanism.

20. The initiator composition of claim 1, wherein said initiator composition is for use with percussion actuation.

21. The initiator composition of claim 1, wherein said initiator composition is for use with optical actuation.

23. The initiator composition of claim 1 comprising aluminum, molybdenum trioxide, boron and Viton.

22. The initiator composition of claim 22, wherein said optical actuation is a flashbulb.

24. A reliable, high sparking, low voltage, non-explosive initiator composition comprising, based on total composition dry weight, about 26-27% aluminum, 51-52 percent molybdemun trioxide, 7-8 percent boron and 14-15% Viton.

25. A reliable electrical igniter for igniting fuel and forming bidirectional focused plumes comprising:

a. a support with a hole contained therein,

b. at least two conductors in contact with the support,

c. a resistive heating element positioned at least partially across the hole and attached to the conductors, and

d. an initiator composition placed on at least a portion of both sides of the resistive heating element and covering the hole.

26. The igniter of claim 25, wherein said support is a thermally insulating material.

27. The igniter of claim 26, wherein said thermally insulating material is selected from the group consisting of Kapton®

, a fluorcarbon laminate material or FR4 epoxy/fiberglass printed circuit board.

28. The igniter of claim 25, wherein said conductors are copper tracings.

29. The igniter of claim 25, wherein said resistive heating element is selected from a metal or an alloy.

30. The igniter of claim 29, wherein said resistive heating element is in the form of a wire, filament, ribbon or foil.

31. The igniter of claim 30, wherein said resistive heating element is a Nichrome wire.

32. The igniter of claim 31, wherein said wire has a diameter of between about 0.0006 inches to about 0.001 inches.

33. The igniter of claim 31, wherein the resistive heating element has an electrical resistance between the range of about 2 Ω

to 4 Ω

.

34. The igniter of claim 25, wherein said conductors are attached to the resistive heating element by soldering.

35. The igniter of claim 25, wherein said initiator composition is a slurry.

36. The igniter of claim 25, wherein said initiator composition is non-explosive.

37. The igniter of claim 25, wherein said initiator composition is low gas producing.

38. The igniter of claim 25, wherein said initiator composition comprises a mixture of

a. a metal containing oxidizing agent

ii. at least one metal reducing agent, and

iii. a non-explosive binder

39. The igniter of claim 25, wherein said initiator composition comprises by weight of dry solids of between 10 and 20 percent binder, 30 and 40 percent of reducing agent, and 40 to 60 percent of a metal containing oxidizing agent.

40. The igniter of claim 25, wherein said initiator composition comprising a mixture of boron, aluminum, molybdenum trioxide and Viton.

41. The igniter of claim 25, wherein said igniter is characterized by an onset of deflagration of less than 50 milliseconds upon actuation.

42. The igniter of claim 25, wherein said igniter is characterized by an onset of deflagration of less than 10 milliseconds upon actuation.

43. The igniter of claim 25, wherein said igniter is characterized by an onset of deflagration of less than 6 milliseconds upon actuation.

44. A method of making a reliable igniter that upon ignition has bidirectional focused plumes comprising the steps of:

a. depositing two conductors on a support with an hole contained therein

b. attaching a resistive heating element between the conductors and positioned across the hole

c. dispensing a initiator composition on one side of the resistive heating element thereby covering at least a portion of the hole on the support

d. drying the dispensed initiator composition;

e. dispensing a second time the initiator composition on the opposite side of the resistive heating element and in the hole from the first dispensing thereby covering the hole; and

f. drying the second dispensed initiator composition.

45. The method of claim 44, wherein said support is a thermally insulating material.

46. The method of claim 45, wherein said thermally insulating material is selected from the group consisting of Kapton®

or FR4 epoxy/fiberglass printed circuit board.

47. The method of claim 44, wherein said conductors are copper tracings.

48. The method of claim 44, wherein said resistive heating element is selected from a metal or an alloy.

49. The method of claim 44, wherein said resistive heating element is in the form of a wire, filament, ribbon or foil.

50. The method of claim 44, wherein said resistive heating element is a Nichrome wire.

53. The method of claim 44, wherein said drying is air drying.

54. The method of claim 44, wherein said attaching comprising soldering.

55. The method of claim 44, wherein said initiator composition is a slurry.

56. The method of claim 44, wherein said initiator composition is non-explosive.

57. The method of claim 44, wherein said initiator composition is low gas producing.

58. The method of claim 44, wherein said dispensing is by an automatic dispensing device.

59. The method of claim 44, wherein said initiator composition comprises a mixture of

a. a metal containing oxidizing agent

b. at least one metal reducing agent, and

c. a non-explosive binder

60. The method of claim 44, wherein said initiator composition comprising a mixture of boron, aluminum, molybdenum trioxide and Viton.

51. The method of claim 51, wherein said wire has a diameter of between about 0.0006 to about 0.001 inches.

52. The method of claim 51, wherein the resistive heating element has an electrical resistance between the range of about 2 Ω

to 4 Ω

.