Moisture-resistant black powder substitute compositions and method for making same

• US 20050072501A1
• Filed: 07/31/2003
• Published: 04/07/2005
• Est. Priority Date: 01/12/2001
• Status: Active Grant

• Current Assignee: Army US Gov'T As Represented By The Secretary of, Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Inventors: Blau, Reed J., Chen, Gary, Schaefer, Ruth A., Bodily, Marlin
• Granted Patent: US 7,459,043 B2
• Time in Patent Office: Days
• US Class Current: 149/19.100
• CPC Class Codes: C06B 31/08 with a metal oxygen-halogen salt, e.g. inorganic chlorate, inorganic perchlorate
• CPC Class Codes: C06B 31/30 with vegetable matter; with resin; with rubber
• CPC Class Codes: C06C 9/00 Chemical contact igniters; Chemical lighters

Abstract

A solid pyrotechnic composition having a flame temperature and exhibiting ballistic performance comparable to that of black powder, but which does not contain charcoal or sulfur, is provided, as is a method for making such composition. A solid pyrotechnic composition, and method for making the same, which has a flame temperature and exhibits ballistic performance comparable to that of boron/potassium nitrate and that is preferably free of boron is also provided.

Claims

1. A method for making a solid pyrotechnic composition having a total weight, comprising:

dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound to produce a dry mixture;

slurrying the dry mixture in a suitable solvent to produce a wet mixture; and

combining the wet mixture with oxidizer particles to form a pyrotechnic composition.

2. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one nonhygroscopic binder having a moisture uptake of not more than about 4.0 weight percent at 75.0% relative humidity at a temperature of 21.1°

C. over a period of 24 hours with the at least one organic crystalline compound.

3. The method of claim 2, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder comprising not more than about 10.0 weight percent of the total weight of the solid pyrotechnic composition with the at least one organic crystalline compound.

4. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder comprising between about 2.0 weight percent and about 6.0 weight percent of the total weight of the solid pyrotechnic composition with the at least one organic crystalline compound.

5. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder comprising about 3.0 weight percent of the total weight of the solid pyrotechnic composition with the at least one organic crystalline compound.

6. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending ethyl cellulose with the at least one organic crystalline compound.

7. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending poly(vinyl acetate) with the at least one organic crystalline compound.

8. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one member selected from the group consisting of poly(vinyl acetate-co vinyl alcohol), nylon, poly(ethylene-co-vinyl acetate), polyethylene glycol, nitrocellulose and chain-extended BAMO with the at least one organic crystalline compound.

9. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprising between about 10.0 weight percent and about 60.0 weight percent of the total weight of the solid pyrotechnic composition.

10. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder with at least one member selected from the group consisting of phenolphthalein and an organic crystalline compound derived from a reaction between a phenolic compound and phthalic anhydride.

11. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder with phenolphthalein.

12. The method of claim 11, wherein dry blending at least one nonhygroscopic polymeric binder with phenolphthalein comprises dry blending at least one nonhygroscopic polymeric binder with phenolphthalein comprising between about 13.0 weight percent and 22.0 weight percent of the total weight of the solid pyrotechnic composition.

13. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound and one or more salts of the at least one organic crystalline compound.

14. The method of claim 13, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound and one or more salts of the at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound and one or more salts of the at least one organic crystalline compound, wherein the at least one organic crystalline compound and the one or more salts of the at least one organic crystalline compound comprise between about 10.0 weight percent and about 60.0 weight percent of the total weight of the solid pyrotechnic composition.

15. The method of claim 13, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound and one or more salts of the at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound and one or more salts of the at least one organic crystalline compound, wherein the at least one organic crystalline compound and the one or more salts of the at least one organic crystalline compound have a mean particle size not greater than about 30 microns.

16. The method of claim 13, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound and one or more salts of the at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound and one or more salts of the at least one organic crystalline compound, wherein the at least one organic crystalline compound and the one or more salts of the at least one organic crystalline compound have a mean particle size not greater than about 15 microns.

17. The method of claim 13, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound and one or more salts of the at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound and one or more salts of the at least one organic crystalline compound having a weight ratio of the at least one organic crystalline compound to the one or more salts of the at least one organic crystalline compound of at least 80:

20.

18. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound having a mean particle size not greater than about 30 microns.

19. The method of claim 1, wherein dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound comprises dry blending at least one nonhygroscopic polymeric binder with at least one organic crystalline compound having a mean particle size not greater than about 15 microns.

20. The method of claim 1, wherein slurrying the dry mixture in a suitable solvent to produce a wet mixture comprise slurrying the dry mixture in a solvent that dissolves or swells the at least one nonhygroscopic polymeric binder.

21. The method of claim 6, wherein slurrying the dry mixture in a suitable solvent to produce a wet mixture comprises slurrying the dry mixture in ethanol.

22. The method of claim 21, wherein slurrying the dry mixture in ethanol comprises slurrying the dry mixture in ethanol comprising about 26.25 weight percent of the total weight of the solid pyrotechnic composition.

23. The method of claim 7, wherein slurrying the dry mixture in a suitable solvent to produce a wet mixture comprises slurrying the dry mixture in ethyl acetate.

24. The method of claim 1, wherein combining the wet mixture with oxidizer particles to form a pyrotechnic composition comprises combining the wet mixture with oxidizer particles having a mean particle size of not greater than about 30 microns.

25. The method of claim 1, wherein combining the wet mixture with oxidizer particles to form a pyrotechnic composition comprises combining the wet mixture with oxidizer particles having a mean particle size ranging from about 5 microns to about 20 microns.

26. The method of claim 1, wherein combining the wet mixture with oxidizer particles to form a pyrotechnic composition comprises combining the wet mixture with oxidizer particles comprising between about 40.0 weight percent and about 90.0 weight percent of the total weight of the solid pyrotechnic composition.

27. The method of claim 1, wherein combining the wet mixture with oxidizer particles to form a pyrotechnic composition comprises combining the wet mixture with oxidizer particles comprising between about 65.0 weight percent and about 80.0 weight percent of the total weight of the solid pyrotechnic composition.

28. The method of claim 1, wherein combining the wet mixture with oxidizer particles to form a pyrotechnic composition comprises combining the wet mixture with oxidizer particles comprising at least one member selected from the group consisting of alkali metal nitrate and ammonium nitrate and at least one member selected from the group consisting of alkali metal perchlorate and ammonium perchlorate.

29. The method of claim 28, wherein combining the wet mixture with oxidizer particles comprising at least one member selected from the group consisting of alkali metal perchlorate and ammonium perchlorate comprises combining the wet mixture with at least one member selected from the group consisting of alkali metal perchlorate and ammonium perchlorate comprising between about 0.5 weight percent and about 30.0 weight percent of the total weight of the solid pyrotechnic composition.

30. The method of claim 28, wherein combining the wet mixture with oxidizer particles comprising at least one member selected from the group consisting of alkali metal perchlorate and ammonium perchlorate comprises combining the wet mixture with at least one member selected from the group consisting of alkali metal perchlorate and ammonium perchlorate comprising between about 5.0 weight percent and about 20.0 weight percent of the total weight of the solid pyrotechnic composition.

31. The method of claim 28, wherein combining the wet mixture with oxidizer particles comprising at least one member selected from the group consisting of alkali metal perchlorate and ammonium perchlorate comprises combining the wet mixture with potassium perchlorate.

32. The method of claim 28, wherein combining the wet mixture with oxidizer particles comprising at least one member selected from the group consisting of alkali metal nitrate and ammonium nitrate comprises combining the wet mixture with potassium nitrate.

33. The method of claim 32, wherein combining the wet mixture with potassium nitrate comprises combining the wet mixture with potassium nitrate ranging from about 50.0 weight percent to about 70.0 weight percent of the total weight of the solid pyrotechnic composition.

34. The method of claim 1, further comprising mixing the pyrotechnic composition in a suitable mixing device to evaporate at least a portion of the solvent.

35. The method of claim 34, wherein mixing the pyrotechnic composition in a suitable mixing device to evaporate at least a portion of the solvent comprises mixing the pyrotechnic composition in a suitable mixing device to obtain a mixed pyrotechnic composition comprising the solvent in a concentration of between about 8.0 weight percent and about 15.0 weight percent of the total weight of the solid pyrotechnic composition.

36. The method of claim 34, wherein mixing the pyrotechnic composition in a suitable mixing device to evaporate at least a portion of the solvent comprises mixing the pyrotechnic composition in a suitable mixing device to obtain a mixed pyrotechnic composition comprising the solvent in a concentration of between about 10.0 weight percent and about 13.0 weight percent of the total weight of the solid pyrotechnic composition.

37. The method of claim 20, further comprising mixing the pyrotechnic composition in a suitable mixing device to evaporate at least a portion of the solvent.

38. The method of claim 37, wherein mixing the pyrotechnic composition in a suitable mixing device to evaporate at least a portion of the solvent comprises mixing the pyrotechnic composition in a suitable mixing device to obtain a mixed pyrotechnic composition comprising the solvent in a concentration of between about 8.0 weight percent and about 15.0 weight percent of the total weight of the solid pyrotechnic composition.

39. The method of claim 37, wherein mixing the pyrotechnic composition in a suitable mixing device to evaporate at least a portion of the solvent comprises mixing the pyrotechnic composition in a suitable mixing device to obtain a mixed pyrotechnic composition comprising the solvent in a concentration of between about 10.0 weight percent and about 13.0 weight percent of the total weight of the solid pyrotechnic composition.

40. The method of claim 1, further comprising mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste.

41. The method of claim 40, wherein mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste comprises mixing the pyrotechnic composition in a twin-screw extruder.

42. The method of claim 40, wherein mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste comprises mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste comprising the solvent in a concentration of between about 8.0 weight percent and 15.0 weight percent of the total weight of the solid pyrotechnic composition.

43. The method of claim 40, wherein mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste comprises mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste comprising the solvent in a concentration of between about 10.0 weight percent and 13.0 weight percent of the total weight of the solid pyrotechnic composition.

44. The method of claim 20, further comprising mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste.

45. The method of claim 44, wherein mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste comprises mixing the pyrotechnic composition in a twin-screw extruder.

46. The method of claim 44, wherein mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste comprises mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste comprising the solvent in a concentration of between about 8.0 weight percent and 15.0 weight percent of the total weight of the solid pyrotechnic composition.

47. The method of claim 44, wherein mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste comprises mixing the pyrotechnic composition in a suitable mixing device to obtain a thick paste comprising the solvent in a concentration of between about 10.0 weight percent and 13.0 weight percent of the total weight of the solid pyrotechnic composition.

48. The method of claim 1, further comprising drying the pyrotechnic composition to obtain the solid pyrotechnic composition.

49. The method of claim 48, wherein drying the pyrotechnic composition to obtain the solid pyrotechnic composition comprises:

drying the pyrotechnic composition in a suitable drying device to form a dried pyrotechnic composition;

granulating the dried pyrotechnic composition to form a granulated pyrotechnic composition; and

pressing the granulated pyrotechnic composition into pellets.

50. The method of claim 49, wherein pressing the granulated pyrotechnic composition into pellets comprises pressing the granulated pyrotechnic composition into pellets having a bulk density of at least 90.0% of the theoretical maximum density.

51. The method of claim 49, wherein pressing the granulated pyrotechnic composition into pellets comprises pressing the granulated pyrotechnic composition into pellets having a bulk density of no more than 84.0% of the theoretical maximum density.

52. The method of claim 48, wherein drying the pyrotechnic composition to obtain the solid pyrotechnic composition comprises:

drying the pyrotechnic composition in a suitable drying device to form a dried pyrotechnic composition;

blending the dried pyrotechnic composition with a suitable processing aid to form a blended pyrotechnic composition;

granulating the blended pyrotechnic composition to form a granulated pyrotechnic composition; and

pressing the granulated pyrotechnic composition into pellets.

53. The method of claim 48, wherein drying the pyrotechnic composition to obtain the solid pyrotechnic composition comprises:

drying the pyrotechnic composition in a suitable drying device to form a dried pyrotechnic composition;

blending the dried pyrotechnic composition with a suitable processing aid to form a blended pyrotechnic composition;

granulating the blended pyrotechnic composition to form a granulated pyrotechnic composition;

polishing the granulated pyrotechnic composition; and

pressing the polished pyrotechnic composition into pellets.

54. The method of claim 52, wherein blending the dried pyrotechnic composition with a suitable processing aid comprises blending the dried pyrotechnic composition with calcium stearate.

55. The method of claim 52, wherein blending the dried pyrotechnic composition with a suitable processing aid comprises blending the dried pyrotechnic composition with graphite.

56. A solid pyrotechnic composition having a total weight, the solid pyrotechnic composition comprising:

oxidizer particles comprising between about 40.0 weight percent and about 90.0 weight percent of the total weight of the solid pyrotechnic composition;

organic crystalline particles comprising between about 10.0 weight percent and about 60.0 weight percent of the total weight of the solid pyrotechnic composition;

ethyl cellulose comprising between about 2.0 weight percent and about 10.0 weight percent of the total weight of the solid pyrotechnic composition; and

a dry lubricant comprising between about 0.5 weight percent and 2.0 weight percent of the total weight of the solid pyrotechnic composition.

57. The solid pyrotechnic composition of claim 56, wherein the oxidizer particles have a mean particle size of not greater than about 30 microns.

58. The solid pyrotechnic composition of claim 57, wherein the oxidizer particles have a mean particle size ranging from about 5 microns to about 20 microns.

59. The solid pyrotechnic composition of claim 56, wherein the oxidizer particles comprise between about 65.0 weight percent and about 80.0 weight percent of the total weight of the solid pyrotechnic composition.

60. The solid pyrotechnic composition of claim 56, wherein the oxidizer particles comprise at least one member selected from the group consisting of alkali metal nitrate and ammonium nitrate and at least one member selected from the group consisting of alkali metal perchlorate and ammonium perchlorate.

61. The solid pyrotechnic composition of claim 60, wherein the at least one member selected from the group consisting of alkali metal perchlorate and ammonium perchlorate comprises between about 0.5 weight percent and about 30.0 weight percent of the total weight of the solid pyrotechnic composition.

62. The solid pyrotechnic composition of claim 61, wherein the at least one member selected from the group consisting of alkali metal perchlorate and ammonium perchlorate comprises between about 5.0 weight percent and about 20.0 weight percent of the total weight of the solid pyrotechnic composition.

63. The solid pyrotechnic composition of claim 60, wherein the oxidizer particles comprise potassium perchlorate.

64. The solid pyrotechnic composition of claim 60, wherein the oxidizer particles comprise potassium nitrate.

65. The solid pyrotechnic composition of claim 64, wherein the potassium nitrate comprises from about 5.0 weight percent to about 20.0 weight percent of the total weight of the solid pyrotechnic composition.

66. The solid pyrotechnic composition of claim 56, further comprising one or more salts of the organic crystalline particles, wherein the organic crystalline particles and the one or more salts of the organic crystalline particles comprise between about 10.0 weight percent and about 60.0 weight percent of the total weight of the solid pyrotechnic composition.

67. The solid pyrotechnic composition of claim 56, wherein the organic crystalline particles comprise at least one member selected from the group consisting of phenolphthalein and an organic crystalline compound derived from a reaction between a phenolic compound and phthalic anhydride.

68. The solid pyrotechnic composition of claim 56, wherein the organic crystalline particles comprise phenolphthalein.

69. The solid pyrotechnic composition of claim 68, wherein phenolphthalein comprises between about 13.0 weight percent and 22.0 weight percent of the total weight of the solid pyrotechnic composition.

70. The solid pyrotechnic composition of claim 56, wherein the organic crystalline particles have a mean particle size not greater than about 30 microns.

71. The solid pyrotechnic composition of claim 70, wherein the organic crystalline particles have a mean particle size not greater than about 15 microns.

72. The solid pyrotechnic composition of claim 66, wherein the organic crystalline particles and the one or more salts of the organic crystalline particles have a mean particle size not greater than about 30 microns.

73. The solid pyrotechnic composition of claim 72, wherein the organic crystalline particles have a mean particle size not greater than about 15 microns.

74. The solid pyrotechnic composition of claim 66, wherein a weight ratio of the organic crystalline particles to the one or more salts of the organic crystalline particles is at least 80:

20.

75. The solid pyrotechnic composition of claim 56, wherein the ethyl cellulose comprises about 3.0 weight percent of the total weight of the solid pyrotechnic composition.

76. The solid pyrotechnic composition of claim 56, wherein the solid pyrotechnic composition is substantially free of sulfur and charcoal.

77. The solid pyrotechnic composition of claim 56, wherein the solid pyrotechnic composition is substantially free of boron.

78. The solid pyrotechnic composition of claim 56, wherein the solid pyrotechnic composition has a moisture uptake of not greater than 0.25 weight percent at 75.0 percent relative humidity at a temperature of 21.1°

C. over a period of 24 hours.

79. The solid pyrotechnic composition of claim 56, wherein the solid pyrotechnic composition is formulated to have, upon ignition, a theoretical flame temperature not greater than about 2300K.

80. The solid pyrotechnic composition of claim 56, wherein the solid pyrotechnic composition is formulated to have, upon ignition, a theoretical flame temperature between about 1750K and 2300K.