Low vulnerability booster charge caseless ammunition

• US 4,091,729 A
• Filed: 03/07/1977
• Issued: 05/30/1978
• Est. Priority Date: 03/07/1977
• Status: Expired due to Term

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Peterson, John A., Bell, Frank H., Munson, William O., McDonald, Michael S., Borcherding, Ronald L.
• Primary Examiner(s): Miller, Edward A.
• Application Number:
  US05/775,140
• Time in Patent Office: 449 Days
• Field of Search: 102/38 R, 102/38 CC, 102/DIG. 1, 102/103, 149/11, 149/19.4, 149/92
• US Class Current: 102/431
• CPC Class Codes: C06B 45/22 the coating containing an organic compound
• CPC Class Codes: Y10S 102/70 Combustilbe cartridge

Abstract

A low vulnerability booster charge comprising single, fairly large crystalsf 1,3,5,7-tetramethylenetetranitramine (HMX) or 1,3,5,-trimethylenetrinitramine (RDX) about 160 microns diameter coated with a polyurethane cement which comprises about 15 weight percent of the entire booster charge.

Claims

1. In a gun ammunition cartridge including a cylindrical, caseless propellant charge, a projectile bonded into one end thereof, and a primer cap bonded into the other end, a cavity being provided in the propellant charge adjacent the primer cap, the improvement comprising:

a particulate booster charge in the cavity wherein each particle comprises a single crystal ranging from 100 to 500 micron weight mean diameter selected from the group consisting of 1,3,5,7-tetramethylenetetranitramine and 1,3,5-trimethylenetrinitramine and a cured polyurethane coating on each crystal comprising about 30 to 55 weight % diisocyanate bitolylene, about 40 to 65 weight % hydroxyl-terminated polyethylene oxide, and about 5 to 15 weight % trimethylol propane.

2. The cartridge of claim 1 wherein the crystals of the booster charge are 1,3,5,7-tetramethylenetetranitramine.

3. The cartridge of claim 1 wherein the crystals of the booster charge are 1,3,5-trimethylenetrinitramine.

4. The cartridge of claim 1 wherein the polyurethane coating comprises about 15% by weight of the particulate booster charge.

5. The cartridge of claim 1 wherein the crystals of the booster charge are any proportions of 1,3,5,7-tetramethylenetetranitramine and 1,3,5-trimethylenetrinitramine.

6. The cartridge of claim 1 wherein said polyurethane coating comprises 37.58 weight % diisocyanate bitrolylene, 52.52 weight % hydroxyl-terminated polyethylene oxide and 9.80 weight % trimethylol propane.

7. A particulate, low-vulnerability, booster propellant for gun ammunition wherein each particle comprises:

a single crystal ranging from 100 to 500 micron weight mean diameter selected from the group consisting of 1,3,5,7-tetranethylenetetranitramine and 1,3,5-trimethylenetrinitramine; and

a cured polyurethane coat on each said crystal comprising about 30 to 55 weight % diisocyanate bitolylene, about 40 to 65 weight % hydroxylterminated polyethylene oxide, and about 5 to 15 weight % trimethylol propane.

8. The booster of claim 7 wherein the crystals thereof are 1,3,5,7-tetranethylenetetranitramine.

9. The booster of claim 7 wherein the crystals thereof are 1,3,5-trimethylenetrinitramine.

10. The booster of claim 7 wherein said polyurethane coating comprises about 15% by weight of the particulate booster charge.

11. The booster of claim 7 wherein the crystals thereof are any proportions of 1,3,5,7-tetramethylenetetranitramine and 1,3,5-trimethylenetrinitramine.

12. The booster propellant as described in claim 7 having thermal stability and ignition values as presented in Table II of the specification.