Non-phthalate propellants

Abstract

The invention relates to Insensitive Munition (IM) energetic materials particularly non-phthalate IM propellant compositions. An energetic composition suitable for use as a propellant comprises the following components in the following relative proportions: component A; from 60% to 90% by weight of a highly energetic filler comprising at least one nitramine compound; and component B: from 5% to 20% by weight of a binder, component C: from and 3% to 15% of a plasticiser wherein the plasticiser comprises formula (A) of from 1% to 9% by weight, wherein Formula (A) is a diester plasticiser of
R.sub.1OC(O)R.sub.3C(O)OR.sub.2,Formula (A) wherein R.sub.1, R.sub.2, and R.sub.3 are independently selected from C.sub.3 to C.sub.10 alkyl or alkenyl. the percentages by weight of components A, B and C, together with minor additives, if any, adding to 100%.

Claims

1. A propellant composition comprising the following components in the following relative proportions: component A: from 55% to 75% by weight of a highly energetic filler comprising at least one nitramine compound, wherein component A further comprises Nitrotriazolone (NTO), Hexanitrostilbene (HNS), Nitroguanidine (Picrite), Triaminotrinitrobenzene (TATB), Guarnylureadinitramide (FOX-12) or 1,1-diamino 2,2-dinitro ethylene (FOX-7); component B: from 5% to 15% by weight of a non-energetic binder selected from one or more ethylene-vinyl acetate compounds, and from 5% to 7% by weight of an energetic binder; and component C: from 8% to 10% of a plasticiser wherein the plasticiser contains only a compound of Formula (A), wherein Formula (A) is R.sub.1OC(O)R.sub.3C(O)OR.sub.2, and R.sub.1, R.sub.2, and R.sub.3 are independently selected from C.sub.1 to C.sub.10 alkyl or alkenyl, the percentages by weight of components A, B and C, together with minor additives, if any, adding to 100%.

2. The propellant composition of claim 1 wherein component A is one or more of RDX (cyclo-1,3,5-trimethylene, 2,4,6-trinitramine, cyclonite or Hexagen), HMX (cyclo-1,3,5,7-tetramethylene-2,4,6,8-tetranitramine or Octogen), TATND (tetranitro-tetraminodecalin), TAGN, aromatic nitramines, nitrate esters inorganic perchlorates and inorganic nitrates.

3. The propellant composition of claim 1, wherein the plasticiser is selected from di Octyl adipate (DOA) and Di Octyl Sebacate (DOS).

4. A gun propellant comprising sticks or granules comprising a composition according to claim 1.

5. The propellant composition of claim 1 wherein component A comprises a metallic fuel.

6. The propellant composition of claim 1 wherein R.sub.1, R.sub.2, and R.sub.3 are independently selected from C.sub.3 to C.sub.10 alkyl or alkenyl.

7. The propellant composition of claim 1 wherein component A comprises an aromatic nitramine selected from tetryl and ethylene dinitramine.

8. The propellant composition of claim 1 wherein component A further comprises a nitrate ester selected from nitroglycerine (glycerol trinitrate), butane triol trinitrate and pentaerythrital tetranitrate.

9. The propellant composition of claim 1, wherein the plasticiser is selected from sebacic, adipic and maleic homologues of dialkyl esters.

10. The gun propellant of claim 4 exhibiting a propellant force in the range of 820 kJ/kg to 1250 kJ/kg.

11. The propellant composition of claim 5 wherein the metallic fuel comprises aluminum particles.

12. The propellant composition of claim 1 further comprising a stabilizer.

13. The propellant composition of claim 12 comprising a ballistic modifier and a flash suppressant.

14. The propellant composition of claim 3, wherein the plasticiser comprises Di Octyl Sebacate (DOS).

15. The propellant composition of claim 9, wherein the plasticiser comprises sebacic and maleic homologues of dialkyl esters.

16. An insensitive munition propellant composition consisting essentially of: component A: from greater than 60% by weight of a highly energetic filler, the energetic filler comprising at least one nitramine compound and one or more of Nitrotriazolone (NTO), Hexanitrostilbene (HNS), Nitroguanidine (Picrite), Triaminotrinitrobenzene (TATB), Guarnylureadinitramide (FOX-12) and 1,1-diamino 2,2-dinitro ethylene (FOX-7); component B: from 5% to 7% by weight of a non-energetic binder selected from one or more ethylene-vinyl acetate compounds, and from 8% to 10% by weight of an energetic binder; and component C: from 5% to 10% of a plasticiser, wherein the plasticiser consists of a compound having a formula of R.sub.1OC(O)R.sub.3C(O)OR.sub.2, wherein R.sub.1, R.sub.2, and R.sub.3 are independently selected from C.sub.1 to C.sub.10 alkyl or alkenyl groups, the percentages by weight of components A, B and C, together with minor additives, if any, adding to 100%.

Description

(1) Exemplary embodiments of the device in accordance with the invention will now be described with reference to the accompanying drawings in which:

(2) FIG. 1 shows a three-dimensional representation of a bundle of propellant sticks

(3) Turning to FIG. 1 there is provided an end portion of a bundle 1 of a plurality of propellant sticks 2. A resilient ligature 3 has been wound around the plurality of sticks 2 three times using a tying machine (not shown). The securing of the ligature 3 may be afforded by using a knot and subsequently cutting the ligature 3. Further ligatures may be applied to other distinct circumferences and in fact it may be preferred to have at least two ligatures applied at distinct circumferences in order to prevent the propellant sticks 2 from splaying.