POLYMERISABLE BINDER

Abstract

The invention relates to Polymerisable Binders, and Insensitive Munition (IM) energetic materials particularly to non-phthalate IM propellant compositions which are printed by a UV curing additive layer manufacture process. invention there is provided an additive layer deposable energetic composition suitable for use as a propellant comprising the following components in the following relative proportions: component A; from 60% to 95% 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, wherein the binder contains component D a UV curable binder in the range of from 3% to 12% by total weight of the formulation, at least one UV photoinitiator, component C: from 1% to 15% of a plasticiser, the percentages by weight of components A, B, D and C, together with minor additives, if any, adding to 100%.

Claims

1. An additive layer deposable energetic composition suitable for use as a propellant and comprising the following components in the following relative proportions: component A, from 60% to 95% by weight of the composition, wherein component A is an energetic filler comprising at least one nitramine compound; component B, from 5% to 20% by weight of the composition, wherein component B is a binder; component C, from 1% to 15% by weight of the composition, wherein component C is a plasticiser; and component D, from 3% to 12% by weight of the composition, wherein component D includes a UV curable binder and at least one UV photoinitiator; the percentages by weight of components A, B, C and D, together with minor additives, if any, adding to 100%.

2. The composition according to claim 1, wherein: component A comprises 60% to 75% by weight of the composition, and component B comprises 8% to 16% by weight of the composition, and component C comprises 5% to 10% by weight of the composition, and component D comprises 4% to 10% by weight of the composition, and the percentages adding to 100%.

3. The composition according to claim 1, wherein the UV curable binder is a UV curable epoxide, a UV curable urethane, a UV curable vinyl, a UV curable epoxy, a UV curable polyether, a UV curable polyester, or a UV curable acrylate.

4. The composition according to claim 1, wherein the at least one UV photoinitiator is ionic or free radical.

5. The composition according to claim 1, wherein the cure time of the component D is less than 60 seconds.

6. The composition according to claim 5, wherein the cure time is instantaneous.

7. The composition according to claim 1, wherein component A is 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, Octogen), or TATND (tetranitro-tetraminodecalin), or mixtures thereof.

8. The composition according to claim 1, wherein component A comprises Nitrotriazolone (NTO), Hexanitrostilbene (HNS), Nitroguanidine (Picrite), Triaminotrinitrobenzene (TATB), Guarnylureadinitramide (FOX-12), or 1,1-diamino 2,2-dinitro ethylene (FOX-7).

9. The composition according to claim 1, wherein the plasticiser comprises R.sub.1—OC(O)—R.sub.3—C(O)O—R.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, alkenyl.

10. The composition according to claim 1, wherein the plasticiser is selected from di Octyl adipate(DOA), Di Octyl Sebacate (DOS), and dialkyl esters comprising sebacic adipic and maleic homologues.

11. The composition according to claim 1, wherein the component B binder is selected from a non-energetic binder and an energetic binder.

12. A method of additive layer manufacturing a binder cured composition according to claim 1, the method comprising: a) forming an uncured admixture of components A, B, C, and D; b) applying, by an energy source in the form of a UV or e-beam source, to a first portion of a surface of the uncured admixture, sufficient to cause the formation of a cured admixture of said first portion; c) moving the energy source to progressively form a layer of cured admixture; and d) repeating a) to c) as required whereby to form the cured admixture in a 3D structure.

13. The method of according to claim 12, comprising, after b, causing a second portion of the surface of said uncured admixture to be not subjected to the energy source, such that said second portion contains no cured admixture.

14. A method of additive layer manufacturing a binder cured composition according to claim 1, comprising: a) forming an uncured admixture of components A, B, C, and D, to be provided at a nozzle; b) deposing from said nozzle a first aliquot of said uncured admixture; c) applying, by an energy source in the form of a UV or e-beam source, to said first aliquot of said uncured admixture to form a cured first aliquot; d) moving the nozzle to progressively form a second uncured aliquot, applying, by an energy source in the form of a UV or e-beam source, to said second aliquot of said uncured admixture to form a cured second aliquot; and e) repeating a) to d) as required whereby to furnish the cured admixture in a 3D structure.

15. An additive layer deposable energetic composition suitable for use as a propellant, the composition comprising: a highly energetic filler, a UV curable binder, a plasticiser, and at least one UV photoinitiator.

16. The composition according to claim 15, comprising: an insensitive munition (IM) energetic filler.

17. The composition according to claim 15, wherein the at least one photoinitiator is ionic or free radical.

18. The composition according to claim 15, wherein the highly energetic filler comprises 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, Octogen), or TATND (tetranitro-tetraminodecalin), or mixtures thereof.

19. The composition according to claim 15, wherein the plasticiser comprises di Octyl adipate(DOA), Di Octyl Sebacate (DOS), or a dialkyl ester comprising sebacic adipic and/or maleic homologues.

20. The composition according to claim 1, wherein the energetic filler of component A comprises TAGN, an aromatic nitramine, a nitrate ester, an inorganic perchlorate, a nitrate, or a metallic fuel, or mixtures thereof.

Description

EXPERIMENTAL

[0038] The formulation from table 1 was prepared, to 100 g of LOVA propellant (RDX, Nitrocellulose, butyl NENA, DOS and carbamate), was added 10 ml of BDT1015 binder and 0.1 ml photoinitiator (2,4-Diethylthioxanthone). A layer of 2 ml was deposed via a syringe to form a deposited line on a substrate. The deposited line was irradiated with a UV lamp (395 nm), the UV binder cured to provide a cured polymerised line.