Ink jet printing and patterning of explosive materials

Patent metadata

Field	Value
Publication number	US-9296241-B1
Application number	US-201314078827-A
Country	US
Kind code	B1
Filing date	Nov 13, 2013
Priority date	Dec 18, 2009
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

A method of forming a very small, i.e. microliter, finely detailed explosive train for the ignition of energetic munitions—which train is formed by ink jetting picoliter volume droplets of an explosive ink onto the substrate; which explosive ink is a pure liquid that will not clog the ink jet printer. The explosive ink being a solution composed of a secondary organic explosive solute, a polymeric binder solute, and a polar aprotic organic solvent. Where the ink jet printer is a commercial piezoelectric type, drop-on-demand, ink jet printer capable of precisely delivering the subject picoliter volume droplets. And, which printer is capable of heating said substrate to an elevated temperature to more rapidly evaporate the solvent, leaving the desired, finely detailed, efficacious, crystalline explosive train.

First claim

What is claimed is:

1. A method of patterning an explosive train on a substrate comprising the steps of:
formulating an explosive liquid ink solution consisting essentially of a secondary organic explosive material, and a polymeric binder, dissolved in a polar aprotic solvent;
wherein said explosive liquid ink solution is free of water and free of any protic polar solvent;
ink jet printing said explosive liquid ink solution using a piezoelectric type, drop-on-demand ink jet printer to form the pattern of the explosive train on a substrate.

2. The method of patterning an explosive train of claim 1 , wherein said ink jet printing deposits ink droplets upon the substrate, each droplet producing a generally disc-shape upon the substrate after solvent evaporation.

3. The method of patterning an explosive train of claim 2 , wherein said disc shaped elements are about 20 to about 50 microns in diameter.

4. A method of forming an explosive train on a substrate comprising the steps of:
formulating an explosive liquid ink solution consisting essentially of a secondary organic explosive material, and a polymeric binder, dissolved in a polar aprotic organic solvent;
wherein said explosive liquid ink solution is free of water and free of any protic polar solvent;
ink jet printing said explosive liquid ink using a piezoelectric type, drop-on-demand ink jet printer on the substrate to form the pattern of the explosive train; and
repeating said ink jet printing of said pattern on top of the prior pattern, thereby forming layers to build up the thickness of said pattern, thereby forming the explosive train.

5. The method of forming an explosive train of claim 4 , wherein said polar aprotic organic solvent is dimethylformamide.

6. The method of forming an explosive train of claim 4 , wherein the substrate is heated to an elevated temperature of at least about 30 degrees centigrade during said ink jet printing.

7. The method of forming an explosive train of claim 4 , wherein the substrate is heated to an elevated temperature of at least about 60 degrees centigrade.

8. The method of forming an explosive train of claim 4 , wherein the layers are from about 0.5 to about 1.0 microns thick.

9. The method of forming an explosive train of claim 4 , wherein the layers are built up to a thickness of up to about 100 microns.

10. The method of forming an explosive train of claim 4 , wherein said substrate is selected from the group consisting of a metallic, ceramic, dielectric, polymeric, and organic material.

11. The method of forming an explosive train of claim 1 , wherein said secondary organic explosive material is selected from the group consisting of cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), cyclotetramethylene tetranitramine (HMX), and pentaerythritol tetranitrate (PETN).

12. The method of forming an explosive train of claim 1 , wherein said polar aprotic solvent is selected from the group consisting of dimethylformamide (DMF), dimethyl sulfoxide (DMSO), dioxane, hexamethylphosphorotriamide, tetrahydrofuran, dichloromethane (DCM), butyl acetate, acetone, acetonitrile (MeCN) or a mixture thereof.

13. A method of patterning an explosive train on a substrate comprising the steps of:
formulating an explosive liquid ink solution consisting essentially of cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) and a binder wherein said binder is polyvinyl acetate (PVAC) or cellulose acetate butyrate (CAB), and wherein said RDX and binder is dissolved in dimethylformamide (DMF);
printing said explosive liquid ink solution using a piezoelectric type, drop-on-demand ink jet printer to form a pattern of the explosive train on a substrate and precipitating the RDX and binder on said substrate.

14. The method of claim 13 wherein the explosive liquid ink solution contains about 20 to about 30 weight percent of RDX and about 0.01 to about 10 weight percent of binder.

Assignees

• Ihnen Andrew C
• Lee Woo Young
• Fuchs Brian
• Petrock Anne Marie
• Stec Iii Daniel
• Us Army

Inventors

• Ihnen Andrew C
• Lee Woo Young
• Fuchs Brian
• Petrock Anne Marie
• Stec Iii Daniel

Classifications

• B41M3/006 Primary

  Patterns of chemical products used for a specific purpose, e.g. pesticides, perfumes, adhesive patterns; use of microencapsulated material; Printing on smoking articles · CPC title

• C06B45/00

  Compositions or products which are defined by structure or arrangement of component of product (explosive charges of particular form or shape F42B1/00, F42B3/00) · CPC title

• C06B21/0033

  Shaping the mixture · CPC title

• C09D11/30

  Inkjet printing inks · CPC title

• C09D11/36

  based on non-aqueous solvents · CPC title