WO2004089853A1 - Method for producing insensitive hexogene - Google Patents

Abstract

The invention relates to a method for producing insensitive hexogene containing a 5 % part of octogen, achieving a behaviour which is insensitive to thermal loads (fast cook-off).

Description

 Process for the production of insensitive hexogen

The invention relates to a method for producing insensitive hexogen.

A new type of hexogen (insensitive RDX) has a crystal structure that is close to the ideal level. Whose shock wave sensitive and the thermal

Sensitivity is lower than with the previously known hexogen as well as with the known standard improved types of the hexogen. However, the aforementioned pure hexogens do not meet the conditions for thermal immunity according to the technical delivery conditions of the Federal Office for Defense Technology and Procurement in Germany, TL 1376-0800, STANAG

4170. These delivery conditions require that an explosive enclosed in a container, such as a projectile body, does not tear open the container when it is bombarded or subjected to thermal effects. Only the burning off of the explosive is permitted as the maximum reaction, the cylindrical container remaining completely. Cracks in the container wall must not occur.

The invention is based on the object of proposing a method for producing an insensitive hexogen which fulfills the conditions mentioned.

The invention solves this problem in accordance with the method claims.

According to the invention, the hexogen is surprisingly less sensitive overall, but more powerful. By adding octogen to the pure, insensitive hexogen of at least 4% it is achieved that due to the phase change of the octogen from about a temperature of about 190 ° C due to the decreasing density, there is an abrupt volume increase and the container at about a temperature of 200 ° C is opened by pressing off the front cover.

The threaded connections are loosened. Gases can escape. As a further maximum consequence, the explosives burn off quietly. The explosive is prevented from reacting strongly.

The effect according to the invention begins with an octogen fraction of 4%. The optimal economic and technical share is 5%.

Definition: DOA Acycl. Dicafbonsäureester

HYTEMP® registered trademark of ZEON Chemicals L.P., 4100 Beils Lane, Louseville, Kennrucky 40211

The following crystal ratio of hexogen and octogen is selected to carry out the paste method or the sfurry method.

95 wt% hexogen and 5 wt% octogen

According to an 8% binder system, the following amounts are used:

87% by weight hexogen, 4.5% by weight octogen, 6% by weight DOA, 2% by weight HYTEMP®

For a 4% binder system, the amounts are:

51.5% by weight hexogen, 4.5% by weight octogen, 3% by weight DOA, 1% by weight of HYTEMP®

In the case of both mixtures, the bandwidth for the octogen is 1.0% by weight, i.e. H. The optimized aim of the invention is achieved with an octogen content of 4.5-5.5% by weight, based on the binder systems mentioned.

The process steps in the paste process are as follows for the two mixtures:

1. The crystals of hexogen and octogen contained in the binder components are stirred together with a solvent mixture of ethyl acetate and acetone in an evacuated mixer at 40 ° C. for about 1 hour.

2. The solvent mixture is then suctioned off under

Supply of heat at a constant 40 ° C until a vacuum of about 240 mbar is reached.

3. Then another evacuation is carried out with the addition of heat at a temperature of 60 to 70 ° C until complete evacuation at <1 mbar.

The process steps according to the slurry method are as follows for the two mixtures:

1. The crystals of hexogen and octogen are placed in a mixer with water at ambient air pressure and brought to a water temperature of 70 ° C.

2. During the stirring process, DOA and HYTEMP® dissolved in ethyl acetate are dropped into the mixer until the turbidity of the water is eliminated. After that is done

3. removing the water by filtering and evaporating. The advantage of the paste process is that a euteutic of hexogen and octogen crystals is absolutely avoided. Rather, the crystals are separated from one another by the binder system.

It is also advantageous that the density is more than 98% of the TMD (Theoretical Maximum Density) at comparatively low pressing pressures.

Finally, when the hexogen produced by the paste method is pressed under vacuum, considerable cost savings are achieved in that the pressing pressures are 30 to 50% of the previous pressing pressures. With a charge cross section of 100 mm according to the prior art, a pressing pressure of 1.5 kbar is customary. According to the invention, with such a charge diameter, only a pressing pressure of about 0.5 kbar is required. There is therefore no need for heavy and therefore expensive pressing tools. Rather, thin-walled pressing tools are sufficient. If the explosive charge casing is appropriately dimensioned, no lateral support for the explosive charge casing is required.

Another significant advantage is that the explosive charge produced by the paste process can be almost completely detached from the ammunition and can then be used almost completely again, and without complex preparation processes. Because with standard explosive charges based on the prior art based on hexogen, the crystal structure of hexogen and octogen is destroyed when the explosive charge is mechanically removed and the pressing behavior is thus changed.

Another advantage of the paste process is the reusability of the solvent or its complete recyclability.

In the paste process, microstructure defects on the crystal surfaces of the explosive crystals are smoothed out. My crystals otherwise adhering to the surface of the crystals are also removed as a result of the action of solvents.

Claims

Patent claims 1. Process for the production of insensitive hexogen in a 4% by weight or 8% by weight binder system consisting of DOA and HYTEMP®: 1. 87.5 / 91.5% by weight of hexogen and 4.5% by weight of octogen are stirred in an evacuated mixer with a solvent mixture of ethyl acetate and acetone at 40 ° C. for about 1 hour. 2. Aspirate the solvent mixture at a constant 40 ° C until a vacuum of about 240 mbar is reached. 3. Complete evacuation to <1 mbar at 60 to 70 ° C. 2. Insensitive hexogen, characterized in that when using pure hexogen, the explosive contains at least 4% octogen.