US2982639A - Explosive compositions - Google Patents

Description

2,982,639 & Patented May 2, 1961 EXPLOSIVE COMPOSITIONS William A. Gey, China Lake, Calif., assignor to the United States of America as represented by the Sec- .retary of the Navy The invention describedherein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the paymentof any royalties thereon or therefor.

This invention relates to new explosive compositions; more particularly, it relates to explosive compositions having decreased sensitivity to mechanical shock and which are not sticky.

An objective in the production of high explosives is an explosive which is relatively insensitive to detonation by mechanical shock and highly sensitive to detonation by explosive shock. A number of explosives which have high explosive efiiciency are unsuitable for military or commercial use because their sensitivity to mechanical shock makes handling of them extremely hazardous. An expedient which has been used to overcome this difficulty in a number of explosive compositions is the incorporation therein of an additive which reduces the sensitivity of the explosive to mechanical shock. For example, paraflin hydrocarbons have been added to such explosives as tetranitromethane; nitro aromatic hydrocarbons have been added to blasting gelatin; and cellulose acetate has been added to nitroglycerin for the above purpose. A difiiculty attendant to the incorporation of additives in explosive compositions is the fact that ordinarily certain desirable qualities such as brisance, density and others are sacrificed. Accordingly, this procedure ordinarily results in a compromise between various properties of the explosive.

Petroleum waxes have been used in the past as additives to such high explosives as cycle trimethylene trinitramine, known in the art as RDX. Although these additives reduce the sensitivity of the explosive to mechanical shock, they also produce a final composition which is excessively sticky. This latter characteristic makes processing difiicult. In addition, their incorporation in the explosive results in a lowering of its overall density, thus resulting in a less compact explosive with resultant loss of explosive power.

It is, therefore, an object of this "invention to provide high explosive compositions having reduced sensitivity to detonation by mechanical shock.

It is another object of this invention to provide high explosive compositions in which sensitivity to-mechanical shock has been lowered by the addition of additives to. high explosives which do not appreciably decrease the explosive power of the explosive and which produce final compositions having higher densities than prior compositions.

It is still another object of this invention to provide high explosive compositions which are not sticky or tacky and can bereadily processed.

It is a still further object of this invention to provide high explosive compositions which have good storage characteristics.

It is a further object of this invention to provide a 2 high explosive composition which is relatively simple and inexpensive to make.

It has been found that the above and other objects can be accomplished and the enumerated difliculties overcome .by the incorporation in high explosives such as cyclotrimethylene trinitramine of ethers of linear methylene nitramines ormixtures thereof of the structure wherein R is selected from the group consisting of hydrogen, alkyl or alkoxy, =R 'is alkoxy and x is an integer. The above compounds are, prepared by the reaction of the appropriate alcohol with NSX (l-nitroXy-2,4,6- trinitro-2,4,6-triazaheptane), ATX (1,7 dinitroxy-2,4,6- trinitro-2,4,6-triazaheptane), 1-nitroxy-2,4,6-trinitro-2,4,6- triazadecane, 1,9-dinitroxy-2,4,6,8-tetranitro-2,4,6,8-tetrazanonane or other appropriate linear methylene nitramines, as disclosed in the co-pending application entitled Alkyl Ethers of William A. Gey and Robert W. Van Dolah, Serial No. 333,623, filed January 2, 1953, in the United States Patent Office. The additives which have been found most eflfective are the propyl,'butyl, amyl, hexyl and heptyl ethers of NSX and the butyl, amyl, hexyl, heptyl and octyl ethers of ATX.

It has been found that the incorporation of the above type additives in RDX and other explosives increases the density of the composition Without appreciable lowering of its explosive power or its sensitivity to explosive shock. In contrast to prior additives, such as petroleum waxes, the final product is not sticky or tacky so that handling ease is not affected.

The following examples are illustrative of the invention but are not intended to be limiting thereof.

Example 1 22 grams of RDX were added to a solution of 2.25 grams of the heptyl ether prepared from NSX in 30 cc. of toluene to which had been added .1 gram of Span 80. The mixture was slurried in 300 cc. of Water and heated under agitation until the toluene was steam distilled. The mixture was cooled under agitation to 25 C., filtered and dried. The resulting composition had a density of 1.625 and an impact sensitivity about that of commercial composition A.

The procedure of Example 1 was repeated using the hexyl ether of NSX. The product formed from a mixture with this ether had a density of 1.614 and an impact sensitivity about that of commercial composition A.

Example 2 4.5 grams of commercial RDX were suspended in 10 cc. of methylene chloride containing 0.5 gram of the 1,7-di-n-hexyl ether prepared from ATX. The methylene chloride was removed by boiling in a hot water bath until a paste viscosity remained, then evaporating with a vacuum pump. The density of the product when pelleted at 15,000 psi. was 1.645 gm. per cc. The impact sensitivity of the compound was approximately equal to that of commercialcomposition A (91% RDX-9% petroleum wax).

Example 3 4.50 gms. of RDX were slurried in a solution containing 0.50 gram of the 1,7-di-n-octyl ether prepared from ATX in 15 cc. of methylene chloride. Most of the methylene chloride was removed by heating in a hot water bath -(-75 C.) until a thick paste remained. The suspension was stirred continuously. The remaining methylene chloride was removed by vacuum. The density of the product was 1.628 gms. per cc. Its impact sensitivity was slightly less than that of commercial composition A.

Example 4 A mixture of 18.2 grams of RDX, 1.8 grams of the 1,7-di-n-amyl ether prepared from ATX and .1 gram of Span were added to 10 grams of hexane, the resulting mixture warmed and 100 cc. of water added. The hexane was boiled off with agitation to hold the emulsion. The mixture was cooled to 30 C., filtered and Washed with .50 cc. of water. After air drying for three hours and vacuum desiccation for 40 hours, 19.8 grams of product were obtained. Microscopic examination at 75 indicated a complete, homogeneous covering of the particles. The compound was found to have an impact sensitivity of 38. (50% shots with a 2 kilo gram weight at 38 centimeters). The compound was found to. have a ballistic mortar value of 138.1% that of TNT. This compares to a ballistic mortar value of 130% that of TNT for commercial Composition A. The heat of explosion of the compound was 1230 calories per gram. Its density pressed at 15,000 p.s.i. was 1.661 gms. per cc.

Example 5 A mixture containing of the di-n-hexyl ether prepared from 1,9 dinitroxy 2,4,6,8-tetranitro-2,4,6,8- tetrazanonane and 90% RDX by weight was made and tested. The explosive mixture was found to have a density of 1.592 and an impact sensitivity of 39 using a 2 kg. wt. This sensitivity is about that of Composition A.

The range of percentage composition of the mixtures is not critical and can be varied, depending upon the desired characteristics of the product, such as sensitivity to mechanical and explosive shock, brisance, density, and other. Obviously, mixtures of the ethers may be used as additives. Although compositions containing cyclotrimethylene trinitramine have been used to illustrate the invention other high explosives may be used.

The explosive compositions of the invention are relatively insensitive to mechanical shock and have higher densities than presently available compositions and, therefore, greater explosive power than compositions modified with conventional additives. None of the compositions are sticky or tacky so that they can be readily processed.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. Explosive compositions consisting essentially of approximately 90% by weight of cyclotrimethylene trinitramine and the balance of ethers of the structure drogen, lower alkyl, and lower alkoxy, R is lower alkoxy and x is one of the integers 3 and 4, with the limitations that when R is a hydrogen atom the alkoxy group represented by R has more than 2 carbon atoms and when R and R are both alkoxy each of these groups has more than 2 carbon atoms.

2. Explosive compositions consisting essentially of approximately by Weight of cyclotrimethylene trinitrarnine, and the balance of ether of the formula 3. Explosive compositions consisting essentially of approximately 90% by Weight of cyclotrimethylene trinitramine and the balance of ether of the formula I l H H H 4. Explosive compositions consisting essentially of approximately 90% by Weight of cyclotrimethylene trinitramine and the balance of ether of the formula 5. Explosive compositions consisting essentially of approximately 90% by weight of cyclotrimethylene trinitramine and the balance of ether of the formula NO: H NO; 11 NO: H

6. Explosive compositions consisting essentially of approximately 90% by weight of cyclotrimethylene trinitramine and the balance of ether of the formula References Cited in the file of this patent UNITED STATES PATENTS 2,548,880 Fassnatcht et al. Apr. 17, 1951 FOREIGN PATENTS 469,721 Germany Dec. 20, 1928 543,174 Germany Feb. 2, 1932 123,252 Australia Jan. 23, 1947

Claims (1)

1. EXPLOSIVE COMPOSITIONS CONSISTING ESSENTIALLY OF APPROXIMATELY 90% BY WEIGHT OF CYCLOTRIMETHYLENE TRINITRAMINE AND THE BALANCE OF ETHERS OF THE STRUCTURE