WO1998016485A1

WO1998016485A1 - Explosive formulations

Info

Publication number: WO1998016485A1
Application number: PCT/US1997/008332
Authority: WO
Inventors: Ralph Edward Dawson
Original assignee: Eastman Chemical Company
Priority date: 1996-10-15
Filing date: 1997-05-02
Publication date: 1998-04-23
Also published as: JP2001501159A; EP0932591A1; AU3129097A; NO991771D0; CA2268768A1; IL128589A0; NO991771L

Abstract

Composition comprising 1,3,3 trinitroazetidine (TNAZ) coated with a shock sensitivity reducing agent whereby the shock sensitivity of the composition is reduced a statistically significant amount.

Description

EXPLOSIVE FORMULATIONS

BACKGROUND OF INVENTION

For over a decade, the military has been devoting a large amount of research and development funding to research projects directed to reducing the impact and shock sensitivity of the main explosive charge in munitions. A main challenge is to reduce sensitivity of the main explosive charge without decreasing performance while also not significantly increasing cost. One of the main charge explosives in munitions formulations is a four member strained ring compound. The chemical name of the compound is 1,3 , 3—trinitroazetidine, hereinafter referred to as TNAZ.

The explosive TNAZ was developed by a team led by Dr. Tom Archibald and produced by a modified Fluorochem process developed by Dr. Archibald. The current primary producer is Dr. Archibald at Gencorp, Aerojet Propulsion Division, P.O. Box 13222, Sacramento, California, 95813. TNAZ is a four member strained ring having the structure

TNAZ has a melting point of 101°C and it decomposes at 249°C.

The only known practical way to reduce the sensitivity of these formulations is to increase the amount of inerts and less sensitive components therein and thus decrease the sensitivity of the formulation but this also reduces the performance of the formulation. Further, extensive discussion of this problem is set forth in U. S. Patent No. 4,842,659. In this patent it is stated that insensitive munitions must be developed to improve the combat εurvivability of an armament vehicle. It has been found that munitions utilized in some weapon systems are vulnerable to sympathetic detonation. For instance, the cannon caliber ammunition stored aboard these vehicles is vulnerable to initiation via shape charge jet and then propagation of the reaction due to sympathetic detonation.

This sympathetic detonation and propagation scenario can be summarized as follows: If a round is hit by a shape charge jet, it is initiated. As a result, the fragments that are generated by the blast then strike the other rounds that are adjacent to it. The latter rounds then initiate, contributing to the overall reaction and damage sustained by the vehicle, crew, and other munitions. The mechanisms of reaction for the initiation of the surrounding rounds are due to the blast and fragments impinging on the aforesaid adjacent round. The probability of sympathetic detonation can be reduced in several ways. This can be done by reconfiguring the ammunition compartments within the vehicle. It can also be accomplished by packaging the ammunition with anti—fratricide materials. However, each of the aforesaid solutions will reduce the amount of space available for the storage of ammunition. The most acceptable solution to the problem is to reduce the sensitivity of the energetic material to sympathetic detonation. Incorporating less sensitive energetic material will reduce the vulnerability of initiation from the cited threats without reducing the number of rounds stored in the vehicle. It has been found that by reducing the vulnerability to sympathetic detonation of the energetic materials used in these munitions, the probability of catastrophic reaction can be minimized.

The mechanism generally accepted within the explosives community for detonating or deflagrating explosives is the creation of very localized regions of high temperature, i.e., hot spots. The application of impact or shock on the explosive can generate hot spots in the following ways: (1) by adiabaticly compressing air (or explosive vapor) bubbles trapped in or purposely introduced into the explosive, (2) by intercrystalline friction, (3) by friction of the impacting surfaces, (4) by plastic deformation of a sharply—pointed impacting surface, and (5) by viscous heating of the impacted material as it flows past the periphery of the impacting surfaces.

In the compression and movement of explosive crystals due to impact or shock, explosives like TNAZ rapidly evolve into simpler products as well as free radicals and unstable intermediates. This mixture of products is believed to be unstable and subject to detonation when exposed to a low intensity shock induced spark of static electricity. The creation and build—up of static electricity may be an additional source of energy which contributes to the detonation of the explosive and its decomposition products.

BRIEF SUMMARY AND OBJECTS OF INVENTION

The present invention is directed to TNAZ formula— tions in which the TNAZ is coated with shock sensitivity reducing agents to reduce the shock sensitivity of TNAZ. Agents which were found to be useful in this invention were from four primary classes of compounds. The classes are: 1) Quaternary Ammonium Salts; 2) Anionic Aliphatic and Aromatic Compounds; 3) Fatty Acid Esters; and 4) Amine Derivatives;

"Quaternary ammonium salts" are cationic nitrogen containing compounds with four various aliphatic or aromatic groups as discussed above for the amine derivatives. The selected anion is generally a halogen, acetate, phosphate, nitrate, or methosulfate radical. Inclusive in this category are quaternary imidazolinium salts where two of the aliphatic group bonds are contained within the imidazole ring. "Anionic aliphatic and aromatic compounds" are compounds normally containing a water insoluble aliphatic group with an attached hydrophilic group. They are often used as surfactants. The hydrophilic portion of these anionic compounds is a phosphate, sulfate, sulfonate, or carboxylate; sulfates and sulfonates predominate.

"Fatty acid esters" is a term used broadly that covers a wide variety of nonionic materials including fatty esters, fatty alcohols and their derivatives. Although once limited to compounds obtained from natural fats and oils, the term "fatty" has come to mean those compounds which correspond to materials obtainable from fats and oils, even if obtained by synthetic processes. They can generally be εubclassified as: (1) fatty esters (e.g., sorbitan esters (e.g., mono— and di— glycerides) ) , (2) fatty alcohols, and (3) polyhydric ester—alcohols. The exact classification of these compounds can become quite confused due to the presence of multiple functional groups. For example, ethers containing at least one free —OH group fall within the definition of alcohols, (e.g., glycerol—1, 3—distearyl ether) . Synthetic compounds such as polyethylene glycol esters can also be included in this category.

"Amine derivatives" describes a wide variety of aliphatic nitrogen bases and their salts. Amines and their derivatives may be considered as derivatives of ammonia in which one or more of the hydrogens have been replaced by aliphatic groups. Preferred amine salts are formed by reaction with a carboxylic acid to form the corresponding salt. The amine and the carboxylic aliphatic groups can be unsubstituted alkyl, alkenyl, aryl, alkaryl, and aralkyl or substituted alkyl, alkenyl, aryl, alkaryl and aralkyl where the substituents are groups consisting of halogen, carboxyl, or hydroxyl.

Agents evaluated are presented in Table 1 of the example. The focus in obtaining these materials was availability and toxicity. Secondarily, water insolubility was highly desired due to ease of incorporation into existing explosives manufacturing processes.

The agents listed in Table 1 were classified in accordance with the four primary classifications listed above. Classification of some of the agents were assumed based upon MSDS information since the exact chemical structure was proprietary. Agents were obtained representing all four categories. Compounds from all three εubclassification referenced above for the fatty acid esters are also represented. The list of possible compounds that can be employed within these categories is almost infinite due to the aliphatic group size, structure (branched or straight) , additional functional groups, quantity, combination, and arrangement. Since the evaluation could become endless, agents were chosen to represent the widest variety practical within each chosen category.

It is an object of this invention to reduce the impact and shock sensitivity of TNAZ formulations without significantly reducing the performance of the main charge explosive. It is another object of this invention to reduce the sensitivity of TNAZ formulations without significantly increasing the cost of manufacturing the TNAZ formulations.

Other objects and variations of this invention will become obvious to the skilled artisan from a reading of the following detailed specification.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a pictorial view of the HDC Impact Machine.

DETAILED DESCRIPTION OF THE INVENTION

The invention is a high energy explosive formulation characterized by reduced susceptibility to impact and sympathetic detonation due to shock forces, the formulation comprising TNAZ and a shock sensitivity reducing agent, the shock sensitivity reducing agent being present in an amount effective to impart an increase in HDC Impact Value to the formulation which is statistically significant. A HDC Impact Value of 46.45 centimeters has been found to be statistically significant for TNAZ. The shock sensitivity reducing agent may be a quaternary ammonium compound; an anionic aliphatic or aromatic compound; a fatty acid ester; or a long chain amine.

Preferred quaternary ammonium compounds have the formula

wherein R is hydrogen, alkyl having 8-22 carbon atoms, aryl having 6—30 carbon atoms, alkaryl having 7—30 carbon atoms, aralkyl having 7—30 carbon atoms, or H(OCH₂CH₂)_n wherein n is 1 to 50,

_n

wherein n is 1 to 50, alkaryl having 8—20 carbon atoms, or hydroxyethyl . R₂ is the same as R_χ, R₃ is hydrogen, alkyl having 1—22 carbon atoms, aryl having 6—30 carbon atoms, H(OCH₂CH₂)_n — wherein n is 1 to 150, or hydroxyethyl, R₄ is hydrogen or alkyl having 1—4 carbon atoms, and X^~ is halogen, carboxylate having 2—22 carbon atoms, nitrate, sulfate, methosulfate or phosphate.

Other preferred quaternary ammonium chloride formulations are bis (hydrogenated tallow alkyl) dimethyl quaternary ammonium chloride; trimethyl tallow alkyl quaternary ammonium chloride; (CH₃)₃N⁺R Cl^~, wherein R is a mixture of long chain aliphatic and unsaturated aliphatic alkyl groups containing 14 to 18 carbon atoms; hydrogenated tallow alkyl (2—ethylhexyl) dimethyl quaternary ammonium methosulfate, N,N,N—tris (2—hydroxy— ethyl) tallow alkyl ammonium acetate;

(HOCH₂CH₂ ) ₃N⁺R OCCfζ ,

wherei.n R i.s a mi.xture of ali.phati.c and unsaturated aliphatic alkyl groups containing 14 to 18 carbon atoms;

dimethyl di(cocoalkyl) quaternary ammonium chloride; R₂N⁺(CH₃)₂ Cl^~, wherein R is C₆ - C₁₈ alkyl and unsaturated alkyl groups; methyl bis (2—hydroxyethyl) cocoalkyl quaternary ammonium chloride; trialkyl polyalkoxyalkylene quaternary ammonium chloride; and R₃N⁺CH₂CH₂(OCH₂CH₂)_nOH Cl^~, wherein R is methyl and n is 1-250. A preferred anionic aliphatic shock sensitivity reducing compound is sodium alkane sulfonate where the alkane group has 6—18 carbon atoms.

A preferred anionic compound is a soap or detergent based on the lithium, potassium or sodium salts of carboxylic acids containing about 8—26 carbon atoms or similar salts based on alkylbenzene sulfonates. Also the salt may be a triethanolamine salt of a carboxylic acid having about 8 to about 26 carbon atoms or triethanolamine salts based on alkylbenzene sulfonates wherein the alkyl groups contains 8—18 carbon atoms.

Preferred long chain amines are bis(2-hydroxyethyl) tallow alkyl amine, (HOCH₂CH₂)₂NR wherein R is C₁₂—C₁₈.

wherein R¹ is C₁₂—C₁₈;

[H(OCH₂CH₂)_nOCH₂CH₂]₂NR

wherein R is C₁₂ to C₁₈ and n is 1—150, and

[H(0CH2CH2.) n0CH2_CH2

<: wherein R¹ is C₁₂ to C₁₈ and n is 1 to about 150. The long chain amine may be ethoxylated cocoalkyl amine where cocoalkyl is C₈—C₁₈ saturated or unsaturated group.

Preferred fatty acid esters are glycerol esters having the formula

wherein R is about C₈ to C₁₈,

Other shock sensitivity reducing compounds useful in this invention are water soluble or water dispersible quaternary ammonium salts which include: Arquad 2HT—75 from Akzo Chemicals Inc. (bis (hydrogenated tallow alkyl) dimethyl quaternary ammonium chloride) ;

Arquad T50 from Akzo Chemical Inc. (trimethyl tallow alkyl quaternary ammonium chloride) (CH₃)₃ N⁺R Cl- where R is a mixture of long chain aliphatic and unsaturated aliphatic groups containing 14 to 18 carbon atoms;

Arquad HTL8—MS from Akzo Chemicals Inc. (hydrogenated tallow alkyl (2—ethylhexyl) dimethyl quaternary ammonium methosulfate) ;

Ethoquad T/13-50 from Akzo Chemicals Inc. (N-N-N- tris (2—hydroxyethyl) tallow alkyl ammonium acetate) ,

wherein R is a mixture of aliphatic and unsaturated aliphatic alkyl groups containing 14 to 18 carbon atoms; Arquad 2C—75 from Akzo Chemicals Inc. , Dimethyl di (cocoalkyl) quaternary ammonium chloride

R₂N⁺(CH₃)₂ Cl^~ wherein R = C₆-C₁₈ alkyl and unsaturated alkyl groups; Ethoquad C/12-75 from Akzo Chemicals Inc. (methyl bis (2—hydroxyethyl) cocoalkyl quaternary ammonium chloride) ;

Markstat AL-12 from Witco Chemical Corp. (trialkyl polyalkoxyalkylene quaternary ammonium chloride) ; and Staticide 30006 from ACL Inc. (a quaternary ammonium compound) (Structure proprietary.)

Other useful quaternary ammonium salts are derived from diamines, triamines or polyamines.

For example quaternary ammonium salts derived from ethylenediamine; diethylenetriamine; hexamethylene— diamine; 1—4 cyclohexane—bis—methylamine (can use cis, trans or ciε/trans mixture) ; phenylenediamine. Typical salts would be hexamethyl ethylene diammonium chloride; hexamethylene phenylene diammonium sulfate; and dimethyl tetrahydroxyethyl 1—4 cyclohexylenedimethylene diammonium chloride.

Water soluble anionic aliphatic compounds and aromatic compounds which are useful include: Dehydat

93P from Henkel Corp. which is a sodium alkane sulfonate (alkane not specified but probably C₈—C₁₈) .

Soaps or detergents based on the lithium, potassium, sodium on triethanolamine salts of carboxylic acids containing 8 to 26 carbon atoms or similar salts based on alkylbenzene sulfonates. Other useful salts include: sodium octanoate, sodium decanoate, sodium laurate, sodium myriεtate, sodium palmitate, sodium stearate, sodium oleate, sodium linoleate.

Also useful are sodium, lithium or potassium salts of mixed acids such as those obtained from tallow and coconut oil. A typical one would be a sodium salt of mixed acids containing 12, 14, 16 and 18 carbon atoms.

Some typical useful alkylbenzene εulfonates include: dodecylbenzenesulfonic acid, dodecylbenzene— sulfonic acid sodium salt, dodecylbenzenesulfonic acid triethylamine salt, nonylbenzenesulfonic acid, nonyl— benzenesulfonic acid sodium salt, and mixed C₁₀ to C₁₃ alkylbenzenesulfonic acid salts. Useful sodium alkane— εulfonates include sodium dodecanesulfonate, εodium stearylsulfonate, and εodium myristylsulfonate. Useful alkylnaphthalenesulfonate salts include sodium isopropylnaphthalenesulfonate, sodium nonylnaphthalene— sulfonate. A useful a—olefin sulfonate is mixed 1—octene, 1—decenesulfonic acid sodium salt. A useful dialkyl sulfosuccinate iε di 2—ethylhexyl εulfosuccinic acid sodium salt. A useful amidosulfonate iε εodium N— oleoyl—N—methyl taurate. A uεeful εulfoethyl ester of fatty acid is sodium sulfoethyl oleate.

A useful alcohol sulfate is sodium lauryl sulfate. Ethoxylated alcohol εulfates such as sodium poly— ethoxyethylene sulfate; ethoxylated alkyl phenol εulfateε; phoεphate esters — usually used as a mixture of mono, di, and trieεter are uεeful in thiε invention. Uεeful fatty acid eεterε are glycerol esters such aε glycerol onoεtearate, glycerol distearate, and glycerol dilaurate which are usually a mixture of mono and diesterε. Many productε are derived from naturally occurring fatε such as tallow, lard, cottonseed, safflower oil and the like and will be mixtures of fatty acids containing about 12 to about 18 carbon atoms. Also useful are polyoxyethylene esterε; amine derivativeε, and bis (2—hydroxyethyl) tallow alkyl amine. Other operable amines include dialkylethanolamines in which the alkyl groups contain 12 to 18 carbon atoms; ethoxylated amines such as alkyl polyethoxyethyla ines in which the alkyl group is about 12 to 18 carbon atoms, and ethoxylated cocoamine.

Shock sensitivity reducing agents useful in this invention exhibit anti—static properties.

DESCRIPTION OF HDC IMPACT MACHINE

The impact sensitivity of TNAZ explosives iε determined on a drop weight test machine comprising a mechanism for dropping a 5 kilogram weight from a chosen height on a selected sample of explosive. The sample weight is normally 0.025 or .035 grams. The sensitivity value is expresεed as the height in cm from which the weight is dropped for the probability of an explosion to be 50 percent.

The HDC impact machine is shown in Figure 1. The machine comprises metal base plate 1 which is generally square, about 16 inches per side, and is about one and one—half inches thick. On the base plate there are located three tapped holes to receive guide rods 7, 9 & 11. Two of the holes are located about four (4) inches from the front edge 3 of the base plate and three (3) inches on either side of a center line extending from the front edge 3 to the back on opposite edge 5 of the generally square base plate. The third hole is located on said center line about ten and one— alf inches from the front edge 3. In the three holes are mounted two guide rods 7 and 9 and a graduated guide rod 11. The graduated guide rod 11 has centimeter graduationε formed thereon and are used to indicate the height of a five kilogram weight used with the apparatus (discussed later herein) . A guide rod 7 is mounted in a hole spaced about 4 inches from the front edge 3 of the mounting block 1. A guide rod 9 is mounted in the third hole formed in the base plate as described above. A fourth hole is formed in the base plate 1 to receive a lift rod 13. The hole is located eight and one—half inches from the front edge of said base plate. The lift rod 13 iε threaded itε full length and is mounted for rotation in a bearing (not shown) located in said fourth hole. A fifth hole is formed in the base plate centered and is three inches from the back edge of the base plate 1. In this hole iε mounted a support rod 15. A top plate 17 having the dimension of ten by thirteen inches is provided with holes positioned in the same configuration as the holes in the base plate for receiving the upper ends of the guide rods 7, 9 and 11, the lift rod 13 and the support rod 15 to space and hold all five rods parallel to each other. A magnet retainer plate 19 is provided and has holes matching the pattern of those in the top plate 17 and the base plate 1, with the exception of the support rod receiving hole. The magnet retainer plate 19 is positioned between the base plate 1 and the top plate 17. Guide rod 7 and graduated guide rod 11 pasε through the holeε located on the front portion of the magnet retainer plate 19 and guide rod 9 paεses through the hole located at the back of the magnet retainer plate. The lift rod 13 is threaded through a lift rod nut 21 which iε attached to the magnet retainer plate over the corresponding hole in the plate. The lift rod is mounted in bushings for rotational movement to move the magnet retainer plate up and down between the base plate l and the top plate 17. The lift rod has a 45° miter gear 23 attached to its lower end adjacent the base plate 1 to cooperate with a second miter gear mounted on a ball crank shaft and handle 27 which will, when turned, rotate the lift rod 13 for moving the magnet retainer plate up and down as required. Mounted on the magnet retainer plate 19 iε an electromagnet 29 whereby the height of the magnet may be adjusted by the operator by turning the ball crank handle to move the magnet retainer plate 19 up or down as necessary. A five kilogram weight 31 is provided and is adapted to be held by the electromagnet. The weight is provided with opposed flanges 37 which cooperate with guide rod 7 and graduated guide rod 11 whereby when the weight 31 is released from the electromagnet 29 the weight will freely fall to contact a plunger assembly 33 which strikes an anvil 34. Mounted on the base plate 1 is an anvil and plunger holder 35. The holder is attached to the base plate in a position to hold the anvil and plunger directly below the five kilogram weight so that the falling weight will strike the plunger which in turn will strike a sample located on the anvil. Also, a εecond anvil εurface (not εhown) iε mounted in the bottom center of the five kilogram weight. The anvilε are made from tool εteel heat treated to 56 to 60 pointε Rockwell Hardneεε. The plunger 33 iε made from tool steel heat treated to 56 to 60 points Rockwell Hardness. The plunger may be two inches in length overall, 0.50 inches in diameter and is tapered at near one end from 0.50 to 0.303 inches which extends for about 3/16 of an inch to form the striker portion of the plunger. Both ends of the plunger are ground to be perpendicular to the center line of the plunger. The anvilε are cylinders which are one and one half inches tall and one and one quarter inches in diameter. The plunger is slidingly mounted in a bushing mounted in the plunger holder 35 which iε centered directly over the second or bottom anvil 34.

In use the lift rod 13 is rotated to raise the electro magnet to preselected heights. The five kilogram weight will freely fall the preselected distance to strike the upper end of the plunger which in turn will strike a εample placed in a sample cup which is located directly below the small end of the plunger. The sample cup iε made from braεs and iε 0.008 inches thick, 0.303 incheε in diameter and 0.20 incheε in height.

A detailed procedure for using the HDC Impact machine follows:

Interferences in the test may be: 1) a machine loosely asεembled or not in proper alignment may produce incorrect values; 2) a rough surface or cracks on the anvil or plunger may produce low sensitivity values; 3) insufficient or unevenly distributed sample may produce incorrect values; 4) a sample containing glasε, metal, or other gritty matter foreign to the product may produce low εenεitivity valueε; and 5) wet εamples or sampleε containing oil, greaεe, and or soft plasticε may produce high εensitivity values.

Equipment needed iε: 1) a εample splitter or glazed paper; 2) caps, percuεεion, 0.303 in diameter, 0.200 in height, and 0.008 inches thick; 3) spoon, loading, 0.025 and 0.035 gm; 4) spatula, wood; 5) tong, laboratory; 6) bruεh, approximately 2 incheε wide; 7) oven, εteam heated; and 8) a HDC Impact machine. The machine shall be tested with a sample having a known sensitivity range. The results are plotted on a control chart and corrections taken if the first point fails to plot within control limits or if 5 successive points all plot on one side of the center line. Position 25 brasε percussion caps, with open end up, on a flat surface. Fill the 0.025 gram loading spoon with the dry explosive and smooth off the excess by drawing a wooden spatula over the flat surface of the spoon. Dump the remaining portion into one of the prepared caps. Repeat Step 2 until each percussion cap is loaded. Ascertain explosiveε to be evenly diεtributed in each cap. Remove fumes and dust from the area of the impact machine. Uεing the laboratory tongs, place a loaded percussion cap on the anvil of the impact machine. While holding the cap with the tong, insert the plunger through the guide hole above the anvil and into the percusεion cap. Turn the electromagnet switch to the "ON" position. Adjust the height of the electromagnet by turning the ball crank handle until the base of the lower magnet arm coincides with the 35 cm mark on the guide rod 11. Lower the safety shield (not shown in drawing) and lift the weight vertically until it is held in place by the electromagnet. (The weight normally rests upon a safety εhield while the machine is being charged) . Face the oppoεite direction from the impact machine, turn the electromagnet switch to the "OFF" position, allowing the weight to fall and strike the top of the plunger. Lift the weight. Examine the percusεion cap to determine if an explosion has occurred. An exploded cap is usually disintegrated; however, partial exploεionε may be determined by inεpecting the cap for partε of the rim blown away. An exploεion may also be recognized by a sharp report or by smoke in the area of the plunger. Clean all unexploded material and partε of the percussion cap from the anvil, plunger, and base plate with a brush or cloth. Repeat Steps 5 thru 12 raising the electromagnet 5 cm after each non—explosion and lowering the electromagnet 5 cm after each explosion. The first non—explosion after an explosion is considered as the starting point of the 20 tests. Record this height in cm. Raise the electromagnet 5 cm and repeat Steps 5 thru 12. Raiεe or lower the electromagnet as required and repeat the steps until 20 tests have been completed. Record each test result. Assume each test exploding at a recorded height would have exploded at greater heights. Assume each non—explosion at a recorded height would fail to explode at heights less than the recorded height. Perform calculations for impact value.

CALCULATION FOR IMPACT

1. Calculate the percentage explosions at a given height.

Explosions, % = A x 100

B

Where A = Number of explosions at a given height B = Total number of explosions and non- explosions at a given height

Record the percentage explosions.

Calculate the impact sensitivity as follows:

Impact sensitivity, cm = C — 5 (D—50)

D-E

Where C = The lowest height in cm at which more than 50% explosions occurred. D = Percentage explosionε greater than

50%.

E = Percentage explosions lesε than 50%. 5 = Difference in height in cm of each teεt.

The invention will be further illuεtrated by conεideration of the following examples, which are intended to be exemplary of the invention. EXAMPLE

Compositions comprising TNAZ and a series of shock sensitivity reducing agents were prepared according to the procedure set forth. The concentrationε, the εhock sensitivity reducing agents and the HDC Impact Value required for detonation at different concentrations of the agents in the TNAZ are shown in Table 1. Also there is indicated in the Table the calculated concentration required for the formulation to reach the statistically significant increase in the HDC Impact Value.

DSC scans were run on TNAZ and each agent. Sample size for the analyεis was 4.5 to 5.5 g. The analysis was performed on a DSC (Differential Scanning Calorimeter) . Samples of TNAZ that were prepared for impact teεting with a 3% addition of an agent were alεo analyzed by DSC to determine compatibility. None of the mixtures showed abnormal exothermε.

The TNAZ waε coated with the water εoluble agentε by weighing 23.75 + 1.25 gms of the dry explosive with varying amounts of the agents to produce an end compoεition ranging from 0.10% to 6.00%. For the external coating, 5 ml of H₂0 waε added to the weighed agent. The agent waε added to the dry TNAZ and mixed in a 100 ml beaker for 5 minuteε. The beaker and contentε were placed in a steam heated oven (200°F) for 15 minutes. The heating and stirring procedure was repeated until the exploεive was dry. The standard HDC impact test was run on each prepared sample. The lab procedure iε described herein.

A coating procedure was developed which took advantage of the low melting point (50-80°C) of the water insoluble agents. The procedure consiεtε of weighing 23.75 + 1.25 gms of the dried explosive into a 100 ml beaker. The agent was added to the beaker along with 5 ml of water. The mixture was placed in a steam heated oven at 200°F for about 15 minutes which was enough time to melt the agent. The contents of the beaker were stirred for 5 minuteε. The beaker waε placed in the oven again. The heating and εtirring procedure waε continued until all the water had evaporated. Impact reεultε indicate that thiε procedure produced homogenous εampleε.

The εoluble agent chosen for the evaluation with TNAZ was bis (hydrogenated tallow alkyl) dimethyl quaternary ammonium chloride (2HT—75 — Akzo Chemicals) . TNAZ coated with this agent (2% of the product) had an impact of 20.0 cm.

The insoluble agent choεen for evaluation waε diεtilled monoglyceride (PA 208 — Eaεtman Chemical Company) . The TNAZ containing 2% agent (2% of the product) had an HDC Impact Value of 18.7 cm as compared to 11.46 cm with no coating.

The statiεtically significant impact values set forth in the Table were determined aε εet forth.

A normal untreated TNAZ product haε known average and εtandard deviation values when tested on a standard Holεton Impact Machine. The impact value of a given εample would not be expected to be more than 3 standard deviation units larger than the average (the probability of being less than 3 units above average from normal distribution tables iε 0.9987). Thus, if an agent is added to a εample and the impact value of thiε εample iε more than 3 standard deviation units above the average, it can be asεumed that the additive haε caused this result and the result iε said to be statistically significant.

For the experiments, samples of a fixed product with varying amounts of agent were prepared and the impact value of each sample was determined. The impact resultε were plotted againεt the %—additive in each εample. From this graph, a %—additive above which the impact value becomes more than 3 standard deviation units greater than the average can be determined. Observation of these graphs (covering a wide range of products and %—additives) εhow that the curves, in the region where the 3 standard deviation value (critical value) iε exceeded, are eεsentially linear with some random variation. Based upon this, a linear curve of the form

Y = X + b

where Y = impact value and x = %—additive

was fitted to the data by the method of least squareε. Thiε formula waε then used to calculate the %—additive at which the impact value becomes greater than the critical value.

Thiε illustrative procedure describeε uεing TNAZ aε the explosive component and bis (hydrogenated tallow alkyl) dimethyl quaternary ammonium chloride (Arquad 2HT—75 from AKZO Chemical) aε the εhock sensitivity reducing agent. Thiε procedure illuεtrateε the preparation of a final mixture containing 99% TNAZ and 1% Arquad 2HT—75. Other concentrationε are prepared by varying the proportionε of the ingredientε in the mixture. Compoεitionε compriεing TNAZ and a εhock εensitivity reducing agent (Arquad 2HT-75) are prepared following the procedure set forth below:

A. Weigh 0.3333 grams of the Arquad 2HT-75 into a 100 ml beaker. B. Add 5 ml H₂0 to provide a mixing media for coating the TNAZ crystalε with the Arquad 2HT—75. Other liquids such aε iεopropanol will also work.

C. Stir the mixture of Arquad 2HT-75 and liquid with a rubber tipped glass tipping rod until the 2HT—75 iε well dispersed.

D. Weigh 24.7500 gms of TNAZ and pour into a beaker containing the Arquad 2HT—75.

E. Stir the mixture with a rubber tipped stirring rod for about 5 minutes .

F. Place the beaker in a steam heated oven at about 200°F for 15 minutes.

G. Remove the sample from the oven.

H. Stir the mixture with the rubber tipped glass stirring rod for 5 minutes.

I . Place the beaker in the steam heated oven (200°F) for another 15 minuteε.

J. Remove the εample from the oven and εtir for 5 minutes.

K. Weigh and record the weight of the beaker.

L. Return the beaker to the oven for 15 minutes.

M. Stir for 5 minutes and weigh the beaker. N. Continue the heating and stirring procedure until there is no weight loss after heating.

Table 1 alεo εhows the test results uεing other shock senεitivity reducing compoundε, identified in the Table, mixed with TNAZ in various concentrations. The agents tested are representive of the large number of compounds which are useful in this invention.

Table 1

Calculated Concentration

Required to Reach the

Concentration % Statistically Significant

Shock Sensitivity in CL-20 HDC Impact HDC Impact Value Reducing Compound Formulation Value (cm) of 46.45 cm

Bis (hydrogenated tallow 0.00 36.11 1.589% alkyl) dimethyl quaternary 1.00 45.30 ammonium chloride — 2.00 52.70 (Arquad 2HT-75) from 4.00 90.80 AKZO Chemicals Inc. 6.00 91.10

Distilled monoglycerides 0.00 36.11 1.0404% PA—280 from Eastman 1.00 45.80 Chemical Company 2.00 61.90

4.00 79.20

6.00 95.00

Sodium alkane sulfonate 0.00 36.11 1.45% Dehydat 93 P from 1.00 44.20 Henkel Corporation 2.00 49.20

4.00 61.40

6.00 95.00

Ethoxylated cocoalkyl 0.00 36.11 0.9583% amine 1.00 46.90

Kemamine AS—650 2.00 51.40

4.00 59.20

6.00 89.20

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications will be effected within the spirit and scope of the invention.

Claims

1. High energy explosive formulation characterized by reduced suεceptibility to impact and εympathetic detonation due to εhock forces, said composition comprising TNAZ, and a shock sensitivity reducing agent, said shock senεitivity reducing agent being preεent in an amount effective to impart an increase in HDC Impact Value to the formulation which is statiεtically significant.

2. Formulation of claim 1 wherein the HDC Impact Value is at least 46.45 centimeterε.

3. Formulation of claim 1 wherein εaid εhock εensitivity reducing agent is εelected from quaternary ammonium compoundε, anionic aliphatic compoundε and anionic aromatic compoundε, fatty acid eεters, and amine derivatives.

4. Formulation of claim 3 wherein said εhock εenεitivity reducing agent is a quaternary ammonium compound.

5. Formulation of claim 3 wherein said shock εensitivity reducing agent is an anionic aliphatic or aromatic compound.

6. Formulation of claim 3 wherein said shock senεitivity reducing agent iε a fatty acid eεter.

7. Formulation of claim 3 wherein said shock senεitivity reducing agent iε an amine derivative. Formulation of claim 4 wherein said quaternary ammonium agent has the formula

wherein ^_^ iε hydrogen, alkyl having 8—22 carbon atoms, aryl having 6—30 carbon atoms, alkaryl having 7—3 carbon atoms, aralkyl having 7—30 carbon atoms, or H(OCH₂CH₂)_n wherein n is 1 to 50, wherein n is 1 to 50, alkaryl having

8—20 carbon atoms, or hydroxyethyl,

R₂ is the same as R_lf R₃ is hydrogen, alkyl having 1—22 carbon atoms, aryl having 6—30 carbon atoms, H(OCH₂CH₂)_n - wherein n is l to 150, and hydroxyethyl, R₄ iε hydrogen or alkyl having 1—4 carbon atoms, and X- iε halogen, carboxylate having 2—22 carbon atomε, nitrate, εulfate, methoεulfate or phosphate.

Formulation of claim 4 wherein εaid ammonium compound is dimethyl ditallow alkyl quaternary ammonium chloride.

10. Formulation of claim 4 wherein said ammonium compound iε tri ethyl tallow alkyl quaternary ammonium chloride.

11. Formulation of claim 4 wherein εaid ammonium compound iε (CH₃)₃ N⁺RC1^~, where R is a mixture of long chain aliphatic and unsaturated aliphatic alkyl groups containing 14 to 16 carbon atoms.

12. Formulation of claim 4 wherein εaid ammonium compound iε hydrogenated tallow alkyl

(2—ethylhexyl) dimethyl quaternary ammonium methoεulfate.

13. Formulation of claim 4 wherein said ammonium compound is dimethyl 2—ethylhexyl tallow alkyl ammonium methosulfate.

14. Formulation of claim 3 wherein the ammonium compound iε N,N,N—tris (2—hydroxyethyl) tallow alkyl ammonium acetate.

15. Formulation of claim 4 wherein the ammonium compound is

+ / (HOCH₂CH₂)₃N R OCCH.

where R iε a mixture of aliphatic and unεaturated aliphatic alkyl groups containing 14 to 18 carbon atoms.

16. Formulation of claim 4 wherein εaid ammonium compound iε dimethyl di (cocoalkyl) quaternary ammonium chloride.

17. Formulation of claim 4 wherein εaid ammonium compound iε R₂N⁺(CH₃) ₂C1^~, where R iε C₈ to C₁₈ alkyl and unεaturated alkyl groups.

18. Formulation of claim 4 wherein εaid ammonium compound is methyl bis(2—hydroxyethyl) cocoalkyl quaternary ammonium chloride.

19. Formulation of claim 3 wherein εaid ammonium compound iε

where R iε C₈ to C₁₈ alkyl and unεaturated alkyl groupε .

20. Formulation of claim 4 wherein εaid ammonium compound iε trialkyl polyalkoxyalkylene quaternary ammonium chloride.

21. Formulation of claim 3 wherein εaid ammonium compound iε R₃N⁺CH₂CH₂ (OCH₂CH₂)_nOH where R is methyl and n iε 1 to 150.

22. Formulation of claim 3 wherein εaid εhock εensitivity reducing compounds are selected from anionic aliphatic compounds and anionic aromatic compounds .

23. Formulation of claim 22 wherein εaid εhock εensitivity reducing agent is εodium alkane sulfonate where the alkane group has 6—18 carbon atomε .

24. Formulation of claim 22 wherein εaid εhock εenεitivity reducing compound iε a εoap or detergent baεed on the lithium, potaεεium or εodium salts of carboxylic acids containing 8 to 26 carbon atoms and like salts based on alkylbenzene sulfonateε.

25. Formulation of claim 22 wherein the εhock εenεitivity reducing agent iε a triethanolamine salt of carboxylic acids having 8 to 26 carbon atoms .

26. Formulation of claim 3 wherein said shock sensitivity reducing agent is a long chain amine.

27. Formulation of claim 26 wherein said shock εensitivity reducing agent iε biε (2—hydroxyethyl) tallow alkyl amine.

28. Formulation of claim 26 wherein εaid εhock εenεitivity reducing agent iε (HOCH₂CH₂) ₂NR where R is C₁₂—C₁₈.

29. Formulation of claim 3 wherein εaid εhock εenεitivity reducing agent iε εelected from

where R¹ is C₁₂-C₁₈

[H(0CH₂CH₂)_n0CH₂CH₂]₂NR where R is C₁₂-C_lg and n is 1—150 and _lg

30. Formulation of claim 29 wherein the shock senεitivity reducing agent iε ethoxylated cocoalkyl amine where cocoalkyl iε C₈—C₁₈ εaturated or unεaturated.

31. Formulation of claim 3 wherein the shock sensitivity reducing agent is a fatty acid ester.

32. Formulation of claim 3 wherein εaid εhock εenεitivity reducing agent iε a glycerol eεter εelected from

where R iε C₈ to C₁₈,

and glycerol monoεtearate, glycerol monolaurate, glycerol dilaurate and glycerol diεtearate.