Патент USA US2407597код для вставки
Patented Sept. 10, 1946 2,407,597 UNITED STATES PATENT OFFICE 2,407,597 EXPLO SIVE COMPOSITIONS COMPRISING LOW FREEZING LIQUID MIXTURES OF AROMATIC NITRO-COMIPOUNDS Harold B. Wright, West Kilbride, and James Tay lor, Saltcoats, Scotland, assignors to Imperial Chemical Industries Limited, a corporation of Great Britain ' No Drawing. Application March 2, 1944, Serial No. 524,792. In Great Britain December 12, 1942 5 Claims. (CI. 52-13) 1 2 The present invention relates to new or im dissolved or partly dissolved in a liquid having a solvent action upon it. In practice explosive compositions are often exposed to temperatures somewhat below the temperature of melting ice, and the provision of explosive aromatic nitro-com pounds, whether single or mixed, that are'capable of withstanding su-ch temperatures Without crys tallisation of solid, has hitherto been a matter of much di?iculty. The lack of a suitable ex-' proved low freezing explosive compositions, and in particular to the provision of improved explo sive compositions comprising new liquid explosive mixtures of aromatic polynitro-coinpounds that are characterised by unusually low freezing points. The invention relates more especially, but not exclusively, to the provision of new or improved low freezing explosives of plastic, gelatinous, or semi-gelatinous consistency in which nitrocel plosive nitro-cellulose-m'tro-aromatic body jelly that will not become rigid at temperatures some lulose is gelatinised by the aforesaid new liquid what below that of melting ice has hitherto mili explosive mixtures of aromatic polynitro-com tated against the development of gelatine explo pounds. The new liquid explosive mixtures of sives in which nitro-aromatic compounds are used aromatic polynitro-compounds may also be em 15 in place of nitro-glycerine, although from certain ployed in admixture with other commonly used points of view it might be advantageous to produce ingredients of explosive compositions, and are such explosives. The handling of nitroglyce-rine,v especially suitable for the production of low freez for instance, frequently induces headaches in ing explosives of relatively high power and low those engaged in the manufacture of the explo sensitiveness to friction and shock. The result 20 sives. ' ing low freezing composite explosive compositions It is an object of the present invention to pro-1 may be used for blasting, military demolition, pro vide an explosive composition comprising a low; pulsive or other purposes depending on the com freezing liquid mixture of aromatic nitro-coma position of their ingredients. pounds that contains a larger nitro-group content In the manufacture of explosives of the kind 25 and hence is of higher calori?c value, or that in which there is employed, instead of a liquid commences to crystallise at a lower temperature, nitric ester or mixture of liquid nitric esters, a than the hitherto used liquid aromatic nitro-com liquid aromatic nitro-compound or liquid mixture pound mixtures. It is also an object of the in of aromatic nitro-compounds, the di?iculty arises vention to prepare new and useful composite ex that in general the freezing points of the individ 30 plosive compositions in the preparation whereof ual nitro derivatives of an aromatic compound the aforesaid new low freezing liquid aromatic are the higher the greater the number of nitro nitro-compounds are used as a constituent. It is groups that have been introduced into its mole in particular an object of the invention to pro cule; and in order to obtain compositions that are vide low-freezing nitro-aromatic gelatine explo liquid at a temperature about that of melting ice 35 sives. it has hitherto been necessary to employ individ According to the invention, the low freezing ual nitro-aromatic compounds or mixtures of aromatic nitro-compound mixture consists to the nitro-aromatic compounds having an undesir extent of about 70 to 85 per cent. of a mixture of ably low nitro-group content, so that the result isomeric dinitrotoluenes, and the remainder con ing explosives have been of lower power than is 40 sists of trinitrotoluene and tetryl each in a sub frequently desirable. _ stantial proportion, the said mixture of isomeric The crystallisation of any nitro-aromatic com dinitrotoluenes being wholly liquid at temper pound on the freezing of the explosive results in atures approximately the melting point of ice and undesired changes in physical form even when being obtainable, for example, by nitration of the the nitro-aromatic compound or mixture is pres 45 so-called meta fraction of mononitrotoluene ob ent in the form of the solution or jelly obtained by tained as a by-product in the manufacture of dissolving nitrocellulose in it. Thus, the compo ortho and para nitrotoluene. sitions tend to stiffen up, so that what is originally Preferably the trinitrotoluene and the tetryl soft and gelatinous or plastic when ?rst made up are employed in approximately equal proportions, becomes hard and brittle on storage. Even slight 50 but as the percentage of the mixture of isomeric changes of temperature are liable to resultv in dinitrotoluenes in the aromatic nitrocompound, serious alterations in consistency of this kind in mixture is increased from the lower towards the the case of explosives containing trinitrotoluene upper limit, the ratio of amounts of tI‘iIIitI'OtOI‘... 2,407,597 3 4 uene and tetryl can be varied to an increasing then by means of a McRoberts’ mixer, the fol ingredients usual in explosive compositions, for instance nitrocellulose, oxidising salts, explosive Pentaerythritol tetranitrate ____________ __ 691/2 lowing ingredients: extent from equality without causing the mix Per cent. ture to deposit solid at a given low temperature. The above described mixture of aromatic For the manufacture of composite explosive nitro-compounds _____________________ __ 29 compositions the aforesaid low freezing aromatic 5 lasting soluble nitrocotton _____________ __ 1% nitro-compound mixture may be mixed with other The nitrocotton is at least to a considerable salts such as ammonium nitrate, metal powders extent dissolved in the mixture of aromatic ni and other solid reducing agents, liquid nitric es 10 tro-compounds at about 15° to 20° C. before the ters, solid nitric esters, trinitrotoluene, flame pentaerythritol tetranitrate is introduced and in quenching ingredients, organic bases and like sta the McRoberts mixer the temperature is advan bilisers, chromates and other sensitisers of ther tageously about 30° C. The resulting explosive mal decomposition, and the like. These low freez has a power approximately 90 per cent. of that ing aromatic nitro-compound mixtures have the 1: -of blasting gelatine and a velocity of detonation property of dissolving or gelatinising nitrocellu of approximately 8000 metres per second. lose, and plastic or gelatinous explosive composi Example 2 tions made from these two ingredients are insen sitive to detonation by the impact of a 0.303 Brit The mixture of isomeric dinitrotoluene is the ish service infantry ri?e bullet ?red from 40 same as in Example 1. 80 parts of this mixture yards against the explosive composition backed are incorporated with 10 parts trinitrotoluene by a steel plate. If it is so desired it may be made and 10 parts tetryl by the method described in still more insensitive by the inclusion in the com Example 1. position of a non-explosive nitrocellulose plasti Example 3 ciser miscible with the aromatic nitro-compound 25 The procedure is the same as in Example 1' mixture such as dibutyl phthalate or tricresyl except that the proportions used are: phosphate, but the power of the composition is Parts correspondingly reduced. Liquid mixture of isomeric dinitrotoluenes" 80 For instance in the manufacture of gelatine ex plosives of high power containing suspended 30 Trinitrotoluene _________________________ __ highly explosive solids such as solid nitric esters or the like, it is frequently desirable to employ Tetryl _________________________________ __ l5 5_ Example 4 as the mixture of aromatic compounds one con The procedure is the same as in Example 1 taining a proportion of the dinitrotoluene mixture approximating the upper limit, in order to mini 35 except that the proportions used are: Parts mize the sensitiveness of the resulting explosive Liquid mixture of isomeric dinitrotoluenes“ 85 to friction and shock. Alternatively, or in addi tion, a non-explosive nitrocellulose plasticiser miscible with the aromatic nitro-compound mix Trinitrotoluene _________________________ __ l0 Tetryl _________________________________ __ 5 ture may be included in the composition. On the Example 5 other hand, if the solid ingredients of the gela The procedure is the same as in Example 1 tine explosive are of a non-explosive character, for instance organised carbonaceous ingredients 7 except that the proportions used are: Parts‘ and alkali metal nitrates, or include as suspended explosive ingredients only materials that are dif 45 Liquid mixture of isomeric dinitrotoluenes" 85' Trinitrotoluene _________________________ __ 5 ficult to detonate by friction or shock for instance Tetryl _________________________________ __ 10 ammonium nitrate, it may be desirable that the mixture of the nitro-aromatic compounds used Example 6 should contain a proportion of the dinitrotoluene mixture approximating the minimum in order 5:0 The mixture of isomeric dinitrotoluenes is the that the gelatine explosive should have as high same as in Example 1, and forms approximately a power as possible. "72 per cent. of the combined weight of the aro-. The invention is illustrated by the following matic nitro-compounds, whereof the remainder. examples, in which the parts are parts by weight. consists of trinitrotoluene and tetryl in equal pro.-.. 55 portions. The mixture is made in a similar fash Example 1 ion to that described in Example 1. 83 parts of ' The mixture of isomeric dinitrotoluenes used the nitro-aromatic compound mixture, consisting is one that commences to freeze at approximately of the dinitrotoluene isomers, the trinitrotoluene —3.5° C., and was obtained by nitration of the and tetryl, are diluted with 17 parts dibutyl so-called meta fraction of mononitrotoluene ob phthalate. A plastic explosive is made from this tained as a by-product in the manufacture of mixture by mixing together, ?rst by hand and ortho and para nitrotoluene. Into ‘71.6 parts of then by means of a McRoberts mixer the follow ing ingredients: this mixture contained in a jacketed pan pro— vided with a mechanical stirrer there are added Per cent. 14.2 parts ?ake trinitrotoluene and 14.2 parts 65 The above mixture containing the aromatic tetryl crystals, and the mixture is warmed to compounds and the dibutylphthalate_____ 29.5 about 60° C. and stirred to hasten the solution 1/2-second industrial nitrocellulose ~12% ni of the solids. The resulting liquid explosive mix trogen content ________________________ __ 3.6 ture can be stored inde?nitely at a temperature Blasting soluble nitrocotton _____________ __- 0.4- 1 of —10° C. or even somewhat lower without 70 Pentaerythritol tetranitrate _____________ __ 66.5 -' commencing to solidify even when it is seeded with a solid mixture of trinitrotoluene and tetryl. A plastic explosive can be made from this’ mixture by mixing together ?rst by hand, and _ The nitrocelluloses are partly dissolved in the _ liquid mixture at about 15 to 20° C. before the pentaerythritol tetranitrateis introduced. In the McRoberts mixer the temperature is_advanta-~. geously about 30° C. The resulting explosive has 2,407,597 5 a power approximately 82 per cent. that of blast 6 ing aromatic nitrc-compound mixture whereof ing gelatine, and is insensitive to detonation by about 70 to 85 per cent consists of a mixture of the impact of a 0.303 British service infantry ri?e isomeric dinitrotoluenes Wholly liquid at temper bullet ?red from 40 yards against the explosive atures approximating the melting point of ice, composition backed by a steel plate. Cl and the remainder consists of at least 5 per cent The mixtures of isomeric dinitrotoluenes, tri each of trinitrotoluene and tetryl, nitrocellulose nitrotoluene and tetryl made in accordance with gelatinised in said aromatic nitro-compound mix Examples 2 to 6 can be stored inde?nitely at —10° ture, and a non-explosive nitrocellulose plasticizer C. Without commencing to solidify, and the plastic miscible with said aromatic nitro-compound mix gelatine explosives made from them remain plas 10 ture. tic when stored inde?nitely at that temperature, 4. A gelatine explosive comprising a low-freez as does that prepared according to Example 1. ing aromatic Intro-compound mixture whereof These pentaerythritol plastic gelatines can be ini about 70 to 85 per cent consists of a mixture of tiated by means of commercial detonators, and isomeric dinitrotoluenes wholly liquid at temper are well suited for demolition work. 15 atures approximating the melting point of ice, and Having now particularly described and ascer the remainder consists of at least 5 per cent each tained the nature of our said invention, and in of trinitrotoluene and tetryl, and nitrocellulose what manner the same is to be performed, we de dissolved in said low-freezing aromatic nitro clare that what We claim is: com-pound mixture. 1. A low-freezing aromatic nitro-compound 20 5. A gelatine explosive comprising a low-freez mixture whereof about 70 to 85 per cent consists ing aromatic nitro-compound mixture whereof of a mixture of isomeric dinitrotoluenes Wholly about 70 to 85 per cent consists of a mixture of liquid at temperatures approximating the melt isomeric dinitrotoluenes wholly liquid at temper atures approximating the melting point of ice, ing point of ice, and the remainder consists of at least 5 per cent each of trinitrotoluene and tetryl. 25 and the remainder consists of at least 5 per cent 2. A low-freezing aromatic nitro-compound each of trinitrotoluene and tetryl, and nitrocellu mixture whereof about '70 to 85 per cent consists lose dissolved in said low-freezing aromatic nitro of a mixture of isomeric dinitrotoluenes Wholly compound mixture, pentaerythritol tetranitrate liquid at temperaures approximating the melting suspended in said solution of nitrocellulose in the point of ice, and the remainder consists of tri aromatic mixture. nitrotoluene and tetryl in approximately equal HAROLD R. WRIGHT. proportions. 3. A gelatine explosive comprising a low-freez JAMES TAYLOR.