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Патент USA US2407597

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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.
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