U.S. patent application number 13/905558 was filed with the patent office on 2016-04-28 for pyrotechnic yellow smoke compositions based on solvent yellow 33.
The applicant listed for this patent is Gary Chen, Robert Gilbert, JR., Jared D. Moretti, Jesse J. Sabatini. Invention is credited to Gary Chen, Robert Gilbert, JR., Jared D. Moretti, Jesse J. Sabatini.
Application Number | 20160115090 13/905558 |
Document ID | / |
Family ID | 55791436 |
Filed Date | 2016-04-28 |
United States Patent
Application |
20160115090 |
Kind Code |
A1 |
Moretti; Jared D. ; et
al. |
April 28, 2016 |
PYROTECHNIC YELLOW SMOKE COMPOSITIONS BASED ON SOLVENT YELLOW
33
Abstract
A yellow smoke composition useful in hand held signals, such as
the U.S. Army M194 yellow smoke parachute signal; which composition
contains the nontoxic, environmentally safe, quinoline solvent
yellow 33 color agent and critically exhibits the requisite dense
yellow smoke for the requisite 9 to 18 second burn time upon use.
Further, this inventive yellow smoke composition can be used in
current metal tubes and in other media, such as biodegradable
cardboard tubes.
Inventors: |
Moretti; Jared D.;
(Randolph, NJ) ; Sabatini; Jesse J.; (Denville,
NJ) ; Chen; Gary; (Succasunna, NJ) ; Gilbert,
JR.; Robert; (Dover, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Moretti; Jared D.
Sabatini; Jesse J.
Chen; Gary
Gilbert, JR.; Robert |
Randolph
Denville
Succasunna
Dover |
NJ
NJ
NJ
NJ |
US
US
US
US |
|
|
Family ID: |
55791436 |
Appl. No.: |
13/905558 |
Filed: |
May 30, 2013 |
Current U.S.
Class: |
102/334 ; 149/2;
149/79; 149/84 |
Current CPC
Class: |
C06D 3/00 20130101 |
International
Class: |
C06B 23/00 20060101
C06B023/00; C06D 3/00 20060101 C06D003/00 |
Goverment Interests
FEDERAL RESEARCH STATEMENT
[0001] The inventions described herein may be manufactured, used
and licensed by, or for, the U.S. Government, for U.S. Government
purposes.
Claims
1. A HHS yellow smoke composition having a burn time of about 15
seconds, comprising: 1. a mixture of about 34.5 weight percent of
an oxidizer, wherein the oxidizer is potassium chlorate; 2. about
21.5 to about 22.0 weight percent of a fuel, wherein the fuel is
sucrose; 3. about 36 to about 37 weight percent of quinoline yellow
ss; 4. about 5.5 weight percent of a coolant, wherein the coolant
is hydromagnesite; 5. about 0 to about 1.0 weight percent of a
lubricant, wherein the lubricant is stearic acid; 6. about 0 to
about 1.0 weight percent of a binder, wherein the binder is
polyvinyl alcohol; 7. wherein, when the mixture is compressed into
a smoke pellet.
2. The HHS yellow smoke composition of claim 1, wherein 1. the
oxidizer is potassium chlorate; 2. the fuel is sucrose; 3. the
coolant is hydromagnesite; 4. the lubricant is stearic acid; and 5.
the binder is polyvinyl alcohol.
3. The HHS yellow smoke composition of claim 2, wherein the binder
is nitrocellulose.
4. The HHS yellow smoke composition of claim 1, wherein the mixture
is compressed at from about 4,000 to about 12,000 pound dead load,
for a period of about 4 seconds, to form the smoke pellet.
5. The HHS yellow smoke composition of claim 1, wherein about 0 to
about 0.5 weight percent of an anticaking agent is included in the
mixture and an equal quantity of the fuel is removed.
6. The HHS yellow smoke composition of claim 6, wherein the
anticaking agent is hydrophobic fumed silica.
7. The HHS yellow smoke composition of claim 4, wherein the
composition is compressed inside of a biodegradable cardboard tube.
Description
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to hand held signal
pyrotechnic smoke compositions, and more particularly, to such an
compositions that are free of the conventional, but toxic yellow
smoke agents Vat Yellow 4 (dibenzochrysenedione) and benzanthrone,
and still continue to provide the requisite density, burn time, and
good color quality.
[0004] 2. Background Art
[0005] Hand held signal (HHS) pyrotechnic smoke compositions are
useful for multiple military purposes--including signaling troop
locations or distress, during combat or training operations, or to
serve as a beacon for target or landing zone marking. One such
pyrotechnic smoke formulation is contained within the US Army M194
HHS--which HHS is launched via a rocket to a height of about 725
feet, at which point the signal is ignited. The M194 HHS provides a
dense, highly visible yellow smoke as it falls back to earth via
parachute--burning for 9 to 18 seconds (ideally about 13 to about
15 seconds), while producing the desired yellow smoke during this
period, before burnout at about 500 to 600 feet. Unfortunately, the
current M194 HHS yellow smoke formulation contains two toxic
anthraquinone dyes, namely Vat Yellow 4 (aka (dibenzochrysenedione)
and benzanthrone. Benzanthrone is a known dermal sensitizer, and is
reported as causing liver and nervous system damage; plus, it is
also known to be highly toxic to aquatic life. Vat Yellow 4, felt
to contain small but significant amounts of dibenzochrysene (an
extremely potent carcinogen) is classified as a Group 3 material by
the International Agency for Research on Cancer (IARC)--because of
evidence of its potential carcinogenic impact remains
unsubstantiated.
[0006] In the current M194 pyrotechnic formulation, the dense
yellow smoke is formed by the cost effective reduction-oxidation
(redox) reaction of relatively inexpensive potassium chlorate (an
oxidizer), with sugar (a fuel, or reducing agent)--which generates
significant heat. The heat, in turn, causes the dye molecules, i.e.
the VAT Yellow 4 and benzanthrone--to enter the gas phase (via
sublimation) and begin to disperse. After dispersion of the dye
molecules, contact with the cool ambient air causes them to
condense back to the solid phase, helped by the presence of sodium
bicarbonate, which functions as an evaporative cooling agent.
Lastly, the formulation contains a binder to "glue" it together,
i.e. vinyl alcohol acetate resin (VAAR).
[0007] As the binder in the current yellow smoke M194 formulation
is available only in a solvent media--the manufacturing process
requires that this solvent be driven-off prior to the consolidation
of the yellow smoke formulation and its packing into a steel
canister within the M194 HHS.
[0008] An alternative yellow pyrotechnic smoke formulation has been
developed for the simulation of the smoke signature related to
ground-launched missiles--part of a Battle Effects Simulator (BES)
system. These yellow smoke formulations use an alternative yellow
smoke agent, quinoline yellow spirit solution, also commonly known
as quinoline yellow ss or solvent yellow 33, in combination with
potassium chlorate (the oxidizer), sugar (the fuel/reducing agent),
magnesium carbonate (a coolant), stearic acid (a lubricant), and
VAAR (a binder). However, while these alternative BES yellow smoke
formulations are much safer and more environmentally friendly than
the M194 yellow smoke formulations--the burn times are far outside
that required for the M194 HHS application, i.e about 37.5 seconds
(over twice the maximum time allowed for the M194 yellow smoke
application of 9 to 18 seconds).
[0009] Therefore, there is a need in the art for a replacement M194
HHS yellow smoke composition that continues to utilize the
relatively inexpensive potassium chlorate and sugar redox reaction,
and contains an alternative yellow smoke agent that is non-toxic
and environmentally safe; which composition will burn for the
requisite 9 to 18 seconds, while producing the desired dense,
highly visible yellow smoke. Further, there is also a need in the
art for an all solid ingredient alternative M194 HHS smoke
composition that will rot require any solvent to be driven off
during its manufacture--thereby simplifying and making the
manufacturing process more effective, efficient, and
economical.
SUMMARY OF INVENTION
[0010] In order to overcome the above stated problems of the prior
art--the present inventive HHS yellow pyrotechnic smoke formulation
preferably contains all solid, powder ingredients which are easily
combined via a conventional dry-tumble process--the ingredients
being: potassium chlorate (KClO.sub.3), an oxidizing agent; sugar
(sucrose), a fuel (reducing agent); solvent yellow 33 (SY33,
otherwise known as quinoline yellow ss, or as D&C Yellow No.
11), the yellow smoke agent; hydromagnesite (Mg5(CO3)4(OH)2.4H2O),
a coolant; stearic acid, a lubricant; hydrophobic fumed silica
(available from the Cabot Corporation, under the trademark
Cab-O-Sil.RTM.), an anti-caking agent; and polyvinyl alcohol (PVA),
a binder. These ingredients provide an inventive yellow smoke
formulation wherein a redox reaction of the potassium chlorate and
sugar forms potassium chloride, carbon dioxide, water vapor, and
soot/carbon--which reaction is exothermic. This exothermic reaction
releases sufficient heat to cause the yellow smoke agent SY33 to
sublimate, disperse over a wide area, and then condense into the
desired dense, highly visible yellow smoke. Further, and most
importantly, the burn time is within the 9 to 18 second desired,
required, smoke production time, when the inventive formulation is
compressed into a smoke pellet usable in an M194 HHS.
[0011] In an alternative embodiment of the present invention, a
small quantity of fumed silica (also known as pyrogenic silica or
Cab-O-Sil.RTM.),) can be substituted for an equal quantity of the
fuel, sugar--the silica acting as an anticaking agent--to aid in
the flowability of the inventive formulation during its handling,
transport, and packing into the desired HHS container.
[0012] If desired, the inventive formulation can contain the
alternative binders polyvinyl alcohol (PVA) and/or nitrocellulose
(NC). The NC alternative embodiment, wherein the nitrocellulose
ingredient is contained within solvent media, will require that
after the ingredients are added to the mixture, the resulting now
wet mixture will have to be dried in a dryer or oven. When the
preferred alternative binder polyvinyl alcohol is utilized in the
inventive mixture, the resulting dry mix is useful for the subject
application as is, i.e. no drying step is required.
[0013] Additional features and advantages of the present invention
will be set forth in, or are apparent from, the detailed
description of preferred embodiments thereof which follows.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a cross-sectional diagram of the current U.S. Army
M194 HHS; regarding which HHS, the inventive yellow smoke "candle"
may be substituted with that of the present invention.
[0015] FIG. 2 is the structural chemical formulation of solvent
yellow 33, SY33, the preferred non-toxic yellow dye material useful
in the present invention.
[0016] FIG. 3 is a cross-sectional view of a yellow smoke
formulation test prototype using the present inventive formulation
therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The present inventive HHS yellow pyrotechnic smoke
composition is preferably a mixture of solid materials, including
about 34.5 weight percent of potassium chlorate (KClO.sub.3), an
oxidizing agent; about 21.5 to about 22.0 weight percent of a sugar
(sucrose), a fuel (reducing agent); about 36 to about 37 weight
percent of solvent yellow 33 (SY33, also known as quinoline yellow
ss, or as D&C Yellow No. 11), the yellow smoke agent; about 5.5
weight percent hydromagnesite
(Mg.sub.5(CO.sub.3).sub.4(OH).sub.2.4H.sub.2O), a cooling agent;
about 0 to about 1.0 weight percent stearic acid, a lubricant; and
about 0 to about 0.5 weight percent hydrophobic fumed silica, an
anti-caking agent. To this mixture of solid powdered materials, a
binder or combination of binders may be added, where the most
preferred binder is about 0 to about 1.0 weight percent polyvinyl
alcohol (PVA), also a solid (such that the resulting mixture need
only be dry-tumbled to be completed).
[0018] As stated above, in an alternative embodiment of the present
invention, a smal quantity, about 0.5 wt. %, of fumed silica (also
known as pyrogenic silica) can be substituted for an equal quantity
of the fuel, sugar--the silica acting as an anticaking agent--to
aid in the flowability of the inventive formulation during its
handling, transport, and packing into the desired HHS
container.
[0019] An alternative binder useful in the present invention
includes nitrocellulose (NC)--but, this alternative binder is
standardly available in a liquid form, i.e. in a solvent
media--such that about 10% by weight must be added and then the
solvent driven-off in an oven or dryer--whereby the final quantity
of the nitrocellulose is at the desired about 0 to about 1.0 weight
percent of the total inventive yellow smoke formulation.
[0020] The particular yellow smoke agent useful in the present
invention is, as stated above, solvent yellow 33--which material is
abbreviated as SY33, and also known as quinoline yellow ss, or as
D&C Yellow No. 11. As shown in FIG. 2, the chemical structure
of SY33 consists of a quinoline carbon skeleton and may be
described as 2-(2-quinolyl)-1,3-indandione. This material is
conventionally used as a coloring agent in topical drugs and
cosmetics, in spirit lacquers, acrylic resins, polystyrene,
polycarbonates, polyamides and to color hydrocarbon solvents. Most
importantly, SY33 has been deerred admissible by the U.S. Army
Public Health Command (PHC) in colored smoke formulations and this
dye is presently used in M18 smoke grenade production. Also,
inhalation studies of SY33 as a smoke dye indicates that this
compound is cleared from the lungs very rapidly.
[0021] The specification of the various ingredients in the above
detailed inventive formulation preferably meet the criteria and
specifications shown in Table 1 below.
TABLE-US-00001 TABLE 1 Preferred chemical specifications for the
ingredients useful in the present invention. Ingredient
Specification (US Military Specifications) Potassium chlorate
(KClO.sub.3) MIL-P-150D, Grade B, Class 7 Sugar (sucrose)
MIL-AA-20135D, Type 1, Style C Solvent yellow 33
MIL-DTL-51485B(EA), Type II, from Nation Ford Chemical Sodium
bicarbonate Technical grade, from Hummel Croton (NaHCO.sub.3)
Hydromagnesite Technical grade, from Pine Bluff Arsenal
(Mg.sub.5(CO.sub.3).sub.4(OH).sub.2.cndot.4H.sub.2O) Stearic acid
MIL-S-271B Hydrophobic fumed silica From Cabot (Cabosil) VAAR
MIL-V-50433 Polyvinyl alcohol Molecular weight range: 77,000-79,000
g/mol Nitrocellulose Technical grade, from Alliant Techsystems
[0022] In preparing the inventive yellow smoke formulation, the
potassium chlorate was initially oven dried overnight at 140
degrees F.--to ensure its dryness. Then, in the case of the
inventive formulation embodiments containing only solid
ingredients, the potassium chlorate and other ingredients were
tumbled end-over-end in conductive plastic containers for 60 min;
while, those containing wet NC were blended in a Hobart mixer for
30 min. Dry-tumbled formulations were taken directly to loading
operations without further processing, while NC-based formulations
were oven-cured overnight at 140.degree. F. prior to loading.
Following blending, the dry mixture was hydraulically pressed into
kraft cardboard tubes--which is a distinct advantage over
formulations of the prior art. Specifically, the current inventive
yellow smoke formulation can be consolidated and delivered in the
prior art steel canister, or in other canister materials, such as
an aluminum, or even cardboard canisters--and still give the
requisite smoke density, color, and duration of burn. And, after
consolidation and coating with first-fire composition, the pressed
pellets are ready for evaluation/testing.
[0023] The inventive formulations were tested and proved to meet
the requisite smoke density, color, and burn time in biodegradable
cardboard tubes (as shown in FIG. 3)--using static ignition tests.
Referring to FIG. 3, a 70-gram, cylindrical smoke pellet was
pressed in 2-3 increments (at about 4,000 to about 12,000 pound
dead load, for about 4 seconds dwell time) inside of a Kraft paper
tube--to form a smoke candle. A thin coat of igniter slurry
(first-fire composition) was applied to the top surface (shallow
recess on the left side of the pressed smoke composition) and
tapered inner bore of the pellet. After oven-curing at 140.degree.
F. for 16 hours, the pellet (smoke candle) was ready to be
ignition-tested and its resulting smoke density, color, and burn
time evaluated.
[0024] The inventive formulations were tested against the current
BES yellow smoke formulation, which was considered a baseline, as
it is similar in many respects; but, as stated, has a burn time
that is totally unacceptable (twice the maximum allowed rate of 18
seconds). The results of the tests are shown in Table 2, and the
summarized below: [0025] (1) replacement of the binder present in
BES--samples designated 12 and 14, or eliminating the binder
altogether, designated 13--resulted in burn times on the outer cusp
of the requirement .about.18 s in each case--and were judged not
acceptable; [0026] (2) increasing oxidizer content in 5 wt. %
increments, designated 15 and 16, yielded burn times more-or-less
equivalent to that of the BES control--i.e. not acceptable; [0027]
(3) increasing dye content in 5 wt. % increments, designated 17 and
18 yielded burn times that were both longer than the BES
control--i.e. not acceptable; [0028] (4) substituting the coolant
NaHCO.sub.3 for hydromagnesite
(Mg.sub.5(CO.sub.3).sub.4(OH).sub.2.4H.sub.2O) the in the BES
control, was met with a significant improvement in burn time,
demonstrated by burning of the formulation designated 19--however,
not to the extent as to be acceptable. This coolant effect was also
explored in the alternative formulations, designated 22, 24, and
25, which were identical to formulations designated 12, 13, and 14,
again only using NaHCO.sub.3 instead of
(Mg.sub.5(CO.sub.3).sub.4(OH).sub.2.4H.sub.2O) as a coolant. These
too, unfortunately, burned outside the acceptable/target time
range; [0029] (5) a mix identical to 12 only with 2 wt. % NC,
designated 23, gave a burn time that was still too long; despite
efforts to reduce burn time and the improvements exhibited by 12,
13, and 14, more formulation development was necessary to fit more
comfortably within the target time range (ideally 13-15 seconds);
[0030] (6) tests at 10.5 wt. % coolant weight percentage for all
four binder systems (NC, PVA, binder-free, and VAAR) designated 89
through 117, and 118 through 121 proved unacceptably long, with the
(Mg.sub.5(CO.sub.3).sub.4(OH).sub.2.4H.sub.2O)-based formulations
generally burning faster than the NaHCO.sub.3-based formulations;
[0031] (7) however, surprisingly, three formulations in the
grouping designated 27, 28, and 29, at 5.5 wt. %
(Mg.sub.5(CO.sub.3).sub.4(OH).sub.2.4H.sub.2O) met the target burn
time range, each at about 15 seconds; but [0032] (8) the
alternative NaHCO.sub.3-based formulations, designated 26 through
64 at this 5.5 wt. % coolant level--still burned outside the target
range; [0033] (9) further, and also surprisingly, as the coolant
level was progressively lowered, while we expected to see even
shorter burn times by cutting the coolant level to 2.5 wt. % in the
grouping designated 77 through 80, and 81 through 84--these
formulations, however, generally gave smoke plumes of drastically
reduced color quality. Apparently, the coolant level in this last
grouping was not sufficiently high to moderate the reaction
temperature and to suppress flaming.
TABLE-US-00002 [0033] TABLE 2 Chemical composition and performance
of invented yellow smoke formulations.sup.a, 27, 28, 29, and
similar compositions which failed to meet the burn time standard
Wt. % Burn Ref. Wt. % Wt. % Wt. % Wt. % Wt % fumed Time No.
KClO.sub.3 Sugar Coolant.sup.c NaHCO.sub.3 SY 33 Binder silica
(sec) BES 29.5 22 15.5 31 VAAR 38 12 29.5 22 15.5 31 NC 19 13 29.5
22 15.5 32 None 17 14 29.5 22 15.5 31 PVA 18 15 29.5 27 10.5 31
VAAR 42 16 29.5 32 5.5 31 VAAR 34 17 29.5 22 10.5 36 VAAR 43 18
29.5 22 5.5 41 VAAR 45 19 29.5 22 15.5 31 VAAR 22 22 29.5 22 15.5
31 NC 30 24 29.5 21.5 15.5 31 PVA 0.5 42 25 29.5 21.5 15.5 32 None
0.5 36 23 29.5 22 14.5 31 NC (2%) 25 89 29.5 22 10.5 36 NC 23 90
29.5 21.5 10.5 37 None 0.5 34 116 29.5 21.5 10.5 36 PVA 0.5 33 117
29.5 22 10.5 36 VAAR 86 118 29.5 22 10.5 36 NC 49 119 29.5 21.5
10.5 37 None 0.5 42 120 29.5 21.5 10.5 36 PVA 0.5 33 121 29.5 22
10.5 36 VAAR 65 27 34.5 22 5.5 36 NC 16 28 34.5 21.5 5.5 37 None
0.5.sup.b 15 29 34.5 21.5 5.5 36 PVA 0.5.sup.b 15 63 34.5 22 5.5 36
VAAR 49 26 34.5 22 5.5 36 NC 24 33 34.5 21.5 5.5 37 None 0.5 21 34
34.5 21.5 5.5 36 PVA 0.5 20 64 34.5 22 5.5 36 VAAR 88 77 34.5 22
2.5 39 NC 21 78 34.5 21.5 2.5 40 None 0.5 24 79 34.5 21.5 2.5 39
PVA 0.5 17 80 34.5 22 2.5 39 VAAR 55 81 34.5 22 2.5 39 NC 28 82
34.5 21.5 2.5 40 None 0.5 26 83 34.5 21.5 2.5 39 PVA 0.5 26 84 34.5
22 2.5 39 VAAR 54 .sup.aAll formulations contain 1 wt. % stearic
acid as a lubricant and, except those noted otherwise or those
binder-free, 1 wt. % binder (NC or PVA or VAAR - as stated).
.sup.bThe fumed silica, e.g. Cab-O-Sil .RTM. available from the
Cabot Corporation, can be omitted entirely and the sugar content
increased correspondingly to 22 wt. % with no difference in
performance. .sup.cThe coolant being: hydromagnesite
(Mg.sub.5(CO.sub.3).sub.4(OH).sub.2.cndot.4H.sub.2O).
[0034] The procedure used in the static ignition tests, whose
results are detailed above, involved using the cylindrical smoke
pellets, or smoke candles, (produced as detailed above), wherein
the pellet were clamped vertically with the top slurry-coated end
facing up. The head of an electric match was placed on the top
slurried end. After passing an energy of 2 volts through the
electric match, the resulting spit of the electric match lights the
igniter slurry. The heat from this ignition event then initiates a
reduction-oxidation reaction between the fuel (sugar) and the
oxidizer (potassium chlorate) in the tested pressed smoke
compositions. The burning of the pressed pellet propagated in a
core-burning fashion, from top-down and from inside-out (but
surprisingly, not bottom-up). The burn times, linear burning rates,
and mass consumption rates were measured for all smoke candles
tested--and the results presented above.
[0035] Although the invention has been described above in relation
to preferred embodiments thereof, it will be understood by those
skilled in the art that variations and modifications can be
effected in these preferred embodiments without departing from the
scope and spirit of the invention.
* * * * *