CA1056688A - Pour-castable smoke compositions - Google Patents
Pour-castable smoke compositionsInfo
- Publication number
- CA1056688A CA1056688A CA259,735A CA259735A CA1056688A CA 1056688 A CA1056688 A CA 1056688A CA 259735 A CA259735 A CA 259735A CA 1056688 A CA1056688 A CA 1056688A
- Authority
- CA
- Canada
- Prior art keywords
- weight
- smoke
- pour
- castable
- composition
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
- C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
- C06B45/04—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive
- C06B45/06—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component
- C06B45/10—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component the organic component containing a resin
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06D—MEANS FOR GENERATING SMOKE OR MIST; GAS-ATTACK COMPOSITIONS; GENERATION OF GAS FOR BLASTING OR PROPULSION (CHEMICAL PART)
- C06D3/00—Generation of smoke or mist (chemical part)
Abstract
ABSTRACT OF THE DISCLOSURE
A pour-castable smoke-producing composition for use in smoke generators which has a solids loading of the order of 78-86% by weight ant which incorporates an inexpensive rubber binder. The composition comprises 30-50% by weight of a granular organic dye having an average particle size in the range 300-700 microns, 20-35%
by weight of an oxidizing agent, 5-20% by weight of a fuel and 14-22%
by weight of a binder. Optionally, up to about 5% by weight of a cooling agent and up to about 3% by weight of a combustion catalyst may be added. The composition may be pour-cast into small diameter containers, cured to vulcanize the binder and then incorporated into smoke generators of conventional design.
A pour-castable smoke-producing composition for use in smoke generators which has a solids loading of the order of 78-86% by weight ant which incorporates an inexpensive rubber binder. The composition comprises 30-50% by weight of a granular organic dye having an average particle size in the range 300-700 microns, 20-35%
by weight of an oxidizing agent, 5-20% by weight of a fuel and 14-22%
by weight of a binder. Optionally, up to about 5% by weight of a cooling agent and up to about 3% by weight of a combustion catalyst may be added. The composition may be pour-cast into small diameter containers, cured to vulcanize the binder and then incorporated into smoke generators of conventional design.
Description
Thls lnventlon relates to smoke-producing compositions for use in smoke generators. More particularly, this invention relates to pour-castable compositions with a goli~g loading of 78-~6~ by wcight and an inexpensive rubber binder.
Because smoke formulationc are relatively complex, generally containlng an oxldizer, fuel, dye,and other additives, and contain very large proportions of very flne, low density dye particles, large percent-ages, of the order of 25%, of polymeric blnders are required to achieve castability. Because of the poor combustion properties of most polymers, their presence has, in general, a detrimental effect upon the burn rate and smoke volume output. Tamp castable mi~tures have, therefore, gen~
erally been used as the pGlymer concentration~ canbe reduced to 8-20%.
Although these ccmpositions are not generally pour-castable, they are simpler to prepare and safer to process than the conventional powder form-ulations. This represents a considerable advance in the state of the art of pyrotechnic technology as formerly dry blending, granulation and incremental pressing using remote-controlled presses were required. At each of theae steps the ever present fine dye powdercoated machinery, personnel and proce66ing rooms, whereas with poly~er bonded formulations, wet blending, wet processing and wet loading eliminates these undesirable features as well as the costly remote-controlled loading process. Cast-able formulations can be easily loaded into any shape or configuration thus allowing greater flexiblity in the design of munition containers or pyrotechnic candle layouts. Their inherent reduced sensitivity to impact, friction, electric spark and moisture, as well as their excellent mechan-ical properties, make castable formulations particularly attractive from a user point of view and places them far above conventional pressed powder formulations in terms of these properties.
Commercially available dyes heretofore used in smoke-producing compositions have only been available in the form of very fine powders of the order of 10 to 15 microns, which limits the solids loading of the -1- ~
1056~i8B
co~position to about 75%. At loadings of 75% and above, the Yiscosity of the mixture exceedsl~ kP and pour-casting of the composition becomes impossible. It ls, of course, feasible to produce composltions exceedlng 7S% solids loading, but such compositions must bs packed and compressed into the smoke generator containers, which is costly and time-consumlng.
It will, of course, be appreciated that as hlgh a solids loadlng as possible, compatible with the binder syatem and burning characteristics ; is desirable 80 as to produce as much smoke as possible from a given ;~ volume of the compoqition. It is also deslrable that the composition shall burn quickly and that the decompositlon temperature shall be as low as possible so as to reduce the probability of starting grass or bush fires when the smoke generators are operated in a search and rescue role.
It is an object, therefore, of the present invention to provide a relatively inexpensive composite pour-castable smoke~producing composi-tion with a high solids loading, a reduced decomposition temperature and an improved combustion rate together with a rubber binder conventionally used by the composite propellant industry.
By one aspect of this invention, there is provided a pour-castable smoke-producing composition containing 30-50% by weight of a granular organic dye having an average particle size ln the range 300-700 microns, 20-35% by weight of an oxidizing agent, 5-20% by weight of a fuel9 and 14-22% by weight of a binder.
By a second aspect of this invention, there is provided a smoke generator comprising a casing which contains a smoke-producing composition containing 30-50% by weight of a granular organic dye having an average particle size in the range 300-700 microns, 20-35% by weight of an oxidiz-ing agent, 5-20% by weight of a fuel, and 14-22% by weight of a binder, together with a starter for ignitin8 said smoke-producing composition and !, means for firlng said ~tarter.
By yet another aspect of this invention there is provide~ a pour-castable starter composition for igniting a smoke-producing composition,
Because smoke formulationc are relatively complex, generally containlng an oxldizer, fuel, dye,and other additives, and contain very large proportions of very flne, low density dye particles, large percent-ages, of the order of 25%, of polymeric blnders are required to achieve castability. Because of the poor combustion properties of most polymers, their presence has, in general, a detrimental effect upon the burn rate and smoke volume output. Tamp castable mi~tures have, therefore, gen~
erally been used as the pGlymer concentration~ canbe reduced to 8-20%.
Although these ccmpositions are not generally pour-castable, they are simpler to prepare and safer to process than the conventional powder form-ulations. This represents a considerable advance in the state of the art of pyrotechnic technology as formerly dry blending, granulation and incremental pressing using remote-controlled presses were required. At each of theae steps the ever present fine dye powdercoated machinery, personnel and proce66ing rooms, whereas with poly~er bonded formulations, wet blending, wet processing and wet loading eliminates these undesirable features as well as the costly remote-controlled loading process. Cast-able formulations can be easily loaded into any shape or configuration thus allowing greater flexiblity in the design of munition containers or pyrotechnic candle layouts. Their inherent reduced sensitivity to impact, friction, electric spark and moisture, as well as their excellent mechan-ical properties, make castable formulations particularly attractive from a user point of view and places them far above conventional pressed powder formulations in terms of these properties.
Commercially available dyes heretofore used in smoke-producing compositions have only been available in the form of very fine powders of the order of 10 to 15 microns, which limits the solids loading of the -1- ~
1056~i8B
co~position to about 75%. At loadings of 75% and above, the Yiscosity of the mixture exceedsl~ kP and pour-casting of the composition becomes impossible. It ls, of course, feasible to produce composltions exceedlng 7S% solids loading, but such compositions must bs packed and compressed into the smoke generator containers, which is costly and time-consumlng.
It will, of course, be appreciated that as hlgh a solids loadlng as possible, compatible with the binder syatem and burning characteristics ; is desirable 80 as to produce as much smoke as possible from a given ;~ volume of the compoqition. It is also deslrable that the composition shall burn quickly and that the decompositlon temperature shall be as low as possible so as to reduce the probability of starting grass or bush fires when the smoke generators are operated in a search and rescue role.
It is an object, therefore, of the present invention to provide a relatively inexpensive composite pour-castable smoke~producing composi-tion with a high solids loading, a reduced decomposition temperature and an improved combustion rate together with a rubber binder conventionally used by the composite propellant industry.
By one aspect of this invention, there is provided a pour-castable smoke-producing composition containing 30-50% by weight of a granular organic dye having an average particle size ln the range 300-700 microns, 20-35% by weight of an oxidizing agent, 5-20% by weight of a fuel9 and 14-22% by weight of a binder.
By a second aspect of this invention, there is provided a smoke generator comprising a casing which contains a smoke-producing composition containing 30-50% by weight of a granular organic dye having an average particle size in the range 300-700 microns, 20-35% by weight of an oxidiz-ing agent, 5-20% by weight of a fuel, and 14-22% by weight of a binder, together with a starter for ignitin8 said smoke-producing composition and !, means for firlng said ~tarter.
By yet another aspect of this invention there is provide~ a pour-castable starter composition for igniting a smoke-producing composition,
-2-:: .
S6~8~
~~ compri~ing 25~35% by weight o~ a granular organic dye having an average ;~
particle size in the range 300-700 microns, 30-45% by weight of an oxid-izing agent, 5-20% by weight of a fuel and 18-25% by weight of a binder.
In the drawlng~ accompanying this specification, Figure 1 1~ a cross-sectional view of a amoke generator - incorporating the compositions accordlng to the pregent invention and : Figure 2 i~ a cros~-sectlonal view of an alternative tes~ ~moke generator incorporating the compositiong according to the present invention. ;~
Becsuse of safety, processing and cost considerations, additional restrictive properties whlch must be taken into account in the preparation of castable formulations include:
~ .,: - .
- a) polymer make-up chemicals must be available at low cost;
. . : .
b) compositions should be processable in low co~t equipment (i.e.
mix viscosities must be sufficiently low);
c) in8redients must be compatible during mixing, both from a chemical ~ ;
and an explosiveg sa~ety point of view;
d) to achieve pour-castable formulations, the end of-mix (EOM) .,i ~
'i. viscosity at processing temperatures should be no greater than 10 kP ~ -~;l; and preferably 5 kP (5 x 102N.s~m~), but not so low that settling out of r,', 20 solids could be a problem during casting and curing;
; ~ :
~ e) pot life should be at least 1 to 4 hours to permit time for ;`~ loading the batch into containers;
f) temperature during curing or mixing should not exceed breakdown ~ ;
temperature of any of the components;
i~ g) curing should be complete within a short period e.g. 48 hours, ~
". , :: , '. although this is not critical. It will be appreciated that excessively ~-long curing pPriods tie up curing ovens for too long a t~me, thus reducing `~
production rateæ or increasing capltal costs;
. . ~ .
h) mixtures should not shrink during the curing cycle and should have elastic properties such that they can withstand high impact and . still function nor~ally;
'".~ ` .'''-:' .~.:,., ~ .
. . :
'':~ ';
1~56i~
i) performancs characteristic~ and stablllty ~hould not vary adversely over a 5 year storage perIod or during extreme environmental ~reatment; and ~ ) performance must be equal to or better than conventional compositions.
~ s previou~ly indicated, commercially a~ailable dyes have, here !
tofore, only been available in the form of very find powders of the order of 10-15 microns. It ha~ now been determined that reduction in polymeric :: .
binder concentrations, improved smoke volumes and burn rate and improved mechanical and safety propertie~ can be achieved by u~ing larger dye particle~ of the order of 300-700 microns. Granulated dye particles having ~-~an average particle size of approximately 600 microns can be prepared by the procedure described in copending Canadian Application 247,694 filed March 11, 1976 in the names of Couture and Roy. Variously coloured dyes can be produced by the procedure described in the aforesald copending application but hereinafter reference will be made specifically to the use of l-amino-anthraquinone (l~Q~ which is particularly useful as the .;......................................................................... .
; colorant a~ it produces orange smoke when dispersed into the atmosphere.
., .
The oxidizer used in this invention may be any strong oxidizing agent known to those skilled in the pyrotechnic art. Such oxidizers include the chlorates, perchlorates and nitrates of alkali metals and/or ammonium. A particularly suitable oxid.tzing agent is potassium chlorate (KCL03) such as that supplied by Hooker Chemical Corporation in two grades: 10-12 microns, which i5 preferred and 160 microns average size.
; The fuel component may include any fuel known to those skilled - ;! ~
in the pyrotechnic art but in the practice of the present invention alpha-lactose in USP grade supplied by Anachemia Chemicals ha& been found particularly effective. The lactose is normally present in an amount between 7-10% by weight of the composition. In order to lower the decomposition temperature and to ad~ust the combustion rate, the lactose may b. replaced wholly or in part by sulphur. When used alone, sulphur ::. :
: i lOS6~8B
's present in an amolmt between S and 20~ and preferably 5 to 10% by weight of the composition.
As is well known in the pyrotechnic and propellant arts, a coolant or retardant is advantageously added to the fuel to control the decomposition temperature and for this purpo~e 1-5% by weight of sodium bicarbonate (NaHC03) USP grade from Anachemia Chemicals has bPen found suitable. It will, of course, be appreciated that the coolant is not an essential component and tha~ other coolants are known to those skilled in ~;
`; the art.
In order to speed up the combustion and augment the s~oke volume without ma~or lncreases in the combustion temperature, small quantities of a combustion catalyst may be incorporated into the smoke compositions of the present invention. Up to about 3% of a known combustion catalyst may be employed, although up to about 2% is preferred. Combustion catalysts include many metal oxides such as iron, nickel and cobalt oxides and a particularly suitable combustion catalyst has been found to be i~on oxlde (Fe203). When sulphur is used alone as a fuel, the burn rate is generally sufficiently high 60 that the combustlon catalyst may be eliminated from the mix.
, 20 A preferred binder in the smoke-producing and starter composi--- tions of the present invention i8 based on hydroxyl-terminated polybutadiene polymers such as those sold under the trade designations R-45M and R-45HT~
both manufactured by Arco Chemical Company, cured with a commercial diisocyanate (DDI) such as DDI-1410 marketed by General Mills or a tolyl dlisocyanate (TDI). The binder is preferably plasticized with from 20 to 30% by weight of an ester such as isodecyl perlargonate (IDP) in order to reduce the viscosity. A wetting agent, such as Asolecti~ ~ may also ~;
' be incorporated into the binder in order to reduce the viscosity of the :: ~
mix. As the wett~ng agent is not very soluble in the binder, it is prefer-ably first dissolved in benzene and then added as a solution to the mix.
Most of the solvent subsequently evaporates in the low pressure atmosphere _5_ . ' .
1~5~6~38 present duri~g mixing. Two alternative binder systems have also been successfully used. One i8 based upon polypropylene glycoL, such a8 Niax Diol ~ PPG-2025, cured with tolylene dii~ocyanate (TDI). An ad-vantage of this alternative polymeric binder i8 the lack of residue expansion after combustion, which may be a problem with the hydroxyl-terminated polybutadlene binder. However, the visco~ity of the poly-propylene glycol based binder ls ~omewhat hi~her and thi~ is not compen-sated by a shorter curing period. The other i9 an elastomeric binder based upon the hydroxyl telechelic polymer (PB/BO) disclosed in Canadian application 065,102l a ~riol crosslLnking agent, and a diisocyanate (TDI or DDI) as curing agent. A preferred trlol crosslinking agent is polyoxypropylene triol supplied under the trade name Pluracol TP4040 by ~ Wyandotte Chemical Corporation.
; In order to e~tabl~sh a safe and proper order for adding the ~ ingredients to the mixture during the mixing cycle, differentlal thermal , analysis and thermogravimetric analyses were conducted using a Mettler Thermoanaly~er. These tests showed that 50/50 mixtures of KC103/lactose and KC103lTDI produced explosions at 333C and 330C, respectively.
However, the former presented a strongly exothermic reaction at 196C
with a weight loss of 8%. For a mixture of KC103 and DDI, an exothermic reaction was observed between 340 and 400C, its maxi=um being at 386~C, but without an explosion. In the presence of the R-45N prepolymer, the .
melting point of KC103 shifted from 356 to 360C, indicating that this is a very stable mixture. Thus, in order to avoid the hazardous contact of !
i~ high concentrations of K~103 with lactose and KC103 with TDI or DDI, the KC103 should be fully dispersed in the homogeneous blend of binder, dye :. :.
; and lactose prior to the addition of DDI or TDI. Further, in those ca~es where higher viscosities are antlcipated, one-third of the dye may be incorporated at the end of the mi~ing cycle in order to keep the viscosity at a low value and to ensure good dispersion of KC103 and DDI. Thus, a general mixing and ca~ting procedure which will be described ln more detail ~.... 's -:'' .,~ , , ,', ` , .
l~Sti~
hereinafter in Example 1, using a high ~hear vertical Helicone 4 CV
mixer which can handle viscosities over 50 kP was developed. A
conventional horizontal mixer can also be used so long as the EOM
v:Lscosity is lower than 5 kP. Viscosities were determlned at 60C
using a HAT type Brookfield Vlscometer with a T-type spindle. During the mixing cycle and the curing perlod, temperatures in the mix did not exceed 65C. This was sufficiently below the exotherm observed at 196C by differential thermal analysls and thermogravimetric analysis. ~ ;
Because the main smoke-producing compo~ition i8 relatively difficult to ignite at 20C and i5 sub~ect to a slowinduc~ion period, a starter disc which is oxidi7er-rich, easier to ignite and which will burn .
faster, involving large amounts of heat and smoke, i8 highly desirable in order to achieve a faster and smoother build-up of heat. Starter compos-itions suitable for this purpose generally contain Z5-35% by weight oE a granular organic dye, 30-45% by weight of an oxidizing agent, 5-20~ by weight of a fuel and 18-25% by weight of the binder used in the main :
` composition. Particularly suitable compositions for the starter include the formulations set forth in Table I hereinbelow.
20 Starter Composition SK-109 SK-244 Ingredients% by Weight Dye 1- M Q (orange) 25 Dye Yellow Smoke VI - 30 ; KC103 40 38 Lactose 10 lO
Sodium Bicarbonate ~ 2 , Binder 25 20 : . - - .. __ __. . . . EOM Viscosity (kP) .7 1.17 The invention will be described in more detail hereinafter with reference to Examples I and II which in turn make reference to Flgures 1 and 2.
EXAMPLE I
A composition containing 48.73 parts by weight of l-AAQs 23.8 parts by weight KCl03, 7~93 parts by weight lactose, 2.27 parts by weight t `
~7~
.'~. .~ ' .
Fe203, 2.27 parts by weight NaHC03 and 15 parts by weight of a binder comprlsing R-45M, 55.85% by ~eight, IDP 30% by weight and DDI-1410, 14.15% by weight, was mixed according to the following procedure:
a) the prepolymer, plasticixer, and A~olectin were added and mlxed for 5 minutes, b) the lactose, sodium bicarbona~e and catalyst were added and mixed for 15 minute~, c) 2/3 of the l-AAQ was added and mixed for 25 minutes, ` d) the KC103 was added and mixed for 15 minutes, e~ the curing agent was added and mixed for 5 minutes, and f) the remaining 1/3 oi the l-AAQ was added and mixed for 30 minutes.
The composition thus produced had an end-of-mix (EOM) viscosity of 2.7 kP
at 60C. This compositlon was charged by gravity and under vacuum into resin impregnated Kraft paper tubes 7 inches long x 2.6 inches I.D. The tubes ~ere then placed in an oven at 60C for 6 days ln order to vulcanize the composition. The castings were then removed and assembled for firing in the apparatus shown in Figure 1.
In Figure 1 there is shown a test generator tube 1, 7 inches long ~ 20 x 2.6 inches I.D., containing a 4.5 inch cast column of the smoke producing `~ composition 2. An axially placed perforated vent tube 3, 3 inches long x 1 inch diameter is provided in the column of smoke producing composition.
; To complete the test unit, a 60 gram starter disc 4 is provided at the bottom of the column 2 together with a priming disc S. An electric squib . :
6 is provided to serve as the ignitor source. Thin metal covers 7 and 8 ;
close the ends of the tube, held in place by circlips or springs 10. An axial vent hole 9 is provided in metal cover 8.
.
Upon igni~ion in the test generator 1, the composition described hereinabove produced a satisfactory amount of good quality orange smoke for about 2 minutes.
: ~ .
.'`'' '" ~.
. -, .
. .
.
', ' , .;
~.~56~
EXA~LE II
A composition comprising 50.3 parts by weight l-AAQ, 21.5 partc `~`
by weight KC103, 5.1 parts by welght sulphur, 5.1 parts by weight Na~C03, ; and 18 parts by weight of binder was p~epared by the same mixing, pouring :
and vulcanizing procedures as set ~orthin E~ample I. The sulphur was `~ added at the same time as the NaHC03. The post mixing viscosity was 1.65 kP. A test generator as described with reference to Exa~ple I and in Figure 1, W8S prepared and ignited. This generator yielded smoke similar to that in Example I for 1.5 minutes.
EXAMPLE III ;~
A composition comprising 40 parts by weight dye (yellow smoke 6), 30 parts by weight KC103, 8 parts by weight lactose, 2 parts by weight .
NaHC03 and 20 parts by weight of the binder as employed in Example I, was prepared by the same mixing, casting and curing techniques as set forth in . ':
Examples I and II. The composition was cast into a smoke generator des-- cribed hereinafter with reference to Figure 2. In Figure 2 there is shown : `, ,:
a 10 ounce can 11 4 inches high x 2.6 i.D, having a base 12. An inert `
` base filler material 13 was placed in the can followed by a priming disc i; 14, a squib 15 and a starter disc20 (composition SK 2449 Table I) using ~ 20 the same colour as the main smoke composition described in this Example.
; ., - A 3 inch cast column 16 of the smoke composition, with a central cavity 17 was then inserted and the can was closed with a crimped lid 18 provided `~
with a vent hole 19. Upon ignition this generator had a fast build-up and produced a very hlgh volume of good quality yellow smoke (as per Munsell Colour Standard Number 5Y 8.5/12) for 70 seconds. ~;
:: .
It will, of course~ be appreciated that many modifications are possible without depar~ing from the scope of this invention. In particular, '~ although particular methods of formulating the compositions of this in-vention have been described it will be appreciated that other formulating means can be used and, further~ore, that virtually any suitable type of ~ `
container can be used. Other well known ignition systems such as the use - ~
:. ~ .::
:. :
~9- ~
:~ -1~5f~BB
of fuses with or without percusaion cap6 to facilitate the use of these compositions in such munition~ a~ grenades and mortar bombs can also be employed.
As previously noted, although reference has been made specifl-cally to the generation of orange ~moke for search and rescue purposes using l-AAQ, other dye compositions, such as 1,4-dimethylamino anthraquinone, Disperse Red 9, Dye Mlx Violet 9, Smoke Yellow 6 and Smoke Green 4 to produce blue, red, violet, yellow and green smoke, respectlvely, in addition to other dyes may be employed with equal effectiveness. Such dyes are well known to personi skllled in the art.
~' .
.~ . ' .
'~
,'; ;:
.': , :
:, .' ' ':
: ,' , !.
, -1~ ` ";
S6~8~
~~ compri~ing 25~35% by weight o~ a granular organic dye having an average ;~
particle size in the range 300-700 microns, 30-45% by weight of an oxid-izing agent, 5-20% by weight of a fuel and 18-25% by weight of a binder.
In the drawlng~ accompanying this specification, Figure 1 1~ a cross-sectional view of a amoke generator - incorporating the compositions accordlng to the pregent invention and : Figure 2 i~ a cros~-sectlonal view of an alternative tes~ ~moke generator incorporating the compositiong according to the present invention. ;~
Becsuse of safety, processing and cost considerations, additional restrictive properties whlch must be taken into account in the preparation of castable formulations include:
~ .,: - .
- a) polymer make-up chemicals must be available at low cost;
. . : .
b) compositions should be processable in low co~t equipment (i.e.
mix viscosities must be sufficiently low);
c) in8redients must be compatible during mixing, both from a chemical ~ ;
and an explosiveg sa~ety point of view;
d) to achieve pour-castable formulations, the end of-mix (EOM) .,i ~
'i. viscosity at processing temperatures should be no greater than 10 kP ~ -~;l; and preferably 5 kP (5 x 102N.s~m~), but not so low that settling out of r,', 20 solids could be a problem during casting and curing;
; ~ :
~ e) pot life should be at least 1 to 4 hours to permit time for ;`~ loading the batch into containers;
f) temperature during curing or mixing should not exceed breakdown ~ ;
temperature of any of the components;
i~ g) curing should be complete within a short period e.g. 48 hours, ~
". , :: , '. although this is not critical. It will be appreciated that excessively ~-long curing pPriods tie up curing ovens for too long a t~me, thus reducing `~
production rateæ or increasing capltal costs;
. . ~ .
h) mixtures should not shrink during the curing cycle and should have elastic properties such that they can withstand high impact and . still function nor~ally;
'".~ ` .'''-:' .~.:,., ~ .
. . :
'':~ ';
1~56i~
i) performancs characteristic~ and stablllty ~hould not vary adversely over a 5 year storage perIod or during extreme environmental ~reatment; and ~ ) performance must be equal to or better than conventional compositions.
~ s previou~ly indicated, commercially a~ailable dyes have, here !
tofore, only been available in the form of very find powders of the order of 10-15 microns. It ha~ now been determined that reduction in polymeric :: .
binder concentrations, improved smoke volumes and burn rate and improved mechanical and safety propertie~ can be achieved by u~ing larger dye particle~ of the order of 300-700 microns. Granulated dye particles having ~-~an average particle size of approximately 600 microns can be prepared by the procedure described in copending Canadian Application 247,694 filed March 11, 1976 in the names of Couture and Roy. Variously coloured dyes can be produced by the procedure described in the aforesald copending application but hereinafter reference will be made specifically to the use of l-amino-anthraquinone (l~Q~ which is particularly useful as the .;......................................................................... .
; colorant a~ it produces orange smoke when dispersed into the atmosphere.
., .
The oxidizer used in this invention may be any strong oxidizing agent known to those skilled in the pyrotechnic art. Such oxidizers include the chlorates, perchlorates and nitrates of alkali metals and/or ammonium. A particularly suitable oxid.tzing agent is potassium chlorate (KCL03) such as that supplied by Hooker Chemical Corporation in two grades: 10-12 microns, which i5 preferred and 160 microns average size.
; The fuel component may include any fuel known to those skilled - ;! ~
in the pyrotechnic art but in the practice of the present invention alpha-lactose in USP grade supplied by Anachemia Chemicals ha& been found particularly effective. The lactose is normally present in an amount between 7-10% by weight of the composition. In order to lower the decomposition temperature and to ad~ust the combustion rate, the lactose may b. replaced wholly or in part by sulphur. When used alone, sulphur ::. :
: i lOS6~8B
's present in an amolmt between S and 20~ and preferably 5 to 10% by weight of the composition.
As is well known in the pyrotechnic and propellant arts, a coolant or retardant is advantageously added to the fuel to control the decomposition temperature and for this purpo~e 1-5% by weight of sodium bicarbonate (NaHC03) USP grade from Anachemia Chemicals has bPen found suitable. It will, of course, be appreciated that the coolant is not an essential component and tha~ other coolants are known to those skilled in ~;
`; the art.
In order to speed up the combustion and augment the s~oke volume without ma~or lncreases in the combustion temperature, small quantities of a combustion catalyst may be incorporated into the smoke compositions of the present invention. Up to about 3% of a known combustion catalyst may be employed, although up to about 2% is preferred. Combustion catalysts include many metal oxides such as iron, nickel and cobalt oxides and a particularly suitable combustion catalyst has been found to be i~on oxlde (Fe203). When sulphur is used alone as a fuel, the burn rate is generally sufficiently high 60 that the combustlon catalyst may be eliminated from the mix.
, 20 A preferred binder in the smoke-producing and starter composi--- tions of the present invention i8 based on hydroxyl-terminated polybutadiene polymers such as those sold under the trade designations R-45M and R-45HT~
both manufactured by Arco Chemical Company, cured with a commercial diisocyanate (DDI) such as DDI-1410 marketed by General Mills or a tolyl dlisocyanate (TDI). The binder is preferably plasticized with from 20 to 30% by weight of an ester such as isodecyl perlargonate (IDP) in order to reduce the viscosity. A wetting agent, such as Asolecti~ ~ may also ~;
' be incorporated into the binder in order to reduce the viscosity of the :: ~
mix. As the wett~ng agent is not very soluble in the binder, it is prefer-ably first dissolved in benzene and then added as a solution to the mix.
Most of the solvent subsequently evaporates in the low pressure atmosphere _5_ . ' .
1~5~6~38 present duri~g mixing. Two alternative binder systems have also been successfully used. One i8 based upon polypropylene glycoL, such a8 Niax Diol ~ PPG-2025, cured with tolylene dii~ocyanate (TDI). An ad-vantage of this alternative polymeric binder i8 the lack of residue expansion after combustion, which may be a problem with the hydroxyl-terminated polybutadlene binder. However, the visco~ity of the poly-propylene glycol based binder ls ~omewhat hi~her and thi~ is not compen-sated by a shorter curing period. The other i9 an elastomeric binder based upon the hydroxyl telechelic polymer (PB/BO) disclosed in Canadian application 065,102l a ~riol crosslLnking agent, and a diisocyanate (TDI or DDI) as curing agent. A preferred trlol crosslinking agent is polyoxypropylene triol supplied under the trade name Pluracol TP4040 by ~ Wyandotte Chemical Corporation.
; In order to e~tabl~sh a safe and proper order for adding the ~ ingredients to the mixture during the mixing cycle, differentlal thermal , analysis and thermogravimetric analyses were conducted using a Mettler Thermoanaly~er. These tests showed that 50/50 mixtures of KC103/lactose and KC103lTDI produced explosions at 333C and 330C, respectively.
However, the former presented a strongly exothermic reaction at 196C
with a weight loss of 8%. For a mixture of KC103 and DDI, an exothermic reaction was observed between 340 and 400C, its maxi=um being at 386~C, but without an explosion. In the presence of the R-45N prepolymer, the .
melting point of KC103 shifted from 356 to 360C, indicating that this is a very stable mixture. Thus, in order to avoid the hazardous contact of !
i~ high concentrations of K~103 with lactose and KC103 with TDI or DDI, the KC103 should be fully dispersed in the homogeneous blend of binder, dye :. :.
; and lactose prior to the addition of DDI or TDI. Further, in those ca~es where higher viscosities are antlcipated, one-third of the dye may be incorporated at the end of the mi~ing cycle in order to keep the viscosity at a low value and to ensure good dispersion of KC103 and DDI. Thus, a general mixing and ca~ting procedure which will be described ln more detail ~.... 's -:'' .,~ , , ,', ` , .
l~Sti~
hereinafter in Example 1, using a high ~hear vertical Helicone 4 CV
mixer which can handle viscosities over 50 kP was developed. A
conventional horizontal mixer can also be used so long as the EOM
v:Lscosity is lower than 5 kP. Viscosities were determlned at 60C
using a HAT type Brookfield Vlscometer with a T-type spindle. During the mixing cycle and the curing perlod, temperatures in the mix did not exceed 65C. This was sufficiently below the exotherm observed at 196C by differential thermal analysls and thermogravimetric analysis. ~ ;
Because the main smoke-producing compo~ition i8 relatively difficult to ignite at 20C and i5 sub~ect to a slowinduc~ion period, a starter disc which is oxidi7er-rich, easier to ignite and which will burn .
faster, involving large amounts of heat and smoke, i8 highly desirable in order to achieve a faster and smoother build-up of heat. Starter compos-itions suitable for this purpose generally contain Z5-35% by weight oE a granular organic dye, 30-45% by weight of an oxidizing agent, 5-20~ by weight of a fuel and 18-25% by weight of the binder used in the main :
` composition. Particularly suitable compositions for the starter include the formulations set forth in Table I hereinbelow.
20 Starter Composition SK-109 SK-244 Ingredients% by Weight Dye 1- M Q (orange) 25 Dye Yellow Smoke VI - 30 ; KC103 40 38 Lactose 10 lO
Sodium Bicarbonate ~ 2 , Binder 25 20 : . - - .. __ __. . . . EOM Viscosity (kP) .7 1.17 The invention will be described in more detail hereinafter with reference to Examples I and II which in turn make reference to Flgures 1 and 2.
EXAMPLE I
A composition containing 48.73 parts by weight of l-AAQs 23.8 parts by weight KCl03, 7~93 parts by weight lactose, 2.27 parts by weight t `
~7~
.'~. .~ ' .
Fe203, 2.27 parts by weight NaHC03 and 15 parts by weight of a binder comprlsing R-45M, 55.85% by ~eight, IDP 30% by weight and DDI-1410, 14.15% by weight, was mixed according to the following procedure:
a) the prepolymer, plasticixer, and A~olectin were added and mlxed for 5 minutes, b) the lactose, sodium bicarbona~e and catalyst were added and mixed for 15 minute~, c) 2/3 of the l-AAQ was added and mixed for 25 minutes, ` d) the KC103 was added and mixed for 15 minutes, e~ the curing agent was added and mixed for 5 minutes, and f) the remaining 1/3 oi the l-AAQ was added and mixed for 30 minutes.
The composition thus produced had an end-of-mix (EOM) viscosity of 2.7 kP
at 60C. This compositlon was charged by gravity and under vacuum into resin impregnated Kraft paper tubes 7 inches long x 2.6 inches I.D. The tubes ~ere then placed in an oven at 60C for 6 days ln order to vulcanize the composition. The castings were then removed and assembled for firing in the apparatus shown in Figure 1.
In Figure 1 there is shown a test generator tube 1, 7 inches long ~ 20 x 2.6 inches I.D., containing a 4.5 inch cast column of the smoke producing `~ composition 2. An axially placed perforated vent tube 3, 3 inches long x 1 inch diameter is provided in the column of smoke producing composition.
; To complete the test unit, a 60 gram starter disc 4 is provided at the bottom of the column 2 together with a priming disc S. An electric squib . :
6 is provided to serve as the ignitor source. Thin metal covers 7 and 8 ;
close the ends of the tube, held in place by circlips or springs 10. An axial vent hole 9 is provided in metal cover 8.
.
Upon igni~ion in the test generator 1, the composition described hereinabove produced a satisfactory amount of good quality orange smoke for about 2 minutes.
: ~ .
.'`'' '" ~.
. -, .
. .
.
', ' , .;
~.~56~
EXA~LE II
A composition comprising 50.3 parts by weight l-AAQ, 21.5 partc `~`
by weight KC103, 5.1 parts by welght sulphur, 5.1 parts by weight Na~C03, ; and 18 parts by weight of binder was p~epared by the same mixing, pouring :
and vulcanizing procedures as set ~orthin E~ample I. The sulphur was `~ added at the same time as the NaHC03. The post mixing viscosity was 1.65 kP. A test generator as described with reference to Exa~ple I and in Figure 1, W8S prepared and ignited. This generator yielded smoke similar to that in Example I for 1.5 minutes.
EXAMPLE III ;~
A composition comprising 40 parts by weight dye (yellow smoke 6), 30 parts by weight KC103, 8 parts by weight lactose, 2 parts by weight .
NaHC03 and 20 parts by weight of the binder as employed in Example I, was prepared by the same mixing, casting and curing techniques as set forth in . ':
Examples I and II. The composition was cast into a smoke generator des-- cribed hereinafter with reference to Figure 2. In Figure 2 there is shown : `, ,:
a 10 ounce can 11 4 inches high x 2.6 i.D, having a base 12. An inert `
` base filler material 13 was placed in the can followed by a priming disc i; 14, a squib 15 and a starter disc20 (composition SK 2449 Table I) using ~ 20 the same colour as the main smoke composition described in this Example.
; ., - A 3 inch cast column 16 of the smoke composition, with a central cavity 17 was then inserted and the can was closed with a crimped lid 18 provided `~
with a vent hole 19. Upon ignition this generator had a fast build-up and produced a very hlgh volume of good quality yellow smoke (as per Munsell Colour Standard Number 5Y 8.5/12) for 70 seconds. ~;
:: .
It will, of course~ be appreciated that many modifications are possible without depar~ing from the scope of this invention. In particular, '~ although particular methods of formulating the compositions of this in-vention have been described it will be appreciated that other formulating means can be used and, further~ore, that virtually any suitable type of ~ `
container can be used. Other well known ignition systems such as the use - ~
:. ~ .::
:. :
~9- ~
:~ -1~5f~BB
of fuses with or without percusaion cap6 to facilitate the use of these compositions in such munition~ a~ grenades and mortar bombs can also be employed.
As previously noted, although reference has been made specifl-cally to the generation of orange ~moke for search and rescue purposes using l-AAQ, other dye compositions, such as 1,4-dimethylamino anthraquinone, Disperse Red 9, Dye Mlx Violet 9, Smoke Yellow 6 and Smoke Green 4 to produce blue, red, violet, yellow and green smoke, respectlvely, in addition to other dyes may be employed with equal effectiveness. Such dyes are well known to personi skllled in the art.
~' .
.~ . ' .
'~
,'; ;:
.': , :
:, .' ' ':
: ,' , !.
, -1~ ` ";
Claims (15)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A pour-castable smoke-producing composition containing 30-50%
by weight of a granular organic dye having a particle size in the range 300 to 700 microns, 20-35% by weight of an oxidizing agent, 5-20% by weight of a fuel and 14-22% by weight of a binder.
by weight of a granular organic dye having a particle size in the range 300 to 700 microns, 20-35% by weight of an oxidizing agent, 5-20% by weight of a fuel and 14-22% by weight of a binder.
2. A pour-castable smoke-producing composition as claimed in claim 1 additionally including 1-5% by weight of a cooling agent.
3. A pour-castable smoke-producing composition as claimed in claim 1 additionally including up to 3% by weight of a combustion catalyst.
4. A pour-castable smoke-producing composition as claimed in claim 1, 2 or 3 wherein said organic dye is selected from the group comprising 1-amino-anthraquinone, 1-4-dimethylamino anthraquinone, disperse red 9, dye mix violet 9, smoke yellow 6 and smoke green 4.
5. A pour-castable smoke-producing composition as claimed in claim 1, 2 or 3 wherein said oxidizing agent is selected from chlorates, nitrates and perchlorates of alkali metals and ammonium.
6. A pour-castable smoke-producing composition as claimed in claim 1, 2 or 3 wherein said fuel is selected from the group comprising lactose, sulphur and mixtures thereof.
7. A pour-castable smoke-producing composition as claimed in claim 1 wherein said binder is hydroxyl-terminated polybutadiene cured with a diisocyanate selected from dimeryl diisocyanate and tolyl diisocyanate.
8. A pour-castable smoke-producing composition as claimed in claim 7 wherein said binder additionally includes 20-30% by weight of isodecyl perlargonate.
9. A pour-castable smoke-producing composition as claimed in claim 2 wherein said cooling agent is sodium bicarbonate.
10. A pour-castable smoke-producing composition as claimed in claim 3 wherein said combustion catalyst is selected from the group comprising iron, nickel and cobalt oxides.
11. A pour-castable smoke-producing composition as claimed in claim 1, 2 or 3 wherein said fuel comprises 5-20% by weight lactose.
12. A smoke generator comprising a casing, a smoke-producing composi tion as claimed in claim 1, a starter composition for igniting said smoke-producing composition, and means for firing said starter.
13. A smoke generator as claimed in claim 12 wherein said starter composition comprises 25-35% by weight of a granular organic dye having an average particle size in the range 300-700 microns, 30-45% by weight of an oxidizing agent, 5-20% by weight of a fuel and 18-25% by weight of a binder.
14. A smoke generator as claimed in claim 12 or 13 wherein said means for firing said starter includes a sensitized igniter disc and electric squib means.
15. A pour-castable starter composition for igniting a smoke-produc-ing composition, comprising 25-35% by weight of a granular organic dye having an average particle size in the range 300-700 microns, 30-45% by weight of an oxidizing agent, 5-20% by weight of a fuel and 18-25% by weight of a binder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA259,735A CA1056688A (en) | 1976-08-24 | 1976-08-24 | Pour-castable smoke compositions |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA259,735A CA1056688A (en) | 1976-08-24 | 1976-08-24 | Pour-castable smoke compositions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1056688A true CA1056688A (en) | 1979-06-19 |
Family
ID=4106717
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA259,735A Expired CA1056688A (en) | 1976-08-24 | 1976-08-24 | Pour-castable smoke compositions |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1056688A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2574535A1 (en) * | 1984-12-07 | 1986-06-13 | Poudres & Explosifs Ste Nale | Pyrotechnic tracer having an improved ignition device |
| WO2002001530A2 (en) * | 2000-06-28 | 2002-01-03 | Ici Americas Inc. | Flexible smoke generator |
-
1976
- 1976-08-24 CA CA259,735A patent/CA1056688A/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2574535A1 (en) * | 1984-12-07 | 1986-06-13 | Poudres & Explosifs Ste Nale | Pyrotechnic tracer having an improved ignition device |
| WO2002001530A2 (en) * | 2000-06-28 | 2002-01-03 | Ici Americas Inc. | Flexible smoke generator |
| WO2002001530A3 (en) * | 2000-06-28 | 2002-06-06 | Ici America Inc | Flexible smoke generator |
| US6552660B1 (en) | 2000-06-28 | 2003-04-22 | 3Si Security Systems, Inc. | Flexible smoke generator |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3779823A (en) | Abrasion resistant gas generating compositions for use in inflating safety crash bags | |
| EP0482755B1 (en) | Ignition composition for inflator gas generators | |
| US3650856A (en) | Red phosphorus castable smoke producing composition | |
| EP0553476B1 (en) | Chlorine-free composite rocket propellant | |
| DE4026465C2 (en) | Solid fuels with a binder of non-crystalline polyester / inert plasticizer | |
| US3830672A (en) | Solid porous, coated oxidizer, method of preparation and novel propellant compositions | |
| US3350245A (en) | Composite polyether propellants | |
| EP0520104A1 (en) | Non-self-deflagrating fuel compositions for high regression rate hybrid rocket motor application | |
| US3467558A (en) | Pyrotechnic disseminating composition containing an agent to be disseminated | |
| US3144829A (en) | Solid propellant charge | |
| US3695952A (en) | Solid propellant compositions containing hydroxymethyl-terminated polydienes | |
| CA1056688A (en) | Pour-castable smoke compositions | |
| US4997497A (en) | Castable smoke-producing pyrotechnic compositions | |
| US4366010A (en) | Smoke-producing pyrotechnic composition and its application | |
| US5509981A (en) | Hybrid rocket fuel | |
| US4923535A (en) | Polymer binding of particulate materials | |
| US4057441A (en) | Solid propellant with burning rate catalyst | |
| US3214308A (en) | Thermally stable propellant powders containing powdered polymeric materials and perchlorates | |
| US3692597A (en) | Polyurethane propellant compositions and their preparation | |
| US3668026A (en) | Castable pyrotechnic colored smoke composition | |
| US2995430A (en) | Composite propellant reinforced with | |
| US3755019A (en) | Solid propellant compositions containing plasticized nitrocellulose and aluminum hydride | |
| US3215028A (en) | Means and method for restricting a solid propellant | |
| US5753853A (en) | Solid propellant with titanate bonding agent | |
| US20060042731A1 (en) | Low humidity uptake solid pyrotechnic compositions and methods for making the same |