KR20170007244A - Low-toxicity smoke pyrotechnic compositions for wide-band masking - Google Patents

Abstract

FIELD OF THE INVENTION [0002] The present invention relates to a smoke chemical composition for the purpose of protecting a land platform, particularly in the case of an infrared inducing threat. The composition comprises a polyaromatic or polyheteroaromatic compound substituted with 1 to 3 bromine atoms as a fuel in a chemical composition, preferably a smoke-polymerizing composition, and when the composition burns, a toxic substance of a release gas such as hydrobromic acid The content is less than 350 ppm, preferably less than 300 ppm.

Description

TECHNICAL FIELD [0001] The present invention relates to a low toxicity smoke chemical composition for broadband concealment,

The present invention relates to a low toxic pyrotechnic composition and is intended to protect a land platform (e.g., a vehicle or an armored vehicle), particularly against infrared-induced threats. The composition can produce an effective camouflage cloud in the infrared and visible light regions.

Recently used concealment compositions generally include compositions that serve as redox pair and fuel. At the time of combustion, the fuel enables the production of particles of suitable size and shape to ensure effective concealment in visible and infrared, in particular in the spectral window between 3 and 14 [mu] m. These compositions include CLONACIRE (a composition comprising a mixture of chlorinated naphthalene with a level of substitution of more than 3) or a chlorinated compound such as hexachloroethane. They play a role either as an oxidizing agent or as a particle product.

However, these largely chlorinated compounds form large amounts of toxic substances, especially HCl (gaseous hydrogen chloride), upon degradation.

According to the evaluation of the "Ministry of Ecology and Sustainable Development and the Ministry of Health, INERIS sheet, 2003", the threshold and irreversible effects on the first lethal effect associated with gas HCl exposure for 10 minutes The threshold value is 1300ppm (1937mg / m3, threshold of first lethal effect) and 240ppm (358mg / m3, threshold of irreversible effect).

Accordingly, there is a demand for a chemical composition exhibiting good hiding performance with low toxicity.

The use of bromine compounds in chemical compositions, especially as decoys for the protection of public targets against the threat of infrared radiation, is already known, but does not address the toxicity of these compounds. The effect required in this case is generally not a concealment smoke, but rather an infrared that imitates the radiation of the motor of the aerial platform.

US 5,389,308, which relates to compositions that produce opaque opaque smoke, including magnesium powder, fluorinated organic polymers, chloroparaffins, and aromatic compounds, which may be brominated aromatic compounds such as 8-bromoanthracene, Compounds are preferable because they are low in toxicity.

Similarly, US 3,498,925 and US 3,400,082 disclose the use of metals or organometallic compounds in addition to non-halogen compounds to reduce the toxicity of chemical compositions for hiding in visible light. Application US 2012/0267016 on smoke generating compositions for the hiding in visible light recommends the use of a mixture comprising melamine and polymethylmethylated gallate. These compositions also include sucrose as a fuel and chlorate as an oxidizing agent. In addition, US 4,238,254 discloses a chemical composition for the hiding of visible light, comprising guanidine nitrate, which produces a basic compound capable of neutralizing hydrogen chloride (HCl) or phosphorus pentoxide produced in smoke.

Thus, the prior art consistently teaches that any use of halides as oxidizing agents, reducing agents or fuels should be avoided, in order to consistently reduce or eliminate the toxicity of these hiding chemical compositions.

Surprisingly, the present application nonetheless exploits the use of a polyaromatic or polyheteroaromatic compound substituted with one to three bromine atoms in a chemical composition, preferably a smoke-generating chemical composition, as fuel, while maintaining the hiding performance in both visible and infrared It is mentioned that the toxicity of the chemical composition can be remarkably reduced compared with the prior art.

The "spectral window" according to the invention specifies the range of wavelengths. A "polyaromatic" compound according to the invention denotes a C ₁₀ to C ₁₄ hydrocarbon compound consisting of two to three condensed aromatic rings. In particular, naphthalene, anthracene and phenanthrene may be mentioned as examples of polyaromatic compounds. The polyaromatic compound is preferably naphthalene or anthracene, more preferably naphthalene.

A "polyheteroaromatic" compound according to the present invention refers to a compound comprising two to three condensed aromatic rings or heteroaromatic rings and containing at least one nitrogen heteroaromatic ring. In particular, quinoline, isoquinoline and naphthyridine may be mentioned as examples of polyheteroaromatic compounds. The polyheteroaromatic compound is preferably quinoline.

A "chlorinated compound" according to the present invention specifies an organic compound comprising at least one chlorine atom, especially a compound comprising at least one carbon-chlorine (C-Cl) bond.

The present invention relates to chemically stable compounds.

Preferably, the polyaromatic or polyheteroaromatic compounds substituted with one to three bromine atoms according to the present invention do not contain a chlorine substituent.

Preferably, the polyaromatic or polyheteroaromatic compound substituted with one to three bromine atoms does not include any other substituents.

To determine the toxicity of the chemical composition, the potential toxic species released during combustion of the smoke generating composition is determined. The amount of emissions during combustion is evaluated by thermodynamic calculations. For each identified toxic species, the threshold of the first lethal and irreversible effects is taken from the literature. These two thresholds are evaluated as a function of the exposure time of the subject to the toxic substance, here the gaseous HBr.

According to the report of "Toxicology Expert Group of the Ministry of Ecology, Energy, Sustainable Development and Developments of the Territory" (Apr. 15, 2008), the threshold of the first lethal effect on exposure of gas HBr for 10 minutes and the irreversible The threshold of effect is 3290ppm (11054mg / m3, threshold of first lethal effect) and 366ppm (1228mg / m3, threshold of irreversible effect).

Accordingly, the present invention relates to the use of a polyaromatic or polyheteroaromatic compound substituted with one to three bromine atoms as a fuel in a chemical composition, preferably a smoke-generating chemical composition, so that upon combustion of the composition, The concentration of toxic substances such as hydrogen bromide in the gas is less than 350 ppm, preferably less than 300 ppm.

The present invention also relates to a process for the preparation of a chemical composition, preferably a process for the production of a smoke, preferably a process for the production of smoke, comprising the step of reacting at least one polyaromatic or polyheteroaromatic compound substituted with one to three bromine atoms as a reducing agent, ≪ RTI ID = 0.0 >

With respect to the total weight of the composition,

- 5 to 25% by weight of a reducing agent,

2 to 25% by weight of a binder optionally mixed with a plasticizer, and

50 to 90% by weight of a fuel comprising at least one polyaromatic or polyheteroaromatic compound substituted with 1 to 3 bromine atoms,

- optionally 5 to 15% by weight of an oxidizing agent,

- optionally 2 to 10% by weight of the additive.

The present invention also relates to a chemical mechanical device comprising said composition. The present invention also relates to a process for the transfer of infrared radiation between a target and a threat using a chemical composition, preferably a smoke-generating chemical composition, comprising as a fuel a polyaromatic or polyheteroaromatic compound substituted with one to three bromine atoms Lt; RTI ID = 0.0 > a < / RTI > target.

Accordingly, the present invention relates to the use of a polyaromatic or polyheteroaromatic compound substituted with one to three bromine atoms as defined above as a fuel in a chemical composition, preferably a smoke-generating chemical composition, wherein upon combustion of said composition, The concentration of toxic substances, in particular hydrogen bromide, in the gas is less than 350 ppm, preferably less than 300 ppm.

Preferably, the combustion of the composition provides a camouflage coefficient of greater than 50%, preferably greater than 60%, for 15 seconds, preferably 20 seconds, in a spectral window of 8-12 μm do.

Preferably, the combustion of the composition provides a camouflage coefficient of greater than 60%, preferably greater than 70%, for 15 seconds, preferably 20 seconds, in the spectral window of 3-5 [mu] m.

The "camouflage coefficient" according to the invention is expressed as a percentage and specifies the ratio Cm (t) calculated at time t according to the following equation:

Wherein,

Nb (t) and Nb ' are a numerical level having an effect on a hot source and a numeric level not having an effect on a hot source, respectively;

Nn (t) and Nn ' are the numerical level and the numerical level, respectively, having an effect on the cold source.

The stomach factor is generally controlled and measured under reproducible conditions. The measuring instruments used are:

A black-body type heat source representing a temperature adjusted to about 200 ° C;

- cold source (generally steel at ambient temperature)

And the like.

And, the receptor measuring means comprises:

A thermal camera operating in band 2 (3-5 [mu] m spectral window);

- Thermal camera operating in band 3 (8-12 μm spectral window)

.

Preferably, the smoke generating composition does not contain a chlorinated compound. Preferably, the polyaromatic or polyheteroaromatic compound is substituted with two bromine atoms; More preferably dibromonaphthalene or dibromoquinoline; More preferably, it is 1,4-dibromonaphthalene, 1,8-dibromoquinoline or 4,7-dibromoquinoline.

The present invention also relates to a process for the preparation of a chemical composition, preferably a process for the production of a smoke, preferably a process for the production of smoke, comprising the step of reacting at least one polyaromatic or polyheteroaromatic compound substituted with one to three bromine atoms as a reducing agent, ≪ RTI ID = 0.0 >

With respect to the total weight of the composition,

- 5 to 25% by weight, preferably 10 to 20% by weight,

2 to 25% by weight of a binder optionally mixed with a plasticizer, and

50 to 90% by weight, preferably 60 to 80% by weight, of a fuel comprising at least one polyaromatic or polyheteroaromatic compound substituted with 1 to 3 bromine atoms,

- optionally 5 to 15% by weight of an oxidizing agent,

- optionally 2 to 10% by weight of the additive.

If necessary, the weight of the binder is adjusted to make the percentage of various additive elements 100%. In this method, the percentage of binder is adjusted to the mass percentage of reducing agent, fuel, and optionally oxidizing agent and additive to obtain 100%.

Preferably, the composition does not contain a chlorinated compound.

Preferably, the polyaromatic or polyheteroaromatic compound is substituted with two bromine atoms. Preferably, the polyaromatic or polyheteroaromatic compound is substituted with two bromine atoms; More preferably dibromonaphthalene or dibromoquinoline; More preferably, it is 1,4-dibromonaphthalene, 1,8-dibromoquinoline or 4,7-dibromoquinoline.

In general, the reducing agent is selected from magnesium, aluminum, zirconium, titanium, silicon or boron, or mixtures thereof, for example as metal powders. Preferably, the reducing agent consists essentially of a magnesium powder or a powder of a mixture of zirconium and magnesium.

In the first embodiment, the binder also serves as an oxidizing agent. In this embodiment, the composition does not include an oxidizing agent and also a binder.

In the first embodiment, the chemical composition, preferably the smoke-generating chemical composition according to the present invention preferably comprises:

With respect to the total weight of the composition,

- 5 to 25% by weight of a reducing agent,

From 5 to 25% by weight, preferably from 10 to 15% by weight, of a binder optionally mixed with a plasticizer, and

50 to 90% by weight, preferably 60 to 70% by weight, of a fuel comprising at least one polyaromatic or polyheteroaromatic compound substituted with 1 to 3 bromine atoms,

Optionally 2 to 10% by weight of additive,

.

The binder may then be a fluoroelastomer or a mixture thereof, preferably polytetrafluoroethylene, poly (carbon monofluoride) (PMF) or vinylidene fluoride, hexafluoropropylene, perfluoromethyl vinyl ether and / or A copolymer of tetrafluoroethylene (e.g., VITON (R)) or a mixture thereof.

In the second embodiment, the binder does not serve as an oxidizing agent. In this embodiment, the composition according to the invention comprises from 5 to 15% by weight of an oxidizing agent and is preferably selected from potassium chlorate, ammonium chlorate, potassium perchlorate, ammonium perchlorate, potassium nitrate or ammonium nitrate, or mixtures thereof. The oxidizing agent may also be a fluoroelastomer or a mixture thereof, preferably polytetrafluoroethylene, poly (carbon monofluoride) (PMF) or vinylidene fluoride, hexafluoropropylene, perfluoromethyl vinyl ether and / or tetra A copolymer of fluoroethylene or a mixture thereof.

The binder is selected from a phenolic polymer, an epoxy resin or polybutadiene. In particular, when the binder is an epoxy resin, the oxidizing agent is advantageously a fluoroelastomer or a mixture thereof, advantageously polytetrafluoroethylene, poly (carbon monofluoride) (PMF) or vinylidene fluoride, hexafluoropropylene , Perfluoromethyl vinyl ether and / or tetrafluoroethylene, or mixtures thereof.

In the second embodiment, the chemical composition, preferably the smoke-generating chemical composition according to the present invention is preferably:

With respect to the total weight of the composition,

5 to 25% by weight, preferably 10 to 20% by weight of a reducing agent;

2 to 10% by weight, preferably 3 to 5% by weight, of a binder optionally mixed with a plasticizer;

5 to 15% by weight, preferably 10 to 15% by weight of an oxidizing agent; And

50 to 90% by weight, preferably 60 to 80% by weight, of a fuel comprising at least one polyaromatic or polyheteroaromatic compound substituted with 1 to 3 bromine atoms;

Optionally 2 to 10% by weight of additive,

.

The compositions according to the invention may also comprise additives, for example hardeners, combustion retardants or flame retardants. The combustion retardant is especially chosen from diatomaceous earth or graphite. An example of a preferred flame retardant is sodium bicarbonate. Preferred additives are combustion retardants and flame retardants.

The invention also relates to a chemical device comprising a vessel lodged in a useful charge of the chemical composition according to the invention. Preferably, the chemical composition according to the present invention is shaped by compression. A container is typically a smoke bomb or a grenade that can be fired from a launcher or thrown by hand.

The present invention also relates to a process for preparing a chemical composition, preferably a smoke film, which prevents the transfer of infrared rays between the target and the threat using a smoke-producing chemical composition, comprising a polyaromatic or polyheteroaromatic compound substituted with 1 to 3 bromine atoms as a fuel To a target concealment method.

Preferably, the chemical composition is as defined above.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a curve showing development of a gastrointestinal factor for a 3 to 5 탆 optical window for composition 1; the x-axis represents the time in seconds; The y-axis represents the stomach factor in%.
Fig. 2 is a curve showing the evolution of the stomach factor for the 8 to 12 탆 optical window for composition 1. Fig. the x-axis represents the time in seconds; The y-axis represents the stomach factor in%.
Figure 3 is a curve showing development of the gastrointestinal factor for a 3 to 5 탆 optical window for composition 2; the x-axis represents the time in seconds; The y-axis represents the stomach factor in%.
4 is a curve showing development of the camouflage coefficient for an 8 to 12 micron optical window for composition 2. Fig. the x-axis represents the time in seconds; The y-axis represents the stomach factor in%.

The following examples are provided to illustrate the present invention, but should not be construed as limiting its scope in any way.

Example  1: Toxicity assessment

The formation enthalpy of 1,4-dibromonaphthalene is defined as equivalent to 27.6 kcal / mol using Hyperchem software and literature data.

Experiments on the combustion of 1,4-dibromonaphthalene, which can identify species released during combustion, were performed with Coppelia software. At a pressure of 2 atm and a temperature of 2000 K, thermodynamic calculations were performed in the absence of oxygen in the atmosphere. According to this calculation, the mass fraction of the released species is mainly one toxic species, HBr. The mass fraction is provided as 0.3436 by Coppelia calculation.

From this result, it can be inferred that the source of smoke, that is, the maximum concentration of HBr near to the burning smoke char is 300 ppm. This concentration is rapidly degraded by dilution when moving away from this source.

On HBr  Toxicity threshold described in Korean literature:

Available data on gaseous HBr (the report of "Toxicology Expert Group of the Ministry of Ecology, Energy, Sustainable Development and Development of the Territory, April 15, 2008") shows the threshold of the first lethal effect Describe the threshold of the irreversible effect.

Example  2: Evaluation of concealment performance

Description of experimental composition :

The experimental composition comprises 1,4-dibromonaphthalene as a fuel. This precise fuel on the redox pair can ensure broadband concealment performance.

In the case of composition 1, the binder used is a Viton 占 type fluorinated polymer. The binder also serves as an oxidizing agent in the composition. The reducing agent used is magnesium. 1,4-dibromonaphthalene comprises about 70% by weight of the composition; The Viton (R) binder represents 11% by weight of the composition; The reducing agent is 19 mass% of the mixture.

In the case of Composition 2, the binder used is an epoxy resin combined with the curing agent. The oxidizing agent used in the composition is a polytetrafluoroethylene-type fluorinated polymer. The reducing agent used is magnesium. A combustion retardant, graphite, is also used in the composition. The 1,4-dibromonaphthalene constitutes 68% by mass of the composition. The composition contains 3% by mass of the binder, 17% by mass of the reducing agent, 10% by mass of the oxidizing agent, and 2% by mass of the combustion retarding agent.

The experimental composition is compressed in the form of a cylindrical smoke generating port. The mass of the composition contained in each port is about 400 g.

Explanation of experiment method:

The test method allows the smoke cloud to move at a controlled speed and pass in front of the measuring means described below in a controlled and reproducible manner.

Explanation of measuring means:

The measuring means comprises:

A black body type heat source showing a temperature adjusted to about 200 DEG C;

- cold source (generally steel at ambient temperature)

.

And, the receptor measuring device is:

A thermal camera operating in band 2 (3-5 [mu] m spectral window);

- Thermal camera operating in band 3 (8-12 μm spectral window)

Is located across the source.

Explanation of the use of smoke port:

Under controlled and reproducible conditions, the smoke cloud moves and passes in front of the measuring instrument, where the infrared performance of the smoke generating port can be measured.

Explanation of data processing method:

For each experimental port, the following values are calculated from the luminance measurements obtained by the band 2 and band 3 cameras.

Cm = camouflage coefficient calculated according to the following formula (expressed as a percentage):

Wherein,

Nb (t) and Nb ' are a numerical level having an effect on the heat source and a numerical level not having, respectively;

Nn (t) and Nn ' are the numerical level and the numerical level, respectively, having an effect on the cold source.

The results obtained for Compositions 1 and 2 of 3 to 5 占 퐉 and 8 to 12 占 퐉 spectral windows are shown in Figs.

For both Composition 1 and Composition 2, it can be seen that the combustion of the composition provides a camouflage factor of more than 50% for at least 20 seconds in the 3 to 5 占 퐉 and 8 to 12 占 퐉 spectral window.

More specifically, Composition 1 provides a stomach factor of greater than 70% for at least 15 seconds in a 3-5 [mu] m spectral window and a 60% stomach factor for at least 15 seconds in a 8 to 12 [mu] m spectral window.

Composition 2 ensures a stomach factor of over 70% for at least 30 seconds in a 3-5 [mu] m spectral window and a 60% stomach factor for at least 20 seconds in a 8-12 [mu] m spectral window.

Claims (16)

The use of polyaromatic or polyheteroaromatic compounds substituted with one to three bromine atoms, such as a fuel in a pyrotechnic composition, preferably a smoke-generating chemical composition,
At the time of combustion of the composition, the concentration of toxic substances, in particular hydrogen bromide, in the released gas is less than 400 ppm, preferably less than 350 ppm. The method according to claim 1,
Characterized in that the combustion of the composition provides a camouflage coefficient of more than 50%, preferably more than 60%, in a spectral window of 8 to 12 탆, generally for 15 seconds. The method according to claim 1 or 2,
Characterized in that the combustion of the composition provides a gastric coefficient of more than 60%, preferably more than 70%, in a 3 to 5 탆 spectral window, generally for 15 seconds. The method according to any one of claims 1 to 3,
Characterized in that the smoke-generating composition does not contain a chlorinated compound. The method according to any one of claims 1 to 4,
Wherein the polyaromatic or polyheteroaromatic compound is substituted with two bromine atoms. The method according to any one of claims 1 to 5,
Wherein the polyaromatic or polyheteroaromatic compound is dibromonaphthalene or dibromoquinoline. At least one polyaromatic or polyheteroaromatic compound substituted with from 1 to 3 bromine atoms as at least a reducing agent, a binder and a fuel, and optionally an oxidizing agent in the following proportions:
With respect to the total weight of the composition,
- 5 to 25% by weight of a reducing agent,
2 to 25% by weight of a binder optionally mixed with a plasticizer, and
50 to 90% by weight of a fuel comprising at least one polyaromatic or polyheteroaromatic compound substituted with 1 to 3 bromine atoms,
Optionally 5 to 15% by weight of an oxidizing agent, and
- optionally 2 to 10% by weight of the additive. The method of claim 7,
Wherein the composition does not contain a chlorinated compound. The method according to claim 7 or 8,
Wherein the polyaromatic or polyheteroaromatic compound is substituted with two bromine atoms. The method according to any one of claims 7 to 9,
Wherein the polyaromatic or polyheteroaromatic compound is dibromonaphthalene or dibromoquinoline. The method according to any one of claims 7 to 10,
The reducing agent is selected from magnesium, aluminum, zirconium, titanium, silicon or boron, or a mixture thereof, for example as a metal powder, and preferably the reducing agent is composed essentially of a powder of magnesium powder or a mixture of zirconium and magnesium ≪ / RTI > The method according to any one of claims 7 to 11,
Wherein the oxidizing agent is selected from potassium chlorate, ammonium chlorate, potassium perchlorate, ammonium perchlorate, potassium nitrate or ammonium nitrate, fluoroelastomers or mixtures thereof. The method of claim 12,
Wherein the binder is selected from a phenolic polymer, an epoxy resin or polybutadiene. The method according to any one of claims 7 to 11,
The binder also serves as an oxidizing agent and advantageously comprises a fluoroelastomer, advantageously polytetrafluoroethylene, poly (carbon monofluoride) or vinylidene fluoride, hexafluoropropylene, perfluoromethyl vinyl ether and / RTI > and / or copolymers of tetrafluoroethylene, or mixtures thereof. A chemical device comprising a container,
A smoke bomb or a grenade, generally fired from a launcher or capable of being thrown by hand, wherein the useful charge of the chemical composition according to any one of claims 7 to 14 is lodged, . A pyrolytic composition comprising a polyaromatic or polyheteroaromatic compound substituted with one to three bromine atoms as a fuel, preferably a smoke-generating composition using a smoke-generating chemical composition, A method of target concealment comprising:
The chemical composition is preferably as defined in any one of claims 7 to 14.

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