Efficient smoke composition in visible and infrared ranges

Abstract

A smoke composition which is effective in the visible and infrared ranges and includes at least one oxidant and at least one reducing agent and at least one smoke agent generating carbon particles. This composition has superchlorinated polyvinyl chloride (C-PVC) as smoke agent, wherein the chlorine content of this smoke agent is between 57% and 70% of the weight of superchlorinated polyvinyl chloride, wherein the composition has 49% to 90% by weight of superchlorinated polyvinyl chloride (C-PVC) based on the total weight of the composition.

Claims

1. A smoke composition comprising at least one oxidant, at least one reducing agent, and at least one smoke agent generating carbon particles comprising, superchlorinated polyvinyl chloride, wherein a chlorine content of the superchlorinated polyvinyl chloride is between 57% and 70% of the weight of the superchlorinated polyvinyl chloride, wherein the composition comprises 49% to 90% by weight of the superchlorinated polyvinyl chloride relative to the total weight of the composition, and wherein upon combustion, the smoke composition provides masking in the visible and infrared ranges.

2. The smoke composition according to claim 1, wherein the smoke composition comprises 5% to 30% by weight of reducing agent, 5% to 29% by weight of oxidant, 0% to 30% of binder and 0% to 5% of additives.

3. The smoke composition according to claim 2, wherein the reducing agent is selected from the group consisting of the following bodies or compounds: magnesium, aluminum, calcium silicide and mixtures thereof.

4. The smoke composition according to claim 3, wherein the oxidant is selected from the group consisting of the following compounds: potassium perchlorate (KClO.sub.4), potassium nitrate (KNO.sub.3), potassium permanganate (KMnO.sub.4), potassium periodate (KIO.sub.4), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE).

5. The smoke composition according to claim 2, wherein the binder is present and is selected from the group consisting of thermoplastic resins, polyurethane resin, epoxy resins, hydroxytelechelic polybutadiene (PBHT), dinitroanisole, and mixtures thereof.

6. The smoke composition according to claim 3, wherein the binder is present and is selected from the group consisting of thermoplastic resins, polyurethane resin, epoxy resins, hydroxytelechelic polybutadiene (PBHT), dinitroanisole, and mixtures thereof.

7. The smoke composition according to claim 4, wherein the binder is present and is selected from the group consisting of thermoplastic resins, polyurethane resin, epoxy resins, hydroxytelechelic polybutadiene (PBHT), dinitroanisole, and mixtures thereof.

8. The smoke composition according to claim 1, wherein the smoke composition comprises (proportions relative to the total weight of the smoke composition): 15% of magnesium, 8% of potassium perchlorate, 54% of superchlorinated polyvinyl chloride, 21% of polyurethane resin, and 2% of graphite.

9. The smoke composition according to claim 1, wherein the smoke composition comprises (proportions relative to the total weight of the smoke composition): 20% of calcium silicide, 29% of potassium nitrate, 49% of superchlorinated polyvinyl chloride, and 2% of graphite.

10. The smoke composition according to claim 1, wherein the smoke composition comprises (proportions with respect to the total weight of the smoke composition): 20% of magnesium, 10% of potassium perchlorate, and 70% of superchlorinated polyvinyl chloride.

11. The smoke composition according to claim 1, wherein the smoke composition comprises (proportions relative to the total weight of the smoke composition): 20% of magnesium, 20% of potassium perchlorate, and 60% of superchlorinated polyvinyl chloride.

12. The smoke composition according to claim 1, wherein upon combustion the superchlorinated polyvinyl chloride generates an aerosol of carbon particles having particle sizes between 0.8 to 10 μm.

Description

(1) FIG. 1a shows the evolution of the masking coefficient for the wavelength range of 3 to 5 μm for the composition according to Example 1, wherein the abscissa axis represents the time in seconds, while the ordinate axis represents the masking coefficient in %;

(2) FIG. 1b shows the evolution of the masking coefficient for the wavelength range of 8 to 12 μm for the composition according to Example 1, wherein the abscissa axis represents the time in seconds and the ordinate axis represents the masking coefficient in %;

(3) FIG. 2a shows the evolution of the masking coefficient for the wavelength range of 3 to 5 μm for the composition according to Example 2, wherein the abscissa axis represents the time in seconds and the ordinate axis represents the masking coefficient in %;

(4) FIG. 2b shows the evolution of the masking coefficient for the wavelength range of 8 to 12 μm for the composition according to Example 2, wherein the abscissa axis represents the time in seconds and the ordinate axis represents the masking coefficient in %;

(5) FIG. 3a shows the evolution of the masking coefficient for the wavelength range of 3 to 5 μm for the composition according to Example 3, wherein the abscissa axis represents the time in seconds and the ordinate axis represents the masking coefficient in %;

(6) FIG. 3b shows the evolution of the masking coefficient for the wavelength range of 8 to 12 μm for the composition according to Example 3, wherein the abscissa axis represents the time in seconds and the ordinate axis represents the masking coefficient in %;

(7) FIG. 4a shows the evolution of the masking coefficient for the wavelength range of 3 to 5 μm for the composition according to Example 4, wherein the abscissa axis represents the time in seconds and the ordinate axis represents the masking coefficient in %;

(8) FIG. 4b shows the evolution of the masking coefficient for the wavelength range of 8 to 12 μm for the composition according to Example 4, wherein the abscissa axis represents the time in seconds and the ordinate axis represents the masking coefficient in %.

(9) A number of compositions according to the invention have been tested to check their masking performance in infrared wavelength ranges of both 3 to 5 μm and 8 to 12 μm.

(10) All the compositions were made according to one or other of the following methods: Dry way, i.e. dry mixing of the various constituents and then compression. This method is used when the composition is free of binder, i.e. for Examples 2, 3 and 4. Wet way, i.e. mixing of solid species with the binder in liquid form, kneading, granulation and then drying. This method is used when the composition comprises a binder, i.e. for Example 1.

(11) The infrared masking tests were carried out in a tunnel equipped with a cold source, a hot source and two thermal cameras (1 camera 3-5 μm and 1 camera 8-12 μm). The cold source is a steel plate at room temperature. The hot source is a black-body source having a temperature of about 200° C. The masking is evaluated by comparing the effect of the passage of the smoke in front of the heat sources (cold and hot) on the temperature seen by the thermal cameras.

EXAMPLE 1

(12) The following composition was prepared (proportions of constituents relative to the total weight of the composition): 15% of magnesium 8% of potassium perchlorate, 54% of superchlorinated polyvinyl chloride, 21% of polyurethane resin, 2% of graphite.

(13) FIG. 1a shows the masking performance of this composition with respect to infrared radiation in the range 3 to 5 μm.

(14) It is found that this composition provides masking of more than 50% over a period of time of 80 seconds. By way of comparison, the composition described by the patent FR2583037 (chlorinated naphthalene carbon generator) ensures masking of approximately 60% for 40 seconds on a close configuration (substantially the same block weight).

(15) FIG. 1b shows the masking performance of this same composition with respect to infrared radiation in the range 8 to 12 μm.

(16) It is found that the masking is greater than 50% for a duration of more than 40 seconds. By way of comparison, the composition described by the patent FR2583037 (chlorinated naphthalene carbon generator) ensures masking of approximately 60% for 40 seconds on a close configuration (substantially the same block weight).

EXAMPLE 2

(17) The following composition was prepared (proportions of constituents relative to the total weight of the composition): 20% of calcium silicide, 29% of potassium nitrate, 49% of superchlorinated polyvinyl chloride, 2% of graphite.

(18) FIG. 2a shows the masking performance of this composition with respect to infrared radiation in the range 3 to 5 μm.

(19) It is found that this composition provides masking of more than 40% over a period of time of 70 seconds.

(20) FIG. 2b shows the masking performance of this same composition with respect to infrared radiation in the range 8 to 12 μm.

(21) It is found that the masking is greater than 30% for a duration of more than 80 seconds.

(22) These performances are less than those of the composition according to Example 1 in terms of masking performance but remain interesting. The masking time is greater.

EXAMPLE 3

(23) The following composition was prepared (proportions of constituents relative to the total weight of the composition): 20% of magnesium 10% of potassium perchlorate, 70% of superchlorinated polyvinyl chloride.

(24) FIG. 3a shows the masking performance of this composition with respect to infrared radiation in the range 3 to 5 μm.

(25) It is found that this composition provides masking of more than 65% over a period of time of 50 seconds.

(26) FIG. 3b shows the masking performance of this same composition with respect to infrared radiation in the range 8 to 12 μm.

(27) It is found that the masking is greater than 30% for a duration of more than 50 seconds.

EXAMPLE 4

(28) The following composition was prepared (proportions of constituents relative to the total weight of the composition): 20% of magnesium 20% of potassium perchlorate, 60% of superchlorinated polyvinyl chloride.

(29) FIG. 4a shows the masking performance of this composition with respect to infrared radiation in the range 3 to 5 μm.

(30) It is found that this composition provides masking of more than 40% over a period of time of 60 seconds.

(31) FIG. 4b shows the masking performance of this same composition with respect to infrared radiation in the range 8 to 12 μm.

(32) It is found that the masking is greater than 30% for a duration of more than 70 seconds.

(33) The masking performances obtained (in terms of rate and duration) are interesting.