RU2353605C1 - Pyrotechnical moulding composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to pyrotechnic compositions. Pyrotechnical moulding composition for generating masking smoke screen contains mixture of chlorparaffin powder and liquid chlorparaffin with ratio1:(2.4 - 3.3), aluminium powder as metal fuel and smoke-generator - zinc oxide or zinc white.

EFFECT: ensuring generation of dense smoke screen with higher masking ability, absorbing laser and infra-red radiation.

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Description

The invention relates to pyrotechnic compositions, during combustion of which an aerosol is generated, forming a smoke screen in air, used for setting masking curtains.

The level of this technical field is characterized by the smoke-forming composition described in the invention JP No. 53-46884, C06D 3/00, which contains (wt.%):

alkali metal nitrate 6-10 jute coal 1-3 powdered chloroparaffin 8-17 liquid chlorinated paraffin 8-13 zinc oxide 25-40 pyroxylin 25-35

The disadvantage of the described composition is its lack of technology due to its unsuitability for high-performance injection molding technology and because of the multicomponent composition, the effect on the purpose of each is difficult to observe in industrial production in serial industrial production.

In this composition, chlorine paraffin powder is used as a technological additive of a relatively low content, which determines its low masking ability.

More perfect is the molding composition according to the patent DE 2451701, C06D 3/00, 1976, which for most of the matching features is selected as the closest analogue to the proposed composition.

Known injection smoke-forming metal chloride composition includes a mixture of chloroparaffin powder and liquid chloroparaffin in an optimized ratio with a total content of 20-90 wt.% In the composition, metallic fuel in the form of a metal powder or metal oxide and zinc oxide as a smoke generator.

According to the description of the known composition, it may contain the following mixture of powders (wt.%): 20Mg + 45ZnO; 20Al + 45ZnO; 30Al; 20Al; 5Al + Ca ₂ Si.

A disadvantage of the known composition is flame burning due to the imbalance in the mass ratio of the components, which determines a low masking ability.

Soot formed by burning a known composition remains in the slag, since the decomposition of chloroparaffins, in addition to the main chlorinating agent - chlorine hydrogen, forms a carbon slag framework.

Another disadvantage that limits the use of the known over-compacted smoke-forming composition in combat charges for their intended purpose is the instability of combustion at temperatures below minus 50 ° C.

The problem to which the present invention is directed is to increase the functional reliability and purpose of the universal smoke-forming composition.

The required technical result is achieved in that the pyrotechnic molding composition for the formation of a smoke mask contains a mixture of chloroparaffin powder and liquid chloroparaffin, aluminum powder as a metal fuel and smoke, according to the invention, it contains chloroparaffin powder and liquid chloroparaffin in the ratio 1: (2,4- 3.3), and as a smoke generator - zinc oxide or zinc white in the following ratio of components (wt.%):

chloroparaffin powder 40-48 liquid chlorinated paraffin 12-20 aluminum 5-9 zinc oxide or zinc white 31-35

Distinctive features ensured the formation of a dense curtain of smoke with increased masking ability, an additional property of which is the absorption of electromagnetic radiation with a wavelength of 1.06 and 1.2 μm, laser and infrared (IR) radiation, respectively.

A mixture of powdered chloroparaffin (C ₂₅ H ₃₀ Cl ₂₂ ) and liquid chloroparaffin (C ₁₈ H ₃₂ Cl ₆ ) is a supplier of the HC1 chlorinating agent for the formation of metal chlorides, as well as pyrolysis carbon black, the particles of which are half the size of the incident wave of laser and infrared radiation. This ensures their absorption, significantly reducing the reflected signal, which in electronic means of detection and guidance is not identified with the protected target.

The content of liquid chloroparaffin in the amount of 12-20 wt.% Is necessary to ensure injection molding technology for the manufacture of the composition, when at a temperature of 50 ° C the whole composition is completely wetted, poured into the body of the product.

When the content of liquid chloroparaffin is less than 12 wt.%, The composition is viscous, poorly poured, therefore, it is necessary to heat more, which increases the risk of ignition in the workplace.

When the content of liquid chloroparaffin in the composition exceeds 20 wt.%, The viscosity of the mass sharply increases, the processing of which is not technologically advanced due to the high temperature of its heating and the long solidification time of the manufactured charges, the flame burning rate of which increases. As a result, a lot of slag and little smoke is formed.

The optimized mass content in the composition of liquid chloroparaffin and powder chloroparaffin in a ratio of 1: (2.4-3.3) ensures the plasticity of the mixture for processing.

When the content of chlorparaffin powder in the amount is less than 40 wt.%, The chlorinating agent is not enough to form smoke of a given density with the required masking ability.

A content of more than 48 wt.% Of chlorine paraffin in the composition requires the introduction of a proportionally larger amount of liquid chloroparaffin, which determines a decrease in the mass of metallic fuel and, as a result, a decrease in chlorides. As a result, the ballast of chloroparaffins is formed, and most importantly, smoke formation decreases.

The aluminum powder dispersed in the composition serves as a metal fuel to create aluminum chlorides forming a smoke cloud. In addition, the active burning of aluminum heats zinc oxide to activate oxygen substitution with oxidizing agents, in which zinc chlorides are formed - the main smoke forming agent.

When the content of aluminum powder is less than 5 wt.%, The combustion temperature of the composition is insufficient to make full use of the structural components for their intended purpose, many slags are formed, smoke formation is unsatisfactory. Charge burning is unstable.

The content of aluminum powder in the composition of more than 9 wt.% Is the cause of flame combustion, in which the necessary amount of smoke-forming metal chlorides is not formed due to the fact that aluminum burns.

The introduction of zinc oxide into the composition of less than 31 wt.% Leads to an increase in the burning rate and a decrease in the lifetime of smoke, therefore, it requires a higher consumption of smoke-forming composition.

The content of zinc oxide in the composition of more than 35 wt.% Complicates its ignition in full from the developed combustion temperature, therefore, a ballast inert component is formed, which reduces the efficiency of the smoke-forming composition.

Therefore, each essential feature is necessary, and their combination is sufficient to achieve a novelty of quality that is not inherent in the signs of disunity, that is, the technical problem posed in the invention is not solved by the sum of the effects, but by a new effect of the sum of the attributes.

The preparation of the smoke-forming composition is carried out on conventional mixers according to the accepted technology for mixing pyrotechnic compositions.

A measured quantity of ingredients is loaded into the mixer according to the optimized mass ratio: powder chlorine paraffin brand ХП-1100 in an amount of 40-48 wt.%, Aluminum powder grade PA-4 or АСД-4 in an amount of 5-9 wt.%, Zinc oxide (zinc white BTsO, BTs-1 or BTsO-M grades according to GOST 202) and liquid chlorine paraffin brand ХП-470, which are mixed for 20 minutes for uniform dispersion in volume.

From the prepared mass, heated to a temperature of 50 ° C, measured charges are poured directly into the body of the products used to set the smoke screens.

The use of industrially produced zinc oxide as zinc oxide reduces the consumer cost of charges, while the impurities contained in them do not significantly affect the functioning of the composition and the masking ability of the generated aerosol.

The optimal ratio of the components in the proposed smoke-forming composition was calculated according to the mathematical model of the experimental design and tested for proper operation in the experimental products on bench tests.

Table 1 below shows typical examples of compositions with a boundary content of components of the optimized ranges within the range of the mass content of components and beyond.

Qualitative and quantitative composition of the tested charges.

Table 1 Components The content of components, wt.% COMPOSITIONS one 2 3 four 5 Prototype Chloroparaffin Powder 38 40 45 48 fifty 14-76 Chloroparaffin liquid 22 twenty fifteen 12 10 6-14 Aluminum powder 10 9 6 5 3 20-30 Zinc oxide thirty 31 34 35 37 45

Comparative purpose and functional characteristics of formulations 1-5 are shown in table 2.

The main technical characteristics of the compositions.

table 2 Indicators COMPOSITIONS one 2 3 four 5 Prototype Masking ability, m ² / g at φ = 60-80% 3.6-4.2 5.0-7.4 5.0-7.4 5.0-7.4 3.2-3.8 3,5 Burning rate, m / s 0.35 0.28 0.25 0.18 0.13 0.1 Smoke generating ability,% 70 85 85 85 60 70 Number of slags,% thirty fifteen fifteen fifteen 40 thirty Working time, min 4.8 5.8 6.0 6.3 7.0 8-10 The length of the masking curtain, m 450 670 650 630 350 450-500

From table 2 it follows that the use of a smoke-forming composition containing metal fuel in the form of aluminum powder in an amount of more than 9 wt.% And less than 5 wt.% Is impractical, as this leads to a sharp deterioration in its smoke-generating and masking ability.

A similar effect is observed with an increase in the proportion of zinc oxide over 35 wt.%.

When the content of powder and liquid chlorinated paraffins beyond the optimized limits of the content ranges, smoke formation and the masking ability of the formed curtain are reduced.

A content of zinc oxide of less than 31 wt.% Dramatically reduces the lifetime of the smoke screen, and more than 35 wt.% Worsens the masking ability of the generated smoke cloud, the density of which decreases due to increased slag formation of the structural components of the composition.

Therefore, the proposed smoke-forming composition is significantly different from the known analogues and productive in its intended use.

A comparative analysis of the proposed technical solution with identified analogues of the prior art, from which the invention does not explicitly follow for a pyrotechnician, showed that it is not known, and taking into account the possibility of industrial serial production of a smoke-forming composition, we can conclude that the patentability criteria are met.

Claims (1)

A pyrotechnic molding composition for the formation of a smoke mask, containing a mixture of chloroparaffin powder and liquid chloroparaffin, aluminum powder as a metal fuel and smoke generator, characterized in that it contains a ratio of chloroparaffin powder and liquid chloroparaffin in the ratio 1: (2.4-3.3) and as a smoke generator - zinc oxide or zinc white in the following ratio of components, wt.%:
chloroparaffin powder 40-48 liquid chlorinated paraffin 12-20 aluminum 5-9 zinc oxide or zinc white 31-35