RU2614721C1 - Pyrotechnic signal composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to pyrotechnics, namely to pyrotechnic signal compositions of red and green lights for use in jet signal cartridges, and can be used in various signaling products. The signal pyrotechnic composition is described, containing strontium or barium nitrate, magnesium, polyvinyl chloride and phenol-formaldehyde resin, characterized in that it additionally comprises barium peroxide in the following ratio (in % by weight): strontium or barium nitrate 39-66, magnesium 8-25, polyvinyl chloride 14-21, phenol formaldehyde resin 5-7, barium peroxide 4-11.

EFFECT: pyrotechnic signal composition with high lighting performance is obtained.

2 cl, 2 tbl

Description

The invention relates to pyrotechnics, and more particularly to pyrotechnic compositions of red and green lights, and can be used for the manufacture of signaling means, in particular in reactive signal cartridges.

Domestic industry produces single-star and multi-star reactive signal cartridges.

A reactive signal cartridge consists of a launch tube with an ignition grate device and a signal rocket placed in it.

The missile is an aluminum case in which the signal and igniter compositions are pressed in, a cardboard ring is placed, and the reactive part (engine) is inserted all the way. The principle of operation of the signal cartridge consists in raising the rocket to the required height due to engine operation, ejecting the engine at the top of the flight path of the rocket, igniting and burning the signal star in the rocket body.

The reactive cartridges used standard signaling compositions of red and green lights containing hexachlorobenzene in the formulation. Currently, the production and use of hexachlorobenzene is prohibited by the UN Convention and the Federal Law of the Russian Federation Federal Law of June 27, 2011 No. 164 for environmental reasons.

In connection with the foregoing, studies have been conducted to replace the standard signal compositions of red and green lights in these products with new compositions that do not contain hexachlorobenzene in the formulation.

There are pyrotechnic signaling compositions containing polyvinyl chloride (PVC) as a chlorine-containing additive.

The signal composition of the red light (US patent No. 8216403 from 01/14/2011) contains the following components (in% by weight):

magnesium 22-38 binder (resin plus hardener) 4-7.5 strontium nitrate 40-60 polyvinyl chloride 11-16

According to the data presented, the luminous intensity of the composition is 3500 cd, the dominant radiation wavelength is 600 nm, and the flame color purity is 80%, which is insufficient for the composition of the red light used in jet cartridges. The known signal composition of the red light (US patent No. 7988801 from 12/12/2008) contains the following components (in% by weight):

magnesium 10-30 boron 5 copper 10 barium nitrate 50-65 polyvinyl chloride 6-12 binder 4-7.5

The disadvantage of this composition is the unstable nature of combustion with the formation of a sufficiently large number of condensed combustion products.

The number of matching essential features as the prototype selected composition according to the patent of the Russian Federation No. 2528257 from 2013, containing in the formulation the following components (in% by weight):

strontium or barium nitrate 37-59 magnesium 12-30 polyvinyl chloride 10-20 phenol formaldehyde resin 4-6 potassium perchlorate 5-17

Compositions made according to the above recipe have a sufficiently high luminous intensity and specific light sum of the flame while at the same time high purity of the color of the flame.

So, samples with a diameter of 19.8 mm of the composition - the prototype of green fire have a light intensity of 2340 ÷ 7440 cd, specific light sum of 1420 ÷ 5360 cd⋅s / g and a flame color purity of 75 ÷ 77%. Samples with a diameter of 19.8 mm of the composition - the prototype of the red light have a light intensity of 4400 ÷ 10850 cd, specific light sum 5690 ÷ 8300 cd⋅s / g and a flame color purity of 88 ÷ 90% depending on the ratio of components in the composition.

The disadvantage of this signal composition, selected as a prototype, is that if it is used in jet cartridges during its combustion (the composition is pressed into an aluminum shell), the burning sample splits into 2 or 3 burning parts. Thus, the transmitted signal is distorted: the signal is single-star or multi-star.

The technical problem to which the present invention is directed is the creation of a pyrotechnic signal composition with high lighting characteristics, capable of burning in a form pressed into an aluminum shell without splitting into burning parts.

The technical result is achieved by the fact that the known pyrotechnic signal composition containing magnesium, strontium nitrate (in the case of red light) or barium nitrate (in the case of green light), polyvinyl chloride, phenol-formaldehyde resin, according to the invention additionally contains barium peroxide, and magnesium is incorporated into as a powder coated with 2-4% phenol-formaldehyde resin in the following ratio of components (in% by weight):

strontium or barium nitrate 39-66 magnesium 8-25 polyvinyl chloride 14-21 phenol formaldehyde resin 5-7 barium peroxide 4-11

Distinctive features provided:

- high values of luminous intensity, specific light sum, purity of the color of the flame;

- combustion of the signal composition pressed into the aluminum shell occurs without splitting, in particular when the 30-mm reactive signal cartridge is operated.

The manufacture of the claimed pyrotechnic composition is carried out according to the following technology:

1. The processing of magnesium powder with a solution of phenol-formaldehyde resin in ethanol with a ratio between the resin and magnesium powder from 10:90 to 20:80 per dry substance, that is, 2-4% of the resin from the formulation is used for processing magnesium powder. The amount of phenol-formaldehyde resin required for processing magnesium powder (3 ± 1,%) depends on the specific surface of the latter. So, when using MPF-1 GOST 6001 brand magnesium powder in the formulation (specific surface area determined by the Deryagin instrument is 0.039 m ² / g), 2% (dry matter) of phenol-formaldehyde resin is sufficient for processing, and when using the composition of magnesium brand powder in the formulation MPF-4 (specific surface - 0.144 m ² / g) requires 4% phenol-formaldehyde resin. Magnesium processing is carried out for 5 ÷ 10 minutes depending on the type of mixer).

2. Drying the treated powder to a moisture mass fraction of not more than 0.1% (carried out with the mixer running with air blowing under a pressure of 2 kgf / cm ² for ~ 20 minutes in a 35CB mixer).

3. Granulation of the processed magnesium powder through a grid 2 GOST 6613-86 (granulation time 3 ÷ 5 minutes).

4. Download all dry components (including the remainder of the solid phenol-formaldehyde resin - 3 ÷ 5%) into the mixer and mix for 5 minutes (in a 6LS mixer), 7 minutes (in a 35 CB mixer) until a homogeneous mass is obtained.

5. Adding ethyl alcohol to the mixer and mixing the composition until smooth (~ 5 minutes).

6. The operation of drying (5 ÷ 10 minutes in the mixer under air pressure 1 ÷ 15 kg / cm ² ).

7. Granulation of the composition through the mesh No. 1.25 ÷ 2 (~ 5 minutes).

Another preparation option is also possible: in operation No. 5, instead of ethyl alcohol, a solution of phenol-formaldehyde resin in ethyl alcohol is used, and in operation No. 4, solid phenol-formaldehyde resin is not introduced.

The components of the proposed structure have a raw material base and are produced by domestic industry.

The claimed pyrotechnic composition has chemical resistance and physico-chemical stability.

The preparation of samples of the compositions was carried out by pressing into aluminum shells ∅24.65 mm and a height of 75 mm by the method of blind pressing. The pressing pressure of both the proposed composition and the prototype was 2500 kgf / cm ² .

Bench tests of samples (checkers) with the determination of lighting characteristics were carried out in a small model camera according to GOST 2389.

Tests of the compositions in flight conditions in 30-mm high-precision reactive signal cartridges (RSPPT) of index 7С22 (red light) and index 7С22-01 (green light) were carried out at the training ground of the Scientific Research Institute of Applied Chemistry.

The recipes of the tested characteristics of the compositions and prototypes and their measured technical characteristics, measured in bench and flight conditions, are shown in tables 1 and 2.

The experimental data presented in tables 1 and 2, the results of flight tests of 30-mm RSPPT, equipped with stars of the proposed composition and prototype, indicate that after the operation of the product:

- when the stars of the prototype burn in flight, they split into several parts, which leads to a distortion of the fire signal;

- when the stars of the proposed composition of red and green lights burn in flight, they do not split, which allows them to be used as a fire signal in a 30-mm RSPPT.

Also from the experimental test data of samples of the proposed composition and the composition of the prototype in bench conditions (tables 1 and 2) it can be seen that the proposed composition exceeds the prototype in terms of color purity, light intensity and specific light sum of the flame.

Claims (3)

1. Pyrotechnic signal composition containing strontium or barium nitrate, magnesium, polyvinyl chloride and phenol-formaldehyde resin, characterized in that it additionally contains barium peroxide in the following ratio of components (in% by weight): strontium or barium nitrate 39-66 magnesium 8-25 polyvinyl chloride 14-21 phenol formaldehyde resin 5-7 barium peroxide 4-11 2. The pyrotechnic signal composition according to claim 1, characterized in that magnesium is introduced into the composition in the form of a powder pretreated with phenol-formaldehyde resin in a ratio,% by weight, from 10:90 to 20:80 between the phenol-formaldehyde resin and magnesium powder.