RU2233258C2 - Ignition composition - Google Patents

Abstract

FIELD: ignition materials.

SUBSTANCE: invention relates to ignition compositions used for electric igniters of dropping type and for electric igniters as press-fitted form. Invention proposes the ignition composition that consists of powder or granulated barium azide. Invention is directed for the enhancing precision in response of electric igniters and reducing toxicity of the composition.

EFFECT: improved and valuable properties of composition.

1 tbl

Description

The invention relates to pyrotechnic compositions, in particular igniters, and can be used for equipping products (igniters and electric detonators, igniter compositions for self-defense equipment, etc.).

Flammable compositions are known, including oxidizing agents, combustibles and additives, for example, a composition comprising potassium chlorate, antimony sulfide and mercury fulminate (Bubnov P.V. Initiating explosives. M., Oborongiz, 1940, p.23.)

The disadvantage of these compounds is the high toxicity of the starting compounds and explosion products.

Flammable compositions are known, which are mechanical mixtures of an oxidizing agent and a fuel. Used in powder form and granulated with varnish in the form of grains (OST B 84-2462-93. Ignition compositions).

Lead compounds, metals are used as fuel, lead red oxide, lead dichromate, chlorate or potassium perchlorate are used as oxidizing agents. When granulating, rosin varnish with a mass fraction of 8-18% or varnishes 3-5% - colloxylin or rubber varnish is used.

Depending on the number of components (not including rosin, rubber or colloxylin), there may be two- and three-component compositions. Rosin, rubber or colloxylin are included in an amount of from 0.6 to 5% in excess of 100% to improve the flowability of the composition.

The following igniter compositions, wt.%, Are presented in table 1.

When using the compositions in drip type electric igniters, according to the generally accepted technology, all components are crushed, wiped through a net, dosed, mixed. The prepared mixture is metered into the polymer solution to the desired consistency.

In the case of applying composition I, per 100 g of a 3% varnish, 340 g of the composition is taken; in dry form, the content of colloxylin is 0.9% in excess of 100%. Dipping the glow bridge into the resulting pasty mixture, apply 2 layers of igniter composition, followed by drying of each layer. In addition to the main layers, a layer of a composition is applied that gives a powerful and burning force of fire (for example, iron oxide in a nitro-varnish, etc.), after which it is varnished for water resistance by nitro-varnish and dried. The finished electric igniter is inserted into the equipped shell of the electric detonator.

In the case of use in pressed-type igniters, the composition is poured into the shell, in the recess of which there is an incandescent bridge, and pressed. In this case, composition II is used with a weight of 42-44 mg at a pressing pressure of 450 ± 50 kg / cm.

The disadvantages of the above igniter compositions include:

- a significant variation in response time due to the heterogeneity of the particle size distribution of the multicomponent mixture and the possibility of its separation in the process of applying the droplet;

- a relatively high sensitivity to shock;

- toxicity of the composition;

- the complexity of the composition;

- the high complexity of its preparation (the preparation process includes operations: for each component - grinding, sieving, drying, grinding control, dosage, and then mixing the components).

An additional drawback of such compositions is the different sedimentation rate of the components of the composition in the polymer mixture, therefore, to maintain the constancy of the composition, the fire-hazardous mixture is constantly mixed.

The technical result of the invention is improving the accuracy of operation of electric igniters, reducing the toxicity of the composition, reducing the complexity of its preparation.

The technical result is achieved by the fact that as an ignition composition, powder or granular barium azide Ba (N ₃ ) _{2 is} proposed.

Barium azide with a basic substance content of at least 96% is obtained by the interaction of sodium azide with barium perchlorate. The granular composition contains 100% barium azide; colloxylin (2.0 ± 1.0)% in excess of 100%.

Colloxylin is introduced during granulation of barium azide (3-5)% varnish.

The preparation of the composition consists of the operation of drying the composition.

The technology for applying a “droplet” with barium azide or with a known ignition composition is similar, however, when preparing a paste for applying the composition to 100 g of a 3% varnish, 100-130 g of barium azide are taken. In dry form, the polymer content is (2.3-3.0)% in excess of 100%.

Powdered or granular barium azide is pressed into the shell at the same pressure as the known composition. The consumption of barium azide per product is 1.5 times less than the composition used II, and is 28-30 mg.

Tests of the ignition composition based on barium azide showed high reliability of operation of electric detonators, a smaller variation in response time compared to the analogue, satisfactory results when tested for safe and long-term igniting current.

An advantage of the composition is the absence of the phenomenon of sedimentation of particles in a polymer solution upon receipt of a droplet.

The test results and comparisons of the known and proposed formulations are given in table 2.

As can be seen from table 2, the spread in the response time of products using barium azide is 1.7-2.4 ms depending on the incandescent bridge, which is approximately 2 times lower than the required standard value of -4 ms.

When barium azide is used as an ignition composition in pressed articles, the weight of the sample is 1.5 times reduced in comparison with the known composition II at the same pressing pressure. Reduces pressure dispersion by 15% when triggered.

Comparative tests of products for sensitivity to mechanical stress showed a lower sensitivity to shock of products based on barium azide compared to products with composition I. Tests were carried out on the Gronov pile, device 2, load 2 kg, height 10 cm.

Barium azide and explosion products are less toxic than lead compounds and belong to the second less dangerous class of harmful substances.

Replacing the known multicomponent compositions with a single component significantly reduces the preparation of the igniter composition and consists of a drying operation, excluding the operations: grinding, sieving, dosage of each component and their mechanical mixing.

A simple, less laborious in preparation and less toxic igniter composition has been proposed, the use of which increases the accuracy of the operation of electric igniters.

Sources of information

1. Bubnov P.V. Initiating explosives. M., Oborongiz, 1940.

2. OST B 84-2462-93 Ignition compositions.

Claims (1)

An igniter composition, characterized in that it consists of powder or granular barium azide.