RU2611506C1 - Heat-resistant gas-generating composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention refers to heat-resistant gas-generating compositions, used and operated in a temperature range of minus (70 ± 3)°C to plus (155 ± 5)°C. The gas-generating composition comprises an oxidant - 1,3,5-trinitro-1,3,5-triasatcyclohexane or mixture of 1,3,5-trinitro-1,3,5-triasatcyclohexane and 1,3,5,7-tetranitro-1, 3,5,7-triasatcyclohexane at a ratio of 3:1, respectively, a binder - polyvinylbutyral, plasticizer - dibutyl phthalate, processing aids - paraffin, oleic acid, technical carbon and zinc stearate.

EFFECT: invention provides reduction of condensed combustion products and higher operating temperatures.

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Description

The invention relates to heat-resistant gas-generating compositions used in pyro-mechanical devices and operated in the temperature range from minus (70 ± 3) ° C to plus (155 ± 5) ° C.

Known gas-generating compositions [1, 2] based on an oxidizing agent - ammonium perchlorate, metal fuel - aluminum, fuel - chlorine-containing compounds and gas-generating additives - ammonium chloride. Chlorine-containing components in the composition are the main sources of aggressive gases. And the presence of metallic fuel leads to the appearance of a large number of condensed combustion products.

Compositions based on an oxidizing agent - ammonium nitrate of the ZhV brand and a combustible binder - methylpolyvinyltetrazole [3, 4] do not contain toxic and condensed compounds in the combustion products. However, compositions with an ammonium nitrate content of less than 60 wt. % do not provide high performance. The content of ammonium nitrate above 60 wt. % when burning the composition leads to the formation of a continuous layer of a melt of ammonium nitrate on the combustion surface, which is the reason for the low burning rate of the composition and the long delay time of its ignition. In addition, methylpolyvinyltetrazole is used in gas generating compositions, which, when burned, leads to the formation of condensed combustion products (soot) [5].

Closest to the proposed invention is a gas generating composition [6], adopted as a prototype containing potassium nitrate, novolac phenol-formaldehyde resin, basic magnesium carbonate and ammonium oxalic monohydrate.

The disadvantages of the prototype:

- low operating temperature (not more than 50 ° C);

- the presence of a significant amount of condensed combustion products resulting from the use of potassium nitrate.

The objective of the invention is to develop a gas-generating composition that allows to reduce the formation of condensed combustion products while increasing thermal stability and maintaining high performance.

The solution to this problem is due to the fact that the heat-resistant gas-generating composition containing an oxidizing agent, a binder and processing aids is characterized in that it contains 1,3,5-trinitro-1,3,5-triazacyclohexane or a mixture of 1.3, 5-trinitro-1,3,5-triazacyclohexane and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane at a ratio of 3: 1, respectively, the binder is polyvinyl butyral, technological additives are dibutyl phthalate, technical carbon, zinc stearate, paraffin and oleic acid in the following ratio of components wt. %:

Polyvinyl butyral 13.7-14.4 Dibutyl phthalate 3.6-4.0 Paraffin 0.8-1.0 Oleic acid 0.8-1.0 Technical carbon 0.3-0.5 1,3,5-trinitro-1,3,5-triazacyclohexane or mixture of 1,3,5-trinitro-1,3,5-triazacyclohexane and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane with a ratio of 3: 1, respectively 80.8-79.1 Zinc Stearate (in excess of 100%) 0.4-0.6

The mass fraction of all components (except zinc stearate) in the amount is 100%, zinc stearate is introduced into the composition in excess of 100% with respect to the composition. 1,3,5-trinitro-1,3,5-triazacyclohexane and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane as oxidizing agents reduce the content of toxic combustion products.

Gas generating compositions with 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane as an oxidizing agent do not give reliable ignition at negative operating temperatures (minus 70 ° C). Compositions with a mixture of 1,3,5-trinitro-1,3,5-triazacyclohexane and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane at a ratio of 1: 1 (mass) have the worst mechanical strength (40-50%) than the proposed composition of the oxidizing agent (3: 1 (mass)). The increase in the content of oxidizing agent in the composition above 80.8% wt. will lead to a decrease in the content of the binder and, consequently, to a deterioration in the strength properties of the material. With an increase in the content of the binder above 14.4% wt. the composition has good strength properties, but at the same time, the values of performance and specific gas productivity are markedly reduced.

Dibutyl phthalate provides manufacturability of mass processing and mechanical strength of the material. When the content of dibutyl phthalate is less than 3.6% wt. strength properties of the material are noticeably deteriorated. The remaining technological additives reduce external friction and facilitate the process of continuous pressing, reducing their number less than 2.3% wt. increases the risk of pressing operations. Physico-mechanical properties of the prototype, the proposed composition and composition outside the boundary conditions are shown in table 1.

The table shows that the proposed composition (samples 1, 2, 3) can reduce the content of condensed combustion products in comparison with the prototype by about 300 times, increase the value of specific gas production from 410 to 487 nl / kg, ensure high performance and operating temperature, namely, up to 155 ± 5 ° C (the prototype is not more than 50 ° C).

An increase in the binder content (more than 14.4% wt.), A decrease in the content of oxidizing agent (less than 79.1% wt.) And an increase in the content of all technological additives in the composition (above 7.1% wt.) Lead to a decrease in working capacity and a decrease in the specific value gas production (sample 5). With a decrease in the binder content (less than 13.7% wt.), An increase in the content of the oxidizing agent (more than 80.8% wt.) And a decrease in the content of all technological additives in the composition (less than 7.1% wt.), High performance characteristics of the composition and greater the value of specific gas production (sample 4). However, this does not provide sufficient strength properties of the product, in addition, the production of a composition of this type is technologically dangerous (high external friction).

LITERATURE

1. Patent RU 2401254 "Gas-generating fuel for downhole equipment", C06D 5/06, C06B 29/22, publ. 10/10/2010.

2. Patent RU 2395482 "Gas-generating fuel for downhole tools", C06D 5/06, C06B 29/22, publ. 07/27/2010.

3. Patent RU 2481319 "Solid propellant gas generating composition", C06D 5/06, C06B 31/28, publ. 05/10/2013.

4. Patent RU 2423339 "Solid fuel gas-generating composition based on ammonium nitrate", C06D 5/06, C06B 31/32, publ. 07/10/2011.

5. Patent RU 2444505 "Gas-generating composition based on ammonium nitrate", C06D 5/06, C06B 31/32, publ. 03/10/2012.

6. Patent RU 2151135 "Gas-generating composition", C06D 5/06, A62D 1/06, publ. 06/20/2000.

Claims (2)

Heat-resistant gas-generating composition containing an oxidizing agent, a binder and processing aids, characterized in that it contains 1,3,5-trinitro-1,3,5-triazacyclohexane or a mixture of 1,3,5-trinitro-1,3,5 as an oxidizing agent triazacyclohexane and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane with a ratio of 3: 1, respectively, the binder is polyvinyl butyral, technological additives are dibutyl phthalate, industrial carbon, zinc stearate, paraffin and oleic acid in the following the ratio of components, wt.%: Polyvinyl butyral 13.7-14.4 Dibutyl phthalate 3.6-4.0 Paraffin 0.8-1.0 Oleic acid 0.8-1.0 Technical carbon 0.3-0.5 1,3,5-trinitro-1,3,5-triazacyclohexane or a mixture of 1,3,5-trinitro-1,3,5-triase- cyclohexane and 1,3,5,7-tetranitro 1,3,5,7-tetraazacyclooctane at 3: 1 ratio, respectively 80.8-79.1 Zinc Stearate (in excess of 100%) 0.4-0.6