HIGH YIELD COOL GAS GENERATING COMPOSITION SUITABLE FOR INFLATION SYSTEMS

Abstract

HIGH YIELD COOL GAS GENERATING COMPOSITION SUITABLE FOR INFLATION SYSTEMS The invention relates to a novel cool gas-generating composition designed for applications in inflation systems, such as crew module uprighting systems and inflatable aerodynamic decelerators. This composition utilizes calcium azotetrazolate (CZT) as a high-nitrogen fuel, triaminoguanidine nitrate (TaGN) as a nitrogenous oxidizer, and optionally includes potassium perchlorate (KP) as a burn rate enhancer, along with a fluoro elastomer or cellulose derivative as binder. The formulation achieves a high gas yield of 500-600 mL/g at standard temperature and pressure (STP), with a combustion flame temperature of 850 K or lower. Importantly, the combustion products are non-toxic and filterable, ensuring safety during use. The invention addresses the limitations of conventional gas-generating compositions by providing a solution that generates high residual pressure with low gas temperatures, making it suitable for various aerospace applications. Figure. 3.

Specification

Description:FIELD OF INVENTION
[0001] The present invention relates to a high-yield 'cool gas' generating composition, suitable for inflation systems, that is free from corrosive or toxic combustion products and contains filterable condensable matter.
BACKGROUND OF INVENTION
[0002] Gas generators are essential components in a wide range of inflation systems, such as those used in crew module uprighting systems, inflatable aerodynamic decelerators, and inflatable habitats in the aerospace industry. Their primary function is to produce a controlled, rapid release of gas to inflate devices in emergency situations, ensuring safety and reliability. The technology behind gas generators focuses on the rapid production of gas through the combustion of solid or liquid propellants. The compositions used in these generators typically consist of a fuel, an oxidizer, and various additives that control the combustion process and manage the by-products.
[0003] Conventional gas generators for airbags and other civilian inflation systems use sodium azide-based compositions (NaN3/MgCl3/KNO3), which have a low gas yield (300-340 mL/g), and their components or decomposition products are either carcinogenic or corrosive. Other researched and reported inflatable systems typically use high-nitrogen derivatives, especially tetrazole- and triazole-based systems, along with a variety of oxidizers such as phase-stabilized ammonium nitrate, metallic nitrates, or nitroguanidine as gas generators. These systems have drawbacks, including high flame temperatures, low to medium gas yield, and high concentrations of condensable matter. Therefore, there is a pressing need to develop a composition that produces a large amount of gas with a very low flame temperature, ideal for inflation systems that require high residual pressure.
[0004] The prior art 'IN326236' discloses a pyrotechnic pressure-generating composition for various high-performance pyro devices used in space applications. It comprises guanidinium azotetrazolate (GZT) as the fuel and ammonium perchlorate (AP) as the oxidizer, along with an energetic binder. The invention is applicable in space, for explosive-actuated, multi-strand cable cutting shut-off valves, mortar-based parachute deployment systems for deceleration of crew modules and burst qualification of nozzle closures for solid rocket motors or liquid engines at sea level. It is also useful in gas pressure-actuated mechanical devices such as power cartridges for cutting cables/diaphragms, large-caliber guns/mortars for accelerating projectiles, and gas pressure generators for applications such as pushing pistons, electric generators, turbines, and pneumatic tools. However, this composition represents a high-temperature (~2500 K), high dp/dt gas generator for mortars and cutters, and it's decomposition products are corrosive (HCl), leading to low residual pressure, making it unsuitable for use as a cool gas generator.
[0005] The prior art 'US3972545' discloses a multi-level cool gas generator suitable for filling inflatable structures in the presence of humans. It is specifically applied to passive restraint cushions designed to provide impact protection for occupants of automotive vehicles. The composition consists of a mixture by mass of 55% sodium azide (NaN₃) and 45% anhydrous chromic chloride (CrCl₃), formed into pellets. This patent describes conventional gas generators with a low gas yield (~300 mL/g) and an inability to produce high gas yields or non-corrosive decomposition products.
[0006] The prior art 'US5872329' discloses non-azide gas generant compositions, which describe high-nitrogen, non-azide gas compositions useful for inflating passenger restraint airbag systems. These compositions comprise an amine salt of triazole or tetrazole as fuel and phase-stabilized ammonium nitrate (PSAN) as an oxidizer. The combination of the amine azole salt and PSAN results in gas generators that are relatively more stable and less explosive, have improved ignitability and burn rates, and generate more gas with fewer solids compared to known gas generator compositions. However, the higher concentration of hydrogen atoms from the use of amine fuels and PSAN increases moisture condensation during combustion, which affects the residual pressure.
[0007] The prior art 'US6210505B1' discloses high gas yield non-azide gas generants, which describe high-nitrogen, non-azide gas compositions useful for inflating passenger restraint airbag systems. These compositions comprise a non-metal salt of triazole or tetrazole as fuel, phase-stabilized ammonium nitrate (PSAN) as a primary oxidizer, a metallic second oxidizer, and an inert component such as clay or mica. The combination of these constituents results in gas generants that are relatively more stable and less explosive, exhibit improved ignitability and satisfactory burn rates, sustain combustion across various combustion pressures at the inflator level, and generate more gas with fewer solids compared to known gas generant compositions. However, this prior art represents a composition based on non-azide fuels (high-nitrogen compounds) with PSAN and metallic oxidizers. The presence of metallic oxidizers results in a higher concentration of solid condensibles and elevated flame temperatures, which limits the applicability of these compositions in cool gas generator systems.
[0008] The prior art 'US6306232B1' discloses thermally stable non-azide automotive airbag propellants, detailing gas generant compositions that incorporate a combination of nitroguanidine, one or more non-azide high-nitrogen fuels, and phase-stabilized ammonium nitrate or a similar nonmetallic oxidizer. Upon combustion, these compositions result in a greater yield of gaseous products per unit mass of gas generant, a reduced yield of solid combustion products, and acceptable burn rates, thermal stability, and ballistic properties. They are particularly suitable for inflating airbags in passenger restraint devices. However, this prior art describes a composition based on nitrogenous salts of bitetrazoles (high-nitrogen compounds) with PSAN, which produces a high flame temperature on the order of 2000 K. Therefore, it is not applicable as a cool gas generator.
[0009] In summary, the existing prior arts present several limitations in achieving a high-yield cool gas-generating composition that is free from corrosive and toxic combustion products while ensuring the presence of filterable condensibles. Many of these compositions exhibit high flame temperatures exceeding 1500 K, coupled with moderate gas yields, which make them unsuitable for cool gas generator systems. Furthermore, the generation of harmful by-products, including solid condensable and corrosive gases, significantly restricts their applicability in safety-critical contexts. To overcome these limitations, a new composition has been developed that possesses desirable qualities, including high gas yield, low combustion flame temperature, reduced concentration of condensable, and higher residual pressure.
OBJECTOF INVENTION
[0010] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
[0011] An object of the present invention is to develop a 'cool gas' generating composition suitable for inflation systems, utilizing Calcium azotetrazolate (CZT) as a high nitrogen fuel, Triaminoguanidine nitrate (TaGN) as a nitrogenous oxidizer, Potassium perchlorate (KP) as a burn rate enhancer, and fluoro elastomer as a binder, ensuring efficient gas production and safe combustion.
[0012] Another object of the present invention is that the proposed gas generating composition achieves a high gas yield of 500-600 mL/g at standard temperature and pressure (STP), while maintaining a combustion flame temperature of 850K or lower, making it suitable for systems requiring cool gas generation.
[0013] Yet another object of the present invention is to develop a high nitrogen gas generating composition that produces non-toxic, non-corrosive, and filterable combustion products, suitable for use in inflation systems and devices such as crew module uprighting systems, Inflatable Aerodynamic Decelerators (IAD), inflatable habitats, etc., comprising a high nitrogen fuel, an organic oxidizer, and a thermally stable binder.
[0014] A further object of the present invention is to formulate a method for preparing cool gas-generant pellets using a wet granulation process, ensuring that the pellets are insensitive to frictional loads > 360N and impact energy > 20J.
[0015] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY OF THE INVENTION
[0016] Disclosed herein is a high-yield cool gas generating composition, useful for applications such as crew module uprighting systems, inflatable aerodynamic decelerators, and inflatable habitats in the aerospace industry. The composition comprises non-azide, high nitrogen heterocyclic compounds as fuel and nitrogen-rich oxidizers. The gas-generating composition of the present invention is capable of self-sustained combustion at moderate pressures, while producing a relatively high gas volume to solid particulate ratio and maintaining very low combustion flame temperatures. Consequently, this composition is highly effective for applications requiring low flame temperature and high residual pressure.
[0017] Non-azide high nitrogen heterocyclic compounds are promising candidates for gas generators due to their high nitrogen-to-carbon ratio. Tetrazole derivatives with nitrogen content greater than 70%, such as azotetrazoles, bistetrazoles, and bitetrazoles, are particularly suitable for gas generator applications. High nitrogen oxidizers, such as guanidine nitrate and triaminoguanidine nitrate, are favorable as oxidizers due to their higher gravimetric nitrogen content, ease of preparation, and reduced production of condensibles.
[0018] The proposed gas generating composition comprises Calcium azotetrazolate (CZT) as a high nitrogen fuel, Triaminoguanidine nitrate (TaGN) as a nitrogenous oxidizer, Potassium perchlorate (KP) as a burn rate enhancer and initiation aid, and fluoro elastomer as a binder, ensuring efficient gas production and safe combustion.
[0019] The proposed high-yield cool gas generating composition exhibits the following desirable qualities upon combustion:
• Gas yield of 500-600 mL/g at standard temperature and pressure (STP);
• Combustion flame temperature of 850K or lower;
• Residual pressure of 0.47-0.55 MPa at room temperature (possible only if natural gases such as N2, CO2, H2, CH4 are present); and
• Non-toxic, non-corrosive, and filterable combustion products.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0020] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0021] Figure 1 illustrates the synthetic procedure for the preparation of calcium azotetrazolate (CZT), according to an embodiment of the present invention.
[0022] Figure 2 illustrates the synthetic procedure for the preparation of Triaminoguanidium nitrate (TaGN), according to an embodiment of the present invention.
[0023] Figure 3 illustrates a pictorial representation of the cool gas generant pellets, according to an embodiment of the present invention.
[0024] Figure 4 illustrates a differential thermogram of the granular composition obtained through Differential Scanning Calorimetry (DSC), according to an embodiment of the present invention.
[0025] Figure 5 illustrates a Total Ion Chromatogram of the cool gas generant composition, according to an embodiment of the present invention.
[0026] Figure 6 illustrates a mass spectrum for the cool gas generant composition, according to an embodiment of the present invention.
[0027] Figure 7 illustrates a pressure - time trace of cool gas generating composition (pellets) upon combustion, according to an embodiment of the present invention.
[0028] Figure 8 illustrates a temperature - time trace of cool gas generating pellets upon combustion, according to an embodiment of the present invention.
[0029] Figure 9 illustrates a pictorial representation of the inflation test conducted on the cool gas generant pellets in a closed vessel, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention may be embodied in several forms, and the details of embodiments of the present invention will be described in the following content with figures. The embodiments described below with reference to the drawings are merely illustrative of the technical solutions of the present disclosure but are not to be construed as limited to the technical solutions of the present disclosure.
[0031] The terms and words used in the following description and claims are not limited to the bibliographical meanings but are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of the present invention is provided for illustration purposes only and not for the purpose of limiting the invention as defined by the appended claims. As used in the description of the invention and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
[0032] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0033] The present invention introduces high-yield 'cool gas' generating composition, suitable for inflation systems, that is free from corrosive or toxic combustion products and contains filterable condensable matter.
[0034] The primary requirement for a cool gas-generating composition is to achieve high residual pressure; that is, upon decomposition, the composition should release stable gases (without rearrangements under varying pressures and temperatures) such as N2, CO2, CH4, and others. Traditional systems, such as airbags and inflation rafts, utilize sodium azide-based compositions since they liberate N2 as the gaseous product. Sodium azide can generate 1.5 moles of N2, whereas high nitrogen non-azide fuels release more than 2 moles of N2 per molecule. This serves as the fundamental principle behind the selection of non-azide high nitrogen fuels like azotetrazoles.
[0035] Specifically, the gas generating composition of the present invention comprises high nitrogen heterocyclic compounds - Calcium azotetrazolate (CZT) as the fuel and Triaminoguanidine nitrate (TaGN) as the nitrogenous oxidizer. Potassium perchlorate is optionally included as a burn rate enhancer and initiation aid, and fluoro elastomer or cellulose derivative are used as binders to provide structural integrity and prevent moisture ingress.
[0036] In a preferred embodiment, the gas-generating composition of the present invention comprises:
• from 45% to 55% by mass of calcium azotetrazolate (CZT);
• from 40% to 55% by mass of triaminoguanidine nitrate (TaGN);
• from 8% to 10% by mass of potassium perchlorate (KP) as option; and
• from 1% to 5% by mass of fluoro elastomer or 1% to 3% of cellulose derivative.
[0037] Both ingredients, namely calcium azotetrazolate and triaminoguanidine nitrate, were synthesized following reported procedures. Calcium azotetrazolate octahydrate is prepared from 5-amino tetrazole monohydrate via oxidative azo coupling followed by double decomposition steps. The hydrated salt is heated to 105°C for 2 hours in a vacuum oven to obtain the desired anhydrous salt (CZT) as the fuel.
[0038] Triaminoguanidine nitrate (TaGN) is prepared from guanidine nitrate through hydrazinolysis under acidic conditions. The resulting TaGN is washed to remove hydrazine and dried at 80°C for 2 hours. Both TaGN and CZT were characterized by their structures using spectroscopic and elemental analysis techniques. The fuel and oxidizer are pulverized and sieved through a 425 µm standard test sieve. The detailed synthetic steps involved are depicted in Figures 1 and 2.
[0039] For a 100 g mixture of the gas-generating composition, 45-55 g of anhydrous calcium azotetrazolate and 45-55 g of triaminoguanidine nitrate are dry blended using paper folding and sieving technique to ensure the homogeneity of the powder mix. The percentage composition of the powder is determined through standard chemical analysis. Subsequently, the powder charge is granulated using a binder solution. The wet granulation is performed with a binder solution in acetone, prepared by dissolving 5 g of binder in 100 mL of acetone. The granulation process employs solvent evaporation; the binder-acetone solution is added in portions to the 100 g powder mix and distributed throughout the mixture. The mixture is stirred until the excess acetone evaporates and the composition-binder solution forms a dough. The formed dough is then granulated by passing it through the respective sieves to achieve well-defined granules of 425 - 710 µm. The dried granules are used to fabricate pellets. An automatic rotary pelleting machine is employed to produce the pellets with a diameter of 7-10 mm, as shown in Figure 3.
[0040] In a preferred embodiment, the paper folding and sieving technique is used to attain a homogenous powder composition mix.
[0041] In another preferred embodiment, the potassium perchlorate (KP) is optionally added into the mixed powder composition to enhance heat output and improve ignitability of the composition.
[0042] The composition demonstrates significant thermal stability, with a decomposition onset temperature of 182°C. The differential scanning calorimetry (DSC) thermogram of the composition, as shown in Figure 4, exhibits a single-stage exothermic decomposition pattern, featuring a shoulder peak that is resolvable at low heating rates (less than 5°C/min).
[0043] Evolved gas analysis of the present composition was conducted using pyrolysis gas chromatography-mass spectrometry (GC-MS) at a temperature of 300°C. The total ion chromatogram (TIC), illustrated in Figure 5, reveals two peaks that are not well resolved, occurring at a retention time of 2.05 minutes. The mass spectrum obtained at this specific retention time indicates the presence of nitrogen gas (N2, m/z 28) as the major peak, as depicted in Figure 6.
[0044] The granular composition was found to be insensitive to impact energy > 20J and friction load >360N, making it safe for storage, processing, and transportation. Analysis of the decomposition products revealed that calcium oxide (CaO) is the major product, which can be easily filtered out in the inflatable device.
[0045] The typical issues associated with conventional gas generating formulations, such as low gas yield and elevated gas temperatures, are addressed by proposing a novel gas-generating composition that employs non-azide high nitrogen heterocyclic compounds as fuel and oxidizers for applications in the aerospace industry, including crew module uprighting systems and inflatable aerodynamic decelerators (IAD). This proposed cool gas-generating composition consists of calcium azotetrazolate (CZT) as the fuel, triaminoguanidine nitrate (TaGN) as the nitrogenous oxidizer, and fluoro elastomer as the binder.
[0046] The compositions of the present invention produce substantially non-toxic gases, particularly molecular nitrogen, in amounts that are significantly greater than those generated by conventional gas-generating compositions. Additionally, they exhibit higher residual pressures and lower gas temperatures. The key features of the cool gas-generating compositions are summarized in Table 1.


Table 1: Properties of high-yield cool gasgenerating composition
Parameter Value
Gas yield, mL/g 500-600
Gas temperature, K <850
Combustion gas temperature, K (after cooling through metallic mesh 106µ) 450
Friction Sensitivity, N >360
Impact Sensitivity, J >20
Calorific value, cal/g 680 ± 60
Burn rate, mm/s at 40 bar 9.88 ± 0.90
Combustion gas constituents N2 (major)

[0047] The performance and application of the composition as a cool gas-generating agent were evaluated using closed vessel tests and inflation device tests. The pressure output of the pelleted composition was measured by igniting approximately 4.0 g of pellets in a 0.5 L closed vessel. The maximum recorded pressure values for the pelleted compositions ranged from 3.6 to 4.3 MPa. The residual pressure at room temperature (28°C) for the composition was observed to be between 0.47 and 0.53 MPa, which corresponds to a gas yield of 500-600 mL/g at standard temperature and pressure (STP). The combustion gas temperature was measured in situ in the combustion chamber, located 40 mm from the flame front, and ranged from 700 to 850 K. Typical Pressure-Time and Temperature-Time profiles of the pelleted composition of the present invention are presented in Figures 7 and 8, respectively.
[0048] Approximately 6.0 g of the proposed composition in pellet form was combusted in a 0.5 L chamber, and the exhaust combustion gases were directed to inflate a 10 L float to a residual pressure of 0.13 MPa. The inflation test on the cool gas generant pellets is demonstrated in Figure 9. This residual pressure was maintained for more than 48 hours after the test.
[0049] An embodiment of the invention is detailed in the following example.
[0050] Example 1: This example illustrates the one embodiment of the preparation of a typical cool gas generating composition. For a 100 g mixture of gas-generating composition powder, 45-55 g of anhydrous calcium azotetrazolate and 45-55 g of triaminoguanidine nitrate are dry blended using the paper folding and sieving technique to ensure homogeneity of the powder mix. The powder charge is then granulated using 1-2% of a fluoro elastomer binder. The wet granulation is carried out with a binder solution in acetone, prepared by dissolving 4-5 g of binder in 100 mL of acetone. The required quantity of binder-acetone solution is added in portions to the 100 g powder mix, and the binder solution is thoroughly mixed with the powder. The mixture is stirred until the excess acetone evaporates, transforming the composition into a dough-like form. This dough is then granulated by passing through respective sieves to obtain well-defined granules of size 425 - 710 µm. The dried granules are used to produce pellets, with an automatic rotary pelleting machine employed to form pellets of diameters 7 mm and 10 mm.
[0051] The crush strength of the pellets is measured using an Instron crush load tester and found to be between 1-2 kgf. The heat of reaction of the granular composition is determined by firing the respective compositions in an Isoperibol Bomb Calorimeter under an argon atmosphere at 2.8 MPa pressure, yielding a heat output of 650-750 cal/g. The friction sensitivity and impact sensitivity of the gas generant pellets are measured using BAM Friction Sensitivity Tester and BAM Fall Hammer Test Apparatus, respectively, showing that the gas generant pellets are insensitive to frictional load (> 360N) and impact energy is > 20J. The pressure output of the pelleted composition is measured by firing around 4.0 g of the composition in a 0.5 L closed vessel, with maximum pressure values recorded in the range of 3.6-4.3 MPa. The residual pressure at room temperature (301 K) is observed to be 0.47-0.51 MPa, corresponding to a gas yield of 500-600 mL/g at STP. The end-use of the proposed composition (Example 1) in Ø7 mm and Ø10 mm pellet forms is for the inflation of bladders and toroids. In this example, 6.0-6.1 g of gas generant pellets (CTV)is combusted in a 500 cc chamber, directing the exhaust combustion gases to inflate a 10L bladder to a residual pressure of 0.13 MPa.
[0052] Example 2: This example illustrates another embodiment of the preparation of a cool gasgenerating composition incorporating potassium perchlorate (KP) as a burn rate enhancer and initiation aid. The composition described in Example 1 is modified to include 45-55% calcium azotetrazolate (CZT), 40-45% triaminoguanidine nitrate (TaGN), 8-10% by mass of KP, and 1-2% fluoro elastomer as a binder.The heat of reaction for the granular composition is determined in an argon atmosphere at a pressure of 2.8 MPa, resulting in a heat output of 750-850 cal/g. The inclusion of KP enhances both the heat output and the ignitability of the composition. The pressure output of approximately 4.0 g of the pelleted composition is measured by firing it in a 0.5 L closed vessel, yielding maximum pressure values in the range of 3.7-4.4 MPa. The residual pressure at room temperature (301 K) is found to be between 0.49-0.55 MPa, which corresponds to a gas yield of 500-600 mL/g at standard temperature and pressure (STP).
[0053] Example 3: This example illustrates yet another embodiment of the preparation of a cool gasgenerating composition with a higher concentration of binder to enhance the crush strength of the pellets. The composition described in Example 1 is modified to include 45-55% calcium azotetrazolate (CZT), 40-45% triaminoguanidine nitrate (TaGN), 8-10% by mass of potassium perchlorate (KP), and 3-5% fluoro elastomer as a binder. The increased binder content significantly improves the crush strength of the pellets, raising it to a range of 7-15 kgf.
[0054] Example 4: This example illustrates yet another embodiment of the preparation of a cool gasgenerating composition utilizing a highly energetic binder, such as cellulose nitrate, to enhance energetics, including burn rate and calorific value. The composition described in Example 1 is modified to comprise 45-55% calcium azotetrazolate (CZT), 40-45% triaminoguanidine nitrate (TaGN), 8-10% by mass of potassium perchlorate (KP), and 1-3% cellulose nitrate as the binder, replacing the fluoro elastomer. The burn rate of the modified composition was measured at 9.88 ± 0.90 mm/s (@40 bar), while the calorific value was determined to be between 800-900 cal/g.
[0055] The invention relates to a novel cool gas-generating composition designed for applications in inflation systems, such as crew module uprighting systems and inflatable aerodynamic decelerators. This composition utilizes Calcium azotetrazolate (CZT) as a high-nitrogen fuel, Triaminoguanidine nitrate (TaGN) as a nitrogenous oxidizer, and optionally includes potassium perchlorate (KP) as a burn rate enhancer, along with a fluoro elastomer binder. The formulation achieves a high gas yield of 500-600 mL/g at standard temperature and pressure (STP), with a combustion flame temperature of 850 K or lower. Importantly, the combustion products are non-toxic and filterable, ensuring safety during use. The invention addresses the limitations of conventional gas-generating compositions by providing a solution that generates high residual pressure with low gas temperatures, making it suitable for various aerospace applications.
[0056] The present invention may take many forms and modifications, and the specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms set forth in the detailed description, but rather to include all modifications and equivalents within the spirit and scope of the invention as defined. , Claims:I / We Claim
1. A cool gas generating composition suitable for inflation systems, comprising:
Calcium azotetrazolate (CZT) as a high nitrogen fuel;
Triaminoguanidine nitrate (TaGN) as a nitrogenous oxidizer;
Potassium perchlorate (KP) as a burn rate enhancer and initiation aid as optional; and
Fluoro elastomer or cellulose derivative as a binder.
2. The composition as claimed in claim 1, wherein the composition comprises:
from 45% to 55% by mass of calcium azotetrazolate (CZT);
from 40% to 55% by mass of triaminoguanidine nitrate (TaGN);
from 8% to 10% by mass of potassium perchlorate (KP) as optional; and
from 1% to 5% by mass of fluoro elastomer or 1 to 3% of cellulose derivative.
3. The composition as claimed in claim 1, wherein the composition has the following desirable qualities (a) to (c) upon combustion:
(a) a gas yield of 500-600 mL/g at standard temperature and pressure (STP);
(b) a combustion flame temperature of 850K or lower; and
(c) a residual pressure of 0.47-0.55 MPa at room temperature.
4. The composition as claimed in claim 1, wherein the composition produces non-toxic, non-corrosive, and filterable combustion products.
5. A method of forming cool gas generant pellets by wet granulation, comprising the steps of:
uniformly mixing the gas-generating composition powders of calcium azotetrazolate (CZT) and triaminoguanidine nitrate (TaGN) according to a proportion using a paper folding and sieving technique;
adding the mixed powder composition into a binder-acetone solution according to a proportion using the solvent evaporation technique to form a dough-like consistency;
granulating the formed dough to obtain well-defined granules of the required size by passing through appropriate sieves; and
forming pellets of the required size from the dried granules using an automatic rotary pelleting machine.
6. The method as claimed in claim 5, wherein the granular size of the well-defined granules is 425 - 710 µm.
7. The method as claimed in claim 5, wherein the paper folding and sieving technique is used to attain a homogenous powder composition mix.
8. The method as claimed in claim 5, wherein potassium perchlorate (KP) is optionally added into the mixed powder composition to enhance heat output and improve ignitability of the composition.
9. The method as claimed in claim 5, wherein the average diameter of the pellets is in the range of 7-10 mm.
10. The method as claimed in claim 5, wherein the gas generant pellets are insensitive to frictional load > 360N and impact energy > 20J.

Documents