JP2000273090A - Guanylaminotetrazole and gas-generating agent for automotive safety device using the same as basis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain guanylaminotetrazole sparingly containing impurities and to prepare a gas-generating agent having the high decomposition temperature and excellent heat stability by employing the compound as a gas-generating basis. SOLUTION: A guanylaminotetrazole is obtained by removing impurities having the low decomposition-starting temperature from the crude product produced by reacting cyanamide with 5-aminotetrazole. This gas-generating agent for automotive safety device contains the guanylaminotetrazole as a basis, contains the guanylaminotetrazole and an oxidant as effective ingredients or may contain the guanylaminotetrazole, an oxidant, and a cooling and residue- forming agent as effective ingredients. The oxidant is at least one kind selected from the group consisting of an oxohalogen acid salt and a nitrate. The cooling and residue-forming agent contains at least one kind selected from the group consisting of a metal oxide, a carbonate and a sulfate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to guanylaminotetrazole and a gas generating agent for operating an automobile safety device using the guanylaminotetrazole.

[0002]

2. Description of the Related Art As a gas generating agent for generating a gas for operating an automobile safety device, for example, a gas generating agent used for a gas generator for an air bag, a gas generator for a seat belt pretensioner, and the like are available. . The most commonly used gas generating agents for automobile safety devices are those containing a metal azide compound such as sodium azide as a main component. However, the gas generating agent of a metal azide compound has drawbacks such as high impact ignitability, necessity of handling in a manufacturing operation, and the need for a special treatment facility for working wastewater.

[0003] In recent years, the importance of preserving the environment and safety has been demanded. Therefore, there has been a strong demand for the development of a non-azide-based gas generating agent which does not use a metal azide compound. I have. As a non-azide gas generating agent, Japanese Patent Application Laid-Open No. 10-1 discloses a gas generating agent based on 5-aminotetrazole and containing an oxidizing agent and the like.
It is disclosed in Japanese Patent Publication No. 30086 and Japanese Patent Publication No. Hei 10-501516.

[0004]

However, these 5-aminotetrazole-based gas generating agents have a relatively low decomposition onset temperature of about 200 ° C., and have a problem in terms of thermal stability. As described above, the problem of thermal stability that the decomposition temperature is low is that, for example, when a gas generating agent is housed in a container and used for a long period of time, such as an inflator for an automobile, a problem occurs in the durability of the gas generating agent, and Lack of above reliability.

Therefore, there has been a demand for a gas generating base having a high decomposition starting temperature and good thermal stability. Therefore, when searching for a base having a high decomposition start temperature with tetrazoles,
A decomposition temperature of 300 ° C. was described in “AD595292”, which discloses a method for producing guanylaminotetrazole.

In "AD595292", 5-aminotetrazole is added to a cyanamide solution whose pH has been adjusted with aqueous ammonia to cause guanylaminotetrazole to react. However, the decomposition onset temperature of guanylaminotetrazole obtained by this production method is about 200 ° C., which is lower than the literature value, and HAT (1H-5-Aminotet) is used.
razole), 1HT (1H-Tetrazole)
It is expected that compounds having a low isocratic onset temperature will be contained as impurities.

Here, the findings of HAT and 1HT are described below. HAT (1H-5-Aminotetrazo)
le) Name: 5-aminotetrazole Melting point: 203 ° C (decomposition point: 203 ° C) Other: soluble in water and alcohol. LD50 = 2500m
g (mouse). It is used as a gas generating agent, an intermediate for pharmaceuticals, and the like.

1HT (1H-Tetrazole) Name: 1-hydroxytetrazol Melting point: 156 ° C. (decomposition point: 220 ° C.) Others: soluble in water, alcohol, acetone, MIBK.
Used as an intermediate for pharmaceuticals.

Accordingly, an object of the present invention is to obtain guanylaminotetrazole having a small amount of impurities, and to obtain a gas generating agent which uses this guanylaminotetrazole as a gas generating base and has good thermal stability at a high decomposition temperature. It is in.

[0010]

The present invention is characterized in that the crude product produced by the reaction between cyanamide and 5-aminotetrazole is free from impurities having a low decomposition initiation temperature.

According to a second aspect of the present invention, in the guanylaminotetrazole according to the first aspect, the impurities are removed by acetone. A third aspect is characterized in that the guanylaminotetrazole according to the first aspect is used as a base. According to a fourth aspect, the guanylaminotetrazole according to the first aspect and an oxidizing agent are used as active ingredients.

According to a fifth aspect of the present invention, in the gas generating agent for an automobile safety device according to the fourth aspect, the oxidizing agent is at least one component selected from oxohalogenates and nitrates. Claim 6 is the gas generating agent for an automobile safety device according to claim 5, wherein the nitrate is
It is a phase-stabilized ammonium nitrate.

A seventh aspect of the present invention is characterized in that the gas generating agent for a vehicle safety device according to the fourth aspect and a coolant / residue forming agent are effective components. According to an eighth aspect of the present invention, in the gas generating agent for an automobile safety device according to the seventh aspect, the coolant / residue forming agent includes at least one selected from metal oxides, carbonates, and sulfates. I do.

A ninth aspect of the present invention is the gas generating agent for an automobile safety device according to the eighth aspect, wherein the metal oxide is kaolin. According to a tenth aspect, in the gas generating agent for an automobile safety device according to the eighth aspect, the carbonate is a carbonate of an alkaline earth metal. An eleventh aspect of the present invention is the gas generating agent for an automobile safety device according to the tenth aspect, wherein the alkaline earth metal carbonate is magnesium carbonate.

According to a twelfth aspect of the present invention, in the gas generating agent for an automobile safety device according to the eighth aspect, the sulfate is a sulfate of an alkaline earth metal. Claim 13
The gas generating agent for a vehicle safety device according to claim 12, wherein the sulfate of the alkaline earth metal is magnesium sulfate.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The high-purity guanylaminotetrazole of the present invention, which is low in impurities, ie, high-purity, is produced from 5-aminotetrazole as a raw material as follows.

First, 5-aminotetrazole is reacted with cyanamide. This reaction is carried out in a cyanamide solution neutralized with ammonium hydroxide, usually at a temperature of 60 to 100 ° C, preferably at a temperature of 70 to 90 ° C under normal pressure. At this time, the cyanamide is used usually in an amount of 0.5 to 10 times, preferably 1 to 3 times, mol of 5-aminotetrazole.
Used twice as much.

Acetone is added to the crude product guanylaminotetrazole produced by this reaction to dissolve and extract impurities in the crude product, and further filtered and separated (separation of guanylaminotetrazole and the reaction mother liquor is performed). ) To obtain the desired guanylaminotetrazole (corresponding to claims 1 and 2). Here, the knowledge of the reaction mother liquor will be described.

The solid remaining undissolved in the saturated solution of the solid is called a liquid bottom, and the saturated solution is called a mother liquor (in this case, acetone). Next, less impurities of the present invention,
That is, an embodiment of a gas generating agent for a vehicle safety device based on high-purity guanylaminotetrazole will be described (corresponding to claims 3 to 13).

A gas generating agent which uses high-purity guanylaminotetrazole as a gas generating base and also contains an inorganic oxidizing agent and the like as an active ingredient. As the inorganic oxidizing agent, a known inorganic oxidizing agent contained in a conventional gas generating agent for an air bag or a gas generating agent for a seat belt pretensioner can be used. As the inorganic oxidizing agent, at least one or more oxidizing agents selected from oxohalogenates, nitrates and the like are used.

For example, the oxohalogenates include alkali metal perchlorates such as potassium perchlorate and sodium perchlorate; alkali metal chlorates such as potassium chlorate and sodium chlorate; And ammonium chlorate. As nitrates, potassium nitrate,
Examples include alkali metal nitrates such as sodium nitrate, alkaline earth metal nitrates such as strontium nitrate, and ammonium nitrate.

Further, ammonium nitrate phase-stabilized by a potassium compound and the like can also be mentioned. As a method for stabilizing the phase, a known method, for example, Japanese Patent Application Laid-Open No. H10-25
As disclosed in Japanese Patent Publication No. 9085, it is possible by a method of adding an inorganic potassium salt or a potassium salt of an organic compound. Among these oxidizing agents, nitrates are preferable, and alkaline earth metal salts are more preferable.

Examples of the coolant / residue forming agent include kaolin as a metal oxide, magnesium carbonate as a carbonate, magnesium sulfate as a sulfate, and the like. This kaolin (ka
olin) is described in the Chemical Dictionary (Kyoritsu Shuppan).

"Kaolin (white clay)" A kaolin family mineral in clay minerals. It is generated by weathering of granite and tuff, or hydrothermal action of quartz trachyte and quartz gamite, and alteration by hot spring action. The basic chemical formula is Al ₂ Si ₂ O ₅ (OH) ₄ ,
Typical analysis value ranges are: SiO ₂ : 42 to 46, Al ₂ O
_{3: 37~40, Fe 2 O 3} : 0.5~0.9, TiO 2:
0-1, CaO: 0-0.7, MgO: 0-0.3, K
_{2 O: 0~0.5, Na 2 O} : 0 to 0.6%.

The above-mentioned analytical value range is an analytical value measured when a substance called kaolin is analyzed, and this numerical value can be regarded as a range including variations between substances and analytical errors. This kaolin is used as a raw material for ceramics because it has plasticity when kneaded with water and exhibits appropriate strength when dried, but has lower plasticity than ordinary clay.

When the above-mentioned kaolin is blended with the gas generating composition of the present embodiment, the combustion temperature is lowered and, at the same time, a residue is formed by itself, so that the solid content in the components of the gas generating composition is taken in. be able to. It was also found that the use of magnesium carbonate and magnesium sulfate had the same effect as kaolin. This is because the combustion temperature of the gas generating composition can decrease, but indirectly, can serve as a residue forming agent.

Next, the cooling effect of magnesium carbonate, magnesium sulfate and kaolin will be described. Kaolin is
It is a chemically stable substance and does not decompose easily. However, when it is incorporated into an explosive component such as a gas generating agent, it is considered that it is exposed to a very high combustion temperature and kaolin itself melts. It is considered that the heat of fusion at the time of melting indicates endotherm, and furthermore, generation of water from OH causes combustion inhibition (cooling effect).

Magnesium carbonate and magnesium sulfate are different from the inhibition of kaolin combustion, and are due to thermal decomposition. Taking magnesium carbonate as an example, it decomposes into magnesium oxide and carbon monoxide. The reaction at this time is an endothermic reaction (endothermic decomposition), which has the effect of slightly reducing the calorific value during combustion of the gas generating composition. It is.

The same effect is obtained with magnesium sulfate.

[0030]

EXAMPLES (Example 1) Dilute ammonium hydroxide and pH =
1 mol (42 g) of the cyanamide solution 300 prepared in Example 7
1 ml (85 g) of 5-aminotetrazole was added to the ml.

Next, after stirring for 5 hours while heating, the solid matter was separated by filtration while hot. Next, 100 ml of acetone was added to this solid to suspend it, and then the solid was filtered off again by filtration. Wash this with a small amount of acetone,
Dry in vacuo to give a white solid. Weight loss onset temperature (TG): 300 ° C. (primary decomposition onset temperature) Primary weight loss rate (TG): 46% (Comparative Example 1) 1 mol (42 g) of cyanamide prepared to pH = 7 with dilute ammonium hydroxide 5 in 300 ml of solution
1 mol (85 g) of aminotetrazole was added.

Next, after stirring for 5 hours while heating, the solid matter was separated by filtration while hot. This was vacuum dried to give a white solid. Primary weight loss starting temperature (TG): 195 ° C (temperature at which decomposition of guanylaminotetrazole (GAT) containing impurities starts) Primary weight loss rate (TG): 21% Secondary weight loss starting temperature (TG): 310 ° C (guanylamino) Decomposition start temperature of tetrazole (GAT) Secondary weight loss (TG): 23% Example 1 (see FIG. 1) and Comparative Example 1 (see FIG. 2)
Is to increase the temperature from room temperature to 600 ° C. in steps of 10 ° C. per minute, and to determine the temperature at which the weight is reduced. Comparative Example 1 was attempted from the prior literature (AD595292).

Here, TG, DT in FIGS.
G and DTA will be described. TG: Weight change when temperature is applied, and represents the temperature at which weight loss starts in Examples and Comparative Examples. DTG: The change in weight loss for one minute is faster as the peak of the protrusion is sharper and higher. DTA: Change in whether heat is generated or heat is absorbed (when the protrusion extends downward, heat is absorbed, and when the protrusion extends upward, heat is generated).

[Discussion] First, Example 1 is stable up to 300 ° C., has a slight decrease in thermogravity, and heat absorption occurs near this. In addition, guanylaminotetrazole (GAT) having a higher decomposition initiation temperature (higher thermal stability) than 5-aminotetrazole (HAT) can be obtained.

From this, this guanylaminotetrazole (GAT) has high purity and good thermal stability. When used as a gas generating agent for an air bag, it has good thermal stability and can be maintained for a long period of time. It can be seen that a highly reliable product can be obtained. Next, in Comparative Example 1, according to the prior art (AD595292), there should be no primary thermogravimetric change up to 300 ° C., but in practice, the thermogravimetric change is reduced at 195 ° C. It is happening around this temperature.

From this, it is presumed that this guanylaminotetrazole (GAT) contains impurities and has poor thermal stability. When this guanylaminotetrazole (GAT) is used as a gas generating agent for an airbag, it has poor thermal stability and lacks reliability for long-term maintenance.

Example 2 29.9 parts by weight of the guanylaminotetrazole obtained in Example 1, 68.1 parts by weight of strontium nitrate, and 2 parts by weight of fluororubber were blended to produce a wet powder. The wet powder was granulated by a granulator, and the obtained wet granules were dried to produce a gas generating agent.

(Example 3) 26.8 parts by weight of the guanylaminotetrazole obtained in Example 1, 61.2 parts by weight of strontium nitrate, 10 parts by weight of kaolin, and 2 parts by weight of fluororubber were blended to obtain a wet powder. Body manufactured.

This wet powder was granulated by a granulator, and the obtained wet granules were dried to produce a gas generating agent. (Example 4) 27.6 parts by weight of the guanylaminotetrazole obtained in Example 1, 61.4 parts by weight of strontium nitrate, 10 parts by weight of kaolin, and 1 part by weight of fluororubber were blended to produce a wet powder. did.

The wet powder was granulated by a granulator, and the obtained wet granules were dried to produce a gas generating agent. (Example 5) 28.4 parts by weight of the guanylaminotetrazole obtained in Example 1, 61.6 parts by weight of strontium nitrate, and 10 parts by weight of kaolin were blended to produce a wet powder.

This wet powder was granulated by a granulator, and the obtained wet granules were dried to produce a gas generating agent. (Example 6) 28.3 parts by weight of the guanylaminotetrazole obtained in Example 1, 64.7 parts by weight of strontium nitrate, 5 parts by weight of kaolin, and 2 parts by weight of fluororubber were blended to produce a wet powder. did.

This wet powder was granulated by a granulator, and the obtained wet granules were dried to produce a gas generating agent. (Example 7) 29.9 parts by weight of the guanylaminotetrazole obtained in Example 1, 65.1 parts by weight of strontium nitrate, and 5 parts by weight of kaolin were blended to produce a wet powder.

This wet powder was granulated by a granulator, and the obtained wet granules were dried to produce a gas generating agent. (Example 8) 34.9 parts by weight of the guanylaminotetrazole obtained in Example 1, 63.6 parts by weight of potassium perchlorate, and 1.5 parts by weight of fluororubber were blended to produce a wet powder. .

The wet powder was granulated by a granulator, and the obtained wet granules were dried to produce a gas generating agent. Comparative Example 2 13.9 parts by weight of 5-aminotetrazole, 85.1 parts by weight of phase-stabilized ammonium nitrate, and 1 part by weight of fluororubber were blended to produce a wet powder.

This wet powder was granulated, and the obtained wet granules were dried to produce a gas generating agent. Comparative Example 3 10.0 parts by weight of 5-aminotetrazole, 88.0 parts by weight of phase-stabilized ammonium nitrate and 2 parts by weight of cellulose were mixed to produce a wet powder.

This wet powder was granulated, and the obtained wet granules were dried to produce a gas generating agent. (Test Example 1) As shown in FIG. 3, a combustion chamber (test container) of an inflator 10 having a gas ejection hole 7 having a diameter of 3.0 mm.
6, an ignition charge container 5 loaded with 1.5 g of potassium potassium nitrate as a transfer agent was arranged, and the gas generant 4 obtained in Example 2 was pressed by a cam-type tableting machine to produce gas generant pellets. 30 g (diameter 6 mm, height 3 mm) was filled.

The gas outlet 7 has a plate pressure of 0.15 mm.
The aluminum tape 3 was attached, and the lid 2 was attached to hold the pressure. The inflator 10 was placed in a closed container having a capacity of 60 liters, and the igniter 1 was energized and operated to measure the maximum pressure [KPa] in the closed container and its arrival time [ms].

The results are shown in Table 1.

[Table 1] "Discussion 1" From Test Example 1, it was found that the gas generating agent for an airbag had a sufficient pressure and a maximum pressure reaching time.

(Test Example 2) The gas generating agent produced by pressing each of the gas generating agents obtained in Example 2 and Example 3 into a combustion chamber of an inflator similar to Test Example 1 with a cam-type tableting machine. Example 2 (diameter 6 mm, height 3 mm) was 4
6.8 g, Example 3 (diameter 4 mm, height 1.5 mm)
Each 1 g was filled.

The inflator was operated under the same conditions as in Test Example 1, the amount of combustion residue remaining in the inflator was measured, and the residual ratio to the theoretically generated residue was calculated. Table 2 shows the results of Test Example 2.

[Table 2] "Discussion 2" From Test Example 2, it was found that in Example 3 including kaolin, combustion residues remained in the inflator, and the effect of residue formation was obtained.

(Test Example 3) The granules obtained in Example 2 and Comparative Example 2 were pressed with a molding machine to produce strand pellets (length 30 mm). The linear burning rate when this strand pellet was burned in an airtight container having a capacity of 1 liter under an arbitrary pressure with an inert gas was measured, and a pressure index and a coefficient were obtained. Table 3 shows the results.

[Table 3] Here, the burning rate coefficient refers to a linear burning rate in a non-pressurized combustion system, and a high burning rate coefficient means that a high burning rate can be obtained in a low-pressure combustion system. Therefore, in the gas generant composition, it is easy to obtain an arbitrary decomposition rate, which leads to a wider design of the gas generator.

The pressure index is an index of a change in the combustion speed with respect to a pressure change in the combustion system. In general, the burning rate depends on the temperature and pressure, and the higher they are, the higher they are. Therefore, a low pressure index of the gas generating composition means that a stable combustion rate can be obtained with respect to pressure fluctuations in the combustion system. [Discussion 3] From Test Example 3, the gas generating agent of the present invention has a higher decomposition rate than the composition using 5-aminotetrazole,
It was also found that the pressure (temperature) dependence was low.

(Test Example 4) The temperature at which the gas generating composition obtained in Example 2 and Comparative Example 3 started to lose (decompose) was determined. As a device, TG / DTA320 manufactured by SEIKO INSTRUMENTS was used, and 2 mg of the sample was measured at a heating rate of 10 ° C./min from room temperature to 600 ° C. Table 4 shows the results.

[Table 4] Here, the weight-reduction starting temperature is a temperature at which the mass rapidly decreases in an environment of a gradual rise in temperature, and a nonvolatile substance (or a composition containing no volatile component) corresponds to the decomposition starting temperature. . Therefore, a high weight loss start temperature means that the durability to a high temperature environment is good, and thus leads to prevention of performance deterioration of the gas generating agent.

[Discussion 4] From Test Example 4, it was found that the gas generating agent of the present invention had a higher decomposition onset temperature, that is, better thermal stability than the composition using 5-aminotetrazole. (Test Example 5) The gas generating agents obtained in Examples 2 to 7 were pressed by a cam-type tableting machine to produce gas generating agent pellets (diameter 4 mm, height 1.5 mm). The pellet strength was measured. Further, the gas generating agent pellets were filled in a combustion chamber of an inflator similar to that of Test Example 1,
Under the same conditions as above, the amount of combustion residue remaining in the inflator was measured, and the residual ratio to the theoretically generated residue amount was calculated. Table 5 shows the results of Test Example 5.

[Table 5] [Discussion 5] It was found that the effect of residue formation was enhanced by containing no kaolin in the composition when kaolin was contained in the composition, because there were many combustion residues in the inflator of Examples 5 and 7.

Embodiments 2, 5, and 7
From the pellet strength, it was found that the pellet strength was reduced by simultaneously containing the inorganic binder and the organic binder in the composition. (Test Example 6) In a combustion chamber 21 of a gas generator 20 shown in FIG. 4, 0.5 g of potassium potassium nitrate as a transfer agent 22 and a single base propellant of 0.5 as an auto ignition were used.
1 g was charged, and 0.8 g of gas generating agent pellets (diameter 3 mm, height 3 mm) 23 produced by pressing the gas generating agent obtained in Example 8 with a cam-type tableting machine was filled.

The gas generator 20 is equipped with an electric igniter 24 having a lead pin 25 for electrical connection. This gas generator 20 is installed in a closed vessel 30 having a capacity of 10 cc of the tank pressure tester shown in FIG. 5 and is operated by supplying electricity to the electric igniter 24 to operate the maximum pressure [MPa] in the closed vessel 30 and its maximum pressure [MPa]. Arrival time [m
s] was measured.

FIG. 5 shows an outline of the tank pressure test apparatus.
The pressure sensor 31 is attached to the closed container 30. The pressure sensor 31 is connected to a measuring instrument (analyzing recorder) 32, the gas generator 20 is connected to an ignition power supply 33, and the measuring instrument 32 is connected to the ignition power supply 33. Ignition power 3
When a voltage is applied from 3, the gas generator 20 is ignited, and the pressure in the closed container 30 having a volume of 10 cc increases.
At this time, the measuring device 32 senses the voltage from the ignition power supply 33 and starts measuring the pressure in the closed container 30 having a volume of 10 cc.

The measured data is represented as a time-pressure curve. Table 6 shows the results of Test Example 1.

[Table 6] "Consideration 6" From Test Example 6, it was found that the gas generator had a sufficient pressure and a maximum pressure reaching time as a gas generator for a gas generator.

[0059]

As described above, according to the first and second aspects of the present invention, guanylaminotetrazole having less impurities can be synthesized.

According to the third to thirteenth aspects of the present invention, the guanylaminotetrazole having a small amount of impurities according to the first and second aspects of the present invention is used as a gas generating base, so that gas generating for a vehicle safety device having high thermal stability is achieved. Agent can be obtained. Also, when a mixture of a coolant and a residue forming agent is used in this gas generating agent, the combustion temperature of the combustion gas is reduced, and
A combustion residue can be formed and taken into the combustion vessel.

[Brief description of the drawings]

FIG. 1 is a graph showing characteristics of guanylaminotetrazole of Example 1.

FIG. 2 is a graph showing characteristics of guanylaminotetrazole of Comparative Example 1.

FIG. 3 is a longitudinal sectional view of an inflator used for a combustion test.

FIG. 4 is a sectional view of a gas generator.

FIG. 5 is a schematic explanatory view of a tank pressure test device of Test Example 6.

Claims (13)

[Claims] 1. A guanylaminotetrazole, which is obtained by removing impurities having a low decomposition initiation temperature in a crude product produced by the reaction of cyanamide and 5-aminotetrazole. 2. The guanylaminotetrazole according to claim 1, wherein the impurities are removed by acetone. 3. A gas generating agent for a vehicle safety device, comprising the guanylaminotetrazole according to claim 1 as a base. 4. The gas generating agent for a vehicle safety device according to claim 3, wherein the guanylaminotetrazole and an oxidizing agent are used as active ingredients. 5. The gas generating agent according to claim 4, wherein the oxidizing agent is at least one component selected from oxohalogenates and nitrates. 6. The gas generating agent according to claim 5, wherein the nitrate is phase-stabilized ammonium nitrate. 7. A gas generating agent for an automobile safety device comprising the gas generating agent for an automobile safety device according to claim 4 and a coolant / residue forming agent as active ingredients. 8. The gas generating agent according to claim 7, wherein the coolant / residue forming agent contains at least one selected from metal oxides, carbonates, and sulfates. 9. The gas generating agent according to claim 7, wherein the metal oxide is kaolin. 10. The gas generating agent according to claim 7, wherein the carbonate is a carbonate of an alkaline earth metal. 11. The gas generating agent according to claim 10, wherein the alkaline earth metal carbonate is magnesium carbonate. 12. The gas generating agent according to claim 7, wherein the sulfate is a sulfate of an alkaline earth metal. 13. The gas generating agent according to claim 12, wherein the alkaline earth metal sulfate is magnesium sulfate.