JPH10139579A - Gas producing agent composition and inflator structure using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas producing agent compsn. having large gas producing moles per a unit gas producing agent mass which can minimize the size of the gas producing container by incorporating a fuel containing a nitrogen-contg. compd., and nitrate or an oxidizing agent essentially comprising nitrate. SOLUTION: As for the nitrogen-containing org. compd. as a fuel, dinitroamerine compd. (2-oxy-4,6-dinitramine-5-triazine) prepared by nitrating melamine is used. The amt. of the dinitroamerine compd. in the fuel is controlled to 30 to 80wt.% of the whole fuel weight. As for the oxidizing agent, a single nitrate such as ammonium nitrate and potassium nitrate or a mixture of nitrate and other oxidizing agent can be used. When ammonium nitrate is used, its amt. in the fuel material is controlled to 20 to 70wt.% of the whole weight. The gas producing agent compsn. above described is used as a combustion material, while water or a polymer having a high water content is used as a coolant and added by 10 to 100% of the combusting material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generating composition for applications such as an air bag and an inflator structure using the same. The inflator according to the present invention generates a gas which does not reach a relatively high temperature, using water or a high water-containing polymer substance as a coolant.

[0002]

2. Description of the Related Art In an airbag, when a vehicle collides, a sensor detects the collision, diagnoses whether a signal from the sensor is correct, and supplies a current to an ignition device of a gas generator to ignite. The gas generating agent is burned, and the generated gas is blown into the bag to inflate it.This inflated air bag prevents the occupant from hitting the steering wheel or windshield, and generates gas including squibs, gas generating agents, filters, etc. The vessel is called an inflator. Gas generating agents for such applications should have as little as possible products, released particulates and solids released by combustion,
It is required to have an appropriate burning rate. Also,
It is desirable that the temperature of the effluent, such as the effluent gas and the emitted particulate matter, be low. In an airbag, if the temperature of the released gas is high, the bag may be damaged and the occupant may be burned.

That is, various performances are required for a gas generating agent, particularly for a gas generating composition, but the following requirements are important.
The first requirement is [having a moderate burning rate].
The second requirement is that the combustion temperature and, consequently, the emitted gas temperature be low. If the temperature of the released gas is high, a hole may be formed in the bag and the occupant may be burned. Also, the bag may burn and cause a fire. The third requirement is [that toxic concentrations of components such as CO and NO _X in the rear gas is low. If the concentration of the toxic components generated by the explosion is high, the occupants may be poisoned by the gas released into the vehicle when the bag is deflated. The fourth requirement is [impact ignitability (ignition sensitivity to impact) is low]. If the impact ignitability is high, an explosion or detonation is likely to occur in a manufacturing process such as mixing or molding, and there is a large risk of handling.

[0004] Further, the gas generating agent naturally requires a filter in order to produce a solid product, so that the weight thereof naturally increases. There was no gas generant that could reduce solid products. Also, some of the solid products are released as particulate matter. In order to suppress the formation of the solid particulate matter, Japanese Patent Application Laid-Open No. 8-231291 discloses a gas generating composition containing a fuel comprising a metal azide or an organic compound, an oxidizing agent, and an additive of ceramic whisker or fiber. Things have been suggested.

[0005] Dinitroamerin compounds have been used as adjuvants in composite solid rocket propellant compositions at the 22nd International Pyrotechnic Seminar (Int.), Colorado, USA, July 1996.
ernational Pyrotechnics Seminar)
s etc. have proposed and announced. It has been selected as an additive to provide clean combustion products to the environment. Also here, the dinitroamerin compound is used as an additive in a phase stabilized ammonium nitrate (PSNM) / terminally hydroxylated polybutadiene (PSAN / HTPB) composite solid rocket propellant composition.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a gas generating composition which has a large number of moles of gas generated per unit gas generating mass and can therefore reduce the size of a gas generator. I do. It is another object of the present invention to provide a gas generator characterized by containing a gas generating agent and a cooling agent which have a low outgassing temperature and therefore do not require coating of the bag with heat resistant rubber or the like.

[0007]

The present invention has been made as a result of intensive studies to solve the above problems, and as a result, contains a fuel containing a nitrogen-containing organic compound and a nitrate or an oxidizing agent mainly containing a nitrate. A gas generating composition having a low solid combustion product is provided. The nitrate is preferably ammonium nitrate. Further, as the nitrogen-containing organic compound, dinitroamelin is preferable. In addition, the content of dinitroamelin in the fuel is 30% based on the total fuel weight.
~ 80% by weight is preferred. Further, the content of ammonium nitrate in the combustion material is preferably from 20 to 70% by weight based on the total weight.

[0008] The above-mentioned gas generating composition is used as a burning substance, and water or a high water-containing polymer is provided as a cooling agent for the burning substance. For this purpose, a filter for a solid produced by burning is provided. Alternatively, an inflator structure for gas generation with or without gas supply could be provided. The coolant is
Water is preferred. The coolant is preferably a high water content polymer substance. Further, the water of the coolant is preferably water alone or an aqueous solution of an inorganic salt. The ratio of the coolant to the combustion substance is preferably 10 to 100%.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The gas generating composition according to the present invention comprises: It generates inflator gas for airbags for automobiles, etc., and has a fuel containing a nitrogen-containing organic compound and a combustion substance consisting of nitrate or an oxidant mainly containing nitrate, and water or a highly water-containing substance as a coolant. Low emission gas temperature, resulting in low solid combustion products. The combustion material has a very good burning rate.

[0010] Further, as the nitrogen-containing organic compound used as a fuel in the present invention, dinitroamerin can be mentioned.
Mixtures with organic compounds containing it can also be used. The dinitroamelin compound is the official name, 2-oxy-4,6-
It is called dinitramine-5-triazine (DNAM) and is a compound having the following chemical formula obtained by nitrating melamine (C ₃ H ₆ N ₆ ).

[0011]

Embedded image

Although the dinitroamelin compound has a very fast burning rate, it has been clarified that it can be used as an inflator gas generating agent by controlling it according to the present invention. Accordingly, the dinitroamerin compound is thermally stable in the gas generant composition, but plays a role in significantly increasing the burning rate of the burning substance.

In the gas generating composition of the present invention, the oxidizing agent includes nitrate alone or a mixture of nitrate and another oxidizing agent. Here, ammonium nitrate, potassium nitrate, and strontium nitrate can be used as the nitrate, and potassium nitrite and strontium nitrite can be used as the nitrite.

Other oxidizing agents include iron oxide, cobalt oxide, copper oxide, manganese dioxide, molybdenum disulfide, perchlorate and the like. Any of these or a mixture thereof can be mixed and used as an oxide.

The gas generating composition of the present invention can be used in the form of a disk, a pellet or a granule. In addition to the fuel and the oxidizing agent, a binder is used for molding and solidifying the powder of the fuel and the oxidizing agent. As the binder, commonly used cellulose acetate, soluble starch and the like are used. Further, a sintering agent for fixing the resulting solid substance as a sintered solid (slug) can be used. Examples of the sintering agent include silicon dioxide and aluminum oxide.

In the inflator structure using the above-mentioned gas generating composition of the present invention, water or a high water-containing polymer coolant is used instead of or in addition to the conventional filter. The above gas generating composition,
The combustion temperature is high and, at the same time, the burning rate is very rapid, so that the water lowers the temperature of the product,
It is intended to generate a large amount of gas. Therefore, it may be arranged anywhere in the inflator structure as long as water comes into contact with the combustion products and evaporates when the combustion material performs rapid combustion. Generally speaking,
Inflator (gas generator) as a convenient location
Outside of the gas discharge holes of the combustion chamber is possible. According to a preferred embodiment of the present invention, the coolant container is perforated with hot gas ejected from the discharge hole, and water or high water-containing polymer inside comes into contact with the hot gas and water evaporates rapidly. And lower the gas temperature.

Therefore, the coolant used in the present invention is:
Water or high water content polymeric substances can be used. These are hermetically placed in a suitable container. As a container,
Metal or plastic containers can be used.

Further, as the water as the coolant in the present invention, water alone or a solution in which an inorganic substance is dissolved can be used.

The following are used as the high water content polymer substance as the coolant of the present invention. As a material for producing a high water-containing polymer used in the gas generating composition of the present invention, a currently known high water-absorbing polymer can be used. This super-absorbent polymer absorbs water several hundred times to 1,000 times its own weight, and the hydrogel that has once absorbed water and swells has excellent water retention, which does not separate even if some pressure is applied. Things. Specific examples include superabsorbent starch and superabsorbent resin such as Sumikagel (particularly, S
-50: Sumitomo Chemical), Arasorp (Arakawa Chemical), Wonder Gel (Kao), Sunwet (Sanyo Chemical), KI Gel (Kuraray Isobrene), Lanseal (Nippon Xlan Industrial), GP (Nippon Synthetic Chemical Industry), Aquaric (Nippon Shokubai Chemical Industry) and the like. In foreign-made products, D.I. W. A. L. (Manufactured by Dow Chemical), Aqualon (manufactured by Hercule), Axel (manufactured by Enka), and the like.

Further, as the high water-containing polymer substance as a cooling agent, mannan (konjac), guar gum and the like can be used.

When the gas generant composition of the present invention is used in an inflator (gas generator) structure having a conventional structure, water or a high water-containing polymer substance as a cooling agent may be, for example, With the structure described above, it is possible to fill a part of the location where the coolant is provided. That is, the high-temperature gas generated by the rapid combustion of the gas generating composition of the present invention collides with water or a coolant of high water-containing polymer substance, evaporates water therein, and further increases the amount of generated gas. At the same time, the temperature of the generated gas can be lowered.

Next, according to the present invention, when the gas generating composition containing the combustion substance and the oxidizing agent is filled, the gas generating composition having a structure containing a high water content polymer is used. It can be configured to sandwich the hydrated polymer substance for an appropriate amount. In such an inflator structure, the combustion material of the present invention is rapidly oxidized and burned by the oxidizing agent together with the combustion material, and thereafter, the heat of combustion of the combustion material evaporates water, and the water becomes gas. Occur. Further, the combustion energy of the combustion substance of the present invention is weakened by this amount, and low-temperature gas is generated.

It is preferable that the content of the dinitroamelin compound in the fuel is 30 to 80% by weight.
That is, the content of Jinitoroamerin is less than 30 wt%, the combustion speed is insufficient, occurrence of the NO _X increases. On the other hand, if it exceeds 80% by weight, generation of CO increases. Furthermore, the content of ammonium nitrate in the combustion material is:
20-70% by weight is preferred. That is, if the amount is less than 20% by weight, the amount of provided oxygen is insufficient, and the amount of generated CO increases. If the amount exceeds 70% by weight, the combustion rate is insufficient,
The generation of NO _X increases.

The ratio of the cooling agent used in the inflator structure of the present invention to the gas generating composition is 10%.
-100% is preferred. That is, when the amount of the coolant is less than 10%, the cooling effect is small.

As described above, according to the present invention, the gas generating composition in the inflator structure is filled in the form of particles, pellets, or disks. Further, the gas generating composition is filled in an appropriate place in the inflator. When it is burned rapidly, its surroundings are exposed to high temperatures, and if water or a high-molecular-weight high-molecular-weight coolant is placed there, it can be rapidly converted to steam.

Therefore, for example, if the high water-containing polymer is provided in a part of the place where the coolant having the conventional structure is provided,
The high-temperature gas or the like generated by the combustion of the gas generating composition of the present invention hits and rapidly generates steam gas. This high water content polymer substance can be used alone, or 2
More than one species can be used in combination. High water content polymer substances
Commercial products can be used as they are.

The mixing ratio of the gas generating composition of the present invention and the high water content polymer is not particularly limited, but the mixing ratio of the gas generating composition and the ratio of the combustion material, the oxidizing agent and the high water content polymer are not limited. , Can be appropriately selected from a wide range.

The gas generant composition of the present invention is also filled into a suitably shaped prior art inflator structure.
In the gas generating composition of the present invention, an appropriate amount of a binder is mixed and filled.

The high water-containing polymer substance provided in the inflator structure can be used, for example, as it is or by impregnating a net-like structure or a porous body and putting it in a metal or plastic container. The shape of the combustion substance is not particularly limited, and may be, for example, a disk, a pellet, a particle, a column, a cone, a polygonal pyramid, or a polygonal column.

The gas generating composition of the present invention can be filled in a metal canister (inner vessel) and loaded in an inflator vessel.

Next, the gas generant composition of the present invention and the cooling agent in the inflator structure will be specifically described with reference to examples, but the present invention is not limited thereto. Hereinafter, examples, comparative examples, and test examples will be described.

[0032]

Example 1 DNAM (2-oxy-4,6-dinitroaluminum) was used as a fuel with the gas generating composition shown in Table 1.
Compositions 1, 2 and 3 using -5-triazine: dinitroamerin) and Comparative Examples 4 and 5 using TAGN (triaminoguanidine nitrate) or urazole as fuel.
Compositions 6 and 7 were prepared, and the burning rate, burning temperature, and the molar ratio of solid product and gas produced / 100 g were measured. Table 1 shows the results.

[0033]

[Table 1]

Examples Compositions 1, 2, 3 and Comparative Examples 4, 5,
From the data obtained in 6, 7 the composition using DNAM as a fuel has a higher burning rate and a larger amount of gas generation per unit mass of the composition than the composition using TAGN or urazole as a fuel. It can be seen that the production amount of the solid product per unit mass of the product is equal or less. On the other hand, the burning temperature of the composition using DNAM as fuel is
It is higher than the combustion temperature of a composition using TAGN or urazole. However, it is clear that this problem has been solved by the gas generating agent of the present invention using water or a high water-containing polymer substance as a coolant.

[0035]

Example 2 Table 2 shows the combustion temperatures when 10% to 60% by weight of water was used as a coolant for Example compositions 1, 2 and 3 shown in Example 1. .

[0036]

[Table 2]

From the data shown in Table 2, it can be seen that the combustion temperature could be reduced by using water as the coolant.

[0038]

Example 3 The gas generating composition 1 shown in Example 1 was used
Formed into pellets of 6mm in diameter and 4mm in thickness, 15g of which
As a gas generating agent 4 in a model inflator shown in FIG. That is, the gas generant composition 1 (4) of the present invention is placed in an inflator structure provided with an ignition leg 1, a squib 2, and an enhancer 3. On the outside, a partition provided with a nozzle 7 is provided, and a coolant 8 and a filter 9 are provided outside.

Further, the same gas generating composition 1 was loaded into a tester of a 60 L tank 21 shown in FIG. 2, and an operation experiment was performed. That is, the model inflator 22 shown in FIG.
Is mounted in a 60 L tank 21 and an electric current is applied to an ignition leg 25 to explode the gas generating composition 4 of the present invention in the inflator 22. At this time, the pressure in the tank 21 is measured by a pressure sensor 24. And the tank temperature and tank pressure due to the explosive gas were measured with a thermocouple 27 and a pressure sensor. The generated gas sample and the like were measured. Table 3 shows the results. As a coolant, a coolant 8 impregnated with 10 g of water mixed with 0.1 g of Sumika gel was used. No filter was used.

[0040]

[Table 3]

[0041]

Example 4 In order to measure the effect as a coolant, the following experiment was conducted. The gas generating agent used was ADC
A (azodicarbonamide) 47.0%, KClO ₄ 4.7
A composition consisting of 0%, 8.5% KNO ₃ , 1.7% CoMnO _4, 1.7% soluble starch and 0.85% SiO ₂ was formed into pellets having a diameter of 6 mm and a thickness of 4 mm, and weighing 25 g. is there.
The experimental apparatus used a model inflator as shown in FIG. 1 and a 60 L tank tester as shown in FIG. Table 4 shows the obtained results. The coolant net is a 25 g stainless steel net.

The filter used was 110 g, which was a combination of a stainless steel mesh and a ceramics filter.

[0043]

[Table 4]

From the above results, it can be seen that when the coolant according to the present invention was used, the tank temperature was significantly lowered depending on the amount used.

[0045]

The gas generating composition of the present invention has the following technical effects. First, the present invention provides an efficient and compact generator that can generate a large amount of gas, has a sufficiently high burning rate, and has a low explosive gas temperature. Secondly, an inflator structure using water or a high water-containing polymer as a coolant, which can increase the gas generation rate and at the same time lower the generated gas temperature, is obtained by the composition comprising the fuel and the specific oxidizing agent.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an inflator structure filled with a gas generating composition of the present invention.

FIG. 2 is a sectional view of an apparatus for testing the gas generating composition of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ignition leg 2 Squib 3 Enhancer 4 Gas generating composition of the present invention 5 Aluminum cup 6 Inner shell 7 Nozzle 8 Coolant: Coolant 9 Filter 10 Outer shell 11 Day fuser 12 Pressure sensor 21 60L tank 22 Model Inflator 23 Model inflator base 24 Combustion chamber pressure sensor 25 Ignition leg 26 Tank pressure sensor 27 Thermocouple for tank temperature 28 Pressure release valve 29 Gas sampling valve

Claims (10)

[Claims] 1. A fuel containing a nitrogen-containing organic compound,
A gas generating composition containing less solid combustion products, comprising a nitrate or an oxidizing agent mainly composed of a nitrate. 2. The gas generating composition according to claim 1, wherein the nitrate is ammonium nitrate. 3. The gas generating composition according to claim 1, wherein the nitrogen-containing organic compound is dinitroamerin. 4. The gas generant composition according to claim 3, wherein the content of dinitroamelin in the fuel is 30 to 80% by weight based on the total weight of the fuel. 5. The gas generation according to claim 1, wherein the content of ammonium nitrate in the combustion material is 20 to 70% by weight based on the total weight. Composition. 6. A gas-generating agent composition according to any one of claims 1 to 5 as a combustion substance, and water or a high water-containing polymer is provided as a cooling agent with respect to the combustion substance and produced by combustion. An inflator structure for gas generation, with or without a filter for solids. 7. The inflator structure according to claim 6, wherein the coolant is water. 8. The inflator structure according to claim 6, wherein the coolant is a high water-containing polymer substance. 9. The inflator structure according to claim 7, wherein the water of the coolant is water alone or an aqueous solution of an inorganic salt. 10. The ratio of coolant to combustion material is:
The inflator structure according to any one of claims 6 to 9, wherein the content is 10 to 100%.