JPH08301683A - Gas generating agent for air bag - Google Patents

Abstract

PURPOSE: To realize making generated gas innoxious, prevention of burning of air bag material, rapid development of air bag and long-term life of a gas generator by using an aqueous solution of hydrogen peroxide having a specific content and melting point as a gas generating main agent. CONSTITUTION: This gas generator is constituted by providing a container 80 for housing a main agent 81 which is an aqueous solution of hydrogen peroxide having <=64.5wt.% content and <=127 deg.C melting point, a decomposed catalyst container 60 housing a decomposition catalyst 63 of hydrogen peroxide such as a permanganate of an alkali metal, an ignition tool 64 attached to the interior of the decomposition catalyst container 60, a main agent container 80 in this order and a generator body 10 housing the ignition tool 64, the decomposition catalyst container 60 and the main agent container 80 and a gas jetting part 34 above the main agent container 80.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to gas generation for use in an airbag for protecting a human body from harm when a passenger, a truck, a motorcycle, or other vehicle passengers unfortunately encounters a collision accident or a self-damage accident. More specifically, it is a gas generator for an airbag using hydrogen peroxide.

[0002]

2. Description of the Related Art In recent years, the number of vehicles traveling on a road has been increasing on a global scale, and in spite of efforts by various parties concerned, the number of traffic accidents does not easily decrease. Is. For this reason, the mounting of airbags is becoming popular in order to avoid a fatal injury to passengers when a strong shock is applied to a human body unfortunately due to a collision or self-damage.

The gas generating source is a solid gas generator accommodating a solid gas generator housed in a module, which is prepared by mixing sodium azide powder with powdery perchlorate, metal oxide, metal sulfide, etc. When it detects a strong shock, it immediately ignites and plays a role in deploying the airbag rapidly. At present, compounds of this system are the mainstream of gas generating agents, and it is said that the nitrogen gas produced therefrom has physical properties suitable as a gas for airbags.

[0004]

However, sodium azide formulations also have some drawbacks. First, it has the effect of lowering the blood pressure of the operator, and there are strong regulations on the environmental protection of the workplace in mass production factories, and a large amount of expense is required for processing when a vehicle is scrapped. A small amount of sodium oxide when burning,
Thorium peroxide may be a by-product and may damage the eyes and respiratory system. The compounds react with water and ignite.

Further, there is not enough research and information on the ignition and flammability of sodium azide, which is a serious problem.
Complete measures against the risk of ignition in the production of sodium azide, the mixing of its blends, and the molding process have been delayed. Sodium azide is said to generate hydrogen azide (HN ₃ ) which is highly toxic and has high explosion sensitivity when contacted with water or acid.

A tetrazole compound is expected as a gas generating agent in place of sodium azide, but this also does not completely eliminate the danger in production, and the combustion gas contains a cyanide gas although it is a very small amount. included. Other alternative substances also have drawbacks such as generation of a large amount of carbon monoxide. On the other hand, JP-A-56-88804 discloses a gas generator using an aqueous hydrogen peroxide solution.

This solves the above-mentioned drawbacks of the sodium azide compound used as a gas generating agent for airbags. Since the airbag is mounted on the vehicle, it is essential that the airbag have the same performance even in a severe environment where the vehicle is placed. That is, it is necessary to guarantee the performance in the range of -30 ° C on the low temperature side and + 80 ° C on the high temperature side.

On the other hand, hydrogen peroxide used as a gas generating agent changes its physical properties depending on its concentration, and changes in boiling point and pseudo-fixing point. Therefore, JP-A-56-8880
Content rate of aqueous hydrogen peroxide solution disclosed in Japanese Patent Publication No. 4-5
If the content is from 30% by weight to 30% by weight, the problem of freezing in a low temperature environment occurs, and the gas generating ability at low temperatures is lost.

The gas generator for an air bag has the purpose of inflating the air bag. This airbag needs to be fully deployed within about 30 to 40 msec after the collision. For this purpose, the gas generating agent using the hydrogen peroxide solution needs to complete the decomposition reaction in 30 to 40 msec. In contrast, hydrogen peroxide has the property that the decomposition rate changes depending on its concentration. The concentration of hydrogen peroxide is a parameter of the decomposition reaction, and the higher the concentration, the faster the decomposition rate. From this, Japanese Patent Laid-Open No. 56-88
Hydrogen peroxide content disclosed in Japanese Patent No. 804 5% by weight
With 30% by weight, it is impossible to complete the decomposition reaction in 30 to 40 msec.

Therefore, the invention disclosed in Japanese Patent Laid-Open No. 56-88804 only describes that an expansion rate of 80% can be obtained within 30 seconds. It cannot be used as a gas generator at all. That is, in order to deploy an airbag for an automobile to protect an occupant, the decomposition reaction is completed within at least 50 msec to generate gas, and the airbag is
This is because it has to be expanded by 00%.

The present invention has been made to solve the above-mentioned conventional problems, and an airbag capable of alleviating the disadvantages of a sodium azide compound used as a gas generating agent for an airbag. The purpose is to provide a gas generator for use.

[0012]

The invention according to claim 1 is an aqueous solution having a hydrogen peroxide content of 64.5% by weight or less and containing a main agent having a melting point of 127 ° C. or less, A decomposition catalyst container containing a decomposition catalyst of hydrogen peroxide,
An ignition device mounted in the decomposition catalyst container, an outer cylinder, and a gas generator main body that accommodates the ignition device, the decomposition catalyst container, and the main agent container in this order and has a gas ejection portion above the main agent container. It is characterized by being.

The invention of claim 2 is characterized in that, in claim 1, the main agent is an aqueous solution having a hydrogen peroxide content of 35% by weight to 64.5% by weight. The invention of claim 3 is characterized in that, in claim 1, the main agent is an aqueous solution having a hydrogen peroxide content of 40% by weight to 60% by weight. According to the invention of claim 4, in the decomposition catalyst of hydrogen peroxide according to claim 1, a permanganate of an alkali metal or an alkaline earth metal, an alkali metal or a chromate composed of gold, platinum, silver or copper, or a lanthanoid. It is characterized by being a powder of a system oxide, gold, platinum, silver, and copper.

According to a fifth aspect of the present invention, in the first aspect, the igniter comprises a heating element and an explosive attached to the heating element. A sixth aspect of the present invention is characterized in that, in the first aspect, a pressing member having an ejection port is disposed between the main agent container and the gas ejection portion.

[0015]

The heat of decomposition of hydrogen peroxide is extremely high as shown in the following equation, but an aqueous solution containing 64.5% by weight or less cannot evaporate the entire liquid, so a runaway reaction will not occur. Absent. H ₂ 0 ₂ → H ₂ 0 + 0.50 ₂ +98.2 kJ FIG. 1 shows changes in the composition and temperature of the produced gas with respect to the concentration of the aqueous hydrogen peroxide solution.

In the figure, X (H ₂ 0), X indicated by a solid line
(0 ₂ ) represents the molar concentration of the decomposed gas at each concentration,
Y (H ₂ 0) and Y (0 ₂ ) represent the concentration in volume percentage. Further, the state of the gas at the time of decomposition can be known from the concentration of the aqueous hydrogen peroxide solution shown in the figure. That is, when the content of hydrogen peroxide is 11.5% by weight or less, it does not vaporize even when heat is applied and the liquid state is maintained. It is also understood that when the hydrogen peroxide content is 64.5% by weight or more, the water becomes heated steam and the decomposition gas temperature rises sharply. For example, when the hydrogen peroxide content is 100% by weight, the decomposition gas temperature is 100%.
Indicates near 0 ° C.

However, when the hydrogen peroxide content is in the range of 11.5% by weight to 64.5% by weight, it exists in the state of saturated water vapor, and in the case of normal pressure, due to the high latent heat of vaporization of water, The temperature is suppressed, and the decomposition gas temperature of the hydrogen peroxide aqueous solution reaches a peak at 100 ° C. (saturated water vapor temperature). Further, it can be seen from FIG. 1 that the decomposition gas temperature can be suppressed to about 200 ° C. even when the pressure is 10 atm.

If the hydrogen peroxide content used here is 60% by weight, the decomposition gas composition is limited to water vapor containing 18% by weight of oxygen and a slight amount of liquid water. It can be seen that a clean gas having a composition substantially similar to that is generated.

Further, since the pressure when the airbag is deployed is about atmospheric pressure + 1atm, the gas temperature can be suppressed to 110 ° C. or lower. Therefore, unlike other gas generating agents, there is no possibility that the decomposition products will burn the bag material at all, and no flame is generated. FIG. 2 shows the basic physical properties of the hydrogen peroxide solution.

In the figure, (A) shows the boiling point and specific gravity at each concentration, and (B) shows the changes in the hydrogen peroxide aqueous solution concentration and the freezing point. From (B), the hydrogen peroxide content is 60
It can be seen that the minimum value of the freezing point is exhibited at the weight%.
The inflator needs to maintain a constant performance even in a severe low temperature environment where the vehicle is placed. Therefore, it is necessary to avoid the trouble that the hydrogen peroxide solution freezes even in a low temperature environment.

However, FIG. 2B shows that even at a low temperature environmental requirement value of -30 ° C., no freezing occurs. Figure 2
In (B), the horizontal axis shows the concentration of hydrogen peroxide and the vertical axis shows the temperature, and the curve shows the freezing point at each content rate and connects the points. The numerical values shown in the figure are freezing points at typical contents.

From this figure, the hydrogen peroxide content is 60% by weight.
It can be seen that the freezing point shows a minimum value of -55.4 ° C. This indicates that a hydrogen peroxide content of 60% by weight does not freeze under an environment of -55.4 ° C or higher. Further, the freezing point of hydrogen peroxide becomes higher than that regardless of whether the content of hydrogen peroxide is 60% by weight as the minimum value and the process proceeds to either the high concentration side or the low concentration side. For example,
When the hydrogen peroxide content is 50% by weight, it becomes -50.0 ° C, when the hydrogen peroxide content is 70% by weight, it becomes -40.2 ° C, and when the hydrogen peroxide content is 35% by weight, it becomes -32.6 ° C. .
Therefore, in order to satisfy the low temperature environment requirement value of -30 ° C, the problem of freezing cannot be avoided unless the hydrogen peroxide content is 35% by weight or more. From the above, the hydrogen peroxide content is 35% to 64.5% by weight, preferably 40% to 60% by weight.

[0023] Furthermore, the hydrogen peroxide content is 1
It can be seen that in the range of 1.5% by weight to 30% by weight, hydrogen peroxide cannot achieve the original purpose of generating gas in a low temperature environment. In addition, FIG. 2A also shows a boiling point of 120 ° C., which is not a problem, when the content of hydrogen peroxide is 60% by weight with respect to the high temperature environmental requirement value of + 80 ° C.

This indicates that the aqueous hydrogen peroxide solution has a sufficient permissible range for the environmental temperature of the inflator. As described above, the medium-concentration hydrogen peroxide used in the present invention can be highly safe and secure when it is stored and stored in an airtight state when it is applied to an air bag and placed in an environment where an increase in the concentration can be avoided.

As described above, in order to protect the occupant by deploying the air bag for an automobile, at least 50 mse.
It is necessary to complete the decomposition reaction within c and generate gas to inflate the airbag 100%. The present invention is characterized in that this decomposition rate is provided. That is, the substance of claim 4 described as a catalyst for decomposing hydrogen peroxide, an ignition charge,
An explosive called a transfer charge is mixed, and the substance shown in claim 4 is diffused into hydrogen peroxide within several msec by using a decomposition reaction close to the subsonic velocity of the explosive. Decomposition can be completed within 50 msec depending on the combustion heat of the explosive and the diffusion rate of the decomposition catalyst.

This makes it possible to generate gas at a rate 1000 times faster than the gas generation rate of the gas generator disclosed in JP-A-56-88804, and is fundamental from the viewpoint of speed. There is a difference.

[0027]

EXAMPLES The present invention will now be described with reference to examples.

Embodiment 1 FIG. 3 shows an embodiment of an airbag gas generator according to claims 1 to 6. In the figure, 10 represents a gas generator main body. The gas generator body 10 is made of, for example, a stainless steel material of SUS 304, and has an outer cylinder 11 having a flange portion 12, and a head attached to the flange portion 12 of the outer cylinder 11 to close the opening of the outer cylinder 11. The metal fitting 23 and the top metal fitting 33 screwed into the recess 24 of the head metal fitting 23 are provided.

The outer cylinder 11 has an annular flange portion 1 on the upper side.
2, a step portion 14 is provided on the lower side, and a tubular body 15 projecting downward from the step portion 14 is integrally provided. The flange portion 12 is provided with a bolt insertion hole 17 and an annular hole 18 for mounting a seal member 19 such as an O-ring.
A storage portion 20 is provided at the opening end 16 of the inner wall portion 13 of the outer cylinder 11 to fit the outer portion of the annular projection 31 of the head metal fitting 23. A female screw 21 for screwing a head holding cap 90, which will be described later, is provided on the lower portion of the housing portion 20.

The head metal part 23 is provided with a cylindrical recess 24 having a plurality of nozzles 25 formed in the bottom thereof in the center thereof. A female screw portion 25 for screwing the top fitting 33 is formed in the recess 24. An annular flange portion 26 having an outer diameter equivalent to that of the flange portion 12 of the outer cylinder 11 is integrally provided on the annular wall portion 32 on the outer periphery of the recess 24.
The flange portion 26 has a bolt insertion hole 27 and a screw insertion hole 2
8 are provided.

An annular hole 29 for mounting a seal member 30, such as an O-ring, is provided above the flange portion 26 in the annular wall portion 32 on the outer periphery of the recess 24. An annular projection 31 for positioning is provided on the surface opposite to the recess 24.

The top fitting 33 includes a cylindrical main body 34 and a conical gas ejection portion 34 provided on the upper portion of the main body 34.
A through hole 35 provided in the central portion of the main body 34, and the main body 34
And a male screw portion 36 provided on the outer periphery of the. The gas ejection portion 34 is formed of a roof portion 37 protruding in a conical shape from the upper side of the main body 34, and a nozzle portion 38 formed of a plurality of small holes provided on the slope of the roof portion 37. Nozzle part 3
8 has an angle in order to reduce the vertical impact of the airbag 48.

A space 39 is formed between the gas ejection portion 34 and the through hole 35. In the through hole 35,
A perforated plate 40, a metal net 41 of copper or the like, a perforated plate 40, and a cylindrical pressing metal fitting 42 are mounted in this order toward the space 39. The cylindrical pressing member 42 is provided with a male screw 43 on the outer circumference and is screwed to a female screw 44 formed on the wall surface of the through hole 35.

An annular hole 45 for mounting a seal member 46 such as an O-ring is provided on the bottom surface of the top fitting 33 which is in contact with the head fitting 23. The top fitting 33 is the airbag 4
It is fixed by a mounting bracket 47 for fixing 8 so as not to fall off. The attachment metal fitting 47 is in close contact with the outside of the annular wall portion 32 of the head metal fitting 23, and the annular locking claw portion 5 at the tip end.
1 makes contact with the root portion of the gas ejection portion 34.

The airbag 48 is fixed to the head metal fitting 23 and the mounting metal fitting 47 by a screw 50, and the bolt 4
It is fixed to the outer cylinder 11, the head fitting 23, and the mounting fitting 47 by 9. On the other hand, in the outer cylinder 11, the decomposition catalyst container 60, the main agent container 80, and the pressing cap 90 are arranged in this order from the step 14 toward the opening end 16.

The decomposition catalyst container 60 has a main body 61 having a T-shaped outer shape and a through hole 62 having a T-shaped cross section in the center, and a decomposition catalyst 63 for hydrogen peroxide filled in the through hole 62. The igniter 64 is attached to the rear of the hydrogen peroxide decomposition catalyst 63. The main body 61 includes a support fixing portion 65 having an outer diameter substantially the same as the inner diameter of the inner wall portion 13 of the outer cylinder 11, and a shaft portion 66 having an outer diameter substantially the same as the inner diameter of the tubular body 15 of the outer cylinder 11. Have.

On the upper and lower surfaces of the supporting and fixing portion 65, an annular hole 67 for mounting a seal member 68 such as an O-ring and an annular hole 69 for mounting a seal member 70 such as an O-ring are provided. The shaft portion 66 is longer than the tubular body 15 of the outer cylinder 11, and the tubular body 15 of the outer cylinder 11 when the decomposition catalyst container 60 is mounted.
More prominent. A male screw 71 is provided on the shaft portion 66.

A lock nut 72 is attached to the shaft portion 66 protruding from the cylindrical body 15 of the outer cylinder 11 when the decomposition catalyst container 60 is mounted.
Is screwed and fixed. The igniter 64 is formed by attaching explosives to a heating element that generates heat when energized. As the heating element, for example, a thin film resistor, a nichrome wire or the like is used. Examples of explosives include black powder, lead rhodan, tricinate, and the like.

The igniter 64 has a shaft 66 with a lock nut 7
It is fixed by screwing 4 on. Its leg 73
Are pulled out from the lock nut 74. Igniter 64
Is ignited by an operation command based on a signal from an acceleration sensor which detects a collision accident or a self-damage accident via a leg 73. As the hydrogen peroxide decomposition catalyst 63, alkali metal or alkaline earth metal permanganate, alkali metal or chromate composed of gold, platinum, silver, copper, lanthanoid oxide, gold, platinum, silver ， There is copper powder.

A pressure adjusting plate 75 having a plurality of nozzles 76 is mounted on the decomposition catalyst container 60. A starter cap 77 is placed on the pressure adjusting plate 75. A nozzle 78 is also provided in the starter cap 77. On the starter cap 77, there is an aqueous solution having a hydrogen peroxide content of 64.5% by weight or less and a melting point of 1%.
A main agent container 80 containing a main agent 81 at 27 ° C. or lower is placed.

The main agent container 80 is obtained by filling a bag made of a synthetic resin such as polyethylene with the main agent 81, and then sealing the head by caulking or heat. A pressing cap 90 is screwed onto the main agent container 80. As shown in FIGS. 3 and 4, the pressing cap 90 is a tubular body having an inverted T-shaped cross section. At the lower edge 91, the outer cylinder 11
A male screw portion 92 that is screwed into the female screw portion 20 provided on the inner wall portion 13 is provided. The ceiling portion 94 is closed, and the side wall portion is provided with a plurality of ejection ports 93.

Next, the assembly of the gas generator for an air bag according to this embodiment will be described. First, the decomposition catalyst container 60
Is inserted into the outer cylinder 11 from the shaft portion 66. Next, the outer cylinder 11
To the shaft portion 66 protruding from the protruding body 15 of the lock nut 72.
Is screwed to securely support and fix the decomposition catalyst container 60 on the stepped portion 14 in the outer cylinder 11. At this time, the decomposition catalyst 63 and the igniter 64 are pre-loaded in the decomposition catalyst container 60. Further, the decomposition catalyst container 60 is covered with a pressure adjusting plate 75 and a starter cap 77 on the upper part.

Next, the lock nut 74 is screwed to the shaft portion 66 on the leg 73 side of the igniter to prevent the igniter 64 from falling off. With this lock nut 74, the decomposition catalyst container 60
The end of the shaft portion 66 and the end of the igniter 64 are securely closed. A leg 73 protruding from the lock nut 74 communicates with a control device (not shown). Here, as the hydrogen peroxide decomposition catalyst 63, a potassium permanganate-based decomposition catalyst,
As the igniter of the igniter 64, black powder, boron / potassium nitrate, and ammonium perchlorate solid propellant were used.
The black powder also plays a role of rapidly dispersing the decomposition catalyst in the hydrogen peroxide solution.

Next, on the starter cap 77, an aqueous solution having a hydrogen peroxide content of 64.5% by weight or less,
A main agent container 80 containing a main agent 81 having a melting point of 127 ° C. or lower is placed. Next, on the main agent container 80,
The male screw 92 provided on the outer circumference of the pressing cap 90 is attached to the outer cylinder 1.
It is fixed by being screwed onto the female screw 20 provided on the inner wall surface 13.

Next, the opening side of the outer cylinder 11 is closed by the head metal fitting 23 and fixed by the bolt 49. Here, the head metal fitting 23
The top metal fitting 33 is screwed into the concave portion 24 and the air bag 48 is attached thereto. Further, a mounting bracket 47 is mounted above the airbag 48, and these are fixed via a screw 50. By the above, FIG.
The assembly of the gas generator for the airbag shown in is completed.

Next, the operation of the air bag gas generator will be described. Normally, the main agent container 80 is completely sealed, so that it does not leak to the outside in any state. Further, since the main agent container 80 is fixed to the upper and lower sides by the starter cap 77 and the pressing cap 90, the main agent container 80 is not likely to be displaced even if vibration occurs.

Therefore, when a collision accident or a self-damage accident causes the ignition tool 64 to be ignited via the leg 73 in response to an operation command based on a signal from an acceleration sensor that detects the accident, the decomposition catalyst container 60 is ignited. However, the base material container 80 is broken by the heat and impact. At the same time, the cracking catalyst 63 in the cracking catalyst container 60 is diffused into the outer cylinder 11, and the cracked catalyst 63 is diffused.
And hydrogen peroxide come into contact with each other, hydrogen peroxide begins to decompose,
Generates water and oxygen gas.

The generated oxygen gas is retained by the pressing cap 90.
Head metal fitting 2 through the space 100 between the pressing cap 90 and the inner wall portion 13 of the outer cylinder 11 via the ejection port 93 of
No. 3 nozzle 25 flows into the through hole 35 of the top fitting 33. In the through holes 35, after removing unreacted components by a filter composed of the perforated plate 40, the wire netting 41 and the perforated plate 40, oxygen gas is introduced into the space 39 and the nozzle portion 38 of the gas ejecting portion 34 inside the airbag 48. Intrude into.

Thus, the airbag 48 is inflated.
The decomposition rate of hydrogen peroxide is controlled by the kind and amount of the ignition charge, the kind of the decomposition catalyst, the particle size, and the dispersion efficiency in the solution.
FIG. 6 shows the pressure-temperature curve of the produced gas in this example. In the figure, indicates pressure and indicates temperature.

As is apparent from the pressure curve of, the pressure becomes maximum about 50 msec after the ignition signal is sent,
Data was obtained that the maximum pressure reaches 2.5 MPa. On the other hand, as is clear from the temperature curve of 1, the maximum temperature is about 20 msec after the ignition signal is sent.
Data was obtained that reached 0 ° C. From the above, it was confirmed that 55 ml of an aqueous solution containing 60% by weight of hydrogen peroxide was sufficient to rapidly inflate a 60-liter airbag.

In the above example, 55 ml of an aqueous solution containing 60% by weight of hydrogen peroxide was used, but the present invention is not limited to this.
It is clear from the above description of the operation. Example 2 Using the gas generator for an air bag shown in Example 1, the output characteristics of pressure under temperature environment were confirmed. The gas generator and its assembling method are exactly the same as those shown in the first embodiment.

In this example, the hydrogen peroxide content was 30% by weight.
And a 60% by weight product were used. The gas generator assembled by the assembling method shown in Example 1 was left in a low temperature bath at -30 ° C. After standing for 4 hours or more, the sample was taken out and subjected to a pressure rise test within 5 minutes. FIG. 7 shows the result of the pressure rise test at each concentration. As is clear from this result, even under a low temperature environment of −30 ° C., a hydrogen peroxide aqueous solution having a content of 60% by weight can output a tank pressure equivalent to that at room temperature.

On the other hand, the content of 30% by weight is 300
It was found that the pressure started to rise in about msec, and it did not have the performance as a gas generator for an air bag at a low temperature. This result indicates that the usable range is limited to those having a hydrogen peroxide content of 35% by weight or more, as is apparent from the above-described action. Example 3 Using the gas generator for an air bag shown in Example 1,
The deployment test of the airbag actually used was conducted.

In the test, 70 ml of the sample amount in the main agent container 80 (hydrogen peroxide content 60% by weight), the components of the igniter 64 were 0.2 g of black powder powder and granules, 0.6 g of pellet boron / potassium nitrate, 0.3 g of ammonium perchlorate solid propellant and 0.7 g of potassium permanganate as a decomposition catalyst 63 for hydrogen peroxide were used. Also, the airbag 48
Has a capacity of 60 liters and the nozzle part 3 of the gas ejection part 34.
The diameter of 8 was 15 mm. The air bag 48 was folded in the same manner as a normal air bag and fixed at two places with tape.

The results are shown in FIGS. The figure is
The bag deployment photograph taken using a high speed bidet capable of photographing 250 frames per second is shown. The maximum expansion in the vertical direction reaches 32 msec after the energization, and the vibration of the airbag 48 is almost completed in 40 msec. 48msec-56mse
In c, the deployment of the airbag 48 is completed and the shape becomes uniform.
Reach the fill time.

After 64 msec, the shape is stable and 100
It was found that the airbag 48 was deflated after about msec. The gas after deployment of the airbag 48 was clean and had no peculiar odor. Also, as a matter of course, there was no irritating odor when an azide of an alkali metal was used for the airbag 48.

According to this test, 90% of the airbag 48 was deployed within 50 msec, and it was possible to deploy the airbag with a gas generator using hydrogen peroxide in the same time as a commercially available airbag gas generator. I was able to prove it.

[0058]

As described above, according to the invention described in claims 1 to 6, an aqueous solution of hydrogen peroxide whose content rate does not exceed 64.5% by weight is adopted as a main agent, and an appropriate igniter is obtained. By selecting a catalyst and designing a module that enables its rapid decomposition, it is possible to construct an airbag system that guarantees a long service life.

That is, the remarkable advantages of the present invention are:
This is because the combustion (decomposition) products utilize only oxygen and water vapor and the properties of hydrogen peroxide, which is completely harmless to the human body, to overcome practical difficulties. Therefore, even if the gas temperature flowing out from the gas generator using the hydrogen peroxide aqueous solution whose content rate does not exceed 64.5% by weight is considerably increased due to the pressure increase, it is 251
Since the temperature is lower than 0 ° C., unlike other gas generating agents, there is no possibility that the decomposition products burn the air bag material made of cloth.

Further, since no flame is generated and the temperature of the air bag surface is as low as about 167 ° C., there is no possibility of being burned by steam of decomposition gas and oxygen.

[Brief description of drawings]

FIG. 1 is a diagram showing changes in the composition and temperature of a produced gas with respect to the concentration of an aqueous hydrogen peroxide solution.

FIG. 2 is a diagram showing basic characteristics of an aqueous hydrogen peroxide solution.

FIG. 3 is a cross-sectional view showing a first embodiment of an airbag gas generator according to claims 1 to 6.

4 is a plan view of the airbag gas generator shown in FIG. 2. FIG.

5 is a perspective view of a holding cap of the airbag gas generator shown in FIG. 2. FIG.

FIG. 6 is a diagram showing a pressure-temperature curve of gas produced by the gas generator for an airbag shown in FIG.

FIG. 7 is a diagram showing the results of a pressure rise test (−30 ° C.) at each concentration of the second embodiment of the gas generator for an airbag according to claims 1 to 6.

FIG. 8 is a bag development photograph of Example 3 showing 20 ms.
The state of ec is shown.

FIG. 9 is a bag development photograph of Example 3 showing 24 ms.
The state of ec is shown.

FIG. 10 is a developed photograph of the bag in Example 3, showing a length of 32 m.
Indicates the state of sec.

FIG. 11 is a developed photograph of the bag in Example 3, showing a length of 40 m.
Indicates the state of sec.

FIG. 12 is a bag development photograph of Example 3, showing a length of 48 m.
Indicates the state of sec.

FIG. 13 is a developed photograph of the bag in Example 3, showing a length of 56 m.
Indicates the state of sec.

FIG. 14 is a developed photograph of the bag in Example 3, showing a length of 64 m.
Indicates the state of sec.

FIG. 15 is a bag development photograph of Example 3, showing a length of 82 m.
Indicates the state of sec.

[Explanation of symbols]

 10 Gas Generator Main Body 11 Outer Cylinder 23 Head Metal Fitting 24 Recessed Mold 33 Top Metal Fitting 34 Gas Ejection Part 38 Nozzle Part 40 Perforated Plate 41 Wire Mesh 42 Holding Metal Fitting 47 Mounting Metal Fitting 48 Airbag 60 Decomposition Catalyst Container 63 Hydrogen Peroxide Decomposition Catalyst 64 Ignition tool 66 Shaft section 80 Main agent container 81 Main agent 90 Holding cap 93 Spout

Claims (6)

[Claims] 1. A main agent container containing a main agent having a hydrogen peroxide content of 64.5% by weight or less and a melting point of 127 ° C. or less, and a decomposition catalyst containing a hydrogen peroxide decomposition catalyst. A container, an igniter mounted in the decomposition catalyst container, and a gas generator main body that accommodates the igniter, the decomposition catalyst container, and the main agent container in this order and has a gas ejection portion above the main agent container. A gas generator for an air bag characterized by the following. 2. The gas generator for an air bag according to claim 1, wherein the main component is an aqueous solution having a hydrogen peroxide content of 35% by weight to 64.5% by weight. 3. The gas generator for an air bag according to claim 1, wherein the main component is an aqueous solution having a hydrogen peroxide content of 40% by weight to 60% by weight. 4. The catalyst for decomposing hydrogen peroxide according to claim 1, wherein the alkali metal or alkaline earth metal permanganate, an alkali metal or a chromate composed of gold, platinum, silver, copper, or a lanthanoid-based catalyst is used. A gas generator for an airbag, which is a powder of oxide, gold, platinum, silver, and copper. 5. The gas generator for an air bag according to claim 1, wherein the igniter includes a heating element and an explosive attached to the heating element. 6. The gas generator for an air bag according to claim 1, wherein a pressing member having an ejection port is disposed between the main agent container and the gas ejection unit.