JPH0516752A - Air bag - Google Patents

Abstract

PURPOSE:To suppress a harmful strong alkaline substance to be discharged from a vent hole of an air bag at the time of vehicle collision by making a substance generating an acid at a high temperature or with a shock hold in a state protected with a microcapsule inside the air bag. CONSTITUTION:A foundation cloth 4 of an air bag 1 is formed out of a synthetic fiber cloth such as nylon or a synthetic fiber nonwoven fabric and its inside is coated with a coating material 5 of rubber or resin. Further to the inside thereon, an ammonium salt as an acid generating substance 6, for example, ammonium acetate, ammonium sulfate or the like is applied in a state held in a microcapsule consisting of a synthetic resin, an activated carbon and the like. When a vehicle collision occurs, a strong alkaline substance generated together with a nitrogen gas due to a reaction of a nitrogen gas generating agent such as sodium azide housed in an inflater 2 is discharged from a vent hole 3 at the time of contraction, but an acid is generated by the ammonium salt through breakage of the microcapsule to neutralize the harmful strong alkaline substance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bag which is inflated when a vehicle, in particular, a vehicle crashes, absorbs a shock of a seated occupant and protects the same. More specifically, it relates to an airbag coated with a substance that generates an acid when exposed to high temperatures and / or impacts.

[0002]

2. Description of the Related Art In recent years, airbags for ensuring the safety of passengers in vehicles such as vehicles, ships and airplanes, especially automobiles have been attracting attention in place of seat belts. This airbag has also attracted attention as an auxiliary device for seat belts, and is actually mounted on some vehicles.

Conventionally, air bags have 400 to 1000.
To improve heat resistance, flame retardancy, air barrier property, etc., chloroprene, hypalon, on the inner surface side of a plain woven fabric using denier nylon 6.6 or nylon 6 filament yarn.
Those coated with rubber such as silicone are used.

In the case of an automobile collision, an airbag receives a shock of a collision, and an oxidizer such as potassium zirconium perchlorate or potassium boron nitrate, which is called an igniter, is used as a nitrogen gas generating agent such as azide. It is intended to heat sodium and generate high-temperature, high-pressure nitrogen gas, and to inflate the airbag instantaneously by this nitrogen gas to protect the occupant's face, especially the face during a collision.

[0005] Sodium azide as a nitrogen gas generating agent generates nitrogen gas by heating the igniting agent and inflates the airbag, but at the same time metallic sodium is generated as a decomposition product. This metallic sodium is changed into sodium hydroxide and sodium carbonate by the moisture in the air and carbon dioxide, respectively, but in any case, a strong alkaline substance is generated, and when the airbag contracts due to the contact with the face after the inflation, the vent hole releases nitrogen. At the same time as gas, a large amount of harmful strong alkaline substances are released into the vehicle.

Also, since a large amount of strong alkaline substance adheres to the used airbag after a vehicle collision, even when the used airbag is discarded, rubber gloves should be worn so as not to adhere to the skin. Therefore, it was necessary to neutralize it with an acid and discard it, and the handling was extremely complicated.

[0007]

SUMMARY OF THE INVENTION In view of the above drawbacks of conventional airbags, it is an object of the present invention to suppress harmful strong alkaline substances released from the vent holes of the airbag during a vehicle collision, and to prevent the use of the used airbag. Handling airbags,
It is easy to discard.

[0008]

In order to achieve the above object, the present invention has the following constitution.

That is, the air bag of the present invention is an air bag made of a base fabric composed of a synthetic fiber woven fabric or a synthetic fiber non-woven fabric, and the inner surface of the airbag contains a substance capable of generating an acid by high temperature or impact. It is characterized by doing.

[0010]

[Function] As the synthetic fiber in the present invention, nylon 6, nylon 6.6, nylon 12, nylon 4.6,
And a copolymer of nylon 6 and nylon 6.6, polyamide fiber obtained by copolymerizing nylon with polyalkylene glycol, dicarboxylic acid, amines, etc., homopolyester such as polyethylene terephthalate, polybutyl terephthalate, and repeating unit of polyester. Polyester fiber obtained by copolymerizing acid component with aliphatic dicarboxylic acid such as isophthalic acid, 5-sodium sulfoisophthalic acid or adipic acid, aramid fiber typified by copolymerization with paraphenylene terephthalamide and aromatic ether, rayon It is possible to use fibers, ultra high molecular weight polyethylene fibers, sulfone fibers such as paraphenylene sulfone and polysulfone, polyetherketone fibers, carbon fibers, single fibers or composite fibers composed of glass fibers. That. Among these fibers, polyamide, particularly fibers made of nylon 6.6 or nylon 6 are preferable because they have excellent airbag characteristics. Further, although these fibers may be long fibers or short fibers, it is preferable to use long fibers.

The synthetic fiber may contain various additives which are usually used for improving the productivity or the characteristics in the manufacturing process and the processing process of the raw yarn. For example, a heat stabilizer, an antioxidant, a light stabilizer, a smoothing agent, an antistatic agent, a plasticizer, a thickener, a pigment, a flame retardant and the like can be contained.

A plain weave is usually selected as the woven fabric,
If necessary, satin weave, twill weave, and modified weaves thereof may be used. As the non-woven fabric, one produced by the so-called spun bond method, flash method or the like is used.

On the inner surface side of the synthetic fiber woven fabric or the base fabric made of the synthetic fiber non-woven fabric, chloroprene, hypalon, fluorine, silicone, natural rubber, or vinyl chloride is added in order to improve heat resistance, flame retardancy and air barrier property. A material coated with an elastomer resin such as chlorinated olefin, polyurethane, polyester, or polyamide is used, but the base fabric in the present invention is not limited to these rubbers as long as it has the necessary properties as an airbag. A so-called non-coated base cloth on which no resin is applied may be used.

In the present invention, the inner surface of the airbag contains a substance capable of generating an acid at high temperature and / or impact. The substance contained is preferably a neutral substance until the inflator is activated due to a collision accident and the airbag is inflated / deployed, and the inflator is activated to generate an acid when the airbag is inflated / deployed. It is preferably a substance.

However, if an acid is generated until the airbag is inflated / deployed, that is, when it is stored, for example, sodium azide which is usually used as a nitrogen gas generating agent is toxic and explosive hydrazoic acid. Is generated, which is not preferable. Therefore, melamine is a substance that is neutral when stored and that generates an acid only when the airbag is inflated and expanded, such as ammonium salts such as ammonium acetate, ammonium sulfate, and ammonium chloride, and acidic substances such as acetic acid, sulfuric acid, and hydrochloric acid. A microcapsule made of a resin, a synthetic resin such as an acrylic resin, or activated carbon can be preferably used.

The particle size of the microcapsules used here is preferably about 0.1 to 30 μm, more preferably about 1 to 10 μm. The acidity of these substances that generate acid when the airbag is inflated / deployed corresponds to the amount of sodium azide used as a nitrogen gas generating agent, and the amount necessary for neutralization is contained by a method such as coating. You can do it. Such an acid-generating substance generates an acid due to high temperature or impact due to inflation / deployment of an air bag, ammonium salt to decompose / volatilize ammonia, and microcapsules to destroy an acid. The strong alkaline substance generated by the nitrogen gas generating agent is neutralized. The acid-generating substance is contained by being applied to the inside of the airbag, for example, on the inner surface side of the base fabric, but there is no limitation on the way of containing such substance, and for example, the applying method may be a brush, knife coat, spray or the like. And the like can be used.

The present invention will be further described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of an airbag 1 according to the present invention, in which an inner surface side of a base cloth 4 is coated with a chloroprene rubber, a silicone rubber, or an elastomer resin 5 such as polyurethane or polyester, and the surface thereof. 2 shows an airbag 1 in which a substance 6 that generates an acid is contained, and FIG. 2 is a cross-sectional view showing another example of the airbag 1 according to the present invention. Alternatively, there is shown an airbag 1 which is not coated with resin and is made of a so-called non-coated base cloth, in which an acid generating substance 6 is contained on the inner surface thereof. In the figure, 2 is an inflator and 3 is a vent hole. The base cloth 4 is made of synthetic fiber woven fabric or synthetic fiber non-woven fabric.

The nitrogen gas generator contained in the inflator 2 is not particularly limited, but sodium azide (NaN ₃ ) is preferably used. When heated, these compounds generate high-temperature, high-pressure nitrogen gas and have the ability to inflate the airbag instantaneously, and exert the action of protecting the occupant, especially the face, in the event of a collision. However, this sodium azide is decomposed to simultaneously generate metallic sodium, and moisture in the air, nyllium hydroxide and sodium carbonate changed by carbon dioxide, and these compounds are released from the vent hole 3.

In the present invention, the substance 6 which generates an acid when the airbag is inflated / expanded by high temperature or impact is contained in the inside of the airbag by a method such as coating, which is a decomposed product of sodium azide. It is possible to instantly neutralize certain metallic sodium, sodium hydroxide and sodium carbonate to suppress the release of harmful strong alkaline substances from the vent holes.

[0020]

EXAMPLES The present invention will be described in more detail with reference to Examples.

Example 1 Nylon 6.6 fiber having a total fineness of 840 denier, 162 filaments and a strength of 9.3 g / denier was used.
A plain weave having a warp and weft density of 25 yarns / inch was obtained. Then, after scouring, drying and intermediate setting by a usual method, 104 g / m ^{2 of} chloroprene rubber was coated. After coating the coated surface of the coated cloth with ammonium acetate particles at 200 g / m ² , two pieces of the cloth are cut into a circle having a diameter of 80 cm, the coated surface is on the inside, and the outer periphery is sewn to obtain an airbag. It was

Then, an air bag was attached to an inflator using 250 g of sodium azide as a nitrogen generating agent, an inflator test was conducted, and a portion of the sample after the test facing the inflator mounting portion was sampled in a size of 20 cm × 20 cm and evaporated in 1 l of evaporated water. After immersing in water for 1 hour, the pH of water was measured. The evaluation results are shown in Table 1.

Example 2 Using the coated fabric of Example 1, 200 g / m ² of a particulate substance having an average particle size of 1.2 μ, which was obtained by microencapsulating acetic acid with a melamine resin, was applied to the coated surface. After that, an airbag was obtained by the same method as in Example 1 and the same test was performed. The evaluation results are shown in Table 1.

Comparative Example 1 Using the coated fabric of Example 1, an airbag was formed as it was, and the same test as in Example 1 was performed thereafter. The evaluation results are shown in Table 1.

[0025]

[Table 1]

As is clear from Table 1, in Comparative Example 1, strong alkaline substances remained in the airbag due to the decomposition of sodium azide after the inflator test, but in Examples 1 and 2, the strong alkaline substances were neutralized. Was there.

[0027]

According to the present invention, a highly safe airbag is provided which neutralizes harmful strong alkaline substances emitted from the vent hole of the airbag in the event of a vehicle collision and suppresses the harm of the chemicals to the human body. can do. In addition, the collision / used airbag can be easily handled and discarded, the cost of the airbag can be indirectly reduced, and the occupant protection system using the airbag can be promoted widely.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an airbag according to the present invention in which an elastomer resin is applied on the inner surface side and a substance 6 that generates an acid is contained on the surface.

FIG. 2 is a cross-sectional view of another example of the airbag according to the present invention, in which the base fabric on the inner surface side of the airbag contains a substance 6 that directly generates an acid.

[Explanation of symbols]

1: Airbag 2: Inflator 3: Bent hole 4: Base cloth 5: Coating material 6: Acid generator

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location D06M 15/248 7199-3B

Claims (3)

[Claims] 1. An air bag comprising a base fabric composed of a synthetic fiber woven fabric or a synthetic fiber non-woven fabric, wherein the inner surface of the airbag contains a substance capable of generating an acid upon high temperature or impact. bag. 2. The airbag according to claim 1, wherein the substance that generates an acid is an ammonium salt. 3. The airbag according to claim 1, wherein the substance that generates an acid is protected by microcapsules.