JP3461517B2 - Airbag - Google Patents

Abstract

PURPOSE:To provide weight reduction, softer feeling, and improved storage in an air bag for a vehicle by using a layered element with rough fiber and film in base cloth. CONSTITUTION:Rough texture whose mesh is at 1-40nm is formed from filament fiber such as nylon 6. It is desirable that the tensile strength of the filament fiber should be 7g/denier or more because it compensates the tearing force of layered films. Besides, it is desirable that total fineness should be as fine as possible within a range of 200-200 denier. Moreover, film which is made of polyethylene phtharate is layered on rough cloth to form base cloth. The thickness of the film is 100mum or less, and the breakage ductility is 200% or more. The film is layered by laminating it directly on one or both side surface(s) of the rough texture by conjugation with adhesive agent or melting polymer at the time of producing film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an airbag which is inflated when a vehicle, for example, an automobile collides, absorbs a collision of a seated occupant, and protects the collision.

[0002]

2. Description of the Related Art In recent years, the practical use of airbags for ensuring the safety of passengers in automobiles has been rapidly increasing. In the case of a collision accident of a car, the sensor receives a shock of collision and generates high temperature and high pressure gas, and the high temperature and high pressure gas momentarily inflates the airbag,
It is intended to protect the occupants, especially their faces, in the event of a collision. Conventional airbags are made of plain woven fabric using nylon 6 or nylon 6.6 filament yarn of 400 to 1000 denier, and chloroprene, chlorosulfonated olefin, etc. for improving heat resistance, flame retardancy and air barrier properties. It was made by applying an elastomer such as synthetic rubber or natural rubber, cutting the laminated base fabric, and sewing. The airbag is stored in a narrow space such as the steering wheel and instrument panel until just before it is activated. The smaller the storage volume, the better, and the softer, lighter and thinner the base cloth is, the better. . However, the conventional airbag is thick and heavy because the elastomer is applied and laminated with a certain thickness for the purpose of improving various characteristics as an airbag, and the texture is hard, so the foldability is poor, Not only does it have a large storage capacity, but it also has a strong impact on the human body, especially the face during momentary expansion due to high temperature and high pressure gas. However, it was not preferable.

To address this problem, JP-A-1-31784
No. 7 discloses an airbag sheet comprising a laminated sheet in which a plurality of perforated plastic films are laminated so that the positions of the holes of each film are displaced, and the holes are filled with an adhesive to be integrated. Is proposed. Also,
Japanese Unexamined Patent Publication (Kokai) No. 2-31965 proposes an airbag device made of an aromatic polyamide film.

[0004]

However, although the former air bag made of a perforated plastic film can be made thinner and lighter, it can be made to have a smaller storage volume than a conventional air bag. Since an adhesive is filled in the holes of the perforated film and a plurality of films are laminated, the adhesive is exposed from the film, and the workability at the time of production is remarkably poor. Further, if the perforated plastic films are laminated so that the positions of the holes of each film are displaced, it is necessary to laminate about 10 sheets, which makes the process extremely complicated and the cost is high.

The latter air bag made of an aromatic polyamide film is preferable in terms of heat resistance and small size and light weight, but has extremely small tear strength and has a slight scratch on the film. In this case, the air bag is extremely fragile and lacks reliability as an airbag.

Films generally have a higher tensile strength per unit thickness than cloth, but they have a low tear strength, so that ordinary films can sufficiently obtain the mechanical strength required for airbags. There was a drawback that I could not.

In view of the above drawbacks of the conventional airbag, the present invention maintains the mechanical characteristics of the airbag,
The purpose of the present invention is to provide an airbag that is lightweight, thin, soft in texture, and excellent in storability.

[0008]

The present invention has the following constitution in order to achieve the above object. That is, the airbag of the present invention comprises, as a base fabric constituting the airbag, a woven yarn having a fiber strength of 7 g / denier or more.
A coarse woven fabric having a mesh size of 6 to 20 mm and a breaking elongation of 20.
It is characterized by using a laminate formed by bonding a film of 0% or more .

[0009]

The present invention has reached the point of incorporating a specific woven fabric as a result of intensive studies to reinforce the weak points of the film and realize the weight reduction while making full use of the characteristics of the film. . That is, by combining and joining a specific coarse woven fabric and a film, the mechanical properties and the weight saving are both satisfied, and further, it is necessary for an airbag that has a thin, soft texture and excellent storability. It has been clarified that a base fabric satisfying all the properties can be provided.

The material of the coarse woven fabric used in the present invention is not particularly limited, and examples thereof include polyamide fibers such as nylon 6.6, nylon 6 and nylon 4.6, polyester fibers typified by polyalkylene terephthalate, and paraphenylene terephthalate. Use aramid fibers such as amides and copolymers with aromatic ethers, wholly aromatic polyester fibers, polyolefin fibers such as ultra high molecular weight polyethylene, and sulfone fibers such as paraphenylene sulfone and polysulfone. You can These fibers can be used as spun fibers, but from the viewpoint of effectively utilizing the strength of each single fiber, it is preferable to use them as filament fibers.

[0011] Fibers used as coarse fabrics of the present invention, from the surface to compensate for the strong tear film, it is necessary tensile strength of 7 g / denier or more, more preferably 9
It is preferably g / denier or more.

The fineness of the yarn used as the coarse woven fabric is not particularly limited, but the total fineness is preferably in the range of 200 to 2000 denier, the finest is preferable, and the single yarn fineness is preferably 1 to 10. Within the range of denier, it is preferable that it is as thin as possible in terms of softening the texture.

Coarse weave of the present invention

[0013] The coarse fabric of the present invention, Ru is essential der those with eyes case of 6~20mm.
That is, when the mesh size is less than 6 mm, a dense woven fabric is obtained and the tear strength is large, but it is not preferable in terms of weight reduction.
When the mesh size exceeds 20 mm, the weight is reduced, but the tear strength is small, which is not preferable.

The above-mentioned mesh means the space portion of the woven fabric composed of the warp yarns and the weft yarns constituting the woven fabric, and is represented by half the outer peripheral length of the space portion.

On the other hand, the material of the film laminated with the coarse woven fabric is not particularly limited, but polyethylene terephthalate, polypropylene, polyethylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polycarbonate, nylon 6, aromatic polyimide. , Polyurethane, polyphenylene sulfide, tetrafluoroethylene, trifluoroethylene, etc. can be used. The film in the present invention is laminated on one side or both sides of the coarse woven fabric, but in terms of integration of the laminate,
Those laminated on both sides are preferable.

The thickness of such a film is preferably 100 μm or less, more preferably 70 μm or less.
When a film having a thickness of more than 100 μ is used, it has a hard texture due to its thickness, which is not preferable in terms of weight saving and storability. It is essential that the breaking elongation of such a film is 200 % or more . That is, at least the laminate
The breaking elongation of the film on the side in contact with the face is 200
% , The impact absorption effect at the time of face contact is increased.
You can do it . A film having a breaking elongation of less than 200% tends to have a large impact on the face when the airbag is inflated. The film when laminated on both sides of the coarse woven fabric may be the same film on both sides, the material,
It may have different breaking elongation and thickness.

The lamination of the coarse woven fabric and the film may be any of bonding with an adhesive, bonding with an extrusion laminate in which the film is manufactured with a molten polymer and simultaneously with the coarse woven fabric, and the coarse woven fabric and the film, and The method of joining the films may be either full surface adhesion or partial adhesion.

[0018]

The present invention will be further described with reference to the following examples. In addition, the physical-property value in an Example was measured by the following method.

(1) The weight per unit area of the unit weight JIS L-1096 was measured. (2) Thickness Measured according to JIS L-1096. (3) Tear strength Measured according to JIS L-1096 (single tongue method). (4) Stiffness Measured according to JIS L-1096 (45 ° cantilever method). Example 1 As a coarse woven fabric, a total weaving degree of 840 denier, 136
Filament, 9.3 g strength / denier nylon 6.
A 6-filament yarn was used to adjust the weaving density of the warp and the weft to prepare a plain weave having a mesh of 8 mm .

Then, scouring, drying and setting were carried out by a usual method. On the other hand, a polyethylene terephthalate film having a breaking elongation of 300% and a thickness of 50 μm was prepared as a film. Then, 7 g / m ² of a polyurethane-based adhesive was applied to one surface of the film, both surfaces of the coarse woven fabric were laminated with the film, and an airbag was prepared using this laminate sheet.

Table 1 shows the evaluation results of the airbag .

[0022]

Example 2 A coarse woven fabric having a total fineness of 1000 denier, 66
6 filament, strength 22 g / denier Kevlar (DuPont, east Rekebura manufactured by aramid fiber) using a filament yarn, eye case has created a flat fabric of 8mm.

The woven fabric had a breaking elongation of 300% and a thickness of 50 μm.
A polyethylene terephthalate film was prepared in the same manner as in Example 1 to prepare a laminate sheet, which was used to prepare an airbag. Table 1 shows the evaluation results of the airbag.

Example 3 In Example 1 , a polyethylene terephthalate film having a breaking elongation of 300% and a thickness of 50 μ was used as one film to be laminated, and a breaking elongation of 500 was used as the other film.
%, An airbag was produced in the same manner as in Example 1 except that a polyurethane film having a thickness of 50 μ was used. Table 1 shows the evaluation results of the airbag.

Comparative Example 1 840 denier, 136 filaments, strength 9.3 g /
Using denier nylon 6.6 filament yarn,
A plain fabric having a density of 25 warps / inch each was prepared, and then scouring, drying and setting were carried out by a usual method. Then, the fabric was coated with chloroprene rubber at 110 g / m ² using a knife coat. An air bag was created using this base cloth. Table 1 shows the evaluation results of the airbag.

Comparative Example 2 An air bag made of a polyethylene terephthalate film alone having a breaking elongation of 300% and a thickness of 125 μ was prepared.
Table 1 shows the evaluation results of the airbag.

[0028]

[Table 1] As is clear from Table 1, the conventional chloroprene rubber-coated airbag shown in Comparative Example 1 had a large areal weight, a large thickness, and was hard, and thus was poor in storability. Further, the air bag of the single film shown in Comparative Example 2 had a defect that the tear strength was extremely small. The products of Examples 1 to 3 , which are the products of the present invention, were excellent in storability because they were lightweight, thin, and had a soft texture, and also had the tear strength required for an airbag.

Among the products of the present invention, the mesh size is 6 mm to 20 mm.
Then, an airbag having a film thickness of 100 μm or less and a breaking elongation of 200% or more was particularly preferable in terms of storability.

[0030]

As described above, according to the present invention, since a lightweight, thin, and soft texture can be obtained, it is excellent in storability and the steering wheel and the instrument panel can be downsized.

Continuation of the front page (56) Reference JP-A-2-63949 (JP, A) JP-A-2-163149 (JP, A) JP-A2-155639 (JP, A) JP-A-1-317847 (JP , A) Japanese Patent Laid-Open No. 2-31965 (JP, A) Japanese Patent Laid-Open No. 50-113935 (JP, A) Japanese Patent Laid-Open No. 4-5144 (JP, A) Japanese Utility Model Laid-Open No. 54-51749 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60R 21/16 B32B 27/02

Claims (2)

(57) [Claims] 1. A coarse woven fabric having a mesh size of 6 to 20 mm , which is formed by using a woven yarn having a fiber strength of 7 g / denier or more as a base fabric constituting an airbag, and a breaking elongation of 200.
An air bag characterized by using a laminate formed by joining a film having a content of at least% . Wherein said film has an air bag according to claim 1, wherein the der Rukoto less thickness 100 microns.