JPH10273002A - Backing fabric for air bag, and air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide backing fabrics for air bag and an air bag of excellent low gas permeability and the like while holding mechanical characteristic by laminating a film on the surface of a fiber base material having specific gas permeability when air regulated into specific pressure is let flow. SOLUTION: As for a fiber base material, a material of low gas permeability in which a passing air quantity at letting flow air regulated into the pressure of 0.2 kg/cm<2> less than 100 cc/cm<2> /sec, favorably less than 50 cc/cm<2> /sec, is used, and an extremely thin film is laminated on the surface. Concretely, plain weave fabric of polyamide fiber, polyester fiber, or the like is excellent in mechanical characteristic in particular, and it is favorable from a viewpoint of thin fabric. Meanwhile, material of the film laminated on the fiber base material is not particularly limited, but polyethyleneterephthalate exhibits the effect in particular from a viewpoint of mechanical characteristic. As for a method laminating the film on the fiber base material, a metal roll, a plastic roll, a press system, or the like is properly used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag for absorbing and protecting an occupant's impact during a vehicle collision, and more particularly, to an airbag having low air permeability, light weight, flexibility and storage. The present invention relates to an airbag base fabric and an airbag.

[0002]

2. Description of the Related Art Conventionally, 400 to 1000 airbags have been used.
An elastomer resin such as synthetic rubber such as chloroprene, chlorosulfonated olefin, or silicone is applied to a plain fabric using denier nylon 66 or nylon 6 filament yarn to improve heat resistance, flame retardancy, air barrier properties, etc. Then, the laminated base cloth was cut and sewn into a bag.

[0003] However, when these elastomer resins are applied and laminated on one side of a base cloth, a coating method such as knife coating, roll coating, and reverse coating is generally employed. In the case of chloroprene elastomer resin, 90 to 120
g / m ^{2 is} applied, the thickness is increased, and there is a problem in that the package volume is increased also in terms of storability. Also, compared to chloroprene elastomer resin,
In the case of a silicone elastomer resin having better heat resistance and cold resistance, the coating amount was 40 to 60 g / m2, the weight was reduced, and the storability was considerably improved. However, the lamination has a complicated process and has a problem in productivity.

On the other hand, there is a strong demand for an airbag base fabric to have an improved storage capacity for the airbag base fabric in order to reduce the price and reduce the size of the module cover, and an airbag using a non-coated base fabric has attracted attention. Have been. As a corresponding technology, a high-density non-coated airbag made of a polyamide fiber fabric such as nylon 66 or nylon 6 and a polyester fiber fabric has been studied. For example, Japanese Unexamined Patent Publication (Kokai) No. 4-2835 proposes an uncoated low-permeability woven fabric, which is more economical than a coated product but does not have sufficient low-permeability. On the other hand, the present inventors filed Japanese Patent Application Laid-Open No.
No. 13136 proposes an airbag composed of a laminate of a coarse woven fabric and a film.
Although the low air permeability has been improved, the mechanical properties are hardly sufficient, and a satisfactory airbag base fabric has not been obtained.

[0005]

SUMMARY OF THE INVENTION In view of the drawbacks of the conventional airbag, an object of the present invention is to provide low air permeability, light weight, flexibility and storage while maintaining the mechanical characteristics of the airbag. An object of the present invention is to provide an excellent airbag fabric and an airbag.

[0006]

The present invention has the following configuration to achieve the above object. That is, the air bag base cloth of the present invention, 0.2 kg / cm the amount of air through which flowed by adjusting the pressure of ² 100 cc / cm ² /
A film is laminated on the surface of a fiber base material having an air permeability of sec. or less.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention has been studied diligently to provide an airbag base fabric having excellent low air permeability without applying a coating process. By laminating the film, low air permeability while maintaining the mechanical properties as an airbag,
It has been found that it is possible to provide a base fabric for an airbag, which is excellent in lightness, flexibility and storability.

According to the study by the present inventor, such an effect is obtained by laminating the film on the surface of the fiber base material in a non-adhered state, laminating through an adhesive layer, or partially applying an adhesive. Excellent effects can be exerted regardless of whether they are laminated and further laminated.

The fiber base material of the present invention includes nylon 6.6, nylon 6, nylon 12, nylon 4
6, a copolymer of nylon 6 and nylon 6.6, a polyamide fiber obtained by copolymerizing nylon with polyalkylene glycol, dicarboxylic acid, amine, etc., a homopolyester such as polyethylene terephthalate, polybutylene terephthalate, or a repeating unit of polyester Fiber, copolymerized with aliphatic dicarboxylic acid such as isophthalic acid, 5-sodium sulfoisophthalic acid or adipic acid, aramid fiber represented by copolymerization with paraphenylene terephthalamide and aromatic ether, rayon High-density woven fabrics, knitted fabrics and non-woven fabrics composed of fibers, sulfone-based ultrahigh molecular weight polyethylene fibers, and polymer array fibers having a sea-island structure mainly composed of the above synthetic fibers can be used. As a form of such a fiber substrate, a woven fabric is more preferable. Further, as the fabric structure, plain weave, twill weave, satin weave and their modified weaves, such as multi-axial weaves, are used. Among these, plain fabrics are particularly excellent in mechanical properties and plain fabrics are preferable from the ground-thin aspect. . Further, among the woven fabrics, the airbag having a plain woven fabric made of polyamide fiber and polyester fiber has excellent characteristics.
In addition, such a fiber may contain various additives that are usually used for improving productivity or characteristics in a production process or a processing process of a raw yarn. For example, heat stabilizers, antioxidants, light stabilizers, leveling agents, antistatic agents, plasticizers, thickeners,
Pigments, flame retardants and the like can be added.

[0010] As such a fiber base material of the present invention, 0.2
The amount of air passing when adjusted to a pressure of kg / cm ² is 100 cc / cm ² / sec. or less, more preferably 50 cc / cm ² / sec.
/ Cm ² / sec. Or less, it is possible to provide the above-described excellent fabric for an airbag simply by laminating an extremely thin film.

Further, the above-mentioned woven fabric simultaneously satisfies the following requirements from the viewpoint of the mechanical properties required for an airbag and the lightness of the fiber base material of the present invention. Can be demonstrated.

(A) Weight W (g / m ² ) W ≦ 250 (b) Thickness Th (mm) Th ≦ 0.35 (c) Tensile Strength S (N / cm) S ≧ 500 (d) Break Elongation Degree E (%) E ≧ 15 (e) Tearing strength Te (N) Te ≧ 100 (f) Cover factor (Cf) 1000 ≦ Cf ≦ 2500 Here, the cover factor (Cf) is the total warp fineness of D1, Assuming that the warp density is N1, the weft total fineness is D2, and the weft density is N2, Cf = (D1) ^{1 /} 2.times.N1 + (D2) ^{1 /} 2.times.N2. In terms of sex,
Preferably 1000 to 2500, more preferably 150
0 to 2000. As the loom, a water jet loom, an air jet loom, or a rapier loom can be used as appropriate.

The total fineness and single yarn fineness constituting the woven fabric are not particularly limited, but the total fineness is preferably 100 to 100%.
600 denier, more preferably 100 to 500 denier, single yarn fineness is preferably 0.5 to 8 denier, more preferably 2 to 6 denier, particularly preferably 3 to 6 denier.
Denier is used. The strength of these fibers is preferably 6.5 g / d or more.

On the other hand, the material of the film to be laminated on the fiber base material 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, ethylene trifluoride and the like can be used. Among these, polyethylene terephthalate is particularly effective in terms of mechanical properties. These films may be unstretched films, uniaxially or biaxially stretched films, or a combination thereof. In general, compared to unstretched films, stretched films are preferred to use stretched films because of their excellent tensile strength, burst strength, and tear propagation resistance.However, since these characteristics are related to the combination with the fiber base material, It may be used as appropriate. Of course, such a film, for example, a multi-layer film laminate of various combinations such as a laminate of at least two types selected from an unstretched film, a uniaxially stretched film and a biaxially stretched film can be used. Such a film is clearly distinguished from a coating film.

It is essential that the thickness of such a film is 10 microns or less, preferably 5 microns or less, more preferably 1 micron or less. When a film having a thickness of more than 10 microns is used, the texture becomes hard due to the thickness, and this is not preferable in terms of storability. In addition, such a film is laminated in a non-adhered state on the surface of the fiber base material, that is, simply laminated (not adhered).
Alone, or may be laminated via an adhesive layer, or may be laminated by partially applying an adhesive, or may be further laminated.

As a method of laminating a film on a fiber base material, a metal roll, a plastic roll, a press method, or the like is appropriately used. The airbag base fabric obtained by laminating such a film on a fiber base material can be appropriately used for a driver seat airbag, a passenger seat airbag, a rear seat airbag, and a side airbag.

In the above airbag, the reinforcing cloth used for the inflator mounting port or the vent hole or the member for regulating the bag deployment shape is preferably the same base material as the fiber base material. Is advantageous and preferred. Further, when sewing the airbag, it is preferable to sew one or more such airbag base fabrics formed by punching or fusing, and sew the periphery thereof. An airbag composed of only double seams is preferred.

The feature of the airbag fabric of the present invention is that excellent low air permeability, light weight, flexibility and storage properties can be imparted while maintaining mechanical properties. That is,
The base fabric obtained according to the present invention can provide an airbag having excellent mechanical properties and low air permeability, light weight, flexibility, and storability without coating.

[0019]

Next, the present invention will be described in more detail by way of examples. The characteristics of the airbag fabric in the examples were measured by the following methods.

Weight: JIS L6328 (5.
3.4 method).

Thickness: JIS L6328 (5.
3.3 method).

Tensile strength: JIS L6328 (5.
3.5 method).

Elongation at break: JIS L6328 (5.
3.5 method).

Tear strength: JIS L6328 (5.
3.6 method).

Air permeability: Using a laminar flow tube air permeability meter, a fluid (air) was adjusted to a pressure of 0.2 kg / cm ² and allowed to flow, and the air flow rate (cc / cm ² / sec) passing at that time was measured. It was measured.

Softness: JIS L1096 (6.1
9.1A method).

Storability: The airbag bag was bent into a predetermined shape, and the fold height when 98 N was pressed was measured. As standard products, silicone rubber coated products (4
(5 g / m ² coated product) as a relative value when the bulkiness is set to 100.

Example 1 Nylon 6.6 having a total fineness of 420 deniers, 72 filaments, a strength of 9.5 g / denier and an elongation of 22.5%
Using a filament yarn composed of fibers, a plain woven fabric having a warp and weft density of 45 / inch was obtained in a water jet loom. This fabric has an air permeability of 45 cc / cm ² /
sec., the basis weight was 175 g / m ² , and the thickness was 0.26 mm. On the other hand, the film has a melting point of 260 ° C. and a thickness of 1.5
A biaxially stretched film made of polyethylene terephthalate having a melting point of 150 ° C. and a thickness of 1.0 μm was used as an adhesive layer.
Laminated with a metal roll heated to 5 ° C,
An airbag base fabric was obtained. Thereafter, two circular cloths of 725 mm in diameter are cut out from the base cloth for airbag by a punching method, and three circular reinforcing cloths of 200 mm in diameter made of only plain cloth are laminated at the center of one circular cloth. And 110m in diameter
The upper and lower threads on the 145 mm and 175 mm lines were sewn with a sewing thread composed of 420D / 1 × 3 of nylon 6.6 fibers, and the sewing machine was sewn by lockstitching. Further, a circular reinforcing cloth having a diameter of 75 mm made of the same cloth is applied to a position opposite to the center by a distance of 255 mm in the bias direction.
420D of nylon 6.6 fiber for both upper and lower thread on mm line
The sewing machine was sewn with lock stitches using a sewing thread composed of / 1 × 3, and two vent holes having holes with a diameter of 40 mm were provided. Next, the reinforcing fabric side of the present circular fabric is set outside, and the other circular fabric is overlapped with the other circular fabric by shifting the longitudinal axis by 45 degrees, and a circular shape having a diameter of 700 mm and 710 mm is made of nylon 6.6 fiber of 1260D / After sewing the sewing machine by double chain stitching with the sewing thread composed of No. 1, the bag body is turned over and 60L
A driver's airbag with a large capacity was produced.

The properties of the airbag fabric and the airbag thus obtained were evaluated and are shown in Table 1. The airbag of the present invention had the mechanical properties and low air permeability required for the airbag, and was excellent in lightness and storability.

COMPARATIVE EXAMPLES 1 AND 2 Using the same filament yarn as in Example 1, in a water jet loom, weave density of both warp and weft is 45 yarns / inch, and a plain woven fabric having an air permeability of 45 cc / cm ² / sec. Was. On the other hand, a biaxially stretched film made of polyethylene terephthalate having a melting point of 260 ° C. and a thickness of 35 μm was used as a film, and a melting point of 150 ° C. and a thickness of 1.0 μm was used as an adhesive layer.
Lamination was performed using a micron polyethylene film with a metal roll heated to 175 ° C. to obtain a base fabric for an airbag.

As Comparative Example 2, a plain woven fabric having the same weaving density of 45 warps / inch was obtained in a water jet loom using the same filament yarn as in Example 1. Next, the woven fabric was scoured and dried by a usual method, and then heat-set at 180 ° C. for 25 seconds. Thereafter, the woven fabric was coated with a methyl vinyl silicone rubber using a comma coater so that the coating amount became 45 g / m ² , dried at 120 ° C., and then vulcanized at 180 ° C. for 3 minutes. Then, a base fabric for an airbag was obtained. Next, these airbag base fabrics were also subjected to 60% as in Example 1.
An L-capacity airbag for a driver's seat was produced.

The characteristics of the airbag fabric and the airbag thus obtained were evaluated in the same manner as in Example 1.
It was shown to. Although the airbags of Comparative Examples 1 and 2 were excellent in low air permeability, they were inferior in lightness and storability, and the airbag of Comparative Example 2 had a complicated processing step and had a problem in terms of productivity. Was. Example 2 Using a filament yarn composed of nylon 6 fiber having a total fineness of 315 denier, 72 filaments, a strength of 9.3 g / denier, and an elongation of 23.1%, the woven densities of the warp and the weft are both set in a water jet loom. A 54 / inch plain weave was obtained. Next, scouring and drying are carried out by a conventional method.
A 0 ° C. heat set was applied. This one has air permeability of 25cc
/ Cm ² / sec., Weight 189 g / m ² , thickness 0.27 mm
Met. On the other hand, the film as a melting point 265 ° C., using a biaxially oriented film made of polyethylene terephthalate having a thickness of 0.85 microns, bonded urethane adhesive on one surface of the film was 5 g / m ² coating, based on the air bag Got the cloth. Thereafter, one body cloth and two side cloths were melted and cut to produce a passenger airbag having a capacity of 120 L.

The properties of the airbag fabric and the airbag thus obtained were evaluated in the same manner as in Example 1.
It was shown to. The airbag of the present invention had the mechanical properties and low air permeability required for the airbag, and was excellent in lightness and storability.

Comparative Examples 3 and 4 The same plain woven fabric as in Example 2 was used, and a film having a melting point of 2 was used.
Using a biaxially stretched film made of polyethylene terephthalate having a thickness of 65 ° C. and a thickness of 15.5 microns, a urethane-based adhesive was applied to one surface of the film at 5 g / m ² and laminated to obtain a base fabric for an airbag [Comparison] Example 3].

On the other hand, the same plain woven fabric as
One side was subjected to pressure compression at a pressure of 35 tons and a speed of 15 m / min between a metal roll having a flat surface heated to 0 ° C. and a plastic roll at room temperature to obtain a base fabric for an airbag [Comparative Example 4]. . Thereafter, a passenger airbag having a capacity of 120 L was produced in the same manner as in Example 2.

The characteristics of the airbag fabric and the airbag thus obtained were evaluated in the same manner as in Example 1.
It was shown to. The airbag of Comparative Example 3 was excellent in low air permeability, but was inferior in lightness and storability, and the airbag of Comparative Example 4 was coarse and hard and slightly inferior in tear strength.

Example 3 Total denier 420 denier, 144 filaments, strength 8.
Using a filament yarn composed of polyethylene terephthalate fiber having a density of 8 g / denier and an elongation of 18%, a woven fabric having a flat structure in which both warp and weft yarns had a weave density of 46 / inch was obtained by a rapier loom. Next, the woven fabric was scoured and dried by a conventional method, and then heat-set at 180 ° C. for 25 seconds. This had an air permeability of 43 cc / cm ² / sec., A basis weight of 189 g / m ² and a thickness of 0.26 mm. On the other hand, as a film, melting point 2
An unstretched film made of polyethylene terephthalate having a temperature of 65 ° C. and a thickness of 0.95 μm was used, and the films were simply laminated in a superposed state of a flat structure to obtain an airbag base fabric. Thereafter, one body cloth and two side cloths were melted and cut to produce a 15-L side airbag. The properties of the airbag fabric and the airbag thus obtained were evaluated in the same manner as in Example 1, and are shown in Table 1. The airbag of the present invention had the mechanical properties and low air permeability required for the airbag, and was excellent in lightness and storability.

Comparative Example 5 An unstretched film made of polyethylene terephthalate having a melting point of 265 ° C. and a thickness of 20 μm was used on the same plain fabric as in Example 3, and the film was simply laminated with a flat structure and air-laid. A base fabric for a bag was obtained. Thereafter, one body cloth and two side cloths were melted and cut to produce a 15-L side airbag.

The properties of the airbag fabric and the airbag thus obtained were evaluated in the same manner as in Example 1.
It was shown to. The airbag of Comparative Example 5 was insufficient in lightness and storage.

[0040]

[Table 1]

[0041]

According to the present invention, while maintaining the mechanical properties required for an airbag, low air permeability, light weight,
It can provide airbags with excellent flexibility and storability, and can provide cheaper airbags than conventional coated or calendered products, and promote the spread of occupant protection systems using airbags. Can be done.

Claims (20)

[Claims] 1. A film is laminated on the surface of a fiber base material having an air permeability of 100 cc / cm ² / sec. Or less when flowing at an adjusted pressure of 0.2 kg / cm ² . A base fabric for an airbag, comprising: 2. The airbag base fabric according to claim 1, wherein the air permeability is 50 cc / cm ² / sec. Or less. 3. The airbag fabric according to claim 1, wherein said film has a thickness of 5 microns or less. 4. The airbag fabric according to claim 1, wherein said film has a thickness of 1 micron or less. 5. The airbag fabric according to claim 1, wherein the film is laminated on the fiber base material in a non-adhered state. 6. The airbag fabric according to claim 1, wherein the film is laminated on the fiber base material via an adhesive layer. 7. The airbag base fabric according to claim 6, wherein the adhesive is partially applied. 8. The airbag fabric according to claim 1, wherein the film is laminated on the fiber base material by lamination. 9. The airbag fabric according to claim 1, wherein the film is a laminate of a plurality of films. 10. The fiber substrate according to claim 1, wherein the fiber substrate is a woven fabric.
The base fabric for an airbag according to any one of 5, 6, and 8. 11. The airbag base fabric according to claim 10, wherein the woven fabric simultaneously satisfies the following requirements (a) to (f). (A) Weight W (g / m ² ) W ≦ 250 (b) Thickness Th (mm) Th ≦ 0.35 (c) Tensile strength S (N / cm) S ≧ 500 (d) Elongation at break E ( %) E ≧ 15 (e) Tear strength Te (N) Te ≧ 100 (f) Cover factor (Cf) 1000 ≦ Cf ≦ 2500 12. The fabric according to claim 10, wherein the fabric has a cover factor of 1500 to 2000.
The base fabric for an airbag according to the above. 13. The woven fabric according to claim 10, wherein the woven fabric has a total fineness of 100 to 500 denier.
The base fabric for an airbag according to any one of claims 12 to 13. 14. The fabric according to claim 10, wherein the woven fabric is composed of fibers having a single yarn fineness of 0.5 to 7 denier.
4. The base fabric for an airbag according to any one of 3. 15. The airbag base fabric according to claim 10, wherein the fabric is a 1 × 1 plain fabric. 16. The air according to claim 1, wherein the fiber base is made of at least one kind of fiber selected from polyamide fibers and polyester fibers. Base fabric for bags. 17. An airbag, wherein the airbag base fabric according to claim 1 is formed with the film side inside. 18. The airbag according to claim 17, wherein in the airbag, the reinforcing cloth or the member that regulates the deployment shape of the airbag is the same base as the fibrous base. 19. The airbag according to claim 1, wherein one or a plurality of airbag deployment-shaped pieces formed by punching or fusing the base fabric for the airbag are sewn. 19. The airbag according to 17 or 18. 20. The airbag according to claim 19, wherein the sewing is performed only by single or double joining.