JP2002309462A - Base cloth for airbag and airbag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base cloth for an airbag having light weight, soft texture and low air-permeability as a basic characteristic of a base cloth for airbag while keeping the necessary mechanical properties as airbag and provide an airbag produced by using the base cloth. SOLUTION: The base cloth for an airbag is made of a woven fabric of a synthetic fiber free from resin finishing and calendering treatment. The woven fabric has a cover factor of 1,800-2,150 and is composed of a synthetic fiber multifilament yarn consisting of single filaments each having a flat cross-section and an aspect ratio of 1.5-6.0. The air permeability (y) (cc/cm<2> /sec) of the woven fabric and the fluid pressure (x) (kPa) satisfy the following general formula 1: y<0.51x in the range of 4.9<=x<=49. The airbag of the present invention is produced by using the base cloth.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag which absorbs the impact of an occupant in the event of a vehicle collision and protects it.
The present invention relates to a low-ventilation airbag having excellent storage properties.

[0002]

2. Description of the Related Art In recent years, various airbags have been developed in order to ensure the safety of occupants in the event of an accident of various transportation means, especially automobiles. I'm advancing. Driver airbags and passenger airbags in particular are becoming almost 100% fitted to passenger cars, and airbags are limited due to diversifying designs of steering wheels and instrument panels. It is also desired to be compactly stored in the space.

Conventionally, airbags have a size of 300 to 1000 d.
Elastomer resin such as synthetic rubber such as chloroprene, chlorosulfonated olefin, and silicone to improve heat resistance, flame retardancy, air barrier properties, etc. on plain fabrics using tex nylon 6.6 or nylon 6 filament yarn Was applied, and the base fabric laminated was cut and sewn into a bag.

[0004] However, when these elastomer resins are applied and laminated, a coating method such as knife coating, roll coating, and reverse coating is generally employed. Usually, in the case of a chloroprene elastomer resin, 90 to 120 g / m ^{2 is} applied to the surface of the base fabric, so that there is a problem in that the thickness is increased and the package volume is increased also in terms of storability. In the case of a silicone elastomer resin having more excellent heat resistance and cold resistance than a chloroprene elastomer resin, the application amount is 40 to 60 g / m ² and the weight is reduced. Is enough
Another problem is that it is difficult to fold the bag when storing it in a package. Further, the steps of applying and laminating the elastomer are complicated, and there is a problem in productivity. Further, in order to solve such a problem, Japanese Patent Application Laid-Open No. Hei 4-201650 discloses a single yarn deformation degree of 1.5 to 1.5.
A coating fabric using a modified cross-section yarn of 7.0 has been proposed, but no proposal regarding a woven fabric has been made, such as no description of a cover factor.

In recent years, attention has been paid to airbags using non-coated base fabrics in order to solve such problems. As a corresponding technology, a high-density non-coated airbag made of a polyamide fiber fabric such as nylon 6.6 or nylon 6 or a polyester fiber fabric is being studied.

For example, Japanese Unexamined Patent Publication (Kokai) No. 7-186856 discloses that in a non-coated airbag base fabric made of a polyester fiber fabric, the air permeability (y [cc / cm ²
/ Sec]) and the fluid pressure (x [kg / cm ² ]) are 0.1 ≦
When x ≦ 0.5, a base fabric for an airbag satisfying y ≦ −90x ² + 170x has been proposed.
No. 86857 discloses a non-coated base fabric for an airbag made of a polyamide fiber woven fabric.
(y [cc / cm ² / sec]) and fluid pressure (x [kg / c
m ² ]) is 0.05 ≦ x ≦ 0.50 and y ≦ 175
x has been proposed. In order to achieve the air permeability, for example, 470 dtex, a 72-filament round cross-section yarn is used, and the density is 53 to 54 / 2.5.
It is stated that a 4 cm fabric must be used.

However, in any of the fabrics, the fabric itself is hard, and there is a problem in terms of compactness of bag storage, and in fact, it is not satisfactory in terms of air permeability.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the conventional airbag, the present invention is lightweight and soft while maintaining the mechanical properties required for an airbag. It is an object of the present invention to provide a low-permeability airbag base fabric and an airbag which are the basic characteristics of the airbag.

[0009]

The present invention employs the following means in order to solve the above-mentioned problems. That is, in the airbag base fabric of the present invention, in an airbag made of synthetic fiber woven fabric that is not subjected to resin processing or calendering processing, the woven fabric has a flat cross section of a single yarn having an aspect ratio of 1.5 to 6.0. The cover factor composed of synthetic multifilament yarn is 180
0-2150, and the air permeability (y) of the woven fabric has a relationship represented by the following general formula 1 with the fluid pressure (x). (General formula 1) 4.9 ≦ x ≦ 49, y <0.51x [y: air permeability (cc / cm ² / sec), x: fluid pressure
(kPa)] The airbag of the present invention is characterized by being constructed using such an airbag base fabric.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has been made to solve the above-mentioned problems, that is, while maintaining the mechanical properties required for an airbag, it is lightweight and has a soft feel, and has the basic characteristics of a basic fabric for an airbag. About airbag base cloth of breathability,
After careful examination, the cover factor composed of a specific flat cross section synthetic fiber multifilament yarn was 1800 to 2
Using a specific woven fabric of 150, and further controlling the relationship between the bag internal pressure applied during the inflation and deployment of the airbag, the air permeability of the woven fabric constituting the airbag base fabric, and the fluid pressure so as to be within a specific range. The present inventors have sought to solve the above-mentioned problems at once.

In the present invention, the synthetic fiber multifilament yarn constituting the airbag base fabric is nylon 6
6, nylon 6, nylon 12, nylon 4.6, copolymerization of nylon 6 and nylon 6.6, polyamide fiber obtained by copolymerizing nylon 6 with polyalkylene glycol, dicarboxylic acid or amine, polyethylene terephthalate, polybutylene terephthalate, etc. Homopolyester, a polyester fiber obtained by copolymerizing an aliphatic dicarboxylic acid such as isophthalic acid, 5-sodium sulfoisophthalic acid or adipic acid with an acid component constituting a repeating unit of polyester, paraphenylene terephthalamide and aromatic ether Aramid fibers, rayon fibers, polysulfone-based fibers, ultrahigh molecular weight polyethylene fibers, and polymer array fibers mainly having the above-mentioned synthetic fibers and having an islands-in-the-sea structure can be used. Of these, polyamide fibers and polyethylene terephthalate fibers are preferred, and nylon 6
6, polyamide fibers such as nylon 6 are preferable from the viewpoint of impact resistance. Such fibers may contain various additives that are commonly used for improving productivity or properties in the production process or processing process of the raw yarn. For example, a heat stabilizer, an antioxidant, a light stabilizer, a leveling agent, an antistatic agent, a plasticizer, a thickener, a pigment, a flame retardant and the like can be contained.

[0012] Such a synthetic fiber multifilament yarn is
It is essential that the cross section of the single yarn has an aspect ratio of 1.5 to 6.0.

A synthetic multifilament yarn having a ratio of the major axis to the minor axis, that is, an aspect ratio of 1.5 to 6.0, preferably 3.0 to 4.0 is used. By using such a flat cross-section yarn having an aspect ratio of 1.5 to 6.0, the gap between the single yarns in the multifilament constituting the woven fabric as shown in FIG. Since the number of the woven fabrics is smaller than that of the woven fabric using the round cross-section yarn of 1.0, a woven fabric with low air permeability is easily obtained.

If the aspect ratio is less than 1.5, the effect of low air permeability cannot be sufficiently obtained, while if it exceeds 6.0, the effect is low.
High strength required for airbag yarn, usually 7.0 cN
It is difficult to obtain a high-strength yarn of / dtex or more with a good yield, and the effect of low air permeability is also unnecessary because it is saturated.

The flat cross-section yarn is usually elliptical, but may have a shape other than elliptical as long as it satisfies the aspect ratio of 1.5 to 6.0. For example, a symmetrical type such as a rectangle, a rhombus, and a cocoon type may be used, of course, or an asymmetrical type or a combination thereof. Further, the above-described basic type has a projection, a dent, or a partially hollow portion. You may.

[0016] The structure of the woven fabric is plain weave, twill weave,
A satin weave and those having a texture such as a variable weave and a multiaxial weave are used. Among them, a plain weave is particularly preferably used because of its excellent mechanical properties. The cover factor of the woven fabric is required to be 1800 to 2150 from the viewpoint of low air permeability and bag storability, and more preferably 1900 to 2050. When the cover factor is smaller than 1800, although the bag storage property is preferable, the mechanical properties are reduced and the air permeability is increased. Further, when the cover factor is larger than 2150, it is preferable in terms of low air permeability and mechanical properties,
The woven fabric becomes hard and inferior in flexibility, causing a problem in bag storage.

Here, the cover factor is the total length of the warp yarn.
Fineness is D₁(Dtex) , Warp yarn density to N₁(Book / 2.
54 cm) and the total weft yarn fineness is D._Two(Dtex) , Yo
The yarn density is N_Two(Book / 2.54cm) Then, (D₁
* 0.9 )^1/2× N₁+ (D _Two* 0.9 )^1/2× N_Two
It is represented by

As the loom used in the weaving process, a water jet room, an air jet room, a rapier room, and the like are used. As the weaving conditions, it is preferable to set the warp yarn tension to 100 to 200 g / thread. The warp yarn tension greatly affects the crimp rate of the warp yarn. When the warp yarn tension is lower than 100 g / line, the crimp rate of the warp yarn increases, and the fabric flexibility in the warp yarn direction is good. The degree is undesirably high. If the warp yarn tension is greater than 200 g / strand,
Although the crimp ratio of the warp yarn is small and the air permeability is good, it is not preferable because the flexibility of the woven fabric in the warp yarn direction is impaired and the weaving stability is poor.

Further, the air permeability (y) of the woven fabric referred to in the present invention.
4.9 ≦ x ≦ 49, y <0.51x [y: air permeability (cc / cm ² / sec), x: fluid pressure (k
Pa))].

Here, the fluid pressure (x) refers to the air pressure applied to the fabric, and 4.9 ≦ x ≦ 49 indicates a region corresponding to the gas pressure assumed to be applied when the airbag is inflated and deployed. means. When y ≧ 0.51x, the air permeability, which is a basic characteristic of the airbag base fabric, is high, and when the airbag is deployed, the internal pressure of the bag does not increase and it takes too much time to deploy.

The air permeability (y) of the woven fabric is as follows: (general formula 2): 4.9 ≦ x ≦ 49, y <0.36x [y: air permeability (cc / cm ² / sec), x: Fluid pressure (k
Pa.)], And more preferably (General Formula 3): 4.9 ≦ x ≦ 49, y <0.25x [y: air permeability (cc / cm ² / sec); x: fluid pressure (k
Pa))].

The flat cross-section yarn of the present invention preferably has a single yarn fineness of 1 to 7 dtex. Single yarn fineness of 1 to
By setting the dtex to 7 dtex, the gap between the single yarns constituting the yarn is reduced, the air permeability is reduced, and the flexibility of the yarn is increased. Therefore, when the bag is folded, the bent portion of the folded portion is easily crushed. It also improves bag storage compactness. If the single yarn fineness is smaller than 1 dtex, a problem occurs in terms of yarn-making properties, while if it is larger than 7 dtex, problems occur in terms of low air permeability and compactness in bag storage.

With respect to the bag storage property, the airbag is obtained by folding the airbag base fabric into a predetermined shape,
Since it is stored in a package of a certain size, the foldability of the base cloth and the volume of the bag after storage are important. Therefore, in the woven fabric of the present invention, it is preferable that the thickness of the bag at the time of a load of 10 N in the storage test is 40 mm or less and the thickness of the bag at the time of releasing the load is 50 mm or less.

Here, the storage test was measured based on the following method.

Two circular cloths having a diameter of 725 mm are cut out from the airbag base cloth by a punching method, and three circular reinforcing cloths having a diameter of 200 mm made of the same cloth are laminated at the center of one circular cloth. 110mm, 145mm, 175m in diameter
470 dte of nylon 6.6 fiber for both upper and lower thread on m line
The sewing machine is sewn with a lockstitch using a sewing thread composed of x / 1 × 3, a hole having a diameter of 90 mm is provided, and the hole is used as an inflator attachment port. Further, 255 m from the center in the bias direction
At the position of m, one circular reinforcing cloth of 75 mm in diameter made of the same base cloth is applied in opposition, and the line of 50 mm and 60 mm in diameter is 470 dtex / nylon 6.6 fiber of both nylon yarns.
The sewing machine is sewn with lock stitches using a sewing thread composed of 1 × 3, and two vent holes provided with holes having a diameter of 40 mm are provided.

Next, the reinforcing fabric side of the circular fabric is turned out,
The other circular fabric is overlapped with its longitudinal axis shifted by 45 degrees, and the upper and lower threads are made of nylon 6.6 fibers with a sewing thread composed of 1400 dtex / 1 on a circumference of 700 mm and 710 mm by double chain stitching. After the sewing machine is sewn, the bag is turned over to create an airbag having a capacity of 60 L.

As shown in FIG. 3, the air bag is first set from the left and right so that the size of the bag is 150 × 150 mm.
After folding the bellows four times, the bellows are folded four times from above and below, and a load of 10 N is applied to the folded bag as shown in FIG. 4, and the thickness of the bag at that time is measured. Thereafter, the thickness of the bag after removing the load is measured.

The thickness of the bag under a load of 10 N is 40 mm
If it is larger, the volume of the folded bag is large, so it is difficult to store the bag compactly. Further, if the thickness of the bag after the release of the load is larger than 50 mm, the resilience after folding the bag is large, which is not preferable in terms of bag storage workability.

The total fineness of the synthetic multifilament yarn constituting the woven fabric is 200 to 700 dtex, preferably 300 to 500 dtex, and the original yarn strength is 7.0 cN / dt.
Ex or more is preferably used from the viewpoint of mechanical properties, flexibility, and storability required as an airbag base fabric. The woven fabric has a tear strength of 100 N or more, a basis weight of 250 g / m ² or less, a thickness of 0.35 mm or less, a tensile strength of 400 N / cm or more, and a breaking elongation of 20%.
Those described above are preferably used in view of the mechanical properties, flexibility, and storability required for the airbag base fabric.

The airbag base fabric of the present invention can be used for various airbags such as a driver's seat, a passenger's seat, a rear seat, a side, and an inflatable curtain.

The features of the airbag base fabric and the airbag of the present invention are that gas leakage during bag deployment is small while maintaining mechanical properties.

[0032]

Next, the present invention will be described in more detail by way of examples.

Various evaluations in the examples were performed according to the following methods. -Weight (weight): Determined according to JIS L1096 (6.4.2 method). -Thickness: determined according to JIS L1096 (6.5 method). -Tensile strength: JIS L1096 (6.12.1A)
Method), the fabric width is 3cm, the tension grip distance 15c
m, the breaking strength when pulled at a pulling speed of 200 mm / min was measured.・ Elongation at break: JIS L1096 (6.12.1A)
Method), the fabric width is 3cm, the tension grip distance 15c
m, and the elongation at break when pulled at a tensile speed of 200 mm / min. -Tear strength: JIS L1096 (6.15.2A-
2), the tear strength when pulled at a tensile speed of 200 mm / min was determined. -Air permeability: 4.9, 9.8, 19.
The pressure was adjusted to 629.4, 39.2, and 49 kPa, and the air flow was measured. The relationship between the fluid pressure and the air permeability was determined by the least square method.・ Storability test: As shown in FIG. 3, an airbag having a capacity of 60 L was set so that the bag became 150 × 150 mm.
First of all, from the left and right, after folding into bellows four times, from above and below, into four bellows, into the folded bag,
As shown in FIG. 4, a load of 10 N was applied, and the thickness of the bag at that time was measured. Thereafter, the thickness of the bag after removing the load was measured. -Bag deployment test: Measure the maximum internal pressure of the bag when deployed with an electric ignition type inflator of 200 kPa output, and when the maximum internal pressure of the bag is 20 kPa or more,
The case where it was lower than 0 kPa was evaluated as x.

Example 1 Total fineness: 470 dtex, 96 filaments, strength: 8.3
Using a flat cross-section filament yarn of nylon 6.6 fiber with cN / dtex, elongation of 22% and aspect ratio of 3.6, the weaving density of both warp and weft becomes 48 / 2.54 cm in a water jet loom. To obtain a flat-woven fabric. Next, the woven fabric is subjected to 8
Scouring at 5 ° C for 30 seconds, 13
It was dried at 0 ° C. for 3 minutes, and then heat-set at 180 ° C. for 30 seconds using a pin tenter type heat treatment machine so as to maintain a weave density of 49 yarns / 2.54 cm to obtain a base fabric for an air bag. Table 1 shows the characteristics of the airbag fabric thus obtained.

The airbag fabric of the present invention has low air permeability and storability as an airbag, and also has good bag deployability.

Comparative Example 1 Total fineness: 470 dtex, 96 filaments, strength: 8.3
In a water jet loom, the weaving density of both warp yarns and weft yarns is 48 yarns / 2.54 cm using a round cross-section filament yarn of nylon 6.6 fiber with cN / dtex, elongation 22%, and aspect ratio 1.0. To obtain a flat-woven fabric. Next, the woven fabric is subjected to 85 with an open soaper.
Scour at 30 ° C for 30 seconds, 130
C. for 3 minutes, and then heat-set at 180.degree. C. for 30 seconds with a pin tenter type heat treatment machine so as to maintain a weave density of 49 yarns / 2.54 cm to obtain a base fabric for an airbag. Table 1 shows the characteristics of the airbag fabric thus obtained.

The characteristics of the airbag base fabric thus obtained were evaluated in the same manner as in Example 1, and are shown in Table 1. As can be seen from the above, the airbag base fabric of Comparative Example 1 is:
The air permeability was high and the bag deployability was poor.

Comparative Example 2 Total fineness: 470 dtex, 96 filaments, strength: 8.3
Using a flat cross-section filament yarn of nylon 6.6 fiber having a cN / dtex, elongation of 22%, and an aspect ratio of 3.6, the weaving density of both warp and weft becomes 45 yarns / 2.54 cm in a water jet loom. To obtain a flat-woven fabric. Next, the woven fabric is subjected to 8
Scouring at 5 ° C for 30 seconds, 13
It was dried at 0 ° C. for 3 minutes, and then heat-set at 180 ° C. for 30 seconds with a pin tenter type heat treatment machine so as to maintain a weave density of 46 yarns / 2.54 cm to obtain a base fabric for an air bag. Table 1 shows the characteristics of the airbag fabric thus obtained.

The characteristics of the airbag base fabric thus obtained were evaluated in the same manner as in Example 1, and are shown in Table 1. As can be seen, the airbag fabric of Comparative Example 2
The air permeability was high and the bag deployability was poor.

Comparative Example 3 Total fineness: 470 dtex, 96 filaments, strength: 8.3
Using a flat cross-section filament yarn of nylon 6.6 fiber with cN / dtex, elongation 22% and aspect ratio 3.6, the weaving density of both warp and weft becomes 56 yarns / 2.54 cm in a water jet loom. To obtain a flat-woven fabric. Next, the woven fabric is subjected to 8
Scouring at 5 ° C for 30 seconds, 13
It was dried at 0 ° C. for 3 minutes, and then heat-set at 180 ° C. for 30 seconds with a pin tenter type heat treatment machine so as to maintain a weave density of 57 yarns / 2.54 cm to obtain a base fabric for an air bag. Table 1 shows the characteristics of the airbag fabric thus obtained.

The characteristics of the airbag base fabric thus obtained were evaluated in the same manner as in Example 1, and are shown in Table 1. As can be seen from the above, the airbag base fabric of Comparative Example 3 is:
Although air permeability is low and bag deployment is excellent,
Bag storage was inferior.

Example 2 Total fineness 470 dtex, 120 filaments, strength 7.
Using a flat cross-section filament yarn of nylon 6.6 fiber with 6cN / dtex, elongation 23% and aspect ratio 2.3,
In the water jet loom, the warp weave density is 51
Book / 2.54cm, weft weave density 49 / 2.54c
m to obtain a woven fabric having a flat structure. Next, the woven fabric was treated with a pin tenter type heat treatment machine so that the weaving density of the warp was 51 / 2.54 cm and the weft was 49 / 2.54 cm.
Was maintained at 180 ° C. for 30 seconds so as to maintain the air bag base fabric. Table 1 shows the characteristics of the airbag fabric thus obtained. The airbag base fabric of the present invention has low air permeability and storage properties as an airbag, and also has good bag deployability.

Comparative Example 4 Total fineness 470 dtex, 120 filaments, strength 7.
Using a nylon 6.6 round filament yarn of 6cN / dtex, elongation of 23% and aspect ratio of 1.0 in a water jet loom, the weaving density of the warp is 51 / 2.54cm, the weaving density of the weft. Is 49 / 2.54cm
To obtain a flat-woven fabric. Next, the woven fabric was heat-set at 180 ° C. for 30 seconds using a pin tenter type heat treatment machine so that the weaving density of the warp was 51 / 2.54 cm and the weft was 49 / 2.54 cm. I got Table 1 shows the characteristics of the airbag fabric thus obtained.

The characteristics of the airbag base fabric thus obtained were evaluated in the same manner as in Example 1, and are shown in Table 1. As can be seen from the above, the airbag base fabric of Comparative Example 3 is:
The air permeability was high and the bag deployability was poor.

Example 3 Total fineness 400 dtex, 108 filaments, strength 8.
Using a flat cross section filament yarn of nylon 6.6 fiber of 4 cN / dtex, elongation 22%, aspect ratio 1.9,
In the rapier room, the weaving density of both the warp and the weft was adjusted to be 56 yarns / 2.54 cm to obtain a flat-woven fabric. Next, the woven fabric was subjected to a pin tenter type heat treatment machine so that the weaving density of both the warp and the weft was 56 / 2.5.
It was heat-set at 160 ° C. for 30 seconds so as to hold 4 cm to obtain an airbag base fabric. Table 1 shows the characteristics of the airbag fabric thus obtained. The airbag base fabric of the present invention has low air permeability and storage properties as an airbag, and also has good bag deployability.

Comparative Example 5 Total fineness 400 dtex, 108 filaments, strength 8.
Using a circular cross section filament yarn of nylon 6.6 fiber of 4 cN / dtex, elongation of 22% and aspect ratio of 1.0, weaving density of both warp and weft is 5 in rapier room.
Adjustment was made to 6 fibers / 2.54 cm to obtain a woven fabric having a flat structure. Next, the woven fabric was subjected to a pin tenter type heat treatment machine so that the weaving density of both the warp and the weft was 56 / 2.5.
Heat setting was performed at 180 ° C. for 30 seconds so as to maintain 4 cm to obtain an airbag base fabric. Table 1 shows the characteristics of the airbag fabric thus obtained.

The characteristics of the airbag base fabric thus obtained were evaluated in the same manner as in Example 1, and are shown in Table 1. As can be seen from the above, the airbag base fabric of Comparative Example 4 is:
The air permeability was high and the bag deployability was poor.

[0048]

[Table 1]

[0049]

According to the present invention, it is possible to provide an airbag having low air permeability, flexibility, light weight, and excellent storability while maintaining the required mechanical strength as an airbag, and the occupant protection by the airbag. The system can be promoted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a flat section yarn (470 dtex-96).
F, a sectional view showing a fiber shape of a cross section of a woven fabric using an aspect ratio of 3.6).

FIG. 2 shows a round cross-section yarn (470 dtex-96).
F, an aspect ratio of 1.0). FIG.

FIG. 3 is a schematic view showing a method of folding an airbag in a storage test.

FIG. 4 is a schematic diagram showing a method of measuring the thickness of a bag when a load is applied to the airbag during a storage test.

[Explanation of symbols]

 1: Top view of 60L capacity airbag 2: Folding direction 3: Top view of airbag folded from left and right 4: Top view of airbag folded from top and bottom 5: Side view of airbag folded from top and bottom, left and right 6: Load 7: Thickness of airbag when load is applied

Continuation of the front page F term (reference) 3D054 CC26 FF03 FF14 4L048 AA20 AA24 AA37 AB07 BA01 BA02 CA11 CA15 DA25 EA01 EB05

Claims (8)

[Claims] 1. An airbag comprising a synthetic fiber woven fabric which is not resin-processed or calendered, wherein the woven fabric is made of a synthetic fiber multifilament yarn having a single yarn having a flat cross section having an aspect ratio of 1.5 to 6.0. An airbag base comprising a woven fabric having a cover factor of 1800 to 2150, and having a permeability (y) and a fluid pressure (x) represented by the following general formula (1). cloth. (General formula 1) 4.9 ≦ x ≦ 49, y <0.51x [y: air permeability (cc / cm ² / sec), x: fluid pressure
(kPa)] 2. The airbag base fabric according to claim 1, wherein the air permeability (y) of the woven fabric has a relationship represented by the following general formula 2 with the fluid pressure (x). (General Formula 2) 4.9 ≦ x ≦ 49, y <0.36x [y: air permeability (cc / cm ² / sec), x: fluid pressure
(kPa)] 3. The airbag base fabric according to claim 1, wherein the air permeability (y) of the woven fabric has a relationship represented by the following general formula 3 with the fluid pressure (x). (General Formula 3) 4.9 ≦ x ≦ 49, y <0.25x [y: air permeability (cc / cm ² / sec), x: fluid pressure
(kPa)] 4. The woven fabric is a woven fabric composed of a multifilament yarn of a synthetic fiber having a single yarn having a flat cross section with an aspect ratio of 3.0 to 4.0, and a cover factor of 1900 to 1900. The airbag base fabric according to any one of claims 1 to 3, wherein the fabric is a woven fabric of 2050. 5. The airbag base fabric according to claim 1, wherein the woven fabric is composed of a synthetic fiber multifilament yarn having a single yarn fineness of 1 to 7 dtex. 6. An airbag produced using the woven fabric, wherein the bag thickness at a load of 10 N in a storage test specified in the text is 40 mm or less, and the bag thickness at the time of release of the load. The airbag base fabric according to any one of claims 1 to 5, wherein is less than or equal to 50 mm. 7. The airbag base fabric according to claim 1, wherein the synthetic fiber multifilament yarn is a polyamide multifilament yarn. 8. An airbag comprising the airbag base fabric according to any one of claims 1 to 7.