JPH07186856A - Base cloth for air bag - Google Patents

Abstract

PURPOSE:To provide a base cloth which is light and has a soft air feeling and the stable degree of ventilation, being fundamental characteristics as a base cloth for an air bag, as mechanical characteristics needed as an air bag are held. CONSTITUTION:A base cloth for an air bag is a polyester fiber fabric and the degree (y) of ventilation of the fabric has an under-mentioned relation with a fluid pressure (x). In 0.1<=x<=0.5, y<=-90x<2>+170x, wherein (y) is the degree of ventilation (cc/cm<2>/sec), and (x) is a fluid pressure (kgf/cm<2>).

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 in the event of a vehicle collision, and more particularly, to an air bag which is lightweight, has a soft texture, and has excellent storability. It's about bags.

[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 an automobile, an airbag receives a collision impact and a sensor is activated to generate high temperature and high pressure gas, and the gas causes the airbag to inflate instantaneously, the occupant's face at the time of collision, It is intended to protect the forehead.

Conventionally, an air bag is made of a plain woven fabric using nylon 66 or nylon 6 filament yarn of 300 to 1000 denier and chloroprene or chlorosulfonated olefin for improving heat resistance, flame retardancy and air barrier property. It was made by applying an elastomer resin such as a synthetic rubber such as silicone, cutting the laminated base cloth, and sewing it into a bag.

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 adopted. With respect to the base cloth, in the case of a chloroprene elastomer resin, it is usually 90 to 120 on the surface of the base cloth.
It was not preferable because it was applied g / m ² and was considerably heavy, the texture was rough and hard, and when the air bag was inflated, it could be scratched if it came into contact with the face. In addition, there is a problem that it is difficult to fold in terms of storability.
Further, in the case of a silicone elastomer resin having more excellent heat resistance and cold resistance as compared with the chloroprene elastomer resin, the coating amount is 40 to 60 g / m ² and the weight is reduced,
Although it has improved considerably in terms of texture and storability, it is still not enough. On the other hand, as compared with polyamide fiber woven fabrics such as nylon 66 and nylon 6, uncoated airbags made of polyester fiber woven fabric, which are superior in dimensional stability and have a small change in air permeability due to changes in humidity, are being studied. There is a problem in mechanical properties and low air permeability, and a satisfactory airbag base fabric has not been obtained.

[0005]

SUMMARY OF THE INVENTION In view of the drawbacks of the conventional airbags, an object of the present invention is to keep the mechanical properties required for the airbags, to be lightweight and soft to the touch, and to provide a base material for the airbags. It is intended to provide a base fabric having stable air permeability, which is a basic characteristic of the fabric.

[0006]

In order to achieve the above object, the present invention has the following constitution. That is, the airbag base fabric of the present invention is a polyester fiber woven fabric, and the air permeability (y) of the woven fabric has a relationship with the fluid pressure (x) represented by the following general formula 1. It is a thing.

(General Formula 1) When 0.1 ≦ x ≦ 0.5, y ≦ −90x ² +170
x [y: Air permeability (cc / cm ² / sec), x: Fluid pressure (kgf / c)
m ² )]

[0008]

According to the present invention, the woven fabric constituting the airbag base fabric is a polyester fiber woven fabric, and based on the relationship between the air permeability (y) and the fluid pressure (x) of the woven fabric, the actual airbag The air permeability under the gas pressure, that is, the fluid pressure, which is said to be applied at the time of expansion and expansion, is limited, and the present invention cannot be achieved without this.

The polyester fibers constituting the airbag base fabric in the present invention include homopolyesters such as polyethylene terephthalate and polybutylene terephthalate, and isophthalic acid and 5-sodium sulfoisophthalic acid as an acid component constituting the repeating unit of polyester. Alternatively, it is a continuous fiber made of polyester copolymerized with an aliphatic dicarboxylic acid such as adipic acid. Such continuous fibers may contain various additives which are usually used for improving the productivity or the characteristics in the manufacturing process or the processing process of the raw yarn. For example, heat stability, antioxidant, light stabilizer, leveling agent, antistatic agent, plasticizer, thickener,
A pigment, a flame retardant, etc. can be contained. on the other hand,
The structure of the woven fabric that constitutes the airbag base fabric is not particularly limited, but a flat structure is preferable because it is easy to obtain low air permeability in the woven fabric structure and excellent in mechanical strength.

The air permeability (y) of the woven fabric referred to in the present invention is
Is (general formula 1): y ≦ −90x ² +170 in 0.1 ≦ x ≦ 0.5
x [y: Air permeability (cc / cm ² / sec), x: Fluid pressure (kgf / c)
m ² )], the relationship of y ≦ y ₁ is satisfied in the region of 0.1 ≦ x ≦ 0.5. Here, the fluid pressure (x) means the air pressure applied to the woven fabric, which is 0.1
≦ x ≦ 0.5 means a region corresponding to the gas pressure which is supposed to be applied when the airbag is inflated and deployed. y> -90
When x ² + 170x, air permeability, which is a basic property as a base fabric for airbags, is high, which is not preferable in terms of air barrier properties. In addition, it takes too much time to inflate and deploy as an airbag, and a sufficient burst pressure cannot be obtained, which is not preferable because the function as an airbag is lost.
It is essential that ≦ y ₁ .

Further, the air permeability (y) of the woven fabric is (general formula 2): 0.1 ≦ x ≦ 0.5, −10x ² + 30x ≦ y ≦ −90x ² + 170x [y: Air permeability (cc / cm ² / sec), x: Fluid pressure (kgf / c
m ² )], in the region of 0.1 ≦ x ≦ 0.5, the relationship of −10x ² + 30x ≦ y ≦ −90x ² + 170x has a light weight, a softness, and a weaving property. sex,
It is more preferable in terms of productivity.

Further, usually, the single yarn fineness of the woven fabric is 5 denier or less, and the total fineness is 200 to 600 denier. A woven fabric satisfying the above general formula and having a basis weight of 250 g / m ² or less and a thickness of 0.4 mm
Hereinafter, a woven fabric having a flat structure having a tensile strength of 160 kgf / 3 cm or more, a breaking elongation of 20% or more, and a tear strength of 10 kgf or more is preferably used in terms of mechanical properties, flexibility and storability. Further, if necessary, chemical processing such as resin processing and physical processing such as calendar processing may be performed.

On the other hand, as a method for producing these base cloths, for example, a filament yarn of polyethylene terephthalate fiber having a total fineness of 420 denier, 144 filaments, a tensile strength of 8.9 g / denier and a breaking elongation of 15% is used, and water is used. Using a jet weaving machine, the weaving density of the warp and the weft is adjusted to be 52 yarns / inch, and a plain weave fabric is obtained. At this time, if the weaving density of the warp and the weft is different or the difference in tension is too large, the desired air permeability may not be obtained. Next, the woven fabric is scoured at 90 ° C. for 30 seconds with an open soaper without applying tension as much as possible, and dried at 130 ° C. for 3 minutes with a non-touch dryer to obtain a woven fabric having warp and weft woven densities of 52 to 53 yarns / inch. can get. Then, with a pin tenter type heat treatment machine, 4 at 180 ° C so that the weaving density is maintained at 52 to 53 yarns / inch.
By heat setting for 5 seconds, it is possible to obtain an air bag base fabric having an air permeability that satisfies the general formula of the present invention.

[0014]

EXAMPLES The present invention will be described in more detail with reference to examples. The stiffness, air permeability, storability, burst pressure, and inflation time of the airbag in the examples were measured by the following methods.

Stiffness: JIS L 1096,
It was determined by the 6.19.1A method (45 ° cantilever method).

Air permeability: Using a laminar flow pipe air permeability measuring instrument, a fluid (air) was flowed at a predetermined pressure, and the air flow rate (cc / cm ² / sec) passing therethrough was measured.

Storability: A 10 cm × 20 cm woven fabric is bent into a tubular shape, and the bulkiness when a load of 15 g is applied is measured. As a standard product, silicone rubber coated product (4
The relative value when the bulkiness of 5 g / m ² coated product is 100 is shown.

Burst pressure: Burst pressure was measured using an airbag dynamic burst tester.

Inflation and deployment time: Burst time was measured using an airbag dynamic burst tester. Examples 1 and 2 Total fineness 420 denier, 192 filaments, strength 9.
Using a filament yarn of polyethylene terephthalate fiber of 1 g / denier, elongation 15% and total fineness 420 denier, 144 filament, strength 8.9 g / denier, elongation 15%, weaving warp and weft with a water jet loom. The densities were adjusted to be 51 fibers / inch, and a woven fabric having a flat structure was obtained. Next, the woven fabric was scoured with an open soaper at 90 ° C. for 30 seconds and then dried with a non-touch dryer at 130 ° C. for 3 minutes to obtain a woven fabric having a warp and weft woven density of 52 yarns / inch. Then, it was heat-set for 45 seconds at 180 ° C. by a pin tenter type heat treatment machine so as to maintain the weave density of 52 yarns / inch to obtain an air bag base fabric. This material has a permeability of 0.2 at fluid pressure.
was kg / under cm ² at 15.5cc / cm ² / sec and 13.6cc / cm ² / sec. The properties of the air bag base fabric thus obtained are shown in Table 1. The air bag base fabric of the present invention has low air permeability and storability as an air bag, and has good burst pressure and inflation time.

Comparative Examples 1 and 2 Total fineness 420 denier, 192 filaments, strength 9.
Using a filament yarn of polyethylene terephthalate fiber of 1 g / denier, elongation 15% and total fineness 420 denier, 144 filament, strength 8.9 g / denier, elongation 15%, weaving warp and weft with a water jet loom. A woven fabric having a flat structure having a density of 45 fibers / inch was obtained. Then, the woven fabric was scoured at 90 ° C. for 30 seconds with an open soaper, and then squeezed with a non-touch dryer for 130 seconds.
It was dried at 0 ° C. for 3 minutes to obtain a woven fabric having a warp and weft woven density of 46 yarns / inch. After that, with a pin tenter type heat treatment machine, 180 ° C so that the weave density is maintained at 46 yarns / inch.
And heat set for 45 seconds to obtain a base fabric for an airbag. The air permeability of this product was 45.2 cc / cm ² / sec and 41.5 cc / c under a fluid pressure of 0.2 kg / cm ^2.
It was m ² / sec [Comparative Examples 1 and 2].

The characteristics of the air bag base fabric thus obtained were evaluated in the same manner as in Example 1 and shown in Table 1. As can be seen from the above, the airbag base fabrics of Comparative Examples 1 and 2 were excellent in storability as an airbag, but had high air permeability and had a problem of inflating and expanding time, and thus functioned as an airbag. Was not obtained.

Examples 3 and 4 Total fineness 420 denier, 288 filaments, strength 9.
Using a filament yarn of polyethylene terephthalate fiber having a denier of 3 g / denier, an elongation of 16% and a total fineness of 420 denier, 192 filaments, a strength of 8.9 g / denier and an elongation of 15%, with a rapier weaving machine, weaving density of warp and weft A woven fabric having a flat design of 54 yarns / inch was obtained. Next, the woven fabric was scoured at 80 ° C. for 15 minutes with a Jigger dyeing machine and then dried at 130 ° C. for 3 minutes with a non-touch dryer to obtain a woven fabric having a warp and weft density of 55 yarns / inch. Then, a pin tenter type heat treatment machine was used to heat set at 190 ° C. for 45 seconds so as to maintain the weave density of 55 yarns / inch, to obtain an airbag base fabric. After drying and heat setting, a base fabric for an airbag was obtained.

The air permeability of this product is such that the fluid pressure is 0.3 k.
was g / under cm ² at 15.3cc / cm ² / sec and 17.1cc / cm ² / sec.

The characteristics of the air bag base fabric thus obtained were evaluated in the same manner as in Example 1 and shown in Table 1. The air bag base fabric of the present invention has low air permeability and storability as an air bag, and has good burst pressure and inflation time.

Comparative Examples 3 and 4 Total fineness 420 denier, 144 filaments, strength 8.
Using a filament yarn of polyethylene terephthalate fiber of 9 g / denier and an elongation of 15%, with a rapier weaving machine,
A woven fabric having a flat design in which the weaving densities of the warp and the weft were both 45 / inch was obtained. Then, the fabric is subjected to 80 with a Jigger dyeing machine.
After scouring for 15 minutes at ℃, 1 with a non-touch dryer
Dry at 30 ℃ for 3 minutes, weaving density of warp and weft is 46 yarns /
I got an inch fabric. Then, using a pin tenter type heat treatment machine, the weave density should be maintained at 19 yarns per inch.
Heat set at 0 ° C. for 45 seconds. Then, using a comma coater, silicone rubber coating was performed so that the coating amount was 45 g, followed by vulcanization at 180 ° C. for 2 minutes to obtain a base fabric for an airbag. Air permeability of this product, 0.02 cc fluid pressure under 0.3kg / cm ² / cm ² /
It was sec [Comparative Example 3]. Using a comma coater, chloroprene rubber coating was performed so that the coating amount was 110 g, and vulcanization treatment was performed at 180 ° C. for 2 minutes to obtain an air bag base fabric.

The air permeability of this product is such that the fluid pressure is 0.3 k.
It was 0.01 cc / cm ² / sec under g / cm ² [Comparative Example 4]. The properties of the thus obtained air bag base fabric were evaluated in the same manner as in Example 1 and shown in Table 1.
As can be seen from Table 1, the air bag base fabrics of Comparative Examples 3 and 4 had low air permeability and good burst pressure and inflation time, but were poor in storability and flexibility as air bags. Also, the coating process was complicated and there was a problem in terms of production.

Example 5 Total fineness 315 denier, 72 filaments, strength 9.0
Using a filament yarn of polyethylene terephthalate fiber having a g / denier of 16% and an elongation of 16%, an air jet weaving machine was used to obtain a woven fabric having a flat design in which the weaving densities of the warp and the weft were both 65 yarns / inch. Then, the woven fabric was scoured, dried and heat set in the same manner as in Example 1 to obtain a base fabric for an airbag. The air permeability of this product was 11.3 cc / cm ² / sec under a fluid pressure of 0.2 kg / cm ² . The properties of the thus obtained air bag base fabric were evaluated in the same manner as in Example 1 and shown in Table 1. As shown in Table 1, the air bag base fabric of the present invention provided low air permeability and storability as an air bag, and had good burst pressure and inflation time.

Comparative Example 5 Total fineness 315 denier, 72 filaments, strength 9.0
Using a filament yarn of polyethylene terephthalate fiber having a g / denier and an elongation of 16%, an air jet weaving machine was used to obtain a woven fabric having a flat design in which the weaving density of both warp and weft was 50 yarns / inch. Then, the woven fabric was scoured, dried and heat set in the same manner as in Example 1 to obtain a base fabric for an airbag. The air permeability of this product was 48.3 cc / cm ² / sec under a fluid pressure of 0.2 kg / cm ² . The properties of the thus obtained air bag base fabric were evaluated in the same manner as in Example 1 and shown in Table 1. As can be seen from Table 1, the airbag base fabric of Comparative Example 5 was excellent in storability as an airbag, but had high air permeability and had a problem in inflating and expanding time, and thus functions as an airbag. Was not obtained.

[0029]

[Table 1]

[0030]

According to the present invention, it is possible to provide an air bag which is flexible, lightweight and excellent in storability while maintaining the mechanical strength required as an air bag, and compared with the conventional air bag. As a result, it is possible to provide an inexpensive airbag, and it is possible to promote the occupant protection system using the airbag.

[Brief description of drawings]

FIG. 1 shows the relationship between air permeability (y) and fluid pressure (x).

[Explanation of symbols]

^{_{1: y 1 = -90x 2 +}} 170x 2: y 2 = -10x 2 + 30x

Claims (2)

[Claims] 1. A non-coated base fabric for an airbag made of a polyester fiber woven fabric, wherein the woven fabric has an air permeability (y).
Is a fluid pressure (x) and has a relationship represented by the following general formula 1. (General Formula 1) When 0.1 ≦ x ≦ 0.5, y ≦ −90x ² +170
x [y: Air permeability (cc / cm ² / sec), x: Fluid pressure (kgf / c)
m ² )] 2. The air bag base fabric according to claim 1, wherein the air permeability (y) of the woven fabric and the fluid pressure (x) have a relationship represented by the following general formula 2. (General formula 2) In 0.1 ≦ x ≦ 0.5, −10x ² + 30x ≦ y ≦ −90x ² + 170x [y: Air permeability (cc / cm ² / sec), x: Fluid pressure (kgf / c)
m ² )]