JP2001114051A - Foundation cloth for air bag and air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foundation cloth for air bags and an air bag which are excellent in an unfolding property while the mechanical property as air bag is maintained. SOLUTION: The foundation cloth for air bags of this invention is characterized by the fact that the tensile ductility in the directions of warp and weft is 10 to 30% under the tensile force of 260 N/cm in the case of the foundation cloth for air bags, which is made of synthetic fiber fabric. Further, the air bag of this invention is characterized by the fact that the air bag is formed of such a foundation cloth for air gags.

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 at the time of a vehicle collision, and more particularly to an airbag fabric excellent in bag deployability. is there.

[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. Normally, an airbag is deployed to absorb an occupant's impact at the time of a vehicle collision. However, from an ideal impact absorption, a more excellent bag deployability is required.

Conventionally, plain fabrics made of nylon 6.6 or nylon 6 filament yarn of 340 to 1120 decitex have been used for airbags, and chloroprene, chlorsulfone, It has been made by applying and laminating an elastomer resin such as synthetic rubber such as olefinated olefin or silicone, cutting the laminated base fabric, and sewing it on 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.

In recent years, attention has been paid to an airbag using a non-coated base fabric formed by high-density weaving 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. US Patent 5
Japanese Patent No. 704402 proposes to define the rate of change in air permeability when the base fabric is pulled with a tension of 150 pounds / in (260 N / cm) simultaneously in the warp and weft directions. There is no description about the difference in tensile elongation between the warp direction and the weft direction at the time. Therefore, no proposal has been made on the difference in tensile elongation for the equal deployment of the airbag, and the actual situation is that it is not sufficient in terms of deployability.

[0006]

SUMMARY OF THE INVENTION In view of the background of the conventional airbag, the present invention provides an airbag base fabric and an airbag excellent in deployability while maintaining the mechanical characteristics of the airbag. It is something you want to do.

[0007]

In order to solve the above-mentioned problems, the present invention employs the following safety measures. That is, the base fabric for an airbag of the present invention is a base fabric for an airbag made of a synthetic fiber fabric at 260 N / c.
A base fabric for an airbag, wherein the tensile elongation in the warp direction and the weft direction under a tension of m are both 10 to 30%. Further, the airbag of the present invention is characterized by being constituted by such an airbag base fabric.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a base fabric for an airbag which is excellent in deployability while maintaining the above-mentioned objects, that is, not only strong, low air permeability, and storability, but also mechanical retention as an airbag. After intensive studies, focusing on the difference in tensile elongation between the warp yarn direction and the weft yarn direction when the airbag is inflated and deployed, the warp yarn direction and the weft yarn direction under a tension of 260 N / cm were examined. Tensile elongation 10-3
At 0%, they have sought to solve the above-mentioned problems at once.

As the synthetic fiber base fabric in the present invention, for example, nylon 6.6, nylon 6, nylon 12,
Repeating unit of nylon 4.6, copolymer of nylon 6 and nylon 6.6, polyamide fiber obtained by copolymerizing nylon 6 with polyalkylene glycol, dicarboxylic acid or amine, homopolyester such as polyethylene terephthalate, polybutylene terephthalate, or polyester 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 aramid fiber represented by copolymerization with paraphenylene terephthalamide and aromatic ether Synthetic fiber fabrics composed of rayon fiber, polysulfone fiber, ultrahigh molecular weight polyethylene fiber, and polymer array fiber having a sea-island structure mainly composed of the above synthetic fiber are used. Among these, polyamide fibers and polyethylene terephthalate fibers are preferably used, and nylon 6.6 and nylon 6 are more preferably used from the viewpoint of impact resistance. Such fibers include various additives commonly used for improving the productivity or properties in the production and processing steps of the yarn, such as heat stabilizers, antioxidants, light stabilizers, leveling agents, and antistatic agents. Agents, plasticizers, thickeners, pigments, flame retardants and the like.

The tensile elongation of the airbag fabric of the present invention under a tension of 260 N / cm in the warp and weft directions is as follows:
It is essential that it be in the range of 10 to 30% from the viewpoint of air permeability and shock absorption. If the tensile elongation under a tension of 260 N / cm is greater than 30%, the openings of the fabric occur, the air permeability increases, and when the airbag is deployed, gas leaks from the base fabric constituting the bag. There is fear. Also, 260N
When the tensile elongation under a tension of 10 cm / cm is small by 10%, the flexibility of the base cloth is lost, and it becomes difficult to efficiently receive an occupant's impact.

In order to set the tensile elongation under a tension of 260 N / cm in the range of 10 to 30%, a synthetic fiber having an original yarn elongation of 15 to 30%, for example, nylon 66 is used. Is preferred.

Among the base fabrics satisfying the tensile elongation, the difference between the tensile elongation in the warp direction and the weft direction under a tension of 260 N / cm is more preferably 0 to 7%. It is preferable to use a base cloth within the range. When the airbag is deployed, a tension of 260 N / cm is applied to the base cloth. Therefore, by reducing the difference in tensile elongation under a tension of 260 N / cm, the airbag is deployed isotropically. . When the airbag is deployed isotropically, the shape of the airbag becomes substantially circular, and the impact of the occupant can be absorbed in an ideal form. Further, it is preferable that the tensile elongation of the warp yarn is larger than the tensile elongation of the weft yarn from the viewpoint of weaving. 260N / c
If the tensile elongation difference at m is greater than 0 to 7%, when the airbag is deployed, the difference between the elongation in the warp direction and the elongation in the weft direction of the airbag becomes large, and the airbag becomes isotropic. As a result, it is difficult to efficiently receive the impact of the occupant.

The following method can be adopted as one method for keeping the tensile elongation in the range of 10 to 30%.

Conventional airbag fabrics generally have the same density of warp and weft yarns in order to make the tensile strength in the warp and weft directions equal. However, in the present invention, the warp yarn density and the weft yarn density are preferably different. When the warp yarn density and the weft yarn density are changed in this way, the difference in the crimp rate between the warp yarn and the weft yarn becomes smaller, and the difference in tensile elongation between the warp yarn direction and the weft yarn direction under a tension of 260 N / cm is obtained. It can be reduced to 0 to 7% or less. Also, the difference between the warp yarn density and the weft yarn density at that time is preferably 80% to 97%, more preferably one of the warp yarn density and the weft yarn density. Is preferably in the range of 85% to 95%. In addition, it is preferable to reduce the weft yarn density, particularly with respect to the warp yarn density, from the viewpoint of strength properties and weaving properties.

The total fineness and single fiber fineness of the yarns constituting the woven fabric are not particularly limited as long as they satisfy the mechanical properties and storability required for an airbag. The fineness of single fiber is preferably in the range of 0.55 to 7.7 decitex.

[0016] The structure of the woven fabric is plain weave, twill weave,
Fabrics such as satin weave and their variable weaves and multiaxial weaves are used
However, among these, the mechanical properties are particularly excellent
For this reason, plain fabrics are preferably used. Also heel
The cover factor of the woven fabric is 1500 to 2500
Is preferably within the range. That is, such a cover
If the factor is 1500 or more, the mechanical properties are sufficient
Thus, the air permeability can be kept low. In addition,
When the number of actors exceeds 2,500, the flexibility of the fabric can be secured.
Will not be able to. Here, the cover factor is the total warp
Fineness is D₁(Decitex), warp yarn density to N₁(Book/
2.54 cm), and the total weft yarn fineness is D_Two(Decitec
S), weft yarn density to N_Two(Book / 2.54 cm)
And (D₁)^1/2 × N₁+ (D_Two)^1/2× N_TwoRepresented by
You. Water weaving machines used in the weaving process include water
ー Jet loom, air jet loom, rapier
And the like are used.

Further, the fabric may be subjected to resin processing in order to further impart low air permeability and anti-raveling property. As the synthetic resin used for such resin processing, polyurethane-based, polyester-based, polyamide-based, acrylic-based,
A synthetic resin such as a silicone-based, polyethylene-based, styrene-butadiene-based, or nitrile-butadiene-based resin is used, but is not limited thereto. For such a synthetic resin, a solvent-based, water-based, water-dispersed resin liquid or a foamed resin liquid can be used as appropriate, but from the viewpoint of workability, an aqueous or water-dispersed resin liquid or a foamed resin liquid is preferably used. Can be On the other hand, the application amount of these synthetic resins is preferably 0.5 to 20 g / m ² . If the amount is too small, the effect of preventing fraying and the effect of low air permeability are small, and if it is more than necessary, the woven fabric becomes coarse and hard, resulting in poor storage properties, which is not preferable. In the present invention, it is more preferable that such a synthetic resin forms a film on the surface of the woven fabric.

Regarding the air permeability of the base fabric, JIS L-1
096 (6.27.1A method), the air permeability is preferably 0.5 cc / cm ² / sec or less. The air permeability is 0.5 cc / cm ² / se
If it is larger than c, when the airbag is deployed, gas leaks from the base fabric constituting the bag, and the deployment time tends to be longer. In addition, the gas is at a high temperature, and the occupant may be burned when the gas permeating the base fabric comes into contact with the face.

Also, the basis weight of the base fabric of the present invention is about 300 g /
m ² or less is preferable in terms of weight reduction, and the stiffness is about 10 in both the warp yarn direction and the weft yarn direction.
It is preferably 0 mm or less from the viewpoint of flexibility. Also,
When the base fabric has a tensile strength of at least about 300 N / cm, an elongation at break of at least about 15%, and a tear strength of at least about 50 N, the airbag can be stored and prevented from bursting when used as an airbag. Is preferred.

An airbag using such an airbag base fabric can be used for a driver seat airbag, a passenger seat airbag, a rear seat airbag, a side airbag, and the like.

[0021]

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.

Softness: JIS L1096
(6.19.1A method).

Tear strength: JIS L1096
(6.15.1A method).

Elongation at break: JIS L1096
(6.12.1A method).

Tensile strength: JIS L1096
(6.12.1A method).

Tensile elongation: JIS L1096
(6.12.1A method).

Air permeability: JIS L1096
(6.27.1A method).

Inflation and deployment characteristics: Deployed by an electric ignition type inflator, and after deployment as shown in FIG. 1, the length of the bag in the vertical and horizontal directions when the bag is viewed from the occupant side is measured. The length of the weft was expressed as a relative value. Example 1 A filament yarn composed of nylon 6.6 fiber having a total fineness of 470 dtex, 72 filaments, a strength of 8.8 g / decitex, and an elongation of 23.0% was used, and the vertical yarn density was measured in a water jet room. 54 pieces / 2.
A plain woven fabric having a width of 54 cm and a weft density of 50 yarns / 2.54 cm was obtained. Next, the woven fabric was immersed in a hot water bath containing 0.5 g / l of sodium alkylbenzene sulfonate and 0.5 g / l of soda ash for 3 minutes, dried at 130 ° C. for 3 minutes, and then dried at 180 ° C. for 1 minute. Heat heat set,
An airbag base fabric was obtained. Thereafter, two circular cloths having a diameter of 725 mm were cut from the airbag base cloth by a punching method, and three circular reinforcing cloths each having a diameter of 200 mm made of the same cloth were laminated at the center of one circular cloth. And diameter 110
mm, 145 mm, and 175 mm lines, the upper and lower threads were sewn with a sewing thread composed of 470 dtex / 1 × 3 of nylon 6.6 fiber, and the sewing machine was sewn by lock stitching. Further, a circular reinforcing cloth of the same base cloth having a diameter of 75 mm is applied to the opposite position at a position of 255 mm in the bias direction from the center, and nylon 6 is used for both the upper and lower threads on a line having a diameter of 50 mm and 60 mm.
-The sewing machine was sewn with lock stitches using a sewing thread composed of 470 dtex / 1x3 of 6 fibers, 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 and
Stacked with 5 ° shift, 700mm diameter, 710mm
The sewing machine was sewn on the circumference of the sewing machine by double chain stitching using a sewing thread composed of 1390 dtex / 1 of nylon 6.6 fiber for both upper and lower threads, and then the bag body was turned over to produce an airbag having a capacity of 60 L.

The properties of the airbag fabric and the airbag thus obtained were evaluated and the results are shown in Table 1. As is clear from Table 1, the development characteristics of the vertical and horizontal directions were well-balanced and excellent in expandability. Example 2 Using a filament yarn made of nylon 6.6 fiber having a total fineness of 470 dtex, 72 filaments, a strength of 8.8 g / decitex, and an elongation of 23.0%, a warp yarn density in a water jet room was used. 54 pieces / 2.
A plain woven fabric having a width of 54 cm and a weft density of 49 yarns / 2.54 cm was obtained. Next, 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. Next, an airbag having a capacity of 60 L was prepared from the airbag base fabric in the same manner as in Example 1.

The properties of the airbag fabric and the airbag thus obtained were evaluated and are shown in Table 1. As is clear from Table 1, the development characteristics of the vertical and horizontal directions were well-balanced and excellent in expandability. Example 3 Using a filament yarn made of nylon 6.6 fiber having a total fineness of 470 dtex, 72 filaments, a strength of 8.8 g / dtex, and an elongation of 23.0%, the warp yarn density was measured in a water jet room. 54 pieces / 2.
A plain fabric having 54 cm and a weft density of 46 yarns / 2.54 cm was obtained. Next, 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. Next, an airbag having a capacity of 60 L was prepared from the airbag base fabric in the same manner as in Example 1.

The properties of the airbag fabric and the airbag thus obtained were evaluated and the results are shown in Table 1. As is clear from Table 1, the development characteristics of the vertical and horizontal directions were well-balanced and excellent in expandability. Example 4 Using a filament yarn made of nylon 6.6 fiber having a total fineness of 350 dtex, 72 filaments, a strength of 8.6 g / decitex, and an elongation of 22.5%, the warp yarn density was measured in an air jet loom. 60 / 2.54
cm and a weft density of 55 yarns / 2.54 cm were obtained. Next, the woven fabric was scoured in the same manner as in Example 1,
After drying and heat setting, a base fabric for an airbag was obtained. Then
An airbag having a capacity of 60 L was prepared from the airbag base fabric in the same manner as in Example 1.

The properties of the airbag fabric and the airbag thus obtained were evaluated and the results are shown in Table 1. As is clear from Table 1, the development characteristics of the vertical and horizontal directions were well-balanced and excellent in expandability. Example 5 A filament yarn consisting of nylon 6.6 fiber having a total fineness of 470 dtex, 72 filaments, a strength of 8.8 g / decitex, and an elongation of 23.0% was used. Thread density is 54
Book / 2.54 cm plain woven fabric was obtained. Next, 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. Next, an airbag having a capacity of 60 L was prepared from the airbag base fabric in the same manner as in Example 1.

The properties of the airbag fabric and the airbag thus obtained were evaluated and the results are shown in Table 1. As is clear from Table 1, the development characteristics of the vertical and horizontal directions were well-balanced and excellent in expandability. Example 6 A filament yarn composed of nylon 6.6 fiber having a total fineness of 350 dtex, 72 filaments, a strength of 8.6 g / decitex, and an elongation of 22.5% was used. The yarn density is 60 threads /
A 2.54 cm plain weave was obtained. Next, 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. Next, an airbag having a capacity of 60 L was prepared from the airbag base fabric in the same manner as in Example 1.

The properties of the airbag fabric and the airbag thus obtained were evaluated and the results are shown in Table 1. As is clear from Table 1, the development characteristics of the vertical and horizontal directions were well-balanced and excellent in expandability.

[0036]

[Table 1]

[0037]

According to the present invention, it is possible to provide an airbag excellent in deployability while maintaining the necessary mechanical properties as a base fabric for an airbag, and to promote the spread of an occupant protection system using the airbag. Can be.

[Brief description of the drawings]

FIG. 1 shows a method for measuring expansion and deployment characteristics.

[Explanation of symbols]

 1: Airbag viewed from face contact side 2: Length in vertical direction 3: Length in horizontal direction

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D054 AA02 AA03 AA04 AA16 CC26 CC30 DD28 FF18 FF20 4L048 AA24 AA48 AA49 AB07 AC09 AC10 BA01 BA02 CA00 CA01 CA02 CA04 CA11 CA15 DA25 EA01 EB00 EB05

Claims (6)

[Claims] 1. An airbag fabric comprising a synthetic fiber woven fabric, wherein the tensile elongation in the warp direction and the weft direction under a tension of 260 N / cm are both 10 to 30%. Base fabric for airbags. 2. The difference in tensile elongation between the warp yarn direction and the weft yarn direction of the airbag base fabric under a tension of 260 N / cm,
The base fabric for an airbag according to claim 1, wherein the content is 0 to 7% or less. 3. The airbag base fabric according to claim 1, wherein the warp yarn density and the weft yarn density of the airbag base fabric are different. 4. The airbag fabric according to claim 1, wherein one of the warp yarn density and the weft yarn density is from 80% to 97% of the other.
%. The base fabric for an airbag according to any one of claims 1 to 3, which is in the range of%. 5. The airbag base fabric according to claim 1, wherein the cover factor of the airbag base fabric is in the range of 1500 to 2500. 6. An airbag comprising the base fabric for an airbag according to claim 1.