JP2002144995A - Air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost air bag excellent in the accommodation property, air-tightness, and the safety. SOLUTION: The air bag is structured so that a resin to make welding attachment with high frequency is laminated with a bonding force of 14.7 N/2-cm width or more to at least one surface of a cloth made of synthetic fiber, wherein the degree of aeration measured according to JIS L 1096 (6.27.1A method) should be 0.1 cc/cm2/sec or less, and this base cloth for air bag is sewn with the resin put in welding attachment with high frequency.

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 excellent in airtightness suitable for an inflatable curtain airbag. It is about.

[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 during a vehicle collision.

Conventionally, a plain fabric using nylon 6.6, nylon 6, or polyester filament yarn of 230 to 1100 decitex is coated with a resin such as chloroprene, chlorosulfonated olefin, or silicone, and a base fabric obtained by laminating the same is used. A so-called non-coated base fabric sewn with a sewing machine, which does not apply a resin for the purpose of improving storability, is used for a driver's seat, a passenger seat, and a side airbag.

In recent years, attention has been paid to inflatable curtain airbags for protecting occupants in the event of a side collision or rollover. When the bag is inflated and deployed, it must remain inflated for 2 to 8 seconds to maintain its form, so that the bag is more airtight than the driver or passenger airbag. Is required.

[0005] Normally, sewing of the airbag is performed by sewing. However, since air leakage from the sewing portion of the sewing machine cannot be avoided, the inflatable curtain airbag is formed by a jacquard loom so as not to sew the sewing machine. And the entire surface of the woven fabric is coated with a silicone resin or the like to prevent air leakage.

[0006]

However, such an airbag requires a special weaving machine, and the resin is applied to the uneven jacquard fabric surface, so that a large amount of resin is required, which is heavy and costly. It was expensive and had a problem in the storability.

[0007] In view of the background of the prior art, the present invention provides
An object of the present invention is to provide an airbag which is low in cost, excellent in storage, airtightness and safety.

[0008]

The present invention employs the following means in order to solve the above problems. That is, the airbag of the present invention is formed by laminating a high-frequency welding resin on at least one surface of a synthetic fiber fabric with an adhesive force of 14.8 N / 2 cm or more in width.
A base fabric for an airbag having an air permeability of 0.1 cc / cm ² / sec or less as measured according to 96 (6.27.1A method) is sewn by welding the resin at a high frequency. It is assumed that.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has been made as a result of intensive studies on the above-mentioned problems, that is, airbags which are excellent in safety, and furthermore excellent in storability and cost, especially for inflatable curtain airbags. The present inventors have sought to solve the above-mentioned problems at a stroke by sewing the airbag base fabric by high frequency welding.

The yarns constituting the synthetic fiber cloth in the present invention include nylon 6.6, nylon 6, nylon 1
2. Polyamide fiber consisting of polyamide homopolymer such as nylon 4.6 or copolymer of nylon 6 and nylon 6.6, copolymerized polyamide obtained by copolymerizing nylon 6 with polyalkylene glycol, dicarboxylic acid or amine, polyethylene terephthalate A polyester homopolymer such as polybutylene terephthalate or a polyester fiber comprising a copolymerized polyester obtained by copolymerizing an aliphatic dicarboxylic acid such as isophthalic acid, 5-sodium sulfoisophthalic acid or adipic acid as an acid component, paraphenylene terephthalamide And aramid fibers, rayon fibers, polysulfone fibers, ultra-high molecular weight polyethylene fibers and polymer array fibers having a sea-island structure mainly composed of the above synthetic fibers, represented by copolymerization with aromatic ethers. Synthetic fibers made is used. Among these, nylon 6.6, polyamide fiber of nylon 6, and polyethylene terephthalate fiber are preferable, and polyamide fiber is more preferable in terms of impact resistance. Such fibers may contain various additives that are commonly used for improving productivity or characteristics in the production or processing steps of the raw yarn. For example, heat stabilizers, antioxidants, light stabilizers, leveling agents, antistatic agents, plasticizers, thickeners,
Pigments, flame retardants and the like can be added.

The total fineness and single yarn fineness of the yarn constituting the woven fabric of the present invention are preferably in a range that satisfies the mechanical properties and storability required for an airbag. That is, the preferable total fineness is in the range of 110 dtex to 560 dtex, and the preferable single yarn fineness is 0.6 decitex to 8 dtex.
The range of decitex. If the total fineness and the single-filament fineness of the yarns constituting the woven fabric are too small, the strength as an airbag tends to decrease. Conversely, if the total fineness and single yarn fineness of the yarns constituting the woven fabric are unnecessarily large, the woven fabric becomes bulky and, as a result, tends to be inferior in compactness.
Further, it is preferable that the warp yarn and the weft yarn have substantially the same total fineness in terms of the mechanical characteristics of the airbag and the isotropic surface in the warp direction and the weft direction of the storability.

[0012] The fabric of the present invention comprising the above fibers is a woven fabric,
It is composed of at least one kind of knit, non-woven fabric, etc., and preferably a woven fabric is used in view of mechanical properties such as strength. Further, as a structure constituting a woven fabric, a plain weave, a twill weave, a satin weave and their modified weaves, a multiaxial weave, and the like are generally used. Fabrics are preferred.

The woven fabric has a cover factor of 1
It is preferably from 500 to 2500. If the cover factor is smaller than 1500, the mechanical properties tend to decrease and the air permeability tends to increase. If the cover factor is larger than 2500, the woven fabric tends to be hard and the flexibility tends to be poor. Here, the cover factor means the total fineness of the warp yarn as D ₁ (dtex) , Warp yarn density to N
₁ (line / 2.54 cm), and the weft total fineness is D ₂ (dt
ex), when the weft density is N ₂ (lines / 2.54 cm), (D ₁ × 0.9 ) ^1/2 × N ₁ + (D ₂ × 0.9) ^1/2
× N ₂ .

As a loom for weaving the woven fabric of the present invention, a water jet room, an air jet room, a rapier room and the like are used.

Further, the woven fabric of the present invention may be subjected to scouring / setting processing, calendering processing, resin processing, etc., if necessary.

The basis weight of the woven fabric of the base fabric for an airbag is preferably 300 g / m ² or less from the viewpoint of weight reduction, and the stiffness is 100 mm in both the warp and weft directions. The following is preferable in terms of flexibility. Further, the tensile strength of the base fabric is 300
N / cm or more, tensile elongation 15% or more, tear strength 50
N or more is preferable from the viewpoint of storability of the airbag and prevention of rupture when used as an airbag.

The airbag fabric constituting the airbag of the present invention has an air permeability of 0.1 cc / cm ² / sec measured according to JIS L1096 (6.27.1A method).
c or less, and more preferably 0.0
It is 5 cc / cm ² / sec. The air permeability is 0.1cc /
If it is larger than cm ² / sec, when the airbag is deployed, gas leaks from the base fabric constituting the bag, which may cause a problem in occupant restraint.

In the airbag fabric of the present invention, a resin having a high-frequency welding property is laminated on at least one surface of the fabric in order to impart airtightness by the low air permeability and the high-frequency welding sewing described above. Such a high-frequency welding resin is not particularly limited as long as it generates heat and is integrated when a high frequency is applied, but at least one selected from urethane-based resins, olefin-based resins, and polyamide-based resins. It is preferably used. Such a resin is applied and laminated by a known method such as a knife coater, a comma coater, a roll coater or a rotary screen,
A film formed by a die or a calendar may be laminated. An adhesive may be used to adhere such a resin to the fabric. The amount of laminating a resin is low air permeability of the high-frequency weldability, preferably 10 to 50 g / m ^2, more preferably a 20 to 30 g / m ^2.

The high-frequency welding resin may contain various additives which are generally used for improving productivity or characteristics in a manufacturing process or a processing process such as coating, film forming, and bonding. For example, heat stabilizers, antioxidants, light stabilizers, leveling agents, antistatic agents, plasticizers, thickeners, pigments, flame retardants, high-frequency dielectrics, and the like can be included.

The adhesive strength between the cloth of the present invention and the high frequency welding resin is 14.7 N / 2 cm width or more, preferably 19.6 N.
/ 2cm width or more, more preferably 29.4N / 2cm
It is necessary that the width be equal to or larger than the width in order to prevent peeling due to the expansion and deployment pressure. If the width is less than 14.7N / 2cm, 2
In the case of an inflatable curtain that needs to maintain its shape at a high pressure for up to 8 seconds, air may leak due to peeling at a welded portion.

In the sewing of the present invention, in order to enhance safety,
It is preferable to perform both welding sewing and sewing sewing.
Such two kinds of sewing may be parallel or may overlap at the same place. Among them, it is preferable to sew the same place by two kinds of methods because the reliability of the sewn part is high. In the case of sewing by such a method, it is necessary to perform high frequency welding on the sewing machine after sewing. Since the sewing hole formed by sewing can be filled with a high-frequency welding resin, this is preferable in improving the airtightness of the sewing portion.

In the case of high-frequency sewing on the sewing machine, if the sewing thread is covered with the same resin as the resin laminated on the cloth, the airtightness of the sewing portion can be further improved. Alternatively, the sewing portion of the sewing machine may be coated with a laminated resin using a brush or the like, dried, and then subjected to high frequency sewing.

The case where high frequency welding sewing is performed on a portion where the sewing machine is sewn will be described in more detail. 470 decitex, 120 filament nylon 6.6 fiber is used for warp and weft yarns, and a water jet loom is used to make a plain weave with both warp / weft yarn density of 46 / 2.54 cm. One surface of the greige was knife-coated with a solvent-based polycarbonate urethane resin to form a resin layer having a solid content of 40 g / m ² and a permeability of 0.01 c / m ^2.
The base fabric is c / cm ² / sec or less. Two pieces having a size of 150 cm × 40 cm are cut from the coated fabric, and the coated surfaces are overlapped with each other and sewn in a shape as shown in FIG. The used sewing thread is a 1400 dtex, 108 filament nylon 6.6 fiber obtained by adhering 5 g / m of the same resin as the resin used for coating the fabric by dipping. Then, a copper mold (having a width of 2 cm so that the sewing thread is at the center) having the same shape as the design sewn on the sewing machine was set in a high-frequency welding machine and heated to 100 ° C.
When a pressure of 392 KPa is applied for 5 seconds with a transmission current of A, a bag-shaped airbag for an inflatable curtain without air leakage is obtained.

More than 90% of the total weight of the cloth used for the airbag of the present invention, the resin for laminating the cloth, the sewing thread and the high-frequency welding resin covering the sewing thread is formed of an organic polymer having the same composition. If the organic polymer is nylon 6, it can be recycled chemically, and can be recycled into monomers, including base fabric and sewing thread waste, if the organic polymer is nylon 6. Thus, it is possible to provide an environmentally friendly airbag that can be reused.

The airbag of the present invention can be used for all types of airbags, such as those for the driver's seat, the passenger's seat, the side, and the curtain. It is.

The present invention will be described with reference to the drawings. FIG. 1 shows an example of an inflatable curtain airbag, in which two base fabrics which are vertically overlapped form a bag body by a joint portion 1, and when deployed, high-pressure gas is supplied from an opening 2. It is injected, inflated, and deployed. FIG. 2 similarly shows another example of the inflatable curtain airbag.

The airbag of the present invention is highly airtight and can prevent air leakage by high frequency welding and sewing.

[0028]

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

Various performances in the examples were evaluated by the following methods.

Adhesive force between cloth and resin: Using a high-frequency welder welding machine (YF-7000A manufactured by Yamamoto Vinita Co., Ltd.), a mold having a width of 2 cm and a length of 65 cm was heated to 100 ° C., and the output was 7 kW and the current was 7 1.3A, pneumatic 392kP
a, welding time 5 seconds, cooling time 2 seconds, JIS K
Adhesive force (kg / 2c) based on 6328 (5.3.7)
m width). The case where the peeled portion was the interface between the fabric and the laminated resin was indicated by ○, and the case where the peeled portion was the interface of the welded portion between the laminated resins was indicated by ×.

Formation of a bag: A bag-like woven fabric having the shape shown in FIG. 2 was formed in a size of 150 cm × 40 cm by a jacquard loom or sewing.

Weight of bag-like product: The weight of the bag shown in FIG. 2 was measured with an electronic balance.

Thickness of bag-like product: The thickness of the portion where two base fabrics forming the bag portion of the bag shown in FIG. 2 are overlapped was measured with a Peacock thickness gauge.

Air permeability of bag-like product: The bag was immersed in water for 15 seconds while sending air at a pressure of 60 kpa, and the degree of air leakage was confirmed by the state of generation of bubbles.

；: No bubbles were generated.

△: Slight foam generation.

×: A large amount of bubbles are generated. Examples 1 to 19 and Comparative Examples 1 to 5 Plain fabrics were woven on a water jet loom using the original yarns shown in (1) to (4) below as warp yarns and weft yarns, respectively. Table 1 shows the results of evaluating the performance by treating the woven fabric by the method described below. Yarn (1) Nylon 6.6 fiber having a total fineness of 470 dtex and 136 filaments. Yarn (2) Nylon 6 fiber having a total fineness of 470 dtex and 96 filaments. Raw yarn (3) Nylon 6.6 fiber having a total fineness of 350 dtex and 108 filaments. Raw yarn (4) Nylon 6.6 fiber having a total fineness of 235 dtex and a single filament count of 72 filaments. <Resin Laminating Method> (A) Polycarbonate polyurethane (solid content 25
%) With a knife coater, dried at 130 ° C., 16
Heat treated at 0 ° C. (B) An adhesive having the following composition is applied to one surface of the woven fabric using a gravure coater, and dried at 130 ° C. to reduce the solid content to 15%.
g / m ² , and a polycarbonate polyurethane (solid content: 25%) was further applied by a knife coater.
And heat-treated at 160 ° C. (C) Polycarbonate polyurethane (solid content 25
%) On release paper with a knife coater,
And heat-treated at 160 ° C. to form a 30 μm film. The formed film is coated with an adhesive having the following composition by gravure so that the solid content becomes 15 g / m ² , and dried until the adhesive becomes tacky. 196kPa between metal rolls
Then, the film was wound up and aged in an atmosphere of 50 ° C. for 48 hours in that state. (D) Nylon 6 was extruded with a T-die, a 40 μm film was formed, and bonded to one side of the fabric in the same manner as (C). (E) One side of the woven fabric was coated with a silicone resin (solid content: 45%) by knife coating, dried at 130 ° C., and heat-treated at 180 ° C. to obtain a solid content of 40 g / m ² . <Adhesive> Polyester polyurethane (solid content 50%
A solution in which 20 parts of a trifunctional isocyanate (75% solids in ethyl acetate solvent solution) and 6 parts of a chain extender (75% solids in ethyl acetate solvent solution) were used in 100 parts of an ethyl acetate solvent solution. <Sewing> The sewing machine was sewn and the high frequency welding was sewn under the following conditions under the design shown in FIG. In the high frequency sewing, a design-molded mold having a width of 2 cm was heated to 110 ° C., and under a condition of an output of 35 kW and a current value of 1.8 A, a pressing pressure of 490 was used.
Welding was performed at kPa, a welding time of 7 seconds, and a cooling time of 3 seconds. The sewing thread used was 1110 dtex, 108 filaments of nylon 6 and 6.6 fibers, and was covered with the same resin as the resin laminated on the fabric. The polymer type of the woven fabric and the sewing thread was the same.

Sewing (a) High-frequency welding only sewing (b) High-frequency welding sewing on sewing machine sewing part Sewing (c) High-frequency welding sewing 1 cm inside sewing machine sewing part Sewing (d) 1 cm outside sewing machine sewing part (F) Sewing machine only Only the original thread (1) is woven with a jacquard loom in the design of FIG. 2 and 70 g /
m ² (Comparative Example 5), 120 g / m ² (Comparative Example 6) The coated product was evaluated in the same manner as in the Examples.

[0039]

[Table 1]

As is clear from Table 1, the inflatable curtain of the embodiment is superior in airtightness, lighter weight, thinner and more excellent in storage than the comparative example, and has a merit of cost. You can see that. Further, it can be seen that the effects of the embodiment can be obtained by sewing the sewing machine without using a special weaving device such as a jacquard loom as in Comparative Examples 5 and 6.

[0041]

According to the airbag of the present invention, sewing is sewn and high-frequency welding is combined, so that the airtightness of the sewn portion is high, the occupant restraint is excellent, and the storage is excellent. Therefore, the airbag is particularly economical for inflatable curtains. It can provide an excellent bag.

[Brief description of the drawings]

FIG. 1 is an overall view and a sectional view showing an example of an inflatable curtain airbag of the present invention.

FIG. 2 is an overall view showing an example of an inflatable curtain airbag.

[Explanation of symbols]

 1: Joint 2: Opening

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // D06M 101: 34 D06M 101: 34 F term (Reference) 3D054 AA16 CC04 CC30 CC34 CC38 CC42 CC45 EE20 FF13 FF14 FF16 FF18 FF20 4L031 AA20 AB32 CA08 CB01 4L033 AA08 AB05 AC11 AC15 CA11 CA50 CA52 CA55 CA59 4L048 AA24 AB07 BA01 CA11 CA12 CA15 DA25 EA01

Claims (11)

[Claims] 1. A high-frequency welding resin is laminated on at least one surface of a cloth made of synthetic fiber with an adhesive force of 14.8 N / 2 cm or more in width, and JIS L 1096
An airbag base fabric having an air permeability of 0.1 cc / cm ² / sec or less measured based on (6.27.1A method) is sewn by high frequency welding of the resin. Airbags. 2. The airbag according to claim 1, wherein said adhesive strength is not less than 19.6 N / 2 cm width. 3. The airbag according to claim 1, wherein the sewing is sewing combined with sewing of a sewing machine. 4. The airbag according to claim 3, wherein the sewing thread is covered with a resin having the same composition as the resin. 5. The airbag according to claim 3, wherein the sewing portion and the welding portion are arranged side by side. 6. The airbag according to claim 3, wherein said sewing portion and said welding portion overlap each other. 7. The airbag according to claim 6, wherein a sewing hole of the sewing portion is filled with a high-frequency welding resin. 8. The high-frequency welding resin is a urethane resin,
The airbag according to any one of claims 1 to 7, wherein the airbag is at least one selected from an olefin resin and a polyamide resin. 9. The airbag according to claim 1, wherein 90% by weight or more of the total weight of the airbag base fabric and the sewing thread is formed of an organic polymer having the same composition. 10. The airbag according to claim 9, wherein the organic polymer is nylon 6. 11. The airbag according to claim 1, wherein the airbag is an inflatable curtain airbag.