JPH04262938A - Air bag - Google Patents

Abstract

PURPOSE:To obtain an air bag which has no bent hole. CONSTITUTION:An air bag which has no bent hole is formed by weaving at least two kinds of fabrics together, such as a high density fabric F1 of not less than 1500 of cover factor and of not less than 0.6 of fiber filling factor, which is woven by using a stretch-broken thread string including high power heat-resistant fiber of not more than 2 denier of single thread weaving degree, of not less than 16g/de of intensity, and of not lower than 300 deg.C of heat decomposition temperature, and a low density fabric F2 of not less than 700 of cover factor and of less than 0.6 of fiber filling factor, which is woven by using the stretch-broken thread string including the same fiber as the F1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to airbags for automobiles. More specifically, the present invention relates to an airbag that is thin and lightweight, has excellent storage properties, and has no vent holes, so there is no risk of burns to humans.

0002

[Prior Art] Conventional airbags are made by weaving high-strength filaments made of thermoplastic synthetic fibers such as nylon 6, nylon 66, and polyester with a total fineness of 400 to 1000 deniers into a plain weave or ripstop fabric, and adding chloroprene to the fabric. Alternatively, a bag coated with a large amount of elastomer such as silicone and sewn into a bag as shown in FIG. 2 has been used. It has also been put to practical use as a device as shown in Figure 5 (Special Publication No. 48-3029
Publication No. 3, Publication of Utility Model Application No. 1983-81543, Publication of Utility Model Application No. 1987-81543
-17936, etc.).

[0003] In other words, all of these airbag fabrics have heat resistance and flame resistance, so that when an airplane or automobile crashes, the power cord D of the inflator B is connected to the power cord D as shown in FIG. It is designed to be able to withstand the high-temperature blast and flame ejected from the combustion gas injection port C when an electric current flows and the inflator burns and the airbag A1 expands into a spherical shape.

[0004]However, in order to meet safety standards, conventional airbags are coated with elastomer with a fairly high fabric weight, which makes the airbags heavy and stiff, significantly reducing the ease of handling during sewing. In addition to
The volume when folded is large, which is an obstacle when installing it in a vehicle.

[0005] Another problem is that high-temperature combustion gas is blown out into the outside air at once through a pair of holes with a diameter of about 30 mm called vent holes provided in the air bag, making it easy to cause burns.

[0006]

OBJECTS OF THE INVENTION The present invention has been made to solve such problems in the prior art. In other words, the airbag is lightweight and thin, so it can be stored compactly in the steering wheel, and it can withstand the high-temperature blast and flames emitted from the inflator in the event of a collision.It also has no vent holes, so there is no risk of burns. The purpose is to provide

[0007]

[Structure of the Invention] That is, the present invention provides: ``(Claim 1) Single yarn fineness of 2 de or less, strength of 16 g/de or more, thermal decomposition temperature of 300 de
Cover factor 1500 or more, fiber filling rate 0.6-0, woven using yarn containing high-strength heat-resistant fibers of ℃ or higher
．． A cover factor of 700 or more and a fiber filling rate of 0.3 to 0.9 is woven using the fabric F1 of No. 9 and a yarn containing the same fiber.
An airbag characterized in that it is made by sewing at least two or more types of fabrics, including a fabric F2 of less than 6, and does not have a vent hole.

(Claim 2) Thermoplastic synthetic fibers having a single yarn fineness of 5 de or less and a Young's modulus of 1300 kg/mm 2 or less are contained in the woven fabric F1 in an amount of 30 to 90% by weight, and in the woven fabric F2 in an amount of 0 to 9% by weight.
2. The airbag according to claim 1, wherein the airbag contains 0% by weight of mixed fibers.

(Claim 3) The air permeability of the fabric F1 is the same as that of the fabric F2.
The airbag according to claim 1 or 2, wherein the air permeability is smaller than the air permeability of the airbag.

(Claim 4) The fabric F1 mainly occupies the bag-like object closer to the human body than the steering side, with the circumferential sewing part for forming the bag-like object being the boundary, and the fabric F2 occupies the bag-like object closer to the human body than the steering side. The airbag according to any one of claims 1 to 3, which mainly occupies a side bag-like object.

(Claim 5) The airbag according to any one of Items 1 to 4, wherein the high-strength heat-resistant fibers are para-aromatic polyamide fibers.

(Claim 6) The airbag according to any one of Claims 1 to 5, wherein the thermoplastic synthetic fiber is a polyester fiber.

(Claim 7) The airbag according to any one of Claims 1 to 6, wherein the yarn is a tension-cut spun yarn produced by a tension-cutting method.

(Claim 8) Claim 1, wherein the fiber yarn is obtained by tearing the fibers between a supply roller and a tension cutting roller while preventing disturbance of the fibers, and then combining the fibers with an air nozzle. Any of the airbags listed in ~7. ”
It is.

[0015] The high-strength heat-resistant fiber in the present invention refers to a fiber having a strength of 16 g/de or more and a thermal decomposition temperature of 300°C or more. The strength of the high tenacity heat resistant fiber is 16 g/de or more. If it is less than 16 g/de, sufficient strength cannot be obtained when it is made into a fabric, and the air bag is often damaged during inflation. In particular, in the case of fiber yarns mixed with thermoplastic synthetic fibers, the strength of the heat-resistant fibers is 16 g/
de or more is required, preferably 18 g/de or more.

[0016] The thermal decomposition temperature of the high-strength heat-resistant fiber is 300°C.
The above is necessary. Even if the strength is 16 below 300℃
Even if it exceeds g/de, the airbag is often damaged during inflation. Therefore, the thermal decomposition temperature of high-strength, heat-resistant fibers must be 300°C or higher, and 350°C.
The above is even better.

Specifically, for example, meta or para fully aromatic polyamide fiber (aramid fiber), specifically polymetaphenylene isophthalamide fiber, polyparaphenylene terephthalamide fiber, para-aramid and meta-aramid. copolymer fibers, para-aramid fibers copolymerized with aromatic ethers such as 3,4'-diaminodiphenyl ether, polyparaphenylene sulfone fibers, polyparaphenylene sulfide fibers, fully aromatic polyester fibers, polyimide fibers, polyetherimide fiber, polyetheretherketone fiber, etc.
Or a mixture of these fibers.

Among these, polyparaphenylene terephthalamide fiber (Kevlar fiber: manufactured by DuPont) and 3,4'
Particularly preferred are para-aramid fibers copolymerized with -diaminodiphenyl ether (Technora fiber; manufactured by Teijin).

The present inventors have discovered that an airbag made of a fabric containing such high-strength, heat-resistant fibers will not melt, fail, or burst into flames when exposed to high-temperature blasts or flames emitted from an inflator.

[0020] The single filament fineness of the high-strength, heat-resistant fiber must be 2 de or less. It is extremely important for airbags to be flexible because they need to be folded into a small size. 2de
If it exceeds this, the resulting airbag will be extremely stiff. Furthermore, since the number of fibers constituting the yarn is reduced and the fiber gaps are widened, the air permeability of the fabric increases. It becomes impossible to sufficiently block out the high-temperature blast and flame emitted from the inflator. Furthermore, the single yarn fineness is small,
The greater the number of constituent fibers, the better the flame contact resistance, and from this point of view as well, the single fiber fineness of the high-strength, heat-resistant fibers must be 2 de or less.

[0021] The fiber filling rate of a woven fabric in the present invention refers to a value obtained by dividing the bulk specific gravity of the woven fabric by its true specific gravity. Fiber filling rate is 0.
If it is less than 30, the hiding effect of the fabric will be low, and it will not be possible to sufficiently block out the high-temperature blast and flame emitted from the inflator. Therefore, the fiber filling rate needs to be 0.30 or more. Moreover, if the fiber filling rate exceeds 0.9, the flexibility of the fabric will be lost and the resulting airbag will be extremely film-like. Therefore, the fiber filling rate is 0
．． 30 or more, preferably 0.9 or less, 0.35 or more, 0
．． More preferably 85 or less.

[0022] The fiber filling rate is determined by the weaving density, weaving structure, and the upper and lower 1
It can be determined by the hot-pressing processing conditions of a pair or more of metal/elastic calender rollers or metal/metal calender rollers. The surface temperature of the metal roller at this time is 15
The temperature is preferably 0 to 300°C, and the calender pressure is preferably 100 kg/cm or more. To achieve a sufficient hot-pressure effect, it is desirable to preheat the fabric or process it at low speed.

The cover factor of a woven fabric in the present invention is the sum of the warp and weft of the product of the square root of the yarn fineness and the number of yarns per inch. If the cover factor is less than 700, the hiding effect of the fabric will be low, and even if it is treated with a resin, for example, it will not be able to sufficiently block out the high-temperature blast and flame emitted from the inflator. Therefore, a cover factor of 700 or more is required. Also, the cover factor is 3
If it exceeds 900, the fabric loses its flexibility and the resulting airbag becomes extremely stiff. Therefore, the cover factor is preferably 700 or more and 3900 or less, and 8
More preferably, it is 00 or more and 3500 or less.

The fiber filling rate and cover factor in the present invention are important factors that determine the performance of the airbag, and by satisfying both of the above values, the air permeability of the fabric can be controlled while providing flexibility without vent holes. It can be made into a compact airbag.

[0025] The airbag according to the present invention is made of woven fabric F1 obtained by weaving the above threads and having a cover factor of 1500 or more and a fiber filling rate of 0.6 to 0.9, and a fabric F1 that has a cover factor of 700 or more and a fiber filling rate of 0.3 to 0.9. Fabric F2 less than 0.6
It is made by sewing at least two types of fabrics. This is because the fabric F1 is used as the main body base fabric, and the fabric F2 is used as a vent cloth instead of a vent hole. Fabric F2, which is a vent cloth, is a filter cloth for releasing high-temperature gas to the outside of the airbag, so fabric F1 is used as a vent cloth.
It is necessary that the cover factor and/or fiber filling rate be small and the air permeability be large compared to the above. For this reason, it is desirable that the fabric F2 has a structure other than a plain weave, such as a twill weave, to have relatively high air permeability. Therefore, the fabric F1 needs to have a cover factor of 1500 or more, preferably 2000 or more and 3900 or less,
Further, the fiber filling rate is required to be 0.6 to 0.9. Further, the woven fabric F2 needs to have a cover factor of 700 or more, preferably 1000 or more and 3000 or less, and a fiber filling rate of 0.3 to less than 0.6.

[0026] The fabric F1 and/or the fabric F2 in the present invention may be provided with a flexible resin. Flexible resins include urethane resin, silicone rubber, chloroprene rubber, chlorosulfonated olefin rubber, fluorine rubber,
These include vinyl chloride resin, chlorinated olefin resin, fluorine resin, and modified products thereof. Further, organic and inorganic flame retardants such as halogen-based, phosphorus-based, and metal hydroxides may be blended, or a mixed resin of two or more types may be used. Among these resins, urethane resins or modified products thereof are preferred because they have particularly good adhesion to high-strength, heat-resistant fibers.

[0027] Thermoplastic synthetic fibers in the present invention are fibers made of ordinary thermoplastic synthetic resins, such as polyester fibers, nylon fibers, acrylic fibers, and polypropylene fibers. Polyester fibers are preferred.

The fiber yarn containing the high-strength heat-resistant fiber in the present invention may be a mixture of the above-mentioned thermoplastic synthetic fibers in the order of single fibers. The fineness of single fibers of thermoplastic synthetic fibers is the same as that of high-strength, heat-resistant fibers, and also because if the fineness of single fibers is large, the number of fibers that make up the yarn decreases, making it difficult to obtain a uniform blend. Hereinafter, it is preferable to set it to 2.5 de or less.

[0029] Furthermore, the Young's modulus of thermoplastic synthetic fiber is 13
00 kg/mm2 or less is preferable. 1300k
If it exceeds g/mm2, the Young's modulus of the other components, high-strength, heat-resistant fibers, will be too high, and the Young's modulus of the yarn after blending will be too high, resulting in a fabric that is coarse and stiff after weaving. This is not desirable. Therefore, the Young's modulus of the thermoplastic synthetic fiber is 1300 kg/mm2 or less, preferably 1200 kg/mm2 or less.
kg/mm2 or less is good.

The woven fabric F1 of the present invention may be a mixture of the above-mentioned thermoplastic synthetic fibers in the order of single fibers. The ratio of thermoplastic fibers in the fabric F1 at this time is 30 to
90% by weight is preferred. Particularly preferably 40 to 80% by weight. If the proportion of thermoplastic synthetic fiber exceeds 90% by weight, the heat resistance of the fabric will decrease. In addition, sufficient strength cannot be obtained unless the thickness of the yarn is considerably thickened, which is undesirable as it results in a thick woven fabric. In addition, the ratio of thermoplastic synthetic fibers is 3
If it is less than 0% by weight, the heat shrinkage of the high-strength, heat-resistant fibers will be limited, making it difficult to obtain dense woven fabrics with low air permeability.

[0031] The woven fabric F2 may also be a mixture of the above-mentioned thermoplastic synthetic fibers in the order of single fibers. At this time, the proportion of thermoplastic synthetic fibers in the fabric F2 is preferably 0 to 90% by weight. Particularly preferred is 0 to 80% by weight. If the proportion of thermoplastic synthetic fiber exceeds 90% by weight, the heat resistance of the fabric will decrease. In addition, sufficient strength cannot be obtained unless the thickness of the yarn is considerably thickened, which is undesirable as it results in a thick woven fabric.

[0032] It is preferable that the above-mentioned thermoplastic synthetic fibers be blended into the fabric F1 and the fabric F2 during the yarn manufacturing process. Furthermore, compared to the fabric F1, the fabric F2 has a lower fabric density, so its strength tends to decrease. Therefore, it is desirable to increase the proportion of high-strength, heat-resistant fibers.

[0033] Airbags can be made by sewing two circular fabrics together along their circumferences, but when the airbag is made, one of them is placed on the human body side, and the other side is placed on the opposite side. One piece will be located on the steering side. In this case, it is desirable that the fabric F1 primarily occupy the bag-like object closer to the human body than the steering wheel, and that the fabric F2 mainly occupy the bag-like object closer to the steering wheel than the human body. For this reason, the more airtight fabric F1 is mainly located on the side in contact with the human body to prevent the passage of high temperature gas, and the less airtight fabric F2 is mainly located on the steering side and acts as a vent cloth to effectively trap high temperature gas. It can be discharged outside the bag. From the point of view of workability, woven fabric F1
It is desirable to sew the fabric F2 on the entire surface of the human body side and the fabric F2 on the entire surface of the steering wheel side. Since the area ratio of the fabric F1 and the fabric F2 is determined based on their respective air permeability, the fabric F2 may be used for only a small portion of the steering side.

It is desirable that the threads constituting the apron fabric contain more high-strength, heat-resistant fibers than the threads constituting the main body fabric. In this case, the increase in the amount of high-strength heat-resistant fibers is preferably 5% by weight or more. Any number of aprons may be used, but if there are too many layers, folding will deteriorate. The preferred number is 1 to 4, and more preferably 2 to 3. Further, as for the construction of the apron, it is preferable to arrange a woven fabric in which high-strength, heat-resistant fibers are mixed in a larger amount toward the inner surface of the bag, which is in direct contact with the gas from the internator. That is, at least one apron having a high proportion of high-strength heat-resistant fibers may be laminated on the inner surface of the bag, and the several layers of aprons in the lower layer may have the same proportion of high-strength heat-resistant fibers as the main body. As a result, heat resistance, especially in the apron, is significantly increased and reliability is improved.

[0035] The yarn of the woven fabric in the present invention is preferably made of tension-cut spun yarn produced by a tension-cut method. Since tension-cut spun yarn has fluff in its yarn form and its fibers are randomized, it is possible to reduce the air permeability by making the gaps in the fabric structure smaller compared to continuous filaments. Furthermore, the frictional resistance between the fibers is large, making it difficult for seam slippage to occur in the sewn portion. On the other hand, compared to conventional spun yarns, it has a higher degree of fiber arrangement, is stretched to the limit by tension cutting, and has a longer fiber length, making it a highly tenacious yarn, making it extremely suitable for use in airbags.

Next, an example of a method for producing a tension-cut spun yarn of high-strength heat-resistant fiber will be explained with reference to the drawings.

FIG. 1 shows a fiber mixing device. 1 is a nip roller, 2 is a shooter, 3 is a tension nip roller, 4 is a suction air nozzle, 5 is a combination nozzle using a swirling flow, 6 is a delivery roller, and 7 is a thread. The high-strength heat-resistant fibers pass through the supply nip roller while being aligned and overlapped in front of the supply nip roller 1, and are simultaneously torn off by the tension-cut nip roller in the shooter 2, and are uniformly tension-cut while being drafted. Next, the short fibers are torn off from the tension cutting roller by the suction air nozzle 4, and after being given conjugation properties by entanglement and fluff wrapping by the rotating conjugation nozzle 5, they are torn off by the delivery roller 6, and the fluff of the short fibers is attached to the side of the fiber bundle. The thread 7 is randomly wrapped around the thread 7.

[0038] After appropriately twisting the obtained yarn, it was woven into a desired density using warp and weft yarns, and after being scoured, heat set, relaxed, and calendered, it was sewn into a bag as shown in Fig. 2. and air bag A1. In addition, B in the figure
C1 is a main body made of fabric F1, C2 is a main body made of fabric B, and D is a vent cloth made of fabric F2.

[0039]

[Effects of the Invention] The airbag according to the present invention has the following effects compared to conventional airbags. (1) It is flexible and has excellent foldability. (2) Small volume when folded. (3) It is lightweight. (4) There is no risk of burns because there is no vent cloth. (5) It has heat resistance, high strength, and airtightness to withstand high-temperature blast waves and flames. (6) Impact and abrasion resistance during deployment are small and will not cause damage. (7) Easy to sew. (8) Not easily damaged by metal pieces, glass pieces, etc. (9) There is little change in the performance of the airbag fabric even after a long period of time.

The present invention will be explained below with reference to Examples. In addition, each evaluation item in Examples was evaluated according to the following method.

Tensile strength: Measured by the strip method of JIS L-1096.

Air permeability: Measured by the Frazier method of JIS L-1096.

Inflation resistance: The material was sewn into the shape of an airbag, attached to an airbag device, the inflator was burned, and the presence or absence of damage to the airbag was evaluated.

Storing property: The airbag is folded along the dotted line E shown in FIGS. 3(A) and 3(B) to form the shape shown in FIG. 3(C), and a load W of 5 kg is added to this as shown in FIG. The thickness t was measured.

[0045] Texture: Regarding the feel and flexibility of the fabric surface, a sensory evaluation was conducted assuming that the face would be strongly hit by an airbag in the event of a collision, and the fabrics were classified into soft ones and rough and stiff ones.

[0046]

[Example 1] Using the device shown in Figure 1, a single yarn fineness of 1.3 was obtained.
denier, strength 7.2 g/de, total fineness 4000 denier polyester fiber (Tetron: manufactured by Teijin Ltd.),
Para-aromatic polyamide fibers (Technora: manufactured by Teijin Ltd.) with a single yarn fineness of 0.75 denier, a strength of 28 g/de, and a total fineness of 1000 denier are layered and aligned, and a supply nip with a distance between rollers of 100 cm is used. Approximately 16 times 30 between roller 1, shooter 2, and tension roller 3
They were simultaneously torn at a speed of 0 m/min to form thin single fiber bundles. Subsequently, the air is passed through an air nozzle 4 having a suction property and a binding nozzle 5 having a swirling flow at a speed ratio of 100:97 between a tension nip roller 3 and a delivery roller 6 to impart entanglement and to separate fluff from single fibers into fibers. The yarn was randomly wrapped around the side of the bundle to obtain yarn 7 of 300 denier.

The ratio of polyester fibers and para-aromatic polyamide fibers in the yarn obtained was 80:20. The average fiber length of these yarns is 42c for polyester fibers.
m, and the para-aromatic polyamide fiber was 37 cm. In addition, the strength and elongation of this yarn are 6.2 g/de and 5.6, respectively.
% (both measured after twisting at 400 T/m). Next, the yarn was twisted at 250 T/m and woven into a plain weave at a weave density of 89 warps/inch and weft 68 threads/inch, followed by heat setting and scouring. Next, using a pair of metal/elastic calender rollers with a metal roller surface temperature of 180° C., a woven fabric F1 was obtained which was subjected to hot pressure processing at a linear pressure of 400 kg/cm and a speed of 10 m/min. The resulting fabric F1 had a cover factor of 2719 and a fiber filling rate of 0.70.

Next, a yarn having a ratio of polyester fiber to para-aromatic polyamide fiber of 50:50 was obtained in the same manner. The average fiber length of polyester fiber is 45cm,
The para-aromatic polyamide fiber was 36 cm long. In addition, the strength and elongation of this yarn are 12.5g/de and 4.6%, respectively.
(All measurements were taken after twisting the yarn at 400 T/m). Next, the yarn was twisted at 250 T/m and woven into a 2/1 twill weave at a weave density of 40 warps/inch and weft 40 threads/inch, followed by heat setting and scouring. The resulting fabric F2 had a cover factor of 1385 and a fiber filling rate of 0.47.

When sewing two circular fabrics along their circumferences, this fabric F1 is used for the entire human body side and the steering side fabric F2 except for the fabric F2, and the fabric F2 is used for the remaining part of the steering side. An airbag as shown in FIG. 4 was sewn using the same method. No vent holes were made. In addition, the apron used was fabric F1.

Table 1 shows the evaluation results of the obtained airbag in comparison with its yarn and fabric. In the inflation test, neither fabric F1 nor fabric F2 had holes or damage in the bags, and they exhibited good inflation pressure and shape despite having no vent holes. Moreover, when folded, the shape was thin and the storage properties were extremely good.

[0051]

[Example 2] In the same manner as in Example 1, a stretch-cut yarn of 100% 200 denier para-aromatic polyamide fiber was obtained. The average fiber length of the yarn was 40 cm. In addition, the strength and elongation of this yarn were 22.3 g/de and 4.1%, respectively (both measured after twisting at 490 T/m). Next, the main yarn was twisted at 300T/m to create a warp of 112 threads/inch.
Plain weave with a weave density of 80 wefts/inch, heat set,
A scouring process was carried out. Next, the metal roller surface temperature is 1
Using a pair of metal/elastic calender rollers at 85° C., a woven fabric was obtained which was subjected to heat and pressure processing at a linear pressure of 440 kg/cm and a speed of 13 m/min. The resulting fabric F1 had a cover factor of 2715 and a fiber filling rate of 0.71.

Next, a stretch-cut yarn made of 100% para-aromatic polyamide fiber of 100 denier was obtained in the same manner. The average fiber length was 38 cm. In addition, the strength and elongation of this yarn are 21.5 g/de and 4.0% (both 690 g/de and 4.0%, respectively).
T/m measured after twisting). Next, the main thread is 250
It was twisted at T/m and woven into a 2/1 twill weave at a weave density of 98 warps/inch and weft 98 threads/inch, and was heat set and scoured. The resulting fabric F2 had a cover factor of 1960 and a fiber filling rate of 0.46. When sewing two circular fabrics along their circumferences, this fabric F1 is used for the entire human body side and the steering side fabric F2 except for the fabric F2, and the fabric F2 is used for the remaining part of the steering side. An airbag as shown in Fig. 4 was sewn using the following steps. No vent holes were made. Also, the apron is a textile F1
It was used.

Table 1 shows the evaluation results of the obtained airbag in comparison with its yarn and fabric. In the inflation test, neither fabric F1 nor fabric F2 had holes or damage in the bags, and they exhibited good inflation pressure and shape despite having no vent holes. Moreover, when folded, the shape was thin and the storage properties were extremely good.

[0054]

[Example 3] Using the method of Example 1, the ratio of polyester fiber to para-aromatic polyamide fiber is 70:30.
A prototype of 00 denier tension-cut thread was produced. The average fiber length was 42 cm for the polyester fiber and 37 cm for the para-aromatic polyamide fiber. In addition, the strength and elongation of this yarn were 8.2 g/de and 4.3%, respectively (both measured after twisting at 490 T/m). Next, the yarn was twisted at 250 T/m and woven into a plain weave at a weave density of 113 warps/inch and weft 78 threads/inch, followed by heat setting and scouring. Next, a pair of metal rollers with a surface temperature of 180° C.
Heat-pressing processing was performed using an elastic calender roller at a linear pressure of 400 kg/cm and a speed of 10 m/min to obtain a woven fabric F1. The resulting fabric F1 had a cover factor of 2701 and a fiber filling rate of 0.68.

[0055] Next, in the same manner, 2.
A stretch-cut yarn of 00 denier was obtained. The average fiber length was 49 cm for the polyester fiber and 38 cm for the para-aromatic polyamide fiber. In addition, the strength and elongation of each yarn is 1
They were 8.7 g/de and 4.1% (both measured after twisting at 690 T/m). Next, the main yarn was twisted at 250 T/m and woven into a 2/1 twill weave at a weave density of 39 warps/inch and weft 35 threads/inch, followed by heat setting and scouring. The resulting fabric F2 has a cover factor of 1046.
, the fiber filling rate was 0.35.

[0056] When sewing two circular fabrics along their circumferences, use this fabric F1 for the entire human body side,
An airbag as shown in FIG. 4 was sewn using the fabric F2 for the entire remaining steering side. No vent holes were made. In addition, the apron used was fabric F1.

Table 1 shows the evaluation results of the obtained airbag in comparison with its yarn and fabric. In the inflation test, neither fabric F1 nor fabric F2 had holes or damage in the bags, and they exhibited good inflation pressure and shape despite having no vent holes. Moreover, when folded, the shape was thin and the storage properties were extremely good.

[0058]

[Comparative example 1] Single yarn fineness 6 denier, strength 9.1 g/de
Filaments made of nylon 66 fibers having a total fineness of 840 denier were woven into a plain weave at a weave density of 25 warps/inch and weft 25 threads/inch. The obtained fabrics were designated as fabric F1 and fabric F2. The cover factor of this fabric is 1450
, the fiber filling rate was 0.55.

Next, chloroprene rubber was dissolved in toluene and coated on one side of the fabric F1. The amount of resin adhered to the obtained fabric F1 was 62% by weight. Also, fabric F2 was not coated.

When sewing two circular fabrics along their circumferences, this coated fabric F1 is used for the entire human body side and the steering side fabric F2 except for the fabric F2, and the fabric F2 is used for the steering side fabric F2. The remaining portion was used to sew an airbag as shown in FIG. No vent holes were made. In addition, the apron used was fabric F1.

Table 2 shows the evaluation results of the obtained airbag in comparison with its yarn and fabric. In the inflation test, a large melt hole was observed in the fabric F2 part of the bag, and the bag was severely damaged. Moreover, the shape when folded was thick and the storage properties were extremely poor.

[0062]

[Comparative Example 2] Using the method of Example 1, the ratio of polyester fiber and para-aromatic polyamide fiber was 70:30.
A prototype of 00 denier tension-cut thread was produced. The average fiber length was 42 cm for the polyester fiber and 37 cm for the para-aromatic polyamide fiber. In addition, the strength and elongation of this yarn were 8.2 g/de and 4.3%, respectively (both measured after twisting at 490 T/m). Next, the yarn was twisted at 250 T/m and woven into a plain weave at a weave density of 113 warps/inch and weft 78 threads/inch, followed by heat setting and scouring. Next, a pair of metal rollers with a surface temperature of 180° C.
Using an elastic calendar roller, linear pressure 400 kg/cm,
A woven fabric F1 was obtained which was subjected to heat-pressure processing at a speed of 10 m/min. The resulting fabric F1 had a cover factor of 2701 and a fiber filling rate of 0.68.

[0063] Next, in the same manner, a polyester fiber and a para-aromatic polyamide fiber with a ratio of 90:10 were prepared.
A stretch-cut yarn of 00 denier was obtained. The average fiber length was 49 cm for the polyester fiber and 37 cm for the para-aromatic polyamide fiber. In addition, the strength and elongation of each yarn is 5.
．． 2g/de, 5.9% (both measured after 490T/m twisting). Next, the yarn was twisted at 250 T/m and woven into a plain weave at a weave density of 25 warps/inch and weft 24 threads/inch, followed by heat setting and scouring. The resulting fabric F2 had a cover factor of 692 and a fiber filling rate of 0.39.

When sewing two circular woven fabrics along their circumferences, this woven fabric F1 is used for the entire human body side and the steering side fabric F2 except for the fabric F2, and the fabric F2 is used for the rest of the steering side side. Then, an airbag as shown in FIG. 4 was sewn. No vent holes were made. In addition, the apron used was fabric F1.

Table 2 shows the evaluation results of the obtained airbag in comparison with its yarn and fabric. In the inflation test, holes in the bag were seen throughout Fabric F2. Or it was slightly insufficient and did not show a sufficient expanded shape. However, when folded, the shape was thin and storage was extremely good.

[0066]

[Comparative Example 3] Fabric A similar to Comparative Example 2 was fabricated as a prototype.

Next, the fabric F1 prototyped in Example 1 was used here as fabric F2.

[0068] When sewing two circular fabrics along their circumferences, this fabric F1 is used for the entire human body side,
An airbag as shown in FIG. 4 was sewn using fabric F2 on the steering side. No vent holes were made. In addition, the apron used was fabric F1.

Table 2 shows the evaluation results of the obtained airbag in comparison with its yarn and fabric. In the inflation test, large holes in the bag were observed in fabric F1. However, the inflation pressure was sufficient and the inflation shape was good. Moreover, when folded, the shape was thin and the storage properties were extremely good.

[0070]

[Table 1]

[0071]

[Table 2]

[Brief explanation of the drawing]

[Figure 1] Side view of tension cutting type direct spinning device

[Figure 2] (a)
Schematic diagram of the air bag (front view) (b) Schematic diagram of the air bag (cross-sectional view) (c) Schematic diagram of the air bag (front view) (d) Schematic diagram of the air bag (cross-sectional diagram)

[Figure 3] (A) Schematic diagram showing how to fold the airbag when evaluating its storability (before folding) (B) Schematic diagram showing how to fold it when evaluating the storability of the airbag (after folding) ) Perspective view of the airbag after folding

[Figure 4]
How to measure the thickness of an airbag after folding

[Figure 5] Schematic diagram of the airbag device

[Explanation of symbols]

Claims (8)

[Claims] Claim 1: A cover factor of 1,500 or more, woven using yarn containing high-strength, heat-resistant fibers with a single yarn fineness of 2 de or less, a strength of 16 g/de or more, and a thermal decomposition temperature of 300° C. or more;
At least two types of fabric F1 having a fiber filling rate of 0.6 to 0.9 and a fabric F2 having a cover factor of 700 or more and a fiber filling rate of 0.3 to less than 0.6, which are woven using threads containing the same fibers. An airbag made of the above-described fabric and having no vent holes. Claim 2: Single yarn fineness 5de or less, Young's modulus 1300k
g/mm2 or less of thermoplastic synthetic fibers in the fabric F1.
2. The airbag according to claim 1, wherein the airbag comprises 0 to 90% by weight, and 0 to 90% by weight of the fibers mixed in the fabric F2. 3. The airbag according to claim 1, wherein the air permeability of the fabric F1 is lower than the air permeability of the fabric F2. 4. With the circumferential sewing area for forming the bag-like object as a boundary, the fabric F1 mainly occupies the bag-like object closer to the human body than the steering wheel, and the fabric F2 mainly occupies the bag-like object closer to the steering wheel than the human body side. The airbag according to any one of claims 1 to 3, wherein the airbag mainly occupies a shaped object. 5. The airbag according to claim 1, wherein the high-strength heat-resistant fiber is a para-aromatic polyamide fiber. 6. The airbag according to claim 1, wherein the thermoplastic synthetic fiber is polyester fiber. 7. The airbag according to claim 1, wherein the yarn is a tension-cut spun yarn produced by a tension-cutting method. 8. The fiber yarn according to any one of claims 1 to 7, which is obtained by tearing the fibers between a supply roller and a tension cutting roller while preventing disturbance of the fibers, and then conjugating them with an air nozzle. Any airbag.