JP2003213540A - Fabric and air bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fabric and an air bag excellent in air impermeability, flexibility, storage and mechanical characteristics. <P>SOLUTION: This fabric comprises filaments having 1.5-8 flatness (the length ratio of the major axis over the minor axis). This air bag is constituted of the fabric. In the cross section of the fabric, a horizontal index (HI) is ≥0.75 and the major axes of the flat cross sections of the filaments are arranged in the horizontal direction. The HI is expressed by sum total average of cosines (hi) of angles (θ) between the major axis direction of the filaments constituting the fabric and the horizontal direction of the fabric. This air bag is constituted by using the fabric. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin cloth having low air permeability, strength, heat resistance and flexibility, which is used for various non-clothing applications, paragliders, parachutes, tents, tarpaulins and airbags. The present invention relates to a fabric and an airbag suitable for use.

[0002]

2. Description of the Related Art In recent years, airbags have become indispensable as a device for ensuring the safety of passengers in a vehicle, and the rate of attachment to the vehicle is increasing.

[0003] Further, demands for improving reliability of airbags as safety devices have been further strengthened, and further, there are demands for downsizing of airbag devices, prevention of occupant's facial scratches when a bag is deployed at the time of collision, cost reduction, and the like. It is getting stronger and stronger. For this reason, further improvements are required in the manufacturing processes of the airbag base fabric, airbag raw yarn, and fabric constituting the airbag so as to satisfy the above requirements.

So far, there has been disclosed a technique for realizing an airbag which is excellent in foldability and has a small storage volume without impairing the mechanical characteristics of the airbag base fabric. Above all, the technique of using a fabric using a modified cross-section yarn as a base fabric for an airbag is noted because it can satisfy the performance required for a next-generation airbag such as safety and storability.

As a conventional technique using a modified cross-section yarn, Japanese Patent Laid-Open Nos. 4-193647 and 4-201650 are known.
Japanese Patent Application Laid-Open No. 7-252740, Japanese Patent Application Laid-Open No. 8-60425, and the like.

Japanese Unexamined Patent Publication No. 4-193647 and Japanese Unexamined Patent Publication No. 4-201650 have a single yarn fineness as a base fabric for an airbag which is lightweight, excellent in flexibility and storability, and excellent in mechanical properties. A base fabric for an airbag using a polyamide multifilament composed of a plurality of single yarns having a deformed cross section including a flat shape having a flatness of 1.0 to 12 denier and a single yarn deformation degree of 1.5 to 7.0 is disclosed. There is. However, the technique is described on the premise of a so-called coated base fabric in which an elastomer such as silicone rubber is applied to the surface of the fabric, and when the technique is applied to a non-coated base fabric, flexibility, storability, and mechanical properties are obtained. However, there is still a problem in that it has low air permeability, which is one of the most important properties as an airbag, although it has excellent dynamic properties.

On the other hand, as a technique relating to a non-coated base cloth using a modified cross-section yarn, there is a method described in JP-A-7-252740. The publication describes that a non-coated airbag base cloth having low air permeability, high storability, and mechanical properties can be obtained by using a flat cross section yarn having an oblateness of 1.5 or more. However, in this technology, the air flow rate under 124 Pa is 0.3 cc / cm ² / sec or more,
It has not been possible to fully satisfy the lower air permeability required in recent years.

Further, in Japanese Unexamined Patent Publication No. 8-60425, there are 1 to 3 symmetrically provided convex portions composed of substantially semicircular projections in the longitudinal direction of the flat base in the cross section of the single yarn,
Disclosed is an airbag fiber in which the ratio of the long axis to the short axis of the flat cross section yarn is 4/1 to 2/1, the single yarn fineness is 2 to 10 denier, and the strength is 7 g / d or more. . The fiber having the protrusion has good spinnability and quality, and
The fabric for an airbag obtained by using the fiber has flexibility,
It is said to be excellent in compactness. However, although there is no description about air permeability, which is an important property for airbag fabrics, since the single yarn cross section has a protrusion, the packed state of the single yarns does not become dense, that is, there is a gap between the single yarns. As a result, it is presumed that a problem remains in terms of breathability.

[0009]

As described above, in the prior art, a fabric having all the properties required for an airbag base fabric, such as low air permeability, flexibility and storability, and mechanical properties, has been obtained. There wasn't. Further, it has become more difficult to provide a fabric that can sufficiently satisfy the recent demands for more strict low air permeability.

The present invention has been made in view of such background of the prior art.
An object of the present invention is to provide a fabric and an air bag having low air permeability, flexibility, storability and mechanical properties.

[0011]

The present invention employs the following means in order to solve such problems. That is, the cloth of the present invention is a cloth composed of a flat cross-section filament yarn having a cross-sectional shape in the range of flatness (ratio of the length of the long axis to the length of the short axis) of 1.5 to 8. In the cross section, the cosine (h) of the angle (θ) formed by the long axis direction of the filaments forming the fabric and the horizontal direction of the fabric
The horizontality index (HI) represented by the sum average of i) is 0.75.
As described above, the long axis of the flat cross section of the filament is arranged in the horizontal direction of the fabric.

The airbag of the present invention is characterized by being constructed by using such a cloth.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention has been made in consideration of the above-mentioned problems, that is, a fabric excellent in low air permeability, flexibility, storability and mechanical properties, and has a flat cross section filament yarn having a specific oblateness. , A horizontality index (HI) of 0.75 or higher
Moreover, when the long axis of the flat cross section of the filament yarn is arranged in the horizontal direction of the fabric, it has been clarified that the above problems can be solved all at once.

The cloth of the present invention is a cloth made of synthetic fibers such as polyamide fiber, polyester fiber, polyolefin fiber, polyvinyl alcohol fiber and the like, and is not particularly limited, but high strength and high toughness fibers are used. In order to obtain the fiber, a fiber made of polyamide having a sulfuric acid relative viscosity of 3.0 or more is preferable. Further, the fiber may be a homopolymer or may contain a copolymerization component, and in the polymer, for the purpose of improving weather resistance, oxidation resistance, etc., titanium oxide, silicon oxide, calcium carbonate, etc. Inorganic substances, agents such as weathering agents, and antioxidants may be included.

The cross-sectional shape of the single fiber of the fiber used in the cloth of the present invention is usually an elliptical shape as shown in FIG.
Although the opposite sides are parallel to each other as shown in (a), the sides are parallel to each other, but any shape other than the ellipse can be used as long as it satisfies the relationship between the major axis and the minor axis.
For example, it may be a left-right symmetrical type such as a rectangle, a rhombus, or a cocoon type, or may be a left-right asymmetric type, or a combination type thereof. Further, using the above as a basic type, protrusions, dents, or hollow portions may be present within the range that does not impair the effects of the present invention.

In the flat cross-section yarn according to the present invention, it is essential that the cross-sectional shape of the single yarn has an oblateness (ratio of the lengths of the major axis and the minor axis) of 1.5 to 8, preferably 2 to 6. Is. By using the flat cross-section yarn in such a range, the long axis of each single yarn can be arranged in the horizontal direction of the base fabric, and the thickness of the obtained fabric can be increased as compared with the case of using a normal round cross-section yarn. Is thin and excellent in storage, and also has low breathability. When the oblateness is less than 1.5, it is close to a round cross section yarn,
It becomes impossible to obtain the effect of using the flat cross section yarn, that is, the fabric having low air permeability, flexibility and storability.
On the other hand, if the flatness ratio exceeds 8, the effect of using the flat cross-section yarn is saturated, and it becomes difficult to stably produce high-strength, high-toughness fibers with good quality.

In a general round cross section yarn, the smaller the single yarn fineness is, the more the covering property on the fabric is improved, and the flexibility and the storability of the obtained fabric are improved. However, on the other hand, there arises a problem that the yarn formability is deteriorated as the fineness of the single yarn is reduced. In other words, in consideration of productivity, there is a limit to the effect of improving the flexibility and storability by making the single yarn finer.

On the other hand, the above-described flat cross-section yarn can sufficiently obtain the single-filament fineness effect in the round cross-section yarn without reducing the actual single yarn fineness. This means that, for example, the short axis of a polyamide yarn having a flat cross section with an oblateness of 3.5 and a single yarn fineness of 10 dtex has a single yarn fineness of 2.4 d.
This is due to the fact that it corresponds to the diameter of the round cross section yarn of tex. Furthermore, for example, the minor axis length of a flat cross-section yarn having an oblateness of 3.5 and a single yarn fineness of 4 dtex corresponds to a so-called microfiber diameter of a single yarn fineness of 1 dtex or less, which is usually difficult to stably produce. In other words, when the flat cross section yarn is used, it is possible to expect a single-filament fineness effect that is difficult to obtain with the round cross section yarn.

The flat cross section yarn of the present invention has a strength of 7 to 10 cN.
/ Dtex, elongation 10-30%, boiling water shrinkage 3-8%
Is preferable, and by using a synthetic fiber having the physical properties, a fabric having excellent mechanical properties such as tensile strength and tear strength can be obtained.

In the cloth of the present invention, the cross-sectional shape of each filament is a flat cross-section yarn having the above-mentioned flatness, and the long axis direction of each filament constituting the cloth is arranged in the horizontal direction of the cloth. That is the biggest and most important feature. In order to express this quantitatively, a horizontal index (HI) was defined. The horizontality index HI is the cosine (hi) of the angle (θ) formed by the long axis direction of each filament constituting the cloth and the horizontal direction of the cloth, and is represented as the sum total average thereof. That is, it can be calculated by the following formula.

HI = (Σhi) / f hi = cos θ θ: The angle between the long axis direction of each filament and the horizontal direction of the fabric f: The number of filaments The levelness index HI for the fabric using the flat cross-section yarn of the present invention. Is 0.75 or more, preferably 0.85
Or more, more preferably 0.90 or more. By setting the levelness index HI within this range, it is possible to obtain a fabric having excellent flexibility and storability and low air permeability. When the HI is less than 0.75, the effect of the present invention, that is, low air permeability, flexibility and storability due to good covering properties are not sufficiently exhibited even if a flat cross section yarn is used. Further, the fact that the HI is 0.75 or more means that the long axis direction of each filament is effectively arranged in the horizontal direction of the cloth.

The cover factor of the fabric of the present invention is 170.
It is preferably 0 to 2400. Here, the cover factor means the total fineness of the warp yarns D ₁ (dtex), the weaving density N ₁ (books / 2.54 cm), and the total fineness of the weft yarns D ₂ (dt).
ex) and the weave density is N ₂ (books / 2.54 cm), (D ₁ × 0.9) ^1/2 × N ₁ + (D ₂ × 0.9) ^1/2 ×
It is a value represented by N ₂ . The cover factor is greatly related to the air permeability and storability of the fabric, and it is extremely important that the cover factor is in an appropriate range as a base fabric for an airbag. In addition,
Since the cloth of the present invention has a flat cross-sectional shape of each filament, and the long axis direction of the filaments is arranged in order in the horizontal direction of the cloth, the covering property is good,
Cover factor of 1 compared to fabrics using ordinary round cross-section yarn
The feature is that low air permeability can be secured even if it is 0 to 30% lower. If the cover factor can be set low, that is, the amount of fibers used can be reduced and the weaving time can be shortened, so that the cost of the entire fabric can be reduced.

The fabric of the present invention is characterized by having both low air permeability, flexibility and storability.
Air permeability (A) under pressure of 24 Pa is 0.1 cc / cm
The air permeability (B) under a pressure of ² / sec or less and 19.6 KPa is preferably 10 cc / cm ² / sec or less. By achieving low air permeability under all pressures in this manner, the deployment speed of the airbag is increased when the fabric is used as the airbag, and the occupant safety can be secured with a higher probability. . The fabric of the present invention can achieve low air permeability because the flat cross-section filaments are arranged in the horizontal direction of the fabric in an orderly manner, whereby the gap in the vertical direction of the fabric is extremely reduced.

The fabric preferably has a thickness of 0.20 to 0.35 mm, and can be suitably used as a fabric for storing in a narrower space, for example, a fabric for an airbag of a small car or less. The fabric of the present invention uses flat cross-section yarns having an oblateness of 1.5 to 8 and has a structure in which the long axis of the cross section of each filament is arranged in the horizontal direction of the fabric in an orderly manner. When comparing the thickness of a cloth made of threads having the same cover factor with a circular cross section, it is possible to reduce the thickness by about 15% or more.

Regarding the mechanical properties of the cloth of the present invention, it is preferable that the tensile strength is ≧ 500 N / cm and the tear strength is ≧ 150 N because the reliability as a cloth for various non-clothing materials is increased. In particular, a fabric for an airbag needs to have high strength enough to withstand an impact force when the bag is deployed. The fabric having a strength within the above range can be applied to any fabric for airbags, that is, any of a driver seat airbag, a passenger seat airbag, a side airbag, and an inflatable curtain airbag.

The cloth of the present invention is characterized in that the tear strength is relatively higher than the tensile strength as compared with the cloth having a normal round cross-section yarn, and tears, holes, etc. generated in the cloth due to an impact may occur. It is effective in preventing damage from propagating one after another on the fabric. In the fabric of the present invention, the flat cross-section yarns are bundled and packed in a very high density and woven, so that they behave as if they were a single flat monofilament.
It is speculated that high tear strength may develop.

Next, an example of a method for producing the fabric of the present invention will be described.

As the synthetic fiber having a flat cross section used in the fabric of the present invention, fibers made of various polymers can be used as described above, but polyamide fibers are preferable in order to obtain fibers having high strength and high toughness. In particular, a highly viscous nylon 66 polymer having a sulfuric acid relative viscosity of 3.0 to 4.0 is preferably used.

The polymer is melted, filtered, and then spun out from the pores of the die, and the die is designed so that each filament has a flat cross section as specified in the present invention. In particular, the die hole shape is designed in consideration of the change in cross-sectional shape due to the surface tension of the molten polymer until the yarn is spun and cooled and solidified.

For example, in order to obtain the fiber having the elliptical shape shown in FIG. 1A, the die discharge shape may be designed to have a rectangular shape as shown in FIG. The vertical length c and the horizontal length d of the rectangle may be appropriately set depending on the single yarn fineness and flatness of the fiber to be obtained. On the other hand, in order to make the single yarn cross section into an elliptical shape in which the opposite sides are parallel to each other as shown in FIG. 1 (A), circular holes are arranged at both ends and inside, as shown in FIG. 2 (A). It may be designed so that the circular holes are connected by slit holes. In this case, regarding the number of round holes, the diameter of the round holes, the length of the slit holes, the width of the slit holes, and the overall length c, width d, etc., the single yarn fineness of the fiber to be obtained , May be appropriately selected according to the flatness. The number of round holes is 4-8, the diameter is 0.1-0.
3 mm, slit width 0.1-0.3 mm, length 0.1
It is advantageous to be in the range of ~ 0.3 mm.

After the spun yarn is cooled and solidified, an oil agent is applied, and the spun yarn is wound and taken up by a take-up roller which rotates at a predetermined rotation speed. Then, the yarn is continuously wound as it is and wound around a Nelson roller which rotates at high speed, to perform drawing. In order to obtain a fiber having higher strength, it is preferable to perform multi-stage drawing of two or more stages. Further, it is preferable to set the final drawing roller temperature at 200 ° C. or higher and subject it to a heat treatment for drawing, and then subject it to a relaxation treatment and wind it up in order to obtain fibers having appropriate shrinkage properties. Along with the improvement of the yarn production efficiency, the winding speed is 2500 to 4500 m / min and the simultaneous drawing of 4 to 8 yarns is carried out by the direct spinning and drawing method.

Usually, the entanglement treatment is performed to impart the tying property to the yarn before winding. The entanglement process is performed by injecting high-pressure air from a plurality of nozzle holes in a direction intersecting the running yarn. The greater the number of entanglements, the more the yarns are in a bundled state, and the better the processability in warping and weaving, which is preferable. On the other hand, however, it is preferable that the entanglement imparted to the yarn is released after weaving, and the number of yarn entanglements in the fabric is substantially small. If many entanglements remain in the fabric, the filaments are often twisted in some places, and the specific horizontality index HI, which is an important requirement in the present invention, may not be obtained. The preferred number of entanglements imparted to the fiber according to the present invention is 3 to
The number is 20 / m, more preferably 5 to 15 / m, still more preferably 5 to 10 / m. The number of entanglement of the fibers in the cloth is preferably 3 / m or less. By setting the number of entanglements in such a range, the HI of the fabric made of the fibers can be sufficiently increased without impairing the process passability in warping and weaving, and strong production of a thin base fabric with low air permeability is possible. You will be able to get it by sex.

Next, the obtained fiber is warped and woven. In the weaving process, the warp tension is appropriately set so that the flat cross-section filaments according to the present invention are aligned in the horizontal direction of the fabric, and the weft driving tension is controlled appropriately. The appropriate warp tension range is 0.1 to 0.
6 cN / dtex. Warp tension during weaving is 0.1c
When it is less than N / dtex, the levelness index (HI), which is an important requirement of the present invention and which indicates the arrangement state of the flat cross-section filaments in the cross section of the fabric, is not sufficiently high and is excellent in storability and low air permeability. It becomes impossible to obtain a good cloth. On the other hand, even when the warp tension exceeds 0.6 cN / dtex, the levelness index (HI) tends to decrease, and it becomes impossible to obtain a fabric having both storability and low air permeability.
Further, if the tension during weaving is too high, single yarn breakage and full yarn breakage will occur, and the weaving machine will be stopped, which is disadvantageous in terms of quality and productivity.

A lot of water jet looms are used for the loom, but not limited to rapier looms and air jet looms. The woven structure of the cloth is usually plain weave, but any structure such as twill weave may be used.

Subsequently, the cloth is scoured, calendered,
It is preferable to perform heat set processing, but these may be plural or may be independent.

Although the embodiments of the present invention have been described in detail above, in the present invention, fibers having a specific cross-sectional shape,
And designing a fabric having a specific structure, that is, the cross-sectional shape of each filament has an oblateness of 1.
5 to 8 flat cross-section yarns are used, and the long axis direction of each filament is arranged in order in the horizontal direction of the fabric.
A fabric having low air permeability, flexibility and storability can be obtained.

Further, the flat cross section yarn and the cloth can be obtained with high productivity without the need of using a special method or apparatus, which is extremely practical.

[0038]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples.

The methods of measuring the physical properties shown in the text of the specification and the examples are as follows. <Original yarn characteristics> [Flatness]: A cross section of the fiber is photographed at a magnification of 200, and the lengths of the long axis (a) and the short axis (b) of the single yarn are measured,
The ratio was defined as flatness. Ten single yarns were measured and shown as an average value.

Flatness = a / b [Total fineness]: Positive amount fineness according to JIS L-1013
Was measured. [Single yarn fineness]: Calculated by dividing the total fineness by the number of filaments
did. [Strength, Elongation]: Test length according to JIS L-1013
Measured under the conditions of 25 cm and a pulling speed of 30 cm / min.
It was [Boiling water shrinkage rate]: Sampling the raw yarn in a maze shape
24 hours or more in a temperature and humidity control room at 20 ° C and 65% RH
Adjust and apply a load equivalent to 1 cN / dex to the sample to length L ₀To
It was measured. Next, this sample was placed in boiling water without tension 3 times.
After soaking for 0 minutes, air-dry for 4 hours in the greenhouse regulation room,
Apply a load equivalent to 1 cN / dex to the sample again, and length L₁Measure
did. Each length L₀And L₁From the following formula boil
The water shrinkage ratio was determined.

Boiling water shrinkage ratio = [(L ₀ −L ₁ ) / L ₀ ] × 100 (%) [entanglement number]: The number of entangled portions having a length of 1 mm or more was measured by a water immersion method, and per 1 m Converted to the number of pieces. Yarn 10
The book was measured and the average value was shown.

The immersion bath has a length of 70 cm and a width of 15 cm.
A partition plate having a depth of 5 cm and located 10 cm from both ends in the longitudinal direction was used. Fill this bath with pure water,
The raw yarn sample was immersed in water and the number of entangled portions was measured. The pure water was replaced for each measurement in order to eliminate the influence of impurities such as oil. [Number of Entanglements in Fabric]: (Sampling Method): The warp yarns in the fabric were picked one by one and pulled out in a direction of 20 to 45 degrees with respect to the warp direction at a speed of 40 to 60 sec / m. Similarly, the weft was drawn and sampled at a speed of 40 to 60 sec / m in the direction of 20 to 45 degrees with respect to the weft direction.

(Measurement method): Measurement was carried out by the same water immersion method as the above-mentioned entanglement number, and both warp and weft were shown as an average value of 10 threads. <Cloth characteristics> [Cover factor]: Total fineness of warp D ₁ (dte
x), weaving density N ₁ (pieces / 2.54 cm), total fineness of weft D ₂ (dtex), and weaving density N ₂ (pieces / 2.54 cm) were calculated by the following formula.

Cover factor = (D ₁ × 0.9) ^1/2
× N ₁ + (D ₂ × 0.9) ^1/2 × N ₂ [Horizontal index HI]: A photograph was taken in the same manner as the flatness measurement, and the major axis of the flat cross-section filament was the horizontal direction of the fabric on the photograph. The angle (θ) formed with each filament was measured for each filament.
The cosine value (hi) of the measured angle was obtained, and the average of the sums thereof was used as the horizontality index (HI).

Horizontalness index HI = (Σhi) / f hi = cos θ θ: Angle between the long axis direction of each filament and the horizontal direction of the fabric f: Number of filaments Normally, it is preferable to measure every filament,
When the number of filaments is 100 or more, it will be 100 at random.
The value measured by selecting the filament was used. [Tensile Strength]: JIS L1096 (6.12.1A)
Method). [Tear strength]: JIS L1096 (6.15.2A)
-2 method), and the average value in the warp direction and the weft direction was obtained. [Aeration amount (A)]: JIS L1096 (6.27.
1A method).

The details are 20 cm in length and 15 cm in width.
In the fabric sample of No. ^{2, the} amount of air passing through (cc / cm ² ) when air adjusted to a pressure of 124 Pa was passed through a circular portion having a diameter of 10 cm using a laminar flow type air permeability measuring device.
/ Sec) was measured. [Ventilation amount (B)]: When air adjusted to a pressure of 19.6 KPa was applied to a circular portion having a diameter of 10 cm in a fabric sample having a length of 20 cm and a width of 15 cm by using a laminar flow tube type air permeability measuring instrument. Amount of air passing through (cc / cm ²
/ Sec) was measured. [Fabric Thickness]: Measured according to JIS L1096 (6.5). [Hardness]: JIS L1096 (6.19.1A method)
It measured according to. [Airbag thickness (bag storability)]: Weaving an airbag with a capacity of 60 liters, first fold it into a bellows four times from the left and right directions so as to have an area of 150 x 150 mm, and then from the vertical direction. Each bag was folded into a bellows four times, and a load of 4000 g was applied to the folded bag, and the thickness of the bag at that time was measured.

[Examples 1 to 8 and Comparative Examples 1 to 4] Nylon 66 pellets having a 98% sulfuric acid relative viscosity of 3.7 measured at 25 ° C were fed to an extruder and placed on a spinneret by a lightweight pump to obtain 295. Melt-spun at 0 ° C. The spinneret is
The number of holes, the shape of the holes, the size of the holes, etc. were appropriately designed in order to obtain yarns having different fineness, number of filaments, and oblateness with respect to the flat cross section yarn and the round cross section yarn.

Immediately below the base, 250 m heated to 300 ° C.
A heating cylinder of m was provided, and the yarn was gradually cooled, and then cooled and solidified by cold air. Then, an aqueous emulsion was applied, and the yarn was wound on a spinning take-up roller to take out the spun yarn. Subsequently, the yarn was continuously supplied to the drawing / heat treatment zone, and nylon 66 fiber was manufactured by the direct spinning drawing method.

First, a stretch of 3% is applied between the take-up roller and the yarn feeding roller, then the first drawing is performed between the yarn feeding roller and the first stretching roller, and the first stretching roller and the second stretching roller are stretched. The second stage drawing was performed between. Subsequently, a relaxation heat treatment of 7% was performed between the second stretching roller and the relaxation roller, the yarn was entangled by an entanglement imparting device, and then wound by a winder. As for the surface temperature of each roller, the take-off roller is at room temperature, the yarn feeding roller is 40 ° C., the first drawing roller,
The second stretching roller was set to 140 ° C. and 230 ° C., and the relaxation roller was set to 150 ° C. The peripheral speed of each roller is constant at 3200 m / min for the first drawing roller and 4000 m / min for the second drawing roller. For the take-up roller and the yarn feeding roller, according to the single yarn fineness and the cross-sectional shape of the single yarn, Each was changed and set. The entanglement treatment was performed by injecting high-pressure air from the direction perpendicular to the running yarn in the entanglement imparting device. The pressure of the air to be injected is 0.05 ~
It was changed in the range of 0.4 MPa to change the number of yarn entanglements.

The properties of the obtained nylon 66 fiber are shown in Table 1.

Next, 30 kinds of the obtained nylon 66 fibers were used.
The diameter is adjusted at a speed of 0 m / min, and then the weaving density is adjusted using a water jet loom (ZW303) manufactured by Tsuda Koma so that the number of warp and weft threads is 48 (threads / 2.54 cm). Weaving was performed at 1000 rpm to obtain a raw fabric. Then, the greige is dried at 110 ° C.
A heat treatment was performed at 1 ° C. for 1 minute to obtain a fabric. The fabric design and fabric properties are shown in Table 1.

Next, using the obtained cloth, a base cloth for an air bag was prepared.

First, two circular fabrics having a diameter of 725 mm are cut by a punching method, and three circular reinforcing fabrics having a diameter of 200 mm made of the same fabric are laminated in the central portion of one circular fabric to have a diameter of 110 mm. Nylon 66 composed of 470 dtex / 1 x 3 on the circumference of 145 mm and 175 mm
Sewing was performed by lock stitching with the sewing thread made by the manufacturer. Further, a hole having a diameter of 90 mm was provided in the cloth to serve as a mounting port for the inflator. Next, one piece of circular reinforcing cloth made of the same cloth having a diameter of 75 mm is placed against each other at a position of 225 mm in the bias direction from the center part, and 4 pieces are placed on the circumference of 50 mm in diameter and 60 mm in circumference.
A sewing thread made of nylon 66 composed of 70 dtex / 1 × 3 was sewn by a lock stitch to form a hole having a diameter of 40 mm and two vent holes were formed. Finally, the reinforcing cloth side of this circular cloth is placed outside, and the other circular cloth and the shaft are
Offset by 5 degrees and overlap, diameter 700mm, 710mm
The sewing machine was sewn by double stitching on the circumference of 1400 dtex / 1 with a sewing thread made of nylon 66, and the bag was turned inside out to produce an airbag having a capacity of 60 liters.

Table 1 also shows the thickness of the obtained bag air bag (bag storability).

[0055]

[Table 1]

As is clear from the results shown in Table 1, the fabrics using the flat cross-section yarns of Examples had extremely low air permeability and, at the same time, were excellent in flexibility, storability and mechanical properties.
In addition, a fabric having the above-mentioned characteristics can be suitably used as a fabric for an air bag, from the viewpoints of safety reliability and storability.

On the other hand, the fabrics of Comparative Examples 1 to 3 in which the cross-sectional shape of the raw yarn and the structure of the fabric are outside the scope of the present invention, the air permeability cannot be lowered sufficiently, and the flexibility and the storability are also improved. It was inferior to the product of the present invention. Further, in Comparative Example 4 in which the flatness of the cross section of the single yarn was designed to be 9, the yarn breakage occurred frequently and the nylon 66 fiber could not be obtained.

[0058]

EFFECTS OF THE INVENTION According to the present invention, low air permeability and excellent storability, that is, compactness, good mechanical properties,
It also has heat resistance and the like, and can be suitably used for various non-clothing applications, for example, airbags, paragliders, parachutes, tents, tarpaulins, and the like.
It is possible to provide an airbag having excellent safety and being capable of being mounted in a narrow space.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the fiber shape of a flat cross-section filament single yarn of the present invention.

FIG. 2 is a schematic cross-sectional view showing a die discharge hole shape for obtaining a flat cross-section filament single yarn of the present invention.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3D054 AA02 AA03 AA06 CC26 EE20                       FF01 FF03 FF13 FF16 FF18                       FF20                 4L048 AA24 AA37 AA48 AA49 AA50                       AC09 AC10 AC11 CA01 CA11                       CA15 DA03 DA25 DA27

Claims (6)

[Claims] 1. A fabric comprising a flat cross-section filament yarn having a cross-sectional shape within a flatness ratio (ratio of lengths of major axis and minor axis) of 1.5 to 8, wherein the cross section of the fabric is The horizontality index (HI) represented by the sum average of the cosine (hi) of the angle (θ) formed by the long axis direction of the filaments constituting the fabric and the horizontal direction of the fabric is 0.75 or more, and A fabric characterized in that the long axis of the flat cross section of the filament is arranged in the horizontal direction of the fabric. 2. The cloth according to claim 1, wherein the cloth has the following characteristics (1) to (6). (1) Cover factor: 1700 to 2400 (2) Tensile strength ≧ 500 N / cm (3) Tear strength ≧ 150 N (4) Air permeability (A) ≦ 0.
1 cc / cm ² / sec (5) Air permeability (B) ≦ 10 under pressure of 19.6 KPa
cc / cm ² / sec (6) Fabric thickness: 0.20 to 0.35 mm 3. The number of intertwined filament yarns having a flat cross section is 3.
The fabric according to claim 1 or 2, wherein the number of entanglements of the flat cross-section yarns in the fabric is ~ 20 yarns / m and 3 or less. 4. The fabric according to claim 1, which is used for any one selected from paraglider, parachute, tent and tarpaulin. 5. An airbag constructed using the cloth according to any one of claims 1 to 3. 6. The airbag according to claim 5, wherein the filament yarn having a flat cross section constituting the cloth is made of polyamide fiber.