JP2007023410A - Ground fabric for airbag and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground fabric for airbag having low air permeability while keeping high mechanical properties characteristic to a rip-stop texture and a method for producing the fabric. <P>SOLUTION: The ground fabric for airbag is a woven fabric of a synthetic fiber having a ripstop texture at intervals of 1.0-10.0 cm. The tearing strength of the ground fabric is higher than that of a woven fabric made of exclusively the ground yarn constituting the ground fabric by ≥5% in both longitudinal direction and lateral direction, and the air permeability of the fabric is ≤1.20 L/cm<SP>2</SP>/min measured under a test pressure difference of ΔP=19.6 kPa. The ground fabric for airbag is produced by using a synthetic fiber having a boiling water shrinkage of 2-15% in the form of woven fabric, weaving the fiber to obtain a synthetic fiber fabric having ripstop textures placed at intervals of 1.0-10.0 cm, and shrinking the fabric in water at 60-140°C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air bag base fabric having a low air permeability while maintaining high mechanical characteristics peculiar to a ripstop structure in an air bag which is one of safety devices for automobiles, and a method for manufacturing the same.

  In recent years, as an automobile safety component, an airbag has been rapidly installed with an improvement in the safety awareness of passengers. In the event of an automobile collision, an air bag detects an impact by a sensor, generates high-temperature and high-pressure gas from an inflator, and rapidly deploys the air bag with this gas to help protect passengers.

  Conventionally, a high-density plain woven fabric using polyamide fiber yarns having a total fineness of 300 to 1000 dtex has been used as a base fabric for an uncoated airbag. Some plain woven fabrics have been used by applying and laminating an elastomer resin such as chloroprene and silicone, in order to improve heat resistance, flame retardancy, and air barrier properties.

  However, when plain woven fabric is used as the base fabric for non-coated airbags, in addition to the air permeability from the surface of the base fabric, low tearing strength causes air leakage due to misalignment of the sewing parts when the airbag is deployed, and this occurs from the inflator There was a problem such as not being able to use the air effectively. In addition, when the coated base fabric is used, the air permeability from the surface of the base fabric, which is a disadvantage of the non-coated airbag base fabric, is almost zero, but the misalignment for low tear strength still occurs. Measures such as applying a sealant to the part have been taken. Due to these measures, the weight of the base fabric was increased, the flexibility was lowered, the manufacturing cost was increased, and recycling was not possible.

  Therefore, Patent Document 1 discloses a manufacturing method for improving air permeability by performing shrinkage treatment in a water bath in a non-coated airbag base fabric. The tear strength, which is an index indicating deviation, has not yet been improved, and the ventilation from the sewing portion is still not a satisfactory non-coated airbag fabric.

Further, in Patent Document 2, the fabric is coated with a synthetic resin to improve the air permeability from the surface of the base fabric, and by using a ripstop structure, the fraying at the time of cutting and sewing is improved. An airbag base fabric that improves low air permeability has been disclosed, but since synthetic resin is applied, problems such as an increase in the weight of the fabric, a decrease in flexibility, an increase in manufacturing costs, and inability to recycle are also present. There were many.
Further, Patent Document 3 discloses a technique for improving bag storage performance in a non-coated airbag base fabric. Preferably, by weaving into a ripstop structure, the degree of freedom of the woven structure is increased. There is a technical disclosure that flexibility is improved. Certainly, the ripstop structure increases the degree of freedom of the weave structure and improves the flexibility, but at the same time the air permeability increases, resulting in inferior performance in restraining the occupant when the airbag is deployed. However, there is no disclosure of technical means for reducing the air permeability while the air permeability is increased by weaving into a ripstop structure.
Japanese Patent No. 2556624 JP-A-11-293541 Japanese Unexamined Patent Publication No. 2000-211459

  In view of the shortcomings of such conventional airbags, the present invention is to provide an airbag base fabric having a low air permeability while maintaining the high mechanical characteristics unique to the ripstop structure, and a method for producing the same. .

The present invention employs the following means in order to solve such problems. That is, the airbag base fabric of the present invention is a synthetic fiber fabric having a ripstop structure at an interval of 1.0 to 10.0 cm, and against the tearing strength of a fabric consisting of only the ground yarn constituting the fabric. The tear strength is 5% or more in both the vertical and horizontal directions, and the air permeability of the woven fabric is 1.20 L / cm ² / min or less when measured at a test differential pressure ΔP = 19.6 kPa. It is characterized by this.
Moreover, the manufacturing method of the base fabric for airbags of this invention uses a synthetic fiber which has a boiling-water shrinkage of 2-15% in the state of textile fabric, and a ripstop structure | tissue is carried out at intervals of 1.0-10.0 cm. The synthetic fiber fabric woven in the form of having a shrinkage treatment in a water bath within a temperature range of 60 to 140 ° C.

  According to the present invention, since it is possible to provide an airbag base fabric having a low air permeability while maintaining the high mechanical characteristics unique to the ripstop structure, it is possible to promote the spread of an occupant protection system using airbags. Can do.

  In the present invention, the above-mentioned problem, that is, a base fabric for an air bag having a low air permeability while maintaining high mechanical characteristics peculiar to the ripstop structure, has been intensively studied, and ripstop is performed at intervals of 1.0 to 10.0 cm. When the synthetic fiber fabric having a structure was contracted with boiling water, it was found that such problems could be solved at once.

  That is, the present invention is characterized in that the airbag fabric having a ripstop structure is further contracted with boiling water to firmly fix the ripstop structure portion.

  Therefore, it is important that the synthetic fiber used in the airbag fabric is one that induces a boiling water shrinkage of 2 to 15% in the woven fabric state. When the boiling water shrinkage is larger than 15%, the shape stability of the fabric is inferior, which is not preferable in terms of environmental resistance, that is, heat resistance, moist heat resistance, and the like. On the other hand, when the boiling water shrinkage rate is less than 2%, even if the woven raw machine is subjected to a water bath treatment at 60 to 140 ° C., sufficient shrinkage does not occur and the air permeability may be increased. In addition, it may cause fuzz due to yarn breakage or single yarn breakage during the drawing process during the production process of synthetic fibers, impairing the strength and elongation characteristics of the synthetic fibers, and improving the operability during fiber production and the process passability during weaving of fabrics. There is a risk of deterioration of fabric quality due to deterioration and single yarn breakage.

  Such a synthetic fiber is not particularly limited as long as it has such a shrinkage rate. For example, a synthetic fiber made of a material such as polyolefin, polyamide, polyester, polyacrylonitrile, or a copolymer thereof can be used. Among them, heat resistance or amine resistance so that a vehicle equipped with an air bag can withstand any environment that is normally used on the earth, for example, a high temperature area such as a desert area or an environment where chemicals are loaded and used. A polyester-based synthetic fiber made of polyester excellent in the above or a copolymer thereof is preferably used practically.

  Such synthetic fibers may contain various additives usually used for improving the productivity or properties in the production process and processing process of the raw yarn. For example, a heat stabilizer, an antioxidant, a light stabilizer, a smoothing agent, an antistatic agent, a plasticizer, a thickener, a pigment, a flame retardant, and the like can be contained.

  The total fineness of the woven yarn constituting the airbag fabric of the present invention is preferably in the range of 200 to 600 dtex in view of tear strength and air permeability. Such a woven yarn means a ground yarn and the following ripstop yarn.

  The air bag base fabric of the present invention is one in which the ripstop tissue portion is firmly fixed by shrinking with boiling water by 2 to 15% in the state of the woven fabric. What has a space | interval of 10.0 cm is important from the viewpoint of reducing the tearing strength and air permeability of the woven fabric, and further the shift of the sewn portion when the airbag is deployed.

  The ripstop structure is a warp yarn and / or a weft yarn constituting a plain weave structure, and two or more yarns (ripstop yarn) are arranged at the time of weaving at a specific pitch and woven into a lattice pattern or a stripe pattern. It is a woven fabric having a lattice pattern or a stripe pattern woven after a yarn having a fineness or a fineness compared to the fineness of the ground yarn (ripstop yarn) is prepared before weaving. The ripstop yarn that constitutes the pattern can be used by arranging a plurality of the same yarns as the ground yarn, but when using it as a base fabric for an airbag, use a ripstop yarn with a total fineness different from the total fineness of the ground yarn. It is preferable to use a ripstop yarn whose total fineness is about 1.2 to 1.5 times larger than the total fineness of the ground yarn. When a plurality of ground yarns are arranged to form a ripstop yarn, the difference in fineness from the ground yarn is more than doubled, and the degree of freedom of the woven fabric structure is increased, which may increase the air permeability. On the contrary, when the ripstop yarn is smaller than the total fineness of the ground yarn, the degree of freedom of the structure decreases and the air permeability decreases, but the tear strength may decrease.

  When the interval for introducing such a ripstop yarn is narrower than 1.0 cm, the tearing strength is increased as compared with a fabric woven into a plain structure using a ground yarn, but the portion where the ripstop yarn and the ground yarn are adjacent to each other increases. To increase air permeability. Moreover, when the space | interval which introduces a ripstop yarn is made wider than 10.0 cm, the effect which improves tearing strength may become low.

  In addition, it is possible to obtain a striped fabric by using such a ripstop yarn only in the warp direction of the fabric, preferably intermittently. However, such a fabric can also improve the tear strength. Can be made. Such a fabric with a specific structure does not use a dobby opening and only one device for inserting a weft thread, so the capital investment is small, and the weaving speed is the same as when weaving a plain structure. This is advantageous in terms of cost.

The air bag base fabric of the present invention has a tear strength that is 5% or more larger in both the vertical and horizontal directions than the tear strength of the fabric consisting only of the ground yarn constituting the fabric as a characteristic after boiling water shrinkage. And satisfying these two requirements that the air permeability of the fabric is 1.20 L / cm ² / min or less when measured at a test differential pressure ΔP = 19.6 kPa as an airbag. It is important from a functional standpoint. Such a characteristic is produced by shrinking the base fabric for an air bag comprising the above-mentioned specific constituents and tissue with boiling water.
That is, the manufacturing method of the airbag fabric of the present invention uses a synthetic fiber having a boiling water shrinkage of 2 to 15% in the state of a woven fabric, and forms a ripstop structure at an interval of 1.0 to 10.0 cm. The synthetic fiber fabric woven in the form of having a shrinkage treatment in a water bath within a temperature range of 60 to 140 ° C.

The air bag base fabric of the present invention is subjected to shrinkage treatment in a water bath within a temperature range of 60 to 140 ° C., so that the air permeability is 1.2 L / cm ² when measured at a test differential pressure ΔP = 19.6 kPa. In order to be used as a base fabric for an air bag of / min or less, it is possible to realize a sufficiently low air permeability. When the water bath treatment is performed within the temperature range, the synthetic fibers and the base fabric contract, and the pores of the fabric are closed by the compression due to the contraction. Thereby, the base fabric for airbags which has the low air permeability of 1.20 L / cm < ² > / min or less at the time of measurement by test differential pressure (DELTA) P = 19.6kPa can be obtained.

For such treatment in a water bath, a temperature range of 80 to 100 ° C. is particularly preferred. The reason is that this temperature range can be obtained by performing the necessary shrinkage at 80 ° C. or higher in order to realize a low air permeability of 1.00 L / cm ² / min or less. By performing the treatment at 100 to 140 ° C. or higher, low air permeability of 1.00 L / cm ² / min or less can be realized. However, when working at a temperature higher than 100 ° C., it must have a machine such as HT jigger, and it is an open soap type continuous scouring machine generally used for scouring woven fabrics. A medium suspension type continuous processing machine, a wins dyeing machine, a softener scouring machine, etc. cannot be used, which is disadvantageous in terms of cost. When the water bath treatment is performed at a temperature lower than 60 ° C., sufficient shrinkage cannot be obtained, and the air permeability becomes higher than 1.20 L / cm ² / min. Water bath treatment at a temperature higher than 140 ° C. may not be possible with an HT jigger and is not a realistic condition.

  The airbag fabric described here has the advantage that a fabric with low breathability can be obtained while maintaining the high mechanical properties unique to the ripstop structure, very easily and cost-effectively. is there.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to these. In addition, each evaluation in an Example was performed in accordance with the following method.

[Boiling water shrinkage]
It calculated | required based on JISL1013 (8.18.1) (1999).

[density]
It calculated | required based on JISL1096 (8.6.1) (1999).

[Unit weight]
The weight of the fabric of 1 m in length and 1 m in width was measured to determine the basis weight.

[Tensile strength]
Based on JIS L1096 (8.12.1A method) (1999), the breaking strength was measured when the woven fabric was pulled at a tension gripping distance of 20 cm and a tensile speed of 100 mm / min. The measurement result was converted to N / cm.

[Elongation]
It calculated | required based on JISL1096 (8.12.1A method) (1999).

[Tearing strength]
Based on JIS L1096 (8.15.2A-2 method) (1999), the tear strength when pulled at a tensile speed of 200 mm / min was determined.

[Air permeability]
The fluid (air) was adjusted to a pressure of 19.6 kPa to flow, and the air flow rate (L) that passed through the unit area (cm ² ) and unit time (min) was defined as the air permeability (L / cm ² / min).

Example 1
Nylon 6.6 fibers with a fineness of 350 dtex, 72 filaments and boiling water shrinkage of 8.5%, ground yarn, nylon 6.6 fibers with a fineness of 470 dtex, 72 filaments, boiling water shrinkage of 8.5%, and ripstop yarn In the water jet loom, a warp yarn and weft yarn weaving density of 57 yarns / 2.54 cm and a 1.5 cm grid pattern ripstop texture were obtained.

  Next, scouring and relaxing with 90 ° C hot water containing a surfactant in an open soap type continuous scouring machine liquid flow type dyeing machine, drying at 130 ° C, heat setting at 180 ° C, warp and horizontal A woven fabric having a yarn density of 59 / 2.54 cm was obtained.

  Table 1 summarizes raw yarn characteristics, raw yarn operability, and obtained fabric characteristics and quality.

As is clear from the results in Table 1, the boiling water shrinkage of the original yarn is 8.5%, and the tear strength is woven into a plain structure using ground yarn by making the woven fabric a ripstop structure with an interval of 1.5 cm. 5% or more in both the vertical and horizontal directions with respect to the tearing strength of the base fabric, the air permeability is 0.82 L / cm ² / min, and the low air permeability is maintained while maintaining the high mechanical characteristics peculiar to the ripstop structure. Had.

  When the obtained airbag base fabric was deployed, sufficient internal pressure was maintained to protect the passengers in the event of an automobile accident, and no problems such as breakage of the bag occurred.

(Example 2)
The raw machine described in Example 1 is scoured and relaxed with hot water at 120 ° C. containing a surfactant with an HT jigger, dried at 130 ° C., heat-set at 180 ° C., and warp yarn and weft yarn density. A 59 / 2.54 cm woven fabric was obtained.

  The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

As apparent from Table 1, the boiling water shrinkage of the raw yarn was 8.5%, and the tear strength was woven into a plain structure using ground yarn by making the woven fabric a ripstop structure with an interval of 1.5 cm. 5% or more larger in both the vertical and horizontal directions than the tear strength of the fabric, and the air permeability is 0.79 L / cm ² / min, maintaining low mechanical permeability while maintaining the high mechanical properties unique to ripstop structures. Was.

  When the obtained airbag base fabric was deployed, sufficient internal pressure was maintained to protect the passengers in the event of an automobile accident, and no problems such as breakage of the bag occurred.

(Example 3)
Nylon 6.6 fibers with a fineness of 350 dtex, 72 filaments and a boiling water shrinkage of 8.5% are ground yarn, and two nylon 6.6 fibers with a fineness of 235 dtex, 36 filaments and a boiling water shrinkage of 8.5% are arranged side by side Used as a warp ripstop thread, the ripstop part in the horizontal direction in the water jet loom is put into the same two necks, and the weave density of the warp thread and the weft thread is 57 / 2.54cm with a 1.5cm lattice I got a ripstop texture of life.

  Next, the same treatment as in the example was performed to obtain a woven fabric having a warp yarn and weft yarn density of 59 yarns / 2.54 cm.

  The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

As apparent from Table 1, the boiling water shrinkage of the raw yarn was 8.5%, and the tear strength was woven into a plain structure using ground yarn by making the woven fabric a ripstop structure with an interval of 1.5 cm. 5% or more larger in both the vertical and horizontal directions than the tear strength of the fabric, and the air permeability is 0.73 L / cm ² / min, maintaining low mechanical permeability while maintaining the high mechanical properties unique to the ripstop structure. Was.

  When the obtained airbag base fabric was deployed, sufficient internal pressure was maintained to protect the passengers in the event of an automobile accident, and no problems such as breakage of the bag occurred.

Example 4
Nylon 6.6 fibers with a fineness of 350 dtex, 72 filaments and boiling water shrinkage of 8.5%, ground yarn, nylon 6.6 fibers with a fineness of 470 dtex, 72 filaments, boiling water shrinkage of 8.5%, and ripstop yarn In the water jet loom, the weft density of the warp and weft yarns was 57 / 2.54 cm, and the ripstop yarn was used only in the warp direction to obtain a ripstop texture with a 1.5 cm stripe pattern.

  Then, the same treatment as in Example 2 was performed to obtain a woven fabric having a warp yarn and weft yarn density of 59 yarns / 2.54 cm.

  The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

As apparent from Table 1, the boiling water shrinkage of the raw yarn was 8.5%, and the tear strength was woven into a plain structure using ground yarn by making the woven fabric a ripstop structure with an interval of 1.5 cm. 5% or more larger in both the vertical and horizontal directions than the tear strength of the fabric, and the air permeability is 0.80 L / cm ² / min. It has a low air permeability while maintaining the high mechanical properties unique to the ripstop structure. Was.

  When the obtained airbag base fabric was deployed, sufficient internal pressure was maintained to protect the passengers in the event of an automobile accident, and no problems such as breakage of the bag occurred.

(Example 5)
Nylon 6.6 fibers with a fineness of 350 dtex, 72 filaments and a boiling water shrinkage of 8.5% are used as the ground yarn and two ripstop yarns. The weft density of the warp and weft yarns is 57 in the water jet loom. /2.54cm, using ripstop yarn only in the warp direction, in the water jet loom, driving the ripstop part in the horizontal direction into the same mouth, and the weaving density of warp and weft yarns is 57 / A living machine having a ripstop structure of a lattice pattern of 2.54 cm and 1.5 cm was obtained.

  Next, the same treatment as in the example was performed to obtain a woven fabric having a warp yarn and weft yarn density of 59 yarns / 2.54 cm.

  The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

As apparent from Table 1, the boiling water shrinkage of the raw yarn was 8.5%, and the tear strength was woven into a plain structure using ground yarn by making the woven fabric a ripstop structure with an interval of 1.5 cm. 5% or more larger in both the vertical and horizontal directions than the tear strength of the fabric, and the air permeability is 0.94 L / cm ² / min. It has a low air permeability while maintaining the high mechanical properties peculiar to the ripstop structure. Was.

  When the obtained airbag base fabric was deployed, sufficient internal pressure was maintained to protect the passengers in the event of an automobile accident, and no problems such as breakage of the bag occurred.

(Comparative Example 1)
Nylon 6.6 fiber with a fineness of 350 dtex, 72 filaments and a boiling water shrinkage of 1.5%, ground yarn, Nylon 6.6 fiber with a fineness of 470 dtex, 72 filaments and a boiling water shrinkage of 1.5%, ripstop yarn Weaving and treatment were performed in the same manner as in Example 1 to obtain an airbag base fabric having a warp yarn and weft yarn density of 59 pieces / 2.54 cm.

  The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

As is clear from Table 1, the air permeability of the obtained woven fabric is 1.20 L / cm ² / min or higher, thread breakage occurs frequently in terms of operability during production of the raw yarn, and the quality of the fabric due to fluff is poor, When used as an air bag base fabric, there is no problem in mechanical properties, but it is highly breathable and poor in quality, so it is necessary to protect passengers when used as an air bag base fabric. It became a material with the fear that internal pressure cannot be maintained.

(Comparative Example 2)
Nylon 6.6 fiber with a fineness of 350 dtex, 72 filaments and 16.5% boiling water shrinkage, ground yarn, Nylon 6.6 fiber with a fineness of 470 dtex, 72 filaments and boiling water shrinkage of 16.5%, ripstop yarn Weaving and treatment were performed in the same manner as in Example 1 to obtain an airbag base fabric having a warp yarn and weft yarn density of 59 pieces / 2.54 cm.

  The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

As is apparent from Table 1, the air permeability of the obtained fabric is 1.20 L / cm ² / min or more, and the floating machine generates a floating width. There is no problem in terms of mechanical properties to use it as an air bag base fabric, but it is highly breathable, and the shape is not stable after bag sewing, so the quality is poor. When used, it became a material with a concern that the internal pressure required to protect passengers cannot be maintained.

(Comparative Example 3)
The raw machine of Example 1 was subjected to scouring / relaxation treatment with hot water at 40 ° C. containing a surfactant in an open soap type continuous scouring machine liquid flow type dyeing machine, dried at 130 ° C., and heat set at 180 ° C. A warp yarn and a weft yarn density of 59 yarns / 2.54 cm were obtained.

  The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

As is apparent from Table 1, the air permeability of the obtained woven fabric is 1.20 L / cm ² / min or more, and there is no problem in mechanical properties when used as a base fabric for an air bag. Therefore, when used as a base fabric for an air bag, the material has a concern that the internal pressure necessary to protect the occupant cannot be maintained.

(Comparative Example 4)
A raw material having a 15.0 cm lattice pattern ripstop structure was obtained using the same raw yarn as in Example 1. Next, the same treatment as in Example 1 was performed to obtain a woven fabric having a warp yarn and weft yarn density of 59 yarns / 2.54 cm.

  The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

  As is apparent from Table 1, since the obtained woven fabric had a ripstop structure with an interval of 10.0 cm, the tear strength was vertical and horizontal with respect to the tear strength of the base fabric woven into a plain structure using ground yarn. There is no problem with the air permeability of the surface of the base fabric to use as an air bag base fabric, both of which do not improve by 5% or more, but because of low tear strength, an automobile accident occurs when used as an air bag base fabric. Occasionally, the bag was torn or the air permeability from the sewn part was high, and the material could not hold the internal pressure required to protect the occupant.

(Comparative Example 5)
Using a nylon 6.6 fiber having a fineness of 350 dtex, a filament count of 72, and a boiling water shrinkage of 8.5%, a plain tissue with a density similar to that of Example 1 was obtained in a water jet loom. Next, the same treatment as in Example 1 was performed to obtain a woven fabric having a warp yarn and weft yarn density of 59 yarns / 2.54 cm.

  The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

  As is apparent from Table 1, since the obtained woven fabric does not have a ripstop structure, there is no problem with the air permeability of the surface of the base fabric for use as a base fabric for an air bag. When used as a base fabric for a bag, the bag was torn in the event of an automobile accident, or the air permeability from the sewing part was high, and it was a material that could not hold the internal pressure required to protect the occupant.

  INDUSTRIAL APPLICABILITY The present invention has a low air permeability while maintaining high mechanical characteristics unique to a ripstop structure, and is useful because it can promote and promote an occupant protection system using an airbag.

Claims (9)

A synthetic fiber woven fabric having a ripstop structure at an interval of 1.0 to 10.0 cm, which is larger by 5% or more in both the vertical and horizontal directions than the tearing strength of the woven fabric consisting only of the ground yarn constituting the woven fabric. An air bag base fabric having tear strength and having an air permeability of 1.20 L / cm ² / min or less when measured at a test differential pressure ΔP = 19.6 kPa. The air bag base fabric according to claim 1, wherein the air permeability of the fabric is 1.00 L / cm ² / min or less when measured at a test differential pressure ΔP = 19.6 kPa. The base fabric for an air bag according to claim 1 or 2, wherein the total fineness of the woven yarn constituting the woven fabric is in the range of 200 to 600 dtex. The base fabric for an air bag according to any one of claims 1 to 3, wherein the total fineness of the ground yarn constituting the woven fabric is not the same as the total fineness of the ripstop yarn constituting the ripstop structure. The base fabric for an air bag according to any one of claims 1 to 4, wherein the ripstop yarn is used as the warp yarn of the woven fabric. 6. The airbag fabric according to claim 5, wherein the ripstop yarn is used intermittently as a warp yarn of the fabric. The base fabric for an air bag according to any one of claims 1 to 6, wherein the woven fabric is non-coated. A synthetic fiber fabric woven in a form having a ripstop structure at intervals of 1.0 to 10.0 cm using a synthetic fiber having a boiling water shrinkage of 2 to 15% in the state of the woven fabric is 60 to 140 ° C. The manufacturing method of the base fabric for airbags which performs shrinkage | contraction processing in a water bath within the temperature range of this. The method for producing a base fabric for an air bag according to claim 8, wherein the shrinkage treatment is performed in a water bath within a temperature range of 80 to 100 ° C.