JP2017036530A - Base fabric for air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive base cloth for an air bag in which airtightness after endurance maintains performance equal to that of the initial product.SOLUTION: Provided is a base fabric for an air bag, produced using polyester synthetic fiber, in which, by subjecting an unrefined base cloth for an air bag stuck with a paste to calender working, the paste stuck to the warp of the base cloth for an air bag is spread to a weft and the cross part between the warp and the weft to cover almost the whole region of the surface of the base cloth for an air bag. Regarding the base cloth for an air bag, in an airtightness test, the internal pressure holding rate after 6 s of the initial product when the maximum internal pressure is defined as 60 kPa is 80% or more, and the change rate of the durable treated product of the base cloth for an air bag to the initial product under the internal pressure after 6 s is 20% or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an air bag base fabric used for an air bag that is rapidly inflated to reduce the impact of an occupant in order to protect the occupant when the vehicle collides with another vehicle or an obstacle, particularly in the event of a side collision of the vehicle. About.

  Most cars currently in production have driver seats that expand rapidly between the occupant and the steering or front panel to ensure occupant safety when the front of the car collides with another vehicle or obstacle. Airbags for passenger and passenger seats are installed.

  In recent years, in order to protect not only this frontal collision, but also the passenger's head when the side of the vehicle collides with another vehicle or obstacle, it is folded into the ceiling or pillar on the side window of the vehicle. A curtain airbag that is housed and inflates so as to cover the side window at the time of a collision is installed in earnest. Curtain airbags are required to have higher airtightness than airbags mounted on the front surface.

  Further, as is well known, an airbag is required to have little performance change over a long period of time, and it is important to maintain the same performance as that of the initial product with little change over time in the impact reduction performance of the occupant.

  On the other hand, in order to cope with the cost reduction in recent automobile manufacturing, it is required to provide an inexpensive base fabric including simplified processes in the airbag.

  In patent document 1, the manufacturing method of the low air permeable fabric which performs a calendar process in the state in which the paste remained was disclosed. However, Patent Document 1 does not describe the performance after the durability treatment. Durability is an indispensable item as a characteristic required for airbags. Even if the characteristics of the initial product are good, safety cannot be ensured unless the durability can be confirmed.

  Patent Document 2 discloses a technique in which a polyester resin and a low-volatile softening agent are treated with an aqueous treatment agent or the like in which water is dispersed. However, Patent Document 2 aims to prevent the occurrence of yarn slip at the time of cutting by forming a coating layer with a novel coating agent on a woven fabric. And although the breathability of the resin-treated fabric of the example of Patent Document 2 is lower than that of the non-coated fabric (Comparative Examples 6 and 7 of Patent Document 2), it is excellent in durability intended for the present invention. Airtightness is not obtained.

Patent 3085811 JP-A-11-222776

  In view of the above problems, the present invention provides an airbag that is inflated rapidly to protect the occupant and reduce the impact of the occupant when the automobile collides with another automobile or an obstacle, particularly in the case of a side collision of the automobile. With respect to the airbag base fabric to be used, the present invention provides an inexpensive base fabric that includes an extremely low deterioration in hermeticity due to aging and further simplification of the process.

  The present invention relates to a base fabric for an air bag. As a result of keen ingenuity to provide an inexpensive base fabric including a simplified process, there is little decrease in airtightness due to aging. It has been found that an air bag base fabric having a durable and airtight property can be provided at low cost even if the process is omitted.

  The present invention is an air bag base fabric, wherein the air bag base fabric is made of a polyester-based synthetic fiber, and the unscoured air bag base fabric with the paste attached thereto is used. By calendering, the glue adhering to the warp of the airbag base fabric is spread to the weft and the intersection of the warp and the weft, covering substantially the entire surface of the airbag base fabric. In the airtightness test, the air bag base fabric has an internal pressure retention rate of 80% or more after 6 seconds when the maximum internal pressure is 60 kPa, and the air bag base fabric has a durability treatment. The rate of change of the internal pressure after 6 seconds with respect to the initial product is within 20%. The internal pressure retention rate and the rate of change relative to the initial product in the present invention are: internal pressure retention rate = P6 / 60 × 100% when the internal pressure after 6 seconds of the initial product is P6 and the internal pressure after 6 seconds of the durable product is AP6. The rate of change with respect to the initial product = (1−AP6 / P6) × 100%. Here, the durability-treated product is (a) aged under heat-resistant conditions (100 ° C. × 500 hours) and (b) aged under heat-and-moisture resistant conditions (60 ° C. × 95% RH × 500 hours). It means that the endurance-treated product of any condition, including both, satisfies the above rate of change.

  Moreover, according to one Embodiment of this invention, the said adhesive agent contains a polyester resin and a smoothing agent.

  Moreover, according to one Embodiment of this invention, the said smoothing agent is a wax.

  Moreover, according to one Embodiment of this invention, the mixing ratio of the said paste agent is 50 to 90 weight% of polyester resins, and 5 to 30 weight% of waxes.

  Moreover, according to one Embodiment of this invention, the adhesion rate to the said warp of the said adhesive agent is 5 to 20 weight%.

  Further, according to another aspect of the present invention, the present invention includes a step of weaving a base fabric for an airbag using a polyester-based synthetic fiber in which a paste is attached to a warp, and a step in which the paste remains unattached. And a step of calendering the air bag base fabric of scouring, wherein the air bag base fabric has a maximum internal pressure of 60 kPa in an airtightness test. The internal pressure retention rate after 6 seconds of the initial product is 80% or more, and the change rate of the internal pressure after 6 seconds of the durable product of the airbag base fabric with respect to the initial product is within 20%.

  According to the present invention, when an automobile collides with another automobile or an obstacle, especially in the case of a side collision of the automobile, the airbag is used for an airbag that is rapidly inflated to protect the occupant to alleviate the impact of the occupant. With respect to the base fabric, it is possible to provide an inexpensive base fabric including a reduction in hermeticity due to aging and further including a simplified process.

It is the surface enlarged observation photograph of the Example of this invention, and shows a resin film. It is the surface enlarged observation photograph of the conventional base fabric (scouring cloth, without calendar process). The base fabric external appearance shape of the Example of this invention is shown.

  The present invention uses a polyester-based synthetic fiber and is a base fabric for an air bag obtained by calendering an unscoured base fabric with a paste attached, and the maximum internal pressure is 60 kPa in an airtightness test. An air bag base fabric characterized in that the internal pressure retention rate after 6 seconds of the initial product is 80% or more, and the change rate of the internal pressure after 6 seconds of the endurance-treated product is within 20%. is there.

  It is important to use a polyester-based synthetic fiber for the airbag fabric of the present invention. Polyester synthetic fibers are not only inexpensive among industrially produced fiber materials used for airbag fabrics, but also have excellent adaptability to manufacturing processes such as weaving, cutting and sewing. The sustainability of the crushing effect by the calendar processing used is high.

  As the polyester-based synthetic fiber used in the present invention, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate or the like may be used alone, mixed or copolymerized. Moreover, if it does not affect the crushing effect of the calendering process and does not affect the base fabric properties such as adhesion to the paste, airtightness, flame retardancy, etc., in some cases, a part of the polyester-based synthetic fiber, for example, Other fiber materials within the range of 1/2 or less in weight ratio, that is, various polyamide fibers, polyolefin fibers, polyacetal fibers, polyvinyl fibers (including fluorine and chlorine), etc. are used alone or in combination. May be.

  In addition, the airbag fabric of the present invention is characterized in that a paste that is generally removed in a scouring process is utilized as a coating material. Generally, in the weaving of airbag fabrics, sizing is applied to the warp yarn to facilitate weaving, the paste is removed by washing with hot water in the scouring process, and then the coating material is coated. It is applied to the surface of the base fabric.

  In the present invention, it is an object to provide airtightness of the entire base fabric with the paste usually removed in the scouring process attached. In the present invention, the material used for the glue applied to the warp has, of course, the same weaving improvement as the glue used in the normal weaving process. High airtightness is achieved by spreading over the entire surface of the base fabric surface, including the intersection of the warp and weft yarns from the warp surface, and the weft surface, etc., and maintaining the airtightness for a long time. It is required to have excellent adhesion and flame retardancy with the airbag fabric.

  The base fabric of the present invention has an internal pressure retention rate of 80% or more after 6 seconds of the initial product when the maximum internal pressure is 60 kPa in the airtightness test, and is compared with the initial product of the internal pressure after 6 seconds of the durable product. It is essential that the rate of change is within 20%. If the internal pressure retention rate after 6 seconds of the initial product is less than 80%, the internal pressure of the airbag cannot be maintained for a long time, and the collision energy of the occupant may not be absorbed. In addition, when the rate of change of the internal pressure after 6 seconds of the durable product exceeds 20%, the internal pressure of the airbag tends to be insufficient when the airbag is deployed over a long period after manufacture. In some cases, the collision energy of the occupant cannot be absorbed.

  The paste used in the present invention preferably has a high crushing effect by calendering and is preferably thermoplastic and excellent in film formability and covering properties, but it is necessary to maintain high airtightness over a long period of time. . That is, it is required to maintain not only the airtightness of the initial product but also its characteristics after durability treatment (dry heat, wet heat). Therefore, the paste of the present invention is preferably a material that is excellent in diffusibility by calendering and has little change in properties even after endurance treatment. The glue used in the present invention is not particularly limited as long as it satisfies the above-mentioned characteristics, but may be appropriately selected from the following various materials.

  For example, polyurethane resin (including silicone modification, acrylic modification, fluorine modification), halogen-containing vinyl resin, polyester resin, polyamide resin, polyvinyl alcohol resin, ethylene vinyl acetate resin, polyolefin resin, acrylic resin, etc. Should be used. Further, it may be used as a modified product or copolymer of these resins, or a hydrophilic substituent such as a carboxyl group, a hydroxyl group, a sulfonic acid group, sodium or ammonium, or a mixture of different resins. Also good.

  Among these, the polyester resin is preferable because it is excellent in adhesion to the polyester-based synthetic fiber used in the base fabric of the present invention and is excellent in diffusibility and covering properties by calendering. Furthermore, in order to express high airtightness, it is necessary to increase the adhesion amount of the material to the warp, and it is preferable to use various smoothing agents together in order to suppress a decrease in weaving property due to an increase in adhesiveness. For example, there are waxes, alkyd resins, polyalkylene glycol resins, polyolefin resins, etc. Waxes, in particular, not only improve weaving properties, but also have a remarkable effect in improving airtight fastness, in particular moist heat aging resistance. Is preferable. Of the smoothing agents, it is not preferable to use a silicone resin, a fluororesin, or the like that has low film-forming properties and poor performance for improving airtightness.

  As the paste used in the present invention, among these resins and smoothing agents, by using a mixed material containing a polyester resin and a wax, it is possible to express long-term robust airtightness as an object of the present invention, preferable. In addition to the two components, it is also preferable to use, as the third component, a material that can increase long-term robust airtightness.

  The mixing ratio of the paste used in the present invention is preferably 50 to 90% by weight for the polyester resin and 5 to 30% by weight for the wax. If the polyester resin is less than 50%, the flame retardancy may be impaired, and if it exceeds 90%, the durability is significantly reduced. Furthermore, when the wax is less than 5%, the heat and heat aging resistance is insufficient, and when it exceeds 30%, the flame retardancy may be impaired.

  The polyester resin used in the present invention may be any aromatic, aliphatic, or alicyclic polyester compound, but is preferably an aromatic polyester resin made of terephthalic acid in terms of heat resistance and ease of handling. For example, any of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like may be used. In addition, an aromatic polyester such as polycaprolactone, polyalkylene succinate, polyhydroxyalkylate, polylactic acid, etc. may be copolymerized and mixed, and in some cases, an alicyclic polyester may be used. You may use together. In the present invention, a polyethylene terephthalate resin is preferable from the viewpoints of airtightness, flame retardancy, and weaving.

  The main component of the paste of the present invention is a polyester resin, and the effect of calendering reflects the characteristics of the polyester resin.

  As for Tg (glass transition point) of the polyester resin used by this invention, -20 degreeC-50 degreeC are preferable. When the temperature is lower than −20 ° C., the tackiness is high, and there is a possibility of causing trouble during weaving. When the temperature exceeds 50 ° C., the flexibility is poor, and the base fabric becomes hard, which may hinder storage.

  The softening point of the polyester resin used in the present invention is preferably 100 ° C. or higher. When the temperature is lower than 100 ° C., it becomes easy to adhere, and there is a possibility that trouble may occur when the folded airbag is deployed. The molecular weight is more preferably 1,000 to 40,000, and even more preferably 10,000 to 20,000. When the molecular weight is less than 1,000, the physical properties of the film are insufficient, and when it exceeds 40,000, the film tends to be brittle.

  The types of waxes used in the present invention are natural waxes such as petroleum waxes (paraffin wax, microcrystalline wax, petrolatum), mineral waxes (montan wax, ozokerite, ceresin), animal waxes (beeswax, lanolin, whale wax, (Wool wax), vegetable oils (candelilla wax, carnauba wax, rice wax, wood wax, sugarcane wax, palm wax, castor oil), synthetic hydrocarbons (polyethylene wax, Fischer-Tropsch wax), fatty acid esters Wax (coconut oil, beef tallow fatty acid methyl ester), fatty acid amide (stearic acid amide), modified wax (modified montan wax, modified paraffin wax, modified microcrystalline wax), hydrogenated wax (cured castor) ) May be any such, but durable, paraffin wax is preferable from the viewpoint of weaving property.

  It is preferable to use a polyvinyl alcohol resin as the third component of the paste of the present invention. Polyvinyl alcohol resin is extremely excellent in heat resistance and can exhibit stable airtightness over a long period of time. From the viewpoint of heat aging resistance and weaving properties, the polymerization degree is preferably 200 to 2000, and the saponification degree is preferably 80% or more. When the degree of polymerization is less than 200, the coating strength is lowered, and when it exceeds 2000, the solution viscosity becomes high, which may impair the compatibility with other resins. On the other hand, when the degree of saponification is less than 80%, the resin strength tends to be low, and the moisture resistance of the coating tends to decrease. What is necessary is just to select suitably from the range of 10 to 40% as a usage-amount of polyvinyl alcohol resin, for example. If it is less than 10%, the heat aging resistance is insufficient, and if it exceeds 40%, the viscosity of the mixed resin is too high, and the adhesion rate to the warp may be difficult to control.

  Further, the polyvinyl alcohol resin may be copolymerized and mixed with other polyvinyl resins such as polyvinyl chloride resin, polyvinyl acetate resin, or poly (meth) acrylic resin. In particular, ethylene vinyl acetate resin, poly (meth) acrylic resin, and the like can exhibit excellent coverage.

  The solution of the resin mixture used in the present invention may be any of a solvent liquid, an aqueous solution, an aqueous dispersion, etc., but an aqueous solution is preferable from the viewpoint of working environment and solution stability. The viscosity of the mixed solution is preferably 50 to 1,000 mPa · s, and more preferably 100 to 500 mPa · s. When the viscosity is less than 50 mPa · s, it is difficult to increase the amount of adhesion to the warp and it is difficult to obtain good airtightness. On the other hand, when it exceeds 1,000 mPa · s, the amount of adhesion increases and the weaving property may be lowered.

  Moreover, in this invention, 5-20 weight% is preferable and the adhesion rate to the warp of the said resin mixture is preferable, and 7-15 weight% is still more preferable. When the adhesion rate is less than 5%, airtightness and flame retardancy are insufficient, and when it exceeds 20%, it becomes hard and the weight of the base fabric increases.

  In the present invention, it is important to calendar the airbag fabric. By calendering, the base material for airbags having high airtightness can be obtained with a small amount of resin by spreading and spreading the adhesive adhering to the warp to the weft and the intersection of the warp and the weft. it can.

  The calendering load is preferably 500 to 1000 kN / cm, more preferably 600 to 800 kN / cm. If it is less than 500 kN / cm, it will be difficult to maintain the airtightness due to insufficient force to push the glue adhering to the warp to the weft and the intersection of the warp and weft. If it exceeds 1000 kN / cm, the airbag The physical properties of the base fabric may be impaired.

  The calendering temperature is preferably 130 to 200 ° C, more preferably 150 to 180 ° C. When the temperature is less than 130 ° C., the adhesive attached to the warp is difficult to melt, and it is difficult to penetrate the weft and the weft intersection, making it difficult to maintain airtightness. Moreover, when it exceeds 200 degreeC, there exists a possibility that the physical characteristic of a base fabric may be impaired remarkably.

  The calendering speed is preferably 1 to 20 m / min, and more preferably 3 to 15 m / min. When the speed is less than 1 m / min, pressure and temperature are excessively applied to the airbag base fabric, which may impair the characteristics of the paste and the airbag base fabric. In addition, when it exceeds 15 m / min, the pressure and temperature applied to the airbag fabric are insufficient, and the force that pushes the glue adhering to the warp to the weft and the intersection of the warp and the weft is weak and airtightness is reduced. It becomes difficult to keep.

  The base fabric surface to be calendered may be either single-sided or double-sided as necessary. Further, the material of the calendar roll may be any of metal, rubber, etc., all in the case of double-sided heating, and single-sided metal in the case of single-sided heating. Moreover, when performing calendar processing on both surfaces of a base fabric, you may perform twice etc. as needed.

  Further, the woven fabric used in the present invention preferably has a cover factor of 1800 or more, more preferably 2000 or more, which is an index indicating the density of the woven structure.

The cover factor (CF) is generally determined by the product of the weave density and the fineness of each warp and weft of the fabric, and is represented by the following formula.
CF = Nw × √Dw + Nf × √Df
Here, Nw and Nf are the weave densities of the warp and the weft, and Dw and Df are the fineness of the warp and the weft.

  The weave density of the airbag base fabric may be appropriately selected depending on the fineness of the raw yarn used. For example, for 555 dtex, the warp and weft may be 90 to 120 / 2.54 cm. When the fineness of the raw yarn changes, the weaving density may be converted to the raw yarn fineness according to the performance of the loom.

  The weaving density may be equal to the number of warps and wefts, or may have a density difference as long as the physical properties of the airbag fabric are not affected.

  The fineness of the warp and weft of the base fabric used in the present invention may be selected from the thickness of the yarn usually used for airbag fabrics, that is, the range of 150 to 1,000 dtex, preferably 235 to 700 dtex. It may be in the range. If the fineness is thinner than 150 dtex, the strength required for the airbag fabric tends to be difficult to obtain, and if it exceeds 1,000 dtex, the basis weight tends to be too large.

  The yarn strength may be 7 cN / dtex or more, preferably 8 cN / dtex or more. The single yarn thickness of the yarn may be in the range of 0.5 to 6 dtex. Furthermore, the cross-sectional shape of the single yarn may be appropriately selected within a range that does not hinder the production and physical properties of the fabric, such as a circular shape, an oval shape, a flat shape, a polygonal shape, a hollow shape, and other different types. Moreover, you may use what integrated the some thread | yarn from which a fineness, a cross-sectional shape, etc. differ by the combined yarn and twist.

  The warp and weft of the airbag fabric of the present invention may be different in total fineness, single yarn fineness, strength, cross-sectional shape, and the like.

The fabric used in the present invention preferably has a basis weight of 260 g / m ² or less and a tensile strength of 650 N / cm or more. If the basis weight and the tensile strength are within this range, it can be said that it is light and excellent in physical properties. If the weight per unit area exceeds 260 g / m ² , the weight of the base fabric increases, making it difficult to achieve the desired weight reduction. On the other hand, if the tensile strength is less than 650 N / cm, it may not be possible to satisfy the physical properties required for the airbag fabric.

  The type of loom for weaving the airbag fabric of the present invention is not particularly limited, and usually a loom used for weaving industrial fabrics may be selected as appropriate. For example, water jet looms, rapier looms, air jet looms, shuttle looms, projectile looms, etc. are mentioned. An air jet loom capable of weaving at high speed and in a short time simplifies the process that is the object of the present invention. It is preferable from the viewpoint of conversion.

  An airbag using the airbag fabric of the present invention can be created by sewing, bonding, welding, weaving, knitting, etc., and the shape is appropriately determined according to the mounting site, required performance, etc. A double woven base fabric having a bag-woven structure by weaving may be used for the curtain airbag.

  Next, the present invention will be specifically described by way of examples. The characteristics of the air bag base fabric were evaluated as follows.

(1) Airtightness test Using a metal cylinder (outer diameter 200mm, inner diameter 180mm, length 250mm) provided with a flange with a clamp-fixed lid at one end, a hole with a diameter of 100mm is provided in the center of the lid It was. A packing material was affixed on both surfaces of the flange portion, and the sample was set so that the sample was sandwiched between the flange portions. The cylinder was filled with compressed air, and the maximum pressure in the cylinder and the attenuation of the pressure were measured with a sensor.

(2) Durability test (a) Aging was performed under heat resistant conditions (100 ° C. × 500 hours) and (b) wet heat resistant conditions (60 ° C. × 95% RH × 500 hours), and airtightness was evaluated.

[Example 1]
Use polyester yarn (fineness: 555 dtex, 144 single yarns) manufactured by Hailide Co., and 60% by weight of polyester resin (plus coat Z-880 manufactured by Kyoyo Chemical Industry Co., Ltd., Tg (glass transition point) 20 ° C., softening point about 90 ° C.). , 20% by weight of polyvinyl alcohol resin (PVA-205 manufactured by Kuraray Co., Ltd., polymerization degree 500, saponification degree 86.5-89) and 20% by weight of wax (Cytex K-2500 manufactured by Kyoyo Chemical Industry Co., Ltd.) Sizing the paste (solid content concentration 24%, solution viscosity 200mPa · s) so that the adhesion rate to the warp is 14% of the yarn weight, and air equipped with a jacquard machine (made by Stäubli) A base fabric for a bag-woven airbag having the shape shown in FIG. 3 was woven using a jet loom (manufactured by Dornier).

  The air bag base fabric after weaving was heat-set at 150 ° C. for 1 minute without scouring and with the paste applied to the warp.

  Next, calendering (loading 700 N / cm, temperature 170 ° C., speed 3 m / min) was performed on the airbag fabric, and the bag fabric airbag 2 was obtained from the obtained bag fabric airbag fabric (1 in FIG. 3). Was cut along the shape of the cutting line 3, a test piece was taken from one of the base fabrics, and the airtightness was measured. The finished density of the base fabric was 57 warps / inch and 49 wefts / inch. As shown in Table 1, there is no great difference between the initial product and the airtightness after durability, and extremely excellent durability is exhibited.

[Example 2]
In Example 1, as a paste, 70% by weight of a polyester resin, 10% by weight of an ethylene vinyl acetate resin (Evaflex manufactured by Mitsui DuPont Polychemical Co., Ltd., Tg (glass transition point) -25 ° C.) and 20% by weight of wax An airbag base fabric was prepared according to Example 1 except that it was prepared using a three-component mixture. As shown in Table 1, there is no great difference between the initial product and the airtightness after durability, and extremely excellent durability is exhibited.

[Comparative Example 1]
In Example 1, an airbag base fabric was prepared according to Example 1 except that only polyester resin was used as the paste. As shown in Table 1, there was a large difference between the initial product and the airtightness after durability, and the durability which is the object of the present invention was not obtained.

[Comparative Example 2]
In Example 1, an airbag base fabric was prepared according to Example 1 except that calendaring was not performed. As shown in Table 1, the effect of crushing the base fabric by calendering was not obtained, the initial maximum internal pressure was less than 60 kPa, the airtightness was insufficient, and the performance was not obtained.

[Comparative Example 3]
In Comparative Example 1, an airbag base fabric was prepared according to Comparative Example 1 except that the warp sizing agent was removed by scouring. As shown in Table 1, when almost no adhesive was adhered, the airtightness was greatly insufficient and the performance could not be obtained.

[Comparative Example 4]
In Comparative Example 3, an airbag base fabric was prepared according to Comparative Example 3 except that the coating process was performed without performing the calendar process. In the coating process, 40 g / m ² of an addition type thermosetting silicone resin was applied to both surfaces of the airbag fabric, and then heat-treated at 180 ° C. for 1 minute to obtain a coated fabric. As shown in Table 1, although the performance was satisfied, an inexpensive airbag fabric that was the object of the present invention was not obtained.

Remarks PET: Polyester resin PVA: Polyvinyl alcohol resin EVA: Ethylene vinyl acetate resin

1 Airbag Base Fabric 2 Bag Woven Airbag 3 Cut Line

Claims (10)

  A base fabric for an air bag, wherein the base fabric for an air bag is made of a polyester-based synthetic fiber and calenders the unscoured base fabric for an air bag with a paste attached. The glue adhering to the warp of the airbag base fabric is spread to the weft and the intersection of the warp and the weft, covering substantially the entire surface of the airbag base fabric, and the airbag In the airtightness test, the base fabric has an internal pressure retention of 80% or more after 6 seconds of the initial product when the maximum internal pressure is 60 kPa, and 6 seconds of the durable treated product of the airbag fabric. A base fabric for an air bag, characterized in that the rate of change of the internal pressure after the initial product is within 20%.   The airbag base fabric according to claim 1, wherein the paste contains a polyester resin and a smoothing agent.   The airbag fabric according to claim 2, wherein the smoothing agent is a wax.   The base fabric for an air bag according to any one of claims 1 to 3, wherein the mixture ratio of the paste is 50 to 90% by weight for the polyester resin and 5 to 30% by weight for the wax. .   The base fabric for an air bag according to any one of claims 1 to 4, wherein an adhesion rate of the paste to the warp is 5 to 20% by weight.   A step of weaving a base fabric for an airbag using a polyester-based synthetic fiber with a paste attached to a warp, and a step of calendering the unscoured airbag base fabric with the paste attached A method for producing an airbag base fabric, wherein the airbag base fabric has an internal pressure retention of 80% or more after 6 seconds of the initial product when the maximum internal pressure is 60 kPa in an airtightness test. And the change rate of the internal pressure after 6 seconds of the durable treated product of the airbag base fabric with respect to the initial product is within 20%.   The method for producing a base fabric for an air bag according to claim 6, wherein the paste contains a polyester resin and a smoothing agent.   The method for producing a base fabric for an air bag according to claim 7, wherein the smoothing agent is a wax.   9. The airbag base fabric according to claim 6, wherein the mixture ratio of the paste is 50 to 90% by weight of the polyester resin and 5 to 30% by weight of the wax. Manufacturing method.   The method for producing a base fabric for an air bag according to any one of claims 6 to 9, wherein an adhesion rate of the paste to the warp is 5 to 20% by weight.