JPWO2018062132A1 - Non-coated woven fabric for air bag and air bag using the same - Google Patents

Abstract

A non-coated fabric for an air bag, which leaks less air than a non-coated fabric for an air bag developed by the prior art, and can be used even at a site which can not be used conventionally unless it is a coated fabric for an air bag Provide an air bag used. SOLUTION: The cross section shape is a substantially triangular shape, includes single yarn fibers having a heteromorphic degree of 1.3 to 2.2, a cover factor (CF) is 2050 or more and 2600 or less, and an air permeability under a 20 kPa differential pressure is 0. Non-coated woven fabric for air bags, which is less than 25 L / cm 2 / min. [Selected figure] Figure 2

Description

  The present invention relates to a non-coated woven fabric for an air bag and an air bag using the same.

  In recent years, under the influence of heightened safety awareness and changes in safety regulations, not only safety measures that assume frontal collisions for driver's seat airbags and passenger side airbags in automobiles, but also side collisions. Adoption of curtain airbags and side airbags is increasing.

  As compared with a frontal collision, in a side collision, the distance between the side surface of the vehicle receiving an impact and the occupant is short, and it is necessary to deploy the airbag at a higher speed, and it is necessary to minimize air leakage during deployment. For this reason, coated fabrics with low air permeability are generally used for curtain airbags and side airbags.

  However, while there is an increase in the number of parts mounted with airbags due to the increase in safety awareness, there are demands for improving fuel efficiency by reducing the weight of the vehicle body and for reducing the cost of assembly products for reducing the body price. Therefore, as textiles used for an air bag (Hereafter, it may be described as "textile for air bags"), it is desired to replace a heavy-weight and expensive coating textile with non-coating textile.

When considering air permeability as an air bag, it is necessary to consider air permeability from an air bag fabric serving as an air bag main body portion and air permeability from a sewn portion in which air bag fabrics are sewn together. In order to keep the air permeability of the main body portion and the sewn portion as low as possible, it is preferable to use a non-coated woven fabric as a woven fabric having a high density.
The following techniques have been disclosed in the past as techniques for reducing the air permeability of an air bag.

  Patent Document 1 discloses a technique in which two types of polyester fibers having different single yarn fineness are mixed to reduce a gap between single yarns to reduce air permeability.

  Patent Document 2 discloses a technology for weaving a higher density fabric and reducing air permeability by weaving using a cam-driven loom.

  Patent Document 3 provides a fabric for an air bag having high slip resistance and low air permeability by weaving at high density using single yarn fibers having a flat single yarn cross-sectional shape. Is disclosed.

JP-A-8-325888 Unexamined-Japanese-Patent No. 2000-328388 JP, 2006-16707, A

  As described above, although various methods for reducing the air permeability of the non-coated fabric for the air bag have been studied, the non-coated fabric for the air bag has not been developed so low that the air permeability is low enough to substitute for the conventional coated fabric.

  The present invention has been made focusing on the low air permeability and high density of non-coated woven fabric for air bag, and the object is to reduce air leakage less than non-coated woven fabric for air bag developed by the prior art. An object of the present invention is to provide a non-coated woven fabric for an air bag and an air bag using the same, which can also be used at a site which could not be used unless it was a coated fabric for air bag conventionally.

As a result of intensive studies to solve the above problems, the present inventors can weave a non-coating fabric for an air bag containing fibers of a substantially triangular cross section having a specific degree of heteromorphism in the yarn at high density, The present inventors have completed the present invention by finding that the air permeability is lower than conventional non-coated woven fabrics and high slip resistance can be exhibited. The present invention has the following constitution.
(1) The cross-sectional shape is a substantially triangular shape, the singlet fiber having a heteromorphic degree of 1.3 to 2.2, the cover factor (CF) is 2050 or more and 2600 or less, and the air permeability under 20 kPa differential pressure is 0. Non-coated fabric for an air bag having a density of 25 L / cm ² / min or less.
(2) The non-coated fabric for an air bag according to (1), wherein the anti-slip resistance force defined by ASTM D 6479 is 700 N or more and 1200 N or less in an average value in the vertical direction and the horizontal direction.
(3) The non-coated fabric for an air bag according to (1) or (2), wherein the air permeability under 20 kPa differential pressure after folding of the fabric measured by the following method is 0.30 L / cm ² / min or less .
[Air permeability under 20 kPa differential pressure after folding of fabric]
A test piece of 20 cm square is cut out from an arbitrary point excluding the range of 30 cm from both widthwise ends of the fabric, the test piece is folded in half along the fiber axial direction (a), and then in the fiber axial direction (a) Fold it in half along the fiber axis direction (b) orthogonal to it, fold it in half again along the fiber axis direction (a) again, and cut it in half along the fiber axis direction (b) perpendicular to the fiber axis direction (a) Fold it into 5cm square. A load of 50 N is applied to the entire surface of the folded test piece for 1 minute, and then left in a state of being spread in a 20 cm square for 1 minute. The air permeability under a 20 kPa differential pressure is measured with a circle having a diameter of 10 cm centered on the intersection point of the first and second folds as a measurement site.
(4) The change rate of the air permeability under 20 kPa differential pressure after folding of the fabric measured by the method according to (2) to the air permeability under 20 kPa differential pressure of the fabric is 150% or less (1) Non-coated woven fabric for an air bag according to any one of (3) to (3).
(5) The total fineness of fibers constituting the woven fabric is 100 dtex or more and 600 dtex or less, the number of filaments is 40 or more and 200 or less, and the single yarn fineness is 1 dtex or more and 8 dtex or less Non-coated woven fabric for airbags according to
(6) The boiling water shrinkage ratio of the yarn defined in 8.1 of JIS L1013 (1999) is 7% or more and 12% or less, and the yarn is made of nylon fiber in any of (1) to (5) Non-coated textile for air bag as described.
(7) An air bag using the non-coated woven fabric for air bag according to any one of (1) to (6).
(8) Air having a cross-sectional shape other than a round cross-sectional shape, a setting of weft cover factor of 1040 or more at the time of weaving, and an amount of protrusion before weaving of 320 to 350 ° before weaving Method for producing non-coated woven fabric for bags.
(9) The method for producing a non-coated woven fabric for an air bag according to (8), wherein the cross-sectional shape is a polygonal shape and the number of apexes is 3 or more and 6 or less.
(10) The method for producing a non-coated woven fabric for an air bag according to (8) or (9), wherein the cross-sectional shape is a polygonal shape and the number of apexes is three.

  The non-coated woven fabric for an air bag of the present invention can be woven with high density because it contains substantially triangular cross-section fibers having a specific degree of deformation in the yarn, and has lower air permeability than conventional non-coated woven fabric and is slip resistant It is possible to exhibit high characteristics.

It is a figure which shows the nozzle which has a variant cross section, and how to obtain | require the variant degree. It is a cross-sectional schematic diagram which shows an example of the preferable cross-sectional shape of a single yarn fiber, and how to obtain | require the heteromorphism degree of the cross section of the said single yarn fiber. It is a cross-sectional schematic diagram which shows how to obtain | require the cross-sectional shape of another single yarn fiber, and the heteromorphic degree of the cross section of the said single yarn fiber. It is a scanning electron micrograph which shows the cross section of the single yarn fiber obtained in Example 1. FIG. It is a scanning electron micrograph which shows the cross section of the single yarn fiber obtained by the comparative example 3. FIG. It is the schematic of the measuring method of yarn widening ratio.

The non-coated woven fabric for an air bag of the present invention contains single yarn fibers having a substantially triangular cross-sectional shape and a heteromorphic degree of 1.3 to 2.2, and a cover factor (CF) of 2050 or more and 2600 or less, 20 kPa difference It is characterized in that the air permeability under pressure is 0.25 L / cm ² / min or less.
The inventors of the present invention have been able to achieve high density by weaving a fabric for an air bag using substantially triangular cross-section fibers having a specific degree of heteromorphousness instead of conventionally used circular cross-sections and cross-section cross-sections. The present invention has been accomplished by finding that a woven fabric having properties of being able to be woven, having lower air permeability than conventional non-coated woven fabrics and having high anti-slip resistance values can be obtained. Hereinafter, the present invention will be described in detail.

  The material of the fiber constituting the non-coated woven fabric for an air bag of the present invention is not particularly limited, but, for example, an aromatic polyamide fiber such as nylon 66, nylon 6, nylon 46, nylon 12 etc., aramid fiber and the like And polyester fibers such as polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate. In addition, wholly aromatic polyester fibers, ultrahigh molecular weight polyethylene fibers, polyparaphenylene-benzobis-oxazole fibers (PBO fibers), polyphenylene sulfide fibers, polyether ketone fibers and the like can also be used. However, in view of economy, polyester fiber and polyamide fiber are preferable, and nylon 66 made of polyhexamethylene adipamide fiber is preferable from the viewpoint of durability against high temperature gas.

  When nylon 66 is used as a constituent fiber of the non-coated woven fabric for an air bag, it is preferable to use nylon 66 having a relative viscosity of 3.2 or more with sulfuric acid. If the relative viscosity is less than 3.2, the strength required for an air bag fabric may be insufficient. More preferably, it is 3.3 or more, More preferably, it is 3.4 or more. However, if the relative viscosity is too high, not only the polymerization cost increases but also the spinning operability tends to deteriorate. Therefore, the relative viscosity is preferably 3.6 or less, more preferably 3.5 or less.

  The fibers constituting the woven fabric may use, in part or all thereof, fibers obtained from raw materials regenerated from plastic waste. Moreover, the material which comprises a fiber may contain the various additive for improving the process passability in a manufacturing process. As an additive, antioxidant, a heat stabilizer, a smoothing agent, an antistatic agent, a thickener, a flame retardant etc. are mentioned, for example. Furthermore, the fibers constituting the air bag fabric may be raw yarns or those after dyeing.

In the non-coated woven fabric for an air bag of the present invention, it is important to use a single yarn fiber (hereinafter sometimes referred to simply as a substantially triangular cross-sectional fiber) whose cross-sectional shape orthogonal to the fiber axis direction is substantially triangular.
By using the fiber in which the cross-sectional shape of the single yarn fiber is substantially triangular, it is possible to weave with high density on the loom, and a low air permeability woven fabric is obtained. The inventors consider the reason as follows. The fiber whose cross-sectional shape of single yarn fiber is approximately triangular is that the single yarn fiber moves and is packed in a fine-packed state when external force is applied to the fiber, and the reason is that it exhibits high density and low aeration characteristics. It can be considered as one of the
That is, as a result of the single yarn fibers being closely packed with each other by external force applied when the weft yarn is driven in with a weir on the loom or when the weft yarn is restrained by the warp, compared with the fibers having gaps between the single yarn fibers, Even though the fineness is the same, since the actual fiber diameter is small, it is presumed that higher density can be obtained on the loom. In addition, the low air permeability compared to the conventional fabric is that the fabric can be woven with high density, and the voids between the fibers at the time of ventilation are reduced, and the single yarn fibers are closely packed by the pressure applied at the time of ventilation. As a result of the reduction of voids inside the fibers, it is considered that the air permeability in the fibers also decreases.

  As described above, as a reason for the single yarn fiber moving by the external force, when the shape appearing in the cross section orthogonal to the fiber axis direction of the single yarn fiber is substantially triangular, the cross sectional shape is compared with other polygonal fibers. The number of apexes is small, and there is little sticking between single yarns.

The single yarn fiber used in the present invention has a degree of variant of 1.3 or more and 2.2 or less. The degree of heteromorphism is used as an index of the heteromorphic shape of the cross section of the single yarn fiber. In theory, it is preferable that the cross-sectional shape is an equilateral triangle, but in an actual raw yarn, a phenomenon (di-swell phenomenon) occurs when resin melted from the nozzle is extruded, so the cross-sectional shape of single yarn fibers The top is rounded. Therefore, the most preferable variant degree in the present invention is around 1.6. The degree of modification is preferably 1.35 or more and 2.0 or less, more preferably 1.4 or more and 1.8 or less. If the degree of deformation is too small, gaps may occur between the single yarn fibers to reduce the air permeability of the fabric, and at the same time the movement of the single yarn fibers may be suppressed. On the other hand, when the degree of heteromorphy is too large, the unevenness of the fiber surface becomes large, and the adjacent fibers may be caught, which may make it difficult to move the single yarn fiber.
In addition, the change in the degree of modification before and after weaving is small, and normally, the single yarn fiber after weaving has the same degree of modification as the single yarn fiber (raw yarn) before weaving. Accordingly, it is preferable that the degree of deformation of the woven yarn taken out from the woven fabric is also in the above range. The degree of deformation of the single yarn fiber cross section can be determined by the method described in the examples.

  The single yarn fiber according to the present invention, as shown in FIG. 2, connects the apexes (a, b, c) of the substantially triangular (periphery of the single yarn fiber cross section) 34 appearing in the cross section orthogonal to the fiber axis direction. Preferably, a straight line is on the inside or the outer periphery 34 of the outer periphery 34 of the single yarn fiber cross section. Moreover, it is also preferable that the triangle 33 which connected the vertex a, b, and c of the said substantially triangle 34 by a straight line exists inside the outer periphery 34 of a single yarn fiber cross section. This relationship is obtained by the intersection 22 of the vertical bisector 21 of the line segments ab, bc and ca connecting the apexes a, b and c of the outer periphery 34 of the single yarn fiber cross section and the outer periphery 34 of the single yarn fiber cross section Is synonymous with being located outside the triangle 33. As a single yarn fiber according to the present invention, it is ideal that the shape appearing in the cross section orthogonal to the fiber axis direction is an equilateral triangle. In this case, the triangle 33 and the outer periphery 34 of the single yarn fiber cross section coincide with each other.

  On the other hand, for example, as in the fiber shown in FIG. 3, a shape 34 'appearing in a cross section orthogonal to the fiber axis direction and a vertex (a', b ', If the straight line connecting c ') (for example a'b') and / or the shape (triangle 33 ') is not in the above relation, ie triangle 33' is not within the outer periphery 34 'of the fiber cross section In fact, this means that the cross-sectional shape of the single yarn fiber is close to Y-shape) and the amount of voids between the single yarn fibers increases, so the air permeability not only becomes high, but also inside the fiber (multifilament) Tend to be difficult to move.

  In order to obtain a single yarn fiber which is easy to move in the multifilament by an external force, it is preferable to lower the degree of fiber entanglement. The number of interlacing at the raw yarn production stage is preferably 5 / m or more and 30 / m or less in order to perform high-density weaving. The degree of interlacing of the yarn at the stage of being woven from the woven fabric is preferably 20 yarns / m or less, more preferably 15 yarns / m or less, and still more preferably 8 yarns / m or less in average of warp and weft. There is no particular lower limit, and the degree of intermingling may be 0 / m. If the degree of entanglement is within the above range, the movement of single yarn fibers is unlikely to be inhibited, and a high density, low air permeability non-coated fabric for an air bag can be obtained. The degree of interlacing at the yarn stage is more preferably 8 / m or more, and still more preferably 10 / m or more. The upper limit of the degree of interlacing is more preferably 28 or less and still more preferably 25 or less.

  The ease of movement of single yarn fibers constituting the above-mentioned fibers can also be grasped from the widening ratio of yarns (fibers) taken out of the non-coated woven fabric for an air bag. Therefore, in the present invention, the widening ratio of the yarn is moved so that the single yarn fibers are closely packed in the fibers by an external force such as tension, and the single yarn fibers are displaced at the interface with the adjacent single yarn fibers. Therefore, it is used as an index indicating the movement in the direction orthogonal to the fiber axis. A large value of the spreading factor means that the single yarn fiber is easy to move due to the influence of external force.

  It is preferable that the fiber spreading factor of the uncoated woven fabric for an air bag is woven and taken out is 2.4 or more and 3.5 or less. If the yarn widening ratio is less than 2.4, the single yarn fibers are difficult to move, and when an external force is applied to the fibers, the single yarn fibers are finely packed and difficult to weave at a higher density. Tend to be Therefore, the yarn widening ratio is more preferably 2.5 or more, still more preferably 2.6 or more. If the yarn widening ratio is higher than 3.5, the single yarn fibers become too easy to move, and the gap between the single yarn fibers can not be kept tightly packed, and the air permeability may be increased. More preferably, it is 3.4 or less. The yarn widening ratio is obtained by the measurement method described later.

  The mechanical properties of the fibers constituting the non-coated woven fabric for an air bag are preferably such that the cutting strength is 7.0 cN / dtex or more, more preferably from the viewpoint of satisfying the mechanical properties required for the air bag. It is 7.5 cN / dtex or more. The higher the cutting strength, the better. However, in consideration of the yield at the time of production, the chopping strength is preferably 9.5 cN / dtex or less, more preferably 9.0 cN / dtex or less.

  The single yarn fineness of the filament constituting the fiber is preferably 1 dtex or more and 8 dtex or less. If the single yarn fineness is too large, the number of single yarn fibers per the same fineness decreases, so the air permeability inside the fiber may be high, and it may be difficult to obtain a low air permeability airbag. On the other hand, if the single yarn fineness is too small, the productivity of fibers may be reduced. More preferably, it is 2 dtex or more and 7.5 dtex or less, and still more preferably 2.5 dtex or more and 6.5 dtex or less.

  The number of filaments constituting the fiber is preferably 40 or more and 200 or less. If the number of filaments is less than 40, the air permeability inside the fiber tends to be high, and a low air bag tends to be difficult to obtain. On the other hand, when the number of filaments exceeds 200, the productivity of fibers tends to decrease. The number of filaments is more preferably 50 or more, further preferably 60 or more, more preferably 180 or less, still more preferably 160 or less.

  The total fineness of the fibers is not particularly limited, but is preferably 100 dtex or more and 600 dtex or less, more preferably 150 dtex or more and 500 dtex or less, still more preferably 200 dtex or more and 500 dtex or less, and preferably 235 dtex or more and 470 dtex or less Is particularly preferred. If the total fineness is less than 100 dtex, there is a risk that tensile strength and tear strength may be insufficient when used as an air bag fabric. On the other hand, when it exceeds 600 dtex, the strength problem hardly occurs, but the flexibility required for the air bag is impaired, and the surface of the fabric becomes hard, which may damage the skin of the human body at the time of collision. .

  Although the structure of the non-coated woven fabric for an air bag is not particularly limited, plain weave is preferable in consideration of uniformity of the physical properties of the woven fabric. The woven yarn may not be the same in warp and weft, and the thickness, the number of yarns, the type of fiber, etc. may be different as long as the strength, air permeability and the like satisfying the performance as an air bag can be obtained. From the viewpoint of providing a low air permeability fabric, in 100% of the fibers constituting the non-coating fabric for an air bag (total of warp and weft), the cross-sectional shape described above is substantially triangular, and has a specific heteromorphic degree It is preferable to use 25% or more of fibers (multifilaments) containing single yarn fibers. More preferably, it is 50% or more, and most preferably 100%.

The cover factor (CF) calculated by the following formula 1 is 2050 or more and 2600 or less for the non-coated woven fabric for an air bag. If the cover factor exceeds 2600, the tension applied to the warp at the time of weaving may damage the warp and cause fuzzing, making it difficult to weave in high density. In addition, if it is less than 2050, it may be difficult to obtain the low air permeability necessary for the air bag. The cover factor is more preferably 2200 or more and 2500 or less.
CF = (warp density [book / 2.54 cm]) × ((warp fineness [dtex] × 0.9) + (weft density [book / 2.54 cm] × √ (weft fineness [dtex] × 0.9) ) (Equation 1)

The air bag non-coated woven fabric has an air permeability (high pressure air permeability) of at most 0.25 L / cm ² / min under a differential pressure of 20 kPa. If the high pressure permeability exceeds 0.25 L / cm ² / min, the low permeability required for an air bag can not be secured. High air permeability is more preferably less 0.20L ^/ cm 2 ^/ min, more preferably not more than 0.15L ^/ cm 2 ^/ min.

The non-coated woven fabric for an air bag preferably has a high pressure air permeability (air permeability under a differential pressure of 20 kPa) of 0.30 L / cm ² / min or less after being folded by a predetermined method. Because the air bag fabric is stored in a predetermined place in the vehicle in a folded or randomly compressed state, if the air permeability after folding is high, it is difficult to secure the internal pressure necessary to restrain the occupant when the air bag is deployed. Tend to be High pressure air permeability after folding, more preferably not more than 0.25L ^/ cm 2 ^/ min, more preferably not more than 0.20L ^/ cm 2 ^/ min. The high pressure air permeability after folding of the air bag fabric can be determined by the method described in the examples.

Furthermore, it is preferable that the air permeability change rate (following Formula 2) represented by ratio of the high pressure air permeability before and behind folding is 150% or less for the non-coating fabric for air bags. If the air permeability change rate exceeds 150%, it may be difficult to secure the internal pressure necessary for restraining the occupant when the air bag is deployed. More preferably, it is 130% or less, still more preferably 120% or less.
Permeability change rate (%) = (High pressure air permeability after folding) / (High pressure air permeability before folding) × 100 (Equation 2)

  In the non-coated woven fabric for an air bag, it is preferable that the anti-slip resistance force defined by ASTM D6479 is an average value of 700 N or more and 1200 N or less in the vertical direction and the horizontal direction. If the anti-slip force is less than 700 N, the sewn parts will open during deployment of the air bag, and the air permeability of the air bag will deteriorate. On the other hand, when the anti-slip resistance exceeds 1200 N, the fabric becomes rigid, so the flexibility required for the air bag is lost, and the fabric surface becomes hard, which may damage the skin of the human body at the time of a collision. is there. More preferably, it is 750N-1100N, More preferably, it is 800N-1050N.

Next, the fibers used for the non-coated woven fabric for an air bag of the present invention and the method for producing the non-coated woven fabric for an air bag using the same will be described.
The fibers constituting the non-coated woven fabric for an air bag may be produced according to a conventional method. For example, the raw resin is melt-extruded using a single- or twin-screw extruder, weighed using a gear pump, extruded through a suitable metal non-woven filter into a nozzle to form a fibrous melt, and then fibrous melt The material is allowed to pass through a heating cylinder directly below the nozzle and cooled with cooling air, a spinning oil is applied, wound around a take-up roller, and stretched as it is, and then subjected to an entangling treatment to form a filament.

  As described above, the fibers constituting the non-coated woven fabric for an air bag of the present invention are required to have a substantially triangular cross-sectional shape and to have a specific degree of deformation. In order to obtain such fibers, it is preferable to spin using a nozzle having a suitable shape. For example, using a nozzle in which three discharge holes are arranged such that the outer edge surrounding the discharge hole has a substantially triangular shape, bonding the discharged resin by a die-swell phenomenon in which the molten resin spreads immediately after being discharged from the nozzle Method of forming into a thread-like shape; Method of discharging molten resin from three linear slits using a nozzle having a Y-shaped discharge hole shape; or three substantially isosceles triangles as shown in FIG. 1 For example, there is a method of discharging the molten resin from a nozzle having a discharge hole shape in which adjacent substantially isosceles triangles are disposed so as to share the end portion of the base.

Since the degree of deformation of the fiber cross section largely depends on the degree of deformation of the nozzle, in order to obtain a fiber of a substantially triangular cross sectional shape having a specific degree of deformation, a nozzle having a discharge hole shape as shown in FIG. 1 is used Is preferred. By using the nozzle of this shape, it is easy to adjust the degree of deformation of the fiber cross section.
The degree of variant of the nozzle is preferably 2 or more and 10 or less, and more preferably 3 or more and 8 or less. If the degree of nozzle irregularity is too small, the fiber cross section after spinning will tend to be close to the round cross section. On the other hand, when the degree of deformation of the nozzle is too large, the cross section of the fiber after yarn production tends to be flat or near Y-shaped.

  The degree of deformation of the nozzle can be represented by the ratio of the radius of the circumscribed circle of the nozzle hole to the radius of the inscribed circle (the radius of the circumscribed circle / the radius of the inscribed circle). Describing specifically with reference to FIG. 1, the circumscribed circle 11 is a circle which is represented by a broken line in FIG. 1 and which passes through the apexes A, B and C of the discharge hole outer edge 13 of the nozzle. On the other hand, the inscribed circle 12 is represented by an alternate long and short dash line in FIG. 1, and when the discharge hole is regarded as a shape consisting of three substantially isosceles triangles having A, B and C as apexes, adjacent isosceles triangles. Is a circle passing through the intersections D, E, F of the equilateral sides of.

  The nozzle temperature may be appropriately determined according to the resin to be used, but when using polyamide fiber such as nylon 66, for example, the temperature of the nozzle is preferably 280 ° C. or more and 320 ° C. or less. If the nozzle temperature is too low, the pressure loss when passing through the nozzle may become large and spinning may become difficult. On the other hand, if the nozzle temperature is too high, polymer degradation and gelation are likely to occur, which may cause clogging of the filter or thread breakage, which not only reduces productivity but also reduces fiber strength. There is a risk.

  In order to make the temperature of the nozzle surface uniform, a device such as a heat insulating cylinder or a heating cylinder may be installed between the nozzle and the take-up roll for winding the fiber. The length of the heat insulating cylinder or the heating cylinder is preferably in the range of, for example, 2 cm or more and 50 cm or less from the nozzle. If the length of the heating cylinder is shorter than 2 cm, the cooling air from the subsequent cooling step may enter, the temperature of the nozzle surface may become uneven, and fineness unevenness may easily occur between the fibers. On the other hand, when the heat insulating cylinder or the heating cylinder is longer than 50 cm, periodic longitudinal yarn spots called so-called resonance tend to occur easily.

  The temperature of the cooling air used to cool the melted yarn is preferably in the range of 15 ° C. or more and 30 ° C. or less. If the temperature of the cooling air is lower than 15 ° C., there is a possibility that the difference in physical properties such as the degree of heterogeneity, strength, etc. becomes large between fibers, and if the temperature of the cooling air becomes higher than 30 ° C. There is. The temperature is more preferably 18 ° C. or more and 28 ° C. or less, still more preferably 20 ° C. or more and 25 ° C. or less.

  The wind speed of the cooling air is preferably in the range of 0.1 m / sec to 1 m / sec. If it is less than 0.1 m / sec, it may be difficult to sufficiently cool the thread, and fineness unevenness may easily occur between the fibers. On the other hand, when the wind speed exceeds 1 m / sec, the cooling speed is likely to differ between the cooling air upstream and downstream, and there is a possibility that fineness unevenness may occur between the fibers.

Moreover, when winding up the cooled yarn, it is preferable to make draft ratio calculated by the following formula 3 into 100 or more and 150 or less.
Draft ratio = take-up roller speed [m / min] / (single-hole volume discharge amount [m ³ / min] / nozzle hole cross-sectional area [m ² ]) (Equation 3)
If the draft ratio is less than 100, the yarn swaying becomes large, which tends to cause fusion between the fibers and breakage of the yarn. On the other hand, when the draft ratio is greater than 150, the alignment unevenness of molecular chains in the cross section of single yarn fiber, in particular, the difference in the alignment of molecular chains near the center of the cross section and near the apex of a substantially triangular shape becomes large. Tends to occur.

  The stretching ratio is preferably 4.5 times or more and 4.9 times or less. If the draw ratio is less than 4.5 times, the fiber strength may be reduced. On the other hand, if the draw ratio is higher than 4.9 times, alignment unevenness of molecular chains occurs in the filament cross section, cracks are likely to occur in the filament, and fiber strength may be reduced, or yarn breakage may occur during fiber production. There is a risk.

  The temperature at the time of stretching is preferably in the range of 20 ° C. or more and 240 ° C. or less, although it depends on the subsequent weaving method. If the stretching temperature is lower than 20 ° C., thread breakage may occur before the required stretching ratio is reached. On the other hand, when the stretching temperature exceeds 240 ° C., the yarn tends to melt and the stretching becomes difficult.

  In the fibers used for the non-coated woven fabric for an air bag of the present invention, it is preferable to minimize entanglement by fluid treatment such as air pressure, that is, so-called interlace treatment. Specifically, it is preferable that the interlacing degree of fibers at the raw yarn stage is 5 / m or more and 30 / m or less. In order to set the degree of interlacing within the above-mentioned range, it is preferable to perform an interlace process to adjust the degree of interlacing of fibers after the end of the drawing process and before winding up.

  If the degree of entanglement is too small, fluff is likely to be generated in the next step, that is, the weaving step, and the quality of the fabric may be degraded. On the other hand, if the degree of entanglement is too high, the movement of single yarn fibers may be hindered by the fact that many entanglements remain even in the state of the woven fabric after weaving. Therefore, the degree of interlacing at the yarn stage is preferably within the above-mentioned range.

  Although the boiling water shrinkage rate is not particularly limited in the fibers used for the non-coated woven fabric for an air bag of the present invention, the boiling water shrinkage rate is 7% or more and 12% or less in order to enhance the slip resistance of the woven fabric for an air bag. It is preferable to do. If the boiling water shrinkage rate is too small, when processing is carried out in the process of manufacturing the fabric for an air bag, there is a possibility that the anti-slip resistance force may be reduced because the fibers are less tightened. On the other hand, if the boiling water shrinkage rate is too large, it is not preferable because the stability of the fiber with time is poor, and the dispersion of the physical properties of the fabric becomes large depending on the production lot of the fabric depending on the storage period. More preferably, it is 8% or more and 11% or less, and still more preferably 8.5% or more and 10% or less.

  The method of weaving the non-coated woven fabric for an air bag is not particularly limited, and a conventionally known method may be used. For example, the warp tension at the time of weaving is preferably 0.1 cN / dtex or more and 0.5 cN / dtex or less. More preferably, it is 0.15 cN / dtex or more and 0.4 cN / dtex or less, and more preferably 0.18 cN / dtex or more and 0.35 cN / dtex or less. When the warp tension is lower than 0.1 cN / dtex, it is difficult to weave with high density, and the degree of entanglement of the warps tends to be maintained, and the low aeration required for the air bag when the fabric is made In some cases, it may be difficult to obtain gender. If it is higher than 0.5 cN / dtex, the force applied to the warp may be too large to cause fuzz.

  The loom used for weaving is not particularly limited, and a water jet room, an air jet room, a rapier room, or a multi-phase loom is preferably used. A water jet room is preferable from the viewpoint of speeding up, widening, or machine price.

  The operation method of the loom used for weaving is not particularly limited, and may be, for example, a crank-type opening loom or a cam-type opening loom. However, from the viewpoint of increasing the density of the fabric, it is preferable to use a cam-type opening loom with a long opening time of the weir, as it is possible to stabilize the weft traveling stably and perform higher-density weaving as known. .

  When weaving a non-coated woven fabric for an air bag, the number of revolutions of the loom is preferably 400 rpm or more and 1000 rpm or less. If the loom rotation speed is too slow, productivity is impaired, and on the other hand, if the loom rotation speed is too fast, it is difficult to stably weave in high density, which is not preferable. More preferably, they are 500 rpm or more and 900 rpm or less, more preferably 550 rpm or more and 800 rpm or less.

  In weaving a non-coated woven fabric for an air bag, it is very important to stably run the weft in order to improve the weaving efficiency. In order to realize stable weft flight, it is one condition that the opening area created by warping up and down is sufficiently secured at the time of weft insertion, but weaving the fabric with higher density In this case, weaving is difficult because the opening from the temple holding the woven fabric is not sufficiently secured.

  The non-coated woven fabric for an air bag containing substantially triangular cross-section fibers according to the present invention can be woven while suppressing the pre-wetting sagging, so that weaving efficiency can be improved even when weaving under higher density conditions. The inventors have found that it can be maintained equal to time. That is, in the substantially triangular cross-section fiber of the present invention, the single yarn fibers are closely packed with each other by an external force applied when the weft yarn is driven by a weir on the loom or when the weft is restrained by a warp. Since the diameter of the actual fiber is smaller at the same denier as compared with the fiber having a gap, it is presumed that higher density weaving can be performed on the loom.

  In order to suppress the amount of extrusion even when woven at a higher density than in the past, it is necessary that the fibers have a close-packed shape without gaps between single yarn fibers when subjected to an external force. Therefore, it is not limited to the substantially triangular cross-sectional fiber that the amount of protrusion is suppressed, and other shapes such as a regular hexagonal shape, a rectangular shape such as a polygonal shape, and a rhombus shape may be considered. However, the substantially triangular cross-sectional fiber shape of the present invention is preferable from the viewpoint of ease of movement of fibers constituting the fabric, low ventilation of the fabric, and low permeability even after folding.

In particular, when performing high-density weaving in which the weft cover factor (cf) determined by the following equation 4 is 1040 or more at the time of weaving, it is preferable to use a modified fiber represented by a substantially triangular cross-section fiber. When it is desired to develop high density and low aeration characteristics, it is preferable that the interstices between the fibers have a linear shape, so a polygonal shape is preferable. It is also preferable that two or more triangular cross-sectional shapes and other polygonal shapes be connected. Therefore, there is no problem at all even with a shape such as a rhombus shape biased in a square shape. However, the more the vertices of the polygonal shape, the closer to the round cross section, and the more complicated the shape, the easier it is to create gaps between single yarn fibers when receiving external force, so the number of vertices is 3 or more and 6 or less. Is preferred. More preferably, they are three or more and four or less, and still more preferably three substantially triangular cross-section fibers.
Weft yarn at the time of weaving: weft thread setting [book / 2.54 cm] × √ (weft fineness [dtex] × 0.9) (Equation 4)

As one index to check that the open area is sufficiently secured, there is a method to check the protrusion of the ear. The overhang of the ear tends to increase as compared with the central part of the fabric, and is also a factor that hinders the stable flight of the weft.
The reason for the difference in the amount of protrusion between the ear and the central part of the fabric is that in the central part of the fabric, the adjacent warps apply tension to the weft along the fiber axis, so that the crimp of the warp is formed strongly. It is inferred that there is a difference in the length of the warp at the fabric center and at the ear because the weft is loosened and the crimp of the warp is weak because there is no warp on one side.

  The amount of extrusion measured by the predetermined method described in the examples is preferably 320 ° or more and 350 ° or less. In this measurement using a strobe, the above-mentioned overhang is used to record the point when the weft threads are driven after setting the weft thread at 0 ° = 360 ° and the point at which the wedging on the nozzle side will occur. It is an indicator that the smaller the amount, the larger the amount of exfoliation. If the bending amount is smaller than 320 °, the opening area is not sufficiently secured, the weft yarn flight is not stable, and the weaving efficiency is not increased. When the overhang amount is greater than 350 °, it is an area that can not be woven as a virtually dense fabric. More preferably, they are 325 degrees or more and 340 degrees or less, and more preferably 327 degrees or more and 335 degrees or less.

  As an index indicating the weaving efficiency, there is the number of stops of weft threading. As described above, when stable weft flight is not realized with unreasonable densification, or weaving conditions such as warp tension and loom timing are not properly set, weft yarn can not be driven, and looms It will stop. It is preferable that the number of stops of weft driving in weaving an air bag fabric is 4 times / 100 m or less. If it stops more than this, production efficiency will fall and it is unpreferable. More preferably, it is 3 times / 100 m or less, still more preferably 2 times / 100 m or less.

The processing method after weaving of the non-coated woven fabric for an air bag is not particularly limited. Therefore, any processing may be applied as long as the characteristics of the present invention described above, that is, the characteristics that single yarn fibers move in the fabric due to the influence of external force can be maintained. Examples of the method of processing the non-coated woven fabric for an air bag after weaving include heat treatment such as scouring treatment, drying, heat setting and the like. These may be implemented alone or in combination of two or more.
Specifically, the combination of the method of processing the woven fabric after weaving is a method of naturally drying a green machine woven by a water jet room, or an embodiment subjected to a heat treatment step for drying; a raw machine woven by various weaving machines as a scouring step After application, the embodiment to be subjected to the heat treatment step for drying; the embodiment to be subjected to the heat treatment step for heat setting after subjecting the raw machine woven by various looms to the scouring step; Of course, it is also possible to cut and sew the woven fabric (textile machine) as it has been woven on the loom without being subjected to the above-described processing steps to form an air bag.

  First, an embodiment in which a green machine woven in a water jet room is naturally dried or subjected to a heat treatment step for drying will be described (hereinafter, may be referred to as a first embodiment). When the heat treatment process at a specific temperature is performed, the heat treatment temperature (drying temperature) of the greenware is set to 20 ° C. or more and 190 ° C. or less. Preferably they are 40 degreeC or more and 160 degrees C or less, More preferably, they are 60 degrees C or more and 140 degrees C or less. The heat treatment time (drying time) is preferably 10 seconds to 5 minutes. More preferably, it is 20 seconds or more and 3 minutes or less, still more preferably 30 seconds or more and 2 minutes or less. In the heat treatment step, the method is not particularly limited as long as the greenware can be heat treated at the above temperature. Therefore, the apparatus for carrying out the heat treatment step is not particularly limited. For example, an apparatus used for drying fabric, such as a dryer (dryer type heating furnace) using hot air as a heating medium, a cylinder dryer using hot air or steam as a heating medium, Any one can be used. In the first embodiment, instead of the heat treatment step, the raw fabric after weaving may be naturally dried to complete the air bag fabric.

  After the raw loom woven with various looms is subjected to the scouring step, in the embodiment to be subjected to the heat treatment step for drying (hereinafter, may be referred to as the second aspect), the raw loom is woven at 50 ° C to 100 ° C. Apply warm water treatment to the water tank (refining process). In the warm water treatment, the fabric is shrunk while the oil agent, sizing agent and the like applied in the spinning process and the weaving process are removed from the fabric. When the temperature of water is less than 50 ° C., it may be difficult to shrink the fabric sufficiently. The temperature of water is more preferably 60 ° C. or more and 98 ° C. or less, still more preferably 70 ° C. or more and 95 ° C. or less. The hot water treatment is preferably performed for 10 seconds or more and 3 minutes or less. More preferably, it is 20 seconds or more and 2 minutes or less, and still more preferably 30 seconds or more and 1 minute or less. Examples of water used in hot water treatment include tap water and pure water, and surfactants such as sodium alkylbenzene sulfonate, alkaline scouring agents such as soda ash, enzymes, and aqueous solutions of enzymes or organic solvents. You may use it.

  The warm water treatment is preferably carried out while applying a tension of 0.040 cN / dtex or less in the warp direction of the green machine. By performing the warm water treatment under a predetermined tension, the yarn in the living machine can be rearranged by sufficiently shrinking the fabric. In addition, in the case of using polyamide fiber such as nylon 66, hydrogen bonds in the fiber are more easily broken due to the presence of water, which makes it possible to obtain a more flexible base fabric. When the tension in the warp direction exceeds 0.040 cN / dtex, it becomes difficult for the fabric to shrink freely during warm water treatment, and the fabric itself becomes close to a heat-fixed state in a tension state so that single yarn fibers tend to move There is a risk of being easily damaged.

Next, the woven fabric that has undergone the scouring step (warm water treatment) is subjected to a heat treatment step. In the heat treatment step according to the second aspect, it is preferable to dry the fabric without heat setting. For the same reason as the warm water treatment, the tension in the warp direction in the heat treatment (drying) step is also preferably 0.040 cN / dtex or less.
The heat treatment temperature (drying temperature) is preferably 150 ° C. or less from the viewpoint of securing the low air permeability of the fabric for an air bag. More preferably, it is 140 ° C. or less. The drying temperature is preferably low, but if it is too low, the drying time will be long, which is not industrially preferable. Preferably it is 100 degreeC or more, More preferably, it is 110 degreeC or more. The heat treatment time is preferably 10 seconds to 5 minutes. More preferably, it is 20 seconds or more and 3 minutes or less, still more preferably 30 seconds or more and 2 minutes or less.

  In the embodiment in which the green machine woven by various looms is subjected to a scouring process and then subjected to a heat treatment process for heat setting (hereinafter sometimes referred to as the third aspect), water of relatively low temperature in the scouring process, Specifically, water of 30 ° C. or more and 90 ° C. or less is used. The temperature of water is preferably 40 ° C. or more and 80 ° C. or less, more preferably 50 ° C. or more and 70 ° C. or less. If it is in the said temperature range, the oil agent, sizing agent, etc. which are provided by a spinning process or a weaving process can be efficiently removed from textiles.

  As long as water at a specific temperature is used, there is no limitation on the scouring process, and a conventionally known scouring method can be employed. Examples of water used in the scouring step include tap water, pure water, an aqueous solution in which one or more of surfactants such as sodium alkylbenzene sulfonate, alkaline scouring agents such as soda ash, enzymes, and organic solvents are dissolved. You may use it.

  In addition, the refining process may be performed while applying tension in a direction (width direction) orthogonal to the traveling direction of the living machine. For example, the overfeed rate in the running direction of the living machine is preferably 0% or more and 5% or less, more preferably 1% or more and 4% or less, and still more preferably 2% or more and 3% or less. On the other hand, the overfeed rate in the width direction of the lumber is preferably 0% to 3%, more preferably 0.5% to 2.5%, and still more preferably 1% to 2%. is there.

  It is preferable to carry out the scouring treatment for 10 seconds to 5 minutes. More preferably, it is 20 seconds or more and 3 minutes or less, still more preferably 30 seconds or more and 2 minutes or less. The fabric after the scouring treatment (green machine) may be subjected to a heat treatment step after being subjected to dehydration and drying once, but since the fabric is heated to 110 ° C. or more in the heat treatment step, the drying treatment etc. is not performed. The woven fabric after the scouring treatment may be directly subjected to a heat treatment step.

  Subsequently, the woven fabric after the scouring treatment is heat-treated at 110 ° C. or more and 190 ° C. or less (heat treatment step). The heat treatment temperature is preferably 120 ° C. or more, more preferably 130 ° C. or more, and preferably 185 ° C. or less, more preferably 180 ° C. or less, and still more preferably 175 ° C. or less. If the heat treatment temperature is too low, it tends to take a long time to dry the wet fabric by the scouring treatment, which is not only inefficient, but the shrinkage force inherent in the fibers is not sufficiently exerted, and the fibers are not sufficiently separated. There is a possibility that the clogging will be large and the air permeability will be high. On the other hand, if the heat treatment temperature is too high, there is a possibility that the fibers constituting the fabric may be thermally deteriorated and the mechanical strength may be reduced, and the heat shrinkage may give a strong tension to the fabric to harden the fabric. The tendency of the single yarn fiber to move easily may be impaired.

In the third embodiment, the heat treatment is carried out while applying tension to the fabric (heat setting). From the viewpoint of obtaining a fabric with lower air permeability, it is preferable to supply the fabric to the heat treatment step so as to be overfeed. The overfeed rate in the running direction of the fabric is 1.5% or more and 6.0% or less, preferably 2.0% or more and 5.0% or less, and more preferably 2.5% or more and 4.5% or less It is. On the other hand, the overfeed rate (width reduction rate) in the direction (width direction) orthogonal to the running direction of the fabric is 1.0% or more and 4.0% or less, preferably 1.5% or more and 3.5% or less More preferably, they are 2.0% or more and 3.0% or less.
In the case of supplying the raw materials in the overfeed state in both the scouring process and the heat treatment (heat setting) process, in the heat setting process, the overfeed rate in the running direction of the fabric is 0% or more and 5.0% or less. Is more preferably 1.0% or more and 4.0% or less, and still more preferably 1.5% or more and 3.0% or less. On the other hand, the overfeed rate (width reduction rate) in the direction (width direction) orthogonal to the running direction of the fabric is preferably 0% to 3.0%, and more preferably 0.5% to 2.5%. %, And more preferably 1.0% or more and 2.0% or less.

Here, the overfeed rate in the traveling direction of the fabric is a value represented by the following equation 5. The overfeed is achieved by making the speed (V ₁ ) of the feed roller, which is upstream of the heat treatment process and feeds the fabric to the heat treatment process, faster than the speed of the winding roller (V ₂ ), downstream of the heat treatment process. It can be in the state.
Overfeed rate in the traveling direction (%) = (V ₁ / V ₂ ) × 100 (Equation 5)
_{[V 1:} feed roller speed, _{V 2:} the take-up roller speed]

On the other hand, the overfeed rate in the direction (width) orthogonal to the running direction of the fabric is a value represented by the following equation 6. Usually, the heat treatment process is carried out with both ends fixed in the width direction of the fabric fixed, but the distance from one fixed end to the other end is made narrower than the width of the fabric before the heat treatment process is supplied. It can be in the overfeed state.
Overfeed rate (%) in the direction orthogonal to the running direction of the fabric (%) = (1-L ₀ / L ₁ ) × 100 (Equation 6)
[L ₀ : Width of the pre-woven fabric supplied to the heat treatment step (m), L ₁ : Width of the fabric after supply to the heat treatment step (m)]

  If the overfeed rate of the fabric in the traveling direction and width direction is within the above range, movement of single yarn fibers when the fabric is subjected to an external force and spreading of the yarn in the direction orthogonal to the fiber axis suitably occur. So preferred. If the overfeed rate is too small, the yarn is shrunk by heat treatment and an excessive tension is also applied to the single yarn fiber itself, so the single yarn fiber becomes difficult to move even when receiving an external force, and weaving in the direction perpendicular to the fiber axis It becomes difficult for the yarn to spread, and the air permeability may increase. Also, if the overfeed rate is too large, the crimp may be increased by the contraction force of the fibers, which may cause gaps between the fibers to deteriorate the air permeability.

The heat setting may be performed using a known device and heating means in combination. As such a device, for example, a device for holding a textile called a pin tenter or a clip tenter can be mentioned. As a heating means, for example, a dryer-type heating furnace can be used.
The non-coated fabric for an air bag described above is cut, sewn or welded into a desired shape to obtain an air bag.

  EXAMPLES Hereinafter, the present invention will be more specifically described by way of examples. However, the present invention is of course not limited by the following examples, and appropriate modifications may be made as long as the present invention can be applied to the purpose. Of course, implementation is also possible, and all of them are included in the technical scope of the present invention.

(1) Total fineness Measured according to JIS L1095 9.4.1.

(2) Number of filaments Calculated in accordance with 8.4 of JIS L1013 (1999).

(3) Strength, elongation JIS L1017 8.5 a) After leaving in a room where temperature and humidity are controlled at 20 ° C and 65% RH for 24 hours according to the standard time test definition, a tensile tester (made by ORIENTEC Co., Ltd. Strength and elongation were obtained by "Tensiron Universal Material Testing Machine".

(4) Boiling water shrinkage rate It measured by (a) skein shrinkage rate (method A) as described in 8.18.1 of JIS L1013 (1999).

(5) Woven density (number of punched in)
It measured based on 8.6 of JIS L1096 (1999).

(6) Cross-sectional shape, heteromorphism degree The cross-section of five fibers chosen arbitrarily is image | photographed using a scanning electron microscope (magnification 1000-2000). Using commercially available software (e.g., NIS-Elements Documentation), select three substantially triangular vertices (referred to as a, b, c) that appear visually in the cross section of the fiber in the cross-sectional photograph of the obtained fiber, A circle is drawn that passes through the points a, b and c and circumscribes the fiber cross section (the circumscribed circle 31). Then, a vertical bisector 21 of the line segments ab, bc, and ac connecting the apexes is drawn, passes through three intersections 22 of the fiber cross section intersecting with the vertical bisector 21 and inscribed in the fiber cross section Draw a circle (inscribed circle 32). And the value which remove | divided the radius of the said circumscribed circle 31 by the radius of the inscribed circle 32 was made into the heteromorphic degree (refer FIGS. 2-5). The degree of heterogeneity used the average value of five filaments. The deformation degree of the nozzle hole was also calculated by the same method.
In addition, when fiber cross-sectional shape was shapes other than a substantially triangular shape, the circumscribed circle and inscribed circle which contact | connect the outer edge of a fiber cross section were set, and the heteromorphic degree was calculated | required from ratio of these radius. When multiple inscribed circles could be drawn in the fiber cross section, the degree of heterogeneity was determined using the smallest inscribed circle radius.

(7) Yarn widening ratio As shown in FIG. 6, the fibers (multifilaments) 61 are bound so as to have a circumferential length of 20 cm to form a single loop. The fiber 61 is hung by passing the 1-mm diameter Teflon (registered trademark) rod 62 having the wheel portion installed horizontally. At this time, the position of the binding point 64 is adjusted so that the binding point 64 does not come on the Teflon (registered trademark) rod 62 and the lowest point. A load 63 of 1.52 times the total fineness (dtex) of the fibers is suspended at the lowest point of the ring-like fibers 61. The load 63 is hung on the fiber 61 via the bonding yarn 67 using the fiber used in the measurement. In this state, the fiber width (a) of the multifilament located at the top of the Teflon (registered trademark) rod 62 and the fiber located 5 cm above the load point on the side without the binding point 64 (the lowest point of the fiber 61) The thickest fiber width (b) is measured, and the ratio (a / b) of the two is calculated. The fiber was changed, and the above measurement was repeated 10 times, and the average value was taken as the yarn widening ratio. The yarn widening ratio of the woven yarn from the woven fabric was also measured by the same method.

(8) High pressure air permeability (air permeability at 20 kPa differential pressure)
The high-pressure air permeability measuring machine (manufactured by OEM System Co., Ltd.) is used at five measurement sites randomly selected from the part excluding the range of 30 cm from both ends in the width direction of the fabric obtained in Examples and Comparative Examples. Then, the air permeability at 20 kPa differential pressure was measured, and the average value was taken as the high pressure air permeability.

(9) High pressure air permeability after folding (air permeability at 20 kPa differential pressure)
Five test pieces of 20 cm square are cut out from an arbitrary point excluding the range of 30 cm from both ends in the width direction of the woven fabric, and the test pieces are folded in half along the fiber axial direction (a). After folding in half along the fiber axis direction (b) perpendicular to the), and then again along the fiber axis direction (a), along the fiber axis direction (b) perpendicular to the fiber axis direction (a) Fold it in half and fold it into 5cm square. A load of 50 N was applied to the entire surface of the folded test piece for 1 minute, and then left in a state of being spread in a square of 20 cm for 1 minute. A 10-cm diameter circular portion centered on the intersection of the first and second folds is used as the measurement site, and the air permeability under a 20 kPa differential pressure is measured using a high-pressure air permeability tester (manufactured by OEM System Co., Ltd.) Measured. The average value of five test pieces was taken as the high pressure permeability after folding.

(10) Permeability Change Rate Permeability change rate before and after folding was determined by Equation 2 below.
Permeability change rate (%) = (High pressure air permeability after folding) / (High pressure air permeability before folding) × 100 (Equation 2)

(11) Degree of entanglement The degree of entanglement of the raw yarn and the entangled yarn was calculated in accordance with JIS L1013 8.15.

(12) Slip resistance force Measured by ASTM D 6479.

(13) Peeling amount before weaving Using a commercially available stroboscope, the timing at which the kite is completely driven in is 0 ° = 360 °, and the stroboscope is mounted on the dial scale mounted on the water jet loom. The scale was zeroed. After the weft thread was inserted, the timing at which the weir contacts the overhang on the nozzle side was read. It measured 3 times every 1 hour, and recorded the average value of 3 times.

(14) Number of Stops The number of stops of weft threading was measured according to the following Equation 7.
Number of stops of weft thread driving (time / 100 m) = {(s _0- s ₁ ) / f ₁ × 100
(Equation 7)
[S ₀ : total number of stops of weft driving during weaving of certain brand (twice), s ₁ : number of switching of weft yarn yarn cheese (round), f ₁ : total loom weaving length of certain brand (m)]

Example 1
The polyamide 66 resin was melt-extruded using a single-screw extruder, weighed using a gear pump, and the hole shape was processed into the shape shown in FIG. 1 through a metal non-woven filter (NF-07 manufactured by Nippon Seisen Co., Ltd.) The mixture was extruded into a nozzle (deformed degree 6) to obtain a fibrous melt. The fibrous melt is passed as it is through a heating cylinder directly below the nozzle and cooled with cooling air, and then a fatty acid ester-based spinning oil is applied, wound around a take-up roller, and stretched as it is by a known method. The substantially triangular cross section polyamide 66 fiber (substantially triangular cross section yarn) of 144 filaments was obtained. A scanning electron micrograph of this fiber cross section is shown in FIG.
The obtained substantially triangular cross-section yarns were used as warp yarns and weft yarns, and were woven in a crank-opening water jet room. The warp tension was adjusted to be 0.30 cN / dtex, the weft thread count was set to 52.5 / 2.54 cm, and weaving was performed at a loom rotation speed of 600 rpm. The winding angle before weaving at this time was 330 °, the weft flight was stable, and the operation rate was 98%. After weaving, it was passed through a warm water bath at 98 ° C., and the processing tension was adjusted so that the running tension in the warp direction was 0.027 cN / dtex, and the hot water treatment was performed (refining treatment A). Subsequently, the fabric was subjected to a drying treatment under a running tension of 0.027 cN / dtex in the warp direction to obtain a plain weave fabric having a woven fabric density of 57 / 2.54 cm and a woven fabric density of 58 / 2.54 cm. . The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 1.

Example 2
A fiber having a modified cross section was produced in the same manner as in Example 1 except that a nozzle with a modified degree of 4 was used at the time of spinning, and this was woven to obtain a woven fabric. The bending angle before weaving was 327 °, the weft flight was stable, and the operation rate was 96%. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 1.

Example 3
A fiber having a modified cross section was produced in the same manner as in Example 1 except that a nozzle with a modified degree of 8 was used during spinning, and this was woven to obtain a woven fabric. The warp angle before weaving was 328 °, the weft flight was stable, and the operation rate was 97%. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 1.

Example 4
A fiber having an atypical cross section is manufactured in the same manner as in Example 1 except that weaving is performed with a warp tension of 0.39 cN / dtex and weaving number set to 55.5 / 2.54 cm. Then, this was woven to obtain a woven fabric. A plain weave cloth with a density of 60 / 2.54 cm was obtained. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 1.

Example 5
In the same manner as in Example 1 using a nozzle with a degree of heterogeneity of 6 at the time of spinning, a 350 dtex triangular filament polyamide 66 fiber of 108 filaments was obtained.
The obtained triangular cross section yarn was used for warp yarns and weft yarns, and woven in a crank-opening water jet room. The warp tension was adjusted to be 0.39 cN / dtex, and the number of weft threads was set to 61 / 2.54 cm, and weaving was performed at a loom rotation speed of 600 rpm. The winding angle before weaving at this time was 327 °, the weft flight was stable, and the operation rate was 96%. After weaving, it was passed through a 98 ° C. water bath, and the processing tension was adjusted so that the running tension in the warp direction was 0.027 cN / dtex, and the hot water treatment was performed. Subsequently, drying was performed under a running tension of 0.027 cN / dtex in the warp direction to obtain a plain weave fabric having a woven fabric density of 66 / 2.54 cm. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 1.

Example 6
In the same manner as in Example 1, a fiber having an irregular cross section was produced and woven in a cam-opened (dwell angle 60 °) water jet room. The warp tension was adjusted to be 0.39 cN / dtex, the number of weft threads was set to 56.5 / 2.54 cm, and weaving was performed at a loom rotation speed of 600 rpm. The winding angle before weaving at this time was 327 °, the weft flight was stable, and the operation rate was 96%. After weaving, it was passed through a 98 ° C. water bath, and the processing tension was adjusted so that the running tension in the warp direction was 0.027 cN / dtex, and the hot water treatment was performed. Subsequently, a drying process was performed under a running tension of 0.027 cN / dtex in the warp direction to obtain a plain weave fabric having a weave density of 61 / 2.54 cm. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 1.

Comparative Example 1
A polyamide 66 resin is melt-extruded using a single-screw extruder, weighed using a gear pump, and extruded to a nozzle (1.0 degree of heterogeneity) through a metal non-woven filter (NF-07 manufactured by Nippon Seisen Co., Ltd.) It was a fibrous melt. The fibrous melt is passed as it is through a heating cylinder directly below the nozzle, cooled with cooling air, then a fatty acid ester-based spinning oil agent is applied, wound around a take-up roller, and stretched as it is according to a known method. Filament round cross section polyamide 66 fibers were obtained.

The obtained polyamide 66 fiber was used for warp yarns and weft yarns, and woven in a cam-opened water jet room (dwell angle 60 °). The warp tension was adjusted to be 0.39 cN / dtex, and the number of weft threads was set to 52.5 / 2.54 cm, and weaving was performed at a loom rotation speed of 600 rpm. At this time, the amount of bending before weaving was 328 °, the flight of the weft was stable, and the number of stops was 2 times / 100 m. After weaving, the hot water treatment is carried out by adjusting the processing tension so that the running tension in the warp direction is 0.027 cN / dtex through a 98 ° C warm water tank, and then the running tension is 0.027 cN / dtex. Drying was carried out under tension to obtain a plain weave fabric having a density of 57 / 2.54 cm for the woven fabric and a density of 58 / 2.54 cm for the weft. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 2.
The woven fabric obtained in Comparative Example 1 had a high pressure permeability as compared with the woven fabric of the example in which the cross-sectional shape of the single yarn fiber was made of a substantially triangular fiber.

Comparative Example 2
A round cross section polyamide 66 fiber of 470 dtex and 144 filaments is produced according to the procedure of Comparative Example 1 except that the boiling water shrinkage of the polyamide 66 fiber is set to 6.7%, and this is cam-opened (Dwell angle 100 °) Woven with rapier loom. A plain weave fabric with a weave density of 60 / 2.54 cm was obtained by weaving. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 2.
Since weaving was performed with the rapier loom, the loom rotation speed was slow and the productivity of the fabric was poor. In addition, high-pressure air permeability was high even when weaving at high density.

Comparative Example 3
According to the procedure of Comparative Example 1, 235 dtex, 36-filament round cross section polyamide 66 fibers and 235 dtex, 72 filaments were produced respectively, and they were subjected to yarn doubling to produce a 470 dtex yarn having a mixture of single yarn fineness. This was used for warp yarns and weft yarns and woven in a crank-opening water jet room. A plain weave fabric with a weave density of 54 / 2.54 cm was obtained. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 2.
The woven fabric obtained in Comparative Example 3 had a high pressure permeability as compared with the woven fabric of the example in which the cross-sectional shape of the single yarn fiber was made of the substantially triangular fiber. Further, when it is attempted to weave at a higher density than this, since yarns having different fineness of single yarn are mixed, the yarn strength is weak, and it is easy to fuzz, and weaving can not be performed.

Comparative Example 4
In accordance with the procedure of Comparative Example 1, round-section polyamide 66 fibers of 470 dtex, 144 filaments were produced and woven in a crank-opening water jet room. The warp tension was adjusted to 0.60 cN / dtex, the number of weft threads was set to 52.5 / 2.54 c, and weaving was performed at a loom rotation speed of 300 rpm. At this time, the amount of bending before weaving was 318 °, the flight of the weft did not stabilize, and the number of stops was 50 times / 100 m. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 2.
The woven fabric obtained in Comparative Example 4 had a high pressure permeability as compared with the woven fabric of the example in which the cross-sectional shape of the single yarn fiber was made of a substantially triangular fiber. In addition, damage to the warp was observed, and the tensile strength in the warp direction was reduced. The operation rate was also bad.

Comparative Example 5
The shape of the nozzle used is slit-shaped, and the cross section perpendicular to the fiber axis direction is flattened by a known method, the boiling water shrinkage of polyamide 66 fiber is 6.8%, and the crank opening type A fiber was produced in the same manner as in Comparative Example 1 except that a weaving machine was used, and this was woven to obtain a woven fabric. At this time, the amount of bending before weaving was 319 °, the flight of the weft was not so stable, and the number of stops was 105 times / 100 m. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 2.
The high-pressure air permeability was higher than that of the woven fabric of the embodiment in which the cross-sectional shape of the single yarn fiber was made of a substantially triangular fiber. Further, the woven fabric of Comparative Example 5 had a high pressure permeability after folding. It is considered that this is because the laminated structure of the single-filament fiber of flat cross section was disturbed when the woven fabric was folded. Moreover, sliding resistance was also relatively weak.

Comparative Example 6
The procedure of Comparative Example 1 was followed to obtain a 470 dtex, Y-shaped cross-section polyamide 66 fiber of 144 filaments according to the procedure of Comparative Example 1 except that a nozzle with a modified degree of 12 was used during spinning and a loom with a crank opening was used. This was woven to obtain a woven fabric. At this time, the amount of bending before weaving was 319 °, the flight of the weft was not so stable, and the number of stops was 103 times / 100 m. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 2.
The high pressure permeability was higher than that of the example fabric made of fibers of triangular cross section.

Comparative Example 7
According to the procedure of Comparative Example 1 except for using a nozzle with a degree of deformation of 3 during spinning and using a crank-opening loom, a 470 dtex, Y-shaped cross-section polyamide 66 fiber of 144 filaments was obtained. This was woven to obtain a woven fabric. At this time, the amount of bending before weaving was 319 °, the flight of the weft was not so stable, and the number of stops was 103 times / 100 m. The physical properties of the raw yarn and the physical properties of the woven fabric are shown in Table 2.
The high pressure permeability was higher than that of the example fabric made of fibers of triangular cross section.

  According to the present invention, it is possible to provide an air bag non-coated fabric having higher density and lower air permeability, and an air bag using the same.

11 Circles in contact with the discharge holes provided in the nozzles 12 Circles inscribed in the discharge holes provided in the nozzles 13 Outer edges of the discharge holes provided in the nozzles 21, 21 'Cross section orthogonal to the fiber axis direction of single yarn fibers The perpendicular bisector 22, 22 'of the straight line connecting the vertices of the appearing shape, the intersection point of the perpendicular bisector and the outer circumference of the single fiber cross section 31, 31' circumscribed circle 32, 32 'inscribed circle 33, 33 'Triangle connecting the apex of the shape appearing in the cross section of single yarn fiber 34, 34' Cross section perimeter of single yarn fiber 61 Measurement sample (fiber)
62 1 cm diameter Teflon ® bar 63 Load 64 Bonding point 65 Measurement point of the width (a) of the fiber located at the top of the Teflon ® bar when constant tension is applied 66 Constant tension Of the width (b) of the fiber when applying a force 67 Bonding yarn with load using the same yarn as the measurement sample

Claims (10)

The cross-sectional shape is a substantially triangular shape, contains single yarn fibers with a heteromorphic degree of 1.3 to 2.2, the cover factor (CF) is 2050 or more and 2600 or less, and the air permeability at 20 kPa differential pressure is 0.25 L / cm Non-coated woven fabric for air bags, which is ² / min or less.   The non-coating fabric for an air bag according to claim 1, wherein the anti-slip resistance force defined by ASTM D 6479 is 700 N or more and 1200 N or less in an average value in the vertical direction and the horizontal direction. The non-coated fabric for an air bag according to claim 1 or 2, wherein the air permeability at 20 kPa differential pressure after folding of the fabric measured by the following method is 0.30 L / cm ² / min or less.
[Air permeability under 20 kPa differential pressure after folding of fabric]
A test piece of 20 cm square is cut out from an arbitrary point excluding the range of 30 cm from both widthwise ends of the fabric, the test piece is folded in half along the fiber axial direction (a), and then in the fiber axial direction (a) Fold it in half along the fiber axis direction (b) orthogonal to it, fold it in half again along the fiber axis direction (a) again, and cut it in half along the fiber axis direction (b) perpendicular to the fiber axis direction (a) Fold it into 5cm square. A load of 50 N is applied to the entire surface of the folded test piece for 1 minute, and then left in a state of being spread in a 20 cm square for 1 minute. The air permeability under a 20 kPa differential pressure is measured with a circle having a diameter of 10 cm centered on the intersection point of the first and second folds as a measurement site.   The change rate of the air permeability under 20 kPa differential pressure after folding of the fabric measured by the method according to claim 2 to the air permeability under 20 kPa differential pressure of the fabric is 150% or less. Non-coated fabric for an air bag according to any of the above.   The air according to any one of claims 1 to 4, wherein the total fineness of the fibers constituting the woven fabric is 100 dtex or more and 600 dtex or less, the number of filaments is 40 or more and 200 or less, and the single yarn fineness is 1 dtex or more and 8 dtex or less. Non-coated textile for bags.   The non-coated woven fabric for an air bag according to any one of claims 1 to 5, wherein the boiling water shrinkage ratio of the raw yarn defined in 8.1 of JIS L1013 (1999) is 7% or more and 12% or less and is made of nylon fiber. .   An air bag comprising the non-coated woven fabric for air bag according to any one of claims 1 to 6.   Non-airbag non-woven fabric having cross-sectional shape other than round cross-sectional shape, setting of weft cover factor at weaving is 1040 or more, and the amount of extrusion before weaving on the nozzle side is 320 ° or more and 350 ° or less Method of producing coated fabric.   The method for producing a non-coated woven fabric for an air bag according to claim 8, wherein the cross-sectional shape is a polygonal shape and the number of vertexes is 3 or more and 6 or less.   The method for producing a non-coated woven fabric for an air bag according to claim 8 or 9, wherein the cross-sectional shape is a polygonal shape and the number of apexes is three.