JP6105192B2 - Airbag fabric - Google Patents

Description

  The present invention relates to an airbag used for vehicle occupant safety. More particularly, the present invention relates to a coated airbag fabric for use in a lightweight and compact storage airbag.

  An airbag is installed in a vehicle for vehicle occupant safety, and restrains the human body in the event of a collision or protects the human body by a cushioning action between the human body and the vehicle wall or window glass. In recent years, it has become natural to install airbags in the steering section of the driver's seat and the instrument panel of the passenger seat in preparation for a frontal collision, and curtain airbags and side impact airbags have also been installed to deal with side collisions. A number of airbags have been installed in a single vehicle such as a rear window airbag installed in preparation for a rear collision. While air bags are being installed as a safety measure, weight reduction is desired in order to improve the fuel efficiency of automobiles, and compact storage is strongly required due to restrictions on installation locations.

  Until now, in order to reduce the weight of an airbag, it has been proposed to reduce the fineness of the synthetic fibers constituting the fabric. In Patent Document 1 below, a proposal has been made to arrange a plurality of low-definition synthetic fibers in the warp direction and the weft direction, but the total fineness of the fabric constituent unit is increased, which reduces the weight of the fabric. Is not reached. On the other hand, when the total fineness is set to a low fineness, the tensile strength of the coated fabric is lowered. Therefore, the following Patent Document 2 proposes using high-strength fibers.

  However, high-strength fibers did not necessarily contribute to improving the tensile strength of the fabric. In particular, when a high-strength fiber is used to form a woven fabric and a coating is applied to form a non-breathable airbag base fabric, the burst performance of the airbag is not improved. In the case of a coated woven fabric, the higher the strength of the fiber, the more the physical properties of the fiber are not directly reflected in the tensile strength of the coated woven fabric.

JP-A-6-33336 JP 2010-203023 A

  Providing a high-strength coated fabric for airbags that uses high-strength synthetic fibers to improve the tensile strength of the coated fabric and enables lightweight and compact airbags.

The present inventor has conducted extensive research to solve the above problems, and as a result of repeated experiments, by applying a coating to a high-density fabric, the penetration of the coating agent into the fabric is suppressed, and the restraining of the yarn by the coating agent is suppressed. As a result, it was discovered that the strength properties of the synthetic fiber can be directly reflected, and the present invention has been completed based on such knowledge.
That is, the present invention is as follows.

[1] An air comprising synthetic fiber multifilaments coated at a coating amount of 5 to 30 g / m ² , further comprising a shrinking step after weaving, and further a step of coating the woven fabric after shrinkage with addition-reactive solventless silicone It is a manufacturing method of the textile for bags, and (a)-(e) below:
(A) The following formula (1) of the disassembling yarn constituting the coated airbag fabric :
C = P / R formula (1)
{In Formula (1), P is the following Formula (2) :
P = (25.4 / D) × 1000 formula (2)
(. Wherein (2), D is weaving density (the present 25.4 mm) is) is represented by weaving yarn array pitch ([mu] m), and R is the following formula (3):
R = 20 × √ ((d / ρ) / (π ² / √12)) Formula (3)
(In formula (3), d is the total fineness (dtex) of the decomposed yarn, and ρ is the specific gravity of the decomposed yarn). } The cover ratio C represented by } is 1.80 to 1.99 or less on the average in the background direction ;
(B) The following formula (4) indicating the tensile physical properties of the coated airbag fabric :
E = S × 100 / (D × d) (4)
{In Formula (4), S is the tensile strength (N / 25.4 mm) in the tensile test of the fabric, D is the weave density (lines / 25.4 mm), and d is the total fineness of the decomposed yarn ( dtex). } , The strength factor E (cN / dtex) represented by ## EQU1 ## is 7.8 cN / dtex or more in both the longitudinal directions ;
(C) Tensile strength (S) of the coated airbag fabric is 1400 N / 25.4 mm or more in the weft direction ;
( D) A woven fineness W (product × dtex / 25.4 mm), which is a product of the woven density (D) of the coated airbag fabric and the total fineness (d) of the decomposed yarn, is 16,500 to 20,000 ;
(E) The amount of oil applied to the woven fabric before the coating step is 0.05 to 2.5 wt%.
And satisfying the said method.
[2] The method according to [1] above, wherein the tensile strength of the decomposed yarn constituting the coated airbag fabric is 7.5 cN / dtex or more.
[3] The method according to [1] or [2], wherein the coated fabric for airbags has a tenacity factor E (cN / dtex) of 8.2 cN / dtex or more in the weft direction.
[4] The method according to any one of [1] to [3] above, wherein the total fineness of the decomposed yarn constituting the coated airbag fabric is 200 to 420 dtex.
[5] The fabric according to any one of [1] to [4] , wherein the woven fabric before the coating step in which the shrinking step is performed after the weaving has an air permeability at 125 Pa differential pressure of 0.5 cc / cm ² / s or less. the method of.

  The airbag fabric of the present invention is a coated airbag fabric, and exhibits high-strength fabric properties by forming the fabric with high-strength synthetic fibers. The airbag fabric of the present invention exhibits a high-strength fabric physical property even when the fabric is composed of synthetic fibers having a low fineness, so that a lightweight and compact airbag can be manufactured.

It is a figure explaining the simulation airbag used in the Example.

Hereinafter, the present invention will be described in detail.
In a high-strength synthetic fiber, a highly oriented structure is developed on the fiber surface, and the influence on the mechanical properties due to damage on the fiber surface is significant. For this reason, when fibers are fixed and a force is applied between the fiber surfaces, tensile strength measured by a simple tensile test, that is, strong physical properties cannot be exhibited. However, if the fibers are not locally fixed and the action point moves, the original strong physical properties can be utilized.

By setting the woven density of the synthetic fiber woven fabric so that the coating resin does not penetrate into the woven fabric, it is possible to avoid the adverse effect of the resin constraining the synthetic fiber and lowering the physical properties.
When the fabric is composed of multifilament synthetic fibers, the diameter of the outer circumference of the entire multifilament when the cross-section of the filament group forms a lump with the close-packing is the closest packing to the total cross-sectional area of the filament group. It can be converted from the cross-sectional area corrected for the filling density. This is the closest packing equivalent diameter R (μm). When the interval at which the synthetic fibers are arranged as a woven fabric is defined as a weaving yarn arrangement pitch P (μm) and the situation where the woven yarn covers the fabric surface is defined as a cover ratio C, C is represented by the following formula (1).
C = P / R (1)
(However, in Formula (1), P is the weave yarn arrangement pitch (μm) represented by the following Formula (2), and R is the closest packed conversion diameter (μm) represented by the following Formula (3). is there.)
P = 25.4 / D / 1000 (2)
(However, in Formula (2), D is a woven density (this / 25.4mm).)
R = 20 × √ (d / ρ / (π / √12)) (3)
(However, in Formula (3), d is the total fineness (dtex) of a decomposition yarn, and (rho) is the specific gravity of a decomposition yarn.)

In the present invention, the cover ratio C must be 2.18 or less on the average in the background direction. If the cover ratio C is 2.18 or less, the woven yarn arrangement pitch with respect to the closest packing equivalent diameter of the synthetic fibers constituting the fabric is sufficiently small, and the coating resin does not penetrate into the fabric, so that the tensile strength of the fabric is increased. Can do. Furthermore, since the air flow after applying a load to the seam is suppressed and the effect of making it difficult to open the mesh is added, the airbag base fabric has excellent pressure resistance. The cover ratio is preferably 2.15 or less. Since the woven yarn pitch is constrained by the weft, the woven yarn pitch is limited, and the cover ratio is substantially up to 1.80.
The effect of reducing the cover ratio C is more remarkable in the case of a woven fabric using high-strength synthetic fibers.

  The tensile strength of the decomposed yarn constituting the woven fabric is preferably 7.5 cN / dtex or more. This is because the higher the tensile strength of the decomposed yarn, the more potential the coated fabric has to have high strength properties. The tensile strength of the decomposed yarn constituting the woven fabric is more preferably 7.8 cN / dtex or more, and still more preferably 8.3 cN / dtex or more. In addition, in order to comprise with a synthetic fiber with good quality, substantial tensile strength is 10 cN / dtex or less.

  An additional factor to make the coating resin difficult to penetrate the fabric is to smooth the surface of the fabric. If the total fineness of the decomposed yarn constituting the woven fabric is small, the cocoon shape formed by the synthetic fibers floating up and down on the surface of the woven fabric has a smaller heel height and a flatter shape. The total fineness of the decomposed yarn is preferably 500 dtex or less, more preferably 420 dtex or less, and still more preferably 340 dtex or less. On the other hand, 200 dtex or more is preferable in order to satisfy the mechanical properties as an airbag fabric. The total fineness of the decomposed yarn is the fineness in the structural unit of the woven fabric structure. When weaving a structure in which two pieces are aligned during weaving, the total fineness is the fineness obtained by summing up the two pieces that are aligned and constitute the structure.

  Moreover, if the single yarn fineness is small, the arrangement of the multifilament single yarns on the fabric is more likely to take a wider state on the surface than the closest packing equivalent diameter, and the permeation suppression of the coating resin becomes more effective. In order to improve the tensile strength of the woven fabric, the single yarn fineness is preferably 4 dtex or less. From the viewpoint of the woven property as an airbag fabric and the superiority of the fabric quality, the single yarn fineness is preferably 1 dtex or more, more preferably 2 dtex or more.

  As an additional element for smoothing the surface of the fabric, a calendar treatment is also preferable. If it is calendered before coating, it has a surface smoothness, so that it is possible to apply a coating that prevents the penetration of the coating resin. Since the surface smoothness may be maintained from the coating process to the crosslinking step, the calendar condition may be a mild condition. As the airbag fabric, a calendar temperature, for example, from 180 ° C. or lower to room temperature is preferred so that the filament cross section of the synthetic fiber is not deformed so as not to impair mechanical properties such as tear strength. The calendar load can be appropriately selected so that the fabric mechanical properties are not impaired and the surface smoothness is maintained in the coating process, but is preferably 1 to 1000 kg / m.

In order to make it difficult for the coating resin to penetrate into the woven fabric, it is also preferable that the air permeability of 125 Pa defined in the JIS L1096 8.27.1A method (Fragile type method) is 0.5 cc / cm ² / s or less. If the air permeation is 0.5 cc / cm ² / s or less at a low additional pressure, the penetration of the coating resin can be suppressed. The air permeability is more preferably 0.3 cc / cm ² / s or less.

  As an additional element that contributes to prevention of resin penetration during coating, it is also effective to incorporate a penetration inhibitor into the fabric. If the fabric contains oil, penetration of the coating agent is suppressed. The amount of oil attached to the woven fabric is preferably 0.05 to 2.5 wt%. The penetration of the coating agent such as solventless silicone into the woven fabric can be suppressed at 0.05 wt% or more, and more preferably 0.5 wt% or more. On the other hand, if it is 2.5 wt% or less, the coated fabric will hardly fail the combustion test. When the coating agent is a water-based emulsion, it is also preferable to coat the fabric with moisture. It is preferable to coat the woven fabric by immersing it in water or a water-based emulsion solution and reducing the water content to 0.5 to 10 wt%. If the water content is 0.5 wt% or more, it becomes possible to suppress the penetration of the coating agent into the woven fabric. On the other hand, if the water content is 10 wt% or less, the water-containing fabric can be stably formed without fluctuation of the water content due to dripping of water droplets. It is possible to handle.

In the present invention, it is necessary that the synthetic fibers constituting the fabric effectively contribute to the tensile strength of the fabric. Tensile strength S of fabric (cN / 25.4 mm) and fabric weaving fineness W (main × dtex / 25.4 mm) (W = D weave density (main / 25.4 mm) × d (fineness of constituent yarn (dtex) ))) As the ratio of strength E (cN / dtex), the strength E is expressed by the following formula (4).
E = S × 100 / (D × d) (4)
(In the formula (4), S is the tensile strength (N / 25.4 mm) in the tensile test of the fabric, D is the woven density (lines / 25.4 mm), and d is the total fineness of the decomposed yarn. (Dtex).)

  In the present invention, the strength factor E is required to be 7.5 cN / dex or more in both directions. More preferably, it is 7.8 cN / dtex or more, More preferably, it is 8.2 cN / dtex or more. When the strength factor E is 7.5 cN / dtex or more, it can be said that the tensile strength of the fabric can be efficiently expressed. The strength factor E is different from the tensile strength of the decomposed yarn constituting the fabric. The strength factor E is lower than the tensile strength of the decomposed yarn. This is because the fibers are fixed in the woven fabric, and in the tensile test of the woven fabric, force is applied between the fiber surfaces, so that the strong physical properties measured simply by the tensile test of the decomposed yarn are not exhibited. In the present invention, a strength close to the tensile strength of the decomposed yarn of the high strength synthetic fiber is manifested in the tensile strength of the fabric. Even if it is a coating fabric, the strong expression as a fabric is not impaired by coating. The strength factor E does not exceed the strength of the disassembled yarn of the fabric. As a high-quality woven fabric formed of synthetic fibers with stable quality, the tenacity factor E is substantially 10 cN / dtex or less.

  In order to increase the strength factor E, first, it is preferable that the tensile strength of the decomposed yarn constituting the woven fabric is 7.5 cN / dtex or more. Since high tensile strength is a high strength physical property of the coated fabric, higher tensile strength is better.

  On the other hand, in order to increase the strength factor E, it is desirable to increase the weave density and make it difficult for the coating resin to penetrate into the woven fabric. In addition, it is also preferable to lower the total fineness and single yarn fineness of the decomposed yarn, coat the woven fabric after calendering, or coat it after applying a penetration inhibitor.

The tensile strength of the woven fabric is preferably 1300 N / 25.4 mm or more, more preferably 1400 N / 25.4 mm or more. As the tensile strength of the woven fabric is 1300 N / 25.4 mm or more, the mechanical properties as an airbag woven fabric can be satisfied. Assuming that high-grade high-strength fibers are used and the weaving density is the upper limit of weaving, the tensile strength of the fabric is substantially up to 2000 N / 25.4 mm.
Furthermore, in the present invention, it is preferable that the woven fabric has a high woven fineness W (main · dtex / 25.4 mm), and the woven fineness is 15,800 to 21,000 / dtex / 25.4 mm. More preferably, it is 16,500 to 20,000 lines / dtex / 25.4 mm. Since it is a lightweight woven fabric, the woven fineness is preferably 21,000 · dtex / 25.4 mm or less, and if the woven fineness is 15,800 · dtex / 25.4 mm or more, the fabric is used as an airbag fabric. The total amount of fibers required for the mechanical properties of

  The synthetic fiber used in the present invention is a multifilament. The synthetic fiber for airbag is preferably a synthetic fiber having high strength and difficult to melt because of the burst resistance of the airbag. The tensile strength of the synthetic fiber yarn for weaving the woven fabric is preferably 8.5 cN / dtex or more. More preferably, it is 9.3 cN / dtex or more, and still more preferably 9.8 cN / dtex or more. The synthetic fiber is preferably a synthetic fiber having a melting point of 250 ° C. or higher. Examples of such fibers include polyamide fibers made of polyamide 6, polyamide 6,6, polyamide 11, polyamide 12, polyamide 6,10, polyamide 6,12, polyamide 4,6, copolymers thereof, and mixtures thereof. It is done. In particular, it is preferable that the polyamide 6/6 fiber mainly comprises polyhexamethylene adipamide fiber. The polyamide 6/6 fiber used in the present invention includes polyhexamethylene adipamide and polyamide 6, polyamide 6 · I, polyamide 6 · 10, polyamide 6 · T, etc., within a range where the melting point is not less than 250 ° C. Fibers made of polymerized or blended polymers are also preferred.

  As long as the effects of the present invention are not impaired, such fibers may contain various additives that are usually used for improving productivity in the production process and processing process of raw yarn or improving yarn characteristics. Good. For example, a heat stabilizer, an antioxidant, a light stabilizer, a smoothing agent, an antistatic agent, a plasticizer, a thickener, a pigment, a flame retardant, and the like can be included.

  The shrinkage of the synthetic fiber used for weaving can be 5-12% in terms of boiling water shrinkage. High shrinkage yarns that can be densified by shrinking after weaving are more preferable, while uniformity of textile properties such as weaving density is good during processing if the shrinkage rate is not too high. The boiling water shrinkage is more preferably 6 to 12%, and still more preferably 7 to 11%.

  The synthetic fiber used for weaving preferably has a yarn-making oil component content of 0.05 to 2.5 wt%. More preferably, it is 0.5 to 2.0 wt%. An oil agent component here is what is extracted from a textile fabric with the organic solvent hexane, and is the percentage of the weight of the extract with respect to the weight of a polyamide textile fabric. If the content of the oil component is 0.05 wt% or more, there is almost no drop in the cut yarn, single yarn breakage, or strength until weaving. If the content of the oil agent component is 2.5 wt% or less, the oil agent component is hardly scattered and the process is hardly contaminated. It is also preferred that the total amount or at least a part of the synthetic fiber yarn forming oil component remains in the fabric. That is, the oil content in the woven fabric is preferably 0.05 to 2.5 wt%. More preferably, it is 0.5 to 2.0 wt%. An oil agent component here is what is extracted from a textile fabric with the organic solvent hexane, and is the percentage of the weight of the extract with respect to the weight of a polyamide textile fabric. If the content of the oil component is 0.05 wt% or more, the tear strength of the fabric base fabric is hardly lowered. If the content of the oil agent component is 2.5 wt% or less, there is almost no case where the fire burns and fails in the woven fabric combustion test.

  The synthetic fibers used for weaving are preferably subjected to air entanglement during the yarn making process. The number of entanglements is preferably 5 to 35 times / m. From warp alignment to weaving, it is preferable that the number of entanglements is large in order to maintain the convergence of the warp and prevent the loom from stopping. On the other hand, a smaller number of entanglements is preferable in order to improve the weft flying performance and to perform high-speed weaving. Moreover, in warp preparation, the fiber converging property may be reinforced by applying an oil component.

  For weaving, any loom such as a water jet loom, an air jet loom, a rapier loom, or a multiphase loom may be used. In order to perform high-density weaving, it is only necessary to prepare a loom that can be driven stably with a sturdy casing and can be operated with a high warp tension. The woven structure can be various kinds of structures. However, plain weave is preferable for light weight and high strength. At least the main part is preferably a plain weave. Moreover, in the case of bag weaving, it is preferable that the main textile part which comprises an upper and lower panel is comprised by the plain weave structure.

Following the weaving, it is preferable to provide a shrinking step. It is preferable to make a high-density woven fabric before coating by utilizing the heat shrinkage of synthetic fibers. In the shrinking process, hot water shrinkage, hot air shrinkage, high temperature roll shrinkage, and the like are possible. It is also preferable to control the size and tension in the fabric width direction and to control the feeding in the fabric length direction in order to stabilize the fabric quality.
Furthermore, as described above, it is also preferable to add a step of smoothing the surface in the calendar step or applying a penetration inhibitor before the coating step.
It is important that the fabric be a high density fabric prior to coating, for example, a low air permeability fabric such as that used in uncoated airbags.

Coating can be performed by any coating method such as knife coating, roll coating, and dip coating. As the coating agent, various elastomers and resins can be used. In particular, silicone excellent in cold resistance and heat resistance is preferable. Furthermore, addition-reaction type solvent-free silicone is preferable because it can be knife-coated with moderate viscosity and little penetration into the fabric. The coating amount can be implemented from ¹ to 120 g / m ² . In order to reduce the weight of the airbag fabric and stabilize the air flow rate, 5 to 30 g / m ² is preferable.

The coated fabric of the present invention can be sewn into an airbag or used as a bag-woven airbag.
The airbag of the present invention is an airbag device that combines a gas generator and a collision sensor, and includes a driver airbag, a passenger airbag, a side curtain airbag, a side impact airbag, a knee airbag, and a rear windshield airbag. It can be used as a pedestrian protection airbag.
EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited only to these Examples. The following Example 3 is merely a reference example.

About the characteristic evaluation of the textile fabric for airbags in an Example, it implemented by the following method.
(1) Number of entanglements: The number of entanglements (units / m) of the synthetic fiber was determined from the number of entangled portions that can be visually observed by spreading the filament on the surface of a 50 cm long water tank by a water immersion observation method.
(2) Boiling water shrinkage: The boiling water shrinkage (%) of the synthetic fiber was determined according to JIS L-1013 8.18.1 (Method A).
(3) Frazier air permeability: Measured according to JIS L 1096 8.27.1 A method for the woven fabric before coating.
(4) Weaving density: The coating fabric was measured according to JIS L1096 Annex 11A. A densimeter was used.
(5) Fabric weighting: A sample of 10 cm × 10 cm was used for the coated fabric, and the measurement was performed according to JIS L1096 Annex 3.

(6) Decomposed yarn total fineness: According to JIS L1096 Annex 14, the coated fabric was disassembled, and the sample length was measured with respect to the constituent woven yarn of the background.
(7) Decomposed yarn tensile properties: In accordance with JIS L1013 8.5.1, 20 times / 25 cm of twist is applied, a tensile test is performed at a gripping interval of 25 cm and a pulling speed of 30 cm / min. N) was measured to determine the tensile strength (cN / dtex).
(8) Decomposed yarn filament number: The number of constituent single yarns was counted from a cross-sectional photograph of the fabric.

(9) Coating amount: A sample is cut out from a coated woven fabric with a square of about 10 cm, and the area is accurately measured. Finely cut the sample to about 5mm square or less, dissolve the synthetic fiber with a solvent, filter out the coating as a filter residue, thoroughly wash with solvent, weigh the filter residue after drying, and divide by the area of the sample Coating amount (g / m ² ). When the synthetic fiber was a polyamide fiber, 90% formic acid was used as a solvent, and the filter residue was thoroughly washed with formic acid, then washed with water and dried.

(10) Textile oil application rate: 10 g of a textile sample was Soxhlet extracted with 300 ml of n-hexane for 8 hours. The amount of oil component (wt%) in the sample was determined from the dry weight of the n-hexane extract.
(11) Tensile strength of woven fabric: Tensile strength at break (N / 25.4 mm), that is, tensile strength was determined in accordance with JIS L1096 8.12.1 A method (labeled strip method) for the coated woven fabric.

  (12) Stitch load air permeability: cut out two sample base fabrics of 28 cm in length and 15 cm in width, face each other, face 50 cm with a sewing thread which is a 1350 dtex twist yarn at a portion 1 cm from the end of the long side This was sewed by main sewing at times / 10 cm. Thereafter, a load of 1500 N was applied at a speed of 100 mm / min with a tensile tester manufactured by A & D, and then taken out. The dynamic air permeability was measured 10 hours after the removal. The dynamic air permeability was measured using FX3350 manufactured by TEXTEST, with a filling pressure of 300 kPa and a filling capacity of 400 cc, and the air permeability at 50 kPa was measured. In the case of a bag woven fabric, a sample having a length of 28 cm and a width of 15 cm was cut out, and the measurement was performed by applying the same load treatment so that the seam portion was 1 cm from the end.

(13) Quick burst: A woven fabric was cut into a circular shape capable of securing a diameter of 30 cm, and a simulated airbag was sewn in the form of bonding two sheets with the coating surface inside. As shown in FIG. 1A, the airbag is provided with a 100 mm × 80 mm gas inlet, and a portion of the inlet where the airbag is bonded is inserted into a cylindrical gas outlet, Was tightly sealed to prevent leakage. Next, as shown in FIGS. 1 (b) to (d), the gas is introduced after being folded so that each of the simulated airbags spreads in a semicircular shape from side to side and centered on each other so as not to overlap each other. From the opposite side of the mouth to the inlet side, it was folded three times at 10 cm intervals. As a result of a general inspection of the airbag when 970 cc of 15 MPa compressed helium gas was introduced all at once into the airbag, the burst resistance was evaluated according to the following criteria.
○: Neither burst (rupture) nor seam opening.
Δ: There is a seam opening.
X: Burst.

[Example 1]
Sodium hypophosphite, a polymerization catalyst, is added to an aqueous solution containing a neutralized salt of hexamethylenediamine and adipic acid, followed by condensation polymerization in a continuous polymerization apparatus, and then an aqueous solution of copper iodide / potassium iodide is added as a thermal stabilizer. Then, late polymerization was performed to obtain a resin chip. Subsequently, solid phase polymerization was performed to obtain a polyamide 6.6 resin having a relative viscosity ηr of 3.1. The obtained polyamide 6.6 resin was spun, a spinning oil component was added to the discharged yarn, and hot drawing was performed to obtain polyamide 6.6 fiber. The spinning oil was composed of 60 parts by weight of dioleyl thiodipropionate, 20 parts by weight of hardened castor oil EOA (molecular weight 2000) stearate, and 20 parts by weight of higher alcohol EOPO adduct (molecular weight 1500). The number of entanglements was 8 / m. The boiling water shrinkage was 10.5%.

The thus obtained filament yarn having a total fineness of 235 dtex, 72 filaments and a single yarn fineness of 3.3 dtex was woven in a water jet loom without twisting and gluing to obtain a plain fabric. The obtained woven fabric was dried with hot air at 80 ° C. without scouring, and then heated at 180 ° C. for 1 minute with a 2% overfeed in the background using a pin tenter, and then heat-set by rapid cooling. The air permeability of this fabric was 0.2 cc / cm ² / s.

Subsequently, 20 g / m ^{2 of} solventless addition type silicone was coated by floating knife coating, and subjected to crosslinking treatment at 180 ° C. for 1 minute in a hot air oven.
A coated airbag fabric having a warp weave density of 74.0 yarns / 25.4 mm and a weft yarn density of 76.0 yarns / 25.4 mm was obtained.

  Table 1 shows the total fineness of the filament yarn (decomposed yarn) constituting the coated airbag fabric, the tensile strength, the woven density, and the oiling rate of the fabric. The obtained coated fabric had a tensile strength of the decomposed yarn of 8.7 cN / dtex, a tenacity ratio of 8.5 cN / dtex and a weft of 8.2 cN / dtex, and the tensile strength of the fabric was high.

  The fabric had a low seam load air permeability and had a small opening and excellent pressure resistance. Furthermore, when a simulated airbag was sewn from the airbag fabric and attached to the high-pressure gas inlet and the quick burst was evaluated, the fabric was excellent in burst resistance without breaking the bag. These evaluation results are also shown in Table 1.

[Example 2]
The same procedure as in Example 1 was performed except that polyamide 6 • 6 fibers having a slightly lower strength than Example 1 were used. The decomposed yarn strength at this time was 8.2 cN / dtex. The obtained results are also shown in Table 1.
The seam load air permeability of the fabric was low, and the quick burst evaluation was satisfactory.
[Example 3]
The same operation as in Example 1 was performed except that the weave density was lower than that in Example 1. The decomposed yarn strength at this time was 8.2 cN / dtex. The obtained results are also shown in Table 1.
The stitch load air permeability of the fabric increased slightly but was sufficiently low, and the quick burst evaluation was satisfactory.

[Comparative Example 1]
It implemented like Example 1 except having reduced the weave density at the time of weaving. The resulting coated woven fabric had a weave density of 67.0 yarns / 25.4 mm and a weft density of 67.0 yarns / 25.4 mm. The obtained results are also shown in Table 1.
The tensile strength of the woven fabric decreased more than the decrease in the weave density, and the decomposition yarn strength was 8.7 cN / dtex, but the tenacity was 7.0 cN / dtex warp and 7.5 cN / dtex. The seam load ventilation increased, and the quick burst evaluation failed and failed.

[Comparative Example 2]
The same operation as in Example 2 was performed except that the weaving density was lowered during weaving. The resulting coated woven fabric had a weave density of 67.0 yarns / 25.4 mm and a weft density of 67.0 yarns / 25.4 mm. The obtained results are also shown in Table 1.
The tensile strength of the woven fabric decreased more than the decrease in the weave density, and the decomposition yarn strength was 8.2 cN / dtex, but the tenacity was warp 7.0 cN / dtex and weft 7.5 cN / dtex. The seam load air permeability increased, and the quick burst evaluation was broken and failed.

[Comparative Example 3]
Furthermore, it carried out similarly to the comparative example 1 except having used the polyamide 6 * 6 fiber with low intensity | strength. The decomposed yarn strength was 7.1 cN / dtex. The obtained results are also shown in Table 1.
The tensile strength of the fabric was low, the seam load air permeability was high, and the quick burst evaluation was unacceptable due to broken bags.

[Comparative Example 4]
Furthermore, it carried out similarly to Example 1 except having used the polyamide 6 * 6 fiber with low intensity | strength. The decomposed yarn strength was 7.1 cN / dtex. The obtained results are also shown in Table 1.
Even though the fabric density is high and the tenacity is high, the warp is 7.1 cN / dtex and the weft is 6.8 cN / dtex, but the tensile strength of the fabric is low. Although the seam load air permeability was low, the quick burst evaluation failed due to broken bags.

[Comparative Example 5]
A filament yarn having a fineness of 470 dtex, a filament count of 72, and a single yarn fineness of 6.5 dtex was used. The weave density was 46.0 yarns / 25.4 mm and the weft density was 46.0 yarns / 25.4 mm. Except for this, the same procedure as in Example 1 was performed. The obtained results are also shown in Table 1.
Although the cover ratio was large and the woven yarn arrangement pitch was large, the decomposed yarn strength was 7.1 cN / dtex, and the tenacity factor was 7.1 cN / dtex. The tensile strength of the fabric is high, but the seam load air permeability is large, and the gas utilization rate is poor as an airbag.

[Reference example]
Using the woven fabric before coating in Comparative Example 1, woven fabric evaluation, measurement of seam load air permeability, and quick burst evaluation were performed. Although the bag did not break in the quick burst, a seam opening was observed. The seam load air permeability is large, and the gas utilization rate is poor as an airbag.

  The airbag fabric of the present invention exhibits a high-strength fabric physical property even when the fabric is composed of synthetic fibers having a low fineness, so that a lightweight and compact airbag can be manufactured.

Claims (5)

A fabric for an airbag comprising a synthetic fiber multifilament coated with a coating amount of 5 to 30 g / m ² , further comprising a shrinking step after weaving, and further coating the shrinkage fabric with an addition-reactive solventless silicone The following (a) to (e):
(A) The following formula (1) of the disassembling yarn constituting the coated airbag fabric :
C = P / R formula (1)
{In Formula (1), P is the following Formula (2) :
P = (25.4 / D) × 1000 formula (2)
(. Wherein (2), D is weaving density (the present 25.4 mm) is) is represented by weaving yarn array pitch ([mu] m), and R is the following formula (3):
R = 20 × √ ((d / ρ) / (π ² / √12)) Formula (3)
(In formula (3), d is the total fineness (dtex) of the decomposed yarn, and ρ is the specific gravity of the decomposed yarn). } The cover ratio C represented by } is 1.80 to 1.99 or less on the average in the background direction ;
(B) The following formula (4) indicating the tensile physical properties of the coated airbag fabric :
E = S × 100 / (D × d) (4)
{In Formula (4), S is the tensile strength (N / 25.4 mm) in the tensile test of the fabric, D is the weave density (lines / 25.4 mm), and d is the total fineness of the decomposed yarn ( dtex). } , The strength factor E (cN / dtex) represented by ## EQU1 ## is 7.8 cN / dtex or more in both the longitudinal directions ;
(C) Tensile strength (S) of the coated airbag fabric is 1400 N / 25.4 mm or more in the weft direction ;
( D) A woven fineness W (product × dtex / 25.4 mm), which is a product of the woven density (D) of the coated airbag fabric and the total fineness (d) of the decomposed yarn, is 16,500 to 20,000 ;
(E) The amount of oil applied to the woven fabric before the coating step is 0.05 to 2.5 wt%.
And satisfying the said method. Tensile strength of the component yarns constituting the woven fabric for an airbag that is the coating, is 7.5cN / dtex or more, The method of claim 1. The strength index of the coated airbag fabric E (cN / dtex) at the 8.2cN / dtex or higher in both the background direction, The method according to claim 1 or 2. The overall fineness of the component yarn constituting the coated airbag fabric is 200～420Dtex, method according to any one of claims 1-3. The method as described in any one of Claims 1-4 whose air permeability in 125 Pa differential pressure of the textile fabric before the coating process which implemented the shrinkage | contraction process after the said weaving is 0.5 cc / cm < ² > / s or less.

Images