JPH1037039A - Base fabric for non-coated air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base fabric for non-coated air bags which has low air permeability, high flexibility, is lightweight and can be provided inexpensively in no need of the resin coat treatment and calendering. SOLUTION: This is a base fabric for non-coated air bags which are not treated by resin coating or calendering and prepared by weaving multifilament yarns with a total fineness of 140-450 denier, a filament fineness of 1-4 denier, a yarn strength of >=8.0g/de in which the total fineness D (in denier) of the warp and the weft, the width W (in mm) of the warp and the weft, as they are woven, and the cover factor(CF) satisfy the following formulae: D/W of the warp = <=700, D/W of the weft = <=850, and CF=√ (total fineness of the warp) × the warp density + √ (total fineness of the weft) × the weft density =1,900-2,300 [(denier)<1/2> .filament count/inch].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base fabric for a non-coated airbag, which has low air permeability, is flexible, has good storability, uses a small amount of raw yarns, is lightweight and is economical.

[0002]

2. Description of the Related Art In recent years, airbags have been widely used as safety equipment for protecting occupants in the event of a vehicle collision. As a base fabric for the airbag, a material obtained by surface-coating woven fabric with chloroprene rubber, silicone rubber, or the like has been used. However, airbags using such surface-coated fabrics have the drawback of causing considerable cost increases in the coating process and being heavy,
Recently, non-coated fabrics without surface coating have been studied, and some of them have been put into practical use.

However, it has been pointed out that the known non-coated airbag fabric has a higher air permeability than the surface-coated fabric. Therefore, in an airbag base fabric that has not been subjected to a surface coating treatment, it is necessary to prevent air leakage by increasing the weaving density of the woven fabric and reducing the gap between the yarns, but this results in poor flexibility. It may cause damage to the face etc. when the bag is deployed, and the storage capacity due to folding is also worse, and the amount of yarn used per unit area is increased, resulting in higher weight and increased cost. .

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a low air permeability, a flexible and lightweight structure, a low cost and excellent economical efficiency. An object of the present invention is to provide a base fabric for a non-coated airbag.

[0005]

Means for Solving the Problems A non-coated airbag base fabric according to the present invention which can solve the above-mentioned problems is a non-coated airbag base fabric which is not subjected to resin coating treatment and calendering treatment. A multifilament yarn having a total fineness of 140 to 450 denier, a single yarn fineness of 1 to 4 denier and a raw yarn strength of 8.0 g / denier or more is woven, and the total fineness D (denier) of the warp and the weft is determined. The feature lies in that the width W (mm) and the cover factor (CF) of the warp and the weft in the woven state satisfy the relationship of the following formula. D / W of warp = 700 or less D / W of weft = 850 or less CF = √ (total fineness of warp) × warp density + √ (total fineness of weft) × weft density = 1,900-2,300
[(Denier) ^1/2 book / inch]

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The base fabric for a non-coated airbag according to the present invention specifies the total fineness and single yarn fineness of the multifilament yarn constituting the base fabric and the original yarn strength as described above. By specifying the relationship between the total fineness D (denier) of the weft, the width W (mm) of the warp and the weft in the woven state, and the cover factor (CF), it has both excellent air barrier properties and flexibility, It is possible to provide a lightweight and inexpensive base fabric for an airbag. Hereinafter, the constituent materials of the base fabric according to the present invention will be described, and the reasons for determining the above characteristics will be described in detail.

The fibers used in the present invention can be used irrespective of natural or synthetic, but synthetic fibers are preferred for satisfying the above-mentioned characteristics in consideration of economic efficiency. Long fiber multifilament yarns composed of polyamide fibers such as 6, nylon 66 and nylon 46 and polyester fibers mainly composed of polyethylene terephthalate are preferably used. Among them, a long fiber multifilament yarn made of nylon 66 or nylon 46 is particularly preferable from the viewpoint of heat capacity and flexibility.

[0008] The multifilament yarn has a total fineness of 140 due to the strength characteristics required for an airbag, in particular, it is necessary to ensure excellent tensile strength and tear strength.
If the total fineness of the original yarn is less than 140 denier, satisfactory tensile strength and tear strength cannot be guaranteed, and 450 denier. If it is excessively thick, the flexibility as a base cloth becomes poor and not only the possibility of damage to the face and the like when the bag is deployed becomes large, but also the weight becomes heavy and it is not suitable for the purpose of weight reduction. . In addition, if the single yarn fineness is less than 1 denier, the single yarn becomes insufficiently strong, and the warp yarns are liable to break, especially during weaving, and the number of stops of the loom increases, resulting in poor productivity and quality as a woven fabric. Is deteriorated, while the fineness of single yarn is 4
If it is excessively thick beyond denier, it will not be possible to secure a satisfactory low air permeability unless the weaving density is extremely high,
As a result, the flexibility as the base fabric is reduced, and the cost is increased due to the increase in the weight of the raw yarn per unit area, and the weight as the product is also undesirably increased. Considering the above-mentioned strength characteristics, flexibility, productivity, weight, cost, etc., a particularly preferable total fineness of the raw yarn is 210-3.
50 denier, single yarn fineness is in the range of 2 to 4 denier.

In addition, the multifilament yarn used in the present invention needs to have an original yarn strength of 8.0 g / denier or more in addition to the total fineness and single yarn fineness of the above-mentioned yarn. Is an essential requirement for ensuring tensile strength and tear strength as a base fabric for an airbag. When the airbag is used, the bag is inflated by the rapid introduction of the compressed air to provide an impact buffering function. The introduction of the compressed air causes a large inflation force to act on the bag. This is because the bag base fabric must have strength characteristics enough to withstand the inflation force, and if the strength of the multifilament yarn is less than 8.0 g / denier, the safety standard cannot be sufficiently satisfied. The more preferable yarn strength of the multifilament yarn used in the present invention is 9.0 g / denier or more.

In the present invention, it is extremely important that the cover factor (CF) determined by the following equation is 1,900 to 2, when the multifilament yarn satisfying the above requirements is woven using the warp yarn and the weft yarn. , 3
00, and the total fineness D (denier) of the warp and the weft and the W (mm) in their woven state must satisfy the relationship of the following formula. D / W of warp = 700 or less, D / W of weft = 850 or less CF = {[total fineness of warp (denier)] × warp density (book / inch) +） [total fineness of weft (denier)] × weft Density (book / inch)

That is, the cover factor is an index indicating the air permeability of the fiber in the woven state by the total fineness of the warp and the weft and their respective densities. As the gap between the yarns becomes smaller, the airtightness increases and the airtightness increases, but on the other hand, the flexibility as the fabric decreases and the weight increases, and conversely as the value decreases, the fabric becomes softer and lighter, Hermeticity decreases. Therefore, in order to secure sufficient airtightness (low air permeability) while securing appropriate flexibility, it is necessary to use appropriate CF.
It is necessary to determine the value, and the present inventors have confirmed that, when the CF value is in the range of 1,900 to 2,300, both of the above characteristics are obtained.

[0012] However, the above-mentioned properties as the base fabric for an airbag are not determined only by the above-mentioned CF value, but the present inventors have further studied and found that the total fineness D (denier) of the warp and the weft yarns. ) And width W
(Mm) (refer to FIG. 1 described later) and satisfying the relationship of the above expression were confirmed to be indispensable requirements in evaluating low air permeability as an airbag. That is, the above setting formula is
The value obtained by dividing the total fineness of the warp and the weft by the width of the warp and the weft in the woven state. How the single yarns constituting the warp and the weft spread in the width direction on the plane of the base fabric, The criterion as to whether the gap between the yarns is small is expressed. If the single yarn fineness is too large, or if a highly convergent yarn such as a twisted yarn is used as the warp yarn, the convergence of the whole yarn is increased and the D / D The value of W increases, and satisfactory low air permeability cannot be secured. However, when these values are not more than 700 for the D / W of the warp and not more than 850 for the D / W of the weft, it is always stable and excellent even without performing surface coating treatment or calendering after weaving. It was confirmed that air permeability was ensured.

That is, in the present invention, in order to secure the strength characteristics and flexibility of the airbag, the total fineness and single yarn fineness of the multifilament yarn are defined, and the CF value in the woven state, the warp and the weft are defined. D / W
By defining the values, it has been possible to secure a low air permeability and to provide a lightweight and inexpensive base fabric for an airbag.

[0014]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, and the present invention is not limited thereto. Of course, the present invention can be embodied with modifications, all of which are included in the technical scope of the present invention. The test methods for various performances employed in the following examples are as follows.

Weave density: Measured according to JIS L 1096 6.6 Air permeability: Measured according to JIS L 1096 6.27.1 A (Brazil type method) Bend softness: JIS L 1096 6.19.1 A (Cantilever type method) ) Measured according to JIS L 1096 6.4.2 Thickness: Measured according to JIS L 1096 6.5 Thread width W (mm): Scanning electron microscope for the surface photograph of the sample prepared according to JIS L 10963 (SEM) (see a partially enlarged plan view of FIG. 1), and the widest part based on the unit length in the photograph is W
₁ (mm), and a value obtained by dividing by the photographing magnification T (times) is defined as a thread width W (mm). W (mm) = W ₁ / T D / W of warp and weft: A value obtained by dividing the fineness (denier) of the warp and weft by the width W (mm) of the yarn obtained above.

Example 1 A plain fabric is woven using a 420d / 144f multifilament yarn of nylon 66 (strength: 9.6 g / d) as a warp yarn and a weft yarn without twisting, and scouring, drying and setting treatments are performed. To produce a woven fabric of 48 warps / inch, 48 wefts / inch, and a cover factor (CF) 1967. Table 1 below shows the physical properties of the obtained woven fabric, and FIG. 2 shows a scanning electron microscope (SEM) photograph of the surface. As is evident from Table 1, this woven fabric has extremely low air permeability, low rigidity and excellent flexibility, and is very excellent as an airbag base fabric. I understand.

Example 2 Weaving a plain woven fabric using a 315d / 108f multifilament yarn (strength: 9.6 g / d) made of nylon 66 as a warp and a weft without twisting, scouring, drying and setting treatment Was carried out to produce a woven fabric having a warp of 58 yarns / inch, a weft of 58 yarns / inch, and a cover factor (CF) of 2059. The physical properties of the obtained woven fabric are as shown in Table 1 below. This woven fabric has extremely low air permeability, low rigidity and excellent flexibility, and is extremely excellent as an airbag base fabric. It turns out that it is a thing.

Example 3 A plain fabric is woven by using a 210d / 72f multifilament yarn (strength: 9.6 g / d) made of nylon 66 as a warp and a weft while being untwisted.
The setting process is performed, and the warp 74 / inch, the weft 74
A book / inch, a cover factor (CF) 2145 fabric was produced. The physical properties of the obtained woven fabric are as shown in Table 1 below. This woven fabric has extremely low air permeability, low rigidity and excellent flexibility, and is extremely excellent as an airbag base fabric. It turns out that it is a thing.

Example 4 A plain fabric is woven by using a 140d / 72f multifilament yarn (strength: 9.6 g / d) made of nylon 66 as a warp and a weft while being untwisted.
The setting process is performed, and the warp 94 / inch, the weft 94
A book / inch, a cover factor (CF) 2224 woven fabric was produced. The physical properties of the obtained woven fabric are as shown in Table 1 below. This woven fabric has extremely low air permeability, low rigidity and excellent flexibility, and is extremely excellent as an airbag base fabric. It turns out that it is a thing.

Comparative Example 1 A plain woven fabric was woven using 420d / 72f multifilament yarn (strength: 9.6 g / d) made of nylon 66 in a non-twisted state as a warp yarn and a weft yarn.
The setting process is performed, and the warp yarn 54 / inch and the weft yarn 54
A book / inch woven fabric with a cover factor (CF) 2213 was produced. The physical properties of the obtained fabric are shown in Table 1 below, and a scanning electron microscope (SEM) photograph of the surface is shown in FIG. As is clear from Table 1, the air permeability of this woven fabric is very low, but the stiffness is large and the flexibility is inferior, and the weight per unit area is larger than that of the base fabric of Example 1. However, it was not preferable in terms of economy.

Comparative Example 2 A 315d / 108f multifilament yarn (strength: 9.6 g / d) made of nylon 66 was used, a warp yarn was used as a twisted product (s twist: 70 T / m), and a weft was used without twisting. A plain woven fabric was woven, refined, dried, and set to produce a woven fabric of 58 warps / inch, 58 wefts / inch, and a cover factor (CF) of 2059. The D / W of the warp in the obtained woven fabric is 716, and the D / W of the weft is 851.
Met. The physical properties of this woven fabric are as shown in Table 1 below. The woven fabric has a very high air permeability and is not practical for an airbag base fabric.

Comparative Example 3 Using a 315d / 72f multifilament yarn (strength: 9.6 g / d) made of nylon 66, weaving a plain fabric using untwisted warp and weft yarns, scouring, drying, The setting process was performed to produce a woven fabric of 64 warps / inch, 61 wefts / inch, and a cover factor (CF) 2219. The physical properties of the obtained woven fabric are as shown in Table 1 below, and although the air permeability is very low, the stiffness is large and the flexibility is inferior, and the fabric per unit area is smaller than that of the base fabric of Example 2. The weight was large, and it was not preferable in terms of economy.

[0023]

[Table 1]

[0024]

According to the present invention, the total fineness and single yarn fineness of the multifilament yarn constituting the base fabric and the original yarn strength are specified, and the cover factor (CF) in the woven state is specified. ) And the relationship between the total fineness D (denier) and the width W (mm) of the warp and weft yarns, thereby providing a lightweight and inexpensive base fabric for airbags that has both excellent air-blocking properties and flexibility. I can do it.

[Brief description of the drawings]

FIG. 1 is a partially enlarged plan view of a fabric constituting a base fabric for an airbag.

FIG. 2 is a scanning electron micrograph (× 60) showing a woven structure of an airbag base fabric obtained in an example.

FIG. 3 is a scanning electron micrograph (× 60) showing a woven structure of a base fabric for an airbag obtained in a comparative example.

Claims (1)

[Claims] 1. A non-coated airbag base fabric which is not subjected to a resin coating treatment and a calendering treatment, and has a total fineness of 140 to 450 denier and a single yarn fineness of 1 to 1.
A multifilament yarn having a denier of 4 g and a yarn strength of 8.0 g / denier or more is woven. The total fineness D (denier) of the warp and the weft, the width W (mm) of the warp and the weft in the woven state, and Cover factor (C
F) which satisfies the following relationship: D / W of warp = 700 or less D / W of weft = 850 or less CF = √ (total fineness of warp) × warp density + √ (total fineness of weft) × weft density = 1,900-2,300
[(Denier) ^1/2 book / inch]