JP4032412B2 - Airbag base fabric - Google Patents

Description

【００４４】
【発明の効果】
本発明によれば、軽量で低通気性能を有し、かつ柔軟性の良いエアバッグ用基布を提供することができる。
【図面の簡単な説明】
【図１】荷重下の二つ折りの基布の折り目部の厚さの測定方法を示す。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an airbag base fabric having low air permeability at low cost while maintaining necessary mechanical characteristics.
[0002]
[Prior art]
In recent years, airbags, which have been rapidly installed as one of the safety parts of automobiles, detect high-pressure, high-pressure gas from the inflator when a car crash occurs. When the airbag is suddenly deployed and the body of the driver or passengers jumps out in the colliding direction, the head particularly prevents and protects the head from colliding with the handle, the windshield, the door glass and the like.
[0003]
Conventionally, coated base fabrics coated with synthetic rubber such as chloroprene, chlorosulfonated olefin, and silicone have been used for airbags because of their high heat resistance, air barrier properties (low air permeability), and high flame resistance. .
[0004]
However, these coated base fabrics have many problems in using as a base fabric for an air bag because the weight of the base fabric increases, the flexibility is not satisfactory and the manufacturing cost is high.
[0005]
On the other hand, in view of the above-mentioned problems of the coated base fabric, a non-coated airbag base fabric is also manufactured. Such a non-coated base fabric is lighter and has better storage properties than a coated base fabric. However, in order to improve the safety at the time of collision accompanying the diversification of drivers such as women and elderly people while maintaining the storage capacity for securing the interior space of the car, the initial restraint is improved when the passenger airbag is deployed, There is a need for an air bag base fabric having lower ventilation performance.
[0006]
Therefore, recently, the fabric was impregnated with a synthetic resin diluent as a base fabric for an air bag having flame retardancy and lower air permeability while maintaining the lightness and good storage characteristics that are the characteristics of the non-coated base fabric. An air bag base fabric has been proposed. For example, Japanese Patent Application Laid-Open No. 11-222776 discloses an airbag base fabric in which a fabric is treated with a water-based treatment agent in which a specific polyester resin and a low-volatile softening agent are dispersed in water. However, in the case of a base fabric manufactured by such a manufacturing method, in order to achieve low air permeability, the amount of resin to be attached to the fabric has to be increased, which increases the weight of the base fabric and lowers flexibility. There was a point.
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide an air bag base fabric that is lightweight, has low ventilation performance, and has good flexibility.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to solve such problems, the present inventor finally came up with the present invention. That is, according to the present invention, in an airbag base fabric manufactured by impregnating a fabric made of synthetic fibers with a water-based synthetic resin, the air permeability of the base fabric is 1.0 l / cm ² / min or less under a pressure of 100 kPa. The thickness of the base fabric is 0.28 mm or less and the thickness of the double-layer base fabric is folded in half to apply a load of 2.35 N / cm ² In this case, the airbag fabric is characterized in that the thickness ratio of the folds of the fabric is 1.5 or less.
[0009]
In a preferred embodiment of the airbag fabric of the present invention, the water-based synthetic resin is an acrylic resin, and the amount of the water-based synthetic resin attached to the base fabric is 0.5 to 20 g / m ² .
[0010]
In a more preferred embodiment of the airbag fabric of the present invention, the cover factor K of the fabric is 2000 or more.
[0011]
In another preferred embodiment of the airbag fabric of the present invention, the synthetic fiber has a boiling water shrinkage of 5 to 15%, a total fineness of 100 to 500 dtex, and a single yarn fineness of 6 dtex or less.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The synthetic fiber used for the airbag fabric of the present invention is not particularly limited as a raw material, but is particularly an aliphatic polyamide fiber such as nylon 66, nylon 6, nylon 46, nylon 12, or aramid fiber. Aromatic polyamide fibers, polyester fibers such as polyethylene terephthalate and polybutylene terephthalate can be used. Other materials that can be used include wholly aromatic polyester fibers, ultrahigh molecular weight polyethylene fibers, PPS fibers, polyetherketone fibers, and the like. However, polyester fiber and polyamide fiber are particularly preferable in consideration of economy. Further, these fibers may be obtained from raw materials that are partially or wholly reused. Further, these synthetic fibers have no problem even if they contain various additives in order to improve process passability in the raw yarn manufacturing process and post-processing process. For example, an antioxidant, a heat stabilizer, a smoothing agent, an antistatic agent, a thickener, a flame retardant, and the like can be contained. Moreover, there is no problem even if this synthetic fiber is dyed after original yarn or after yarn production. Further, the cross section of the single yarn may be an irregular cross section in addition to a normal round cross section.
[0013]
The total fineness and single yarn fineness of the synthetic yarn used for the airbag fabric of the present invention is preferably 100 to 500 dtex and the single yarn fineness is preferably 6 dtex or less. More preferably, the total fineness is 120 to 480 dtex, and the single yarn fineness is 4 dtex or less. That is, when the total fineness is less than the above lower limit, the tensile strength and tear strength may be insufficient. If the upper limit is exceeded, there is no problem in strength, but the flexibility of the fabric is impaired, and the storage property and the surface of the fabric become hard, which is disadvantageous because it may damage the human skin at the time of collision. When the single yarn fineness exceeds the above upper limit, the flexibility of the woven fabric is impaired, which is disadvantageous from the viewpoint of storage properties and influence on the human body.
[0014]
In addition, the synthetic fiber used for the airbag fabric of the present invention preferably has a boiling water shrinkage of 5 to 15%. A more preferable value of the boiling water shrinkage is 7 to 13%. If the boiling water shrinkage rate is smaller than the lower limit value, a low air permeability may not be obtained after the shrinking process described later. If the boiling water shrinkage rate is larger than the upper limit value, the thickness of the fabric after the shrinking process may be increased and the compactness may be impaired. .
[0015]
The weaving method of the fabric used for the airbag fabric of the present invention is not particularly limited, but plain weaving is preferable in consideration of the uniformity of the physical properties of the fabric. The warp and weft yarns to be used need not be single. For example, the thickness, the number of yarns, and the types of fibers may be different. The loom is not particularly limited, such as an air jet loom, a rapier room, or a water jet loom.
[0016]
The woven fabric can be shrunk as necessary. The heat treatment temperature of the fabric for shrinkage processing is not particularly specified, and is usually 100 to 200 ° C. A treatment at 160 ° C. or lower is preferable in terms of obtaining low air permeability. The treatment is not particularly limited, such as a heat setter or a boiling water bath, but a processing machine capable of about 2 to 15% overfeed in the warp direction of the fabric may be used.
[0017]
Further, the cover factor of the woven fabric is preferably 2000 or more. If it is less than 2000, the amount of resin for achieving low air permeability increases, so the flexibility is lowered, which is not preferable.
[0018]
The fabric thus woven is then impregnated with a resin diluent containing an aqueous synthetic resin. The water-based synthetic resin used in the impregnation treatment of the airbag fabric of the present invention is preferably an acrylic resin from the viewpoint of storage properties. The concentration of the water-based synthetic resin in the resin diluent is not particularly limited, but is usually 1.0 to 30.00% by weight in solid content.
[0019]
The water-based resin used in the present invention may be either water-soluble or water-dispersible, but it is important that it does not contain an organic solvent for the purpose of improving the solubility and / or dispersibility of the resin component. These water-based synthetic resins may be used in admixture with additives such as a deterioration inhibitor, a crosslinking agent, an inorganic filler, and a colorant as long as the target performance is not affected.
[0020]
After the impregnation treatment, the base fabric is dried. Although this drying temperature is not specifically limited, Usually, it is 50-200 degreeC, Preferably it is 100-150 degreeC. Adhesion amount of the aqueous synthetic resin to the base fabric after drying is preferably from 0.5 to 20 g / ^{m 2,} further preferably 1 to 15 g / ^{m 2.} When the adhesion amount of the water-based synthetic resin is less than the above lower limit value, there is a possibility that sufficient low air permeability cannot be achieved. Moreover, when exceeding the said upper limit, a base fabric may become hard and a softness | flexibility may be impaired.
[0021]
Next, the performance of the airbag fabric of the present invention manufactured as described above will be described.
[0022]
The air bag base fabric of the present invention has a low air permeability of 1.0 l / cm ² / min or less under a pressure of 100 kPa in terms of air permeability. When the air permeability exceeds 1.0 l / cm ² / min, the initial restraint property at the time of airbag deployment is inferior, and there is a possibility that safety at the time of collision is lacking.
[0023]
Moreover, the thickness of the base fabric for airbags of this invention is 0.28 mm or less. If the thickness exceeds 0.28 mm, the weight of the base fabric increases and the flexibility may be lacking.
[0024]
Furthermore, the airbag base fabric of the present invention is obtained when the load of 2.35 N / cm ² is applied by folding one base fabric in half with respect to the thickness of the two-layer base fabric in terms of storability. The ratio of the thickness of the fold portion of the base fabric is 1.5 or less.
[0025]
Since the airbag is folded into a predetermined shape and mounted on the automobile in a state of being stored in a certain size package, the workability in storage and the thickness of the bag after storage are important. When the airbag is folded, the thickness of the fold portion is the largest, so the thickness of the fold portion greatly affects the thickness of the bag. Therefore, the present inventor has adopted the following storability test as a storability evaluation method according to the actual usage of the airbag.
[0026]
Storability test: When one airbag base fabric is folded in two in the bias direction without applying pressure, and a load of 2.35 N / cm ² is applied to the fold portion over 10 mm from the end of the fold portion. Measure the maximum thickness of the crease. The measuring method is shown in FIG. Divide this measured value by the thickness of the two layers of base fabric to calculate the ratio.
[0027]
Here, the load of 2.35 N / cm ² corresponds to a load required when the airbag is stored in the storage container. In the airbag fabric of the present invention, the ratio is 1.5 or less, preferably 1.3 or less. If the ratio is larger than 1.5, the storage workability may be deteriorated. Moreover, even if the ratio is 1.5 or less, if the thickness of the base fabric is thicker than 0.28 mm, the airbag itself becomes thick and the storage property may be deteriorated.
[0028]
As described above, since the airbag base fabric of the present invention is configured as described above, it is possible to obtain an airbag base fabric that is lightweight, has low air permeability, and has good flexibility.
[0029]
【Example】
Next, the present invention will be described in more detail with reference to examples. Various evaluations in the examples were performed according to the following methods.
[0030]
Air permeability: The air permeability was measured under a pressure of 100 kPa using a high pressure air permeability measuring machine (OEM System Co., Ltd.).
[0031]
Thickness: The thickness was measured according to JIS L1096 (6.5 method).
[0032]
Storability test: When one airbag base fabric is folded in two in the bias direction without applying pressure, and a load of 2.35 N / cm ² is applied to the fold portion over 10 mm from the end of the fold portion. The maximum value of the thickness of the crease part was measured. The measuring method is shown in FIG. The measured value was divided by the thickness of the double-layered base fabric to calculate the ratio.
[0033]
Example 1
Nylon 66 yarn with a total fineness of 350 dtex, 144 filaments and a boiling water shrinkage of 8.9% is woven in a plain jet weave in a water jet loom, shrunk with boiling water, dried at 110 ° C, and dried. A 59 / inch woven fabric with a weft density of 59 / inch was obtained. This woven fabric was impregnated with an aqueous synthetic resin diluted solution prepared by adjusting an aqueous acrylic resin (Ultrazol B-760 manufactured by Gantz Kasei Co., Ltd.) to a solid content concentration of 18%, and the resin amount after drying was adjusted to 9 g / m ² . The obtained base fabric was obtained. The properties of this base fabric were evaluated and are shown in Table 1.
[0034]
As is clear from Table 1, the air permeability under a pressure of 100 kPa was 1.0 l / cm ² / min or less, and the thickness and the storage property test were also satisfied.
[0035]
Example 2
Nylon 66 yarn with a total fineness of 350 dtex, 144 filaments and a boiling water shrinkage of 8.9% is woven in a plain jet weave in a water jet loom, shrunk with boiling water, dried at 110 ° C, and dried. A woven fabric having 55 pieces / inch and a weft density of 55 pieces / inch was obtained. This woven fabric was impregnated with an aqueous synthetic resin diluted solution prepared by adjusting an aqueous acrylic resin (Ultrazol B-760 manufactured by Ganz Kasei Co., Ltd.) to a solid content concentration of 18%, and the resin amount after drying was adjusted to 10 g / m ² . The obtained base fabric was obtained. The properties of this base fabric were evaluated and are shown in Table 1.
[0036]
As is clear from Table 1, the air permeability under a pressure of 100 kPa was 1.0 l / cm ² / min or less, and the thickness and the storage property test were also satisfied.
[0037]
Comparative Example 1
Nylon 66 yarn with a total fineness of 350 dtex, 144 filaments and a boiling water shrinkage of 8.9% is woven in a plain jet weave in a water jet loom, shrunk with boiling water, dried at 110 ° C, and dried. A 59 / inch woven fabric with a weft density of 59 / inch was obtained. This woven fabric was impregnated with an aqueous synthetic resin diluted solution prepared by adjusting an aqueous polyurethane resin (HYDRAN-HW950, manufactured by Dainippon Ink Co., Ltd.) to a solid content concentration of 10%, and the resin amount after drying was adjusted to 8 g / m ² . A base fabric was obtained. The properties of this base fabric were evaluated and are shown in Table 1.
[0038]
As is clear from Table 1, the air permeability under a pressure of 100 kPa is 1.0 l / cm ² / min or less, and sufficiently satisfies the low air permeability as an airbag base fabric. However, from the storage test, it was found that the fold portion was thick and the storage workability was poor.
[0039]
Comparative Example 2
Nylon 66 yarn with a total fineness of 350 dtex, 144 filaments and a boiling water shrinkage of 8.9% is woven in a plain jet weave in a water jet loom, shrunk with boiling water, dried at 110 ° C, and dried. A woven fabric having 55 pieces / inch and a weft density of 55 pieces / inch was obtained. This woven fabric was impregnated with a water-based synthetic resin diluted solution prepared by adjusting a water-based acrylic resin (Ultrazol B-760 manufactured by Ganz Kasei Co., Ltd.) to a solid content concentration of 0.1%, and the amount of resin after drying was 0.1 g. A base fabric having a thickness of / m ² was obtained. The properties of this base fabric were evaluated and are shown in Table 1.
[0040]
As is apparent from Table 1, the storage test is satisfactory, but the air permeability under a pressure of 100 kPa is much higher than 1.0 l / cm ² / min. It could not be said that the air permeability was sufficiently satisfied.
[0041]
Comparative Example 3
Nylon 66 yarn with a total fineness of 350 dtex, 144 filaments and a boiling water shrinkage of 8.9% is woven in a plain jet weave in a water jet loom, shrunk with boiling water, dried at 110 ° C, and dried. The woven fabric was 59 pieces / inch and a weft density of 59 pieces / inch. The properties of this base fabric were evaluated and are shown in Table 1.
[0042]
As is clear from Table 1, the storage property test is satisfactory, but the air permeability under a pressure of 100 kPa is much higher than 1.0 l / cm ² / min. I was not satisfied enough.
[0043]
[Table 1]

[0044]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the base fabric for airbags which is lightweight, has low ventilation performance, and has a favorable softness | flexibility can be provided.
[Brief description of the drawings]
FIG. 1 shows a method of measuring the thickness of a fold portion of a double-folded base fabric under load.

Claims (5)

In an airbag base fabric manufactured by impregnating a fabric made of synthetic fiber with an aqueous synthetic resin (but not calendering) , the synthetic fiber is made of nylon 66, and the air permeability of the base fabric is It is 1.0 l / cm ² / min or less under a pressure of 100 kPa, the thickness of the base fabric is 0.28 mm or less, and one base fabric is folded in half with respect to the thickness of the two-layer base fabric. When the load of 2.35 N / cm ² is applied, the ratio of the thickness of the crease part of the base fabric is 1.5 or less, and the adhesion amount of the water-based synthetic resin to the base fabric is 9 to 20 g / m. ² and a total fineness of the synthetic fiber is 100 to 350 dtex.   2. The airbag fabric according to claim 1, wherein the water-based synthetic resin is an acrylic resin. The airbag base fabric according to claim 1 or 2, wherein a cover factor K of the airbag base fabric calculated by the following formula is 2000 or more:
^{_{K = N W × D W 0.5}} + N F × D F 0.5
(However, N _W : Warp density (main / inch), D _W : Total warp fineness (dtex), N _F : Weft density (main / inch), D _F : Total weft fineness (dtex)).   The base fabric for an airbag according to any one of claims 1 to 3, wherein the boiling rate of the synthetic fiber is 5 to 15%.   The base fabric for an air bag according to any one of claims 1 to 4, wherein the single yarn fineness is 6 dtex or less.

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