JP3278968B2 - Method of manufacturing base fabric for airbag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a base fabric for an airbag which absorbs an impact of an occupant during a vehicle collision and protects the same.

[0002]

2. Description of the Related Art In recent years, the practical use of airbags for ensuring the safety of occupants in automobiles has been rapidly increasing. In the event of an automobile collision, the airbag activates a sensor in response to the impact of the collision, generating high-temperature, high-pressure gas, which causes the airbag to inflate instantaneously, It is intended to protect the forehead. Conventionally, a plain woven fabric using nylon 6 or nylon 6.6 filament yarn of 300 to 1000 denier for airbag, chloroprene, chlorosulfonated olefin,
It was made by cutting and laminating a base fabric that was coated with an elastomer resin such as synthetic rubber such as silicone, laminated, and sewn on a bag.

[0003] In addition to such a coated base fabric, non-coated base fabrics for airbags have also been studied. For example, Japanese Patent Application Laid-Open No. 1-122752 and Japanese Patent Application Laid-Open No. 3-13724.
No. 5 has been proposed.

[0004]

However, when the former elastomer resin is applied and laminated on one side of the base fabric, a coating method such as knife coating, roll coating, reverse coating, etc. is generally employed. Is usually applied to the surface of the base fabric at 40 to 100 g / m ² ,
It is rather heavy, has a rough texture, and may be scratched when the face comes into contact with the face when the airbag is inflated, which is not preferable. In addition, there is a problem that it is difficult to fold in terms of storage. Also, on the processing side, the coating process is complicated, and the cost is high.
Currently, there is a strong demand for non-coated airbags. In the latter method, which is a base fabric for a non-coated airbag, disclosed in Japanese Patent Application Laid-Open No. 1-122752, heat fixation by calendering is applied to obtain the most important air-blocking property, that is, low air permeability for the function of the airbag. Although there is no effect at a low temperature and an effect can be seen at a high temperature, there is a problem that the texture is hardened by fusion. Further, in the method disclosed in JP-A-3-137245, the heat-shrinkable yarn is utilized and heat-fixed by calendering or the like. There is a problem that the strength is reduced. On the other hand, from the weaving side, studies have been made to increase the density, but there is still a problem that sufficient low air permeability cannot be obtained and weaving defects such as warp streaks and thread breakage occur.

[0005] In view of the drawbacks of the conventional airbag fabric, the present invention has a soft feel while maintaining necessary properties such as mechanical properties, flame retardancy and air-blocking properties of the airbag. An object of the present invention is to provide a base fabric for an airbag having excellent storage properties.

[0006]

The present invention has the following configuration to achieve the above object.

That is, the method for producing a base fabric for an airbag of the present invention is characterized in that the fibers constituting the synthetic fiber fabric are swelled and filled.

[0008]

The present invention is based on a swelling treatment of a synthetic fiber fabric constituting an airbag base fabric.
Air barrier, which is the most important in the function of the airbag,
In other words, air that achieves extremely low air permeability and has excellent mechanical properties, flame retardancy, soft texture, and excellent storage properties without worrying about weaving defects associated with high density. It is an object of the present invention to provide a base fabric for a bag.

The synthetic fiber referred to in the present invention is nylon 6
6, Nylon 6, Nylon 12, Nylon 4.6, Nylon 6 and Nylon 6.6 copolymer, Polyamide fiber obtained by copolymerizing nylon with polyalkylene glycol, dicarboxylic acid, amines, etc., Polyalkylene terephthalate, and polyester Polyester fibers, acrylic fibers, and the like obtained by copolymerizing an aliphatic dicarboxylic acid such as isophthalic acid, 5-sodium sulfoisophthalic acid, or adipic acid as an acid component constituting the repeating unit (1) can be used. As a cloth made of such fibers, a woven fabric, a knitted fabric and a nonwoven fabric can be used,
In particular, a thin plain weave structure is preferably used.

[0010] Such fibers are usually used for improving productivity or characteristics in the production and processing steps of the raw yarn, such as heat stability, antioxidant, light stabilizer, and smoothness. Various additives such as an agent, an antistatic agent, a plasticizer, a thickener, a pigment, and a flame retardant may be contained.

The strength of the single fibers constituting the fabric is not particularly limited, but is preferably 6 g / d, more preferably 7 g / d or more. The fineness and total fineness of the single fibers constituting the fabric are not particularly limited as long as they satisfy the mechanical properties required as an airbag,
Preferably, the single yarn fineness is about 3 to 7 denier, and the total fineness is about 200 to 1000 denier.

As the swelling treatment referred to in the present invention, there can be employed two kinds of methods, a treatment with an organic solvent having a performance of swelling synthetic fibers and a treatment with wet heat.

[0013] As swellable organic solvent in the present invention, with respect to the polyamide fiber fabric, Ben di alcohol, phenylethyl alcohol, phenol, o- cresol, m- cresol, p- cresol, tolyl alcohol Yes, and for polyester fiber fabrics, methylenechlorobenzene, trichlorobenzene, phenylphenol, methylnaphthalene, chloroform, dichloroethane, trichloroethane, dichloroethylene, dimethylformamide and the like can be used. Among these, benzyl alcohol and phenylethyl alcohol are preferably used in the case of polyamide fibers, and methylene chloride is preferably used in the case of polyester fibers, from the viewpoints of swelling property and handleability.

In the treatment with these swellable organic solvents, there are a method of immersing in a treatment liquid, a method of squeezing and leaving with a mangle after immersion, and a method of immersing and heating. Also, such processing is
It can be applied after scouring or intermediate setting. Incidentally, Ben di alcohol of the polyamide fiber fabric, when treated with phenyl ethyl alcohol, the concentration of the treating solution, the emulsified dispersion using a surfactant so that the 1% to 50% Is preferred.

As the wet heat treatment, treatment with heated steam or hot water at 100 ° C. or higher is used, and it is particularly effective for polyamide fiber cloth.

After the swelling treatment, a chemical softening treatment with a softening agent or the like, a mechanical softening treatment such as a cam fitting treatment, or a pressure and compression treatment may be applied.

In the present invention, the degree of clogging of the fabric after the swelling treatment can be determined by a cover factor.
For example, if the cover factor is 2000 to 2500, it is preferably used as the airbag base fabric of the present invention.

In order to determine this from another viewpoint, it can be determined by the air permeability of the outer skin fabric. That is, as the base fabric for an airbag of the present invention, one having an air permeability of 0.5 cc / cm ² / sec or less is preferably used, and more preferably an air permeability of 0.3 cc / cm ² / sec or less. It is preferable to have

The fabric cover factor referred to here is:
The product of the square root of the yarn denier and the number of yarns per inch is obtained by the process and weft, and the sum of these values is referred to.

[0020]

Next, the present invention will be described in more detail by way of examples.

The lightness, air-blocking property, flexibility, and storability of the airbag in the examples are as follows.
The bending resistance and foldability were measured by the following methods.

(Mass) The mass was determined based on the mass measurement method of JIS K6328. (Airflow) The airflow was determined based on the method A of JISL1096. (Bending resistance) The bending resistance (mm) was determined based on the 45 ° cantilever method of JISL1096. The coated product was measured with the rubber side up. (Foldability) A 3 cm × 15 cm base fabric is folded in three, and the bulk when a load of 7.5 g is applied is measured and compared. That is, a standard product prepared by applying 45 g / m ² of silicone rubber to nylon 66 was prepared, and the relative value when the bulkiness of this standard product was set to 100 was shown.

Example 1 A plain woven fabric having a total factor of 420 denier, 72 filaments, strength of 8.3 g / d nylon 6.6 fibers, and a warp and weft of 46 yarns / inch and a cover factor of 1885 was used. Then, after scouring and drying by a conventional method, it was set at 180 ° C. in the middle. Next, the plain fabric is immersed in a 25 ° C. emulsified dispersion composed of 3% of benzyl alcohol and 0.3% of Sunmol BK-20 (manufactured by Nika Chemical Co., Ltd.), heated to 80 ° C. in 20 minutes, and 20 minutes. The immersion heat treatment was performed. Thereafter, it was sufficiently washed with water and dried at 100 ° C. Its cover factor was 2172.

Table 1 shows the evaluation results of the airbag fabric thus obtained. The airbag fabric of the present invention was lightweight, excellent in non-breathability, and excellent in foldability, that is, excellent in storage.

Comparative Examples 1 to 4 Plain woven fabric using a nylon 6.6 fiber having a total fineness of 420 denier, 72 filaments and a strength of 8.3 g / d, and having a warp and weft of 46 yarns / inch and a cover factor of 1885. After weaving, scouring and drying by a conventional method, the mixture was intermediately set at 180 ° C. to obtain an airbag base fabric. Its cover factor was 1967 [Comparative Example 1].

A plain woven fabric having the same nylon 6.6 fiber and a cover factor of 1885 with a warp and weft of 46 yarns / inch and a cover factor of 1885 is used. I set it. Then
This plain fabric was heated to 130 ° C. and 180 ° C., and one side was press-compressed at a linear pressure of 45 kg / cm between a metal roll having a flat surface and a room-temperature metal roll to obtain a base fabric for an airbag. The cover factors for this are 1967
[Comparative Example 2] and 2008 [Comparative Example 3].

On the other hand, the same nylon 6.6 fiber is used to weave a plain woven fabric having a cover factor of 1885, which has a warp and weft of 46 yarns / inch, and is scoured and dried by a conventional method. Intermediate set. Then
This plain fabric is coated with a silicone rubber having a coating viscosity of 2800.
0 cps coating solution, with a comma coater, the coating amount is 45
g / m ² , dried at 130 ° C., and vulcanized at 180 ° C. for 3 minutes to obtain a base fabric for a silicone rubber-coated airbag. Its cover factor was 1967. [Comparative Example 4].

The airbag base fabric thus obtained was evaluated in the same manner as in Example 1. As can be seen from Table 1, the airbag base fabric of Comparative Example 1 did not provide the low air permeability required of the airbag, and the pressurized and compressed airbag base fabric of Comparative Example 2 was: The airbag fabric of Comparative Example 3 had a low calendering effect and insufficient low air permeability, and the airbag base fabric of Comparative Example 3 had good low air permeability, but had a rough and hard feel, was poor in foldability, and had a problem in terms of storability. was there. On the other hand, the airbag base fabric coated with the silicone rubber of Comparative Example 4 was excellent in terms of non-breathability, but was insufficient in storability and had some problems in terms of lightness.

Example 2 Nylon 6 fibers having a total fineness of 420 denier, 136 filaments and a strength of 8.5 g / d were used, and the warp and weft yarns had a cover factor of 48 / inch.
967 plain woven fabric was woven, scoured and dried by a conventional method.
Then, the plain fabric was phenylethyl alcohol 20
%, And 2% of Sunmol BK-20 (manufactured by Nichika Chemical Co., Ltd.) at 25 ° C. for 15 minutes. Thereafter, the resultant was washed with hot water at 80 ° C., dried at 120 ° C., and then set at 180 ° C. in the middle. Its cover factor is 221
It was 3.

Table 1 shows the evaluation results of the airbag fabric thus obtained. The airbag fabric of the present invention was lightweight, excellent in non-breathability, and excellent in foldability, that is, excellent in storage.

Comparative Examples 5 and 6 Nylon 6 fibers having a total fineness of 420 denier, 136 filaments and a strength of 8.5 g / d were used, and the warp and weft yarns had a cover factor of 48 / inch.
967 plain woven fabric was woven, scoured and dried by a conventional method, and then set at 180 ° C. in the middle. Next, the plain fabric was repeatedly coated three times with a coating liquid of chloroprene rubber having a coating viscosity of 31000 cps with a comma coater so that the coating amount was 95 g / m ² . After a while
Vulcanization treatment was performed at 180 ° C. for 3 minutes to obtain a chloroprene rubber-coated base fabric for an airbag. Its cover factor was 2008 [Comparative Example 5].

A plain woven fabric having the same nylon 6 fiber and a cover factor of 2213 for both the warp and the weft is 54 yarns / inch, is scoured and dried by a conventional method, and is set at 180 ° C. in the middle. Thus, an airbag base fabric was obtained. Its cover factor was 2254 [Comparative Example 6].

The airbag fabric thus obtained was evaluated in the same manner as in Example 1. As can be seen from Table 1, the chloroprene rubber-coated airbag base fabric of Comparative Example 5 was excellent in terms of non-breathability, but had a rough feel, was poor in foldability, and had a problem in terms of storability. there were. On the other hand, the base fabric for an airbag of Comparative Example 6 had high density at the weaving stage only, and thus had weaving defects such as warp and thread breakage.

Example 3 Polyester fibers having a total fineness of 420 denier, 144 filaments and a strength of 8.6 g / d were used, and the warp and the weft had a cover factor of 47 / inch.
926 was woven, scoured and dried by a conventional method, and then set at 180 ° C. in the middle. Next, the plain fabric was immersed in methylene chloride at 25 ° C. for 15 minutes. Thereafter, it was sufficiently dried at room temperature. Its cover factor was 2213.

Table 1 shows the evaluation results of the airbag fabric thus obtained. The airbag fabric of the present invention was lightweight, excellent in non-breathability, and excellent in foldability, that is, excellent in storage.

Comparative Examples 7 to 9 Using a polyester fiber having a total fineness of 420 denier, 144 filaments and a strength of 8.6 g / d, weaving a plain weave having a cover factor of 1926 with a warp and weft of 47 yarns / inch. After scouring and drying according to a conventional method, intermediate setting was performed at 180 ° C. to obtain a base fabric for an airbag. Its cover factor was 1967 [Comparative Example 7].

Further, using the same polyester fiber,
The warp and the weft are made of a plain woven fabric with a cover factor of 1926, which is 47 yarns / inch.
After drying, it was set at 180 ° C. in the middle. Then, the plain fabric was heated to 185 ° C., and one side was press-compressed at a linear pressure of 50 kg / cm between a metal roll having a flat surface and a normal-temperature metal roll to obtain a base fabric for an airbag. Its cover factor was 1967 [Comparative Example 8].

Further, using the same polyester fiber,
The warp and the weft are made of a plain woven fabric with a cover factor of 1926, which is 47 yarns / inch.
After drying, it was set at 180 ° C. in the middle. Next, this plain fabric was coated with a silicone rubber having a coating viscosity of 30,000 c.
The coating amount is 45 g with a comma coater
/ M ² and dried at 130 ° C.
Vulcanization treatment was performed at 180 ° C. for 3 minutes to obtain a base fabric for a silicone rubber-coated airbag. Its cover factor was 1967. [Comparative Example 9].

The airbag fabric thus obtained was evaluated in the same manner as in Example 1. As can be seen from Table 1, the airbag base fabric of Comparative Example 7 has insufficient low air permeability, which is a necessary property of the airbag, and the pressurized and compressed airbag base fabric of Comparative Example 8 has a texture. However, there was a problem in that it was coarse and hard, and was inferior in foldability and could be stored. On the other hand, Comparative Example 9
In the airbag fabric of the above, sufficient non-breathability was not obtained.

Example 4 Polyester fibers having a total fineness of 500 denier, 144 filaments and a strength of 8.6 g / d were used, and a plain woven fabric having a cover factor of 1967 and a warp and weft of 44 yarns / inch was woven. Scoured by the method. Next, the plain fabric was immersed in methylene chloride at 25 ° C. for 15 minutes. Then, after drying sufficiently at room temperature, the intermediate setting was performed. Its cover factor is 2236
Met. Table 1 shows the evaluation results of the airbag fabric thus obtained. The airbag fabric of the present invention was lightweight, excellent in non-breathability, and excellent in foldability, that is, excellent in storage.

Comparative Example 10 A plain woven fabric having a total fineness of 500 denier, 144 filaments, strength of 8.6 g / d, and a warp and weft of 50 / inch and a cover factor of 2236 was used. After scouring and drying according to the method, intermediate setting was performed at 180 ° C. to obtain a base fabric for an airbag. Its cover factor was 2281.

Table 1 shows the evaluation results of the airbag fabric thus obtained. The airbag fabric of Comparative Example 10 had high density at the weaving stage only, and thus had weaving defects such as warp and thread breakage.

Example 5 A nylon 66 fiber having a total fineness of 315 denier, 72 filaments and a strength of 8.3 g / d was used, and both the warp and the weft had a cover factor of 55 / inch.
952 plain weaves were woven and scoured in a conventional manner. Then
This plain fabric was subjected to a wet heat treatment with heated steam at 105 ° C. for 3 minutes. Thereafter, it was dried at 120 ° C. and set at 180 ° C. Its cover factor was 2165. Table 1 shows the evaluation results of the airbag fabric thus obtained. The airbag base fabric of the present invention includes:
It was lightweight, excellent in non-breathability, and excellent in storage.

Comparative Example 11 The same nylon 66 fiber as that of Example 5 was used, and the warp and the weft were 55 yarns / inch and the cover factor was 1
952 plain weaves were woven and scoured in a conventional manner. Thereafter, the intermediate setting was performed at 180 ° C. without performing the wet heat treatment. Its cover factor was 1988.

Table 1 shows the evaluation results of the airbag fabric thus obtained. The airbag fabric of Comparative Example 11 was inferior in terms of non-breathability.

[0046]

[Table 1]

[0047]

The airbag obtained by the present invention has the following effects.

(1) The airbag fabric of the present invention has excellent non-breathability. In addition, since it is lightweight, has a soft texture, and is excellent in foldability, it can be easily stored in a steering wheel or an instrument panel.

(2) The mechanical properties of the airbag are not impaired at all.

(3) No weaving defects such as warp and thread breakage, and excellent weaving properties.

(4) Since no elastomer resin is used,
It is advantageous in workability and cost. According to the present invention,
Thus, an extremely safe and highly reliable airbag can be provided.

Continuation of the front page (56) References JP-A-61-34276 (JP, A) JP-A-1-201582 (JP, A) JP-A-1-1222752 (JP, A) (58) Fields studied (Int .Cl. ⁷ , DB name) D06M 13/00-15/715

Claims (9)

(57) [Claims] 1. A method for producing a base fabric for an airbag, comprising swelling and clogging fibers constituting a synthetic fiber cloth. 2. The method for producing a base fabric for an airbag according to claim 1, wherein the swelling treatment is performed with a swelling organic solvent or moist heat. 3. The method according to claim 1, wherein the synthetic fibers are polyamide fibers. 4. The method according to claim 1, wherein the synthetic fibers are polyester fibers. 5. The swellable organic solvent is at least one kind of claim 2 method for producing a base fabric for an air bag according selected from Ben di- alcohol or phenylethyl alcohol. 6. The method according to claim 5, wherein the swellable organic solvent is a 1-50% emulsified dispersion. 7. The method according to claim 5 , wherein the swellable organic solvent is methylene chloride. 8. The method for producing a base fabric for an airbag according to claim 1, wherein a cover factor of the fabric after the swelling treatment is 2,000 or more. 9. The air permeability of the cloth after swelling treatment is 0.5 cc.
The method for producing a base fabric for an airbag according to any one of claims 1 to 8, which is not more than / cm ² / sec.