JPH06146132A - Base material for non-coat air-bag - Google Patents

Abstract

PURPOSE:To obtain the subject base material having softness and excellent housing property while keeping the properties necessary for an air-bag such as mechanical properties, heat-resistance and air-shielding property without coating with a heat-resistant resin by crosslinking the base material itself composed of a base cloth or film. CONSTITUTION:A base material for non-coat air-bag having excellent melt- resistance, light-weight and flexibility and capable of reducing the shock to the human body caused by the expansion of the air bag is produced by using a woven fabric composed of polyamide fiber and produced by pressing a plain weave fabric having an air-transmission rate of <=0.5cc/cm<2>/sec and a cover factor of 1,500-3,000 or a film composed of polyester, polyamide, etc., and irradiating the fabric or film with electron ray to form a crosslinked structure accounting for 30-95% of the weight of the base material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag for absorbing and protecting an occupant's impact in the event of a vehicle collision, and more particularly to a non-coated airbag excellent in melting resistance.

[0002]

2. Description of the Related Art In recent years, the practical use of airbags for ensuring the safety of passengers in automobiles has been rapidly increasing. In the case of a collision accident of a car, the sensor operates in response to the impact of the collision, and high temperature and high pressure gas is generated, which causes the airbag to inflate momentarily and the passenger's face at the time of collision, 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 is used for an airbag, and chloroprene, chlorosulfonated olefin, and chloroprene are used for improving heat resistance, flame retardancy and air barrier property. Apply elastomer resin such as synthetic rubber such as silicone,
It was made by cutting the laminated base fabric and sewing it into a bag.

However, when these elastomer resins are applied and laminated on one side of a base cloth, a coating method such as knife coating, roll coating, reverse coating is generally adopted. With respect to the base cloth, in the case of a chloroprene elastomer resin, it is usually 90 to 120 on the surface of the base cloth.
It was applied at g / m ² , was rather heavy, had a rough texture, and was not preferable because it could be scratched when the face came into contact when the airbag was inflated. In addition, there is a problem that it is difficult to fold in terms of storability.
On the other hand, compared with the chloroprene elastomer resin, in the case of the silicone elastomer resin having more excellent heat resistance and cold resistance, the coating amount is 40 to 60 g / m ² and the weight is reduced,
Although it has improved considerably in terms of texture and storability, it is still not enough.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is, in view of the drawbacks of the conventional airbags, the texture while maintaining necessary characteristics such as mechanical characteristics, heat resistance and air barrier property as the airbag. It is intended to provide a non-coated airbag that is soft and has excellent storability.

[0005]

In order to achieve the above object, the present invention has the following constitution.

That is, the airbag base material of the present invention is characterized by being a non-coated airbag base material in which a base cloth or a film is cross-linked.

[0007]

The present invention is characterized in that it is constructed by crosslinking the airbag base material itself, that is, the base cloth or the film itself. When such a specific base material is adopted, it is not necessary to coat with a heat resistant elastomer resin, and the necessary characteristics such as mechanical characteristics, heat resistance and air barrier property as an air bag are maintained and the texture is good. It has been clarified that it is possible to provide an air bag that is soft and has excellent storability.

The base cloth referred to in the present invention means nylon 6.6,
Nylon 6, Nylon 12, Nylon 4.6, Nylon 6 and Nylon 6.6 copolymers, Polyalkylene glycol, polyamide fibers obtained by copolymerizing nylon with dicarboxylic acids and amines, homopolyesters such as polyethylene terephthalate, polyester Typical examples include polyester fibers obtained by copolymerizing the acid component that constitutes the repeating unit with an aliphatic dicarboxylic acid such as isophthalic acid, 5-sodium sulfoisophthalic acid or adipic acid, and copolymerization with paraphenylene terephthalamide and aromatic ether. Aramid fiber, rayon fiber, ultra-high molecular weight polyethylene fiber, paraphenylene sulfone, polysulfone and other sulfone-based fibers, polyetherketone fiber, carbon fiber, glass fiber, etc. But are not limited to, plain weave fabric from the land Susuki surface is preferable. Among these fibers, a plain woven fabric made of polyamide fiber has excellent airbag characteristics.

Such fibers may contain various additives which are usually used for improving the productivity or the characteristics in the manufacturing process and the processing process of the raw yarn. For example, heat stability, antioxidant, light stabilizer, leveling agent, antistatic agent,
It may contain a plasticizer, a thickener, a pigment, a flame retardant, and the like.

The strength of the single fibers constituting the woven 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 woven fabric are not particularly limited as long as they satisfy the required mechanical properties as an airbag, but the single yarn fineness is preferably 3 to 7d, and the total fineness is preferably Is preferably 200 to 1000D.

Further, in such a woven fabric, a woven fabric having a cover factor of 1500 to 3000, or a woven fabric which has been subjected to pressure compression processing and has an air permeability of 0.5 cc.
Those having a pressure of less than / cm ² / sec are particularly preferable in terms of non-breathability.

The cover factor of such a woven fabric is the sum of the product of the square root of the yarn denier and the number of yarns per inch and the weft. In addition, as a method for pressure compression processing, a roll method in which a fabric is pressed between both rolls by a device composed of a pair of flat rolls and passed at a constant speed, or a press method in which pressure is applied for a predetermined time by a pressure press Etc. can be used. The heating temperature of such rolls and presses can be appropriately set to a temperature equal to or lower than the melting point of the material of the woven fabric to be used, but it is preferably determined in combination with the applied pressure.

The film referred to in the present invention is an unstretched or stretched film composed of polyester, polyamide, polyethylene, polypropylene or the like, and is not particularly limited. The thickness of the film is not particularly limited because it depends on the properties of the film,
50 to 500 microns is preferred. Also, the film is
It may be a film alone or a composite with a fiber cloth.

As the radiation used in the irradiation of the present invention, various ionizing radiations such as α-rays, β-rays, γ-rays, X-rays, electron rays and neutron rays can be used, but are not particularly limited. Not a thing. Of these ionizing radiation,
An electron beam is preferably used in terms of workability, economy, adjustment of the degree of crosslinking, and the like. The irradiation dose of the electron beam is preferably 10 to 200 Mrad, more preferably 30 to 100 Mrad. If it is less than 10 Mrad, the crosslinking effect is too small, and if it exceeds 200 Mrad, the base material tends to shrink or become colored, which causes trouble.

The degree of existence of the crosslinked structure of the present invention can be judged from the weight of the insoluble component, when the base polymer is dissolved in the solvent of the polymer, the crosslinked portion is insoluble in the solvent. That is, in the case of nylon, formic acid, and in the case of polyester, if dissolved in a mixed solvent of phenol and ethane tetrachloride, the crosslinked portion of the base material can be confirmed as an insoluble substance without being completely dissolved.

The amount of the portion having such a crosslinked structure is preferably 30 to 95%, more preferably 45 to 80%, based on the weight of the substrate, for the above-mentioned purpose of the present invention. .

[0017]

EXAMPLES The present invention will be described in more detail with reference to examples. Incidentally, for the lightness, air barrier property, heat resistance, flexibility and storability of the airbag in the examples, the following methods are used for mass, air flow rate, flame resistance, flame retardancy, bending resistance, and foldability. Was measured by.

Mass: Determined according to the mass measurement method of JIS K6328. Airflow rate: The airflow rate was determined according to the JIS A1096 method A. Difficult to melt: Using the NM-1 type anti-melting tester manufactured by Daiei Kagaku Seiki Seisakusho, surface temperature of 360 ° C for 5 seconds, leave the iron tip on the rubber surface, and find the perforated area after light removal Expressed in grades. Grade Perforated area 5th class 0 4th class 1/8 3rd class 1/4 2nd class 1/2 1st class 1 Flame retardancy: Burning speed (m / min) was determined according to the MVSS 302 method (horizontal method). Stiffness: Stiffness (mm) was determined according to the 45 ° cantilever method of JIS L1096. The coated product was measured with the rubber side facing up. Foldability: 3cm x 15cm base cloth is folded in three,
The bulkiness when a load of 7.5 g is applied is measured and compared. That is, as a standard product, 45 g of silicone rubber
/ M ² coating prepared, the bulkiness of this standard product is 1
It is shown as a relative value when 00 is set.

Examples 1 to 6 Using a nylon 6.6 fiber having a total fineness of 420 denier, 72 filaments and a strength of 8.1 g / d, a plain woven fabric with a cover factor of 2254 having 55 warps and wefts per inch. Was woven, scoured, dried, and intermediately set by a conventional method. Then, this plain fabric was accelerated by an electron beam irradiation device (manufactured by Nisshin High Voltage Co., Ltd.) at an accelerating voltage
Electron beam irradiation was performed at 00 KV under the conditions shown in Table 1.

The evaluation results of the non-coated airbag base fabric thus obtained are shown in Table 1. The non-coated airbag base fabric of the present invention was lightweight and excellent in melting resistance, and also excellent in foldability, that is, storability.

Comparative Examples 1 and 2 A plain woven fabric having a total fineness of 420 denier, 72 filaments, nylon 6.6 fiber having a strength of 8.1 g / d, and having a warp and a weft of 55 filaments / inch and a cover factor of 2254. Was woven, scoured, dried and intermediately set by a conventional method to obtain a non-coated airbag base fabric [Comparative Example 1].

Using the same nylon 6.6 fiber as in Example 1, a plain woven fabric having a cover factor of 1845 having a warp and a weft of 46 yarns / inch was woven, and scouring, drying and intermediate setting were carried out by a conventional method. did. Then, coat with a coating liquid consisting of methyl vinyl silicone rubber with a coating viscosity of 35000 cps to a coating amount of 45 g / m ² with a comma coater, dry at 120 ° C, and then 180 ° C.
The vulcanization treatment was performed for 3 minutes to obtain a silicone rubber-coated airbag base fabric [Comparative Example 2]. The obtained airbag base fabric was evaluated in the same manner as in Example 1.

As can be seen from Table 1, the non-coated airbag base fabric of Comparative Example 1 does not have a melting property at all, whereas the silicone rubber-coated airbag base fabric of Comparative Example 2 has a poor melting property. It was excellent, but was not light enough, flexible, and foldable.

Examples 7 to 9 A plain woven fabric having a total fineness of 840 denier, 162 filaments, nylon 6.6 fibers having a strength of 8.5 g / d, and having a warp and a weft of 28 fibers / inch and a cover factor of 1623. Weaving, scouring, drying,
I set it in the middle. Next, one side of the plain woven fabric was pressed and compressed at a linear pressure of 40 Kg / cm between a metal roll having a flat surface heated to 150 ° C. and a room temperature metal roll. After that,
Using this plain weave fabric with the same electron beam irradiation device as in Example 1,
Electron beam irradiation was performed under the conditions shown in Table 1 at an acceleration voltage of 200 KV.

The non-coated airbag base fabric thus obtained was evaluated in the same manner as in Example 1. As shown in Table 1, the non-coated airbag base fabric of the present invention is
It was lightweight, had excellent air barrier properties and difficulty in melting, and was also excellent in foldability, that is, storability.

Comparative Examples 3 and 4 A plain woven fabric having a total fineness of 840 denier, 162 filaments, nylon 6.6 fibers having a strength of 8.5 g / d, and having a warp and a weft of 28 fibers / inch and a cover factor of 1623. Weaving, scouring, drying,
I set it in the middle. Then, one side of the plain woven fabric was compressed at a linear pressure of 40 kg / cm with a normal temperature metal roll having a flat surface heated to 150 ° C. to obtain a non-coated airbag base fabric [Comparative Example 3 ].

Further, the same nylon 6.6 fiber as in Example 7 was used, and a plain woven fabric having a cover factor of 1449 having 25 warps / in both wefts and wefts was woven, and scouring, drying and intermediate setting were carried out by a conventional method. did. Next, with a coating liquid consisting of chloroprene rubber and a coating viscosity of 43000 cps,
With a comma coater, the coating amount is 105 g / m 3 times.
^It is coated to ² and dried at 130 ℃, then 18
Vulcanization treatment was performed at 0 ° C. for 3 minutes to obtain a chloroprene rubber-coated airbag base fabric [Comparative Example 4]. The obtained airbag base fabric was evaluated in the same manner as in Example 1.

[0028]

[Table 1] As can be seen from Table 1, the non-coated airbag base fabric of Comparative Example 3 does not have a melting resistance at all, while the chloroprene rubber-coated airbag base fabric of Comparative Example 4 has an excellent melting property, It had a hard texture and was inferior in foldability, and there was a problem in terms of storability.

Examples 10 to 12 Using a polyester fiber having a total fineness of 500 denier, 120 filaments and a strength of 8.1 g / d, weave a plain woven fabric having a cover factor of 2146 with 48 warps and wefts per inch. did. Then, scouring, drying and intermediate setting were carried out by a conventional method. Thereafter, the plain weave fabric was subjected to an accelerating voltage of 2 using the electron beam irradiation apparatus similar to that used in Example 1.
Electron beam irradiation was carried out at 00 KV under the conditions shown in Table 2.

The non-coated airbag base fabric thus obtained was evaluated in the same manner as in Example 1.

As shown in Table 2, the non-coated airbag base fabric of the present invention was excellent in melting resistance and was also excellent in foldability, that is, storability.

Comparative Example 5 Using a polyester fiber having a total fineness of 500 denier, 120 filaments, and a strength of 8.1 g / d, a plain woven fabric having a cover factor of 2146 with 48 warps and wefts per inch was woven. Then, scouring, drying and intermediate setting were carried out by a conventional method to obtain a non-coated airbag base cloth. The non-coated airbag base fabric thus obtained was evaluated in the same manner as in Example 1.

As can be seen from Table 2, the non-coated airbag base fabric of Comparative Example 5 did not show any difficulty in melting.

Example 13 A 150-micron biaxially stretched polyester film was irradiated with an accelerating voltage of 200 K using the same electron beam irradiation apparatus as in Example 1.
The electron beam irradiation was performed under the conditions shown in Table 2 for V. The obtained non-coated airbag base material was evaluated in the same manner as in Example 1.

As shown in Table 2, the non-coated airbag film of the present invention was light in weight and was excellent in air barrier property and difficulty in melting.

Comparative Example 6 A non-coated airbag base material using a 150 micron polyester biaxially stretched film was obtained. Evaluation was performed in the same manner as in Example 1. As shown in Table 2, the non-coated airbag film of Comparative Example 6 did not show any melting resistance.

[0037]

[Table 2]

[0038]

The airbag obtained according to the present invention has the following effects.

(1) The non-coated airbag base material of the present invention has excellent melting resistance. Further, it is lightweight and has a soft texture, and the impact on the human body due to the inflation of the airbag can be reduced.

(2) The steering wheel and the instrument panel can be downsized because they are easily stored.

(3) The air barrier property and mechanical properties of the airbag are not impaired.

(4) It is advantageous in terms of workability and cost.

(5) An extremely safe and reliable airbag can be provided.

Claims (7)

[Claims] 1. A non-coated airbag base material, wherein a base material or film base material is cross-linked. 2. The non-coated airbag base material according to claim 1, wherein the portion having a crosslinked structure is 30 to 95% of the weight of the base material. 3. The non-coated airbag base material according to claim 1, wherein the base fabric is composed of a woven fabric, and the permeable amount of the woven fabric is 0.5 cc / cm ² / sec or less. 4. The non-coated airbag base material according to claim 1, wherein the base fabric is composed of a woven fabric and has a cover factor of 1500 to 3000. 5. The non-coated airbag base material according to claim 1, wherein the base fabric is made of a woven fabric and is subjected to pressure compression processing. 6. The non-coated airbag base material according to claim 1, wherein the crosslinked structure is formed by a radiation irradiation treatment. 7. The non-coated airbag base material according to claim 5, wherein the radiation irradiation treatment is an electron beam irradiation treatment.