JPH06305089A - Production of base fabric for air bag - Google Patents

Abstract

PURPOSE:To obtain the excellent bonding strength of a polyester type elastomer layer to a fabric by subjecting at least the single surface of the fabric to plasma treatment and subsequently laminating the polyester type elastomer layer to the treated fabric. CONSTITUTION:At least the single surface of a fabric is subjected to plasma treatment and a polyester type elastomer layer is laminated to the treated fabric. A base fabric A for an air bag is constituted of a fabric 3 and a polyester type elastomer layer 13 and a plasma treatment surface 12 is formed on the upper surface of the fabric 3. The polyester type elastomer layer 13 is provided in order to easily hermetically close the fabric 3 by heat and to impart flexibility, toughness and ageing resistance to the air bag. The polyester type elastomer layer 13 is laminated by placing a film like polyester type elastomer on the plasma treated surface 12 using an extursion laminator to laminate the same on the plasma treated surface.

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 an air bag base cloth used for the purpose of ensuring the safety of passengers in the event of an automobile accident.

[0002]

2. Description of the Related Art In recent years, an air bag system for protecting passengers in the event of an accident has been put into practical use in various transportation means, particularly in automobiles.

The air bag used in this air bag system, when a vehicle such as an automobile has collided with it, has a shock more than a predetermined value, and a starting device is actuated to expand and deploy a high pressure gas or the like to exert a cushioning function. This makes it possible to save lives. For example, the sensor senses an impact and transmits it to the detonator to ignite the explosive, thereby burning the gas generating agent and generating nitrogen gas, thereby inflating and expanding the airbag.

In a normal air bag that is inflated and deployed in this manner, the time from when the car collides with the air bag to start to inflate until it deflates is 0.2 seconds, and the internal pressure at the time of gas generation is 120 atm maximum. Also reaches.

In order to increase the popularization rate of air bags as standard equipment, it is necessary to further enhance the safety of the air bags as well as the strength of other parts.

FIG. 4 is a sectional view showing a conventional air bag base cloth. This air bag base fabric is disclosed in JP-A-3-
7337, the cloth foil 3 is laminated with the polyester elastomer layer 13 via the primer coat layer 10.

Examples of the cloth foil 3 include natural fiber, polyamide fiber, aramid fiber, polyester fiber, vinylon fiber, rayon fiber, polyolefin fiber, polyoxymethylene fiber, sulfone fiber, polyetheretherketone fiber, carbon fiber and glass. Fiber, ceramic fiber,
Inorganic fibers such as metal fibers can be exemplified.

The primer coat layer 10 is a layer for adhering the cloth foil 3 and the elastomer layer 13 described below,
The material forming this layer 10 is a polyurethane resin,
A two-component curing type adhesive composed of an adhesive composed of a polyester resin and a curing agent composed of an aliphatic isocyanate system or an aromatic isocyanate system can be exemplified.

A polyester elastomer is preferably used for the elastomer layer 13 provided in contact with the primer coat layer 10. As this polyester elastomer, for example, an elastomer commercially available from Dainippon Ink and Chemicals, Inc. under the trade name of Grelax E can be exemplified.

This elastomer is disclosed in JP-A-61-403.
55, for example, a high melting point hard segment mainly composed of alkylene terephthalate units,
It is a block copolymer with a low-melting point soft segment composed of an aliphatic polyether and / or an aliphatic polyester.

The air bag base cloth is obtained by applying or laminating a primer coat on both sides or one side of the cloth foil 3 and then forming the polyester elastomer layer 13 on the primer coat layer 10. it can. This polyester elastomer layer 13
Can be formed, for example, by forming a polyester elastomer into a film using an extrusion laminator and laminating the film.

Then, two pieces of the obtained base cloth, which are cut into a predetermined shape, are superposed so that the polyester elastomer layers are in contact with each other, and the peripheral portions thereof are heat-sealed so that the two pieces are integrated to form air. A back can be formed.

[0013]

However, in the conventional base cloth in which the polyester elastomer layer 13 is formed on the surface of the cloth foil 3 via the primer coat layer 10, the adhesion of the primer coat layer 10 to the cloth foil 3 is difficult. I was weak. Therefore, the adhesive force of the polyester elastomer layer 13 to the cloth foil 3 was weak.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for producing an air bag base cloth in which a polyester-based elastomer layer has an excellent adhesive force to a cloth foil. To aim.

[0015]

In the method for manufacturing a base fabric for an air bag of the present invention, at least one side of the fabric foil is subjected to plasma treatment, and then a polyester elastomer layer is laminated to solve the above object.

FIG. 1 is a sectional view showing an air bag base fabric A according to the present invention. This air bag base fabric A
Comprises a cloth foil 3 and a polyester-based elastomer layer 13, and a plasma treated surface 12 is formed on the upper surface of the cloth foil 3. As the material forming the cloth foil 3, the same material as the conventional one can be used,
Represented by natural fibers such as cotton, silk, and hemp, polyamide fibers such as nylon 6, nylon 66, and nylon 64, aramid fibers represented by a copolymer of paraphenylene terephthalamide and aromatic ether, and polyalkylene terephthalate. Polyester fiber, wholly aromatic polyester fiber, vinylon fiber, rayon fiber, polyolefin fiber such as ultra high molecular weight polyethylene, polyoxymethylene fiber, sulfone fiber such as paraphenylene sulfone and polysulfone, polyether ether ketone fiber, carbon A fiber etc. can be illustrated. In addition, inorganic fibers such as glass fibers, ceramic fibers, and metal fibers may be used alone or in combination.

The polyester elastomer layer 13 is a layer provided to easily seal the cloth foil 3 by heat and to impart flexibility, toughness, and aging resistance to the air bag, and has been conventionally used. Materials available, for example, the elastomer commercially available from Dainippon Ink and Chemicals, Inc. under the trade name Grelax E can be used.
This polyester-based elastomer is a polyester-based copolymer composition described below. That is, this composition contains the polyester copolymer (A) and the carboxyl group- and / or epoxy group-containing olefin copolymer (B) (A) / (B) = 95/5 to 30/70 (weight ratio).
Is mixed in the following ratio.
55, for example, a high melting point hard segment mainly composed of alkylene terephthalate units,
It is a block copolymer with a low-melting point soft segment composed of an aliphatic polyether and / or an aliphatic polyester.

The characteristics of the above polyester elastomer are excellent in tensile strength, tear strength, cold resistance, abrasion resistance, bending resistance, etc., and have heat aging resistance, hydrolysis resistance and high flexibility. A thermoplastic resin that is generally used is also satisfactory as a material used as a base fabric for an air bag when attention is paid only to the heat-sealing property. However, it is not preferable as a material used for an air bag base cloth because of insufficient properties as an elastomer, insufficient heat resistance, and the like.

Next, a method for manufacturing the air bag base fabric A shown in FIG. 1 will be described. First, plasma treatment is applied to one surface of the cloth foil 3 to form a plasma-treated surface 12.
The method will be described below.

In the present invention, the processing is performed using a parallel plate electrode type plasma device as shown in FIG. 2, for example. This parallel plate electrode type plasma device has a bell jar 1,
Two electrode plates 2a and 2b are placed inside. The inside of the bell jar 1 is a sealed space, and is depressurized and maintained at a constant pressure during plasma processing. A high frequency power source 4 is arranged outside the bell jar 1, and a gas supply path 5 for supplying gas is also attached inside.

In FIG. 2, reference numeral 6 indicates an electrode support for supporting the upper electrode plate 2a, and reference numeral 7 indicates an exhaust port for exhausting gas in the bell jar.

In order to perform the plasma treatment on one side of the cloth foil 3, first, the cloth foil 3 is placed on the lower electrode plates 2b of the two electrode plates 2a and 2b arranged in equilibrium with each other in the bell jar 1.
Then, a high voltage is applied between the electrode plates 2a and 2b by the high frequency power source 4 to create a plasma atmosphere. Then, gas is supplied from the gas supply path 5 into the plasma atmosphere,
Treat the upper surface of the cloth foil 3. In this case, plasma treatment is performed on one surface, so it is preferable to mask the untreated surface so that the back surface is not affected.

Examples of the gas supplied into the plasma atmosphere include oxygen gas, nitrogen gas, argon gas, helium gas, hydrogen gas, dry air, ammonia gas and the like.

The high frequency power source 4 (frequency is 13.56M
The output of Hz) is within the range of ^{0.1W / cm 2 ~20W / cm 2} , it is preferably set particularly in the range of ^{0.1W / cm 2 ~2.0W / cm 2} . 20 W / cm ²
If it is larger than this, the output of the plasma treatment is too strong and the cloth foil 3 exposed to it is easily deteriorated, which is not preferable. On the other hand, if it is smaller than 0.1 W / cm ² , the space between the two electrode plates is 2
Plasma is not generated in a and 2b, which is not preferable.

The pressure inside the bell jar 1 when the cloth foil 3 is subjected to the plasma treatment is preferably set within the range of 0.01 Torr to 10 Torr, particularly within the range of 0.05 Torr to 2 Torr. A sufficient plasma treatment effect cannot be obtained under a pressure of 0.01 Torr or less.

Further, the time for performing the plasma treatment on the cloth foil 3 is within the range of 0.5 seconds to 10 minutes, and particularly 10 seconds to.
It is preferably within a range of 5 minutes. If it is shorter than 0.5 seconds, the plasma treatment cannot be sufficiently performed, and if it is longer than 10 minutes, the cloth foil 3 is deteriorated, which is not preferable.

To obtain the air bag base fabric A, a polyester elastomer layer 13 is formed on the plasma treated surface 12.
Are stacked. As a laminating method, for example, a method in which an extruding laminator is used to place a film-shaped polyester elastomer on the plasma-treated surface 12 and laminating it is exemplified.

In this way, the plasma treated surface 12 is formed on the surface of the cloth foil 3, and the polyester elastomer layer 13 is laminated on the surface 12 to obtain the air bag base cloth A of the present invention. You can

Further, two pieces of the obtained air bag base cloth were cut into a predetermined shape, aligned so that the polyester elastomer layers 13 were overlapped with each other, and the peripheral portions thereof were integrated, as shown in FIG. You can get an air bag. The most preferable method for integrating the two base cloths is a method of bringing them into close contact with each other by heat or a heat sealing method. In FIG. 3, reference numeral 14 indicates a joint portion between two air bag base fabrics, and 15 indicates a gas inlet. Although the plasma-treated surface 12 is formed on one side of the cloth foil 3 in the above example, it may be formed on both sides. When applying on both sides,
It is also possible to treat one side first and then the other side, or to set both sides of the cloth foil so that the modification effect by the plasma treatment is exerted. However,
These methods are merely examples, and the plasma treatment according to the present invention is not limited to these.
Furthermore, it is possible to laminate a primer coat layer as in the conventional case. That is, the surface of the cloth foil 3 may be plasma-treated to form the plasma-treated surface 12, a primer coat layer may be provided on the plasma-treated surface 12, and then the polyester elastomer layer 13 may be provided. At this time, the preferable coating amount of the primer coat on the plasma treated surface 12 is 3 to 10 g / m ² . 10 g / m
^{If it is} more than ^2, the thickness of the primer coat layer 10 becomes thicker and the base cloth becomes harder. Then, when an air bag, which is a product, is manufactured, the foldability decreases, which is not preferable. ^{On the other hand, if} it is less than 3 g / m ² , the adhesiveness between the above fiber and the following elastomer cannot be sufficiently improved, which is not preferable.

[0030]

The method for producing the base fabric for an air bag of the present invention is a method in which at least one side of the cloth foil is subjected to plasma treatment and then a polyester elastomer layer is laminated. The fiber surface of the cloth foil can be modified by performing the plasma treatment.

[0031]

EXAMPLES The method for manufacturing the air bag base fabric of the present invention will be described in detail below. The same components as those of the conventional example are designated by the same reference numerals to simplify the description.

(Example 1) Nylon 6 having a thickness of 260 μm
Prepare plain weave cloth foil 3 consisting of 6 and put the cloth foil 3
The parallel plate electrode type plasma device shown in FIG. 2 was placed on the lower electrode 2b and the upper surface thereof was plasma-treated.

The condition of the plasma treatment is that the wavelength is 13.56.
MHz and the output is 1 W / cm ² . The pressure inside the bell jar 1 was 0.1 Torr, and the inside was filled with argon gas. Under these conditions, the upper surface of the cloth foil 3 was brought into contact with plasma for 10 seconds to modify the upper surface of the cloth foil 3.

Next, a polyester elastomer (manufactured by Dainippon Ink and Chemicals, Inc., trade name: Grelax E)
Was formed into a film having a thickness of 80 μm using an extrusion laminator, which was laminated on the surface of the plasma-treated cloth foil to form the air bag base cloth of the present invention.

(Embodiment 2) Oxygen gas was used as the gas filled in the bell jar 1 of the parallel plate electrode type plasma apparatus, the output of plasma was changed to 0.7 W / cm ² , and the plasma contact time was 20. An air bag base fabric according to the present example was obtained in the same manner as in Example 1 except that the number of seconds was changed.

(Comparative Example 1) With the cloth foil used in Example 1, a primer coat layer was formed without plasma-treating the same cloth foil surface, and the polyester elastomer layer was formed in the same manner as in Example 1. Were laminated to obtain an air bag base fabric for a comparative example.

The primer coat layer was formed by applying a coating liquid having the following composition to a cloth foil. The coating amount was adjusted so that the weight after drying was 5 to 7 g / m ² .

The above composition is shown below.

-Polyester resin (solid content 62% by weight) 15 parts by weight (Dainippon Ink and Chemicals, Inc., trade name: EPS-703A) -Fatty isocyanate curing agent 1 part by weight-Ethyl acetate 8 parts by weight The air bag base fabrics obtained in Examples 1 and 2 and Comparative Example 1 were evaluated as follows.

Adhesion between cloth foil and polyester elastomer layer Measured by the method described in JIS standard K6301.

Penetration time When a water droplet of about 1.5 μl was dropped on the surface of the cloth foil, the time until the water droplet completely penetrated the cloth foil and the reflected light disappeared was measured. An Elmagoniometer type contact angle measuring instrument GI type (manufactured by Elma Co.) was used for the measurement.

Table 1 shows the measurement results.

[0043] As is clear from Table 1 above, although the adhesive force between the cloth foil and the polyester elastomer layer of the air bag base fabric obtained in Examples 1 and 2 is excellent, it was obtained in Comparative Example 1. It was found that the base cloth had a weak adhesive force and had a practical problem.

The permeation times of the base fabrics obtained in Examples 1 and 2 are significantly shorter than those of the base fabrics obtained in Comparative Examples. The short permeation time means that the surface energy is large, that is, the liquid easily permeates the surface of the cloth.

That is, it has been found that the plasma treatment modifies the surface of the cloth foil to increase the surface energy, thereby improving the adhesive force between the cloth foil and the polyester elastomer layer.

[0046]

Industrial Applicability The method for producing a base fabric for an air bag according to the present invention comprises subjecting at least one side of a fabric foil to plasma treatment,
Next, the method is characterized by laminating a polyester elastomer layer. By plasma treatment,
The fiber surface of the cloth foil can be modified. Therefore, it is possible to provide a base fabric for an air bag in which the polyester elastomer layer has an excellent adhesive force to the fabric foil.

Further, according to the method for manufacturing a base fabric for an air bag of the present invention, it is not necessary to provide an adhesive layer (primer coat layer) which has been conventionally required. Therefore, it is possible to provide an air bag base fabric that is easy to manufacture and is inexpensive and thin.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an air bag base fabric manufactured by a method for manufacturing an air bag base fabric of the present invention.

FIG. 2 is a schematic side view showing an air bag manufactured using the air bag base fabric of the present invention.

FIG. 3 is a schematic view showing an example of an apparatus used for plasma processing.

FIG. 4 is a cross-sectional view showing a conventional airbag base fabric.

[Explanation of symbols]

 1 Bell jar 2 Electrode plate 3 Cloth foil 4 High frequency power supply 5 Gas supply path 6 Electrode column 7 Exhaust port 10 Primer coat layer 12 Plasma treated surface 13 Joint part 15 Gas injection port

Claims (1)

[Claims] 1. A method for producing a base fabric for an air bag, which comprises subjecting at least one side of a cloth foil to a plasma treatment, and then laminating a polyester elastomer layer.