JP4453040B2 - Airbag fabric - Google Patents

Description

  An object of the present invention is to provide a fabric for an air bag which is one of automobile safety devices having low cost, self-extinguishing properties and low air permeability.

  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. Conventionally, coated 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 retardancy.

  However, fabrics coated with these synthetic rubbers have many problems in use as airbag fabrics because the fabric weight increases, the flexibility is not satisfactory, and the production costs are high. In addition, self-extinguishing properties cannot be achieved in terms of combustibility, and improvements are demanded.

Changing the coating application amount has been known and improved, but the air permeability and flammability are not satisfactory and there is a need for improvement. (For example, refer to Patent Document 1.)
JP-A-5-16753

On the other hand, non-coated airbags using non-coated airbag fabrics that are lightweight and have a good storage property are not the mainstream. (For example, refer to Patent Document 2) However, an airbag close to the occupant, such as a side airbag, requires a higher deployment performance, and therefore, a fabric for an airbag having a lower ventilation performance is required. ing.
JP-A-4-281062

Currently, impregnation treatment with a synthetic resin diluent has been proposed as a fabric for airbags that is flame retardant, has low air permeability and high slip resistance, while maintaining the light weight and good storage characteristics that are the characteristics of non-coated fabrics. . (For example, refer to Patent Document 3.) However, the low ventilation performance is not fully satisfactory.
JP-A-11-222776

  The present invention is intended to provide a fabric for an air bag that is low-cost, self-extinguishing, and low air permeability, which cannot be solved by the conventional method.

The present invention has the following configuration in order to solve the problems that could not be achieved by the above conventional method. That is, this invention consists of the following structures.
1. A synthetic fiber fabric in which a thermoplastic synthetic resin is applied on at least one side, wherein the thermoplastic synthetic resin is a polyamide-based resin, and has a soft segment with a molecular weight of 100 to 5000 in the polymer of the polyamide-based resin , A fabric for an air bag, wherein the air permeability under a differential pressure of 100 kPa of the fabric is 0.10 L / cm 2 / min or less, and the flammability is self-extinguishing.
2. ^{2. The} airbag fabric according to 1 above, wherein the adhesion amount of the thermoplastic synthetic resin is 0.1 to 15 g / m ² in terms of mass after drying.
3. The molecular weight of the soft segment is 300 to 3000,
The fabric for an air bag according to any one of items 1 and 2.
4). The molecular weight of the soft segment is 600-1500,
The fabric for airbags of any one of Claims 1-3.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a fabric for an air bag that is one of automobile safety devices that are low in cost, self-extinguishing, and having low air permeability.

Hereinafter, the present invention will be described in detail.
In the present invention, the material is not particularly limited as a synthetic fiber, but in particular, an aliphatic polyamide fiber such as nylon 66, nylon 6, nylon 46, nylon 12 or the like, an aromatic polyamide fiber such as an aramid fiber, polyethylene terephthalate, Polyester fibers such as polytrimethylene terephthalate and polybutylene terephthalate are used. Other examples include wholly aromatic polyester fibers, polyparaphenine / benzobis / oxazole fibers (PBO fibers), ultrahigh molecular weight polyethylene fibers, polyphenylene sulfide fibers, and polyether ketone fibers. 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. Moreover, in order to improve the process passability in the raw yarn manufacturing process and the post-processing process, these synthetic fibers have no problem even if they contain various additives. For example, antioxidants, heat stabilizers, smoothing agents, antistatic agents, thickeners, flame retardants and the like. Moreover, there is no problem even if this synthetic fiber is dyed after original yarn or after yarn production. The cross section of the single yarn may be any irregular cross section other than the normal round cross section. The synthetic fiber is preferably woven as a multifilament yarn from the viewpoints of breaking strength and breaking elongation.

  In the present invention, the weaving method is not particularly limited, but plain weaving is preferable in consideration of the uniformity of the physical properties of the fabric. The yarn to be used may not be a single warp and weft. For example, there is no problem even if the thickness, the number of yarns, and the type of fiber are different. The loom is not particularly limited, such as an air jet loom, a rapier room, or a water jet loom.

  The fabric in the present invention is produced, for example, by applying a thermoplastic synthetic resin to a fabric woven by a known method. Thermosetting silicone resin is widely used as an existing coating agent for airbags, but since a sufficient amount of heat is required for curing, the cost increases. Therefore, in the present invention, a thermoplastic resin is used. It is essential to use it. The coating method is not particularly limited, and a known method can be used, but it is preferable to use knife coating in consideration of cost and flexibility of the fabric after coating.

  In the present invention, polyurethane-based resins, acrylic resins, polyester-based resins, and polyamide-based resins can be used as the thermoplastic synthetic resin to be applied to the woven fabric, but polyamide-based resins including soft segments having a molecular weight of 100 to 5000 are used. Is preferably used. More preferably, the molecular weight is 300 to 3000. If the molecular weight is less than 100, the fabric flexibility after coating tends to be poor, which is not preferable. If the molecular weight is more than 5000, it is not preferable from the viewpoint of combustibility. Here, the soft segment refers to the entire polyol, but an amino-modified product of linear polyalkylene glycol is particularly preferable, and an amino-modified product of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, or polybutylene glycol is more preferable. The soft segment is preferably 25 to 50% of the polyamide resin in terms of a molar ratio in the polymer. If it is less than 25%, the flexibility of the fabric after application tends to be poor, and the air permeability tends to increase, which is not preferable. If it exceeds 50%, it is not preferable from the viewpoint of combustibility. These thermoplastic synthetic resins may be used in admixture with additives such as deterioration inhibitors, inorganic fillers, colorants and the like as long as the target performance is not affected.

In the present invention, the woven fabric formed by applying a thermoplastic synthetic resin preferably has an air permeability under a differential pressure of 100 kPa of 0.10 L / cm ² / min or less, and the flammability of the woven fabric is self-extinguishing. It is preferable. Air permeability less, more preferably 0.05L ^/ cm 2 ^/ min at 100kPa difference pressure, more preferably not more than 0.02L ^/ cm 2 ^/ min. If the air permeability under a differential pressure of 100 kPa is higher than 0.10 L / cm ² / min, it is not preferable because the occupant restraint performance when used as an airbag cannot be satisfied.

In the present invention, the weight of the thermoplastic synthetic resin after drying is preferably 0.1-15 g / m ² , more preferably 1.0-10 g / m ² , and still more preferably 1.0-5.0 g / m ^2. a m ^2. The mass after drying is the value obtained by measuring the mass after coating and drying according to JIS L1096 8.4.2, and subtracting the value obtained by measuring the mass before coating according to JIS L1096 8.4.2. Is. If it is less than 0.1 g / m ² , the air permeability tends to be large, which is not so preferable. If it is more than 15 g / m ² , flexibility tends to be impaired and the cost increases.

  In the present invention, the combustibility preferably achieves self-extinguishing properties. Here, the self-extinguishing property is a category defined by JIS-D1201, which means that the fire extinguished before reaching the A mark line, or the fire extinguished within 50 mm, and extinguished within 60 seconds. Here, flammability is the most basic characteristic required for airbag fabrics, and it is very preferable from the viewpoint of safety that this characteristic is self-extinguishing. Of the self-extinguishing properties, it is more preferable to extinguish before reaching the A mark.

Next, the present invention will be described in more detail with reference to examples. In addition, various evaluation in an Example was performed in accordance with the following method.
Flammability: FMVSS No. 302 horizontal method. JIS D1201 is used for flammability classification.
Air permeability: The air permeability under a pressure of 100 kPa was measured using a high pressure air permeability measuring machine (manufactured by OEM System Co., Ltd.).

Example 1
A polyamide 66 multifilament yarn with a total fineness of 350 dtex and 108 filaments is woven in a plain weave in a water jet loom, shrunk with boiling water, dried at 110 ° C, and a warp density of 59 / 2.54 cm, weft A woven fabric having a density of 59 / 2.54 cm was obtained. Polyamide 6 and polyethylene glycol-propylamine adduct (molecular weight 6)
00) and adipic acid in a molar ratio of 2.5: 1: 1 were prepared as an aqueous resin having a solid content of 25%, applied by knife coating, and the amount of resin after drying was 4 g / m. The properties of the woven fabric made into ² were evaluated and are shown in Table 1.

(Example 2)
A polyamide 66 multifilament yarn with a total fineness of 350 dtex and 108 filaments is woven in a plain weave in a water jet loom, shrunk with boiling water, dried at 110 ° C, and a warp density of 59 / 2.54 cm, weft A woven fabric having a density of 59 / 2.54 cm was obtained. Polyamide 6 and polyethylene glycol-propylamine adduct (molecular weight 1)
500) and adipic acid in a molar ratio of 2.5: 1: 1 were prepared as an aqueous resin having a solid content of 25%, applied by knife coating, and the resin amount after drying was 7 g / m. The properties of the woven fabric made into ² were evaluated and are shown in Table 1.

(Example 3)
A polyamide 66 multifilament yarn with a total fineness of 350 dtex and 108 filaments is woven in a plain weave in a water jet loom, shrunk with boiling water, dried at 110 ° C, and a warp density of 59 / 2.54 cm, weft A woven fabric having a density of 59 / 2.54 cm was obtained. Polyamide 6 and polyethylene glycol-propylamine adduct (molecular weight 6)
00) and adipic acid in a molar ratio of 2.5: 1: 1 were prepared as an aqueous resin having a solid content of 10% and impregnated to give a resin amount after drying of 7 g / m ² . The properties of the fabric were evaluated and are shown in Table 1.

Example 4
Example 1 except that a polyamide 66 multifilament yarn having a total fineness of 470 dtex and 72 filaments is used, and the finishing density is warp density 46 / 2.54 cm, weft density 46 / 2.54 cm, and the resin amount is different. The properties of the woven fabric which are the same as those described above were evaluated and shown in Table 1.

(Example 5)
Table 1 shows the evaluation of the properties of the woven fabric which are the same as those in Example 4 except that the finishing density is 54 warps / 2.54 cm, the weft density is 54 / 2.54 cm, and the resin amount is different.

(Comparative Example 1)
A polyamide 66 multifilament yarn with a total fineness of 350 dtex and 108 filaments is woven in a plain weave in a water jet loom, shrunk with boiling water, dried at 110 ° C, and a warp density of 59 / 2.54 cm, weft A woven fabric having a density of 59 / 2.54 cm was obtained. Polyamide 6 and polyethylene glycol-propylamine adduct (molecular weight 6)
000) and adipic acid in a molar ratio of 2.5: 1: 1 were prepared as an aqueous resin having a solid content of 25%, applied by knife coating, and the amount of resin after drying was 4 g / m. the characteristics of the fabric was ² shown in evaluated table 1.

(Comparative Example 2)
A polyamide 66 multifilament yarn with a total fineness of 350 dtex and 108 filaments is woven in a plain weave in a water jet loom, shrunk with boiling water, dried at 110 ° C, and a warp density of 59 / 2.54 cm, weft A woven fabric having a density of 59 / 2.54 cm was obtained. The fabric of the copolymer of polyamide 6 and polyamide 66 was prepared as a 25% solids aqueous resin, was applied by knife coating, a resin amount after drying were evaluated the characteristics of the fabric that was 4g / m ² Table It was shown in 1.

  The self-extinguishing properties here were all extinguished before reaching the A mark.

  Examples 1 to 5 can be said to be airbag fabrics that are one of automotive safety devices that are self-extinguishing and have low air permeability compared to Comparative Examples 1 and 2.

  The airbag fabric according to the present invention has self-extinguishing flammability and low air permeability, and can be used for airbag applications, which is one of automobile safety devices, and greatly contributes to the industry. It is.

Claims (4)

A synthetic fiber fabric in which a thermoplastic synthetic resin is applied on at least one side, wherein the thermoplastic synthetic resin is a polyamide-based resin, and has a soft segment with a molecular weight of 100 to 5000 in the polymer of the polyamide-based resin , A fabric for an air bag, wherein the air permeability under a differential pressure of 100 kPa of the fabric is 0.10 L / cm 2 / min or less, and the flammability is self-extinguishing. ^{2. The} airbag fabric according to claim 1, wherein the adhesion amount of the thermoplastic synthetic resin is 0.1 to 15 g / m ² in terms of mass after drying. The airbag fabric according to any one of claims 1 and 2, wherein the soft segment has a molecular weight of 300 to 3,000. 4. The airbag fabric according to claim 1, wherein the soft segment has a molecular weight of 600 to 1500. 5.