COATED FABRIC AND AIR BAG COMPRISING THE SAME

Abstract

The present application relates to a coated fabric and an air bag comprising the same.

Claims

1. A coated fabric comprising: a fibrous substrate (A), and a coating layer (B) formed on the fibrous substrate, wherein the coating layer comprises a binder resin and a filler, wherein the filler is dispersed in the coating layer, and wherein the filler comprises at least one of chopped ceramic fibers and agglomerates thereof.

2. The coated fabric according to claim 1, wherein: the ceramic fiber comprises oxides, nitrides or carbides of at least one selected among Si, Al, Ti, Zr, Ca and Mg.

3. The coated fabric according to claim 2, wherein: the ceramic fiber comprises oxides of at least one selected among Si, Al, Ti, Zr, Ca and Mg.

4. The coated fabric according to claim 3, wherein: the ceramic fiber comprises SiO.sub.2, CaO and MgO.

5. The coated fabric according to claim 4, wherein: the ceramic fiber contains 50 to 60% by weight of SiO.sub.2, 20 to 30% by weight of CaO, and 10 to 30% by weight of MgO.

6. The coated fabric according to claim 1, wherein: the binder resin comprises at least one selected among a urethane resin and a silicone resin.

7. The coated fabric according to claim 1, wherein: the coating layer contains the filler in an amount of 20% by weight or less, based on 100% by weight of the entire coating layer.

8. The coated fabric according to claim 1, wherein: a coating amount of the coating layer to one layer of the fibrous substrate is 100 gsm or less.

9. The coated fabric according to claim 1, wherein: the fibrous substrate comprises at least one selected among a polyester fiber, an aramid fiber, a nylon fiber, a carbon fiber, a polyketone fiber, a cellulose fiber, a polyolefin fiber, and an acrylic fiber.

10. The coated fabric according to claim 9, wherein: the fiber contained in the fibrous substrate has a fineness in the range of 450 to 1,100 dtex.

11. The coated fabric according to claim 9, wherein: the fibrous substrate is a fabric comprising warp and weft threads, and the warp and weft densities of the fabric are within the range of 20 to 55 th/inch, respectively.

12. The coated fabric according to claim 1, wherein: the coated fabric has a weight of 350 g/m.sup.2 or less.

13. The coated fabric according to claim 1, wherein: the coated fabric has a thickness of 0.25 to 0.40 mm.

14. A method for preparing a coated fabric comprising: coating a coating composition comprising a binder resin and a filler onto a fibrous substrate and then curing the coated composition, wherein the filler comprises at least one of chopped ceramic fibers and agglomerates thereof.

15. An air bag comprising the coated fabric according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0050] FIG. 1 schematically shows an inflator damage evaluation method and its results. Specifically, FIG. 1a is an image for schematically showing the method of installing the inflator and fabric used for the evaluation, and FIGS. 1b, 1c and 1d are images obtained by photographing the heat resistance evaluation results of Example 1, Comparative Example 1, and Comparative Example 2, respectively.

[0051] FIG. 2 is an image of the surface of the coating layer according to an embodiment of the present application taken with an optical microscope. It can be confirmed that the agglomerated form of the filler is visually recognized in a darker shade. The size of the filler confirmed in FIG. 2 is in the range of 0.1 to 2.0 mm.

[0052] FIG. 3 is a view showing a comparison of heat resistance and durability evaluation results (hot-rod evaluation) and agglomeration characteristics according to the type of filler. Specifically, FIG. 3a is an experimental result showing that the CBF (ceramic bulk fiber) provides better heat resistance and durability through hot-rod evaluation. Further, FIG. 3b is a schematic diagram for explaining the reason why heat resistance and durability differ depending on the type of filler and the agglomeration characteristics. As shown in FIG. 3b, since the CBF has a stronger tendency to agglomerate compared to other ceramic fillers, damage to the coating layer forming resin can be suppressed under high temperature/high pressure conditions.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] Hereinafter, the action and effect of the invention will be described in more detail with reference to specific examples of the invention. However, these examples are presented for illustrative purposes only and the scope of the invention is not limited thereby in any way.

EXAMPLE AND COMPARATIVE EXAMPLE

Example 1

[0054] Preparation of coating composition: A composition containing TCS 7516 by Elkem Silicones which is a silicone-based binder resin, and a ceramic bulk fiber (ceramic fiber composed of SiO.sub.2 55 wt. %, CaO 25 wt. %, and MgO 20 wt. %) was prepared. At this time, the content of the ceramic bulk fiber was adjusted to be about 10 wt. % in the final cured coating layer.

[0055] Preparation of coated fabric: A fabric was prepared from a PET fiber having a fineness of 550 dtex. Specifically, a fabric (1 layer) having a fabric density of 4646 th/inch (warpweft) was prepared, and the prepared composition was coated onto the fabric at a level of about 87 gsm. Then, curing was carried out at a temperature of 160 to 190 C. for at least 1 minute 30 seconds using a hot air chamber, and a woven fabric was prepared. The weight of the prepared coated fabric was 315 g/m.sup.2, and the thickness was about 0.33 mm (see FIG. 2).

Comparative Example 1

[0056] Preparation of coating composition: TCS 7517 by Elkem Silicones was prepared as a silicone-based binder resin.

[0057] Preparation of coated fabric: A fabric was prepared from a PA66 fiber having a fineness of 470 dtex. Specifically, a fabric (1 layer) having a fabric density of 4646 th/inch (warpweft) was prepared. Then, the prepared coating composition was coated onto the prepared fabric at a level of about 122 gsm (the coating amount was about 50 gsm more than in Example 1), and then cured under the same conditions as in Example 1. The weight of the prepared coated fabric was 308 g/m.sup.2 and the thickness was about 0.33 mm.

Comparative Example 2

[0058] Preparation of coating composition: DC3730 by Dow Corning which is a urethane-based binder resin was prepared.

[0059] Preparation of coated fabric: A fabric was prepared from a PA66 fiber having a fineness of 470 dtex. Specifically, a fabric having a fabric density of 11296 th/inch (warpweft) was prepared (binded 2 layers. Unlike Example and Comparative Example 1, a two-layer fabric was used). Then, the prepared composition was coated onto the fabric at a level of about 69 gsm. The weight of the prepared coated fabric was 512 g/m.sup.2 and the thickness was about 0.66 mm.

[0060] Evaluation 1: Evaluation of Heat Resistance Durability of Coated Fabrics

[0061] The heat resistance of the coated fabrics prepared in Examples and Comparative Examples was evaluated by the following method.

[0062] 1. HOT-ROD Evaluation

[0063] Specifically, a columnar rod (10 mm in diameter, 80 mm in length, and 50 g in weight) was prepared, and the rod was heated to the desired 600 C. and brough into contact with the coated fabric. Then, the time (in seconds) until the rod completely melts the fabric and then falls down was measured, and the results are shown in Table 1 below.

[0064] 2. Inflator Damage Evaluation

[0065] The heat shield fabric was wrapped as a single layer inside the jig of dual inflator for DAB (KSS), and the coated fabrics of Examples and Comparative Examples were wrapped as 6 layers to prepare a specimen (see FIG. 1a). Then, the process of deploying the airbag was simulated so that high-temperature and high-pressure gas was applied to the specimen. At this time, the high temperature and high pressure gas was controlled to be applied at a maximum pressure of 180 to 270 Kpa for 40 to 80 ms.

[0066] Then, the number (n) of damaged fabrics and the number (m) of holes found in these damaged fabrics among the five-ply coated fabrics were measured, and the weighted value of n was set to 10 and the weighted value of m was set to 1, and the evaluation results were digitized as follows. As the damage score is lower, the heat resistance is better.

Damage score=(n10)+(mn1)

TABLE-US-00001 TABLE 1 Comparative Comparative Example 1 Example 1 Example 2 HOT-ROD evaluation (sec) 5.3 4.1 3.6 Inflator Number of damaged 2 4 4 damage fabric (layer) evaluation Score 24 44 44

[0067] Evaluation 2: Comparison of Heat Resistance and Durability by Filler

[0068] The filler type of the coated fabric prepared in Example 1 was changed as shown in FIG. 3a, and the above-mentioned HOT-ROD evaluation results were compared. Specifically, the content of the filler in the coating layer was equally applied at 5 wt. %, and HOT-ROD evaluation was conducted for the case of using CBF (ceramic bulk fiber), conventional ceramic filler (Mica (D50 number distribution size of about 40 um), Silica (D50 number distribution size of about 20-30 um), Talc (D50 number distribution size of about 20-30 um) and CF (carbon fiber) filler (about 2-3 mm in size). The Y-axis result is the arithmetic mean value (unit: seconds) after the evaluation progresses about 10 times.