KR101367401B1 - Fabric for airbag - Google Patents

Abstract

The present invention relates to an airbag fabric, and more particularly, to an airbag fabric including polyphenylene sulfide-based fibers.

The fabric for the airbag of the present invention may include a polyphenylene sulfide-based fiber having excellent heat resistance, self-retardant resistance, mechanical properties, and the like, and thus may produce a fabric for airbags having excellent performance.

Airbag, Fabric, Polyphenylene Sulfide Fiber, Heat Resistance, Flame Retardant

Description

Fabric for Airbags {FABRIC FOR AIRBAG}

The present invention relates to an airbag fabric, and more particularly, to an airbag fabric comprising a polyphenylene sulfide-based fiber and a manufacturing method thereof.

Generally, an air bag detects a collision shock applied to a vehicle at a speed of about 40 km / h or more at a speed of about 40 km / h, and then explodes a gunpowder to expel gas into the airbag cushion. By supplying and expanding, it refers to a device that protects the driver and passengers.

Items required for airbag fabrics include low breathability for smooth deployment in the event of a crash, high strength to prevent damage and rupture of the airbag itself, high heat resistance, and flexibility to reduce impact on passengers.

In particular, since the hot gas is supplied into the airbag cushion when the airbag is inflated, the heat resistance of the fabric for the airbag plays an important role in the performance of the airbag.

Conventionally, polyamides such as nylon 6, polyethylene terephthalate (PET), and the like have been used as materials for airbag yarns. However, nylon 6 has a low melting point of about 220 ° C. and a high heat capacity, whereas PET has a high melting point of 265 ° C. and a low heat capacity.

Conventionally, in order to increase the heat resistance of such yarns, a method of adding an excessive amount of a heat resistant agent such as a metal halide compound is used. However, there is a limit in improving heat resistance due to the addition of the metal halide compound, and when an excessive amount of heat-resistant agent such as the metal halide compound is used, it may cause problems in the physical properties and processability of the fabric, and thus is not suitable as an air bag fabric. .

Therefore, there is a need for research on development of a fabric material having high melting point and heat capacity, high stability at high temperature, and excellent mechanical strength, suitable for use as an airbag fabric.

The present invention is to provide a fabric for airbags excellent in heat resistance, flame retardancy and mechanical properties.

The present invention provides a fabric for an air bag comprising a linear polyphenylene sulfide-based fiber comprising a repeating unit represented by the following formula (1).

[Formula 1]

Hereinafter, the present invention will be described in more detail.

In the present invention, the airbag fabric refers to a fabric or non-woven fabric used in the manufacture of airbags for automobiles, the general airbag fabric is used nylon 66 plain fabric or nylon nonwoven fabric woven with a rapier loom, In the present invention, it is characterized by using a linear polyphenylene sulfide-based fiber comprising a repeating unit represented by the formula (1).

In the present invention, polyphenylene sulfide (PPS, Polyphenylene Sulfide) is a linear polymer material having a repeating unit connected with an aromatic ring and a sulfur element as shown in Formula 1, melting point (T _m ) 277 ~ 285 ℃, crystallization temperature (T _c ) It has physical properties of 125-135 degreeC and melt crystallization temperature ( _Tmc ) _{220-250 degreeC} . The initial thermal decomposition temperature of the polyphenylene sulfide is at least 500 ℃ in nitrogen and air, has a high heat resistance that is completely decomposed only when reached to 700 ℃ in the air, the continuous use temperature showing long-term heat resistance is 220 ~ 240 ℃, thermal deformation The temperature HDT is 260 ° C. or more and has very good heat resistance.

In addition, the flame retardancy of the polyphenylene sulfide has excellent flame retardancy characteristics of the UL94 V-0 standard even without addition of a flame retardant, and the limiting oxygen index (LOI) is also 44-53, which is melted and molded into a fluorine resin. It is as high as that.

In the present invention, polyphenylene sulfide yarn may be used as a main component, but may be used in combination with nylon 66 yarn. In this case, the yarn in the oblique direction uses polyphenylene sulfide yarn and nylon 66 yarn as the weft direction yarn, or the yarn in the oblique direction uses nylon 66 yarn and the polyphenylene yarn as the weft direction yarn. It is appropriate to use sulfide yarns. At this time, it is most preferable that only the polyphenylene sulfide yarn is used as the yarn in the warp or weft direction, and the ratio of the polyphenylene sulfide yarn is 100%.

In the present invention, the polyphenylene sulfide-based fiber has a fineness of 210 to 840 denier, preferably 210 to 630 denier, filament number of 60 to 500, preferably 60 to 150, and tensile strength of 4.5 to 12.5 g / d, Preferably it is 7.0-10 g / d, Most preferably, it is 8.2-9.5 g / d, The thing of 3% or less of heat shrinkage can be used, It is not specifically limited to this.

In addition, the polyphenylene sulfide-based fiber may further include a copper compound, a phosphorus compound, and the like, which are known to be usable for yarns for airbags.

In the present invention, the weaving of the fabric is not limited to a specific form, and both the plain weave type and the OPW (One Piece Woven) weave type are preferable.

The polyphenylene sulfide-based airbag fabric of the present invention may be manufactured through beaming, weaving, refining, and tenter processes using the polyphenylene sulfide yarn as a weft and a warp yarn. The fabric may be manufactured using a conventional weaving machine, and is not limited to the use of any specific loom. However, plain weave fabrics can be manufactured using rapier looms, air jet looms, or water jet looms. OPW fabrics are Jacquard looms. Loom) can be used.

In addition, the polyphenylene sulfide-based airbag fabric of the present invention may include a rubber coating layer on one or both sides of the fabric in order to lower the air permeability. The rubber component may be one or more selected from the group consisting of powder type silicone, liquid type silicone, polyurethane, and chloroprene rubber.

The coating amount per unit area of the rubber component may be used to 20 to 200 g / m ² , preferably 20 to 100 g / m ² . In particular, in the case of OPW (One Piece Woven) type side curtain airbag fabric, the coating amount is preferably 30 g / m ² to 95 g / m ² , and in the case of plain weave fabric for air bag, the coating amount is 20 g / m ² to 50 g / m ² levels are preferred.

Fabric for airbags of the present invention has a tensile strength of 170 to 350 kgf / inch, preferably 182 to 320 kgf / inch measured by the American Society for Testing and Materials (ASTM D 5034-GRAB method). In the case of the tensile strength, the tensile strength at room temperature should be 182 kgf / inch or more, and the tensile strength after aging (cycle, heat, humidity) should be 159 kgf / inch or more.

In addition, the airbag fabric is required to have an excellent tear strength level because it is rapidly inflated by a high-temperature gas, the tear strength indicating the burst strength of the airbag fabric is the American Material Testing Association standard (ASTM D 2261-TONGUE) When measured by the method) may be a value of 15 to 60 kgf / inch, preferably 23 to 45 kgf / inch. Below 15 kgf / inch, airbag rupture may occur during deployment of the airbag, which can pose a significant risk to airbag function.

Preferably, the airbag fabric of the present invention has an air permeability of 0.5 to 10.0 cfm measured at a pressure difference of 125 Pa using the American Society for Testing and Materials (ASTM D 737 method). It is not preferable in terms of maintaining the airtightness of the raw fabric.

In addition, the air bag fabric of the present invention preferably has a self-extinguishing level of 80 to 100% and a self extinguish of 0 to 80 mm / min according to the FMVSS 302 method. At this time, the burning length of the specimen taken in the inclined direction, weft direction and ± 45 ° direction in the fabric should be 80 mm or less and the average burning time should be 60 seconds or less.

Heat resistance of the fabric for airbag according to the present invention is evaluated according to the self-extinguishing or self-extinguishing rate. For 100 fabric samples taken from the fabric for airbags in the warp direction, the weft direction and the ± 45 ° direction, the exposure time was increased by using the FMVSS 302 method with a natural gas flame of 38 mm height or a heat source having an equivalent calorific value. In the case of seconds, the combustion length is 80 mm or less, and the combustion time is 60 seconds or less. The self-extinguishability (SE) is calculated. This is called. The autonomous rate is represented by the following formula (1).

[Equation 1]

% Of self-extinguishing ratio = (number of samples satisfying self-extinguishing) / (number of samples to be tested) x 100.

The present invention also comprises the steps of weaving the dough for airbags using the linear polyphenylene sulfide-based fiber comprising a repeating unit represented by the formula (1), the step of refining the woven airbag dough, and the refined fabric It provides a method for manufacturing an airbag fabric comprising the step of tentering.

The polyphenylene sulfide (PPS) -based airbag of the present invention is manufactured into a final airbag fabric through a conventional weaving method, a refining and heat setting process, and a silicone rubber coating process. The coated airbag fabric is manufactured in the form of an airbag cushion having a predetermined shape while cutting and sewing. The airbag is not limited to a particular type and can be manufactured in a general form.

In addition, the present invention provides an airbag system including the above airbag, and the airbag system may be provided with a conventional apparatus well known to those skilled in the art. The airbag can be broadly divided into a frontal airbag and a side curtain airbag. The frontal airbag includes a driver's seat, a passenger's seat, a side protection, a knee protection, an ankle protection, and a pedestrian protection airbag. The side curtain type airbag protects the passenger in the event of a side collision or an overturning accident. Therefore, the airbag of the present invention includes both the front airbag and the side curtain airbag.

The fabric for the airbag of the present invention weaving the fabric for the airbag using polyphenylene sulfide-based fibers, while ensuring the heat resistance and flame retardancy of significantly improved performance while minimizing the processing such as coating amount of the rubber component and polyurethane as the coating material and Excellent mechanical properties such as tensile strength and tear strength can be obtained.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example  One

Fabric dough for airbags was prepared through a rapier weaving machine using linear polyphenylene sulfide (PPS) yarns with a fineness of 420 deniers and a filament number of 68. At this time, in order to achieve the required air permeability, the weaving yarn and the warp yarn number were the same and weaved in plain weave.

The mixture was mixed with water so as to be 1.5 g / L of sodium hydroxide, 1.08 g / L of the surfactant, 1.08 g / L of the penetrating agent, and 1.25 g / L of the dispersant, and the mixture was divided into two chemical tanks and the temperature of each chemical tank was maintained at 75 캜 . In addition, two water baths each having a temperature of 80 캜 and 85 캜 were placed next to each chemical tank.

The raw paper for the airbag woven by the loom was firstly passed through the prepared chemical tank, then continuously passed through the two waterbaths, and then passed through the chemical tank and the two waterbaths.

The raw paper for the airbag which passed through the water washing tank was passed through a mangle and dehydrated, and then dried with hot air at 110 ° C to completely dry the residual moisture to prepare a fabric for an air bag.

Example  2

Fabrics for airbags were prepared in the same manner as in Example 1, except that the weaving density was woven at 55 / inch using linear polyphenylene sulfide (PPS) yarns having a fineness of 315 denier and a filament number of 105.

Example  3

A fabric for an airbag was prepared in the same manner as in Example 1, except that the weaving density was woven at 41 bones / inch using a linear polyphenylene sulfide (PPS) yarn having a fineness of 630 deniers and a filament number of 105.

Example  4

A fabric for airbags was prepared in the same manner as in Example 1, and the fabric was coated to have a coating amount of 20 g / m ² using a two-component liquid silicone rubber by a knife over method. .

Comparative Example  One

A fabric for airbags was prepared in the same manner as in Example 1, except that nylon 420 yarn of 420 denier was used.

Comparative Example  2

Except for using a nylon 66 yarn of 315 denier was prepared in the airbag fabric in the same manner as in Example 2.

Comparative Example  3

A fabric for an airbag was prepared in the same manner as in Example 3, except that 630 denier nylon 66 yarn was used.

Comparative Example  4

An airbag fabric was manufactured in the same manner as in Example 4 except that the fabric for airbag was manufactured in the same manner as in Comparative Example 1.

The physical properties of the airbag fabrics of Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated as follows.

 (a) Tensile strength: ASTM D 5034

The specimens were cut from the fabric for airbags and fixed to the lower clamp of a tensile strength measuring device according to American Society for Testing and Materials (ASTM) D 5034, and the strength of the airbag cushion specimen fracture was measured while moving the upper clamp upward.

 (b) Tear Strength: American Society for Testing and Materials Standards (ASTM) D 2261

After the specimens were cut from the airbag fabric, they were cut 7 cm in the warp or oblique direction, and the left and right fabrics of the incision were attached to the grommet of the tear tester. The fabric was ruptured while crossing the clamps up and down while the fabric was mounted, and the strength was measured.

(c) Air permeability: American Society for Testing and Materials (ASTM) D 1338

After leaving the fabric for airbags at 20 ° C. and 65% RH for at least one day, the amount of air passing through a circular cross section of 38 cm ² was measured at a pressure of 125 Pa.

(d) Heat resistance and flame retardancy (autonomous rate): evaluation method of FMVSS 302

100 samples of 100mm x 355mm size were randomly taken from the fabric for airbags, and the heat resistance was evaluated by using the FMVSS 302 method with a natural gas flame having a height of 38mm or a heat source having an equivalent calorific value of 15 seconds. It was implementation.

When the prepared sample is exposed to the heat source and the heat source is removed after 15 seconds, the burned sample has a length of 80 mm or less and is turned off within 60 seconds, called self-extinguishing (SE). The self-permeability was measured by calculating the number of samples satisfying the digestibility criteria in%, and the self-permeability was calculated according to Formula 1.

The measurement results for the airbag fabric of Examples 1 to 4 and Comparative Examples 1 to 4 are shown in Table 1 below.

division The tensile strength
(kgf / inch) Phosphorus strength
(kgf) Air permeability
(cfm) Autonomy
(%) Self-baking Example 1 265 43 2.2 100 SE Example 2 240 39 3.0 100 SE Example 3 315 52 1.7 100 SE Example 4 268 47 0.5 100 SE Comparative Example 1 256 40 2.1 83 - Comparative Example 2 235 36 2.9 88 - Comparative Example 3 310 48 1.8 85 - Comparative Example 4 257 43 0.5 93 -

As shown in Table 1, the airbag fabric of Examples 1 to 4 using the linear polyphenylene sulfide-based fiber has excellent performance in tensile strength and tear strength, etc. compared to the fabric using nylon 66 yarn of Comparative Examples 1 and 2 It can be seen that having.

In particular, in the case of the airbag fabrics of Examples 1 to 4 using polyphenylene sulfide-based fibers, all samples 100 exhibit self extinguish (SE), and the self-permeability is remarkably improved to provide excellent heat resistance. And it can be confirmed that it has flame retardancy.

The present invention can manufacture an airbag fabric using a linear polyphenylene sulfide-based fiber, thereby improving the mechanical properties such as tensile strength and tear strength, and can provide an excellent airbag system with significantly improved heat resistance and flame resistance. .

Claims (8)

To include a linear polyphenylene sulfide-based fiber comprising a repeating unit represented by the formula (1), The fabric is an air bag fabric having an atomic ratio of 80 to 100%, a combustion length of 80 mm or less, and an average combustion time of 60 seconds or less, as measured by the heat resistance evaluation method FMVSS 302. [Formula 1]

The method of claim 1, The polyphenylene sulfide-based fiber has a fineness of 210 to 840 denier, filament number of 60 to 500, tensile strength of 4.5 to 12.5 g / d, heat shrinkage of 3% or less fabric. The method of claim 1, The fabric is an airbag fabric coated with at least one rubber component selected from the group consisting of powder type silicone, liquid type silicone, polyurethane, and chloroprene rubber. The method of claim 3, And a coating amount of the rubber component per unit area of 20 to 200 g / m ² . The method of claim 1, The fabric is an airbag fabric having a tensile strength of 170 to 350 kgf / inch measured by the American Society for Testing and Materials (ASTM D 5034-GRAB) method. The method of claim 1, The fabric is an airbag fabric having a tear strength of 15 to 60 kgf measured by the American Society for Testing and Materials (ASTM D 2261-TONGUE) method. The method of claim 1, The fabric is an airbag fabric having an air permeability of 0.5 to 10.0 cfm measured by the American Society for Testing and Materials Standard (ASTM D 737) method. delete