KR101130264B1 - Airbag Fabrics Using Polyethyleneterephtalate Yarn having Heat Resistance - Google Patents

Abstract

The present invention relates to a fabric for airbags using polyethylene terephthalate fiber, specifically, to adjust the strength and elongation of polyethylene terephthalate fiber to produce polyethylene terephthalate fiber for airbags and heat resistance and instantaneous thermal strain produced using the same This improved airbag fabric. The present invention relates to an airbag fabric comprising polyethylene terephthalate fibers prepared by spinning polyethylene terephthalate chips having an intrinsic viscosity of 0.8 to 1.3 dl / g, wherein the fabric for airbags is measured at It provides a fabric for an air bag, characterized in that the heat resistance of 0.75 to 1.0 seconds.

Description

Airbag Fabrics Using Polyethyleneterephtalate Yarn having Heat Resistance

The present invention relates to a fabric for airbags using polyethylene terephthalate fiber, specifically, to control the strength and elongation of polyethylene terephthalate fiber to replace the existing airbag fabric using nylon 66 yarn polyethylene tere for airbags The present invention relates to a fabric for an airbag having improved phthalate fiber and improved heat resistance and instantaneous thermal strain.

Airbags require low breathability in order to deploy smoothly in a crash, and high energy absorption capacity is required to prevent damage and rupture of the airbag itself. In addition, properties such as the foldability of the fabric itself is required to improve the storage. Nylon 66 material has been mainly used as a suitable fiber for this property required in airbag fabrics. Recently, however, interest in fiber materials other than nylon 66 has been increasing for cost reduction.

Polyethyleneterephthalate is a fiber that can be used as an airbag. When polyethylene terephthalate is used as the yarn for the airbag, there is a problem that seams are torn in the airbag cushion module experiment. In order to solve this problem, it is important to use polyethylene terephthalate yarn which does not lower the energy absorption capacity of the polyethylene terephthalate airbag. In addition, in the fabric for airbags using polyethylene terephthalate yarn, it is necessary to improve the flexibility for ease of storage.

In the present invention, in order to solve the above problems, the energy absorption capacity is excellent, the burst phenomenon of the edge portion of the sewing portion in the airbag cushion development experiment is improved, and manufacturing an airbag fabric using polyethylene terephthalate which can improve the storage capacity of the airbag fabric It aims to do it.

In order to solve the above problems, according to a preferred embodiment of the present invention, in the airbag fabric comprising polyethylene terephthalate fiber produced by spinning a polyethylene terephthalate chip having an intrinsic viscosity of 0.8 ~ 1.3dl / g, The fabric for airbags has a thermal resistance of 0.75 to 1.0 second at 350 ° C. calculated by the following equation, and the polyethylene terephthalate fiber provides an airbag fabric which is characterized by an instantaneous thermal strain of 1.0 to 5.0%.

[Equation 1]

Heat resistance of the fabric (seconds) = T ₁ -T ₂

In the above formula, T ₁ is the time when the steel rod heated to 350 ° C. at the height of 10 cm above the fabric falls through the fabric, and T ₂ is the time when the same steel rod falls from the same height.

According to another suitable embodiment of the present invention, the polyethylene terephthalate fiber provides an air bag fabric, characterized in that the strength at room temperature is 8.0 to 11.0g / d, elongation is 15% to 30%.

According to another suitable embodiment of the present invention, the polyethylene terephthalate fiber provides a fabric for an air bag, characterized in that the single yarn fineness is 4.5 denier or less.

Polyethylene terephthalate airbag fabric produced in the present invention improved the lack of flexibility and heat resistance of the disadvantages of conventional airbag fabric. As a result, in the airbag deployment test of the airbag module using the airbag fabric, it is possible to provide a fabric for the airbag that does not burst instantly due to a high temperature expansion gas.

The present invention adjusts the strength and elongation of polyethylene terephthalate fiber produced by spinning a polyethylene terephthalate chip having an intrinsic viscosity of 0.8 ~ 1.3 dl / g to produce a polyethylene terephthalate fiber for airbags, using the heat resistance and instantaneous By manufacturing a fabric for airbags having excellent thermal strain, the fabric for airbags is improved in that the edge portion is bursted so as not to burst in the airbag cushion deployment test.

In the present invention, polyethylene terephthalate obtained by spinning a polyethylene terephthalate chip having an intrinsic viscosity (IV) of 0.8 to 1.3 dl / g in order to safely absorb the instantaneous impact energy of the exhaust gas generated by the explosives inside the air bag. Use multifilament. Polyester yarns having IVs with an inherent viscosity of less than 0.8 dl / g are not suitable because they do not have sufficient toughness to be used as air bags.

Resin for producing synthetic fiber multifilament for airbag of the present invention is polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene-1,2-bis (phenoxy) ethane-4 Copolymers comprising, 4'-dicarboxylate, poly (1,4-cyclohexylene-dimethylene terephthalate) and at least one repeating unit of the polymer, for example polyethylene terephthalate / isophthalate copoly Esters, polybutylene terephthalate / naphthalate copolyesters, polybutylene terephthalate / decanedicarboxylate copolyesters, and mixtures of two or more of the foregoing polymers and copolymers. Among them, in the present invention, polyethylene terephthalate resin is particularly preferable in terms of mechanical properties and fiber formation.

Polyethylene terephthalate fiber for airbags of the present invention is 8.0 to 11.0g / d at room temperature, it is preferable that the elongation is 15 to 30%.

When the strength of the polyethylene terephthalate fiber for airbags of the present invention is less than 8.0g / d, the tensile strength and tear strength of the woven airbag fabric is low and is not suitable.

In addition, when the elongation of the fiber is less than 15%, when the airbag cushion is suddenly inflated, the energy absorbing ability decreases and the cushion is broken, making the cushion unsuitable. It is difficult to apply the application.

It is preferable that single yarn fineness is 4.5 denier or less, and, as for the polyethylene terephthalate fiber for airbags of this invention, it is more preferable that it is 3 denier or less. Usually, the more the fiber of a single yarn fineness is used, the softer the woven fabric will be, the more excellent the foldability and the better the storage performance. Moreover, single yarn fineness becomes small, and covering property improves, As a result, the air permeability of a woven fabric can be suppressed. If the single yarn fineness exceeds 4.5 deniers, the foldability and the storage performance of the fabric are deteriorated and the low air permeability is deteriorated, and thus, the airbag fabric does not have a sufficient function.

It is preferable that the instantaneous thermal strain in the polyethylene terephthalate fiber for airbags of this invention is 1.0 to 5.0% at 100 degreeC, More preferably, the instantaneous thermal strain is 2.0 to 4.0%. If the instantaneous thermal strain of the fiber is less than 1.0%, the energy absorbing capacity applied when the airbag cushion is inflated by the hot gas is poor, and the airbag cushion is likely to burst. In addition, when the instantaneous thermal strain of the fiber exceeds 5.0%, the increase in the length of the fiber at a high temperature causes a problem of uncontrolled expansion gas leakage due to the opening of the bar when the airbag cushion is inflated by the hot gas.

The hot rod test measured using a rod heated at 350 ° C. for uncoated polyethylene terephthalate fabrics of 50 wt. Do. If the heat resistance measured at 350 ° C. is less than 0.75 seconds, the heat resistance of the fabric for the airbag becomes too low, so that the airbag cushion does not endure high temperature gas and the sewing part of the edge is easily broken. When the heat resistance measured at 350 ° C. exceeds 1.0 second, a higher fineness polyethylene terephthalate yarn should be used, which increases the rigidity of the fabric, resulting in deterioration of module storage capacity of the airbag fabric.

In the present invention, when weaving a woven fabric with polyethylene terephthalate fiber, it is preferable to weave a plain weave having a symmetrical structure, but to obtain a woven fabric having better physical properties, it is optional to use a yarn having a thinner linear density. You can also weave in Panama.

Woven fabrics can be used by coating at 15 to 60 g / m ² weight using a coating agent selected from silicon, polyurethane, acrylic, neoprene and chloroprene to ensure low breathability suitable for airbag fabrics.

The physical property evaluation of an Example and a comparative example was measured or evaluated as follows.

1) Intrinsic viscosity (I.V.)

After dissolving 0.1 g of the sample in a reagent (90 ° C.) mixed with phenol and 1,1,2,2-tetrachloroethanol 6: 4 (weight ratio) for 90 minutes, transfer to a Ubbelohde viscometer and place it in a 30 ° C. thermostat. The solution is held for 10 minutes at, and the drop seconds of the solution are obtained by using a viscometer and an aspirator. The number of seconds of falling of the solvent can also be obtained by the following equations obtained from the above equations. The value was calculated.

R.V. = Number of drops of solvent / number of drops of solvent

I.V. = 1/4 × [(R.V.-1) / C] + 3/4 × (In R.V./C)

In the formula, C represents the concentration (g / 100ml) of the sample in solution.

2) Instantaneous thermal strain measurement

Randomly selected from multifilament yarns are made into bundles having about 59 denier.

The filament bundle is mounted on a thermomechanical analyzer (TA Instruments, model TMA Q-400) to a length of 10 mm and subjected to a stress of 1.0 gf / den. The test is started 2 minutes after the stress is applied and the temperature is rapidly raised to heat for 30 seconds from 30 ° C to 100 ° C. The instantaneous thermal strain is expressed as a percentage by dividing the increase in sample length when the temperature reaches 100 ° C. by the initial sample length.

3) Hot rod test

When a cylindrical steel rod weighing 50g and a diameter of 10mm is heated to 350 ° C and dropped vertically from the height of 10cm above the airbag fabric, the time T ₁ during which the heated rod falls through the fabric and falls down is measured. The time T ₂ during which the bar falls without it is measured, and the thermal resistance is measured by the following formula. At this time, airbag fabric is measured for 1 layer without grounding.

[Equation 1]

Fabric thermal resistance (sec.) = T ₁ -T ₂

4) How to measure the elongation of yarn

After leaving the yarn in a standard condition, that is, a constant temperature and humidity chamber at a temperature of 25 ° C. and a relative humidity of 65% for 24 hours, the sample is measured by a tensile tester using the ASTM 2256 method.

5) weaving and coating of fabrics

The filament yarns are woven into plain weave at 50 × 50 yarn densities per inch in both warp and weft directions. The dough is refined and shrunk in an aqueous bath set in stages from 50 ° C. to 95 ° C. in a continuous refiner and heat set at 200 ° C. for 2 minutes. And it was coated with a weight of 25g / m ² using a silicone coating agent.

9) Deployment test of airbag cushion

After making the module with airbag fabric and leaving it at 85 ℃ for 4 hours, the development test was conducted within 3 minutes to observe the burst and evaluated PASS and FAIL.

Hereinafter, the present invention will be described in detail with reference to Examples, but the scope of the present invention is not limited or limited by the following Examples and Comparative Examples.

Example 1

Fabrics for airbags were prepared by using a polyethylene terephthalate yarn having the properties described in Table 1 below to make a fabric density of 50 × 50 fabrics per inch in both warp and weft directions with a rapier loom.

Example 2

In the same manner as in Example 1 with a polyethylene terephthalate yarn having the properties shown in Table 1 was prepared for airbag dough.

Example 3

In the same manner as in Example 1 with a polyethylene terephthalate yarn having the properties shown in Table 1 was prepared for airbag dough.

Comparative Example 1

Fabrics for airbags were prepared by weaving nylon 66 yarns having the properties listed in Table 1 below so that the fabric density was 50 × 50 fabrics per inch in both warp and weft directions with a rapier loom.

Comparative Example 2

In the same manner as in Comparative Example 1 with a polyethylene terephthalate yarn having the properties described in Table 1 was prepared for airbag dough.

Comparative Example 3

In the same manner as in Comparative Example 1 with a polyethylene terephthalate yarn having the properties described in Table 1 was prepared for airbag dough.

Example 4

The raw paper prepared in Example 1 was passed through an aqueous bath set in steps of 50 ° C. to 95 ° C. to refine and heat shrink the dough, and then heat fixed at 200 ° C. for 2 minutes to prepare 350 ° C. of the uncoated fabric. The thermal resistance at is measured and shown in Table 2 below. Table 2 also shows the results of the airbag cushion development test evaluated by making an airbag cushion with a coated fabric heat-treated at 180 ° C. for 2 minutes after coating a 25g / m ² silicon-based coating agent on the fabric.

Example 5

The physical properties and airbag cushion development test results of the fabric prepared by treating the dough prepared in Example 2 in the same manner as in Example 4 are shown in Table 2 below.

Example 6

The physical properties and airbag cushion development test results of the fabrics prepared by treating the dough prepared in Example 3 in the same manner as in Example 4 are shown in Table 2 below.

Comparative Example 4

The dough prepared in Comparative Example 1 was passed through an aqueous bath set in steps of 50 ° C. to 95 ° C. to refine and heat shrink the dough, and heat treated at 200 ° C. for 2 minutes to 350 ° C. The thermal resistance at is measured and shown in Table 2 below. Table 2 also shows the results of the airbag cushion development test evaluated by making an airbag cushion with a coated fabric heat-treated at 180 ° C. for 2 minutes after coating a 25g / m ² silicon-based coating agent on the fabric.

Comparative Example 5

The dough prepared in Comparative Example 2 was treated in the same manner as in Comparative Example 4. The physical properties and airbag cushion development test results of the fabrics are shown in Table 2 below.

Comparative Example 6

The dough prepared in Comparative Example 3 was treated in the same manner as in Comparative Example 4. The physical properties and airbag cushion development test results of the fabrics are shown in Table 2 below.

division Material Dead species Intrinsic viscosity
(dl / g) Single Sand Island (den) Strength (g / den) Shindo
(%) Momentary heat
% Strain Example 1 Polyethylene terephthalate 500d / 182f 1.06 2.7 8.4 25.0 2.8 Example 2 Polyethylene terephthalate 500d / 182f 1.06 2.7 11.0 18.0 3.5 Example 3 Polyethylene terephthalate 500d / 120f 1.06 4.2 9.0 22.6 2.3 Comparative Example 1 Nylon66 420d / 68f - 6.2 9.7 22.0 1.8 Comparative Example 2 Polyethylene terephthalate 420d / 68f 1.06 6.2 7.8 14.0 0.4 Comparative Example 3 Polyethylene terephthalate 500d / 96f 1.06 5.2 7.5 12.0 0.6

division 350 ℃ heat resistance
(sec.) Airbag cushion
Deployment test Example 4 0.94 PASS Example 5 0.97 PASS Example 6 0.87 PASS Comparative Example 4 0.79 PASS Comparative Example 5 0.69 FAIL Comparative Example 6 0.73 FAIL

Claims (3)

In the airbag fabric containing polyethylene terephthalate fiber prepared by spinning a polyethylene terephthalate chip having an intrinsic viscosity of 0.8 ~ 1.3,
The airbag fabric has a thermal resistance of 0.75 to 1.0 second at 350 ° C. calculated by the following equation,
The polyethylene terephthalate fiber is an airbag fabric, characterized in that the instantaneous thermal strain is 1.0 to 5.0%.
[Formula 1]
Heat resistance of the fabric (seconds) = T ₁ -T ₂
(In the above formula, T ₁ is the time when the steel rod heated at 350 ° C. at the height of 10 cm above the fabric falls through the fabric, and T ₂ is the time when the same steel rod falls from the same height.) The method according to claim 1,
The polyethylene terephthalate fiber has a strength at room temperature of 8.0g / d to 11.0g / d, the elongation is 15% to 30% fabric for airbags, characterized in that. The method according to claim 1,
The polyethylene terephthalate fiber is an airbag fabric, characterized in that the single yarn fineness is 4.5 denier or less.