KR20110076140A - Polyethyleneterephthalate fiber for air bag and fabric using the same - Google Patents

Abstract

PURPOSE: A polyethylene terephthalate fiber for airbag and a fabric using the same are provided to improve bursting phenomenon of an edge sealing part not to make the airbag fabric burst at the airbag cushion reverse flatting test. CONSTITUTION: The polyethylene terephthalate multifilament for airbag is manufactured by spinning a polyethylene terephthalate chip having an inherent viscosity of 0.8~1.3. The polyethylene terephthalate multifilament for airbag is extended to less than 4% under the initial stress of 1.0g /d, at the room temperature and is extended to less than 12% under the stress of 4.5g /d. The polyethylene terephthalate multifilament contains terminal carboxyl group (CEG) less than 35mmol / kg and has a mono denier less than 5 denier.

Description

Polyethylene terephthalate fiber for air bag and fabric using the same

The present invention relates to polyethylene terephthalate fibers for airbags and fabrics for airbags using the same, in particular, to control the force-strain curve of polyethylene terephthalate multifilament produced by spinning polyethylene terephthalate chip having an intrinsic viscosity of 0.8 to 1.3 The present invention provides an airbag fabric having improved edge rupture phenomenon by applying to an airbag fabric so as not to burst in an airbag cushion deployment test.

Airbag fabrics require various characteristics such as low breathability for smooth deployment in a crash, high energy absorption to prevent damage and rupture of the airbag itself, and foldability of the fabric itself to improve storage. Nylon 66 material has been mainly used as a fiber suitable for the required characteristics of the airbag fabric, but recently, interest in fiber materials other than nylon 66 is increasing for economic reasons such as cost reduction.

In order to use polyethylene terephthalate yarn in airbags, it is necessary to solve the problem of popping up in the airbag cushion module development test.Efforts to improve the energy absorption performance of polyethylene terephthalate airbags and to prevent the airbag edge bar from bursting during airbag inflation Efforts are being made.

An object of the present invention is to improve the phenomenon that the edge portion of the fabric is bursting so that the fabric for airbags using polyethylene terephthalate fiber does not burst in the airbag cushion development test, for this purpose by adjusting the force-strain curve of the polyethylene terephthalate multifilament The terephthalate multifilament stretches less than 4% when subjected to an initial stress of 1.0 g / d at room temperature, and less than 12% when subjected to medium stresses of 4.5 g / d, from a tensile strength of at least 7.0 g / d. It has a force-strain curve that stretches by 3% or more until the fiber is cut, the elongation at break is 15% or more, the F / F static friction factor of the yarn divided by the F / M static friction factor is 1.5 or more, and the terminal carboxyl group ( CEG) provides polyethylene terephthalate multifilament having a content of 35mmol / kg or less and single yarn fineness of 5 denier or less, and providing a fabric for an air bag using the same And that is the purpose.

In order to solve the above problems, according to a preferred embodiment of the present invention, in the polyethylene terephthalate multifilament for airbags produced by spinning a polyethylene terephthalate chip having an intrinsic viscosity of 0.8 to 1.3, 1.0 g / d at room temperature Elongation less than 4% when subjected to initial stress, less than 12% when subjected to medium stress of 4.5 g / d, and elongation greater than 3% until the fiber is cut from a tensile strength of at least 7.0 g / d. Polyethylene terephthalate for airbags having a strain curve, having an elongation at least 15%, a F / F static friction coefficient divided by F / M static friction coefficient of 1.5 or more, and a single yarn fineness of 5 denier or less. Provides multifilament.

According to another suitable embodiment of the present invention, the polyethylene terephthalate multifilament provides a polyethylene terephthalate multifilament for an air bag, characterized in that the total fineness of 150 to 1000 denier.

According to another suitable embodiment of the present invention, the polyethylene terephthalate multifilament provides a polyethylene terephthalate multifilament for an air bag, characterized in that the terminal carboxyl group (CEG) content is 35mmol / kg or less.

According to another suitable embodiment of the present invention, there is provided a fabric for an air bag woven using the polyethylene terephthalate multifilament.

According to another suitable embodiment of the present invention, the airbag fabric is prepared by coating with a weight of 15 ~ 60g / m ² using one coating agent selected from the group consisting of silicone, polyurethane, acrylic, neoprene and chloroprene. (1) tensile strength of 190 to 300kgf, (2) tear strength of 25 to 40kgf, (3) air permeability 0.5 CFM (Cubic Feet per Minute) provides a coating fabric for air bags.

The present invention adjusts the force-strain curve of the polyethylene terephthalate fiber, the polyethylene terephthalate multifilament is stretched to less than 4% when subjected to the initial stress of 1.0 g / d at room temperature, subjected to medium-stress of 4.5 g / d Has a force-strain curve that extends less than 12% when pulled, stretches at least 3% from a tensile strength of at least 7.0 g / d until the fiber is cut, elongation at break is 15% or more, and F / F static friction coefficient of yarn Rupture of edge part in airbag cushion development test by using polyethylene terephthalate filament with F = M divided by F / M static friction coefficient of 1.5 or more, terminal carboxyl group (CEG) content of 35 mmol / kg or less, and single yarn fineness of 5 denier or less This improved fabric for airbags can be produced.

The present invention adjusts the force-strain curve of polyethylene terephthalate multifilament produced by spinning polyethylene terephthalate chip having an intrinsic viscosity of 0.8 to 1.3, and applies it to an airbag fabric so that the edge portion of the edge is not broken in the airbag cushion development test. To provide a fabric for the air bag improved the phenomenon.

The present invention provides a polyethylene terephthalate multifilament obtained by spinning a polyethylene terephthalate chip having an intrinsic viscosity of 0.8 to 1.3 in order to safely absorb the instantaneous impact energy of the exhaust gas generated by the explosives inside the air bag. use. Polyester yarns having an intrinsic viscosity of less than 0.8 dl / g are not suitable because they do not provide yarns with sufficient toughness.

Resin for producing the multi-filament for the air bag of the present invention, in addition to polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene-1,2-bis (phenoxy) ethane-4,4 Copolymers comprising '-dicarboxylate, poly (1,4-cyclohexylene-dimethylene terephthalate) and at least one repeating unit of the polymer, for example polyethylene terephthalate / isophthalate copolyester, Polybutylene terephthalate / naphthalate copolyester, polybutylene terephthalate / decanedicarboxylate copolyester, and mixtures of two or more of the above polymers and copolymers. Among them, in the present invention, polyethylene terephthalate resin is particularly preferable in terms of mechanical properties and fiber formation.

It is preferable that the terminal carboxyl group (CEG) content of the polyethylene terephthalate fiber of this invention is 35 mmol / kg or less. When the terminal carboxyl group (CEG) content of polyethylene terephthalate yarn exceeds 35mmol / kg, the hydrolysis performance of the yarn is lowered, making it difficult to maintain the performance of the airbag fabric under high temperature and high humidity conditions.

Fibers suitable for the polyethylene terephthalate multifilament for airbags of the present invention are preferred to elongate less than 4% when the force-strain curve is subjected to an initial stress of 1.0 g / d. Elongation of more than% may cause the fabric to be damaged early due to rapid deformation of the fabric.

In addition, in the present invention, when subjected to the medium-term stress of 4.5g / d, it is preferable to extend less than 12% of yarn, which extends more than 12% to the medium-term stress of 4.5g / d, the ventilation of the fabric is rapidly increased to exhaust gas It causes burns in the human body.

In addition, in the present invention, it is preferable that the fabric using polyethylene terephthalate yarn is stretched by 3% or more until the yarn is cut from a tensile strength of at least 7.0 g / d to have a tensile strength and tear strength suitable for use as an air bag. If the yarn is stretched less than 3% from the tensile strength of at least 7.0 g / d until the yarn is cut, there is a problem in that the tensile strength and tear strength are insufficient when weaving a low-weight fabric because the yarn lacks the maximum tensile load absorption.

The cutting elongation of the polyethylene terephthalate multifilament for airbags of the present invention is 15% or more, but when the cutting elongation is less than 15%, the energy absorbing capacity of the airbag cushion is suddenly inflated, which causes the cushion to burst and is not suitable. .

It is preferable that the total fineness of the polyethylene terephthalate multifilament for airbags of this invention is 150-1000 denier, More preferably, it is 200-700 denier. If the total fineness is less than 150 denier yarns, the fabric for airbags is satisfactory in terms of storage, but it is not preferable because the bag lacks strength and may cause the bag to rupture during deployment and after a passenger collision. On the contrary, when the total fineness exceeds 1000 denier, sufficient strength is obtained as an air bag and satisfactory in terms of safety, but the fabric becomes thicker and the storage capacity becomes worse.

About single yarn fineness of the multifilament which comprises the fabric for airbags, it is preferable that it is 5 denier or less, More preferably, it is 4.5 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 5 denier, it is not preferable because it does not exert sufficient function as an airbag fabric with deterioration of the foldability and storage property of the fabric and also deterioration of low breathability.

In the present invention, the F / F friction coefficient relative ratio value refers to a value obtained by dividing the fiber-to-metal static friction coefficient F / F μs of polyethylene terephthalate yarn by the fiber / metal intermetallic friction coefficient F / M μs. It is preferable that the F / F friction coefficient relative ratio value is 1.5 or more, and more preferably, a yarn having a characteristic of 2.0 or more is suitable as a fabric for an air bag. If the F / F friction coefficient relative ratio value is less than 1.5, it is not preferable because the interfiber friction coefficient is insufficient and the bar part of the edge part is increased in the airbag cushion development test.

In order to sufficiently increase the F / F friction coefficient relative ratio value to 1.5 or more, it is important to select an appropriate spinning oil. The type of spinning oil may be either an emulsion type or a solvent type, but it is preferable to use an oil having a relatively high F / F friction coefficient as compared to the F / M friction coefficient. In the embodiment of the present invention, a polyethylene terephthalate yarn for airbags was prepared by spinning the spinning oil selected from the emulsion type spinning oil with OPU 0.6% adhesion.

The polyethylene terephthalate fiber produced by the manufacturing method of the present invention can use an air jet or a water jet loom, but since the residual oil content of the fabric is preferably 0.1% by weight or less, the dropping property of the oil adhered to the fiber In consideration of this, it is preferable to weave water jet rooms. Furthermore, after weaving, it is preferable to perform refining treatment and hot set treatment at 160 to 190 캜.

When weaving the woven fabric with the polyethylene terephthalate fiber produced by the manufacturing method of the present invention, it is preferable to weave a plain woven fabric having a symmetrical structure. You can also weave in Panama.

The woven fabric may be coated with a weight of 15 to 60 g / m ² using a coating agent selected from silicone, polyurethane, acrylic, neoprene and chloroprene to ensure low breathability suitable for airbag fabrics.

In the present invention, the physical properties of Examples and Comparative Examples were 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) Measurement of terminal carboxyl group (CEG) content of yarn

The terminal carboxyl group content is analyzed by GRI (Geosynthetic Research Institute) Test Method "GG7" method and expressed in mmol / kg units.

3) 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.

4) Friction fastness of yarn

Using a friction tester (model YF-850) manufactured by TORAY, the static friction coefficient F / F μs between fibers was measured by rubbing yarns at a speed of 3 cm / min, and the static friction coefficient F / M μs between fibers and metal was measured. The Ni coated metal was measured by rubbing the yarn at 200 m / min. The relative ratio of F / F friction coefficient was calculated by dividing F / F μs by F / M μs.

5) Tensile strength of fabric

Using Instron 4465 (manufactured by Instron, USA), the fabric is allowed to stand at 10 cm wide and 15 cm long after being left for 24 hours under standard conditions (20 ° C, 65 relative humidity) according to ASTM D 5034. Tensile strength of was measured.

6) Tear strength of fabric

Tear steel of fabric using Instron 4465 (manufactured by Instron, USA) for at least 24 hours under standard conditions (20 ° C, 65 relative humidity) according to the tongue method according to ASDM D 2261. The degree was measured.

7) Air permeability of fabric

Using a Frazier air permeability meter, the air permeability of the fabric was measured under 125 Pa pressure according to the ASDM 737 method.

8) 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.

Example 1

Dough for airbags was prepared by using a polyethylene terephthalate yarn of the properties shown in Table 1 to be 50 × 50 fabrics per inch with a waterjet loom. At this time, the spinning oil used was selected from the emulsion type spinning oil of Takemoto Co., Ltd., which had a relatively high F / F friction coefficient (product name: TNX-021) and spun with an OPU 0.6% adhesion amount.

Comparative Example 1

Dough for airbags was prepared in the same manner as in Example 1 using polyethylene terephthalate yarns having the properties shown in Table 1.

At this time, the spinning oil used was selected to have a relatively low F / F coefficient of friction (Product Name: TN-0071T) among the Croda-wool's solvent type spinning oil, and was spun with 0.6% OPU adhesion.

Example 2

The dough prepared in Example 1 was refined and thermally contracted by passing through a 95 ° C. aqueous bath, and then heat-fixed at 185 ° C. for 2 minutes. And coating with a weight of 25g / m ² using a silicone coating agent to prepare a coating fabric for air bags. Evaluation of the physical properties of the fabric thus prepared and the airbag cushion development test results are shown in Table 2 below.

Comparative Example 2

Evaluation of the physical properties of the fabric produced by treating the dough prepared in Comparative Example 1 in the same manner as in Example 2 and airbag cushion development test results are shown in Table 2 below.

TABLE 1

division standard cinnabar
Island Strength (g / den) Shindo
(%) F / F friction coefficient
Relative costs % Elongation at 1.0 g / d % Elongation at 4.5 g / d % Elongation from 7.0 g / d to cutting CEG content
(mmol / kg) Example 1 500d / 120f 4.2 9.0 22.6 3.16 0.9 9.7 5.1 25.4 Comparative Example 1 500d / 120f 4.1 9.1 20.3 1.43 0.9 9.8 5.3 25.2

TABLE 2

division The tensile strength
(Slope X weft, kgf) Phosphorus strength
(Slope X weft, kgf) Air permeability
(CFM) Airbag cushion
Deployment test Example 2 223 × 221 27.3 × 27.7 0.1 or less PASS Comparative Example 2 219 × 215 27.0 × 28.6 0.1 or less FAIL

Claims (5)

Polyethylene terephthalate multifilament for airbags produced by spinning polyethylene terephthalate chips having an intrinsic viscosity of 0.8 to 1.3. Under medium stress, it has less than 12% elongation, and has a force-strain curve that elongates at least 3% until the fiber is cut from a tensile strength of at least 7.0 g / d. A polyethylene terephthalate multifilament for airbags, wherein the value of F static friction divided by F / M static friction is 1.5 or more and single yarn fineness is 5 denier or less. The polyethylene terephthalate multifilament of claim 1, wherein the polyethylene terephthalate multifilament has a total fineness of 150 to 1000 deniers. The polyethylene terephthalate multifilament of claim 1, wherein the polyethylene terephthalate multifilament has a terminal carboxyl group (CEG) content of 35 mmol / kg or less. An airbag fabric woven using the polyethylene terephthalate multifilament of claim 1. The airbag fabric of claim 4 is manufactured by coating at 15 to 60 g / m ² weight using one coating agent selected from the group consisting of silicone, polyurethane, acrylic, neoprene and chloroprene, and satisfying the following physical properties. Coated fabric: (1) tensile strength 190 to 300kgf, (2) tear strength 25 to 40kgf, (3) air permeability 0.5 CFM (Cubic Feet per Minute) or less