KR20120029957A - Polyester fabrics and preparation method thereof - Google Patents

Abstract

PURPOSE: Polyester fiber capable of using for airbag fabric is provided to have excellent acceptability, shape stability and air blocking ability, thereby minimizing the impact to passenger and protecting passengers safely. CONSTITUTION: Polyester fiber comprises polyester yarn with the fineness 400-650 denier. The anti-slip index(EIwa) in equation 1(EIwa= ERwa/[(weft density + warp density) × D1/2]) measured after heat treatment under the condition of 85°C and 65 %RH for 4 hours is 0.15-0.38. In equation 1, ERwa is anti-slip index(N) along weft direction measures by ASTM D 6479 method, and D is the fineness of the polyester yarn(De). The polyester fiber is coated by powder type silicon, liquid type silicon, chloroprene, neoprene rubber or emulsion type silicon resin. The manufacturing method of polyester fiber comprises a step of weaving fabric for an airbag; a step of refining the fabric; and a step of tentering the fabric.

Description

Polyester fabric and manufacturing method thereof {POLYESTER FABRICS AND PREPARATION METHOD THEREOF}

The present invention relates to a fabric for airbags and a method for manufacturing the same, and more particularly, a polyester fabric having excellent toughness and energy absorption performance, including a low modulus and a high strength and high elongation polyester yarn, and a method for manufacturing the same It relates to a vehicle airbag.

In general, 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 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, the airbags used in automobiles are manufactured in a certain form, and then folded in order to minimize the volume of the airbags. Allow it to expand and deploy.

Therefore, in order to effectively maintain the folding and packageability of the airbag when installing the vehicle, to prevent damage and rupture of the airbag itself, to exhibit excellent airbag cushion deployment performance, and to minimize the impact on passengers, the airbag fabric has excellent mechanical properties. In addition, foldability and flexibility to reduce the impact on passengers is very important. However, airbag fabrics that maintain excellent air blocking effect and flexibility at the same time for the safety of passengers, sufficiently endure the impact of airbags and can be effectively mounted in a vehicle have not been proposed.

Conventionally, polyamide fibers such as nylon 66 have been used as a material for yarn for airbags. However, nylon 66 is excellent in impact resistance, but inferior in terms of moisture resistance, light resistance, shape stability and high raw material cost compared to polyester fiber.

On the other hand, Japanese Patent Application Laid-Open No. 04-214437 proposes the use of polyester fibers in which such defects are alleviated. However, in the case of manufacturing air bags using conventional polyester yarns, it is difficult to store them in a narrow space when mounted in a vehicle due to high stiffness, and excessive heat shrinkage occurs at high temperature heat treatment due to high elasticity and low elongation. In addition, there have been limitations in maintaining sufficient mechanical properties and development performance under the harsh conditions of high temperature and high humidity.

Therefore, it is a textile fabric that maintains excellent mechanical properties and air blocking effect, suitable for use as a vehicle airbag fabric, and has excellent physical properties under flexibility, storage properties, and harsh conditions of high temperature and high humidity to reduce the impact on passengers. Research on development is needed.

The present invention is to provide a polyester fabric that ensures excellent mechanical properties, flexibility, storage properties to be used in the fabric for airbags, and maintains sufficient performance under the harsh conditions of high temperature and high humidity.

The present invention also provides a method of manufacturing the polyester fabric.

The present invention also provides a vehicle airbag comprising the polyester fabric.

The present invention includes a polyester yarn having a fineness of 400 to 650 denier, and the inclination direction deactivation index (EI ^wa ) of the fabric as shown in the following formula 1 measured after heat treatment for 4 hours under 85 ℃ and 65% RH conditions It provides a polyester fabric having a 0.15 to 0.38.

[Calculation 1]

EI ^{wa wa} = ER / [(density gradient + weft density) × D ^1/2]

In the above formula, ER ^wa is the diagonal sliding resistance (N) of the polyester fabric measured by the American Society for Testing and Materials Standard ASTM D 6479 method, D is the fineness of the polyester yarn (De).

The present invention also includes the steps of weaving the dough for airbags with a polyester yarn having a fineness of 400 to 650 denier, refining the dough for the woven airbag, and tentering the refined fabric. Provided is a method for producing a fabric.

The present invention also provides a vehicle airbag comprising the polyester fabric.

Hereinafter, a polyester fabric according to a specific embodiment of the present invention, a manufacturing method thereof, and a vehicle airbag including the same will be described in more detail. However, this is presented as an example of the invention, whereby the scope of the invention is not limited, it is apparent to those skilled in the art that various modifications to the embodiments are possible within the scope of the invention.

In addition, unless otherwise indicated throughout the specification, "including" or "containing" refers to the inclusion of any component (or component) without particular limitation and refers to the addition of another component (or component). It cannot be interpreted as excluding.

In the present invention, the airbag fabric refers to a fabric or a nonwoven fabric used for the manufacture of an airbag for an automobile. As a general airbag fabric, a nylon 6 plain fabric or a nylon 6 nonwoven fabric woven with a rapier loom is used. Fabric for airbags of the present invention by using a polyester yarn has excellent characteristics such as shape stability, and basic physical properties such as air permeability, ductility.

However, in order to apply polyester as an airbag yarn instead of polyamide fibers such as conventional nylon 66, the high temperature and high humidity stiffness due to the low folding heat and low melting heat capacity due to the high modulus and stiffness of the polyester yarn Under the conditions, it should be possible to overcome the deterioration of physical properties and consequently the deterioration of development performance.

Polyester has a high stiffness structure compared to nylon in the molecular structure has a high modulus characteristics. For this reason, when used as a fabric for airbags to be mounted on a car, the packing (packing) is significantly reduced. In addition, the carboxyl end groups (hereinafter referred to as "CEG") in the polyester molecular chain attack the ester group under high temperature and high humidity conditions to cause molecular chain breakage, thereby deteriorating physical properties after aging. Becomes

Accordingly, the present invention by using a high modulus low modulus polyester yarn to optimize the physical properties range, such as the fineness of the yarn and the sloping resistance of the inclined direction of the fabric, excellent mechanical properties and air barrier performance while significantly lowering the stiffness It is possible to maintain the back, and the improved physical properties can be obtained as an airbag fabric.

In particular, as a result of the experiments of the present inventors, by producing a fabric for the air bag with a polyester fabric having a predetermined characteristic, it shows a more improved folding properties, shape stability, and air blocking effect, when used as a fabric for the air bag, better storage performance in the vehicle mounting, etc. It has been found that even under the harsh conditions of packing and high temperature and high humidity, excellent mechanical properties, air leakage prevention, airtightness and the like can be maintained.

In accordance with one embodiment of the present invention, a polyester fabric having a predetermined characteristic is provided. Such a polyester fabric, that is, a polyester fabric for an air bag, includes a polyester yarn having a fineness of 400 to 650 denier, and the fabric as shown in the following formula 1 measured after heat treatment for 4 hours at 85 ° C. and 65% RH conditions. The inclination direction sliding resistance index (EI ^wa ) of may be 0.15 to 0.38.

[Calculation 1]

EI ^{wa wa} = ER / [(density gradient + weft density) × D ^1/2]

In the above formula,

ER ^wa is the sloping sliding resistance (N) of polyester fabric measured by the American Society for Testing and Materials, ASTM D 6479 method.

D is the fineness of polyester yarn (De).

In addition, the polyester fabric may be a weft direction sliding resistance index (EI ^we ) of the fabric as shown in the following formula 2 measured after heat treatment for 4 hours at 85 ℃ and 65% RH conditions may be 0.15 to 0.38.

[Equation 2]

EI ^we = ER ^we / [(density gradient + weft density) × D ^1/2]

In the above formula,

ER ^we is the sloped sliding resistance (N) of polyester fabric measured by the American Society for Testing and Materials, ASTM D 6479 method.

D is the fineness of polyester yarn (De).

As a result of the experiments of the present inventors, by using a polyester yarn having a high modulus and a high modulus low modulus compared to a conventional polyester yarn, by optimizing the Edge Comb Resistance of the fabric to a predetermined range, excellent mechanical properties, It has been found that a fabric for an air bag can be provided that can simultaneously improve energy absorption performance for high temperature and high pressure gas, and folding property. In particular, the fabric may include a low fineness high strength polyester yarn, the polyester yarn may be 400 to 650 denier, preferably 420 to 630 denier fineness. In addition, the polyester fabric is inclined direction sliding resistance index (EI ^wa ) of the fabric as shown in the formula 1 measured after heat treatment for 4 hours at 85 ℃ and 65% RH conditions is 0.15 to 0.38, preferably 0.155 to It may be 0.360, it is possible to achieve this by optimizing the inclination direction sliding resistance (ER ^wa ) of the fabric with the fineness (D) of the yarn included in the fabric and the weaving direction of the fabric inclined and weft direction. By optimizing the fineness (D) of the yarn and the sloping sliding resistance (ER ^wa ) of the fabric, the polyester fabric for the airbag ensures improved toughness and energy absorption performance compared to the conventional PET fabric, and has high stiffness ( It can solve the problem of stiffness and the like and can show excellent folding property, flexibility, and storage property.

In addition, the polyester fabric is not only inclined sliding resistance (ER ^wa ), but also by optimizing the sliding resistance (ER ^we ) in the weft direction as described above to improve the excellent mechanical properties, shape stability, storage properties, air blocking effect of the fabric. You can. The weft direction decay resistance (ER ^we ) of the fabric, the warp density and weft density of the fabric and the fineness of the yarn, the weft direction decay resistance index (EI ^we ) of the fabric as shown in the formula 2 is preferably 0.15 to 0.38, preferably It can be optimized to be 0.155 to 0.360.

In the present invention, in order to effectively absorb the impact energy generated instantaneously during the operation of the airbag by adjusting the sliding resistance of the fabric in the optimum range at the same time with the fineness of the yarn constituting the fabric can be improved together with the mechanical properties and folding properties of the final fabric have. It is necessary to optimize the desorption resistance of the fabric together with the fineness of the yarn in order for the fabric to safely absorb the instantaneous impact energy of the exhaust gas generated by the explosives inside the air bag, and at the same time to achieve effective deployment and excellent folding properties. have. At this time, the slide resistance of the fabric in the present invention needs to be able to satisfy the slide resistance index of the fabric represented by the formula 1 or 2 in the predetermined range as described above.

In particular, the sliding resistance of the fabric represented by ER ^wa in the formula 1, that is, the slope sliding resistance of the polyester fabric is 300 N or more or 300 to 970 N, preferably 320 N or more measured at room temperature (25 ℃) Or 320 to 950 N. In this way, by maintaining the inclined direction deactivation resistance (ER ^wa ) of the fabric to 300N or more, it is possible to secure sufficient energy absorption performance during airbag deployment with high toughness. If the slip resistance of the fabric cannot be maintained above the minimum value, the fabric strength of the airbag cushion sewing portion rapidly deteriorates when the airbag is deployed. May occur and be undesirable.

In addition, it is preferable that the inclination direction sliding resistance index (EI ^wa ) of the fabric is 0.15 or more, as shown in Equation 1, in terms of protecting the occupant by absorbing the high-pressure inflator pressure during airbag deployment. It is preferable to be 0.38 or less in view of the receptibility of the airbag cushion assembly. It is difficult to apply the cushion for the airbag when the warp direction sliding resistance index (EI ^wa ) of the fabric does not satisfy the above range. Particularly, when the inclination direction slide resistance index (EI ^wa ) of the fabric is less than 0.15, the slide resistance of the outer sewing seam portion of the airbag cushion is too low when the airbag is deployed, causing pinholes and sticking to occur. It cannot be applied as a cushion. On the other hand, when the inclination direction sliding resistance index (EI ^wa ) of the fabric exceeds 0.38, the sliding resistance of the outer sewing seam portion of the airbag cushion is sufficient so that the problem does not occur when the airbag is deployed. The stiffness of the cushion can make it difficult to be applied to the airbag cushion by worsening the foldability and package of the cushion.

In the polyester fabric, the weft direction sliding resistance of the fabric represented by ER ^we in the formula 2 is 300 N or more or 300 to 970 N, preferably 320 N or 320 or 950 N when measured at room temperature (25 ° C.). Can be. The weft direction sliding resistance (ER ^we ) of the fabric may be 300 N or more in terms of securing high toughness and excellent energy absorption performance of the airbag cushion. In addition, the index weft direction of the fabric hwaltal resistance according to this weft direction hwaltal resistance (ER ^we) (EI ^we) is the formula, in terms of ensuring a sufficient energy absorption performance and good mechanical properties, the folding of the airbag cushion, as described above It can be maintained in the range, ie 0.15 or more and 0.38 or less, as shown in FIG.

The polyester fabric of the present invention may have a warp density and a weft density, that is, a weaving density of the warp direction and the weft direction of 38 to 60, preferably 41 to 57, respectively. The inclined density and the weft density of the polyester fabric may be 38 or more in terms of securing the toughness and desorption resistance of the fabric for airbags, respectively, and 60 or less in terms of improving the folding property and lowering the tear strength of the fabric. Can be.

In addition, the airtightness in the polyester fabric is to minimize the elongation by the high-pressure air or the like, and at the same time to maximize the energy absorption performance in the discharge of gas at high temperature and high pressure to ensure sufficient mechanical properties during operation of the airbag. very important. Accordingly, the fabric has a cover factor of 1,800 to 2,460, preferably 1,880 to 2,360, and weaving the fabric according to the following formula 3 to further improve airtightness and energy absorption performance during airbag deployment.

[Equation 3]

Cover Factor (CF)

Herein, when the cover factor of the fabric is less than 1,800, air may easily be discharged to the outside when the air is inflated. When the cover factor of the fabric exceeds 2,460, the storage and folding properties of the airbag cushion are remarkably increased when the airbag is installed. Can fall.

As described above, the present invention is excellent in energy absorption capacity during airbag inflation by using polyester fibers having high strength-high elongation low modulus rather than conventional polyester fibers having high strength-low elongation and high modulus. In addition, it is possible to provide a polyester fabric for an air bag having excellent shape stability, air barrier property, and excellent folding property, flexibility, and storage property. In addition, the polyester fabric is not only excellent in room temperature physical properties, but also maintains excellent mechanical properties and airtightness after aging (aging) under severe conditions of high temperature and high humidity.

More specifically, the polyester fabric of the present invention is tensile strength measured by the International Organization for Standardization ISO 13934-1 method, that is, the tensile strength of the polyester fabric is at least 2,700 N / 5cm or 2,700 to 4,600 N / 5cm, preferably May be at least 2,850 N / 5 cm or 2,850 to 4,450 N / 5 cm. In the case of the tensile strength, it is preferable to be 2,700 N / 5cm or more in terms of properties of existing airbags, and in reality, it is preferable to be 4,600 N / 5cm or less in terms of physical properties.

In addition, the polyester fabric is 20% to 60% cut elongation measured at room temperature by the International Organization for Standardization ISO 13934-1 method, preferably in the range of about 30% to 50%. In the case of the cut elongation, it is preferable to be 20% or more in terms of properties of existing airbags, and in reality, it is preferable to be 60% or less in terms of physical properties.

Polyester fabric for airbags of the present invention has a toughness (toughness) defined by the formula (4) below 3.5 kJ / ㎥ or more than 3.5 kJ / ㎥ to 6.0 kJ / ㎥, preferably 3.8 kJ / ㎥ or more or 3.8 kJ / ㎥ to May be 5.7 kJ / m 3.

[Calculation 4]

In the formula 4,

F represents the load applied when the length of the polyester fabric increases by dl,

dl represents the length of the polyester fabric.

The polyester fabric can effectively absorb and withstand the energy of hot-high pressure gas as it satisfies a higher level of toughness (fracture) than the conventional fabric. In this case, the toughness is the energy consumed until the fabric is broken by the tensile force, as shown in Equation 4, and means the resistance of the fiber to a sudden impact. If a fiber increases its length from l to l + dl at load F, then the work is F? Dl, so the toughness required to cut the fiber is as shown in Equation 4 above. That is, such toughness represents the cross-sectional area of the yarn and the fabric's strength-elongation curve (see FIG. 1), and the higher the strength and elongation of the yarn used in the fabric, the higher the toughness expressed in the fabric. In particular, when the toughness of the fabric for the airbag is lowered, the resistance of the fabric capable of sufficiently absorbing the instantaneous deployment impact of the inflator having a high temperature-high pressure during airbag deployment becomes low, resulting in the fabric of the airbag being easily torn. Therefore, when the toughness of the fabric in the present invention, for example, less than 3.5 kJ / ㎥ may be difficult to apply to the fabric for the air bag.

In addition, the polyester fabric is required to have an excellent tear strength level because it is rapidly expanded by a high-temperature gas, the tear strength indicating the burst strength of the fabric for the air bag is the US Material Testing Association standard for uncoated fabric When measured by the ASTM D 2261 TONGUE method can be 18 to 30 kgf, the tear strength of the coating fabric can be 30 to 60 kgf, measured by the American Society for Testing and Materials Standard ASTM D 2261 TONGUE method. Here, if the tear strength of the fabric for the airbag is less than the lower limit, i.e., 18 kgf and 30 kgf, respectively, in each of the uncoated fabric and the coated fabric, the airbag bursts when the airbag is deployed, which may cause a great risk to the airbag function. It may be. On the other hand, if the tear strength of the airbag fabric exceeds the upper limit, that is, 30 kgf and 60 kgf, respectively, in the uncoated fabric and the coated fabric, the edge comb resistance of the fabric is lowered and the airbag is deployed. It may be undesirable because the air barrier property deteriorates sharply.

Polyester fabric according to the present invention, the shrinkage and weft direction of the fabric shrinkage measured by the method of the American Society for Testing and Materials ASTM D 1776 can be 1.0% or less, preferably 0.8% or less, respectively, Later, the fabric shrinkage in the warp direction and the weft direction may be 1.0% or less, preferably 0.8% or less, respectively. Here, in terms of the shape stability of the fabric, it is most preferable that the fabric shrinkage ratio in the warp direction and the weft direction do not exceed 1.0%.

As described above, the polyester fabric may maintain a toughness and tear strength of the fabric by using a polyester yarn having high strength and low modulus properties, and at the same time, significantly lower the stiffness of the fabric. The fabric for the air bag has a stiffness of 1.5 kgf or less or 0.3 to 1.5 kgf, preferably 1.2 kgf or less, or 0.3 to 1.2 kgf, more preferably 0.8 kgf or less, or 0.3 to 0.3, according to the American Society for Testing and Materials, ASTM D 4032. 0.8 kgf. As such, the stiffness of the fabric is significantly lowered than that of the conventional polyester fabric. Thus, the fabric for the airbag of the present invention may exhibit excellent folding and flexibility, and improved storage performance when the airbag is mounted. As such, the stiffness of the fabric is significantly lowered than that of the conventional polyester fabric. Thus, the fabric for the airbag of the present invention may exhibit excellent folding and flexibility, and improved storage performance when the airbag is mounted.

In order to use the fabric of the present invention, it is preferable to maintain the above-mentioned stiffness range, and if the stiffness is too low, it may not have sufficient protective support function when the airbag is inflated and deployed. This may degrade the storage. In addition, in order to prevent the deterioration of storage properties and to prevent discoloration of the fabric by becoming too hard and difficult to fold, the stiffness is preferably 1.5 kgf or less, and particularly preferably less than 460 denier, 0.8 kgf or less. Even if it is 550 denier or more, it should be 1.5 kgf or less.

Static air permeability according to the American Society for Testing and Materials Test standard ASTM D 737 method of the polyester fabric is 10.0 cfm or less or 0.3 to 10.0 cfm, preferably 8.0 cfm or less or 0.3 when ΔP is 125 pa for an uncoated fabric. To cpm, more preferably 5.0 cfm or less, or 0.3 to 5.0 cfm, and when ΔP is 500 pa, 14 cfm or less or 4 to 14 cfm, preferably 12 cfm or less, or 4 to 12 cfm. Can be. In addition, the dynamic air permeability according to the American Society for Testing and Materials Standard ASTM D 6476 method is 1,700 mm / s or less, preferably 1,600 mm / s or 200 to 1,600 mm / s, more preferably 1,400 mm / s or 400 To 1,400 mm / s. In this case, the static air permeability refers to the amount of air that penetrates into the fabric when a certain pressure is applied to the fabric for the air bag, and the smaller the denier per filament of the yarn and the higher the density of the fabric, the lower the value. In addition, the dynamic air permeability refers to the degree of air permeation to the fabric when the average instantaneous differential pressure of 30 to 70 kPa is applied. May have

In particular, the air permeability of the polyester fabric can be significantly lowered by including a rubber component coating layer in the fabric, it is possible to ensure an air permeability of approximately 0 cfm. However, when the rubber component coating is performed as described above, the airbag coating fabric of the present invention has a static air permeability of 0.1 cfm or less from 0 to 0.1 cfm when △ P is 125 pa according to the American Society for Testing and Materials Standard ASTM D 737 method. Preferably, it may be 0.05 cfm or less or 0 to 0.05 cfm, and when ΔP is 500 pa, 0.3 cfm or less or 0 to 0.3 cfm, preferably 0.1 cfm or less or 0 to 0.1 cfm.

Here, the polyester fabric of the present invention for the non-coated fabric and the coated fabric, respectively, if the upper limit of the static air permeability range exceeds, or exceeds the upper limit of the dynamic air permeability range to maintain the airtightness of the fabric for the air bag In terms of aspect, this may not be desirable.

The polyester fabric may preferably further comprise a rubber component coating layer coated or laminated to the surface. The rubber component may include at least one selected from the group consisting of powder type silicone, liquid type silicone, polyurethane, chloroprene, neoprene rubber, and emulsion type silicone resin. Is not limited only to the above-mentioned materials. However, silicone coating is preferable in terms of environmentally friendly and mechanical properties.

The coating amount per unit area of the rubber component coating layer may be used to 20 to 200 g / m ² , preferably 20 to 100 g / m ² . Particularly, 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.

On the other hand, in the present invention, in order to ensure excellent performance as the fabric for the airbag, it is preferable to perform various aging to maintain the improved physical properties. In this case, the aging may be performed at least one selected from the group consisting of high temperature aging, cycle aging, and high humidity aging. Preferably, the aging is performed. After this, the strength and physical properties can be maintained to an excellent degree.

Here, the high temperature aging (Heat aging) is made of a heat treatment of the fabric at a high temperature, preferably may be made of a heat treatment for more than 300 hours or 300 to 500 hours at a temperature 110 to 130 ℃. In addition, cycle aging is performed by repeatedly performing high temperature aging, high humidity aging, and low temperature aging on the fabric, preferably aging for 12 to 48 hours at a temperature of 30 to 45 ° C and a relative humidity of 93 to 97% RH. Afterwards, the process of aging for 12 to 48 hours at 70 to 120 ° C. and for aging for 12 to 48 hours at −10 to −45 ° C. may be performed two to five times. Humidity aging consists of aging the fabric under high temperature and high humidity conditions, preferably aging for at least 300 hours or 300 to 500 hours at a temperature of 60 to 90 ° C. and a relative humidity of 93 to 97% RH. .

In particular, the polyester fabric of the present invention has a strength retention ratio of 80% or more, preferably 85% or more, more preferably 90% or more, calculated as a% of the strength measured at room temperature after aging under the above conditions. Can be. As such, even after long-term aging under severe conditions of high temperature and high humidity, the strength and strength of the fabric are maintained in an excellent range, thereby exhibiting excellent performance as an airbag fabric.

On the other hand, according to another embodiment of the invention, there is provided a polyester fabric made of a polyester yarn having a predetermined characteristic. Since polyester yarns used in polyester fabrics for airbags must be maintained at low fineness and high strength, the fineness may be 400 to 650 denier, preferably 420 to 630 denier.

In particular, the present invention by using a polyester yarn having a high modulus and a high modulus low modulus rather than a polyester yarn having a high modulus and a high modulus of high strength, it is not only excellent in the energy absorption capacity during airbag inflation, It is possible to provide a polyester fabric for an air bag having excellent shape stability, air barrier property and excellent folding property.

The fabric of the present invention has an improved intrinsic viscosity, i.e., 0.8 dl / g or more or 0.8 to 1.2 dl / g, preferably 0.85 dl / g or more, or 0.85 to 1.15 dl / g, more than the previously known polyester yarns. Preferably, yarns exhibiting an intrinsic viscosity of at least 0.9 dl / g or from 0.9 to 1.1 dl / g may be used. In order for the fabric for the airbag to maintain excellent physical properties even after aging under severe conditions of normal temperature, high temperature, and high humidity, it is preferable to use a polyester yarn having an inherent viscosity in the above range.

The intrinsic viscosity of the yarn should be 0.8 dl / g or more to exhibit high strength at low elongation to satisfy the required strength when manufacturing the fabric for airbags. Otherwise, the physical properties of high elongation will have to be expressed. Can be. When the high stretching is applied, the orientation of the fiber is increased to show high modulus physical properties, and thus it is difficult to achieve excellent folding properties of the fabric. Therefore, it is preferable to maintain low intrinsic viscosity of 0.8 dl / g or more to enable low modulus expression by applying a low stretching. In addition, when the yarn viscosity is 1.2 dl / g or more, the stretching tension at the time of stretching may increase, which may cause a process problem, so 1.2 dl / g or less is more preferable. In particular, the polyester yarn of the present invention maintains such a high degree of intrinsic viscosity, while providing low ductility with low stretching, and at the same time can provide sufficient mechanical properties, impact resistance, toughness, etc. to the fabric for the airbag Higher strength characteristics can be further imparted.

At the same time, the polyester yarn was heat treated at 185 ° C. for 2 minutes, and the Young's modulus of the yarn measured by the method of ASTM D 885, which is measured by the American Society for Testing and Materials, was 55% at 1% elongation, that is, 1% elongation. To 70 g / de, preferably 58 to 67 g / de, and may be 35 to 52 g / de, preferably 38 to 48 g / de at 2% elongation, ie 2% elongation. In addition, the polyester yarn is 60 to 110 g / de at a point where the Young's modulus of the yarn measured by the method of the American Society for Testing and Materials Test ASTM D 885 at room temperature is 1% elongation, that is, 1% elongation, preferably Preferably from 75 to 105 g / de and from 50 to 87 g / de, preferably from 55 to 85 g / de at 2% elongation, ie at 2% elongation. In the case of polyester yarn as a conventional general industrial yarn, the modulus (Young's modulus) at 1% elongation measured after the heat treatment and at room temperature as described above is 72 g / de or more and 115 g / de or more, respectively. Compared to the modulus at the point of 2% elongation of at least 53 g / de and at least 90 g / de, respectively, the polyester yarns of the present invention can be those having significantly lower modulus at room temperature as well as after heat treatment.

In this case, the modulus of the polyester yarn is a physical property value of the elastic modulus obtained from the slope of the elastic section of the stress-strain diagram obtained in the tensile test, and when the object is stretched from both sides, the elastic modulus indicating the degree of stretching and deformation of the object The value corresponds to If the modulus of the fiber is high, the elasticity is good, but the stiffness of the fabric may be deteriorated. If the modulus is too low, the stiffness of the fabric is good, but the elasticity of the fabric may be low, and thus the toughness of the fabric may be deteriorated. As such, airbag fabrics made from polyester yarns having a lower initial modulus than conventional ones at room temperature as well as after heat treatment solve high stiffness problems of conventional polyester fabrics, and have excellent folding properties, Flexibility and storage capacity can be exhibited.

Toughness of the polyester yarn can be measured using a polyester yarn in place of the polyester fabric in Formula 4, and the toughness of the yarn thus measured after heat treatment at 185 ° C. for 2 minutes is 70 to 120 J / M 3, preferably 75 J / m 3 to 110 J / m 3, and the toughness of the yarn measured at room temperature without additional heat treatment is also 70 J / m 3 to 120 J / m 3, preferably 85 J / m M 3 to 115 J / m 3. In particular, in the present invention, by using a specific polyester yarn that meets a high level of toughness (toughness) compared to the conventional polyester yarn, for airbags that can effectively absorb and withstand the energy of hot-high pressure gas Fabric may be provided.

Therefore, it is possible to manufacture a fabric for an airbag which simultaneously exhibits excellent mechanical properties and storage properties, form stability, impact resistance, and air barrier effect by using a polyester yarn exhibiting such low initial modulus and high elongation, preferably high intrinsic viscosity. Become. Therefore, the polyester fabric of the present invention is made of a fabric for an air bag using the polyester yarn, showing a lower ductility and folding properties, flexibility, storage properties, but also excellent impact resistance, form stability, mechanical properties, airtightness Can be. These polyester fabrics provide excellent mechanical properties, shape stability, and air barrier effects, but also provide excellent folding and storage properties when mounted in tight spaces of cars, while providing excellent flexibility to minimize the impact on passengers to protect passengers. Since it can be, it can be preferably applied as a fabric for airbags.

In addition, the polyester yarn, the shrinkage stress at 150 ℃ corresponding to the laminate coating temperature of the general coating fabric of the yarn is preferably 0.005 to 0.075 g / d, 200 ℃ corresponding to the sol coating temperature of the general coating fabric It is preferable that the shrinkage stress at is 0.005 to 0.075 g / d. That is, the shrinkage stress at 150 ° C. and 200 ° C. should be 0.005 g / d or more, respectively, to prevent sagging of the fabric due to heat during the coating process, and should be 0.075 g / d or less to be cooled at room temperature after the coating process. Relaxation stress can be alleviated. The shrinkage stress is based on values measured under a fixed load of 0.10 g / d.

In particular, the polyester yarn has a dry heat shrinkage measured at room temperature of at least 1.0% or 1.0% to 10%, preferably at least 1.5% or at least 1.5% to 8.0%, more preferably at least 2.0% or 2.0, measured at room temperature without additional heat treatment. % To 6.0%. In this way, by maintaining the dry heat shrinkage ratio of polyester yarn in the optimum range, it has high strength and high modulus, low modulus characteristics to secure excellent strength and flexibility, and excellent shrinkage characteristics to effectively control the air permeability of the fabric and mechanical properties such as desorption resistance Physical properties can be improved.

In order to prevent deformation in the heat treatment process such as coating as described above, the polyester yarn is also 40% to 55% crystallinity, preferably 41% to 52%, more preferably 41% to 50% Can be. The degree of crystallinity of the yarn should be more than 40% to maintain thermal morphological stability when applied to the fabric for airbags, and when the crystallinity exceeds 55%, there is a problem that the impact absorption performance is deteriorated because the amorphous region is reduced It is preferable to become 55% or less.

In addition, the polyester yarn may have a tensile strength of 8.1 g / d to 9.5 g / d measured after the heat treatment for 2 minutes at 185 ℃, preferably 8.3 g / d to 9.3 g / d, more Preferably from 8.4 g / d to 9.0 g / d, the cut elongation measured after the heat treatment 20 to 35%, preferably 21% to 32%, more preferably 22% to 28% Can be represented. In addition, the tensile strength of the yarn at room temperature without a separate heat treatment may be 8.9 g / d to 11.0 g / d, preferably 9.0 g / d to 10 g / d, preferably 9.1 g / d to 9.8 g / d, and the elongation at break may represent 15% to 30%, preferably 16% to 26%, more preferably 17% to 25%.

It is preferable that the said polyester yarn is a polyethylene terephthalate (PET) yarn among normal polyester, More preferably, it is a PET yarn containing 90 mol% or more of PET. In particular, the fabric of the present invention has a polyester polymer having an intrinsic viscosity of at least 1.2 dl / g or 1.2 to 1.8 dl / g, preferably at least 1.25 dl / g or 1.25 to 1.75 dl / g, ie PET chips It can be used a polyester yarn prepared. In order for the airbag fabric to maintain excellent physical properties even after aging under severe conditions of normal temperature, high temperature, and high humidity, it is preferable to prepare a polyester yarn from a polyester polymer having an intrinsic viscosity of 1.2 dl / g or more. In addition, in order to secure the thermal stability of the polymer during yarn production and to minimize the increase in the carboxyl end group content due to the molecular chain cleavage may include a polyester yarn made of a polyester polymer having an intrinsic viscosity of 1.8 dl / g or less. At this time, the polyester yarn is manufactured using a high viscosity PET polymer having a low carboxyl end group (CEG, Carboxyl End Group) content, preferably 30 meq / kg or less, having a high strength and high elongation characteristics Can be.

In addition, the polyester yarn may be a single yarn fineness of 2.5 to 6.8 DPF, preferably 2.75 to 4.55 DPF. The single yarn fineness of the yarn is preferably 2.5 DPF or more in terms of weaving performance and yarn manufacturing (spinning) performance of the fabric for airbags, and 6.8 DPF or less in terms of air barrier properties and storage properties of the fabric for airbags. The more filaments of the yarn may give a soft touch, but if too many may have poor radioactivity, the number of filaments may be 96 to 160.

As already described above, the polyester fabric of the present invention can exhibit excellent performance when manufactured as a fabric for airbags using a polyester yarn having an intrinsic viscosity, initial modulus, and elongation range in an optimal range.

Polyester yarns used in fabrication of the present invention may be produced by melt spinning PET polymer to produce undrawn yarn, and stretching the undrawn yarn. In the yarn manufacturing process, the specific conditions or the progress method of each step is directly or indirectly reflected in the physical properties of the polyester yarn can be produced a polyester yarn that can be effectively used in the fabric for the air bag of the present invention.

 In particular, in a more preferred embodiment, the high strength, high elongation, low modulus polyester yarn is 270 to 310 ℃ using a high viscosity polymer containing at least 70 mol% polyethylene terephthalate and has an intrinsic viscosity of at least 1.2 dl / g Melt spinning at low temperature to prepare a polyester non-drawn yarn, and the polyester non-drawn yarn can be prepared by a method comprising the step of stretching under the draw ratio conditions of 5.0 to 6.5. At this time, the intrinsic viscosity of the yarn by melt spinning under low temperature conditions, more preferably low temperature / low speed conditions using a high viscosity PET polymer having a low carboxyl end group (CEG) content, preferably 30 meq / kg or less It is possible to suppress the degradation and increase the CEG content to the maximum, and to maintain high elongation characteristics while maintaining excellent mechanical properties of the yarn. Furthermore, by performing the stretching under the optimized drawing ratio conditions of 5.0 to 6.5 in the subsequent drawing process, by suppressing the lowering of the elongation of the yarn as much as possible, to prepare a polyester yarn having a high strength high elongation low modulus effectively to the fabric for airbags Applicable

In this case, when the melt spinning process is performed at a high temperature, for example, when it is performed at above 310 ° C., thermal decomposition of the PET polymer may occur in a large amount, which may lower the intrinsic viscosity and increase the CEG content. In addition, an increase in intramolecular orientation at high temperature may cause a decrease in elongation and increase in modulus, and may cause a decrease in overall physical properties due to surface damage of the yarn. Along with this, when the drawing process is carried out under too high draw ratio, for example, a draw ratio exceeding 6.5, it may be over-stretched, so that cutting or mousse may occur in the drawn yarn. It is difficult to exhibit desirable physical properties for use as an airbag fabric. In addition, when the stretching process is performed under a relatively low draw ratio, the fiber orientation is low, and thus the strength of the polyester yarn manufactured therefrom may be partially lowered. Preferably, the drawing process is performed under a draw ratio of 5.0 or more to be applied to fabrics for airbags. It is possible to produce polyester yarns of high strength, high elongation, low modulus, which are suitable for.

On the other hand, in terms of manufacturing a polyester yarn which is a high strength and a low modulus high elongation under such high draw ratio conditions, it can be carried out by adjusting the conditions, such as relaxation rate of the subsequent process in an appropriate range. At this time, the relaxation rate may be 14% or less or 1% to 14%, preferably 10% or less or 1% to 10%, more preferably 7% or less or 1.1% to 7%. have. The lower limit of the relaxation rate may be selected in a range that allows sufficient yarn shrinkage to be expressed, for example, 1% or more. In some cases, if the relaxation rate is too small, for example, less than 1%, it may be difficult to produce high elongation low modulus fibers as high fiber orientation is formed as well under high draw ratio conditions. In addition, when the relaxation rate exceeds 14%, it may be difficult to secure workability due to severe noise on the high-speed roller.

Through such process optimization, it is possible to secure a polyester yarn for airbags having a high initial strength and low elongation and high elongation. In addition, through optimization of the melt spinning and stretching process, it is possible to minimize the carboxyl end groups (CEGs), which exist as acids under high humidity conditions and cause basic molecular chain cleavage of polyester yarns. Therefore, such a polyester yarn exhibits a low initial modulus and a high elongation range at the same time, and thus can be preferably applied to fabrics for airbags having excellent mechanical properties and storage properties, shape stability, impact resistance, and air blocking effect.

On the other hand, according to another embodiment of the invention, there is provided a method for producing a fabric for airbags using a polyester yarn. The manufacturing method of the fabric for airbags according to the present invention comprises the steps of weaving the dough for airbags using a polyester yarn having a fineness of 400 to 650 deniers, refining the woven fabric for airbags, and tentering the refined fabric It may include the step.

In the present invention, the polyester yarn may be produced as a final airbag fabric through a conventional weaving method, refining and tentering process. At this time, the woven form of the fabric is not limited to a specific form, both the plain type and OPW (One Piece Woven) type of woven form is preferred.

In particular, the fabric for the airbag of the present invention can be produced through a beaming, weaving, refining, and tenterizing process using the polyester yarn as a weft and warp yarn. The fabric can be produced using a conventional weaving machine, and is not limited to using any particular loom. However, plain weave fabrics can be manufactured using rapier looms, air jet looms, or water jet looms. OPW fabrics are Jacquard looms. Loom).

However, the present invention, by using a polyester yarn having a high shrinkage of high strength and high elongation compared to the conventional polyester yarn, it is possible to perform a heat treatment process at a higher temperature than conventional. That is, in the present invention, after the process of refining and tentering the woven dough, coated with a rubber component on the tentered fabric and dried, the vulcanization temperature 140 to 210 ℃, preferably 150 to 205 ℃, and most preferably Is carried out a curing process at 180 to 200 ℃, the vulcanization temperature should be more than 140 ℃ in terms of maintaining mechanical properties, such as tear strength of the fabric, and should be less than 210 ℃ in terms of lecture. In particular, the heat treatment process may be carried out in a multi-step, for example, after performing the first heat treatment process at 150 to 170 ℃, after performing the second heat treatment process at 170 to 190 ℃, 3 at 190 to 210 ℃ A differential heat treatment process can be performed.

As such, when the polyester fabric of the present invention is manufactured through a high-temperature heat treatment process, the optimized shrinkage characteristics of the polyester yarn itself can give the effect of excellent morphological stability, air barrier effect, stiffness improvement, and tear strength improvement. Can be.

In addition, the curing time at the vulcanization temperature may be carried out in the range of 30 to 120 seconds, preferably 35 to 100 seconds, and most preferably 40 to 90 seconds. In this case, when the curing time is less than 30 seconds, there is a problem that the hardening of the coating layer by the rubber component is not effectively performed and the mechanical properties of the fabric are lowered, so that the coating is peeled off. When the curing time exceeds 120 seconds, Due to the increase in the stiffness and thickness of the final fabric is produced a problem of poor folding properties.

The airbag fabric of the present invention can be coated on the one or both sides of the fabric by the rubber component as described above, the coating layer of the rubber component can be applied by knife coating method, doctor blade method, or spray coating method. However, this too is not limited to the above-mentioned method.

The coated airbag fabric may be manufactured in the form of an airbag cushion having a predetermined shape while cutting and sewing. The airbag is not limited to a particular form and may be manufactured in a general form.

On the other hand, according to another embodiment of the invention, there is provided a vehicle airbag comprising the polyester fabric described above. In addition, there is provided an airbag system comprising the above airbag, which may be provided with conventional devices well known to those skilled in the art.

The airbag may be largely classified into a frontal airbag and a side curtain airbag. The frontal airbag includes a driver's seat, a passenger seat, a side protection, a knee protection, ankle protection, a pedestrian protection airbag, and the side curtain type airbag protects passengers in a vehicle collision or rollover accident. Accordingly, the airbag of the present invention includes both a frontal airbag and a side curtain airbag.

In addition, the polyester fabric by using a high strength and high modulus low modulus yarn to optimize the deactivation resistance to secure excellent mechanical properties, flexibility, storage, etc., when applied to a vehicle airbag, pure pyrotechnic type inflator, It can be commercialized to be used for both hybrid inflator composed of gunpowder and inert gas, and cold gas inflator composed only of inert gas.

In particular, the side curtain type airbag including the polyester fabric of the present invention has a maximum pressure of 40 kPa or more at the time of initial airbag inflation (at deployment) when an instantaneous pressure of 13 bar or more is injected, and a pressure after 25 seconds has elapsed. By maintaining above kPa, it is possible to exert a proper function as an airbag for passenger protection and the like during rollover of the vehicle with excellent pressure resistance performance.

In the present invention, matters other than those described above can be added or subtracted as required, and therefore, the present invention is not particularly limited thereto.

According to the present invention, there is provided a polyester fabric for airbags having excellent energy absorption performance in airbag deployment, and a vehicle airbag obtained using the same.

This airbag fabric uses low modulus, high strength, and high elongation polyester yarn to minimize heat shrinkage even through high temperature heat treatment process, and at the same time obtain excellent form stability, mechanical properties, and air barrier effect. Excellent folding and flexibility can be secured, which significantly improves the storage performance of the vehicle and at the same time minimizes the impact on the passengers to protect the occupants.

Therefore, the polyester fabric of the present invention can be very preferably used for the production of vehicle airbags and the like.

Figure 1 shows an example of the strength-elongation curve of a general fiber, the area of this strength-elongation curve can be defined as toughness (breaking days, J / ㎥).
Figure 2 shows the strength-elongation curve of the polyester fabric according to Example 3 of the present invention.
Figure 3 shows the strength-elongation curves of polyester fabric according to Comparative Example 3 of the present invention.

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  1-5

After producing a polyester yarn in one step from a PET chip having a predetermined intrinsic viscosity through a melt spinning machine, weaving the fabric dough for airbags through a rapier weaving machine using the yarns, and then refining and tentering the airbags. Fabrics were prepared for the coating, and a liquid silicone rubber (LSR) resin was coated on the fabric by a knife over method to prepare a silicon coated fabric.

At this time, the intrinsic viscosity, CEG content, melt spinning temperature, elongation ratio, and the intrinsic viscosity, toughness, elongation of 1% and 2% of PET chips, physical properties such as modulus, tensile strength, cutting elongation, dry heat shrinkage, etc. As shown, the physical properties of the yarn was measured at room temperature (25 ℃ x 65% RH).

In addition, the warp and weft density of the fabric, weaving form, heat treatment temperature, rubber components, resin coating amount is as shown in Table 1, the remaining conditions were in accordance with the conventional conditions for the production of polyester fabric for airbags.

division Example 1 Example 2 Example 3 Example 4 Example 5 PET content (mol%) 100 100 100 100 100 Intrinsic viscosity of PET chip (dl / g) 1.25 1.33 1.40 1.50 1.60 CEG of PET chip (meq / kg) 30 27 24 23 22 Spinning temperature (℃) 293 295 295 295 295 Elongation ratio 5.99 6.03 6.07 6.11 6.15 Intrinsic Viscosity of Yarn (dl / g) 0.92 0.96 0.98 1.01 1.04 Toughness of yarn
(Toughness, J / ㎥) 96.5 97 99 103 106 Modulus of yarn
(At elongation 1%, g / de) 99 96 97 94 98 Modulus of yarn
(At elongation 2%, g / de) 78 76 77 76 77 Tensile Strength of Yarn (g / de) 9.1 9.15 9.20 9.3 9.33 Yarn Elongation (%) 16.5 17 18.5 17.2 17.6 Dry heat shrinkage (%) 3.82 3.23 2.92 4.61 4.17 Single Sand Island (DPF) 420 420 420 600 600 Total fineness (de) 110 130 144 130 144 Filament number 49 x 49 49 x 49 49 x 49 43 x 43 43 x 43 Weaving Density (Inclined X Weft) 100 100 100 100 100 Weaving Form Plain weave Plain weave Plain weave Plain weave Plain weave Heat treatment / vulcanization temperature (℃) 160-180 165-185 170-190 160-185 165-190 Rubber ingredient Liquid silicone Liquid silicone Liquid silicone Liquid silicone Liquid silicone Rubber coating amount (g / m ² ) 25 25 25 25 25

Physical properties of the polyester fabrics prepared according to Examples 1 to 5 were measured by the following methods, and the measured physical properties are summarized in Table 2 below.

(a) Tensile strength and elongation at break

Cut the specimen with uncoated fabric before coating and fix it to the lower clamp of the tensile strength measuring device according to the International Organization for Standardization (ISO 13934-1) method.Tensile strength at the time of breaking the airbag fabric specimen while moving the upper clamp upward And elongation at break was measured.

(b) tear strength

Tear strength was measured for uncoated fabrics in accordance with the American Society for Testing and Materials, ASTM D 2261 TONGUE.

First, the non-coated fabric before coating treatment is used to cut 75 mm x 200 mm in each specimen, and then the upper and lower portions of the specimen are respectively top and bottom in an apparatus according to the American Society for Testing and Materials ASTM D 2261 TONGUE. Was positioned between the left and right spaces of the jaw face. Thereafter, the spacing of the jaw face is based on 76 mm, respectively, in the opposite direction, ie with the upper biting device moving upwards and the lower material device moving downwards at 300 mm / min. The strength at which the fabric broke was measured.

(c) bow resistance

The polyester fabric is an uncoated fabric before coating treatment, and after heat treatment for 4 hours at 85 ℃ and 65% RH conditions to cut the fabric specimens, at room temperature (25 ℃) by the method according to the ASTM D 6479 standard The slide resistances in the warp direction and the weft direction (ER ^wa , ER ^we ) were measured, respectively.

On the other hand, using the measured inclined direction slide resistance (ER ^wa ) of the fabric and the inclined density, weft density and the fineness of the yarn (D) of the fabric, the inclined direction slide resistance index (EI) of the fabric as shown in the following formula 1 ^wa ) was estimated.

[Calculation 1]

EI ^{wa wa} = ER / [(density gradient + weft density) × D ^1/2]

In the above formula,

ER ^wa is the sloping sliding resistance (N) of polyester fabric measured by the American Society for Testing and Materials, ASTM D 6479 method.

D is the fineness of polyester yarn (De).

In addition, the weft direction decay resistance of the fabric as shown in the following formula 2, using the weft direction decay resistance (ER ^we ) of the fabric and the warp density, weft density and the fineness of the yarn (D) of the fabric measured as described above. The index (EI ^we ) was calculated.

[Equation 2]

EI ^we = ER ^we / [(density gradient + weft density) × D ^1/2]

In the above formula,

ER ^we is the weft direction sliding resistance (N) of the polyester fabric measured by the American Society for Testing and Materials Standard ASTM D 6479 method,

D is the fineness of polyester yarn (De).

(d) Cover factor (CF)

The cover factor value for the uncoated fabric was calculated by the following Equation 3.

[Equation 3]

Cover Factor (CF)

(e) Toughness of the fabric

Toughness (J / m 3) values were calculated by the following equation (3).

[Calculation 4]

In the formula 4,

F represents the load applied when the length of the polyester fabric increases by dl,

dl represents the length of the polyester fabric.

At this time, the toughness of the fabric was measured with an uncoated fabric before coating treatment.

(f) Fabric shrinkage rate

Fabric shrinkage in the warp / weft direction was measured according to the American Society for Testing and Materials, ASTM D 1776. First, after cutting the specimen with an uncoated fabric before coating treatment, mark the length before shrinking in the warp and weft directions by 20 cm, and measure the contracted length of the specimen heat-treated in the chamber at 149 ° C. for 1 hour in the warp direction. And weaving shrinkage ratio {(length before contraction-length after contraction) / length before contraction x 100%} in the weft direction.

(g) lecture

The uncoated fabric before coating treatment was measured by the circular bend method using a ductility measuring apparatus according to the American Society for Testing and Materials Standard ASTM D 4032. In addition, the cantilever method may be applied as a method of measuring the stiffness, and the stiffness can be measured by measuring the bend length of the fabric using a cantilever measuring device, which is a test bench that is inclined at an angle to give a bend to the fabric.

(h) after

The thickness of the uncoated fabric before coating treatment was measured according to the American Society for Testing and Materials, ASTM D 1777.

(i) air permeability

After allowed to stand over one day under the American Society for Testing and Materials specification according to ASTM D 737 20 ℃ the uncoated fabric before coating, 65% RH, △ P, each 125 of the pressure pa and 500 pa of the air is 38 cm ² The amount passing through the circular section was measured and expressed as static air permeability.

In addition, according to ASTM D 6476, the dynamic air permeability of the uncoated fabric was measured using a TEXTEST FX 3350 Dynamic Air Permeability Tester.

division Example 1 Example 2 Example 3 Example 4 Example 5 Tensile strength of fabric (N / 5cm) 3,050 3,130 3,180 4,100 4,150 Elongation at break of fabric (%) 28.9 30.3 32.3 30.5 32 Tear Strength (kgf) / Coating of Fabric 36 37 38 38 40 Gradient sliding resistance
(ER ^wa , N) 398 415 427 550 570 Inclination Resistance Index
(EI ^wa ) 0.198 0.207 0.213 0.261 0.271 Weft Slide Resistance
(ER ^we , N) 409 432 446 576 592 Weft Direction Resistance Index
(EI ^we ) 0.204 0.215 0.222 0.273 0.281 Fabric Cover Factor 2,008 2,008 2,008 2,107 2,107 Fabric toughness
(Toughness, kJ / ㎥) 3.75 3.83 3.92 5.4 5.6 Fabric Shrinkage (%) 0.5 0.5 0.4 0.4 0.5 Lecture degree (kgf) 0.40 0.40 0.38 1.00 0.90 Thickness (mm) 294 294 295 338 338 silence
Air permeability
(cfm) △ P = 125 pa 1.0 0.9 0.8 0.6 0.6 △ P = 500 pa 9.5 9.3 9.2 5.4 5.4 Dynamic Air Permeability (mm / s) 620 610 590 450 430

Comparative example  1-5

A polyester fabric for airbags of Comparative Examples 1 to 5 was prepared according to the same method as Examples 1 to 5 except for the conditions described in Table 3 below.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 PET content (mol%) 100 100 100 100 100 Intrinsic viscosity of PET chip (dl / g) 0.75 0.79 0.85 0.83 0.88 CEG of PET chip (meq / kg) 50 47 43 47 43 Spinning temperature (℃) 301 302 305 302 305 Elongation ratio 4.90 4.95 5.00 4.95 5.00 Intrinsic Viscosity of Yarn (dl / g) 0.60 0.61 0.62 0.61 0.62 Toughness of yarn
(Toughness, J / ㎥) 55 57 59 59 61 Modulus of yarn
(At elongation 1%, g / de) 115 119 125 119 125 Modulus of yarn
(At elongation 2%, g / de) 90 93 93 92 92 Tensile Strength of Yarn (g / de) 6.7 6.9 7.0 6.8 7.3 Yarn Elongation (%) 11.5 12.3 13.8 14.3 14.8 Dry heat shrinkage (%) 14.5 12.6 10.4 11.0 10.8 Single Sand Island (DPF) 9.2 9.2 9.2 10.0 9.44 Total fineness (de) 460 460 460 680 680 Filament number 50 50 50 68 72 Weaving Density (Inclined X Weft) 49 x 49 49 x 49 49 x 49 43 x 43 43 x 43 Weaving Form Plain weave Plain weave Plain weave Plain weave Plain weave Heat treatment / vulcanization temperature (℃) 140-165 150-170 150-175 140-170 150-175 Rubber ingredient Liquid silicone Liquid silicone Liquid silicone Liquid silicone Liquid silicone Rubber coating amount (g / m ² ) 25 25 25 25 25

Physical properties of the polyester fabric prepared according to Comparative Examples 1 to 5 are summarized in Table 4 below.

division Example 1 Example 2 Example 3 Example 4 Example 5 Tensile strength of fabric (N / 5cm) 2,350 2,400 2,450 3,320 3,380 Elongation at break of fabric (%) 13 14 14 13 14 Tear Strength (kgf) / Coating of Fabric 21 23 23 23 24 Gradient sliding resistance
(ER ^wa , N) 270 280 285 320 327 Inclination Resistance Index
(EI ^wa ) 0.128 0.133 0.136 0.143 0.146 Weft Slide Resistance
(ER ^we , N) 275 283 290 325 332 Weft Direction Resistance Index
(EI ^we ) 0.131 0.135 0.138 0.145 0.148 Fabric Cover Factor 2,102 2,102 2,102 2,243 2,243 Fabric toughness
(Toughness, kJ / ㎥) 2.5 2.7 2.9 2.7 2.9 Fabric Shrinkage (%) 1.3 1.3 1.2 1.2 1.1 Lecture degree (kgf) 1.65 1.60 1.60 2.3 2.3 Thickness (mm) 288 288 288 350 350 silence
Air permeability
(cfm) △ P = 125 pa 2.7 2.8 2.8 2.2 2.1 △ P = 500 pa 14.0 14.2 14.1 12.6 12.5 Dynamic Air Permeability (mm / s) 2,200 1,250 2,250 1,950 1,850

As shown in Tables 2 and 4 above, the polyester toughness for airbags of Examples 1 to 5 in which the desorption resistance was optimized to a predetermined range by using a high modulus and a high modulus low modulus polyester yarn according to the present invention, was 3.75 to 3. 5.6 kJ / m ³ , the tear strength of the coated fabric is 36 to 40 kgf, the tensile strength is 3050 to 4150 N / 5cm, the tensile elongation is 28.9 to 32.3% so that the hot-high pressure inflator gas (gas) during airbag deployment Excellent mechanical properties that can withstand). In addition, it can be seen that the fabric has a very excellent characteristic of the fabric shrinkage rate 0.4% to 0.5% and 0.3 to 0.4% in the inclined direction and the weft direction, respectively. At the same time, it can be seen that the polyester fabrics of Examples 1 to 5 have an excellent optimum range of 0.38 to 1.0 kgf of stiffness, and thus have excellent foldability and storage property with excellent shape stability.

In particular, the polyester fabrics of Examples 1 to 5 using a high modulus, low modulus yarn, the static air permeability (△ P = 125 pa) of the uncoated fabric is 0.6 to 1.0 cfm level, static air permeability (△ P = 500 pa) can be seen that very good airtight results can be obtained at the level of 5.4 to 9.5 cfm. In addition, although the cover factor of the fabric is relatively low value of 2,008 to 2,107, the sealing slippage phenomenon at the seam area of the cushion during airbag cushion deployment is greatly improved, and the airtightness and energy absorption performance of the cushion is further improved. It can be seen that it can be improved.

On the other hand, as shown in Table 4, it was confirmed that the polyester fabric of Comparative Examples 1 to 5 using a low-viscosity general industrial polyester yarn did not meet these characteristics. In particular, the polyester fabrics of Comparative Examples 1 to 5 have shrinkage in the warp direction and the weft direction of 1.1% to 1.3% and 0.9% to 1.2%, respectively, and the tensile strength is 2350 to 3380 N / 5cm, and the tearing steel of the coated fabric It can be seen that the degree drops significantly from 21 to 24 kgf. As such, when a fabric having significantly lower mechanical properties such as tensile strength and tear strength is used in the airbag device, problems may occur due to a decrease in mechanical properties such as an airbag bursting when the airbag is deployed.

In addition, the static air permeability (△ P = 125 pa) of the uncoated fabric according to Comparative Examples 1 to 5 is 2.1 to 2.8 cfm level, the static air permeability (△ P = 500 pa) is largely 12.5 to 14.0 cfm level. It can be seen that the increase in airtightness, and when the air permeability is increased in this way, the air can easily escape during deployment of the airbag, which may cause a problem that the airbag does not sufficiently perform the role. Furthermore, although the cover factor of the fabric is 2,102 to 2,243, which is a relatively high value compared to Examples 1 to 5, the slippage phenomenon at the seam area of the cushion during airbag cushion deployment is rather deteriorated, and the airtightness of the cushion and There is also a lot of problems to be applied to the fabric for airbag cushion due to lack of energy absorption performance.

In addition, the strength-elongation curves of the polyester fabrics according to Example 3 and Comparative Example 3 are shown in FIGS. 2 and 3, respectively. Polyester fabric according to Example 3 can be seen that shows a high toughness in the strength-elongation graph, as shown in FIG. On the other hand, it can be seen that the polyester fabric according to Comparative Example 3 exhibits low toughness in the strength-elongation graph, as shown in FIG. 3. Therefore, the polyester fabric according to Example 3 has an excellent ability to absorb the hot-high pressure inflator gas energy when the airbag is deployed, but also has an excellent advantage in terms of airtight packing performance. However, the polyester fabric according to Comparative Example 3 is not suitable for use as a fabric for airbags by not only insufficient absorbing performance of the instantaneous impact energy of the exhaust gas during airbag deployment, but also worsens the air blocking effect performance. It can be seen that.

Experimental Example  One

Examples 1 to 5 and Comparative Examples 1 to 5 to prepare an airbag cushion using a polyester uncoated fabric not subjected to the coating process, respectively as shown in Table 5 driver airbag cushion assembly or PAB (passenger airbag) A vehicle airbag was manufactured from the cushion assembly. The vehicle air bag thus completed was subjected to a static test under three heat treatment conditions (at room temperature: 25 ° C x 4 hr oven left, Hot: 85 ° C x 4 hr oven left, Cold: -30 ° C x 4 hr oven left). ) Was performed. When the result of the static test indicates that the fabric tearing, pinhole generation, and fabrication carbonization do not occur, it is evaluated as "Pass", and the fabric tearing, sewing hole pinhole, or fabrication are evaluated. If any of the carbonizations occurred, it was evaluated as "Fail".

The results of the static test evaluation of the airbag cushions manufactured using the polyester uncoated fabrics of Examples 1 to 5 and Comparative Examples 1 to 5 are shown in Table 5 below.

division Cushion specifications Explosive Inflator Pressure (kPa) Room temperature
Deployment test Hot
Deployment test Cold
Deployment test Example 1 DAB 190 Pass Pass Pass Example 2 DAB 190 Pass Pass Pass Example 3 DAB 190 Pass Pass Pass Example 4 PAB 330 Pass Pass Pass Example 5 PAB 330 Pass Pass Pass Comparative Example 1 DAB 190 Fail Fail Fail Comparative Example 2 DAB 190 Fail Fail Fail Comparative Example 3 DAB 190 Fail Fail Fail Comparative Example 4 PAB 330 Fail Fail Fail Comparative Example 5 PAB 330 Fail Fail Fail

As shown in Table 5, each of the three heat treatment temperature conditions for the vehicle airbag including the polyester fabric of Examples 1 to 5 by optimizing the range of the slide resistance resistance using a polyester yarn of a specific fineness range according to the present invention As a result of the development test after leaving the oven under the oven, it was found that the fabric was not torn, the pinholes of the sewing part, the carbonization of the fabric did not occur, and all of them had excellent performance as a vehicle airbag.

On the other hand, in the development test results for the vehicle airbag including the polyester fabric of Comparative Examples 1 to 5, each cushion is " Fail "indicates that it cannot be used as an actual airbag. Particularly, in the development test for the DAB (driver airbag) cushion assembly including the fabrics of Comparative Examples 1, 2, and 3, tearing of the fabric occurred at the outer seam of the cushion. The tearing occurred, and in the case of Comparative Example 5, the tearing of the fabric occurred at the main panel seam weld.

In addition, in the deployment test for the vehicle airbag including the fabrics of Comparative Examples 1 to 5, it could be confirmed that the fabric tears occurred together due to the occurrence of the pinholes and the carbonization of the sewing portion. Therefore, the airbag fabric of Comparative Examples 1 to 5 may cause a great risk to the airbag function due to airbag rupture, etc. when applied to the actual airbag cushion for the vehicle.

Claims (14)

A polyester yarn having a fineness of 400 to 650 denier,
Polyester fabrics having an inclined sliding resistance index (EI ^wa ) of 0.15 to 0.38 of the fabric as shown in the following formula 1, measured after heat treatment for 4 hours under 85 ° C. and 65% RH:
[Calculation 1]
EI ^{wa wa} = ER / [(density gradient + weft density) × D ^1/2]
In the above formula,
ER ^wa is the sloping sliding resistance (N) of polyester fabric measured by the American Society for Testing and Materials, ASTM D 6479 method.
D is the fineness of polyester yarn (De). The method of claim 1,
Polyester fabrics having a weft sliding resistance index (EI ^we ) of 0.15 to 0.38 of the fabric as shown in the following formula 2, measured after heat treatment at 85 ° C. and 65% RH for 4 hours:
[Equation 2]
EI ^we = ER ^we / [(density gradient + weft density) × D ^1/2]
In the above formula,
ER ^we is the sloped sliding resistance (N) of polyester fabric measured by the American Society for Testing and Materials, ASTM D 6479 method.
D is the fineness of polyester yarn (De). The method of claim 1,
A polyester fabric for airbags having a cover factor of 1,800 to 2,460 as defined by Formula 3 below:
[Calculation 3]
Cover Factor (CF)

The method of claim 1,
Polyester fabric with a stiffness of 1.5 kgf or less according to ASTM D 4032 method. The method of claim 1,
Static air permeability according to the ASTM D 737 method of the American Material Testing Association is 10 cfm or less when △ P 125 pa, 14 cfm or less when △ P 500 pa. The method of claim 1,
Polyester fabric having a dynamic air permeability of 1,700 mm / s or less according to the ASTM D 6476 method. The method of claim 1,
A polyester fabric comprising a polyester yarn having a tensile strength of 8.1 g / d to 9.5 g / d and an elongation at break of 20% to 35% measured after heat treatment at 185 ° C. for 2 minutes. The method of claim 1,
After heat treatment at 185 ° C. for 2 minutes, the Young's modulus measured by the method of ASTM D 885 of the American Society for Testing and Materials is 55 to 70 g / de at 1% elongation and 35 to 52 g / de at 2% elongation. Polyester fabric comprising polyester yarns. The method of claim 1,
A polyester fabric coated with at least one rubber component selected from the group consisting of powder type silicone, liquid type silicone, polyurethane, chloroprene, neoprene rubber, and emulsion type silicone resin. 10. The method of claim 9,
Polyester fabric having a coating amount of 20 to 200 g / m ² per unit area of the rubber component. Weaving dough for airbags with a polyester yarn having a fineness of 400 to 650 denier,
Refining the dough for the woven airbag, and
Tentering the refined fabric
A method for producing a polyester fabric according to any one of claims 1 to 10, including. The method of claim 11,
In the tentering step, the heat treatment temperature is 140 to 210 ℃ manufacturing method of the polyester fabric. A vehicle airbag comprising the polyester fabric according to any one of claims 1 to 10. The method of claim 13,
The airbag is a vehicle airbag is a frontal airbag or side curtain type airbag.

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