JPH06341030A - Base cloth for non-coat air bag - Google Patents

Abstract

PURPOSE:To provide the subject base cloth satisfying light weight, flexibility, compact foldability, mechanical properties and air-impermeability, etc., comparable to those of cloth produced by conventional technique, having excellent flame-retardancy and producible at a low cost by weaving with a water-jet loom having excellent weaving efficiency. CONSTITUTION:The high-density woven fabric for the base cloth of a non-coat air bag is made of nylon 66, nylon 6, nylon 46 or polyethylene terephthalate fiber. The oil to be applied to the fiber is a mixture produced by mixing (A) 50-65wt.% of a dibasic fatty acid ester compound containing 20-50wt.% of ethylene oxide having a molecular weight of 600-1,000, (B) 5-20wt.% of a polyether- type polymeric activation agent having a molecular weight of 1,000-5,000 and (C) 20-40wt.% of a polyalkylene glycol ester compound containing 25-55wt.% of diethylene oxide having a molecular weight of 600-1,000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base fabric for a non-coated airbag, and more specifically, for a non-coated airbag which is lightweight, flexible and has excellent storability as well as excellent breathability and flame retardancy. It relates to the base cloth.

[0002]

2. Description of the Related Art In recent years, an airbag has been rapidly installed as a vehicle occupant protection safety device.

Since an airbag is normally stored in a narrow space such as a steering wheel or an instrument panel, it is a required performance to reduce the storage volume.

Therefore, efforts have been made in the past for the airbag base fabric so as to have the best foldability and the smallest storage volume as far as the mechanical properties are satisfied.

For example, in the rubber-coated base cloth, the coating rubber is being changed from polychloroprene rubber to silicone rubber, which is because the silicone rubber can reduce the coating amount of the rubber coat and is flexible. This is because the rubber coated base fabric is completed.

On the other hand, in order to ensure the safety of the occupants of the automobile, it is desired to increase the wearing rate of the air bag. As one of the driving forces, it is possible to reduce the price of the entire air bag system. This is one of the performance requirements for airbags.

Therefore, further cost reduction of the air bag base cloth is taken up as an issue, and development of a non-coated base cloth having a high possibility of cost reduction is being promoted.

Further, the non-coated base fabric is advantageous from the viewpoints of softness, storability and lightness of the airbag base fabric, and there is a demand for early establishment of technology as a next-generation airbag base fabric.

[0009] As a previously proposed technique relating to a conventional non-coated airbag base fabric, for example, Japanese Patent Laid-Open No. 3-137245 is known.
JP-A-64-70247 and JP-A-3-70247.
Those described in, for example, JP-A-134245 are known.

That is, the technique disclosed in Japanese Patent Laid-Open No. 1-122752 discloses a high density woven fabric for controlling gas permeability, which is an important property as a base fabric for a non-coated airbag, and further shrinking and heat treatment. Disclosed is a base fabric for a non-coated airbag manufactured by applying a fixed calendar process or the like.

Further, in the technique described in JP-A-64-70247, the breathability is 5 cc / c by calendering a base fabric having a basis weight of 250 g / m ² or less.
Disclosed is a base fabric for a non-coated airbag of m ² / sec or less.

Further, the technique disclosed in Japanese Patent Application Laid-Open No. 3-134245 discloses a non-coated base cloth composed of a woven fabric having a symmetric structure subjected to calendar processing and having a fineness of 300 to 400 dtex and a high shrinkage yarn. Is.

However, all of the above-mentioned prior arts have shown that they are light-weight, flexible, excellent in storability, and sufficiently satisfy mechanical properties and non-permeability as a base fabric for non-coated airbags. However, it cannot be said that the heat resistance and the price reduction, which are important as the performance of the non-coated airbag base fabric, have been considered, and further improvements have been desired for the heat resistance and the price reduction.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems in the prior art. As a non-coated airbag base cloth, the same weight, flexibility, storability, and machine as in the prior art are provided. Of fabrics woven with a water jet loom (hereinafter referred to as WJL) that has excellent weaving efficiency in order to achieve excellent flame retardancy and cost reduction, as well as satisfying specific characteristics and non-breathability. The present invention is intended to provide a base fabric for a non-coated airbag.

[0015]

In order to achieve the above object, the base fabric for a non-coated airbag of the present invention has a cover factor of 2000 or more and an air flow rate of 0.5 cc / cm ^2.
A high-density woven fabric having a density of less than 1 / sec, and the oil content attached to the high-density fabric is less than 0.1% by weight.

The base fabric for a non-coated airbag of the present invention is characterized in that the high-density fabric is made of nylon 66, nylon 6, nylon 46 or polyethylene terephthalate fiber.

Further, in the base fabric for a non-coated airbag of the present invention, the component of the oil agent attached to the high-density fabric is 20 to 50 ethylene oxide having a molecular weight of 600 to 1000.
A divalent fatty acid ester compound (A) containing 100% by weight, a polyether-based polymer activator having a molecular weight of 1000 to 5000 (B), and a polyalkylene glycol ester compound containing 25 to 55% by weight of diethylene oxide having a molecular weight of 600 to 1000. (C), the above (A) is 5
It is characterized by comprising a mixture of 0 to 65% by weight, (B) 5 to 20% by weight, and (C) 20 to 40% by weight.

The fibers used for the non-airbag base fabric of the present invention are nylon 66, nylon 6, nylon 46 and polyethylene terephthalate fibers. Usually, fibers composed of a single polymer are preferable, but
It may contain 10% by weight or less of a copolymerization component. In particular, in the case of nylon 46 fiber, since it is difficult to form a yarn with a homopolymer as it is because of its high melting point and high crystallinity, a fiber containing about 5% by weight of a copolymer component is rather preferable.

The fibers used in the present invention are the mechanical properties of the base fabric for phosphorus-coated airbags, that is, the strength of the base fabric that can withstand the instantaneous expansion of gas, particularly impact strength, burst strength, tear strength, and expansion. In order to satisfy the energy to absorb the impact when the airbag hits the occupant, it is necessary to use a polymer with a high degree of polymerization. For example, in the case of nylon 66, nylon 6 or nylon 46 fiber, the relative viscosity of sulfuric acid is used. A polymer having an (ηr) of 3.0 or more and an intrinsic viscosity ([η]) of 0.8 or more in the case of polyethylene terephthalate is preferably used.

The base fabric for a non-coated airbag according to the present invention is intended to prevent thermal history during yarn production and thermal deterioration during storage and use as a product, light deterioration, oxidative deterioration, hydrolysis and the like. In the case of nylon 66, nylon 6 and nylon 46 fibers, it is preferable to add an antioxidant.

As the antioxidant, inorganic or organic acid copper such as copper iodide, copper bromide, copper chloride, copper acetate, copper pyrophosphate and copper stearate is added as copper in an amount of 10 to 3000 ppm, preferably 20 to 150 ppm. In addition, alkali metal halides such as potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium bromide, sodium chloride, lithium iodide, lithium bromide and lithium chloride,
Alternatively, a halogenated earth metal, a quaternary ammonium halide salt, or the like is contained in an amount of 0.05 to 0.5% by weight. Further, if necessary, an organic or inorganic phosphorus compound is contained as phosphorus in an amount of 10 to 500 ppm.

Further, in the case of polyethylene terephthalate fibers, for the purpose of preventing hydrolysis, carboxylic end groups 30 eq / 10 ⁶ or less, preferably 20 eq / 10 ⁶
The following is preferable. The polyethylene terephthalate fiber having a small number of carboxyl terminal groups can be obtained by adopting a low temperature polymerization method or a method of adding an end capping agent such as an epoxy compound, a carbodiimide compound and an oxazoline compound in a spinning step.

The fineness of the fiber used in the present invention is usually 6
It is not more than 00 denier, preferably not more than 500 denier. This is because the WJL suitable for weaving the base fabric for a non-coated airbag of the present invention is specified by the fineness that allows efficient weaving.

The base fabric for a non-coated airbag of the present invention is
Since the air permeability is 0.5 cc / cm ² / sec or less, it is a high density woven fabric having a cover factor of 2000 or more, preferably 2100 or more.

The cover factor as referred to in the present invention is a value obtained by the following formula from the product of the fabric constituent density and the square root of the fineness of the fiber yarn. K = Nw × Dw ^1/2 + NF × DF ^1/2 Nw: Warp density (pieces / inch) Dw: Warp denier NF: Weft density (pieces / inch) DF: Weft denier Further, the non-coated airbag base fabric of the present invention It is important that the oil agent remains less than 0.1% by weight.

Generally, an oil agent for synthetic fiber has an ignition point,
Since the ignition point is lower than that of the synthetic fiber itself, if 0.1% by weight or more of the residual oil agent is adhered, the flame retardancy of the non-coated base fabric may not be secured.

Since the base fabric for a non-coated airbag of the present invention is a high-density woven fabric which maintains the air permeability at a certain value or less as described above, once the woven fabric is woven with the oily agent attached, the oily agent in the woven fabric is removed. However, it cannot be sufficiently washed and removed even after the subsequent refining step. Therefore, it is preferable that the base fabric for a non-coated airbag of the present invention is woven by WJL that can wash the oil agent at the time of weaving. Further, it is important to select, as the oil agent attached to the raw yarn, one that is easily washed during WJL weaving.

The conditions required for the oil agent applied to the base fabric for a non-coated air bag of the present invention are that the friction between the yarn and the metal roll is small and the yarn is small so that yarn breakage and fluffing are less likely to occur. The friction between the threads is so strong that the oil film when the metal and the metal come into contact with each other under high tension is sufficiently strong, that the oil agent deposited on the heating rolls is less likely to undergo thermal oxidative decomposition, and that interlacing for focusing the filaments is likely to occur. It has a feature that it is reasonably high and that it is easy to wash in the WJL weaving process.

The following oil agents are applied to the base fabric for a non-coated airbag of the present invention as the oil agent satisfying the above conditions.

That is, a divalent fatty acid ester compound (A) containing 20 to 50% by weight of ethylene oxide having a molecular weight of 600 to 1000, a polyether polymer activator (B) having a molecular weight of 1000 to 5000, and a molecular weight of 60.
A polyalkylene glycol (hereinafter abbreviated as PEG) ester compound (C) containing 0 to 1000% of diethylene oxide in an amount of 25 to 55% by weight.
Is 50 to 65% by weight, (B) is 5 to 5% by weight, and (C) is 20 to 40% by weight.

More specifically, the divalent ester compound (A) includes 20 to 50% by weight of ethylene oxide having a molecular weight of 600 to 10,000, and specifically includes dioctyl alcohol EO ₃ adipate and dilauryl alcohol EO ₃ adipate. And adipic acid esters such as oleyl alcohol EO ₃ adipate, and thiodipropionic acid esters such as sebacate, dioctyl alcohol EO ₃ thiodipropionate and dioleyl alcohol EO ₃ thiodipropionate.

The polyether polymer activator (B) is
Molecular weight is 1000-5000, preferably 2000-3
000, for example, a compound selected from higher alcohol alkylene oxide adducts and polyhydric alcohol alkylene oxide adducts, and a nonionic activator obtained by reacting a monocarboxylic acid and / or a dicarboxylic acid.

The polyhydric alcohol alkylene oxide adduct is, for example, a polyhydric alcohol to which an alkylene oxide such as ethylene oxide, propylene oxide or butylene oxide is added. For example, hydrogenated castor oil ethylene oxide is added. , Castor oil ethylene oxide adduct, sorbitol ethylene oxide adduct, trimethylolpropane ethylene oxide adduct, and the like. Among them, hydrogenated castor oil ethylene oxide adduct, sorbitol ethylene oxide adduct or higher alcohol alkylene oxide adduct is preferable.

Further, specific examples of the monocarboxylic acid include caproic acid, capreic acid, lauric acid, palmitic acid, stearic acid, oleic acid and isostearic acid, and preferably palmitic acid, stearic acid, oleic acid and Examples include isostearic acid.

Specific examples of the dicarboxylic acid include maleic acid, adipic acid, thiodipropionic acid, sebacic acid, dodecanoic acid and brassylic acid.
Of these, maleic acid, adipic acid and propionic acid are preferred.

The PEG ester compound (C) has a molecular weight of 600 to 1000, and as the monocarboxylic acid which is esterified with diethylene glycol, caproic acid, capreic acid, lauric acid, palmitic acid, stearic acid,
Examples thereof include oleic acid and isostearic acid, preferably palmitic acid, stearic acid, oleic acid and isostearic acid.

The mixing ratio of the divalent fatty acid ester compound (A), the polyether polymer activator (B), and the PEG ester compound (C), which are the oil component according to the present invention, is such that the yarn production yield and the formation of fluff. It has important effects on the quantity, warp and passability of the weaving process, fabric quality.

Next, a method for manufacturing the base fabric for a non-coated airbag of the present invention will be described.

The base yarn for the non-coated airbag base fabric of the present invention is produced by melt spinning drawing of polyamide such as nylon 66, nylon 46, nylon 6 and polyethylene terephthalate polymer.

In the melt-spinning step, the polymer is melt-spun, and the oil agent is applied to the cooled and solidified yarn. The oil component is usually applied as a solution diluted with a low molecular weight mineral oil or water. The amount of oil on the fiber is 0.3-
It is 1.5% by weight, usually 0.5 to 1.0% by weight.

The yarn provided with the above oil agent is preferably continuously sent to the drawing step and subjected to the drawing heat treatment. For the stretching, a multi-stage hot stretching method with two or more stages is usually adopted. The drawn yarn is heat set and wound up, but immediately before winding up, the yarn is interlaced to bundle the filaments together.

The interlacing is performed by spraying a high-pressure fluid such as high-pressure air or steam from the outer circumference of the yarn through a nozzle.

A part of the raw yarn produced by the above method is sent to the warping step and rewound into a warping beam for warp,
A part of the yarn is prepared as weft and woven with WJL.

The base fabric for a non-coated airbag of the present invention is
So that the air flow rate is less than 0.5 CC / cm ² / sec,
A high-density woven fabric with a cover factor of 2000 or more.
For example, when weaving a plain weave using 420 denier nylon 66 raw yarn, the number of warp yarns and weft yarns is 50 or more per inch. More preferably, it is a high-density fabric having a cover factor of 2100 or more.

WJL is efficiently woven at a weft driving speed of about 1000 m / min or more, preferably 1200 m / min or more. Usually, most of the oil agent attached to the raw yarn is washed away during this weaving, and the residual oil content is less than 0.1% by weight. Since the oil agent applied to the raw yarn according to the present invention is composed of the above-mentioned specific oil agent component, it is easily washed and removed by water during WJL weaving, has a low hydroviscosity, and does not generate scum.

The woven raw material is sent to the heat setting step as it is without heat treatment, and heat set. In the heat-setting step, one or both sides may be calendered in order to control the air permeability of the non-coated airbag base fabric, or to control the feel and flexibility.

The air bag base fabric of the present invention produced by the above method has the following base fabric characteristics. (1) Cover factor (K) K ≧ 2000 (2) Tensile strength (S) S ≧ 160 kg / 3 cm (JIS K6328 5.3.5) (3) Elongation at break (E) 15 ≧ E ≧ 35% (JIS K6328 5.3.5) (4) Tear strength (TS) TS ≧ 15 kg (JIS K6328 5.3.6) (5) Permeation rate (P) P ≦ 0.5 cc / cm 2 / sec (JIS L1096 6.27A) Method) (6) Flammability (B) B ≦ 50 mm / min (FMVSS No. 302).

The non-coating airbag base fabric of the present invention having such characteristics is lightweight, flexible, has excellent storability and mechanical properties, and has practically sufficient performances in terms of non-breathability and flame retardancy.

In particular, compared with conventional chloroprene rubber-coated and silicone rubber-coated base fabrics for airbags, they are advantageous in terms of light weight, flexibility, and storability, but they have the advantage that they can be manufactured at a lower cost.

The non-coating airbag base fabric of the present invention having the above advantages can be used for both the driver's seat and the passenger's seat.

Next, the embodiments of the present invention will be specifically described with reference to examples.

[0052]

Examples 1 to 3 Sulfuric acid relative viscosity (sample concentration 1% by weight, 2
(5 ° C) is 3.5, and phosphorus is 100 pp as an antioxidant.
Nylon 66 chips containing m, 80 ppm of copper, and 0.1% by weight of potassium iodide were melted by an extruder type spinning machine. The molten polymer was filtered in a spin pack and spun through the spinneret pores. The base used had 72 fine holes with a diameter of 0.25 mm.

The spun yarn passed through the slow cooling zone immediately below the spinneret and was then cooled and solidified by cold air.

Next, to the above yarn, 55 parts by weight of dioctyl alcohol EO ₂ adiet, hardened castor oil E
OA molecular weight 2000 Thiodipropionate 10
A mixture obtained by mixing 30 parts by weight of PEG200 dioleate and 30 parts by weight of PEG200 dioleate (hereinafter referred to as oil agent No. 1) was applied with an oil agent diluted to 20% by weight with a higher hydrocarbon having a carbon number of C13, and then applied with a take-up roll. It was collected at a speed of 900 m / min.

Subsequently, while the yarn was stretched by 5% between the take-up roll and the yarn feeding roll, the same oil agent as the above was applied as the undiluted solution. The oil agent was applied so as to be about 1% by weight with respect to the raw yarn, about 0.2% by weight before the take-up roll, and the rest was applied between the take-up roll and the yarn feeding roll.

Next, the above yarn was sent to the drawing step and continuously drawn. The stretching heat treatment was carried out by a one-stage relaxation treatment method after two-stage hot stretching. The take-up roll was not heated, the yarn feeding roll was 60 ° C., the first drawing roll temperature was 120 ° C., and the second drawing roll temperature was 240 ° C. The relaxing roll after stretching is 12
It was set to 0 ° C.

Further, between the take-up roll and the yarn feeding roll,
While stretching 5%, a mixed non-aqueous oil agent comprising a smoothing agent, an activator and a trace amount of extreme pressure agent, an antistatic agent and an additive such as an antioxidant is attached to the drawn fiber by about 1%. So granted.

The draw ratio was 3.56 for the first step and 1.25 for the second step, and the relaxation rate was 8%. Immediately before winding, an interlace was wound so that the number of entanglements was about 40 per 1 m.

The raw yarn obtained by the above method is 420D-
The strength was 72 fil, the strength was 9.6 g / d, the elongation was 22%, the boiling water shrinkage ratio was 6.0%, and the number of fluff was 2.2 per 10 million m.

A part of this raw yarn was used as a warp beam having 2100 warp yarns. Weaving was performed using WJL manufactured by Tsuda Koma Co., Ltd., and weaving was performed at a weft driving speed of 1000 m / min.

The greige machine was heat set as it was at 180 ° C. without going through the refining step to obtain a non-airbag machine cloth (Example-1).

Further, by changing the weaving conditions as shown in Table 1, two more kinds of non-coated airbag fabrics were obtained (Examples-2 and -3).

Table 2 shows the results of evaluating the performance of the obtained non-coated airbag base fabrics as airbag fabrics.

[0064]

[Comparative Examples 1 to 4] When the weaving conditions of Example-1 were changed as shown in Table 1 (Comparative Example-1), the raw yarn was spun in the same manner as in Example-2, and the loom type was changed to rapier. In the case of (Comparative Example-2), the oil agent component of Example-2 was added to dioleyl adipate: 60 parts by weight, sorbitol EOA molecular weight: 8
50:20 parts by weight, and PEG 200 diolate: 2
When the mixture was changed to a mixture of 0 parts by weight (oil agent No. 2) and the warping oil agent was added in the warping step, (Comparative Example-3) and the same oil agent as Comparative Example-3 When used with a rapier loom (Comparative Example-
Table 2 also shows the results of evaluating the properties of the respective airbag base fabrics obtained in 4).

In Example-3, Comparative Example-2 and Comparative Example-3, a refining step was performed to remove the oil agent. The scouring was carried out by passing it through a 70 ° C. hot bath containing a scouring agent for 2 minutes.

[0066]

[Table 1]

[Table 2] As is clear from the results of Table 1 and Table 2, in the case of a high-density woven fabric having an air permeability of less than 0.5 cc / cm ² / sec, the oil agent specified in the present invention is applied and it is limited to the case of weaving with WJL. The residual oil content is 0.1% by weight or less,
A base fabric for non-coated airbags having excellent flame retardancy can be obtained.

[0067]

As described above, the base fabric for a non-coated airbag of the present invention has mechanical properties equivalent to those of the conventional polychloroprene rubber-coated base fabric and silicone rubber-coated base fabric, and for airbags. Since it has practically sufficient non-breathability and flame retardancy as a base fabric, it can be preferably used in place of the conventional rubber-coated base fabric.

The base fabric for a non-coated airbag of the present invention is
Compared with conventional rubber-coated base cloth, it is lighter, more flexible, and has better storability. It is woven with more efficient WJL and does not require a rubber coat. Have.

That is, since the non-coated airbag base fabric of the present invention is advantageous in both of the above-mentioned excellent performance and low manufacturing cost, in order to improve the airbag wearing rate which is desired for protecting passengers of an automobile, It can contribute favorably.

Claims (3)

[Claims] 1. A high-density woven fabric having a cover factor of 2000 or more and an air flow rate of less than 0.5 cc / cm ² / sec, wherein the oil content attached to the high-density woven fabric is 0.1% by weight.
The base fabric for a non-coated airbag, which is less than 2. The base fabric for an airbag according to claim 1, wherein the high-density fabric is made of nylon 66, nylon 6, nylon 46 or polyethylene terephthalate fiber. 3. The component of the oil agent adhering to the high-density fabric is ethylene oxide having a molecular weight of 600 to 1,000.
A divalent fatty acid ester compound (A) containing 0 to 50% by weight, a polyether polymer activator (B) having a molecular weight of 1000 to 5000, and a polyalkylene containing 25 to 55% by weight of diethylene oxide having a molecular weight of 600 to 1000. It is composed of a glycol ester compound (C), which is a mixture of 50 to 65% by weight of (A), 5 to 20% by weight of (B), and 20 to 40% by weight of (C). The base fabric for a non-coated airbag according to claim 1 or 2.