JPH1060750A - Base cloth for non-coated air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain base cloth for non-coated air bag having low air permeability and excellent fire retardancy and durability by weaving specific nylon-6 multifilament and applying a specific heat-resistant smoothing agent. SOLUTION: This base cloth for non-coated air bag having >=2,100 cover factor, <=20cc/cm<2> /sec air permeability and >=18kgf tearing strength after a heat-resistant test at 120 deg.C for 400hrs with >=90% retention is obtained as following. Nylon-6 multifilament yarn having >=9.1g/d strength, >=20% elongation, <=500de total denier and <=5de single fiber denier is formed by subjecting nylon-6 having >=3.3 relative viscosity and <=42mol/ton amino terminal group amount and containing a copper compound such as copper iodide to melt spinning and drawing. The resultant nylon yarn is used to warp and weft to weave woven cloth, scoured and dried, then <=0.2% heat-resistant smoothing agent containing dialkylthiodipropionate and polyoxyethylene castor oil alkylate.ethylene oxide castor oil alkylate copolymer as main components is applied to the resultant woven cloth to obtain the objective base cloth.

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 an air bag installed for the safety of a vehicle occupant, and more particularly, to a lightweight, flexible, compact, and physical fabric. The present invention relates to an airbag base fabric having improved mechanical properties, tear strength after heat resistance test and air permeability.

[0002]

2. Description of the Related Art The mounting of airbags as an occupant security device for automobiles is advancing, and the production of modules including an inflator case is being adopted for the driver's seat and the passenger's seat from the delivery form mainly of a single bag. In order to be stored in a narrow place, compactness is required.

[0003] As a base fabric for an air bag, a soft base fabric that satisfies physical performance, and is foldable, compact, and does not cause facial injury has been required. A non-coated type, which does not perform coating, is being adopted from a coating type in which chloroprene rubber or silicon rubber is coated as a base cloth. The problem of the non-coated airbag fabric is to improve the low air permeability and flame retardancy to a level that can be used practically as in the case of the coating type airbag fabric, while maintaining the above performance.

[0004] Many proposals regarding non-coated airbags have been made in the past, and typical techniques include JP-A-4-2835, JP-A-7-90747, and JP-A-1-70247. . JP-A-4-
Japanese Patent No. 2835 proposes a technique of processing a cloth made of polyester fiber with a calendar to obtain a low air permeability. Japanese Patent Application Laid-Open No. 7-90747 discloses a technique of weaving at a high density to obtain a low air permeability. In addition, a technique for improving tear strength has been disclosed. Japanese Patent Application Laid-Open No. 1-70247 discloses a non-coated air bag in which the air permeability is 5 cc / cm ² / sec or less by calendering a base fabric having a basis weight of 250 g / cm ² . They are,
Compared to the conventional base fabric for coating type airbags, it is superior in lightness, compactness and flexibility, indicating that it can be put to practical use.

[0005] However, the base fabric for an airbag is naturally required to be installed in an automobile for a long period of time and to exhibit its performance instantaneously in the event of an accident.
It is expected that the temperature inside the vehicle will be 80 ° C. or higher, which causes a problem of heat resistance deterioration, particularly a decrease in tear strength. Compactness,
In order to meet these demands, it is most advantageous to use a fiber with a fineness of a single yarn to make a high-density fabric. Although studies have been made to reduce total denier and single yarn denier, tear strength is remarkably reduced as fineness is reduced. It is difficult to reduce the fineness, secure the desired tear strength, and obtain performance that can be used for a long period of time.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an excellent foldability, compactness, and light weight, and An object of the present invention is to provide a base fabric for a high density woven non-coated air bag having improved tear strength.

[0007]

DISCLOSURE OF THE INVENTION The present invention attains the above object and has a relative viscosity of ηrel of 3.3 or more, an amino terminal group content of 42 mol / ton or less, and a copper compound of 0.1 mol or less.
Containing from 0.1 to 0.1% by weight, having a strength of 9.5 g / d or more,
It is made of nylon 6 fiber yarn with elongation of 20% or more,
Cover factor is 2100 or more, air permeability is 20cc / cm
² / sec or less, coated with a heat-resistant smoothing agent, and has a tear strength of 18 kg after a heat test (120 ° C x 400 hours).
f The gist of the present invention is a non-coated airbag base fabric, wherein the retention rate in a heat resistance test is 90% or more.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The base fabric for a non-coated airbag of the present invention is excellent in lightness, flexibility, and storability, has high tear strength, and has excellent performance in maintaining a tear strength after a heat test, and has low air permeability, It is characterized by flame retardancy.

The base fabric for a non-coated air bag of the present invention is made of nylon 6 fiber yarn, and this yarn has a relative viscosity η.
rel is 3.3 or more, the amount of amino terminal groups is 42 mol / ton or less, and it is composed of high polymerization degree nylon 6 containing 0.01 to 0.1% by weight of a copper compound, and has a strength of 9.5 g / d or more. And the elongation is 20% or more. Relative viscosity ηre of nylon 6
When l is 3.3 or less or the amount of amino terminal groups is 42 mol / ton or more, it is difficult to obtain a desired fiber strength.
Decomposition occurs over a long period of use, and the deterioration of physical properties increases.

[0010] By containing a copper compound, these highly polymerized nylons have improved heat resistance and a high retention of tear strength after a heat test. The copper compound content is 0.01
To 0.1% by weight. Copper compounds include copper iodide,
Copper bromide, copper chloride, copper acetate, and copper stearate can be used. When the content of the copper compound is less than 0.01% by weight, the effect as a countermeasure against heat deterioration is poor.
Even if the content exceeds 1% by weight, the effect on heat deterioration does not change, and if the content increases, the strength of the fiber decreases, so the content is 0.02 to 0.05% by weight. preferable.

By increasing the fiber yarn strength to 9.5 g / d or more and elongation to 20% or more, the tear strength is improved, and the desired physical properties can be cleared and the weight can be reduced. Become.

The base fabric for a non-coated air bag according to the present invention has a test differential pressure of 19.6 KPa and a high pressure method having an air permeability of 20 cc / cm.
It is a low-permeability woven fabric of cm ² / sec or less, and a high-density woven fabric having a cover factor of 2100 or more, preferably 2200 or more. Here, the cover factor (K) is a value determined by the following equation from the product of the density of the woven fabric and the square root of the fineness of the fiber yarn.

K = K _W × D _W ^1/2 + K _F × D _F ^1/2 where K _W : warp density (book / inch) D _W : warp fineness (denier) K _F : weft density (book / inch) ) D _F : Weft fineness (denier)

For example, when weaving with a plain weave using 420 denier nylon 6 fiber yarns,
52 or more per inch, preferably 53
A high-density woven fabric of at least one woven fabric, and the ratio of the number of warps and wefts is preferably about 1: 1 depending on the purpose of use.

The burst strength is important in the physical properties of the airbag, and the burst strength and the tear strength are in a proportional relationship. In order to improve the tear strength, it is effective to increase the fineness, but it is in the opposite direction to the light weight, flexibility, and compactness targeted in the present application. Therefore, it improves the slipperiness between the fibers and between the fibers, and does not break with each fiber thread of the fabric and the weft constituting the woven fabric, but slides the load applied to the fabric, and the two and three fibers are bundled and cut. The formula is important to achieve the goal.

The base fabric for a non-coated air bag of the present invention is coated with a heat-resistant leveling agent. Dialkylthiodipropionate and polyoxyethylene castor oil alkylate are heat-resistant smoothing agents that have excellent smoothness, do not volatilize even in a high-temperature atmosphere, have flame retardancy, and can be easily applied to fibers. It is effective to use an ethylene oxide castor oil alkylate copolymer as a main component, and the mixing ratio is suitably about 6: 4 in consideration of emulsifiability and flame retardancy, but is not limited thereto.

As a method of coating with a heat-resistant smoothing agent, the above composition is dispersed and emulsified in water, and applied in any process such as applying with a spinning oil agent in a fiber production stage or applying after weaving a woven fabric. A commonly used method such as a roll method, a pad method, and a spray method can be used as the applying method. If necessary, an antistatic agent, an emulsifier, a decomposition inhibitor, and other additives can be used in the composition. The amount of these additives is preferably 5% by weight or less in consideration of smoothness and flame retardancy.

The amount of the heat-resistant smoothing agent adhered to the fiber is set to 0.1.
The content is preferably from 0.2 to 0.2%, and if it is less than 0.02%, it is difficult to obtain sufficient smoothness. If it exceeds 0.2%, the effect is not improved even if it is added more, and the surface is sticky. May cause problems such as fogging the window glass of automobiles and impairing flame retardancy. 0.05-0.15%
More preferably,

As the antistatic agent, the emulsifier and the antioxidant, commercially available ones can be used.
As a decomposition inhibitor, a triazine compound is effective.

The fineness of the fiber yarn is more advantageous in terms of flexibility, light weight and compactness, but a level that satisfies the physical performance of the base fabric is required. The fineness of the yarn constituting the base fabric for a non-coated air bag according to the present invention is 50
0 denier or less. This fineness is the upper limit at which weaving can be performed efficiently in a water jet room or air jet room. The single yarn fineness is 5 deniers or less.
The finer the fineness of the single yarn is, the better the flexibility and compactness are. However, there is a problem that the tear strength is reduced.
In general, the tear strength of the woven fabric decreases as the single-filament fineness of the yarn decreases, and the tear strength decreases as the smooth component attached to the woven fabric decreases and the friction increases. Therefore, in order to prevent such a decrease in tear strength, it is effective to apply a smooth and sizing agent to the yarn and the woven fabric.

The base fabric for a non-coated air bag of the present invention is a high-density woven fabric having a cover factor of 2100 or more. If the cover factor is less than 2100, desired low air permeability cannot be obtained. The woven machine is sent to a heat setting step after a scouring step and the application of a heat-resistant smoothing agent, if necessary, and is heat-set.

[0022]

The present invention will be described below in detail with reference to examples. In the examples, the airbag fabric was evaluated by the following method. 1. Density (books / inch) JIS L-1096 2. Weight (g / m ² ) JIS K-6328 3. Thickness (mm) JIS K-6328 4. Strength (kgf / 3cm) JIS K-6328 5. Elongation (%) JIS K-6328 6. 6. Tear strength (kgf) JIS K-6328, single tongue method 7. Softness (mm) JIS L-1096 8. Air permeability (cc / cm ² / min) High pressure method with test differential pressure of 19.6KPa 10. Residual oil content (%) JIS L-1096 10. Flame retardancy (mm / min) FMVSS302 method (pass 60mm / min or less) Heat resistance test After leaving to stand in a hot air dryer at 120 ° C for 400 hours, measure the tear strength

Example 1 Relative viscosity ηrel is 3.7, amino terminal group is 36 mol / ton
Then, a nylon 6 chip containing 0.03% by weight of copper iodide is melt-spun with an extruder-type spinning machine and stretched.
420 denier 96 filaments with a strength of 9.7 g / denier and an elongation of 23.5% (single yarn fineness 4.375 denier)
And use this yarn as the warp yarn to obtain the fabric density (warp ×
Wet) 55 × 55 lines / inch design, 600rpm / min
Weaving in a water jet loom made by Tsuda Koma, scouring and drying with an open soaper, heat-resistant smoothing agent EN-760
0-1 [(main component) dialkylthiodipropionate:
60 parts, polyoxyethylene castor oil alkylate-ethylene oxide castor oil alkylate copolymer: 35
Parts, triazine-based compound: 5 parts, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.] in a solution prepared to have an active ingredient (solid content) concentration of 2 g / liter, squeezed with a mangle to a 50% squeezing rate, and dried. After that, heat setting is performed, and the warp density is 55 lines / inch and the weft density is 55 lines / inch (cover factor 2
254) The base fabric for a non-coated air bag of the present invention was obtained.

Comparative Example 1 In Example 1, the relative viscosity ηrel was changed to a nylon 6 chip having a relative viscosity ηrel of 3.7, an amino terminal group of 36 mol / ton, and containing 0.03% by weight of copper iodide. 3.
2.Examples except that weaving was performed using 420 denier 96 filaments having a strength of 8.5 g / denier and an elongation of 25.3% using nylon 6 chips having 46 mol / ton amino terminal groups and containing no copper compound. In the same manner as in Example 1, a base fabric for a non-coated air bag of a comparative example was obtained.

Comparative Example 2 In Example 1, the relative viscosity ηrel was changed to a nylon 6 chip having a relative viscosity ηrel of 3.7, an amino terminal group of 36 mol / ton, and containing 0.03% by weight of copper iodide. 3.
7. Example except that weaving was performed using 420 denier 96 filaments having a strength of 9.7 g / denier and an elongation of 23.5% using nylon 6 chips having 36 mol / ton amino terminal groups and containing no copper compound. In the same manner as in Example 1, a base fabric for a non-coated air bag of a comparative example was obtained.

Comparative Example 3 In Example 1, the relative viscosity ηrel was changed to a nylon 6 chip having a relative viscosity ηrel of 3.7, an amino terminal group of 36 mol / ton, and containing 0.03% by weight of copper iodide. 3.
7. The amino terminal group is 36 mol / ton and copper iodide is 0.2
Using nylon 6 chip containing 5% by weight, strength 9.1
A non-coated airbag base fabric of a comparative example was obtained in the same manner as in Example 1 except that weaving was performed using 420 denier 96 filaments having a g / denier of 16% and an elongation of 16%. Table 1 shows the evaluation results of the obtained non-coated airbag base fabrics of Example 1 and Comparative Examples 1 to 3.

[0027]

[Table 1]

As is clear from Table 1, Example 1 of the present invention is satisfactory in air permeability, tensile strength and tear strength as a base fabric for an airbag, and shows little deterioration in a heat resistance test. On the other hand, Comparative Examples 1 and 2, which are made of nylon fiber yarns containing no copper compound, show a large deterioration in the heat resistance test, and Comparative Example 3, which contains too much copper compound, shows a nylon fiber yarn. Since the strength of the strip is low, the tensile strength and tear strength of the base fabric are low.

Comparative Example 4 In order to compare the heat-resistant smoothing agent with the method of the present invention, the heat-resistant smoothing agent EN-7600-1 in Example 1 was heat-set without adding the same, and the base fabric for a non-coated air bag of the comparative example was heat-set. I got

Comparative Example 5 In order to compare the heat-resistant smoothing agent with the method of the present invention, in Example 1, the heat-resistant smoothing agent EN-7600-1 was used instead.
A non-coated airbag base fabric of a comparative example was obtained in the same manner as in Example 1 except that Sun Silicon 1500 (silicone-based oil agent: manufactured by Sanyo Chemical Co., Ltd.) was applied.

Comparative Example 6 In order to compare the heat-resistant smoothing agent with the method of the present invention, the heat-resistant smoothing agent in Example 1 was replaced with EN-7600-1.
A non-coated airbag base fabric of a comparative example was obtained in the same manner as in Example 1 except that Solol T-110 (oil oil blended with mineral oil: manufactured by Kao Corporation) was applied.

Comparative Example 7 In order to compare the heat-resistant smoothing agent with the method of the present invention, in Example 1, the heat-resistant smoothing agent was replaced with EN-7600-1.
A non-coated airbag base fabric of a comparative example was obtained in the same manner as in Example 1 except that Pohinal K-140 (high melting point wax: manufactured by Issha Co., Ltd.) was applied. The evaluation results of Comparative Examples 4 to 7 are shown in Table 2 together with Example 1.

[0033]

[Table 2]

As is clear from Table 2, Comparative Example 4 in which the base fabric was not provided with a smoothing agent and Comparative Examples 5 to 7 in which a smoothing agent which could not be regarded as a heat-resistant smoothing agent were all torn in the heat resistance test. The strength was greatly deteriorated, and the durability was a concern.

[0035]

The base fabric for an air bag according to the present invention has physical properties equivalent to those of the conventional coating type, and has practically sufficient low air permeability and flame retardancy as a base fabric for an air bag. Excellent in lightness, flexibility and compactness,
It is possible to provide a durable air bag which has almost no decrease in tear strength after an aging test.

Continued on the front page (72) Inventor Yoshihisa Karatari 23 Uji Kozakura, Uji-city, Kyoto Pref.

Claims (3)

[Claims] 1. A copper compound having a relative viscosity of ηrel 3.3 or more, an amino terminal group amount of 42 mol / ton or less and a copper compound of 0.01 to
0.1% by weight, strength: 9.5 g / d or more, elongation: 20% or more, made of nylon 6 fiber yarn, cover factor: 2100 or more, air permeability: 20 cc / cm ² / se
c Below, covered with a heat-resistant smoothing agent and subjected to a heat resistance test (1
A base fabric for a non-coated airbag, characterized in that a tear strength after treatment at 20 ° C for 400 hours) is 18 kgf or more and a retention rate in a heat test is 90% or more. 2. A heat-resistant leveling agent comprising a dialkylthiodipropionate and a polyoxyethylene castor oil alkylate-ethylene oxide castor oil alkylate copolymer as main components. The base fabric for a non-coated air bag according to claim 1. 3. The nylon 6 fiber yarn has a fineness of 500 denier or less and a single yarn fineness of 5 denier or less.
Or the base fabric for a non-coated air bag according to claim 2.