JP2000190812A - Synthetic fiber for seat belt, and seat belt webbing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic fiber for a seat belt whose rigidity in the latitude direction is improved and a seat belt webbing which is excellent in rigidity, in particular rigidity in the latitude direction and has stable storing properties and hardly makes the seat belt turn over, and can protect the occupants surely from an accident if they should encounter it and which is rich in dirt resistance. SOLUTION: This synthetic fiber is composed of the mono-filament with a triangle or Y shape section. In this case, the deformation degree (H) of the section shape is 1.5-4.0. In the seat belt webbing, the synthetic fiber for seat belt is used as a latitude yarn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic fiber for a seat belt and a seat belt webbing, and more particularly, to a synthetic fiber for a seat belt having improved rigidity in a weft direction as compared with a conventional synthetic fiber, and particularly to a weft. The seat belt has excellent directional rigidity, has stable storage properties, is unlikely to cause inversion of the seat belt, can reliably protect the occupant in the event of an accident, and is highly antifouling. It is about webbing.

[0002]

2. Description of the Related Art Generally, a three-point seat belt webbing used in a front seat of a passenger car or the like can be smoothly pulled out from a retractor when worn, and can be stored in a retractor naturally when detached. Performance is required.

[0003] As means for satisfying these required performances, slipperiness is improved by reducing the thickness of the seatbelt webbing as much as possible or by subjecting the surface of the seatbelt webbing to resin processing or the like. Methods to improve the storage properties have been studied,
For example, U.S. Pat. No. 4,107,371,
It has been proposed in, for example, JP-A-5-116831 and JP-B-4-66984.

That is, US Pat. No. 4,107,371
The method described in the specification describes that a synthetic resin monofilament is used as the weft constituting the webbing for the seatbelt, and according to this method, the rigidity in the weft direction of the webbing for the seatbelt is improved. As a result, it is possible to suppress the reversal at the time of pulling out or winding up by the slip guide, so that it is possible to obtain the effect of improving the retractability in the retractor. But,
When a monofilament is used as the weft of the seat belt webbing, the rigidity of the monofilament itself is large, so that the driving property during weaving is poor, and the weaving property is significantly reduced. .

The method described in Japanese Patent Application Laid-Open No. 55-11683 is characterized by adding a thermosetting resin to the weft yarn in order to improve the rigidity of the seat belt webbing in the weft direction. According to this method, the initial stiffness in the weft direction is certainly improved, but when the seat belt webbing is repeatedly subjected to bending fatigue, the applied thermosetting resin is destroyed, and the stiffness in the weft direction is greatly reduced. There was sometimes.

Further, the method described in Japanese Patent Publication No. 4-66984 discloses a method of improving slip resistance with a slip guide or the like by applying a specific resin to the surface of a seat belt webbing and storing the sheet in a retractor. It is characterized by improving the performance. According to this method, although the initial storability is certainly improved, when used for a long period of time, the resin applied to the surface is scraped off and falls off, so that the slip resistance gradually decreases, and accordingly In some cases, the storability also deteriorated.

Japanese Patent Application Laid-Open No. Hei 7-228218 proposes a seat belt webbing using synthetic fibers having a non-circular cross section as the weft. Although the rigidity in the latitudinal direction is improved, there are some that have little effect on the rigidity in the latitudinal direction depending on the cross-sectional shape and the fineness of the fiber, and the weaving property of the webbing is poor.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems in the prior art.
Has been achieved.

Accordingly, an object of the present invention is to provide a synthetic fiber for a seat belt having improved rigidity in the latitudinal direction as compared with the related art, and a rigidity, particularly, a rigidity in the latitudinal direction which is excellent, has a stable storage property, and has an inverted seat belt. Another object of the present invention is to provide a seat belt webbing that can protect an occupant reliably in the event of an accident, and is highly antifouling.

[0010]

In order to solve the above-mentioned problems, the synthetic fiber for a seat belt of the present invention mainly has the following constitution. That is, the synthetic fiber is a synthetic fiber having a triangular or Y-shaped monofilament in cross section, and the degree of deformation (H) of the cross section is 1.5 to 4.0. .

In the synthetic fiber for a seat belt of the present invention, the monofilament is a hollow fiber;
The fineness of the monofilament is 200 to 1700 denier, the strength is 4.0 g / d or more, the synthetic fiber is made of a soaked yarn, the synthetic fiber is treated with a resin or a treating agent, and It is a preferable condition that the synthetic fiber is made of a polyester having ethylene terephthalate as a main repeating unit. By applying these conditions, it is possible to expect a further excellent effect.

The seat belt webbing of the present invention mainly has the following configuration. That is, a seatbelt webbing characterized in that the synthetic fiber for a seatbelt is used as a weft.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below.

It is important that the synthetic fiber used for the seat belt in the present invention has a triangular or Y-shaped cross section.

That is, by making the cross section of the fiber triangular or Y-shaped, when the cross section of the single fiber is the same,
The bending stiffness of the single fiber is higher than that of a fiber having a normal circular cross section, and as a result, the stiffness of the webbing is higher.

However, in the synthetic fibers used in the present invention which are made of monofilaments having a triangular or Y-shaped cross section, the degree of deformation (H) of the cross section is 1.5 to 4.0, preferably 1.7 to 4.0. It is important to be in the range of 3.8. If the degree of deformation (H) of the cross-sectional shape is less than 1.5, the webbing rigidity cannot be obtained. On the other hand, if it exceeds 4.0, the single fiber breaks during spinning-drawing and the quality deteriorates. .

The monofilament of the present invention is preferably used by using a hollow fiber because a belt having excellent antifouling property and light weight can be provided.

Further, the fineness (D) of the synthetic fiber for a seat belt of the present invention is 200 to 1700 denier;
At the same time, the strength is preferably at least 4.0 g / d.
When the thickness is within these ranges, the webbing can have high strength so as to withstand the impact of a vehicle collision for the purpose of protecting the occupant when the webbing is formed. It can be pulled out smoothly from the retractor and can be stored smoothly in the retractor when removed.

Further, the synthetic fiber for a seat belt of the present invention is preferably made of original yarn, since it is recyclable and has excellent light fastness. As a method of soaking, for example, a method of adding a coloring agent in an esterification step for polyester polycondensation, which is a material polymer, or a transesterification step, or a polycondensation reaction step, a method of spinning by blending a coloring agent during chip drying , A method of directly adding a colorant during spinning, a method of melting a master chip containing a high concentration of a colorant, blending with a separately melted base polymer and spinning (melt blending method), and a method of high-concentration of a colorant. Method of spinning by blending the contained master chip and base chip (chip blending method)
Conventionally known addition techniques such as can be applied, and any colorant addition time can be selected, but in consideration of fiber quality, operation stability and production cost, among others, chips using a master chip The use of a blending method is preferred.

In addition, the synthetic fiber for a seat belt of the present invention is preferably subjected to a low friction treatment with a low friction treatment agent. That is, by performing the friction reduction processing, it is possible to maintain the storage stability of the seat belt webbing satisfactorily. As the low friction treatment agent used here, a treatment agent containing a polyether compound having a molecular weight of 1,000 to 3,000 is preferable. As a method of applying the friction-reducing agent, it can be applied at any position after spinning and before winding. As a specific application method, for example, a method in which a low friction treatment agent is mixed with a spinning oil and applied, and a method in which the agent is applied immediately before winding are exemplified. Alternatively, the webbing may be applied after weaving the seatbelt yarn to form webbing. Specifically, for example, a method in which the webbing is immersed in a solution of the low friction processing agent, a method in which the solution of the low friction processing agent is sprayed on the webbing surface, and the like can be arbitrarily selected.

Examples of the material polymer for the seatbelt fiber of the present invention include polyester and polyamide, and polyester is preferably used from the viewpoint of initial modulus and terminal modulus. As the type of polyester, particularly, polyester having ethylene terephthalate as a main repeating unit, that is, polyethylene terephthalate is preferably used. In the polyethylene terephthalate, a conventionally known acid component and glycol component may be copolymerized as long as the constitutional requirements and objects of the present invention are not impaired, and specific examples of the acid component include isophthalic acid and adipic acid. However, specific examples of the glycol component include tetramethylene glycol, 1,4
-Cyclohexane dimethanol and polyethylene glycol.

The synthetic fiber for a seat belt of the present invention can be obtained by a usual spinning method. For example, a polyester base chip and a master chip are weighed and mixed, respectively, and the mixed chip is supplied to an extruder to form a molten polymer and spun from a die having a Y-shaped hole.

Thereafter, the mixture is once cooled, and heated at 110 to 130 ° C. for 4 hours.
Stretched 5 times to 5 times, 0.7 times at 180 ° C to 200 ° C
It can be obtained by performing a relaxation heat treatment at 0.9 times.

The seatbelt webbing of the present invention can be obtained by weaving the synthetic fiber for a seatbelt having the above structure as a weft and weaving it by a usual weaving method.
The warp is not particularly limited, and synthetic fibers having a normal circular cross section can be used. In this case, as the warp material, it is desirable to use a polyester mainly composed of polyethylene terephthalate as in the case of the weft.

The webbing for a seat belt of the present invention having the above-mentioned structure has a cross-sectional shape of a synthetic fiber constituting the webbing.
Since the degree of deformation (H) is specified in a specific range, the rigidity in the weft direction is further improved as compared with the conventional webbing for a seat belt, and has a stable storage property and hardly causes the seat belt to be inverted. In the event that an accident is encountered, the occupants can be reliably protected.

[0026]

Next, the present invention will be described in detail with reference to examples. Each measurement value in the examples was measured according to the following method.

[Deformation (H)] A section of a single fiber cross section was prepared by a copper plate method, and the radius (r) of the inscribed circle and the radius (R) of the circumscribed circle of the single fiber cross section were measured with an optical microscope. The degree of deformation (H) was determined by calculation using R / r.

[Strength] The strength was measured according to JIS L 1017 using a Tensilon tensile tester manufactured by Orientec.

[Static Tensile Strength, Static Tensile Elongation] Using a tensile tester “Tensilon” manufactured by Orientec, JI
It was measured according to SL 1079, 6.12.

[Bending rigidity in the weft direction] Using a rigidity tester (Model 150-B) manufactured by Taper Inc., USA, a width of 50 cm
It was measured under the condition of a length of 100 cm.

(Examples 1 to 4, Comparative Examples 1 to 5) A polyethylene terephthalate chip was melted and melt-spun from a die having a non-circular hole, ie, a Y-shaped hole or a triangular-shaped hole.

In Comparative Example 1, the fiber was spun from a die having a circular hole.

Thereafter, the mixture is once cooled, and further cooled at 120 ° C.
After stretching 7 times, the polyester was subjected to relaxation heat setting at 190 ° C and 0.9 times to obtain a polyester monofilament.

The fineness of the synthetic fiber thus obtained,
The strength is shown in Table 1.

Further, the obtained synthetic fibers were wound with a needle loom at a weft driving number of 20 yarns / inch and a warp driving number of 39 yarns.
Weaving was performed under the condition of 0 yarns / inch, and then heat setting was applied to obtain a seat belt webbing having the configuration shown in Table 1. In this case, the warp has a fineness of 1
A 500-denier polyester monofilament (strength 9.5 g / d, elongation 12%) was used.

Table 1 also shows the static tensile strength (ton), static tensile elongation (%) and bending stiffness in the weft direction (g / cm) of the obtained seat belt webbing.

[0037]

[Table 1] As is evident from the results in Table 1, the seatbelt webbing of the present invention (Examples 1 to 4) using a synthetic fiber having a triangular or Y-shaped non-circular cross-sectional shape is a conventional seatbelt webbing having a circular cross-section. The rigidity in the latitudinal direction is greatly improved as compared with.

[0038]

As described above, the synthetic fiber for a seat belt of the present invention has a further improved rigidity in the weft direction than before, and the synthetic fiber for a seat belt of the present invention using this synthetic fiber for a seat belt as a weft yarn. Compared to conventional seatbelt webbing, the seatbelt webbing has significantly improved rigidity, particularly in the weft direction, and has a stable retractability in the retractor. If an accident is encountered, the occupants can be reliably protected. Further, the antifouling property of the seat belt is also improved.

Continued on the front page F-term (reference) 3D018 BA01 BA04 4L035 AA09 BB31 BB89 BB91 CC02 CC07 DD02 DD05 DD14 EE08 FF01 FF10 4L045 AA05 BA01 BA13 BA14 BA49 BA60 DA42 4L048 AA21 AA34 AA37 AA39 AA48 CAA10 CA12 CA15 EA00 EB05

Claims (7)

[Claims] 1. A synthetic fiber comprising a triangular or Y-shaped monofilament having a cross-sectional shape of 1.5 to 4.0, wherein said cross-sectional shape has a degree of deformation (H) of 1.5 to 4.0. fiber. 2. The synthetic fiber for a seat belt according to claim 1, wherein said monofilament is a hollow fiber. 3. The monofilament has a fineness of 200 to 200.
The synthetic fiber for a seat belt according to claim 1, wherein the fiber has a denier of 1700 and a strength of 4.0 g / d or more. 4. The synthetic fiber for a seat belt according to claim 1, wherein the synthetic fiber is made of a native yarn. 5. The synthetic fiber for a seat belt according to claim 1, wherein the synthetic fiber is treated with a resin or a treatment agent. 6. The synthetic fiber for a seat belt according to claim 1, wherein the synthetic fiber is made of polyester having ethylene terephthalate as a main repeating unit. 7. A seat belt webbing using the synthetic fiber according to any one of claims 1 to 6 as a weft.