JPH0872668A - Safety belt - Google Patents

Abstract

PURPOSE: To provide a safety belt excellent in both the initial restraining force and the impact absorption. CONSTITUTION: A safety belt consists of the texture matrix whose warp is the highly elastic fiber (A) of tensile elastic modulus of 500-1200g/d and the fiber (B) of tensile elastic modulus of 30-200g/d, and satisfies the formula 0.05.Y.Tb<=X.Ta<=0.5.Y.Tb (where, Ta and Th are the strength of the fibers A and B respectively, and the total denier of the fiber A and the fiber B consisting the warp are X and Y respectively.).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety belt, and more particularly to a safety belt having a large initial restraining force and having an effect of absorbing shock and absorbing shock. It can be effectively used for safety belts used in aerial work, automobiles, etc.

[0002]

2. Description of the Related Art Conventionally, a safety belt made of polyester fiber, nylon or the like has been widely used because of its advantages such as high strength to some extent and excellent impact absorption.

[0003]

The safety belt described above is
Although it has high elongation and excellent impact absorption, it has a large elongation when a load is applied, and there is a big problem when it is used for a seat belt or the like. In other words, when a large load is applied, it is stretched and cannot fully function as a seat belt. Therefore, the head and body shake greatly, and the windshield and the handle are struck, and safety cannot be sufficiently maintained.
On the other hand, conventionally, high strength fibers such as polyarylate fiber and aramid fiber have been known. These fibers have the advantage that they have a high elastic modulus and extremely small elongation when a load is applied (the initial binding force is large). However, even if a safety belt is manufactured using such fibers, it is difficult to obtain satisfactory performance. That is, although the high elastic modulus fiber certainly has a large initial restraining force, it has a small impact absorption property, so that the impact applied to the body is too strong and the ribs are broken or the chest is damaged.

These are the load-stretch curves (str
It can be confirmed by ess-strain curve) (see FIG. 1: hereinafter sometimes abbreviated as SS curve). In the SS curve, the magnitude of elongation with respect to the load (elongation) shows the initial restraining force, and the area under the curve (corresponding to the work amount) becomes the parameter showing the shock absorption (energy absorption). . From this figure, it can be seen that polyester fibers and the like have large impact absorption (area under the curve) but low initial binding force, and that fibers with high elastic modulus are excellent in initial binding force but inferior in impact absorption. be able to. As described above, the shock absorbing property and the initial binding force are contradictory required performances, and an object of the present invention is to obtain a safety belt satisfying the required performances.

[0005]

The present invention has a tensile modulus of elasticity of 5
The present invention provides an excellent safety belt that is composed of a woven fabric having warp yarns having a high elastic modulus fiber (A) of 0 to 1200 g / d and a fiber (B) having a tensile elastic modulus of 30 to 200 g and satisfying the following formula. is there. 0.05 · Y · Tb ≦ X · Ta ≦ 0.5 · Y · Tb (However, the strength g / d of the fiber A and the fiber B is Ta, Tb,
In addition, the total number of denier d of the fibers A and the fibers B constituting the warp yarn d
Be X and Y. )

In the present invention, X · Ta represents the strength g of the aggregate of A fibers (hereinafter simply referred to as A fiber bundle) that constitutes the warp yarn, and Y · Tb represents the B fiber that constitutes the warp yarn. Of the aggregate (hereinafter abbreviated as B fiber bundle) g
Is shown. When the strength and total denier of the A fiber (that is, the strength of the A fiber bundle) are increased, the A fiber is less likely to be cut. As a result, when used as a seat belt or the like, the initial restraining force at the time of an accident is sufficient, but the human body is tightened to cause problems such as chest injury. In a safety belt represented by a seat belt, the present inventors fully exhibit the performance (initial restraint force) of the A fiber when an accident occurs, and the A fiber is cut before the human body is damaged. It has been found that it is necessary to exert the performance (shock absorption) of the B fiber, and for that, the strength of the A fiber and the B fiber, and the total denier number must be within a specific range. .

To obtain the effect of the present invention, 0.05.
It is necessary to satisfy Y · Tb ≦ X · Ta ≦ 0.5 · y · Tb. When X · Ta is large, problems such as physical damage occur as described above. On the contrary, when X · Ta is small, the A fibers are easily cut, and the body is fixed at all times (initial binding force). Etc. will be insufficient. Preferably, 0.
1 · Y · Tb ≦ X · Ta ≦ 0.45 · y · Tb.
In addition, in designing a safety belt, generally, the maximum strength Tu required in a normal use range is 1/2 or less of the necessary strength Tm in comparison with the necessary strength (Tm) for maintaining safety. k (generally 3 to 6 is adopted)
K · Tm multiplied by is strong in design.

In the present invention, Y · Tb ≧ k · Tm,
It is preferable that Tu ≦ X · Ta ≦ Tm. In this case, under the conditions that are usually used, the A fiber is not cut and exhibits an excellent initial restraint force, and a large load (X · T
a) or more), the A fiber acts to increase the initial restraining force, then absorbs the impact energy while cutting sequentially, and finally secures with the B fiber (≧ k · Tm). It is possible (see FIG. 2, Example 1). Numerical values such as Tm and Tu are appropriately set depending on the purpose and application. For example,
In the case of a seat belt, Tu = 300 kg, Tm = 640
Values around kg and k = 2.5 can be adopted. The A fibers having a tensile elastic modulus of 500 to 1200 g / d according to the present invention are not particularly limited as long as they are woven long fibers, but polyarylate fibers and aramid fibers are preferred examples. Among them, polyarylate fibers obtained from melt anisotropic polyester are particularly preferable.

The melt anisotropy means that the melt phase exhibits optical anisotropy. This characteristic makes the sample hot
It can be easily identified by placing it on the test piece, heating it up in a nitrogen atmosphere, and observing the transmitted light of the sample. The melt-anisotropic aromatic polyester is, for example, a polymer obtained from aromatic diol, aromatic dicarboxylic acid, aromatic hydroxycarboxylic acid or the like, and preferably comprises a combination of repeating structural units shown in Chemical formula 1. Examples thereof include polymers, but of course the present invention is not limited to this example.

[0010]

Embedded image

Melting point (MP) of melt anisotropic polyester
Is preferably 260 to 380 ° C, particularly preferably 270 to 350 ° C. MP is a differential scanning calorimeter (DS manufactured by Metra Co., Ltd.
The peak temperature of the main endotherm observed in C). As a particularly preferable melt anisotropic polyester, the portion consisting of the structural units (A) and (B) shown in Chemical formula 2 is 60% by mole or more, and particularly the component (A) with respect to the total amount of (A) and (B). Is in the range of 5 to 45 mol%.

[0012]

Embedded image

The fibers are required to be colored depending on the use and purpose, but in general, high modulus fibers such as polyarylate fibers and aramid fibers have a problem of poor dyeability. Polyarylate fibers, particularly the fibers of the above chemical formula 4, are preferable because they can be easily used as the primary fibers.

The B fibers having an elastic modulus of 30 to 200 g / d according to the present invention are not particularly limited as long as they are woven long fibers, but nylon and polyethylene terephthalate.
Suitable examples include polyesters and polyolefins represented by G. Single fiber denier 5-20d,
The yarn denier is preferably 1000 to 2000 d, and the strength is preferably 7 to 10 g / d. The polymers constituting the A fiber and the B fiber are polyethylene terephthalate, modified polyethylene terephthalate, polyolefin, polycarbonate, polyarylate, polyamide, as long as the effects of the present invention are not impaired. It may contain a thermoplastic polymer such as polyphenylene sulfide, polyether ether ketone, and fluorine resin, and inorganic materials such as titanium oxide, kaolin, silica, barium oxide, carbon black, colorants such as dyes and pigments, etc. It may also contain additives such as an antioxidant, an ultraviolet absorber and a light stabilizer.

The A fiber and the B fiber may be warped in any form, but it is more preferable that the A fiber and the B fiber are warped so as to be uniform. Fibers other than the A fiber and the B fiber may be used as long as the effects of the present invention are not impaired. The safety belt of the present invention has a woven structure in which the A fibers and the B fibers are warp yarns, but the fibers constituting the weft yarns are not particularly limited as long as they can maintain the belt form and can be woven. The warp yarn used in the present invention may be the same as the warp yarn, or a general-purpose fiber such as polyester, nylon or polyolefin having a weight of about 1 to 2000 d may be used. The woven fabric used in the present invention can be produced by an ordinary belt loom, a needle loom, or the like,
A safety belt can be manufactured on such a fabric structure by a general method such as a heat setting step, a dyeing step, a resin processing step.

[0016]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the examples. [Strength and elastic modulus] According to JIS L 1013, test length 20 cm, initial load 0.1 g / d, tensile strength 10 cm /
The breaking strength and elongation and the elastic modulus (initial tensile resistance) were determined under the condition of min, and the average value of 5 points or more was adopted. [Manufacture of Fiber A] 0.03% of carbon black was blended with an aromatic polyester polymer having a molar ratio m / n of 73/27 composed of the structural units shown in (D) of Chemical formula 2. 1000d / 200f of polymer at spinning temperature of 320 ° C
The black black yarn was spun. Then spun raw yarn in nitrogen 2
It was treated at 70 ° C. for 10 hours. The performance of the obtained heat treated yarn is as follows: strength Ta23 g / d, elongation 3.4%, elastic modulus 620.
It was g / d.

[Production of Fiber B] Polyethylene terephthalate ([η] = 0.74 dl / g: Upperode type in a constant temperature bath at 30 ° C. using an equal volume mixed solvent of phenol and tetrachloroethane). Intrinsic viscosity measured by viscometer) 300
Spun at ℃ and then stretched 4.6 times to 1000d / 25
0f of fiber was obtained. The performance of the obtained fiber is strength Tb.
The elastic modulus was 8.5 g / d, the elongation was 25.7%, and the elastic modulus was 72 g / d.

Example 1, Comparative Examples 1 to 4 Warp yarn warp was performed by changing the number of the A fibers and B fibers used, and further polyester 400d / 80 similar to B fibers.
A belt was prepared with a needle loom using f as a weft yarn.
When this was dyed gray with a disperse dye, a belt was formed in which the A-fiber was not substantially dyed, but the yarn of the original dye had a thin striped pattern. The structure of this safety belt is shown in Table 1 (a,
b is the total number of A fibers and B fibers used as warp yarns). The load elongation curve of the obtained safety belt is shown in FIG. At this time, the normal maximum strength Tu is 300 kg and the required strength Tm is 6
40kg, safety factor k is 2.5, design strength k · Tm is 1
It was set to 600 kg.

[0019]

[Table 1]

It can be seen that the conventional safety belt using only B fibers (Comparative Example 1) has a relatively large area under the SS curve and is excellent in shock absorption, but it has an initial binding force during normal use. Low and problematic. When a small amount of A fiber is used (Comparative Example 2), the initial binding force is improved as compared with Comparative Example 1, but since X · Ta is low, the A fiber is easily cut during regular use, It is not possible to utilize the initial binding force of the A fiber in the event of an accident. On the other hand, when a large amount of A fiber is used (Comparative Example 3), although the initial restraining force is sufficiently excellent, X.Ta is unnecessarily high and thus is difficult to be cut,
There is a risk of tightening the human body and causing chest disorders. On the other hand, the safety belt of the present invention (Example 1) has a small elongation with respect to an initial load (a large initial restraining force), exhibits its effect sufficiently in the event of an accident, etc., and is a fiber before the human body is damaged. It is possible to secure the safety of the human body while absorbing the shock as the B line is extended and the B line is extended.

[0021]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a safety belt which is excellent in initial restraining force and shock absorbing property, and particularly suitable for a seat belt used for automobiles and airplanes.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing load / elongation curves of high elastic modulus fibers (polyarylate fibers) and general-purpose fibers (polyester fibers).

FIG. 2 is a load / elongation curve of the safety belts of Example 1 and Comparative Examples 1 to 3.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 30, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012]

Embedded image

Claims (1)

[Claims] 1. A safety comprising a woven fabric structure comprising a warp yarn having a high elastic modulus fiber (A) having a tensile elastic modulus of 500 to 1200 g / d and a fiber (B) having a tensile elastic modulus of 30 to 200 g and satisfying the following formula. belt. 0.05 · Y · Tb ≦ X · Ta ≦ 0.5 · Y · Tb (However, the strength g / d of the fiber A and the fiber B is Ta, Tb,
In addition, the total number of denier d of the fibers A and the fibers B constituting the warp yarn d
Be X and Y. )