JPH073189Y2 - Bowstring raw yarn - Google Patents

Description

[Detailed Description of the Invention] <Industrial field of application> The present invention relates to a bowstring raw thread for making arch strings for archery and archery, and provides high-performance strings with excellent strength and creep performance. The purpose is to do.

<Problems to be solved by conventional techniques and devices> Bow strings are generally made of polyethylene tape in archery.
Rephthalate fiber (Dayupon Co., Ltd. Dacron ) Is used
ing. If these strings are attached to the bow and left unattended,
A creep phenomenon occurs in which the strings gradually grow. For this reason
Always requires fine tuning, which in turn aggravates hit rates
It will be.

On the other hand, strings using aramid fiber (Kevlar made by DuPont) appeared at the 28th Archery World Championships in 1975, and their performance was so excellent that they quickly spread to the whole world. The reason is that the strength of the yarn is high, the modulus is high, and the creep is small. Although the aramid fiber has excellent performance as described above, it has a large change in physical properties during moisture absorption and water absorption, and has a drawback that its properties vary depending on the weather. This is because the moisture absorption of aramid fiber is 4.3% at 20 ℃ × 65% humidity, and 20 ℃ × 100.
Caused by 87% in% humidity. Attempts have been made to apply a special wax to the strings in order to prevent changes in physical properties due to moisture absorption, but the effect is insufficient.

<Means for Solving Problems> The present inventor has studied a string having high strength, high modulus, little creep, and no change in physical properties when absorbing moisture. As a result, a wholly aromatic polyester fiber is used as a material for the string. Therefore, it has been found that all of the above requirements, particularly the problem at the time of moisture absorption, can be solved.

The wholly aromatic polyesters referred to herein are one or more aromatic hydroxy acids, optionally aromatic diols and / or
Or a melt-processable aromatic polyester by condensation with an aromatic diacid, which is called wholly aromatic in the sense that at least one aromatic ring of each component present contributes to the polymer backbone. A wholly aromatic polyester,
It means a so-called thermotropic liquid crystalline wholly aromatic polyester capable of forming an anisotropic melt phase.

Of these wholly aromatic polyesters, hydroxybenzoic acid, especially p-hydroxybenzoic acid and 6-hydroxy-
Polyester with 2-naphthoic acid, or even p,
In addition to polyesters copolymerized with p'-bisphenol as the third component, polyesters composed of p-hydroxybenzoic acid, p, p'-biphenyl, terephthalic acid and / or isophthalic acid are useful, but are not limited thereto. However, it does not hinder the introduction of other components into the polymer as long as the object of the present invention is not impaired.

Generally, these wholly aromatic polyester fibers have excellent physical properties as described below and achieve the object of the present invention.

Strength 15g / d or more Young's modulus 300g / d or more Cutting elongation 6% or less 200 ℃ Dry heat shrinkage 0.5% or less 120 ℃ Hot water wet heat shrinkage 0.3% or less 20 ℃ × 65% Water absorption under RH 0.6% Less than 60% in hot water at 120 ° C for 100 hours 60% or more Retention after treatment In particular, those containing as a main component a copolymer of p-hydroxybenzoic acid and 6,2-hydroxynaphthoic acid 20g / d or more Young's modulus 500g / d or more Cutting elongation 4% or less Water absorption rate under 20 ℃ × 65% RH 0.1% or less Water absorption rate under 20 ℃ × 95% RH 0.2% or less.

To make the raw yarn for strings, it is treated with a rosin-based resin in order to improve the focusing when combined. The raw yarn for strings consists of so-called multifilament, 1500d / 1 twisted yarn and 1000d / 1 3
There are main twists, braids, or 1500d / 1 double twists, but the present invention does not limit them. Archery players use these yarns to make strings themselves, but the number of strings used also differs depending on the bow size. Generally, 8 to 12 pieces are used.

FIG. 1 shows a schematic diagram of the Archery bow. In the figure, 1 is a bow string. 2 to 4 show a structural diagram of a raw yarn for a bowstring. Three types are preferred. Second
The yarn for the bowstring shown in the figure is made by twisting two filaments of 1500 denier into 3000 denier and twisted. The original yarn in Fig. 4 is
Three 1000 denier twisted yarns are combined to form a braid. Next, the present invention will be specifically described with reference to Examples and Comparative Examples.

Example 1 A solution liquid crystal polymer composed of a copolymer of p-hydroxybenzoic acid and 6,2-hydroxynaphthoic acid was used, and after melt-spin prevention, heat treatment was performed in an inert gas to give a total aromatic content of 1500 d / 300f. A polyester filament yarn was prepared. The performance of the yarn was as follows.

Strength: 26g / d Young's modulus: 600g / d Cutting elongation: 3.8% Moisture absorption rate 20 ℃ × 60%; 0.1% 20 ℃ × 100%; 0.3% Twist these 1500d yarns (50 times / (per m), treated with a rosin-based resin solution to give tackiness, and used as a raw thread for strings. The performance of the raw yarn for bow is shown in Table 1 in comparison with the comparative example. As a comparative example, aramid fiber and polyethylene terephthalate fiber were treated in the same manner as in the example.

[Brief description of drawings]

FIG. 1 is a side view of an archery bow, where 1 is a string. 2 to 4 are front views of the bowstring raw yarn.

Claims (1)

[Scope of utility model registration request] 1. A bowstring raw yarn comprising a wholly aromatic polyester fiber.