JP2000303254A - High strength hollow fiber for industrial material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high strength hollow industrial fiber made of a thermoplastic polymer, having plural hollow parts via bridging parts, having a specific hollow ratio, strength and elongation and suitable for a ship mooring rope since it has a sufficient strength and durability, and sufficient buoyancy to float on water. SOLUTION: This fiber is made of a thermoplastic polymer mainly composed of nylon 6 preferably having a relative viscosity of 2.8 or more. Each of single yarns has four hollow parts 1 in the shape of a cross section of a fiber in such a manner that two or more hollow parts 1 are formed via a bridging part 2, and a cross-shaped bridging part 2 is formed preferably near the center, and the single yarn has a hollow ratio of 10-35% a strength of 6.5 cN/dtex or more and an elongation of 15-25%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength hollow fiber for industrial materials, which has sufficient strength and durability and has sufficient buoyancy to float on water, and is particularly suitable for a rope for mooring a ship. .

[0002]

2. Description of the Related Art Ropes for ships used for mooring large ships, ferry boats and the like or ropes used at various construction sites are required to have high strength and long service life.
In addition, although the lengths of these ropes vary, generally, a tip portion thereof is subjected to a process called ice-price processing (satsuma processing) so as to be convenient for connection with an object.

[0003] Ice price processing is based on JIS L021.
As defined in 9, after the end of the rope is looped, the tip is loosened and the strand is inserted between the ropes. However, since the rope is usually very hard finished, the work for this processing is difficult.

[0004] In addition to the strength and durability of the mooring and towing ropes, it is important in terms of workability that they float on the water surface for a long time without sinking in water. For example, polyamide fibers centering on nylon 6 are used for various industrial materials because of their high strength and long service life. The rope made of polyamide fiber is submerged in water, and the rope itself absorbs moisture and becomes heavier, which increases the work labor, especially the load at the time of winding.

[0005] In particular, when used as a ship tow rope in a tugboat or the like, there is a problem in that when the rope is removed, the rope sinks in water and becomes tangled with the screw of the ship, which is dangerous.

Further, Japanese Patent Publication No. 61-13012 discloses a nylon crimped yarn having four hollow portions in a cross section of a single yarn. However, this nylon fiber is suitable for carpets and is excellent in antifouling property and bulkiness, but is low in both strength and hollow ratio and is not suitable for industrial materials. In particular, even if this fiber was used for a rope, it could hardly float on water and had low strength, so that it was impossible to anchor or tow a ship.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, has a sufficient strength and elongation, can float on water when formed into a rope, and has excellent ice-price workability. Accordingly, it is an object of the present invention to provide a high-strength hollow fiber for industrial materials that is particularly suitable as a mooring ship or a tow rope.

[0008]

Means for Solving the Problems The present inventors have studied to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention comprises a thermoplastic polymer, and each single yarn has two or more hollow portions via a crosslinked portion in a cross-sectional shape of the fiber, a hollow ratio of 10 to 35%, and a strength of 6.5 cN /
A high-strength hollow fiber for industrial materials, which has a dtex of at least dtex and an elongation of 15 to 25%.

The hollow ratio of the fiber in the present invention is defined as
Refers to the ratio of the area of the hollow portion in the cross-sectional shape of the single yarn,
A microphotographing device was attached to a Microphoto S optical microscope manufactured by Nikon Corporation, and the cross-sectional shape of the cross section of a single yarn was photographed. As shown in the schematic cross-sectional view of the four-hole hollow fiber of the present invention in FIG. The values of the (hollow portion) and the area B (non-hollow portion) were calculated and calculated by the following equation, which is the average value for five single yarns. Hollow ratio (%) = [(Area A) / (Area A + Area B)] ×
100

[0010]

Next, the present invention will be described in detail. Examples of the thermoplastic polymer constituting the hollow fiber of the present invention include nylon 6, nylon 11, nylon 12, nylon 46, nylon 66, nylon 610, and the like, and polyamide, polyethylene terephthalate, polybutylene terephthalate, and the like containing these as a main component. And the like. These can be used alone, or copolymerized or blended. And, as long as the effects of the present invention are not impaired,
The thermoplastic polymer may include a matting agent, a modifying agent, an antistatic agent, a pigment, and the like.

Among them, nylon 6 having a relative viscosity of 2.8 or more, which is inexpensive and has excellent strength and durability, is preferable.
Those having a relative viscosity of 3.0 or more, more preferably 3.5 or more, are preferred.

The relative viscosity in the present invention is measured at a concentration of 1 g / dl and a temperature of 25 ° C. using 96% sulfuric acid as a solvent. If the relative viscosity is less than 2.8, the strength is reduced, and the material tends to be unsuitable for industrial materials. The upper limit of the relative viscosity is not particularly limited, but is preferably set to 4.0 or less in order to prevent the spinning and spinnability from lowering.

[0013] The hollow fiber of the present invention has a strength of 6.5.
It is necessary that the strength is not less than cN / dtex and the elongation is 15 to 25%, and it is particularly preferable that the strength is not less than 7.5 cN / dtex and the elongation is 18 to 23%. This is a property required for being a material used for industrial material use.

[0014] If the strength is less than 6.5 cN / dtex, the rope obtained by tying this fiber will have insufficient strength to anchor and tow a ship. Also,
When the elongation is less than 15%, the orientation of the fiber is excessively advanced, so that the fiber becomes brittle and easily cut. On the other hand, the elongation is 2
If it exceeds 5%, the rope obtained by tying this fiber is further stretched when used, and the strength and durability are reduced.

Next, the hollow fiber of the present invention will be described with reference to the drawings. FIGS. 1, 3, and 4 are schematic cross-sectional views showing an embodiment of a single fiber cross-sectional shape of the hollow fiber of the present invention. FIG. 1 shows a four-hole cross-sectional shape in which four hollow portions 1 are arranged so as to form a cross-shaped bridging portion 2 in the vicinity of the center. FIG. 3 has two hollow portions 1. FIG. 4 has three hollow portions 1.

In the hollow fiber of the present invention, each single yarn has two or more hollow portions 1 via a bridge portion 2 in a cross-sectional shape. The presence of the bridging portion between the hollow portions allows the strength to be maintained and the hollow portion to be prevented from being crushed, thereby retaining the hollow portion even when the product is made into a rope or the like. However, the hollow ratio does not decrease.

It is preferable that the number and positions of the hollow portions are such that the strength can be maintained. In particular, as shown in FIG. 1, four hollow portions are formed so as to form a cross-shaped bridge near the center. It is preferable to have a four-hole cross-sectional shape. With such a four-hole cross-sectional shape, since the cross-linking portion has a cross shape, resistance to stress from multiple directions is increased, and a fiber having higher strength and a lower hollow ratio is obtained.

The hollow fiber of the present invention has a hollow ratio of 10 to 35%, which is the ratio of the area of the hollow portion to the cross-sectional area.
It is necessary to be. By setting the range of the hollow ratio, it is possible to maintain the strength of the fiber, and to make the specific gravity of the rope made of this fiber such that it floats on water. Can be generated, and workability at the time of ice price processing is improved.

Here, the specific gravity in consideration of the hollow ratio is an apparent specific gravity that can be calculated by the following equation. When nylon 6 was used, the specific gravity of the yarn was 1.14 and the hollow ratio was 10 to 3
When it is 5%, the apparent specific gravity is 0.74 to 1.03, and it is particularly preferable that the apparent specific gravity is 0.95 or less. Apparent specific gravity = [(100-hollow ratio) / 100] x specific gravity of raw yarn

When the hollow ratio is less than 10%, the apparent specific gravity becomes large, and the rope made of this fiber tends to sink in water. In addition, the elastic deformation of the fiber is less likely to occur, and the workability at the time of ice price processing is not improved. On the other hand, when the hollow ratio exceeds 35%, the strength of the fiber cannot be maintained, and the hollow portion is crushed or broken.

Further, in the hollow fiber of the present invention, when a polyamide is used as the thermoplastic polymer, a bisamide compound having a long-chain alkyl group is preferably added.

The compound includes, for example, metaxylylenebisstearylamide, metaxylylenebisoleylamide, ethylenebisstearylamide and the like, among which ethylenebisstearylamide (EB) is preferable.

The hollow ratio of the hollow fiber is closely related to the spinning temperature, and it is necessary to lower the spinning temperature in order to increase the hollow ratio. However, a decrease in the spinning temperature simultaneously causes melting spots and the like, and there is a concern that the strength of the fiber may decrease. For this reason, in the production of fibers that require strength, it is necessary to maintain the spinning temperature at a certain level.

By adding EB, the shape of the single fiber can be maintained without lowering the spinning temperature, so that a high hollow ratio can be obtained, and a fiber having high strength and a high hollow ratio can be easily obtained. Becomes

The amount of EB added is from 0.01 to the weight of the fiber.
It is preferably 1.0% by weight, especially 0.05 to
0.2% by weight is preferred. When the content is less than 0.01% by weight, the effect of maintaining the single yarn shape is not sufficiently exhibited,
On the other hand, when the content exceeds 1.0% by weight, there is a concern that the spinning operability such as the strength is reduced or the yarn breakage is deteriorated.

Further, when a polyamide is used as the thermoplastic polymer, it is preferable to add a silicon compound to the polymer.

The addition of the silicon compound has the effect of maintaining the shape of the fiber single yarn and increasing the hollow ratio, and also has the effect of reducing the specific gravity of the resin itself, so that the specific gravity of the entire fiber can be reduced. Fibers that can float more easily in water can be obtained. At the same time, it also has the effect of improving the abrasion resistance of the fiber, which makes it possible to improve the durability of the rope.

The silicon compound to be added has an effect of maintaining the shape of the single fiber of the fiber, and it is sufficient if the specific gravity of the resin can be reduced. Particularly preferred are organopolysiloxane (silicon resin) and layered silicate (nanosilicate). Composite nylon).

The amount of the silicon compound to be added is from 0.01 to the weight of the fiber.
1.0 wt% is preferred, among them 0.05 to 0.2 wt%
Is preferred. If it is less than 0.01% by weight, the effect of maintaining the single yarn shape is not sufficiently exhibited, while if it exceeds 1.0% by weight, there is a concern that the spinning operability such as a decrease in strength or yarn breakage may be deteriorated. .

As described above, the hollow fiber of the present invention is such that the rope made of the fiber floats on the water for about one month or more even if it is not subjected to waterproofing, water repellency, etc. Can be. However, depending on the environment in which water is gradually absorbed from the part that is in contact with water,
If the water is absorbed more than water repellent, or if water is absorbed between the woven fibers or the laces, the entire rope will sink in the water. Therefore, by performing a waterproofing process such as waterproofing and water repelling on the rope surface when the fiber or the rope of the present invention is used,
It is possible to provide a rope that is more water-resistant and floats on water for a long time.

Next, an example of the method for producing a hollow fiber of the present invention will be described. It can be manufactured using a melt spinning device equipped with a normal hollow fiber spinneret. Any of the two-step method in which stretching is performed after the film formation may be adopted. However, in order to manufacture with high productivity, it is preferable to use the one-step method.

Further, since the hollow fiber of the present invention is used for industrial materials, it is preferable that the single fiber fineness is about 4.0 to 50 dtex and the total fineness is about 600 to 3500 dtex.

[0033]

Next, the present invention will be described in detail with reference to examples. In addition, measurement and evaluation of various values in the examples were performed as follows. [Strength of elongation] Using an autograph S-100 manufactured by Shimadzu Corporation, apply an initial load (g) of fineness (d) × 1/20, sample length 25c
m, and the tensile speed was measured at 30 cm / min. [Hollow ratio] It was measured and calculated by the above method. [Apparent specific gravity] It was calculated by the above equation. [Water buoyancy] The obtained fiber was used to make an 8 x 8 string product using a string machine, and the string product was cut into 20 cm.
Both ends were tied and left in water. Observations were made 24 hours after standing, 1 week after standing, and 3 weeks after standing. ○ indicates a floating state, and × indicates a state of being completely submerged in water. [Ice price processability] Three obtained fibers were aligned to prepare a ply twisted cord having a twist number of 120 TPM in the S direction.
An alignment code was created with the number of twists of 0 TPM. Further, 22 cords are aligned and twisted with a twist number of 110 TPM to form a strand. Finally, it was hit with three strands to make a 16 mm rope. The workability at the time of ice-price processing of this rope was evaluated in two stages of ○ and ×.

Example 1 0.1% by weight of EB was added to nylon 6 pellets having a relative viscosity of 3.51 and fed to an extruder. Melt spinning was performed at a spinning temperature of 278 ° C. using a melt spinning apparatus equipped with a hollow fiber spinneret. did. After cooling the spun yarn and applying a non-aqueous oil agent, the total draw ratio between the hot rollers at a roller temperature of 130 to 190 ° C is 4.
It is hot drawn at a magnification of 70 times, wound up at a speed of 2500 m / min, and has a four-hole cross section hollow fiber (940 dt) as shown in FIG.
ex / 68f).

Example 2 The procedure of Example 1 was repeated except that the amount of EB added was changed to 0.05% by weight and the spinning temperature was changed to 280 ° C.

Example 3 Silicon resin 0.1 was added to nylon 6 pellets in addition to EB.
The procedure was performed in the same manner as in Example 1 except that wt% was added.

Example 4 The procedure of Example 1 was repeated except that the spinneret was changed.
As shown in FIG.

Example 5 The procedure of Example 1 was repeated except that the spinneret was changed.
As shown in FIG.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the spinneret was changed and each single yarn had a round cross section without a hollow portion, and a fiber having a round cross section (940 dtex / 68f) was used. ) Got.

Comparative Example 2 The procedure of Example 1 was repeated except that 0.1% by weight of magnesium stearate was added to nylon 6 pellets instead of EB.

Comparative Example 3 The procedure of Example 1 was repeated except that the amount of EB added was 0.2% by weight and the spinning temperature was 268 ° C.

Comparative Example 4 A hollow fiber was obtained in the same manner as in Example 1 except that the spinneret was changed and each single yarn had a round cross section having one hollow portion.

Table 1 shows the evaluation results of the strength and elongation, the hollow ratio, the apparent specific gravity, the water floating property, and the ice price processability of the fibers obtained in Examples 1 to 5 and Comparative Examples 1 to 4.

[0044]

[Table 1]

As is evident from Table 1, the hollow fibers of Examples 1 to 5 have a sufficient strength and elongation, and the ropes made of these fibers have excellent water floating properties and have not been subjected to a water-repellent treatment. Also one
He has been floating on the water for more than a month. And the workability at the time of ice price processing was also excellent. On the other hand, the fiber of Comparative Example 1 has a large specific gravity because there is no hollow portion,
The rope made of this fiber did not float on the water from the beginning, and was inferior in ice-price processability. The apparent specific gravity of the fiber of Comparative Example 2 was increased because the hollow ratio was too low,
The lacquer submerged in water within 24 hours when placed in water.
In addition, it was inferior in ice price workability. The fiber of Comparative Example 3 was inferior in strength and elongation because the hollow ratio was too large.
Operability was poor. Since the fiber of Comparative Example 4 had one hollow portion, there was no cross-linked portion, the strength was low, and the hollow portion was crushed when the rope was used. Therefore, the apparent specific gravity was less than 1.0. However, it was inferior in water buoyancy, and sank in water about two days after floating on the water.

[0046]

As described above, the high-strength hollow fiber of the present invention is a fiber having a sufficiently high elongation and a high hollow ratio in which the hollow portion is hardly crushed. Rope made of this fiber is not only excellent in strong elongation and durability, but also can float on water for a long time, so there is a danger that it will sink and become entangled with the screw when the rope is removed. It becomes extremely small, and the work safety is greatly improved, and at the same time, the work effort can be reduced. Furthermore, it is easy to cause elastic deformation at the time of ice-price processing, and the workability of ice-price processing is excellent.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing one embodiment of a single fiber cross-sectional shape of a hollow fiber of the present invention.

FIG. 2 is a schematic cross-sectional view showing a method for calculating a hollow ratio of a hollow fiber of the present invention.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the cross-sectional shape of a single fiber of the hollow fiber of the present invention.

FIG. 4 is a schematic cross-sectional view showing another embodiment of the cross-sectional shape of a single fiber of the hollow fiber of the present invention.

[Explanation of symbols]

 1 hollow part 2 bridge part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaki Okutonouchi, Uji-city, Kyoto, Japan 5 Unitika Co., Ltd., Uji Plant (72) Inventor Takeshi Nishiyama 5 Ujitonouchi, Uji-shi, Kyoto, Japan 5 Unitika Co., Ltd., Uji Plant (72) Inventor Hiroshi Imagawa 5 in Ujitonouchi, Uji-city, Kyoto, Japan Unitika Co., Ltd. Uji factory (72) Inventor Yoshitaka Matsuo 5 in Ujitonouchi, Uji-shi, Kyoto, Japan 5 Unitika, Uji factory F-term (reference) 4L035 AA09 BB32 BB91 DD03 EE08 FF01 HH10 4L045 AA05 BA03 BA14 BA24 BA49 BA50 BA60 CA25 DA14 DA42 DA53 DC02

Claims (3)

[Claims] 1. A single yarn is made of a thermoplastic polymer, and each single yarn has two or more hollow portions via a crosslinked portion in a cross-sectional shape of the fiber, a hollow ratio of 10 to 35%, and a strength of 6.5 cN / d.
A high-strength hollow fiber for industrial materials, which has an elongation of at least tex and 15 to 25%. 2. The high-strength hollow fiber for industrial materials according to claim 1, wherein the thermoplastic polymer is mainly composed of nylon 6 having a relative viscosity of 2.8 or more. 3. The high-strength hollow fiber for industrial materials according to claim 1, wherein each of the single yarns has four hollow portions so as to form a cross-shaped bridging portion near the center in the cross-sectional shape of each single yarn.