JP2003052283A - Fishing line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fishing line improving the hydrolytic resistance without deteriorating the excellent characteristics of a high strength, a high modulus of elasticity and a low elongation possessed by polybenzazole fibers and maintaining the excellent characteristics for a long period. SOLUTION: This fishing line is obtained from the polybenzazole fibers having <=20 nm average square roughness of fiber surfaces, <=1.3 deg. crystal orientation angle of the fiber surfaces and >=5,200 cycles to rupture in abrasion tests.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to high strength, high elastic modulus,
The present invention relates to a novel fishing line using polybenzazole fiber having a low elongation.

[0002]

2. Description of the Related Art Generally, fishing lines are divided into a Harris line and a line line, and the performance required for the former is thin and strong, moderate waist hardness, quick sinking, invisible underwater, and difficult to shrink. and so on. The latter includes long castability, suppleness and unrevolving reel, light yarn, good hitting property, durability and the like. Among the characteristics of Harris, the most important point is that it is thin and strong, especially the knot strength is strong, and when these characteristics are Harris, it is difficult for fish to detect it, and it can withstand the weight of a large fish, This will lead to performance such as the number of Harris cuts being extremely small. On the other hand, the characteristic of the road yarn is that it is thin and strong, which is particularly important. If this property is used as the yarn, the flow resistance will be reduced, and it will lead to the performance that it is hard to be washed by tidal currents. .

Conventionally, as a material for fishing line, a line made of nylon, polyester, vinylon, poly (vinylidene fluoride) or the like has been used. However, for example, the tensile strength of polyvinylidene fluoride yarn is at most 8 g / d, and even in the case of nylon yarn, the normal strength type is 10 g / d and the high strength type is at most 15 g / d. The reality is that fishing lines with high strength have not been obtained. From these facts, recently, attention has been paid to the fact that the strength of the high-strength fiber made of aromatic polyamide is 20 g / d, and its application to fishing line is also considered. On the other hand, polybenzazoles (PBZ) such as polyparaphenylenebenzbisthiazole (PBT) and polyparaphenylenebenzoxazole (PBO) are used as new high heat resistance, high elastic modulus and high strength organic fibers.
However, it has been reported to have superior performance to aromatic polyamides. Therefore, it is naturally conceivable to use these materials for the fishing line. However, the PBZ fibers produced by the conventionally known spinning methods may have voids at the time of producing the fibers or at the time of post-processing, and as a result, the water resistance tends to decrease, so that excellent tensile strength as a fishing line is obtained. It was difficult to maintain for a long time.

[0004]

[Problems to be Solved by the Invention]
INDUSTRIAL APPLICABILITY The present invention prevents moisture from entering the inside of the fiber structure and prevents hydrolysis by making the surface structure of the fiber dense without impairing the excellent properties of the PBZ fiber, that is, high strength, high elastic modulus and low elongation. The present invention is intended to provide a fishing line that has improved properties and maintains excellent characteristics for a long period of time.

[0005]

That is, the present invention has the following constitution. 1. A fishing line characterized by comprising polybenzazole fibers having a mean square roughness of 20 nm or less on the fiber surface, and containing a lubricating oil or fat or a resin component in an amount of 0.9 wt% or more between the fibers. 2. The fishing line according to 1, wherein the polybenzazole fiber has a crystal orientation angle of 1.3 degrees or less on the fiber surface. 3. 2. The fishing line according to 1, wherein the polybenzazole fiber has an equilibrium water content of 0.6% or less. 4. The cycle until breakage in the abrasion test of the polybenzazole fiber is 5200 times or more. 1
The listed fishing line. 5. The fishing line according to 1, wherein the void diameter of the polybenzazole fiber is 25.5Å or more.

The present invention will be described in detail below from the method for producing fibers to the method for producing fishing lines. Rigid polymers such as so-called ladder polymers have been considered as a means of achieving the ultimate physical properties of fibers, but such rigid polymers are not flexible and are required to have flexibility and workability as organic fibers. It is an important condition to be a linear polymer.

SG Wierschke et al., Material Research Soc
iety Symposium Proceedings Vol.134, p.313 (1989)
As shown in Fig. 3, the linear polymer having the highest theoretical elastic modulus is cis-type polyparaphenylene benzobisoxazole. This result was also confirmed by Tashiro et al. (Macromolecules vol. 24, p. 3706 (1991)), and among polybenzazoles, cis-type polyparaphenylenebenzobisoxazole has a crystal elastic modulus of 475 GPa (P . Galen et al. Material Research Society Symposium P
roceedings Vol. 134, p.329 (1989)), considered to have the ultimate primary structure. Therefore, in order to obtain the ultimate elastic modulus, the theoretical conclusion is to use polyparaphenylene benzobisoxazole as the polymer material.

Fiberization of the polymer is described in US Pat. No. 5,2961,
No. 85, US Pat. No. 5,385,702, and the heat treatment method is the method proposed in US Pat. No. 5,296,185. The equilibrium moisture content of the yarn obtained by such a method is 0.6%. That is all. Therefore, as a result of keenly aware of the need for research on improvements of these methods, as a result of intensive research, the desired physical properties can be easily achieved industrially by the following methods even if the void diameter in the fiber is 25.5 Å or more. I found a thing.

A dope composed of polyparaphenylene benzobisoxazole (PBO) and polyphosphoric acid is spun from a spinneret. Thereafter, it is manufactured through coagulation, neutralization, washing with water, drying, and heat treatment under tension. As a means for suppressing the equilibrium moisture content to a low level, there is a method of densifying and highly orienting the crystal structure of the surface portion of the polymer constituting the fiber. In the present invention, for this purpose, a polybenzazole fiber was successfully industrially obtained in which the crystal structure of the surface of the polybenzazole fiber was finely changed and the water absorption was suppressed to an extremely low level.

The surface crystal structure of the fiber is characterized in that the mean square roughness of the fiber surface is 20 nm or less, and more preferably, the crystal orientation angle of the fiber surface is 1.3 degrees or less. The fiber is characterized by having an equilibrium moisture content of 0.6% or less, or a polybenzazole fiber characterized by having a cycle to break of 5200 or more in an abrasion test. Therefore, the present invention provides a polyparaphenylene benzobisoxazole fiber having an equilibrium moisture content as close to zero as possible by overcoming the technical difficulties so far and realizing a unique crystal orientation by such a technical background. It enables industrial production.

In order to bring out the above structural characteristics, the points of the present invention can be realized by the following method. That is, a spun yarn obtained by extruding a polymer dope composed of polyparaphenylene benzobisoxazole into a non-coagulating gas from a spinneret was introduced into a coagulating bath to extract phosphoric acid contained in the dope yarn. After that, neutralization, washing with water, drying,
It was found that polybenzazole having a densified fiber surface was obtained by heat-treating the fiber at a constant tension of 500 ° C. or higher.

The polybenzazole fiber in the present invention means a PBO homopolymer and substantially 85% or more P.
It refers to a random, sequential or block copolymer containing a BO component and polybenzazole (PBZ). Here, the polybenzazole (PBZ) polymer is, for example, “Liquid Crystalline Polymer Com” by Wolf et al.
positions, Process and Products '' U.S. Pat.No. 4703103
Issue (October 27, 1987), "Liquid Crystalline
Polymer Compositions, Process and Products "US Pat. No. 4533692 (August 6, 1985)," Liquid Cr
ystalline Poly (2,6-Benzothiazole) Compositions, Pr
ocess and Products ”US Pat. No. 4,533,724 (1985)
August 6, 2012), "Liquid Crystalline Polymer Composi
tions, Process and Products ”US Pat. No. 4533693 (August 6, 1985), Evers“ Thermooxidative-l
y Stable Articulated p-Benzobisoxazole and p-Benzo
bisoxazole Polymers "US Patent No. 4539567 (1982)
November 16, 2016), "Method for making Hete" by Tsai et al.
rocyclic Block Copolymer "US Pat. No. 4,578,432 (1
March 25, 986), and the like.

The structural unit contained in the PBZ polymer is preferably selected from lyotropic liquid crystal polymers. The monomer units consist of the monomer units described in structural formulas (a) to (h), and more preferably essentially consist of monomer units selected from structural formulas (a) to (d).

[0014]

[Chemical 1]

[0015]

[Chemical 2]

Suitable solvents for forming the dope of the polymer consisting essentially of PBO include cresol and non-oxidizing acids capable of dissolving the polymer. Examples of suitable acid solvents are polyphosphoric acid, methanesulphonic acid and concentrated sulfuric acid or mixtures thereof. Further suitable solvents are polyphosphoric acid and methanesulfonic acid. The most suitable solvent is polyphosphoric acid.

The polymer concentration in the solvent is preferably at least about 7% by weight, more preferably at least 10%.
% By weight, most preferably 14% by weight. The maximum concentration is
Limited by practical handling properties such as polymer solubility and dope viscosity. Due to these limiting factors, the polymer concentration does not exceed 20% by weight.

Suitable polymers, copolymers or dopes are synthesized by known methods. For example, Wolfe et al., U.S. Pat. No. 4533693 (August 6, 1985), Sybert et al., U.S. Pat. No. 4,772,678 (September 20, 1988), Har.
synthesized by the method described in US Pat. No. 4,847,350 of ris (July 11, 1989). Polymers consisting essentially of PBO are described by Gregory et al., US Pat. No. 5,089,591 (1992).
(February 18, 2012), it is possible to achieve a high molecular weight at a high reaction rate in a dehydrating acid solvent under relatively high temperature and high shear conditions.

The dope thus polymerized is supplied to the spinning section and discharged from the spinneret at a temperature of usually 100 ° C. or higher. A plurality of die holes are usually arranged in a circumferential shape or a lattice shape, but other arrangements may be used. The number of spinneret pores is not particularly limited, but the array of spinneret pores on the spinneret surface must be maintained at a pore density that does not cause fusion between the discharge yarns.

The spun yarn requires a sufficient draw zone length, as described in US Pat. No. 5,296,185, in order to obtain a sufficient draw ratio (SDR), and at a relatively high temperature (dope It is desirable to uniformly cool with a rectified cooling air having a solidification temperature or higher and a spinning temperature or lower). The length (L) of the draw zone needs to be the length at which solidification is completed in the non-solidifying gas, and is roughly determined by the single hole discharge amount (Q). In order to obtain good fiber properties, the draw-out stress in the draw zone needs to be 2 g / d or more in terms of polymer (assuming stress is applied only to the polymer).

The yarn drawn in the draw zone is then introduced into the extraction (coagulation) bath. Since the spinning tension is high, it is not necessary to consider disturbance of the extraction bath and any type of extraction bath may be used. For example, a funnel type, an aquarium type, an aspirator type or a waterfall type can be used. The extract is preferably phosphoric acid aqueous solution or water. Finally, in the extraction bath, the phosphoric acid contained in the yarn is extracted by 99.0% or more, preferably 99.5% or more.
The liquid used as the extraction medium in the present invention is not particularly limited, but preferably water, methanol, ethanol, acetone, ethylene glycol or the like which is substantially incompatible with polybenzazole. Also extraction (coagulation)
It is also possible to separate the bath in multiple stages, dilute the concentration of the phosphoric acid aqueous solution sequentially, and finally wash with water. Further, it is desirable to neutralize the fiber bundle with an aqueous solution of sodium hydroxide and wash it with water.

A method of finely changing the fiber surface structure, which is particularly important in the present invention, will be described. In order to prevent moisture absorption, realization of high crystal orientation on the fiber surface is an important factor.
For this reason, it is important to slow the coagulation rate of the fiber dope in the extraction step to change the structure in the inner and outer layers of the fiber. As a method of slowing the coagulation rate, it is effective to increase the concentration of the phosphoric acid aqueous solution in the coagulation liquid, lower the bath temperature, or select a non-aqueous coagulant. The optimum phosphoric acid aqueous solution concentration is 50% or more and less than 80%, preferably 55% or more and less than 70%, and most preferably 60% or more and less than 65%. The higher the concentration, the greater the effect, but if the concentration is higher than necessary, the fiber strength will decrease, which is not preferable. The coagulation bath temperature may be any number as long as it is approximately 5 ° C. or lower, but even if the temperature is lowered too much, dew is generated around the bath, which is not preferable in operating the manufacturing machine. The temperature range is preferably 4 ° C to -30 ° C, more preferably 0 ° C to -15 ° C. When a non-aqueous coagulant is selected, an organic solvent having an affinity for water, such as alcohols such as ethanol and methanol, ketones such as acetone, glycols such as ethylene glycol, is preferable. Of course, a plurality of the above non-aqueous coagulants and water may be mixed and used. After this, the fibers are dried and further heat treated. The drying temperature is a temperature that does not cause a decrease in fiber strength, and is specifically 150 ° C or higher and 400 ° C.
The temperature is preferably 200 ° C or higher and 300 ° C or lower, more preferably 220 ° C or higher and 270 ° C or lower. The heat treatment temperature is 400 ° C. or higher and 700 ° C. or lower, preferably 50
0 ° C to 680 ° C, more preferably 550 ° C to 6
It shall be 30 ° C or lower.

The fiber according to the present invention has a mean square roughness of the fiber surface of 20 nm or less, preferably 16 nm or less, more preferably 10 nm or less, and a crystal orientation angle of the fiber surface of 1.3 ° or less, preferably 1.1 ° or less, further Preferably 0.9 degrees or less, the equilibrium moisture content is 0.6% or less, preferably 0.55% or less, more preferably
0.5% or less, 5200 cycles to break in wear test
15 times or more, preferably 5600 times or more, more preferably 6000 times or more, void diameter is 25.5 Å or more, preferably 30 Å or more 15
It is less than 0 Å, more preferably 35 Å or more and less than 90 Å. The indexing of the diffraction points used in this patent is Frat.
ini et al. (Material Research Society Symposium Proceedi
ngs Vol. 134, p. 431 (1989)).

The mean square roughness Rms of the fiber surface is evaluated using an atomic force microscope (AFM). AFM is Seik
o Instruments (SII) SPI3800N
-Use SPA300. The probe has a spring constant of 2 N / m and a length of 450 μm.
A Si rectangular type cantilever SII (Si-DF3) having a width of 60 μm and a thickness of 4 μm was used. The scanner is a 100 μm scanner and the observation mode is DFM mode. Scan speed 0.5 Hz
The scanning direction is parallel to the fiber axis, and the measurement is performed under the conditions of 20 degrees Celsius and 65% relative humidity in the atmosphere. The fibers used for measurement are
It was used after being washed with a mixed solution of ethanol and n-hexane and dried. The observation field of view is a square area of 5 μm square on each side, and after observation, 3D tilt correction of the attached software is applied to perform planarization processing. In order to take into account the distortion caused when the image is flattened due to the presence of the fiber curvature, the mean square roughness Rms of only the central square area of 3 μm square is calculated after correction using the attached software. A measurement example is shown in FIG. Randomly observe at 10 or more points,
Was calculated and the average value was calculated. Note that Rms can be expressed using Equation 1.

Rms = [(1 / N) Σ (Z i −Z 0) ² ] ^0.5 Equation 1 Here, Z i is the height at each measurement point, Z 0 is the average height over the entire measurement point, and N is Indicates the number of measurement points.

The crystal orientation angle of the fiber surface is analyzed and evaluated by observing a thin piece peeled from the fiber surface with a high resolution using an electron microscope (eg Phillips TEM-430, JEOL JEM-2010). First, a collodion solution diluted with isoamyl acetate is thinly spread and spread on a glass plate, and several fiber single yarns are arranged. Wait for the collodion solvent to evaporate and solidify before peeling the fiber off the glass plate. At this time, it can be confirmed by a stereomicroscope that the flakes peeled off from the fibers adhere to the traces (on the film of collodion) peeled off at this time. This part is cut out together with the collodion film using a razor about 3 mm square, and the surface with the polybenzazole fiber surface flakes on the micro grid made by Nisshin EM Co. for electron microscope observation or the holey carbon film made by Agar Scientific. Place them face down.

Transfer to a Petri dish with a lid and leave it in the presence of isoamyl acetate vapor for several hours to sufficiently fix the fiber flakes to the microgrid. After that, isoamyl acetate is added until the microgrid is soaked, and the mixture is left for one day and night, and the collodion film is poured off and then dried. For high-resolution observation, an electron microscope was used after correcting astigmatism at 200,000 times or more. In order to minimize the damage of the sample fiber flakes from the electron beam, the exposure time required for one-view shooting is within 5 seconds, and the total irradiation time including the correction of astigmatism is the fiber when the electron beam is received. Within 35% of the lifetime (the duration during which an electron beam diffraction pattern with sufficient resolution can be observed). High resolution electron microscope (lattice) image recording can be accomplished by developing Kodak SO-163 negative film with Kodak D-19 developer undiluted or using an imaging plate system (eg JEOL Pi
xsys TEM). The photographed lattice image is printed on photographic paper. It is observed that the (200) lattice runs almost in the equilibrium direction with the fiber axis. The angle φ formed by the (200) lattice axes of two adjacent crystals is defined as the crystal orientation angle.
A set of 100 or more crystals is observed and averaged to evaluate the crystal orientation angle.

The crystal orientation ratio between the center of the fiber and the surface is obtained by measuring a selected area electron diffraction image of an ultrathin section made by slicing the fiber. A product embedded with Spurr epoxy resin in which a single fiber and a curing agent are mixed is left overnight in an oven at 70 ° C. to be solidified and fixed. Next, this resin block is attached to an ultramicrotome manufactured by Reichert, and polished using a glass knife until the embedded fibers appear near the block surface. Next, an ultrathin section is prepared using a diamond knife manufactured by Diatome Co., and then collected on a 300-mesh copper grid and subjected to thin carbon vapor deposition. An ultrathin section is placed in an electron microscope, a section having both the center and the surface of the fiber is sought, and a selected area electron diffraction image is taken of both the surface and the center. The image is recorded by electron microscopy film (eg Agfa Scientia EM 23D56, or Kodak SO-1).
63 negative film) or imaging plate system. The method of RJ Young et al. (J. Mat. Sci., 2
According to 4, p5431 (1990), (010) and (-210)
After calculating the half width 2θ of the peak profile from the spread of the diffraction intensity profile in the meridian direction of the diffraction point, Equation 2
The half-value width 2θ of the fiber center is calculated using
Then, the crystal orientation ratio between the fiber surface and the center is obtained. Incidentally, when digitizing the diffraction intensity profile from the electron microscope film, an optical negative film blackness reading device (for example,
Joyce-LoeblChromoscan 3) is used.

[0029] Crystal orientation ratio = 2θ (fiber center) / 2θ (fiber surface) Formula 2

The moisture content of the fiber is determined by allowing the fiber to stand in an environment of 20 ° C. and a relative humidity of 65% until no change in weight is observed, and then weighing it. That is, the weight of the fiber is weighed using an analytical balance, and the fiber is left for 30 minutes in an electric oven adjusted to 230 ° C. to remove water in the fiber and then weighed again. Equilibrium moisture content is evaluated using the formula shown in Formula 3.

Equilibrium moisture content = 100 × (fiber weight when reaching equilibrium-fiber weight after drying) / fiber weight after drying [%]

The wear resistance was evaluated in accordance with JIS L1095-7.10.2 by counting the cycles until breakage.
At this time, a tension of 1.0 g / d was applied to the fiber.

<Measurement Method of Small Angle X-Ray Scattering> The evaluation of the void diameter was performed by the following method using the small angle X-ray scattering method. The X-rays used for measurement are rotor flex RU manufactured by Rigaku Corporation.
It was generated using -300. A copper anticathode was used as a target, and the operation was performed at a fine focus of 30 kV x 30 mA. The optical system was a point-focusing camera manufactured by Rigaku Corporation, and the X-rays were monochromatic using a nickel filter. The detector is
Imaging plate (FDL U manufactured by Fuji Photo Film Co., Ltd.)
RV) was used. Distance between sample and detector is 200mm to 350m
Any suitable distance between m is acceptable.

Helium gas was filled between the sample and the detector in order to suppress disturbing background scattering from air and the like. The exposure time was 2 hours to 24 hours. Digital micrography (FDL5000) manufactured by Fuji Photo Film Co., Ltd. was used to read the scattering intensity signal recorded on the imaging plate. The data obtained are the Guineer plots for the scatter intensity I in the equatorial direction after background correction (the natural logarithm ln (I) of the scatter intensity after background correction is calculated for the square k ² of the scatter vector). Created). Where the scattering vector k is k = (4π /
λ) sin θ, λ is the X-ray wavelength 1.5418Å, θ is the scattering angle 2θ
Is half of.

Tensile strength was 4.0 using the above-mentioned manufacturing method.
GPa, preferably 4.1 GPa or more, tensile modulus of 1
It is possible to produce a polybenzazole fiber suitable for a fishing line having 40 GPa or more, preferably 150 GPa or more and an elongation of 5.5% or less.

It is effective to add an oil agent for the purpose of improving the post-processability. The type of oil agent used in the present invention may include a component acting as a lubricant. It goes without saying that an emulsifier, a stabilizer and the like are used in combination if necessary. As components contained in the oil agent, animal oils, vegetable oils, fatty acid esters, hydrocarbons, higher alcohols, neutral oils such as higher fatty acids, soaps, sulfuric acid esters, sulfonic acids, phosphoric acid esters, surfactants such as ether derivatives, And mixtures thereof, silicone oil, etc. can be used. The oil agent can be applied at one place or at two or more places at the same time during the process from the spinneret to the final winding, and can be performed at any place. It is preferably applied after solidification. If a heat treatment step for increasing the elastic modulus is further required, it is preferable to add a finishing agent after the heat treatment step.

The method of applying the oil agent to the yarn includes spray application in which the oil agent is atomized, dip application through the oil agent bath,
Any method such as kiss roll application or guide application may be used.
An oil agent may be added to the coagulation bath. The adhesion amount of the oil agent is 0.05 to 7.0 with respect to the dry weight of the fiber to which the oil agent is applied.
Weight% is good. If it is less than 0.05% by weight, the oil agent does not sufficiently cover the fiber surface, and if it is more than 7.0% by weight, an excessive amount of the oil agent scatters, which is not preferable. More preferably 0.
It is 1 to 3.0% by weight. Most preferred is 0.3-
It is 2.0% by weight.

When it is necessary to remove the oil agent after applying the oil agent, an oil agent removing step may be provided in a separate step. The fine powder insoluble in the oil agent means that which acts as a solid lubricant. For example, diameter 10m
Colloidal silica or colloidal alumina of μ or less, or titanium oxide or calcium carbonate of several hundred mμ or less in diameter
Silica gel, calcium phosphate, talc, clay, mica, graphite, molybdenum sulfide and the like having a diameter of several μ can be used. It is necessary that these are smaller than the single yarn diameter in the yarn. The fine powder acts as a solid lubricant on the fiber surface,
It has an effect of preventing adhesion between fibers and an effect of improving water resistance by preventing contact of water. The amount of these fine powders deposited is preferably 5.0% by weight or less based on the dry weight of the fibers. If it is 5.0% by weight or more, the effects of water resistance and adhesion prevention reach the ceiling, which is not preferable. 1.0% by weight
The following is more preferable. Most preferably 0.5
It can be said that the content is less than or equal to weight%.

The PBZ fibers described above may be monofilaments or multifilaments and are not particularly limited. When it is used as a multi-filament, it is possible to appropriately twist it, or to perform processing such as bonding each single fiber with a resin. In any case, the tensile strength is 4.0 GPa or more and the initial tensile elastic modulus is 140.
By producing a fishing line using PBZ fibers characterized by having a surface structure that is dense and has a ductility of not less than GPa and not more than 5.5%, higher strength, higher elastic modulus and lower elongation than ever before. It is possible to obtain a fishing line that can maintain the characteristics of 1. Therefore, when the fishing line of the present invention is a Harris line, it is hardly perceived by a fish, can bear the weight of a large fish, and exhibits a performance in which Harris breakage is extremely small. On the other hand, when the yarn is used, it is possible to make it much finer than conventional ones, so it is supple and has a low resistance due to the flow, so it is difficult to flow in tidal currents, and the physical properties of the yarn are high elastic modulus and low. Atari has very good performance because of its elongation.

[0040]

EXAMPLES Example 1 Polyparaphenylene benzobisoxazole 14.0 (weight by weight) obtained by the method disclosed in US Pat. No. 4533693 and having an intrinsic viscosity measured with a methanesulfonic acid solution at 30 ° C. of 24.4 dL / g. %) And a polyphosphoric acid having a phosphorus pentoxide content of 83.17% were used for spinning. The dope was passed through a metal mesh filter material, then kneaded and defoamed with a biaxial kneading device, and then the pressure was raised to maintain the polymer solution temperature at 170 ° C. and from a spinneret having 167 holes. After spinning at 170 ° C and cooling the discharged yarn using cooling air at a temperature of 60 ° C, it is further cooled naturally by 40
The discharged yarn was cooled to 0 ° C and then introduced into a coagulation bath. Fibers were prepared using ethanol at a temperature of -10 ° C as a coagulating liquid. Next, the fiber was wound around a gozette roll, the yarn was washed with ion-exchanged water in a second extraction bath at a constant speed, and then the fiber was immersed in a 0.1 N sodium hydroxide solution for neutralization. After washing with a washing bath, wind it up and
It was dried in a drying oven at 0 ° C. and allowed to stand until the moisture content in the fiber became 2% or less. Further tension 5.0g / d, temperature 6
Heat treatment was performed for 2.4 seconds at 00 ° C. The fiber thus obtained was used as a raw yarn for producing a composite yarn. This fiber has a crystal orientation angle of 0.77 degrees, a mean square roughness of 14.2 nm, a fineness of 250 denier, a strength of 5.2 GPa and an elastic modulus of 160 GP.
It was a. A water resistance test of the obtained PBO fiber was 98%. When the performance as a fishing line was judged by an actual fishing experiment from a practical point of view, the attrition property was extremely good, and the number of Harris breaks was 11 times in 3 days. Water resistance test: The tensile strength in a wet state was used as a measure for evaluating water resistance. After the test piece was immersed in water (20 ° C.) for 1000 hours, the sample was taken out of the water and the strength was measured within 1 minute.

Comparative Example 1 Fiber surface mean square roughness is 24
nm, the crystal orientation angle of the fiber surface is 1.5 degrees, the equilibrium moisture content is 0.7%, and the cycle until breakage in the abrasion test is 493.
A fishing line was produced in the same manner as in Example 1 except that PBO fiber having a void diameter of 21.2Å was used four times. This P
The water resistance of the BO fiber was 79%. Further, when a fishing experiment was conducted at the same time as Example 1, the attrition gradually deteriorated, and the number of Harris breaks was 3
It was recognized 18 times a day.

As can be seen from the comparative examples described above, P
By making the BO fiber surface structure dense, without impairing the excellent high strength and high elastic modulus properties of the PBO fiber,
It can be seen that hydrolysis resistance, which is the biggest drawback, can be improved, and excellent characteristics as a fishing line can be maintained for a long time.

[0043]

According to the present invention, the excellent characteristics of PBZ fiber,
That is, it was possible to obtain a fishing line that utilizes the excellent properties of high strength, high elastic modulus, and low elongation, improves the hydrolysis resistance, and can maintain the excellent properties for a long period of time.

Claims (5)

[Claims] 1. A fishing line characterized by comprising polybenzazole fibers having a mean square roughness of 20 nm or less on the fiber surface, and containing lubricating oil or fat or a resin component in an amount of 0.9 wt% or more between the fibers. 2. The polybenzazole fiber has a crystal orientation angle of 1.3 degrees or less on the surface of the fiber.
The listed fishing line. 3. The equilibrium water content of the polybenzazole fiber is 0.
The fishing line according to claim 1, wherein the fishing line is 6% or less. 4. The fishing line according to claim 1, wherein the polybenzazole fiber has a cycle of up to 5200 cycles until it breaks in the abrasion test. 5. The void diameter of the polybenzazole fiber is 25.
The fishing line according to claim 1, wherein the fishing line is 5 Å or more.