JPH0931748A - High-strength polyamide monofilament and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain polyamide monofilaments having high tensile strength, high knot strength, and excellent wear resistance or impact resistance on a hard rough surface, especially combinedly having properties required for a fishing gut. SOLUTION: This high-strength polyamide monofilament comprises >=80wt.% of capramide unit and simultaneously satisfies 4.0-8.0 relative viscosity (ηr ), <=8.0 (Mw /Mn ), a ratio of weight-average molecular weight (Mw ) to number- average molecular weight (Mn ), >=0.05mm filament diameter (D) and >=45×10<-3> birefringence (Δn). The high-strength polyamide monofilament is obtained by subjecting a capramide-based polyamide having <=8.0 (Mw /Mn ), a ratio of weight- average molecular weight (Mw ) to number-average molecular weight (Mn ), >=4.5 relative viscosity in sulfuric acid (ηr ) and <=0.05wt.% water content to a melt spinning and to drawing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide monofilament suitable for fishing lines and fishing nets and a method for producing the same, and more particularly, it has particularly high tensile strength and knot strength, and flex fatigue resistance. The present invention also relates to a polyamide monofilament having improved abrasion resistance and suitable for fishing lines and fishing nets, and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Polyamide monofilaments are widely used as fishing lines and fishing nets, but there is always a demand for further improvements in catchability, operability and durability.
Therefore, as a polyamide monofilament, strength,
Studies have been conducted to improve transparency, flexibility, and durability such as abrasion resistance and bending fatigue resistance. Recently, there has been a demand for thinner monofilaments and high-strength monofilaments having high tensile strength and knot strength.

As methods for producing high-strength monofilaments, methods such as Japanese Patent Publication No. 54-43610 and Japanese Patent Publication No. 58-144111 have been proposed.

Japanese Examined Patent Publication No. 54-43610 discloses, for example, a method of treating a surface layer of a nylon monofilament stretched at least 4.5 times with a swelling agent, a method of applying a same or different polymer solution, and partial melting. Surface layer orientation is reduced by applying one or more treatment methods selected from treatment methods and the like, and the diameter is about 0.48 mm (No. 8).
Describes the example in which the tensile strength was 7.9 g / d and the knot strength was 5.8 g / d.

According to Japanese Patent Laid-Open No. 58-144111, melt-spinning is carried out using a capramid copolymerized polymer having a relative viscosity (ηr) of 3.4 and a polycapramide component of 85% by weight or more, and after cooling. In a high temperature polyethylene glycol bath, by multi-stage stretching under specific conditions,
For example, it is described that a tensile strength of 10.5 g / d and a knot strength of 8.3 g / d were obtained with a monofilament having a diameter of 0.29 mm (No. 3.0).

When used as fishing line, the monofilament is liable to wear due to rock misalignment or the like, causing a phenomenon such as shrinkage or breakage. Highly effective monofilaments have been demanded. Therefore, for example, Japanese Patent Laid-Open No. 3-2711
No. 8 publication is proposed. According to JP-A-3-27118, a high-viscosity polyamide copolymer polymer is melt-spun, cooled and solidified, and treated in a state of undrawn yarn under a specific condition by a heat treatment apparatus filled with steam. A method for producing a two-layer structured yarn having a surface layer low-orientation structure by carrying out multi-stage drawing after that is disclosed, for example, using a polymer having a relative viscosity of 8.5 and a diameter of 0.205.
mm (equivalent to No. 1.5) monofilament with tensile strength of 1
It is described that the physical properties of 2.1 g / d, knot strength 9.8 g / d, and wear fatigue cutting number 435 times were obtained.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Japanese Laid-Open Patent Publication No. 43610 and Japanese Laid-Open Patent Publication No. 58-144111 are considerably excellent techniques for improving the strength of a monofilament, but recently, higher strength is required, and as described above, rock slip, etc. Therefore, it has been difficult to sufficiently meet the demand by the above-mentioned technique, because the one having improved durability against is demanded.

Further, Japanese Patent Laid-Open No. 3-27118 discloses a technique of improving not only strength but also abrasion resistance, but since the surface has a low orientation by steam and has a flexible structure, it is rubbed with a hard rough surface. In this case, problems such as crimp and thread breakage are likely to occur,
It was hard to say that the technology was sufficient.

Further, recently, the demand for higher strength including improvement in wear resistance has been increasing more and more, and it has been difficult for the above-mentioned technology to sufficiently meet the demand.

Therefore, the present invention solves the above-mentioned drawbacks of the prior art, has high tensile strength, high knot strength, and is excellent in wear resistance and impact resistance on a hard rough surface, and is particularly suitable for Tegus. The main object of the present invention is to provide a polyamide monofilament having the required characteristics of 1. At the same time, another object is to provide a manufacturing method suitable for industrially manufacturing the polyamide monofilament.

[0011]

Means for Solving the Problems As a result of various studies to achieve the above object, the present inventors have found that the weight average molecular weight (Mw)
The ratio (Mw / Mn) between the number average molecular weight (Mn) and the number average molecular weight (Mn) is 8.0.
Use a high-viscosity polymer that is small and has a sharp molecular weight distribution and is uniform and has a specific range.
The present inventors have found that a high-strength monofilament satisfying the above-mentioned required characteristics can be easily obtained industrially by carrying out spin-drawing under specific conditions, and completed the present invention.

In other words, in order to achieve the above object, the polyamide monofilament of the present invention is a polyamide monofilament having 80% by weight or more of a capramid unit and a relative viscosity (ηr) of 4.0 or more and 8.0 or less, Ratio (M) of weight average molecular weight (Mw) to number average molecular weight (Mn)
w / Mn) is 8.0 or less, the filament diameter (D) is 0.05 mm or more, and the surface layer amorphous molecular orientation degree (Fb) is 0.
It is characterized by simultaneously satisfying conditions of 5 or less and birefringence (Δn) of 45 × 10 ⁻³ or more. Further, the coefficient of static friction between filaments is preferably 0.13 or less.

Further, the production method is a method for producing a polyamide monofilament having a diameter (D) of 0.05 mm or more by melt-spinning a polyamide having 80% by weight or more of a capramide unit to obtain a polyamide to be melt-spun. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 8.0 or less, the relative viscosity of sulfuric acid (ηr) is 4.5 or more, and the water content is 0.05 weight. % Polyamide or less, and melt spinning drawing is 2
Melt at 80-330 ° C to spin out monofilament,
Temperature 150-400 ℃, just under the spinneret, length 1
It is passed through a high temperature atmosphere of 5 to 300 mm and immediately passed through a low temperature liquid having a temperature of 40 ° C. or lower to be rapidly solidified, and then taken off at a speed of 2 to 50 m / min without steam treatment, followed by birefringence of 45. It is characterized in that it is carried out by a method in which multi-stage hot stretching is carried out at a magnification of × 10 ⁻³ or more, and relaxation heat treatment is carried out between the multi-stage hot stretching.

The polymers used to produce the high strength polyamide monofilaments of the present invention are polycapramide (nylon 6), polyhexamethylene adipamide (nylon 66), polytetramethylene adipamide (nylon 4).
6), polyhexamethylene sebacamide (nylon 61
0), polydodecamide (nylon 12), homopolymer such as polyhexamethylene isophthalamide, or a copolymerized polyamide or a mixed polyamide containing at least one of the above polyamide components and having a copolymerization ratio or a mixing ratio of 80% by weight or more. . Above all, when using the monofilament obtained by the method of the present invention for fishing line or fishing net,
80% by weight of nylon 6 homopolymer or nylon 6 component
The copolyamide containing the above is most preferable.

The polycapramide type monofilament of the present invention has a relative viscosity (ηr) of 4.0 or more and 8.0 or less and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 8 A high molecular weight polymer having a birefringence (Δn) showing the degree of orientation of the monofilament as a whole of 45 × 10 ⁻³ or more, which is highly oriented, and is a non-filament of the monofilament surface layer portion. The degree of crystal molecule orientation (Fb) is 0.5 or less, which is extremely low. More preferably, it has a feature that the coefficient of static friction is small.

As a result of having this feature, it was possible to realize a polyamide monofilament having high tensile strength and knot strength in a wide range of monofilament diameter, and excellent flex fatigue resistance and abrasion resistance.

The polyamide monofilament of the present invention is
80% by weight or more is composed of a polycapramide-based polymer containing a capramide unit, and is a polycapramide homopolymer, or a capramide-based copolymerized polymer containing 80% by weight or more of a capramide unit and 20% or less of a hexamethylene adipamide unit. If the amount of the capramide unit is less than 80% by weight, the crystallinity will be too low, and it will be difficult to obtain a high-strength monofilament.

The polyamide monofilament of the present invention has a remarkably high molecular weight and a relative viscosity (ηr) of 4.0 or more and 8.0 or less. Especially 4.5-7.5 is preferable.
When ηr is less than 4.0, strength and durability are insufficient and sufficient effects cannot be obtained. On the other hand, in the case of a high-viscosity polymer having an ηr of more than 8.0, the melt viscosity is so high that melt fracture is likely to occur and knotting is likely to occur, so that it is necessary to considerably reduce the spinning speed, resulting in poor productivity and industrial production. Have difficulty.

The polyamide monofilament of the present invention is mainly characterized by having a high molecular weight and a small molecular weight distribution. When the molecular weight distribution is small, the content of the low molecular weight polymer is small, so that it is easy to increase the strength, and further the rigidity is increased and the wear resistance is improved.

The small molecular weight distribution means that the ratio (Mw / M) between the weight average molecular weight (Mw) and the number average molecular weight (Mn).
It is represented by n) being 8.0 or less, and particularly 3.5 to 8.0. When Mw / Mn exceeds 8.0, the molecular weight distribution becomes too wide and the content of low molecular weight polymer increases, so it is difficult to increase the strength even with a high viscosity polymer, and the rigidity is poor. It is not easy to sufficiently increase wear resistance.

The polyamide monofilament of the present invention has a diameter (D) of 0.05 mm or more. If the thickness is less than 0.05 mm, the rigidity is insufficient and it is unsuitable for use as fishing line or fishing net thread.

The polyamide monofilament of the present invention has a high birefringence (Δn) of 45 × 10 ⁻³ or more in terms of fiber structure, while the surface layer amorphous orientation degree (Fb) is 0.5 or less, usually. Has a remarkably low value of 0.3 or less. That is, it is a high molecular weight polyamide monofilament having ηr of 4.0 or more and 8.0 or less, and has a fiber structure having both high birefringence and low degree of surface layer amorphous molecular orientation.

The surface layer portion having a low degree of amorphous molecular orientation according to the present invention usually means a portion having a thickness of 10 μm or less, particularly 2 to 5 μm from the surface layer. When the surface layer portion having a low degree of orientation of amorphous molecules is as thick as 10 μm or more, it tends to be difficult to achieve high strength.

The high birefringence indicates that the molecular chains are well oriented in the fiber axis direction, and contributes to the development of high tensile strength. On the other hand, the low degree of amorphous orientation in the surface layer means that a flexible layer is formed on the surface layer, and protects the structure that exhibits high tensile strength in the inner layer portion. As a result, high knot strength is likely to develop. Further, since the coefficient of static friction is small, it is easy to knot when forming a knot, and because the surface has a flexible structure, the knot is tightly tightened, and once knotted, it is difficult to loosen. As a result, high knot strength is likely to develop.

The polyamide monofilament of the present invention having the above-mentioned polymer characteristics and fiber structural characteristics at the same time has high tensile strength and knot strength, and excellent flex fatigue life and abrasion resistance. The tensile strength, knot strength and flexural fatigue life all change depending on the diameter of the monofilament and decrease as the diameter increases, but the polyamide monofilament of the present invention has a low ratio of strength decrease and flexural fatigue life with increasing diameter. It has excellent characteristics.

The fact that the tensile strength and the knot strength are high at the same time means that
For example, when used as fishing line, it is important to maintain high strength regardless of how to tie.

Further, in order to exhibit the excellent wear resistance of the monofilament of the present invention, it is greatly contributed that the rigidity of the fiber surface is increased by being composed of the high polymerization degree polymer having a small molecular weight distribution. . Further, it has a small coefficient of static friction and contributes to having excellent wear resistance against abrasion due to rock misalignment. For example, when the cutting wear resistance is evaluated by the sandpaper method, the polyamide monofilament of the present invention can exhibit a cutting wear resistance of about 2.5 times or more compared with the conventional one.

Another characteristic of the polyamide monofilament of the present invention is that it has high rigidity while being flexible against bending. This means, for example, when used as fishing line,
It is possible to simultaneously satisfy the contradictory characteristics that it has a characteristic of easily sensing the occurrence of a winding, and at the same time, it is hard to be wound around a reel or the like.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the polyamide monofilament of the present invention having the characteristics useful as a fishing line or a fishing net line can be produced by the following method.

That is, the relative viscosity (η
A polycapramide-based polymer having r) of 4.0 or more and 8.0 or less is used. The polymer composition is a polycapramide homopolymer or a capramide-type copolymerized polymer composed of 80% by weight or more of capramide units and 20% by weight or less of hexamethylene adipamide units, and the polymer is a weight average molecular weight (Mw) in all cases. To the number average molecular weight (Mn) (Mw /
It is necessary that Mn) is 8.0 or less and the molecular weight distribution is small.

Such a polymer has a relative viscosity (ηr) of 2.
It can be produced by solid phase polymerizing a polymer solution-polymerized to a level of 5 or more, usually 2.5 to 3.5, at a temperature 40 to 60 ° C. lower than the melting point of the polymer for a long time.

The solid-phase polymerization conditions are 150 to 18
Conditions such as a temperature of 0 ° C. and 10 to 350 hours may be taken, and it is preferable not to use a polymerization accelerator such as a phosphorus compound.

The above-mentioned polymer of the present invention is melt-spun by an extruder type spinning machine at a polymer temperature of 280 ° C to 320 ° C, preferably 290 ° C to 305 ° C. The polymer temperature is set so that the apparent melt viscosity (μ) is 5000 poise or more,
Preferably, it may be set to a level that can maintain 7,000 poise.

The water content of the polymer used is as low as 0.05% by weight or less, preferably 0.01% by weight or less.

By taking the above spinning conditions, the high strength polyamide monofilament of the present invention can be easily produced.

The monofilament after spinning is 150 to 4
After passing through an atmosphere having a bottom length of 15 to 300 mm filled with an inert gas such as nitrogen gas or superheated steam heated to 00 ° C., it is immediately rapidly cooled in a cooling liquid at 40 ° C. or less. The atmosphere under the base is a cylinder (below,
It may be performed by providing a heating cylinder) and blowing the above-mentioned inert gas.

Examples of the cooling liquid include water, aliphatic hydrocarbons such as n-hexane, aromatic hydrocarbons such as toluene, alicyclic hydrocarbons such as decalin, halogenated hydrocarbons, and mixtures thereof. A liquid inert to polyamide is used.

The cooled undrawn yarn monofilament is
If necessary, an inert liquid such as water below 20 ° C or 20
The refrigerant on the surface of the monofilament is removed by an inert gas such as nitrogen or air having a temperature of not higher than 0 ° C., and the monofilament is continuously sent to the first drawing zone.

The atmosphere (bath) at the time of stretching is, for example,
A heating medium bath of polyethylene glycol, glycerin, silicone oil or the like, a dry heat gas bath, a superheated or pressurized steam bath, or the like may be used.

The first stage stretching is carried out at a magnification of 3.0 times to 7.0.
The range may be doubled, preferably 4.0 to 6.5 times. If the draw ratio is less than 3.0 times, it is difficult to fix the draw point, and an unstable yarn containing draw unevenness where drawn yarn and undrawn yarn coexist is likely. If the draw ratio exceeds 7.0, the yarn It often breaks easily, making stretching difficult.

The stretching temperature may be a temperature of (Tm-100 ° C) or higher. Tm is a melting point (° C.) of polyamide, and crystal melting when a chip or a bulk polymer is measured at a temperature rising rate of 10 ° C./min using a SSC5200 type differential scanning calorimeter manufactured by Seiko Denshi Kogyo Co., Ltd. It may be expressed by the peak temperature (however, in the case where melting peaks overlap each other, the peak temperature is the most exothermic value) (° C).

If the stretching temperature at the first stage is lower than (Tm-100 ° C), it is difficult to fix the neck point in the bath during stretching, and stretching unevenness is likely to occur, which is not preferable. Regarding the upper limit of the drawing temperature in the first stage, when a heat medium having high thermal efficiency (for example, liquid heat medium) is used, the melting point of the polyamide monofilament is preferably equal to or lower than that of the heat medium (for example, dry heat gas). When used, temperatures well above the melting point of the polyamide monofilaments are allowed. These temperature conditions are the same as the upper limit temperature in the subsequent stretching and heat treatment. After the first stage of stretching, 80 from the stretching temperature
At the same time as cooling with warm water or an inert gas lower than ℃, the heat medium is removed, and the water droplets adhering to the surface are removed with air.

Thereafter, a relaxation heat treatment is subsequently performed. The relaxation heat treatment has a magnification of preferably 0.8 to 1.0 or less, particularly preferably 0.90 to 0.98. The processing temperature is (Tm
It may be performed at -120 ° C) or higher.

By this relaxation heat treatment, the unstable structure inside the fiber generated in the first drawing step is corrected and at the same time the degree of orientation of the surface layer amorphous molecules is lowered to form a flexible structure, and fine irregularities are formed on the surface. Can be formed substantially uniformly to form a surface having a small coefficient of static friction, and durability and knot strength can be improved.

If the heat treatment temperature is lower than (Tm-120 ° C.), the degree of orientation of amorphous molecules in the surface layer tends to increase, which is not preferable. If the processing magnification is less than 0.8, yarn slack is likely to occur during processing, and thus thread breakage frequently occurs and operability is likely to deteriorate. If the treatment ratio exceeds 1.0, a substantial tension heat treatment is performed, and the degree of orientation of the surface layer amorphous molecules becomes high, and it is difficult to obtain the high knot strength yarn of the present invention.

After the relaxation heat treatment, the monofilament continues to have a birefringence of 45 × 10 at a temperature of (Tm-90 ° C.) or higher.
^-Re -stretching at a draw ratio of ^-3 or more (stretching after the second stage)
do it. It is preferable that the total magnification is at least 5.5 times or more. The total draw ratio here is the product of the first draw ratio and the draw ratio during re-drawing.

After the re-stretching was completed, the stretching bath temperature was adjusted to 60.
At the same time as cooling with warm water or an inert gas having a temperature lower than ℃, the heat medium attached is removed, and water droplets and the like attached to the surface are removed with air.

Subsequently, a relaxation heat treatment is performed. The temperature is preferably (Tm-150 ° C) or higher, and the relaxation ratio is preferably 0.80 to 0.98, particularly 0.90.
To 0.98 is more preferable. This relaxing heat treatment corrects the unstable structure (stress strain, cracks, etc.) inside the fiber generated in the drawing step. After the relaxation heat treatment is completed, a finishing oil containing an antistatic agent and a lubricant as a main component is attached and wound up.

The polyamide monofilament of the present invention contains, for example, additives such as a filler, a dye, a light stabilizer, an ultraviolet absorber, an antioxidant, a crystallization inhibitor and a plasticizer within a range that does not impair the effects of the present invention. be able to.

The polyamide monofilament of the present invention obtained by the above method has the above-mentioned characteristics of physical properties and fiber structure.

[0051]

EXAMPLES Examples will be described below. The measurement methods and definitions in the present invention are as follows.

(A) Relative viscosity (ηr): 9 g of sample 1
Dissolve in 100 ml of 8% sulfuric acid and use an Ostwald viscometer to
It was measured at 5 ° C.

(A) Number average molecular weight (Mn) and weight average molecular weight (Mw): Measured by GPC-LALLS method. The GPC is 201D type gel permeation chromatograph manufactured by Waters, and the column is TSK-ge manufactured by Toyo Soda Co., Ltd.
1-GMHXL and sodium trifluoroacetate were used as the solvent. LALLS is CMX-made by Chromatix.
633n using 100 type low angle laser light scattering photometer
m (He-Ne) wavelength, the filter is 0.45μ-Fluoro Pore FP manufactured by Sumitomo Electric Industries, Ltd.
-045 was used.

(C) Amorphous molecular orientation degree (Fb): A sample was immersed in a 0.2 wt% aqueous solution of a fluorescent agent "whitexRP" (manufactured by Sumitomo Chemical Co., Ltd.) for 2 hours, washed with water and dried with air. The relative fluorescence intensity in the fiber axis direction (I ₀ ) and the relative fluorescence intensity in the direction perpendicular to the fiber axis (I ₉₀ ) were measured with a FOM-1 type fluorescence photometer manufactured by JASCO Corporation, and the following formula was used. It is the calculated value. Fb = 1- (I ₉₀ / I ₀ ).

(D) Birefringence (Δn): Nippon Kogaku Co., Ltd.
Using a POH type polarization microscope manufactured by, a white light was used as a light source, and the measurement was performed by an ordinary compensator method.

(E) Tensile strength (TT) and knot strength (KT): Measured according to JIS-L1070-5.1.1 (standard tensile strength and elongation) and (standard knot strength and elongation). I did.

(F) Flexural fatigue life (Nb): Flexural fatigue life measured by a bending fatigue measuring machine manufactured by Toyo Seiki Seisaku-sho, Ltd. under a tension of 3 g / d load, and the number of times of flexion at the time of bending fatigue cutting is obtained. And

(G) Abrasion resistance (Nμ): Diameter 50 mm
A sample of 320 mesh sandpaper was applied to the surface of the roll and a load of 0.05 g was applied per denier,
It is set on the sandpaper so that the contact angle is 90 °, and the roll is rotated at a rotation speed of 180 times / minute. The number of revolutions until the sample was cut by abrasion was measured to determine the number of abrasion-resistant fractures.

(H) Apparent viscosity (μ): CFT-500C type flow tester manufactured by Shimadzu Corporation was used, and the diameter was 0.5.
A molten polymer is discharged at 260 ° C. from a nozzle of mmφ and a length of 1.0 mm to measure the melt viscosity, and the shear rate is 1000.
The apparent viscosity in μ / sec was defined as the viscosity (μ).

(V) Melting point: SSC5200 type differential scanning calorimeter manufactured by Seiko Denshi Kogyo Co., Ltd. under nitrogen atmosphere at 10 ° C.
It is the melting absorption peak temperature when measured at a temperature rising rate of / min.

(C) Surface observation: Observation and judgment were performed with a field emission scanning electron microscope (S-800 type manufactured by Hitachi).

(F) Static friction coefficient: MAEDAMFG
The friction tester made by CO (see FIG. 1 and FIG. 2 for the main part) was used, and the measurement was performed by the following method. First, the circular mounting frames 2 having 32 grooves 2a at equal intervals on a pair of circles are arranged in parallel with a length of 24 mm, and the test pieces are provided between the corresponding grooves 2a of the mounting frame 2. A monofilament 1 was fixed in the horizontal direction under tension of 1 g / d one by one at a total of 32 equal intervals to form a cylindrical filament body having a diameter of 32.5 mm. Then, a similar monofilament 1 to be tested is provided substantially in the center of the monofilament 1 having a cylindrical shape with a diameter of 8 mm due to the interposition of the intermediate frame 3.
Suspend at a right angle. Next, a load 4 is hung on one end side of the monofilament 1 to set its initial tension (T0) to 1 g /
d, the other end side is connected to the tension detector 5, and the pair of cylindrical mounting frames 2 is rotated at a rotational speed of 0.0 in the arrow direction (load side).
The tension (T1) generated at the other end by rotating at 2 m / min was measured by the tension detector 5, and the yarn-yarn static friction coefficient ([mu] s) in this case was calculated by the following formula. μs = T1 -T0 / T1 + T0

Example 1 A polycapramide having a sulfuric acid relative viscosity (ηr) of 2.7 obtained by a usual solution polymerization method was subjected to solid phase polymerization at 170 ° C. for 140 hours under a vacuum degree of 0.05 Torr. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 6.3,
A polycapramide having a relative viscosity (ηr) of 6.0, a water content of 0.01% by weight or less, a melting point of 221 ° C. and a polymer property of 7,000 poise was manufactured. This polycapramide homopolymer was spun at a spinning temperature of 3 using an extruder type spinning machine.
Extruded at 00 ° C.

The spun filament was filled with nitrogen gas 3
After passing through a heating cylinder of 00 ° C. and a length of 15 cm, it was cooled with water of 5 ° C. Then, the filament was drawn by a take-up roll at a speed of 10 m / min, and then drawn 4.5 times (one-step drawing) in a polyethylene glycol bath having a length of 15 cm and continuously heated to 200 ° C.

Next, relaxation heat treatment was continuously carried out at a draw ratio of 0.95 times in a polyethylene glycol bath of 210 ° C. and a length of 2 cm, and then continuously in a polyethylene glycol bath of 210 ° C. and a length of 50 cm for 1.4. The second stage drawing was performed with a doubling. The drawn filaments were then passed through a hot water bath having a bath temperature of 90 ° C. and a length of 100 cm at a draw ratio of 0.95 times and then wound with a finishing agent.

The obtained filament has a yarn diameter of 0.207 m.
The relative viscosity (ηr) of the filament at m (No. 1.5) was 5.1.

The birefringence was as high as 56 × 10 ^-3, and the degree of orientation of amorphous molecules (Fb) in the surface layer was as low as 0.10.

A monofilament with good transparency having a tensile strength of 11.6 g / d, a knot strength of 9.66 g / d, a bending fatigue life (Nb) of 394 times, and a wear resistance breakage number (Nμ) of 535 times was obtained. Was obtained. Thread-to-thread static friction coefficient (μs)
Was as small as 0.099.

Table 1 shows the polymer characteristics, spinning conditions and the like, and Table 2 shows the physical properties of the obtained monofilament.

[Examples 2 to 6] Spinning was carried out in the same process as in Example 1 except that the polymer characteristics, spinning conditions and the like were changed as shown in Table 1. The physical properties of the obtained monofilament are shown in Table 2.

Example 7 The same polymer as in Example 1 was used, and the first-stage drawing bath, the heat treatment bath and the second-stage drawing bath were heated by air. Table 1 shows the polymer characteristics and spinning conditions, and Table 2 shows the physical properties of the obtained monofilament.

[Comparative Examples 1 to 6] Spinning was performed by the same process as in Example 1 except that the polymer characteristics, spinning conditions and the like were changed as shown in Table 1. The physical properties of the obtained monofilament are shown in Table 2.

The solid phase polymerization of the polymer in Comparative Example 6 was carried out at 190 ° C. for 100 hours at a high temperature for a short time.

[0074]

[Table 1]

[0075]

[Table 2]

[0076]

[Table 3]

[0077]

[Table 4]

The monofilaments specified in the present invention were obtained in any of Examples 1 to 7 which satisfied the polymer characteristics and the yarn-making conditions specified in the present invention, and had excellent tensile strength, knot strength, flex fatigue resistance and resistance to bending. It could have abradability.

On the other hand, in Comparative Examples 1 to 6, the monofilament specified in the present invention was not obtained, and the intended effect could not be obtained.

That is, in Comparative Example 1, the polymer viscosity was low, and the tensile strength and knot strength were low. In Comparative Example 2, the polymer viscosity was too high and knotting occurred. In Comparative Example 3, the stretching ratio was low, so the birefringence was low and the tensile strength and knot strength were low. Comparative Example 4 had no relaxation heat treatment step and had a high degree of amorphous molecular orientation (Fb) and low knot strength. Moreover, the coefficient of static friction between threads was also high. In Comparative Example 5, the stretching temperature was low, and the neck position could not be fixed, resulting in large variations in strength. In Comparative Example 6, the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) was large, and the wear resistance was poor.

[0081]

INDUSTRIAL APPLICABILITY The polyamide monofilament of the present invention is excellent in tensile strength, knot strength, bending fatigue resistance, abrasion resistance and the like, and is therefore suitable as a fishing line and fishing line. In particular, it is possible to provide a product having excellent catchability, operability, and durability due to the above-mentioned excellent mechanical properties and properties such as transparency and flexibility.

Further, the polyamide monofilament of the present invention makes use of its excellent characteristics, and is used for applications other than fishing line and fishing net, such as brush material, cord, rope, cable,
It can also be used for strings.

[Brief description of drawings]

FIG. 1 is a front view of a main part of a measuring device used for measuring a coefficient of static friction (μs) between threads in the present invention.

FIG. 2 is a side view of a main part of the measuring device shown in FIG.

[Explanation of symbols]

1, 1 ': sample monofilament, 2: circular mounting frame, 2a: groove, 3: intermediate frame, 4: load, 5: tension detector

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area A01K 75/00 A01K 75/00 C 91/00 91/00 Z

Claims (7)

[Claims] 1. A polyamide monofilament comprising 80% by weight or more of a capramid unit, a relative viscosity (ηr) of 4.0 or more and 8.0 or less, and a weight average molecular weight (M
w) to number average molecular weight (Mn) ratio (Mw / Mn) is 8.0 or less, filament diameter (D) is 0.05 mm or more, surface layer amorphous molecular orientation degree (Fb) is 0.5 or less, and ,
A high-strength polyamide monofilament characterized in that the birefringence (Δn) simultaneously satisfies the condition of 45 × 10 ⁻³ or more. 2. The coefficient of static friction between filaments is 0.1.
The high-strength polyamide monofilament according to claim 1, which is 3 or less. 3. A polyamide comprising 80% by weight or more of capramide units is melt-spun and drawn to have a diameter (D) of 0.
In the method for producing a polyamide monofilament having a size of 05 mm or more, the polyamide to be melt-spun is mixed with a weight average molecular weight (M
w) to a number average molecular weight (Mn) ratio (Mw / Mn) of 8.0 or less, sulfuric acid relative viscosity (ηr) of 4.5 or more, and a moisture content of 0.05% by weight or less polyamide, And, melt spinning was melted at 280 to 330 ° C. to spin out a monofilament, and a temperature of 150 was provided just below the spinneret.
~ 400 ℃, 15 ~ 300mm length of the high temperature atmosphere, immediately passed through a low temperature liquid of 40 ℃ or less to rapidly solidify, then without steam treatment 2-50m
The method is characterized in that it is carried out at a rate of / min, followed by multi-stage hot drawing at a magnification such that the birefringence is 45 × 10 ⁻³ or more, and relaxation heat treatment between the multi-stage hot drawing. A method for producing a polyamide monofilament that is strong. 4. A sulfuric acid relative viscosity (ηr) of 2.5 to 3.
The ratio (Mw / M) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) produced by carrying out solid-phase polymerization of the polyamide of No. 5 at 150 to 180 ° C. for 10 to 350 hours.
The polyamide according to claim 3, wherein n) is 8.0 or less, relative viscosity (ηr) of sulfuric acid is 4.5 or more, and water content is 0.05% by weight or less, is subjected to melt spinning. Manufacturing method of monofilament. 5. The temperature of the first-stage stretching in the multi-stage stretching is set to a temperature of [melting point of polymer (Tm) -100 ° C.] or more, and relaxation heat treatment is performed after the first-stage stretching. Item 5. A method for producing a polyamide monofilament according to Item 3 or 4. 6. The relaxation heat treatment is carried out by [melting point of polymer (T
m) -120 [deg.] C.] or higher and a magnification of less than 1.00 times, the method for producing a polyamide monofilament according to claim 5. 7. Following the relaxation heat treatment, a temperature of [melting point of polymer (Tm) −90 ° C.] or higher and birefringence of 45 ×
The method for producing a polyamide monofilament according to claim 5 or 6, wherein the second stage or more of the heat drawing is performed at a draw ratio of 10 ^-3 or more.