Monofilament and fishline

Abstract

To provide a fluororesin-based monofilament which is less likely to exhibit curling tendency even when wound around a reel for a prolonged period while having high intensity and high wear resistance and which cannot be attained by prior art.SOLUTION: In a monofilament including a fluororesin as the main component, a resin component involved in the monofilament has a crystallinity of 40% or over and 70% or under and a Raman peak intensity ratio represented by the formula (1) in a Raman spectrum of 5 or over and 12 or under; (1) a band relative intensity in a polarization measurement parallel to a fiber direction (I1275 / I2975) / a band relative intensity in a polarization measurement perpendicular to a fiber direction (I1275 / I2975).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a monofilament containing a fluororesin as a main component, which has high strength and abrasion resistance, excellent flexibility, and resistance to curling. [Background technology]

[0002] In the past, fibers used for fishing lines and fishing nets in the fishing industry were made from wild silk thread and silk. However, since the advent of synthetic fibers, nylon, fluororesin, polyolefin, and other fibers are now widely used due to their economy, uniform formability, strength, transparency, and other factors.

[0003] In particular, polyvinylidene fluoride resin, which appeared in the 1970s, is widely used for fishing lines and leader lines because of its strong polymer molecular structure, which makes it resistant to friction and scratches, as well as rubbing against underwater obstacles. It also has low water absorption, making it less susceptible to deterioration, and has less stretch than nylon, making it highly sensitive and easy to detect even the smallest bites from fish. Its refractive index is similar to that of water, making it difficult to see underwater, making it a popular choice among anglers.

[0004] On the other hand, due to the crystallinity and high elastic modulus inherent in the fiber structure, cellulose is stiffer than other synthetic fibers such as nylon. This makes it difficult to tie uniform knots when tying fishing tackle such as hooks and swivels, or tying lines together, which results in reduced strength and requires a certain level of skill from the angler. Furthermore, when used as a fishing line wound onto a reel, cellulose has the disadvantage of easily becoming tangled after being wound onto the spool or reel. Once a tangled line phenomenon known as backlash occurs, the tangled line can become a starting point for frequent backlashes. This rigidity, lack of linearity, and tendency for cellulose to become tangled not only reduces ease of handling, but also causes unnatural movements of lures and baits, resulting in poor fishing results.

[0005] In order to solve these problems, attempts have been made to soften PVdF monofilaments, and one such technique that has already been proposed is monofilament made from a PVdF composition containing a vinylidene fluoride copolymer containing 1% by mass or more of a comonomer component (see, for example, Patent Document 1). However, although these monofilaments are flexible, the inclusion of the copolymer reduces the crystallinity, lowering the strength and melting point of the polymer. As a result, when used as fishing line, frictional heat causes a decrease in physical properties, particularly in resistance to root shear and knot strength, and the resulting monofilaments have not yet been fully satisfactory.

[0006] Furthermore, PVdF fibers with high strength and excellent flex recovery rate, which are obtained by drawing at a specific drawing temperature and ratio, and a method for producing the same, as well as fibers for use in fisheries materials (see, for example, Patent Document 2), have already been proposed. However, although this method provides a high flex recovery rate in a short period of time due to the high degree of orientation, it has not been fully satisfactory in terms of preventing curling when the fiber is wound around a reel for a long period of time.

[0007] Furthermore, vinylidene fluoride resin monofilaments (see, for example, Patent Document 3) have already been proposed that are high-strength and resistant to kink, and are made using raw materials with specific melt flow rates and molecular weight distributions. However, there are limitations on the raw materials that can be used, and the need to mix specific raw materials means that there are significant limitations on the equipment involved. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] WO2002 / 064867 publication [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-192327 [Patent Document 3] Patent 5309968 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention solves the above-mentioned problems and aims to provide a monofilament containing a fluororesin as a main component, which has high strength and high abrasion resistance, and is less likely to develop a curl even when wound around a reel for a long period of time, something that could not be achieved with conventional technology. [Means for solving the problem]

[0010] As a result of extensive research to achieve the above object, the present inventors have found that by controlling the crystalline state and orientation state of the polymer constituting the monofilament to a specific structure, it is possible to obtain a fluororesin monofilament that has high strength and high abrasion resistance and is less likely to develop curls even when wound around a reel for a long period of time.

[0011] That is, [1] A monofilament containing a fluororesin as a main component, wherein the resin component contained in the monofilament has a crystallinity of 40% or more and 70% or less, and the Raman peak intensity ratio expressed by formula (1) in the Raman spectrum is 5 or more and 12 or less.

[0012]

number

[0013] [2] The monofilament according to [1] above, wherein the crystallite size of the resin component contained in the monofilament is 6 nm or more and 15 nm or less. [3] The monofilament according to [1] or [2], wherein the fluororesin is a vinylidene fluoride homopolymer. [4] A fishing line made from the monofilament described in [1] or [2] above. [5] A fishing line made from the monofilament described in [3] above. [Effects of the Invention]

[0014] The present invention provides a fluororesin fishing line that has high strength and high abrasion resistance, and is less likely to develop a curl even when wound around a reel for a long period of time. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram of an apparatus for evaluating wear resistance. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described in detail.

[0017] The monofilament of the present invention is a monofilament containing a fluororesin as a main component, and the resin component contained in the monofilament has a crystallinity of 40% or more and 70% or less, and a Raman peak intensity ratio represented by formula (1) in the Raman spectrum of 5 or more and 12 or less.

[0018] The monofilament of the present invention contains a fluororesin as a main component. Here, "containing a fluororesin as a main component" refers to a fluororesin content of more than 50% by mass, preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 100% by mass. The fluororesin used in the present invention refers to a hydrocarbon polymer in which at least some hydrogen atoms have been substituted with fluorine atoms, and is preferably a vinylidene fluoride homopolymer or a copolymer containing 80% by mass or more of a vinylidene fluoride component. When the fluororesin is a vinylidene fluoride copolymer, examples of the copolymerization component include tetrafluoroethylene, trifluoromonochloroethylene, trifluoroethylene, monofluoroethylene, hexafluoropropylene, and mixtures thereof, with hexafluoropropylene being preferred. Furthermore, polyvinylidene fluoride polymers containing 80% by mass or more of a vinylidene fluoride component are preferred because it is easy to control the crystallinity to 40% or more, and vinylidene fluoride homopolymers are particularly preferred.

[0019] The polymerization method for producing the vinylidene fluoride resin preferably used as the fluororesin in the present invention may be emulsion polymerization or suspension polymerization. When flexibility is important as a performance of the monofilament, it is preferable to use an emulsion polymerization product, and when strength is important, it is preferable to use a suspension polymerization product. It is also possible to use a mixture of both to achieve a balance between flexibility and strength.

[0020] To obtain a monofilament that is both high in strength and flexibility, the weight-average molecular weight should be 300,000 or more and 600,000 or less, preferably 330,000 or more and 550,000 or less, and more preferably 350,000 or more and 500,000 or less, which will make it easier to obtain suitable spinnability and strength.

[0021] Furthermore, in the present invention, various additives such as pigments, dyes, light stabilizers, ultraviolet absorbers, antioxidants, crystallization inhibitors, and plasticizers can be added to the fluororesin during the polymerization process, after polymerization, or immediately before spinning, within a range that does not impair the intended performance.

[0022] The resin component contained in the monofilament of the present invention, which contains the above-mentioned fluororesin as a main component, must have a crystallinity of 40% or more, preferably 45% or more. Furthermore, the crystallinity must be 70% or less, preferably 60% or less. If the crystallinity of the resin component contained in the monofilament is less than 40%, the monofilament will lack strength and will not achieve the desired tensile strength and abrasion resistance. Furthermore, the monofilament will have poor shape retention and will be prone to curling. On the other hand, if the crystallinity exceeds 70%, the monofilament will become stiff and difficult to knot. This makes it difficult to form uniform knots when tying with hooks, swivels, or other fishing tackles, or when tying with other lines, resulting in a failure to achieve the required strength. The crystallinity of the resin component contained in the monofilament of the present invention can be measured in the monofilament state using the method described in the Examples. Measurement in the monofilament state is because this characteristic is manifested by the manufacturing method.

[0023] Furthermore, the Raman peak intensity ratio of the monofilament, expressed by formula (1) in the Raman spectrum, must be 5 or more, preferably 6 or more, and more preferably 7 or more. The Raman peak intensity ratio must be 12 or less, preferably 11 or less, and more preferably 10 or less. If the Raman peak intensity ratio is less than 5, the monofilament will have a low degree of orientation, resulting in insufficient strength and failure to achieve the desired tensile strength and abrasion resistance. On the other hand, if the Raman peak intensity ratio exceeds 12, the monofilament will have a high degree of orientation, resulting in stress relaxation when wound around a reel for a long period of time, resulting in a monofilament that is prone to curling. The Raman peak intensity ratio of the resin component contained in the monofilament of the present invention can be measured in the monofilament state by the method described in the Examples. The reason for measuring in the monofilament state is the same as for crystallinity.

[0024] Here, the Raman peak intensity ratio measured by the laser Raman method will be explained in more detail. -1 The Raman band around 1275 cm is due to CH bending vibration. -1 The Raman band around 2975 cm is attributed to the CC skeletal stretching vibration and the CF stretching vibration. -1 The transition moment of the Raman band near 1275 cm is almost perpendicular to the molecular chain, whereas the transition moment of the Raman band near 1275 cm is almost perpendicular to the molecular chain. -1 The Raman band in the vicinity has a transition moment pointing in a direction parallel to the molecular chain. Therefore, the ratio of these two, R = I1275 / I2975, is a parameter that expresses molecular orientation. The larger the Raman peak intensity ratio, the more oriented the molecular chain is in the polarization direction of the measurement. The characteristics of the degree of orientation can be summarized as follows:

[0025] Rp: Relative band intensity (I1275 / I2975) in polarized light measurement parallel to the fiber direction Rd: Relative band intensity (I1275 / I2975) measured in polarized light perpendicular to the fiber direction Rp: The larger the Rp, the higher the degree of orientation in the fiber axis direction.

[0026] Rd: The larger the value, the higher the degree of orientation in the direction perpendicular to the fibers.

[0027] The Raman peak intensity ratio is defined as Rp / Rd, and the higher the ratio, the higher the degree of orientation along the fiber axis. This parameter is 1 when the degree of fiber orientation is 0.

[0028] Furthermore, the crystallite size of the resin component contained in the monofilament is preferably 6 nm or more and 15 nm or less. If the crystallite size is less than 6 nm, the monofilament has poor shape retention and is prone to becoming tangled. On the other hand, if the crystallite size exceeds 15 nm, the monofilament itself becomes stiff and difficult to knot, making it difficult to form a uniform knot when tying with a hook or a hook such as a swivel, or with a line, and as a result, the required strength cannot be obtained. The crystallite size of the resin component contained in the monofilament of the present invention can be measured in the monofilament state by the method described in the Examples. The reason for measuring in the monofilament state is the same as for crystallinity.

[0029] Next, an example of a method for producing the monofilament according to the present invention will be given, but various modifications are possible within the scope of the present invention.

[0030] The monofilament of the present invention can be efficiently produced by the melt spinning method described below. When melting the resin, ordinary conditions using an extruder-type spinning machine can be used, and the melting temperature should be set within a range of the melting point of the resin plus 50 to 110°C. A range of 50 to 90°C above the melting point is particularly advantageous in terms of both ensuring the fluidity of the resin and suppressing thermal degradation. The extrusion pressure of the extruder is preferably 2 to 30 MPa, and more preferably 20 MPa or less in terms of suppressing shear heat generated by the screw. The conditions can be selected appropriately depending on the desired thickness of the monofilament, such as a nozzle hole diameter of 0.1 to 20 mm and a spinning speed of 0.3 to 100 m / min.

[0031] Next, the monofilament spun from the spinneret passes through a short gas zone and is then cooled in a cooling bath. The cooling medium used here is a liquid inert to the resin, typically water, glycerin, or polyethylene glycol, and the cooling medium is preferably at a temperature at least 100°C lower than the melting point of the resin. The gas zone through which the spun monofilament passes is preferably provided with a heat-retention zone heated to an ambient temperature 100 to 150°C above the melting point of the resin. Furthermore, the running distance of the yarn, which is in a room-temperature environment, from the spinneret or the bottom of the heat-retention zone to the surface of the cooling medium is preferably 10 cm or less.

[0032] Furthermore, if the draft ratio, calculated by dividing the speed of the first take-up roll by the linear resin extrusion speed of the die, is set to 15 times or less, preferably 10 times or less, it is easy to obtain monofilaments with a uniform fiber diameter in the longitudinal direction.

[0033] The cooled and solidified monofilament is subsequently sent to the drawing section, and the atmosphere (bath) for drawing and heat setting is preferably a heated heat medium bath such as hot water, polyethylene glycol, glycerin, or silicone oil, a hot gas bath, or a steam bath. The drawing process may be performed in one stage or in multiple stages, but a total draw ratio of usually 4.5 times or more, preferably 5.0 times or more, tends to produce a high-strength monofilament.

[0034] Furthermore, the maximum tension in the stretching process is 50N / mm 2 More than 150N / mm 2 By setting the monofilament in this range, the degree of orientation can be controlled, and the Raman intensity peak ratio can be set to 12 or less. On the other hand, it is preferable that the maximum tension is 50 N / mm 2 If the tension is less than 150N / mm, the monofilament will not be sufficiently oriented and will have low strength. 2 If it exceeds this value, the degree of orientation of the monofilament will be high, the Raman intensity peak ratio will exceed 12, and the monofilament will be prone to curling.

[0035] Here, the time during which maximum tension is applied to the monofilament in the drawing step is preferably 30 seconds or more and 240 seconds or less. By setting the time within this range, the crystallinity of the resin component contained in the monofilament can be controlled to 40% or more and 70% or less. On the other hand, if the time during which maximum tension is applied is less than 30 seconds, crystals will not grow sufficiently, resulting in a monofilament with a low crystallinity and prone to curling. Furthermore, if the time during which maximum tension is applied exceeds 150 seconds, crystals will grow large, resulting in a monofilament that is stiff and difficult to knot.

[0036] After stretching, an appropriate constant length and / or relaxation heat treatment may be carried out as needed to remove stretching strain.

[0037] The monofilament of the present invention may be prepared by adding a colorant to the monofilament to be used, or by coloring or dyeing the monofilament after or during spinning using existing methods. A finishing oil or the like may also be applied to the surface of the monofilament. Furthermore, the cross-sectional shape of the monofilament of the present invention is not necessarily limited to a circular cross-section, but may be any shape such as a triangular cross-section, a quadrangular cross-section, or a multilobal cross-section. [Example]

[0038] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Each item in the examples was measured by the following method. Note that, for measurements where the number of evaluations (n) is not specifically stated, the evaluation was performed with n=1. (1) Crystallinity In accordance with JIS K7122 (1987), a Shimadzu DSC-60 differential scanning calorimeter manufactured by Shimadzu Corporation was used for measurement, and a Shimadzu TA60 was used for data analysis. 20 mg of the monofilament was heated on an aluminum tray from room temperature to 300°C at a heating rate of 20°C / min and held at 300°C for 5 minutes. From the endothermic peak calorific value ΔHm obtained by the measurement and the heat of fusion of perfectly crystalline vinylidene fluoride ΔHm0 (105 J / g), calculation was performed using the following formula. Crystallinity (%)=ΔHm / ΔHm0×100 (2) Raman peak intensity ratio Using a laser Raman spectrophotometer NRS-5100 manufactured by JASCO Corporation, the beam was irradiated in directions parallel to and perpendicular to the longitudinal direction of the fiber. -1 In the Raman spectrum of -1 The relative band intensity of the peak at 1275 cm (I2975) and the peak at 1275 cm (C–C and C–F groups) -1 The relative band intensity (I1275) of the peak at 1275°C was calculated. The ratio of these two was set as R = I1275 / I2975, with the ratio parallel to the longitudinal direction of the fiber being Rp and the ratio perpendicular to the longitudinal direction of the fiber being Rd. The Raman peak intensity ratio was calculated as Rp / Rd. (3) Crystallite size Wide-angle X-ray diffraction measurements were performed on the monofilament surface using a multi-axis X-ray diffractometer SmartLab manufactured by Rigaku Corporation under the following conditions, and an X-ray diffraction profile in the equatorial direction of the peak corresponding to the (110) plane was obtained. ·X-ray source: CuKα ray Detector: Semiconductor 2D detector PILATUS 100K Beam size: 2mm wide x 0.1mm long Camera length: 150mm The crystallite size is calculated from the half-width βe (°) of the obtained peak using the following formula (Scherrer's formula). Crystallite size L (nm) = 0.9λ / (βe × cosθ) In the formula, λ represents the wavelength of the incident X-ray, and θ represents the Bragg angle (°) of the peak top. (4) Fiber diameter Using a digital micrometer manufactured by MITUTOYO, the diameter of the monofilament was measured at five random points along its length, and the average value was calculated. (5) Tensile strength and elongation Measurements were made in accordance with JIS L 1013 (2010 edition). Specifically, a skein of sample was left to stand for 24 hours in an atmosphere of 20°C and 65% RT humidity, and then three samples were measured using a Tensilon RTM500 tensile tester manufactured by Orientec Co., Ltd., with a test length of 250 mm and a tensile speed of 300 mm / min, and the average value was calculated. (6) Abrasion resistance Six scraping rods, each consisting of a 10 mm square stainless steel rod (with a corner radius of 0.1-0.3 mm and a mirror finish of #400) were attached parallel and equidistantly to the periphery of a 130 mm diameter, 240 mm long rotating frame. A 400 mm long monofilament was attached to the rotating frame at a load of 30 MPa on one end, and its other end was connected to a slide shaft. The sample was then suspended from the rotating frame so that it was in contact with the corners of the six scraping rods. Next, while showering water onto the fishing line, the slide shaft traversed the fishing line, giving it a 20 mm reciprocating motion at a speed of 60 seconds per stroke. The rotating frame was rotated at 1200 rpm in the direction of the weight. The monofilament was evaluated for breakage one minute after the start of rotation. A pass rating of 0 was given. ◯: The monofilament did not break when rubbed. ×: The monofilament broke when rubbed. (7) Curling tendency The produced monofilament, 1.0 m long (L1), was wound around a spool with an outer diameter of 66 mm and left in a thermostatic chamber at 60°C for 120 hours for heat treatment. The curling tendency was then calculated using the following formula based on the length of the monofilament before heat treatment (L1) and the length (L2) of the monofilament when it was pulled out 1 m from the spool after heat treatment and allowed to hang down naturally vertically: Curling tendency (%) = (L2 / L1) × 100. The higher the value of the curling tendency, the less likely the monofilament is to develop a curl. (8) Actual use evaluation Ten experienced anglers evaluated the line using it in practice, rating it on the following three-point scale, and the rank that received the most votes was used as the rating. The pass level is XX. ○○: Flexible and easy to tie. ○: It was hard to tie, but it was possible to tie it. ×: It was hard to tie and difficult to tighten, and was not suitable for fishing.

[0039] [Example 1] After melting vinylidene fluoride homopolymer at 260°C, it was melt-spun through a nozzle with a hole diameter of 2 mm, passed through a temperature-retaining region below the nozzle at 300°C, and then introduced into a cooling bath at 20°C. After that, the maximum tension was 110 N / mm 2 The stretching time was 45 seconds, and the total stretching ratio was 6.1. The stretching time was then 45 seconds ...

[0040] [Example 2] Maximum tension is 130N / mm 2 A monofilament was obtained in the same manner as in Example 1, except that the stretching time was 95 seconds.

[0041] [Example 3] Maximum tension is 60N / mm 2 A monofilament was obtained in the same manner as in Example 1, except that the stretching time was 45 seconds.

[0042] [Comparative Example 1] Maximum tension is 200N / mm 2 A monofilament was obtained in the same manner as in Example 1, except that the stretching time was 15 seconds.

[0043] Comparative Example 2 Maximum tension is 180N / mm 2 A monofilament was obtained in the same manner as in Example 1, except that the stretching time was 45 seconds.

[0044] Comparative Example 3 Maximum tension is 30N / mm 2 A monofilament was obtained in the same manner as in Example 1, except that the stretching time was 45 seconds.

[0045] [Table 1]

[0046] The monofilaments of Examples 1 to 3 all had high tensile strength, abrasion resistance, and tendency to curl, and were flexible and easy to use in actual use.

[0047] On the other hand, in the monofilament of Comparative Example 1, the crystallinity of the resin component contained in the monofilament was less than 40% and the Raman peak intensity ratio exceeded 12, resulting in a monofilament with poor abrasion resistance and prone to curling.

[0048] Furthermore, the resin component contained in the monofilament of Comparative Example 2 had a Raman peak intensity ratio of more than 12, and therefore the monofilament was prone to curling and was difficult to knot tightly in actual use.

[0049] Moreover, the resin component contained in the monofilament of Comparative Example 3 had a Raman peak intensity ratio of less than 5, resulting in a monofilament with low tensile strength and poor abrasion resistance. [Industrial Applicability]

[0050] As described above, the present invention makes it possible to obtain a monofilament that is flexible, easy to tie, and resistant to kink while still having high tensile strength and abrasion resistance equivalent to those of conventional monofilaments made of fluororesin. Therefore, it can be used particularly for fishing lines used as lure lines and fishing leaders. [Explanation of symbols]

[0051] 1 monofilament 2 Scraping rod 3 Load

Claims

1. A monofilament containing a fluororesin as a main component, wherein the resin component contained in the monofilament has a crystallinity of 40% or more and 70% or less, and a Raman peak intensity ratio expressed by formula (1) in a Raman spectrum of 5 or more and 12 or less. [Equation 1]

2. 2. The monofilament according to claim 1, wherein the crystallite size of the resin component contained in the monofilament is 6 nm or more and 15 nm or less.

3. 3. The monofilament according to claim 1, wherein the fluororesin is a vinylidene fluoride homopolymer.

4. A fishing line made from the monofilament according to claim 1 or 2.

5. A fishing line made from the monofilament according to claim 3.

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