Fishing line manufacturing method, fishing line and fishing line evaluation method

Abstract

To provide a fishing line that can be expected to produce good results for catching a variety of fish species. In a method for producing a fishing line by spinning a forming material containing a colorant and a resin component, the spectral transmittance of the fishing line in the wavelength range of 425 nm to 575 nm is within the range of 13% to 40%, and the spectral transmittance L0Z at a wavelength of 525 nm is 25.1X -0.23 >L0Z>12.9X -0.38 (where X represents the diameter of the fishing line (mm)).

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a fishing line. [Background technology]

[0002] Fish that are the target of fishing (hereinafter referred to as target fish) can be broadly divided into saltwater fish and freshwater fish, with many saltwater fish being particularly wary. Catching wary fish is a major attraction for anglers. In order to increase catches, it is important that the fishing line is not recognized by the fish. Therefore, it is desirable to use as thin a fishing line as possible so as not to warn the fish, but if the fishing line is too thin, there is a high probability that the line will break when a large fish gets caught on the hook. Therefore, a fishing line that is difficult for fish to recognize is desired. Patent Document 1 discloses a colored fishing line for saltwater fishing that has a maximum absorption value in the wavelength range of 500 to 600 nm in the visible light absorption spectrum. Patent Document 1 states that this fishing line is difficult for black porgy and red sea bream to recognize, and can be used effectively for these fish species. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-52287 A Summary of the Invention

[0004] However, while the fishing line of Patent Document 1 may be effective when the target fish is black porgy or red sea bream, it cannot be said to be effective for other target fish. [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a method for manufacturing a fishing line that can be expected to produce good results for catching a variety of fish species. [Means for solving the problem]

[0006] In one aspect, a method for making a fishing line is provided. The manufacturing method is a method for manufacturing a fishing line by spinning a forming material containing a colorant and a resin component, in which the spectral transmittance of the fishing line in the wavelength range of 425 nm to 575 nm is within a range of 13% to 40%, and the spectral transmittance L0Z at a wavelength of 525 nm is 25.1X -0.23 > L0Z > 12.9X -0.38 (where X represents the diameter (mm) of the fishing line). Preferably, the resin component contains polyvinylidene fluoride.

[0007] In another aspect, a fishing line is provided. The fishing line includes a colorant and a resin component, The spectral transmittance in the wavelength range of 425 nm to 575 nm is 13% to 40%, The spectral transmittance L0Z at a wavelength of 525 nm is 25.1X -0.23 > L0Z > 12.9X -0.38 (where X represents the diameter of the fishing line (mm)).

[0008] In another aspect, a method for evaluating a fishing line is provided. The evaluation method involves measuring the spectral transmittance and diameter of the fishing line, and determining whether the spectral transmittance in the wavelength range of 425 nm to 575 nm is 13% to 40%, and whether the spectral transmittance L0Z at a wavelength of 525 nm is 25.1X or lower. -0.23 > L0Z > 12.9X -0.38 (where X represents the diameter of the fishing line (mm)) is satisfied. Effect of the Invention

[0009] By using the fishing line of the present invention, good results can be obtained for various fish species, particularly various saltwater fish. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a front view of a fishing line with both ends omitted. [Diagram 2] FIG. 2 is an enlarged cross-sectional view taken along line II-II in FIG. [Diagram 3] A reference graph showing the light sensitivity of marine fish to each wavelength. [Figure 4] FIG. 13 is a front view illustrating a state in which a fishing line is wound around a glass plate, for explaining a method for measuring the reflectance of the fishing line. [Diagram 5] FIG. 13 is a reference diagram for explaining a method for measuring the reflectance of a fishing line, showing a glass plate with a fishing line wound around it placed in an integrating sphere. [Figure 6] 2 is a graph showing the spectral reflectance L1, the spectral reflectance L2, and the spectral transmittance L0 of the fishing line of Example 1. [Figure 7] FIG. 11 is a graph showing the spectral reflectance L1, the spectral reflectance L2, and the spectral transmittance L0 of the fishing line of Example 4. [Figure 8] FIG. 2 is a graph showing the spectral reflectance L2 and the spectral transmittance L0 of the fishing lines of Examples 2 and 3. [Figure 9] FIG. 1 is a graph showing the spectral reflectance L2 and the spectral transmittance L0 of the fishing lines of Examples 5 to 8. [Figure 10] FIG. 13 is a graph showing the spectral reflectance L2 and the spectral transmittance L0 of the fishing lines of Examples 9 to 12. [Figure 11] FIG. 2 is a graph showing the spectral reflectance L2 and the spectral transmittance L0 of the fishing lines of Examples 13 to 16. [Figure 12] FIG. 2 is a graph showing the spectral reflectance L2 and the spectral transmittance L0 of the fishing lines of Examples 17 to 20. [Figure 13] FIG. 2 is a graph showing the spectral reflectance L2 and the spectral transmittance L0 of the fishing lines of Examples 21 to 24. [Figure 14] FIG. 13 is a graph showing the spectral transmittance L0 of the fishing lines of Comparative Examples 5 to 10. [Figure 15] FIG. 13 is a graph showing the spectral transmittance L0 of the fishing lines of Comparative Examples 11 to 16. [Figure 16] FIG. 2 is a graph showing the relationship between the diameter of fishing lines and the spectral transmittance at a wavelength of 525 nm in the examples and comparative examples. [Figure 17] The graph in FIG. 16 shows the boundary between the embodiment and the comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In this specification, a numerical range represented by "lower limit GG to upper limit HH" means a range from the lower limit GG to the upper limit HH. When a plurality of such numerical ranges are separately described, it is understood that any lower limit and any upper limit can be selected to set "any lower limit to any upper limit."

[0012] [Fishing line composition] In terms of the line configuration, the fishing line of the present invention may be a monofilament, or a so-called braided line made by braiding a multifilament consisting of a plurality of thin monofilaments, or a fused line made by fusing a plurality of thin monofilaments to form a single line. From the viewpoint of excellent durability, a monofilament is preferable.

[0013] 1 and 2, the fishing line 1 of the present invention is a long and thin thread, and in terms of cross-sectional shape, is usually approximately circular in cross section. In terms of size, the diameter of the fishing line 1 is, for example, 0.1 mm to 2.5 mm.

[0014] In terms of composition, the fishing line includes a resin component, a colorant, and may include any suitable additives, such as light stabilizers, UV absorbers, antioxidants, crystallization inhibitors, plasticizers, etc. The resin component is not particularly limited, and examples thereof include vinylidene-based resins such as polyvinylidene fluoride, olefin-based resins such as high molecular weight polyethylene, polyamide-based resins, polyester-based resins, etc. Fishing lines containing vinylidene-based resins such as polyvinylidene fluoride are preferred because they have high strength, excellent abrasion resistance, weather resistance, and low water absorption, and have a refractive index close to that of water. The colorant is not particularly limited as long as it satisfies the spectral transmittance in the wavelength range. Representative examples of the colorant include pigments such as inorganic pigments and organic pigments, and dyes. These can be used alone or in combination of two or more. Examples of the inorganic pigments include iron oxide, red iron oxide, alkali blue, lysol red, carmine 6B, disazo yellow, phthalocyanine blue, quinacridone red, and isoindoline yellow. Examples of the organic pigments include anthraquinone-based, azo-based, and perylene-based pigments. Examples of the dyes include auramine, fuchsine, methylene blue, malachite green, crystal violet, and cationic dyes.

[0015] It is preferable to use a pigment as the colorant because it is possible to form a fishing line with excellent dye absorption and high fastness. Furthermore, among pigments, it is more preferable to use an organic pigment because it is less likely to cause thread breakage during the production of the fishing line. The content of the coloring agent is appropriately set. In terms of the relationship between the content of the coloring agent and the diameter of the fishing line, a fishing line in which the content of the coloring agent Y0 satisfies the following formula (1) is preferred. In particular, a fishing line containing an organic pigment as a coloring agent and a polyvinylidene fluoride resin as a resin component preferably satisfies the following formula (1). A fishing line that satisfies the following formula (1) improves the catch rate for many species of saltwater fish and freshwater fish. Specifically, according to the research of the present inventors, if the content of the coloring agent Y0 is Y2 or less, the catch rate may be the same as that of an uncolored fishing line. If the content of the coloring agent Y0 is Y1 or more, the bite frequency of fish (both saltwater fish and freshwater fish) may be worse than that of an uncolored fishing line. It is presumed that there is an interaction between the above-mentioned range of spectral transmittance and the content of the coloring agent with respect to the catch rate. Formula (1): Y2 <Y0<Y1 Formula (2): Y1=58.6X -0.65 Formula (3): Y2=8.9X -1.46 Here, X represents the diameter of the fishing line (mm), Y0 represents the colorant content (ppm), Y1 represents the upper limit of the colorant content (ppm), and Y2 represents the lower limit of the colorant content (ppm). The above formula (1) represents the relationship between the line diameter and the colorant content of a fishing line that satisfies the following formula (4). Specifically, formula (2) can be calculated by taking the colorant content on the vertical axis and the line diameter on the horizontal axis, applying the least squares method and power approximation using the colorant content of each line diameter of a fishing line that satisfies the upper limit of formula (4) as data. Formula (3) can be calculated by taking the colorant content on the vertical axis and the line diameter on the horizontal axis, applying the least squares method and power approximation using the colorant content of each line diameter of a fishing line that satisfies the lower limit of formula (4) as data.

[0016] The optical properties of the fishing line are: spectral transmittance in the wavelength range of 425nm to 575nm is 13% to 40%, and the spectral transmittance L0Z at a wavelength of 525nm is 25.1X -0.23 > L0Z > 12.9X -0.38 (where X represents the diameter (mm) of the fishing line) is satisfied. Formula (4): 25.1X -0.23 > L0Z > 12.9X -0.38 In equation (4), L0Z represents the spectral transmittance of the fishing line at a wavelength of 525 nm, and X represents the diameter of the fishing line (mm). A fishing line that satisfies the relationship of formula (4) above can be expected to produce good results in catching a variety of fish species, particularly a variety of saltwater fish.

[0017] A spectral transmittance of 13% to 40% in the wavelength range of 425 nm to 575 nm means that the spectral transmittance in the entire wavelength range of 425 nm to 575 nm is within the range of 13% to 40%. The fishing line preferably has a spectral transmittance of 14% to 38% in the wavelength range of 425 nm to 575 nm, and more preferably 17% to 37%. Furthermore, it is preferable that the difference (maximum value - minimum value) between the maximum value of the spectral transmittance in the wavelength range of 425nm to 575nm of the fishing line and the minimum value of the spectral transmittance in the wavelength range of 425nm to 575nm is within 13%, and furthermore, it is more preferable that the difference (maximum value - minimum value) is 6% to 12%, and even more preferably 8% to 11%.

[0018] Furthermore, the fishing line has a spectral transmittance in the wavelength range of 575 nm to 700 nm (however, since 575 nm overlaps with the wavelength range of 425 nm to 575 nm, here it means a wavelength of 700 nm, which is greater than 575 nm) of, for example, 18% or more, and preferably 20% or more. The spectral transmittance of the fishing line can be measured by the "Method of measuring spectral transmittance L0" described in the Examples below. That is, the sum of the reflectance of light reflected by the fishing line and the reflectance of light transmitted through the fishing line and reflected (spectral reflectance L1) is measured, the reflectance of light reflected by the fishing line (spectral reflectance L2) is measured, and the spectral reflectance L2 is subtracted from the spectral reflectance L1, thereby determining the spectral transmittance L0 of the fishing line.

[0019] The fishing line has a spectral reflectance in the wavelength range of 425 nm to 700 nm of, for example, 26% or less, preferably a spectral reflectance in the wavelength range of 425 nm to 700 nm of 21% or less, and more preferably a spectral reflectance in the wavelength range of 425 nm to 700 nm of 12% to 21%. Furthermore, the fishing line has a difference (maximum value - minimum value) between the maximum value of the spectral reflectance in the wavelength range of 425 nm to 700 nm and the minimum value of the spectral reflectance in the wavelength range of 425 nm to 700 nm, which is, for example, within 9%, and it is further preferable that the difference (maximum value - minimum value) is 4% to 8%. Furthermore, the fishing line of the present invention has a spectral reflectance in the wavelength range of 425 nm to 575 nm of, for example, 20% or less, and preferably has a spectral reflectance in the wavelength range of 425 nm to 575 nm of 10% to 20%. The spectral reflectance of the fishing line refers to the reflectance of only the light that hits the fishing line and is reflected. The spectral reflectance L2 of the fishing line can be measured by the <Measurement of Spectral Reflectance L2> described in the Examples below.

[0020] By using the fishing line of the present invention, it is possible to catch a relatively large number of fish of various kinds. This is also evident from the "Actual Fishing Test" in the following examples. The reason why such a good catch can be expected is not clear, but the inventors presume it as follows.

[0021] A relatively recent research paper, "Habitats and Color Vision of Fish" (Received June 10, 2021, Edited by Takahashi Kyoichi, Hiroshima Shudo University Research Papers, pp. 31-76), presents wavelength sensitivity data for 54 species of marine fish. A bar graph of the wavelength sensitivity data from that paper is quoted in Figure 3. It is described here that, of the 54 species of marine fish, only five species have photosensitivity in the red region, and most marine fish have photosensitivity in the wavelength regions of 420nm to 480nm (blue region) and 500nm to 580nm (green region). In particular, it can be seen that marine fish are highly sensitive to light of 520nm.

[0022] When light of various colors (wavelengths) hits a fishing line, some colors pass through the line, other colors are absorbed by the line, and some of the light is reflected. Fish visually perceive the mixture of light that passes through the line and light that is reflected by the line, and recognize the colors of light that they perceive as the color and brightness of the fishing line. Fish that are the subject of fishing include fish that can distinguish colors and fish that cannot distinguish colors. Examples of fish that can distinguish colors include sea bass, flounder, black sea bream, flounder, and sweetfish. Examples of fish that cannot distinguish colors include cod, conger eel, alfonsino, and lizardfish. In addition, fish that live in the deep sea where light does not reach are often unable to distinguish colors. In the strict sense, mollusks such as octopus, bigfin reef squid, and cuttlefish cannot be called fish, but in this specification, such mollusks are also the subject of fishing and are included in the subject fish. These fish recognize the presence of a fishing line by recognizing color and light and dark. In particular, fish can sense the presence of a transparent fishing line by recognizing light and dark. In the present invention, it can be said that it has been discovered that a fishing line with a specific range of spectral transmittance in a specified wavelength range and a specific relationship between the line diameter and the spectral transmittance makes it difficult for fish to recognize the presence of the fishing line, thereby improving catches.

[0023] As described above, a fishing line with a spectral transmittance of 13% to 40% in the wavelength range of 425 nm to 575 nm transmits a small amount of light in that wavelength range. Since light in that wavelength range (fish that can distinguish colors have relatively high photosensitivity in the wavelength range of 425 nm to 575 nm) is difficult to transmit through the fishing line, it is difficult for various fish species that can distinguish colors to recognize the fishing line. As a result, it is estimated that good catches can be expected for fish that can distinguish colors. In particular, a fishing line with a difference between the maximum and minimum values ​​of the spectral transmittance in the wavelength range of 425 nm to 575 nm (maximum value - minimum value) of 13% or less is considered to be effective for various fish species because the amount of light transmitted in that wavelength range does not change significantly. Furthermore, in the case of a fishing line with a spectral reflectance of 26% or less in the wavelength range of 425 nm to 700 nm, the amount of light reflected by the fishing line is small. Therefore, it is considered that the light reflected by the fishing line makes it difficult for fish to recognize the fishing line. In particular, a fishing line with a difference between the maximum and minimum values ​​of the spectral reflectance (maximum value - minimum value) in the wavelength range of 425 nm to 700 nm is 9% or less reflects the same amount of light in almost the entire visible light range. Therefore, the light reflected by the fishing line becomes almost white light, making it difficult for fish to distinguish between the fishing line and the water area around the fishing line (there is a difference in brightness between the fishing line and the surrounding water area, but in water where light does not easily reach, it is difficult to distinguish between the fishing line and the surrounding water area based on the difference in brightness). Therefore, it is considered that the fishing line becomes difficult to recognize due to the reflected light. As a result, it is estimated that good catches of various fish species can be expected.

[0024] In addition, it has been said that, generally speaking, the smaller the diameter of a fishing line, the better the catch. The inventors of the present invention have deduced that the diameter of a fishing line is not the only factor that determines the quality of a catch, and that the spectral transmittance of the fishing line is also an important factor, and have repeated trial and error. As a result, they have found that the spectral transmittance L0Z of a fishing line at a wavelength of 525 nm is expressed by the formula (4): 25.1X -0.23 > L0Z > 12.9X -0.38 It was found that by satisfying the above relationship, good catches of various fish species can be expected. This is a fact discovered for the first time by the present inventors. The reason why the spectral transmittance is based on light with a wavelength of 525 nm is because, as mentioned above, saltwater fish have a high sensitivity to light with a wavelength of 520 nm.

[0025] [Fishing line manufacturing method] The fishing line can be produced by spinning a material containing a colorant and a resin component. The spinning process includes at least one step selected from the following steps (a) to (e): (a) A step of melt spinning a forming material containing a resin component. (b) A step of solution spinning a liquid forming material containing a resin component. (c) A step of further drawing the yarn obtained by spinning (for example, the above-mentioned melt spinning or solution spinning) a forming material containing a resin component. (d) A process of spinning (for example, the melt spinning or solution spinning) a forming material containing a resin component, braiding a plurality of the obtained threads into a braided thread, or fusing a plurality of the threads into a fused thread. (e) A step of applying an oil, dye, or the like to one or more threads obtained by spinning (for example, the above-mentioned melt spinning or solution spinning) a forming material containing a resin component.

[0026] In the fishing line manufacturing method of the present invention, the spectral transmittance in the wavelength range of 425 nm to 575 nm is within the range of 13% to 40%, and the spectral transmittance L0Z at a wavelength of 525 nm is 25.1X -0.23 > L0Z > 12.9X-0.38 The fishing line is manufactured so as to satisfy the above. Since the main factor affecting the optical properties of a fishing line is the colorant, the colorant should be selected based on the following criteria: As mentioned above, pigments and dyes can be used as colorants, but it is preferable to use pigments, and more preferable to use organic pigments, because it is possible to construct fishing lines with high fastness. Representative examples of red organic pigments include naphthol AS azo pigments and perylene azo pigments. Representative examples of yellow organic pigments include pyrazolone azo pigments. Representative examples of blue organic pigments include anthraquinone azo pigments, phthalocyanine condensed polycyclic pigments, and indigo condensed polycyclic pigments. Representative examples of orange pigments include perinone condensed polycyclic pigments, and representative examples of purple organic pigments include quinacridone condensed polycyclic pigments. Generally, red organic pigments have a sharp absorption peak at a wavelength of about 520 nm, yellow organic pigments have a sharp absorption peak at a wavelength of about 450 nm, and blue organic pigments have a sharp absorption peak at a wavelength of about 580 nm. A simple method for producing a fishing line that satisfies the above optical properties is to use two or more organic pigments, preferably at least two of the three primary colors of red, yellow and blue pigments. For example, when the total weight of the colorant is 100%, it is preferable to use a colorant that contains 35-55% by weight of a red organic pigment, 20-40% by weight of a yellow organic pigment and 15-35% by weight of a blue organic pigment, and more preferably to use a colorant that contains 40-50% by weight of a red organic pigment, 25-35% by weight of a yellow organic pigment and 20-30% by weight of a blue organic pigment.

[0027] The amount of colorant added is appropriately set. In order to obtain a fishing line that satisfies the optical properties, it is preferable to set the amount of colorant added as follows in relation to the line diameter of the fishing line. For example, when manufacturing a fishing line with a line diameter (diameter) of less than 0.2 mm, 100 to 250 ppm, preferably 160 to 220 ppm of colorant is added to the entire material forming the fishing line. When manufacturing a fishing line with a line diameter of 0.2 mm or more and less than 0.3 mm, 60 to 150 ppm, preferably 80 to 120 ppm of colorant is added. When manufacturing a fishing line with a line diameter of 0.3 mm or more and less than 0.5 mm, 40 to 90 ppm, preferably 50 to 80 ppm of colorant is added. When manufacturing a fishing line with a line diameter of 0.5 mm or more and less than 1.2 mm, 20 to 65 ppm, preferably 30 to 60 ppm of colorant is added. When manufacturing a fishing line with a line diameter of 1.2 mm or more and less than 1.6 mm, 5 to 45 ppm of colorant is added, preferably 10 to 40 ppm.When manufacturing a fishing line with a line diameter of 1.6 mm or more and less than 2.5 mm, 3 to 25 ppm of colorant is added, preferably 5 to 20 ppm.

[0028] As the resin component, as described above, vinylidene-based resins such as polyvinylidene fluoride, olefin-based resins such as high molecular weight polyethylene, polyamide-based resins, polyester-based resins, and the like can be used. As the additives, as described above, light resistance agents, ultraviolet absorbers, antioxidants, crystallization inhibitors, plasticizers, etc. can be used. For example, a fishing line made of a polyvinylidene fluoride resin monofilament is produced by melt spinning as described above in (a) below. A resin composition (forming material) is prepared by mixing the polyvinylidene fluoride resin with the colorant and, if necessary, additives. The resin composition is, for example, filled in a hopper of an extruder-type spinning machine, and spun by melt extrusion from a die at a temperature of 220°C to 290°C, an extrusion pressure of 1 to 50 MPa, and a spinning speed of 0.3 m / min to 300 m / min. The monofilament spun from the extruder is cooled in a cooling bath. As the cooling bath, a liquid inactive to the polyvinylidene fluoride resin is used, such as glycerin, polyethylene glycol, water, or a mixture thereof. The monofilament after cooling is stretched and heat-set. The stretching treatment may be a one-stage stretching treatment, but is usually performed in a multi-stage stretching treatment. In addition, the heat treatment for stretching and heat setting is not particularly limited, and examples thereof include passing the filament through a dry heat space in a hot atmosphere such as an oven or hot air, or immersing the filament in a heat medium bath such as silicone oil. The total stretching ratio is, for example, 5 to 7 times.

[0029] [Fishing line evaluation method] In another aspect, the present invention provides a method for evaluating a fishing line, which comprises measuring the spectral transmittance and diameter of the fishing line, and determining whether the spectral transmittance in the wavelength range of 425 nm to 575 nm is within the range of 13% to 40%, and the spectral transmittance L0Z at a wavelength of 525 nm is within the range of 25.1X or more. -0.23 > L0Z > 12.9X -0.38 (where X represents the diameter (mm) of the fishing line). By using a fishing line that has been confirmed to satisfy the above relationship, good results can be expected for a variety of fish species. From another perspective, the present invention provides the following manufacturing method, for example, a step of producing a fishing line by spinning a forming material containing a colorant and a resin component, measuring the spectral transmittance and diameter of the obtained fishing line, and determining whether the spectral transmittance in the wavelength range of 425 nm to 575 nm is 13% to 40% and the spectral transmittance L0Z at a wavelength of 525 nm is 25.1X or more. -0.23 > L0Z > 12.9X -0.38The fishing lines are manufactured by carrying out an evaluation step to confirm that the relationship is satisfied, and a mass-production step to mass-produce the fishing lines that are confirmed to satisfy the relationship in the evaluation step. The mass production step refers to mass-producing identical fishing lines to produce a large number of products. EXAMPLES

[0030] The present invention will be further described below with reference to examples and comparative examples. Note that the present invention is not limited to the following examples.

[0031] [Colorants used] <Organic pigments (A1)> The organic pigment (A1) is a mixture of 30% by weight of an azo pigment naphthol AS type (CI Pigment Red 112), 20% by weight of an azo pigment pyrazolone type (CI Pigment Yellow 10), 18% by weight of a condensed polycyclic pigment phthalocyanine type (CI Pigment Blue 15), 2% by weight of carbon black as a dulling agent, and 30% by weight of magnesium stearate as a dispersing agent. <Dye-based color material (B1)> The dye-based colorant (B1) is a mixture of 84% by weight of a polymethine dye (CI Basic Red 12), 0.5% by weight of carbon black as a dulling agent, 0.5% by weight of magnesium stearate and 0.5% by weight of zinc stearate as dispersants, and 14.5% by weight of ethylene bisstearamide as a lubricant. <Dye (C1)> The dye (C1) is a dye solution (concentration: 2% by weight) in which a cationic dye (KAYACRYL RED GRL-ED: manufactured by Nippon Kayaku Co., Ltd.) is dissolved.

[0032] [Method of measuring spectral transmittance L0] As shown in Figure 4, the fishing line to be measured was wound tightly in a single layer around a glass slide for an optical microscope and fixed so that it would not come off. In the following, the glass slide with the fishing line wound in a single layer without any gaps is referred to as the "sample plate."

[0033] <Measurement of Spectral Reflectance L1> The sample plate was placed on the surface of a white background plate as shown in Fig. 5, fixed so as not to move, and set so that the fishing line was exposed from the window of a commercially available integrating sphere device. A commercially available spectrophotometer (product name "V-650" manufactured by JASCO Corporation) was used, and its light source (halogen lamp) and detector were arranged as shown in Fig. 5. Light was irradiated from the light source to the area of ​​the sample plate where the fishing lines were densely packed, and the reflected light was detected by the detector. The spectral reflectance L1 was measured from the intensity of the light from the light source and the intensity of the reflected light. The measurement wavelength was in the range of 400 nm to 750 nm, and the measurement was performed with a bandwidth of 5 nm and a pitch of 0.5 nm. The reflected light here consists of light reflected by the fishing line and light transmitted through the fishing line and reflected by the white background plate. Therefore, the spectral reflectance L1 is equal to the sum of the spectral reflectance of the light reflected by the fishing line and the spectral reflectance of the light transmitted through the fishing line and reflected.

[0034] <Measurement of spectral reflectance L2> The spectral reflectance L2 was measured in the same manner as in <Measurement of Spectral Reflectance L1> above, except that a black background plate was used instead of the white background plate. The reflected light here is the light reflected by the fishing line (because the light that passes through the fishing line is absorbed by the black background plate), and therefore the spectral reflectance L2 is equal to the spectral reflectance of the light reflected by the fishing line.

[0035] <Calculation of spectral transmittance L0> The spectral transmittance L0 of the fishing line was determined by subtracting the spectral reflectance L2 from the spectral reflectance L1. Spectral transmittance of fishing line L0=L1-L2

[0036] [How to measure the diameter of a fishing line] The diameter (mm) of the fishing line was measured using a micrometer manufactured by Mitutoyo Corp. The diameter was measured at five random points along the length of the fishing line, and the average value was used as the diameter (mm).

[0037] [Tensile strength at break and tensile elongation] In accordance with the provisions of JIS L 1013, the fishing lines were left in a temperature and humidity controlled room at 20°C and 65% RH for 24 hours, and then the tensile breaking strength and tensile elongation (tensile elongation is the elongation at break) were measured using a tensile tester (manufactured by Shimadzu Corporation under the trade name "Autograph S-500D") with a sample length of 300 mm and a tensile speed of 300 mm / min. The tensile breaking strength and tensile elongation were measured five times for each fishing line, and the average values ​​were used as the tensile breaking strength (N) and tensile elongation (%).

[0038] [Knot breaking strength] According to the provisions of JIS L 1013, the fishing line was knotted tightly with a square knot. This was used as the test subject, and after leaving it in a temperature and humidity controlled room for 24 hours in the same manner as in the above [Tensile breaking strength and tensile elongation], the knot breaking strength was measured using a tensile tester (Shimadzu Corporation, product name "Autograph S-500D"). The knot breaking strength was measured five times for each fishing line, and the average value was used as the knot breaking strength (N).

[0039] [Example 1] A polyvinylidene fluoride homopolymer chip containing 160 ppm of organic pigment (A1) was fed to a spinning machine, heated to 260°C to melt it, extruded from a die with a hole diameter of 0.6 mm, and cooled in a bath at 90°C to obtain an undrawn monofilament. The obtained undrawn monofilament was drawn 5.0 times in a heat medium bath at 160°C to obtain a one-stage drawn yarn. Subsequently, this one-stage drawn yarn was further drawn in a dry heat bath at 160°C to obtain a two-stage drawn yarn that was drawn 5.7 times in total from the undrawn yarn. Furthermore, this two-stage drawn yarn was heat-set while shrinking to 0.95 times in a dry heat bath at 160°C to produce a fishing line (colored polyvinylidene fluoride monofilament) with a diameter of 0.12 mm.

[0040] The spectral transmittance of the fishing line of Example 1 was measured. The results are shown in FIG. 6. As shown in FIG. 6, there were multiple peaks of the spectral transmittance L0 (the peaks are marked with arrows in FIG. 6). In addition, the maximum value (A) and minimum value (B) of the spectral transmittance L0 in the wavelength range of 425 nm to 575 nm, the difference (AB) between the maximum value and the minimum value, and the spectral transmittance L0Z at a wavelength of 525 nm are listed in Table 1. Furthermore, the maximum value (C) and minimum value (D) of the spectral transmittance L0 in the wavelength range of 575 nm to 700 nm, and the difference (CD) between the maximum value and the minimum value are listed in Table 1, and the maximum value (E) and minimum value (F) of the spectral reflectance L2 in the wavelength range of 425 nm to 700 nm, and the difference (EF) between the maximum value and the minimum value are listed in Table 1. Furthermore, the diameter, tensile breaking strength, tensile elongation, and knot breaking strength of the fishing line of Example 1 were measured. The results are shown in Table 1.

[0041] [Table 1]

[0042] [Table 2]

[0043] [Examples 2 to 24] The fishing lines of Examples 2 to 24 were produced in the same manner as in Example 1, except that at least one of the amount of organic pigment (A1), the hole diameter of the nozzle, and the draw ratio was changed as shown in Tables 1 and 2. Note that changing the hole diameter of the nozzle changes the diameter of the resulting fishing line.

[0044] The spectral transmittance was also measured for each of the fishing lines of Examples 2 to 24. The results of Example 4 are shown in Figure 7. As shown in Figure 7, there were multiple peaks in the spectral transmittance L0 (the peaks are marked with arrows in Figure 7). The measurement results of the spectral transmittance of each fishing line of Examples 2, 3, 5 to 24 are shown in Figures 8 to 13. Note that Figures 8 to 13 show the graphs of the spectral reflectance L2 and the spectral transmittance L0 of each fishing line of Examples 2, 3, 5 to 24. Note that, as described above, the spectral reflectance L2 is the reflectance consisting only of the light reflected from the fishing line. As shown in Figures 8 to 13, there were multiple peaks of the spectral transmittance L0. In addition, the maximum and minimum values ​​of the spectral transmittance L0 in the wavelength range of 425 nm to 575 nm, the difference (AB) between the maximum and minimum values, and the spectral transmittance L0Z at a wavelength of 525 nm are listed in Tables 1 and 2. Furthermore, the maximum (C) and minimum (D) values ​​of the spectral transmittance L0 in the wavelength range of 575 nm to 700 nm and the difference between the maximum and minimum values ​​(CD) for Examples 2 to 24, and the maximum (E) and minimum (F) values ​​of the spectral reflectance L2 in the wavelength range of 425 nm to 700 nm and the difference between the maximum and minimum values ​​(EF) are shown in Tables 1 and 2. Furthermore, the diameter, tensile breaking strength, tensile elongation and knot breaking strength of the fishing lines of Examples 2 to 24 were measured. The results are shown in Tables 1 and 2.

[0045] [Comparative Examples 1 to 4] Fishing lines of Comparative Examples 1 to 4 having a diameter of 0.12 mm were produced in the same manner as in Example 1, except that the amount of the organic pigment (A1) was changed.

[0046] [Comparative Example 5] A fishing line (colored polyvinylidene fluoride monofilament) of Comparative Example 5 having a diameter of 0.25 mm was prepared in the same manner as in Example 4, except that the organic pigment (A1) was not blended (see Table 3).

[0047] [Comparative Example 6] A fishing line (colored polyvinylidene fluoride monofilament) having a diameter of 0.25 mm of Comparative Example 6 was prepared in the same manner as in Example 4, except that the dye (C1) was used instead of the organic pigment (A1) (see Table 3). Specifically, a fishing line (uncolored polyvinylidene fluoride monofilament) with a diameter of 0.25 mm was prepared without blending organic pigment (A1) (colorant), and this fishing line was passed through a 3 m long bath filled with dye (C1) at a speed of 20 m / min, and then dried to prepare the fishing line of Comparative Example 6. The temperature of the dye (C1) in the bath (container) was set to 80°C.

[0048] [Comparative Example 7] A fishing line (colored polyvinylidene fluoride monofilament) of Comparative Example 7 having a diameter of 0.25 mm was prepared in the same manner as in Example 4, except that the amount of the organic pigment (A1) was changed (see Table 3).

[0049] [Comparative Example 8] A fishing line of Comparative Example 8 having a diameter of 0.4 mm was produced in the same manner as in Example 6, except that the organic pigment (A1) was not blended (see Table 3).

[0050] [Comparative Example 9] A fishing line of Comparative Example 9 having a diameter of 0.4 mm was produced in the same manner as in Example 6, except that a prescribed amount of dye-based color material (B1) was used instead of the organic pigment (A1) (see Table 3).

[0051] [Comparative Examples 10 and 11] Fishing lines of Comparative Examples 10 and 11 having a diameter of 0.4 mm were prepared in the same manner as in Example 6, except that the amount of the organic pigment (A1) was changed (see Table 3).

[0052] [Comparative Examples 12 to 14] Fishing lines of Comparative Examples 12 to 14 having a diameter of 0.44 mm were prepared in the same manner as in Example 9, except that no organic pigment (A1) was used, or a specified amount of dye-based colorant (B1) was used instead of the organic pigment (A1), or the amount of organic pigment (A1) was changed (see Table 4).

[0053] [Comparative Example 15] A fishing line of Comparative Example 15 having a diameter of 0.72 mm was produced in the same manner as in Example 11, except that the organic pigment (A1) was not blended (see Table 4).

[0054] [Comparative Examples 16 to 21] Fishing lines of Comparative Examples 16 to 21 with a diameter of 1.02 mm were prepared in the same manner as in Example 12, except that the organic pigment (A1) was not added, the amount of the organic pigment (A1) was changed, or the draw ratio was changed (see Table 4).

[0055] [Comparative Examples 22 to 25] Fishing lines of Comparative Examples 22 to 25 having a diameter of 1.54 mm were prepared in the same manner as in Example 17, except that the organic pigment (A1) was not used or the amount of the organic pigment (A1) was changed (see Table 5).

[0056] [Comparative Examples 26 to 29] Fishing lines of Comparative Examples 26 to 29 having a diameter of 2.1 mm were prepared in the same manner as in Example 21, except that the organic pigment (A1) was not used or the amount of the organic pigment (A1) was changed (see Table 5).

[0057] The spectral transmittance was also measured for each of the fishing lines of Comparative Examples 1 to 29. Graphs of the spectral transmittance L0 of each of the fishing lines of Comparative Examples 5 to 16 are shown in Figures 14 and 15. Note that graphs for Comparative Examples 1 to 4 and 17 to 29 have been omitted. Tables 3 to 5 also show the maximum and minimum values ​​of the spectral transmittance L0 in the wavelength range of 425 nm to 575 nm, the difference (AB) between the maximum and minimum values, and the spectral transmittance L0Z at a wavelength of 525 nm. Furthermore, the diameter, tensile breaking strength, tensile elongation and knot breaking strength of the fishing lines of Comparative Examples 1 to 29 were measured. The results are shown in Tables 3 to 5.

[0058] [Table 3]

[0059] [Table 4]

[0060] [Table 5]

[0061] [Actual fishing test] Using the fishing lines of the Examples and Comparative Examples, actual sea fishing was carried out and the catches were evaluated.

[0062] <Test (1)> On April 17, 2023, tip run fishing was conducted from a boat off the coast of Imari City, Saga Prefecture. The anglers were four testers, and the time was two hours from 6:00 a.m. to 8:00 a.m. A tester is a professional angler who tests fishing equipment, and is also called a field tester (hereinafter the same). Tip run fishing is a fishing method that mainly targets bigfin reef squids lurking on the seabed, using a rig in which a shock leader is tied several meters to the end of a fishing line and a tip run lure is tied to the end of the shock leader.

[0063] In this test (1), an ultra-high molecular weight polyethylene line with a diameter of 0.13 mm was used as the lead line, and the length of the shock leader was 2 m. Two testers used the fishing line of Example 4 as the shock leader, and the remaining two testers used the fishing line of Comparative Example 5 (diameter 0.25 mm) as the shock leader. The reason why the fishing line of Example 4 and the fishing line of Comparative Example 5 were selected is because they have the same diameter (0.25 mm). If fishing lines with different diameters are used, there is a risk that the fishing results will change due to the difference in diameter, so the Example and Comparative Example with the same diameter were selected. The catch is shown in Table 6.

[0064] [Table 6]

[0065] As shown in Table 6, when the fishing line of Example 4 was used, the catch was better than when the fishing line of Comparative Example 5 was used. According to a literature (Nippon Suisan Gakkaishi 80(2),245(2014)), the maximum absorption wavelength of the bigfin reef squid is 494 nm, and although bigfin reef squids do not have color vision, they are presumed to be able to sense light in the absorption wavelength range of rhodopsin. The fishing line of Example 4 is less susceptible to light with wavelengths of 425 nm to 575 nm than the fishing line of Comparative Example 5. The inventors presume that the fishing line of Example 4 is therefore less susceptible to light than the fishing line of Comparative Example 5, suppressing the wariness of the bigfin reef squid and improving the catch.

[0066] <Test (2)> On April 17, 2023, red snapper fishing was conducted from a boat off the coast of Imari City, Saga Prefecture. The anglers were three testers, and the time was eight hours from 8:00 a.m. to 4:00 p.m. Tai rubber fishing is a fishing method that mainly targets sea bream and various other fish species by tying a shock leader of several meters to the end of the main line, and then tying a tackle consisting of four parts - a weight, a thin strip of film, a thin string, and a fishing hook - to the end of the shock leader (same below). In this test (2), an ultra-high molecular weight polyethylene line with a diameter of 0.15 mm was used as the fishing line, and the shock leader was 3 m long. One tester used the fishing line of Example 7 (diameter 0.40 mm) as the shock leader, and the remaining two testers used the fishing line of Comparative Example 8 (diameter 0.40 mm) as the shock leader. The reason for choosing the fishing line of Example 7 and the fishing line of Comparative Example 8 is that they have the same diameter (0.40 mm). The catch is shown in Table 7.

[0067] [Table 7]

[0068] As shown in Table 7, when the fishing line of Example 7 was used, a wider variety of fish species were caught and the number of catches was greater than when the fishing line of Comparative Example 8 was used.

[0069] <Test (3)> On April 28, 2023, red snapper fishing was conducted from a boat off the coast of Imari City, Saga Prefecture. The anglers were six testers, and the time was 10 hours from 6:00 a.m. to 4:00 p.m.

[0070] In this test (3), an ultra-high molecular weight polyethylene line with a diameter of 0.15 mm was used as the line, and the length of the shock leader was 3 m. Two testers used the fishing line of Example 8 (diameter 0.40 mm) as the shock leader, two testers used the fishing line of Comparative Example 8 (diameter 0.40 mm) as the shock leader, and the remaining two testers used the fishing line of Comparative Example 9 (diameter 0.40 mm) as the shock leader. In addition, on the boat, each angler was positioned so that anglers using the same shock leader were not next to each other. The reason why the fishing line of Example 8 and the fishing lines of Comparative Examples 8 and 9 were selected is because they have the same diameter (0.40 mm). The catch is shown in Table 8.

[0071] [Table 8]

[0072] As shown in Table 8, when the fishing line of Example 8 was used, a wider variety of fish species were caught and the number of catches was greater than when the fishing lines of Comparative Examples 8 and 9 were used.

[0073] <Test (4)> On May 16, 2023, we went to the reef off the coast of Ikitsuki, Hirado City, Nagasaki Prefecture, and conducted a tsuri fishing trip. The anglers were four testers, and the time was eight hours from 6:00 a.m. to 2:00 p.m. Fukase fishing is a fishing method in which a float is attached to a line, the line is extended from the float to a length equivalent to the depth of the water where the fish is to be caught, a leader line is tied to the end of the line for about 2 to 3 meters, a fishing hook is tied to the end of the leader line, and bait such as krill is attached to the fishing hook. In the Fukase fishing, the fish bite that appears on the float is identified, and the fish is hooked by an action called "awase".

[0074] In this test (4), the target fish was set to be the black porgy, a nylon line with a diameter of 0.23 mm was used as the line, and the length of the line was set to 3 m. The following fishing rods were prepared: (a) a fishing rod using the fishing line of Example 4 as the line, (b) a fishing rod using the fishing line of Comparative Example 5 as the line, (c) a fishing rod using the fishing line of Comparative Example 6 as the line, and (d) a fishing rod using the fishing line of Comparative Example 7 as the line. The four testers fished by switching between fishing rods (a) to (d) in turn every hour (for example, from 6:00 to 7:00 a.m., the first tester fished with rod (a), the second tester with rod (b), the third tester with rod (c), and the fourth tester with rod (d). From 7:00 to 8:00 a.m., the first tester fished with rod (d), the second tester with rod (a), the third tester with rod (b), and the fourth tester with rod (c). ...). In addition, the testers were moved from one place to another so that the same tester was not fixed to one place (fishing seat). The fishing line of Example 4 and the fishing lines of Comparative Examples 5 to 7 were selected because they had the same diameter (0.25 mm).

[0075] Table 9 shows the number of black porgy caught and the number of fish other than black porgy caught when using the fishing lines of the examples and the comparative examples. The fish other than black porgy were grunt, small red sea bream, and rockfish. In the fishing line rating column of Table 9, "◎" indicates a fishing line that achieved the highest number of catches, "○" indicates a fishing line that achieved 75% or more of the highest number of catches, "△" indicates a fishing line that achieved 50% to 75% of the highest number of catches, and "×" indicates a fishing line that achieved less than 50% of the highest number of catches (the same applies to each table below).

[0076] [Table 9]

[0077] <Test (5)> On May 11, 2023, we conducted a Bachikon Ajing from a boat off the coast of Imari City, Saga Prefecture. There were five testers who fished for five hours from 6:00 pm to 11:00 pm. Bachikon ajing is a fishing method that involves tying several metres of line to the end of a main line, attaching a weight to the end of the line, tying a 5-30cm long branch line to the line a few tens of centimetres above the weight, attaching a jig head weighing a few grams to the end of the branch line, and attaching earthworms or artificial bait (such as plastic worms) to the jig head, and mainly targeting horse mackerel and a variety of other fish species.

[0078] In this test (5), an ultra-high molecular weight polyethylene line with a diameter of 0.15 mm was used as the main line, the length of the line was 2 m, and the length of the branch line was 20 cm. The following fishing rods were prepared: (e) a fishing rod using the fishing line of Example 4 as the line and branch line, (f) a fishing rod using the fishing line of Example 5 as the line and branch line, (g) a fishing rod using the fishing line of Comparative Example 5 as the line and branch line, (h) a fishing rod using the fishing line of Comparative Example 6 as the line and branch line, and (i) a fishing rod using the fishing line of Comparative Example 7 as the line and branch line. As in test (4), five testers fished by switching between fishing rods (e) to (i) in turn every hour. In addition, each tester was moved from one place to another so that the same tester was not fixed to one place (fishing seat) on the boat. In this test (5), fishing was done after dark with a fish-attracting light on. The fishing lines of Examples 4 and 5 and those of Comparative Examples 5 to 7 were selected because they have the same diameter (0.25 mm).

[0079] Table 10 shows the number of horse mackerel caught and the number of fish other than horse mackerel caught when using the fishing lines of the Example and Comparative Example. The fish other than horse mackerel were lizardfish and rockfish. As is clear from this test (5), the fishing lines of the examples are excellent in terms of catch even when fishing is done under fish-attracting lights.

[0080] [Table 10]

[0081] <Test (6)> Bait fishing was conducted on the fishing pier of the marine fishing pond in Sasebo City, Nagasaki Prefecture on May 11, 2023. Seven testers participated in the fishing for seven hours from 7:00 a.m. to 2:00 p.m. Bait fishing is a fishing method in which a float is attached to a fishing line, the line is extended from the float to a length equivalent to the depth of the water where the fish is to be caught, a leader line is tied to the end of the line 30cm to 2m, a fishing hook is tied to the end of the leader line, and live bait (insects or crustaceans) or paste bait is attached to the fishing hook. The bait fishing is a fishing method in which the fish bites that appear on the float are identified and the fish is caught on the hook by an action called "awase".

[0082] In this test (6), an ultra-high molecular weight polyethylene line with a diameter of 0.24 mm was used as the line, and the length of the line was 1.5 m. The following fishing rods were prepared: (j) a fishing rod using the fishing line of Example 6 as the line, (k) a fishing rod using the fishing line of Example 7 as the line, (l) a fishing rod using the fishing line of Example 8 as the line, (m) a fishing rod using the fishing line of Comparative Example 8 as the line, (n) a fishing rod using the fishing line of Comparative Example 9 as the line, (o) a fishing rod using the fishing line of Comparative Example 10 as the line, and (p) a fishing rod using the fishing line of Comparative Example 11 as the line. Seven testers fished by switching between fishing rods (j) to (p) in turn every hour, as in test (4). In addition, each tester moved from one place to another so that the same tester was not fixed in one place (fishing seat). The fishing lines of Examples 6 to 8 and Comparative Examples 8 to 11 were selected because they had the same diameter (0.40 mm).

[0083] Table 11 shows the number of sea bream caught and the number of fish other than sea bream caught when using the fishing lines of the Example and Comparative Example. The fish other than sea bream were amberjack, stingray, and grouper.

[0084] [Table 11]

[0085] <Test (7)> On April 27, 2023, jigging was conducted from a boat off the coast of the Tango Peninsula in Maizuru City, Kyoto Prefecture. The anglers were five testers, and the time period was five hours from 9:00 a.m. to 2:00 p.m. Jigging is a fishing method in which a few meters of line is tied to the end of a fishing line, and a lure (a metal jig) is attached to the end of the line, mainly targeting yellowtail and various other fish species. In jigging, the captain checks the fish shadows with a fish finder, drops the lure to a specified depth according to the captain's instructions, and then moves the fishing rod up and down from that depth to make the lure jump in the sea and catch the fish on the lure.

[0086] In this test (7), an ultra-high molecular weight polyethylene line with a diameter of 0.24 mm was used as the line, and the length of the line was 7.5 m. The following fishing rods were prepared: (q) a fishing rod using the fishing line of Example 9 as the line, (r) a fishing rod using the fishing line of Example 10 as the line, (s) a fishing rod using the fishing line of Comparative Example 12 as the line, (t) a fishing rod using the fishing line of Comparative Example 13 as the line, and (u) a fishing rod using the fishing line of Comparative Example 14 as the line. Five testers fished by switching fishing rods (q) to (u) in turn every hour, as in test (4). In addition, each tester moved from one place to another so that the same tester was not fixed to one place (fishing seat) on the boat. The fishing lines of Examples 9 and 10 and those of Comparative Examples 12 to 14 were selected because they had the same diameter (0.44 mm).

[0087] Table 12 shows the number of yellowtails caught and the number of fish other than yellowtails caught when using the fishing lines of the Example and Comparative Example. The fish other than yellowtails were sea bream and yellowtail. Yellowtails were defined as fish with a body length of 80 cm or more, and yellowtails were defined as fish with a body length of less than 80 cm.

[0088] [Table 12]

[0089] <Test (8)> On April 9, 2023, we conducted dragonfly jigging from a boat off the coast of Daiozaki, Shima City, Mie Prefecture. The anglers were two testers, and the time period was six hours from 7:00 a.m. to 1:00 p.m. Dragonfly jigging is a fishing method and device similar to the jigging described above, in which several metres of leader line is tied to the end of the main line, and a lure hook (called a metal jig) is attached to the end of the leader line, and the method is aimed primarily at catching skipjack tuna (the same applies below).

[0090] In this test (8), an ultra-high molecular weight polyethylene line with a diameter of 0.34 mm was used as the line, and the length of the line was 7.5 m. (v) A fishing rod using the fishing line of Example 11 as the line, and (w) a fishing rod using the fishing line of Comparative Example 15 as the line were prepared. Two testers fished by exchanging fishing rods (v) and (w) every hour, as in test (4). In addition, each tester moved from one place to another so that the same tester was not fixed to one place (fishing seat) on the boat. The fishing line of Example 11 and the fishing line of Comparative Example 15 were selected because they have the same diameter (0.72 mm).

[0091] Table 13 shows the number of albacore tuna caught and the number of fish other than albacore tuna caught when using the fishing lines of the examples and the comparative examples. The fish other than albacore tuna were skipjack tuna.

[0092] [Table 13]

[0093] <Test (9)> On January 22, 2023, we conducted dragonfly jigging from a boat off the coast of Oshima, Kushimoto-cho, Higashimuro-gun, Wakayama Prefecture. The anglers were two testers, and the time was six hours from 7:00 a.m. to 1:00 p.m. In this test (9), an ultra-high molecular weight polyethylene line with a diameter of 0.34 mm was used as the line, and the length of the line was 7.5 m. (x) A fishing rod using the fishing line of Example 12 as the line, and (y) A fishing rod using the fishing line of Comparative Example 16 as the line were prepared. Two testers fished by exchanging fishing rods (x) and (y) every hour, as in test (4). In addition, each tester moved from one place to another so that the same tester was not fixed to one place (fishing seat) on the boat. The fishing line of Example 12 and the fishing line of Comparative Example 16 were selected because they have the same diameter (1.02 mm).

[0094] Table 14 shows the number of albacore tuna caught and the number of fish other than albacore tuna caught when using the fishing lines of the examples and the comparative examples. The fish other than albacore tuna were blue marlin.

[0095] [Table 14]

[0096] <Test (10)> On March 19, 2024, bottom fishing was conducted from a boat off the coast of Imari City, Saga Prefecture. Eight testers participated in the fishing trip for eight hours from 6:00 a.m. to 2:00 p.m. The fishing method used in this test (10) was to attach squid fillets cut into strips measuring 1 cm x 7 cm to a hook as bait, and to target bottom fish that live mainly on the seabed.

[0097] In this test (10), the following device was used: A 0.15 mm diameter ultra-high molecular weight polyethylene line was used as the fishing line, and a shock leader (1.5 m long, 0.37 mm diameter, commercially available transparent fluorocarbon line) (0.37 mm diameter) was tied to the end of the fishing line. A three-pronged swivel was attached to the end of the shock leader, and a 1.5 m long, 0.29 mm diameter, commercially available fluorocarbon line was tied to one of the tying holes of the three-pronged swivel, and a weight was attached to the end of the line. A 1 m long test fishing line was attached to the other tying hole of the three-pronged swivel in a detachable state. The fishing lines used for the tests were those of Examples 21 to 24 and Comparative Examples 26 to 29 (all of which had a diameter of 2.10 mm). Eight testers changed the fishing lines for each test every hour and fished. Specifically, for example, fishing was performed with a fishing line of Example 21 attached to the other binding hole of the three-pronged swivel for the first hour, and fishing was performed with a fishing line of Example 22 attached to the other binding hole of the three-pronged swivel for the first hour and second hour, instead of the fishing line of Example 21. In addition, the locations of each tester were moved to each other so that the same tester was not fixed to one location (fishing seat) on the boat.

[0098] Table 15 shows the results of fishing by fish species when using the fishing lines of the examples and the comparative examples. In the fish species column of Table 15, "a" stands for rockfish, "b" for scorpionfish, and "c" for red spotted grouper. The ratio of the total number of catches to the highest total number of catches is shown in the table (the same applies to Tables 16 to 19 below). As is clear from the table, the fishing line of the embodiment had a ratio of 70% or more of the total catch, which was superior to the fishing line of the comparative example. In particular, in the case of the embodiment 22, not only was the catch rate high, but several large red spotted groupers of 30 cm or more were caught. This is because it is predicted that there is a specific range of wavelengths that suppresses the feeding instinct of the red spotted grouper, and it is considered that the fishing line of the embodiment 22 did not suppress the feeding instinct of the large red spotted grouper, which is very cautious, by absorbing light of the wavelengths in the specific range.

[0099] [Table 15]

[0100] <Test (11)> On April 12, 2024, bottom fishing was conducted from a boat off the coast of Hirado City, Nagasaki Prefecture. Eight testers participated in the fishing trip for eight hours from 6:00 a.m. to 2:00 p.m. The fishing method and tackle for this test (11) were the same as those for test (10). The fishing lines used for the tests were the fishing lines of Examples 17 to 20 and Comparative Examples 22 to 25 (all of which had a diameter of 1.54 mm). Eight testers fished every hour, changing the fishing line for each test in the same manner as in test (10).

[0101] Table 16 shows the results of fishing by fish species when using the fishing lines of the examples and the comparative examples. In the fish species column of Table 16, "a" stands for rockfish, "b" for scorpionfish, "c" for red spotted grouper, and "d" for red sea bream. As is clear from the table, the fishing lines of the examples had a ratio of 70% or more of the total catches, which was superior to the fishing lines of the comparative examples. In particular, Example 19 not only had a high catch rate, but also caught multiple large red spotted groupers over 30 cm in length. This is thought to be for the same reason as Test (10).

[0102] [Table 16]

[0103] <Test (12)> On April 20, 2024, bottom fishing was conducted from a boat off the coast of Hirado City, Nagasaki Prefecture. The anglers were 11 testers, and the time was 5 hours and 30 minutes from 6:00 a.m. to 11:30 a.m. The fishing method and tackle for this test (12) were the same as those for test (10). The fishing lines used for the tests were the fishing lines of Examples 12 to 16 and Comparative Examples 16 to 21 (all of which had a diameter of 1.02 mm). Eleven testers fished every 30 minutes, changing the fishing line for each test in the same manner as in test (10).

[0104] The results of catching fish when using the fishing lines of the Examples and Comparative Examples are summarized by fish species in Tables 17 and 18. In the fish species column of Table 17, "a" stands for rockfish, "b" for scorpionfish, "c" for red spotted grouper, and "d" for red sea bream. As is clear from the table, the fishing lines of the examples accounted for 70% or more of the total catches, and were superior to the fishing lines of the comparative examples. In particular, examples 14 and 15 not only had a high catch rate, but also caught multiple large red spotted groupers and red sea bream that were 30 cm or more in length. This is thought to be for the same reason as in test (10).

[0105] [Table 17]

[0106] [Table 18]

[0107] <Test (13)> On February 7, 2024, we conducted horse mackerel fishing using a fishing method called ajing at the dock of the fishing port in Karatsu City, Saga Prefecture. The anglers were seven testers, and the time was seven hours from 9:00 a.m. to 4:00 p.m. Ajing is a fishing method in which the bait is lowered and the jig head hook is moved by operating the rod, primarily targeting horse mackerel and various other species of fish.

[0108] In this test (13), the following setup was used: A 0.045 mm diameter ultra-high molecular weight polyethylene line was used as the fishing line, a shock leader was tied to the end of the fishing line, and a 1 g jig head needle was tied to the end of the leader. A resin lure worm was attached to the jig head needle. A test fishing line with a length of 1 m was used as the shock leader. The test fishing lines used were the fishing lines of Examples 1 to 3 and Comparative Examples 1 to 4 (all of which had a diameter of 0.12 mm). Seven testers changed the fishing lines for each test every hour. Specifically, for the first hour, they fished with a tackle using the fishing line of Example 1 as a shock leader, and from hour 1 to hour 2, they fished with a tackle using the fishing line of Example 2 instead of the fishing line of Example 1. In addition, each tester was moved to another location so that the same tester was not fixed to one location (fishing seat) at the pier.

[0109] The catch results for each of the fishing lines of the Examples and Comparative Examples are summarized by fish species in Table 19. In the fish species column of Table 18, "e" stands for horse mackerel and "f" stands for barracuda. As is clear from the table, the fishing lines of the examples accounted for 70% or more of the total catches, and were superior to the fishing lines of the comparative examples. In particular, examples 1 and 2 not only had a high catch rate, but also caught multiple large horse mackerel over 30 cm and barracudas over 40 cm. This is thought to be because the light that passed through the fishing lines of examples 1 and 2 did not suppress the feeding instincts of large horse mackerel and barracudas.

[0110] [Table 19]

[0111] FIG. 16 is a graph plotting the relationship between the line diameter (diameter of fishing line) of each example and comparative example and the spectral transmittance L0Z at a wavelength of 525 nm. In FIG. 16, for example, three black circles and four crosses are shown on the line diameter of 0.12 mm. With reference to Table 1, the three points are Examples 1 to 3, and with reference to Table 3, the four points are Comparative Examples 1 to 4. Similarly, corresponding examples and comparative examples are plotted on line diameters of 0.25 mm, 0.40 mm, 0.44 mm, 0.72 mm, 1.02 mm, 1.54 mm, and 2.10 mm. Please refer to Tables 1 to 5 for the numerical values ​​of line diameter and spectral transmittance. The reason why the inventors focused on the spectral transmittance L0Z of the wavelength 525 nm in the wavelength range of 425 nm to 575 nm is because saltwater fish are particularly sensitive to light of 520 nm. Also, the reason why the inventors focused on the line diameter is because they empirically recognize that the line diameter is an important factor that affects the catch. In FIG. 16, the fishing lines of the examples, represented by black circles, are fishing lines that can be expected to produce good results for various fish species through actual fishing tests, and have a spectral transmittance L0Z within a predetermined range for each line diameter. The fishing lines of the comparative examples, represented by crosses, are fishing lines that cannot be expected to produce good results. As is clear from FIG. 16, the fishing lines of the examples fall within a predetermined range in terms of the relationship between spectral transmittance L0Z and line diameter, while the fishing lines of the comparative examples fall outside of the range. The test results show that fishing lines whose relationship between spectral transmittance L0Z and line diameter falls within a predetermined range are fishing lines that can be expected to produce good results.

[0112] In order to determine the range of fishing lines that can be expected to produce good catches, the upper and lower boundary lines of the examples and comparative examples were approximated by the least squares method. FIG. 17 is a graph in which an approximation curve representing the boundary between the embodiment and the comparative example is drawn on the graph of FIG. As shown in FIG. 17, for example, the upper limit of the spectral transmittance of the embodiment with a line diameter of 0.12 mm is 38%. This 38% is the spectral transmittance of Example 1 at 525 nm (see Table 1). The spectral transmittance of the comparative example closest to this upper limit is 42%, which is the spectral transmittance of Comparative Example 2 (see Table 3). It is believed that the boundary between the embodiment and the comparative example lies between the 38% and 42%, that is, the boundary between a fishing line that is good at catching fish and a fishing line that is not. The lower limit of the spectral transmittance of the embodiment with a line diameter of 0.12 mm is 30%. This 30% is the spectral transmittance of Example 3 at 525 nm (see Table 1). The spectral transmittance of the comparative example closest to this lower limit is 28%, which is the spectral transmittance of Comparative Example 3 (see Table 3). It is believed that the boundary between a fishing line that is good at catching fish and a fishing line that is not good at catching fish lies between the 30% and 28%. Similarly, the spectral transmittance of the upper limit value of the Example and the spectral transmittance of the Comparative Example closest thereto for each of the yarn diameters of 0.40 mm, 0.44 mm, 1.02 mm, 1.54 mm, and 2.10 mm, as well as the spectral transmittance of the lower limit value of the Example and the spectral transmittance of the Comparative Example closest thereto, were extracted. These are shown in Table 20. Please refer to Tables 1 to 5 for which Example and Comparative Example these spectral transmittances correspond to. Note that the lower limit value of 0.44 mm and the yarn diameter of 0.72 mm are omitted because the number of data is small.

[0113] [Table 20]

[0114] As shown in Table 20, for each yarn diameter, the upper limit of the spectral transmittance of the example and the average value of the spectral transmittance of the comparative example closest to this upper limit were calculated. This average value is shown in column (3) of Table 20. Using the data in column (3) with the spectral transmittance YU on the vertical axis and the yarn diameter X on the horizontal axis, the least squares method was applied to calculate an approximation curve by power approximation (see FIG. 17). As a result, the following formula (5) was obtained. Formula (5): YU=25.077X -0.231 Similarly, for each yarn diameter, the average value of the lower limit of the spectral transmittance of the example and the spectral transmittance of the comparative example closest to this lower limit was calculated. This average value is shown in column (6) of Table 20. Using the data in column (6) with the spectral transmittance YD on the vertical axis and the yarn diameter X on the horizontal axis, the least squares method was applied to calculate an approximation curve by power approximation (see FIG. 17). As a result, the following formula (6) was obtained. Equation (6): YD=12.936X -0.378 By rounding off the decimal points, the spectral transmittance L0Z at a wavelength of 525 nm is 25.1X -0.23 > L0Z > 12.9X -0.38 It can be said that a fishing line that satisfies these requirements can be expected to produce good catches. [Explanation of symbols]

[0115] 1. Fishing Line

Claims

1. A method for producing a fishing line by spinning a forming material containing a colorant and a resin component, comprising: The fishing line has a spectral transmittance in the wavelength range of 425 nm to 575 nm of 13% to 40%, and a spectral transmittance L0Z of 25.1X at a wavelength of 525 nm. －０．２３ >L0Z>12.9X －０．３８ (wherein X represents the diameter of the fishing line (mm)).

2. The method of claim 1 , wherein the resin component comprises polyvinylidene fluoride.

3. Contains a colorant and a resin component, The spectral transmittance in the wavelength range of 425 nm to 575 nm is 13% to 40%, The spectral transmittance L0Z at a wavelength of 525 nm is 25.1X －０．２３ >L0Z>12.9X －０．３８ (wherein X represents the diameter (mm) of the fishing line).

4. Measure the spectral transmittance and diameter of the fishing line, The spectral transmittance in the wavelength range of 425 nm to 575 nm is 13% to 40%, and the spectral transmittance L0Z at a wavelength of 525 nm is 25.1X －０．２３ >L0Z>12.9X －０．３８ (wherein X represents the diameter (mm) of the fishing line).

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