Fishing line

Abstract

This fishing line contains a colorant and has a spectral transmittance of 13 to 40% in a wavelength range of 425 to 575 nm. Said fishing line can be expected to yield a favorable catch for various fish species.

Description

fishing line

[0001] The present invention relates to a fishing line for fishing.

[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. To increase catches, it is important that the fishing line is not noticeable to the fish. Therefore, while it is desirable to use as thin a fishing line as possible to avoid alerting the fish, if the fishing line is too thin, the line is more likely to break when a large fish is hooked. Therefore, a fishing line that is difficult for fish to notice is desirable. Patent Document 1 discloses a colored fishing line for saltwater fishing that has an absorption maximum 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 notice and is therefore suitable for use with these fish species.

[0003] Japanese Patent Application Laid-Open No. 2003-52287

[0004] However, although 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.

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

[0006] A fishing line according to a first embodiment of the present invention contains a colorant and has a spectral transmittance of 13% to 40% in the wavelength range of 425 nm to 575 nm.

[0007] The fishing line according to a second aspect of the present invention is the fishing line of the first aspect, except that the spectral transmittance has a maximum and minimum value in the wavelength range of 425 nm to 575 nm, and the difference between the maximum and minimum values ​​is within 13%. The fishing line according to a third aspect of the present invention is the fishing line of the first or second aspect, except that there are multiple spectral transmittance peaks in the wavelength range of 425 nm to 575 nm. The fishing line according to a fourth aspect of the present invention is the fishing line of any of the first to third aspects, except that the spectral reflectance in the wavelength range of 425 nm to 700 nm is 26% or less. The fishing line according to a fifth aspect of the present invention is the fishing line of any of the first to fourth aspects, except that it is made of a monofilament containing the colorant and polyvinylidene fluoride resin.

[0008] By using the fishing line of the present invention, good results can be obtained for various fish species, particularly various saltwater fish.

[0009] 1 is a front view of a fishing line with both ends omitted; an enlarged cross-sectional view taken along line II-II in FIG. 1; a reference graph showing the photosensitivity of saltwater fish for each wavelength; a front view of the fishing line wound around a glass plate, illustrating a method for measuring the reflectance of a fishing line; a reference graph of the glass plate around which the fishing line is wound placed on an integrating sphere, illustrating a method for measuring the reflectance of a fishing line; a graph of the spectral reflectance L1, spectral reflectance L2, and spectral transmittance L0 of the fishing line of Example 1; a graph of the spectral reflectance L2 and spectral transmittance L0 of the fishing lines of Examples 2 to 5; a graph of the spectral reflectance L2 and spectral transmittance L0 of the fishing lines of Examples 6 to 9; a graph of the spectral reflectance L2 and spectral transmittance L0 of the fishing lines of Examples 10 and 11; a graph of the spectral transmittance L0 of the fishing lines of Comparative Examples 1 to 6; a graph of the spectral transmittance L0 of the fishing lines of Comparative Examples 7 to 10.

[0010] In this specification, a numerical range expressed as "lower limit X to upper limit Y" means a range from lower limit X to upper limit Y. When a plurality of such numerical ranges are separately described, any lower limit and any upper limit can be selected to set "any lower limit to any upper limit."

[0011] The fishing line of the present invention has a spectral transmittance of 13% to 40% in the wavelength range of 425 nm to 575 nm. From the viewpoint of line construction, the fishing line may be a monofilament, or a fused line formed by fusing multiple thin monofilaments together to form a single line. Monofilament is preferred because of its excellent durability.

[0012] 1 and 2, the fishing line 1 of the present invention is a long, thin thread that is generally circular in cross section. The diameter of the fishing line 1 can be set as appropriate, for example, between 0.1 mm and 2.5 mm.

[0013] In terms of composition, fishing lines contain a resin component and a colorant, and may contain any appropriate additives as needed. Examples of such additives include light stabilizers, UV absorbers, antioxidants, crystallization inhibitors, and plasticizers. The resin component is not particularly limited, and examples include vinylidene resins such as polyvinylidene fluoride, olefin resins such as high-molecular-weight polyethylene, polyamide resins, polyester resins, and polyamide resins. Fishing lines containing vinylidene resins such as polyvinylidene fluoride are preferred because of their high strength, abrasion resistance, weather resistance, and low water absorption, as well as their refractive index close to that of water. The colorant is not particularly limited as long as it satisfies the spectral transmittance requirements in the wavelength range. Typical examples of such colorants include pigments and dyes, such as inorganic and organic pigments. These can be used alone or in combination. 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 pigments, azo pigments, and perylene pigments. Examples of the dyes include auramine, fuchsine, methylene blue, malachite green, crystal violet, and cationic dyes.

[0014] Pigments are preferably used as colorants because they have excellent dye absorption and can produce fishing lines with high fastness. Furthermore, among pigments, organic pigments are more preferred because they are less likely to break during fishing line production. The colorant content is appropriately determined. In terms of the relationship between the colorant content and the fishing line diameter, fishing lines in which the colorant content Y0 satisfies the following formula (1) are preferred. In particular, fishing lines containing organic pigments as colorants and polyvinylidene fluoride resin as a resin component preferably satisfy the following formula (1). Fishing lines that satisfy the following formula (1) improve catch rates for many species of saltwater and freshwater fish. Specifically, according to research by the present inventors, if the colorant content Y0 is Y2 or less, there is a risk that catch rates will be similar to those of uncolored fishing lines. If the colorant content Y0 is Y1 or more, there is a risk that fish (both saltwater and freshwater) will bite less frequently than with uncolored fishing lines. It is estimated that there is an interaction between the above-mentioned spectral transmittance range and the content of the colorant with respect to the fishing result. －０．５９８ Formula (3): Y2=0.0016X －０．５８０ where X represents the diameter (mm) of the fishing line, Y0 represents the colorant content (wt%), Y1 represents the upper limit (wt%) of the colorant content, and Y2 represents the lower limit (wt%) of the colorant content.

[0015] Furthermore, in terms of the relationship between spectral transmittance and diameter of the fishing line, a fishing line whose spectral reflectance at a wavelength of 525 nm satisfies the relationship of the following formula (4) is preferred. Fishing lines that satisfy the relationship of the following formula (4) improve the catch rate for many species of saltwater and freshwater fish. Specifically, according to research by the inventors, if the spectral transmittance Z0 at a wavelength of 525 nm is less than Z1 or more than Z2, there is a risk that the frequency of saltwater fish biting will decrease. Formula (4): Z2<Z0<Z1 Formula (5): Z1=24.5X －０．２６ Formula (6): Z2=12.1X －０．４４ where X represents the diameter (mm) of the fishing line, Z0 represents the spectral transmittance (%) of the fishing line at a wavelength of 525 nm, Z1 represents the upper limit (%) of the spectral transmittance, and Z2 represents the lower limit (%) of the spectral transmittance.

[0016] The fishing line can be manufactured by a known spinning method. A brief explanation will be given, taking as an example a fishing line made of a polyvinylidene fluoride resin monofilament. A resin composition is prepared by mixing a polyvinylidene fluoride resin with a colorant and, if necessary, additives. The resin composition is filled, for example, into the hopper of an extruder-type spinning machine, and melt-extruded through a spinneret 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 to form a fiber. The monofilament spun from the extruder is cooled in a cooling bath. A liquid inert to the polyvinylidene fluoride resin, such as glycerin, polyethylene glycol, water, or a mixture thereof, is used as the cooling bath. The cooled monofilament is stretched and heat-set. The stretching process may be a single-stage stretching process, but is typically a multi-stage stretching process. The heat treatment for stretching and heat setting is not particularly limited, and examples thereof include passing the filaments through a dry heat space in a hot atmosphere such as an oven or hot air, or immersing the filaments in a heat medium bath such as silicone oil. The total stretching ratio is, for example, 5 to 7 times.

[0017] The fishing line of the present invention has a spectral transmittance of 13% to 40% in the wavelength range of 425 nm to 575 nm. A spectral transmittance of 13% to 40% in the wavelength range of 425 nm to 575 nm means that the spectral transmittance over 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, the fishing line preferably has a difference (maximum minus minimum) between the maximum spectral transmittance in the wavelength range of 425 nm to 575 nm and the minimum spectral transmittance in the wavelength range of 425 nm to 575 nm of 13% or less, and more preferably 6% to 12%, and even more preferably 8% to 11%. Furthermore, the fishing line preferably has a spectral transmittance at a wavelength of 525 nm of 13% to 30%, more preferably 14% to 29%, and even more preferably 17% to 27%.

[0018] The fishing line also has a spectral transmittance of 18% or more, and preferably 20% or more, in the wavelength range of 575 nm to 700 nm. The spectral transmittance of the fishing line can be measured using the "Method for 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 and reflected from the fishing line (spectral reflectance L1) is measured, the reflectance of light reflected by the fishing line (spectral reflectance L2) is measured, and the spectral transmittance L0 of the fishing line can be determined by subtracting spectral reflectance L2 from spectral reflectance L1.

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

[0020] The fishing line of the present invention can be expected to produce good results for various fish species, especially various saltwater fish. In other words, by using the fishing line of the present invention, it is possible to catch a relatively large number of fish species. This is also clear from the "Actual Fishing Evaluation" in the Examples below. The reason why such good results can be expected is not clear, but the inventors speculate as follows.

[0021] A relatively recent research paper, "Fish Habitats and Color Vision" (Received June 10, 2021, Kyoichi Takahashi, 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 states that of the 54 species of marine fish, only five species are photosensitive in the red region, and most marine fish are photosensitive in the wavelength regions of 420 nm to 480 nm (blue region) and 500 nm to 580 nm (green region).

[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 perceive the captured colors as the color and brightness of the line. Fish that are targeted for fishing include those that can distinguish colors and those that cannot. Fish that can distinguish colors include sea bass, flounder, black sea bream, Japanese flounder, and sweetfish. Fish that cannot distinguish colors include cod, conger eel, alfonsino, and lizardfish. Fish that live in the deep sea, where light cannot reach, often cannot distinguish colors either. While mollusks such as the common octopus, bigfin reef squid, and cuttlefish cannot strictly be called fish, this specification considers such mollusks to be targeted for fishing and therefore includes them as target fish. These fish recognize the presence of a fishing line by recognizing color and light and shade. In particular, fish can detect the presence of a transparent fishing line by recognizing light and shade. According to the present invention, a fishing line with a specific spectral transmittance and spectral reflectance in a predetermined wavelength range makes the presence of the fishing line less noticeable to fish. 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 only a small amount of light in that wavelength range. Because such a fishing line is less permeable to light in that wavelength range (fish that can distinguish colors have relatively high photosensitivity in the 425 nm to 575 nm wavelength range), it is less noticeable to various fish species that can distinguish colors. As a result, it is expected that good catches of fish that can distinguish colors can be expected. In particular, fishing lines with a spectral reflectance of 26% or less in the wavelength range of 425 to 575 nm, where the difference between the maximum and minimum values ​​(maximum minus minimum) is within 13%, are considered effective against a variety of fish species because the amount of light transmitted within this wavelength range does not change significantly. Furthermore, fishing lines with a spectral reflectance of 26% or less in the wavelength range of 425 to 700 nm reflect little light. This makes it difficult for fish to recognize the fishing line due to the light reflected by the line.In particular, fishing lines with a spectral reflectance difference (maximum minus minimum) of 9% or less between the maximum and minimum values ​​in the wavelength range of 425 nm to 700 nm reflect a similar amount of light across almost the entire visible light spectrum. Therefore, the light reflected by the fishing line becomes nearly white, making it difficult for fish to distinguish between the fishing line and the surrounding waters. (Although there is a difference in brightness between the fishing line and the surrounding waters, it is difficult to distinguish between the fishing line and the surrounding waters based on this difference in brightness in water where light is difficult to reach.) This makes it difficult for fish to recognize the fishing line due to the reflected light. As a result, it is estimated that good catches of various fish species can be expected.

[0023] The present invention will be further explained below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0024] [Method for measuring spectral transmittance L0] As shown in Figure 4, the fishing line to be measured was tightly wound in a single layer around a glass slide for an optical microscope and fixed so that it would not come off. Hereinafter, in this section, the glass slide around which the fishing line was tightly wound in a single layer is referred to as the "sample plate."

[0025] <Measurement of Spectral Reflectance L1> The sample plate was placed on the surface of a white background plate as shown in FIG. 5 and secured to prevent movement. The sample plate was set so that the fishing line protruded from the window of a commercially available integrating sphere device. A commercially available spectrophotometer (product name "V-650" manufactured by JASCO Corporation) was used, with its light source (halogen lamp) and detector positioned as shown in FIG. 5. Light was irradiated from the light source onto the area of ​​the sample plate where the fishing line was densely packed. The reflected light was detected by the detector, and 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 ranged from 400 nm to 750 nm, and measurements were performed over a 5 nm bandwidth at 0.5 nm intervals. The reflected light here consisted 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 was 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.

[0026] <Measurement of Spectral Reflectance L2> 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 consisted of light reflected by the fishing line (because light transmitted through the fishing line was absorbed by the black background plate). Therefore, the spectral reflectance L2 was equal to the spectral reflectance of light reflected by the fishing line.

[0027] <Calculation of Spectral Transmittance L0> The spectral transmittance L0 of the fishing line was calculated by subtracting the spectral transmittance L2 from the spectral transmittance L1: Spectral transmittance L0 of the fishing line = L1 - L2.

[0028] [Method for Measuring Fishing Line Diameter] The diameter (mm) of the fishing line was measured using a micrometer manufactured by Mitutoyo Corporation. 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).

[0029] [Tensile Breaking Strength and Tensile Elongation] In accordance with the provisions of JIS L 1013, the fishing line was 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") at a sample length of 300 mm and a pulling 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 (kgf) and tensile elongation (%).

[0030] [Knot Breaking Strength] In accordance with the provisions of JIS L 1013, fishing lines were tightly knotted with a single square knot. As in the above [Tensile Breaking Strength and Tensile Elongation], these lines were used as test subjects, and after leaving them in a temperature and humidity controlled room for 24 hours, the knot breaking strength was measured using a tensile tester (manufactured by Shimadzu Corporation under the trade name "Autograph S-500D"). Five measurements were taken for each fishing line, and the average value was used as the knot breaking strength (kgf).

[0031] Example 1 Polyvinylidene fluoride homopolymer chips containing 80 ppm of organic pigment (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) were fed into a spinning machine, heated to 260°C to melt, extruded through a 1.6 mm orifice, 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 to a total draw ratio of 6 times 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 0.25 mm.

[0032] The spectral transmittance of the fishing line of Example 1 was measured. The results are shown in Figure 6. As shown in Figure 6, there were multiple peaks in the spectral transmittance L0 (the peaks are marked with arrows in Figure 6). Table 1 also lists the maximum (A) and minimum (B) values ​​of the spectral transmittance L0 in the wavelength range of 425 nm to 575 nm, as well as the difference between the maximum and minimum values ​​(A-B). Table 1 also lists the maximum (C) and minimum (D) values ​​of the spectral transmittance L0 in the wavelength range of 575 nm to 700 nm, as well as the difference between the maximum and minimum values ​​(C-D). Table 1 also lists the maximum (E) and minimum (F) values ​​of the spectral reflectance L2 in the wavelength range of 425 nm to 700 nm, as well as the difference between the maximum and minimum values ​​(E-F). 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.

[0033]

[0034] [Examples 2 to 11] Fishing lines of Examples 2 to 11 were produced in the same manner as Example 1, except that at least one of the amount of organic pigment, the hole diameter of the spinneret, and the draw ratio was changed as shown in Table 1. Note that changing the hole diameter of the spinneret changes the diameter of the resulting fishing line.

[0035] The spectral transmittance was also measured for each of the fishing lines of Examples 2 to 11. The results are shown in Figures 7 to 9. Note that Figures 7 to 9 also show graphs of the spectral reflectance L2 and the spectral transmittance L0 for each of the fishing lines of Examples 2 to 11. As mentioned above, the spectral reflectance L2 is the reflectance consisting only of light reflected from the fishing line. As shown in Figures 7 to 9, the fishing lines of Examples 2 to 11 also had multiple peaks in the spectral transmittance L0. Table 1 also lists the maximum and minimum values ​​of the spectral transmittance L0 in the wavelength range of 425 nm to 575 nm, as well as the difference (A - B) between the maximum and minimum values. Furthermore, the maximum (C) and minimum (D) values ​​of spectral transmittance L0 in the wavelength range of 575 nm to 700 nm, as well as the difference between these maximum and minimum values ​​(C-D), are shown in Table 1, and the maximum (E) and minimum (F) values ​​of spectral reflectance L2 in the wavelength range of 425 nm to 700 nm, as well as the difference between these maximum and minimum values ​​(E-F), are shown in Table 1. Furthermore, the diameter, tensile breaking strength, tensile elongation, and knot breaking strength of the fishing lines of Examples 2 to 11 were measured. The results are shown in Table 1.

[0036] Comparative Example 1 A fishing line of Comparative Example 1 was produced in the same manner as in Example 1, except that no organic pigment (colorant) was added.

[0037] Comparative Example 2 A fishing line (colored polyvinylidene fluoride monofilament) of Comparative Example 2 was produced using dyeing instead of an organic pigment. Specifically, a fishing line (uncolored polyvinylidene fluoride monofilament) with a diameter of 0.25 mm was produced in the same manner as in Example 1, except that no organic pigment (colorant) was added. This fishing line was passed through a dye bath with a length of 3 m at a speed of 20 m / min and then dried to produce the fishing line (colored polyvinylidene fluoride monofilament) of Comparative Example 2. The dye bath was filled with a dye solution (2% concentration) in which a cationic dye was dissolved, and the temperature of the solution was set to 80°C.

[0038] Comparative Example 3 A fishing line of Comparative Example 3 was produced in the same manner as in Example 1, except that the amount of organic pigment was changed to 250 ppm.

[0039] [Comparative Examples 4, 6, 9, and 10] The fishing lines of Comparative Examples 4, 6, 9, and 10 were produced in the same manner as in Example 1, except that no organic pigment (colorant) was added and the hole diameter of the nozzle (the diameter of the resulting fishing line) was changed as shown in Table 2.

[0040] [Comparative Examples 5 and 7] The fishing lines of Comparative Examples 5 and 7 were produced in the same manner as in Example 1, except that the polyvinylidene fluoride homopolymer chips containing an organic pigment were replaced with polyvinylidene fluoride homopolymer chips containing 24 ppm of dye-based dry color (manufactured by Nippon Kasei Co., Ltd.), and the hole diameter of the nozzle (the diameter of the resulting fishing line) was changed as shown in Table 2.

[0041] Comparative Example 8 The fishing line of Comparative Example 8 was produced in the same manner as in Example 1, except that the amount of organic pigment was changed to 30 ppm and the hole diameter of the nozzle (the diameter of the resulting fishing line) was changed as shown in Table 2.

[0042] The spectral transmittance was also measured for each of the fishing lines of Comparative Examples 1 to 10. The results are shown in Figures 10 and 11. Note that Figures 10 and 11 also show graphs of the spectral transmittance L0 for each of the fishing lines of Comparative Examples 1 to 10. Table 2 also lists the maximum and minimum values ​​of spectral transmittance L0 in the wavelength range of 425 nm to 575 nm, as well as the difference (A-B) between the maximum and minimum values. Furthermore, the diameter, tensile breaking strength, tensile elongation, and knot breaking strength of the fishing lines of Comparative Examples 1 to 10 were measured. The results are shown in Table 2.

[0043]

[0044] [Evaluation of Actual Fishing] Using the fishing lines of the Examples and Comparative Examples, actual sea fishing was carried out, and the catches were evaluated.

[0045] <Test (1)> Tip run fishing was conducted from a boat off the coast of Imari City, Saga Prefecture on April 17, 2023. Four testers were involved in the fishing, and the time was two hours from 6:00 AM to 8:00 AM. The testers are professional anglers who test fishing gear, and are also called field testers (hereinafter the same). Tip run fishing is a fishing method that primarily targets bigfin reef squid lurking on the seabed, using a rig in which a shock leader is tied several meters to the end of the fishing line, and a tip run lure is tied to the end of the shock leader.

[0046] 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 shock leader was 2 m long. Two testers used the fishing line of Example 1 as the shock leader, and the remaining two testers used the fishing line of Comparative Example 1 (0.25 mm diameter) as the shock leader. The reason for choosing the fishing line of Example 1 and the fishing line of Comparative Example 1 is that they have the same diameter (0.25 mm). Since using fishing lines with different diameters could result in different catches due to the difference in diameter, the Example and Comparative Examples with the same diameter were chosen. The catches are shown in Table 3.

[0047]

[0048] As shown in Table 3, when the fishing line of Example 1 was used, the catch rate was better than when the fishing line of Comparative Example 1 was used. According to literature (Nippon Suisan Gakkaishi 80(2), 245(2014)), the maximum absorption wavelength of the oval squid is 494 nm, and although oval squids do not have color vision, it is estimated that they can sense light in the absorption wavelength range of rhodopsin. The fishing line of Example 1 is less susceptible to light with wavelengths of 425 nm to 575 nm than the fishing line of Comparative Example 1. Therefore, the inventors estimate that the fishing line of Example 1 is less sensitive than the fishing line of Comparative Example 1, which reduces the wariness of the oval squid and improves the catch rate.

[0049] <Test (2)> On April 17, 2023, red snapper fishing was conducted from a boat off the coast of Imari City, Saga Prefecture. Three testers were involved in the fishing, and the time was eight hours from 8:00 AM to 4:00 PM. Red snapper fishing is a fishing method that primarily targets red snapper and various other fish species by tying a shock leader several meters to the end of the fishing line, and 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 (hereinafter the same). 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 length of the shock leader was 3 m. One tester used the fishing line of Example 4 (diameter 0.40 mm) as the shock leader, and the remaining two testers used the fishing line of Comparative Example 4 (diameter 0.40 mm) as the shock leader. The reason for choosing the fishing line of Example 4 and the fishing line of Comparative Example 4 is that they have the same diameter (0.40 mm). The catch is shown in Table 4.

[0050]

[0051] As shown in Table 4, when the fishing line of Example 4 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 4 was used.

[0052] <Test (3)> On April 28, 2023, red snapper fishing was conducted from a boat off the coast of Imari City, Saga Prefecture. Six anglers were testers, and the test time was 10 hours from 6:00 am to 4:00 pm.

[0053] In this test (3), a 0.15 mm diameter ultra-high molecular weight polyethylene line was used as the lead line, and the shock leader was 3 m long. Two testers used the fishing line of Example 5 (0.40 mm diameter) as the shock leader, two testers used the fishing line of Comparative Example 4 (0.40 mm diameter) as the shock leader, and the remaining two testers used the fishing line of Comparative Example 5 (0.40 mm diameter) as the shock leader. On the boat, anglers were positioned so that anglers using the same shock leader were not next to each other. The reason for choosing the fishing line of Example 5 and the fishing lines of Comparative Examples 4 and 5 was that they had the same diameter (0.40 mm). The fishing results are shown in Table 5.

[0054]

[0055] As shown in Table 5, when the fishing line of Example 5 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 4 was used.

[0056] <Test (4)> On May 16, 2023, we went to a reef off the coast of Ikitsuki, Hirado City, Nagasaki Prefecture, and conducted fukase fishing. Four testers participated, and the test lasted for eight hours, from 6:00 AM to 2:00 PM. Fukase 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 water depth at which the fish is to be caught, a leader line of approximately 2 to 3 meters is tied to the end of the float, a fishing hook is tied to the end of the leader line, and bait such as krill is attached to the fishing hook. Fukase fishing is a fishing method in which the fish bite that appears on the float is identified and the fish is hooked on the hook using an action known as hooking.

[0057] In this test (4), the target fish was set to black seabream, and a nylon line with a diameter of 0.23 mm was used as the main line, with the length of the leader line being 3 m. The following fishing rods were prepared: (a) a fishing rod using the fishing line of Example 1 as the leader line; (b) a fishing rod using the fishing line of Comparative Example 1 as the leader line; (c) a fishing rod using the fishing line of Comparative Example 2 as the leader line; and (d) a fishing rod using the fishing line of Comparative Example 3 as the leader line. Four testers fished by switching between fishing rods (a) to (d) every hour (for example, from 6:00 AM to 7:00 AM, the first tester fished with fishing rod (a), the second tester with fishing rod (b), the third tester with fishing rod (c), and the fourth tester with fishing rod (d); from 7:00 AM to 8:00 AM, the first tester fished with fishing rod (d), the second tester with fishing rod (a), the third tester with fishing rod (b), and the fourth tester with fishing rod (c)...). In addition, the testers were moved from one location to another so that the same tester would not be fixed in one location (fishing seat). The reason for selecting the fishing line of Example 1 and the fishing lines of Comparative Examples 1 to 3 is that they have the same diameter (0.25 mm).

[0058] Table 6 shows the number of sea bream caught and the number of fish other than sea bream caught using each of the fishing lines of the example and comparative example. The fish other than sea bream were grunt, small red sea bream, and rockfish. In the fishing line evaluation column of Table 6, "◎" indicates the fishing line that produced the highest number of catches, "◯" indicates the fishing line that produced 75% or more of the highest number of catches, "△" indicates the fishing line that produced 50% to 75% of the highest number of catches, and "×" indicates the fishing line that produced less than 50% of the highest number of catches (the same applies to Tables 7 to 11).

[0059]

[0060] <Test (5)> On May 11, 2023, a baitcasting test was conducted from a boat off the coast of Imari City, Saga Prefecture. Five anglers were testers, and the test time was five hours from 6:00 PM to 11:00 PM. Baitcasting involves tying a few meters of line to the end of the main line, attaching a weight to the end of the line, tying a 5-30 cm long branch line to the line a few tens of cm above the weight, attaching a jig head weighing several grams to the end of the branch line, and attaching lugs or artificial bait (such as resin worms) to the jig head. This is a fishing method that mainly targets horse mackerel and various other fish species.

[0061] In this test (5), a 0.15 mm diameter ultra-high molecular weight polyethylene line was used as the main line, with the leader length being 2 m and the branch leader length being 20 cm. The following fishing rods were prepared: (e) a fishing rod using the fishing line of Example 1 as the leader and branch leader; (f) a fishing rod using the fishing line of Example 2 as the leader and branch leader; (g) a fishing rod using the fishing line of Comparative Example 1 as the leader and branch leader; (h) a fishing rod using the fishing line of Comparative Example 2 as the leader and branch leader; and (i) a fishing rod using the fishing line of Comparative Example 3 as the leader and branch leader. As in <Test (4)>, five testers fished by switching between the fishing rods (e) to (i) every hour. Furthermore, each tester was moved from one location to another so that the same tester was not fixed to the same place (fishing seat) on the boat. In this test (5), fishing was conducted after dark with a fishing light illuminating the rods. The reason why the fishing lines of Examples 1 and 2 and Comparative Examples 1 to 3 were selected is because they have the same diameter (0.25 mm).

[0062] Table 7 shows the number of horse mackerel caught and the number of fish other than horse mackerel caught 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 Example are excellent in terms of catch, even when fishing is done under a fishing light.

[0063]

[0064] <Test (6)> Bait fishing was conducted on May 11, 2023, on a fishing pier at an ocean fishing pond in Sasebo City, Nagasaki Prefecture. Seven testers participated in the experiment, which lasted for seven hours from 7:00 AM to 2:00 PM. Bait fishing involves attaching a float to a fishing line, extending the line from the float to a length equivalent to the water depth at which the fish is to be caught, tying a 30 cm to 2 m leader line to the end of the float, and tying a fishing hook to the end of the leader line, with live bait (insects or crustaceans) or paste bait attached to the hook. Bait fishing involves identifying the fish's bite that appears on the float and then hooking the fish on the hook using a technique known as hooking.

[0065] In this test (6), an ultra-high molecular weight polyethylene line with a diameter of 0.24 mm was used as the main line, and the length of the leader line was 1.5 m. The following fishing rods were prepared: (j) a fishing rod using the fishing line of Example 3 as the leader line; (k) a fishing rod using the fishing line of Example 4 as the leader line; (l) a fishing rod using the fishing line of Example 5 as the leader line; (m) a fishing rod using the fishing line of Example 6 as the leader line; (n) a fishing rod using the fishing line of Example 7 as the leader line; (o) a fishing rod using the fishing line of Comparative Example 4 as the leader line; and (p) a fishing rod using the fishing line of Comparative Example 5 as the leader line. As in <Test (4)>, seven testers fished by switching between the fishing rods (j) to (p) in order every hour. Furthermore, each tester was moved from one location to another so that the same tester was not fixed in the same place (fishing seat). The fishing lines of Examples 3 to 7 and Comparative Examples 4 and 5 were selected because they had the same diameter (0.40 mm).

[0066] Table 8 shows the number of sea bream caught and the number of fish other than sea bream caught using the fishing lines of the Example and Comparative Example. The fish other than sea bream were amberjack, ray, and grouper.

[0067]

[0068] <Test (7)> ​​On April 27, 2023, jigging was conducted from a boat off the coast of the Tango Peninsula in Maizuru City, Kyoto Prefecture. Five testers participated in the experiment, which lasted for five hours from 9:00 AM to 2:00 PM. Jigging is a fishing method that primarily targets yellowtail and various other fish species by tying several meters of leader line to the end of the main line and attaching a lure (a metal jig) to the end of the leader line. Jigging involves the captain checking fish shadows with a fish finder, dropping the lure to a specified depth according to the captain's instructions, and then moving the fishing rod up and down from that depth to make the lure dance in the sea and catch fish on the lure.

[0069] In this test (7), an ultra-high molecular weight polyethylene line with a diameter of 0.24 mm was used as the main line, and the length of the leader line was 7.5 m. The following fishing rods were prepared: (q) a fishing rod using the fishing line of Example 8 as its leader line; (r) a fishing rod using the fishing line of Example 9 as its leader line; (s) a fishing rod using the fishing line of Comparative Example 6 as its leader line; (t) a fishing rod using the fishing line of Comparative Example 7 as its leader line; and (u) a fishing rod using the fishing line of Comparative Example 8 as its leader line. As in Test (4), five testers alternated between fishing rods (q) to (u) every hour. Furthermore, each tester was moved from one location to another so that the same tester was not fixed to the same place (fishing seat) on the boat. The fishing lines of Examples 8 and 9 and those of Comparative Examples 6 and 8 were chosen because they have the same diameter (0.44 mm).

[0070] Table 9 shows the number of yellowtail caught and the number of fish other than yellowtail caught using the fishing lines of the Example and Comparative Example. The fish other than yellowtail were sea bream and yellowtail. Fish with a body length of 80 cm or more were defined as yellowtail, and those with a body length of less than 80 cm were defined as yellowtail.

[0071]

[0072] <Test (8)> On April 9, 2023, we conducted dragonfly jigging from a boat off the coast of Daiozaki, Shima City, Mie Prefecture. Two anglers were testers, and the time was six hours from 7:00 AM to 1:00 PM. Dragonfly jigging is a fishing method similar to the jigging described above, in which several meters of leader line are 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 it is a fishing method that mainly targets albacore tuna (the same applies below).

[0073] In this test (8), an ultra-high molecular weight polyethylene line with a diameter of 0.34 mm was used as the main line, and the length of the leader line was 7.5 m. (v) A fishing rod using the fishing line of Example 10 as the leader line and (w) A fishing rod using the fishing line of Comparative Example 9 as the leader line were prepared. As in <Test (4)>, two testers fished by switching between the fishing rods (v) and (w) every hour. Furthermore, each tester was moved between positions so that the same tester was not fixed to the same location (fishing seat) on the boat. The fishing line of Example 10 and the fishing line of Comparative Example 9 were chosen because they have the same diameter (0.72 mm).

[0074] Table 10 shows the number of albacore tuna caught and the number of fish other than albacore tuna caught using the fishing lines of the example and the comparative example. The fish other than albacore tuna were bonito.

[0075]

[0076] <Test (9)> On January 22, 2023, dragonfly jigging was conducted from a boat off the coast of Oshima, Kushimoto-cho, Higashimuro-gun, Wakayama Prefecture. Two testers were involved in the experiment, which lasted six hours from 7:00 AM to 1:00 PM. In this test (9), an ultra-high molecular weight polyethylene line with a diameter of 0.34 mm was used as the main line, and the length of the leader line was 7.5 m. (x) A fishing rod using the fishing line of Example 11 as the leader line, and (y) A fishing rod using the fishing line of Comparative Example 10 as the leader line were prepared. As in <Test (4)>, the two testers fished by switching between the fishing rods (x) and (y) every hour. In addition, the locations of each tester were moved relative to each other so that the same tester was not fixed to the same location (fishing seat) on the boat. The reason for choosing the fishing line of Example 11 and the fishing line of Comparative Example 10 is that they have the same diameter (1.02 mm).

[0077] Table 11 shows the number of albacore tuna caught and the number of fish other than albacore tuna caught using the fishing lines of the Examples and Comparative Examples. The fish other than albacore tuna were blue marlin.

[0078]

[0079] 1. Fishing line

Claims

1. A fishing line containing a colorant and having a spectral transmittance of 13% to 40% in the wavelength range of 425 nm to 575 nm.

2. The fishing line according to claim 1, wherein the spectral transmittance has a maximum value and a minimum value in the wavelength range of 425 nm to 575 nm, and the difference between the maximum value and the minimum value of the spectral transmittance is within 13%.

3. The fishing line according to claim 1, wherein there are multiple peaks of the spectral transmittance in the wavelength range of 425 nm to 575 nm.

4. The fishing line according to claim 1, which has a spectral reflectance of 26% or less in the wavelength range of 425 nm to 700 nm.

5. The fishing line according to claim 1, which is made of a monofilament containing said colorant and a polyvinylidene fluoride resin.

Images