Fishing line and preparation method thereof

Abstract

The present invention provides a fishing line and a method for preparing the same. The fishing line comprises a core layer, an intermediate layer, and a cladding layer. The core layer is LCP multifilament, and a woven structure is formed by weaving composite fiber filaments formed by coupling agent-modified tungsten carbide powder and polyamide resin. The cladding layer is LCP. The fishing line has extremely low water absorption, and both knot strength and knot strength retention meet excellent standards. The fishing line has extremely low water absorption, maintains knot strength after wetting, and exhibits good tensile strength, reducing the risk of the fishing line breaking, improving the reliability of the fishing line during use, and extending its service life.

Description

Technical Field

[0001] The present invention relates to the technical field of fishing gear processing, in particular to a fishing line and a preparation method thereof. Background Art

[0002] With the rapid development of deep-sea fishing and competitive sea fishing, fishing line, a key consumable, has become increasingly popular, with its performance directly impacting fishing efficiency and success rate. Existing sea fishing lines are primarily made from materials such as polyethylene (PE), nylon (PA), and fluorocarbon. However, in practice, achieving both knot strength retention and water absorption is a common challenge, hindering the development of high-value-added fishing lines.

[0003] For example, mainstream PE, made from twisted and woven ultra-high molecular weight polyethylene fibers, offers high strength and low water absorption (<0.1%). However, the smooth fiber surface results in only 50–60% knot strength retention (patent US20180223456A1), making it susceptible to breakage at the knot during frequent hooking or deep-sea dragging. While nylon line has been modified to increase knot strength to 70–80% (patent JP2021014502A), it absorbs a high amount of water (2–3%) and expands in diameter by 5–8% after prolonged immersion, leading to brittleness and decreased sensitivity. Fluorocarbon line, while boasting high density and rapid water shedding (patent CN112779750A), exhibits less than 60% knot strength due to its high hardness.

[0004] Existing technologies attempt to mitigate this conflict through coatings or composite structures. For example, patent KR102345678B1 proposes applying a silicone coating to the surface of PE lines to enhance knot strength. However, after the coating peels off, water absorption increases dramatically, resulting in insufficient durability. Patent WO202112344A1 utilizes a nylon-PE composite core-sheath structure, which, while limiting water absorption to less than 1.5%, still maintains knot strength below 65%. Furthermore, while the high twisting process (patent CN113293535A) enhances fiber cohesion, it also increases line rigidity, impacting casting controllability.

[0005] Therefore, developing a fishing line structure with both high knot strength retention and low water absorption has become a key direction to break through the existing technological barriers. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a fishing line and a preparation method thereof, so as to solve the problems in the prior art.

[0007] To achieve the above-mentioned purpose and other related purposes, the present invention is achieved through the following technical solutions.

[0008] The present invention provides a fishing line, comprising a core layer, an intermediate layer and a covering layer, wherein the core layer is LCP multifilament, the woven structure is formed by weaving composite fiber filaments formed by coupling agent-modified tungsten carbide powder and polyamide resin, and the covering layer is LCP.

[0009] Preferably, the particle size of the tungsten carbide powder is no greater than 5 μm. More preferably, the particle size of the tungsten carbide powder is 1 nm to 5 μm. For example, the particle size may be 1 nm to 1 μm, 1 to 2 μm, 2 to 3 μm, 3 to 4 μm, 4 to 4.5 μm, or 4.5 to 5 μm.

[0010] Preferably, the melting temperature of LCP is 280-350°C.

[0011] Preferably, the LCP is a thermotropic liquid crystal polymer.

[0012] More preferably, the LCP is Vectra A series LCP with a grade of 950.

[0013] Preferably, the number average molecular weight of the polyamide resin is 6,000-50,000.

[0014] Preferably, the glass transition temperature of the polyamide resin is greater than 30°C. More preferably, the glass transition temperature of the polyamide resin is greater than 30°C and less than 200°C.

[0015] Preferably, the polyamide resin is selected from one or more of polyamide 46, polyamide 66 and polyamide 610.

[0016] Preferably, the LCP multifilament is obtained by twisting LCP monofilament, and the twist is 20-50 T / m.

[0017] More preferably, the fineness of the LCP monofilament is 25-200 denier, such as 25-50 denier, 50-100 denier, 100-130 denier, 130-150 denier, or 150-200 denier.

[0018] Preferably, the coupling agent-modified tungsten carbide powder is obtained by the following method: soaking the tungsten carbide powder in a coupling agent solution at 20-40° C. and pH 4-5 for 2-3 hours.

[0019] More preferably, the concentration of the coupling agent solvent is 0.1-2.0 wt %.

[0020] More preferably, hydrochloric acid and / or acetic acid are used to adjust the pH of the coupling agent solution.

[0021] More preferably, the tungsten carbide powder is dried after the soaking treatment, with the drying temperature being 110-120° C. and the drying time being 20-30 min.

[0022] Preferably, the coupling agent is selected from one or more of dodecyltrimethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane and propyltrimethoxysilane.

[0023] Preferably, in the fishing line, the LCP content is 60-80 wt%, the polyamide resin content is 15-35 wt%, and the tungsten carbide powder content is 2-5 wt%. For example, the LCP content may be 60-63 wt%, 65-70 wt%, 70-75 wt%, or 77-80 wt%, the polyamide resin content may be 15-20 wt%, 25-30 wt%, or 30-35 wt%, and the tungsten carbide powder content may be 2-3 wt%, 3-4 wt%, or 4-5 wt%.

[0024] Preferably, the mass of the LCP in the core layer accounts for 30-50% of the total mass of the LCP, and the mass of the LCP in the cladding layer accounts for 50-70% of the total mass of the LCP. For example, the mass of the LCP in the core layer accounts for 30-35%, 35-40%, 40-45%, or 45-50% of the total mass of the LCP, and the mass of the LCP in the cladding layer accounts for 50-55%, 55-60%, 60-65%, or 65-70% of the total mass of the LCP.

[0025] Preferably, the diameter of the core layer is 0.50-0.80 mm.

[0026] Preferably, the thickness of the intermediate layer is 0.07-0.12 mm.

[0027] Preferably, the coating layer has a thickness of 0.10-0.20 mm. The coating layer thickness does not include the portion that penetrates into the intermediate layer, and is only the thickness from the upper surface of the intermediate layer to the upper surface of the coating layer.

[0028] Preferably, the diameter of the fishing line is 1.0-1.4 mm.

[0029] Preferably, the fishing line comprises one or more of the following features:

[0030] a) Water absorption rate less than 0.05%; b) Knot strength greater than 13 cN / dtex; c) Tensile strength greater than 15 cN / dtex; d) Density 1.4-1.8 g / cm 3 ; e) The water shear rate is 0.2~0.35m / s; f) The nodule strength retention rate is 75~85%.

[0031] The present invention also provides a method for preparing the above-mentioned fishing line, comprising the following steps:

[0032] 1) obtaining the LCP multifilament as the core layer by twisting the LCP monofilament;

[0033] 2) extruding the coupling agent-modified tungsten carbide powder and the polyamide resin through a twin-screw extruder, granulating, and melt-spinning the granules to obtain composite fiber filaments; and braiding the composite fiber filaments around the LCP multifilaments to form an intermediate layer of a braided structure;

[0034] 3) Melting the LCP and coating the outer layer, and cooling to obtain the fishing line.

[0035] Preferably, in step 1), the twisting process includes twisting, shaping and winding.

[0036] More preferably, the twisting process parameters include one or more of the following: twist 20-50 T / m, twisting temperature: 170-180°C, twisting tension: 10-20 cN, twist direction: Z twist, heat setting temperature of 260-280°C, and heat setting time of 30-120 s.

[0037] Preferably, the aspect ratio of the twin-screw extruder is 28-35.

[0038] Preferably, the screw speed of the twin-screw extruder is 5-50 rpm.

[0039] Preferably, the temperature of zone 1 of the twin-screw extruder is 270-285°C, the temperature of zone 2 is 290-310°C, and the temperature of zone 3 is 310-320°C.

[0040] Preferably, the melt spinning is a process in which the particles are melt-extruded and filtered, the melt is transported to a spinning manifold, extruded from spinnerets of a spinning plate, and cooled to form.

[0041] More preferably, the pellets are melt-extruded using a single-screw extruder.

[0042] Further preferably, the temperature of the feeding zone of the single-screw extruder is 275-285°C, the temperature of the melting zone is 285-305°C, and the temperature of the compression zone is 310-320°C.

[0043] More preferably, the screw speed of the single-screw extruder is 5-50 rpm.

[0044] Further preferably, the screw aspect ratio of the single-screw extruder is 28-35.

[0045] More preferably, the filter mesh size is 60 to 500. If the filter mesh size is less than 60, gel substances or impurities may easily clog the spinneret holes, and if the filter mesh size is greater than 500, the pressure before the filter may be too high.

[0046] More preferably, the spinning box temperature is 150-350°C.

[0047] More preferably, the spinning temperature is 310-350°C.

[0048] More preferably, the spinning pressure is 20-30 MPa.

[0049] More preferably, the metering pump pressure is 20-30 MPa.

[0050] More preferably, the diameter of the spinneret hole is 0.05-0.17 mm.

[0051] More preferably, the aspect ratio of the spinneret holes is 1-15, preferably 4-10.

[0052] More preferably, the spinneret holes are circular holes.

[0053] More preferably, the spinning speed is 400-1500 r / min.

[0054] More preferably, the cooling method is air cooling.

[0055] More preferably, the temperature is cooled to 50-100°C.

[0056] More preferably, after cooling and forming, stretching, oiling and winding are performed.

[0057] More preferably, the drafting ratio is 3 to 4 times.

[0058] More preferably, the oiling rate is 0.4-0.6%.

[0059] More preferably, the winding rate is 400-500 m / min.

[0060] Preferably, the molten LCP is injected into the inner diameter of the mold to cover the filament product comprising the core layer and the intermediate layer in the inner diameter.

[0061] More preferably, the melting temperature is 310-330°C.

[0062] More preferably, the diameter d of the outlet end of the die is 0.6-1.0 mm.

[0063] Preferably, the cooling is to room temperature, and the cooling method is air cooling.

[0064] Preferably, cooling is followed by annealing.

[0065] The fishing line in this application adopts a three-layer structure, with LCP monofilament as the core and tightly wound braided layers, which increases the overall strength and weight. The outer layer is then covered with an LCP layer with an anti-slip effect, which improves the strength and waterproofness of the fishing line and also increases the bonding strength between the core layer and the middle layer. The three-layer structure complements and cooperates with each other, improving the strength and water-cutting ability of the fishing line, while also making the fishing line have extremely low water absorption.

[0066] The combined effect of the three-layer structure makes the structure of the fishing line more stable. Compared with the fishing line with a single structure, this multi-layer fishing line can share the stress between the layers when subjected to external force, thereby reducing the structural damage caused by excessive local force and ensuring the stability of the fishing line during use.

[0067] The present invention provides a fishing line and a preparation method thereof, which have the following beneficial effects:

[0068] 1. The fishing line has an extremely low water absorption rate, and both the knot strength and knot strength retention rate reach good indicators;

[0069] 2. The fishing line has an extremely low water absorption rate, and the knot strength does not decrease after being soaked. It also has good tensile strength, which reduces the risk of the fishing line being broken, improves the reliability of the fishing line during use, and extends the service life of the fishing line;

[0070] 3. The fishing line has excellent water-cutting properties, allowing the fishing rig to sink quickly to the target depth and keep the fishing rig stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 Shown is a cross-section of the mold.

[0072] d is Figure 1 The diameter of the outlet end of the middle die. DETAILED DESCRIPTION

[0073] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0074] Before further describing the specific embodiments of the present invention, it should be understood that the scope of the present invention is not limited to the specific embodiments described below. It should also be understood that the terminology used in the examples is intended to describe specific embodiments and is not intended to limit the scope of the present invention. The experimental procedures in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0075] When the embodiments provide numerical ranges, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range and any numerical value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those generally understood by those skilled in the art. In addition to the specific methods, equipment, and materials used in the embodiments, according to the understanding of the prior art by those skilled in the art and the description of the present invention, any methods, equipment, and materials of the prior art similar or equivalent to the methods, equipment, and materials described in the embodiments of the present invention may also be used to implement the present invention.

[0076] The following raw materials are used in the examples and comparative examples of this application:

[0077] The particle size of tungsten carbide powder is 4.5 μm, and the particle size is detected by SEM;

[0078] The coupling agent is dodecyltrimethoxysilane;

[0079] The brand of LCP is Vectra A950 (manufacturer: Celanese Corporation), and the melting temperature is 280° C. The melting temperature is measured by DSC.

[0080] The polyamide resin is polyamide 66, manufactured by Asahi Kasei under the brand name Leona 66, with a number average molecular weight of 18,000 and a Tg of 65°C. The number average molecular weight is determined by gel permeation chromatography (GPC). The Tg is determined by DCS.

[0081] The fineness of LCP monofilament is 50 denier, purchased from Ningbo HiKolar New Material Technology Co., Ltd., model number is YoKolar-HT.

[0082] Example 1

[0083] This embodiment provides a fishing line, including a core layer, an intermediate layer and a cladding layer. The core layer is LCP multifilament, the intermediate layer is a braided structure formed by tungsten carbide powder and polyamide resin, and the cladding layer is an LCP layer.

[0084] The fishing line contains 63wt% LCP, 35wt% polyamide resin, and 2wt% tungsten carbide powder. The LCP in the core layer accounts for 30% of the total LCP mass, while the LCP in the cladding layer accounts for 70% of the total LCP mass.

[0085] The diameter of the fishing line is 1.06 mm, the diameter of the core layer is 0.50 mm, the thickness of the middle layer is 0.12 mm, and the thickness of the coating layer is 0.16 mm.

[0086] This embodiment also provides a method for preparing the above-mentioned fishing line, comprising the following specific steps:

[0087] (1) Preparation of LCP multifilament:

[0088] The LCP monofilament was unwound, twisted in a two-for-one twister, and then fed into a setting machine where it was cooled to room temperature. The twist was 20 T / m, twisting temperature was 170°C, twisting tension was 15 cN, twist direction was Z, heat setting temperature was 280°C, and heat setting time was 120 seconds.

[0089] (2) Preparation of the middle layer of the woven structure:

[0090] 1) Preparation of composite fiber filaments:

[0091] The tungsten carbide powder was washed and dried, and then immersed in a dodecyltrimethoxysilane solution (concentration: 2.0 wt %) at 30° C. and pH 4 for 3 hours, and then dried at 110° C. for 30 minutes.

[0092] The modified tungsten carbide powder and polyamide resin were mixed, melt-extruded, and granulated in a twin-screw extruder to produce pellets. The twin-screw extruder had an aspect ratio of 30 and a screw speed of 40 rpm. The temperatures in zone 1, zone 2, and zone 3 were 280°C, 300°C, and 320°C, respectively. The pellets were cylindrical and 6 mm long.

[0093] The granules are melted and extruded through a single-screw extruder, and the melt flows into a spinning box. The melt flow rate is controlled by a metering pump. The melt enters a spinneret after being filtered, and is extruded through the spinneret holes on the spinneret to form a melt stream. The melt is then air-cooled to 50°C, stretched, oiled, and wound to obtain composite fiber filaments.

[0094] Melt-spinning process parameters for pellets: single-screw extruder, aspect ratio: 30, screw speed: 40 rpm. Feed zone temperature: 280°C, melt zone temperature: 300°C, compression zone temperature: 310°C. Single-screw extruder speed: 40 rpm, aspect ratio: 30. Spinning box temperature: 200°C, metering pump pressure: 30 MPa, filter mesh: 100 mesh, spinning temperature: 310°C, spinning pressure: 30 MPa, spinneret speed: 1000 rpm, spinneret orifice aspect ratio: 10, spinneret orifice diameter: 0.09 mm, round. Draft ratio: 3. Oiling rate: 0.4%, white oil used. Winding speed: 400 m / min.

[0095] 2) Preparation of braided structure: The composite fiber filaments are braided on the surface of the LCP monofilament using a braiding machine to obtain braided fiber filaments.

[0096] Weaving process parameters: mesh count: 120 mesh / inch, pitch: 1.693 mm, weaving angle: 96.142°, weaving method: 1 press 2. 1 press 2, that is, one fiber will press over two adjacent fibers in sequence. This structure can form a relatively tight woven layer with higher strength and stability.

[0097] (3) Fishing line preparation: The LCP was melted and injected into the inner diameter of the mold to coat the filament product containing the core layer and the intermediate layer in the inner diameter, and then naturally cooled to room temperature and annealed. The melting temperature was 310°C, and the diameter d of the die outlet was 0.16 mm.

[0098] Example 2

[0099] This embodiment provides a fishing line, which is basically the same as the first embodiment, except that:

[0100] The fishing line comprises 80 wt% LCP, 15 wt% polyamide resin, and 5 wt% tungsten carbide powder. The LCP in the core layer accounts for 50% of the total LCP mass, and the LCP in the cladding layer accounts for 50% of the total LCP mass.

[0101] The diameter of the fishing line is 1.19 mm, the diameter of the core layer is 0.77 mm, the thickness of the middle layer is 0.07 mm, and the thickness of the coating layer is 0.14 mm.

[0102] This embodiment also provides a method for preparing the above-mentioned fishing line, which is substantially the same as that of Example 1, except that: in step (1), the twist is 45 T / m; in step (2), the diameter of the spinning hole is 0.05 mm; and in step (3), the diameter d of the die outlet is 0.14 mm.

[0103] Example 3

[0104] This embodiment provides a fishing line, which is basically the same as the first embodiment, except that:

[0105] The fishing line contains 77wt% LCP, 20wt% polyamide resin, and 3wt% tungsten carbide powder. The LCP in the core layer accounts for 40% of the total LCP mass, while the LCP in the cladding layer accounts for 60% of the total LCP mass.

[0106] The diameter of the fishing line is 1.01 mm, the diameter of the core layer is 0.57 mm, the thickness of the middle layer is 0.08 mm, and the thickness of the coating layer is 0.14 mm.

[0107] This embodiment also provides a method for preparing the above-mentioned fishing line, which is the same as that of Example 1, except that: in step (1), the twist is 30 T / m; in step (2), the diameter of the spinning hole is 0.06 mm; and in step (3), the diameter d of the die outlet is 0.14 mm.

[0108] Comparative Example 1

[0109] This comparative example is a comparative example of Example 3, and differs from Example 3 only in that:

[0110] In the fishing line, the content of polyamide resin is 10wt% and the content of LCP is 87wt%.

[0111] The diameter of the fishing line is 1.1 mm, the diameter of the core layer is 0.72 mm, the thickness of the middle layer is 0.06 mm, and the thickness of the coating layer is 0.19 mm.

[0112] The method for preparing the fishing line is substantially the same as that of Example 1, except that: in step (1), the twist is 40 T / m; in step (2), the diameter of the spinning hole is 0.05 mm; and in step (3), the diameter d of the die outlet is 0.19 mm.

[0113] Comparative Example 2

[0114] This comparative example is a comparative example of Example 3, and differs from Example 3 only in that:

[0115] In the fishing line, the content of polyamide resin is 40wt% and the content of LCP is 57wt%.

[0116] The diameter of the fishing line is 1.04 mm, the diameter of the core layer is 0.54 mm, the thickness of the middle layer is 0.13 mm, and the thickness of the coating layer is 0.12 mm.

[0117] The method for preparing the fishing line is substantially the same as that of Example 1, except that in step (1), the twist is 29 T / m. In step (2), the diameter of the spinning hole is 0.1 mm. In step (3), the diameter d of the die outlet is 0.12 mm.

[0118] Comparative Example 3

[0119] This comparative example is a comparative example of Example 3, and differs from Example 3 only in that:

[0120] The mass percentages of the LCP in the core layer and the cladding layer account for 75% and 25% of the total mass of the LCP respectively.

[0121] The diameter of the fishing line is 1.07 mm, the diameter of the core layer is 0.43 mm, the thickness of the middle layer is 0.11 mm, and the thickness of the coating layer is 0.21 mm.

[0122] The method for preparing the fishing line is substantially the same as that of Example 1, except that in step (1), the twist is 11 T / m. In step (2), the diameter of the spinning hole is 0.08 mm. In step (3), the diameter d of the die outlet is 0.21 mm.

[0123] Comparative Example 4

[0124] This comparative example is a comparative example of Example 3, and differs from Example 3 only in that:

[0125] The mass percentages of the LCP in the core layer and the cladding layer account for 90% and 10% of the total mass of the LCP respectively.

[0126] The diameter of the fishing line is 1.08 mm, the diameter of the core layer is 0.72 mm, the thickness of the middle layer is 0.07 mm, and the thickness of the coating layer is 0.11 mm.

[0127] The method for preparing the fishing line is substantially the same as that of Example 1, except that: in step (1), the twist is 40 T / m; in step (2), the diameter of the spinning hole is 0.05 mm; and in step (3), the diameter d of the die outlet is 0.11 mm.

[0128] Comparative Example 5

[0129] This comparative example is a comparative example of Example 3, differing from Example 3 only in that the fishing line includes a core layer and an intermediate layer, wherein the core layer is an LCP multifilament and the intermediate layer is a braided structure formed of tungsten carbide powder and polyamide resin. The mass percentage of the LCP in the core layer and the cladding layer relative to the total mass of the LCP is 100% and 0%, respectively.

[0130] The diameter of the fishing line is 1.08mm, the diameter of the core layer is 1.41mm, and the thickness of the middle layer is 0.04mm.

[0131] The method for preparing the fishing line is substantially the same as that of Example 1, except that: step (3) is not included; in step (1), the twist is 10 T / m; and in step (2), the diameter of the spinning hole is 0.03 mm.

[0132] Table 1

[0133] Tungsten carbide powder content (%) Polyamide resin content (%) Total LCP content (%) The proportion of LCP in the core layer to the total mass of LCP (%) The proportion of LCP in the coating layer to the total mass of LCP (%) Example 1 2 35 63 30 70 Example 2 5 15 80 50 50 Example 3 3 20 77 40 60 Comparative Example 1 3 10 87 40 60 Comparative Example 2 3 40 57 40 60 Comparative Example 3 3 20 77 25 75 Comparative Example 4 3 20 77 55 45 Comparative Example 5 3 20 77 77 0

[0134] The following performance tests were performed on the fishing lines prepared in Examples 1 to 3 and Comparative Examples 1 to 5. The test methods are as follows. The test results are shown in Table 2.

[0135] The knot strength of a fishing line refers to the maximum tensile force that the knot can withstand after the line is tied. It reflects the reliability of the fishing line when connecting hooks, bait, and other equipment in actual use. Test method: ASTM D7269 is used to test the knot using an FG knot, ensuring that the knot is tightened and there is no noticeable looseness. The test was conducted at a tensile speed of 300 mm / min, a line length of 200 mm, and an ambient temperature and humidity of 23°C and 65% RH.

[0136] Tensile Strength: Tested using ASTM D2256. Ambient temperature and humidity: 23°C, 65% RH, fishing line length: 200 mm, tensile speed: 300 mm / min.

[0137] Water shedding performance: This test measures water shedding rate. The test steps are as follows: 1) Secure the upper end of the fishing line to a line clip, hang a 2g weight from the lower end, and align the lower end of the line with the zero mark on the water surface, ensuring it is vertical and free of bends. 2) Instantly release the line using the electromagnetic release mechanism, while simultaneously activating a high-speed camera to record the time it takes for the lower end of the line to sink to 50cm. 3) Repeat this five times, taking the average value as the final water shedding time, t, and calculating the water shedding rate. Water shedding rate = 50cm / water shedding time. The test environment is a water tank at 20°C and a depth of 1m. The water is allowed to stand until the water flow is completely still.

[0138] Water absorption: ASTM D570 test was used, the immersion temperature was 23°C, and the immersion time was 24 hours.

[0139] Density: Use the following method: immerse the fishing line in water, record the volume V caused by the water level rise, use a balance to measure the mass m of the fishing line, and calculate the density using the formula ρ = m / V.

[0140] Table 2

[0141] <![CDATA[Density (g / cm 3 ).]]> Diameter of fishing line (mm) Water cutting rate (m / s) Water absorption rate (%) Tensile strength (cN / dtex) Nodule strength (cN / dtex) Nodule strength retention rate / % Example 1 1.40 1.06 0.23 0.03 18 13.5 75 Example 2 1.78 1.19 0.30 0.04 23.2 18.6 80.2 Example 3 1.58 1.01 0.27 0.04 21.8 17.0 78.0 Comparative Example 1 1.62 1.1 0.27 0.03 20 8.7 43.5 Comparative Example 2 1.52 1.04 0.26 0.05 13 9.1 70 Comparative Example 3 1.57 1.07 0.26 0.03 10.4 7.8 75 Comparative Example 4 1.59 1.08 0.27 0.05 16 9.5 59.4 Comparative Example 5 1.60 1.08 0.27 1.21 11.2 4.1 36.6

[0142] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A fishing line, characterized in that: The fishing line comprises a core layer, an intermediate layer and a cladding layer, wherein the core layer is LCP multifilament, the intermediate layer is a woven structure formed by weaving composite fiber filaments formed by coupling agent-modified tungsten carbide powder and polyamide resin, and the cladding layer is LCP. In the fishing line, the content of LCP is 60-80wt%, the content of polyamide resin is 15-35wt%, and the content of tungsten carbide powder is 2-5wt%. The mass of LCP in the core layer accounts for 30-50% of the total mass of LCP, and the mass of LCP in the cladding layer accounts for 50-70% of the total mass of LCP. The knot strength of the fishing line is greater than 13 cN / dtex.

2. The fishing line according to claim 1, wherein The particle size of tungsten carbide powder is not greater than 5μm; and / or, the melting temperature of the LCP is 280-350°C; and / or, LCP is a thermotropic liquid crystal polymer; And / or, the number average molecular weight of the polyamide resin is 6000-50000; and / or, the glass transition temperature of the polyamide resin is greater than 30° C.; And / or, the polyamide resin is selected from one or more of polyamide 46, polyamide 66 and polyamide 610; and / or, the LCP multifilament is obtained by twisting LCP monofilament, with a twist of 20–50 T / m; And / or, the coupling agent-modified tungsten carbide powder is obtained by the following method: soaking the tungsten carbide powder in a coupling agent solution at 20-40° C. and pH 4-5 for 2-3 hours; And / or, the coupling agent is selected from one or more of dodecyltrimethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane and propyltrimethoxysilane.

3. The fishing line according to claim 2, wherein: The LCP is Vectra A series LCP with a grade of 950; and / or the concentration of the coupling agent solvent is 0.1-2.0 wt %; and / or the fineness of the LCP monofilament is 25 denier-200 denier.

4. The fishing line according to claim 1, wherein The diameter of the core layer is 0.50-0.80 mm; And / or, the thickness of the intermediate layer is 0.07-0.12 mm; And / or, the coating layer has a thickness of 0.10 to 0.20 mm; And / or, the diameter of the fishing line is 1.0-1.4 mm.

5. The fishing line according to claim 1, wherein The fishing line has one or more of the following characteristics: a) a water absorption rate of less than 0.05%; b) a tensile strength of greater than 15 cN / dtex; c) a density of 1.4-1.8 g / cm 3 ; d) water shear rate is 0.2~0.35m / s; e) nodule strength retention rate is 75~85%.

6. A method for preparing a fishing line according to any one of claims 1 to 5, characterized in that: The steps include: 1) obtaining the LCP multifilament as the core layer by twisting the LCP monofilament; 2) extruding the coupling agent-modified tungsten carbide powder and the polyamide resin through a twin-screw extruder, granulating, and melt-spinning the granules to obtain composite fiber filaments; and braiding the composite fiber filaments around the LCP multifilaments to form an intermediate layer of a braided structure; 3) Melting the LCP and coating the outer layer, and cooling to obtain the fishing line.

7. The preparation method according to claim 6, characterized in that The aspect ratio of the twin-screw extruder is 28~35; and / or, the screw speed of the twin-screw extruder is 5 to 50 rpm; And / or, the temperature of zone 1 of the twin-screw extruder is 270-285°C, the temperature of zone 2 is 290-310°C, and the temperature of zone 3 is 310-320°C; And / or, the melt spinning is that the granular material is melt-extruded and filtered, and the melt is transported to a spinning manifold, extruded from the spinneret holes of a spinning plate, and cooled to form; And / or, the molten LCP is injected into the inner diameter of the mold to cover the filament product comprising the core layer and the middle layer in the inner diameter.

8. The preparation method according to claim 7, characterized in that The granular material is melt-extruded using a single-screw extruder; and / or, the filter mesh size is 60-500 mesh; and / or, the spinning box temperature is 150-350°C; and / or, the spinning temperature is 310-350° C.; and / or, the spinning pressure is 20-30 MPa; and / or, the metering pump pressure is 20~30 MPa; and / or, the spinneret hole has a diameter of 0.05 to 0.17 mm; and / or, the spinneret hole has an aspect ratio of 1 to 15; and / or, the spinning speed is 400-1500 r / min; and / or, the cooling method is air cooling; and / or, cooling to 50-100° C.; and / or, after cooling and forming, stretching, heat setting, oiling and winding; and / or, in step 3), the melting temperature is 310-330°C; And / or, in step 3), the diameter d of the outlet end of the mold is 0.6-1.0 mm.

9. The preparation method according to claim 8, characterized in that The temperature of the feeding zone of the single-screw extruder is 275-285°C, the temperature of the melting zone is 285-305°C, and the temperature of the compression zone is 310-320°C; And / or, the screw speed of the single-screw extruder is 5-50 rpm; And / or, the screw aspect ratio of the single-screw extruder is 28-35; And / or, the draft ratio is 3 to 4 times.

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