A fishing line, fishing line monofilament, and method for producing the same

Abstract

A monofilament fishing line, a multifilament fishing line, and method for producing the same are provided. The multifilament fishing line may contain a braided or twisted article containing a plurality of monofilaments that are braided or twisted. The monofilament fishing line and the multifilament fishing line may each include a monofilament containing a liquid crystal polymer (LCP). The LCP may be formed from a reaction selected from the group consisting of (i) a polycondensation reaction between aromatic hydroxycarboxylic acids; and (ii) a polycondensation reaction between an aromatic hydroxy carboxylic acid and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aliphatic carboxylic acids, aromatic hydroxyamines, aromatic diamines, aromatic diols, and aliphatic diols. The monofilament fishing line and the multifilament fishing line may each have a knot strength ranging from 500 MPa to 1500 MPa and 500 to 2,000 MPa, respectively.

Description

PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1A FISHING LINE, FISHING LINE MONOFILAMENT, AND METHOD FOR PRODUCING THE SAMECROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims benefit to U.S. Provisional Application No. 63 / 695,926 filed on September 18, 2024. The entire contents this application is incorporated herein by reference in its entirety.BACKGROUND

[0002] Fluoropolymers such as poly vinylidene fluoride are a major component for conventional fishing lines. Fluorochemicals are also used as an additive to be coated or mixed to enhance mechanical performance of fishing lines. Key requirements for fishing lines are high abrasion resistance, knot strength, elongation, etc., and such fluorinated compounds as mentioned above play great roles to achieve those properties.

[0003] On the other hand, per- and polyfluoroalkyl substances (“PFAS”) are attracting global attention. Of particular note are compounds referred to as “specific PFAS,” such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). These specific PFAS are known to be highly persistent, bio-accumulative, and toxic to humans. Specific PFAS are already regulated in many countries, with their manufacture and use being prohibited. Fluorinated compounds used in conventional fishing lines are also broadly classified as PFAS, raising concerns about potential future regulations. Therefore, there is a demand for fishing lines that use sustainable materials free of fluorinated compounds while still satisfying physical property requirementsSUMMARY

[0004] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0005] In one aspect, embodiments disclosed herein relate to a monofilament fishing line. The monofilament fishing line may include a single monofilament. The single monofilament may contain a liquid crystal polymer formed from a reaction selected from the group consisting of (i) a polycondensation reaction between aromatic hydroxycarboxylic acids; and (ii) a polycondensation reaction between an aromatic hydroxy carboxylic acid and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aliphatic carboxylic acids, aromatic hydroxyamines, aromatic diamines, aromatic diols, and aliphatic diols. The monofilament fishing line may have a knot strength in a range of 500 MPa to 1500 MPa.

[0006] In another aspect, embodiments disclosed herein relate to a multifilament fishing line. The multifilament fishing line may contain a braided or twisted article containing a plurality of monofilaments braided or twisted to form the braided or twisted article. The plurality of monofilaments may contain a liquid crystal polymer formed from a reaction selected from the group consisting of (i) a polycondensation reaction between one or more aromatic hydroxycarboxylic acids; and (ii) a polycondensation reaction between an aromatic hydroxycarboxylic acid and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aliphatic carboxylic acids, aromatic hydroxyamines, aromatic diamines, aromatic diols, and aliphatic diols. The multifilament fishing line may have a knot strength ranging from 500 to 2,000 MPa.

[0007] In yet another aspect, embodiments disclosed herein relate to a method of producing a monofilament fishing line that includes polymerizing monomers to form a liquid crystal polymer; melting the liquid crystal polymer to form a molten liquid crystal polymer; extruding the molten liquid crystal polymer to form an extruded liquid crystal polymer; drawing the extruded liquid crystal polymer to form the monofilament having a diameter ranging from 10 to 800 pm; and braiding or twisting the monofilament to form the multifilament fishing line. The monomers are selected from the group consisting of (i) one or more aromatic hydroxycarboxylic acids; and (ii) an aromatic hydroxycarboxylic acid and at least one comonomer selected from the group consisting of aromaticPATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 dicarboxylic acids, aliphatic dicarboxylic acids, aromatic hydroxyamines, aromatic diamines, aromatic diols, and aliphatic diols.

[0008] Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.BRIEF DESCRIPTION OF DRAWINGS

[0009] FIG. 1 shows a monofilament fishing line in accordance with one or more embodiments.

[0010] FIGs. 2A-2B are examples of Scanning Electron Microscope (“SEM”) images of a cross sectional view of a liquid crystal polymer monofilament in accordance with one or more embodiments.

[0011] FIG. 3 shows an example of a multifilament fishing line in accordance with one or more embodiments.

[0012] FIG. 4 is a schematic illustration of a braid angle of the multifilament fishing line in accordance with one or more embodiments.

[0013] FIG. 5 shows an example of a multifilament fishing line in accordance with one or more embodiments.

[0014] FIGs. 6A-6B show examples of multifilament fishing lines in accordance with one or more embodiments.

[0015] FIG. 7 shows a block flow diagram of a method of producing a monofilament fishing line in accordance with one or more embodiments.

[0016] FIG. 8 shows a block flow diagram of a method of producing a multifilament fishing line in accordance with one or more embodiments.

[0017] FIGs. 9A-9B are digital microscope images of the LCP monofilament fishing line in accordance with one or more embodiments and a commercial LCP monofilament fishing line respectively.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0018] FIG. 10 shows a digital microscope image of coated LCP monofilament fishing line in accordance with one or more embodiments and a commercial LCP monofilament fishing line respectively.

[0019] FIG. 11 shows a graph of Young’s modulus of LCP monofilament fishing lines prepared by different process conditions in accordance with one or more embodiments.

[0020] FIG. 12 shows results of the tensile strain vs tensile stress of fishing lines in accordance with one or more embodiments.DETAILED DESCRIPTION

[0021] The present disclosure generally relates to a monofilament fishing line, a multifilament fishing line (which is a braided structure), and method for producing the same. The monofilament fishing line contains a single monofilament containing a liquid crystal polymer (“LCP”). The multifilament fishing line contains a plurality of monofilaments braided to form a braided article, wherein the monofilaments contain a LCP. The fishing lines described herein have mechanical properties suitable for use in fishing lines and also do not contain PF AS. Thus, the fishing lines described herein are a useful alternative to conventional fishing lines.Liquid Crystal Polymer

[0022] As noted above, the present disclosure relates to a monofilament that includes a LCP. LCP contains mesogens which are molecules derived from aromatic compounds. Mesogens have some degree of directionality which is referred to as “anisotropy” and are structured as rigid rods. Because of the mesogens, LCPs may have a nematic phase, smectic phase, or cholesteric phase. In one or more embodiments, the LCP disclosed herein may have a nematic phase.

[0023] In one or more embodiments, the LCP may be an aromatic polyester formed from a reaction between aromatic hydroxycarboxylic acids, or a reaction between an aromatic hydroxycarboxylic acid and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aromatic diols, and aliphatic diols. Examples of chemical structures of LCPs are shown in formulas (I)-(III) below.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0024] In a non-limiting example, the reaction between aromatic hydroxycarboxylic acids may result in a product that includes a structure of formula (II). The reaction between aromatic hydroxycarboxylic acid and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aromatic diols, and aliphatic diols may result in a product that includes a structure of formula (I) and / or formula (III). As a non-limiting example, the reaction between an aromatic hydroxycarboxylic acid, an aromatic diol, and an aromatic dicarboxylic acid may result in a product that includes a structure of formula (I). In another non-limiting example, a reaction between an aromatic hydroxycarboxylic acid, an aliphatic diol, and an aromatic dicarboxylic acid may result in a product that includes a structure of formula (III).

[0025] Specifically, in one or more embodiments, the LCP may contain repeating units formed from a condensation polymerization reaction between aromatic hydroxycarboxylic acid monomers, or a condensation polymerization reaction between an aromatic hydroxycarboxylic acid monomer and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aromatic diols, and aliphatic diols. For example, the polymer structure may involve functional groups called “Mers” which refers to a repeating unit, and are polymerized in a long chain by either addition or condensation polymerization into a long polymer chain. The LCP may have an end cap group at one or more ends. The end cap group may be a group known to those skilled in the art.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0026] Examples of aromatic hydroxycarboxylic acids may include, but are not limited to, 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 6-hydroxy-2- naphthoic acid, and halogen-, alkyl-, or allyl-substituted derivatives of hydroxybenzoic acid.

[0027] Examples of aromatic dicarboxylic acids may include, but are not limited to, terephthalic acid, isophthalic acid, 3, 3 ’-diphenyl dicarboxylic acid, 4,4’ -diphenyl dicarboxylic acid, 1 ,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, and alkyl- or halogen-substituted aromatic dicarboxylic acids such as t-butylterephthalic acid, and chloroterephthalic acid.

[0028] Examples of aliphatic dicarboxylic acids may include, but are not limited to, cyclic aliphatic dicarboxylic acids such as trans- 1,4-cy cl ohexane dicarboxylic acid, cis- 1,4- cyclohexane dicarboxylic acid, 1,3 -cyclohexane dicarboxylic acid, and substituted derivatives thereof.

[0029] Examples of aromatic diols may include, but are not limited to, hydroquinone, biphenol, 4,4’-dihydroxydiphenyl ether, 3, 4 ’-dihydroxy diphenyl ether, bisphenol A, 3,4’- dihydroxydiphenylmethane, 3,3’ -dihydroxy diphenylmethane, 4,4 ’ -dihydroxydiphe- nylsulfone, 3,4’-dihydroxydiphenylsulfone, 4,4’ -dihydroxy diphenylsulfide, 3,4’- dihydroxdiphenylsulfide; 2,6’ -naphthalenediol; 1,6' dihydroxy benzophenone, 3,4’- dihydroxybenzophenone, 3,3’ -dihydroxybenzophenone, 4,4’ -dihydroxy diphenyldimethylsilane, and alkyl- and halogen-substituted derivatives thereof.

[0030] Examples of aliphatic diols may include, but are not limited to, cyclic, linear, and branched aliphatic dials such as trans- 1,4-hexanediol, cis-l,4-hexanediol, trans- 1,3- cyclohexanediol, cis-l,2-cyclohexanediol; ethylene glycol, 1 ,4-butanediol, 1,6-hexane- diol, 1,8-octanediol, trans- 1,4-cy cl ohexanedimethanol, cis-l,4-cyclohexanedimethanol, and substituted derivatives thereof.

[0031] In one or more embodiments, a molar ratio between aromatic hydroxycarboxylic acid monomers is in a range from 80:20 to 70:30. The molar ratio between aromatic hydroxy carboxylic acid monomers is in a range having a lower limit of any one of 80:20, 79:21, 78:22, 77:23, 76:24, and 75:25 and an upper limit of any one of 75:25, 74:26,PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO173:27, 72:28, 71:29, and 70:30, where any lower limit can be paired with any mathematically compatible upper limit. The molar ratio may be adjusted based on the desired temperature performance and desired viscosity of the LCP.

[0032] In one or more embodiments, a molar ratio between the aromatic hydroxycarboxylic acid monomer(s) and the at least one comonomer is in a range from 100:0 to 70:30. The molar ratio between an aromatic hydroxycarboxylic acid monomer and at least one comonomer is in a range having a lower limit of any one of 100:0, 95:5, 90: 10, 85: 15, 80:20, 79:21, 78:22, 77:23, 76:24, and 75:25 and an upper limit of any one of 85: 15, 83:17, 80:20, 78:22, 75:25, 74:26, 73:27, 72:28, 71 :29, and 70:30, where any lower limit can be paired with any mathematically compatible upper limit.

[0033] Alternatively, in one or more embodiments, the LCP may be an aromatic polyester amide formed from a reaction between an aromatic hydroxy carboxylic acid; at least one comonomer selected from the group consisting of aromatic dicarboxylic acids and aliphatic dicarboxylic acids; at least one comonomer selected from the group consisting of aromatic hydroxyamines and aromatic diamines; and / or at least one optional comonomer selected from the group consisting of aromatic diols and aliphatic diols. Specifically, in one or more embodiments, the LCP may contain repeating units formed from a condensation polymerization reaction between a hydroxycarboxylic acid monomer and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids and aliphatic dicarboxylic acids; at least one comonomer selected from the group consisting of aromatic hydroxyamines, and aromatic diamines; and at least one optional comonomer selected from the group consisting of aromatic diols and aliphatic diols.

[0034] Examples of aromatic hydroxyamines may include, but are not limited to, 4- aminophenol, 3 -aminophenol, and substituted derivatives thereof.

[0035] Examples of aromatic diamines may include, but are not limited to, p- phenylenediamine, m-phenylenediamine, and substituted derivatives thereof.

[0036] The LCP may have a molecular weight ranging from 5,400 Daltons (“Da”) to 17,000 Da. In one or more embodiments, the molecular weight of LCP may have a lowerPATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 limit of one of 5,400, 5,600, 5,800, 6,000, 6,500, 7,000, 7,500, 8,000, 9,000, 10,000, 11,000 and 12,000 Da, and an upper limit of one of 11,000, 12,000, 13,000, 14,000, 15,000, 15,500, 16,000, 16,200, 16,400, 16,600, 16,800, and 17,000 Da, where any lower limit may be paired with any upper limit.Fishing Line

[0037] Fishing lines are typically categorized into monofilament and multifilament in the view of filament structures. Monofilament fishing lines may be used for fishing in freshwater, inshore, near shore, or off a pier. Meanwhile, a multifilament fishing line is formed from a plurality of monofilaments braided together and may be used during saltwater game fishing. Conventional fishing lines may contain fluoropolymers such as polyvinylidene fluoride (PVDF). However, fluoropolymers may be restricted by environmental regulation agencies as a PFAS in the future, which necessitates the use of alternative materials to fluoropolymers. In one or more embodiments, the fishing lines described herein are substantially free of fluoropolymers and contain the LCP described above.A Monofilament Fishing Line

[0038] In one or more embodiments, a monofilament fishing line contains a single monofilament. The single monofilament contains the LCP as described above.

[0039] FIG. 1 is a schematic drawing of a monofilament fishing line 10, in accordance with one or more embodiments. Alternatively, in one or more embodiments, the monofilament fishing line may be coated with various coatings, as will be explained in subsequent sections. As shown in FIG.1, the monofilament fishing line contains a single monofilament. While the monofilament is shown with a circular cross-section, any cross- sectional shape may be used.

[0040] As shown in FIG. 1, the monofilament fishing line 10 may have a diameter do, which may range from 20 to 800 pm (micrometers). In one or more embodiments, the diameter do of the monofilament fishing line may have a lower limit of one of 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, and 450 pm, and an upper limit of one of 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700,PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1720, 730, 740, 750, 760, 770, 780, 790, and 800 pm, where any lower limit may be paired with any upper limit. As a non-limiting example, a monofilament of one or more embodiments may have a diameter do in a range from 20 to 60 pm.

[0041] A monofilament fishing line may be used as mainline and leader line. A main line is wrapped around a reel of a fishing rod and a leader line is a section of the fishing line that is between a hook and the main line. The monofilament fishing line requires moderate sensitivity and impact resistance. Thus, the LCP monofilament fishing line of one or more embodiments of the present disclosure may have the following properties.

[0042] The monofilament fishing line may have a knot strength ranging from 500 MPa (MegaPascals) to 2100 MPa. In one or more embodiments, the knot strength of the monofilament fishing line may have a lower limit of one of 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, and 1200 MPa, and an upper limit of one of 600, 700, 750, 800, 850, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, and 2100 MPa, where any lower limit may be paired with any upper limit. As a non-limiting example, the monofilament has a knot strength ranging from 700 MPa to 2000 MPa, such as from 1000 MPa to 2000 MPa.

[0043] The monofilament fishing line may have a knot elongation ranging from 4% to 30%. In one or more embodiments, the knot elongation of the monofilament fishing line may have a lower limit of one of 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, and 20%, and an upper limit of one of 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, and 30%, where any lower limit may be paired with any upper limit.

[0044] The knot strength and knot elongation are measured based on Japanese Industrial Standards (“JIS”) L 1013 by making a knot with the monofilament, except that the gauge length is 150 mm and the tensile rate is 150 mm / min (millimeters per minute). The maximum stress is taken as the knot strength and the elongation at break is taken as the knot elongation. The measurement results of the knot strength and knot elongation are each obtained by calculating the average value of 5 measurements (n=5).

[0045] The monofilament fishing line may have a tensile strength ranging from 700 MPa to 3,100 MPa. In one or more embodiments, the tensile strength of the monofilamentPATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 fishing line may have a lower limit of one of 700, 720, 740, 760, 780, 800, 850, 900, 1,000, 1,100, 1,200, 1,300, and 1,400 MPa, and an upper limit of one of 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, 2,000, 2,200, 2,400, 2,600, 2,800, 3,000, and 3,100 MPa, where any lower limit may be paired with any upper limit. As a non-limiting example, a monofilament of one or more embodiments may have a tensile strength ranging from 2200 MPa to 3000 MPa.

[0046] The monofilament fishing line may have a tensile elongation ranging from 4% to 30%. In one or more embodiments, the tensile elongation of the monofilament fishing line may have a lower limit of one of 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, and 20%, and an upper limit of one of 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, and 30%, where any lower limit may be paired with any upper limit.

[0047] The tensile strength and tensile elongation are measured based on Japanese Industrial Standards (“JIS”) L 1013 without making a knot with the monofilament, except that the gauge length is 150 mm and the tensile rate is 150 mm / min. The maximum stress is taken as the tensile strength and the elongation at break is taken as tensile elongation. The measurement results of the tensile strength and tensile elongation are each obtained by calculating the average value of 5 measurements (n=5).

[0048] The monofilament fishing line may have a Young’s modulus ranging from 1 GPa (GigaPascals) to 120 GPa. In one or more embodiments, the Young’s modulus of the monofilament fishing line may have a lower limit of one of 1, 1.5, 2, 2.2, 2.4, 2.6, 2.8, 3, 4, 5, 10, 20, 30, 40, 50, and 60 GPa, and an upper limit of one of 2.4, 2.6, 2.8, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, and 120 GPa, where any lower limit may be paired with any upper limit. In the present disclosure, the Young’s modulus refers to a slope of stress-strain curve between 90 MPa and 100 MPa. As a non-limiting example, a monofilament of one or more embodiments may have a Young’s modulus ranging from 50 GPa to 100 GPa

[0049] The monofilament fishing line may have wet abrasion cycle in a range of 200 times to 2100 times. In one or more embodiments, the wet abrasion cycle of the monofilament fishing line may have a lower limit of one of 200, 250, 300, 400, 500, 600, 700, 800, 900,PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 and 1000 times, and an upper limit of one of 300, 400, 500, 600, 800, 900, 1000, 1100, 1300, 1500, 1700, 1900, 2000, and 2100 times, where any lower limit may be paired with any upper limit. As a non-limiting example, a monofilament in accordance with one or more embodiments may have a wet abrasion cycle of at least 500 times, such as in a range from 500 to 2000 times.

[0050] In the present disclosure, the “wet abrasion” of the monofilament fishing line refers to a number of cycles that the monofilament is rubbed until the monofilament fishing line breaks. Specifically, a wet filament is moved back and forth repeatedly in the direction of the monofilament axis while contacting the sandpaper #1000 (JIS R6001) spread on a drum, in the circumferential direction of the drum. The drum has a diameter of 190 mm (millimeters). The reciprocating cycle of the monofilament is 26 times / min (times per minute), and the reciprocating width is 55 mm. The weight per filament cross-sectional area loaded on the monofilament is 10.5 kg / mm2(kilograms per millimeter squared). A constant flow of water (10 mL / min, milliliters per minute) is pumped continuously to the monofilament to keep the monofilament wet throughout the wet abrasion measurement.

[0051] In one or more embodiments, the monofilament fishing line may have dry abrasion cycle of 200 times or more, such as 500 times or more, 800 times or more, or 1000 times or more. In the present disclosure, the “dry abrasion” of the monofilament fishing line refers to a number of cycles that the monofilament is rubbed until the monofilament fishing line breaks. The dry abrasion is measured in a similar method to that of the wet abrasion described above, except that there is no water flow during the measurement.

[0052] The monofilament fishing line may be inert to most liquids and may absorb 0.04 wt% or less based on the total weight of the monofilament fishing line, such as 0.03 wt% or less, 0.02 wt% or less, or 0.01 wt% or less, of water.

[0053] The monofilament fishing line may have a friction coefficient ranging from 0.1 to 3.86. In one or more embodiments, the friction coefficient of the monofilament fishing line may have a lower limit of one of 0.1, 0.25, 0.50, 0.75, 0.90, 0.95, 1.00, 1.05, 1.10, 1.20, 1.40, 1.60, 1.80, 2.00, 2.20, 2.40, 2.60, and 2.80, and an upper limit of one of 2.40,PATENT APPLICATION ATTORNEY DOCKET NO. 18984-015WO12.60, 2.80, 3.00, 3.20, 3.40, 3.60, 3.65, 3.70, 3.75, 3.80, and 3.86, where any lower limit may be paired with any upper limit.

[0054] The friction coefficient of the monofilament fishing line is evaluated based on American Society for Testing and Materials (“ASTM”) DI 894-11, “Standard Test Method for Static and Kinetic Coefficients of Friction of Plastic Film” and “Sheeting 1.”

[0055] Conventional LCPs typically suffer from poor abrasion resistance due to a “skin layer” that forms on the surface of the polymer. Upon abrasion the skin layer breaks up into tiny fibrils, which deteriorates the filament. Thus, minimizing the skin layer of the LCP of the present disclosure is critical to achieving properties necessary for use as a fishing line. The monofilament fishing line may have a skin layer thickness of 500 nm (nanometers) or less, such as 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less. As a non-limiting example, the monofilament of one or more embodiments includes a skin layer that has a thickness of 500 nm or less.

[0056] The skin layer of the monofilament fishing line is measured by cross-sectioning the monofilament with focused ion beam (“FIB”) and imaging the skin layer using a scanning electron microscope (“SEM”). FIGs. 2A-2B are examples of SEM images of the cross section of the LCP monofilament. Specifically, FIG. 2B is an enlarged SEM image of the SEM image of FIG. 2A to show the skin layer of the LCP monofilament. As shown in FIG. 2B, 12 data points (Pal - Pa6 and Pa R1 - Pa R6) are obtained to measure the thickness in nanometers (“nm”) of the skin layer. The thickness of the skin layer between each data point is measured, as shown in Table 1 below. Thus, SEM can be used to measure the thickness of any skin layer on an LCP monofilament.

[0057] Table 1. Thickness of the skin layer between data points Pal - Pa6 and Pa R1 - Pa R6.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0058] The skin layer may have a Young’s modulus of 5.0 GPa or less, such as 4.0 GPa or less, 3.0 GPa or less, 2.0 GPa or less, or 1.0 GPa or less, in order to enhance the knot strength of the fishing line. In a non-limiting example, the monofilament of one or more embodiments includes a skin layer may that has a Young’s modulus of 1.0 GPa or less. The Young’s modulus of the skin layer may be measured by a nanoindentation measurement method. The nanoindentation measurement method is a depth-sensing technique used to characterize mechanical properties, such as hardness and elastic modulus at the nanoscale. The procedure utilizes a precision instrument equipped with a diamond indenter (e.g., Berkovich or spherical) of known geometry, along with high- resolution sensors for load and displacement, which is often operated within a vibration- isolated and temperature-controlled environment.

[0059] The measurement process for nanoindentation may include an approach phase where the indenter contacts the fiber surface, followed by a loading phase in which a controlled force is applied to induce penetration. An optional hold segment at peak load may be used to assess time- dependent deformation or correct for thermal drift. During unloading, the elastic recovery of the material is recorded, generating a loaddisplacement curve. Mechanical properties are then extracted from this curve. For example, hardness can be calculated as the peak load divided by the projected contact area, while the reduced elastic modulus (Er) is derived from the slope of the unloading curve as shown in Equation (1), below.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0060] In Equation (1), S is the stiffness that relates to the slope of the unloading curve; and A is the projected contact area.

[0061] The Young’s modulus of the skin layer is then determined by correcting for the indenter’s elastic properties using established contact mechanics equations, such as Equation (2), below.

[0062] In Equation (2), v refers to Poisson’s ratio of the sample; E is the Young’s modulus of the skin layer; Vi refers to Poisson’s ratio of the indenter; and Ei is the elastic modulus of the indenter, which is typically a diamond material.

[0063] Advanced modes such as a Continuous Stiffness Measurement (CSM) and / or spatial mapping may be employed for depth-dependent or heterogeneous surface analysis.A Multifilament Fishing Line

[0064] In one or more embodiments, a multifilament fishing line is a braided article containing a plurality of monofilaments braided to form the braided article. The plurality of monofilaments constituting the braided article may be the monofilament as discussed above, but are not particularly limited, as long as the desired physical properties of the braided article are achieved. For example, the monofilaments of the braided article may have physical properties (e.g. tensile strength, tensile elongation, knot strength, knot elongation, Young's modulus, wet abrasion cycle, and friction coefficient) that are equivalent to the physical properties when braided as described below. By combining a plurality of filaments, the best features of each respective material may improve the overall performance of the multifilament fishing line.

[0065] FIG. 3 shows an example of a multifilament fishing line, containing a braided structure formed from six monofilaments in accordance with one or more embodiments. In FIG. 3, the multifilament fishing line 300 includes six monofilaments 310, 320, 330, 340, 350, and 360 that are braided together along the longitudinal direction of thePATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 multifilament fishing line 300. By combining a plurality of filaments, the best features of a plurality of materials may improve the overall performance of the multifilament fishing line 300.

[0066] While FIG. 3 shows six single monofilaments 310, 320, 330, 340, 350, and 360, any number greater than one may be used. The braided article in fishing line 300 may be interwoven to form any braid structure (e.g., diamond, regular, and hercules) or ordered in any combination (e.g., braid sequence / complexity).

[0067] The braided structure of the multifilament fishing line can be customized by varying the number of strands, the braiding angle, and the materials used. In one or more embodiments, the multifilament fishing line may be coated with various coatings, as will be explained in subsequent sections.

[0068] The braided article may have a carrier count ranging from 4 to 54. In one or more embodiments, the carrier count of the braided article may have a lower limit of one of 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 25, 30, 35, and 40 and an upper limit of one of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 22, 24, 25, 28, 30, 32, 35, 38, 40, 42, 45, 48, 50, 52, and 54, where any lower limit may be paired with any upper limit. The “carrier count” of the present disclosure is a commonly known phrase by a person of ordinary skill in the art and refers to a number of strands braided to form the multifilament fishing line.

[0069] The braided article may have picks per inch (“PPI”) ranging from 2 to 12. In one or more embodiments, the PPI of the braided article may have a lower limit of one of 2, 3, 4, 5, 6, 7, 8, and 9, and an upper limit of one of 5, 6, 7, 8, 9, 10, 11, and 12, where any lower limit may be paired with any upper limit. The “PPI” of the present disclosure is a commonly known phrase by a person of ordinary skill in the art and refers to a number of times the carriers cross each other in a weaving process to form the multifilament fishing line.

[0070] The braided article may have a braiding angle ranging from 10 degrees to 75 degrees. In one or more embodiments, the braiding angle of the braided article may have a lower limit of one of 10, 11, 12, 13, 14,15, 20, 25, 30, 40, 50, 60, and 70 degrees and an upper limit of one of 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 71, 72, 73, 74, and 75PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 degrees, where any lower limit may be paired with any upper limit. FIG. 4 is a schematic illustration of the braid angle in accordance with one or more embodiments. As shown in FIG. 4, the braid angle 0 in the present disclosure is the angle between the braid axis 402 and bias direction 404 made by crossing filaments 406 in the braid 400.

[0071] The braided article may have a fineness ranging from 60 to 2000 dtex (deci-tex, or grams per 10000 meters of line). In one or more embodiments, the fineness of the braided article may have a lower limit of one of 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, 1,000, 1,100, and 1,200 dtex, and an upper limit of one of 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,650, 1,700, 1,750, 1,800, 1,850, 1,900, 1,950, 1,960, 1,970, 1,980, 1,990, and 2,000 dtex, where any lower limit may be paired with any upper limit. In the present disclosure, the “fineness” refers to a calculated weight of the 50 m of a braided article multiplied by 200.

[0072] A multifilament fishing line may be used as a mainline which is wrapped around a reel of a fishing rod. The multifilament fishing line requires outstanding sensitivity. Thus, the LCP multifilament fishing line of one or more embodiments of the present disclosure may have the following properties.

[0073] The multifilament fishing line may have a knot strength ranging from 500 MPa to 2, 100 MPa. In one or more embodiments, the knot strength of the multifilament fishing line may have a lower limit of one of 500, 600, 700, 800, 900, 1,000, 1,020, 1,040, 1,060, 1,080, 1,100, 1,150, 1,200, 1,250, 1,300, 1,400, 1,500, and 1,600, MPa, and an upper limit of one of 1,300, 1,400, 1,500, 1,600, 1,700, 1,750, 1,800, 1,850, 1,900, 1,920, 1,940, 1,960, 1,980, 2,000, and 2,100 MPa, where any lower limit may be paired with any upper limit. As a non-limiting example, the multifilament fishing line may have a knot strength ranging from 800 MPa to 2000 MPa, such as from 1000 MPa to 2000 MPa.

[0074] The multifilament fishing line may have a knot elongation ranging from 1 % to 6 %. In one or more embodiments, the knot elongation of the multifilament fishing line may have a lower limit of one of 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0%, and an upper limit of one of 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO13.0, 3.5, 4.0, 4.5, 5.0, 5.5, and 6.0%, where any lower limit may be paired with any upper limit.

[0075] In one or more embodiments, the knot strength and knot elongation of the multifilament fishing line are measured as discussed above. A cross-sectional area of the braided article (for the purposes of determining knot strength and knot elongation, or other properties described below) is calculated by multiplying the cross-sectional area of the monofilaments by the number of monofilaments constituting the braided article.

[0076] The multifilament fishing line may have a tensile strength ranging from 1 ,400 MPa to 3,100 MPa. In one or more embodiments, the tensile strength of the multifilament fishing line may have a lower limit of one of 1,400, 1,420, 1,440, 1,460, 1,480, 1,500, 1,520, 1540, 1,560, 1,580, 1,600, 1,650, 1,700, 1,750, 1,800, 1,850, 1,900, 1,950, 2,000, 2,100, 2,200, 2,300, and 2,400 MPa, and an upper limit of one of 2,000, 2,100, 2,200, 2,300, 2,400, 2,450, 2,500, 2,550, 2,600, 2,650, 2,700, 2,750, 2,800, 2,820, 2,840, 2,860, 2,880, 2,900, 2,920, 2,940, 2,960, 2,980, 3,000 and 3,100 MPa, where any lower limit may be paired with any upper limit. As a non-limiting example, the multifilament fishing line of one or more embodiments may have a tensile strength ranging from 2200 MPa to 3000 MPa.

[0077] The multifilament fishing line may have a tensile elongation ranging from 1.8% to 6.0%. In one or more embodiments, the tensile elongation of the multifilament fishing line may have a lower limit of one of 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, and 2.7%, and an upper limit of one of 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 4.0, 4.5, 5.0, 5.5, and 6.0%, where any lower limit may be paired with any upper limit. The tensile strength and tensile elongation of the multifilament fishing line are measured as discussed above.

[0078] The multifilament fishing line may have a Young’s modulus of greater than 30 GPa, such as greater than 40 GPa, greater than 50 GPa, or greater than 60 GPa. In the present disclosure, the Young’s modulus refers to a slope of stress-strain curve between 900 MPa and 1000 MPa. Young’s modulus relates to bending stiffness of the fiber and therefore, modifying to the above range may improve the knot strength of the fishing line. As a non-PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 limiting example, the multifilament fishing line of one or more embodiments may have a Young’s modulus of at least 50 GPa.

[0079] The multifilament fishing line may have wet abrasion cycle in a range of 400 times to 2,000 times. In one or more embodiments, the wet abrasion cycle of the multifilament fishing line may have a lower limit of one of 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1,000, 1,100, 1,200, and 1,300 times, and an upper limit of one of 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900 and 2,000 times, where any lower limit may be paired with any upper limit. The wet abrasion test is as described above. As a non-limiting example, a multifilament fishing line in accordance with one or more embodiments may have a wet abrasion cycle of at least 500 times, such as in a range from 500 times to 2,000 times.

[0080] The multifilament fishing line may be inert to most liquids and may absorb 0.04 wt% or less based on the total weight of the multifilament fishing line, such as 0.03 wt% or less, 0.02 wt% or less, or 0.01 wt% or less, of water.

[0081] The multifilament fishing line may have a friction coefficient ranging from 0.1 to 3.86. In one or more embodiments, the friction coefficient of the multifilament fishing line may have a lower limit of any one of 0.10, 0.12, 0.14, 0.16, 0.18. 0.20, 0.22, 0.24, 0.30, 0.50, 0.70, 0.90, 1.00, 1.50, and 2.00, and an upper limit of any one of 1.50, 2.00, 2.50, 3.00, 3.50, 3.70, 3.72, 3.74, 3.76, 3.78, 3.80, 3.82, 3.84, and 3.86, where any lower limit may be paired with any upper limit. In one or more embodiments, the friction coefficient is measured as discussed above.

[0082] In one or more embodiments, the braided structure is formed over a core filament so that the fishing line has a core-sheath structure containing a plurality of filaments braided over the core filament. The core filament may be a single monofilament, a bundle of multiple monofilaments or a yarn having the braided structure as discussed above as long as the desired physical properties are achieved. One or more embodiments, the coresheath structure contains a core filament having the braided structure and a sheath formed of the braided structure, so called “double braid.” FIG. 5 shows the core-sheath structure containing the braided core 501 covered with the braided sheath 502.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0083] In one or more embodiments, the braided structure is formed by braiding multiple monofilaments or multifilament bundles, such as 6, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44 and 48 ends. The multiple monofilaments may be divided into a plurality of bundles according to the carrier count. The plurality of bundles may be twisted together within each bundle. The plurality of bundles may be braided together. Each bundle may be formed from one or more twisted threads. The number of twisted threads constituting each bundle may be 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, or 9 or more threads. The threads may be the same or different between each bundle. The number of monofilaments constituting each twisted thread may be 3 or more, 4 or more, 5 or more, or 6 or more. The braided article may have one type of monofilament or multitude of different monofilaments. The braid structure may be round, flat, or a hybrid of a round and flat structure.

[0084] As a non-limiting example, the multifilament fishing line may be formed of a braid of multiple bundles, each consisting of one or more strands of individual filaments (monofilaments). Each bundle may include a plurality of monofilaments that can be twisted together. For example, each bundle may be formed from two or more but eight or less (e.g., 7 or less, 6 or less, 5 or less, or 4 or less) strands of three monofilaments. In each bundle, the monofilaments may be twisted together. Alternatively, each strand may be formed from at least one monofilament as a core with two or more cover filaments twisted around the core. The diameter of each monofilament, tensile strength of each monofilament, knot strength of each monofilament, Young’s modulus of each monofilament, wet abrasion cycle of each monofilament, and / or skin layer of each monofilament may be as described previously (e.g., as described for a monofilament fishing line).

[0085] Alternatively, in one or more embodiments, a multifilament fishing line is a twisted article containing a plurality of monofilaments twisted together to form the twisted article. The plurality of monofilaments constituting the twisted article may be the monofilament as discussed above, but are not particularly limited, as long as the same desired physical properties as described for the braided article are achieved.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0086] FIGs. 6A-6B each show a multifilament fishing line, containing a twisted structure in accordance with one or more embodiments. In FIG. 6A, the multifilament fishing line 600A includes a monofilament 610 as a core part monofilament and a plurality of sheath part monofilaments 620a-f that are twisted along the longitudinal direction of the multifilament fishing line 600 A. By combining a plurality of filaments, the best features of a plurality of materials may improve the overall performance of the multifilament fishing line 600 A.

[0087] In one or more embodiments, the multifilament fishing line 600A includes a plurality of identical sheath filaments (i.e., 620a-f are the same material, diameters de20a-f are the same), a plurality of unique sheath filaments (i.e., diameters de20a-f are different and / or composition of 620a-f are different), or any combination thereof (e.g., multiple instances of one or more different sheath filaments).

[0088] While a circular cross-sectional shape of diameter deio and de20a-f are shown, any cross-sectional shape, diameter, and / or dimensional measure may be used for the monofilaments 610 and 620a-f. Furthermore, while the monofilament 610 and monofilament 620a-f are shown in roughly equal size (drawings are not to scale), any relative ratio of the filament diameter (or appropriate dimension) may be used. Furthermore, while FIG. 6A shows six unique sheath monofilaments 620a-f as an example, any number greater than one may be used.

[0089] In one or more embodiments, the plurality of sheath monofilaments 620a-f may be radially distributed around the main monofilament 610. For example, the plurality of sheath filaments 620a-f may completely surround the main monofilament 610 in a coresheath geometry along the longitudinal direction of the fishing line. The plurality of sheath monofilaments 620a-f may be distributed in a symmetrical or asymmetrical arrangement about the main monofilament 610. The multifilament fishing line 600A may be characterized by major and minor axis diameters (e.g., deA-i and deA-2, respectively) or an effective diameter of the twisted filaments.

[0090] Alternatively, the multifilament fishing line may have no main monofilament, and have multiple monofilaments twisted together to form a multifilament fishing line. FIG.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO16B shows a multifilament fishing line 600B in accordance with one or more embodiments. As shown in FIG. 6B, the multifilament fishing line 600B has no main monofilament and includes monofilaments 620a-f twisted together to form a multifilament fishing line 600B. The multifilament fishing line 600B may be characterized by major and minor axis diameters (e.g., deB-i and deB-2, respectively) or an effective diameter of the twisted filaments.

[0091] While a circular cross-sectional shape of diameter de20a-f are shown, any cross- sectional shape, diameter, and / or dimensional measure may be used for the monofilaments 620a-f. Furthermore, while the monofilaments 620a-f are shown in roughly equal size (drawings are not to scale), any relative ratio of the filament diameter (or appropriate dimension) may be used. Furthermore, while FIG. 6B shows six unique monofilaments 620a-f as an example, any number greater than one may be used.A Method for Producing a Monofilament Fishing Line

[0092] In one aspect, embodiments disclosed herein relate to a method of producing a monofilament fishing line. The method may include polymerizing aromatic hydroxy carboxylic acids, and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aromatic diols, and aliphatic diols to form a LCP. Alternatively, in one or more embodiments, the method may include polymerizing aromatic hydroxycarboxylic acids, and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aromatic diols, and aliphatic diols, aliphatic carboxylic acids, aromatic hydroxyamines, and aromatic diamines to form a LCP.

[0093] In one or more embodiments, the method may further include melting the LCP to form a molten LCP; extruding the molten LCP to form an extruded LCP; and drawing the extruded LCP to form the monofilament fishing line.

[0094] In one or more embodiments, the polymerizing may include a condensation polymerization. The “condensation polymerization” of the present disclosure refers to a reaction in which monomers of hydroxycarboxylic acids, and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylicPATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 acids, aromatic diols, and aliphatic diols react to form a LCP while releasing by-products. The condensation polymerization may be melt polymerization, solution polymerization, or solid-phase polymerization.

[0095] In one or more embodiments, the polymerization may be produced in an inert gas atmosphere under anhydrous conditions. Examples of inert gas may include, but are not limited to, nitrogen and argon, among others.

[0096] Specifically, in one or more embodiments, the melt polymerization may be, for example, a melt acidolysis method. First, the hydroxy carboxy lie acids and aromatic dicarboxy lie acids may be mixed and heated at 300°C for 2 hours in a reaction vessel including a nitrogen introduction tube and a distillation head or cooler, and then stirred. Next, by-products, such as acetic acid, are collected and removed through the distillation head or cooler. After the quantity of collected by-products becomes constant, and the polymerization is almost completed, the melted lump may be heated under a vacuum (e.g. 10 mmHg or lower) and the remaining by-products are removed, thereby completing the polymerization.

[0097] Once the polymer is formed, it may then be extruded. In one or more embodiments, the extruding may be performed with an extruder. The extruder may be any type of extruder known to those skilled in the art to extrude the polymer. For example, a die of the extruder may have a diameter in a range of from about 100 pm to 500 pm. The temperature of extrusion may be in range of from about 280 °C to 360 °C. In one or more embodiments, the extrusion temperature may have a lower limit of one of 280, 282, 284, 286, 288, 290, 295, 300, 305, 310, 320, 330, and 340 °C, and an upper limit of one of 300, 310, 320, 330, 335, 340, 345, 350, 352, 354, 356, 358, and 360 °C, where any lower limit may be paired with any upper limit.

[0098] The extrusion may be performed with a speed in a range of from about 50 meters / minute (“m / min”) to 750 m / min. In one or more embodiments, the extrusion speed may have a lower limit of one of 50, 52, 54, 56, 58, 60, 65, 70, 75, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, and 500 m / min, and an upper limit of one of 300, 350, 400, 450,PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1500, 550, 600, 650, 700, 710, 720, 725, 730, 735, 740, 742, 744, 746, 748, and 750 m / min, where any lower limit may be paired with any upper limit.

[0099] After the extrusion, the extruded polymer may be quenched to a temperature ranging from -192 °C to 300 °C. In one or more embodiments, the quench temperature may have a lower limit of one of -192, -188, -186, -182, -178, -174, -170, -150, -130, - 110, -90, -70, -50, -30, -10, 0, 10, 30, 50, and 70°C, and an upper limit of one of 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 276, 280, 284, 288, 290, 292, 296, and 300°C, where any lower limit may be paired with any upper limit. The quench temperature may be in the above temperature range to adjust the mechanical properties and abrasion resistance of the monofilament.

[0100] Then, the extruded polymer may be drawn to form the monofilament. In one or more embodiments, the drawing of the extruded LCP may be performed with godet rolls, to obtain a monofilament fishing line. For example, after the extruded polymer exits the die, the extruded polymer may be wrapped around one or more godet rolls, through a non-contact diameter measurement, and then onto a winding mechanism. A closed loop winder speed control may be synced with the godet rolls speed and the extruder output to determine how the filament is drawn down in diameter, to determine the draw ratio (“DR”), and measure the final diameter of the monofilament. In the present disclosure, DR is defined as the ratio of the cross-sectional area of the die opening to the cross- sectional area of the final monofilament.

[0101] In one or more embodiments, DR may range from about 9 to 156, based on the diameter and desired mechanical properties of the of the monofilament fishing line. For example, DR may have a lower limit of one of 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, and 90, and an upper limit of one of 70, 80, 90, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 151, 152, 153, 154, 155, and 156, where any lower limit may be paired with any upper limit. Furthermore, the drawing speed may be in a range of from about 50 meters per minute (“m / min”) to 750 m / min. In one or more embodiments, the drawings speed may have a lower limit of one of 50, 52, 54, 56, 58, 60, 65, 70, 75, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, and 500 m / min, and an upperPATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 limit of one of 300, 350, 400, 450, 500, 550, 600, 650, 700, 710, 720, 725, 730, 735, 740, 742, 744, 746, 748, and 750 m / min, where any lower limit may be paired with any upper limit.

[0102] The monofilament fishing line obtained from the above described method may have a diameter ranging from 10 pm to 800 pm. In one or more embodiments, the diameter do of the monofilament fishing line may have a lower limit of one of 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, and 450 pm, and an upper limit of one of 25, 30, 35, 40, 50, 100, 200, 300, 400, 500, 600, 700, and 800 pm, where any lower limit may be paired with any upper limit.

[0103] FIG. 7 is a flow chart of a method of producing a monofilament fishing line, in accordance with one or more embodiments. At 700, a LCP is formed by polymerizing hydroxy carboxylic acids, and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aromatic diols, and aliphatic diols. At 720, the obtained LCP is melted to form a molten LCP. At 740, the molten LCP is extruded to form an extruded LCP. At 760, the extruded LCP is drawn to form the monofilament fishing line.

[0104] In one or more embodiments, the method may further include adding additives to the LCP to enhance the knot strength and / or abrasion resistance of the monofilament fishing line. For example, additives may be added to the LCP during the melting, during the extruding, and / or after the extruding such that the additives are attached to the surface of the LCP. Examples of additives may include, but are not limited to glycidyl epoxy, novolac epoxy, cycloaliphatic epoxy, aromatic epoxy, silane and combinations thereof. The additives may be added in an amount in a range from about 3 wt% (weight percent) to 7 wt% based on the amount of the LCP. For example, in one or more embodiments, the amount of additives may range from a lower limit of one of 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.6, 4.8, 5, 5.2, and 5.4 wt% of an upper limit of one of 4.6, 4.8, 5, 5.2, 5.4, 5.6, 5.8, 6, 6.2, 6.4, 6.6, 6.8, and 7.0 wt%, based on the amount of the LCP, where any lower limit may be paired with any mathematically compatible upper limit.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0105] In one or more embodiments, the method may further include coating the monofilament fishing line with coatings to enhance abrasion resistance of the monofilament fishing line. The coating may contain a lubricant to further enhance abrasion resistance. A non-limiting example of a lubricant is silicone. For example, the coatings may be applied to the monofilament fishing line by pulling the monofilament fishing line through a bath filled with coatings, and then pulling the monofilament fishing line through a die with an opening having a diameter greater than the diameter of the monofilament fishing line, such that the coatings are coated with appropriate thickness on the surface of the monofilament fishing line.

[0106] Examples of coatings may include, but are not limited to, siloxane, silicon carbide filled epoxy, and urethane. The coatings may be added in an amount in a range from about 0.5 wt% to 5 wt% based on the weight% of the monofilament fishing line. For example, in one or more embodiments, the amount of coatings may range from a lower limit of one of 0.5, 0.7, 0.9, 1, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8 and 3 wt% of an upper limit of one of 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.5, 4.6, 4.8, and 5 wt%, based on the amount of the monofilament fishing line, where any lower limit may be paired with any mathematically compatible upper limit.A Method for Producing a Multifilament Fishing Line

[0107] In one aspect, embodiments disclosed herein relate to a method of producing a multifilament fishing line. The method may include braiding the monofilament fishing line obtained from the method described above. Alternatively, the monofilaments used to make the braided articles may differ from the monofilament described above.

[0108] FIG. 8 is a flow chart of a method of producing a multifilament fishing line, in accordance with one or more embodiments. At 800, a LCP is formed by polymerizing aromatic hydroxycarboxylic acids, and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aromatic diols, and aliphatic diols. At 820, the obtained LCP is melted to form a molten LCP. At 840, the molten LCP is extruded to form an extruded LCP. At 860, the extruded LCP is drawnPATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 to form the monofilament fishing line. At 880, a plurality of monofilament fishing lines are braided to form the multifilament fishing line.

[0109] Specifically, in one or more embodiments, a plurality of monofilaments is twisted or braided together along the longitudinal direction of the multifilament fishing line. Any relative ratio of the filament diameter (or appropriate dimension) may be used. For example, a smaller monofilament may provide sufficient tensile strength to the fishing line while a larger monofilament may be provided to support the monofilament to provide the desired bending resistance to the multifilament fishing line. Alternatively, in one or more embodiments, a plurality of sheath monofilaments may be twisted or braided together over a core filament or yarn along the longitudinal direction of the multifilament fishing line. The multifilament fishing line may include a plurality of identical monofilaments, a plurality of unique monofilaments, or any combination thereof.

[0110] Braiding of the monofilaments to form a braided article in fishing line may be executed in any direction (e.g., clockwise or counterclockwise twisting / spinning / twist spinning) or ordered in any combination (e.g., braid sequence / complexity). The details of the braided article are discussed in the previous section.

[0111] In one or more embodiments, the method includes coating and / or impregnating the multifilament fishing line with a coating to enhance abrasion resistance of the multifilament fishing line. The coating and method of application may be similar to those described above for the monofilament fishing line, with the exception that the coating is applied to the multifilament fishing line. The coating may be applied to either the multifilament fishing line or at least one of the monofilaments constituting the multifilament fishing line.

[0112] Alternatively, in one or more embodiments, the coating is applied to both the multifilament fishing line and at least one of the monofilaments constituting the multifilament fishing line to achieve desirable physical properties for the multifilament fishing line. The coating applied to the multifilament fishing line may be the same as or different from the coating applied to the constituent monofilaments. For example, a coating for the monofilaments may be applied for the reduction in friction between thePATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 monofilaments and a braiding machine, while a coating for the multifilament fishing line may be applied to reduce friction between the lines. In such embodiments, the coating for the multifilament fishing line can be different from the coating used for the monofilaments.EXAMPLES

[0113] Abrasion Resistance Test 1

[0114] Abrasion resistance of a commercial LCP monofilament fishing line and an inventive LCP monofilament fishing line are evaluated. The abrasion test was conducted as described above.

[0115] An example of the inventive LCP monofilament fishing line was prepared by the method as described above. Specifically, the inventive LCP was obtained by reacting 4- hydroxybenzoic acid (HBA) monomers and 6-hydroxy-2-naphthoic acid (HNA) monomers with a molar ratio of 70:30.

[0116] A commercial LCP fiber was used to prepare a monofilament fishing line as a comparative example. Examples of commercially available LCP fiber include, but are not limited to, Vectran™ HT, NT, and UM (Kuraray Co., Ltd, Japan).

[0117] FIG. 9A shows a digital microscope image of the inventive LCP monofilament fishing line and FIG. 9B shows a digital microscope image of the commercial LCP monofilament fishing line. The digital microscope used to obtain the image are Olympus DSX1000 Microscope, DSX10-SXLOB Lens IX, Total Magnification 20X. The magnification of the digital microscope images is 10000 pm.

[0118] As shown in FIG. 9A, the inventive LCP monofilament fishing line does not show any fibrillation, indicating that the inventive LCP monofilament fishing line has high abrasion resistance. Meanwhile, the commercial LCP monofilament fishing line (FIG. 9B) shows fibrillation (i.e., a skin layer formed on the surface of the commercial LCP monofilament breaks up into tiny fibrils), indicating poor abrasion resistance.

[0119] Abrasion Resistance Test 2PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0120] Abrasion resistance of a commercial LCP monofilament fishing line and an inventive coated-LCP monofilament fishing line were evaluated. The abrasion test was conducted as described above.

[0121] An example of the inventive coated-LCP monofilament fishing line was prepared by the method as described above. Specifically, the inventive LCP was obtained by reacting 4-hydroxybenzoic acid (HBA) monomers and 6-hydroxy-2-naphthoic acid (HNA) monomers with a molar ratio of 70:30. The obtained LCP was coated with epoxy and silane, where the total amount of epoxy and silane was 3 wt. % based on the weight of the LCP monofilament fishing line.

[0122] FIG. 10 shows a digital microscope image of the coated LCP monofilament fishing line in accordance with one or more embodiments and a commercial LCP monofilament fishing line respectively. The digital microscope used to obtain the image are Olympus DSX1000 Microscope, DSX10-SXLOB Lens IX, Total Magnification 20X. The magnification of the digital microscope image is 10000 pm.

[0123] The inventive coated LCP monofilament fishing line is the lower fiber (marked as “1001”) shown in FIG. 10. The inventive coated LCP monofilament fishing line does not show any fibrillation, indicating that the inventive coated LCP monofilament fishing line has high abrasion resistance. The evaluation was concluded when it was determined that the inventive coated LCP monofilament fishing line could withstand at least 1000 cycles of wet abrasion and at least 17,156 cycles of dry abrasion. Meanwhile, the commercial LCP monofilament fishing line, which is the upper fiber marked as “1002” in FIG. 10 shows fibrillation, indicating poor abrasion resistance. The wet abrasion for the commercial LCP monofilament fishing line was determined to be 61 cycles.

[0124] Young’s Modulus

[0125] Young’s modulus of the inventive LCP monofilament fishing lines are evaluated. The Young’s modulus is measured as described above.

[0126] FIG. 11 is a graph showing Young’s modulus and also tensile stress and maximum force of examples of LCP monofilament fishing lines prepared by different processPATENT APPLICATION ATTORNEY DOCKET NO. 18984-015WO1 conditions. Example 1 is an inventive LCP monofilament fishing line having a diameter of 50 pm prepared with a 0.25 mm sized die, at a die temperature of 340 °C, a draw down ratio (“DDR”) of 25, a line speed of 200 M / min, and quenched with ice after extrusion. Example 2 is another inventive LCP monofilament fishing line having a diameter of 50 pm prepared with a 0.15 mm sized die, at a die temperature of 340 °C, a DDR of 9, a line speed of 200 M / min, and quenched with ice after extrusion. Example 3 is another inventive LCP monofilament fishing line having a diameter of 50 pm prepared with a 0.15 mm sized die, at a die temperature of 355 °C, a DDR of 9, a line speed of 200 M / min, and quenched with ice after extrusion. Example 4 is another inventive LCP monofilament fishing line having a diameter of 72 pm prepared with a 0.25 mm sized die, at a die temperature of 310 °C, a DDR of 12, a line speed of 150 M / min, and quenched with liquid nitrogen (“LN2”) after extrusion. The process conditions for each example are summarized in Table 2 below.

[0127] Table 2. Process Conditions of Examples of Inventive LCP Monofilament Fishing Lines

[0128] Table 3 shows the results of the Young’s modulus test of Examples 1-4.

[0129] Table 3. Results of Young’s Modulus TestPATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0130] As shown in Table 3 and FIG. 11, Example 1 obtained from the process described above in Table 2, which is equivalent to the conventional method of producing the LCP monofilament fishing line, has high Young’s modulus of 81.42 GPa. Such high Young’s modulus makes the LCP monofilament fishing line stiff leading to low knot strength. Meanwhile, Example 2, produced with a DDR of 9 (which is lower than that of Example 1) has the Young’s modulus decreased to 53.46 GPa. Example 3 which is produced with higher die temperature (355 °C) compared to Examples 1 and 2 have further decreased Young’s Modulus of 47.08 GPa. Example 4 is produced by lower die temperature, lower DDR, and lower line speed, compared to those of Example 1 , has a substantially low Young’s Modulus 68.16 GPa. Decreasing Young’s modulus improves the knot strength of the monofilament fishing line. The tensile strength also shows similar results as the Young’s modulus, as shown in FIG. 11 and Table 3. The monofilaments of Examples 2- 4 are suitable for constituting the braided article with high knot strength.

[0131] Tensile Strength vs Tensile Strain

[0132] Stress / strain curves of the inventive LCP monofilament were evaluated. The tensile strength was measured as described above. FIG. 12 is a graph showing tensile stress vs tensile strain of examples of inventive LCP monofilament prepared by different process conditions, and a commercial LCP monofilament fishing line.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1

[0133] Example 1 of the inventive LCP fishing line are prepared by the method as described above. The inventive LCP fishing line in accordance with one or more embodiments has a barrel temperature profile that is profiled differently than conventional polymers. The temperature zones for the feeding, melting, compression and metering zones of the extruder screw are arranged from higher to lower temperatures in a different order than is commonly used for conventional polymers. Specifically, the quenching temperature of an area past an outlet of the extruder die was controlled to be in a range of 0 °C or less and 310 °C or more such to affect the rate of cooling of the LCP monofilament. The line speed was adjusted based on the above quenching temperature. Certain segments within this temperature range are selected for processing the monofilament depending on the resulting properties that are expected in the monofilament.

[0134] Lurthermore, the die orifice used to produce the inventive LCP monofilament of one or more embodiments is designed in a certain way to prevent buildup of the LCP material on the outside of the die opening. Without this die feature, the built up LCP on the die will eventually break off and stick to the monofilament causing the filament to have a rough surface, be larger in diameter, and possibly break the filament at that moment.

[0135] Comparative Example 1 is a fishing line using a commercial LCP. Examples of commercially available LCP include, but are not limited to, Vectran™ HT, NT, and UM (Kuraray Co., Ltd, Japan).

[0136] As shown in PIG. 12, the commercial LCP fishing line has a tensile elongation of less than 5%. Meanwhile, Example 1 has a tensile elongation of greater than 7%, which improves the knot strength. The commercial LCP fishing line was determined to have a knot strength of 250 MPa.

[0137] Multifilament fishing line

[0138] An LCP single filament was prepared in steps similar to Example 4 except that the die temperature was set to 300 °C. The skin layer of the LCP single filament had a thickness smaller than 500 nm and a Young’s modulus less than 5GPa. Three LCP singlePATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 filaments were twisted together to form a 3 -ply twisted thread. The tensile strength, the knot strength, the Young’s modulus, and the wet abrasion cycles were measured and shown in Table 4.

[0139] Table 4. Results of measurements

[0140] The twisted thread was used as is or braided to make the multifilament fishing line. The braid made from six 3-ply twisted threads (i.e., 18 individual fibers) was determined to have physical properties substantially equal to the twisted thread with the exception of the diameter of the braided thread.

[0141] Embodiments of the present disclosure may provide at least one of the following advantages.

[0142] Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

Claims

PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1CLAIMSWhat is claimed:

1. A multifilament fishing line comprising: a braided or twisted article comprising a plurality of monofilaments braided or twisted to form the braided or twisted article, wherein the plurality of monofilaments comprises a liquid crystal polymer formed from a reaction selected from the group consisting of (i) a polycondensation reaction between one or more aromatic hydroxycarboxylic acids; and (ii) a polycondensation reaction between an aromatic hydroxy carboxy lie acid and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aliphatic carboxylic acids, aromatic hydroxyamines, aromatic diamines, aromatic diols, and aliphatic diols, and wherein the multifilament fishing line has a knot strength ranging from 500 to 2,000 MPa.

2. The multifilament fishing line of claim 1, wherein the multifilament fishing line has wet abrasion cycle ranging from 400 times to 2,000 times.

3. The multifilament fishing line of claims 1 or 2, wherein the multifilament fishing line has a friction coefficient ranging from 0.1 to 3.86.

4. The multifilament fishing line of any one of the preceding claims, wherein at least one of the plurality of monofilaments has a skin layer thickness of 500 nm or less.

5. The multifilament fishing line of any one of the preceding claims, wherein the braided article has a fineness ranging from 60 dtex to 2,000 dtex.

6. The multifilament fishing line of any one of the preceding claims, wherein the multifilament fishing line has a tensile strength ranging from 1,400 MPa to 3,100 MPa.

7. The multifilament fishing line of any one of the preceding claims, wherein the multifilament fishing line has a Young’s modulus of greater than 30 GPa.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO18. The multifilament fishing line of any one of the preceding claims, wherein the multifilament fishing line has a tensile elongation ranging from 1.8% to 6.0%.

9. The multifilament fishing line of any one of the preceding claims, wherein the multifilament fishing line has a knot elongation ranging from 1.0% to 6.0%.

10. The multifilament fishing line of any one of the preceding claims, wherein the multifilament fishing line absorbs 0.04 wt% or less of water.

11. The multifilament fishing line of any one of the preceding claims, wherein a molar ratio between aromatic hydroxycarboxylic acids and the at least one comonomer ranges from 80:20 to 70:30.

12. The multifilament fishing line of any one of the preceding claims, wherein the liquid crystal polymer comprises an additive selected from the group consisting of glycidyl epoxy, novolac epoxy, cycloaliphatic epoxy, aromatic epoxy, silane and combinations thereof.

13. The multifilament fishing line of any one of the preceding claims, wherein the plurality of monofilaments and / or the multifilament fishing line are coated with a coating selected from the group consisting of siloxane, silicon carbide-filled epoxy, and urethane, wherein the coating optionally contains a lubricant.

14. The multifilament fishing line of any one of the preceding claims, wherein the plurality of monofilaments each have a diameter ranging from 10 to 800 pm.

15. The multifilament fishing line of any one of the preceding claims, wherein the braided or twisted article has a carrier count ranging from 4 to 54.

16. The multifilament fishing line of any one of the preceding claims, wherein the braided or twisted article has picks per inch (PPI) ranging from 2 to 12.

17. The multifilament fishing line of any one of the preceding claims, wherein the braided or twisted article has a braiding angle ranging from 10 degrees to 75 degrees.

18. A monofilament fishing line comprising:PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO1 a single monofilament; wherein the single monofilament comprises a liquid crystal polymer formed from a reaction selected from the group consisting of (i) a polycondensation reaction between aromatic hydroxycarboxylic acids; and (ii) a polycondensation reaction between an aromatic hydroxy carboxylic acid and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aliphatic carboxylic acids, aromatic hydroxyamines, aromatic diamines, aromatic diols, and aliphatic diols, and wherein the monofilament fishing line has a knot strength in a range from 500 MPa to 2,100 MPa.

19. A method of producing a multifilament fishing line, comprising: polymerizing monomers to form a liquid crystal polymer; melting the liquid crystal polymer to form a molten liquid crystal polymer; extruding the molten liquid crystal polymer to form an extruded liquid crystal polymer; drawing the extruded liquid crystal polymer to form a monofilament having a diameter ranging from 10 to 800 pm; and braiding or twisting the monofilament to form the multifilament fishing line, wherein the monomers are selected from the group consisting of (i) one or more aromatic hydroxycarboxylic acids; and (ii) an aromatic hydroxycarboxylic acid and at least one comonomer selected from the group consisting of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aromatic hydroxyamines, aromatic diamines, aromatic diols, and aliphatic diols.

20. The method of claim 19, wherein the polymerizing comprises a condensation polymerization.

21. The method of claims 19 or 20, wherein the melting further comprises adding an additive to the molten liquid crystal polymer.PATENT APPLICATIONATTORNEY DOCKET NO. 18984-015WO122. The method of any one of claims 19 to 21, wherein the method further comprises adding an additive during the extruding or after the extruding.

23. The method of claim 22, wherein the additive is selected from the group consisting of glycidyl epoxy, novolac epoxy, cycloaliphatic epoxy, aromatic epoxy, silane, and combinations thereof.

24. The method of any one of claims 19 to 24, further comprising coating the monofilament with a coating selected from the group consisting of siloxane, silicon carbide-filled epoxy, and urethane, wherein the coating optionally contains a lubricant.

25. The method of any one of claims 19 to 24, further comprising coating the multifilament fishing line with a coating selected from the group consisting of siloxane, silicon carbide- filled epoxy, and urethane, wherein the coating optionally contains a lubricant.

26. The method of any one of claims 19 to 25, wherein the extruding is performed at an extrusion temperature ranging from 280 °C to 360 °C.

27. The method of any one of claims 19 to 26, wherein the extruding is performed at an extrusion speed ranging from 50 to 750 m / min.

28. The method of any one of claims 19 to 27, wherein the drawing is performed at a draw ratio ranging from 9 to 156.

29. The method of any one of claims 19 to 28, wherein the drawing is performed at a drawing speed ranging from 50 to 750 m / min.

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