HMPE fibers with improved bending fatigue performance

Abstract

To provide continuous filament-based elongated bodies with improved durability and bending fatigue performance.SOLUTION: An elongated body is a multifilament ultra-high molecular weight polyolefin fiber in which at least one component fiber has a filament intrinsic viscosity (IVf) of 15 dl / g to about 45 dl / g when measured in decalin at 135°C. The at least one multifilament ultra-high molecular weight polyolefin fiber is formed from a plurality of fibers having a toughness of at least 32 g / denier, a denier of above 800 and a denier per filament of above 2.0. High toughness, combined with high fiber denier and high filament denier (dpf), enhances repeated bending on a tug (CBOS) when the elongated body is incorporated into a multi-fiber structure such as a rope.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This technology relates to improvements in ropes, specifically to high-toughness synthetic ropes having improved durability and bending fatigue performance. [Background technology]

[0002] Synthetic fiber ropes have been used in a variety of applications, including various marine applications. One type of rope with superior properties is one made from high-modulus polyolefin fibers and / or yarns. High-toughness polyolefin fibers, such as Honeywell International Inc.'s SPECTRA® stretchable chain polyethylene fiber, are known to be particularly useful in marine applications due to their high strength (15 times stronger than steel by weight), light weight (light enough to float (0.97 g / cc specific gravity)), hydrophobicity, corrosion resistance, excellent fungal growth resistance, excellent abrasion resistance, excellent bending and bending fatigue performance, low coefficient of friction, and very good UV irradiation resistance, making them extremely durable for long-term marine use.

[0003] In particular, with regard to high strength, fibers formed from ultra-high molecular weight polyethylene (UHMW PE) are known to possess excellent tensile properties such as toughness, tensile modulus, and fracture energy. The term "toughness" refers to the tensile stress expressed as force (grams) per unit linear density (denier) of an unstressed sample, as measured by ASTM D2256. The term "initial tensile modulus" refers to the ratio of the change in toughness, expressed as gram-force per denier (g / d), to the change in strain, expressed as the ratio of the original fiber / tape length (in / in). As used herein, the terms "initial tensile modulus," "tensile modulus," and "modulus" refer to the modulus of elasticity of the fiber as measured by ASTM 2256.

[0004] Such high-toughness fibers are typically produced by a "gel spinning" process, also known as "solution spinning." In this type of process, a solution of ultra-high molecular weight polyethylene (UHMW PE) and a solvent is formed, and then the solution is extruded through a multi-flute spinneret (e.g., having 10 to 3000 spinning holes) to form solution filaments (one filament per spinning hole). These solution filaments are then cooled to form gel filaments, and the solvent is extracted to form dry filaments. These dry filaments are collected into bundles, which are referred to in the art as "fibers" or "yarns." The fibers / yarns are then stretched to their maximum stretch limit to increase their toughness.

[0005] Preparation of high-strength polyethylene filaments and / or multifilament fibers / yarns is, for example, as specified in U.S. Patent Nos. 4,413,110, 4,536,536, 4,551,296, 4,663,101, 5,006,390, 5,032,338, 5,578,374, 5,736,244, 5,741,451, 5,958,582, 5,972,498, and 6,448. These are described in Patents No. 359, No. 6,746,975, No. 6,969,553, No. 7,078,099, No. 7,344,668, No. 8,444,898, No. 8,506,864, No. 8,747,715, No. 8,889,049, No. 9,169,581, No. 9,365,953, and No. 9,556,537, all of which are incorporated herein by reference to the extent consistent with this specification. Each of these patents teaches progressive improvements in UHMW PE processing technology and describes major obstacles in improving the tensile properties of UHMW PE fibers. For example, while stretching increases the toughness and tensile modulus of UHMW PE fibers, there is a limit to how far they can be stretched without breaking. The maximum amount that a fiber can be stretched, Therefore, the maximum toughness that can be achieved for a particular fiber type depends on several factors, including both improved raw materials and processing capabilities.

[0006] To increase the toughness of fibers, polyethylene solutions and their precursors (i.e., the polymers and solvents forming the solution) must have specific properties, such as high intrinsic viscosity ("IV"), and must be manufactured in a specific manner. For example, U.S. Patent No. 8,444,898 teaches a process for producing high-toughness fibers by a special process that limits the time the fiber-forming polymer / solvent mixture is exposed to extreme processing conditions inside an extruder that would decompose the polymer. This process is distinct from other methods that require longer residence times in the extruder, which would reduce the maximum achievable fiber toughness due to the decomposition of the relevant polymers in the extruder. U.S. Patent No. 8,747,715 teaches a process for producing high-toughness polyethylene yarn, which involves highly oriented fibers to form a product having a toughness greater than approximately 45 g / d and a tensile modulus greater than approximately 1400 g / d. This process requires a step to maintain the intrinsic viscosity of the polymer so that fibers with fiber IV greater than approximately 19 dl / g and toughness greater than approximately 45 g / dg are produced. These are just two examples of significant scientific and technological efforts that could lead to improvements in the tensile properties of polyethylene fibers, even if only gradually.

[0007] Ropes formed from high-strength polyethylene fibers are known and have been used, for example, in applications requiring excellent bending fatigue resistance. See, for example, U.S. Patent Application Publications 2007 / 0202328 and 2007 / 0202331, both typically owned by Honeywell International Inc., which teach ropes with good bending fatigue performance when repeatedly bent on sheaves, pulleys, or posts in marine applications. Despite the existing high performance of such ropes, there is a continuing need for products with improved properties and performance. Specifically, there is a continuing need in the art for synthetic ropes that exhibit greater long-term durability when repeatedly bent in this manner on sheaves, particularly when used in heavy lifting applications in industrial applications, and there is a need to improve the fatigue life of high-performance synthetic ropes. In particular, there is a need to improve the cyclic bend over sheave (CBOS) performance of ropes made from high-performance polyolefin fibers and yarns on sheaves. This technology addresses the This provides a solution to this need in the technical field.

[0008] In this regard, fiber orientation during the fiber manufacturing process is known to increase the toughness of the fiber by exposing the fiber to heat and tension under carefully controlled conditions, as is conventionally known in the art. In addition to increasing fiber toughness, fiber orientation (i.e., stretching; drawing) also makes the fiber finer. In a single multifilament fiber containing a combination of fine filaments, the orientation of the fibers, in turn, thins each of the individual constituent filaments that make up the fiber. In the textile field, a common measure of fiber / yarn fineness is "denier," which is a unit of linear density equal to the mass (grams) per 9000 meters of fiber / yarn. In addition to a decrease in fiber denier, a decrease in the denier of the filaments that make up the fiber makes the fiber more susceptible to breakage. This decrease in fiber / filament denier also makes it more susceptible to bending fatigue, which is a common problem in applications where elongated bodies such as ropes formed from the fiber typically pass through one or more sheaves. Therefore, in the context of this disclosure, since the fiber is intended to be used in the manufacture of ropes for heavy lifting applications, which require substantial fiber strength, resistance to axial breakage, and the ability to withstand bending over time without breaking, each of the fiber toughness, fiber denier, and denier per filament are particularly important properties.

[0009] These fine particles are useful in applications where particularly excellent strength properties and bending fatigue resistance are required. To manufacture elongated fibers, it is necessary to incorporate fibers that have a balance of physical properties that cannot be obtained with known fibers currently available. Specifically, in order to achieve the objectives of this disclosure, the filament intrinsic viscosity (IV) is 15 dl / g to approximately 45 dl / g when measured in decalin at 135°C. f ), it is necessary to incorporate one or more ultra-high molecular weight polyolefin fibers having a combination of toughness of at least 32 g / denier, denier greater than 800, and denier per filament greater than 2.0 into the elongated structure, preferably the IV of the filament is equal to the denier per filament of the filament. f The product obtained by multiplying by is at least 75.0, preferably at least 75.0 to 110.0, IV fThe ratio of the denier per filament was found to be from 4.0:1 to 8.0:1. This was achieved by modifying known fiber / filament manufacturing techniques to produce an elongate body incorporating one or more fibers having these properties and improving the quality of the fiber / filament.

Summary of the Invention

[0010] The present disclosure provides a multi-fiber elongate body, such as a rope, formed from fibers having an unprecedented relationship between intrinsic viscosity, denier per filament, and toughness, thereby unexpectedly achieving enhanced flexural fatigue resistance of the elongate body that meets the needs in the art.

[0011] In particular, the present disclosure provides an elongate body comprising a plurality of fibers, wherein at least one of the fibers is a multifilament ultra-high molecular weight polyolefin fiber having a filament intrinsic viscosity (IV f ) of 15 dl / g to about 45 dl / g when measured in decalin at 135 °C, and the at least one multifilament ultra-high molecular weight polyolefin fiber has a toughness of at least 32 g / denier, a denier of more than 800, and a denier per filament of more than 2.0.

[0012] Also provided is an elongate body comprising at least one multifilament fiber comprising ultra-high molecular weight polyolefin fibers formed from a plurality of ultra-high molecular weight polyolefin filaments, wherein the ultra-high molecular weight polyolefin filaments have a filament intrinsic viscosity (IV f ) of 15 dl / g to about 45 dl / g when measured in decalin at 135 °C, the multifilament ultra-high molecular weight polyolefin fiber has a denier of more than 800, each filament of the multifilament ultra-high molecular weight polyolefin fiber has a denier of at least 2.0, and the product of the IV f of the filament and the denier per filament of the filament is 75.0 to 110.0.

[0013] Furthermore, a method for producing an elongated body, a) a step of providing a plurality of fibers, wherein at least one of the fibers has a filament intrinsic viscosity (IV f ) of 15 dl / g to about 45 dl / g when measured in decalin at 135 °C and is a multifilament ultra-high molecular weight polyolefin fiber, and the at least one multifilament ultra-high molecular weight polyolefin fiber has a toughness of less than 32 g / denier, a denier of more than 800, and a denier per filament of more than 2.0, the step of providing; b) a step of stretching each multifilament fiber to increase the toughness of the fiber to at least 32 g / denier, wherein the denier per filament remains more than 2.0, the step of increasing; c) optionally, a step of coating at least a part of each fiber with either a thermoplastic resin or oil; d) a step of twisting, entangling, or braiding the fibers to form an elongated body structure; e) optionally, a step of heating and stretching the elongated body structure to thermoset the fibers of the elongated body, is provided.

Brief Description of the Drawings

[0014] [Figure 1] An exemplary post-drawing process for stretching fibers by passing a plurality of horizontally adjacent ovens in one direction is shown. [Figure 2] An exemplary post-drawing process for stretching fibers by passing a single oven in a plurality of directions is shown. [Figure 3] A graph plotting the toughness of fibers against the Cogswell elongation viscosity of a 10 wt% UHMW PE polymer solution in mineral oil at 250 °C for fibers spun from a solution of UHMW PE polymer.

Modes for Carrying Out the Invention

[0015] As used herein, “fiber” refers to an elongated strand of a material, such as a strand of polymer material, whose length dimension is much greater than its cross-sectional dimensions of width and thickness. Fibers are preferably long, continuous strands rather than short segments of a strand referred to in the art as “staple” or “staple fiber.” As used herein, the term “elongated” has its usual, conventional meaning of having a shape that is much longer than its width. In the context of this disclosure, “elongated body” may be a strand containing a single fiber or a plurality of composite fibers, which may be combined, for example, by twisting, entanglement, braiding, or a combination thereof. An example of an elongated body containing a plurality of fibers combined by twisting, entanglement, braiding, or a combination thereof is a rope, such as a braided rope.

[0016] The cross-sections of fibers for use in this disclosure may vary considerably, and such fibers may have a circular, flat, or elliptical cross-section. Thus, the term “fiber” includes filaments, ribbons, elongated pieces having regular or irregular cross-sections, but it is preferable that the fiber has a substantially circular cross-section. A “strand” in the usual definition is a single, thin length, such as a thread or fiber. A single continuous filament fiber may be formed from only one filament or from multiple filaments. A fiber formed from only one filament is referred to herein as either a “single-filament” fiber or a “monofilament” fiber, and a fiber formed from multiple filaments is referred to herein as a “multifilament” fiber. When defined herein, a multifilament fiber preferably comprises 2 to about 3000 filaments, more preferably 2 to about 1000 filaments, even more preferably 30 to 500 filaments, even more preferably 40 to 500 filaments, even more preferably about 40 to about 360 filaments, and most preferably about 120 to about 240 filaments. Multifilament fibers are also often referred to as filament bundles or bundles of filaments in the art. Bundled groups of fibers may also be referred to as fiber bundles or bundles of fibers. The definition of multifilament fibers as used herein also includes pseudo-monofilament fibers, which are a technical term describing multifilament fibers that are at least partially fused and may appear to be monofilament fibers. As used herein, the term “yarn” is defined as a single continuous strand consisting of multiple fibers or filaments and is often used interchangeably with multifilament fibers.

[0017] An elongated body comprising or essentially comprising one or more polyolefin fibers or a combination of polyolefin fibers and non-polyolefin fibers, wherein at least one of the polyolefin fibers forming the elongated body has a filament intrinsic viscosity (IV) of 15 dl / g to about 45 dl / g when measured in decalin at 135°C.f ) and having at least 32 g / denier of toughness, more than 800 denier, and more than 2.0 denier per filament, a multi-filament ultra-high molecular weight polyolefin fiber is provided herein, wherein the at least one multi-filament ultra-high molecular weight polyolefin fiber has a toughness of at least 32 g / denier, more than 800 denier, and more than 2.0 denier per filament. A slender body is provided herein that has a denier.

[0018] It is generally known that very high performance filaments and fibers with excellent tensile properties are produced by gel / solution spinning of ultra-high molecular weight polyolefins (UHMW PO), especially ultra-high molecular weight polyethylene (UHMW PE). Generally, the "gel spinning" process involves forming a solution of a spinning solvent and a polymer (such as UHMW PE) and passing the solution through a spinneret to form a plurality of solution filaments that are collected to form a fiber (or yarn). These solution filaments are then cooled to form gel filaments. Next, it is necessary to remove the spinning solvent from the gel filaments to form essentially dry multi-filament fibers, which are then oriented (i.e., stretched or drawn) to enhance their tensile properties. It is also known to orient the filaments at the solution and gel stages to enhance fiber properties. Generally, higher fiber tensile properties are obtained from polyethylene having a higher intrinsic viscosity. The intrinsic viscosity of a polymer is a measure of the molecular weight of the polymer. In most solution / gel spinning methods used to form high-strength fibers, it is known that the polymer is partially decomposed when it is mixed with the solvent in an extruder and converted into a solution. Such decomposition slightly reduces the molecular weight, and thus the intrinsic viscosity decreases. Therefore, in a typical method for producing UHMW PE filaments / fibers, the initial intrinsic viscosity (IV0) of the polymer raw material spun to form the filaments / fibers is greater than IV f and this in turn affects the maximum achievable toughness of the fibers formed therefrom.

[0019] Some methods, such as those in U.S. Patent Nos. 7,638,191 and 7,736,561, teach the specific processing advantages of intentionally reducing intrinsic viscosity. On the other hand, other methods, such as those in U.S. Patent Nos. 8,444,898, 8,506,864, 8,747,715, 8,889,049, 9,169,581, 9,365,953, and 9,556,537, teach the specific advantages of maximizing molecular weight and intrinsic viscosity. U.S. Patents 8,747,715, 9,365,953, and 9,556,537 specifically teach a method for producing extremely tough fibers, i.e., fibers with a toughness of at least 45 g / d, by processing UHMW PE powder raw materials having a very high IV0 of at least 30 dl / g. U.S. Patents 8,444,898 and 8,506,864 teach that the decrease in molecular weight can be minimized by minimizing the time during which UHMW PE polymer raw materials are mixed with the spinning solvent in the extruder. In this regard, the initial steps of a conventional UHMW PE solution / gel spinning process include: (1) processing UHMW PE powder and spinning solvent in either an extruder or a combination of an extruder and a heated vessel to form a solution of polymer and spinning solvent; (2) passing the solution through a spinneret (as described above) to form solution fibers containing multiple solution filaments; (3) cooling the solution fibers to form gel fibers; (4) removing the spinning solvent by either extraction or evaporation to form essentially dry solid fibers; and then (5) stretching at least one of the solution yarn, gel yarn, and dry yarn to form a final multifilament fiber product.

[0020] For the purposes of this disclosure, the final fiber product has an intrinsic viscosity of filament / fiber of 15 dl / g or more, preferably 15 dl / g to about 45 dl / g (IV) (measured in decalin at 135°C according to the technique of ASTM D1601). fIt was found that the desired fiber properties are achieved when ) is present. Therefore, the fibers of this disclosure can be produced from any conventionally known solution or gel spinning process, provided that the method is measured in decalin at 135°C, IV f at least 15 dl / g, more specifically, IV f The process has been improved to minimize the decrease in polymer molecular weight during the fabrication of multifilament ultra-high molecular weight polyolefin fibers, so that the molecular weight is between 15 dl / g and approximately 45 dl / g. In a particular embodiment, the filament / fiber manufacturing methods of U.S. Patents No. 8,444,898, 8,506,864, 8,747,715, 8,889,049, 9,169,581, 9,365,953, and 9,556,537 are most effective in achieving this objective and are therefore most preferred for the production of the UHMW PE fibers of this disclosure.

[0021] To form such fibers, a process is required to maintain the intrinsic viscosity (IV0) of the UHMW PE polymer (measured in decalin at 135°C according to the technique of ASTM D1601; unit dl / g). As described in U.S. Patent No. 9,169,581, an effective process includes, for example, sparging nitrogen into the spinning solvent before mixing with the UHMW PE polymer, or sparging nitrogen gas into the polymer-solvent mixture and / or polymer-solvent solution, thereby reducing or completely eliminating the presence of oxygen, which is known to cause shear-induced chain breakage. Nitrogen sparging at temperatures below 290°C in particular promotes long-chain branching rather than chain breakage, thus preserving IV0. Nitrogen sparging preferably refers to continuously blowing nitrogen into the solvent / mixture / solution, such as by continuously blowing nitrogen into the slurry tank containing the solvent-polymer slurry to be added to the extruder for mixing. Nitrogen sparging in the slurry tank may be carried out at a rate of, for example, about 2.4 liters / min to about 23.6 liters / min. However, any conventional sparging technique may be used. Other means of reducing or eliminating the presence of oxygen from the polymer-solvent mixture and / or solution during polymer processing, such as incorporating antioxidants into the polymer-solvent mixture and / or solution, should be equally effective. The use of antioxidants is taught in U.S. Patent No. 7,736,561, typically owned by Honeywell International Inc. In this embodiment, the concentration of the antioxidant should be sufficient to minimize the effects of foreign oxygen, but not high enough to react with the polymer. The weight ratio of the antioxidant to the solvent is preferably about 10 million parts to about 1,000 million parts. Most preferably, the weight ratio of the antioxidant to the solvent is about 10 million parts to about 100 million parts. Useful antioxidants include, non-exclusively, hindered phenols, aromatic phosphites, amines, and mixtures thereof.Preferred antioxidants include 2,6-di-tert-butyl-4-methylphenol, tetrakis[methylene(3,5-di-tert-butylhydroxyhydrocinnamate)]methane, tris(2,4-di-tert-butylphenyl)phosphite, octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,5,7,8-tetramethyl-2(4',8',12'-trimethyltridecyl)chroman-6-ol, and mixtures thereof. More preferably, the antioxidant is 2,5,7,8-tetramethyl-2(4',8',12'-trimethyltridecyl)chroman-6-ol, commonly known as vitamin E or α-tocopherol. Since it is sometimes desirable to maintain the polymer molecular weight and IV0, other additives such as processing aids and stabilizers may be optionally added to the polymer-solvent mixture.

[0022] Furthermore, polymer degradation can also be controlled during the initial stages of conventional gel spinning processes (i.e., (1) slurry formation, (2) heating the slurry to melt the polymer and form a liquid mixture under conditions of vigorous discrete and dispersed mixing, thereby reducing the domain size of the molten polymer and solvent in the mixture to microscopic dimensions, and (3) allowing sufficient time for the solvent to penetrate the polymer and for the polymer to diffuse into the solvent to form a solution) by controlling the harshness of the environment in which the polymer is processed. For example, to minimize polymer degradation resulting from high heat and shear stress on the polymer, which is detrimental to the polymer molecular weight, it is necessary to minimize the residence time of the polymer in the extruder, as described in U.S. Patent No. 8,444,898. Therefore, outside the extruder (e.g., It is desirable to initiate the formation of a polymer-solvent liquid mixture by heating the slurry tank, thereby creating a milder environment and some melt. This, in turn, reduces the polymer residence time in the extruder, thereby reducing the thermal and shear-induced decomposition of the polymer.

[0023] In addition to increasing the residence time of the polymer in the slurry tank, preferably a heated slurry tank, lowering the extruder temperature helps to produce the solution in a milder environment. For example, the temperature at which a liquid mixture of molten UHMW PE polymer and spinning solvent is formed in an extruder is typically about 140°C to about 320°C. To minimize polymer degradation, it is necessary to use temperatures lower than this range. As is also known from the commonly owned U.S. Patent No. 8,444,898, the residence time of the mixture in the extruder can also be limited by rapidly passing the polymer-solvent mixture from the extruder to a heated vessel (e.g., a heated pipe with or without a static mixer), in which the remaining time is provided for the solvent and polymer to fully diffuse to each other and form a uniform and homogeneous solution. In this regard, operating conditions that can promote the formation of a homogeneous solution include, for example, (1) raising the temperature of the liquid mixture of UHMW PE and spinning solvent to a temperature near or higher than the melting temperature of UHMW PE, and (2) maintaining the liquid mixture at the raised temperature for a sufficient time for the spinning solvent to diffuse into the UHMW PE and for the UHMW PE to diffuse into the spinning solvent. Preferably, most of the time required to convert the polymer-solvent slurry into a liquid mixture, and then into a homogeneous solution, is spent in a heated vessel, and preferably the average residence time of the polymer-solvent mixture in the extruder is about 1.5 minutes or less, more preferably about 1.2 minutes or less, and most preferably about 1.0 minute or less. The heated vessel, such as an extruder, is typically maintained at a temperature of about 140°C to about 320°C, but no active mixing takes place. The residence time of the liquid mixture in the heated container may be about 2 minutes to about 120 minutes, preferably about 6 minutes to about 60 minutes, until a solution is formed. Variations of this procedure can also be used appropriately. For example, the arrangement and use of the heated container and the extruder may be reversed, in which case a liquid mixture of UHMW PE and spinning solvent is first formed in the heated container, and then passed through the extruder to form a solution.

[0024] Further opportunities exist to maintain intrinsic viscosity during post-solution processing. For example, upon exiting the spinneret, the polymer solution passes through a gaseous space into a liquid quenching bath (e.g., water, ethylene glycol, ethanol, isopropanol, preferably maintained at approximately -35°C to approximately 35°C) to form gel filaments. If the space contains oxygen, such as when filled with air, the solution filaments are susceptible to oxidation as they pass through this space, thus minimizing polymer degradation and preserving the fiber's intrinsic viscosity. f To maximize the effect, it may be desirable to fill the gas space with another inert gas, such as nitrogen or argon, to prevent any oxidation. Also, limiting the length of the gas space, especially when filling the gap with an inert gas is not practical, also minimizes the possibility of oxidation. The length of the gas space between the spinneret and the surface of the liquid quenching bath is preferably about 0.3 cm to about 10 cm, more preferably about 0.4 cm to about 5 cm. If the residence time of the solution filament in the gas space is less than about 1 second, the gas space may be filled with air; otherwise, it is most preferable to fill the space with an inert gas.

[0025] High IV0 and IV f This can also be achieved by improving the quality of the polymer raw materials. For example, it is known that the particle size and particle size distribution of particulate UHMW PE polymer can affect the ultimate tensile strength of the fiber and the degree to which the UHMW PE polymer dissolves in the spinning solvent during the formation of the gel-spun solution. It is desirable that the UHMW PE polymer dissolves completely in the solution, and therefore, from UHMW PE polymer having an average particle size of about 100 μm to about 400 μm, most preferably about 100 μm to about 200 μm The fibers are preferably spun, and the particles also have a weight-average molecular weight of preferably about 300,000 to about 7,000,000, more preferably about 700,000 to about 5,000,000, as described in U.S. Patent No. 9,169,581. Preferably, the UHMW PE of this disclosure has a weight-average molecular weight to number-average molecular weight ratio (M w / Mn ) is 4 or less, more preferably M w / M n The ratio is 3 or less, and more preferably M w / M n The ratio is 2 or less, and more preferably M w / M n The ratio is approximately 1.

[0026] UHMW PE itself may contain small amounts of additives, generally less than about 5% by weight, preferably less than about 3% by weight, such as antioxidants, heat stabilizers, colorants, flow promoters, solvents, etc. U.S. Patents 8,747,715, 8,889,049, 9,365,953, and 9,556,537 further recognize the importance of a property known as the Cogswell extensional viscosity (λ) of the UHMW PE polymer raw material and its influence on the processability and tensile properties of the fibers, stating that a 10% by weight UHMW PE polymer solution in mineral oil at 250°C has a viscosity of λ ≥ 5,917(IV) 0.8 This indicates that the formula must have a Cogswell extensional viscosity (λ) according to the formula (wherein IV refers to IV0).

[0027] Preferred spinning solvents that can be used when forming solution / gel spun fibers from the UHMW PE polymer include hydrocarbons having a boiling point greater than 100°C at atmospheric pressure. Preferred spinning solvents can be selected from the group consisting of aliphatic, alicyclic, and aromatic hydrocarbons, as well as halogenated hydrocarbons such as dichlorobenzene, and mixtures thereof. In some examples, the spinning solvent may have a boiling point of at least about 180°C at atmospheric pressure. In such examples, the spinning solvent can be selected from the group consisting of halogenated hydrocarbons, mineral oil, decalin, tetralin, naphthalene, xylene, toluene, dodecane, undecane, decane, nonane, octene, cis-decahydronaphthalene, trans-decahydronaphthalene, low molecular weight polyethylene wax, and mixtures thereof. Preferably, the solvent is selected from the group consisting of cis-decahydronaphthalene, trans-decahydronaphthalene, decalin, mineral oil, and mixtures thereof. The most preferred spinning solvent is mineral oil, such as HYDROBRITE® 55O PO white mineral oil, commercially available from Sonneborn, LLC (Mahwah, NJ). HYDROBRITE® 55O PO mineral oil, when calculated according to ASTM D3238, consists of approximately 67.5% to 72.0% paraffinic carbon and approximately 28.0% to 32.5% naphthenic carbon. The slurry, liquid mixture, and solution formed according to the preferred gel / solution spinning method each contain approximately 1% to 50% by weight of UHMW PE, preferably approximately 1% to 30% by weight of the solution, more preferably approximately 2% to 20% by weight of the solution, and even more preferably approximately 3% to 10% by weight of the solution.

[0028] U.S. Patents 8,444,898 and 8,506,864 teach additional steps that may be taken to minimize the decrease in intrinsic viscosity during the fiber spinning process, specifically, first forming a slurry from UHMW PE powder and solvent in an extruder, and then spinning at least 2.0D per minute. 2The instructions teach that polymer degradation can be minimized by processing the slurry through an extruder at an extrusion rate of grams (g / min; D represents the screw diameter of the extruder in centimeters), thereby forming a liquid mixture. This liquid mixture is then converted into a solution not in the extruder, but in a heated container, so that the heated container exerts only very small, if any, shear stress on the mixture.

[0029] Therefore, consistent with the purposes of this disclosure, at least one or all of the fibers forming the elongated bodies of this disclosure contain at least about 21 dl / g, or more than about 21 dl / g, more preferably about 21 dl / g to about 100 dl / g, even more preferably about 30 dl / g to about 100 dl / g, even more preferably about 35 dl / g to about 100 dl / g, and It is necessary to be made from a UHMW polyethylene polymer having an intrinsic viscosity of more preferably about 40 dl / g to about 100 dl / g, even more preferably about 45 dl / g to about 100 dl / g, and even more preferably about 50 dl / g to about 100 dl / g, and all intrinsic viscosity values ​​specified throughout this specification are measured in decalin at 135°C. A high initial IV0 of at least about 21 dl / g allows for some degree of IV decrease, while a high IV of 15 dl / g or more is required. f IVs having typically 15 dl / g to about 45 dl / g, or 30 dl / g to about 45 dl / g, or 35 dl / g to about 45 dl / g, or 40 dl / g to about 45 dl / g. f We guarantee the production of fibers that possess the following properties.

[0030] In addition to describing effective methods for producing UHMW PE fibers having an IVf of 15 dl / g or more, many of the US patents incorporated above also teach methods for stretching fibers during the spinning process. US Patents 8,444,898, 8,506,864, 8,747,715, 8,889,049, 9,365,953, and 9,556,537 specifically teach methods for stretching fibers during the spinning process, as well as post-spinning stretching operations to further increase the toughness of the fibers. While each of these methods for stretching fibers is effective in strengthening the toughness of the fibers, stretching the fibers reduces the denier and denier per filament (i.e., the denier of each individual filament forming a multifilament fiber (i.e., forming a fiber / bundle)), making the fibers more fragile. Therefore, the spinning and drawing methods described in the above patent can be usefully used to produce one or more UHMW PE fibers of the present disclosure, but it is necessary to limit the degree of drawing to ensure a filament denier greater than 2.0 and an overall fiber denier greater than 800, preferably at least 1000, and most preferably 1600 or more, while also achieving a high fiber toughness of at least 32 g / d.

[0031] This limits the extent of post-drawing operations for such high molecular weight fibers (although the drawing of solution fibers and gel fibers may be similarly limited), and is achievable when the intrinsic viscosity of the polymer (a measure of polymer molecular weight) is greater than 15 dl / g as raw material and is maintained greater than 15 dl / g during and after the fiber spinning process. For example, U.S. Patent No. 9,365,953 relates to a UHMW PE fiber having a toughness of at least about 45 g / denier, wherein a) a slurry containing a UHMW PE polymer (supplied as powder) and a spinning solvent is fed into an extruder to produce a liquid mixture, wherein the UHMW PE polymer has an intrinsic viscosity of at least about 30 dl / g in decalin at 135°C, or the UHMW a) Feeding the PE polymer and spinning solvent into an extruder to form both a slurry and a liquid mixture within the extruder; b) Passing the liquid mixture through a heated container to form a homogeneous solution containing the UHMW PE polymer and the spinning solvent; c) Supplying the solution from the heated container to a spinneret to form solution fibers; d) Stretching the solution fibers flowing out of the spinneret at a stretch ratio of approximately 1.1:1 to approximately 30:1 to form stretched solution fibers; e) Stretching the stretched solution fibers to form UHMW The present invention teaches a UHMW PE fiber produced by a process comprising: f) cooling the PE polymer to a temperature lower than its gelation point to form gel fibers; g) stretching the gel fibers in one or more steps at a first stretch ratio DR1 of about 1.1:1 to about 30:1; h) stretching the gel fibers at a second stretch ratio DR2; i) removing the spinning solvent from the gel fibers in a solvent removal device to form dry fibers; j) stretching the dry fibers in at least one step at a third stretch ratio DR3 to form partially oriented fibers; k) moving the partially oriented fibers to a post-stretching operation; and d) stretching the partially oriented fibers at a post-stretching temperature to a fourth stretch ratio DR4 of about 1.8:1 to about 15:1 to form a highly oriented fibrous product having a toughness of at least about 45 g / denier.

[0032] Therefore, the above fiber of U.S. Patent No. 9,365,953 is subjected to multiple drawing processes. The term "stretch ratio" refers to the ratio of the speeds of the stretch rolls used during the orientation process. First, the solution fibers flowing from the spinneret are stretched at a stretch ratio of approximately 1.1:1 to 30:1. Next, the solidified gel fibers are stretched at two stretch ratios: DR1, which is approximately 1.1:1 to 30:1, and DR2, which is approximately 1.5:1 to 3.5:1. Then, the dried fibers are stretched at a stretch ratio of approximately 1.10:1 to 3.00:1 (DR3), and then subjected to an offline post-stretching operation to increase the fiber toughness to 45 g / denier by stretching at a stretch ratio of approximately 1.8:1 to 15:1 (DR4). Since each of these stretching steps gradually increases the fiber toughness while decreasing the fiber denier, the stretch profile can be customized to similarly limit the increase in toughness and decrease in denier. For example, U.S. Patent No. 9,365,953 indicates that the composite stretching of gel fibers and dry fibers, which can be determined by multiplying DR1, DR2, and DR3 (described as DR1×DR2×DR3:1 or (DR1)(DR2)(DR3):1), must be at least about 5:1, more preferably at least about 10:1, and most preferably at least 12:1. In embodiments following a similar stretching process according to U.S. Patent No. 9,365,953, but where the stretching of solution fibers and gel fibers is limited, the value of DR1×DR2×DR3:1 (or (DR1)(DR2)(DR3):1) may be from 1.1:1 to less than 5:1, or from 1.1:1 to 4:1, or from 1.1:1 to 3:1, or from 2:1 to 4:1.

[0033] In preferred embodiments of this disclosure, UHMW PE fibers useful herein are produced according to the method of U.S. Patent No. 9,365,953, but the post-drawing of the fibers is limited to maintaining a filament denier greater than 2.0, a total fiber denier greater than 800, preferably at least 1000, preferably 1600 or more, and a fiber toughness of at least 32 g / d, preferably 35 g / d to 45 g / d. This can be achieved, for example, by performing a post-drawing operation according to the process disclosed in U.S. Patent No. 9,365,953, where the post-drawing draw ratio (DR4) is about 1.1:1 to about 4.5:1, or about 2.0:1 to about 3.5:1, or about 2.5:1 to about 2.7:1. Alternatively, the post-extension may be carried out with extension ratios of approximately 1.1:1 to 1.7:1, or approximately 1.1:1 to 1.6:1, or 1.1:1 to 1.5:1, or approximately 1.1:1 to approximately 1.4:1, or 1.1:1 to 1.3:1, or 1.1:1 to 1.2:1. Any of these post-stretching elongation ratio ranges is limited so that DR1, DR2, and DR3 as defined in U.S. Patent No. 9,365,953 have a DR1 × DR2 × DR3:1 ratio (or (DR1)(DR2)(DR3):1 ratio) from 1.1:1 to less than 5:1, or from 1.1:1 to 4:1, or from 1.1:1 to 3:1, or from 2:1 to 4:1, and after all fibers have been stretched / elongated, such fibers (multifilament fibers) have a denier (dpf) per filament in the range of about 2.0 dpf to about 7.0 dpf, more preferably about 2.3 dpf to about 6.0 dpf, more preferably about 2.5 dpf to about 5.0 dpf, most preferably about 3.0 dpf to about 5.0 dpf, and a filament intrinsic viscosity (IV) of 15 dl / g to about 45 dl / g when measured in decalin at 135°C. f), and may be carried out in conjunction with limiting the overall elongation to have a toughness of at least 32 g / denier; according to a preferred embodiment of the present disclosure, the elongated body / rope of the present disclosure comprises at least one multifilament polyolefin fiber having all of the above properties, also having a denier greater than 800, i.e., the at least one multifilament polyolefin fiber is manufactured to contain at least enough constituent filaments so that the sum of the deniers of all constituent filaments forming the fiber is greater than 800. A fiber formed from filaments having deniers in these ranges, as well as the other properties of intrinsic viscosity and toughness, is stretched to a degree significantly lower than its maximum elongation capacity, and the fiber has an elongation at break of about 4.0% or less, typically about 3.0% to 4.0%, when measured according to the ASTM D638 test method.

[0034] In this regard, the method of stretching fibers is conventionally known in the art, and in the United States Any preferred method may be used, including the methods of Japanese Patent Nos. 6,969,553, 7,370,395, 7,344,668, 8,747,715, 9,365,953, and 9,556,537, each incorporated herein by reference to the extent consistent herein. Generally, post-stretching of dry fibers is achieved in at least one step by passing a continuous fiber through a heated environment provided by a heating device such as a forced-air convection oven at a post-stretching temperature of about 125°C to about 160°C. Stretching may be carried out by passing the fiber through the oven once or more times, and stretching is initiated when the fiber reaches a desired temperature within the above range. Exemplary post-stretching devices are shown in Figures 1 and 2. As shown in Figure 1, the post-drawing process 200 is performed by passing continuous fibers 208 through a heating device 202 having a first set of rolls 204 located outside the heating device 202 and a second set of rolls 206 located outside the heating device 202. The fibers 208 are fed from a source and can pass through the first set of rolls 204. The first set of rolls 204 may be driven rolls operated to rotate at a desired speed to provide the fibers to the heating device 202 at a desired feed rate of V1 meters / min. The first set of rolls 204 may include a plurality of individual rolls 210. In one example, a first few individual rolls 210 are not heated, and the remaining individual rolls 210 are heated to preheat the fibers 208 before they enter the heating device 202. The first set of rolls 204 includes a total of seven individual rolls 210, as shown in Figure 1, but the number of individual rolls 210 may be more or less, depending on the desired configuration.

[0035] As shown in the figure above, the fibers 208 can be fed into a heating device 202 which includes one or more ovens. As shown, the one or more ovens may be adjacent horizontal ovens. Each oven is preferably a forced convection air oven. Since it is desirable to have effective heat transfer between the fibers 208 and the air in the oven, the air circulation in each oven is preferably turbulent, and the time-averaged air velocity in each oven near the fibers 208 is preferably about 1 m / min to about 200 m / min. In the illustrated example, six adjacent horizontal ovens 212, 214, 216, 218, 220, and 222 are shown, but any suitable number of ovens can be used. The heating device may have any suitable fiber path length, and each oven may have any suitable length to provide the desired fiber path length. For example, each oven may be about 10 feet to about 16 feet (3.05 m to 4.88 m) in length. The temperature and velocity of the fibers 208 passing through the heating device 202 can be varied as needed. The path of the fibers 208 in the heating device 202 may be substantially linear, and the toughness profile of the fibers 208 during the post-drawing process can be adjusted by adjusting the speeds of various rolls or by adjusting the temperature profile of the heating device 202. Preferably, the tension of the fibers 208 in the heating device 202 is substantially constant or increases as it passes through the heating device 202. The heated fibers 224 can exit the final oven 222 and then pass through a second set of rolls 206 to form the final textile product 226. The second set of rolls 206 may be driven rolls operated to rotate at a desired speed to remove the heated fibers 222 from the heating device 202 at a desired exit speed of V2 meters / min. The second set of rolls 206 may include a plurality of individual rolls 228. The second set of rolls 206 includes a total of seven individual rolls 228, as shown in Figure 1, although the number of individual rolls 228 may be more or less depending on the desired configuration.In addition, the number of individual rolls 228 in the second set of rolls 206 may be the same as or different from the number of individual rolls 210 in the first set of rolls 204. Preferably, the second set of rolls 206 may be cooled to a temperature of at least less than about 90°C under tension necessary to maintain the orientation and shape of the final textile product 226.

[0036] An alternative heating device 300 is shown in Figure 2. As shown in the figure, the heating device 300 is a single oven The heating device 300 may be equipped with one or more ovens, such as oven 304. Each oven is preferably a forced convection air oven having the same conditions as the oven in Figure 1. Oven 304 may have any suitable length, in one example being about 10 to 20 feet (3.05 to 6.10 meters) in length. Oven 304 may include one or more intermediate rolls 302 that can change the direction in which the fibers 208 pass through the oven 304 in order to increase the path of movement of the fibers 208 within the heating device 300. Each of the one or more intermediate rolls 302 may be a stationary roll that does not rotate, a driven roll that rotates at a predetermined speed, or an idler roll that can rotate freely as the fibers 208 pass through it. In addition, each of the one or more intermediate rolls 302 may be located inside the oven 304 as shown, or one or more intermediate rolls 302 may be located outside the oven 304. The use of one or more intermediate rolls 302 increases the effective length of the heating device 300. To provide the desired total thread length, any suitable number of intermediate rolls can be utilized. The final textile product 306 is then removed from the oven, or the textile product 306 may be further stretched on additional external rolls similar to those illustrated in Figure 1. In either embodiment, the variable speed of the first set of rolls (e.g., feed roll speed, V1 (meters / min)) and the variable speed of the second set of rolls (e.g., exit roll speed, V2 (meters / min)) determine the stretch ratio (e.g., solution fiber stretching, DR1, DR2, DR3, and DR4) at each stage of the stretching process, and such stretching reduces the denier of each filament of the stretched fiber.

[0037] By producing fibers from a high IV0 UHMWPE polymer and performing steps to maintain the polymer's intrinsic viscosity during the spinning process as described above, such as sparging nitrogen into the solvent, solvent-UHMWPE polymer mixture, and / or solvent-UHMWPE polymer solution, the drawing of fibers under any of the above conditions can be limited to maintaining the filament denier at least 2.0 while simultaneously achieving a fiber toughness of 32 g / denier to 45 g / d. Such fibers have a preferred post-drawn denier (dpf) per filament in the range of about 2.0 dpf to about 7.0 dpf, more preferably about 2.3 dpf to about 6.0 dpf, more preferably about 2.5 dpf to about 5.0 dpf, and most preferably about 3.0 dpf to about 5.0 dpf. Fibers formed from filaments having denier within these ranges are maximally stretched to have an elongation at break of approximately 4.0% or less, typically between 3.0% and 4.0%, according to the ASTM D638 test method.

[0038] Once suitable fibers are produced, ropes or other multi-fiber structures may be formed from these fibers according to conventional methods in the art, for example, by twisting, braiding, entanglement, or a combination thereof, or by other conventionally known techniques for joining multiple fibers. In this regard, the ropes of the present disclosure may be any suitable structure, such as braided ropes, twisted ropes, wire-lay ropes, or parallel-core ropes. In one embodiment of the present disclosure, the elongated body consists of or is essentially made of braided, twisted, or entangled polyolefin fibers, or more preferably, braided, twisted, or entangled polyethylene fibers. In another embodiment, one or more core fibers may be further incorporated to form an elongated body in which the braided body surrounds the core fibers as a sheath.

[0039] Core-sheath braid structures are conventionally known for both rope applications. Suitable core fibers include, non-exclusively, any stretchable synthetic fiber, regenerated fiber, or metallic fiber, and optionally, ceramic or glass fiber. Particularly suitable core fibers are stretchable thermoplastic fibers, including polyolefin fibers, polyester fibers, and fluororesin fibers. When forming the core-sheath rope structures described herein, Herzog Maschinenfabrik Using conventional equipment such as braiding machines available from GmbH (Oldenberg, Germany), and using plaiting or other braiding structures, as well as core "fibers" Any conventionally known method, such as double braiding, in which the braided structure itself is used, is used to form a braided body around a core, with the core serving as the central axis. In this embodiment, preferably, for ropes with a small diameter, 2 to 100 separate fibers are incorporated into the braided sheath structure, or for ropes with a large diameter, several thousand separate fibers, for example, 5,000 to 6,000 or more separate fibers are incorporated.

[0040] In a core-sheath structure, the braided fibers and the core are optionally fused. Fusion of the braided fibers with the core is typically achieved by applying heat and tension, as described in U.S. Patents No. 5,540,990, No. 5,749,214, and No. 6,148,597, and optionally by applying a solvent or plasticizer before exposure to heat and tension, the disclosures of which are incorporated herein by reference to the extent consistent herein. As described in these patents, the braided material is subjected to stretching for a time sufficient to soften the filaments at a high temperature within the melting point range of the filament polymer material and to fuse at least partially the contact surfaces of the individual filaments forming the fiber to create a line having monofilament-like characteristics.

[0041] Fusion can also be achieved by bonding, for example, by at least partially coating the sheath and / or core fibers with a thermoplastic resin or other polymer binder material having adhesive properties. Suitable thermoplastic resins include, non-exclusively, polyolefin resins, e.g., polyolefin wax, low-density polyethylene, linear low-density polyethylene, polyolefin copolymers, ethylene copolymers, e.g., ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, polyisoprene-polystyrene block copolymer (such as KRATON® D1107, commercially available from Kraton Polymers (Houston, TX)), polyurethane, polyvinylidene fluoride, polychlorotetrafluoroethylene (PCTFE), and one or more of the aforementioned copolymers and blends. Suitable polyolefin waxes include, non-exclusively, ACumist® micronized polyolefin wax, commercially available from Honeywell International Inc. (Morristown, NJ). The most preferred thermoplastic resin is a stretchable material having a lower melting point than the specific polyolefin fiber used, and is most preferably a polyolefin resin. Alternatively, the fibers of the braided sheath may be thermally bonded to each other and / or to the core fibers without adhesive coating. The thermal bonding conditions depend on the type of fiber. The fibers may also be pre-coated with an oil, such as mineral oil, paraffin oil, or vegetable oil, as conventionally known in the art, for example, as described in U.S. Patents 5,540,990, 5,749,214, and 6,148,597. As described in the above patents, mineral oil acts as a plasticizer, improving the efficiency of the fusion process and allowing the fusion process to be carried out at lower temperatures. The fibers may be coated with oil or thermoplastic resin using any conventional method, such as dipping, spraying, or passing the fibers through a bath of the coating material by other means.

[0042] When coating the sheath and / or core fibers with a resin or other polymer binder material having adhesive properties to bond the fibers together, only a small amount of resin / binder is required. In this regard, the amount of resin / binder applied is typically 5% by weight or less based on the total weight of the fibers + resin / binder, and as a result, the fibers contain at least 95% by weight of coated fibers based on the total weight of the fibers + resin / binder. Thus, the elongated body contains at least 95% by weight of constituent fibers. In a more preferred embodiment, the elongated body contains at least about 96% by weight of fibers, more preferably 97% by weight of fibers, more preferably 98% by weight of fibers, and more preferably 99% by weight of fibers. Most preferably, the elongated body is completely resin-free, i.e., not coated with any binding resin / binder, and essentially consists of fibers / filaments. or consists of.

[0043] In the most preferred embodiment of this specification, the elongated body consists of or is essentially a braided body without incorporating core fibers, resulting in a braided rope of any diameter that is essentially free of unbraided fibers or strands. The braided body is preferably circular and has a circular, annular, or elliptical cross-section rather than a flat one, and can be formed using any conventionally known braiding technique as determined by those skilled in the art, such as plating, single braiding, solid braiding, or hollow braiding techniques. These braided bodies, which are free of core fibers, are made using conventional braiding equipment and methods. Suitable braiding equipment is commercially available, for example, from Herzog Maschinenfabrik GmbH (Oldenberg, Germany). For example, in forming a braided rope, a conventional braiding machine having multiple bobbins can be used. As is known in the art, as the bobbins move around, the fibers advance so as to weave over and under each other and are eventually collected on a winding reel. Details of the braiding machine and the formation of ropes therefrom are known in the art and are therefore not disclosed in detail herein.

[0044] Preferably, a braided body formed from multiple fibers, wherein at least one of the fibers has a filament intrinsic viscosity (IV) of 15 dl / g to about 45 dl / g when measured in decalin at 135°C. f The braided material comprises multifilament ultra-high molecular weight polyolefin fibers having ) and at least one multifilament ultra-high molecular weight polyolefin fiber having a toughness of at least 32 g / denier, a denier greater than 800, and a denier per filament greater than 2.0, and incorporates 2 to 100 distinct fibers, more preferably 3 to 40, even more preferably 3 to 20, and even more preferably 3 to 15 distinct fibers. However, as described above, more than 100 distinct fibers may be incorporated depending on the desired diameter of the rope, and potentially, depending on the denier per fiber and the desired end use, it may include thousands of distinct fibers, e.g., about 5000 to 6000 or more distinct fibers. The diameter of the fiber can be calculated from the denier of the fiber using the following formula:

[0045]

number

[0046] In the formula, density is expressed as grams per cubic centimeter (g / cm³). 3The density is (g / cc) and the diameter is mm. Ultra-high molecular weight polyethylene has a density of 0.97 g / cc, but as is known to those skilled in the art, at very high molecular weights, it can increase to about 0.98 g / cc to about 0.995 g / cc. Generally, lower fiber denier corresponds to a smaller fiber diameter. In preferred embodiments of this specification, at least one multifilament fiber forming an elongated body (e.g., a braided rope) has a denier of about 800 to about 5000, more preferably about 800 to about 4000, even more preferably about 800 to about 3000, even more preferably about 800 to about 1600, even more preferably about 900 denier or more, even more preferably 900 to about 3000, even more preferably about 900 to about 1600, even more preferably about 1000 denier or more, and even more preferably about 1000 to about 1600.

[0047] The overall denier of the elongated body / rope depends on the number of multifilament fibers combined to form the elongated body / rope, which generally depends on the requirements of the rope's end-use. The elongated body itself incorporates at least two distinct fibers, for example, a core fiber. Braids having 3 to 12 separate fibers without a fiber have a preferred denier of 1500 denier or more, more preferably more than 2300 denier, even more preferably more than 2300 to about 5000 denier, more preferably more than 2500 denier, even more preferably more than 2500 to about 5000 denier, more preferably more than 3000 denier, and even more preferably more than 3000 to about 5000 denier. Due to the braided structure in which the fibers reverse each other at intersections (i.e., picks), a 9000-meter braid incorporates more than 9000 meters of individual fibers, so the braided denier is typically greater than the total denier of all constituent fibers. In this regard, preferred ropes have a denier of at least 1500 denier, preferably 1500 to about 30,000 denier, more preferably more than about 1600 denier, more preferably about 1600 to about 26,000 denier, and even more preferably about 8,000 to about 26,000 denier. The most preferred rope has about 3 to about 50 individual fibers, preferably about 10 to about 20 individual fibers, preferably each individual fiber having a denier of over 800 denier, preferably about 900 denier or more, more preferably about 1000 denier or more, more preferably about 1100 denier or more, more preferably about 1200 denier or more, more preferably about 1300 denier or more, more preferably about 1400 denier or more, more preferably about 1500 denier or more, more preferably about 1600 denier or more, more preferably about 1700 denier or more, more preferably about 1800 denier or more, and more preferably about 1900 denier or more, and more preferably each individual fiber having a denier of about 2000 or more, and at least 3 to about 20 individual fibers, more preferably about 3 to about 15, most preferably about 5 to about 13 individual fibers incorporated into the rope (e.g., braid). The fineness of the rope depends on the required breaking strength and / or other properties determined by the desired end use.

[0048] Furthermore, any range presented using the minimum and maximum endpoints is also intended to support any range within those endpoints not explicitly described herein, and this too is within the scope of the present invention.

[0049] Optionally, fibers forming a single braid, solid braid, or hollow body may be fused together according to the above-described techniques of U.S. Patents No. 5,540,990, No. 5,749,214, and No. 6,148,597, which involve applying heat and tension to fuse the individual fibers forming the braid together. If this option is implemented, the braid may be optionally subjected to stretching at a high temperature within the melting point range of the filament polymer material, sufficient to fuse at least partially the contact surfaces of the individual filaments forming the fiber to create a line having monofilament-like characteristics. The conditions useful for the stretching / surface fusion process are the same as those listed above for core-sheath fibers. As described above with respect to core / sheath structures, fibers forming non-core / sheath braids may also be at least partially coated with either a thermoplastic resin or an oil and subsequently fused together as described above, and such coating may be applied either before or after twisting, entanglement, or braiding the fibers to form a braided / twisted / entangled structure. Suitable thermoplastic resins, waxes, and oils are the same as those described above. However, in the most preferred embodiment, the fibers forming the braid are not fused to each other, i.e., non-fused. This is distinct from the methods of U.S. Patents No. 5,540,990, No. 5,749,214, and No. 6,148,597, which fuse the fibers to each other.

[0050] After the braided body is formed, it may or may not be stretched. Stretching may be carried out with or without heating the fiber / braided body, but heating is preferred. As described herein, stretching of a braided body refers to stretching the fibers after they have been braided into a braided body, and even in the case of a non-stretched braided body, the constituent fibers forming the braided body have already been stretched during the gel / solution spinning process described above before braiding. If it is desirable to stretch the braided body with heat but not to fuse the constituent fibers of the braid, the braided body may be heated to a temperature below the melting point of the fibers. By heating to a certain temperature, fusion is avoided. For example, when incorporating ultra-high molecular weight gel-spun polyethylene multifilament fibers into a braided material, this temperature is preferably in the range of about 145°C to about 153°C, more preferably about 148°C to about 151°C. In this regard, it should be noted that highly oriented ultra-high molecular weight polyethylene fibers generally have a higher melting point than bulk UHMW PE or lower molecular weight polyethylene. During this elongation without a fusion process, the fibers are preferably held under tension that is preferably applied continuously. Preferably, the fusion-free elongation process is carried out with heat, preferably with an overall elongation ratio of about 1.01 to about 3.0, more preferably about 1.1 to about 1.8, in one or more stages of elongation.

[0051] The braided structure described herein is also referred to as braided tightness in the art. The braided body may have any desired braiding density. The angle that the braided components make with respect to the braiding axis is called the braiding angle. To increase or decrease the braiding angle along the length of the braid, the braiding density may be adjusted using a selected device as desired. In a preferred embodiment, the braided body has a braiding angle of less than about 40°, or about 5° to about 40°, more preferably 30° or less, or about 5° to about 30°, most preferably about 15° to about 30°. Each of these ranges is specific to the braiding density / tightness of the braided body, i.e., the braided body after braiding but before any additional stretching of any choice.

[0052] The multifilament fibers may optionally be twisted or air-entangled before braiding. Various methods for twisting fibers are known in the art and any of them may be used. Useful twisting methods are described, for example, in U.S. Patents 2,961,010, 3,434,275, 4,123,893, 4,819,458, and 7,127,879, the disclosures of which are incorporated herein by reference to the extent consistent herein. In preferred embodiments, the fibers are twisted to have an angle of 5° to about 40°, more preferably about 5° to about 30°, and most preferably about 15° to about 30° with respect to the twisted bundle axis. A standard method for determining the twist in the twisted fibers is ASTM D1423. Similarly, various methods for air-entangled multifilament fibers are conventionally known, for example, described in U.S. Patents No. 3,983,609, No. 4,125,922, and No. 4,188,692, and these disclosures are incorporated herein by reference to the extent consistent therewith. In preferred embodiments, the multifilament fibers are neither twisted nor air-entangled. Furthermore, before braiding multiple fibers together to form a braided body, preferably the individual fibers themselves are not braided.

[0053] Although the braided body of the most preferred embodiment comprises only multifilament polyethylene fibers having a toughness of at least 32 g / denier, the braided body may further comprise other polyolefin or polyethylene fibers having different toughnesses, including, for example, any of the fibers disclosed below: U.S. Patents No. 4,411,854, 4,413,110, 4,422,993, 4,430,383, 4,436,689, 4,455,273, 4,536,536, 4,545,950, 4,551,296, 4,584,347, 4,663,101, 5,248,471, and 5 , No. 578,374, No. 5,736,244, No. 5,741,451, No. 5,972,498, No. 6,448,359, No. 6,969,553 , No. 7,078,097, No. 7,078,099, No. 7,081,297, No. 7,115,318, No. 7,344,668, No. 7,638, Nos. 191, 7,674,409, 7,736,561, 7,846,363, 8,070,998, 8,361,366, 8,444,898, 8,506,864, and 8,747,715 are incorporated herein by reference to the extent consistent with this Specification. The braided body may also contain, as constituent fibers, other non-polyolefin fibers, such as conventionally known and commercially available aramid fibers, particularly para-aramid and meta-aramid fibers, polyamide fibers, polyester fibers including polyethylene terephthalate and polyethylene naphthalate fibers, elongated chain polyvinyl alcohol fibers, elongated chain polyacrylonitrile fibers, polybenzoazole fibers such as polybenzoxazole (PBO) and polybenzothiazole (PBT) fibers, polytetrafluoroethylene fibers, carbon fibers, graphite fibers, silicon carbide fibers, boron carbide fibers, glass fibers, regenerated fibers, metal fibers, ceramic fibers, graphite fibers, liquid crystal copolyester fibers, and other rigid rod fibers such as M5® fibers, as well as fibers formed from copolymers, block polymers, and blends of the above materials. However, not all of these fiber types are suitable for use in embodiments in which the braided body is stretched.

[0054] It should also be understood that all references herein to the term "ultra-high" with respect to the molecular weight of polyolefins or polyethylenes in this disclosure are not intended to limit the polymer viscosity and / or molecular weight to the maximum end. The term "ultra-high" is intended only to limit the useful polymers within the scope of this disclosure to the minimum end of the polymer intrinsic viscosity and / or polymer molecular weight to the extent that they can be processed into fibers having the desired properties described herein. It should also be understood that the processes described herein are most preferably applied to the processing of UHMW polyethylene, but are equally applicable to all other poly(α-olefins), i.e., UHMW PO polymers.

[0055] The elongated bodies of this disclosure may be useful in a variety of end applications, including lifting ropes, water ski ropes, climbing ropes, yacht ropes, parachute lines, fishing nets, mooring lines, ropes, shoelaces, medical applications such as catheters or dental floss, high-pressure tubing, grounding cables, and harnesses, but are particularly useful in applications requiring improved repeated bending on a sheave (CBOS) fatigue resistance as described above, including marine applications such as lifting and mooring heavy objects from the seabed.

[0056] CBOS resistance can be tested, for example, by bending the rope of this disclosure approximately 180 degrees on a free-rotating sheave or pulley. The rope is placed under load and circulated on the sheave until the rope reaches failure. In an exemplary test, the rope was bent on a sheave / pulley with a diameter of 38 mm, the D:d ratio (D = diameter of sheave / pulley, d = diameter of rope) was 20 at 56 cycles / min, and a load of 156 kg was applied to the sheave / pulley (tension of 78 kg on each side of the rope). The number of cycles until failure is typically averaged and determined, for example, based on an average of 3 to 5 tests.

[0057] (When measured in decalin at 135°C) Filament intrinsic viscosity (IV) 15 dl / g to approximately 45 dl / g f A multifiber elongated body (rope) comprising multiple multifilament ultra-high molecular weight polyolefin fibers having ), wherein each multifilament ultra-high molecular weight polyolefin fiber has a toughness of at least 32 g / denier and a denier greater than 800, and each filament has at least 2.0 denier (dpf), IV f The ratio of (dl / g) to dpf ("IV f For multifiber elongated bodies (ropes) where the ratio of dpf is between 4.0:1 and 8.0:1, and including all the narrower ranges between the above endpoints such as 4.1-7.5 and 4.2-7.0, particularly excellent CBOS fatigue resistance has been achieved. In a preferred embodiment, dpf is also IV f The product obtained by multiplying by (dl / g) ("IV f The value of ×dpf is most preferably at least 75.0, and more preferably IV in dpf.f The product obtained by multiplying by is at least between 75.0 and 110.0, and includes all narrower ranges between the above endpoints, such as 80.0 to 105.0, or 85.0 to 100.0, or 88.0 to 95.0. The most preferred polyolefin fiber type is one of these values ​​I V f ×dpf and IV f It satisfies both / dpf values. In an exemplary embodiment, each multifilament fiber of the elongated body has about 1600 denier and contains 480 filaments (i.e., dpf 3.33), and the filaments have an IV of about 22.6 dl / g to about 26.5 dl / g. f A multi-fiber elongated body having IV is formed. Therefore, in this exemplary embodiment, IV f The ×dpf value is in the range of 75.3 to 88.2, IV f The / dpf value is in the range of 6.79 to 7.96.

[0058] Furthermore, at least one polyolefin fiber in the rope is IV f ×dpf (i.e., at least 75.0 to 110.0) and / or IV f :dpf ratio(IV f As long as the above characteristics of dpf) (i.e., from 4.0:1 to 8.0:1) are satisfied, a multifiber elongated body (rope) may contain one or more highly oriented polyolefin multifilament fibers having a toughness of 45 g / d or more, for example, 45 g / denier to about 60 g / denier, but the constituent fibers of such multifilament fibers do not necessarily have a dpf of 2.0 or more or a denier of 800 or more, which is also within the scope of this disclosure.

[0059] The following non-limiting embodiments are helpful in illustrating preferred embodiments.

[0060] Example 1 A slurry was formed in a slurry tank heated to 100°C by mixing a spinning solvent and UHMW PE polymer. The UHMW PE polymer had an intrinsic viscosity IV0 of approximately 30 dl / g. A solution was formed from the slurry by heating it to at least the melting point of the UHMW PE polymer. The polymer concentration in the slurry was approximately 7%. After forming a homogeneous spinning solution, the solution was spun through a 360-hole spinneret to form multifilament solution fibers. The spinneret holes had a diameter of approximately 1 mm and a length / diameter (L / D) ratio of 15:1. The solution fibers were then passed through a 1.5-inch (3.8 cm) void and placed in a water quenching bath with a water temperature of approximately 10°C to form gel fibers. The solution fibers were stretched in a 1.5-inch void at a stretch ratio of approximately 1.5:1, and the gel fibers were cold-stretched on a set of rolls at a stretch ratio of 5.5:1 before entering the solvent removal apparatus. In a solvent removal apparatus, the solvent was extracted with an extraction solvent, and the gel fibers were stretched at a stretching ratio of approximately 1.4:1. 20 dl / g of fiber IV f The resulting dried fibers were stretched using a set of rollers to form partially oriented fibers having a toughness of approximately 24.5 g / denier. Next, the partially oriented fibers were stretched at approximately 150°C in a 22-meter oven at a fiber feed rate of approximately 12 meters / min and a take-up rate of approximately 31 meters / min to form highly oriented fibers having a toughness of over approximately 32 g / d. These fibers have a denier of 1600 and a denier per filament (dpf) of 4.4. f The level remained at 20 dl / g.

[0061] Next, twelve of these highly oriented fibers were braided together according to conventional braiding techniques to form a rope with a denier of approximately 20,000.

[0062] Example 2 and Comparative Examples 1-4 Five identical braided structures with a length:diameter (L:D) ratio of 10:1 were formed by braiding together 12 ultra-high molecular weight polyethylene fibers having the characteristics listed in Tables 1 and 2 below. No coating was applied to either the constituent fibers or the braids. The number of bending cycles until failure was determined by continuously circulating the braids on a 38 mm sheave at a bending cycle rate of 56 times per minute with a load of 78 kg applied to each end of the sample.

[0063] [Table 1]

[0064] [Table 2]

[0065] As demonstrated by the CBOS test, the braids formed from the novel fibers exhibited substantially improved abrasion resistance and durability compared to other fiber types, particularly those that did not meet the listed requirements regarding the IV:dpf ratio and the value of the IV × dpf product.

[0066] While this disclosure has been shown and described with particular reference to preferred embodiments, it will be readily apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of this disclosure. The claims are intended to be construed to encompass the embodiments of the disclosure, their substitutes described above, and all their equivalents. This specification includes the disclosure of the following inventions. [1] An elongated body comprising multiple fibers, wherein at least one of the fibers comprises a multifilament ultra-high molecular weight polyolefin fiber having a filament intrinsic viscosity (IVf) of 15 dl / g to about 45 dl / g when measured in decalin at 135°C, and the at least one multifilament ultra-high molecular weight polyolefin fiber has a toughness of at least 32 g / denier, a denier greater than 800, and a denier per filament greater than 2.0. [2] All of the fibers forming the elongated body measured at 135°C in decalin. The elongated body according to [1], comprising multifilament ultra-high molecular weight polyolefin fibers having an IVf of 5 dl / g to about 45 dl / g, a toughness of at least 32 g / denier, a denier of 900 or more, and a denier per filament greater than 2.0. [3] All of the fibers forming the elongated body are polyethylene fibers, as described in [1]. An elongated form of a slender body. [4] The aforementioned multiple fibers are twisted together, braided together, or a combination thereof. The elongated body described in [1]. [5] The ratio of denier per filament for IVf ranges from 4.0:1 to 8.0:1. The elongated body described in [1]. [6] An elongated body comprising at least one multifilament fiber containing an ultra-high molecular weight polyolefin fiber formed from a plurality of ultra-high molecular weight polyolefin filaments, wherein the ultra-high molecular weight polyolefin fiber has a filament intrinsic viscosity (IVf) of 15 dl / g to about 45 dl / g when measured in decalin at 135°C, the multifilament ultra-high molecular weight polyolefin fiber has a denier greater than 800, each filament of the multifilament ultra-high molecular weight polyolefin fiber has at least 2.0 denier, and the product of the denier per filament of the filament multiplied by the IVf of the filament is 75.0 to 110.0. [7] The elongated body according to [6], wherein the product of the denier per filament multiplied by IVf is 85.0 to 110.0. [8] The elongated body according to [6], wherein the ratio of IVf to denier per filament is from 4.0:1 to 8.0:1. [9] The elongated body according to [6], wherein the ratio of IVf to denier per filament is from 4.0:1 to 8.0:1, the product of denier per filament multiplied by IVf is at least 75.0, all of the fibers forming the elongated body have at least 900 denier, the elongated body has at least 2300 denier, and the plurality of multifilament fibers are combined in a twisted structure, a braided structure, or a combination thereof.

[10] A method for producing an elongated body, a) A step of providing a plurality of fibers, wherein at least one of the fibers comprises a multifilament ultra-high molecular weight polyolefin fiber having a filament intrinsic viscosity (IVf) of 15 dl / g to about 45 dl / g when measured in decalin at 135°C, and the at least one multifilament ultra-high molecular weight polyolefin fiber has a toughness of less than 32 g / denier, a denier greater than 800, and a denier per filament greater than 2.0, b) A step of stretching each multifilament fiber to increase the toughness of the fiber to at least 32 g / denier, wherein the denier per filament remains greater than 2.0, c) Optionally, a step of coating at least a portion of each fiber with either a thermoplastic resin or an oil, d) A step of twisting, entangling, or braiding the fibers to form an elongated structure, e) A method comprising the optional step of heating and stretching the elongated structure to thermoset the fibers of the elongated structure.

Claims

1. An elongated body comprising multiple multifilament fibers, each containing a multifilament fiber formed from multiple ultra-high molecular weight polyolefin filaments, wherein the multifilament fiber has an intrinsic viscosity (IV) of 15 dl / g to 45 dl / g when measured in decalin at 135°C. ｆ ) and the multifilament ultra-high molecular weight polyolefin fiber has a denier of more than 800, and each filament of the multifilament ultra-high molecular weight polyolefin fiber has at least 2.0 denier, and the denier per filament of the filament is IV of the filament ｆ An elongated body whose product when multiplied by is between 88.0 and 95.

0.

2. IV ｆ The elongated body according to claim 1, wherein the ratio of denier per filament is from 4.0:1 to 8.0:

1.

3. The aforementioned IV ｆ The elongated body according to claim 1, wherein the ratio of denier per filament is between 4.0:1 and 8.0:1, all of the fibers forming the elongated body have at least 900 denier, the elongated body has at least 2300 denier, the plurality of multifilament fibers are combined in a twisted structure, a braided structure, or a combination thereof, and the elongated body is a rope.

4. A method for producing an elongated body, a) A step of providing a plurality of fibers, wherein the fibers have a filament intrinsic viscosity (IV) of 15 dl / g to 45 dl / g when measured in decalin at 135°C. ｆ A step of providing a multifilament ultra-high molecular weight polyolefin fiber having ) and wherein the multifilament ultra-high molecular weight polyolefin fiber has a toughness of less than 32 g / denier, a denier of more than 800, and a denier per filament of more than 2.0, b) A step of stretching each multifilament fiber to increase the toughness of the fiber to at least 32 g / denier, wherein the denier per filament remains greater than 2.0, c) Optionally, a step of coating at least a portion of each fiber with either a thermoplastic resin or an oil, d) A step of twisting, entangling, or braiding the fibers to form an elongated structure, The IV of the aforementioned elongated structure ｆ The ratio of denier per filament is from 4.0:1 to 8.0:1, and the ratio of denier per filament of the elongated structure to the IV of the filament ｆ A method in which the product obtained by multiplying by is between 88.0 and 95.0.

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