UHMWPE filaments, yarns and articles thereof

Abstract

Disclosed herein are gel spun ultra high molecular weight polyethylene (UHMWPE) polyethylene filaments of ultra high molecular weight optimized for permanent load applications. Also disclosed is a yarn comprising at least 25 permanently load optimized UHMWPE filaments, a denier of at least 50 dtex, a filament denier of at least 0.50 dtex, a tensile modulus of at least 1500 cN / dtex, and a minimum creep rate of at most 5.0 x 10-7 s-1 measured at 70 DEG C under a load of 400 MPa. The UHMWPE may be a linear homopolymer of ethylene. Load optimized filaments and various products comprising the filaments or yarns, such as cords, nets, medical devices, fabrics, laminates, composite articles, and ballistic resistant articles, are also disclosed.

Description

[0001] This invention relates to gel-spun ultra-high molecular weight polyethylene filaments optimized for permanent load applications, yarns comprising at least 25 permanent load-optimized filaments, load-optimized filaments, and various products comprising said filaments or yarns, such as ropes, nets, medical devices, fabrics, laminates, composites, and bulletproof products.

[0002] Over the past few decades, numerous research projects have focused on improving the creep properties of synthetic yarns, as these yarns are well-suited for a wide range of applications where lightweight and strength are driving factors. One example of a synthetic yarn is UHMWPE yarn, which has successfully met the weight and strength requirements of a variety of applications. The almost unparalleled strength of UHMWPE yarn, combined with its UV resistance, chemical resistance, cut and abrasion resistance, and other favorable properties, is why these yarns were almost immediately adopted for applications such as rope mooring, composite reinforcement, medical devices, and cargo nets.

[0003] However, UHMWPE filaments and yarns have a drawback that hinders their optimal utilization in long-term applications, which is related to their creep behavior. It has been observed that the final failure mode of systems using UHMWPE filaments (especially those subjected to long-term loads) includes cracking or failure due to creep. Therefore, such systems (especially those designed for long-term or ultra-long-term use) must be over-designed to last for many years, such as more than 10 years, and in some cases even more than 25 years. In the field of low-creep UHMWPE yarns, more than a decade of development has focused on reducing the creep rate (CR) of UHMWPE fibers and yarns, and more recently on increasing the creep life (CLT) of UHMWPE fibers and yarns.

[0004] For example, WO 2009 / 043597 relates to a method for producing gel-spun fibers from ultra-high molecular weight polyethylene (UHMWPE) and fibers with high tensile strength and improved creep. UHMWPE yarns with a combination of creep rate and strength are disclosed, for example, a creep rate of up to 5 × 10⁻⁶ measured at 70°C under a load of 600 MPa. -7 s -1 And a tensile strength of at least 4 GPa. The method described in WO2009 / 043597 uses UHMWPE copolymers with a Δδ of up to 42° and employs a high draw ratio in the air gap, gel phase and dry yarn.

[0005] WO2012 / 139934 relates to creep-optimized ultra-high molecular weight polyethylene (UHMWPE) fibers, methods for producing the same, and various products comprising said UHMWPE fibers, such as ropes, nets, medical devices, fabrics, laminates, composites, and bulletproof products. Fibers comprising UHMWPE containing ethyl and butyl side chains are disclosed, and the UHMWPE has a creep life of up to 500 hours and a tensile strength of up to 4.1 GPa, measured at 70°C under a load of 600 MPa.

[0006] WO2018 / 060127 describes gel-spun fibers comprising ultra-high molecular weight polyethylene (UHMWPE), wherein the UHMWPE has an intrinsic viscosity (IV) of at least 4 dL / g and contains at least 0.3 short chain branches per thousand total carbon atoms, characterized in that, based on 100 parts by weight of the polyethylene forming the fiber, the fiber further comprises 0.1 parts by weight to 10 parts by weight of carbon black.

[0007] While the yarns described in the prior art exhibit very good creep life and / or creep rate, further optimization of yarn performance still appears necessary. This is particularly relevant for applications that apply not only permanent loads but also dynamic loads that are often accompanied by varying loads. Such challenging applications are found, for example, in tension leg platforms (TLPs) and other applications in floating offshore wind turbines. As wind turbine heights and blade diameters increase, suitable locations become increasingly remote from shore and at greater water depths. To meet these increasing demands, current commercial tendon solutions require a high yarn density, also known as linear density, per meter.

[0008] Patent publication WO2016001158 describes a structure comprising rigid elements connected together by interconnecting elements to form a statically deterministic or statically superdeterministic structure, wherein the structure includes at least one tensile element, the tensile element comprising a stable creep of at least 0.3% and at most 10% and less than 1 × 10⁻⁶. -5 The minimum creep rate of polymer fibers is % / second, and the stable creep and minimum creep are measured under a tension of 900 MPa and a temperature of 30°C.

[0009] Therefore, this invention aims to provide advantages and / or alternatives compared to known multifilament yarns. In particular, this invention aims to provide a multifilament yarn and filament with optimized performance for various applications in a variety of technical fields. Another object of this invention is to provide multifilament yarns and filaments with higher breaking strength per filament than known yarns and filaments. A specific object of this invention is to provide yarns and filaments having properties that allow for the design of load-bearing cables for tension leg platforms to meet load and life expectations while reducing the required mass of UHMWPE yarns or filaments in the load-bearing cable, or to provide a yarn or filament that allows for the construction of ribs with significantly higher load capacity and life expectations compared to prior art materials.

[0010] This objective is surprisingly achieved through ultra-high molecular weight polyethylene (UHMWPE) multifilament yarn having a fineness of at least 50 dtex, at least 25 filaments, a filament fineness of at least 0.50 dtex, a tensile modulus of at least 1500 cN / dtex, and a tensile modulus of at most 5.0 × 10⁻⁶ when measured at 70°C under a load of 400 MPa. -7 s -1 The minimum creep rate, wherein the ultra-high molecular weight polyethylene is a linear homopolymer of ethylene.

[0011] As will be provided in more detail in the embodiments, the yarns of the present invention are best suited for use as catenaries in tension leg platforms, thereby providing catenary designs with significantly lower linear density and therefore lower total catenary mass. This effect is surprising and contrary to the general teachings in the prior art, which emphasize the need for even lower minimum creep rates and creep lives. In contrast, the inventors have found that the HMPE yarns and filaments according to the present invention are substantially more suitable when used in more complex applications where the yarn or filament is subjected to various conditions, such as permanent loads, bending, peak loads varying at low or high frequencies, etc. In particular, such complex applications can be found in tension legs, rigging, umbilical cables, deep-sea cables, and composite structures such as unidirectional sheets, laminates, and fabrics. Attached Figure Description

[0012] Figure 1 The apparatus used to determine the creep rate (CR) and creep lifetime (CLT) of multifilament yarn is schematically shown.

[0013] Figure 2 This is a creep life graph recorded during creep life measurement. The plotted graphs are for illustrative purposes only and do not show the curves of the yarn according to the invention.

[0014] Figure 3 An apparatus for determining filament properties such as linear density, tensile modulus, and toughness is schematically depicted.

[0015] Figure 4 A tension leg platform according to the invention is schematically depicted, comprising a float (100) and a mooring article (401) according to the invention, the mooring article being arranged to connect the float to the seabed (402). Summary of the Invention

[0016] Multifilament yarn is understood herein as an elongated body comprising multiple filaments, i.e., containing at least 25 individual filaments, preferably at least 50, and more preferably at least 100 individual filaments. The filaments typically represent the main component of the yarn, but may also contain other materials (e.g., in the form of coatings or finishing agents) to, for example, adjust the yarn's mechanical or other properties. The filaments in the yarn are typically oriented parallel to each other in a side-by-side manner. Typically, the filaments in the yarn are untwisted, but may also be slightly twisted together. Therefore, the yarn twist can range from 0 rpm to 10 rpm or more.

[0017] Filament is understood herein as an elongated body whose length dimension is much greater than its width and thickness or diameter transverse dimensions. Typically, filament is referred to as having a continuous length. In the context of this invention, filament may also be referred to as fiber. In the context of this invention, the form factor of chopped fibers with discontinuous lengths, as recognized in the art, is not considered a filament. Filament can have a regular or irregular cross-section, typically circular, but can also be polygonal, elliptical, or oblong. In particular, the shape of the cross-section may be altered by processing conditions once it is processed into an article. The yarn used for the purposes of this invention is an elongated body comprising multiple filaments.

[0018] The multifilament yarns and filaments of the present invention are ultra-high molecular weight polyethylene filaments, also known in the art as high performance polyethylene (HPPE) yarns or filaments, or high modulus polyethylene (HMPE) yarns or filaments. UHMWPE, HPPE, or HMPE yarns and filaments are known in the art to possess high toughness, where the relative term "high" is used to contrast the toughness with that of other synthetic or natural materials. This naming is widely accepted in the field of UHMWPE yarns and filaments.

[0019] In a preferred embodiment, the ultra-high molecular weight polyethylene multifilament yarn has a maximum density of 2.5 × 10⁻⁶. -7 s -1 Minimum creep rate CR 70 / 400More preferably up to 1.5 × 10 -7 s -1 Minimum creep rate CR 70 / 400 And most preferably at most 1.0 × 10 -7 s -1 Minimum creep rate CR 70 / 400 This lower creep rate will show further advantages in the applications discussed.

[0020] When the CR mentioned above 70 / 400 When measured under specific conditions, the creep life of the invented yarn can reach or exceed 10 years. 6 The time interval is seconds, corresponding to test durations of several days to several weeks. Therefore, alternative creep measurement conditions can be chosen to characterize the creep properties of the filament more quickly, i.e., by increasing the applied load to 1200 MPa at the same temperature.

[0021] Therefore, another embodiment of the present invention relates to a multifilament yarn having a fineness of at least 0.50 dtex, at least 25 filaments, a filament fineness of at least 0.50 dtex, a tensile modulus of at least 1500 cN / dtex, and a tensile modulus of at most 5.0 × 10⁻⁶. -5 s -1 The minimum creep rate (measured at 70°C and 1200 MPa load, CR) 70 / 1200 ), where modulus and CR 70 / 1200 The measurement is performed according to the corresponding method described in the "Method". Preferably, the multifilament yarn has a maximum density of 2.5 × 10⁻⁶. -5 s -1 CR 70 / 1200 More preferably up to 1.5 × 10 -5 s -1 CR 70 / 1200 And most preferably at most 1.0 × 10 -5 s -1 CR 70 / 1200 .

[0022] In a preferred embodiment, the multifilament yarn of the present invention has a modulus of at least 1600 cN / dtex, more preferably at least 1700 cN / dtex, even more preferably at least 1750 cN / dtex, even more preferably at least 1800 cN / dtex, and most preferably at least 1850 cN / dtex. While there is no theoretical maximum value for the stiffness (i.e., tensile modulus) of the multifilament yarn, the practical upper limit tensile modulus can be as high as 2500 cN / dtex. The inventors have found that as the tensile modulus of the yarn increases, the mechanical properties of the articles made from it are further improved. In particular, it has been observed that the mass of the multifilament yarn in tension legs or unidirectional sheets can be further reduced while maintaining the specified properties of the articles.

[0023] The yarn of the present invention preferably has a toughness of at least 42.0 cN / dtex, preferably at least 44.0 cN / dtex, more preferably at least 46.0 cN / dtex, even more preferably at least 47.0 cN / dtex, and most preferably at least 48.0 cN / dtex. Those skilled in the art will recognize that the toughness of UHMWPE multifilament yarns has theoretical and practical limitations; therefore, the polyethylene filament preferably has a toughness of at most 70 cN / dtex, preferably at most 65 cN / dtex, and more preferably at most 60 cN / dtex.

[0024] The yarn according to the invention should be understood as an elongated body comprising a plurality of filaments. Therefore, the invention also relates to a yarn having a fineness preferably from 50 dtex to 10,000 dtex, more preferably from 100 dtex to 8,000 dtex, and most preferably from 200 dtex to 5,000 dtex. It has been found that yarns with lower fineness (also known as linear density) have reduced robustness and make them less suitable for processing into finished or semi-finished products. Yarns with excessively low fineness are prone to breakage due to low breaking strength. Preferably, the yarn of the invention has a plurality of filaments of at least 50, more preferably at least 100, even more preferably at least 160, and most preferably at least 240. Those skilled in the art will recognize that there is no theoretical limit to the number of filaments forming the yarn, but the actual limit may be imposed by the manufacturing process. Therefore, the yarn preferably has a maximum number of filaments of up to 100,000, more preferably up to 50,000, and most preferably up to 10,000 per yarn.

[0025] Although one embodiment of the invention relates to a multifilament yarn having a fineness of at least 50 dtex, at least 25 filaments, a filament fineness of at least 0.50 dtex, a tensile modulus of at least 1500 cN / dtex, and a tensile modulus of at most 5.0 × 10⁻⁷ when measured at 70°C under a load of 400 MPa.-7 s -1 Minimum creep rate (CR) 70,400 The ultra-high molecular weight polyethylene (UHMWPE) is a linear homopolymer of ethylene. Another embodiment of the invention relates to filaments, also known as monofilaments, that can form the yarn of the invention. These filaments can be separated from the yarn or other products obtained by processing the yarn using methods known to those skilled in the art. Depending on the properties and composition of the product, separation can be achieved by mechanical or physical treatment of the product, such as unwinding, untwisting, removing foreign components by dissolution, filtration, sieving, etc.

[0026] The filaments of the present invention may have mechanical properties that differ in absolute value from those of the yarns or other articles formed from them. This is, for example, in strength measurements, where the strength of a yarn is not the sum or average of the strengths of the individual filaments it comprises. Similarly, the strength of a rope is not the sum or average of the strengths of the individual yarns or filaments that make up the rope. This loss of efficiency will be familiar to those skilled in the art when assembling filaments into yarns and yarns into yarn components. WO2005066401 indicates the dependence of tensile strength on the number of aggregated filaments. Therefore, the present invention also relates to the filaments of the present invention having their own individual mechanical properties.

[0027] Therefore, one embodiment of the present invention relates to a filament suitable for use in the multifilament yarns of the present invention or other applications mentioned herein, wherein the filament has a fineness (also known as linear density) of at least 0.50 dtex, a modulus of at least 1700 cN / dtex, and a modulus of at most 1.0 × 10⁻⁶. -7 s -1 The creep rate (measured at 70°C and 400 MPa load, CR) 70 / 400 ), wherein the modulus and CR of the filament 70 / 400 The measurement is performed according to the corresponding method described in the "Method". Preferably, the filament has a maximum diameter of 8.0 × 10⁻⁶. -8 s -1 CR 70 / 400 More preferably up to 6.0 × 10 -8 s -1 CR 70 / 400 And most preferably at most 4.0 × 10 -8 s -1 CR 70 / 400 The theoretical lower limit of the creep rate of UHMWPE filaments corresponds to the absence of creep under relevant test conditions; therefore, the lower limit of the minimum creep rate of the filaments can be as low as 1.0 × 10⁻⁶. -10 s -1 Or even as low as 1.0×10 -12 s-1 .

[0028] The CR mentioned above 70 / 400 Under measured conditions, the creep life of the filaments of the present invention can reach or exceed 10 years. 6 Seconds correspond to test durations of several weeks or longer. Therefore, alternative creep measurement conditions can be chosen to characterize the creep properties of the filament more quickly, i.e., by increasing the applied load to 1200 MPa at the same temperature.

[0029] Therefore, another embodiment of the invention relates to a filament suitable for use in the multifilament yarns of the present invention or other applications mentioned herein, wherein the filament has a fineness of at least 0.50 dtex, a modulus of at least 1700 cN / dtex, and a modulus of at most 1.0 × 10⁻⁶. -5 s -1 The creep rate (measured at 70°C and 1200 MPa load, CR) 70 / 1200 ), wherein the modulus and CR of the filament 70 / 1200 The measurement is performed according to the corresponding method described in the "Method". Preferably, the filament has a maximum diameter of 8.0 × 10⁻⁶. -6 s -1 CR 70 / 1200 More preferably up to 6.0 × 10 -6 s -1 CR 70 / 400 And most preferably at most 4.0 × 10 -6 s -1 CR 70 / 400 .

[0030] In a preferred embodiment, the filament of the present invention has a modulus of at least 1750 cN / dtex, more preferably at least 1800 cN / dtex, even more preferably at least 1850 cN / dtex, and most preferably at least 1900 cN / dtex. While there is no theoretical maximum value for the stiffness (i.e., tensile modulus) of UHMWPE filaments, the practical upper limit tensile modulus can be as high as 2500 cN / dtex. In the context of this application, the modulus of the filament (also referred to as the tensile modulus or stiffness of the filament) is measured as a tangential modulus of 10 cN / dtex to 15 cN / dtex, as further described in the “Method”. The inventors have found that as the tensile modulus of the filament increases, the mechanical properties of the articles made from it are further improved. In particular, while maintaining the specified properties of the article, the linear or areal density of the filament required in tension legs or unidirectional sheets can be further reduced.

[0031] In another preferred embodiment of the invention, the UHMWPE filament has a toughness of at least 4.50 N / tex, preferably at least 4.75 N / tex, more preferably at least 5.00 N / tex, even more preferably at least 5.25 N / tex, and most preferably at least 5.50 N / tex, as measured according to the "Method". Those skilled in the art will recognize that there are theoretical and practical limitations to the toughness of the UHMWPE polyethylene filament, and therefore the polyethylene filament can preferably have a toughness of up to 8.00 N / dtex.

[0032] Furthermore, it has been observed that the yarn of the present invention can be obtained using filaments with an unexpectedly high linear density. This advantage is surprising and contrary to methods in the prior art, where improvements in yarn and product are typically achieved by increasing the draw ratio, resulting in filaments and yarns with even lower linear densities. For example, the optimal yarn disclosed in WO 2009 / 043597 has a fineness as low as 85 dtex for a 390 filament yarn. Using filaments with high linear density and their corresponding yarns allows for optimization of various yarn properties, such as filament breakage, yarn productivity, and ballistic resistance. Therefore, from the viewpoint of yarn productivity and applicability, it is desirable to have yarns with good creep properties, high modulus, and containing high linear density filaments. To the inventors' knowledge, this invention provides such a yarn for the first time. Therefore, a preferred embodiment of the invention relates to filaments and yarns comprising such filaments, having a linear density of at least 0.60 dtex, preferably at least 0.70 dtex, more preferably at least 0.80 dtex, even more preferably at least 0.90 dtex, and most preferably at least 1.0 dtex. Yarns or articles comprising filaments with very low linear density have many disadvantages. The yarns and articles exhibit particularly lower robustness because the filaments have reduced breaking strength and deteriorate more rapidly during the manufacture and handling of the yarns or articles. At a given filament count, the low linear density of the filaments will result in low-count yarns, making them unsuitable for certain applications. This deficiency can be compensated for by increasing the number of filaments in the yarn or by increasing the number of yarns with said low linear density to achieve the desired linear or areal density of the final article. However, this would shift the described problems to the manufacturing process, where the lower breaking strength and higher number of filaments during the spinning process make the process less robust and cumbersome. In short, it can be said that the lower limit of the filament linear density mentioned above is caused by the economics and technology of the current manufacturing process and its robustness in application.

[0033] The filaments of the present invention and the filaments present in the yarns of the present invention can have a linear density (typically also referred to as fineness) of up to 6.0 dtex, preferably up to 5.0 dtex, more preferably up to 4.0 dtex, even more preferably up to 3.0 dtex, and most preferably up to 2.5 dtex. It has been observed that filaments with lower fineness are particularly suitable for the construction of unidirectional sheets or fabrics, resulting in more uniform constructions.

[0034] The UHMWPE present in the multifilament yarns and filaments of this invention is an ultra-high molecular weight polyethylene with an intrinsic viscosity (IV) of at least 10 dL / g. IV is determined at 135°C in a solution of decahydronaphthalene in UHMWPE according to ASTM D1601 (2004), as further described in the method. Preferably, IV is 10 to 50 dL / g, more preferably 12 to 40 dL / g, and most preferably 15 to 35 dL / g, to provide fibers, yarns, and articles with optimal mechanical properties.

[0035] Therefore, the multifilament yarn or filament of the present invention is a multifilament yarn or filament gel-spun yarn or gel-spun filament comprising ultra-high molecular weight polyethylene (UHMWPE) having the characteristic viscosity described above.

[0036] The UHMWPE present in the multifilament yarns and filaments of this invention is characterized as a linear homopolymer of ethylene. However, it may further contain very small amounts of side chains (e.g., side chains in the form of short-chain branches) derived from the comonomers present in the UHMWPE. In this document, "very small amounts of comonomers" should be understood as the comonomers and the resulting short-chain branches being close to or below the current detection limits further defined below. The short-chain branches may originate from impurities present, for example, in the raw materials or manufacturing process, or may be added in very small amounts during manufacturing. In this document, the comonomers are preferably selected from α-olefins having at least 3 carbon atoms, cyclic olefins having 5 to 20 carbon atoms, and straight-chain, branched, or cyclic dienes having 4 to 20 carbon atoms. α-olefins refer to olefins with terminal unsaturation having 3 or more carbon atoms, preferably 3 to 20 carbon atoms. Preferred α-olefins include straight-chain monoolefins, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and 1-decene; branched monoolefins, such as 3-methyl-1-butene, 3-methyl-1-pentene, and 4-methyl-1-pentene; and vinylcyclohexane, etc. α-olefins can be used alone or in combination of two or more.

[0037] In a preferred embodiment, the α-olefin has 3 to 12 carbon atoms. Even more preferably, the α-olefin is selected from the group consisting of propylene, 1-butene, 1-hexene, and 1-octene. Most preferably, propylene, 1-butene, and 1-hexene are present as comonomers in UHMWPE. The applicant has found that, according to the present invention, these α-olefins can be readily copolymerized and can exhibit the strongest effect in optimizing creep life performance.

[0038] In the context of this invention, short-chain branches can be distinguished from long-chain branches, which are defined herein as branches containing more than 20 carbon atoms, but typically have significantly longer lengths, reaching the size of a polymer chain and producing branched polymer structures, such as branches of polymer chains arranged in Y, H, or E configurations. Polymers that substantially do not have long-chain branches are generally referred to as linear polymers. In the context of this invention, UHMWPE is linear polyethylene having less than 1 long-chain branch per 1000 total carbon atoms, preferably less than 0.2 long-chain branches per 1000 total carbon atoms, even more preferably less than 0.1 long-chain branches per 1000 total carbon atoms, and most preferably without a long chain branch (LCB), wherein the absence of an LCB can be defined as below the common detection limit.

[0039] As is well known from the literature, the presence of short-chain and long-chain branches (referred to herein as side chain branches, SCBs) in UHMWPE significantly improves creep behavior, particularly by reducing the minimum creep rate and increasing creep life. The inventors have found that, for the invention described herein, this improvement impairs the manufacturing process of filaments and yarns, particularly their stretchability. A direct result of the presence of branches is a reduction in achievable strength properties, particularly the modulus of the fiber. Therefore, the branching in UHMWPE affects the mechanical properties of creep rate and modulus in an opposite manner, and it is a wise choice to trade off the reduction in strength properties for an improvement in creep rate. The inventors have found that, in a preferred embodiment of the invention, the UHMWPE present in the filaments and multifilament yarns of the invention may contain up to 0.10 side chain branches per thousand total carbon atoms (SCB / 1000TC), more preferably up to 0.08 SCB / 1000TC, even more preferably up to 0.05 SCB / 1000TC, and most preferably no detectable side chain branches. The lower limit of side chain branching in UHMWPE is defined by its absence, i.e., 0.0 side chain branches per 1000 carbon atoms. However, in the context of this invention, the absence of side chain branching will be defined as a detection limit below 0.05 SCB / 1000TC, preferably below 0.03 SCB / 1000TC. Further details regarding SCB measurement are given in the "Methods" section.

[0040] The branching characteristics of UHMWPE in filaments described above contrast with previously cited literature on low-creep products (e.g., WO 2009 / 043597), which describes yarns and filaments made from UHMWPE having both short-chain and long-chain branches. The UHMWPE in this literature is characterized by a Δδ value of 42° or less. Therefore, the UHMWPE present in the filaments of this invention can be defined as a linear polyethylene homopolymer without both long-chain and short-chain branches, or at least with side chain branches below the limits mentioned above or even below the current detection limits. Preferably, the UHMWPE of this invention has less than 0.10 methyl end groups per thousand carbon atoms derived from the combination of said long-chain and short-chain branches, more preferably less than 0.08 methyl end groups per thousand carbon atoms, and even more preferably less than 0.05 methyl end groups per thousand carbon atoms. Alternatively, the linear polyethylene homopolymer of the present invention, which may contain very small amounts of long-chain and short-chain branches as described above, can be defined as having a Δδ value of at least 45°, preferably at least 46°, even more preferably at least 47°, and still more preferably at least 48°, wherein the Δδ value and / or methyl end groups are characterized according to the corresponding method in WO 2009 / 043597. While the Δδ value of fully linear UHMWPE may depend on other polymer properties, the upper limit for the Δδ value of UHMWPE present in filaments can be 55°, preferably 60°.

[0041] According to the present invention, the UHMWPE filaments and yarns of the present invention are obtained by a gel spinning method. For the purposes of this invention, a gel spinning method refers to a method comprising at least the following steps: (a) dissolving polyethylene in a solvent to form a polymer solution with a UHMWPE concentration of 2 to 40 wt%, (b) passing the polymer solution through a porous template to spin a solution filament, (c) cooling the solution filament to below 80°C to form a gel filament, (d) stretching the filament in at least one step to form a stretched filament, and (e) removing at least a portion of the solvent before, during, or after stretching. The gel spinning method may optionally include more than one stretching step, wherein the gel filament and / or solid filament are stretched at a certain stretch ratio. Gel spinning methods are known in the art and are disclosed, for example, in WO 2005 / 066400, EP 1,699,954, and "..." Advanced Fiber Spinning Technology In Ed. T. Nakajima, Woodhead Publ. Ltd (1994), ISBN 185573 182 7, these publications and the references cited therein are included in this document by reference.

[0042] According to the present invention, the gel spinning method can be used to manufacture the UHMWPE filaments and yarns of the present invention, wherein, as mentioned above, ultra-high molecular weight polyethylene (UHMWPE) is used to produce a UHMWPE solution, which is then spun through a spinneret and the resulting gel fibers are dried to form solid fibers.

[0043] The UHMWPE solution is preferably prepared with a UHMWPE concentration of at least 2 wt%, more preferably at least 3 wt%. Preferably, the concentration of UHMWPE in the solvent is 3 to 25 wt%, more preferably 4 to 12 wt%. Preferably, the concentration of UHMWPE in the UHMWPE composition is 3 to 25 wt%, preferably in the range of 8 to 50 dL / g, and more preferably 12 to 40 dL / g.

[0044] To prepare UHMWPE solutions, any known solvent suitable for gel spinning UHMWPE can be used. Such solvents are also referred to herein as “spinning solvents.” Suitable examples of solvents include aliphatic and alicyclic hydrocarbons, such as octane, nonane, decane, and alkanes, including their isomers; petroleum fractions; mineral oils; kerosene; aromatic hydrocarbons, such as toluene, xylene, and naphthalene, including their hydrogenated derivatives, such as decahydronaphthalene and tetrahydronaphthalene; halogenated hydrocarbons, such as monochlorobenzene; and cycloalkanes or cycloalkenes, such as careen, fluorine, camphene, menthane, dipentene, naphthalene, acenaphtalene, methylcyclopentadiene, tricyclodecane, 1,2,4,5-tetramethyl-1,4-cyclohexadiene, fluorenone, naphtindane, tetramethyl-p-benzodiquinone, ethylfluorene, fluoranthene, and cycloalkanones. The combinations of solvents listed above can also be used for gel spinning of UHMWPE; for simplicity, these combinations are also referred to as solvents. In a preferred embodiment, the selected solvent is non-volatile at room temperature, such as paraffin oil. The method of the present invention has also been found to be particularly advantageous for solvents that are relatively volatile at room temperature (e.g., decahydronaphthalene, tetrahydronaphthalene, and kerosene fractions). In the most preferred embodiment, the selected solvent is decahydronaphthalene.

[0045] The UHMWPE solution is then spun into gel filaments by passing it through a perforated template (also called a spinneret). The perforated template is understood herein to be a spinneret comprising preferably at least 100, even more preferably at least 300, and most preferably at least 500 spinning orifices. Preferably, the spinning temperature is between 150°C and 300°C, more preferably, the temperature is selected to be below the boiling point of the spinning solvent. If the dissolution temperature in the extruder is higher than the boiling point, the UHMWPE solution may need to be cooled to a suitable spinning temperature. If, for example, decahydronaphthalene is used as the spinning solvent, the spinning temperature is preferably at most 190°C.

[0046] In a preferred embodiment, each spinning orifice of the template has a geometry including at least one shrinkage zone. The shrinkage zone is understood herein as a region with a gradually decreasing diameter, from an initial diameter D0 to a final diameter D. n The cone angle is preferably less than 60°, thereby achieving the required draw ratio (DR) in the spinning plate within the spinning holes. sp Preferably, the spinning orifice also includes a constant diameter region upstream and / or downstream of the shrinkage zone.

[0047] Preferably, the multifilament yarn enters the air gap from the spinning orifice and then enters the quenching zone, the length of which is preferably 1 mm to 20 mm. Although referred to as an air gap, the gap can be filled with any gas or gas mixture, such as air, nitrogen, or other inert gases. The air gap is understood herein as the distance between the spinning plate and the quenching zone. The quenching zone can be a bath containing a liquid (e.g., water) at a temperature below the spinning temperature (e.g., about room temperature). Preferably, the draw ratio DR in the air gap is 2 to 20, more preferably 4 to 15, and most preferably 5 to 10. ag (Commonly referred to in the art as draw ratio) Stretched multifilament yarn. The inventors discovered that, in order to produce the filaments and yarns of the present invention with an optimized balance of physical and mechanical properties, they had to deviate from conventional practices in the decahydronaphthalene spinning method and employ a high draw ratio in the air gap. In contrast, the challenge is to optimize DR... ag This is achieved by sufficiently reducing the diameter of the gel filaments used to achieve optimal cooling in the quenching bath, while maintaining a sufficiently high gel filament diameter, thereby obtaining filaments with high linear density and optimized modulus and creep rate. This optimal value demonstrates beneficial effects on the creep properties of the yarns and filaments of the present invention.

[0048] Gel filaments formed by spinning a UHMWPE solution through a spinneret can be extruded into an air gap and then enter a cooling zone (also known as a quench bath or quenching zone), where they are cooled to below 80°C to form gel fibers or gel filaments and picked up on a first driven roller. In the cooling zone, the gel filaments are preferably cooled in an airflow and / or in a liquid bath.

[0049] After the gel filaments are formed, they are subjected to a solvent extraction step, wherein at least part of the spinning solvent used to produce the UHMWPE solution is removed from the gel filaments to form solid filaments. The solvent removal process can be carried out by known methods, such as by evaporation when using a relatively volatile spinning solvent (e.g., decahydronaphthalene), or by using an extractant (e.g., when paraffin is used as the spinning solvent), or by a combination of both. Preferably, the gel filaments are stretched at a draw ratio of at least 1.2, more preferably at least 1.5, and most preferably at least 2.0.

[0050] The manufacturing method further includes stretching the filament before, during, and / or after the solvent removal. Preferably, the stretching of the filament after solvent removal is carried out in at least one stretching step, with a stretch ratio of at least 3, more preferably at least 4, and most preferably at least 5. More preferably, the stretching of the filament is carried out in at least two steps, or even in at least three steps. Preferably, each stretching step is carried out at a different temperature, preferably selected to achieve the desired stretch ratio without filament breakage. Preferably, stretching is carried out in more than two steps, and if UHMWPE is used, stretching is preferably carried out at different temperatures with an increasing distribution from about 120°C to 155°C. If the stretching of the solid filament is carried out in more than one step, the draw ratio (DR) is calculated by multiplying the stretch ratio achieved by each individual solid stretching step. 固体 .

[0051] Preferably, the overall draw ratio (i.e., the total draw ratio experienced by the filament throughout its manufacturing process) is at least 20, more preferably at least 25, even more preferably at least 30, and most preferably at least 40. It has been observed that by increasing the overall draw ratio, the mechanical properties of the yarn of the present invention are improved. In particular, tensile strength and modulus increase.

[0052] The gel-spun filaments or yarns comprising gel-spun filaments of the present invention are filaments and yarns suitable for typical filament and yarn applications. Therefore, one embodiment of the invention relates to an article comprising multifilament yarns or filaments according to the invention, preferably selected from the group consisting of yarns, ropes, cables, nets, fabrics, and protective equipment (e.g., bulletproof articles).

[0053] The UHMWPE filaments or yarns of the present invention possess properties that make them an interesting material for ropes, cables, etc., preferably designed for ropes used in heavy-duty operations (e.g., marine, industrial, and offshore operations). Rigging ropes and ropes for sports applications (e.g., yachting, rock climbing, kite flying, skydiving, etc.) are also applications where the filaments and yarns of the present invention perform well. In particular, the UHMWPE filaments of the present invention have been observed to be especially suitable for long-term and ultra-long-term heavy-duty operations.

[0054] Heavy-duty operations can also include, but are not limited to, crane ropes, ropes for deep-sea deployment or retrieval of hardware, anchor handling, mooring of support platforms for offshore renewable energy generation, and mooring of offshore oil drilling platforms and production platforms (such as offshore production platforms). Surprisingly, for such operations, particularly for offshore mooring, the installation of ropes and catenaries designed for them can be optimized; for example, ropes, catenaries, umbilical cables, or cables can be installed using less complex hardware or smaller and lighter installation equipment. Therefore, one embodiment of the invention relates to an article of manufacture, wherein the article is a one-dimensional article selected from the group consisting of ropes, slings, chains, catenaries, mooring ropes, umbilical cables, and cables. Preferably, the article is a rope or a parallel-wound catenary.

[0055] The UHMWPE filaments and yarns of the present invention are also well-suited for use as reinforcing elements (e.g., in linings) for reinforcing products such as hoses, pipes, pressurized containers, cables, and optical fibers, particularly when said reinforcing products are used in deep-water environments where reinforcement is required to support the load of the reinforcing product when it is in free suspension. Therefore, the present invention also relates to a lining and a reinforcing product comprising a reinforcing element or comprising said lining, wherein said reinforcing element or said lining comprises the UHMWPE filaments or yarns of the present invention.

[0056] Most preferably, the UHMWPE filaments or yarns of the present invention are used in applications where the filaments and yarns are subjected to static tension or dynamic tension or static and dynamic loads, particularly long-term and ultra-long-term tension or loads. Static tension and dynamic tension, as used herein, refer to the filaments or yarns in an application being under tension at all times or for most of the time, regardless of whether the tension is at a constant level (e.g., a heavy object freely suspended on a rope comprising the filaments or yarns) or at a varying level (e.g., if exposed to thermal expansion or water wave motion). Examples of applications encountering static and dynamic tension are, for example, many medical applications (e.g., cables and sutures) as well as mooring ropes and tension-enhancing elements, because the improved mechanical properties of the filaments and yarns of the present invention result in improved performance in these similar applications. A specific application of the UHMWPE filaments and yarns of the present invention is in crane ropes or catenaries, where the articles can reach elevated temperatures due to ambient temperature and / or internal heat generated by vibration, bending, or friction.

[0057] The present invention also relates to composite articles containing UHMWPE filaments or yarns of the present invention. In a preferred embodiment, the composite article comprises at least one monolayer containing UHMWPE filaments of the present invention. The term monolayer refers to a filament layer, i.e., filaments in one plane. In a further preferred embodiment, the monolayer is a unidirectional monolayer. The term unidirectional monolayer refers to a filament layer with unidirectional orientation, i.e., filaments oriented substantially parallel in one plane. In yet another preferred embodiment, the composite article is a multilayer composite article comprising multiple unidirectional monolayers, wherein the orientation of the filaments in each monolayer is preferably rotated by an angle relative to the orientation of the filaments in the adjacent monolayer. Preferably, the angle is at least 30°, more preferably at least 45°, even more preferably at least 75°, and most preferably about 90°. Multilayer composite articles have proven to be very useful in ballistic applications, such as bulletproof vests, helmets, hard and flexible protective plates, plates for vehicle armor, etc. Therefore, the present invention also relates to ballistic articles containing UHMWPE filaments of the present invention as listed above. Therefore, one embodiment of the present invention relates to two-dimensional articles, preferably selected from the group consisting of: interwoven fabrics, such as woven, braided or knitted fabrics; and non-interwoven fabrics, such as felt, unidirectional sheets or films.

[0058] The UHMWPE filaments and yarns of the present invention are also suitable for medical devices, such as sutures, medical cables, implants, surgical repair products, etc. Therefore, the present invention also relates to a medical device, particularly a surgical repair product, and more particularly to a suture and a medical cable comprising the UHMWPE filaments and yarns of the present invention.

[0059] It has also been observed that the UHMWPE filaments and yarns of the present invention are suitable for other applications, such as synthetic chains, conveyor belts, tension structures, concrete reinforcements, fishing lines and nets, ground nets, cargo nets and curtains, kite lines, dental floss, tennis racquet strings, canvas (e.g., tent canvas), nonwoven clothing and other types of fabrics, webbing, battery separators, capacitors, pressure vessels (e.g., pressure cylinders, inflators), hoses, (marine) umbilical cables, cables, optical fibers and signal cables, automotive equipment, power transmission belts, building structural materials, composite sports equipment (e.g., skis, helmets, kayaks, canoes, bicycles and boat hulls and masts), speaker cones, high-performance electrical insulators, radomes, sails, geotextiles (e.g., mats), bags and nets, etc. Therefore, the present invention also relates to the applications listed above that incorporate the UHMWPE filaments or yarns of the present invention.

[0060] The present invention also relates to an elongated object comprising a plurality of UHMWPE filaments of the present invention, wherein the filaments are at least partially fused together. In one embodiment, the elongated object is a monofilament. In a different embodiment, the elongated object is a tape. At least partially fused filaments are understood herein to mean that the individual filaments are fused at a plurality of locations along their length and are not connected between said locations. Preferably, the filaments are completely fused together, i.e., the individual filaments are fused together substantially over their entire length. Preferably, the fusion is performed by at least compressing the plurality of UHMWPE filaments at a temperature lower than the filament melting temperature. The melting temperature of the fiber can be determined by DSC using the method described as on page 13 of WO 2009 / 056286. Methods for fusing UHMWPE filaments into monofilaments and tapes are known in the art and disclosed, for example, in WO2006 / 040190, WO2009 / 056286 and WO2013 / 131996. It has been observed that by using the filaments of the present invention, monofilaments and tapes with optimized creep properties are obtained. Such products are suitable for applications such as: fishing lines; linings; reinforcing elements; ballistic products, such as armor; automotive parts; and construction applications, such as doors.

[0061] The invention is further explained through the following examples, but the invention is not limited thereto.

[0062] As mentioned in this application, " method "as follows: •UHMWPE Elongation stress ( Elongational stress ,ES) is measured according to ISO 11542-2A.

[0063] • Intrinsic viscosity (IV) was determined according to the method of ASTM D1601 (2004) in decahydronaphthalene at 135°C by extrapolating the viscosity measured at different concentrations to zero concentration, with a dissolution time of 16 hours by gentle stirring with shaking, wherein the amount of BHT (butylated hydroxytoluene) in the solution was 2 g / L as an antioxidant.

[0064] • yarn fineness It is determined by weighing 100 meters of yarn. The fineness of the yarn is calculated by dividing the measured weight by the length and converting it to the corresponding dtex unit in g / 10,000m.

[0065] • Filament linear density (fineness) and mechanical properties (filament toughness and filament tensile modulus) Measurements were performed on a semi-automatic microprocessor-controlled tensile testing machine (Favimat, machine number 37074, from Textechno Herbert Stein GmbH & Co. KG, Mönchengladbach, Germany). This machine operates based on the constant elongation rate principle (DIN 51221, DIN 53 816, ISO 5079) and features an integrated measuring head for measuring linear density using constant tensile force and gauge length, along with a variable excitation frequency (ASTM D 1577), based on vibration testing principles. The Favimat machine was equipped with a 1200 cN balance, serial number 14408989. The Favimat software version was 3.0.3625.

[0066] By according to Figure 3 Adjusting the Favimat clamps eliminated clamp slippage during filament tensile testing, preventing filament breakage.

[0067] The upper clamp 121 is attached to a force sensor (not shown). During the tensile test, the lower clamp 122 moves in the downward direction (D) at a selected tensile test speed. The filament (125) to be tested is clamped at each of the two clamps between two jaw faces 123 (4 mm × 4 mm × 2 mm) made of Plexiglass® and wound three times over ceramic pins 124 and 125. The linear density of the filament length between the ceramic pins is determined by inspection with a vibrating mirror prior to the tensile test. The filament linear density is determined at a 50 mm filament gauge length (F) (see [reference]). Figure 3The tensile test was conducted at a pretension of 6.0 cN / tex (using the expected filament linear density calculated from the yarn linear density and filament number). Tensile tests were then performed at a test speed of 25 mm / min with the lower clamp and a pretension of 0.50 cN / tex, and filament toughness was calculated from the measured breaking force and the filament linear density determined by vibratory mirror examination. Elongation strain was determined by using the entire filament length between the upper and lower plexiglass jaws at a defined pretension of 0.50 cN / tex. The stress-strain curve typically shows some relaxation at the beginning, therefore the tensile modulus was calculated as the chordal modulus between the two stress levels. The chordal modulus (Chord Modulus) from 10 to 15 cN / dtex is given by equation (1): 10 to 15 cN / dtex chordal modulus = (1) in: ε 10 = Elongation strain (%) under a stress of 10 cN / dtex; and ε 15 = Elongation strain (%) under a stress of 15 cN / dtex.

[0068] The measured elongation at break was relaxed and corrected using equation (2): (2) in: EAB = Corrected elongation at break [%) EAB (measured value) = Measured elongation at break [%] ε5 = Elongation strain at a stress of 5 cN / dtex [%] CM(5:10) = chordal modulus between 5 and 10 cN / dtex [N / tex].

[0069] • Board, sheet or single layer areal density ( Areal density The (AD) is determined by measuring the weight of a sample (preferably 0.4m × 0.4m) with an error of 0.1 g.

[0070] • Linear density ( Linear Density (LD). Unless otherwise specified herein, the linear density of an article is defined by its weight per unit length. The linear density can be measured, for example, by separating the article along a defined length (e.g., 1 m) and weighing it. Dividing the weight of the article by its length will provide its linear density.

[0071] • Molded products bulletproof performanceThe V50 values ​​were determined by calculating the values ​​of eight independent shots fired from eight separate plates. The square sample plates measured 200 mm × 200 mm, with the filaments oriented parallel to their sides. The sample plates were secured to the back of a target holder frame, one side parallel to the ground, and held in place by a small piece of tape. The firing distance was 10 meters, with the shot aimed perpendicularly at the center of the plate. The projectiles used were 7.62 × 39 mm MSC (AK47), supplied by Sellier and Bellott, Czech Republic. The first shot was fired at the projectile velocity (V50), at which 50% of the shots were expected to be blocked. If blocking occurred, the next shot was fired at the expected velocity 40 m / s higher than the previous velocity. If penetration occurred, the next shot was fired at the expected velocity 40 m / s lower than the previous velocity. The projectile velocity was measured 1 meter before impact. The V50 values ​​obtained from the experiment were the average of the four highest blocking values ​​and the four lowest penetration values. When there is a surplus in blocking or penetration, these surpluses need to be eliminated until the number of shots that caused the blocking is the same as the number of shots that caused the penetration. This is achieved by eliminating the blocking result with the lowest rate of fire or eliminating the penetration result with the highest rate of fire.

[0072] • Interval back deformation (interval BFD) Back Face Deformation The reading was measured using a 9 mm, 124-grain FMJ Remington threat shot at a velocity of 430 + / - 9 m / s, according to the captive method.

[0073] A 200 mm × 200 mm plate was placed in front of a 12 cm thick Roma clay. A 1 / 2-inch (12.7 mm) thick aluminum spacer frame was placed between the plate and the clay, such that the back of the plate was half an inch from the clay surface, simulating the actual positioning of a ballistic plate relative to a human body. The plate / spacer / clay assembly was held in place by using rubber bands along the edges of the components. A single shot was fired at the center of the plate, and the indentation of the clay was measured in mm. The average indentation depth of 8 samples was reported.

[0074] For cold-interval back deformation, the plates were tested at room temperature, while for hot-interval back deformation, the plates were conditioned in an oven at 71°C (160°F) for at least 4 hours.

[0075] • Tensile properties of multifilament yarnAccording to ASTM D885M, the elongation at break, toughness, tensile strength, and tensile modulus of multifilament yarns are defined and determined using fibers with a nominal gauge length of 500 mm, a crosshead speed of 50% / min, and an Instron 2714 clamp of model "Fibre Grip D5618C". The modulus is determined based on the slope between 0.3% and 1% strain from the measured stress-strain curve. To calculate the modulus and strength, the measured tensile force is divided by the fineness. The tensile properties of UHMWPE yarns can be obtained using high-oriented polyethylene with a specific gravity of 970 kg / m³. 3 Let's convert it.

[0076] • Creep properties of yarn It was determined according to the method described in the following article: “Predicting the CreepLifetime of HMPE Mooring Rope Applications” by MP Vlasblom and RLMBosman – Proceedings of the MTS / IEEE OCEANS 2006 Boston Conference and Exhibition, held in Boston, Massachusetts on September 15-21, 2006, Session Ropes and tension Members (Wed 1:15 PM – 3:00 PM). More specifically, it can be determined using... Figure 1The schematically illustrated apparatus is used to determine the creep rate (CR) and creep life (CLT) of an unwound yarn sample approximately 1500 mm long, i.e., a yarn with multiple substantially parallel filaments. The yarn sample is clamped between clamps (101) and (102) in a non-slip manner by winding each end of the yarn around the axis of the clamp several times, and then tying the free end of the yarn to itself. The final length (200) of the yarn between the clamps is approximately 180 mm. The clamped yarn sample is placed in a controlled chamber (500) at a temperature of 70°C by connecting one clamp to the ceiling of the chamber (501) and attaching a specific counterweight (300) to the other clamp, thereby applying a predetermined load (400 or 775 MPa, as reported in the examples). The load is achieved by adjusting the weight of the attached counterweight (300) while taking into account the fineness of the yarn. The positions of clamps (101) and (102) can be read on a scale (600) using indicators (1011) and (1021). The initial position of the counterweight is such that the length (200) of the yarn is equal to the distance between (101) and (102) measured on (600). The elongation of the yarn over time is tracked by reading the position of the indicator (1021) on the scale (600). The time required for the indicator to advance 1 mm for every 1 mm of elongation is recorded until the yarn breaks.

[0077] Yarn at a certain time t elongation ε i [in mm] is understood in this article as: at a certain moment t The length of the yarn between each clamp is L ( t ) and the initial length of the yarn between each clamp (200) L 0 The difference between them. Therefore: The elongation of the yarn [in percentage] is: Creep rate [in seconds] -1 [Calculation] is defined as: the change in yarn length per time step, which is determined according to equation (1): (1) in ε i and ε i-1 At any moment i and the previous moment i Elongation at -1 [in %]; t i andt i-1 The elongation of the yarns are respectively ε i and ε i-1 The required time (in seconds). Then, as follows: Figure 2 As shown by the irrelevant yarns in the figure, the creep rate versus elongation (in percentage) on a logarithmic scale is plotted to produce a curve (100). Then, measurements are taken... Figure 2 The minimum value (1) of the curve is used, and the linear portion (2) following the minimum value (1) is fitted with a straight line (3), which also contains the minimum value (1) of the curve. The elongation (4) at which the curve (100) begins to deviate from the straight line is used to determine the time when a single filament experiences initial breakage (also referred to as the start of state-3). This time is considered the failure life of the yarn under study. The elongation (4) is considered the elongation during the creep life, i.e., the elongation until the failure time.

[0078] The minimum value in the figure is also referred to as the minimum creep rate, and in the context of this invention, it is used interchangeably with the creep rate CR, wherein temperature and load are reported as indicators of CR. 70,400 .

[0079] • Creep properties of filaments The creep test was performed by subjecting individual filaments to permanent loads (400 MPa, 775 MPa, 1200 MPa) at a constant temperature while recording elongation over time, similar to the yarn method described above. The filament creep test was conducted on an RSA-G2 solids analyzer (tester number 4020-0014, from Waters / TA Instruments, New Castle, England). The RS-G2 solids analyzer was equipped with a 35 N balance and controlled via the TA Instruments TRIOS software. The clamping settings on the RSA-G2 solids analyzer were similar to... Figure 3 The Favimat setup is shown and described above. The upper clamp 121 is attached to a force sensor (not shown) and moves in an upward direction until the selected creep load is reached. The filament (125) to be tested is clamped between the two jaw faces at each of the two clamps and wound three times over the ceramic pins 124 and 125.

[0080] To determine the permanent load to be applied during creep measurements, the linear density of the corresponding filament was measured on a semi-automatic microprocessor-controlled tensile testing machine (Favimat, testing machine number 37074, from TextechnoHerbert Stein GmbH & Co. KG, Mönchengladbach, Germany) according to the Favimat method described above. The difference was that the filament linear density was measured at a pretension of 10 cN / tex over a 100 mm filament gauge length (F) (using the expected filament linear density calculated from the yarn linear density and the number of filaments). Since vibration inspection measurements are non-destructive, a 100 mm filament sample was used to determine the creep properties of the filament.

[0081] Similar to the yarn measurements, state-1 and state-2 creep were observed, corresponding to the reversible elongation and actual creep of the filament. The minimum value in state-2 was reported as the minimum creep rate, or simply the creep rate. State-3 was not observed for individual filaments because the breakage of a single filament represents the end of the measurement.

[0082] Side chains per 1000 total carbon atoms It was determined by NMR technology. The amount of methyl groups present in UHMWPE (e.g., as methyl side groups and as methyl terminal groups (in the methyl terminal groups of ethyl or butyl short side chains and long chain branches and the methyl terminal groups of polyethylene chains)) is the same as the amount of methyl groups per thousand carbon atoms contained in UHMWPE, as determined by the following proton... 1 Measured by H liquid-NMR (hereinafter referred to as "NMR"): Add 3–5 mg of UHMWPE to 800 mg of a solution of 1,1',2,2'-tetrachloroethane-d2 (TCE), wherein each gram of TCE contains 0.04 mg of 2,6-di-tert-butyl-paracresol (DBPC). The purity of TCE is > 99.5%, and the purity of DBPC is > 99%.

[0083] Place the UHMWPE solution in a 5 mm standard NMR tube and heat it in an oven at 140-150°C while stirring until the UHMWPE dissolves.

[0084] - A high-field (≥ 400 MHz) NMR spectrometer was used with a 5 mm reverse probe and the following settings were employed to record NMR spectra at 130 °C: the sample spin rate was between 10⁻¹⁵ Hz, and nuclei were observed. 1 H, locking the nucleus – 2H, pulse angle is 9 The relaxation delay was 30 seconds, the number of scans was set to 1000, the scan width was 20 ppm, the digital resolution of the NMR spectrum was less than 0.5, the total number of points in the obtained spectrum was 64 k, and the spectral line broadening was 0.3 Hz.

[0085] - The spectrum of recorded signal intensity (arbitrary units) vs. chemical shift (ppm) was corrected by fixing the peak corresponding to TCE at 5.91 ppm, and is hereby referred to as the spectrum. Figure 1 .

[0086] After correction, two peaks of nearly equal intensity (doublets) can be identified in the range of 0.8 to 0.9 ppm to determine the content of methyl side groups. The first peak should be located at approximately 0.85 ppm, and the second peak should be located at approximately 0.86 ppm.

[0087] The three peaks (triplet) that determine the amount of methyl end groups are also present in the 0.8 to 0.9 ppm range and may be located after the second peak of the methyl side group, toward the increasing ppm range.

[0088] - Use standard ACD software produced by ACD / Labs to deconvolve each peak.

[0089] - The area A1 of the deconvolution peak used to determine the methyl side group content was calculated using the same software. 甲基侧基 That is, A1 = A1 第一波峰 +A1 第二波峰 A1 甲基侧基 It will be referred to as A1 in the following text.

[0090] -- The area A2 of the deconvolution peak used to determine the methyl terminal group content was calculated using the same software. 甲基端基 That is, A2 = A2 第一波峰 +A2 第二波峰 +A2 第三波峰 A2 甲基端基 It will be referred to as A2 in the following text.

[0091] - In addition, area A3 was identified corresponding to the area of ​​the peak given by the CH2 group of the UHMWPE backbone, which is the highest peak in the entire spectrum, located in the ppm range between 1.2 and 1.4.

[0092] - The number of methyl side groups per 1000 carbon atoms is calculated as follows: methyl / 1000C = ; Since this represents the total amount of methyl groups present in UHMWPE, the amount of side chains is determined by subtracting the terminal methyl groups of the polymer chains from the total amount of methyl groups. Dividing the number-average molecular weight (Mn) of UHMWPE by 14 g / mol yields the total average carbon atom mass per polymer chain. Each chain has two terminal methyl groups; therefore, the number of terminal methyl groups to be subtracted per 1000 C atoms can be calculated using the following formula: Terminal methyl groups / 1000 C = .

[0093] Therefore, the side chains for every 1000 total carbon atoms are obtained by subtracting the terminal methyl groups from the total methyl groups in UHMWPE.

[0094] experiment Commercial-scale yarn grades have been used to design tension components for floating offshore wind power platforms. Mechanical and physical properties are reported in Tables 1, 2, and 3 below. In this document, yarn A is an ultra-low creep yarn with 780 filaments and a yarn fineness of 1760 dtex, comprising UHMWPE with an IV of approximately 16 dl / g and approximately 0.5 short chain branches / 1000TC, manufactured according to a technique similar to that described in WO2012 / 139934; yarn B is a low creep yarn with 780 filaments and a yarn fineness of 1760 dtex, comprising UHMWPE with an IV of approximately 17 dl / g and approximately 0.3 short chain branches / 1000TC, and manufactured according to a technique similar to that described in WO 2009 / 043597; yarn C is a high-tenacity yarn with 780 filaments and a yarn fineness of 880 dtex, comprising linear UHMWPE with an IV of approximately 22 dl / g, manufactured according to a technique as described in WO2005066401.

[0095] For yarn 1, an ES of 0.92 N / mm was prepared. 2 A 4 wt% slurry of UHMWPE homopolymer powder in decahydronaphthalene was prepared. UHMWPE had no detectable amount of short-chain or long-chain branches. The slurry was fed into a 133 mm co-rotating twin-screw extruder and heated therein, where it was converted into a homogeneous solution at 187°C. After passing through the extruder, the solution temperature was reduced to 180°C and conveyed by a gear pump at a rate of 2.4 g / min / hole through a spinneret with 780 spinning orifices.

[0096] The spinning orifice has an initial cylindrical channel with a diameter of 3 mm, which then tapers at a 30° angle to a cylindrical channel with a diameter of 1.0 mm and a length of 10 mm. The fluid filament extending from the cylindrical channel enters an air gap of 15 mm in length. The fluid filament is wound at such a rate that a 7-fold drawdown is applied to the fluid filament in the air gap, and then cooled to room temperature in a water bath.

[0097] The filaments were then placed in an oven. In the oven, the filaments were further stretched eight times at approximately 147°C, and decahydronaphthalene was evaporated. In a second step, the yarn was stretched at 152°C with a stretch ratio of 4. Yarns with an IV of 33 dl / g and mechanical and physical properties as reported in Tables 1, 2, and 3 were obtained.

[0098] Table 1 Table 2 Table 3 Comparative experiments 1.1, 1.2, and 1.3, and Example 1 The design of the catenary of a floating offshore wind turbine depends on a wide range of factors. When designing a tension leg platform, the dynamic stiffness (EA) of the catenary is a critical design parameter as it defines the platform's dynamic stability and aims to prevent resonance under normal excitation. In addition to the dynamic stiffness requirement, the catenary should also be able to withstand both permanent and peak stresses over its required lifespan. Last but not least, the catenary will be preloaded with an average load by the buoyancy of the platform's floats, while dynamic loads caused by weather and tides will add time-varying loads around that average.

[0099] The exact details regarding the size of the preload, dynamic stiffness, and lifespan requirements will vary depending on the device design and are further influenced by the design of the catenary (e.g., braiding structure and angle). Nevertheless, for typical water depths (100 to 500 meters), the preload due to buoyancy is typically on the order of 10,000 kN per leg. To avoid resonant excitation, the stiffness of each leg is set at 5,000 MN, and to ensure the same dynamic response, the dynamic stiffness should increase proportionally with increasing water depth.

[0100] As a working example, the catenary for a 100-meter water depth may require a dynamic stiffness of 5000 MN and a tensile preload of 10000 kN, and must be maintained for 25 years. This necessitates a safety factor of 3, resulting in a design life of 75 years at an average ambient temperature of 20°C. When the platform is installed at water depths of 50 meters, 200 meters, or 300 meters, the preload remains constant, but the required dynamic stiffness varies proportionally to 2500 MN, 10000 MN, and 15000 MN, respectively.

[0101] The required linear weight of the catenary to meet the standards for dynamic stiffness, peak load, and life mentioned above is reported below.

[0102] Table 4 When comparing the required linear weights of comparative experiments 1.1, 1.2, and 1.3, representing catenary designs with yarns A, B, and C respectively, in Table 4, it can be seen that low-creep yarn A outperforms the other yarns at limited water depths, but fails to meet the requirements when a given dynamic stiffness is needed at higher lengths (e.g., depths). In contrast, the yarns and filaments according to the present invention (i.e., having a modulus of 1845 cN / dtex and 1×10⁻⁶ filaments)... -7 s -1 Yarns with the lowest creep rate have proven to be the preferred material for providing load-bearing cables with low linear density (i.e., mass per meter of filament) and are superior to other known synthetic fibers.

[0103] This indicates that the yarn 1 according to the present invention significantly improves the dynamic response of the UHMWPE yarn tension member without significantly impairing fatigue performance.

[0104] It has also been found that the yarns and filaments of the present invention can be used to manufacture other fiber products, such as ballistic sheets. Equally surprising is that this new and unique mechanical property provides advantages in these applications, such as backface deformation. Backface deformation is actually the size of the impact dent that can be measured on the non-impact side of a ballistic component. It is typically measured in mm as the maximum deformation perpendicular to the plane of the impacted surface of the ballistic article. Surprisingly, it has been observed that the size of the impact dent is small when molded articles are produced using the filaments according to the present invention. In other words, the backface deformation is small. This armor would be particularly suitable for use in combat helmet shells because they exhibit a reduced backface signature in terms of projectile resistance, thereby reducing trauma to the skull and brain after being struck by a blocked projectile.

[0105] Comparative Experiment 2.1 A composite monolayer of polyethylene filaments was prepared according to the method described in WO2005066401. The aforementioned multifilament yarn C, having 780 filaments, a yarn fineness of 880 dtex, and a modulus of 1590 cN / dtex, was used to manufacture a unidirectional (UD) monolayer by feeding the yarn from multiple spools from a yarn rack, spreading the filaments, and impregnating the filaments with an aqueous dispersion of Kraton® D1107 styrene-isoprene-styrene block copolymer as a binder material. After drying, the areal density of the UD monolayer was 34 g / m³. 2 The adhesive content is approximately 17 wt%.

[0106] Four such unidirectional layers were cross-laminated in a 0°90°0°90° sequence and cured for 30 seconds at a pressure of 30 bar and a temperature of 115°C. The resulting sheet had an areal density of 136 g / m². 2 .

[0107] Example 2 Repeat CE 2.1, except that yarn C is replaced by yarn 1 as described above (i.e., a multifilament yarn with 780 filaments, a yarn fineness of 810 dtex, and a modulus of 1845 cN / dtex). The slightly lower yarn dtex results in an areal density of 30 g / m² with a binder content of approximately 15 wt%. 2 The UD single layer, and the resulting sheet has an areal density of 120 g / m². 2 .

[0108] Multiple sheets of CE 2.1 and Ex 2 are stacked to form a target sheet density of 6.8 kg / m². 2 and 9.8 kg / m 2 The components were assembled. In total, 50 and 72 sheets of CE 2.1 and 57 and 82 sheets of Ex 2 were stacked, respectively, with the filaments in adjacent monolayers maintaining alternating 0° / 90° orientations throughout the stack. The sheet assemblies were pressed at 138°C and 16.5 MPa for 40 minutes, then cooled at 2 MPa for 20 minutes, and finally cut into 200 mm × 200 mm plates for ballistic testing. The molded plates are reported as CE 2.1 and Ex 2 in Table 3. The areal density is 9.8 kg / m³. 2 The molded plate was fired with 7.62 x 39 mm MSC (AK47) bullets to determine its V50. As described in the "Methods" section, the AD was 6.8 kg / m when fired with 9 mm FMJ Remington bullets. 2 The molded plate is used to determine the cold-interval back deformation and the hot-interval back deformation.

[0109] Table 5 As can be seen, when compared at the same areal density, the hard ballistic assembly containing the yarn of the present invention exhibits unexpected improvements in its cold and hot back deformation performance.

Claims

1. A multifilament ultra-high molecular weight polyethylene (UHMWPE) yarn having at least 25 filaments, a fineness of at least 50 dtex, a filament fineness of at least 0.50 dtex, a tensile modulus of at least 1500 cN / dtex, and a maximum tensile modulus of 5.0 × 10⁻⁶ cN / dtex measured at 70°C under a load of 400 MPa. -7 s -1 The minimum creep rate, wherein the ultra-high molecular weight polyethylene is a linear homopolymer of ethylene.

2. The multifilament yarn according to claim 1, wherein the yarn has a toughness of at least 42.0 cN / dtex.

3. The multifilament yarn according to claim 1 or 2, wherein the yarn has a maximum density of 2.5 × 10⁻⁶. -7 s -1 Minimum creep rate CR 70 / 400 .

4. The multifilament yarn according to any one of claims 1 to 3, wherein the multifilament yarn comprises at least 50 filaments.

5. A filament suitable for use in a multifilament yarn according to any one of claims 1 to 4, wherein the filament has a fineness of at least 0.50 dtex, a modulus of at least 1700 cN / dtex, and a modulus of at most 1.0 × 10⁻⁶. -7 s -1 The creep rate (measured at 70°C and 400 MPa load, CR) 70 / 400 ), wherein the modulus and CR of the filament 70 / 400 The measurements were performed according to the corresponding methods described in the "Methods" section.

6. A filament suitable for use in a multifilament yarn according to any one of claims 1 to 4, wherein the filament has a fineness of at least 0.50 dtex, a modulus of at least 1700 cN / dtex, and a modulus of at most 1.0 × 10⁻⁶. -5 s -1 The creep rate (measured at 70°C and 1200 MPa load, CR) 70 / 1200 ), wherein the modulus and CR of the filament 70 / 1200 The measurements were performed according to the corresponding methods described in the "Methods" section.

7. The filament according to claim 5 or 6, wherein the filament has a modulus of at least 1800 cN / dtex.

8. The multifilament yarn or filament according to any one of claims 1 to 7, wherein the multifilament yarn or filament comprises UHMWPE with an intrinsic viscosity of at least 10 dL / g.

9. The multifilament yarn or filament according to claim 8, wherein the UHMWPE of the yarn or filament has an IV of 12 dL / g to 40 dL / g.

10. The multifilament yarn or filament according to any one of claims 1 to 9, wherein the UHMWPE of the yarn or filament comprises at most 0.10 side chain branches per thousand total carbon atoms.

11. The multifilament yarn or filament according to any one of claims 1 to 10, wherein the filament or the filament of the yarn has a fineness of at least 0.80 dtex.

12. An article comprising a multifilament yarn according to any one of claims 1 to 4 or claims 8 to 11, or a filament according to any one of claims 5 to 11.

13. The article of claim 12, wherein the article is a one-dimensional article selected from the group consisting of ropes, slings, chains, catenary ropes, tie ropes, umbilical cables and cables.

14. The article of claim 13, wherein the article is a two-dimensional article selected from the group consisting of: interwoven fabrics, such as woven fabrics, braided fabrics or knitted fabrics; and non-interwoven fabrics, such as felt, unidirectional sheet or film.

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