Polymer-filled polyolefin fibers

Abstract

The present invention relates to a polyolefin fiber comprising a polymeric structure, the polymeric structure comprising a condensation polymer and a functionalized polymer, respectively, the polyolefin fiber being a gel-spun high performance polyethylene fiber having a yarn tenacity of at least 1 N / tex, the polymeric structure being immiscible with and dispersed in the polyethylene fiber. The gel-spun high performance polyethylene fibers are gel-spun ultra-high molecular weight polyethylene fibers. The present invention further relates to a process for producing polyolefin fibers, comprising the steps of melt-mixing a condensation polymer or a condensation polymer containing at least one additive, a functionalized polymer, and optionally a thermoplastic polymer and / or at least one additive to form a polymeric structure; mixing a polyolefin powder, the polymeric structure, and a solvent to form a mixture; and spinning and drawing the mixture obtained in step ii) to form a polyolefin fiber comprising the polymeric structure.

Description

Detailed Description of the Invention

[0001] The present invention relates to polyolefin fibers comprising polymeric structures. The present invention also relates to a process for producing polyolefin fibers comprising polymeric structures. Furthermore, the present invention relates to articles comprising polyolefin fibers.

[0002] Polyolefin fibers containing polymeric structures are generally known in the art. For example, EP 1869129 B1 discloses polyolefin fibers containing a polyolefin, preferably polypropylene, a maleic anhydride-based polyolefin compatibilizer, and optionally a dye promoter that is a terephthalate-based copolyester. U.S. Patent Application Publication No. 2015 / 0361615 A1 discloses polyolefin fibers formed by blending an olefin, preferably polypropylene, with a masterbatch consisting of amorphous nylon, a maleic anhydride-modified olefin, and nylon 6 or 6,6, and dyeing the blended olefin using a nylon dyeing system.

[0003] However, it is known that the mechanical properties of polyolefin fibers, as known in the art, rapidly deteriorate due to the introduction of defects, such as different (polymer) structures, into the composition of the polyolefin fiber. In addition, it is well known that gel-spun high-performance polyolefin fibers, specifically high-performance polyethylene (HPPE) fibers, are difficult to functionalize due to the inherent non-polarity of polyolefins, such as polyethylene. Furthermore, in the case of melt-spun high-performance polyolefin fibers, such as HPPE fibers, the inventors have realized that when additives, such as polycondensation polymer particles, such as polyester particles, are added to the fiber, it is desirable for the particles to melt and partially blend with the high-performance polyolefin fiber to enable dispersion of the particles. Furthermore, the yarn tenacity of melt-spun or melt-extruded high-performance polyolefin fibers, such as HPPE fibers, as known in the art, is less than 1 N / tex.

[0004] Therefore, an object of the present invention is to provide a polyolefin fiber that maintains a very high level of mechanical properties, such as yarn tenacity and / or modulus, particularly yarn tenacity, when a polymeric structure is introduced into a fiber composition, and even when a large amount of the polymeric structure is introduced into the fiber composition, while also being highly versatile for use in a variety of applications, for example, for producing textiles having good dyeability and color fastness.

[0005] This object has been achieved by providing a polyolefin fiber comprising a polymeric structure, the polymeric structure individually comprising a condensation polymer and a functionalized polymer, the polyolefin fiber being a gel-spun high performance polyethylene fiber comprising the polymeric structure and having a yarn tenacity of at least 1 N / tex, whereby the polymeric structure is immiscible with and dispersed in the polyethylene fiber.

[0006] It has been surprisingly found that gel-spun high-performance polyethylene fibers according to the present invention, i.e., polyethylene fibers comprising polymeric structures (individually, i.e., each polymeric structure comprises a condensation polymer and a functionalized polymer) favorably dispersed throughout the fiber, retain high mechanical properties, particularly high yarn tenacity, even when the concentration of polymeric structures in the polyolefin (HPPE) fiber is high. Furthermore, it has been found that the polyolefin (HPPE) fibers according to the present invention can be easily functionalized, allowing the fibers according to the present invention to be used in a variety of applications. Furthermore, fabrics containing the polyolefin fibers according to the present invention have good colorability and colorfastness.

[0007] Within the context of the present invention, a "fiber" is understood to be an elongated body having a length dimension significantly greater than its transverse dimensions, such as width and thickness. The term "fiber" includes filaments, threads, ribbons, strips, or tapes, and the fibers can have a regular or irregular cross section. Preferably, the fibers are threads, more preferably multifilament threads. Tapes for the purposes of the present invention can have a cross-sectional aspect ratio of at least 5:1, more preferably at least 20:1, even more preferably at least 100:1, and even more preferably at least 1000:1. The width of the tape can be from 1 mm to 200 mm, preferably from 1.5 mm to 50 mm, and more preferably from 2 mm to 20 mm. The thickness of flat tapes is preferably from 10 μm to 200 μm, and more preferably from 15 μm to 100 μm.

[0008] High performance polyethylene (HPPE) fibers preferably have a yarn tenacity (which may also be referred to herein as tensile strength) of at least 1.5 N / tex, preferably at least 2 N / tex, more preferably at least 2.5 N / tex, and more preferably at least 3.5 N / tex, or at least 4 N / tex, measured according to the method described in the Examples section of the present invention. HPPE fibers preferably have a tensile modulus of at least 30 N / tex, more preferably at least 50 N / tex, even more preferably at least 80 N / tex or even at least 90 N / tex, and most preferably at least 100 N / tex. In the context of the present invention, tensile strength or yarn tenacity and tensile modulus are defined and measured on multifilament yarns as specified in ASTM D885M (using a nominal fiber gauge length of 500 mm, a crosshead speed of 50% / min, and an Instron 2714 clamp, type "Fibre Grip D5618C"; modulus measured as the slope between 0.3 and 1% strain).

[0009] A preferred high performance polyethylene is high molecular weight polyethylene (HMWPE) or ultra-high molecular weight polyethylene (UHMWPE), or a combination thereof.

[0010] For practical reasons, the fineness of the HPPE fibres, which may be multifilament yarns, may be at least 100 dtex and at most 50,000 dtex, preferably at most 20,000 dtex, more preferably at most 10,000 dtex, and most preferably at most 5,000 dtex. The fineness of the HPPE fibres, preferably of the HPPE yarns, is preferably in the range of 100-10,000 dtex, more preferably 500-7,000 dtex, even more preferably 1,000-6,000 dtex, and most preferably in the range of 500-4,000 dtex, and even most preferably in the range of 800-3,500 dtex. The fineness was determined according to the method described in the Examples section of the present invention.

[0011] In the context of the present invention, the expression "consisting essentially of" has the meaning that it may contain small amounts of further species, whereby small amounts are up to 5% by weight, preferably up to 2% by weight, of said further species, i.e. more than 95% by weight, preferably more than 98% by weight, of HPPE, e.g. HMWPE and / or UHMWPE.

[0012] In the context of the present invention, polyethylene (PE) may be linear or branched, whereby linear polyethylene is preferred. Linear polyethylene is understood herein to mean polyethylene having less than one side chain per 100 carbon atoms, preferably less than one side chain per 300 carbon atoms, with the side or branched chain generally containing at least 10 carbon atoms. The side chains can be suitably measured by FTIR. Linear polyethylene may further comprise up to 5 mol % of one or more alkenes copolymerizable therewith, such as propene, 1-butene, 1-pentene, 4-methylpentene, 1-hexene, and / or 1-octene.

[0013] The PE is preferably of high molecular weight, having an intrinsic viscosity (IV) of at least 2 dl / g, more preferably at least 4 dl / g, and most preferably at least 8 dl / g. Such polyethylenes with an IV greater than 4 dl / g are also referred to as ultra-high molecular weight polyethylene (UHMWPE). Intrinsic viscosity is an indicator of molecular weight that is more easily determined than actual molar mass parameters such as number average molecular weight and weight average molecular weight (Mn and Mw).

[0014] Polymeric structures in the context of the present invention are understood to be structures or droplets that are preferably dispersed in the HPPE fibers and are (substantially) immiscible with the high performance polyethylene (HPPE) fibers, i.e., form a heterogeneous mixture. Polymeric structures may be found within the high performance polyethylene fibers, but may also appear on their surface. Suitable polymeric structures and manufacturing processes are described, for example, in U.S. Patent Application Publication No. 2005 / 0222328, which is incorporated herein by reference.

[0015] The amount of polymeric structure in the HPPE fibers is preferably at least 0.001 wt%, more preferably at least 1 wt%, even more preferably at least 3 wt%, and most preferably at least 5 wt%, based on the total weight of the HPPE fibers. The amount of polymeric structure in the HPPE fibers is preferably at most 20 wt%, preferably at most 15 wt%, more preferably at most 12 wt%, and most preferably at most 10 wt%, based on the total weight of the HPPE fibers. A high amount of polymeric structure may adversely affect the mechanical properties of the HPPE fibers.

[0016] The polymeric structures or droplets are preferably dispersed in the polyolefin fibers. The polymeric structures can have any shape, for example, they can be in the form of particles or fibers (needles), sometimes referred to herein as dispersed particles or dispersed fibers. When the polymeric structures are spherical, the L / D ratio is preferably about 1, and the particles preferably melt at a temperature above the processing temperature of the fiber during fiber production, e.g., drawing. When the polymeric structures are needle-shaped, the L / D ratio is preferably greater than 1, and the particles preferably melt at a temperature below the processing temperature of the fiber during fiber production, e.g., drawing.

[0017] In the present invention, for particles in which no dimension is substantially greater than any other dimension of the particle, such as spherical or cubic particles, the average particle size is approximately equal to the diameter (D) of the average particle, i.e., diameter. In the context of the present invention, average means numerical average unless otherwise specified. For particles of elongated or non-spherical or anisotropic approximately oblong shape, such as needles, fibrils, or fibers, particle size may refer to the average length dimension (L) along the major axis of the particle, and the average particle diameter, or diameter for short, as sometimes referred to herein, refers to the average diameter of a cross section perpendicular to the length direction of said oblong shape. In cases where the particle cross section is not circular, the average diameter (D) is calculated using the following formula: D=1.15*A 1 / 2 where A is the cross-sectional area of ​​the particle. The aspect ratio (L / D) of a polymeric structure is the ratio of the length or average length (L) of the polymeric structure to the diameter or average diameter (D). The average diameter and aspect ratio of a polymeric structure may be determined using any method known in the art, such as the SEM method described in the Examples section herein.

[0018] The selection of the appropriate particle size, diameter and / or length will typically depend on the processing method and the filament fineness of the fiber. Nevertheless, it is desirable that the particles be small enough to pass through the spinneret orifice. The particle size and diameter may be selected small enough to avoid significant degradation of the tensile properties of the filled HPPE fiber. The particle size and diameter may have a log-normal distribution.

[0019] The particle size of the polymeric structure may vary depending on the application of the HPPE fibers, and is preferably less than one-third of the average diameter of the HPPE fibers.

[0020] The condensation polymer in the HPPE fibers according to the invention may be any polycondensation polymer known in the art. Polycondensation polymers are usually obtained in a polycondensation reaction, which is accompanied by cleavage of low molecular weight reaction products. Condensation polymers are known, for example, from patent documents such as EP 1 492 843, US 5 576 366, US 2005 / 0239927 A1, US 2015 / 0361615 A1, and EP 1 869 129 B1. Examples of suitable polycondensation polymers are thermoplastic condensation polymers, which may be crystalline or amorphous. The polycondensation polymer may be selected, for example, from the group consisting of polyamides, polyesters, polyurethanes, such as polycarbonates or polylactides, and / or copolymers thereof. Polycondensation reactions to obtain polycondensation polymers are known in the art and occur either directly between monomers or via intermediate product stages that are subsequently transformed by transesterification, which in turn involves cleavage of low molecular weight reaction products, or by ring-opening polymerization. Condensation polymers can be linear or branched.

[0021] Polyamides are typically polymers obtained by polycondensation of their monomers, either diamine and dicarboxylic acid components, or amino acids and difunctional monomers with carboxylic acid end groups, as known in the art. The reaction can occur, for example, by ring-opening polymerization using lactams. Suitable examples include any semicrystalline polyamide or blends thereof, as well as copolyamides. "Semicrystalline polyamide" is understood herein to encompass polyamides having crystalline and amorphous regions. Suitable polyamides include aliphatic polyamides such as PA6, PA66, PA46, PA410, PA610, PA11, PA12, PA412, and blends thereof, as well as semiaromatic polyamides. Suitable semiaromatic polyamides also include terephthalic acid-based polyamides such as PA6T, PA9T, PA4T, PA6T6I, PA10T, PAMXD6, and PAMXDT, as well as copolyamides thereof, blends thereof, and blends of aliphatic and semiaromatic polyamides.

[0022] Polyesters are known in the art as polymers obtained by polycondensation of their monomers, usually diol and dicarboxylic acid components. Various predominantly linear or cyclic diol components can be used in the HPPE fibers according to the invention. Various predominantly aromatic dicarboxylic acid components can also be used. The dicarboxylic acids can also be replaced by their corresponding dimethyl esters. Suitable examples of polyesters include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), which can be used either as homopolymers or as copolymers.

[0023] The amount of condensation polymer may be at least 0.1% and at most 50% by weight, based on the total composition of the HPPE fibres according to the invention, preferably 0.1 to 30% by weight, more preferably 0.1 to 20% by weight, more preferably 0.1 to 10% by weight, even more preferably 0.1 to 5% by weight, and most preferably 0.1 to 3% by weight, based on the total composition of the HPPE fibres according to the invention.

[0024] A functionalized polymer is herein understood to be a polymer having a functional group, preferably a terminal functional group capable of reacting with other functional groups. Examples of suitable functional groups include carboxylic acid groups, anhydride groups, ester groups, salt groups, ether groups, epoxy groups, amine groups, alkoxysilane groups, alcohol groups, or oxazoline groups. Suitable functional polymers are disclosed in patent literature, such as EP 1492843, U.S. Pat. No. 5,576,366, U.S. Pat. Appl. Publication No. 2005 / 0239927A1, U.S. Pat. Appl. Publication No. 2015 / 0361615A1, and EP 1869129B. Preferably, the functional group is selected from maleic anhydride (MAH) groups and epoxy groups.

[0025] Suitable polymers capable of providing functional groups include, for example, ethylene homopolymers and copolymers of ethylene with one or more alpha-olefin comonomers having 3 to 10 carbon atoms, specifically propylene, isobutene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene, which can be prepared by any method known in the art using known catalysts, such as Ziegler-Natta, Philips, and single-site catalysts. The amount of comonomer in the ethylene copolymer can be 0 to 50% by weight, and preferably 5 to 35% by weight. Such polyethylenes are known in the art as high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), linear very low-density polyethylene (VL(L)DPE), and plastomers.

[0026] The functional groups may be intrinsic to the polymer, such as a copolymer, or may be present via graft polymerization. Suitable polymers with intrinsic functional groups include, for example, ethylene vinyl acetate (EVA), ethylene methyl acrylate (EMA), ethylene butyl acrylate (EBA), polyvinyl acetate (PVA), polyglycidyl methacrylate (PGMA), styrene maleic anhydride (SMA), and ionomers.

[0027] Preferably, the functional group is present in the polymer, for example, by grafting an ethylenically unsaturated functionalized compound onto the polymer. Suitable ethylenically unsaturated functionalized compounds are compounds that can be grafted onto at least one of the aforementioned suitable polyolefins. The ethylenically unsaturated functionalized compound contains one carbon-carbon double bond, which can be grafted to form branched side chains on the polymer. Examples of suitable ethylenically unsaturated functionalized compounds are unsaturated carboxylic acids and their esters, anhydrides, and metal and non-metal salts. The ethylenically unsaturated bond in the compound is preferably conjugated with a carbonyl group. Examples include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylcrotonic acid, and cinnamic acid, as well as their esters, anhydrides, and possible salts. Among compounds having at least one carbonyl group, maleic anhydride is preferred. Examples of suitable ethylenically unsaturated functionalized compounds having at least one epoxy ring include, for example, glycidyl esters of unsaturated carboxylic acids, glycidyl ethers of unsaturated alcohols and alkylphenols, and vinyl esters and allyl esters of epoxycarboxylic acids.Glycidyl methacrylate is particularly suitable.Examples of suitable ethylenically unsaturated functionalized compounds having at least one amine functionality include, for example, allylamine, propenyl, butenyl, pentenyl, and hexenylamine, amine ethers, such as isopropenylphenylethylamine ether.

[0028] The amine group and unsaturated bond are usually positioned relative to one another so as not to affect the grafting reaction to an undesirable extent. The amine may be unsubstituted or substituted, for example, with alkyl, aryl, halogen, ether, and thioether groups.

[0029] Examples of suitable ethylenically unsaturated functionalized compounds having at least one alcohol functionality are all ethylenically unsaturated compounds having etherified or esterified hydroxyl groups or hydroxyl groups that are neither etherified nor esterified, for example, allyl and vinyl ethers of alcohols such as ethyl alcohol and highly branched and unbranched alkyl alcohols, as well as alcohol-substituted acids, preferably allyl and vinyl esters of carboxylic acids with C3-C8 alkenyl alcohols.

[0030] The functionalized polymer may be selected from the group of grafted (co)polyolefins (e.g., (co)polyethylene) and poly(glycidyl methacrylate). More preferred functionalized polymers are polyolefins, preferably grafted polyethylene. Preferably, the polyethylene is grafted with an ethylenically unsaturated functionalizing compound.

[0031] The functionalized polymer can have 0.01 to 50 wt% functional groups, where the weight percentage is based on the total amount of functionalized polymer. The functionalized polymer preferably has at least 0.05 wt% functional groups, and more preferably at least 0.1 wt% functional groups, where the weight percentage is based on the total amount of functionalized polymer. The functionalized polymer preferably has at most 40 wt% functional groups, more preferably at most 30 wt%, and even more preferably at most 20 wt% functional groups, where the weight percentage is based on the total amount of functionalized polymer.

[0032] The amount of functionalized polymer may be at least 0.01% by weight and at most 50% by weight, based on the total amount of condensation polymer, and may be preferably 0.01 to 30% by weight, more preferably 0.01 to 20% by weight, more preferably 0.01 to 10% by weight, and even more preferably 0.1 to 5% by weight, based on the total amount of condensation polymer.

[0033] The polyolefin fibers according to the invention may further comprise a thermoplastic polymer. Any thermoplastic polymer known in the art can be used in the HPPE fibers according to the invention, provided that it is soluble, preferably 100% soluble, in the (spinning) solvent as defined herein, preferably in a non-polar solvent.

[0034] Thermoplastic polymers: 875-1000 kg / m 3 Preferably, the thermoplastic polymer is a polymer having a density measured in accordance with ISO 1183-2004 in the range of 0.05 to 0.05 m / s. More preferably, the thermoplastic polymer is selected from the group consisting of homopolymers of ethylene, homopolymers of propylene, ethylene copolymers and propylene copolymers, and / or mixtures thereof.

[0035] The polymeric structure may further contain (individually) at least one additive. Any conventional additive known in the art can be used, such as ionic or non-ionic surfactants, tackifying resins, stabilizers such as UV stabilizers, flame retardants, antioxidants, colorants, reinforcing fillers such as inorganic fillers, or other additives that adjust the properties of the polymeric structure.

[0036] The polymeric structure containing the thermoplastic polymer and / or at least one additive may have a particle size, d50, as measured by SEM in accordance with the Examples section of this specification, of at least 50 nanometers and at most 1000 nanometers, preferably 100-600 nanometers, more preferably 100-500 nanometers, most preferably 150-400 nanometers, and even most preferably 150-250 nanometers. Large particle sizes (d50) tend to degrade the mechanical properties of HPPE fibers. Small particles have been found to reduce the dyeability of the fibers.

[0037] The total amount of all components of the polymeric structure according to the present invention, i.e., condensation polymer, functional polymer, and optionally at least one additive, is preferably 100% (provided that the additive is considered an integral part of the respective polymer).

[0038] The polyolefin fibers according to the invention may further comprise other fibers different from the fibers of the invention, for example fibers of different composition and / or shape, such as non-polymeric fibers, for example glass fibers, carbon fibers, basalt fibers, metal wire or thread fibers; and / or natural fibers, for example cotton; bamboo; and / or polymeric fibers, for example polyamide fibers such as nylon fibers, elastic fibers, for example elastane fibers, polyester fibers; and / or mixtures of these other fibers, which may be present in any proportion.

[0039] The present invention also relates to a process for producing the polyolefin fibers described herein, the process comprising: i) melt-mixing a condensation polymer, a functionalized polymer, and optionally a thermoplastic polymer and / or at least one additive to form a polymeric structure; ii) mixing a polyolefin powder, preferably UHMWPE powder, a polymeric structure, and a solvent for the polyolefin to form a mixture; and iii) spinning and drawing the mixture obtained in step ii) to form gel-spun polyolefin fibers, i.e., gel-spun HPPE fibers, comprising the polymeric structure of claim 1. Equipped with.

[0040] Alternatively, step ii) can be carried out by mixing the polyolefin powder with a solvent to form a first mixture; mixing the polymeric structure with a solvent to form a second mixture, and then mixing both the first and second mixtures together.

[0041] Preferably, in the case where the polymeric structure comprises at least one additive, step i) is preceded by step i'), which comprises melt-mixing the condensation polymer (which is the continuous phase) with at least one additive to form an additive-containing condensation polymer concentrate. The concentrate obtainable in step i') is a highly concentrated compound, i.e., it comprises or consists of at least 50% by volume, preferably at least 60% by volume, more preferably at least 80% by volume, and most preferably at least 90% by volume or at least 95% by volume, based on the total volume of the condensation polymer and additive. The amount of additive in the dispersion, in weight percent, typically depends on the density of the additive.

[0042] The condensation polymer or condensation polymer containing the additive dispersion obtained in step i'), the functionalized polymer and optionally the thermoplastic polymer are preferably mixed together at a temperature above the melting temperature (Tm) or glass transition temperature (Tg) to form a polymeric structure, in the case where all components are amorphous polymers.

[0043] The functional polymer may be added in an amount of at most 30%, preferably at most 20%, and most preferably at most 10% by weight, based on the total weight of the condensation polymer. The thermoplastic polymer may be added in an amount of at least 20% and at most 95%, preferably at least 30% and at most 90% by weight. The sum of all of these components desirably adds up to 100% (provided the additive is considered an integral part of the polymer).

[0044] The melt mixing step (sometimes referred to herein as liquid mixing, meaning mixing the components together in a molten state) can be carried out using any method, conditions and equipment known in the art, for example from patent document EP 1 492 843 B1. For example, melt mixing can be carried out in a twin-screw extruder or batch kneader at a speed of about 50 to 1200 rpm, in particular 100 to 400 rpm, with a temperature profile of 150 to 280° C. depending on the melt temperature of the components of the polymeric structure.

[0045] Step ii) is preferably carried out at a temperature higher than room temperature. The higher the temperature in step ii), the faster the mixing step. The maximum temperature in step ii) is the temperature at which the solvent begins to evaporate and may be limited by safe handling of the solvent, e.g., decalin. Higher temperatures may result in faster dissolution but may pose safety issues. The solvent used in step ii) is a solvent for polyolefins and a non-solvent for components in the polymer structure, e.g., condensation polymers.

[0046] Preferably, the process for producing gel-spun HPPE fibers described herein comprises the following steps: a) melt-mixing a condensation polymer or a condensation polymer containing at least one additive, a functionalized polymer, and optionally a thermoplastic polymer at a temperature that is the maximum of the melting temperature (Tm) or glass transition temperature (Tg) of all components to form a polymeric structure; b) dispersing the polymeric structure formed in step a) in a solvent (i.e., a polyolefin solvent) to form a suspension; c) separately forming a suspension of HPPE powder, preferably UHMWPE powder, and a solvent; d) adding the suspension of step b) to the suspension of step c) to form a mixture; and then e) Spinning and drawing the mixture obtained in step d) to form gel-spun HPPE fibers comprising the polymeric structure according to the present invention.

[0047] The gel-spun HPPE fibres according to the invention are obtained by a gel-spinning process and may contain at most 500 ppm of solvent as defined herein, preferably at most 400 ppm, more preferably at most 300 ppm, even more preferably at most 200 ppm, most preferably at most 100 ppm, and even most preferably at most 50 ppm.

[0048] Any gel-spinning process may be used to produce HPPE fibers according to the invention. Suitable gel-spinning processes are described, for example, in GB-A-2042414, GB-A-2051667, EP-A-0205960A and WO 01 / 73173 A1. Briefly, the gel-spinning process comprises preparing a solution of polyethylene with a high intrinsic viscosity and a solvent (solvent for the polyolefin, non-solvent for the condensation polymer) containing the polymer structure, extruding the solution into a molten fiber at a temperature above the dissolution temperature, cooling the molten fiber to a temperature below the gel temperature, thereby at least partially gelling the polyethylene of the fiber, and drawing the fiber before, during and / or after removing at least a portion of the solvent.

[0049] In the above-described methods for preparing HPPE fibers, drawing, preferably uniaxial drawing, of the resulting HPPE fibers may be carried out by means known in the art. Such means include extrusion drawing and tensile drawing in suitable drawing equipment. Drawing may be carried out in multiple steps to obtain increased mechanical tensile strength and stiffness.

[0050] In the case of the preferred UHMWPE fibers, drawing is typically carried out uniaxially in multiple drawing steps. The first drawing step, for example, involves drawing to a draw ratio (also called a draw ratio) of at least 1.5, preferably at least 3.0. Multiple drawing typically results in draw ratios of up to 9 for drawing temperatures up to 120°C, up to 25 for drawing temperatures up to 140°C, and 50 or greater for drawing temperatures of 150°C or greater. Multiple drawing at elevated temperatures may achieve draw ratios of about 50 or greater.

[0051] This process results in gel-spun HPPE fibers, preferably UHMWPE gel-spun fibers according to the invention, having a yarn tenacity of at least 1 N / tex, preferably at least 2 N / tex, more preferably at least 3 N / tex, even at least 3.5 N / tex or at least 4 N / tex.

[0052] Any solvent known in the art that is suitable for gel spinning HPPE and, in particular, UHMWPE may be used, hereinafter referred to as the "spinning solvent." The solvent is preferably any nonpolar solvent known in the art. Suitable examples of solvents include aliphatic and alicyclic hydrocarbons, including octane, nonane, decane, and paraffins and their isomers; petroleum distillates; mineral oil; kerosene; aromatic hydrocarbons, including toluene, xylene, and naphthalene and their hydrogenated derivatives, such as decalin and tetralin; halogenated hydrocarbons, such as monochlorobenzene; and cycloalkanes or cycloalkenes, such as carne, fluorine, camphene, menthane, dipentene, naphthalene, acenaphthalene, methylcyclopentadiene, tricyclodecane, 1,2,4,5-tetramethyl-1,4-cyclohexadiene, fluorenone, naphthoindane, tetramethyl-p-benzodiquinone, ethylfluorene, fluoranthene, and naphthenone. Similarly, the spin solvent combinations listed above can be used for gel spinning, and for brevity, the solvent combinations are also referred to as spin solvents. The process of the present invention has been found to be particularly advantageous for relatively volatile solvents such as decalin, tetralin, and some kerosene grades. Preferably, the solvent is decalin. The spin solvent can be removed by evaporation, extraction, or a combination of evaporation and extraction methods.

[0053] To obtain gel-spun HPPE fibers, standard equipment, preferably a twin-screw extruder, can be used, in the first section the polyolefin is dissolved in a solvent and at the end of the first section the fibers are fed into the extruder through a separate feed port.

[0054] HPPE fibers comprising the polymeric structure according to the invention may also be obtained using a masterbatch process.

[0055] Polyolefin fibers containing the polymeric structures according to the present invention can be converted into staple fibers, and these staple fibers can be processed into spun yarns.

[0056] The present invention also relates to articles comprising the polyolefin fibers of the present invention. The articles containing the fibers of the present invention may be, but are not limited to, products selected from the group consisting of fishing lines, fishing nets, ground nets, cargo nets, curtains, kite strings, dental floss, tennis racket strings, canvas, fabrics, woven fabrics, nonwoven fabrics, webbing, battery separators, medical devices, capacitors, pressure vessels, hoses, umbilical cables, automotive equipment, power transmission belts, building construction materials, cut-resistant articles, puncture-resistant articles, cut-resistant articles, protective gloves, composite sporting goods, skis, helmets, kayaks, canoes, bicycles, and boat hulls, speaker cones, high performance electrical insulators, radomes, sails, and ground sheets.

[0057] Fabrics that may contain polyolefin (HPPE) fibers according to the present invention may be woven or nonwoven and may be produced by any process known in the art. Fabrics may be made by knitting, weaving, or other methods using conventional equipment.

[0058] The polyolefin (HPPE) fibers according to the present invention may be coated or uncoated. A protective cover and / or coating may be applied to the surface of the HPPE fibers. Such a cover may be any known material, such as a knitted, woven, or braided fabric, for example, a woven or braided polyester abrasion-resistant UHMWPE fiber cover. The coating may be, for example, as described in WO 2014 / 064157 A1, or a crosslinked silicone coating as disclosed in WO 2011 / 015485, which is incorporated herein by reference.

[0059] The polyolefin (HPPE) fibers according to the present invention may be post-drawn to further increase their strength, preferably at a temperature in the range of 80 to 140° C., more preferably 90 to 130° C. Such post-drawing steps are described in the patent documents, e.g., EP 0 398 843 B1 and U.S. Pat. No. 5,901,632, which are incorporated herein by reference.

[0060] The present invention will be further illustrated by the following examples and comparative examples, but first the methods and materials used to determine various parameters useful in defining the present invention are listed below.

[0061] [method] dtex: The fiber fineness was measured by weighing 100 meters of fiber. The weight (in milligrams) was divided by 10 to calculate the dtex of the fiber. The heat of fusion and the melting peak temperature and Tg were determined according to standard DSC methods ASTM E794 and ASTM E793, respectively, at a heating rate of 10 K / min for the second heating curve and performed under nitrogen on dehydrated samples. The density of thermoplastic polymers was measured according to ISO1183-2004. The intrinsic viscosity (IV) of the UHMWPE powder was determined in decalin at 135 °C according to method ASTM D1601 (2004) for a dissolution time of 16 h, by extrapolating the viscosity measured at zero concentration from various concentrations using a 2 g / L BHT (butylhydroxytoluene) solution as an antioxidant. Tensile properties of HPPE fibers: Yarn tenacity or tensile strength (or tenacity) and tensile modulus (or modulus) were determined for HPPE multifilament yarns, as defined in ASTM D885M. A nominal fiber gauge length of 500 mm, a crosshead speed of 50% / min, and an Instron 2714 clamp with "Fibre Grip D5618C" were used. Based on the measured stress-strain curve, the modulus was determined as the slope between 0.3 and 1% strain. For the calculation of modulus and tensile strength, the measured tensile force was divided by the fineness determined above. Values ​​in GPa are calculated assuming a density of 0.97 g / cm for HPPE. 3 It can be calculated assuming that The number of olefin branches per 1000 carbon atoms is 1375 cm for a 2 mm thick compression molded film. -1The absorption at 1000 kJ / cm was quantified by FTIR and determined using a calibration curve for NMR measurements, for example as described in EP 0269151 (specifically, page 4 thereof). SEM: A section of approximately 1 x 1 cm was cut from the knitted fabric and embedded in epoxy resin. After curing at room temperature, a cross section was obtained using a diamond knife while cooling with LN2. The block surface of the obtained specimen was fixed in an SEM specimen holder and coated with a conductive carbon layer. Imaging was performed on an FEI Versa 3D FEGSEM at an accelerating voltage of 5 kV in combination with a retractable backscatter detector. Elemental composition was measured by EDX using EDAX TEAM software.

[0062] [material] [Condensation polymer (P1):] P1-1: Akulon® K122 (polyamide 6), marketed by DSM P1-2: Arnite® 1060, T04-200 (polybutylene terephthalate, PBT), marketed by DSM P1-3: Akulon® F136 (polyamide 6), marketed by DSM P1-4: Platamid® HX2544 (copolyamide PA-nylon grade), marketed by Arkema P1-5: Arnitel® EM740, marketed by DSM.

[0063] [Functional polymer (P2):] P2-1: Fusabond® MO525D (polyethylene grafted with 0.9 wt. % maleic anhydride, MA), commercially available from DuPont. P2-2: Lotader® 8840 (a reactor polymerized random copolymer of ethylene and glycidyl methacrylate (GMA) with a glycidyl methacrylate (GMA) content of 8% by weight), commercially available from Arkema.

[0064] [Thermoplastic polymer (P3):] P3-1: Queo 8201® (ethylene-based octene-1 plastomer, 28% octene, density 0.883 g / cm 3 , melting point peak temperature 74°C), commercially available from Borealis.

[0065] [Spinning solvent:] P4-1: Decalin

[0066] [Matrix polymer (HPPE):] M-1: UHMWPE powder with an IV of 19.0 dl / g. [Brief explanation of the drawings]

[0067] [Figure 1] 1 depicts a cross section of an HPPE fiber containing dispersed immiscible polymeric structures (1) or droplets (1), (2) refers to the HPPE optionally containing a thermoplastic polymer. [Figure 2] FIG. 1 shows a cross section of an HPPE fiber containing two adjacent polymeric structures or droplets, taken by energy dispersive X-ray (EDX) spectroscopy.

[0068] [Example] Five samples of polymeric structures in the form of solid mixtures were prepared via masterbatches by solid-state mixing in a tumbler with the raw materials in the amounts shown in Table 1. The resulting solid mixture was metered into a twin-screw extruder (ZE25UTS, manufactured by Berstorff) through the throat using a K-tron metering scale, where it was converted into five polymeric structure compositions (MB01 to MB05). Polyamide-based masterbatches (MB01, MB02, and MB03) were produced in an extruder with a throughput of 20 kg / h at a speed of 400 rpm. The temperatures in the feed, barrel, die, and discharge zones of the materials were 20, 240, 240, and 300 °C, respectively. Polyester-based masterbatches (MB04 and MB05) were produced in an extruder with a throughput of 23 kg / h at a speed of 300 rpm. The temperatures in the feed, barrel, die, and discharge zones of the materials were 20, 260, 260, and 295 °C, respectively.

[0069] [Table 1]

[0070] [Examples 1 to 10 (Ex. 1 to 10)] Each of the MB01-MB05 samples was then dissolved in approximately 15 liters of decalin batch (95 wt% batch and 5 wt% decalin) and stirred at approximately 110 °C under N for approximately 1 hour to form five different suspensions (Suspensions I-V).

[0071] Separately, a suspension of UHMWPE powder (M-1) was obtained in decalin with a concentration of 9% by weight (suspension VI).

[0072] Each of suspensions I to V was mixed with suspension VI in a twin-screw extruder with a screw diameter of 25 mm and equipped with a gear pump to form a mixture. Each of the resulting mixtures was then heated in this manner to a temperature of 180°C. The mixture was then pumped through a spinneret with 64 holes, each hole having a diameter of 1 mm. The filaments thus obtained were stretched a total of 80 times and dried in a hot air oven. After drying, the filaments were bundled and wound onto bobbins.

[0073] The compositions and properties of the fibers obtained in Examples 1 to 10 are shown in Table 2.

[0074] [Comparative Examples A to B (CE-A, CE-B)] CE-A was carried out in the same manner as described in Examples 1 to 10, with the only difference being that suspensions I to V were not used and only suspension VI was added to the extruder to form (unfilled) UHMWPE fibers.

[0075] CE-B: Carried out in the same manner as described in Examples 1 to 10, with the only difference that instead of suspensions I to V, inorganic particles of zeolite (commercially available from ACS Materials under the trade name Ultrastable Y Zeolite, particle size distribution d50 6 microns) were used and mixed with suspension VI to form zeolite-filled UHMWPE fibers.

[0076] The compositions and properties of the fibers obtained by CE A to B are shown in Table 2.

[0077] [Table 2]

[0078] [Examples 11 to 22] The HPPE fibers obtained from Examples 1-10 and CE-A and CE-B (Dyneema® 440-SK65 fibers) were then knitted on a flat knit 13 gauge Shima Seiki knitting machine into fabrics with an areal density of 260 grams per square meter in a single jersey construction.

[0079] The washed and rinsed fabric was then subjected to a coloring process based on dry fabric of Yorkshire's Dark Red Serilene FL dye at 2% by weight.

[0080] A dyeing assistant (2 g / l of Univadine DFM was used as a diffusing agent) and then the dye were successively added to the water in the dye bath at a temperature of 50°C. The amounts of assistant and dye were 2% by weight, respectively, based on the weight of the dried fabric. The pH was set to 4.5 using acetic acid. The rinsed fabric was then immersed in the dye bath (approximately 1 liter per 100 g of fabric), after which the dye bath temperature was increased (at a rate of 0.8°C / min) to 130°C and maintained at this temperature for 60 minutes. The bath was then rapidly cooled (at a rate of 2°C / min) to 60°C before draining. The dried fabric was rinsed successively with hot (70°C) and cold (15°C) water. The fabric thus obtained was air-dried for 24 hours at ambient conditions.

[0081] The colored fabrics so obtained were evaluated for color strength as reported in Table 3.

[0082] [Table 3]

[0083] The results obtained by applying the fibers according to the invention (Examples 1 to 10 and 13 to 22) compared with the results according to the prior art (CE-A, CE-B and Ex. 11 to 12) clearly show that fabrics containing HPPE fibers filled with polymeric structures according to the invention have good colorability and color fastness (i.e. ΔE cmc values ​​greater than 1, ΔE cmc is a known parameter used in the art and indicates the (visual) difference in color between fabrics; rub fastness and wash fastness values ​​of at least 3 to 4; and sublimation fastness values ​​of at least 3, see Table 3) and fiber yarn strength values ​​(Table 2) that remain at a very high level even when the amount of polymeric structure in the fiber is increased.

Claims

1. A polyolefin fiber comprising a polymeric structure, the polymeric structure comprising a condensation polymer and a functionalized polymer individually, the polyolefin fiber being a gel-spun high performance polyethylene (HPPE) fiber having a yarn tenacity of at least 1 N / tex, the polymeric structure being immiscible with and dispersed in the polyethylene fiber composition; the amount of the polymer structure in the polyethylene fibers is 0.001 to 20% by weight based on the total weight of the polyethylene fibers; the condensation polymer is selected from the group consisting of polyesters, polyamides, and copolymers thereof; A polyolefin fiber, wherein the functionalized polymer is selected from the group consisting of grafted (co)polyethylene and poly(glycidyl methacrylate).

2. 10. The polyolefin fiber of claim 1, wherein said gel-spun high performance polyethylene fiber is a gel-spun ultra-high molecular weight polyethylene fiber.

3. The polyolefin fiber of claim 1 further comprising a thermoplastic polymer.

4. 4. The polyolefin fiber according to claim 1, wherein said polymeric structures are dispersed particles or fibers in said HPPE fiber composition and further comprise at least one additive.

5. 5. The polyolefin fiber according to claim 1, wherein the amount of the condensation polymer is at least 0.1% by weight and at most 50% by weight, based on the total composition of the fiber.

6. 6. Polyolefin fiber according to any one of claims 1 to 5, wherein the amount of said functionalized polymer is at least 0.01% by weight and at most 50% by weight, based on the total amount of said condensation polymer.

7. The polyolefin fiber according to any one of claims 1 to 6, wherein the high-performance polyethylene fiber comprising the polymer structure has a yarn tenacity of at least 1.5 N / tex.

8. 4. The polyolefin fiber according to claim 3, wherein the polymeric structure has a particle size, d50, of at least 50 nanometers and at most 1000 nanometers.

9. The thermoplastic polymer has a viscosity of 875 to 1000 kg / m ３ 4. The polyolefin fiber of claim 3, which is any polymer having a density measured according to ISO 1183-2004 in the range of

10. 10. The polyolefin fiber according to claim 9, wherein the thermoplastic polymer is selected from the group consisting of homopolymers of ethylene, homopolymers of propylene, ethylene copolymers and propylene copolymers, and / or mixtures thereof.

11. A method for producing the polyolefin fiber according to any one of claims 1 to 10, comprising: i) melt-mixing the condensation polymer or the condensation polymer containing at least one additive and the functionalized polymer to form a polymeric structure; ii) mixing a polyolefin powder, the polymeric structure, and a solvent to form a mixture; and iii) spinning and drawing the mixture obtained in step ii) to form a polyolefin fiber comprising the polymeric structure of any one of claims 1 to 10; A method for providing

12. 12. The method of claim 11, wherein step ii) can be carried out by mixing the polyolefin powder and a solvent to form a first mixture, mixing the polymeric structure and a solvent to form a second mixture, and then mixing both the first and second mixtures together.

13. An article comprising the polyolefin fiber according to any one of claims 1 to 10.

14. The article of claim 13 , wherein the article is a fabric.

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