Tape for artificial turf

Abstract

The present disclosure provides a filament. In an embodiment, the filament is composed of a polyethylene composition. The polyethylene composition includes (a) from 15 to 25 percent by weight of a first polyethylene component having a molecular weight (Mw) greater than 200,000 g / mol and a density from 0.925 g / cc to 0.945 g / cc, (b) from 20 to 35 percent by weight of a second polyethylene component having a molecular weight (Mw) less than 80,000 g / mol and a density from 0.915 g / cc to 0.950 g / cc, and (c) from 40 to 65 percent by weight of a third polyethylene component having a molecular weight (Mw) less than 100,000 g / mol and a density from 0.940 g / cc to 0.965 g / cc. The polyethylene composition has a density from 0.935 g / cc to 0.958 g / cc, and a melt index (h) from 0.5 g / 10 min to 5.0 g / 10 min. The present disclosure also provides a backing layer for artificial turf. The backing layer is produced with filaments composed of the polyethylene composition.

Description

TAPE FOR ARTIFICAL TURFBACKGROUND

[0001] Conventional artificial turf is composed of different materials: (i) polyethylene in the yarn, (ii) polypropylene or polyester in the primary backing layer, and (iii) latex, polyurethane or polyolefin dispersion in the secondary backing layer. Recycle-ability is becoming a key driver in the artificial turf industry. Several materials in conventional artificial turf are not recyclable, such as polyester, latex, and polyurethane. In an effort towards recycle-ability, high density polyethylene (HDPE) has been proposed as an alternative material for the primary backing layer in artificial turf. Unfortunately, conventional HDPE deleteriously decreases elongation and increases the amount of shrinkage in the primary backing layer.

[0002] A need exists for an artificial turf that is recyclable. A need further exists for an allpolyethylene ("mono-material") artificial turf that can meet, or exceed, the performance parameters— durability, tenacity, elongation, and low shrinkage— of conventional artificial turf.SUMMARY

[0003] The present disclosure provides a filament. In an embodiment, the filament is composed of a polyethylene composition. The polyethylene composition includes (a) from 15 to 25 percent by weight of a first polyethylene component having a molecular weight (Mw) greater than 200,000 g / mol and a density from 0.925 g / cc to 0.945 g / cc, (b) from 20 to 35 percent by weight of a second polyethylene component having a molecular weight (Mw) less than 80,000 g / mol and a density from 0.915 g / cc to 0.950 g / cc, and (c) from 40 to 65 percent by weight of a third polyethylene component having a molecular weight (Mw) less than 100,000 g / mol and a density from 0.940 g / cc to 0.965 g / cc. The polyethylene composition has a density from 0.935 g / cc to 0.958 g / cc, and a melt index ( I2) from 0.5 g / 10 min to 5.0 g / 10 min. The present disclosure also provides a backing layer for artificial turf. The backing layer is produced with filaments composed of the polyethylene composition.

[0004] The present disclosure provides a backing layer. In an embodiment, the backing layer is composed of a polyethylene composition. The polyethylene composition includes (a) from 15 to 25 percent by weight of a first polyethylene component having a molecular weight (Mw) greater than 200,000 g / mol and a density from 0.925 g / cc to 0.945 g / cc, (b) from 20 to 35 percent by weight of a second polyethylene component having a molecular weight (Mw) less than 80,000 g / mol and a density from 0.915 g / cc to 0.950 g / cc, and (c) from 40 to 65 percent by weight of a third polyethylene component having a molecular weight (Mw) less than 100,000 g / mol and a density from 0.940 g / cc to 0.965 g / cc. The polyethylene composition has a density from 0.935 g / cc to 0.958 g / cc, and a melt index ( I2) from 0.5 g / 10 min to 5.0 g / 10 min. The backing layer is a backing layer for artificial turf.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 is a side elevational view of an artificial turf in accordance with an embodiment of the present disclosure.

[0006] FIG. 2 is a top plan view of a backing layer, in accordance with an embodiment of the present disclosure.

[0007] FIG. 3 is a schematic representation of a two-reactor polymerization system.DEFINITIONS

[0008] Any reference to the Periodic Table of Elements is that as published by CRC Press, Inc., 1990- 1991. Reference to a group of elements in this table is by the new notation for numbering groups.

[0009] For purposes of United States patent practice, the contents of any referenced patent, patent application or publication are incorporated by reference in their entirety (or its equivalent US version is so incorporated by reference) especially with respect to the disclosure of definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure) and general knowledge in the art.

[0010] The numerical ranges disclosed herein include all values from, and including, the lower and upper value. For ranges containing explicit values (e.g., a range from 1, or 2, or 3 to 5, or 6, or 7),any subrange between any two explicit values is included (e.g., the range 1-7 above includes subranges 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6; etc.).

[0011] Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percents are based on weight and all test methods are current as of the filing date of this disclosure.

[0012] The terms "comprising", "including", "having" and their derivatives do not exclude the presence of any additional component or procedure. The term, "consisting essentially of" excludes any other component or procedure, except those essential to operability. The term "consisting of" excludes any component or procedure not specifically stated.

[0013] The term "ot-olefin", as used herein, refers to an alkene having a double bond at the primary or alpha (a) position.

[0014] The terms "blend" and "polymer blend" mean a composition of two or more polymers. Such a blend may or may not be miscible. Such a blend may or may not be phase separated. Such a blend may or may not contain one or more domain configurations, as determined from transmission electron spectroscopy, light scattering, x-ray scattering, and any other method known in the art. Blends are not laminates, but one or more layers of a laminate may contain a blend. Such blends can be prepared as dry blends, formed in situ (e.g., in a reactor), melt blends.

[0015] The term, "ethylene / a-olefin interpolymer," as used herein, refers to an interpolymer that comprises, in polymerized form, a majority amount (>50 mol %) of units derived from ethylene monomer, and the remaining units derived from one or more a-olefins. Typical a-olefins used in forming ethylene / a-olefin interpolymers are C3-C10 alkenes.

[0016] The term, "ethylene / a-olefin copolymer," as used herein, refers to a copolymer that comprises, in polymerized form, a majority amount (>50 mol%) of ethylene monomer, and an a-olefin, as the only two monomer types.

[0017] An "ethylene-based polymer" or "polyethylene" refers to polymers comprising a majority amount (>50 mol %) of units which have been derived from ethylene monomer. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of polyethylene known in the art include Low DensityPolyethylene (LDPE); Linear Low Density Polyethylene (LLDPE); Ultra Low Density Polyethylene (ULDPE); single-site catalyzed Linear Low Density Polyethylene, including both linear and substantially linear low density resins (m-LLDPE); ethylene-based plastomers (POP) and ethylene-based elastomers (POE); Medium Density Polyethylene (MDPE); and High Density Polyethylene (HDPE). The following descriptions may be helpful in understanding the differences between some of these different polyethylene resins.

[0018] The term "LDPE" may also be referred to as "high pressure ethylene polymer" or "highly branched polyethylene" and is defined to mean that the polymer is partly or entirely homo-polymerized or copolymerized in autoclave or tubular reactors at pressures above 14,500 psi (100 MPa) with the use of free-radical initiators, such as peroxides (see for example US 4,599,392, which is hereby incorporated by reference). LDPE resins typically have a density in the range of 0.916 to 0.935 g / cm3.

[0019] The term "LLDPE", includes both resin made using the traditional Ziegler-Natta catalyst systems and chromium-based catalyst systems as well as single-site catalysts, including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, pyridylamine catalysts, phosphinimine catalysts & polyvalent aryloxyether catalysts (typically referred to as bisphenyl phenoxy), and includes linear, substantially linear or heterogeneous polyethylene copolymers or homopolymers. LLDPEs contain less long chain branching than LDPEs and includes the substantially linear ethylene polymers which are further defined in U.S. Patent 5,272,236, U.S. Patent 5,278,272, U.S. Patent 5,582,923 and US Patent 5,733,155; the homogeneously branched linear ethylene polymer compositions such as those in U.S. Patent No. 3,645,992; the heterogeneously branched ethylene polymers such as those prepared according to the process disclosed in U.S. Patent No. 4,076,698; and / or blends thereof (such as those disclosed in US 3,914,342 or US 5,854,045). The LLDPEs can be made via gas-phase, solution-phase or slurry polymerization or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0020] The term "MDPE" refers to polyethylenes having densities from 0.926 to 0.935 g / cm3. "MDPE" is typically made using chromium or Ziegler-Natta catalysts or using single-sitecatalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, pyridylamine catalysts, phosphinimine catalysts and polyvalent aryloxyether catalysts (typically referred to as bisphenyl phenoxy), and typically have a molecular weight distribution ("MWD") greater than 2.5.

[0021] The term "HDPE" refers to polyethylenes having densities greater than 0.935 g / cm3and up to 0.980 g / cm3, which are generally prepared with Ziegler-Natta catalysts, chrome catalysts or single-site catalysts including, but not limited to, substituted mono- or bis- cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, pyridylamine catalysts, phosphinimine catalysts and polyvalent aryloxyether catalysts (typically referred to as bisphenyl phenoxy).

[0022] The term "LILDPE" refers to polyethylenes having densities of 0.855 to 0.912 g / cm3, which are generally prepared with Ziegler-Natta catalysts, chrome catalysts, or single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, pyridylamine catalysts, phosphinimine catalysts & polyvalent aryloxyether catalysts (typically referred to as bisphenyl phenoxy). ULDPEs include, but are not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers. Polyethylene (ethylene-based) elastomers plastomers generally have densities of 0.855 to 0.912 g / cm3.

[0023] The term "multimodal" refers to compositions that can be characterized by having at least three (3) polymer subcomponents with varying densities and weight average molecular weights, and optionally, may also have different melt index values. In one embodiment, multimodal may be defined by having at least three distinct peaks in a Gel Permeation Chromatography (GPC) chromatogram showing the molecular weight distribution. In another embodiment, multimodal may be defined by having at least three distinct peaks in a Crystallization Elution Fractionation (CEF) chromatogram showing the short chain branching distribution. In another embodiment, multimodal may be defined by having at least three distinct peaks in an improved comonomer composition distribution (iCCD) elution profile.Multimodal includes compositions having three peaks as well as compositions having more or less than three peaks in GPC, CEF or iCCD, as long as the compositions can be characterized, in accordance with the test methods below, as having at least three (3) polymer subcomponents with varying densities and weight average molecular weights.

[0024] The term "trimodal polymer" refers to a multimodal ethylene-based polymer having three primary components: a first polyethylene component, a second polyethylene component, and a third polyethylene component. "Polyethylene component," for example, the "first polyethylene component," the "second polyethylene component," or the "third polyethylene component," refers to subcomponents of the polyethylene composition disclosed herein (i.e., the multimodal or trimodal polymer), wherein each subcomponent is a polyethylene comprising ethylene monomer and, optionally, C3-C12 a-olefin comonomer.

[0025] The terms "nonwoven," and "nonwoven web," are used herein interchangeably. "Nonwoven" refers to a web having a structure of individual fibers or threads which are randomly interlaid, but not in an identifiable manner as is the case for a knitted fabric.

[0026] An "olefin-based polymer" is a polymer that contains a majority mole percent polymerized olefin monomer (based on total amount of polymerizable monomers), and optionally, may contain at least one comonomer. Nonlimiting examples of olefin-based polymers include ethylene-based polymer and propylene-based polymer.

[0027] The term "polymer" is a macromolecular compound prepared by polymerizing monomers of the same or different type. "Polymer" includes homopolymers, copolymers, terpolymers, interpolymers, and so on. The term "interpolymer" means a polymer prepared by the polymerization of at least two types of monomers or comonomers. It includes, but is not limited to, copolymers (which usually refers to polymers prepared from two different types of monomers or comonomers, terpolymers (which usually refers to polymers prepared from three different types of monomers or comonomers), tetrapolymers (which usually refers to polymers prepared from four different types of monomers or comonomers), and the like.

[0028] A "propylene-based polymer" is a polymer that contains a majority amount (>50 mol%) of polymerized propylene and, optionally, may comprise at least one comonomer.Propylene-based polymers typically comprise at least 50 mole percent (mol%) units derived from propylene (based on the total amount of polymerizable monomers.

[0029] A "woven fabric" is a structure formed from warp yarn and weft yarn, the warp yarn and the weft yarn interlaced such that the warp yarns run lengthwise in the woven fabric and the weft yarns run perpendicular to the warp yarns.TEST METHODS

[0030] Decitex (dtex) is a unit of measurement for determining the linear density of a filament (or tape) and is defined as the mass (in grams) of the filament per 10,000 meters (m) of filament. For instance, a filament with a 168 dtex is a filament with a mass of 168 g per 10,000 m of filament.

[0031] Density. Density measurements are made to the overall polyethylene composition in accordance with ASTM D792, Method B. The data are reported in Table 1A. For the first and second polyethylene components, the density values are obtained using Equations 1-16 and the deconvolution methodology described below. For the third polyethylene component, the density value is calculated using Equations 15-16. Density is reported in grams per cubic centimeter (g / cc or g / cm3). The individual component density data are reported in Table 3.

[0032] Gel Permeation Chromatography (GPC) Conventional (Conv.). The chromatographic system consisted of a PolymerChar GPC-IR (Valencia, Spain) high temperature GPC chromatograph equipped with an internal IR5 infra-red detector (IR5). The autosampler oven compartment was set at 160°Celsius and the column compartment was set at 150°Celsius. The columns used were 4 Agilent "Mixed A" 30cm 20-micron linear mixed-bed columns. The chromatographic solvent used was 1,2,4 trichlorobenzene and contained 200 ppm of butylated hydroxytoluene (BHT). The solvent source was nitrogen sparged. The injection volume used was 200 microliters and the flow rate was 1.0 milliliters / minute.

[0033] Calibration of the GPC column set was performed with 21 narrow molecular weight distribution polystyrene standards with molecular weights ranging from 580 to 8,400,000 and were arranged in 6 "cocktail" mixtures with at least a decade of separation between individual molecular weights. The standards were purchased from Agilent Technologies. The polystyrenestandards were prepared at 0.025 grams in 50 milliliters of solvent for molecular weights equal to or greater than 1,000,000, and 0.05 grams in 50 milliliters of solvent for molecular weights less than 1,000,000. The polystyrene standards were pre-dissolved at 80 °C with gentle agitation for 30 minutes then cooled and the room temperature solution is transferred cooled into the autosampler dissolution oven at 160 °C for 30 minutes. The polystyrene standard peak molecular weights were converted to polyethylene molecular weights using Equation 1 (as described in Williams and Ward, J. Polym. Sci., Polym. Let., 6, 621 (1968)).:

[0034]

[0035] where M is the molecular weight, A has a value of 0.4129 and B is equal to 1.0.

[0036] A fifth order polynomial was used to fit the respective polyethylene-equivalent calibration points. The total plate count of the GPC column set was performed with decane which was introduced into blank sample via a micropump controlled with the PolymerChar GPC-IR system. The plate count for the chromatographic system should be greater than 18,000 for the 4 Agilent "Mixed A" 30cm 20-micron linear mixed-bed columns.

[0037] Samples were prepared in a semi-automatic manner with the PolymerChar "Instrument Control" Software, wherein the samples were weight-targeted at 2 mg / ml, and the solvent (contained 200ppm BHT) was added to a pre nitrogen-sparged septa-capped vial, via the PolymerChar high temperature autosampler. The samples were dissolved for 2 hours at 160°Celsius under "low speed" shaking.

[0038] The calculations of Mn(GPc), Mw(GPc),and MZ(GPC) were based on GPC results using the internal IR5 detector (measurement channel) of the PolymerChar GPC-IR chromatograph according to Equations 2-4, using PolymerChar GPCOne™ software, the baseline-subtracted IR chromatogram at each equally-spaced data collection point (i), and the polyethylene equivalent molecular weight obtained from the narrow standard calibration curve for the point (i) fromEquation 1.

[0039]

[0040]

[0041]

[0042] In order to monitor the deviations over time, a flowrate marker (decane) was introduced into each sample via a micropump controlled with the PolymerChar GPC-IR system. This flowrate marker (FM) was used to linearly correct the pump flowrate (Flowrate(nominal)) for each sample by RV alignment of the respective decane peak within the sample (RV(FM Sample)) to that of the decane peak within the narrow standards calibration (RV(FM Calibrated)). Any changes in the time of the decane marker peak are then assumed to be related to a linear-shift in flowrate (Flowrate(effective)) for the entire run. After calibrating the system based on a flow marker peak, the effective flowrate (with respect to the narrow standards calibration) is calculated as Equation 5. Processing of the flow marker peak was done via the PolymerChar GPCOne™ Software. Acceptable flowrate correction is such that the effective flowrate should be within + / -0.5% of the nominal flowrate.

[0043] Flowrate(effective) = Flowrate(nominal) * (RV(FM Calibrated) / RV(FM Sample)) (EQ 5)

[0044] GPC measurements are done on both the overall polyethylene composition and the polymer sampled from the first reactor containing the first and second polyethylene components.

[0045] Improved method for comonomer content analysis (iCCD). Improved method for comonomer content analysis (iCCD) was developed in 2015 (Cong and Parrott et al., W02017040127A1). iCCD test was performed with Crystallization Elution Fractionation instrumentation (CEF) (PolymerChar, Spain) equipped with I R-5 detector (PolymerChar, Spain) and two angle light scattering detector Model 2040 (Precision Detectors, currently AgilentTechnologies). A guard column packed with 20-27-micron glass (MoSCi Corporation, USA) in a 5 cm or 10 cm (length)Xl / 4" (ID) stainless was installed just before I R-5 detector in the detector oven. Ortho-dichlorobenzene (ODCB, 99% anhydrous grade or technical grade) was used. Silica gel 40 (particle size 0.2~0.5 mm, catalogue number 10181-3) from EMD Chemicals was obtained (can be used to dry ODCB solvent before). Dried silica was packed into three emptied HT-GPC columns to further purify ODCB as eluent. The CEF instrument is equipped with an autosampler with N2 purging capability. ODCB is sparged with dried nitrogen (N2) for one hour before use. Sample preparation was done with autosampler at 4 mg / ml (unless otherwise specified) under shaking at 160°C for 1 hour. The injection volume was 300pl. The temperature profile of iCCD was crystallization at 3°C / min from 105°C to 30°C, the thermal equilibrium at 30°C for 2 minute (including Soluble Fraction Elution Time being set as 2 minutes), elution at 3°C / min from 30°C to 140°C. The flow rate during crystallization is 0.0 ml / min. The flow rate during elution is 0.50 ml / min. The data was collected at one data point / second.

[0046] The iCCD column was packed with gold coated nickel particles (Bright 7GNM8-NiS, Nippon Chemical Industrial Co.) in a 15cm (length)Xl / 4" (ID) stainless tubing. The column packing and conditioning were with a slurry method according to the reference (Cong, R.; Parrott, A.; Hollis, C.; Cheatham, M. W02017040127A1). The final pressure with TCB slurry packing was 150 Bars.

[0047] Column temperature calibration was performed by using a mixture of the Reference Material Linear homopolymer polyethylene (having zero comonomer content, Melt index (12) of 1.0, polydispersity Mw / Mn approximately 2.6 by conventional gel permeation chromatography, l.Omg / ml) and Eicosane (2mg / ml) in ODCB. iCCD temperature calibration consisted of four steps: (1) Calculating the delay volume defined as the temperature offset between the measured peak elution temperature of Eicosane minus 30.00° C; (2) Subtracting the temperature offset of the elution temperature from iCCD raw temperature data. It is noted that this temperature offset is a function of experimental conditions, such as elution temperature, elution flow rate, etc.; (3) Creating a linear calibration line transforming the elution temperature across a range of 30.00° C and 140.00° C so that the linear homopolymer polyethylene reference had a peak temperature at 101.0°C, and Eicosane had a peaktemperature of 30.0° C; (4) For the soluble fraction measured isothermally at 30° C, the elution temperature below 30.0° C is extrapolated linearly by using the elution heating rate of 3° C / min according to the reference (Cerk and Cong et al., US9,688,795).

[0048] The comonomer content versus elution temperature of iCCD was constructed by using 12 reference materials (ethylene homopolymer and ethylene-octene random copolymer made with single site metallocene catalyst, having ethylene equivalent weight average molecular weight ranging from 35,000 to 128,000). All of these reference materials were analyzed the same way as specified previously at 4 mg / mL. The reported elution peak temperatures followed the figure of octene mole% versus elution temperature of iCCD at R2 of 0.978.

[0049] Molecular weight of polymer and the molecular weight of the polymer fractions was determined directly from LS detector (90 degree angle) and concentration detector (IR-5) according Rayleigh-Gans-Debys approximation (Striegel and Yau, Modern Size Exclusion Liquid Chromatogram, Page 242 and Page 263) by assuming the form factor of 1 and all the virial coefficients equal to zero. Integration windows are set to integrate all the chromatograms in the elution temperature (temperature calibration is specified above) range from 23.0 to 120°C.

[0050] The calculation of Molecular Weight (Mw) from iCCD includes the following steps: Measuring the interdetector offset. The offset is defined as the geometric volume offset between LS with respect to concentration detector. It is calculated as the difference in the elution volume (mL) of polymer peak between concentration detector and LS chromatograms. It is converted to the temperature offset by using elution thermal rate and elution flow rate. A linear high density polyethylene (having zero comonomer content, Melt index (12) of 1.0, polydispersity Mw / Mn approximately 2.6 by conventional gel permeation chromatography) is used. Same experimental conditions as the normal iCCD method above are used except the following parameters: crystallization at 10°C / min from 140°C to 137°C, the thermal equilibrium at 137°C for 1 minute as Soluble Fraction Elution Time, soluble fraction (SF) time of 7 minutes, elution at 3°C / min from 137°C to 142°C. The flow rate during crystallization is 0.0 ml / min. The flow rate during elution is 0.80 ml / min. Sample concentration is l.Omg / ml. Each LS datapoint in LS chromatogram is shifted to correct for the interdetector offset before integration.Baseline subtracted LS and concentration chromatograms are integrated for the whole eluting temperature range of the Step (1). The MW detector constant is calculated by using a known MW HDPE sample in the range of 100,000 to 140,000 Mw and the area ratio of the LS and concentration integrated signals. Mw of the polymer was calculated by using the ratio of integrated light scattering detector (90 degree angle) to the concentration detector and using the MW detector constant.

[0051] The molecular weight calculations and calibrations were performed in GPCOne® software.

[0052] iCCD measurements are done on both the overall polyethylene composition and the polymer sampled from the first reactor containing the first and second polyethylene components.

[0053] Numerical Deconvolution of Bivariate Data. Numerical Deconvolution of Bivariate Data is used to obtain the density, molecular weight (Mw), and melt index (L) of the first polyethylene component, the second polyethylene component, and the third polyethylene component. Numerical deconvolution of the combined iCCD-SCBD (wtjcco(T) vs. temperature (T) plot from iCCD) and GPC-MWD (wtGPc(lgMW)) vs. IgMW plot from conventional GPC) data was performed using Microsoft Excel* Solver (2018). For iCCD-SCBD, the calculated weight fraction (wtSUm,iccD(T)) versus temperature (T) data obtained using the method described in the iCCD section (in the range of approximately 23 to 120 °C) was quelled to approximately 200 equally-spaced data points in order for a balance of appropriate iterative speed and temperature resolution. A single or series (up to 3 peaks for each component) of Exponentially- Modified Gaussian Distributions (Equation 6) were summed to represent each component (wtc,icco(T)), and the components were summed to yield the total weightat any temperature (T) as shown in Equation 7A-D.

[0054]

[0055] where C means component (C=1, 2 or 3), P means peak (P=1, 2, or 3), ao,c,p is the chromatographic area in °C for the P-th peak of the C-th component, ai,c,p is the peak center in °C for the P-th peak of the C-th component, a2,c,p is the peak width in °C for the P-th peak of theC-th component, a3,c,p is the peak tailing in °C for the P-th peak of the C-th component, and T is the elution temperature in °C. In the case of a single Exponentially-Modified Gaussian Distributions is used to represent the iCCD-SCBD of a component, yr,c,2=yr,c,3=0. In the case of two Exponentially-Modified Gaussian Distributions are used to represent the iCCD-SCBD of a component, only yr, c, 3=0.

[0056]

[0057]

[0058]

[0059]

[0060] Weight fraction of each component from iCCD-SCBD deconvolution canbe expressed by

[0061]

[0062]

[0063]

[0064]

[0065] where is the weight fraction of the first polyethylene component obtainedfrom iCCD-SCBD deconvolution, is the weight fraction of the second polyethylenecomponent obtained from iCCD-SCBD deconvolution, is the weight fraction of the thirdpolyethylene component obtained from iCCD-SCBD deconvolution, and the sum of the fractions is normalized to 1.00.

[0066] For GPC-MWD, the MWD obtained by the Conventional GPC description section was imported into the same spreadsheet in 0.01 lg(MW / (g / mol)) increments between 2.00 and 7.00 (501 data points total). A Flory-Schulz Distribution with a weight-average molecular weight of Mw, Target and a polydispersity (Mw / Mn) of 2.0 is shown in the following equations. i

[0067]

[0068]

[0069]

[0070] where is the weigh fraction of the molecules at lg(Mj / (g / mol)) (Mi in g / mol), iis integers ranging from 0 to 500 to represent each data point on the GPC-MWD plot and corresponding lg(M i / (g / mol)) is 2+O.Olxj.

[0071] The Flory-Schulz Distribution is subsequently broadened using a sum of a series normal distribution at each lg(Mj / (g / mol)). The weight fraction of the Normal Distribution with its peak value at lg(Mi / (g / mol)) is kept the same as the original Flory-Schulz Distribution. The broadened Flory-Schulz Distribution curve can be described as the following equation.

[0072]

[0073] where is the weight fraction of the molecules atlg(Mj / (g / mol)), j is integers ranging from 0 to 500, o is the standard deviation of the Normal Distribution. Therefore, molecular weight distribution curves for all three components can be expressed as the following equations. Number-average molecular weight (Mn(GPc)), weightaverage molecular weight (MW(GPC)), and MWD (Mw(GPC) / Mn(GPC)) can be calculated from the broadened Flory-Schulz Distribution.(Equation 13C)

[0077]

[0078] where a is the normal distribution width parameter, the subscripts Cl, C2 and C3 represent the first, the second and the third polyethylene components, respectively. wfci,GPc> wfc^pc and W / C3,GPC are the weight fractions of the first, the second and the third polyethylene components from GPC-MWD, respectively.

[0079] Each of the paired components (the first polyethylene component (Cl), the second polyethylene component (C2), and third polyethylene component (C3)) from iCCD-SCBD and GPC-MWD are considered equivalent masses for their respective techniques as shown inEquations 14A-E.

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] Process and catalyst data, including catalysts efficiency and reactor mass balance, can be leveraged for initial estimates of the relative weight production of each component. Alternatively, initial estimates of the weight fraction for each component can be compared by integrating partial areas of the iCCD-SCBD or GPC-MWD plot of the polyethylene composition, especially noting visible areas with defined peaks or peak inflection points. For example, the peak area for each component in iCCD-SCBD curve, if well-separated may be estimated by dropping vertical lines between peaks. Figure 2 in both patent publications W0201913394A1 and W02019133373A1 provide an example of an iCCD-SCBD curve. These publications are incorporated herein in their entirety. Association of the molecular weight order and initial estimation of the molecular weight may be obtained from the peak positions of the associated component areas in the iCCD-SCBD and iCCD-MW plots and agreement should be expected with the GPC-CC measurements. In some cases, initial assignment of peak areas and composition may be obtained from a multi-modal GPC-MWD as the starting point and validated under the iCCD-SCBD and iCCD-MW plots.

[0086] Initial estimates of peak elution temperature, width, and tailing in iCCD-SCBD for each component can be obtained from a calibration of peak elution temperature, width, and tailing using a series of standard single-site samples for which we have a measured weight percent comonomer content by NMR. These calibrations can also inform about individual component comonomer content from the measured peak elution temperature.

[0087] Microsoft Excel* Solver is programmed to minimize the combined sum of squares of residuals between the and the measured GPC-MWD, and sum of squares ofresiduals between the and the measured iCCD-SCBD (wherein the sampling widthand areas of the two observed distributions are normalized in regards to each other). There is equal weighting given to the GPC-MWD and iCCD-SCBD fit as they are simultaneously converged. Initial estimated values for weight fraction and peak width in iCCD-SCBD as well as molecular weight target for each component are used for the Microsoft Excel* Solver to begin with as described herein.

[0088] Co-crystallization effects which distort peak shape in iCCD are compensated for by the use of the Exponentially-Modified Gaussian (EMG) peak fit and in extreme cases, the use of multiple (up to 3) EMG peaks summed to describe a single component. A component produced via a single site catalyst may be modeled by a single EMG peak. A component produced via a Ziegler-Natta catalyst may be modeled by 1, 2, or 3 EMG peaks, or a single EMG peak possessing a long low temperature-facing tail sufficing for a Ziegler-Natta component of very high density, very low molecular weight targets on the iCCD-SCBD plot. In all cases, only a single broadened Flory-Schulz distribution (Equation 13A-C) is used with the weight fraction assigned as the associated sum of one or more of the EMG components from the iCCD-SCBD model (Equations 14A-E).

[0089] The GPC deconvolution is constrained with a normal distribution width parameter or from Equation 13A, 13B between 0.000 and 0.170 (corresponding polydispersities of approximately 2.00 to 2.33) for the first and second polyethylene components which are made via single site catalysts. Thein Equation 9 is constrained to be lowest for the third polyethylene component in these cases, since it is targeted to be the lowest from this specific reaction scheme. Note that it is not constrained to be lowest in all possible cases, depending upon the desired performance target of the combined resin in-reactor blend. The ranking (preliminary estimation) of the two weight-average molecular weights of thefirst polyethylene component and the second polyethylene component is observed by the from the iCCD-MW plot (MWOCCD) VS. temperature curve) at the temperatures at whichthe first and second polyethylene component peaks are observed on the iCCD-SCBD plot. temperature curve). Therefore, the order of the molecular weights for the three components is well-known. A reactor mass balance yields the percentage mass (Wf) of Equation 13C of the third polyethylene component, or alternatively it can be calculated from the deconvolution using Equation 13D, depending upon the strength of the known distribution models for iCCD and GPC and the total weight fraction must sum to unity (Equation 14 A-E).

[0090] In general, it has been found that approximately 20 solver iterations will typically reach good convergence on the solution using Excel*. If there is a disagreement in order of the peaks versus measured molecular weight by the iCCD-MW plot and the observed comonomer wt.% measurement measured via GPC-CC, then the data must be reconciled by changing the iteration starting points (temperature or logMW) in Excel or changing the width and tail factors slightly such that the iteration will proceed with convergence to a consistent solution amongst the measurements, or the resolution of the measurements must be increased, or an additional peak may be added to the iCCD-SCBD to better approximate the elution peak shape of the individual components. Such components could be modeled a-priori via several EMG distributions if they are prepared individually.

[0091] Additionally, a predictedponse for iCCD-MW may be generated by using the weight-average molecular weight by GPC-MWD of each of the components multiplied by the observed weight fraction of each of the components at each point along the iCCD-SCBD plot. The predictedneeds to agree with the measured M in the iCCD-MW plot.By plotting comonomer incorporation as a function of elution temperature based on a series of known copolymer standards, the GPC-CC plot can also be predicted using the measured MW(iccD) and comonomer incorporation of individual component from iCCD-MW and iCCD-SCBD plots. The predicted GPC-CC plot needs to agree with the measured GPC-CC.

[0092] A peak temperature vs. density correlation for the iCCD-SCBD data is obtained using a series of linear ethylene-based polymer standard resins polymerized from single site catalysts of approximately 1 g / lOmin melt index ( I2), or nominal weight-average molecular weight of approximately 105,000 g / mol by GPC, and polydispersities (or MWD) of less than 2.3 by GPC. At least 10 standard resins of known comonomer content, density, and molecularweight within the density range of 0.87 to 0.96 g / cc are used. Peak temperature and density data are fit with a 5th order polynomial curve to obtain the calibration curve.

[0093] A peak width and peak tail vs. peak temperature correlation is obtained similarly by fitting the peak width and peak tail vs. temperature of the above resins with a linear line, which is very useful for initial estimates in the deconvolution process.

[0094] The first polyethylene component and the second polyethylene component were noted in the inventive resins presented herein directly from the iCCD-SCBD deconvolution plot as the first two peaks between 35°C and 90 °C elution temperature. A "Raw Density" (DensityRaw) was calculated from these observed peak positions using the calibration curve of peak temperature vs. density. The DensityRaw (in g / cc) was corrected to Densityirue (in g / cc) accounting for molecular weight (in g / mol) contributions by using the Equation 15:

[0095]

[0096] whereis the weight-average molecular weight of the single component deconvoluted from GPC-MWD.

[0097] The density of the third polyethylene component may be calculated based on the known density of the resin, Densityirue of the first polyethylene component, Densityirue of the second polyethylene component, and the weight fractions of each component according to the following Equation 16.

[0098] (Equation 16)

[0099] The melt index ( I2) of each polyethylene component may be estimated from their weight-average molecular weight by the following equation:where is the weight average molecular weight (in g / mol) of the single componentdeconvoluted from GPC-MWD curve and I2 is the melt index in (g / lOmin). Note that the amount of long chain branching may change the coefficients. Moreover, for the determination of product composition, direct sampling of a single reactor with a single catalyst with the same reactor conditions, a first reactor sampling for a series dual-reactor configuration, or sampling of both reactors for a parallel dual-reactor configuration may be used to aid in the determination of the density, melt index (I2), GPC-MWD, and iCCD-SCBD of each individual component of the polyethylene composition, especially providing that the reaction is effectively killed past the sampling point. This allows better confirmation in cases, wherein the first and second polyethylene component peak positions cannot adequately be determined from the 3-component mixture.

[0100] Direct examination and quantitation by analytical cross-fractionation in GPC-TREF, such as the PolymerChar CFC unit (Valencia, Spain) equipped with on-line light scattering and employing similar calibrations in bivariate space representing SCBD and molecular weight and calibrating the relationship to density may be used to measure amounts or discriminate more precisely of each of the components as well, especially for the initial estimates or in cases that may produce high co-crystallization or low resolution / discrimination of species particularly in both MWD and SCBD space. (Development of an Automated Cross-Fractionation Apparatus (TREF-GPC) for a Full Characterization of the Bivariate Distribution of Polyolefins. Polyolefin Characterization. Macromolecular Symposia, Volume 257, 2007, Pages 13-28. A. Ortfn, B. Monrabal, J. Sancho-Tello) Adequate resolution must be obtained in both IgMW and temperature space and verification should be done through both direct compositional ratioing, for example, IR-5 and light scattering molecular weight measurement. See Characterization of Chemical Composition along the Molar Mass Distribution in Polyolefin Copolymers by GPC Using a Modern Filter-Based IR Detector. Polyolefin Characterization - ICPC 2012 Macromolecular Symposia Volume 330, 2013, Pages 63-80, A. Ortfn, J. Montesinos, E. Lopez, P. del Hierro, B. Monrabal, J.R. Torres-Lapasio, M.C. Garcia-Alvarez-Coque. Deconvolution ofthe components must use a similar set of equations and analogous calibration verified by a series of single-site resins and resin blends.

[0101] Branching Measurements. The GPC system consists of a 150 °C high temperature chromatograph equipped with a Polymer Char IR-5 infrared detector, a two-angle light scattering detector (Agilent 1260) and a differential viscometer from Polymer Char. Four PL Mixed A columns (7.5 x 300 mm), commercially available from Agilent, are installed in series before the IR-5 detector in the detector oven. 1,2,4-trichlorobenzene (TCB, HPLC grade) and 2,5-di-tert-butyl-4-methylphenol (BHT) (such as commercially available from Sigma-Aldrich) are obtained. Eight hundred milligrams of BHT are added to four liters of TCB. TCB containing BHT is now referred to as "TCB." Sample preparation is done with an autosampler at 2 mg / mL under shaking at 160 °C for 3 hours. The injection volume is 200 ml. The temperature of GPC is 150 °C and the flow rate is 1 mL / min. The GPC is calibrated using a series of narrow molecular weight (Mw) polystyrene standards.

[0102] Calibration of the GPC column set is performed with 21 narrow molecular weight distribution polystyrene standards with molecular weights ranging from 580 to 9,835,000 and are arranged in six "cocktail" mixtures with at least a decade of separation between individual molecular weights. A fifth order polynomial is used to fit the respective polyethylene-equivalent calibration points. The polystyrene standard peak molecular weights are converted to polyethylene molecular weights.

[0103] IR-5 infrared detector is used to measure the composition along with MWD. The composition detector is calibrated using a series of copolymer standards having varying levels of co-monomer. The wt% co-monomer levels of these samples are obtained by C13NMR. For each standard, the composition related signals are collected, labelled as "Measurement", "Methylene" (CH2) and "Methyl" (CH3). The "Measurement" signal is used as concentration signal when performing molecular weight calibration, while the ratio of the "Methyl" and "Methylene" signals are used for the composition calculation. Plots of the wt% co-monomer from NMR versus these ratios for the series of standards are made. A linear regression of the data results in good fits of the data sets.

[0104] Melt Index. Melt index (I2) values are measured in accordance to ASTM D1238 at 190°C at 2.16 kg. Similarly, melt index (I10) values are measured in accordance to ASTM D1238 at 190°C at 10 kg. The values are reported in g / 10 min, which corresponds to grams eluted per 10 minutes. These data are collected for the overall polyethylene compositions and reported in Table 2. The melt index (I2) values for the first polyethylene component, the second polyethylene component, and the third polyethylene component are calculated according to Equations 15-16 and the deconvolution methodology described above and are shown in Table 3.

[0105] Shrinkage. One meter of tape is cut and immersed into a hot oil bath at 90 °C for 20 seconds. Tape is removed from the bath, manually dried and re-measured for length. Thermal shrinkage is expressed as the percentage of length reduction before and after the immersion: Thermal shrinkage=(length before-length afterj / length before*100%.

[0106] Tenacity and Elongation. A single tape of 250 mm length is measured in a Zwick tensile dynamometer at 250 mm / min until the fiber breaks. Tenacity is defined as the tensile force at break divided by the linear weight and expressed in cN / dtex where "cN" is centi-Newton. Ultimate elongation is the strain at fiber break, expressed in percentage of deformation.DETAILED DESCRIPTION

[0107] The present disclosure provides a filament. In an embodiment, the filament is composed of a polyethylene composition. The polyethylene composition includes (a) from 15 percent to 25 percent by weight of a first polyethylene component. The first polyethylene component has a molecular weight (Mw) greater than 200,000 g / mol and a density from 0.925 g / cc to 0.945 g / cc. The polyethylene composition includes (b) from 20 percent to 35 percent by weight of a second polyethylene component. The second polyethylene component has a molecular weight (Mw) less than 80,000 g / mol and a density from 0.915 g / cc to 0.950 g / cc. The polyethylene composition includes (c) from 40 percent to 65 percent by weight of a third polyethylene component. The third polyethylene component has a molecular weight (Mw) less than 100,000 g / mol and a density from 0.940 g / cc to 0.965 g / cc. The polyethylene composition has a density of from 0.935 g / cc to 0.958 g / cc, and a melt index (I2) of from 0.5 to 5.0 g / 10 min.1. Filament

[0108] A "filament" as used herein, is a unidirectional oriented elongated strand of cast- extruded polymeric material having a linear density from 100 dtex to 2500 dtex. The filament can be a monofilament, a slit film, or a tape.

[0109] In an embodiment, the filament is a tape. A "tape," as used herein, is a unidirectional oriented elongated strand of cast-extruded polymeric material with opposing parallel, or substantially parallel, sides, and a linear density from 100 dtex to 2500 dtex. A tape typically has a length to diameter ratio greater than 10. A tape typically has a polygonal, square, or rectangular, or otherwise a flat ( / .e., "ribbon" like) cross-sectional shape. The tape has a thickness from 50 pm to 120 pm, or from 70 pm to 100 pm, and a width from 0.1 mm to 5 mm, or from 0.5 mm to 3 mm. The tape is typically oriented (or otherwise stretched) in the machine direction to provide desired properties, such as elongation, and / or tenacity.

[0110] In an embodiment, the tape has a linear density from 300 dtex to 1500 dtex, or from 700 dtex to 1500 dtex.2. Polyethylene composition

[0111] The filament (or the tape) is composed of the polyethylene composition. The polyethylene composition is the polymerized reaction product of ethylene monomer and at least one C3-C12 a-olefin comonomer, or at least one C4-C8 a-olefin comonomer. Nonlimiting examples of suitable a-olefin comonomer include propylene, 1-butene, 1-hexene, and 1- octene,and combinations thereof; or 1-butene, 1-hexene, 1-octene, and combinations thereof; or 1-hexene, 1-octene, and combinations thereof, or 1-octene.

[0112] The polyethylene composition has three components: (a) a first polyethylene component, (b) a second polyethylene component, and (c) a third polyethylene component. The polyethylene composition includes (a) from 15 percent to 25 percent by weight, based on total weight of the polyethylene composition, of the first polyethylene component having a weight average molecular weight (Mw) greater than 200,000 g / mol and a density of from 0.925 to 0.945 g / cc. All individual values and subranges of from 15 to 25 percent by weight are disclosed and included herein. For example, the polyethylene composition can include from 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 to 25, 24, 23, 22, 21, 20, 19, 18, 17, or 16 percent by weight, based on totalweight of the polyethylene composition, of the first polyethylene component. The first polyethylene component can have a Mw of greater than 200,000 g / mol, or greater than 210,000 g / mol, or greater than 250,000 g / mol, or greater than 280,000 g / mol, or greater than 300,000 g / mol, or greater than 310,000 g / mol, or from 210,000 g / mol to 400,000 g / mol. The first polyethylene component can have a density from 0.925 to 0.945 g / cc, or from 0.930 to 0.945 g / cc, or from 0.930 to 0.940 g / cc. The densities for the polyethylene composition components (for example, first, second, and third polyethylene components) are calculated from the equations provided in the test methods section.

[0113] In an embodiment, the first polyethylene component has a peak temperature in an elution profile via improved comonomer composition distribution (iCCD) of greater than 99.5°C. In some embodiments, the first polyethylene component is a homopolymer. In some embodiments, the first polyethylene component can include a C3-C12 a-olefin comonomer. Exemplary a-olefin comonomers include, but are not limited to, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 4-methyl-l-pentene. The one or more a-olefin comonomers of the first polyethylene component may be selected from the group consisting of propylene, 1-butene, 1-hexene, and 1-octene, or in the alternative, from the group consisting of 1-butene, 1-hexene and 1-octene, or in the alternative, from the group consisting of 1-hexene and 1-octene.

[0114] The polyethylene composition includes (b) from 20 percent to 35 percent by weight of a second polyethylene component having a molecular weight (Mw) less than 80,000 g / mol and a density from 0.915 to 0.950 g / cc. All individual values and subranges of from 20 to 35 percent by weight are disclosed and included herein. For example, the polyethylene composition can comprise from 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, or 34 to 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, or 21 percent by weight, based on the total weight of the polyethylene composition, of a second polyethylene component. The second polyethylene component can have Mw less than 80,000 g / mol, or less than 70,000 g / mol, or less than 60,000 g / mol, or less than 55,000 g / mol, or from 15,000 g / mol to 75,000 g / mol. The second polyethylene component can have a density from 0.915 to 0.950 g / cc, or from 0.915 to 0.940 g / cc, or from 0.915 to 0.935 g / cc, or from 0.915 to 0.930 g / cc, or from 0.915 to 0.925 g / cc.

[0115] The second polyethylene component can have various levels of C3-C12 a-olefin comonomer incorporation. In one embodiment, the second polyethylene component can have a higher C3-C12 a-olefin comonomer incorporation than the first polyethylene component. For example, the second polyethylene component can have 2 to 20 percent by weight of C3-C12 a- olefin comonomer, or from 3 to 19 percent by weight of C3-C12 a-olefin comonomer, or from 5 to 17 percent by weight of C3-C12 a-olefin comonomer. The one or more a-olefin comonomers of the second polyethylene component may be selected from the group consisting of propylene, 1-butene, 1-hexene, and 1-octene, or in the alternative, from the group consisting of 1-butene, 1-hexene and 1-octene, or in the alternative, from the group consisting of 1-hexene and 1- octene.

[0116] The polyethylene composition includes (c) from 40 percent to 65 percent by weight of a third polyethylene component having a molecular weight (Mw) of less than 100,000 g / mol and a density of from 0.940 to 0.965 g / cc. All individual values and subranges of from 40 to 65 percent by weight are disclosed and included herein. For example, the polyethylene composition can comprise from 40, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, or 63 to 65, 63, 61, 59, 57, 55, 53, 51, 49, 47, 45, 43, or 41 percent by weight, based on total weight of the polyethylene composition, of the third polyethylene component.

[0117] The third polyethylene component can have a molecular weight (Mw) less than 100,000 g / mol, or less than 90,000 g / mol, or less than 80,000 g / mol, or from 15,000 to 90,000 g / mol. The third polyethylene component can have a density from 0.940 to 0.965 g / cc, or from 0.942 to 0.965 g / cc, or from 0.942 to 0.963 g / cc. The third polyethylene component can have various levels of C3-C12 a-olefin comonomer incorporation. In one embodiment, the third polyethylene component can have a lower C3-C12 a-olefin comonomer incorporation than the first polyethylene component. For example, the third polyethylene component can have less than 10 percent by weight of C3-C12 a-olefin comonomer, or from 0.5 to less than 10 percent by weight of C3-C12 a-olefin comonomer, or from 2 to less than 10 percent by weight of C3-C12 a- olefin comonomer. The one or more a-olefin comonomers of the third polyethylene component may be selected from the group consisting of propylene, 1-butene, 1-hexene, and 1-octene, orin the alternative, from the group consisting of 1-butene, 1-hexene and 1-octene, or in the alternative, from the group consisting of 1-hexene and 1-octene.

[0118] In an embodiment, the filament (or the tape) is composed of the polyethylene composition with (a) the first polyethylene component, (b) the second polyethylene component, and (c) the third polyethylene component, and the polyethylene composition has one, some, or all of the following properties:(i) a density of from 0.935 to 0.958 g / cc, or from 0.936 to 0.954 g / cc, or from 0.935 to 0.950 g / cc; and / or(ii) a melt index (L) of from 0.5 to 5.0 g / 10 min, or from 0.5 to 3.0 g / 10 min, or from 0.5 to 2.0 g / 10 min, or from 1.0 to 2.0 g / min; and / or(iii) a Mw / Mn from 3.5 to 10, or from 3.5 to 8.0. or from 3.5 to 6.0, or from 3.5 to 4.0; and / or(iv) a Mz / Mw from 3.0 to 5.5, or from 3.0 to 4.5, or from 3.0 to 3.9, or from 3.0 to 3.6; and / or(v) an I10 / I2 value from 8.5 to 15.0, or from 8.5 to 14.0, or from 8.5 to 13.0, or from 8.5 to 12.5; and the tape has one, some, or all of the following properties:(vi) a linear density from 300 dtex to 1500 dtex, or from 700 dtex to 1500 dtex or from725 dtex to 775 dtex; and / or(vii) a shrinkage value from 0.1% to less than 1.0% or from 0.1% to 0.5%; and / or(viii) an elongation from 20% to 30%; and / or(ix) a tenacity from 2.0 cN / dtex to 3.0 cN / dtex.

[0119] The filament, tape and / or the polyethylene composition may further include one or more optional additives. Nonlimiting examples of suitable additives include antioxidants, pigments, colorants, UV stabilizers, UV absorbers, curing agents, cross linking co-agents, boosters and retardants, processing aids, fillers, coupling agents, ultraviolet absorbers or stabilizers, antistatic agents, nucleating agents, slip agents, plasticizers, lubricants, viscosity control agents, tackifiers, anti-blocking agents, surfactants, extender oils, acid scavengers, andmetal deactivators. In an embodiment, colorant, such as SICOLEN™ green 85-125345 (available from BASF), may be added in an amount of less than about 10 wt. %, less than about 8 wt. %, less than about 6 wt. %, or even less than about 4 wt. %. In another embodiment, a processing aid, such as ARX-741 (available from Argus), may be added in an amount of less than about 2 wt. %, less than about 1.5 wt. %, or even less than about 1 wt. %. Additives can be used in amounts ranging from about 0.001 wt. % to more than about 10 wt. % based on the weight of the formulation.3. Artificial turf / backing layer

[0120] In an embodiment, the filament is a tape and is used as one more component in artificial turf. FIG. 1 shows an embodiment of an artificial turf 10 having a primary backing layer 13, with a plurality of artificial turf yarns 11 projecting upwardly therefrom. The term "artificial turf," as used herein, is a carpet-like cover having substantially upright, or upright, polymer strands of the artificial turf yarn 11 projecting upwardly from a substrate which is the primary backing layer 13. The artificial turf 10 may optionally include an infill 12 and a shock absorption layer 15. The artificial turf 10 also includes a secondary backing layer 14. The secondary backing layer 14 contacts the primary backing layer 13. As shown in FIG. 1, the artificial turf yarns 11, the primary backing layer 13, the secondary backing layer 14, and the shock absorption layer 15 may be attached to each other and the infill 12 can be spread on top of the artificial turf yarns 11. The artificial turf 10 can be disposed on the ground surface 16 or other desired surface.

[0121] The present artificial turf 10 includes a plurality of artificial turf yarns 11 projecting upwardly from the primary backing layer 13. The term "artificial turf yarn" or hereafter "yarn," as used herein, includes fibrillated tape yarn, co-extruded tape yarn, monotape yarn and monofilament yarn. A "fibrillated tape" or "fibrillated tape yarn," is a cast extruded film cut into tape (typically about 1 cm width), the film stretched, and long slits cut (fibrillated) into the tape giving the tape the dimensions of grass blades. A "monofilament yarn" is extruded into individual yarn or strands with a desired cross-sectional shape and thickness followed by yarn orientation and relaxation in hot ovens. The artificial turf yarn forms the polymer strands for the artificial turf. Artificial turf requires resilience (springback), toughness, flexibility,extensibility and durability. Consequently, artificial turf yarn excludes yarn for fabrics ( / .e., woven and / or knit fabrics).

[0122] The artificial turf yarn 11 is composed of a polymeric material. Nonlimiting examples of suitable polymeric material for the yarn include olefin-based polymer (such as propylene-based polymer and / or ethylene-based polymer), polyester, nylon, and combinations thereof. In an embodiment, the artificial turf yarn 11 is composed of an ethylene-based polymer. In a further embodiment, the artificial turf yarn 11 is composed of the present polyethylene composition with (a) the first polyethylene component, (b) the second polyethylene component, and (c) the third polyethylene component.

[0123] The artificial turf 10 may optionally include an infill 12. Nonlimiting examples of infill materials include mixtures of granulated rubber particles like SBR (styrene butadiene rubber) recycled from car tires, EPDM (ethylene / propylene / diene terpolymer), other vulcanized rubbers or rubber recycled from belts, thermoplastic elastomers (TPEs), thermoplastic vulcanizates (TPVs) and mixtures thereof.

[0121] The primary backing layer 13 is one or more sheets onto which the artificial turf yarn 11 is sewn or woven such that the artificial turf yarn 11 extends outwardly from the top side of the primary backing layer 13. The primary backing layer may be a polymeric sheet of woven fabric, a polymeric sheet of non-woven fabric, or a perforated polymeric sheet. The primary backing layer provides dimensional stability for the artificial turf system.

[0122] In an embodiment, the primary backing layer (interchangeably referred to as "backing layer") is composed of the present polyethylene composition as previously disclosed herein. The polyethylene composition includes (a) from 15 percent to 25 percent by weight of a first polyethylene component. The first polyethylene component has a molecular weight (Mw) greater than 200,000 g / mol and a density from 0.925 g / cc to 0.945 g / cc. The polyethylene composition includes (b) from 20 percent to 35 percent by weight of a second polyethylene component. The second polyethylene component has a molecular weight (Mw) less than 80,000 g / mol and a density from 0.915 g / cc to 0.950 g / cc. The polyethylene composition includes (c) from 40 percent to 65 percent by weight of a third polyethylene component. The third polyethylene component has a molecular weight (Mw) less than 100,000g / mol and a density from 0.940 g / cc to 0.965 g / cc. The polyethylene composition has a density of from 0.935 to 0.958 g / cc, and a melt index (12) of from 0.5 to 5.0 g / 10 min.

[0124] In an embodiment, the primary backing layer (or backing layer) is a woven fabric composed of warp filaments and weft filaments. The weft filaments are woven, or otherwise interlaced, through the warp filaments in an "over-under-over-under" manner as shown in FIG. 2 such that the weft filaments are at right angles to the warp filaments. At least one of the warp filaments or the weft filaments is composed of the present polyethylene composition.

[0125] In an embodiment, each of the warp filament and the weft filament is composed of the present polyethylene composition. In other words, the warp filament is composed of the present polyethylene composition and the weft filament is composed of the present polyethylene composition with (a) the first polyethylene component, (b) the second polyethylene component, and (c) the third polyethylene component.

[0126] In an embodiment, the warp filaments are warp tapes, and the weft filaments are weft tapes.

[0127] In an embodiment, the backing layer is a perforated sheet. The perforatedsheet is composed of the present polyethylene composition with (a) the first polyethylene component, (b) the second polyethylene component, and (c) the third polyethylene component.

[0128] The present disclosure is directed to trimodal polyethylene composition that can be used for filament / tape in the production of artificial turf backing layer. The present polyethylene composition provides desirable performance characteristics, such as low shrinkage, tenacity, and / or elongation for the primary backing layer. Without wishing to be bound by any particular theory, it is believed that the unique design of the present polyethylene composition— including, for example, the three component composition and desirable balance of a first polyethylene component weight fraction, Z average molecular weight (Mz), and an average short chain branch level in a portion between log(Mw) of 4.0 to 5.0 (SCB|OgMw4-s)— delivers improved processability, improved elongation, and reduced shrinkage characteristics for the tape. The inventive polyethylene composition can be incorporated into artificial turf, filament, tape, and / or artificial turf backing layer to enhance the recycle-ability of the artificial turf.

[0129] It is believed the HMW, near-homopolymer fraction, namely, the first polyethylene component (a), anchors the overall structure of the tape, so when the tape is exposed to higher temperatures, the LMW fractions (the second and third polyethylene components (b and c)) do not shrink as they are directly anchored by the first polyethylene component (a). In addition, the present polyethylene composition has an Ml from 0.5-5.0 g / 10 min and high lio / hfrom 8.5 to 15, which contribute to proper extruder processing.

[0130] By way of example, and not limitation, examples of the present disclosure will now be described in detail in the following examples.EXAMPLES . Materials

[0131] Materials for the inventive examples ("IE") and comparative samples ("CS") are listed in Tables 1A, IB, and 1C below.

[0132] Table 1A. Preparation of I El

[0133] All raw materials (monomer and comonomer) and the process solvent (a narrow boiling range high-purity isoparaffinic solvent, Isopar-E) are purified with molecular sieves before introduction into the reaction environment. Hydrogen is supplied pressurized as a highpurity grade and is not further purified. The reactor monomer feed stream is pressurized via a mechanical compressor to above reaction pressure. The solvent and comonomer feed is pressurized via a pump to above reaction pressure. The individual catalyst components are manually batch diluted with purified solvent and pressured to above reaction pressure. All reaction feed flows are measured with mass flow meters and independently controlled with computer automated valve control systems.

[0134] A two-reactor system is used in a series configuration. The first continuous solution polymerization reactor consists of a liquid full, non-adiabatic, isothermal, circulating, loop reactor which mimics a continuously stirred tank reactor (CSTR) with heat removal. Independent control of all fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds is possible. The total fresh feed stream to the first reactor (solvent, monomer, comonomer, and hydrogen) is temperature controlled to maintain a single solution phase by passing the feed stream through a heat exchanger. The total fresh feed to each polymerization reactor is injected into the reactor at three locations with approximately equal reactor volumes between each injection location. The fresh feed is controlled with each injector receiving one third of the total fresh feed mass flow. The catalyst components are injected into the polymerization reactor at two different locations with similar reactor volumes between each injection location and each injection receiving half of the total flow. The primary catalyst component feed is computer controlled to maintain the reactor monomer conversion at the specified target. The secondary catalyst component feed is set to a specified molar ratio to the total catalyst (Catalyst-B molar ratio = (Catalyst-B)mol / (Catalyst-A+Catalyst-B)mol * 100). The boron containing cocatalyst component is fed based on specified molar ratio to the total catalyst metal (primary + secondary) being fed to the reactor. The Al containing cocatalyst component is fed to maintain a specified concentration of Al in the reactor. Immediately following each reactor feed or catalyst injection location, the streams are mixed with the circulating polymerization reactor contents with static mixing elements. The contents of the reactor are continuously circulated through heat exchangers responsible for removing much of the heat of reaction and with the temperature of the coolant side responsible for maintaining an isothermal reaction environment at the specified temperature. Circulation around thereactor loop is provided by a pump. A sample system exists to periodically collect material from the first loop reactor. After collection, the sample is dried in a vacuum oven and submitted for GPC and iCCD analysis. The GPC and iCCD analysis provides a measurement of the polymer split between the primary catalyst and the secondary catalyst in the first reactor loop; the result of which can be used to adjust the secondary catalyst molar ratio to achieve the desired polymer split within the first reactor loop.

[0135] The effluent from the first polymerization reactor (containing solvent, monomer, comonomer, hydrogen, catalyst components, and polymer) exits the first reactor and is added to the second reactor.

[0136] The second continuous solution polymerization reactor consists of a liquid full, non- adiabatic, isothermal, circulating, loop reactor which mimics a continuously stirred tank reactor (CSTR) with heat removal. Independent control of all fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds is possible. The total fresh feed stream to the second reactor (solvent, monomer, comonomer, and hydrogen) is temperature controlled to maintain a single solution phase by passing the feed stream through a heat exchanger. The total fresh feed to each polymerization reactor is injected into the reactor at two locations with approximately equal reactor volumes between each injection location. The fresh feed is controlled with each injector receiving half of the total fresh feed mass flow. The catalyst components (Catalyst Component 3) are injected into the polymerization reactor through injection stingers. The primary catalyst component feed is computer controlled to maintain the reactor monomer conversion at the specified target. The cocatalyst component is fed based on a specified molar ratio to the primary catalyst component. Immediately following each reactor feed and catalyst injection location, the streams are mixed with the circulating polymerization reactor contents with static mixing elements. The contents of each reactor are continuously circulated through heat exchangers responsible for removing much of the heat of reaction and with the temperature of the coolant side responsible for maintaining an isothermal reaction environment at the specified temperature. Circulation around each reactor loop is provided by a pump.

[0137] Upon exiting the second reactor loop, the second / final reactor effluent enters a post-reactor adiabatic pipe, with a total volume approximately 21.4% that of the two loop reactors combined, where the reaction continues for a period prior to entering a mixing zone where the reaction is stopped by catalyst deactivation with the addition of and reaction with a suitable reagent (water). At this same reactor exit location other additives are added for polymer stabilization (typical antioxidants suitable for stabilization during extrusion and blown film fabrication like Octadecyl 3,5-Di-Tert-Butyl-4-Hydroxyhydrocinnamate, Tetrakis(Methylene(3,5-Di-Tert-Butyl-4-Hydroxyhydrocinnamate))Methane, and Tris(2,4-Di- Tert-Butyl-Phenyl) Phosphite) and acid neutralization (typical acid scavenger calcium stearate).

[0138] Following catalyst deactivation and additive addition, the reactor effluent enters a devolatization system where the polymer is removed from the non-polymer stream. The isolated polymer melt is pelletized and collected. The non-polymer stream passes through various pieces of equipment which separate most of the ethylene which is removed from the system. Most of the solvent and unreacted comonomer is recycled back to the reactor after passing through a purification system. A small amount of solvent and comonomer is purged from the process.

[0139] The reactor stream feed data flows that correspond to the values in Table IB used to produced the IE1 are graphically described in FIG. 3. The data are presented such that the complexity of the solvent recycle system is accounted for and the reaction system can be treated simply as a once through flow diagram.

[0140] The catalysts and cocatalysts used in the production of IE1 are provided in Table 1B below. The polymerization conditions for the production of IE1 are provided in Table 1C below.

[0141] Table IB - catalysts and cocatalysts for IE1

[0142] Table 1C -polymerization conditions for IE1

[0143] The density, melt index (I2), I10 / I2, Mz, Mw / Mn, Mz / Mn, and for IE1 and comparative samples PEI and PE2 are measured in accordance with the Test Methods section above. Tables 2 and Tables 3, 4, and 5 below provide the properties for IE1 and comparative samples PE2 and PE3.

[0144] Table 2 - Polyethylene Composition Data

[0145] The densities, Mw, and weight percent (wt.%) of each of the components (Comp.) (i.e., polyethylene component 1 (Comp. 1), polyethylene component 2 (Comp. 2), and polyethylene component 3 (Comp. 3)) are measured in accordance with the Test Methods section above. Table 3 provides the results.

[0146] Table 32. Preparation of tape

[0147] Tapes are produced in a fibrillated tape line. The process starts with the extrusion of a cast film of the present polyethylene composition which is immediately immersed in a water bath for quenching. The cast film is then removed from the water bath and drying of the film is conducted to avoid any moisture or water on it. Then, the film is fibrillated into smaller films. Depending on the type of tape to be extruded the width is different (2mm width for warp and 5 mm width for weft).

[0148] After the fibrillation, a stretching step is then conducted. The film is stretched in an oven (105°C-115°C) at a stretching ratio from 4-5. The term "stretching ratio," (or "SR") is defined as the ratio of stretching of the film between the entrance at the oven and the exit ofthe oven. It is measured a ratio of the line speed at the oven entrance divided by the line speed at the oven exit.

[0149] An annealing step is performed after the stretching step. In the annealing step, the filaments are heated in an oven (105 °C-115°C) and / or rolled under a controlled speed to control shrink.

[0150] Finally, a fibrillation in each of the tapes is conducted. For primary backing layer, a pin fibrillation is conducted, which objective is to create small cuts in the film which will help on the tufting of the yarns afterwards.

[0151] Warp tapes have a 1 mm width, and two tapes are wrapped together to form a single warp tape. Weft tapes have a 2.2-2.3 mm width, and they are used individually.

[0152] The stretching ratio and annealing remained constant for all the samples, which is 5.2 SR and 10% annealing. The process conditions for tape production are provided in Table 4 below.

[0153] Table 4. Processing conditions for tape production.

[0154] The comparative samples (PEI, PE2) and the inventive example (IE1) were run at750 dtex. The properties of the tapes are provided in Table 5 below.

[0155] Table 5. Mechanical properties of tapes produced.

[0156] CS1 and IE1 are directly comparable; both resins have the same density (0.950 g / cc) and the same Ml (1.5-1.6 g / lOmin). CS1 has a shrinkage of 1.6%, whereas IE1 has a shrinkageof 0.4%. The tri-modality of the present polyethylene composition in I El provides a 4x improvement in shrinkage (i.e., less shrinkage) compared to CS1.

[0157] CS2 has a greater density (0.955 g / cc) compared to IE1 (0.950 g / cc). However, IE1 still achieves lower shrinkage (0.4%) compared to the shrinkage of CS2 (1.1%).

[0158] Typically, shrinkage is linked to the density of the resin, and all things being equal, a polyethylene resin with a higher density will typically have a shrinkage that is lower than a polyethylene resin with a lower density. CS2 has a higher density than CS1 and IE1 (CS2 density 0.955 g / cc v CS1 / IE1 density 0.950 g / cc). CS2 displays a shrinkage of 1.1%. Applicant unexpectedly discovered a polyethylene resin that achieves low shrinkage (0.4%) in the tape. Bounded by no particular theory, it is believed the low shrinkage in the IE1 tape is due to the molecular structure of the trimodal polyethylene resin of IE1. The ability of Applicants IE1 polyethylene composition to achieve lower shrinkage (0.4%) at density 0.950g / cc compared to the 1.1% shrinkage of CS1 polyethylene resin with the same density (0.950 g / cc) and I El's ability to achieve lower shrinkage (0.4%) at lower density (0.950 g / cc) compared to CS2's 1.1% shrinkage at higher density (0.955 g / cc) is unexpected.

[0159] It is specifically intended that the present disclosure not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.

Claims

CLAIMS1. A filament comprising: a polyethylene composition comprising(a) from 15 to 25 percent by weight of a first polyethylene component having a molecular weight (Mw) greater than 200,000 g / mol and a density from 0.925 g / cc to 0.945 g / cc;(b) from 20 to 35 percent by weight of a second polyethylene component having a molecular weight (Mw) less than 80,000 g / mol and a density from 0.915 g / cc to 0.950 g / cc; and(c) from 40 to 65 percent by weight of a third polyethylene component having a molecular weight (Mw) less than 100,000 g / mol and a density from 0.940 g / cc to 0.965 g / cc; and the polyethylene composition has a density from 0.935 g / cc to 0.958 g / cc, and a melt index ( I2) from 0.5 g / 10 min to 5.0 g / 10 min.

2. The filament of claim 1, wherein the polyethylene composition has a Mz / Mw from 3.0 to 5.5.

3. The filament of any of claims 1-2, wherein the polyethylene composition has a molecular weight distribution (Mw / Mn) from 3.5 to 10.

4. The filament of any of claims 1-3 wherein the polyethylene composition has a melt index 110 / melt index 12 (110 / 12) value from 8.5 to 15.

5. The filament of any of claims 1-4 wherein the filament has a linear density from 300 dtex to 1500 dtex.

6. The filament of any claims 1-5 wherein the filament has a shrinkage value from 0.1% to less than 1.0%.

7. The filament of any of claims 1-6 wherein the filament has an elongation from 20% to 30%.

8. The filament of any of claims 1-7 wherein the filament has a tenacity from 2.0 cN / dtex to 3.0 cN / dtex.

9. The filament of any of claims 1-8 wherein the filament is a tape.

10. A backing layer comprising: a polyethylene composition comprising(a) from 15 to 25 percent by weight of a first polyethylene component having a molecular weight (Mw) greater than 200,000 g / mol and a density from 0.925 to 0.945 g / cc;(b) from 20 to 35 percent by weight of a second polyethylene component having a molecular weight (Mw) less than 80,000 g / mol and a density from 0.915 to 0.950 g / cc; and(c ) from 40 to 65 percent by weight of a third polyethylene component having a molecular weight (Mw) less than 100,000 g / mol and a density from 0.940 to 0.965 g / cc; and the polyethylene composition has a density from 0.935 g / cc to 0.958 g / cc, and a melt index ( I2) from 0.5 g / 10 min to 5.0 g / 10 min.

11. The backing layer of claim 10 wherein the backing layer is a ground fabric comprising one or more warp filaments; and one or more weft filaments woven through the warp filaments; and at least one of the warp filaments and the weft filaments is composed of the polyethylene composition.

12. The backing layer of claim 11 wherein the warp filaments are composed of the polyethylene composition; and the weft filaments are composed of the polyethylene composition.

13. The backing layer of claim 12 wherein the warp filaments are warp tapes; and the weft filaments are weft tapes.

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