EP4655349A1

EP4655349A1 - Polyethylene composition for insulation layer

Info

Publication number: EP4655349A1
Application number: EP24713029.7A
Authority: EP
Inventors: Michael T. PETR; Paul J. Brigandi; Mohamed Esseghir; Doug S. GINGER; Andrew T. Heitsch
Original assignee: Dow Global Technologies LLC
Current assignee: Dow Global Technologies LLC
Priority date: 2023-02-20
Filing date: 2024-02-05
Publication date: 2025-12-03
Also published as: JP2026507521A; CN120659841A; KR20250150613A; MX2025009427A; WO2024177801A1

Abstract

The present disclosure is directed to a composition. In an embodiment, the composition includes (A) a base bimodal ethylene/C₄-C₈ α-olefin copolymer. The base bimodal ethylene/C₄- C₈ α-olefin copolymer has (i) a density from 0.91 g/cc to 0.93 g/cc, (ii) an I₂₁/l₂ from 90 to 140, (iii) a Mw/Mn from 7.0 to 15.0, (iv) an Mz less than 600,000 g/mol, (v) an SHI (η0.1/η100) value from 5.0 to 30.0, (vi) from 0 ppb to 80 ppb boron, and (vii) from 0 ppm to 5 ppm of fluorine. The composition is suitable as an insulation layer on a cable.

Description

POLYETHYLENE COMPOSITION FOR INSULATION LAYER

BACKGROUND

[0001] Linear low density polyethylene (LLDPE) finds widespread application as a base resin for cable jacketing for telecommunication and power cables because of several favorable features. LLDPE has a low dielectric constant, which provides good electrical insulation between conducting elements. LLDPE provides adequate toughness for these applications and can be compounded with additives, such as carbon black for UV stability. It also can formulated as a semiconductive compound. LLDPE is readily crosslinkable which provides thermal stability over a wide temperature range beyond its thermoplastic state.

[0002] One drawback to LLDPE is that it typically has a narrow molecular weight distribution (MWD) with a polydispersity less than 5.0 because it is metallocene catalyzed in a single reactor. This narrow MWD leads to a high degree of shear flow deformation when LLDPE is extruded through an annular die at high shear rate, as occurs in the production of the jacket layer of a wire or cable. The high degree of shear flow deformation leads to surface roughness for the cable jacket when LLDPE is extruded onto cable at a high rate. Surface roughness for cable jacket leads to reduced electrical performance because the surface roughness concentrates the electric fields in the cable jacket.

[0003] Chromium catalyzed olefin polymerization is known to produce LLDPE with broad MWD, which is characterized by a high melt flow ratio, and in particular, an I21/I2 value of 80 or greater. On the other hand, the catalysts and the activators typically used in solution phase polymerization systems (/.e., non-chromium catalyst based) produce LLDPE with narrow molecular weight distribution (polydispersity less than 5.0), which results in a rough surface during extrusion and may lead to electrical stress concentration and interfacial issues when the cable is jacketed. Moreover, in wire and/or cable-coating applications, a smooth surface is necessary for the LLDPE cable jacket to maximize electrical performance and to provide an aesthetically-acceptable consumer end-product. Thus, the art recognizes the need for polyethylene compositions, and LLDPE compositions in particular, with broad MWD and high shear thinning (/.e., I21/I2 ratio greater than 80) for good processability at high extrusion shear rates to form a smooth cable jacket for wire and/or cable coatings, while simultaneously providing a mechanically tough coating layer for cable protection.

SUMMARY

[004] The present disclosure is directed to a composition. In an embodiment, the composition includes (A) a base bimodal ethylene/C4-C8 α-olefin copolymer. The base bimodal ethylene/C4- C8 α-olefin copolymer has (i) a density from 0.91 g/cc to 0.93 g/cc, (ii) an I21/12 from 90 to 140, (iii) a Mw/Mn from 7.0 to 15.0, (iv) an Mz less than 600,000 g/mol, (v) an SHI (η0.1/η100) value from 5.0 to 30.0, (vi) from 0 ppb to 80 ppb boron, and (vii) from 0 ppm to 5 ppm of fluorine.

[005] The present disclosure is directed to a cable. In an embodiment, the cable includes a conductor and a cable jacket on the conductor. The cable jacket is composed of a composition composed of (A) a base bimodal ethylene/C4-C8 α-olefin copolymer, the base bimodal ethylene/C4-C8 α-olefin copolymer having (i) a density from 0.91 g/cc to 0.93 g/cc, (ii) an I21/I2 from 90 to 140, (iii) a Mw/Mn from 7.0 to 15.0, (iv) an Mz less to 600,000 g/mol, (v) an SHI (η0.1/η100) value from 5.0 to 30.0, (vi) from 0 ppb to 80 ppb boron, (vii) from 0 ppm to 5 ppm of fluorine. The cable jacket has a surface roughness Ra value from 5.0 p-in to 25.0 p-in.

BRIEF DESCRIPTION OF THE DRAWINGS

[006] FIG. 1 is a chart showing the chemical structures for different types of carbon- carbon double bonds (unsaturation in polymer chain) for vinylene, trisubstituted, vinyl, and vinylidene.

[007] FIG. 2 is a schematic representation of the flow pattern for a two reactor polymerization system in accordance with an embodiment of the present disclosure.

DEFINITIONS

[008] 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.

[009] 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 U.S. 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). [0010] The numerical ranges disclosed herein include all values from, and including, the lower and upper value. For ranges containing explicit values (e.g., 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 of from 1 to 2; from 2 to 6; from 5 to 7; from 3 to 7; from 5 to 6; etc.).

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

[0012] A "bimodal" polyethylene composition contains two polyethylene fractions that have been produced under different polymerization conditions, including differences in any of the process conditions and/or catalyst systems, resulting in different molecular weights and/or different comonomer contents for the fractions. The first polyethylene fraction is a high molecular weight component. The second polyethylene fraction is a low molecular weight component. The bimodal polyethylene is an in-reactor blend of the high molecular weight component and the low molecular weight component whereby one component is produced and then is present in the production of the second component.

[0013] The terms "blend" or "polymer blend," as used, refers to a mixture of two or more polymers. A blend may or may not be miscible (not phase separated at molecular level). A blend may or may not be phase separated. A blend may or may not contain one or more domain configurations, as determined from transmission electron spectroscopy, light scattering, x-ray scattering, and other methods known in the art. The blend may be affected by physically mixing the two or more polymers on the macro level (for example, melt blending resins or compounding), or the micro level (for example, simultaneous forming within the same reactor). [0014] The term "composition" refers to a mixture of materials which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0015] The terms "comprising," "including," "having" and their derivatives, are not intended to exclude the presence of any additional component, step or procedure, whether or not the same is specifically disclosed. In order to avoid any doubt, all compositions claimed through use of the term "comprising" may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term "consisting essentially of" excludes from the scope of any succeeding recitation any other component, step, or procedure, excepting those that are not essential to operability. The term "consisting of" excludes any component, step, or procedure not specifically delineated or listed. The term "or," unless stated otherwise, refers to the listed members individually as well as in any combination.

[0016] An "ethylene-based polymer" is a polymer that contains more than 50 mole percent (wt%) polymerized ethylene monomer (based on the total amount of polymerizable monomers) and, optionally, may contain at least one comonomer. Ethylene-based polymer includes ethylene homopolymer, and ethylene copolymer (meaning units derived from ethylene and one or more comonomers). The terms "ethylene-based polymer" and "polyethylene" may be used interchangeably. Ethylene-based polymer may include ethylene copolymerized with an α-olefin (e.g., C3-C12 α-olefin, or C4-C8 α-olefin).

[0017] The term "ethylene monomer," or "ethylene," as used herein, refers to a chemical unit having two carbon atoms with a double bond there between, and each carbon bonded to two hydrogen atoms, wherein the chemical unit polymerizes with other such chemical units to form an ethylene-based polymer composition.

[0018] A "heteroatom" is an atom other than carbon or hydrogen. The heteroatom can be a non- carbon atom from Groups IV, V, VI and VII of the Periodic Table. Nonlimiting examples of heteroatoms include: F, N, O, P, B, S, and Si.

[0019] A "hydrocarbon" is a compound containing only hydrogen atoms and carbon atoms. A hydrocarbon can have a linear structure, a cyclic structure, or a branched structure.

[0020] "Linear low-density polyethylene" (or "LLDPE") is a linear ethylene/α-olefin copolymer containing heterogeneous short-chain branching distribution comprising units derived from ethylene and units derived from at least one C3-C10 α-olefin comonomer or at least one C₄-C₈ α- olefin comonomer, or at least one C6-C8 α-olefin comonomer. LLDPE is characterized by little, if any, long chain branching, in contrast to conventional LDPE. LLDPE has a density from 0.910 g/cc to 0.940 g/cc, or from 0.910 g/cc to 0.930 g/cc, or from 0.915 g/cc to 0.930 g/cc, or from 0.915 g/cc to 0.925 g/cc.

[0021] "Low density polyethylene" (or "LDPE") consists of ethylene homopolymer, or ethylene copolymer with acrylate, vinyl acetate, and/or vinyl silane as comonomer, the LDPE has a density from 0.915 g/cc to 0.940 g/cc and contains long chain branching with broad molecular weight distribution (MWD). LDPE is typically produced by way of high pressure free radical polymerization (tubular reactor or autoclave with free radical initiator). Nonlimiting examples of LDPE include LDPE products from Chevron Phillips (MarFlex™), LyondellBasell (LUPOLEN™), Borealis, Ineos, ExxonMobil, and others.

[0022] An "olefin" is an unsaturated, aliphatic hydrocarbon having a carbon-carbon double bond.

[0023] An "olefin-based polymer" (interchangeably referred to as "polyolefin") is a polymer that contains a majority weight percent of polymerized olefin monomer (based on the total amount of polymerizable monomers), and optionally, may contain at least one comonomer. Nonlimiting examples of olefin-based polymer include ethylene-based polymer and propylene-based polymer.

[0024] The term "polymer" or a "polymeric material," as used herein, refers to a compound prepared by polymerizing monomers, whether of the same or a different type, that in polymerized form provide the multiple and/or repeating "units" or "mer units" that make up a polymer. The generic term polymer thus embraces the term homopolymer, usually employed to refer to polymers prepared from only one type of monomer, and the term copolymer, usually employed to refer to polymers prepared from at least two types of monomers. It also embraces all forms of copolymer, e.g., random, block, etc. The terms "ethylene/α-olefin polymer" and "propylene/α-olefin polymer" are indicative of copolymer as described above prepared from polymerizing ethylene or propylene respectively and one or more additional, polymerizable α-olefin monomer. It is noted that although a polymer is often referred to as being "made of" one or more specified monomers, "based on" a specified monomer or monomer type, "containing" a specified monomer content, or the like, in this context the term "monomer" is understood to be referring to the polymerized remnant of the specified monomer and not to the unpolymerized species. In general, polymers herein are referred to as being based on "units" that are the polymerized form of a corresponding monomer.

[0025] A "sheath" when used in relation to cables includes insulation coverings or layers, protective jackets and the like.

[0026] A "wire" is a single strand of conductive metal, e.g., copper or aluminum, or a single strand of optical fiber. TEST METHODS

[0027] ¹³C NMR. ¹³C nuclear magnetic resonance (¹³C NMR) is used to determine the type and amount of short chain branching, i.e., comonomer, in the polymer. Samples for ¹³C NMR were prepared by adding approximately 3g of 1,1,2,2-tetrachloroethane (TCE) containing 25 wt% TCE- d2 and 0.025 M Cr(AcAc)3, to about 0.10 g polymer sample, in a 10 mm NMR tube. The samples were dissolved and homogenized by heating the tube and its contents to 135°C using a heating block and vortex mixer. Each dissolved sample was visually inspected to ensure homogeneity. Samples were thoroughly mixed immediately prior to analysis and were not allowed to cool before insertion into the heated NMR sample holders. All data were collected using a Bruker 600 MHz spectrometer equipped with a 10 mm high temperature cryoprobe. The ¹³C data was acquired using a 7.8 second pulse repetition delay, 90-degree flip angles, and inverse gated decoupling, with a sample temperature of 120°C. All measurements were made on non-spinning samples in locked mode. Samples were allowed to thermally equilibrate prior to data acquisition. The ¹³C NMR chemical shifts were internally referenced to the EEE triad at 30.0 ppm. Composition was determined using the assignments from Liu, W.; Rinaldi, P. L.; McIntosh, L. H.; and Quirk, R. P.; Macromolecules, 34, 2001, 4757-4767 (for ethylene-co-octene polymer), and Sahoo, S. K., et al., Macromolecules 36, 2003, 4017-4028 (for ethylene-co-butene polymer) and integrated ¹³C NMR spectra to solve the vector equation s=fM where M is an assignment matrix, s is a row vector representation of the spectrum, and f is a mole fraction composition vector. The elements of f were taken to be triads of E and O (octene) or B (butene) with all permutations of E and O or B. The assignment matrix M was created with one row for each triad in f and a column for each of the integrated NMR signals. The elements of the matrix were integral values determined by reference to the assignments in (Liu, W.; Rinaldi, P. L.; McIntosh, L. H.; and Quirk, R. P.; Macromolecules, 34, 2001, 4757-4767), or Sahoo, S. K., et al., Macromolecules 36, 2003, 4017-4028. The equation was solved by variation of the elements of f as needed to minimize the error function between s and the integrated ¹³C data for each sample. This is executed in Microsoft Excel by using the Solver function.

[0028] ¹H NMR. ¹H nuclear magnetic resonance pH NMR) was used to quantitate the following types of carbon-carbon double bonds ("unsaturations") in the polymer. "Vinylene" is a carbon- carbon double bond with the formula Ri- CH= CH - R2, wherein Ri and R2 are each one or more carbon atoms with attached hydrogen atoms. "Trisubstituted" is a carbon-carbon double bond in which the doubly bonded carbons are bonded to a total of three carbon atoms and wherein R1, R2 and R3 (in FIG. 1) each is a carbon atom. "Vinyl" is a carbon-carbon double bond with the formula R- CH= CH2, wherein R is a carbon atom. "Vinylidene" is a carbon-carbon double bond with the formula RI(R2)C=CH2 where-in Ri and R2 are each one or more carbon atoms with attached hydrogen atoms. "Total unsaturation (or "total") is the sum of vinylene, trisubstituted, vinyl, and vinylidene in a polymer. The chemical structures for vinylene, trisubstituted, vinyl, and vinylidene are provided in FIG.l. Samples for ¹H NMR were prepared by adding approximately 3g of a 50/50 mixture of 1,1,2,2-tetrachloroethane (TCE-d2) and perchloroethylene (PCE) containing 0.001 M Cr(AcAc)3, to about 0.10 g polymer sample, in a 10 mm NMR tube. The ¹H NMR was performed on a Bruker 600 MHz spectrometer equipped with a 10mm high temperature cryoprobe and a sample temperature of 120°C. Two experiments were run to obtain spectra, a control spectrum to quantitate the total polymer protons, and a double presaturation experiment, which suppresses the intense polymer backbone peaks and enables high sensitivity spectra for quantitation of the end-groups. The control was run with ZG pulse, 16 scans, AQ 1.64s, DI 14s. The double presaturation experiment was run with a modified pulse sequence, 64 scans, AQ 1.64s, presaturation delay 2s, relaxation delay 12s.

[0029] Density was measured in accordance with ASTM D792, Method B. The result is recorded in grams per cubic centimeter (g/cc).

[0030] Dynamic Mechanical Spectroscopy (DMS). DMS is used to measure polymer melt viscosity. Resins were compression-molded into "3 mm thick x 1 inch" circular plaques at 350 °F, for five minutes, under 25000 psi pressure, in air. The sample was then taken out of the press and placed on a counter to cool. A constant temperature frequency sweep was performed using a TA Instruments "Advanced Rheometric Expansion System (ARES)," equipped with 25 mm (diameter) parallel plates, under a nitrogen purge. The sample was placed on the plate, and allowed to melt for five minutes at 190 °C. The plates were then closed to a gap of "2 mm," the sample trimmed (extra sample that extends beyond the circumference of the "25 mm diameter" plate was removed), and then the test was started. The method had an additional five minute delay built in, to allow for temperature equilibrium. The experiments were performed at 190 °C over a frequency range of 0.1 to 100 (radians/second). The strain amplitude was constant at 10%. The complex viscosity η*, tan (6) or tan delta, viscosity at 0.1 radians/second (V0.1), the viscosity at 100 rad/s (V100), and the viscosity ratio (V0.1/V100) were calculated from these data.

[0031] Environmental stress crack resistance (ESCR) FO and F50 in hours are measured according to ASTM D1693 using condition A or condition B, in a solution containing either 10% IGEPAL CO-630 or 100% IGEPAL CO-630. ESCR FO is the number of hours until the first sample cracks. ESCR F50 is the number of hours until half the samples have cracked. IGEPAL CO-630 is nonylphenoxy poly(ethyleneoxy) ethanol.

[0032] Elemental analysis. Boron elemental analysis was determined using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). The samples were prepared for ICP metals analysis, in duplicate, by weighing 0.25 grams (nominal) into 15-mL Teflon test tubes and adding 1-mi lliliter (mL) of de-ionized water, 2-mL of concentrated nitric acid and 0.15 mL hydrofluoric acid. The tubes were then placed into a Milestone Ultrawave closed vessel microwave digestion system and digested at 240°C for 30 minutes. After digestion, the samples were removed from the microwave and diluted to a final volume of ten milliliters using de-ionized water. The samples were transferred into autosampler test tubes and were ready for ICP-MS analysis.

[0033] The prepared solutions were analyzed using inductively coupled plasma mass spectroscopy (ICP-MS) using an Agilent 7900x. The instrument was calibrated over the range of 0-10 ng/mL using 0, 0.5, 1.0, 5.0 and 10 ng/mL calibration standards (SPEX CertiPrep, Multi- element Standards) made up in 5% nitric acid and 1.5% hydrofluoric acid. The instrument operating conditions used for this analysis are shown in Table A. Where possible, multiple isotopes of the analytes were monitored in no gas, hydrogen, and helium mode. This was done in case there may have been any interferences from the sample matrix. Table A. Agilent 7900x ICP-MS Instrument Operating Conditions.

[0034] All other elements were determined using Neutron Activation Analysis ("NAA). Duplicate samples were prepared by transferring approximately 3.5 grams of the resins into pre- cleaned 2-dram polyethylene vials. Duplicate fluorine standards were prepared from a NIST fluoro-benzoic acid standard into similar vials. The fluorine standards were diluted to 6ml with 2-propanol and heat sealed. Similarly, Mg, Al, Ti, Hf, Cr and Zr standards were prepared from their standard solutions (Certi. pure from SPEX) into 2-dram polyethylene vials. They were diluted using milli-Q. pure water to 6ml and the vials were heat-sealed. The samples and standards were then analyzed following the standard NAA procedure, Global-SOP-01101.02 for these elements, using the Dow Mark I TRIGA nuclear reactor. For Mg, Al, Ti, Hf, Cr and Zr analysis, the samples were transferred to un-irradiated vials before doing the gamma-spectroscopy. For the fluorine, background contributions were addressed by using clean vials and making multiple runs with different vials. The reactions and experimental conditions used for the elements are summarized in Table B. The elemental concentrations were calculated using Canberra™ software and standard comparative technique.

Table B. Reactions and experimental conditions used for some of the elements during the NAA

[0035] Gel permeation chromatography. The average molecular weights and molecular weight distributions for ethylene-base polymers are determined with gel permeation chromatography (GPC). The chromatographic system consisted of a PolymerChar GPC-IR (Valencia, Spain) high temperature GPC chromatograph equipped with an internal IR5 infrα-red detector (IR5) and 4- capillary viscometer (DV) coupled to a Precision Detectors (Now Agilent Technologies) 2-angle laser light scattering (LS) detector Model 2040. For all absolute Light scattering measurements, the 15 degree angle is used for measurement. The autosampler oven compartment was set at 160^° Celsius and the column and detector compartment were 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.

[0036] 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 polystyrene standards 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)).: where M is the molecular weight, A has a value of 0.43 and B is equal to 1.0.

[0037] A fifth order polynomial was used to fit the respective polyethylene-equivalent calibration points.

[0038] 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.

[0039] 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.

[0040] The calculations of Mn(GPc), MW(GPQ, 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) from Equation 1.

[0041] In order to monitor the deviations overtime, 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.

Flowrate(effective) = Flowrate(nominal) * (RV(FM Calibrated) / RV(FM Sample)) (EQ5)

[0042] Melt Index. The term "melt index," or "Ml" as used herein, refers to the measure of how easily a thermoplastic polymer flows when in a melted state. Melt index, or "I2," is measured in accordance by ASTM D 1238 Method A, Condition 190 °C/2.16 kg, and is reported in grams eluted per 10 minutes (g/10 min). The "I21" value is measured in accordance with ASTM D 1238 Method A, Condition 190°C/21.6 kg, and is reported in grams eluted per 10 minutes (g/10 min). A melt flow rate ratio, "I21/I2," is calculated from these individual values by dividing the I21 value by the I2 value. The melt flow rate ratio is dimensionless. The I21/I2 ratio is an indirect measure of the viscosity ratio at high shear rate and low shear rates and is indicative of shear thinning behavior which is related to both molecular weight distribution (Mw/Mn) as well as the presence of long chain branching, each of which significantly affect processability. In general, polyethylene containing long chain branching possesses high melt strength and exhibits low viscosity under high shear rate conditions, permitting high processing rates compared to polyethylene with little, or no, long chain branching.

[0043] Shear thinning index (SHI) was calculated as the ratio of the dynamic viscosity measured at 0.1 rad/s to that at 100 rad/s and 190°C.

[0044] Surface roughness. Cable jacket surface roughness was evaluated by the average surface roughness, Ra, as measured using a Mitutoyo Surftest SJ-400 surface roughness tester. Results are reported in micro-inches or p-in.

[0045] Tensile properties. The present cable jacket can be characterized by its tensile strength at break (in megapascals, MPa) and elongation at break (%). Break stress and elongation at break are measured in accordance with the ASTM D638 testing procedure on compression molded samples prepared according to ASTM D4703. Elongation at break ("TE"), or elongation to break, is the strain on a sample when it breaks, expressed as a percent. Aged break stress strength and aged elongation at break each are measured after a sample is held at a temperature of 121°C for 7 days with results in pounds per square inch (psi).

DETAILED DESCRIPTION

[0046] The present disclosure provides a composition. In an embodiment, the composition includes a base bimodal ethylene/C4-C8 α-olefin copolymer. The base bimodal ethylene/C4-C8 α- olefin copolymer has one, some, or all of the following properties: (i) a density from 0.910 g/cc to 0.930 g/cc, (ii) an I21/I2 ratio from 90 to 140, (iii) an Mw/Mn from 7.0 to 15.0, (iv) an Mz less than 600,000 g/mol, and (v) an SHI (η0.1/η100) value from 5.0 to 30.0. The base bimodal ethylene/C4-C8 α-olefin copolymer also includes (vi) from 0 ppb to 80 ppb boron, and (vii) from 0 ppm to 5ppm fluorine.

1. Bimodal Ethylene/C4-C8 α-olefin copolymer

[0047] The present composition includes a base bimodal ethylene/C4-C8 α-olefin copolymer. The "base bimodal ethylene/C4-C8 α-olefin copolymer," as used herein, refers to the ethylene/C4-C8 α- olefin copolymer prior to the ethylene/C4-C8 α-olefin copolymer being blended with, or otherwise combined with, the carbon black masterbatch.

[0048] The base ethylene/α-olefin copolymer is a bimodal ethylene/α-olefin copolymer. The α- olefin is a C3-C20 comonomer, or C4-C8 comonomer. Nonlimiting examples of suitable α-olefin comonomer include butene, hexene, and octene. A "bimodal ethylene/α-olefin copolymer" is an ethylene/C4-C8 α-olefin copolymer that has two distinct populations, which often exhibit two peaks on a GPC curve. These distributions are viewed statistically, that is, as statistical distributions. Thus where there is one peak, the distribution has one mode and is unimodal. Two peaks are bimodal. Two or more peaks are multimodal. In an embodiment, the bimodal ethylene/C4-C8 α-olefin copolymer has a high molecular weight portion and a low molecular weight portion thereby defining "a bimodal molecular weight distribution." The "high molecular weight portion" of the bimodal ethylene/α-olefin copolymer has a Mw from 100,000g/mol to l,000,000g/mol, the "low molecular weight portion" of the bimodal ethylene/α-olefin copolymer has a Mw from l,000g/mol to less than 100,000 g/mol. The bimodal ethylene/α-olefin copolymer has a Mw/Mn from 7.0 to 15.0, or from 7.0 to 13.0, or from 7.1 to 12.0. In an embodiment, the bimodal ethylene/C₄-C8 α-olefin is an ethylene/octene copolymer.

[0049] In an embodiment, the base bimodal ethylene/C₄-C8 α-olefin copolymer is produced in a solution polymerization process. A "solution polymerization process," refers to one or more continuous solution polymerization reactors, operating under polymerization conditions, wherein the polymer (e.g., polyethylene) is formed in a liquid polymerization solvent to which monomer (e.g., ethylene) and comonomers (e.g., C3-C20 α-olefin, or C4-C8 α-olefin) along with catalyst/cocatalyst (activator) are added. The term "polymerization conditions," as used herein, refer to process parameters under which ethylene and comonomer are copolymerized in the presence of a catalyst system. Polymerization conditions include, for example, polymerization reactor conditions (reactor type), reactor pressure, reactor temperature, concentrations of reagents and polymer, solvent, carrier, residence time and distribution, influencing the molecular weight distribution and polymer structure.

[0050] In an embodiment, the base bimodal ethylene/α-olefin copolymer is produced in a two- reactor solution polymerization system whereby the effluent from a first solution polymerization reactor flows into a second solution polymerization reactor. A first catalyst and cocatalyst (or first activator) are injected into the first solution polymerization reactor and a second catalyst and cocatalyst (or second activator) are injected into the second solution polymerization reactor. The first catalyst and the second catalyst each is void of, or otherwise excludes chromium. The first cocatalyst and the second cocatalyst each is void of, or otherwise exclude boron and fluorine. [0051] In an embodiment, a two-reactor solution polymerization system is used to produce the base bimodal ethylene/α-olefin copolymer as an ethylene/C4-C8 α-olefin copolymer, or ethylene/octene copolymer having one, some, or all of the following properties:

(i) a density from 0.910 g/cc to 0.930 g/cc, or from 0.915 to 0.925 g/cc; and/or

(ii) an I 21/I2 ratio from 90 to 140, or from 92 to 135, or from 93 to 130; and/or

(iii) an Mw/Mn from 7.0 to 15.0, or from 7.0 to 13.0, or from 7.1 to 12.0; and/or

(iv) an Mz less than 600,000 g/mol, or from 100,000 g/mol to 500,000 g/mol, or from 200,000 g/mol to 400,000 g/mol, or from 300,000 g/mol to 400,000 g/mol; and/or

(v) an SHI value (r)0.1/r)100) from 5.0 to 30.0, or from 7.0 to 28, or from 8.0 to 27, or from 9.0 to 23.0; and/or

(vi) 0 parts per billion (ppb), or from greater than 0 ppb to 80 ppb, or from 1 ppb to 50 ppb boron;

(vii) 0 parts per million (ppm), or from greater than 0 ppm to 5 ppm, or from 1 ppm to 3 ppm fluorine; and/or

(viii) 0 ppb, or from greater than 0 ppb to less than 100 ppb chromium; and/or

(ix) an I2 value from 0.6 g/10 min to 1.2 g/10 min, or from 0.7 g/10 min to 1.1 g/10 min (hereafter compositionl). In an embodiment, compositionl, when shaped as 75 mil tensile bar, has:

(1) an aged break stress from 2100 psi to 2900 psi, and/or

(2) an aged elongation at break from 500% to 700%, or from 525% to 680%.

2. Carbon black

[0052] In an embodiment, the composition includes carbon black. The carbon black may or may not be a component of a carbon black masterbatch. When present, the carbon black masterbatch is composed of carbon black and a polyethylene carrier. Suitable polyethylene carriers include LDPE, LLDPE and combinations thereof. A nonlimiting example of a suitable carbon black masterbatch is AXELERON™ GP A-0037 BK CPD, which contains Carbon Black P-Type or Carbon C, in LLDPE carrier.

[0053] In an embodiment, the composition contains from 3.0 wt% to 10.0 wt%, or from 4.0 wt% to 8.0 wt%, or from 5.0 wt% to 7.0 wt%, or 5.78 wt% of the carbon black masterbatch, based on total weight of the polyethylene composition and/or from 1.3 wt% to 4.5 wt%, or from 1.8 wt% to 3.6 wt%, orfrom 2.25 wt%to 3.15 wt%, or 2.6 wt% carbon black, based on the total weight of the polyethylene composition.

[0054] In an embodiment, carbon black masterbatch is melt blended with the base bimodal ethylene/C4-C8 α-olefin copolymer. Melt blending can be performed with batch melt blending (by way of a Banbury mixer, for example), or can be performed with continuous melt blending (by way of an extruder, for example).

[0055] In an embodiment, the composition includes

(A) from 90 wt % to 97 wt%, or from 92 wt% to 96 wt%, or from 93 wt% to 95 wt% of a base bimodal ethylene/C₄-C₈ α-olefin copolymer, the base bimodal ethylene/C₄-C₈ α-olefin copolymer prior to blending with the carbon black, having one, some, or all of the following properties:

(v) an SHI value (r|0.1/r|100) from 5.0 to 30.0, or from 7.0 to 28, or from 8.0 to 27, or from 9.0 to 23.0; and/or

(viii) 0 ppb, or from greater than 0 ppb to less than 100 ppb chromium ; and/or (ix) an I2 value from 0.6 g/10 min to 1.2 g/10 min, or from 0.7 g/10 min to 1.1 g/10 min; and

(B) from 1.3 wt% to 4.5 wt%, or from 1.8 wt% to 3.6 wt%, or from 2.25 wt% to 3.15 wt%, or 2.6 wt% carbon black, carbon black weight percent is based on total weight of the composition (hereafter composition2).

[0056] The composition may include one or more optional additives. When present, nonlimiting examples of suitable additive include antioxidants, colorants, corrosion inhibitors, lubricants, moisture cure catalysts, ultraviolet (UV) absorbers or stabilizers, anti-blocking agents, coupling agents, compatibilizers, plasticizers, fillers, processing aids, and combinations thereof. When present the additives amount to from 0.05 wt% to 5.0 wt%, or from 0.1 wt% to 1.0 wt%, or from 0.1 wt% to 0.5 wt% of the polyethylene composition, wherein wt% is based on the total weight of the polyethylene composition.

[0057] In an embodiment, the composition includes

(A) from 90 wt % to 97 wt%, or from 92 wt% to 96 wt%, or from 93 wt% to 95 wt% of a base bimodal ethylene/C4-C8 α-olefin copolymer, the base bimodal ethylene/C4-C8 α-olefin copolymer prior to blending with the carbon black, having one, some, or all of the following properties:

(vi) 0 parts per billion (ppb), or from greater than 0 ppb to 80 ppb, or from 1 ppb to 50 ppb boron; and/or

(viii) 0 ppb, or from greater than 0 ppb to less than 100 ppb chromium; and/or (ix) an I2value from 0.6 g/10 min to 1.2 g/10 min, or from 0.7 g/10 min to 1.1 g/10 min;

(B) from 1.3 wt% to 4.5 wt%, or from 1.8 wt% to 3.6 wt%, or from 2.25 wt% to 3.15 wt%, or 2.6 wt% carbon black;

(C) from 0.01 wt% to 0.1 wt% of a sulfur-containing antioxidant (such as IRGANOX 1035 for example); and/or

(D) from 0.1 wt% to 0.9 wt% of an amine-containing antioxidant (such as NAUGARD SuperQ for example); and/or

(E) from 0.01 wt% to 0.9 wt% of a fluoro-processing aid (such as DYNAMAR FX 5912, for example), component weight percent based on total weight of the composition (hereafter composition3).

[0058] In an embodiment, the carbon black of compositions is from a carbon black masterbatch and the composition includes from 1.7 wt% to 5.5 wt% of a second polyethylene (the carrier resin of the carbon masterbatch), based on total weight of compositions. The second polyethylene is LLDPE, LDPE, and combinations thereof.

3. Cable

[0059] The present disclosure provides a cable. In an embodiment, the cable includes (i) a conductor and (ii) a cable jacket on the conductor. The cable jacket may be an internal layer (non-surface layer) of the cable, or the cable jacket may be the outermost layer (surface layer) of the cable. The "outermost layer" is a layer with an outer surface that is exposed to, or substantially exposed to, ambient environment.

[0060] A "conductor," as used herein, is one or more wire(s) or fiber(s) for conducting heat, light, and/or electricity. The conductor may be a single wire/fiber or a multi-wire/fiber and may be in strand form or in tubular form. Non-limiting examples of suitable conductors include metals such as silver, gold, copper, carbon, and aluminum. The conductor may also be an optical fiber made from either glass or plastic.

[0061] A "cable," as used herein, is at least one wire or optical fiber within a sheath, e.g., a cable jacket or a protective outer jacket. Typically, a cable is two or more wires or two or more optical fibers bound together, typically in a common cable jacket or covering and/or protective jacket. The individual wires or fibers inside the sheath may be bare, covered or insulated. Combination cables may contain both electrical wires and optical fibers. The cable can be designed for telecommunication applications. The cable can be designed for low, medium, and/or high voltage applications. Alternating current cables can be prepared according to the present disclosure, which can be low voltage, medium voltage, high voltage, or extra-high voltage cables. Further, direct current cables can be prepared according to the present disclosure, which can include high or extra-high voltage cables. Insulated electrical conductors normally include a conductive core covered by a cable jacket. The conductive core can be solid or braided (for example, a bundle of threads). Some insulated electrical conductors may also contain one or more additional elements, such as a semiconductor layer (or layers) and/or a protective cover (for example, coiled wire, tape or sheath). Examples are coated metal wires and electrical cables, including those for use in low voltage ("LV", 0 to <5 kilovolts (kV) electricity distribution/transmission applications), medium voltage ("MV", 5 to <69 kV), high voltage ("HV", 69 to 230 kV) and extra-high voltage ("EHV", >230 kV). Power cable assessments can use AEIC/ICEA standards and/or IEC test methods.

[0062] In an embodiment, the coated conductor is selected from a fiber optic cable, a communications cable (such as a telephone cable or a local area network (LAN) cable), a power cable, wiring for consumer electronics, a power charger wire for cell phones and/or computers, computer data cords, power cords, appliance wiring material, home interior wiring material, consumer electronic accessory cords, and any combination thereof.

[0063] The cable includes the conductor and the cable jacket on, or otherwise surrounding, the conductor. The cable jacket includes the composition (as previously disclosed herein) composed of (A) base bimodal ethylene/C4-C8 α-olefin copolymer, and optionally (B) carbon black, with optional additives. In an embodiment, the cable jacket (composed of the present composition) directly contacts the conductor. The term "directly contacts" refers to a layer configuration whereby the cable jacket is located immediately adjacent to the conductor and no intervening layers or no intervening structures are present between the conductor and the cable jacket. Alternatively, the cable jacket indirectly contacts the conductor.

[0064] In an embodiment, the cable includes a conductor, and a cable jacket on the conductor. The cable jacket includes the composition composed of (A) the base bimodal ethylene/α-olefin copolymer as an ethylene/C4-C8 α-olefin copolymer, or ethylene/octene copolymer having one, some, or all of the following properties having one, some, or all of the following properties:

(v) an SHI value (η0.1/η100) from 5.0 to 30.0, or from 7.0 to 28, or from 8.0 to 27, or from 9.0 to 23.0; and/or

(viii) 0 ppb, or from greater than 0 ppb to less than 100 ppb chromium; and/or

(ix) an I2 value from 0.6 g/10 min to 1.2 g/10 min, or from 0.7 g/10 min to 1.1 g/10 min (compositionl). The cable jacket has:

(1) an aged break stress from 2100 psi to 2900 psi, and/or

(2) an aged elongation at break from 500% to 700%, or from 525% to 680%, and/or

(3) a surface roughness Ra value from 5.0 p-in to 25 p-in, or from 10.0 p-in to 25 p-in, or from 8.0 p-in to 24 p-in. In a further embodiment, the cable jacket is an internal layer.

[0065] In an embodiment, carbon black masterbatch and additives, are pre-compounded into LLDPE resin using a Banbury mixer to completely disperse the carbon black and additives and produce homogeneous pellets composed of carbon black masterbatch, additives and LLDPE resin ("pre-compounded pellets"). Pellets of the base bimodal ethylene/C4-C8 α-olefin copolymer are introduced into an extruder for extrusion onto a wire (wire extrusion). The pre-compounded pellets are delivered directly into the extruder (hereafter referred to as "BK").

[0066] In an embodiment, pellets of the base bimodal ethylene/C4-C8 α-olefin copolymer are introduced into an extruder for extrusion onto a wire (wire extrusion). Additives are delivered directly into the extruder via carbon black masterbatch pellets (hereafter referred to as "inline.") [0067] In an embodiment, the cable includes a conductor, and a cable jacket on the conductor. The cable jacket includes the composition composed of

(viii) 0 ppb, or from greater than 0 ppb to less than 100 ppb chromium; and/or

(ix) an I2value from 0.6 g/10 min to 1.2 g/10 min, or from 0.7 g/10 min to 1.1 g/10 min

(E) from 0.1 wt% to 0.9 wt% of a fluoro-processing aid (such as DYNAMAR FX 5912, for example), component weight percent based on total weight of the composition (hereafter composition3). The cable jacket has: (1) an aged break stress from 3400 psi to 4200 psi, or from 3450 psi to 4100 psi, and/or

(2) an aged elongation at break from 600% to 800%, or from 600% to 700%, and/or

(3) a surface roughness Ra value from 5.0 p-in to 20 p-in, or from 6.0 p-in to 19.0 p- in, or from 7.0 p-in to 18.0 p-in, or from 8.0 p-in to 17.0 p-in, or from 8.5 p-in to 16.0 p-in. In a further embodiment, the cable jacket is an outermost layer of the cable.

[0068] In an embodiment, the carbon black of composition3 is from a carbon black masterbatch and the cable jacket includes from 1.7 wt% to 5.5 wt% of a second polyethylene (the carrier resin of the carbon masterbatch), based on the total weight of the cable jacket. The second polyethylene is LLDPE, LDPE, and combinations thereof.

[0069] By way of example, and not limitation, some embodiments of the present disclosure will now be described in detail in the following Examples.

EXAMPLES

1. Polymerization of the base bimodal ethylene/C4-C8 α-olefin copolymer

[0070] 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 high purity 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 pressurized to above reaction pressure. All reaction feed flows are measured with mass flow meters and independently controlled with computer automated valve control systems.

[0071] 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, ethylene monomer, octene 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 the first 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. The primary catalyst component feed is computer controlled to maintain the reactor monomer conversion at the specified target. The cocatalyst component is fed to maintain a specified Al concentration 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 the reactor loop is provided by a pump.

[0072] 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, ethylene monomer, octene comonomer, hydrogen, and catalyst component feeds is possible. The total fresh feed stream to the second reactor (solvent, ethylene monomer, octene comonomer, and hydrogen) is temperature controlled by passing the feed stream through a heat exchanger. The total fresh feed to the second 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 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 calculated specified molar ratios to the primary catalyst component. Immediately following each reactor feed 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 the second reactor loop is provided by a pump.

[0073] The effluent from the first polymerization reactor (containing solvent, ethylene monomer, octene comonomer, hydrogen, catalyst components, and polymer) exits the first reactor and is added to the second reactor. 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 it is deactivated with the addition of and reaction with a suitable reagent (water). At this same reactor exit location other additives are added for polymer stabilization during production and extrusion like Tetrakis(Methylene(3,5-Di-Tert-Butyl- 4-Hydroxyhydrocinnamate))Methane.

[0074] 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.

[0075] The reactor stream feed data flows that correspond to the values in Table 1A used to produce the examples are graphically described in Figure 2. The data are presented such that the complexity of the solvent recycle system is accounted for and the reaction system can be treated more simply as a once through flow diagram. Polymerization conditions are provided in Table 1A below, and the catalyst and cocatalyst components are described in Table IB below.

[0076] Table 1A below provides polymerization conditions for comparative samples ("CS") and inventive examples ("IE"), ethylene monomer, octene comonomer. In Table 2A, comparative sample 1 is DFDA-7530 NT. Table 1A

Table IB: Catalysts used from Table 1

[0077] Properties for the base bimodal ethylene/α-olefin C4-C8 α-olefin are provided in Tables 2A and 2B below. Table 2A - Unsaturation Properties for CS1-2 and IE 1-5.

*butene comonomer (all other samples octene comonomer) 5per 1000C

Table 2B - Properties for CS1-2 and IE1-5 natural, no carbon black ("NT")

^%g/mol, * r)0.1/r) 100, ^&ohm/cm

⁺Ra was measured on cable jacket extruded onto wire. sAged break stress and aged elongation @ break were measured on tensile bars cut from 75 mil plaques.

®CS1-NT is DFDA-7530 NT

2. Carbon black formulations for cable jacket

[0078] The materials for producing cable jacket with carbon black are provided in Table 3 below.

Table 3

[0079] Wires (conductor) with 0.125 in nominal diameter were produced at 350 ft/min and were coated with a jacket layer composed of the Inventive Examples (IE) and Comparative Samples (CS) using three different formulations: (1) the natural (NT) and no carbon black, (2) the black (BK) formulation precompounded in the Banbury mixer, and (3) the black formulation added inline at the extruder (BK inline).

[0080] Properties of the cable with cable jacket composed of the composition are provided in Table 2 above (no carbon black) and Table 4 (containing carbon black) below.

Table 4 - Cable Jacket Properties

*wt % carbon black jacket based on total weight of cable jacket

[0081] The molecular weight distribution (Mw/Mn) for each of IE1-NT through IE5-NT (7.03- 10.58) is larger than the Mw/Mn for CS2-NT (4.52) and comparable to the Mw/Mn for the gas phase LLDPE of CS1-NT (10.35). Consequently, IE1-NT through IE5-NT exhibit beneficial shear thinning, as seen in (i) the high values for η0.1/η 10,0 (9.5-25.8) and (ii) the high I21/I2 melt flow ratios (94.8-129.1) for each of IE1-NT through IE5-NT. The I21/I2 melt flow ratio (94.8-129.1) for each of IE1-NT through IE5-NT is greater than the I21/I 2 melt flow ratio for the gas phase LLDPE of CS1-NT (83.2). The effect of this shear thinning can be seen in the surface roughness in the extruded wires.

[0082] The surface roughness, (Ra), is lower for each IE1-NT through IE5-NT (13.6-23.4) compared to the surface roughness for CS2-NT (125 p-in) and is lower than the surface roughness for even the gas phase LLDPE in CS1-NT (26.5 p-in). In addition to improved (i.e., lower) surface roughness, IE1-NT through IE5-NT each has comparable performance for cable jacketing. Each of IE1-NT through IE5-NT has a higher aged break stress (2150.2-2882.2 psi) and has high or nearly as high aged elongation at break (549.0-675.8%) compared to aged break stress (1458.6 psi) and aged elongation at break (733.4%) for CS1-NT. In addition, all inventive examples have equivalent environmental stress crack resistance (ESCR in Table 4) with no failures, demonstrating IE1-IE5 are suitable for cable jacket applications.

[0083] 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 with the scope of the following claims.

Claims

1. A composition comprising:

(A) a base bimodal ethylene/C4-C8 α-olefin copolymer, the base bimodal ethylene/C4-C₈ α- olefin copolymer having

(i) a density from 0.91 g/cc to 0.93 g/cc,

(ii) an I 21/I2 from 90 to 140,

(iii) a Mw/Mn from 7.0 to 15.0,

(iv) an Mz less than 600,000 g/mol,

(v) an SHI (η0.1/η 100) value from 5.0 to 30.0,

(vi) from 0 ppb to 80 ppb boron; and

(vii) from 0 ppm to 5 ppm of fluorine.

2. The composition of claim 1 comprising

(A) from 90 wt % to 97 wt% of the base bimodal ethylene/C4-C₈ α-olefin copolymer; and

(B) from 1.3 wt% to 4.5 wt% carbon black.

3. The composition of any of claims 1-2 wherein the base bimodal ethylene/C₄-C₈ α-olefin copolymer has a melt index, I2, from 0.6 g/10 min to 1.2 g/10 min.

4. The composition of any of claims 1-3 wherein the composition comprises 0 ppb boron.

5. The composition any of claims 1-4 wherein the composition comprises 0 ppm fluorine.

6. The composition of any of claims 1-5 further comprising an additive selected from the group consisting of an anti-oxidant, a processing aid, and combinations thereof.

7. The composition of any of claims 1-6 further comprising

(C) from 0.01 wt% to 0.1 wt% of a sulfur-containing antioxidant;

(D) from 0.1 wt% to 0.9 wt% of an amine-containing antioxidant; and (E) from 0.01 wt% to 0.9 wt% of a fluoro-processing aid.

8. The composition of any of claims 1-7 wherein the composition has a property selected from the group consisting of

(1) an aged break stress from 2100 psi to 2900 psi,

(2) an aged elongation at break from 500% to 700%, and combinations thereof.

9. The composition of any of claims 1-8 wherein the composition comprises from 1.7 wt% to 5.5 wt% of a second ethylene-based polymer.

10. A cable comprising: a conductor; and a cable jacket on the conductor, the cable jacket composed of a composition comprising (A) a base bimodal ethylene/C₄-C₈ α-olefin copolymer, the base bimodal ethylene/C₄-C₈ α- olefin copolymer having

(i) a density from 0.91 g/cc to 0.93 g/cc,

(ii) an I 21/I2 from 90 to 140,

(iii) a Mw/Mn from 7.0 to 15.0,

(iv) an Mz less to 600,000 g/mol,

(v) an SHI (η0.1/η100 value from 5.0 to 30.0,

(vi) from 0 ppb to 80 ppb boron,

(vii) from 0 ppm to 5 ppm of fluorine; and the cable jacket has a surface roughness Ra value from 5.0 p-in to 25.0 p-in.

11. The cable of any of claims 10-11 wherein the base bimodal ethylene/C₄-C₈ α-olefin copolymer has a melt index, I2, from 0.6 g/10 min to 1.2 g/10 min.

12. The cable of any of claims 11-12 wherein the cable jacket comprises 0 ppb boron.

13. The cable any of claims 10-13 wherein the cable jacket comprises 0 ppm fluorine.

14. The cable of any of claims 10-14 wherein the cable jacket has a property selected from the group consisting of

(1) an aged break stress from 2100 psi to 2900 psi,

(2) an aged elongation at break from 500% to 700%, and combinations thereof.

15. The cable of any of claims 10-15 wherein the composition of the cable jacket comprises

(A) from 90 wt % to 97 wt% of the base bimodal ethylene/C4-C8 α-olefin copolymer; and

(B) from 1.3 wt% to 4.5 wt% carbon black.

16. The cable of any of claims 10-15 wherein the cable jacket further comprises

(C) from 0.01 wt% to 0.1 wt% of a sulfur-containing antioxidant;

(D) from 0.1 wt% to 0.9 wt% of an amine-containing antioxidant; and

(E) from 0.01 wt% to 0.9 wt% of a fluoro-processing aid.

17. The cable of any of claims 10-16 wherein the cable jacket comprises from 1.7 wt% to 5.5 wt% of a second ethylene-based polymer.

18. The cable of any of claims 15-17 wherein the cable jacket has a surface roughness Ra value from 6.0 p-in to 19.0 p-in.