COATED CONDUCTOR

Abstract

This description provides for a coated conductor. The coated conductor includes a conductor and an outer sheath over the conductor. The sheath includes (A) an ethylene-based polymer having an I₂ / I₂ ratio of 20 to 50; and (B) a propylene / ethylene copolymer having an Mw / Mn ratio of 2.0 to 3.5. The sheath has a surface roughness of 0.51 micrometers (20 microinches) to 2.54 micrometers (100 microinches).

Description

COATED CONDUCTOR BACKGROUND OF THE INVENTION Cables, such as power cables or communication cables, are a type of conductor that includes an internal conductive element, such as a metallic wire or fiberglass, and one or more outer layers for shielding and protection. The outermost covering, or outermost layer, of the cable is a protective layer typically called the outer jacket or outer sheath. Ethylene-based polymers are well-known for the manufacture of cable sheaths. Ethylene-based polymers for use in cable sheaths must have good processability, such as good extrusion properties over a wide range of processing temperatures. Furthermore, ethylene-based cable sheaths should generally have good mechanical properties. In general, cable sheaths made from ethylene-based solution resins (SR resins) with a 12 1 / 12 ratio of less than 50 are known to exhibit sufficient mechanical properties for cable applications. However, cable sheaths made from ethylene-based solution resins (SR resins) with a 12 1 / 12 ratio of less than 50 do not process well on extrusion equipment, resulting in unacceptable surface roughness at typical extrusion line speeds when compared to Ref. 314848 equivalent compounds based on gas phase polymerization resins (GP resins) with a wider molecular weight distribution (MWD). The technique recognizes the need to diversify and expand the types of polymer resins available for use in cable sheath applications that at the same time maintain adequate processability and suitable mechanical and performance properties. BRIEF DESCRIPTION OF THE INVENTION This description refers to a coated conductor. The coated conductor includes a conductor and an outer covering over the conductor. The covering includes (A) an ethylene-based polymer having a 121 / 12 ratio of 20 to 50; and (B) a propylene / ethylene copolymer having an Mw / Mn ratio of 2.0 to 3.5. The covering has a surface roughness of 0.51 micrometers (20 microinches) to 2.54 micrometers (100 microinches). BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a graph showing the impact on surface roughness of the amount of propylene / ethylene copolymer in cover samples containing LLDPE. Figure 2 is a graph showing the impact on surface roughness of the amount of propylene / ethylene copolymer in cover samples containing MDPE. DETAILED DESCRIPTION OF THE INVENTION DEFINITIONS All references to the periodic table of the elements are according to the one published by CRC Press, Inc., 1990-1991. References to a group of elements in this table are according to the new numbering group notation. For the purposes of United States patent practice, the contents of any patent, patent application, or publication referenced herein are incorporated by reference in their entirety (or their equivalent U.S. version is incorporated by reference) especially with respect to the description of definitions (to the extent they are not contradictory to any of the definitions specifically provided in this description) and general knowledge in the art. The numerical intervals described in this document include all values ​​from the lowest to the highest inclusive. For intervals containing explicit values ​​(e.g., an interval from 1, or 2, or 3 to 5, or 6, or 7), any subinterval between any two explicit values ​​is included (e.g., the interval 1-7 above includes the subintervals 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6; etc.). Unless otherwise stated, implied by the context, or customary in the art, all parts and percentages are on a weight basis and all testing methods are current as of the date of submission of this description. The term "blend" or "polymer blend," as used herein, refers to a mixture of two or more polymers. The blend may be miscible or immiscible (without phase separation at the molecular level). The blend may or may not exhibit phase separation. The blend may or may not contain one or more domain configurations, as determined by transmission electron spectroscopy, light scattering, X-ray scattering, and other methods known in the art. The term "composition" refers to a mixture of materials comprising the composition, as well as reaction products and decomposition products formed from the composition materials. The expressions "comprising," "including," "having," and their derivatives are not intended to exclude the presence of any additional component, step, or process, whether specifically described or not. For the avoidance of doubt, all compositions claimed using the expression "comprising" may include any additive, adjuvant, or additional compound, whether polymeric or not, unless otherwise stated. Conversely, the expression "consisting essentially of" excludes from the scope of any further mention any other component, step, or process, except those that are not essential to performance. The expression "consisting of" excludes any component, step, or process that is not specifically defined or listed. The term "or," unless otherwise stated, refers to the members listed individually as well as in any combination.The use of the singular includes the use of the plural and vice versa. A "conductor" is one or more wires, or one or more fibers, for conducting heat, light, and / or electricity. The conductor may be a single wire or fiber, or multiple wires or fibers, and may be in strand or tubular form. Non-limiting examples of suitable conductors include carbon and various metals, such as silver, gold, copper, and aluminum. The conductor may also be optical fiber made of either glass or plastic. The conductor may or may not be encased in a protective sheath. A "cable" is a conductor in which two or more wires, or two or more optical fibers, are bundled together, optionally within a common insulating sheath. The individual wires or fibers within the sheath may be bare, covered, or insulated. Combination cables may contain both electrical wires and optical fibers. The cable may be designed for low-, medium-, and / or high-voltage applications. An "ethylene-based polymer" is a polymer containing more than 50 percent by weight of polymerized ethylene monomer (based on the total weight of polymerizable monomers) and may optionally contain at least one comonomer. Ethylene-based polymers include ethylene homopolymers and ethylene copolymers (units of meaning arising from ethylene and one or more comonomers). The terms "ethylene-based polymer" and "polyethylene" may be used interchangeably. Non-limiting examples of ethylene-based polymers (polyethylene) include low-density polyethylene (LDPE) and linear polyethylene.Non-limiting examples of linear polyethylene include linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (ULDPE), very low-density polyethylene (VLDPE), multi-component ethylene-based copolymer (EPE), ethylene / α-olefin multiblock copolymers (also known as olefin block copolymer (OBC)), single-site catalyzed linear low-density polyethylene (m-LLDPE), substantially linear or linear plastomers / elastomers, medium-density polyethylene (MDPE), and high-density polyethylene (HDPE).Polyethylene can generally be produced in gas-phase fluidized bed reactors, liquid-phase suspension process reactors, or liquid-phase solution process reactors using a heterogeneous catalyst system, such as the Ziegler-Natta catalyst, or a homogeneous catalyst system comprising Group 4 transition metals and ligand structures such as metallocene, metal-centered non-metallocene, heteroaryl, heterovalent aryloxy ether, phosphinimine, and others. Combinations of heterogeneous and / or homogeneous catalysts can also be used in both single-reactor and dual-reactor configurations. Ethylene plastomers / elastomers are substantially linear, or linear, ethylene / α-olefin copolymers containing a homogeneous short-chain branching distribution comprising ethylene-derived units and units derived from at least one C3C10 α-olefin comonomer, at least one C4-C8 α-olefin comonomer, or at least one Ce-Cs α-olefin comonomer. Ethylene plastomers / elastomers have a density of 0.870 g / cc, 0.880 g / cc, or 0.890 g / cc to 0.900 g / cc, 0.902 g / cc, 0.904 g / cc, 0.909 g / cc, 0.910 g / cc, or 0.917 g / cc. Non-limiting examples of ethylene plastomers / elastomers include AFFINITY™ plastomers and elastomers (available from The Dow Chemical Company), EXACT™ plastomers (available from ExxonMobil Chemical), Tafmer™ (available from Mitsui), Nexlene™ (available from SK Chemicals Co.), and Lucene™ (available from LG Chem Ltd.). "High-density polyethylene" (or "HDPE") is an ethylene homopolymer or an ethylene / α-olefin copolymer having at least one C4-C10 α-olefin comonomer or one C4 α-olefin comonomer and a density of more than 0.94 g / cc, 0.945 g / cc, 0.95 g / cc, or 0.955 g / cc to 0.96 g / cc, 0.97 g / cc, or 0.98 g / cc. HDPE can be a monomodal copolymer or a multimodal copolymer. A "monomodal ethylene copolymer" is an ethylene / C4-C10 α-olefin copolymer that has a defined peak on gel permeation chromatography (GPC) showing the molecular weight distribution. An "interpolymer" is a polymer made by the polymerization of at least two different monomers. This generic term includes copolymers, generally used to refer to polymers made from two different monomers, and polymers made from more than two different monomers, e.g., terpolymers, tetrapolymers, etc. A "cover" is a covering over the driver. Linear low-density polyethylene (or LLDPE) is a linear ethylene / α-olefin copolymer containing a heterogeneous short-chain branching distribution comprising ethylene-derived units and units derived from at least one C3-C10 α-olefin comonomer, at least one C4-C8 α-olefin comonomer, or at least one Ce-Cs aolefin comonomer. LLDPE is characterized by little to no long-chain branching, unlike conventional LDPE. LLDPE has a density of 0.916 g / cc to 0.925 g / cc. Non-limiting examples of LLDPE include TUFLIN™ linear low-density polyethylene resins (available from The Dow Chemical Company), DOWLEX™ polyethylene resins (available from The Dow Chemical Company), and MARLEX™ polyethylene (available from Chevron Phillips). Low-density polyethylene (or LDPE) is an ethylene homopolymer or an ethylene / α-olefin copolymer comprising at least one C3-C10 α-olefin, or one C3C4 α-olefin, having a density of 0.915 g / cc to 0.925 g / cc and containing long-chain branches with broad molecular weight distribution (MWD). Typically, LDPE is produced by high-pressure free-radical polymerization (tubular reactor or autoclave with a free-radical initiator). Non-limiting examples of LDPE include MarFlex™ (Chevron Phillips), LUPOLEN™ (LyondellBasell), and LDPE products from Borealis, Ineos, ExxonMobil, and others. Medium-density polyethylene (or "MDPE") is an ethylene homopolymer, or an ethylene / α-olefin copolymer comprising at least one C3-C10 α-olefin, or one C3C4 α-olefin, having a density of 0.926 g / cc to 0.940 g / cc. The “multi-component ethylene-based copolymer” (or “EPE”) comprises ethylene-derived units and units derived from at least one C3-C10 α-olefin comonomer, at least one C4-C8 α-olefin comonomer, or at least one Ce-Cs α-olefin comonomer, as described in USP 6,111,023; USP 5,677,383; and USP 6,984,695. EPE resins have a density of 0.905 g / cc, 0.912 g / cc, or 0.920 g / cc to 0.940 g / cc or 0.962 g / cc. Non-limiting examples of EPE resins include ELITE™ enhanced polyethylene (available from The Dow Chemical Company), ELITE AT™ advanced technology resins (available from The Dow Chemical Company), SURPASS™ polyethylene (PE) resins (available from Nova Chemicals) and SMART™ (available from SK Chemicals Co.). A "multimodal ethylene copolymer" is a C4-C10 ethylene / α-olefin copolymer that has at least two defined peaks on a GPC showing the molecular weight distribution. Multimodal includes copolymers with two peaks (bimodal) as well as copolymers with more than two peaks. Non-limiting examples of HDPE include DOW™ high-density polyethylene (HDPE) resins (available from The Dow Chemical Company), ELITE™ enhanced polyethylene resins (available from The Dow Chemical Company), CONTINUUM™ bimodal polyethylene resins (available from The Dow Chemical Company), LUPOLEN™ (available from LyondellBasell), and HDPE products from Borealis, Ineos, and ExxonMobil. An "olefin-based polymer," as used herein, is a polymer containing more than 50 mol% of polymerized olefin monomer (based on the total amount of polymerizable monomers) and may optionally contain at least one comonomer. Non-limiting examples of olefin-based polymers include ethylene-based polymers and propylene-based polymers. A "polymer" is a compound made by the polymerization of monomers, whether of the same or different types, which in their polymerized form provide the multiple and / or repeating "units" or "mer units" that form a polymer. Therefore, the generic term polymer encompasses the term homopolymer, generally used to refer to polymers made from a single type of monomer, and the term copolymer, generally used to refer to polymers made from at least two types of monomers. It also encompasses all forms of copolymer, e.g., random, block, etc. The expressions "ethylene / α-olefin polymer" and "propylene / α-olefin polymer" indicate a copolymer as described above made from the polymerization of ethylene or propylene, respectively, and one or more additional polymerizable α-olefin monomers.It is important to note that, while polymers are often referred to as "made from" one or more specific monomers, "based on" a specific monomer or type of monomer, "containing" a specific monomer content, or similar terms, in this context the term "monomer" refers to the polymerized remnant of the specific monomer and not to the unpolymerized form. Generally, throughout this document, polymers are referred to in terms of "units," which are the polymerized form of a corresponding monomer. A "propylene-based polymer" is a polymer containing more than 50 mol% of polymerized propylene monomer (based on the total amount of polymerizable monomers) and may optionally contain at least one comonomer. Propylene-based polymers include propylene homopolymers and propylene copolymers (i.e., propylene-derived units and one or more comonomers). The terms "propylene-based polymer" and "polypropylene" may be used interchangeably. A non-limiting example of a propylene-based polymer (polypropylene) is a propylene / α-olefin copolymer having at least one C2 or C4-C10 α-olefin comonomer. "Single-site catalyzed linear low-density polyethylenes" (or "m-LLDPE") are linear ethylene / α-olefin copolymers containing a homogeneous short-chain branching distribution comprising ethylene-derived units and units derived from at least one C3-C10 α-olefin comonomer, at least one C4-C8 aolefin comonomer, or at least one Ce-Cs α-olefin comonomer. m-LLDPE has a density of 0.913 g / cc, 0.918 g / cc, or 0.920 g / cc to 0.925 g / cc or 0.940 g / cc. Non-limiting examples of m-LLDPE include EXCEED™ metallocene PE (available from ExxonMobil Chemical), LUFLEXEN™ m-LLDPE (available from LyondellBasell), and ELTEX™ m-LLDPE (available from Ineos). Olefins & Polymers is available). Each of "ultra-low density polyethylene" (or "ULDPE") and "very low density polyethylene" (or "VLDPE") is a linear ethylene / α-olefin copolymer containing a heterogeneous short-chain branching distribution comprising ethylene-derived units and units derived from at least one C3-C10 α-olefin comonomer, at least one C4-C8 α-olefin comonomer, or at least one Cg-Cs aolefin comonomer. Each of ULDPE and VLDPE has a density of 0.885 g / cc or 0.90 g / cc to 0.915 g / cc. Non-limiting examples of ULDPE and VLDPE include ATTANE™ ULDPE resins (available from The Dow Chemical Company) and FLEXOMER™ VLDPE resins (available from The Dow Chemical Company). TEST METHODS Density is measured according to ASTM D7 92 with values ​​expressed in grams per cubic centimeter (g / cc or g / cm3). The melt flow rate (MFR) is measured at 230 °C with a load of 2.16 kg according to ASTM D1238 and is expressed in grams eluted per 10 minutes (g / 10 min). The melt flow index (12) is measured at 190 °C with a load of 2.16 kg according to ASTM D1238 and is expressed in grams eluted per 10 minutes (g / 10 min). The melt flow index (110) is measured at 190 °C with a load of 10.0 kg according to ASTM D1238 and is expressed in grams eluted per 10 minutes (g / 10 min). The melt flow index (121) is measured at 190 °C with a load of 21.0 kg according to ASTM D1238 and is expressed in grams eluted per 10 minutes (g / 10 min). The melt flow index 121 / 12, or "121 / 12 ratio," is an indirect measure of the viscosity ratio at high and low shear rates. It indicates shear fluidization behavior related to both molecular weight distribution (MWD) and the presence of long-chain branching, each of which significantly affects processability. Generally, polyethylene containing long-chain branching has high melt strength and low viscosity at high shear rates, allowing for higher processing speeds compared to polyethylene with little or no long-chain branching. Relaxation spectrum index (RSI) and normalized relaxation spectrum index (nRSI). The RSI and nRSI are rheological indicators of molecular weight distribution. The RSI is determined by subjecting the polymer or composition to shear deformation and measuring its response to deformation using a rheometer. The dynamic oscillatory shear test is performed at 190 °C with a strain of 0.25% using 25 mm plates at a speed of 0.01 to 100 rad / s. As is known in the art, depending on the polymer response and the mechanics and geometry of the rheometer used, the relaxation modulus G(t) or the dynamic moduli G'(ω) and G(ω) can be determined as functions of time, t, or frequency, ω, respectively (see JM Dealy & KF Wissbrun, Melt Rheology and Its Role in Plastics Processing 269-297 (1990)).The mathematical connection between the dynamic and storage moduli is an integral relationship of the Fourier transform, but one data set can also be calculated from the other using the known relaxation spectrum (see SH Wasserman, 39 J. Rheology 601-625 (1995)). Using a classical mechanical model, a discrete relaxation spectrum can be defined consisting of a series of relaxations or “modes,” each with a characteristic intensity or “weight” and relaxation time. Using the spectrum, the moduli are re-expressed as: Equation (A) G^ = ^ígi Equation (B) G(t) = Equation (C) where N is the number of modes and gi and A± are the weight and time for each of the modes (see JD Ferry, Viscoelastic Properties of Polymers 224-263 (1980)). A relaxation spectrum for the polymer or composition can be defined using software such as IRIS® rheology software, which is commercially available from IRIS Development. Once the mode distribution in the relaxation spectrum has been calculated, the first and second moments of the distribution, which are analogous to Mny and Mw, the first and second moments of the molecular weight distribution, are calculated as follows: ywa. , gj = g Equation (D) gn = Equation (E) / 2,¿=i 9i RSl = ^ / g¡Equation (F) The nRSI is calculated as follows: nRSI = RSI x MI05 Equation (G), where MI is the melt flow index (12). Because the RSI is sensitive to parameters such as the molecular weight distribution, molecular weight, and long-chain branching of a polymer, it is a sensitive and reliable indicator of a polymer's stress relaxation. The higher the nRSI value, the wider the polymer's relaxation time distribution and, therefore, the better the polymer's (and additionally, the composition's) processability. A higher RSI or nRSI indicates a higher molecular weight distribution in polymers without long-chain branching. Surface roughness. The surface roughness of a deck is measured according to ANSI 1995 using a Surftest SV-400 Series 178 surface texture measuring instrument. A wire sample is placed in a V-block, and the stylus (10 urns) is lowered to a specific starting position (approximately 1 gram of force is applied to the wire). At a fixed speed of 2 millimeters per second, the stylus is moved in the transverse direction, taking measurements. Four readings are taken per wire sample, and the four samples are then averaged, with values ​​expressed in microinches. Tensile Properties. This cover can be characterized by its tensile strength at break (in megapascals, MPa) and elongation at break (%). Tensile strength (“TS”) and elongation at break are measured in accordance with the ASTM D638 test procedure on compression-molded specimens prepared according to ASTM D4703. Elongation at break (“TE”), or elongation to break, is the deformation in a specimen when it breaks, expressed as a percentage. Aged tensile strength and aged elongation at break are measured after holding a specimen at 100°C for 10 days. Tensile strength retention is the aged tensile strength divided by the unaged tensile strength and is expressed as a percentage.The retention of elongation at break is the aged elongation at break divided by the unaged elongation at break and is expressed as a percentage. The Tm or "melting point" (also called the melting peak in reference to the shape of the plotted DSC curve) is measured using the DSC (differential scanning calorimetry) technique to measure the melting points or peaks of polyolefins as described in USP 5,783,638. It is worth noting that many mixtures comprising two or more polyolefins will have more than one melting point or peak; many individual polyolefins will comprise only one melting point or peak. Experimental 13C NMR procedure for propylene / ethylene copolymers 13C NMR is used to obtain ethylene content, Koenig B value, triad distribution and triad tacticity and is performed as follows: Sample preparation (propylene / ethylene copolymers). Samples are prepared by adding approximately 2.7 g of a 50 / 50 tetrachloroethane-d2 / orthodichlorobenzene mixture containing 0.025 MCr(AcAc)3 to 0.20–0.30 g of sample in a 10 mm Norell 1001-7 NMR tube. The samples are dissolved and homogenized by heating the tube and its contents to 150 °C using a heating block and heat gun. Each sample is visually inspected to ensure homogeneity. Data Acquisition Parameters (Propylene / Ethylene Copolymers). Data were collected using a 400 MHz Bruker spectrometer equipped with a Bruker Dual DUL high-temperature CryoProbe. Data were acquired using 320 transients per data file, a pulse repetition delay of 6 seconds, rotation angles of 90 degrees, and restricted reverse decoupling with a sample temperature of 120 °C. All measurements were performed on non-rotating samples in locked mode. Samples were allowed to thermally equilibrate for 7 minutes before data acquisition. The tacticity percentage in mm and the wt% ethylene were then determined according to methods commonly used in the art.* *References: For composition (wt% E): S. Di Martino & M. Kelchtermans; 56 J. Appl. Polym. Sci. 17811787 (1995); Tacticity, detailed assignments: V. Busico & R. Cipullo; 26 Prog. Polym. Sci.443-533 (2001). The "Koenig B-value" or chi-square statistic is a measure of randomness or blockiness in a random propylene / ethylene copolymer. A value of 1.0 indicates a random copolymer, and a value of zero indicates complete blocks of monomers A and B. A B-value of 2 indicates an alternating copolymer. B = [EP] / (2[P][E]), where [EP] is the total mole fraction of EP dimers (EP+PE, or (EEP+PPE+PEP+EPE)), and [E] is the mole fraction of ethylene, and [P] = 1 - [E]. Jack L. Koenig, Spectroscopy of Polymers (2nd ed. 1999). 1H NMR analysis: total unsaturation per mole of propylene Samples are prepared by adding approximately 3.25 g of a 50 / 50 tetrachloroethaned2 / perchloroethylene mixture in 0.0015 M chromium acetylacetonate (relaxing agent) to a 0.130 g sample in a 10 mm NMR tube. The samples are dissolved and homogenized by heating the tube and its contents to 110 °C. Data are collected using a 400 MHz Bruker spectrometer equipped with a Bruker Dual DUL high-temperature CryoProbe. Unsaturation data are collected using four scans per data file, a pulse repetition delay of 15.6 seconds, and a sample temperature of 120 °C. Acquisition is performed using a spectral width of 10,000 Hz and a file size of 16 K data points. The presaturation experiment is run with a modified pulse sequence, lclprf2.zzl, using 100 sweeps per data file.The following calculations are used: Moles of H of propylene: mole fraction of propylene * (integral area δ 3.5 - 0.2ppm) Total moles of propylene % molar of vinyl unsaturation / mol of propylene moles of H of propylene1Q0*motes of protons Total moles of propylene % molar of cis / trans unsaturation / mol of propylene. 100 ' cis / trans moles Total ds moles of propylene % molar of trisubstituted unsaturation / mol of propylene 100 * moles trisus. Total moles of propylene % molar unsaturation of vinylidene / mol of propylene 100 moles of vinylidene Total moles of propylene Total molar % of unsaturation / mol of propylene Molar % of vinno + molar cis / trans + molar % trisus. + mol + vinylidene Gel permeation chromatography (GPC) A high-temperature gel permeation chromatography (GPC) system, equipped with an automated assisted delivery (RAD) system, is used for sample preparation and injection. The concentration detector is an infrared (IR-5) detector from Polymer Char Inc. (Valencia, Spain). Data acquisition is performed using a Polymer Char DM 100 data acquisition box. The carrier solvent is 1,2,4-trichlorobenzene (TCB). The system is equipped with an Agilent online solvent degassing device. The column compartment is operated at 150 °C. The columns are four 30 cm x 20 µm Mixed A LS columns. The solvent is nitrogen-purged 1,2,4-trichlorobenzene (TCB) containing approximately 200 ppm of 2,6-di-tert-butyl-4-methylphenol (BHT). The flow rate is 1.0 mL / min and the injection volume is 200 μA.A sample concentration of "2 mg / mL" is prepared by dissolving the sample in preheated and N2-purged TCB (containing 200 ppm of BHT) for 2.5 hours at 160 °C, with gentle stirring. The GPC column array is calibrated by running twenty polystyrene standards with a narrow molecular weight distribution. The molecular weight (MW) of the standards ranges from 580 g / mol to 8,400,000 g / mol, and the standards are contained in six "cocktail" mixtures. Each standard mixture has at least a ten-unit separation between individual molecular weights. The equivalent polypropylene molecular weights of each PS standard are calculated using the following equation, with the Mark-Houwink coefficients reported for polypropylene (Th.G. Scholte, NLJ Meijerink, HM Schoffeleers, & AMG Brands, J. Appl. Polym. Sci., 29, 3763-3782 (1984)) and polystyrene (EP Otocka, RJ Roe, NY Hellman, & PM Muglia, Macromolecules, 4, 507 / A'ov M “PP+1 Mpp = .. --- (1971) ) : (Eq. 1) , where MPP is the equivalent MW of PP, Mps is the equivalent MW of PS, log K and the values ​​a of the Mark-Houwink coefficients for PP and PS are listed below. Polymer at log K Polypropylene 0.725 -3.721 Polystyrene 0.702 -3.900 A logarithmic molecular weight calibration is generated using a fourth-order polynomial fit as a function of the elution volume. The number and weight average molecular weights are calculated according to the following equations: (Eq. 2),=(Eq. 3), where Wfi and Mi are the weight fraction and molecular weight of elution component i, respectively. This description provides for a coated conductor. The coated conductor includes a conductor and an outer sheath over the conductor. The sheath contains (A) an ethylene-based polymer having a 121 / 12 ratio of 20 to 50; and (B) a propylene / ethylene copolymer having an Mw / Mn ratio of 2.0 to 3.5. The sheath has a surface roughness of 0.51 micrometers (20 microinches) to 2.54 micrometers (100 microinches). i. Conductor The coated conductor includes a conductor. The conductor may be a single wire or fiber, or multiple wires or fibers, and may be in strand or tubular form. Non-limiting examples of suitable conductors include carbon and various metals, such as silver, gold, copper, and aluminum. The conductor may also be optical fiber made of either glass or plastic. The conductor may or may not be encased in a protective sheath. In one configuration, the conductor is a cable. A "cable" is a conductor in which two or more wires, or two or more optical fibers, are bundled together, optionally within a common insulating sheath. The individual wires or fibers within the sheath may be bare, covered, or insulated. Combination cables may contain both electrical wires and optical fibers. The cable can be designed for low, medium, and / or high-voltage applications. The driver may understand two or more of the modalities described in this document. ii. Outermost cover The coated conductor includes an outer covering over the conductor. The covering contains (A) an ethylene-based polymer having a 121 / 12 ratio of 20 to 50; and (B) a propylene / ethylene copolymer having an Mw / Mn ratio of 2.0 to 3.5; and (C) an optional additive. A. Ethylene-based polymer The cover includes (A) an ethylene-based polymer having a 121 / 12 ratio of 20 to 50. The ethylene-based polymer may be an ethylene homopolymer or an ethylene / α-olefin copolymer. Non-limiting examples of suitable α-olefin comonomers for the ethylene-based polymer include C3-C20 α-olefin, C4-C12 α-olefin, or C4-C8 α-olefin. Additional non-limiting examples of suitable α-olefin comonomers include propylene, butene, methyl-1-pentene, hexene, octene, decene, dodecene, tetradecene, hexadecene, octadecene, cyclohexyl-1-propene (allylcyclohexane), vinylcyclohexane, and combinations thereof. In one embodiment, the α-olefin comonomer for the ethylene-based polymer is selected from butene, hexene, or octene. In one embodiment, the ethylene-based polymer is selected from LLDPE, MDPE, HDPE, and combinations thereof. In one embodiment, the ethylene-based polymer is selected from an LLDPE, an MDPE, and combinations of these. The ethylene-based polymer has a 121 / 12 ratio of 20 to 50. In one embodiment, the ethylene-based polymer has a 121 / 12 ratio of 20, 22 or 24 to 30, 32, 35, 40 or 50. In one embodiment, the ethylene-based polymer has a melting point, Tm, of 115 °C or 120 °C to 125 °C, 127 °C or 130 °C. In one embodiment, the ethylene-based polymer is an MDPE with a 121 / 12 ratio of 20, 22, or 25 to 27, 30, 32, 35, 40, or 50. The MDPE is an ethylene / C4-C8 α-olefin copolymer, or additionally an ethylene / octene copolymer. The MDPE has one, some, or all of the following properties: (i) a density of 0.926 g / cc, 0.930 g / cc, or 0.935 g / cc to 0.940 g / cc; and / or (ii) a 12 of 0.5 g / 10 min, 1.0 g / 10 min, 1.5 g / 10 min, 2.0 g / 10 min or 2.4 g / 10 min to 3.0 g / 10 min, 4.0 g / 10 min, 4.3 g / 10 min or 4.5 g / 10 min; and / or (iii) a 121 of 35 g / 10 min, 40 g / 10 min, 50 g / 10 min or 60 g / 10 min to 70 g / 10 min, 80 g / 10 min, 90 g / 10 min, 97 g / 10 min or 100 g / 10 min; and / or (iv) a 110 of 5 g / 10 min, 10 g / 10 min or 11 g / 10 min to 30 g / 10 min, 35 g / 10 min or 40 g / 10 min; and / or (v) a melting point, Tm, of 120 °C, 122 °C or 125 °C to 127 °C or 130 °C; and / or (vi) an Mw / Mn of 2.5, 2.7 or 3.0 to 3.3, 3.5 or 4.0; and / or (vii) an nRSI of 10, 15 or 19 to 83, 85 or 90. In one embodiment, the ethylene-based polymer is an LLDPE with a 121 / 12 ratio of 20, 22, or 24 to 30, 31, 32, 35, 40, 45, or 50. The LLDPE is an ethylene / C4-C8 α-olefin copolymer, or additionally an ethylene / octene copolymer or an ethylene / hexene copolymer. The LLDPE has one, some, or all of the following properties: (i) a density of 0.916 g / cc or 0.917 g / cc to 0.919 g / cc, 0.920 g / cc, or 0.925 g / cc; and / or (ii) a 12 of 0.5 g / 10 min, 1.0 g / 10 min, 1.5 g / 10 min, 2.0 g / 10 min or 2.3 g / 10 min to 3.0 g / 10 min, 4.0 g / 10 min, 4.3 g / 10 min, 4.5 g / 10 min, 5 g / 10 min or 10 g / 10 min; and / or (iii) a 121 of 35 g / 10 min, 40 g / 10 min, 50 g / 10 min, g / 10 min, 70 g / 10 min or 71 g / 10 min to 80 g / 10 min, 87 g / 10 min, 90 g / 10 min or 100 g / 10 min; and / or (iv) a 110 of 5 g / 10 min, 10 g / 10 min, 15 g / 10 min or 20 g / 10 min to 25 g / 10 min, 30 g / 10 min, 35 g / 10 min or 40 g / 10 min; and / or (v) a melting point, Tm, of 120°C or 121°C to 123°C, 125°C, 127°C or 130°C; and / or (vi) a Mw / Mn of 2.5, 3.0 or 3.1 to 3.7, 4.0, 4.5 or 5.0; and / or (vii) an nRSI of 1 or 2 to 12, 15, 20, 25 or 30. In one form, the ethylene-based polymer is an HDPE with a 121 / 12 ratio of 20 or 25 to 30, 35, 40, 45 or 50. The HDPE has a density of more than 0.94 g / cc, 0.945 g / cc, 0.95 g / cc or 0.955 g / cc to 0.96 g / cc, 0.97 g / cc or 0.98 g / cc. In one embodiment, the cover contains from 60% by weight, 63% by weight or 70% by weight to 75% by weight, 80% by weight, 84% by weight, 85% by weight or 90% by weight of the ethylene-based polymer, depending on the total weight of the cover. The ethylene-based polymer may comprise two or more of the forms described in this document. B. Propylene / ethylene copolymer The cover includes a propylene / ethylene copolymer that has an Mw / Mn of 2.0 to 3.5. In one embodiment, the propylene / ethylene copolymer contains, essentially consists of, or comprises propylene, ethylene, an optional diene comonomer, and an optional additive. In one embodiment, the propylene / ethylene copolymer contains propylene and from more than 0% by weight, 1% by weight or 2% by weight to 5% by weight, 10% by weight, 15% by weight, 20% by weight or 25% by weight of ethylene comonomer, depending on the total weight of the propylene / ethylene copolymer. In one embodiment, the propylene / ethylene copolymer contains, consists essentially of, or consists of less than 100% by weight, 99% by weight, or 98% by weight to 97% by weight, 96% by weight, or 95% by weight of propylene-derived units and a reciprocal amount, or more than 0% by weight, 1% by weight, or 2% by weight to 3% by weight, 4% by weight, or 5% by weight of ethylene-derived units, depending on the total weight of the propylene / ethylene copolymer. The propylene / ethylene copolymer has an Mw / Mn of 2.0 to 3.5 or has an Mw / Mn of 2.0 to less than 3.5. In one embodiment, the propylene / ethylene copolymer has an Mw / Mn of 2.0 or 2.4 to 3.3, or less than 3.5, or 3.5. In one embodiment, the propylene / ethylene copolymer has a density of 0.880 g / cc, 0.885 g / cc or 0.887 g / cc to 0.890 g / cc, 0.891 g / cc, 0.895 g / cc, 0.900 g / cc or 0.905 g / cc. In one embodiment, the propylene / ethylene copolymer has a melt flow rate (MFR) of 2.0 g / 10 min, 3.0 g / 10 min, or 4.0 g / 10 min to 5.0 g / 10 min, 6.0 g / 10 min, 7.0 g / 10 min, 8.0 g / 10 min, 9.0 g / 10 min, 10.0 g / 10 min, 15.0 g / 10 min, 20.0 g / 10 min, or 25.0 g / 10 min. In one embodiment, the propylene / ethylene copolymer has a melt flow rate (MFR) of 2.0 g / 10 min to 10 g / 10 min or 2.0 g / 10 min to 8 g / 10 min. In one embodiment, the propylene / ethylene copolymer has a 12 of 0.5 g / 10 min or 0.8 g / 10 min to 3.3 g / 10 min, 3.5 g / 10 min, 5.0 g / 10 min or 10 g / 10 min. In one embodiment, the propylene / ethylene copolymer has a total unsaturation per mole of propylene of 0.01% or 0.015% to 0.025% or 0.03%. The total unsaturation per mole of propylene is measured by 1H NMR analysis as described above in the test methods section. In one embodiment, the propylene / ethylene copolymer has a crystallinity of 1 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt% to 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, or 70 wt%. In another embodiment, the propylene / ethylene copolymer has a crystallinity of 30 wt% to 70 wt%, or 40 wt% to 60 wt%, or 10 wt% to 40 wt%, or 20 wt% to 39 wt%. In one embodiment, the propylene / ethylene copolymer has a melting point, Tm, of 25°C, 40°C, 50°C, 75°C, 90°C, 100°C, or 105°C to 110°C, 120°C, 140°C, 150°C, 160°C, or 170°C. In one embodiment, the propylene / ethylene copolymer has a melting point, Tm, of 25°C, 40°C, 50°C, 75°C, 100°C, or 105°C to 110°C, 115°C, 116°C, or 120°C. In one embodiment, the propylene / ethylene copolymer has a single melting point. In one embodiment, the propylene / ethylene copolymer has a weight average molecular weight (Mw) of 20,000 g / mol, 24,000 g / mol or 30,000 g / mol to 40,000 g / mol, 48,000 g / mol or 50,000 g / mol. The term "B-value" is a measure of randomness and measures the distribution of the propylene and ethylene comonomer throughout the polymer chain of the propylene / ethylene copolymer. B-values ​​range from 0 to 2. The higher the B-value, the more alternate the distribution of ethylene in the propylene / ethylene copolymer. The lower the B-value, the more blocky or clumped the distribution of ethylene in the propylene / ethylene copolymer. In one embodiment, the propylene / ethylene copolymer has a B-value of less than 1.0, less than 0.99, less than 0.98, or less than 0.97. In another embodiment, the propylene / ethylene copolymer has a B-value of 0.90, 0.92, 0.93, or 0.94 to 0.95, 0.96, 0.97, 0.98, or 0.99. The B value described by Koenig, (Spectroscopy of Polymers (2nd ed. 1999) is calculated as follows. B is defined as „ f (EP + PE) D = -------Ί Ί- i / 4- i 2 · Fe · Fp for the propylene / ethylene copolymer as: , where f(EP + PE) = the sum of the dyad fractions of EP and PE; and Fe and Fp = the mole fraction of ethylene and propylene in the copolymer, respectively. The dyad fraction can be derived from the triad data according to: f(EP + PE) = [EPE] + [EPP+PPE] / 2 + [PEP] + [EEP+PEE] / 2. In one embodiment, the propylene / ethylene copolymer is characterized by having substantially isotactic propylene sequences. “Substantially isotactic propylene sequences” are sequences that have an isotactic triad (mm) measured by 13C NMR of more than 0.85, more than 0.90, more than 0.92, or more than 0.93. Isotactic triads refer to the isotactic sequence in terms of a triad unit in the copolymer molecular chain determined by 13C NMR spectroscopy. In one embodiment, the propylene / ethylene copolymer has an RSI of 10, 11 or 15 to 22, 25 or 30. In one embodiment, the propylene / ethylene copolymer has an nRSI of 15, 18 or 19 to 30, 31 or 35. In one embodiment, the propylene / ethylene copolymer has an Mw / Mn of 2.0 or 2.4 to 3.3 or 3.5 and the propylene / ethylene copolymer optionally has one, some or all of the following properties: (i) a density of 0.880 g / cc, 0.885 g / cc or 0.887 g / cc to 0.890 g / cc, 0.891 g / cc, 0.895 g / cc, 0.900 g / cc or 0.905 g / cc; and / or (ii) a melt flow rate (MFR) of 2.0 g / 10 min, 3.0 g / 10 min or 4.0 g / 10 min to 5.0 g / 10 min, 6.0 g / 10 min, 7.0 g / 10 min, 8.0 g / 10 min, 9.0 g / 10 min, 10.0 g / 10 min, 15.0 g / 10 min, 20.0 g / 10 min or 25.0 g / 10 min; and / or (iii) less than 100 wt., 99 wt. or 98 wt. to 97 wt., 96 wt., 95 wt., 90 wt. or 85 wt. of propylene-derived units and a reciprocal amount, or more than 0 wt., 1 wt. or 2 wt. to 3 wt., 4 wt., 5 wt., 10 wt. or 15 wt. of ethylene-derived units, based on the total weight of the propylene / ethylene copolymer; and / or (iv) a total unsaturation per mole of propylene of 0.01% to 0.025% or 0.03%; and / or (v) a crystallinity of 1 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt% or 30 wt% to 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt% or 70 wt%; and / or (vi) a melting temperature, Tm, of 25 °C, 50 °C, 75 °C, 100 °C or 105 °C to 110 °C, 115 °C, 116 °C, 120 °C, 140 °C or 150 °C; and / or (vii) a weight-average molecular weight (Mw) of 20,000 g / mol, 24,000 g / mol or 30,000 g / mol to 40,000 g / mol, 48,000 g / mol or 50,000 g / mol; and / or (viii) a B-value of 0.90, 0.93 or 0.94 to 0.95, 0.96, 0.97, 0.98 or 0.99; and / or (ix) sequences having an isotactic triad (mm) measured by 13C NMR of more than 0.85; and / or (x) a 12 from 0.5 g / 10 min or 0.8 g / 10 min to 3.3 g / 10 min, 3.5 g / 10 min, 5.0 g / 10 min or 10 g / 10 min; and / or (xi) an RSI of 10, 11 or 15 to 22, 25 or 30; and / or (xii) an nRSI of 15, 18 or 19 to 30, 31 or 35. In one embodiment, the propylene / ethylene copolymer has at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11 or all 12 properties (i) - (xii), as listed in the paragraph immediately preceding this one. In one embodiment, the propylene / ethylene copolymer has (i) an Mw / Mn of 2.0 or 2.4 to 3.3 or 3.5; and (ii) a melting point, Tm, of 25 °C, 40 °C, 50 °C, 75 °C, 100 °C or 105 °C to 110 °C, 115 °C, 116 °C, 120 °C, 140 °C or 150 °C. The propylene / ethylene copolymer can be prepared as described in International Publication No. WO 2009 / 067337, the full content of which is incorporated herein by reference. In one embodiment, the propylene / ethylene copolymer is a propylene-based plastomer or elastomer. Non-limiting examples of suitable propylene / ethylene copolymers that are propylene-based plastomers or elastomers are VERSIFY™ 3000 and VERSIFY™ 2000, which are available from The Dow Chemical Company. In one embodiment, the cover contains from 10% by weight or 15% by weight to 20% by weight, 25% by weight or 30% by weight of propylene / ethylene copolymer, depending on the total weight of the cover. The propylene / ethylene copolymer may comprise two or more of the forms described in this document. C. Optional additive In one form, the coating includes one or more optional additives. Non-limiting examples of suitable additives include carbon black, antioxidants, colorants, ultraviolet (UV) absorbers or stabilizers, antiblocking agents, flame retardants, compatibilizers, plasticizers, fillers, processing aids, and combinations thereof. In one embodiment, the cover contains carbon black. A non-limiting example of a suitable carbon black is DFNA-0037BK. In one embodiment, the cover contains from 1% by weight, 2% by weight, 3% by weight, or 5% by weight to 6% by weight, 7% by weight, 9% by weight, or 10% by weight of carbon black, depending on the total weight of the cover. In one embodiment, the coating contains an antioxidant. Non-limiting examples of suitable antioxidants include phenolic antioxidants, thio-based antioxidants, phosphate-based antioxidants, and hydrazine-based metal deactivators. In one embodiment, the coating contains an antioxidant, such as IRGANOX 1035, in an amount of 0.05 wt or 0.07 wt to 0.1 wt, 0.2 wt, 0.3 wt, 0.4 wt, or 0.5 wt, depending on the total weight of the coating. In one version, the cover contains a stabilizer. A non-limiting example of a suitable stabilizer is NAUGARD SUBER Q, which Chemtura offers. In one version, the cover contains from 0.1% or 0.2% by weight to 0.3%, 0.4%, or 0.5% by weight of stabilizer, depending on the total weight of the cover. In one version, the cover contains a filling. Non-limiting examples of suitable fillers include zinc oxide, zinc borate, zinc molybdate, zinc sulfide, organoclay, and combinations thereof. The filler may or may not have flame-retardant properties. In one embodiment, the coating contains a processing aid. Non-limiting examples of suitable processing aids include oils, organic acids (such as stearic acid), and metallic salts of organic acids (such as zinc stearate). In a further embodiment, the coating contains a processing aid, such as DYNAMAR EX 5912, in an amount of 0.01% by weight or 0.02% by weight to 0.05% by weight, 0.10% by weight, 0.15% by weight, 0.20% by weight, 0.25% by weight, 0.30% by weight, 0.34% by weight, or 0.35% by weight, depending on the total weight of the coating. In one embodiment, the coating contains a selected carbon black additive, an antioxidant, a stabilizer, a processing aid, and combinations thereof. In another embodiment, the coating contains a selected carbon black additive, a stabilizer, a processing aid, and combinations thereof. The optional additive may comprise two or more modalities described in this document. The coating contains (A) an ethylene-based polymer having a 121 / 12 ratio of 20 to 50; and (B) a propylene / ethylene copolymer having an Mw / Mn ratio of 2.0 to 3.5; and (C) an optional additive. The coating has a surface roughness of 0.51 micrometers (20 microinches) to 2.54 micrometers (100 microinches). In one form, the cover has a surface roughness of 0.51 micrometers (20 microinches), 0.64 micrometers (25 microinches), 0.76 micrometers (30 microinches) or 0.86 micrometers (34 microinches) to 1.40 micrometers (55 microinches), 1.52 micrometers (60 microinches), 1.78 micrometers (70 microinches), 1.90 micrometers (75 microinches), 2.03 micrometers (80 microinches), 2.16 micrometers (85 microinches), 2.18 micrometers (86 microinches), 2.26 micrometers (89 microinches), 2.29 micrometers (90 microinches), 2.41 micrometers (95 microinches) or 2.54 micrometers (100 microinches). The surface roughness of 0.51 micrometers (20 microinches)-2.54 micrometers (100 microinches) provides aesthetic and customer satisfaction. In one modality, the coating has a density of 0.919 g / cc or 0.920 g / cc to 0.942 g / cc, 0.965 g / cc or 0.975 g / cc. In one mode, the cover has a 12 of 0.5 g / 10 min, 1.0 g / 10 min, 2.0 g / 10 min, 2.2 g / 10 min, 2.4 g / 10 min or 2.5 g / 10 min to 3.0 g / 10 min, 3.2 g / 10 min, 3.3 g / 10 min or 3.5 g / 10 min. In one modality, the cover has a tensile strength (TS) of 12 MPa, 14 MPa, 15 MPa, 17 MPa or 18 MPa at MPa, 25 MPa or 30 MPa. In one modality, the cover has an aged tensile strength (after 10 days at 100 °C) of 10 MPa, 13 MPa, 14 MPa, 14.5 MPa, 15 MPa or 20 MPa to 23 MPa, 24 MPa, 25 MPa, 26 MPa or 30 MPa. In one modality, the cover has a tensile strength retention of 85%, 86%, 100%, 101% or 104% to 110%, 115% or 120%. In one modality, the cover has an elongation at break (TE) of 135%, 136%, 175%, 177%, 200%, 300%, 400%, 500% or 600% to 900%, 1000% or 2000%. In one embodiment, the cover has an aged elongation at break (after 10 days at 100 °C) of 40%, 80%, 100%, 200%, 300%, 400%, 450%, 500%, 600% or 700% to 800%, 900%, 1000%, 1500% or 2000%. In one modality, the cover has a retention of elongation at break of 30%, 40%, 45%, 50%, 70%, 80%, 85% or 100% to 108%, 110%, 115% or 120%. In one modality, the cover has an RSI of 1.0, 2.5, 2.7, 5.0, 8.0, 8.5, 9.0 or 9.4 to 15.0, 16.0, 20.0, 22.5 or 23.0. In one modality, the cover has an nRSI of 4.0, 4.2, 7.0, 9.0, 10.0, 11.0, 12.0 or 12.5 to 22.0, 22.5, 23.0, 25.0, 30.0, 33.5, 34.0 or 35.0. In one embodiment, the cover may be extruded through a die head at a pressure equal to or less than the pressure of a comparable cover lacking the (B) propylene / ethylene copolymer, under the same extrusion conditions. In other words, the pressure head of the present cover is equal to or less than the pressure head of a comparable cover lacking the (B) propylene / ethylene copolymer. The decrease in pressure head is advantageous because it allows for a higher line speed. Consequently, a decrease in pressure head indicates an improvement in line productivity. In one embodiment, the cover contains, essentially consists of, or comprises: (A) 60 wt%, 63 wt%, or 70 wt% to 75 wt%, 80 wt%, 84 wt%, 85 wt%, or 90 wt% of an ethylene-based polymer having a 121 / 12 ratio of 20, 22, or 24 to 32, 35, 40, 45, or 50; (B) 10 wt% or 15 wt% to 20 wt%, 25 wt%, or 30 wt% of a propylene / ethylene copolymer having an Mw / Mn of 2.0 or 2.4 to 3.3 or 3.5; (C) Optionally, from 0 wt. or 0.01 wt. to 1 wt., 5 wt., 6 wt., 7 wt., 10 wt., 12 wt., or 15 wt. of an additive selected from carbon black, an antioxidant, a stabilizer, a processing aid, and combinations thereof; and the coating has a surface roughness of 0.51 micrometers (20 microinches) to 2.54 micrometers (100 microinches). The coating has a surface roughness of 0.51 micrometers (20 microinches), 0.64 micrometers (25 microinches), 0.76 micrometers (30 microinches) or 0.86 micrometers (34 microinches) to 1.40 micrometers (55 microinches), 1.52 micrometers (60 microinches), 1.78 micrometers (70 microinches), 1.90 micrometers (75 microinches), 2.03 micrometers (80 microinches), 2.16 micrometers (85 microinches), 2.18 micrometers (86 microinches), 2.26 micrometers (89 microinches), 2.29 micrometers (90 microinches), 2.41 micrometers (95 microinches) or 2.54 micrometers (100 microinches); and the cover optionally has one, some or all of the following properties: (i) a density of 0.919 g / cc or 0.920 g / cc to 0.942 g / cc, 0.965 g / cc or 0.975 g / cc; (ii) a 12 of 0.5 g / 10 min, 1.0 g / 10 min, 2.0 g / 10 min, 2.2 g / 10 min, 2.4 g / 10 min or 2.5 g / 10 min to 3.0 g / 10 min, 3.2 g / 10 min, 3.3 g / 10 min or 3.5 g / 10 min; and / or (iii) a tensile strength (TS) of 12 MPa, 14 MPa, 15 MPa, 17 MPa or 18 MPa to 24 MPa, 25 MPa or 30 MPa; and / or (iv) an aged tensile strength of 10 MPa, 13 MPa, 14 MPa, 14.5 MPa, 15 MPa or 20 MPa to 23 MPa, 24 MPa, 25 MPa, 26 MPa or 30 MPa; and / or (v) a tensile strength retention of 85%, 86%, 100%, 101% or 104% to 110%, 115% or 120%; and / or (vi) an elongation at break (TE) of 135%, 136%, 175%, 177%, 200%, 300%, 400%, 500% or 600% to 900%, 1000%, 1500% or 2000%; and / or (vii) an aged elongation at break of 40%, 80%, 100%, 200%. 300%, 400%, 450%, 500%, 600% or 700% to 800%, 900%, 1000%, 1500% or 2000%; and / or (viii) a retention of elongation at break of 30%, 40%, 45%, 50%, 70%, 80%, 85% or 100% to 108%, 110%, 115% or 120%; and / or (ix) an RSI of 1.0, 2.5, 2.7, 5.0, 8.0, 8.5, 9.0 or 9.4 to 15.0, 16.0, 20.0, 22.5 or 23.0; and / or (x) an nRSI of 4.0, 4.2, 7.0, 9.0, 10.0, 11.0, 12.0 or 12.5 to 22.0, 22.5, 23.0, 25.0, 30.0, 33.5, 34.0 or 35.0. It is understood that the sum of the components in each of the covers described in this document, which includes the previous cover, results in 100% by weight. In one embodiment, the cover is a mixture of only two polymeric components: (A) the ethylene-based polymer having a 121 / 12 ratio of 20 to 50 and (B) the propylene / ethylene copolymer having an Mw / Mn of 2.0 to 3.5. It is understood that a cover mixture containing only two polymeric components may optionally include non-polymeric additives. In one modality, the cover excludes LDPE, lacks it, or substantially lacks it. In one embodiment, the cover excludes ethylene-based polymer that has a 121 / 12 ratio of more than 50, lacks it, or substantially lacks it. In one embodiment, the coating excludes gas-phase polymerization resins (GP resins), lacks them, or substantially lacks them. The shell can be formed by molten mixing. "Molten mixing" is a process in which at least two components are combined or blended together, and at least one of the components is in a molten state. Molten mixing can be achieved by batch mixing, extrusion mixing, extrusion molding, or any combination thereof. In one configuration, the coating is extruded onto the conductor. The extruder has a crosshead die, which provides the desired layer thickness (wall or coating). A non-limiting example of an extruder that can be used is a modified single-screw type with a crosshead die, continuous winding equipment, and cooling. A typical single-screw extruder can be described as having a hopper at its upper end and a die at its lower end. The hopper feeds the barrel, which contains a screw. At the lower end, between the screw end and the die, there is a filter pack and a breaker plate.The screw section of the extruder is considered to be divided into three sections: the feed section, the compression section, and the metering section, with multiple heating zones extending from the rear to the front heating zone, from top to bottom. The barrel length-to-diameter ratio ranges from 16:1 to 30:1. Fluted barrel extruders or twin-screw extruders can also be used in the core coating process. The casing extrusion process can occur at temperatures ranging from 160°C, 180°C, or 200°C to 220°C, 240°C, or 260°C. The crosshead die distributes the coating compound into a flow channel so that the molten coating compound exits at a uniform velocity and is applied to the conductor. In this way, the mixing (melt mix) and the extrusion are carried out in the same single extruder.The conductor passes through the center of the crosshead, and as it exits, a uniform layer of sheathing is applied circumferentially using pressure or semi-pressure from the tube-wound tools. One or more layers of sheathing (or other material) can be applied using a multi-crosshead. The sheathed conductor is then cooled in a water channel sufficiently to prevent deformation of the applied sheathing layer on the winder, resulting in a coated conductor. Melt mixing can occur sequentially before extrusion. Alternatively, melt mixing can occur simultaneously, or substantially simultaneously, with extrusion (i.e., melt mixing and extrusion occur in the same extruder). Carbon black can be added during melt mixing and / or during extrusion. The sheath is an outermost covering. An "outermost covering" is a layer with an outer surface that is exposed or substantially exposed to the external environment. The sheath may be the only component surrounding the conductor. Alternatively, the sheath may be the outermost layer of a multi-layered sleeve or wrapping that encloses the conductor. In one embodiment, the sheath is in direct contact with the conductor. The term "in direct contact," as used herein, refers to a sheath configuration in which the outermost sheath is immediately adjacent to the conductor, the outermost sheath touches the conductor, and no intermediate layers, intermediate sheaths, and / or intermediate structures are present between the outermost sheath and the conductor. In another configuration, the outermost sheath is in indirect contact with the conductor. The term "in indirect contact," as used herein, refers to a sheathing configuration in which an intermediate layer, intermediate cover, or intermediate structure is present between the outermost sheath and the conductor. Non-limiting examples of suitable intermediate layers, intermediate covers, and intermediate structures include insulation layers, moisture barrier layers, protective tubing, and combinations thereof. In one configuration, an insulation layer is in direct contact with the conductor, and the outermost sheath is in direct contact with the insulation layer. In other words, the sheath is in direct contact with an insulation layer surrounding the conductor. Non-limiting examples of suitable insulation layers include foam insulation layers, thermoplastic insulation layers, cross-linked insulation layers, and combinations thereof. In one embodiment, the coated conductor includes a plurality of conductors that are optical fibers, and the optical fibers are arranged in a protective tube, where the sheath surrounds the protective tube. The optical fibers may be arranged in a single protective tube or in a plurality of protective tubes. In one version, the cover has a thickness of 0.254 mm to 0.500 mm, 0.600 mm, 0.700 mm, 1.00 mm, 1.50 mm, 2.00 mm, 3.00 mm or 3.18 mm. In one embodiment, the coated conductor contains, essentially consists of, or comprises: a conductor; an outermost covering over the conductor, where the covering contains, essentially consists of or comprises: (A) 60 wt., 63 wt. or 70 wt. to 75 wt., 80 wt., 84 wt., 85 wt. or 90 wt. of an ethylene-based polymer that is an MDPE (e.g., ethylene / C4-C8 α-olefin copolymer, or furthermore an ethylene / octene copolymer) having a 121 / 12 of 20, 22 or 25 to 27, 30, 32, 35, 40, 45 or 50; wherein the MDPE has one, some or all of the following properties: (i) a density of 0.926 g / cc, 0.930 g / cc or 0.935 g / cc to 0.940 g / cc; and / or (ii) a 12 of 0.5 g / 10 min, 1.0 g / 10 min, 1.5 g / 10 min, 2.0 g / 10 min or 2.4 g / 10 min to 3.0 g / 10 min, 4.0 g / 10 min, 4.3 g / 10 min or 4.5 g / 10 min; and / or (iii) a 121 of 35 g / 10 min, 40 g / 10 min, 50 g / 10 min or 60 g / 10 min to 70 g / 10 min, 80 g / 10 min, 90 g / 10 min, 97 g / 10 min or 100 g / 10 min; and / or (iv) a 110 of 5 g / 10 min, 10 g / 10 min or 11 g / 10 min to 30 g / 10 min, 35 g / 10 min or 40 g / 10 min; and / or (v) a melting point, Tm, of 120 °C, 122 °C or 125 °C to 127 °C or 130 °C; and / or (vi) an Mw / Mn of 2.5, 2.7 or 3.0 to 3.3, 3.5 or 4.0; and / or (vii) an nRSI of 10, 15 or 19 to 83, 85 or 90; (B) 10 wt% or 15 wt% to 20 wt%, 25 wt% or 30 wt% of a propylene / ethylene copolymer having an Mw / Mn of 2.0 or 2.4 to 3.3 or 3.5; wherein the propylene / ethylene copolymer has one, some or all of the following properties: (i) una densidad de 0.880 g / cc, 0.885 g / cc o 0.887 g / cc a 0.890 g / cc, 0.891 g / cc, 0.895 g / cc, 0.900 g / cc o 0.905 g / cc; and / or (ii) a melt flow rate (MFR) of 2.0 g / 10 min, 3.0 g / 10 min or 4.0 g / 10 min to 5.0 g / 10 min, 6.0 g / 10 min, 7.0 g / 10 min, 8.0 g / 10 min, 9.0 g / 10 min, 10.0 g / 10 min, 15.0 g / 10 min, 20.0 g / 10 min or 25.0 g / 10 min; and / or (iii) less than 100 wt., 99 wt. or 98 wt. to 97 wt., 96 wt., 95 wt., 90 wt. or 85 wt. of propylene-derived units and a reciprocal amount, or more than 0 wt., 1 wt. or 2 wt. to 3 wt., 4 wt., 5 wt., 10 wt. or 15 wt. of ethylene-derived units, based on the total weight of the propylene / ethylene copolymer; and / or (iv) a total unsaturation per mole of propylene of 0.01% to 0.025% or 0.03%; and / or (v) a crystallinity of 1 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt% or 30 wt% to 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt% or 70 wt%; and / or (vi) a melting temperature, Tm, of 25 °C, 50 °C, 75 °C, 100 °C or 105 °C to 110 °C, 115 °C, 116 °C, 120 °C, 140 °C or 150 °C; and / or (vii) a weight-average molecular weight (Mw) of 20,000 g / mol, 24,000 g / mol or 30,000 g / mol to 40,000 g / mol, 48,000 g / mol or 50,000 g / mol; and / or (viii) a B-value of 0.90 or 0.94 to 0.95, 0.96, 0.97, 0.98 or 0.99; and / or (ix) sequences having an isotactic triad (mm) measured by 13C NMR of more than 0.85; and / or (x) a 12 of 0.5 g / 10 min or 0.8 g / 10 min to 3.3 g / 10 min, 3.5 g / 10 min, 5.0 g / 10 min or 10 g / 10 min; and / or (xi) an RSI of 10, 11 or 15 to 22, 25 or 30; and / or (xii) an nRSI of 15, 18 or 19 to 30, 31 or 35; and (C) 0% by weight or 0.0.1% by weight to 1% by weight, 5% by weight, 6% by weight, 7% by weight, 10% by weight, 12% by weight or 15% by weight of a selected additive of carbon black, an antioxidant, a stabilizer, a processing aid and combinations thereof; and the cover has a surface roughness of 0.76 micrometers (30 microinches), 1.27 micrometers (50 microinches), 1.52 micrometers (60 microinches), 1.78 micrometers (70 microinches), 2.03 micrometers (80 microinches) or 2.16 micrometers (85 microinches) to 2.29 micrometers (90 microinches), 2.41 micrometers (95 microinches) or 2.54 micrometers (100 microinches); and the coating optionally has one, some, or all of the following properties: (i) a density of 0.925 g / cc, 0.930 g / cc, 0.935 g / cc, 0.939 g / cc, or 0.940 g / cc to 0.941 g / cc, 0.942 g / cc, 0.946 g / cc, 0.950 g / cc, 0.960 g / cc, 0.965 g / cc, or 0.975 g / cc; and / or (ii) a 12 of 2.0 g / 10 min, 2.2 g / 10 min, 2.4 g / 10 min or 2.5 g / 10 min to 3.2 g / 10 min, 3.3 g / 10 min or 3.5 g / 10 min; and / or (iii) a tensile strength (TS) of 20 MPa or 21 MPa to 24 MPa, 25 MPa or 30 MPa; and / or (iv) an aged tensile strength of 20 MPa or 22 MPa to 23 MPa, 24 MPa, 25 MPa, 26 MPa or 30 MPa; and / or (v) a tensile strength retention of 100%, 101% or 104% to 110%, 115% or 120%; and / or (vi) an elongation at break (TE) of 135%, 136%, 175%, 177%, 200% or 300% to 600%, 900% or 1000%; and / or (vii) an aged elongation at break of 40%, 80%, 100% or 200% to 450%, 500%, 600% or 700%, 800%, 900% or 1000%; and / or (viii) a retention of elongation at break of 30% or 40% to 70%, 75%, 80%, 85%, 100% or 110%; and / or (ix) an RSI of 8.0, 8.5, 8.9, 9.0 or 9.4 to 13.0, 15.0 or 20.0; and / or (x) an nRSI of 12.0, 15.0, 16.0 or 16.8 to 20.8, 21.0, 22.0 or 25.0. In one embodiment, the coated conductor contains, essentially consists of, or comprises: a conductor; an outermost covering over the conductor, where the covering contains, essentially consists of or comprises: (A) 60 wt., 63 wt. or 70 wt. to 75 wt., 80 wt., 84 wt., 85 wt. or 90 wt. of an ethylene-based polymer that is an LLDPE (e.g., an ethylene / C4-C8 α-olefin copolymer, or furthermore an ethylene / octene copolymer or an ethylene / hexene copolymer) with a 121 / 12 ratio of 20, 22 or 24 to 30, 31, 32, 35, 40, 45 or 50; wherein the LLDPE has one, some or all of the following properties: (i) a density of 0.916 g / cc or 0.917 g / cc to 0.919 g / cc, 0.920 g / cc or 0.925 g / cc; and / or (ii) a 12 of 0.5 g / 10 min, 1.0 g / 10 min, 1.5 g / 10 min, 2.0 g / 10 min or 2.3 g / 10 min to 3.0 g / 10 min, 4.0 g / 10 min, 4.3 g / 10 min, 4.5 g / 10 min, 5 g / 10 min or 10 g / 10 min; and / or (iii) a 121 of 35 g / 10 min, 40 g / 10 min, 50 g / 10 min, g / 10 min, 70 g / 10 min or 71 g / 10 min to 80 g / 10 min, 87 g / 10 min, 90 g / 10 min or 100 g / 10 min; and / or (iv) a 110 of 5 g / 10 min, 10 g / 10 min, 15 g / 10 min or 20 g / 10 min to 25 g / 10 min, 30 g / 10 min, 35 g / 10 min or 40 g / 10 min; and / or (v) a melting point, Tm, of 120°C or 121°C to 123°C, 125°C, 127°C or 1300C; and / or (vi) an Mw / Mn of 2.5, 3.0 or 3.1 to 3.7, 4.0, 4.5 or 5.0; and / or (vii) an nRSI of 1 or 2 to 12, 15 or 20; and (B) 10 wt% or 15 wt% to 20 wt% or 30 wt% of a propylene / ethylene copolymer having an Mw / Mn of 2.0 or 2.4 to 3.3 or 3.5; wherein the propylene / ethylene copolymer has one, some or all of the following properties:(i) a density of 0.880 g / cc, 0.885 g / cc or 0.887 g / cc to 0.890 g / cc, 0.891 g / cc, 0.895 g / cc, 0.900 g / cc or 0.905 g / cc; and / or (ii) a melt flow rate (MFR) of 2.0 g / 10 min, 3.0 g / 10 min or 4.0 g / 10 min to 5.0 g / 10 min, 6.0 g / 10 min, 7.0 g / 10 min, 8.0 g / 10 min, 9.0 g / 10 min, 10.0 g / 10 min, 15.0 g / 10 min, 20.0 g / 10 min or 25.0 g / 10 min; and / or (iii) less than 100 wt., 99 wt. or 98 wt. to 97 wt., 96 wt., 95 wt., 90 wt. or 85 wt. of propylene-derived units and a reciprocal amount, or more than 0 wt., 1 wt. or 2 wt. to 3 wt., 4 wt., 5 wt., 10 wt. or 15 wt. of ethylene-derived units, based on the total weight of the propylene / ethylene copolymer; and / or (iv) a total unsaturation per mole of propylene of 0.01% to 0.025% or 0.03%; and / or (v) a crystallinity of 1 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt% or 30 wt% to 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt% or 70 wt%; and / or (vi) a melting temperature, Tm, of 25 °C, 50 °C, 75 °C, 100 °C or 105 °C to 110 °C, 115 °C, 116 °C, 120 °C. 140 °C or 150 °C; and / or (vii) a weight-average molecular weight (Mw) of 20,000 g / mol, 24,000 g / mol or 30,000 g / mol to 40,000 g / mol, 48,000 g / mol or 50,000 g / mol; and / or (viii) a B-value of 0.90 or 0.94 to 0.95, 0.96, 0.97, 0.98 or 0.99; and / or (ix) sequences having an isotactic triad (mm) measured by 13C NMR of more than 0.85; and / or (x) from 0.5 g / 10 min or 0.8 g / 10 min to 3.3 g / 10 min, 3.5 g / 10 min, 5.0 g / 10 min or 10 g / 10 min; and / or (xi) an RSI of 10, 11 or 15 to 22, 25 or 30; and / or (xii) an nRSI of 15, 18 or 19 to 30, 31 or 35; and (C) from 0 wt% or 0.01 wt% to 1 wt%, 5 wt%, 6 wt%, 7 wt%, 10 wt%, 12 wt% or 15 wt% of an additive selected from carbon black, an antioxidant, a stabilizer, a processing aid and combinations thereof; and the cover has a surface roughness of 0.76 micrometers (30 microinches) or 0.86 micrometers (34 microinches) to 1.40 micrometers (55 microinches), 1.70 micrometers (67 microinches), 1.78 micrometers (70 microinches), 1.90 micrometers (75 microinches) or 2.03 micrometers (80 microinches); and the cover has one, some or all of the following properties: (i) a density of 0.919 g / cc, 0.920 g / cc or. 0.922 g / cc to 0.925 g / cc, 0.930 g / cc, 0.933 g / cc, 0.935 g / cc or 0.940 g / cc; and / or (ii) a 12 of 2.0 g / 10 min, 2.2 g / 10 min, 2.4 g / 10 min or 2.5 g / 10 min to 2.6 g / 10 min, 3.0 g / 10 min, 3.2 g / 10 min, 3.3 g / 10 min or 3.5 g / 10 min; and / or (iii) a tensile strength (TS) of 30 MPa, 34 MPa or 35 MPa to 67 MPa, 70 MPa, 75 MPa, 80 MPa or 90 MPa; and / or (iv) an aged tensile strength of 10 MPa, 13 MPa, 13.5 MPa, 14 MPa or 15 MPa to 21 MPa, 25 MPa or 30 MPa; and / or (v) a tensile strength retention of 55%, 59%, 85%, 86% or 100% to 110% or 115%; and / or (vi) an elongation at break (TE) of 500% or 600% to 900%, 1000% or 1500%; and / or (vii) an aged elongation at break of 300%, 400%, 450% or 500% to 800%, 900%, 1000% or 1500%; and / or (viii) a retention of elongation at break of 60%, 70% or 80% to 106%, 110%, 115% or 120%; and / or (ix) an RSI of 2.5, 2.7, 4.0, 4.4, 5.0, 9.0 or 9.4 to 15.0, 20.0, 22.5, 23.0 or 25.0; and / or (x) an nRSI of 4.0, 4.2, 5.0, 7.0, 10.0, 12.0 or 12.5 to 22.0, 25.0, 30.0, 33.5, 34.0 or 35.0. In one modality, the coated conductor excludes LDPE, lacks it, or substantially lacks it. In one embodiment, the coated conductor excludes ethylene-based polymer that has a 121 / 12 ratio of more than 50, lacks it, or substantially lacks it. In one modality, 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, consumer electronics cables, a power charger cable for cell phones and / or computers, computer data cables, electrical wires, appliance wiring material, household wiring material, consumer electronics accessory cables, and any combination thereof. The present sheath containing the combination of (A) an ethylene-based polymer having a 121 / 12 ratio of 20 to 50 and (B) a propylene / ethylene copolymer having an Mw / Mn of 2.0 to 3.5 advantageously provides improved surface roughness (0.51 micrometers (20 microinches)-2.54 micrometers (100 microinches)) for outermost conductor sheaths, while improving the tensile strength and tensile elongation of the sheath. By way of example, and not as a limitation, some variations of the present description will be described in detail in the following Examples. EXAMPLES The materials used in the examples of the invention and in the comparative samples are provided in Table 1 below. Table 1 Material Composition Density (g / cc) E 1— I2 (g / 10 min) 121 (g / 10 min) 121 / 12 110 (g / 10 min) MFR (g / 10 min) Mw / Mn RSI (at 190 °C, 0.25% deformation, 25 mm plates) nRSI DOWLEX 2247G1 LLDPE ethylene / octene copolymer 0.917 123 2.38 71.18 29.9 20.88 - 3.7 3.9 6.0 Polymer A1 LLDPE ethylene / hexene copolymer 0.919 - 2.9 87 30 29.1 - 3.7 7.0 11.9 DOWLEX GM 8480 F1 LLDPE ethylene / hexene copolymer 0.917 121 3.0 74.82 24.9 22.8 - 3.1 1.5 2.6 DFH-20651 LLDPE; GP resin ethylene-based copolymer 0.920 - 0.65 49 75 9.8 - 9.4 40.4 32.6 DOWLEX 2027G1 MDPE ethylene / octene copolymer 0.940 127 4.28 96.11 22.5 29.94 - 3.0 9.5 19.7 DOWLEX 2036G1 MDPE ethylene / octene copolymer 0.935 125 2.42 60.93 27 11.58 - 3.3 1.9 82.9 DFH-3580H1 MDPE; GP resin, ethylene-based copolymer, 0.935 - 0.80, 52, 65, 23.9 - 13.3, 92.7, 82.9. VERSIFY 20001, propylene / ethylene copolymer plastomer (4.5% by weight ethylene), 0.887, 107, 0.83, 66, 79.5, 12.3, 2.0, 2.7, 21.14, 19.21 VERSIFY 30001 Propylene / ethylene copolymer plastomer (4.5% by weight of ethylene) 0.891 108 3.30 231 70 47.2 8.0 2.4 16.63 30.23 Polymer B1 Propylene / ethylene copolymer plastomer 0.898 >130 3.5 268.6 76.7 50.2 - 2.6 11.3 21.1 MOPLEN RP3232 Random copolymerpropylene / ethylene copolymer 0.900 - 3.1 215.2 69.4 39.9 8.0 3.3 15.7 27.6 PRO-FAX PD7022 Homopolymer propylene 0.900 - 13.06 - - 36.6 35 3.2 4.92 17.78 PRO-FAX RP448S2 Random copolymerpropylene / ethylene copolymer 0.900 - 17.04 - - 26.3 40 3.9 9.15 37.78 DFNA0037BK1 carbon black masterbatch 1.21 - - - - - - - - - DYNAMAR FX59123 processing aid 1.93 - - - - - - - - - IRGANOX 10354 antioxidant additive 1.072 - - - - - - - - - NAUGARD Super Q5 stabilizer (CAS 26780-96-1) 1.09 - - - - - - - - -. Available through The Dow Chemical Company, available through 3M, available through Chemtura, available through LyondellBasell, available through BASF The carbon black stock mix (DFNA-0037BK), processing aid (DYNAMAR FX 5912), antioxidant additive (IRGANOX 1035), and stabilizer (NAUGARD Super Q) are dry-mixed with LLDPE or MDPE pellets to form powder-coated ethylene-based polymer pellets. The powder-coated ethylene-based polymer pellets and the propylene-based polymer are blended in a Brabender extruder equipped with a Maddock mixing screw under the conditions specified in Table A below. The mixture is fed through a strand die at the extruder end. After exiting the extruder, the strands are fed through a Berlyn pelletizer to form coating composition pellets. Table A. Brabender extruder conditions Heat Zone 1 = 180 °C Screw RPM = 60 Heat Zone 2 = 200 °C Line Speed ​​= 15.24 m (50 ft) / min Heat Zone 3 = 220 °C Melt Temperature = 231 °C Heat Zone 4 = 210 °C Single Strand Die Size = 0.145 Screw = Maddock Mixing Screw Breaker Plate Pressure = 200-300 PSI The coated conductors are prepared by extrusion by adding the coating composition pellets to a mini-wire line extruder. The extrusion conditions are provided below in Table B. This equipment is used to generate samples with a final diameter of approximately 21.84 mm (0.86 in.) and a coating thickness of approximately 0.254 mm (0.01 in.) on a solid copper conductor of US Wire Gauge (AWG) 14 (diameter 1.63 mm / 0.064 in.). Table B. Mini-wire line extrusion conditions Brabender Heat zones 1-4 = 210 °C Screw RPM = 50 Line speed = 15.24 m / min Melting temperature = 218 °C Die size = 0.20 cm (0.08 in) Pipe tip size = 0.17 cm (0.067 in) Finished diameter = 0.21 cm (0.082 in) Cooling water temperature = 35-40 °C Cover thickness = 0.03 cm (0.01 inch) Screw = 1.91 cm (¾ inch) diameter; 25:1, L:D General purpose polyethylene extruder without mixing section Qualitative softness is determined visually. In Table 2, a qualitative smoothness rating of "+" indicates a smooth wire surface, and a qualitative smoothness rating of "++" indicates a very smooth wire surface. A qualitative smoothness rating of "--" indicates a rough wire surface. The properties for the comparative samples and examples of the invention of covers are provided in Table 2 below. Table c\i MC = comparative sample NM = not measured The present description advantageously extends the range of suitable base resins to form a conductor covering having a surface roughness of 0.51 micrometers (20 microinches)-2.54 micrometers (100 microinches). Ethylene-based polymers with a 121 / 12 ratio greater than 50 are known to exhibit excellent processability; that is, polyethylene can be extruded at high line speeds with excellent surface roughness (MC 1 and MC 2). Conversely, ethylene-based polymers with a 121 / 12 ratio less than 50 exhibit a viscosity profile that, comparatively, lacks both melt strength and shear fluidization behavior (MC 3, MC 12). For example, Table 2 shows that a comparative cover (MC 3) containing (A) an LLDPE having a 121 / 12 ratio of 20-50 (DOWLEX 2247G, 121 / 12 of 31) but lacking a (B) propylene / ethylene copolymer having an Mw / Mn of 2.0-3.5 exhibits an unacceptably high surface roughness of 5.01 micrometers (197.4 microinches).Additionally, Table 2 shows that a comparative cover (MC 12) containing (A) an MDPE having a 121 / 12 ratio of 20-50 (DOWLEX 2036G, 121 / 12 of 27) but lacking a (B) propylene / ethylene copolymer having an Mw / Mn of 2.0-3.5 exhibits an unacceptably high surface roughness of. 12.18 micrometers (479.7 microinches). Therefore, ethylene-based polymers with a 121 / 12 ratio of less than 50 have limited extrusion performance and generally result in a conductor sleeve with poor surface roughness (i.e., a surface roughness greater than 2.54 micrometers (100 microinches)). The applicant unexpectedly discovered that a cover containing the combination of (A) an ethylene-based polymer having a 121 / 12 ratio of 20-50 and (B) a propylene / ethylene copolymer having an Mw / Mn of 2.0-3.5 advantageously achieves a surface roughness of 0.51 micrometers (20 microinches)-2.54 micrometers (100 microinches), which is comparable to covers containing an ethylene-based polymer having a 121 / 12 ratio of more than 50 (e.g., a GP resin) and having no propylene / ethylene copolymer (MC 1, MC 2, and MC 15). The applicant unexpectedly discovered that a cover containing the combination of (A) an ethylene-based polymer having a 121 / 12 ratio of 20-50 and (B) a propylene / ethylene copolymer having an Mw / Mn of 2.0-3.5 advantageously achieves a surface roughness of 0.51 micrometers (20 microinches)-2.54 micrometers (100 microinches), which is comparable to a cover containing (A) an ethylene-based polymer having a 121 / 12 ratio of 20-50; and (B) (i) a propylene / ethylene copolymer having an Mw / Mn of more than 3.5 (MC 11) or (B) (ii) a propylene homopolymer having an Mw / Mn of 2.0-3.5 but lacking an ethylene comonomer (MC 10). The applicant unexpectedly discovered that a sheath containing the combination of (A) an ethylene-based polymer having a 121 / 12 ratio of 20-50 and (B) a propylene / ethylene copolymer having an Mw / Mn of 2.0-3.5 advantageously achieves a surface roughness of 0.51 micrometers (20 microinches)-2.54 micrometers (100 microinches), while maintaining the sheath's 12 and tensile properties suitable for coated conductor applications. Specifically, the applicant unexpectedly discovered that adding a (B) propylene / ethylene copolymer having an Mw / Mn ratio of 2.0–3.5 to (A) LLDPE having a 121 / 12 ratio of 20–50 (DOWLEX 2247G, 121 / 12 of 31) advantageously reduces the jacket surface roughness to 0.51 micrometers (20 microinches)–2.54 micrometers (100 microinches), while maintaining the jacket's 12 and tensile properties suitable for coated conductor applications. Figure 1 is a graph showing the impact of the amount of propylene / ethylene copolymer (VERSIFY 3000) in an LLDPE-containing jacket (DOWLEX 2247G) on the jacket surface roughness. Furthermore, the applicant unexpectedly discovered that adding a (B) propylene / ethylene copolymer having an Mw / Mn ratio of 2.0–3.5 to (A) MDPE having a 121 / 12 ratio of 20–50 (DOWLEX 2036G, 121 / 12 of 27) advantageously reduces the jacket surface roughness to 0.51 micrometers (20 microinches)–2.54 micrometers (100 microinches), while maintaining the jacket's 12 and tensile properties suitable for coated conductor applications. Figure 2 is a graph showing the impact of the amount of propylene / ethylene copolymer (VERSIFY 3000) in a jacket containing MDPE (DOWLEX 2036G) on the jacket surface roughness. The improved surface roughness after the addition of (B) propylene / ethylene copolymer having an Mw / Mn of 2.0-3.5 is unexpected; that is, the surface roughness is not a linear function of the content of the (B) propylene / ethylene copolymer having an Mw / Mn of 2.0-3.5, as shown by the data in Table 2 and Figures 1 and 2. Furthermore, the composition of the invention, in general, shows improved mechanical properties in the range of the proposed cover compositions. It is specifically intended that the present description not be limited to the forms and illustrations contained herein, but include modified forms of the forms that include parts of the forms and combinations of elements of different forms that are within the scope of the following claims. It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

CLAIMS 1. A coated conductor characterized in that it comprises: a conductor; an outer covering over the conductor, wherein the covering comprises: (A) an ethylene-based polymer having a 121 / 12 ratio of 20 to 50; (B) a propylene / ethylene copolymer having an Mw / Mn of 2.0 to 3.5; and wherein the covering has a surface roughness of 0.51 micrometers (20 microinches) to 2.54 micrometers (100 microinches).

2. The coated conductor according to claim 1, characterized in that the (A) ethylene-based polymer is an ethylene / α-olefin copolymer.

3. The coated conductor according to claim 1 or 2, characterized in that the (A) ethylene-based polymer is selected from the group consisting of linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and combinations thereof.

4. The coated conductor according to any of claims 1-3, characterized in that the (B) propylene / ethylene copolymer has a melting temperature, Tm, of 25 °C to 120 °C.

5. The coated conductor according to any of claims 1-4, characterized in that the (B) propylene / ethylene copolymer contains from 1% by weight to 15% by weight of ethylene-derived units, depending on the total weight of the propylene / ethylene copolymer.

6. The coated conductor according to any of claims 1-5, characterized in that the (B) propylene / ethylene copolymer has a density of 0.880 g / cc to 0.905 g / cc.

7. The coated conductor according to any of claims 1-6, characterized in that the (B) propylene / ethylene copolymer has a normalized relaxation spectrum index (nRSI) of 15 to 35.

8. The coated conductor according to any of claims 1-7, characterized in that the coating comprises: (A) from 60 wt% to 90 wt% of the ethylene-based polymer; (B) from 10 wt% to 30 wt% of the propylene / ethylene copolymer; and (C) optionally, from more than 0 wt% to 15 wt% of an additive.

9. The coated conductor according to claim 8, characterized in that it comprises the additive, wherein the additive is selected from the group consisting of carbon black, antioxidant, stabilizer, processing aid and combinations thereof.

10. The coated conductor according to any of claims 1-9, characterized in that the coating comprises: (A) from 60 wt% to 90 wt% of the ethylene-based polymer that is an MDPE; (B) from 10 wt% to 30 wt% of the propylene / ethylene copolymer; (C) optionally, from more than 0 wt% to 15 wt% of an additive; and wherein the coating has a surface roughness of 0.76 micrometers (30 microinches) to 2.54 micrometers (100 microinches) and a 12 of 2.0 g / 10 min to 3.5 g / 10 min.

11. The coated conductor according to any of claims 1-9, characterized in that the coating comprises: (A) from 60 wt% to 90 wt% of the ethylene-based polymer that is an LLDPE; (B) from 10 wt% to 30 wt% of the propylene / ethylene copolymer; (C) optionally, from more than 0 wt% to 15 wt% of an additive; and wherein the coating has a surface roughness of 0.76 micrometers (30 microinches) to 2.03 micrometers (80 microinches) and a 12 of 2.0 g / 10 min to 3.5 g / 10 min.

12. The coated conductor according to any of claims 1-11, characterized in that the coating consists of: (A) the ethylene-based polymer; (B) the propylene / ethylene copolymer; and (C) optionally, an additive selected from the group consisting of carbon black, antioxidants, colorants, ultraviolet (UV) absorbers or stabilizers, antiblocking agents, flame retardants, compatibilizers, plasticizers, fillers, processing aids, and combinations thereof.

13. The conductor covered in accordance with any of claims 1-12, characterized in that the covering is in direct contact with the conductor.

14. The conductor covered in accordance with any of claims 1-12, characterized in that an insulation layer is in direct contact with the conductor and the sheath is in direct contact with the insulation layer.