Colorable polymer composition exhibiting enhanced aging characteristics

Abstract

A polymer composition comprising: a first ethylene-based polymer having a density of 0.941 g / cc to 0.970 g / cc as measured according to ASTM D792; a second ethylene-based polymer having a density of 0.860 g / cc to 0.930 g / cc as measured according to ASTM D792; and an additive selected from the group consisting of an antioxidant, a hindered amine light stabilizer, and combinations thereof. The polymer composition has a total comonomer content of 2.9 wt% or greater based on the total weight of the polymer composition.

Description

BACKGROUND TECHNICAL FIELD

[0002] The present disclosure relates generally to polymeric compositions, and more particularly to colorable polymeric compositions exhibiting enhanced aging characteristics.

[0003] ABSTRACT

[0004] Polymeric compositions are used to form a jacket as the outermost layer on power and telecommunication cables. The jacket helps to protect the cable from physical damage that it can be subjected to during installation and / or use. The jacket can be colored to help visually distinguish one cable from another. Cables have a useful life of many years and are subjected to various conditions during use. Therefore, the polymeric composition forming the jacket must meet certain mechanical properties after being subjected to accelerated aging to ensure proper useful life. For example, the jacket is often subjected to accelerated ultraviolet (“UV”) light aging as well as accelerated heat aging to replicate weathering and extended use life. A polymeric composition exhibiting 75% retention of the tensile elongation at break and 600% tensile elongation at break after 2000 hours of accelerated UV light aging (i.e., “UV aged” condition) can pass the more stringent standard group of ASTM D1248-16 and IEC 60811-401-2017 applicable to cable jackets. Similarly, a polymeric composition exhibiting 75% retention of the tensile elongation at break and 600% tensile elongation at break after 240 hours at 100°C (i.e., “heat aged” condition) will pass the industry standard for heat aging, GB / T2951.12-2008.

[0005] During exposure to UV light and environmental conditions, free radicals and acids are generated within the polymeric composition. The free radicals oxidize the chains of the polymeric composition, causing the mechanical properties of the jacket to decrease as UV exposure increases. The oxidation of the chains also forms acids within the jacket. A conventional method to mitigate the effects of free radicals in outdoor or high UV light exposure environments is to include both carbon black and hindered amine light stabilizers (“HALS”). Carbon black, while effective at absorbing ultraviolet light and preventing free radical generation, has a strong negative impact on the ability to impart the desired color to the jacket. In addition to carbon black, HALS are also used in polymeric jackets to neutralize the generated free radicals. HALS are effective at neutralizing free radicals, but are deactivated by the acids present in the polymeric jacket environment. Therefore, attempts to make colorable cables by exclusively using HALS would result in accelerated mechanical property degradation due to more free radical generation and HALS deactivation by the acids.

[0006] As noted above, in addition to accelerating UV light aging, the polymer composition used for the jacket is also exposed to accelerated heat aging. Traditional methods of improving the heat aging performance of a polymer composition include the use of antioxidants and heat stabilizers such as phenolic antioxidants. However, designing a high density polyethylene composition (i.e., a composition having a density of 0.930 g / cc or greater) with good heat aging continues to pose a challenge.

[0007] In view of the above, it has been unexpectedly discovered that a polymer composition can form a jacketable and colorable jacket that exhibits 75% retained break tensile elongation and 600% break tensile elongation after 2000 hours of accelerated UV light aging or 240 hours of heat aging at 100°C. SUMMARY

[0008] The present invention provides a polymer composition useful as a cable jacket that is colorable and exhibits 75% retained break tensile elongation and 600% break tensile elongation after 2000 hours of accelerated UV light aging or 240 hours of heat aging at 100°C.

[0009] The present invention is the result of discovering that using a polymer blend produces a polymer composition having a total comonomer content of 2.9% or greater that can exhibit the above-mentioned properties. It has been surprisingly discovered that the total comonomer content of the polymer composition affects the retained break tensile elongation and tensile strength after accelerated UV aging. This result is surprising because it represents a parameter that heretofore has not been recognized to affect the UV resistance of a polymer composition independent of conventional UV resistance additives. It has also been surprisingly discovered that the total comonomer content affects the retained break tensile elongation and tensile strength after accelerated heat aging. This result is surprising because increased comonomer content is associated with decreased crystallinity and density; the opposite approach conventionally used to improve the heat aging performance of a polymer composition.

[0010] The present invention is particularly useful for cable jackets.

[0011] According to a first feature of the present disclosure, a polymer composition comprises: a first ethylene-based polymer having a density of 0.941 g / cc to 0.970 g / cc as measured according to ASTM D792; a second ethylene-based polymer having a density of 0.860 g / cc to 0.930 g / cc as measured according to ASTM D792; and an additive selected from the group consisting of antioxidants, hindered amine light stabilizers, and combinations thereof, wherein the polymer composition has a total comonomer content of 2.9 wt% or greater based on the total weight of the polymer composition.

[0012] According to a second feature of the present disclosure, the polymer composition comprises 40 wt% to 95 wt% of the first ethylene-based polymer, based on the total weight of the polymer composition.

[0013] According to a third feature of the present disclosure, the polymer composition comprises 5 wt% to 60 wt% of the second ethylene-based polymer, based on the total weight of the polymer composition.

[0014] According to a fourth feature of the present disclosure, the polymer composition is free of carbon black.

[0015] According to a fifth feature of the present disclosure, the polymer composition has a density of 0.945 g / cc or less, as measured according to ASTM D792.

[0016] According to a sixth feature of the present disclosure, the polymer composition exhibits a tensile elongation at break of 600% or more in a UV aged state, as measured according to ASTM D638.

[0017] According to a seventh feature of the present disclosure, the polymer composition has a density of 0.930 g / cc to 0.945 g / cc, as measured according to ASTM D792.

[0018] According to an eighth feature of the present disclosure, the second ethylene-based polymer has a density of 0.918 g / cc to 0.930 g / cc, as measured according to ASTM D792.

[0019] According to a ninth feature of the present disclosure, the polymer composition exhibits a tensile elongation at break of 600% or more after aging at 100°C for 240 hours, as measured according to ASTM D638.

[0020] According to a tenth feature of the present disclosure, a coated conductor comprises a conductor and a polymer composition disposed about the conductor. DETAILED DESCRIPTION

[0021] As used herein, the term “and / or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and / or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

[0022] All ranges are inclusive unless otherwise specified.

[0023] Test methods refer to the most recent test methods as of the priority date of this document, unless the date is expressed as a two-digit hyphenated test method number. Reference to a test method includes reference to both the testing association and the test method number. Test method organizations are referenced by one of the following abbreviations: ASTM refers to ASTM International (formerly the American Society for Testing and Materials); IEC refers to the International Electrotechnical Commission; EN refers to European Standard; DIN refers to the German Institute for Standardization; and ISO refers to the International Organization for Standardization.

[0024] As used herein, unless otherwise indicated, the term weight percent ("wt%") refers to the weight percent of a component based on the total weight of the polymer composition.

[0025] Melt index (I2) values ​​herein refer to values ​​determined according to ASTM method D1238 at 190 degrees Celsius (°C) and a 2.16 kilogram (Kg) mass and are provided in units of grams eluted per ten minutes ("g / 10 min").

[0026] Density values ​​herein refer to values ​​determined at 23°C according to ASTM D792 and are provided in grams per cubic centimeter ("g / cc").

[0027] As used herein, a Chemical Abstracts Services Registry Number ("CAS#") means the unique numerical identifier most recently assigned to a chemical compound by Chemical Abstracts Services as of the priority date of this document.

[0028] Polymer composition

[0029] The polymer composition of the present invention comprises a first vinyl polymer, a second vinyl polymer, and an additive selected from the group consisting of an antioxidant, a hindered amine light stabilizer, and combinations thereof.

[0030] First ethylene-based polymer

[0031] As noted above, one component of the polymer composition is a first ethylene-based polymer. As used herein, an "ethylene-based" polymer is a polymer in which greater than 40 wt% of the monomers are ethylene, although other comonomers can also be used. "Polymer" means a macromolecular compound composed of a plurality of similar or different types of monomers bonded together, and includes homopolymers and interpolymers. "Interpolymer" means a polymer that comprises at least two different monomer types that are bonded together. Interpolymers include copolymers (typically used to refer to polymers prepared from two different monomer types) and polymers prepared from more than two different monomer types (e.g., terpolymers (three different monomer types) and tetrapolymers (four different monomer types)). The ethylene-based polymer can be an ethylene homopolymer. As used herein, "homopolymer" denotes a polymer comprising repeat units derived from a single monomer type, but does not exclude residual amounts of other components used in the preparation of the homopolymer such as catalysts, initiators, solvents, and chain transfer agents.

[0032] The ethylene-based polymer can have a unimodal or multimodal molecular weight distribution and can be used alone or in combination with one or more other types of ethylene-based polymers (e.g., a blend of two or more ethylene-based polymers that differ from one another in monomer composition and content, catalytic preparation method, molecular weight, molecular weight distribution, density, etc.). If a blend of ethylene-based polymers is employed, the polymers can be blended by any in-reactor or post-reactor method.

[0033] The vinyl polymer may comprise 40 mol% or more, or 45 mol% or more, or 50 mol% or more, or 60 mol% or more, or 70 mol% or more, or 80 mol% or more, or 85 mol% or more, or 90 mol% or more, or 91 mol% or more, or 92 mol% or more, or 93 mol% or more, or 94 mol% or more, or 95 mol% or more, or 96 mol% or more, or 97 mol% or more, or 97.5 mol% or more, or 98 mol% or more, as measured using C13 nuclear magnetic resonance ("NMR") as explained in more detail below. 1 mol% or more, or 99 mol% or more, while 100 mol% or less, or 99.5 mol% or less, or 99 mol% or less, or 98 mol% or less, or 97 mol% or less, or 96 mol% or less, or 95 mol% or less, or 94 mol% or less, or 93 mol% or less, or 92 mol% or less, or 91 mol% or less, or 90 mol% or less, or 85 mol% or less, or 80 mol% or less, or 70 mol% or less, or 60 mol% or less, or 50 mol% or less, or 45 mol% or less of ethylene. Other units or comonomers of the ethylene-based polymer may include C3 alpha-olefins, or C4 alpha-olefins, or C6 alpha-olefins, or C8 alpha-olefins, or C 10 α-olefins, or C 12 α-olefins, or C 16 α-olefins, or C 18 α-olefins, or C 20 α-Olefins such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene.

[0034] The first ethylene-based polymer can have a comonomer content of 0 wt% or more, or 0.5 wt% or more, or 1.0 wt% or more, or 1.5 wt% or more, or 2.0 wt% or more, or 2.5 wt% or more, or 3.0 wt% or more, or 3.5 wt% or more, or 4.0 wt% or more, or 4.5 wt% or more, or 5.0 wt% or more, or 5.5 wt% or more, or 6.0 wt% or more, or 6.5 wt% or more, or 7.0 wt% or more, or 7.5 wt% or more, or 8.0 wt% or more, or 8.5 wt% or more, or 9.0 wt% or more, or 9.5 wt% or more, and 10.0 wt% or less, or 9.5 wt% or less, or 9.0 wt% or less, or 8.5 wt% or less, or 8.0 wt% or less, or 7.5 wt% or less, or 7.0 wt% or less, or 6.5 wt% or less, or 6.0 wt% or less, or 5.5 wt% or less, or 5.0 wt% or less, or 4.5 wt% or less, or 4.0 wt% or less, or 3.5 wt% or less, or 3.0 wt% or less, or 2.5 wt% or less, or 2.0 wt% or less, or 1.5 wt% or less, or 1.0 wt% or less, or 0.5 wt% or less, based on the total weight of the first ethylene-based polymer, as measured according to NMR. The comonomer content is the total weight percent of all comonomers present in the first ethylene-based polymer, based on the weight of the first ethylene-based polymer.

[0035] The polymer composition of claim 1, wherein the polymer composition comprises 40 wt% to 95 wt% of the first ethylene-based polymer, based on the total weight of the polymer composition. For example, the polymer composition can comprise 40 wt% or more, or 45 wt% or more, or 50 wt% or more, or 55 wt% or more, or 60 wt% or more, or 65 wt% or more, or 70 wt% or more, or 75 wt% or more, or 80 wt% or more, or 85 wt% or more, or 90 wt% or more, and 95 wt% or less, or 90 wt% or less, or 85 wt% or less, or 80 wt% or less, or 75 wt% or less, or 70 wt% or less, or 65 wt% or less, or 60 wt% or less, or 55 wt% or less, or 50 wt% or less, or 45 wt% or less of the first ethylene-based polymer, based on the total weight of the polymer composition.

[0036] The first ethylene-based polymer can have a density of 0.941 g / cc to 0.970 g / cc, as measured according to ASTM D792. For example, the first ethylene-based polymer can have a density of 0.941 g / cc or more, or 0.945 g / cc or more, or 0.950 g / cc or more, or 0.955 g / cc or more, or 0.960 g / cc or more, or 0.965 g / cc or more, while 0.970 g / cc or less, or 0.965 g / cc or less, or 0.960 g / cc or less, or 0.955 g / cc or less, or 0.950 g / cc or less, or 0.945 g / cc or less, as measured according to ASTM D792.

[0037] Second ethylene-based polymer

[0038] The polymer composition also includes a second ethylene-based polymer. The description of the ethylene-based polymer provided in connection with the first ethylene-based polymer applies to the second ethylene-based polymer.

[0039] The polymer composition includes 5 wt% to 60 wt% of the second ethylene-based polymer, based on the total weight of the polymer composition. For example, the polymer composition can include 5 wt% or more, or 10 wt% or more, or 15 wt% or more, or 20 wt% or more, or 25 wt% or more, or 30 wt% or more, or 35 wt% or more, or 40 wt% or more, or 45 wt% or more, or 50 wt% or more, or 55 wt% or more, while 60 wt% or less, or 55 wt% or less, or 50 wt% or less, or 45 wt% or less, or 40 wt% or less, or 35 wt% or less, or 30 wt% or less, or 25 wt% or less, or 20 wt% or less, or 15 wt% or less, or 10 wt% or less of the second ethylene-based polymer, based on the total weight of the polymer composition.

[0040] The second ethylene-based polymer can have a density of 0.860 g / cc to 0.930 g / cc, as measured according to ASTM D792. For example, the first ethylene-based polymer can have a density of 0.860 g / cc or more, or 0.865 g / cc or more, or 0.870 g / cc or more, or 0.875 g / cc or more, or 0.880 g / cc or more, or 0.885 g / cc or more, or 0.890 g / cc or more, or 0.895 g / cc or more, or 0.900 g / cc or more, or 0.905 g / cc or more, or 0.910 g / cc or more, or 0.915 g / cc or more, or 0.918 g / cc or more, or 0.920 g / cc or more, or 0.922 g / cc or more, or 0.924 g / cc or more, or 0.926 g / cc or more, or 0.928 g / cc or more, while 0.930 g / cc or less, or 0.928 g / cc or less, or 0.926 g / cc or less, or 0.924 g / cc or less, or 0.922 g / cc or less, or 0.920 g / cc or less, or 0.915 g / cc or less, or 0.910 g / cc or less, or 0.905 g / cc or less, or 0.900 g / cc or less, or 0.895 g / cc or less, or 0.890 g / cc or less, or 0.885 g / cc or less, or 0.880 g / cc or less, or 0.875 g / cc or less, or 0.870 g / cc or less, or 0.865 g / cc or less, as measured according to ASTM D792.

[0041] The second ethylene-based polymer can have a comonomer content of 0 wt% or more, or 0.5 wt% or more, or 1.0 wt% or more, or 1.5 wt% or more, or 2.0 wt% or more, or 2.5 wt% or more, or 3.0 wt% or more, or 3.5 wt% or more, or 4.0 wt% or more, or 4.5 wt% or more, or 5.0 wt% or more, or 5.5 wt% or more, or 6.0 wt% or more, or 6.5 wt% or more, or 7.0 wt% or more, or 7.5 wt% or more, or 8.0 wt% or more, or 8.5 wt% or more, or 9.0 wt% or more, or 9.5 wt% or more, or 10.0 wt% or more, or 10.5 wt% or more, or 11.0 wt% or more, or 11.5 wt% or more, or 12.0 wt% or more, or 12.5 wt% or more, or 13.0 wt% or more, or 13.5 wt% or more, or 14.0 wt% or more, or 14.5 wt% or more, or 15.0 wt% or more, or 15.5 wt% or more, or 16.0 wt% or more, or 16.5 wt% or more, or 17.0 wt% or more, or 17.5 wt% or more, or 18.0 wt% or more, or 18.5 wt% or more, or 19.0 wt% or more, or 19.5 wt% or more, 20.0 wt% or more, or 20.5 wt% or more, or 21.0 wt% or more, or 21.5 wt% or more, or 22.0 wt% or more, or 22.5 wt% or more, or 23.0 wt% or more, or 23.5 wt% or more, or 24.0 wt% or more, or 24.5 wt% or more, or 25.0 wt% or more, or 25.5 wt% or more, or 26.0 wt% or more, or 26.5 wt% or more, or 27.0 wt% or more, or 27.5 wt% or more, or 28.0 wt% or more, or 28.5 wt% or more, or 29.0 wt% or more, or 29.5 wt% or more, or 30.0 wt% or more, or 40.0 wt% or more, or 50.0 wt% or more, or 55.0 wt% or more, while 60.0 wt% or less, or 55.0 wt% or less, or 50.0 wt% or less, or 40.0 wt% or less, or 30.0 wt% or less, or 29.5 wt% or less, or 29.0 wt% or less, or 28.5 wt% or less, or 28.0 wt% or less, or 27.5 wt% or less, or 27.0 wt% or less, or 26.5 wt% or less, or 26.0 wt% or less, or 25.5 wt% or less, or 25.0 wt% or less, or 24.5 wt% or less, or 24.0 wt% or less, or 23.5 wt.% or less, or 23.0 wt.% or less, or 22.5 wt.% or less, or 22.0 wt.% or less, or 21.5 wt.% or less, or 21.0 wt.% or less, or 20.5 wt.% or less, 20.0 wt.% or less, or 19.5 wt.% or less, or 19.0 wt.% or less, or 18.5 wt.% or less, or 18.0 wt.% or less, or 17.5 wt.% or less, or 17.0 wt.% or less, or 16.5 wt.% or less, or 16.0 wt.% or less, or 15.5 wt.% or less, or 15.0 wt.% or less, or 14.5 wt.% or less, or 14.0 wt.% or less, or 13.5 wt.% or less, or 13.0 wt.% or less, or 12.5 wt.% or less, or 12.0 wt.% or less, or 11.5 wt.% or less, or 11.0 wt.% or less, or 10.5 wt.% or less, 10.0 wt.% or less, or 9.5 wt.% or less, or 9.0 wt.% or less, or 8.5 wt.% or less, or 8.0 wt.% or less, or 7.5 wt.% or less, or 7.0 wt.% or less, or 6.5 wt.% or less, or 6.0 wt.% or less, or 5.5 wt.% or less, or 5.0 wt.% or less, or 4.5 wt.% or less, or 4.0 wt.% or less, or 3.5 wt.% or less, or 3.0 wt.% or less, or 2.5 wt.% or less, or 2.0 wt.% or less, or 1.5 wt.% or less, or 1.0 wt.% or less, or 0.5 wt.% or less. The comonomer content is the total weight percent of all comonomers present in the second ethylene-based polymer, based on the weight of the second ethylene-based polymer.

[0042] Total comonomer content

[0043] As described above, it has been surprisingly discovered that the mechanical properties of the polymer composition after UV aging and heat aging depend on the total comonomer content of the polymer composition. Specifically, the polymer composition can achieve UV aging and heat aging standards when the polymer composition has a total comonomer content of 2.9 wt% or greater, based on the total weight of the polymer composition. The total comonomer content of the polymer composition can be 2.9 wt% or more, or 3.0 wt% or more, or 3.2 wt% or more, or 3.4 wt% or more, or 3.6 wt% or more, or 3.8 wt% or more, or 4.0 wt% or more, or 4.2 wt% or more, or 4.4 wt% or more, or 4.6 wt% or more, or 4.8 wt% or more, or 5.0 wt% or more, or 5.2 wt% or more, or 5.4 wt% or more, or 5.6 wt% or more, or 5.8 wt% or more, or 6.0 wt% or more, or 7.0 wt% or more, or 8.0 wt% or more, or 9.0 wt% or more, or 10.0 wt% or more, based on the total weight of the polymer composition. The NMR method for measuring total comonomer content is provided in the Examples section.

[0044] Additives

[0045] The polymer composition can include additional additives in the form of antioxidants, crosslinking co-agents, hindered amine light stabilizers (“HALS”), cure accelerators and scorch retardants, processing aids, coupling agents, ultraviolet stabilizers (including UV absorbers), antistatic agents, additional nucleating agents, slip agents, lubricants, viscosity control agents, tackifiers, anti-blocking agents, surfactants, extender oils, acid scavengers, flame retardants, and metal deactivators.

[0046] The polymer composition can include 0.01 wt% to 10 wt% of each additive. For example, the polymer composition can include 0.1 wt% or more, or 0.2 wt% or more, or 0.3 wt% or more, or 0.4 wt% or more, or 0.5 wt% or more, or 0.6 wt% or more, or 0.7 wt% or more, or 0.8 wt% or more, or 0.9 wt% or more, or 1.0 wt% or more, or 2.0 wt% or more, or 3.0 wt% or more, or 4.0 wt% or more, or 5.0 wt% or more, or 6.0 wt% or more, or 7.0 wt% or more, or 8.0 wt% or more, or 9.0 wt% or more, while 10.0 wt% or less, or 9.0 wt% or less, or 8.0 wt% or less, or 7.0 wt% or less, or 6.0 wt% or less, or 5.0 wt% or less, or 4.0 wt% or less, or 3.0 wt% or less, or 2.0 wt% or less, or 1.0 wt% or less, or 0.9 wt% or less, or 0.8 wt% or less, or 0.7 wt% or less, or 0.6 wt% or less, or 0.5 wt% or less, or 0.4 wt% or less, or 0.3 wt% or less, or 0.2 wt% or less of each of these additives.

[0047] HALS are chemical compounds containing amine functionality that are used as stabilizers in plastics and polymers. These compounds can be derivatives of tetramethylpiperidine and are primarily used to protect polymers from free radical oxidation due to exposure to UV light. HALS can include one or more of: poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinylethanol-alt-1,4- butanediol acid) (CAS# 65447-77-0); bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (CAS# 52829-07-9); di-(1,2,2,6,6-pentamethyl-4-piperidinyl)-2-butyl-2-(3,5-di-tert-butyl-4- hydroxybenzyl)malonate (CAS# 63843-89-0); bis(1-octyloxy-2,2,6,6-tetramethyl-4- piperidinyl) sebacate (CAS# 129757-67-1); poly[[6-[(1,1,3,3-tetramethylbutyl)amino]- s-triazine-2,4-diyl]-[(2,2,6,6-tetramethyl-4-piperidinyl)imino]-hexamethylene-[(2,2,6,6- tetramethyl-4-piperidinyl)imino] (CAS# 71878-19-8); 1,3,5-triazine-2,4,6-triamine, N,N'-1,2- ethanediylbis[N-[3-[[4,6-bis[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5- triazin-2-yl]amino]propyl]-N',N"-dibutyl-N',N"-bis(1,2,2,6,6-pentamethyl-4- piperidinyl)-(CAS# 106990-43-6); 1,6-hexanediamine, N,N'-bis(2,2,6,6-tetramethyl-4- piperidinyl)-, polymer with 2,4,6-trichloro-1,3,5-triazine, reaction product with N-butyl-1- butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine (CAS# 192268-64-7). Examples of HALS can be available under the trade names TINUVIN TM 622 and CHIMASSORB TM 944 are commercially available from BASF, Ludwigshafen, Germany. Other UV stabilizers include, for example, UVASORB TM HA10 and HA88 (both commercially available from 3V Sigma USA), CHIMASSORB TM 944LD (commercially available from BASF) and THT 4801, THT 7001, and THT 6460 (each commercially available from Solvay Corp.).

[0048] The polymer composition can be free of carbon black. As used herein, the term“free of” is defined to mean that the formulation includes less than 0.5 wt.%, based on the total weight of the polymer composition, of carbon black. As highlighted above, carbon black is effective at absorbing ultraviolet light and preventing the generation of free radicals, but has a strong influence on the ability to impart the desired color to the polymer composition.

[0049] The polymer composition can include a colorant. As explained above, the absence of carbon black enables the polymer composition to be colored by a colorant. The colorant can include one or more of an azo dye, an anthraquinone dye, and a phthalocyanine dye. The polymer composition can include one or more of the following: COLOUR INDEX TM generic colorants such as Pigment Violet 32 (CAS# 12225-08-0), Pigment Orange 34 (CAS# 15793-73-4), Pigment Red 38 (CAS# 6358-87-8), Pigment Red 208 (CAS# 31778-10-6), Pigment Red 48:2 (CAS# 7023-61-2), Pigment Red 57:1 (CAS# 5281-04-9), Pigment Yellow 155 (CAS# 68516-73-4 / 77465-46-4), Pigment Yellow 151 (CAS# 31837-42-0), Pigment Green 7 (CAS# 1328-53-6), Pigment Red 122 (CAS# 980-26-7 / 16043-40-6), Pigment Red 214 (CAS# 40618-31-3), Pigment Violet 23 (CAS# 6358-30-1), and / or Pigment Yellow 191 (CAS# 129423-54-7).

[0050] The polymer composition can include one or more particulate fillers, such as glass fibers or various mineral fillers (including nanocomposites). Fillers, particularly those having elongated or platelet-shaped particles that provide a higher aspect ratio (length / thickness), can improve modulus and post-extrusion shrinkage properties. The median size or d50 of the filler can be less than 20 pm, less than 10 pm, or less than 5 pm. The fillers can be surface treated to promote wetting or dispersion in the polymer composition. Specific examples of suitable fillers include, but are not limited to, titanium dioxide, zinc oxide, calcium carbonate, silica, quartz, fused quartz, talc, mica, clay, kaolin, wollastonite, feldspar, aluminum hydroxide, and graphite. The fillers can be included in the polymer composition in an amount ranging from 2 wt.% to 30 wt.% or 5 wt.% to 30 wt.%, based on the total weight of the polymer composition.

[0051] Processing aids can include metal salts of fluororesins such as polytetrafluoroethylene or fluorinated ethylene propylene; carboxylic acids such as zinc stearate, calcium stearate, and the like; fatty acids such as stearic acid, oleic acid, or erucic acid; fatty amides such as stearamide, oleamide, erucamide, or N,N'-ethylene bis stearamide; polyethylene waxes; oxidized polyethylene waxes; polymers of ethylene oxide; copolymers of ethylene oxide and propylene oxide; vegetable waxes; petroleum waxes; non-ionic surfactants; silicone fluids and polysiloxanes.

[0052] Antioxidants can include hindered phenols such as tetrakis[methylene(3,5-di-tert-butyl-4- hydroxyhydrocinnamate)]methane; bis[(beta-(3,5-di-tert-butyl-4-hydroxybenzyl)methylcarbinol)]- sulfide, 4,4'-thiobis(2-methyl-6-tert-butylphenol), 4,4'-thiobis(2-tert-butyl-5-methylphenol), 2,2'- thiobis(4-methyl-6-tert-butylphenol), and thiodiethylene bis(3,5-di-tert-butyl-4-hydroxy)- hydrocinnamate; phosphites and phosphonites such as tris(2,4-di-tert-butylphenyl)phosphite and di-tert-butylphenyl-phosphite; thio compounds such as dilaurylthiodipropionate, dimyristylthiodipropionate, and distearylthiodipropionate; various siloxanes; polymeric 2,2,4-trimethyl-1,2- dihydroquinoline, n,n'-bis(1,4-dimethylpentyl-p-phenylenediamine), alkylated diphenylamine, 4,4'- bis(alpha,alpha-dimethylbenzyl) diphenylamine, diphenyl-p-phenylenediamine, mixed diaryl-p- phenylenediamines, and other hindered amine anti-degradants or stabilizers.

[0053] Compounding

[0054] The components of the polymer composition can be added to a batch or continuous mixer for melt blending. The components can be added in any order or one or more masterbatches can be first prepared for blending with the other components. Melt blending can be carried out at a temperature above the highest melting polymer. The melt blended composition can then be conveyed to an extruder or injection molding machine, or shaped through a die into the desired article, or converted into pellets, tape, strips, or films or some other form for storage or preparation of material for feeding to the next shaping or processing step. Optionally, if shaped into pellets or some similar configuration, the pellets or the like can be coated with an anti-sticking agent to facilitate handling during storage.

[0055] Examples of compounding equipment that can be used include internal batch mixers, continuous single or twin screw mixers, or kneading continuous extruders. The type of mixer utilized as well as the operating conditions of the mixer will affect the properties of the composition such as viscosity, volume resistivity, and surface smoothness of extrusion.

[0056] Mechanical properties

[0057] The polymer composition can exhibit an unaged (i.e., in a state that has not been aged), UV aged, and / or heat aged maximum tensile strength of 20.0 megapascals (MPa) to 45.0 MPa, as measured according to ASTM D638. For example, the polymer composition can exhibit an unaged, UV aged, and / or heat aged maximum tensile strength of 20.0 MPa or greater, or 20.5 MPa or greater, or 21.0 MPa or greater, or 21.5 MPa or greater, or 22.0 MPa or greater, or 22.5 MPa or greater, or 23.0 MPa or greater, or 23.5 MPa or greater, or 24.0 MPa or greater, or 24.5 MPa or greater, or 25.0 MPa or greater, or 25.5 MPa or greater, or 26.0 MPa or greater, or 26.5 MPa or greater, or 27.0 MPa or greater, or 27.5 MPa or greater, or 28.0 MPa or greater, or 28.5 MPa or greater, or 29.0 MPa or greater, or 29.5 MPa or greater, or 30.0 MPa or greater, or 30.5 MPa or greater, or 31.0 MPa or greater, or 31.5 MPa or greater, or 32.0 MPa or greater, or 32.5 MPa or greater, or 33.0 MPa or greater, or 33.5 MPa or greater, or 34.0 MPa or greater, or 34.5 MPa or greater, or 35.0 MPa or greater, or 35.5 MPa or greater, or 36.0 MPa or greater, or 36.5 MPa or greater, or 37.0 MPa or greater, or 37.5 MPa or greater, or 38.0 MPa or greater, or 38.5 MPa or greater, or 39.0 MPa or greater, or 39.5 MPa or greater, or 40.0 MPa or greater, or 40.5 MPa or greater, or 41.0 MPa or greater, or 41.5 MPa or greater, or 42.0 MPa or greater, or 42.5 MPa or greater, or 43.0 MPa or greater, or 43.5 MPa or greater, or 44.0 MPa or greater, or 44.5 MPa or greater, while 45.0 MPa or less, or 44.5 MPa or less, or 44.0 MPa or less, or 43.5 MPa or less, or 43.0 MPa or less, or 42.5 MPa or less, or 42.0 MPa or less, or 41.5 MPa or less, or 41.0 MPa or less, or 40.5 MPa or less, or 40.0 MPa or less, or 39.5 MPa or less, or 39.0 MPa or less, or 38.5 MPa or less, or 38.0 MPa or less, or 37.5 MPa or less, or 37.0 MPa or less, or 36.5 MPa or less, or 36.0 MPa or less, or 35.5 MPa or less, or 35.0 MPa or less, or 34.5 MPa or less, or 34.0 MPa or less, or 33.5 MPa or less, or 33.0 MPa or less, or 32.0 MPa or less, as measured according to ASTM D638.5 MPa or less, or 32.0 MPa or less, or 31.5 MPa or less, or 31.0 MPa or less, or 30.5 MPa or less, or 30.0 MPa or less, or 29.5 MPa or less, or 29.0 MPa or less, or 28.5 MPa or less, or 28.0 MPa or less, or 27.5 MPa or less, or 27.0 MPa or less, or 26.5 MPa or less, or 26.0 MPa or less, or 25.5 MPa or less, or 25.0 MPa or less, or 24.5 MPa or less, or 24.0 MPa or less, or 23.5 MPa or less, or 23.0 MPa or less, or 22.5 MPa or less, or 22.0 MPa or less, or 21.5 MPa or less, or 21.0 MPa or less, or 20.5 MPa or less.

[0058] The polymer composition can exhibit an unaged, UV aged, or heat aged elongation at break of 600% to 1200% as measured according to ASTM D638. For example, the polymer composition can exhibit an unaged, UV aged, or heat aged elongation at break of 600% or more, or 610% or more, or 620% or more, or 630% or more, or 640% or more, or 650% or more, or 660% or more, or 670% or more, or 680% or more, or 690% or more, or 700% or more, or 710% or more, or 720% or more, or 730% or more, or 740% or more, or 750% or more, or 760% or more, or 770% or more, or 780% or more, or 790% or more, or 800% or more, or 810% or more, or 820% or more, or 830% or more, or 840% or more, or 850% or more, or 860% or more, or 870% or more, or 880% or more, or 890% or more, or 900% or more, or 910% or more, or 920% or more, or 930% or more, or 940% or more, or 950% or more, or 960% or more, or 970% or more, or 980% or more, or 990% or more, or 1000% or more, or 1010% or more, or 1020% or more, or 1030% or more, or 1040% or more, or 1050% or more, or 1060% or more, or 1070% or more, or 1080% or more, or 1090% or more, or 1100% or more, or 1110% or more, or 1120% or more, or 1130% or more, or 1140% or more, or 1150% or more, or 1160% or more, or 1170% or more, or 1180% or more, or 1190% or more,Simultaneously, an elongation at break of 1200% or less, or 1190% or less, or 1180% or less, or 1170% or less, or 1160% or less, or 1150% or less, or 1140% or less, or 1130% or less, or 1120% or less, or 1110% or less, or 1100% or less, or 1090% or less, or 1080% or less, or 1070% or less, or 1060% or less, or 1050% or less, or 1040% or less, or 1030% or less, or 1020% or less, or 1010% or less, or 1000% or less, or 990% or less, or 980% or less, or 970% or less, or 960% or less, or 950% or less, or 940% or less, or 930% or less, or 920% or less, or 910% or less, or 900% or less, or 890% or less, or 880% or less, or 870% or less, or 860% or less, or 850% or less, or 840% or less, or 830% or less, or 820% or less, or 810% or less, or 800% or less, or 790% or less, or 780% or less, or 770% or less, or 760% or less, or 750% or less, or 740% or less, or 730% or less, or 720% or less, or 710% or less, or 700% or less, or 690% or less, or 680% or less, or 670% or less, or 660% or less, or 650% or less, or 640% or less, or 630% or less, or 620% or less, or 610% or less.

[0059] The polymer composition can have a retention of maximum tensile strength and / or retention of elongation at break (both measured by dividing the UV aged or heat aged value by the unaged value) of 65% or more, or 70% or more, or 75% or more, or 80% or more, or 85% or more, or 90% or more, or 95% or more, or 100% or more, or 105% or more, or 110% or more, or 115% or more, and simultaneously 120% or less, or 115% or less, or 110% or less, or 105% or less, or 100% or less, or 95% or less, or 90% or less, or 85% or less, or 80% or less, or 75% or less, or 70% or less.

[0060] Coated conductor

[0061] The present disclosure also provides a coated conductor. The coated conductor includes a conductor and a coating on the conductor, the coating including a polymer composition. The polymer composition is disposed at least partially around the conductor to produce the coated conductor. The conductor can include an electrically conductive metal or an optically transparent structure.

[0062] The method for making a coated conductor includes mixing and heating a polymer composition in an extruder to at least the melting temperature of the polymer components to form a polymer melt blend, and then coating the polymer melt blend onto a conductor. The term "onto" includes direct contact or indirect contact between the polymer melt blend and the conductor. The polymer melt blend is in an extrudable state.

[0063] The polymer composition is disposed on and / or around the conductor to form a coating. The coating can be one or more inner layers, such as an insulating layer. The coating can completely or partially cover or otherwise surround or encase the conductor. The coating can be the only component that surrounds the conductor. Alternatively, the coating can be one layer of a multi-layered sheath or jacket that encases the conductor. The coating can directly contact the conductor. The coating can directly contact an insulating layer that surrounds the conductor.

[0064] Examples

[0065] Materials

[0066] The following materials were employed in the following examples.

[0067] HDPE1 is an ethylene / hexene copolymer having a density of 0.946 g / cc, a melt index of 0.95 g / 10 min, and a hexene comonomer content of 2.28 wt% based on the weight of HDPE1 as measured according to NMR. HDPE1 is commercially available from Dow Chemical Company, Midland, MI.

[0068] LLDPE1 is a linear low density polyethylene having a density of 0.926 g / cc and a melt index of 0.93 g / 10 min and having a butene comonomer content of 7.5 wt% as measured according to NMR. LLDPE1 is available from Dow Chemical Company, Midland, MI.

[0069] HDPE2 is an ethylene homopolymer having a density of 0.961 g / cc and a melt index of 0.80 g / 10 min, and is available from Dow Chemical Company, Midland, MI.

[0070] LLDPE2 is a linear low density polyethylene having a density of 0.919 g / cc, a melt index of 0.90 g / 10 min, and a hexene comonomer content of 8.27 wt% based on the total weight of LLDPE2 as measured according to NMR. LLDPE2 is commercially available from Dow Chemical Company, Midland, MI.

[0071] AO is a sterically hindered phenolic antioxidant with the chemical name tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) pentaerythritol and is commercially available as I RGANOX 1010 TM UVA is an ultraviolet light absorber with the chemical composition 2-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)-4-methylphenol (CAS No. 3896-11-5) and is commercially available as TINUVIN® 329 from BASF Corporation, Ludwigshafen, Germany.

[0072] UVA is an ultraviolet light absorber with the chemical composition 2-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)-4-methylphenol (CAS No. 3896-11-5) and is commercially available as TINUVIN® 329 from BASF Corporation, Ludwigshafen, Germany. TM 326UVA is an ultraviolet light absorber with the chemical composition 2-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)-4-methylphenol (CAS No. 3896-11-5) and is commercially available as TINUVIN® 329 from BASF Corporation, Ludwigshafen, Germany.

[0073] HALS is a mixture of 50 wt.% poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-s-triazine-2,4-diyl]- [(2,2,6,6-tetramethyl-4-piperidyl)imino]-hexamethylene-[(2,2,6,6-tetramethyl-4- piperidyl)imino] (CAS No. 71878-19-8) and 50 wt.% poly(4-hydroxy-2,2,6,6-tetramethyl-1 - piperidineethanol-alt-1,4-butanediol) (CAS No. 65447-77-0) and is commercially available as TINUVIN™ 783 from BASF Corporation, Ludwigshafen, Germany.

[0074] PA is a fluoro-resin processing aid commercially available under the trade designation DYNAMAR™ FX 5912 from 3M, Saint Paul, Minnesota, USA.

[0075] Sample preparation

[0076] Samples were prepared by compounding HDPE and LLDPE in a BRABENDER® mixer at 150 °C. The rotor speed of the mixer was set to 30 revolutions per minute (“RPM”). The components other than the HDPE and LLDPE were fed into the mixer. The rotor speed was increased to 80 RPM and the sample was mixed for an additional 5 minutes. The sample was then cooled and cut into small pieces. TM Samples were prepared by compounding HDPE and LLDPE in a BRABENDER® mixer at 150 °C. The rotor speed of the mixer was set to 30 revolutions per minute (“RPM”). The components other than the HDPE and LLDPE were fed into the mixer. The rotor speed was increased to 80 RPM and the sample was mixed for an additional 5 minutes. The sample was then cooled and cut into small pieces.

[0077] Forty grams of the small piece was sandwiched between two biaxially oriented polyethylene terephthalate (i.e., Mylar) sheets and placed in a mold having dimensions of 100 millimeters ("mm") x 200 mm x 2 mm. The mold was placed in a KT-201-A hot press from Shanghai Great Instrument Co. Ltd and preheated at 170° C. for 10 minutes. The mold was vented 8 times. The mold was then maintained at 170° C. and 10 MPa (as measured by the hot press) for an additional 5 minutes. The mold was then cooled to room temperature within 5 minutes at 10 MPa using internal water cooling to form a plaque. The plaque was cut into 5A dog bones according to ISO 527-2.

[0078] UV Aged Samples: As used herein, UV aged samples were prepared by subjecting a 5A dog bone to a UV aging protocol. The UV aging protocol consisted of placing a 5A dog bone selected for accelerated UV aging following ASTM D1248-16 in a QUV accelerated weathering tester from Q-Lab with SOLAREYE TM Irradiance control and water spray. Aging conditions are to use UVA-340 fluorescent lamp at 340nm 0.70W / (m 2 The UV aging was performed for 2000 hours including the dark condensation period.

[0079] Heat aged samples: Heat aged samples were produced according to GB / T 2951.12-2008 by placing five dog bones from each example into an oven at 100° C. for 240 hours.

[0080] Test methods

[0081] Nuclear Magnetic Resonance: Use 13 The total comonomer content of the sample was determined by C NMR. NMR was performed by dissolving the sample in trichloroethane-d4 ("TCE-d4") at 120°C to form a homogeneous solution. 13 Bruker AVANCE operating at C resonance frequency TM All NMR data were acquired on a 400 MHz spectrometer using a 10 mm BBO probe. Chemical shifts are given in ppm (parts per million) relative to TCE-d4. 13The pulse program for C NMR, where the observed pulse is 90 degrees. The recycle delay is set to 6 seconds. The sample is scanned 4000 times. The comonomer content of each vinyl polymer is determined according to the same procedure described above.

[0082] Results

[0083] Table 1 provides the composition of Comparative Examples (“CE”) 1-3 and Inventive Examples (“IE”) 1-9. Table 2 provides the unaged, heat aged, and UV aged mechanical properties, such as maximum tensile strength (“TS Max”), tensile elongation at break (“TE”), maximum tensile strength retention (“TS Retention”), and tensile elongation at break retention (“TE Retention”) of CE 1-3 and IE 1-9.

[0084]

[0085]

[0086] With respect to Tables 1 and 2, it can be seen that increasing the total comonomer content of the examples generally increases the tensile elongation at break and the tensile elongation at break retention of the UV aged and heat aged samples before reaching a total comonomer content of 2.9 wt%. After reaching a total comonomer content of 2.9 wt%, the samples exhibit a retained tensile elongation at break of 75% or greater and a tensile elongation at break of 600% or greater, indicating that the samples can pass the more stringent standards set by ASTM D1248-16 and IEC 60811-401-2017 for cable jacketing. As noted above, it is surprising that the UV aged and heat aged mechanical properties of the polymer compositions exhibit a dependence on the total comonomer content, and that a critical value of a total comonomer content of 2.9 wt% and greater is able to exhibit the desired properties. It is further surprising that IE 1-9 all have a density of 0.930 g / cc or greater, but still exhibit greater mechanical property retention in the UV aged and heat aged states than CE 1-3.

Claims

1. A polymer composition comprising: a first ethylene-based polymer having a density of 0.941 g / cc to 0.970 g / cc as measured according to ASTM D792; a second ethylene-based polymer having a density of 0.860 g / cc to 0.930 g / cc as measured according to ASTM D792 and a comonomer content of 6.5 wt% or more based on the total weight of the second ethylene-based polymer as measured by NMR; and additives selected from the group consisting of antioxidants, hindered amine light stabilizers, and combinations thereof, wherein the polymer composition has a total comonomer content of 2.9 wt% or greater, based on the total weight of the polymer composition.

2. The polymer composition of claim 1, wherein the polymer composition comprises 40 to 95 weight percent of the first vinyl polymer, based on the total weight of the polymer composition.

3. The polymer composition of claim 2, wherein the polymer composition comprises 5 to 60 wt% of the second vinyl polymer, based on the total weight of the polymer composition.

4. The polymer composition of claim 3, wherein the polymer composition does not contain carbon black.

5. The polymer composition of any one of claims 1 to 4, wherein the polymer composition has a density of 0.945 g / cc or less as measured according to ASTM D792.

6. The polymer composition of claim 5, wherein the polymer composition exhibits a tensile elongation at break of 600% or greater in a UV aged state as measured according to ASTM D638.

7. The polymer composition of any one of claims 1 to 4, wherein the polymer composition has a density of 0.930 g / cc to 0.945 g / cc as measured according to ASTM D792.

8. The polymer composition of claim 7, wherein the second ethylene-based polymer has a density of 0.918 g / cc to 0.930 g / cc as measured according to ASTM D792.

9. The polymer composition of claim 8, wherein the polymer composition exhibits a tensile elongation at break of 600% or greater after aging at 100°C for 240 hours as measured according to ASTM D638.

10. A coated conductor, comprising: conductors; and The polymer composition according to any one of claims 1 to 9, wherein the polymer composition is disposed around the conductor.

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