Colorable polymer compositions exhibiting improved aging properties

Abstract

The polymeric composition includes a first ethylene-based polymer having a density from 0.941 g / cc to 0.970 g / cc as measured in accordance with ASTM D792, a second ethylene-based polymer having a density from 0.860 g / cc to 0.930 g / cc as measured in accordance with ASTM D792, and an additive selected from the group consisting of antioxidants, hindered amine light stabilizers, and combinations thereof. The polymeric composition has a total comonomer content of greater than, or equal to, 2.9 weight percent, based on the total weight of the polymeric composition.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to polymer compositions, and more particularly to colorable polymer compositions that exhibit improved aging properties. [Background technology]

[0002] Introduction Polymer compositions are used to form jackets as the outermost layer on power and communication cables. The jackets help protect the cables from physical damage that they may endure during installation and / or use. Jackets are sometimes colored to make them visually distinguishable from other cables. Cables have long service lives and are subject to a variety of conditions during use. Therefore, the polymer compositions forming the jackets must meet certain mechanical properties after accelerated aging to ensure adequate service life. For example, jackets are often subjected to accelerated ultraviolet ("UV") light aging and accelerated heat aging to replicate weather resistance and long life. A polymer composition that exhibits 75% retained tensile elongation at break and 600% tensile elongation at break after 2000 hours of accelerated UV light aging (i.e., "UV aged" conditions) is likely to pass the more stringent standard sets that apply to cable jackets: ASTM D1248-16 and IEC 60811-401-2017. Similarly, a polymer composition that exhibits a retained tensile elongation at break of 75% and a tensile elongation at break of 600% after 240 hours at 100°C (i.e., the "heat aged" condition) passes the industry standard GB / T2951.12-2008 for heat aging.

[0003] Free radicals and acids are generated within the polymer composition during exposure to UV light and environmental conditions. The free radicals oxidize the polymer composition's chains, resulting in a deterioration of the jacket's mechanical properties with increasing UV exposure. Chain oxidation also forms acids within the jacket. A conventional approach to mitigating 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 is effective at absorbing UV light and preventing the generation of free radicals, but it has a strong negative impact on the jacket's ability to impart a desired color. In addition to carbon black, HALS are utilized in the polymer jacket to neutralize the generated free radicals. While HALS are effective at neutralizing free radicals, they are deactivated by acids present in the polymer jacket environment. Thus, attempts to create colorable cables using only HALS result in accelerated degradation of mechanical properties due to the generation of more free radicals and the deactivation of HALS by acids.

[0004] As explained above, the polymer compositions used in jackets are exposed to accelerated heat aging in addition to accelerated UV aging. Conventional approaches to improving the heat aging performance of polymer compositions include the use of antioxidants, such as phenolic antioxidants and heat stabilizers. However, designing high-density polyethylene compositions (i.e., compositions having a density of 0.930 g / cc or greater) with good heat aging continues to pose challenges.

[0005] In view of the above, it would be unexpected to discover a polymer composition capable of forming a jacket that is both colorable and capable of exhibiting 75% retained tensile elongation at break and 600% tensile elongation at break after 2000 hours of accelerated UV light aging or 240 hours of heat aging at 100°C. Summary of the Invention

[0006] The present invention provides a polymer composition useful as a cable jacket that is colorable and can exhibit 75% retained tensile elongation at break and 600% tensile elongation at break after 2000 hours of accelerated UV light aging or 240 hours of heat aging at 100°C.

[0007] The present invention is the result of the discovery that polymer compositions can exhibit the above-mentioned properties using a blend of polymers resulting in a polymer composition having a total comonomer content of 2.9 wt% or greater. Surprisingly, it has been discovered that the total comonomer content of a polymer composition affects the retained tensile elongation at break and tensile strength after accelerated UV aging. This result is surprising because it represents a previously unrecognized parameter that affects the UV resistance of a polymer composition independently of traditional UV-resistant additives. It has also been surprisingly discovered that the total comonomer content affects the retained tensile elongation at break 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 traditionally used to enhance heat aging performance in polymer compositions.

[0008] The present invention is particularly useful for cable jackets.

[0009] According to a first aspect of the present disclosure, a polymer composition includes: a first ethylene-based polymer having a density from 0.941 g / cc to 0.970 g / cc, as measured in accordance with ASTM D792; a second ethylene-based polymer having a density from 0.860 g / cc to 0.930 g / cc, as measured in accordance with ASTM D792; and an additive selected from the group consisting of an antioxidant, a hindered amine light stabilizer, and combinations thereof, wherein the polymer composition has a total comonomer content of 2.9 wt.% or greater, based on a total weight of the polymer composition.

[0010] According to a second aspect of the present disclosure, the polymer composition comprises 40% to 95% by weight of a first ethylene-based polymer, based on the total weight of the polymer composition.

[0011] According to a third aspect of the present disclosure, the polymer composition comprises 5% to 60% by weight of a second ethylene-based polymer, based on the total weight of the polymer composition.

[0012] According to a fourth aspect of the present disclosure, the polymer composition is free of carbon black.

[0013] According to a fifth feature of the present disclosure, the polymer composition has a density of less than or equal to 0.945 g / cc as measured in accordance with ASTM D792.

[0014] According to a sixth feature of the present disclosure, the polymer composition exhibits a tensile elongation at break of 600% or greater in a UV aged condition as measured according to ASTM D638.

[0015] 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.

[0016] 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 in accordance with ASTM D792.

[0017] According to a ninth feature of the present disclosure, the polymer composition exhibits a tensile elongation at break of greater than or equal to 600% as measured according to ASTM D638 after aging at 100°C for 240 hours.

[0018] According to a tenth feature of the present disclosure, a coated conductor includes a conductor and a polymer composition disposed around the conductor. DETAILED DESCRIPTION OF THE INVENTION

[0019] As used herein, the term "and / or," when used with a list of two or more items, means that any one of the listed items can be used by itself, or any combination of two or more of the listed items can be used. 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.

[0020] Unless otherwise stated, all ranges are inclusive of the endpoints.

[0021] Test methods refer to the most current test method as of the priority date of this document unless the test method number indicates a date with a two-digit number with a hyphen. References to test methods include both a reference to the testing organization and the test method number. Test method organizations are referred to 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 Norm, DIN refers to the Deutsches Institut fur Normung, and ISO refers to the International Organization for Standards.

[0022] As used herein, the term weight percent ("wt. %") refers to the weight percentage that a component represents of the total weight of the polymer composition, unless otherwise specified.

[0023] As used herein, melt index (I2) values refer to values determined according to ASTM method D1238 at 190 degrees Celsius (°C) using a mass of 2.16 kilograms (Kg) and are provided in units of grams dissolved per 10 minutes ("g / 10 min").

[0024] Density values herein refer to values determined in accordance with ASTM D792 at 23° C. and are provided in units of grams per cubic centimeter ("g / cc").

[0025] As used herein, Chemical Abstract Services Registry Number ("CAS#") refers to the unique numeric identifier last assigned to a chemical compound by the Chemical Abstract Service as of the priority date of this document.

[0026] polymer composition The polymer composition of the present invention includes a first ethylene-based polymer, a second ethylene-based polymer, and an additive selected from the group consisting of an antioxidant, a hindered amine light stabilizer, and combinations thereof.

[0027] First ethylene-based polymer As described 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% by weight of the monomers are ethylene, although other comonomers may be used. "Polymer" refers to a polymeric compound containing multiple monomers of the same or different types bonded together, including homopolymers and interpolymers. "Interpolymer" refers to a polymer containing at least two different monomer types bonded together. Interpolymers include copolymers (usually used to refer to polymers prepared from two different monomer types) and polymers prepared from three or more different monomer types (e.g., terpolymers (three different monomer types) and quaterpolymers (four different monomer types)). The ethylene-based polymer may be an ethylene homopolymer. As used herein, "homopolymer" refers to a polymer containing repeat units derived from a single monomer type, but does not exclude residual amounts of other components used in preparing the homopolymer, such as catalysts, initiators, solvents, and chain transfer agents.

[0028] The ethylene-based polymer can have a unimodal or polymodal 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 differing in monomer composition and content, catalyst preparation, molecular weight, molecular weight distribution, density, etc.) When a blend of ethylene-based polymers is used, the polymers can be blended by any in-reactor or post-reactor process.

[0029] The ethylene-based polymer has a C13 content of 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 described in more detail below. The ethylene-based polymer may contain 1% or more, or 99 mol% or more, while simultaneously containing 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 in the ethylene-based polymer may include C3 or C4, or C6, or C8, or C9, or C10, or C11, or C12, or C13, or C14, or C15, or C16, or C17, or C18, or C19, or C20, or C21, or C22, or C23, or C24, or C25, or C26, or C27, or C28, or C29, or C21, or C22, or C23, or C24, or C25, or C26, or C28, or C29, or C29, or C30, or C31, or C32, or C33, or C34, or C35, or C36, or C37, or C38, or C39, or C41, or C42, or C43, or C44, or C45, or C46, or C48, or C49, or C50, or C51, or C52, or C53, or C54, or C55, 10 , or C 12 , or C 16 , or C 18 , or C 20 Alpha-olefins such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene can be mentioned.

[0030] The comonomer content of the first ethylene-based polymer is 0 wt.% or greater, or 0.5 wt.% or greater, or 1.0 wt.% or greater, or 1.5 wt.% or greater, or 2.0 wt.% or greater, or 2.5 wt.% or greater, or 3.0 wt.% or greater, or 3.5 wt.% or greater, or 4.0 wt.% or greater, or 4.5 wt.% or greater, or 5.0 wt.% or greater, or 5.5 wt.% or greater, or 6.0 wt.% or greater, or 6.5 wt.% or greater, or 7.0 wt.% or greater, or 7.5 wt.% or greater, or 8.0 wt.% or greater, or 8.5 wt.% or greater, or 9.0 wt.% or greater, based on the total weight of the first ethylene-based polymer as measured according to NMR. Comonomer content may be 10.0 wt% or less, or 9.5 wt% or more, 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. Comonomer content is the total weight % of all comonomers present in the first ethylene-based polymer, based on the weight of the first ethylene-based polymer.

[0031] 2. The polymer composition of claim 1, wherein the polymer composition comprises 40% to 95% by weight of the first ethylene-based polymer, based on the total weight of the polymer composition. For example, the polymer composition may comprise 40% or more, or 45% or more, or 50% or more, or 55% or more, or 60% or more, or 65% or more, or 70% or more, or 75% or more, or 80% or more, or 85% or more, or 90% or more by weight, while simultaneously comprising 95% or less, or 90% or less, or 85% or less, or 80% or less, or 75% or less, or 70% or less, or 65% or less, or 60% or less, or 55% or less, or 50% or less, or 45% or less by weight of the first ethylene-based polymer, based on the total weight of the polymer composition.

[0032] The first ethylene-based polymer may have a density from 0.941 g / cc to 0.970 g / cc, as measured in accordance with ASTM D 792. For example, the first ethylene-based polymer may have a density of 0.941 g / cc or greater, or 0.945 g / cc or greater, or 0.950 g / cc or greater, or 0.955 g / cc or greater, or 0.960 g / cc or greater, or 0.965 g / cc or greater, while simultaneously having a density of 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 in accordance with ASTM D 792.

[0033] Second ethylene-based polymer The polymer composition also includes a second ethylene-based polymer. The ethylene-based polymer descriptions provided in connection with the first ethylene-based polymer apply to the second ethylene-based polymer.

[0034] The polymer composition comprises 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 may comprise 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 simultaneously comprising 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, based on the total weight of the polymer composition.

[0035] The second ethylene-based polymer may have a density of from 0.860 g / cc to 0.930 g / cc as measured in accordance with ASTM D792. 2The ethylene-based polymers have a viscosity 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, as measured in accordance with ASTM D792. / cc or more, while simultaneously having a density of 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.

[0036] the comonomer content of the second ethylene-based polymer is 0 wt.% or greater, or 0.5 wt.% or greater, or 1.0 wt.% or greater, or 1.5 wt.% or greater, or 2.0 wt.% or greater, or 2.5 wt.% or greater, or 3.0 wt.% or greater, or 3.5 wt.% or greater, or 4.0 wt.% or greater, or 4.5 wt.% or greater, or 5.0 wt.% or greater, or 5.5 wt.% or greater, or 6.0 wt.% or greater, or 6.5 wt.% or greater, or 7.0 wt.% or greater, or 7.5 wt.% or greater, or 8.0 wt.% or greater, or 8.5 wt.% or greater, based on the total weight of the second ethylene-based polymer, as measured according to NMR; or 9.0% by weight or more, or 9.5% by weight or more, or 10.0% by weight or more, or 10.5% by weight or more, or 11.0% by weight or more, or 11.5% by weight or more, or 12.0% by weight or more, or 12.5% by weight or more, or 13.0% by weight or more, or 13.5% by weight or more, or 14.0% by weight or more, or 14.5% by weight or more, or 15.0% by weight or more, or 15.5% by weight or more, or 16.0% by weight or more, or 16.5% by weight or more, or 17.0% by weight or more, or 17.5% by weight or more, or 18.0% by weight or more, or 18.5% by weight or more, or 19.0% by weight or more, or 19.5% by weight or more, or 20.0% by weight or more, or 20.5% by weight or more, or 21.0% by weight or more, or 21.5% by weight or more, or 22.0% by weight or more, or 22.5% by weight or more, or 23.0% by weight or more, or 23.5% by weight or more, or 24.0% by weight or more, or 24.5% by weight or more, or 25.0% by weight or more, or 25.5% by weight or more, or 26.0% by weight or more, or 26.5% by weight or more, or 27.0% by weight or more, or 27.5% by weight or more, or 28.0% by weight or more, or 28.5% by weight or more, or 29.0% by weight or more, or 29.5% by weight or more, or 30.0% by weight or more, or 40.0% by weight or more, or 50.0% by weight or more, or 55.0% by weight or more, while simultaneously 60.0% by weight or less, or 55.0% by weight or less, or 50.0% by weight or less, or 40.0% by weight or less, or 30.0% by weight or less, or 29.5% by weight or less, or 29.0% by weight or less, or 28.5% by weight or less, or 28.0% by weight or less, or 27.5% by weight or less, or 27.0% by weight or less, or 26.5% by weight or less, or 26.0% by weight or less, or 25.5% by weight or less, or 25.0% by weight or less, or 24.5% by weight or less, or 24.0% by weight or less, or 23.5% by weight or less, or 23.0% by weight or less, or 22.5% by weight or less, or 22.0% by weight or less, or 21.5% by weight or less, or 21.0% by weight or less, or 20.5% by weight or less, 20.0% by weight or less, or 19.5% by weight or less, or 19.0% by weight or less, or 18.5% by weight or less, or 18.0% by weight or less, or 17.5% by weight or less, or 17.0% by weight or less, or 16.5% by weight or less, or 16.0% by weight or less, or 15.5% by weight or less, or 15.0% by weight or less, or 14.5% by weight or less, or 14.0% by weight or less, or 13.5% by weight or less, or 13.0% by weight or less, or 12.5% by weight or less % 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, or 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. 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.

[0037] Total Comonomer Content As explained above, it has been surprisingly discovered that the mechanical properties of a polymer composition after UV aging and heat aging depend on the total comonomer content of the polymer composition. Specifically, when the polymer composition has a total comonomer content of 2.9 wt% or more based on the total weight of the polymer composition, the polymer composition may achieve the UV aging and heat aging criteria. The total comonomer content of the polymer composition may 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. An NMR method for measuring total comonomer content is provided in the Examples section.

[0038] additives The polymeric compositions may contain additional additives in the form of antioxidants, crosslinking coagents, hindered amine light stabilizers ("HALS"), cure accelerators and scorch inhibitors, processing aids, coupling agents, ultraviolet light stabilizers (including UV absorbers), antistatic agents, additional nucleating agents, slip agents, lubricants, viscosity modifiers, tackifiers, antiblocking agents, surfactants, extender oils, acid scavengers, flame retardants, and metal deactivators.

[0039] The polymer composition may contain 0.01% to 10% by weight of each additive. For example, the polymer composition may contain 0.1% by weight or more, or 0.2% by weight or more, or 0.3% by weight or more, or 0.4% by weight or more, or 0.5% by weight or more, or 0.6% by weight or more, or 0.7% by weight or more, or 0.8% by weight or more, or 0.9% by weight or more, or 1.0% by weight or more, or 2.0% by weight or more, or 3.0% by weight or more, or 4.0% by weight or more, or 5.0% by weight or more, or 6.0% by weight or more, or 7.0% by weight or more, or 8.0% by weight or more, or 9.0% by weight or more, while At the same time, it may contain 10.0% by weight or less, or 9.0% by weight or less, or 8.0% by weight or less, or 7.0% by weight or less, or 6.0% by weight or less, or 5.0% by weight or less, or 4.0% by weight or less, or 3.0% by weight or less, or 2.0% by weight or less, or 1.0% by weight or less, or 0.9% by weight or less, or 0.8% by weight or less, or 0.7% by weight or less, or 0.6% by weight or less, or 0.5% by weight or less, or 0.4% by weight or less, or 0.3% by weight or less, or 0.2% by weight or less of each additive.

[0040] HALS are chemical compounds containing amine functional groups that are used as stabilizers in plastics and polymers. These compounds may be derivatives of tetramethylpiperidine and are primarily used to protect polymers from the effects of free radical oxidation due to exposure to UV light. HALS include poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol-alt-1,4-butanedioic acid) (CAS#65447-77-0); bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (CAS#52829-07-9); di-(1,2,2,6,6-pentamethyl-4-piperidyl)-2-butyl-2-(3,5-di-tert-butyl-4-hydroxybenzyl) ) malonate (CAS#63843-89-0); bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate (CAS#129757-67-1); 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-pi 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)imino](CAS#71878-19-8); N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-(CAS#106990-43-6); 1,6-hexanediamine, 2,4,6-trichloro-1,3,5-triazine with N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-polymer, N-butyl-1-butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine reaction product (CAS#192268-64-7). Examples of HALS are commercially available from BASF (Ludwigshafen, Germany) under the trade names TINUVIN™ 622 and CHIMASSORB™ 944.Other UV stabilizers include, for example, UVASORB™ HA10 and HA88 (both commercially available from 3V Sigma USA), CHIMASSORB™ 944 LD (commercially available from BASF), and CYASORB® THT 4801, THT 7001, and THT 6460 (each commercially available from Solvay Corp.).

[0041] The polymer composition may be free of carbon black. As used herein, the term "free" is defined to mean that the formulation contains less than 0.5 wt.% of carbon black based on the total weight of the polymer composition. As emphasized above, carbon black is effective in absorbing ultraviolet light and preventing free radical generation, but it has a strong effect on the ability to impart a desired color to the polymer composition.

[0042] The polymer composition may include a colorant. As explained above, the absence of carbon black allows the polymer composition to be colored with a colorant. The colorant may include one or more of an azo dye, an anthraquinone dye, and a phthalocyanine. The polymer composition may contain one or more COLOUR INDEX™ generic name colorants, such as, for example, 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).

[0043] The polymer composition may contain one or more particulate fillers, such as glass fibers or various mineral fillers, including nanocomposites. Fillers, particularly those containing elongated or platelet-like particles that provide a higher aspect ratio (length / thickness), may improve modulus and post-extrusion shrinkage properties. The fillers may have a median size or d50 of less than 20 μm, less than 10 μm, or less than 5 μm. The fillers may be surface-treated to facilitate 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 silica, talc, mica, clay, kaolin, wollastonite, feldspar, aluminum hydroxide, and graphite. The filler may be included in the polymer composition in an amount ranging from 2 to 30 wt %, or from 5 to 30 wt %, based on the total weight of the polymer composition.

[0044] Processing aids may include metal salts of fluoroplastics such as polytetrafluoroethylene or fluorinated ethylene propylene; carboxylic acids such as zinc stearate or calcium stearate; fatty acids such as stearic acid, oleic acid, or erucic acid; fatty amides such as stearamide, oleamide, erucamide, or N,N'-ethylenebis-stearamide; polyethylene waxes; oxidized polyethylene waxes; polymers of ethylene oxide; copolymers of ethylene oxide and propylene oxide; vegetable waxes; petroleum waxes; nonionic surfactants; silicone fluids and polysiloxanes.

[0045] Antioxidants include hindered phenols such as tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydro-cinnamate)]methane; bis[(beta-(3,5-di-tert-butyl-4-hydroxybenzyl)methylcarboxyethyl)]-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 thiodiethylenebis(3,5-di-tert-butyl-4-hydroxy)-hydrocinnamate; tris(2,4-di-tert-butylphenyl)phosphazene; thio compounds such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate; various siloxanes; polymeric 2,2,4-trimethyl-1,2-dihydroquinoline, n,n'-bis(1,4-dimethylpentyl-p-phenylenediamine), alkylated diphenylamines, 4,4'-bis(alpha,alpha-dimethylbenzyl)diphenylamine, diphenyl-p-phenylenediamine, mixed diaryl-p-phenylenediamines, and other hindered amine antidegradants or stabilizers.

[0046] combination 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 prepared first to blend with other components. Melt blending can be performed at temperatures above the highest molten polymer. The melt-blended composition can then be delivered to an extruder or injection molding machine, passed through a die to form the desired article, or converted into pellets, tape, strip, film, or other forms for storage or preparation of the material for subsequent molding or processing steps. Optionally, if formed into pellets or some similar configuration, the pellets or the like can be coated with an anti-blocking agent to facilitate handling during storage.

[0047] Examples of compounding equipment that can be used include an internal batch mixer, a continuous single or twin screw mixer, or a kneading continuous extruder. The type of mixer utilized and the operating conditions of the mixer affect the properties of the composition, such as viscosity, volume resistivity, and extruded surface smoothness.

[0048] Mechanical properties The polymeric composition may exhibit an unaged (i.e., unaged), UV-aged, and / or heat-aged ultimate tensile strength, as measured according to ASTM D638, of 20.0 megapascals (MPa) to 45.0 MPa. For example, the polymeric composition may have a 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 above, or 29.0MPa or above, or 29.5MPa or above, or 30.0MPa or above, or 30.5MPa or above, or 31.0MPa or above, or 31.5MPa or above, or 32.0MPa or above, or 32.5MPa or above, or 33.0MPa or above, or 33.5MPa or above, or 34.0MPa or above, or 34.5MPa or above, or 35.0MPa or above, or 35.5MPa or above, or 36.0MPa or above, or 36.5MPa or above, or 37.0MPa or above, or 37.5MPa or above, or 38. 0 MPa or more, or 38.5 MPa or more, or 39.0 MPa or more, or 39.5 MPa or more, or 40.0 MPa or more, or 40.5 MPa or more, or 41.0 MPa or more, or 41.5 MPa or more, or 42.0 MPa or more, or 42.5 MPa or more, or 43.0 MPa or more, or 43.5 MPa or more, or 44.0 MPa or more, or 44.5 MPa or more, while simultaneously 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 a or less, or 42.5MPa or less, or 42.0MPa or less, or 41.5MPa or less, or 41.0MPa or less, or 40.5MPa or less, or 40.0MPa or less, or 39.5MPa or less, or 39.0MPa or less, or 38.5MPa or less, or 38.0MPa or less, or 37.5MPa or less, or 37.0MPa or less, or 36.5MPa or less, or 36.0MPa or less, or 35.5MPa or less, or 35.0MPa or less, or 34.5MPa or less, or 34.0MPa or less, or 33.It may exhibit an ultimate tensile strength of 5 MPa or less, or 33.0 MPa or less, or 32.5 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.

[0049] The polymeric composition may exhibit an unaged, UV-aged, or heat-aged elongation at break of 600% to 1200%, as measured according to ASTM D638. For example, the polymeric composition may have an 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 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 10 90% 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, while at the same time 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, is 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 it may exhibit an elongation at break of 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.

[0050] The polymer composition may have a retained maximum tensile strength and / or retained 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, while simultaneously, or 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.

[0051] coated conductor The present disclosure also provides a coated conductor. The coated conductor includes a conductor and a coating on the conductor, the coating including the polymer composition. The polymer composition is at least partially disposed around the conductor to produce the coated conductor. The conductor can include a conductive metal or an optically transparent structure.

[0052] The process for making coated conductors involves mixing and heating the polymer compositions 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 "on" includes direct or indirect contact between the polymer melt blend and the conductor. The polymer melt blend is in an extrudable state.

[0053] The polymer composition is disposed on and / or around the conductor to form a covering. The covering may be one or more inner layers, such as an insulating layer. The covering may completely or partially cover or otherwise surround or encase the conductor. The covering may be the only component surrounding the conductor. Alternatively, the covering may be one layer of a multi-layer jacket or sheath that encases the conductor. The covering may be in direct contact with the conductor. The covering may be in direct contact with an insulating layer that surrounds the conductor.

[0054] Example material The following materials are used in the examples below.

[0055] 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 by NMR. HDPE1 is available from The Dow Chemical Company, Midland, MI.

[0056] LLDPE1 is a linear low density polyethylene having a density of 0.926 g / cc, a melt index of 0.93 g / 10 min, and a butene comonomer content of 7.5 wt. % as measured by NMR. LLDPE1 is available from The Dow Chemical Company, Midland, MI.

[0057] HDPE2 is an ethylene homopolymer with a density of 0.961 g / cc, a melt index of 0.80 g / 10 min, and is available from The Dow Chemical Company (Midland, MI).

[0058] 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 by NMR. LLDPE2 is available from The Dow Chemical Company, Midland, MI.

[0059] AO is a hindered phenolic antioxidant with the chemical name pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) and is commercially available as IRGANOX™ 1010 from BASF (Ludwigshafen, Germany).

[0060] UVA is an ultraviolet absorber having the chemical composition 2-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)-4-methylphenol (CAS number 3896-11-5) and is commercially available as TINUVIN™ 326 from BASF, Ludwigshafen, Germany.

[0061] HALS is a 50 wt% mixture of 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-butanedioic acid) (CAS No. 65447-77-0), commercially available as TINUVIN™ 783 from BASF, Ludwigshafen, Germany.

[0062] PA is a fluoropolymer processing aid commercially available under the trade name DYNAMAR™ FX 5912, available from 3M (Saint Paul, Minnesota, USA).

[0063] Sample preparation Samples were prepared by compounding HDPE and LLDPE in a BRABENDER™ mixer at 150°C. The mixer rotor speed was set at 30 revolutions per minute ("RPM"). All ingredients except HDPE and LDPE 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.

[0064] A 40-gram piece was sandwiched between two biaxially oriented polyethylene terephthalate (i.e., Mylar) sheets and placed in a mold measuring 100 millimeters ("mm") x 200 mm x 2 mm. The mold was placed in a KT-201-A hot press manufactured by Shanghai Great Instrument Co., Ltd. and preheated to 170°C for 10 minutes. The mold was vented eight times. The mold was then held at 170°C and 10 MPa (measured in the hot press) for an additional 5 minutes. The mold was then cooled to room temperature with internal water cooling at 10 MPa within 5 minutes to form a plaque. The plaque was cut into 5A dog bones according to ISO 527-2.

[0065] UV Aged Sample: As used herein, UV aged samples are prepared by subjecting 5A dog bones to a UV aging protocol. The UV aging protocol consists of placing the 5A dog bones selected for accelerated UV aging in a Q-Lab QUV accelerated weathering tester equipped with SOLAR EYE™ irradiance control and water spray, used for accelerated UV aging according to ASTM D1248-16. The aging conditions are 0.70 W / (m) at 340 nm using a UVA-340 fluorescent lamp. 2 The irradiance was 1000 nm (1000 irradiance), and the uninsulated black panel temperature was maintained at 70±3°C for 20 hours and then at 55±3°C for 4 hours with dark point condensation. UV aging was performed for 2000 hours, including the dark point condensation period.

[0066] Heat-aged samples: Heat-aged samples were prepared according to GB / T2951.12-2008 by placing five dog bones from each example in an oven at 100°C for 240 hours.

[0067] Test Method Nuclear Magnetic Resonance: The total comonomer content of the sample is 13 C nuclear magnetic resonance. NMR is performed by dissolving the sample in trichloroethane-d4 ("TCE-d4") at 120°C to form a homogeneous solution. All NMR data is obtained using a 100.6 MHz 13 The measurements were taken at 120°C on a Bruker AVANCE™ II 400 MHz spectrometer operating at the C resonance frequency. A 10 mm BBO probe was used. Chemical shifts were given in ppm (parts per million) relative to TCE-d4. Zgig was measured with a 90 degree observation pulse. 13 The C NMR pulse program was used. The recycle delay was set to 6 seconds. The sample was scanned 4000 times. The comonomer content of each ethylene-based polymer was determined following the same procedure as above.

[0068] result Table 1 provides the compositions 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 ("TSMax"), tensile elongation at break ("TE"), maximum tensile strength retention ("TS Retention"), and tensile elongation retention at break ("TE Retention") for CE1-CE3 and IE1-IE9. [Table 1] [Table 2]

[0069] With reference to Tables 1 and 2, it can be seen that increasing the total comonomer content of the examples generally increases the UV-aged and heat-aged tensile elongation at break and tensile elongation retention until the total comonomer content reaches 2.9 wt%. After reaching 2.9 wt%, the samples exhibited retained tensile elongation at break of 75% or more, and tensile elongation at break of 600% or more, indicating that the samples are likely to pass the more stringent standards set by ASTM D1248-16 and IEC 60811-401-2017 applicable to cable jacketing. As explained above, it is surprising that the UV-aged and heat-aged mechanical properties of polymer compositions exhibit a dependence on total comonomer content, and that a critical value of total comonomer content of 2.9 wt% or more can exhibit desirable properties. Even more surprising, IE1-IE9, all of which have densities of 0.930 g / cc or more, exhibit greater retention of mechanical properties under UV-aged and heat-aged conditions than CE1-CE3. (Aspect) (Aspect 1) 1. A polymer composition comprising: a first ethylene-based polymer having a density, as measured in accordance with ASTM D792, between 0.941 g / cc and 0.970 g / cc; a second ethylene-based polymer having a density, as measured in accordance with ASTM D792, between 0.860 g / cc and 0.930 g / cc; an additive selected from the group consisting of an antioxidant, a hindered amine light stabilizer, and combinations thereof; A polymer composition, wherein the polymer composition has a total comonomer content of 2.9 wt. % or greater, based on the total weight of the polymer composition. (Aspect 2) 2. The polymer composition of embodiment 1, wherein the polymer composition comprises 40% to 95% by weight of the first ethylene-based polymer, based on the total weight of the polymer composition. (Aspect 3) 3. The polymer composition of embodiment 2, wherein the polymer composition comprises 5% to 60% by weight of the second ethylene-based polymer, based on the total weight of the polymer composition. (Aspect 4) 4. The polymer composition of embodiment 3, wherein the polymer composition is carbon black-free. (Aspect 5) 5. The polymer composition of any one of the preceding embodiments, wherein the polymer composition has a density less than or equal to 0.945 g / cc as measured according to ASTM D792. (Aspect 6) 6. The polymer composition of embodiment 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. (Aspect 7) 5. The polymer composition of any one of the preceding aspects, wherein the polymer composition has a density of from 0.930 g / cc to 0.945 g / cc, as measured according to ASTM D792. (Aspect 8) 8. The polymer composition of embodiment 7, wherein the second ethylene-based polymer has a density from 0.918 g / cc to 0.930 g / cc as measured in accordance with ASTM D792. (Aspect 9) 9. The polymer composition of embodiment 8, wherein the polymer composition exhibits a tensile elongation at break of greater than or equal to 600%, as measured according to ASTM D638, after aging at 100° C. for 240 hours. (Aspect 10) A coated conductor, A conductor; and the polymer composition according to any one of aspects 1 to 9 disposed around the conductor.

Claims

1. 1. A polymer composition comprising: 48.98 wt% to 83.98 wt%, based on the total weight of the polymer composition, of a first ethylene-based polymer having a density from 0.941 g / cc to 0.970 g / cc, as measured in accordance with ASTM D792; 15.00 wt% to 48.98 wt%, based on the total weight of the polymer composition, of a second ethylene-based polymer having a density from 0.918 g / cc to 0.930 g / cc, as measured in accordance with ASTM D792; 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 greater than, or equal to, 3.04 wt%, based on the total weight of the first ethylene-based polymer and the second ethylene-based polymer; A polymeric composition that is free of carbon black.

2. 10. The polymer composition of claim 1, wherein the polymer composition comprises 50% to 80% by weight of the first ethylene-based polymer, based on the total weight of the polymer composition.

3. 3. The polymer composition of claim 2, wherein the polymer composition comprises 15% to 45% by weight of the second ethylene-based polymer, based on the total weight of the polymer composition.

4. The polymer composition of any one of claims 1 to 3, wherein the polymer composition has a density of less than or equal to 0.945 g / cc as measured according to ASTM D792.

5. 5. The polymer composition of claim 4, 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.

6. The polymer composition of any one of claims 1 to 3, wherein the polymer composition has a density of from 0.930 g / cc to 0.945 g / cc as measured according to ASTM D792.

7. 10. The polymer composition of claim 1, wherein the polymer composition exhibits a tensile elongation at break of 600% or greater as measured according to ASTM D638 after aging at 100°C for 240 hours.

8. A coated conductor, A conductor; and the polymer composition according to any one of claims 1 to 7 disposed around the conductor.

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