Methods of making masterbatches

Abstract

A method of making a masterbatch includes the steps of forming a masterbatch including 20 wt% to 70 wt% of an acrylonitrile-butadiene copolymer based on a total weight of the masterbatch and 20 wt% to 70 wt% of an ethylene-vinyl acetate copolymer based on a total weight of the masterbatch. Next a step of pelletizing the masterbatch is performed.

Description

[0001] METHODS OF MAKING MASTERBATCHES

[0002] BACKGROUND

[0003] Field of the disclosure

[0004] The present disclosure relates to masterbatches, and more specifically, to masterbatches that include acrylonitrile-butadiene and ethylene-vinyl acetate

[0005] Introduction

[0006] Power cables generally have one or more conductors in the core which are surrounded by several protective layers. The protective layers may include a first polymeric semiconducting shield layer, a polymeric insulating layer, a second polymeric semiconducting strippable shield layer, a metallic tape shield and a polymeric jacket. Strippable dielectric shield layer on a medium voltage power cable provides limited adhesion to the insulation layer so that the strippable shield can be peeled away cleanly from the insulation without removing any insulation. The strippable dielectric shield layer may include ethylene vinyl acetate (“EVA”) polymer, nitrile butadiene copolymer, carbon black and other additives. For example, United States Patent Number 10,501,645 discloses a semiconducting shield layer made from (A) 45- 52% ethylene vinyl acetate (B) 30-45% carbon black and (C) 5-20% acrylonitrile butadiene copolymer (“NBR”). Other combinations of EVA and NBR are provided in Korean Patent Publication 20190022089A and United States Patent Publication 2021 / 0079199A1.

[0007] NBR in strippable compositions acts as a strip reduction aid, but suffers from several manufacturing and process related issues in use. First, NBR pellets exhibit a tendency of blocking exit orifices of hoppers and loaders under ambient manufacturing conditions. NBR has a glass transition temperature below 0°C which results in NBR chunks exhibiting a sticky characteristic and high viscoelastic deformation at its interfaces. These properties render it difficult to meter in the correct amount of NBR into a formulation from a hopper as the NBR chunks tend to agglomerate and block exit orifices of hoppers and loaders. One measure for quantification of the resistance a material exhibits when passing through an office like this is the peak load of a ram required to push the material through an opening and is measured according to Peak Load Testing. Ideally, the peak load should be 30 newtons or less at 37°C.

[0008] One manner of overcoming the manufacturing issues with NBR is to include a partitioning agent such as talc and other minerals to the NBR. The introduction of the partitioning agent to the NBR helps keep the interfaces between the NBR separated so that the NBR does not congeal together. Despite the addition of partitioning agents, the NBR still needs to be stored and transported in climate-controlled environments to prevent congealing. Further, despite the incorporation of partitioning agents, the NBR tends to still exhibit blocking during summer months while being fed into compounders. The addition of partitioning agents is not without its own setbacks. The additional material of the partitioning agents and steps of compounding the agents into the NBR adds additional cost and complexity to the manufacture of the NBR which is ultimately born by the end consumer. The variation in the amount of partitioning agent on the surface of copolymer particles renders batch to batch variability as a raw materia] in the compounding process and final product. Additionally, the partitioning agents are considered an impurity in the strippable shields it ultimately is incorporated into. While blocking and partitioning agent impurities are issues for manufactures utilizing the NBR in continuous compounders, the these are not issues for large scale copolymer compounders and therefor have not been addressed before.

[0009] In view of the foregoing, it would be surprising to discover a method of incorporating NBR into a formulated system such that a peak load force of adding the NBR is less than 30 newtons at 37°C as measured according to Peak Load Testing and also is free of partitioning agent.

[0010] SUMMARY OF THE DISCLOSURE

[0011] The inventors of the present disclosure have discovered a method of incorporating NBR into a formulated system such that a peak load force of adding the NBR is less than 30 newtons at 37°C as measured according to Peak Load Testing and also is free of partitioning agent.

[0012] The present disclosure is the result of recognizing that by forming a masterbatch of NBR and an ethylene-vinyl acetate copolymer, that the resulting masterbatch can significantly reduce blocking while also being free of partitioning agent. Surprisingly, it has been discovered that despite the low glass transition temperature of NBR being the apparent source of the sticky and high viscoelastic deformation characteristics of NBR, using another low glass transition temperature material, EVA, to form a pelletized masterbatch with the NBR results in peak load of less than 30 newtons at 37°C as measured according to Peak Load Testing.

[0013] According to a feature of the present disclosure, a method of making a masterbatch, comprises the steps of forming a masterbatch comprising 20 wt% to 70 wt% of an acrylonitrilebutadiene copolymer based on a total weight of the masterbatch; and 20 wt% to 70 wt% of an ethylene-vinyl acetate copolymer based on a total weight of the masterbatch; and pelletizing the masterbatch. According to another feature of the present disclosure, the ethylene-vinyl acetate copolymer is free of silane functionality and the masterbatch is free of partitioning agent.

[0014] According to another feature of the present disclosure, the masterbatch exhibits a glass transition temperature of less than -20° C as measured according to ASTM E1356.

[0015] According to another feature of the present disclosure, the ethylene-vinyl acetate copolymer comprises from 25 wt% to 45 wt% of vinyl acetate based on a total weight of the ethylene-vinyl acetate copolymer.

[0016] According to another feature of the present disclosure, the ethylene-vinyl acetate copolymer comprises from 30 wt% to 35 wt% of vinyl acetate based on a total weight of the ethylene-vinyl acetate copolymer.

[0017] According to another feature of the present disclosure, the acrylonitrile-butadiene copolymer comprises from 25 wt% to 40 wt% of acrylonitrile based on the total weight of the acrylonitrile-butadiene copolymer.

[0018] According to another feature of the present disclosure, the masterbatch comprises 40 wt% to 60 wt% of the acrylonitrile-butadiene copolymer based on a total weight of the masterbatch.

[0019] According to another feature of the present disclosure, the masterbatch comprises 40 wt% to 60 wt% of the ethylene-vinyl acetate copolymer based on a total weight of the masterbatch.

[0020] According to another feature of the present disclosure, the acrylonitrile-butadiene copolymer exhibits a Mooney Viscosity of from 30 Mu to 80 MU as measured according to ASTM D1646 (ML1+4 at 100°C).

[0021] According to another feature of the present disclosure, the acrylonitrile-butadiene copolymer exhibits a Mooney Viscosity of from 40 Mu to 50 MU or 65 Mu to 75 Mu as measured according to ASTM D1646 (ML1+4 at 100°C).

[0022] According to another feature of the present disclosure, a coated conductor, comprising a conductor; and the masterbatch positioned around the conductor.

[0023] DETAILED DESCRIPTION

[0024] 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. All ranges include endpoints unless otherwise stated.

[0025] Test methods refer to the most recent test method as of the priority date of this document unless a date is indicated with the test method number as a hyphenated two-digit number. References to test methods contain both a reference to the testing society and the test method number. Test method organizations are referenced by one of the following abbreviations: ASTM refers to ASTM International (formerly known as American Society for Testing and Materials); EN refers to European Norm; DIN refers to Deutsches Institut fur Normung; and ISO refers to International Organization for Standards. When used herein, Chemical Abstract Services registration numbers refer to the most recent chemical or chemical composition designated for that registration number as of the priority date of this document.

[0026] As used herein, the term weight percent (“wt%”) designates the percentage by weight a component is of a total weight of the polymeric composition unless otherwise indicated. The term mole percent (“mol%”) designates the percentage by moles a component is of a total mole of the item in which the component is present.

[0027] Unless otherwise provided herein, density is measured in accordance with ASTM D792, Method B. The result is recorded in grams (g) per cubic centimeter (g / cc).

[0028] Unless otherwise provided herein, a melt index (MI) is measured in accordance with ASTM D1238, Condition 190°C / 2.16 kilogram (kg) weight and is reported in grams eluted per 10 minutes (g / 10 min).

[0029] "Polymer" means a polymeric compound prepared by polymerizing monomers, whether of the same or a different type. The generic term polymer thus embraces the terms homopolymer, interpolymer and copolymer.

[0030] Method

[0031] The present disclosure provides a method of making a masterbatch. The method includes steps of forming the masterbatch and pelletizing the masterbatch. As used herein, the term “masterbatch” means a pre-compounded mixture of two or more materials. Masterbatches are used to simplify production of various compositions because their use eliminates multiple weighing and addition steps. Additionally, by pre-compounding the acrylonitrile-butadiene copolymer and the ethylene-vinyl acetate into a masterbatch, challenges associated with handing the acrylonitrile-butadiene copolymer may be eliminated. The masterbatch may comprise acrylonitrile-butadiene copolymer and ethylene- vinyl acetate. The masterbatch may be free of partitioning agents. As used herein, the term “partitioning agents” means talc, mineral dust, polyethylene dust, and other solid or liquid materials added to the masterbatch for the purpose of keeping individual portions of the masterbatch components from congealing. As used herein, the term “free of partitioning agents’" means that the masterbatch comprises 0.1 wt% or less of any partitioning agents based on the total weight of the masterbatch and / or that no partitioning agents were purposefully added.

[0032] The step of forming the masterbatch may be accomplished in a variety of manners. For example, the masterbatch may be formed by hot melt compounding, lamination, coextrusion, Henschel blending, encapsulation or combinations thereof. The step may be performed at a temperature sufficiently high for one or more of the components of the masterbatch to be melted thereby allowing blending of the materials together.

[0033] After the step of forming the masterbatch, the step of pelletizing the masterbatch is performed. As highlighted above, acrylonitrile-butadiene copolymer and ethylene-vinyl acetate are known to be used together and coextruded to form components for wire and cable applications. What is heretofore unknown is the step of pelletizing the masterbatch such that it can be used for later extruding. Pelletizing of the masterbatch can be accomplished in a variety of manners including strand pelletizers, underwater pelletizers, drop pelletizers, hot die face pelletizers, cold pelletizers, water ring pelletizers or combinations thereof. The final pellets may have a spherical, cylindrical, or other geometric shape with a longest length dimension of from 5 mm to 10 mm.

[0034] Despite the low glass transition temperature of acrylonitrile-butadiene copolymer being the believed driver for pellet agglomeration in traditional systems, the masterbatch surprisingly exhibits a glass transition temperature of less than -20° C as measured according to ASTM El 356. For example, the glass transition temperature of the masterbatch may be -20° C or less, or -21° C or less, or -22° C or less, or -23° C or less, or -24° C or less, or -25° C or less, or - 26° C or less, or -27° C or less, or -28° C or less as measured according to ASTM E1356.

[0035] Acrylonitrile-butadiene copolymer

[0036] The masterbatch comprises acrylonitrile-butadiene copolymer. The acrylonitrile- butadiene copolymer is commonly referred to in the art as nitrile copolymer or simply NBR. The acrylonitrile-butadiene copolymer comprises from 25 wt% to 40 wt% of acrylonitrile based on the total weight of the acrylonitrile-butadiene copolymer. For example, the acrylonitrile-butadiene copolymer comprises 25 wt% or more, or 26 wt% or more, or 28 wt% or more, or 30 wt% or more, or 32 wt% or more, or 34 wt% or more, or 36 wt% or more, or 38 wt% or more, while at the same time, 40 wt% or less, or 38 wt% or less, or 36 wt% or less, or 34 wt% or less, or 32 wt% or less, or 30 wt% or less, or 28 wt% or less, or 26 wt% or less of acrylonitrile based on the total weight of the acrylonitrile-butadiene copolymer.

[0037] The acrylonitrile-butadiene copolymer may exhibit a glass transition temperature of - 20° C or less, or -21° C or less, or -22° C or less, or -23° C or less, or -24° C or less, or -25° C or less, or -26° C or less, or -27° C or less, or -28° C or less as measured according to ASTM El 356.

[0038] The masterbatch comprises 20 wt% to 70 wt% of the acrylonitrile-butadiene copolymer based on a total weight of the masterbatch. For example, the masterbatch may comprise 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, or 60 wt% or more, or 65 wt% or more, while at the same time, 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, or 40 wt% or less, or 35 wt% or less, or 30 wt% or less, or 25 wt% or less of acrylonitrile-butadiene copolymer based on a total weight of the masterbatch.

[0039] The acrylonitrile-butadiene copolymer may exhibit a Mooney Viscosity of from 30 Mu to 80 MU as measured according to ASTM D1646 (ML1+4 at 100°C). For example, the Mooney Viscosity may be 30 Mu or greater, or 35 Mu or greater, or 40 Mu or greater, or 45 Mu or greater, or 50 Mu or greater, or 55 Mu or greater, or 60 Mu or greater, or 65 Mu or greater, or 70 Mu or greater, or 75 Mu or greater, while at the same time, 80 Mu or less, or 75 Mu or less, or 70 Mu or less, or 65 Mu or less, or 60 Mu or less, or 55 Mu or less, or 50 Mu or less, or 45 Mu or less, or 40 Mu or less, or 35 Mu or less as measured according to ASTM D1646 (ML1+4 at 100°C). In a specific example, the acrylonitrile-butadiene copolymer exhibits a Mooney Viscosity of from 40 Mu to 50 MU or 65 Mu to 75 Mu as measured according to ASTM D1646 (ML1+4 at 100°C).

[0040] Ethylene-vinyl acetate

[0041] Ethylene-vinyl acetate is a copolymer of ethylene and vinyl acetate. According to various examples, the ethylene- vinyl acetate copolymer is free of silane functionality, either grafted or copolymerized therewith. The ethylene- vinyl acetate copolymer may comprise from 25 wt% to 45 wt% of vinyl acetate based on a total weight of the ethylene-vinyl acetate copolymer. For example, the ethylene-vinyl acetate copolymer may comprise 25 wt% or greater, or 30 wt% or greater, or 31 wt% or greater, or 32 wt% or greater, or 33 wt% or greater, or 34 wt% or greater, or 35 wt% or greater, or 40 wt% or greater, while at the same time, 45 wt% or less, or 40 wt% or less, or 35 wt% or less, or 30 wt% or less of vinyl acetate based on a total weight of the ethylene-vinyl acetate copolymer. The balance of the ethylene-vinyl acetate may be ethylene and one or more other comonomers.

[0042] The ethylene- vinyl acetate may exhibit a glass transition temperature of -20° C or less, or -21° C or less, or -22° C or less, or -23° C or less, or -24° C or less, or -25° C or less, or - 26° C or less, or -27° C or less, or -28° C or less as measured according to ASTM E1356.

[0043] The masterbatch comprises 20 wt% to 70 wt% of the ethylene- vinyl acetate based on a total weight of the masterbatch. For example, the masterbatch may comprise 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, or 60 wt% or more, or 65 wt% or more, while at the same time, 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, or 40 wt% or less, or 35 wt% or less, or 30 wt% or less, or 25 wt% or less of ethylene-vinyl acetate based on a total weight of the masterbatch.

[0044] Additives

[0045] The masterbatch may include one or more additives. Nonlimiting examples of suitable additives include antioxidants, colorants, corrosion inhibitors, lubricants, ultraviolet (UV) absorbers or stabilizers, anti-blocking agents, flame-retardants, coupling agents, compatibilizers, plasticizers, fillers, processing aids, and combinations thereof.

[0046] The masterbatch may include an antioxidant. Nonlimiting examples of suitable antioxidants include phenolic antioxidants, thio-based antioxidants, phosphate-based antioxidants, and hydrazine-based metal deactivators. Suitable phenolic antioxidants include high molecular weight hindered phenols, methyl-substituted phenol, phenols having substituents with primary or secondary carbonyls, and multifunctional phenols such as sulfur and phosphorous-containing phenol. Representative hindered phenols include 1,3,5-trimethyl- 2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-benzene; pentaerythrityl tetrakis-3(3,5-di-tert- butyl-4-hydroxyphenyl)-propionate; n-octadecyl-3(3,5-di-tert-butyl-4-hydroxyphenyl)- propionate; 4,4'-methylenebis(2,6-tert-butyl-phenol); 4,4'-thiobis(6-tert-butyl-o-cresol); 2,6- di-tertbutylphenol;6-(4-hydroxyphenoxy)-2,4-bis(n-octyl-thio)-l,3,5 triazine; di-n- octylthio)ethyl 3,5-di-tert-butyl-4-hydroxy-benzoate; and sorbitol hexa[3-(3,5-di-tert-butyl-4- hydroxy-phenyl)-propionate]. The polymeric composition may include pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), commercially available as Irganox™ 1010 from BASF. A nonlimiting example of a suitable methyl-substituted phenol is isobutylidenebis(4,6-dimethylphenol). A nonlimiting example of a suitable hydrazine-based metal deactivator is oxalyl bis(benzylidiene hydrazide). The masterbatch may contain from 0 wt%, or 0.001 wt%, or 0.01 wt%, or 0.02 wt%, or 0.05 wt%, or 0.1 wt%, or 0.2 wt %, or 0.3 wt %, or 0.4 wt% to 0.5 wt%, or 0.6 wt %, or 0.7 wt%, or 0.8 wt %, or 1.0 wt %, or 2.0 wt%, or 2.5 wt%, or 3.0 wt% antioxidant, based on total weight of the masterbatch.

[0047] The masterbatch may include a processing aid. Nonlimiting examples of suitable processing aids include oils, organic acids (such as stearic acid), and metal salts of organic acids (such as zinc stearate). In an embodiment, the composition contains from 0 wt%, or 0.01 wt%, or 0.02 wt%, or 0.05 wt%, or 0.07 wt%, or 0. 1 wt%, or 0.2 wt %, or 0.3 wt %, or 0.4 wt% to 0.5 wt%, or 0.6 wt %, or 0.7 wt%, or 0.8 wt %, or 1.0 wt %, or 2.0 wt%, or 2.5 wt%, or 3.0 wt%, or 5.0 wt%, or 10.0 wt%, or 20.0 wt% processing aid, based on total weight of the masterbatch.

[0048] The masterbatch may contain from 0 wt% or greater, or 0.001 wt% or greater, or 0.002 wt% or greater, or 0.005 wt% or greater, or 0.006 wt% or greater, or 0.008 wt% or greater, or 0.009 wt% or greater, or 0.01 wt% or greater, or 0.2 wt% or greater, or 0.3 wt% or greater, or 0.4 wt% or greater, or 0.5 wt% or greater, or 1.0 wt% or greater, or 2.0 wt% or greater, or 3.0 wt% or greater, or 4.0 wt% or greater, or 5.0 wt% or greater, or 10.0 wt% or greater, or 15.0 wt% or greater, or 20.0 wt% or greater, or 30 wt% or greater, or 40 wt% or greater, or 50 wt% or greater additive, based on the total weight of the masterbatch.

[0049] Coated Conductor

[0050] The present disclosure also provides a coated conductor. The coated conductor includes a conductor and a coating on the conductor, the coating including the masterbatch. The polymeric composition is at least partially disposed around the conductor to produce the coated conductor. The conductor may comprise a conductive metal or an optically transparent structure.

[0051] The process for producing a coated conductor includes mixing and heating the masterbatch to at least the melting temperature of the polymeric components in an extruder to form a polymeric melt blend, and then coating the polymeric melt blend onto the conductor. The term "onto" includes direct contact or indirect contact between the polymeric melt blend and the conductor. The polymeric melt blend is in an extrudable state.

[0052] The polymeric composition is disposed on and / or around the conductor to form a coating. The coating may be one or more inner layers such as an insulating layer. The coating may wholly or partially cover or otherwise surround or encase the conductor. The coating may be the sole component surrounding the conductor. Alternatively, the coating may be one layer of a multilayer jacket or sheath encasing the conductor. The coating may directly contact the conductor. The coating may directly contact an insulation layer surrounding the conductor.

[0053] Examples

[0054] Materials

[0055] The following materials were used in the formation of the inventive and comparative examples.

[0056] EVA is an ethylene vinyl acetate copolymer having a vinyl acetate content of 33 wt% based on the total weight of the copolymer and a glass transition temperature of -33° C as measured according to ASTM E1356. The EVA is available as ELVAX™ CM4987W from The Dow Chemical Company, Midland, Michigan.

[0057] NBR1 is acrylonitrile butadiene copolymer having an Acrylonitrile content of 33 wt% based on the total weight of the acrylonitrile butadiene copolymer and a Mooney Viscosity of 45 Mu. NBR1 is commercially available as Krynac 3345 from Arlanxeo, Netherlands BV.

[0058] NBR2 is acrylonitrile butadiene copolymer having an Acrylonitrile content of 33 wt% based on the total weight of the acrylonitrile butadiene copolymer and a Mooney Viscosity of 70 Mu. NBR2 is commercially available as Krynac 3370 from Arlanxeo, Netherlands BV.

[0059] Test Methods

[0060] Acrylonitrile content is determined in accordance with ISO 24698.

[0061] Glass transition temperature is measured according to ASTM El 356.

[0062] Mooney Viscosity is measured according to ASTM D 1646 (ML1+4 at 100°C). The ML1+4 at 100°C indicates the final torque at 100°C after 4 minutes of testing with 1 minute of preheating time using a large rotor.

[0063] Peak Load Testing: Load two hundred (200) grams of sample into a gaylord box style sintering cell. Add 2.72 kg pounds of ball bearing weight into a load ram configured to exert force on the gaylord box style sintering cell. Heat the sintering cell to a temperature of 37°C for six hours. After heating of the samples, remove the load ram from the sintering cell and install the sintering cell on an INSTRON™ compression tester with a sintering cell plate. Calibrate the compression tester. If a test ram of the compression tester pushes the sintered sample out before the test is begun, record the peak load force as 0. Activate the compression tester to run at 5 mm per minute to determine the peak load force required to push the sintered sample out of the sintering cell. Repeat the test 3 times per sample. Sample Preparation

[0064] CE1 and IE1-IE5 were made in BANBURY™ batch mixer using a typical multi-phase mixing process. The compositions and resulting properties of the examples are provided in Table 1. After mixing at 60 revolutions per minute, for 2 minutes at 105°C, the examples were dropped at 105°C into a single screw extruder to a GALA™ underwater pelletizer to produce pellets.

[0065] Results

[0066] Table 1

[0067] Referring now to Table 1, it can be seen that CE1 exhibits a significantly high degree of sintering, and as a result, Peak Load as compared to the inventive examples. The Peak Load exhibited by CE1 would be expected to cause a jam if loaded into a hopper. Referring now to IE1-IE5, the data show that the acrylonitrile-butadiene copolymer and ethylene-vinyl acetate copolymer masterbatch exhibits significantly reduced sintering and thus Peak Load. Such a result is surprising because the masterbatch has a glass transition temperature similar to that of the acrylonitrile-butadiene copolymer and does not comprise a partitioning agent. IE1-IE5 all demonstrate that the inventive method works over a wide masterbatch compositional range to reduce the Peak Load.

Claims

CLAIMSWhat is claimed is1. A method of making a masterbatch, comprising the steps of forming a masterbatch comprising:20 wt% to 70 wt% of an acrylonitrile-butadiene copolymer based on a total weight of the masterbatch; and20 wt% to 70 wt% of an ethylene- vinyl acetate copolymer based on a total weight of the masterbatch; and pelletizing the masterbatch.

2. The method of claim 1 , wherein the ethy lene- vinyl acetate copolymer is free of silane functionality and the masterbatch is free of partitioning agent.

3. The method of any one of claims 1 and 2, wherein the masterbatch exhibits a glass transition temperature of less than -20° C as measured according to ASTM E1356.

4. The method of any one of claims 1-3, wherein the ethylene-vinyl acetate copolymer comprises from 25 wt% to 45 wt% of vinyl acetate based on a total weight of the ethylenevinyl acetate copolymer.

5. The method of any one of claims 1-4, wherein the ethy lene- vinyl acetate copolymer comprises from 30 wt% to 35 wt% of vinyl acetate based on a total weight of the ethylenevinyl acetate copolymer.

6. The method of any one of claims 1-5, wherein the acrylonitrile-butadiene copolymer comprises from 25 wt% to 40 wt% of acrylonitrile based on the total weight of the acrylonitrile- butadiene copolymer.

7. The method of any one of claims 1-6, wherein the masterbatch comprises 40 wt% to 60 wt% of the acrylonitrile-butadiene copolymer based on a total weight of the masterbatch.

8. The method of any one of claims 1-7, wherein the masterbatch comprises 40 wt% to 60 wt% of the ethylene-vinyl acetate copolymer based on a total weight of the masterbatch.

9. The method of any one of claims 1-8, wherein the acrylonitrile-butadiene copolymer exhibits a Mooney Viscosity of from 30 Mu to 80 MU as measured according to ASTM DI 646 (ML1+4 at 100°C).

10. The method of claim 9, wherein the acrylonitrile-butadiene copolymer exhibits a Mooney Viscosity of from 40 Mu to 50 MU or 65 Mu to 75 Mu as measured according to ASTM DI 646 (ML1+4 at 100°C).

11. A coated conductor, comprising : a conductor; and the masterbatch of any one of claims 1-10 positioned around the conductor.

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