Polyethylene blend for cable applications

Abstract

A mixed-plastic-polyethylene composition is described. The mixed-plastic-polyethylene composition comprises: a) a blend of linear low-density polyethylene (LLDPE); and b) 5.0 to 50.0 wt.% of a cross- linked polyethylene (XLPE) recyclate, based on a total weight of the mixed-plastic-polyethylene composition; wherein the cross-linked polyethylene (XLPE) recyclate has a mean particle size of 0.7 mm to 25.0 mm. A process for preparing the mixed-plastic-polyethylene composition, an article comprising the mixed-plastic-polyethylene composition and use of the mixed-plastic-polyethylene composition are also described.

Description

[0001] Polyethylene blend for cable applications

[0002] Field of the Invention

[0003] The present invention relates to a mixed-plastic-polyethylene composition, which is typically suitable for use in an inner or an outer jacket of a cable. The invention relates to the use of a cross-linked polyethylene (XLPE) recyclate in a composition to provide a jacketing material that has good ESCR (Environmental Stress Crack Resistance), good impact properties and high flexibility. The invention also relates to an article comprising the composition, a process for preparing the composition and to the use of the composition.

[0004] Background

[0005] Polyethylene based materials are extensively used in packaging and coating materials. In particular, every year large amounts of wires and cables comprising these polyethylene based materials become waste. For example, in Sweden alone, there is approximately 40,000 tonnes of cable waste per year. The amount of cable installed in the community increases every year, but only a small part, about 1 / 6 of the cables built into the network, are being recycled.

[0006] Generally, recycled quantities of polyethylene on the market are mixtures of both polypropylene (PP) and polyethylene (PE), this is especially true for post-consumer waste streams. Moreover, commercial recyclates from post-consumer waste sources are conventionally cross contaminated with nonpolyolefin materials, such as polyethylene terephthalate, polyamide, polystyrene or non-polymeric substances like wood, paper, glass or aluminium. These cross-contaminations drastically limit final applications when recycling.

[0007] Recycled polyolefin materials normally have properties, which are much worse than those of the virgin materials, unless the amount of recycled polyolefin added to the final compound is extremely low. For example, such materials often have limited impact strength and poor mechanical properties (such as e.g. brittleness) and thus, they do not fulfil customer requirements for a variety of applications, such as jacketing materials for cables, containers, automotive components or household articles. This normally excludes the application of recycled materials from these applications and means that they are only used in applications that are low-cost and nondemanding, such as in construction or in furniture. In addition to these general challenges, crosslinked polyethylene (XLPE) recyclates have the specific challenge of being harder to recycle due to the crosslinking.

[0008] The largest potential for recycling applies to the cables in the communication and power distribution network. The polymer price depends on the oil price and is increasing with time, which is an economic driving force to recycle the cable plastic. Landfill of polymer waste is not an option in the future and it has not been allowed in EU countries since 2008, although in practice landfill is still used today. Currently, the landfill cost is already very high and will only rise. With all these reasons above, sustainable methods for sorting, mechanical recycling and re-use of cable plastics are needed.

[0009] Summary of the Invention

[0010] The present invention provides a mixed-plastic-polyethylene composition. The mixed-plastic- polyethylene composition comprises: a) a blend of a linear low-density polyethylene (LLDPE); and b) 5.0 to 50.0 wt.% of a cross-linked polyethylene (XLPE) recyclate, based on a total weight of the mixed-plastic-polyethylene composition; wherein the cross-linked polyethylene (XLPE) recyclate has a mean particle size of 0.7 mm to 25.0 mm.

[0011] The invention further relates to a mixed-plastic-polyethylene composition obtained or obtainable by blending and extruding components comprising: a) a blend of a linear low-density polyethylene (LLDPE); and b) 5.0 to 50.0 wt.% of a cross-linked polyethylene (XLPE) recyclate, based on a total weight of the mixed-plastic-polyethylene composition; wherein the cross-linked polyethylene (XLPE) recyclate has a mean particle size of 0.7 mm to 25.0 mm.

[0012] In general, the invention provides a mixed-plastic-polyethylene composition that includes a significant proportion of recycled cross-linked polyethylene (XLPE). The compositions have been found to have properties that meet all the key requirements for use as a jacketing material for a cable or a wire.

[0013] The combination of a blend of LLDPE and an XLPE recyclate having a relatively large particle size was surprisingly found to provide a composition with excellent impact properties and flexibility. In particular, the flexibility of the composition can be better than the flexibility of a composition comprising the virgin LLDPE as the only polymeric ingredient. Despite the relatively large particle size of the XLPE recyclate, it was unexpectedly easy to compound this ingredient with the blend of LLDPE during the manufacture of the composition.

[0014] The invention also relates to a process for preparing the mixed-plastic-polyethylene composition. The process comprises: a) providing a blend of a linear low-density polyethylene (LLDPE); b) providing a cross-linked polyethylene (XLPE) recyclate in an amount of 5.0 to 50.0 wt.% of, based on a total weight of the mixed-plastic-polyethylene composition, wherein the cross-linked polyethylene (XLPE) recyclate has a mean particle size of 0.7 mm to 25.0 mm; and c) melting and mixing the blend of linear low-density polyethylene (LLDPE) and the cross-linked polyethylene (XLPE) recyclate in an extruder.

[0015] The present invention further provides an article comprising the mixed-plastic-polyethylene composition. Typically, the article is a cable. The article or cable comprises at least one layer comprising the mixed-plastic-polyethylene composition of the invention, preferably the at least one layer is a jacketing layer comprising the mixed-plastic-polyethylene composition of the invention.

[0016] The invention further relates to the use of a mixed-plastic-polyethylene composition for producing a cable, preferably a cable jacket.

[0017] Definitions

[0018] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although, any methods and materials similar or equivalent to those described herein can be used in practice for testing of the present invention, the preferred materials and methods are described herein. In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below.

[0019] The term “virgin” as used herein with reference to a material, such as a blend or a polymer, refers to a a newly produced material, such as a blend or a polymer, that has not been used (e.g. subject to its first use) and has not already been recycled.

[0020] For the purposes of the present description and of the subsequent claims, the term “recycled waste” as used herein refers to a material recovered from post-consumer waste, as opposed to virgin polymers and / or materials. Post-consumer waste refers to objects having completed at least a first use cycle (or life cycle), i.e. having already served their first purpose. The term “recycled material” such as used herein denotes materials reprocessed from “recycled waste”. The term “recyclate” refers to a raw material obtained or obtainable from a recycled waste or a recycled material.

[0021] The term “natural” in the context of the present invention means that the accordant component is of natural colour. This means that no pigments (including carbon black) are included in the accordant component of the mixed-plastic-polyethylene composition of the present invention. The term “blend” as used herein may refer to a mixture of two or more components, wherein one of the components is polymeric. For example, the blend of linear low-density polyethylene (LLDPE) may refer to a blend comprising at least 90 wt.% of a reactor made linear low density polyethylene material (e.g. as one or the only polymeric component). This linear low density polyethylene material is a virgin material, which has not already been recycled. In general, the blend can be prepared by mixing the two or more components. Suitable mixing procedures are known in the art.

[0022] For the purposes of the present description and of the subsequent claims, the term “mixed-plastic- polyethylene” indicates a polymer material including predominantly units derived from ethylene apart from other polymeric ingredients of arbitrary nature. Such polymeric ingredients may for example originate from monomer units derived from alpha olefins such as propylene, butylene, hexene, octene, and the like, styrene derivatives such as vinylstyrene, substituted and unsubstituted acrylates, substituted and unsubstituted methacrylates. Said polymeric materials can be identified in the mixed-plastic polyethylene composition by means of quantitative13C{ 1H} NMR measurements.

[0023] Within the meaning of this invention, the term “jacketing material” or “jacketing layer” refers to a material or layer that is used in cable jacketing / cable coating applications for electrical / telephone / telecommunications cables. These materials are required to show good ESCR properties, such as a Bell test failure time of > 1000 hours, such as >2000 hours, preferably > 3000 hours.

[0024] If not indicated otherwise “%” refers to weight-%.

[0025] Unless clearly indicated otherwise, use of the terms “a,” “an,” and the like refers to one or more.

[0026] The term “comprises” or “comprising" as used herein has an open meaning and includes the semi-closed term “consisting essentially of’ and the closed term “consisting of’ and can be used interchangeably therewith.

[0027] Detailed Description

[0028] The headed sections below relate to all aspects of the invention, unless the context indicates otherwise.

[0029] Linear low-density polyethylene (LLDPE)

[0030] The invention relates to a composition that includes a blend of a linear low-density polyethylene (LLDPE). The blend of the LLDPE is preferably a blend of a virgin LLDPE. In general, recycled materials perform less well in functional tests such as the ESCR (Bell test failure time), SH modulus and Shore D tests than virgin materials or blends comprising virgin materials.

[0031] The blend of the LLDPE may comprise, or consist essentially of, one or more linear low-density polyethylenes (LLDPEs). It may be preferred that the blend of LLDPE comprises linear low-density polyethylene (LLDPE) as the only polymeric ingredient.

[0032] The blend of the LLDPE may comprise, or consist essentially of, a single LLDPE, preferably a single virgin LLDPE. Alternatively, the blend of the LLDPE may comprise, or consist essentially of, a plurality of LLDPEs. It is preferred that each LLDPE of the plurality of LLDPEs is a virgin LLDPE.

[0033] It is generally preferred that the blend of the LLDPE comprises, or consists essentially of, a single LLDPE. The LLDPE is typically a bimodal LLDPE. Such LLDPEs are commercially available or can be prepared by conventional methods known in the art.

[0034] Generally, the blend of the LLDPE comprises a total amount of LLDPE of at least 50.0 wt.% (e.g. from 50.0 to 99.5 wt.%), preferably at least 75.0 wt.% (e.g. from 75.0 to 99.0 wt.%), more preferably at least 85.0 wt.% (e.g. from 85.0 wt.% to 95.0 wt%), such as at least 90.0 wt.%, based on the total weight of the blend of the LLDPE.

[0035] Typically, the or each LLDPE is a natural, virgin linear low-density polyethylene (LLDPE).

[0036] The or each LLDPE in the blend of LLDPE may be commercially available or the blend of LLDPE itself may be commercially available.

[0037] The blend of LLDPE is typically suitable for a cable jacket. Some of the properties of the blend are described below.

[0038] The blend of LLDPE may have:

[0039] (i) a melt flow rate (ISO 1133-1, Method A, 2.16 kg, 190 °C) of from 0.10 to 1.5 g / 10 min, preferably from 0.12 to 1.2 g / 10 min, such as from 0.50 to 1.1 g / 10 min, more preferably 0.15 to 1.0 g / 10 min; and / or

[0040] (ii) a density of from 900 to <940 kg / m3, preferably from 910 to 939 kg / m3, more preferably from > 910 to 939 kg / m3, most preferably from 915 to 937 kg / m3. The blend of LLDPE is preferably different in composition from the blend of VLDPE.

[0041] In general, the blend of LLDPE has one or more, preferably all, of the following properties: a shear thinning index SHE 7 / 210 of from 25 to 45, more preferably from 30 to 40; a complex viscosity at the frequency of 300 rad / s, etasoo, of from 500 to 900 Pa-s, more preferably from 550 to 700 Pa-s; a complex viscosity at the frequency of 0.05 rad / s, etao.05, of from 12500 to 60000 Pa-s, more preferably from 15000 to 30000 Pa-s; a Shore D hardness (measured after 15 s according to ISO 868), i.e. Shore D 15 s, of from 42 to 52, more preferably of from 45 to 50, a Shore D hardness ( measured after 1 s according to ISO 868), i.e. Shore D 1 s, of from 48 to 58, more preferably of from 50 to 56, a Shore D hardness (measured after 3 s according to ISO 868), i.e. Shore D 3 s, of from 45 to 55, more preferably of from 47 to 53, a strain hardening modulus, SH modulus, of from 12.5 to 35.0 MPa, more preferably from 15.0 to 25.0 MPa, a Charpy notched impact strength at 23 °C, Charpy NIS 23°C, of from 50.0 to 100.0 kJ / m2, more preferably from 70.0 to 85.0 kJ / m2, a Charpy notched impact strength at 0 °C, Charpy NIS 0°C, of from 70.0 to 125.0 kJ / m2, more preferably from 85.0 to 110.0 kJ / m2, a flexural modulus of from 350 to 500 MPa, more preferably from 375 to 450 MPa (measured according to ISO 178), a tensile stress at break (25 mm / min, measured according to ISO 527-2) of from 15 to 40 MPa, more preferably from 20 to 30 MPa, a tensile strain at break (25 mm / min, measured according to ISO 527-2) of from 600 to 900 %, more preferably from 700 to 850 %, and / or an environmental stress crack resistance, ESCR, of at least 2500 hours, more preferably at least 3000 hours (measured according to EN-60811-406, method A).

[0042] The blend of LLDPE may comprise a pigment. Typically, the blend of LLDPE comprises a total amount of pigment of from 1.0 to 10.0 wt.%, such as from 5.0 to 10.0 wt.%, based on the total weight of the blend of LLDPE. It is preferred that the total amount of pigment is from 3.0 to 7.5 wt.%.

[0043] The pigment is preferably carbon black. More preferably, the blend of LLDPE may comprise carbon black as the only pigment. The presence of carbon black has an influence on the density of the blend of LLDPE. When the blend of LLDPE comprises carbon black, then preferably the blend has a density of from 910 to <940 kg / m3, more preferably from 920 to 939 kg / m3, most preferably from 925 to 937 kg / m3.

[0044] The blend of LLDPE may include, as a polymeric component, a copolymer of ethylene and one or more comonomer units selected from alpha-olefins having from 3 to 6 carbon atoms. It is preferred that the polymeric component is a copolymer of ethylene and 1 -butene or a copolymer of ethylene and 1 -hexene.

[0045] Alternatively, the blend of LLDPE may not comprise carbon black. When the blend of LLDPE does not comprise carbon black, then the density of the blend of LLDPE may be from 900 to 935 kg / m3, preferably from 910 to 930 kg / m3, most preferably from 915 to 925 kg / m3.

[0046] The blend of LLDPE may include a metal deactivator. The blend of LLDPE may include a metal deactivator in a total amount of from 0.5 to 5.0 wt.%, such as from 1 .0 to 5.0 wt.%, based on the total weight of the blend of LLDPE. It is preferred that the total amount of pigment is from 1.5 to 2.5 wt.%.

[0047] The metal deactivator may be a phenolic antioxidant. The phenolic antioxidant may be 2 ’ ,3 -bis[ [3 -[3 ,5 - di-tert-butyl-4-hydroxyphenyl]propionyl]propionohydrazide or 2,2’-oxamidobis-[ethyl-3-(3,5-di-tert- butyl-4-hydroxyphenyl)propionate] . The metal deactivator is used for the stabilization of polymers that come into contact with copper (e.g. during processing or long-term service). Such metal deactivators are commercially available (e.g. Irganox™ MD 1024 or Naugard™ XL-1).

[0048] Typically, the blend of LLDPE comprises a total amount of pigment of from 1 .0 to 10.0 wt.%, such as from 5.0 to 10.0 wt.%, based on the total weight of the blend of LLDPE. It is preferred that the total amount of pigment is from 3.0 to 7.5 wt.%.

[0049] Generally, the blend of LLDPE may comprise one or more additives. The additive may be selected from a stabilizer (e.g. an antioxidant agent), a metal scavenger, a UV stabilizer, an antistatic agent, a utilization agent (e.g. processing aid agent) and a combination of two or more thereof.

[0050] When the blend of LLDPE comprises an additive, then the total amount of additive is no more than 10 wt.%, more preferably no more than 9 wt.%, more preferably no more than 7 wt.%, based on the total weight of the blend of LLDPE. Cross-linked polyethylene (XLPE) recyclate

[0051] The invention relates to a composition that includes a total amount of 5.0 to 50.0 wt.% of a cross-linked polyethylene (XLPE) recyclate, based on a total weight of the mixed-plastic-poly ethylene composition. The XLPE recyclate has a mean particle size of 0.7 mm to 25.0 mm.

[0052] Surprisingly, compounding an XLPE recyclate having a relatively high particle size with LLDPE provides a composition with excellent impact properties and flexibility. In particular, the flexibility of the composition can be better than the flexibility of a composition comprising virgin LLDPE as the only polymeric ingredient.

[0053] The XLPE recyclate typically has a mean particle size of 1.0 mm to 20.0 mm, preferably 1.5 mm to 18.0 mm, such as 2.0 to 15.0 mm, more preferably 2.5 to 10.0 mm such as 3.0 to 8.0 mm, 3.0 to 6.0 mm, 3.0 to 5.0 mm or 3.5 to 4.5 mm. The mean particle size may be obtained by sieve-grinding. The XLPE recyclate may be ground and sieved to a desired mean particle size. A grinding instrument equipped with a sieve plate for the desired particle size may be used. Using the sieve plate, particles over a certain size are discarded, whereas particles having a size less than the size rating of the sieve are collected.

[0054] The smaller the required particle size of the recyclates, the more energy and effort is required to obtain them, while larger particle sizes can be obtained more easily and in a more economically efficient way. However, the use of recyclates with a larger particle size often leads to processing problems or unacceptable material properties. The inventors have found that the compositions according to the present invention demonstrate an excellent balance between meeting the key requirements for jacketing applications on one hand while using XLPE recyclates with a relatively large diameter on the other.

[0055] Lor the avoidance of doubt, the XLPE recyclate is a recycled material. The XLPE recyclate does not comprise a virgin polymeric material.

[0056] The XLPE recyclate comprises, or may consist essentially of, cross-linked polyethylene (XLPE).

[0057] In general, the cross-linked polyethylene (XLPE) recyclate comprises at least 85.0 wt.% of cross-linked polyethylene (XLPE), preferably at least 90.0 wt.% of cross-linked polyethylene (XLPE), more preferably at least 95.0 wt.% of cross-linked polyethylene (XLPE), based on a total weight of the crosslinked polyethylene (XLPE) recyclate.

[0058] The cross-linked polyethylene may be prepared or obtained by cross-linking a polyethylene. The crosslinked polyethylene (XLPE) may be selected from a cross-linked polyethylene prepared or obtained by peroxide crosslinking (e.g. a peroxide cross-linked polyethylene), a cross-linked polyethylene prepared or obtained by irradiation crosslinking (e.g. an irradiation cross-linked polyethylene), a cross-linked polyethylene prepared or obtained by azo crosslinking (e.g. an azo cross-linked polyethylene) and a cross-linked polyethylene prepared or obtained by silane crosslinking (e.g. a silane cross-linked polyethylene). It is preferred that the cross-linked polyethylene (XLPE) is selected from a cross-linked polyethylene prepared or obtained by peroxide crosslinking, a cross-linked polyethylene prepared or obtained by irradiation crosslinking and a cross-linked polyethylene prepared or obtained by azo crosslinking. More preferably, the cross-linked polyethylene (XLPE) is a cross-linked polyethylene prepared or obtained by peroxide crosslinking.

[0059] Typically, the cross-linked polyethylene (XLPE) is prepared or obtained from a polyethylene selected from a high-density polyethylene (e.g. XLPE derived from HDPE), a low-density polyethylene (e.g. XLPE derived from LDPE) and a combination thereof. It is preferred that the cross-linked polyethylene (XLPE) is prepared or obtained from a thermoplastic polyethylene, preferably a thermoplastic polyethylene selected from a high-density polyethylene (e.g. XLPE derived from HDPE) and a low- density polyethylene (e.g. XLPE derived from LDPE).

[0060] The low-density polyethylene may be a linear low-density polyethylene (e.g. the XLPE is derived from LLDPE).

[0061] In one example, the cross-linked polyethylene (XLPE) is prepared or obtained from a high-density polyethylene.

[0062] In another example, the cross-linked polyethylene (XLPE) is prepared or obtained from a low-density polyethylene. Where the XLPE in the recyclate was prepared from a LDPE, the combination of the XLPE recyclate and a virgin LLDPE was surprisingly found to provide a composition with excellent impact properties and flexibility. In particular, the flexibility of the composition can be better than the flexibility of a composition comprising the virgin LLDPE as the only polymeric ingredient.

[0063] In general, the cross-linked polyethylene (XLPE) recyclate may include other materials in addition to the cross-linked polyethylene (XLPE) polymer.

[0064] The cross-linked polyethylene (XLPE) recyclate may comprise a residual polymer selected from low density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE) and a mixture of two or more thereof. The residual polymer may be a natural polymer. When the cross-linked polyethylene (XLPE) recyclate comprises a residual polymer, then the total amount of residual polymer is from 0.1 to 15.0 wt.%, preferably 0.5 to 10.0 wt.%, more preferably 1.0 to 5.0 wt.%, based on the total weight of the cross-linked polyethylene (XLPE) recyclate.

[0065] The cross-linked polyethylene (XLPE) recyclate may comprise a pigment. Typically, the cross-linked polyethylene (XLPE) recyclate comprises a total amount of pigment of from 0. 1 to 10.0 wt.%, such as from 0.5 to 5.0 wt.%, based on the total weight of the cross-linked polyethylene (XLPE) recyclate. It is preferred that the total amount of pigment is from 1.0 to 5.0 wt.%.

[0066] Typically, the pigment is carbon black. The cross-linked polyethylene (XLPE) recyclate may comprise carbon black as the only pigment.

[0067] The cross-linked polyethylene (XLPE) recyclate may comprise one or more metals. The one or more metals may be selected from copper, aluminium and a mixture thereof. Metals may be present if the cross-linked polyethylene (XLPE) recyclate is produced from a cable.

[0068] When the cross-linked polyethylene (XLPE) recyclate comprises one or more metals, then the crosslinked polyethylene (XLPE) recyclate may comprise a total amount of the one or more metals of from 0.1 to 10.0 wt.%, preferably 0.5 to 5.0 wt.%, more preferably 1.0 to 2.5 wt.%, based on the total weight of the cross-linked polyethylene (XLPE) recyclate.

[0069] In general, the cross-linked polyethylene (XLPE) recyclate may include carbon ash. The total amount of carbon ash (e.g. ash content) may be from 0.01 to 0.50 wt.%, such as from 0.02 to 0.20 wt.%, preferably from 0.03 to 0.10 wt.%, based on the total weight of the cross-linked polyethylene (XLPE) recyclate.

[0070] The cross-linked polyethylene (XLPE) recyclate may include one or more impurities. The one or more impurities may be selected from sulfur, ethyl acetate and a mixture thereof.

[0071] When the cross-linked polyethylene (XLPE) recyclate comprises one or more impurities, then the total amount of the one or more impurities is no more than 1.0 wt.%, more preferably no more than 0.5 wt.%, more preferably no more than 0.1 wt.%, based on the total weight of the cross-linked polyethylene (XLPE) recyclate. The cross-linked polyethylene (XLPE) recyclate may have a gel content of from 70 to 98 %, preferably from 75 to 95%. The gel content can be measured using the test method described below in the example.

[0072] Very low-density polyethylene (VLDPE)

[0073] The mixed-plastic-polyethylene composition of the invention may further comprise a very low-density polyethylene (VLDPE).

[0074] A surprising synergy was observed between the very low-density polyethylene (VLDPE) and the relative large particles of the XLPE recyclate. The resulting compositions can provide better flexibility and impact strength, particularly at -20°C, than the corresponding properties of a composition comprising the virgin LLDPE as the only polymeric ingredient. These improvement were particularly advantageous when the XLPE recyclate comprises mainly XLPE prepared from a LDPE.

[0075] The very low-density polyethylene (VLDPE) is typically an elastomer, preferably the VLDPE is a plastomer. According to IUPAC, an elastomer is a polymer that displays rubber-like elasticity. A plastomer shows both plasticity and elasticity. The VLDPE is commercially available under the tradenames Queo™, Exact™, Engage™ and others.

[0076] The VLDPE may be included in the mixed-plastic-polyethylene composition or provided in the process for preparing the mixed-plastic-polyethylene composition in the form of a blend of a very low-density polyethylene (VLDPE). In general, the blend of the VLDPE may comprise a single VLDPE, preferably the VLDPE is the only polymeric ingredient of the blend of the VLDPE.

[0077] Generally, the blend of VLDPE comprises a total amount of VLDPE of at least 75.0 wt.% (e.g. from 75.0 to 99.5 wt.%), preferably at least 85.0 wt.% (e.g. from 85.0 to 99.0 wt.%), more preferably at least 95.0 wt.% (e.g. from 95.0 wt.% to 99.0 wt%), based on the total weight of the blend of VLDPE.

[0078] It is generally preferred that the VLDPE is a virgin very low-density polyethylene (VLDPE). The VLDPE may be a natural virgin very low-density polyethylene (VLDPE).

[0079] The blend of VLDPE may comprise, as a polymeric component, a copolymer of ethylene and one or more comonomer units selected from alpha-olefins having from 3 to 12 carbon atoms. It is preferred that the copolymer is a copolymer of ethylene and 1 -butene or a copolymer of ethylene and 1 -octene, more preferably a copolymer of ethylene and 1 -octene. The VLDPE is typically produced in a solution polymerization process using a metallocene catalyst, as known in the art.

[0080] The VLDPE or the blend of VLDPE typically has:

[0081] (i) a melt flow rate (ISO 1133, 2. 16 kg, 190 °C) of from 1.0 to 6.0 g / lOmin, preferably from 1.5 to 5.0 g / 10 min, most preferably from 2.0 to 4.5 g / 10 min; and / or

[0082] (ii) a density of from 850 to 910 kg / m3, preferably from 860 to 900 kg / m3, most preferably from 870 to 890 kg / m3.

[0083] The VLDPE or the blend of VLDPE preferably has one or more, more preferably all, of the following properties: a melting temperature, Tm, of from 65 to 85°C, more preferably from 70 to 80°C (measured according to ISO 11357-3); a flexural modulus of from 2.5 MPa to 15.0 MPa, more preferably from 5.0 MPa to 12.0 MPa (measured on moulded plaques, according to ISO 178); a tensile strength (measured on moulded plaques, according to ISO 527-2) of from 5.0 to 35.0 MPa, more preferably from 10.0 to 30.0 MPa, even more preferably from 15.0 to 25.0 MPa; elongation at break (measured on moulded plaques, according to ISO527-2) of from 500 to 1000%, more preferably from 600 to 950%, even more preferably from 750 to 850%; and / or a Shore D hardness (measured after 1 s according to ISO 868), i.e. Shore D 1 s, of from 10 to 30, more preferably from 15 to 25.

[0084] When the VLDPE is present as a blend, then the blend of VLDPE may comprise a pigment. The pigment may be carbon black. More preferably, the blend of VLDPE comprises carbon black as the only pigment

[0085] Typically, the blend of VLDPE comprises a total amount of pigment of from 0.5 to 5.0 wt.%, such as from 1.0 to 2.5 wt.%, based on the total weight of the blend of VLDPE.

[0086] Alternatively, the blend of VLDPE does not comprise carbon black.

[0087] Generally, the blend of VLDPE may comprise one or more additives. The additive may be selected from a stabilizer (e.g. an antioxidant agent), a metal scavenger, a UV stabilizer, an antistatic agent, a utilization agent (e.g. processing aid agent) and a combination of two or more thereof. When the blend of VLDPE comprises an additive, then the total amount of additive is no more than 10 wt.%, more preferably no more than 9 wt.%, more preferably no more than 7 wt.%, based on the total weight of the blend of VLDPE.

[0088] Mixed-plastic-polyethylene composition

[0089] The present invention seeks to provide a mixed-plastic-polyethylene composition comprising a crosslinked polyethylene (XLPE) recy elate. The XLPE recyclate is preferably from post-consumer waste or post-industrial waste. The mixed-plastic-polyethylene composition provides a beneficial balance of ESCR, impact strength and flexural modulus at levels which are suitable for jacketing applications.

[0090] The mixed-plastic-polyethylene composition as described herein is especially suitable for wire and cable applications, such as jacketing applications.

[0091] The mixed-plastic-polyethylene composition comprises a blend of linear low-density polyethylene (LLDPE). The mixed-plastic-polyethylene composition may comprise a total amount of from 50.0 to 95.0 wt.%, such as from 55.0 to 90.0 wt.%, more preferably from 55.0 to 80.0 wt.%, and even more preferably from 65.0 to 75.0 wt.%, of the blend of LLDPE, based on the total weight of the mixed- plastic-polyethylene composition.

[0092] The mixed-plastic-polyethylene composition comprises an amount, preferably a total amount, of 5.0 to 50.0 wt.% of a cross-linked polyethylene (XLPE) recyclate, based on a total weight of the mixed-plastic- polyethylene composition. It is preferred that the total amount of the cross-linked polyethylene (XLPE) recyclate is from 10.0 to 45.0 wt.%, such as from 20.0 to 45.0 wt.%, more preferably from 20.0 to 40.0 wt.%, and even more preferably from 25.0 to 35.0 wt.%, based on the total weight of the mixed-plastic- polyethylene composition.

[0093] The amount of cross-linked polyethylene (XLPE) recyclate that is included in the mixed-plastic- polyethylene composition may depend on the application.

[0094] In one example, the mixed-plastic-polyethylene composition comprises the cross-linked polyethylene (XLPE) recyclate is in a total amount of at least 20.0 wt.%, preferably 20.0 to 40.0 wt.% (e.g. 20.0 to 30.0 wt.%), more preferably 25.0 to 35.0 wt.%, based on the total weight of the mixed-plastic- polyethylene composition. A relatively large amount of the XLPE recyclate can be included when the composition is for use as an inner jacket because the surface finish is unimportant. In another example, the mixed-plastic-polyethylene composition comprises the cross-linked polyethylene (XLPE) recyclate is in an amount of less than 20.0 wt.%, preferably 7.5 to 17.5 wt.%, more preferably 10.0 to 15.0 wt.%, based on the total weight of the mixed-plastic-polyethylene composition. A smaller amount of the XLPE recyclate can be included when the composition is for use as an outer jacket where the surface finish is important.

[0095] The mixed-plastic-ethylene composition may or may not include a very low-density polyethylene (VLDPE).

[0096] When the mixed-plastic-ethylene composition includes a very low-density polyethylene (VLDPE), then the mixed-plastic-ethylene composition comprises a total amount of 0.5 to 20.0 wt.% of the very low- density polyethylene (VLDPE), based on the total weight of the mixed-plastic-polyethylene composition. The mixed-plastic-ethylene composition preferably comprises the very low-density polyethylene (VLDPE) in a total amount of 1.0 to 15.0 wt.%, more preferably 2.5 to 10.0 wt.%, based on the total weight of the mixed-plastic-polyethylene composition.

[0097] When the mixed-plastic-ethylene composition includes a very low-density polyethylene (VLDPE), then the mixed-plastic-polyethylene composition may comprise a total amount of from 30.0 to 94.5 wt.% of the blend of LLDPE, based on the total weight of the mixed-plastic-polyethylene composition. It is preferred that the total amount of the blend of LLDPE is from 50.0 to 94.5 wt.%, such as from 55.0 to 90.0 wt.%, more preferably from 55.0 to 80.0 wt.%, and even more preferably from 60.0 to 75.0 wt.%, based on the total weight of the mixed-plastic-polyethylene composition.

[0098] When the mixed-plastic-ethylene composition includes a very low-density polyethylene (VLDPE), then the mixed-plastic-ethylene composition may have a ratio by weight of the cross-linked polyethylene (XLPE) recyclate to the very low-density polyethylene (VLDPE) of from 12:1 to 1:1, preferably from 10: 1 to 2: 1, more preferably from 8: 1 to 4: 1.

[0099] The mixed-plastic-ethylene composition typically has a melt flow rate (ISO 1133, 2.16 kg, 190 °C) of from 0.1 to 2.0 g / 10 min, preferably from 0.2 to 1.7 g / 10 min, most preferably from 0.3 to 1.5 g / 10 min.

[0100] In general, the mixed-plastic-polyethylene composition preferably has a flexural modulus of from 250 to 450 MPa, preferably from 260 to 400 MPa, most preferably from 270 to 365 MPa.

[0101] The mixed-plastic polyethylene composition preferably has a Charpy Notched Impact Strength at -20 °C of from 60 to 120 kJ / m2, preferably from 65 to 110 kJ / m2, most preferably from 70 to 105 kJ / m2. Further, the mixed-plastic polyethylene composition preferably has a Charpy Notched Impact Strength at 0 °C of from 20 to 120 kJ / m2, preferably from 35 to 110 kJ / m2, most preferably from 60 to 100 kJ / m2.

[0102] Further, the mixed-plastic polyethylene composition preferably has an ESCR (Bell test failure time) of at least 2000 hours, preferably at least 3000 hours and still more preferably at least 4000 hours and most preferably at least 5000 hours. The upper limit of the ESCR can be as high as 30000 hours, usually up to 20000 hours.

[0103] It is further preferred that that the mixed-plastic polyethylene composition preferably has a Shore D hardness, measured according to ISO 868 with a measuring time of 1 s, Shore D Is, of from 42.0 to 60.0, preferably from 44.0 to 58.0, most preferably from 46.0 to 57.0.

[0104] It is further preferred that the mixed-plastic polyethylene composition has a pressure deformation of not more than 42%, preferably not more than 38%, most preferably not more than 35%. The lower limit is usually at least 5%, preferably at least 10%.

[0105] Still further, the mixed-plastic polyethylene composition preferably has a water content of preferably not more than 350 ppm, preferably not more than 330 ppm, most preferably not more than 320 ppm. The lower limit is usually at least 15 ppm, preferably at least 25 ppm.

[0106] The mixed-plastic-polyethylene composition may include further components apart from the blend of LLDPE, the XLPE recyclate and, when present, the VLDPE.

[0107] The mixed-plastic-polyethylene composition may comprise one or more additives. The one or more additives can be present in the composition in a total amount of 10 wt.% or below, more preferably 9 wt.% or below, more preferably 7 wt.% or below, based on the total weight of the mixed-plastic- polyethylene composition.

[0108] The one or more additives may be an additive for utilization with polyolefins, such as one or more additives selected from a stabilizer (e.g. an antioxidant agent), a metal scavenger, a UV stabilizer, an antistatic agent, a utilization agent and a combination of two or more thereof.

[0109] In one embodiment, the mixed-plastic-polyethylene composition comprises carbon black or a pigment, preferably the composition comprise carbon black. When the mixed-plastic-polyethylene composition included carbon black or a pigment, then the total amount of carbon black or pigment is not more than 5 wt.%, preferably not more than 3 wt.%, based on the total weight of the mixed-plastic-polyethylene composition. The lower limit of carbon black or pigment is usually at least 1.0 wt.%, preferably at least 2.0 wt.%.

[0110] In another embodiment, the mixed-plastic-polyethylene composition does not comprise carbon black. The mixed-plastic-polyethylene composition may be a natural mixed-plastic-polyethylene composition.

[0111] In another embodiment, the mixed-plastic-polyethylene composition does not comprise a pigment. The mixed-plastic-polyethylene composition may be a natural mixed-plastic-polyethylene composition.

[0112] Article

[0113] The present application is further directed to an article comprising the mixed-plastic-polyethylene composition as described above.

[0114] The article may be used in jacketing applications i.e. for a cable jacket.

[0115] The article according to the present invention is particularly suitable as an inner cable jacket. Inner cable jacket layers provide an added layer of protection, additional safety to the cable components, from elements like; weather, water, and chemicals but also prevent pinching, splitting, cutting, or breaking of any kind to the cable upon accidental crashes or impacts on the cable. Inner cable jacket layers provide an excellent second line of defence but do not have to fulfil the same strict smoothness requirements as outer cable jacket layers.

[0116] Preferably the article is a cable comprising at least one layer which comprises the mixed-plastic- polyethylene composition as described above.

[0117] Preferably, the cable comprising a layer such as a jacketing layer, which comprises the mixed-plastic- polyethylene composition as described above, has a cable shrinkage of not more than 1.5 %, preferably not more than 1.0 %, most preferably not more than 0.8 %. The lower limit is usually at least 0.1 %, preferably at least 0.2 %.

[0118] Further, the cable comprising a layer such as a jacketing layer, which comprises the mixed-plastic- polyethylene composition as described above, preferably has the following tensile properties: atensile strain at break, measured according to EN60811-501 on cable specimen, of from 400% to 700%, more preferably from 425% to 650%, most preferably 450 to 600%; and / or a tensile stress at break, measured according to EN60811-501 on cable specimen, of from 12 to 30 MPa, preferably from 14 to 27 MPa, most preferably from 16 MPa to 25 MPa.

[0119] All preferred aspects and embodiments as described above apply for the article.

[0120] Process

[0121] The present invention also relates to a process for preparing the mixed-plastic-polyethylene composition as defined above or below.

[0122] The process includes a) providing a blend of linear low-density polyethylene (LLDPE). The process may include a) providing an amount, preferably a total amount, of from 50.0 to 95.0 wt.%, such as from 55.0 to 90.0 wt.%, more preferably from 55.0 to 80.0 wt.%, and even more preferably from 65.0 to 75.0 wt.%, of the blend of LLDPE, based on the total weight of the mixed-plastic-polyethylene composition.

[0123] The process comprises providing a total amount 5.0 to 50.0 wt.% of a cross-linked polyethylene (XLPE) recyclate, based on a total weight of the mixed-plastic-polyethylene composition. It is preferred that the total amount of the cross-linked polyethylene (XLPE) recyclate is from 10.0 to 45.0 wt.%, such as from 20.0 to 45.0 wt.%, more preferably from 20.0 to 40.0 wt.%, and even more preferably from 25.0 to 35.0 wt.%, based on the total weight of the mixed-plastic-polyethylene composition.

[0124] In one example, the process comprises providing the cross-linked polyethylene (XLPE) recyclate is in a total amount of at least 20.0 wt.%, preferably 20.0 to 40.0 wt.% (e.g. 20.0 to 30.0 wt.%), more preferably 25.0 to 35.0 wt.%, based on the total weight of the mixed-plastic-polyethylene composition.

[0125] In another example, the process comprises providing the cross-linked polyethylene (XLPE) recyclate is in an amount of less than 20.0 wt.%, preferably 7.5 to 17.5 wt.%, more preferably 10.0 to 15.0 wt.%, based on the total weight of the mixed-plastic-polyethylene composition.

[0126] As a general feature of the process, the step of providing a cross-linked polyethylene (XLPE) recyclate having a mean particle size of 0.7 mm to 25.0 mm or a mean particle size as defined herein may include grinding particles of the cross-linked polyethylene (XLPE) recyclate to obtain a mean particle size of 0.7 mm to 25.0 mm or a mean particle size as defined herein. It is preferred that this step includes grinding and sieving particles of the cross-linked polyethylene (XLPE) recyclate to obtain a mean particle size of 0.7 mm to 25.0 mm or a mean particle size as defined herein. When the mixed-plastic-polyethylene composition includes a very low-density polyethylene (VLDPE), then the process may further comprise: c) providing a very low-density polyethylene (VLDPE); and d) melting and mixing the blend of linear low-density polyethylene (LLDPE), the crosslinked polyethylene (XLPE) recyclate and the very low-density polyethylene (VLDPE) in an extruder, optionally a twin screw extruder.

[0127] In addition to the step of providing very low-density polyethylene (VLDPE), the melting and mixing step of the process of the invention also includes the very low-density polyethylene (VLDPE).

[0128] The process may comprise providing a very low-density polyethylene (VLDPE) in an amount, preferably a total amount, of 0.5 to 20.0 wt.%, based on the total weight of the mixed-plastic- polyethylene composition. The total amount is preferably 1.0 to 15.0 wt.%, more preferably 2.5 to 10.0 wt.%, based on the total weight of the mixed-plastic-polyethylene composition.

[0129] When the process includes a very low-density polyethylene (VLDPE), then the process may comprises providing the cross-linked polyethylene (XLPE) recyclate and the very low-density polyethylene (VLDPE) in a ratio by weight (e.g. of the cross-linked polyethylene (XLPE) recyclate to the very low- density polyethylene (VLDPE)) of from 12: 1 to 1 : 1, preferably from 10: 1 to 2: 1, more preferably from 8: l to 4: l.

[0130] In general, the process includes a step of melting and mixing the blend of linear low-density polyethylene (LLDPE), the cross-linked polyethylene (XLPE) recyclate and, when present, the very low-density polyethylene (VLDPE) in an extruder. It is preferred that the extruder is a twin screw extruder.

[0131] The process of the invention (all aspects) may include a step of pelletizing the obtained mixed-plastic- polyethylene composition.

[0132] All preferred aspects, definitions and embodiments as described above shall also hold for the process.

[0133] Use

[0134] The present invention relates to the use of a mixed-plastic-polyethylene composition as defined above or below for producing a cable, such as a cable layer, preferably a cable jacket, more preferably a cable jacketing layer. In one example, the invention relates to the use of a mixed-plastic-polyethylene composition for producing an inner cable jacket. The cross-linked polyethylene (XLPE) recyclate is in a total amount of at least 20.0 wt.%, preferably 20.0 to 40.0 wt.% (e.g. 20.0 to 30.0 wt.%), more preferably 25.0 to 35.0 wt.%, based on the total weight of the mixed-plastic-polyethylene composition.

[0135] In another example, the invention relates to the use of a mixed-plastic-polyethylene composition for producing an outer cable jacket. The cross-linked polyethylene (XLPE) recyclate is in an amount of less than 20.0 wt.%, preferably 7.5 to 17.5 wt.%, more preferably 10.0 to 15.0 wt.%, based on the total weight of the mixed-plastic-polyethylene composition.

[0136] All preferred aspects, definitions and embodiments as described above are also applicable to the use.

[0137] Examples

[0138] 1. Materials

[0139] Borstar™ LE8707 is a commercially available black bimodal linear low density polyethylene (LLDPE) jacketing compound, which is available from Borealis™. LE8707 was used as a virgin reference composition. LE8707 was compounded with a metal deactivator (AO600).

[0140] Recyclate 1 obtained from a commercial cable producer. This recyclate is a mixture of natural LDPE, LLDPE, MDPE, HDPE and carbon black with some traces of Cu and Al. The obtained flakes of the recyclate 1 had a mean particle size of ~7-9 mm. Internal analysis indicated only small traces of metals. LTIR indicated LDPE as the main polymer with a small presence of ethyl acrylate. Gel content of the batch used in the examples was 80%.

[0141] Recyclate 2 was obtained from a commercial pipe production facility. Waste is based on pipe collection. The obtained flakes of the recyclate 2 had a mean particle size of 8-12mm. Recyclate 2 was found to contain high purity HDPE with very low traces of metals. Gel content of the batch used in the examples was 93%.

[0142] AO600 (Irganox™ MD 1024) was added to all compositions to minimize potential polymer oxidation due to the transition metal traces included in the recy elates.

[0143] Queo™ 8203 (CAS No. 26221-73-8) is a commercially available product from Borealis™. It is an ethylene based 1 -octene plastomer produced in a solution polymerisation process using a metallocene catalyst. Queo™ 8203 has a density (23°C) of 882 kg / m3, a melt flow rate (190°C / 2.16 kg) of 3 g / 10 min, a melting temperature (DSC) of 74°C, and a flexural modulus of 24 MPa (measured on moulded plaques, ISO 178).

[0144] Grinding was performed to reduce the large particle size of the flakes for both the recyclate 1 and 2, to obtain a mean particle size of 4 mm. Compositions were prepared via melt on compounding unit ZSK. Compounding was made on ZSK 18. Compounding temperature was in the range of 200°C. The polymer melt mixture was pelletized. The compositions that were prepared are shown in Table A and were tested as described below.

[0145] Table A: Compositions

[0146] It was found that the XLPE recyclates could be easily compounded, surprisingly even with a relatively large particle size of 4 mm.

[0147] 2. Test Methods a) Tape extrusion

[0148] All compositions were extruded at 180°C and 210°C with no improvement in the finished surface. A water cooling rolls Collin Teach-line CR72T was attached to the tape extruder to further improve the finish surface all the tapes. Rolls temperature were optimized to 60°C. b) Mechanical properties

[0149] For tensile testing, dog bone specimens of 5A are prepared according to ISO 527-2 / 5A by die cutting from compression moulded plaques of 2mm’ thickness. All specimens are conditioned for at least 16 hours at 23 °C and 50% relative humidity before testing.

[0150] Tensile properties are measured according to ISO 527-1 / 2 at 23°C and 50% relative humidity with Alwetron R24, IkN load cell. Tensile testing speed is 50mm / min, grip distance is 50mm and gauge length is 20mm. c) Impact strength

[0151] The impact strength is determined as Charpy Notched Impact Strength according to ISO 179-1 eA at +23 °C and at 0 °C on compression moulded specimens of 80 x 10 x 4 mm prepared according to ISO 17855-2. d) ESCR (Bell test, h)

[0152] By the term ESCR (environmental stress cracking resistance) is meant the resistance of the material to crack formation under the action of mechanical stress and a reagent in the form of a surfactant. The ESCR was determined in accordance with EN-60811-406, method A. The reagent employed is 10 weight% Igepal CO 630 in water. Each material was pressed at 165°C to a thickness of 3.00 to 3.30 mm. e) Melt Flow Rate (MFR)

[0153] Melt flow rates were measured with a load of 5.0 kg (MFR5) at 190°C as indicated. The melt flow rate is that quantity of polymer in grams which the test apparatus standardized to ISO 1133 extrudes within 10 minutes at a temperature of 190°C under a load of 5.0 kg. f) Shore D hardness

[0154] Shore D hardness was determined according to ISO 868 on moulded specimen with a thickness of 4 mm. The shore hardness is determined after 1 sec, after the pressure foot is in firm contact with the test specimen. The sample is compression moulded according to ISO 17855-2 and milled into specimens of 80x10x4 mm. g) Flexural modulus

[0155] Flexural modulus was determined according to ISO 178:2010. The test specimens were extruded tapes with a thickness of 2 mm. The length of the span between the supports was 64 mm, the test speed was 2 mm / min and the load cell was 100 N. The equipment used was an Alwetron TCT 10. The specimen were conditioned for minimum 16 hours at 23+ / -2°C and 50% relative humidity prior testing. h) Tear resistance

[0156] Tear resistance was measured on compression moulded plaques of 1 mm thickness according to BS 6469 section 99.1. A test piece with a cut is used to measure the tear force by means of a tensile testing machine. The tear resistance is calculated by dividing the maximum force needed to tear the specimen by its thickness. i) Mechanical properties after ageing

[0157] Dog bone specimens of 5A were prepared according to ISO 527-2 / 5Aby die cutting from compression moulded plaques of 2mm’ thickness the 5A specimens are kept at 110 °C in a cell oven for 14 days (336 hours). All specimens are conditioned for at least 16 hours at 23 °C and 50% relative humidity before testing. The mechanical properties were then measured as described above. j) Gel content

[0158] The degree of crosslinking or gel content was measured by decalin extraction according to ASTM D 2765-16, Method A on the crosslinked material. This method determines the amount of the decalin- insoluble fraction in cross-linked polyethylene.

[0159] The test results for each of the compositions are shown in Table B.

[0160] Table B: Test results

[0161] All of the compositions of the present invention met the key requirements for cable jacketing applications, including ESCR >2000h, despite the relatively large particle size of the XLPE recyclates.

[0162] The compositions according to the present invention demonstrate an excellent balance between meeting the key requirements for jacketing applications while using XLPE recyclates with a relatively large diameter which can be obtained more easily and in a more economically efficient way. Example 2 and 4 also demonstrated a surprising synergy between the addition of the recyclates and the VLDPE because both the flexibility and the impact strength at -20°C improved significantly compared to Example 3 and 4, respectively. In case of Example 2, the impact strength and flexibility was even better than the reference composition containing the virgin LE8707 polymer as the only polymer ingredient.

[0163] The results also show that composition containing Recyclate 1 (Examples 1 and 2) provide better properties than the compositions containing Recyclate 2 (Examples 3 and 4).

Claims

Claims1. A mixed-plastic-polyethylene composition comprising: a) a blend of linear low-density polyethylene (LLDPE); and b) 5.0 to 50.0 wt.% of a cross-linked polyethylene (XLPE) recyclate, based on a total weight of the mixed-plastic-polyethylene composition; wherein the cross-linked polyethylene (XLPE) recyclate has a mean particle size of 0.7 mm to 25.0 mm.

2. A mixed-plastic-polyethylene composition obtained or obtainable by blending and extruding components comprising: a) a blend of linear low-density polyethylene (LLDPE); and b) 5.0 to 50.0 wt.% of a cross-linked polyethylene (XLPE) recyclate, based on a total weight of the mixed-plastic-polyethylene composition; wherein the cross-linked polyethylene (XLPE) recyclate has a mean particle size of 0.7 mm to 25.0 mm.

3. The mixed-plastic-polyethylene composition according to claim 1 or claim 2, wherein the XLPE recyclate has a mean particle size of 1.0 mm to 20.0 mm, preferably of 1.5 mm to 18.0 mm, more preferably of 2.5 to 10.0 mm.

4. The mixed-plastic-polyethylene composition according to any one of claims 1 to 3, wherein the cross-linked polyethylene (XLPE) recyclate comprises at least 85.0 wt.% of cross-linked polyethylene (XLPE), preferably at least 90.0 wt.% of cross-linked polyethylene (XLPE), more preferably at least 95.0 wt.% of cross-linked polyethylene (XLPE), based on a total weight of the cross-linked polyethylene (XLPE) recyclate.

5. The mixed-plastic-polyethylene composition according to any one of claims 1 to 4, wherein the cross-linked polyethylene (XLPE) recyclate comprises a cross-linked polyethylene (XLPE), wherein the cross-linked polyethylene (XLPE) is selected from a cross-linked polyethylene obtained by peroxide crosslinking, a cross-linked polyethylene obtained by irradiation crosslinking, a cross-linked polyethylene obtained by azo crosslinking and a cross-linked polyethylene obtained by silane crosslinking, preferably selected from a cross-linked polyethylene obtainable by peroxide crosslinking, a cross-linked polyethylene obtainable by irradiation crosslinking and a cross-linked polyethylene obtainable by azo crosslinking.

6. The mixed-plastic-polyethylene composition according to any one of claims 1 to 5, wherein the cross-linked polyethylene (XLPE) recyclate comprises a cross-linked polyethylene (XLPE) obtained from a thermoplastic polyethylene selected from a high-density polyethylene and a low-density polyethylene, preferably the cross-linked polyethylene (XLPE) recyclate comprises a cross-linked polyethylene (XLPE) obtained from a thermoplastic low-density polyethylene.

7. The mixed-plastic-polyethylene composition according to any one of claims 1 to 6, wherein the cross-linked polyethylene (XLPE) recyclate comprises one or more metals in a total amount of up to 1.0 wt.%, preferably a total amount of up to 0.5 wt.%, more preferably a total amount of up to 0.1 wt.%, based on a total weight of the cross-linked polyethylene (XLPE) recyclate.

8. The mixed-plastic-polyethylene composition according to any one of claims 1 to 7, further comprising a very low-density polyethylene (VLDPE).

9. The mixed-plastic-polyethylene composition according to claim 8, wherein the very low-density polyethylene (VLDPE) is in an amount of 1.0 to 15.0 wt.%, preferably 2.5 wt.% to 10 wt.%, based on the total weight of the mixed-plastic-poly ethylene composition.

10. The mixed-plastic-polyethylene composition according to claim 8 or claim 9, wherein the very low-density polyethylene (VLDPE) comprises a copolymer of ethylene and one or more comonomer units selected from alpha-olefins having from 3 to 12 carbon atoms, preferably a copolymer of ethylene and 1 -butene or a copolymer of ethylene and 1 -octene, more preferably a copolymer of ethylene and 1- octene.

11. The mixed-plastic-polyethylene composition according to any one of claims 1 to 10, wherein the cross-linked polyethylene (XLPE) recyclate is in an amount of at least 20.0 wt.%, preferably 20.0 to 40.0 wt.%, more preferably 25.0 to 35.0 wt.%, based on the total weight of the mixed-plastic- polyethylene composition.

12. The mixed-plastic-polyethylene composition according to any one of claims 1 to 10, wherein the cross-linked polyethylene (XLPE) recyclate is in an amount of less than 20.0 wt.%, preferably 7.5 to 17.5 wt.%, more preferably 10.0 to 15.0 wt.%, based on the total weight of the mixed-plastic- polyethylene composition.

13. An article comprising the mixed-plastic-polyethylene composition according to any one of claims 1 to 12, preferably wherein the article is a cable comprising at least one layer comprising themixed-plastic-polyethylene composition according to any one of claims 1 to 12, more preferably wherein the article is a cable comprising a jacketing layer comprising the mixed-plastic-polyethylene composition according to any one of the preceding claims, and even more preferably wherein the article is a cable comprising a jacketing layer, wherein the jacketing layer has an inner layer comprising the mixed-plastic-polyethylene composition according to claim 11 and / or an outer layer comprising the mixed-plastic-polyethylene composition according to claim 12.

14. A process for preparing the mixed-plastic-polyethylene composition according to any one of claims 1 to 12, comprising: a) providing a blend of linear low-density polyethylene (LLDPE); b) providing a cross-linked polyethylene (XLPE) recyclate in an amount of 5.0 to 50.0 wt.% of, based on a total weight of the mixed-plastic-polyethylene composition, wherein the crosslinked polyethylene (XLPE) recyclate has a mean particle size of 0.7 mm to 25.0 mm; c) melting and mixing the blend of linear low-density polyethylene (LLDPE) and the cross-linked polyethylene (XLPE) recyclate in an extruder, optionally a twin screw extruder; and optionally d) pelletizing the obtained mixed-plastic-polyethylene composition.

15. Use of a mixed-plastic-polyethylene composition according to any one of claims 1 to 12 for producing a cable, preferably a cable jacket, more preferably an inner cable jacket.

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