UPGRADED POLYETHYLENE FOR JACKETING

Abstract

Mixed-plastic-polyethylene composition having a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 0.9 g/10 min; and a density of from 956 kg/m.sup.3 to 970 kg/m.sup.3, preferably from 958 to 968 kg/m.sup.3.

Claims

1. A mixed-plastic-polyethylene composition comprising a mixed-plastic-polyethylene primary recycling blend (A), the mixed-plastic-polyethylene composition having a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 0.9 g/10 min; a density of from 956 kg/m.sup.3 to 970 kg/m.sup.3; the mixed-plastic-polyethylene composition comprising a total amount of ethylene units (C2 units) of from 90.0 to 95 wt.-%, and a total amount of continuous units having 3 carbon atoms corresponding to polypropylene (continuous C3 units) of from 4.0 to 8.0 wt.-%, a total amount of units having 4 carbon atoms (C4 units) of from 1.00 to 2.00 wt.-%; with the total amounts of C2 units, continuous C3 units and units having 4 carbon atoms being based on the total weight amount of monomer units in the composition and measured according to quantitative .sup.13C{.sup.1H} NMR measurement, wherein the mixed-plastic-polyethylene composition is obtained by blending and extruding a. 10.0 to 70.0 wt.-% of a mixed-plastic-polyethylene primary recycling blend (A), wherein 100.0 wt.-% of the mixed-plastic-polyethylene primary blend (A) originates from post-consumer waste having a limonene content of from 0.10 to 500 ppm; and wherein the mixed-plastic-polyethylene primary recycling blend (A) has a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.4 to 1.3 g/10 min, a density of from 945 to 990 kg/m.sup.3; and a content of units derived from ethylene of 70.0 to 95.0 wt.-% as determined by quantitative .sup.13C{.sup.1H} NMR, b. 25.0 to 88.0 wt.-% of a secondary component (B) being a first virgin high-density polyethylene (HDPE1) optionally blended with carbon black, the secondary component (B) having a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.2 to 0.6 g/10 min; a density of from 955 to 970 kg/m.sup.3; a shear thinning index SHI.sub.2.7/210 of 15 to 30; a polydispersity index from 1.6 to 2.2 s.sup.−1 as obtained from rheological measurement; optionally a carbon black content of 1.5 to 3.0 wt.-% with respect to the secondary component (B); and a limonene content below 0.10 ppm, c. 2.0 to 20.0 wt.-% of a second virgin high-density polyethylene (C) having a melt flow rate (ISO 1133, 5.0 kg, 190° C.) of from 0.10 to 0.5 g/10 min; a density from 945 to 965 kg/m.sup.3; a polydispersity index from 2.2 to 4.0 s.sup.−1 as obtained from rheological measurement; and a limonene content below 0.10 ppm.

2. A mixed-plastic-polyethylene composition according to claim 1, having a density of from 959 to 966 kg/m.sup.3; the mixed-plastic-polyethylene composition.

3. The mixed-plastic-polyethylene composition of claim 1 comprising carbon black in an amount of 1.0 to 3.0 wt.-% with respect to the total of the mixed-plastic-polyethylene composition.

4. The mixed-plastic-polyethylene composition according to claim 1 comprising one or more in any combination of: a total amount of units having 3 carbon atoms as isolated peaks in the NMR spectrum (isolated C3 units) of from 0.00 wt.-% to 0.12 wt.-%; a total amount of units having 6 carbon atoms (C6 units) of from 0.00 wt.-% to 0.50 wt.-%; a total amount of units having 7 carbon atoms (C7 units) of from 0.00 wt.-% to 0.10 wt.-%; wherein the total amounts of isolated C3 units, C4 units, C6 units, C7 units are based on the total weight amount of monomer units in the composition and are measured or calculated according to quantitative .sup.13C{.sup.1H} NMR measurement.

5. (canceled)

6. The mixed-plastic-polyethylene composition according to claim 1, wherein the mixed-plastic-polyethylene primary recycling blend (A) has an ESCR (Bell test failure time) of less than 1000 hours; and optionally includes TiO.sub.2 in an amount of up to 3.0 wt.-% with respect to mixed-plastic-polyethylene primary recycling blend (A).

7. The mixed-plastic-polyethylene composition according to claim 1, wherein the secondary component (B) has an ESCR (Bell test failure time) of at least 2500 hours.

8. The mixed-plastic-polyethylene composition according to claim 1, wherein the second virgin high-density polyethylene (C) has: i. a melt flow rate (ISO 1133, 21.6 kg, 190° C.) of from 5.0 to 12.0 g/10 min; and/or ii. a comonomer content in the range from 1.5 to 3.0 wt.-%, wherein the comonomer is selected from C(3-8) alpha-olefins.

9. The mixed-plastic-polyethylene composition according to claim 1, wherein the composition has an ESCR (Bell test failure time) of at least 1000 hours.

10. The mixed-plastic-polyethylene composition according to claim 1, wherein the impact strength at 23° C. (according to ISO 179-1 eA) is from 3.0 to 15.0 kJ/m.sup.2 and/or wherein the impact strength at 0° C. (according to ISO 179-1 eA) is from 2.5 to 10.0 kJ/m.sup.2.

11. The mixed-plastic-polyethylene composition according to any one of the preceding claims, wherein the strain hardening modulus (SH modulus) is from 15.0 to 25.0 MPa.

12. The mixed-plastic-polyethylene composition according to claim 1, having i. a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.2 to 0.6 g/10 min, and/or ii. a melt flow rate (ISO 1133, 5 kg, 190° C.) of from 1.2 to 2.2 g/10 min, and/or iii. a melt flow rate (ISO 1133, 21 kg, 190° C.) of from 30.0 to 50.0 g/10 min.

13. The mixed-plastic-polyethylene composition according to claim 1, wherein the SHI.sub.2.7/210 is between 35.0 and 50.0.

14. The mixed-plastic-polyethylene composition according to claim 1, wherein the composition is characterized in that a compression moulded plaque made from the composition having 1 mm thickness has a tear resistance of at least 22.0 N/mm and optionally up to 30.0 N/mm.

15. An article comprising the mixed-plastic-polyethylene composition according to claim 1, wherein the article is a cable jacket.

16. A process for preparing the mixed-plastic-polyethylene composition according to claim 1, comprising: a. providing a mixed-plastic-polyethylene primary recycling blend (A) in an amount of 10.0 to 70.0 wt.-% based on the overall weight of the composition, wherein 100.0 wt.-% of the mixed-plastic-polyethylene primary blend (A) originates from post-consumer waste having a limonene content of from 0.10 to 500 ppm and wherein the mixed-plastic-polyethylene primary blend has a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.4 to 1.3 g/10 min: a density of from 945 to 990 kg/m.sup.3; and a content of units derived from ethylene of 70.0 to 95.0 wt.-% as determined by quantitative .sup.13C{.sup.1H}-NMR; b. providing a secondary component (B) being a first virgin high-density polyethylene (HDPE1) optionally blended with carbon black, in an amount of 25.0 to 88.0 wt.-% based on the overall weight of the composition, the secondary component (B) having a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from from 0.2 to 0.6 g/10 min; a density of from 955 to 970 kg/m.sup.3, a shear thinning index SHI.sub.2.7/210 of 15 to 30 a polydispersity index from 1.6 to 2.2 s.sup.−1 as obtained from rheological measurement, optionally a carbon black content of 1.5 to 3.0 wt.-% with respect to the secondary component (B); and a limonene content below 0.10 ppm. c. providing a second virgin high-density polyethylene (C) in an amount of 2.0 to 20.0 wt.-%, based on the overall weight of the composition, the second virgin high-density polyethylene having a melt flow rate (ISO 1133, 5.0 kg, 190° C.) of from 0.10 to 0.5 g/10 min; a density from 945 to 965 kg/m.sup.3, polydispersity index from 2.2 to 4.0 s.sup.−1 as obtained from rheological measurement; and a limonene content below 0.10 ppm d. melting and mixing a blend of mixed-plastic-polyethylene primary blend (A), the secondary component (B) and the second virgin high-density polyethylene (C) in an extruder, optionally a twin screw extruder, and e. optionally pelletizing the obtained mixed-plastic-polyethylene composition.

Description

DETAILED DESCRIPTION

[0088] Natural Mixed-Plastic-Polyethylene Primary Recycling Blend (A)

[0089] The mixed-plastic-polyethylene composition according to the present invention comprises a mixed-plastic-polyethylene primary recycling blend (A). It is the essence of the present invention that this primary recycling blend is obtained from a post-consumer waste stream.

[0090] According to the present invention the mixed-plastic-polyethylene primary recycling blend (A) is generally a blend, wherein at least 90.0 wt.-%, preferably at least 95.0 wt.-%, more preferably 100.0 wt.-% of the mixed-plastic-polyethylene primary blend originates from post-consumer waste, such as from conventional collecting systems (curb-side collection), such as those implemented in the European Union.

[0091] Said post-consumer waste can be identified by its limonene content. It is preferred that the post-consumer waste has a limonene content of from 0.10 to 500 ppm.

[0092] The mixed-plastic-polyethylene primary recycling blend (A) preferably comprises a total amount of ethylene units (C2 units) of from 70.0 wt.-% to 95.0 wt.-%, more preferably of from 71.5 wt.-% to 92.0 wt.-%, still more preferably of from 73.0 wt.-% to 90.0 wt.-% and most preferably of from 74.0 wt.-% to 88.0 wt.-%.

[0093] The total amounts of C2 units are based on the total weight amount of monomer units in the mixed-plastic-polyethylene primary recycling blend (A) and are measured according to quantitative .sup.13C{1 H} NMR measurement.

[0094] The mixed-plastic-polyethylene primary recycling blend (A) preferably further comprises a total amount of continuous units having 3 carbon atoms corresponding to polypropylene (continuous C3 units) of from 4.0 to 30.0 wt.-%, more preferably from 7.0 wt.-% to 28.0 wt.-%, still more preferably from 9.0 wt.-% to 26.5 wt.-% and most preferably from 11.0 wt.-% to 25.5 wt.-%.

[0095] In addition to C2 units and continuous C3 units the mixed-plastic-polyethylene primary recycling blend (A) can further comprise units having 3, 4, 6 or 7 or more carbon atoms so that the mixed-plastic-polyethylene primary recycling blend (A) overall can comprise ethylene units and a mix of units having 3, 4, 6 and 7 or more carbon atoms.

[0096] The mixed-plastic-polyethylene primary recycling blend (A) preferably comprises one or more in any combination, preferably all of: [0097] a total amount of units having 3 carbon atoms as isolated C3 units (isolated C3 units) of from 0.01 wt.-% to 0.50 wt.-%, more preferably from 0.05 wt.-% to 0.45 wt.-%, still more preferably from 0.10 wt.-% to 0.40 wt.-% and most preferably from 0.15 wt.-% to 0.35 wt.-%; [0098] a total amount of units having 4 carbon atoms (C4 units) of from 0.01 to 0.60 wt.-%, more preferably from 0.05 wt.-% to 0.50 wt.-%, still more preferably from 0.10 wt.-% to 0.45 wt.-% and most preferably from 0.20 wt.-% to 0.40 wt.-%; [0099] a total amount of units having 6 carbon atoms (C6 units) of from 0.01 to 1.00 wt.-%, more preferably from 0.05 wt.-% to 0.80 wt.-%, still more preferably from 0.10 wt.-% to 0.60 wt.-% and most preferably from 0.15 wt.-% to 0.50 wt.-%; and [0100] a total amount of units having 7 carbon atoms (C7 units) of from 0.00 wt.-% to 0.50 wt.-%, of from 0.00 wt.-% to 0.20 wt.-%, still more preferably of from 0.00 to 0.10 wt.-% yet more preferably of from 0.00 wt.-% to 0.05 wt.-%, most preferably there are is no measureable content of units having 7 carbon atoms (C7 units).

[0101] The total amounts of C2 units, continuous C3 units, isolated C3 units, C4 units, C6 units and C7 units thereby are based on the total weight amount of monomer units in the mixed-plastic-polyethylene primary recycling blend (A) and are measured or calculated according to quantitative .sup.13C{1 H} NMR measurement.

[0102] Preferably, the total amount of units, which can be attributed to comonomers (i.e. isolated C3 units, C4 units, C6 units and C7 units), in the mixed-plastic-polyethylene primary recycling blend (A) is from 0.10 wt.-% to 2.00 wt.-%, more preferably from 0.20 wt.-% to 1.70 wt.-%, still more preferably from 0.25 wt.-% to 1.40 wt.-% and most preferably from 0.30 wt.-% to 1.20 wt.-%, and is measured according to quantitative .sup.13C{.sup.1H} NMR measurement.

[0103] It is preferred that the mixed-plastic-polyethylene primary recycling blend (A) has [0104] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 1.2 g/10 min, more preferably from 0.5 to 1.0 g/10 min; and/or [0105] a density of from 945 to 990 kg/m.sup.3, more preferably from 948 to 987 kg/m.sup.3, most preferably from 950 to 985 kg/m.sup.3.

[0106] The mixed-plastic-polyethylene primary recycling blend (A) may also include: [0107] a) 0 to 10.0 wt.-% units derived from olefin(s) comprising functional groups, [0108] b) 0 to 3.0 wt.-% stabilizers, [0109] c) 0 to 3.0 wt.-% talc, [0110] d) 0 to 3.0 wt.-% chalk, [0111] e) 0 to 3.0 wt.-% TiO.sub.2, and [0112] f) 0 to 6.0 wt.-% further components
all percentages with respect to the mixed-plastic-polyethylene primary recycling blend (A).

[0113] The mixed-plastic-polyethylene primary recycling blend (A) preferably has one or more, more preferably all, of the following properties in any combination: [0114] a melt flow rate (ISO 1133, 5.0 kg, 190° C.) of from 2.0 to 6.0 g/10 min, more preferably from 3.0 to 5.0 g/10 min; [0115] a melt flow rate (ISO 1133, 21.6 kg, 190° C.) of from 50.0 to 120.0 g/10 min, more preferably from 70.0 to 100.0 g/10 min; [0116] a polydispersity index PI of from 1.2 to 2.5 s.sup.−1, more preferably from 1.6 to 2.2 s.sup.−1, yet more preferably from 1.7 to 2.1 s.sup.−1; [0117] a shear thinning index SHI.sub.2.7/210 of from 30 to 60, more preferably 35 to 50, yet more preferably from 38 to 47; [0118] a complex viscosity at the frequency of 300 rad/s, eta.sub.300, of from 450 to 700 Pa.Math.s, more preferably from 500 to 650 Pa.Math.s; [0119] a complex viscosity at the frequency of 0.05 rad/s, eta.sub.0.05, of from 20000 to 40000 Pa.Math.s, more preferably from 25000 to 35000 Pa.Math.s; [0120] a xylene hot insoluble content, XHU, of from 0.01 to 1.0 wt.-%, more preferably from 0.1 to 0.5 wt.-%, and/or [0121] a limonene content of from 0.10 to 500 ppm.

[0122] Generally, 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. Usually ESCR (Bell test failure time) of recycled materials is extremely low, and frequently not measurable at all with the standard test (complete failure).

[0123] The mixed-plastic-polyethylene primary recycling blend (A) is preferably present in the composition of the present invention in an amount of from 10.0 to 70.0 wt.-%, more preferably 10.0 to 60.0 wt.-%, still more preferably from 15.0 to 50.0 wt.-%, and most preferably from 20.0 to 45.0 wt.-%, based on the overall weight of the composition.

[0124] Secondary Component (B)

[0125] The mixed-plastic-polyethylene composition of the invention comprises a secondary component (B) being a virgin high-density polyethylene (HDPE1) optionally blended with carbon black (CB).

[0126] The secondary component (B) preferably has: [0127] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 1.2 g/10 min, preferably from 0.2 to 0.6 g/10 min; and/or [0128] a density of from 940 to 970 kg/m.sup.3, more preferably 955 to 970 kg/m.sup.3, et more preferably from 959 to 967 kg/m.sup.3; and/or [0129] a polydispersity index from 1.6 to 2.2 s.sup.−1, more preferably from 1.8 to 2.1 s.sup.−1, [0130] a shear thinning index SHI.sub.2.7/210 of 15 to 30, more preferably 20 to 27, [0131] optionally a carbon black content of 1.5 to 3.0 wt.-%, with respect to the secondary component (B), more preferably of 1.8 to 2.8 wt.-%, and [0132] a limonene content below 0.10 ppm.

[0133] The secondary component (B) includes as 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.

[0134] Apart from the polymeric component the secondary component (B) can further comprise additives in an amount of 10 wt.-% or below, more preferably 9 wt.-% or below, more preferably 7 wt.-% or below of the secondary component (B). Suitable additives are usual additives for utilization with polyolefins, such as stabilizers (e.g. antioxidant agents), metal scavengers and/or UV-stabilizers, antistatic agents and utilization agents (such as processing aid agents).

[0135] The secondary component (B) preferably has one or more, more preferably all of the following properties in any combination: [0136] a melt flow rate (ISO 1133, 5.0 kg, 190° C.) of from 1.0 to 5.0 g/10 min, more preferably from 1.3 to 3.0 g/10 min; [0137] a melt flow rate (ISO 1133, 21.6 kg, 190° C.) of from 20.0 to 50.0 g/10 min, more preferably from 25.0 to 40.0 g/10 min; [0138] a complex viscosity at the frequency of 300 rad/s, eta.sub.300, of from 500 to 900 Pa.Math.s, more preferably from 600 to 850 Pa.Math.s; [0139] a complex viscosity at the frequency of 0.05 rad/s, eta.sub.0.05, of from 15000 to 30000 Pa.Math.s, more preferably from 17500 to 27500 Pa.Math.s; [0140] a Shore D hardness, measured after 15 s according to ISO 868, Shore D 15 s, of from 50.0 to 70.0, more preferably of from 55.0 to 65.0, [0141] a Shore D hardness, measured after 1 s according to ISO 868, Shore D 1 s, of from 55.0 to 75.0, more preferably of from 58.0 to 70.0, [0142] a Shore D hardness, measured after 3 s according to ISO 868, Shore D 3 s, of from 55.0 to 75.0, more preferably of from 58.0 to 70.0, [0143] a strain hardening modulus, SH modulus, of from 20.0 to 35.0 MPa, more preferably from 22.5 to 32.5 MPa, [0144] a Charpy notched impact strength at 23° C., Charpy NIS 23° C., of from 8.0 to 20.0 kJ/m.sup.2, more preferably from 10.0 to 17.5 kJ/m.sup.2, [0145] a Charpy notched impact strength at 0° C., Charpy NIS 0° C., of from 4.0 to 15.0 kJ/m.sup.2, more preferably from 6.0 to 12.5 kJ/m.sup.2, [0146] a tensile stress at break of from 25 to 50 MPa, more preferably from 28 to 40 MPa, [0147] a tensile strain at break of from 700 to 1000%, more preferably from 800 to 950%, [0148] an environmental stress crack resistance, ESCR, of at least 2500 hours, more preferably at least 3000 hours.

[0149] Generally, 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.

[0150] The secondary component (B) is preferably present in the composition of the present invention in an amount of from 25.0 to 88.0 wt.-%, more preferably 35.0 to 85.0 wt.-%, still more preferably from 45.0 to 80.0 wt.-%, and most preferably from 50.0 to 75.0 wt.-%, based on the overall weight of the composition.

[0151] The secondary component (B) preferably contains carbon black in and amount of 1.5 to 3.0 wt.-%, with respect to the secondary component (B), more preferably of 1.8 to 2.8 wt.-% and most preferably 2.0 to 2.8 wt.-%.

[0152] Second Virgin High-Density Polyethylene (C)

[0153] The mixed-plastic-polyethylene composition of the invention comprises a second virgin high-density polyethylene (C).

[0154] The second virgin high-density polyethylene (C) preferably has one or more, more preferably all of the following properties in any combination [0155] a melt flow rate (ISO 1133, 5.0 kg, 190° C.) of from 0.05 to 1.0 g/10 min, preferably from 0.05 to 0.7 g/10 min, more preferably from 0.10 to 0.5 g/10 min; [0156] a density from 945 to 965 kg/m.sup.3; [0157] a polydispersity index from 2.2 to 4.0 s.sup.−1 as obtained from rheological measurement; and/or [0158] a limonene content below 0.10 ppm.

[0159] It is further preferred that the second virgin high-density polyethylene (C) has one or both of the following properties [0160] a melt flow rate (ISO 1133, 21.6 kg, 190° C.) of from 3.0 to 15.0 g/10 min, preferably from 5.0 to 12.0 g/10 min; and/or [0161] a comonomer content in the range from 1.0 to 5.0 wt.-%, more preferably in the range from 1.5 to 3.0 wt.-%,

[0162] The second virgin high-density polyethylene (C) preferably includes as polymeric component a copolymer of ethylene and one or more comonomer units selected from alpha-olefins having from 3 to 8 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, most preferably a copolymer of ethylene and 1-hexene.

[0163] The second virgin high-density polyethylene (C) is preferably present in the composition of the present invention in an amount of from 2.0 to 20.0 wt.-%, more preferably 3.0 to 18.0 wt.-%, still more preferably 4.0 to 16.0 wt.-%, and most preferably from 5.0 to 15.0 wt.-%, based on the overall weight of the composition.

[0164] Mixed-Plastic-Polyethylene Composition

[0165] The present invention seeks to provide a mixed-plastic-polyethylene composition comprising a mixed-plastic-polyethylene primary recycling blend (A) with improved ESCR, impact strength and SH modulus compared to the mixed-plastic-polyethylene primary recycling blend (A), to levels which are suitable for jacketing applications.

[0166] The mixed-plastic-polyethylene composition as described herein is especially suitable for wire and cable applications, such as jacketing applications.

[0167] In a first aspect the present invention relates to a mixed-plastic-polyethylene composition comprising [0168] a total amount of ethylene units (C2 units) of from 90.0 to 95 wt.-%, preferably 90.0 to 93.3 wt.-%, and [0169] a total amount of continuous units having 3 carbon atoms corresponding to polypropylene (continuous C3 units) of from 4.0 to 8.0 wt.-%, preferably 5.5 to 6.5 wt.-%, [0170] a total amount of units having 4 carbon atoms (C4 units) of from 1.00 to 2.00 wt.-%, preferably 1.20 wt.-% to 1.40 wt.-%;
with the total amounts of C2 units, continuous C3 units and units having 4 carbon atoms being based on the total weight amount of monomer units in the composition and measured according to quantitative .sup.13C{.sup.1H} NMR measurement,
and wherein the composition has [0171] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 0.9 g/10 min, and [0172] a density of from 956 kg/m.sup.3 to 970 kg/m.sup.3.

[0173] In a preferable aspect the present invention relates to a mixed-plastic-polyethylene composition comprising [0174] a total amount of ethylene units (C2 units) of from 90.0 to 93.0 wt.-%, and [0175] a total amount of continuous units having 3 carbon atoms corresponding to polypropylene (continuous C3 units) of from 4.0 to 8.0 wt.-%, and [0176] a total amount of units having 4 carbon atoms (C4 units) of from 1.20 wt.-% to 1.40 wt.-%;
with the total amounts of C2 units, continuous C3 units and units having 4 carbon atoms being based on the total weight amount of monomer units in the composition and measured according to quantitative .sup.13C{.sup.1H} NMR measurement,
and wherein the composition has [0177] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 0.9 g/10 min, and [0178] a density of from 958 kg/m.sup.3 to 968 kg/m.sup.3, preferably from 959 to 966 kg/m.sup.3.

[0179] In said aspect the mixed-plastic-polyethylene composition preferably comprises carbon black in an amount of 1.0 to 3.0 wt.-% with respect to the total of the mixed-plastic-polyethylene composition, more preferably of 1.1 to 2.8 wt.-%, most preferably 1.2 to 2.6 wt.-%.

[0180] In said aspect the mixed-plastic-polyethylene composition is preferably obtainable by blending and extruding [0181] a) 10.0 to 70.0 wt.-% of a mixed-plastic-polyethylene primary recycling blend (A) wherein 90.0 wt.-%, preferably 95.0 wt.-%, more preferably 100.0 wt.-% of the mixed-plastic-polyethylene primary blend (A) originates from post-consumer waste having a limonene content of from 0.10 to 500 ppm; and wherein the mixed-plastic-polyethylene primary blend (A) has [0182] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 1.5 g/10 min, preferably from 0.4 to 1.3 g/10 min, [0183] a density of from 945 to 990 kg/m.sup.3, [0184] optionally a shear thinning index SHI.sub.2.7/210 of 30 to 60, preferably 35 to 50 [0185] optionally a polydispersity index from 1.2 to 2.5 s.sup.−1, more preferably 1.6 to 2.2 s.sup.−1 as obtained from rheological measurement, [0186] and a content of units derived from ethylene of 70 to 95 wt.-% as determined by quantitative .sup.13C{.sup.1H}-NMR, [0187] b) 25.0 to 88.0 wt.-% of a secondary component (B) being a virgin high-density polyethylene (HDPE1) optionally blended with carbon black, the secondary component (B) having [0188] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 1.2 g/10 min, preferably from 0.2 to 0.6 g/10 min; [0189] a density of from 940 to 970 kg/m.sup.3, preferably from 955 to 970 kg/m.sup.3, [0190] a shear thinning index SHI.sub.2.7/210 of 15 to 30 [0191] a polydispersity index from 1.6 to 2.2 s.sup.−1 as obtained from rheological measurement, [0192] optionally a carbon black content of 1.5 to 3.0 wt.-% with respect to the secondary component (B), and [0193] preferably a limonene content below 2 ppm, [0194] c) 2.0 to 20.0 wt.-% of a second virgin high-density polyethylene (C) having [0195] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.05 to 0.7 g/10 min, more preferably from 0.05 to 1.0 g/10 min, preferably from 0.10 to 0.5 g/10 min; [0196] a density from 945 to 965 kg/m.sup.3, [0197] a polydispersity index from 2.2 to 4.0 s.sup.−1 as obtained from rheological measurement; and [0198] Preferably a limonene content below 0.10 ppm.

[0199] In a second aspect the present invention relates to a mixed-plastic-polyethylene composition obtainable by blending and extruding [0200] a) 10.0 to 70.0 wt.-% of a mixed-plastic-polyethylene primary recycling blend (A) wherein 90.0 wt.-%, preferably 95.0 wt.-%, more preferably 100.0 wt.-% of the mixed-plastic-polyethylene primary blend (A) originates from post-consumer waste having a limonene content of from 0.10 to 500 ppm; and wherein the mixed-plastic-polyethylene primary blend (A) has [0201] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 1.5 g/10 min, preferably from 0.4 to 1.3 g/10 min, [0202] a density of from 945 to 990 kg/m.sup.3, [0203] optionally a shear thinning index SHI.sub.2.7/210 of 30 to 60, preferably 35 to 50 [0204] optionally a polydispersity index from 1.2 to 2.5 s.sup.−1, preferably 1.6 to 2.2 s.sup.−1 as obtained from rheological measurement, [0205] and a content of units derived from ethylene of 70 to 95 wt.-% as determined by quantitative .sup.13C{.sup.1H}-NMR, [0206] b) 25.0 to 88.0 wt.-% of a secondary component (B) being a virgin high-density polyethylene (HDPE1) optionally blended with carbon black, the secondary component (B) having [0207] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 1.2 g/10 min, preferably from 0.2 to 0.6 g/10 min; [0208] a density of from 940 to 970 kg/m.sup.3, preferably 955 to 970 kg/m.sup.3, [0209] a shear thinning index SHI.sub.2.7/210 of 15 to 30 [0210] a polydispersity index from 1.6 to 2.2 s.sup.−1 as obtained from rheological measurement, [0211] optionally a carbon black content of 1.5 to 3.0 wt.-% with respect to the secondary component (B), and [0212] preferably a limonene content below 2 ppm, [0213] c) 2.0 to 20.0 wt.-% of a second virgin high-density polyethylene (C) having [0214] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.05 to 1.0 g/10 min, preferably from 0.05 to 0.7 g/10 min, more preferably from 0.10 to 0.5 g/10 min; [0215] a density from 945 to 965 kg/m.sup.3, [0216] a polydispersity index from 2.2 to 4.0 s.sup.−1 as obtained from rheological measurement; and [0217] Preferably a limonene content below 0.10 ppm.

[0218] The mixed-plastic-polyethylene composition preferably comprises [0219] a total amount of ethylene units (C2 units) of 91.0 to 94.0 wt.-%, more preferably from 92.0 to 93.3 wt.-%, [0220] a total amount of continuous units having 3 carbon atoms corresponding to polypropylene (continuous C3 units) of from 4.0 to 8.0 wt.-%, preferably from 5.5 wt.-% to 6.5 wt.-%, and [0221] a total amount of units having 4 carbon atoms (C4 units) of 1.20 wt.-% to 1.40 wt.-%.

[0222] In a further preferred embodiment, the mixed-plastic-polyethylene composition comprises [0223] a total amount of ethylene units (C2 units) of from 90.0 to 93.3 wt.-%, [0224] a total amount of continuous units having 3 carbon atoms corresponding to polypropylene (continuous C3 units) of from 5.5 to 6.5 wt.-%, and [0225] a total amount of units having 4 carbon atoms (C4 units) of from 1.20 wt.-% to 1.40 wt.-%.

[0226] Further, the mixed-plastic-polyethylene composition preferably comprises one or more in any combination of, more preferably all of: [0227] a total amount of units having 3 carbon atoms as isolated peaks in the NMR spectrum (isolated C3 units) of from 0.00 wt.-% to 0.20 wt.-%, more preferably from 0.00 wt.-% to 0.15 wt.-%, still more preferably from 0.00 wt.-% to 0.12 wt.-%; [0228] a total amount of units having 6 carbon atoms (C6 units) of from 0.00 wt.-% to 1.00 wt.-%, more preferably from 0.00 wt.-% to 0.75 wt.-%, still more preferably from 0.00 wt.-% to 0.50 wt.-%; [0229] a total amount of units having 7 carbon atoms (C7 units) of from 0.00 wt.-% to 0.20 wt.-%, more preferably from 0.00 wt.-% to 0.15 wt.-%, still more preferably from 0.00 wt.-% to 0.10 wt.-%;
wherein the total amounts of isolated C3 units, C4 units, C6 units, C7 units are based on the total weight amount of monomer units in the composition and are measured or calculated according to quantitative .sup.13C{.sup.1H} NMR measurement.

[0230] Preferably, the total amounts of units, which can be attributed to comonomers other than C4 (i.e. isolated C3 units, C6 units and C7 units), in the mixed-plastic-polyethylene composition is from 0.00 wt.-% to 1.00 wt.-%, more preferably from 0.00 wt.-% to 0.60 wt.-%, still more preferably from 0.00 wt.-% to 0.40 wt.-%, and is measured according to quantitative .sup.13C{.sup.1H}NMR measurement.

[0231] The mixed-plastic polyethylene composition according to the present invention has a [0232] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 0.9 g/10 min, preferably from 0.2 to 0.6 g/10 min; [0233] a density of from 956 to 970 kg/m.sup.3, preferably 958 to 968 kg/m.sup.3, more preferably from 959 to 966 kg/m.sup.3;

[0234] The composition can have further components apart from the mixed-plastic-polyethylene primary recycling blend (A), the secondary component (B) and the second virgin high-density polyethylene (C) such as further polymeric components or additives in amounts of not more than 15 wt.-%, based on the total weight of the composition.

[0235] Suitable additives are usual additives for utilization with polyolefins, such as stabilizers, (e.g. antioxidant agents), metal scavengers and/or UV stabilizers, antistatic agents, and utilization agents. The additives can be present in the composition in an amount of 10 wt.-% or below, more preferably 9 wt.-% or below, more preferably 7 wt.-% or below.

[0236] It is, however, preferred that the composition consists of the mixed-plastic-polyethylene primary recycling blend (A), the secondary component (B) and the second virgin high-density polyethylene (C).

[0237] The mixed-plastic-polyethylene composition according to the present invention is preferably obtainable by blending and extruding [0238] a) 10.0 to 70.0 wt.-% of a mixed-plastic-polyethylene primary recycling blend (A) [0239] b) 25.0 to 88.0 wt.-% of a secondary component (B) being a virgin high-density polyethylene (HDPE1) optionally blended with carbon black, and [0240] c) 2.0 to 20.0 wt.-% of a second virgin high-density polyethylene (C).

[0241] In a preferable embodiment, the composition is obtainable by blending and extruding [0242] a) 10.0 to 60.0 wt.-% of a mixed-plastic-polyethylene primary recycling blend (A) [0243] b) 30.0 to 85.0 wt.-% of a secondary component (B) being a virgin high-density polyethylene (HDPE1) optionally blended with carbon black, and [0244] c) 3.0 to 18.0 wt.-% of a second virgin high-density polyethylene (C).

[0245] In a further preferable embodiment, the composition is obtainable by blending and extruding [0246] a) 15.0 to 50.0 wt.-% of a mixed-plastic-polyethylene primary recycling blend (A) [0247] b) 40.0 to 80.0 wt.-% of a secondary component (B) being a virgin high-density polyethylene (HDPE1) optionally blended with carbon black, and [0248] c) 4.0 to 16.0 wt.-% of a second virgin high-density polyethylene (C).

[0249] In a yet further preferable embodiment, the composition is obtainable by blending and extruding [0250] a) 20.0 to 45.0 wt.-% of a mixed-plastic-polyethylene primary recycling blend (A) [0251] b) 50.0 to 75.0 wt.-% of a secondary component (B) being a virgin high-density polyethylene (HDPE1) optionally blended with carbon black, and [0252] c) 5.0 to 15.0 wt.-% of a second virgin high-density polyethylene (C).

[0253] The mixed-plastic-polyethylene primary recycling blend (A), the secondary component (B) and the second virgin high-density polyethylene (C) are generally defined as described above or below.

[0254] The mixed plastic polyethylene composition preferably has an impact strength at 23° C. (ISO 179-1 eA) of from 3.0 to 15.0 kJ/m.sup.2, preferably from 5.0 to 10.0 kJ/m.sup.2.

[0255] Further, the mixed plastic polyethylene composition preferably has an impact strength at 0° C. (according to ISO 179-1 eA) of from 2.5 to 10.0 kJ/m.sup.2, more preferably from 4.1 to 8.0 kJ/m.sup.2.

[0256] The mixed-plastic-polyethylene composition preferably has a strain hardening modulus (SH modulus) of from 15.0 to 25.0 MPa, more preferably from 17.0 to 24.5 MPa and most preferably from 19.0 to 24.0 MPa.

[0257] It is preferred that that the mixed-plastic-polyethylene composition preferably has [0258] a Shore D hardness, measured according to ISO 868 with a measuring time of 1 s, Shore D 1 s, of from 55.0 to 70.0, more preferably from 57.0 to 68.0 and most preferably from 60.0 to 65.0, and/or [0259] a Shore D hardness, measured according to ISO 868 with a measuring time of 3 s, Shore D 3 s, of from 55.0 to 70.0, more preferably from 57.0 to 68.0 and most preferably from 60.0 to 65.0, and/or [0260] a Shore D hardness, measured according to ISO 868 with a measuring time of 15 s, Shore D 15 s, of from 55.0 to 70.0, more preferably from 57.0 to 68.0 and most preferably from 60.0 to 65.0.

[0261] The mixed-plastic-polyethylene composition preferably has one or more, preferably all of the following rheological properties, in any combination: [0262] a shear thinning index SHI.sub.2.7/210 of from 35.0 to 50.0, more preferably from 37 to 45, and/or [0263] a complex viscosity at 0.05 rad/s, eta.sub.0.05, of from 28000 to 42000 Pa.Math.s, more preferably from 31000 to 39000 Pa.Math.s, and/or [0264] a complex viscosity at 300 rad/s, eta.sub.300, of from 650 to 850 Pa.Math.s, more preferably from 700 to 800 Pa.Math.s, and/or [0265] a polydispersity index PI of from 2.2 to 3.0 s.sup.−1, more preferably from 2.4 to 2.8 s.sup.−1.

[0266] Further, the mixed-plastic-polyethylene composition preferably has one or more, preferably all of the following melt flow rate properties, in any combination: [0267] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.2 to 0.6 g/10 min, and/or [0268] a melt flow rate (ISO 1133, 5 kg, 190° C.) of from 1.2 to 2.2 g/10 min, and/or [0269] a melt flow rate (ISO 1133, 21 kg, 190° C.) of from 30.0 to 50.0 g/10 min.

[0270] Still further, the mixed-plastic-polyethylene composition preferably has one or more, preferably all of the following tensile properties, in any combination: [0271] a tensile strain at break, measured according to ISO 527-2 on compression moulded test specimens of type 5A, of from 500% to 780%, more preferably from 550% to 750%; and/or [0272] a tensile stress at break, measured according to ISO 527-2 on compression moulded test specimens of type 5A, of from 10 MPa to 30 MPa, more preferably from 15 MPa to 25 MPa.

[0273] Further, the mixed-plastic-polyethylene composition preferably has a tear resistance of from 15.0 to 30.0 N/mm, more preferably of from 17.5 to 27.5 N/mm and most preferably of from 20.0 to 25.0 N/mm. The tear resistance of the mixed-plastic-polyethylene composition is measured on a compression moulded plaque made from the composition having 1 mm thickness.

[0274] It is further preferred that the mixed-plastic-polyethylene composition has a pressure deformation of not more than 15%, more preferably not more than 10%. The lower limit is usually at least 3%, preferably at least 4%.

[0275] Still further, the mixed-plastic-polyethylene composition has a water content of preferably not more than 500 ppm more preferably not more than 300 ppm. The lower limit is usually at least 10 ppm.

[0276] The mixed-plastic-polyethylene composition preferably also has an ESCR (Bell test failure time of at least 1000 hours, preferably at least 1500 hours, most preferably at least 2000 hours.

[0277] Article

[0278] The present application is further directed to an article comprising the mixed-plastic-polyethylene composition as described above.

[0279] In a preferred embodiment, the article is used in jacketing applications i.e. for a cable jacket. Preferably, the article is a cable comprising at least one layer which comprises the mixed-plastic-polyethylene composition as described above.

[0280] 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 2.0%, more preferably not more than 1.5%. The lower limit is usually at least 0.3%, preferably at least 0.5%.

[0281] All preferred aspects and embodiments as described above shall also hold for the article.

[0282] Process

[0283] The present invention also relates to a process for preparing the mixed-plastic-polyethylene composition as defined above or below. The process according to the present invention results in an improvement in the mechanical properties of the mixed-plastic-polyethylene primary recycling blend (A).

[0284] The process according to the present invention comprises the steps of: [0285] a. providing a mixed-plastic-polyethylene primary recycling blend (A) in an amount of 10.0 to 70.0 wt.-% based on the overall weight of the composition, [0286] wherein 90.0 wt.-%, preferably 95.0 wt.-%, more preferably 100.0 wt.-% of the mixed-plastic-polyethylene primary blend (A) originates from post-consumer waste having a limonene content of from 0.10 to 500 ppm and wherein the mixed-plastic-polyethylene primary blend has [0287] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 1.5 g/10 min, preferably from 0.4 to 1.3 g/10 min, [0288] a density of from 945 to 990 kg/m.sup.3, [0289] optionally a shear thinning index SHI.sub.2.7/210 of 30 to 60, preferably 35 to 50 [0290] optionally a polydispersity index from 1.2 to 2.5 s.sup.−1, more preferably 1.6 to 2.2 s.sup.−1 as obtained from rheological measurement, [0291] and a content of units derived from ethylene of 70.0 to 95.0 wt.-% as determined by quantitative .sup.13C{1H}-NMR, [0292] b. providing a secondary component (B) being a virgin high-density polyethylene (HDPE1) optionally blended with carbon black, in an amount of 25.0 to 88.0 wt.-% based on the overall weight of the composition, the secondary component (B) having [0293] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.1 to 1.2 g/10 min, preferably from 0.2 to 0.6 g/10 min, [0294] a density of from 940 to 970 kg/m.sup.3, preferably 955 to 970 kg/m.sup.3, [0295] a shear thinning index SHI.sub.2.7/210 of 15 to 30, [0296] a polydispersity index from 1.6 to 2.2 s.sup.−1 as obtained from rheological measurement, [0297] optionally a carbon black content of 1.5 to 3.0 wt.-% with respect to the secondary component (B); and [0298] preferably, a limonene content below 0.10 ppm. [0299] c. Providing a second virgin high-density polyethylene (C) in an amount of 2.0 to 20.0 wt.-%, based on the overall weight of the composition, the second virgin high-density polyethylene having [0300] a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of from 0.05 to 1.0 g/10 min, preferably from 0.05 to 0.7 g/10 min, more preferably from 0.10 to 0.5 g/10 min; [0301] a density from 945 to 965 kg/m.sup.3, [0302] a polydispersity index from 2.2 to 4.0 s.sup.−1 as obtained from rheological measurement; and [0303] Preferably a limonene content below 0.10 ppm [0304] d. melting and mixing the blend of mixed-plastic-polyethylene primary blend (A), the secondary component (B) and the second virgin high-density polyethylene (C) in an extruder, optionally a twin screw extruder, and [0305] e. optionally pelletizing the obtained mixed-plastic-polyethylene composition.

[0306] All preferred aspects, definitions and embodiments as described above shall also hold for the process.

[0307] Experimental Part

1. Test Methods

[0308] a) Melt Flow Rate

[0309] Melt flow rates were measured with a load of 2.16 kg (MFR.sub.2), 5.0 kg (MFR.sub.5) or 21.6 kg (MFR.sub.21) 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 or 190° C. under a load of 2.16 kg, 5.0 kg or 21.6 kg.

[0310] b) Density

[0311] Density is measured according to ISO 1183-187. Sample preparation is done by compression moulding in accordance with ISO 17855-2.

[0312] c) Comonomer Content

[0313] Quantification of C4 in polyethylene by NMR spectroscopy (used for carrier polylethylene of the carbon black masterbatch) Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content of the polymer.

[0314] Quantitative .sup.13C{.sup.1H} NMR spectra recorded in the molten-state using a Bruker Avance III 500 NMR spectrometer operating at 500.13 and 125.76 MHz for .sup.1H and .sup.13C respectively. All spectra were recorded using a .sup.13C optimised 7 mm magic-angle spinning (MAS) probehead at 150° C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was packed into a 7 mm outer diameter zirconia MAS rotor and spun at 4 kHz. This setup was chosen primarily for the high sensitivity needed for rapid identification and accurate quantification {klimke06, parkinson07, castignolles09}. Standard single-pulse excitation was employed utilising the transient NOE at short recycle delays of 3 s {pollard04, klimke06} and the RS-HEPT decoupling scheme {fillip05, griffin07}. A total of 1024 (1 k) transients were acquired per spectrum. This setup was chosen due its high sensitivity towards low comonomer contents.

[0315] Quantitative .sup.11C{.sup.1H} NMR spectra were processed, integrated and quantitative properties determined using custom spectral analysis automation programs. All chemical shifts are internally referenced to the bulk methylene signal (δ+) at 30.00 ppm {randall89}.

[0316] Characteristic signals corresponding to the incorporation of 1-butene were observed (randall89) and all contents calculated with respect to all other monomers present in the polymer.

[0317] Characteristic signals resulting from isolated 1-butene incorporation i.e. EEBEE comonomer sequences, were observed. Isolated 1-butene incorporation was quantified using the integral of the signal at 39.9 ppm assigned to the .sub.*B2 sites, accounting for the number of reporting sites per comonomer:

B=I.sub.*B2

[0318] With no other signals indicative of other comonomer sequences, i.e. consecutive comonomer incorporation, observed the total 1-butene comonomer content was calculated based solely on the amount of isolated 1-butene sequences:

B.sub.total=B

[0319] The relative content of ethylene was quantified using the integral of the bulk methylene (□+) signals at 30.00 ppm:

E=(1/2)*I.sub.□+

[0320] The total ethylene comonomer content was calculated based the bulk methylene signals and accounting for ethylene units present in other observed comonomer sequences:

E.sub.total=E+(5/2)*B

[0321] The total mole fraction of 1-butene in the polymer was then calculated as:

fB=B.sub.total/(E.sub.total+B.sub.total)

[0322] The total comonomer incorporation of 1-butene in mole percent was calculated from the mole fraction in the usual manner:

B[mol %]=100*fB

[0323] The total comonomer incorporation of 1-butene in weight percent was calculated from the mole fraction in the standard manner:

B[wt %]=100*fB*56.11/((fB*56.11)+((1−fB)*28.05)) [0324] klimke06 [0325] Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382. [0326] parkinson07 [0327] Parkinson, M., Klimke, K., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2007; 208:2128. [0328] pollard04 [0329] Pollard, M., Klimke, K., Graf, R., Spiess, H. W., Wilhelm, M., Sperber, O., Piel, C., Kaminsky, W., Macromolecules 2004; 37:813. [0330] filip05 [0331] Filip, X., Tripon, C., Filip, C., J. Mag. Resn. 2005, 176, 239 [0332] griffin07 [0333] Griffin, J. M., Tripon, C., Samoson, A., Filip, C., and Brown, S. P., Mag. Res. in Chem. 2007 45, S1, S198 [0334] castignolles09 [0335] Castignolles, P., Graf, R., Parkinson, M., Wilhelm, M., Gaborieau, M., Polymer 50 (2009) 2373 [0336] randall89 [0337] J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201.

[0338] Quantification of C2, iPP (Continuous C3), LDPE and Polyethylene Short Chain Branches

[0339] Quantitative .sup.13C{.sup.1H} NMR spectra were recorded in the solution-state using a Bruker AvanceIII 400 MHz NMR spectrometer operating at 400.15 and 100.62 MHz for .sup.1H and .sup.13C respectively. All spectra were recorded using a .sup.13C optimised 10 mm extended temperature probehead at 125° C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was dissolved in 3 ml of 1,2-tetrachloroethane-d.sub.2 (TCE-d.sub.2) along with chromium-(III)-acetylacetonate (Cr(acac).sub.3) resulting in a 65 mM solution of relaxation agent in solvent {singh09}. To ensure a homogenous solution, after initial sample preparation in a heat block, the NMR tube was further heated in a rotatory oven for at least 1 hour. Upon insertion into the magnet the tube was spun at 10 Hz. This setup was chosen primarily for the high resolution and quantitatively needed for accurate ethylene content quantification. Standard single-pulse excitation was employed without NOE, using an optimised tip angle, 1 s recycle delay and a bi-level WALTZ16 decoupling scheme {zhou07, busico07}. A total of 6144 (6 k) transients were acquired per spectra.

[0340] Quantitative .sup.13C{.sup.1H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals using proprietary computer programs. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm using the chemical shift of the solvent. Characteristic signals corresponding to polyethylene with different short chain branches (1, B2, B4, B5, E6plus) and polypropylene were observed {randall89, brandolini00}.

[0341] Characteristic signals corresponding to the presence of polyethylene containing isolated 1 branches (starB1 33.3 ppm), isolated B2 branches (starB2 39.8 ppm), isolated B4 branches (twoB4 23.4 ppm), isolated B5 branches (threeB5 32.8 ppm), all branches longer than 4 carbons (starB4plus 38.3 ppm) and the third carbon from a saturated aliphatic chain end (3 s 32.2 ppm) were observed. The intensity of the combined ethylene backbone methine carbons (ddg) containing the polyethylene backbone carbons (dd 30.0 ppm), γ-carbons (g 29.6 ppm) the 4 s and the threeB4 carbon (to be compensated for later on) is taken between 30.9 ppm and 29.3 ppm excluding the Tββ from polypropylene. The amount of C2 related carbons was quantified using all mentioned signals according to the following equation:

fC.sub.C2total=(Iddg−ItwoB4)+(IstarB1*6)+(IstarB2*7)+(ItwoB4*9)+I(threeB5*10)+((IstarB4plus−ItwoB4−IthreeB5)*7)+(13s*3)

[0342] Characteristic signals corresponding to the presence of polypropylene (iPP, continuous C3)) were observed at 46.7 ppm, 29.0 ppm and 22.0 ppm. The amount of PP related carbons was quantified using the integral of Sαα at 46.6 ppm:

fC.sub.PP=Isαα*3

The weight percent of the C2 fraction and the polypropylene can be quantified according following equations:

wt.sub.C2fraction=fC.sub.C2total*100/(fC.sub.C2total+fC.sub.PP)

wt.sub.PP=fC.sub.PP*100/(fC.sub.C2total+fC.sub.PP)

[0343] Characteristic signals corresponding to various short chain branches were observed and their weight percentages quantified as the related branch would be an alpha-olefin, starting by quantifying the weight fraction of each:

fwtC2=fC.sub.C2total−((IstarB1*3)−(IstarB2*4)−(ItwoB4*6)−(IthreeB5*7)

fwtC3(isolated C3)=IstarB1*3

fwtC4=IstarB2*4

fwtC6=ItwoB4*6

fwtC7=IthreeB5*7

[0344] Normalisation of all weight fractions leads to the amount of weight percent for all related branches:

fsum.sub.wt.-% total=fwtC2+fwtC3+fwtC4+fwtC6+fwtC7+fC.sub.PP

wtC2total=fwtC2*100/fsum.sub.wt.-% total

wtC3total=fwtC3*100/fsum.sub.wt.-% total

wtC4total=fwtC4*100/fsum.sub.wt.-% total

wtC6total=fwtC6*100/fsum.sub.wt.-% total

wtC7total=fwtC7*100/fsum.sub.wt.-% total

[0345] The content of LDPE can be estimated assuming the B5 branch, which only arises from ethylene being polymerised under high pressure process, being almost constant in LDPE.

[0346] We found the average amount of B5 if quantified as C7 at 1.46 wt.-%. With this assumption it is possible to estimate the LDPE content within certain ranges (approximately between 20 wt.-% and 80 wt.-%), which are depending on the SNR ratio of the threeB5 signal:

wt.-% LDPE=wtC7total*100/1.46

REFERENCES

[0347] zhou07 Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225 [0348] busico07 Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128 [0349] singh09 Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009), 475 [0350] randall89 J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201. [0351] brandolini00 A. J. Brandolini, D. D. Hills, NMR Spectra of Polymers and Polymer Additives, Marcel Dekker Inc., 2000

[0352] d) Impact Strength

[0353] 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 80×10×4 mm prepared according to ISO 17855-2.

[0354] e) Tensile Testing of 5A Specimen

[0355] For tensile testing, dog bone specimens of 5A are prepared according to ISO 527-2/5A by die cutting from compression moulded plaques of 2 mm′ thickness. If ageing is needed, 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.

[0356] Tensile properties are measured according to ISO 527-1/2 at 23° C. and 50% relative humidity with Alwetron R24, 1 kN load cell. Tensile testing speed is 50 mm/min, grip distance is 50 mm and gauge length is 20 mm.

[0357] f) Rheological Measurements

[0358] Dynamic Shear Measurements (frequency sweep measurements) The characterisation of melt of polymer composition or polymer as given above or below in the context by dynamic shear measurements complies with ISO standards 6721-1 and 6721-10. The measurements were performed on an Anton Paar MCR501 stress controlled rotational rheometer, equipped with a 25 mm parallel plate geometry. Measurements were undertaken on compression moulded plates, using nitrogen atmosphere and setting a strain within the linear viscoelastic regime. The oscillatory shear tests were done at 190° C. applying a frequency range between 0.01 and 600 rad/s and setting a gap of 1.3 mm.

[0359] In a dynamic shear experiment the probe is subjected to a homogeneous deformation at a sinusoidal varying shear strain or shear stress (strain and stress controlled mode, respectively). On a controlled strain experiment, the probe is subjected to a sinusoidal strain that can be expressed by

γ(t)=γ.sub.0 sin(ωt)  (1)

If the applied strain is within the linear viscoelastic regime, the resulting sinusoidal stress response can be given by

σ(t)=σ.sub.0 sin(ωt+δ)  (2)

where
σ.sub.0 and γ.sub.0 are the stress and strain amplitudes, respectively
ω is the angular frequency
δ is the phase shift (loss angle between applied strain and stress response)
t is the time

[0360] Dynamic test results are typically expressed by means of several different rheological functions, namely the shear storage modulus G′, the shear loss modulus, G″, the complex shear modulus, G*, the complex shear viscosity, η*, the dynamic shear viscosity, η′, the out-of-phase component of the complex shear viscosity r″ and the loss tangent, tan δ which can be expressed as follows:

[00001]$\begin{array}{cc}{G}^{\prime }=\frac{{\sigma }_0}{{\gamma }_0}\cos \delta \left[\mathrm{Pa}\right]& \left(3\right)\end{array}$$\begin{array}{cc}{G}^{″}=\frac{{\sigma }_0}{{\gamma }_0}\sin \delta \left[\mathrm{Pa}\right]& \left(4\right)\end{array}$$\begin{array}{cc}{G}^{*}=G^{\prime }+{\mathrm{iG}}^{″}\left[\mathrm{Pa}\right]& \left(5\right)\end{array}$$\begin{array}{cc}{\eta }^{*}={\eta }^{\prime }-i{\eta }^{″}\left[\mathrm{Pa}.s\right]& \left(6\right)\end{array}$$\begin{array}{cc}{\eta }^{\prime }=\frac{G^{″}}{\omega }\left[\mathrm{Pa}.s\right]& \left(7\right)\end{array}$$\begin{array}{cc}{\eta }^{″}=\frac{G^{\prime }}{\omega }\left[\mathrm{Pa}.s\right]& \left(8\right)\end{array}$

[0361] The determination of so-called Shear Thinning Index, which correlates with MWD and is independent of Mw, is done as described in equation 9.

[00002]$\begin{array}{cc}{\mathrm{SHI}}_{\left(x/y\right)}=\frac{{\mathrm{Eta}}^{\star }\mathrm{for}\left(G^{\star }=x\mathrm{kPa}\right)}{{\mathrm{Eta}}^{\star }\mathrm{for}\left(G^{\star }=y\mathrm{kPa}\right)}& \left(9\right)\end{array}$

[0362] For example, the SHI.sub.2.7/210 is defined by the value of the complex viscosity, in Pa s, determined for a value of G* equal to 2.7 kPa, divided by the value of the complex viscosity, in Pa s, determined for a value of G* equal to 210 kPa.

[0363] The values of storage modulus (G′), loss modulus (G″), complex modulus (G*) and complex viscosity (η*) were obtained as a function of frequency (ω).

[0364] Thereby, e.g. η*.sub.300 rad/s (eta*.sub.300 rad/s) is used as abbreviation for the complex viscosity at the frequency of 300 rad/s and η*.sub.0.05 rad/s (eta*.sub.0.05 rad/s) is used as abbreviation for the complex viscosity at the frequency of 0.05 rad/s.

[0365] The loss tangent tan (delta) is defined as the ratio of the loss modulus (G″) and the storage modulus (G′) at a given frequency. Thereby, e.g. tan.sub.0.05 is used as abbreviation for the ratio of the loss modulus (G″) and the storage modulus (G′) at 0.05 rad/s and tan.sub.300 is used as abbreviation for the ratio of the loss modulus (G″) and the storage modulus (G′) at 300 rad/s.

[0366] The elasticity balance tan.sub.0.05/tan.sub.300 is defined as the ratio of the loss tangent tan.sub.0.05 and the loss tangent tan.sub.300.

[0367] Besides the above mentioned rheological functions one can also determine other rheological parameters such as the so-called elasticity index EI(x). The elasticity index EI(x) is the value of the storage modulus (G) determined for a value of the loss modulus (G″) of x kPa and can be described by equation 10.

EI(x)=G′ for (G″=x kPa)[Pa]  (10)

[0368] For example, the E/(5 kPa) is the defined by the value of the storage modulus (G′), determined for a value of G″ equal to 5 kPa.

[0369] The polydispersity index, PI, is defined by equation 11.

[00003]$\begin{array}{cc}\mathrm{PI}=\frac{-10^5}{G^{\prime }\left({\omega }_{COP}\right)},{\omega }_{\mathrm{COP}}=\omega \mathrm{for}\left(G^{\prime }=G^{″}\right)& \left(11\right)\end{array}$

where ω.sub.COP is the cross-over angular frequency, determined as the angular frequency for which the storage modulus, G′, equals the loss modulus, G″.

[0370] The values are determined by means of a single point interpolation procedure, as defined by Rheoplus software. In situations for which a given G* value is not experimentally reached, the value is determined by means of an extrapolation, using the same procedure as before.

[0371] In both cases (interpolation or extrapolation), the option from Rheoplus “Interpolate y-values to x-values from parameter” and the “logarithmic interpolation type” were applied.

REFERENCES

[0372] [1] Rheological characterization of polyethylene fractions” Heino, E. L., Lehtinen, A., Tanner J., Seppälä, J., Neste Oy, Porvoo, Finland, Theor. Appl. Rheol., Proc. Int. Congr. Rheol, 11th (1992), 1, 360-362 [0373] [2] The influence of molecular structure on some rheological properties of polyethylene”, Heino, E. L., Borealis Polymers Oy, Porvoo, Finland, Annual Transactions of the Nordic Rheology Society, 1995). [0374] [3] Definition of terms relating to the non-ultimate mechanical properties of polymers, Pure & Appl. Chem., Vol. 70, No. 3, pp. 701-754, 1998.

[0375] g) ESCR (Bell Test, h)

[0376] By the term ESCR (environmental stress cracking resistance) is meant the resistance of the polymer to crack formation under the action of mechanical stress and a reagent in the form of a surfactant. The ESCR is determined in accordance with IEC 60811-406, method B. The reagent employed is 10 weight % Igepal CO 630 in water. The materials were prepared according to instructions for HDPE as follows: The materials were pressed at 165° C. to a thickness of 1.75-2.00 mm. The notch was 0.30-0.40 mm deep.

[0377] h) Shore D Hardness

[0378] Two different Shore D hardness measurements were conducted:

[0379] Firstly, Shore D hardness is determined according to ISO 868 on moulded specimen with a thickness of 4 mm. The shore hardness is determined after 1 sec, 3 sec or 15 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 80×10×4 mm.

[0380] i) Strain Hardening (SH) Modulus

[0381] The strain hardening test is a modified tensile test performed at 80° C. on a specially prepared thin sample. The Strain Hardening Modulus (MPa), <Gp>, is calculated from True Strain-True Stress curves; by using the slope of the curve in the region of True Strain, λ, is between 8 and 12.

[0382] The true strain, λ, is calculated from the length, l (mm), and the gauge length, l0 (mm), as shown by Equation 1.

[00004]$\begin{array}{cc}\lambda =\frac{l}{l_0}=1+\frac{\Delta l}{l_0}& \left(1\right)\end{array}$

where Δl is the increase in the specimen length between the gauge marks, (mm). The true stress, σtrue (MPa), is calculated according to formula 2, assuming conservation of volume between the gauge marks:

σ.sub.true=σ.sub.nλ  (2)

where σ.sub.n is the engineering stress.

[0383] The Neo-Hookean constitutive model (Equation 3) is used to fit the true strain-true stress data from which <Gp> (MPa) for 8<λ<12 is calculated.

[00005]$\begin{array}{cc}{\sigma }_{\mathrm{true}}=\frac{<\mathrm{Gp}>}{20}\left({\lambda }^2-\frac{1}{\lambda }\right)+C& \left(3\right)\end{array}$

where C is a mathematical parameter of the constitutive model describing the yield stress extrapolated to λ=0.

[0384] Initially five specimens are measured. If the variation coefficient of <Gp> is greater than 2.5%, then two extra specimens are measured. In case straining of the test bar takes place in the clamps the test result is discarded.

[0385] The PE granules of materials were compression molded in sheets of 0.30 mm thickness according to the press parameters as provided in ISO 17855-2.

[0386] After compression molding of the sheets, the sheets were annealed to remove any orientation or thermal history and maintain isotropic sheets. Annealing of the sheets was performed for 1 h in an oven at a temperature of (120±2) ° C. followed by slowly cooling down to room temperature by switching off the temperature chamber. During this operation free movement of the sheets was allowed.

[0387] Next, the test pieces were punched from the pressed sheets. The specimen geometry of the modified ISO 37:1994 Type 3 (FIG. 3) was used.

[0388] The sample has a large clamping area to prevent grip slip, dimensions given in Table 1.

TABLE-US-00001 TABLE 1 Dimensions of Modified ISO 37: 1994 Type 3 Dimension Size (mm) L start length between clamps 30.0 +/− 0.5  l0 Gauge length 12.5 +/− 0.1  l1 Prismatic length 16.0 +/− 1.0  l3 Total length 70 R1 Radius 10.0 +/− 0.03 R2 Radius 8.06 +/− 0.03 b1 Prismatic width  4.0 +/− 0.01 b2 Clamp width 20.0 +/− 1.0  h Thickness 0.30 + 0.05/0.30 − 0.03

[0389] The punching procedure is carried out in such a way that no deformation, crazes or other irregularities are present in the test pieces.

[0390] The thickness of the samples was measured at three points of the parallel area of the specimen; the lowest measured value of the thickness of these measurements was used for data treatment. [0391] 1. The following procedure is performed on a universal tensile testing machine having controlled temperature chamber and non-contact extensometer: [0392] 2. Condition the test specimens for at least 30 min in the temperature chamber at a temperature of (80±1) ° C. prior to starting the test. [0393] 3. Clamp the test piece on the upper side. [0394] 4. Close the temperature chamber. [0395] 5. Close the lower clamp after reaching the temperature of (80±1) ° C. [0396] 6. Equilibrate the sample for 1 min between the clamps, before the load is applied and measurement starts. [0397] 7. Add a pre-load of 0.5 N at a speed of 5 mm/min. [0398] 8. Extend the test specimen along its major axis at a constant traverse speed (20 mm/min) until the sample breaks. [0399] During the test, the load sustained by the specimen is measured with a load cell of 200 N. The elongation is measured with a non-contact extensometer.

[0400] j) Water Content

[0401] The water content was determined as described in ISO15512:2019 Method A—Extraction with anhydrous methanol. There the test portion is extracted with anhydrous methanol and the extracted water is determined by a coulometric Karl Fischer Titrator.

[0402] k) Cable Extrusion

[0403] The cable extrusion is done on a Nokia-Maillefer cable line. The extruder has five temperature zones with temperatures of 170/175/180/190/190° C. and the extruder head has three zones with temperatures of 210/210/210° C. The extruder screw is a barrier screw of the design Elise. The die is a semi-tube on type with 5.9 mm diameter and the outer diameter of the cable is 5 mm. The compound is extruded on a 3 mm in diameter, solid aluminum conductor to investigate the extrusion properties. Line speed is 75 m/min. The pressure at the screen and the current consumption of the extruder is recorded for each material.

[0404] l) Pressure Deformation

[0405] Pressure test is conducted according to EN 60811-508. An extruded cable sample is placed in an air oven at a 115° C. and subjected to a constant load applied by means of a special indentation device (with a rectangular indentation 0.7 mm wide knife) for 6 hours. The percentage of indentation is measured afterwards using a digital gauge.

[0406] m) Cable Shrinkage

[0407] The shrinkage of the composition is determined with the cable samples obtained from the cable extrusion. The cables are conditioned in the constant room at least 24 hours before the cutting of the samples. The conditions in the constant room are 23±2° C. and 50±5% humidity. Samples are cut to 400 mm at least 2 m away from the cable ends. They are further conditioned in the constant room for 24 hours after which they are place in an oven on a talcum bed at 100° C. for 24 hours. After removal of the sample from the oven they are allowed to cool down to room temperature and then measured. The shrinkage is calculated according to formula below:

[(L.sub.Before−L.sub.After)/L.sub.Before]×100%, wherein L is length.

[0408] n) Tear Resistance

[0409] Tear resistance is 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.

[0410] o) Amount of Limonene

[0411] This method allows nature of a raw mixed-plastic-polyethylene primary recycling blend to be determined.

[0412] Limonene quantification was carried out using solid phase microextraction (HS-SPME-GC-MS) by standard addition.

[0413] 20 mg cryomilled samples were weighed into 20 mL headspace vials and after the addition of limonene in different concentrations and a glass-coated magnetic stir bar, the vial was closed with a magnetic cap lined with silicone/PTFE. Micro capillaries (10 pL) were used to add diluted limonene standards of known concentrations to the sample. Limonene was added to the samples to obtain concentration levels of 1 ppm, 2 ppm, 3 ppm and 4 ppm limonene. For quantification, ion-93 acquired in SIM mode was used. Enrichment of the volatile fraction was carried out by headspace solid phase microextraction with a 2 cm stable flex 50/30 pm DVB/Carboxen/PDMS fibre at 60° C. for 20 minutes. Desorption was carried out directly in the heated injection port of a GCMS system at 270° C.

[0414] GCMS Parameters:

[0415] Column: 30 m HP 5 MS 0.25*0.25

[0416] Injector: Splitless with 0.75 mm SPME Liner, 270° C.

[0417] Temperature program: −10° C. (1 min)

[0418] MS: Single quadrupole, direct interface, 280° C. interface temperature

[0419] Acquisition: SIM scan mode

[0420] Scan parameter: 20-300 amu

[0421] SIM Parameter: m/Z 93, 100 ms dwell time

2. Materials

[0422] PE1 is HE6062, a black bimodal high density polyethylene jacketing compound for energy and communication cables (available from Borealis AG). (see Table 2 for properties) PE2 is HE6063, a natural bimodal high density polyethylene jacketing compound for energy and communication cables (available from Borealis AG). (see Table 2 for properties)

[0423] PE3 is BorSafe™ HE3490-LS-H, a black bimodal high density polyethylene (available from Borealis AG). (see Table 2 for properties)

[0424] PE4 is BorSafe™ HE3493-LS-H, a natural bimodal high density polyethylene (available from Borealis AG). (see Table 2 for properties)

[0425] Purpolen PE is a mixed-plastic-polyethylene primary recycling blend available from MTM plastics. Various samples of Purpolen PE, differing as to density and also rheology, were used in the present study, with the measured properties of these samples given in Table 1.

TABLE-US-00002 TABLE 1 Purpolen PE properties Purpolen PE1 Purpolen PE2 C2 content (wt.-%)   87.42   74.22 Isolated C3 content   0.17   0.32 (wt.-%) C4 content (wt.-%)   0.39   0.21 C6 content (wt.-%)   0.48   0.18 C7 content (wt.-%)   0*   0* Continuous C3   11.53   25.07 content (wt.-%) Limonene content   6 n.m. (ppm) MFR.sub.2 (g/10 min)   0.80   0.91 MFR.sub.5 (g/10 min)   3.55   4.23 MFR.sub.21 (g/10 min) n.m.   89.7 Density (kg/m.sup.3)  983  951 W.sub.COP   67.5   46.9 PI (s.sup.−1)   1.7   2.0 SHI.sub.2.7/210   40.3   45.7 eta.sub.0.05 (Pa .Math. s) 27600 30100 eta.sub.300 (Pa .Math. s)  560  560 XHU (wt.-%)   0.27   0.26 Water content (%)  262 n.m. *0 means lower than the limit of quantification n.m.; not measured.

TABLE-US-00003 TABLE 2 Virgin HDPE properties PE1 PE2 PE3 PE4 C2 content (wt.-%)   97.72   97.47   98.14 n.m. Isolated C3 content   0*   0*    0* n.m. (wt.-%) C4 content (wt.-%)   2.28   2.53    0* n.m. C6 content (wt.-%)   0*   0*    1.86 n.m. C7 content (wt.-%)   0*   0*    0* n.m. Continuous C3   0*   0*    0* n.m. content (wt.-%) CB content (wt.-%)   2.44   0*    2.17 n.m. MFR.sub.2 (g/10 min)   0.5   0.55 n.m. n.m. MFR.sub.5 (g/10 min)   1.85   2    0.25    0.21 MFR.sub.21 (g/10 min)   38.66   40    9.7    6.64 Density (kg/m.sup.3)  959.9  945.8   960   952 W.sub.COP   19.52   21.73    0.75    1.06 PI (s.sup.−1)   1.87   1.9    3.62    2.68 SH modulus (MPa)   25.38   27.43   71   81 SHI.sub.2.7/210   21.95   22.07 n.m. n.m. eta.sub.0.05 (Pa .Math. s) 26074 21897 167000 175000 eta.sub.300 (Pa .Math. s)  815  760  1070  1280 *0 means lower than the limit of quantification n.m.: not measured

3. Experiments

[0426] Compositions were prepared via melt blending on a co-rotating twin screw extruder (ZSK) according to the recipes given in Table 4. The polymer melt mixture was discharged and pelletized. Table 3 further shows the content of these compositions, as measured by quantitative .sup.13C{.sup.1H} NMR measurements. The mechanical properties of the compositions are given in Table 4.

TABLE-US-00004 TABLE 3 Composition of Comparative and Inventive Examples CE1 IE1 IE2 CE2 IE3 PE1 (wt.-%) 50  50  50  — — PE2 (wt.-%) — — — 70  60  PE3 (wt.-%) — 5 10  — — PE4 (wt.-%) — — — — 15  Purpolen PE1 (wt.-%) 50  45  40  — — Purpolen PE2 (wt.-%) — — — 25  25  CB content (wt.-%)   1.3   1.5   1.6    2.21*   2.3* C2 content (wt.-%)  91.8  92.0  93.2  92.3  92.2 Isolated C3 content  0**  0**  0**  0**   0.10 (wt.-%) C4 content (wt.-%)   1.3   1.3   1.2   1.9   1.3 C6 content (wt.-%)  0**  0**  0**  0**   0.4 C7 content (wt.-%)  0**  0**  0**  0**  0** Continuous C3   6.9   6.7   5.6   5.8   6.0 content (wt.-%) *The carbon black in CE2 and IE3 results from the introduction of 6.3 wt.-% of a 40% carbon black masterbatch in the melt blending step. The polyethylene as used as the carrier polyethylene has an MFR.sub.2 of 12.1 g/10 min, an MFR.sub.5 of 34.8 g/10 min, an MFR.sub.21 of 312 g/10 min, a density of 963, eta.sub.0.05 of 870 Pa .Math. s, eta.sub.300 of 291 Pa .Math. s and a C4 content of < 0.4 wt.-%. **0 means lower than the limit of quantification

TABLE-US-00005 TABLE 4 Mechanical properties of Comparative and Inventive Examples CE1 IE1 IE2 CE2 IE3 MFR.sub.2 (g/10 min) 0.51 0.47 0.38 0.60 0.39 MFR.sub.5 (g/10 min) 2.34 1.94 1.70 2.55 1.71 MFR.sub.21 (g/10 min) 48.2 47.1 41.5 49.6 37.5 Density (kg/m.sup.3) 966 966 965 959 959 Impact strength, 23° C., 4.7 5.4 6.6 6.0 7.2 (kJ/m.sup.2) Impact strength, 0° C., 4.1 4.3 4.2 3.9 4.3 (kJ/m.sup.2) W.sub.COP 22.6 16.4 12.5 25.0 11.2 PI (s.sup.−1) 2.3 2.4 2.6 2.0 2.6 SHI.sub.2.7/210 35.7 38.1 41.8 28.6 41.7 eta.sub.0.05 (Pa .Math. s) 28300 32900 36900 24000 38100 eta.sub.300 (Pa .Math. s) 670 710 730 690 740 Bell ESCR (h) 840 1632 >4000 >4000 >4000 Cable shrinkage (%) 1.08 1.12 1.22 0.62 0.73 Pressure deformation (%) 5 6 7 n.m. n.m. SH modulus (MPa) 16.2 17.3 19.3 19.9 23.8 Shore D 15 s (ISO 868) 61.1 61.2 61.4 n.m. n.m. Shore D 3 s (ISO 868) 63.4 63.3 63.3 n.m. n.m. Shore D 1 s (ISO 868) 64.5 64.7 64.9 n.m. n.m. Tensile strain at break, 400 640 580 470 650 5A specimen (%) Tensile stress at break, 14.2 15.1 15.5 15.0 16.8 5A specimen (MPa) Tear resistance (N/mm) 22.8 22.8 23.1 n.m. n.m. Water content (%) 179 299 289 79 13 n.m. = not measured

[0427] As can be seen from Table 4, the addition of either PE4 or PE5 to blends of PE1/PE2 with Purpolen PE has the effect of increasing the Charpy notched impact strength, the tensile strain and stress at break, and particularly ECSR (evaluated by Bell test and/or strain hardening modulus). As can be seen from CE1, when relatively large amounts of recycled material are used, this can result in poor Charpy notched impact strength, ECSR performance and SH modulus being too low. Inclusion of the second virgin high-density polyethylene (C) allows access to black compositions that satisfy the requirements for cabling applications and additionally have a higher recycled content than would be possible without the addition of said second virgin high-density polyethylene (C), a key result, given the ever-stricter requirements regarding the content of recycled material in consumer goods.

[0428] It further can be seen that the simultaneous presence of an amount of continuous C3 units from 5.5 to 6.5 wt.-% and C4 units from 1.20 to 1.40 wt.-% such as in example IE2 and IE3 results in surprisingly high and unexpected Bell ESCR as well as better impact strength (23° C.) with comparable impact strength (0°).