Semiconductor polypropylene composition

Abstract

The present invention relates to a semiconductor composition comprising: (A) 25.0 to 67.5 wt% of a first copolymer of propylene and comonomer units selected from ethylene and alpha-olefins having 4 to 12 carbon atoms, the first copolymer (A) having: a melt flow rate MFR2, measured according to ISO 1133 at 230 DEG C and 2.16 kg, of from 2.0 to 6.0 g / 10 min; a soluble fraction (SF) content of greater than 25.0 to 50.0 wt%, measured according to Crystallization Extraction Method (CRYSTEX), based on the total weight of the first copolymer (A); and the total comonomer content, preferably the ethylene content, determined by means of the Crystallization Extraction Method (CRYSTEX) by means of FT-IR spectroscopy calibrated by means of Quantitative 13C-NMR spectroscopy, based on the total weight of the first copolymer (A), is from 7.5 to 20.0 wt%. (B) 5.0 to 50.0 wt% of a second copolymer of propylene and comonomer units selected from ethylene and alpha-olefins having 4 to 12 carbon atoms, the second copolymer (B) having: a melt flow rate MFR2 of at least 2.0 g / 10 min, measured according to ISO 1133 at 230 DEG C and 2.16 kg; a soluble fraction (SF) content, measured by crystallization extraction (CRYSTEX), of from 12.0 to 25.0 wt%, based on the total weight of the second copolymer (B); and a total comonomer content, preferably an ethylene content, determined by the crystallization extraction method (CRYSTEX) by means of FT-IR spectroscopy calibrated by quantitative 13C-NMR spectroscopy, based on the total weight of the second copolymer (B), from 4.0 to 10.0 wt%; and (C) 15.0 to 35.0 wt% of carbon black, where all weights are based on the total weight of the semiconductor composition, an article comprising the semiconductor composition and the use of the semiconductor composition as an inner and / or outer semiconductor layer of a medium voltage cable.

Description

Technical Field

[0001] This invention relates to a semiconductor composition comprising two copolymers of propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms, which have different total contents of soluble fraction (SF) as determined by crystallization extraction (CRYSTEX), and carbon black; the invention also relates to articles comprising the semiconductor composition; and the use of the semiconductor composition as an inner and / or outer semiconductor layer of medium- and high-voltage cables. Background Technology

[0002] Compositions used for the semiconductor layer in cables typically contain solid conductive fillers, such as about 30% to 50% (wt%) of carbon black, to impart semiconductor properties to these compositions. Such a large amount of conductive filler has the disadvantage of poor miscibility with the polymer components, which can impair the mechanical properties of the semiconductor composition.

[0003] Cross-linked polyethylene resin is widely used as a polymer component due to its durability in the presence of strong electric fields.

[0004] However, due to its crosslinking, XLPE has thermosetting properties.

[0005] In recent years, thermoplastic materials, especially thermoplastic propylene polymers, have been explored as polymer materials for the semiconductor layers in medium-voltage, high-voltage, and ultra-high-voltage (MV, HV, and EHV) cables. Furthermore, transmission system operators are showing increasing interest in recycling end-of-life cable assemblies.

[0006] WO2022 / 200395 discloses a polypropylene composition comprising (a) 10.0 to 16.0 wt% of a copolymer of propylene with comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms, and (b) an α-nucleating agent, wherein the polypropylene composition has an XCS fraction of 25.0 to 50.0 wt%, a comonomer unit amount of at least 23.0 wt%, a melt flow rate (MFR2) of 0.5 to 5.0 g / 10 min, and a flexural modulus not exceeding 470 MPa.

[0007] EP2316882A1 discloses a multiphase polypropylene resin comprising a propylene random copolymer matrix phase and an ethylene-propylene copolymer rubber phase dispersed in the matrix phase, wherein the multiphase polypropylene resin has a melt flow rate (MFR2) of 1.0 to 100 g / 10 min, an XCS fraction of 28 to 50 wt%, and an Mw / Mn ratio of 1.0 to 4.0.

[0008] WO2022 / 122444 discloses a semiconductor composition comprising a multiphase propylene copolymer as a polymer component, which exhibits good electrical conductivity, good mechanical properties, and low water treeing at relatively low amounts of carbon black. The multiphase propylene copolymer has a relatively high content of amorphous phase, which makes the semiconductor composition quite viscous during cable extrusion.

[0009] This invention has discovered that by carefully selecting polymer components, a semiconductor composition with good conductivity, good mechanical properties, and good extrudability can be obtained, thereby enabling a further reduction in the amount of carbon black. Cables containing this semiconductor composition as a semiconductor layer exhibit good volume resistivity and excellent electrical breakdown strength, making them particularly suitable for medium- and high-voltage cables. Summary of the Invention

[0010] In a first aspect, the present invention relates to a semiconductor composition comprising:

[0011] (A) 25.0 to 67.5 wt%, preferably 35.0 to 62.5 wt%, more preferably 40.0 to 61.0 wt%, and most preferably 45.0 to 60.0 wt% of a first copolymer of propylene and comonomer units, said comonomer units being selected from ethylene and α-olefins having 4 to 12 carbon atoms, the first copolymer (A) having:

[0012] According to ISO 1133, the melt flow rate MFR2, measured at 230°C and 2.16 kg, is 2.0 to 6.0 g / 10 min, preferably 2.5 to 5.5 g / 10 min, more preferably 3.0 to 5.0 g / 10 min, and most preferably 3.3 to 4.5 g / 10 min.

[0013] Based on the total weight of the first copolymer (A), the content of the soluble fraction (SF), determined by crystallization extraction (CRYSTEX), is greater than 25.0 to 50.0 wt%, preferably 30.0 to 47.5 wt%, and most preferably 32.5 to 45.0 wt%; and

[0014] Based on the total weight of the first copolymer (A), quantitative analysis was performed using the crystallization extraction method (CRYSTEX). 13 The total comonomer content determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is preferably ethylene content, ranging from 7.5 to 20.0 wt%, more preferably from 9.0 to 17.5 wt%, and most preferably from 10.0 to 15.0 wt%.

[0015] (B) 5.0 to 50.0 wt%, preferably 10.0 to 40.0 wt%, more preferably 11.0 to 35.0 wt%, and most preferably 12.0 to 25.0 wt% of a second copolymer of propylene and comonomer units, said comonomer units being selected from ethylene and α-olefins having 4 to 12 carbon atoms, the second copolymer (B) having:

[0016] The melt flow rate MFR2, as determined according to ISO 1133 at 230°C and 2.16 kg, is at least 2.0 g / 10 min, for example 2.0 to 2000 g / 10 min, preferably 3.0 to 500 g / 10 min, even more preferably 4.0 to 100 g / 10 min, and most preferably 5.0 to 30.0 g / 10 min;

[0017] Based on the total weight of the second copolymer (B), the content of the soluble fraction (SF), determined by crystallization extraction (CRYSTEX), is 12.0 to 25.0 wt%, preferably 13.5 to 22.5 wt%, and most preferably 15.0 to 20.0 wt%; and

[0018] Based on the total weight of the second copolymer (B), quantitative analysis was performed using the crystallization extraction method (CRYSTEX). 13 The total comonomer content determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy, preferably ethylene content, is 4.0 to 10.0 wt%, more preferably 5.0 to 9.5 wt%, and more preferably 6.0 to 9.0 wt%; and

[0019] (C) 15.0 to 35.0 wt%, preferably 17.5 to 32.5 wt%, more preferably 20.0 to 30.0 wt%, and most preferably 23.0 to 28.0 wt% carbon black.

[0020] All weights are based on the total weight of the semiconductor composition.

[0021] In another aspect, the present invention relates to an article comprising the semiconductor composition described above or below.

[0022] Preferably, the article is a cable having a semiconductor layer, more preferably an inner and / or outer semiconductor layer comprising a semiconductor composition as described above or below.

[0023] In another aspect, the present invention relates to the use of the above-described or below-described semiconductor compositions as inner and / or outer semiconductor layers of medium-voltage cables.

[0024] definition

[0025] Multiphase polypropylene is a propylene-based copolymer having a crystalline matrix phase and an elastomeric phase dispersed therein. The crystalline matrix phase can be a propylene homopolymer or a random copolymer of propylene and at least one α-olefin comonomer. The elastomeric phase can be a propylene copolymer with a high comonomer content, which is not randomly distributed in the polymer chain, but rather distributed in comonomer-rich block structures and propylene-rich block structures.

[0026] Typically, the difference between multiphase polypropylene and single-phase propylene copolymers is that multiphase polypropylene exhibits two distinct glass transition temperatures (Tg) attributed to the matrix phase and the elastomer phase, respectively.

[0027] Propylene homopolymer is a polymer that is essentially composed of propylene monomer units. Due to impurities, especially those introduced during commercial polymerization processes, propylene homopolymer may contain up to 0.1 mol% of comonomer units, preferably up to 0.05 mol% of comonomer units, and most preferably up to 0.01 mol% of comonomer units.

[0028] Propylene random copolymers are copolymers of propylene monomer units and comonomer units, wherein the comonomer units are randomly distributed within the polypropylene chain. Therefore, a propylene random copolymer comprises, based on the total amount of the propylene random copolymer, a crystalline fraction (CF) of greater than 85 wt%, for example at least 88 wt%, and most preferably at least 90 wt%, as determined by crystallization extraction (CRYSTEX). Accordingly, the propylene random copolymer does not contain an elastomeric polymer phase dispersed therein.

[0029] Typically, a propylene polymer containing at least two propylene polymer fractions (components) is referred to as "multimodal," meaning that these fractions are produced under different polymerization conditions (preferably through polymerization in multiple stages under different conditions), resulting in each fraction having a different (weight-average) molecular weight and / or different comonomer content. The prefix "multimodal" refers to the number of different polymer fractions constituting the propylene polymer. As examples of multimodal propylene polymers, a propylene polymer consisting of only two fractions is called "bimodal," while a propylene polymer consisting of only three fractions is called "trimodal."

[0030] A single-peak propylene polymer consists of only one fraction.

[0031] Therefore, the term "different" means that the propylene polymer fractions differ from each other in at least one property, preferably in weight-average molecular weight (which can also be measured by the different melt flow rates of the fractions) or comonomer content or both.

[0032] Viscosity reduction cracking is a post-reactor chemical process used to modify semi-crystalline polymers, such as propylene polymers. During the viscosity reduction cracking process, the propylene polymer backbone is degraded via β-cracking through peroxides (e.g., organic peroxides). This degradation is typically used to increase melt flow rate and narrow the molecular weight distribution.

[0033] In the following text, unless otherwise stated, quantities are expressed in weight % (wt%). Detailed Implementation

[0034] Semiconductor Composition

[0035] In a first aspect, the present invention relates to a semiconductor composition comprising:

[0036] (A) 25.0 to 67.5 wt%, preferably 35.0 to 62.5 wt%, more preferably 40.0 to 61.0 wt%, and most preferably 45.0 to 60.0 wt% of a first copolymer of propylene and comonomer units, said comonomer units being selected from ethylene and α-olefins having 4 to 12 carbon atoms, the first copolymer (A) having:

[0037] According to ISO 1133, the melt flow rate MFR2, measured at 230°C and 2.16 kg, is 2.0 to 6.0 g / 10 min, preferably 2.5 to 5.5 g / 10 min, more preferably 3.0 to 5.0 g / 10 min, and most preferably 3.3 to 4.5 g / 10 min.

[0038] Based on the total weight of the first copolymer (A), the soluble fraction (SF) content, determined by crystallization extraction (CRYSTEX), is greater than 25.0 to 50.0 wt%, preferably 30.0 to 47.5 wt%, and most preferably 32.5 to 45.0 wt%; and

[0039] Based on the total weight of the first copolymer (A), quantitative analysis was performed using the crystallization extraction method (CRYSTEX). 13 The total comonomer content determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy, preferably ethylene content, is 7.5 to 20.0 wt%, more preferably 9.0 to 17.5 wt%, and most preferably 10.0 to 15.0 wt%.

[0040] (B) 5.0 to 50.0 wt%, preferably 10.0 to 40.0 wt%, more preferably 11.0 to 35.0 wt%, and most preferably 12.0 to 25.0 wt% of a second copolymer of propylene and comonomer units, said comonomer units being selected from ethylene and α-olefins having 4 to 12 carbon atoms, wherein the second copolymer (B) has:

[0041] The melt flow rate MFR2, as determined according to ISO 1133 at 230°C and 2.16 kg, is at least 2.0 g / 10 min, for example 2.0 to 2000 g / 10 min, preferably 3.0 to 500 g / 10 min, more preferably 4.0 to 100 g / 10 min, and most preferably 5.0 to 30.0 g / 10 min;

[0042] Based on the total weight of the second copolymer (B), the soluble fraction (SF) content, determined by crystallization extraction (CRYSTEX), is 12.0 to 25.0 wt%, preferably 13.5 to 22.5 wt%, and most preferably 15.0 to 20.0 wt%; and

[0043] Based on the total weight of the second copolymer (B), quantitative analysis was performed using the crystallization extraction method (CRYSTEX). 13 The total comonomer content determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy, preferably ethylene content, is 4.0 to 10.0 wt%, more preferably 5.0 to 9.5 wt%, and more preferably 6.0 to 9.0 wt%; and

[0044] (C) 15.0 to 35.0 wt%, preferably 17.5 to 32.5 wt%, more preferably 20.0 to 30.0 wt%, and most preferably 23.0 to 28.0 wt% carbon black.

[0045] All weights are based on the total weight of the semiconductor composition.

[0046] The semiconductor composition comprises components (A), (B) and (C) as described above or below.

[0047] The amounts of components (A), (B) and (C) in the semiconductor composition are preferably 90.0 to 100 wt%, more preferably 95.0 to 100 wt%, and most preferably 97.5 to 100 wt%.

[0048] Based on the total weight of the semiconductor composition, the semiconductor composition may also contain a polymer component, preferably in an amount of 0.0 to 10.0 wt%, which is different from the first copolymer (A) and the second copolymer (B).

[0049] Other suitable polymer components include, for example, polyolefins (D) functionalized with monocarboxylic or polycarboxylic compounds or derivatives thereof, wherein the functionalized polyolefin (C) is different from the first copolymer (A) and the second copolymer (B).

[0050] Preferably, the functionalized polyolefin (D) is present in the semiconductor composition in an amount not exceeding 5.0 wt%, preferably 0.05 to 2.5 wt%, more preferably 0.1 to 1.0 wt%, and most preferably 0.2 to 0.8 wt%, based on the total weight of the semiconductor composition.

[0051] In addition to components (A), (B), and optionally (D), the semiconductor composition may further comprise a polymer component. However, preferably, the semiconductor composition does not further comprise a polymer component other than components (A), (B), and optionally (D), i.e., the polymer component of the semiconductor composition consists of components (A), (B), and optionally (D). In one embodiment, the polymer component of the semiconductor composition consists of components (A), (B), and (C). In another embodiment, the polymer component of the semiconductor composition consists of components (A) and (B).

[0052] Semiconductor compositions preferably do not contain, i.e. do not contain, polymers containing polar monomer units (such as acetates or acrylates or derivatives thereof).

[0053] Preferably, the weight ratio of the first copolymer (A) to the second copolymer (B) in the semiconductor composition is from 1.5:1.0 to 10.0:1.0, more preferably from 2.0:1.0 to 7.5:1.0, and most preferably from 2.5:1.0 to 5.0:1.0.

[0054] Based on the total weight of the semiconductor composition, the amount of polymer components in the semiconductor composition, preferably components (A), (B) and optional (D), more preferably components (A) and (B) is 65.0 to 85.0 wt%, more preferably 67.5 to 82.5 wt%, more preferably 70.0 to 80.0 wt%, and most preferably 72.0 to 77.0 wt%.

[0055] Semiconductor compositions may contain other components, such as additives, which may optionally be added in the form of a mixture with the carrier polymer (e.g., in a so-called masterbatch). Carbon black (C) may also be added in masterbatch form. In such cases, the carrier polymer is not counted as an amount of polymer component. The amounts of additives and carrier polymer in any masterbatch are counted in the total amount (100 wt%) of the polymer composition. If present, additives are preferably selected from antioxidants, stabilizers, processing aids, flame retardants, water tree inhibitors, acid or ion scavengers, and inorganic fillers known in the polymer field.

[0056] The amount of other components in the semiconductor composition is preferably no more than 10.0 wt% of the total amount of the semiconductor composition, for example, 0 to 5.0 wt% or 0 to 2.5 wt%.

[0057] Preferably, the semiconductor composition does not contain, i.e., is free of, 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ). In cable applications, where the semiconductor composition is used in the semiconductor layer, TMQ tends to diffuse partially from the semiconductor layer into the insulation layer, potentially causing a yellow discoloration of the insulation layer.

[0058] In one embodiment, the semiconductor composition comprises components (A), (B), and (C), optional component (D), and optional other components (e.g., additives), preferably consisting of components (A), (B), and (C), optional component (D), and optional other components (e.g., additives), but free of polymers containing polar monomer units and 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ); preferably, the semiconductor composition comprises components (A), (B), and (C) and optional other components (e.g., additives), more preferably consisting of components (A), (B), and (C) and optional other components (e.g., additives), but free of polymers containing polar monomer units and 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ).

[0059] In another embodiment, the semiconductor composition comprises components (A), (B), (C) and optional component (D), preferably components (A), (B) and (C).

[0060] The melt flow rate MFR5 (230°C, 5.0 kg load) of the semiconductor composition is preferably 2.0 to 100 g / 10 min, more preferably 3.0 to 75 g / 10 min, even more preferably 4.0 to 50 g / 10 min, and most preferably 5.0 to 12 g / 10 min.

[0061] In addition, the melt flow rate (MFR) of the semiconductor composition 10 (230°C, 10kg load) Preferably 12 to 600 g / 10min, more preferably 18 to 450 g / 10min, even more preferably 22 to 300 g / 10min, and most preferably 25 to 50 g / 10min.

[0062] The density of the semiconductor composition is preferably from 0.850 to 1.200 g / cm³. 3 More preferably, it is 0.900 to 1.100 g / cm³. 3 The optimal value is 0.950 to 1.075 g / cm³. 3 .

[0063] Furthermore, when measured at 23°C using a 1mm×100mm×15mm strip sample, the volume resistivity (VR) of the semiconductor composition is preferably 6.0 to 55.0 Ohm·cm, more preferably 7.0 to 52.5 Ohm·cm, and most preferably 8.0 to 50.0 Ohm·cm.

[0064] In some embodiments, when measured at 23°C using a 1mm×100mm×15mm strip sample, the volume resistivity can be as low as 20.0 Ohm·cm, preferably as low as 17.5 Ohm·cm, and most preferably as low as 15.0 Ohm·cm.

[0065] Furthermore, the tensile strength of the semiconductor composition is preferably at least 10.0 MPa, more preferably at least 12.5 MPa, and most preferably at least 14.0 MPa.

[0066] The upper limit of the tensile strength is preferably not more than 25.0 MPa, more preferably not more than 22.5 MPa, and most preferably not more than 20.0 MPa.

[0067] Furthermore, the elongation at break of the semiconductor composition is preferably at least 350%, more preferably at least 400%, and most preferably at least 450%.

[0068] The upper limit of the elongation at break is preferably no more than 750%, more preferably no more than 700%, and most preferably no more than 650%.

[0069] Therefore, the semiconductor composition according to the present invention unexpectedly exhibits a good balance of performance in terms of processability, conductivity, mechanical properties and strip surface smoothness.

[0070] Preferably, the semiconductor composition is not cross-linked.

[0071] As is well known in the art, crosslinked polymer compositions typically possess a network structure, namely, interpolymer crosslinks (bridges). These bridges can be introduced by generating free radicals in the polymer chains (e.g., through reaction with peroxides or exposure to radiation) or by introducing functional groups that readily react chemically with another of the said functional groups into the polymer chains. During the crosslinking process, the crosslinked polymer composition becomes thermosetting.

[0072] Preferably, the semiconductor composition is thermoplastic.

[0073] Preferably, the semiconductor composition is prepared by melt blending components (A), (B) and (C) as well as optional component (D) and optional other components (e.g., optional additives and other polymer components), all as described above or below.

[0074] First copolymer (A)

[0075] The first copolymer (A) is a copolymer of propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms.

[0076] The comonomer unit is selected from ethylene and α-olefins having 4 to 12 carbon atoms, such as ethylene, 1-butene, 1-hexene and 1-octene, preferably selected from ethylene, 1-butene and 1-hexene, and most preferably ethylene.

[0077] In a preferred embodiment, the first copolymer (A) is a copolymer of propylene and ethylene.

[0078] Based on the total weight of the first copolymer (A), the quantification was performed using the crystallization extraction method (CRYSTEX). 13 The total monomer content (preferably ethylene content) of the first copolymer (A) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is 7.5 to 20.0 wt%, preferably 9.0 to 17.5 wt%, and most preferably 10.0 to 15.0 wt%.

[0079] Preferably, the total weight of the first copolymer (A) is used as a basis for quantitative determination by crystallization extraction (CRYSTEX). 13 The total propylene content of the first copolymer (A), as determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy, is 80.0 to 92.5 wt%, preferably 82.5 to 91.0 wt%, and most preferably 85.0 to 90.0 wt%.

[0080] The first copolymer is preferably composed of propylene and ethylene. Therefore, preferably, the sum of the total ethylene content and the total propylene content accounts for 100 wt% of the propylene and ethylene copolymer.

[0081] Furthermore, the melt flow rate (MFR2) of the first copolymer (A), as determined according to ISO 1133 at 230°C and 2.16 kg, is 2.0 to 6.0 g / 10 min, preferably 2.5 to 5.5 g / 10 min, more preferably 3.0 to 5.0 g / 10 min, and most preferably 3.3 to 4.5 g / 10 min.

[0082] Preferably, the first copolymer (A) is a multiphase propylene copolymer.

[0083] The multiphase propylene copolymer has a matrix phase and an elastomeric phase dispersed in the matrix phase.

[0084] The matrix phase is preferably a random copolymer of propylene and ethylene.

[0085] In the first copolymer (A) (e.g., a multiphase propylene copolymer), the matrix phase and the elastomer phase are often not precisely distinguishable from each other. Several methods are known to characterize the matrix and elastomer phases of multiphase propylene copolymers. One method is crystallization extraction (CRYSTEX).

[0086] This method will be described in the determination method section below. Trichlorobenzene (TCB) is thus used as a solvent to characterize the polymer fraction of the polypropylene composition. The crystalline fraction (CF) contains the majority of the matrix phase and only a small portion of the elastomeric phase, while the soluble fraction (SF) contains the majority of the elastomeric phase and only a small portion of the matrix phase. In some cases, this method can yield more useful data than xylene extraction because the crystalline fraction (CF) and soluble fraction (SF) correspond more accurately to the matrix and elastomeric phases, respectively. Because xylene extraction and crystallization extraction (CRYSTEX) use different separation methods, the characteristics of the XCS / XCI fraction and the crystalline / soluble fraction (CF / SF) fraction are not entirely identical, meaning that the amounts and properties of the matrix and elastomeric phases may also differ.

[0087] Typically, the crystalline fraction (CF) and soluble fraction (SF) content of a composition are only related to its polymer components, i.e., excluding other insoluble components, and therefore do not participate in the dissolution and crystallization cycles described in the determination methods below.

[0088] In this embodiment, both the first copolymer (A) and the second copolymer (B) are generally completely soluble in trichlorobenzene (TCB), therefore the crystalline fraction (CF) content and the soluble fraction (SF) content relate to the total content of the polyolefin composition. Therefore, the crystalline fraction (CF) content and the soluble fraction (SF) content preferably constitute 100% of the first copolymer (A) and the second copolymer (B).

[0089] Based on the total weight of the first copolymer (A), the content of the crystal fraction (CF) of the first copolymer (A) as determined by crystallization extraction (CRYSTEX) is preferably 50.0 to 75.0 wt%, more preferably 52.5 to 70.0 wt%, and most preferably 55.0 to 67.5 wt%.

[0090] Based on the total amount of monomer units in the crystalline fraction (CF), the crystalline fraction (CF) is quantified by crystallization extraction (CRYSTEX). 13 The comonomer content determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is preferably ethylene content (C2(CF)), preferably 1.0 to 15.0 wt%, more preferably 2.0 to 10.0 wt%, and most preferably 3.0 to 8.5 wt%.

[0091] Furthermore, the intrinsic viscosity (iV(CF)) of the crystalline fraction (CF) as determined according to ISO 1628-3 is preferably 175 to 300 cm⁻¹. 3 / g, more preferably 185 to 275 cm 3 / g, most preferably 200 to 250 cm 3 / g.

[0092] Based on the total weight of the first copolymer (A), the soluble fraction (SF) content of the first copolymer (A) as determined by crystallization extraction (CRYSTEX) is greater than 25.0 to 50.0 wt%, preferably 30.0 to 47.5 wt%, and most preferably 32.5 to 45.0 wt%.

[0093] Based on the total amount of monomer units in the soluble fraction (SF), the soluble fraction (SF) is obtained by quantitative analysis. 13 The comonomer content determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is preferably ethylene content (C2(SF)), preferably 20.0 to 35.0 wt%, more preferably 21.5 to 32.5 wt%, and most preferably 22.5 to 30.0 wt%.

[0094] Furthermore, the intrinsic viscosity (iV(SF)) of the soluble fraction (SF) as determined according to ISO 1628-3 is preferably 150 to 250 cm⁻¹. 3 / g, more preferably 165 to 235 cm 3 The most preferred value is 175 to 225 cm³ / g. 3 / g.

[0095] Preferably, the crystalline fraction (CF) and the soluble fraction (SF) comprise 100% of the first copolymer (A).

[0096] The flexural modulus of the first copolymer (A), as determined according to ISO 178 Method A, is preferably not more than 470 MPa, for example, from 130 MPa to 425 MPa, more preferably from 150 MPa to 400 MPa, and most preferably from 175 MPa to 390 MPa.

[0097] Furthermore, the Charpy notched impact strength of the first copolymer (A) at 23°C, as determined according to ISO 179-1 / 1eA, is preferably 40 to 110 kJ / m. 2 More preferably 50 to 100 kJ / m 2 The optimal value is 55 to 95 kJ / m 2 .

[0098] Furthermore, the melt temperature Tm of the first copolymer (A), as determined by DSC analysis according to ISO 11357 / Part 3 / Method C2, is preferably 140 to 159°C, more preferably 142 to 155°C, and most preferably 145 to 153°C.

[0099] Furthermore, the crystallization temperature Tc of the first copolymer (A), as determined by DSC analysis according to ISO 11357 / Part 3 / Method C2, is preferably 85 to 125°C, more preferably 88 to 122°C, and most preferably 90 to 120°C.

[0100] The difference between the melting temperature and the crystallization temperature, Tm-Tc, is preferably 20 to 70°C, more preferably 25 to 60°C, and most preferably 30 to 55°C.

[0101] The total intrinsic viscosity of the first copolymer (A), as determined according to ISO 1628-3, is preferably between 150 and 350 cm⁻¹. 3 / g, more preferably 170 to 325 cm 3 / g, most preferably 190 to 300 cm 3 / g.

[0102] The complex viscosity η of the first copolymer (A) at a frequency of 100 rad / s 100 rad / s Preferably, the pressure is 750 to 950 Pa·s, more preferably 800 to 900 Pa·s, and most preferably 820 to 880 Pa·s.

[0103] The first copolymer (A) can be polymerized in a sequential multistage polymerization process (i.e., a polymerization process in which two or more polymerization reactors are connected in series). Preferably, in a sequential multistage polymerization process, two or more, more preferably three or more (e.g., three or four) polymerization reactors are connected in series. The term "polymerization reactor" should indicate the occurrence of the main polymerization reaction. Therefore, in the case where the process consists of four polymerization reactors, this definition does not exclude the option of including, for example, a prepolymerization step in a prepolymerization reactor.

[0104] When the first copolymer (A) is a multiphase propylene copolymer, the matrix phase of the multiphase propylene copolymer is polymerized in a first polymerization reactor for producing a unimodal matrix phase; or in a first polymerization reactor and a second polymerization reactor for producing a multimodal matrix phase.

[0105] The elastomeric phase of the multiphase propylene copolymer is preferably polymerized in one or two subsequent polymerization reactors in the presence of the matrix phase to produce a unimodal or multimodal elastomeric phase.

[0106] Preferably, the polymerization reactor is selected from slurry-phase reactors, such as loop reactors and / or gas-phase reactors, such as fluidized bed reactors, and more preferably from loop reactors and fluidized bed reactors.

[0107] The preferred sequential multi-stage polymerization process is the "loop-gas phase" process, such as that developed by Borealis A / S in Denmark (known as the BORSTAR® technology), as described in patent documents such as EP 0 887 379, WO 92 / 12182, WO 2004 / 000899, WO 2004 / 111095, WO 99 / 24478, WO 99 / 24479 or WO 00 / 68315.

[0108] Another suitable slurry-gas phase process is LyondellBasell's Spheripol® process.

[0109] Suitable sequential polymerization processes for polymerizing the first copolymer (A) (preferably a multiphase propylene copolymer) are disclosed, for example, in EP 1 681 315 A1 or WO 2013 / 092620A1.

[0110] The first copolymer (A) (preferably a multiphase propylene copolymer) can be polymerized in the presence of a Ziegler-Natta catalyst or a single active site catalyst.

[0111] Suitable Ziegler-Natta catalysts are disclosed, for example, in US 5,234,879, WO 92 / 19653, WO 92 / 19658, WO99 / 33843, WO 03 / 000754, WO 03 / 000757, WO 2013 / 092620A1 or WO 2015 / 091839.

[0112] Suitable single-active-site catalysts are disclosed, for example, in WO 2006 / 097497, WO 2011 / 076780 or WO 2013 / 007650.

[0113] The first copolymer (A) can preferably be subjected to a viscosity-reducing cracking step as described in WO 2013 / 092620A1.

[0114] In one embodiment, the first copolymer (A) comprises an α-nucleating agent. The α-nucleating agent is generally not limited.

[0115] Preferably, the α-nucleating agent is selected from soluble α-nucleating agents and polymeric α-nucleating agents.

[0116] α-nucleating agents are preferably selected from the following:

[0117] (i) Dibenzyl sorbitol (e.g., 1,3:2,4-dibenzyl sorbitol) and C1-C8-alkyl-substituted dibenzyl sorbitol derivatives, such as methyl dibenzyl sorbitol, ethyl dibenzyl sorbitol or dimethyl dibenzyl sorbitol (e.g., 1,3:2,4-di(methyl benzyl)sorbitol), or substituted nonanol derivatives, such as 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonanol;

[0118] (ii) Vinylcycloalkane polymers and vinylalkane polymers (discussed in more detail below); and

[0119] (iii) Their mixture.

[0120] The α-nucleating agent is preferably selected from the following: dibenzyl sorbitol (e.g., 1,3:2,4-dibenzyl sorbitol), dibenzyl sorbitol derivatives, preferably dimethyl dibenzyl sorbitol (e.g., 1,3:2,4-di(methylbenzyl)sorbitol), or substituted nonanol derivatives, such as 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonanol, vinyl cycloalkane polymers, vinyl alkane polymers, and mixtures thereof.

[0121] Vinylcycloalkane polymers, such as vinylcyclohexane (VCH) polymers, are particularly preferred. Such polymers can be added, for example, using Borealis nucleation technology (BNT).

[0122] The α-nucleating agent can be added to the first copolymer (A) either as a separate raw material or as a mixture with the carrier polymer (i.e., a so-called masterbatch). Therefore, the amount of the carrier polymer in the masterbatch is included in the amount of the α-nucleating agent.

[0123] Preferably, in this embodiment, the first copolymer (A) contains 0.00001 to 5.00 wt%, more preferably 0.0001 to 2.50 wt% of an α-nucleating agent.

[0124] The amount of pure α-nucleating agent in the first copolymer (A) (carrier polymer excluding optional masterbatch) is preferably 0.01 to 2000 ppm, more preferably 0.1 to 1000 ppm.

[0125] In another embodiment, the first copolymer (A) does not contain, i.e., does not contain, an α-nucleating agent.

[0126] Multiphase propylene copolymer resins suitable as the first copolymer (A) are also commercially available. These resins typically already contain a stabilizer package. Therefore, when using a commercially available resin as the first copolymer (A), the addition of the additives described above may need to be adjusted based on the available additives.

[0127] When using a commercially available first copolymer (A), the above properties can be measured using common measurement methods or verified using technical documents provided by the supplier.

[0128] Second copolymer (B)

[0129] The second copolymer (B) is a copolymer of propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms.

[0130] The comonomer unit is selected from ethylene and α-olefins having 4 to 12 carbon atoms, such as ethylene, 1-butene, 1-hexene and 1-octene, preferably selected from ethylene, 1-butene and 1-hexene, and most preferably ethylene.

[0131] In a preferred embodiment, the second copolymer (B) is a copolymer of propylene and ethylene.

[0132] Based on the total weight of the second copolymer (B), the second copolymer (B) was quantitatively determined by crystallization extraction (CRYSTEX). 13 The total monomer content (preferably ethylene content) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is 4.0 to 10.0 wt%, preferably 5.0 to 9.5 wt%, and more preferably 6.0 to 9.0 wt%.

[0133] Preferably, based on the total weight of the first copolymer (A), the second copolymer (B) is produced by a quantitative method. 13 The total propylene content determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is 90.0 to 96.0 wt%, preferably 90.5 to 95.0 wt%, and most preferably 91.0 to 94.0 wt%.

[0134] The second copolymer (B) is preferably composed of propylene and ethylene. Therefore, preferably, the total ethylene content and the total propylene content account for 100 wt% of the propylene and ethylene copolymer.

[0135] Preferably, the total monomer content (preferably total ethylene content) of the second copolymer (B) is lower than that of the first copolymer (A).

[0136] Furthermore, the melt flow rate (MFR2) of the second copolymer (B), as determined according to ISO 1133 at 230°C and 2.16 kg, is at least 2.0 g / 10 min, for example 2.0 to 2000 g / 10 min, preferably 3.0 to 500 g / 10 min, even more preferably 4.0 to 100 g / 10 min, and most preferably 5.0 to 30.0 g / 10 min.

[0137] Preferably, the second copolymer (B) is a multiphase propylene copolymer.

[0138] The multiphase propylene copolymer has a matrix phase and an elastomer phase dispersed in the matrix phase.

[0139] The matrix phase is preferably a random copolymer of propylene and ethylene.

[0140] In the second copolymer (B) (e.g., a multiphase propylene copolymer), the matrix phase and the elastomer phase are often not precisely separable from each other. Several known methods exist for characterizing the matrix and elastomer phases of multiphase propylene copolymers. One method is crystallization extraction (CRYSTEX), as described above for the first copolymer (A).

[0141] Based on the total weight of the second copolymer (B), the content of the crystal fraction (CF) of the second copolymer (B) as determined by crystallization extraction (CRYSTEX) is preferably 75.0 to 88.0 wt%, more preferably 77.5 to 86.5 wt%, and most preferably 80.0 to 85.0 wt%.

[0142] Based on the total amount of monomer units in the crystalline fraction (CF), the crystalline fraction (CF) is quantified by crystallization extraction (CRYSTEX). 13 The comonomer content (preferably ethylene content (C2(CF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is preferably 1.0 to 15.0 wt%, more preferably 2.0 to 10.0 wt%, and most preferably 3.0 to 8.5 wt%.

[0143] Furthermore, the intrinsic viscosity (iV(CF)) of the crystalline fraction (CF) as determined according to ISO 1628-3 is preferably 165 to 290 cm⁻¹. 3 / g, more preferably 175 to 265 cm 3 / g, most preferably 190 to 240 cm 3 / g.

[0144] Based on the total weight of the second copolymer (B), the soluble fraction (SF) content of the second copolymer (B) determined by crystallization extraction (CRYSTEX) is 12.0 to 25.0 wt%, preferably 13.5 to 22.5 wt%, and most preferably 15.0 to 20.0 wt%.

[0145] Based on the total amount of monomer units in the soluble fraction (SF), the soluble fraction (SF) is obtained by quantitative analysis. 13The comonomer content (preferably ethylene content (C2(SF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is preferably 15.0 to 35.0 wt%, more preferably 17.5 to 32.5 wt%, and most preferably 20.0 to 30.0 wt%.

[0146] Furthermore, the intrinsic viscosity (iV(SF)) of the soluble fraction (SF) as determined according to ISO 1628-3 is preferably 90 to 190 cm⁻¹. 3 / g, more preferably 100 to 180 cm 3 / g, with an optimal value of 115 to 170 cm 3 / g.

[0147] Preferably, the crystalline fraction (CF) and the soluble fraction (SF) comprise 100% of the second copolymer (B).

[0148] The soluble fraction (SF) content of the second copolymer (B) is lower than that of the first copolymer (A).

[0149] The flexural modulus of the second copolymer (B), as determined according to ISO 178 Method A, is preferably greater than 470 MPa, for example from 475 MPa to 800 MPa, more preferably from 500 MPa to 750 MPa, and most preferably from 550 MPa to 700 MPa.

[0150] Furthermore, the Charpy notched impact strength of the second copolymer (B) at 23°C, as determined according to ISO 179-1 / 1eA, is preferably 4.0 to 15.0 kJ / m. 2 More preferably 5.0 to 13.0 kJ / m 2 The optimal value is 6.0 to 11.5 kJ / m³. 2 .

[0151] Furthermore, the melting temperature Tm of the second copolymer (B), as determined by DSC analysis according to ISO 11357 / Part 3 / Method C2, is preferably 130 to 150°C, more preferably 135 to 147°C, and most preferably 140 to 145°C.

[0152] Furthermore, the crystallization temperature Tc of the second copolymer (B), as determined by DSC analysis according to ISO 11357 / Part 3 / Method C2, is preferably 80 to 120°C, more preferably 85 to 115°C, and most preferably 90 to 110°C.

[0153] The difference between the melting temperature and the crystallization temperature, Tm-Tc, is preferably 20 to 70°C, more preferably 25 to 60°C, and most preferably 30 to 55°C.

[0154] The total intrinsic viscosity of the second copolymer (B), as determined according to ISO 1628-3, is preferably 100 to 250 cm⁻¹. 3 / g, more preferably 125 to 235 cm 3 / g, most preferably 150 to 220 cm 3 / g.

[0155] The complex viscosity η of the second copolymer (B) at a frequency of 100 rad / s 100 rad / s Preferably, it is 500 to 700 Pa·s, more preferably 550 to 650 Pa·s, and most preferably 570 to 630 Pa·s.

[0156] The second copolymer (B) can be polymerized in a sequential multistage polymerization process (i.e., a polymerization process in which two or more polymerization reactors are connected in series). Preferably, in a sequential multistage polymerization process, two or more, more preferably three or more (e.g., three or four) polymerization reactors are connected in series. The term "polymerization reactor" should indicate the occurrence of the main polymerization reaction. Therefore, in the case where the process consists of four polymerization reactors, this definition does not exclude the option of including a prepolymerization step, for example, in a prepolymerization reactor.

[0157] When the second copolymer (B) is a multiphase propylene copolymer, the matrix phase of the multiphase propylene copolymer can be polymerized in a first polymerization reactor used to produce a unimodal matrix phase, or in a first polymerization reactor and a second polymerization reactor used to produce a multimodal matrix phase.

[0158] The elastomeric phase of the multiphase propylene copolymer is preferably polymerized in one or two subsequent polymerization reactors in the presence of the matrix phase to produce a unimodal or multimodal elastomeric phase.

[0159] Preferably, the polymerization reactor is selected from slurry-phase reactors, such as loop reactors and / or gas-phase reactors, such as fluidized bed reactors, and more preferably from loop reactors and fluidized bed reactors.

[0160] The preferred sequential multi-stage polymerization process is the "loop-gas phase" process, such as that developed by Borealis A / S in Denmark (known as the BORSTAR® technology), as described in patent documents such as EP 0 887 379, WO 92 / 12182, WO 2004 / 000899, WO 2004 / 111095, WO 99 / 24478, WO 99 / 24479 or WO 00 / 68315.

[0161] Another suitable slurry-gas phase process is LyondellBasell's Spheripol® process.

[0162] Suitable sequential polymerization processes for polymerizing the second copolymer (B) (preferably a multiphase propylene copolymer) are disclosed, for example, in WO2015 / 117948.

[0163] The second copolymer (B) (preferably a multiphase propylene copolymer) can be polymerized in the presence of a Ziegler-Natta catalyst.

[0164] Suitable Ziegler-Natta catalysts are disclosed, for example, in WO 2015 / 117948.

[0165] The second copolymer (B) can preferably be subjected to a viscosity-reducing cracking step as described in WO2013 / 092620A1.

[0166] Multiphase propylene copolymer resins suitable as the second copolymer (B) are also commercially available. These resins typically already contain a stabilizer package. Therefore, when using commercially available resins as the second copolymer (B), the addition of additives as described above may need to be adjusted based on the available additives.

[0167] When using a commercially available second copolymer (B), the above properties can be measured using common measurement methods or verified using technical documentation provided by the supplier.

[0168] Carbon black (C)

[0169] Any conductive carbon black can be used. Typically, the carbon black will be a specialty carbon black or a P-type carbon black. Non-limiting examples of suitable carbon blacks include furnace black.

[0170] The nitrogen adsorption surface area (NSA) of carbon black, as determined by ASTM D6556-19, can range from 5 to 400 m². 2 / g, for example 10 to 300 m 2 / g, for example 30 to 200 m 2 / g.

[0171] In addition, carbon black can have one or more of the following properties:

[0172] • The primary particle size is at least 5 nm, for example 5 to 30 nm, preferably 10 to 20 nm, which is defined as the average particle size according to ASTM D3849-14;

[0173] • The iodine adsorption value, as determined according to ASTM D-1510-19, is at least 10 mg / g, for example, 10 to 300 mg / g, preferably 30 to 250 mg / g, more preferably 30 to 200 mg / g, for example, 30 to 60 mg / g or 80 to 140 mg / g; and / or

[0174] • The oil absorption value (OAN) determined according to ASTM D2414-19 is at least 30 ml / 100g, for example 30 to 140 ml / 100g, preferably 50 to 130 ml / 100g, more preferably 70 to 130 ml / 100g.

[0175] These properties are typically provided in the technical documentation of suppliers of commercially available carbon black grades.

[0176] A suitable group of furnace blacks has a primary particle size of less than 28 nm. In particular, a particularly suitable furnace black in this class has an iodine adsorption value of 60 to 300 mg / g. Furthermore, suitablely, the oil adsorption value (of this class) is 50 to 225 ml / 100g, for example, 50 to 200 ml / 100g.

[0177] Other suitable carbon blacks can be prepared by any other process or can be further processed. The characteristic of suitable carbon blacks for semiconductor cable layers is their cleanliness. Therefore, suitable carbon blacks should have an ash content of less than 0.2 wt% as measured by ASTM D1506, a residue of less than 30 ppm on a 325-mesh sieve as measured by ASTM D1514, and a total sulfur content of less than 3 wt%, preferably less than 1 wt%, as measured by ASTM D1619.

[0178] Furnace black is the recognized term for a well-known type of carbon black produced in a furnace reactor. Examples of carbon black, its preparation processes, and reactors can be found, for example, in Cabot's EP629222, US4,391,789, US3,922,335, and US3,401,020. Examples of commercial furnace black grades include N115, N351, N293, N220, and N550. To further improve the suitability of such carbon blacks for use in semiconductor compounds, modification of these commercial carbon blacks in terms of, for example, cleanliness, granulation properties, and surface area is advantageous. Furnace black is generally distinguished from acetylene black.

[0179] Functionalized polyolefins (D)

[0180] In this document, "functionalization with monocarboxylic or polycarboxylic acid compounds or derivatives thereof," or simply "functionalization," generally refers to the functionalization of a polymer with a carbonyl-containing group derived from the monocarboxylic or polycarboxylic acid group or its derivative. The carbonyl-containing compound used for functionalization is typically unsaturated. Such a compound preferably contains at least one olefinic unsaturated bond and at least one carbonyl group. This carbonyl-containing group can be introduced into the polymer by grafting a compound with the carbonyl-containing group onto the polymer, or by copolymerizing the monomer with a comonomer containing such a carbonyl-containing group.

[0181] In this document, the functionalized carbonyl compounds of the functionalized polyolefin (D) should be understood not to represent any polar comonomers, such as acrylate, methacrylate or acetate comonomers.

[0182] The functionalized polyolefin (D) is different from the first copolymer (A) and the second copolymer (B).

[0183] The functionalized polyolefins (D) suitable for this invention are well known and commercially available, or can be produced according to known processes described in chemical literature.

[0184] Preferably, the polycarboxylic acid compound used for functionalization is an unsaturated dicarboxylic acid or a derivative thereof. More preferably, the carbonyl-containing compound used for functionalization is a derivative of an unsaturated monocarboxylic acid or polycarboxylic acid compound, and even more preferably a derivative of an unsaturated dicarboxylic acid. Preferably, the carbonyl-containing compound used for functionalization is an anhydride of a monocarboxylic acid or polycarboxylic acid, also referred to as "anhydride" or "anhydride". The anhydride can be linear or cyclic.

[0185] Preferably, the functionalized polyolefin (D) is an anhydride-functionalized polyolefin, more preferably a maleic anhydride (MAH)-functionalized polyolefin (D). Preferably, the functionalized polyolefin (D) can be obtained by grafting maleic anhydride onto the polyolefin (also referred to herein as MAH-grafted polyolefin or MAH-g-polyolefin).

[0186] Preferably, the polyolefin used for the functionalized polyolefin (D) is functionalized polypropylene or polyethylene. Both of these types of polyolefins are well known in the art.

[0187] In the case where the functionalized polyolefin (D) is functionalized polyethylene, it is preferably selected from: polyethylene produced in a low-pressure process using a coordination catalyst, or polyethylene produced in a high-pressure (HP) polymerization process and carrying the carbonyl-containing functional group. Both meanings are well known in the art.

[0188] The MFR (190°C, 2.16 kg) of the functionalized polyethylene (D) is preferably greater than 0.05 g / 10 min, preferably 0.1 to 200 g / 20 min, more preferably 0.80 to 100 g / 10 min, and even more preferably 1.0 to 50.0 g / 10 min.

[0189] When the functionalized polyolefin (D) is a functionalized polyethylene produced by a low-pressure process using a coordination catalyst, it is preferably selected from copolymers of ethylene and one or more comonomers (preferably α-olefins). The density of such polyethylene copolymers is preferably 850 to 950 kg / m³. 3 Preferably 900 to 945 kg / m 3Preferably 910 to 940 kg / m 3 Such functionalized polyethylene copolymers are preferably functionalized linear low-density polyethylene copolymers (LLDPEs) with a density preferably between 915 and 930 kg / m³. 3 The preferred LLDPE for functionalized polyolefins (D) is MAH-functionalized LLDPE, with MAH-g-LLDPE being more preferred.

[0190] In the case where the functionalized polyolefin (C) is functionalized polyethylene produced by the HP process, the polyethylene is preferably produced by free radical polymerization in the HP process in the presence of an initiator. The HP reactor can be, for example, a well-known tubular reactor or a batch reactor, or a combination thereof, preferably a tubular reactor. High-pressure (HP) polymerization and the adjustment of process conditions according to the desired end application to further customize other properties of the polyolefin are well known and described in the literature and can be readily used by those skilled in the art. Suitable polymerization temperatures range up to 400°C, preferably 80 to 350°C; pressures start from 70 MPa, preferably 100 to 400 MPa, more preferably 100 to 350 MPa. Pressure can be measured at least after the compression stage and / or after the tubular reactor. Temperature can be measured at several points throughout all steps. Such functionalized polyethylene produced in the HP process is preferably low-density polyethylene (LDPE), which is functionalized and has a density preferably of 900 to 950 kg / m³. 3 More preferably 910 to 940 kg / m 3 The optimal value is 915 to 930 kg / m³. 3More preferably, the functionalized LDPE polymer is selected from LDPE homopolymers or LDPE copolymers of ethylene with one or more comonomers (also referred to herein as functionalized polar LDPE copolymers) having the carbonyl group. Suitable comonomers for the functionalized LDPE copolymers are selected from olefins (preferably α-olefins) or polar comonomers or any mixtures thereof. As mentioned above, such polar comonomers may be additionally present and are different from the carbonyl-containing compounds used for functionalization. Functionalized ethylene LDPE copolymers having polar comonomers may optionally contain other comonomers, such as α-olefins. Polar comonomers are preferably selected from comonomers containing hydroxyl, alkoxy, carbonyl, carboxyl, ether, or ester groups or mixtures thereof; more preferably from comonomers containing carboxyl and / or ester groups; and even more preferably, polar comonomers are selected from acrylates, methacrylates, acrylic acid, methacrylic acid, or acetates, or any mixtures thereof. The polar comonomers used in the functionalized polar LDPE copolymers are more preferably selected from alkyl acrylates, alkyl methacrylates, acrylic acid, methacrylic acid, or vinyl acetate, or mixtures thereof. It is also preferred that the comonomers are selected from C1- to C6-alkyl acrylates, C1- to C6-alkyl methacrylates, acrylic acid, methacrylic acid, and vinyl acetate, more preferably from C1- to C4-alkyl acrylates (e.g., methyl acrylate, ethyl acrylate, propyl acrylate, or butyl acrylate), or vinyl acetate, or any mixture thereof. Based on the total amount of the composition, the amount of polar comonomers in the functionalized LDPE copolymer is preferably 5 to 50 wt%, more preferably up to 30 wt%, and most preferably up to 25 wt%. The functionalized LDPE homopolymer or LDPE copolymer is preferably selected from MAH-functionalized LDPE homopolymer, MAH-functionalized LDPE copolymer (preferably selected from MAH-functionalized ethylene methyl acrylate (EMA), MAH-functionalized ethylene ethyl acrylate (EEA), MAH-functionalized ethylene butyl acrylate (EBA), or MAH-functionalized ethylene vinyl acetate (EVA)), more preferably selected from MAH-g-LDPE homopolymer or MAH-g-LDPE copolymer, and even more preferably selected from MAH-g-EMA, MAH-g-EEA, MAH-g-EBA, or MAH-g-EVA.

[0191] In the case where the functionalized polyolefin (D) is functionalized polypropylene, it is preferably selected from propylene homopolymers, propylene random copolymers or propylene multiphase copolymers, which have the same meaning and properties as given in the general description for the first copolymer (A) and the second copolymer (B) above, and have the carbonyl group.

[0192] Preferred polypropylene is propylene homopolymer or propylene random copolymer.

[0193] According to a preferred embodiment of the polymer composition, the maleic anhydride-functionalized (preferably grafted) polyolefin is maleic anhydride-functionalized (preferably grafted) polypropylene (MAH-g-PP) or maleic anhydride-functionalized (preferably grafted) polyethylene (MAH-g-PE).

[0194] The preferred polyolefin (D) for use is functionalized polypropylene as defined above. Such polypropylene (PP) for use as functionalized polyolefin (D) is preferably maleic anhydride-functionalized polypropylene, more preferably MAH-g-PP.

[0195] The functionalized polyolefin (D), more preferably MAH-functionalized polypropylene, and even more preferably MAH-g-PP, has a melt flow rate MFR2 (230°C, 2.16 kg) of 0.5 to 500 g / 10 min, preferably 1.0 to 500 g / 10 min.

[0196] Products

[0197] In another aspect, the present invention relates to an article comprising a semiconductor composition as described above or as described below.

[0198] Preferably, the article is a cable having a semiconductor layer, more preferably an inner and / or outer semiconductor layer, the semiconductor layer comprising, or preferably composed of, a semiconductor composition as described above or below.

[0199] Based on the total weight of the semiconductor layer, the semiconductor layer, more preferably the inner and / or outer semiconductor layer, contains 90 to 100 wt%, more preferably 95 to 100 wt%, and even more preferably 99 to 100 wt% of the semiconductor composition as described above or as described below, and most preferably consists of the semiconductor composition.

[0200] The cable preferably includes a conductor surrounded by at least one semiconductor layer, the semiconductor layer comprising a semiconductor composition as described above or below, preferably composed of a semiconductor composition as described above or below.

[0201] In this document, the term "conductor" as used above and below refers to one or more wires. These wires can be used for any purpose, such as as optical fibers, communication lines, or electrical wires. Furthermore, a cable may include more than one such conductor. Preferably, the conductor is an electrical conductor and comprises one or more metallic wires. The cable is preferably a power cable. A power cable is defined as a cable that transmits energy and can operate at any voltage, typically above 1 kV. The voltage applied to a power cable can be alternating current (AC), direct current (DC), or transient (pulse). The polymer compositions of the present invention are particularly suitable for power cables, especially for power cables operating at voltages from 6 kV to 36 kV (medium voltage (MV) cables). These terms have well-known meanings and indicate the operating class of such cables.

[0202] In one embodiment, the cable includes a conductor surrounded by at least an inner semiconductor layer, an insulating layer, and an outer semiconductor layer in this order, wherein at least the inner semiconductor layer or the inner and outer semiconductor layers comprise a semiconductor composition as described above or below, preferably composed of a semiconductor composition as described above or below.

[0203] Preferably, the cable is an MV power cable.

[0204] Furthermore, the outer semiconductor layer can be peelable (removable) or bonded (non-removable), preferably bonded, terms with well-known meanings.

[0205] As is well known, cables may optionally include other layers, such as layers surrounding an insulation layer, or layers surrounding an outer semiconductor layer (if present), such as a shielding layer, a sheathing layer, other protective layers, or any combination thereof.

[0206] The insulation layer of the cable (if present) preferably comprises a polyolefin composition, more preferably a polyolefin composition, such as a polyethylene composition, such as a cross-linked polyethylene composition or a non-cross-linked polyethylene composition, or a polypropylene composition.

[0207] Preferably, the insulation layer of the cable (if present) preferably comprises a thermoplastic polyolefin composition, more preferably a thermoplastic polyolefin composition, such as a non-crosslinked polyethylene composition or a non-crosslinked polypropylene composition.

[0208] Particularly preferably, the insulation layer of the cable (if present) preferably comprises a non-crosslinked polypropylene composition, more preferably composed of a non-crosslinked polypropylene composition.

[0209] The non-crosslinked polypropylene composition preferably contains a multiphase propylene copolymer as the main polymer component.

[0210] Particularly preferably, the non-crosslinked polypropylene composition comprises a first copolymer (A) as described above or below as the main polymer component.

[0211] The cable has a semiconductor layer, preferably an inner semiconductor layer or an inner and outer semiconductor layer, wherein the semiconductor layer comprises the semiconductor composition according to the invention as described above. The cable exhibits good electrical performance, characterized by high Weibull α and high Weibull β values ​​when performing Weibull analysis on a series of AC electrical breakdown results.

[0212] Furthermore, according to CENELEC HD 605 5.4.15.3.4, when measuring a 6 / 10kV cable on a 10kV cable, the Weibull α value of the cable is preferably at least 20.0kV / mm, more preferably at least 40kV / mm, even more preferably at least 45kV / mm, even more preferably at least 46.0kV / mm, even more preferably at least 47.0kV / mm, and most preferably at least 47.0kV / mm.

[0213] According to CENELEC HD 605 5.4.15.3.4, when measuring 6 / 10kV cables on 10kV cables, the upper limit of the Weibull α value is generally no more than 80.0kV / mm.

[0214] Furthermore, when measuring a 6 / 10kV cable on a 10kV cable according to CENELEC HD 605 5.4.15.3.4, the Weibull β value of the cable is preferably at least 7.5, more preferably at least 8.0, even more preferably at least 8.5, even more preferably at least 9.0, and most preferably at least 10.0.

[0215] According to CENELEC HD 605 5.4.15.3.4, when measuring 6 / 10kV cables on 10kV cables, the upper limit of the Weibull β value is generally no more than 250.0.

[0216] Therefore, the semiconductor layer comprising the semiconductor composition according to the present invention can be used in medium-voltage and high-voltage cables.

[0217] The inner semiconductor layer comprising the semiconductor composition described above or below has a volume resistivity preferably not greater than 15 Ohm·cm, more preferably not greater than 13 Ohm·cm, and most preferably not greater than 12 Ohm·cm when measured at 20°C on a 10kV cable.

[0218] When measuring a 10kV cable at 20°C, the lower limit is typically at least 6 Ohm·cm, preferably at least 7 Ohm·cm.

[0219] Furthermore, when measuring a 10kV cable at 90°C, the volume resistivity of the inner semiconductor layer containing the semiconductor composition described above or below is preferably not greater than 55 Ohm·cm, more preferably not greater than 53 Ohm·cm, and most preferably not greater than 50 Ohm·cm.

[0220] When measuring a 10kV cable at 90°C, the lower limit is typically at least 20 Ohm·cm, preferably at least 25 Ohm·cm.

[0221] When measuring a 10kV cable at 20°C, the volume resistivity of the outer semiconductor layer containing the semiconductor composition described above or below is preferably not greater than 15 Ohm·cm, more preferably not greater than 13 Ohm·cm, and most preferably not greater than 12 Ohm·cm.

[0222] When measuring a 10kV cable at 20°C, the lower limit is typically at least 6 Ohm·cm, preferably at least 7 Ohm·cm.

[0223] Furthermore, when measuring a 10kV cable at 90°C, the outer semiconductor layer containing the semiconductor composition described above or below preferably has a volume resistivity of no more than 55 Ohm·cm, more preferably no more than 53 Ohm·cm, and most preferably no more than 50 Ohm·cm.

[0224] When measuring a 10kV cable at 90°C, the lower limit is typically at least 20 Ohm·cm, preferably at least 25 Ohm·cm.

[0225] In another aspect, the present invention relates to the use of semiconductor compositions as described above or below as inner and / or outer semiconductor layers of medium-voltage cables.

[0226] Preferably, the semiconductor composition described above or below is used as the inner and / or outer semiconductor layer to improve the average breakdown strength of the medium-voltage cable.

[0227] Benefits of the present invention

[0228] The semiconductor composition contains a fairly low amount of carbon black, yet still exhibits a good balance between electrical conductivity and mechanical properties.

[0229] Furthermore, this semiconductor composition exhibits excellent extrusion properties. The composition does not stick together during extrusion. Additionally, it is not easily brittle when extruded into strips or cable layers.

[0230] The strip of the semiconductor composition also exhibits excellent surface smoothness.

[0231] Cables comprising an inner semiconductor layer and an optional outer semiconductor layer (comprising the semiconductor composition of the present invention) unexpectedly exhibit good electrical performance in terms of average AC breakdown strength, Weibull α value, and Weibull β value.

[0232] When the polymer composition of the insulating layer is changed to a propylene-based polymer instead of an ethylene-based composition, the electrical properties can be further improved, particularly by a more uniform distribution of electrical breakdown strength, resulting in a higher Weibull β value. This performance is believed to be due to increased adhesion between the semiconductor layer and the insulating layer caused by the similar polymer composition.

[0233] Furthermore, cables containing an inner semiconductor layer and an optional outer semiconductor layer (containing the semiconductor composition of the present invention) exhibit good volume resistivity, especially at high temperatures such as 90°C, which is considered the operating temperature of the cable.

[0234] The reason for this is that the first copolymer (A), which is the main polymer composition, has a relatively high melting temperature, so that the first copolymer has not yet melted at the operating temperature. Therefore, only the difference in thermal expansion between the carbon black and the polymer matrix leads to an increase in volume resistivity.

[0235] Example

[0236] Unless otherwise specified, the following terminology and measurement methods apply to the general description of the invention above and the following embodiments.

[0237] 1. Measurement Method

[0238] A) Melt flow rate (MFR2)

[0239] Melt flow rate is the amount of polymer (in grams) extruded within 10 minutes using a test instrument standardized according to ISO 1133 at a specific temperature and load.

[0240] The melt flow rate (MFR2) of propylene polymers was measured according to ISO 1133 at 230°C and a load of 2.16 kg.

[0241] The melt flow rate (MFR5) of the propylene polymer and semiconductor composition was measured according to ISO 1133 at 230°C and a load of 5.0 kg.

[0242] Melt Flow Rate (MFR) of Propylene Polymers and Semiconductor Compositions 10 Measured according to ISO 1133 at 230°C and a load of 10 kg.

[0243] Melt Flow Rate (MFR) of Propylene Polymers and Semiconductor Compositions 21Measured according to ISO 1133 at 230°C and a load of 21.6 kg.

[0244] The melt flow rate (MFR2) of ethylene-based polymers was measured according to ISO 1133 at 190°C and a load of 2.16 kg.

[0245] b) density

[0246] Density was determined according to ISO 1183-1:2004 Method A on compression-molded specimens prepared according to EN ISO 1872-2 (February 2007), and the unit is g / cm³. 3 .

[0247] c) Comonomer content

[0248] Quantitative analysis of comonomer content in poly(propylene-co-ethylene) copolymers

[0249] against 1 H and 13 C. Using a Bruker Avance NEO 400 NMR spectrometer, quantitative analysis of the solution state was recorded at 400.15 MHz and 100.62 MHz, respectively. 13 C{ 1 ¹H NMR spectra. All spectra were obtained using ¹H NMR spectroscopy. 13 A C-optimized 10mm extended temperature probe was used for recording at 125°C, with nitrogen used for all pneumatic devices. Approximately 200 mg of material and chromium acetylacetone (Cr(acac)3) were dissolved together in 3 mL of 1,2-tetrachloroethane-d2 (TCE-d2) to obtain a 60 mM relaxant solution in the solvent {8}, with approximately 3 mg of BHT (2,6-di-tert-butyl-4-methylphenol, CAS 128-37-0) added. To ensure solution homogeneity, the NMR tubes were further heated in a rotary oven for at least 1 hour after initial sample preparation in a heating block. The tubes were rotated at 10 Hz after the magnet was inserted. This setup was chosen primarily to obtain the high resolution and quantification required for accurate ethylene content quantification. Standard single-pulse excitation without NOE was used, with an optimized apex cone angle, a 1-second cycle delay, and a dual-level WALTZ16 decoupling scheme {3,4}. A total of 6144 (6 k) transient signals were acquired for each spectrum.

[0250] Quantitative analysis was performed using a dedicated computer program. 13 C{ 1The ¹H NMR spectra were processed, integrated, and the relevant quantitative properties were determined based on the integration. Chemical shifts of the solvent were used, with all chemical shifts indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm. This method allows for comparable references even in the absence of this structural unit. Characteristic signals corresponding to ethylene incorporation were observed {7}.

[0251] Using the method of Wang et al. {6}, by... 13 C{ 1 The integration of multiple signals across the entire spectral region of the H spectrum is used to quantify the comonomer fraction. This method was chosen for its robustness and ability to account for regional defects when necessary. Slight adjustments were made to the integration region to increase its applicability across the entire range of comonomer content encountered.

[0252] For systems where only isolated ethylene can be observed in the PPEPP sequence, the method of Wang et al. was modified to reduce the influence of non-zero integrals from sites that are known to be absent. This method reduces the overestimation of ethylene content in such systems by reducing the number of sites used to determine absolute ethylene content to the following:

[0253] E = 0.5 (Sββ + Sβγ + Sβδ + 0.5(Sαβ + Sαγ))

[0254] By using this set of sites, the corresponding integral equation becomes:

[0255] E = 0.5 (I H +I G + 0.5(I C + I D ))

[0256] The same notation as in the article by Wang et al. {6} is used. The equation for absolute propylene content remains unchanged.

[0257] The molar percentage of comonomer incorporated is calculated from the mole fraction:

[0258]

[0259] The weight percentage of comonomer incorporated is calculated from the mole fraction:

[0260]

[0261] References:

[0262] 1)Busico, V., Cipullo, R., Prog. Polym. Sci. 26 (2001) 443.

[0263] 2)Busico, V., Cipullo, R., Monaco, G., Vacatello, M., Segre, AL,Macromolecules 30 (1997) 6251.

[0264] 3)Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A.,Baugh, D. Winniford, B., J. Mag. Reason. 187 (2007) 225.

[0265] 4)Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn,J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128.

[0266] 5)Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev.2000, 100, 1253.

[0267] 6)Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157.

[0268] 7)Cheng, HN, Macromolecules 17 (1984), 1950.

[0269] 8)Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009),475.

[0270] 9)Kakugo, M., Naito, Y., Mizunuma, K., Miyatake, T. Macromolecules 15(1982) 1150.

[0271] 10) Randall, J. Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29,201.

[0272] 11) Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev.2000, 100, 1253.

[0273] d) Differential scanning calorimetry (DSC) analysis, melting temperature (Tm) and crystallization temperature (Tc):

[0274] Samples of 5 to 7 mg were measured using a TA Instrument Q2000 differential scanning calorimeter (DSC). The DSC was operated according to ISO 11357 / Part 3 / Method C2, using a heating / cooling / heating cycle, a scan rate of 10 °C / min, and a temperature range of -30 °C to +225 °C.

[0275] The crystallization temperature and heat of crystallization (Hc) are determined by the cooling step, while the melting temperature and heat of fusion (Hf) are determined by the second heating step.

[0276] When a sample displays more than two melting temperatures and / or crystallization temperatures, only the primary melting temperature (at the highest Hf) and the primary crystallization temperature (at the highest Hc) are shown in the corresponding table. The difference between the primary melting temperature and the primary crystallization temperature (Tm-Tc) is given.

[0277] e) Crystallization extraction method (CRYSTEX)

[0278] Note: Crystallization extraction (CRYSTEX) analyzes the polymer fraction of each component; non-polymer fractions (such as any filler or particulate pigment) are not included in the presented CRYSTEX data.

[0279] Determination of crystalline and soluble fractions and their respective characteristics (iV and ethylene content)

[0280] The crystalline fraction (CF) and soluble fraction (SF) of polypropylene (PP) compositions, as well as the comonomer content and intrinsic viscosity of each fraction, were analyzed using the Crystex (crystallization extraction) method. Potential instruments that can be used are the Crystex QC or Crystex 42 (Polymer Char; Valencia, Spain). Detailed information on the technique and method can be found in the literature (Ljiljana Jeremic, Andreas Albrecht, Martina Sandholzer & Markus Gahleitner (2020): Rapid characterization of high-impact ethylene–propylene copolymer composition by crystallization extraction separation: comparability to standard separation methods, International Journal of Polymer Analysis and Characterization, 25:8, 581-596).

[0281] The crystalline and amorphous fractions were separated by temperature cycling: dissolution at 160 °C, crystallization at 40 °C, and redissolution in 1,2,4-trichlorobenzene at 160 °C. Quantitative analysis of SF and CF, as well as determination of ethylene content (C2), were achieved using an integrated infrared detector (IR4); simultaneously, intrinsic viscosity (IV) was determined using an online dual-capillary viscometer.

[0282] The IR4 detector is a multi-wavelength detector that measures CH3 stretching vibrations (center wavelength approximately 2960 cm⁻¹) in two different wavelength bands. -1 ) and CH stretching vibration (2700-3000 cm) -1 The IR absorption of the IR4 detector is used to determine the concentration and ethylene content in ethylene-propylene copolymers. The IR4 detector uses a series of eight known ethylene contents ranging from 2 wt% to 69 wt% (from...). 13 The EP copolymers (measured by C-NMR) were calibrated, with each copolymer having a different concentration ranging from 2 to 13 mg / ml. To simultaneously address both the expected polymer concentrations and ethylene content during Crystex analysis, the following calibration equation was applied:

[0283] (Equation 1)

[0284] (Equation 2)

[0285] The constants a to f in Equation 1 and the constants a to e in Equation 2 were determined using the least squares regression analysis method.

[0286] CH3 / 1000C can be converted to ethylene content (wt%) using the following relationship:

[0287] (Equation 3)

[0288] The amounts of soluble fraction (SF) and crystalline fraction (CF) were correlated by XS calibration with the amounts of "xylene cold-soluble matter" (XCS) and the corresponding "xylene cold-insoluble matter" (XCI) fractions determined according to the ISO 16152 gravimetric method. XS calibration was performed by testing various EP copolymers with XS contents ranging from 2 to 31 wt%. Linear calibration curves were used.

[0289] The intrinsic viscosity (iV) of the parent EP copolymer and its soluble and crystalline fractions was determined using an online dual-capillary viscometer and correlated with the corresponding IV measured in decahydronaphthalene according to the ISO 1628-3 standard method. Calibration was performed using various EP copolymers and PP polymers with iV values ​​ranging from 2 to 4 dL / g. The obtained calibration curves were linear.

[0290] The sample to be analyzed was weighed at a concentration of 10 mg / ml to 20 mg / ml.

[0291] After automatically filling vials with 1,2,4-trichlorobenzene (1,2,4-TCB) containing 250 mg / L 2,6-di-tert-butyl-4-methylphenol (BHT) as an antioxidant, the sample was dissolved at 170°C until complete dissolution was achieved by continuous stirring or gentle shaking. To prevent sample degradation, the polymer solution was covered with a nitrogen atmosphere during the dissolution process.

[0292] For PP compositions containing inorganic fillers, pigments, or any other polymeric substances insoluble in TCB, these must be removed. This can be accomplished by hot filtration before injection.

[0293] A specified volume of polymer solution is injected into a chromatographic column packed with an inert support, where crystallization of the sample and separation of the soluble and crystalline fractions occur. This process is repeated twice. During the first injection, the entire sample is measured at high temperature to determine the IV [dl / g] and C2 [wt%] of the PP composition. During the second injection, the soluble fraction (at low temperature) and the crystalline fraction (at high temperature) during the crystallization cycle are measured (wt% SF, wt% C2, iV).

[0294] f) Intrinsic viscosity (iV)

[0295] Specific viscosity (also known as viscosity number) η 比浓 The intrinsic viscosity iV was measured according to ISO 1628-3 "Determination of viscosity of polymers in dilute solutions using a capillary viscometer".

[0296] The relative viscosities of a 1 mg / ml diluted polymer solution and pure solvent (decahydronaphthalene stabilized with 200 ppm 2,6-bis(1,1-dimethylethyl)-4-methylphenol) were determined in an automated capillary viscometer (Lauda PVS1) equipped with four Ubbelohde capillaries placed in a thermostatic bath containing silicone oil. The bath temperature was maintained at 135°C. The sample was dissolved under continuous stirring until completely dissolved (typically within 90 minutes).

[0297] Measure the outflow time of the polymer solution and the pure solvent multiple times until the difference between three consecutive readings does not exceed 0.2 seconds (standard deviation).

[0298] The relative viscosity of the polymer solution was determined as the ratio of the average eluent times obtained by the polymer solution and the solvent:

[0299] Specific viscosity ( The following formula can be used to calculate:

[0300] In the formula, C is the concentration of the polymer solution at 135℃: , For polymer quality, The volume of the solvent. The density ratio of the solvent at 20℃ and 135℃ ( ).

[0301] The intrinsic viscosity iV was calculated using the Schulz-Blaschke equation based on a single concentration measurement:

[0302] iV=

[0303] In the formula, K is a coefficient that depends on the polymer structure and concentration. To calculate an approximation of IV, K = 0.27 is used.

[0304] g) Flexural modulus

[0305] Flexural modulus was measured on an 80 mm × 10 mm × 4 mm specimen according to ISO 178 Method A (three-point bending test). A test speed of 2 mm / min and a span of 16 times the thickness were used, according to this standard. The test temperature was 23 ± 2 °C. Injection molding was performed according to ISO 19069-2, with a melt temperature of 230 °C used for all materials regardless of melt flow rate.

[0306] h) Tensile test

[0307] For unfilled polymers, the following procedure is used:

[0308] Tensile tests (modulus, fracture stress and strain, and yield stress and strain) were performed at 23°C using Type 1A specimens directly injection molded according to ISO 527-2 (1A) with a crosshead speed of 1 mm / min, in accordance with ISO 527-1. After specimen preparation, the polymer in the specimen was allowed to stand at room temperature for 16 hours or 96 hours before testing to ensure complete polymer crystallization. The corresponding standing times are listed in the following properties.

[0309] For semiconductor compositions containing carbon black, tensile testing is performed on specimens obtained from the strip according to the following procedure:

[0310] First, using a Collin Teach-Line E 20 T strip extruder, with the following temperature settings: 60°C (Zone 1), 220°C (Zone 2), 220°C (Zone 3), and 220°C (Zones 4 to 6), the pellets are extruded into strips with a thickness of approximately 0.6-0.7 mm.

[0311] Then, these strips are placed in the same direction and compression molded according to ISO 19069-2 to produce a plate with a thickness of about 2 mm.

[0312] Subsequently, the 5A sample was punched off the plate and conditioned at a constant temperature of 23°C for at least 96 hours.

[0313] According to ISO 527-1, the tensile properties (tensile strength, elongation at break) of semiconductor materials are determined using 5A (ISO 527-2) specimens.

[0314] According to EN60811-501 standard, a test speed of 25 mm / min is used.

[0315] The load sensor records changes in force, and the elongation meter records changes in elongation.

[0316] i) Charpy notch impact strength

[0317] For unfilled polymers, the following procedure is used:

[0318] Charpy notched impact strength was determined according to ISO 179-1 / 1eA on notched 80mm × 10mm × 4mm specimens (specimens prepared according to ISO 179-1 / 1eA). The test temperature was 23±2℃ or -20±2℃. Injection molding was performed according to ISO 19069-2, and a melt temperature of 230℃ was used for all materials regardless of melt flow rate.

[0319] j) Xylene cold soluble matter (XCS) content

[0320] The amount of xylene-soluble matter in polypropylene was determined according to ISO 16152 (first edition; 2005-07-01).

[0321] A measured amount of sample was dissolved in hot xylene under reflux at 135°C. The solution was then cooled under controlled conditions and maintained at 25°C for 30 minutes to ensure controlled crystallization of the insoluble fraction. This insoluble fraction was then separated by filtration. Xylene was evaporated from the filtrate, leaving the soluble fraction as a residue. The percentage of this fraction was determined by gravimetric analysis.

[0322]

[0323] In the formula:

[0324] m0 is the mass of the sample tested, in grams;

[0325] m1 is the mass of the residue, in grams;

[0326] v0 is the original volume of the solvent taken;

[0327] v1 is the volume of the aliquots used for the determination.

[0328] k) Volume resistivity (VR)

[0329] VR measurement on strip:

[0330] Extrude strips with a thickness of 0.6-0.7 mm and a width of 25 mm using a Collin Teach-Line E 20 T strip extruder, using the following temperature settings: 60°C (Zone 1) and 220°C (Zones 2 to 6). Then place these strips in the same direction and compress them according to ISO 19069-2 to produce flat sheets with a thickness of approximately 3 mm.

[0331] The plate was cut into 15 cm long specimens and conditioned for at least 96 hours at 1 atm and 23 ± 2 °C before testing. The resistance between potential electrodes spaced 10 mm apart was measured using a four-terminal electrode system as described in ISO 3915 (1999). The resistance at high temperature was measured after placing the assembly in a preheated oven for 30 minutes. The volume resistivity was calculated using the formula in ISO 3915 (1999) based on the measured resistance and the sample geometry.

[0332] VR measurement on cable specimens:

[0333] A 13.5 cm long cable sample was conditioned for 5 ± 0.5 hours at 1 atm and 60 ± 2 °C before measurement. The resistance of the outer semiconductor layer was measured according to IEC 60502-2 (2005) using a four-terminal system, but with metal wires pressed onto the semiconductor layer instead of silver-coated electrodes. The distance between the two potential electrodes was 50 mm.

[0334] To measure the resistance of the inner semiconductor layer, the cable was cut in half, and the metal conductor was removed. The volume resistivity was calculated by measuring the resistance between the conductive silver paste coated at both ends of the sample. This is a two-end method with an electrode spacing of approximately 12 cm.

[0335] The resistance at high temperature was measured after the component was placed in a preheated oven for 30 minutes.

[0336] Volume resistivity is calculated from the measured resistance and sample geometry using the formula in IEC 60502-2 (2005).

[0337] l) AC electrical breakdown strength (ACBD)

[0338] AC breakdown testing was performed on 6 / 10kV cables according to CENELEC HD 605 5.4.15.3.4. Therefore, the cable was cut into six 10m effective length test samples (plus terminations). The samples were tested for breakdown using a 50Hz AC step test at ambient temperature according to the following procedure:

[0339] • Start from 18kV and continue for 5 minutes

[0340] • Increase the voltage in 6kV increments every 5 minutes until breakdown occurs.

[0341] The Weibull parameters for the six breakdown values ​​(conductor stress, i.e., the electric field of the inner semiconductor layer) were calculated following the least squares regression procedure described in IEC 62539 (2007). In this paper, the Weibull α parameter refers to the scale parameter of the Weibull distribution, i.e., the voltage value at a failure probability of 0.632. The Weibull β value refers to the shape parameter.

[0342] m) Ash content

[0343] Place 1g of semiconductor material into a quartz crucible. Then place the crucible in a microwave oven preheated to 600°C. After 10 minutes, the organic portion is completely pyrolyzed, and the carbon black content (= ash content) can be calculated based on the weight loss.

[0344] 2. Production of semiconductor compositions

[0345] The following resins were used in the preparation of the propylene copolymer compositions in the examples:

[0346] a) Polymerization of multiphase propylene copolymers HECO1, HECO2 and HECO3

[0347] •catalyst

[0348] The catalysts used in the polymerization processes of the multiphase propylene copolymers HECO1 and HECO3 are Ziegler-Natta catalysts, which are described in patent publications EP491566, EP591224, and EP586390. Triethylaluminum (TEAL) is used as a co-catalyst, and dicyclopentyldimethoxysilane (D-electron donor) is used as the electron donor.

[0349] The catalyst used in the polymerization process of the multiphase propylene copolymer HECO2 is a Ziegler-Natta catalyst, which is described in the Examples section of patent publication WO2015 / 117948. Triethylaluminum (TEAL) is used as a cocatalyst, and dicyclopentyldimethoxysilane (D-electron donor) is used as the electron donor.

[0350] • Polymerization of multiphase propylene copolymer powders A and B

[0351] Multiphase propylene copolymer powders A and B were produced at the Borstar™ plant under the conditions shown in Table 1, in the presence of the polymerization catalyst described above, using one liquid-phase loop reactor and two gas-phase reactors connected in series. The first reaction zone was a loop reactor, and the second and third reaction zones were gas-phase reactors. The matrix phase was polymerized in the loop reactor and the first gas-phase reactor, and the elastomer phase was polymerized in the second gas-phase reactor.

[0352] Table 1: Polymerization of multiphase propylene copolymer powders A and B:

[0353]

[0354] • Preparation of HECO1, HECO2 and HECO3

[0355] The multiphase propylene copolymer powders A and B obtained from the polymerization reaction were mixed together with a stabilizer package in a twin-screw extruder to obtain polypropylene compositions HECO1, HECO2 and HECO3.

[0356] During the compounding process of HECO1, a BNTα-nucleating agent was added, and the composition was de-thawed and cracked to a melt flow rate MFR2 (230°C, 2.16 kg) of 3.9 g / 10 min as described in the Example section of WO2017 / 198633.

[0357] During the compounding process of HECO2, the composition was de-thawed and cracked to a melt flow rate MFR2 (230°C, 2.16 kg) of 3.9 g / 10 min as described in the Examples section of WO 2017 / 198633.

[0358] The production overview of polypropylene HECO1, HECO2 and HECO3 is shown in Table 2.

[0359] Table 2: Compounding of HECO1-3 in a twin-screw extruder:

[0360]

[0361] Stabilizer composition and α-nucleating agent:

[0362] • Stabilizer single pack 1 consists of 29 wt% tetra(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate (CAS No.: 6683-19-8), 58 wt% tris(2,4-di-tert-butylphenyl) phosphite (CAS No.: 31570-04-4), and 13 wt% magnesium oxide (CAS No.: 1309-48-4), all of which are commercially available from various companies.

[0363] • Stabilizer Pack 2 consists of 25.6 wt% tetra(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate (CAS No.: 6683-19-8), 51.3 wt% tris(2,4-di-tert-butylphenyl) phosphite (CAS No.: 31570-04-4), and 23.1 wt% synthetic hydrotalcite (CAS No.: 11097-59-9), all of which are commercially available from various companies.

[0364] • The α-nucleation achieved by BNT is accomplished by adding 2 wt% of a polypropylene homopolymer with an MFR2 (230°C) of 8.0 g / 10 min and a melting temperature of 162°C. This homopolymer is produced in Borealis Nucleation Technology (BNT) using a Ziegler-Natta type catalyst and contains a polymer α-nucleating agent. It is distributed by Borealis AG (Austria).

[0365] The properties of HECO1, HECO2 and HECO3 are listed in Table 3 below.

[0366] Table 3: Characteristics of HECO1, HECO2 and HECO3

[0367]

[0368] • Preparation of semiconductor compositions

[0369] The components of the listed above and below semiconductor compositions were kneaded using a single-screw kneader to obtain semiconductor compositions IE1, IE2, CE1, CE2, CE3, CE4, and CE5. The amounts of the different components in the semiconductor compositions are listed in Table 4 below.

[0370] The carbon black (CB) is Printex Alpha, commercially acquired from Orion Engineered Carbons GmbH.

[0371] RaCo is a random propylene-ethylene copolymer with a melt flow rate (MFR2) of 45 g / 10 min, a melt temperature (Tm) of 150 °C, a flexural modulus of 950 MPa, a tensile modulus of 1050 MPa, and a Charpy notched impact strength of 5.5 kJ / m² at 23 °C. 2 .

[0372] LDPE is a type of low-density polyethylene with a density of 915 kg / m³. 3 (Determined according to ISO 1183-1 / Method A), the melt flow rate MFR2 is 15 g / 10 min, and the melting temperature Tm is 104 °C.

[0373] additive:

[0374] AO1 antioxidant Irganox 1010, commercially obtained from BASF SE;

[0375] AO2 antioxidant Irgafos 168, commercially obtained from BASF SE;

[0376] AO3 antioxidant Irganox PS 802, commercially purchased from BASF SE;

[0377] Irganox MD 1024, a metal passivator, was commercially obtained from BASF SE; and

[0378] AS acid scavenger, zinc stearate.

[0379] Table 4: Composition of Semiconductor Compositions

[0380]

[0381] Semiconductor materials have the following properties listed in Table 5.

[0382] Table 5: Properties of Semiconductor Compositions

[0383]

[0384] nm = Not measured

[0385] Compared to the comparative example, compositions IE1 and IE2 exhibit a superior balance of properties in terms of melt flow rate, tensile strength, elongation at break, and volume resistivity. Furthermore, the strips made from compositions IE1 and IE2 also demonstrate excellent surface smoothness.

[0386] The semiconductor composition CE1 is too sticky during extrusion.

[0387] The strip made from the semiconductor composition CE1 is too brittle.

[0388] Due to the combination of higher melt flow rate, higher tensile strength, and higher elongation at break, the semiconductor compositions of two examples, IE1 and CE3, were selected as the inner and outer semiconductor layers for the production of cables using the same insulating material.

[0389] 3. Production of 10kV cables

[0390] The 10kV test cable was produced on the Maillefer pilot cable production line, which is a type of catenary continuous vulcanization (CCV).

[0391] The conductor cross-sectional area of ​​the cable core is 50 mm². 2 The inner semiconductor layer is made of the semiconductor composition described in Examples IE1 and CE3 above, and has a thickness of 1.0 mm. The insulating layer is made of the polypropylene composition described below, and has a thickness of 3.4 mm. The outer semiconductor layer is made of the semiconductor composition described in Examples IE1 and CE3 above, and has a thickness of 1.0 mm.

[0392] The cable, specifically the cable core, is produced by extrusion using a three-layer co-extrusion die. The insulation extruder is 100 mm in diameter, the conductor shield (inner semiconductor layer) extruder is 45 mm, and the insulation shield (outer semiconductor layer) extruder is 60 mm. The production line speed is 6.0 m / min.

[0393] The vulcanizing tube is 52.5 meters long and consists of a curing section and a subsequent cooling section. The curing section is filled with 10 bar of N2 but is not heated. The 33-meter-long cooling section is filled with water at 20-25°C.

[0394] Then, an AC breakdown test was performed on the pilot cable.

[0395] The polymer composition for the insulating layer (IL) is prepared from HECO1 as described above, which has undergone viscous cracking and BNT nucleation, and compounded with a single package of 0.14 wt% stabilizer. This stabilizer package consists of 29 wt% pentaerythritol tetra(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate (CAS No.: 6683-19-8), 58 wt% tris(2,4-di-tert-butylphenyl) phosphite (CAS No.: 31570-04-4), and 13 wt% magnesium oxide (CAS No.: 1309-48-4), all of which are commercially available from various companies.

[0396] Table 6 shows the electrical performance of 10kV cables in Examples C1 and C2, in which the semiconductor composition IE1 of the present invention with inner and outer semiconductor layers is compared with the comparative semiconductor composition CE3 with inner and outer semiconductor layers.

[0397] Table 6: Electrical properties of 10kV cables C1 and C2

[0398]

[0399] Compared to test cable C2, test cable C1, which has the semiconductor composition IE1 described in this invention in the inner and outer semiconductor layers, exhibits a higher Weibull-α value and a higher Weibull-β value.

[0400] In addition, the volume resistivity of the inner and outer semiconductor layers of the two test cables C1 and C2 was measured at 20°C and 90°C (see Table 7).

[0401] Table 7: Volume resistivity of inner and outer semiconductor layers of C1 and C2

[0402]

[0403] ISC = Inner Semiconductor Layer; OSC = Outer Semiconductor Layer

[0404] For both semiconductor compositions, IE1 and CE3, the volume resistivity increases relatively little with increasing temperature, from 10-12 Ohm·cm at 20°C to 39-47 Ohm·cm only at 90°C. IE1 exhibits an even lower volume resistivity value at 90°C due to its absence of LDPE.

[0405] The main components of IE1 and CE1 (HECO1 and HECO3) have melting temperatures of approximately 150°C, and their crystals do not melt at 90°C. Therefore, only the difference in thermal expansion between the carbon black and the polymer matrix increases the volume resistivity. This is an advantage compared to EVA-based semiconductor layers, where a significant increase in VR (VR) from <25 Ohm·cm at 20°C to 60 Ohm·cm at 90°C is typically observed due to the melting of EVA at approximately 90°C.

Claims

1. A semiconductor composition, wherein, The semiconductor composition comprises: (A) A first copolymer of 25.0 to 67.5 wt% propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms, the first copolymer (A) having: According to ISO 1133, the melt flow rate (MFR2) measured at 230°C and 2.16 kg is 2.0 to 6.0 g / 10 min. Based on the total weight of the first copolymer (A), the soluble fraction (SF) content, as determined by crystallization extraction (CRYSTEX), is greater than 25.0 wt% to 50.0 wt%; and Based on the total weight of the first copolymer (A), quantitative analysis was performed using the crystallization extraction method (CRYSTEX). 13 The total comonomer content, determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy, ranged from 7.5% to 20.0% wt%. (B) A second copolymer of 5.0 to 50.0 wt% propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms, wherein the second copolymer (B) has: According to ISO 1133, the melt flow rate MFR2, measured at 230°C and 2.16 kg, is at least 2.0 g / 10 min; Based on the total weight of the second copolymer (B), the soluble fraction (SF) content, determined by crystallization extraction (CRYSTEX), was 12.0 to 25.0 wt%; and Based on the total weight of the second copolymer (B), quantitative analysis was performed using the crystallization extraction method (CRYSTEX). 13 The total comonomer content, determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy, ranged from 4.0 to 10.0 wt%; and (C) 15.0 to 35.0 wt% carbon black, All weights are based on the total weight of the semiconductor composition.

2. The semiconductor composition according to claim 1, wherein, The soluble fraction (SF) of the first copolymer (A) has: Based on the total amount of monomer units in the soluble fraction (SF) of the first copolymer (A), by quantitative analysis... 13 The amount of comonomer units determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy was 20.0 to 35.0 wt%; and / or The intrinsic viscosity (iV(SF)) measured according to ISO 1628-3 is 150 to 250 cm⁻¹. 3 / g.

3. The semiconductor composition according to claim 1 or 2, wherein, The first copolymer (A) has one or more of the following characteristics: • The melting temperature Tm, determined by DSC analysis according to ISO 11357 / Part 3 / Method C2, is 140 to 159 °C; and / or • The crystallization temperature Tc, determined by DSC analysis according to ISO 11357 / Part 3 / Method C2, is 85 to 125 °C; and / or • The difference between the melting temperature and the crystallization temperature, Tm-Tc, is 20 to 70 °C; and / or • The total intrinsic viscosity, as determined according to ISO 1628-3, is 150 to 350 cm⁻¹. 3 / g; and / or • The flexural modulus, as determined by ISO 178 Method A, is not greater than 470 MPa; and / or • The Charpy notched impact strength at 23°C, as determined by ISO 179-1 / 1eA, is 40 to 110 kJ / m. 2 ; and / or • Complex viscosity η at a frequency of 100 rad / s 100rad / s The range is 750 to 950 Pa·s.

4. The semiconductor composition according to any one of claims 1 to 3, wherein, The first copolymer (A) has undergone viscosity-reducing cracking treatment.

5. The semiconductor composition according to any one of claims 1 to 4, wherein, The soluble fraction (SF) of the second copolymer (B) has: Based on the total amount of monomer units in the soluble fraction (SF) of the second copolymer (B), by quantitative analysis... 13 The amount of comonomer units determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy was 15.0 to 35.0 wt%; and / or The intrinsic viscosity (iV(SF)) measured according to ISO 1628-3 is 90 to 190 cm⁻¹. 3 / g.

6. The semiconductor composition according to any one of claims 1 to 5, wherein, The second copolymer (B) has one or more of the following characteristics: • The melting temperature Tm, as determined by DSC analysis according to ISO 11357 / Part 3 / Method C2, is 130 to 150 °C; and / or • The crystallization temperature Tc, determined by DSC analysis according to ISO 11357 / Part 3 / Method C2, is 80 to 120 °C; and / or • The difference between the melting temperature and the crystallization temperature, Tm-Tc, is 20 to 70 °C; and / or • The total intrinsic viscosity, measured according to ISO 1628-3, is 100 to 250 cm⁻¹. 3 / g; and / or • A flexural modulus greater than 470 MPa as measured according to ISO 178 Method A; and / or • The Charpy notched impact strength at 23°C, measured according to ISO 179-1 / 1eA, ranges from 4.0 to 15.0 kJ / m. 2 ; and / or • Complex viscosity η at a frequency of 100 rad / s 100rad / s The value is 500 to 700 Pa·s.

7. The semiconductor composition according to any one of claims 1 to 6, wherein, The second copolymer (B) has undergone viscosity-reducing cracking treatment.

8. The semiconductor composition according to any one of claims 1 to 7, wherein, Carbon black (C) has one or more of the following properties: • The primary particle size is at least 5 nm, which is defined as the average particle size according to ASTM D3849-14; • Iodine adsorption value determined according to ASTM D-1510-19 is at least 10 mg / g; and / or • The oil absorption value (OAN) determined according to ASTM D2414-19 is at least 30 ml / 100g.

9. The semiconductor composition according to any one of claims 1 to 8, wherein, The semiconductor composition does not contain polyolefins functionalized with monocarboxylic or polycarboxylic acid compounds or derivatives of monocarboxylic or polycarboxylic acid compounds.

10. The semiconductor composition according to any one of claims 1 to 9, wherein, The semiconductor composition is free of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ).

11. The semiconductor composition according to any one of claims 1 to 10, wherein, The semiconductor composition has one or more of the following properties: • The melt flow rate (MFR5) measured according to ISO 1133 at 230°C and 5 kg is 2.0 to 100 g / 10 min; and / or • Melt flow rate (MFR) measured according to ISO 1133 at 230°C and 10 kg 10 12 to 600 g / 10 min; and / or • The density, as determined according to ISO 1183, is between 0.850 and 1.200 g / cm³. 3 ; and / or • Tensile strength of 10.0 to 25.0 MPa, measured at 23°C according to ISO 527-1; and / or • The elongation at break, measured at 23°C according to ISO 527-1, is 350 to 750%.

12. The semiconductor composition according to any one of claims 1 to 11, wherein, The volume resistivity (VR) of the semiconductor composition is from 6.0 to 55.0 Ohm·cm.

13. An article comprising the semiconductor composition of any one of claims 1 to 12.

14. The article of claim 13, wherein, The product is a cable having a semiconductor layer, wherein the semiconductor layer comprises the semiconductor composition.

15. Use of the semiconductor composition of any one of claims 1 to 12 as an inner semiconductor layer and / or outer semiconductor layer of a medium-voltage cable.

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