Polypropylene composition for cable insulation

Abstract

The present invention relates to a cable comprising at least one layer comprising a polypropylene composition comprising: (A) 80.0 to 99.0% by weight, preferably 82.5 to 97.2% by weight, most preferably 85.0 to 95.0% by weight of a copolymer of propylene and comonomer units selected from ethylene and alpha-olefins having 4 to 12 carbon atoms, the copolymer has comonomer units in a total amount of 10.0 to 16.0 wt%, preferably 11.0 to 15.0 wt%, most preferably 12.0 to 14.0 wt%, based on the total amount of monomer units in the copolymer (A) of propylene; a melt flow rate MFR2 of from 0.5 to 5.0 g / 10 min, preferably from 0.8 to 4.5 g / 10 min, also more preferably from 1.0 to 4.3 g / 10 min, and most preferably from 1.2 to 4.0 g / 10 min; a total amount, based on the total weight of the propylene copolymer (A), of 25.0 to 50.0 wt%, preferably 27.5 to 45.0 wt%, more preferably 30.0 to 42.5 wt%, and most preferably 32.5 to 40.0 wt%, of a xylene cold soluble (XCS) fraction; and (B) 1.0 to 20.0 wt%, preferably 2.5 to 17.5 wt%, most preferably 5.0 to 15.0 wt%, of a linear block copolymer comprising styrene, monomer units selected from the group consisting of ethylene, propylene and / or 1-butene, the linear block copolymer having a total content of 1.0 to 30.0 wt%, preferably 2.0 to 27.5 wt%, based on the total weight of the linear block copolymer (B), most preferably from 3.0 to 25.0 wt% of styrene units.

Description

Technical Field

[0001] The present invention relates to a cable comprising an insulation layer comprising at least one layer, preferably an insulation layer, comprising a flexible polypropylene composition. Background Art

[0002] Today, ethylene polymer products are used as insulation and semiconducting shields for low, medium and high voltage cables due to their ease of processing and their favorable electrical properties. In addition, in low voltage applications, polyvinyl chloride (PVC) is also commonly used as an insulating material, usually combined with a softener to achieve the desired softness of the cable. PVC is a thermoplastic that can be used over a wide temperature range by incorporating various plasticizers. For standard PVC, a maximum continuous conductor temperature of 70°C is normal. PVC hardens at low temperatures and use temperatures below -10°C should be avoided. At conductor temperatures exceeding 100°C, the plasticizer migrates out and the material loses its flexibility. However, by adding special plasticizers and stabilizers, PVC materials can be produced for conductor temperatures of 90 to 105°C. But in essence, PVC is mainly used in the 1kV area, because the higher dielectric constant and dissipation factor of the material mean that the loss increases too much at higher voltages, so PVC cables are generally not used above 1kV. Furthermore, in order to maintain a high level of flexibility, softeners must be added to PVC. Insufficient amounts of softeners can significantly reduce the low temperature properties of PVC. These softeners are not always considered to be unproblematic from an environmental point of view, so it is desirable to eliminate them.

[0003] Especially for medium voltage, high voltage and extra high voltage (MV, HV and EHV) cables and high voltage direct current (HVDC) cables, the insulation materials are currently dominated by cross-linked polyethylene polymer (XLPE) products. These products have high operating temperatures, high electrical breakdown strength and good mechanical properties. However, due to its cross-linking, XLPE cannot be recycled by remelting.

[0004] Therefore, attempts are being made to use thermoplastic materials, in particular thermoplastic propylene polymers, as insulation materials for medium, high and extra high voltage (MV, HV and EHV) cables and high voltage direct current (HVDC) cables. Furthermore, grid owners are increasingly interested in cables that can be recycled by remelting.

[0005] Therefore, there is an increasing interest in polymer compositions based on thermoplastic propylene polymers for use in insulation layers of medium voltage (MV), high voltage (HV), extra high voltage (EHV) and high voltage direct current (HVDC) cables.

[0006] Therefore, propylene polymers need to show a good balance of properties with respect to, for example, flexibility, mechanical properties, impact properties and electrical breakdown strength.

[0007] Therefore, there is a need in the art for polypropylene compositions suitable for cable insulation and showing a good balance of properties with respect to flexibility, mechanical properties, impact properties and electrical breakdown strength when used as cable insulation of MV or HV cables. Summary of the invention

[0008] The present invention relates to a cable comprising at least one layer comprising a polypropylene composition comprising

[0009] (A) 80.0 to 99.0 wt%, preferably 82.5 to 97.2 wt%, most preferably 85.0 to 95.0 wt%, based on the total weight of the polypropylene composition, of a copolymer of propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms, the copolymer having

[0010] The total amount of the total amount of monomer units in the propylene-based copolymer (A) is from 10.0 to 16.0% by weight, preferably

[0011] 11.0 to 15.0 wt%, most preferably 12.0 to 14.0 wt% of comonomer units;

[0012] A melt flow rate MFR of 0.5 to 5.0 g / 10 min, preferably 0.8 to 4.5 g / 10 min, still more preferably 1.0 to 4.3 g / 10 min and most preferably 1.2 to 4.0 g / 10 min 2 ;

[0013] a total amount of 25.0 to 50.0 wt.-%, preferably 27.5 to 45.0 wt.-%, more preferably 30.0 to 42.5 wt.-% and most preferably 32.5 to 40.0 wt.-% of xylene cold soluble (XCS) fraction, based on the total weight of the propylene copolymer (A); and

[0014] (B) 1.0 to 20.0 wt.-%, preferably 2.5 to 17.5 wt.-%, most preferably 5.0 to 15.0 wt.-%, based on the total weight of the polypropylene composition, of a linear styrene block copolymer with a midblock containing ethylene, propylene and / or 1-butene sequences, the linear styrene block copolymer having a total content of styrene units of 1.0 to 30.0 wt.-%, preferably 2.0 to 27.5 wt.-%, most preferably 3.0 to 25.0 wt.-%, based on the total weight of the linear block copolymer (B).

[0015] definition

[0016] Heterophasic polypropylene is a propylene-based copolymer having a semi-crystalline matrix phase and an elastomeric phase dispersed therein, the semi-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 distributed in comonomer-rich block structures and propylene-rich block structures.

[0017] Heterophasic polypropylene generally differs from monophasic propylene copolymers since it shows two different glass transition temperatures Tg attributed to the matrix phase and the elastomeric phase.

[0018] Propylene homopolymers are polymers consisting essentially of propylene monomer units. Due to impurities in the monomer feed of commercial polymerization processes, propylene homopolymers may contain up to 0.1 mol% comonomer units, preferably up to 0.05 mol% comonomer units and most preferably up to 0.01 mol% comonomer units.

[0019] The random propylene copolymer is a copolymer of propylene monomer units and comonomer units, wherein the comonomer units are randomly distributed on the polypropylene chain. Therefore, the random propylene copolymer includes a fraction (xylene cold insoluble matter (XCI) fraction) insoluble in xylene in an amount of at least 85 wt %, most preferably at least 88 wt %, based on the total amount of the random propylene copolymer. Therefore, the random propylene copolymer does not contain an elastomeric polymer phase dispersed therein.

[0020] Typically, propylene polymers comprising at least two propylene polymer fractions (components) which have been produced under different polymerization conditions (resulting in different (weight average) molecular weights and / or different comonomer contents of the fractions), preferably by polymerization in a plurality of polymerization stages with different polymerization conditions, are referred to as "multimodal". The prefix "multi" relates to the number of different polymer fractions constituting the propylene polymer. As an example of a multimodal propylene polymer, a propylene polymer consisting of only two fractions is referred to as "bimodal", whereas a propylene polymer consisting of only three fractions is referred to as "trimodal".

[0021] Unimodal propylene polymers consist of one fraction only.

[0022] Accordingly, 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 may also be measured at the different melt flow rates of the fractions) or in comonomer content or in both.

[0023] Block copolymers are polymers containing at least two different types of monomer units arranged in the polymer chain in the form of blocks of one type of monomer unit. Block copolymers are thus different from random copolymers, in which the different types of monomer units are statically distributed in the polymer chain.

[0024] The styrene-ethylene-1-butene-styrene block copolymer comprises a styrene homopolymer block, followed by an ethylene-1-butene elastomer block, and then a styrene homopolymer block in the polymer chain. Thus, two styrene homopolymer blocks are arranged at both ends of the polymer chain.

[0025] The styrene-ethylene-propylene-styrene block copolymer comprises a styrene homopolymer block in the polymer chain, followed by an ethylene-propylene elastomer block, followed by a styrene homopolymer block. Thus, two styrene homopolymer blocks are arranged at both ends of the polymer chain.

[0026] Visbreaking is a post-reactor chemical process for modifying semi-crystalline polymers such as propylene polymers. During the visbreaking process, the propylene polymer backbone is degraded via beta scission, for example with the aid of a peroxide such as an organic peroxide. Degradation is typically used to increase melt flow rate and narrow molecular weight distribution.

[0027] In the following, unless stated otherwise, the amounts are given in % by weight (wt %). DETAILED DESCRIPTION

[0028] Polypropylene composition

[0029] The polypropylene composition in at least one layer of the cable of the present invention comprises

[0030] (A) 80.0 to 99.0 wt%, preferably 82.5 to 97.2 wt%, most preferably 85.0 to 95.0 wt%, based on the total weight of the polypropylene composition, of a copolymer of propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms, the copolymer having

[0031] The total amount of the total amount of monomer units in the propylene-based copolymer (A) is from 10.0 to 16.0% by weight, preferably

[0032] 11.0 to 15.0 wt%, most preferably 12.0 to 14.0 wt% of comonomer units;

[0033] A melt flow rate MFR of 0.5 to 5.0 g / 10 min, preferably 0.8 to 4.5 g / 10 min, still more preferably 1.0 to 4.3 g / 10 min and most preferably 1.2 to 4.0 g / 10 min 2 ;

[0034] a total amount of 25.0 to 50.0 wt.-%, preferably 27.5 to 45.0 wt.-%, more preferably 30.0 to 42.5 wt.-% and most preferably 32.5 to 40.0 wt.-% of xylene cold soluble (XCS) fraction, based on the total weight of the propylene copolymer (A); and

[0035] (B) 1.0 to 20.0 wt.-%, preferably 2.5 to 17.5 wt.-%, most preferably 5.0 to 15.0 wt.-%, based on the total weight of the polypropylene composition, of a linear styrene block copolymer with a midblock containing ethylene, propylene and / or 1-butene sequences, the linear styrene block copolymer having a total content of styrene units of 1.0 to 30.0 wt.-%, preferably 2.0 to 27.5 wt.-%, most preferably 3.0 to 25.0 wt.-%, based on the total weight of the linear block copolymer (B).

[0036] The polypropylene composition preferably comprises a copolymer of propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms (A) in an amount of 80.0 to 99.0 wt.%, preferably 82.5 to 97.2 wt.%, most preferably 85.0 to 95.0 wt.% and a linear styrene block copolymer having a midblock containing ethylene, propylene and / or 1-butene sequences (B) in an amount of 1.0 to 20.0 wt.%, preferably 2.5 to 17.5 wt.%, most preferably 5.0 to 15.0 wt.%, all amounts based on the total weight of the polypropylene composition.

[0037] The polypropylene composition may further comprise polymer components different from components (A) and (B) in an amount of preferably 0.0 to 10.0 wt.-%, based on the total weight of the polypropylene composition.

[0038] In a preferred embodiment the polymer component of the polypropylene composition consists of components (A) and (B).

[0039] In addition to these polymer components, the polypropylene composition may also include one or more additives in an amount of 0.0 to 5.0 wt % based on the gross weight of the polypropylene composition. One or more additives are preferably selected from acid scavengers, antioxidants, α nucleating agents, β nucleating agents, etc. Such additives are commercially available and are described, for example, in the "Plastic Additives Handbook" by Hans Zweifel, the 6th edition (pages 1141 to 1190) in 2009.

[0040] Typically, these additives are added in amounts of 1 to 50,000 ppm for each individual component.

[0041] One or more additives may be added to the polymer components during the blending step.

[0042] Thus, one or more additives may be added to the polymer component in the form of a masterbatch, wherein the one or more additives are blended with a carrier polymer in concentrated amounts. Any optional carrier polymer is calculated as an amount of additive, based on the total amount of the propylene copolymer composition.

[0043] The polypropylene composition preferably has a total amount of 7.5 to 25.0 wt.-%, more preferably 10.0 to 22.5 wt.-% and most preferably 12.5 to 20.0 wt.-% of units derived from ethylene, based on the total amount of monomer units in the polypropylene composition.

[0044] Further, the polypropylene composition preferably has a total amount of propylene derived units of 70.0 to 90.0 wt.-%, more preferably 72.5 to 87.5 wt.-% and most preferably 75.0 to 85.0 wt.-%, based on the total amount of monomer units in the polypropylene composition.

[0045] Still further, the polypropylene composition preferably has a total amount of styrene-derived units of 0.1 to 10.0 wt.-%, more preferably 0.2 to 7.5 wt.-% and most preferably 0.3 to 5.0 wt.-%, based on the total amount of monomer units in the polypropylene composition.

[0046] Furthermore the polypropylene composition preferably has a total amount of 0 to 12.5 wt.-%, more preferably 0 to 10.0 wt.-% and most preferably 0 to 7.5 wt.-% of units derived from 1-butene, based on the total amount of monomer units in the polypropylene composition.

[0047] Furthermore the polypropylene composition preferably has a total amount of 0 to 0.50 wt.-%, more preferably 0 to 0.40 wt.-% and most preferably 0 to 0.30 wt.-% of units derived from butadiene, based on the total amount of monomer units in the polypropylene composition.

[0048] The polypropylene composition preferably has a total amount of xylene cold soluble (XCS) fraction of 30.0 to 55.0 wt.-%, more preferably 32.5 to 52.5 wt.-%, still more preferably 35.0 to 50.0 wt.-% and most preferably 37.5 to 47.5 wt.-%, based on the total weight of the polypropylene composition.

[0049] The xylene cold soluble (XCS) fraction preferably has a total amount of ethylene-derived units of 20.0 to 40.0 wt.-%, more preferably of 22.5 to 37.5 wt.-% and most preferably of 25.0 to 35.0 wt.-%, based on the total amount of monomer units in the xylene cold soluble (XCS) fraction.

[0050] Further, the xylene cold soluble (XCS) fraction preferably has a total amount of 47.5 to 75.0 wt.-%, more preferably 50.0 to 72.5 wt.-% and most preferably 52.5 to 70.0 wt.-% of units derived from propylene, based on the total amount of monomer units in the xylene cold soluble (XCS) fraction.

[0051] Still further, the xylene cold soluble (XCS) fraction preferably has a total amount of units derived from styrene of 0.3 to 15.0 wt.-%, more preferably 0.5 to 12.5 wt.-% and most preferably 0.7 to 10.0 wt.-%, based on the total amount of monomer units in the xylene cold soluble (XCS) fraction.

[0052] Furthermore, the xylene cold soluble (XCS) fraction preferably has a total amount of units derived from 1-butene of 0 to 20.0 wt.-%, more preferably 0 to 17.5 wt.-% and most preferably 0 to 15.0 wt.-%, based on the total amount of monomer units in the xylene cold soluble (XCS) fraction.

[0053] Furthermore, the xylene cold soluble (XCS) fraction preferably has a total amount of units derived from butadiene of 0 to 1.00 wt.-%, more preferably 0 to 0.80 wt.-% and most preferably 0 to 0.60 wt.-%, based on the total amount of monomer units in the xylene cold soluble (XCS) fraction.

[0054] Further, the xylene cold soluble (XCS) fraction preferably has a diameter of 150 to 300 cm 3 / g, preferably 175 to 275cm 3 / g and most preferably 190 to 240 cm 3 / g of intrinsic viscosity measured in decalin.

[0055] Furthermore, the xylene cold soluble (XCS) fraction preferably has a weight average molecular weight Mw of 150000 to 300000 g / mol, more preferably 175000 to 325000 g / mol and most preferably 200000 to 275000 g / mol.

[0056] Furthermore, the xylene cold soluble (XCS) fraction preferably has a polydispersity index, which is the ratio of weight average molecular weight to number average molecular weight, Mw / Mn, of 3.5 to 8.5, preferably 3.7 to 8.0 and most preferably 4.0 to 7.5.

[0057] Further, the polypropylene composition has preferably a total amount of 45.0 to 70.0 wt.-%, more preferably 47.5 to 67.5 wt.-%, still more preferably 50.0 to 65.0 wt.-% and most preferably 52.5 to 62.5 wt.-% of the fraction insoluble in cold xylene (XCI), based on the total weight of the polypropylene composition.

[0058] In the polypropylene composition the xylene cold soluble (XCS) fraction and the fraction insoluble in cold xylene (XCI) add up to 100 wt.-% of the polypropylene composition.

[0059] The fraction insoluble in cold xylene (XCI) preferably has a total amount of ethylene-derived units of 0.7 to 10.0 wt.-%, more preferably 1.0 to 8.5 wt.-% and most preferably 2.5 to 7.5 wt.-%, based on the total amount of monomer units in the fraction insoluble in cold xylene (XCI).

[0060] Further, the fraction insoluble in cold xylene (XCI) preferably has a total amount of 85.0 to 99.0 wt.-%, more preferably 87.5 to 97.5 wt.-% and most preferably 90.0 to 96.0 wt.-% of units derived from propylene, based on the total amount of monomer units in the fraction insoluble in cold xylene (XCI).

[0061] Still further, the fraction insoluble in cold xylene (XCI) preferably has a total amount of units derived from styrene of 0 to 1.00 wt%, more preferably 0 to 0.50 wt% and most preferably 0 to 0.20 wt%, based on the total amount of monomer units in the fraction insoluble in cold xylene (XCI).

[0062] Furthermore, the fraction insoluble in cold xylene (XCI) preferably has a total amount of units derived from 1-butene of 0 to 2.5 wt.-%, more preferably 0 to 2.0 wt.-% and most preferably 0 to 1.5 wt.-%, based on the total amount of monomer units in the fraction insoluble in cold xylene (XCI).

[0063] Furthermore, the fraction insoluble in cold xylene (XCI) preferably has a total amount of units derived from butadiene of 0 to 0.20 wt.-%, more preferably 0 to 0.15 wt.-% and most preferably 0 to 0.10 wt.-%, based on the total amount of monomer units in the fraction insoluble in cold xylene (XCI).

[0064] Further, the fraction insoluble in cold xylene (XCI) preferably has a carbonyl content of 200 to 375 cm 3 / g, preferably 225 to 350cm 3 / g and most preferably 250 to 325 cm 3 / g of intrinsic viscosity measured in decalin.

[0065] Furthermore, the fraction insoluble in cold xylene (XCI) preferably has a weight average molecular weight Mw of 250,000 to 450,000 g / mol, more preferably 275,000 to 425,000 g / mol and most preferably 300,000 to 400,000 g / mol.

[0066] Furthermore, the fraction insoluble in cold xylene (XCI) preferably has a polydispersity index, which is the ratio of weight average molecular weight to number average molecular weight, Mw / Mn, of 3.5 to 7.5, preferably 4.0 to 7.0 and most preferably 4.5 to 6.5.

[0067] The ratio of the intrinsic viscosities of the XCI fraction to the XCS fraction (IV(XCI) / IV(XCS)) of the polypropylene composition is preferably in the range of 1.0 to 1.7, more preferably in the range of 1.0 to 1.5 and most preferably in the range of 1.1 to 1.4.

[0068] The weight average molecular weight ratio of the XCI fraction to the XCS fraction (Mw(XCI) / Mw(XCS)) of the polypropylene composition is preferably in the range of 1.35 to 1.75, more preferably in the range of 1.40 to 1.70.

[0069] The polypropylene composition preferably has a melt flow rate MFR of 0.5 to 2.5 g / 10 min, preferably 0.8 to 2.2 g / 10 min, still more preferably 1.0 to 2.0 g / 10 min and most preferably 1.2 to 1.9 g / 10 min. 2 .

[0070] The polypropylene composition preferably has a flexural modulus of 130 MPa to 350 MPa, more preferably of 150 MPa to 340 MPa and most preferably of 175 MPa to 325 MPa.

[0071] Preferably, the polypropylene composition has a strength of 50 to 110 kJ / m 2 , more preferably 65 to 100 kJ / m 2 and most preferably 70 to 95 kJ / m 2 The Charpy notched impact strength at 23°C.

[0072] Further, the polypropylene composition preferably has a strength of 7.5 to 80.0 kJ / m 2 , more preferably 8.5 to 75.0 kJ / m 2 and most preferably 9.0 to 70.0 kJ / m 2 The Charpy notched impact strength at -20°C.

[0073] Further, the polypropylene composition has a melting temperature Tm of 140 to 159 °C, preferably 143 to 157 °C and most preferably 145 to 153 °C.

[0074] Furthermore, the polypropylene composition preferably has a crystallization temperature Tc of 85 to 130 °C, more preferably of 87 to 128 °C and most preferably of 90 to 125 °C.

[0075] The difference between the melting temperature and the crystallization temperature Tm-Tc is preferably in the range of 20 to 65°C, preferably in the range of 25 to 60°C and most preferably in the range of 27 to 55°C.

[0076] The polypropylene composition preferably has at least two glass transition temperatures. The two glass transition temperatures are attributable to the matrix phase (Tg(matrix)) and the elastomeric phase (Tg(EP)).

[0077] Further, the polypropylene composition has a glass transition temperature Tg(matrix) due to the matrix phase preferably in the range of -1.0 to -15.0 °C, preferably in the range of -2.5 to -12.5 °C and most preferably in the range of -4.0 to -10.0 °C.

[0078] Still further, the polypropylene composition preferably has a glass transition temperature Tg(EP) due to the elastomeric phase of -35.0 to -55.0 °C, preferably -37.5 to -52.5 °C and most preferably -40.0 to -50.0 °C.

[0079] Preferably, the polypropylene composition has a shear thinning index SHI of 2.5 to 20.0, more preferably of 5.0 to 17.5 and most preferably of 7.5 to 15.0. 1 / 100 .

[0080] Further, the polypropylene composition preferably has s of 1.0 to 4.0 -1 , more preferably 1.5 to 3.5 s -1 and most preferably 2.0 to 3.0s -1 The polydispersity index PI of

[0081] Preferably, the polypropylene composition is prepared by melt blending components (A) and (B), optional additional polymer components and optional other additives, all as described above or below.

[0082] It is preferred that the polypropylene composition does not comprise, ie is free of, dielectric fluids such as eg described in EP 2 739 679.

[0083] In the following, copolymers (A) of propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms (abbreviated as “copolymer of propylene (A)” or component (A)) and linear styrene block copolymers (B) having a midblock containing ethylene, propylene and / or 1-butene sequences (abbreviated as “linear block copolymer (B)” or component (B)) are described in more detail.

[0084] Copolymer of propylene (A)

[0085] The polypropylene composition according to the present invention comprises a copolymer (A) of propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms (hereinafter referred to as "copolymer of propylene (A)").

[0086] The comonomer units are selected from ethylene and α-olefins having 4 to 12 carbon atoms, such as ethylene, 1-butene, 1-hexene or 1-octene. The copolymer of propylene (A) may comprise one type of comonomer units or two or more types, for example two types of comonomer units. It is preferred that the copolymer of propylene (A) comprises one type of comonomer units. Ethylene is particularly preferred.

[0087] The copolymer of propylene (A) preferably has a total amount of 10.0 to 16.0 wt%, preferably 11.0 to 15.0 wt%, most preferably 12.0 to 14.0 wt% of comonomer units, preferably ethylene, based on the total amount of monomer units in the copolymer of propylene (A).

[0088] It is preferred that the copolymer of propylene (A) is a heterophasic copolymer of propylene.

[0089] The heterophasic propylene copolymer has a matrix phase and an elastomeric phase dispersed in the matrix phase.

[0090] The matrix phase is preferably a propylene random copolymer.

[0091] The comonomer units of the random copolymer of propylene of the matrix phase are usually the same as those of the copolymer of propylene as described above. The comonomer units are preferably selected from ethylene and alpha-olefins with 4 to 12 carbon atoms, such as ethylene, 1-butene, 1-hexene or 1-octene. The random copolymer of propylene of the matrix phase can contain one type of comonomer units or two or more types, such as two types of comonomer units. It is preferred that the random copolymer of propylene of the matrix phase contains one type of comonomer units. Ethylene is particularly preferred.

[0092] Heterophasic propylene copolymers are typically characterized by comprising at least two glass transition temperatures. The two glass transition temperatures are attributable to the matrix phase (Tg(matrix)) and the elastomeric phase (Tg(EP)).

[0093] The heterophasic propylene copolymer preferably has a glass transition temperature Tg(matrix) due to the matrix phase in the range of -1.0 to -15.0 °C, preferably in the range of -2.5 to -12.5 °C and most preferably in the range of -5.0 to -10.0 °C.

[0094] Further, the heterophasic propylene copolymer preferably has a glass transition temperature Tg(EP) due to the elastomeric phase in the range of -40.0 to -55.0 °C, preferably in the range of -42.5 to -52.5 °C, most preferably in the range of -45.0 to -50.0 °C.

[0095] In copolymers (A) of propylene, such as heterophasic propylene copolymers, the matrix phase and the elastomeric phase cannot usually be separated accurately from each other. In order to characterize the matrix phase and the elastomeric phase of heterophasic polypropylene copolymers, several methods are known. One method is to extract the fraction containing the majority of the elastomeric phase with xylene, thereby separating the xylene cold insoluble (XCI) fraction from the xylene cold soluble (XCS) fraction. The XCS fraction contains the majority of the elastomeric phase and only a small portion of the matrix phase, while the XCI fraction contains the majority of the matrix phase and only a small portion of the elastomeric phase.

[0096] The copolymer of propylene (A) preferably has a total amount of xylene cold soluble (XCS) fraction of 25.0 to 50.0 wt.-%, more preferably of 27.5 to 45.0 wt.-%, still more preferably of 30.0 to 42.5 wt.-% and most preferably of 32.5 to 40.0 wt.-%, based on the total weight of the copolymer of propylene (A).

[0097] The xylene cold soluble (XCS) fraction preferably has comonomer units, preferably ethylene, in an amount of 23.0 to 35.0 wt.-%, more preferably 23.5 to 32.5 wt.-% and most preferably 24.0 to 30.0 wt.-% based on the total amount of monomer units in the xylene cold soluble (XCS) fraction.

[0098] Further, the xylene cold soluble (XCS) fraction preferably has a carbon content of 150 to 350 cm3 / g, preferably 200 to 325 cm3 / g. 3 / g and most preferably 225 to 300 cm 3 / g of intrinsic viscosity measured in decalin.

[0099] Furthermore, the xylene cold soluble (XCS) fraction preferably has a weight average molecular weight Mw of 185000 to 350000 g / mol, more preferably 200000 to 325000 g / mol and most preferably 210000 to 315000 g / mol.

[0100] Furthermore, the xylene cold soluble (XCS) fraction preferably has a polydispersity index, which is the ratio of weight average molecular weight to number average molecular weight, Mw / Mn, of 3.5 to 8.5, preferably 3.7 to 8.0 and most preferably 4.0 to 7.5.

[0101] Further, the copolymer of propylene (A) has preferably a total amount of 50.0 to 75.0 wt.-%, more preferably 55.0 to 72.5 wt.-%, still more preferably 57.5 to 70.0 wt.-% and most preferably 60.0 to 67.5 wt.-% of the fraction insoluble in cold xylene (XCI), based on the total weight of the copolymer of propylene (A).

[0102] The fraction insoluble in cold xylene (XCI) preferably has comonomer units, preferably ethylene, in an amount of 3.0 to 9.0 wt.-%, preferably 4.0 to 8.5 wt.-% and most preferably 4.5 to 7.5 wt.-%, based on the total amount of monomer units in the fraction insoluble in cold xylene (XCI).

[0103] Further, the fraction insoluble in cold xylene (XCI) preferably has a carbonyl content of 185 to 350 cm 3 / g, preferably 220 to 325cm 3 / g and most preferably 210 to 300 cm 3 / g of intrinsic viscosity measured in decalin.

[0104] Furthermore, the fraction insoluble in cold xylene (XCI) preferably has a weight average molecular weight Mw of 225,000 to 450,000 g / mol, more preferably 240,000 to 425,000 g / mol and most preferably 260,000 to 400,000 g / mol.

[0105] Furthermore, the fraction insoluble in cold xylene (XCI) preferably has a polydispersity index, which is the ratio of weight average molecular weight to number average molecular weight, Mw / Mn, of 3.5 to 7.5, preferably 3.7 to 7.0 and most preferably 4.0 to 6.5.

[0106] The ratio of the intrinsic viscosity of the XCI fraction to the XCS fraction of the copolymer of propylene is preferably in the range of 0.9 to 1.5, more preferably in the range of 1.0 to 1.4 and most preferably in the range of 1.0 to 1.3.

[0107] The copolymer of propylene (A) preferably has a melt flow rate MFR of 0.5 to 2.5 g / 10 min, preferably 0.8 to 2.3 g / 10 min, still more preferably 1.0 to 2.0 g / 10 min and most preferably 1.2 to 1.7 g / 10 min. 2 .

[0108] The copolymer of propylene (A) preferably has a flexural modulus of 130 to 400 MPa, more preferably of 150 to 390 MPa and most preferably of 175 to 380 MPa.

[0109] Preferably, the copolymer of propylene (A) has a molecular weight of 50 to 110 kJ / m 2 , more preferably 65 to 100 kJ / m 2 and most preferably 75 to 95 kJ / m 2 The Charpy notched impact strength at 23°C.

[0110] Further, the copolymer of propylene (A) preferably has an organic acid content of 5.0 to 10.0 kJ / m 2 , more preferably 5.5 to 9.0 kJ / m 2 and most preferably 6.0 to 8.0 kJ / m 2 The Charpy notched impact strength at -20°C.

[0111] Further, the copolymer of propylene (A) has a melting temperature Tm of 140 to 159°C, preferably 143 to 157°C and most preferably 145 to 153°C.

[0112] Furthermore, the copolymer of propylene (A) has a crystallization temperature Tc of 85 to 130 °C, preferably 87 to 128 °C and most preferably 90 to 125 °C.

[0113] The difference between the melting temperature and the crystallization temperature Tm-Tc is preferably in the range of 20 to 65°C, preferably in the range of 25 to 60°C and most preferably in the range of 27 to 55°C.

[0114] It is preferred that the copolymer of propylene (A) has a molecular weight of 185 to 350 cm 3 / g, preferably 200 to 325cm 3 / g and most preferably 210 to 300 cm 3 / g of intrinsic viscosity measured in decalin.

[0115] The copolymer of propylene (A) can be polymerized in a sequential multistage polymerization process, i.e. in 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, such as three or four polymerization reactors are connected in series. The term "polymerization reactor" shall indicate that the main polymerization occurs. Thus, in the case where the process consists of four polymerization reactors, this definition does not exclude the option that the entire process includes a prepolymerization step, for example in a prepolymerization reactor.

[0116] When the copolymer of propylene (A) is a heterophasic propylene copolymer the matrix phase of the heterophasic propylene copolymer is polymerized in a first polymerisation reactor to produce a unimodal matrix phase or in a first and a second polymerisation reactor to produce a multimodal matrix phase.

[0117] The elastomeric phase of the heterophasic propylene copolymer is preferably polymerized in the presence of the matrix phase in one or two subsequent polymerization reactors to produce a unimodal elastomeric phase or a multimodal elastomeric phase.

[0118] Preferably, the polymerization reactor is selected from a slurry phase reactor, such as a loop reactor and / or a gas phase reactor, such as a fluidized bed reactor, more preferably selected from a loop reactor and a fluidized bed reactor.

[0119] A preferred sequential multistage polymerization process is a "loop-gas phase" process such as that developed by Borealis A / S of Denmark (known as Technology), for example the methods described in patent literature, 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.

[0120] Another suitable slurry-gas phase process is LyondellBasell's method.

[0121] Suitable sequential polymerization processes for polymerizing copolymers (A), preferably heterophasic propylene copolymers, of propylene are for example disclosed in EP 1 681 315 A1 or WO 2013 / 092620 A1.

[0122] The copolymer (A) of propylene, preferably a heterophasic propylene copolymer, can be polymerized in the presence of a Ziegler-Natta catalyst or a single site catalyst.

[0123] Suitable Ziegler-Natta catalysts are disclosed, for example, in US Pat. No. 5,234,879, WO 92 / 19653, WO 92 / 19658, WO 99 / 33843, WO 03 / 000754, WO 03 / 000757, WO 2013 / 092620 A1 or WO 2015 / 091839.

[0124] Suitable single-site catalysts are disclosed, for example, in WO 2006 / 097497, WO 2011 / 076780 or WO 2013 / 007650.

[0125] The Ziegler-Natta catalysts or single-site catalysts in the above list are only suitable for the production of isotactic polypropylene.

[0126] The copolymer of propylene (A) is preferably an isotactic copolymer of propylene.

[0127] The copolymer of propylene (A) is preferably not subjected to a visbreaking step as described for example in WO 2013 / 092620 A1.

[0128] Heterophasic propylene copolymer resins suitable as copolymers (A) of propylene are also commercially available. These resins usually already have stabilizer packages added. Therefore, when using commercially available resins as copolymers of propylene, the addition of the additives described above may have to be adjusted to the additives already present.

[0129] Linear block copolymer (B)

[0130] The polypropylene composition according to the present invention comprises a linear styrene block copolymer (B) having a midblock comprising ethylene, propylene and / or 1-butene sequences (hereinafter referred to as "linear block copolymer (B)").

[0131] The linear block copolymer (B) is preferably a styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) or a styrene-ethylene-propylene-styrene triblock copolymer (SEPS).

[0132] In one embodiment, the linear block copolymer (B) is a styrene-ethylene-1-butene-styrene triblock copolymer (SEBS).

[0133] The styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) preferably has units derived from ethylene in an amount of 85.0 to 98.9 wt.-%, more preferably 89.0 to 97.7 wt.-% and most preferably 91.5 to 96.5 wt.-%, based on the total amount of monomer units in the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS).

[0134] Still further, the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) preferably has units derived from styrene in an amount of 1.0 to 10.0 wt%, more preferably 2.0 to 7.5 wt% and most preferably 3.0 to 6.0 wt%, based on the total amount of monomer units in the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS).

[0135] Furthermore, the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) preferably has units derived from butadiene in an amount of 0.1 to 5.0 wt %, more preferably 0.2 to 3.5 wt % and most preferably 0.3 to 2.5 wt %, based on the total amount of monomer units in the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS).

[0136] The styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) preferably has a melt flow rate MFR of 1.0 to 10.0 g / 10 min, preferably 2.0 to 8.5 g / 10 min, most preferably 2.5 to 7.5 g / 10 min. 2 .

[0137] Further, the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) has a melting temperature Tm of 50 to 100°C, preferably 55 to 95°C and most preferably 60 to 90°C.

[0138] Furthermore, the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) preferably has a crystallization temperature Tc of 5 to 50°C, more preferably 7 to 45°C and most preferably 10 to 40°C.

[0139] The difference between the melting temperature and the crystallization temperature Tm-Tc is preferably in the range of 20 to 65°C, preferably in the range of 25 to 60°C and most preferably in the range of 30 to 55°C.

[0140] Further, the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) preferably has a glass transition temperature of -30 to -50°C, preferably -32 to -47°C and most preferably -35 to -45°C.

[0141] Preferably, the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) has a shear thinning index SHI of 1.0 to 7.5, more preferably 1.2 to 6.5 and most preferably 1.5 to 6.0. 1 / 100 .

[0142] Further, the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) preferably has a molecular weight of 0.2 to 1.5 s -1 , more preferably 0.4 to 1.3 s -1 and most preferably 0.6 to 1.1 s -1 The polydispersity index PI of

[0143] Further, the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) preferably has a molecular weight of 860 to 895 kg / m 3, more preferably 865 to 890 kg / m 3 and most preferably 870 to 885 kg / m 3 density.

[0144] In the presence of styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) as linear block copolymer (B) the polypropylene composition preferably has the following comonomer content when measured by NMR measurement:

[0145] a total amount of 70.0 to 85.0 wt%, more preferably 72.5 to 82.5 wt%, most preferably 75.0 to 80.0 wt% of units derived from propylene;

[0146] a total amount of 7.5 to 22.5 wt%, more preferably 10.0 to 20.0 wt%, most preferably 12.5 to 17.5 wt% of units derived from ethylene;

[0147] a total amount of 1.0 to 12.5 wt.%, more preferably 2.0 to 10.0 wt.%, most preferably 3.0 to 7.5 wt.% of units derived from 1-butene;

[0148] a total amount of 0.01 to 0.50 wt%, more preferably 0.02 to 0.40 wt%, most preferably 0.05 to 0.30 wt% of units derived from butadiene; and

[0149] a total amount of 0.1 to 1.5 wt%, more preferably 0.2 to 1.2 wt%, most preferably 0.3 to 1.0 wt% of units derived from styrene,

[0150] All amounts are based on the total molar amount of monomer units in the polypropylene composition.

[0151] In the presence of styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) as linear block copolymer (B), the polypropylene composition preferably has a xylene cold soluble (XCS) fraction having preferably

[0152] a total amount of 47.5 to 62.5 wt%, more preferably 50.0 to 60.0 wt%, most preferably 52.5 to 57.5 wt% of units derived from propylene;

[0153] a total amount of 20.0 to 40.0 wt%, more preferably 22.5 to 37.5 wt%, most preferably 25.0 to 35.0 wt% of units derived from ethylene;

[0154] a total amount of 5.0 to 20.0 wt. %, more preferably 7.5 to 17.5 wt. %, most preferably 10.0 to 15.0 wt. % of units derived from 1-butene;

[0155] a total amount of 0.05 to 1.00 wt%, more preferably 0.10 to 0.80 wt%, most preferably 0.15 to 0.60 wt% of units derived from butadiene; and

[0156] a total amount of 0.3 to 2.5 wt. %, more preferably 0.5 to 2.0 wt. %, most preferably 0.7 to 1.5 wt. % of units derived from styrene,

[0157] All amounts are based on the total molar amount of monomer units in the xylene cold soluble (XCS) fraction; and / or

[0158] The polypropylene composition preferably has a fraction insoluble in cold xylene (XCI), the fraction insoluble in cold xylene (XCI) preferably having

[0159] a total amount of 85.0 to 99.0 wt%, more preferably 87.5 to 97.5 wt%, most preferably 90.0 to 95.0 wt% of units derived from propylene;

[0160] a total amount of 0.7 to 10.0 wt%, more preferably 1.0 to 8.0 wt%, most preferably 2.5 to 7.5 wt% of units derived from ethylene;

[0161] A total amount of 0.1 to 2.5 wt%, more preferably 0.1 to 2.0 wt%, most preferably 0.1 to 1.5 wt% of units derived from 1-butene;

[0162] a total amount of 0 to 0.20 wt%, more preferably 0 to 0.15 wt%, most preferably 0 to 0.10 wt% of units derived from butadiene; and

[0163] a total amount of 0 to 0.20 wt. %, more preferably 0 to 0.15 wt. %, most preferably 0 to 0.10 wt. % of units derived from styrene units,

[0164] All amounts are based on the total molar amount of monomer units in the fraction insoluble in cold xylene (XCI).

[0165] In another embodiment, the linear block copolymer (B) is a styrene-ethylene-propylene-styrene triblock copolymer (SEPS).

[0166] The styrene-ethylene-propylene-styrene triblock copolymer (SEPS) preferably has a total content of styrene units of 10.0 to 30.0 wt%, preferably 12.5 to 27.5 wt%, most preferably 15.0 to 25.0 wt%, based on the total weight of the linear block copolymer (B).

[0167] Further, the styrene-ethylene-propylene-styrene triblock copolymer (SEPS) preferably has a weight ratio of styrene to ethylene / propylene (S / EP) of 10.0:9.0 to 30.0:70.0, more preferably 12.5:87.5 to 27.5:72.5, most preferably 15.0:85.0 to 25.0:75.0.

[0168] Still further, the styrene-ethylene-propylene-styrene triblock copolymer (SEPS) preferably has a melt flow rate MFR measured at 230°C and 5 kg according to ASTM D 1238 of 1.0 to 25.0 g / 10 min, preferably 2.5 to 22.5 g / 10 min, most preferably 5.0 to 20.0 g / 10 min. 5 .

[0169] In addition, the styrene-ethylene-propylene-styrene triblock copolymer (SEPS) preferably has a molecular weight of 880 to 915 kg / m 3 , preferably 885 to 910 kg / m 3 , most preferably 890 to 905 kg / m 3 Density determined according to ASTM D 792.

[0170] Furthermore, the styrene-ethylene-propylene-styrene triblock copolymer (SEPS) preferably has a Shore A hardness of 40 to 75, preferably 45 to 70, most preferably 50 to 65, measured according to ASTM D 2240.

[0171] The linear block copolymer (B) can be produced by any suitable method for producing a linear block copolymer comprising styrene, monomer units selected from ethylene, propylene and / or 1-butene. Styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) is usually produced by hydrogenating styrene-butadiene-styrene block copolymer (SBS). Styrene-ethylene-propylene-styrene block copolymer (SEPS) is usually produced by hydrogenating styrene-isoprene-styrene block copolymer (SIS).

[0172] Styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) resins and styrene-ethylene-propylene-styrene triblock copolymer (SEPS) resins suitable as linear block copolymers (B) are also commercially available. These resins usually already have stabilizer packages added. Therefore, when using commercially available resins as linear block copolymers (B), the addition of the additives described above may have to be adjusted to the additives already present.

[0173] cable

[0174] The present invention relates to a cable comprising at least one layer comprising a polypropylene composition as defined above or as defined below.

[0175] The cable preferably comprises an insulation layer comprising a polypropylene composition as described above or below.

[0176] The cable generally comprises at least one conductor and at least one insulation layer comprising a polypropylene composition as described above or below.

[0177] In this article, the term "conductor" above and below means that the conductor includes one or more wires. The wire can be used for any purpose, and can be, for example, an optical line, a telecommunication line or an electric wire. In addition, the cable can include one or more such conductors. Preferably, the conductor is an electrical conductor and includes one or more metal wires. The cable is preferably a power cable. A power cable is defined as a cable for transmitting energy that works at any voltage (usually works at a voltage higher than 1kV). The voltage applied to the power cable can be alternating current (AC), direct current (DC) or transient (pulse). The polypropylene composition of the present invention is very suitable for power cables, particularly for power cables (medium voltage (MV) cables) working at a voltage of 6kV to 36kV and power cables working at a voltage higher than 36kV, referred to as high voltage (HV) cables and extra-high voltage (EHV) cables, and it is well known that EHV cables work at very high voltages. These terms have well-known meanings and represent the working level of such cables.

[0178] For low voltage applications, the cable system typically consists of a conductor and an insulating layer comprising a polypropylene composition as described above or below, or a conductor, an insulating layer comprising a polypropylene composition as described above or below and an additional sheath layer, or a conductor, a semiconducting layer and an insulating layer comprising a polypropylene composition as described above or below.

[0179] For medium and high voltage applications the cable system usually consists of a conductor, an inner semiconductive layer, an insulating layer comprising a polypropylene composition as described above or below and an outer semiconductive layer optionally covered by an additional jacket layer.

[0180] The mentioned semiconductive layer preferably comprises, more preferably consists of, a thermoplastic polyolefin composition, preferably a polyethylene composition or a polypropylene composition comprising a sufficient amount of a conductive solid filler, preferably carbon black. It is preferred that the thermoplastic polyolefin composition of the semiconductive layer(s) is a polypropylene composition, more preferably a polypropylene composition comprising as polymer component a heterophasic propylene copolymer. It is especially preferred that the thermoplastic polyolefin composition of at least one semiconductive layer, preferably both semiconductive layers of the cable comprises the same copolymer of propylene as the insulation layer, i.e. a copolymer of propylene as described above or below.

[0181] The cable comprising an insulation layer comprising the polypropylene composition according to the present invention as described above shows good AC electrical breakdown strength in the form of Weibull alpha-value and Weibull beta-value.

[0182] The cable preferably has a Weibull alpha value of 35.0 to 65.0 kV / mm, preferably 37.5 to 65.0 kV / mm and most preferably 40.0 to 65.0 kV / mm when measured on a 10 kV cable.

[0183] Still further, the cable preferably has a Weibull Beta value of 5.0 to 250.0, preferably 5.5 to 250.0, most preferably 6.0 to 250.0, when measured on a 10 kV cable.

[0184] Thus, the insulation layer comprising the polypropylene composition according to the present invention can be used in medium and high voltage cables.

[0185] In still another aspect the present invention relates to the use of a polypropylene composition as described above or below as cable insulation for medium and high voltage cables.

[0186] The medium voltage and high voltage cables preferably meet all performance requirements as described above and below for cables.

[0187] Benefits of the invention:

[0188] The polypropylene composition shows a good balance of properties with respect to high flexibility, good mechanical strength, good impact properties and high crystallization and melting temperatures, which allows it to be used as cable insulation, e.g. for medium and high voltage cables at high operating temperatures. The flexibility and impact properties can be further improved by adding a linear block copolymer (B) to the polypropylene composition, thereby maintaining high crystallization and melting temperatures.

[0189] It has been found that the polypropylene composition can be easily compounded to prepare insulation layers even at a melt flow rate as low as 0.5 to 2.5 g / 10 min without the need to increase the melt flow rate via visbreaking the composition or the copolymer of propylene (A).

[0190] The cable comprising the insulation layer comprising the polypropylene composition of the present invention surprisingly shows good AC breakdown strength in the form of Weibull α value and Weibull β value. Thus, the addition of the linear block copolymer (B) to the polypropylene composition further improves the AC breakdown strength compared to the polypropylene composition comprising only the copolymer (A) of propylene as polymer compound.

[0191] Good AC breakdown strength in the form of Weibull alpha and Weibull beta values ​​can be obtained without adding dielectric fluids such as described in EP 2739679 for example.

[0192] Examples

[0193] The following definitions of terms and assay methods apply in the above general description of the invention as well as in the following examples, unless defined otherwise.

[0194] 1. Measurement method

[0195] a) Melt flow rate (MFR) 2 )

[0196] Melt flow rate is the amount of polymer, in grams, which a test apparatus standardized to ISO 1133 or ASTM D1238 will extrude in 10 minutes at a specific temperature and under a specific load.

[0197] Melt flow rate (MFR) of propylene-based polymers and polypropylene compositions 2 It is measured according to ISO 1133 at 230°C under a load of 2.16 kg.

[0198] Melt flow rate MFR of linear styrene block copolymers 2 It is measured according to ISO 1133 at 230°C under a load of 2.16 kg.

[0199] Melt flow rate MFR of linear styrene block copolymers 5It is measured according to ISO 1133 at 230°C under a load of 5 kg.

[0200] Melt flow rate can also be measured according to ASTM D1238.

[0201] b) Density

[0202] Density was measured according to ISO 1183. Sample preparation was done by compression molding according to ISO 17855-2.

[0203] Density can also be measured according to ASTM D 792.

[0204] c) Comonomer content

[0205] Method I (HECO)

[0206] Quantification of comonomer content of poly(propylene-co-ethylene) copolymers

[0207] Use for 1 H and 13 Quantitative measurements were recorded in solution on a Bruker Avance NEO 400 NMR spectrometer operating at 400.15 and 100.62 MHz, respectively. 13 C{ 1 H} NMR spectroscopy. Nitrogen was used for all pneumatics and all spectra were 13 C optimized 10 mm extended temperature probe was recorded at 125 °C. Approximately 200 mg of the material was mixed with chromium(III) acetylacetonate (Cr(acac) 3 ) and about 3 mg of BHT (2,6-di-tert-butyl-4-methylphenol, CAS 128-37-0) were dissolved in 3 ml of 1,2-tetrachloroethane-d 2 (TCE-d 2 ) to obtain a 60 mM solution of the relaxation agent in the solvent {8}. To ensure a homogeneous solution, the NMR tube was further heated in a rotary oven for at least 1 hour after initial sample preparation in a heating block. After insertion into the magnet, the tube was rotated at 10 Hz. This setup was chosen primarily for high resolution and was quantitatively required for accurate ethylene content quantification. Standard single pulse excitation without NOE was used, using an optimized tip angle, 1 s recycle delay, and a two-stage WALTZ16 decoupling scheme {3, 4}. A total of 6144 (6k) transients were collected for each spectrum. Quantification was performed using a dedicated computer program 13 C{ 1The H} NMR spectra were processed, integrated and the relevant quantitative properties were determined from the integration. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm using the chemical shift of the solvent. This approach allows for comparable references even if this structural unit is not present. Characteristic signals corresponding to the incorporation of ethylene were observed {7}.

[0208] Using the method of Wang et al. {6}, we 13 C{ 1 The comonomer fraction is quantified by integrating multiple signals over the entire spectral area in the H} spectrum. This approach was chosen for its robustness and ability to account for the presence of regio defects when required. The integration area was slightly adjusted to improve applicability over the entire range of comonomer content encountered.

[0209] For systems where only isolated ethylene in the PPEPP sequence is observed, the method of Wang et al. was modified to reduce the effect of non-zero integrals at sites known to be absent. This approach reduces the overestimation of ethylene content in such systems and is achieved by reducing the number of sites used to determine absolute ethylene content to:

[0210] E=0.5(Sββ+Sβγ+Sβδ+0.5(Sαβ+Sαγ))

[0211] Using this set of sites, the corresponding integral equation becomes:

[0212] E=0.5(I H +I G +0.5(I C +I D ))

[0213] The same symbols used in the article by Wang et al. {6} were used. The equations for absolute propylene content were not modified.

[0214] Calculate the mole percentage of comonomer incorporation from the mole fraction:

[0215] E[mol%]=100*fE

[0216] Calculate the weight percent of comonomer incorporation from the mole fraction:

[0217] E[weight%]=100*(fE*28.06) / ((fE*28.06)+((1-fE)*42.08))

[0218] bibliography:

[0219] 1)Busico,V.,Cipullo,R.,Prog.Polym.Sci.26(2001)443.

[0220] 2)Busico,V.,Cipullo,R.,Monaco,G.,Vacatello,M.,Segre,AL,Macromolecules 30(1997)6251.

[0221] 3)Zhou,Z.,Kuemmerle,R.,Qiu,X.,Redwine,D.,Cong,R.,Taha,A.,Baugh,D.Winniford,B.,J.Mag.Reson.187(2007)225.

[0222] 4)Busico,V.,Carbonniere,P.,Cipullo,R.,Pellecchia,R.,Severn,J.,Talarico,G.,Macromol.Rapid Commun.2007,28,1128.

[0223] 5)Resconi,L.,Cavallo,L.,Fait,A.,Piemontesi,F.,Chem.Rev.2000,100,1253.

[0224] 6)Wang,WJ.,Zhu,S.,Macromolecules 33(2000),1157.

[0225] 7)Cheng,HN,Macromolecules 17(1984),1950.

[0226] 8)Singh,G.,Kothari,A.,Gupta,V.,Polymer Testing 28 5(2009),475.

[0227] 9)Kakugo,M.,Naito,Y.,Mizunuma,K.,Miyatake,T.Macromolecules 15(1982)1150.

[0228] 10)Randall,J.Macromol.Sci.,Rev.Macromol.Chem.Phys.1989,C29,201.

[0229] 11) Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253.

[0230] Method II (composite materials)

[0231] ● Quantification of Styrene (S) and Butadiene (BD) Content

[0232] Use for 1 H and 13 Quantitative measurements were recorded in solution on a Bruker Avance III 400 NMR spectrometer operating at 400.15 and 100.62 MHz, respectively. 13 C{ 1 H} NMR spectroscopy. Nitrogen was used for all pneumatics and all spectra were 13 C-optimized 10 mm selective excitation probe was recorded at 125 °C. Approximately 200 mg of material was dissolved in 1,2-tetrachloroethane-d 2 (TCE-d 2 ), about 3 mg of BHT (CAS 128-37-0) was used as a stabilizer.

[0233] Standard single pulse excitation was used, using a 30 degree pulse, a relaxation delay of 3s and a sample rotation of 10Hz. Four virtual scans were used, and 16 transient values ​​were acquired for each spectrum. A total of 32k data points were collected for each FID with a dwell time of 60μs, which corresponds to a spectral window of approximately 20ppm. The FID was then zero-filled to 64k data points, and an exponential window function with 0.3Hz line broadening was applied.

[0234] Quantitative 1 H NMR spectra were processed, integrated and quantitative properties determined. All chemical shifts were internally referenced to the residual protonated solvent signal at 5.95 ppm. Characteristic signals corresponding to styrene, vinylidene and aliphatic bulk polyethylene and polypropylene were observed (AJ Brandolini, DD Hills, "NMR spectra of polymers and polymer additives", Marcel Deker Inc., 2000) and the content was calculated.

[0235] A characteristic signal resulting from the additional use of BHT as a stabilizer was observed. For BHT compensation, the integral of the signal at 4.8 ppm attributed to the -OH site of BHT was used, accounting for the number of reported nuclei per molecule.

[0236] BHT=IOH-BHT

[0237] Characteristic signals arising from styrene were observed and the aromatic signals between 7.4 ppm and 6.5 ppm assigned to aromatic protons were used. 芳族 ) to quantify the content, indicating the number of reported nuclei for each styrene. The effect of BHT must be compensated for in the integral area (I 芳族 )

[0238] PS=[I 芳族 -(2*BHT)] / 5

[0239]

[0240] At 5.6ppm and 5.3ppm (I 1,4 ) and between 5.3ppm and 5.0ppm (I 1,2 ) were observed between the vinylidene group on the 1,4-butadiene (R-CH=CH-R`) and the allyl group on the 1,2-butadiene (CH2=CH-RR`). Due to the overlap of the signals, it was necessary to use I 1,2 A proton pair I 1,4 Compensation was performed as described in AJ Brandolini, DD Hills, "NMR spectra of polymers and polymer additives", Marcel Deker Inc., 2000. The two unsaturated species were combined and quantified as butadiene:

[0241] BD=[I 1,2 +(I 1,4 -I 1,2 / 2)] / 2

[0242] Using bulk aliphatic (I 本体 The aliphatic content is quantified by integrating the signal from the aliphatic sites (CH and CH 2 ) and aliphatic sites from BHT. The bulk content is calculated based on the bulk integral and compensated for the aliphatic styrene signal and BHT, accounting for the reported number of nuclei for each bulk.

[0243] Ontology=[I 本体 -(21*BHT)-(3*S)] / 4

[0244] The mole fractions of styrene and vinylidene as butadiene in the polymer are calculated as:

[0245] fS=S / (S+BD+body)

[0246] fBD=BD / (S+BD+body)

[0247] The styrene and vinylidene content as butadiene in mole percent is calculated as:

[0248] S [mol%] = 100 * fS

[0249] BD [mol %] = 100 * fBD

[0250] The styrene and vinylidene content as butadiene in weight percent is calculated as:

[0251] S[weight%]=(100*fS*104.15) / [(fS*104.15)+(fBD*54.09)+((1-fS-fBD)*28.05)]

[0252] BD[wt%]=(100*fBD*54.09) / [(fS*104.15)+(fBD*54.09)+((1-fS-fBD)*28.05)]

[0253] ● Quantification of total C2, C3 and C4 content in composite materials

[0254] Use for 1 H and 13 Quantitative measurements were recorded in solution on a Bruker Avance Neo 400 NMR spectrometer operating at 400.15 and 100.62 MHz, respectively. 13 C{ 1 H} NMR spectroscopy. Nitrogen was used for all pneumatics and all spectra were 13 C optimized 10 mm extended temperature probe was recorded at 125 °C. About 200 mg of the material was mixed with about 3 mg of BHT (2,6-di-tert-butyl-4-methylphenol, CAS 128-37-0) and chromium (III) acetylacetonate (Cr(acac) 3 ) were dissolved in about 3 ml of 1,2-tetrachloroethane-d 2 (TCE-d 2 ) to obtain a 60 mM solution of the relaxing agent in a solvent as described in G. Singh, A. Kothari, V. Gupta, Polymer Testing 2009, 28(5), 475.

[0255] To ensure a homogeneous solution, the NMR tube was further heated in a rotary oven for at least 1 h after initial sample preparation in a heating block. After insertion into the magnet, the tube was rotated at 10 Hz.

[0256] Standard single pulse excitation without NOE was employed, using an optimized tip cone angle, 1 s recycle delay and a two-stage WALTZ16 decoupling scheme as described in Z. Zhou, R. Kuemmerle, X. Qiu, D. Redwine, R. Cong, A. Taha, D. Baugh, B. Winniford, J. Mag. Reson. 187 (2007) 225 and V. Busico, P. Carbonniere, R. Cipullo, C. Pellecchia, J. Severn, G. Talarico, Macromol. Rapid Commun. 2007, 28, 1128. A total of 6144 (6k) transients were collected for each spectrum.

[0257] Quantitative 13 C{ 1 H} NMR spectra were processed, integrated and the relevant quantitative properties were determined from the integrals. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm using the chemical shift of the solvent. This approach allows for comparable references even if this structural unit is not present.

[0258] Characteristic signals corresponding to various incorporations of ethylene as described in Cheng, HN, Macromolecules 1984, 17, 1950 and signals from SEBS as described in AJ Brandolini, DD Hills, "NMR spectra of polymers and polymer additives", Marcel Deker Inc., 2000 were observed.

[0259] As reported by L. Abis, Mackromol. Chem. 187, 1877-1886 (1986), a triad method comparable to that of ZN C2C3 copolymers was used to quantify the comonomer fraction, but C4 quantification was introduced and a compensation procedure for overlapping signals was established. Due to the complex C4 incorporation structure of the SEBS material, the only possibility to obtain the total amount of C4 in the blend was exploited by using the 1B2 sites between 11.80 ppm and 10.00 ppm, reflecting all existing C4 sequences.

[0260] In terms of C2 content, the total amount resulting from both the C2C3 and SEBS blend components alone can be quantified by using the methylene sequence at 30.0 ppm.

[0261] Attribution table 13C NMR spectroscopy

[0262] Chemical shift [ppm] Attribution Label 33.4 EPE(CH) A 31.3-30.7 PPE(CH)+Sgg+BHT B 30.4 Sgd(C2C3,C2C4) C 29.9 Sdd(C2C3, C2C4) D 29.6-28.2 PPP(CH) E 27.8-26.5 Sbd+2B2 F 25.2-24.3 Sbb G 12.0-10.0 EBE, EBB, BBB H 152 Quaternary Carbon (quart C) BHT BHT

[0263] Triad Equation

[0264] Triad sequence Signal / Equation PEP G PEE FH EEE D / 2+C / 4 PPP E PPE (B-6*BHT)-(((FH)-C) / 2) EPE A XBX H

[0265] After quantifying the mole fractions and normalizing, the amounts of C2, C3, and C4 can be calculated by summing the triads centered around E, P, and B:

[0266] The sum of triads = PEP + PEE + EE + PPP + PPE + EPE + XBX

[0267] f mole PEP = PEP / total mole of triads % PEP = f mole PEP*100

[0268] f mol PEE = PEE / total mole of triads % PEE = f mol PEE * 100

[0269] f moles of EEE = EEE / total mole of triads % EEE = f moles of EEE*100

[0270] f mole PPP = PPP / total mole of triads % PPP = f mole PPP*100

[0271] f mole PPE = PPE / total mole % PPE of triads = f mole PPE*100

[0272] f mole EPE = EPE / total mole of triads % EPE = f mole EPE*100

[0273] f moles XBX = XBX / total mole % of triads XBX = f moles XBX*100

[0274] C2 [mol%] = mol% PEP + mol% PEE + mol% EEE

[0275] C3 [mol%] = mol% PPP + mol% PPE + mol% EPE

[0276] C4 [mol %] = mol % XBX

[0277] The weight percent of comonomer is calculated from the mole percent in the usual manner:

[0278] Weight% C2 = 100*(C2[mol%]*28.06) / ((C2[mol%]*28.06)+(C3[mol%]*42.08)+C4[mol%]*56.11))

[0279] Weight% C3 = 100*(C3[mol%]*42.08) / ((C2[mol%]*28.06)+(C3[mol%]*42.08)+C4[mol%]*56.11))

[0280] Weight% C4 = 100*(C4[mol%]*56.11) / ((C2[mol%]*28.06)+(C3[mol%]*42.08)+C4[mol%]*56.11))

[0281] The total amount of C2, C3 and C4 was quantified by introducing the values ​​of styrene and vinylidene (as butadiene) calculated from 1H NMR:

[0282] wt%C2total=wt%C2*(100-(S[wt%]+BD[wt%])) / 100

[0283] wt%C3Total=wt%C3*(100-(S[wt%]+BD[wt%])) / 100

[0284] wt%C4Total=wt%C4*(100(S[wt%]+BD[wt%])) / 100

[0285] In the absence of C4, S or BD, the relevant equations collapse to the only observed structural features.

[0286] d) Differential Scanning Calorimetry (DSC) Analysis, Melting Temperature (Tm) and Crystallization Temperature (Tc):

[0287] The measurements were performed on 5 to 7 mg samples with a TA Instrument Q2000 Differential Scanning Calorimetry (DSC). The DSC was run according to ISO 11357 / Part 3 / Method C2 in a heating / cooling / heating cycle at a temperature range of -30°C to +225°C with a scan rate of 10°C / min.

[0288] The crystallization temperature and heat of crystallization (Hc) are determined from the cooling step, while the melting temperature and heat of fusion (H f ) is determined by the second heating step.

[0289] When a sample shows two or more melting temperatures and / or crystallization temperatures, only the main melting temperature (at the highest Hc) and the main crystallization temperature (at the highest Hf) are shown in the corresponding table. The difference between the melting temperature and the crystallization temperature (Tm-Tc) for the main melting temperature and the main crystallization temperature is given.

[0290] e) Xylene cold soluble matter (XCS) content

[0291] The amount of xylene solubles in polypropylene is determined according to ISO 16152 (first edition; 2005-07-01).

[0292] A weighed amount of sample is dissolved in hot xylene under reflux conditions at 135°C. The solution is then cooled under controlled conditions and kept at 25°C for 30 minutes to ensure controlled crystallization of the insoluble fraction. The insoluble fraction is then separated by filtration. The xylene is evaporated from the filtrate, leaving the soluble fraction as a residue. The percentage of this fraction is determined gravimetrically.

[0293]

[0294] in

[0295] m 0 is the mass of the sample test portion weighed in grams

[0296] m 1 is the mass of the residue in grams

[0297] v 0 is the original volume of the solvent taken

[0298] v 1 is the volume of the aliquot taken for the assay.

[0299] f) Glass transition temperature (Tg)

[0300] The glass transition temperature Tg is determined by dynamic mechanical analysis (DMTA) according to ISO 6721-7. The measurement is carried out in torsion mode on compression molded samples (40×10×1 mm3) at a heating rate of 2°C / min and a frequency of 1 Hz between -100°C and +150°C. Tg is determined from the curve of the loss angle (tan(δ)).

[0301] g) Intrinsic viscosity (IV)

[0302] Reduced viscosity (also called viscosity number) η red The intrinsic viscosity IV is determined according to ISO 1628-3: "Determination of the viscosity of polymers in dilute solution using capillary viscometers".

[0303] The relative viscosity of the diluted polymer solution and the pure solvent (decalin stabilized with 200 ppm of 2,6-bis(1,1-dimethylethyl)-4-methylphenol) at a concentration of 1 mg / ml was measured in an automatic capillary viscometer (Lauda PVS1) equipped with 4 Ubbelohde capillary tubes placed in a thermostatic bath filled with silicone oil. The bath temperature was maintained at 135° C. The sample was dissolved under continuous stirring until complete dissolution was achieved (usually within 90 min).

[0304] The elution time of the polymer solution and the pure solvent was measured several times until three consecutive readings differed by no more than 0.2 s (standard deviation).

[0305] The relative viscosity of the polymer solution is determined as the ratio of the mean elution times (in seconds) obtained for both the polymer solution and the solvent:

[0306]

[0307] Reduced viscosity (η red ) is calculated using the following equation:

[0308]

[0309] Where C is the polymer solution concentration at 135 °C:

[0310] and m is the polymer mass, V is the solvent volume, γ is the ratio of the solvent density at 20°C and 135°C (γ = ρ 20 / ρ 135 =1.107).

[0311] Calculation of intrinsic viscosity IV is performed from single concentration measurements by using the Schulz-Blaschke equation:

[0312]

[0313] where K is a coefficient that depends on polymer structure and concentration. To calculate an approximate value for IV, K = 0.27.

[0314] h) Molecular weight average, polydispersity (Mn, Mw, Mz, MWD) by GPC-analysis (GPC)

[0315] For GPC analysis, a universal calibration (according to ISO 16014-2:2003) calibration column set with 19 narrow MWD polystyrene (PS) standards in the range of 0.5 kg / mol to 11 500 kg / mol was used. The PS standards were dissolved at 160°C for 15 min, or alternatively at room temperature, at a concentration of 0.2 mg / ml for molecular weights above or equal to 899 kg / mol and 1 mg / ml for molecular weights below 899 kg / mol. The conversion of polystyrene peak molecular weight to polyethylene molecular weight was achieved by using the Mark Houwink equation and the following Mark Houwink constants:

[0316] K PS =19×10 -3 ml / g, α PS =0.655

[0317] K PE =39×10 -3 ml / g, α PE =0.725

[0318] A third-order polynomial fit was used to fit the calibration data.

[0319] The molecular weight averages (Mz, Mw and Mn), the molecular weight distribution (MWD) and its breadth described by the polydispersity index PDI = Mw / Mn (where Mn is the number average molecular weight and Mw is the weight average molecular weight) are determined using the following formula:

[0320]

[0321]

[0322] i) Flexural modulus

[0323] The flexural modulus was determined according to ISO 178 method A (3-point bending test) on 80 mm x 10 mm x 4 mm specimens. According to this standard, a test speed of 2 mm / min and a span length of 16 times the thickness were used. The test temperature was 23 ± 2 °C. Injection molding was performed according to ISO 19069-2, and a melt temperature of 230 °C was used for all materials, regardless of the material melt flow rate.

[0324] j) Simply supported beam notched impact strength

[0325] The Charpy notched impact strength is measured according to ISO 179-1 / 1eA on 80 mm x 10 mm x 4 mm notched specimens (specimens prepared according to ISO 179-1 / 1eA). The test temperature is 23 ± 2 ° C or -20 ± 2 ° C. Injection molding is carried out according to ISO19069-2, and for all materials, a melt temperature of 230 ° C is used, regardless of the material melt flow rate.

[0326] k) Rheological measurements

[0327] Dynamic shear measurement (sweep frequency measurement)

[0328] The characterization of the polymer composition or the melt of the polymer as given above or below by dynamic shear measurement complies with ISO standards 6721-1 and 6721-10. The measurements were carried out on an Anton Paar MCR501 stress-controlled rotational rheometer equipped with a 25 mm parallel plate geometry. The measurements were carried out on compression molded plates using a nitrogen atmosphere and setting the strain in the linear viscoelastic range. The oscillatory shear tests were carried out at 190° C., applied in a frequency range between 0.01 and 600 rad / s and with a gap of 1.3 mm.

[0329] In a dynamic shear experiment, the probe is subjected to uniform deformation under a sinusoidally varying shear strain or shear stress (strain-controlled mode and stress-controlled mode, respectively). In a controlled strain experiment, the probe is subjected to a sinusoidal strain that can be expressed by:

[0330] γ(t)=γ 0 sin(ωt) (1)

[0331] If the applied strain is within the linear viscoelastic range, the resulting sinusoidal stress response can be given by:

[0332] σ(t)=σ 0 sin(ωt+δ) (2)

[0333] in

[0334] σ 0 and γ 0 are the stress and strain amplitudes, respectively

[0335] ω is the angular frequency

[0336] δ is the phase shift (loss angle between the applied strain and the stress response)

[0337] t is the time

[0338] Dynamic test results are typically expressed with the aid of a number of different rheological functions, namely the shear storage modulus G', the shear loss modulus G", the complex shear modulus G*, the complex shear viscosity η*, the dynamic shear viscosity η', the out-of-phase component of the complex shear viscosity η" and the loss tangent tanδ, which can be expressed as follows:

[0339]

[0340] G * =G′+iG″[Pa] (5)

[0341] η * =η′-iη″[Pa·s] (6)

[0342]

[0343] The determination of the so-called shear thinning index, which is related to MWD and independent of Mw, is performed as described in Eq. 9.

[0344]

[0345] For example, SHI (2 / 100) Defined by dividing the value of the complex viscosity (in Pa·s) determined for a value of G* equal to 1 kPa by the value of the complex viscosity (in Pa·s) determined for a value of G* equal to 100 kPa.

[0346] The values ​​of storage modulus (G'), loss modulus (G"), complex modulus (G*) and complex viscosity (η*) were obtained as a function of frequency (ω).

[0347] So, for example, η* 300rad / s (eta* 300rad / s or eta 300 ) is used as an abbreviation for the complex viscosity at a frequency of 300 rad / s, η* 0.05rad / s (eta* 0.05rad / s or eta 0.05 ) is used as an abbreviation for the complex viscosity at a frequency of 0.05 rad / s.

[0348] The polydispersity index PI is defined by Equation 10.

[0349]

[0350] where ω COP is the cross-over angular frequency, determined as the angular frequency at which the storage modulus G' is equal to the loss modulus G".

[0351] These values ​​were determined with the aid of a one-point interpolation procedure defined by the Rheoplus software. In cases where a given G* value was not reached experimentally, it was determined with the aid of extrapolation, using the same procedure as before. In both cases (interpolation or extrapolation), the options "Interpolate y-values ​​to x-values ​​from parameter" and "logarithmic interpolation type" in Rheoplus were applied.

[0352] References:

[0353] [1]Rheological characterization of polyethylene fractions” Heino, EL, Lehtinen, A., Tanner J., J.,Neste Oy,Porvoo,Finland,Theor.Appl.Rheol.,Proc.Int.Congr.Rheol,11th(1992),1,360-362

[0354] [2]The influence of molecular structure on some rheologicalproperties of polyethylene", Heino, EL, Borealis Polymers Oy, Porvoo, Finland, Annual Transactions of the Nordic Rheology Society, 1995.).

[0355] [3] Definition of terms relating to the non-ultimate mechanical properties of polymers, Pure & Appl. Chem., Vol. 70, No. 3, pp. 701-754, 1998.

[0356] l) AC electrical breakdown strength (ACBD)

[0357] The AC breakdown test is carried out in accordance with CENELEC HD 605 5.4.15.3.4 for 6 / 10 kV cables. Therefore, the cable is cut into 6 test samples with an effective length of 10 meters (in addition to the ends). The samples are breakdown tested at ambient temperature by a 50 Hz AC step test according to the following procedure:

[0358] Start at 18kV and continue for 5 minutes

[0359] The voltage is increased in steps of 6 kV every 5 minutes until breakdown occurs

[0360] The calculation of the Weibull parameters for the data set of six breakdown values ​​(conductor stress, i.e., the electric field at the inner semiconductor layer) follows the least squares regression procedure described in IEC 62539 (2007). The Weibull α parameter in this document refers to the scale parameter of the Weibull distribution, i.e., the voltage at which the failure probability is 0.632. The Weibull β value refers to the shape parameter.

[0361] 2. Propylene copolymer composition

[0362] The following resins were used to prepare the propylene copolymer compositions in the examples:

[0363] a) Polymerization of heterophasic propylene copolymer powder A1

[0364] ·catalyst

[0365] The catalyst used in the polymerization process of the heterophasic propylene copolymer powder A1 is a Ziegler-Natta catalyst described in patent publications EP 491566, EP 591224 and EP 586390. Triethylaluminium (TEAL) was used as cocatalyst and dicyclopentyldimethoxysilane (D-donor) as donor.

[0366] Polymerization of heterophasic propylene copolymer powder

[0367] A liquid phase loop reactor and two gas phase reactors connected in series were used under the conditions shown in Table 1 in the presence of the polymerization catalyst described above at Borstar TM The present invention relates to a method for producing a heterophasic propylene copolymer powder A1 in a device. The first reaction zone is a loop reactor, and the second and third reaction zones are gas phase reactors. The matrix phase is polymerized in the loop reactor and the first gas phase reactor, and the elastomeric phase is polymerized in the second gas phase reactor. The catalyst as described above is fed into the prepolymerization reactor before the first reaction zone.

[0368] Table 1: Polymerization conditions of heterophasic propylene copolymer powders:

[0369] A1-Powder Prepolymerization TEAL / Ti ratio [mol / mol] 342 Donor / Ti ratio [mol / mol] 26.9 temperature [℃] 19.9 Dwell time [h] 0.16 Ring pipe temperature [℃] 70.0 pressure [barg] 55 Split ratio (loop + prepolymerization) [％] 33.7 H2 / C3 Ratio [mol / kmol] 5.5 C2 / C3 Ratio [mol / kmol] 16.7 MFR(230℃ / 2.16kg) [g / 10min] 6.5 C2 content (calculated) [weight%] 2.0 GPR 1 temperature [℃] 74.9 pressure [bar gauge] 21.0 Split ratio (GPR1) [％] 48.2 H2 / C3 Ratio [mol / kmol] 21.3 C2 / C3 Ratio [mol / kmol] 53.4 MFR(230℃ / 2.16kg) [g / 10min] 1.3 C2 content (calculated) [weight%] 6.5 GPR 2 temperature [℃] 79.99 pressure [bar gauge] 16.03 Split ratio (GPR2) [％] 18.2 C2 / C3 Ratio [mol / kmol] 401 H2 / C3 Ratio [mol / kmol] 69 MFR(230℃ / 2.16kg) [g / 10min] 1.2 XCS [weight%] 35.3 C2 (calculated content) [weight%] 10.5

[0370] b) Preparation of polypropylene composition

[0371] The heterophasic propylene copolymer powder A1 from the polymerization was compounded in a twin screw extruder together with different stabilizer packages to obtain the polypropylene compositions of reference examples RE1, RE2 and RE3.

[0372] For reference examples RE1 and RE3, an α-nucleating agent was added.

[0373] The composition of Example RE3 was visbroken to a melt flow rate MFR of 3.9 g / 10 min. 2 (230°C, 2.16 kg), as disclosed in the Examples section of WO 2017 / 198633.

[0374] An overview of the production of the polypropylene compositions of Examples RE1, RE2 and RE3 is shown in Table 2.

[0375] Table 2: Compounding of RE1, RE2 and RE3 in a twin screw extruder:

[0376] RE1 RE2 RE3 HECO-powder A1-Powder A1-Powder A1-Powder Visbreaking no no yes Stabilizer one pack (onepack) 1 [weight%] 0.2 0.2 - Stabilizer single pack 2 [weight%] - - 0.14 α-NA BNT [weight%] 2.0 - 2.0 Temperature range in extruder zone [℃] 140 to 300 140 to 300 150 to 280 Specific Energy Input (SEI) kWh / kg 0.157 0.155 0.146 Polymer melt temperature at the melt pump [℃] 242 244 231

[0377] The polypropylene compositions RE1, RE2 and RE3 show the properties as listed in Table 3 below.

[0378] Table 3: Properties of polypropylene compositions RE1, RE2 and RE3:

[0379] RE1 RE2 RE3 α-NA BNT no BNT <![CDATA[MFR 2 ]]> [g / 10min] 1.3 1.2 3.9 Flexural modulus [MPa] 370 335 378 Simply supported beam NIS (-20℃) <![CDATA[[kJ / m 2 ]]]> 6.5 6.3 4.2 Simply supported beam NIS (23℃) <![CDATA[[kJ / m 2 ]]]> 83.6 83.9 78.9 Tm [℃] 146.6 148.9 147.4 Tc [℃] 113.6 95.7 114.5 Tm-Tc [℃] 33.0 53.2 32.9 C2(Total) [weight%] 12.4 12.4 11.3 IV(Total) <![CDATA[[cm 3 / g]]]> 268 277 213 XCS fraction [weight%] 34.7 35.6 35.6 C2(XCS) [weight%] 26.3 26.1 24.5 IV(XCS) <![CDATA[[cm 3 / g]]]> 243 251 189 Mw(XCS) [g / mol] 285000 294500 215000 Mn(XCS) [g / mol] 45400 45650 48900 PDI(Mw / Mn)(XCS) [-] 6.3 6.4 4.4 XCI fraction [weight%] 65.3 64.4 64.4 C2(XCI) [weight%] 5.5 4.8 5.8 IV(XCI) <![CDATA[[cm 3 / g]]]> 275 286 216 Mw(XCI) [g / mol] 372500 384500 271000 Mn(XCI) [g / mol] 68100 69500 62000 PDI(Mw / Mn)(XCI) [-] 5.5 5.5 4.4 IV Ratio (XCI / XCS) [-] 1.13 1.14 1.14 Mw ratio (XCI / XCS) [-] 1.31 1.31 1.26

[0380] To produce the polymer compositions of inventive examples IE1 and IE2 and comparative example CE1, the compounded pellets of reference example RE2 were compounded with different additives in a Buss 100MDK L / D 11D co-kneader in a second compounding step. In addition, the compounded pellets of reference example RE1 were compounded with different additives in a Buss 100MDK L / D 11D co-kneader in a second compounding step to obtain the polypropylene compositions of example IE3 and comparative example CE2.

[0381] Table 4 shows an overview of the production of polypropylene compositions CE1, IE1, IE2, CE2 and IE3. Table 6 shows the properties of CE1, IE1, IE2, CE2 and IE3.

[0382] Table 4: Compounding of IE1 to IE3, CE1 and CE2 in a Bufield 100MDK L / D 11D co-kneader:

[0383] CE1 IE1 IE2 CE2 IE3 Granules RE2 RE2 RE2 RE1 RE1 SEBS-1 [weight%] - 10 - - - SEBS-2 [weight%] - - 10 - - SEPS [weight%] - - - - 10 Mixer zone temperature [℃] 117 to 211 119 to 213 132 to 210 128 to 211 Mixer RPM 146 146 150 150 Specific energy input SEI [kWh / kg] 0.28 0.31 0.29 0.24

[0384] Stabilizer Packages and Additives:

[0385] Stabilizer Single Pack 1 consists of 21.8 wt% of pentaerythritol tetrakis(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)-propionate (CAS-No. 6683-19-8), 43.6 wt% of tris(2,4-di-tert-butylphenyl) phosphite (CAS-No. 31570-04-4) and 34.6 wt% of calcium stearate (CAS-No. 1592-23-0), all of which are commercially available from multiple companies.

[0386] Stabilizer Single Pack 2 consists of 29 wt% of pentaerythritol tetrakis(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)-propionate (CAS-No. 6683-19-8), 58 wt% of tris(2,4-di-tert-butylphenyl) phosphite (CAS-No. 31570-04-4) and 13 wt% of magnesium oxide (CAS-No. 1309-48-4), all of which are commercially available from a number of companies.

[0387] α-Nucleation via BNT was achieved by adding 2 wt% of a propylene homopolymer having an MFR of 8.0 g / 10 min. 2 (230°C) and a melting temperature of 162°C, it is produced with Borealis Nucleation Technology (BNT) using a Ziegler-Natta type catalyst, contains a polymeric α-nucleating agent, and is distributed by Borealis AG (Austria).

[0388] SEPS is a styrene ethylene propylene styrene block copolymer with a polystyrene content of 18.5 to 22.5% by weight, a weight ratio of styrene to ethylene-propylene (S / EP) of 21 / 79, and a melt flow rate MFR 5 The hardness is 13g / 10min (ASTMD 1238, 230℃, 5kg), the Shore A hardness is 61 (ASTM D 2240) and the density is 0.90g / cm 3 (ASTM D 792), commercially available from Kraton Polymers as Kraton G 1730M. The properties are disclosed in the technical data sheet.

[0389] • SEBS-1 and SEBS-2 are styrene-ethylene-butylene-styrene block copolymers having the properties measured as in Table 5.

[0390] Table 5: Properties of SEBS-1 and SEBS-2

[0391] SEBS-1 SEBS-2 density <![CDATA[[kg / m 3 ]]]> 879.8 876.2 <![CDATA[MFR 2 ]]> [g / 10min] 6.5 3.1 Tm [℃] 83.8 65.2 Tc [℃] 49.4 11.5 Tm-Tc [℃] 34.4 53.7 Tg [℃] -36.1 -43.9 C2(Total) [weight%] 94.7 93.4 S(Total) [weight%] 4.5 4.8 BD(Total) [weight%] 0.9 1.7 <![CDATA[ω COP ]]> [1 / s] 115.6 62.9 SHI 1 / 100 [-] 5.06 2.29 PI [1 / s] 0.96 0.88

[0392] For the SEBS-1 and SEBS-2 components and the polypropylene compositions CE1, IE1, IE2, CE2 and IE3, the total content of styrene, ethylene (C2), 1-butene (C4) and propylene (C3) in the XCS and XCI fractions and the styrene, ethylene (C2), 1-butene (C4) and propylene (C3) contents have been determined by the above described method for quantifying styrene and vinylidene. 1 H NMR measurements and for the quantification of C2, C3 and C4 13 C NMR measurement was performed.

[0393] The contents of styrene, ethylene (C2), 1-butene (C4) and propylene (C3) and other properties of CE1, IE1, IE2, CE2 and IE3 are shown in Table 6.

[0394] Table 6: Properties of composite compositions of CE1, IE1, IE2, CE2 and IE3

[0395]

[0396] naNot applicable

[0397] PB = partial break, CB = complete break

[0398] It can be seen that the compositions IE1 to IE3 of the invention, in addition to having comparable crystallization and melting temperatures, show higher flexibility and impact properties compared to the comparative compositions CE1 and CE2. Thus, during the measurement of the Charpy impact strength at -20°C, the 10 measured samples of IE2 and IE3 show a borderline behavior of partial and complete fracture. In the above table, the average values ​​of partial fracture (PB) and complete fracture (CB) are listed as required in ISO 179-1.

[0399] 3.10kV cable production

[0400] The 10kV test cable is produced on the overhead line continuous vulcanization (CCV) type Maillefer test cable line.

[0401] The conductor of the cable core has a cross section of 50 mm 2 of stranded aluminum and has a cross section of 50 mm 2 The inner semiconductive layer was produced from the semiconductive composition SC2 or SC3 as described below and had a thickness of 1.0 mm. The insulating layer was produced from the compositions CE1 and CE2 and IE1 to IE3 described above and had a thickness of 3.4 mm. The outer semiconductive layer was produced from the semiconductive composition SC1 as described below and had a thickness of 1.0 mm.

[0402] The cable (i.e. cable core) is produced by extrusion through three heads. The size of the insulation extruder is 100 mm, the size of the conductor shield (inner semiconducting layer) extruder is 45 mm, and the size of the insulation shield (outer semiconducting layer) extruder is 60 mm. The line speed is 6.0 m / min.

[0403] The total length of the vulcanizing tube is 52.5 meters, consisting of a curing section followed by a cooling section. The curing section is filled with 10 bar of N 2 The 33-meter-long cooling section is filled with water at 20 to 25°C.

[0404] Then, the test cable was subjected to an AC breakdown test.

[0405] The semiconductive layer 1 (SC1) was prepared from the ready-to-use semiconductive composition Borlink LE7710, which is a non-crosslinkable polyethylene-based composition comprising carbon black, commercially available from Borealis AG.

[0406] Semiconductor layer 2 (SC2) was prepared from 66.5 wt% of the polypropylene-based composition of RE3 with 33.0 wt% of carbon black Printex Alpha (commercially available from Orion Engineered Carbons GmbH) and 0.5 wt% of maleic anhydride functionalized polypropylene Exxelor PO1020 (commercially available from Exxon Mobil).

[0407] Semiconductor layer 3 (SC3) was prepared from 66.5 wt% of the polypropylene-based composition of RE1 with 33.0 wt% of carbon black Printex Alpha (commercially available from Orion Engineered Carbons GmbH) and 0.5 wt% of maleic anhydride functionalized polypropylene Exxelor PO1020 (commercially available from Exxon Mobil).

[0408] Table 7 shows the electrical properties of 10 kV cables of Examples C1 to C5, wherein the inventive insulation layers IE1 to IE3 are compared with the comparative insulation layers CE1 and CE2.

[0409] Table 7: Electrical properties of 10kV cables from C1 to C5

[0410] C1 C2 C3 C4 C5 Insulation layer CE1 IE1 IE2 CE2 IE3 Inner semiconductor layer SC2 SC2 SC2 SC3 SC3 Outer semiconductor layer SC1 SC1 SC1 SC1 SC1 Weibull-α(scale)[kV / mm] 42.3 46.7 51.7 48.7 50.8 Weibull-beta (shape) 14.3 18.3 11.4 11.0 6.9

[0411] It can be seen that the cables comprising the inventive insulating layers IE1, IE2 and IE3 all show increased Weibull-α values ​​compared to the cables comprising the corresponding comparative insulating layers CE1 and CE2. The cable C2 comprising the inventive insulating layer IE1 even shows an increased Weibull-β value compared to the cable C1 comprising the comparative insulating layer CE1.

Claims

1. A cable comprising at least one layer comprising a polypropylene composition comprising (A) 80.0 to 99.0 wt%, preferably 82.5 to 97.2 wt%, most preferably 85.0 to 95.0 wt%, based on the total weight of the polypropylene composition, of a copolymer of propylene and comonomer units selected from ethylene and α-olefins having 4 to 12 carbon atoms, the copolymer having By quantitative 13 C{ 1 The total amount of the total amount of monomer units in the propylene-based copolymer (A) determined by H}NMR measurement is 10.0 to 16.0 wt%, preferably 11.0 to 15.0 wt%, most preferably 12.0 to 14.0 wt% of comonomer units; a melt flow rate MFR2, measured according to ISO 1133 at 230°C and 2.16 kg, of 0.5 to 5.0 g / 10 min, preferably 0.8 to 4.5 g / 10 min, still more preferably 1.0 to 4.3 g / 10 min and most preferably 1.2 to 4.0 g / 10 min; % xylene cold soluble (XCS) fraction, based on the total weight of the copolymer of propylene (A) and determined according to ISO 16152; and (B) 1.0 to 20.0 wt.%, preferably 2.5 to 17.5 wt.%, most preferably 5.0 to 15.0 wt.%, based on the total weight of the polypropylene composition, of a linear styrene block copolymer having a midblock containing ethylene, propylene and / or 1-butene sequences, the linear styrene block copolymer having a quantitative 13 C{ 1 The total content, measured by H}NMR measurement, is from 1.0 to 30.0 wt. %, preferably from 2.0 to 27.5 wt. %, most preferably from 3.0 to 25.0 wt. % of styrene units based on the total weight of the linear block copolymer (B).

2. Cable according to claim 1, wherein the copolymer of propylene (A) is a heterophasic copolymer of propylene comprising a matrix phase and an elastomeric phase dispersed in the matrix phase, the heterophasic copolymer of propylene preferably comprising two glass transition temperatures attributed to the matrix phase and the elastomeric phase, wherein the glass transition temperature Tg(matrix) attributed to the matrix phase is in the range of -1.0 to -15.0°C, preferably in the range of -2.5 to -12.5°C and most preferably in the range of -5.0 to -10.0°C, and / or the glass transition temperature Tg(EP) attributed to the elastomeric phase is in the range of -40.0 to -55.0°C, preferably in the range of -42.5 to -52.5°C and most preferably in the range of -45.0 to -50.0°C, wherein Tg(matrix) and Tg(EP) are determined by dynamic mechanical analysis.

3. The cable according to claim 1 or 2, wherein the xylene cold soluble (XCS) fraction of the copolymer of propylene (A) has a relative humidity of 10%, based on the total amount of monomer units in the xylene cold soluble (XCS) fraction and is quantitatively 13 C{ 1 H} NMR measurements are performed to determine an amount of 23.0 to 35.0 wt%, more preferably 23.5 to 32.5 wt% and most preferably 24.0 to 30.0 wt% of comonomer units, preferably ethylene, and / or 150 to 350 cm 3 / g, preferably 200 to 325cm 3 / g and most preferably 225 to 300 cm 3 / g of intrinsic viscosity measured in decalin according to ISO 1628-3.

4. The cable according to any one of claims 1 to 3, wherein the copolymer of propylene (A) has a total amount of 50.0 to 75.0 wt.-%, more preferably 55.0 to 72.5 wt.-%, still more preferably 57.5 to 70.0 wt.-% and most preferably 60.0 to 67.5 wt.-% of a fraction insoluble in cold xylene (XCI), based on the total weight of the copolymer of propylene (A) and determined according to ISO 16152, and wherein the fraction insoluble in cold xylene (XCI) preferably has a total amount of 50.0 to 75.0 wt.-%, more preferably 55.0 to 72.5 wt.-%, still more preferably 57.5 to 70.0 wt.-% and most preferably 60.0 to 67.5 wt.-% of a fraction insoluble in cold xylene (XCI), based on the total weight of the copolymer of propylene (A) and determined according to ISO 16152. 13 C{ 1 H} NMR measurements are performed to determine an amount of 3.0 to 9.0 wt%, preferably 4.0 to 8.5 wt% and most preferably 4.5 to 7.5 wt% of comonomer units, preferably ethylene, and / or preferably 185 to 350 cm 3 / g, more preferably 220 to 325cm 3 / g and most preferably 210 to 300 cm 3 / g of intrinsic viscosity measured in decalin according to ISO 1628-3.

5. The cable according to any one of claims 1 to 4, wherein the copolymer of propylene (A) has one or more of the following properties, preferably all of the following properties: 130 MPa to 400 MPa, more preferably 150 MPa to 390 MPa and most preferably 175 MPa to 380 Flexural modulus measured according to ISO 178 Method A in MPa; and / or 50 to 110 kJ / m 2 , more preferably 65 to 100 kJ / m 2 and most preferably 75 to 95 kJ / m 2 According to ISO Charpy notched impact strength at 23°C as measured by 179-1 / 1eA; and / or 5.0 to 10.0 kJ / m 2 , more preferably 5.5 to 9.0 kJ / m 2 and most preferably 6.0 to 8.0 kJ / m 2 The Charpy notched impact strength at -20°C is measured according to ISO179-1 / 1eA.

6. The cable according to any one of claims 1 to 5, wherein the linear block copolymer (B) is a styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) or a styrene-ethylene-propylene-styrene triblock copolymer (SEPS).

7. The cable according to any one of claims 1 to 6, wherein the linear block copolymer (B) is a styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) having one or more, preferably all of the following properties: ·By quantitative 13 C{ 1 % of ethylene-derived units based on the total amount of monomer units in the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) measured by H}NMR measurement; and / or ·By quantitative 13 C{ 1 % of units derived from styrene based on the total amount of monomer units in the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS) measured by H}NMR measurement; and / or ·By quantitative 13 C{ 1 % of units derived from butadiene, based on the total amount of monomer units in the styrene-ethylene-1-butene-styrene triblock copolymer (SEBS), measured by H}NMR measurement; and / or a melt flow rate MFR2 measured by ISO 1133 at 230°C and 2.16 kg of 1.0 to 10.0 g / 10 min, preferably 2.0 to 8.5 g / 10 min, most preferably 2.5 to 7.5 g / 10 min; and / or a melting temperature Tm as determined by differential scanning calorimetry of 50 to 100°C, preferably 55 to 95°C, most preferably 60 to 90°C; and / or a crystallization temperature Tc determined by differential scanning calorimetry of 5 to 50°C, more preferably 7 to 45°C, most preferably 10 to 40°C; and / or the difference between the melting temperature and the crystallization temperature Tm-Tc, preferably in the range of 20 to 65°C, preferably in the range of 25 to 60°C and most preferably in the range of 30 to 55°C; -30 to -50°C, preferably -32 to -47°C and most preferably -35 to -45°C, as determined by dynamic mechanical analysis; A shear thinning index (SHI) determined by dynamic shear measurement of from 1.0 to 7.5, more preferably from 1.2 to 6.5 and most preferably from 1.5 to 6.0 1 / 100 ; 0.2 to 1.5 seconds -1 , more preferably 0.4 to 1.3 s -1 and most preferably 0.6 to 1.1 s -1 polydispersity index PI; and / or 880 to 915 kg / m 3 , preferably 885 to 910 kg / m 3 , most preferably 890 to 905 kg / m 3 The density is determined according to ASTM D 792.

8. The cable according to any one of claims 1 to 6, wherein the linear block copolymer (B) is a styrene-ethylene-propylene-styrene triblock copolymer (SEPS) having one or more, preferably all of the following properties: Ability to use quantitative 13 C{ 1 A total content of styrene units of 10.0 to 30.0 wt. %, preferably 12.5 to 27.5 wt. %, most preferably 15.0 to 25.0 wt. %, based on the total weight of the linear block copolymer (B), measured by H}NMR measurement; and / or 10.0:9.0 to 30.0:70.0, preferably 12.5:87.5 to 27.5:72.5, most preferably 15.0:85.0 to 25.0:75.0 can be used quantitatively 13 C{ 1 The weight ratio of styrene to ethylene / propylene (S / EP) measured by H}NMR measurement; and / or a melt flow rate MFR5, measurable according to ASTM D 1238 at 230°C and 5 kg, of 1.0 to 25.0 g / 10 min, preferably 2.5 to 22.5 g / 10 min, most preferably 5.0 to 20.0 g / 10 min; and / or 880 to 915 kg / m 3 , preferably 885 to 910 kg / m 3 , most preferably 890 to 905 kg / m 3 A density that can be measured in accordance with ASTM D792; and / or • A Shore A hardness, measurable according to ASTM D 2240, of 40 to 75, preferably 45 to 70, most preferably 50 to 65.

9. The cable according to any one of claims 1 to 8, wherein the polypropylene composition has a total amount of 70.0 to 90.0 wt%, more preferably 72.5 to 87.5 wt% and most preferably 75.0 to 85.0 wt% of units derived from propylene; a total amount of 7.5 to 25.0 wt%, more preferably 10.0 to 22.5 wt% and most preferably 12.5 to 20.0 wt% of units derived from ethylene; a total amount of 0 to 12.5 wt.-%, more preferably 0 to 10.0 wt.-% and most preferably 0 to 7.5 wt.-% of units derived from 1-butene; a total amount of 00 to 0.50 wt%, more preferably 0 to 0.40 wt% and most preferably 0 to 0.30 wt% of units derived from butadiene; and a total amount of 0.1 to 10.0 wt. %, more preferably 0.2 to 7.5 wt. % and most preferably 0.3 to 5.0 wt. % of units derived from styrene, All amounts are based on the total molar amount of monomer units in the polypropylene composition and are quantitatively 13 C{ 1 H} NMR measurement was performed.

10. The cable according to any one of claims 1 to 9, wherein the polypropylene composition has a xylene cold soluble (XCS) fraction having a total amount of 47.5 to 75.0 wt%, more preferably 50.0 to 72.5 wt% and most preferably 52.5 to 70.0 wt% of units derived from propylene; a total amount of 20.0 to 40.0 wt%, more preferably 22.5 to 37.5 wt% and most preferably 25.0 to 35.0 wt% of units derived from ethylene; a total amount of 0 to 20.0 wt. %, more preferably 0 to 17.5 wt. % and most preferably 0 to 15.0 wt. % of units derived from 1-butene; a total amount of 0 to 1.00 wt. %, more preferably 0 to 0.80 wt. % and most preferably 0 to 0.60 wt. % of units derived from butadiene; and a total amount of 0.3 to 15.0 wt. %, more preferably 0.5 to 12.5 wt. % and most preferably 0.7 to 10.0 wt. % of units derived from styrene, All amounts are based on the total molar amount of monomer units in the xylene cold soluble (XCS) fraction and are quantitatively determined using 13 C{ 1 H} NMR measurement; and / or The polypropylene composition has a fraction insoluble in cold xylene (XCI), wherein the fraction insoluble in cold xylene (XCI) has a total amount of 85.0 to 99.0 wt%, more preferably 87.5 to 97.5 wt% and most preferably 90.0 to 96.0 wt% of units derived from propylene; a total amount of 0.7 to 10.0 wt%, more preferably 1.0 to 8.5 wt% and most preferably 2.5 to 7.5 wt% of units derived from ethylene; a total amount of 0 to 2.5 wt. %, more preferably 0 to 2.0 wt. % and most preferably 0 to 1.5 wt. % of units derived from 1-butene; a total amount of 0 to 0.20 wt. %, more preferably 0 to 0.15 wt. % and most preferably 0 to 0.10 wt. % of units derived from butadiene; and a total amount of 0 to 1.00 wt. %, more preferably 0 to 0.50 wt. % and most preferably 0 to 0.20 wt. % of units derived from styrene, All amounts are based on the total molar amount of monomer units in the cold xylene (XCI) insoluble fraction and are quantified using 13 C{ 1 H} NMR measurement was performed.

11. The cable according to any one of claims 1 to 10, wherein the polypropylene composition has one or more of the following properties, or all of the following properties: a melt flow rate, MFR2, measured according to ISO 1133 at 230°C and 2.16 kg, of 0.5 to 2.5 g / 10 min, preferably 0.8 to 2.2 g / 10 min, still more preferably 1.0 to 2.0 g / 10 min and most preferably 1.2 to 1.9 g / 10 min; and / or a melting temperature Tm determined by differential scanning calorimetry of 140 to 159°C, preferably 143 to 157°C and most preferably 145 to 153°C; and / or a crystallization temperature Tc determined by differential scanning calorimetry of 85 to 130°C, more preferably 87 to 128°C and most preferably 90 to 125°C; and / or the difference between the melting temperature and the crystallization temperature Tm-Tc preferably in the range of 20 to 65°C, preferably in the range of 25 to 60°C and most preferably in the range of 27 to 55°C; and / or a glass transition temperature Tg(matrix) attributable to the matrix phase determined by dynamic mechanical analysis in the range of -1.0°C to -15.0°C, preferably in the range of -2.5°C to -12.5°C and most preferably in the range of -4.0°C to -10.0°C; and / or a glass transition temperature Tg(EP) attributable to the elastomeric phase as determined by dynamic mechanical analysis of -35.0°C to -55.0°C, preferably -37.5°C to -52.5°C and most preferably -40.0°C to -50.0°C; and / or A shear thinning index (SHI) determined by dynamic shear measurement of 2.5 to 20.0, more preferably 5.0 to 17.5 and most preferably 7.5 to 15.0 1 / 100 ; and / or 1.0 to 4.0 seconds -1 , more preferably 1.5 to 3.5 s -1 and most preferably 2.0 to 3.0s -1 The polydispersity index PI is determined by dynamic shear measurement.

12. The cable according to any one of claims 1 to 11, wherein the polypropylene composition has one or more of the following properties, or all of the following properties: · a flexural modulus determined according to ISO 178 method A of 130 MPa to 350 MPa, more preferably 150 MPa to 340 MPa and most preferably 175 MPa to 325 MPa; and / or 50 to 110 kJ / m 2 , more preferably 65 to 100 kJ / m 2 and most preferably 70 to 95 kJ / m 2 Charpy notched impact strength at 23°C, measured in accordance with ISO 179-1 / 1eA; and / or 7.5 to 80.0 kJ / m 2 , more preferably 8.5 to 75.0 kJ / m 2 and most preferably 9.0 to 70.0 kJ / m 2 The Charpy notched impact strength at -20°C is measured according to ISO179-1 / 1eA.

13. The cable according to any one of claims 1 to 12, wherein the polypropylene composition is free of dielectric fluid.

14. The cable according to any one of claims 1 to 13, being a medium voltage cable or a high voltage cable, comprising an insulation layer comprising the polypropylene composition.

15. The cable according to claim 14, having a Weibull alpha value measured on a 10 kV cable according to CENELEC HD 605 5.4.15.3.4 for 6 / 10 kV cables of 35.0 to 65.0 kV / mm, preferably 37.5 to 65.0 kV / mm and most preferably 40.0 to 65.0 kV / mm and / or a Weibull beta value measured on a 10 kV cable according to CENELEC HD 605 5.4.15.3.4 for 6 / 10 kV cables of 5.0 to 250.0, preferably 5.5 to 250.0 and most preferably 6.0 to 50.0.

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