Cable and polymer composition

[0001] The present invention is directed to a polymer composition comprising a polymer and optionally a filler for use in making a layer on wires, to a conduit surrounded by at least one layer containing the polymer composition, as well as to a process for making the conduit.

Background Art [0002] A typical electrical wire usually includes a conductor, which is surrounded by one or more layers, depending on the use of the wire. For example, the power cord has several layers of polymeric materials including the inner semi-conductive layer, then the insulation layer, and then the outer semi-conducting layer. In addition to these layers, it is possible to add one or more sub layers. The outer protective layer is determined, e.g. as a covering layer. Any of the layers can be crosslinked using methods known in the art.

[0003] Safety, reliability and long life are the most important factors that are requirements for applications in ducts. As the sheath layer provides cable protection, it plays an important role in ensuring the operation of the system.

[0004] Low density polyethylene (LDPE), which is e.g. produced in high pressure processes, is widely used in all types of pipe layers, including sheath layers. Its main disadvantage are unsatisfactory mechanical properties that do not meet the requirements for the cover layers.

[0005] Linear low density polyethylene (LLDPE) is known, among others as a material for covering layers. However, and usually, also LLDPE is not entirely satisfactory in terms of the mechanical properties placed on polymers in the duct layer, such as the sheath layer.

[0006] The mechanical properties of the layer can be improved by increasing the density of polyethylene. High density polyethylene (HDPE) must provide increased mechanical strength of the cable layer, such as abrasion resistance. However, HDPE has a drawback, limited resistance to stress cracking, expressed e.g. as ESCR, and reduced flexibility required, among others for the cover layer.

[0007] Multimodal polyethylene (PE) provides one way to adjust the properties of the polymer. In order to allow the use of multi-modal PE as a covering layer, the property balance should be optimized, among others regarding mechanical properties such as strength, stress cracking and flexibility, and workability. Different solutions have already been provided, but there is still a need for alternative or improved ownership balances.

[0008] Furthermore, e.g. a unilateral catalyst (SSC) provides controlled incorporation of comonomers, which then provide ways to adjust the polymer. However, the machinability of PE based on SS catalyst is often problematic.

[0009] There is a continuing need in the area of ​​polymers to find a polyol that would be suitable to meet the needs in polymer applications, especially in W&C applications where the conduit material must meet the requirements and strict guidelines of the authorities.

Objects of the invention [0010] One of the objectives of the present invention is to provide an alternative polymer composition that has advantageous properties for use as a conduit layer, and particularly has excellent mechanical properties in combination with favorable machinability for use as a cover layer. In addition, a process for preparing the polymer composition was provided.

[0011] Another object of the invention is to provide a conductor comprising a conductor surrounded by one or more layers, at least one of which comprises a polyethylene polymer composition having favorable mechanical properties. Preferably, the sheath layer comprises a polymer composition. In addition, a process for producing said conduit has been provided.

[0012] Furthermore, the use of the polymer composition according to the invention in the conduit layer has been provided.

Drawings [0013] Figures 1-9 illustrate SCB (MW) profiles determined for polymer components 1-3, polymer compositions according to the invention 1-3 and references 1-2, in this order. Curves in the drawings: - MWD, □ SCB (MW) in a centered area of ​​90% by weight MWD. Figure 10 is an example illustrating the determination of a centered area of ​​90 wt. for the polymer composition according to the invention 1. Curves in the drawings: - MWD, - - MWD cumulative normalized, Δ MWD cumulative normalized, centered area 90% by weight.

Detailed description of the invention [0014] Accordingly, the invention is directed to a polymer composition comprising a polymer component and an optional carbon black (CB) component in which the polymer composition has a modulus of elasticity lower than 390 MPa, determined according to ISO 178 using a test sample (the compressed sample has been prepared from pellets of polymer composition, dimensions 80 x 10 x 4.0 mm, length x width x thickness), and deformation at break (%) 700% or higher, determined according to ISO 527-1: 1993 using a test sample prepared according to IS0527-2: 1993 5A (compressed sample prepared from pellets of the polymer composition).

[0015] It has been proved that the above-defined balance of properties of the polymer composition is excellent in polymer applications where good mechanical properties are required, without sacrificing flexibility, i.e. in applications such as in cable layers.

[0016] The polymer composition of the invention is abbreviated below as "Polymer composition", the polymer component as "Polymer" and carbon black as "CB". It is understood here that the term polymer component (Polymer) may contain one polymer or a mixture of two or more polymer components that are different.

[0017] Due to the highly favorable balance between the modulus of elasticity and mechanical properties, the polymer composition is a suitable material for the layer (s) of the conduit, preferably a sheath layer that provides a protective covering for the conduits.

[0018] The invention is also directed to the use of a polymer composition for the production of a product, preferably at least one layer of a conduit and conductor comprising a conductor coated with one or more layers, at least one of which comprises a polymer composition as described above and below, and in the claims .

[0019] The term "conductor" means here and below that the conductor includes one or more wire. Furthermore, the conductor may contain one or more such conductors. Preferably the conductor is an electrical conductor.

[0020] "Wire" includes all types of wires and wires used in wires and wires (W&C) applications. [0021] The conduit may comprise two or more layers comprising a polymer composition. Said at least one layer of the duct containing the polymer composition is preferably a sheath layer.

[0022] Preferably, the polymer component of the polymer composition contains short chain branches (SCBs), which are typically defined as the number of CH3 end groups per 1000 carbon atoms (CH3 groups per 1000 carbon atoms, or CH3 / 1000 for short). Here, SCB is expressed as the SCB distribution curve as a function of molecular weight and by determining the arithmetic mean of the X value, including ± deviation, of methyl groups per 1000 total carbon atoms in the central 90% by weight of the total molecular weight distribution area (MWD). "Distribution of short chain branches as a function of molecular weight" is also abbreviated here as "SCB curve (MW)" and "methyl groups per 1000 total carbon atoms" as "CH3 / TC". Accordingly, the polymer component of the polymer composition having an SCB (MW) curve with X ± 5 CH3 / 1000TC, preferably X ± 4 CH3 / 1000TC, more preferably X ± 3 CH3 / 1000TC, where X is the arithmetic mean in the central 90% by weight of the total decomposition area molecular weight (MWD) as determined according to the SCB determination method as described in "Determination Methods".

[0023] A deviation of ± 5, preferably ± 4, more preferably ± 3, around the arithmetic mean X indicates that the SCB (MW) curve of the polymer component is linear. Without being limited to any theory, it is believed that the SCB distribution curve and its linearity as defined above and below or in the claims gives a great contribution to the excellent balance of mechanical properties of the polymer composition.

[0024] More preferably, said arithmetic average X of the SCB (MW) curve of the polymer component is 17 in the middle 90% by weight of the total molecular weight distribution area (MWD), and the polymer component of the polymer composition has SCB (MW) 17 ± 5 CH3 / 1000TC , preferably 17 ± 4

CH3 / 1000TC, more preferably 17 ± 3 CH3 / 1000TC, in the middle 90% by weight of the total molecular weight distribution area (MWD), if determined in accordance with the SCB determination method described in "Determination Methods".

[0025] The polymer composition preferably has a modulus of lower than 350 MPa, preferably lower than 330 MPa, more preferably from 320 to 150 MPa, even more preferably from 310 to 200 MPa.

[0026] The polymer composition preferably has a stress stress of at least 20 MPa, preferably at least 23 MPa, more preferably at least 24 MPa, if determined according to ISO 527-1: 1993 using a sample prepared according to ISO527-2: 1993 5A ( compressed sample prepared from pellets of polymer composition). The upper limit of stress at break is not specified, but it can fluctuate and can be, e.g. up to 40 MPa.

Furthermore, further mechanical properties of the polymer composition, e.g. strain at break (%) is preferably 750% or more if determined according to ISO 5271: 1993 using a sample prepared according to ISO527-2 1993 5A (pressed sample prepared from pellets polymer composition). The upper limit for deformation at break is not specified, but it can vary and can be up to 1000%.

[0028] Even more preferably, the MFR2 of the polymer composition is lower than 2.0 g / 10 min, preferably lower than 1.4 g / 10 min, more preferably from 0.05 to 1.2 g / 10 min, more preferably from 0.1 to 1.0 g / 10 min, more preferably 0.15 to 0.8 g / 10 min, even more preferably 0.15 to 0.5 g / 10 min, if measured according to ISO 1133 ( 190 ° C, with a load of 2.16). In some embodiments, the preferred MFR2 range of the polymer composition is from 0.2 to 0.4 g / 10 min.

[0029] Also preferably, the polymer composition has very good stress cracking properties, which are expressed as environmental stress cracking properties (ESCR), namely ESCR at least 1500 hours, preferably at least 2000 hours, more preferably at least 2500 hours, if designated according to IEC 60811-4-1: 2004, the procedure in Chapter 8, "Resistance to environmental stress cracking", Procedure B, 10% by volume solution of Igepal CO-630 in water.

[0030] The polymer composition preferably also has very good rheological properties, as indicated herein by the shear thinning index (SHI), namely the shear thinning index, SHl2,7 / 210, at least 45, preferably at least 50, preferably at least 60, preferably at least

70, preferably at least 75, more preferably from 75 to 400, more preferably from 75 to 300, more preferably from 75 to 200, even more preferably from 80 to 100, even more preferably from 80 to 95, if measured as described in " Determination methods ". The above SHI values ​​indicate the beneficial property of the machinability of the polymer composition, which also has a beneficial effect on the very good surface properties of the final product, such as the duct layer.

[0031] The density of the polymer composition is preferably more than 890 kg / m³, preferably from 900 to 950 kg / m³, preferably from 910 to 940 kg / m³, more preferably from 915 to 938 kg / m³, more preferably from 920 to 937 kg / m³.

[0032] The polymer composition preferably contains at least 50 wt.% (Wt.%) Polymer, preferably at least 70 wt.%, Preferably at least 75 wt.%, Preferably at least 80 wt.%, Preferably at least 80 wt.%. at least 85% by weight, more preferably at least 90% by weight, based on the total amount of the polymer composition.

[0033] It is understood above and below or in the claims that the weight% ratios components of the polymer composition, if given "with respect to the total amount of polymer composition", are selected such that the total amount of polymer composition is 100 wt.

"CB Component" means carbon black or masterbatch (CBMB), which is a mixture of carbon black together with a polymer carrier. The carbon black content of the polymer composition is defined above and below as both the amount of carbon black and the amount of CBMB, relative to the total amount polymer composition or with respect to the combined amounts of polymer component and CB or CBMB, respectively, when specified in the context. Accordingly, if CBMB is used, it is then mixed preferably below the given amount of polymer of the polymer composition to form a mixture thereof.

[0035] In addition, the CB component is preferably present in the polymer composition. Preferably, the polymer composition contains up to 20 wt.%, Preferably from 0.1 to 15 wt.%, More preferably from 0.2 to 10 wt.%, More preferably from 0.3 to 6 wt.%, Carbon black ("pure "CB), based on the total amount of polymer composition, preferably based on the combined amounts of polymer component and CB.

[0036] CB is preferably in the form of CBMB. The polymer composition then contains up to 50 wt.%, Preferably up to 30 wt.%, Preferably up to 25 wt. , preferably from 1 to 20% by weight, more preferably from 3 to 15% by weight, more preferably from 4 to 10% by weight, CBMB, based on the total amount of the polymer composition, preferably based on the combined amounts of the polymer component and CBMB . The polymeric carrier is a component of CBMB.

[0037] The polymer composition is preferably a polyethylene composition, wherein the polymer comprises at least one polyethylene component. The term "polyethylene" means an ethylene homopolymer or copolymer of ethylene with one or more comonomers. [0038] More preferably, the polymer of the preferred polyethylene composition comprises a mixture of at least two polyethylene components.

[0039] According to a preferred embodiment of the polymer composition, the polymer of the polymer composition is a mixture of at least two polyethylene components (1) and (2) which are different, more preferably the polymer composition comprises (1) at least 30 wt. a polyethylene component which is an ethylene homopolymer or an ethylene copolymer that contains one or more comonomers, (2) less than 70 wt. a polyethylene component which is a homopolymer of ethylene olefins or a copolymer of ethylene which contains one or more comonomers, and (3) to 20 wt.%, preferably from 0.1 to 15 wt.%, more preferably from 0.2 to 10 wt.% , more preferably from 0.3 to 6 wt.%, additional carbon black, based on the total amount of polymer composition. CB is preferably introduced as CBMB. The amount of CBMB is up to 50% by weight, preferably from 1 to 20% by weight, more preferably from 3 to 15% by weight, more preferably from 4 to 10% by weight, CBMB, based on the total amount of the polymer composition, preferably in with respect to the combined amounts of polymer component (1), polymer component (2) and CBMB.

[0040] It is well known that "comonomer" refers to a copolymerizable comonomer unit.

[0041] More preferably, the polymer component (1) is long chain branching polyethylene, more preferably low density polyethylene (LDPE), and the polymer component (2) is linear low density polyethylene (LLDPE).

[0042] Long chain branches means here a polymer chain with branches of more than 12 carbon atoms present in the main chain and / or other polymer branches. For example, an LDPE polymer has long chain branches.

[0043] The polymer components (1) and (2) can be mechanically mixed by conventional methods, e.g. in a mixer or extruder, or both, or by in-situ mixing, e.g. during polymerization of the components. Mechanical mixing and insite are well known in the art. Preferably, the mixture of the polymer composition is mechanically mixed. The additional component CB (3) is preferably added to other components in the form of CBMB in a manner well known in the art.

[0044] The final selection of polymer components and their weight ratios is within the skill of a qualified person and can be adapted with respect to the properties of individual polymer components to meet the new and revealing balance of properties of claim 1, or preferably the subsequent subgroups or further embodiments of the invention.

[0045] Each of the polymer components (1) and (2) and the additional and preferred polymer carrier CBMB (3) preferably brings a favorable value to the SCB decomposition. The ingredients can be selected so that a favorable SCB distribution of the polymer composition is achieved.

[0046] More preferably the polymer composition comprises, (1) at least 40 wt.%, Preferably at least 45 wt.%, More preferably at least 50 wt.%, More preferably from 53 to 70 wt.%, Of an LDPE polymer selected from LDPE homopolymer or LDPE ethylene copolymer with one or more comonomers;

(2) less than 60 wt.%, More preferably less than 55 wt.%, More preferably less than 50 wt.%, More preferably less than 43 wt.%, More preferably from 40 to 30 wt.%, LLDPE polymer, which is preferably a multimodal low density ethylene linear copolymer with one or more olefin comonomer, preferably with C3-C20 alpha olefin comonomer, and (3) to 20 wt.%, preferably from 0.1 to 15 wt.%, more preferably from 0.2 to 10% by weight, more preferably from 0.3 to 6 wt.%, additional carbon black based on the total amount of polymer composition, preferably based on the amount of polymer component (1), polymer component (2) and additional component CB (3). The CB component is preferably present and preferably incorporated into the composition in the form of CBMB as defined above.

[0047] In this embodiment, the polymer composition preferably comprises the polymer component (1) and the polymer component (2) in the amounts given above and the CBMB component (3) from 1 to 20% by weight, preferably from 3 to 15% by weight, more preferably from 4 to 10% by weight, based on the total amount of polymer composition, preferably based on the combined amounts of polymer component (1), polymer component (2) and additional component CBMB (3).

[0048] Again, it is understood above and below or in the claims that the wt. components of the polymer composition when the given "with respect to the combined amounts of polymer component (1), polymer component (2) and additional component CBMB (3)" are selected such that the total combined amount of components (1) to (3) is 100% by weight

[0049] The multimodal linear ethylene low density copolymer refers here to the "multimodal LLDPE copolymer". Multimodality LLDPE copolymer, unless otherwise stated, means multimodality with respect to the molecular weight distribution (MWD) of the LLDPE copolymer component (2).

The multimodality (2) LLDPE copolymer also provides a favorable balance of mechanical properties of the invention.

[0050] The polymer composition of the invention may also contain components such as polymer components and / or additives, preferably additives such as antioxidants, crosslinkers, free radical generating agents, e.g. organic peroxides, burn retarders (SR), crosslinking accelerators, stabilizers, processing aids, flame retardant additive, drainage additive, acid purifier, inorganic fillers and voltage stabilizers as are known in the field of polymers.

[0051] Preferably the polymer composition comprises a polymer, preferably a mixture of the polymer component (1) and the polymer component (2) as the only polymer component. This means that the polymer composition does not contain more polymer components, but the polymer and the mixture of polymer components (1) and (2) as the only polymer component. However, it must be understood here that the polymer composition may also contain components other than polymer components, such as additional CB (3) components and / or additives, which may optionally be added to the mixture with the carrier polymer, e.g. in a so-called main reactor . Accordingly, the polymer composition may contain, and preferably comprises, a CBMB carrier polymer, but the primary reactor carrier polymer is not understood in the sense of "polymer" or "polymeric component".

[0052] The polymer composition of the invention may be crosslinkable, e.g. for use in crosslinkable wires that are then crosslinked. Cross-linking can be the result of, among others radical reaction using radiation or free radical generating agents. Examples of such free radical generating agents are peroxides including inorganic and organic peroxides. Then, crosslinking by functional groups, e.g. by hydrolysis of hydrolysable silane groups that are attached (both by copolymerization and grafting) to the polymer and then recognized as forming silanol groups using a silanol condensation catalyst.

[0053] Next, the beneficial properties, subgroups as well as embodiments of the polymer composition and conduit given above or below are given in a general manner, meaning that they are combined in any combination defined subsequently as preferred embodiments of the invention.

[0054] The polymer composition comprises a polymer, preferably a mixture of a polymer component (1) and a polymer component (2), and in addition a component CB (3) as defined above. Components (1) to (3) are then described below in the context of ownership and preferred subgroups or incarnation properties. A detailed description of the ingredients is used in both: the polymer composition and the conduit. As the evidence shows, the beneficial properties, subgroups and incarnations of components 1 to 3 are given in a general manner, which means that they can be combined in any way to produce a preferred embodiment of the invention. Unless specified herein, if a method for measuring preferred properties as defined above or below for a polymer composition, polymer, CB and conduit are described later in "Determination Methods".

Polymer component (1) [0055] The polymer component (1) is preferably an olefin homopolymer or copolymer of one or more comonomers, more preferably polyethylene, preferably polyethylene, which can be produced in a high pressure process or a low pressure process. More preferably, the polymer component (1) is polyethylene which has long chain branches, more preferably it is low density polyethylene (LDPE). The importance of the LDPE polymer is well known and documented in the literature.

[0056] The polymer component (1) is preferably an LDPE polymer produced by a high pressure process. More preferably, the LDPE polymer is selected from an LDPE homopolymer or an LDPE ethylene copolymer of one or more comonomers.

[0057] In the case of an ethylene LDPE copolymer, one or more comonomers may be selected from non-polar comonomers or polar comonomers or from a mixture of any comonomers from this group as well known.

[0058] As a polar comonomer, comonomers containing hydroxyl groups, alkoxy groups, carbonyl groups, carboxyl groups, ether groups or ester groups or a mixture thereof can be used. More preferably, comonomers, if present, contain carboxyl groups and / or ester groups are used in said polar comonomers. Still more preferably, the polar comonomer of the LDPE ethylene copolymer is selected from the group of acrylates, methacrylates or acetates or mixtures thereof. If present, said ethylene LDPE copolymer, the polar comonomer is preferably selected from the group of alkyl acrylates, alkyl methacrylates or vinyl acetate or mixtures thereof. Then preferably, said polar comonomer is selected from C1- to C6-alkyl acrylates, C1- to C6-alkyl methacrylates or vinyl acetate. Still more preferably, said LDPE ethylene copolymer is an ethylene copolymer of a C1 to C4 alkyl acrylate, such as methyl, ethyl, propyl or butyl acrylate or vinyl acetate or mixtures of any of these.

[0059] Non-polar comonomers herein are comonomers that do not contain hydroxyl groups, alkoxy groups, carbonyl groups, carboxyl groups, ether groups or ester groups. One group of preferably non-polar comonomers includes, preferably consists of, monounsaturated (= one double bond) comonomers, preferably olefins, preferably alpha-olefins, more preferably C3 to C10 alpha-olefins such as propylene, 1-butene, 1-hexene, 4- methyl-1-pentene, styrene, 1-octene, 1-nonene; polyunsaturated (= more than one double bond) comonomers; silane group containing comonomers; or a mixture of any of them. The polymer component (1), preferably the LDPE polymer may contain a comonomer containing hydrolysable silane groups or may be grafted with compounds containing hydrolysable silane groups in a manner known in the art. This may be crucial if, for example, polymer crosslinking using silane technology is desired for the end use.

[0060] The LDPE polymer may optionally have unsaturation, which is preferably derived from vinyl groups, vinylidene groups and trans-vinyl groups. The unsaturation can be provided by a polymerization monomer, preferably ethylene, in the presence of a chain transfer agent (CTA), which it introduces e.g. vinyl groups into the polymer chain, or in the presence of one or more polyunsaturated co-monomers as mentioned above, and optionally in the presence of a chain transfer agent which introduces, e.g., vinyl groups into the polymer chain. Unsaturated polyolefins and preferably unsaturated polymers

LDPE are well known. The level of unsaturation can be changed by choosing polymerization conditions such as highest temperature and pressure as is known in the art.

[0061] It is well known that e.g. propylene can be used as a comonomer or chain transfer agent (CTA), or both, with which the total number of CC double bonds can be increased, preferably also the total amount of vinyl groups. Here, if the compound can act as a comonomer and is used as CTA to provide double bonds, such as polypropylene, such a copolymerizable comonomer is not included in the comonomer content.

[0062] Preferably, the density of the polymer component (1), preferably the LDPE polymer, is higher than 860 kg / m³. Preferably, the density of the polymer component (1), preferably the LDPE polymer is not higher than 960 kg / m³, more preferably from 910 to 945 kg / m³, more preferably from 920 to 945 kg / m³.

[0063] MFR2 (ISO 1133, 190 ° C at 2.16 charge) of the polymer component (1) preferably the LDPE polymer is preferably from 0.01 to 50 g / 10min, preferably from 0.1 to 20 g / 10min, preferably less than 10 g / 10 min, preferably less than 5 g / 10 min, more preferably less than 3 g / 10 min, more preferably less than 2.0 g / 10 min, more preferably from 0.1 to 1.5 g / 10 min, preferably 0.5 to 1.4 g / 10 min, more preferably 0.7 to 1.2 g / 10 min.

[0064] Preferably, the polymer component (1) is an LDPE homopolymer or LDPE copolymer as described above, which may be optionally unsaturated. If the LDPE homopolymer is unsaturated, the unsaturation is provided by a chain transfer agent (CTA) and / or by polymerization conditions. If the LDPE copolymer is unsaturated, the unsaturation can be provided by the following methods: by a chain transfer agent (CTA), by one or more polyunsaturated comonomer and / or by polymerization conditions. In the case of an LDPE copolymer, it is preferred that the unsaturated copolymer of LDPE ethylene with at least one polyunsaturated comonomer, preferably diene, and optionally other comonomers, such as a polar comonomer, which is preferably comonomer acrylate or acetate; more preferably an unsaturated copolymer of LDPE ethylene with a polyunsaturated comonomer, preferably diene.

[0065] LDPE homo and copolymers (1) suitable for the present invention are commercially available or can be produced similarly or according to known polymerization processes. The high pressure (HP) process is the preferred process for producing polyolefin polymer compositions, preferably low density polyethylene (LDPE) selected from an LDPE homopolymer or an LDPE ethylene copolymer with one or more comonomers. Accordingly, the polyolefins of the invention are preferably produced in a high pressure process by free radical-initiated polymerization in the presence of initiators (referred to as high pressure radical polymerization).

[0066] High pressure polymerization (HP) and adjustment of process conditions to further adapt other properties of polyolefins depending on the desired end use are well known and described in the literature and can be directly used by a person skilled in the art. A suitable temperature value ranges from 400 ° C, preferably from 80 to 350 ° C, and a pressure from 70 MPa, preferably 100 to 400 MPa, more preferably from 100 to 350 MPa. The pressure can be measured at least in a compressed state and downstream of the tube. The temperature can be measured at several points in all steps. [0067] After separation, the resulting polymer is usually in the form of a molten polymer, which is normally mixed and pelleted in a pellet squeezer connected to the HP reactor system. Optionally, additives such as antioxidants can be added to the mixer in a manner known in the art to obtain a polymer composition.

[0068] The exact details of the ethylene (co) polymer production in the process of high pressure radical polymerization can be found, among others in Encyclopedia of Polymer Science and Engineering, Vol. 6 (1986), pp. 383-410 and Encyclopedia of Materials: Science and Technology, 2001 Elsevier Science Ltd .: "Polyethylene: High-pressure, R. Klimesch, D. Littmann and F.-O. Mahling pp. 7181-7184. WO 9308222 describes high pressure radical polymerization of ethylene with a polyunsaturated monomer, such as α, ω-alkadienes, to increase the unsaturation of ethylene copolymer.

Polymer component (2) [0069] The polymer component (2) is preferably an olefin homopolymer or copolymer which contains one or more comonomer, more preferably polyethylene, preferably linear low density polyethylene (LLDPE). Preferably, the polymer component (2) is a multimodal linear copolymer with low density ethylene and one or more olefin comonomer, e.g. a multimodal LLDPE copolymer.

[0070] The term "multimodal" here means, unless otherwise stated, multimodality with respect to molecular weight distribution and also includes bimodal polymers. Typically, polyethylene containing at least two polyethylene fractions that have been produced under different polymerization conditions to obtain different (weight average) molecular weights and molecular weight distributions for fractions, is referred to as "multimodal". The prefix "multi" refers to the amount of different polymer fractions present in a polymer. Hence, for example, a multimodal polymer includes so-called "bimodal" polymers containing two fractions. Form of molecular weight distribution curve, e.g., plotting the weight of the polymer fraction as a function of molecular weight for a multimodal polymer it will show two or more maxima or, conventionally, extension, compared to individual fraction curves. For example, if the polymer is produced in a multi-stage process, in cascade reactors using different reaction conditions in each reactor, the polymer fractions produced in each reactor will have their own molecular weight distribution and average weight molecular weight. When the molecular weight distribution curve of such a polymer is recorded, the individual fraction curves together form the characteristic stretched molecular weight distribution curves for the total polymer product obtained.

[0071] The multimodal LLDPE copolymer used in the present invention includes the lower weight average molecular weight (LMW) component (A) and the higher weight average molecular weight (HMW) component (B). Said LMW component has a lower molecular weight than the HMW component.

[0072] Naturally, the multimodal LLDPE copolymer may be, and preferably is, multimodal in terms of density and comonomer content. For example, the LMW and HMW components preferably have different comonomer contents and densities.

[0073] Multimodal LLDPE is preferably produced using a coordination catalyst, preferably selected from Ziegler Natta catalysts, unilateral catalysts that contain metallocene and non-metallocene catalysts and Cr catalysts or mixtures of any of them, more preferably it is produced by Ziegler Natta catalysts. Here, such polymers are referred to as znLLDPE copolymers. [0074] The multimodal copolymer LLDPE, preferably the multimodal copolymer znLLDPE, preferably includes:

(A) from 30 to 70% by weight (% by weight), preferably from 40 to 60% by weight, based on the combined amounts of components (A) and (B), of a low molecular weight ethylene polymer (LMW) selected from an ethylene homopolymer and an ethylene copolymer of one or more alpha-olefin comonomer having from 3 to 20 carbon atoms, and (B) from 30 to 70% by weight, preferably from 40 to 60% by weight, based on the combined amounts of components (A) and (B) . high molecular weight (HMW) ethylene copolymer of one or more alpha-olefin comonomer having from 3 to 20 carbon atoms, where the components LMW and HMW are different.

[0075] More preferably, the multimodal LLDPE copolymer, preferably the multimodal ZnLLDPE copolymer, includes:

(A) from 40 to 60% by weight, preferably 45 to 55% by weight, based on the combined amounts of components (A) and (B), a low molecular weight ethylene polymer (LMW) selected from an ethylene homopolymer or ethylene copolymer and one or more alpha-olefins having from 3 to 16 carbon atoms, preferably having a weight average molecular weight from

5000 up to 150,000 g / mol, preferably 5,000 to 130,000 g / mol, preferably from 10,000 to 100,000 g / mol, more preferably from 15,000 to 80,000 g / mol; and (B) from 40 to 60% by weight, preferably 45 to 55% by weight, based on the combined amounts of components (A) and (B), of high molecular weight ethylene copolymer (HMW) of one or more alpha-olefin comonomer having from 3 to 16 carbon atoms and preferably having a weight average molecular weight from 100,000 to 1,000,000 g / mol, preferably from 130,000 to 500,000 g / mol, more preferably from 150,000 to 500,000 g / mol.

[0076] The low molecular weight ethylene polymer (A) is an ethylene homopolymer or copolymer and preferably has a density that is higher than the density of the HMW component (B). The MFR2 (ISO 1133, 190 ° C at 2.16 charge) of said (LMW) ethylene homopolymer or copolymer is preferably less than 400 g / 10 min, preferably from 4.0 to 400 g / 10 min. Preferably, the ethylene homopolymer (LMW) (A) has a density lower than 960 kg / m³, preferably from 910 to 950 kg / m³.

[0077] The high molecular weight copolymer (B) is a copolymer of ethylene and one or more alpha-olefins having from 4 to 10, preferably 4 to 8 carbon atoms.

[0078] MFR2 (ISO 1133, 190 ° C at 2.16 charge) of said ethylene copolymer (HMW) (B) is preferably less than 0.5 g / 10 min, more preferably from 0.01 to 0.3 g / 10 min The high molecular weight ethylene copolymer (B) of the PE copolymer preferably has a density of 890 to 930 kg / m³, preferably from 900 to 920 kg / m³.

[0079] The LLDPE copolymer, preferably the multimodal znLLDPE copolymer, may have a density of 950 kg / m³ or lower, preferably from 905 to 940 kg / m³. In particular, for the preferred multimodal ZnLLDPE copolymer, the density is preferably more than 915 kg / m³. In certain end applications, the multimodal ZnLLDPE copolymer preferably has a density of 915 to 935 kg / m³.

[0080] The melt flow rate of the polymer melt, MFR2 (ISO 1133, 190 ° C at 2.16 charge) for an LLDPE copolymer, preferably a multimodal ZnLLDPE copolymer, is preferably in the range of 0.01 to 20 g / 10min, preferably from 0.05 up to 10 g / 10min, preferably from 0.05 to 5.0 g / 10min, more preferably in the range of 0.05 to 2.5 g / 10min, and even more preferably from 0.1 to 0.5 g / 10 min.

[0081] The term "LLDPE copolymer" as used herein includes polymers containing a repeating unit derived from ethylene and at least one other C3-20 aflaolefin monomer. Preferably, the LLDPE copolymer, preferably the multimodal ZnLLDPE copolymer, can be made from ethylene together with at least one C4-10 alpha-olefin comonomer, e.g. 1-butene, 1-hexene or 1-octene. Preferably, the LLDPE copolymer, preferably the multimodal znLLDPE copolymer, is a double copolymer, e.g. the polymer contains ethylene and one comonomer, or terpolymer, i.e. the polymer contains ethylene and two or three comonomers. Preferably, the LLDPE copolymer, preferably the multimodal ZnLLDPE copolymer, includes an ethylene-hexene copolymer, an ethylene-octene copolymer or an ethylene-butene copolymer. The amount of comonomer present in the LLDPE copolymer, preferably the multimodal ZnLLDPE copolymer, is at least 0.01 mol%, preferably from 0.02 to 12% by weight, more preferably from 0.3 to 8% by weight. in relation to ethylene.

[0082] The multimodal LLDPE copolymer may also contain polymer components, e.g., three components that are a tri-modal LLDPE copolymer. The amount of such additives is preferably up to 10% by weight, preferably up to 5% by weight, based on the PE copolymer. Preferably, the multimodal LLDPE copolymer comprises the LMW and HMW polymer components. Optionally, the multimodal LLDPE copolymer, e.g. preferably a bimodal PE copolymer, may also contain, e.g., up to 5 wt. a well-known polyethylene prepolymer that is obtainable by prepolymerization well known in the art, e.g. as described in WO / 9618662. For such a prepolymer, the polymer precomponent is usually included in one of the components of LMW and HMW or alternatively produces separate Mw fractions, e.g. an additional LLDPE copolymer component and those that also provide multimodality. [0083] By ethylene homopolymer is meant a polymer that substantially contains ethylene units. During the process, small portions of different polymers can get into the reactor, which will cause other types of polymer impurities other than ethylene to occur.

[0084] The LLDPE copolymer, preferably multimodal znLLDPE copolymers suitable for the present invention is commercially available and can be produced separately to get a good understanding of the process described in the literature. As an example of the commercial availability of useful multimodal polymers, LLDPE are, without limitation, LLDPE available under the Borealis brand, known as the Borstar® FBXXXX brand, such as Borstar® FB4370, FB2230 etc.

[0085] As mentioned above, the polymer component (2), preferably the multimodal LLDPE copolymer, can be polymerized using a coordination catalyst such as a Ziegler Natta (ZN) catalyst, an SS catalyst such as a metallocene or non-metallocene catalyst or a Cr catalyst of them, more preferably using a ZN or SS catalyst.

[0086] When the catalyst is an SS catalyst, preferably the one-sided catalyst is a metallocene catalyst. Such a catalyst contains a transition metal compound that typically contains an organic ligand, preferably a cyclopentadienyl, indenyl or fluorenyl ligand. Preferably, the catalyst contains two cyclopentadienyl, indenyl or fluorenyl ligands which can be linked by a group preferably containing a silicon and / or carbon atom. Then, the ligands may have substituents such as alkyl groups, aryl groups, arylalkyl groups, alkylaryl groups, silyl groups, siloxy groups, alkoxy groups and the like. Suitable metallocene compounds are known in the art and disclosed, among others, in WO97 / 28170, WO98 / 32776, WO99 / ​​61489, WO03 / 010208 WO03 / 051934, WO03 / 051514, WO2004 / 085499, WO2005 / 002744, EP1752462A and EP1739103A.

[0087] In a preferred embodiment, the polymer component (2), preferably the multimodal LLDPE copolymer, is produced using ZN. Preferably, the LMW and HMW components are produced using the same ZN catalysts.

[0088] The Ziegler-Natta polymerization catalyst used in the polymerization of the polymer component (2), preferably multimodal LLDPE, is not critical and may be, e.g., any ZN catalyst suitable for producing the ZnLLDPE multimodal copolymer according to the invention. Accordingly, Ziegler-Natta catalysts are one of the best known and commonly used coordination catalysts for the production of polymers and typically contain a transition metal component and an activator. A typical example of ZN catalysts is that produced by activating titanium halides with organometallic compounds such as triethylaluminum.

[0089] More specifically, the transition metal component typically contains Group 4 or 5 metal of the Periodic Table (IUPAC) as active metal. In addition, it may contain other metals or elements such as elements of Groups 2, 13 and 17.

[0090] Preferably and as mentioned above, the polymerization catalyst comprises a titanium compound, an aluminum compound and a magnesium compound. The Ziegler-Natta catalyst may be a homogeneous Ziegler-Natta catalyst or, alternatively, a heterogeneous catalyst, i.e. a solid Ziegler-Natta catalyst, which may be a solidified or precipitated substrate product or supported by an external substrate.

[0091] The titanium compound is usually a titanium-containing halogen compound, preferably a chlorine-containing titanium compound. Tetrachloride is a particularly preferred titanium compound.

[0092] The aluminum compound is usually an aluminum alkyl compound. Aluminum alkyl dichloride is a particularly preferred compound.

[0093] The magnesium compound is usually the reaction product of magnesium dialkyl, alcohol and halogenating agent. Alcohol is usually a linear or branched aliphatic monoalcohol.

[0094] The external substrate may be an inorganic oxide such as silica, alumina, titanium oxide, silica 28-alumina or a magnesium based substrate such as magnesium dichloride.

[0095] One preferred catalyst may be prepared by sequentially contacting the support with the above-mentioned compounds as described in EP688794A or WO99 / ​​51646. Alternatively, it can be prepared by initially preparing a solution of ingredients and then contacting the solution with the carrier as described in WO01 / 55230. Other suitable Ziegler Natta catalysts contain titanium compounds together with magnesium halide compounds as a base. Hence, the catalyst contains a titanium compound on magnesium dihalide, such as magnesium dichloride. Such catalysts have been disclosed, for example, in WO2005 / 1186 and EP810235A. Also, incarnations of Ziegler-Natta catalysts are still preferably prepared by a process in which an emulsion is prepared in which active ingredients are suspended, e.g., a discontinuous emulsion phase consisting of at least two liquid phases. The dispersed phase, in the form of droplets, solidifies in an emulsion, where the catalyst is produced in the form of solid particles. Preparation principles for this type of catalyst are given in WO2003 / 106510 Borealis.

[0096] Ziegler-Natta catalyst is used with an activator. Suitable activators are metal alkyl compounds, especially aluminum alkyl compounds. These compounds also include aluminum alkyl halides.

[0097] For the unimodal polymer component (2), e.g. the LLDPE polymer, it is preferable to prepare using single-step polymerization, e.g. with the loop in a manner well known in the art.

[0098] The preferred polymer component (2) is a multimodal (e.g. bimodal) LLDPE copolymer that can be made by mechanically mixing two or more separately prepared polymer components or, preferably, by in-situ mixing in a multi-step polymerization process during ingredient preparation polymer. Both mechanical and in-situ mixing are well known in the art.

[0099] Accordingly, a preferred multimodal LLDPE copolymer is prepared by in-situ mixing in a multi-stage polymerization process, i.e. in two or more stages, or by using two or more different polymerization catalysts, including multi- or two-site catalysts, in one-step polymerization.

[0100] Preferably, the multimodal LLDPE copolymer is produced in at least two stages of polymerization using the same Ziegler-Natta catalyst. Hence, for example, two precipitation reactors or two gas phase reactors, or any combination thereof, in any order, can be used. Preferably, however, the multimodal LLDPE copolymer is produced using a solvent-based precipitation polymerization in a loop reactor followed by gas phase polymerization in a gas phase reactor.

[0101] Loop reactor system - gas phase reactor is sold by Borealis as a reactor system

BORSTAR. The multimodal LLDPE copolymer is therefore preferably produced in a two-step process comprising firstly solvent precipitation polymerization followed by gas phase polymerization.

[0102] The conditions used in this process are well known. For precipitation reactors, the reaction temperature is usually in the range of 60 to 110 ° C (e.g. 85-110 ° C), the pressure in the reactor is usually in the range of 5 to 80 bar (e.g. 50-65 bar), and the residence time is usually in the range of 0.3 to 5 hours (e.g. 0.5 to 2 hours). The diluent used is usually an aliphatic hydrocarbon with a boiling point in the range -70 to + 100 ° C. In such reactors, polymerization can, if desired, be carried out under supercritical conditions. Precipitation solvent polymerization can be carried out in bulk, where the reaction medium is formed from the polymerized monomer.

[0103] For gas phase reactors, the reaction temperature is usually in the range of 60 to 115 ° C (e.g., 70 to 110 ° C), the pressure in the reactor is usually in the range of 10 to 25 bar, and the time the residence time is 1 to 8 hours. The gas commonly used as inert gas is nitrogen or low-boiling hydrocarbons such as propane together with a monomer (e.g. ethylene).

[0104] Preferably, the low molecular weight polymer fraction is produced continuously in a loop reactor, where ethylene is polymerized in the presence of a polymerization catalyst as defined above and the chain transfer agent is hydrogen. The diluent is usually an inert aliphatic hydrocarbon, preferably isobutane or propane. [0105] The higher molecular weight component may be made with the same catalyst in the gas phase reactor.

[0106] Because the higher molecular weight component is produced second in multi-step polymerization, it is not possible to measure its properties directly. However, a person skilled in the art is able to determine the density, MFR2 etc. of a higher molecular weight component using the Kim McAuley equation. Hence, both density and MFR2 can be calculated using KK McAuley and JF McGregor: On-line Inference of Polymer Properties in an Industrial Polyethylene Reactor, AlChE Journal, June 1991, Vol. 37, No., 6, pages 825-835.

[0107] The density is calculated from the McAuley equation 37, where the final density and density after the first reactor are known. [0108] MFR2 is calculated from the McAuley 25 equation, where the final MFR2 and MFR2 after the first reactor is calculated. The use of these equations to calculate polymer properties in multimodal polymers is common.

[0109] The polymer composition containing the multimodal LLDPE copolymer is homogenized and processed to pellet form using a method known in the art. A review is given, for example, in Rauwendaal: Polymer Extrusion (Hanser, 1986), chapters 10.3 to 10.5, pages 460 to 489.

Ingredient: Carbon black (3) [0110] Optionally, the carbon black (CB) used in component CB (3) may be any CB suitable for the polymer composition, for example any conventional carbon black commercially available used in conduit layers, preferably in sheath layers. Suitable examples are so-called furnace carbon blacks, which are well known in the art and documented in the literature. As non-exhaustive examples of suppliers of such kiln cages, mention may be made, e.g. Cabot, Evonic or Columbian.

[0111] CBs used in the present invention are preferably incorporated in the polymer composition as a single dose (CBMB). CBMB contains CB in a polymeric support. CBMBs are commercially available or can be produced in e.g. a conventional mixing process. CB in the form of CBMB is easy to use and can be added to the components of the polymer composition.

[0112] The polymeric carrier may be any suitable polymer, e.g., conventional LDPE polymer produced by high pressure process or conventional polymer produced by low pressure process, such as LLDPE polymer. As examples of suitable polymeric supports, e.g. the polymers described above in the sections polymer component (1) and (2), may be mentioned, but not limited to them. A preferred polymeric carrier is an LDPE hompolymer or a copolymer of LDPE ethylene and one or more comonomers as defined with respect to the polymer component (1). [0113] The amount of CBMB used is as defined above for component CB (3). The amount of CB in one dose can vary in a known manner. Typically, CBMB contains carbon black up to 90% by weight, preferably 1 to 70% by weight, more preferably 5 to 60% by weight, more preferably 10 to 50% by weight, even more preferably 20 to 40% by weight. , based on the total amount of CBMB. The amount of polymer support in the CBMB is usually at least 10 wt.%, Preferably 30 to 99 wt.%, Preferably 40 to 95 wt.%, More preferably 50 to 90 wt.%, More preferably 60 to 80 wt.% ., in relation to the total quantity of CBMB.

End uses and final conclusions of the invention [0114] The new polymer composition according to the invention is highly useful in a wide range of polymer end uses. Wire and wire (W&C) applications are the preferred use of the polymer composition.

[0115] Accordingly, the invention is directed to conductors (referred to herein as Conductors) comprising a conductor surrounded by at least one polymer layer comprising a polymer composition that comprises a polymer component and optionally carbon black (CB), wherein the polymer composition has a modulus of elasticity lower than 390 MPa, if determined according to ISO 178 using a compressed test sample (80 x 10 x 4.0 mm, length x width x thickness) and strain at break (%) 700% or more if determined according to ISO

527-1: 1993 using a compressed test sample prepared in accordance with ISO527-2: 1993 5A.

[0116] As stated above, a detailed description of the preferred properties, subgroups and incarnations of the polymer composition and its components given above applies likewise preferably to the Wires of the invention.

[0117] Said at least one layer of the Conduit containing the polymer composition as defined above and below is preferably at least a sheath layer.

[0118] The conduit is preferably selected from

- communication wires for communication applications comprising one or more wires surrounded by at least one layer, which is preferably an insulating layer, and one wire or a bundle consisting of two or more wires surrounded by at least a sheath layer, which is also called a sheath layer, and which forms the outermost polymer layer protecting one or more wires or with;

- power cords that comprise a conductor surrounded by at least one layer, preferably at least an insulating layer and a covering layer, in that order, wherein at least one layer comprises a polymer composition as defined above or in the claims below. Communication and power cords are well known in the W&C area.

[0119] A communication cable is a cable for transmitting information signals, such as a telecommunications cable or coaxial cable. The telecommunications wire contains a multitude of telemonopolar wires, each surrounded by an insulating composition, usually an insulating layer. The number of telemonopolar wires may vary from a few in data transmission wires to even several thousand in telephone wires. All these wires are surrounded by an ordinary sheath layer, also called a sheath layer, which surrounds and protects the bundle of wires. Preferably, the sheath layer comprises the polymer composition of the invention.

[0120] The coaxial cable is usually one centrally arranged conductor and at least one external concentric conductor. If more than one external conductor is used, e.g. triaxial cables, they are separated by an electrically insulating layer. Also, the coaxial lines are surrounded by at least a sheath, also called a sheath layer. The sheath layer preferably comprises, more preferably is composed of the polymer composition of the invention.

[0121] The power cord is an energy transfer cord operating at any voltage, typically at voltages higher than 220 V. The voltage used in the power cord may be variable (AC), constant (DC) or transient (pulse). The polymer composition is also very suitable for layers of power cords, such as low voltage (LV) cables (e.g. 1 kV), medium voltage (MV), high voltage (HV) and very high voltage (EHV) cables, all names of which are well known and indicate the operational levels of such cables.

[0122] Preferably, the MV, HV and EHV wires of the embodiment of the invention comprise at least an inner semiconductor layer, an insulating layer, a sheath layer, an outer semiconductor layer and, optionally, and preferably, a sheath layer, in this order, where at least one of said layers, preferably at least the covering layer comprises, preferably consists of said polymer composition according to the invention.

[0123] Preferably, the embodiment feed wire is an LV feed wire, i.e. a 1 kV wire, which comprises at least an insulating layer and, optionally, a backing layer, and optionally and preferably, a covering layer, in this order, where at least one of said layers, preferably at least the covering layer comprises, preferably is composed of said polymer composition according to the invention.

[0124] Wires according to the present invention may be produced according to methods known in the art using a polymer composition as described above.

[0125] The components of the polymer composition may be provided for the process of making the Conduits in the form of granules, powder or pellets. The pellets can be of any shape and size.

[0126] Accordingly, the invention further provides a process for the preparation of the Cable, which comprises the steps of a) applying to the conductor one or more layers of the polymer composition described above.

[0127] The process for making a wire, such as a communication or power cord, as defined above and below, involves mixing the molten components, e.g. mixing the components of the polymer composition as described above, including subgroups and incarnations of the composition, optionally with another polymer component and optionally with additives, above the pour point of at least one of the main polymer components of the resulting mixture, and (co) extruding the resulting molten mixture on a conductor to form one or more a polymer layer, wherein the at least one layer comprises a polymer composition. Mixing of the melted components is preferably carried out at a temperature 20-25 ° C higher than the pour or softening point of the polymer component.

[0128] Preferably, said polymer composition is a mixture of Polymer Components (1) and (2) and optionally, and preferably, carbon black (CB) (3). The polymer components (1) and (2) and preferably component CB (3) are mixed together in a conventional mixer and / or extruder for the production of pipes. The polymer components (1) and (2) are each preferably added in pellet form to the mixing step and then mixed molten. Preferably the component CB (3), preferably one dose (CBMB) (3), is then added to the mixture of polymer components (1) and (2). The amounts used and the preferred amounts are set out above and in the claims. An additional component, e.g. additional additives, may be added before or during the manufacturing process of the Cable. Manufacturing temperatures and devices are well known in the art, e.g. conventional mixers or extruders, such as single or twin screw extruders, are suitable for this invention.

[0129] The wire may be crosslinked, wherein at least one of the layers may be crosslinked to provide a crosslinked Wire. The invention also provides a cable that is crosslinkable and a crosslinked cable.

Accordingly, the process for producing the Conduit optionally comprises the following subsequent steps b) crosslinking the crosslinkable polymer, e.g., the crosslinkable polymer composition, in at least one layer of the conductor of the resulting Conduit, where the crosslinking effect is possible in the presence of a crosslinker, which is preferably a peroxide. Usually the crosslinking temperature is at least 20 ° C higher than the temperature used in the mixing stage of the polymer melt and can be estimated by a person skilled in the art. [0131] Applicable manufacturing and crosslinking processes and devices are known and well documented in the literature.

[0132] The Conduit layer comprising the polymer composition is preferably composed of a polymer composition.

Determination Methods [0133] Unless otherwise stated, the following methods were used to determine the properties of the polymer composition or components thereof as described in the description or in the experimental section and the claims below. Unless otherwise stated, the samples used for testing are composed of a polymer composition or, respectively, a polymer component as specified.

Melt index [0134] The melt flow (MFR) is determined according to ISO

1133 and is given in g / 10 min. MFR is an indicator of the melt viscosity of the polymer. The MFR was determined at 190 ° C for PE and 230 ° C for PP. The load at which the melt flow rate has been determined is usually given in the index, for example

MFR2 is measured under a load of 2.16 kg (condition D), MFR5 is measured under a load of 5 kg (condition T) or MFR21 is measured under a load of 21.6 kg (condition G).

Density [0135] The density of the polymer was measured according to ISO 1183 / 1872-2B.

[0136] For the purposes of the invention, the density of the mixture was calculated from the density of the ingredients according to:

Pi = L.ⁱⁿand Ά f

where ρΐ3 is the density of the mixture, wi is the mass fraction of the "i" component in the mixture, and Pi is the density of the "i" component.

[0137] Mz, Mw, Mn, and MWD were measured by gel permeation chromatography (GPC) according to the following method:

The weight average molecular weight Mw and the molecular weight distribution (MWD = Mw / Mn, where Mn is the number average molecular weight and Mw is the weight average molecular weight; Mz is with the average molecular weight) is measured according to ISO 16014-4: 2003 and ASTM D 6474-99. The Waters GPCV2000, equipped with a refractive index detector and viscometer, was used together with 2 x GMHXL-HT and 1 x G7000HXL-HT TSK gel columns from Tosoh Bioscience and 1,2,4-trichlorobenzene (TCB, stabilized 250 mg / L 2.639

Ditertbutyl-4-methyl-phenol) as a solvent at 140 ° C and a constant flow of 1 ml / min. 209.5 μΐ of sample solution was injected for analysis. The column system was calibrated using universal calibration standards (according to ISO 16014-2: 2003) Polystyrene (PS) with at least 15 narrow

MWD in the range from 1 kg / mol to 12,000 kg / mol. All samples were prepared by dissolving 0.5 - 4.0 mg of polymer in 4 ml (at 140 ° C) of stabilized TCB (same as the mobile phase) and holding for a maximum of 3 hours at a maximum temperature of 160 ° C with continuous gentle shaking before to the GPC camera.

[0138] Flexibility module

The Flexibility Module has been determined according to ISO 178: 1993. The test sample was prepared from pellets of the tested polymer composition pressed to 80 x 10 x 4.0 mm (length x width x thickness). The distance between the substrates was 64 mm, the test speed was 2 mm / min, and the sample load was 100 N. The equipment used was Alwetron TCT 25.

Mechanical properties

Stress at Break and Strain at Break [0139] Stress at Break and Strain at Break were measured according to ISO 527-1: 1993 using a sample prepared according to ISO527-2 1993 5A (compressed test sample prepared from pellets of the tested polymer composition).

[0140] Stress tester for stress at break: Alwetron

TCT10, Lorentzen & WettreAB

Drawing speed: 50mm / min

Effective sample length: 50mm

Method of determining short chain branches (SCB)

Determination of short chain branches as a function of molecular weight (SCB profile (MW)):

[0141] Molecular weight distribution (MWD) and short chain branches as a function of molecular weight were determined using Gel Permeation Chromatography (GPC). The Waters GPC2000, equipped with a flow heated cell (at 140 ° C) connected to a heat exchanger (at 140 ° C) was used with 2 x Olexis and 1 x Olexis Guard columns from Polymer Laboratories and 1,2,4-trichlorobenzene (TCB ) as a solvent at 140 ° C and a constant flow of 1 ml / min. A heated flow cell was placed on a sample plate in a Perkin Elmer Spectrum 100 equipped with an MCT detector. The MCT detector is cooled with liquid nitrogen. During the chromatographic test, a series of FTIR spectra was obtained using Perkin Elmer TimeBase V3.0 software. The spectrometer was set to collect 16 spectra, in the scan range from 3000 cm^-1 up to 2700 cm^-1, resolution 8 cm^-1. The background spectrum was taken during the GPC test under operating conditions and was subtracted from each spectrum collected during the chromatographic tests. 423.5 μΐ sample solution was injected for analysis. The column system was calibrated using universal calibration standards (according to ISO 16014-2: 2003) polystyrene (PS) with at least 10 narrow MWDs in the range of 0.6 kg / mol to 6,000 kg / mol. Mark Houwink constants used for PS and PE are, according to ASTM D 6474-99. All samples were prepared by dissolving 7.0 - 9.0 mg of polymer in 4 mL (at 140 ° C) stabilized TCB (stabilized with 250 mg / L 2,6-Ditert-butyl-4-methyl phenol) and held for a maximum of 3 hours at a maximum of 160 ° C with continuous gentle shaking before feeding to the GPC apparatus. Spectral data by Perkin Elmer TimeBase 3.0 software was imported into the Polymer Laboratories Cirrus V3.1 software and molecular weight and molecular weight distribution evaluation. The spectral data were converted to chromatograms using root-mean-square RMS absorbance in the range of 3000-2700 cm^-1. Molecular weight distributions were calculated from generated chromatograms and by universal calibration. Corrections for the possible effects of long chain branching on hydrodynamic volume, intrinsic viscosity and the molecular weight calculated in succession were not carried out.

[0142] Short chain branching evaluation was carried out as described in PJ DesLauriers, DC Rohlfing, ET Hsieh; Polymer 2002, 43, 159-170. This chemometric method is a correlation of the absorption spectrum obtained by FTIR and retention time or segments of molecular weight, respectively, with methyl branches per 1000 total carbon atoms obtained in carbon 13C nuclear magnetic resonance (NMR) spectroscopy.

[0143] The set of short branching chains covers a wide range of differently branched polyethylenes to generate the most universal SCB calibration. This set includes over 100 samples, both catalysed with a single-sided catalyst and Ziegler Natta catalyzed fraction for high molecular weight polyethylene, co-butylene, polyethylene-co-hexene and polyethylene-co-octene, as well as nalkans with a degree of branching from 0 to 67 methyl groups per 1000 total carbon atoms (CH3 / 1000TC). Calibration samples having a probability> 0.95 during the chemometric model generation time were considered outliers. The degree of branching of all samples was determined for molten samples by 13C NMR or calculated for n-alkanes. The four-component calibration model was generated from partial least squares regression (PLS1) using the Infometrix Pirouette 3.11 software.

[0144] Evaluation of short chain branches was carried out by multivariate analysis by using a chemometric calibration model. The isolated detection value for individual measurements was generated from the probability value. Both were obtained using software (Infometrix Instep 1.2) in conjunction with the Cirrus software add-on - Polymer Laboratories FTIR. Short chain branches have been defined as methyl branches per 1000 total carbon atoms (CH3 / 1000TC). There were no corrections for chain terminating methyl groups. SCB data with a probability> 0.96 were considered outliers.

Calculation of the main data part (middle part 90% w / w total MWD) [0145] Normalized cumulative curves (total area under the curve is 1) of the molecular weight distribution were calculated from MWD (dw / dlogM as a function of logM). SCB data was used only obtained in the range 0.055 <x <0.95 (mass fraction) or 5 wt% <x <95 wt% (weight percentage) respectively. The arithmetic mean was calculated from the SCB data (expressed as CH3 / 1000TC) in the 90% molecular weight centered area.

ESCR (Environmental Stress Cracking) [0146] The determination was carried out according to the procedure described in IEC 60811-4-1: 2004, Chapter 8, "Resistance to environmental stress cracking", Procedure B, 10% solution (by volume) in Igepal water CO-630. The International Electrotechnical Commission (IEC) is a global standardization organization bringing together all the National Electrotechnical Committees (IEC National Committees). Compressed test samples were prepared from pellets of the tested polymer composition.

Rheology, dynamics (Viscosity, Shear thinning index):

[0147] Rheological parameters such as SHI shear thinning index and Viscosity were determined using a rheometer, preferably an Anton Paar Physica MCR 300 Rheometer on molded samples under a nitrogen atmosphere at 190 ° C using plates with a diameter of 25 mm and a distance between plates 1, 8 mm. Experiments with oscillatory stresses were performed in the range of linear viscosity at deformation frequencies from 0.05 to 300 rad / s (ISO 6721-1). Five measuring points were made per decade.

[0148] The values ​​of the resting modulus (G '), loss modulus (G "), complex modulus (G *) and complex viscosity (η *) were obtained as frequency functions (ω). Η100 is used as an abbreviation for complex viscosity at frequency 100 rad / s.

[0149] The shear thinning index (SHI), which is correlated with MWD and is independent of Mw, was calculated according to Heino ("Rheological characterization of polyethylene fractions" Heino, EL, Lehtinen, A., Tanner J., Seppala, J ., Neste Oy, Porvoo, Finland, Theor Appl. Rheol., Proc.

Int. Congr. Rheol, 11 (1992), 1, 360-362, and "The influence of molecular structure on some rheological properties of polyethylene", Heino, EL, Borealis Polymers Oy, Porvoo, Finland, Annual Transactions of the Nordic Rheology Society, 1995. ). [0150] The SHI value is obtained by calculating complex viscosities at given complex module values ​​and calculating the ratio of two viscosities. For example, using the values ​​of 2.7 kPa and 210 kPa, then, η * (2.7 kPa) and η * (210 kPa) are obtained for the constant values ​​of 2.71 kPa and 210 kPa, respectively. The shear thinning index SHI2,7 / 210 is then determined as the ratio of two viscosities η * (2,7 kPa) and η * (210 kPa), i.e. η (2,7) / η (210).

[0151] It is not always practical to directly measure complex viscosities at low frequency values. The value can be extrapolated by carrying out measurements to a frequency of 0.126 rad / s, drawing a graph of complex viscosity as a function of frequency on a logarithmic scale, drawing the best-fit line through five points corresponding to the lowest frequency values ​​and reading the viscosity value from this line.

Experimental part:

Polymer components of examples of the invention:

[0152] Polymer component (1): LDPE (1), which is a conventional low-density polyethylene homopolymer, produced in a high-pressure process in a tubular reactor, with the data properties in Table 2.

Polymer component (2): Multimodal (bimodal) znLLDPE (2)

Catalyst preparation:

Preparation of the complex:

[0153] 87 kg of toluene was added to the reactor. Then 45.5 kg Bomag A in heptane was added to the reactor. 161 kg of 99.8% 2-ethyl-1-hexanol was introduced into the reactor at a flow rate of 24-40 kg / h. The molar ratio between BOMAG-A and 2-ethyl-1-hexanol was 1: 1.83.

Preparation of the solid catalyst component:

[0154] 275 kg of silica (ES747JR Crossfield, average particle size 20 Pm) activated at 600 ° C in nitrogen was charged to the catalyst preparation reactor. Then, 411 kg of 20% EADC (2.0 mmol / g silica) was diluted in

555 liters of pentane and added to the reactor at ambient temperature in an hour. The temperature then rises to 35 ° C while stirring the silica for one hour. The silica was dried at 50 ° C for 8.5 hours. Then 655 kg of the prepared complex as described above (2 mmol Mg / g silica) was added at 23 ° C over ten minutes. 86 kg of pentane was added to the reactor at 22 ° C for ten minutes. The suspension was stirred for 8 hours at 50 ° C. Finally, 52 kg of TiCl4 were added in 0.5 hour at 45 ° C. The suspension was stirred at 40 ° C for five hours. The catalyst was then dried by nitrogen washing.

Polymerization:

[0155] The multimodal ZnLLDPE polymer was prepared in a multi-stage pilot scale reactor system comprising a loop reactor and a gas phase reactor. The pre-polymerization step precedes the actual polymerization. The pre-polymerization step was carried out in suspension at 50 dm³ loop reactor at about 80 ° C at a pressure of about 65 bar using a polymerization catalyst prepared as described above and triethylaluminum as a cocatalyst. The molar ratio of aluminum cocatalyst to titanium catalyst was about 20. Ethylene was given in the ratio (200g C2) / (1g / catalyst). Propane was used as the diluent and hydrogen was added in an amount to adjust the MFR2 of the prepolymer to about 10 g / 10 min. The resulting suspension together with the pre-polymerization catalyst and triethylaluminum cocatalyst was transferred to the actual polymer stage₃ ryization, i.e. introduced up to 500 dm³ loop reactor, continuously fed with propane, ethylene and hydrogen. The H2 / C2 ratio in the reaction mixture was 240 mol / kmol. In addition, the comonomer, 1-butene, was added to the loop reactor in the amount given in Table 1 below. The reactor was operated at 95 ° C and 60 bar pressure. Process conditions were selected as shown in Table 1 to produce a polymer having MFR2 300 g / 10 min and a density of about 951 kg / m³with a production capacity of about 30 kg / h.

[0156] The slurry was then transferred to a fluidized bed gas phase reactor, where ethylene, 1-butene comonomer and hydrogen were added, together with nitrogen as inert gas to produce the HMW component in the presence of the LMW component. The H2 / C2 ratio in the return gas was 7 mol / kmol and the C4 / C2 ratio was 460 mol / kmol. The gas phase reactor was operated at 80 ° C and 20 bar pressure. The polymer production capacity was about 75 kg / h. The split (wt.%) Loop / gas phase reaction was 41/59. The polymer obtained in the gas phase reactor had an MFR2 of 0.2 g / 10 min and a density of about 923 kg / m³.

[0157] The powder from the reactor was then stabilized with known additives and converted into pellets in a known manner using a CIM90P counter-rotating twin screw extruder manufactured by Japan Steel Works. Polymerization conditions, polymer and product properties in pellet form are given in Table 1 below.

Table 1: Polymerization conditions and properties of the polymer product obtained in Example 1

<td>Polymer</td><td>Example znLLDPE</td><td> 1</td>

<td>Ethylene concentration in the loop reactor, mol-%</td><td colspan="2"> 6,7</td>

<td>Hydrogen to ethylene ratio in a loop reactor</td><td> 240</td><td></td>

<td>tla, mol / kmol</td><td></td><td></td>

<td>Ratio of 1-butene to ethylene in a batch reactor</td><td> 570</td><td></td>

<td>tla, mol / kmol</td><td></td><td></td>

<td>Production capacity in the loop reactor, kg / h</td><td colspan="2"> 30</td>

<td>MFR2 of polymer produced in a reactor with</td><td> 300</td><td></td>

<td>loop, g / 10 min</td><td></td><td></td>

<td>The density of the polymer produced in the reactor with</td><td> 951</td><td></td>

<td>loop, kg / m³</td><td></td><td></td>

<td>Ethylene concentration in the phase reactor</td><td> 19</td><td></td>

<td>gas, mol-%</td><td></td><td></td>

<td>The ratio of hydrogen to ethylene in the reactor from</td><td> 7</td><td></td>

<td>gas phase, mol / kmol</td><td></td><td></td>

<td>The ratio of 1-butene to ethylene in the reactor with re</td><td> 460</td><td></td>

<td>gas phase action, mol / kmol</td><td></td><td></td>

<td>The yield of polymer production in the reactor from re</td><td> 75</td><td></td>

<td>action in the gas phase, kg / h</td><td></td><td></td>

<td>Loop / gas phase separation</td><td colspan="2"> 41/59</td>

<td>MFR₂ final polymer in pellets, g / 10 min</td><td colspan="2"> 0,2</td>

<td>Final polymer density in pellets, kg / m³</td><td colspan="2"> 923</td>

[0158] CB component (3): One dose of carbon black and polymer carrier. contains 35 wt. CB, which is furnace carbon black provided by Evonic, and 75 wt. a polymer support, which is a conventional LDPE homopolymer, produced in a high pressure process. The properties are summarized in Table 2. Reference examples:

[0159] Reference 1: Commercially available low density polyethylenes used as references used in the protective layers contain 88 wt. Conventional LDPE reference homopolymer produced in a high pressure process, 5.5 wt. conventional ethylene copolymer with vinyl acetate comonomer (VA content 28%) produced by high pressure process and 6.5 wt. CBMB component (3). In this way, the CBMB component is the same CBMB (3) component of the composition according to the invention given above. The properties are summarized in Table 2.

[0160] Reference Example 2: Commercially available bimodal linear low density polyethylene copolymer (LLDPE) produced in the presence of a conventional Ziegler-Natta catalyst in a low pressure process and used in protective layers of conductors. Reference 2 zaaver 93.0 wt. reference copolymer of ZnLLDPE and 7.0 wt. CBMB component (3). Thus, the CBMB component is the same CBMB (3) component of the composition according to the invention given above. The properties are summarized in Table 2.

Table 2: Properties of polymer components and inventiveness and references of polymer compositions and experimental data

<td>Couple-</td><td>skł</td><td>compos</td><td>skł</td><td>Wyn.</td><td>Wyn.</td><td>Wyn.</td><td>com-</td><td>refer-</td><td>From-</td>

<td>meter</td><td>ad-</td><td>Employee</td><td>ad-</td><td>com-</td><td>com-</td><td>com-</td><td>positive</td><td>not</td><td>no-</td>

<td></td><td>Score</td><td>poly</td><td>Score</td><td>positive</td><td>positive</td><td>positive</td><td>tion</td><td> 1</td><td>Power Grid</td>

<td></td><td>after-</td><td>me-</td><td>CB</td><td>tion</td><td>tion</td><td>tion</td><td>poly-</td><td></td><td>no</td>

<td></td><td>Li-</td><td>trenches</td><td> 3</td><td>poly-</td><td>poly-</td><td>poly-</td><td>mero-</td><td></td><td> 2</td>

<td></td><td>me-</td><td> 2</td><td></td><td>mero-</td><td>mero-</td><td>mero-</td><td>wa * 4</td><td></td><td></td>

<td></td><td>RO</td><td></td><td></td><td>wa 1</td><td>wa 2</td><td>wa 3</td><td></td><td></td><td></td>

<td></td><td>you</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td></td><td> 1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td></td><td>LD</td><td>znLL</td><td>CBM</td><td></td><td></td><td></td><td></td><td>LDPE</td><td>Bimo</td>

<td></td><td>PE</td><td>DPE</td><td>B</td><td></td><td></td><td></td><td></td><td>from-</td><td>gave-</td>

<td></td><td> (1)</td><td> (2)</td><td> (3)</td><td></td><td></td><td></td><td></td><td>nies.</td><td>ny</td>

<td></td><td></td><td>(bi-</td><td></td><td></td><td></td><td></td><td></td><td></td><td>znLL</td>

<td></td><td></td><td>O-</td><td></td><td></td><td></td><td></td><td></td><td></td><td>DPE</td>

<td></td><td></td><td>gave-</td><td></td><td></td><td></td><td></td><td></td><td></td><td>from-</td>

<td></td><td></td><td>ny)</td><td></td><td></td><td></td><td></td><td></td><td></td><td>no-</td>

<td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>p.</td>

<td>ABOUT. %</td><td> 100</td><td> 100</td><td> 100</td><td>LDPE</td><td>LDPE</td><td>LDPE</td><td>LDPE</td><td>LDPE</td><td>znLL</td>

<td>wt.</td><td></td><td></td><td></td><td>(1) / z</td><td>(1) / z</td><td>(1) / z</td><td>(1) / z</td><td>refer-</td><td>DPE</td>

<td>composition</td><td></td><td></td><td></td><td>nLLD-</td><td>nLLD-</td><td>nLLD-</td><td>nLLD-</td><td>s./EVA</td><td>from-</td>

<td>speakers</td><td></td><td></td><td></td><td>PE</td><td>PE</td><td>PE</td><td>PE</td><td>/ CBMB</td><td>no-</td>

<td>in</td><td></td><td></td><td></td><td>(2) / C</td><td>(2) / C</td><td>(2) / C</td><td>(2) / C</td><td> (3)</td><td>s./C</td>

<td>com-</td><td></td><td></td><td></td><td>BMB</td><td>BMB</td><td>BMB</td><td>BMB</td><td> 88,0/5</td><td>BMB</td>

<td>positive</td><td></td><td></td><td></td><td> (3)</td><td> (3)</td><td> (3)</td><td> (3)</td><td> ,5/6,5</td><td> (3)</td>

<td>tion</td><td></td><td></td><td></td><td> 55,4/</td><td> 55,3/</td><td> 40,0/</td><td> 60,0/</td><td></td><td> 93,0</td>

<td>poly-</td><td></td><td></td><td></td><td> 37,5/</td><td> 37,5/</td><td> 53,0/</td><td> 33,0/</td><td></td><td> /7,0</td>

<td>mero-</td><td></td><td></td><td></td><td> 7,1</td><td> 7,2</td><td> 7,0</td><td> 7,0</td><td></td><td></td>

<td>input</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>mfr₂</td><td> 1</td><td> 0,2</td><td></td><td> 0,32</td><td> 0,35</td><td> 0,35</td><td> 0,59</td><td> 0,2</td><td> 0,85</td>

<td>ESCR (H)</td><td> 4</td><td></td><td></td><td>&gt; 2500 cont.</td><td>&gt; 2500 cont.</td><td> &gt;3200</td><td> 1300</td><td> &gt;1800</td><td> &gt;500 0</td>

<td>stress Zeni at rampion NIU (MPa)</td><td> 15</td><td> 28</td><td></td><td> 25,8</td><td> 25</td><td> 28</td><td> 23</td><td> &gt;15</td><td> 25</td>

<td>deformations łcenie at rampion NIU (%)</td><td> 600</td><td> 600</td><td></td><td> 830</td><td> 800</td><td> 790</td><td> 870</td><td> 600</td><td> 750</td>

<td>Density</td><td></td><td> 923</td><td></td><td> 927,4</td><td> 933</td><td> 932,5</td><td> 933,4</td><td> 931</td><td> 936</td>

<td>Module flexibility receivables (MPa)</td><td> 240</td><td> 370</td><td></td><td> 290</td><td> 300</td><td> 380</td><td> 325</td><td> 250</td><td> 400</td>

<td>SHI (2.7 /</td><td> 94</td><td> 36</td><td></td><td> 84</td><td> 90</td><td> 63</td><td> 69</td><td> 300</td><td> 26</td>

<td> 210)</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>SCB average arithmetic in Obsza sculpture valuations trowanym on 90% wt. MWD [CH3 / 1000T C]</td><td> 17</td><td> 15</td><td> 21</td><td> 19</td><td> 17</td><td> 17</td><td> 16</td><td> 18</td><td> 17</td>

<td>Minimum SCB in Obsza rank valuations valuable</td><td> 14</td><td> 11</td><td> 17</td><td> 17</td><td> 15</td><td> 14</td><td> 15</td><td> 14</td><td> 12</td>

<td>trowanym on 90% wt. [CH3 / 1000T C]</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Maximum SCB in Obsza sculpture valuations trowanym on 90% wt. [CH3 / 1000T C]</td><td> 21</td><td> 21</td><td> 31</td><td> 22</td><td> 19</td><td> 20</td><td> 19</td><td> 24</td><td> 21</td>

<td colspan="10">* not according to the invention</td>