WO2023052127A1

WO2023052127A1 - Pvc mixture

Info

Publication number: WO2023052127A1
Application number: PCT/EP2022/075517
Authority: WO
Inventors: Christian Ernst; Felix WALDRAB
Original assignee: Leoni Kabel Gmbh
Priority date: 2021-10-01
Filing date: 2022-09-14
Publication date: 2023-04-06
Also published as: DE102021125585A1; DE102021125585B4

Abstract

The present invention relates to a cable having a layer as defined in the claims, wherein the layer comprises alkoxyvinylsilane-modified polyvinyl chloride, alkoxyvinylsilane-modified halogen-free oligomers, polymers or combinations thereof as defined in the claims and a compatibilizer, wherein at least the alkoxyvinylsilane-modified components are crosslinked via siloxane bonds. The invention further relates to processes for producing a cable having a layer as defined in the claims.

Description

PVC blend

The present invention relates to a cable comprising a layer of PVC blend. Furthermore, the invention relates to a method for producing a cable which comprises this layer.

State of the art

Polyvinyl chloride (PVC) has been used in the manufacture of cables for many years, partly because of its low water absorption and flame-retardant properties. In a large number of applications for these cables - such as in the automotive sector - sufficient flexibility of the material at low temperatures is essential here in order to prevent the cable or the cable sheath from breaking. Since the thermoplastic PVC in its pure form (i.e. without additives, comonomers, soft phases, etc.) is a rigid and brittle material, monomeric plasticizers (monomer plasticizers?) such as phthalic acid esters of long-chain alcohols are used to ensure sufficient low-temperature flexibility at temperatures down to -40 to reach °C. The cold flexibility can be determined, for example, by testing using a cold wrap in accordance with ISO 19642 or by determining the glass transition temperature as a parameter.

The use of these monomer plasticizers is not without controversy and has various disadvantages. In the European Union in particular, these substances are viewed with increasing scrutiny due to their potentially mutagenic and environmentally harmful properties.

Furthermore, the use of only physically integrated, low-molecular-weight plasticizers in PVC, as well as in other polymers, results in further technical disadvantages that can have a negative impact on the usability.

The first thing to mention here is the lack of resistance of the resulting PVC compound to mineral oils: In typical oil aging tests according to Underwriters Laboratories (UL), test specimens are exposed to heated test oil (usually IRM 902 or 903), after which they must still have a defined residual elongation and residual tensile strength relative to the unaged baseline values exhibit. Since the test oil, which is chemically similar, dissolves the plasticizer from the PVC compound but does not have any flexibilizing properties itself, these tests become increasingly difficult or even impossible to pass with increasing duration and/or temperature if a system based solely on monomer plasticizers is to be used.

Furthermore, the monomer plasticizers, which are only physically bound and therefore capable of migration, limit the possible uses of the PVC compound in polymer composites, e.g. UL cables with a polyamide skin layer or in data cables with a polyolefinic dielectric. In the case of the latter in particular, the plasticizer migrates into the dielectric and, due to its polar nature, damages the transmission properties. In order to prevent this, barrier layers must therefore be introduced, which represents an additional process step and is therefore not only disadvantageous from an economic point of view.

Approaches to solving the problem described are, on the one hand, the use of polymeric plasticizers (polymer plasticizers) ¹ , such as polyesters of adipic acid (e.g. BASF Palamoll®), or the physical mixing in of compatible rubber phases, such as acrylates, acetates (e.g. DuPont Elvaloy® or also Acrylonitrile-butadiene rubbers, eg Omnova Chemigum®) In both cases, the migration properties of the plasticizers incorporated into the PVC are improved, ie reduced, but these are bought at the expense of a reduction in flexibility at low temperatures.

Due to their structure, polymeric plasticizers have a far less flexibilizing effect on the PVC matrix than monomeric plasticizers. With the same dosage, the glass transition temperature is up to 40°C higher. A similar problem arises when rubber phases are introduced: types of acrylonitrile butadiene rubber (nitrile butadiene rubber: NBR) that are physically sufficiently compatible with the PVC generally only have a glass transition temperature of -25°C. In addition, the actual PVC phase is not made more flexible, so monomer plasticizers have to be added. In addition, further technical problems arise from the use of only physically integrated soft phases. For example, resistance to media diffusion can be reduced due to internal interfaces, which is shown, for example, in the water storage test according to ISO 6722-1. WO 2019/072594 A1 describes a UV-curable hot-melt adhesive that is largely resistant to plasticizer migration and contains a UV-crosslinkable poly(meth)acrylate formed from methyl acrylate, C4-18 alkyl (meth)acrylate, monomer with acid groups, copolymerized photoinitiator and optionally others Monomers, wherein the hot melt adhesive also contains an aliphatic polyester polymer.

US 6,043,318 A describes a process for preparing a polyvinyl chloride/acrylonitrile butadiene rubber blend by a) coating a polyvinyl chloride resin with a stabilizer to form a precoated PVC, b) blending the precoated PVC with one or more acrylonitrile butadiene rubbers to form a pre-stabilized NBR/PVC blend, and c) applying heat and pressure to mix the pre-stabilized NBR/PVC blend into a flowable NBR/PVC blend.

In view of the above problems, there was therefore a need to provide an improved PVC composition which can be used as a layer in a cable, preferably for automotive applications.

Summary of the Invention

Cable having at least one layer, the layer comprising: a) 5-85% by weight, preferably 35-65% by weight polyvinyl chloride, b) 5-70% by weight, preferably 25-50% by weight halogen-free oligomers, Polymers, or combinations thereof, provided that the oligomers and polymers do not fall under the definition of component c), c) 5-50% by weight, preferably 5-10% by weight of a compatibilizer selected from esters with a molecular weight > 800 g/mol, halogenated polyolefins, polyvinyl chloride being excluded, modified acrylates and acetates or combinations thereof, characterized in that at least component a) and component b) are substituted by siloxane bonds -(CH2)2-Si-O-Si-( CH2)2- are crosslinked. The cables according to the invention comprehensively meet the diverse, previously mentioned requirements placed on cables by a special PVC layer. In the context of the present invention, it was surprisingly found that by combining a PVC modified with alkoxyvinylsilane groups and an oligomeric or polymeric soft phase containing alkoxyvinylsilane groups and having a sufficiently low glass transition temperature, a monomer-plasticizer-free PVC system can be built up with the aid of chemical bonding, which with sufficient low-temperature flexibility for automotive applications. The properties of the PVC system can be further improved by using an oligomeric or polymeric compatibilizer and plasticizing agent.

The different components of the system are connected in the same way as in the Sioplas® process, which is widespread in the cable industry, by aging in moist heat "sauna process". The Sioplas® process is a modification of a polymer (or a polymer system) in which a crosslinkable material is processed by crosslinking with water and elevated temperatures. In the presence of moisture, alkoxysilane groups (such as methoxysilane, ethoxysilane, etc.) hydrolyze under the influence of temperature with elimination of alcohols and form a network of siloxane bonds in a subsequent condensation reaction.

The hydrolysis of the alkoxysilane groups to form hydroxy groups can be complete, but alkoxy groups can also remain in the material. The successive crosslinking of the material can lead to steric inhibition of the subsequent hydrolysis and/or crosslinking reactions. In addition to the polymeric material, process parameters such as temperature, relative humidity or sample thickness, which in turn also determine the point in time at which water completely penetrates the material, can determine the course of the reaction. The basic reaction scheme for crosslinking via alkoxyvinylsilane-modified polymer is shown schematically in FIG. While FIG. 1 shows the condensation of two hydroxy groups (with elimination of H2O) which are formed by hydrolysis of the alkoxy groups, the condensation can also take place between a hydroxy group and an alkoxy group (with elimination of an alcohol). In the following, the condensation between completely hydrolyzed, i.e. between two -Si(OH)s groups is discussed. FIG. 1 shows schematically the reaction of two identical polymer chains. However, the crosslinking reaction can take place not only between identical polymer chains but also between any two or more alkoxyvinylsilane-modified components. Furthermore, a siloxane bond (siloxane single bridge) can be formed in the reaction, as shown in FIG - or triple bridging between two -Si(OH)3 groups, can arise as shown schematically below:

where is the linkage to the polymer/oligomer and can be RH, -CH3, or -C2H5.

Furthermore, in addition to the crosslinking of two (hydrolyzed) alkoxysilane groups, crosslinking of three or four alkoxysilane groups can also take place, one alkoxysilane group being crosslinked to two or three further alkoxysilane groups via siloxane bonds. The method can also be used for other polymers, such as PVC in the present case. The degree of crosslinking of the components depends on a variety of factors, such as reaction conditions (temperature, humidity), molecular weight of the components, type of silane, possible catalysts, sample thickness and shape, and others. A quantitative determination of the degree of crosslinking (crosslinked/uncrosslinked silane groups) can be carried out by Fourier transform infrared spectroscopy (FTIR), the degree of crosslinking being determined by the intensity of the bands for silanol (Si-OH), alkoxysilane (Si-OR) and siloxane (Si- O-Si) bonds can be determined. The expression "crosslinked by siloxane bonds" or "siloxane-crosslinked" as used herein describes a polymer system in which at least one, preferably part or all of the PVC chains with at least one, preferably part or all of the halogen-free oligomers, polymers , or combinations is crosslinked by at least one siloxane bond.

In addition to dispensing with monomer plasticizers with their above-described disadvantages, this process also unexpectedly results in improved thermomechanical behavior of the crosslinked PVC system, as shown, for example, by the so-called hot-set test in accordance with DIN EN 60811-2-1 or the sufficient Cold flexibility at low temperatures as required for automotive applications. Fatty acids and their esters, which are already used in PVC compounds, usually serve as crosslinking aids. It is not necessary to use organotin compounds that are potentially harmful to health, such as dioctyltin dilaurate (DOTDL).

Detailed description of the invention

The present invention relates to the following embodiments:

A cable having at least one layer, the layer comprising: a) 5-85% by weight, preferably 35-65% by weight polyvinyl chloride, b) 5-70% by weight, preferably 25-50% by weight halogen-free Oligomers, polymers, or combinations thereof, provided that the oligomers and polymers do not fall under the definition of component c), c) 5-50% by weight, preferably 5-10% by weight of a compatibilizer selected from esters having a molecular weight from

> 800 g/mol, halogenated polyolefins, polyvinyl chloride being excluded, modified acrylates and acetates or combinations thereof, characterized in that at least component a) and component b) are substituted by siloxane bonds -(CH2)2-Si-O-Si- (CH2)2- are crosslinked.

2. Cable according to embodiment 1, wherein the layer is made by crosslinking a composition, wherein the composition comprises: a) 5-85% by weight alkoxyvinylsilane-modified polyvinyl chloride, b) 5-70% by weight alkoxyvinylsilane-modified halogen-free oligomers, polymers , or combinations thereof, provided that the oligomers and polymers do not fall within the definition of component c), c) 5-50% by weight of a non-alkoxyvinylsilane-modified compatibilizer selected from esters having a molecular weight of

> 800 g/mol, halogenated polyolefins, where polyvinyl chloride excluding modified acrylates and acetates or combinations thereof, where alkoxyvinylsilane modification means that -(CH2)2-Si-(OR)3- groups are present, where R is selected from H, -CH3, and -C2H5.

3. Cable according to embodiment 1 or 2, characterized in that the layer comprises 15-70% by weight, preferably 35-65% by weight, of alkoxyvinylsilane-modified polyvinyl chloride.

4. Cable according to any one of the preceding embodiments, characterized in that the layer comprises 5-60% by weight, preferably 10-50% by weight, more preferably 25-50% by weight of component b).

5. Cable according to any one of the preceding embodiments, characterized in that the layer comprises 10-35% by weight, preferably 7-14% by weight, more preferably 5-10% by weight of the compatibiliser.

6. Cable according to any one of the preceding embodiments, characterized in that component b) is selected from homo- and copolymers of polyethylene, polypropylene, ethylene-propylene-diene rubber or silanes such as carbosilanes and polysiloxanes, and combinations of any two or several of them.

7. Cable according to any one of the preceding embodiments, characterized in that the compatibilizer is an adipic acid ester selected from poly(ethylene adipate), polybutylene adipate terephthalate (PBAT), poly(2-methyl-l,3-propylene adipate), poly(l ,4-butylene adipate), poly(1,4-butanediol/neopentyl glycol-altadipic acid), polyisononyl(1,4-butanediol-2,2-dimethyl-1,3-propanediol) adipate and combinations of any two or more of it is.

8. Cable according to any one of the preceding embodiments, characterized in that the layer further comprises fillers in an amount of 0.5-60% by weight, which fillers are preferably selected from carbonates, preferably calcium carbonate; silicates, preferably talc or kaolin; inorganic flame retardants, preferably aluminum hydroxide; and combinations thereof. 9. Cable according to any one of the preceding embodiments, characterized in that the layer further contains metal soaps present in an amount of up to 10% by weight, preferably 1-4% by weight, the metal soaps being preferably selected from dilaurates and Distearates of zinc, barium, calcium, magnesium, or combinations of any two or more thereof.

10. Cable according to any one of the preceding embodiments, characterized in that the layer further contains acid scavengers present in an amount of up to 18% by weight, preferably 1-8% by weight, the acid scavengers being preferably selected from aluminium /magnesium hydrotalcite, aluminium/magnesium/zinc hydrotalcite, calcium hydroxides, zeolite or combination of any two or more thereof.

11. Cable according to any one of the preceding embodiments, characterized in that the layer further contains phenolic antioxidants present in an amount of up to 4% by weight, preferably 0.25-2% by weight, the phenolic antioxidant being optionally selected are derived from ethylene bis(oxyethylene) bis(3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate), pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate), octadecyl [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2',3-bis[[3-[3,5-di-tert-butyl-4 - hydroxyphenyl]propionyl]]propionohydrazide and dialkyl esters of thiodipropionic acid.

12. Cable according to any one of the preceding embodiments, characterized in that the layer further comprises lubricants, the lubricants preferably being selected from fatty acids with a chain length of C8-C18, montan waxes and their esters, chlorinated paraffins with a chain length of C10- C30 and polyolefin waxes, and combinations of any two or more thereof.

13. Cable according to any one of the preceding embodiments, characterized in that the layer is free of organotin compounds, preferably free of organometallic compounds.

14. Cable according to any one of the preceding embodiments, characterized in that the layer is free from monomeric plasticizers with a molecular weight of 700 g/mol or less, the layer in particular is free from esters of trimellitic, orthophthalic, terephthalic, pyromellitic, adipic, sebacic, phosphoric and citric acid and their anhydrides with alcohols with a chain length of C2-C15.

15. Cable according to any one of the preceding embodiments, characterized in that the layer has phase transitions determined by dynamic mechanical analysis in the range from -25°C to -15°C and in the range from 25°C to 35°C, wherein the layer preferably has no further phase transitions in the range from -80°C to 100°C.

16. Cable according to any one of the preceding embodiments, characterized in that the layer has an elongation in the range of 20-30%, preferably 24-29%, determined by a hot-set test at 170° C. according to DIN EN 60811-507.

17. Cable according to any one of the preceding embodiments, characterized in that the layer has any one or more properties of the following: a) a volume resistivity of > 10 ⁹ Ohm-mm according to ISO 6722-1:2011, b) a low temperature -Winding test according to ISO 6722-1:2011 at -40°C without cracks, breaks or other structural impairments, c) a thermal stability of > 140 minutes according to LV112-1 2014-04, d) a hot water resistance of >10 ⁹ ohms- mm after 1000h at 85°C according to ISO 6722-1:2011, e) short-term aging Oat 130°C for 240h according to ISO 6722-1:2011 without cracks, fractures or other structural impairments, f) a hot set test at 150° C for 15 minutes according to DIN EN 60811-2-1 of <100%.

18. Cable according to any one of the preceding embodiments, wherein the layer is a primary insulation of an electrical conductor, and/or the jacket material for jacketing a plurality of cores.

19. A method of making a layer of cable comprising a) mixing i) 5-85% by weight alkoxyvinylsilane-modified polyvinyl chloride, ii) 5-70% by weight alkoxyvinylsilane-modified halogen-free oligomers, halogen-free polymers or combination thereof, provided that the oligomers and polymers do not fall under the definition of component iii), and iii) 5-50% by weight of a non-alkoxyvinylsilane-modified compatibilizer selected from esters, halogenated polyolefins, with the exception of polyvinylchloride, modified acrylates and acetates or combinations thereof with a molecular weight >800 g/mol, where alkoxyvinylsilane means modification that - (Cl-h)?- Si-(OR)s groups are present, where R is selected from H, -CH3, and -C2H5, b) extruding the mixture obtained in point a) as a layer of a cable, c) Crosslinking of the mixture obtained in point b) at a temperature of at least 20°C, preferably >60°C and a relative humidity of at least 50%, preferably >85%, with at least components i) and ii) crosslinking through siloxane bonds become.

20. The method according to embodiment 19, characterized in that the crosslinking by water storage at a temperature of 70 ° C to 95 ° C, preferably 80 ° C to 90 ° C, for a period of 8 to 48 hours, preferably 12 to 36 hours , more preferably 18 to 30 hours, or for a period of 24 hours at 85 ° C.

21. Use of a composition in the manufacture of a cable or as a layer in a cable, wherein the composition is applied as a layer to cable strands or core ropes by sheath extrusion and is subsequently crosslinked by aging in moist heat to form siloxane bonds, the composition comprising: a) alkoxyvinylsilane-modified polyvinyl chloride in an amount of 5-85% by weight, b) alkoxyvinylsilane-modified halogen-free oligomers, halogen-free polymers or combinations thereof, in an amount of 5-70% by weight %, provided that the oligomers and polymers do not fall under the definition of component c), and c) a compatibilizer selected from esters with a molecular weight > 800 g/mol, halogenated polyolefins, with the exception of polyvinyl chloride, modified acrylates and acetates or combinations thereof, in an amount of 5-50% by weight.

The above-mentioned embodiments and further embodiments, all of which can be combined with one another, are described in more detail below.

The cable according to the invention has at least one layer as described above.

The term "cable", as used here and in electrical engineering and information technology in general, refers to a single or multi-core composite of cores (individual lines) sheathed in insulating materials, which is used to transmit energy or information. Insulating materials from cables are preferred Polymers with properties corresponding to the application. The cable comprises at least one layer as defined in the claims. In addition to this layer, the cable can also comprise additional layers. Further layers can be conductive layers, insulating layers, sliding layers, separating layers, lacquer layers, textile carrier layers and others.

The term "polymer" as used herein refers to molecules having a high number of repeating units (monomers) linked together. One type of polymer (e.g. the "first polymer") differs from another type of polymer (e.g. the "second polymer") by the type of monomers. The term "copolymer" as used herein refers to a polymer having more than one type of monomers.

The term "oligomer", as used herein, refers to molecules that are made up of several structurally identical or similar units, whereby, in contrast to polymers, a small change in the number of units already causes a significant change in properties. Typically, the molecular weight of oligomers smaller than 10 kDa (10,000 u). The term "weight percent" and its variations (e.g., "wt%", wt%, etc.) refers to the total weight of the composition of the layer that is part of the cable.

The term "alkoxyvinylsilane-modified polyvinyl chloride", as used herein, refers to a polymer of vinyl chloride (polyvinyl chloride) modified with alkoxyvinylsilane. Silane-modified polymers can be prepared in two different ways, among others: grafting of vinylsilane monomers onto the polymer, or Copolymerization of these compounds with the monomer (e.g. vinyl chloride).

In the case of the former, vinyltrimethoxysilane (VTMS), vinyltriethoxysilane (VTES) or other vinylalkoxysilanes can be used as the modifying monomer. VTMS and VTES are preferably used. These molecules can be attached to the backbone of the polymer (such as PVC) via a free radical mechanism, for example. The silane group can be grafted onto the PVC or the PVC can be modified with the silane group in different ways. In industrial applications, among other things, the grafting in the melt using peroxides as the initiator of the free-radical mechanism has become established. Furthermore, silane-modified polymers can be prepared by copolymerizing vinyl silane together with other monomers (such as vinyl chloride). Furthermore, amino(alkoxy)silanes such as, for example, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane or N-(2-aminoethyl)-3-aminopropyltriethoxysilane can be grafted onto PVC by nucleophilic substitution.

The expression "alkoxyvinylsilane-modified halogen-free oligomers, polymers or combinations thereof", as used herein, refers to polymers, oligomers and mixtures of both, which - as previously described for PVC - are modified with alkoxyvinylsilane. Preferably used are homo- and copolymers of polyethylene (PE), polypropylene (PP), polybutylene (PB), polyisobutene (PIB), polyhexene (PH), polyoctene (PO), polydecene (PDC) and polyoctadecene (PODC), polystyrene (PS), ethylene-propylene diene rubber (EPDM) and silanes.

The amount of alkoxyvinylsilane used for modification can vary depending on the properties that the modified and crosslinked product is to have. The amount may range from 0.5 to 5.0% by weight based on the weight of the polymer or oligomer, preferably in a range of 0.5 to 2.5% by weight, more preferably in a range of 1.0 to 2.0% by weight based on the weight of the polymer or oligomer.

The term "compatibilizer" as used herein refers to one or more additives that can be added to polymers, copolymers and polymer blends to reduce the interfacial tension between different phases. Compatibilizers thus reduce the tendency for chemically different components to segregate, thereby allowing an additionally improved The compatibilizers are preferably organic compounds, in particular plasticizers based on adipic acid esters with a molar mass >800 g/mol, halogenated polyolefins, in particular halogenated PE, modified acrylates and acetates or combinations of any two or more of these.

The components of the layer and the layer itself can be characterized, for example, by nuclear magnetic resonance spectroscopy (NMR). Using NMR, signals in the spectrum can be assigned to specific atoms or to the same atoms in chemically or sterically different environments. Since NMR spectra are influenced by local interactions, the method allows conclusions to be drawn about the structure of monomeric, oligomeric or polymeric compounds by shifting the signals in the spectrum. Furthermore, statements about the degree of halogenation or crosslinking in the components can be made by quantitative evaluation of the NMR spectra. The work "Identification of different structures formed during crosslinking of polyethylene with vinyl triethoxysilane FTIR Si ²⁹ NMR and XPS sudy" by Fuzail et al. (The Nucleus 48, No. 1 (2011) 1-9), for example, examines the effect of the silane and peroxide concentration on the types of various structures or grafts formed during crosslinking.FTIR spectra show that the asymmetric Si-O-Si stretch and the Si-C stretch are in the general range of 1000-1130 and 735, respectively -800 cm-1 were observed.Theoretical and experimental band assignments for Si ²⁹ NMR spectra indicate the presence of different fragments based on T°, T ¹ , T ² and T ³ structures.It was found that at the maximum silane concentration, the predominant form of crosslinking is ^T3 , ie, trioxygenated silane with three silane bridges XPS analysis also confirms the presence of a variety of C, O, and Si bonds in the silane crosslinked polyethylene that have different elemental ratios. Plasticizers based on adipic acid esters with a molar mass > 800 g/mol can be used as compatibilizers in the cable layer. Esters such as poly(ethylene adipate), polybutylene adipate terephthalate (PBAT), poly(2-methyl-1,3-propylene adipate), poly(1,4-butylene adipate), poly(1,4-butanediol/neopentyl glycol) can be used -alt-adipic acid), and combinations of any two or more thereof.

The compatibilizers can also be selected from halogenated olefins such as chlorinated hydrocarbons, brominated hydrocarbons or fluorocarbons, and are preferably elastomeric compounds. In addition to halogenated polyethylene, halogenated polypropylene, polybutylene, polyisobutene, polyhexene, polyoctene, polydecene and polyoctadecene can be used. Halogenated polyethylene is preferably used. The halogenated polymers or olefins, with the exception of PVC, are preferably produced by post-chlorination of polymers or olefins in a separate process step.

The compatibilizers can be selected from modified acrylates and modified acetates. Modified acrylates can be used, including methyl acrylate, ethyl acrylate, n-propyl acrylate, butyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, isobornyl acrylate, cyclododecyl acrylate, chloromethyl acrylate, 2-chloroethyl acrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 2,3, 4,5,6-pentahydroxyhexyl acrylate, 2,3,4,5-tetrahydroxypentyl acrylate, ethyl methacrylate (MMA), ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethyl hexyl methacrylate, lauryl methacrylate, isobornyl methacrylate, cyclododecyl methacrylate, chloromethyl methacrylate, 2-chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 2,3,4,5,6-pentahydroxyhexyl methacrylate, 2,3,4,5-tetrahydroxypentyl methacrylate. Preferred acrylates are ethylene acetate and ethylene acrylate copolymers and modifications thereof. The copolymers can also contain N-butyl, CO blocks and other copolymerizable units, as well as ethylene/n-butyl acrylates and their copolymers with carbon monoxide.

Modified acetates include ethylene vinyl acetate copolymer,

ethylene vinyl acetate copolymer, ethylene vinyl acetate terpolymer, polyvinyl acetate ethylene vinyl acetate/carbon dioxide copolymers. The term "fillers", as used herein, describes substances that can be added to the layer of the cable. Fillers that can be added include glass fibers, glass beads, mineral fillers, carbon fiber, carbon black, chalk, wood fibers, wood powder, dried apple powder, kaolin , and magnesium dihydroxide (MDH), and carbonates, silicates, flame retardants, Inorganic carbonates, preferably calcium carbonate, inorganic silicates, preferably talc or kaolin, or inorganic flame retardants, preferably aluminum hydroxide or combinations thereof, can preferably be used.

The term "metallic soaps" as used herein describes salts of fatty acids and salts of rosin and naphthenic acids with metals to the exclusion of the sodium and potassium salts. Preferably, metallic soaps of laurate, stearate, and combinations thereof are used. Preferably, zinc, barium, - Calcium or magnesium salts, as well as combinations of any two or more of these are used.

The term "acid scavenger", as used herein, describes basic substances that are used to neutralize traces of acids in polymers and polymer-containing materials, which are, for example, from catalyst residues in the material. Hydrotalcite comprising aluminum and magnesium are preferably used as acid scavengers , Hydrotalcite including aluminum, magnesium and zinc, calcium hydroxides, zeolites and combinations of any two or more thereof used.

The expression "phenolic antioxidants", as used herein, describes free-radical scavengers, which means substances that can be added to the layer of the cable in order to protect it from undesirable oxidative aging processes or to delay aging. In polymer materials, processes take place whose irreversible effects collectively referred to as "aging phenomena". In addition to the polymers, pigments, fillers, reinforcing materials and various additives are also involved. Physical aging is initially noticeable in the form of embrittlement. It is caused, in particular, by long-term use at temperatures slightly below the melting or glass transition point of the polymers. Like all organic materials, natural and synthetic polymers react readily with oxygen. The mechanical and optical properties deteriorate in the process the plastic parts made from it. However, degradation and aging can be suppressed or at least delayed. One way to do this is to modify the chemical structure of the polymers, e.g. B. by incorporating more stable comonomers or by blocking reactive end groups. However, the use of suitable stabilizers (antioxidants) is more common because it can be applied more comprehensively. Preference is given to using sterically hindered phenols such as those from the Irganox® group.

The term "lubricant", as used herein, describes substances that can be added to the cable or the layer to reduce the mechanical stress between the individual components of the cable. Lubricants are divided into internal and external lubricants. The transitions are fluid - internal lubricants show often a certain external lubricating effect and vice versa. Lubricants with both effects are referred to as "combined". Internal lubricants reduce the frictional forces occurring between the PVC molecular chains and thus lower the melt viscosity. They are polar and have a high level of compatibility with PVC. Even with high dosages, they provide excellent transparency and do not tend to exude, which optimizes welding, gluing and printing. External lubricants reduce adhesion between PVC and metal surfaces. They are mostly non-polar, examples of which are paraffins and polyethylenes. The external lubricating effect is influenced by the length of the hydrocarbon chain, its branching and the functional group. High dosages can lead to clouding and exudation effects. Preference is given to using lubricants selected from fatty acids (in particular lauric acid and stearic acid), montan waxes and their esters, chlorinated paraffins, and oxidized and non-oxidized polyolefin waxes. Montan wax describes a black-brown, hard, brittle, fossil vegetable wax, which is extracted from bituminous types of lignite. Chlorinated paraffins are substance mixtures of polychlorinated, saturated, unbranched hydrocarbons with 10-30 carbon atoms, which correspond to the general molecular formula C _x H(2x- _y +2)Cl _y . They can be produced by the chlorination of n-alkanes, resulting in complex mixtures of different chloroalkanes. The degree of chlorination can vary between 30 and 70% by weight. Polyolefin wax describes a mixture of hydrocarbons having a melting point between about 30°C and 60°C which when molten forms a low viscosity liquid. Preferred waxes are polyethylene wax, polypropylene wax, and mixtures thereof. The layer of the cable may be free of organotin (such as dioctyltin dilaurate), preferably free of organometallic compounds. Organometallic compounds contain a metal atom bonded to a carbon atom. Organometallic compounds may contain Group 1 alkali metals, Group 2 alkaline earth metals, Groups 3-12 transition metals and Groups 13-15 elements, as well as metalloids such as boron and silicon. Organometallic compounds are used, among other things, as catalysts in polymerisation and often remain in the finished polymer after polymerisation. In addition to polymerization per se, organometallic compounds are also used as catalysts in the subsequent crosslinking of polymers. However, a large number of the organometallic compounds used are harmful or potentially harmful to health, such as dioctyltin dilaurate or dibutyltin dilaurate. Due to the combination of alkoxyvinylsilane-modified polyvinyl chloride and alkoxyvinylsilane-modified, halogen-free oligomers and polymers as the soft phase, which are crosslinked by condensation reactions, it is not necessary to use organometallic compounds such as dioctyltin dilaurate (DOTDL).

The layer of the cable can be free of monomeric plasticizers such as mono-, di-, and triglycerides of fatty acids. The layer is preferably free of monomeric plasticizers with a molecular weight of 700 g/mol or less. Monomeric softeners such as phthalic acid esters of long-chain alcohols have been criticized because their effect is similar to that of certain hormones. Preferably, the layer of the cable is free from monomeric plasticizers such as ASE (Cio-C2i) phenyl alkanesulfonate, BAR butyl O-acetylricinoleate,

BBP benzyl butyl phthalate,

BCHP butyl cyclohexyl phthalate,

BNP butyl nonyl phthalate,

BOA benzyl octyl adipate,

BOP butyl octyl phthalate,

BST butyl stearate,

DBA dibutyl adipate,

DBEP di-2-butoxyethyl phthalate,

DBF dibutyl fumarate,

DBM dibutyl maleate, DBP dibutyl phthalate, DBS dibutyl sebacate, DBZ dibutyl azelate, DCHP dicyclohexyl phthalate, DCP dicapryl phthalate, DDP didecyl phthalate, DEGDB diethylene glycol dibenzoate, DEP diethyl phthalate, DHP diheptyl phthalate, DHXP dihexyl phthalate, DIBA diisobutyl adipate, DIBM diisobutyl maleate, DIBP diisobutyl phthalate,

DIDA diisodecyl adipate, DIDP diisodecyl phthalate, DIHP diisoheptyl phthalate, DIHXP diisohexyl phthalate, DINA diisononyl adipate, DINP diisononyl phthalate, DIOA diisooctyl adipate, DIOM diisooctyl maleate, DIOP diisooctyl phthalate, DIOS diisooctyl sebacate, DIOZ diisooctyl azelate, DIPP diisopentyl methyloxyethyl phthalate, DMEP diisopentyl phthalate, DMEP

DMP dimethyl phthalate, DMS dimethyl sebacate, DNF dinonyl fumarate, DNM dinonyl maleate, DNOP di-n-octyl phthalate, DNP dinonyl phthalate, DNS dinonyl sebacate, DOA dioctyl adipate, DOIP dioctyl isophthalate, DOP dioctyl phthalate, DOS dioctyl sebacate, DOTP dioctyl terephthalate,

DOZ dioctyl azelate,

DPCF diphenyl cresyl phosphate,

DPGDB di-x-propylene glycol dibenzoate,

DPOF diphenyloctyl phosphate,

DPP diphenyl phthalate,

DTDP diisotridecyl phthalate,

DUP diundecyl phthalate,

ELO epoxidized linseed oil,

ESO epoxidized soybean oil,

GTA glycerol triacetate,

HNUA heptyl nonyl undecyl adipate,

HNUP heptyl nonyl undecyl phthalate,

HXODA hexyloctyldecyl adipate,

HXODP hexyloctyldecyl phthalate,

NBBS N-butylbenzenesulfonamide,

NUA nonyl undecyl adipate,

NUP nonyl undecyl phthalate,

ODA octyldecyl adipate,

ODP Octyldecyl Phthalate,

ODTM n-octyldecyl trimellitate,

PO paraffin oil,

PPA polypropylene adipate,

PPS polypropylene sebacate,

SOA sucrose octaacetate,

TBAC tributyl O-acetyl citrate,

TBEP tri-2-butoxyethyl phosphate,

TBP tributyl phosphate,

TCEF trichloroethyl phosphate,

TCF tricresyl phosphate,

TDBPP Tris(2,3-dibromopropyl)phosphate,

TDCPP Tris(2,3-dichloropropyl)phosphate,

TEAC triethyl O-acetyl citrate,

THFO tetrahydrofurfuryl oleate,

THTM triheptyl trimellitate,

TIOTM triisooctyl trimellitate,

TOF trioctyl phosphate, TO PM tetraoctyl pyromellitate,

TOTM trioctyl trimellitate,

TPP triphenyl phosphate,

TXF trixylylene phosphate.

Dynamic mechanical analysis (DMA) is a method for determining the viscoelastic properties, primarily of polymer materials. For example, elastomers are very stiff below the glass transition temperature (Tg) and have a high modulus of elasticity. Above the Tg they are flexible and cushioning. DMA measures viscoelastic properties during a controlled temperature and/or frequency program. During the test, a sinusoidal force (stress o) is applied to the sample (input). This in turn results in a sinusoidal deformation (elongation E; exit). Certain materials, such as polymers, exhibit viscoelastic behavior, that is, they exhibit both elastic (corresponding to a spring) and viscous properties (corresponding to an ideal damper). Because of this viscoelastic behavior, the corresponding stress and strain curves are shifted. Thus, the presence of a phase transition in polymeric materials can be determined by DMA.

Due to the combination of alkoxyvinylsilane-modified polyvinyl chloride and alkoxyvinylsilane-modified halogen-free oligomers or polymers, which are crosslinked by siloxane bonds, phase transitions determined by DMA in the range from -25°C to -15°C (pure soft phase), 45° appear C to 55°C (crosslinking range of both components, as well as 85°C to 95°C (pure PVC phase).

The addition of the compatibilizer in the layer results in a common area of the phase transition of the PVC phase and the crosslinking phase. Preferably, the layer of the cable is characterized in that this layer with compatibilizer has a phase transition in the range from -25°C to -15°C and in the range from 25°C to 35°C. The layer particularly preferably has no further phase transitions in the range from -80.degree. C. to 100.degree. The absence of further phase transitions in the material indicates that after crosslinking there is no longer pure PVC and no pure crosslinked area in the material. The "Hot Set" test is a simple means of determining whether the material used in the insulation or jacketing (e.g. of cables) has been sufficiently crosslinked. A crosslinked material is a material that has been modified to allow the bonding between the polymer chains When cross-linking insulation and sheathing materials, it is usually done to improve mechanical and electrical properties.

The hot set test for crosslinked materials can be carried out in accordance with DIN EN 60811-2-1, for example. The recognized test methods are intended to be referenced in cable construction and cable material standards. The hot set test is performed on the insulation or jacket material and not on the complete cable. The first step, therefore, is to prepare the cable sample by removing the conductors and any braid, armor or tape. Depending on the cross-sectional size and shape of the entire cable, samples are either cut as a tubular disc or cut into smooth, dumbbell-shaped pieces. The central 20mm (or 10mm for smaller samples) are marked by two lines. In addition to an oven capable of maintaining the required temperature within specified tolerances, the test method requires handles with attachable weights.

Failure in the Hot Set Test indicates that a polymeric material is not sufficiently crosslinked. The layer of the cable is preferably as defined in the claims, characterized in that the hot-set test at 170°C according to DIN EN 60811-507 has an elongation in the range of 20-30%, preferably 24-29%.

Furthermore, the cable as defined in the claims is characterized in that the layer has a volume resistance of > 10 ⁹ Ohm-mm according to ISO 6722-1:2011, a low-temperature winding according to ISO 6722-1:2011 at -40°C without cracks, fractures or other structural impairments, a thermal stability of > 140 minutes according to LV112-1 2014-04, a resistance to hot water of >10 ⁹ ohm-mm after 1000h at 85°C according to ISO 6722-1:2011, short-term aging at 130°C for 240h according to ISO 6722-1:2011 without cracks, fractures or other structural impairments, a hot set test at 150°C for 15 minutes according to DIN EN 60811-2-1 of <100%. In addition, the present invention also relates to a method for producing a layer of a cable. The process as defined in the claims comprises: a) mixing i) 5-85% by weight alkoxyvinylsilane-modified polyvinyl chloride, ii) 5-70% by weight alkoxyvinylsilane-modified halogen-free oligomers, halogen-free polymers or combination thereof, provided that that the oligomers and polymers do not fall under the definition of component iii), and iii) 5-50% by weight of a non-alkoxyvinylsilane-modified compatibilizer selected from esters, halogenated polyolefins with the exception of polyvinyl chloride, modified acrylates and acetates or combinations thereof with a molar mass of > 800 g/mol, where alkoxyvinylsilane modification means that - (CH2)2-Si-(OR)s groups are present, where R is selected from H, -CH3, and -C2H5, b) Extruding the mixture obtained in point a) as a layer of a cable, c) crosslinking the mixture obtained in point b) at a temperature of at least 20°C, preferably >60°C and a relative humidity of at least 50%, preferably >85% at least components i) and ii) being crosslinked by siloxane bonds.

In addition to extrusion, the mixture in step b) can also be processed by injection molding or other methods known to those skilled in the art. Furthermore, the material can be processed as cable auxiliary equipment (gaskets, strain reliefs and others) by these methods. The crosslinking step c) can in principle take place at any desired temperature and atmospheric humidity which is suitable for enabling the crosslinking reaction. Preferably the process is as defined in the claims, characterized in that the crosslinking is carried out by water storage at a temperature of 70°C to 95°C, preferably 80°C to 90°C, for a period of 8 to 48 hours, preferably 12 to 36 hours, more preferably 18 to 30 hours, or for a period of 24 hours at 85°C. Furthermore, the crosslinking step can take place in a water bath. Furthermore, the present invention relates to a layer of a cable obtained by or obtainable by mixing, extruding and crosslinking the components comprising a) alkoxyvinylsilane-modified polyvinyl chloride in an amount of 5-85% by weight, b) alkoxyvinylsilane-modified halogen-free oligomers, halogen-free polymers or Combination thereof provided that the oligomers and polymers do not fall within the definition of component c) in an amount of 5-70% by weight, and c) a compatibilizer selected from esters having a molecular weight of

> 800 g/mol, halogenated polyolefins, with the exception of polyvinyl chloride, modified acrylates and acetates or combinations thereof, in an amount of 5-50% by weight.

Preferably, the extrusion is done using mixing elements. This results in the distribution of dyes, microbubbles or other components becoming more homogeneous if they are added.

The crosslinking is preferably carried out by a process similar to the Sioplas® process or the sauna process. This means that the silanol groups are preferably crosslinked by aging in moist (non-condensed or condensed) heat or in hot water.

While the layer of the cable preferably comprises a compatibilizer as described above in addition to the alkoxyvinylsilane modified components, the present invention is not so limited. Furthermore, the present invention relates to a cable with a layer comprising the alkoxyvinylsilane-modified components as described above, wherein at least these are crosslinked by siloxane bonds.

In another embodiment, the present invention relates to a cable having at least one layer, the layer comprising: a) 5-85% by weight polyvinyl chloride, b) 5-70% by weight halogen-free oligomers, polymers, or combinations thereof, characterized in that component a) and component b) are crosslinked by siloxane bonds -(CH2)2-Si-O-Si-(CH2)2-. In another embodiment, the present invention relates to a cable having at least one layer, wherein the layer is made by crosslinking a composition, wherein the composition comprises: a) 5-85% by weight alkoxyvinylsilane-modified polyvinyl chloride, b) 5-70 % by weight of alkoxyvinylsilane-modified halogen-free oligomers, polymers, or combinations thereof, where alkoxyvinylsilane modification means that -(CH2)2-Si-(OR)3- groups are present, where R is selected from H, -CH3, and -C2H5, characterized in that at least component a) and component b) are crosslinked in the layer by siloxane bonds -(CH2)2-Si-O-Si-(CH2)2-.

Preferably, the alkoxyvinylsilane-modified halogen-free oligomer is selected from homo- and copolymers of polyethylene, polypropylene, polybutylene, polyisobutene, polyhexene, polyoctene, polydecene and polyoctadecene, polystyrene, ethylene-propylene-diene rubber and silanes, and combinations of any two or more of that.

In a further embodiment, the present invention also relates to a method for producing a layer of a cable. The process comprises: a) mixing i) 5-85% by weight alkoxyvinylsilane-modified polyvinyl chloride, ii) 5-70% by weight alkoxyvinylsilane-modified halogen-free oligomers, halogen-free polymers or combination thereof and b) extruding the ones obtained in point a). Mixture as a layer of a cable, c) crosslinking of the mixture obtained in point b) at a temperature of> 60 ° C and a relative humidity of> 85%, wherein at least components i) and ii) by siloxane bonds - (CH2) 2 -Si- O-Si-(CH2)2- can be crosslinked.

Furthermore, the invention relates to the following embodiments: A cable having at least one layer, the layer comprising: a) 5-85% by weight, preferably 35-65% by weight polyvinyl chloride, b) 5-70% by weight, preferably 25-50% by weight halogen-free Oligomers, polymers, or combinations thereof, provided that the oligomers and polymers do not fall under the definition of component c), characterized in that at least component a) and component b) are linked by siloxane bonds -(CH2)2-Si-O -Si-(CH2)2- are crosslinked.

2. Cable according to embodiment 1, wherein the layer is made by crosslinking a composition, wherein the composition comprises: a) 5-85% by weight alkoxyvinylsilane-modified polyvinyl chloride, b) 5-70% by weight alkoxyvinylsilane-modified halogen-free oligomers, polymers , or combinations thereof, wherein alkoxyvinylsilane modification means that -(CH2)2-Si-(OR)3- groups are present, where R is selected from H, -CH3, and -C2H5.

5. Cable according to any one of the preceding embodiments, characterized in that component b) is selected from homo- and copolymers of polyethylene, polypropylene, ethylene-propylene-diene rubber or silanes such as carbosilanes and polysiloxanes, and combinations of any two or several of them.

6. Cable according to any one of the preceding embodiments, characterized in that the layer further contains metal soaps present in an amount of up to 10% by weight, preferably 1-4% by weight, the metal soaps being preferably selected from dilaurates and distearates of zinc, barium, calcium, magnesium, or combinations of any two or more thereof.

7. Cable according to any one of the preceding embodiments, characterized in that the layer further contains acid scavengers present in an amount of up to 18% by weight, preferably 1-8% by weight, the acid scavengers being preferably selected from aluminium /magnesium hydrotalcite, aluminium/magnesium/zinc hydrotalcite, calcium hydroxides, zeolite or combination of any two or more thereof.

8. Cable according to any one of the preceding embodiments, characterized in that the layer further contains phenolic antioxidants present in an amount of up to 4% by weight, preferably 0.25-2% by weight, the phenolic antioxidant being optionally selected are derived from ethylene bis(oxyethylene) bis(3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate), pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate), octadecyl [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2',3-bis[[3-[3,5-di-tert-butyl-4 - hydroxyphenyl]propionyl]]propionohydrazide and dialkyl esters of thiodipropionic acid.

9. Cable according to any one of the preceding embodiments, characterized in that the layer further comprises lubricants, wherein the lubricants are preferably selected from fatty acids with a chain length of C8-C18, montan waxes and their esters, chloroparaffins with a chain length of C10- C30 and polyolefin waxes, and combinations of any two or more thereof.

10. Cable according to any one of the preceding embodiments, characterized in that the layer is free of organotin compounds, preferably free of organometallic compounds.

11. Cable according to any one of the preceding embodiments, characterized in that the layer is free from monomeric plasticizers with a molecular weight of 700 g/mol or less, the layer in particular being free from esters of trimellitic, orthophthalic, terephthalic, pyromellitic -, Adipic, sebacic, phosphoric and citric acid and their anhydrides with alcohols with a chain length of C2-C15. 12. Cable according to any one of the preceding embodiments, characterized in that the layer has phase transitions determined by dynamic mechanical analysis in the range from -25°C to -15°C and in the range from 25°C to 35°C, wherein the layer preferably has no further phase transitions in the range from -80°C to 100°C.

13. Cable according to any one of the preceding embodiments, characterized in that the layer has an elongation in the range of 20-30%, preferably 24-29%, determined by a hot-set test at 170° C. according to DIN EN 60811-507.

14. Cable according to any one of the preceding embodiments, characterized in that the layer has any one or more properties of the following: a) a volume resistivity of > 10 ⁹ Ohm-mm according to ISO 6722-1:2011, b) a low temperature -Winding test according to ISO 6722-1:2011 at -40°C without cracks, breaks or other structural impairments, c) a thermal stability of > 140 minutes according to LV112-1 2014-04, d) a hot water resistance of >10 ⁹ ohms- mm after 1000h at 85°C according to ISO 6722-1:2011, e) short-term aging Oat 130°C for 240h according to ISO 6722-1:2011 without cracks, fractures or other structural impairments, f) a hot set test at 150° C for 15 minutes according to DIN EN 60811-2-1 of <100%.

15. Cable according to any one of the preceding embodiments, wherein the layer is a primary insulation of an electrical conductor, and/or the jacket material for jacketing a plurality of cores.

16. A method of making a layer of cable comprising a) mixing i) 5-85% by weight of alkoxyvinylsilane-modified polyvinyl chloride, ii) 5-70% by weight of alkoxyvinylsilane-modified halogen-free oligomers, halogen-free polymers or combination thereof, and wherein alkoxyvinylsilane modification means that - (Cl-h)?-Si-(OR)s- groups are present, where R is selected is composed of H, -CH3, and -C2H5, b) extruding the mixture obtained in point a) as a layer of a cable, c) crosslinking the mixture obtained in point b) at a temperature of at least 20°C, preferably >60°C and a relative humidity of at least 50%, preferably >85%, with at least components i) and ii) being crosslinked by siloxane bonds.

17. The method according to embodiment 16, characterized in that the crosslinking by water storage at a temperature of 70 ° C to 95 ° C, preferably 80 ° C to 90 ° C, for a period of 8 to 48 hours, preferably 12 to 36 hours , more preferably 18 to 30 hours, or for a period of 24 hours at 85 ° C.

18. Use of a composition in the manufacture of a cable or as a layer in a cable, wherein the composition is applied as a layer to cable strands or core ropes by sheath extrusion and is subsequently crosslinked by aging in moist heat to form siloxane bonds, the composition comprising: a) alkoxyvinylsilane-modified polyvinyl chloride in an amount of 5-85% by weight, b) alkoxyvinylsilane-modified halogen-free oligomers, halogen-free polymers or combination thereof in an amount of 5-70% by weight, provided that the oligomers and polymers do not fall within the definition of component c), and

In another embodiment, the present invention relates to a composition comprising: a) 5-85% by weight alkoxyvinylsilane-modified polyvinyl chloride, b) 5-70% by weight alkoxyvinylsilane-modified halogen-free oligomers, polymers, or combinations thereof, and optionally c) 5-50% by weight of a non-alkoxyvinylsilane-modified compatibilizer, selected from esters with a molar mass of >800 g/mol, halogenated polyolefins, where alkoxyvinylsilane modification means that -(CH2)2-Si-(OR) 3- groups are present, where R is selected from H, -CH3, and -C2H5, characterized in that at least component a) and component b) in the layer are substituted by siloxane bonds -(CH2)2-Si-O-Si -(CH2)2- are crosslinked.

examples

Example 1: Experiments on the phase structure of a cable as defined in the claims

A cable comprising a layer as defined in the claims can be manufactured as defined in the claims. The layer of the tested cable according to the claims has the following components:

There is a clear difference in the behavior of the phase transitions, determined by DMA, between a combination of alkoxyvinylsilane-modified PVC with an incompatible or compatible, alkoxyvinylsilane-modified, polymeric soft phase (hereinafter "silane-modified"). In the first case, the two separate transition points of the soft phase and PVC are also visible after crosslinking, and a segregated system is formed. This hypothesis is also supported by a complete failure in the hot-set test: The two separate phases can be crosslinked in themselves, but the introduced tensile energy cannot be transferred across the phase interfaces, especially at elevated temperatures, and failure occurs.

In contrast, the system with a compatible, silane-modified soft phase shows a reduction in the number of transition regions from four before crosslinking to three after crosslinking. This results in the structure of a block copolymer with a pure PVC phase (transition temperature 91°C), a pure soft phase (transition temperature -21°C) and a crosslinking area (transition temperature 52°C). Here the hot-set test is passed in 2/3 of the cases. A further improvement results from the introduction of the compatibilizer. A common phase transition for the crosslinking area and the PVC phase can be seen here at a comparatively lower temperature (31°C). We passed the hot-set test in all cases.

Table 1 Transition temperatures according to dynamic mechanical analysis

(DMA) and corresponding results from the hot-set test for combinations of alkoxysilane-modified PVC with various Siian-modified soft phases.

Example 2: Tests on the thermomechanical behavior of a cable as defined in the claims

It turns out that a cable comprising at least one layer as defined in the claims fulfills both the thermomechanical and the electrical requirements.

Literature:

- WO 2019/072594 A1 - US 6,043,318 A

Claims

- 32 - Claims

> 800 g/mol, halogenated polyolefins, with the exception of polyvinyl chloride, modified acrylates and acetates or combinations thereof, characterized in that at least one, preferably a part or all of the polyvinyl chloride chains of component a) with at least one, preferably a part or all of component b) is crosslinked by siloxane bonds -(CH2)2-Si-O-Si-(CH2)2-.

The cable of claim 1, wherein the layer is made by crosslinking a composition, the composition comprising: a) 5-85% by weight alkoxyvinylsilane-modified polyvinyl chloride, b) 5-70% by weight alkoxyvinylsilane-modified halogen-free oligomers, polymers , or combinations thereof, provided that the oligomers and polymers do not fall within the definition of component c), c) 5-50% by weight of a non-alkoxyvinylsilane-modified compatibilizer selected from esters having a molecular weight of

> 800 g/mol, halogenated polyolefins, with the exception of polyvinyl chloride, modified acrylates and acetates or combinations thereof, where alkoxyvinylsilane modification means that -(CH2)2-Si-(OR)3- groups are present, where R is selected from H, -CH3, and -C2H5. - 33 -

3. Cable according to claim 2, characterized in that the layer comprises 15-70% by weight, preferably 35-65% by weight, of alkoxyvinylsilane-modified polyvinyl chloride.

4. Cable according to any one of claims 2 or 3, characterized in that the layer comprises 5-60% by weight, preferably 10-50% by weight, more preferably 25-50% by weight of component b).

A cable according to any one of claims 2 to 4, characterized in that the layer comprises 10-35% by weight, preferably 7-14% by weight, more preferably 5-10% by weight of the compatibiliser.

6. Cable according to any one of the preceding claims, characterized in that component b) is selected from homo- and copolymers of polyethylene, polypropylene, ethylene-propylene-diene rubber or silanes such as carbosilanes and polysiloxanes, and combinations of any two or several of them.

7. Cable according to any one of the preceding claims, characterized in that the compatibilizer is an adipic acid ester selected from poly(ethylene adipate), polybutylene adipate terephthalate (PBAT), poly(2-methyl-l,3-propylene adipate), poly(l ,4-butylene adipate), poly(1,4-butanediol/neopentyl glycol-altadipic acid), polyisononyl(1,4-butanediol-2,2-dimethyl-1,3-propanediol) adipate and combinations of any two or more of it is.

8. Cable according to any one of the preceding claims, characterized in that the layer further comprises fillers in an amount of 0.5-60% by weight, which fillers are preferably selected from carbonates, preferably calcium carbonate; silicates, preferably talc or kaolin; inorganic flame retardants, preferably aluminum hydroxide; and combinations thereof.

9. Cable according to any one of the preceding claims, characterized in that the layer further contains metal soaps present in an amount of up to 10% by weight, preferably 1-4% by weight, the metal soaps being preferably selected from dilaurates and distearates of zinc, barium, calcium, magnesium, or combinations of any two or more thereof.

10. Cable according to any one of the preceding claims, characterized in that the layer further comprises acid scavengers present in an amount of up to 18% by weight, preferably 1-8% by weight, the acid scavengers being preferably selected from aluminium /magnesium hydrotalcite, aluminium/magnesium/zinc hydrotalcite, calcium hydroxides, zeolite or combination of any two or more thereof.

11. Cable according to any one of the preceding claims, characterized in that the layer further contains phenolic antioxidants present in an amount of up to 4% by weight, preferably 0.25-2% by weight, the phenolic antioxidant being optionally selected are derived from ethylene bis(oxyethylene) bis(3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate), pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate), octadecyl [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2',3-bis[[3-[3,5-di-tert-butyl-4 - hydroxyphenyl]propionyl]]propionohydrazide and dialkyl esters of thiodipropionic acid.

12. Cable according to any one of the preceding claims, characterized in that the layer further comprises lubricants, wherein the lubricants are preferably selected from fatty acids with a chain length of C8-C18, montan waxes and their esters, chlorinated paraffins with a chain length of C10-C30 and Polyolefins grow, as well as combinations of any two or more thereof.

13. Cable according to any one of the preceding claims, characterized in that the layer is free of organotin compounds, preferably free of organometallic compounds.

14. Cable according to any one of the preceding claims, characterized in that the layer is free of monomeric plasticizers with a molecular weight of 700 g/mol or less, the layer being in particular free of esters of trimellitic, orthophthalic, terephthalic, pyromellitic -, Adipic, sebacic, phosphoric and citric acid and their anhydrides with alcohols with a chain length of C2-C15.

15. Cable according to any one of the preceding claims, characterized in that the layer has phase transitions determined by dynamic mechanical analysis in the range from -25 ° C to -15 ° C, and in the range from 25 ° C to 35 ° C, wherein the layer preferably has no further phase transitions in the range from -80°C to 100°C.

16. Cable according to any one of the preceding claims, characterized in that the layer has an elongation in the range of 20-30%, preferably 24-29%, determined by a hot-set test at 170° C. according to DIN EN 60811-507.

17. A cable according to any preceding claim, characterized in that the layer has any one or more of the following: a) a volume resistivity of >10 ⁹ ohm-mm according to ISO 6722-1:2011, b) a low-temperature Winding test according to ISO 6722-1:2011 at -40°C without cracks, breaks or other structural impairments, c) a thermal stability of > 140 minutes according to LV112-1 2014-04, d) a hot water resistance of >10 ⁹ ohm-mm after 1000h at 85°C according to ISO 6722-1:2011, e) short-term aging Oat 130°C for 240h according to ISO 6722-1:2011 without cracks, fractures or other structural impairments, f) a hot set test at 150°C for 15 minutes according to DIN EN 60811-2-1 of <100%.

18. A cable according to any preceding claim, wherein the layer is a primary insulation of an electrical conductor, and/or the jacket material for jacketing a plurality of cores.

19. A method of making a layer of a cable comprising a) mixing i) 5-85% by weight alkoxyvinylsilane modified polyvinyl chloride, ii) 5-70% by weight alkoxyvinylsilane modified halogen-free oligomers, halogen-free polymers or combination - 36 - thereof, provided that the oligomers and polymers do not fall under the definition of component iii), and iii) 5-50% by weight of a non-alkoxyvinylsilane-modified compatibilizer selected from esters with a molar mass > 800 g/ mol, halogenated polyolefins, with the exception of polyvinyl chloride, modified acrylates and acetates or combinations thereof, where alkoxyvinylsilane modification means that - (Cl-h)?- Si-(OR)s groups are present, where R is selected from H , -CH3, and -C2H5, b) extruding the mixture obtained in point a) as a layer of a cable, c) crosslinking the mixture obtained in point b) at a temperature of at least 20 ° C, preferably> 60 ° C and a relative Humidity of at least 50%, preferably >85%, at least one, preferably some or all of the polyvinyl chloride chains of component i) being crosslinked with at least one, preferably some or all of component ii) by siloxane bonds.

20. The method according to claim 19, characterized in that the crosslinking by water storage at a temperature of 70 ° C to 95 ° C, preferably 80 ° C to 90 ° C, for a period of 8 to 48 hours, preferably 12 to 36 hours , more preferably 18 to 30 hours, or for a period of 24 hours at 85 ° C.

21. Use of a composition in the manufacture of a cable or as a layer in a cable, wherein the composition is applied as a layer to cable strands or core ropes by sheath extrusion and is subsequently crosslinked by aging in moist heat to form siloxane bonds, the composition comprising: a) alkoxyvinylsilane-modified polyvinyl chloride in an amount of 5-85% by weight, b) alkoxyvinylsilane-modified halogen-free oligomers, halogen-free polymers or combination thereof in an amount of 5-70% by weight, provided that the oligomers and polymers do not fall under the definition of component c), and c) a compatibilizer selected from esters having a molecular weight of

> 800 g/mol, halogenated polyolefins, where polyvinyl chloride - 37 - except modified acrylates and acetates or combinations thereof, in an amount of 5-50% by weight, at least one, preferably part or all of the polyvinyl chloride chains of component a) having at least one, preferably part or all of component b) by siloxane bonds -(CH2)2-Si-

O-Si-(CH2)2- is crosslinked.