ELECTRICALLY CONDUCTIVE YARN

Description

[0001] The invention relates to an electrically conductive yarn with good physical and mechanical properties, a process for its production and its use.

[0002] It has long been known to produce electrically conductive yarns from thermoplastic polymers by incorporating an electrically conductive material into the thermoplastic polymer or by providing a thermoplastic polymer yarn with an electrically conductive sheath, for example, in the form of a bicomponent fiber. Examples of this can be found, among others, in EP-A-1559815 and EP-A-3502327, as well as in US Patent 3,586,597 and JP-A-2006 / 161190.

[0003] However, the combination of thermoplastic polymers and electrically conductive materials, e.g. graphite or carbon black, is not trivial, since in particular carbon or carbon-loaded polymer resin does not adhere well, which leads to chipping or flaking of the sheath.

[0004] Another problem is the mass of electrically conductive materials, especially carbon, required to generate a sufficient level of electrical conductivity. Historically, the carbon content required to provide adequate electrical conductivity is more than 25% by weight of the thermoplastic polymer. Such a high carbon content severely compromises the technical properties of yarns.

[0005] Recently, the availability of highly electrically conductive materials such as carbon nanotubes (CNTs), graphene, and fullerenes has led to a reduction in the required mass of electrically conductive materials and thus at least partially overcome the aforementioned disadvantages, as described in EP-A-1559815.

[0006] Nevertheless, the known electrically conductive yarns and their production processes suffer from significant shortcomings. On the one hand, there is the problem of embedding sufficient electrically conductive additive in the thread matrix to exceed the electrical percolation threshold while simultaneously maintaining the stability of the yarn during production in the spinning process. On the other hand, the forces occurring during spinning distortion must be taken into account, as these lead to a disruption of the percolating additive network during the necessary post-treatment, such as drawing, which results in a loss of electrical conductivity.

[0007] The realization of electrically conductive yarns in a conventional spinning process, as well as a bi-component fiber spinning process, leads to yarns that are either no longer sufficiently electrically conductive or not mechanically stable enough to be wound up.

[0008] Thus, there continued to be a need for electrically conductive yarns that, on the one hand, exhibit good electrical conductivity and, on the other, exhibit good mechanical properties. In particular, these good properties should be retained during subsequent use, for example, when exposed to mechanical stress and thermal load.

[0009] The present invention relates to an electrically conductive yarn having a core-sheath structure comprising: (i) a core of at least one multifilament yarn, (ii) a sheath comprising a mixture of (iia) thermoplastic elastomer and (iib) at least one electrically conductive material, characterized in that (iii) the multifilament yarn present as the core (iiia) has a tenacity-related strength of 40 to 300 cN / tex, (iiib) has an elongation at break of a maximum of 25%, (iiic) has a thermal shrinkage of a maximum of 6%, (iiid) has a linear density of 100 to 1200 dtex for a multifilament yarn made of organic polymers or a diameter in the range of 200 to 600 µm for a multifilament yarn made of non-organic materials, (iv) the sheath (iva) is in contact with the core and completely encloses it, (ivb) has a thickness of at least 10 µm, (ivc) has an electrical conductivity of at least 150 S / m, (ivd) the electrically conductive material has an electrical conductivity of at least 3×10 2< S / m, (ive) 1 to 45 wt.-% electrically conductive material, (ivf) 99 to 55 wt.% thermoplastic elastomer, (ivg) the sheath material has a thermal shrinkage of maximum 6%. . Core component

[0010] The multifilament yarn present in the yarn according to the invention has a tenacity of 40 to 300 cN / tex. Tenacity of 50 to 280 cN / tex, in particular 60 to 260 cN / tex, is particularly preferred.

[0011] The multifilament yarn present in the yarn according to the invention has an elongation at break of a maximum of 25%, preferably a maximum of 20%.

[0012] The multifilament yarn present in the yarn according to the invention has a thermal shrinkage of a maximum of 6%, preferably a maximum of 3%.

[0013] The multifilament yarn according to the invention has a linear density in the range of 100 to 1200 dtex, particularly preferably 250 to 500 dtex. The dtex specification refers to fibers made of organic polymers, in particular thermoplastic polymers, particularly preferably polyester.

[0014] The multifilament yarn according to the invention preferably has 10 to 500 individual filaments.

[0015] The multifilament yarn according to the invention is electrically non-conductive. The term "electrically non-conductive" means that the yarn has an electrical conductivity of < 10 -8 < S / m.

[0016] The multifilament yarn according to the invention is preferably a multifilament yarn made of aramids, preferably so-called high-modulus aramids, polyesters, preferably so-called high-strength polyester multifilaments, polyamides, preferably so-called high-strength polyamide multifilaments, glass, mineral fibers (basalt), and based on so-called hybrid multifilament yarns that comprise two or more of the aforementioned materials. The term "high-strength" refers to a tenacity-related strength of at least 50 cN / tex, in particular of at least 60 cN / tex, particularly preferably of at least 70 cN / tex. The multifilament yarn present in the yarn according to the invention preferably has a Young's modulus of at least 0.3 GPa, particularly preferably at least 0.5 GPa, in particular at least 0.8 GPa, particularly preferably at least 2 GPa or at least 2.5 GPa.

[0017] The multifilament yarn according to the invention is particularly preferably a multifilament yarn made of a thermoplastic polymer

[0018] In the present invention, the term "thermoplastic polymer" refers to a plastic that can be thermoformed within a specific temperature range, preferably in the range of 25°C to 350°C. This process is reversible, meaning it can be repeated as often as desired by cooling and reheating to the molten state, as long as the material has not been damaged excessively by overheating (so-called thermal decomposition) or by mechanical stress during molding. This is what distinguishes thermoplastic polymers from thermosets and elastomers.

[0019] The thermoplastic polymers used according to the invention are polymers from the group acrylonitrile-ethylene-propylene (diene) styrene copolymer, acrylonitrile-methacrylate copolymer, acrylonitrile-methyl methacrylate copolymer, chlorinated acrylonitrile, polyethylene-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-ethylene-propylene-styrene copolymer, cellulose acetobutyrate, cellulose acetopropionate, hydrated cellulose, carboxymethyl cellulose, cellulose nitrate, cellulose propionate, cellulose triacetate, polyvinyl chloride, ethylene-acrylic acid copolymer, ethylene-butyl acrylate copolymer, ethylene chlorotrifluoroethylene copolymer, ethylene-ethylene-acrylate copolymer, ethylene-ethylene methacrylate copolymer, ethylene-methacrylic acid copolymer, Ethylene-tetrafluoroethylene copolymer, ethylene-vinyl alcohol copolymer, ethylene-butene copolymer, ethylcellulose, polystyrene, polyfluoroethylene-propylene, methyl methacrylate-acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer,Methylcellulose, Polyamid 11, Polyamid 12, Polyamid 46, Polyamid 6, Polyamid 6-3-T, Polyamid 6-Terephthalsäurecopolymer, Polyamid 66, Polyamid 69, Polyamid 610, Polyamid 612, Polyamid 6I, Polyamid MXD 6, Polyamid PDA-T, Polyamid, Polyarylether, Polyaryletherketon, Polyamidimid, Polyarylamid, Polyamino-bismaleimid, Polyarylat, Polybuten-1, Polybutylacrylat, Polybenzimidazol, Poly-bismaleimid, Polyoxadiazobenzimidazol, Polybutylterephthalat, Polycarbonat, Polychlorotrifluorethylen, Polyethylen, Polyestercarbonat, Polyaryletherketon, Polyetheretherketon, Polyetherimid, Polyetherketon, Polyethylenoxid, Polyarylethersulfon, Polyethylenterephthalat, Polyimid, Polyisobutylen, Polyisocyanurat, Polyimidsulfon, Polymethacrylimid, Polymethacrylat, Poly-4-methlypenten, Polyacetal, Polypropylen, Polyphenyloxid, Polypropylenoxid, Polyphenylensulfid, Polyphenylensulfon, Polystyrol, Polysulfon, Polytetrafluorethylen, Polyurethan, Polyvinylacetat, Polyvinylalkohol, Polyvinylbutyral, Polyvinylchlorid,Polyvinylidene chloride, polyvinylidene fluoride, polyvinyl fluoride, polyvinyl methyl ether, polyvinyl pyrrolidone, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic anhydride copolymer, styrene-maleic anhydride-butadiene copolymer, styrene-methymethacrylate copolymer, styrene-methlystyrene copolymer, Styrene-acrylonitrile copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-methacrylate copolymer, vinyl chloride-maleic anhydride copolymer, vinyl chloride-maleimide copolymer, vinyl chloride-methyl methacrylate copolymer, vinyl chloride-octlyacrylate copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-vinylidene chloride-acrylonitrile copolymer.,

[0020] Among thermoplastic polymers, melt-spinnable synthetic polycondensates are preferred. Other suitable thermoplastic polymers are melt-spinnable synthetic biopolymers.

[0021] The term "synthetic biopolymer"In the present invention, "bioplastic" refers to a material that consists at least predominantly of biogenic raw materials (renewable raw materials). This distinguishes it from conventional, petroleum-based materials or plastics, such as polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC).

[0022] Among thermoplastic polymers, melt-spinnable synthetic polycondensates are preferred. These include aliphatic polyesters, arylaliphatic polyesters, aromatic polyesters, and their co- / terpolymers, which are produced from polyols and aliphatic and / or aromatic dicarboxylic acids or their derivatives (anhydrides, esters) by polycondensation. The polyols can be substituted or unsubstituted, and the polyols can be linear or branched.

[0023] Preferred polyols are polyols with 2 to 8 carbon atoms, polyalkylene ether glycols with 2 to 8 carbon atoms and cycloaliphatic diols with 4 to 12 carbon atoms. Examples of polyols that may be used include, but are not limited to, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, polyethylene glycol, diethylene glycol, 2,2,4-trimethyl-1,6-hexanediol, thiodiethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, triethylene glycol, and tetraethylene glycol. Preferred polyols include 1,4-butanediol, 1,3-propanediol, ethylene glycol, 1,6-hexanediol, diethylene glycol, isosorbitol and 1,4-cyclohexanedimethanol.

[0024] Preferred aliphatic dicarboxylic acids include substituted or unsubstituted, linear or branched, non-aromatic dicarboxylic acids selected from the group of aliphatic dicarboxylic acids having 2 to 12 carbon atoms and cycloaliphatic dicarboxylic acids having 5 to 10 carbon atoms, wherein the cycloaliphatic dicarboxylic acids may also have heteroatoms in the ring. The substituted non-aromatic dicarboxylic acids typically contain 1 to 4 substituents selected from halogen, C6-C10 aryl, and C1-C4 alkoxy. Non-limiting examples of aliphatic and cycloaliphatic dicarboxylic acids include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, fumaric acid, 2,2-dimethylglutaric acid, suberic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 3-cyclohexanedicarboxylic acid, diglycolic acid, itaconic acid, maleic acid, and 2,5-norbornanedicarboxylic acid.

[0025] Preferred aromatic dicarboxylic acids include substituted or unsubstituted aromatic dicarboxylic acids selected from the group of aromatic dicarboxylic acids having 6 to 12 carbon atoms, wherein these dicarboxylic acids may also have heteroatoms in the aromatic ring and / or in the substituent. The substituted aromatic dicarboxylic acids may typically have 1 to 4 substituents selected from halogen, C6-C10 aryl, and C1-C4 alkoxy. Non-limiting examples of aromatic dicarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, and furandicarboxylic acid.

[0026] The multifilament yarn according to the invention has a diameter in the range of 200µm to 600µm, whereby this information refers to a multifilament yarn made of non-organic fibers, in particular carbon, glass, mineral fibers (basalt).

[0027] Most preferably, the multifilament yarn according to the invention is a multifilament yarn made of a polyester, preferably a polyester based on aromatic dicarboxylic acids, which preferably: (i) have a fineness-related strength of 40 to 300 cN / tex, in particular of 60 to 100 cN / tex, and (ii) have a linear density in the range of 100 to 1200 dtex, particularly preferably 250 to 500 dtex, and (iii) have an elongation at break of a maximum of 25%, preferably a maximum of 20%, and (iv) have a thermal shrinkage of a maximum of 6%, preferably a maximum of 3%.

[0028] Particularly preferred are polyethylene terephthate (PET), polybutylene terephthate (PBT), polytrimethylene terephthalate (PTT) and polyethylene naphthalate (PEN).

[0029] Particularly preferred polyesters are PET and PEN with a glass transition temperature of at least 70°C.

[0030] Particularly preferred polyesters are PET which contain at least 95 mol% polyethylene terephthalate (PET).

[0031] Particularly preferred polyesters, in particular polyethylene terephthalate, have a molecular weight corresponding to a specific viscosity (η spec ) of at least 0.8 dl / g, in particular of at least 0.9 dl / g, each measured on solutions containing 1 g / l polymer in dichloroacetic acid at 25°C.

[0032] The production of such polyester multifilament yarns is known in principle, for example, from EP-A-0173221 and the references cited therein. Such high-strength polyester multifilament yarns are also known as tire cord and are used in technical products requiring high strength.

[0033] Industrial-scale production involves a melt spinning process. The thermoplastic polymer material is melted and extruded in liquid form into a spinning beam by means of an extruder. From this spinning beam, the molten material is fed to so-called spinnerets. The spinneret typically has a spinneret plate with multiple holes, from which the individual capillaries (filaments) of the fiber are extruded. In addition to melt spinning, wet or solvent spinning processes are also used to produce staple fibers. Instead of melting, a highly viscous solution of a synthetic polymer is extruded through nozzles with fine holes. Both processes are referred to by those skilled in the art as multi-position spinning processes.

[0034] The polymer fibers produced in this way are subjected to fiber post-processing to achieve the desired mechanical strength. This can involve modifying or finishing the polymer fibers for the respective end application or for the necessary intermediate treatment steps, e.g., drawing and / or crimping, typically by applying suitable finishes or sizes to the surface of the finished polymer fiber or the polymer fiber to be treated.

[0035] Additives, such as antistatic agents or colored pigments, may be added to the thermoplastic polymer, usually by incorporation into the molten thermoplastic polymer during the multi-station spinning process of the polymer fiber. Spinning oil equipment

[0036] In a further embodiment of the present invention, the thermoplastic multifilament yarn, in particular the polyester multifilament yarn, is treated with a commercially available spinning oil that decouples the multifilament yarn core from the thermoplastic sheath. The spinning oil is applied to the multifilament yarn before the sheathing process. The spinning oil used is a commercially available spinning oil. Examples of corresponding commercially available spinning oils are distillates (petroleum) consisting of dewaxed heavy paraffin-containing solvents (50-70%), mineral oils (25-50%), ethoxylated fatty alcohol (2.5-30%), C8-18 even-numbered amides (2.5-10%) and C18-unsaturated, N, Nbis(hydroxyethyl) C9-C11 alcohol ethoxylate (< 2.5%). Alternatively, ethylene glycol (2.5-10%), diisooctyl sodium sulfosuccinate (1-2.5%) and / or sodium alkanesulfonate (1-<2.5%) may be included. Sheath component

[0037] The sheath present in the yarn according to the invention is in contact with the multifilament yarn. This means that at least 90% of the surface of the multifilament yarn is in direct contact with the sheath, or at least 90% of the surface of the multifilament yarn is in indirect contact with the sheath, provided the previously described treatment with the spinning oil has been carried out.

[0038] The sheath has a thickness of at least 10 µm, preferably at least 20 µm, particularly preferably at least 50 µm. There is no upper limit to the thickness. Typically, the maximum thickness is 300 µm, so the thickness is in the range of 10 µm to 300 µm, preferably 50 µm to 300 µm, and in particular in the range of 100 µm to 150 µm.

[0039] The sheath has an electrical conductivity of at least 150 S / m.

[0040] The electrically conductive material used in the sheath has an electrical conductivity of at least 3×10 2< S / m, preferably at least 1×10 6< S / m.

[0041] The sheath comprises 55 to 99 wt.% thermoplastic elastomer and 1 to 45 wt.% electrically conductive material, preferably 85 to 99 wt.% thermoplastic elastomer and 1 to 15 wt.% electrically conductive material, particularly preferably 90 to 99 wt.% thermoplastic elastomer and 1 to 10 wt.% electrically conductive material, in particular 94 to 99 wt.% thermoplastic elastomer and 1 to 6 wt.% electrically conductive material. In addition, the sheath may also contain conventional additives, in particular those that facilitate the processability of the sheathing compound. The compound described above is referred to below as the sheath component.

[0042] The term thermoplastic elastomer refers to a thermoplastic elastomer according to DIN EN ISO 18064:2021-04 (replaces DIN EN ISO 18064:2015-03)

[0043] The thermoplastic elastomer used in the invention can be thermoformed (thermoplastically) within a specific temperature range, preferably in the range of 25°C to 350°C. This process is reversible, meaning it can be repeated as often as desired by cooling and reheating to the molten state, provided that the material has not been excessively damaged by overheating (so-called thermal decomposition) or by mechanical stress during the forming process.

[0044] A thermoplastic elastomer is usually obtained by combining thermoplastic with an elastomer, this can usually be done in two different ways, block polymers or polymer blends. Examples of suitable block polymers as a thermoplastic elastomer are TPS, TPU, TPA and TPC.

[0045] TPS stands for styrene block copolymers, particularly styrene / butadiene / styrene (SBS), or styrene / ethylene-butylene / styrene (SEBS), or styrene / ethylene-propylene / styrene (SEPS), or styrene / isoprene / styrene (SIS)-based styrene block copolymers. These block copolymers have hard and soft segments, with the styrene group forming the hard segment and the aliphatic groups, particularly aliphatic groups with 2 to 6 carbon atoms, forming the soft segment. Such TPS are characterized by a hardness of 10 Shore A to 70 Shore D. Preferred within the TPS are styrene / butadiene / styrene (SBS), styrene / ethylene-butylene / styrene (SEBS), styrene / ethylene-propylene / styrene (SEPS) or styrene / isoprene / styrene (SIS) with a hardness of 75 Shore A to 40 Shore D.

[0046] Particularly preferred within the TPS are styrene / butadiene / styrene (SBS), styrene / ethylene-butylene / styrene (SEBS), styrene / ethylene-propylene / styrene (SEPS) or styrene / isoprene / styrene (SIS), which in the form of the shell component have a melt flow rate of maximum 10g / 10 min (190°C, 21.60 kg).

[0047] Particularly preferred within the TPS are styrene / butadiene / styrene (SBS), styrene / ethylene-butylene / styrene (SEBS), styrene / ethylene-propylene / styrene (SEPS) or styrene / isoprene / styrene (SIS), which have a thermal shrinkage of a maximum of 3%, preferably a maximum of 2%, particularly preferably a maximum of 1%.

[0048] Particularly preferred are styrene / butadiene / styrene (SBS), styrene / ethylene-butylene / styrene (SEBS), styrene / ethylene-propylene / styrene (SEPS), or styrene / isoprene / styrene (SIS), which exhibit a combination of the aforementioned properties of thermal shrinkage, melt flow rate, tensile stress at break, and hardness, with styrene / ethylene-butylene / styrene (SEBS) being particularly preferred. Commercially available TPSs include Elastron®< G and Elastron®< D, Kraton®< (Kraton Polymers), Septon®< (Kuraray), Styroflex®< (BASF), Thermolast®< (Kraiburg TPE), ALLRUNA®< (ALLOD Werkstoff GmbH & Co.KG), or Saxomer®< TPE-S (PCW), as well as Pre-Elect®< TPE (premix). The aforementioned TPS elastomers exhibit particularly good conductivity and are also advantageous in processing. Thus, yarns according to the invention with this sheath component exhibit a particularly smooth surface.

[0049] TPU stands for thermoplastic polyurethane, i.e., a thermoplastic elastomer based on polyurethane. Such TPUs are characterized by a hardness of approximately 60 Shore A or higher. Commercially available TPUs include Elastollan ® (BASF), Desmopan ® , Texin ® , and Utechllan ® (Covestro).

[0050] TPA stands for thermoplastic polyether polyamide, a polyamide-based block polymer. Such TPAs ​​are characterized by a hardness of 60 Shore A to 70 Shore D. Commercially available TPAs ​​include PEBAX ® (Arkema) and VESTAMID ® E (Evonik Industries).

[0051] TPC stands for thermoplastic polyester elastomer, i.e. a block copolymer on a copolyester basis. Such TPCs are characterized by a hardness of 80 Shore A to 70 Shore D. Commercially available TPCs include Hytrel® (Du Pont), Keyflex® (LG Chem), and Skypel® (SK Chemicals). Examples of suitable polymer blends as thermoplastic elastomers are TPO and TPV. TPO stands for thermoplastic polyolefins, a mixture of a polyolefin-based plastic (usually PP or PE) and an elastomer such as EPDM. Unlike TPV, TPO is not or only partially cross-linked. TPOs are polymer blends that can be made hard or soft depending on their composition. Such TPOs are characterized by a hardness of 55 Shore A to 70 Shore D. Commercially available TPOs include Elastron® TPO and Saxomer® TPE-O (PCW).

[0052] TPV stands for thermoplastic polyolefin vulcanizate, a blend of a polyolefin-based plastic (primarily PP) and an elastomer such as EPDM. Unlike TPO, the elastomer in TPV is cross-linked or vulcanized. TPVs are characterized by a hardness of 35 Shore A to 50 Shore D. Commercially available TPVs include Elastron® V, Sarlink® (DSM), and Santoprene® (Exxon).

[0053] In a preferred embodiment, the thermoplastic elastomer is characterized by a Vicat softening temperature VST (50°C / 10N) of at least 50°C, preferably at least 60°C, in particular at least 100°C.

[0054] In a preferred embodiment, the thermoplastic elastomer is characterized by a melting temperature in the range 140 to 190°C, in particular in the range 150 to 175°C.

[0055] In a preferred embodiment, the thermoplastic elastomer is characterized by a thermal shrinkage of a maximum of 3%, preferably a maximum of 2%, particularly preferably a maximum of 1%.

[0056] In a preferred embodiment, the thermoplastic elastomer in the form of the sheath component has a melt flow rate of a maximum of 13 g / 10 min (190°C), in particular a maximum of 11 g / 10 min (190°C), particularly preferably a maximum of 10 g / 10 min (190°C).

[0057] In a preferred embodiment, the thermoplastic elastomer in the form of the sheath component has a melt flow rate of at most 50 g / 10 min (230°C), in particular of at most 30 g / 10 min (230°C), particularly preferably of at most 20 g / 10 min (230°C).

[0058] In a particularly preferred embodiment, the thermoplastic elastomer is a TPS and stands for styrene block copolymers, in particular styrene / butadiene / styrene (SBS), or styrene / ethylene-butylene / styrene (SEBS) or styrene / ethylene-propylene / styrene (SEPS) or styrene / isoprene / styrene (SIS) based styrene block copolymers, which in the form of the shell component have a melt flow rate of at most 30 g / 10 min (230°C), in particular of at most 20 g / 10 min (230°C), particularly preferably of at most 13 g / 10 min (230°C).

[0059] In a preferred embodiment, the thermoplastic elastomer has a hardness of 75 Shore A to 40 Shore D.

[0060] In a preferred embodiment, the thermoplastic elastomer has a water absorption (23°C) of a maximum of 0.8%.

[0061] In a preferred embodiment, the thermoplastic elastomer has a tensile stress at break of min. 10MPa and max. 28MPa.

[0062] In a preferred embodiment, a TPS styrene block copolymer selected from the group styrene / butadiene / styrene (SBS), styrene / ethylene-butylene / styrene (SEBS), styrene / ethylene-propylene / styrene (SEPS) or styrene / isoprene / styrene (SIS) is used as the thermoplastic elastomer, with the thermoplastic elastomer styrene / ethylene-butylene / styrene (SEBS) being particularly preferred, or a TPC thermoplastic polyester elastomer, ie a block copolymer on a copolyester basis, is used as the thermoplastic elastomer.

[0063] The electrically conductive material present in the sheath has an electrical conductivity of at least 3×10 2< S / m, preferably at least 1×10 6< S / m.

[0064] The electrically conductive material is preferably a particulate material, for example a powder or granules. In addition to spherical particles, non-spherical particles up to rod-shaped, fibrous, platelet-shaped or branched particles are also possible. The introduction of the electrically conductive material into the casing makes it possible to add larger particles, which usually interfere with the extrusion process during the production of spun threads. Within the scope of the present invention, the electrically conductive material can also have particles larger than 2 µm, preferably larger than 3 µm, in particular particles with a spherical size of more than 2 µm, preferably larger than 3 µm. Such particle sizes cannot be used in conventional thread spinning processes, since a filter is usually inserted upstream of the spinning beam.The presence of such large particles of electrically conductive material, on the other hand, makes it easier to overcome the electrical percolation threshold. Thus, with the aid of the present invention, even large particles of electrically conductive material can be incorporated into the yarn according to the invention.

[0065] The electrically conductive material is typically mixed with the thermoplastic polymer for the jacket. This can be done in the melt, for example, in an extruder, or by other metered addition. Masterbatches are also advantageous for better distribution of the electrically conductive material in the thermoplastic elastomer of the jacket.

[0066] Preferred electrically conductive materials for the thermoplastic sheath are disclosed, for example, in US-A-6,228,492; US-A-6,528,572; US-A-2003 / 158,323; US-A-6,621,970; CN-A-1431342; US-A-2003 / 236,588 and US-A-5,840,425.

[0067] Further preferred electrically conductive materials for the thermoplastic sheath are suitable carbon nanotubes as disclosed, for example, in US-A-6,099,960; US-A-6,280,697; US-A-2002 / 172,639; US-A-2003 / 102,222; US-A-2002 / 113,335 and US-A-2003 / 102,444.

[0068] Particularly preferred electrically conductive materials for the thermoplastic sheath are so-called CNTs (Carbon Nano Tubes) with an average diameter in the range of 8 to 12 nm, preferably in the range of 9 to 10 nm, determined by transmission electron microscopy (TEM),

[0069] Particularly preferred electrically conductive materials for the thermoplastic sheath are so-called CNTs (Carbon Nano Tubes) with an average diameter in the range of 8 to 12 nm, preferably in the range of 9 to 10 nm, and an average length in the range of 1 to 3 µm, preferably in the range of 1 to 2 µm, determined by means of transmission electron microscopy (TEM).

[0070] Particularly preferred electrically conductive materials for the thermoplastic sheath are so-called graphenes, in particular graphene with a height of <10nm and a lateral extent of 1.5µm, determined by means of transmission electron microscopy (TEM). Among the graphenes mentioned above, those are preferred which have a BET specific surface area of ​​more than 600m 2< / g.

[0071] The sheath is applied to the multifilament yarn by melt extrusion. The multifilament yarn is drawn through a ring-shaped extrusion die, around which another, larger extrusion die is installed, which applies the molten sheath component to the multifilament yarn. The yarn thickness is determined by the thickness of the core yarn, the diameter difference between the extrusion dies, and the yarn take-off speed. The multi-component yarn is then cooled in a water bath and wound up.

[0072] As already explained, the introduced (electrically conductive) materials can, in contrast to conventional spinning processes, have sizes of >3µm in one or more dimensions without permanently disrupting the manufacturing process.

[0073] The electrically conductive material used according to the invention can also form aggregates in the sheath. These aggregates from the particulate material, for example a powder or granules, can be determined using optical methods. For this purpose, a film is formed from the sheath component, and the aggregate size is determined using optical methods. The determination can be carried out, for example, using an FSA100 analyzer from OCS Optical Control Systems GmbH, Witten, Germany. For this purpose, a small amount of the sheath component (usually 1 wt.% sheath in RT5030 from OCS) is formed into a film (d=20 mm, >10 µm) and examined (area 1 m²<, gray value 150, filter size 100, resolution 10 µm, film thickness 30 µm). The individual defect size can, in individual cases, be up to 500 µm, and typically 90% of the defects are smaller than 100 µm. Preferably, the average numerical defect size is typically up to 50µm. Additives in the thermoplastics of the multifilament core and sheath

[0074] The thermoplastic polymers described above contain common additives. These are typically antioxidants, pigments, stabilizers, surfactants, waxes, flow promoters, solid solvents, plasticizers, and other materials, such as nucleating agents, that are added to improve the processability of the thermoplastic composition.

[0075] The additives mentioned above are not the electrically conductive material used in the invention. yarn

[0076] The electrically conductive yarn according to the invention with a core-sheath structure consisting of a multifilament yarn core and an electrically conductive sheath has, on the one hand, good mechanical properties and, on the other hand, good electrical conductivity.

[0077] The yarn according to the invention preferably has a diameter in the range of 0.1 mm to 2.5 mm.

[0078] The yarn according to the invention preferably has 10 to 500 individual filaments in the multifilament yarn core.

[0079] The yarn according to the invention is electrically non-conductive in the multifilament yarn core.

[0080] The yarn according to the invention preferably has an elongation at break (= elongation at break) of a maximum of 20%, particularly preferably a maximum of 15%.

[0081] The yarn according to the invention preferably has a maximum tensile strength in the range of 1500 to 3600 cN, in particular 1700 to 3600 cN, particularly preferably 2000 to 3600 cN.

[0082] The yarn according to the invention preferably has a tenacity in the range of 35 to 100 cN / tex, in particular 50 to 100 cN / tex. The tenacity of the yarn according to the invention is thus lower than the tenacity of the core, since the sheath material is included in determining the tenacity but does not make a significant contribution to the tenacity.

[0083] The yarn according to the invention preferably has a maximum bending force in the range from 0.5 to 20 cN, in particular from 1 to 20 cN, particularly preferably from 2 to 20 cN, particularly preferably from 5 to 20 cN.

[0084] The yarn according to the invention preferably has a flexural modulus in the range from 5 to 200 daN / mm 2< , in particular from 10 to 200 daN / mm 2< , particularly preferably 50 to 200 daN / mm 2< , particularly preferably 100 to 200 daN / mm 2< , particularly preferably in the range from 120 to 180 daN / mm 2< .

[0085] The yarn according to the invention preferably has a thermal shrinkage of maximum 5%.

[0086] The yarn according to the invention is electrically non-conductive in the multifilament yarn core.

[0087] The term electrically non-conductive means an electrical conductivity of < 10 -8< S / m.

[0088] The yarn according to the invention is electrically conductive in the sheath and has an electrical conductivity of at least 150 S / m.

[0089] The sheath of the yarn according to the invention has a thickness of at least 10 µm, preferably at least 20 µm, particularly preferably at least 50 µm. There is no upper limit for the thickness. Typically, the maximum thickness is 300 µm, so the thickness is in the range of 10 µm to 300 µm, preferably 50 µm to 300 µm, and in particular in the range of 100 µm to 150 µm.

[0090] The sheathing of the yarn according to the invention comprises 55 to 99 wt.% thermoplastic elastomer and 1 to 45 wt.% electrically conductive material, preferably 85 to 99 wt.% thermoplastic elastomer and 1 to 15 wt.% electrically conductive material, particularly preferably 90 to 99 wt.% thermoplastic elastomer and 1 to 10 wt.% electrically conductive material, in particular 94 to 99 wt.% thermoplastic elastomer and 1 to 6 wt.% electrically conductive material.

[0091] In addition, the sheathing may contain conventional additives, in particular those that facilitate the processability of the sheathing compound. Use of electrically conductive yarn

[0092] The present invention further relates to textile fabrics, in particular nonwovens, woven fabrics, knitted fabrics, meshes, cables containing the yarn according to the invention.

[0093] The yarns according to the invention can be used in sensor applications, for example, as pressure sensors in tires, and in biosensors in textiles. Furthermore, the yarns according to the invention can be used as antistatic materials, for example, in conveyor belts and sieves. Another application can be as cables in data transmission, or the yarn can be used in flexible electronic applications, for example, as smart clothing or as textile heating material. Production of the electrically conductive yarn

[0094] The present invention further relates to a process for producing the electrically conductive yarn according to the invention.

[0095] The process for producing the electrically conductive yarn according to the invention comprises the steps: a) feeding a multifilament yarn with (i) a fineness-related strength of 40 to 300 cN / tex and (ii) an elongation at break of a maximum of 25% and (iii) a thermal shrinkage of a maximum of 6% and (iv) a linear density of 100 to 1200 dtex for a multifilament yarn made of organic polymers or a diameter in the range of 200 to 600 µm for a multifilament yarn made of non-organic materials, into the opening of a round extrusion die, b) coating the multifilament yarn fed in according to step a) by means of a round extrusion die by extruding a mixture of (v) 55 to 99 wt.% thermoplastic elastomer and (vi) 45 to 1 wt.% electrically conductive material, (vii) electrically conductive material with an electrical conductivity of at least 3×10 2< S / m , (viii) the mixture forming the sheath has an electrical conductivity of min.150 S / m and (ix) the sheath material has a thermal shrinkage of maximum 6%, c) cooling the sheathed yarn, preferably to room temperature (25°C), whereby the yarn after cooling (x) has an electrically conductive sheath with a thickness of at least 10µm, d) winding the yarn onto a suitable carrier, preferably in the form of a spool.

[0096] The extrusion of the sheath, consisting essentially of thermoplastic elastomer and electrically conductive material, is usually carried out at temperatures in the range of 180 to 250°C, but at least 30°C above the melting temperature of the thermoplastic elastomer of the sheath.

[0097] The sheathing is extruded in such a way that the sheath material exhibits little or no orientation, i.e., it has predominantly amorphous structures and only a small amount of crystalline material. This lower orientation can be determined using DSC or wide-angle diffraction. Further methods can be found in the dissertation by S. Bogner (2002) at the Institute for Textile and Fiber Research, Stuttgart.

[0098] Furthermore, it is advantageous if the multifilament yarn to be coated is kept under tension. Depending on the viscosity of the molten coating, this tension is also built up – at least partially – by the braking effect of the molten component. A typical tensile stress, for example, is 5-15 cN. Furthermore, it is advantageous if the difference between the melting points of the core and sheath is at least 15°C, preferably at least 25°C, especially at least 30-80°C.

[0099] Typically, the material forming the sheath is first dried and then fed into the extruder, which has several heating zones and a cooling system in the feed. In addition to the heating zones inside the extruder, additional heating zones may also be located outside, toward the spinning head. After the nozzles containing the core yarn are installed in the spinning head, the molten sheath material is directed laterally through a nozzle combination onto the yarn (multifilament thread). This is followed by cooling, preferably in a water bath, and relaxation in a "chill unit," where the coated yarn typically runs over several godets without tension and is then wound up. If a thick sheath is used, the resulting weight of the coated yarn can lead to uneven running, which can be remedied by applying slight tension.In this case, a low voltage is usually applied across two godets, with the different speeds of the two godets being in the range of <0.5%.

[0100] The electrically conductive yarn according to the invention exhibits the inventive properties without further stretching, thus preventing damage caused by disruption of the percolating additive network. Furthermore, the special properties of the multifilament core, in particular the high specific strength, low elongation at break, and high Young's modulus, allow the application of mechanical stress that can be maintained during sheathing. The other special properties of the multifilament core, in particular the orientation and low thermal shrinkage, ensure that no thermal shrinkage is triggered during sheathing, thus avoiding forces that could damage the percolating additive network in the sheath. Furthermore, a very uniform sheath thickness is achieved. Test methods:

[0101] Unless already stated in the above description, the following measuring and testing methods are used: Linearity of the multifilament yarn:

[0102] The titre is determined according to DIN EN ISO1973 for fibers made of organic polymers. Diameter of the multifilament yarn

[0103] The diameter is determined using optical methods with a microscope. Suitable microscopes include SEM, digital microscope, and light microscope. Young's modulus

[0104] The determination of the Young's modulus is carried out together with the determination of the maximum tensile force or the maximum tensile force elongation. Elongation at break

[0105] The elongation at break is determined according to DIN EN ISO 2062:04 / 2010. Thermoshrink

[0106] The thermal shrinkage of the multifilament yarn (core) and the sheath is determined at 180°C according to the historical DIN 53866 T3 (03 / 1987). thickness

[0107] The thickness of the sheath material is determined using optical methods, i.e., examining the cross-section using a microscope. Suitable microscopes include SEM, digital microscope, and light microscope. Electrical conductivity

[0108] The electrical conductivity of the electrically conductive material is determined using a powder conductivity measuring system in which the powdered material is filled into a cylinder and compressed by a piston at a pressure of 30 MPa. The electrical resistance is continuously measured between two gold electrodes located on the top of the piston and the bottom of the cylinder. Resistance measurements are performed using a 4-point technique (resistance less than 1000 ohms) or a 2-point technique (resistance greater than 1000 ohms), with switching occurring programmatically based on the measured data. The instrument is controlled, as well as data acquisition and analysis, using customized software based on Agilent VEE Version 9.3.Further information can be found in Composites Science and Technology 2015, 114, 119-125 by Beate Krause, Regine Boldt, Liane Häußler, Petra Pötschke, "Ultralow percolation threshold in polyamide 6.6 / MWCNT composites".

[0109] The electrical conductivity of the electrically conductive sheath material is determined according to DIN 54345-5:07 / 1985. strength

[0110] The determination of the fineness-related strength is carried out according to DIN EN ISO 2062:04 / 2010. Glass transition temperature

[0111] Determination using Differential Scanning Calorimetry (DSC) using the following procedure: The DSC measurement is performed under nitrogen, calibrated against indium. The nitrogen flow is 50 ml / min; the sample weight for fibers is in the range of 2-3 mg. The temperature range is from -50 °C to 210 °C @ 10 K / min, then isothermally for 5 min, and finally back to -50 °C @ 10 K / min. The final temperature is generally always approximately 50 °C above the highest expected melting point. DSC measurement is performed using a TA / Waters Model Q100. Intrinsic viscosity (η spec ) (=specific viscosity)

[0112] The determination of the specific viscosity is measured on solutions containing 1 g / l polymer in dichloroacetic acid at 25°C. hardness

[0113] The determination of Shore A and Shore D hardness is carried out according to ISO 868 (DIN EN ISO 868:2003-10). Vicat softening temperature VST

[0114] The Vicat softening temperature (A50) is determined according to ISO 306 at 50°C / 10N (DIN EN ISO 306:2014-03). Melting point

[0115] The melting temperature is determined according to ISO 11357-1 / -3 at 10°C / min. (DIN EN ISO 11357-1:2017-02 and DIN EN ISO 11357-3:2018-07) Melt-Flow Rate

[0116] The melt mass flow rate is determined according to DIN EN ISO 1133 (2012) at 190°C and 230°C (21.6 kg). Water absorption

[0117] The water absorption is determined at 23°C according to DIN EN ISO 62 (2008). Tensile stress at break

[0118] The determination of the tensile stress at break is carried out according to DIN EN ISO 527-2 / 1A (2012). Maximum tensile force

[0119] The maximum tensile force is determined according to DIN EN ISO 2062:04 / 2010. Maximum bending force

[0120] To determine the maximum bending force, the yarn is placed on a suitable measuring head on two supports. The natural curvature points downward.

[0121] The bending pin moves downward, forcing the yarn through. At the end of the test section, the bending pin moves upward again. The force is recorded. The maximum bending force and, if applicable, the force at 10° deflection are evaluated. Flexural modulus The flexural modulus is determined according to the bending force. Examples:

[0122] The present invention is illustrated by the following example without being limited thereby. Example 1 Coating with the composition / properties

[0123] The compound used for the jacket is a SEBS TPS with 20-40 wt.% carbon black as an electrically conductive additive. The compound exhibits relatively large agglomerates of up to 90 µm in diameter, is black, and comes in granular form. Its melting point is 152.2 °C.

[0124] Other features include: Vol. Resistance and Surface resistance MFI (190°C, 2 1.6 kg) Tensile strength Elongation at break Shore A shore D 3.5 Ωcm 400Ω 9.8 g / 10 min 7.1 MPa 547 % 87 33

[0125] Before processing, the compound is dried at 60 °C for at least 4 hours and fed into the extruder without contact with air. Supplied yarn

[0126] The core yarn is a 280 dtex f 48 high-tenacity yarn with a breaking elongation of 17.6%, a maximum tensile strength of 18.3 N, and a maximum relative tensile strength of 683 mN / tex. The yarn is twisted Z60. Experimental procedure

[0127] To produce a 0.65 mm thick conductive yarn from a conductive SEBS / additive compound, a spinneret combination of 0.3 mm inner and 0.65 mm outer nozzles is used. The fed yarn is fed through the inner of the two spinnerets and the spinning head and then through the water bath and over the gallettes to the winding unit. The spinnerets are screwed tightly into the spinning head, and winding begins. The previously dried, electrically conductive compound is fed into the extruder, where it is heated to approximately 210 °C in three heating zones until the required viscosity is reached. The melt is fed onto the running yarn via the extruder; the start of the coating is clearly recognizable by the color change of the yarn from white to black. The extruder speed is adjusted depending on the winding speed so that the yarn reaches the maximum diameter of 0.65 mm and then does not increase any further.

[0128] Test data of the coated yarn Yarn count [dtex] 3605,1 Maximum tensile force [cN] 1804,8 Fineness-related maximum tensile strength [cN / tex] 64,5 Elongation [%] 16.1 Max. bending force [cN] 2.03 Flexural modulus [daN / mm^2] 8 Electrical conductivity [Ω / cm] 800

[0129] The figure shows the force / elongation diagram of the yarn described in Example 1, as well as microscopic images of the same yarn Figure 1 shows the force-elongation behavior of a yarn according to the invention according to Example 1. Figure 2 shows a microscopic image of a yarn according to the invention according to Example 1. Figure 3 shows a microscopic image of a yarn according to the invention according to Example 1. Figure 4 shows a microscopic image of the cross section of a yarn according to the invention according to Example 1.

Claims

1. Electrically conductive yarn with a core-coat structure: (i) a core of at least one multifilament yarn, (ii) a coat, comprising a mixture of (iia) thermoplastic elastomers and (iib) at least one electrically conductive material, characterised in that (iii) the multifilament yarn that is provided as the core (iiia) has a breaking strength according to DIN EN ISO 2062:04 / 2010 of 40 to 300 cN / tex, (iiib) has an elongation at break according to DIN EN ISO 2062:04 / 2010 of maximum 25 %, (iiic) has a maximum of 6% thermal shrinkage at 180°C according to the historical DIN 53866 T3 (03 / 1987) , (iiid) has a titre of 100 to 1200 dtex for a multifilament yarn of organic polymers or has a diameter in the range from 200 to 600 µm for a multifilament yarn made of non-organic materials, (iv) the coat (iva) contacts the core and completely encloses it, (ivb) has a thickness of at least 10 µm, (ivc) has an electrical conductivity of at least 150 S / m according to DIN 54345-5:07 / 1985, (ivd) the electrically conductive material has an electrical conductivity of at least 3×102 S / m as determined in the description, (ive) contains 1 to 45% by weight of electrically conductive material, (ivf) contains 99 to 55% by weight of thermoplastic elastomer, (ivg) the coat material has a maximum thermal shrinkage of 6% at 180°C according to the historical DIN 53866 T3 (03 / 1987).

2. Yarn according to claim 1, characterised in that the breaking strength of the multifilament yarn in the core is 50 to 280 cN / tex, preferably 60 to 260 cN / tex.

3. Yarn according to claim 1 or 2, characterised in that the multifilament yarn has a maximum elongation at break of 20% in the core.

4. Yarn according to claim 1, 2 or 3, characterised in that the multifilament yarn is electrically non-conductive in the core and has an electrical conductivity < 10-8 S / m.

5. Yarn according to one or more of claims 1 to 4, characterised in that the multifilament yarn in the core is a multifilament yarn of aramids, polyesters, polyamides, glass, mineral fibres, or mixtures of two or more of the aforementioned materials.

6. Yarn according to one or more of claims 1 to 4, characterised in that the multifilament yarn in the core comprises one or more thermoplastic polymers, preferably the thermoplastic polymers comprise melt-spinnable synthetic polycondensates, in particular aliphatic polyesters, aryl-aliphatic polyesters, aromatic polyesters, and their co- / ter-polymers.

7. Yarn according to one or more of claims 1 to 6, characterised in that the multifilament yarn in the core comprises a polyester, preferably a polyester based on aromatic dicarboxylic acids, and which has (i) a breaking strength of 40 to 300 cN / tex, in particular of 60 to 100cN / tex, (ii) a titre in the range from 100 to 1200 dtex, especially preferably 250 to 500 dtex, and (iii) an elongation at break of maximum 25%, preferably maximum 20%, and (iv) a thermal shrinkage of maximum 6%, preferably maximum 3%.

8. Yarn according to one or more of claims 1 to 7, characterised in that the coat directly contacts at least 90% of the surface of the multifilament yarn in the core.

9. Yarn according to one or more of claims 1 to 8, characterised in that the coat comprises 85 to 99% by weight thermoplastic elastomer and 1 to 15% by weight electrically conductive material, preferably 90 to 99% by weight of thermoplastic elastomer and 1 to 10% by weight electrically conductive material, in particular 94 to 99% by weight thermoplastic elastomer and 1 to 6% by weight electrically conductive material.

10. Yarn according to one or more of claims 1 to 9, characterised in that the coat comprises one or more thermoplastic elastomers selected from the group of thermoplastic polyolefins (TPO), thermoplastic polyolefin vulcanizates (TPV), styrene block copolymers (TPS), thermoplastic polyurethane (TPU), thermoplastic polyether polyamides (TPA), and / or thermoplastic polyester elastomers (TPC).

11. Yarn according to one or more of claims 1 to 10, characterised in that the coat comprises one or more thermoplastic elastomers, the Vicat softening temperature VST of which is at least 50°C, preferably at least 60°C, in particular at least 100°C at 50°C / 10N according to ISO 306 (DIN EN ISO 306:2014-03).

12. Yarn according to one or more of claims 1 to 11, characterised in that the coat comprises one or more thermoplastic elastomers, the melting temperature of which is in the range from 140 to 190°C, in particular in the range from 150 to 175°C at 10°C / min according to ISO 11357-1 / -3.

13. Yarn according to one or more of claims 1 to 12, characterised in that the thermoplastic elastomer in form of the coat component has a melt flow rate at 190°C (21.6 kg) according to DIN EN ISO 1133 (2012) of at most 13 g / 10 min, in particular at most 11 g / 10 min, particularly preferably at most 10 g / 10 min.

14. Yarn according to one or more of claims 1 to 13, characterised in that the thermoplastic elastomer in form of the coat component has a melt flow rate at 230°C (21.6 kg) according to DIN EN ISO 1133 (2012) of at most 50 g / 10 min, in particular at most 30 g / 10 min, particularly preferably at most 20 g / 10 min.

15. Yarn according to one or more of claims 1 to 14, characterised in that the coat comprises one or more electrically conductive materials selected from the group of carbon nanotubes (CNT) and / or graphene.

16. Yarn according to one or more of claims 1 to 15, characterised in that the coat comprises one or more electrically conductive materials, and these comprise particles with a particle size of more than 2µm.

17. Yarn according to one or more of claims 1 to 16, characterised in that the diameter is 0.1 mm to 2.5 mm.

18. Yarn according to one or more of claims 1 to 17, characterised in that the yarn has an elongation at break according to DIN EN ISO 2062:01 / 2010 of maximum 20%, more preferably maximum 15%.

19. Yarn according to one or more of claims 1 to 18, characterised in that the yarn has a maximum single-end breaking force according to DIN EN ISO 2062:04 / 2010 in the range from 1500 to 3600 cN, preferably 1700 to 3600 cN, in particular from 2000 to 3600 cN.

20. Yarn according to one or more of claims 1 to 19, characterised in that the yarn has a maximum bending force, which is determined as described on page 21 of the description, in the range from 0.5 to 20 cN, preferably 1 to 20 cN, in particular from 2 to 20 cN, most preferably from 5 to 20 cN.

21. Yarn according to one or more of claims 1 to 20, characterised in that the yarn has a bending modulus, which is determined as described on page 21 of the description, in the range from 5 to 200 daN / mm2, preferably from 10 to 200 daN / mm2, in particular 50 to 200 daN / mm2, most preferably from 100 to 200 daN / mm2, in particular in the range from 120 to 180 daN / mm2.

22. Yarn according to one or more of claims 1 to 21, characterised in that the yarn has a thermal shrinkage of maximum 5% at 180°C according to the historical DIN 53866 T3 (03 / 1987).

23. Yarn according to one or more of claims 1 to 22, characterised in that the coat has a thickness of at least 20 µm, preferably at least 50 µm24. A method of manufacturing the yarn defined in claims 1 to 23, comprising the steps of: a) feeding a multifilament yarn with (i) a breaking strength according to DIN EN ISO 2062:04 / 2010 of 40 to 300 cN / tex and (ii) an elongation at break according to DIN EM ISO 2062:04 / 2010 of maximum 25%, and (iii) a thermal shrinkage of maximum 6% at 180°C according to the historical DIN 53866 T3 (03 / 1987), and (iv) a titre of 100 to 1200 dtex for a multifilament yarn of organic polymers or a diameter in the range from 200 to 600 µm for a multifilament yarn of non-organic materials, into the opening of a round extrusion nozzle; b) coating of the multifilament yarn supplied in step a) by means of a round extrusion nozzle by extruding a mixture of (v) 55 to 99% by weight thermoplastic elastomer, and (vi) 45 to 1% by weight electrically conductive material, (vii) electrically conductive material with an electrical conductivity, which is determined as described in the description, of at least3x102 S / m, (viii) the mixture forming the coat has an electrical conductivity according to DIN 54345-5:07 / 1985 of at least 150 S / m, and (ix) the coat material has a thermal shrinkage of maximum 6% at 180°C according to the historical DIN 53866 T3 (03 / 1987), c) cooling of the coated yarn, preferably to room temperature (25°C), whereby the yarn, after cooling, (x) has an electrically conductive coating with a thickness of at least 10 µm, d) winding up the yarn onto a suitable carrier, preferably in the form of a bobbin.

25. Use of the yarn, as defined in claims 1 to 23, for the manufacture of (i) textile fabrics, in particular non-woven fabrics, woven fabrics, knitted fabrics, knitted and crocheted, meshes, (ii) cables, (iii) sensors, (iv) as antistatic material, in particular, for example, in conveyor and transport belts or strainers, (v) in data transmission or (vi) in flexible electronics applications.

26. A textile fabric comprising one or more yarns as defined in claims 1 to 23.