Enamel wire

Description

[0001] The invention relates to an enamelled wire with a conductor core, wherein the surface of the conductor core is completely or substantially completely coated with an electrical insulating varnish.

[0002] Enameled wires of the aforementioned type are known in principle from practice and from the prior art in various embodiments. Reference is made to US 6,087,592 A, US 4,537,804 A, WO 99 / 08288 A1, WO 2013 / 054738 A1, and EP 2 923 362 B1. Such enameled wires are used in electrical machines or components such as coils, rotors, and the like. To manufacture such machines or components, the enameled wire is typically wound, and a plurality of windings of the enameled wire are arranged, for example, in a slot. During this winding process, it is desirable to achieve a high packing density of the enameled wire, since the efficiency of the machines or components depends on the utilization of the available slot area or slot cross-sectional area.This utilization of the available slot area can be described by the slot fill factor, which indicates the ratio of the effective cross-sectional area of ​​the conductor core to the maximum cross-sectional area of ​​the slot. In addition to the goal of achieving the highest possible efficiency, a high packing density or optimal utilization of the available slot area is also advantageous with regard to the size of the machines or components, since a high packing density or high utilization of the slot area enables a more compact design.

[0003] With the enamelled wires known from practice, it has been shown that the available slot areas often cannot be used satisfactorily, resulting in low slot fill factors and thus low efficiencies. With the known enamelled wires, the insulation layer applied to the conductor core must have a certain minimum thickness in order to meet the requirements placed on the enamelled wire with regard to electrical properties, such as dielectric strength. At the same time, this minimum layer thickness limits the maximum achievable slot fill factor. To ensure the required electrical properties, the wire insulation must therefore have a certain thickness, and at the same time, the slot fill factor and thus the efficiency of the component or machine decrease with increasing insulation layer thickness.

[0004] In contrast, the invention is based on the technical problem of providing an enameled wire of the type mentioned above, which is characterized by an advantageously thin insulation layer compared to the enameled wires known in practice, with which the previously known slot fill factors can be improved while still meeting all requirements with regard to electrical properties. The invention is thus also based on the technical problem of providing an enameled wire that enables an optimal compromise between a thin layer thickness of the electrical insulation varnish and yet satisfactory electrical properties that meet the requirements, with which the slot area available during the winding process can be optimally utilized.

[0005] To solve the technical problem, the invention teaches a lacquered wire with a conductor core, wherein the surface of the conductor core is completely or substantially completely coated with an electrical insulating lacquer, wherein the electrical insulating lacquer is formed on the basis of at least one lacquer polymer, wherein the electrical insulating lacquer has a plurality of functional layers, wherein as functional layer(s) at least one conductive functional layer with at least one conductive additive is provided and at least one insulating functional layer with at least one insulating filler is provided and at least one neutral functional layer is provided which is free of conductive additives and free of insulating fillers and which consists of the at least one lacquer polymer or essentially of the at least one lacquer polymer, wherein a neutral functional layer is applied directly to the conductor core as a base layer, wherein at least one conductive functional layer and at least one insulating functional layer are applied to this base layer and wherein the ratio of the diameter of the conductor core to the total layer thickness of the electrical insulating varnish is greater than or equal to three.

[0006] It has proven effective for the conductor core to be made of copper or aluminum, or essentially of copper or aluminum. However, other electrically conductive materials, preferably metals, are also possible for the conductor core of the enameled wire. The conductor core is recommended to be a round wire, thus having a round cross-sectional area. According to an alternative embodiment, the conductor core is a flat wire with an oval cross-sectional area or a rectangular wire with a rectangular cross-sectional area. In principle, other cross-sectional shapes of the conductor core are also within the scope of the invention.

[0007] In the context of the invention, conductivity refers in particular to electrical conductivity. In this context, a conductive additive refers in particular to an electrically conductive or conducting additive, while an insulating filler refers in the context of the invention to a filler that is not or essentially not electrically conductive or conducting.

[0008] Preferably, the at least one conductive functional layer comprises at least the lacquer polymer and at least one conductive additive, and particularly preferably, the at least one lacquer polymer forms a matrix in which the at least one conductive additive is arranged. It is within the scope of the invention for the at least one insulating functional layer to comprise at least the lacquer polymer and at least one insulating filler, and particularly preferably, the at least one lacquer polymer forms a matrix in which the at least one insulating filler is arranged.

[0009] According to the invention, the electrical insulating varnish comprises at least one conductive functional layer and at least one insulating functional layer. In this embodiment, the at least one conductive additive and the at least one insulating filler are preferably arranged in separate functional layers of the electrical insulating varnish, namely in the at least one conductive functional layer on the one hand and in the at least one insulating functional layer on the other.

[0010] According to a highly recommended embodiment of the invention, the electrical insulating varnish has at least two conductive functional layers and / or at least two insulating functional layers. The functional layers are then expediently arranged in an alternating layer sequence, for example, in the sequence "conductive functional layer - insulating functional layer - conductive functional layer - insulating functional layer." Particularly preferably, the conductive or insulating functional layers arranged in an alternating layer sequence are arranged or applied directly on the base layer. It is further within the scope of the invention that at least two conductive functional layers and / or at least two insulating functional layers are provided, and that, in addition to the base layer according to the invention, at least one further neutral functional layer is provided, wherein the functional layers are recommended to be arranged in an alternating layer sequence.

[0011] A preferred embodiment of the invention is characterized in that a finishing layer of the electrical insulating varnish is provided, wherein the finishing layer is preferably the outer layer of the electrical insulating varnish, which has the greatest distance of the electrical insulating varnish layers from the conductor core. Expediently, the finishing layer is an insulating functional layer or a neutral functional layer. According to a particularly recommended embodiment, the finishing layer is a neutral functional layer. It is further within the scope of the invention that at least one outer layer, preferably an outer layer different from the electrical insulating varnish, is arranged on the electrical insulating varnish or on the finishing layer, wherein the outer layer is particularly preferably a sliding layer whose coefficient of friction is preferably smaller than the coefficient of friction of the electrical insulating varnish or the finishing layer of the electrical insulating varnish.

[0012] The electrical insulating varnish is recommended to have at least three, preferably at least four, functional layers. It is recommended that the electrical insulating varnish have at least five, preferably at least six, functional layers. According to a proven embodiment of the invention, the electrical insulating varnish has a maximum of 40, preferably a maximum of 35, and particularly preferably a maximum of 30 functional layers.

[0013] One embodiment variant, which is of particular importance within the scope of the invention, is characterized in that the layer thickness of a functional layer is between 0.5 µm and 15 µm, preferably between 1 µm and 10 µm, particularly preferably between 2 µm and 5 µm. Within the scope of the invention, layer thickness or thickness of the layer means in particular the extent of the layer transverse to the longitudinal direction of the enameled wire. It is within the scope of the invention for the individual functional layers to have the same layer thickness or essentially the same layer thickness. In principle, however, the individual functional layers can also have different layer thicknesses from one another.

[0014] According to a preferred embodiment, the base layer is formed as a layer aggregate consisting of at least two neutral functional layers. Preferably, the layer aggregate consists solely of neutral functional layers without the interposition of other functional layers, and the layer aggregate or the base layer is applied directly to the conductor core.

[0015] A particularly preferred embodiment of the invention is characterized in that the total layer thickness (d E ) of the electrical insulating varnish is between 2 µm and 200 µm, preferably between 3 µm and 150 µm, particularly preferably between 3.5 µm and 120 µm. It is recommended that the conductor core have a diameter (d K ) between 0.03 mm and 7 mm, preferably between 0.05 mm and 5 mm. In this context, the diameter (d K ) of the conductor core refers to the largest diameter of the cross-sectional area of ​​the conductor core, transverse to the longitudinal direction of the enameled wire.

[0016] According to the invention, the ratio of the diameter (d K ) of the conductor core to the total layer thickness (d E ) of the electrical insulating varnish is greater than or equal to three. Expediently, the ratio of the diameter of the conductor core to the total layer thickness of the electrical insulating varnish is greater than or equal to four, preferably greater than or equal to five, particularly preferably greater than or equal to ten. According to one embodiment, the ratio of the diameter of the conductor core to the total layer thickness of the electrical insulating varnish is greater than or equal to 20, preferably greater than or equal to 30, for example 40. It is recommended that the ratio of the diameter of the conductor core to the total layer thickness of the electrical insulating varnish is at least 3, preferably at least 5 and particularly preferably at least 10 if the diameter of the conductor core is between 0.05 mm and 1 mm.It is within the scope of the invention that the ratio of the diameter of the conductor core to the total layer thickness of the electrical insulating varnish is at least 10, preferably at least 20, particularly preferably at least 30, if the conductor core has a diameter of preferably more than 1 mm.

[0017] One embodiment of particular importance within the scope of the invention is characterized in that the conductive additive is selected from the group: "Inorganic semiconductor material, organic semiconductor material, conductive carbon material." In this context, semiconductor material refers in particular to a material whose electrical conductivity (σ) lies between that of electrical conductors and that of non-conductors.

[0018] The conductive additive is expediently a ceramic semiconductor material, preferably selected from the group consisting of carbides, silicides, nitrides, oxides, and titanates. The conductive additive is preferably a carbide or nitride. This embodiment is based on the finding that particularly advantageous properties of the enameled wire can be achieved using carbides or nitrides as conductive additives, and in particular, a low insulation layer thickness can be achieved while simultaneously achieving surprisingly high dielectric strength. It has proven useful in this context for the conductive additive to be a silicon carbide or transition metal nitride, preferably an early transition metal nitride. In this context, an early transition metal nitride refers to a transition metal nitride with a group 3, group 4, group 5, or group 6 transition metal, i.e., a transition metal from the scandium, titanium, vanadium, or chromium group.Most preferably, the conductive additive is selected from the group: "titanium nitrides, zirconium nitrides, hafnium nitrides, vanadium nitrides, niobium nitrides, tantalum nitrides, chromium nitrides, molybdenum nitrides, tungsten nitrides".

[0019] It is further within the scope of the invention that the conductive additive is selected from the group: "carbon blacks, carbon nanotubes, fullerenes, graphene, graphite, glassy carbons".

[0020] According to a particularly recommended embodiment of the invention, the conductive additive is a II-VI semiconductor, preferably a zinc sulfide or zinc oxide. II-VI semiconductor in this context means a compound semiconductor consisting of at least one element from the second main group (alkaline earth metals) and / or at least one Group 12 element and at least one element from the sixth main group (chalcogens).

[0021] It is within the scope of the invention for the electrical insulating varnish to contain a plurality of different conductive additives, for example, at least two conductive additives. In such an embodiment, the at least two mutually different conductive additives can each be arranged in different conductive functional layers and / or in the same conductive functional layers.

[0022] A highly proven embodiment of the invention is characterized by the insulating filler being an inorganic substance. It is recommended that the insulating filler be selected from the group: "mica, kaolin, corundum, fused alumina, silicates, aluminum oxides, sulfates, silicon dioxides, titanium dioxides."

[0023] According to a preferred embodiment, the insulating filler is a surface-modified silicate. The insulating filler is recommended to be a silanized silicate, particularly preferably a silicate modified with at least one component from the group consisting of aminosilane, epoxysilane, methacrylsilane, trimethylsilane, methylsilane, and vinylsilane.

[0024] It is further within the scope of the invention for the electrical insulating varnish to comprise a plurality of different insulating fillers, for example, at least two different insulating fillers. Within the scope of such an embodiment, the at least two mutually different insulating fillers can each be arranged in different insulating functional layers and / or in the same insulating functional layers.

[0025] According to a particularly preferred embodiment of the invention, the particles of the conductive additive and / or the insulating filler have a particle size in the range of 0.05 to 50 µm, preferably in the range of 0.05 to 20 µm, preferably in the range of 0.1 to 10 µm and particularly preferably in the range of 0.1 to 5 µm.

[0026] It has proven useful for the lacquer polymer to be based on at least one component from the group: "polyester, polyesterimide, polyesteramideimide, polyurethane, polyamide, polyamideimide, polyimide." Particularly preferably, the lacquer polymer is based on at least one component from the group: "polyester, polyesterimide, polyamideimide," and most preferably, the lacquer polymer is based on polyesterimide. It is within the scope of the invention that the neutral functional layer(s) applied to the conductive core or directly to the conductive core consists / consists of the lacquer polymer or of at least one lacquer polymer. A very preferred embodiment of the invention is characterized in that the final layer of the electrical insulating lacquer is designed as a neutral functional layer and consists or essentially consists of at least one of the aforementioned lacquer polymers.It has proven to be advantageous that the lacquer polymer of the neutral functional layer or the final layer is based on at least one component from the group: polyester, polyesterimide, polyamideimide. It has proven particularly advantageous that the lacquer polymer of the neutral functional layer or the final layer is based on polyamideimide.

[0027] A highly recommended embodiment, which is of particular importance within the scope of the invention, is characterized in that a conductive functional layer contains between 0.05 wt.% and 15 wt.%, preferably between 0.1 wt.% and 10 wt.%, particularly preferably between 0.2 wt.% and 5 wt.%, very particularly preferably between 0.3 wt.% and 3 wt.% of the conductive additive. It is within the scope of the invention for an insulating functional layer of the enamelled wire according to the invention to have the above-mentioned wt.% proportions of insulating filler. The proportion of the conductive additive or the insulating filler in the electrical insulating varnish refers in this context to the cured electrical insulating varnish. In the event that the electrical insulating varnish is applied to the conductor core as a solvent-based wet varnish, the proportion of the conductive additive orThe insulating filler in the electrical insulating varnish in this context therefore refers to the cured and solvent-free or essentially solvent-free state of the electrical insulating varnish. Within the scope of the invention, the curing of the electrical insulating varnish or the electrical insulating varnish layers is preferably carried out by heating. In principle, however, the curing of the electrical insulating varnish or the electrical insulating varnish layers can also be carried out by UV irradiation.

[0028] According to a recommended embodiment, the electrical insulating varnish or the electrical insulating varnish layers are applied to the conductor core as a solvent-based wet varnish in a varnish bath or immersion bath. The wet varnish can be formed from the at least one varnish polymer and, if appropriate, with at least one additive and / or filler preferably homogeneously dispersed in the varnish polymer, as well as at least one solvent. In principle, it is also possible for the at least one varnish polymer, if appropriate with at least one additive and / or filler, to be applied to the conductor core solvent-free.

[0029] It is within the scope of the invention that the electrical insulating varnish or the electrical insulating varnish layers are applied to the conductor core as a solvent-based wet varnish via a felt that applies the varnish or via a nozzle and then cured. It is also within the scope of the invention that the electrical insulating varnish is applied to the conductor core by an extrusion process or that the electrical insulating varnish layers are applied to the conductor core by a coextrusion process.

[0030] According to a particularly recommended embodiment of the invention, a conductive layer of the liquid, uncured electrical insulating varnish contains between 0.001 wt.% and 10 wt.%, preferably between 0.005 wt.% and 5 wt.%, more preferably between 0.01 wt.% and 3 wt.%, most preferably between 0.01 wt.% and 1 wt.% of the conductive additive. It is within the scope of the invention for an insulating layer of the liquid, uncured electrical insulating varnish to contain corresponding wt.% proportions of insulating filler. In this context, liquid, uncured insulating varnish means in particular the solvent-containing wet varnish in which the conductive additive or the insulating filler is preferably homogeneously dispersed.

[0031] A particularly preferred embodiment of the invention is characterized in that the conductive additive is distributed homogeneously or substantially homogeneously in the respective conductive functional layer. It is further within the scope of the invention for the insulating filler to be distributed homogeneously or substantially homogeneously in the respective insulating functional layer.

[0032] A highly recommended embodiment of the invention is characterized in that the at least one conductive additive has an electrical conductivity (σ) at room temperature between 10 -10< S cm -1< to 10 6< S cm -1< , preferably between 10 -8< S cm -1< and 10 4< S cm -1<. The specific resistance (ρ) of the at least one conductive additive expediently has a negative temperature coefficient. Negative temperature coefficient of the specific resistance of the at least one conductive additive means, in the context of the invention, in particular that the specific resistance (ρ) of the at least one conductive additive preferably decreases with an increase in temperature. In the context of this embodiment, the electrical conductivity (o) of the at least one conductive additive therefore preferably increases with an increase in temperature.

[0033] It is recommended that the at least one insulating filler has an electrical conductivity (σ) which is less than 10 -8< S·cm -1< , preferably less than 10 -10< S·cm -1<.

[0034] The invention is explained in more detail below using an exemplary embodiment. According to a highly proven embodiment, the enameled wire according to the invention has the following layer sequence (from inside to outside): A) Conductor core made of copper and / or aluminum B) at least one Neutral functional layer of at least one lacquer polymer from the group "polyester, polyesterimide, polyamideimide", in particular polyesterimide and / or polyamideimide, preferably without conductive additives and preferably without insulating fillers, C) at least one Insulating functional layerof at least one lacquer polymer from the group "polyester, polyesterimide, polyamideimide", in particular polyesterimide and / or polyamideimide, and at least one insulating filler distributed therein from the group "mica, kaolin, corundum, high-grade corundum, silicate, aluminum oxide, sulfate, silicon dioxide, titanium dioxide", D) at least one Conductive functional layer of at least one lacquer polymer from the group "polyester, polyesterimide, polyamideimide", in particular polyesterimide and / or polyamideimide, and at least one conductive additive distributed therein from the group "carbide, silicide, nitride, oxide, titanate", preferably carbide and / or transition metal nitride, C) at least one Insulating functional layer of at least one lacquer polymer from the group "polyester, polyesterimide, polyamideimide", in particular polyesterimide and / or polyamideimide, and at least one insulating filler distributed therein from the group "mica, kaolin, corundum, high-grade corundum, silicate, aluminum oxide, sulfate, silicon dioxide, titanium dioxide".

[0035] According to a preferred embodiment, at least one further conductive functional layer D) can adjoin the last-mentioned at least one insulating functional layer C), and it is recommended that at least one further insulating functional layer C) can adjoin it. In principle, further conductive functional layers D) and insulating functional layers C) can adjoin it towards the outside, with these conductive functional layers D) and insulating functional layers C) preferably being arranged in alternating order. - According to a further preferred embodiment of the invention, at least one conductive functional layer D) can initially directly adjoin the aforementioned at least one neutral functional layer B), and at least one insulating functional layer C) can adjoin it, with at least one further conductive functional layer D) being adjoined to this last-mentioned insulating functional layer according to a proven embodiment.Here, too, further insulating functional layers C) and conductive functional layers D) can be applied to the outside, preferably in an alternating sequence. It is within the scope of the invention for a final layer to adjoin the alternating sequence of insulating functional layers and conductive functional layers as the outer layer of the electrical insulating varnish, with this final layer being expediently designed as an insulating functional layer C) or as a neutral functional layer B). Very preferably, the final layer is designed as a neutral functional layer.

[0036] The invention is based on the finding that the enameled wire according to the invention is characterized by an advantageously thin insulating coating that nevertheless satisfactorily meets all requirements placed on it—for example, with regard to electrical properties such as dielectric strength. The layer thickness of the electrical insulating varnish is only 20% to 80% of the layer thicknesses known from practice for electrical insulating varnishes. Consequently, the inventive design of the electrical insulating varnish, and in particular the special design and / or arrangement of the functional layers, allows a significant reduction in the layer thickness compared to the enameled wires known from practice to be achieved in a surprisingly simple and functionally reliable manner.It is worth emphasizing in this context that the reduction in layer thickness allows for significantly improved slot fill factors in the production of winding bodies from the enameled wire according to the invention. This also significantly increases the efficiency and energy efficiency of components or machines containing a winding body made with the enameled wire according to the invention. The enameled wire according to the invention is characterized in particular by its simple structure and, in this context, by its advantageously low manufacturing costs.By using at least one conductive additive and / or at least one insulating filler in corresponding functional layers, a surprisingly high dielectric strength of the electrical insulating varnish can be achieved, so that the enameled wire meets the requirements for electrical properties despite a significantly thinner insulation layer or electrical insulating varnish layer compared to the enameled wires known from practice. The enameled wire according to the invention therefore offers an optimal compromise between a low thickness of the electrical insulating varnish applied to the conductor core and the required electrical properties that the enameled wire must meet.

[0037] The invention is explained in more detail below with reference to a drawing that represents only one exemplary embodiment. The single figure shows a schematic cross-section through an enameled wire according to the invention.

[0038] The figure shows an enamelled wire comprising a conductor core 1, where the conductor core 1 preferably and in the exemplary embodiment consists or consists essentially of copper. According to a preferred embodiment and in the exemplary embodiment, the conductor core 1 a diameter (d K ) of about 0.2 mm. The surface of the conductor core 1 is preferred and in the embodiment completely covered with an electrical insulating varnish 2 coated, whereby the electrical insulating varnish 2 based on at least one paint polymer 3 Conveniently and in the exemplary embodiment, the lacquer polymer 3 based on polyesterimide.

[0039] According to the invention, directly on the conductor core 1 a neutral functional layer as a base layer 9 applied, which preferably and in the exemplary embodiment consists of the at least one lacquer polymer 3On this base layer 9 is preferred and in the embodiment an insulating functional layer 6 with an insulating filler 7 applied, whereby the insulating filler 7 expediently and in the embodiment according to the figure homogeneous or essentially homogeneous in the insulating functional layer 6 On this insulating functional layer 6 is preferably and in the embodiment a conductive layer 4 with a conductive additive 5 applied, whereby the conductive additive 5 preferably homogeneous or essentially homogeneous in the conductive layer 4 According to the recommended embodiment and in the exemplary embodiment, the conductive function layer 4 an insulating functional layer 6 with an insulating filler 7 applied and on this insulating functional layer 6is in turn a conductive function layer 4 with a conductive additive 5 Expediently and in the exemplary embodiment, the conductive function layers 4 and the insulating functional layers 6 therefore arranged in alternating layers.

[0040] It has proven useful that a final layer 10 as the outer layer of the electrical insulating varnish 2 which is preferably and in the exemplary embodiment provided as a neutral functional layer. The final layer is recommended 10 or the final layer formed as a neutral functional layer made of polyamideimide or essentially of polyamideimide. In the exemplary embodiment shown in the figure, the enamelled wire thus has six functional layers. In the exemplary embodiment, the total layer thickness (d E ) of the electrical insulation varnish may be 2 20 µm. The ratio of the diameter (d K ) of the conductor core1 to the total layer thickness (d E ) of the electrical insulating varnish 2 is then preferably and in the embodiment according to the figure about 10.

Claims

1. An enamelled wire, having a conductor core (1), wherein the surface of the conductor core (1) is completely, or substantially completely, coated with an electrical insulation varnish (2), wherein the electrical insulation varnish (2) is based on at least one varnish polymer (3), wherein the electrical insulation varnish (2) comprises a plurality of functional layers, wherein as functional layer(s) - at least one conductive functional layer (4) with at least one conductive additive (5) is provided - and at least one insulating functional layer (6) with at least one insulating filler (7) is provided - and at least one neutral functional layer (8) is provided that is free of conductive additives (5) and free of insulating fillers (7) and consists of the at least one varnish polymer (3) or substantially of the at least one varnish polymer (3), wherein a neutral functional layer (8) is applied directly to the conductor core (1) as a base layer (9), wherein at least one conductive functional layer (4) and at least one insulating functional layer (6) are applied to this base layer (9) and wherein the ratio of the diameter (dK) of the conductor core (1) to the total layer thickness (dE) of the electrical insulation varnish (2) is greater than, or equal to, three.

2. The enamelled wire according to Claim 1, wherein the at least one conductive additive (5) and the at least one insulating filler (7) are each arranged in separate functional layers (4, 6).

3. The enamelled wire according to Claim 2, wherein the electrical insulation varnish (2) comprises at least two conductive functional layers (4) and / or at least two insulating functional layers (6), wherein the functional layers (4, 6) are preferably arranged in an alternating sequence of layers.

4. The enamelled wire according to any one of Claims 1 to 3, wherein the electrical insulation varnish (2) comprises at least five, preferably at least six, functional layers (4, 6, 8) and / or wherein the electrical insulation varnish (2) comprises a maximum of 40, preferably a maximum of 35, particularly preferably a maximum of 30, functional layers (4, 6, 8) .

5. The enamelled wire according to any one of Claims 1 to 4, wherein the layer thickness of a functional layer (4, 6, 8) is between 0.5 µm and 15 µm, preferably between 1 µm and 10 µm, particularly preferably between 2 µm and 5 µm.

6. The enamelled wire according to any one of Claims 1 to 5, wherein the base layer (9) is designed as a layer assembly made up of at least two neutral functional layers (8).

7. The enamelled wire according to any one of Claims 1 to 6, wherein the total layer thickness (dE) of the electrical insulation varnish (2) is between 2 µm and 200 µm, preferably between 3 µm and 150 µm, particularly preferably between 3.5 µm and 120 µm.

8. The enamelled wire according to any one of Claims 1 to 7, wherein the conductive additive (5) is selected from the group: "inorganic semiconductor material, organic semiconductor material, conductive carbon material."9. The enamelled wire according to any one of Claims 1 to 8, wherein the conductive additive (5) is a ceramic semiconductor material, preferably selected from the group: "carbides, silicides, nitrides, oxides, titanates", preferably a carbide and / or nitride, more preferably a silicon carbide and / or a transition metal nitride, particularly preferably an early transition metal nitride, and is selected, for example, from the group: "titanium nitrides, zirconium nitrides, hafnium nitrides, vanadium nitrides, niobium nitrides, tantalum nitrides, chromium nitrides, molybdenum nitrides, tungsten nitrides."10. The enamelled wire according to any one of Claims 1 to 9, wherein the conductive additive (5) is selected from the group: "carbon blacks, carbon nanotubes, fullerenes, graphene, graphite, glassy carbons".

11. The enamelled wire according to any one of Claims 1 to 10, wherein the conductive additive (5) is a II-VI semiconductor, preferably a zinc sulphide or zinc oxide.

12. The enamelled wire according to any one of Claims 1 to 11, wherein the insulating filler (7) is an inorganic substance and preferably selected from the group: "mica, kaolin, corundum, synthetic corundum, silicates, aluminium oxides, sulphates, silicon dioxides, titanium dioxides".

13. The enamelled wire according to any one of Claims 1 to 12, wherein the insulating filler (7) is a surface-modified silicate, preferably a silanized silicate, particularly preferably a silicate modified with at least one component from the group: "aminosilane, epoxysilane, methacrylsilane, trimethylsilane, methylsilane, vinylsilane".

14. The enamelled wire according to any one of Claims 1 to 13, wherein the varnish polymer (3) is based on at least one component from the group: "polyester, polyesterimide, polyesteramideimide, polyurethane, polyamide, polyamideimide, polyimide", preferably based on at least one component from the group: "polyester, polyesterimide, polyamideimide" and particularly preferably based on polyesterimide.

15. The enamelled wire according to any one of Claims 1 to 14, wherein a conductive functional layer (4) contains between 0.05 wt.% and 15 wt.%, preferably between 0.1 wt.% and 10 wt.%, more preferably between 0.2 wt.% and 5 wt.% and most preferably between 0.3 wt.% and 3 wt.% of the conductive additive (5) and / or wherein an insulating functional layer (6) contains between 0.05 wt.% and 15 wt.%, preferably between 0.1 wt.% and 10 wt.%, more preferably between 0.2 wt.% and 5 wt.% and most preferably between 0.3 wt.% and 3 wt.% of the insulating filler (7).

16. The enamelled wire according to any one of Claims 1 to 15, wherein a conductive functional layer (4) of the liquid, uncured electrical insulation varnish (2) contains between 0.001 wt.% and 10 wt.%, preferably between 0.005 wt.% and 5 wt.%, more preferably between 0.01 wt.% and 3 wt.% and most preferably between 0.01 wt.% and 1 wt.% of the conductive additive (5) and / or wherein an insulating functional layer (6) of the liquid, uncured electrical insulation varnish (2) contains between 0.001 wt.% and 10 wt.%, preferably between 0.005 wt.% and 5 wt.%, more preferably between 0.01 wt.% and 3 wt.% and most preferably between 0.01 wt.% and 1 wt.% of the insulating filler (7).

17. The enamelled wire according to any one of Claims 1 to 16, wherein the conductive additive (5) is homogeneously or substantially homogeneously distributed within the respective conductive functional layer (4) and / or wherein the insulating filler (7) is homogeneously or substantially homogeneously distributed within the respective insulating functional layer (6).

18. The enamelled wire according to any one of Claims 1 to 17, wherein the at least one conductive additive (5) exhibits an electrical conductivity (σ) at room temperature of between 10-10 S·cm-1 and 106 S·cm-1, preferably between 10-8 S·cm-1 and 104 S·cm-1 and / or wherein the specific resistance (ρ) of the at least one conductive additive (5) has a negative temperature coefficient.