Data cable

Abstract

Proposed is a data cable (1) for transmitting data in the telecommunications, information transmission or computer technology sectors, comprising two wires (2), wherein each wire (2) has - a conductor (3) and - an insulation layer (4), wherein the insulation layer (4) of each wire (2) has the same color additive comprising the same colorant. In order to allow improved signal transmission despite differently colored wires (2), the invention provides for an outer region (11) of the insulation layer (4) of one wire (2) to additionally have a further color additive comprising other colorants, and for an outer region (11) of the insulation layer (4) of the other wire (2) to be free of the further color additive and free of another color additive.

Description

[0001] DATA CABLE

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a data cable for transmitting data in telecommunications, message transmission or computer technology, comprising two wires, each wire

[0004] - a leader and

[0005] - has an insulation layer, wherein the insulation layer of each wire has the same color additive comprising the same colorants.

[0006] STATE OF THE ART

[0007] Data cables, especially those with high data transmission rates, typically comprise one or more pairs of wires and are used to connect a transmitter and a receiver, transmitting signals (electromagnetic waves) that are then further processed. Bidirectional communication is usually possible, i.e., the transmitter becomes the receiver and vice versa.

[0008] The signals can be transmitted either by means of differential signal transmission, which is a symmetrical transmission with signals in antiphase, or by means of common-mode signal transmission, which is also a symmetrical transmission but with signals in phase.

[0009] Each wire pair in a data cable comprises two conductors and two insulating layers, each surrounding one of the two conductors. In order to be able to process the wire pairs fully automatically, the two wires of a wire pair must have different colors (externally), which is why the insulating layers are coated with corresponding colored layers. However, the different colors used in the colored layers have different dielectric values ​​due to their ingredients, in particular their color pigments. These values ​​mean that signals propagate at different speeds and are attenuated differently in the two wires. This means that the signals in the two wires propagate at different speeds and are attenuated differently over the length of the data cable. This means that the signals propagate in the two wires over the length of the data cable is not symmetrical or are offset from one another. This means, among other things, that the signal propagation times are different, which impairs the transmission of the signals and data.This is called mode conversion , which is usually a measure of how good the quality of the signal transmission is .

[0010] US 5 187 329 A, US 1 968 903 A, WO 2018 / 197365 A1, US 5 281 764 A and US 2010 / 307790 A1 all disclose cables with two cores, wherein the insulation layer of each core is surrounded by a colored layer, wherein the colored layers of the two cores have different colors.

[0011] OBJECT OF THE INVENTION

[0012] It is therefore an object of the present invention to provide a data cable for transmitting data in telecommunications, message transmission or computer technology, which overcomes the disadvantages of the prior art and enables improved signal transmission despite differently colored wires.

[0013] PRESENTATION OF THE INVENTION

[0014] This task is carried out in a data cable for transmitting data in telecommunications, message transmission or computer technology, comprising two wires, each wire

[0015] - a leader and

[0016] - has an insulation layer, wherein the insulation layer of each wire has the same color additive comprising the same colorants, achieved according to the invention in that an outer region of the insulation layer of one wire additionally has a further color additive comprising other colorants and an outer region of the insulation layer of the other wire is free of the further color additive and free of a further color additive.

[0017] In the data cable according to the invention, the insulation layer of each core contains the same color additive comprising the same colorants. In addition, the outer region of a core contains a further color additive comprising different colorants than those colorants contained in the color additive with which the insulation layer of each core is provided. The outer region of the other core is free of the further color additive comprising other colorants and free of all other color additives comprising the other colorants and / or further colorants. This means that the outer region of the insulation layer of the other core contains no further color additive. The outer region therefore only has the color additive and no other color additive.

[0018] The outer region of the insulation layer is therefore the region which is located furthest outward in a radial direction in the cross-section of the data cable according to the invention.

[0019] Adding the same color additive to the insulation layer of each core ensures that the properties of the cores, especially the attenuation properties, remain consistent – ​​the cores are thus standardized or synchronized. Adding the additional color additive to the outer area of ​​the insulation layer of one core ensures that one core of the data cable according to the invention is visually visible in a different color than the other core – this ensures fully automated further processing.However, since only the outer region of the insulation layer of one core is provided with the additional color additive (the outer region of the insulation layer of the other core is free of the additional color additive and free of a further color additive), the signal transmission properties, in particular the attenuation properties, of this one core are essentially unchanged or only slightly changed compared to the other core. This means that in the data cable according to the invention, the signal transmission properties of the cores are matched to one another as far as possible, despite two different colors being visually visible between the cores, which enables significantly improved signal transmission compared to the prior art.In other words, the coloring of the outer area of ​​the insulation layer of one wire is sufficient to ensure fully automatic further processing, while at the same time the delay of the signals is influenced as little as possible.

[0020] It is conceivable, for example, that the data cable according to the invention comprises two cores, wherein the insulation layers of both cores are provided with the same color additive comprising white colorants. In addition, the outer region of the insulation layer of one of the two cores contains another color additive with green colorants. Thus, the two cores appear visually in different colors. One core is visually visible as white, while the other core appears visually green, although the use of other color combinations is of course not excluded.

[0021] The term colorant in this context refers to a coloring substance. For example, the colorants can be color pigments that are essentially insoluble in the application medium - in the context of this invention in the insulation layers - and act as

[0022] Solid particles are present, whereby the color is created by absorption and remission (scattering or reflection) of certain frequency components of visible light.

[0023] Of course, the color pigments can also be a mixture of "different" color pigments to achieve a specific shade. Furthermore, it would also be possible to use (liquid) colorants that are soluble in the application medium, for example, a polymer.

[0024] The color additives, due to the colorants, at least color the insulation layers. However, both the color additive, which all insulation layers contain, and the additional color additive can, of course, also contain other additives in addition to the colorants, allowing the insulation layers to be optimally adapted to the respective application.

[0025] For example, the color additives may contain – in addition to the colorant – a carrier material, age inhibitors, dispersants, fillers, compatibilizers, light stabilizers, processing aids or lubricants, and / or nucleating agents. The carrier material may be a polymer or a mixture of polymers that is usually identical to the application medium. Alternatively, it may be a polymer or a mixture of polymers that is compatible with the application medium and has no significantly negative influence on its properties. Antioxidants are usually used as age inhibitors, which prevent or reduce degradation of the carrier material or any other ingredients of the color additives during processing and use.Dispersing agents improve the mixability and dispersibility of the colorants in the carrier material, while fillers, which are usually mineral flours, increase the opacity of the color additives and improve their economic producibility.

[0026] Compatibilizers improve the compatibility of color additives with the application medium and / or the colorant with the carrier material. Light stabilizers are UV stabilizers that prevent or reduce degradation of the polymer and / or colorant. Processing agents or lubricants can reduce "production pressure" in the machines and enable better processability. Nucleating agents are nucleating agents that influence the product properties of the final products. Of course, the use of other additives, such as antistatic agents, antiblocking agents, optical brighteners, effect pigments, etc., is also possible.

[0027] Of course, it is not excluded that the data cable according to the invention has more than two wires. For example, the data cable can have three, four, five, six, or even more wires, wherein the outer region of the insulating layer of at least one wire additionally comprises the further color additive comprising other colorants, and the outer region of the insulating layer of at least one other wire is free of the further color additive and free of a further color additive.

[0028] One factor that influences both the optical visibility of the different colors of the wires and the improved signal transmission is the thickness of the outer region of the insulation layers, in particular of the wire(s) that also contain the additional color additive. On the one hand, the outer region must be thick enough to provide sufficient volume for the additional color additive, in particular for the other colorants, so that the additional color additive, in particular the other colorants, can distribute sufficiently, and on the other hand, it must be thin enough to have as little influence as possible on the signal transmission properties, in particular the attenuation properties, of the wire - despite the addition of the additional color additive.Therefore, in one embodiment of the invention, the outer region of the insulation layer of each wire has a thickness of between 5 pm and 200 pm, preferably between 25 pm and 100 pm, particularly preferably between 40 pm and 60 pm. These thickness ranges represent the optimum in terms of sufficient coloring of the one wire while simultaneously achieving only a slight delay in the signals.

[0029] In order to achieve a coloring of one core sufficient for fully automated further processing, a further embodiment of the invention provides that the total composition of the insulation layer of one core comprises a maximum of 5 wt.%, preferably a maximum of 3 wt.%, particularly preferably a maximum of 1.5 wt.%, of the additional color additive. These amounts represent the optimum for sufficient optical visibility and only a minor influence on the signal transmission properties, in particular the attenuation properties, of the one core.

[0030] In order to manufacture the data cable according to the invention efficiently, and in particular economically, a further embodiment of the invention provides for the insulation layer of each core to be produced by extrusion. Extrusion makes it possible to create various shapes with little effort and to reliably process different materials.

[0031] In a further embodiment of the invention, the insulation layer of each core is made of polypropylene. Polypropylene is advantageous because the molecular structure, the average molecular weight, the molecular weight distribution, the crystallinity, and the spherulite structure can be varied within wide limits, thereby influencing the properties. Furthermore, the dynamic load-bearing capacity of polypropylene is high, making the material suitable for a wide range of applications. In addition, the dielectric constant and the dielectric loss factor are largely independent of temperature. In a further embodiment of the invention, the insulation layer of each core

[0032] - an inner insulation layer covering at least part of an outer surface of the conductor, and

[0033] - an outer insulation layer which covers an outer surface of the inner insulation layer at least in sections, wherein the outer insulation layer comprises the outer region. This means that both the inner insulation layer and the outer insulation layer of each core are provided with the same color additive comprising the same colorants. In addition, the outer insulation layer in one core comprises the outer region of the insulation layer, which outer region additionally has the further color additive comprising other colorants. In particular, the outer insulation layer consists of the outer region of the insulation layer.

[0034] The outer insulation layer gives the data cable according to the invention stability and serves as protection against the environment.

[0035] Particularly when parts of the insulation layers are made, at least in sections, of a foamed material, it is sometimes necessary to separate the foamed material from the conductors. Therefore, in a further embodiment of the invention, it is provided that the inner insulation layer of each wire

[0036] - an inner skin layer covering at least part of the outer surface of the conductor, and

[0037] - a main layer which covers the inner skin layer at least in sections.

[0038] It is conceivable that the main layer is made, at least in sections, of a foamed material, and the inner skin layer is made of a different material, with the inner skin layer serving as a separation between the conductor and the main layer. This means that it separates the main layer from the conductor, provides a certain degree of stability, and adheres accordingly to the conductor.

[0039] A main layer of foamed material ensures optimal transmission properties of the data cable according to the invention.

[0040] In a further embodiment of the invention, the data cable is a "shielded twisted pair" data cable. This variant of the data cable according to the invention has shielding, which very effectively prevents interference from entering (or leaving) the cable. In addition, the wires of at least one wire pair are crossed, twisted or stranded. The advantage of crossed, twisted or stranded wire pairs is that external noise or interference signals are coupled as evenly as possible into both wires of the wire pair. While coupled interference then changes the signals on the wires, the difference between the signals is only slightly changed. A combination of braiding and shielding has proven to be very effective in reducing internal and external electromagnetic influences.

[0041] In a further embodiment of the invention, the data cable is a "shielded parallel pair" data cable. Here, the wires of at least one wire pair run essentially parallel to one another. At the same time, shielding is provided. The advantage of this embodiment is that the data cable is very flexible due to the wires running parallel to one another, which makes it easy to install.

[0042] In a further embodiment of the invention, it is provided that the data cable is an "unshielded twisted pair" data cable. This variant of the data cable according to the invention has twisted wires of each wire pair, but no shielding. This is the "simplest" version of a "twisted pair" cable, whereby in particular the economic

[0043] Manufacturability is advantageous.

[0044] SHORT DESCRIPTION OF THE CHARACTERS

[0045] The invention will now be explained in more detail using exemplary embodiments. The drawings are examples and are intended to illustrate the inventive concept, but in no way restrict it or represent it exhaustively.

[0046] It shows:

[0047] Fig. 1 is a schematic sectional view of a wire pair of a data cable according to the prior art;

[0048] Fig. 2 shows a schematic mode conversion curve of the data cable according to the prior art;

[0049] Fig. 3 is a schematic sectional view of a wire pair of a first embodiment of a data cable according to the invention;

[0050] Fig. 4 is a schematic mode conversion curve of the first embodiment of the data cable according to the invention;

[0051] Fig. 5 is a schematic sectional view of a wire pair of a second embodiment of the data cable according to the invention.

[0052] WAYS OF IMPLEMENTING THE INVENTION

[0053] Fig. 1 shows a schematic sectional view of a wire pair, i.e. two wires 2, of a data cable 1 for transmitting data in telecommunications, message transmission or computer technology according to the prior art. Each of the two wires 2 has a conductor 3 and an insulation layer 4 comprising an inner insulation layer 5 and an outer insulation layer 6, which is formed by an outer region 11 of the insulation layer 4, wherein the inner insulation layer 5 covers an outer surface 7 of the conductor 3 and the outer insulation layer 6 covers an outer surface 8 of the inner insulation layer 5. I.e. the inner insulation layer 5 is arranged between the conductor 3 and the outer insulation layer 6.

[0054] To allow for fully automated processing, the wires 2 are colored differently. One of the two wires 2 is visually visible in green (left wire 2 in Fig. 1), while the other of the two wires 2 is visually visible in white (right wire 2 in Fig. 1).

[0055] To achieve different optical visibility of the two cores 2, the insulation layer 4 of one core 2 is provided with green colorants (the green colorants are symbolized by the dots in the insulation layer 4) and the insulation layer 4 of the other core 2 is provided with white colorants. This means that for both cores 2, both the inner insulation layer 5 and the outer insulation layer 6 contain different colorants.

[0056] These different colorants have different dielectric values, which cause the signals in the two wires 2 to propagate at different speeds and to be attenuated differently. This results in the signals in the two wires 2 being non-symmetrical to each other over the length of the data cable 1, which, among other things, results in different signal propagation times. This is called mode conversion.

[0057] Fig. 2 shows a mode conversion curve of the data cable 1 according to the prior art. The TCTL parameter (Transverse Conversion Transfer Loss) is plotted against frequency, with the TCTL parameter being a measure of the asymmetrical attenuation (i.e., mode conversion) of a data cable 1. This means that the lower the TCTL parameter, the better the attenuation properties of the data cable 1 and the better (more symmetrical) the signal transmission between the wires 2 of the data cable 1.

[0058] In Fig. 2, three lines are visible, namely a TCTL parameter 13 for each of the two wires 2 of the data cable 1 according to the prior art, and a limit line 12. To ensure good signal transmission, the TCTL parameters 13 of both wires 2 should be arranged below the limit line 12 across the entire frequency range. It can be seen from Fig. 2 that this is not the case with the data cable 1 according to the prior art. Between 20 and 30 MHz, the TCTL parameters 13 of both wires 2 exceed the limit line 12 and then remain permanently above the limit line 12. This means that at frequencies greater than or equal to 20-30 MHz, the limit line 12 is exceeded by the TCTL parameters 13. This means that with the data cable 1 according to the prior art, there are significant delay shifts in the signals in the two wires 2 in the higher frequency range - this means that asymmetrical signal transmission takes place.

[0059] Fig. 3 shows a schematic sectional view of a wire pair, i.e., two wires 2, of a first exemplary embodiment of a data cable 1 according to the invention. The structure of the first exemplary embodiment of the data cable 1 according to the invention, in particular of the insulation layers 4, essentially corresponds to the structure of the data cable 1 shown in Fig. 1 according to the prior art. Although only two wires 2 are shown in Fig. 3, it is not excluded that the data cable 1 also has more wires 2, for example, three, four, five, six, or more wires 2.

[0060] However, the coloring of the insulation layers 4 is different. In the first exemplary embodiment of the data cable 1 according to the invention, the insulation layers 4 of the two wires 2, i.e. both the inner insulation layers 5 and the outer insulation layers 6, which outer insulation layers 6 are formed from the outer region 11 of the insulation layers 4 and have a thickness of substantially 50 μm in the first exemplary embodiment, each have the same color additive comprising the same white colorants. In addition, the outer insulation layer 6 of one of the two wires 2 (left wire 2 in Fig. 3) comprises a further color additive comprising green colorants. The outer insulation layer 6 of the other of the two wires 2 (right wire 2 in Fig. 3) is free of the further color additive and free of a further color additive. Thus, one wire 2 is optically visible as green (left wire 2 in Fig.3) and the other wire 2 is visually visible in white (right wire 2 in Fig. 3).

[0061] In this embodiment, the total compositions of the insulation layers 4 of the two wires 2 each comprise 1 wt.% of the color additive comprising white colorants. In addition, the total composition of the left-hand wire in Fig. 3 comprises 1.78 wt.% of the further color additive, wherein the further color additive in this case is composed of the same amount of white colorants and green colorants. This means that the further color additive comprises the same amount of white colorants in addition to the green colorants. This means that the data cable 1 according to the invention can be further processed fully automatically, and on the other hand, the signal transmission properties of the wire 2, which is optically visible as green, are only slightly affected compared to the wire 2, which is optically visible as white.

[0062] The insulation layers 4 of both wires 2 of the first embodiment are made of polypropylene by extrusion.

[0063] Fig. 4 shows a mode conversion curve of the first embodiment of the data cable 1 according to the invention. Here, too, the TCTL parameter is plotted against the frequency, exactly as in Fig. 2. Three lines are also visible in Fig. 4, namely a TCTL parameter 13 for each of the two wires 2 and the boundary line 12 known from Fig. 2.

[0064] From Fig. 4 it can be seen that in the data cable 1 according to the invention, the TCTL parameters 13 of both wires 2 are well below the limit line 12 over the entire frequency range. Thus, the signal transmission properties of the two wires 2 of the first embodiment of the data cable 1 according to the invention are well matched to one another - despite the optical visibility of different colors (one wire 2 is optically visible green, the other wire 2 white), which enables significantly improved signal transmission compared to the prior art.

[0065] Fig. 5 shows a schematic sectional view of a wire pair, i.e. two wires 2, of a second exemplary embodiment of the data cable 1 according to the invention. The second exemplary embodiment corresponds to the first exemplary embodiment of the data cable 1 according to the invention with the difference that the inner insulation layers 5 of the two wires 2 have an inner skin layer 9 and a main layer 10, wherein the inner skin layer 9 is arranged between the conductor 3 and the main layer 10. The inner skin layer serves as a separation between the conductor 3 and the main layer 10 and provides stability.

[0066] Both the first embodiment of the data cable 1 according to the invention and the second embodiment of the data cable 1 according to the invention can be designed as a "shielded twisted pair" data cable 1, a "shielded parallel pair" data cable 1, or an "unshielded twisted pair" data cable 1. LIST OF REFERENCE SYMBOLS

[0067] 1 data cable

[0068] 2 core 3 conductor

[0069] 4 I solat ions layer

[0070] 5 Inner insulation layer

[0071] 6 Outer insulation layer

[0072] 7 Outer surface of the conductor 3 8 Outer surface of the inner insulation layer 5

[0073] 9 inner skin layer

[0074] 10 Main layer

[0075] 11 outer area of ​​the insulation layer 4

[0076] 12 Limit line 13 TCTL parameter of one of the wires 2 of the data cable 1

Claims

PATENT CLAIMS Data cable (1) for transmitting data in telecommunications, message transmission or computer technology, comprising two wires (2), each wire (2) - a conductor (3) and - has an insulation layer (4), wherein the insulation layer (4) of each core (2) has the same color additive comprising the same colorants, characterized in that an outer region (11) of the insulation layer (4) of one core (2) additionally has a further color additive comprising other colorants, and an outer region (11) of the insulation layer (4) of the other core (2) is free of the further color additive and free of a further color additive. Data cable (1) according to claim 1, characterized in that the outer region (11) of the insulation layer (4) of each core (2) has a thickness of between 5 pm and 200 pm, preferably between 25 pm and 100 pm, particularly preferably between 40 pm and 60 pm. Data cable (1) according to one of claims 1 to 2, characterized in that a total composition of the insulation layer (4) of the one wire (2) is a maximum of 5 wt.%, preferably a maximum of 3 wt.%, particularly preferably a maximum of 1.5 wt.%, further comprising a color additive. Data cable (1) according to one of claims 1 to 3, characterized in that the insulation layer (4) of each wire (2) is produced by extrusion. Data cable (1) according to one of claims 1 to 4, characterized in that the insulation layer (4) of each wire (2) is made of polypropylene. Data cable (1) according to one of claims 1 to 5, characterized in that the insulation layer (4) of each wire (2) - an inner insulation layer (5) having an outer surface (7) of the conductor (3) is covered at least in sections, and - an outer insulation layer (6) having an outer surface (8) of the inner insulation layer (5) at least partially covers, wherein the outer insulation layer (6) covers the outer region (11). Data cable (1) according to claim 6, characterized in that the inner insulation layer (5) of each wire (2) - an inner skin layer (9) which covers the outer surface (7) of the conductor (3) at least in sections, and - a main layer (10) which covers the inner skin layer (9) at least in sections. Data cable (1) according to one of claims 1 to 7, characterized in that the data cable (1) is a "shielded twisted pair" data cable. Data cable (1) according to one of claims 1 to 7, characterized in that the data cable (1) is a "shielded parallel pair" data cable. Data cable (1) according to one of claims 1 to 7, characterized in that the data cable (1) is an "unshielded twisted pair" data cable.

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