Shielded wire and conductive nonwoven tape

Abstract

To provide a shield wire and conductive nonwoven tape, capable of suppressing reduction in shield effect.SOLUTION: A shield wire 1 is obtained by spirally winding a conductive nonwoven tape 20 including a conductive nonwoven fabric and an adhesive layer around a wire 10. The conductive nonwoven tape 20 is spirally wound at a winding pitch of t / 3 or more and t / 2 or less around the wire 10 when setting the width to t so as to include a lap part; the adhesive layer positioned on the outside of the lap part has an adhesive power of 0.6 [N / 19 mm] or more to the wire 10, a width w of≥t / 10 and a thickness of 0.01 mm or more and equal to or less the thickness of the conductive nonwoven fabric.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a shielded wire and a conductive nonwoven tape. [Background technology]

[0002] Conventionally, a shielded electric wire has been proposed in which a conductive nonwoven fabric having a nonwoven fabric and a metal layer formed on the surface of the nonwoven fabric is arranged around the outer periphery of an electric wire (see, for example, Patent Document 1). This shielded electric wire exhibits an electromagnetic shielding effect due to the metal layer of the conductive nonwoven fabric, while the nonwoven fabric has relatively excellent stretching and compressing properties due to the characteristics of the material, and can follow the bending of the electric wire. Such a conductive nonwoven fabric is made into a conductive nonwoven fabric tape by providing an adhesive layer on one surface (see, for example, Patent Documents 2 and 3), and can be attached around the electric wire using the adhesive layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-75375 A [Patent Document 2] JP 2021-140950 A [Patent Document 3] Patent Publication No. 2021-103775 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the conductive nonwoven tape described in Patent Documents 2 and 3 is attached vertically around an electric wire, the lapped portion of the conductive nonwoven tape may open when the wire is bent, reducing the shielding effect. Also, when the conductive nonwoven tape is wound in a spiral shape, the lapped portion also becomes spiral and is less likely to open when the wire is bent, but since an adhesive layer is interposed between the upper and lower conductive nonwoven fabrics in the lapped portion, the conductive path also becomes spiral, resulting in a significant reduction in the shielding effect.

[0005] The present invention has been made to solve these conventional problems, and an object of the present invention is to provide a shielded wire and a conductive nonwoven fabric tape that can suppress a decrease in the shielding effect. [Means for solving the problem]

[0006] The shielded electric wire according to the present invention is a shielded electric wire in which a conductive nonwoven fabric tape having a conductive nonwoven fabric and an adhesive layer formed on one side of the conductive nonwoven fabric is spirally wound around an electric wire, and the conductive nonwoven fabric tape has a width t of: The one surface faces the electric wire. A spiral winding is performed around the electric wire with a winding pitch of t / 3 or more and t / 2 or less. A portion in the width direction of the conductive nonwoven fabric tape, where the conductive nonwoven fabrics overlap on the one surface. The adhesive layer is wound around the electric wire with a lap portion, the adhesive layer is located outside the lap portion, the adhesive strength to the electric wire is 0.6 [N / 19 mm] or more, and the width w of the adhesive layer but t / 10 More than winding pitch and has a thickness of 0.01 mm or more and less than the thickness of the conductive nonwoven fabric.

[0007] The conductive nonwoven fabric tape according to the present invention is a conductive nonwoven fabric tape having a conductive nonwoven fabric, which is a nonwoven fabric having electrical conductivity, and an adhesive layer formed on one side of the conductive nonwoven fabric, wherein the adhesive layer has an adhesive strength of 2.0 [N / 19 mm] or more, and the width w of the adhesive layer is 1.0 mm or less, where t is the overall width of the conductive nonwoven fabric tape. but t / 10 More than t / 2 or less It is formed on one side in the width direction and has a thickness of 0.01 mm or more and less than the thickness of the conductive nonwoven fabric. Effect of the Invention

[0008] According to the present invention, there are provided a shielded wire and a conductive nonwoven fabric tape capable of suppressing a decrease in the shielding effect. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a shielded wire according to an embodiment of the present invention. [Diagram 2] 2A and 2B are diagrams showing the configuration of the conductive nonwoven fabric tape shown in FIG. 1, in which (a) shows a cross section perpendicular to the longitudinal direction of the tape, and (b) shows a partially enlarged view. [Diagram 3] 2 is a cross-sectional view taken along the longitudinal direction of the shielded electric wire shown in FIG. 1. [Figure 4] 1A and 1B are conceptual diagrams showing how a magnetic field is generated, in which (a) shows the state of the magnetic field in the first reference example, and (b) shows the state of the magnetic field in this embodiment. [Diagram 5] 13 is an image diagram showing the degree of opening when bent depending on the thickness of the adhesive layer, where (a) shows the state of the second reference example, and (b) shows the state of this embodiment. FIG. [Figure 6] 4 is a graph showing the shielding performance of the shielded wire according to the present embodiment and a shielded wire according to a reference example. [Figure 7] 1 is a table showing details of conductive nonwoven tapes used in Examples and Comparative Examples. [Figure 8] 1 is a first table showing examples and comparative examples. [Figure 9] 2 is a second table showing examples and comparative examples. [Figure 10] 3 is a third chart showing examples and comparative examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described below along with preferred embodiments. Note that the present invention is not limited to the embodiments shown below, and can be modified as appropriate within the scope of the present invention. In addition, in the embodiments shown below, some configurations are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are appropriately applied to the details of the omitted technologies within the scope of the contents described below.

[0011] Fig. 1 is a perspective view showing a shielded electric wire 1 according to an embodiment of the present invention. As shown in Fig. 1, the shielded electric wire 1 according to the present embodiment includes a single electric wire 10 and a conductive nonwoven fabric tape 20 wound around the electric wire 10 in a spiral shape.

[0012] The electric wire 10 includes a conductor 11 made of, for example, copper, aluminum, or an alloy thereof, and an insulating coating 12 that coats the conductor 11. In the example shown in Fig. 1, the conductor 11 of the electric wire 10 is a twisted wire made by twisting together a plurality of wires, but is not limited to this and may be a single wire. Also, a plurality of electric wires 10 may be provided. Furthermore, the coating 12 is assumed to be made of PVC (Polyvinyl Chloride), PP (Polypropylene), and PE (Polyethylene), but is not limited to this and may be silicone, polyurethane, nylon, etc.

[0013] Fig. 2 is a structural diagram showing the conductive nonwoven fabric tape 20 shown in Fig. 1, where (a) shows a cross section perpendicular to the tape longitudinal direction, and (b) shows a partially enlarged view. As shown in Fig. 2(a), the conductive nonwoven fabric tape 20 includes a conductive nonwoven fabric 21 and an adhesive layer 22 provided on one surface (front or back) of the conductive nonwoven fabric 21.

[0014] As shown in Fig. 2(b), the conductive nonwoven fabric 21 is configured to include fibers 21a constituting the nonwoven fabric and plated portions 21b. The nonwoven fabric is a sheet-like member in which the fibers 21a are intertwined without being woven. As shown in Fig. 2(b), due to the nature of the manufacturing process, the fibers 21a of this nonwoven fabric are formed as multiple layers in the thickness direction. The fibers 21a constituting such a nonwoven fabric are made of, for example, polyethylene terephthalate (PET), PP, nylon, acrylic, glass fiber, carbon fiber, aramid fiber, polyarylate fiber, and the like.

[0015] The plated portion 21b is a conductive metal that coats the fibers 21a that constitute the nonwoven fabric. The plated portion 21b is made of, for example, copper, nickel, tin, silver, or an alloy of these metals. The plated portion 21b may be formed in a single layer on the fibers 21a that constitute the nonwoven fabric, or may be formed in multiple layers. For this reason, the plated portion 21b may be formed, for example, with copper (first layer) and tin (second layer) on the fibers 21a that constitute the nonwoven fabric.

[0016] Fig. 3 is a cross-sectional view taken along the longitudinal direction of the shielded electric wire 1 shown in Fig. 1. As shown in Fig. 3, the adhesive layer 22 is located outside the wrap portion L when the conductive nonwoven fabric tape 20 is wrapped around the electric wire 10. That is, in this embodiment, the adhesive layer 22 is not interposed between the conductive nonwoven fabrics 21 when the conductive nonwoven fabric tape 20 is wound in a spiral shape.

[0017] 2, the adhesive layer 22 is preferably formed biasedly on one side in the width direction (the range indicated by t / 2 in FIG. 2: t is the width of the conductive nonwoven fabric tape 20), and more preferably formed in an area up to 1 / 3 of the width direction (the range indicated by t / 3 in FIG. 2).This is because the adhesive layer 22 can be positioned outside the wrap portion L when the conductive nonwoven fabric tape 20 is wrapped in a half wrap or more and a two-thirds wrap or less.

[0018] In particular, it is preferable that the adhesive layer 22 is formed from the end 21c toward the center in the width direction of the conductive nonwoven fabric 21. This is because the adhesive layer 22 can be formed closer to the end 21c side, making it easier to position the adhesive layer 22 outside the wrap portion L when the conductive nonwoven fabric tape 20 is wrapped around the electric wire 10.

[0019] The shielded wire 1 according to this embodiment has improved shielding performance compared to the first reference example in which the adhesive layer is interposed between the conductive nonwoven fabrics.

[0020] FIG. 4 is an image diagram showing the generation of a magnetic field, where (a) shows the state of the magnetic field in the first reference example, and (b) shows the state of the magnetic field in this embodiment. First, as shown in FIG. 4(a) and FIG. 4(b), a current flows in the electric wire 10 in the direction in which the conductor 11 extends. Therefore, a magnetic field MF1 (see dashed line) perpendicular to the current is generated. When an adhesive layer is interposed between the conductive nonwoven fabrics, the conductive nonwoven fabric tape forms a conductive path in a spiral shape as in the first reference example shown in FIG. 4(a). In this case, a magnetic field MF2 (see solid line) is generated in the conductive nonwoven fabric tape side in a direction perpendicular to the spiral direction. This magnetic field MF2 cannot cancel out the magnetic field MF1 generated by the current flowing through the conductor 11. On the other hand, when the adhesive layer 22 is located outside the wrap portion L as shown in FIG. 3, the conductive nonwoven fabric tape 20 forms a conductive path CP along the longitudinal direction of the electric wire 10 as shown in FIG. 4(b). Therefore, the conductive nonwoven fabric tape 20 forming this conductive path CP can generate a magnetic field MF2 (see solid line) that cancels out the magnetic field MF1 (see dashed line) generated by the current flowing through the conductor 11.

[0021] In this manner, in the shielded wire 1 according to this embodiment, the adhesive layer 22 is positioned outside the wrap portion L, thereby enabling the shielding performance to be improved.

[0022] In addition, such shielding performance needs to be ensured even when the shielded electric wire 1 is bent. In the shielded electric wire 1 according to this embodiment, the winding pitch, adhesive strength, width w of the adhesive layer, and thickness of the adhesive layer 22 of the conductive nonwoven fabric tape 20 are set as follows so that the shielding performance is ensured even when the electric wire is bent (when bent at R30).

[0023] First, in the shielded electric wire 1 according to the present embodiment, the winding pitch of the conductive nonwoven fabric tape 20 is set to t / 3 or more and t / 2 or less. Here, if the winding pitch is less than t / 3, i.e., if the lapped portion L exceeds 2t / 3, the winding of the conductive nonwoven fabric tape 20 may make the shielded electric wire 1 too hard, and bending (bending with a curvature radius of R30 or less) itself may be difficult. Also, if the winding pitch is more than t / 2, i.e., if the lapped portion L is less than t / 2, the area of ​​the lapped portion L is small, and the coating portion 12 of the electric wire 10 may be exposed when bending at R30. That is, the conductive nonwoven fabrics 21 do not overlap each other, and the conductive path CP becomes spiral. Therefore, in the shielded electric wire 1, the winding pitch of the conductive nonwoven fabric tape 20 is set to t / 3 or more and t / 2 or less.

[0024] The adhesive layer 22 has an adhesive strength of 2.0 [N / 19 mm] or more in the adhesive strength measurement method specified by JISC2107. Such an adhesive layer 22 can exert an adhesive strength of 0.6 [N / 19 mm] or more to the coating 12 of the electric wire 10 (e.g., a coating made of any one of PVC, PP, PE, silicone, polyurethane, and nylon). Furthermore, the adhesive layer 22 has a width w (see FIG. 2) of t / 10 or more. The adhesive layer 22 has the above adhesive strength and width w, so that the conductive nonwoven fabric tape 20 is less likely to slip when bent with R30.

[0025] Furthermore, the thickness of the adhesive layer 22 is 0.01 mm or more and equal to or less than the thickness of the conductive nonwoven fabric 21. If the thickness of the adhesive layer 22 is not 0.01 mm or more, it is close to the processing limit of the adhesive layer 22, making it difficult to manufacture the conductive nonwoven fabric tape 20. Also, if the thickness of the adhesive layer 22 is not equal to or less than the thickness of the conductive nonwoven fabric 21, the wrap portion L is likely to open when bending at R30, making it difficult to ensure the conductive path CP in the longitudinal direction of the electric wire.

[0026] FIG. 5 is an image diagram showing the degree of opening when bending according to the thickness of the adhesive layer, where (a) shows the state of the second reference example, and (b) shows the state of this embodiment. First, in the second reference example shown in FIG. 5(a), the thickness AT of the adhesive layer 122 exceeds the thickness of the conductive nonwoven fabric 121. Therefore, the conductive nonwoven fabric 121 is in a state of being separated from the covering portion 12, and the contact pressure between the conductive nonwoven fabrics 121 tends to be low. In addition, as shown in FIG. 5(a), if the adhesive layer 122 is not interposed in the wrap portion L, the conductive nonwoven fabric tape rotates so as to separate from the covering portion 12 on the outside of the bend when bending. Here, in the second reference example shown in FIG. 5(a), the thickness AT of the adhesive layer 122 exceeds the thickness of the conductive nonwoven fabric 121, so the amount of rotation of the conductive nonwoven fabric 121 when rotating tends to be large.

[0027] On the other hand, in the present embodiment shown in Fig. 5(b), the thickness AT of the adhesive layer 22 is equal to or less than the thickness of the conductive nonwoven fabric 21. Therefore, the conductive nonwoven fabric 21 is located close to the electric wire 10, and the contact pressure between the conductive nonwoven fabrics 21 tends to increase. In addition, as shown in Fig. 5(b), when bending, the conductive nonwoven fabric tape rotates so as to move away from the covering portion 12 on the outside of the bend, but the amount of this rotation also tends to be small. Therefore, in the shielded electric wire 1 according to the present embodiment, by making the thickness AT of the adhesive layer 22 equal to or less than the thickness of the conductive nonwoven fabric 21 (more specifically, the thinner the thickness of the adhesive layer 22 is), the less likely the wrap portion L is to open even when bending at R30, and the conductive path in the longitudinal direction of the electric wire can be easily secured.

[0028] 6 is a graph showing the shielding performance of the shielded electric wire 1 according to the present embodiment and a shielded electric wire according to a reference example. Note that Fig. 6 shows the shielding performance at a bent portion of R30.

[0029] First, when a conductive nonwoven fabric is wrapped around an electric wire vertically, a certain level of shielding performance is obtained. In contrast, when a conductive nonwoven fabric tape with an adhesive layer formed on the entire surface is wrapped around the electric wire in a half-wrap, the shielding performance is inferior to that of the vertical wrapping because it is no longer possible to ensure a conductive path in the longitudinal direction.

[0030] Furthermore, the shielded wire 1 according to the present embodiment, in which the conductive nonwoven fabric tape 20 is wrapped in a half-wrap manner such that the adhesive layer 22 is formed in a portion of the shielded wire 1 and the adhesive layer 22 is positioned outside the wrap portion L, has better shielding performance than that described above. Similarly, when a conductive nonwoven fabric tape (conductive nonwoven fabric) without the adhesive layer 22 is wrapped in a half-wrap manner, the wrap portion does not clearly open when bent at R30, and the same level of shielding performance as that of the present embodiment is obtained.

[0031] In addition, at frequencies of 100 MHz or higher in Fig. 6, the shielding performance without the adhesive layer is inferior to that of this embodiment. This is because, even if the lapped portion of the tape without the adhesive layer is not clearly open, the absence of the adhesive layer 22 causes the conductive nonwoven fabric to float somewhat more when bent. In addition, when the conductive nonwoven fabric tape without the adhesive layer is half-wrapped, the lapped portion opens if it is left in this state for a long time, and there is a concern that the shielding performance will be significantly reduced.

[0032] Next, examples and comparative examples will be described. In the examples and comparative examples, a conductive nonwoven tape was spirally wound around a plurality of diameter electric wires (conductor cross-sectional area of ​​10 sq. to 150 sq. and outer diameter of 5.6 mm to 22.0 mm) at the winding pitch shown in the examples and comparative examples. The width t of the wound conductive nonwoven tape and the width w of the adhesive layer were as shown in each example and comparative example.

[0033] Fig. 7 is a diagram showing details of the conductive nonwoven fabric tape used in the examples and comparative examples. The other configurations of the conductive nonwoven fabric tape used were as shown in Fig. 7. That is, the conductive nonwoven fabric of the conductive nonwoven fabric tape had a basis weight of 85 g / m 2 More than 180g / m 2The conductive nonwoven fabric used had a thickness of 0.25 mm to 0.55 mm, and the metal type constituting the plating portion was copper or a two-layer structure with copper as the inner layer and nickel as the outer layer. The surface resistance of this conductive nonwoven fabric was 2.0 mΩ / □ to 50 mΩ / □. The adhesive layer had an adhesive strength to stainless steel of 2.0 [N / 19 mm] to 14 [N / 19 mm], and a thickness of 0.02 mm to 0.08 mm. Various conductive nonwoven fabric tapes were used in the examples and comparative examples within the above numerical ranges, but the experimental results were not affected by any of them, and the results were as shown in Figures 8 to 10. The adhesive layer had an adhesive strength of 0.6 [N / 19 mm] to the coating of the electric wire used in the experiment.

[0034] The shielded electric wires according to the examples and comparative examples were arranged in a vehicle or the like, and a bending test was performed in which the shielded electric wires were bent to R30 many times as an alternative to a state in which the shielded electric wires were maintained in an R30 bent state for a long period of time. In the bending test, a straight shielded electric wire was bent 90 degrees using a mandrel of R30, and then returned to the original straight state, and the reciprocating bending was performed 50,000 times at a speed of 60 rpm.

[0035] Then, for the examples and comparative examples, the peeling of the conductive nonwoven fabric tape after the bending test and the shielding performance of the shielded electric wire after the bending test were compared with those of the vertically attached shielded electric wire.

[0036] 8 to 10 are diagrams showing examples and comparative examples. First, as shown in FIG. 8, the width t of the conductive nonwoven fabric tape was set to 20 mm in all of Examples 1 to 6 and Comparative Examples 1 to 3. The width w of the adhesive layer was set to 2 mm in Example 1, 4 mm in Example 2, 5 mm in Example 3, 7 mm in Example 4, 9 mm in Example 5, and 10 mm in Example 6. The width w of the adhesive layer was set to 1 mm in Comparative Example 1, 1.5 mm in Comparative Example 2, and 12 mm in Comparative Example 3. The adhesive layer was provided from the end of the conductive nonwoven fabric. The winding pitch of the conductive nonwoven fabric tape in the shielded electric wires of Examples 1 to 6 and Comparative Examples 1 to 3 was set to t / 2 (=10 mm).

[0037] In Examples 1 to 6, the conductive nonwoven fabric tape did not peel off after bending at R30 (50,000 bendings) for all wire diameters, and the shielding performance exceeded that of the longitudinally attached tape.

[0038] On the other hand, in Comparative Example 1 and Comparative Example 2, since the width w of the adhesive layer was small, it became difficult to maintain the state in which the conductive nonwoven fabric tape was wrapped around the electric wire, and the conductive nonwoven fabric tape peeled off. As a result, the shielding performance was also inferior to that of the vertical application. In Comparative Example 3, since the width w of the adhesive layer was secured widely, the conductive nonwoven fabric tape did not peel off, but since the width w of the adhesive layer was too large, the adhesive layer was interposed in the wrap portion, and the shielding performance was inferior to that of the vertical application.

[0039] Therefore, from Examples 1 to 6 and Comparative Examples 1 and 2, it was found that for a conductive nonwoven fabric tape having an adhesive layer (same thickness as the conductive nonwoven fabric) with an adhesive strength of 0.6 [N / 19 mm], if the thickness is 2 mm or more, i.e., t / 10 or more, the conductive nonwoven fabric tape does not peel off and the shielding performance exceeds that of a vertically attached tape. Also, from Examples 1 to 6 and Comparative Example 3, it was found that when the adhesive layer is interposed between the conductive nonwoven fabrics in the case of half-lap winding, a conductive path along the longitudinal direction of the electric wire cannot be secured and the shielding performance falls short of that of a vertically attached tape.

[0040] Next, as shown in Fig. 9, the width t of the conductive nonwoven fabric tape was all 20 mm, and the width w of the adhesive layer was all 5 mm in Examples 3 and 7 and Comparative Examples 4 and 5. The winding pitch of the conductive nonwoven fabric tape was t / 3 (≒6.67 mm) in Example 7, t / 2 (=10 mm) in Example 3, t / 4 (=5 mm) in Comparative Example 4, and t / 1.5 (≒13.3 mm) in Comparative Example 5. In the Examples and Comparative Examples shown in Fig. 9, the adhesive layer was also provided from the end of the conductive nonwoven fabric.

[0041] In the above-described Examples 3 and 7, the conductive nonwoven fabric tape did not peel off after bending at R30 (50,000 bendings) for all wire diameters, and the shielding performance also exceeded that of the longitudinally attached tape.

[0042] On the other hand, in Comparative Example 4, although the shielding performance was better than that of the vertically attached cable, the winding pitch was too small, so bending R30 itself was difficult. In Comparative Example 5, the winding pitch was too large, so peeling (opening) of the conductive nonwoven fabric tape occurred. As a result, the shielding performance was worse than that of the vertically attached cable.

[0043] Therefore, it was found from Examples 3 and 7 and Comparative Example 4 that when the winding pitch is t / 4, bending to R30 is difficult, but when it is at least t / 3 or more, bending to R30 is not difficult. Also, from Examples 3 and 7 and Comparative Example 5, it was found that when the winding pitch is t / 1.5, the conductive nonwoven fabric tape peels off when bending to R30, but when the winding pitch is t / 2 or less, peeling of the conductive nonwoven fabric tape is prevented, and a conductive path along the longitudinal direction of the electric wire is secured, resulting in shielding performance that exceeds that of longitudinal attachment.

[0044] Next, as shown in Fig. 10, in Example 6 and Comparative Examples 6 to 8, the width t of the conductive nonwoven fabric tape was all 20 mm, and the width w of the adhesive layer was all 10 mm. The winding pitch of the conductive nonwoven fabric tape was t / 2 (=10 mm) in Example 6, t / 4 (=5 mm) in Comparative Example 6, t / 3 (≒6.67 mm) in Comparative Example 7, and t / 1.5 (≒13.3 mm) in Comparative Example 8. In the examples and comparative examples shown in Fig. 10, the adhesive layer was also provided from the end of the conductive nonwoven fabric.

[0045] As described above with reference to FIG. 8, in Example 6, the conductive nonwoven fabric tape did not peel off after bending at R30 (50,000 bendings) for all wire diameters, and the shielding performance also exceeded that of the vertically attached tape.

[0046] On the other hand, in Comparative Example 6, the winding pitch was too small, so bending R30 itself was difficult. In addition, in Comparative Example 6, the width w of the adhesive layer was too large, so the adhesive layer was interposed within the lapped portion, resulting in a lower shielding performance than that of the longitudinally attached cable.

[0047] In addition, in Comparative Example 7, the winding pitch was appropriate and peeling of the conductive nonwoven tape was prevented, but the width w of the adhesive layer was too large, resulting in the adhesive layer being interposed within the wrap portion, resulting in lower shielding performance than that of the vertically attached tape.

[0048] In addition, in the case of Comparative Example 8, although no adhesive layer was interposed within the wrap portion, the winding pitch was too large, as in Comparative Example 5, so peeling (opening) of the conductive nonwoven tape occurred, and the shielding performance was lower than that of the vertically attached case.

[0049] Therefore, from Example 6 and Comparative Examples 6 to 8, it was found that bending is difficult when the winding pitch is t / 4, and bending at R30 is not difficult when the winding pitch is at least t / 3 or more. Also, from Comparative Example 7, it was found that even if the winding pitch is t / 3, if an adhesive layer is interposed in the lapped portion, the shielding performance is reduced. Furthermore, from Example 6 and Comparative Examples 7 and 8, it was found that when the winding pitch is t / 1.5, the conductive nonwoven tape peels off when bending at R30, but when the winding pitch is t / 2 or less, peeling of the conductive nonwoven tape is prevented. In particular, it was found that in Example 6, where no adhesive layer is interposed in the lapped portion, a conductive path along the longitudinal direction of the electric wire is secured, and the shielding performance exceeds that of the longitudinal lapped portion.

[0050] In this way, according to the shielded wire 1 of this embodiment, the adhesive layer 22 is located outside the wrap portion L, so that the conductive nonwoven fabrics 21 overlap each other in the wrap portion L, and the conduction path CP of the conductive nonwoven fabric 21 functioning as a shielding member can be set in the longitudinal direction of the wire 10. This makes it possible to suppress a decrease in the shielding effect even if the conductive nonwoven fabric tape 20 is wound spirally.

[0051] In addition, the winding pitch is t / 3 or more and t / 2 or less, the width w of the adhesive layer is t / 10 or more, and the adhesive strength is 0.6 [N / 19 mm] or more. Furthermore, the thickness AT of the adhesive layer 22 is set to the thickness of the conductive nonwoven fabric 21 or less, so that the conductive nonwoven fabric tape 20 is less likely to slip when bending at R30, and the lap portion L opens, which reduces the shielding effect. In more detail, the width w of the adhesive layer is t / 10 and the adhesive strength is 0.6 [N / 19 mm] or more, so that the conductive nonwoven fabric tape 20 is less likely to slip. In addition, the winding pitch is t / 3 or more, so there is no hindrance to bending, and the lap portion L is small because it is t / 2 or less, so that the covering portion 12 is prevented from being exposed when bending. Moreover, the thickness AT of the adhesive layer 22 is set to the thickness of the conductive nonwoven fabric 21 or less, so that the conductive nonwoven fabric 21 is less likely to move, and it is easy to ensure contact between the conductive nonwoven fabrics.

[0052] As a result, the shielded wire 1 according to this embodiment can suppress the decrease in the shielding effect. The thickness AT of the adhesive layer 22 is set to 0.01 mm or more in consideration of the difficulty in manufacturing.

[0053] In addition, according to the conductive nonwoven fabric tape 20 of this embodiment, since the adhesive layer 22 is formed on one side in the width direction, when the conductive nonwoven fabric tape 20 is wrapped around the electric wire 10 with a spiral wrap portion L, for example, by half wrapping, the adhesive layer 22 is located outside the wrap portion L and the conductive nonwoven fabrics 21 overlap each other at the wrap portion L. Therefore, the conductive nonwoven fabric 21 that functions as a shielding member can have a conduction path in the longitudinal direction of the electric wire. In addition, the adhesive layer 22 has an adhesive strength of 2.0 [N / 19 mm] or more in the adhesive strength measurement method specified by JISC2107. Therefore, the adhesive layer 22 exhibits an adhesive strength of 0.6 [N / 19 mm] or more against PVC, PP, PE, silicone, polyurethane, nylon, and the like. Furthermore, because the width w≧t / 10 of the adhesive layer and the thickness AT of the adhesive layer 22 are equal to or less than the thickness of the conductive nonwoven fabric 21, the conductive nonwoven fabric tape 20 is less likely to shift when bending R30 of the electric wire 10 having the coating 12 made of a material such as PVC, and the opening of the lap portion L, which would otherwise cause a decrease in the shielding effect, is suppressed. Therefore, a conductive nonwoven fabric tape that can suppress a decrease in the shielding effect can be provided.

[0054] The present invention has been described above based on an embodiment, but the present invention is not limited to the above embodiment, and modifications may be made without departing from the spirit of the present invention, and if possible, known or well-known technologies may be combined.

[0055] For example, in FIG. 2 and the examples, the adhesive layer 22 is formed from the end 21c of the conductive nonwoven fabric 21, but it is not limited to being formed from the end 21c, and it may be formed slightly inward. [Explanation of symbols]

[0056] 1: Shielded wire 10: Electric wire 12: Covering part 20: Conductive non-woven tape 21: Conductive nonwoven fabric 22: Adhesive layer AT: Adhesive layer thickness L: Wrap section t: Width of conductive nonwoven tape w: width of adhesive layer

Claims

1. A shielded electric wire in which a conductive nonwoven fabric tape having a conductive nonwoven fabric and an adhesive layer formed on one surface of the conductive nonwoven fabric is spirally wound around an electric wire, When a width of the conductive nonwoven fabric tape is t, the conductive nonwoven fabric tape is wound spirally around the electric wire with a winding pitch of t / 3 to t / 2 so that the one surface faces the electric wire, and has a lap portion which is a portion in the width direction of the conductive nonwoven fabric tape and where the conductive nonwoven fabrics overlap each other on the one surface, The adhesive layer is located outside the wrap portion, has an adhesive strength to the electric wire of 0.6 [N / 19 mm] or more, has a width w of the adhesive layer that is formed at t / 10 or more and a winding pitch or less, and has a thickness of 0.01 mm or more and a thickness of the conductive nonwoven fabric or less. Shielded electric wire characterized by:

2. A conductive nonwoven fabric tape having a conductive nonwoven fabric, which is a nonwoven fabric having electrical conductivity, and an adhesive layer formed on one surface of the conductive nonwoven fabric, The adhesive layer has an adhesive strength of 2.0 [N / 19 mm] or more, and when the overall width of the conductive nonwoven fabric tape is t, the width w of the adhesive layer is t / 10 or more and t / 2 or less, the adhesive layer is formed on one side in the width direction, and the thickness is 0.01 mm or more and less than the thickness of the conductive nonwoven fabric. A conductive nonwoven tape characterized by:

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