Conductive yarn and fabric with elastic wiring

Abstract

To provide a conductive thread from which a flexible wiring excellent in flexibility can be formed.SOLUTION: A conductive thread 10 in one aspect of the present invention comprises a core thread 1 containing a sacrificial material 1a removable by dissolution, and a sheath thread 2 containing a conductive wire material 2a, spirally wound around the core thread 1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a conductive yarn and a fabric with stretch wires. [Background technology]

[0002] There is known a strain sensor that detects strain from a change in resistance of a resistor in response to expansion and contraction. This strain sensor is used by attaching it to, for example, a bending or moving part of a robot, clothing, etc. This strain sensor is configured to be able to detect expansion and contraction strain by expanding and contracting the resistor in response to the expansion and contraction of the object to which it is attached.

[0003] The strain sensor is electrically connected to a wiring and outputs a detection signal through the wiring. Therefore, it is desirable that the wiring connected to the strain sensor has sufficient elasticity to follow the expansion and contraction of the object to which it is attached. As the wiring connected to the strain sensor, an elastic wiring has been proposed that includes an elastic core material and a conductive wire material wound around the core material (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 130477 [Patent Document 2] Special Publication No. 2016-500869 Summary of the Invention [Problem to be solved by the invention]

[0005] The elastic wire described in Patent Document 1 has an elastic core material, and therefore the conductive wire material can expand and contract in accordance with the expansion and contraction of the core material. However, this elastic wire material can only expand and contract the conductive wire material within the range in which the core material expands and contracts, and it is difficult to sufficiently increase the elasticity of the conductive wire material.

[0006] Patent Document 2 describes a device in which a stretchable coil that is meandering in a wavy shape and is used as an NFC antenna or the like is arranged in a ring shape on a flexible substrate. This coil is made of a conductive material that is two-dimensionally curved in a meandering, zigzag, grooved, ripple, or other shape, and the direction in which it stretches is likely to be limited. Therefore, this coil may have difficulty in expanding and contracting in accordance with the expansion and contraction of the flexible substrate.

[0007] The present invention has been made based on the above circumstances, and an object of the present invention is to provide a conductive yarn that can be formed into a stretchable wiring having excellent stretchability. [Means for solving the problem]

[0008] A conductive yarn according to one embodiment of the present invention comprises a core yarn including a sacrificial material that can be removed by dissolving, and a sheath yarn including a conductive wire wound in a spiral shape around the core yarn.

[0009] The sacrificial material may be water soluble.

[0010] The main component of the sacrificial material may be polyvinyl alcohol or polyethylene glycol.

[0011] The conductive wire may include organic fibers and a metal layer covering the organic fibers.

[0012] The organic fiber may be at least one selected from the group consisting of para-aramid fibers, wholly aromatic polyester fibers, and polybenzobisoxazole fibers.

[0013] The conductive wire may be a metal wire.

[0014] The conductive wire may be a tape having a metal deposition layer.

[0015] The conductive wire may have an insulating coating on its outermost surface.

[0016] The core yarn or the sheath yarn may further include a stopper yarn that keeps the length of the conductive wire below its elongation limit.

[0017] The stopper thread is preferably included in the sheath thread, and the number of turns of the stopper thread per unit length is preferably smaller than that of the conductive wire.

[0018] The stopper thread is preferably included in the core thread, and the elongation modulus of the stopper thread is preferably smaller than the elongation modulus of the conductive wire.

[0019] The stopper thread preferably contains at least one fiber selected from the group consisting of polyester fibers, polyamide fibers, polyurethane fibers, and silicone rubber.

[0020] A fabric with elastic wiring according to another aspect of the present invention comprises an elastic wiring including a conductive wire and a fabric, the conductive wire being spiral-shaped and arranged on the fabric so as to be kept below its elongation limit.

[0021] The conductive wire is attached to the fabric at a plurality of attachment points, and the fabric preferably maintains the length between adjacent attachment points of the conductive wire below its elongation limit.

[0022] In the present invention, the term "main component" refers to the component with the largest content in terms of mass, for example, the component with a content of 50 mass% or more. The term "elongation modulus" refers to a value determined in accordance with the elongation modulus A method of JIS L1013:2010. The term "elongation limit" refers to the maximum length that can be stretched. Effect of the Invention

[0023] In one embodiment of the present invention, the conductive yarn is arranged on a stretchable member such as a fabric or a rubber sheet with the sheath yarn wound around the core yarn in a spiral shape. The conductive yarn is used as a stretchable wiring by dissolving and removing the sacrificial material after being arranged on the stretchable member. Since the sacrificial material is present when the conductive yarn is arranged on the stretchable member, it is easy to maintain the conductive wire in a desired spiral shape when arranged on the stretchable member. Furthermore, since the sacrificial material is removed from the conductive yarn when it is used as a stretchable wiring, the stretching of the conductive wire is less likely to be hindered by the core yarn. Therefore, the conductive yarn can be formed into a stretchable wiring with excellent stretchability. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic side view showing a conductive yarn according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the conductive wire used in the conductive yarn of FIG. 1 in a direction perpendicular to the axis of the conductive wire. [Diagram 3] FIG. 3 is a schematic cross-sectional view of a conductive wire in a direction perpendicular to its axis, the conductive wire being different from the conductive wire in FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view of a conductive wire in a direction perpendicular to its axis according to a different embodiment from the conductive wires in FIGS. 2 and 3. In FIG. [Diagram 5] FIG. 5 is a schematic cross-sectional view of a conductive wire in a direction perpendicular to its axis, according to a different embodiment from the conductive wires in FIGS. [Figure 6] FIG. 6 is a schematic side view showing an expandable wiring formed using the conductive yarn of FIG. [Figure 7] FIG. 7 is a schematic cross-sectional view showing a fabric with stretchable wires formed using the conductive yarn of FIG. [Figure 8] FIG. 8 is a schematic cross-sectional view showing a sewing process for producing the fabric with the stretchable wiring of FIG. [Figure 9] FIG. 9 is a schematic cross-sectional view showing a bonding step for producing the fabric with the stretchable wiring of FIG. [Figure 10]FIG. 10 is a schematic plan view showing a fabric with stretchable wires according to an embodiment different from the fabric with stretchable wires in FIG. [Figure 11] FIG. 11 is a schematic side view showing a conductive yarn according to an embodiment different from the conductive yarn of FIG. [Figure 12] FIG. 12 is a schematic side view showing a stretchable wiring formed using the conductive yarn of FIG. [Figure 13] FIG. 13 is a schematic side view showing a conductive yarn according to an embodiment different from the conductive yarns shown in FIGS. 1 and 11. In FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

[0026] [First embodiment] <Conductive thread> The conductive yarn 10 in Fig. 1 includes a core yarn 1 including a sacrificial material 1a that can be removed by dissolving, and a sheath yarn 2 including a conductive wire 2a that is spirally wound around the core yarn 1. The conductive yarn 10 is used as an expandable wiring in a state in which the sacrificial material 1a has been removed by dissolving. More specifically, the conductive yarn 10 is arranged on an expandable member such as a fabric or a rubber sheet, and the sacrificial material 1a is removed after the conductive yarn 10 is arranged on the expandable member, thereby forming an expandable wiring that can expand and contract following the expandable member.

[0027] (core thread) The core thread 1 controls the helical pitch of the conductive wire 2a when the conductive thread 10 is placed on the elastic member (when forming a wiring pattern). That is, if the helical conductive wire 2a is sewn to the elastic member alone, the conductive wire 2a is stretched when sewn. If the conductive wire 2a is sewn in a stretched state, the conductive wire 2a will have a smaller extension width and its elasticity will decrease. In contrast, by winding the conductive wire 2a around the core thread 1, the conductive wire 2a is prevented from being stretched when sewn, and the extension width of the conductive wire 2a when used (when used as an elastic wiring) can be increased. The "helical pitch" refers to the pitch of a unit loop (one turn) in the central axis direction of the spiral.

[0028] In this embodiment, the core yarn 1 is made of a sacrificial material 1a. The core yarn 1 is removed at the time of use by dissolving the sacrificial material 1a. The sacrificial material 1a may be completely removed, or a portion of it may remain. The sacrificial material 1a is removed by dissolving, forming a space inside the spiral of the conductive wire 2a. This configuration increases the elasticity of the conductive wire 2a and makes it easier to bend the conductive wire 2a in a desired direction.

[0029] The method of dissolving the sacrificial material 1a is not particularly limited. The sacrificial material 1a may be configured to be dissolved by, for example, a chemical treatment such as an acid treatment or an alkali treatment, a heat treatment, an electrolytic treatment, or the like. However, it is preferable that the sacrificial material 1a dissolves in water. In other words, it is preferable that the sacrificial material 1a is water-soluble. As described above, the sacrificial material 1a is usually removed after being placed on the elastic member. Since the sacrificial material 1a is water-soluble, it is difficult to deteriorate other members such as the elastic member when removing the sacrificial material 1a.

[0030] The sacrificial material 1a is, for example, thread-like. When the sacrificial material 1a is thread-like (i.e., when the sacrificial material 1a is a sacrificial thread), the core thread 1 is formed by twisting, preferably plying and twisting, a plurality of sacrificial materials 1a. The number of sacrificial materials 1a used in the core thread 1 is not particularly limited, but can be, for example, 1 to 16. The average diameter of the core thread 1 can be, for example, 200 μm to 1000 μm. If the average diameter of the core thread 1 is less than the lower limit, the diameter of the spiral loop of the conductive wire 2a becomes small, and the conductive wire 2a may not be sufficiently stretchable after dissolution. Conversely, if the average diameter of the core thread 1 exceeds the upper limit, it may be difficult to sew the conductive thread 10. The "average diameter of the core thread" means the average value of the maximum diameters in any five cross sections perpendicular to the axis of the core thread.

[0031] When the sacrificial material 1a is water-soluble, examples of the main component of the sacrificial material 1a include polyvinyl alcohol, polyethylene glycol, water-soluble polyester, water-soluble polyamide, water-soluble ethylene-vinyl alcohol copolymer, etc. Among them, the main component of the sacrificial material 1a is preferably polyvinyl alcohol or polyethylene glycol, which is easy to dissolve.

[0032] (sheath thread) The sheath yarn 2 is wound around the core yarn 1 in a single layer in the S or Z direction. In this embodiment, the sheath yarn 2 is made of a conductive wire 2a. In other words, the conductive yarn 10 does not have any sheath yarn 2 other than the conductive wire 2a. The conductive yarn 10 is a single covering yarn in which the conductive wire 2a is wound spirally around the core yarn 1.

[0033] [Conductive wire] The conductive wire 2a is in close contact with the circumferential surface of the core thread 1. This configuration makes it easy to sew the conductive thread 10. In addition, this configuration makes it difficult for the conductive wire 2a to be stretched when placed on the elastic member. The spiral pitch of the conductive wire 2a can be determined according to the required elasticity. The average diameter of the conductive wire 2a is not particularly limited, but can be equal to or smaller than the average diameter of the core thread 1 from the viewpoint of ease of sewing, etc. The cross-sectional shape perpendicular to the axis of the conductive wire 2a is not particularly limited, and examples thereof include a circle, an ellipse, a triangle, a rectangle, and a polygon having pentagons or more. The conductive wire 2a may have a hollow portion inside. The conductive wire 2a may be a single wire, or a twisted wire in which a plurality of single wires are twisted together.

[0034] The lower limit of the average outer diameter R of the spiral loop of the conductive wire 2a is preferably 500 μm, more preferably 700 μm. On the other hand, the upper limit of the average outer diameter R is preferably 1200 μm, more preferably 1000 μm. If the average outer diameter R is less than the lower limit, it may be difficult to sufficiently increase the elasticity of the conductive wire 2a. On the other hand, if the average outer diameter R exceeds the upper limit, the arrangement space of the expandable wiring formed from the conductive thread 10 becomes large, and it may be difficult to arrange multiple expandable wirings at a narrow pitch. The "average outer diameter of the spiral loop of the conductive wire" can be calculated by adding the average diameter of the core thread and the value obtained by multiplying the average diameter of the conductive wire by two. In addition, the "average diameter of the conductive wire" means the average value of the maximum diameter in any five cross sections perpendicular to the axis of the conductive wire.

[0035] A specific configuration of the conductive wire 2a will be described with reference to FIG. 2. The conductive wire 2a has organic fibers 11a and a metal layer 12a that coats the organic fibers 11a. The conductive wire 2a has the organic fibers 11a and the metal layer 12a, which improves flexibility and reduces weight. The conductive wire 2a is formed by coating the metal layer 12a around the organic fibers 11a. The conductive wire 2a is, for example, a plated thread in which the metal layer 12a is plated around the organic fibers 11a.

[0036] Examples of the organic fiber 11a include polyester fibers such as polyethylene terephthalate fibers, polytrimethylene terephthalate fibers, polybutylene terephthalate fibers, and wholly aromatic polyester fibers; polyamide fibers such as nylon 6 fibers and nylon 66 fibers; polyolefin fibers such as polyethylene fibers and polypropylene fibers; aramid fibers; polybenzobisoxazole fibers; polyacrylonitrile fibers; and polyvinyl alcohol fibers. Among these, at least one selected from the group consisting of aramid fibers, wholly aromatic polyester fibers, and polybenzobisoxazole fibers, which have excellent tensile strength, is preferred. As the aramid fiber, para-aramid fibers are preferred.

[0037] Examples of the main component of the metal layer 12a include gold or silver, which have low electrical resistance, and copper, which is relatively inexpensive.

[0038] 2, the conductive wire 2a has an insulating coating 13a on the outermost surface. This configuration can easily prevent breakage or damage to the metal layer 12a. In addition, the conductive wire 2a can be prevented from contacting with the metal layers 12a due to expansion and contraction, thereby preventing changes in electrical resistance due to expansion and contraction.

[0039] The conductive wire 2a is a three-layer structure in which a metal layer 12a is laminated on the outer periphery of an organic fiber 11a, and an insulating coating 13a is laminated on the outer periphery of the metal layer 12a. Examples of the main components of the insulating coating 13a include synthetic resins and elastomers. Examples of the synthetic resins include polyesters such as polyethylene terephthalate, and polyamides such as nylon 6 and nylon 66. Examples of the elastomers include natural rubber, butyl rubber, isoprene rubber, ethylene-propylene rubber, butadiene rubber, urethane rubber, styrene-butadiene rubber, silicone rubber, and acrylonitrile butadiene rubber.

[0040] [Modification of Conductive Wire] Next, modified examples of the conductive wire 2a will be described with reference to Fig. 3 to Fig. 5. The conductive wire 2b in Fig. 3, the conductive wire 2c in Fig. 4, and the conductive wire 2d in Fig. 5 can be used instead of the conductive wire 2a in Fig. 2.

[0041] The conductive wire 2b in Fig. 3 is a metal wire. By using the conductive wire 2b as a metal wire, the cross-sectional area of ​​the conductor can be increased, and as a result, the electrical resistance can be reduced.

[0042] The conductive wire 2b has a linear conductor 11b. The conductor 11b is made of metal fibers. Examples of the main components of the metal fibers include iron, copper, and alloys thereof. Examples of iron alloys include stainless steel. The conductor 11b may be a single wire, or a twisted wire in which a plurality of single wires are twisted together. The conductor 11b may also include a plated wire in which a metal layer is plated around the metal fibers. Examples of the plated wire include tin-plated soft copper wire.

[0043] The conductive wire 2b has an insulating coating 13b on the outermost surface. The conductive wire 2b is a multi-layer body in which the insulating coating 13b is laminated on the outer periphery of the conductor 11b. The conductive wire 2b may be a two-layer body in which the insulating coating 13b is laminated on the outer periphery of the metal fiber, or a three-layer body in which the insulating coating 13b is laminated on the outer periphery of the plated wire. The main components of the insulating coating 13b include synthetic resin and elastomer, similar to the main components of the insulating coating 13a in FIG. 2.

[0044] The conductive wire 2c in FIG. 4 is a tape having a metal deposition layer 12c. Specifically, the conductive wire 2c has a sheet-shaped base layer 11c and a metal deposition layer 12c laminated on the base layer 11c by deposition. Since the conductive wire 2c is a tape having the metal deposition layer 12c, the manufacturing cost can be reduced. Also, since the conductive wire 2c is a tape having the metal deposition layer 12c, it is provided, for example, in a substantially rectangular cross section with a small thickness relative to its width. This allows the conductive wire 2c to be made thinner.

[0045] Examples of the main components of the base layer 11c include synthetic resins such as polyethylene terephthalate, polyimide, and fluororesin, ceramics, etc. Examples of the main components of the metal deposition layer 12c include copper, aluminum, etc.

[0046] The conductive wire 2c has an insulating coating 13c on the outermost surface. The conductive wire 2c is a three-layer structure including a base layer 11c, a metal deposition layer 12c, and an insulating coating 13c. The main components of the insulating coating 13c include synthetic resin and elastomer, which are the same as the main components of the insulating coating 13a in FIG.

[0047] The conductive wire 2d in FIG. 5 has organic fibers 11a and a metal layer 12a that covers the organic fibers 11a. The conductive wire 2d in FIG. 5 has the same configuration as the conductive wire 2a in FIG. 2, except that it does not have an insulating coating on the outermost surface. Since the conductive wire 2d does not have an insulating coating on the outermost surface, it can improve the slipperiness against the fabric 31, etc. in a state in which the sacrificial material 1a has been removed (a state in which the conductive wire 2d is formed into the expandable wiring 20 described later). Since the conductive wire 2d is spiral, it is relatively difficult for the parts of the conductive wire 2d to come into contact with each other when the conductive wire 2d expands or contracts. Therefore, even if the conductive wire 2d does not have an insulating coating, it is easy to suppress the change in electrical resistance caused by expansion and contraction.

[0048] As a modification of the conductive wire 2a, it is possible to employ a configuration in which the conductive wire 2b in FIG. 3 or the conductive wire 2c in FIG. 4 does not have the insulating coatings 13b, 13c.

[0049] <Advantages> The conductive yarn 10 is arranged on a stretchable member such as a fabric or a rubber sheet in a state where the sheath yarn 2 is wound around the core yarn 1 in a spiral shape. The conductive yarn 10 is used as a stretchable wiring by dissolving and removing the sacrificial material 1a after being arranged on the stretchable member. Since the sacrificial material 1a is present when the conductive yarn 10 is arranged on the stretchable member, it is easy to maintain the conductive wire 2a in a desired spiral shape when arranged on the stretchable member. Furthermore, since the sacrificial material 1a is removed from the conductive yarn 10 when it is used as a stretchable wiring, the stretching of the conductive wire 2a is less likely to be hindered by the core yarn 1. Therefore, the conductive yarn 10 can be formed into a stretchable wiring with excellent stretchability.

[0050] <Stretchable wiring> The stretchable wire 20 in Fig. 6 is formed using the conductive thread 10 in Fig. 1. The stretchable wire 20 in Fig. 6 includes a spiral conductive wire 2a. More specifically, the stretchable wire 20 is made of a spiral conductive wire 2a. The stretchable wire 20 is obtained by dissolving the sacrificial material 1a of the conductive thread 10 in Fig. 1.

[0051] <Advantages> The stretchable wire 20 is disposed on the stretchable member with the helical pitch and the like appropriately controlled. Therefore, the stretchable wire 20 has excellent stretchability. In addition, since the conductive wire 2a of the stretchable wire 20 is helical, the stretchable wire 20 is easily bent in a desired direction. Since the stretchable wire 20 is disposed on the stretchable member with the conductive wire 2a wound helically around the core yarn 1, for example, by adjusting the diameter of the core yarn 1, the shape of the helical loop, the helical pitch, and the like can be easily and appropriately controlled.

[0052] <Fabric with elastic wiring> The fabric 30 with the stretchable wire in FIG. 7 includes the stretchable wire 20 in FIG. 6 and a fabric 31. The fabric 30 with the stretchable wire also includes a protective sheet 32 ​​having stretchability. The stretchable wire 20 is made of a spiral conductive wire 2a. The conductive wire 2a is sandwiched and held between the fabric 31 and the protective sheet 32. The fabric 31 has stretchability. Examples of the fabric 31 include nonwoven fabric, woven fabric, knitted fabric, etc. Examples of the protective sheet 32 ​​include a rubber sheet, a synthetic resin sheet, etc.

[0053] The conductive wire 2a is arranged in the fabric 31 so as to be kept below its elongation limit. In other words, the conductive wire 2a is arranged in the fabric 31 so as not to be stretched to its elongation limit. With this configuration, breakage or damage to the conductive wire 2a can be easily prevented.

[0054] The conductive wire 2a may be fixed to the fabric 31 and kept below the elongation limit, or may be fixed to the protective sheet 32 ​​and kept below the elongation limit. The conductive wire 2a may also be positioned on the fabric 31 or protective sheet 32 ​​in a scattered manner along the longitudinal direction, and held such that the spaces between the positioned portions are kept below the elongation limit. When the conductive wire 2a is positioned in a scattered manner along the longitudinal direction, the conductive wire 2a has a plurality of fixing points at which it is fixed to the fabric 31 or protective sheet 32.

[0055] In FIG. 7, the conductive wire 2a is attached to the fabric by a plurality of attachment parts 33. Each of the attachment parts 33 constitutes the aforementioned fixed point. The fabric 31 keeps the length between the adjacent attachment parts 33 of the conductive wire 2a below the stretch limit. With this configuration, the fabric 30 with the stretchable wire can easily make the conductive wire 2a follow the stretching and bending of the fabric 31, while easily preventing breakage or damage to the conductive wire 2a.

[0056] 8 and 9, an example of a manufacturing method of the fabric with stretchable wiring 30 will be described. The manufacturing method of the fabric with stretchable wiring includes a step of sewing the conductive thread 10 to the fabric 31 (sewing step), a step of attaching the protective sheet 32 ​​to the fabric 31 so as to sandwich the conductive thread 10 after the sewing step (attaching step), and a step of removing the sacrificial material 1a of the conductive thread 10 after the attaching step (removing step).

[0057] 8, in the sewing process, for example, the conductive thread 10 is used as a lower thread and sewn to a fabric 31. In addition, in the sewing process, a water-soluble thread is used as an upper thread .

[0058] 9, in the attaching step, the protective sheet 32 ​​is attached to the fabric 31 from the side where the conductive thread 10 is arranged. The method for attaching the protective sheet 32 ​​is not particularly limited, but examples thereof include thermocompression bonding.

[0059] In the removing step, the sacrificial material 1a and the upper thread 34 are removed by dissolving while the protective sheet 32 ​​is attached to the fabric 31. As a result, the fabric 30 with stretchable wiring shown in FIG. 7 is obtained. As shown in FIG. 7, the fabric 30 with stretchable wiring has the conductive wires 2a attached to the fabric 31 in a scattered manner at a predetermined interval. The specific attachment structure of the conductive wires 2a is not particularly limited. For example, the conductive wires 2a may be attached to the fabric 31 by sewing, or the conductive wires 2a may be attached to the fabric 31 by intertwining their spiral shape with the fabric 31. In the fabric 30 with stretchable wiring, for example, the conductive threads 10 are sewn to penetrate the fabric 31 in the thickness direction in the sewing step, so that the conductive wires 2a can be easily attached to the fabric 31.

[0060] <Advantages> The fabric 30 with the elastic wires has excellent elasticity and flexibility of the elastic wires 20.

[0061] [Second embodiment] <Fabric with elastic wiring> With reference to FIG. 10, a fabric 40 with stretchable wiring according to an embodiment different from that of FIG. 7 will be described. In FIG. 10, the fabric 41 is configured as a fabric for a glove. More specifically, the fabric 41 is configured as a back fabric covering the back of the hand and the back parts of the five fingers. A glove including the fabric 40 with stretchable wiring is configured as a data glove capable of detecting the movement of the fingers of the wearer's hand, for example. The fabric 40 with stretchable wiring includes a stretchable wiring 20 including a conductive wire 2a, and a fabric 41. The fabric 40 with stretchable wiring also includes a protective sheet 42 having stretchability. The stretchable wiring 20 of FIG. 6 is used as the stretchable wiring 20. In addition, in the fabric 40 with stretchable wiring, the conductive wire 2a is configured as a wire connected to the strain sensor X.

[0062] The conductive wire 2a is spirally shaped. The conductive wire 2a is arranged on the fabric 41 so as to be kept below its elongation limit. More specifically, the conductive wire 2a is fixed to the protective sheet 42 so as to be kept below its elongation limit.

[0063] An example of a manufacturing method of the fabric with the stretchable wires 40 will be described. The manufacturing method of the fabric with the stretchable wires includes a step of fixing the conductive threads 10 to a processing film (not shown) made of a synthetic resin such as polyethylene terephthalate (fixing step), a step of attaching a protective sheet 42 to the processing film so as to sandwich the conductive threads 10 after the fixing step (first attachment step), a step of removing the sacrificial material 1a of the conductive threads 10 and the processing film after the first attachment step (removal step), and a step of attaching the fabric 41 to the protective sheet 42 so as to sandwich the stretchable wires 20 formed by removing the sacrificial material 1a after the removal step (second attachment step).

[0064] In the fixing step, for example, the conductive thread 10 is placed on the surface of the process film, and then the conductive thread 10 is sewn to the process film using a water-soluble thread. In the removing step, the sacrificial material 1a and the water-soluble thread are removed by dissolving while the protective sheet 42 is attached to the process film. This removes the process film from the protective sheet 42. The manufacturing method for the stretchable wired fabric may include a step (punching step) of punching out the portion of the conductive thread 10 that is not used as wiring (the portion where the strain sensor X is arranged) after the conductive thread 10 is fixed to the process film in the fixing step.

[0065] <Advantages> The fabric 40 with stretchable wires has excellent stretchability and flexibility of the stretchable wires 20, similar to the fabric 30 with stretchable wires in FIG.

[0066] [Third embodiment] <Conductive thread> The conductive yarn 50 in FIG. 11 includes a core yarn 51 including a sacrificial material 51a that can be removed by dissolving, and a sheath yarn 2 including a conductive wire 2a that is spirally wound around the core yarn 51. The conductive yarn 50 further includes a stopper yarn 51b that keeps the conductive wire 2a at a length equal to or less than the stretch limit. The conductive yarn 50 is used as an expandable wiring in a state in which the sacrificial material 51a is removed by dissolving. The stopper yarn 51b is included in the core yarn 51. The conductive yarn 50 can have the same configuration as the conductive yarn 10 in FIG. 1, except that the core yarn 51 includes the stopper yarn 51b. Therefore, only the core yarn 51 will be described below.

[0067] (core thread) As described above, the core yarn 51 includes the sacrificial material 51a and the stopper yarn 51b. The specific configuration of the sacrificial material 51a may be the same as that of the sacrificial material 1a in Fig. 1. The core yarn 51 is formed by twisting, preferably plying and twisting, one or more sacrificial materials 51a and one or more stopper yarns 51b.

[0068] The material of the stopper thread 51b is not particularly limited as long as it can prevent the conductive wire 2a from breaking or stretching. However, it is preferable that the stopper thread 51b contains at least one type selected from the group consisting of polyester fiber, polyamide fiber, polyurethane fiber, and silicone rubber. By containing the fiber or rubber, the stopper thread 51b can easily prevent the conductive wire 2a from breaking or stretching while preventing the elasticity of the conductive wire 2a from being hindered.

[0069] The maximum extension length of the stopper thread 51b per unit length of the conductive thread 50 is smaller than the maximum extension length of the conductive wire 2a. With this configuration, the stopper thread 51b keeps the conductive wire 2a at a length equal to or less than the extension limit.

[0070] The stopper thread 51b is preferably elastic. The elongation modulus of the stopper thread 51b is preferably smaller than the elongation modulus of the conductive wire 2a. With this configuration, the stopper thread 51b can more reliably prevent the conductive wire 2a from breaking or stretching completely. In addition, the effect of the stopper thread 51b on the elongation and stretching of the conductive wire 2a can be reduced.

[0071] <Advantages> The conductive thread 50 can be formed into an expandable wiring having excellent elasticity, similar to the conductive thread 10 in Fig. 1. Moreover, the conductive thread 50 includes a stopper thread 51b that keeps the conductive wire 2a at a length equal to or less than the extension limit, so that the conductive wire 2a can be easily and reliably prevented from breaking or stretching.

[0072] <Stretchable wiring> The stretchable wire 60 in FIG. 12 is formed using the conductive thread 50 in FIG. 11. The stretchable wire 60 in FIG. 12 includes a spiral conductive wire 2a. The stretchable wire 60 is obtained by dissolving the sacrificial material 51a of the conductive thread 50 in FIG. 11. The stretchable wire 60 has the same configuration as the stretchable wire 20 in FIG. 6, except that it includes a stopper thread 51b. As shown in FIG. 12, the stopper thread 51b is disposed inside the spiral of the conductive wire 2a along the stretching direction of the conductive wire 2a.

[0073] <Advantages> The expandable wire 60 has excellent expandability and is easily bent in a desired direction, similar to the expandable wire 20 in Fig. 6. In addition, since the expandable wire 60 includes the stopper thread 51b, it is possible to easily and reliably prevent the conductive wire 2a from breaking or stretching.

[0074] [Fourth embodiment] <Conductive thread> The conductive yarn 70 in FIG. 13 includes a core yarn 1 including a sacrificial material 1a that can be removed by dissolving, and a sheath yarn 72 including a conductive wire 72a wound in a spiral shape around the core yarn 1. The conductive yarn 70 further includes a stopper yarn 72b that keeps the conductive wire 72a at a length equal to or less than the stretch limit. The conductive yarn 70 is used as an expandable wiring in a state in which the sacrificial material 1a has been removed by dissolving. The stopper yarn 72b is included in the sheath yarn 72. The conductive yarn 70 can be configured in the same manner as the conductive yarn 10 in FIG. 1, except that the sheath yarn 72 includes the stopper yarn 72b. Therefore, only the sheath yarn 72 will be described below.

[0075] (sheath thread) As described above, the sheath yarn 72 includes the conductive wire 72a and the stopper yarn 72b. The specific configuration of the conductive wire 72a may be the same as that of the conductive wire 2a in Fig. 1. The specific configuration of the stopper yarn 72b may be the same as that of the stopper yarn 51b in Fig. 11.

[0076] The sheath yarn 72 is preferably configured by winding a stopper yarn 72b spirally around the core yarn 1, and further winding a conductive wire 72a spirally from the outside of the stopper yarn 72b. With this configuration, it is easy to make the maximum extension length of the stopper yarn 72b per unit length of the conductive yarn 70 smaller than the maximum extension length of the conductive wire 72a.

[0077] The winding direction of the conductive wire 72a and the stopper thread 72b is not particularly limited. When the conductive thread 70 is a double covering thread in which the stopper thread 72b is wound around the core thread 1 in the S direction or Z direction and the conductive wire 72a is further wound in the opposite direction to the stopper thread 72b, it is easy to prevent the conductive wire 72a from being stretched when the conductive thread 70 is placed on a stretchable member such as a fabric.

[0078] Although the number of turns of the stopper thread 72b per unit length of the conductive thread 70 is not particularly limited, it is preferable that the number of turns is smaller than the number of turns of the conductive wire 72a. With this configuration, the stopper thread 51b can easily prevent the conductive wire 2a from breaking or stretching.

[0079] <Advantages> The conductive thread 70 can be formed into an expandable wiring having excellent elasticity, similar to the conductive thread 10 in Fig. 1. Moreover, the conductive thread 70 includes the stopper thread 72b that keeps the conductive wire 72a at a length equal to or less than the extension limit, so that the conductive wire 72a can be easily and reliably prevented from breaking or stretching out.

[0080] <Stretchable wiring> The stretchable wire obtained by removing the sacrificial material 1a of the conductive thread 70 has the stopper thread 72b disposed inside the spiral of the conductive wire 72a along the stretch direction of the conductive wire 72a. The stretchable wire has excellent stretchability and is easily bent in a desired direction, similar to the stretchable wire 20 of Fig. 6. In addition, since the stretchable wire includes the stopper thread 72b, breakage or stretching of the conductive wire 72a can be easily and reliably prevented.

[0081] [Other embodiments] The above-described embodiments do not limit the configuration of the present invention. Therefore, the above-described embodiments may include omissions, substitutions, or additions of components of each part of the embodiments based on the description in this specification and common general technical knowledge, and all of these should be interpreted as falling within the scope of the present invention.

[0082] The configurations described in the first to fourth embodiments can be combined in any manner. For example, the conductive thread 50 in Fig. 11 and the conductive thread 70 in Fig. 13 can be used in the fabric 30 with stretchable wires in Fig. 7 or the fabric 40 with stretchable wires in Fig. 10 instead of the conductive thread 10 in Fig. 1.

[0083] The stopper thread may be conductive. According to this configuration, by measuring the electrical resistance of the stopper thread, breakage of the stopper thread can be detected. As a result, it is easy to grasp the presence or absence of deterioration of the conductive wire.

[0084] The specific configuration of the conductive wire is not limited to the configuration described in the above embodiment. For example, the conductive wire may be configured to include carbon nanotubes, may be configured to include conductive polymer fibers, or may be configured by kneading metal powder, conductive polymer, etc. into organic fibers. In addition, the fibers included in the conductive wire may be filaments (long fibers) or staples (short fibers).

[0085] The procedure for disposing the conductive thread on the elastic member such as a fabric is not particularly limited. For example, the conductive thread may be directly sewn onto the elastic member using an embroidery machine or the like. In addition, when sewing the conductive thread as a lower thread and another thread as an upper thread, it is also possible to use a thread that is not removed by dissolving as the other thread. Furthermore, in order to prevent the elastic member from stretching when the conductive thread is sewn, it is also possible to laminate a non-stretchable sheet onto the elastic member and sew the conductive thread to the elastic member and the sheet at the same time. Even in this case, for example, by using a water-soluble sheet as the non-stretchable sheet or a water-soluble thread as the upper thread, the non-stretchable sheet can be easily separated from the elastic member after sewing.

[0086] The expandable wiring does not necessarily have to be fixed to an expandable member such as a fabric or a protective sheet. For example, a tubular passage for arranging the expandable wiring in the expandable member may be formed, and the expandable wiring may be arranged in this passage. [Industrial Applicability]

[0087] As described above, the conductive yarn according to one aspect of the present invention is suitable for forming an expandable wiring having excellent elasticity. [Explanation of symbols]

[0088] 1, 51 core thread 1a, 51a Sacrificial materials 2, 72 sheath thread 2a, 2b, 2c, 2d, 72a conductive wire 10, 50, 70 Conductive thread 11a Organic Fibers 11b Conductor 11c Base layer 12a metal layer 12c metal evaporated layer 13a, 13b, 13c Insulation coating 20, 60 Stretchable wiring 30, 40 Fabric with stretch wiring 31, 41 Fabric 32, 42 Protective sheet 33 Mounting part 34 Upper thread 51b, 72b stopper thread R is the average outer diameter of the spiral loop of the conductive wire X Distortion Sensor

Claims

1. A conductive yarn, a core yarn including a sacrificial material that can be removed by dissolving; a sheath yarn wound spirally around the core yarn; Equipped with The sheath yarn includes a conductive wire and a stopper yarn, A conductive yarn in which the maximum extension length of the stopper yarn per unit length of the conductive yarn is smaller than the maximum extension length of the conductive wire.

2. The conductive yarn of claim 1 , wherein the sacrificial material is water soluble.

3. The conductive thread according to claim 2 , wherein the main component of the sacrificial material is polyvinyl alcohol or polyethylene glycol.

4. The conductive yarn according to claim 1 , 2 or 3 , wherein the conductive wire comprises organic fibers and a metal layer covering the organic fibers.

5. The conductive yarn according to claim 4 , wherein the organic fiber is at least one selected from the group consisting of para-aramid fiber, wholly aromatic polyester fiber, and polybenzobisoxazole fiber.

6. The conductive yarn according to claim 1 , 2 or 3 , wherein the conductive wire is a metal wire.

7. The conductive yarn according to claim 1, claim 2 or claim 3, wherein the conductive wire is a tape having a metal vapor deposition layer.

8. The conductive yarn according to claim 1 , wherein the conductive wire has an insulating coating on its outermost surface.

9. The conductive thread according to claim 1 , wherein the number of turns of the stopper thread per unit length is smaller than that of the conductive wire.

10. The conductive yarn according to any one of claims 1 to 9, wherein the stopper yarn comprises at least one type selected from the group consisting of polyester fiber, polyamide fiber, polyurethane fiber, and silicone rubber.

11. An elastic wiring including a conductive wire and a stopper thread; Fabric and Equipped with The conductive wire and the stopper thread are spirally shaped, The maximum extension length of the stopper thread per unit length of the expandable wire is smaller than the maximum extension length of the conductive wire, The conductive wire is disposed on the fabric so as to be kept below an elongation limit.

12. The conductive wire is attached to the fabric at a plurality of attachment portions, The fabric with stretchable wires according to claim 11, wherein the fabric keeps the lengths between the adjacent attachment portions of the conductive wires below their respective stretch limits.

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