Sheet-shaped conductive member and sheet-shaped heater

Abstract

Provided is a sheet-shaped conductive member (100) including a sheet-shaped structure (2) formed by a plurality of conductive linear bodies (21) arranged at intervals, wherein, when the sheet-shaped conductive member (100) is viewed from above, the conductive linear bodies (21) have a wave shape in which a second wave having an amplitude and a wavelength shorter than a first wave is provided along the first wave.

Description

TECHNICAL FIELD

[0001] The present application relates to a sheet-like conductive member and a sheet-like heater. BACKGROUND

[0002] A sheet-like conductive member having a plurality of conductive linear bodies arranged at intervals in a sheet-like structure (hereinafter also referred to as "conductive sheet") has the possibility of being used as a member of various articles such as a heating element for a heating device, a heat-generating textile material, a protective film (shatterproof film) for a display, and the like.

[0003] As a sheet for a heating element, for example, Patent Literature 1 describes a conductive sheet having a plurality of conductive linear bodies arranged at intervals in a sheet-like structure extending in one direction. In this conductive sheet, the conductive linear bodies have a first portion having a wave shape with a wavelength λ1 and an amplitude A1, and a second portion having a wave shape with a wavelength λ2 and an amplitude A2 different from at least one of the wavelength λ1 and the amplitude A1 of the first portion.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: International Publication No. 2018 / 097323 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] According to the conductive sheet described in Patent Literature 1, by providing the conductive linear bodies with a wave shape, the elongation of the conductive sheet can be improved, that is, when the conductive sheet is elongated, breakage of the conductive linear bodies can be prevented. However, depending on the use of the conductive sheet, further improvement in elongation is required.

[0009] An object of the present application is to provide a sheet-like conductive member and a sheet-like heater having high elongation.

[0010] METHOD FOR SOLVING PROBLEMS

[0011] A sheet-like conductive member of one embodiment of the present application includes a plurality of conductive linear bodies arranged at intervals in a sheet-like structure, and in plan view of the sheet-like conductive member, the conductive linear bodies have a wave shape, and the wave shape has a second wave with an amplitude and a wavelength shorter than a first wave.

[0012] In the sheet-like conductive member of one embodiment of the present application, when the amplitude of the first wave is A1 and the wavelength of the first wave is λ1, it is preferable to satisfy the following mathematical expression (F1).

[0013] 1 / 20 < A1 / λ1 < 1...(F1)

[0014] In the sheet-shaped conductive member of one embodiment of the present application, when the amplitude of the first wave is A1 and the amplitude of the second wave is A2, it is preferable that the following mathematical expression (F2) be satisfied.

[0015] 1 / 10 < A2 / A1 < 3 / 5...(F2)

[0016] In the sheet-shaped conductive member of one embodiment of the present application, when the wavelength of the first wave is λ1 and the wavelength of the second wave is λ2, the following mathematical expression (F3) is satisfied.

[0017] 1 / 21 < λ2 / λ1 < 1 / 3...(F3)

[0018] In the sheet-shaped conductive member of one embodiment of the present application, the conductive linear member is preferably at least one selected from the group consisting of a linear member including a metal wire, a linear member including a carbon nanotube, and a linear member in which a wire is covered with a conductive coating.

[0019] In the sheet-shaped conductive member of one embodiment of the present application, it is preferable to further include an elastic substrate that supports the sheet-shaped structure.

[0020] The sheet-shaped conductive member of one embodiment of the present application is preferably used as a heating body.

[0021] The sheet-shaped heater of one embodiment of the present application includes the sheet-shaped conductive member of one embodiment of the present application.

[0022] According to the present application, a sheet-shaped conductive member and a sheet-shaped heater with high elongation can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic view of a sheet-shaped conductive member of the first embodiment of the present application.

[0024] Figure 2 is a cross-sectional view of II-II cross section of Figure 1 .

[0025] Figure 3 is a schematic view of one embodiment of a conductive linear member of the first embodiment of the present application.

[0026] Figure 4 is a schematic view of another embodiment of a conductive linear member of the first embodiment of the present application.

[0027] Figure 5 is a schematic view of a sheet-shaped conductive member of the second embodiment of the present application.

[0028] Symbol Explanation

[0029] 1···Substrate

[0030] 2···Imitation sheet-like structure

[0031] 21··· Conductive linear body

[0032] 3··· Resin layer

[0033] 100, 100A...sheet-shaped conductive components Detailed Implementation

[0034] [First Implementation Method]

[0035] The present invention will now be described with reference to the accompanying drawings, using examples of embodiments. However, the present invention is not limited to the embodiments described herein. It should be noted that some parts in the accompanying drawings are enlarged or reduced for ease of explanation.

[0036] (Sheet-shaped conductive component)

[0037] like Figure 1 and Figure 2 As shown, the sheet-like conductive member 100 of this embodiment includes: a substrate 1, a sheet-like structure 2, and a resin layer 3. Specifically, in the sheet-like conductive member 100, a resin layer 3 is stacked on the substrate 1, and a sheet-like structure 2 is stacked on the resin layer 3. In this embodiment, when the sheet-like conductive member 100 is viewed from above, the conductive line 21 in the sheet-like structure 2 is characterized by having a waveform shape as described below.

[0038] (Similar to a sheet-like structure)

[0039] The sheet-like structure 2 has a structure in which multiple conductive linear bodies 21 are arranged at intervals. That is, the sheet-like structure 2 is a structure in which multiple conductive linear bodies 21 are arranged at intervals and form a planar or curved surface. When the sheet-like conductive member 100 is viewed from above, the conductive linear bodies 21 have a wave-like shape. The sheet-like structure 2 is formed in such a way that multiple conductive linear bodies 21 are arranged in a direction orthogonal to the axis of the conductive linear bodies 21.

[0040] The waveform shape of the conductive linear body 21 is, for example, Figure 3As illustrated, the second wave W2 having an amplitude and a wavelength shorter than the first wave W1 is arranged along the first wave W1. Note that, when a mathematical expression of the first wave W1 is f(x) and a mathematical expression of the second wave W2 is g(x), a mathematical expression of the wave shape is f(x) + g(x). In this specification, the wave shape represented by the mathematical expression f(x) + g(x) is also referred to as a "synthetic-type complex wave shape" as the case can be.

[0041] The wave shape of the conductive linear bodies 21 can be, for example, Figure 4 As illustrated, the second wave W2 having an amplitude and a wavelength shorter than the first wave W1 is arranged along the first wave W1 in a direction perpendicular to the first wave W1. In this specification, the wave shape that becomes this shape is also referred to as a "fractal-type complex wave shape" as the case can be.

[0042] As the wave shape of the first wave W1 and the second wave W2, for example, a sine wave, a semi-circular wave, a rectangular wave, a triangular wave, and a sawtooth wave, or the like can be given. Among them, from the viewpoint of the elongation of the sheet-shaped conductive member 100, a sine wave or a semi-circular wave is preferable. Further, from the viewpoint that the risk of overlapping or contact of the conductive linear bodies 21 with each other can be suppressed when the conductive linear bodies 21 are processed into a wave shape, a semi-circular wave is more preferable. In addition, the wave shape of the first wave W1 can be the same as or different from that of the second wave W2. Note that the semi-circular wave is a wave shape in which a semi-circle that protrudes in the direction of the wave peak (up) and a semi-circle that protrudes in the direction of the wave valley (down) appear alternately.

[0043] If the conductive linear bodies 21 are in the wave shape as described above, when the sheet-shaped conductive member 100 is elongated in the axial direction of the conductive linear bodies 21 (the direction of travel of the first wave W1), the cutting of the conductive linear bodies 21 can be suppressed. That is, compared to the case of a straight line, the portion of the conductive linear bodies 21 in the wave shape makes the path length longer. Further, compared to the case where the wave shape is a single wave, the path length of the wave shape as described above is longer. Therefore, the sheet-shaped conductive member 100 has high elongation when elongated in the axial direction of the conductive linear bodies 21 (the direction of travel of the first wave W1). Note that, even if the sheet-shaped conductive member 100 is elongated in a direction orthogonal to the axial direction of the conductive linear bodies 21 (hereinafter also referred to as an "orthogonal direction"), the cutting of the conductive linear bodies 21 does not occur. Therefore, the sheet-shaped conductive member 100 has sufficient elongation.

[0044] The elongation rate when the sheet-shaped conductive member 100 is elongated in the direction of travel of the first wave W1 of the conductive linear bodies 21 is preferably 50% or more, more preferably 70% or more, and further preferably 100% or more. When the elongation rate is 50% or more, a curved surface or the like of an adherend can also be accommodated.

[0045] Further, the elongation of the sheet-shaped conductive member 100 in a direction orthogonal to the advancing direction of the first wave W1 of the conductive linear member 21 is preferably 50% or more, more preferably 70% or more, and further preferably 100% or more. When the elongation is 50% or more, it is possible to conform to a curved surface or the like of an adherend.

[0046] Here, when the length of the sheet-shaped conductive member 100 is set to A, and the length of the sheet-shaped conductive member 100 when the sheet-shaped conductive member 100 is elongated in a given direction and the conductive linear member 21 is cut is set to B, the elongation of the sheet-shaped conductive member 100 in the present application is expressed by the following formula. Note that whether the conductive linear member 21 is cut or not can be determined by measuring the resistance value of the conductive linear member 21 when the sheet-shaped conductive member 100 is elongated.

[0047] Elongation (%) = {(B-A) / A} x 100

[0048] In the present embodiment, when the amplitude of the first wave W1 is set to A1 [mm], and the wavelength of the first wave W1 is set to λ1 [mm], it is preferable to satisfy the following mathematical formula (F1).

[0049] 1 / 20 ≤ A1 / λ1 ≤ 1...(F1)

[0050] When the value of A1 / λ1 is within the above range, it is possible to further improve the elongation of the sheet-shaped conductive member 100, and it is possible to secure the interval between the adjacent conductive linear members 21, and it is possible to prevent the adjacent conductive linear members 21 from contacting each other. Further, from the above viewpoint, the value of A1 / λ1 is more preferably 7 / 20 or more and 3 / 5 or less.

[0051] The amplitude A1 of the first wave W1 is preferably 1 mm or more and 200 mm or less, and more preferably 2 mm or more and 50 mm or less. When the amplitude A1 of the first wave W1 is within the above range, it is possible to further improve the elongation of the sheet-shaped conductive member 100.

[0052] The wavelength λ1 of the first wave W1 is preferably 1 mm or more and 200 mm or less, and more preferably 2 mm or more and 100 mm or less. When the wavelength λ1 of the first wave W1 is within the above range, it is possible to further improve the elongation of the sheet-shaped conductive member 100.

[0053] In the present embodiment, when the amplitude of the first wave W1 is set to A1 [mm], and the amplitude of the second wave W2 is set to A2 [mm], it is preferable to satisfy the following mathematical formula (F2).

[0054] 1 / 10 ≤ A2 / A1 ≤ 3 / 5...(F2)

[0055] When the value of A2 / A1 is within the above range, the elongation of the sheet-shaped conductive member 100 can be further improved, and the interval between the adjacent conductive linear bodies 21 can be ensured, and the adjacent conductive linear bodies 21 can be prevented from contacting each other. Further, from the above viewpoint, the value of A2 / A1 is more preferably 1 / 5 or more and 2 / 5 or less.

[0056] In the present embodiment, when the wavelength of the first wave W1 is λ1 [mm], and the wavelength of the second wave W2 is λ2 [mm], it is preferable to satisfy the following mathematical expression (F3).

[0057] 1 / 21 ≤ λ2 / λ1 ≤ 1 / 3...(F3)

[0058] When the value of λ2 / λ1 is within the above range, the elongation of the sheet-shaped conductive member 100 can be further improved, and the interval between the adjacent conductive linear bodies 21 can be ensured, and the adjacent conductive linear bodies 21 can be prevented from contacting each other. Further, from the above viewpoint, the value of λ2 / λ1 is more preferably 1 / 15 or more and 1 / 5 or less.

[0059] The volume resistivity R of the conductive linear body 21 is preferably 1.0 x 10 -9 Ω·m or more and 1.0 x 10 -3 Ω·m or less, and more preferably 1.0 x 10 -8 Ω·m or more and 1.0 x 10 -4 Ω·m or less. When the volume resistivity R of the conductive linear body 21 is within the above range, the surface resistance of the sheet-shaped structure 2 can be easily reduced.

[0060] The volume resistivity R of the conductive linear body 21 is measured as follows. The end portion on one side of the conductive linear body 21 and the portion 40 mm from the end portion are coated with silver paste, and the resistance of the end portion and the portion 40 mm from the end portion is measured, and the resistance value of the conductive linear body 21 is calculated. Then, the cross-sectional area (unit: m 2 ) of the conductive linear body 21 is multiplied by the above resistance value, and the obtained value is divided by the above measured length (0.04 m), and the volume resistivity of the conductive linear body 21 is calculated.

[0061] The shape of the cross section of the conductive linear body 21 is not particularly limited, and can be a polygonal shape, a flat shape, an elliptical shape, or a circular shape, but from the viewpoint of matching with the resin layer 3 and the like, an elliptical shape or a circular shape is preferable.

[0062] In the case where the cross section of the conductive linear body 21 is circular, the thickness (diameter) D (refer to FIG. 2) of the conductive linear body 21 is preferably 0.1 mm or more and 1.0 mm or less. Figure 2The diameter D of the conductive wire 21 is preferably 5 μm or more and 3 mm or less. From the viewpoint of suppressing the rise of sheet resistance and improving the heating efficiency and resistance to insulation failure when using the sheet conductive member 100 as a heating element, the diameter D of the conductive wire 21 is more preferably 8 μm or more and 60 μm or less, and even more preferably 12 μm or more and 40 μm or less.

[0063] When the cross-section of the conductive linear body 21 is elliptical, it is preferable that the major axis is within the same range as the diameter D mentioned above.

[0064] Regarding the diameter D of the conductive linear body 21, the conductive linear body 21 of the sheet-like structure 2 was observed using a digital microscope, and the diameter of the conductive linear body 21 was measured at 5 randomly selected locations, and the average value was taken.

[0065] The spacing L of the conductive linear body 21 (refer to) Figure 2 Preferably, the diameter is 1 mm or more and 400 mm or less, more preferably 2 mm or more and 200 mm or less, and even more preferably 3 mm or more and 100 mm or less.

[0066] When the spacing between the conductive linear bodies 21 is within the above range, since the conductive linear bodies are densely packed together to a certain extent, it is possible to improve the function of the sheet conductive member 100, such as making the temperature rise distribution more uniform when the sheet conductive member 100 is used as a heating element.

[0067] Regarding the spacing L of the conductive linear bodies 21, the conductive linear bodies 21 of the sheet-like structure 2 are observed with the naked eye or using a digital microscope, and the spacing between two adjacent conductive linear bodies 21 is measured.

[0068] It should be noted that the interval between two adjacent conductive wires 21 refers to the length along the direction in which the conductive wires 21 are arranged, and is the length between the opposite portions of the two conductive wires 21 (see reference). Figure 2 When the conductive linear bodies 21 are arranged at unequal intervals, the interval L is the average value of the intervals between all adjacent conductive linear bodies 21.

[0069] The conductive wire 21 is not particularly limited and can be a wire containing metal wires (hereinafter also referred to as "metal wire wire"). Metal wires have high thermal conductivity, high electrical conductivity, high processability, and versatility. Therefore, when using a metal wire wire as the conductive wire 21, it is possible to reduce the resistance value of the sheet-like structure 2 while improving light transmittance. In addition, when using the sheet-like conductive member 100 (sheet-like structure 2) as the heating element, rapid heating is easily achieved. Furthermore, as described above, it is easy to obtain a wire with a small diameter.

[0070] Note that as the conductive linear member 21, in addition to the metal wire linear member, a linear member including a carbon nanotube, and a linear member in which a wire is covered with a conductive material can be cited.

[0071] The metal wire linear member can be a linear member formed of one metal wire, or a linear member twisted from a plurality of metal wires.

[0072] As the metal wire, a metal wire including copper, aluminum, tungsten, iron, molybdenum, nickel, titanium, silver, gold, or the like, or a metal wire including an alloy containing two or more kinds of metals (for example, stainless steel, carbon steel, brass, phosphor bronze, zirconium copper alloy, beryllium copper, iron-nickel, nickel-chromium alloy, nickel-titanium, constantan, hastelloy, and tungsten-rhenium) can be cited. In addition, the metal wire can be plated with tin, zinc, silver, nickel, chromium, nickel-chromium alloy, or solder, or the like, or can be covered with a carbon material or a polymer as described later. From the viewpoint of producing a conductive linear member 21 having a low volume resistivity, a wire including one or more kinds of metals selected from tungsten and molybdenum and alloys containing them is particularly preferable.

[0073] As the metal wire, a metal wire covered with a carbon material can be cited. When the metal wire is covered with a carbon material, the metallic luster is reduced, and the presence of the metal wire is less likely to be seen. In addition, when the metal wire is covered with a carbon material, metal corrosion can also be suppressed.

[0074] As the carbon material covering the metal wire, amorphous carbon (for example, carbon black, activated carbon, hard carbon, soft carbon, mesoporous carbon, and carbon fiber), graphite, fullerene, graphene, and carbon nanotube, or the like can be cited.

[0075] The linear body including carbon nanotubes can be obtained, for example, by pulling out carbon nanotubes in a sheet shape from the end portion of a carbon nanotube forest (a growth body in which a plurality of carbon nanotubes are grown on a substrate in a manner of being oriented in a direction perpendicular to the substrate, and is sometimes referred to as "array"), bundling the pulled-out carbon nanotube sheet, and twisting the bundle of carbon nanotubes. In such a manufacturing method, a tape-shaped carbon nanotube linear body can be obtained without twisting at the time of twisting, and a thread-shaped linear body can be obtained with twisting. The tape-shaped carbon nanotube linear body is a linear body that does not have a structure in which carbon nanotubes are twisted. Furthermore, a carbon nanotube linear body can also be obtained by spinning or the like from a dispersion liquid of carbon nanotubes. The manufacturing of a carbon nanotube linear body based on spinning can be performed, for example, by the method disclosed in U.S. Patent Application Publication No. 2013 / 0251619 (Japanese Patent Application Publication No. 2012-126635). From the viewpoint of obtaining uniformity in the diameter of the carbon nanotube linear body, it is desirable to use a thread-shaped carbon nanotube linear body, and from the viewpoint of obtaining a carbon nanotube linear body with high purity, it is preferable to obtain a thread-shaped carbon nanotube linear body by twisting a carbon nanotube sheet. The carbon nanotube linear body can also be a linear body in which two or more carbon nanotube linear bodies are braided with each other. In addition, the carbon nanotube linear body can be a linear body in which carbon nanotubes are compounded with other conductive materials (hereinafter also referred to as "composite linear body").

[0076] As the composite linear body, for example, the following can be listed: (1) a composite linear body obtained by pulling out carbon nanotubes in a sheet shape from the end portion of a carbon nanotube forest, bundling the pulled-out carbon nanotube sheet, and twisting the bundle of carbon nanotubes, in which a metal element or a metal alloy is loaded on the surface of the forest, sheet, bundle, or twisted linear body of carbon nanotubes by evaporation, ion plating, sputtering, wet plating, or the like during the process; (2) a composite linear body obtained by twisting a bundle of carbon nanotubes together with a linear body of a metal element, a linear body of a metal alloy, or a composite linear body; (3) a composite linear body obtained by braiding a linear body of a metal element, a linear body of a metal alloy, or a composite linear body with a carbon nanotube linear body or a composite linear body; and the like. Note that, for the composite linear body of (2), the metal can be loaded on the carbon nanotubes in the same manner as the composite linear body of (1) at the time of twisting the bundle of carbon nanotubes. In addition, the composite linear body of (3) is a composite linear body at the time of braiding two linear bodies, but as long as it includes at least one linear body of a metal element, a linear body of a metal alloy, or a composite linear body, three or more carbon nanotube linear bodies, linear bodies of metal elements, linear bodies of metal alloys, or composite linear bodies can also be braided together.

[0077] As the metal of the composite linear body, metal elements such as gold, silver, copper, iron, aluminum, nickel, chromium, tin, and zinc, and alloys containing at least one of these metal elements (copper-nickel-phosphorus alloy, copper-iron-phosphorus-zinc alloy, and the like) can be given.

[0078] The conductive linear body 21 can be a linear body obtained by applying conductive coating to a filament. As the filament, a filament spun from a resin such as nylon or polyester, or the like can be given. As the conductive coating, a film of a metal, a conductive polymer, a carbon material, or the like can be given. The conductive coating can be formed by plating or vapor deposition, or the like. The linear body obtained by applying conductive coating to a filament can increase the conductivity of the linear body while maintaining the flexibility of the filament. That is, it is easy to cause the sheet-like structure 2 to have a reduced resistance.

[0079] (Base material)

[0080] As the base material 1, a synthetic resin film, paper, a metal foil, a nonwoven fabric, cloth, a glass film, or the like can be given. With this base material 1, the sheet-like structure 2 can be directly or indirectly supported. In addition, the base material 1 is preferably an elastic base material.

[0081] As the elastic base material, a synthetic resin film, a nonwoven fabric, cloth, or the like can be used. In addition, among these elastic base materials, a synthetic resin film or cloth is preferred, and a synthetic resin film is more preferred.

[0082] As the synthetic resin film, a polyethylene film, a polypropylene film, a polybutylene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polybutylene terephthalate film, a polyurethane film, an ethylene-vinyl acetate copolymer film, an ionomer resin film, an ethylene-(meth)acrylic acid copolymer film, an ethylene-(meth)acrylic ester copolymer film, a polystyrene film, a polycarbonate film, a polyimide film, or the like can be given. In addition, as the elastic base material, crosslinked films and laminated films thereof, or the like can be given.

[0083] In addition, as the paper, all-wood pulp paper, recycled paper, kraft paper, or the like can be given. As the nonwoven fabric, spun-bond nonwoven fabric, needle punch nonwoven fabric, melt-blown nonwoven fabric, spun-laced nonwoven fabric, or the like can be given. As the cloth, woven fabric, knitted fabric, or the like can be given. The nonwoven fabric and cloth as the elastic base material are not limited thereto.

[0084] (Resin layer)

[0085] The resin layer 3 is a layer containing a resin. By the resin layer 3, the sheet-like structure 2 can be directly or indirectly supported. In addition, the resin layer 3 is preferably a layer containing an adhesive. When the sheet-like structure 2 is formed on the resin layer 3, by the adhesive, the adhesion of the conductive linear body 21 to the resin layer 3 becomes easy. In addition, when the resin layer 3 is a layer containing an adhesive, the substrate 1 and the conductive linear body 21 can be easily adhered via the resin layer 3.

[0086] The resin layer 3 can be a layer formed of a dryable or curable resin. Thereby, the resin layer 3 can be given a hardness sufficient to protect the sheet-like structure 2, and the resin layer 3 also functions as a protective film. In addition, the resin layer 3 after curing or drying has impact resistance, and also can suppress deformation of the sheet-like structure 2 due to impact.

[0087] From the viewpoint that curing can be performed simply in a short time, the resin layer 3 is preferably energy ray-curable, such as ultraviolet rays, visible energy rays, infrared rays, electron beams, and the like. Note that "energy ray-curing" also includes thermal curing based on heating using energy rays.

[0088] The adhesive of the resin layer 3 can be exemplified by a thermally curable adhesive that is cured by heat, a so-called heat-seal type adhesive that is adhered by heat, an adhesive that exhibits adhesion by wetting, and the like. Among them, from the ease of use, the resin layer 3 is preferably energy ray-curable. As the energy ray-curable resin, a compound having at least one polymerizable double bond in the molecule can be cited, and an acrylate compound having a (meth)acryloyl group is preferable.

[0089] As the above-described acrylate compound, for example, a (meth)acrylate containing a chain aliphatic skeleton (trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxy penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate, etc.), a (meth)acrylate containing a cyclic aliphatic skeleton (dicyclopentyl di(meth)acrylate, and dicyclopentadiene di(meth)acrylate, etc.), a polyalkylene glycol (meth)acrylate (polyethylene glycol di(meth)acrylate, etc.), an oligoester (meth)acrylate, a urethane (meth)acrylate oligomer, an epoxy-modified (meth)acrylate, a polyether (meth)acrylate other than the above-described polyalkylene glycol (meth)acrylate, and an itaconic acid oligomer, etc. can be cited.

[0090] The weight average molecular weight (Mw) of the energy ray-curable resin is preferably 100 to 30,000, more preferably 300 to 10,000.

[0091] The energy ray-curable resin contained in the adhesive composition can be only one, or two or more, and the combination and ratio thereof can be arbitrarily selected. In addition, it can be combined with the thermoplastic resin described later, and the combination and ratio can be arbitrarily selected.

[0092] The resin layer 3 can also be an adhesive layer formed of an adhesive (pressure-sensitive adhesive). The adhesive of the adhesive layer is not particularly limited. As the adhesive, for example, an acrylic adhesive, a urethane adhesive, a rubber-based adhesive, a polyester-based adhesive, a silicone-based adhesive, and a polyvinyl ether-based adhesive can be listed. Among them, the adhesive is preferably at least one selected from the group consisting of an acrylic adhesive, a urethane adhesive, and a rubber-based adhesive, and more preferably an acrylic adhesive.

[0093] As the acrylic adhesive, for example, a polymer containing a structural unit derived from an alkyl (meth)acrylate having a linear or branched alkyl group (i.e., a polymer obtained by polymerizing at least an alkyl (meth)acrylate), and an acrylic polymer containing a structural unit derived from a (meth)acrylate having a cyclic structure (i.e., a polymer obtained by polymerizing at least a (meth)acrylate having a cyclic structure) can be listed. Here, "(meth)acrylate" is a term used to mean both "acrylate" and "methacrylate", and the same applies to other similar terms.

[0094] In the case where the acrylic polymer is a copolymer, the mode of copolymerization is not particularly limited. As the acrylic copolymer, it can be any of a block copolymer, a random copolymer, or a graft copolymer.

[0095] The acrylic copolymer can also be crosslinked by a crosslinking agent. As the crosslinking agent, for example, a well-known epoxy crosslinking agent, an isocyanate crosslinking agent, an aziridine crosslinking agent, a metal chelate crosslinking agent, and the like can be listed. In the case where the acrylic copolymer is crosslinked, as the functional group derived from the monomer component of the acrylic polymer, a hydroxyl group or a carboxyl group, which reacts with these crosslinking agents, can be introduced into the acrylic copolymer.

[0096] In the case where the resin layer 3 is formed of an adhesive, the resin layer 3 can contain the energy ray-curable resin described above in addition to the adhesive. In the case where an acrylic adhesive is used as the adhesive, as the energy ray-curable component, a compound having both a functional group that reacts with the functional group of the monomer component from the acrylic copolymer and an energy ray-polymerizable functional group in one molecule can be used. By the reaction of the functional group of the compound with the functional group of the monomer component from the acrylic copolymer, the side chain of the acrylic copolymer can be polymerized by irradiation of energy rays. In the case where the adhesive is not an acrylic adhesive, as the polymer component other than the acrylic polymer, a component having an energy ray-polymerizable side chain can be used as well.

[0097] As the thermosetting resin used for the resin layer 3, there is no particular limitation, and specific examples include epoxy resins, phenol resins, melamine resins, urea resins, polyester resins, urethane resins, acrylic resins, benzoxazine resins, phenoxy resins, amine-based compounds, and acid anhydride-based compounds. These can be used alone or in combination with two or more kinds. Among them, from the viewpoint of suitability for curing using an imidazole-based curing catalyst, it is preferable to use an epoxy resin, a phenol resin, a melamine resin, a urea resin, an amine-based compound, and an acid anhydride-based compound, and in particular, from the viewpoint of exhibiting excellent curing properties, it is preferable to use an epoxy resin, a phenol resin, a mixture thereof, or a mixture of an epoxy resin and at least one selected from a phenol resin, a melamine resin, a urea resin, an amine-based compound, and an acid anhydride-based compound. As the thermosetting resin used for the resin layer 3, there is no particular limitation, and specific examples include epoxy resins, phenol resins, melamine resins, urea resins, polyester resins, urethane resins, acrylic resins, benzoxazine resins, phenoxy resins, amine-based compounds, and acid anhydride-based compounds. These can be used alone or in combination with two or more kinds. Among them, from the viewpoint of suitability for curing using an imidazole-based curing catalyst, it is preferable to use an epoxy resin, a phenol resin, a melamine resin, a urea resin, an amine-based compound, and an acid anhydride-based compound, and in particular, from the viewpoint of exhibiting excellent curing properties, it is preferable to use an epoxy resin, a phenol resin, a mixture thereof, or a mixture of an epoxy resin and at least one selected from a phenol resin, a melamine resin, a urea resin, an amine-based compound, and an acid anhydride-based compound.

[0098] As the moisture-curable resin used for the resin layer 3, there is no particular limitation, and examples include urethane resins, which generate isocyanate groups by moisture, and modified silicone resins.

[0099] In the case where an energy ray-curable resin or a thermosetting resin is used, it is preferable to use a photopolymerization initiator or a thermal polymerization initiator, or the like. By using a photopolymerization initiator or a thermal polymerization initiator, or the like, a crosslinked structure can be formed, and the prosthesis-like structure 2 can be more firmly protected.

[0100] As the photopolymerization initiator, examples include benzophenone, phenylethanone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin benzoic acid methyl ester, benzoin dimethyl ether, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, 2-chloroanthraquinone, 2,4,6-trimethylbenzoyl diphenyl phosphine oxide, and bis(2,4,6-trimethylbenzoyl) phenyl phosphine oxide.

[0101] As the thermal polymerization initiator, the following can be given: hydrogen peroxide, peroxodisulfates (ammonium peroxodisulfate, sodium peroxodisulfate, potassium peroxodisulfate, etc.), azo compounds (2,2'-azobis(2-amidinopropane) dihydrochloride, 4,4'-azobis(4-cyanopentanoic acid), 2,2'-azobisisobutyronitrile, and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), etc.), and organic peroxides (benzoyl peroxide, lauroyl peroxide, peroxyacetic acid, peroxy succinic acid, di-t-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, etc.), and the like.

[0102] These polymerization initiators can be used alone or in combination of two or more.

[0103] In the case where these polymerization initiators are used to form a crosslinked structure, the amount thereof is preferably 0.1 parts by mass or more and 100 parts by mass or less, more preferably 1 part by mass or more and 100 parts by mass or less, and particularly preferably 1 part by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the energy ray-curable resin or the thermosetting resin.

[0104] The resin layer 3 can also not be curable, but can be a layer formed of, for example, a thermoplastic resin composition. Further, by containing a solvent in the thermoplastic resin composition, the thermoplastic resin layer can be softened. Thus, when the sheet-like structure 2 is formed on the resin layer 3, it becomes easy to adhere the electrically conductive linear body 21 to the resin layer 3. On the other hand, by volatilizing the solvent in the thermoplastic resin composition, the thermoplastic resin can be dried and solidified.

[0105] As the thermoplastic resin, the following can be given: polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polyurethane, polyether, polyethersulfone, polyimide, and acrylic resin, etc.

[0106] As the solvent, the following can be given: alcohol solvents, ketone solvents, ester solvents, ether solvents, hydrocarbon solvents, halogenated alkyl solvents, and water, etc.

[0107] The resin layer 3 can also contain an inorganic filler material. By containing an inorganic filler material, the hardness of the resin layer 3 after curing can be further improved. Also, the thermal conductivity of the resin layer 3 can be improved.

[0108] As the inorganic filler material, the following can be given, for example: inorganic powders (powders of, for example, silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride, etc.), beads obtained by spheroidizing inorganic powders, single crystal fibers, and glass fibers, etc. Among these, as the inorganic filler material, silica fillers and alumina fillers are preferable. The inorganic filler material can be used alone or in combination of two or more.

[0109] The resin layer 3 can further contain other components. As the other components, for example, known additives such as an organic solvent, a flame retardant, an adhesion enhancer, an ultraviolet absorber, an antioxidant, a preservative, a mildewcide, a plasticizer, an antifoaming agent, and a wetness adjuster can be exemplified.

[0110] The thickness of the resin layer 3 can be appropriately determined depending on the use of the sheet-shaped conductive member 100. For example, from the viewpoint of adhesion, the thickness of the resin layer 3 is preferably 3 μm or more and 150 μm or less, and more preferably 5 μm or more and 100 μm or less.

[0111] (Method for manufacturing sheet-shaped conductive member)

[0112] The method for manufacturing the sheet-shaped conductive member 100 of the present embodiment is not particularly limited, and for example, can be manufactured by the following procedures.

[0113] First, a composition for forming the resin layer 3 is applied to the base material 1 to form a coating film. Next, the coating film is dried to produce the resin layer 3. Next, the conductive linear body 21 is arranged and disposed on the resin layer 3 to form the pseudo-sheet-shaped structure 2. For example, in a state where the resin layer 3 with the base material 1 is disposed on the outer circumferential surface of a drum member, the conductive linear body 21 is continuously fed and wound in a spiral shape on the resin layer 3 while the drum member is rotated. At this time, the continuous feeding portion of the conductive linear body 21 is moved so as to make a small reciprocating motion repeatedly in a direction intersecting the axial direction (wave traveling direction) of the conductive linear body 21 while making a large reciprocating motion as a whole, whereby the conductive linear body 21 having a composite wave shape having a synthetic type in which the imaginary second wave W2 is provided along the imaginary first wave Wl can be formed. In addition, by appropriately selecting the rotation speed of the drum member, the continuous feeding speed of the conductive linear body, and the moving speed and moving distance of the continuous feeding portion, the first wave Wl and the second wave W2 of the conductive linear body can be made to have desired waveforms, amplitudes, and wavelengths, respectively. Then, the bundle of the conductive linear body 21 wound in a spiral shape is cut along the axial direction of the drum member. Thus, the pseudo-sheet-shaped structure 2 is formed and disposed on the resin layer 3. Then, the resin layer 3 with the base material 1 on which the pseudo-sheet-shaped structure 2 is formed is removed from the drum member, whereby the sheet-shaped conductive member 100 is obtained.

[0114] As another method of manufacturing the sheet-like conductive member 100, a conductive linear member 21 having a wave shape of the second wave W2 can be prepared in advance, and the conductive linear member 21 is arranged and disposed on the resin layer 3 formed on the base material 1 to form the pseudo sheet-like structure 2. In this case, for example, the resin layer 3 with the base material 1 is disposed on the outer circumferential surface of a drum member, and the conductive linear member 21 having a wave shape of the second wave W2 is wound on the resin layer 3 in a spiral shape while the drum member is rotated. At this time, the continuous feeding portion of the conductive linear member 21 is reciprocally moved in a direction parallel to the axis of the drum member, and thus the conductive linear member 21 having a wave shape of the second wave W2 along the first wave W1 can be obtained. Then, the bundle of the conductive linear member 21 wound in a spiral shape is cut in the axial direction of the drum member, and thus the sheet-like conductive member 100 can be obtained.

[0115] (EFFECTS OF THE FIRST EMBODIMENT)

[0116] According to the present embodiment, the following effects can be obtained.

[0117] (1) In the present embodiment, the wave shape of the conductive linear member 21 is a shape in which the second wave W2 having a shorter wavelength than the first wave W1 is provided along the first wave W1. Thus, the sheet-like conductive member 100 having higher elongation than the conventional member can be obtained.

[0118] (2) The sheet-like conductive member 100 of the present embodiment has high elongation, and thus can be suitably used as a heating body.

[0119] [SECOND EMBODIMENT]

[0120] Next, the second embodiment of the present application will be described based on the drawings.

[0121] Note that, in the present embodiment, the sheet-like conductive member 100A shown in FIG. 1 is described as one example of a sheet-like heater. Figure 5

[0122] The sheet-like conductive member 100A of the present embodiment has the pseudo sheet-like structure 2 having low surface resistance, and thus is suitably used as a sheet-like heater.

[0123] Note that, in the present embodiment, the same configuration as the first embodiment is employed except that the electrode 4 is mounted on the pseudo sheet-like structure 2, and thus the electrode 4 will be described, and the portions common to the previous description will be omitted.

[0124] ​The electrode 4 is used to supply current to the electrically conductive linear member 21. The electrode 4 can be formed using a known electrode material. As the electrode material, for example, an electrically conductive paste (silver paste, etc.), a metal foil (copper foil, etc.), and a metal wire, etc. can be listed. The electrode 4 is disposed in electrical connection with both end portions of the electrically conductive linear member 21.

[0125] As the metal of the metal foil or the metal wire, for example, copper, aluminum, tungsten, iron, molybdenum, nickel, titanium, silver, gold, etc. or an alloy containing two or more of these metals (for example, stainless steel, carbon steel, etc., brass, phosphor bronze, zirconium copper alloy, beryllium copper, iron-nickel, nickel-chromium alloy, nickel-titanium, constantan, hastelloy, and tungsten-rhenium, etc.) can be listed. In addition, the metal foil or the metal wire can be a material plated with tin, zinc, silver, nickel, chromium, nickel-chromium alloy, or solder, etc.

[0126] The ratio of the resistance value of the electrode 4 to the resistance value of the pseudo sheet-like structure 2 (resistance value of the electrode 4 / resistance value of the pseudo sheet-like structure 2) is preferably 0.0001 or more and 0.3 or less, and more preferably 0.0005 or more and 0.1 or less. The ratio of the resistance value of the electrode to the resistance value of the pseudo sheet-like structure 2 can be obtained by "resistance value of the electrode 4 / resistance value of the pseudo sheet-like structure 2". By being within this range, in the case where the sheet-like conductive member 100A is used as a heating body, abnormal heating of the electrode portion can be suppressed. In the case where the pseudo sheet-like structure 2 is used as a sheet-like heater, a sheet-like heater in which only the pseudo sheet-like structure 2 is heated and the heating efficiency is good can be obtained.

[0127] The resistance values of the electrode 4 and the pseudo sheet-like structure 2 can be measured using a multimeter. First, the resistance value of the electrode 4 is measured, and then the resistance value of the pseudo sheet-like structure 2 after the electrode 4 is attached is measured. Then, the resistance values of the electrode 4 and the pseudo sheet-like structure 2 are calculated by subtracting the measured value of the electrode 4 from the resistance value of the pseudo sheet-like structure 2 after the electrode 4 is attached.

[0128] The thickness of the electrode 4 is preferably 2 μm or more and 200 μm or less, more preferably 2 μm or more and 120 μm or less, and particularly preferably 10 μm or more and 100 μm or less. When the thickness of the electrode is within the above range, the electrical conductivity is high and the resistance is low, and the resistance value of the pseudo sheet-like structure can be suppressed to a low level. In addition, a sufficient strength can be obtained as the electrode.

[0129] (Action effects of the second embodiment)

[0130] According to the present embodiment, the same action effects as the action effects (1) and (2) of the above-described first embodiment can be obtained.

[0131] (Modifications of the embodiments)

[0132] The present application is not limited to the above-described embodiments, and modifications, improvements, and the like made within a range capable of achieving the object of the present application are included in the scope of the present application.

[0133] For example, in the above-described embodiments, the sheet-shaped conductive member 100 has the base material 1, but is not limited thereto. For example, the sheet-shaped conductive member 100 can not have the base material 1. In such a case, the sheet-shaped conductive member 100 can be used by being adhered to an adherend by the resin layer 3.

[0134] In the above-described embodiments, the sheet-shaped conductive member 100 has the resin layer 3, but is not limited thereto. For example, the sheet-shaped conductive member 100 can not have the resin layer 3. In such a case, the sheet-shaped conductive member 100 can be formed by using a knitted fabric as the base material 1 and knitting the conductive linear bodies 21 into the base material 1.

[0135] Example

[0136] Hereinafter, the present application will be described in more detail by citing examples. The present application is not limited to these examples.

[0137] [Examples 1 to 19]

[0138] An acrylic adhesive (manufactured by Lindal Corporation, trade name "PK") was applied to a polyurethane film having a thickness of 100 μm as a base material at a thickness of 20 μm to form a resin layer, and an adhesive sheet was produced.

[0139] A wire shooting device (manufactured by Lindal Corporation) was used to shoot metal wires (material: tungsten) on the adhesive sheet while moving a nozzle to arrange 30 metal wires, and a sheet-shaped conductive member was obtained. The cross section of the metal wire was circular, and the diameter thereof was 80 μm. In addition, a metal wire shaped into a second wave in advance was used.

[0140] The kind of the waveform shape of the metal wire (conductive linear body), the waveform of the first wave, the waveform of the second wave, the value of A1 / λ1, the value of A2 / A1, and the value of λ2 / λ1 in the obtained sheet-shaped conductive member are shown in Table 1. Note that the wavelength λ1 of the first wave was 4 mm, and the amplitude A1 of the first wave was 2 mm. In addition, the interval between the metal wires was 1 mm.

[0141] [Comparative Example 1]

[0142] The metal wires were arranged so that the kind of the waveform shape, the waveform of the first wave, the waveform of the second wave, the value of A1 / λ1, the value of A2 / A1, and the value of λ2 / λ1 were as shown in Table 1 below, and otherwise, a sheet-shaped conductive member was obtained similarly to Example 1.

[0143] [Comparative Example 2]

[0144] The waveform shape was set to a single waveform shape (sine wave), and the metal wires were arranged so that the value of A1 / λ1 of the sine wave was as shown in Table 1 below, and otherwise, the sheet-shaped conductive member was obtained in the same manner as in Example 1.

[0145] [Assessment of elongation]

[0146] The obtained sheet-shaped conductive member was used as a sample. An adherend of a SUS-made hemisphere having a radius of 5 mm was prepared, and the sample was attached to the surface thereof, and left to stand for 1 hour, and the occurrence of metal wire breakage, ease of attachment, and presence or absence of floating peeling were confirmed. Then, the elongation of the sheet-shaped conductive member was assessed in accordance with the following criteria.

[0147] A: No problems such as breakage of the wires and floating peeling were observed, and the attachment suitability (ease of attachment) was good.

[0148] B: No breakage of the wires and floating peeling were observed, but the operability at the time of attachment was reduced due to the difference in followability between the amplitude direction and the wavelength direction.

[0149] C: Floating peeling of the wires from the resin layer occurred in part of the wires, but no breakage of the wires was observed.

[0150] D: Significant floating peeling of the wires from the resin layer occurred, and breakage of the wires occurred.

[0151] [Assessment of wire contact possibility]

[0152] The wire contact possibility of the obtained sheet-shaped conductive member was assessed in accordance with the following criteria. The obtained results are shown in Table 1.

[0153] A: The interval of the parts where the wires are closest to each other was 0.3 mm or more.

[0154] B: The interval of the parts where the wires are closest to each other was less than 0.3 mm.

[0155] [Table 1]

[0156]

[0157] It was confirmed from the results shown in Table 1 that the sheet-shaped conductive members obtained in Examples 1 to 19 were excellent in elongation compared to the sheet-shaped conductive members obtained in Comparative Examples 1 and 2.

[0158] From the results of Examples 1 to 6, it was found that when the value of A1 / λ1 was set to 1 / 2, the elongation was good in the range where the value of A2 / A1 was 1 / 10 or more and 5 / 10 or less, and the elongation was good in the range where the value of λ2 / λ1 was 1 / 3 or more and 1 / 11 or less.

[0159] From the results of Examples 14 to 16, it is known that the elongation of the composite waveform shape of the fractal type is improved compared with the composite waveform shape of the synthetic type.

[0160] From the results of Examples 17 to 19, it is known that the elongation is improved by changing the waveform of the first wave from the sine wave to the semicircular wave, and the possibility of line contact can be reduced.

Claims

1. A sheet-like conductive member comprising a sheet-like structure formed by a plurality of conductive linear bodies arranged at intervals, wherein the conductive linear bodies are in a wave shape when the sheet-like conductive member is viewed in plan, the wave shape is a shape in which a second wave having an amplitude shorter than that of a first wave is provided along the first wave, the amplitude of the first wave is set as Al, the amplitude of the second wave is set as A2, and the wavelength of the first wave is set as λl, the following mathematical expressions (Fl) and (F2) are satisfied, 1 / 20 ≤ Al / λl ≤ 1 (Fl) 1 / 10 ≤ A2 / Al ≤ 3 / 5 (F2).

2. The sheet-like conductive member according to claim 1, wherein the wavelength of the first wave is set as λl, and the wavelength of the second wave is set as λ2, the following mathematical expression (F3) is satisfied, 1 / 21 ≤ λ2 / λl ≤ 1 / 3 (F3).

3. The sheet-like conductive member according to claim 1, wherein the conductive linear bodies are at least one selected from the group consisting of a linear body containing a metal wire, a linear body containing a carbon nanotube, and a linear body in which a wire is coated with a conductive material.

4. The sheet-like conductive member according to claim 1, further comprising an elastic substrate that supports the sheet-like structure.

5. The sheet-like conductive member according to any one of claims 1 to 4, which is used as a heating element.

6. A sheet-like heater comprising the sheet-like conductive member according to any one of claims 1 to 5. ​ ​ ​ ​

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