Wiring sheet and sheet heater

Abstract

The wiring sheet has a plurality of electrically conductive linear bodies (21) having an approximately sheet structure (2) in which the electrically conductive linear bodies (21) are arranged at intervals, a pair of electrodes (4), and first and second power supply portions (51, 52) provided respectively to the electrodes (4), in a case where the number of the electrically conductive linear bodies (21) is N, the resistance value of the electrically conductive linear bodies (21) is r, the resistance value of the electrodes (4) is R, and the resistance value of the electrodes (4) between the n-th electrically conductive linear body (21) and the (n-1)-th electrically conductive linear body (21) counted from the first and second power supply portions (51, 52) is Rn, all of the following conditions expressed by the following mathematical expression (F1), the following mathematical expression (F2), and the following mathematical expression (F3) are satisfied. n r / R ≤ 300 … (F1) Rn ≤ R … (F2) 0 < R2-Rn … (F3) n n－1 N In the mathematical expression (F2), n is an integer of 2 or more.​​

Description

TECHNICAL FIELD

[0001] The present application relates to a wiring sheet and a sheet heater. BACKGROUND

[0002] A sheet-shaped conductive member (hereinafter, also referred to as "conductive sheet") having a plurality of conductive linear bodies having an approximately sheet configuration arranged at intervals has a possibility of being able to be used as a heating body of a heating device, a material of a heat-generating textile, a protective film (shredding prevention film) for a display, and the like.

[0003] As a sheet for a heating body, for example, a conductive sheet having a plurality of linear bodies extending in one direction having an approximately sheet configuration arranged at intervals is described in Patent Literature 1. Further, by providing a pair of electrodes at both ends of the plurality of linear bodies, a wiring sheet capable of being used as a heating body can be obtained.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: International Publication No. 2017 / 086395 SUMMARY OF THE INVENTION

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] As an electrode used for a wiring sheet, a metal foil or a silver paste is generally used. However, from the viewpoint of the flexibility of the electrode portion of the wiring sheet, the use of a metal wire or the like instead of the metal foil or the silver paste is being studied. On the other hand, in the case where a thin electrode such as a metal wire is used as an electrode, the resistance value of the electrode becomes relatively large. Thus, the difference in the resistance value between the linear bodies as heating portions becomes small, and the resistance value of the electrode, which should originally be able to be ignored, becomes unable to be ignored. As a result, it is possible that temperature unevenness occurs when a current is caused to flow to the wiring sheet to heat the wiring sheet.

[0009] An object of the present application is to provide a wiring sheet and a sheet heater capable of suppressing temperature unevenness.

[0010] TECHNICAL SOLUTION FOR SOLVING THE PROBLEMS

[0011] One aspect of the present application relates to a wiring sheet characterized by comprising a plurality of conductive linear bodies having an approximately sheet configuration arranged at intervals, a pair of electrodes, and a first power supply portion and a second power supply portion provided to the electrodes, respectively, in which the number of the conductive linear bodies is set to N, the resistance value of the conductive linear bodies is set to r, the resistance value of the electrodes is set to R, the resistance value of the electrodes between the n-th conductive linear body and the (n-1)-th conductive linear body counted from the first power supply portion and the second power supply portion is set to Rn, and the following expression is satisfied. nIn the case where the temperature unevenness is suppressed, all of the following conditions shown by the following mathematical expression (F1), the following mathematical expression (F2), and the following mathematical expression (F3) are satisfied,

[0012] r / R ≤ 300 … (F1)

[0013] R n ≤ R n－1 … (F2)

[0014] 0 < R2 - R N … (F3)

[0015] In the mathematical expression (F2), n is an integer of 2 or more.

[0016] In the wiring sheet according to one aspect of the present application, the interval of the electrically conductive linear bodies is preferably 20 mm or less.

[0017] In the wiring sheet according to one aspect of the present application, it is preferable that a base material that supports the approximate sheet structure be further provided.

[0018] The sheet-shaped heater according to one aspect of the present application is characterized by including the wiring sheet according to one aspect of the present application described above.

[0019] According to the present application, it is possible to provide a wiring sheet and a sheet-shaped heater that can suppress temperature unevenness. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic view that shows a wiring sheet according to a first embodiment of the present application.

[0021] Figure 2 is a cross-sectional view that shows a II-II cross section of Figure 1

[0022] Figure 3 is a schematic view that shows a wiring sheet according to a second embodiment of the present application.

[0023] Figure 4 is a graph that shows the relationship between the consumed electric power and the number of the electrically conductive linear bodies in the analysis of the consumed electric power distribution. DETAILED DESCRIPTION

[0024] [First Embodiment]

[0025] Hereinafter, the present application will be described based on the drawings with the embodiments as examples. The present application is not limited to the contents of the embodiments. Note that in the drawings, there are parts that are enlarged or reduced for easy explanation.

[0026] (Wiring Sheet)

[0027] As Figure 1 and​Figure 2 As shown in the drawing, the wiring sheet 100 according to the present embodiment includes a base material 1, a sheet-like structure 2, a resin layer 3, and a pair of electrodes 4. Specifically, the wiring sheet 100 has the resin layer 3 stacked on the base material 1, and the sheet-like structure 2 stacked on the resin layer 3. In the sheet-like structure 2, a plurality of conductive linear bodies 21 are arranged at intervals. Further, the first power supply portion 51 is provided on one of the electrodes 4, and the second power supply portion 52 is provided on the other of the electrodes 4.

[0028] In the present embodiment, in a case where the number of the conductive linear bodies 21 is N, the resistance value of the conductive linear bodies 21 is r [Ω], the resistance value of the electrodes 4 is R [Ω], and the resistance value of the electrodes 4 between the n-th conductive linear body 21 and the (n-1)-th conductive linear body 21 counted from the first power supply portion 51 and the second power supply portion 52 is Rn [Ω], all of the conditions shown in the following mathematical expressions (F1), (F2), and (F3) need to be satisfied. n [Ω]. In a case where the value of r / R exceeds 300, the resistance value of the conductive linear body 21 as a heat generating portion is sufficiently large compared to the resistance value of the electrodes 4. Thus, in the wiring sheet 100, the resistance value of the electrodes 4 can be almost ignored, and the problem of temperature unevenness is not likely to occur in the first place.

[0029] Here, the "n-th conductive linear body counted from the first power supply portion 51 and the second power supply portion 52" refers to the conductive linear body 21 that is electrically connected to the pair of electrodes 4 and is the n-th in the number of the wires along the wiring sheet 100 from the first power supply portion 51 and the second power supply portion 52.

[0030] In the present embodiment, the condition shown in the following mathematical expression (F1) needs to be satisfied.

[0031] r / R ≤ 300 … (F1)

[0032] In a case where the value of r / R exceeds 300, the resistance value of the conductive linear body 21 as a heat generating portion is sufficiently large compared to the resistance value of the electrodes 4. Thus, in the wiring sheet 100, the resistance value of the electrodes 4 can be almost ignored, and the problem of temperature unevenness is not likely to occur in the first place.

[0033] In contrast, as the value of r / R becomes smaller, the problem of temperature unevenness becomes more likely to occur, and thus the use of the wiring sheet 100 according to the present embodiment becomes more meaningful.

[0034] The value of r / R can also be 200 or less, and can also be 100 or less. However, if the value of r / R is too small, heat is generated even in the electrodes 4, and thus the value of r / R is preferably 10 or more.

[0035] In the present embodiment, the condition shown in the following mathematical expression (F2) needs to be satisfied.

[0036] Rn ≤ R … (F2) n n－1 … (F2)

[0037] ​When the condition shown in mathematical expression (F2) is not satisfied, temperature unevenness cannot be suppressed.

[0038] In mathematical expression (F2), n is an integer of 2 or more. Also, the upper limit of n is the number N of the conductive linear bodies 21.

[0039] The number N of the conductive linear bodies 21 is preferably 3 or more, more preferably 5 or more, and further preferably 10 or more. Temperature unevenness has a tendency to occur more easily as the number of the conductive linear bodies 21 increases, but according to the wiring sheet 100 related to the present embodiment, temperature unevenness can be suppressed even when the number of the conductive linear bodies 21 is large. Note that the upper limit of the number N of the conductive linear bodies 21 is not particularly limited, but is, for example, 150.

[0040] In the present embodiment, the condition shown in the following mathematical expression (F3) needs to be satisfied.

[0041] 0 < R2 - R N (F3)

[0042] When the condition shown in mathematical expression (F3) is not satisfied, temperature unevenness cannot be suppressed.

[0043] Also, from the viewpoint of further suppressing temperature unevenness, the value of R2 - R N is preferably R / 4N or more, more preferably R / 2N or more, and further preferably R / N or more. Note that the value of R2 - R N does not exceed the value of the resistance R of the electrode 4.

[0044] The present inventors speculate that the reason why temperature unevenness can be suppressed when all the conditions shown in mathematical expressions (F1), (F2), and (F3) are satisfied is as follows.

[0045] That is, when the condition of mathematical expression (F1) is satisfied, the difference between the resistance value of the conductive linear body 21 as a heat generating portion and the resistance value of the electrode 4 becomes small, and the resistance value of the electrode 4, which should originally be able to be ignored, becomes unable to be ignored. As a result, when current is caused to flow to the wiring sheet 100 to heat the wiring sheet 100, temperature unevenness sometimes occurs. The reason is that the influence of the resistance of the electrode 4 up to the conductive linear body 21 becomes large for the conductive linear body 21 that is far from the first power supply portion 51 and the second power supply portion 52. Thus, the present inventors speculate that when current is caused to flow to the wiring sheet 100 to heat the wiring sheet 100, the current flowing in the conductive linear body 21 is relatively small, and the temperature becomes lower than that of other conductive linear bodies 21.

[0046] In contrast, under the conditions shown in mathematical formulas (F2) and (F3), the further away from the first power supply unit 51 and the second power supply unit 52, the greater the resistance value R of the electrode 4 between the nth conductive wire 21 and the (n-1)th conductive wire 21. n The lower the value, the greater the influence on the resistance of the electrode 4 up to the conductive wire 21, which is farther away from the first power supply section 51 and the second power supply section 52. However, the resistance value R of the electrode 4 is still relatively constant. n Lowering the temperature accordingly suppresses this effect. The inventors speculate that this can suppress temperature unevenness.

[0047] The resistance values ​​of the conductive wire 21 and the electrode 4 can be appropriately set by known methods, such as by changing the material, cross-sectional area and length.

[0048] For example, such as Figure 1 As shown, if the cross-sectional area of ​​electrode 4 is made larger the further it is from the first power supply section 51 and the second power supply section 52, then the resistance value of electrode 4 can be lower the further it is from the first power supply section 51 and the second power supply section 52. In addition, as the material of the electrode, a material with higher electrical conductivity the further it is from the first power supply section 51 and the second power supply section 52 can be used.

[0049] (Substrate)

[0050] Examples of substrate 1 include synthetic resin films, paper, metal foil, nonwoven fabrics, cloth, and glass films. This substrate 1 can directly or indirectly support the approximate sheet structure 2. Furthermore, substrate 1 is preferably a flexible substrate.

[0051] Synthetic resin films, paper, nonwoven fabrics, and cloths can be used as flexible substrates. Among these flexible substrates, synthetic resin films, nonwoven fabrics, or cloths are preferred, with nonwoven fabrics or cloths being more preferred.

[0052] Examples of synthetic resin films include polyethylene films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, polyethylene copolymer films, polyethylene terephthalate films, polyethylene naphthalate films, polybutylene terephthalate films, polyurethane films, ethylene vinyl acetate copolymer films, ionomer resin films, ethylene-(meth)acrylate copolymer films, ethylene-(meth)acrylate copolymer films, polystyrene films, polycarbonate films, and polyimide films. In addition, cross-linked films and laminated films of these materials can be used as flexible substrates.

[0053] In addition, as the paper, for example, high-quality paper, recycled paper, and kraft paper, and the like can be given. As the nonwoven fabric, for example, spun-bond nonwoven fabric, needle punch nonwoven fabric, melt-blown nonwoven fabric, and water-jet nonwoven fabric, and the like can be given. As the cloth, for example, woven fabric and knitted fabric, and the like can be given. The paper, nonwoven fabric, and cloth as the soft base material are not limited to them.

[0054] (approximate sheet structure)

[0055] The approximate sheet structure 2 is a structure in which a plurality of electrically conductive linear bodies 21 are arranged with intervals. The electrically conductive linear body 21 is linear in plan view of the wiring sheet 100. Also, the approximate sheet structure 2 is a structure in which the electrically conductive linear bodies 21 are arranged in a plurality in a direction intersecting with the axial direction of the electrically conductive linear body 21.

[0056] Note that the electrically conductive linear body 21 can also be in a wave shape in plan view of the wiring sheet 100. As the wave shape, specifically, the electrically conductive linear body 21 can be, for example, a sine wave, a circular wave, a rectangular wave, a triangular wave, a sawtooth wave, and the like. If the approximate sheet structure 2 is such a structure, when the wiring sheet 100 is stretched in the axial direction of the electrically conductive linear body 21, the breakage of the electrically conductive linear body 21 can be suppressed.

[0057] The volume resistivity of the electrically 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. If the volume resistivity of the electrically conductive linear body 21 is in the above range, the surface resistance of the approximate sheet structure 2 easily decreases.

[0058] The volume resistivity of the electrically conductive linear body 21 is measured as follows. Silver paste is applied to both ends of the electrically conductive linear body 21, the resistance of a portion of 40 mm from the end is measured, and the resistance value of the electrically conductive linear body 21 is found. Then, the cross-sectional area (unit: m 2 ) of the electrically conductive linear body 21 is multiplied by the above resistance value, the obtained value is divided by the above measured length (0.04 m), and the volume resistivity of the electrically conductive linear body 21 is calculated.

[0059] The shape of the cross section of the electrically conductive linear body 21 is not particularly limited, and a polygonal shape, a flat shape, an elliptical shape, or a circular shape, and the like can be adopted, but from the viewpoint of fusion with the resin layer 3 and the like, an elliptical shape or a circular shape is preferred.

[0060] In the case where the cross section of the electrically conductive linear body 21 is a circular shape, the thickness (diameter) D (refer to FIG. 2) of the electrically conductive linear body 21 is preferably 1.0 x 10 Figure 2) is preferably 5 μm or more and 75 μm or less. From the viewpoint of suppressing an increase in sheet resistance and improving the heat generation efficiency and the insulation breakdown resistance in the case where the wiring sheet 100 is used as a heat generator, the diameter D of the conductive linear bodies 21 is more preferably 8 μm or more and 60 μm or less, and further preferably 12 μm or more and 40 μm or less.

[0061] In the case where the cross section of the conductive linear bodies 21 is an elliptical shape, the major axis is preferably within the same range as the diameter D described above.

[0062] As for the diameter D of the conductive linear bodies 21, the conductive linear bodies 21 of the sheet-like structure body 2 are observed using a digital microscope, the diameters of the conductive linear bodies 21 are measured at five randomly selected points, and the average value thereof is taken as the diameter D.

[0063] The interval L of the conductive linear bodies 21 (refer to Figure 2 ) is preferably 20 mm or less, more preferably 0.5 mm or more and 15 mm or less, and further preferably 1 mm or more and 10 mm or less.

[0064] If the interval of the conductive linear bodies 21 from each other is within the range described above, the conductive linear bodies are somewhat dense, and thus it is possible to seek an improvement in the function of the wiring sheet 100, such as maintaining the resistance of the sheet-like structure body low, and making the distribution of temperature rise in the case where the wiring sheet 100 is used as a heat generator uniform.

[0065] As for the interval L of the conductive linear bodies 21, the conductive linear bodies 21 of the sheet-like structure body 2 are observed using the naked eye or a digital microscope, and the interval of two adjacent conductive linear bodies 21 is measured.

[0066] Note that the interval of two adjacent conductive linear bodies 21 is the length along the direction in which the conductive linear bodies 21 are arranged, and is the length between the facing portions of the two conductive linear bodies 21 (refer to Figure 2 ). In the case where the arrangement of the conductive linear bodies 21 is unequal intervals, the interval L is the average value of the intervals of all adjacent conductive linear bodies 21 from each other.

[0067] The conductive linear bodies 21 are not particularly limited, but are preferably linear bodies containing a metal wire (hereinafter also referred to as "metal wire linear bodies"). The metal wire has high thermal conductivity, high electrical conductivity, high handleability, and versatility, and thus, if the metal wire linear bodies are applied as the conductive linear bodies 21, it is easy to improve the light transmittance while reducing the resistance value of the sheet-like structure body 2. In addition, in the case where the wiring sheet 100 (sheet-like structure body 2) is applied as a heat generator, it is easy to achieve rapid heat generation. Furthermore, as described above, it is easy to obtain linear bodies having a fine diameter.

[0068] 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 to which an electrically conductive coating is applied to a wire can be given.

[0069] The metal wire linear member can be a linear member composed of one metal wire, or a linear member obtained by twisting a plurality of metal wires.

[0070] As the metal wire, a wire including a metal such as copper, aluminum, tungsten, iron, molybdenum, nickel, titanium, silver, gold, or an alloy including two or more of these metals (for example, stainless steel, carbon steel, brass, phosphor bronze, zirconium copper alloy, beryllium copper, iron-nickel, nickel-chromium, nickel-titanium, Kanthal, hastelloy, and rhenium-tungsten) can be given. In addition, the metal wire can be a wire plated with tin, zinc, silver, nickel, chromium, nickel-chromium alloy, or solder, or a wire having a surface coated with a carbon material or a polymer described later. In particular, a wire including one or more metals selected from tungsten, molybdenum, and alloys including these metals is preferable from the viewpoint of forming the conductive linear member 21 having a low volume resistivity.

[0071] As the metal wire, a wire coated with a carbon material can also be given. If the metal wire is coated with a carbon material, the metallic luster is reduced, and the presence of the metal wire is less conspicuous. In addition, if the metal wire is coated with a carbon material, metal corrosion is also suppressed.

[0072] As the carbon material coating 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, and the like can be given.

[0073] The linear body containing carbon nanotubes is obtained, for example, by the following method: pulling out carbon nanotubes in a sheet form from the end of a carbon nanotube forest (a growth body obtained by growing a plurality of carbon nanotubes in a vertical direction with respect to a substrate on the substrate, sometimes referred to as an "array"), bundling the pulled-out carbon nanotube sheet, and twisting the bundle of carbon nanotubes. In such a manufacturing method, a linear body of carbon nanotubes in a tape shape is obtained without applying a twist at the time of twisting, and a linear body of carbon nanotubes in a thread shape is obtained with a twist applied. The linear body of carbon nanotubes in a tape shape is a linear body that does not have a configuration in which carbon nanotubes are twisted. In addition, a linear body of carbon nanotubes can also be obtained by spinning or the like from a dispersion liquid of carbon nanotubes. The manufacturing of a linear body of carbon nanotubes 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 linear body of carbon nanotubes, it is preferable to use a linear body of carbon nanotubes in a thread shape, and from the viewpoint of obtaining a linear body of carbon nanotubes with high purity, it is preferable to obtain a linear body of carbon nanotubes in a thread shape by twisting a sheet of carbon nanotubes. The linear body of carbon nanotubes can also be a linear body in which two or more linear bodies of carbon nanotubes are woven together. In addition, the linear body of carbon nanotubes can also be a linear body in which carbon nanotubes and another conductive material are compounded (hereinafter also referred to as a "composite linear body").

[0074] As the composite linear body, for example, there are (1) a composite linear body in which a metal single body or a metal alloy is supported on the surface of a forest, a sheet, or a bundle of carbon nanotubes or a linear body twisted therefrom by vapor deposition, ion plating, sputtering, wet etching, or the like during the process of obtaining a linear body of carbon nanotubes by pulling out carbon nanotubes in a sheet form from the end of a carbon nanotube forest, bundling the pulled-out carbon nanotube sheet, and twisting the bundle of carbon nanotubes, (2) a composite linear body obtained by twisting a bundle of carbon nanotubes together with a linear body of a metal single body or a linear body or a composite linear body of a metal alloy, and (3) a composite linear body obtained by weaving a linear body of a metal single body or a linear body or a composite linear body of a metal alloy and a linear body or a composite linear body of carbon nanotubes. Note that in the composite linear body of (2), the carbon nanotubes can also be supported with a metal 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 in the case where two linear bodies are woven, but as long as it contains at least one linear body of a metal single body or a linear body or a composite linear body of a metal alloy, three or more of a linear body or a composite linear body of carbon nanotubes or a linear body or a composite linear body of a metal single body or a metal alloy can also be woven together.

[0075] As the metal of the composite linear body, for example, there can be mentioned metal monomers such as gold, silver, copper, iron, aluminum, nickel, chromium, tin, zinc, and alloys containing at least one of these metal monomers (copper-nickel-phosphorus alloy, copper-iron-phosphorus-zinc alloy, and the like).

[0076] The conductive linear body 21 can also be a linear body to which a conductive coating is applied to a thread. As the thread, there can be mentioned a thread obtained by spinning a resin such as nylon, polyester, or the like. As the conductive coating, there can be mentioned a coating film of a metal, a conductive polymer, a carbon material, or the like. The conductive coating can be formed by plating or vapor deposition, or the like. The linear body to which the conductive coating is applied to the thread can increase the conductivity of the linear body while maintaining the softness of the thread. That is, it is easy to decrease the resistance of the sheet-like structure 2.

[0077] (resin layer)

[0078] 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 resin layer 3 forms the sheet-like structure 2, by the adhesive, the attachment of the conductive linear body 21 to the resin layer 3 becomes easy.

[0079] The resin layer 3 can also be a layer composed of a resin capable of drying or curing. Thereby, the resin layer 3 is imparted with 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 the deformation of the wiring sheet 100 caused by an impact.

[0080] The resin layer 3 is preferably energy ray-curable, in terms of being able to be cured in a short time and easily. Note that "energy ray curing" also includes thermal curing based on heating using an energy ray.

[0081] As the adhesive of the resin layer 3, there can be mentioned a thermosetting adhesive that is cured by heat, a so-called heat-seal type adhesive that is adhered by heat, an adhesive that exhibits adhesiveness by being wetted, and the like. However, from the viewpoint of the ease of application, the resin layer 3 is preferably energy ray-curable. As the energy ray-curable resin, for example, there can be mentioned a compound having at least one polymerizable double bond in the molecule, and an acrylate-based compound having a (meth)acryloyl group is preferable.

[0082] As the acrylic-based compound, for example, there can be mentioned (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.), (meth)acrylate containing a cyclic aliphatic skeleton (dicyclopentyl di(meth)acrylate and dicyclopentadiene di(meth)acrylate, etc.), polyalkylene glycol (meth)acrylate (polyethylene glycol di(meth)acrylate, etc.), oligomeric ester (meth)acrylate, polyurethane (meth)acrylate oligomer, epoxy-modified (meth)acrylate, polyether (meth)acrylate other than the polyalkylene glycol (meth)acrylate, itaconic acid oligomer, and the like.

[0083] The weight average molecular weight (Mw) of the energy ray-curable resin is preferably 100 to 30,000, and more preferably 300 to 10,000.

[0084] The energy ray-curable resin contained in the adhesive composition can be only one kind, or two or more kinds, and in the case of two or more kinds, the combination and ratio thereof can be arbitrarily selected. Also, it can be combined with the thermoplastic resin described later, and the combination and ratio thereof can be arbitrarily selected.

[0085] 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. For example, as the adhesive, there can be mentioned an acrylic adhesive, a polyurethane adhesive, a rubber-based adhesive, a polyester-based adhesive, a silicone-based adhesive, a polyvinyl ether-based adhesive, and the like. Among them, the adhesive is preferably at least any one selected from among an acrylic adhesive, a polyurethane adhesive, and a rubber-based adhesive, and more preferably an acrylic adhesive.

[0086] As the acrylic adhesive, for example, there can be mentioned a polymer containing a constitutional unit derived from an alkyl (meth)acrylate having a straight chain or a branched chain alkyl group (that is, a polymer obtained by polymerizing at least an alkyl (meth)acrylate), an acrylic polymer containing a constitutional unit derived from a (meth)acrylate having a cyclic structure (that is, a polymer obtained by polymerizing at least a (meth)acrylate having a cyclic structure), and the like. Here, "(meth)acrylate" is used as a term indicating both "acrylate" and "methacrylate", and the same applies to other similar terms.

[0087] In the case where the acrylic polymer is a copolymer, the mode of copolymerization is not particularly limited. As the acrylic copolymer, any one of a block copolymer, a random copolymer, and a graft copolymer can be used.

[0088] In the case where the acrylic polymer is a copolymer, the mode of copolymerization is not particularly limited. As the acrylic copolymer, any one of a block copolymer, a random copolymer, and a graft copolymer can be used.

[0089] The acrylic copolymer can also be crosslinked by a crosslinking agent. As the crosslinking agent, for example, a publicly known epoxy-based crosslinking agent, an isocyanate-based crosslinking agent, an aziridine-based crosslinking agent, a metal chelate-based crosslinking agent, and the like can be cited. 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, or the like, which reacts with these crosslinking agents, can be introduced into the acrylic copolymer.

[0090] In the case where the resin layer 3 is formed of an adhesive, the resin layer 3 can also contain the above-described energy ray-curable resin 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 which reacts with the functional group derived from the monomer component of the acrylic copolymer and an energy ray-polymerizable functional group in one molecule can also be used. By the reaction of the functional group of this compound with the functional group derived from the monomer component of the acrylic copolymer, the side chain of the acrylic copolymer can be polymerized by energy ray irradiation. In the case where the adhesive is not an acrylic adhesive, as the polymer component other than the acrylic polymer, a component whose side chain is energy ray-polymerizable can also be used in the same manner.

[0091] As the thermosetting resin used for the resin layer 3, no particular limitation is imposed, and specifically, an epoxy resin, a phenol resin, a melamine resin, a urea resin, a polyester resin, a polyurethane resin, an acrylic resin, a benzoxazine resin, a phenoxy resin, an amine-based compound, an acid anhydride-based compound, and the like can be cited. These can be used alone as one kind or in combination of two or more kinds. Among them, from the viewpoint of being suitable 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 curability, 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.

[0092] As the moisture-curable resin used for the resin layer 3, no particular limitation is imposed, and a polyurethane resin which generates an isocyanate group due to moisture, a modified silicone resin, and the like can be cited.

[0093] In the case of using the energy ray-curable resin or the thermosetting resin, it is preferable to use a photopolymerization initiator or a thermal polymerization initiator, or the like. By using the photopolymerization initiator or the thermal polymerization initiator, or the like, a crosslinked structure is formed, and the near sheet structure body 2 can be more firmly protected.

[0094] As the photopolymerization initiator, 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 ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethyl thiuram monosulfide, azobisisobutyronitrile, 2-chloroanthraquinone, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, and bis (2,4,6-trimethylbenzoyl) -phenyl phosphine oxide, and the like can be given.

[0095] As the thermal polymerization initiator, hydrogen peroxide, peroxodisulfate (ammonium peroxodisulfate, sodium peroxodisulfate, and potassium peroxodisulfate, and the like), 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), and the like), and organic peroxides (benzoyl peroxide, lauryl peroxide, peracetic acid, peroxysuccinic acid, di-t-butyl peroxide, t-butyl hydroperoxide, and cumene hydroperoxide, and the like) can be given.

[0096] These polymerization initiators can be used alone or in combination of two or more.

[0097] In the case of using these polymerization initiators to form a crosslinked structure, the amount of use 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, with respect to 100 parts by mass of the energy ray-curable resin or the thermosetting resin.

[0098] The resin layer 3 can also be uncured and, for example, is a layer composed of a thermoplastic resin composition. Also, by containing a solvent in the thermoplastic resin composition, the thermoplastic resin layer can be softened. Thereby, when the near sheet structure body 2 is formed in the resin layer 3, the adhesion of the conductive linear body 21 to the resin layer 3 becomes easy. On the other hand, by volatilizing the solvent in the thermoplastic resin composition, the thermoplastic resin layer can be dried and cured.

[0099] As the thermoplastic resin, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polyurethane, polyether, polyethersulfone, polyimide, and acrylic resin, and the like can be given.

[0100] Examples of solvents include alcohol solvents, ketone solvents, ester solvents, ether solvents, hydrocarbon solvents, haloalkyl solvents, and water.

[0101] The resin layer 3 may also contain inorganic fillers. By including inorganic fillers, the hardness of the cured resin layer 3 can be further improved. In addition, the thermal conductivity of the resin layer 3 is improved.

[0102] Examples of inorganic filler materials include inorganic powders (e.g., silica, alumina, talc, calcium carbonate, titanium dioxide, iron oxide red, silicon carbide, and boron nitride powders), beads obtained by spheroidizing inorganic powders, single-crystal fibers, and glass fibers. Among these, silica fillers and alumina fillers are preferred as inorganic filler materials. One type of inorganic filler material can be used alone, or two or more types can be used in combination.

[0103] Other components may also be included in resin layer 3. Examples of such other components include well-known additives such as organic solvents, flame retardants, adhesives, UV absorbers, antioxidants, preservatives, mildew inhibitors, plasticizers, defoamers, and wetting modifiers.

[0104] The thickness of the resin layer 3 is appropriately determined according to the application of the wiring sheet 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, more preferably 5 μm or more and 100 μm or less.

[0105] (electrode)

[0106] Electrode 4 is used to supply current to the conductive wire 21. Electrode 4 can be formed using known electrode materials. Examples of electrode materials include conductive paste (silver paste, etc.), metal foil (copper foil, etc.), and metal wire. Electrode 4 is electrically connected to both ends of the conductive wire 21 and disposed at those ends.

[0107] Examples of metals that can be used as foils or wires include copper, aluminum, tungsten, iron, molybdenum, nickel, titanium, silver, gold, and alloys containing two or more metals (e.g., stainless steel, carbon steel, brass, phosphor bronze, zirconium copper alloy, beryllium copper, iron-nickel, nickel-chromium, nickel-titanium, Kanthal, Hastelloy, and rhenium-tungsten). Additionally, the foils or wires may be plated with tin, zinc, silver, nickel, chromium, nickel-chromium alloys, or solder. In particular, materials containing one or more metals selected from copper, silver, and alloys containing them are preferred from the viewpoint of having low volume resistivity.

[0108] like Figure 1 As shown, the width of electrode 4 can be wider the further away from the first power supply section 51 and the second power supply section 52.

[0109] In such a case, the average width of the electrode 4 is preferably 100 mm or less, more preferably 10 mm or less, and further preferably 100 μm or less, in a plan view of the approximate tab structure 2. The narrower the width of the electrode 4, the more the tendency to generate temperature unevenness is suppressed, but even in the case where the width of the electrode 4 is narrow, the temperature unevenness can be suppressed according to the wiring tab 100 related to the present embodiment.

[0110] The ratio of the resistance value of the electrode 4 to the resistance value of the approximate tab structure 2 (resistance value of the electrode 4 / resistance value of the approximate tab 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 approximate tab structure 2 can be calculated by "resistance value of the electrode 4 / resistance value of the approximate tab structure 2". By being in this range, in the case where the wiring tab 100 is used as a heat generating body, abnormal heat generation at the electrode portion is suppressed. In the case where the approximate tab structure 2 is used as a tab heater, only the approximate tab structure 2 generates heat, and a tab heater with good heat generation efficiency can be obtained.

[0111] The resistance values of the electrode 4 and the approximate tab structure 2 can be measured using a tester. First, the resistance value of the electrode 4 is measured, and the resistance value of the approximate tab structure 2 to which the electrode 4 is attached is measured. Thereafter, the resistance values of the electrode 4 and the approximate tab structure 2 are calculated by subtracting the measured value of the electrode 4 from the resistance value of the approximate tab structure 2 to which the electrode is attached.

[0112] (Power supply portion)

[0113] The first power supply portion 51 and the second power supply portion 52 are portions that apply a voltage to the wiring tab 100. In the case where the electrode 4 is exposed and can be electrically connected, any portion of the electrode 4 can be used as the first power supply portion 51 or the second power supply portion 52.

[0114] In addition, in order to easily connect a power source (not shown) to the electrode 4, the first power supply portion 51 and the second power supply portion 52 can be provided separately. In this case, as the material of the first power supply portion 51 and the second power supply portion 52, the same material as that of the electrode 4 can be used. In addition, in the case where the electrode 4 is covered with an insulating material for preventing short circuiting and the like, a portion from which a part of the insulating material is removed can be used as the first power supply portion 51 and the second power supply portion 52.

[0115] (Method for manufacturing wiring tab)

[0116] The method for manufacturing the wiring tab 100 related to the present embodiment is not particularly limited. The wiring tab 100 can be manufactured, for example, by the following steps.

[0117] First, a composition for forming the resin layer 3 is applied to the substrate 1 to form a coating film. Next, the coating film is dried to produce the resin layer 3. Next, the electrically conductive linear bodies 21 are arranged and disposed on the resin layer 3 to form the approximately sheet-shaped structure 2. For example, in a state in which the resin layer 3 of the substrate 1 is disposed on the outer circumferential surface of a drum member, the drum member is rotated while the electrically conductive linear bodies 21 are wound on the resin layer 3 in a spiral shape. Thereafter, the bundle of the electrically conductive linear bodies 21 wound in the spiral shape is cut along the axial direction of the drum member. Thus, the approximately sheet-shaped structure 2 is formed and disposed on the resin layer 3. Then, the resin layer 3 of the substrate 1 on which the approximately sheet-shaped structure 2 is formed is taken out from the drum member to obtain a sheet-shaped conductive member. According to this method, for example, by moving the leading end portion of the electrically conductive linear bodies 21 in a direction parallel to the axis of the drum member while the drum member is rotated, it is easy to adjust the interval L between the adjacent electrically conductive linear bodies 21 in the approximately sheet-shaped structure 2.

[0118] Next, the electrodes 4 are attached to both end portions of the electrically conductive linear bodies 21 in the approximately sheet-shaped structure 2 of the sheet-shaped conductive member, and then the first power supply portion 51 and the second power supply portion 52 are provided, so that the wiring sheet 100 can be produced.

[0119] (Action effects of the first embodiment)

[0120] According to the present embodiment, the following action effects can be achieved.

[0121] (1) According to the present embodiment, by satisfying the conditions shown in mathematical expression (F2) and mathematical expression (F3), the cross-sectional area of the electrode 4 is made larger as it is farther from the first power supply portion 51 and the second power supply portion 52. Thus, it is possible to suppress temperature unevenness in the wiring sheet 100.

[0122] (2) In the present embodiment, since the width of the electrode 4 is made wider as it is farther from the first power supply portion 51 and the second power supply portion 52, it is possible to make the cross-sectional area of the electrode 4 larger as it is farther from the first power supply portion 51 and the second power supply portion 52.

[0123] (3) The wiring sheet 100 according to the present embodiment can suppress temperature unevenness, and thus can be appropriately used as a sheet-shaped heater.

[0124] [Second embodiment]

[0125] Next, the second embodiment of the present application will be described based on the drawings.

[0126] As Figure 3As shown in FIG. 1, the wiring sheet 100A according to the present embodiment includes a base material 1, a sheet-like structure 2, a resin layer 3, and a pair of electrodes 4A. In the sheet-like structure 2, a plurality of electrically conductive linear bodies 21 are arranged at intervals. The first power supply portion 51 is provided in one of the electrodes 4A, and the second power supply portion 52 is provided in the other of the electrodes 4A.

[0127] Note that, in the present embodiment, the same as the first embodiment except for the electrodes 4A, and thus the electrodes 4A will be described, and the portions common to the previous description will be omitted.

[0128] As shown in FIG. 1, the wiring sheet 100A according to the present embodiment includes a base material 1, a sheet-like structure 2, a resin layer 3, and a pair of electrodes 4A. In the sheet-like structure 2, a plurality of electrically conductive linear bodies 21 are arranged at intervals. The first power supply portion 51 is provided in one of the electrodes 4A, and the second power supply portion 52 is provided in the other of the electrodes 4A. Figure 3 As shown in FIG. 1, the wiring sheet 100A according to the present embodiment includes a base material 1, a sheet-like structure 2, a resin layer 3, and a pair of electrodes 4A. In the sheet-like structure 2, a plurality of electrically conductive linear bodies 21 are arranged at intervals. The first power supply portion 51 is provided in one of the electrodes 4A, and the second power supply portion 52 is provided in the other of the electrodes 4A.

[0129] (Action effects of the second embodiment)

[0130] According to the present embodiment, in addition to the action effects (1) and (3) in the first embodiment, the following action effect (4) can be achieved.

[0131] (4) In the present embodiment, since the number of the metal wires constituting the electrodes 4A increases as the distance from the first power supply portion 51 and the second power supply portion 52 increases, the cross-sectional area of the electrodes 4A can be made larger as the distance from the first power supply portion 51 and the second power supply portion 52 increases.

[0132] [Variations of the embodiments]

[0133] The present application is not limited to the foregoing embodiments, and variations, modifications, and the like within the scope of achieving the objects of the present application are included in the present application.

[0134] For example, in the foregoing embodiments, the wiring sheet 100 includes the base material 1, but is not limited thereto. For example, the wiring sheet 100 can not include the base material 1. In such a case, the wiring sheet 100 can be attached to an adherend by the resin layer 3 and used.

[0135] In the foregoing embodiments, the wiring sheet 100 includes the resin layer 3, but is not limited thereto. For example, the wiring sheet 100 can not include the resin layer 3. In such a case, the sheet-like structure 2 can be formed by using a knitted fabric as the base material 1 and knitting the electrically conductive linear bodies 21 into the base material 1.

[0136] [Confirmation of effects]

[0137] According to the present embodiment, in order to confirm that a wiring sheet capable of suppressing temperature unevenness can be obtained, the analysis of the consumed power distribution described below was performed.

[0138] In the analysis of the consumed power distribution, the wiring sheet related to the present embodiment was applied to a ladder-type circuit diagram, and the consumed power distribution in the circuit was analyzed.

[0139] As Example 1, the number of conductive linear bodies 21, N, was made 30, the resistance value r of the conductive linear bodies 21 was made 25070 [mΩ], the resistance value R of the electrode 4 was made 148 [mΩ], the value of the resistance value R2 of the electrode 4 between the 2nd conductive linear body 21 counted from the first power supply portion 51 and the second power supply portion 52 and the 1st conductive linear body 21 was made 10.21 [mΩ], and the value of the resistance value R 30 of the electrode 4 between the 30th conductive linear body 21 counted from the first power supply portion 51 and the second power supply portion 52 and the 29th conductive linear body 21 was made 0 [mΩ]. Note that the values [mΩ] of R3 to R 29 gradually decrease at the same rate (about 0.36 [mΩ] between adjacent electrodes) from the value of R2 to the value of R 30 .

[0140] Further, the consumed power distribution in the 1st conductive linear body 21 to the 30th conductive linear body 21 in the case where current flows to the above-described circuit was analyzed. Note that the conductive linear bodies 21 were given numbers, and the number of the nth conductive linear body 21 was made n. The obtained results are shown in Table 1. Figure 4 Note that the consumed power is a relative value in the case where the current of the power supply portion is 1.

[0141] In addition, as Example 2, the consumed power distribution was analyzed similarly to Example 1 except that the values of R2 to R 30 were not changed. Note that the values of R2 to R 30 each were 10.21 [mΩ]. The obtained results are shown in Table 2. Figure 4

[0142] Further, from the obtained consumed power distribution, the highest consumed power, the lowest consumed power, and the average consumed power were calculated, and the power unevenness (unit: ±%) was calculated based on the following calculation formula.

[0143] (Power unevenness) = [{(Highest consumed power) - (Lowest consumed power)} / (Average consumed power) / 2] x 100

[0144] ​It is known that the electric energy unevenness in Example 1 is ±35%, and that of Example 2 is ±47% lower. It is presumed that the smaller the electric energy unevenness, the more the temperature unevenness is suppressed.

[0145] BRIEF DESCRIPTION OF DRAWINGS

[0146] 1…substrate, 2…approximate sheet structure, 21…electrically conductive linear body, 3…resin layer, 4, 4A…electrode, 51…first power supply portion, 52…second power supply portion, 100, 100A…wiring sheet.

Claims

1. A wiring sheet comprising a plurality of electrically conductive linear bodies arranged at intervals to form a sheet-like structure, a pair of electrodes, and a first power supply portion and a second power supply portion respectively provided to the electrodes. In a case where the number of the electrically conductive linear members is N, the resistance value of the electrically conductive linear members is r, the resistance value of the electrode is R, and the resistance value of the electrode between the n-th electrically conductive linear member and the (n-1)-th electrically conductive linear member counted from the first power supply portion and the second power supply portion side is Rn-1, the following mathematical expression (F1), the following mathematical expression (F2), and the following mathematical expression (F3) are satisfied. n In a case where the number of the electrically conductive linear members is N, the resistance value of the electrically conductive linear members is r, the resistance value of the electrode is R, and the resistance value of the electrode between the n-th electrically conductive linear member and the (n-1)-th electrically conductive linear member counted from the first power supply portion and the second power supply portion side is Rn-1, the following mathematical expression (F1), the following mathematical expression (F2), and the following mathematical expression (F All conditions shown in the following mathematical expression (F2) and mathematical expression (F3) are satisfied. r / R ≤ 300 (F1) In the mathematical expression (F2), n is an integer of 2 or more. R n ≤R n-1 …(F2) 0 < R2 - R N …(F3) In the mathematical expression (F3), N is an integer of 3 or more.

2. The wiring sheet according to claim 1, The interval of the electrically conductive linear bodies is 20 mm or less.

3. The wiring sheet according to claim 1 or 2, Further comprising a base material that supports the sheet-like structure.

4. A sheet-like heater comprising the wiring sheet according to any one of claims 1 to 3. ​

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