Wiring sheet

Abstract

This wiring sheet (100) comprises a wiring body (2) provided with electrically conductive linear bodies (21), and a pair of electrodes (4) that are in direct contact with the electrically conductive linear bodies (21), wherein the electrically conductive linear bodies (21) have an infrared reflectance of 0% to 90% inclusive at a wavelength of 1000 nm, and have a rate of change in resistance value of 50% or less after being allowed to stand for 1000 hours in a hot, humid environment at a temperature of 85°C and a relative humidity of 85% RH.

Description

Wiring sheet

[0001] The present invention relates to a wiring sheet.

[0002] A wiring sheet having wiring members is known. This wiring sheet can be used, for example, as a material for heat-generating textiles, a component for generating heat in various articles, and a heating element of a heat-generating device applied to a sensor or the like.

[0003] Patent Document 1 discloses a wiring sheet equipped with a contact sensor. The sensor disclosed in Patent Document 1 is a contact sensor that includes a pseudo sheet structure in which a plurality of conductive linear members are arranged at intervals, a first electrode electrically connected to the conductive linear members, and a second electrode that is spaced apart from the pseudo sheet structure and the first electrode, intersects the conductive linear members but does not overlap with the first electrode in a plan view of the pseudo sheet structure.

[0004] Patent Document 2 discloses a pressure-sensitive heating element having a pressure-sensitive heating portion made of a foamed conductive material. In the pressure-sensitive heating element disclosed in Patent Document 2, the pressure-sensitive heating portion generates heat when current is applied, elastically deforms when subjected to a compressive load, and when current is applied and a compressive load is applied, the amount of heat generated increases as the compressive load increases. The pressure-sensitive heating element disclosed in Patent Document 2 is also provided with a conductive cloth.

[0005] Patent Document 3 discloses a transparent film heater having a transparent heat generating layer on the surface of a transparent film substrate. In the transparent film heater disclosed in Patent Document 3, the transparent heat generating layer contains at least metal nanowires.

[0006] International Publication No. 2023 / 063377 Japanese Patent Application Laid-Open No. 2019-204674 Japanese Patent Application Laid-Open No. 2010-103041

[0007] For example, gold-plated linear members are used in the wiring sheet of Patent Document 1. The wiring sheet disclosed in Patent Document 1 has high corrosion resistance even when used or stored in a humid and hot environment.

[0008] Incidentally, there are cases where wiring sheets are required to be configured as wiring sheets with higher design quality, for example. Furthermore, there are cases where wiring sheets are required to be configured as wiring sheets more suitable as heaters for optical sensors such as LiDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging). To meet these requirements, for example, it is conceivable to color the members used in the wiring sheets that enable electrical conduction black.

[0009] The pressure-sensitive heating element disclosed in Patent Document 2 uses a carbon-coated copper-nickel plated woven fabric as a conductive fabric that enables electrical conduction. When the pressure-sensitive heating element of Patent Document 2 is used or stored in a humid and hot environment, corrosion occurs due to the use of a carbon-coated copper-nickel plated woven fabric. For this reason, the pressure-sensitive heating element of Patent Document 2 has low corrosion resistance in a humid and hot environment. The transparent film heater of Patent Document 3 uses silver nanowires. It is disclosed that the silver nanowires used in the transparent film heater of Patent Document 3 are made into a silver alloy for sulfide stability. The silver nanowires are not blackened. Furthermore, the silver nanowires of Patent Document 3 have poor corrosion stability when used or stored in a humid and hot environment.

[0010] For example, it is believed that a wiring body with a more aesthetically pleasing design can be obtained by replacing the conductive linear bodies of the wiring body disclosed in Patent Document 1 with carbon-coated linear bodies as disclosed in Patent Document 2. However, when a wiring sheet is formed using carbon-coated linear bodies, there is a concern that corrosion may occur in the wiring sheet when it is used or stored in a humid and hot environment, for example, and the resistance value of the wiring sheet may increase.

[0011] An object of the present invention is to provide a wiring sheet that can suppress corrosion in a humid and hot environment while achieving blackening of conductive linear members.

[0012] [1] A wiring sheet comprising: a wiring body having a conductive linear body; and a pair of electrodes in direct contact with the conductive linear body, wherein the conductive linear body has an infrared reflectance of 0% or more and 90% or less at a wavelength of 1000 nm, and wherein a rate of change in resistance value after being left to stand for 1000 hours in a humid and hot environment at a temperature of 85°C and a relative humidity of 85% RH is 50% or less.

[0013] [2] The wiring sheet according to [1], wherein a relationship between a resistance value R of the electrode in the axial direction and a total resistance value r of the conductive linear body in the axial direction satisfies the condition expressed by the following formula (F1): r>R (F1)

[0014] [3] The wiring sheet according to [1] or [2], further comprising a resin layer that directly or indirectly supports the wiring body.

[0015] [4] The interconnection sheet according to any one of [1] to [3], wherein the maximum width of the electrode is 1 mm or more and 10 mm or less.

[0016] [5] The wiring sheet according to any one of [1] to [4], wherein the wiring body has a structure in which the conductive linear bodies are arranged at intervals.

[0017] [6] The wiring sheet according to any one of [1] to [5], wherein the wiring body is formed of only one of the conductive linear bodies.

[0018] [7] The wiring sheet according to any one of [1] to [6], wherein the conductive linear members are coated with sulfide or palladium.

[0019] [8] The wiring sheet according to any one of [1] to [7], wherein the conductive linear members are coated with silver sulfide.

[0020] According to one aspect of the present invention, it is possible to provide a wiring sheet that can suppress corrosion in a humid and hot environment while achieving blackening of conductive linear bodies compared to conventional wiring sheets.

[0021] 1 is a schematic diagram showing a wiring sheet according to an embodiment of the present invention, a cross-sectional view showing the II-II cross section of FIG. 1, and a graph showing the relationship between the rate of change in resistance value and the time period during which the wiring sheet is left in a humid and hot environment.

[0022] [Embodiments] The present invention will be described below with reference to the drawings, taking embodiments as examples. The present invention is not limited to the contents of the embodiments. Note that in the drawings, some parts are illustrated enlarged or reduced in size for ease of explanation.

[0023] [Wiring Sheet] As shown in Figures 1 and 2, the wiring sheet 100 according to this embodiment includes a wiring body 2 and a pair of electrodes 4. The wiring body 2 includes a conductive linear body 21. The pair of electrodes 4 are in direct contact with the conductive linear body 21. The conductive linear body 21 has an infrared reflectance of 0% or more and 90% or less at a wavelength of 1000 nm. Furthermore, the wiring sheet 100 exhibits a resistance change rate of 50% or less after being left for 1000 hours in a humid and hot environment at a temperature of 85°C and a relative humidity of 85% RH.

[0024] 1 and 2 , wiring sheet 100 further includes substrate 1 and resin layer 3. In wiring sheet 100, wiring body 2 has a structure in which conductive linear bodies 21 are arranged. Furthermore, resin layer 3 directly or indirectly supports wiring body 2.

[0025] The inventors speculate as follows about the reason why the wiring sheet 100 according to the present embodiment, having the above-described configuration, can blacken the conductive linear members 21 while suppressing corrosion in a humid and hot environment. By reducing the infrared reflectivity of the conductive linear members 21 used in the wiring sheet 100 to a value lower than conventional values, diffuse reflection of light from the conductive linear members 21 is suppressed, thereby realizing blackening of the conductive linear members 21. For example, blackening can be achieved when carbon-coated conductive linear members are used as the conductive linear members. However, when carbon-coated conductive linear members are used, the wiring sheet has low durability to humid and hot conditions, resulting in a significant change in the resistance value of the wiring sheet. The wiring sheet 100 has a structure in which the conductive linear members 21 are arranged at intervals. When carbon-coated conductive linear members are used as the conductive linear members of a wiring sheet having such a structure, corrosion occurs in the conductive linear members when the wiring sheet is used or stored in a humid and hot environment, resulting in a large rate of change in the resistance value of the wiring sheet. Meanwhile, in the wiring sheet 100 according to this embodiment, the conductive linear members 21 are configured so that the infrared reflectance of the conductive linear members 21 at a wavelength of 1000 nm is in the range of 0% or more and 90% or less. This allows the conductive linear members 21 to be blackened. Furthermore, the wiring sheet 100 according to this embodiment is configured so that the rate of change in resistance after being left for 1000 hours in a humid and hot environment at a temperature of 85°C and a relative humidity of 85% RH is in the range of 50% or less. This improves the corrosion resistance of the conductive linear members 21 in a humid and hot environment. As a result, the wiring sheet 100 according to this embodiment can suppress corrosion in a humid and hot environment while achieving blackening of the conductive linear members 21.

[0026] (Substrate) The substrate 1 can directly or indirectly support the wiring body 2. The substrate 1 is not necessarily provided. The substrate 1 is a member that is provided as needed. Examples of materials for the substrate 1 include resin, paper, metal, nonwoven fabric, cloth, and glass. Among these, from the viewpoint of strength or handleability, the material for the substrate 1 is preferably resin or glass. Examples of resins used for the substrate 1 include polyethylene, polypropylene, polystyrene, polycarbonate, and polyacetal.

[0027] The substrate 1 may or may not contain a colorant. The colorant allows the transmittance of visible light and near-infrared light in the wiring sheet 100 to be adjusted to a desired range. The colorant may be contained inside the substrate 1, or may be contained in a coating layer (not shown) provided on the outside of the substrate 1. The coating layer is a layer that is provided as needed.

[0028] When the wiring sheet 100 includes a covering layer (not shown) on the outside of the substrate 1, the covering layer is provided on at least one surface of the substrate 1. That is, the covering layer may be provided, for example, on the surface of the substrate 1 on which the pair of electrodes 4 are provided, or on the surface of the substrate 1 opposite the side on which the pair of electrodes 4 are provided. The covering layer may be provided in direct contact with the substrate 1. When the covering layer is provided on the surface of the substrate 1 on which the pair of electrodes 4 are provided, the pair of electrodes 4 may be provided in direct contact with the covering layer.

[0029] When the substrate 1 has a coating layer, the coating layer preferably has a visible light transmittance of 10% or less in the wavelength range of 380 nm to 700 nm. The visible light transmittance of the coating layer in the wavelength range of 380 nm to 700 nm is more preferably 8% or less, and even more preferably 6% or less. The hue of the coating layer is not particularly limited as long as the visible light transmittance in the wavelength range of 380 nm to 700 nm can be adjusted to 10% or less. The coating layer is preferably colored, for example, black. Black may be any hue that is generally recognized as black. When the coating layer is colored black, for example, it may be colored black with an infrared-transmitting ink containing one type of colorant, with an infrared-transmitting ink containing two or more types of colorants, or with multiple infrared-transmitting inks of different colors. It is preferable that the visible light transmittance of the coating layer in the wavelength range of 380 nm to 700 nm be such that the maximum visible light transmittance in that wavelength range is within the above range.

[0030] The coating layer preferably has a desired infrared transmittance and a refractive index above a certain level, for example, to facilitate application in optical sensing technology. The refractive index of the coating layer at a wavelength of 905 nm is preferably 1.65 or higher, more preferably 1.75 or higher, and even more preferably 1.85 or higher. A refractive index of 1.65 or higher makes the wiring sheet 100 more suitable for use as a component for optical sensors used in optical sensing technology. The upper limit of the refractive index of the coating layer at a wavelength of 905 nm is not particularly limited, and is preferably 3.00 or lower, more preferably 2.70 or lower, and even more preferably 2.40 or lower.

[0031] The coating layer preferably contains an infrared-transparent ink. The coating layer preferably has a transmittance of 70% or more for near-infrared rays with wavelengths of 905 nm to 1000 nm. The infrared-transparent ink is an ink that transmits near-infrared rays in the wavelength range of 905 nm to 1000 nm, while suppressing the transmission of visible light and ultraviolet rays. The infrared-transparent ink can transmit, for example, 70% or more for near-infrared rays in the wavelength range of 905 nm to 1000 nm. The transmittance of near-infrared rays with wavelengths of 905 nm to 1000 nm through the coating layer containing the infrared-transparent ink is more preferably 75% or more, even more preferably 80% or more, and even more preferably 85% or more. The transmittance of near-infrared rays with wavelengths of 905 nm to 1000 nm through the coating layer containing the infrared-transparent ink may be less than 100%, or may be 99% or less, or may be 95% or less. If the infrared-transmitting ink is contained in the coating layer and the transmittance of the coating layer for near-infrared rays with wavelengths of 905 nm to 1000 nm is 70% or more, the wiring sheet 100 can be easily used as a component for an optical sensor, for example. Note that the transmittance of the coating layer for near-infrared rays with wavelengths of 905 nm to 1000 nm is preferably such that the minimum value of the near-infrared transmittance in that wavelength range is within the above range.

[0032] The infrared transparent ink contains, for example, a colorant and a resin component. The infrared transparent ink preferably contains additives as needed. The colorant may contain at least one of a dye and a colored pigment. The colorant preferably contains a colored pigment. The colored pigment is not particularly limited, and examples thereof include inorganic pigments and organic pigments, which can be used alone or in combination. The inorganic pigment is not particularly limited, and examples thereof include bismuth sulfide, carbon black, red iron oxide, cadmium red, Prussian blue, and ultramarine blue, and these can be used alone or in combination. The organic pigment is not particularly limited, and examples thereof include lactam black pigments, perylene pigments, phthalocyanine pigments, benzofuranone pigments, azo pigments, anthraquinone pigments, indanthrene pigments, isoindolinone pigments, quinacridone pigments, quinophthalone pigments, diketopyrrolopyrrole pigments, dioxazine pigments, and thioindigo pigments, and these can be used alone or in combination. Among these, the color pigment is preferably an organic pigment, and from the viewpoint of making it easier to sharpen the image of the object obtained by irradiating the object with laser light, it is preferable to include at least one pigment selected from the group consisting of perylene pigments and phthalocyanine pigments, which can be set to have a low refractive index and can suppress light scattering. Furthermore, by including at least one pigment selected from the group consisting of perylene pigments and phthalocyanine pigments in the infrared transparent ink, it is easy to obtain infrared transparency while suppressing the visible light transmittance of the coating layer.

[0033] The perylene pigment is not particularly limited as long as it is an organic pigment having a perylene skeleton. For example, the perylene pigment has a structure in which two oxygen atoms constituting a six-membered ring of perylene tetracarboxylic dianhydride are eliminated. Specific examples of the perylene pigment include perylene red, perylene violet, and perylene black. The perylene pigments can be used alone or in combination of two or more.

[0034] The phthalocyanine pigment is not particularly limited as long as it is an organic pigment having a phthalocyanine skeleton. The phthalocyanine pigment has, for example, a cyclic structure in which four phthalic acid imides are bridged by nitrogen atoms. The phthalocyanine pigment may have a coordinated metal. Examples of the coordinated metal include copper, magnesium, titanium, iron, cobalt, nickel, zinc, and aluminum. When the phthalocyanine pigment contains a coordinated metal, the phthalocyanine pigment may be a copper phthalocyanine pigment in which copper is coordinated. Specific examples of the phthalocyanine pigment include phthalocyanine blue and phthalocyanine green. The phthalocyanine pigments can be used alone or in combination of two or more.

[0035] The resin component is not particularly limited, and examples thereof include various resins such as acrylic resins, vinyl chloride resins, butyral resins, polyester resins, polyurethane resins, cellulose resins, and epoxy resins, and these can be used alone or in combination of two or more. The resin component preferably includes an acrylic resin. It is also preferable that the resin component is an acrylic resin.

[0036] The infrared transmissive ink may contain, as needed, at least one additive such as a surfactant, a surface conditioner, an antifoaming agent, a leveling agent, a curing accelerator, a dispersant, a light stabilizer, a flow conditioner, a polymerization inhibitor, and an oxidation polymerization inhibitor.

[0037] The thickness of the coating layer is not particularly limited. The thickness of the coating layer is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 4 μm or more. The thickness of the coating layer is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less.

[0038] The thickness of the substrate 1 is preferably 0.05 mm or more, more preferably 0.25 mm or more, even more preferably 0.5 mm or more, even more preferably 1.0 mm or more, and particularly preferably 1.5 mm or more. The thickness of the substrate 1 is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less. When the thickness of the substrate 1 is in the range of 0.05 mm or more and 10 mm or less, excellent strength and the like can be obtained.

[0039] (Wiring Body) The wiring body 2 includes a conductive linear body 21. In the wiring sheet 100, the wiring body 2 has a structure in which the conductive linear bodies 21 are arranged. Furthermore, in the wiring sheet 100, the wiring body 2 has a structure in which a plurality of the conductive linear bodies 21 are arranged in parallel. In the wiring sheet 100, the wiring body 2 has a structure in which the plurality of conductive linear bodies 21 are arranged at intervals from one another. However, the wiring sheet 100 according to the present embodiment is a preferred example, and is not limited to this. The wiring body 2 does not necessarily have a structure in which a plurality of the conductive linear bodies 21 are arranged at intervals from one another. The wiring body 2 may have a structure consisting of only one conductive linear body 21. When the wiring body 2 is composed of one conductive linear body 21, the wiring body 2 may have a pattern in which the single conductive linear body 21 has at least one bent portion.

[0040] In the wiring sheet 100, the conductive linear body 21 is linear in a plan view of the wiring sheet 100. However, the conductive linear body 21 may be wavy in a plan view of the wiring sheet 100. Examples of the wavy shape include a sine wave, a rectangular wave, a triangular wave, and a sawtooth wave. For example, if the wiring body 2 has such a wavy shape, breakage of the conductive linear body 21 can be suppressed when the wiring sheet 100 is stretched in the axial direction of the conductive linear body 21.

[0041] The volume resistivity of the conductive linear body 21 is 1.0×10 －９ It is preferable that the resistance is Ω·m or more, and 3.0×10 －９ More preferably, it is 1.0×10 －８It is more preferable that the volume resistivity of the conductive linear body 21 is 1.0×10 －３ It is preferably Ω·m or less, and 1.0×10 －４ More preferably, it is 5.0×10 Ω·m or less. －５ It is more preferable that the volume resistivity is Ω·m or less. When the volume resistivity of the conductive linear body 21 is in the above range, the surface resistance of the wiring body 2 is likely to decrease. The volume resistivity of the conductive linear body 21 is measured as follows. Silver paste is applied to the end of the conductive linear body 21 and a portion 40 mm from the end, and the resistance of the end and a portion 40 mm from the end is measured. Then, the cross-sectional area (unit: m ２ ) by the resistance value, and the obtained value is divided by the measured length (0.04 m) to calculate the volume resistivity of the conductive linear body 21.

[0042] The cross-sectional shape of the conductive linear body 21 is not particularly limited and may be polygonal, flat, elliptical, circular, etc. From the viewpoint of compatibility with the resin layer 3, the cross-sectional shape of the conductive linear body 21 is preferably elliptical or circular.

[0043] When the cross section of the conductive linear body 21 is circular, the diameter D (see FIG. 2 ) of the conductive linear body 21 is preferably 3 μm or more and 200 μm or less. From the viewpoints of suppressing an increase in sheet resistance and improving the heat generation efficiency and dielectric breakdown resistance characteristics of the wiring sheet 100, the diameter D of the conductive linear body 21 is more preferably 4 μm or more, and even more preferably 5 μm or more. The diameter D of the conductive linear body 21 is more preferably 150 μm or less, even more preferably 100 μm or less, even more preferably 50 μm or less, and even more preferably 20 μm or less. When the cross section of the conductive linear body 21 is elliptical, the major axis is preferably in the same range as the diameter D described above.

[0044] The diameter D of the conductive linear body 21 is determined by observing the conductive linear body 21 using a digital microscope, measuring the diameter of the conductive linear body 21 at five randomly selected points, and averaging the measured values.

[0045] When the wiring body 2 has a structure in which a plurality of conductive linear bodies 21 are arranged at intervals from one another, the interval L (see FIG. 2 ) between the conductive linear bodies 21 is preferably 0.3 mm or more, more preferably 0.5 mm or more, even more preferably 0.8 mm or more, and particularly preferably 1.5 mm or more. Furthermore, the interval L between the conductive linear bodies 21 is preferably 50 mm or less, more preferably 30 mm or less, even more preferably 20 mm or less, and particularly preferably 5 mm or less. When the interval between the conductive linear bodies 21 is within the above range, the conductive linear bodies 21 are relatively densely packed, thereby improving the functionality of the wiring sheet 100, such as maintaining low resistance of the wiring body 2.

[0046] The interval L between the conductive linear bodies 21 is measured by, for example, observing the conductive linear bodies 21 of the wiring body 2 using a digital microscope and measuring the interval between two adjacent conductive linear bodies 21. Note that the interval between 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 opposing portions of the two conductive linear bodies 21 (see FIG. 2 ). When the conductive linear bodies 21 are arranged at uneven intervals, the interval L is the average value of the intervals between all adjacent conductive linear bodies 21.

[0047] The form of the conductive linear body 21 is not particularly limited as long as it satisfies both of the following conditions (a) and (b): Condition (a) The conductive linear body 21 has an infrared reflectance of 0% or more and 90% or less at a wavelength of 1000 nm, and Condition (b) The rate of change in resistance of the wiring sheet 100 after being left for 1000 hours in a humid and hot environment at a temperature of 85°C and a relative humidity of 85% RH is 50% or less.

[0048] The conductive linear body 21 can be fabricated by, for example, etching, screen printing, inkjet printing, or the like. The conductive linear body 21 may be a linear body including a metal wire (hereinafter also referred to as a "metal wire linear body"). Metal wire has high thermal conductivity, high electrical conductivity, and easy handling. Metal wire linear bodies can significantly reduce resistance, and even if the diameter of the metal wire linear body is extremely small, it can still pass a current required to heat the wiring sheet 100. This makes the conductive linear body 21 less visible. In other words, using a metal wire linear body as the conductive linear body 21 can reduce the resistance value of the wiring body 2 while improving light transmittance. Furthermore, the wiring sheet 100 can easily generate heat quickly. Furthermore, as described above, it is easy to obtain linear bodies with a small diameter.

[0049] The metal wire linear body may be a linear body consisting of a single metal wire or a linear body consisting of multiple twisted metal wires. Examples of the metal wire include wires containing metals such as copper, aluminum, tungsten, iron, molybdenum, nickel, titanium, silver, and gold, or alloys containing two or more metals such as stainless steel, carbon steel, brass, phosphor bronze, zirconium-copper alloy, beryllium copper, iron-nickel, nichrome, nickel-titanium, Kanthal, Hastelloy, and rhenium-tungsten. In particular, wires containing one or more metals selected from tungsten and molybdenum, and alloys containing these metals, are preferred from the viewpoint of low volume resistivity.

[0050] From the viewpoints of achieving blackening of the conductive linear body 21 and suppressing corrosion of the wiring sheet 100 in a humid and hot environment, the conductive linear body 21 is preferably a linear body coated with sulfide or palladium. In this specification, a coating with sulfide may be referred to as a sulfide coating, and a coating with palladium may be referred to as a palladium coating. The sulfide- or palladium-coated linear body may be (i) a linear body directly coated with sulfide or palladium, (ii) a linear body coated with sulfide or palladium via a coating of a material other than sulfide or a material other than palladium, or (iii) a linear body coated with a mixture of sulfide and a material other than sulfide, or a mixture of palladium and a material other than palladium. Examples of materials other than palladium include metals other than palladium, such as metal oxides. For example, when the linear body coated with palladium is a metal wire, the metal wire may be directly coated with palladium alone, the metal wire may be coated with palladium alone via a coating of a metal other than palladium or a metal oxide, or the metal wire may be coated with a mixture of palladium and a metal other than palladium or a metal oxide. From the viewpoint of further achieving blackening of the conductive linear body 21 and further suppressing corrosion of the wiring sheet 100 in a humid and hot environment, the conductive linear body 21 is preferably coated with silver sulfide. It is also preferable that the conductive linear body 21 be coated with a mixture of palladium and a metal other than palladium or a metal oxide. If the conductive linear body 21 is coated with sulfide or palladium, the metallic luster is reduced, making it easier to make the metal wire less noticeable. Furthermore, if the metal wire is coated with sulfide or palladium, metal corrosion is also likely to be suppressed, and therefore both of the above conditions (a) and (b) are likely to be satisfied. When the conductive linear body 21 is provided with a sulfide coating or a palladium coating, the sulfide coating or the palladium coating on the linear body can be formed by, for example, the above-mentioned plating, vapor deposition method, or the like.The conductive linear body 21 may be, for example, a sulfide-plated linear body or a palladium-plated linear body. Among these, the conductive linear body 21 is preferably a silver sulfide-plated linear body. The conductive linear body 21 is also preferably a linear body plated with a mixture of palladium and a metal or metal oxide other than palladium. The metal or metal oxide to be mixed with palladium is not particularly limited, and examples thereof include one or more selected from the group consisting of copper, silver, and oxides of these metals.

[0051] The infrared reflectance of the conductive linear body 21 at a wavelength of 1000 nm is 0% or more and 90% or less. From the viewpoint of blackening of the conductive linear body 21, the infrared reflectance at a wavelength of 1000 nm is preferably 86% or less, more preferably 78% or less, more preferably 74% or less, even more preferably 50% or less, still more preferably 35% or less, and even more preferably 30% or less. From the same viewpoint, the infrared reflectance of the conductive linear body 21 at a wavelength of 1000 nm may be 1% or more, 3% or more, 6% or more, 8% or more, or 10% or more.

[0052] The infrared reflectance of the conductive linear body 21 at a wavelength of 1000 nm can be measured by the method described in the Examples below.

[0053] (Resin Layer) The resin layer 3 directly or indirectly supports the wiring body 2. The resin layer 3 is not necessarily provided. The resin layer 3 is a component that is provided as needed. The resin layer 3 can stabilize the resistance value of the wiring body 2. That is, the resin layer 3 can fix the conductive linear body 21, stabilize the contact between the conductive linear body 21 and the electrode 4, and make it less likely that an increase in resistance value will occur.

[0054] The thickness of the resin layer 3 is not particularly limited. The thickness of the resin layer 3 may be equal to or greater than the diameter D of the conductive linear body 21, or may be less than the diameter D of the conductive linear body 21. When the thickness of the resin layer 3 is equal to or greater than the diameter D of the conductive linear body 21, the wiring body 2 can be contained within the resin layer 3. When the thickness of the resin layer 3 is less than the diameter D of the conductive linear body 21, the wiring body 2 is exposed from the resin layer 3. Furthermore, when the wiring body 2 is exposed from the resin layer 3, the wiring body 2 may be exposed on the side of the substrate 1 or on the opposite side of the substrate 1. The thickness of the resin layer 3 is preferably 1 μm or greater, more preferably 3 μm or greater, and even more preferably 5 μm or greater. The thickness of the resin layer 3 is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less.

[0055] From the viewpoint of increasing the storage modulus, the resin layer 3 is preferably a layer made of a cured product of a curable adhesive. Examples of the curable adhesive include a thermosetting adhesive that cures with heat and an energy ray-curable adhesive. Examples of the energy ray include ultraviolet light, visible energy rays, infrared rays, and electron beams. Note that "energy ray curing" also includes thermal curing by heating using energy rays.

[0056] The thermosetting adhesive preferably contains a thermosetting resin. The thermosetting resin is not particularly limited, and specific examples include epoxy resins, phenolic 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 of two or more. Among these, epoxy resins, phenolic resins, melamine resins, urea resins, amine-based compounds, and acid anhydride-based compounds are preferred as thermosetting resins, as they are suitable for curing using an imidazole-based curing catalyst. In particular, epoxy resins, phenolic resins, mixtures thereof, or mixtures of epoxy resins with at least one selected from the group consisting of phenolic resins, melamine resins, urea resins, amine-based compounds, and acid anhydride-based compounds are preferred, as they exhibit excellent curability. Epoxy resins are preferred.

[0057] As the epoxy resin, a cyclic epoxy resin such as an aromatic epoxy resin or an alicyclic epoxy resin is preferred from the viewpoint of increasing the storage modulus of the resin layer 3. An epoxy resin having a flexible segment such as an oxyalkylene chain tends to decrease the storage modulus of the resin layer 3.

[0058] The energy ray-curable adhesive preferably contains an energy ray-curable resin, such as a compound having at least one polymerizable double bond in the molecule, and preferably an acrylate compound having a (meth)acryloyl group.

[0059] Examples of the acrylate compounds include dicyclopentadiene diacrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. acrylate and other linear aliphatic skeleton-containing (meth)acrylates; cyclic aliphatic skeleton-containing (meth)acrylates such as dicyclopentanyl di(meth)acrylate; polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; oligoester (meth)acrylates, urethane (meth)acrylate oligomers, epoxy-modified (meth)acrylates, polyether (meth)acrylates other than polyalkylene glycol (meth)acrylates, and itaconic acid oligomers.

[0060] The weight average molecular weight (Mw) of the energy ray curable resin is preferably 100 or more, more preferably 300 or more. The weight average molecular weight is preferably 30,000 or less, more preferably 10,000 or less. The weight average molecular weight in this specification is a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

[0061] The adhesive may contain one or more types of energy ray-curable resins. When the adhesive contains two or more types of energy ray-curable resins, the combination and ratio thereof can be selected arbitrarily.

[0062] When an energy ray curable resin or a thermosetting resin is used, it is preferable to use a photopolymerization initiator, a thermal polymerization initiator, etc. By using a photopolymerization initiator, a thermal polymerization initiator, etc., the polymerization reaction of the curable resin can be easily initiated, and the curing reaction can be easily controlled.

[0063] Examples of the photopolymerization initiator include photoradical polymerization initiators such as benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, 2-chloroanthraquinone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide.

[0064] In addition to photoradical polymerization initiators, photocationic polymerization initiators can also be used as photopolymerization initiators. A photocationic polymerization initiator is a compound that generates cationic species when irradiated with energy rays, thereby initiating the curing reaction of a cationic curable compound, and is composed of a cationic moiety that absorbs energy rays and an anionic moiety that serves as an acid generation source.

[0065] Examples of the cationic photopolymerization initiator include sulfonium salt compounds, iodonium salt compounds, phosphonium salt compounds, ammonium salt compounds, antimonate compounds, diazonium salt compounds, selenium salt compounds, oxonium salt compounds, and bromine salt compounds. Among these, from the viewpoints of excellent compatibility and excellent storage stability of the resulting adhesive, the cationic photopolymerization initiator is preferably a sulfonium salt compound, and more preferably an aromatic sulfonium salt compound having an aromatic group.

[0066] Examples of sulfonium salt compounds include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, and triphenylsulfonium tetrakis(pentafluorophenyl)borate.

[0067] Examples of iodonium salt compounds include diphenyliodonium tetrakis(pentafluorophenyl)borate, diphenyliodonium hexafluorophosphate, and (tricumyl)iodonium tetrakis(pentafluorophenyl)borate.

[0068] Examples of the phosphonium salt compounds include tri-n-butyl(2,5-dihydroxyphenyl)phosphonium bromide and hexadecyltributylphosphonium chloride.

[0069] Examples of the ammonium salt compound include benzyltrimethylammonium chloride, phenyltributylammonium chloride, and benzyltrimethylammonium bromide.

[0070] Examples of antimonate compounds include triphenylsulfonium hexafluoroantimonate, p-(phenylthio)phenyldiphenylsulfonium hexafluoroantimonate, and diaryliodonium hexafluoroantimonate.

[0071] Examples of the thermal polymerization initiator include thermal radical polymerization initiators such as peroxodisulfates, such as hydrogen peroxide, ammonium peroxodisulfate, sodium peroxodisulfate, and potassium peroxodisulfate; azo compounds, such as 2,2'-azobis(2-amidinopropane) dihydrochloride, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobisisobutyronitrile, and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile); and organic peroxides, such as benzoyl peroxide, lauroyl peroxide, peracetic acid, persuccinic acid, di-t-butyl peroxide, t-butyl hydroperoxide, and cumene hydroperoxide.

[0072] In addition to the above-mentioned thermal radical polymerization initiators, examples of the thermal polymerization initiator include thermal cationic polymerization initiators. The thermal cationic polymerization initiator is a compound that can generate cationic species that initiate polymerization upon heating. Examples of the thermal cationic polymerization initiator include sulfonium salts, quaternary ammonium salts, phosphonium salts, diazonium salts, and iodonium salts. Among these, sulfonium salts are preferred as the thermal cationic polymerization initiator from the viewpoints of ease of availability and ease of obtaining a resin layer 3 that is more excellent in adhesion and transparency.

[0073] Examples of sulfonium salts include triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, benzyl(4-hydroxyphenyl)methylsulfonium tetrakis(pentafluorophenyl)borate, (4-hydroxyphenyl)methyl(4-methylbenzyl)sulfonium tetrakis(pentafluorophenyl)borate, and triphenylsulfonium hexafluoroarsinate.

[0074] Examples of quaternary ammonium salts include tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, and tetrabutylammonium hydrogen sulfate. Examples of phosphonium salts include ethyltriphenylphosphonium hexafluoroantimonate and tetrabutylphosphonium hexafluoroantimonate.

[0075] Examples of diazonium salts include benzenediazonium chloride, etc. Examples of iodonium salts include diphenyliodonium hexafluoroarsinate, bis(4-chlorophenyl)iodonium hexafluoroarsinate, bis(4-bromophenyl)iodonium hexafluoroarsinate, and phenyl(4-methoxyphenyl)iodonium hexafluoroarsinate, etc.

[0076] These polymerization initiators can be used alone or in combination of two or more. When these polymerization initiators are used to form a crosslinked structure, the amount used is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 0.3 parts by mass or more and 20 parts by mass or less, and particularly preferably 0.5 parts 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.

[0077] When a thermosetting resin is used, a curing catalyst such as an imidazole-based curing catalyst may be used.

[0078] In this embodiment, the curable adhesive may contain a flexibility-adjusting component together with the energy ray-curable resin or the thermosetting resin to facilitate maintenance of the sheet shape before curing. Examples of polymers used as the flexibility-adjusting component include phenoxy resin, polyolefin resin or modified polyolefin resin, polyamide-imide resin, polyimide resin, rubber-based resin, and acrylic resin.

[0079] These flexibility-adjusting components may be used alone or in combination of two or more.

[0080] When the curable adhesive used in this embodiment contains a flexibility-adjusting component, the total amount of the energy ray-curable resin or thermosetting resin contained in the adhesive is preferably 15 parts by mass or more and 300 parts by mass or less, more preferably 30 parts by mass or more and 250 parts by mass or less, and even more preferably 60 parts by mass or more and 200 parts by mass or less, relative to 100 parts by mass of the flexibility-adjusting component, from the viewpoint of adjusting the storage modulus of the resin layer 3. Furthermore, when the adhesive contains an energy ray-curable resin or a thermosetting resin but does not contain a flexibility-adjusting component, the storage modulus of the resin layer 3 tends to be too high.

[0081] In this embodiment, the curable adhesive may or may not contain a filler. From the viewpoint of increasing the storage modulus of the resin layer 3 at 23°C, the curable adhesive may contain a filler. From the viewpoint of suppressing an increase in the storage modulus of the resin layer 3 at 23°C, the curable adhesive may not contain a filler.

[0082] Examples of fillers include inorganic powders such as silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride; beads obtained by spheroidizing inorganic powders, single-crystal fibers, and glass fibers. Among these, silica filler and alumina filler are preferred. The fillers may be used alone or in combination of two or more.

[0083] The curable adhesive may contain other components, such as well-known additives, such as organic solvents, coupling agents, flame retardants, tackifiers, UV absorbers, antioxidants, preservatives, antifungal agents, plasticizers, antifoaming agents, and wettability adjusters.

[0084] (Electrodes) The electrodes 4 are used to supply current to the conductive linear body 21. The electrodes 4 are in pair. The electrodes 4 are in direct contact with the conductive linear body 21. The electrodes 4 are arranged so as to be electrically connected to both ends of the conductive linear body 21.

[0085] The relationship between the resistance value R of the electrode 4 in the axial direction and the overall resistance value r of the conductive linear body 21 in the axial direction preferably satisfies the condition expressed by the following formula (F1). When the condition expressed by the following formula (F1) is satisfied, heat generation of the electrode 4 can be reduced. r>R (F1)

[0086] The value of R / r is preferably 0.0001 or more, and more preferably 0.0005 or more. Furthermore, R / r is preferably 0.3 or less, and more preferably 0.15 or less. When wiring sheet 100 is used as a heating element, wiring body 2 needs to have a certain degree of resistance in order to generate heat, while electrode 4 preferably allows current to flow as easily as possible.

[0087] The resistance value R in the axial direction of the electrode 4 and the overall resistance value r in the axial direction of the conductive linear body 21 can be measured using a tester. First, the resistance value R in the axial direction of the electrode 4 and the resistance value (per fiber) in the axial direction of the conductive linear body 21 are measured. Since the resistance value in the axial direction of the conductive linear body 21 is inversely proportional to the cross-sectional area of ​​the conductive linear body 21, the overall resistance value r in the axial direction of the conductive linear body 21 is calculated by dividing the resistance value (per fiber) in the axial direction of the conductive linear body 21 by the number of conductive linear bodies 21.

[0088] The Young's modulus of the electrode 4 is 1×10 ９ Pa super, 1×10 １１ The Young's modulus of the electrode 4 is preferably 1×10 Pa or less. １１ If the Young's modulus of the electrode 4 is 8.5×10 Pa or less, the contact resistance between the conductive linear body 21 and the electrode 4 tends to be smaller. １０ Pa or less, and more preferably 7×10 １０ The Young's modulus of the electrode 4 is preferably 2×10 Pa or less. ９ Pa or more, and ９ Pa or more, and ９ It may be Pa or more.

[0089] The Young's modulus of the electrode 4 can be measured by a continuous stiffness measurement method. For example, the Young's modulus of the electrode 4 provided on a glass substrate at 25°C can be measured using a nanoindenter (manufactured by MTS Systems) under the following conditions: indenter shape: triangular pyramid; maximum indenter depth: 500 nm; vibration frequency: 75 Hz

[0090] The maximum thickness of the electrode 4 is preferably 40 μm or less. The maximum thickness of the electrode 4 is more preferably 30 μm or less, and even more preferably 20 μm or less. If the maximum thickness of the electrode 4 is 40 μm or less, deformation of the conductive linear body 21 tends to be small when the conductive linear body 21 and the electrode 4 are brought into contact, and conduction tends to be more stable. The maximum thickness of the electrode 4 is preferably 5 μm or more, more preferably 8 μm or more, and even more preferably 10 μm or more.

[0091] In a plan view of the wiring sheet 100, the maximum width of the electrode 4 is preferably 1 mm or more and 10 mm or less. The maximum width of one of the electrodes 4 is preferably within the above range. The maximum width of the electrode 4 is more preferably 1.5 mm or more, and even more preferably 2 mm or more. The maximum width of the electrode 4 is more preferably 8 mm or less, even more preferably 6 mm or less, and even more preferably 4 mm or less. When the maximum width of the electrode 4 is 1 mm or more and 10 mm or less in a plan view of the wiring sheet 100, it is easy to ensure a contact point with the conductive linear member 21.

[0092] The electrode 4 can be formed using a known electrode material, such as a conductive paste, a metal foil, or a metal wire.

[0093] Examples of the conductive paste include silver paste, copper paste, and carbon paste. Among these, the conductive paste is preferably silver paste from the viewpoint of low volume resistivity.

[0094] When the electrode material is a metal foil or metal wire, examples of the metal foil or metal wire include copper, aluminum, tungsten, iron, molybdenum, nickel, titanium, silver, and gold; or alloys containing two or more metals, such as stainless steel, carbon steel, brass, phosphor bronze, zirconium-copper alloy, beryllium copper, iron-nickel, nichrome, nickel-titanium, Kanthal, Hastelloy, and rhenium-tungsten. The metal foil or metal wire may be plated with gold, tin, zinc, silver, nickel, chromium, nickel-chromium alloy, solder, or the like. When the electrode material is a metal wire, the metal wire may be one or more.

[0095] The electrode 4 is preferably gold-plated, which can suppress migration of the electrode 4.

[0096] (Uses of wiring sheet, etc.) The wiring sheet 100 according to the present embodiment can be suitably used, for example, as a sheet heater. In this case, examples of uses of the sheet heater include a window defogger and a defroster. In addition to use as a sheet heater, the wiring sheet 100 can also be used as a flat cable for wiring electrical signals. The wiring sheet 100 according to the present embodiment can also be used as a heater for an optical sensor. In this case, the heater for the optical sensor can be used, for example, as a heater for an optical sensor such as a LiDAR sensor.

[0097] The rate of change in resistance when the wiring sheet 100 is used or stored in a humid and hot environment at a temperature of 85°C and a relative humidity of 85% RH is preferably 20% or less, more preferably 18% or less, even more preferably 17% or less, even more preferably 15% or less, and even more preferably 13% or less. The rate of change in resistance when the wiring sheet 100 is used or stored in a humid and hot environment at a temperature of 85°C and a relative humidity of 85% RH is preferably 0% or close to 0%. The rate of change in resistance when the wiring sheet 100 is used or stored in a humid and hot environment may be 0% or more, or even 0.1% or more. A rate of change in resistance of 20% or less suppresses corrosion of the wiring sheet even when the wiring sheet is used or stored in a humid and hot environment. Furthermore, the wiring sheet can be used or stored in a humid and hot environment. The rate of change in resistance can be measured by the method described in the Examples below. Here, the time period during which the wiring sheet 100 is used or stored in the above-mentioned humid and hot environment is 1,000 hours. The rate of change in resistance value may be less than 0%. Furthermore, the rate of change in resistance value is preferably 0% or more and 20% or less, in terms of the absolute value of the rate of change in resistance value before and after wiring sheet 100 is used or stored in a humid and hot environment at a temperature of 85° C. and a relative humidity of 85% RH.

[0098] [Method for Manufacturing Interconnect Sheet] Next, a method for manufacturing the interconnect sheet 100 according to this embodiment will be described. The method for manufacturing the interconnect sheet 100 according to this embodiment is not particularly limited. The method for manufacturing the interconnect sheet 100 according to this embodiment is one example of a method that can produce the interconnect sheet 100 described above. The interconnect sheet 100 can be manufactured, for example, by the following steps.

[0099] First, a process for preparing a wiring sheet including wiring body 2 is performed. In this process, resin layer 3 is formed on a release sheet. When resin layer 3 is formed using a thermosetting adhesive, the thermosetting adhesive for forming resin layer 3 is applied to form a coating film. Next, the coating film is dried to prepare an adhesive layer as resin layer 3. Next, conductive linear bodies 21 are arranged and placed on the adhesive layer to form wiring body 2. For example, with the adhesive layer with a release sheet placed on the outer circumferential surface of a drum member, conductive linear bodies 21 are spirally wound around the adhesive layer while rotating the drum member. Then, the bundle of spirally wound conductive linear bodies 21 is cut along the axial direction of the drum member. This forms wiring body 2, which is then placed on the adhesive layer. In this manner, a wiring body sheet in which wiring body 2 is formed on an adhesive layer with a release sheet is obtained. According to this method, for example, by rotating the drum member and moving the payout portion of the conductive linear body 21 along a direction parallel to the axis of the drum member, it is easy to adjust the distance L between adjacent conductive linear bodies 21 in the wiring body 2.

[0100] Next, a step of providing a pair of electrodes 4 on the substrate 1 is performed. In this step, for example, a conductive paste or the like is printed in a predetermined arrangement on the substrate 1, and then dried, whereby the pair of electrodes 4 can be provided.

[0101] Next, a step is performed in which the wiring sheet prepared above is placed on the substrate 1 provided with the pair of electrodes 4, and the thermosetting adhesive is cured. In this step, the wiring sheet is attached to the substrate 1 provided with the pair of electrodes 4 so that the pair of electrodes 4 contact both ends of the conductive linear members 21 in the wiring 2 of the wiring sheet. Then, after peeling off the release sheet, the thermosetting adhesive is subjected to a predetermined heat treatment to form the resin layer 3, and the wiring sheet 100 is prepared.

[0102] [Effects of the Embodiment] The present embodiment can achieve the following effects. (1) The present embodiment can suppress changes in the resistance value of the wiring sheet 100 even when used or stored in a humid and hot environment (e.g., an environment at a temperature of 85°C and a relative humidity of 85% RH). (2) The present embodiment can blacken the conductive linear members 21 by setting the infrared reflectance at a wavelength of 1000 nm of the conductive linear members 21 to a range of 0% to 90%. This makes it possible to impart design features to the wiring sheet 100, for example. Furthermore, the wiring sheet 100 can be used as a heater for an optical sensor, for example. (3) The present embodiment can fix the conductive linear members 21 using the resin layer 3, suppress deformation in the thickness direction inside the wiring sheet 100, stabilize contact between the conductive linear members 21 and the electrodes 4, and stabilize the resistance value of the wiring member 2.

[0103] [Modifications of the Embodiments] The present invention is not limited to the above-described embodiments, and modifications or improvements within the scope of achieving the object of the present invention are included in the present invention. For example, in the above-described embodiments, the wiring sheet 100 includes a substrate 1, but this is not limiting. For example, the wiring sheet 100 does not necessarily include a substrate 1. In such cases, the wiring sheet 100 can be used by being attached to an adherend using the resin layer 3. Furthermore, in the above-described embodiments, the resin layer 3 is disposed on the surface of the wiring sheet 100, but this is not limiting. For example, a protective sheet (not shown) may be provided on the resin layer 3 of the wiring sheet 100 to protect the wiring body 2.

[0104] The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples. Unless otherwise specified, the blending ratios expressed in parts by mass are the ratios of solid content. The wiring sheets obtained in the examples were evaluated as follows.

[0105] [Reflectance Evaluation] A tungsten plate having the same composition as the wire used in each Example and Comparative Example was plated with silver sulfide, palladium, copper oxide-palladium, or gold, each having the same composition as the plating layer used in each Example and Comparative Example 2, or with a carbon coating having the same composition as the coating layer used in Comparative Example 1, to form a plating layer or coating layer of the respective material on the tungsten plate. The plating layer or coating layer was formed by the same method as for the plated tungsten wire or carbon-coated tungsten wire used in each Example and Comparative Example. For a tungsten plate having a silver sulfide-plated layer, a tungsten plate having a palladium-plated layer, a tungsten plate having a copper oxide-palladium-plated layer, a tungsten plate having a gold-plated layer, or a tungsten plate having a carbon-coated layer, the infrared reflectance of each of the plating layers or coating layers was measured at a wavelength of 1000 nm using an ultraviolet-visible-near-infrared spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-VIS-NIR SPECTROPHOTOMETER UV-3600").

[0106] [Evaluation of Resistance Value] A resistance meter (manufactured by Hioki E.E. Corporation, product name "RM3545") was connected to the electrodes, and the resistance value (R １ After the wiring sheet was left standing for 1000 hours in a humid and hot environment at a temperature of 85°C and a relative humidity of 85% RH, a resistance meter was connected to the electrodes, and the resistance value (R ２ ) was measured. Then, R １ and R ２ The resistance change rate (unit: %) was calculated. The smaller this resistance change rate, the more the change in the resistance of the wiring sheet is suppressed. Resistance change rate = [(R ２ -R １ ) / R １ ]×100(%) ...(F2)

[0107] [Appearance Evaluation] The wiring sheets obtained in each Example and Comparative Example were placed on a black board and visually inspected. In Table 1, cases in which the conductive linear bodies were not visible and the design was excellent were marked with "A," and cases in which the conductive linear bodies were visible and the design was poor were marked with "F."

[0108] Preparation Example 1 (Preparation of Curable Adhesive) A curable adhesive was obtained by blending 100 parts by mass of phenoxy resin (manufactured by Mitsubishi Chemical Corporation, product name "YX7200B35") with 170 parts by mass of a polyfunctional hydrogenated bisphenol A diglycidyl ether epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name "YX8000"), 0.2 parts by mass of 8-glycidoxyoctyltrimethoxysilane as a silane coupling agent, and 2 parts by mass of benzyl(4-hydroxyphenyl)methylsulfonium tetrakis(pentafluorophenyl)borate and 2 parts by mass of (4-hydroxyphenyl)methyl(4-methylbenzyl)sulfonium tetrakis(pentafluorophenyl)borate as thermal cationic polymerization initiators.

[0109] Preparation Example 2 (Preparation of (meth)acrylic acid ester polymer (A)) 55 parts by mass of 2-ethylhexyl acrylate, 5 parts by mass of 4-acryloylmorpholine, 15 parts by mass of isobornyl acrylate, and 25 parts by mass of 2-hydroxyethyl acrylate were copolymerized by solution polymerization to prepare a (meth)acrylic acid ester polymer (A). The molecular weight of this (meth)acrylic acid ester polymer (A) was measured by the method described above, and the weight average molecular weight (Mw) was 600,000. The glass transition temperature (Tg; ° C) of this (meth)acrylic acid ester polymer (A) was calculated using the FOX formula based on the glass transition temperatures (Tg) of the respective monomers constituting the (meth)acrylic acid ester polymer (A) as homopolymers, and was found to be −36.5 ° C.

[0110] [Preparation Example 3] (Preparation of adhesive composition) 100 parts by mass of the (meth)acrylic acid ester polymer (A) obtained in the above step, 0.18 parts by mass of trimethylolpropane-modified tolylene diisocyanate as the crosslinking agent (B), 7 parts by mass of ε-caprolactone-modified tris-(2-acryloxyethyl)isocyanurate as the active energy ray-curable component (C), 0.7 parts by mass of a mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone in a 1:1 mass ratio as the photopolymerization initiator (D), and 0.28 parts by mass of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent were mixed, thoroughly stirred, and diluted with methyl ethyl ketone to obtain a coating solution of an adhesive composition.

[0111] [Example 1] (Preparation of silver sulfide-plated tungsten wire) A sulfuration solution was prepared by adding 3.5 g of potassium sulfide to 1 L of water. A silver-plated tungsten wire (diameter 12 μm, volume resistivity 5.5×10) was added to the sulfuration solution. －８ The silver sulfide-plated tungsten wire was immersed in a solution of 0.1 μm (Ω·m) to produce a silver sulfide-plated tungsten wire. The thickness of the silver sulfide plating layer on the produced silver sulfide-plated tungsten wire was 0.1 μm. The silver sulfide-plated tungsten wire had a hue close to black.

[0112] (Preparation of Wiring Sheet) The curable adhesive obtained in Preparation Example 1 was applied to a thickness of 10 μm on a 38 μm thick release sheet (manufactured by Lintec Corporation, product name "SP-PET382150") and cut into a 250 mm x 320 mm rectangle to prepare an adhesive sheet with a curable adhesive layer (hereinafter sometimes referred to as the adhesive layer). The silver sulfide-plated tungsten wire (hereinafter sometimes referred to as the wire) prepared above was prepared as the conductive linear body. Next, the adhesive sheet obtained above was wrapped around a drum member with a rubber outer surface, with the surface of the adhesive layer facing outward, ensuring no wrinkles, and both ends of the adhesive sheet in the circumferential direction were fixed with double-sided tape. The wire wound around the bobbin was attached to the surface of the adhesive layer of the adhesive sheet located near the end of the drum member, and the wire was then unwound and wound around the drum member. The drum member was gradually moved in a direction parallel to the drum axis so that the wire was wound around the drum member in a spiral pattern at equal intervals of 3 mm. This resulted in a wiring body with 96 wires arranged on the surface of the adhesive layer. The wire was then cut and removed from the drum member. The wiring body was cut into 40 mm x 82 mm widths so that 12 wires could be removed, and a wiring body sheet was produced. The overall resistance value r in the axial direction of the conductive linear body was 4.93 Ω.

[0113] (Preparation of Substrate with Electrodes) A ​​silver paste (manufactured by Jujo Chemical Co., Ltd., product name "#2 TF Silver Paste") was screen-printed onto a 2 mm thick glass substrate with a width of 3 mm and an inter-electrode distance of 7.8 mm, and then dried at 150 ° C. for 30 minutes to form a coating film with a thickness of 12 μm, thereby preparing a substrate with electrodes. Subsequently, a nickel layer (thickness: 1 μm) and a gold layer (thickness: 50 nm) were laminated in this order on the silver paste by electroless plating, producing a substrate with electrodes (resistance value R: 0.56 Ω). The elastic modulus of the electrode was 62.6 GPa.

[0114] (Preparation of coating layer-forming composition) A visible light-absorbing infrared transparent ink (manufactured by Jujo Chemical Co., Ltd., product name "TG-IR Ink PB-A Black") was prepared as the infrared transparent ink. This infrared transparent ink contains a perylene-based pigment. 2 parts by mass of 3-aminopropyltrimethoxysilane and 5 parts by mass of trimethylolpropane adduct xylylene diisocyanate were blended with 100 parts by mass of this infrared transparent ink to obtain a coating layer-forming composition.

[0115] (Preparation of substrate with coating layer) The coating layer-forming composition prepared above was screen printed on the surface opposite to the electrode-provided surface of the electrode-provided substrate to form a coating film. The coating film was then dried under two-stage drying conditions: 10 minutes at 90 ° C., followed by 30 minutes at 150 ° C., to form a 6 μm thick coating layer on the substrate. The coating layer formed from the coating layer-forming composition was colored black, and had a maximum transmittance of 89% and a minimum of 86% for near-infrared light with a wavelength of 905 nm to 1000 nm, and a maximum transmittance of 5% and a minimum of 0% for visible light with a wavelength of 380 nm to 700 nm. The refractive index of near-infrared light with a wavelength of 905 nm was 2.10.

[0116] (Fabrication of Wiring Sheet) The wiring sheet fabricated above was attached to a substrate with electrodes so that the electrodes were located at both ends of the wires. Thereafter, the substrate was heated at a temperature of 120°C under a pressure of 0.5 MPa for 30 minutes to obtain a wiring sheet of Example 1.

[0117] (Preparation of Protective Sheet) The pressure-sensitive adhesive composition obtained in Preparation Example 3 was applied to a thickness of 100 μm on a 100 μm thick cycloolefin polymer film (manufactured by Zeon Corporation, product name "ZF16") and cut into a 50 mm × 120 mm rectangle. A circle with a diameter of 5 mm was then cut out so that the center-to-center distance between the two circles was 7.8 mm, thereby preparing a protective sheet.

[0118] (Preparation of Wiring Sheet with Protective Sheet) A protective sheet was attached to the wiring sheet so that the electrodes of the wiring sheet and the circles of the protective sheet were aligned. Then, ultraviolet light with a wavelength of 365 nm was applied at an illuminance of 200 mW / cm. ２ , light intensity 1000mJ / cm２ The wiring sheet with the protective sheet was obtained.

[0119] Example 2 In the production of a wiring sheet, a palladium-plated tungsten wire (diameter 12 μm, volume resistivity 5.5×10) was used as the conductive linear body instead of the silver sulfide-plated tungsten wire. －８ A wiring sheet with a protective sheet was produced in the same manner as in Example 1, except that a palladium-plated tungsten wire (Ω·m) was used. The palladium-plated tungsten wire has a hue close to black.

[0120] Example 3 A wiring sheet with a protective sheet was produced in the same manner as in Example 1, except that copper oxide-palladium-plated tungsten wire was used as the conductive linear body instead of the silver sulfide-plated tungsten wire. The copper oxide-palladium-plated tungsten wire has a hue close to black. The copper oxide-palladium-plated tungsten wire was produced as follows.

[0121] A copper-plated tungsten wire (diameter 12 μm, volume resistivity 4.23×10) was placed in a plating solution containing palladium ("OPC Black Copper", manufactured by Okuno Chemical Industries Co., Ltd.). －８ The wire was then immersed in a solution of 0.1 Ω·m and then treated with an anti-tarnish agent (OPC Black Keep, manufactured by Okuno Chemical Industries Co., Ltd.) to produce a copper oxide-palladium-plated tungsten wire. The copper oxide-palladium-plated tungsten wire has a plating layer containing a mixture of copper oxide and palladium on the tungsten wire. The thickness of the copper oxide-palladium plating layer on the produced copper oxide-palladium-plated tungsten wire was 0.2 μm.

[0122] Comparative Example 1 In the production of a wiring sheet, a carbon-coated tungsten wire (diameter 12 μm, volume resistivity 5.5×10) was used as the conductive linear body instead of the silver sulfide-plated tungsten wire. －８ A wiring sheet with a protective sheet was produced in the same manner as in Example 1, except that a carbon-coated tungsten wire (Ω·m) was used. The carbon-coated tungsten wire has a hue close to black.

[0123] Comparative Example 2 In the production of the wiring sheet, a gold-plated tungsten wire (diameter 12 μm, volume resistivity 5.5×10) was used as the conductive linear body instead of the silver sulfide-plated tungsten wire. －８ A wiring sheet with a protective sheet was produced in the same manner as in Example 1, except that a gold-plated tungsten wire with a resistance of 1000 Ω·m was used. The gold-plated tungsten wire is not close to black in hue.

[0124]

[0125] The wiring sheets obtained in each Example had better results in both reflectance evaluation and resistance evaluation than the wiring sheets obtained in each Comparative Example. Furthermore, each Example with a low rate of change in resistance value and low infrared reflectance had a good appearance evaluation and excellent design.

[0126] Fig. 3 shows a graph representing the relationship between time and the rate of change in resistance when the wiring sheet is left in an environment at a temperature of 85°C and a relative humidity of 85% RH. In Fig. 3, the horizontal axis represents the leaving time, and the vertical axis represents the rate of change in resistance. In Fig. 3, E represents the wiring sheet produced in Example 1, and C represents the wiring sheet produced in Comparative Example 1. As shown in Fig. 3, it can be seen that the wiring sheet produced in Example 1 has a larger rate of change in resistance over time than the wiring sheet produced in Comparative Example 1.

[0127] From the above results, it was confirmed that the wiring sheet according to this embodiment can suppress corrosion in a humid and hot environment while achieving blackening of the conductive linear members.

[0128] REFERENCE SIGNS LIST 1...substrate, 2...wiring body, 21...conductive linear body, 3...resin layer, 4...electrode, 100...wiring sheet

Claims

1. A wiring sheet comprising: a wiring body having a conductive linear body; and a pair of electrodes in direct contact with the conductive linear body, wherein the conductive linear body has an infrared reflectance of 0% or more and 90% or less at a wavelength of 1000 nm, and the rate of change in resistance after being left to stand for 1000 hours in a humid and hot environment at a temperature of 85°C and a relative humidity of 85% RH is 50% or less.

2. The wiring sheet according to claim 1, wherein the relationship between the resistance value R in the axial direction of the electrode and the overall resistance value r in the axial direction of the conductive linear body satisfies the condition expressed by the following formula (F1): r>R (F1) 3. The wiring sheet according to claim 1 or 2, further comprising a resin layer that directly or indirectly supports the wiring body.

4. The wiring sheet according to claim 1 or 2, wherein the maximum width of the electrodes is 1 mm or more and 10 mm or less.

5. A wiring sheet according to claim 1 or 2, wherein the wiring body has a structure in which the conductive linear bodies are arranged at intervals.

6. A wiring sheet according to claim 1 or 2, wherein the wiring body is made up of only one of the conductive linear bodies.

7. The wiring sheet according to claim 1 or 2, wherein the conductive linear members are coated with sulfide or palladium.

8. The wiring sheet according to claim 1 or 2, wherein the conductive linear members are coated with silver sulfide.

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