Wiring sheet

Abstract

To provide a wiring sheet having excellent blister resistance, chipping resistance, transparency and curved surface conformability.SOLUTION: A wiring sheet 100 includes a wiring body 2 having a conductive linear body 21, a pair of electrodes 4 in direct contact with the conductive linear body 21, a first resin layer 3 that directly or indirectly supports the wiring body 2, and a urethane base material 1 that directly or indirectly supports the wiring body 2, where the thickness of the urethane base material 1 is 110 μm or more, and the water vapor permeability of the urethane base material 1 is 15 g / m2 / day or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] As an example of a wiring sheet that can be used for a sheet heater, Patent Document 1 describes a conductive sheet having a pseudo-sheet structure in which multiple linear elements extending in one direction are arranged at intervals. A pair of electrodes is provided on both ends of the multiple linear elements, thereby obtaining a wiring sheet that can be used as a heating element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 086395 Summary of the Invention [Problem to be solved by the invention]

[0004] The wiring sheet described in Patent Document 1 can be suitably used as a sheet heater. However, in recent years, sheet heaters have come to be required to have multiple properties such as blister resistance, chipping resistance, transparency, and curved surface conformability.

[0005] An object of the present invention is to provide a wiring sheet that is excellent in blister resistance, chipping resistance, transparency, and curved surface conformability. [Means for solving the problem]

[0006] [1] A wiring body having a conductive linear body; a pair of electrodes in direct contact with the conductive linear body; a first resin layer that directly or indirectly supports the wiring body; a urethane base material that directly or indirectly supports the wiring body; Equipped with The thickness of the urethane base material is 110 μm or more, The water vapor permeability of the urethane base material is 15 g / m 2 / day or more, Wiring sheet.

[0007] [2] In the wiring sheet according to [1], Further, a urethane base material and a second resin layer are provided between the adherend and the wiring sheet, the urethane base material, the first resin layer, the wiring body, the electrode, the urethane base material, and the second resin layer are provided in this order in the thickness direction of the wiring sheet; Wiring sheet.

[0008] [3] In the wiring sheet according to [1] or [2], The total light transmittance of the wiring sheet is 75.0% or more. Wiring sheet.

[0009] [4] The wiring sheet according to any one of [1] to [3], The thickness of the first resin layer is 5 μm or more and 100 μm or less. Wiring sheet.

[0010] [5] The wiring sheet according to any one of [1] to [4], The storage modulus of the first resin layer at 23°C is 1.0 × 10 4 Pa or more, 5.0×10 6 Pa or less, Wiring sheet.

[0011] [6] The wiring sheet according to any one of [1] to [5], The conductive linear body has a pattern formed thereon having at least one bent portion in a plan view. Wiring sheet.

[0012] [7] In the wiring sheet according to [6], The wiring body is composed of one of the conductive linear bodies. Wiring sheet.

[0013] [8] In the wiring sheet according to [6], The wiring body includes two or more of the conductive linear bodies. Wiring sheet.

[0014] [9] The wiring sheet according to any one of [1] to [5], The wiring body has a structure in which a plurality of the conductive linear bodies are arranged at intervals. Wiring sheet. [Effects of the Invention]

[0015] According to one aspect of the present invention, a wiring sheet having excellent blister resistance, chipping resistance, transparency, and curved surface conformability can be provided. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram illustrating a wiring sheet according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing the II-II cross section of FIG. [Figure 3] FIG. 2 is a cross-sectional view showing the cross section III-III of FIG. [Figure 4] 10A and 10B are schematic diagrams showing modified aspects of the wiring body in the embodiment of the present invention. [Figure 5] 1 is a cross-sectional view showing an example of use of a wiring sheet according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] [Embodiment] The present invention will be described below with reference to the drawings, taking an embodiment as an example. The present invention is not limited to the content of the embodiment. In the drawings, some parts are illustrated enlarged or reduced in size for ease of explanation.

[0018] [Wiring sheet] As shown in Figures 1, 2, and 3, the wiring sheet 100 of this embodiment comprises a urethane base material 1, a wiring body 2, a first resin layer 3, a pair of electrodes 4, and a second resin layer 5. The wiring body 2 includes a conductive linear body 21 in which a pattern having at least one bent portion 211 is formed in a plan view. The first resin layer 3 directly or indirectly supports the wiring body 2. As shown in FIG. 2, the electrodes 4 are provided on the first resin layer 3 and are in direct contact with the conductive linear body 21. The pair of electrodes 4 can be electrically connected to a power source (not shown). As shown in Fig. 2, the wiring sheet 100 preferably comprises a urethane base material 1, a first resin layer 3, conductive linear members 21, electrodes 4, and a second resin layer 5 in this order. The wiring sheet 100 can be used by being attached to an adherend (not shown) via the second resin layer 5 or a separate pressure-sensitive adhesive layer (not shown). The adherend may also have a curved surface.

[0019] In this embodiment, the thickness of the urethane substrate 1 is 110 μm or more, and the water vapor permeability of the urethane substrate 1 is 15 g / m 2 / day or more. The water vapor transmission rate can be measured by the method described in the examples below. The reasons why wiring sheet 100 according to this embodiment has excellent blister resistance, chipping resistance, transparency, and curved surface conformability are as follows. That is, wiring sheet 100 is used by being attached to an adherend, and as a result, urethane substrate 1 covers the surface of wiring body 2, thereby protecting wiring body 2. Note that in conventional wiring sheets, the technical idea of ​​protecting wiring body 2 with a substrate has not been to protect wiring body 2, but rather to protect wiring body 2 with a separate protective film or the like. Furthermore, by using urethane as the substrate material and further setting the thickness and water vapor permeability of urethane substrate 1 to be equal to or greater than predetermined values, wiring sheet 100 is endowed with blister resistance, chipping resistance, and curved surface conformability. Furthermore, urethane substrate 1 has excellent transparency, so the transparency of wiring sheet 100 is not reduced.

[0020] In this embodiment, from the viewpoint of transparency, the total light transmittance of wiring sheet 100 is preferably 75.0% or more, more preferably 85.0% or more, and even more preferably 90.0% or more. The total light transmittance of wiring sheet 100 may be less than 100%. In this embodiment, from the viewpoint of transparency, the haze of interconnect sheet 100 is preferably 5.0 or less, more preferably 3.0 or less, and even more preferably 1.0 or less. The haze of interconnect sheet 100 may be 0.1 or more. The total light transmittance and haze can be measured by the method described in the examples below.

[0021] (urethane base material) The urethane base material 1 can directly or indirectly support the wiring body 2. Furthermore, the urethane base material 1 can protect the wiring body 2. The material of the urethane base material 1 is polyurethane, which is a material with excellent flexibility and transparency.

[0022] The water vapor permeability of the urethane substrate 1 is 15 g / m 2 / day or more. The water vapor transmission rate must be 15g / m 2 If the permeability is less than 1000 kJ / day, the blister resistance of wiring sheet 100 may be insufficient. From the same viewpoint, the water vapor transmission rate of urethane base material 1 is set to 50 g / m 2 / day or more is preferable, and 150 g / m 2 / day or more is more preferable, and 200g / m 2 / day or more. The water vapor transmission rate of the urethane substrate 1 is preferably 10,000 g / m 2 / day or less, and 5000g / m 2 / day or less, and 2000g / m 2 The water vapor transmission rate can be measured by the method described in the examples below.

[0023] The thickness of the urethane substrate 1 must be 110 μm or more. If the thickness is less than 110 μm, the chipping resistance of the wiring sheet 100 may be insufficient. From the same viewpoint, the thickness of the urethane substrate 1 is preferably 130 μm or more, and more preferably 150 μm or more. The thickness of the urethane substrate 1 is preferably 10 mm or less, more preferably 1 mm or less, and even more preferably 300 μm or less. When the thickness of the urethane substrate 1 is within the above range, excellent strength and the like can be obtained.

[0024] (Wiring body) The wiring body 2 preferably includes a conductive linear body 21 having a pattern with at least one bent portion 211 formed thereon in a plan view. In the present embodiment, the wiring body 2 preferably includes a single conductive linear body 21, as shown in FIG. 1 . Furthermore, the wiring body 2 preferably has a pattern that can be drawn in a single stroke in a plan view. In such a case, the contact portion between the wiring body 2 and the electrode 4 is sufficient at both ends of the single conductive linear body 21, and therefore the area of ​​the electrode 4 can be reduced. This also improves the ability of the wiring sheet 100 to conform to curved surfaces.

[0025] As shown in FIG. 1 , the wiring body 2 preferably includes a conductive linear body 21 formed in a fork-shaped pattern. If the pair of electrodes 4 is considered to be on the lower side, the conductive linear body 21 extends upward from the electrode 4 located at the lower center left, bends at a right angle at a bend 211, extends to the left, then bends at a right angle at a bend 211 and extends upward. Then, it bends at a right angle at a bend 211, extends to the right, then bends at the next bend 211 and extends downward. In this manner, one tip of the fork is formed. Subsequently, as the conductive linear body 21 is formed into the fork-shaped pattern, it reaches the electrode 4 located at the lower center right. Bending at a right angle at a bend 211 like this has the advantage of making the pattern easier to form. In this case, the number of fork tips is three. The number of fork tines is not limited, but the more fork tines there are, the denser the pattern can be formed. The number of fork tines is preferably two or more, more preferably four or more, and even more preferably six or more.

[0026] The wiring body 2 is not limited to this configuration, and may have the following configuration, for example. Another embodiment of the wiring body 2 is a wiring body 2A shown in FIG. 4(A). As shown in FIG. 4(A), the wiring body 2A includes two conductive linear bodies 21. The number of conductive linear bodies 21 may be two or more. In such a case, the contact area between the wiring body 2A and the electrode 4 is sufficient to be only the ends of the two conductive linear bodies 21, so the area of ​​the electrode 4 can be reduced. This also improves the ability of the wiring sheet 100 to conform to curved surfaces. The wiring body 2A includes a conductive linear body 21 formed in a fork-shaped pattern and another conductive linear body 21 inside the conductive linear body 21 also formed in a fork-shaped pattern. In this way, the patterns of the two conductive linear bodies 21 may be the same. The conductive linear body 21 formed in the fork-shaped pattern is as described above. In Fig. 4(A), the number of fork tips is three.

[0027] Another embodiment of the wiring body 2 is the wiring body 2B shown in Fig. 4(B). The wiring body 2B has a structure in which a plurality of conductive linear bodies 21 are arranged at intervals. As shown in Fig. 4(B), the wiring body 2B preferably has a structure in which a plurality of conductive linear bodies 21 are arranged in parallel. The electrodes 4 are disposed so as to be electrically connected to both ends of the conductive linear bodies 21. In this case, the interval between the conductive linear members 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. The interval between the conductive linear members 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. If the spacing between conductive linear bodies 21 is within the above range, the conductive linear bodies are relatively densely packed, which improves the function of wiring sheet 100, such as maintaining low resistance of wiring body 2B.

[0028] Another embodiment of the wiring body 2 is wiring body 2C shown in FIG. 4(C). Wiring body 2C has a configuration similar to that of wiring body 2B, but differs in the shape of conductive linear body 21 in a plan view. That is, conductive linear body 21 may have a wave shape in a plan view of wiring sheet 100. Examples of wave shapes include a sine wave, a rectangular wave, a triangular wave, and a sawtooth wave. If wiring body 2C has such a structure, breakage of conductive linear body 21 can be suppressed when wiring sheet 100 is stretched in the axial direction of conductive linear body 21.

[0029] 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 It is more preferable that the resistance is Ω·m or more, and 1.0×10 -8The volume resistivity of the conductive linear body 21 is more preferably 1.0×10 -3 It is preferable that the resistance is Ω·m or less, and 1.0×10 -4 It is more preferable that 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 tends to decrease. The volume resistivity of the conductive linear body 21 was measured as follows. Silver paste was applied to the end of the conductive linear body 21 and to a portion 40 mm from the end, and the resistance of the end and the portion 40 mm from the end was measured. Then, the cross-sectional area (unit: m 2 ) is multiplied 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.

[0030] 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 first resin layer 3, the cross-sectional shape of the conductive linear body 21 is preferably elliptical or circular.

[0031] When the cross section of the conductive linear member 21 is circular, the diameter D (see FIGS. 2 and 3) of the conductive linear member 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 member 21 is more preferably 5 μm or more, and even more preferably 9 μm or more. The diameter D of the conductive linear member 21 is more preferably 150 μm or less, even more preferably 100 μm or less, particularly preferably 50 μm or less, and extremely preferably 40 μm or less. When the cross section of the conductive linear body 21 is elliptical, it is preferable that the major axis is in the same range as the diameter D described above.

[0032] 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.

[0033] The conductive linear body 21 may be formed by any method, such as etching, screen printing, or inkjet printing. Preferably, the conductive linear body 21 is a linear body containing a metal wire (hereinafter also referred to as a "metal wire linear body"). Metal wires have 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, the current required for heating the wiring sheet 100 can be passed through the metal wire linear body. 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 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. The conductive linear body 21 may be a metal wire linear body, a linear body containing carbon nanotubes, or a linear body in which a thread is coated with a conductive material.

[0034] The metal wire linear body may be a linear body made of a single metal wire, or may be a linear body made of a plurality of twisted metal wires. Examples of metal wires 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. The metal wire may be plated with gold, tin, zinc, silver, nickel, chromium, nickel-chromium alloy, or solder, or may be surface-coated with a carbon material or polymer, as described below. Wires containing one or more metals selected from tungsten and molybdenum, and alloys containing these, are particularly preferred from the viewpoint of low volume resistivity. The metal wire may be a metal wire coated with a carbon material. When the metal wire is coated with a carbon material, the metallic luster of the metal wire is reduced, making it easier to make the metal wire less noticeable. Furthermore, when the metal wire is coated with a carbon material, metal corrosion is also suppressed. Examples of the carbon material that can be used to coat the metal wire include amorphous carbon such as carbon black, activated carbon, hard carbon, soft carbon, mesoporous carbon, and carbon fiber; graphite, fullerene, graphene, and carbon nanotubes.

[0035] The conductive linear body 21 may be a linear body in which a conductive coating is applied to the thread. Examples of the thread include threads spun from resins such as nylon or polyester. Examples of the thread include threads made of metal fiber, carbon fiber, or ion-conductive polymer fiber. Examples of the conductive coating include coatings made of metal, conductive polymer, or carbon material. The conductive coating can be formed by plating, vapor deposition, or the like. A linear body in which a conductive coating is applied to the thread can improve the conductivity of the linear body while maintaining the flexibility of the thread. In other words, it becomes easier to reduce the resistance of the wiring body 2.

[0036] (resin layer) The first resin layer 3 directly or indirectly supports the wiring body 2. The second resin layer 5 is provided so as to cover the wiring body 2. The first resin layer 3 and the second resin layer 5 are preferably layers containing an adhesive. For example, when forming the wiring body 2 on the first resin layer 3, the adhesive makes it easy to attach the conductive linear body 21 to the first resin layer 3. The second resin layer 5 also allows the wiring sheet 100 to be attached to an adherend.

[0037] The storage modulus of the first resin layer 3 at 23°C is 1.0 × 10 4 Pa or more, 5.0×10 6 It is preferable that the storage modulus is equal to or less than 100 Pa. If the storage modulus is within the above range, the conductive linear body 21 can be appropriately embedded in the first resin layer 3 when the wiring body 2 is formed in the first resin layer 3. The storage modulus of the second resin layer 5 at 23°C is not particularly limited. The storage modulus of the second resin layer 5 at 23°C is 1.0×10 4 Pa or more, 5.0×10 6 It may be less than Pa.

[0038] The thickness of the first resin layer 3 is not particularly limited. The thickness of the first resin layer 3 may be equal to or greater than the diameter D of the conductive linear member 21, or may be less than the diameter D of the conductive linear member 21. When the thickness of the first resin layer 3 is equal to or greater than the diameter D of the conductive linear member 21, the wiring body 2 can be contained within the first resin layer 3. When the thickness of the first resin layer 3 is less than the diameter D of the conductive linear member 21, the wiring body 2 is exposed from the first resin layer 3. Furthermore, when the wiring body 2 is exposed from the first resin layer 3, the wiring body 2 may be exposed on the side of the urethane base material 1 or on the side opposite to the urethane base material 1. The thickness of the first resin layer 3 is preferably equal to or greater than 5 μm, more preferably equal to or greater than 10 μm, and even more preferably equal to or greater than 20 μm. The thickness of the first resin layer 3 is preferably equal to or less than 100 μm, more preferably equal to or less than 70 μm, and even more preferably equal to or less than 50 μm. The thickness of the second resin layer 5 is not particularly limited. The thickness of the second resin layer 5 is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. The thickness of the first resin layer 3 is preferably 100 μm or less, more preferably 70 μm or less, and even more preferably 50 μm or less. If the thickness is within the above range, the conductive linear member 21 can be sealed in the resin, and electrical insulation can be ensured.

[0039] The first resin layer 3 and the second resin layer 5 may be layers formed from an adhesive containing a pressure-sensitive adhesive. The pressure-sensitive adhesive is not particularly limited. Examples of pressure-sensitive adhesives include acrylic adhesives, urethane adhesives, rubber adhesives, polyester adhesives, silicone adhesives, and polyvinyl ether adhesives. Among these, the pressure-sensitive adhesive is preferably at least one selected from the group consisting of acrylic adhesives, urethane adhesives, and rubber adhesives, and more preferably an acrylic adhesive.

[0040] Examples of acrylic pressure-sensitive adhesives include polymers containing structural units derived from alkyl (meth)acrylates having a linear alkyl group or a branched alkyl group, and acrylic polymers containing structural units derived from (meth)acrylates having a cyclic structure. Here, "(meth)acrylate" is used as a term that refers to both "acrylate" and "methacrylate," and the same applies to other similar terms.

[0041] When the acrylic polymer is a copolymer, the form of the copolymerization is not particularly limited, and the acrylic copolymer may be any of a block copolymer, a random copolymer, or a graft copolymer.

[0042] From the viewpoint of increasing the storage modulus, the first resin layer 3 and the second resin layer 5 are preferably layers made of a cured product of a curable adhesive. Such first resin layer 3 and second resin layer 5 can stabilize the resistance value of the wiring body 2. That is, the first resin layer 3 and second resin layer 5 can fix the conductive linear body 21, stabilize the contact between the conductive linear body 21 and the electrode 4, and make it difficult for an increase in the resistance value to occur. Examples of curable adhesives include thermosetting adhesives that are cured by heat, and energy ray-curable adhesives. Examples of energy rays include ultraviolet rays, visible energy rays, infrared rays, and electron beams. Note that "energy ray curing" also includes thermal curing by heating using energy rays.

[0043] The curable adhesive preferably contains a thermosetting resin. Thermosetting resins are 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 compounds, and acid anhydride compounds. These can be used alone or in combination of two or more. Among these, epoxy resins, phenolic resins, melamine resins, urea resins, amine compounds, and acid anhydride compounds are preferred from the viewpoint of suitability for curing using an imidazole 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 compounds, and acid anhydride compounds are preferred from the viewpoint of exhibiting excellent curability, and epoxy resins are preferred.

[0044] As the epoxy resin, a cyclic one such as an aromatic epoxy resin or an alicyclic epoxy resin is preferred from the viewpoint of increasing the storage modulus of the first resin layer 3 and the second resin layer 5. An epoxy resin having a flexible segment such as an oxyalkylene chain tends to decrease the storage modulus of the first resin layer 3 and the second resin layer 5.

[0045] 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.

[0046] 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. Examples of the (meth)acrylate include (meth)acrylates containing a chain aliphatic skeleton such as acrylate; (meth)acrylates containing a cyclic aliphatic skeleton 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.

[0047] 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.

[0048] The adhesive may contain one kind of energy ray curable resin or two or more kinds of energy ray curable resins. When two or more kinds of energy ray curable resins are contained, the combination and ratio thereof can be selected arbitrarily.

[0049] 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.

[0050] Examples of the photopolymerization initiator include photoradical polymerization initiators such as benzophenone, acetophenone, benzoin, benzoin methyl ether, 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.

[0051] 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.

[0052] Examples of the photocationic polymerization 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, bromine salt compounds, etc. Among these, from the viewpoints of excellent compatibility and excellent storage stability of the resulting adhesive, sulfonium salt compounds are preferred, and aromatic sulfonium salt compounds having an aromatic group are more preferred.

[0053] Examples of sulfonium salt compounds include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, and triphenylsulfonium tetrakis(pentafluorophenyl)borate.

[0054] Examples of iodonium salt compounds include diphenyliodonium tetrakis(pentafluorophenyl)borate, diphenyliodonium hexafluorophosphate, and (tricumyl)iodonium tetrakis(pentafluorophenyl)borate.

[0055] Examples of the phosphonium salt compound include tri-n-butyl(2,5-dihydroxyphenyl)phosphonium bromide and hexadecyltributylphosphonium chloride.

[0056] Examples of the ammonium salt compound include benzyltrimethylammonium chloride, phenyltributylammonium chloride, and benzyltrimethylammonium bromide.

[0057] Examples of antimonate compounds include triphenylsulfonium hexafluoroantimonate, p-(phenylthio)phenyldiphenylsulfonium hexafluoroantimonate, and diaryliodonium hexafluoroantimonate.

[0058] Examples of the thermal polymerization initiator include 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 thermal radical polymerization initiators such as organic peroxides such as benzoyl peroxide, lauroyl peroxide, peracetic acid, persuccinic acid, di-t-butyl peroxide, t-butyl hydroperoxide, and cumene hydroperoxide.

[0059] 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 by 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 from the viewpoints of easy availability and the ease with which a product with superior adhesion and transparency can be obtained.

[0060] Examples of sulfonium salts include triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, and triphenylsulfonium hexafluoroarsinate.

[0061] Examples of quaternary ammonium salts include tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, and tetrabutylammonium hydrogen sulfate. Examples of phosphonium salts include ethyltriphenylphosphonium hexafluoroantimonate and tetrabutylphosphonium hexafluoroantimonate.

[0062] Examples of diazonium salts include benzenediazonium chloride, etc. Examples of iodonium salts include diphenyliodonium hexafluoroarsinate, bis(4-chlorophenyl)iodonium hexafluoroarsinate, and phenyl(4-methoxyphenyl)iodonium hexafluoroarsinate, etc.

[0063] 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.

[0064] When a thermosetting resin is used, a curing catalyst such as an imidazole-based curing catalyst may be used.

[0065] 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 maintaining 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.

[0066] These flexibility-adjusting components can be used alone or in combination of two or more.

[0067] When the curable adhesive used in this embodiment contains a flexibility-adjusting component, the total amount of the energy ray-curable resin and 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, per 100 parts by mass of the flexibility-adjusting component, from the viewpoint of adjusting the storage modulus of the first resin layer 3 and the second resin layer 5 within the above-mentioned range. 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 first resin layer 3 and the second resin layer 5 tends to be too high.

[0068] In this embodiment, the curable adhesive preferably does not contain a filler. When the adhesive does not contain a filler, the storage modulus at 23°C of the first resin layer 3 and the second resin layer 5 can be prevented from becoming too high. However, the curable adhesive may contain a filler to the extent that the storage modulus at 23° C. of the first resin layer 3 and the second resin layer 5 can be adjusted to fall within the above range.

[0069] 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. One type of filler may be used alone, or two or more types may be used in combination.

[0070] 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.

[0071] (electrode) 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. The electrode 4 can be formed using a known electrode material. Examples of the electrode material include a conductive paste such as silver paste, a metal foil such as copper foil, and a metal wire. When the electrode material is a metal wire, the metal wire may be one wire, but preferably two or more wires.

[0072] When the electrode material is a metal foil or metal wire, examples of the metal for 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 also be plated with gold, tin, zinc, silver, nickel, chromium, nickel-chromium alloy, solder, or the like.

[0073] The width of at least one of the electrodes 4 is preferably 10 mm or less, and more preferably 5 mm or less, in a plan view of the wiring sheet 100. The width of this electrode is preferably 0.1 mm or more. When at least one of the electrodes is a metal wire, the width of the electrode is the diameter of the metal wire. When two or more metal wires are used, the width of one electrode refers to the sum of the diameters of the metal wires when the metal wires are arranged side by side, or refers to the long diameter of the bundle of metal wires when viewed in a plan view.

[0074] The length of at least one of the electrodes 4 is preferably 30 mm or less, and more preferably 20 mm or less, in a plan view of the wiring sheet 100. The length of this electrode is preferably 1 mm or more. In this embodiment, the number of conductive linear bodies 21 is small, so the length of the electrode 4 can be short.

[0075] The thickness of the electrode 4 is preferably 2 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more. The thickness of the electrode 4 is preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and particularly preferably 75 μm or less. If the thickness of the electrode 4 is within the above range, the electrical conductivity is high and the resistance is low, and the resistance value with the wiring body 2 can be kept low. Furthermore, sufficient strength as an electrode can be obtained. Note that when the electrode is a metal wire, the thickness of the electrode is the diameter of the metal wire.

[0076] (Use of wiring sheet, etc.) The wiring sheet 100 according to this embodiment can be suitably used, for example, as a sheet heater. In this case, examples of uses of the sheet heater include a defogger for window glass and a defroster.

[0077] (Use of wiring sheet) The wiring sheet 100 according to this embodiment can be used by adhering it to an adherend 9, as shown in Fig. 5. That is, the sheet heating element 200 can be produced by adhering the wiring sheet 100 to an adherend 9 via an adhesive layer 6 provided on the second resin layer 5 of the wiring sheet 100, as shown in Fig. 5. The wiring sheet 100 comprises a urethane base material 1, a wiring element 2, a first resin layer 3, a pair of electrodes 4, and a second resin layer 5. Examples of the pressure-sensitive adhesive layer 6 include the above-mentioned first resin layer 3 or second resin layer 5 before curing.

[0078] (Method of manufacturing wiring sheet) There are no particular limitations on the method for manufacturing interconnect sheet 100 according to this embodiment. Interconnect sheet 100 can be manufactured, for example, as follows. First, an adhesive for forming the first resin layer 3 is applied to the urethane substrate 1 to form a coating film. Next, the coating film is dried to create an adhesive layer. Next, conductive linear members 21 are arranged and placed on the adhesive layer to form the wiring body 2. For example, with the adhesive layer with the urethane substrate 1 placed on the outer circumferential surface of a drum member, the conductive linear members 21 are attached to the adhesive layer while adjusting the axial movement distance, movement speed, and acceleration of the drum, as well as the forward and reverse rotation of the drum. This forms the wiring body 2 including conductive linear members 21 formed with a pattern having at least one bent portion 211, and the wiring body 2 is placed on the adhesive layer. In this way, a wiring body film is obtained in which the wiring body 2 is formed on the adhesive layer with the urethane substrate 1. Next, a pair of electrodes 4 is formed on both ends of conductive linear body 21 in wiring body 2 of the sheet-like conductive member. In this manner, wiring sheet 100 can be produced.

[0079] [Effects of the embodiment] According to this embodiment, the following effects can be achieved. (1) According to this embodiment, wiring sheet 100 having excellent blister resistance, chipping resistance, transparency, and curved surface conformability can be produced. (2) According to this embodiment, the conductive linear body 21 can be sealed in the first resin layer 3 and the second resin layer 5, and electrical insulation can be ensured. (3) According to this embodiment, the number of conductive linear bodies 21 can be reduced. The contact area between wiring body 2 and electrode 4 is sufficient at both ends of a small number of conductive linear bodies 21, so the area of ​​electrode 4 can be reduced. As a result, wiring sheet 100 with excellent curved surface conformability can be produced. (4) According to this embodiment, when forming the wiring body 2 on the first resin layer 3, the adhesive makes it easy to attach the conductive linear body 21 to the first resin layer 3. Therefore, it is easy to form the wiring body 2 including the conductive linear body 21 on which a predetermined pattern is formed.

[0080] [Modification of the embodiment] The present invention is not limited to the above-described embodiment, and includes modifications and improvements within the scope of achieving the object of the present invention. For example, in the above-described embodiment, the wiring sheet 100 is configured to be attached to the adherend 9 via the pressure-sensitive adhesive layer 6 provided on the second resin layer 5, but this is not limiting. For example, a protective sheet (not shown) may be provided on the second resin layer 5 of the wiring sheet 100. In such a case, a layer (not shown) containing an adhesive may be further provided on the protective sheet, and the wiring sheet may be attached to the adherend 9 via this layer. [Example]

[0081] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. Unless otherwise specified, the blending ratios shown in parts by mass are the ratios of solid content.

[0082] [Preparation Example 1] A pressure-sensitive adhesive was prepared by mixing 100 parts by mass of an acrylic copolymer (2-ethylhexyl acrylate (2EHA) / vinyl acetate (VAc) / acrylic acid (AA) = 74 / 24 / 2 (mass ratio), weight average molecular weight (Mw): 600,000) with 0.15 parts by mass of aluminum tris(acetylacetonate) as a crosslinking agent, diluting with toluene, and stirring uniformly. The storage modulus of a dried film of this pressure-sensitive adhesive measured at 23°C under the following conditions was 4.7 x 10 4 It was Pa.

[0083] [Preparation Example 2] A pressure-sensitive adhesive was prepared by mixing 100 parts by mass of an acrylic copolymer (weight average molecular weight (Mw): 410,000) having structural units derived from raw material monomers consisting of acrylic resin (n-butyl acrylate (BA) / acrylic acid (AA) = 90 / 10 (mass ratio)) with 0.74 parts by mass of aluminum tris(acetylacetonate) as a crosslinking agent, diluting with toluene, and stirring uniformly. The storage modulus of a dried film of this pressure-sensitive adhesive measured at 23°C under the following conditions was 1.4 x 105 It was Pa.

[0084] [Storage modulus measurement] A cylindrical test sample with a diameter of 8 mm and a thickness of 1 mm was prepared from the same composition as the layer to be measured. The storage modulus of the test sample was measured using a viscoelasticity measuring device (manufactured by Anton Paar, model name "MCR300") with 8 mm diameter parallel plates as the measuring jig at a test temperature of 23°C, a shear strain of 0.05%, and a frequency of 1 Hz.

[0085] [Example 1] A roll-shaped first adhesive film measuring 400 mm × 1000 mm was prepared, in which a 35 μm thick adhesive layer (the pressure-sensitive adhesive obtained in Preparation Example 1) was provided as a first resin layer on a 150 μm thick urethane substrate (manufactured by Nihon Matai Co., Ltd., product name "ESMER URSPPX#15PFT50X"), and a gold-plated tungsten wire (diameter: 35 μm, volume resistivity: 5.5 × 10) was used as a wire. -8 A wire wound around a bobbin was attached to the surface of the adhesive layer of a pressure-sensitive adhesive film located near the end of the drum. The wire was compressed with a nip roll while being unwound, and the movement distance, movement speed, and acceleration in the axial direction of the drum, as well as the forward and reverse rotation of the drum, were adjusted to form a wiring structure with a wire pattern with 5 mm spacing, as shown in Figure 1. This was then attached to a 38 μm-thick release film (manufactured by Lintec Corporation, product name "SP-PET382150") using a laminator to create a wiring structure film. Next, a second adhesive film measuring 400 mm x 1000 mm was prepared as the adherend, which had a 150 μm thick urethane substrate (manufactured by Nippon Matai Co., Ltd., product name "Esmar URSPPX#15PFT50X") on top of which a 45 μm thick adhesive layer (pressure-sensitive adhesive obtained in Preparation Example 1) and a release material layer were provided as the second resin layer. Next, the release film was peeled off from the wiring film, and electrodes (size: 1 cm x 0.5 cm) were attached to both ends of the wire. A second adhesive film was then placed on top of this with the urethane base layer facing inward, and the two were then bonded together using a laminator to create a surface heating element.

[0086] [Examples 2 to 4 and Comparative Examples 1 to 4] A wiring film and a sheet heating element were prepared in the same manner as in Example 1, except that the thickness and type of the substrate, the thickness and type of the first resin layer, the thickness and type of the second resin layer, and the pattern of the conductive linear element were changed as shown in Table 1. In Comparative Examples 1 to 3, the following base materials were used. PET: 50 μm thick polyethylene terephthalate substrate (manufactured by Toyobo Co., Ltd., product name "Cosmoshine A4160") Nonwoven fabric: 150 μm thick nonwoven fabric (manufactured by Nippon Paper Papylia Co., Ltd., product name "Kansenshi") COP: 50 μm thick cycloolefin polymer substrate (manufactured by Zeon Corporation, product name "ZeonorFilm ZF16")

[0087] [Wiring sheet evaluation] The wiring sheets obtained in each example were evaluated as follows, and the results are shown in Table 2.

[0088] [Evaluation of blister resistance] The surface temperature of the sheet heating element was set to 80°C, and the sheet heating element was checked after 100 hours, and the blister resistance was evaluated according to the following criteria. A: No blistering occurred. F: Blisters occurred.

[0089] [Evaluation of water vapor permeability] The water vapor transmission rate was measured after 24 hours at 40°C in accordance with "Test method for moisture permeability of moisture-proof packaging materials (cup method)" described in JIS Z0208-1976.

[0090] [Evaluation of chipping resistance] A sheet heating element processed to a width of 60 mm and a length of 120 mm was attached to a painted board, and after adhesion was left at room temperature for one week, a chipping resistance test was conducted (stone: basalt No. 6 (4.8-8.0 mm), injection pressure: 0.4 MPa, distance to test piece: 350 cm, angle between test piece and stepping stone: 90°, test temperature: -20°C), and peeling of the surface was confirmed. The chipping resistance was evaluated according to the following criteria. A: No peeling of the surface occurred. F: Peeling of the surface occurred.

[0091] [Transparency evaluation] The total light transmittance and haze of the wiring body film were measured using a measuring device (manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH-5000").

[0092] [Curved surface conformability] The wiring film was cut into a size of 5 cm x 5 cm, and electrodes (gold-plated copper foil manufactured by Mitsuya Co., Ltd., 60 μm thick) were attached to both ends of the conductive linear body to prepare a wiring sheet. The size of the electrodes in Examples 1 and 2 and Comparative Examples 1 and 3 was 1 cm x 0.5 cm, and the size of the electrodes in Examples 3 and 4 and Comparative Example 2 was 5 cm x 0.5 cm. The obtained wiring sheet was then attached by hand to a circular curved surface (diameter: 5 cm), and the presence or absence of air bubbles and wrinkles (waviness) upon attachment was evaluated according to the following criteria. A: No bubbles or wrinkles (waviness) occurred. F: Bubbles or wrinkles (waviness) occurred.

[0093] [Evaluation of electrical insulation] After the sheet heating element was subjected to an insulation resistance test (DC 5000V, 1 minute), it was checked for any leakage current and the electrical insulation was evaluated according to the following criteria. A: No electrical leakage occurred. F: An electrical fault has occurred.

[0094] [Table 1]

[0095] [Table 2]

[0096] As shown in Table 2, the wiring sheets using the wiring body films obtained in Examples 1 to 4 had good evaluation results for blister resistance, chipping resistance, transparency, and curved surface conformability. This confirmed that the wiring sheets according to the present invention have excellent blister resistance, chipping resistance, transparency, and curved surface conformability. [Explanation of symbols]

[0097] 1...urethane base material, 2, 2A, 2B, 2C...wiring body, 21...conductive linear body, 211...bending portion, 3...first resin layer, 4...electrode, 5...second resin layer, 6...adhesive layer, 9...adherend, 100...wiring sheet, 200...sheet heating element.

Claims

1. a wiring body including a conductive linear body; a pair of electrodes in direct contact with the conductive linear body; a first resin layer that directly or indirectly supports the wiring body; a urethane base material that directly or indirectly supports the wiring body; Equipped with The thickness of the urethane base material is 110 μm or more, The water vapor permeability of the urethane base material is 15 g / m ２ / day or more, Wiring sheet.

2. The wiring sheet according to claim 1 , Further, a urethane base material and a second resin layer are provided between the adherend and the wiring sheet, the urethane base material, the first resin layer, the wiring body, the electrode, the urethane base material, and the second resin layer are provided in this order in the thickness direction of the wiring sheet; Wiring sheet.

3. The wiring sheet according to claim 1 or 2, The total light transmittance of the wiring sheet is 75.0% or more. Wiring sheet.

4. The wiring sheet according to claim 1 or 2, The thickness of the first resin layer is 5 μm or more and 100 μm or less. Wiring sheet.

5. The wiring sheet according to claim 1 or 2, The storage modulus of the first resin layer at 23°C is 1.0 × 10 ４ Pa or more, 5.0×10 ６ Pa or less, Wiring sheet.

6. The wiring sheet according to claim 1 or 2, The conductive linear body has a pattern formed thereon having at least one bent portion in a plan view. Wiring sheet.

7. The wiring sheet according to claim 6, The wiring body is made of one of the conductive linear bodies. Wiring sheet.

8. The wiring sheet according to claim 6, The wiring body includes two or more of the conductive linear bodies. Wiring sheet.

9. The wiring sheet according to claim 1 or 2, The wiring body has a structure in which a plurality of the conductive linear bodies are arranged at intervals. Wiring sheet.

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