Wiring sheet

Abstract

To provide a wiring sheet in which the diameter of a conductive linear body is sufficiently small and which has excellent curved surface lamination properties.SOLUTION: A wiring sheet 100 includes a wiring body 2 having a conductive linear body 21 on which a pattern having at least one bent portion 211 is formed in a planar view, a pair of electrodes 4 in direct contact with the conductive linear body 21, and a resin layer 3 that directly or indirectly supports the wiring body 2, and the diameter of the conductive linear body 21 is 30 μm or less.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] As a wiring sheet that can be used for a planar heater, for example, Patent Document 1 describes a film heater in which a conductive pattern made of conductive wires is provided on one surface of a support sheet made of a transparent thermoplastic resin sheet. The other surface of this support sheet has irregularities, and the conductive pattern has a connection terminal portion, a lead wire extending from this connection terminal portion, and a heater portion continuing from this lead wire.

[0003] Also, Patent Document 2 describes a conductive sheet having a pseudo-sheet structure in which a plurality of linear bodies extending in one direction are arranged at intervals. And by providing a pair of electrodes at both ends of the plurality of linear bodies, a wiring sheet that can be used as a heating element can be obtained.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The film heater described in Patent Document 1 is produced by embedding a conductive wire in a thermoplastic resin with an ultrasonic welder. However, when the diameter of the conductive wire is less than 30 μm, there is a problem that the conductive wire breaks when it is embedded, and the film heater cannot be produced. In addition, for the wiring sheet described in Patent Document 2, it is necessary to arrange electrodes at opposing positions. In such a case, it is necessary to increase the area of the electrodes. This is not a problem when the wiring sheet is flat, but when the wiring sheet is adhered to a curved surface, it is likely to cause bubbles, wrinkles, or undulations. That is, if the area of the electrodes can be reduced, a wiring sheet with good removal of bubbles and wrinkles and excellent conformability to a curved surface can be obtained.

[0006] An object of the present invention is to provide a wiring sheet in which the diameter of the conductive linear body is sufficiently thin and which has excellent conformability to a curved surface.

Means for Solving the Problems

[0007] [1] A wiring body including a conductive linear body in which a pattern having at least one bent portion is formed in a plan view, a pair of electrodes that directly contact the conductive linear body, a resin layer that directly or indirectly supports the wiring body, and the diameter of the conductive linear body is 30 μm or less, a wiring sheet.

[0008] [2] In the wiring sheet according to [1], the resin layer is a layer containing an adhesive, a wiring sheet.

[0009] [3] In the wiring sheet according to [2], the adhesive contains a thermosetting resin, a wiring sheet.

[0010] [4] In the wiring sheet according to [2], the adhesive contains a pressure-sensitive adhesive, a wiring sheet.

[0011] [5] In the wiring sheet according to any one of [1] to [4], further, a base material that directly or indirectly supports the wiring body is provided. Wiring sheet.

[0012] [6] In the wiring sheet according to any one of [1] to [5], the wiring body is composed of one of the conductive linear bodies, Wiring sheet.

[0013] [7] In the wiring sheet according to any one of [1] to [5], the wiring body includes two or more of the conductive linear bodies, Wiring sheet.

Effect of the Invention

[0014] According to one aspect of the present invention, it is possible to provide a wiring sheet in which the diameter of the conductive linear body is sufficiently thin and the surface conformability is excellent.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0016] [Embodiment] Hereinafter, the present invention will be described based on the drawings by taking an embodiment as an example. The present invention is not limited to the content of the embodiment. In the drawings, there are parts that are illustrated enlarged or reduced for ease of explanation.

[0017] [Wiring sheet] As shown in FIGS. 1, 2, and 3, the wiring sheet 100 according to the present embodiment includes a base material 1, a wiring body 2, a resin layer 3, and a pair of electrodes 4. 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. Further, the resin layer 3 supports the wiring body 2 directly or indirectly. As shown in FIG. 3, the electrode 4 is provided on the resin layer 3 and is in direct contact with the conductive linear body 21. Also, the pair of electrodes 4 and a power source (not shown) can be electrically connected. Note that, as shown in FIG. 3, the wiring sheet 100 is preferably provided in the order of the base material 1, the resin layer 3, the conductive linear body 21, and the electrode 4. Then, the wiring sheet 100 can be adhered to an adherend (not shown) by the resin layer 3 and used. Also, the adherend may have a curved surface.

[0018] The inventors of the present invention surmise that the reason why the wiring sheet 100 according to the present embodiment has a sufficiently thin diameter of the conductive linear body and excellent curved surface conformability is as follows. That is, it is not necessary to embed the wiring body 2 in the resin layer 3 using an ultrasonic welder or the like. Therefore, the diameter of the conductive linear body 21 can be made sufficiently thin. Also, in the present embodiment, since the number of the conductive linear bodies 21 is small, the area of the electrode 4 can be reduced. Therefore, it is possible to prevent bubbles, wrinkles, or undulations, which are likely to cause problems when the wiring sheet is adhered to a curved surface.

[0019] (Base material) The base material 1 can support the wiring body 2 directly or indirectly. Note that the base material 1 does not necessarily have to be provided. The base material 1 is a member provided as necessary. Examples of the material of the base material 1 include resin, paper, metal, non-woven fabric, cloth, and glass. Among these, from the viewpoints of strength or handleability, resin or glass is preferable. Examples of the resin used for the base material 1 include polyethylene, polypropylene, polystyrene, polycarbonate, and polyacetal.

[0020] The linear expansion coefficient of the base material 1 is preferably 100×10 -6 / °C or less, and preferably 50×10-6 It is more preferably below / °C. If the linear expansion coefficient is below the above upper limit, the difference from the linear expansion coefficient of the conductive linear body 21 can be made sufficiently small. The linear expansion coefficient of the base material 1 is 1×10 -6 It may be above / °C.

[0021] The thickness of the base material 1 is preferably 10 μm or more, more preferably 18 μm or more, and even more preferably 26 μm or more. The thickness of the base material 1 is preferably 10 mm or less, more preferably 1 mm or less, and even more preferably 300 μm or less. By the thickness of the base material 1 being within the above range, excellent strength and the like can be obtained.

[0022] (Wiring body) 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. In the present embodiment, as shown in FIG. 1, the wiring body 2 preferably consists of one conductive linear body 21. Further, the wiring body 2 preferably has a pattern that can be drawn in one stroke in a plan view. In such a case, the contact portion between the wiring body 2 and the electrode 4 only needs to be at both ends of one conductive linear body 21, so the area of the electrode 4 can be reduced. And the curved surface conformability of the wiring sheet 100 can be improved.

[0023] As shown in FIG. 1, the wiring body 2 includes a conductive linear body 21 formed in a meandering pattern. Also, when the area with the pair of electrodes 4 is on the lower side, the conductive linear body 21 extends upward while slightly shifting to the right from the electrode 4 located in the lower left, and bends into a U shape at the bending portion 211, and then extends downward while slightly shifting to the right. Then, at the bending portion 211, it bends into a U shape and extends upward while slightly shifting to the right. In this way, while meandering, the conductive linear body 21 reaches the electrode 4 located in the lower right. In such a case, the number of the bending portions 211 is seven. The number of the bending portions 211 is not limited, but the more the number of the bending portions 211 is, the denser the pattern can be formed. The number of the bending portions 211 is preferably three or more, more preferably seven or more, and even more preferably eleven or more.

[0024] Note that the wiring body 2 is not limited to such a configuration, and for example, it may be in the following modes. Another embodiment of the wiring body 2 is a wiring body 2A shown in FIG. 4(A). The wiring body 2A includes a conductive linear body 21 formed in a fork-shaped pattern. The conductive linear body 21 extends upward from the electrode 4 located at the bottom center left of FIG. 4(A), bends at a right angle at a bend 211, extends to the left, bends at a right angle at a bend 211 again, and extends upward. The conductive linear body 21 then bends at a right angle at a bend 211, extends to the right, bends at the next bend 211 again, and extends downward. In this manner, one tip of a fork is formed. Thereafter, while forming the fork-shaped pattern, the conductive linear body 21 reaches the electrode 4 located at the bottom center right. Bending at a right angle at a bend 211 like this has the advantage of making it easier to form a pattern. In this case, the number of fork tines is four. The number of fork tines is not limited, but the more fork tines there are, the denser the pattern that 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.

[0025] Another embodiment of the wiring body 2 is wiring body 2B shown in FIG. 4(B). Wiring body 2B includes conductive linear body 21 formed in a cumulonimbus-shaped pattern. Conductive linear body 21 extends upward from electrode 4 located at the bottom center left of FIG. 4(B), gently bends at bend portion 211, and extends upward while shifting to the left. Then, at bend portion 211, it bends and extends upward while shifting to the right, and then it bends again at bend portion 211, and extends upward while shifting to the left. In this way, conductive linear body 21 reaches electrode 4 located at the bottom center right while forming a cumulonimbus-shaped pattern.

[0026] As another aspect of the wiring body 2, there is the wiring body 2C shown in FIG. 4(C). The wiring body 2C includes a conductive linear body 21 formed in the pattern of the shape of a maple leaf. Also, the conductive linear body 21 extends upward from the electrode 4 located at the lower center left in FIG. 4(C), gently bends at the bent portion 211, and extends upward while shifting to the left. Then, at the bent portion 211, it bends into a U shape, extends to the right, bends into a U shape at the bent portion 211, and extends upward while shifting to the left. In this way, one convex portion of the maple leaf can be formed. After that, while forming in the pattern of the maple leaf shape, the conductive linear body 21 reaches the electrode 4 located at the lower center right. In such a case, the number of convex portions of the leaf is five. The number of convex portions of the leaf is not limited, but the larger the number of convex portions of the leaf, the denser the pattern can be formed. It is preferable that the number of convex portions of the leaf is three or more, more preferably five or more, and even more preferably seven or more.

[0027] As another aspect of the wiring body 2, there is the wiring body 2D shown in FIG. 4(D). The wiring body 2D includes a conductive linear body 21 formed in the pattern of a spoon shape. Also, the conductive linear body 21 extends upward from the electrode 4 located at the lower center left in FIG. 4(D), gently bends at the bent portion 211, and extends upward while shifting to the left. Then, at the bent portion 211, it bends and extends upward while shifting to the right, bends at the bent portion 211, and extends downward while shifting to the right. In this way, while forming in the pattern of a spoon shape, the conductive linear body 21 reaches the electrode 4 located at the lower center right.

[0028] As another aspect of the wiring body 2, there is a wiring body 2E shown in FIG. 4(E). As shown in FIG. 4(E), the wiring body 2E includes two conductive linear bodies 21. The number of the conductive linear bodies 21 may be two or more. In such a case, since the contact portion between the wiring body 2E and the electrode 4 only needs to be at both ends of the two conductive linear bodies 21, the area of the electrode 4 can be reduced. And the curvature conformability of the wiring sheet 100 can be improved. The wiring body 2E includes a conductive linear body 21 formed in a rectangular pattern and a conductive linear body 21 formed in a fork-shaped pattern inside thereof. Thus, the patterns of the two conductive linear bodies 21 may be different. The conductive linear body 21 formed in a rectangular pattern extends upward from the electrode 4 located at the lower center left of FIG. 4(E), bends at the bending portion 211 at a right angle, extends to the left, and further bends at the bending portion 211 at a right angle and extends upward. Then, it bends at the bending portion 211 at a right angle, extends to the right, and bends at the bending portion 211 at a right angle and extends downward. In this way, while forming a rectangular pattern, the conductive linear body 21 reaches the electrode 4 located at the lower center right. The conductive linear body 21 formed in a fork-shaped pattern is as described above. In FIG. 4(E), the number of the tip portions of the fork is three.

[0029] As another aspect of the wiring body 2, there is a wiring body 2F shown in FIG. 4(F). As shown in FIG. 4(F), the wiring body 2F includes two conductive linear bodies 21. The wiring body 2F includes a conductive linear body 21 formed in a fork-shaped pattern and a conductive linear body 21 formed in a fork-shaped pattern inside thereof. Thus, the patterns of the two conductive linear bodies 21 may be the same. The conductive linear body 21 formed in a fork-shaped pattern is as described above. In FIG. 4(F), the number of the tip portions of the fork is three.

[0030] 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 -8 The 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.

[0031] 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.

[0032] 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 of the wiring sheet 100, the diameter D of the conductive linear member 21 is more preferably 4 μm or more, and even more preferably 5 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 20 μm or less. However, from the viewpoint of the object of the present invention, which is to make the diameter of the conductive linear body 21 sufficiently thin, the diameter D of the conductive linear body 21 must be 30 μm or less, and is preferably less than 30 μm. 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.

[0033] 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.

[0034] 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 conductive coating is applied to a thread.

[0035] 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.

[0036] 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.

[0037] (resin layer) The resin layer 3 directly or indirectly supports the wiring body 2. The resin layer 3 is preferably a layer containing an adhesive. For example, when forming the wiring body 2 on the resin layer 3, the adhesive facilitates the attachment of the conductive linear body 21 to the resin layer 3.

[0038] 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. If 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 included in 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. Further, when the wiring body 2 is exposed from the resin layer 3, the wiring body 2 may be exposed on the side of the base material 1 or on the opposite side of the base material 1. The thickness of the resin layer 3 is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more. The thickness of the resin layer 3 is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 35 μm or less.

[0039] The resin layer 3 may be a layer formed from an adhesive containing a pressure-sensitive adhesive. The pressure-sensitive adhesive is not particularly limited. For example, examples of the pressure-sensitive adhesive 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 the acrylic adhesive include polymers containing structural units derived from alkyl (meth) acrylates having a linear or 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 indicating both “acrylate” and “methacrylate”, and the same applies to other similar terms.

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

[0042] From the viewpoint of making the storage elastic modulus higher, the resin layer 3 is preferably a layer made of a cured product of a curable adhesive. With such a resin layer 3, the resistance value of the wiring body 2 can be stabilized. That is, with this resin layer 3, the conductive linear body 21 can be fixed, the contact between the conductive linear body 21 and the electrode 4 can be stabilized, and an increase in the resistance value can be made less likely to occur. Examples of the curable adhesive include a thermosetting adhesive cured by heat and an energy ray curable adhesive. Examples of the energy ray include ultraviolet rays, visible energy rays, infrared rays, and electron beams. Note that "energy ray curing" includes heat curing by heating using an energy ray.

[0043] The curable adhesive preferably contains a thermosetting resin. The thermosetting resin is not particularly limited, and specifically, examples include epoxy resins, phenol resins, melamine resins, urea resins, polyester resins, urethane resins, acrylic resins, benzoxazine resins, phenoxy resins, amine-based compounds, and acid anhydride-based compounds. These can be used alone or in combination of two or more. Among these, from the viewpoint of being suitable for curing using an imidazole-based curing catalyst, it is preferable to use an epoxy resin, a phenol resin, a melamine resin, a urea resin, an amine-based compound, and an acid anhydride-based compound. In particular, from the viewpoint of exhibiting excellent curability, it is preferable to use an epoxy resin, a phenol resin, a mixture thereof, or a mixture of an epoxy resin and at least one selected from the group consisting of a phenol resin, a melamine resin, a urea resin, an amine-based compound, and an acid anhydride-based compound, and it is preferable to use an epoxy resin.

[0044] As the epoxy resin, cyclic ones such as aromatic epoxy resins or alicyclic epoxy resins are preferable from the viewpoint of increasing the storage elastic modulus of the resin layer 3. Epoxy resins having flexible segments such as oxyalkylene chains tend to decrease the storage elastic modulus of the resin layer 3.

[0045] The energy ray curable adhesive preferably contains an energy ray curable resin. Examples of the energy ray curable resin include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferable.

[0046] Examples of the acrylate compound include chain aliphatic skeleton-containing (meth)acrylates such as dicyclopentadiene diacrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxy penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate; 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)acrylate, urethane (meth)acrylate oligomer, epoxy-modified (meth)acrylate, polyether (meth)acrylate other than polyalkylene glycol (meth)acrylate, and itaconic acid oligomer.

[0047] The weight average molecular weight (Mw) of the energy ray-curable resin is preferably 100 or more, more preferably 300 or more. Also, this weight average molecular weight is preferably 30000 or less, more preferably 10000 or less. Note that the weight average molecular weight in this specification is a value in terms of standard polystyrene measured by gel permeation chromatography (GPC) method.

[0048] The energy ray-curable resin contained in the adhesive may be only one kind or two or more kinds. When there are two or more kinds of energy ray-curable resins, their combinations and ratios can be arbitrarily selected.

[0049] When using an energy ray-curable resin or a thermosetting resin, it is preferable to use a photoinitiator, a thermal polymerization initiator, etc. By using a photoinitiator and a thermal polymerization initiator, etc., the polymerization reaction of the curable resin can be easily started, and the control of the curing reaction becomes easy.

[0050] Examples of the photoinitiator include photo radical polymerization initiators such as benzophenone, acetophenone, benzoin, benzoin methyl ether, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, 2-chloroanthraquinone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide.

[0051] Also, examples of the photoinitiator include, in addition to photo radical polymerization initiators, photo cationic polymerization initiators. A photo cationic polymerization initiator is a compound that generates cationic species by irradiation with energy rays and starts the curing reaction of a cationic curable compound, and consists of a cationic part that absorbs energy rays and an anionic part that serves as a source of acid.

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

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

[0054] Examples of the iodonium salt compound 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 the antimonate compound include triphenylsulfonium hexafluoroantimonate, p-(phenylthio)phenyl diphenylsulfonium hexafluoroantimonate, and diallyliodonium 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 the 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 with respect to 100 parts by mass of the flexibility adjusting component, from the viewpoint of adjusting the storage elastic modulus of the resin layer 3 to the above-described range. Further, when the adhesive contains an energy ray curable resin or a thermosetting resin and does not contain a flexibility adjusting component, the storage elastic modulus of the resin layer 3 tends to become too high.

[0068] In this embodiment, the curable adhesive preferably does not contain a filler. When the adhesive does not contain a filler, it is possible to prevent the storage elastic modulus of the resin layer 3 at 23 °C from becoming too high. However, the curable adhesive may contain a filler as long as the storage elastic modulus of the resin layer 3 at 23 °C can be adjusted within the above range.

[0069] Examples of the filler 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 fillers and alumina fillers are preferred. The filler may be used alone or in combination of two or more.

[0070] The curable adhesive may contain other components. Examples of the other components include well-known additives such as organic solvents, coupling agents, flame retardants, tackifiers, ultraviolet absorbers, antioxidants, preservatives, fungicides, plasticizers, defoamers, and wettability adjusters.

[0071] (Electrode) The electrode 4 is used to supply current to the conductive linear body 21. The electrodes 4 are paired. The electrode 4 is in direct contact with the conductive linear body 21. Then, the electrodes 4 are electrically connected and arranged at 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 conductive pastes such as silver paste; metal foils such as copper foil; and metal wires. When the electrode material is a metal wire, the metal wire may be one, but preferably two or more.

[0072] When the electrode material is a metal foil or a metal wire, examples of the metal of the metal foil or the metal wire include metals such as copper, aluminum, tungsten, iron, molybdenum, nickel, titanium, silver, and gold; or steels such as stainless steel and carbon steel, brass, phosphor bronze, zirconium copper alloy, beryllium copper, iron nickel, nichrome, nickel titanium, kanthal, hastelloy, and alloys containing two or more of the above metals such as rhenium tungsten. Further, the metal foil or the metal wire may be plated with gold, tin, zinc, silver, nickel, chromium, nickel chromium alloy, or solder.

[0073] Of the electrodes 4, the width of at least one of the electrodes is preferably 10 mm or less, more preferably 5 mm or less, in a plan view of the wiring sheet 100. Further, 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 of the electrodes when the metal wires are arranged means the sum of the diameters of the respective metal wires. When the metal wires are bundled, it means the major axis in a plan view of this bundle.

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

[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 suppressed low. Also, 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] (Applications of the wiring sheet, etc.) The wiring sheet 100 according to the present embodiment can be suitably used, for example, as a planar heater. In this case, examples of the applications of the planar heater include a defogger for window glass and a defroster.

[0077] (Manufacturing method of the wiring sheet) The manufacturing method of the wiring sheet 100 according to the present embodiment is not particularly limited. The wiring sheet 100 can be manufactured, for example, as follows. First, an adhesive for forming the resin layer 3 is applied onto the base material 1 to form a coating film. Next, the coating film is dried to produce an adhesive layer. Next, while arranging the conductive linear bodies 21, they are disposed on the adhesive layer to form the wiring body 2. For example, while adjusting the moving distance, moving speed, and acceleration in the drum axis direction, and the forward and reverse rotations of the drum, the conductive linear bodies 21 are attached onto the adhesive layer in a state where the adhesive layer with the base material 1 is disposed on the outer peripheral surface of the drum member. Thereby, a wiring body 2 including the conductive linear bodies 21 having at least one bent portion 211 and forming a pattern is formed and disposed on the adhesive layer. In this way, a wiring body film in which the wiring body 2 is formed on the adhesive layer with the base material 1 is obtained. Next, a pair of electrodes 4 are formed at both ends of the conductive linear bodies 21 in the wiring body 2 of the sheet-like conductive member. In this way, the wiring sheet 100 can be manufactured.

[0078] [Operation and Effect of Embodiment] According to this embodiment, the following operation and effect can be achieved. (1) According to this embodiment, in the production of the wiring sheet 100, since processing such as an ultrasonic welder is unnecessary, a wiring sheet 100 with a sufficiently thin diameter of the conductive linear body can be produced. (2) According to this embodiment, the number of conductive linear bodies 21 can be reduced. The contact portion between the wiring body 2 and the electrode 4 only requires both ends of a small number of conductive linear bodies 21, so the area of the electrode 4 can be reduced. And a wiring sheet 100 excellent in curved surface adhesion can be produced. (3) According to this embodiment, when forming the wiring body 2 on the resin layer 3, the adhesive makes it easy to attach the conductive linear body 21 to the resin layer 3. Therefore, the wiring body 2 provided with the conductive linear body 21 having a predetermined pattern can be easily formed.

[0079] [Modification of Embodiment] The present invention is not limited to the foregoing embodiment, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are included in the present invention. For example, in the foregoing embodiment, the wiring sheet 100 includes the base material 1, but is not limited thereto. For example, the wiring sheet 100 may not include the base material 1. Also, in the foregoing embodiment, the wiring sheet 100 is configured to be adhered to an adherend (not shown) by the resin layer 3, but is not limited thereto. For example, a protective sheet (not shown) may be provided on the resin layer 3 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 adherend (not shown) can be adhered and used by this layer.

Example

[0080] Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these examples. Also, unless otherwise specified, the mixing ratios shown in parts by mass are ratios of solid components.

[0081] [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.

[0082] [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 constituent 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.

[0083] [Preparation Example 3] A curable adhesive was prepared 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 glycidyl ether epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name "YX8000", liquid at 25°C, epoxy equivalent 205 g / eq, weight average molecular weight (Mw): 1,400), 0.2 parts by mass of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-4803"), 2 parts by mass of a thermal cationic polymerization initiator (manufactured by Sanshin Chemical Industry Co., Ltd., product name "SAN-AID SI-B3"), and 2 parts by mass of a thermal cationic polymerization initiator (manufactured by Sanshin Chemical Industry Co., Ltd., product name "SAN-AID SI-B7").

[0084] [Example 1] On a polyethylene terephthalate (PET) substrate with a thickness of 50 μm (manufactured by Toray Industries, Inc., product name "Lumirror #50-T11"), a pressure-sensitive adhesive layer with a thickness of 23 μm (the pressure-sensitive adhesive obtained in Preparation Example 1) was provided, and a roll-shaped adhesive film with a size of 400 mm × 1000 mm was prepared. As the wire, a gold-plated tungsten wire (diameter: 10 μm, manufactured by Tokusai Co., Ltd.) was prepared. The wire wound around the bobbin was attached to the surface of the adhesive layer of the adhesive film located near the end of the drum member. While feeding out the wire, it was pressure-bonded with a nip roll, and while adjusting the moving distance, moving speed, and acceleration in the drum axis direction, as well as the forward and reverse rotations of the drum, a wiring body equipped with a wire having a pattern as shown in FIG. 4(A) was formed. Then, a release film with a thickness of 38 μm (manufactured by Lintec Corporation, product name "SP-PET382150") was laminated by a laminator to produce a wiring body film.

[0085] [Examples 2 to 5, Reference Examples 1 to 2, and Comparative Example 1] A wiring body film was produced in the same manner as in Example 1, except that the thickness and type of the substrate, the thickness and type of the resin layer, the diameter and pattern of the conductive linear body were changed as shown in Table 1. In Example 3, a polyvinylidene fluoride / polymethyl methacrylate (PVDF / PMMA) co-extruded substrate (manufactured by Denka Co., Ltd., product name "Denka DX Film 14S0230") was used as the substrate.

[0086] [Evaluation of Wiring Sheet] The evaluation of the wiring sheets obtained in each example was carried out as follows. The results obtained are shown in Table 2.

[0087] [Curved Surface Lamination Test] The wiring film obtained in each example was cut to 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 the examples and reference examples was 1 cm x 0.5 cm, and the electrode in the comparative example 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. (Bubble criteria) A: No bubbles. B: There are bubbles only around the electrodes. C: There are bubbles in areas other than around the electrodes. (Wrinkle criteria) A: No wrinkles. B: Wrinkles are present only around the electrodes. C: There are bubbles in places other than around the electrodes.

[0088] [Table 1]

[0089] [Table 2]

[0090] As shown in Table 2, the wiring sheets using the wiring body films obtained in Examples 1 to 5 had good results in the curved surface bonding test. This confirmed that the wiring sheets according to the present invention have excellent curved surface bonding properties. Furthermore, in the wiring body films obtained in Examples 1 to 5, the diameter of the conductive linear members was 30 μm or less, which indicates that the diameter of the conductive linear members in the wiring sheets according to the present invention is sufficiently small. [Explanation of symbols]

[0091] 1...substrate, 2, 2A, 2B, 2C, 2D, 2E, 2F...wiring body, 21...conductive linear body, 211...bending portion, 3...resin layer, 4...electrode, 100...wiring sheet.

Claims

1. A wiring body including a conductive linear body having at least one bent portion formed therein in a plan view, A pair of electrodes in direct contact with the conductive linear body, A resin layer directly or indirectly supporting the wiring body, Comprising, The diameter of the conductive linear body is 30 μm or less, A wiring sheet.

2. In the wiring sheet according to Claim 1, The resin layer is a layer containing an adhesive, A wiring sheet.

3. In the wiring sheet according to Claim 2, The adhesive contains a thermosetting resin, A wiring sheet.

4. In the wiring sheet according to Claim 2, The adhesive contains a pressure-sensitive adhesive, A wiring sheet.

5. In the wiring sheet according to Claim 1 or Claim 2, Further comprising a substrate directly or indirectly supporting the wiring body, A wiring sheet.

6. In the wiring sheet according to Claim 1 or Claim 2, The wiring body is composed of one conductive linear body, A wiring sheet.

7. In the wiring sheet according to Claim 1 or Claim 2, The wiring body includes two or more conductive linear bodies, A wiring sheet.

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