Laminate

Abstract

A laminate (100) is provided with a first base material (1), a second base material (2) having a higher linear expansion coefficient than the first base material (1), and a wiring sheet (10) sandwiched between the first base material (1) and the second base material (2). A wiring sheet (10) is provided with a wiring body (3) in which a plurality of conductive linear bodies (31) are arranged at intervals, a first resin layer (4) that directly or indirectly supports the wiring body (3), and a pair of electrodes (5) that directly contact the conductive linear bodies (31). A first substrate (1) or a second substrate (2) and the wiring sheet (10) are laminated with a second resin layer (6) having a lower storage modulus than the first resin layer (4) interposed therebetween.

Description

TECHNICAL FIELD

[0001] The present application relates to a laminate. BACKGROUND

[0002] As a wiring sheet that can be used in the use of a planar heater, for example, Patent Literature 1 discloses a wiring sheet that has a sheet-like structure in which a plurality of electrically conductive linear bodies are arranged at intervals, a cured product layer that supports the sheet-like structure, and a pair of electrodes that are in direct contact with the electrically conductive linear bodies. In this wiring sheet, the cured product layer is formed of a cured product of a curable adhesive, and the storage modulus of the cured product layer at 23°C is 5.0 x 10 6 Pa or more and 1.0 x 10 10 Pa or less.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: International Publication No. 2021 / 225142 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] According to the wiring sheet described in Patent Literature 1, it is possible to stabilize the resistance value of a wiring. However, it is known that in the case where the wiring sheet described in Patent Literature 1 is arranged between two substrates that differ in the linear expansion coefficient and used, sometimes one of the substrates can be broken.

[0008] An object of the present application is to provide a laminate that can prevent a substrate from being broken.

[0009] MEANS FOR SOLVING THE PROBLEM

[0010] [1] A laminate that has:

[0011] a first substrate, a second substrate that is higher in the linear expansion coefficient than the first substrate, and a wiring sheet that is sandwiched between the first substrate and the second substrate,

[0012] the wiring sheet has a wiring body in which a plurality of electrically conductive linear bodies are arranged at intervals, a first resin layer that directly or indirectly supports the wiring body, and a pair of electrodes that are in direct contact with the electrically conductive linear bodies,

[0013] the first substrate or the second substrate is laminated together with the wiring sheet with a second resin layer that is lower in the storage modulus than the first resin layer interposed therebetween.

[0014] [2] The laminate according to [1], wherein,

[0015] The storage modulus of the second resin layer at 23°C is 1.0 × 10⁻⁶. 4 Pa or higher and 3.0 × 10 5 Below Pa.

[0016] [3] According to the laminate described in [1] or [2], wherein,

[0017] The storage modulus of the first resin layer at 23°C is 5.0 × 10⁻⁶. 6 Pa or higher and 1.0 × 10 10 Below Pa.

[0018] [4] The laminate according to any one of [1] to [3], wherein,

[0019] The coefficient of linear expansion of the first substrate is 0.01 × 10⁻⁶. -6 / ℃ or higher and 10×10 -6 / ℃ below.

[0020] [5] The laminate according to any one of [1] to [4], wherein,

[0021] The coefficient of linear expansion of the second substrate is 50 × 10⁻⁶. -6 / ℃ or higher and 100×10 -6 / ℃ below.

[0022] [6] The laminate according to any one of [1] to [5], wherein,

[0023] The second substrate and the wiring sheet are stacked together with the second resin layer sandwiched between them.

[0024] According to one aspect of the present invention, a laminate capable of preventing the substrate from cracking can be provided. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating a laminate according to a first embodiment of the present invention.

[0026] Figure 2 It is shown Figure 1 A cross-sectional view of section II-II.

[0027] Figure 3 This is a cross-sectional view showing a laminate according to a second embodiment of the present invention.

[0028] Symbol Explanation

[0029] 1···First substrate

[0030] 2···Second substrate

[0031] 3··· Wiring

[0032] 31···Conductive linear body

[0033] 4··· First resin layer

[0034] 5···Electrode

[0035] 6···Second resin layer

[0036] 10··· Wiring Piece

[0037] 100, 100A... laminated bodies Detailed Implementation

[0038] [First Implementation Method]

[0039] The present invention will now be described with reference to the accompanying drawings, using examples of embodiments. The present invention is not limited to the embodiments described herein. It should be noted that some parts in the accompanying drawings are enlarged or reduced for ease of explanation.

[0040] (Layered structure)

[0041] like Figure 1 and Figure 2 As shown, the laminate 100 of this embodiment includes: a first substrate 1, a second substrate 2 with a higher coefficient of linear expansion than the first substrate 1, and a wiring sheet 10 sandwiched between the first substrate 1 and the second substrate 2.

[0042] Furthermore, the wiring sheet 10 includes: a wiring body 3 formed by multiple conductive wires 31 arranged at intervals, a first resin layer 4 that directly or indirectly supports the wiring body 3, and a pair of electrodes 5 that are in direct contact with the conductive wires 31.

[0043] Furthermore, the first substrate 1 or the second substrate 2 is laminated together with the wiring sheet 10, sandwiching a second resin layer 6 with a lower energy storage modulus than the first resin layer 4. It should be noted that in... Figure 2 In the middle, the second substrate 2 and the wiring sheet 10 are sandwiched between the second resin layer 6 and stacked together.

[0044] In addition, the second substrate 2 has two holes through which a pair of electrodes 5 can be electrically connected to a power source (not shown in the figure).

[0045] The inventors speculate that the reason why the laminate 100 of this embodiment can prevent the substrate from cracking is as follows.

[0046] That is, the reason for the breakage of the second substrate 2 is due to the difference in the linear expansion coefficient between the first substrate 1 and the second substrate 2. For example, in the case where the laminate 100 becomes high temperature, the second substrate 2 expands more than the first substrate 1. Also, since the first substrate 1 and the second substrate 2 are fixed by the wiring sheet 10 being interposed therebetween, a strain is generated in the second substrate 2, and breakage occurs. In this embodiment, however, the first substrate 1 or the second substrate 2 is laminated with the wiring sheet 10 interposed therebetween with the second resin layer 6 having a lower storage modulus than the first resin layer 4. Also, the second resin layer 6 is easily deformed since it has a low storage modulus. Therefore, in the case where the laminate 100 becomes high temperature, the strain generated in the second substrate 2 is alleviated by the deformation of this second resin layer 6. Thus, breakage of the substrate can be prevented.

[0047] (First Substrate)

[0048] The first substrate 1 can directly or indirectly support the wiring body 3. In addition, by the first substrate 1, one side of the wiring sheet 10 can be protected.

[0049] The linear expansion coefficient of the first substrate 1 is lower than the linear expansion coefficient of the second substrate 2. In this way, even if there is a difference in the linear expansion coefficient, according to this embodiment, breakage of the second substrate 2 can be prevented.

[0050] The linear expansion coefficient of the first substrate 1 can be 0.01 x 10 -6 / °C or more, 0.1 x 10 -6 / °C or more, or 0.5 x 10 -6 / °C or more. In addition, the linear expansion coefficient of the first substrate 1 is preferably 20 x 10 -6 / °C or less, more preferably 10 x 10 -6 / °C or less, and particularly preferably 5 x 10 -6 / °C or less. Note that the linear expansion coefficient can be measured by the method described in the Examples described later. In addition, the conditions at the time of measuring the linear expansion coefficient are as described later.

[0051] As the material of the first substrate 1, from the viewpoint of the strength and handleability of the laminate, a resin, glass, or the like is preferable.

[0052] In the case where the first substrate 1 is in a film shape, the thickness of the first substrate 1 is not particularly limited. The thickness of the first substrate 1 is preferably 10 μm or more, more preferably 15 μm or more, and further preferably 50 μm or more. In addition, the thickness of the first substrate 1 is preferably 10 mm or less, more preferably 5 mm or less, and further preferably 3 mm or less.

[0053] (Second Substrate)

[0054] The second substrate 2 can directly or indirectly support the wiring body 3. In addition, by the second substrate 2, one face of the wiring sheet 10 can be protected.

[0055] The coefficient of linear expansion of the second substrate 2 is higher than that of the first substrate 1. Thus, even if there is a difference in the coefficient of linear expansion, according to the present embodiment, it is possible to prevent the second substrate 2 from being broken.

[0056] The coefficient of linear expansion of the second substrate 2 is preferably 30 x 10 -6 / °C or more, more preferably 45 x 10 -6 / °C or more, and further preferably 60 x 10 -6 / °C or more. In addition, the coefficient of linear expansion of the second substrate 2 is preferably 200 x 10 -6 / °C or less, more preferably 150 x 10 -6 / °C or less, and further preferably 100 x 10 -6 / °C or less. Note that the method of measuring the coefficient of linear expansion is described later.

[0057] As the material of the second substrate 2, from the viewpoint of the handleability of the laminate and the suitability of manufacture, a resin or the like is preferable.

[0058] As the resin, for example, polyethylene, polypropylene, polybutylene, polybutadiene, polymethylpentene, polyvinyl chloride, a vinyl chloride copolymer, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyurethane, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer, polystyrene, polycarbonate, a cyclic olefin polymer, and polyimide, or the like can be given.

[0059] In the case where the second substrate 2 is in a film shape, the thickness of the second substrate 2 is not particularly limited. The thickness of the second substrate 2 is preferably 10 μm or more, more preferably 30 μm or more, and further preferably 50 μm or more. In addition, the thickness of the second substrate 2 is preferably 10 mm or less, more preferably 5 mm or less, and further preferably 3 mm or less.

[0060] (Wiring sheet)

[0061] The wiring sheet 10 has the wiring body 3, the first resin layer 4, and the pair of electrodes 5. The wiring sheet 10 is sandwiched between the first substrate 1 and the second substrate 2, and both faces of the wiring sheet 10 are protected by the first substrate 1 and the second substrate 2.

[0062] (Wiring body)

[0063] The wiring body 3 is a structure in which a plurality of electrically conductive linear bodies 31 are arranged at intervals from each other. In addition, the wiring body 3 is a structure in which the electrically conductive linear bodies 31 are arranged in multiple columns in parallel.

[0064] In a plan view of the laminate 100, the conductive linear member 31 can be linear, or can have a wave shape. As the wave shape, for example, a sine wave, a rectangular wave, a triangular wave, a sawtooth wave, or the like can be given. For example, when the wiring member 3 has such a structure, when the laminate 100 is stretched in the axial direction of the conductive linear member 31, the disconnection of the conductive linear member 31 can be suppressed.

[0065] The volume resistivity of the conductive linear member 31 is preferably 1.0 x 10 -9 Ω·m or more, more preferably 3.0 x 10 -9 Ω·m or more, further preferably 1.0 x 10 -8 Ω·m or more. In addition, the volume resistivity of the conductive linear member 31 is preferably 1.0 x 10 -3 Ω·m or less, more preferably 1.0 x 10 -4 Ω·m or less, further preferably 1.0 x 10 -5 Ω·m or less. When the volume resistivity of the conductive linear member 31 is in the above range, the surface resistance of the wiring member 3 can be easily reduced.

[0066] The volume resistivity of the conductive linear member 31 is measured as follows. The end portion and a portion 40 mm away from the end portion of the conductive linear member 31 are coated with silver paste, and the resistance of the end portion and the portion 40 mm away from the end portion is measured. Then, the cross-sectional area (unit: m 2 ) of the conductive linear member 31 is multiplied by the above-mentioned resistance value, and the obtained value is divided by the above-mentioned measured length (0.04 m), to calculate the volume resistivity of the conductive linear member 31.

[0067] The shape of the cross section of the conductive linear member 31 is not particularly limited, and can be a polygonal shape, a flat shape, an elliptical shape, a circular shape, or the like. From the viewpoint of matching with the first resin layer 4 or the like, the shape of the cross section of the conductive linear member 31 is preferably an elliptical shape or a circular shape.

[0068] In the case where the cross section of the conductive linear member 31 is circular, the diameter D (refer to Figure 2 ) of the conductive linear member 31 is preferably 3 μm or more and 200 μm or less. From the viewpoint of suppressing the increase in the sheet resistance and improving the heat generation efficiency and the insulation breakdown resistance of the laminate 100, the diameter D of the conductive linear member 31 is more preferably 4 μm or more, further preferably 5 μm or more. The diameter D of the conductive linear member 31 is more preferably 150 μm or less, further preferably 100 μm or less, particularly preferably 50 μm or less, and especially preferably 20 μm or less.

[0069] In the case where the cross section of the conductive linear member 31 is elliptical, the major axis is preferably in the same range as the above-mentioned diameter D.

[0070] For the diameter D of the electrically conductive linear bodies 31, the diameter of the electrically conductive linear bodies 31 was measured at five randomly selected points using a digital microscope, and the average value was taken.

[0071] The interval L of the electrically conductive linear bodies 31 (refer to Figure 2 ) is preferably 0.3 mm or more, more preferably 0.5 mm or more, further preferably 0.8 mm or more, and particularly preferably 1.5 mm or more. In addition, the interval L of the electrically conductive linear bodies 31 is preferably 50 mm or less, more preferably 30 mm or less, further preferably 20 mm or less, and particularly preferably 5 mm or less.

[0072] When the interval of the electrically conductive linear bodies 31 from each other is within the above range, since the electrically conductive linear bodies are somewhat densely arranged, the function of the laminate 100, which is to maintain the resistance of the wiring body 3 at a low level, is improved.

[0073] The interval L of the electrically conductive linear bodies 31 was measured as follows: the electrically conductive linear bodies 31 of the wiring body 3 were observed using a digital microscope, for example, and the interval between two adjacent electrically conductive linear bodies 31 was measured.

[0074] Note that the interval between two adjacent electrically conductive linear bodies 31 refers to the length in the direction in which the electrically conductive linear bodies 31 are arranged, and is the length between the opposing portions of the two electrically conductive linear bodies 31 (refer to Figure 2 ). In the case where the electrically conductive linear bodies 31 are arranged at unequal intervals, the interval L is the average of the intervals between all adjacent electrically conductive linear bodies 31.

[0075] The electrically conductive linear bodies 31 are not particularly limited in terms of the manner in which they are formed, and can be formed by etching, screen printing, inkjet, or the like, and can be linear bodies containing metal wires (hereinafter also referred to as "metal wire linear bodies"). Metal wires have high thermal conductivity, high electrical conductivity, and high workability. The metal wire linear bodies can greatly reduce the resistance, and even if the diameter of the metal wire linear bodies is extremely reduced, the current required for heating of the laminate 100 can be passed. Thus, the electrically conductive linear bodies 31 can be in a state that is not easily visually recognized. That is, when metal wire linear bodies are used as the electrically conductive linear bodies 31, the resistance value of the wiring body 3 can be reduced, and the light transmittance can be easily improved. In addition, the laminate 100 can easily achieve rapid heating. Furthermore, as described above, linear bodies with a fine diameter can be easily obtained.

[0076] Note that, as the electrically conductive linear bodies 31, in addition to metal wire linear bodies, linear bodies containing carbon nanotubes, and linear bodies in which a wire is covered with an electrically conductive material can be cited.

[0077] The metal wire linear shape can be a linear body formed of one metal wire, or a linear body formed by twisting a plurality of metal wires.

[0078] As the metal wire, a metal wire containing copper, aluminum, tungsten, iron, molybdenum, nickel, titanium, silver, gold, or the like, or an alloy containing two or more of these metals (for example, stainless steel, carbon steel, brass, phosphor bronze, zirconium copper alloy, beryllium copper, iron-nickel, nickel-chromium alloy, nickel-titanium, constantan, hastelloy, tungsten-rhenium, and the like) can be given. In addition, the metal wire can be plated with gold, tin, zinc, silver, nickel, chromium, nickel-chromium alloy, or solder, or the like, or the surface can be covered with a carbon material or a polymer, or the like, as described later. From the viewpoint of low volume resistivity, it is particularly preferable to contain one or more of tungsten and molybdenum, and alloys containing them.

[0079] As the metal wire, a metal wire covered with a carbon material can be given. When the metal wire is covered with a carbon material, the metallic luster is reduced, and the presence of the metal wire can be easily made inconspicuous. In addition, when the metal wire is covered with a carbon material, metal corrosion can also be suppressed.

[0080] As the carbon material covering the metal wire, amorphous carbon such as carbon black, activated carbon, hard carbon, soft carbon, mesoporous carbon, and carbon fiber; graphite, fullerene, graphene, and carbon nanotube can be given.

[0081] The conductive linear body 31 can be a linear body in which a filament is subjected to conductive covering. As the filament, a filament spun from a resin such as nylon or polyester, or the like, can be given. In addition, as the filament, a metal fiber, a carbon fiber, or a fiber of an ion conductive polymer, or the like, can be given. As the conductive covering, a film of a metal, a conductive polymer, or a carbon material, or the like, can be given. The conductive covering can be formed by plating or evaporation. The linear body in which the filament is subjected to conductive covering can increase the conductivity of the linear body while maintaining the softness of the filament. That is, the resistance of the wiring body 3 can be easily reduced.

[0082] (First resin layer)

[0083] The first resin layer 4 directly or indirectly supports the wiring body 3. In addition, by the first resin layer 4, the resistance value of the wiring body 3 can be stabilized. That is, by the first resin layer 4, the conductive linear body 31 can be fixed, and the contact of the conductive linear body 31 with the electrode 5 can be stabilized, and the resistance value can be less likely to increase.

[0084] From the viewpoint of stabilization of the resistance value of the wiring body 3, the storage modulus of the first resin layer 4 at 23°C is preferably 5.0 x 10 6 Pa or more and 1.0 x 10 10 Pa or less. From the same viewpoint, the storage modulus of the first resin layer 4 at 23°C is more preferably 5.0 x 10 7Pa or more, further preferably 5.0 x 10 8 Pa or more. The storage modulus at 23°C of the first resin layer is more preferably 7.0 x 10 9 Pa or less, further preferably 4.0 x 10 9 Pa or less.

[0085] In addition, from the same viewpoint, the storage modulus at 105°C of the first resin layer 4 is preferably 5.0 x 10 7 Pa or more, more preferably 5.0 x 10 8 Pa or more. The storage modulus at 105°C of the first resin layer 4 is preferably 7.0 x 10 9 Pa or less, more preferably 4.0 x 10 9 Pa or less.

[0086] Note that the storage modulus can be measured by the method described in the Examples below.

[0087] The thickness of the first resin layer 4 is not particularly limited. The thickness of the first resin layer 4 can be equal to or greater than the diameter D of the conductive linear body 31, or can be less than the diameter D of the conductive linear body 31. If the thickness of the first resin layer 4 is equal to or greater than the diameter D of the conductive linear body 31, the wiring body 3 can be contained in the first resin layer 4. In the case where the thickness of the first resin layer 4 is less than the diameter D of the conductive linear body 31, the wiring body 3 is exposed from the first resin layer 4. In addition, in the case where the wiring body 3 is exposed from the first resin layer 4, the wiring body 3 can be exposed on the first substrate 1 side, or can be exposed on the second substrate 2 side. The thickness of the first resin layer 4 is preferably 1 μm or more, more preferably 5 μm or more, further preferably 10 μm or more. The thickness of the first resin layer 4 is preferably 100 μm or less, more preferably 50 μm or less, further preferably 30 μm or less.

[0088] From the viewpoint of setting the storage modulus within the above range, the first resin layer 4 is preferably a layer formed of a cured product of a curable adhesive.

[0089] As the curable adhesive, a thermosetting adhesive that is cured by heat, an energy ray-curable adhesive, and the like can be given. As the energy ray, ultraviolet rays, visible energy rays, infrared rays, electron beams, and the like can be given. Note that "energy ray curing" also includes thermal curing based on heating using an energy ray.

[0090] The curable adhesive preferably contains a thermosetting resin. As the thermosetting resin, there is no particular limitation, and specific examples that can be given include: epoxy resins, phenol resins, melamine resins, urea resins, polyester resins, urethane resins, acrylic resins, benzocyclobutene resins, and the like. Zine resins, phenoxy resins, amine compounds, and acid anhydride compounds, and the like. These can be used singly or in combination of two or more. Among them, from the viewpoint of being suitable for curing using an imidazole-based curing catalyst, it is preferable to use an epoxy resin, a phenol resin, a melamine resin, a urea resin, an amine compound, and an acid anhydride compound, and from the viewpoint of exhibiting excellent curing properties, it is particularly preferable to use an epoxy resin; a phenol resin; a mixture thereof; or a mixture of an epoxy resin and at least one selected from a phenol resin, a melamine resin, a urea resin, an amine compound, and an acid anhydride compound, and it is preferable to use an epoxy resin.

[0091] As the epoxy resin, from the viewpoint of improving the storage modulus of the first resin layer 4, it is preferable to be a cyclic resin such as an aromatic epoxy resin or an alicyclic epoxy resin. An epoxy resin having a softness segment such as an oxyalkylene chain has a tendency to reduce the storage modulus of the first resin layer 4.

[0092] The energy ray-curable adhesive preferably contains an energy ray-curable resin. As the energy ray-curable resin, there can be mentioned, for example, a compound having at least one polymerizable double bond in the molecule, and it is preferable to be an acrylate compound having a (meth)acryloyl group.

[0093] As the acrylate compound, there can be mentioned, for example, dicyclopentadiene diacrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol mono-hydroxy penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate, and the like containing a chain aliphatic skeleton; dicyclopentyl di(meth)acrylate, and the like containing a cyclic aliphatic skeleton; polyalkylene glycol (meth)acrylate; oligoester (meth)acrylate, urethane (meth)acrylate oligomer, epoxy-modified (meth)acrylate, polyether (meth)acrylate other than polyalkylene glycol (meth)acrylate, itaconic acid oligomer, and the like.

[0094] The weight average molecular weight (Mw) of the energy ray-curable resin is preferably 100 or more, and more preferably 300 or more. In addition, the weight average molecular weight is preferably 30,000 or less, and more preferably 10,000 or less. Note that the weight average molecular weight in the present specification is a value converted to standard polystyrene by a gel permeation chromatography (GPC) method.

[0095] The energy-curable resin containing the binder can be a single type or two or more. When there are two or more energy-curable resins, their combination and ratio can be arbitrarily chosen.

[0096] When using energy-curable resins or thermosetting resins, photopolymerization initiators and thermal polymerization initiators are preferred. By using photopolymerization initiators and thermal polymerization initiators, the polymerization reaction of the curable resin can be easily initiated, and the control of the curing reaction becomes easier.

[0097] Examples of photopolymerization initiators include: benzophenone, acetophenone, benzoin, benzoin methyl ether, 2,4-diethylthioxanthone, 1-hydroxycyclohexylphenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, 2-chloroanthraquinone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, etc.

[0098] In addition to photoradical polymerization initiators, photocationic polymerization initiators can also be cited as photopolymerization initiators. Photocationic polymerization initiators are compounds that initiate the curing reaction of cationic curable compounds by generating cationic substances through irradiation with energy rays. They consist of a cationic portion that absorbs energy rays and an anionic portion that becomes the source of acid generation.

[0099] Examples of photocationic polymerization initiators include: sulfonium salts and iodine. Salt compounds, Salt compounds, ammonium salt compounds, antimony salt compounds, diazonium salt compounds, selenium salt compounds, oxygen Salt compounds, bromide compounds, etc. Among them, from the viewpoint of excellent compatibility and excellent storage stability of the obtained adhesive, sulfonium salt compounds are preferred, and aromatic sulfonium salt compounds having aromatic groups are more preferred.

[0100] Examples of sulfonium salts include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, and triphenylsulfonium tetra(pentafluorophenyl)borate.

[0101] As iodine Salt compounds, for example: diphenyliodine Tetra(pentafluorophenyl)borate, diphenyliodide Hexafluorophosphate and (triisopropylphenyl)iodine Tetra(pentafluorophenyl)borate, etc.

[0102] As Salt compounds, for example, tri-n-butyl(2,5-dihydroxyphenyl) bromide benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, and the like. and the like.

[0103] As the ammonium salt compound, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, and the like can be given.

[0104] As the antimonate compound, triphenylsulfonium hexafluoroantimonate, p-(phenylthio)phenyldiphenylsulfonium hexafluoroantimonate, and diallyl iodonium hexafluoroantimonate can be given. hexafluoroantimonate, and the like.

[0105] As the thermal polymerization initiator, hydrogen peroxide; persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate; azo compounds such as 2,2'-azobis(2-amidinopropane) dihydrochloride, 4,4'-azobis(4-cyanopentanoic acid), 2,2'-azobisisobutyronitrile, and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile); and organic peroxides such as benzoyl peroxide, lauroyl peroxide, peroxyacetic acid, peroxy succinic acid, di-t-butyl peroxide, t-butyl hydroperoxide, and cumene hydroperoxide, and the like thermal radical polymerization initiators can be given.

[0106] In addition, as the thermal polymerization initiator, in addition to the above-mentioned thermal radical polymerization initiators, a thermal cationic polymerization initiator can be given. The thermal cationic polymerization initiator is a compound which can generate a cationic substance which initiates polymerization by heating. As the thermal cationic polymerization initiator, sulfonium salts, quaternary ammonium salts, diazonium salts, iodonium salts, and the like can be given. Among these, from the viewpoints of easy availability, and easiness to obtain more excellent adhesion and transparency, and the like, a sulfonium salt is preferred. hexafluoroantimonate, and the like. hexafluoroantimonate, and the like.

[0107] As the sulfonium salt, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, and triphenylsulfonium hexafluoroarsenate can be given.

[0108] As the quaternary ammonium salt, tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, and tetrabutylammonium hydrogen sulfate can be given.

[0109] As the diazonium salt, benzene diazonium chloride can be given. hexafluoroantimonate, and the like. hexafluoroantimonate, and the like. hexafluoroantimonate, and the like.

[0110] As the iodonium salt, diphenyl iodonium hexafluoroarsenate, bis(4-chlorophenyl) iodonium hexafluoroarsenate, and phenyl(4-methoxyphenyl) iodonium hexafluoroarsenate can be given. hexafluoroantimonate, and the like. hexafluoroantimonate, and the like. hexafluoroantimonate, and the like. hexafluoroantimonate, and the like.

[0111] These polymerization initiators can be used singly or in combination of two or more.

[0112] In the case where these polymerization initiators are used to form a crosslinked structure, the amount of use thereof is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 0.5 parts by mass or more and 20 parts by mass or less, and particularly preferably 1 part by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the energy ray-curable resin or the thermosetting resin.

[0113] In addition, in the case where the thermosetting resin is used, a curing catalyst such as an imidazole-based curing catalyst can also be used.

[0114] In the present embodiment, the curable adhesive can contain, together with the energy ray-curable resin or the thermosetting resin, a softness adjusting component for making it easy to maintain the sheet shape before curing. As the polymer used as the softness adjusting component, a phenoxy resin, a polyolefin-based resin or a modified product thereof, a polyamide-imide resin, a polyimide resin, a rubber-based resin, and an acrylic resin, and the like can be mentioned.

[0115] These softness adjusting components can be used singly or in combination of two or more.

[0116] In the case where the curable adhesive used in the present embodiment contains the softness 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 further preferably 60 parts by mass or more and 200 parts by mass or less, relative to 100 parts by mass of the softness adjusting component, from the viewpoint of adjusting the storage modulus of the first resin layer 4 to the above range. In the case where the adhesive contains the energy ray-curable resin or the thermosetting resin and does not contain the softness adjusting component, there is a tendency that the storage modulus of the first resin layer 4 becomes too high.

[0117] In the present embodiment, the curable adhesive preferably does not contain a filler material. In the case where the adhesive does not contain the filler material, it is possible to prevent the storage modulus of the first resin layer 4 at 23°C from becoming too high.

[0118] However, in the range where it is possible to adjust the storage modulus of the first resin layer 4 at 23°C to the above range, the curable adhesive can also contain the filler material.

[0119] As the filler material, for example, inorganic powders such as silicon dioxide, aluminum oxide, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride; beads obtained by spheroidizing the inorganic powders; single crystal fibers; and glass fibers can be given. Among them, silicon dioxide filler and aluminum oxide filler are preferable. The filler material can be used singly or in combination of two or more.

[0120] Other components can also be contained in the curable adhesive. As the other components, for example, known additives such as organic solvents, coupling agents, flame retardants, tackifiers, ultraviolet absorbers, antioxidants, preservatives, antifungal agents, plasticizers, defoaming agents, and wetting property adjusting agents can be given.

[0121] (Electrode)

[0122] The electrode 5 is used to supply electric current to the conductive linear body 31. The electrode 5 is a pair. The electrode 5 is in direct contact with the conductive linear body 31. Further, the electrode 5 is arranged so as to be electrically connected to both end portions of the conductive linear body 31.

[0123] The electrode 5 can be formed using a known electrode material. As the electrode material, for example, conductive paste such as silver paste, metal foil such as copper foil, and metal wire can be given. In the case where the electrode material is a metal wire, the metal wire can be one, and preferably two or more.

[0124] In the case where the electrode material is a metal foil or a metal wire, as the metal of the metal foil or the metal wire, for example, 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, nickel-chromium alloy, nickel-titanium, constantan alloy, hastelloy, and tungsten-rhenium can be given. In addition, the metal foil or the metal wire can be a material plated with gold, tin, zinc, silver, nickel, chromium, nickel-chromium alloy, or solder.

[0125] The width of at least one of the electrodes 5 is preferably 10 mm or less, and more preferably 3 mm or less, when the laminate 100 is viewed in plan. In addition, the width of the electrode is preferably 0.1 mm or more, and more preferably 0.5 mm or more. Note that, in the case where at least one of the electrodes is a metal wire, the width of the electrode is the diameter of the metal wire, and in the case where two or more metal wires are used, the width of one electrode refers to the sum of the diameters of the respective metal wires.

[0126] The thickness of the electrode 5 is preferably 2 μm or more, more preferably 5 μm or more, and further preferably 10 μm or more. The thickness of the electrode 5 is preferably 200 μm or less, more preferably 100 μm or less, further preferably 50 μm or less, and particularly preferably 25 μm or less. When the thickness of the electrode 5 is within the above range, the electrical conductivity becomes high and the electrical resistance becomes low, and thus the electrical resistance value of the sheet-like structure can be suppressed to a low level. Also, sufficient strength can be obtained as the electrode. Note that, in the case where the electrode is a metal wire, the thickness of the electrode is the diameter of the metal wire.

[0127] (Second resin layer)

[0128] The second resin layer 6 is provided between the first substrate 1 or the second substrate 2 and the wiring sheet 10. The storage modulus of the second resin layer 6 is lower than that of the first resin layer 4. With the second resin layer 6, the second substrate 2 can be prevented from being broken. In the present embodiment, the second substrate 2 and the wiring sheet 10 are laminated with the second resin layer 6 interposed therebetween.

[0129] From the viewpoint of preventing breakage, the storage modulus of the second resin layer 6 at 23°C is preferably 1.0 x 10 4 Pa or more and 3.0 x 10 5 Pa or less. From the same viewpoint, the storage modulus of the second resin layer 6 at 23°C is more preferably 4.0 x 10 4 Pa or more, and further preferably 8.0 x 10 4 Pa or more. The storage modulus of the second resin layer 6 at 23°C is more preferably 2.5 x 10 5 Pa or less, and further preferably 2.0 x 10 5 Pa or less.

[0130] From the same viewpoint, the storage modulus of the second resin layer 6 at 105°C is preferably 5.0 x 10 3 Pa or more, and more preferably 1.0 x 10 4 Pa or more. The storage modulus of the second resin layer 6 at 105°C is preferably 4.0 x 10 4 Pa or less, and more preferably 3.0 x 10 4 Pa or less.

[0131] Note that the storage modulus can be measured by the method described in the Examples below.

[0132] The thickness of the second resin layer 6 is not particularly limited. The thickness of the second resin layer 6 is preferably 1 μm or more, more preferably 5 μm or more, and further preferably 10 μm or more. The thickness of the second resin layer 6 is preferably 1000 μm or less, more preferably 500 μm or less, and further preferably 300 μm or less.

[0133] From the viewpoint of excellent performance as an adhesive layer, and the viewpoint of setting the storage modulus within the above range, the second resin layer 6 is preferably an adhesive layer described below.

[0134] The adhesive layer can be constituted by an adhesive obtained by crosslinking (thermally crosslinking) an adhesive composition (hereinafter sometimes referred to as "adhesive composition P") containing, for example, a (meth)acrylate polymer (A) and a crosslinking agent (B), or an energy ray-curable component (C), or both. Note that the adhesive composition P preferably further contains a photopolymerization initiator (D) as desired. In the present specification, (meth)acrylic acid refers to both acrylic acid and methacrylic acid. The same applies to other similar terms. Furthermore, the concept of "copolymer" is also included in "polymer".

[0135] In the case where the adhesive composition P contains the energy ray-curable component (C), the adhesive layer obtained by crosslinking the adhesive composition P has not yet been cured by energy rays at the stage of the adhesive sheet, that is, at the stage before being attached to the adherend, and has a low storage modulus. Therefore, it is possible to moderate the stress generated when being attached to the adherend. Thus, even in the case where the adhesive layer is attached to a surface of the adherend having unevenness, the adhesive layer easily follows the unevenness, and it is possible to suppress the generation of gaps, lifting, and the like in the vicinity of the unevenness, and to exhibit excellent attachability to the adherend.

[0136] As monomer units constituting the (meth)acrylate polymer (A), it is preferable to contain an alkyl (meth)acrylate, and a monomer having a reactive functional group within the molecule (monomer containing a reactive functional group).

[0137] The (meth)acrylate polymer (A) can exhibit preferable adhesiveness by containing an alkyl (meth)acrylate as a monomer unit constituting the polymer. As the alkyl (meth)acrylate, it is preferable to use an alkyl (meth)acrylate having 1 to 20 carbon atoms in the alkyl group. The alkyl group can be linear or branched, and can have a cyclic structure.

[0138] As the (meth)acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group, there are exemplified (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid propyl ester, (meth)acrylic acid n-butyl ester, (meth)acrylic acid n-pentyl ester, (meth)acrylic acid n-hexyl ester, (meth)acrylic acid 2-ethylhexyl ester, (meth)acrylic acid iso-octyl ester, (meth)acrylic acid n-decyl ester, (meth)acrylic acid n-dodecyl ester, (meth)acrylic acid myristyl ester, (meth)acrylic acid palmityl ester, (meth)acrylic acid stearyl ester, (meth)acrylic acid cyclohexyl ester, (meth)acrylic acid isobornyl ester, (meth)acrylic acid adamantyl ester, and the like. These can be used alone or in combination of two or more.

[0139] As the (meth)acrylic acid alkyl ester, (meth)acrylic acid alkyl ester having 4 to 20 carbon atoms in the alkyl group is preferable. As the (meth)acrylic acid alkyl ester having 4 to 20 carbon atoms in the alkyl group, (meth)acrylic acid n-butyl ester, (meth)acrylic acid 2-ethylhexyl ester, (meth)acrylic acid iso-octyl ester, (meth)acrylic acid isobornyl ester, and the like are preferable, and from the viewpoint of obtaining excellent adhesiveness, (meth)acrylic acid n-butyl ester, (meth)acrylic acid 2-ethylhexyl ester, and (meth)acrylic acid isobornyl ester, and the like are more preferable, and (meth)acrylic acid n-butyl ester, (meth)acrylic acid 2-ethylhexyl ester, and (meth)acrylic acid isobornyl ester, and the like are particularly preferable.

[0140] As the monomer units constituting the (meth)acrylic ester polymer (A), it is preferable to contain (meth)acrylic acid alkyl ester 40% by mass or more, more preferable to contain 50% by mass or more, further preferable to contain 60% by mass or more, and particularly preferable to contain 70% by mass or more. When (meth)acrylic acid alkyl ester is contained 40% by mass or more, the (meth)acrylic ester polymer (A) can exhibit appropriate adhesiveness. Further, as the monomer units constituting the (meth)acrylic ester polymer (A), it is preferable to contain (meth)acrylic acid alkyl ester 99% by mass or less, particularly preferable to contain 95% by mass or less, and further preferable to contain 90% by mass or less. By setting the above (meth)acrylic acid alkyl ester to 99% by mass or less, other monomer components can be introduced into the (meth)acrylic ester polymer (A) in an appropriate amount. Particularly, in the case where the (meth)acrylic ester polymer (A) contains a hydroxyl group-containing monomer as a monomer constituting the polymer, it is preferable that the (meth)acrylic ester polymer (A) contain (meth)acrylic acid alkyl ester as a monomer unit constituting the polymer 87% by mass or less, and further preferable to contain 83% by mass or less.

[0141] The (meth)acrylate polymer (A) can form a crosslinked structure (three-dimensional network structure) by the reaction of the reactive functional group derived from the monomer containing a reactive functional group with the crosslinking agent (B) described later, and a pressure-sensitive adhesive having desired cohesive force can be obtained.

[0142] As the monomer containing a reactive functional group contained as a monomer unit constituting the (meth)acrylate polymer (A), a monomer having a hydroxyl group in the molecule (hydroxyl group-containing monomer), a monomer having a carboxyl group in the molecule (carboxyl group-containing monomer), and a monomer having an amino group in the molecule (amino group-containing monomer), and the like can be preferably selected. These monomers containing a reactive functional group can be used alone or in combination of two or more.

[0143] Among the monomers containing a reactive functional group, from the viewpoint of ease of adjustment of crosslinking density and easy obtainment of a pressure-sensitive adhesive having desired cohesive force, a hydroxyl group-containing monomer or a carboxyl group-containing monomer is preferred, and from the viewpoint of adhesion and moisture heat whitening resistance, a hydroxyl group-containing monomer is preferred.

[0144] As the hydroxyl group-containing monomer, for example, (meth)acrylic acid 2-hydroxyethyl ester, (meth)acrylic acid 2-hydroxypropyl ester, (meth)acrylic acid 3-hydroxypropyl ester, (meth)acrylic acid 2-hydroxybutyl ester, (meth)acrylic acid 3-hydroxybutyl ester, (meth)acrylic acid 4-hydroxybutyl ester, and the like (hydroxyalkyl (meth)acrylate) can be mentioned. Among them, a hydroxyalkyl (meth)acrylate having a hydroxyalkyl group having a carbon number of 1 to 4 is preferred. Specifically, for example, (meth)acrylic acid 2-hydroxyethyl ester, (meth)acrylic acid 4-hydroxybutyl ester, and the like can be preferably selected, and in particular, 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate can be preferably selected. These can be used alone or in combination of two or more.

[0145] As the carboxyl group-containing monomer, for example, acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid, and the like (ethylenically unsaturated carboxylic acid) can be mentioned. Among them, from the viewpoint of the cohesive force of the obtained (meth)acrylate polymer (A), acrylic acid is preferred. These can be used alone or in combination of two or more.

[0146] For the (meth)acrylate polymer (A), as the monomer units constituting the polymer, it is preferable to contain 1% by mass or more of the reactive functional group-containing monomer, more preferable to contain 3% by mass or more, and further preferable to contain 5% by mass or more. In the case where the reactive functional group-containing monomer is a hydroxyl group-containing monomer, it is preferable to contain 5% by mass or more, more preferable to contain 8% by mass or more, and further preferable to contain 10% by mass or more. In addition, in the case where the reactive functional group-containing monomer is a hydroxyl group-containing monomer, it is preferable to be less than 25% by mass, more preferable to be 20% by mass or less, and further preferable to be 16% by mass or less. In addition, for the (meth)acrylate polymer (A), as the monomer units constituting the polymer, it is preferable to contain 50% by mass or less of the reactive functional group-containing monomer, more preferable to contain 40% by mass or less, and further preferable to contain 30% by mass or less.

[0147] In addition, the (meth)acrylate polymer (A) preferably contains a nitrogen atom-containing monomer as the monomer unit constituting the polymer. By having the nitrogen atom-containing monomer exist as a constituting unit in the polymer, a given polarity can be imparted to the adhesive, and the affinity is excellent even for an adherend such as glass that has a certain degree of polarity. As the nitrogen atom-containing monomer, in addition to the amino group-containing monomer as the above-described reactive functional group-containing monomer, a monomer having an amide group, a monomer having a nitrogen-containing heterocycle, and the like can be given. Among these, from the viewpoint of imparting moderate rigidity to the (meth)acrylate polymer (A), a monomer having a nitrogen-containing heterocycle is preferable.

[0148] Note that, as the nitrogen atom-containing monomer, for example, N-vinyl carboxylic acid amide, (meth)acrylamide, N-methyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-t-butyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-ethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-phenyl (meth)acrylamide, dimethylaminopropyl (meth)acrylamide, N-vinyl caprolactam, and the like can be used.

[0149] These nitrogen atom-containing monomers can be used alone or in combination of two or more.

[0150] As the monomer having a nitrogen-containing heterocycle, for example, N- (methyl) acryloyl morpholine, N-vinyl-2-pyrrolidone, N- (methyl) acryloyl pyrrolidine, N- (methyl) acryloyl piperidine, N- (methyl) acryloyl pyrrolidine, N- (methyl) acryloyl aziridine, aziridinylethyl (methyl) acrylate, 2-vinylpyridine, 4-vinylpyridine, 2-vinylpyrazine, 1-vinylimidazole, N-vinylcarbazole, N-vinylphthalimide, and the like can be given, of which N- (methyl) acryloyl morpholine is preferable in that it imparts more excellent adhesion, and N-acryloylmorpholine is particularly preferable.

[0151] In the case where the (meth)acrylate polymer (A) contains a monomer having a nitrogen-containing heterocycle as a monomer unit constituting the polymer, it is preferable to contain the nitrogen atom-containing monomer in an amount of 0.5% by mass or more, more preferably 1% by mass or more, and further preferably 3% by mass or more. In addition, it is preferable for the (meth)acrylate polymer (A) to contain the monomer having a nitrogen-containing heterocycle as a monomer unit constituting the polymer in an amount of 20% by mass or less, more preferably 15% by mass or less, and further preferably 8% by mass or less. When the content of the monomer having a nitrogen-containing heterocycle is within the above range, the obtained adhesive can effectively exhibit excellent adhesion to a glass or the like to be bonded.

[0152] The (meth)acrylate polymer (A) can contain other monomers as monomer units constituting the polymer, as desired. As the other monomers, for example, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, and the like (alkoxyalkyl (meth)acrylate), vinyl acetate, and styrene, and the like can be given. These can be used alone or in combination of two or more.

[0153] The (meth)acrylate polymer (A) is preferably a linear polymer. By being a linear polymer, entanglement of molecular chains is easily induced, and an increase in cohesive force can be expected, and a more excellent adhesive can be obtained.

[0154] The (meth)acrylate polymer (A) can be a random copolymer or a block copolymer.

[0155] The weight average molecular weight of the (meth)acrylate polymer (A) is preferably 200,000 or more, more preferably 300,000 or more, and further preferably 400,000 or more. When the lower limit value of the weight average molecular weight of the (meth)acrylate polymer (A) is the above, the long-term durability of the second resin layer and the laminate becomes excellent.

[0156] In addition, the weight average molecular weight of the (meth)acrylate polymer (A) is preferably 2 million or less, more preferably 1.5 million or less, further preferably 1 million or less, and particularly preferably 800,000 or less. When the upper limit of the weight average molecular weight of the (meth)acrylate polymer (A) is as described above, at least one of the adhesion and the close contact of the obtained adhesive to the adherend becomes more excellent.

[0157] Note that, in the adhesive composition P, one kind of (meth)acrylate polymer (A) can be used alone, or two or more kinds thereof can be used in combination.

[0158] The crosslinking agent (B) crosslinks the (meth)acrylate polymer (A) by heating the adhesive composition P, and forms a three-dimensional network structure favorably. Thus, the cohesion of the obtained adhesive is further improved.

[0159] As the crosslinking agent (B), any one can be used as long as it reacts with the reactive functional group possessed by the (meth)acrylate polymer (A). Examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amine-based crosslinking agents, melamine-based crosslinking agents, aziridine-based crosslinking agents, hydrazine-based crosslinking agents, aldehyde-based crosslinking agents, oxazoline-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, and ammonium salt-based crosslinking agents. Among them, in the case where the reactive functional group possessed by the (meth)acrylate polymer (A) is a hydroxyl group, an isocyanate-based crosslinking agent having high reactivity with a hydroxyl group is preferably used, and in the case where the reactive functional group possessed by the (meth)acrylate polymer (A) is a carboxyl group, an epoxy-based crosslinking agent having high reactivity with a carboxyl group is preferably used. Note that, one kind of crosslinking agent (B) can be used alone, or two or more kinds thereof can be used in combination.

[0160] The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. As the polyisocyanate compound, aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate; and adducts thereof as reaction products with low-molecular active-hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil; and biuret and isocyanurate bodies thereof can be given. Among them, from the viewpoint of the reactivity with a hydroxyl group, a trimethylolpropane-modified aromatic polyisocyanate is preferable, and at least one of trimethylolpropane-modified toluene diisocyanate and trimethylolpropane-modified xylylene diisocyanate is particularly preferably used.

[0161] ​As the epoxy crosslinking agent, 1, 3-bis (N, N-diglycidyl aminomethyl) cyclohexane, N, N, N', N'-tetraglycidyl-m-xylylenediamine, ethylene glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, and diglycidyl amine, and the like can be given. Among them, from the viewpoint of the reactivity with the carboxyl group, 1, 3-bis (N, N-diglycidyl aminomethyl) cyclohexane is preferable.

[0162] The content of the crosslinking agent (B) in the adhesive composition P is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and further preferably 0.1 parts by mass or more, relative to 100 parts by mass of the (meth) acrylate polymer (A). In addition, the content is preferably 3 parts by mass or less, more preferably 2 parts by mass or less, and further preferably 1 part by mass or less. By setting the content of the crosslinking agent (B) within the above range, the degree of crosslinking becomes moderate, and it becomes more excellent in adjusting the storage modulus to an appropriate value for the obtained adhesive.

[0163] By containing the energy ray-curable component (C) in the adhesive composition P, the adhesive obtained by crosslinking (thermally crosslinking) the adhesive composition P becomes an energy ray-curable adhesive. By the curing based on the energy ray irradiation after being attached to the adherends, the energy ray-curable components (C) polymerize with each other, and it is presumed that the polymerized energy ray-curable components (C) are entangled in the crosslinked structure (three-dimensional network structure) of the (meth) acrylate polymer (A). The adhesive having such a higher structure has high cohesion, and exhibits high film strength.

[0164] The energy ray-curable component (C) is not particularly limited as long as it is a component that is cured by the irradiation of an energy ray and the above effects are obtained, and can be any one of a monomer, an oligomer, or a polymer, or a mixture thereof. Among them, a multifunctional acrylate monomer that is excellent in compatibility with the (meth) acrylate polymer (A) or the like can be preferably given.

[0165] As the multifunctional acrylate monomer, 2-functional types such as tricyclodecane dimethanol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentadiene di(meth)acrylate, caprolactone-modified dicyclopentadiene di(meth)acrylate, oxirane-modified phosphoric acid di(meth)acrylate, bis(acryloyloxyethyl) isocyanurate, allylated cyclohexyl di(meth)acrylate, ethoxylated bisphenol A diacrylate, and 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene; 3-functional types such as trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloyloxyethyl) isocyanurate, and ε-caprolactone-modified tris-(2-(meth)acryloyloxyethyl) isocyanurate; 4-functional types such as diglycerol tetra(meth)acrylate and pentaerythritol tetra(meth)acrylate; 5-functional types such as propionic acid-modified dipentaerythritol penta(meth)acrylate; and 6-functional types such as dipentaerythritol hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate, and the like can be mentioned. Of these, at least one of ε-caprolactone-modified tris-(2-(meth)acryloyloxyethyl) isocyanurate and tricyclodecane dimethanol di(meth)acrylate is preferably used. These can be used singly or in combination of two or more. In addition, from the viewpoint of compatibility with the (meth)acrylate polymer (A), the multifunctional acrylate monomer preferably has a molecular weight of less than 1000.

[0166] With respect to the obtained adhesive, from the viewpoint of easily setting the storage modulus described above to a desired value, the content of the energy ray-curable component (C) in the adhesive composition P is preferably 1 part by mass or more, more preferably 2 parts by mass or more, further preferably 3 parts by mass or more, and particularly preferably 5 parts by mass or more, with respect to 100 parts by mass of the (meth)acrylate polymer (A). On the other hand, from the viewpoint of preventing phase separation of the energy ray-curable component (C) from the (meth)acrylate polymer (A) and the viewpoint of easily setting the storage modulus described above to a desired value, the content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, further preferably 20 parts by mass or less, and particularly preferably 7.5 parts by mass or less.

[0167] In the case where ultraviolet rays are used as the energy rays for curing the energy ray-curable adhesive, the adhesive composition P preferably further contains a photopolymerization initiator (D). By thus containing the photopolymerization initiator (D), the energy ray-curable component (C) can be efficiently polymerized, and the polymerization curing time and the amount of irradiation of the energy rays can be reduced.

[0168] As the photopolymerization initiator (D), mention can be made of benzophenone, phenylethanone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin benzoic acid methyl ester, benzoin dimethyl ether, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzil, benzpinacol, acetyl, β-chloroanthraquinone, 4-(2-hydroxyethoxy)-phenyl (2-hydroxy-2-propyl) ketone, 2-benzothiazole-N,N-diethyl dithio carbamate, 2,4,6-trimethylbenzoyl diphenyl phosphine oxide, and bis (2,4,6-trimethylbenzoyl) phenyl phosphine oxide, and the like. These can be used alone or in combination of two or more.

[0169] The content of the photopolymerization initiator (D) in the adhesive composition P is preferably 0.1 parts by mass or more, more preferably 1.0 parts by mass or more, and further preferably 5.0 parts by mass or more, relative to 100 parts by mass of the energy ray-curable component (C). In addition, the content is preferably 35 parts by mass or less, more preferably 25 parts by mass or less, and further preferably 15 parts by mass or less. When the content of the photopolymerization initiator (D) is within this range, the photopolymerization initiator (D) can be cleaved without problems at the time of irradiation of the energy rays, and the curability of the energy ray-curable component (C) is further improved. In addition, the storage modulus described above is easily satisfied.

[0170] In the adhesive composition P, various additives generally used in acrylic adhesives can be used as desired. As the various additives, mention can be made of a silane coupling agent, an antistatic agent, an adhesion-improving agent, an antioxidant, a light stabilizer, a softening agent, a filler, and a refractive index adjusting agent, and the like.

[0171] (Method for manufacturing the laminate)

[0172] The method for manufacturing the laminate 100 of the present embodiment is not particularly limited. The laminate 100 can be manufactured, for example, by the following procedures.

[0173] First, a process of producing a wiring body film provided with the wiring body 3 is performed. In this process, a coating film is formed by applying a thermally curable adhesive for forming the first resin layer 4 on a release film. Next, the coating film is dried to produce an adhesive layer. Next, the conductive linear bodies 31 are arranged and disposed on the adhesive layer to form the wiring body 3. For example, in a state where the adhesive layer with the release film is disposed on the outer circumferential surface of a drum member, the conductive linear bodies 31 are wound on the adhesive layer in a spiral shape while rotating the drum member. Then, the bundle of the conductive linear bodies 31 wound in a spiral shape is cut along the axial direction of the drum member. Thus, the wiring body 3 is formed and disposed on the adhesive layer. In this way, a wiring body film in which the wiring body 3 is formed on the adhesive layer with the release film is obtained. According to this method, for example, by moving the feeding portion of the conductive linear bodies 31 in a direction parallel to the axis of the drum member while rotating the drum member, the interval L of the adjacent conductive linear bodies 31 in the wiring body 3 can be easily adjusted.

[0174] Next, a process of providing the pair of electrodes 5 on the first substrate 1 is performed. In this process, the pair of electrodes 5 can be provided by, for example, printing a conductive paste or the like on the first substrate 1 at a given arrangement and performing drying or the like.

[0175] Next, a process of disposing the wiring body film on the first substrate 1 provided with the pair of electrodes 5 and curing the thermally curable adhesive is performed. In this process, the wiring body film is laminated on the first substrate 1 provided with the pair of electrodes 5 in such a manner that the pair of electrodes 5 contacts both end portions of the conductive linear bodies 31 in the wiring body 3 of the wiring body film. Then, after the release film is peeled off, the first resin layer 4 is formed by subjecting the thermally curable adhesive to a given heat treatment, and the wiring sheet 10 is formed on the first substrate 1.

[0176] On the other hand, a process of preparing a protective film provided with the second substrate 2 and the second resin layer 6 is performed. In this process, the adhesive composition P for forming the second resin layer 6 is applied on the second substrate 2 to form a coating film, and the protective film is produced. Note that, as shown in Figs. 1 and 2, two holes are preferably provided in the second substrate 2. Figure 1 and Figure 2

[0177] Next, a process of disposing the protective film on the first substrate 1 provided with the wiring sheet 10 and cross-linking the adhesive composition P is performed. In this process, the protective film is laminated on the first substrate 1 provided with the wiring sheet 10 in such a manner that the two holes of the protective film overlap the pair of electrodes 5 in a plan view and in such a manner that the coating film of the adhesive composition P of the protective film contacts the wiring sheet 10. Then, the second resin layer 6 is formed by subjecting the coating film of the adhesive composition P to a given energy ray irradiation, and the laminate 100 is produced. ​

[0178] (Action and effect of the first embodiment)

[0179] According to the present embodiment, the following action and effect can be exerted.

[0180] (1) According to the present embodiment, since the second resin layer 6 has a low storage modulus, it is easily deformed. Therefore, in the case where the laminate 100 becomes high temperature, by deforming the second resin layer 6, the strain generated in the second substrate 2 can be alleviated. Thereby, it is possible to prevent the second substrate 2 from being broken.

[0181] (2) According to the present embodiment, by setting the storage modulus of the second resin layer 6 at 23°C to 1.0 x 10 4 Pa or more and 3.0 x 10 5 Pa or less, the second resin layer 6 is easily deformed, and the strain generated in the second substrate 2 can be alleviated.

[0182] (3) According to the present embodiment, by the first resin layer 4, the conductive linear body 31 can be fixed, the deformation in the thickness direction of the inside of the laminate 100 can be suppressed, the contact of the conductive linear body 31 with the electrode 5 can be stabilized, and the resistance value of the wiring body 3 can be stabilized.

[0183] (4) According to the present embodiment, by setting the storage modulus of the first resin layer 4 at 23°C to 5.0 x 10 6 Pa or more and 1.0 x 10 10 Pa or less, in the case where the laminate 100 is applied with deformation, the connection portion of the conductive linear body 31 with the electrode 5 can be prevented from being broken, and the conductive linear body 31 can be fixed.

[0184] (5) The laminate 100 of the present embodiment can be manufactured in a relatively simple manner by the above-described manufacturing method of the laminate.

[0185] [Second embodiment]

[0186] Next, the second embodiment of the present application will be described based on the drawings. The present application is not limited to the content of the present embodiment. Note that in the drawings, there are parts that are enlarged or reduced to be illustrated for easy explanation.

[0187] In the second embodiment, in the cross-sectional view of the laminate 100A, the first substrate 1 and the wiring sheet 10 are laminated with the second resin layer 6 interposed therebetween, which is different from the first embodiment.

[0188] In the following description, mainly the parts different from the first embodiment will be described, and the repeated description will be omitted or simplified. The same signs are marked to the same configuration as the first embodiment, and the description thereof will be omitted or simplified.

[0189] As Figure 3 shown in FIG. 1, the laminate 100A of the present embodiment includes a first substrate 1, a second substrate 2 having a higher linear expansion coefficient than the first substrate 1, and a wiring sheet 10 interposed between the first substrate 1 and the second substrate 2. Further, the wiring sheet 10 includes a plurality of conductive linear bodies 31 arranged at intervals to form a wiring body 3, a first resin layer 4 directly or indirectly supporting the wiring body 3, and a pair of electrodes 5 directly contacting the conductive linear bodies 31. In addition, the first substrate 1 and the wiring sheet 10 are laminated together with a second resin layer 6 having a lower storage modulus than the first resin layer 4 interposed therebetween.

[0190] (Effects of the Second Embodiment)

[0191] According to the present embodiment, the effects (1) to (4) of the first embodiment described above can be exerted.

[0192] [Variations of the Embodiment]

[0193] The present application is not limited to the above-described embodiments, and variations, improvements, and the like within the scope of achieving the object of the present application are included in the present application.

[0194] For example, in the above-described embodiments, the laminate 100 includes the film-shaped first substrate 1, but is not limited thereto. For example, the first substrate 1 can be a substrate shaped into a three-dimensional shape. In such a case, the wiring sheet 10 can be used by being attached to the first substrate 1 as an adherend by the first resin layer 4 or the second resin layer 6.

[0195] In the above-described second embodiment, the first substrate 1 and the wiring sheet 10 are laminated together with the second resin layer 6 interposed therebetween in the cross-sectional view of the laminate 100A, but variations are not limited thereto. For example, two other variations can be given. One variation is an example in which the wiring sheet 10 is turned over from the first embodiment (the electrodes 5 are provided on the second substrate 2 side). In addition, the other variation is an example in which the wiring sheet 10 is turned over from the second embodiment (the electrodes 5 are provided on the second substrate 2).

[0196] Examples

[0197] Hereinafter, the present application will be further described with examples. The present application is not limited by any of these examples.

[0198] In addition, the evaluation of the laminate obtained in the examples is performed as described below.

[0199] [Fracture Evaluation]

[0200] After the laminate was left to stand for 1000 hours at 105°C, it was confirmed by a digital microscope whether or not the base material layer of the laminate was cracked.

[0201] [Measurement of Storage Modulus]

[0202] A test sample in the form of a cylinder having a diameter of 8 mm and a thickness of 1 mm was prepared from the same composition as the composition forming the layer to be measured. The storage modulus of the test sample was measured by a viscoelasticity measuring device (Anton Paar Co., Ltd., device name "MCR300") under conditions where a parallel plate having a diameter of 8 mm was used as a clamp, the test start temperature was -20°C, the test end temperature was 150°C, the temperature increase rate was 3°C / min, the shear strain was 0.05%, and the frequency was 1 Hz.

[0203] [Measurement of Linear Expansion Coefficient]

[0204] A test sample was prepared by cutting the base material into a rectangle having a length of 4.5 mm and a width of 20 mm. The linear expansion coefficient of the test sample was measured by a thermomechanical analysis device (Netzsch Japan Co., Ltd., product name "TMA4000SE") under conditions where the tensile load was 2 g, the temperature range was 23 to 105°C, and the temperature increase rate was 5°C / min.

[0205] [Preparation Example 1]

[0206] To 100 parts by mass of a phenoxy resin (Mitsubishi Chemical Corporation, product name "YX7200B35"), 170 parts by mass of a multifunctional hydrogenated bisphenol A diglycidyl ether epoxy compound (Mitsubishi Chemical Corporation, product name "YX8000"), 0.2 parts by mass of a silane coupling agent (Shin-Etsu Chemical Co., Ltd., product name "KBM-4803"), 2 parts by mass of a cationic polymerization initiator (San-Aid Industrial Co., Ltd., product name "SAN-AID SI-B3"), and 2 parts by mass of a cationic polymerization initiator (San-Aid Industrial Co., Ltd., product name "SAN-AID SI-B7") were added to obtain a curable adhesive.

[0207] [Preparation Example 2]

[0208] (Preparation of (Meth)acrylate Polymer (A))

[0209] An acrylic acid 2-ethylhexyl ester 65 parts by mass, a 4-acryloylmorpholine 5 parts by mass, an isobornyl acrylate 15 parts by mass, and a 2-hydroxyethyl acrylate 15 parts by mass were copolymerized to prepare a (meth)acrylate polymer (A). The molecular weight of the (meth)acrylate polymer (A) was measured, and the result was a weight average molecular weight (Mw) of 500,000. In addition, the glass transition temperature (Tg, unit: °C) of the (meth)acrylate polymer (A) was calculated by FOX formula based on the glass transition temperatures (Tg) of homopolymers of each monomer constituting the (meth)acrylate polymer (A), and the result was -36.5°C.

[0210] (Preparation of the adhesive composition)

[0211] The (meth)acrylate polymer (A) obtained 100 parts by mass (solid content conversion, the same hereinafter), a trimethylolpropane-modified toluene diisocyanate as the crosslinking agent (B) 0.18 parts by mass, an ε-caprolactone-modified tris(2-acryloyloxyethyl) isocyanurate as the energy ray-curable component (C) 7 parts by mass, a mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone mixed at a mass ratio of 1:1 as the photopolymerization initiator (D) 0.7 parts by mass, and 3-glycidoxypropyltrimethoxysilane as the silane coupling agent 0.28 parts by mass were mixed, sufficiently stirred, and diluted with methyl ethyl ketone, whereby a coating solution of the adhesive composition was obtained.

[0212] [Preparation Example 3]

[0213] (Preparation of the adhesive composition)

[0214] The (meth)acrylate polymer (A) obtained in Preparation Example 2 100 parts by mass, a trimethylolpropane-modified toluene diisocyanate as the crosslinking agent (B) 0.15 parts by mass, an ε-caprolactone-modified tris(2-acryloyloxyethyl) isocyanurate as the energy ray-curable component (C) 5 parts by mass, 2,4,6-trimethylbenzoyl diphenyl phosphine oxide as the photopolymerization initiator (D) 0.5 parts by mass, and 3-glycidoxypropyltrimethoxysilane as the silane coupling agent 0.25 parts by mass were mixed, sufficiently stirred, and diluted with methyl ethyl ketone, whereby a coating solution of the adhesive composition was obtained.

[0215] [Preparation Example 4]

[0216] (Preparation of the (meth)acrylate polymer (A))

[0217] An acrylic acid 2-ethylhexyl ester 30 parts by mass, a n-butyl acrylate 25 parts by mass, a 4-acryloylmorpholine 5 parts by mass, an isobornyl acrylate 15 parts by mass, and a 2-hydroxyethyl acrylate 25 parts by mass were copolymerized to prepare a (meth)acrylate polymer (A). The molecular weight of the (meth)acrylate polymer (A) was measured, and the result was that the weight average molecular weight (Mw) was 600,000.

[0218] (Preparation of an adhesive composition)

[0219] The obtained (meth)acrylate polymer (A) 100 parts by mass, a trimethylolpropane-modified toluene diisocyanate 0.2 parts by mass as a crosslinking agent (B), an ε-caprolactone-modified tris(2-acryloyloxyethyl) isocyanurate 8.0 parts by mass as an energy ray-curable component (C), a 2,4,6-trimethylbenzoyldiphenylphosphine oxide 0.8 parts by mass as a photopolymerization initiator (D), and a 3-glycidoxypropyltrimethoxysilane 0.2 parts by mass as a silane coupling agent were mixed, sufficiently stirred, and diluted with methyl ethyl ketone to prepare a coating solution of an adhesive composition.

[0220] [Example 1]

[0221] (Production of a wiring body film)

[0222] An adhesive obtained in Production Example 1 was coated on a release film (Lindberg Corporation, product name "SP-382150") having a thickness of 38 μm so that the thickness was 15 μm, and cut into a rectangular shape of 250 mm x 320 mm to produce an adhesive sheet. As a conductive linear body, a gold-plated tungsten wire (diameter 10 μm, hereinafter also referred to as a wire) was prepared. Next, the obtained adhesive sheet was wound around a drum member having a rubber outer peripheral surface in a manner that the surface of the pressure-sensitive adhesive layer faced outward and was not wrinkled, and both end portions of the adhesive sheet in the circumferential direction were fixed with a double-sided tape. The wire wound around the drum was attached to the surface of the pressure-sensitive adhesive layer of the adhesive sheet near the end portion of the drum member, and then, the wire was fed out while being wound with the drum member, and the drum member was moved stepwise in a direction parallel to the drum axis so that the wire was drawn in a spiral at intervals of 3 mm and was wound around the drum member. Thus, a wiring body was formed in a state that 96 wires were arranged on the surface of the adhesive. Then, the wire was cut, and the wiring body was removed from the drum member. The wiring body was cut into a width of 40 x 82 mm in a manner that 12 wires were taken out, and a wiring body film was produced.

[0223] (Production of a substrate with an electrode)

[0224] A glass having a thickness of 2 mm (linear expansion coefficient 3.3 x 10 -6A silver paste was screen-printed in a manner such that the width was 2 mm and the distance between electrodes was 7.8 mm, and then dried at a temperature of 150°C for 30 minutes to form a belt-shaped electrode having a thickness of 17 μm. Then, the belt-shaped electrode was subjected to electroless plating to produce a substrate with an electrode.

[0225] (Formation of wiring sheet)

[0226] The obtained wiring body film was attached to the obtained substrate with an electrode in a manner such that the electrode was positioned at both ends of the line. Then, the adhesive was cured by heating at a temperature of 120°C, a pressure of 0.5 MPa, and for 30 minutes to form a first resin layer, and a wiring sheet was formed on the first substrate.

[0227] Note that the storage modulus of the first resin layer at 23°C was 2.2 x 10 9 Pa, and the storage modulus of the first resin layer at 105°C was 1.6 x 10 9 Pa.

[0228] (Production of protective sheet)

[0229] The coating solution of the adhesive composition obtained in Preparation Example 2 was coated on a cyclic olefin polymer film (manufactured by Zeon Corporation, product name "ZF16") having a thickness of 100 μm as a second substrate in a manner such that the thickness was 100 μm, and cut into a rectangular shape of 50 mm x 120 mm. Then, two holes having a diameter of 5 mm were formed by digging out circles with a center-to-center distance of 7.8 mm to produce a protective sheet.

[0230] The linear expansion coefficient of the second substrate is shown in Table 1.

[0231] (Production of laminate)

[0232] The protective sheet was attached to the first substrate provided with the wiring sheet in a manner such that the electrode of the wiring sheet coincided with the circle of the protective sheet. Then, a second resin layer was formed by irradiating ultraviolet rays having a wavelength of 365 nm under conditions of an illuminance of 200 mW / cm 2 , a light amount of 1000 mJ / cm 2 , and a light irradiation time of 30 seconds to obtain a laminate.

[0233] The breakage of the obtained laminate was evaluated. In addition, the storage modulus of the second resin layer at 23°C and 105°C is shown in Table 1.

[0234] [Example 2]

[0235] The cyclic olefin polymer film (manufactured by Zeon Corporation, product name "ZF16") of the protective sheet was changed to a polycarbonate film (manufactured by Teijin Corporation, product name "L-100"), and otherwise, the laminate was produced in the same manner as in Example 1.

[0236] [Example 3]

[0237] A coating solution of the adhesive composition obtained in Preparation Example 2 of the protective sheet was changed to a coating solution of the adhesive composition obtained in Preparation Example 3, and otherwise, a laminate was produced in the same manner as in Example 1.

[0238] [Comparative Example 1]

[0239] A coating solution of the adhesive composition obtained in Preparation Example 2 of the protective sheet was changed to a coating solution of the adhesive composition obtained in Preparation Example 4, and otherwise, a laminate was produced in the same manner as in Example 1.

[0240] [Comparative Example 2]

[0241] A coating solution of the adhesive composition obtained in Preparation Example 2 of the protective sheet was changed to a coating solution of the adhesive composition obtained in Preparation Example 4, and a cycloolefin polymer film (manufactured by Zeon Corporation, product name "ZF16") was changed to a polycarbonate film (manufactured by Teijin Limited, product name "L-100"), and otherwise, a laminate was produced in the same manner as in Example 1.

[0242]

[0243] As shown in Table 1, the results of the evaluation of the breakage of the laminates obtained in Examples 1 to 3 were good. It was thus confirmed that a laminate capable of preventing breakage of a substrate can be obtained according to the present application.

Claims

1. A laminate comprising: a first substrate, a second substrate having a higher linear expansion coefficient than the first substrate, and a wiring sheet held between the first substrate and the second substrate, the wiring sheet comprising: a wiring body in which a plurality of electrically conductive linear bodies are arranged at intervals, a first resin layer directly or indirectly supporting the wiring body, and a pair of electrodes in direct contact with the electrically conductive linear bodies, the first substrate or the second substrate being laminated together with the wiring sheet with a second resin layer having a lower storage modulus than the first resin layer interposed therebetween.

2. The laminate according to claim 1, wherein 3. The laminate according to claim 1 or 2, wherein 4. The laminate according to claim 1 or 2, wherein 5. The laminate according to claim 1 or 2, wherein 6. The laminate according to claim 1 or 2, wherein the second substrate is laminated together with the wiring sheet with the second resin layer interposed therebetween. ​ ​ ​ The storage modulus of the second resin layer at 23°C is 1.0 x 10 4 Pa or more and 3.0 x 10 5 Pa or less. ​ The storage modulus of the first resin layer at 23°C is 5.0 x 10 6 Pa or more and 1.0 x 10 10 Pa or less. ​ The linear expansion coefficient of the first substrate is 0.01 x 10 -6 / °C or more and 10 x 10 -6 / °C or more and 10 x 10 ​ The linear expansion coefficient of the second substrate is 50 x 10 -6 / °C or more and 100 x 10 -6 / °C or less. ​ ​

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