Conductive composition, conductive layer, adherend having conductive layer, joined body, and separation method for joined body

Abstract

The present invention provides a conductive composition that can form a conductive layer having high adhesive strength and that, when a joined body is formed in which an electrically separable adhesive sheet and an adherend comprising the conductive layer are affixed, results in sufficient reduction in adhesive strength in an electrically separable adhesive layer of the electrically separable adhesive sheet upon application of voltage thereto. The present invention relates to a conductive composition comprising a resin component, wherein the contact angle of 1-ethylimidazole one second after a droplet thereof lands on a conductive layer formed from the conductive composition is 16-35°.

Description

Conductive Composition, Conductive Layer, Substrate Having Conductive Layer, Bonded Body, and Method for Separating Bonded Body

[0001] The present invention relates to a conductive composition, a conductive layer, a substrate having a conductive layer, a bonded body, and a method for separating a bonded body.

[0002] In electronic component manufacturing processes and the like, there is an increasing demand for rework to improve yield and recycling in which components are disassembled and recovered after use. To meet such demands, in joining members in electronic component manufacturing processes and the like, a double-sided adhesive sheet having a certain adhesive strength and a certain peelability may be used.

[0003] As a double-sided adhesive sheet that realizes the above adhesive strength and peelability, a salt compound such as an ionic liquid composed of a cation and an anion is used as a component for forming an adhesive composition, and a sheet that peels by applying a voltage to an adhesive layer (electrically peelable adhesive sheet) is known (Patent Documents 1 to 3). Patent Documents 1 to 3 disclose a method of separating a bonded body in which a non-conductive substrate, a conductive layer containing a resin component, an electrically peelable adhesive layer, and a substrate having a conductive layer or a conductive substrate are laminated in this order by applying a voltage.

[0004] Japanese Patent Application Laid-Open No. 2019-509370, Japanese Patent No. 4139851, Japanese Patent Application Laid-Open No. 2011-52056

[0005] As a result of investigations by the present inventors, when attempting to peel an electrically peelable adhesive sheet by applying a voltage to a bonded body to which an electrically peelable adhesive sheet is attached to a substrate having a conductive layer containing a resin component, the peel force between the conductive layer and the electrically peelable adhesive layer does not sufficiently decrease, and / or a part of the conductive layer adheres to the electrically peelable adhesive layer of the electrically peelable adhesive sheet, and it has been found that problems such as the electrically peelable adhesive layer (electrically peelable adhesive sheet) being unusable may occur.

[0006] The present invention has been completed in view of the above, and aims to provide a conductive composition that can form a conductive layer with high adhesive strength, and when a bond is formed by adhering an electropenetrating adhesive sheet and an adherend having the conductive layer, the adhesive strength of the electropenetrating adhesive layer on the electropenetrating adhesive sheet is sufficiently reduced by the application of voltage; a conductive layer formed by the conductive composition; an adherend having the conductive layer; a bond having the adherend having the conductive layer; and a method for separating the bond having the adherend having the conductive layer.

[0007] As a result of repeated studies by the present inventors, it was found that the above problem can be solved by setting the contact angle of 1-ethylimidazole to the conductive layer formed by a conductive composition containing a resin component, one second after droplet application, to be between 16° and 35°.

[0008] The means for solving the above problems are as follows: [1] A conductive composition comprising a resin component, wherein the contact angle of 1-ethylimidazole to the conductive layer formed by the conductive composition after 1 second of droplet deposition is 16° or more and 35° or less. [2] The conductive composition according to [1], wherein the surface resistance of the conductive layer is 8000 Ω / □ or less. [3] The conductive composition according to [1], wherein the surface resistance of the conductive layer is 3000 Ω / □ or less. [4] The conductive composition according to [1], wherein the arithmetic mean surface roughness Ra of the conductive layer is 0.65 μm or less. [5] The conductive composition according to [1], wherein the contact angle of water to the conductive layer after 1 second of droplet deposition is 110° or less. [6] The conductive composition according to [1], wherein the glass transition temperature Tg of the resin component after curing is higher than 50°C. [7] The conductive composition according to any one of [1] to [6] for forming a conductive layer to be attached to an electropenetrating adhesive layer containing an ionic substance. [8] A conductive layer formed by a conductive composition according to any one of [1] to [6]. [9] A conductive layer formed by a conductive composition containing a resin component, wherein the contact angle of 1-ethylimidazole to the conductive layer 1 second after droplet placement is 16° or more and 35° or less.

[10] The conductive layer according to [9], wherein the surface resistance of the conductive layer is 8000 Ω / □ or less.

[11] The conductive layer according to [9], wherein the surface resistance of the conductive layer is 3000 Ω / □ or less.

[12] The conductive layer according to [9], wherein the arithmetic mean surface roughness Ra of the conductive layer is 0.65 μm or less.

[13] The conductive layer according to [9], wherein the contact angle of water to the conductive layer 1 second after droplet placement is 110° or less.

[14] The conductive layer according to [9], wherein the glass transition temperature Tg of the resin component after curing is higher than 50°C.

[15] A conductive layer according to any one of [9] to

[14] , which is attached to an electropenetrating adhesive layer containing an ionic substance.

[16] A substrate having a conductive layer formed from a conductive composition according to any one of [1] to [6], or a conductive layer according to any one of [9] to

[14] .

[17] A bond comprising a workpiece having a conductive layer, an adhesive layer, and a conductive substrate laminated in that order, wherein the adhesive layer is attached to the conductive layer side of the workpiece, and the conductive layer is formed of a conductive composition according to any one of [1] to [6], or is a conductive layer according to any one of [9] to

[14] .

[18] The bond according to

[17] , wherein the adhesive layer is an electropenetrating adhesive layer containing an ionic substance.

[19] The bond according to

[18] , wherein the ionic substance is an ionic liquid.

[20] The bond according to

[17] , wherein the adhesive layer is a pressure-sensitive adhesive layer.

[21] A method for separating a bond obtained by attaching an electropenetrating adhesive sheet comprising a conductive substrate and an electropenetrating adhesive layer containing an ionic substance to a workpiece according to

[16] , the method comprising applying a voltage to the electropenetrating adhesive layer to separate the electropenetrating adhesive sheet from the workpiece.

[0009] The conductive composition of the present invention can form a conductive layer with high adhesive strength. By applying a voltage to a joint formed by adhering an object having the conductive layer and an electropenetrating adhesive sheet, the adhesive strength of the electropenetrating adhesive layer of the electropenetrating adhesive sheet is sufficiently reduced, allowing the object and the electropenetrating adhesive sheet to be easily separated.

[0010] Figure 1 is a cross-sectional view showing an example of a substrate having a conductive layer according to an embodiment of the present invention. Figure 2 is a cross-sectional view showing an example of a laminated structure of a bond according to an embodiment of the present invention. Figure 3 is a cross-sectional view showing an example of a laminated structure of a bond according to an embodiment of the present invention. Figure 4 is a cross-sectional view showing an example of a laminated structure of a bond according to an embodiment of the present invention. Figure 5 is a cross-sectional view showing an example of a laminated structure of a bond according to an embodiment of the present invention. Figure 6 is a cross-sectional view showing an overview of the 180° peel test method in the example.

[0011] The embodiments for carrying out the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below. In this specification, "adhesive" is used to mean a tackling agent (also called a "pressure-sensitive adhesive").

[0012] [Conductive Composition] The conductive composition according to the embodiment of the present invention is a conductive composition containing a resin component, wherein the contact angle of 1-ethylimidazole to the conductive layer formed by the conductive composition after 1 second of droplet application is 16° or more and 35° or less.

[0013] The mechanism by which the above problem is solved by setting the contact angle of 1-ethylimidazole to the conductive layer formed by the conductive composition according to the embodiment of the present invention to 16° or more and 35° or less 1 second after droplet application is unclear, but the inventors speculate as follows: In electropenetrating adhesive layers (electropenetrating adhesive sheets) containing ionic substances, it is generally believed that when a voltage is applied, cations of the ionic substance move on the cathode side, causing reduction, and anions of the ionic substance move on the anode side, causing oxidation, which weakens the adhesive strength at the adhesive interface and makes it easier to peel off.

[0014] When attempting to separate a bond between an adherend having a conductive layer containing a resin component and a conductive substrate, which are bonded via an electro-peelable adhesive layer, by applying voltage, if a cathode is attached to the conductive layer, reduced cations of ionic substances that have migrated to the conductive layer may seep into the resin component of the conductive layer. When reduced cations seep into the resin component, electro-penetration occurs at the interface between the conductive material and the resin component in the conductive layer, which is thought to cause cohesive failure of the conductive layer. As a result, it is presumed that the reduction in peeling force due to voltage application will be insufficient, and a portion of the conductive layer may peel off from the adherend and adhere to the electro-peelable adhesive layer.

[0015] The inventors hypothesized that there is a correlation between the contact angle of 1-ethylimidazole immediately after dropping it onto a conductive layer, the ease with which the cation reduction product penetrates the resin component, and the ease with which the cation reduction product spreads at the adhesive interface. They believed that a suitable conductive composition could be selected using the contact angle of 1-ethylimidazole immediately after dropping it onto a conductive layer. Therefore, the contact angle of 1-ethylimidazole 1 second after dropping it onto the conductive layer was used for evaluation. 1 second after dropping, the contour shape of the dropped droplet is relatively stable, and it is the initial stage of penetration into the resin component, making it easy to stably evaluate the ease of penetration into the resin component.

[0016] The ease with which cation reductions penetrate into resin components is thought to be mainly influenced by the strength of the interaction between the cation reduction and the resin component, and the size of the cation reduction. The strength of the interaction between the cation reduction and the resin component is thought to be influenced by the presence or absence of a lone pair of electrons in the cation reduction. Examples of cation reductions of ionic substances include reduced imidazolium, pyrrolidinium, pyridinium, piperidinium, ammonium, and phosphonium cations. The cation reductions of the above ionic substances have a lone pair of electrons. Since 1-ethylimidazole has a lone pair of electrons, it was considered that it could be used to measure the contact angle to evaluate the ease with which the above ionic cation reductions penetrate.

[0017] Furthermore, the smaller the size of the cation reduction product, the easier it is for it to penetrate into the resin component. Among the similar substances to the cation reduction product, using 1-ethylimidazole, which has a relatively small molecular weight, is preferable in that it allows for the selection of suitable resin components in which the penetration of the cation reduction product is suppressed. Based on the above, we believe that 1-ethylimidazole can be used to measure the contact angle in evaluating the ease with which the cation reduction product of the above-mentioned ionic substance penetrates into the resin component.

[0018] In the conductive layer formed by the conductive composition in the embodiment of the present invention, the contact angle of 1-ethylimidazole, a substance similar to the above-mentioned cation reduction, one second after droplet application is within a predetermined range. Therefore, the penetration of the cation reduction into the resin component is suppressed, and the cation reduction spreads easily at the adhesive interface. As a result, it is considered that the peeling force is sufficiently reduced by the application of voltage at the interface between the conductive layer and the electropenetrating adhesive layer, and that a portion of the conductive layer is prevented from peeling off from the adherend.

[0019] The contact angle of 1-ethylimidazole to the conductive layer one second after droplet application is 16° or more and 35° or less, which is necessary from the viewpoint of improving the rate of reduction of peeling force due to voltage application, as it facilitates the wetting and spreading of the cation reduction at the adhesive interface. The contact angle of 1-ethylimidazole one second after droplet application is preferably 34° or less, more preferably 32° or less, even more preferably 30° or less, even more preferably 28° or less, and particularly preferably 25° or less. Furthermore, the contact angle of 1-ethylimidazole to the conductive layer one second after droplet application is preferably 17° or more, more preferably 18° or more, even more preferably 20° or more, and even more preferably 22° or more, from the viewpoint of suppressing the penetration of cation reduction into the resin component.

[0020] The contact angle of 1-ethylimidazole to the conductive layer 30 seconds after application is preferably 34° or less, more preferably 32° or less, even more preferably 30° or less, even more preferably 28° or less, and particularly preferably 25° or less. Furthermore, the contact angle of 1-ethylimidazole to the conductive layer 30 seconds after application is preferably 17° or more, and more preferably 18° or more. The contact angle of 1-ethylimidazole to the conductive layer 30 seconds after application can be, for example, 19° or more, or 20° or more.

[0021] The contact angle of water on the conductive layer one second after droplet placement is preferably 110° or less, more preferably 100° or less, even more preferably 90° or less, even more preferably 89° or less, and even more preferably 88° or less, from the viewpoint of ensuring good wettability of the conductive layer to the adhesive to which the adhesive is applied. The contact angle of water on the conductive layer one second after droplet placement may also be, for example, 87° or less, 86° or less, 85° or less, or 80° or less. Furthermore, the contact angle of water on the conductive layer one second after droplet placement is preferably 50° or more, more preferably 60° or more, and even more preferably 70° or more. The contact angle of water on the conductive layer one second after droplet placement can be measured in the same way as the contact angle of 1-ethylimidazole on the conductive layer one second after droplet placement.

[0022] The contact angle of water droplets on the conductive layer one second after application can be adjusted by setting the type and content of the resin components and conductive materials contained in the conductive layer to the preferred range described later. More specifically, the contact angle of water droplets on the conductive layer one second after application tends to decrease by, for example, increasing the glass transition temperature (Tg) of the resin components contained in the conductive layer after curing, and / or increasing the polarity, and / or increasing the crosslinking density, and / or selecting a conductive material with a small average diameter of spherical conductive material particles or a conductive material with a short short axis length of anisotropic conductive material.

[0023] Furthermore, the conductive composition according to the embodiment of the present invention is a conductive composition containing a resin component, and the contact angle change rate of 1-ethylimidazole to the conductive layer formed by the conductive composition, as calculated by the following formula, may be 55% or less. Contact angle change rate (%) = [(Contact angle 1 second after droplet application) - (Contact angle 30 seconds after droplet application)] × 100 / (Contact angle 1 second after droplet application)

[0024] Here, the contact angle 1 second after droplet placement and the contact angle 30 seconds after droplet placement refer to the contact angle 1 second and 30 seconds after 1-ethylimidazole is dropped onto the conductive layer, respectively.

[0025] The rate of change of the contact angle of 1-ethylimidazole with respect to the conductive layer may be 55% or less, preferably 53% or less, more preferably 50% or less, even more preferably 40% or less, even more preferably 30% or less, particularly preferably 25% or less, even more particularly preferably 23% or less, and even more particularly preferably 20% or less. By limiting the rate of change of the contact angle of 1-ethylimidazole with respect to the conductive layer to a predetermined level or less, the penetration of cation reductions into the resin component tends to decrease. Furthermore, there is no particular limit to the lower limit of the rate of change of the contact angle of 1-ethylimidazole with respect to the conductive layer, but for example, it may be 0% or more, 1% or more, or 2% or more.

[0026] The contact angle of 1-ethylimidazole on the conductive layer one second after droplet placement, and the contact angle 30 seconds after droplet placement, can be measured using the droplet method (also known as the static contact angle method or static droplet method) under conditions of 25°C ± 5°C and 50 ± 5% relative humidity, for example, using a contact angle meter (product name "DMo-501", control box "DMC-2", control and analysis software "FAMAS (version 5.0.30)" manufactured by Kyowa Interface Science Co., Ltd.). The control and analysis software "FAMAS (version 5.0.30)" can automatically recognize the moment of droplet placement and acquire an image of the droplet at the moment a specified time has elapsed since placement. The amount of 1-ethylimidazole dropped is 2 μL, and the contact angle (°) is calculated from the image taken one second after placement using the θ / 2 method. For example, the average value of the calculated values ​​can be used when the procedure is performed in N3.

[0027] The rate of change in the contact angle of 1-ethylimidazole with respect to the conductive layer can be adjusted by setting the type and content of the resin component and conductive material contained in the conductive layer to the preferred range described below. More specifically, it tends to decrease by increasing the glass transition temperature (Tg) after curing of the resin component contained in the conductive layer, and / or lowering its polarity, and / or increasing the crosslinking density, and / or selecting a conductive material with a small average diameter of spherical conductive material particles or a conductive material with a short short axis diameter.

[0028] In the embodiments of the present invention, the surface resistance of the conductive layer formed by the conductive composition is preferably 0.01 Ω / □ or higher from the viewpoint of suppressing the risk of electrostatic discharge and electric shock. Furthermore, the surface resistance of the conductive layer is preferably 8000 Ω / □ or lower, more preferably 6000 Ω / □ or lower, even more preferably 3000 Ω / □ or lower, even more preferably 1500 Ω / □ or lower, even more preferably 1000 Ω / □ or lower, particularly preferably 500 Ω / □ or lower, particularly particularly preferably 300 Ω / □ or lower, even more particularly preferably 100 Ω / □ or lower, and most preferably 80 Ω / □ or lower.

[0029] The surface resistance of the conductive layer can be adjusted by setting the type and content of the resin component and conductive material contained in the conductive layer to the preferred range described later. More specifically, the surface resistance of the conductive layer tends to decrease by, for example, selecting a conductive material that disperses well with respect to the resin component contained in the conductive layer, and / or increasing the amount of conductive material. The surface resistance of the conductive layer on the adherend can be measured, for example, using a resistivity meter (Loresta GP MCP-T160, manufactured by Nitto Seiko Analytech Co., Ltd.) in an environment of 25°C ± 5°C and 50 ± 5% relative humidity, in accordance with JIS K 7194:1994, using the four-terminal method with an ASP probe, an applied voltage of 10V, and an applied time of 10 seconds.

[0030] The arithmetic mean surface roughness (Ra) of the conductive layer formed by the conductive composition in the embodiments of the present invention is preferably 0.65 μm or less, more preferably 0.50 μm or less, even more preferably 0.40 μm or less, even more preferably 0.30 μm or less, even more preferably 0.25 μm or less, and particularly preferably 0.20 μm or less, from the viewpoint of improving the adhesion of the adhesive layer attached to the surface of the conductive layer. Furthermore, from the viewpoint of ease of manufacturing the conductive layer, it may be 0.01 μm or more, or 0.05 μm or more.

[0031] The arithmetic mean surface roughness (Ra) of a conductive layer tends to decrease, for example, by selecting a conductive material with a small average diameter of spherical conductive particles or a conductive material with a short minor axis diameter, and / or by selecting a conductive material that disperses well with respect to the resin components contained in the conductive layer, and / or by reducing the amount of conductive material.

[0032] The arithmetic mean surface roughness (Ra) of a conductive layer can be measured, for example, using a white light interferometer (Zygo, product name "Newview9000"), by generating interference fringes using a single white LED illumination and scanning in the Z direction (thickness method).

[0033] The following describes each component included in the conductive composition.

[0034] <Resin component> The conductive composition according to the embodiment of the present invention includes a resin component. The resin component is not particularly limited as long as the contact angle of 1-ethylimidazole in the formed conductive layer is within the range described above, but examples include polyimide resins, acrylic resins, polyester resins, epoxy resins, vinyl chloride resins, and polyvinyl butyral. Among these, it is preferable to include polyimide resins, epoxy resins, and polyvinyl butyral.

[0035] The polyimide resin may be an aliphatic polyimide or an aromatic polyimide, and it is preferable that it contains an aromatic ring, with aromatic polyimides being preferred.

[0036] The epoxy resin may be a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a phenol novolac type epoxy resin. Furthermore, it is preferable to include a polyfunctional epoxy resin with three or more functions. Including a polyfunctional epoxy resin with three or more functions tends to suppress the penetration of cation reduction products and facilitate wetting, and the contact angle of 1-ethylimidazole 1 second after droplet placement tends to fall within a suitable range. Therefore, the peeling force tends to decrease when a voltage is applied. From the viewpoint of suppressing the penetration of cation reduction products into the resin component and / or improving the rate of peeling force reduction due to voltage application, the content of the polyfunctional epoxy resin with three or more functions is preferably 30% by mass or more of the total epoxy resin, more preferably 40% by mass or more, and particularly preferably 50% by mass or more. Also, if the epoxy equivalent of the epoxy resin is 10,000 g / eq. or less, the contact angle of 1-ethylimidazole 1 second after droplet placement tends to fall within a suitable range, and 5,000 g / eq. It is more preferable to include the following, even more preferable to include the following at 1000 g / eq. or less, and particularly preferable to include the following at 500 g / eq. or less. The epoxy equivalent of the epoxy resin can be, for example, 400 g / eq. or less, 300 g / eq. or less, 200 g / eq. or less, or 150 g / eq. or less. Furthermore, from the viewpoint of improving the adhesion between the conductive layer and the substrate, it is preferable to include the following at 30 g / eq. or more, and more preferable to include the following at 30 g / eq. or more.

[0037] These resin components can be used individually or in combination of two or more types.

[0038] The resin component preferably has a glass transition temperature (Tg) higher than 50°C after curing. A glass transition temperature (Tg) higher than 50°C is preferable because it tends to reduce the peeling force when a voltage is applied, more preferably 60°C or higher, even more preferably 65°C or higher, and particularly preferably 70°C or higher. Furthermore, the upper limit of the glass transition temperature (Tg) is preferably 400°C or lower because it provides excellent adhesion between the adherend and the conductive layer, more preferably 250°C or lower, even more preferably 200°C or lower, particularly preferably 150°C or lower, even more particularly preferably 100°C or lower, and most preferably 80°C or lower.

[0039] When two or more resin components are used, the average value of the glass transition temperature (Tg) is preferably higher than 50°C, more preferably 60°C or higher, even more preferably 65°C or higher, and particularly preferably 70°C or higher. Furthermore, the average value of the glass transition temperature (Tg) is preferably 400°C or lower, more preferably 250°C or lower, even more preferably 200°C or lower, particularly preferably 150°C or lower, even more preferably 100°C or lower, and most preferably 80°C or lower.

[0040] In embodiments of the present invention, the resin component preferably includes at least one selected from resins having a glass transition temperature (Tg) higher than 50°C and epoxy resins. The glass transition temperature (Tg) of the resin component after curing tends to increase, for example, by selecting a resin with a high glass transition temperature (Tg) after curing, and / or by selecting monomers with a high glass transition temperature (Tg) of homopolymers or increasing the amount added, and / or by selecting a resin having thermal crosslinking properties, and / or by adding a crosslinking agent or increasing the amount added, and / or by increasing the crosslinking density. Methods for adjusting the crosslinking density include, for example, increasing the amount of functional groups that can act as crosslinking base points in the resin, and increasing the functional group density, as well as selecting a type of crosslinking agent, increasing the amount of functional groups, increasing the functional group density, and increasing the amount blended. When an epoxy resin is included, for example, the glass transition temperature (Tg) tends to increase by selecting a polyfunctional epoxy resin with three or more functions or increasing the amount added, and by adding a crosslinking agent or increasing the amount added. When polyimide resin is included, adjusting the overall structure of the resin so that there is a higher proportion of polyamic acid skeletons tends to increase the glass transition temperature (Tg).

[0041] The glass transition temperature (Tg) of the resin component after curing can be calculated in the same way as the Tg of the polymer in the adhesive composition described later. More specifically, approximately 1-2 mg of the cured resin component is weighed into an aluminum open cell, and the reversing heat flow (specific heat component) behavior of the resin component is obtained using a temperature-modulated DSC (product name "Q-2000", manufactured by T.A. Instruments Corporation) at a heating rate of 10°C / min under a nitrogen atmosphere of 50 ml / min. Referring to JIS K 7121, the temperature at the point where a line equidistant in the vertical axis direction from the line extending from the low-temperature baseline and the high-temperature baseline of the obtained reversing heat flow intersects with the curve of the step-like change portion of the glass transition is defined as the glass transition temperature (Tg) of the resin component after curing. If a catalog value is available, the catalog value is used.

[0042] The resin component may be obtained by conventional synthesis methods, or a commercially available product may be used.

[0043] Examples of synthetic polyimide resins include those produced by compounding polyamic acid and epoxy resin and then reacting them with heat. Polyamic acid may be used alone or in combination with other resins.

[0044] Commercially available resins that can be incorporated into the resin component include Imitron #300IX-5 (manufactured by Nakata Coating Co., Ltd., Tg=72℃), Imitron #300IX-3 (manufactured by Nakata Coating Co., Ltd., Tg=152℃), IRP-1405BL-117 (manufactured by Sanwa Technique Co., Ltd., Tg=350℃), etc.; Dianal BR-50 (manufactured by Mitsubishi Chemical Corporation, Tg=108℃), Dianal BR-83 (manufactured by Mitsubishi Chemical Corporation, Tg=105°C), Dianal BR-73 (manufactured by Mitsubishi Chemical Corporation, Tg=97°C), Acrydic AU-7007 (manufactured by DIC Corporation, Tg=100°C), etc.; TP-220 (manufactured by Mitsubishi Chemical Corporation, Tg=67°C), Byron 290 (manufactured by Toyobo MC Corporation, Tg=72°C), Byron 296 (manufactured by Toyobo MC Corporation, Tg=72°C) Tg=68°C), Byron 280 (manufactured by Toyobo MC Co., Ltd.), Byron 200 (manufactured by Toyobo MC Co., Ltd., Tg=67°C), Byron 270 (manufactured by Toyobo MC Co., Ltd., Tg=67°C), Byron 237 (manufactured by Toyobo MC Co., Ltd., Tg=70°C), etc.; JER-828 (manufactured by Mitsubishi Chemical Corporation), JER-1256B40 (manufactured by Mitsubishi Chemical Corporation), JER-630 (Mitsubishi Examples include: chemicals (manufactured by Chemical Co., Ltd.), Solvine A (manufactured by Nisshin Chemical Industry Co., Ltd., Tg = 87°C), S-Rec KS-1 (manufactured by Sekisui Chemical Co., Ltd., Tg = 107°C), S-Rec KS-10 (manufactured by Sekisui Chemical Co., Ltd., Tg = 105°C), S-Rec KS-6Z (manufactured by Sekisui Chemical Co., Ltd., Tg = 113°C), S-Rec BX-1 (manufactured by Sekisui Chemical Co., Ltd., Tg = 95°C), etc.

[0045] The content of the resin component in the conductive composition according to the embodiment of the present invention is preferably 1% by mass or more and 99.9% by mass or less, based on the total amount of the conductive composition (100% by mass), with an upper limit of 95% by mass, even more preferably 90% by mass, and a lower limit of 5% by mass, even more preferably 30% by mass.

[0046] <Conductive Material> The conductive composition according to the embodiment of the present invention includes a conductive material. Examples of the conductive material include conductive fillers and conductive polymer compounds, and it is preferable to use a conductive filler.

[0047] The shape of the conductive filler is not limited to a specific shape and can be, for example, spherical, flake-shaped, dendritic, or fibrous. Examples of conductive fillers include metal fillers, metal-coated resins or glass fillers, carbon nanotubes, graphite, and carbon black. Examples of graphite shapes include, for example, scaly, needle-shaped, fibrous, spherical, flake-shaped, aggregated, and porous. Examples of metal fillers include copper powder, silver powder, nickel powder, silver-coated copper powder, gold-coated copper powder, silver-coated nickel powder, gold-coated nickel powder, and silver nanowires. Among these, carbon-based materials are preferred, and carbon nanotubes or carbon black are more preferred.

[0048] The content of the conductive material is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, per 100 parts by mass of the resin component. The content of the conductive material is preferably 1,500 parts by mass or less, more preferably 1,000 parts by mass or less, and even more preferably 500 parts by mass or less, per 100 parts by mass of the resin component. The content of the conductive material may be, for example, 300 parts by mass or less, 200 parts by mass or less, or 100 parts by mass or less, per 100 parts by mass of the resin component. When the conductive composition according to the embodiment of the present invention contains a curing agent as described later, it is preferable that the content of the conductive material is within the above range relative to 100 parts by mass of the total amount of the resin component and curing agent.

[0049] <Other Components> The conductive composition according to the embodiment of the present invention may further contain a curing agent. As the curing agent, commonly used curing agents such as isocyanate-based curing agents, epoxy-based curing agents, amine-based curing agents, imidazole-based curing agents, polymercaptan-based curing agents, metal-based curing agents, or melamine-based curing agents can be used.

[0050] The conductive composition according to the embodiment of the present invention may also contain various additives such as fillers, plasticizers, antioxidants, antioxidants, pigments (dyes), flame retardants, solvents, water, surfactants (leveling agents), curing accelerators, rust inhibitors, corrosion inhibitors, and antistatic agents. Specifically, examples include fillers, plasticizers, antioxidants, antioxidants, pigments, rust inhibitors, corrosion inhibitors, etc., which may be included in the adhesive composition described later. The total content of these components is not particularly limited as long as the effects of the present invention are achieved, but is preferably 0.01 parts by mass or more and 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the resin component.

[0051] <Method for Manufacturing Conductive Composition> The method for manufacturing a conductive composition according to the embodiment of the present invention is not particularly limited, but it can be manufactured by appropriately stirring and mixing a resin component, a conductive material, and other components such as a solvent that may be added as needed.

[0052] One preferred embodiment of the present invention is a conductive composition for forming a conductive layer that is attached to an electropenetrating adhesive layer containing an ionic substance. A coating layer, as described later, may be provided between the electropenetrating adhesive layer and the other conductive layer. The descriptions of the electropenetrating adhesive layer and the coating layer in the bonded structure described later can be directly applied.

[0053] [Conductive Layer and Adhesion] The conductive layer according to the embodiment of the present invention is formed from the conductive composition described above. The conductive layer according to the embodiment of the present invention is a conductive layer formed from a conductive composition containing a resin component, wherein the contact angle of 1-ethylimidazole to the conductive layer 1 second after droplet placement is 16° or more and 35° or less. The adherend according to the embodiment of the present invention has a conductive layer formed from the conductive composition described above. Preferably, the adherend according to the embodiment of the present invention has a substrate and a conductive layer formed from the conductive composition described above. Figure 1 is a cross-sectional view showing an example of an adherend 3 according to the embodiment of the present invention, in which a conductive layer 1 is laminated on a substrate 2. The contact angle of 1-ethylimidazole to the conductive layer according to the embodiment of the present invention 16° or more and 35° or less is necessary from the viewpoint of improving the rate of reduction of peeling force due to voltage application, as it allows the cation reduction product to easily wet and spread at the adhesive interface. Preferably, the contact angle of 1-ethylimidazole 1 second after droplet placement is 34° or less, more preferably 32° or less, even more preferably 30° or less, even more preferably 28° or less, and particularly preferably 25° or less. Furthermore, the contact angle of 1-ethylimidazole to the conductive layer 1 second after droplet placement is preferably 17° or higher, more preferably 18° or higher, even more preferably 20° or higher, and even more preferably 22° or higher, from the viewpoint of suppressing the penetration of cation reductions into the resin component.

[0054] <Substrate> The substrate 2 of the adherend according to the embodiment of the present invention is not particularly limited, but examples include paper-based substrates such as paper, fiber-based substrates such as cloth and nonwoven fabric, plastic-based substrates such as films, sheets, and housings made of various plastics (polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, acrylic resins such as polymethyl methacrylate, and polyimide resins), glass substrates, metal substrates, and laminates thereof. The substrate may have a single layer or a multi-layer form. The substrate may be subjected to various treatments as needed, such as rust prevention treatment, back treatment, antistatic treatment, and primer treatment.

[0055] <Conductive Layer> The conductive layer 1 according to the embodiment of the present invention is formed from the conductive composition described above. The thickness of the conductive layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, even more preferably 0.1 μm or more, even more preferably 1 μm or more, even more preferably 5 μm or more, and particularly preferably 10 μm or more. The thickness of the conductive layer may be, for example, 15 μm or more, or 20 μm or more. The effects of the present invention are more easily obtained by making the thickness of the conductive layer 1 μm or more. Furthermore, the upper limit of the thickness of the conductive layer is preferably 1000 μm or less, more preferably 500 μm or less, even more preferably 200 μm or less, even more preferably 150 μm or less, even more preferably 100 μm or less, and particularly preferably 50 μm or less. The thickness of the conductive layer may be, for example, 40 μm or less, 30 μm or less, or 20 μm or less. Making the thickness of the conductive layer 1000 μm or less is preferable because it makes film formation easier from the viewpoint of coating properties.

[0056] (Surface resistance of the conductive layer) The surface resistance of the conductive layer according to the embodiment of the present invention is preferably 0.01 Ω / □ or more from the viewpoint of suppressing the risk of electrostatic discharge and electric shock. Furthermore, the surface resistance of the conductive layer is preferably 8000 Ω / □ or less, more preferably 6000 Ω / □ or less, even more preferably 3000 Ω / □ or less, even more preferably 1500 Ω / □ or less, even more preferably 1000 Ω / □ or less, particularly preferably 500 Ω / □ or less, particularly particularly preferably 300 Ω / □ or less, even more particularly preferably 100 Ω / □ or less, and most preferably 80 Ω / □ or less. The surface resistance of the conductive layer on the adherend can be measured by the method and conditions described above.

[0057] <Method for Manufacturing the Conductive Layer and the Adheren> The method for manufacturing the adherend according to the embodiment of the present invention is not particularly limited, but for example, a conductive layer can be formed and the adherend manufactured by applying a conductive composition to the surface of a substrate, drying it, and then curing it by irradiating it with heat, ultraviolet light, electron beam, etc., as necessary. As a method for applying the conductive composition, known techniques such as spray coating, curtain coating, flow coating, dispenser coating, gravure coating, reverse roll coating, roll coating, dip coating, and comma coating can be used.

[0058] [Jointed Body] In an embodiment of the present invention, the jointed body is formed by laminating an adherend having a conductive layer, an adhesive layer, and a conductive substrate in that order, wherein the adhesive layer is attached to the conductive layer side of the adherend having the conductive layer, and the conductive layer is formed of the conductive composition described above.

[0059] The above description can be applied directly to the conductive layer, the adherend having the conductive layer, and the conductive composition.

[0060] <Adhesive Layer> Examples of adhesive layers in a joint according to an embodiment of the present invention include a pressure-sensitive adhesive layer formed by a pressure-sensitive adhesive, an adhesive layer formed by a heat-curing or light-curing adhesive, and an adhesive layer formed by an adhesive composition. The adhesive layer may be a pressure-sensitive adhesive layer, and it is preferable that it be an adhesive layer formed by an adhesive composition.

[0061] The adhesive layer is preferably an electro-peelable adhesive layer that peels off when a voltage is applied, and more preferably an electro-peelable adhesive layer containing an ionic substance. In particular, it is preferable that the ionic substance is an ionic liquid. That is, it is especially preferable that the adhesive layer is an electro-peelable adhesive layer containing an ionic liquid. The adhesive compositions for forming the electro-peelable adhesive layer will be described below.

[0062] <<Components of the Adhesive Composition>> (Polymer) The adhesive composition according to the embodiment of the present invention contains a polymer. In this embodiment, the polymer is not particularly limited as long as it is a general organic polymer compound, for example, a monomer polymer or partial polymer. The monomer may be a single monomer or a mixture of two or more monomers. A partial polymer means a polymer in which at least a part of the monomer or monomer mixture is partially polymerized.

[0063] The polymers according to the embodiments of the present invention are not particularly limited as long as they are commonly used as adhesives and possess adhesive properties, but examples include acrylic polymers, rubber polymers, vinyl alkyl ether polymers, silicone polymers, polyester polymers, polyamide polymers, urethane polymers, fluoropolymers, and epoxy polymers. The polymers can be used alone or in combination of two or more types.

[0064] In order to increase the dielectric constant of components other than ionic substances in the resulting electropenetrating adhesive layer and improve electropenetration, it is preferable that the polymer has a high dielectric constant. From this viewpoint, it is particularly preferable that the polymer in the embodiment of the present invention includes at least one selected from the group consisting of polyester polymers and acrylic polymers having carboxyl groups and / or hydroxyl groups. Since polyester polymers have easily polarizable hydroxyl groups at their ends, and since acrylic polymers having carboxyl groups and / or hydroxyl groups have easily polarizable carboxyl groups and / or hydroxyl groups, using these polymers makes it possible to obtain a polymer with a relatively high dielectric constant. The total content of polyester polymers and acrylic polymers having carboxyl groups and / or hydroxyl groups in the polymer in the embodiment of the present invention is preferably 60% by mass or more, and more preferably 80% by mass or more. Furthermore, in order to increase cost, productivity, and initial adhesive strength, it is preferable that the polymer in the embodiment of the present invention is an acrylic polymer. That is, it is preferable that the adhesive composition in the embodiment of the present invention is an acrylic adhesive composition containing an acrylic polymer as the polymer.

[0065] The acrylic polymer preferably contains monomer units derived from alkyl (meth)acrylate esters having an alkyl group with 1 to 14 carbon atoms (formula (1) below). Such monomer units are suitable for obtaining high initial adhesion. Furthermore, to increase the dielectric constant of components other than ionic substances in the electropenetrating adhesive layer and improve electropenetration, the alkyl group R in formula (1) below is used. ｂ The number of carbon atoms is preferably small, particularly preferably 8 or less, and more preferably 4 or less. ２ = C(R ａ ) COOR ｂ (1) [R in equation (1) ａ R is a hydrogen atom or a methyl group, ｂ [This is an alkyl group having 1 to 14 carbon atoms, which may have substituents.]

[0066] Examples of alkyl (meth)acrylate esters having an alkyl group with 1 to 14 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, 1,3-dimethylbutyl acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, and 2-ethylbutyl (meth)acrylate. Examples include heptyl(meth)acrylate, n-octyl(meth)acrylate, isooctyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, n-nonyl(meth)acrylate, isononyl(meth)acrylate, n-decyl(meth)acrylate, isodecyl(meth)acrylate, n-dodecyl(meth)acrylate, n-tridecyl(meth)acrylate, n-tetradecyl(meth)acrylate, and 2-methoxyethyl acrylate. Among these, n-butyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, and 2-methoxyethyl acrylate are preferred. Alkyl (meth)acrylate esters having an alkyl group with 1 to 14 carbon atoms can be used alone or in combination of two or more.

[0067] The proportion of alkyl (meth)acrylate ester having an alkyl group with 1 to 14 carbon atoms relative to the total monomer components (100% by mass) constituting the acrylic polymer is not particularly limited, but is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 85% by mass or more. When the proportion of alkyl (meth)acrylate ester having an alkyl group with 1 to 14 carbon atoms is 70% by mass or more, it becomes easier to obtain a large initial adhesive strength.

[0068] As an acrylic polymer, it is preferable to include monomer units derived from alkyl (meth)acrylate esters having alkyl groups with 1 to 14 carbon atoms, as well as monomer units derived from polar group-containing monomers copolymerizable thereto, for the purpose of modifying cohesive strength, heat resistance, crosslinkability, etc. The monomer units can provide crosslinking sites and are suitable for obtaining high initial adhesion. Furthermore, from the viewpoint of increasing the dielectric constant of components other than ionic substances in the electropenetrating adhesive layer and improving electropenetration, it is also preferable to include monomer units derived from polar group-containing monomers.

[0069] Examples of polar group-containing monomers include carboxyl group-containing monomers, hydroxyl group-containing monomers, cyano group-containing monomers, vinyl group-containing monomers, aromatic vinyl monomers, amide group-containing monomers, imide group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, vinyl ether monomers, N-acryloylmorpholine, sulfo group-containing monomers, phosphate group-containing monomers, and acid anhydride group-containing monomers. Among these, carboxyl group-containing monomers, hydroxyl group-containing monomers, and amide group-containing monomers are preferred due to their excellent cohesiveness, and carboxyl group-containing monomers are particularly preferred. Carboxyl group-containing monomers are especially suitable for obtaining high initial adhesion. Polar group-containing monomers can be used alone or in combination of two or more types.

[0070] Examples of carboxyl group-containing monomers include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. Acrylic acid is particularly preferred. Carboxyl group-containing monomers can be used alone or in combination of two or more.

[0071] Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, N-methylol (meth)acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether. In particular, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred. Hydroxyl group-containing monomers can be used alone or in combination of two or more.

[0072] Examples of amide group-containing monomers include acrylamide, methacrylamide, N-vinylpyrrolidone, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N,N'-methylenebisacrylamide, N,N-dimethylaminopropylacrylamide, N,N-dimethylaminopropylmethacrylamide, and diacetoneacrylamide. Amide group-containing monomers can be used alone or in combination of two or more.

[0073] Examples of cyano group-containing monomers include acrylonitrile and methacrylonitrile.

[0074] Examples of vinyl group-containing monomers include vinyl acetate, vinyl propionate, and vinyl esters such as vinyl laurate, with vinyl acetate being particularly preferred.

[0075] Examples of aromatic vinyl monomers include styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene, and other substituted styrenes.

[0076] Examples of imide group-containing monomers include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconimide.

[0077] Examples of amino group-containing monomers include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and N,N-dimethylaminopropyl (meth)acrylate.

[0078] Examples of epoxy group-containing monomers include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, and allyl glycidyl ether.

[0079] Examples of vinyl ether monomers include methyl vinyl ether, ethyl vinyl ether, and isobutyl vinyl ether.

[0080] The proportion of polar group-containing monomers to the total monomer components (100% by mass) constituting the acrylic polymer is preferably 0.1% by mass or more and 35% by mass or less. The upper limit of the proportion of polar group-containing monomers is more preferably 25% by mass, even more preferably 20% by mass, the lower limit is more preferably 0.5% by mass, even more preferably 1% by mass, and particularly preferably 2% by mass. When the proportion of polar group-containing monomers is 0.1% by mass or more, cohesive force is easily obtained, so adhesive residue is less likely to occur on the surface of the adherend after peeling off the electrorelease adhesive layer, and electrorelease properties are improved. Furthermore, when the proportion of polar group-containing monomers is 35% by mass or less, it becomes easier to prevent the electrorelease adhesive layer from adhering excessively to the adherend and causing excessive peeling. In particular, when it is 2% by mass or more and 20% by mass or less, it becomes easier to achieve both peelability to the adherend and adhesion between the electrorelease adhesive layer and other layers.

[0081] Furthermore, the monomer components constituting the acrylic polymer may include polyfunctional monomers in order to introduce a cross-linked structure into the acrylic polymer and facilitate obtaining the necessary cohesive force.

[0082] Examples of polyfunctional monomers include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, divinylbenzene, and N,N'-methylenebisacrylamide. Polyfunctional monomers can be used individually or in combination of two or more.

[0083] The content of polyfunctional monomers relative to the total monomer components (100% by mass) constituting the acrylic polymer is preferably 0.1% by mass or more and 15% by mass or less. The upper limit of the polyfunctional monomer content is more preferably 10% by mass, and the lower limit is more preferably 3% by mass. A polyfunctional monomer content of 0.1% by mass or more is preferable because it tends to improve the flexibility and adhesion of the electro-peelable adhesive layer. A polyfunctional monomer content of 15% by mass or less makes it easier to obtain appropriate adhesion without the cohesive force becoming too high.

[0084] Polyester polymers are typically polymers having a structure in which polycarboxylic acids such as dicarboxylic acids or their derivatives (hereinafter also referred to as "polycarboxylic acid monomers") and polyhydric alcohols such as diols or their derivatives (hereinafter referred to as "polyhydric alcohol monomers") are condensed together.

[0085] The polycarboxylic acid monomers are not particularly limited, but examples include adipic acid, azelaic acid, dimer acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, dodecenyl succinic anhydride, fumaric acid, succinic acid, dodecanediic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, maleic acid, maleic anhydride, itaconic acid, citraconic acid, isophthalic acid, terephthalic acid, orthophthalic acid, benzylmalonic acid, 2,2'-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-dicarboxydiphenyl ether, naphthalenedicarboxylic acid, and derivatives thereof. The polycarboxylic acid monomers can be used alone or in combination of two or more.

[0086] The polyhydric alcohol monomer is not particularly limited, but examples include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,5-pentanediol, 2-ethyl-2-butylpropanediol, 1,9-nonanediol, 2-methyloctanediol, 1,10-decanediol, and derivatives thereof. The polyhydric alcohol monomer can be used alone or in combination of two or more.

[0087] Furthermore, the polymer according to the embodiment of the present invention may also contain an ionic polymer. An ionic polymer is a polymer having an ionic functional group. By including an ionic polymer in the polymer, the dielectric constant of the polymer increases, and the electrolytic properties are improved. When the polymer contains an ionic polymer, the content of the ionic polymer is preferably 0.05 parts by mass or more and 2 parts by mass or less per 100 parts by mass of the polymer.

[0088] In this embodiment, the polymer can be obtained by (co)polymerizing monomer components. The polymerization method is not particularly limited, but examples include solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and photopolymerization (active energy ray polymerization). Solution polymerization is particularly preferred from the viewpoint of cost and productivity. When copolymerized, the polymer may be a random copolymer, block copolymer, alternating copolymer, graft copolymer, etc.

[0089] Solution polymerization methods are not particularly limited, but include methods in which monomer components, polymerization initiators, etc., are dissolved in a solvent, heated to polymerize, and a polymer solution containing the polymer is obtained.

[0090] Various common solvents can be used as solvents in solution polymerization. Examples of such solvents (polymerization solvents) include aromatic hydrocarbons such as toluene, benzene, and xylene; esters such as ethyl acetate and n-butyl acetate; aliphatic hydrocarbons such as n-hexane and n-heptane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. Solvents can be used individually or in combination of two or more.

[0091] The amount of solvent used is not particularly limited, but is preferably 10 parts by mass or more and 1000 parts by mass or less relative to the total monomer components constituting the polymer (100 parts by mass). The upper limit of the amount of solvent used is more preferably 500 parts by mass, and the lower limit is more preferably 50 parts by mass.

[0092] Polymerization initiators used in solution polymerization are not particularly limited, but include peroxide-based polymerization initiators and azo-based polymerization initiators. Peroxide-based polymerization initiators are not particularly limited, but include peroxycarbonates, ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, and peroxyesters. More specifically, examples include benzoyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, and 1,1-bis(t-butylperoxy)cyclododecane. The azo polymerization initiators are not particularly limited, but include 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylpropionic acid)dimethyl, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1'-azobis(cyclohexane-1-carbonitride), 2,2'-azobis(2,4,4-trimethylpentane), and 4,4'-azobis Examples include -4-cyanovaleric acid, 2,2'-azobis(2-amidinopropane)dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis(2-methylpropionamidine)disulfate, 2,2'-azobis(N,N'-dimethyleneisobutylamidine)hydrochloride, and 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate. Polymerization initiators can be used alone or in combination of two or more.

[0093] The amount of polymerization initiator used is not particularly limited, but is preferably 0.01 parts by mass or more and 5 parts by mass or less relative to the total monomer components constituting the polymer (100 parts by mass). The upper limit of the amount of polymerization initiator used is more preferably 3 parts by mass, and the lower limit is more preferably 0.05 parts by mass.

[0094] In solution polymerization, the heating temperature during polymerization is not particularly limited, but is, for example, 50°C to 80°C. The heating time is not particularly limited, but is, for example, 1 hour to 24 hours.

[0095] The weight-average molecular weight of the polymer is not particularly limited, but is preferably between 100,000 and 5,000,000. The upper limit of the weight-average molecular weight is more preferably 4,000,000, even more preferably 3,000,000, and the lower limit is more preferably 200,000, even more preferably 300,000. When the weight-average molecular weight is 100,000 or more, the cohesive force is reduced, which effectively suppresses the problem of adhesive residue remaining on the surface of the adherend after the electro-peelable adhesive layer has been removed. Furthermore, when the weight-average molecular weight is 5,000,000 or less, it effectively suppresses the problem of insufficient wettability on the surface of the adherend after the electro-peelable adhesive layer has been removed.

[0096] The weight-average molecular weight was obtained by measuring using gel permeation chromatography (GPC). More specifically, for example, using a GPC measuring device such as the "HLC-8220GPC" (manufactured by Tosoh Corporation), the measurement was performed under the following conditions, and the value was calculated using the standard polystyrene equivalent. (Weight-average molecular weight measurement conditions) ・Sample concentration: 0.2% by mass (tetrahydrofuran solution) ・Sample injection volume: 10 μL ・Sample column: TSKguardcolumn SuperHZ-H (1 tube) + TSKgel SuperHZM-H (2 tubes) ・Reference column: TSKgel SuperH-RC (1 tube) ・Eluent: Tetrahydrofuran (THF) ・Flow rate: 0.6 mL / min ・Detector: Differential refractometer (RI) ・Column temperature (measurement temperature): 40°C

[0097] The glass transition temperature (Tg) of the polymer is not particularly limited, but it is preferably 0°C or lower because it suppresses the decrease in initial adhesive strength, more preferably -10°C or lower, and even more preferably -20°C or lower. Furthermore, it is particularly preferable to have a temperature of -40°C or lower because the rate of decrease in adhesive strength due to voltage application is particularly large, and most preferably -50°C or lower.

[0098] The glass transition temperature (Tg) can be calculated, for example, based on the following equation (Y) (Fox equation): 1 / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wn / Tgn (Y) [In equation (Y), Tg is the glass transition temperature of the polymer (unit: K), Tgi (i = 1, 2, ..., n) is the glass transition temperature when monomer i forms a homopolymer (unit: K), and Wi (i = 1, 2, ..., n) represents the mass fraction of monomer i in the total monomer components]. The above equation (Y) is the calculation formula when the polymer is composed of n types of monomer components: monomer 1, monomer 2, ..., monomer n.

[0099] The glass transition temperature when forming a homopolymer refers to the glass transition temperature of the homopolymer of the monomer in question, and specifically refers to the glass transition temperature (Tg) of a polymer formed using only one monomer (sometimes referred to as "monomer X") as the monomer component. The specific values ​​are given in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989). Note that the glass transition temperature (Tg) of a homopolymer not listed in the aforementioned literature refers to a value obtained, for example, by the following measurement method: In a reactor equipped with a thermometer, stirrer, nitrogen inlet tube, and reflux condenser, 100 parts by mass of monomer X, 0.2 parts by mass of 2,2'-azobisisobutyronitrile, and 200 parts by mass of ethyl acetate as the polymerization solvent are added, and the mixture is stirred for 1 hour while introducing nitrogen gas. After removing oxygen from the polymerization system in this way, the temperature is raised to 63°C and the reaction is carried out for 10 hours. Then, the mixture is cooled to room temperature to obtain a homopolymer solution with a solid content of 33% by mass. Next, this homopolymer solution is cast onto a release liner and dried to produce a test sample (sheet-like homopolymer) with a thickness of approximately 2 mm. Then, approximately 1-2 mg of this test sample is weighed into an aluminum open cell, and the reversing heat flow (specific heat component) behavior of the homopolymer is obtained using a temperature-modulated DSC (product name "Q-2000," manufactured by T.A. Instruments Corporation) at a heating rate of 5°C / min under a nitrogen atmosphere of 50 ml / min. Referring to JIS-K-7121, the glass transition temperature (Tg) of the homopolymer is defined as the temperature at the point where a line equidistant in the vertical axis direction from the line extending from the low-temperature baseline and the high-temperature baseline of the obtained reversing heat flow intersects with the curve of the step-like change portion of the glass transition.

[0100] The polymer content in the adhesive composition according to the embodiment of the present invention is preferably 50% by mass or more and 99.9% by mass or less, based on the total amount of the adhesive composition (100% by mass), with the upper limit being more preferably 99.5% by mass, even more preferably 99% by mass, and the lower limit being more preferably 60% by mass, even more preferably 70% by mass.

[0101] (Ionic Substance) The adhesive composition according to an embodiment of the present invention preferably contains an ionic substance. An ionic substance is a general term for substances that exist in a state other than gas at normal temperature (25°C) and are composed of at least a pair of anions and cations. The ionic substance at normal temperature (25°C) may be in a solid, liquid, or intermediate state between solid and liquid (e.g., liquid crystal, soft viscous crystal, viscous solid, viscous liquid). The state of the ionic substance at normal temperature (25°C) depends on its molecular structure. Examples of ionic substances include ionic liquids, ionic crystals, soft viscous ionic crystals, alkali metal salts, alkaline earth metal salts, organic quaternary ammonium salts, etc. From the perspective of achieving good electrical peelability, the ionic substance contained in the adhesive composition is preferably an ionic liquid. An ionic liquid is a molten salt (room temperature molten salt) composed of a pair of anions and cations and is liquid at 25°C.

[0102] The anion of the ionic substance is, for example, (FSO ２ ) ２ N － , (CF ３ SO ２ ) ２ N － , (CF ３ CF ２ SO ２ ) ２ N － , (CF ３ SO ２ ) ３ C － , Br － , AlCl ４ － , Al ２ Cl ７ － , NO ３ － , BF ４ － , PF ６ － , CH ３ COO － , CF ３ COO － , CF ３ CF ２ CF ２ COO－ CF ３ SO ３ － CF ３ (CF ２ ) ３ SO ３ － AsF ６ － SbF ６ － , and F (HF) ｎ － These are some examples. Among them, as for anions, (FSO ２ ) ２ N － [Bis(fluorosulfonyl)imide anion] and (CF ３ SO ２ ) ２ N － Anions of sulfonylime compounds such as [bis(trifluoromethanesulfonyl)imide anion] are preferred because they are chemically stable and suitable for improving electrolysis. In other words, the anion of the ionic substance is preferably at least one selected from the group consisting of bis(fluorosulfonyl)imide anion and / or bis(trifluoromethanesulfonyl)imide anion.

[0103] In ionic materials, the cation is preferably at least one selected from the group consisting of nitrogen-containing onium cations, sulfur-containing onium cations, and phosphorus-containing onium cations, as this is chemically stable and suitable for improving electrolysis properties. Imidazolium-based, ammonium-based, pyrrolidinium-based, and pyridinium-based cations are more preferred.

[0104] Examples of imidazolium-based cations include 1-methylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-propyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-pentyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-heptyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-nonyl-3-methylimidazolium cation, 1-undecyl-3-methylimidazolium cation, and 1-dodecyl-3-methylimidazolium cation. Examples include mucation, 1-tridecyl-3-methylimidazolium cation, 1-tetradecyl-3-methylimidazolium cation, 1-pentadecyl-3-methylimidazolium cation, 1-hexadecyl-3-methylimidazolium cation, 1-heptadecyl-3-methylimidazolium cation, 1-octadecyl-3-methylimidazolium cation, 1-undecyl-3-methylimidazolium cation, 1-benzyl-3-methylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, and 1,3-bis(dodecyl)imidazolium cation.

[0105] Examples of pyridinium-based cations include 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, and 1-octyl-4-methylpyridinium cation.

[0106] Examples of pyrrolidinium-based cations include 1-ethyl-1-methylpyrrolidinium cation and 1-butyl-1-methylpyrrolidinium cation.

[0107] Examples of ammonium-based cations include tetraethylammonium cation, tetrabutylammonium cation, methyltrioctylammonium cation, tetradecitrihexylammonium cation, glycidyltrimethylammonium cation, and trimethylaminoethyl acrylate cation.

[0108] As for the ionic material, from the viewpoint of significantly reducing the rate of decrease in adhesive strength when voltage is applied, it is preferable to select a cation with a molecular weight of 160 or less as the constituent cation, and the above (FSO ２ ) ２ N － [Bis(fluorosulfonyl)imide anion] or (CF ３ SO ２ ) ２ N － An ionic substance containing a [bis(trifluoromethanesulfonyl)imide anion] and a cation with a molecular weight of 160 or less is particularly preferred. Examples of cations with a molecular weight of 160 or less include 1-methylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-propyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-pentyl-3-methylimidazolium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-ethyl-1-methylpyrrolidinium cation, 1-butyl-1-methylpyrrolidinium cation, tetraethylammonium cation, glycidyltrimethylammonium cation, and trimethylaminoethyl acrylate cation.

[0109] Furthermore, as cations of ionic substances, cations represented by the following formulas (2-A) to (2-D) are also preferred.

[0110]

[0111] R in equation (2-A) １ R represents a hydrocarbon group having 4 to 10 carbon atoms (preferably a hydrocarbon group having 4 to 8 carbon atoms, more preferably a hydrocarbon group having 4 to 6 carbon atoms), and may contain heteroatoms. ２ and R ３R represents the same or different hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms (preferably a hydrocarbon group having 1 to 8 carbon atoms, more preferably a hydrocarbon group having 2 to 6 carbon atoms, and even more preferably a hydrocarbon group having 2 to 4 carbon atoms), and may also contain heteroatoms. However, if the nitrogen atom forms a double bond with an adjacent carbon atom, ３ It does not exist.

[0112] R in equation (2-B) ４ R represents a hydrocarbon group having 2 to 10 carbon atoms (preferably a hydrocarbon group having 2 to 8 carbon atoms, more preferably a hydrocarbon group having 2 to 6 carbon atoms), and may contain heteroatoms. ５ , R ６ , and R ７ These represent, either identically or differently, a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms (preferably a hydrocarbon group having 1 to 8 carbon atoms, more preferably a hydrocarbon group having 2 to 6 carbon atoms, and even more preferably a hydrocarbon group having 2 to 4 carbon atoms), and may also contain heteroatoms.

[0113] R in equation (2-C) ８ R represents a hydrocarbon group having 2 to 10 carbon atoms (preferably a hydrocarbon group having 2 to 8 carbon atoms, more preferably a hydrocarbon group having 2 to 6 carbon atoms), and may contain heteroatoms. ９ , R １０ , and R １１ These represent, either identically or differently, a hydrogen atom or a hydrocarbon group having 1 to 16 carbon atoms (preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 8 carbon atoms), and may also contain heteroatoms.

[0114] In formula (2-D), X represents a nitrogen, sulfur, or phosphorus atom, and R １２ , R １３ , R １４ , and R １５ R represents a hydrocarbon group having 1 to 16 carbon atoms, either identical or different, (preferably a hydrocarbon group having 1 to 14 carbon atoms, more preferably a hydrocarbon group having 1 to 10 carbon atoms, even more preferably a hydrocarbon group having 1 to 8 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 6 carbon atoms), and may contain heteroatoms. However, if X is a sulfur atom, R １２ It does not exist.

[0115] The molecular weight of cations in ionic materials is, for example, 500 or less, preferably 400 or less, more preferably 300 or less, even more preferably 250 or less, particularly preferably 200 or less, and most preferably 160 or less. It is also usually 50 or more. It is believed that cations in ionic materials have the property of moving towards the cathode side when a voltage is applied within the electropenetrating adhesive layer, and becoming concentrated near the interface between the electropenetrating adhesive layer and the adherend (more specifically, the conductive layer in the adherend), or near the interface between the electropenetrating adhesive layer and the conductive substrate. In the present invention, this results in a decrease in adhesive strength during voltage application relative to the initial adhesive strength, leading to electropenetration. Cationic materials with small molecular weights, such as 500 or less, are preferable because their movement towards the cathode side within the electropenetrating adhesive layer is easier, and they are suitable for increasing the rate of decrease in adhesive strength during voltage application.

[0116] Examples of commercially available ionic substances include "Elexel AS-110," "Elexel MP-442," "Elexel IL-210," "Elexel MP-471," "Elexel MP-456," and "Elexel AS-804" from Daiichi Kogyo Seiyaku Co., Ltd., "HMI-FSI" from Mitsubishi Materials Corporation, "CIL-312" and "CIL-313" from Nippon Carlit Co., Ltd., and "ETHYLMETHYLPYRROLIDINIUM BIS (FLUOROSULFONYL) IMIDE" from Boron Molecular Inc.

[0117] The ionic conductivity of the ionic material is preferably between 0.0001 mS / cm and 20 mS / cm. The upper limit of the ionic conductivity can be, for example, 15 mS / cm or 10 mS / cm. The lower limit of the ionic conductivity is more preferably 0.1 mS / cm, and even more preferably 0.3 mS / cm. An ionic conductivity of 0.0001 mS / cm or higher is preferable because it sufficiently reduces the adhesive strength after voltage is applied. Furthermore, an ionic conductivity of 20 mS / cm or lower is preferable because it suppresses the influence of weak external currents, and electrolysis can only occur when voltage is intentionally applied. Having an ionic conductivity within this range allows for sufficient reduction of adhesive strength even at low voltages. The ionic conductivity can be measured, for example, by the AC impedance method using a Solartron 1260 frequency response analyzer.

[0118] In the adhesive composition according to the embodiment of the present invention, the content (amount of blending) of the ionic liquid is preferably 0.5 parts by mass or more per 100 parts by mass of polymer from the viewpoint of reducing adhesive strength during voltage application, and preferably 30 parts by mass or less from the viewpoint of increasing initial adhesive strength. From the same viewpoint, it is more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, particularly preferably 10 parts by mass or less, and most preferably 5 parts by mass or less. Furthermore, it is more preferably 0.6 parts by mass or more, even more preferably 0.8 parts by mass or more, particularly preferably 1.0 part by mass or more, and most preferably 1.5 parts by mass or more.

[0119] (Other Components) The adhesive composition according to the embodiment of the present invention may contain one or more components other than polymers and ionic substances (hereinafter sometimes referred to as "other components"), as necessary, to the extent that they do not impair the effects of the present invention. The other components that may be contained in the adhesive composition according to the embodiment of the present invention will be described below.

[0120] Adhesive compositions according to embodiments of the present invention may optionally contain a crosslinking agent for the purpose of improving creep and shear properties by crosslinking the polymer. Examples of crosslinking agents include isocyanate-based crosslinking agents, carbodiimide-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, peroxide-based crosslinking agents, urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, and amine-based crosslinking agents. Examples of isocyanate-based crosslinking agents include toluene diisocyanate and methylene bisphenyl isocyanate. Examples of epoxy-based crosslinking agents include N,N,N',N'-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane and 1,6-hexanediol diglycidyl ether. If a crosslinking agent is included, the preferred content is 0.1 parts by mass or more and 50 parts by mass or less per 100 parts by mass of polymer. The crosslinking agent can be used alone or in combination of two or more types.

[0121] The adhesive composition according to the embodiment of the present invention may optionally contain polyethylene glycol to assist in the movement of the ionic liquid when a voltage is applied. Polyethylene glycol having a number average molecular weight of 200 to 6000 can be used. When polyethylene glycol is included, the content is preferably 0.1 parts by mass or more and 30 parts by mass or less per 100 parts by mass of polymer.

[0122] The adhesive composition according to the embodiment of the present invention may optionally contain a conductive filler for the purpose of imparting conductivity to the adhesive composition. The conductive filler is not particularly limited, and general known or conventional conductive fillers can be used, such as graphite, carbon black, carbon fiber, or metal powders such as silver or copper. When a conductive filler is included, the content is preferably 0.1 parts by mass or more and 200 parts by mass or less per 100 parts by mass of polymer.

[0123] The adhesive composition according to the embodiment of the present invention may also contain various additives such as fillers, plasticizers, antioxidants, antioxidants, pigments (dyes), flame retardants, solvents, water, surfactants (leveling agents), rust inhibitors, tackifying resins, corrosion inhibitors, and antistatic agents. The total content of these components is not particularly limited as long as the effects of the present invention are achieved, but is preferably 0.01 parts by mass or more and 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of polymer.

[0124] Examples of fillers include silica, iron oxide, zinc oxide, aluminum oxide, titanium oxide, barium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, pyrophyllite clay, kaolin clay, and calcined clay. For plasticizers, commonly known and conventional plasticizers used in general resin compositions can be used, such as oils like paraffin oil and process oil; liquid rubbers like liquid polyisoprene, liquid polybutadiene, and liquid ethylene-propylene rubber; tetrahydrophthalic acid, azelaic acid, benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, citric acid, and their derivatives; dioctyl phthalate (DOP), dibutyl phthalate (DBP), dioctyl adipate, diisononyl adipate (DINA), and isodecyl succinate. Examples of anti-aging agents include hindered phenol compounds, aliphatic and aromatic hindered amine compounds, etc. Examples of antioxidants include butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA). Examples of pigments include inorganic pigments such as titanium dioxide, zinc oxide, ultramarine, red iron oxide, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride salts, sulfates, azo pigments, and organic pigments such as copper phthalocyanine pigments. Examples of rust inhibitors include zinc phosphate, tannic acid derivatives, phosphate esters, basic sulfonates, and various rust-inhibiting pigments. Examples of adhesion promoters include titanium coupling agents and zirconium coupling agents. Examples of antistatic agents generally include quaternary ammonium salts, or hydrophilic compounds such as polyglycolic acid and ethylene oxide derivatives. Examples of tackifying resins include rosin-based tackifying resins, terpene-based tackifying resins, phenol-based tackifying resins, hydrocarbon-based tackifying resins, ketone-based tackifying resins, as well as polyamide-based tackifying resins, epoxy-based tackifying resins, and elastomer-based tackifying resins. These tackifying resins can be used individually or in combination of two or more types.Examples of corrosion inhibitors include carbodiimide compounds, adsorption-type inhibitors, and chelate-forming metal deactivators. For example, those described in Japanese Patent Publication No. 2019-059908 can be used.

[0125] The adhesive composition according to the embodiment of the present invention is not particularly limited, but can be produced by appropriately stirring and mixing a polymer, an ionic substance, an additive, and, if necessary, a crosslinking agent, polyethylene glycol, a conductive filler, etc.

[0126] In the embodiment of the present invention, the thickness of the electropenetrating adhesive layer is preferably 1 μm or more and 1000 μm or less, from the viewpoint of initial adhesive strength. The upper limit of the electropenetrating adhesive layer is more preferably 500 μm, even more preferably 300 μm, even more preferably 200 μm, even more preferably 150 μm, even more preferably 100 μm, even more preferably 80 μm, even more preferably 70 μm, even more preferably 60 μm, and even more preferably 50 μm. The lower limit is more preferably 5 μm, even more preferably 10 μm, even more preferably 20 μm, and even more preferably 30 μm.

[0127] <Conductive Substrate> The conductive substrate of the joint according to the embodiment of the present invention is not particularly limited as long as it has at least one conductive layer. Figures 2 to 5 show examples of the laminated structure of the joint according to the embodiment of the present invention. Examples of the structure of the conductive substrate of the joint according to the embodiment of the present invention include, for example, the conductive substrate X1 shown in Figure 2, the conductive substrate X2 showing a laminated structure in Figure 3, the conductive substrate X3 showing a laminated structure in Figure 4, and the conductive substrate X4 showing a laminated structure in Figure 5. The conductive substrate X1 consists only of a conductive substrate 5. The conductive substrate X2 has a layer structure of a conductive layer 1 and a substrate 2. The conductive substrate X3 has a layer structure of a conductive layer 1, other adhesive layers 6, and a substrate 2. The conductive substrate X4 has a layer structure of an electric current-carrying substrate 7 (substrate 8 and other conductive layers 9), other adhesive layers 6, and a substrate 2.

[0128] The conductive substrate 5 is not particularly limited as long as the adherend surface is a conductive substrate, but it is preferably an adherend having a metallic adherend surface. Examples of metallic adherend surfaces include surfaces made of conductive metals, such as aluminum, copper, iron, magnesium, tin, gold, silver, and lead, and among these, surfaces made of metals containing iron or aluminum (e.g., stainless steel) are preferred. Examples of adherends having a metallic adherend surface include sheets, parts, and plates made of metals, such as aluminum, copper, iron, magnesium, tin, gold, silver, and lead. The surface resistance value of the conductive substrate 5 is, for example, 1.0 × 10⁻⁶. ４ Ω / □ or less, preferably 1.0 × 10 ３ The resistance is less than or equal to Ω / □. The surface resistance can be measured by the four-terminal method in accordance with JIS K 7194.

[0129] The descriptions of the conductive layer 1 and substrate 2 in the above-described description of the adherend 3 can be directly applied to the conductive layer 1 and substrate 2.

[0130] The other adhesive layer 6 is a layer made of an adhesive composition that does not contain ionic substances, and is formed from a conventionally known adhesive composition.

[0131] The base material 8 is not particularly limited, but examples include paper-based base materials such as paper, fiber-based base materials such as cloth and nonwoven fabric, plastic-based base materials such as films and sheets made of various plastics (polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, acrylic resins such as polymethyl methacrylate, etc.), and laminates thereof. The base material may have a single layer or a multi-layer form. The base material may be subjected to various treatments as needed, such as back treatment, antistatic treatment, and primer treatment.

[0132] The other conductive layer 9 is a conductive layer other than the conductive layer 2 formed from the conductive composition according to the embodiment of the present invention. The conductive layer 9 is not particularly limited as long as it is a layer having conductivity, but examples include metal (e.g., aluminum, magnesium, copper, iron, tin, gold, etc.) foils, metal plates (e.g., aluminum, magnesium, copper, iron, tin, silver, etc.), metal-based substrates such as foils and plates of alloys mainly composed of metals (e.g., aluminum, magnesium, copper, iron, tin, gold, etc.), conductive polymers, and the like. Also, it may be a film formed by sputtering or vapor deposition of a metal or alloy provided on the substrate 8. The surface resistance value of the other conductive layer 9 is, for example, 1.0×10 ４ Ω / sq or less, preferably 1.0×10 ３ Ω / sq or less. The surface resistance value can be measured by the four-terminal method in accordance with JIS K 7194.

[0133] The energization substrate 7 is not particularly limited as long as it is a substrate having a conductive layer (for energization), and examples include those having a metal layer formed on the surface of the substrate. For example, a metal layer is formed on the surface of the substrates exemplified above by methods such as plating, chemical vapor deposition, and sputtering. Examples of the metal layer include the metals, alloys mainly composed of metals, metal plates, and conductive polymers exemplified above.

[0134] From the viewpoint of adhesive strength, the thickness of the other adhesive layer 6 is preferably 1 μm or more and 2000 μm or less. The upper limit of the thickness of the other adhesive layer 6 is more preferably 1000 μm, further preferably 500 μm, particularly preferably 100 μm, and the lower limit is more preferably 3 μm, further preferably 5 μm, particularly preferably 8 μm.

[0135] The thickness of the substrate 8 is preferably 10 μm or more and 1000 μm or less. The upper limit of the thickness is more preferably 500 μm, further preferably 300 μm, particularly preferably 100 μm, and the lower limit is more preferably 12 μm, further preferably 25 μm.

[0136] The thickness of the conductive layer 9 is preferably 0.001 μm or more and 1000 μm or less. The upper limit of the thickness is more preferably 500 μm, even more preferably 300 μm, even more preferably 50 μm, and even more preferably 10 μm, and the lower limit is more preferably 0.01 μm, even more preferably 0.03 μm, and even more preferably 0.05 μm.

[0137] The thickness of the conductive substrate 7 is preferably 10 μm or more and 1000 μm or less. The upper limit of the thickness is more preferably 500 μm, even more preferably 300 μm, and particularly preferably 100 μm, while the lower limit is more preferably 12 μm, and even more preferably 25 μm.

[0138] In the bonded body according to the embodiment of the present invention, a coating layer may be further provided between the other conductive layer and the electropenetrating adhesive layer. By providing the additional coating layer, the ionic liquid contained in the electropenetrating adhesive layer acts as a barrier to penetrate the other conductive layer when a voltage is applied, thereby preventing the other conductive layer from peeling off from the substrate or the like.

[0139] The coating layer is a layer mainly composed of resin or inorganic material, and can be formed from a resin composition mainly composed of resin components or a composition mainly composed of inorganic material. The coating layer may be made from at least one resin selected from polyester resins, acrylic resins, epoxy resins, or urethane resins, or from SiNx, SiOx, Al ２ O ３ Preferably, it contains at least one inorganic substance selected from Ni and NiCr.

[0140] <Method for Manufacturing the Joint> The method for manufacturing the joint according to the embodiment of the present invention can be a known or conventional manufacturing method. For the electropenetrating adhesive layer in the joint according to the embodiment of the present invention, one method is to apply a solution obtained by dissolving the adhesive composition according to this embodiment in a solvent as needed onto a release liner, and then drying and / or curing it. For other adhesive layers, one method is to apply a solution obtained by dissolving an adhesive composition that does not contain ionic substances in a solvent as needed onto a release liner, and then drying and / or curing it. The solvent and release liner can be those listed above.

[0141] Conventional coaters (e.g., gravure roll coaters, reverse roll coaters, kiss roll coaters, dip roll coaters, bar coaters, knife coaters, spray roll coaters, etc.) can be used for application.

[0142] By the above method, an electrorelease adhesive layer and other adhesive layers can be manufactured, and a bonded body according to the embodiment of the present invention can be manufactured by laminating the electrorelease adhesive layer and other adhesive layers onto an adherend, a conductive layer, a substrate, a conductive substrate, a substrate, other conductive layers, or an electrically conductive substrate as appropriate. Alternatively, instead of a release liner, an adhesive composition may be applied to an adherend, a conductive layer, a substrate, a substrate, other conductive layers, or an electrically conductive substrate to manufacture the bonded body.

[0143] [Jointed Body and Method for Separating Joined Body] The jointed body according to the embodiment of the present invention is a jointed body in which an electrorelease adhesive sheet comprising a conductive substrate and an electrorelease adhesive layer containing an ionic substance is bonded to an adherend having the conductive layer described above, wherein the electrorelease adhesive layer in the electrorelease adhesive sheet is bonded to the conductive layer side of the adherend having the conductive layer. Examples of the laminated structure of the jointed body according to the embodiment of the present invention include the laminated structure of the jointed body according to the embodiment of the present invention shown in Figures 2 to 5. However, in all cases, the adherend 3 having the conductive layer and the conductive substrate (X1 to X4) are bonded together by the electrorelease adhesive layer 4.

[0144] A method for separating a bonded body according to an embodiment of the present invention is a method for separating a bonded body in which an electro-removable adhesive sheet comprising a conductive substrate and an electro-removable adhesive layer containing an ionic substance is adhered to an adherend having a conductive layer according to an embodiment of the present invention, wherein a voltage is applied to the electro-removable adhesive layer to separate the electro-removable adhesive sheet and the adherend.

[0145] In the bonded structure, the electropenetrating adhesive layer is attached to the conductive layer side of the adherend having a conductive layer, and the bonded structure is separated by applying a voltage to the electropenetrating adhesive layer via the conductive layer and conductive substrate. In other words, the separation of the bonded structure according to the embodiment of the present invention can be achieved by applying a voltage to the electropenetrating adhesive layer, thereby generating a potential difference in the thickness direction of the electropenetrating adhesive layer.

[0146] For example, if the bonded body has a laminated structure similar to bonded body Y1 shown in Figure 2, it can be separated by applying current to the conductive layer 1 and the conductive substrate 5 and applying a voltage to the electrorelease adhesive layer. If the bonded body has a laminated structure similar to bonded body Y2 shown in Figure 3, it can be separated by applying current to the conductive layers 1 on both sides and applying a voltage to the electrorelease adhesive layer. If the bonded body has a laminated structure similar to bonded body Y3 shown in Figure 4, it can be separated by applying current to the conductive layers 1 on both sides and applying a voltage to the electrorelease adhesive layer. If the bonded body has a laminated structure similar to bonded body Y4 shown in Figure 5, it can be separated by applying current to the conductive layer 1 and the other conductive layers 9 and applying a voltage to the electrorelease adhesive layer.

[0147] It is preferable to apply current by connecting terminals to one end and the other end of the joint so that a voltage is applied to the entire electro-peelable adhesive layer. Note that the above-mentioned one end and the other end may be part of the conductive layer and the conductive substrate. When separating, water may be added to the interface between the conductive layer and the electro-peelable adhesive layer, or the interface between the conductive substrate and the electro-peelable adhesive layer, before applying the voltage.

[0148] Current is preferably applied by connecting electrodes to the conductive layer 1 and the conductive substrates (X1 to X4), and it is preferable to separate at least the electrorelease adhesive layer 4 from the conductive layer 1 by applying a voltage. Alternatively, the electrorelease adhesive layer 4 may be separated from the conductive substrates (X1 to X4). Depending on the adhesive interface to be separated, the electrodes may be connected by connecting the cathode to the conductive layer 1 and the anode to the conductive substrates (X1 to X4), or by connecting the anode to the conductive layer 1 and the cathode to the conductive substrates (X1 to X4).

[0149] <Initial Adhesion, Peeling Force Reduction Rate> The adhesion strength of the electropeelable adhesive layer in the bonded body according to the embodiment of the present invention can be evaluated by various methods, but for example, it can be evaluated by the 180° peel test described in the Examples section.

[0150] The electropenetrating adhesive layer according to this embodiment preferably has an initial adhesive strength of 1.5 N / cm or more, more preferably 2.0 N / cm or more, even more preferably 2.5 N / cm or more, particularly preferably 3.0 N / cm or more, and most preferably 3.5 N / cm or more, measured by a 180° peel test after forming a bonded body as described in the Examples section and leaving it in a predetermined temperature and humidity environment for a predetermined period of time. The initial adhesive strength can be, for example, 4.0 N / cm or more, 5.0 N / cm or more, or 6.0 N / cm or more. When the initial adhesive strength is 1.5 N / cm or more, the adhesion to the adherend is sufficient, and the adherend is less likely to peel off or shift.

[0151] In this embodiment, the electropenetrating adhesive layer is formed as described in the Examples section, left for a predetermined period of time in an environment with a predetermined temperature and humidity, a voltage of 30V is applied for 30 seconds, and it is preferable that the adhesive strength (electropenetrating force) measured in a 180° peel test immediately after stopping the voltage application is sufficiently small compared to the initial adhesive strength.

[0152] Specifically, the peel force reduction rate, calculated from the electropenetrating force measured by the above method and the initial adhesive force using the following formula, is preferably 30% or more, and preferably 60% or more. The above-mentioned predetermined temperature and humidity and period are preferably 22°C, 50% RH, and 72 hours. [(Initial Adhesion) - (Electropenetrating Force)] × 100 / Initial Adhesion = Peel Force Reduction Rate (%)

[0153] The applied voltage and voltage application time during electrolysis are not limited to those described above, and are not particularly limited as long as the electrolytically removable adhesive layer can be peeled off from at least one of the conductive layer and the conductive substrate. Preferred ranges are shown below. The applied voltage is preferably 1V or more, more preferably 3V or more, and even more preferably 6V or more. It is also preferably 100V or less, more preferably 50V or less, and even more preferably 30V or less. The applied voltage may be, for example, 15V or less or 10V or less. The voltage application time is preferably 600 seconds or less, more preferably 300 seconds or less, even more preferably 180 seconds or less, even more preferably 120 seconds or less, even more preferably 60 seconds or less, and particularly preferably 30 seconds or less. The voltage application time can be, for example, 20 seconds or less or 10 seconds or less. In such cases, workability is excellent. Also, the shorter the application time, the better, but it is usually 1 second or more.

[0154] As described above, the following matters are disclosed in this specification: <1> A conductive composition comprising a resin component, wherein the contact angle of 1-ethylimidazole to a conductive layer formed by the conductive composition after 1 second of droplet deposition is 16° or more and 35° or less. <2> The conductive composition according to <1>, wherein the surface resistance of the conductive layer is 8000 Ω / □ or less. <3> The conductive composition according to <1> or <2>, wherein the surface resistance of the conductive layer is 3000 Ω / □ or less. <4> The conductive composition according to any one of <1> to <3>, wherein the arithmetic mean surface roughness Ra of the conductive layer is 0.65 μm or less. <5> The conductive composition according to any one of <1> to <4>, wherein the contact angle of water to the conductive layer after 1 second of droplet deposition is 110° or less. <6> The conductive composition according to any one of <1> to <5>, wherein the glass transition temperature Tg of the resin component after curing is higher than 50°C. <7> A conductive composition according to any one of <1> to <6>, for forming a conductive layer to be attached to an electropenetrating adhesive layer containing an ionic substance. <8> A conductive layer formed by the conductive composition according to any one of <1> to <6>. <9> A conductive layer formed by a conductive composition containing a resin component, wherein the contact angle of 1-ethylimidazole to the conductive layer 1 second after droplet placement is 16° or more and 35° or less. <10> The conductive layer according to <9>, wherein the surface resistance of the conductive layer is 8000 Ω / □ or less. <11> The conductive layer according to <9> or <10>, wherein the surface resistance of the conductive layer is 3000 Ω / □ or less. <12> The conductive layer according to any one of <9> to <11>, wherein the arithmetic mean surface roughness Ra of the conductive layer is 0.65 μm or less. <13> The conductive layer according to any one of <9> to <12>, wherein the contact angle of water to the conductive layer 1 second after droplet placement is 110° or less. <14> The conductive layer according to any one of <9> to <13>, wherein the glass transition temperature Tg of the resin component after curing is higher than 50°C. <15> The conductive layer according to any one of <9> to <14>, which is attached to an electropenetrating adhesive layer containing an ionic substance.<16> A substrate having a conductive layer formed by any one of the conductive compositions described in <1> to <6>, or a conductive layer described in any one of the items <9> to <14>. <17> A bond comprising a substrate having a conductive layer, an adhesive layer, and a conductive substrate laminated in that order, wherein the adhesive layer is attached to the conductive layer side of the substrate, and the conductive layer is formed by any one of the conductive compositions described in <1> to <6>, or a conductive layer described in any one of the items <9> to <14>. <18> The bond according to <17>, wherein the adhesive layer is an electropenetrating adhesive layer containing an ionic substance. <19> The bond according to <18>, wherein the ionic substance is an ionic liquid. <20> The bond according to <17>, wherein the adhesive layer is a pressure-sensitive adhesive layer. <21> A method for separating a bonded body comprising an electropenetrating adhesive sheet comprising a conductive substrate and an electropenetrating adhesive layer containing an ionic substance, and an adherend described in <16>, the method comprising applying a voltage to the electropenetrating adhesive layer to separate the electropenetrating adhesive sheet and the adherend.

[0155] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to these examples.

[0156] (Preparation of Acrylic Polymer Solution) As monomer components, 87 parts by mass of n-butyl acrylate (BA), 10 parts by mass of 2-methoxyethyl acrylate (MEA), 3 parts by mass of acrylic acid (AA), and 150 parts by mass of ethyl acetate as a polymerization solvent were placed in a separable flask and stirred for 1 hour while introducing nitrogen gas. After removing oxygen from the polymerization system in this way, 0.2 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) was added as a polymerization initiator, and the mixture was heated to 63°C and reacted for 6 hours. Then, ethyl acetate was added to obtain an acrylic polymer solution with a solid content of 30% by mass. The weight-average molecular weight of the obtained acrylic polymer 1 was 700,000.

[0157] [Example 1] (Preparation of electropenetrating adhesive layer) The acrylic polymer (solution), crosslinking agent, ionic substance, and additives (adsorption-type inhibitor, chelate-forming metal deactivator) obtained above were mixed with ethyl acetate and stirred to obtain each electropenetrating adhesive composition (solution) with a solid content concentration of 25% by mass. The solid content concentration of the electropenetrating adhesive composition refers to the mass ratio of all components other than the solvent to the total mass of the electropenetrating adhesive composition.

[0158] Table 1 shows the proportions of each component. Note that the values ​​for each component in Table 1 represent parts by mass.

[0159] The obtained electro-peelable adhesive composition (solution) was applied to the peeled surface of a polyethylene terephthalate peel liner (product name "MRF38", manufactured by Mitsubishi Chemical Corporation) using an applicator to achieve a uniform thickness. Next, it was heated and dried at 150°C for 3 minutes, and the peeled surface of the polyethylene terephthalate peel liner (product name "MRE38", manufactured by Mitsubishi Chemical Corporation) was laminated onto the electro-peelable adhesive using a hand roller to obtain an electro-peelable adhesive layer with a thickness of 50 μm.

[0160] The abbreviations for ionic substances, crosslinking agents, and additives (adsorption-type inhibitors and chelate-forming metal deactivators) in Table 1 are as follows:

[0161] <Ionic Substances> AS-110: Cation: 1-ethyl-3-methylimidazolium cation, Anion: bis(fluorosulfonyl)imide anion, Product name: "Elexel AS-110", Manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Ionic Substance A: Cation: 1-ethyl-1-methylpyrrolidinium, Anion: bis(fluorosulfonyl)imide anion, Product name: "ETHYLMETHYLPYRROLIDINIUM BIS(FLUOROSULFONYL)IMIDE", Manufactured by Boron Molecular Inc.

[0162] <Crosslinking agent> V-05: Polycarbodiimide resin, product name "Carbodilite V-05", manufactured by Nisshinbo Chemical Co., Ltd.

[0163] <Additives> AMINE O: 2-(8-heptadecene-1-yl)-4,5-dihydro-1H-imidazole-1-ethanol, trade name "AMINE O", manufactured by BASF Japan Ltd. Irgacor DSSG: Sodium sebacate, trade name "Irgacor DSSG", manufactured by BASF Japan Ltd. Irgamet 30: N,N-bis(2-ethylhexyl)-[(1,2,4-triazole-1-yl)methyl]amine, trade name "Irgamet 30", manufactured by BASF Japan Ltd. D-125: Polymerized rosin ester tackifier, trade name "Pencel D-125", manufactured by Arakawa Chemical Industries, Ltd.

[0164] (Preparation of single-sided electro-peelable adhesive sheet with substrate) The polyethylene terephthalate release liner (MRE38) of the obtained electro-peelable adhesive layer was peeled off, and the metal layer side of a metal-layered film (product name "1005CR", manufactured by Toray Film Processing Co., Ltd., thickness 25 μm) was bonded to the surface of the exposed electro-peelable adhesive layer to create a single-sided electro-peelable adhesive sheet with a substrate (electrical substrate).

[0165] (Preparation of a substrate having a conductive layer) 100 parts by mass of a hybrid product of polyimide resin and epoxy resin (Imitron #300IX-5, manufactured by Nakata Coating Co., Ltd.) (Resin A) were mixed with 20 parts by mass of carbon nanotubes (conductive material, Lamfil SPC-061, manufactured by Kusumoto Chemical Co., Ltd.) (abbreviated as CNT in the table), and the mixture was stirred and degassed at room temperature to obtain a conductive composition. The obtained conductive composition was coated onto a substrate (product name "Kapton 200H", thickness 200 gauge (50 μm), polyimide film, manufactured by Toray DuPont Co., Ltd.) using an applicator, and dried at 250°C for 30 minutes to form a conductive layer with a thickness of 10 μm on the polyimide film, thereby obtaining the substrate having a conductive layer of Example 1.

[0166] (Preparation of the bonded body) The release liner (MRF38) of the single-sided electropenetrating adhesive sheet with a substrate was peeled off, and the electropenetrating adhesive layer of the single-sided electropenetrating adhesive sheet was bonded to the conductive layer side of the adherend having a conductive layer in Example 1, thereby producing the bonded body of Example 1 consisting of an adherend having a conductive layer 3' / electropenetrating adhesive layer 4' / metal layered film (conductive substrate) 5'.

[0167] [Example 2] In the preparation of the adherend having a conductive layer, the bonded body of Example 2 was obtained in the same manner as in Example 1, except that the thickness of the conductive layer was changed to 20 μm.

[0168] [Example 3] In the preparation of the adherend having a conductive layer, the bonded body of Example 3 was obtained in the same manner as in Example 1, except that the amount of conductive material was changed to 100 parts by mass.

[0169] [Example 4] In the preparation of the adherend having a conductive layer, the bonded body of Example 4 was obtained in the same manner as in Example 1, except that the substrate was changed to glass (product name "EAGLE XG", manufactured by Corning).

[0170] [Example 5] In the preparation of the electropenetrating adhesive layer, the bond of Example 5 was obtained in the same manner as in Example 1, except that the ionic substance was changed to ionic substance A: cation: 1-ethyl-1-methylpyrrolidinium, anion: bis(fluorosulfonyl)imide anion, trade name "ETHYLMETHYLPYRROLIDINIUM BIS(FLUOROSULFONYL)IMIDE", manufactured by Boron Molecular Inc.

[0171] [Examples 6 and 7] In the preparation of the electropenetrating adhesive layer, the bonded bodies of Examples 6 and 7 were obtained in the same manner as in Example 1, except that the amount of ionic substance was changed.

[0172] [Example 8] (Preparation of a substrate having a conductive layer) A conductive composition was obtained by adding 20 parts by mass of carbon nanotubes (Lamfil SPC-061, manufactured by Kusumoto Chemical Co., Ltd.) to 100 parts by mass of a hybrid product of polyimide resin and epoxy resin (Imitron #300IX-3, manufactured by Nakata Coating Co., Ltd.) (Resin B), stirring and degassing at room temperature. The obtained conductive composition was coated onto a substrate (product name "Kapton 200H", thickness 200 gauge (50 μm), polyimide film, manufactured by Toray DuPont Co., Ltd.) with an applicator and drying at 250°C for 30 minutes to form a conductive layer with a thickness of 10 μm on the polyimide film, thereby obtaining a substrate having a conductive layer. The bonded body of Example 8 was obtained in the same manner as in Example 1, except that the above-mentioned substrate having a conductive layer was used.

[0173] [Example 9] (Preparation of a substrate having a conductive layer) 100 parts by mass of a ternary copolymer resin of vinyl chloride-vinyl acetate-vinyl alcohol (Solvine A, manufactured by Nisshin Chemical Industry Co., Ltd.) (Resin C) diluted with a solvent was mixed with 20 parts by mass of carbon nanotubes (Lamfil SPC-061, manufactured by Kusumoto Chemical Co., Ltd.), and the mixture was stirred and degassed at room temperature to obtain a conductive composition. The obtained conductive composition was coated onto a substrate (product name "Lumirror S10", thickness 50 μm, PET film, manufactured by Toray Industries, Inc.) using an applicator, and dried at 150°C for 3 minutes to form a conductive layer with a thickness of 10 μm on the PET film, thereby obtaining a substrate having a conductive layer. The bonded body of Example 9 was obtained in the same manner as in Example 1, except that the above-mentioned substrate having a conductive layer was used.

[0174] [Example 10] (Preparation of a substrate having a conductive layer) 100 parts by mass of polyvinyl butyral resin (S-Rec KS-10, manufactured by Sekisui Chemical Co., Ltd.) (Resin D), diluted with a solvent, was mixed with 20 parts by mass of carbon nanotubes (Lamfil SPC-061, manufactured by Kusumoto Kasei Co., Ltd.), and stirred and degassed at room temperature to obtain a conductive composition. The obtained conductive composition was coated onto a substrate (product name "Lumirror S10", thickness 50 μm, PET film, manufactured by Toray Industries, Inc.) using an applicator, and dried at 150°C for 3 minutes to form a conductive layer with a thickness of 10 μm on the PET film, thereby obtaining a substrate having a conductive layer. The bonded body of Example 10 was obtained in the same manner as in Example 1, except that the above-mentioned substrate having a conductive layer was used.

[0175] [Example 11] In the preparation of a substrate having a conductive layer, the conductive layer bond of Example 11 was obtained in the same manner as in Example 10, except that the amount of conductive material was 50 parts by mass.

[0176] [Example 12] (Preparation of a substrate having a conductive layer) 100 parts by mass of acrylic resin (Dianal BR-83, manufactured by Mitsubishi Chemical Corporation) (Resin E) diluted with a solvent was mixed with 20 parts by mass of carbon nanotubes (Lamfil SPC-061, manufactured by Kusumoto Kasei Co., Ltd.), and the mixture was stirred and degassed at room temperature to obtain a conductive composition. The obtained conductive composition was coated onto a substrate (product name "Lumirror S10", thickness 50 μm, PET film, manufactured by Toray Industries, Inc.) using an applicator, and dried at 150°C for 3 minutes to form a conductive layer with a thickness of 10 μm on the PET film, thereby obtaining a substrate having a conductive layer. The bonded body of Example 12 was obtained in the same manner as in Example 1, except that the above-mentioned substrate having a conductive layer was used.

[0177] [Example 13] (Preparation of a substrate having a conductive layer) 100 parts by mass of polyester resin (TP-220, manufactured by Mitsubishi Chemical Corporation) (resin F) diluted with a solvent was mixed with 20 parts by mass of carbon nanotubes (Lamfil SPC-061, manufactured by Kusumoto Kasei Co., Ltd.), and the mixture was stirred and degassed at room temperature to obtain a conductive composition. The obtained conductive composition was coated onto a substrate (product name "Lumirror S10", thickness 50 μm, PET film, manufactured by Toray Industries, Inc.) using an applicator, and dried at 150°C for 3 minutes to form a conductive layer with a thickness of 10 μm on the PET film, thereby obtaining a substrate having a conductive layer. The bonded body of Example 13 was obtained in the same manner as in Example 1, except that the above-mentioned substrate having a conductive layer was used.

[0178] [Example 14] (Preparation of a substrate having a conductive layer) 100 parts by mass of a mixture (represented as resin G in the table) consisting of 20 parts by mass of epoxy resin (JER-828, manufactured by Mitsubishi Chemical Corporation), 30 parts by mass of epoxy resin (JER-1256B40, manufactured by Mitsubishi Chemical Corporation), 50 parts by mass of epoxy resin (JER-630, manufactured by Mitsubishi Chemical Corporation), 5 parts by mass of dicyandiamide (curing agent, DICY, manufactured by Tokyo Chemical Industry Co., Ltd.), and 5 parts by mass of 3-(3,4-dichlorophenyl)1,1-dimethylurea (curing agent, DCMU, manufactured by Tokyo Chemical Industry Co., Ltd.) was mixed with 20 parts by mass of carbon nanotube (Lamfil SPC-061, manufactured by Kusumoto Chemical Co., Ltd.), and stirred and degassed at room temperature to obtain a conductive composition. The obtained conductive composition was coated onto a substrate (product name "Lumirror S10", thickness 50 μm, PET film, manufactured by Toray Industries, Inc.) using an applicator, and dried at 150°C for 30 minutes to form a conductive layer with a thickness of 10 μm on the PET film, thereby obtaining a substrate having a conductive layer. The bonded body of Example 14 was obtained in the same manner as in Example 1, except that the above-mentioned substrate having a conductive layer was used.

[0179] [Example 15] (Preparation of a substrate having a conductive layer) 100 parts by mass of acrylic resin (Acrydic AU-7007, manufactured by DIC Corporation) (resin H) diluted with a solvent was mixed with 20 parts by mass of carbon nanotubes (Lamfil SPC-061, manufactured by Kusumoto Chemical Co., Ltd.), and the mixture was stirred and degassed at room temperature to obtain a conductive composition. The obtained conductive composition was coated onto a substrate (product name "Lumirror S10", thickness 50 μm, PET film, manufactured by Toray Industries, Inc.) using an applicator, and dried at 150°C for 3 minutes to form a conductive layer with a thickness of 10 μm on the PET film, thereby obtaining a substrate having a conductive layer. The bonded body of Example 15 was obtained in the same manner as in Example 1, except that the above-described substrate having a conductive layer was used.

[0180] [Example 16] (Preparation of a substrate having a conductive layer) 100 parts by mass of a mixture (represented as Resin I in the table) consisting of 20 parts by mass of epoxy resin (JER-828, manufactured by Mitsubishi Chemical Corporation), 20 parts by mass of epoxy resin (JER-1256B40, manufactured by Mitsubishi Chemical Corporation), 60 parts by mass of epoxy resin (JER-630, manufactured by Mitsubishi Chemical Corporation), 6 parts by mass of dicyandiamide (curing agent, DICY, manufactured by Tokyo Chemical Industries, Ltd.), and 5 parts by mass of 3-(3,4-dichlorophenyl)1,1-dimethylurea (curing agent, DCMU, manufactured by Tokyo Chemical Industries, Ltd.) was mixed with 20 parts by mass of carbon nanotube (Lamfil SPC-061, manufactured by Kusumoto Chemicals, Ltd.), and stirred and degassed at room temperature to obtain a conductive composition. The obtained conductive composition was coated onto a substrate (product name "Lumirror S10", thickness 50 μm, PET film, manufactured by Toray Industries, Inc.) using an applicator, and dried at 150°C for 30 minutes to form a conductive layer with a thickness of 10 μm on the PET film, thereby obtaining a substrate having a conductive layer. The bonded body of Example 16 was obtained in the same manner as in Example 1, except that the above-mentioned substrate having a conductive layer was used.

[0181] [Comparative Example 1] (Preparation of a substrate having a conductive layer) 100 parts by mass of a mixture (represented as resin J in the table) of 100 parts by mass of polyester urethane resin (UR-3210, manufactured by Toyobo MC Co., Ltd.), 7 parts by mass of blocked isocyanate (BI-7960, manufactured by Baksenden Co., Ltd.), and 3 parts by mass of catalyst (KS-1260, manufactured by Kyodo Pharmaceutical Co., Ltd.) was added to 180 parts by mass of carbon black (Denka Black, manufactured by Denka Co., Ltd.) and 400 parts by mass of isophorone as a solvent. The mixture was stirred and degassed at room temperature to obtain a conductive paste. The obtained conductive composition was coated onto a substrate (product name "Lumirror S10", thickness 50 μm, PET film, manufactured by Toray Industries, Inc.) with an applicator and dried at 150°C for 30 minutes to form a conductive layer with a thickness of 10 μm on the PET film, thereby obtaining a substrate having a conductive layer. The bonded body of Comparative Example 1 was obtained in the same manner as in Example 1, except that the above-mentioned substrate having a conductive layer was used.

[0182] [Comparative Example 2] (Preparation of a substrate having a conductive layer) 100 parts by mass of polyvinyl butyral resin (S-Rec BL-S, manufactured by Sekisui Chemical Co., Ltd.) (resin K) diluted with a solvent was mixed with 20 parts by mass of carbon nanotubes (Lamfil SPC-061, manufactured by Kusumoto Kasei Co., Ltd.), and the mixture was stirred and degassed at room temperature to obtain a conductive composition. The obtained conductive composition was coated onto a substrate (product name "Lumirror S10", thickness 50 μm, PET film, manufactured by Toray Industries, Inc.) using an applicator, and dried at 150°C for 3 minutes to form a conductive layer with a thickness of 10 μm on the PET film, thereby obtaining a substrate having a conductive layer. The bonded body of Comparative Example 2 was obtained in the same manner as in Example 1, except that the above-described substrate having a conductive layer was used.

[0183] [Comparative Example 3] (Preparation of a substrate having a conductive layer) A conductive composition was obtained by adding 20 parts by mass of carbon nanotubes (TUBALL BATT NMP, manufactured by Kusumoto Chemical Co., Ltd.) to 100 parts by mass of a mixture of 100 parts by mass of epoxy resin (JER-828, manufactured by Mitsubishi Chemical Corporation) and 10 parts by mass of 1,2-dimethylimidazole (curing agent, manufactured by Tokyo Chemical Industry Co., Ltd.) (represented as resin L in the table). The mixture was stirred and degassed at room temperature. The obtained conductive composition was coated onto a substrate (product name "Lumirror S10", thickness 50 μm, PET film, manufactured by Toray Industries, Inc.) using an applicator and dried at 150°C for 30 minutes to form a conductive layer with a thickness of 10 μm on the PET film, thereby obtaining a substrate having a conductive layer. The bonded body of Comparative Example 3 was obtained in the same manner as in Comparative Example 1, except that the above-mentioned substrate having a conductive layer was used.

[0184] [Comparative Example 4] In the preparation of the adherend having a conductive layer, a bonded body having a conductive layer of Comparative Example 4 was obtained in the same manner as in Comparative Example 1, except that FA-353N (manufactured by Fujikura Chemical Co., Ltd.) (resin component: resin M) was used as the conductive composition.

[0185] (Initial adhesive strength (22°C / 50%RH 72hr)) Examples 1 to 16 and Comparative Examples 1 to 4 were evaluated. The prepared bonded bodies (sample size 25 mm x 100 mm) were left to stand at 22°C and 50%RH for 72 hours, and then the adhesive strength (22°C / 50%RH 72hr) was measured in a 180° peel test (tensile speed: 300 mm / min, peel temperature 22°C, humidity 50%RH) using a peel tester (product name "Variable Angle Peel Tester YSP", manufactured by Asahi Seiko Co., Ltd.). The initial adhesive strength was calculated according to the method for measuring peel adhesive strength 1 described in JIS Z 0237:2009. Specifically, after the start of adhesive strength measurement, the measurement value for the first 25 mm length was ignored, and the average adhesive strength measurement value for the 50 mm length peeled off from the adherend was used as the value of adhesive strength.

[0186] (Electropeel strength (22°C / 50%RH 72hr)) Before peeling, the positive and negative electrodes of a DC current machine were attached to points α and β of the bond consisting of a substrate 3' having a conductive layer as shown in Figure 6 / electropeelable adhesive layer 4' / metal layered film (conductive substrate) 5', respectively. A voltage of 30V was applied for 30 seconds, and the electropeel strength (22°C / 50%RH 72hr) was measured in the same manner as the adhesive strength measurement described above, except for the point where peeling occurred immediately after the application of the voltage was stopped.

[0187] (Evaluation Criteria for Peeling Force Reduction Rate) The peeling force reduction rate was calculated from the initial adhesive strength and electropenetrating strength described above. The calculation formula is as follows: [(Initial Adhesion Strength) - (Electropenetrating Strength)] × 100 / Initial Adhesion Strength = Peeling Force Reduction Rate (%) A: Peeling force reduction rate is 60% or more B: Peeling force reduction rate is 30% or more but less than 60% C: Peeling force reduction rate is less than 30% If the peeling force reduction rate is evaluated as "A" or "B", it can be said that there is no problem in practical use.

[0188] (Tape Reuse Evaluation Criteria) During the electropenetration force measurement, the surface of the adherend after peeling was visually inspected. If a portion of the conductive layer peeled off from the adherend, which has a conductive layer on the electropenetrating adhesive layer, was attached, it was evaluated as "×". If the conductive layer could be peeled off without any attachment, it was evaluated as "○". An evaluation of "○" indicates that there are no problems in practical use.

[0189] (Surface resistance of the conductive layer) The surface resistance of the conductive layer was measured using the adherends with conductive layers used in Examples 1 to 16 and Comparative Examples 1 to 4 as test samples. The surface on the conductive layer side was measured using a resistivity meter (Loresta GP MCP-T160) manufactured by Nitto Seiko Analytech Co., Ltd., in accordance with JIS K 7194:1994, using the four-terminal method, with an ASP probe, an applied voltage of 10V, and an applied time of 10 seconds. The surface resistance was measured in an environment with a temperature of 25°C ± 5°C and a relative humidity of 50 ± 5%.

[0190] (Method for measuring the contact angle of 1-ethylimidazole) The contact angle of 1-ethylimidazole with respect to the conductive layer was measured using the adherends with conductive layers used in Examples 1 to 16 and Comparative Examples 1 to 4 as test samples. The contact angle on the conductive layer side was measured at 1 second and 30 seconds after droplet application using a contact angle meter (product name "DMo-501", control box "DMC-2", control and analysis software "FAMAS (version 5.0.30)") manufactured by Kyowa Interface Science Co., Ltd. The contact angle was measured at a temperature of 25°C ± 5°C and a relative humidity of 50 ± 5%. The amount of 1-ethylimidazole dropped was 2 μL. Images were automatically acquired at 1 second and 30 seconds after the moment of droplet application, as recognized by the control and analysis software "FAMAS (version 5.0.30)", and the contact angle (°) was calculated from these images using the θ / 2 method. The procedure was performed at N3, and the average value of the calculated values ​​was used.

[0191] (Evaluation Criteria for Contact Angle Change Rate) The contact angle change rate was calculated from the contact angle 1 second after droplet placement and the contact angle 30 seconds after droplet placement, as described above. The calculation formula is as follows: [(Contact angle 1 second after droplet placement) - (Contact angle 30 seconds after droplet placement)] × 100 / (Contact angle 1 second after droplet placement) = Contact angle change rate (%)

[0192] (Method for measuring arithmetic mean surface roughness) Surface roughness was measured using the conductive layer-containing substrates used in Examples 1 to 16 and Comparative Examples 1 to 4 as test samples, with a white light interferometer (Zygo, product name "Newview9000") used on the conductive layer side of the substrate. Specifically, interference fringes were generated using a single white LED illumination, and the arithmetic mean surface roughness Ra of the conductive layer surface in a 0.87 mm x 0.87 mm square area was measured by scanning in the Z direction (thickness method).

[0193] (Method for measuring the water contact angle) The water contact angle was measured one second after droplet placement in the same manner as above, except that the droplet was changed to deionized water.

[0194] (Method for measuring the glass transition temperature Tg of resin components after curing) The Tg of the resin components after curing was measured by weighing approximately 1-2 mg of the cured resin components into an aluminum open cell and using a temperature-modulated DSC (product name "Q-2000", manufactured by TA Instruments Co., Ltd.) under a nitrogen atmosphere of 50 ml / min and a heating rate of 10°C / min. The reversing heat flow (specific heat component) behavior of the resin components was obtained. Referring to JIS K 7121, the temperature at the point where a line equidistant in the vertical axis direction from the line extending from the low-temperature baseline and high-temperature baseline of the obtained reversing heat flow intersects with the curve of the step-like change portion of the glass transition was defined as the glass transition temperature (Tg) of the resin components after curing. In addition, if a catalog value was available, the catalog value was used.

[0195] Tables 1 to 3 show the above examples, comparative examples, and measurement results.

[0196]

[0197]

[0198]

[0199] In the bonded bodies having a conductive layer made of the conductive compositions of Examples 1 to 16, it was found that the initial adhesive strength was high, and that the adhesive strength of the electropenetrating adhesive layer could be sufficiently reduced when a voltage was applied with the conductive layer as the cathode. Furthermore, it was found that cohesive failure of the conductive layer did not occur, and the electropenetrating adhesive layer (electropenetrating adhesive sheet) could be reused. On the other hand, in Comparative Examples 1 to 4, when a voltage was applied with the conductive layer as the cathode, cohesive failure sometimes occurred in a part of the conductive layer. Also, when attempting to electropenetrate, the adhesive strength of the electropenetrating adhesive layer could not be sufficiently reduced. In other words, it was found that the conductive layers of Comparative Examples 1 to 4 did not perform the desired function on the cathode side.

[0200] For example, in a bond having a substrate with a conductive layer made of the conductive composition of Example 5, the contact angle 16° to 35° 1 second after the application of 1-ethylimidazole is shown to be high initial adhesion, and the adhesion of the electropenetrating adhesive layer can be sufficiently reduced when a voltage is applied with the conductive layer as the cathode. 1-ethylimidazole is an analogue of the 1-ethyl-3-methylimidazolium cation reduction. In contrast, the cation reduction generated by applying voltage to the electropenetrating adhesive layer in Example 5 is a pyrrolidinium-based cation reduction. From the above examples, it can be said that even if the cation reduction generated in the electropenetrating adhesive layer is different, a suitable conductive composition with suppressed penetration of the cation reduction can be selected by using the contact angle 1 second after the application of 1-ethylimidazole.

[0201] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0202] The present invention provides a conductive composition that can form a conductive layer with high adhesive strength, and when a bond is formed by adhering an electropenetrating adhesive sheet to an adherend having the conductive layer, the adhesive strength of the electropenetrating adhesive layer on the electropenetrating adhesive sheet is sufficiently reduced by the application of voltage; a conductive layer formed by the conductive composition; an adherend having the conductive layer; a bond having the adherend having the conductive layer; and a method for separating the bond having the adherend having the conductive layer.

[0203] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2024-166686 filed on 25 September 2024, the contents of which are incorporated herein by reference.

[0204] 1 Conductive layer 2 Substrate 3, 3' Adhesion 4, 4' Electropeelable adhesive layer 5, 5' Conductive substrate 6 Other adhesive layer 7 Conductive substrate 8 Substrate 9 Other conductive layers X1-X4 Conductive substrate Y1-Y4 Bonded structure

Claims

1. A conductive composition comprising a resin component, wherein the contact angle of 1-ethylimidazole to the conductive layer formed by the conductive composition one second after droplet placement is 16° or more and 35° or less.

2. The conductive composition according to claim 1, wherein the surface resistance of the conductive layer is 8000 Ω / □ or less.

3. The conductive composition according to claim 1, wherein the surface resistance of the conductive layer is 3000 Ω / □ or less.

4. The conductive composition according to claim 1, wherein the arithmetic mean surface roughness Ra of the conductive layer is 0.65 μm or less.

5. The conductive composition according to claim 1, wherein the contact angle of water on the conductive layer one second after droplet placement is 110° or less.

6. The conductive composition according to claim 1, wherein the glass transition temperature Tg of the resin component after curing is higher than 50°C.

7. A conductive composition according to any one of claims 1 to 6, for forming a conductive layer to be attached to an electropenetrating adhesive layer containing an ionic substance.

8. A conductive layer formed by the conductive composition according to any one of claims 1 to 6.

9. A conductive layer formed by a conductive composition containing a resin component, wherein the contact angle of 1-ethylimidazole to the conductive layer one second after droplet placement is 16° or more and 35° or less.

10. The conductive layer according to claim 9, wherein the surface resistance of the conductive layer is 8000 Ω / □ or less.

11. The conductive layer according to claim 9, wherein the surface resistance of the conductive layer is 3000 Ω / □ or less.

12. The conductive layer according to claim 9, wherein the arithmetic mean surface roughness Ra of the conductive layer is 0.65 μm or less.

13. The conductive layer according to claim 9, wherein the contact angle of water droplets onto the conductive layer one second after application is 110° or less.

14. The conductive layer according to claim 9, wherein the glass transition temperature Tg of the resin component after curing is higher than 50°C.

15. A conductive layer according to any one of claims 9 to 14, which is attached to an electropenetrating adhesive layer containing an ionic substance.

16. A substrate having a conductive layer formed by the conductive composition according to any one of claims 1 to 6, or a conductive layer according to any one of claims 9 to 14.

17. A bond comprising a workpiece having a conductive layer, an adhesive layer, and a conductive substrate, laminated in that order, wherein the adhesive layer is attached to the conductive layer side of the workpiece, and the conductive layer is formed of a conductive composition according to any one of claims 1 to 6, or is a conductive layer according to any one of claims 9 to 14.

18. The bonded body according to claim 17, wherein the adhesive layer is an electro-peelable adhesive layer containing an ionic substance.

19. The joint according to claim 18, wherein the ionic substance is an ionic liquid.

20. The bonded body according to claim 17, wherein the adhesive layer is a pressure-sensitive adhesive layer.

21. A method for separating a bonded body comprising an electropenetrating adhesive sheet comprising a conductive substrate and an electropenetrating adhesive layer containing an ionic substance, and an adherend described in claim 16, the method comprising applying a voltage to the electropenetrating adhesive layer to separate the electropenetrating adhesive sheet and the adherend.

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