Method for peeling off the bonded body

Abstract

To provide an electrically peelable adhesive sheet capable of suppressing contamination of air bubbles when being adhered to an adherend, facilitating avoiding irregularities on a surface, and facilitating peeling an obtained joined object.SOLUTION: An electrically peelable adhesive sheet in a first embodiment of the present invention comprises: a conducting base material having conductivity at least on one surface; a first adhesive layer comprising an electrically peelable adhesive and formed on the surface having the conductivity of the conducting base material; and a second adhesive layer formed on a surface opposite to the first adhesive layer of the conducting base material. The electrically peelable adhesive sheet also comprises: a plurality of parts to be connected, and a connection part for connecting the plurality of parts to be connected.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrically peelable pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer formed from an electrically peelable pressure-sensitive adhesive composition, a bonded structure of the pressure-sensitive adhesive sheet and an adherend, and a method for peeling off the bonded structure. [Background technology]

[0002] In electronic component manufacturing processes, etc., there is an increasing demand for rework to improve yields and recycling, such as disassembling and recovering components after use. To meet these demands, double-sided PSA sheets that have a certain level of adhesive strength and releasability are sometimes used to join components in electronic component manufacturing processes, etc.

[0003] As a double-sided pressure-sensitive adhesive sheet that achieves both adhesive strength and releasability, a pressure-sensitive adhesive sheet (electrically peelable pressure-sensitive adhesive sheet) having an electrically peelable pressure-sensitive adhesive layer made of an electrically peelable pressure-sensitive adhesive composition that peels off when a voltage is applied to the adhesive layer is known (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 064925 Summary of the Invention [Problem to be solved by the invention]

[0005] When the size of the adherends to be bonded is large, it is conceivable to use a pressure-sensitive adhesive sheet with a larger area to match the size of the adherends, but in this case, the following problems arise. That is, first, increasing the area of the adhesive sheet makes it easier for air bubbles to become trapped between the adherend and the adhesive sheet, but if air bubbles become trapped, the contact area between the adhesive sheet and the adherend will decrease, thereby reducing the adhesive strength between the adherend and the adhesive sheet, which is undesirable. Furthermore, when the adherend is, for example, an electronic substrate, its surface may have unevenness due to various elements, etc., and it is necessary to avoid such unevenness when adhering the adhesive sheet to the adherend, but when the adhesive sheet has a large area, it is difficult to avoid the unevenness.

[0006] To solve the above problems, it is conceivable to use multiple adhesive sheets to bond the adherends. This can avoid the inclusion of air bubbles due to the large area of the adhesive sheets, and also allows each adhesive sheet to be arranged so as to avoid surface irregularities. However, in this case, voltage must be applied to the electrically releasable adhesive layer of each adhesive sheet when peeling, which increases the number of steps and reduces workability.

[0007] Therefore, when joining adherends using electrically peelable pressure-sensitive adhesive sheets, it is necessary to simultaneously suppress the inclusion of air bubbles, easily avoid surface irregularities, and prevent a decrease in workability due to increased labor required for peeling. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have found that the above-mentioned object can be achieved by an electrically peelable pressure-sensitive adhesive sheet and bonded body having a specific configuration, and that the above-mentioned object can also be achieved by a specific peeling method.

[0009] That is, the electrically peelable adhesive sheet according to the first embodiment of the present invention is an electrically peelable adhesive sheet comprising an electrically conductive substrate having at least one surface that is conductive, a first adhesive layer made of an electrically peelable adhesive formed on the conductive surface of the electrically conductive substrate, and a second adhesive layer formed on the surface of the electrically conductive substrate opposite the first adhesive layer, and is also provided with a plurality of connectable portions and connecting portions that connect the plurality of connectable portions together.

[0010] In one aspect of the first embodiment of the present invention, the electrically peelable pressure-sensitive adhesive sheet may be comb-shaped.

[0011] Furthermore, the bonded structure according to the first embodiment of the present invention is a bonded structure comprising an electrically peelable pressure-sensitive adhesive sheet according to the first embodiment of the present invention, a first adherend adhered to the first pressure-sensitive adhesive layer, and a second adherend adhered to the second pressure-sensitive adhesive layer, wherein the first adherend is electrically conductive.

[0012] Furthermore, a bonded structure according to a second embodiment of the present invention is a bonded structure in which a first adherend and a second adherend are bonded together using a plurality of electrically peeling adhesive sheets, the electrically peeling adhesive sheets comprising a conductive substrate, a first adhesive layer made of an electrically peeling adhesive formed on one side of the conductive substrate, and a second adhesive layer formed on the side of the conductive substrate opposite the first adhesive layer, the first adherend being conductive and adhered to the first adhesive layer, and the second adherend being adhered to the second adhesive layer, and the conductive substrates of the plurality of electrically peeling adhesive sheets being electrically connected to each other by a connecting member.

[0013] Furthermore, a bonded structure according to a third embodiment of the present invention is a bonded structure in which a first adherend and a second adherend are bonded together using a plurality of electrically peelable adhesive sheets, the electrically peelable adhesive sheets being made of an electrically peelable adhesive, the first adherend being attached to one side of the electrically peelable adhesive sheet, and the second adherend being attached to the side of the electrically peelable adhesive sheet opposite the first adherend, and the first adherend and the second adherend being electrically conductive.

[0014] Furthermore, a bonded structure according to a fourth embodiment of the present invention is a bonded structure in which a first adherend and a second adherend are bonded together using a plurality of electrically peeling adhesive sheets, the electrically peeling adhesive sheets comprising a conductive substrate, a first adhesive layer made of an electrically peeling adhesive formed on the conductive substrate, and a second adhesive layer made of a conductive adhesive formed on the surface of the conductive substrate opposite the first adhesive layer, the first adhesive layers of the plurality of electrically peeling adhesive sheets each being attached to the first adherend, and the second adhesive layers each being attached to the second adherend, the first adherend being electrically conductive, the second adherend having a conductive portion having conductivity, and the second adhesive layers of the plurality of electrically peeling adhesive sheets each being electrically connected by the conductive portion.

[0015] Furthermore, a fifth embodiment of the present invention relates to a method for peeling a bonded structure in which a first adherend and a second adherend are bonded together using a plurality of electrically peeling adhesive sheets, wherein the electrically peeling adhesive sheets comprise an electrically conductive substrate having at least one conductive surface, a first adhesive layer made of an electrically peeling adhesive formed on the conductive surface of the electrically peeling substrate, and a second adhesive layer formed on the surface of the electrically peeling substrate opposite the first adhesive layer, the first adherend being conductive and attached to the first adhesive layer, and the second adherend being attached to the second adhesive layer, and the electrically peeling adhesive substrates of the plurality of electrically peeling adhesive sheets are electrically connected by a jig, and the first adherend and the second adherend are peeled off while simultaneously applying a voltage to the first adhesive layer of each of the plurality of electrically peeling adhesive sheets. [Effects of the Invention]

[0016] The electrically peelable pressure-sensitive adhesive sheet according to the first embodiment of the present invention can prevent air bubbles from being mixed in when the sheet is attached to an adherend, and can easily avoid surface irregularities. The bonded structure according to the first embodiment of the present invention is excellent in workability during peeling. The bonded structures according to the second to fourth embodiments of the present invention are bonded structures in which adherends are bonded with a plurality of electrically peelable pressure-sensitive adhesive sheets, and are excellent in workability when peeling them off. According to the method for peeling off a bonded body according to the fifth embodiment of the present invention, a bonded body in which adherends are bonded by a plurality of electrically peelable pressure-sensitive adhesive sheets can be peeled off with good workability. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view of an electrically peelable pressure-sensitive adhesive sheet according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating a bonded body according to the first embodiment of the present invention, where (a) is a side view and (b) is a perspective view. [Figure 3] FIG. 3 is an exploded perspective view of a bonded body according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a diagram illustrating a bonded body according to a second embodiment of the present invention, where (a) is a side view and (b) is a perspective view. [Figure 5] FIG. 5 is an exploded perspective view of a bonded body according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a diagram illustrating a bonded body according to a third embodiment of the present invention, where (a) is a side view and (b) is a perspective view. [Figure 7] FIG. 7 is an exploded perspective view of a bonded body according to a third embodiment of the present invention. [Figure 8] FIG. 8 is a diagram illustrating a bonded body according to a fourth embodiment of the present invention, where (a) is a side view and (b) is a perspective view. [Figure 9] FIG. 9 is an exploded perspective view of a bonded body according to a fourth embodiment of the present invention. [Figure 10] FIG. 10 is a diagram illustrating a method for peeling a bonded body according to a fifth embodiment of the present invention, where (a) is a side view and (b) is a top view. [Figure 11] FIG. 11 is a perspective view illustrating a method for peeling a bonded body according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes in detail the preferred embodiments of the present invention, but the present invention is not limited to the following preferred embodiments.

[0019] [First embodiment] <Adhesive sheet> 1 is a schematic diagram of an electrically peelable adhesive sheet 110 according to a first embodiment of the present invention (hereinafter simply referred to as "adhesive sheet 110 of this embodiment" or "adhesive sheet 110"). The adhesive sheet 110 of this embodiment is an electrically peelable adhesive sheet comprising an electrically conductive substrate 112 having at least one conductive surface, a first adhesive layer 111 made of an electrically peelable adhesive formed on the conductive surface of the electrically conductive substrate 112, and a second adhesive layer 113 formed on the surface of the electrically conductive substrate 112 opposite to the first adhesive layer 111, and comprises a plurality of connectable portions 110a and connecting portions 110b that connect the plurality of connectable portions 110a together.

[0020] (Components of adhesive sheet) First, the layers forming adhesive sheet 110 of this embodiment, the connected portions, and the connecting portions will be described.

[0021] The first adhesive layer 111 is an adhesive layer made of an electrically peelable adhesive, and contains a polymer as an adhesive and an electrolyte.

[0022] Examples of the polymer contained in first adhesive layer 111 include acrylic polymers, rubber polymers, vinyl alkyl ether polymers, silicone polymers, polyester polymers, polyamide polymers, urethane polymers, fluorine polymers, and epoxy polymers. First adhesive layer 111 may contain only one type of polymer, or may contain two or more types of polymers. From the viewpoint of cost reduction and realization of high productivity, it is preferable to contain an acrylic polymer. An acrylic polymer is a polymer containing monomer units derived from an alkyl acrylate ester and / or an alkyl methacrylate ester as the main monomer units that are the most abundant in terms of mass ratio. Hereinafter, "(meth)acrylic" represents "acrylic" and / or "methacrylic".

[0023] When first pressure-sensitive adhesive layer 111 contains an acrylic polymer, the acrylic polymer preferably contains a monomer unit derived from a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 14 carbon atoms. Examples of the (meth)acrylic acid alkyl ester 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, 2-ethylbutyl (meth)acrylate, 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, and n-tetradecyl (meth)acrylate. Among these, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, and isononyl (meth)acrylate are preferred. One type of (meth)acrylic acid alkyl ester may be used, or two or more types of (meth)acrylic acid alkyl esters may be used.

[0024] The proportion of monomer units derived from a (meth)acrylic acid alkyl ester having an alkyl group with 1 to 14 carbon atoms in the acrylic polymer is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, and more preferably 80% by mass or more, from the viewpoint of realizing high adhesive strength for the first pressure-sensitive adhesive layer 111. That is, the proportion of a (meth)acrylic acid alkyl ester having an alkyl group with 1 to 14 carbon atoms in the total amount of raw material monomers for forming the acrylic polymer is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, and more preferably 80% by mass or more, from the viewpoint of realizing high adhesive strength for the first pressure-sensitive adhesive layer 111.

[0025] When first pressure-sensitive adhesive layer 111 contains an acrylic polymer, the acrylic polymer preferably contains a monomer unit derived from a polar group-containing monomer, from the viewpoint of realizing high adhesive strength for first pressure-sensitive adhesive layer 111. Examples of polar group-containing monomers include carboxyl group-containing monomers, hydroxyl group-containing monomers, and vinyl group-containing monomers.

[0026] Examples of carboxyl group-containing monomers include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, carboxyethyl (meth)acrylate, and carboxypentyl (meth)acrylate. Among these, acrylic acid and methacrylic acid are preferred. One type of carboxyl group-containing monomer may be used, or two or more types of carboxyl group-containing monomers may be used.

[0027] 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 acrylate, N-methylol (meth)acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether. Among these, 2-hydroxyethyl (meth)acrylate is preferred. Furthermore, one type of hydroxyl group-containing monomer may be used, or two or more types of hydroxyl group-containing monomers may be used.

[0028] Examples of vinyl group-containing monomers include vinyl acetate, vinyl propionate, and vinyl laurate. Of these, vinyl acetate is preferred. One type of vinyl group-containing monomer may be used, or two or more types of vinyl group-containing monomers may be used.

[0029] The proportion of the monomer unit derived from the polar group-containing monomer in the acrylic polymer is preferably 0.1% by mass or more, from the viewpoint of ensuring cohesive strength in the first pressure-sensitive adhesive layer 111 and preventing adhesive residue on the adherend surface after peeling off the first pressure-sensitive adhesive layer 111. That is, the proportion of the polar group-containing monomer in the total amount of raw material monomers for forming the acrylic polymer is preferably 0.1% by mass or more, from the viewpoint of ensuring cohesive strength and preventing adhesive residue. Furthermore, the proportion of the monomer unit derived from the polar group-containing monomer in the acrylic polymer is preferably 30% by mass or less, from the viewpoint of appropriately expressing the properties attributable to the monomer unit derived from the (meth)acrylic acid alkyl ester having an alkyl group having 1 to 14 carbon atoms in the acrylic polymer. That is, the proportion of the polar group-containing monomer in the total amount of raw material monomers for forming the acrylic polymer is preferably 30% by mass or less, from the viewpoint of expressing the properties.

[0030] The method for polymerizing the above-mentioned monomers to obtain an acrylic polymer is not particularly limited, and known methods can be used. Examples of polymerization techniques include solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization.

[0031] From the viewpoint of realizing sufficient adhesive strength in the first adhesive layer 111, the polymer content in the first adhesive layer 111 is preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 85% by mass or more, and more preferably 90% by mass or more.

[0032] The electrolyte contained in first pressure-sensitive adhesive layer 111 is a substance that can be ionized into anions and cations, and examples of such electrolytes include ionic liquids, alkali metal salts, and alkaline earth metal salts. From the viewpoint of realizing good electrical peeling properties in first pressure-sensitive adhesive layer 111, ionic liquids are preferred as the electrolyte contained in first pressure-sensitive adhesive layer 111. Ionic liquids are salts that are liquid at room temperature (approximately 25°C) and contain anions and cations.

[0033] When the first adhesive layer 111 contains an ionic liquid, the anion of the ionic liquid is (FSO2)2N - , (CF3SO2)2N - , (CF3CF2SO2)2N - , (CF3SO2)3C - , Br - , AlCl4 - , Al2Cl7 - , NO3 - , BF4 - , PF6 - , CH3COO - , CF3COO - , CF3CF2CF2COO - , CF3SO3 - , CF3(CF2)3SO3 - , AsF6 - , SbF6 - and F(HF) n - It is preferable that the anion contains at least one selected from the group consisting of (FSO2)2N - [Bis(fluorosulfonyl)imide anion], and (CF3SO2)2N - [Bis(trifluoromethanesulfonyl)imide anion] is preferable because it is chemically stable and is suitable for realizing electrical peelability of first pressure-sensitive adhesive layer 111.

[0034] When the first adhesive layer 111 contains an ionic liquid, it is preferable that the cation of the ionic liquid contains at least one selected from the group consisting of imidazolium-based cations, pyridinium-based cations, pyrrolidinium-based cations, and ammonium-based cations.

[0035] Examples of imidazolium 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. cation, 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.

[0036] 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.

[0037] Examples of pyrrolidinium-based cations include 1-ethyl-1-methylpyrrolidinium cation and 1-butyl-1-methylpyrrolidinium cation.

[0038] Examples of ammonium-based cations include tetraethylammonium cation, tetrabutylammonium cation, methyltrioctylammonium cation, tetradecyltrihexylammonium cation, glycidyltrimethylammonium cation, and trimethylaminoethylacrylate cation.

[0039] As the ionic liquid in first pressure-sensitive adhesive layer 111, an ionic liquid containing the above-mentioned (FSO2)2N-[bis(fluorosulfonyl)imide anion] and a cation having a molecular weight of 160 or less is particularly preferred, from the viewpoint of utilizing the high diffusibility of cations to realize high electrical peelability in first pressure-sensitive adhesive layer 111. Examples of cations having 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.

[0040] Commercially available ionic liquids contained in the first adhesive layer 111 include, for example, "ELEXCEL AS-110," "ELEXCEL MP-442," "ELEXCEL IL-210," "ELEXCEL MP-471," "ELEXCEL MP-456," and "ELEXCEL AS-804," manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.

[0041] Examples of alkali metal salts include LiCl, Li2SO4, LiBF4, LiPF6, LiClO4, LiAsF6, LiCF3SO3, LiN(SO2CF3)2, LiN(SO2C2F5)2, LiC(SO2CF3)3, NaCl, Na2SO4, NaBF4, NaPF6, NaClO4, NaAsF6, NaCF3SO3, NaN(SO2CF3)2, NaN(SO2C2F5)2, NaC(SO2CF3)3, KCl, K2SO4, KBF4, KPF6, KClO4, KAsF6, KCF3SO3, KN(SO2CF3)2, KN(SO2C2F5)2 and KC(SO2CF3)3.

[0042] The content of the ionic liquid in the first pressure-sensitive adhesive layer 111 is, for example, 0.1 parts by mass or more relative to 100 parts by mass of the polymer in the first pressure-sensitive adhesive layer 111 in order to impart electrical releasability to the first pressure-sensitive adhesive layer 111, and from the viewpoint of realizing better electrical releasability, it is preferably 0.5 parts by mass or more, more preferably 0.6 parts by mass or more, even more preferably 0.8 parts by mass or more, particularly preferably 1.0 parts by mass or more, and most preferably 1.5 parts by mass or more. From the viewpoint of realizing a good balance between good adhesive strength and electrical releasability for the first pressure-sensitive adhesive layer 111, the content of the ionic liquid in the first pressure-sensitive adhesive layer 111 is preferably 30 parts by mass or less, 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 relative to 100 parts by mass of the polymer in the first pressure-sensitive adhesive layer 111.

[0043] The first adhesive layer 111 may contain other components as long as the effects of the present invention are not impaired. Examples of such components include tackifiers, silane coupling agents, colorants, pigments, dyes, surface lubricants, leveling agents, softeners, antioxidants, antiaging agents, light stabilizers, polymerization inhibitors, inorganic or organic fillers, metal powders, particulate materials, and foil-like materials. The content of these components is determined depending on the intended use, within a range that does not impair the effects of the present invention. For example, the content is 10 parts by mass or less per 100 parts by mass of the polymer.

[0044] The thickness of first pressure-sensitive adhesive layer 111 is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more, and particularly preferably 8 μm or more from the viewpoint of realizing good adhesiveness in first pressure-sensitive adhesive layer 111. Furthermore, from the viewpoint of reducing the voltage applied when peeling off the adherend, the thickness is preferably 1000 μm or less, more preferably 500 μm or less, even more preferably 100 μm or less, and particularly preferably 30 μm or less.

[0045] Second adhesive layer 113 contains a polymer for imparting adhesiveness to second adhesive layer 113. The components contained in second adhesive layer 113 and their contents are the same as those described above for the components contained in first adhesive layer 111, except for the electrolyte. The thickness of second adhesive layer 113 is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more, and particularly preferably 8 μm or more, from the viewpoint of realizing good adhesiveness in second adhesive layer 113. Also, it is preferably 1000 μm or less, more preferably 500 μm or less, and even more preferably 100 μm or less.

[0046] There are no particular limitations on the conductive substrate 112 as long as it has conductivity on at least one surface. For example, as shown in Fig. 1, it may have a laminated structure including a conductive layer 112a and a substrate layer 112b, or it may have a single layer structure made of metal foil or the like.

[0047] The thickness of the conductive substrate 112 is not particularly limited, but is preferably 10 μm or more, more preferably 12 μm or more, and even more preferably 25 μm or more. Also, it is preferably 1000 μm or less, more preferably 500 μm or less, even more preferably 300 μm or less, and particularly preferably 100 μm or less.

[0048] When the conductive substrate 112 has a laminated structure including a conductive layer 112a and a substrate layer 112b, the substrate layer 112b functions as a support, and examples thereof include a plastic substrate, a fiber substrate, a paper substrate, and a laminate thereof. The substrate layer 112b may be a single layer or multiple layers. Furthermore, the substrate layer 112b may be subjected to various treatments, such as a back surface treatment, an antistatic treatment, and a primer treatment, as necessary.

[0049] The thickness of the base layer 112b is not particularly limited, but is preferably 10 μm or more, more preferably 12 μm or more, and even more preferably 25 μm or more, and is preferably 1000 μm or less, more preferably 500 μm or less, even more preferably 300 μm or less, and particularly preferably 100 μm or less.

[0050] The conductive layer 112a is a layer having electrical conductivity and is made of, for example, a metal or a conductive polymer, and can be formed by plating, chemical vapor deposition, sputtering, or the like.

[0051] The thickness of the conductive layer 112a is not particularly limited, but is preferably 0.001 μm or more, more preferably 0.01 μm or more, even more preferably 0.03 μm or more, and particularly preferably 0.05 μm or more. The thickness is also preferably 1000 μm or less, more preferably 500 μm or less, even more preferably 300 μm or less, particularly preferably 50 μm or less, and most preferably 10 μm or less.

[0052] The adhesive sheet 110 of this embodiment includes a plurality of connection receiving portions 110a. The size and shape of the connection receiving portions 110a are not particularly limited, and may be different or the same for each connection receiving portion 110a. The number of connection receiving portions 110a is also not particularly limited. Furthermore, the plurality of connectable portions 110a are connected by connecting portions 110b. The size and shape of the connecting portions 110b are not particularly limited, and they may be different for each connecting portion 110b or the same for each connecting portion 110b. The number of connectable portions 110a is also not particularly limited. In the adhesive sheet 110 of this embodiment, all connectable portions 110a are connected to at least one other connectable portion 110a by connecting portions 110b.

[0053] In the adhesive sheet 110 of this embodiment as described above, the areas of the respective connectable portions 110a and connecting portions 110b are smaller than in a uniform adhesive sheet, which makes it possible to prevent air bubbles from being mixed in when the sheet is applied. Furthermore, because there are gaps between the multiple connectable portions 110a, irregularities on the surface of the adherend can be positioned in the gaps to join the adherends. Furthermore, adhesive sheet 110 of this embodiment has a smaller area than a uniform adhesive sheet, which is also preferable from the viewpoint of cost reduction.

[0054] Separators (release liners) may be provided on the surfaces of the first adhesive layer 111 and the second adhesive layer 113 of the adhesive sheet 110 of this embodiment. The separators are elements for protecting the first adhesive layer 111 and the second adhesive layer 113 of the adhesive sheet 110 so that they do not become exposed, and are peeled off from the adhesive sheet 110 when the adhesive sheet 110 is attached to an adherend. The adhesive sheet 110 may be sandwiched between two separators, or the adhesive sheet 110 may be wound into a roll together with the separators so that the adhesive sheets 110 and the separators are arranged alternately. Examples of separators include a substrate having a release treatment layer, a low-adhesion substrate made of a fluoropolymer, and a low-adhesion substrate made of a non-polar polymer. The surface of the separator may be subjected to a release treatment, an antifouling treatment, or an antistatic treatment. The thickness of the separator is, for example, 5 to 200 μm.

[0055] (Adhesive strength of adhesive sheet) From the viewpoint of realizing good adhesive strength, it is preferable that each adhesive surface of adhesive sheet 110, i.e., the surface on the side of first adhesive layer 111 and the surface on the side of second adhesive layer 113, have a 180° peel adhesive strength (against SUS304 plate, tensile speed 300 mm / min, peel temperature 23°C) of 0.1 N / 10 mm or more. The 180° peel adhesive strength of adhesive sheet 110 can be measured, for example, as follows in accordance with JIS Z 0237. First, one separator was peeled off from an adhesive sheet 110 with separators on both sides, and a 50 μm-thick polyethylene terephthalate (PET) film was attached to the exposed adhesive surface to back the adhesive sheet 110. Next, a test piece (10 mm wide x 100 mm long) was cut out from the backed adhesive sheet 110. Next, the other separator was peeled off from the test piece, and the test piece was attached to a stainless steel plate (SUS304) as an adherend. A 2 kg roller was then moved back and forth once to press the test piece and the adherend together. After leaving the test piece to stand for 30 minutes, the 180° peel adhesive strength (tensile speed: 300 mm / min, peel temperature: 23°C) was measured using a peel tester (product name "YSP Variable Angle Peel Measuring Instrument," manufactured by Asahi Seiko Co., Ltd.).

[0056] (Method of manufacturing pressure-sensitive adhesive sheet) In producing a pressure-sensitive adhesive sheet, for example, first, a pressure-sensitive adhesive composition for forming a first pressure-sensitive adhesive layer (first composition) and a pressure-sensitive adhesive composition for forming a second pressure-sensitive adhesive layer (second composition) are prepared. Next, the first composition is applied to the conductive surface of the current-carrying substrate and dried. This forms the first pressure-sensitive adhesive layer. Next, the second composition is applied to the opposite side of the current-carrying substrate and dried. This forms the second pressure-sensitive adhesive layer. For example, a pressure-sensitive adhesive sheet can be produced in this manner.

[0057] Alternatively, the PSA sheet may be produced by a so-called transfer method. Specifically, first, a first PSA layer and a second PSA layer are each formed on a separator (release liner). The first PSA layer is formed by applying the first composition for forming the first PSA layer to the release-treated surface of a predetermined separator to form a coating film, and then drying the coating film. The second PSA layer is formed by applying the second composition for forming the second PSA layer to the release-treated surface of a predetermined separator to form a coating film, and then drying the coating film. Next, the first PSA layer with the separator is attached to the conductive layer side of the current-carrying substrate. Next, the second PSA layer with the separator is attached to the base layer side of the current-carrying substrate. For example, a PSA sheet can be produced in this manner.

[0058] When manufacturing the adhesive sheet 110, the adhesive sheet 110 may be manufactured by the above method using an electrically conductive substrate 112 having the same shape as the adhesive sheet 110 to be manufactured (hereinafter also referred to as the "desired shape"), or the adhesive sheet 110 may be manufactured by cutting an adhesive sheet (hereinafter also referred to as the "adhesive sheet material") manufactured by the above method using an electrically conductive substrate having a shape different from the desired shape into the desired shape.

[0059] When manufacturing adhesive sheet 110 by cutting adhesive sheet material, it is preferable that adhesive sheet 110 has a shape in which multiple connectable portions 110a extend from a single connecting portion 110b, and it is preferable that adhesive sheet 110 has a shape in which multiple connectable portions 110a extend in the same direction from single connecting portion 110b, that is, a comb shape as shown in Fig. 1. In such a case, by manufacturing adhesive sheet 110 by cutting adhesive sheet material so as to obtain two interlocking comb-shaped adhesive sheets 110, it is possible to reduce the amount of adhesive sheet material that is wasted, and the manufacturing cost of adhesive sheet 110 can be reduced.

[0060] <Jointed body and method for electrical peeling of joined body> (zygote) Next, a bonded body obtained using adhesive sheet 110 of the first embodiment will be described. Fig. 2(a) is a side view of a bonded body 140 according to a first embodiment of the present invention (hereinafter simply referred to as "bonded body 140 of this embodiment" or "bonded body 140"), and Fig. 2(b) is a perspective view of the bonded body 140 of this embodiment. Fig. 3 is an exploded perspective view of the bonded body 140 of this embodiment. The bonded body 140 of this embodiment is a bonded body comprising the adhesive sheet 110 of this embodiment, a first adherend 120 attached to the first adhesive layer 111, and a second adherend 130 attached to the second adhesive layer 113, and the first adherend 120 is conductive.

[0061] The first adherend 120 is not particularly limited as long as it is conductive, and examples of the constituent material of such an adherend include aluminum, copper, iron, silver, and alloys containing these. It may also be a conductive polymer. It is sufficient that the first adherend 120 is conductive at least in the portions necessary to achieve the effects of the present invention. It is sufficient that the first adherend 120 is conductive at least in the portion that contacts the first pressure-sensitive adhesive layer 111 and the portion that contacts the terminal of the voltage application device, and that these portions are electrically conductive. Meanwhile, in this embodiment, the second adherend 130 may or may not be conductive.

[0062] (electrical peeling method) When electrically peeling the bonded body 140 configured as described above, a voltage is applied to the first adhesive layer 111 of the adhesive sheet 110 via the first adherend 120 and the current-carrying substrate 112. In the adhesive sheet 110 that bonds the bonded body 140 of this embodiment, the multiple connectable portions 110a are connected by the connecting portions 110b, so that it is easy to simultaneously apply a voltage to all of the connectable portions 110a and the connecting portions 110b. The method for contacting the terminals with the first adherend 120 and the current-carrying substrate 112 when applying voltage is not particularly limited, but from the standpoint of workability, it is particularly preferable to contact the terminals of the voltage application device with the first adherend 120 and the current-carrying substrate 112 from the same direction.

[0063] For example, when contacting terminals of a voltage application device with the first adherend 120 and the current-carrying substrate 112 from the direction of the first adherend, the pressure-sensitive adhesive sheet 110 may have a portion that protrudes from the first adherend 120 when the bonded structure 140 is observed in a plan view from the direction of the first adherend 120, in order to facilitate contact of the terminals of the voltage application device with the current-carrying substrate 112. This portion may be provided with the first pressure-sensitive adhesive layer 111, or may not be provided with the first pressure-sensitive adhesive layer 111, so that the conductive surface of the current-carrying substrate 112 is exposed. By providing such a portion, it becomes easy to contact the terminals of the voltage application device with the current-carrying substrate 112 from the direction of the first adherend 120. Note that when such a portion is provided with the first pressure-sensitive adhesive layer 111, the terminals are brought into contact with the current-carrying substrate by penetrating the first pressure-sensitive adhesive layer 111. Alternatively, for example, the terminal may be brought into contact with the current-carrying substrate 112 by penetrating the first adherend 120 and the first pressure-sensitive adhesive layer 111 .

[0064] The voltage applied to the first pressure-sensitive adhesive layer 111 during electrical peeling of the bonded structure 140 is preferably 1 V or more, more preferably 3 V or more, and even more preferably 6 V or more. It is also preferably 100 V or less, more preferably 50 V or less, even more preferably 30 V or less, and particularly preferably 15 V or less. A voltage within this range is preferable because it allows the bonded structure to be separated efficiently. For example, within this range, it is possible to use readily available power sources such as dry batteries as the power source for the voltage application device. Furthermore, it is preferable that the time for applying the voltage to the first pressure-sensitive adhesive layer 111 is short, specifically, preferably within 60 seconds, more preferably within 40 seconds, and more preferably within 20 seconds. A time within such a range is suitable for improving the efficiency of the joining body separation operation. These preferable applied voltages and preferable application times also apply to the second to fifth embodiments described later.

[0065] [Second embodiment] Fig. 4(a) is a side view of a bonded body 240 according to a second embodiment of the present invention (hereinafter simply referred to as "bonded body 240 of this embodiment" or "bonded body 240"), and Fig. 4(b) is a perspective view of the bonded body 240 of this embodiment. Fig. 5 is an exploded perspective view of the bonded body 240 of this embodiment. The bonded structure 240 of this embodiment is a bonded structure in which a first adherend 220 and a second adherend 230 are bonded together by a plurality of electrically peeling adhesive sheets 210, and the electrically peeling adhesive sheet 210 comprises a conductive substrate 212, a first adhesive layer 211 made of an electrically peeling adhesive formed on one side of the conductive substrate 212, and a second adhesive layer 213 formed on the side of the conductive substrate 212 opposite to the first adhesive layer 211, the first adherend 220 is conductive and is adhered to the first adhesive layer 211, and the second adherend 230 is adhered to the second adhesive layer 213, and the conductive substrates 212 of the plurality of electrically peeling adhesive sheets 210 are electrically connected to each other by connecting members 214.

[0066] <Adhesive sheet> First, the electrically peelable adhesive sheet 210 (hereinafter simply referred to as "adhesive sheet 210") in the bonded body 240 of this embodiment will be described. First adhesive layer 211 and second adhesive layer 213 in adhesive sheet 210 are the same as first adhesive layer 111 and second adhesive layer 113 in the first embodiment. Furthermore, these adhesive layers may be protected by a separator, as in the first embodiment. Furthermore, the preferred range of adhesive strength of adhesive sheet 210 is also the same as that described in the first embodiment, and the same method as that described in the first embodiment can be used for manufacturing adhesive sheet 210.

[0067] Conductive substrate 212 in adhesive sheet 210 may be made of, for example, a metal or a conductive polymer as long as it has conductivity. Specifically, for example, a metal foil or the like can be used.

[0068] <zygote> The bonded body 240 is a bonded body in which a first adherend 220 and a second adherend 230 are bonded together by a plurality of pressure-sensitive adhesive sheets 210. The first adherend 220 and the second adherend 230 in the bonded body 240 of this embodiment are similar to the adherend 120 and the second adherend 130 in the first embodiment, respectively. In the bonded body 240 of this embodiment, there is no particular limitation on the number of adhesive sheets 210 used to bond the first adherend 220 and the second adherend 230, as long as there are multiple adhesive sheets 210. There are also no particular limitations on the shape or size of the adhesive sheets 210, and each adhesive sheet 210 may be different or the same.

[0069] In the bonded structure 240 of the present embodiment configured as described above, the area of each of the multiple adhesive sheets 210 is smaller than that of a bonded structure obtained by bonding adherends together using a uniform adhesive sheet, and therefore the inclusion of air bubbles during application is suppressed. Furthermore, the bonded structure can be formed by arranging the multiple adhesive sheets 210 so as to avoid irregularities on the surfaces of the adherends. Furthermore, compared to a bonded body obtained by bonding adherends together using a uniform adhesive sheet, the total area of adhesive sheet 210 used is smaller, which is also preferable from the viewpoint of cost reduction.

[0070] In the bonded body 240 of this embodiment, the connecting member 214 is not particularly limited as long as it can electrically connect the conductive base materials 212 of the multiple adhesive sheets 210, but as shown in Figure 5, it is preferable to provide a portion of each adhesive sheet 210 that does not have the second adhesive layer 213, and to place the connecting member 214 in that portion. Connecting member 214 is made of, for example, a metal or a conductive polymer. Specifically, for example, a metal foil can be used. Connecting member 214 may be configured as a single member that electrically connects conductive base materials 212 of all of adhesive sheets 210, or may be configured as a plurality of members that electrically connect conductive base materials 212 of all of adhesive sheets 210, but from the viewpoint of ease of manufacture, it is preferable that connecting member 214 be made of a single member.

[0071] (electrical peeling method) When electrically peeling the bonded structure 240 configured as described above, a voltage is applied to the first adhesive layers 211 of the multiple adhesive sheets 210 via the first adherend 220 and the conductive base material 212. Since the respective conductive base materials 212 of the multiple adhesive sheets 210 that bond the bonded structure 240 of this embodiment are electrically connected by the connecting members 214, it is easy to apply a voltage to the first adhesive layers 211 of all of the adhesive sheets 210 simultaneously. When applying a voltage, it is particularly preferable from the viewpoint of workability to bring the terminals of the voltage application device into contact with the first adherend 220 and the conductive substrate 212 or the connecting member 214 from the same direction.

[0072] In order to facilitate contact of the terminals of the voltage application device with the conductive substrate 212 or the connecting member 214, for example, as shown in the first embodiment, the adhesive sheet 210 or the connecting member 214 may have a portion that protrudes from the first adherend 220 when the bonded body 240 is observed in a plan view from the direction of the first adherend 220. Alternatively, as shown in the first embodiment, the terminal may be brought into contact with the conductive substrate 212 or the connecting member 214 by penetrating the first adherend 220 .

[0073] [Third embodiment] Fig. 6(a) is a side view of a bonded body 340 according to a third embodiment of the present invention (hereinafter simply referred to as "bonded body 340 of this embodiment" or "bonded body 340"), and Fig. 6(b) is a perspective view of the bonded body 340 of this embodiment. Fig. 7 is an exploded perspective view of the bonded body 340 of this embodiment. The bonded structure 340 of this embodiment is a bonded structure in which a first adherend 320 and a second adherend 330 are bonded together using a plurality of electrically peeling adhesive sheets 310, the electrically peeling adhesive sheets 310 being made of an electrically peeling adhesive, the first adherend 320 being attached to one side of the electrically peeling adhesive sheet 310, and the second adherend 330 being attached to the side of the electrically peeling adhesive sheet 310 opposite the first adherend 320, and the first adherend 320 and the second adherend 330 being conductive.

[0074] <Adhesive sheet> First, the electrically peelable adhesive sheet 310 (hereinafter simply referred to as "adhesive sheet 310") in the bonded structure 340 of this embodiment will be described. Adhesive sheet 310 is an adhesive sheet made of an electrically peelable adhesive and does not have a base layer, etc. The components, preferable thickness, etc. of adhesive sheet 310 are the same as those explained for first adhesive layer 111 in the first embodiment.

[0075] The method for manufacturing adhesive sheet 310 is not particularly limited, but for example, adhesive sheet 310 can be formed on a separator (release liner) and then a separator can be attached on top of that to produce adhesive sheet 310 with both sides protected by separators. Alternatively, the adhesive sheet 310 can be produced by directly applying a composition for forming the adhesive sheet 310 to the adherend.

[0076] <zygote> The bonded body 340 is a bonded body in which a first adherend 320 and a second adherend 330 are bonded together by a plurality of adhesive sheets 310. In this embodiment, both the first adherend 320 and the second adherend 330 are conductive, and the same material as the first adherend 120 in the first embodiment can be used for either. In the bonded structure 340 of this embodiment, there is no particular limitation on the number of adhesive sheets 310 used to bond the first adherend 320 and the second adherend 330, as long as there are multiple adhesive sheets 310. The effects achieved by forming a bonded structure using multiple adhesive sheets 310 are the same as those described in the second embodiment. Furthermore, the adhesive sheet 310 in the bonded structure 340 of the third embodiment is a single-layer structure without a substrate, and is therefore very thin, which is particularly advantageous from the viewpoint of miniaturizing the bonded structure 340 of the third embodiment.

[0077] (electrical peeling method) When electrically peeling the bonded structure 340 having the above-described structure, a voltage is applied to the plurality of adhesive sheets 310 via the first adherend 320 and the second adherend 330 . When applying a voltage, it is particularly preferable from the viewpoint of workability to bring the terminals of the voltage application device into contact with the first adherend 320 and the second adherend 330 from the same direction.

[0078] For example, when the terminal is to be brought into contact with both adherends from the direction of the first adherend, in order to facilitate contact with the second adherend 330, the second adherend 330 may be configured so that a portion thereof protrudes beyond the first adherend 320 when the joined body 340 is observed in a plan view from the direction of the first adherend 320, or may be configured to be one size larger than the first adherend 320. Furthermore, as shown in the first embodiment, the terminal may be made to contact the second adherend 330 by penetrating the first adherend 320, and in this case, the terminal may be made to contact the second adherend 330 by further breaking through the adhesive sheet 310.

[0079] [Fourth embodiment] Fig. 8(a) is a side view of a bonded body 440 according to a fourth embodiment of the present invention (hereinafter simply referred to as "bonded body 440 of this embodiment" or "bonded body 440"), and Fig. 8(b) is a perspective view of the bonded body 440 of this embodiment. Fig. 9 is an exploded perspective view of the bonded body 440 of this embodiment. The bonded structure 440 of this embodiment is a bonded structure in which a first adherend 420 and a second adherend 430 are bonded together using a plurality of electrically peeling adhesive sheets 410, and the adhesive sheet 410 is an adhesive sheet comprising a conductive substrate 412, a first adhesive layer 411 made of an electrically peeling adhesive formed on the conductive substrate 412, and a second adhesive layer 413 made of a conductive adhesive formed on the surface of the conductive substrate opposite to the first adhesive layer 411, and the first adhesive layers 411 of the plurality of adhesive sheets 410 are each attached to the first adherend 420, and the second adhesive layers 413 are each attached to the second adherend 430, the first adherend 420 is conductive, the second adherend 430 has a conductive portion 431 that is conductive, and the second adhesive layers 413 of the plurality of adhesive sheets 410 are electrically connected by the conductive portion 431.

[0080] <Adhesive sheet> First, the electrically peelable adhesive sheet 410 (hereinafter simply referred to as "adhesive sheet 410") in the bonded structure 440 of this embodiment will be described. First adhesive layer 411 in adhesive sheet 410 can be the same as first adhesive layer 111 in the first embodiment. Furthermore, the conductive substrate 412 can be the same as the conductive substrate 212 in the second embodiment.

[0081] The second adhesive layer 413 is a layer made of a conductive adhesive. The conductive adhesive constituting the second adhesive layer is not particularly limited, and a known adhesive can be used, for example, an adhesive (such as an acrylic adhesive) containing about 3 to 70 wt % of a conductive component (such as a silver filler) can be used.

[0082] Furthermore, first adhesive layer 411 and second adhesive layer 413 may be protected by a separator, as in the first embodiment. Furthermore, the preferred range of adhesive strength of adhesive sheet 410 is also the same as that described in the first embodiment, and the same method as that described in the first embodiment can be used for manufacturing adhesive sheet 410.

[0083] <zygote> The bonded body 440 is a bonded body in which a first adherend 420 and a second adherend 430 are bonded together by a plurality of adhesive sheets 410 . The first adherend 420 in the bonded body 440 of this embodiment is similar to the adherend 120 in the first embodiment.

[0084] There are no particular limitations on the second adherend 430 as long as it has a conductive portion 431 that is conductive and the second adhesive layers 413 of the multiple adhesive sheets 410 are electrically connected by this conductive portion. The conductive portion may be formed over the entire surface of the second adherend 430 on which the adhesive sheet 410 is attached, or may be formed partially. In addition, when the conductive portion is formed partially, as shown in Fig. 9, the second adhesive layers 413 of all the adhesive sheets 410 may be electrically connected by a single conductive portion 431, or the second adhesive layers 413 of all the adhesive sheets 410 may be electrically connected by a plurality of conductive portions 431.

[0085] The method for forming the conductive portion 431 is not particularly limited, but for example, if the second adherend 430 is a member made of a conductive material such as a metal with an insulating coating, the conductive portion 431 can be formed by scraping off the insulating coating to expose the conductive material. Alternatively, the conductive portion 431 can be formed by coating the surface of the second adherend 430 made of an insulating material with a conductive material such as metal.

[0086] In the bonded structure 440 of this embodiment, there is no particular limitation on the number of adhesive sheets 410 used to bond the first adherend 420 and the second adherend 430, as long as there are multiple adhesive sheets 410. The effects achieved by forming a bonded structure using multiple adhesive sheets 410 are the same as those described in the second embodiment.

[0087] (electrical peeling method) When electrically peeling the bonded structure 440 configured as described above, a voltage is applied to the first adhesive layers 411 of the multiple adhesive sheets 410 via the first adherend 420 and the conductive substrate 412. Since the conductive substrates 412 of the multiple adhesive sheets 410 that bond the bonded structure 440 of this embodiment are each electrically connected by the second adhesive layer 413 and the conductive portion 431, it is easy to apply a voltage to the first adhesive layers 411 of all of the adhesive sheets 410 simultaneously. When applying a voltage, it is particularly preferable from the viewpoint of workability to bring the terminals of the voltage application device into contact with first adherend 420 and conductive substrate 412 or conductive portion 431 from the same direction.

[0088] In order to facilitate contact of the terminal of the voltage application device with the conductive substrate 412 or the conductive portion 431, for example, as shown in the first embodiment, the adhesive sheet 410 or the conductive portion 431 may have a portion that protrudes from the first adherend 420 when the bonded body 440 is observed in a plan view from the direction of the first adherend 420. Alternatively, as shown in the first embodiment, the terminal may be brought into contact with the conductive substrate 412 or the conductive portion 431 by penetrating the first adherend 420 .

[0089] [Fifth embodiment] Fig. 10(a) is a side view showing an outline of a bonded structure delamination method according to a fifth embodiment of the present invention (hereinafter simply referred to as "the delamination method of this embodiment"), Fig. 10(b) is a plan view showing an outline of the delamination method of this embodiment, and Fig. 11 is a perspective view showing an outline of the delamination method of this embodiment. The peeling method of this embodiment is a method for peeling off a bonded structure 540 in which a first adherend 520 and a second adherend 530 are bonded together with a plurality of electrically peeling adhesive sheets 510, and the electrically peeling adhesive sheet 510 comprises a conductive substrate 512 having at least one surface thereof conductive, a first adhesive layer 511 made of an electrically peeling adhesive formed on the conductive surface of the conductive substrate, and a second adhesive layer 512 made of an electrically peeling adhesive formed on the surface of the conductive substrate opposite to the first adhesive layer. The electrically peeling adhesive sheets 510 each have an adhesive layer 513, and the first adherend 520 is conductive and is adhered to the first adhesive layer 511, and the second adherend 530 is adhered to the second adhesive layer 513. The conductive substrates 512 of each of the multiple electrically peeling adhesive sheets 510 are electrically connected by a jig 550, and a voltage is simultaneously applied to the first adhesive layer 511 of each of the multiple electrically peeling adhesive sheets 510, thereby peeling the first adherend 520 and the second adherend 530 from each other.

[0090] <Adhesive sheet> First, an electrically peelable adhesive sheet 510 (hereinafter simply referred to as "adhesive sheet 510") that forms the bonded body 540 that is peeled in the peeling method of this embodiment will be described. First adhesive layer 511, conductive base material 512, and second adhesive layer 513 in adhesive sheet 510 can be the same as first adhesive layer 111, conductive base material 112, and second adhesive layer 113 in the first embodiment. Furthermore, these adhesive layers may be protected by a separator, as in the first embodiment. Furthermore, the preferred range of adhesive strength of adhesive sheet 510 is also the same as that described in the first embodiment, and the same method as that described in the first embodiment can be used for manufacturing adhesive sheet 510.

[0091] <zygote> The bonded structure 540 to be peeled off in the peeling method of this embodiment is a bonded structure in which a first adherend 520 and a second adherend 530 are bonded together by a plurality of pressure-sensitive adhesive sheets 510. The first adherend 520 and the second adherend 530 in the bonded body 540 may be the same as the adherend 120 and the second adherend 130 in the first embodiment, respectively. In the bonded structure 540, the number of adhesive sheets 510 used to bond the first adherend 520 and the second adherend 530 is not particularly limited as long as there are multiple adhesive sheets 510, and there are also no particular limitations on the shape or size. The effects achieved by forming a bonded structure using multiple adhesive sheets 510 are the same as those described in the second embodiment.

[0092] (electrical peeling method) In the peeling method of this embodiment, a voltage is applied to the first adhesive layer of each of the plurality of adhesive sheets 510 via the first adherend 520 and the current-carrying substrate 512. At this time, the current-carrying substrates 512 of each of the plurality of electrically peeling adhesive sheets 510 are electrically connected by a jig 550, so that a voltage is simultaneously applied to the first adhesive layer 511 of each of the plurality of electrically peeling adhesive sheets 510.

[0093] There are no particular limitations on the shape or material of jig 550 as long as it can simultaneously electrically connect each of the multiple electrically releasable pressure-sensitive adhesive sheets 510. One example of jig 550 is a blade-shaped jig as shown in Fig. 10 that can penetrate the first pressure-sensitive adhesive layer of each pressure-sensitive adhesive sheet 510 and contact each current-carrying substrate 512.

[0094] In order to facilitate contact of the jig with the current-carrying substrate 512, the current-carrying substrate 512 may be configured to protrude from the first adherend 520 when the bonded body 540 is observed in a plan view from the direction of the first adherend 520, as shown in FIG. 10, for example. Alternatively, a gap for inserting a jig may be provided in first adherend 520, and jig 550 may be brought into contact with current-carrying substrate 512 through the gap. [Explanation of symbols]

[0095] 110, 210, 310, 410, 510: Electric peeling adhesive sheet 110a: Connected part 110b: Connection part 111, 211, 411, 511: First adhesive layer 112, 512: Base material for energizing 112a, 512a: Conductive layer 112b, 512b: Base material layer 212, 412: Conductive base material 113, 213, 413, 513: second adhesive layer 214: Connecting member 120, 220, 320, 420, 520: First adherend 130, 230, 330, 430, 530: Second adherend 431: Conductive part 140, 240, 340, 440, 540: Zygote 550: Jig

Claims

[Claim 1] A method for removing a bonded structure in which a first adherend and a second adherend are bonded together with a plurality of electrically releasable pressure-sensitive adhesive sheets, comprising: The electrically peelable pressure-sensitive adhesive sheet comprises an electrically conductive substrate having at least one surface thereof being electrically conductive, a first pressure-sensitive adhesive layer formed on the conductive surface of the electrically conductive substrate and made of an electrically peelable pressure-sensitive adhesive, and a second pressure-sensitive adhesive layer formed on the surface of the electrically conductive substrate opposite to the first pressure-sensitive adhesive layer, the first adherend is conductive and is attached to the first pressure-sensitive adhesive layer; the second adherend is attached to the second pressure-sensitive adhesive layer, A method for peeling a bonded body, comprising electrically connecting the conductive substrates of each of the plurality of electrically peelable pressure-sensitive adhesive sheets using a jig, the jig being blade-shaped, and peeling the first adherend from the second adherend while simultaneously applying a voltage to the first adhesive layer of each of the plurality of electrically peelable pressure-sensitive adhesive sheets.

Images