Electrically peelable adhesive

Abstract

The problem of the present invention is solved by an electrically peelable pressure-sensitive adhesive body comprising a base body, a first electrically peelable pressure-sensitive adhesive layer on a first surface of the base body, and a second electrically peelable pressure-sensitive adhesive layer on a second surface of the base body, wherein the first electrically peelable pressure-sensitive adhesive layer and the second electrically peelable pressure-sensitive adhesive layer include an electrically peelable pressure-sensitive adhesive composition containing an acrylic polymer and an ionic liquid; a conductive pattern layer having a void is formed on a surface of the first electrically peelable pressure-sensitive adhesive layer; the first electrically peelable pressure-sensitive adhesive layer can pressure-sensitively adhere to an adherend via the void of the conductive pattern layer; and the ionic liquid is a salt of a cation selected from imidazolium-based cations and an anion selected from (FSO2)2N-, (CF3SO2)2N-, and BF4 -.

Description

[Technical Field]

[0001] The present invention relates to an electro-releasable pressure-sensitive adhesive body.The present invention relates to a method for producing an electro-releasable pressure-sensitive adhesive body.The present invention relates to a method for removing an electro-releasable pressure-sensitive adhesive body. [Background technology]

[0002] Adhesive bodies that can be peeled off from adherends by application of a voltage (hereinafter also referred to as "electrically peelable adhesive bodies") are known. For example, Patent Document 1 describes an electrically peelable adhesive product. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-52056 Summary of the Invention [Problem to be solved by the invention]

[0004] The electrically peelable adhesive product described in Patent Document 1 can be electrically peeled from an insulator by forming a surface layer of the adhesive layer. However, in order to achieve good electrical peeling using the electrically peelable adhesive product of Patent Document 1, a high voltage of about 100 V is required. Therefore, an object of the present invention is to provide an electrically peelable adhesive body that has excellent electrical peeling properties even at a low voltage. [Means for solving the problem]

[0005] Therefore, the following inventions [1] to

[24] are provided. [1] An electrically peelable adhesive body comprising a substrate, a first electrically peelable adhesive layer on a first surface of the substrate, and a second electrically peelable adhesive layer on a second surface of the substrate, the first and second electrically releasing adhesive layers each comprise an electrically releasing adhesive composition including an acrylic polymer and an ionic liquid; a conductive pattern layer having voids is formed on the surface of the first electrically releasing pressure-sensitive adhesive layer; the first electrically releasable pressure-sensitive adhesive layer is capable of adhering to an adherend via voids in the conductive pattern layer, The ionic liquid comprises a cation selected from imidazolium-based cations and (FSO2)2N - , (CF3SO2)2N - and BF4 - The electrodegradable adhesive is a salt with an anion selected from the group consisting of:

[0006] [2] The electrically peelable pressure-sensitive adhesive body according to [1] above, wherein the conductive pattern layer comprises line portions having a lattice shape, a linear shape, a wavy line shape, a curved line shape, or a combination thereof.

[0007] [3] The electrically peelable pressure-sensitive adhesive body according to [2] above, wherein the width of the line portions of the conductive pattern layer is 0.01 mm to 3 mm.

[0008] [4] The electrically peelable adhesive material according to any one of the above [1] to [3], wherein the ionic liquid is 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide and / or 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide.

[0009] [5] The electrically peelable pressure-sensitive adhesive body according to any one of the above [1] to [4], wherein the voids occupy 25% or more and 99% or less of the surface area of ​​the first electrically peelable pressure-sensitive adhesive layer.

[0010] [6] The size of one air gap is 0.2 mm 2 More than 10mm 2 The electrically peelable pressure-sensitive adhesive material according to any one of the above [1] to [5], which is:

[0011] [7] The electrically peelable pressure-sensitive adhesive body according to any one of the above [1] to [6], wherein the conductive pattern layer has a thickness in the range of 1 μm to 50 μm.

[0012] [8] The electrically peelable pressure-sensitive adhesive body according to any one of the above [1] to [7], wherein the conductive pattern layer contains 40% by weight or more of a metal-based conductive material.

[0013] [9] The electrically peelable pressure-sensitive adhesive body according to any one of the above [1] to [8], wherein the conductive pattern layer is formed on the surface of the second electrically peelable pressure-sensitive adhesive layer.

[0014]

[10] The electrically peelable pressure-sensitive adhesive body according to any one of the above [1] to [9], wherein the thickness of the electrically peelable pressure-sensitive adhesive body is in the range of 10 μm to 300 μm.

[0015]

[11] The basis weight of the substrate is 10.0 g / m 2 The electrically peelable pressure-sensitive adhesive body according to any one of the above [1] to

[10] , having a thickness of 10 μm or more and 50 μm or less.

[0016]

[12] The electrically peelable pressure-sensitive adhesive body according to any one of [1] to

[11] above, wherein the content of the ionic liquid in the electrically peelable pressure-sensitive adhesive composition is 10 parts by weight or more and 90 parts by weight or less per 100 parts by weight of the acrylic polymer.

[0017]

[13] The electrically peelable pressure-sensitive adhesive body according to any one of the above [1] to

[12] , wherein the acrylic polymer comprises a copolymer of an alkyl(meth)acrylate having an alkyl group having 1 to 8 carbon atoms, a carboxyl group-containing acrylic monomer, and / or a hydroxyl group-containing acrylic monomer.

[0018]

[14] The electrically peelable pressure-sensitive adhesive body according to any one of the above [1] to

[13] , wherein the electrically peelable pressure-sensitive adhesive composition contains a migration promoter.

[0019]

[15] The electrically disengageable adhesive body according to

[14] above, wherein the migration promoter is an alkyl ether of polyethylene glycol.

[0020]

[16] An electrically peelable pressure-sensitive adhesive body comprising an electrically peelable pressure-sensitive adhesive layer made of an electrically peelable pressure-sensitive adhesive composition containing an acrylic polymer and an ionic liquid, and a conductive pattern layer having voids formed on the surface of the electrically peelable pressure-sensitive adhesive layer, the electrically releasing pressure-sensitive adhesive layer comprises an electrically releasing pressure-sensitive adhesive composition containing an acrylic polymer and an ionic liquid, the electrically peelable pressure-sensitive adhesive layer is capable of adhering to an adherend via voids in the conductive pattern layer, The ionic liquid comprises a cation selected from imidazolium-based cations and (FSO2)2N - , (CF3SO2)2N - and BF4 - The electrodegradable adhesive is a salt with an anion selected from the group consisting of:

[0021]

[17] A step of contacting a substrate with an electrically releasing pressure-sensitive adhesive composition containing an acrylic polymer and an ionic liquid to form a first electrically releasing pressure-sensitive adhesive layer and a second electrically releasing pressure-sensitive adhesive layer; forming a conductive pattern layer on at least the first electrically releasing adhesive layer; Including, The ionic liquid comprises a cation selected from imidazolium-based cations and (FSO2)2N - , (CF3SO2)2N - and BF4 - A method for producing an electroreleasable adhesive material, wherein the electroreleasable adhesive material is a salt with an anion selected from the group consisting of:

[0022]

[18] The manufacturing method described in

[17] above, wherein the conductive pattern layer is lattice-shaped and the width of the line portions of the conductive pattern layer is 0.01 mm or more and 3 mm or less.

[0023]

[19] The manufacturing method according to

[17] or

[18] above, further comprising a step of preparing the electrically peelable pressure-sensitive adhesive composition before the step of forming the first and second electrically peelable pressure-sensitive adhesive layers.

[0024]

[20] The method according to any one of the above

[17] to

[19] , wherein the electrically peelable pressure-sensitive adhesive composition contains a migration promoter.

[0025]

[21] A method for peeling an electrically peelable adhesive body, comprising attaching objects to both sides of the electrically peelable adhesive body described in any one of [1] to

[16] above, and then applying a voltage to the electrically peelable adhesive body.

[0026]

[22] The peeling method described in

[21] above, wherein at least one of the objects is an insulator, and the surface having the first electrically peelable adhesive layer is attached to the insulator so that it is in contact with the surface, and then a voltage is applied to the electrically peelable adhesive.

[0027]

[23] The peeling method according to

[21] or

[22] above, wherein the voltage is in the range of 1 V or more and 100 V or less.

[0028]

[24] The peeling method according to any one of the above

[21] to

[23] , wherein the voltage application time is in the range of 1 second to 600 seconds. [Effects of the Invention]

[0029] According to the present invention, there is provided an electro-releasable pressure-sensitive adhesive material that exhibits excellent electro-releasability even at low voltage. [Brief explanation of the drawings]

[0030] [Figure 1A] FIG. 1 is a schematic diagram of an electro-releasable adhesive body (referred to as an adhesive body) viewed from the horizontal direction. [Figure 1B] 1 is a schematic diagram of an adhesive body in which voids are filled with an adhesive, as viewed from the horizontal direction. [Figure 2A] 1 is a schematic diagram of an adhesive body having conductive patterns formed on both sides, viewed from the horizontal direction. [Figure 2B] 1 is a schematic diagram of an adhesive body having conductive patterns formed on both sides and in which voids are filled with adhesive, as viewed from the horizontal direction. [Figure 3A] FIG. 1 is a plan view of an adhesive body having a grid-shaped conductive pattern layer placed on a horizontal surface and viewed from directly above. [Figure 3B] FIG. 2 is an enlarged view of a portion of a grid-shaped conductive pattern layer. [Figure 4] FIG. 1 is a schematic diagram of an adhesive body without a substrate. [Figure 5A] This is a horizontal view of a composite (composite 1) consisting of an adhesive body, a first conductor adhered to the first electrically peelable adhesive layer of the adhesive body, and a second conductor adhered to the second electrically peelable adhesive layer. [Figure 5B] 1 is a diagram showing an example of a circuit in which electrode terminals are connected to a first conductor and a second conductor of a composite body 1. FIG. [Figure 5C] FIG. 1 is a diagram showing an example in which a voltage is applied to a composite 1. [Figure 6A] FIG. 1 is a horizontal view of a composite (composite 2) consisting of an adhesive body, an insulator adhered to the first electrically releasable adhesive layer of the adhesive body, and a first conductor adhered to the second electrically releasable adhesive layer. [Figure 6B] FIG. 10 is a diagram showing an example of a circuit in which electrode terminals are connected to the conductor and conductive pattern layer of the composite 2. [Figure 6C] FIG. 10 is a diagram showing an example in which a voltage is applied to a composite 2. [Figure 7] 1 is an image of the conductive pattern layer of the adhesive body 1. [Figure 8A] FIG. 1 is a horizontal view of the structure of a composite formed by adhering an insulator to the first electrically releasing adhesive layer and an electrical conductor to the second electrically releasing adhesive layer of any one of adhesive bodies 1 to 3. [Figure 8B] 8B is a diagram showing a circuit in which electrode terminals are connected to the conductors and conductive pattern of the composite of FIG. 8A. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0031] [Electro-peelable adhesive] An electro-releasable adhesive body (hereinafter simply referred to as an adhesive body) according to one embodiment of the present invention comprises a planar substrate, a first electro-releasable adhesive layer formed on a first surface of the substrate, and a second electro-releasable adhesive layer formed on a second surface of the substrate, and has electro-releasability. "Electro-releasability" refers to the ability to separate an electrical conductor attached to the adhesive body by applying a voltage to the adhesive body to reduce the adhesiveness of the adhesive body. A conductive pattern layer is formed on at least the surface of the first electro-releasable adhesive layer. A schematic diagram of the structure of the adhesive body is shown in FIG. 1A. In FIG. 1A, 10 denotes the electro-releasable adhesive body, 11 the first electro-releasable adhesive layer, 12 the second electro-releasable adhesive layer, 13 the substrate, 14 the conductive pattern layer, and 15 a gap. Although not shown in FIG. 1A, in the following drawings, 1 denotes a first electrical conductor, 2 the second electrical conductor, 20 the insulator, and 100 the DC power source.

[0032] The adhesive body may have a conductive pattern layer formed not only on the first electrically releasing adhesive layer but also on the second electrically releasing adhesive layer, an example of which is shown in Figure 2A.

[0033] The first and second electrically releasing adhesive layers each contain an electrically releasing adhesive composition (hereinafter also referred to simply as the composition; the electrically releasing adhesive composition will be described later), and part or all of each of both surfaces of the adhesive body is adhesive. The adhesive body of the present invention may take the form of, for example, a double-sided sheet or a double-sided tape. It is preferable that the adhesive body has an adhesive strength of 3 N / 25 mm or more before application of a voltage.

[0034] The substrate refers to a planar object on which a composition can be applied to form an adhesive layer, or which can form an adhesive layer together with the composition. The substrate does not have to be completely flat, and may be partially or entirely uneven. The substrate may also have at least one through-hole. The substrate is not particularly limited as long as the adhesive layer is ionically conductive when a voltage is applied to the adhesive sheet.

[0035] Examples of the substrate include foils or plates made of metals such as aluminum, copper, silver, and gold, or alloys of these metals, as well as fibers such as plant fibers, inorganic and chemical fibers, and porous films. Among these, substrates made of fibers are preferred, and substrates made of plant fibers are more preferred. Substrates made of plant fibers include, for example, Western paper and Japanese paper. Substrates made of inorganic and chemical fibers include, for example, nonwoven fabrics and woven fabrics such as polyester (particularly, nonwoven fabrics made of polyethylene terephthalate), carbon fibers, and glass fibers. Examples of porous films include, for example, polyimide and polyester films. The ability of the composition to penetrate the gaps between fibers and the pores of porous films allows the adhesive layer to be ionically conductive, thereby enabling the formation of a thin adhesive sheet. The substrate is preferably a fiber made of an insulator. Examples of fibers made of an insulator include, for example, plant fibers and polyester fibers.

[0036] The thickness of the substrate is not particularly limited, but is, for example, 5 μm to 50 μm, preferably 10 μm to 40 μm, and more preferably 10 μm to 30 μm. The upper limit of the substrate thickness is, for example, 50, 45, 40, 35, or 30 μm. The lower limit of the substrate thickness is, for example, 5, 7, 10, 12, or 15 μm.

[0037] The basis weight of the substrate is not particularly limited, but is, for example, 50 g / m 2 less than or equal to 2 g / m 2 More than 30g / m 2 Preferably, it is 2 g / m or less. 2 More than 20g / m 2 More preferably, it is 2 g / m or less. 2 More than 15g / m 2 More preferably, it is 2 g / m or less. 2 More than 10g / m 2 The upper limit of the basis weight is, for example, 50, 40, 30, 20, or 10 g / m 2 The lower limit of the basis weight is, for example, 2.0, 2.5, 3.0, 4.0, or 5.0 g / m 2In particular, the core material is 10.0 g / m 2 It is particularly preferable that the adhesive sheet has a basis weight of 10 μm or more and a thickness of 10 μm or more and 35 μm or less. By having such a basis weight and thickness, it is possible to make a thin adhesive body without affecting the electrical peeling properties.

[0038] The thickness of the adhesive body is not particularly limited, but is preferably 10 μm or more and 300 μm or less, more preferably 10 μm or more and 150 μm or less, and even more preferably 10 μm or more and 100 μm or less. The upper limit of the thickness of the adhesive body is, for example, 300, 200, or 100 μm. The lower limit of the thickness of the adhesive body is, for example, 1, 5, 10, 15, 20, 25, or 30 μm.

[0039] The thickness of the adhesive body or the substrate can be measured using a known thickness measuring device. An example of a thickness measuring device is a Peacock precision measuring instrument. The thickness here refers to the average value measured using the thickness measuring device at at least five randomly selected locations on the object to be measured. The first and second electrically releasing adhesive layers are layers of the composition formed on each surface of the substrate. The adhesive layer may consist solely of the composition permeated into the substrate. In this case, the first and second electrically releasing adhesive layers refer to the adhesive portions on the surface of the substrate.

[0040] (Electrically Peelable Adhesive Composition) The composition contains an acrylic polymer as a pressure-sensitive adhesive. The acrylic polymer can be obtained by polymerizing an acrylic monomer in the presence of any polymerization initiator. Any acrylic polymer can be used as a pressure-sensitive adhesive. From the viewpoint of adhesiveness, the weight-average molecular weight of the acrylic polymer is preferably 100,000 to 5,000,000, more preferably 200,000 to 4,000,000, and even more preferably 300,000 to 3,000,000. Here, the weight-average molecular weight refers to the weight-average molecular weight converted into polystyrene. Specifically, it may be the weight-average molecular weight converted into polystyrene calculated using Shodex GPC (System 21) with tetrahydrofuran as the mobile phase. The amount of the acrylic polymer in the acrylic pressure-sensitive adhesive is not particularly limited, but is preferably 10 to 70 wt% and more preferably 20 to 50 wt% of the total weight of the pressure-sensitive adhesive.

[0041] The acrylic monomer constituting the acrylic polymer is not particularly limited, and known acrylic monomers used in pressure-sensitive adhesives can be used. Among these, the acrylic monomer preferably contains an alkyl(meth)acrylate, and more preferably contains an alkyl(meth)acrylate having an alkyl group having 1 to 14 carbon atoms. The alkyl(meth)acrylate may account for 100% by weight of the total weight of the acrylic monomers contained in the pressure-sensitive adhesive, preferably 40% to 100% by weight, more preferably 50% to 98% by weight, more preferably 70% to 98% by weight, and even more preferably 85% to 98% by weight. Note that "(meth)acrylate" refers to either methacrylate or acrylate.

[0042] Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, and dodecyl (meth)acrylate. These alkyl (meth)acrylates may be used alone or in combination of two or more. Among these alkyl (meth)acrylates, alkyl (meth)acrylates having an alkyl group containing 1 to 8 carbon atoms are preferred, alkyl (meth)acrylates having an alkyl group containing 1 to 4 carbon atoms are more preferred, n-butyl (meth)acrylate is more preferred, and n-butyl acrylate is more preferred.

[0043] Examples of acrylic monomers other than alkyl (meth)acrylates include carboxyl group-containing (meth)acrylates such as acrylate, methacrylate, carboxyethyl (meth)acrylate, and carboxypentyl (meth)acrylate, and hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, (4-hydroxymethylcyclohexyl)-methyl acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate. These acrylic monomers other than alkyl (meth)acrylates may be used alone or in combination of two or more.

[0044] The amount of the acrylic monomer other than the alkyl (meth)acrylate is not particularly limited and may be 100% by weight of the total weight of the acrylic monomer, but is preferably 1% by weight or more and less than 50% by weight, more preferably 2% by weight or more and 40% by weight or less, more preferably 3% by weight or more and 30% by weight or less, and even more preferably 3% by weight or more and 15% by weight or less.

[0045] The acrylic pressure-sensitive adhesive preferably contains, as the acrylic polymer, an alkyl(meth)acrylate having an alkyl group having from 1 to 8 carbon atoms, a carboxyl group-containing acrylic monomer, and / or a copolymer of a hydroxyl group-containing acrylic monomer. When the acrylic polymer contains this copolymer, the pressure-sensitive adhesive has even better adhesive strength.

[0046] When the acrylic polymer contains a carboxyl group-containing monomer and / or a hydroxyl group-containing monomer, the total content of these two monomers is not particularly limited, but is preferably 1% by weight or more and 20% by weight or less of the total monomer amount, and more preferably 1% by weight or more and 10% by weight or less.

[0047] The glass transition temperature (Tg) of the acrylic polymer is preferably not higher than 0° C., more preferably not higher than −20° C., and even more preferably not higher than −40° C. The Tg can be calculated, for example, based on the Fox equation below. 1 / Tg=(W1 / Tg1)+(W2 / Tg2)+·····+(Wn / Tgn) The glass transition temperature can be measured, for example, by differential thermal analysis (DTA).

[0048] A vinyl monomer may be added to the acrylic polymer as needed. Examples of the vinyl monomer include itaconic acid, maleic acid, crotonic acid, maleic anhydride, itaconic anhydride, vinyl acetate, N-vinylpyrrolidone, N-vinylcarboxylic acid amides, styrene, and N-vinylcaprolactam. These vinyl monomers may be used alone or in combination of two or more.

[0049] The acrylic polymer may be crosslinked by the action of a crosslinking agent. Examples of crosslinking agents include isocyanate-based crosslinking agents such as toluene diisocyanate and methylene bisphenyl isocyanate. The amount of crosslinking agent is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 10 parts by weight, and even more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the acrylic polymer. Crosslinking the acrylic polymer can improve the creep resistance and / or shear resistance of the layer formed by the composition on a core material.

[0050] Examples of polymerization initiators used in polymer synthesis include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylpropionamidine) disulfide, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4,4-trimethylpentane), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis[2-methyl-N-(phenylmethyl)-propionamidine]dihydrochloride, and 2,2'-azobis[2-(3,4,5,6-tetrahydropyrimidin-2-yl)propionamidine]dihydrochloride. Examples of polymerization initiators include azo-based polymerization initiators such as [2-(2-imidazolin-2-yl)propane]dihydrochloride and 2,2'-azobis[2-(2-imidazolin-2-yl)propane]; persulfate-based polymerization initiators such as potassium persulfate and ammonium persulfate; peroxide-based polymerization initiators such as benzoyl peroxide, hydrogen peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclododecane, 3,3,5-trimethylcyclohexanoyl peroxide, and t-butyl peroxypivalate; and redox-based polymerization initiators composed of persulfates and sodium bisulfite. These polymerization initiators may be used alone or in combination. UV irradiation or radiation exposure may also be used. The polymerization initiator is preferably used in an amount of 0.005 to 1 part by weight per 100 parts by weight of the acrylic monomer. By using the polymerization initiator in this range, an acrylic polymer with excellent adhesive properties can be formed.

[0051] (ionic liquid) Ionic liquids are combinations of cations and anions that are liquid at room temperature, and are also called room-temperature molten salts. Ionic liquids have properties such as non-flammability, non-volatility, and chemical stability. When a voltage is applied to an ionic liquid, anions migrate to the anode side and cations migrate to the cathode side. It is believed that the migration of anions and cations to the vicinity of the electrode, or the occurrence of an oxidation-reduction reaction of the anions or cations at the interface between the electrode and the electro-releasable pressure-sensitive adhesive composition, weakens the adhesive strength of the electro-releasable pressure-sensitive adhesive composition, resulting in improved releasability.

[0052] The ionic liquid is a mixture of a cation selected from imidazolium-based cations and (FSO2)2N - , (CF3SO2)2N - and BF4 - In combination with an anion selected from:

[0053] Ionic liquids are available from Daiichi Kogyo Seiyaku, Kanto Chemical, Koei Chemical Industry, and others. For example, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMI-FSI) and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI) are available from Daiichi Kogyo Seiyaku, and 1-ethyl-3-methylimidazolium hexafluorophosphate is available from Koei Chemical Industry. The combinations of cations and anions contained in EMI-FSI and EMI-TFSI are as follows:

[0054] [ka]

[0055] [ka]

[0056] The amount of ionic liquid contained in the electrically releasing pressure-sensitive adhesive composition is not particularly limited, but is preferably 1 to 90 parts by weight, more preferably 5 to 80 parts by weight, more preferably 5 to 50 parts by weight, more preferably 5 to 45 parts by weight, and even more preferably 5 to 35 parts by weight, per 100 parts by weight of the acrylic polymer. The upper limit of the amount of ionic liquid contained in the electrically releasing pressure-sensitive adhesive composition is, for example, 90 parts by weight, 80 parts by weight, 70 parts by weight, 60 parts by weight, 50 parts by weight, 45 parts by weight, 40 parts by weight, 35 parts by weight, or 30 parts by weight, per 100 parts by weight of the acrylic polymer. The lower limit of the amount of ionic liquid contained in the electrically releasing pressure-sensitive adhesive composition is, for example, 1 part by weight, 3 parts by weight, 5 parts by weight, 7 parts by weight, 9 parts by weight, 10 parts by weight, 15 parts by weight, or 20 parts by weight, per 100 parts by weight of the acrylic polymer. The ionic liquid may be a combination of one cation and one anion, or a combination of multiple types of cations and anions.

[0057] (Transportation promoter) In this embodiment, the composition may contain a migration promoter that assists ion migration when a voltage is applied. Examples of the migration promoter include polyethylene glycol and alkyl ethers of polyethylene glycol, and alkyl ethers of polyethylene glycol are preferred.

[0058] The molecular weight of the migration promoter is not particularly limited, but preferably has a weight average molecular weight of 120 to 600, more preferably 120 to 550, more preferably 120 to 500, and even more preferably 120 to 360. The upper limit of the weight average molecular weight of the migration promoter is, for example, 600, 580, 550, 530, 500, 470, 450, 430, 400, 370, 355, 350, or 340. The lower limit of the weight average molecular weight of the migration promoter is, for example, 120, 125, 130, 135, 140, 145, 150, 155, 160, or 170. The weight average molecular weight here refers to the weight average molecular weight in terms of polystyrene.

[0059] Examples of polyethylene glycol alkyl ethers include polyethylene glycol mono(di)methyl ether, polyethylene glycol mono(di)ethyl ether, polyethylene glycol mono(di)propyl ether, polyethylene glycol mono(di)isopropyl ether, polyethylene glycol mono(di)butyl ether, polyethylene glycol mono(di)isobutyl ether, polyethylene glycol mono(di)methyl ether, and polyethylene glycol mono(di)pentyl ether. Among these, polyethylene glycol alkyl ethers having a weight-average molecular weight of 120 to 360 are preferred, and polyethylene glycol mono(di)methyl ether having a weight-average molecular weight of 120 to 360 is more preferred. Among these, those selected from tetraethylene glycol dimethyl ether (dimethyltetraglycol), diethylene glycol dibutyl ether, triethylene glycol butylmethyl ether, dimethyltriglycol, and triethylene glycol monomethyl ether are more preferred, and tetraethylene glycol dimethyl ether is more preferred. Polyethylene glycol alkyl ethers are available from Nippon Nyukazai Co., Ltd., Toho Chemical Industry Co., Ltd., and the like. The polyethylene glycol alkyl ethers used may be used alone or in combination of two or more.

[0060] The amount of the migration promoter contained in the composition is not particularly limited, but may be, for example, 1 part by weight to 90 parts by weight, 5 parts by weight to 80 parts by weight, 5 parts by weight to 50 parts by weight, 5 parts by weight to 40 parts by weight, or 5 parts by weight to 30 parts by weight, relative to 100 parts by weight of the acrylic polymer. The upper limit of the migration promoter contained in the composition is, for example, 90 parts by weight, 80 parts by weight, 70 parts by weight, 60 parts by weight, 50 parts by weight, 40 parts by weight, or 30 parts by weight, respectively, relative to 100 parts by weight of the acrylic polymer. The lower limit of the migration promoter contained in the composition is, for example, 1 part by weight, 5 parts by weight, 10 parts by weight, or 15 parts by weight, relative to 100 parts by weight of the acrylic polymer.

[0061] (organic solvent) The composition may contain an organic solvent. The organic solvent is not particularly limited, and examples include known organic solvents that can be used in pressure-sensitive adhesives. The organic solvent may be either a hydrophilic or hydrophobic organic solvent. Examples of hydrophilic organic solvents include methanol, ethanol, 1-propanol, 2-propanol, n-butyl alcohol, sec-butyl alcohol, isobutanol, tert-butyl alcohol, acetonitrile, acetone, and dimethylformamide. Examples of hydrophobic organic solvents include aliphatic hydrocarbons such as hexane, heptane, and isooctane; esters such as methyl acetate, ethyl acetate, and propyl acetate; aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, 1-chlorobutane, and chlorobenzene; ethers such as diethyl ether and t-butyl methyl ether; and ketones such as methyl ethyl ketone and methyl isobutyl ketone. These organic solvents may be used alone or in combination. When an organic solvent is used, the proportion of the organic solvent used is preferably adjusted so that the solid content of the acrylic polymer is 10% by weight or more, and more preferably adjusted so that the solid content is 20% by weight or more and 50% by weight or less.

[0062] (additives) In addition to the above components, the composition of the present embodiment may contain additives such as conductive materials, fillers, plasticizers, antioxidants, flame retardants, colorants, surfactants, and highly water-absorbent polymers.

[0063] Conductive materials are mainly classified into carbon-based conductive materials and metal-based conductive materials. Examples of carbon-based conductive materials include nanocarbon or carbon fiber [e.g., vapor-grown carbon fiber (VGCF) or carbon nanofiber], and more specifically, natural graphite, artificial graphite, acetylene black, ketjen black, furnace black, etc. Examples of metal-based conductive materials include metals such as Cu, Ni, Al, Ag, Au, Pt, Zn, and Mn, or alloys thereof. The conductive materials may be used alone or in combination.

[0064] Examples of fillers include silica, diatomaceous earth, alumina, zinc oxide, magnesium oxide, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, calcium silicate, talc, mica, bentonite, activated clay, glass fiber, aluminum nitride, etc. The fillers may be used alone or in combination of two or more types.

[0065] Examples of plasticizers include polyols such as glycerin, diglycerin, triglycerin, ethylene glycol, propylene glycol, and polyethylene glycol, aliphatic polycarboxylic acid esters such as adipate esters, citrate esters, sebacate esters, azelaate esters, and maleate esters, aromatic polycarboxylic acid esters such as terephthalate esters, isophthalate esters, phthalate esters, trimellitate esters, and benzoate esters, polyesters, etc. Plasticizers may be used alone or in combination of two or more types.

[0066] Examples of the antioxidant include phenol-based antioxidants, amine-based antioxidants, lactone-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, etc. The antioxidants may be used alone or in combination of two or more types.

[0067] Examples of the flame retardant include additives and reactive flame retardants such as phosphorus- and halogen-containing organic compounds, bromine- or chlorine-containing organic compounds, ammonium polyphosphate, aluminum hydroxide, and antimony oxide. The flame retardants may be used alone or in combination.

[0068] Examples of colorants include inorganic pigments such as carbon black, titanium oxide, zinc oxide, iron oxide, and mica, and organic pigments such as coupling azo pigments, condensed azo pigments, anthraquinone pigments, thioindigo pigments, dioxazone pigments, and phthalocyanine pigments. The colorants may be used alone or in combination.

[0069] Examples of surfactants include anionic surfactants such as pyridinium salts, benzethonium chloride, alkylbenzenesulfonates, α-olefinsulfonates, and phosphate esters, and nonionic surfactants such as amine salts (alkylamine salts, imidazolines, and the like), sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether, and polyoxyethylene dodecyl ether. The surfactants may be used alone or in combination.

[0070] Examples of superabsorbent polymers include sodium poly(meth)acrylate, potassium poly(meth)acrylate, ammonium poly(meth)acrylate, calcium poly(meth)acrylate, magnesium poly(meth)acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, poly(meth)acrylamide, poly-N-isopropylamide, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, and derivatives or crosslinked products thereof. The superabsorbent polymers may be used alone or in combination of two or more types.

[0071] The amount of these additives (excluding adhesives other than the acrylic polymer) contained in the composition is not particularly limited, but can be, for example, 0.1 parts by weight or more and 200 parts by weight or less, or 1 part by weight or more and 100 parts by weight or less, per 100 parts by weight of the acrylic polymer.

[0072] The method for forming the first and second electrically releasing adhesive layers is not particularly limited. For example, they can be formed by applying the composition to a release-treated polyethylene terephthalate film (release film) or the like and then laminating the substrate thereto. After applying the composition to the release film, the composition may be heated to dry the composition. Another example of formation is by applying the composition to a substrate. The method for applying these compositions is not particularly limited. Examples include direct application with a brush or the use of a coating device used in the manufacture of adhesive tapes. Examples of coating devices that can be used include spin coaters, gravure coaters, applicators, multi-coats, die coaters, bar coaters, roll coaters, blade coaters, knife coaters, and spray coaters. The thickness of the first and second electrically releasing adhesive layers is not particularly limited. However, it is preferably 1 μm to 200 μm, more preferably 1 μm to 50 μm, and even more preferably 5 μm to 30 μm. When an electrically releasing adhesive layer is formed on both sides of the adhesive layer, the two electrically releasing adhesive layers may have the same thickness or different thicknesses. Furthermore, the two electrically releasing adhesive layers may have the same composition or different compositions. The surface of the adhesive body to be used may be protected by a release film, release paper, or the like until use.

[0073] (Conductive pattern layer) The conductive pattern layer is formed on the surface of the first electrically releasing adhesive layer (or the second electrically releasing adhesive layer) and has voids. When the surface of the adhesive body having the conductive pattern layer is attached to an adherend, the first electrically releasing adhesive layer (or the second electrically releasing adhesive layer) adheres to the adherend via the voids in the conductive pattern. Here, adhesion via the voids does not mean that the voids themselves are between the adherend and the first electrically releasing adhesive layer (or the second electrically releasing adhesive layer) and cause adhesion, but rather means that the adhesive body filled in the voids adheres to the adherend.

[0074] As long as the gaps between the line portions can be adhered by the first electrically releasing adhesive layer (or the second electrically releasing adhesive layer if the conductive pattern layer is formed on the second electrically releasing adhesive layer) during use, the gaps may be free of adhesive before use, or may be partially or entirely filled with adhesive. FIGS. 1A and 2A show examples in which no adhesive is present in the gaps before use. When no adhesive is present in the gaps before use, the gaps are filled with the electrically releasing adhesive composition, for example, by applying pressure between the adhesive and the adherend when attaching the adhesive to the adherend. FIGS. 1B and 2B show the state in which the electrically releasing adhesive composition has filled the gaps. In this way, the electrically releasing adhesive composition of the first electrically releasing adhesive layer (or the second electrically releasing adhesive layer) fills the gaps, making the electrically releasing adhesive composition available for contact with the adherend, and thus enabling the adhesive to adhere to the adherend.

[0075] The pressure-sensitive adhesive of this embodiment induces electro-peeling by passing electricity through the conductive pattern layer when energized. Therefore, even if the adherend fixed to the surface having the conductive pattern layer is an insulator, electro-peeling can be caused by passing electricity through the conductive pattern layer. The conductive pattern layer is formed so as to be continuous on the first electro-peeling adhesive layer (or the second electro-peeling adhesive layer). "Continuously formed" refers to the conductive pattern layer being formed without interruption on the layer. This is because, in the pressure-sensitive adhesive, the conductive pattern layer is a region through which electricity flows when energized. If two conductive patterns exist discontinuously on the same surface, even if one conductive pattern can be energized, the other conductive pattern may not. In this case, regions where electro-peeling cannot occur or where electricity cannot be passed will be generated. This creates regions where electro-peeling does not occur, significantly reducing the electro-peeling properties of the pressure-sensitive adhesive.

[0076] The shape of the conductive pattern layer is not particularly limited as long as it is formed continuously, but it is preferable that the conductive pattern layer has a combination of a certain pattern. By having a certain pattern, electricity can be uniformly applied to the adhesive body when it is energized. The conductive pattern layer is preferably composed of line portions having a grid-like, linear, wavy, curved, or combination thereof, and more preferably a grid-like line portion. Examples of adhesive bodies having a grid-like conductive pattern layer are shown in Figures 3A and 3B. Figure 3A is a top view of an adhesive body having a grid-like conductive pattern layer placed on a horizontal surface. Figure 3B is an enlarged view of a portion of the adhesive body shown in Figure 3A. In Figures 3A and 3B, the white lines forming the grid represent the conductive pattern layer and the line portions that form the conductive pattern layer, and the black dots represent gaps between the line portions of the conductive pattern layer. Forming a dense conductive pattern layer in the adhesive body in this way can further improve the electro-separation properties of the adhesive body.

[0077] The width (line width) of the line portion of the conductive pattern layer is not particularly limited, but it is preferable that the line width be uniform. The line width is preferably 0.01 mm or more and 3 mm or less, more preferably 0.02 mm or more and 2 mm or less, and even more preferably 0.02 mm or more and 1 mm or less. Having a line width within this range enables electrical peeling to be performed at a lower voltage. Note that the line width here does not refer to the length of the line portion in the direction in which the line extends, but rather the length perpendicular to the direction in which the line extends. When the line width of the conductive pattern layer is not uniform, it is preferable that the minimum and maximum line widths are substantially within the above-mentioned range. "Substantially" refers, for example, to a case where only a small portion of the conductive pattern on the adhesive body does not have the above-mentioned line width, while the rest is within the above-mentioned line width range. For example, a case where a terminal for current supply is formed in a portion of the conductive pattern, and this terminal portion does not satisfy the above-mentioned line width condition, can be mentioned.

[0078] The thickness of the conductive pattern layer is not particularly limited, but is preferably in the range of 1 μm to 50 μm, and more preferably in the range of 1 μm to 30 μm.

[0079] The shape of the voids is not particularly limited as long as a closed space is formed by the line portion. Examples of the shape of the voids include polygons such as triangles, squares, pentagons, and hexagons, circles, irregular shapes, and combinations thereof. The number of voids is also not particularly limited, but the number of voids per 1 cm of the adhesive body is preferably 100. 2 Preferably, there are 10 to 300 particles, more preferably 30 to 100 particles. 2 The number of voids inside is calculated by placing the adhesive body on a horizontal surface and measuring the area of ​​the adhesive body when viewed from directly above and the number of voids.

[0080] The area ratio of the voids is not particularly limited, but preferably occupies 25% to 99% of the surface of the first electrically releasing adhesive layer (or the second electrically releasing adhesive layer if a conductive pattern layer is formed on the second electrically releasing adhesive layer), more preferably 30% to 97% and even more preferably 40% to 95%. Note that the "area" here refers to the area occupied by the voids when the adhesive body is placed on a horizontal surface and viewed from directly above. By having the void area within this range, an adhesive body can be obtained that combines higher adhesion with excellent electrical releasability.

[0081] The size of the gap is not particularly limited, but the size of one gap is 0.2 mm. 2 More than 10mm 2 Preferably, it is less than 0.25 mm 2 4mm or more 2 It is more preferable that it is 0.4 mm or less. 2 Over 2.5mm 2 It is more preferable that the size of the voids is not more than 100%. When the size of the voids is in this range, it is possible to obtain an adhesive body that achieves both higher adhesiveness and excellent electrical peeling properties.

[0082] The conductive pattern layer is not particularly limited as long as it is made of a conductive material. For example, the above-mentioned carbon-based conductive material or metal-based conductive material can be used. Among these, it is preferable that the conductive layer contains a metal-based conductive material, and more preferably that the conductive layer contains 40% by weight or more of a metal-based conductive material. As the metal-based conductive material, it is particularly preferable that the conductive layer contains Ag. Specific examples of the conductive pattern layer include Cu mesh, Ag mesh, silver paste (a mixture of Ag, resin, etc.), carbon paste (a mixture of carbon-based conductive material, resin, etc.), metal cloth, conductive cloth, etched aluminum foil, metal foil, etc. Specific examples of silver paste include Dotite FA-345 manufactured by Fujikura Chemical Co., Ltd.

[0083] The conductive pattern layer may contain a resin component in addition to the carbon-based conductive material or metal-based conductive material, such as the silver paste or carbon paste exemplified above. Examples of the resin component include thermosetting resins and thermoplastic resins, with thermosetting resins being preferred. Examples of thermosetting resins include polyester resins, phenolic resins, and acrylic resins. The resin component preferably accounts for 20% by weight or less of the conductive pattern layer, more preferably 10% by weight or less, and even more preferably 5% by weight or less.

[0084] The method for forming the conductive pattern layer is not particularly limited, and examples thereof include attaching a metal cloth to the first electrically peelable adhesive layer, forming a conductive pattern directly on the first electrically peelable adhesive layer using the above-mentioned coating device, forming a conductive pattern on a release film using the above-mentioned coating device, and then attaching this to the first electrically peelable adhesive layer.

[0085] The conductive pattern layer may have a terminal for applying a voltage to a part of the conductive pattern layer. The terminal may be made of the same material as the conductive pattern layer or a different material. The terminal is preferably made of the above-mentioned metallic conductive material.

[0086] The conductive pattern layer may partially protrude from the first electrically releasable adhesive layer, which allows electrode terminals to be attached to the protruding conductive pattern layer, facilitating the electrical peeling process.

[0087] The temperature at which the peeling is performed is not particularly limited, but it is preferable to perform the peeling at room temperature.

[0088] One embodiment of the present invention is an adhesive body comprising an electrically releasing adhesive layer made of an electrically releasing adhesive composition containing an acrylic polymer and an ionic liquid, and a conductive pattern layer having voids formed on the surface of the electrically releasing adhesive layer. A schematic diagram of the adhesive body's configuration is shown in Figure 4. In Figure 4, 10 denotes the electrically releasing adhesive body, 11 denotes the first electrically releasing adhesive layer, 14 denotes the conductive pattern layer, and 15 denotes the voids. By adhering the conductive pattern layer of this adhesive body to an insulator and the electrically releasing adhesive layer to a conductor (described below), electrical peeling by passing current becomes possible even on an insulator. Alternatively, an adhesive body having the aforementioned substrate can be formed by adhering the adhesive body to a substrate. The electrically releasing adhesive layer, conductive pattern layer, acrylic polymer, and ionic liquid are as described above.

[0089] [Method of manufacturing an electro-releasable adhesive body] This embodiment includes a step of contacting a substrate with an electrically releasing pressure-sensitive adhesive composition containing an acrylic polymer and an ionic liquid to form a first electrically releasing pressure-sensitive adhesive layer and a second electrically releasing pressure-sensitive adhesive layer, and a step of forming a conductive pattern layer on at least the first electrically releasing pressure-sensitive adhesive layer, wherein the ionic liquid is a cation selected from imidazolium-based cations and (FSO2)2N - , (CF3SO2)2N - and BF4 - The present invention provides a method for producing an electroreleasable adhesive material, which is a salt with an anion selected from the group consisting of: The substrate, the acrylic polymer, the ionic liquid, the electrically releasing pressure-sensitive adhesive composition, the first electrically releasing pressure-sensitive adhesive layer and the second electrically releasing pressure-sensitive adhesive layer are as described above.

[0090] Contacting the substrate with the electrically releasing pressure-sensitive adhesive composition includes, for example, allowing the electrically releasing pressure-sensitive adhesive composition to penetrate into the substrate, or contacting the electrically releasing pressure-sensitive adhesive composition with each of the two surfaces of the substrate to form a first electrically releasing pressure-sensitive adhesive layer and a second electrically releasing pressure-sensitive adhesive layer.

[0091] The method for forming the first and second electrically releasing adhesive layers is not particularly limited, and they can be formed, for example, by applying the composition to a release-treated polyethylene terephthalate film (release film) or the like and laminating a substrate thereto. After applying the composition to the release film, the composition may be heated to dry the composition. In another example, the layers can be formed by applying the composition to a substrate. The composition can be applied using the above-mentioned application device. If the substrate is made of fibers or has holes, the attached electrically releasing adhesive composition will penetrate into the fibers or holes. At this time, the attached substrate may be pressurized. Applying pressure makes it easier for the electrically releasing adhesive composition to penetrate into the substrate. Pressure may be applied from only one side of the core material or from both sides. The adhesive layer may consist solely of the composition permeating into the substrate. In this case, the first electrically releasing adhesive layer and the second electrically releasing adhesive layer refer to the adhesive portions on the surface of the substrate.

[0092] A step of preparing an electrically peelable pressure-sensitive adhesive composition may be included before the step of contacting an electrically peelable pressure-sensitive adhesive composition containing an acrylic polymer and an ionic liquid with a substrate to form a first electrically peelable pressure-sensitive adhesive layer and a second electrically peelable pressure-sensitive adhesive layer. The electrically peelable pressure-sensitive adhesive composition can be prepared, for example, by stirring an acrylic polymer, an ionic liquid, an optional crosslinking agent, etc. The stirring method is not particularly limited, and any known stirring method can be used. Specific examples include stirring the acrylic polymer, the ionic liquid, the migration promoter, the optional crosslinking agent, etc. using a V-type mixer or a mixer (such as a dissolver, homomixer, or planetary mixer). The above-mentioned additives may be added during stirring.

[0093] A migration promoter may be included in the preparation of the electroreleasable pressure-sensitive adhesive composition, as described above.

[0094] [Method for removing electrically releasable adhesive material] This embodiment also provides a method for peeling off an electro-peelable adhesive body by attaching objects to both sides of the electro-peelable adhesive body and then applying a voltage to the electro-peelable adhesive body.

[0095] The object may be a conductor or an insulator. Examples of conductors include metal plates, metal products, or metal workbenches made of metals such as iron, aluminum, copper, silver, or gold, or alloys of these metals; metal plates, metal products, foils (thickness less than 100 μm), and plates (thickness 100 μm or more) made of metals such as iron, aluminum, copper, silver, or gold, or alloys of these metals; meshes or fabrics containing fibers mixed with or coated with these metals or alloys; resin sheets containing these metals or alloys; and resin plates with a layer containing these metals, alloys, or conductive metal oxides. Among these, materials with a resistance value of 1000 Ω / sq or less are preferred. Examples of the metal products include metal cases enclosing batteries, metal vehicle parts, electronic components such as circuit boards, etc. Examples of insulating materials include wooden plywood, plastic products, and non-metallic work benches.

[0096] An example of electro-release using an adhesive body is shown below. For example, a composite (composite 1) can be formed by adhering a first conductor to the first electrically releasing adhesive layer of the adhesive body and a second conductor to the second electrically releasing adhesive layer. An example of the composite is shown in Figure 5A. Figure 5A is a horizontal cross-section of a composite placed with the first conductor at the bottom, cut vertically (the same applies to other examples below).

[0097] Figure 5B shows composite 1 connected to a DC power supply. In Figure 5B, the terminals of the two electrodes extending from the DC power supply are connected to the first conductor and the second conductor, respectively. The DC power supply in Figure 5B is turned on and a voltage is applied. Figure 5C shows composite 1 after application of voltage. As shown in Figure 5C, the first conductor and the second conductor are electrically connected via the adhesive, and the second conductor can be separated from composite 1.

[0098] In this embodiment, since the electrically peelable adhesive body has a conductive pattern layer, electrical peeling can be performed even when the adhesive body is attached to an insulator. Examples are shown in Figures 6A to 6C below. A composite (composite 2) can be formed by attaching an insulator to the first electrically peelable adhesive layer of the adhesive body and attaching a first conductor to the second electrically peelable adhesive layer. An example of the composite is shown in Figure 6A. Figure 6B shows composite 2 connected to a DC power supply. In Figure 6B, the terminals of the two electrodes extending from the DC power supply are connected to the conductive pattern layer and the first conductor, respectively. The DC power supply in Figure 6B is started and a voltage is applied. Figure 6C shows composite 2 after application. As shown in Figure 6C, electricity is passed between the conductive pattern layer of the adhesive body and the first conductor, allowing the first conductor to be separated from composite 2.

[0099] Although the adhesive body of this embodiment can achieve electrical peeling at low voltage, its use at high voltage is not prohibited. The range of applied voltage can be selected from the upper limit of 690V, 650V, 600V, 550V, 500V, 450V, 400V, 350V, 300V, 250V, 230V, 200V, 180V, 150V, 130V, 125V, 120V, 110V, 100V, 90V, 80V, 70V, 60V, 50V, 40V, and 30V, and the lower limit of 0.5V, 1V, 2V, 3V, 4V, 5V, 6V, 7V, 8V, 9V, and 10V. Among these, it is preferable to operate at a voltage of 1 V or more and 100 V or less, more preferably 1 V or more and 50 V or less, and even more preferably 5 V or more and 30 V or less.

[0100] The voltage application time is not particularly limited as long as it can cause electrical peeling in the composite, but is preferably from 1 second to 600 seconds, more preferably from 1 second to 300 seconds, more preferably from 1 second to 180 seconds, and even more preferably from 1 second to 90 seconds. [Example]

[0101] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples at all.

[0102] [Electrical peeling test using electrically peelable adhesive] Three types of electro-releasable pressure-sensitive adhesive materials were prepared, and composites were formed by combining them with a conductor and an insulator, and an electro-releasable pressure-sensitive adhesive composition used in the composites was prepared as follows.

[0103] (Electrically releasing adhesive composition A) 1. Preparation of acrylic polymer A monomer mixture consisting of 90 parts by weight of n-butyl acrylate (Mitsubishi Chemical Corporation), 6 parts by weight of methyl methacrylate (Mitsubishi Chemical Corporation), 3 parts by weight of acrylic acid (Mitsubishi Chemical Corporation), and 1 part by weight of 2-hydroxyethyl methacrylate (Nippon Shokubai Co., Ltd.) was mixed with 0.2 parts by weight of azobisisobutyronitrile (AIBN, Junsei Chemical Co., Ltd.) as a polymerization initiator and 150 parts by weight of ethyl acetate, and the mixture was heated to 85°C and polymerized for 5 hours to obtain an acrylic adhesive. The resulting acrylic adhesive contained 40% by weight of acrylic polymer (weight-average molecular weight approximately 680,000) and had a viscosity of 6,000 mPa·s.

[0104] 2. Preparation of Electrically Releasable Pressure Sensitive Adhesive Composition To 100 parts by weight of the above acrylic pressure-sensitive adhesive (including 40 parts by weight of acrylic polymer), 2 parts by weight of Takenate (registered trademark) D-101E (Mitsui Chemicals, Inc.) as an isocyanate crosslinking agent, 14 parts by weight of Elexcel (registered trademark) AS-110 (EMI-FSI: Dai-ichi Kogyo Seiyaku Co., Ltd.) as an ionic liquid, and 3.5 parts by weight of dimethyl tetraglycol (Nippon Nyukazai Co., Ltd.: molecular weight approximately 220) as a migration promoter were added, and the mixture was stirred with a dissolver at room temperature for 10 minutes and allowed to stand to degas, to obtain electro-peelable pressure-sensitive adhesive composition A (composition A).

[0105] (Electro-Releasable Adhesive Body 1: Example) Composition A was applied to a silicone-treated polyethylene terephthalate film (hereinafter also referred to as a release film) to a thickness of 35 μm, and dried at 100° C. for 5 minutes. A polyester nonwoven fabric [Milife (registered trademark) TY0503FE (ENEOS Techno Materials Corporation): basis weight 8.0 g / m] was attached to the composition-coated surface of the dried film. 2 A 40 μm thick film was attached to the release film. Similarly, Composition A was applied to a release film to a thickness of 35 μm, and the film was dried to prepare a film. This film was attached to the side of the nonwoven fabric that had not been attached with the film. The film was then left to stand at 40°C for 3 days.

[0106] A separate release film was prepared and silver paste (Dotite FA-345: Fujikura Chemical Co., Ltd.) was screen-printed onto it in a grid pattern. The grid line width was 0.2 mm, the grid (gap) shape was standardized to a square, and the gap size was 1.0 mm in both length and width. One release film from the nonwoven fabric to which Composition A had been attached was peeled off, and a release film with a grid formed on it was attached so that the grid surface faced the surface coated with Composition A to form a conductive pattern layer, thereby producing an electrically peelable pressure-sensitive adhesive body 1 (Adhesive Body 1). The thickness of Adhesive Body 1 excluding the film was 83 μm, and the thickness excluding the film and conductive pattern layer was 80 μm. A photograph of the conductive pattern layer of Adhesive Body 1 is shown in Figure 7.

[0107] (Electro-Releasable Adhesive 2: Example) Electroreleasable adhesive body 2 was produced in the same manner as electroreleasable adhesive body 1, except that the line width of the lattice was 0.6 mm.

[0108] (Electrically Peelable Adhesive Composition B) 1. Preparation of acrylic polymer The polymer used was the acrylic polymer prepared in the above-mentioned preparation of acrylic polymer.

[0109] 2. Preparation of Electrically Releasable Pressure Sensitive Adhesive Composition To 100 parts by weight of the above acrylic adhesive (including 40 parts by weight of acrylic polymer), 2 parts by weight of Takenate (registered trademark) D-101E (Mitsui Chemicals, Inc.) as an isocyanate crosslinking agent and 17.5 parts by weight of Elexcel (registered trademark) AS-110 (EMI-FSI: Dai-ichi Kogyo Seiyaku Co., Ltd.) as an ionic liquid were added, and the mixture was stirred with a dissolver at room temperature for 10 minutes and allowed to stand to degas, thereby obtaining electro-peeling adhesive composition B (composition B).

[0110] (Electro-Releasable Adhesive 3: Example) An electrically peelable pressure-sensitive adhesive body 3 (adhesive body 3) was produced in the same manner as the above-mentioned electrically peelable pressure-sensitive adhesive body A, except for using composition B instead of composition A. The film thickness excluding the film of adhesive body 1 was 83 μm, and the film thickness excluding the film and conductive pattern layer was 80 μm.

[0111] (Electro-Releasable Adhesive 4: Comparative Example) The ionic liquid is prepared by mixing a cation selected from the group consisting of imidazolium-based cations and (FSO2)2N - , (CF3SO2)2N - and BF4 - An electro-releasable adhesive substance 4 (adhesive substance 4) was produced in the same manner as electro-releasable adhesive substance 1, except that 1-hexylpyridinium bis(trifluoromethanesulfone) manufactured by Kanto Chemical Co., Ltd. was used, which was not a combination with an anion selected from the above.

[0112] (Electro-Releasable Adhesive 5: Comparative Example) Electrically peelable adhesive body 5 (adhesive body 5) was produced in the same manner as electrically peelable adhesive body 3, except that the ionic liquid was changed to 1-hexylpyridinium bis(trifluoromethanesulfone) manufactured by Kanto Chemical Co., Ltd. and the line width of the lattice was set to 0.6 mm.

[0113] (electrical peeling test) Several pieces of each of the adhesive bodies 1 to 5 were cut out to a size of 25 mm x 250 mm. The polyethylene terephthalate film of each cut adhesive body was peeled off, and an insulator was attached to the exposed first electrically releasable adhesive layer, and a conductor was attached to the exposed second electrically releasable adhesive layer to form a composite. The structure of this composite is shown in Figure 8A. The attached conductors and insulators, and their combinations, are listed in Table 1 below as Examples 1 to 6 and Comparative Examples 1 to 4. Six samples were prepared for each combination. The sizes of the attached conductors and insulators were as follows:

[0114] Al (aluminum foil): 30mm x 150mm SUS (stainless steel plate): 30mm x 150mm PET (polyethylene terephthalate film): 30mm x 150mm ABS (acrylonitrile-butadiene-styrene resin plate): 30mm x 150mm Glass (general silicate glass plate): 30mm x 150mm

[0115] Electrodes and a DC power supply were attached to the conductor and conductive pattern of each composite (Figure 8B). The voltage was adjusted using a transformer, and a voltage of 10 V was applied for 10 seconds. In this case, electro-detachment occurred at the surface where the conductor was in contact with the adhesive body, and the conductor separated from the adhesive body.

[0116] The adhesive strength of each composite was measured before and after voltage application. The measurements were performed using a Shimadzu Autograph (registered trademark) AGS-H, in accordance with JIS Z-0237 (2009), measuring the force (adhesive strength: N / 25 mm) required to peel the conductor from the adherend at an angle of 180° at a tensile speed of 300 mm / min. The average of three measurements for each composite combination was used as the measured value. The measurement results are shown in Table 1.

[0117] [Table 1]

[0118] Furthermore, among the composite combinations shown in Table 1, the power supply shown in Figure 8B was connected with the positive and negative polarities reversed, and a voltage of 30 V was applied for 30 seconds to cause electrical peeling. The results are shown in Table 2. In this case, electrical peeling occurs at the surface where the adhesive and insulator are in contact. For each composite before and after applying electricity, the force required to peel the insulator from the adherend at an angle of 180° at a pulling rate of 300 mm / min (adhesive strength: N / 25 mm) was measured, and the average of three measurements for each composite combination was used as the measured value.

[0119] [Table 2]

[0120] The reduction rates in Tables 1 and 2 were calculated based on the following formula. Decrease rate (%) = ([Adhesive strength before printing] - [Adhesive strength after application]) / [Adhesive strength before printing]

[0121] From Tables 1 and 2, it can be seen that in each of the composites of Examples 1 to 6, in which an insulator was used as the adherend, the adhesive strength can be significantly reduced by causing electrical peeling by applying a voltage. It can also be seen that the reduction in adhesive strength by applying a voltage can occur on either side of the composite. In contrast, when the type of ionic liquid was a cation selected from imidazolium-based cations and (FSO2)2N - , (CF3SO2)2N - and BF4 - It can also be seen that the adhesive strength did not decrease significantly in Comparative Examples 1 to 4, in which the combination was changed to one that was not selected from the group consisting of an ionic liquid, an anion, and an ionic liquid selected from the group consisting of an ionic liquid, an anion, an ionic liquid ... [Explanation of symbols]

[0122] 1 First conductor 2 Second conductor 10. Electrically peelable adhesive 11 First electrically releasable adhesive layer 12 Second electrically releasable adhesive layer 13 Base 14 Conductive pattern layer 15 void 20 Insulators 100 DC power supply

Claims

1. An electrically releasable adhesive body comprising a substrate, a first electrically releasable adhesive layer on a first surface of the substrate, and a second electrically releasable adhesive layer on a second surface of the substrate, the first and second electrically releasing adhesive layers each comprise an electrically releasing adhesive composition including an acrylic polymer and an ionic liquid; a conductive pattern layer having voids is formed on the surface of the first electrically releasing adhesive layer; the first electrically releasable pressure-sensitive adhesive layer is capable of adhering to an adherend via voids in the conductive pattern layer, The ionic liquid comprises a cation selected from imidazolium-based cations and (FSO 2 ) 2 N - , (CF 3 SO 2 ) 2 N - and BF 4 - and a salt with an anion selected from the content of the ionic liquid in the electrically peelable pressure-sensitive adhesive composition is 10 parts by weight or more and 90 parts by weight or less per 100 parts by weight of the acrylic polymer, the voids occupy an area of ​​25% or more and 70% or less of the surface of the first electrically releasing pressure-sensitive adhesive layer, The size of one of the gaps is 0.4 mm 2 Over 2.5mm 2 is as follows: the conductive pattern layer includes a metal-based conductive material, There are a plurality of the voids within 1 cm 2 of the adhesive body. Electrically peelable adhesive.

2. 2. The electropeelable pressure-sensitive adhesive body according to claim 1, wherein the conductive pattern layer comprises line portions having a grid shape, a linear shape, a wavy line shape, a curved line shape, or a combination thereof.

3. 3. The electrically peelable adhesive body according to claim 2, wherein the width of the line portions of the conductive pattern layer is 0.01 mm or more and 3 mm or less.

4. 2. The electroreleasable adhesive body according to claim 1, wherein the ionic liquid is 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide and / or 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide.

5. 2. The electrically peelable pressure-sensitive adhesive body according to claim 1, wherein the voids occupy an area of ​​30% to 70% of the surface of the first electrically peelable pressure-sensitive adhesive layer.

6. 2. The electropeelable adhesive body according to claim 1, wherein the conductive pattern layer has a thickness in the range of 1 μm to 50 μm.

7. 2. The electrically peelable pressure-sensitive adhesive body according to claim 1, wherein the conductive pattern layer contains 40% by weight or more of a metal-based conductive material.

8. The electrically peelable pressure-sensitive adhesive body according to claim 1 , wherein the conductive pattern layer is formed on a surface of the second electrically peelable pressure-sensitive adhesive layer.

9. 2. The electroreleasable adhesive body according to claim 1, wherein the thickness of the electroreleasable adhesive body is in the range of 10 μm to 300 μm.

10. The substrate has a basis weight of 10.0 g / m 2 2. The electrically peelable pressure-sensitive adhesive body according to claim 1, wherein the thickness is 10 μm or more and 50 μm or less.

11. 2. The electrically peelable pressure-sensitive adhesive body according to claim 1, wherein the content of the ionic liquid in the electrically peelable pressure-sensitive adhesive composition is 10 parts by weight or more and 50 parts by weight or less per 100 parts by weight of the acrylic polymer.

12. 2. The electrically peelable pressure-sensitive adhesive body according to claim 1, wherein the acrylic polymer comprises a copolymer of an alkyl (meth)acrylate having an alkyl group having 1 to 8 carbon atoms, a carboxyl group-containing acrylic monomer, and / or a hydroxyl group-containing acrylic monomer.

13. The electrically peelable adhesive body according to claim 1 , wherein the electrically peelable adhesive composition comprises a migration promoter.

14. The electroreleasable adhesive according to claim 13, wherein the migration promoter is an alkyl ether of polyethylene glycol.

15. An electrically peelable pressure-sensitive adhesive body comprising an electrically peelable pressure-sensitive adhesive layer made of an electrically peelable pressure-sensitive adhesive composition containing an acrylic polymer and an ionic liquid, and a conductive pattern layer having voids formed on the surface of the electrically peelable pressure-sensitive adhesive layer, the electrically releasing pressure-sensitive adhesive layer comprises an electrically releasing pressure-sensitive adhesive composition containing an acrylic polymer and an ionic liquid, the electrically peelable pressure-sensitive adhesive layer is capable of adhering to an adherend via voids in the conductive pattern layer, The ionic liquid comprises a cation selected from imidazolium-based cations and (FSO 2 ) 2 N - , (CF 3 SO 2 ) 2 N - and BF 4 - and a salt with an anion selected from the content of the ionic liquid in the electrically peelable pressure-sensitive adhesive composition is 10 parts by weight or more and 90 parts by weight or less per 100 parts by weight of the acrylic polymer, the voids occupy an area of ​​25% or more and 70% or less of the surface of the electrically releasable pressure-sensitive adhesive layer, The size of one of the gaps is 0.4 mm 2 Over 2.5mm 2 is as follows: the conductive pattern layer includes a metal-based conductive material, There are a plurality of the voids within 1 cm 2 of the adhesive body. Electrically peelable adhesive.

16. a step of contacting a substrate with an electrically releasing pressure-sensitive adhesive composition containing an acrylic polymer and an ionic liquid to form a first electrically releasing pressure-sensitive adhesive layer and a second electrically releasing pressure-sensitive adhesive layer; forming a conductive pattern layer on at least the first electrically releasing adhesive layer; Including, The ionic liquid comprises a cation selected from imidazolium-based cations and (FSO 2 ) 2 N - , (CF 3 SO 2 ) 2 N - and BF 4 - and a salt with an anion selected from the content of the ionic liquid in the electrically peelable pressure-sensitive adhesive composition is 10 parts by weight or more and 90 parts by weight or less per 100 parts by weight of the acrylic polymer, the conductive pattern layer has voids, the voids occupy an area of ​​25% or more and 70% or less of the surface of the electrically releasable pressure-sensitive adhesive layer, The size of one of the gaps is 0.4 mm 2 Over 2.5mm 2 is as follows: the conductive pattern layer includes a metal-based conductive material, There are a plurality of the voids within 1 cm 2 of the adhesive body. Method for producing an electrically peelable adhesive material.

17. The manufacturing method according to claim 16, wherein the conductive pattern layer is in a lattice shape, and the width of the line portions of the conductive pattern layer is 0.01 mm or more and 3 mm or less.

18. The method according to claim 16, further comprising the step of preparing the electrical release adhesive composition before the step of forming the first and second electrical release adhesive layers.

19. The method of claim 16, wherein the electrically releasing adhesive composition comprises a migration promoter.

20. A method for peeling an electro-peelable adhesive body, comprising attaching objects to both sides of the electro-peelable adhesive body according to any one of claims 1 to 15, and then applying a voltage to the electro-peelable adhesive body.

21. The peeling method according to claim 20, wherein at least one of the objects is an insulator, the electrically peelable adhesive layer is attached to the insulator so that the surface having the electrically peelable adhesive layer is in contact with the insulator, and then a voltage is applied to the electrically peelable adhesive, and the layer is a layer having the conductive pattern layer formed on its surface.

22. 21. The method according to claim 20, wherein the voltage is in the range of 1 V or more and 100 V or less.

23. 21. The method according to claim 20, wherein the voltage application time is in the range of 1 second to 600 seconds.

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