Electrically peelable adhesive composition, electrically peelable adhesive sheet, and method for using electrically peelable adhesive sheet

Abstract

Provided is an electrically peelable adhesive composition obtained by blending a base polymer (A), an ionic compound (B), and a rosin-containing diol (C). The electrically peelable adhesive composition can easily adjust adhesiveness by applying a voltage.

Description

Technical Field

[0001] The present invention relates to an electro-peelable adhesive composition, an electro-peelable adhesive sheet having an adhesive layer formed from the electro-peelable adhesive composition, and a method of using the electro-peelable adhesive sheet. Background Technology

[0002] As one of the characteristics of adhesive sheets, re-peelability is sometimes required in applications such as temporary fixing tape, surface protective film, masking tape for coating or decoration, and re-peelable sticky notes.

[0003] When re-peelable adhesive sheets are attached to a substrate, they are required to have an adhesive strength that prevents them from peeling off during transportation, storage, and processing. On the other hand, they are required to have re-peelability that allows them to be easily removed after their function has been completed.

[0004] Incidentally, among the adhesives used in such re-peelable adhesive sheets, there are known adhesives whose adhesive strength is reduced by applying voltage.

[0005] For example, Patent Document 1 discloses an electrostatic peeling composition, wherein the adhesive, which can be easily peeled off from the adhered object after use, contains an ionic liquid.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: WO2007 / 018239. Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] As mentioned above, there is a need for an electro-peelable adhesive composition whose adhesion can be easily adjusted by applying voltage.

[0011] Methods for solving problems

[0012] The present invention provides an electro-removable adhesive composition comprising a base polymer, an ionic compound and a rosin-containing diol, an electro-removable adhesive sheet having an adhesive layer formed from the electro-removable adhesive composition, and a method of using the electro-removable adhesive sheet.

[0013] As specific embodiments of the present invention, they are shown below [1] to

[14] .

[0014] [1] An electro-removable adhesive composition comprising a base polymer (A), an ionic compound (B), and a rosin-containing diol (C).

[0015] [2] According to the electro-removable adhesive composition described in [1] above, wherein the mixing ratio of component (B) is 1.0 parts by mass or more relative to component (A) which is 100 parts by mass in total.

[0016] [3] According to the electro-removable adhesive composition described in [1] or [2] above, wherein the mixing ratio of component (C) is 2.0 parts by mass or more relative to component (A) which is 100 parts by mass.

[0017] [4] The electro-removable adhesive composition according to any one of [1] to [3] above, wherein the mixing ratio of component (C) to component (B) [(C) / (B)] is 0.10 to 20.0 by mass.

[0018] [5] The electrostripping adhesive composition according to any one of [1] to [4] above, wherein a crosslinking agent (D) is further incorporated.

[0019] [6] The electro-removable adhesive composition according to any one of [1] to [5] above, wherein a compound (E) represented by the following general formula (e-1) is further incorporated:

[0020] [Chemistry 1]

[0021]

[0022] R 1 R is an alkylene group having 1 to 8 carbon atoms. 2 R is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a hydroxyl group. 3 It is an alkyl group having 1 to 12 hydrogen atoms or carbon atoms, where n is an integer greater than or equal to 1.

[0023] [7] The electro-removable adhesive composition according to any one of [1] to [6] above, wherein the ionic compound (B) contains one or more selected from alkali metal salt (B1) and ionic liquid (B3).

[0024] [8] The electro-removable adhesive composition according to any one of [1] to [7] above, wherein the content of the effective ingredient that is liquid at 25°C is 1 to 50% by mass relative to the total amount of the effective ingredient in the adhesive composition.

[0025] [9] An electro-removable adhesive sheet, wherein it has an adhesive layer formed from an electro-removable adhesive composition according to any one of [1] to [8] above.

[0026]

[10] The electrically peelable adhesive sheet according to [9] above, wherein it has a conductive substrate and the adhesive layer is on at least one surface side of the conductive substrate.

[0027]

[11] According to the above [9] or

[10] , the electrically peelable adhesive sheet is peeled off on the cathode side when a voltage is applied to the adhesive layer.

[0028]

[12] The electrically peelable adhesive sheet according to any one of [9] to

[11] above, wherein the following requirement (I) is satisfied:

[0029] • Requirement (I): The rate of decrease in adhesive force, calculated by the following formula (i), representing the change in adhesive force before and after applying a voltage of 10V for 60 seconds, is 50% or more.

[0030] Formula (i): [Adhesive force reduction rate (%)] = 100 - [Adhesive force after voltage application] / [Adhesive force before voltage application] × 100.

[0031]

[13] A method of using an electrically removable adhesive sheet, wherein the electrically removable adhesive sheet according to any one of [9] to

[12] above is adhered to a conductive substrate.

[0032]

[14] According to the method of using the electrically removable adhesive sheet described in

[13] above, after the electrically removable adhesive sheet is pasted onto a conductive substrate, a voltage is applied to the adhesive layer to peel it off from the substrate.

[0033] The effects of the invention

[0034] In a preferred embodiment of the present invention, the electrostripping adhesive composition has high adhesion before voltage is applied, but on the other hand, the adhesion can be easily reduced by applying voltage. Attached Figure Description

[0035] [ Figure 1 [A schematic cross-sectional view of the adhesive sheet showing an example of the structure of an electrically peelable adhesive sheet according to one aspect of the present invention.]

[0036] [ Figure 2 Regarding an electrically peelable adhesive sheet of one aspect of the present invention, different diagrams are shown: (a) the adhesive sheet before voltage is applied, and (b) the adhesive sheet after voltage is applied.

[0037] [ Figure 3 Regarding an electrically peelable adhesive sheet of one aspect of the present invention, different diagrams are shown: (a) the adhesive sheet before voltage is applied, and (b) the adhesive sheet after voltage is applied. Detailed Implementation

[0038] The numerical ranges described in this specification can be arbitrarily combined with the upper and lower limits. For example, if the numerical range is described as "preferably 20 to 120, more preferably 40 to 90", then the ranges of "20 to 90" and "40 to 120" are also included in the numerical range described in this specification. Furthermore, if the numerical range is described as "preferably 20 or more, more preferably 40 or more, and preferably 120 or less, more preferably 90 or less", then the ranges of "20 to 90" and "40 to 120" are also included in the numerical range described in this specification.

[0039] Furthermore, the numerical ranges described in this specification, such as "60 to 100", refer to the range of "60 or more and 100 or less".

[0040] In this specification, for example, "(meth)acrylate" is used as a term referring to both "acrylate" and "methacrylate", and so are other similar terms.

[0041] In addition, the “active ingredient” of an electro-removable adhesive composition refers to the components contained in the electro-removable adhesive composition, excluding water and diluents for organic solvents.

[0042] In this specification, the mass-average molecular weight (Mw) is a value converted from polystyrene determined by gel permeation chromatography (GPC), specifically a value determined based on the method described in the examples.

[0043] [Electro-removable adhesive composition]

[0044] The electro-removable adhesive composition of the present invention (hereinafter also simply referred to as the "adhesive composition") is made by blending a base polymer (A) (hereinafter also referred to as "component (A)"), an ionic compound (B) (hereinafter also referred to as "component (B)"), and a rosin-containing diol (C) (hereinafter also referred to as "component (C)").

[0045] It should be noted that, in this specification, for example, "an adhesive composition formed by blending components (A), (B), and (C)" means that components (A), (B), and (C) are used as raw materials for the adhesive composition. Therefore, for example, it also includes situations where component (B) ionizes into cations and anions in the adhesive composition.

[0046] In typical electro-peelable adhesive compositions, ionic compounds are incorporated into the base polymer, thereby imparting properties that reduce adhesion upon the application of an electric current. However, electro-peelable adhesive compositions incorporating ionic compounds exhibit insufficient adhesion compared to adhesive compositions without ionic compounds. Adhesive sheets having adhesive layers formed from such electro-peelable adhesive compositions particularly require improved adhesion to metal substrates such as stainless steel or aluminum sheets.

[0047] In conventional adhesive compositions, tackifiers are often added to improve adhesion. However, according to the inventors' research, in the case of an electrically exfoliable adhesive composition made by blending a base polymer and an ionic compound, depending on the type of tackifier, there are cases where the adhesive composition has poor compatibility with the ionic compound (especially an ionic liquid) and thus does not sufficiently improve adhesion before voltage is applied, or cases where the adhesive composition is difficult to reduce even when voltage is applied.

[0048] Therefore, the inventors conducted various studies and obtained the following insight: an adhesive composition formed by blending a rosin-containing diol as a tackifier with a base polymer and an ionic compound has high adhesiveness before voltage is applied, and on the other hand, has the property that the adhesiveness can be easily reduced by applying voltage. The adhesive composition of the present invention was made based on this insight.

[0049] It should be noted that, in one aspect of the present invention, the adhesive composition preferably also contains one or more adhesive compositions selected from crosslinking agent (D) and compound (E) represented by the above general formula (e-1), and more preferably an adhesive composition that also contains components (D) and (E) simultaneously.

[0050] Alternatively, the adhesive composition of one aspect of the present invention may also be an adhesive composition containing additives other than components (A) to (E).

[0051] In one aspect of the adhesive composition of the present invention, from the viewpoint of producing an adhesive composition that has high adhesion before voltage is applied and whose adhesion can be easily reduced by applying voltage, the total amount of components (A), (B), and (C) is preferably 65 to 100% by mass, more preferably 70 to 100% by mass, further preferably 80 to 100% by mass, even more preferably 85 to 100% by mass, and particularly preferably 90 to 100% by mass, relative to the total amount (100% by mass) of the effective components of the adhesive composition.

[0052] In one aspect of the adhesive composition of the present invention, from the same viewpoint as described above, the total amount of components (A), (B), (C), (D), and (E) blended relative to the total amount (100% by mass) of the effective components of the adhesive composition is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, further preferably 85 to 100% by mass, even more preferably 90 to 100% by mass, and particularly preferably 95 to 100% by mass.

[0053] In one aspect of the adhesive composition of the present invention, from the same viewpoint as described above, the content of the effective component (hereinafter also referred to as "liquid component") that is liquid at 25°C is preferably 1 to 50% by mass relative to the total amount (100% by mass) of the effective component in the adhesive composition, more preferably 3 to 40% by mass, further preferably 5 to 30% by mass, even more preferably 7 to 25% by mass, and particularly preferably 10 to 20% by mass.

[0054] It should be noted that adhesive compositions with a high proportion of liquid components may also exhibit insufficient adhesion. However, in one embodiment of the adhesive composition of the present invention, since a rosin-based diol (C) with good compatibility with the liquid component is incorporated, an adhesive composition with further improved adhesion can be prepared.

[0055] It should be noted that the above-mentioned "liquid components" are effective components that are liquid at 25°C, excluding solvents. Specifically, examples include ionic liquids (B3) used as component (B) and compounds (E) used as component (E).

[0056] The components contained in an adhesive composition according to one aspect of the present invention will be described below.

[0057] <(A) Ingredients: Basic Polymer>

[0058] As a base polymer (A) used in one aspect of the present invention, any polymer with adhesive properties may be used, such as acrylic polymers, urethane polymers, rubber polymers, olefin polymers, silicone polymers, and cured polymers having polymerizable functional groups in these polymers.

[0059] These basic polymers (A) can be used alone or in combination of two or more.

[0060] In addition, the base polymer (A) used in one embodiment of the present invention can be an emulsion polymer or a non-emulsion polymer.

[0061] From the viewpoint of producing an adhesive composition with high adhesion before voltage is applied, the mass-average molecular weight of the base polymer (A) used in one embodiment of the present invention is preferably 10,000 to 2,000,000, more preferably 20,000 to 1,800,000, and even more preferably 30,000 to 1,500,000.

[0062] It should be noted that, in this specification, the mass-average molecular weight is a value converted from polystyrene determined by gel permeation chromatography (GPC), specifically a value determined based on the method described in the examples.

[0063] From the viewpoint of producing an adhesive composition that has high adhesion before voltage is applied and whose adhesion can be easily reduced by applying voltage, the base polymer (A) used in one embodiment of the present invention preferably contains an acrylic polymer (A1).

[0064] Based on the above viewpoint, in an adhesive composition according to one aspect of the present invention, the proportion of acrylic polymer (A1) in component (A) relative to the total amount (100% by mass) of component (A) contained in the adhesive composition is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, even more preferably 70 to 100% by mass, further preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, and particularly preferably 95 to 100% by mass.

[0065] As an example of the acrylic polymer (A1) used in this invention, polymers having structural units (a1) derived from alkyl (meth)acrylates (hereinafter also referred to as "monomers (a1')") are listed. From the viewpoint of producing an adhesive composition that has high adhesion before voltage is applied and whose adhesion can be easily reduced by applying voltage, copolymers having structural units (a1) and having structural units (a2) derived from monomers containing functional groups (hereinafter also referred to as "monomers (a2')") are preferred.

[0066] When the acrylic polymer (A1) is a copolymer, there are no particular restrictions on the copolymerization form; random copolymers, block copolymers, and graft copolymers are all acceptable.

[0067] The acrylic polymer (A1) used in one embodiment of the present invention may be used alone or in combination with two or more.

[0068] From the viewpoint of producing an adhesive composition with high adhesion before voltage is applied, the mass-average molecular weight of the acrylic polymer (A1) is preferably 50,000 to 2,000,000, more preferably 100,000 to 1,500,000, further preferably 200,000 to 1,200,000, and even more preferably 300,000 to 1,000,000. In particular, from the viewpoint of producing an adhesive composition that can form an adhesive layer that can improve the adhesion before voltage is applied when stainless steel sheet is the adherend, it is even more preferably 350,000 to 750,000, even more preferably 400,000 to 700,000, and especially preferably 450,000 to 640,000.

[0069] In one embodiment of the invention, the acrylic polymer (A1) used may be a copolymer having structural units (a3) ​​derived from monomers other than monomers (a1') and (a2') (hereinafter also referred to as "monomer (a3')").

[0070] It should be noted that, in one embodiment of the present invention, the proportion of the acrylic polymer (A1) containing structural units (a1) and (a2) relative to the total amount (100% by mass) of the structural units of the acrylic polymer (A1) can be set to 55% by mass or more, 60% by mass or more, 65% by mass or more, 70% by mass or more, 75% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more. Alternatively, it can be set to 100% by mass or less, 99% by mass or less, 95% by mass or less, 90% by mass or less, or 85% by mass or less.

[0071] The monomers and structural units that constitute acrylic polymers (A1) are described below.

[0072] [Single unit (a1'), Structural unit (a1)]

[0073] The number of carbon atoms of the alkyl group in the monomer (a1') is preferably 1 to 30, more preferably 1 to 20, even more preferably 1 to 16, further preferably 1 to 12, even more preferably 1 to 8, and particularly preferably 4 to 8.

[0074] It should be noted that the alkyl group in the monomer (a1') can be either a straight-chain alkyl group or a branched-chain alkyl group.

[0075] Specific monomers (a1') include, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate ((n-propyl methacrylate, isopropyl methacrylate), butyl methacrylate ((n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate), pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, tridecyl methacrylate, stearyl methacrylate, etc.

[0076] These monomers (a1') can be used alone or in combination of two or more.

[0077] The monomer (a1') preferably contains at least an alkyl ester of (meth)acrylate having an alkyl group having 4 to 8 carbon atoms, more preferably contains at least one of (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, and (meth)acrylate, 2-ethylhexyl ester, and more preferably contains at least (meth)acrylate or (meth)acrylate, and even more preferably contains at least (meth)acrylate.

[0078] In one embodiment of the present invention, the acrylic polymer (A1) preferably has a structural unit (a1-1) derived from an alkyl (meth)acrylate having 4 to 8 carbon atoms as a structural unit (a1). Alternatively, it may have a structural unit (a1-2) derived from an alkyl (meth)acrylate having 1 to 3 carbon atoms in addition to the structural unit (a1-1).

[0079] In one embodiment of the present invention, the acrylic polymer (A1) used contains, relative to the total amount (100% by mass) of the structural units (a1) of the acrylic polymer (A1), the content of the structural units (a1-1) is preferably 40% by mass or more, more preferably 50% by mass or more, more preferably 55% by mass or more, further preferably 60% by mass or more, even more preferably 65% ​​by mass or more, particularly preferably 70% by mass or more, and may also be set to 100% by mass or less, 99% by mass or less, 98% by mass or less, 95% by mass or less, 90% by mass or less, 85% by mass or less, 80% by mass or less, or 76% by mass.

[0080] In one embodiment of the present invention, the proportion of the acrylic polymer (A1) containing structural unit (a1) relative to the total amount (100% by mass) of the structural units of the acrylic polymer (A1) is preferably 30% by mass or more, more preferably 40% by mass or more, further preferably 50% by mass or more, even more preferably 60% by mass or more, and particularly preferably 70% by mass or more, from the viewpoint of producing an adhesive composition that can further improve cohesion by ensuring the above-mentioned proportion of structural unit (a2). It is preferably 99.99% by mass or less, more preferably 99.90% by mass or less, further preferably 99.0% by mass or less, even more preferably 97.0% by mass or less, particularly preferably 96.0% by mass or less, and furthermore, it can be set to 95.0% by mass or less, 90.0% by mass or less, or 85.0% by mass or less.

[0081] [Single unit (a2'), Structural unit (a2)]

[0082] As monomers (a2'), examples include hydroxyl-containing monomers, carboxyl-containing monomers, and epoxy-containing monomers.

[0083] These monomers (a2') can be used alone or in combination of two or more.

[0084] Examples of hydroxyl-containing monomers include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, and other hydroxyalkyl methacrylates, as well as unsaturated alcohols such as vinyl alcohol and allyl alcohol.

[0085] It should be noted that the number of carbon atoms of the alkyl group in the (meth)acrylic acid hydroxyalkyl ester is preferably 1 to 10, more preferably 1 to 8, further preferably 1 to 6, and even more preferably 2 to 4. The alkyl group can be a straight-chain alkyl group or a branched-chain alkyl group.

[0086] Examples of carboxyl-containing monomers include (meth)acrylic acid, crotonic acid and other olefinic unsaturated monocarboxylic acids, fumaric acid, itaconic acid, maleic acid, citraconic acid and other olefinic unsaturated dicarboxylic acids, and (meth)acrylic acid 2-carboxyethyl ester.

[0087] Examples of epoxy-containing monomers include glycidyl methacrylate, β-methyl glycidyl methacrylate, methyl (3,4-epoxycyclohexyl) methacrylate, 3-epoxycyclo-2-hydroxypropyl methacrylate, glycidyl crotonate, and allyl glycidyl ether.

[0088] In one embodiment of the present invention, the acrylic polymer (A1) used is preferably a copolymer having structural units (a2) derived from hydroxyl-containing monomers as structural units (a2).

[0089] Based on the above viewpoint, in the acrylic polymer (A1) used in one aspect of the present invention, the proportion of the structural unit (a2-1) relative to the total amount (100% by mass) of the structural unit (a2) of the acrylic polymer (A1) is preferably 60-100% by mass, more preferably 70-100% by mass, further preferably 80-100% by mass, even more preferably 90-100% by mass, and particularly preferably 95-100% by mass.

[0090] In one embodiment of the present invention, the proportion of the acrylic polymer (A1) containing the structural unit (a2) relative to the total amount (100% by mass) of the structural units of the acrylic polymer (A1) is preferably 0.01% by mass or more, more preferably 0.10% by mass or more, further preferably 1.0% by mass or more, even more preferably 3.0% by mass or more, particularly preferably 4.0% by mass or more, and furthermore, may be set to 5.0% by mass or more, 7.0% by mass or more, 10.0% by mass or more, 12.0% by mass or more, or 15.0% by mass or more. In addition, from the viewpoint of ensuring the content of the structural unit (a1) to produce an adhesive composition with better adhesion before voltage application, it is preferably 60% by mass or less, more preferably 50% by mass or less, further preferably 40% by mass or less, even more preferably 30% by mass or less, and particularly preferably 25% by mass or less.

[0091] [Single unit (a3'), Structural unit (a3)]

[0092] There are no particular restrictions on monomers (a3') other than monomers (a1') and (a2'). Examples include olefins such as ethylene, propylene, and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; diene monomers such as butadiene, isoprene, and chloroprene; and styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, (meth)acrylamide, (meth)acrylonitrile, (meth)acryloylmorpholine, and N-vinylpyrrolidone.

[0093] These monomers (a3') can be used alone or in combination of two or more.

[0094] In one embodiment of the present invention, the proportion of the acrylic polymer (A1) containing the structural unit (a3) ​​relative to the total amount (100% by mass) of the structural units of the acrylic polymer (A1) can be set to 0% or more by mass, 1% or more by mass, 5% or more by mass, 10% or more by mass, or 15% by mass. Alternatively, it can be set to 45% or less by mass, 40% or less by mass, 35% or less by mass, 30% or less by mass, 25% or less by mass, 20% or less by mass, 15% or less by mass, 10% or less by mass, or 5% or less by mass.

[0095] In one aspect of the adhesive composition of the present invention, from the viewpoint of producing an adhesive composition that has high adhesion before voltage is applied and whose adhesion can be easily reduced by applying voltage, the amount (content) of component (A) relative to the total amount (100% by mass) of the effective components of the adhesive composition is preferably 25% by mass or more, more preferably 30% by mass or more, more preferably 35% by mass or more, further preferably 40% by mass or more, further preferably 45% by mass or more, even more preferably 50% by mass or more, particularly preferably 55% by mass or more, and preferably 98% by mass or less, more preferably 95% by mass or less, more preferably 90% by mass or less, further preferably 87% by mass or less, further preferably 85% by mass or less, even more preferably 80% by mass or less, particularly preferably 75% by mass or less, and furthermore, may be set to 70% by mass or less, 67% by mass or less, or 65% by mass or less.

[0096] <Ingredient (B): Ionic compound>

[0097] As one embodiment of the present invention, the ionic compound (B) used may be, for example, one or more selected from alkali metal salts (B1), organic quaternary ammonium salts (B2), and ionic liquids (B3).

[0098] In one embodiment of the present invention, the component (B) preferably contains one or more selected from alkali metal salts (B1) and ionic liquids (B3).

[0099] In addition, in one embodiment of the present invention, the component (B) preferably uses an alkali metal salt (B1) or an ionic liquid (B3) as the main component.

[0100] It should be noted that, in this specification, the term "main component" refers to the component with the highest content among the components constituting component (B).

[0101] Furthermore, adhesive compositions containing a large amount of liquid components such as ionic liquid (B3) also suffer from insufficient adhesion. However, in an adhesive composition according to one aspect of the present invention, since rosin diol (C) with good compatibility with ionic liquid (B3) is incorporated, an adhesive composition that further improves adhesion and can be easily reduced by applying voltage can be produced.

[0102] When the main component of component (B) is an alkali metal salt (B1), the content of component (B) other than the alkali metal salt (B1) can be less than 100 parts by mass, 0 to 90 parts by mass, 0 to 50 parts by mass, 0 to 30 parts by mass, 0 to 20 parts by mass, 0 to 10 parts by mass, 0 to 5 parts by mass, 0 to 1 part by mass, 0 to 0.1 parts by mass, 0 to 0.01 parts by mass, 0 to 0.001 parts by mass, or 0 to 0.0001 parts by mass relative to a total of 100 parts by mass of alkali metal salt (B1).

[0103] When the main component of component (B) is ionic liquid (B3), the content of component (B) other than ionic liquid (B3) can be less than 100 parts by mass, 0 to 90 parts by mass, 0 to 50 parts by mass, 0 to 30 parts by mass, 0 to 20 parts by mass, 0 to 10 parts by mass, 0 to 5 parts by mass, 0 to 1 part by mass, 0 to 0.1 parts by mass, 0 to 0.01 parts by mass, 0 to 0.001 parts by mass, or 0 to 0.0001 parts by mass, relative to a total of 100 parts by mass of ionic liquid (B3).

[0104] In one aspect of the adhesive composition of the present invention, from the viewpoint of producing an adhesive composition in which the adhesiveness can be easily reduced by applying voltage, the mixing ratio of component (B) relative to 100 parts by mass of component (A) is preferably 1.0 parts by mass or more, more preferably 3.0 parts by mass or more, more preferably 5.0 parts by mass or more, further preferably 7.0 parts by mass or more, even more preferably 9.0 parts by mass or more, particularly preferably 11.0 parts by mass or more, and furthermore, may be set to 13.0 parts by mass or more or 16.0 parts by mass or more. Furthermore, from the viewpoint of producing... From the viewpoint of an adhesive composition having high adhesion before voltage is applied, it is preferably 200 parts by weight or less, more preferably 180 parts by weight or less, even more preferably 160 parts by weight or less, further preferably 150 parts by weight or less, even more preferably 130 parts by weight or less, particularly preferably 120 parts by weight or less, and furthermore, it can be set to 100 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, or 30 parts by weight or less.

[0105] In one aspect of the adhesive composition of the present invention, from the viewpoint of producing an adhesive composition whose adhesiveness can be easily reduced by applying voltage, the amount (content) of component (B) relative to the total amount (100% by mass) of the effective components of the adhesive composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, more preferably 1.0% by mass or more, further preferably 3.0% by mass or more, even more preferably 5.0% by mass or more, particularly preferably 7.0% by mass or more. In addition, from the viewpoint of producing an adhesive composition with high adhesiveness before applying voltage, it is preferably 50% by mass or less, more preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 25% by mass or less, even more preferably 20% by mass or less, particularly preferably 15% by mass or less.

[0106] Composition (B1): Alkali metal salt

[0107] As one embodiment of the present invention, the alkali metal salt (B1) used can be any compound that is solid at room temperature (25°C) but ionizes into cations (alkali metal ions) and anions in a liquid.

[0108] Specific alkali metal salts (B1) include, for example, MCl, MBr, MI, MAlCl4, MAl2Cl7, MBF4, MPF6, MSCN, MClO4, MNO3, CH3COOM, and C9H. 19 COOM, CF3COOM, C3F7COOM, MCH3SO3, MCF3SO3, MC4F9SO3, MC2H5OSO3, MC6H 13 OSO3, MC8H 17 OSO3, M(CF3SO2)2N, M(C2F5SO2)2N, M(C3F7SO2)2N, M(C4F9SO2)2N, M(CF3SO2)3C, MAsF6, MSbF6, MNbF6, MTaF6, M(CN)2N, M(CF3SO2)(CF3CO)N, M(CH3)2PO4, M(C2H5)2PO4, MCH3(OC2H4)2OSO3, MC6H4(CH3)SO3, M(C2F5)3PF3, CH3CH(OH)COOM, M(FSO2)2N, etc. (where M is an alkali metal atom). M is preferably Li, Na, or K, more preferably Na or K, and even more preferably Na.

[0109] These alkali metal salts (B1) can be used alone or in combination of two or more.

[0110] In one embodiment of the invention, the alkali metal salt (B1) used as component (B) preferably contains an alkali metal salt (B11) represented by the following general formula (b-1).

[0111] [Chemical Formula 2]

[0112]

[0113] In the above equation (b-1), R F Each alkyl group is independently a fluorine atom or a fluoroalkyl group. The number of carbon atoms in the fluoroalkyl group is preferably 1 to 10, more preferably 1 to 8, further preferably 1 to 4, even more preferably 1 to 3, and particularly preferably 1 to 2. In this specification, "fluoroalkyl group" refers to a group in which at least one hydrogen atom of the alkyl group is replaced by a fluorine atom, and it can be straight-chain or branched.

[0114] In fluoroalkyl groups, perfluoroalkyl groups are preferred, in which all hydrogen atoms of the alkyl group are replaced with fluorine atoms. The preferred range of the number of carbon atoms in the perfluoroalkyl group is the same as the preferred range of the number of carbon atoms in the fluoroalkyl group described above.

[0115] In one embodiment of the invention, R F Preferably, it is a fluorine atom or a perfluoroalkyl group, more preferably a fluorine atom, -CF3, -C2F5, -C3F7 or -C4F9, and even more preferably a fluorine atom or -CF3.

[0116] M is an alkali metal atom (lithium atom (Li), sodium atom (Na), potassium atom (K), rubidium atom (Rb), cesium atom (Cs), francium atom (Fr)), preferably Li, Na or K, more preferably Na or K, and even more preferably Na.

[0117] Ingredient (B2): Organic quaternary ammonium salt

[0118] The organic quaternary ammonium salt (B2) used in one aspect of the present invention can be any compound that is solid at room temperature (25°C) and is represented by the following general formula (b-2).

[0119] It should be noted that organic quaternary ammonium salts (B2) can be used alone or in combination with two or more.

[0120] [Chemical Formula 3]

[0121]

[0122] In the above general formula (b-2), R 11 ~R 14 Each is an alkyl group having 1 to 4 carbon atoms. X is F, Cl, Br, I, ClO4, BF4, PF6, or [(R 15)4N]2SO4(R 15 Each is an alkyl group having 1 to 4 carbon atoms.

[0123] Specific examples of organic quaternary ammonium salts (B2) include ammonium bromide or ammonium chloride such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, and triethylmethyl; ammonium tetrafluoroborate such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, and triethylmethyl; ammonium hexafluorophosphate such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, and triethylmethyl; ammonium perchlorate such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, and triethylmethyl; and ammonium sulfate such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, and triethylmethyl.

[0124] Composition (B3): Ionic Liquid

[0125] The ionic liquid (B3) used in one aspect of the present invention can be any molten salt that is liquid at room temperature (25°C) and is a compound composed of an organic cation and an anion as its counter ion.

[0126] As organic cations constituting the ionic liquid (B3), examples include cations represented by any one of the following general formulas (b-3-i) to (b-3-viii). Among them, the organic cations constituting the ionic liquid (B3) are preferably cations represented by the following general formula (b-3-ii).

[0127] [Chemical Formula 4]

[0128]

[0129] In the above equations (b-3-i) to (b-3-iv), R a Each is independently an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 1 to 20 carbon atoms.

[0130] Furthermore, in the above equations (b-3-v) to (b-3-viii), R b Each is independently composed of hydrogen atoms, alkyl groups having 1 to 20 carbon atoms, and is represented by -(C2H4O). n -R c The group represented (n is an integer from 1 to 20, R) c It is an alkyl group (with 1 to 20 carbon atoms) or an amino group.

[0131] As an option, R a R b and R cExamples of the alkyl groups mentioned above include methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl, sec-butyl, tert-butyl), pentyl (n-pentyl, isopentyl, neopentyl), hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, octadecyl, etc.

[0132] The alkyl group can be a straight-chain alkyl group or a branched-chain alkyl group.

[0133] As an option, R a and R b Examples of the alkenyl groups mentioned above include ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, octadecenyl, etc.

[0134] The alkenyl group can be either a straight-chain alkyl group or a branched-chain alkyl group.

[0135] It should be noted that at least one hydrogen atom bonded to a carbon atom of a cation represented by any one of the above general formulas (b-3-i) to (b-3-ii) may be replaced by an alkyl group having 1 to 20 carbon atoms. Specifically, such an alkyl group is as described above.

[0136] As a cation represented by the above general formula (b-3-i) and obtained by replacing at least one hydrogen atom of the cation with the above alkyl group, cations represented by any one of the following formulas (b-3-i-1) to (b-3-i-11) can be listed as examples.

[0137] [Chemical Formula 5]

[0138]

[0139] As a cation represented by the above general formula (b-3-ii) and a cation obtained by replacing at least one hydrogen atom of the cation with the above alkyl group, examples include cations represented by any one of the following formulas (b-3-ii-1) to (b-3-ii-26), preferably cations represented by any one of the following formulas (b-3-ii-1) to (b-3-ii-15), more preferably cations represented by any one of the following formulas (b-3-ii-1) to (b-3-ii-3) and (b-3-ii-9) to (b-3-ii-10), further preferably cations represented by any one of the following formulas (b-3-ii-1) to (b-3-ii-3), and even more preferably cations represented by the following formula (b-3-ii-2).

[0140] [Chemical Formula 6]

[0141]

[0142] As a cation represented by the above general formula (b-3-iii), for example, cations represented by any one of the following formulas (b-3-iii-1) to (b-3-iii-6) can be listed.

[0143] [Chemical Formula 7]

[0144]

[0145] As a cation represented by the above general formula (b-3-iv), for example, cations represented by any one of the following formulas (b-3-iv-1) to (b-3-iv-6) can be listed.

[0146] [Chemical Formula 8]

[0147]

[0148] As a cation represented by any of the above general formulas (b-3-v) to (b-3-viii), for example, cations represented by any of the following formulas can be listed.

[0149] [Chemical Formula 9]

[0150]

[0151] Examples of anions that constitute ionic liquids (B3) include Cl. - ,Br - I - AlCl4 - Al2Cl7 - BF4 - PF6 - SCN - ClO4 - NO3 - CH3COO - CF3COO - CH3SO3 - CF3SO3 - C4F9SO3 - (CF3SO2)2N - (C2F5SO2)2N - (C3F7SO2)2N - (C4F9SO2)2N - (CF3SO2)3C - AsF6 - SbF6- NbF6 - TaF6 - (CN)2N - C4F9SO3 - (C2F5SO2)2N - C3F7COO - (CF3SO2)(CF3CO)N - C9H 19 COO - (CH3)2PO4 - (C2H5)2PO4 - CH3OSO3 - C2H5OSO3 - C4H9OSO3 - C6H 13 OSO3 - C8H 17 OSO3 - CH3(OC2H4)2OSO3 - C6H4(CH3)SO3 - (C2F5)3PF3 - CH3CH(OH)COO - (FSO2)2N - B(CN)4 - C(CN)3 - N(CN)2 - p-Toluenesulfonate anion, 2-(2-methoxyethyl)ethyl sulfate anion, etc.

[0152] The preferred anion for the ionic liquid (B3) used in one embodiment of the present invention is (CF3SO2)2N. - Or (FSO2)2N - .

[0153] <Ingredient (C): Rosin-containing diol>

[0154] As one embodiment of the present invention, the rosin-containing diol (C) used is any diol having a skeleton derived from rosin, such as the reactants of rosin and epoxides.

[0155] It should be noted that rosin-containing diols (C) can be used alone or in combination with two or more.

[0156] Rosin comprising rosin-containing diols (C) refers to the residual resin obtained from the resin oil of pine trees after distillation to remove essential oils and other volatile substances. This residual resin is typically a mixture containing resin acids, primarily abietic acid and its analogues, and small amounts of neutral components. Examples of such resin acids include abietic acid, dehydroabietic acid, dihydroabietic acid, tetrahydroabietic acid, diabietic acid, neoabietic acid, L-piperidine, hydrogenated rosin obtained by hydrogenating these compounds, and disproportionated rosin obtained by disproportionating them.

[0157] Examples of the aforementioned epoxy compounds include, for instance, non-cyclic aliphatic diglycidyl ethers such as ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether; and 2,2-bis(4-hydroxyphenyl)propane diglycidyl ether and bis(4-hydroxyphenyl)methane diglycidyl ether. Ethers, such as 1,1-bis(4-hydroxyphenyl)ethane diglycidyl ether, 2,2-bis(4-hydroxycyclohexyl)propane diglycidyl ether, 3,3',5,5'-tetramethyl-4,4'-dihydroxybiphenyl diglycidyl ether, 2,2'-bis(4-(β-hydroxypropoxy)phenyl)propane diglycidyl ether, and other aromatic or cyclic aliphatic diglycidyl ethers, as well as cyclic aliphatic cyclic ethylene oxides such as 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexyl carbamate and vinyl cyclohexene dioxide.

[0158] These epoxy compounds can be used alone or in combination of two or more.

[0159] In one embodiment of the present invention, the rosin-containing diol (C) used is preferably a compound having two rosin-derived skeletons and two hydroxyl groups in its molecule.

[0160] From the viewpoint of producing an adhesive composition that has high adhesion before voltage is applied and whose adhesion can be easily reduced by applying voltage, by making good compatibility with components (A) and (B), especially with component (B), the softening point of the rosin-containing diol (C) used in one aspect of the present invention is preferably 60°C or higher, more preferably 65°C or higher, further preferably 70°C or higher, even more preferably 75°C or higher, particularly preferably 80°C or higher, and preferably 160°C or lower, more preferably 150°C or lower, more preferably 140°C or lower, further preferably 130°C or lower, even more preferably 120°C or lower, even more preferably 110°C or lower, and particularly preferably 104°C or lower.

[0161] It should be noted that, in this instruction manual, the softening point refers to the value determined according to the ring and ball method specified in JIS K5902.

[0162] From the viewpoint of producing an adhesive composition that has high adhesion before voltage is applied, and whose adhesion can be easily reduced by applying voltage, by making good compatibility with components (A) and (B), especially with component (B), the acid value of the rosin-containing diol (C) used in one aspect of the present invention is preferably 0 to 10.0 mg KOH / g, more preferably 0 to 4.9 mg KOH / g, further preferably 0 to 1.9 mg KOH / g, even more preferably 0 to 1.4 mg KOH / g, and particularly preferably 0 to 1.1 mg KOH / g.

[0163] Furthermore, from the viewpoint of producing an adhesive composition that has high adhesion before voltage is applied and whose adhesion can be easily reduced by applying voltage by making good compatibility with components (A) and (B), especially with component (B), the hydroxyl value of the rosin-containing diol (C) used in one aspect of the present invention is preferably 30 mg KOH / g or more, more preferably 50 mg KOH / g or more, further preferably 70 mg KOH / g or more, even more preferably 80 mg KOH / g or more, particularly preferably 90 mg KOH / g or more, and preferably 300 mg KOH / g or less, more preferably 250 mg KOH / g or less, further preferably 200 mg KOH / g or less, even more preferably 180 mg KOH / g or less, and particularly preferably 150 mg KOH / g or less.

[0164] It should be noted that, in this specification, acid value and hydroxyl value refer to the values ​​determined by potentiometric titration as specified in JIS K0070.

[0165] In one aspect of the adhesive composition of the present invention, from the viewpoint of producing an adhesive composition in which the adhesiveness can be easily reduced by applying voltage, the mixing ratio of component (C) to component (A) in a total amount of 100 parts by mass is preferably 2.0 parts by mass or more, more preferably 5.0 parts by mass or more, more preferably 8.0 parts by mass or more, further preferably 12.0 parts by mass or more, even more preferably 18.0 parts by mass or more, particularly preferably 22.0 parts by mass or more, and furthermore, may be set to 25.0 parts by mass or more or 30.0 parts by mass or more. Furthermore, from the perspective of making... From the viewpoint of producing an adhesive composition with good compatibility with components (A) and (B), particularly with component (B), and having high adhesion before the application of voltage, it is preferably 300 parts by weight or less, more preferably 200 parts by weight or less, even more preferably 150 parts by weight or less, further preferably 130 parts by weight or less, even more preferably 120 parts by weight or less, particularly preferably 110 parts by weight or less, and furthermore, it can be set to 100 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, or 50 parts by weight or less.

[0166] In one aspect of the adhesive composition of the present invention, from the viewpoint of producing an adhesive composition whose adhesiveness can be easily reduced by applying voltage, the amount (content) of component (C) is preferably 0.2% by mass or more, more preferably 1.2% by mass or more, more preferably 3.0% by mass or more, more preferably 5.0% by mass or more, further preferably 7.0% by mass or more, further preferably 9.0% by mass or more, even more preferably 11.0% by mass or more, and particularly preferably 16.0% by mass or more, relative to the total amount (100% by mass) of the effective components of the adhesive composition. In addition, from the viewpoint of producing an adhesive composition with high adhesiveness before applying voltage by ensuring good compatibility with components (A) and (B) (especially with component (B)), it is preferably 60% by mass or less, more preferably 55% by mass or less, more preferably 50% by mass or less, further preferably 45% by mass or less, even more preferably 40% by mass or less, and particularly preferably 35% by mass or less. Furthermore, it can be set to 30% by mass or less, 27% by mass or less, or 25% by mass or less.

[0167] In one aspect of the adhesive composition of the present invention, from the viewpoint of producing an adhesive composition that has high adhesion before voltage is applied, and whose adhesion can be easily reduced by applying voltage, the mixing ratio of component (C) to component (B) [(C) / (B)] by mass is preferably 0.10 or more, more preferably 0.30 or more, more preferably 0.50 or more, further preferably 0.80 or more, further preferably 1.00 or more, even more preferably 1.20 or more, particularly preferably 1.50 or more, and preferably 20.0 or less, more preferably 15.0 or less, more preferably 10.0 or less, further preferably 8.0 or less, further preferably 6.0 or less, even more preferably 5.0 or less, and particularly preferably 4.0 or less.

[0168] <Other thickeners>

[0169] An adhesive composition of one aspect of the present invention may contain other tackifiers besides component (C) without impairing the effects of the present invention.

[0170] Other tackifiers include rosin resins other than component (C), hydrogenated rosin resins obtained by hydrogenating rosin resins other than component (C), terpene resins, terpene phenolic resins, aromatic modified terpene resins, hydrogenated terpene resins obtained by hydrogenating these terpene resins, C5 petroleum resins obtained by copolymerizing C5 fractions such as pentene, isoprene, piperine, and 1,3-pentadiene generated in the pyrolysis of naphtha, and hydrogenated petroleum resins of these C5 petroleum resins, and C9 petroleum resins obtained by copolymerizing C9 fractions such as indene, vinyltoluene, α-methylstyrene, and β-methylstyrene generated in the pyrolysis of naphtha, and hydrogenated petroleum resins of these C9 petroleum resins.

[0171] These other tackifiers can be used alone or in combination of two or more.

[0172] However, from the viewpoint of producing an adhesive composition that has high adhesion before voltage is applied, and whose adhesion can be easily reduced by applying voltage, it is preferable that the adhesive composition of one aspect of the present invention contains as little content as possible of other tackifiers besides component (C).

[0173] Relative to the total amount of component (C) contained in the above adhesive composition of 100 parts by mass, the content of other tackifiers other than component (C) is preferably less than 10 parts by mass, more preferably less than 5 parts by mass, further preferably less than 1 part by mass, even more preferably less than 0.1 parts by mass, and particularly preferably less than 0.01 parts by mass.

[0174] <Ingredient (D): Crosslinking agent>

[0175] One aspect of the adhesive composition of the present invention is preferably an adhesive composition that also incorporates a crosslinking agent (D). By incorporating a crosslinking agent (D), it is easier to formulate an adhesive composition that has high adhesion before voltage is applied, but whose adhesion can be easily reduced by applying voltage.

[0176] It should be noted that crosslinking agent (D) can be used alone or in combination with two or more types.

[0177] Crosslinking agents (D) used in one embodiment of the present invention include, for example, isocyanate-based crosslinking agents, epoxy-based crosslinking agents, imine-based crosslinking agents, metal chelate-based crosslinking agents, etc.

[0178] Examples of isocyanate-based crosslinking agents include toluene diisocyanate compounds such as 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, phenyl dimethyl diisocyanate compounds such as 1,3-phenylenedimethyl diisocyanate and 1,4-phenylenedimethyl diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, and lysine isocyanate.

[0179] It should be noted that trimers of these organic polyisocyanate compounds, as well as terminal isocyanate carbamate prepolymers obtained by reacting these organic polyisocyanate compounds with polyol compounds, can also be used.

[0180] Examples of epoxy crosslinking agents include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, 1,3-bis(N,N-diglycidylaminomethyl)toluene, and N,N,N',N'-tetraglycidyl-4,4-diaminodiphenylmethane.

[0181] Examples of imine-based crosslinking agents include N,N'-diphenylmethane-4,4'-bis(1-aziridinylcarboxamide), trimethylolpropane-tris(β-aziridinylpropionate), tetramethylolmethane-tris(β-aziridinylpropionate), and N,N'-toluene-2,4-bis(1-aziridinylcarboxamide)triethylene melamine.

[0182] Examples of metal chelate crosslinking agents include aluminum chelate compounds such as tri(ethylacetoacetyl)aluminum, ethylaluminum diisopropyl acetoacetate, and aluminum triacetylacetonate, which are coordination compounds of multivalent metals.

[0183] In one aspect of the adhesive composition of the present invention, from the viewpoint of making it easier to formulate an adhesive composition that has high adhesion before voltage is applied, and on the other hand, whose adhesion can be easily reduced by applying voltage, the blending ratio of component (D) to component (A) in a total amount of 100 parts by mass is preferably 0.001 to 10.0 parts by mass, more preferably 0.005 to 7.0 parts by mass, further preferably 0.010 to 5.0 parts by mass, even more preferably 0.050 to 2.0 parts by mass, and particularly preferably 0.100 to 1.0 parts by mass.

[0184] <Ingredient (E): Compound>

[0185] One aspect of the adhesive composition of the present invention is preferably an adhesive composition that also incorporates a compound (E) represented by the following general formula (e-1).

[0186] By incorporating compounds (E) with ether bonds, such as those represented by the following general formula (e-1), it is easier to formulate adhesive compositions whose adhesiveness can be easily reduced by applying voltage. Furthermore, adhesive compositions exhibiting high adhesiveness even before voltage is applied can be produced; in particular, adhesive layers formed from adhesive compositions containing compound (E) can exhibit high adhesion to aluminum plates before voltage is applied.

[0187] It should be noted that compound (E) can be used alone or in combination with two or more compounds.

[0188] [Chemical Formula 10]

[0189]

[0190] In the above general formula (e-1), R 1 It is an alkylene group having 1 to 8 carbon atoms (preferably 1 to 6, more preferably 1 to 4, and even more preferably 2 or 3).

[0191] R 2 It is an alkyl or hydroxyl group with 1 to 12 hydrogen atoms and carbon atoms (preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 3).

[0192] R 3 It is an alkyl group having 1 to 12 hydrogen atoms or carbon atoms (preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 3).

[0193] n is an integer greater than or equal to 1.

[0194] As an option, R 1Examples of the aforementioned alkylene groups include methylene (-CH2-), ethylene (-CH2CH2-), ethylidene (-CH(CH3)-), trimethylene (-CH2CH2CH2-), propylene (-CH(CH3)CH2-), propylene (-CHCH2(CH3)-), isopropylene (-C(CH3)2-), tetramethylene (-CH2CH2CH2CH2-), 1-methyltrimethylene (-CH(CH3)CH2CH2-), 2-methyltrimethylene (-CH2CH(CH3)CH2-), butylene (-C(CH3)2CH2-), and those using -(CH2) m - (m is an integer from 1 to 8) represents groups, etc.

[0195] Among them, R 1 Preferably, it is ethylene or propylene, more preferably ethylene.

[0196] As an option, R 2 and R 3 The alkyl groups mentioned above can include methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl, sec-butyl, tert-butyl), pentyl (n-pentyl, isopentyl, neopentyl), hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, etc.

[0197] The compound (E) used in one embodiment of the present invention is preferably R in the above general formula (e-1). 2 hydroxyl group, R 3 The polyalkylene glycol containing hydrogen atoms is more preferably polyethylene glycol or polypropylene glycol, and even more preferably polyethylene glycol.

[0198] The mass-average molecular weight (Mw) of the compound (E) used in one embodiment of the present invention is preferably 50 to 2,000, more preferably 90 to 1,000, even more preferably 130 to 500, and even more preferably 170 to 300.

[0199] In one aspect of the adhesive composition of the present invention, from the viewpoint of making it easier to formulate an adhesive composition whose adhesiveness can be easily reduced by applying voltage, and from the viewpoint of producing an adhesive composition that has high adhesiveness even before applying voltage, the blending ratio of component (E) to component (A) in a total amount of 100 parts by mass is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 25 parts by mass, further preferably 1.0 to 20 parts by mass, even more preferably 2.5 to 16 parts by mass, and particularly preferably 4.0 to 12.0 parts by mass.

[0200] <Other Additives>

[0201] One aspect of the adhesive composition of the present invention may be blended with or contain other additives besides components (A) to (E).

[0202] Other additives may be selected as appropriate, depending on the intended use of the adhesive sheet using the adhesive composition. Examples include compatibilizers, wetting agents, thickeners, defoamers, antioxidants, UV absorbers, softeners (plasticizers), fillers, rust inhibitors, pigments, dyes, etc.

[0203] As other additives, those used in typical adhesive compositions can be used.

[0204] In addition, each additive can be used alone or in combination of two or more.

[0205] The amount of each of these other additives is set appropriately according to the type of additive, and is preferably 0.01 to 50 parts by mass relative to 100 parts by mass of component (A), more preferably 0.05 to 40 parts by mass, even more preferably 0.1 to 30 parts by mass, and even more preferably 0.2 to 20 parts by mass.

[0206] From the viewpoint of improving operability by making it easier to apply to substrates such as those described later, the adhesive composition of one aspect of the present invention can be further diluted with an organic solvent to form a solution.

[0207] Examples of organic solvents include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, and isopropanol.

[0208] It should be noted that, regarding these organic solvents, the organic solvents used in the synthesis of component (A) can be used directly, or one or more organic solvents other than those used in the synthesis of component (A) can be added.

[0209] [Electro-peelable adhesive sheet]

[0210] The electrically removable adhesive sheet of the present invention (hereinafter also simply referred to as "adhesive sheet") has an adhesive layer formed from the electrically removable adhesive composition of the present invention described above.

[0211] The adhesive sheet of one aspect of the present invention is not particularly limited as long as it has the structure of the adhesive layer. For example, it may be an adhesive sheet with an adhesive layer on at least one side of the substrate, or it may be an adhesive sheet with the adhesive layer sandwiched between two release tabs.

[0212] Figure 1 This is a schematic cross-sectional view of an example of the structure of an electrically peelable adhesive sheet according to one aspect of the present invention.

[0213] As one aspect of the present invention, the specific structure of the adhesive sheet can be exemplified by, for example, the following: Figure 1 (a) shows an electrically peelable adhesive sheet 1a with an adhesive layer 3 on one surface of a substrate 2. Alternatively, it could be as shown... Figure 1 (b) shows a structure similar to an electrically peelable adhesive sheet 1b with an adhesive layer 3 and an adhesive layer 3' on each of the two surface sides of the substrate 2.

[0214] It should be noted that, in one embodiment of the adhesive sheet of the present invention, it can be as follows: Figure 1 As shown in (a) the electro-peelable adhesive sheet 1a, the structure in which the substrate 2 and the adhesive layer 3 are directly laminated can also be made into a structure with other layers between the substrate 2 and the adhesive layer 3. This is for Figure 1 The substrate 2 and adhesive layer 3, as well as the substrate 2 and adhesive layer 3' in the electrically peelable adhesive sheet 1b shown in (b) are the same.

[0215] Alternatively, the adhesive sheet of one embodiment of the present invention may also be... Figure 1 (c) shows a structure similar to the electrically releasable adhesive sheet 1c with a substrate, in which a release sheet 4 is further laminated on the adhesive surface of the adhesive layer 3. Similarly, in the electrically releasable adhesive sheet 1b, a structure in which release sheets are also laminated on the adhesive surfaces of the adhesive layer 3 and the adhesive layer 3', respectively.

[0216] Alternatively, the adhesive sheet of one embodiment of the present invention may also be... Figure 1 (d) shows a substrate-free electro-peelable adhesive sheet 1d with a structure in which the adhesive layer 3 is held between two peeling sheets 4 and 4' without using a substrate.

[0217] The raw materials of the release tabs 4 and 4' of the electro-peelable adhesive sheet 1d can be the same or different. Preferably, the release tabs 4 and 4' are made of different raw materials.

[0218] In addition, examples include electrically removable adhesive sheets, which have a structure in which a product with an adhesive layer on one side of a release sheet that has undergone a surface peeling treatment is rolled into a roll.

[0219] The adhesive layer, substrate, and release sheet of an adhesive sheet constituting one aspect of the present invention will now be described in detail.

[0220] <Adhesive layer>

[0221] The adhesive layer of the adhesive sheet of the present invention is formed by the electro-peelable adhesive composition of the present invention described above, and has the property that the adhesive force can be reduced by applying voltage.

[0222] The thickness of the adhesive layer in the adhesive sheet of one aspect of the present invention is appropriately adjusted according to the application, etc., preferably 0.5 to 120 μm, more preferably 1 to 100 μm, further preferably 3 to 80 μm, even more preferably 5 to 80 μm, and particularly preferably 10 to 60 μm.

[0223] If the thickness of the adhesive layer is 0.5 μm or more, it can exhibit good adhesion regardless of the type of substrate. On the other hand, if the thickness of the adhesive layer is 120 μm or less, it can become an electro-peelable adhesive sheet that has advantages in terms of productivity and good operability.

[0224] <Substrate>

[0225] From the viewpoint that a voltage is applied to the adhesive layer of the adhesive sheet when it is peeled off from the adhered object, the substrate of the adhesive sheet is preferably a conductive substrate.

[0226] That is, the adhesive sheet of one aspect of the present invention preferably has a structure having a conductive substrate and an adhesive layer on at least one surface side of the conductive substrate.

[0227] Materials that constitute a conductive substrate include, for example, aluminum, tin-doped indium oxide, copper, iron, silver, platinum, gold, and alloys of these metals.

[0228] Alternatively, a metal vapor deposit formed by vapor deposition of the aforementioned metal onto a resin film such as polyethylene terephthalate can be used as a substrate. When vapor deposition of metal onto a resin film, it is preferable to vapor deposit the metal on the surface of the resin film that is in contact with the adhesive layer.

[0229] The thickness of the substrate is preferably 5 to 300 μm, more preferably 10 to 150 μm, and even more preferably 20 to 100 μm.

[0230] <Peeling tablets>

[0231] In one aspect of the present invention, the adhesive sheet has a release sheet which is obtained by coating one or both sides of the release sheet substrate with a release agent.

[0232] Examples of substrates for release sheets include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; resin films such as polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyurethane, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer, polystyrene, polycarbonate, fluoropolymer, low-density polyethylene, linear low-density polyethylene, and triacetyl cellulose; or paper substrates such as coated paper, glassine paper, etc., and laminated paper made by laminating thermoplastic resins such as polyethylene onto these paper substrates.

[0233] As a release agent used in one aspect of the present invention, examples include rubber-based elastomers such as silicone resins, olefin resins, long-chain alkyl resins, alkyd resins, fluorinated resins, isoprene resins, or butadiene resins.

[0234] The thickness of the release sheet is not particularly limited, but is preferably 5 to 300 μm, more preferably 10 to 200 μm. It should be noted that when using a polyester film as the substrate for the release sheet, a thickness of 10 to 100 μm is preferred.

[0235] [Manufacturing method of electro-peelable adhesive sheet]

[0236] There are no particular limitations on the method for manufacturing the electrically releasable adhesive sheet of the present invention. It can be manufactured by coating the adhesive composition of one aspect of the present invention, prepared by the above method, onto the substrate or release sheet using a known coating method.

[0237] It should be noted that, from the viewpoint of achieving good coatability to the substrate or release sheet, the adhesive composition of one aspect of the present invention is preferably diluted with an organic solvent and used in solution form.

[0238] Methods for applying adhesive compositions to substrates or release sheets include, for example, spin coating, spray coating, doctor blade coating, knife coating, roller coating, scraper coating, die coating, gravure coating, etc.

[0239] Preferably, the adhesive composition is applied to a substrate or release sheet to form a coating film, followed by drying.

[0240] As for the drying conditions of the formed coating film, it is preferable to heat it at a temperature of 80°C to 150°C for 30 seconds to 5 minutes (preferably 40 seconds to 3 minutes, more preferably 45 seconds to 2 minutes) to dry it. After this drying process, an adhesive layer can be formed on the substrate or release sheet.

[0241] It should be noted that when a crosslinking agent is incorporated into the adhesive composition used to form the adhesive layer, an aging process of maintaining the mixture for a certain period of time (e.g., about 1 to 14 days) is preferred to complete the crosslinking. On the other hand, when no crosslinking agent is incorporated into the adhesive composition used, this aging process is not required.

[0242] The following are specific manufacturing methods for electrically peelable adhesive sheets, categorized by structure.

[0243] First, such as Figure 1(a) An electrically peelable adhesive sheet 1a having an adhesive layer 3 on one side of a substrate 2 can be made, for example, by directly coating a solution of the adhesive composition described above onto one surface of the substrate 2 to form the adhesive layer 3.

[0244] Alternatively, the adhesive layer 3 can be formed by directly applying a solution of the adhesive composition to the peeling surface of the release sheet, then bonding the adhesive layer 3 to the substrate 2, and removing the release sheet.

[0245] like Figure 1 (b) An electrically peelable adhesive sheet 1b having adhesive layers 3, 3' on both sides of the substrate 2 can be made, for example, by directly coating both sides of the substrate 2 with a solution of the adhesive composition described above to form adhesive layers 3, 3'.

[0246] Alternatively, a solution of the adhesive composition described above can be directly applied to the peeling surface of the release sheet to prepare two release sheets with adhesive layers formed thereon. The adhesive layers of each release sheet are then adhered to both sides of the substrate 2, and the release sheets are removed to complete the process.

[0247] like Figure 1 (c) An electrically releasable adhesive sheet 1c having an adhesive layer 3 and a release sheet 4 sequentially on a substrate 2, for example, can be manufactured by laminating the release sheet 4 onto the adhesive layer 3 of the electrically releasable adhesive sheet 1a obtained as described above.

[0248] Alternatively, the adhesive layer 3 can be formed by directly applying a solution of the adhesive composition to the peeling surface of the release sheet 4 to form an adhesive layer 3, and then bonding the adhesive layer 3 to the substrate 2.

[0249] like Figure 1 (d) An electrically removable adhesive sheet 1d having a structure in which the adhesive layer 3 is held between two release tabs 4 and 4' without using a substrate can be manufactured, for example, by directly applying a solution of the adhesive composition to the release treatment surface of the release tab 4 to form the adhesive layer 3, and then laminating another release tab 4' onto the surface of the adhesive layer 3.

[0250] It should be noted that, as mentioned above, it is preferable to adjust the peeling sheet 4 and the peeling sheet 4' to have different peeling forces.

[0251] [Characteristics of electrically peelable adhesive sheets]

[0252] In one embodiment of the adhesive sheet of the present invention, when a voltage is applied to the adhesive layer, it has the characteristic of peeling off on the cathode side. That is, peeling occurs between the adhesive surface of the adhesive layer connected to the cathode side and the adhered object or substrate bonded to the adhesive surface.

[0253] For example, such as Figure 2Consider, as in (a), the case where the electrically peelable adhesive sheet 1a of one aspect of the present invention needs to be peeled off from the adherend 11. Figure 2 In (a), the adhesive layer 3 is sandwiched between the adherend 11 and the substrate 2a. By connecting the anode terminal 51 of the voltage application device 50 to the substrate 2a and the cathode terminal 52 to the adherend 11, a voltage can be applied between the two surfaces of the adhesive layer 3.

[0254] It should be noted that when using Figure 1 In the case of substrate-free electro-peelable adhesive sheet 1d, as in (d), Figure 2 The structure of “substrate 2a” becomes another “adhesive”, and the adhesive layer 3 becomes a structure held between two adhesives. By connecting the anode terminal 51 and cathode terminal 52 of the voltage application device 50 to their respective adhesives, a voltage can be applied between the two surfaces of the adhesive layer 3.

[0255] If in Figure 2 If a voltage is applied in the state shown in (a), then as Figure 2 As shown in (b), the adhesive force is reduced between the adhesive surface 3a of the adhesive layer connected to the cathode side and the substrate 11 adhered to the adhesive surface 3a, making it easy to peel the electrically peelable adhesive sheet 1a off the substrate.

[0256] On the contrary, such as Figure 3 As in (a), in relation to Figure 2 Conversely, when the cathode terminal and the anode terminal are connected, the adhesive force between the adhesive surface 3a' of the adhesive layer connected to the cathode side and the substrate 2a bonded to the adhesive surface 3a of the adhesive layer connected to the cathode side decreases, and the substrate 2a is peeled off from the adhesive layer 3.

[0257] The applied voltage (applied voltage) is preferably 1 to 200V, more preferably 3 to 140V, and even more preferably 6 to 120V. The time for applying the voltage in this range (applied time) is preferably 1 to 180 seconds, more preferably 5 to 120 seconds, and even more preferably 10 to 90 seconds.

[0258] The adhesive force before applying voltage when the adhesive layer of the adhesive sheet of one aspect of the present invention is adhered to the aluminum plate, which is the adherend, is preferably 5.0 N / 25 mm or more, more preferably 6.0 N / 25 mm or more, more preferably 7.5 N / 25 mm or more, further preferably 8.0 N / 25 mm or more, even more preferably 8.5 N / 25 mm or more, even more preferably 9.0 N / 25 mm or more, particularly preferably 11.0 N / 25 mm or more, and furthermore, it can be set to 13.0 N / 25 mm or more, 15.0 N / 25 mm or more, 20.0 N / 25 mm or more, or 25.0 N / 25 mm or more.

[0259] Furthermore, when the adhesive layer of the adhesive sheet of one aspect of the present invention is adhered to an aluminum plate which is the object to be adhered, and a voltage of 10V is applied for 60 seconds, the adhesion force is preferably 0.20N / 25mm or less, more preferably 0.10N / 25mm or less, even more preferably 0.05N / 25mm or less, even more preferably 0.01N / 25mm or less, and particularly preferably 0.005N / 25mm or less.

[0260] When the adhesive layer of the adhesive sheet of one aspect of the present invention is adhered to a stainless steel plate as the adherend, the adhesion force before the application of voltage is preferably 3.0 N / 25 mm or more, more preferably 5.0 N / 25 mm or more, more preferably 10.0 N / 25 mm or more, even more preferably 12.0 N / 25 mm or more, even more preferably 15.0 N / 25 mm or more, and particularly preferably 20.0 N / 25 mm or more.

[0261] Furthermore, when the adhesive layer of the adhesive sheet of one aspect of the present invention is adhered to a stainless steel plate as the object to be adhered, and a voltage of 10V is applied for 60 seconds, the adhesion force is preferably 1.10N / 25mm or less, more preferably 0.80N / 25mm or less, more preferably 0.50N / 25mm or less, even more preferably 0.30N / 25mm or less, even more preferably 0.10N / 25mm or less, and particularly preferably 0.05N / 25mm or less.

[0262] When the adhesive sheet of one aspect of the present invention is adhered to the object, the rate of reduction of adhesive force calculated by the following formula (i) before and after the application of a voltage of 10V for 60 seconds is preferably 50% or more, more preferably 70% or more, further preferably 80% or more, even more preferably 90% or more, and particularly preferably 95% or more.

[0263] Formula (i): [Adhesive strength reduction rate (%)] = 100 - [Adhesive strength of the test piece after voltage application] / [Adhesive strength of the test piece before voltage application] × 100

[0264] It should be noted that the method for measuring the adhesive force of the adhesive sheet before and after applying voltage in this specification is based on the method described in the embodiments described later.

[0265] [Instructions for using electrically peelable adhesive sheets]

[0266] The electrically peelable adhesive sheet of the present invention can be adhered to any substrate.

[0267] There are no particular limitations on the substrate; it may or may not be conductive. However, from the viewpoint of easily applying voltage to the adhesive layer, a conductive substrate is preferred so that the substrate can directly serve as an electrode.

[0268] Examples of conductive adherends include aluminum, tin-doped indium oxide, copper, iron, silver, platinum, gold, and alloys of these metals (e.g., stainless steel).

[0269] In summary, the present invention also provides the usage method described in [i] below.

[0270] [i] A method of using an electrically removable adhesive sheet, wherein an electrically removable adhesive sheet of one aspect of the present invention is adhered to a conductive substrate.

[0271] In the method of use described above[i], after the above-mentioned electrically peelable adhesive sheet is attached to a conductive substrate, when peeling off the adhesive sheet, it can be peeled off from the substrate by applying a voltage to the adhesive layer.

[0272] It should be noted that when applying voltage to the adhesive layer, the bonding and voltage application are performed with the side of the adhesive sheet to be peeled off serving as the cathode.

[0273] Example

[0274] The present invention will now be described in more detail by providing examples. However, the present invention is not limited to any of the examples provided.

[0275] In addition, the values ​​of each physical property were determined by the method shown below.

[0276] (1) Mass-average molecular weight (Mw)

[0277] The determination was performed using a gel permeation chromatography apparatus (manufactured by TOSOH CORPORATION, product name "HLC-8020") under the following conditions, and the values ​​were converted to standard polystyrene.

[0278] (Measurement conditions)

[0279] • Column: A device consisting of “TSK guard column HXL-L”, “TSK gel G2500HXL”, “TSK gel G2000HXL” and “TSK gel G1000HXL” connected in sequence (all manufactured by TOSOH CORPORATION).

[0280] Column temperature: 40℃

[0281] • Developing solvent: Tetrahydrofuran

[0282] • Flow rate: 1.0 mL / min

[0283] (2) Softening point

[0284] Determined according to the ring and ball method specified in JIS K5902.

[0285] (3) Acid value, hydroxyl value

[0286] Determined by potentiometric titration as specified in JIS K0070.

[0287] Examples 1-8, Comparative Example 1

[0288] (1) Preparation of adhesive composition

[0289] The adhesive composition was prepared by adding each component according to the types and mixing amounts shown in Tables 1-2 and diluting it with ethyl acetate as a diluent.

[0290] The details of the components used in the preparation of the adhesive compositions of the examples and comparative examples described in Tables 1-2 are as follows.

[0291] <Ingredient (A): Basic Polymer>

[0292] • "Acrylic polymer 1": A copolymer having structural units derived from n-butyl acrylate (BA), methyl acrylate (MA), and 2-hydroxyethyl acrylate (2-HEA) (structural unit ratio: BA / MA / 2-HEA = 60 / 20 / 20 (mass ratio)), Mw = 600,000.

[0293] • "Acrylic polymer 2": A copolymer having structural units derived from n-butyl acrylate (BA), 4-acryloylmorpholine (ACMO) and 4-hydroxybutyl acrylate (4HBA) (structural unit ratio: BA / ACMO / 4HBA = 75 / 20 / 5 (mass ratio)), Mw = 800,000.

[0294] • "Acrylic polymer 3": A copolymer having structural units derived from n-butyl acrylate (BA), methyl acrylate (MA), and 2-hydroxyethyl acrylate (2-HEA) (structural unit ratio: BA / MA / 2-HEA = 75 / 20 / 5 (mass ratio)), Mw = 660,000.

[0295] • "Acrylic polymer 4": A copolymer having structural units derived from n-butyl acrylate (BA), methyl acrylate (MA), and 2-hydroxyethyl acrylate (2-HEA) (structural unit ratio: BA / MA / 2-HEA = 70 / 20 / 10 (mass ratio)), Mw = 800,000.

[0296] <Ingredient (B): Ionic compound>

[0297] • "Ionic liquid": Manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., product name "AS-210", 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imine salt, an ionic liquid that is liquid at room temperature (25°C).

[0298] <Ingredient (C): Rosin-containing diol>

[0299] • "Rosin-containing diol": Manufactured by Arakawa Chemical Industry Co., Ltd., product name "Pinecrystal D-6011", a rosin-containing diol, softening point = 84~99℃, acid value = less than 1mgKOH / g, hydroxyl value = 110~125mgKOH / g.

[0300] <Tackifier>

[0301] • "Terpene Phenolic Resin": Manufactured by Yasuhara Chemical Co., Ltd., product name "YS Polystar T-115", terpene phenolic resin, softening point = 115℃, hydroxyl value = 60mgKOH / g.

[0302] <Ingredient (D): Crosslinking agent>

[0303] • "Isocyanate-based crosslinking agent": Manufactured by TOSOH CORPORATION, product name "Coronate L", isocyanate-based crosslinking agent.

[0304] <Ingredient (E): Compound>

[0305] • "PEG": Polyethylene glycol with Mw = 200 (R in the above general formula (e-1) 1 Ethylene, R 2 hydroxyl group, R 3 It is a compound containing hydrogen atoms and is a liquid at room temperature (25°C).

[0306] [Table 1]

[0307]

[0308] [Table 2]

[0309]

[0310] The prepared adhesive composition was placed in a transparent container and its appearance was visually observed. The compatibility of the components constituting the adhesive composition was evaluated based on the following criteria.

[0311] <Compatibility Evaluation>

[0312] • A: No separation was found, confirming homogeneous compatibility.

[0313] • B: No separation was found. Although there were some slightly incompatible parts, they were confirmed to be uniformly compatible after stirring again.

[0314] •F: Discovery of separation.

[0315] The results are shown in Tables 3-4. The adhesive compositions prepared in Examples 1-7 showed good compatibility. On the other hand, the adhesive composition prepared in Comparative Example 1 was found to separate to the point that it was difficult to form an adhesive layer, so the production of the adhesive sheet was terminated without proceeding.

[0316] (2) Fabrication of adhesive sheet

[0317] On the release surface of the release sheet (manufactured by LINTEC Corporation, product name "SP-PET381031", thickness: 38μm, polyethylene terephthalate (PET) film with silicone release treatment), the adhesive composition prepared in the example is applied to form a coating film with a dry thickness of 50μm. The coating film is dried at 100°C for 2 minutes to form an adhesive layer on the release sheet.

[0318] Based on this, the exposed surface of the formed adhesive layer is adhered to the aluminum foil side of the PET film (manufactured by Asia-Alumi Co., Ltd., thickness: 23μm, a conductive substrate formed by sequentially stacking PET film, adhesive layer and aluminum foil) as the substrate, to create a conductive substrate with... Figure 1 The electrically peelable adhesive sheet 1c shown in (c) is an adhesive sheet with a substrate of the same structure.

[0319] Using the prepared adhesive sheet, the adhesive force of the test sheet before and after applying electricity was measured based on the following method, and the rate of reduction in adhesive force was calculated. The results are shown in Tables 3 and 4.

[0320] [Adhesion strength of the test piece before voltage application]

[0321] The prepared adhesive sheet with substrate was cut into 25mm×75mm pieces, and the resulting material was used as a test piece.

[0322] In an environment of 23°C and 50% RH (relative humidity), remove the release liner from the test piece and attach the exposed adhesive layer to the following aluminum or stainless steel plate as the substrate.

[0323] • Aluminum sheet: An aluminum sheet obtained by cutting PALTEK CORPORATION's product name "A105OP" into 75mm×70mm×1mm sizes.

[0324] • Stainless steel sheet: SUS304, 360 grit polished

[0325] It should be noted that when applying the adhesive, a 2kg roller is used to press it back and forth once to adhere it to the object. After application, the object is left to stand for 30 minutes at 23°C and 50% RH (relative humidity) and the resulting material is used as a sample for adhesive strength testing.

[0326] Then, at 23°C and 50% RH (relative humidity), using a tensile testing machine (manufactured by ORIENTEC CO.,LTD., product name "TENSILON"), the adhesive force of the test piece before voltage application was measured when peeling off the sample used for adhesive force testing at a peel speed of 300 mm / min and a peel angle of 180°. This adhesive force was measured on aluminum and stainless steel plates, respectively.

[0327] [Adhesion force of the test piece after applying voltage]

[0328] For the samples used in the above adhesive strength test, such as Figure 2 As shown in (a), using a voltage application device 50 (manufactured by Takasago Manufacturing Co., Ltd., product name "KH-100H"), the anode terminal 51 is connected to the substrate 2a of the aluminum foil, and the cathode terminal 52 is connected to the substrate 11, and a voltage of 10V is applied for 60 seconds.

[0329] After applying voltage, the sample was left to stand for 1 minute. Then, at 23°C and 50% RH (relative humidity), the adhesive strength of the test piece was measured using a tensile testing machine (manufactured by ORIENTEC CO.,LTD., trade name "TENSILON") at a peel speed of 300 mm / min and a peel angle of 180°. The measured value (unit: N / 25 mm) was taken as the adhesive strength of the test piece after applying voltage. This adhesive strength was measured on aluminum and stainless steel plates, respectively.

[0330] Based on this, the adhesive force reduction rate is calculated from the adhesive force values ​​of the test pieces before and after voltage application using the following formula.

[0331] • [Adhesive strength reduction rate (%)] = 100 - [Adhesive strength of the test piece after voltage application] / [Adhesive strength of the test piece before voltage application] × 100

[0332] It should be noted that a negative value for the rate of decrease in adhesive force indicates that the adhesive force is increased by applying voltage.

[0333] [Table 3]

[0334] Table 3

[0335]

[0336] [Table 4]

[0337] Table 4

[0338]

[0339] As shown in Tables 3-4, the adhesive sheets prepared in Examples 1-8 all exhibited the following results regardless of whether the adhered object was an aluminum plate or a stainless steel plate: high adhesive strength before voltage was applied, and reduced adhesive strength upon application of voltage.

[0340] Symbol Explanation

[0341] 1a, 1b, 1c, 1d Electrically peelable adhesive sheets,

[0342] 2.2a Substrate

[0343] 3' Adhesive layer,

[0344] 3a, 3a' Adhesive surfaces

[0345] 4' Peeling plate,

[0346] 11. Adhesive material,

[0347] 50 Voltage application device,

[0348] 51 Anode terminal,

[0349] 52 Cathode terminal.

Claims

1. An electro-removable adhesive composition comprising a base polymer (A) including an acrylic polymer (A1), an ionic compound (B), and a rosin-containing diol (C), wherein... The ionic compound (B) contains one or more elements selected from alkali metal salts (B1), organic quaternary ammonium salts (B2), and ionic liquids (B3). The amount of component (A) is 25% by mass or more relative to the total amount of the active ingredients in the adhesive composition. The blending ratio of component (B) is 11.0 parts by mass or more and 30 parts by mass or less, relative to a total of 100 parts by mass of component (A). The blending ratio of component (C) is 5.0 parts by mass or more and 110 parts by mass or less, relative to a total of 100 parts by mass of component (A). The blending ratio of component (C) to component (B) [(C) / (B)] is 0.50 to 10.0 by mass.

2. The electro-removable adhesive composition according to claim 1, wherein, The blending ratio of component (B) is 16.0 parts by mass or more and 30 parts by mass or less, relative to a total of 100 parts by mass of component (A).

3. The electro-removable adhesive composition according to claim 1 or 2, wherein, The blending ratio of component (C) is more than 22.0 parts by mass and less than 80 parts by mass relative to a total of 100 parts by mass of component (A).

4. The electro-removable adhesive composition according to claim 1 or 2, wherein, The blending ratio of component (C) to component (B) [(C) / (B)] is 1.00 to 4.0 by mass.

5. The electro-removable adhesive composition according to claim 1 or 2, wherein, It also contains a cross-linking agent (D).

6. The electro-removable adhesive composition according to claim 1 or 2, wherein, It is also mixed with a compound (E) represented by the following general formula (e-1): [Chemical Formula 1] R 1 R is an alkylene group having 1 to 8 carbon atoms. 2 R is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a hydroxyl group. 3 It is an alkyl group with 1 to 12 hydrogen atoms or carbon atoms, where n is an integer greater than or equal to 1.

7. The electro-removable adhesive composition according to claim 1 or 2, wherein, The ionic compound (B) contains one or more of the following: an alkali metal salt (B1) and an ionic liquid (B3).

8. The electro-removable adhesive composition according to claim 1 or 2, wherein, The content of the active ingredient that is liquid at 25°C is 1 to 50% by mass relative to the total amount of the active ingredient in the adhesive composition.

9. Electrically peelable adhesive sheet, wherein, It has an adhesive layer formed from the electro-removable adhesive composition according to any one of claims 1 to 8.

10. The electrically peelable adhesive sheet according to claim 9, wherein, It has a conductive substrate, and the adhesive layer is present on at least one surface side of the conductive substrate.

11. The electrically peelable adhesive sheet according to claim 9 or 10, wherein, Peeling is performed on the cathode side when a voltage is applied to the adhesive layer.

12. The electrically peelable adhesive sheet according to claim 9 or 10, wherein, The following requirement (I) must be met: • Requirement (I): The rate of decrease in adhesive force, calculated by the following formula (i), representing the change in adhesive force before and after applying a voltage of 10V for 60 seconds, is 50% or more. Formula (i): [Adhesive force reduction rate (%)] = 100 - [Adhesive force after voltage application] / [Adhesive force before voltage application] × 100.

13. Instructions for use of electrically peelable adhesive sheets, including: The electrically peelable adhesive sheet according to any one of claims 9 to 12 is adhered to a conductive substrate.

14. The method of using the electro-peelable adhesive sheet according to claim 13, wherein, After the electrically peelable adhesive sheet is attached to a conductive substrate, a voltage is applied to the adhesive layer to peel it off from the substrate.

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