Method for disassembling bonded body

Abstract

The purpose of the present invention is to provide a method for disassembling a bonded body which has sufficient adhesion and, despite this, has excellent disassemblability when having become disused. This method is for disassembling a bonded body in which a substrate A and a substrate B are bonded to each other with an adhesive layer disposed therebetween comprising a cured object formed from an epoxy resin composition, wherein the adhesive layer contains an electroconductive material (D), the method including a step in which a voltage is applied to the bonded body. The adhesive layer especially preferably has a phase separation structure. In the voltage application step, the electric current is preferably a direct current or an alternating current of 20 kHz or less, and the voltage to be applied is preferably 24 V or less.

Description

Method for dismantling adhesive structures

[0001] The present invention relates to a method for disassembling adhesive bodies.

[0002] CO ２ The trend towards lighter automobiles and aircraft is progressing rapidly due to factors such as reduction in material consumption and improved fuel efficiency. This has led to a reduction in the number of spot welds and the use of fiber-reinforced resins and metals to further reduce weight, creating a strong demand for high-performance adhesives for structural materials used in these applications.

[0003] On the other hand, achieving high adhesive performance can lead to the creation of products that are difficult to recycle, limiting their dismantling and reuse after use. Given the growing environmental awareness in recent years, developing adhesives that maintain high performance while being easily removable after use is also crucial.

[0004] Against this backdrop, the development of easily disassembled adhesives has been actively pursued. Generally, the thermal melting of thermoplastic resins is often utilized, but research into the combined use of thermosetting resins with thermally expanding materials is also being actively conducted. Furthermore, a temporary bonding method has been reported in which UV-curing adhesives for temporary fixing during the processing of optical glass, wafers, etc., are peeled off by microwave irradiation (see, for example, Patent Document 1). In addition, a technology has been provided in which ionic liquids or metal halides are mixed into the adhesive, and when it is no longer needed, the adhesive strength is weakened by external stimulation to facilitate disassembly (see, for example, Patent Documents 2 and 3).

[0005] Japanese Patent Publication No. 2021-120428, International Publication No. 2007 / 018239, Japanese Patent Publication No. 2015-196791

[0006] However, conventional technologies such as those described in Patent Document 1 still have problems such as "not being able to obtain the effect of thermal expansion," "the adhesive being rigid and brittle and lacking flexibility," and "not being able to obtain sufficient adhesive strength as a result of prioritizing flexibility." Furthermore, challenges in dismantling operations include the need to prevent damage to the bonded materials and the need to minimize the environmental impact of decomposition products that may be generated from the adhesive layer during dismantling. The object of the present invention is to provide a method for dismantling an adhesive body that has sufficient adhesive properties while also being easy to dismantle when it is no longer needed.

[0007] As a result of intensive studies, the present inventors have found that by using an adhesive containing specific particles in an epoxy resin composition, the adhesive strength can be easily reduced by energization, and the above problems can be solved, thereby completing the invention.

[0008] That is, the present invention includes the following aspects. [1] A method for disassembling an adherent body in which a base material A and a base material B are joined via an adhesive layer made of a cured product of an epoxy resin composition, wherein the adhesive layer contains a conductive material (D), and the method for disassembling the adherent body includes a step of energizing the adherent body. [2] The method for disassembling an adherent body according to [1], wherein the adhesive layer has a phase-separated structure. [3] The phase-separated structure is obtained by containing an epoxy resin (A) having an epoxy equivalent of 500 to 10,000 g / equivalent represented by the following general formula (1) and an epoxy resin (B) having an epoxy equivalent of 100 to 300 g / equivalent. The method for disassembling an adherent body according to [2].

[0009] [In formula (1), each Ar is independently a structure having an unsubstituted or substituted aromatic ring, X is a structural unit represented by the following general formula (2), and Y is a structural unit represented by the following general formula (3).

[0010] [In formulas (2) and (3), Ar is the same as described above, and R １ and R ２ are each independently a hydrogen atom, a methyl group or an ethyl group, R' is a divalent hydrocarbon group having 2 to 12 carbon atoms, and R ３ and R ４ and R ７ and R ８ are each independently a hydroxyl group, a glycidyl ether group or a 2-methylglycidyl ether group, and R ５ and R ６ and R ９ and R １０ are each independently a hydrogen atom or a methyl group, n1 is an integer of 4 to 16, and n2 is an average value of repeating units of 2 to 30. ] R １１ and R １２Each of these is independently a glycidyl ether group or a 2-methylglycidyl ether group, R １３ , R １４ Each of these is independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group, R １５ , R １６is a hydrogen atom or a methyl group, m1, m2, p1, p2, q are repeating average values, m1 and m2 are each independently 0 to 25 and m1 + m2 ≥ 1, p1 and p2 are each independently 0 to 5, and q is 0.5 to 5. However, the bond between X represented by the general formula (2) and Y represented by the general formula (3) may be random or block, and the total number of each structural unit X and Y present in one molecule is m1 and m2, respectively. ] [4] The method for dismantling an adhesive according to [3], wherein the mass ratio (A):(B) of the epoxy resin (A) to the epoxy resin (B) is 90:10 to 10:90. [5] The method for dismantling an adhesive according to any one of [1] to [4], wherein the epoxy resin composition further comprises a heterocyclic aromatic compound (C) having a tertiary amino group. [6] The method for dismantling an adhesive according to [5], wherein the heterocyclic aromatic compound (C) having a tertiary amino group is at least one compound selected from the group consisting of imidazole compounds and pyridine compounds having a tertiary amino group. [7] The method for dismantling an adhesive according to [5] or [6], wherein the heterocyclic aromatic compound (C) having a tertiary amino group is at least one compound selected from the group consisting of imidazole, 1-methylimidazole, 2-ethyl-4-methylimidazole, and 4-dimethylaminopyridine. [8] The method for dismantling an adhesive according to any one of [5] to [7], wherein the proportion of the heterocyclic aromatic compound (C) having a tertiary amino group used is in the range of 2 to 20 parts by mass with respect to 100 parts by mass of the total of the epoxy resin (A) and the epoxy resin (B). [9] A method for dismantling an adhesive according to any one of [1] to [8], wherein the conductive material (D) is a single element of carbon, a metal, or a metal oxide, or a composite material containing one or more selected from the group consisting of carbon, a metal, and a metal oxide.

[10] A method for dismantling an adhesive according to any one of [1] to [9], wherein the average particle size of the conductive material (D) is in the range of 0.1 to 500 μm.

[11] A method for dismantling an adhesive according to any one of [1] to

[10] , wherein the proportion of the conductive material (D) used is in the range of 3 to 40 parts by mass with respect to 100 parts by mass of the total of the epoxy resin (A) and the epoxy resin (B).

[12] The method for dismantling an adhesive according to any one of [1] to

[11] , wherein the current in the energizing step is direct current or alternating current of 20 kHz or less.

[13] The method for dismantling an adhesive according to any one of [1] to

[12] , wherein the voltage applied in the energizing step is 24 V or less.

[14] The method for dismantling an adhesive according to any one of [1] to

[13] , wherein the epoxy resin composition further comprises a glycidyl ether group-containing compound (E), the glycidyl ether group-containing compound (E) is a compound in which a structural unit V having one or more glycidyl ether groups and a structural unit W different from the structural unit V are linked in a V-W-V manner, and the structural unit V and the structural unit W are linked by a reversible bond formed by a Diels-Alder reaction between a furan structure and a maleimide structure.

[15] The method for dismantling an adhesive according to

[14] , wherein the glycidyl ether group-containing compound (E) is a compound represented by the following general formula (4) and having a molecular weight of less than 1000.

[0011] [In equation (4), m3 is an integer between 1 and 4. Z １ This is given by the following equation (5), Z ３ The structure is one of the structures represented by the following formula (6), and each of the multiple structures in a single molecule may be the same or different.

[0012] [In formula (5), the aromatic ring may be unsubstituted or substituted, and * represents a bond point. G is a glycidyl group or a 2-methylglycidyl group.]

[0013] (In formula (6), R'' is independently a hydrogen atom, a methyl group, or an ethyl group, w1 is an integer from 1 to 30, w2 is the average value of the number of repetitions, from 0.5 to 8, w3 is the average value of the number of repetitions, from 0.5 to 6, and * represents a bond point.)

[16] The method for disassembling an adhesive according to any one of [1] to

[15] , wherein the epoxy resin composition further comprises a curing agent (F).

[17] The method for disassembling an adhesive according to any one of [3] to

[16] , wherein the phase separation structure consists of resin particles having an average particle diameter of 10 nm to 100 μm and a matrix surrounding them, the resin particles contain a cured product of the epoxy resin (A), and the matrix contains a cured product of the epoxy resin (B).

[18] The phase separation structure consists of resin particles having an average particle diameter of 10 nm to 100 μm and a matrix surrounding them, A method for disassembling an adhesive body according to any one of [3] to

[16] , wherein the resin particles contain a cured product of the epoxy resin (B), and the matrix contains a cured product of the epoxy resin (A).

[0014] According to the present invention, by using a specific adhesive, it is possible to provide a method for disassembling an adhesive that offers excellent adhesion and can be easily disassembled by applying electricity. Furthermore, when a specific epoxy resin composition is used as the adhesive, flexibility can be imparted to the adhesive layer.

[0015] Next, embodiments for carrying out the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be carried out in various improved, modified, and transformed forms based on the knowledge of those skilled in the art, without departing from the spirit of the invention, and all of these embodiments fall within the scope of the present invention.

[0016] <Method for Disassembling Adhesive> One embodiment of the present invention (this embodiment) is a method for disassembling an adhesive (sometimes simply referred to as "the method for disassembling this embodiment"), in which a substrate A and a substrate B are joined via an adhesive layer. The adhesive layer is a cured product of an epoxy resin composition and contains a conductive material (D). The method for disassembling this embodiment is a method for disassembling an adhesive, which includes the step of applying an electric current to the adhesive. It is preferable that the adhesive layer has a phase-separated structure, and it is preferable that the phase-separated structure is created by the curing of the epoxy resin composition.

[0017] As for the method of applying the current, for example, if both base material A and base material B are made of electrically conductive material, the positive terminal of a DC power supply is attached to one of the base materials, and the negative terminal is attached to the other base material, and the current is applied for a few seconds (for example, 10 seconds) to about 10 minutes. By applying this current, the two bonded base materials can be separated.

[0018] Furthermore, if either or both of the base material A and base material B are made of materials that cannot conduct electricity, the positive and negative terminals of a DC power supply may be attached directly to the adhesive layer in the bonded body at a certain distance, and electricity may be passed through the adhesive layer in the same manner as described above. In this case, the position where the positive and negative terminals are attached can be appropriately selected depending on the thickness of the adhesive layer, the proportion of the conductive material (D) used, or its type, but a method of passing electricity for a few seconds (for example, 10 seconds) to about 10 minutes is possible. If either base material A or base material B is made of a material that can conduct electricity, either the positive or negative terminal may be attached to a conductive base material, and the other may be attached to the adhesive layer. The current may be DC or AC. The applied voltage is preferably 24V or less, and particularly preferably 12V or less. The method of attaching the electrodes is the same even when AC is used. In the case of AC, the frequency is preferably 20kHz or less, and particularly preferably 100Hz or less.

[0019] <Adhesive> The adhesive comprises the base material A, the base material B, and the adhesive layer, wherein the base material A and the base material B are bonded together via the adhesive layer.

[0020] The materials of the substrate A and substrate B as the adherends are not particularly limited, and examples include inorganic materials such as metals and glass, organic materials such as plastics and wood, and fiber-reinforced resins such as CFRP, CFRTP, GFRP, and GFRTP. These materials may be used as appropriate depending on the application. Substrate A and substrate B may be the same material or different materials. In some applications, it is preferable for substrate A and substrate B to be made of different materials, as the adhesive layer can relieve stress, especially when it exhibits a phase separation structure. For example, even if the first substrate is a metal and / or metal oxide and the second substrate is a plastic layer, the adhesive strength is maintained due to the stress-relieving ability of the adhesive layer. Examples of the metal include copper, aluminum, gold, silver, iron, platinum, chromium, nickel, tin, titanium, zinc, various alloys, and composite materials thereof, and examples of the metal include single oxides and / or composite oxides of these metals. Since the adhesive layer exhibits particularly excellent adhesion to iron, copper, and aluminum, iron, copper, and aluminum are preferred as the metals.

[0021] The shapes of the base material A and the base material B may be any shape depending on the purpose. For example, they may be flat plates, sheets, or have a three-dimensional structure. They may also have curvature on all or part of their surface. The shapes of the base material A and the base material B may be any shape depending on the purpose.

[0022] The hardness, thickness, etc., of the base material A and the base material B are not particularly limited.

[0023] <Method for Forming the Adhesive> In the adhesive according to this embodiment, the adhesive is an epoxy resin composition containing a conductive material (D) as described above. In particular, it is preferable to use an epoxy resin composition capable of forming a phase separation structure as described later. The adhesive layer may be formed on the substrate A (or the substrate B) by direct coating or molding, or a pre-molded layer may be laminated. When direct coating is performed, there are no particular limitations on the coating method, and examples include spraying, spin coating, dipping, roll coating, blade coating, doctor roll, doctor blade, curtain coating, slit coating, screen printing, and inkjet. When direct molding is performed, examples include in-mold molding, insert molding, vacuum molding, extrusion lamination, and press molding. When laminating a molded composition, an uncured or semi-cured composition layer may be laminated and then cured, or a layer containing a fully cured composition may be laminated on the substrate A (or substrate B).

[0024] <Epoxy Resin Composition> As described above, the adhesive layer is made of a cured epoxy resin composition and contains a conductive material (D) internally, and optionally contains a heterocyclic aromatic compound (C) having a tertiary amino group. The epoxy resin composition according to this embodiment preferably further contains a curing agent (F). The epoxy resin composition according to this embodiment may further contain a glycidyl ether group-containing compound (E). The glycidyl ether group-containing compound (E) is a compound in which a structural unit V having one or more glycidyl ether groups and a structural unit W different from the structural unit V are linked in a V-W-V manner. The structural unit V and the structural unit W are linked by a reversible bond formed by a Diels-Alder reaction between a furan structure and a maleimide structure. The epoxy resin composition according to this embodiment may optionally contain a curing accelerator, other thermosetting resins or thermoplastic resins, non-halogenated flame retardants, fillers not belonging to the conductive material (D) according to this embodiment, or a dispersion medium. Furthermore, the total chlorine content of the epoxy resin composition according to this embodiment is preferably 0.001 to 5% by mass, more preferably 0.001 to 3% by mass, and even more preferably 0.01 to 2% by mass. The total chlorine content of the epoxy resin composition can be measured using the methods described in the examples below.

[0025] The epoxy resin contained in the epoxy resin composition is not particularly limited, and it is preferable to select it as appropriate depending on the type of substrate A and substrate B, the required adhesive strength, the thickness of the adhesive layer and the method of forming it, and the type of curing agent and curing accelerator used in combination.

[0026] Examples of the epoxy resins include liquid epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AD ​​type epoxy resin, polyhydroxybenzene type epoxy resin, polyhydroxynaphthalene type epoxy resin, biphenyl type epoxy resin, and tetramethylbiphenyl type epoxy resin; brominated epoxy resins such as brominated phenol novolac type epoxy resin; solid bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, and triphenylmethane type epoxy resin. Examples include tetraphenylethane type epoxy resins, dicyclopentadiene-phenol addition reaction type epoxy resins, phenol aralkyl type epoxy resins, phenylene ether type epoxy resins, naphthylene ether type epoxy resins, naphthol novolac type epoxy resins, naphthol aralkyl type epoxy resins, naphthol-phenol copolymer novolac type epoxy resins, naphthol-cresol copolymer novolac type epoxy resins, biphenyl-modified novolac type epoxy resins, etc. These can be used individually or in combination of two or more types, and it is preferable to select and use them according to the intended application and the physical properties of the cured product.

[0027] Among these, it is preferable to use liquid epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AD ​​type epoxy resin, polyhydroxybenzene type epoxy resin, polyhydroxynaphthalene type epoxy resin, biphenyl type epoxy resin, and tetramethylbiphenyl type epoxy resin. It is particularly preferable to use an epoxy resin with an epoxy equivalent of 100 to 300 g / equivalent, and most preferably an epoxy resin with an epoxy equivalent of 100 to 300 g / equivalent among bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AD ​​type epoxy resin. The epoxy equivalent is preferably 120 to 250 g / equivalent, more preferably 130 to 230 g / equivalent, and even more preferably 150 to 220 g / equivalent.

[0028] Furthermore, in terms of excellent adhesion, flexibility, and decomposability of the resulting epoxy resin cured product, the viscosity of the epoxy resin at 25°C is preferably 500 mPa·s to 30,000 mPa·s, more preferably 700 mPa·s to 25,000 mPa·s, and even more preferably 1,000 mPa·s to 20,000 mPa·s. The total chlorine content is preferably 0.001 to 20% by mass, more preferably 0.001 to 15% by mass, even more preferably 0.01 to 10% by mass, and even more preferably 0.01 to 5% by mass.

[0029] Among these, as mentioned above, the adhesive layer is preferably a cured product of an epoxy resin composition capable of forming a phase-separated structure. Epoxy resin compositions capable of spontaneously forming a phase-separated structure during the curing reaction and their cured products will be described in detail below.

[0030] (Epoxy resin composition capable of forming a phase-separated structure) The epoxy resin composition is made by combining an epoxy resin (A) represented by the above general formula (1) with an epoxy equivalent of 500 to 10,000 g / equivalent and an epoxy resin (B) with an epoxy equivalent of 100 to 300 g / equivalent, thereby enabling the formation of a phase-separated structure during the curing reaction.

[0031] [Epoxy resin (A)]

[0032] The epoxy resin (A) is an epoxy resin with an epoxy equivalent weight of 500 to 10,000 g / equivalent, represented by the following general formula (1).

[0033] [In formula (1), each Ar is independently a structure having an unsubstituted or substituted aromatic ring, X is a structural unit represented by the following general formula (2), and Y is a structural unit represented by the following general formula (3),

[0034] [In equations (2) and (3), Ar is the same as above, and R １ , R ２ Each of these is independently a hydrogen atom, a methyl group, or an ethyl group, and R' is a divalent hydrocarbon group having 2 to 12 carbon atoms, R ３ , R４ , R ７ , R ８ Each of these is independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group, R ５ , R ６ , R ９ , R １０ Each is independently a hydrogen atom or a methyl group, n1 is an integer from 4 to 16, and n2 is the average value of the repeating units from 2 to 30. ] R １１ , R １２ Each of these is independently a glycidyl ether group or a 2-methylglycidyl ether group, R １３ , R １４ Each of these is independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group, R １５ , R １６ is a hydrogen atom or a methyl group, m1, m2, p1, p2, and q are repeating average values, m1 and m2 are independently 0 to 25 and m1 + m2 ≥ 1, p1 and p2 are independently 0 to 5, and q is 0.5 to 5. However, the bond between X represented by the general formula (2) and Y represented by the general formula (3) may be random or blocky, and the total number of each structural unit X and Y present in one molecule is m1 and m2, respectively.

[0035] The above structure contains structural unit X represented by general formula (2) and / or structural unit Y represented by general formula (3), and the presence of alkylene chains or polyether chains in each structural unit makes it possible to exhibit high flexibility in the cured product. In particular, the flexibility derived from alkylene chains can follow the thermal expansion of the substrate when it is cured as an epoxy, and the polyether chains contribute to improving the processability and coating properties of the epoxy resin composition by making the epoxy resin (A) itself less viscous.

[0036] In the epoxy resin (A) described above, structural units X and Y may exist individually, or both structural units X and Y may be present in one molecule. In this case, X and Y may be bonded in a block bond or a random bond, and the total number of structural units X and Y contained in one molecule is m1 and m2, respectively.

[0037] The Ar in general formula (1) representing epoxy resin (A), the Ar in general formula (2) representing structural unit X, and the Ar in general formula (3) representing structural unit Y all have an unsubstituted or substituted aromatic ring. However, this aromatic ring is not particularly limited and examples include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, and fluorene ring.

[0038] Among these, the Ar is preferably one of the structures represented by the following structural formula (ar).

[0039] [The aromatic ring in formula (ar) may be unsubstituted or substituted, and * represents a bond point. The bond point is located on an aromatic ring, and if the structure contains multiple aromatic rings, it may be located on the same aromatic ring or on different aromatic rings.]

[0040] Furthermore, the following structure can also be given as Ar.

[0041] (In the formula, the aromatic ring may be unsubstituted or substituted, n ３ (=1 to 4, and * represents a connection point.)

[0042] The aromatic ring of Ar may be unsubstituted or substituted. If Ar has substituents, preferred substituents include alkyl groups, halogen atoms, glycidyl ether groups, and 2-methylglycidyl ether groups. Preferably, it is unsubstituted, or alkyl groups, glycidyl ether groups, or 2-methylglycidyl ether groups. It is preferable that there are two or fewer substituents per aromatic ring, more preferably one or fewer, and particularly preferable that it is unsubstituted.

[0043] The following structures of Ar are particularly preferred. * indicates a bonding point.

[0044]

[0045] Particularly preferred structures for substituted Ar include the following: * indicates a bond point.

[0046]

[0047] In the above formula, R is independently either a hydrogen atom or a methyl group.

[0048] In the structural unit X represented by the general formula (2) above, the repeating unit n1 is an integer from 4 to 16. When n1 is 4 or greater, the adhesive strength is improved and the deformation mode of the cured product becomes elastic deformation, which is preferable. When n1 is 16 or less, the decrease in crosslinking density can be suppressed, which is also preferable. With respect to n1, 4 to 15 is more preferable, and 6 to 12 is even more preferable.

[0049] Among these, R ３ , R ４ It is preferably a hydroxyl group, R ５ , R ６ It is preferable that it is a hydrogen atom.

[0050] In the structural unit Y represented by the general formula (3) above, n2 is the average value of the repeating units and is between 2 and 30. This range is preferable because it provides a good balance between the viscosity of the epoxy resin (A) and the crosslinking density of the resulting cured product. More preferably, n2 is between 2 and 25, and even more preferably between 4 and 20.

[0051] In the structural unit Y represented by the general formula (3) above, R' is a divalent hydrocarbon group having 2 to 12 carbon atoms. Within this range, the adhesive strength is improved and the deformation mode of the cured product can be elastic deformation. It is preferable that R' is a divalent hydrocarbon group having 2 to 6 carbon atoms.

[0052] The aforementioned divalent hydrocarbon group is not particularly limited and can include linear or branched alkylene groups, alkenylene groups, alkylylene groups, cycloalkylene groups, arylene groups, aralkylene groups (divalent groups having an alkylene group and an arylene group), etc.

[0053] Examples of alkylene groups include methylene, ethylene, propylene, butylene, pentylene, hexylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene. Examples of alkenylene groups include vinylene, 1-methylvinylene, propenylene, butenylene, and pentenylene. Examples of alkylylene groups include ethynylene, propynylene, butynylene, pentynylene, and hexynylene. Examples of cycloalkylene groups include cyclopropylene, cyclobutylene, cyclopentylene, and cyclohexylene. Examples of arylene groups include phenylene, torylene, xylylene, and naphthylene.

[0054] Among these, from the viewpoint of ease of obtaining raw materials, viscosity of the resulting epoxy resin (A), and balance of adhesiveness and flexibility of the resulting cured product, the alkylene group is preferably an ethylene group, a propylene group, or a tetramethylene group.

[0055] In the structural unit Y represented by the general formula (3) above, R ７ , R ８ Each of these is independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group, R ９ , R １０ Each of these is independently a hydrogen atom or a methyl group. ７ , R ８ It is preferably a hydroxyl group, R ９ , R １０ It is preferable that it is a hydrogen atom.

[0056] As described above, the epoxy resin (A) used in this embodiment is represented by the general formula (1). In the general formula (1), m1 and m2 are the average values ​​of the repeating structural units X and Y, respectively, and are independently between 0 and 25, and m1 + m2 ≥ 1.

[0057] Furthermore, R in the general formula (1) １１ , R １２ Each of these is independently a glycidyl ether group or a 2-methylglycidyl ether group, R １３ , R １４ Each of these is independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group, R １５ , R １６ Each is independently a hydrogen atom or a methyl group, p1, p2, and q are the average values ​​of the repeating values, p1 and p2 are independently 0 to 5, and q is 0.5 to 5. Among these, R １１ , R １２ It is preferable that R is a glycidyl ether group. １３ , R １４ It is preferably a hydroxyl group, R １５ , R １６ It is preferable that the atom is a hydrogen atom. Furthermore, it is preferable that p1 and p2 are 0 to 2, and that q is 0.5 to 2.

[0058] Furthermore, the epoxy equivalent of the epoxy resin (A) used in this embodiment is 500 to 10,000 g / equivalent. Within this range, the resulting cured product has excellent adhesion, flexibility, and decomposability. Taking into account ease of handling, it is preferable that the epoxy equivalent be in the range of 600 to 8,000 g / equivalent, more preferably in the range of 800 to 5,000 g / equivalent, and even more preferably in the range of 800 to 4,000 g / equivalent.

[0059] Among the epoxy resins (A) in this embodiment, one example of a resin having both structural unit X and structural unit Y in a single molecule is the resin with the following structural formula.

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072] In the above structural formulas (A-1) to (A-12), ran represents a random bond, G is a glycidyl group or a 2-methylglycidyl group, R' represents a divalent hydrocarbon group having 2 to 12 carbon atoms, n11 is an integer from 4 to 16, n21 is the average value of the repeating units from 2 to 30, m11, m21, p11, p21, and q11 are the average values ​​of the repeats, m11 and m21 are independently from 0.5 to 25, p11 and p21 are independently from 0 to 5, and q11 is from 0.5 to 5. However, each repeating unit present within a repeating unit may be the same or different.

[0073] Among the above structural formulas, it is preferable to use those represented by structural formulas (A-1), (A-2), (A-3), (A-5), (A-7), (A-8), and (A-9) from the viewpoint of having excellent adhesion, flexibility, and decomposability of the resulting epoxy resin cured product.

[0074] Among the epoxy resins (A) mentioned above, an example of an epoxy resin having the aforementioned structural unit X is a resin represented by the following structural formula.

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087] In the above structural formulas (A-13) to (A-24), G is a glycidyl group or a 2-methylglycidyl group, n11 is an integer from 4 to 16, m11, p11, p21, and q11 are the average values ​​of the repeats, m11 is from 0.5 to 25, p11 and p21 are independently from 0 to 5, and q11 is from 0.5 to 5. However, each repeating unit present within a repeating unit may be the same or different.

[0088] Among the above structural formulas, it is preferable to use those represented by structural formulas (A-13), (A-14), (A-15), (A-17), (A-19), (A-20), and (A-21) because they offer excellent adhesion, flexibility, and decomposability of the resulting epoxy resin cured product.

[0089] Among the epoxy resins (A) mentioned above, an example of an epoxy resin having the aforementioned structural unit Y is a resin represented by the following structural formula.

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] In the above structural formulas (A-25) to (A-36), G is a glycidyl group or a 2-methylglycidyl group, R' is a divalent hydrocarbon group having 2 to 12 carbon atoms, n21 is the average value of the repeating units and is between 2 and 30, m21, p11, p21, and q11 are the average values ​​of the repeats, m21 is between 0.5 and 25, p11 and p21 are independently between 0 and 5, and q11 is between 0.5 and 5. However, each repeating unit present within a repeating unit may be the same or different.

[0103] Among the above structural formulas, it is preferable to use those represented by structural formulas (A-25), (A-26), (A-27), (A-29), (A-31), (A-32), and (A-33) because they offer excellent adhesion, flexibility, and decomposability of the resulting epoxy resin cured product.

[0104] <Method for producing epoxy resin (A)> The method for producing the epoxy resin (A) is not particularly limited, but a method of reacting a diglycidyl ether of a dihydroxy compound having an alkylene chain and / or a polyether chain (a1), an aromatic hydroxy compound (a2), and an epihalohydrin (a3) ​​is preferred because the raw materials are readily available and the reaction is easy. The epoxy resin may be produced by reacting all of the reaction raw materials at once, or the resin may be produced by reacting the reaction raw materials sequentially. The method of reacting the reaction raw materials sequentially is preferred because the resulting epoxy resin cured product has excellent adhesion, flexibility, and decomposability.

[0105] One method for sequentially reacting the reaction raw materials is to react a diglycidyl etherified product (a1) of a dihydroxy compound having an alkylene chain and a polyether chain with an aromatic hydroxy compound (a2) in a molar ratio (a1) / (a2) within the range of 1 / 1.01 to 1 / 5.0 to obtain a hydroxy compound (a12) [corresponding to a precursor or intermediate of epoxy resin (A)], and then react it with an epihalohydrin (a3). The "molar ratio (a1) / (a2)" is the molar ratio of the epoxy group of the diglycidyl etherified product (a1) to the phenolic hydroxyl group (hydroxyl group bonded to an aromatic ring) of the aromatic hydroxyl compound (a2).

[0106] Furthermore, in terms of excellent adhesion, flexibility, and decomposability of the resulting epoxy resin cured product, the viscosity of the epoxy resin (A) at 60°C is preferably 1,000 mPa·s to 1,000,000 mPa·s, more preferably 2,000 mPa·s to 700,000 mPa·s, and even more preferably 5,000 mPa·s to 500,000 mPa·s. The total chlorine content is preferably 0.001 to 20% by mass, more preferably 0.001 to 15% by mass, and even more preferably 0.01 to 10% by mass. The epoxy equivalent, viscosity, and total chlorine content of the epoxy resin (A) are measured by the method described in the examples below.

[0107] The product obtained by the reaction of the diglycidyl etherified product (a1) of the dihydroxy compound having the alkylene chain and polyether chain with the aromatic hydroxy compound (a2) may contain unreacted aromatic hydroxy compound (a2). However, in the synthesis of the epoxy resin (A) used in this embodiment, it may be subjected to the reaction with the epihalohydrin (a3) ​​in the next step as is, or the unreacted aromatic hydroxy compound (a2) may be removed. However, from the viewpoint of balancing the toughness and flexibility of the cured product obtained from the epoxy resin composition according to this embodiment, which includes the resulting epoxy resin (A), it is preferable that the amount of unreacted aromatic hydroxy compound (a2) in the hydroxy compound subjected to the next step is within the range of 0.1 to 30% by mass.

[0108] The method for removing the unreacted aromatic hydroxy compound (a2) is not particularly limited and can be carried out according to various methods. For example, column chromatography separation using differences in polarity, distillation fractionation using differences in boiling points, and alkaline aqueous extraction using differences in solubility in alkaline water are examples. Among these, alkaline aqueous extraction is preferred in terms of yield, etc., because it does not involve thermal degradation. In this case, the organic solvent used to dissolve the target product is preferably one that does not mix with water, such as toluene, methyl isobutyl ketone, or butyl acetate, and methyl isobutyl ketone is particularly preferred from the viewpoint of solubility with the target product.

[0109] The diglycidyl etherified product (a1) of the dihydroxy compound having an alkylene chain and a polyether chain is not particularly limited as long as it is a glycidyl etherified product of the "dihydroxy compound having an alkylene chain and a polyether chain". The reaction conditions for the glycidyl etherification reaction of the "dihydroxy compound having an alkylene chain and a polyether chain" are the same as the reaction conditions for the glycidyl etherification reaction of the hydroxy compound (a12) using, for example, the epihalohydrin (a3) ​​described later.

[0110] Examples of the diglycidyl ethers (a1) of the dihydroxy compounds having alkylene chains and polyether chains include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,9-nonanediol diglycidyl ether, 1,11-undecanediol diglycidyl ether, 1,12-dodecanediol diglycidyl ether, and 1,13- Examples include lidecanediol diglycidyl ether, 1,14-tetradecanediol diglycidyl ether, 1,15-pentadecanediol diglycidyl ether, 1,16-hexadecanediol diglycidyl ether, 2-methyl-1,11-undecanediol diglycidyl ether, 3-methyl-1,11-undecanediol diglycidyl ether, and 2,6,10-trimethyl-1,11-undecanediol diglycidyl ether. Examples of diglycidyl ethers having a polyether chain include polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, polypentamethylene glycol diglycidyl ether, polyhexamethylene glycol diglycidyl ether, and polyheptamethylene glycol diglycidyl ether. These may contain organochlorine impurities generated during the glycidyl etherification of hydroxy compounds, and may contain organochlorine such as 1-chloromethyl-2-glycidyl ether (chloromethyl compound) represented by the structure shown below. These diglycidyl ethers may be used alone or in combination of two or more types. The total chlorine content in the diglycidyl etherified product (a1) of the dihydroxy compound having the alkylene chain and polyether chain is preferably 0.001 to 20% by mass, more preferably 0.001 to 15% by mass, and even more preferably 0.01 to 10% by mass.

[0111]

[0112] Among the above specific examples of diglycidyl ethers (a1) of dihydroxy compounds having alkylene chains and polyether chains, it is preferable to use 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,9-nonanediol diglycidyl ether, 1,12-dodecanediol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether, from the viewpoint of excellent adhesion, flexibility, and decomposition of the resulting cured product.

[0113] Furthermore, by simultaneously reacting the aforementioned diglycidyl ether having an alkylene chain and the diglycidyl ether having a polyether chain with the aromatic hydroxy compound (a2), a hydroxy compound having both structural unit X and structural unit Y is obtained. By further reacting this with the epihalohydrin (a3), an epoxy resin (A) having both structural unit X and structural unit Y is obtained.

[0114] The aromatic hydroxy compound (a2) is not particularly limited as long as it is a compound containing two or more phenolic hydroxyl groups, for example, dihydroxybenzenes such as hydroquinone, resorcinol, and catechol; trihydroxybenzenes such as pyrogallol, 1,2,4-trihydroxybenzene, and 1,3,5-trihydroxybenzene; triphenylmethane-type phenols such as 4,4',4"-trihydroxytriphenylmethane; 1,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and 1,4-dihydroxynaphthalene Dihydroxynaphthalenes such as 1,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, and 2,6-dihydroxynaphthalene; tetrafunctional phenols obtained by coupling reactions of dihydroxynaphthalenes, such as 1,1'-methylenebis-(2,7-naphthalenediol), 1,1'-binaphthalene-2,2',7,7'-tetraol, and 1,1'-oxybis-(2,7-naphthalenediol); bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, and 2,2-bis(3-methyl-4-hydroxyphenyl) Bisphenols such as roxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, and bis(4-hydroxyphenyl)sulfone; 2,2'-biphenol, 4,4'-biphenol, (1,1'-biphenyl)-3,4-diol, 3,3'-dimethyl-(1,1'-biphenyl)-4,4'-diol, 3-methyl-(1,1'-biphenyl)-4,4'-diol, and 3,3',5,5'-tetramethylbiphenyl-2,2'-diol Biphenols such as 3,3',5,5'-tetramethylbiphenyl-4,4'-diol, 5-methyl-(1,1'-biphenyl)-3,4'-diol, 3'-methyl-(1,1'-biphenyl)-3,4'-diol, and 4'-methyl-(1,1'-biphenyl)-3,4'-diol; alicyclic structure-containing phenols such as polyadditions of phenol and dicyclopentadiene, and polyadditions of phenol and terpene compounds; naphthols such as bis(2-hydroxy-1-naphthyl)methane and bis(2-hydroxy-1-naphthyl)propane;Examples of polyhydric phenolic compounds include so-called Zyloc-type phenolic resins, which are condensation reaction products of phenol and phenylene dimethyl chloride or biphenylene dimethyl chloride; phenol novolac resins, cresol novolac resins, dicyclopentadienephenol addition resins, phenol aralkyl resins (Zyloc resins), naphthol aralkyl resins, trimethylol methane resins, tetraphenylolethane resins, naphthol novolac resins, naphthol-phenol co-condensed novolac resins, naphthol-cresol co-condensed novolac resins, biphenyl-modified phenolic resins (polyhydric phenolic compounds in which the phenol nucleus is linked by a bismethylene group), biphenyl-modified naphthol resins (polyhydric naphthol compounds in which the phenol nucleus is linked by a bismethylene group), aminotriazine-modified phenolic resins (polyhydric phenolic compounds in which the phenol nucleus is linked by melamine, benzoguanamine, etc.), and alkoxy-group-containing aromatic ring-modified novolac resins (polyhydric phenolic compounds in which the phenol nucleus and alkoxy-group-containing aromatic ring are linked by formaldehyde). These compounds may be used individually or in combination of two or more. Furthermore, compounds in which the aromatic ring of each of the above compounds is substituted with a methyl group, a t-butyl group, or a halogen atom as a substituent are also included. Note that the alicyclic structure-containing phenols and the Zylok-type phenol resins may contain not only difunctional components but also trifunctional or higher components simultaneously. In this invention, they may be used as is, or the difunctional components may be isolated and used after purification using a column or other purification process.

[0115] Among these, bisphenols are preferred due to their excellent adhesion, flexibility, and decomposability of the resulting epoxy resin cured product, and bis(4-hydroxyphenyl)methane and 2,2-bis(4-hydroxyphenyl)propane are particularly preferred due to their remarkable toughness-imparting properties. Furthermore, when curability and heat resistance of the resulting epoxy resin cured product are important, dihydroxynaphthalenes are preferred, and 2,7-dihydroxynaphthalene is particularly preferred due to its remarkable rapid curing properties. Additionally, when moisture resistance of the resulting epoxy resin cured product is important, it is preferable to use compounds containing an alicyclic structure.

[0116] From the viewpoint of reaction efficiency, the reaction ratio of the diglycidyl etherified product (a1) of the dihydroxy compound having the alkylene chain and polyether chain to the aromatic hydroxy compound (a2) is preferably (a1) / (a2) of 1 / 1.01 to 1 / 5.0 (molar ratio), and more preferably (a1) / (a2) of 1 / 1.02 to 1 / 3.0 (molar ratio). The "molar ratio" refers to the molar ratio of the epoxy group to the phenolic hydroxyl group.

[0117] "Catalyst used in the reaction between (a1) and (a2)" The reaction between the diglycidyl etherified product (a1) of the dihydroxy compound having the alkylene chain and polyether chain and the aromatic hydroxy compound (a2) is preferably carried out in the presence of a catalyst. Various catalysts can be used, including, for example, alkali (earth) metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and calcium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate; phosphorus compounds such as triphenylphosphine; chlorides, bromides, and iodides such as 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30), 4-dimethylaminopyridine (DMAP), tetramethylammonium, tetraethylammonium, tetrabutylammonium, and benzyltributylammonium; quaternary ammonium salts such as chlorides, bromides, and iodides such as tetramethylphosphonium, tetraethylphosphonium, tetrabutylphosphonium, and benzyltributylphosphonium; tertiary amines such as triethylamine, N,N-dimethylbenzylamine (DMBA), 1,8-diazabicyclo[5.4.0]undecene, and 1,4-diazabicyclo[2.2.2]octane; and imidazoles such as 2-ethyl-4-methylimidazole and 2-phenylimidazole. These can be used individually or in combination of two or more. Among them, sodium hydroxide, potassium hydroxide, triphenylphosphine, and DMP-30 are preferred because the reaction proceeds rapidly and they have a high effect in reducing the amount of impurities in the by-products. The amount of these catalysts used is not particularly limited, but it is preferable to use 0.0001 to 0.1 moles per mole of phenolic hydroxyl group in the aromatic hydroxy compound (a2). The form of the catalyst is also not particularly limited and may be used in aqueous solution form or in solid form.

[0118] "Solvent used in the reaction between (a1) and (a2)" Furthermore, the reaction between the diglycidyl etherified product (a1) of the dihydroxy compound having an alkylene chain and a polyether chain and the aromatic hydroxy compound (a2) can be carried out without a solvent or in the presence of an organic solvent. Examples of organic solvents that can be used include alcohol-based solvents, glycol-based solvents, hydrocarbon-based solvents, ester-based solvents, ketone-based solvents, ether-based solvents, and dimethyl sulfoxide. Examples of alcohol-based solvents include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, isobutanol, octanol, n-propyl alcohol, and acetylacetone alcohol. Examples of glycol-based solvents include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate. Examples of ester-based solvents include methyl acetate, ethyl acetate, propyl acetate, and butyl acetate. Examples of ketone-based solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetylacetone. Examples of ether-based solvents include ethyl ether, butyl ether, methyl cellosolve, ethyl cellosolve, dioxane, furan, and tetrahydrofuran.

[0119] The amount of the organic solvent used is usually 50 to 300% by mass, and more preferably 100 to 250% by mass, relative to the total mass of the raw materials. The organic solvent may be used alone or in combination of two or more types. Solvent-free is preferred for rapid reaction, while dimethyl sulfoxide is preferred in terms of reducing impurities in the final product.

[0120] "Reaction conditions for (a1) and (a2)" The reaction temperature when (a1) and (a2) are carried out is usually 50 to 180°C, and the reaction time is usually 1 to 30 hours. A reaction temperature of 100 to 160°C is preferred in order to reduce impurities in the final product. If the resulting compound is highly discolored, antioxidants or reducing agents may be added to suppress this discoloration. Antioxidants are not particularly limited, but examples include hindered phenol compounds such as 2,6-dialkylphenol derivatives, divalent sulfur compounds, and phosphite ester compounds containing trivalent phosphorus atoms. Reducing agents are not particularly limited, but examples include hypophosphorous acid, phosphite, thiosulfite, sulfite, hydrosulfite, or salts thereof.

[0121] After the reaction between (a1) and (a2) is complete, the reaction mixture may be neutralized or washed with water until its pH value is 3 to 7, preferably 5 to 7. Neutralization and washing can be carried out according to conventional methods. For example, when a basic catalyst is used, acidic substances such as hydrochloric acid, sodium dihydrogen phosphate, p-toluenesulfonic acid, and oxalic acid can be used as neutralizing agents. After neutralization or washing, the solvent may be removed under reduced pressure and heating to concentrate the product and obtain the hydroxy compound.

[0122] By using a glycidyl ether having the alkylene chain and a glycidyl ether having the polyether chain in combination, a hydroxy compound having both structural unit X and structural unit Y can be obtained, but for example, a compound represented by the following structural formula is preferred.

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135] In each of the above structural formulas, ran represents a random bond, R' is a divalent hydrocarbon group having 2 to 12 carbon atoms, n11 is an integer from 4 to 16, n12 is the average value of the repeating units from 2 to 30, and m11 and m12 are the average values ​​of the repeats, independently from 0.5 to 25. However, each repeating unit within a repeating unit may be the same or different.

[0136] Furthermore, a hydroxy compound having the structural unit X can be obtained by using the glycidyl ether having the alkylene chain as a raw material, but for example, a compound represented by the following structural formula is preferred.

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144]

[0145]

[0146]

[0147]

[0148]

[0149] In each of the above structural formulas, n11 is an integer between 4 and 16, and m11 is the average value of the repeats, between 0.5 and 25.

[0150] Furthermore, a hydroxy compound having the structural unit Y can be obtained by using a glycidyl ether having the polyether chain as a raw material, but for example, a compound represented by the following structural formula is preferred.

[0151]

[0152]

[0153]

[0154]

[0155]

[0156]

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163] In each of the above structural formulas, R' is a divalent hydrocarbon group having 2 to 12 carbon atoms, n12 is the average value of the repeating units from 2 to 30, and m12 is the average value of the repeats from 0.5 to 25. However, each repeating unit within a repeating unit may be the same or different.

[0164] In the method for producing the epoxy resin (A), there are no particular limitations on the method for the glycidyl etherification reaction of the precursor (intermediate) hydroxy compound (a12) obtained above. Examples include reacting a phenolic hydroxyl group with the epihalohydrin (a3), or olefinizing the phenolic hydroxyl group and oxidizing the carbon-carbon double bond of the olefin with an oxidizing agent. Among these, the method using the epihalohydrin (a3) ​​is preferred because the raw materials are readily available and the reaction is easy.

[0165] One method using the epihalohydrin (a3) ​​is to add 0.3 to 100 moles of the epihalohydrin (a3) ​​to 1 mole of the phenolic hydroxyl groups of the hydroxy compound (a12) obtained above, and to this mixture, add 0.9 to 2 moles of basic catalyst per mole of phenolic hydroxyl groups of the hydroxy compound all at once or gradually, and react at a temperature of 20 to 120°C for 0.5 to 10 hours. The more the amount of epihalohydrin (a3) ​​added is in excess of the phenolic hydroxyl groups, the closer the resulting epoxy resin will be to the theoretical structure, and the formation of secondary hydroxyl groups generated by the reaction between unreacted phenolic hydroxyl groups and epoxy groups can be suppressed. From this viewpoint, it is preferable that the equivalent amount of epihalohydrin (a3) ​​added relative to the phenolic hydroxyl groups of the hydroxy compound is in the range of 2.5 to 100 equivalents. This basic catalyst may be used in solid form or as an aqueous solution. When using an aqueous solution, it may be added continuously, and water and epihalohydrin (a3) ​​may be continuously distilled from the reaction mixture under reduced pressure or atmospheric pressure, followed by liquid-liquid separation to remove the water and continuously returning the epihalohydrin (a3) ​​to the reaction mixture.

[0166] When carrying out industrial production, it is preferable to use all new epihalohydrin (a3) ​​in the first batch of epoxy resin production, but in subsequent batches, to use a combination of epihalohydrin (a3) ​​recovered from the crude reaction product and new epihalohydrin (a3) ​​equivalent to the amount consumed and lost in the reaction. At this time, the epihalohydrin (a3) ​​used is not particularly limited, but examples include epichlorohydrin and epibromohydrin. Among these, epichlorohydrin is preferred because it is readily available.

[0167] "Catalyst used in the reaction between precursor (a12) and (a3)" In the method for producing the epoxy resin (A), the catalyst used in the reaction between the precursor (intermediate) hydroxy compound (a12) obtained above and (a3) ​​is the catalyst described above in "Catalyst used in the reaction between (a1) and (a2)".

[0168] "Solvent used in the reaction between precursor (a12) and (a3)" In the method for producing the epoxy resin (A), the reaction of the precursor (intermediate) hydroxy compound (a12) obtained above with (a3) ​​can be carried out without a solvent or in the presence of an organic solvent. Examples of organic solvents used include the solvents described above in "Solvent used in the reaction between (a1) and (a2)".

[0169] After washing the reaction product of the precursor (a12) and the epihalohydrin (a3) ​​with water, the unreacted epihalohydrin (a3) ​​and organic solvent are removed by distillation under reduced pressure. In order to reduce the hydrolyzable halogen of the epoxy resin (A), the obtained epoxy resin may be dissolved again in an organic solvent such as toluene, methyl isobutyl ketone, or methyl ethyl ketone, and the reaction may be carried out further by adding an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. In this case, a phase transfer catalyst such as a quaternary ammonium salt or crown ether may be present to improve the reaction rate.

[0170] When using the aforementioned phase transfer catalyst, the amount used is preferably in the range of 0.1 to 3% by mass relative to the solid content of the reaction product. After the reaction is complete, the generated salt is removed by filtration, washing with water, etc., and then solvents such as toluene and methyl isobutyl ketone are removed by distillation under reduced heating pressure to obtain a high-purity epoxy resin.

[0171] [Epoxy resin (B)] The epoxy resin (B) may have an epoxy equivalent weight in the range of 100 to 300 g / equivalent, and its structure is not limited. Specific examples of epoxy resins and preferred ones (epoxy equivalent weight and viscosity) are the same as those included in the epoxy resin composition in the first embodiment of this application.

[0172] In this embodiment, there are no particular limitations on the ratio of epoxy resin (A) to epoxy resin (B) used. However, from the viewpoint of easily forming a phase separation structure in the cured product when the epoxy resin composition is cured, the mass ratio (A):(B) of epoxy resin (A) to epoxy resin (B) is 90:10 to 10:90, preferably 80:20 to 20:80, more preferably 70:30 to 30:70, and particularly preferably 60:40 to 40:60. Phase separation occurs in the cured product, forming a sea-island structure, which allows for both adhesion and stress relaxation of the cured product, resulting in high adhesive strength over a wide temperature range and reducing the molding shrinkage rate of the resin composition before and after heat curing.

[0173] The phase separation structure is formed spontaneously during the curing reaction based on the compatibility of epoxy resin (A) and epoxy resin (B), and generally consists of island phases of resin particles with an average particle size of 10 nm to 100 μm and a matrix (sea phase) surrounding them. At this time, whether the cured product forming the resin particles and the cured product forming the matrix are cured products of epoxy resins is determined by their mixing ratio, the type of curing agent, or the conditions of their effects. That is, the resin particles may contain cured product of epoxy resin (A) and the matrix may contain cured product of epoxy resin (B), or both may be possible.

[0174] The phase separation structure of the cured product can be observed using a microscope such as a scanning electron microscope (SEM) or an atomic force microscope (AFM). When a sea-island structure is formed, the particle size of the island phase can be measured. In this invention, the average particle size of the resin particles is determined by arbitrarily extracting 50 island phases from an island phase within a 200 μm × 260 μm field of view, measuring their particle sizes, and calculating the average. Furthermore, the relative hardness distribution of the sea phase and island phase can be confirmed from AFM observation.

[0175] [Heterocyclic aromatic compound (C) having a tertiary amino group] The heterocyclic aromatic compound (C) having a tertiary amino group (hereinafter sometimes simply referred to as "compound (C)") which may be included in the epoxy resin composition according to this embodiment as needed is not particularly limited and may have a tertiary amino group and an aromatic heterocycle (a heterocycle having aromaticity) in its molecule. If the aromatic heterocycle itself has a tertiary amino group, it is sufficient to have only that aromatic heterocycle. The heterocyclic aromatic compound (C) having a tertiary amino group may also be called an aromatic heterocyclic compound (C) having a tertiary amino group. Examples of compound (C) include imidazole compounds, imidazoline compounds, pyridine compounds having a tertiary amino group, and the like.

[0176] Examples of the imidazole compounds include substituted or unsubstituted imidazoles. Specific examples of the imidazole compounds include, for example, imidazole (SIZ), 1-methylimidazole (1-MZ), 2-methylimidazole, 4-methylimidazole, 1-ethylimidazole, 2-ethylimidazole, 4-ethylimidazole, 1-n-propylimidazole, 2-n-propylimidazole, 1-isopropylimidazole, 2-isopropylimidazole, and 1-n-butylimidazole. L, 2-n-butylimidazole, 1-isobutylimidazole, 2-isobutylimidazole, 2-undecyl-1H-imidazole, 2-heptadecyl-1H-imidazole, 1,2-dimethylimidazole, 1,3-dimethylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole (2E4MZ), 1-phenylimidazole, 2-phenyl-1H-imidazole, 4-methyl- Examples include 2-phenyl-1H-imidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-phenylimidazole isocyanurate adduct, 2-methylimidazole isocyanurate adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1-cyanoethyl-2-phenyl-4,5-di(2-cyanoethoxy)methylimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, and 1-benzyl-2-phenylimidazole hydrochloride. Among these, imidazole (SIZ), 1-methylimidazole (1-MZ), or 2-ethyl-4-methylimidazole (2E4MZ) are preferred.

[0177] Examples of the imidazoline compounds include substituted or unsubstituted imidazolines. Specific examples of the imidazoline compounds include, for example, 2-methylimidazoline, 2-ethylimidazoline, 2-phenylimidazoline, and 2-benzylimidazoline.

[0178] Examples of pyridine compounds having a tertiary amino group include substituted or unsubstituted pyridines having a tertiary amino group. Specific examples of pyridine compounds having a tertiary amino group include dialkylaminopyridines (DAAPs) such as 2-dimethylaminopyridine, 3-dimethylaminopyridine, 4-dimethylaminopyridine (DMAP), 2-diethylaminopyridine, 3-diethylaminopyridine, and 4-diethylaminopyridine (DEAP), pyrrolidinopyridine, piperazinylpyridine, and morpholinopyridine. Among these, dialkylaminopyridines (DAAPs) are preferred, and 4-dimethylaminopyridine (DMAP) is more preferred. These compounds may be used individually or in combination of two or more.

[0179] From the viewpoint of providing an effect that reduces adhesion during dismantling after use without impairing the adhesion after curing or the flexibility of the cured product when the epoxy resin composition according to this embodiment is used as an adhesive, the proportion of compound (C) used is preferably in the range of 2 to 20 parts by mass, more preferably in the range of 3 to 15 parts by mass, and even more preferably in the range of 5 to 12 parts by mass per 100 parts by mass of the epoxy resin.

[0180] The compound (C) is usually used in combination with a curing agent as a curing accelerator in the curing of epoxy resins, but in the epoxy resin composition according to this embodiment, the compound (C) may be used as a curing agent for the epoxy resin.

[0181] [Conductive material (D)] The conductive material (D) can be any material that can be dispersed in an epoxy resin composition to impart conductivity, and examples include a single element of carbon, a metal, or a metal oxide, or a composite material containing one or more selected from the group consisting of carbon, a metal, and a metal oxide.

[0182] Examples of the elemental carbon (carbon material) mentioned above include powders of carbon black such as graphite (which may be expanded graphite), furnace black, and Ketjenblack, as well as carbon nanotubes and carbon fibers.

[0183] Examples of the elemental metals mentioned above include silver, copper, nickel, zinc, aluminum, tungsten, niobium, tantalum, and tin, and may also be alloys containing these atoms. In terms of form, it may be powder, fiber, or foil.

[0184] Examples of the metal oxides include tin oxide (SnO ２ ), antimony oxide (Sb ２ O ５ Examples include particles, fibers, and foil pieces of antimony tin oxide (ATO), indium oxide, indium tin oxide (ITO), zinc oxide, aluminum zinc oxide (AZO), fluorinated tin oxide (FTO), ZnO, etc.

[0185] Furthermore, examples of the composite material include particles having a conductive coating layer formed on the surface of core particles. The core particles are not particularly limited and include, for example, inorganic particles such as colloidal silica particles and silicon oxide particles, polymer particles such as fluororesin particles, acrylic resin particles and silicone resin particles, and organic-inorganic composite particles. Furthermore, examples of materials constituting the conductive coating layer include the metals or alloys thereof mentioned above, and the metal oxides mentioned above. These can be used individually or in combination of two or more.

[0186] Among these, carbon materials are preferred, and among them graphite, expanded graphite, and Ketjenblack are more preferred, with expanded graphite being particularly preferred.

[0187] The conductive material (D) is not limited in shape as described above, but from the viewpoint of uniform dispersion in the adhesive layer and improved disassembly, its average particle size is preferably 0.1 to 500 μm. The average particle size can be measured, for example, using a laser diffraction particle size distribution analyzer Microtrac SPA (manufactured by Nikkiso Co., Ltd.).

[0188] "Expanded Graphite" A method for producing the aforementioned expanded graphite is provided, for example, in Japanese Patent Application Publication No. 2000-44219, but from the viewpoint of heat-curing the epoxy resin in this embodiment, it is preferable that the expanded graphite has heat resistance. A method for producing the aforementioned heat-resistant expanded graphite is provided, for example, in Japanese Patent Application Publication No. 2012-193053.

[0189] The expanded graphite can usually be obtained by treating graphite such as natural graphite, pyrolysis graphite, or quiche graphite with a mixture of concentrated sulfuric acid and a strong oxidizing agent (hereinafter referred to as acid treatment) to generate interlayer compounds between the graphite layers, followed by washing with water, filtering, and drying. The acid treatment method is generally based on concentrated sulfuric acid, such as concentrated sulfuric acid and nitric acid, concentrated sulfuric acid and potassium permanganate, concentrated sulfuric acid and perchloric acid, or concentrated sulfuric acid and hydrogen peroxide. A method using only fuming nitric acid is also known. A neutralization step with a base may be added after the acid treatment. The pH of the extract water of expanded graphite is preferably 5 to 9, more preferably 6 to 8. Furthermore, the pH of the extract water when expanded graphite is heated in water is preferably 4 to 8, more preferably 5 to 8, and even more preferably 6 to 8.

[0190] The aforementioned expanded graphite is selected based on the range of the longest diameter of the particles. For this reason, commercially available expanded graphite is expressed in terms of particle size rather than by its longest diameter. Specifically, commercially available expanded graphite is classified using a sieve, and its characteristics are displayed by indicating the mesh size and pass percentage of the sieve.

[0191] The particle size of the expanded graphite is preferably 20 to 300 mesh, and more preferably 30 to 200 mesh.

[0192] Examples of commercially available expanded graphite include expanded graphite manufactured by Fuji Graphite Industry Co., Ltd. (product names: EXP-50S120K, EXP-50S150), expanded graphite manufactured by Ito Graphite Industry Co., Ltd. (product names: 953240L, 9550250), expanded graphite manufactured by Air Water Inc. (product names: 50LTE-U, MZ-260, CA-60, SS-3, SS-3LA), and expanded graphite manufactured by Graphtec International Corporation (product name: GRAFGUARD®).

[0193] "Ketjenblack" The aforementioned Ketjenblack can be preferably used from the viewpoint that conductivity can be imparted with a small amount of additive. Examples of commercially available Ketjenblack include Ketjenblack EC300J, Carbon ECP, Ketjenblack EC600JD, and Carbon ECP600JD, all manufactured by Lion Specialty Chemicals Co., Ltd.

[0194] The proportion of the conductive material (D) used is preferably in the range of 3 to 40 parts by mass per 100 parts by mass of epoxy resin, more preferably in the range of 5 to 30 parts by mass, even more preferably in the range of 6 to 20 parts by mass, and particularly preferably in the range of 7 to 15 parts by mass, without impairing the adhesiveness after curing or the flexibility of the cured product when the epoxy resin composition according to this embodiment is used as an adhesive.

[0195] [Thermally Expandable Particles] The expanded graphite expands in the adhesive layer when heated, which also has the effect of making it easier to dismantle. From this viewpoint, in order to further improve dismantlingability, particles that expand with heat during dismantling may be further included. The thermally expandable particles may be made of inorganic materials or organic materials. An example of an example of an organic material is a thermally expandable microcapsule in which a volatile expanding agent that becomes gaseous at a temperature below its softening point is microencapsulated using a thermoplastic polymer as the outer shell.

[0196] "Thermally Expandable Microcapsules" A method for manufacturing the aforementioned thermally expandable microcapsules has been provided in the past in Japanese Patent Publication No. 42-26524, but from the viewpoint of thermally curing the epoxy resin in this embodiment, it is preferable that the microcapsules have heat resistance. A method for manufacturing the aforementioned heat-resistant thermally expandable microcapsules is provided, for example, in WO99 / 46320, WO99 / 43758, Japanese Patent Application Publication No. 2002-226620, etc.

[0197] In other words, it is preferable that the particles maintain their original shape without thermal expansion during the heat curing of the epoxy resin, and then expand due to higher temperature thermal energy after use. For example, it is preferable that the outer shell polymer is a polymer obtained by polymerizing a nitrile monomer and a monomer having a carboxyl group as essential components.

[0198] To further enhance heat resistance, it is also preferable to use monomers having an amide group or monomers having a cyclic structure in their side chains.

[0199] The method for producing the heat-resistant, heat-expandable microcapsules described above involves, for example, preparing the outer shell polymer by appropriately blending a thermal polymerization initiator with the above components. Known thermal polymerization initiators such as peroxides and azo compounds can be used. Examples of thermal polymerization initiators include azobisisobutyronitrile (AIBN), benzoyl peroxide, lauryl peroxide, diisopropyl peroxydicarbonate, t-butyl peroxide, and 2,2'-azobis(2,4-dimethylvaleronitrile). Preferably, a thermal polymerization initiator soluble in the polymerizable monomer used is employed. The glass transition temperature (Tg) of the polymer constituting the outer shell of the heat-expandable microcapsule is preferably 120°C or higher. The Tg of the polymer can be calculated from the Tg of each homopolymer of the constituent monomers. Furthermore, the Tg of the polymer can be measured by differential scanning calorimetry (DSC) or the like.

[0200] The volatile expanding agent contained within the microcapsule is a substance that becomes gaseous below the softening point of the outer polymer, and known substances are used. Examples include low-boiling-point liquids such as propane, propylene, butene, n-butane, isobutane, isopentane, neopentane, n-pentane, n-hexane, isohexane, heptane, octane, nonane, decane, petroleum ether, methane, and their respective halides, tetraalkylsilane, or compounds such as azobisisobutyronitrile (AIBN) that decompose into a gaseous state upon heating. The volatile expanding agent is selected as needed depending on the temperature range in which the capsule is to be expanded. The volatile expanding agent may be used alone or in a mixture of two or more types.

[0201] Furthermore, fluorine-based compounds such as hydrochlorofluorocarbons, hydrofluorocarbons, and hydrofluoroethers; commonly known as CFCs, fluorocarbons, and fluoroethers are also cited as examples, but their use should be avoided in the current social climate due to concerns about ozone layer depletion and global warming. In actual production, the general manufacturing methods for conventional thermally expandable microcapsules are used. Specifically, inorganic fine particles such as silica, magnesium hydroxide, calcium phosphate, and aluminum hydroxide are used as dispersion stabilizers in aqueous systems. In addition, condensation products of diethanolamine and aliphatic dicarboxylic acids, polyvinylpyrrolidone, methylcellulose, polyethylene oxide, polyvinyl alcohol, and various emulsifiers are used as dispersion stabilization aids.

[0202] The average particle size of the thermally expandable microcapsules is preferably 1 to 500 μm, more preferably 3 to 100 μm, and even more preferably 5 to 50 μm. A method for measuring the average particle size of the thermally expandable microcapsules is, for example, measurement of the volume-average particle diameter using a particle size distribution analyzer (LA-950, manufactured by HORIBA Corporation).

[0203] The thermally expandable particles may be mixed directly with the epoxy resin, or they may be mixed with the epoxy resin using a masterbatch in which the thermally expandable particles are dispersed at a high concentration in various resins.

[0204] The aforementioned thermally expandable particles can also be commercially available. Examples of commercially available products include the expandable capsules manufactured by Nippon Philite Co., Ltd. (product name: Expandel®), the expandable capsules manufactured by Sekisui Chemical Co., Ltd. (product name: Advancel EM), the microspheres manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd. (product names: F-20D, F-30D, F-40D, FN-100D, FN-100MD, FN-100SD, FN-100SSD, FN-180D, FN-180SD, FN-180SSD, F-190D, F-260D), and the microspheres manufactured by Kureha Corporation (product names: H850D, H880D, S2340D, S2640D). It is preferable to appropriately select particles that do not thermally expand at the curing temperature of the epoxy resin composition but thermally expand at the heating temperature during disassembly.

[0205] The proportion of the thermally expandable particles used is preferably in the range of 3 to 40 parts by mass per 100 parts by mass of epoxy resin, more preferably in the range of 5 to 30 parts by mass, even more preferably in the range of 6 to 20 parts by mass, and particularly preferably in the range of 7 to 15 parts by mass, without impairing the adhesiveness after curing or the flexibility of the cured product when the epoxy resin composition according to this embodiment is used as an adhesive, and without causing the particles to expand sufficiently during dismantling after use to reduce adhesiveness.

[0206] [Glycidyl ether group-containing compound (E)] The glycidyl ether group-containing compound (E) is a glycidyl ether group-containing compound in which a structural unit V having one or more glycidyl ether groups and a structural unit W different from the structural unit V are linked in a V-W-V manner, wherein the structural unit W and the structural unit V are linked by a reversible bond, and it is preferable that the bond is formed by a reversible bond between a furan structure and a maleimide structure via a Diels-Alder reaction.

[0207] The glycidyl ether group-containing compound (E) is incorporated into the crosslinked structure by a curing reaction based on its glycidyl ether group. On the other hand, it retains reversibility even after curing, and therefore exhibits high molecular mobility within the cured product. Consequently, if the cured product is exposed to high temperatures or subjected to impact, resulting in cracking or pulverization, the reversible bonds are broken, exhibiting decomposition properties. Conversely, the reversible bonds are reversibly reformed in low-temperature ranges, including room temperature, resulting in excellent adhesion.

[0208] To introduce a furan-type addition structure (reversible bond) into a compound via the Diels-Alder reaction described above, furan having a glycidyl group on the furan ring or maleimide having a glycidyl group is used. The specific reversible bond substructure can be represented by the following chemical formula. By bonding the R portion in the following formula derived from maleimide, or various glycidyl groups on the ring derived from furan, with other structural units, a reversible bond can be introduced into the compound.

[0209]

[0210] In the Diels-Alder reaction, a conjugated diene and a parent diene undergo an addition reaction to form a six-membered ring. Since the Diels-Alder reaction is an equilibrium reaction, a Retro-Diels-Alder reaction occurs at a predetermined temperature, causing dissociation (de-crosslinking). When mechanical energy such as scratching or external force is applied to the resulting cured product, the C-C bonds of the Diels-Alder reaction unit are preferentially cleaved because their bond energy is lower than that of ordinary covalent bonds. As a result, the cured product exhibits decomposition properties. Furthermore, in the temperature range below the dissociation temperature, the equilibrium shifts in the bond direction of the C-C bonds of the Diels-Alder reaction unit, causing it to form an adduct (Diels-Alder reaction unit) again.

[0211] In the reversible bonding by the Diels-Alder reaction described above, the reversible bonding between the furan structure and the maleimide structure via the Diels-Alder reaction dissociates (de-crosslinks) at around 120°C due to a retro-Diels-Alder reaction. Therefore, the heating temperature required for the cured product to exhibit easy disassembly properties can be reduced, resulting in excellent disassembly properties for applications where high-temperature heating is unsuitable.

[0212] The aforementioned reversible bonds will be present in at least two locations in the target glycidyl ether group-containing compound (E). However, from the viewpoint of excellent adhesion, flexibility, and decomposition properties of the cured product, it is preferable that the structural unit W also has multiple such reversible bonds.

[0213] Furthermore, for the same reasons as described above, it is preferable that the molecular weight of the structural unit W is above a certain size, for example, that its average molecular weight (Mw) is 28 or more. If the structural unit W contains reversible bonds, it is preferable that the molecular weight between the reversible bonds is 28 or more. Although the structural unit W may contain crosslinking functional groups similar to the glycidyl ether group in the structural unit V, it is preferable that the structural unit W does not contain crosslinking (curing) functional groups from the viewpoint of more easily exhibiting the effects of the present invention.

[0214] The structural unit W may contain alkylene chains or alkylene ether chains, for example, when the glycidyl ether group-containing compound (E) is used as a structural adhesive, from the viewpoint of excellent adhesion, flexibility, and decomposition properties of the cured product. In this case, the alkylene chain is more preferably 2 to 30 carbon atoms, and most preferably 4 to 16 carbon atoms. The alkylene ether chain is not particularly limited, but is preferably an alkylene ether chain with 2 to 12 carbon atoms, and its average number of repeats is preferably in the range of 2 to 30.

[0215] The number of glycidyl ether groups in the structural unit V is not particularly limited, but from the viewpoint of industrial availability of raw materials and excellent adhesion, flexibility, and decomposability of the cured product, it is preferably in the range of 1 to 3, and more preferably 1 to 2.

[0216] The average molecular weight (Mw) of the glycidyl ether group-containing compound (E) is not particularly limited, but from the viewpoint of adhesive strength, decomposability, and flexibility of the resulting cured product, it is preferably less than 1000. The epoxy equivalent of the glycidyl ether group-containing compound (E) is preferably 150 to 1000 g / equivalent, more preferably in the range of 180 to 800 g / equivalent, and even more preferably in the range of 200 to 700 g / equivalent.

[0217] The glycidyl ether group-containing compound (E) is preferably a compound represented by the following general formula (4).

[0218] [In formula (4), m ３ Z is an integer between 1 and 4. １ This is given by the following equation (5), Z ３ The structure is one of the structures represented by the following formula (6), and each of the multiple structures in a single molecule may be the same or different. Furthermore, either of the maleimide structures at both ends of formula (4) may or may not have a substituent. If a substituent is present, preferred substituents include alkyl groups, halogen atoms, glycidyl ether groups, 2-methylglycidyl ether groups, etc.

[0219] [In formula (5), the aromatic ring may be unsubstituted or substituted, and * represents a bond point. G is a glycidyl group or a 2-methylglycidyl group.]

[0220] [In formula (6), R'' is independently a hydrogen atom, a methyl group, or an ethyl group; w1 is an integer from 1 to 30; w2 is the average value of the number of repetitions, from 0.5 to 8; w3 is the average value of the number of repetitions, from 0.5 to 6; and * represents a bond point.] Among these, from the viewpoint of ease of raw material availability and the mechanical properties of the resulting cured product, it is preferable that w1 is in the range of 1 to 15, w2 is in the range of 0.5 to 3, w3 is an integer from 1 to 4, and R'' is a hydrogen atom.

[0221] The aforementioned general formula (4) has a reversible bond formed between furan and maleimide at its terminal. The terminal furan structure in general formula (4) has a Z1 which is one of the structures represented by general formula (5), and this glycidyl ether group or 2-methylglycidyl ether group contributes to the curing reaction in the epoxy resin composition described later.

[0222] Z in the formula １ This is a structural unit having a glycidyl ether group or a 2-methylglycidyl ether group, represented by the general formula (5) above. Among these, the following structural formula is preferred from the viewpoint of the ease of obtaining raw materials and the reactivity of the glycidyl group during the curing of the epoxy resin composition. G is a glycidyl group or a 2-methylglycidyl group.

[0223]

[0224] Examples of the glycidyl ether group-containing compound (E) include, but are not limited to, those shown below.

[0225]

[0226] <Method for producing glycidyl ether group-containing compound (E)> The method for producing the glycidyl ether group-containing compound (E) is not particularly limited and can be produced stepwise using known reactions depending on the desired structure, and can also be obtained by appropriately combining commercially available raw materials. A typical production method will be described later.

[0227] The compound represented by the general formula (4) has two Diels-Alder reaction units in the molecule, consisting of a furan structure and a maleimide structure, as reversible bonds, and in the general formula (4), Z １ It can be obtained by using a furan compound having the structure.

[0228] The Diels-Alder reaction, in which a conjugated diene such as the furan structure is added to a parent diene such as the maleimide structure to form a six-membered ring, is an equilibrium reaction. It is well known that at temperatures higher than the temperature at which the addition reaction proceeds, the addition reaction site dissociates, and the reverse reaction, the Retro-Diels-Alder reaction, proceeds, returning the original conjugated diene and parent diene.

[0229] The Diels-Alder reaction can be carried out using known methods. For example, a conjugated diene compound and a parent diene compound are mixed in equimolar amounts, or in some cases, with an excess of one component, and the mixture is heated and melted or dissolved in a solvent, and the reaction product is obtained by stirring at a temperature of 20 to 110°C for 1 to 24 hours. The reaction product can be obtained by filtration or solvent removal without purification, or by commonly used isolation and purification methods such as recrystallization, reprecipitation, and chromatography.

[0230] Furthermore, the phrase "equomoles of the conjugated diene compound and the parent diene compound" means that the conjugated diene structure of the conjugated diene compound and the ethylene structure of the parent diene compound are equimolar. For example, in the case of the glycidyl ether group-containing compound (E) represented by the general formula (4) above, if the furan compound, as the conjugated diene compound, has one conjugated diene structure per molecule, and the maleimide compound (bismaleimide), as the parent diene compound, has two maleimide structures (ethylene structures) per molecule, then "equomoles of the conjugated diene compound and the parent diene compound" means that the furan compound and the maleimide compound (bismaleimide) are in a molar ratio of 2:1.

[0231] <Z １ Furan compounds having the structure > Z １ The structure (Z in the general formula (4) above) １ A furan compound having the same properties as the above is obtained by reacting a furan compound having a hydroxyl group with the epihalohydrin (a3), thereby converting the hydroxyl group in the furan compound to a glycidyl ether group.

[0232] Examples of furan compounds having a hydroxyl group include any of the compounds listed in the following formula. The hydroxyl group in these compounds can be converted to a glycidyl ether group by known methods, such as those described in the examples.

[0233]

[0234] Among the compounds shown in the above formulas, the following compounds are particularly preferred due to their excellent reactivity and the superior adhesion, flexibility, and decomposability of the resulting cured product.

[0235]

[0236] The structures of the above furan compounds include those in which each independently has a hydrogen atom, halogen atom, alkoxy group, aralkyloxy group, aryloxy group, nitro group, amide group, alkyloxycarbonyl group, aryloxycarbonyl group, cyano group, alkyl group, cycloalkyl group, aralkyl group, or aryl group as a substituent. Furthermore, in the structures of the compounds listed in the above formula, the alkoxy group, aralkyloxy group, aryloxy group, carboxyl group, alkyloxycarbonyl group, aryloxycarbonyl group, alkyl group, cycloalkyl group, aralkyl group, and aryl group also include those in which various substituents are further bonded to the carbon atoms they possess.

[0237] The obtained Z １ The epoxy equivalent of the furan compound having the structure is preferably 100 to 500 g / equivalent, more preferably in the range of 110 to 400 g / equivalent, and even more preferably in the range of 120 to 300 g / equivalent.

[0238] The obtained Z １ The viscosity of the furan compound having the structure is preferably 0.1 to 50,000 mPa·s at 25°C, more preferably 0.5 to 30,000 mPa·s, and even more preferably 1 to 20,000 mPa·s.

[0239] <Z ３ Maleimide compounds (bismaleimides) having the structure of the above Z ３The structure (Z in the general formula (4) above) ３ Maleimide compounds (bismaleimides) having the same property are intermediates of the parent diene before the Diels-Alder reaction, and can be represented by the following general formula (1)', for example.

[0240] [In the ceremony, Z ３ Z in the general formula (4) is ３ It is the same as [this].

[0241] The maleimide compound described above is preferably one with the following structure, from the viewpoint of ease of obtaining raw materials, solvent solubility during the Diels-Alder reaction, and adhesive strength when the compound obtained by the Diels-Alder reaction is cured.

[0242]

[0243] Said Z ３ Maleimide compounds (bismaleimides) having the structure may be commercially available or synthesized. Examples of commercially available maleimide compounds include maleimide compounds from Yamato Kasei Co., Ltd. (product names: BMI-1000, BMI-1000H, BMI-1100, BMI-1100H, BMI-3000, BMI-3000H, BMI-4000, BMI-5100, BMI-7000, BMI-7000H, BMI-TMH), maleimide compounds from K.I. Kasei (product names: BMI, BMI-70, BMI-80), maleimide compounds from JFE Chemical (product names: JBM-200N, JBM-300N, JBM-800N), DESIGNER Examples include maleimide compounds manufactured by MOLECULES (trade names: BMI-689, BMI-1400, BMI-1500, BMI-1700, BMI-3000, BMI-5000, etc.).

[0244] Examples of methods for synthesizing the maleimide compound include the following first and second methods. For example, the first method is Z ３The maleimide compound can be synthesized by reacting a diamine compound having the structure and two amino groups with maleic anhydrides. As a second method, for example, the maleimide compound (MI-ts-N-st-MI) can be synthesized by reacting a compound having two functional groups S (S-N-S) with a maleimide compound having a functional group T that can react with functional group S (T-MI). MI corresponds to the terminal maleimide structure, and "-ts-N-st-" is the above Z ３ This corresponds to the structure shown. "ts" corresponds to the structure obtained by the reaction of substituent T and substituent S.

[0245] "First Method" In the first method, for example, formula: NH ２ -Z ３ -NH ２ The aforementioned diamine compound can be synthesized by known methods using maleic anhydrides. For example, the diamine compound can be reacted with maleic anhydrides in a solvent under an acid catalyst to form maleamic acid, which can then be maleimidized (ring-closing by dehydration) using an acid catalyst to obtain a crude maleimide compound solution, which can then be purified to synthesize the compound. Examples of maleic anhydrides include maleic anhydride, citraconic anhydride, and 2,3-dimethylmaleic anhydride. Among these, maleic anhydride is preferred.

[0246] "Second Method" The maleimide compound (bismaleimide) can be synthesized by using a compound having hydroxyl groups at both ends as the compound having the two functional groups S (S-N-S), and using glycidyloxyphenylmaleimide as the maleimide compound having the functional group T (T-MI). The hydroxyl groups of the compound having hydroxyl groups at both ends can be reacted with the glycidyloxy group of glycidyloxyphenylmaleimide to introduce a maleimide structure at the end. The compound having hydroxyl groups at both ends can be synthesized, for example, by the following method: A compound having hydroxyl groups at the end can be obtained by reacting a diglycidyl ether or aliphatic divinyl ether of an aliphatic dihydroxy compound with an aromatic hydroxy compound.

[0247] Alternatively, the maleimide compound (bismaleimide) can be synthesized by using a compound having glycidyl ether groups at both ends as the compound having the two functional groups S (S-N-S), and using hydroxyphenylmaleimide as the maleimide compound having the functional group T (T-MI). For example, after obtaining the compound having hydroxyl groups at both ends, it can be epoxidized to make the ends glycidyl ether groups, and then a maleimide structure can be introduced at the ends by reacting it with hydroxyphenylmaleimide or the like.

[0248] Alternatively, the maleimide compound (bismaleimide) can be synthesized by using a compound having halogenated alkyl groups at both ends as the compound having the two functional groups S (S-N-S), and using hydroxyphenylmaleimide as the maleimide compound having the functional group T (T-MI). For example, an aromatic dihydroxy compound can be reacted with a dihalogenated alkyl compound or a dihalogenated aralkyl compound to obtain a compound having halogenated alkyl groups at the end, and then a maleimide structure can be introduced at the end by reacting it with hydroxyphenylmaleimide or the like.

[0249] The diglycidyl ether of the aliphatic dihydroxy compound is not particularly limited, and for example, the same specific examples as the diglycidyl etherified product (a1) of the dihydroxy compound having an alkylene chain and a polyether chain can be cited.

[0250] Among these, compounds having a structure in which glycidyl groups are linked to both ends of an alkylene chain having 12 to 14 carbon atoms via ether groups are preferred in terms of the excellent adhesion, flexibility, and decomposability of the resulting cured product, and the use of 1,12-dodecanediol diglycidyl ether, 1,13-tridecanediol, and 1,14-tetradecanediol diglycidyl ether is most preferred.

[0251] The aliphatic divinyl ether is not particularly limited and includes, for example, divinyl ethers with linear alkylene groups such as polyethylene glycol divinyl ether, polypropylene glycol divinyl ether, polytetramethylene glycol divinyl ether, 1,3-butylene glycol divinyl ether, 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether, 1,9-nonanediol divinyl ether, and 1,10-decanediol divinyl ether, and divinyl ethers with branched alkylene groups such as neopentyl glycol divinyl ether, divinyl ethers containing cycloalkane structures such as 1,4-cyclohexanediol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, tricyclodecanediol divinyl ether, tricyclodecanedimethanol divinyl ether, pentacyclopentadecanedimethanol divinyl ether, and pentacyclopentadecanediol divinyl ether, and bisphenol A divinyl ether, bisphenol F divinyl ether, and hydroquinone divinyl ether, which may be used alone or in combination of two or more types.

[0252] Among these, polyether structures or divinyl ethers with linear alkylene chains having 4 to 10 carbon atoms are preferred in terms of excellent adhesion, flexibility, and decomposability of the resulting cured product, and polyethylene glycol divinyl ether, polypropylene glycol divinyl ether, polytetramethylene glycol divinyl ether, 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether, 1,9-nonanediol divinyl ether, and 1,10-decanediol divinyl ether are most preferred.

[0253] The aromatic hydroxy compound is not particularly limited, and for example, the same specific example as the aromatic hydroxy compound (a2) can be given.

[0254] Among these, bisphenols are preferred due to their excellent adhesion, flexibility, and decomposability when cured, and bis(4-hydroxyphenyl)methane and 2,2-bis(4-hydroxyphenyl)propane are particularly preferred due to their remarkable toughness-imparting properties. Furthermore, when moisture resistance of the cured product is important, it is preferable to use phenols containing an alicyclic structure.

[0255] The reaction ratio of the diglycidyl ether of the aliphatic dihydroxy compound to the aromatic hydroxy compound is preferably within the range of 1 / 1.01 to 1 / 5.0 (molar ratio) for the former / latter, and it is preferable that (a1) / (a2) is 1 / 1.02 to 1 / 3.0 (molar ratio) in order to obtain a cured product that has a good balance of flexibility and heat resistance.

[0256] The reaction between the diglycidyl ether of the aliphatic dihydroxy compound and the aromatic hydroxy compound is preferably carried out in the presence of a catalyst. Examples of such catalysts include those described above in "Catalysts used in the reaction between (a1) and (a2)".

[0257] Furthermore, the reaction between the diglycidyl ether of the aliphatic dihydroxy compound and the aromatic hydroxy compound can be carried out without a solvent or in the presence of an organic solvent. Examples of organic solvents that can be used are those described above in "Solvents used in the reaction between (a1) and (a2)". The amount of organic solvent used is usually 50 to 300% by mass, preferably 100 to 250% by mass, relative to the total mass of the raw materials charged. These organic solvents may be used alone or in combination of two or more. To carry out the reaction quickly, it is preferable to use no solvent, while the use of dimethyl sulfoxide is preferable in that it can reduce impurities in the final product.

[0258] The reaction temperature when carrying out the above reaction is usually 50 to 180°C, and the reaction time is usually 1 to 10 hours. A reaction temperature of 100 to 160°C is preferred in that it can reduce impurities in the final product. If the resulting compound is highly discolored, antioxidants or reducing agents may be added to suppress this discoloration. The antioxidants are not particularly limited, but examples include hindered phenol compounds such as 2,6-dialkylphenol derivatives, divalent sulfur compounds, and phosphite ester compounds containing trivalent phosphorus atoms. The reducing agents are not particularly limited, but examples include hypophosphorous acid, phosphite, thiosulfite, sulfite, hydrosulfite, or salts thereof.

[0259] After the reaction is complete, the reaction mixture may be neutralized or washed with water until its pH is 3 to 7, preferably 5 to 7. Neutralization and washing can be carried out according to conventional methods. For example, when a basic catalyst is used, acidic substances such as hydrochloric acid, sodium monohydrogen phosphate, p-toluenesulfonic acid, or oxalic acid can be used as neutralizing agents. After neutralization or washing, the solvent can be removed under reduced pressure and heating if necessary to concentrate the product and obtain the compound.

[0260] The reaction ratio of the aliphatic divinyl ether to the aromatic hydroxy compound is preferably within the range of 1 / 1.01 to 1 / 5.0 (molar ratio), and it is preferable that (a1) / (a2) is 1 / 1.02 to 1 / 3.0 (molar ratio) in order to obtain a cured product that has a good balance of flexibility and heat resistance.

[0261] The reaction between the aliphatic divinyl ether diglycidyl ether and the aromatic hydroxy compound proceeds sufficiently without the use of a catalyst, but a catalyst may be used as appropriate to improve the selection of starting materials and the reaction rate. Examples of catalysts that can be used here include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid; organic acids such as toluenesulfonic acid, methanesulfonic acid, xylenesulfonic acid, trifluoromethanesulfonic acid, oxalic acid, formic acid, trichloroacetic acid, and trifluoroacetic acid; Lewis acids such as aluminum chloride, iron chloride, tin chloride, gallium chloride, titanium chloride, aluminum bromide, gallium bromide, boron trifluoride ether complex, and boron trifluoride phenol complex. The amount of catalyst used is usually in the range of 10 ppm to 1% by mass relative to the mass of the divinyl ether compound. In this case, it is preferable to select the type and amount of catalyst so as not to cause a nucleation reaction of the vinyl group to the aromatic ring.

[0262] Furthermore, the reaction between the aliphatic divinyl ether and the aromatic hydroxy compound can be carried out without a solvent or in the presence of an organic solvent. Examples of organic solvents used include those described above in "Solvents used in the reaction between (a1) and (a2)". The amount of organic solvent used is usually 50 to 300% by mass, preferably 100 to 250% by mass, relative to the total mass of the raw materials. These organic solvents may be used individually or in combination of two or more types.

[0263] The reaction temperature for the above reaction is usually 50 to 150°C, and the reaction time is usually 0.5 to 10 hours. In this case, the reaction is preferably carried out under an oxygen atmosphere in order to prevent the self-polymerization of the vinyl ether group.

[0264] After the reaction is complete, if the organic solvent was used, it can be removed under reduced pressure heating; if the catalyst was used, it can be deactivated with an inactivator or the like as necessary, and then removed by washing with water or filtration to obtain the compound.

[0265] When the compound having two or more functional groups S (S-N-S) is a compound having hydroxyl groups at both ends, and the maleimide compound having the functional group T (T-MI) is glycidyloxyphenylmaleimide, the hydroxyl groups of the compound having hydroxyl groups at both ends are reacted with the glycidyloxyphenylmaleimide, etc. At this time, sodium hydroxide, potassium hydroxide, potassium carbonate, etc. can be used as a catalyst, and toluene, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, acetonitrile, dimethylformamide, etc. may be used as a solvent. The reaction temperature is room temperature to 200°C, and the reaction time is 1 to 24 hours. After that, the catalyst is removed by filtration, etc., and the target compound can be obtained by extraction, solvent removal, etc. The Diels-Alder reaction with this compound is as described above.

[0266] The aliphatic hydroxy compounds are not particularly limited, and include, for example, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, and 1,16-hexadecanediol. Examples include diols, 2-methyl-1,11-undecanediol, 3-methyl-1,11-undecanediol, 2,6,10-trimethyl-1,11-undecanediol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polypentamethylene glycol diglycidyl ether, polyhexamethylene glycol diglycidyl ether, polyheptamethylene glycol diglycidyl ether, etc., which may be used individually or in combination of two or more types.

[0267] Among these, it is preferable to use a polyether structure or a dihydroxy compound of a linear alkylene chain having 12 to 14 carbon atoms, as these compounds exhibit excellent adhesion, flexibility, and decomposability of the resulting cured product. The most preferable are polyethylene glycol, polypropylene glycol, polytetramethylene glycol, 1,12-dodecanediol, 1,13-tridecanediol, and 1,14-tetradecanediol.

[0268] The aforementioned alkyl dihalide compounds are not particularly limited, and examples include 1,4-dichlorobutane, 1,5-dichloropentane, 1,6-dichlorohexane, 1,7-dichloroheptane, 1,8-dichlorooctane, 1,9-dichlorononane, 1,10-dichlorodecane, 1,11-dichloroundecane, 1,12-dichlorododecane, 1,4-dibromobutane, 1,5-dibromopentane, 1,6-dibromohexane, 1,7-dibromoheptane, 1,8-dibromooctane, 1,9-dibromononane, 1,10-dibromodecane, 1,11-dibromoundecane, 1,12-dibromododecane, etc., and may be used alone or in combination of two or more types.

[0269] The aforementioned dihalogenated aralkyl compound is not particularly limited, and examples include dichloroxylene, dichloromethylbiphenyl, dibromoxylen, dibromomethylbiphenyl, etc., and may be used alone or in combination of two or more types.

[0270] The reaction ratio of the aromatic dihydroxy compound to the dihalogenated alkyl compound or the dihalogenated aralkyl compound is preferably within the range of 1 / 1.01 to 1 / 5.0 (molar ratio) for the former / latter, and is preferably (a1) / (a2) is 1 / 1.02 to 1 / 3.0 (molar ratio) in order to obtain a cured product that has a good balance of flexibility and heat resistance.

[0271] The reaction between the aromatic dihydroxy compound and the alkyl dihalide compound or the aralkyl dihalide compound is preferably carried out in the presence of a catalyst. Various catalysts can be used, such as alkali (earth) metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and calcium hydroxide, and alkali metal carbonates such as sodium carbonate and potassium carbonate. These may be used individually or in combination of two or more. Among these, sodium hydroxide, potassium hydroxide, and potassium carbonate are preferred because the reaction proceeds rapidly and they have a high effect in reducing the amount of impurities. The amount of these catalysts used is not particularly limited, but it is preferable to use 0.0001 to 10 moles per mole of phenolic hydroxyl group of the aromatic hydroxy compound. The form of these catalysts is also not particularly limited and may be used in aqueous solution form or in solid form.

[0272] Furthermore, the reaction between the aromatic dihydroxy compound and the dihalogenated alkyl compound or the dihalogenated aralkyl compound can be carried out without a solvent or in the presence of an organic solvent. Examples of organic solvents used include those described above in "Solvents used in the reaction between (a1) and (a2)". The amount of organic solvent used is usually 50 to 300% by mass, preferably 100 to 250% by mass, relative to the total mass of the raw materials. These organic solvents may be used individually or in combination of two or more types.

[0273] The reaction temperature when carrying out the above reaction is usually 20 to 150°C, and the reaction time is usually 1 to 24 hours. A reaction temperature of 20 to 100°C is preferred from the viewpoint of reducing impurities in the final product.

[0274] When the compound having two or more functional groups S (S-N-S) is a compound having halogenated alkyl groups at both ends, and the maleimide compound having the functional group T (T-MI) is hydroxyphenylmaleimide, the hydroxyphenylmaleimide is reacted with the halogenated alkyl groups of the compound having halogenated alkyl groups at both ends. At this time, sodium hydroxide, potassium hydroxide, potassium carbonate, etc. can be used as a catalyst, and toluene, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, acetonitrile, dimethylformamide, etc. may be used as a solvent. The reaction temperature is 20 to 200°C, and the reaction time is 1 to 24 hours. After that, the catalyst is removed by filtration, etc., and the target compound can be obtained by extraction, solvent removal, etc.

[0275] The obtained Z ３ The maleimide group equivalent of the maleimide compound having the structure is preferably 100 to 1000 g / equivalent, more preferably in the range of 110 to 800 g / equivalent, and even more preferably in the range of 120 to 500 g / equivalent. ３ The melting point of the maleimide compound having the structure is preferably in the range of 40 to 250°C, more preferably in the range of 50 to 220°C, and even more preferably in the range of 60 to 210°C. ３ The gelation time at 200°C for a maleimide compound having the structure is preferably 0.5 to 220 minutes, more preferably in the range of 1 to 200 minutes, and even more preferably in the range of 1.2 to 180 minutes.

[0276] [Curing agent (F)] The epoxy resin composition according to this embodiment preferably further contains a curing agent (F) that can react with epoxy groups. The curing agent (F) may have a reversible bond. An example of the reversible bond of the curing agent (F) is a reversible bond contained in the glycidyl ether group-containing compound (E).

[0277] The curing agent (F) is not particularly limited as long as it reacts with epoxy groups, and examples include amine compounds, acid anhydrides, amide compounds, phenolic hydroxyl group-containing compounds, carboxylic acid compounds, thiol compounds, and activated ester resins. Note that the amine compound does not include the heterocyclic aromatic compound (C) having a tertiary amino group that is included in the epoxy resin composition according to this embodiment. The curing agent (F) can be appropriately selected depending on the physical properties of the desired cured product, but it is particularly preferable to use an amine compound and / or a phenolic hydroxyl group-containing compound from the viewpoint of excellent adhesion and decomposability of the resulting cured product.

[0278] Examples of the amine compounds include trimethylenediamine, ethylenediamine, N,N,N',N'-tetramethylethylenediamine, pentamethyldiethylenetriamine, triethylenediamine, dipropylenediamine, N,N,N',N'-tetramethylpropylenediamine, tetramethylenediamine, pentanediamine, hexamethylenediamine, trimethylhexamethylenediamine, N,N,N',N'-tetramethylhexamethylenediamine, N,N-dimethylcyclohexylamine, diethylenetriamine (DTA), and triethylenetetramine. Aliphatic amine compounds such as tetraethylenepentamine, dimethylaminopropylamine, diethylaminopropylamine, dibutylaminopropylamine, 1,4-diazabicyclo(2,2,2)octane(triethylenediamine), polyoxyethylenediamine, polyoxypropylenediamine, bis(2-dimethylaminoethyl) ether, dimethylaminoethoxyethoxyethanol, triethanolamine, dimethylaminohexanol, benzylmethylamine, dimethylbenzylamine, m-xylenediamine, α-methylbenzylmethylamine, etc.

[0279] Alicyclic and heterocyclic amine compounds such as piperidine, piperazine, menthanediamine, isophoronediamine, methylmorpholine, ethylmorpholine, N,N',N''-tris(dimethylaminopropyl)hexahydro-s-triazine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxyspiro(5,5)undecane adduct, N-aminoethylpiperazine, trimethylaminoethylpiperazine, bis(4-aminocyclohexyl)methane, N,N'-dimethylpiperazine, and 1,8-diazabicyclo-[5.4.0]-undecene (DBU);

[0280] Aromatic amine compounds such as o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, pyridine, and picoline;

[0281] Modified polyamine compounds such as epoxy-modified polyamines (polyamines modified by epoxy compound addition reactions), Michael addition-modified polyamines (polyamines modified by Michael addition reactions), Mannich-modified polyamines (polyamines modified by Mannich addition reactions), thiourea-modified polyamines (polyamines modified by thiourea addition reactions), and ketone-modified polyamines (polyamines modified by ketone blockade reactions);

[0282] Examples include dicyandiamide, guanidine, organic acid hydrazides, diaminomaleonitriles, amineimides, boron trifluoride-piperidine complexes, boron trifluoride-monoethylamine complexes, and other amine compounds.

[0283] Examples of the aforementioned acid anhydrides include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, polypropylene glycol maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride.

[0284] Examples of the amide compound include polyamidoamines. Examples of polyamidoamines include those obtained by reacting aliphatic polyamines or polyamines having polyoxyalkylene chains.

[0285] The phenolic hydroxyl group-containing compound is not particularly limited, and for example, the same specific examples as the aromatic hydroxy compound (a2) can be given.

[0286] Examples of the carboxylic acid compounds include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid, as well as carboxylic acid compounds such as fatty acids and dimer acids; and carboxylic acid polymers such as carboxylic acid-terminated polyesters, polyacrylic acid, maleic acid-modified polypropylene glycol, and copolymers of styrene and maleic anhydride.

[0287] The thiol compound is preferably one that contains two or more thiol groups in one molecule. Examples include 3,3'-dithiodipropionic acid, trimethylolpropane tris(thioglycolate), pentaerythritol tetrakis(thioglycolate), ethylene glycol dithioglycolate, 1,4-bis(3-mercaptobutyryloxy)butane, tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), dipentaerythritol hexakis(3-mercaptopropionate), 1,3,4,6-tetrakis(2-mercaptoethyl)glycoluryl, 4-butanedithiol, 1,6-hexanedithiol, and 1,10-decandithiol.

[0288] There are no particular restrictions on the activated ester resin, but generally, compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are preferred. The activated ester resin is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. Particularly from the viewpoint of improving heat resistance, activated ester resins obtained from a carboxylic acid compound or its halide and a hydroxy compound are preferred, and activated ester resins obtained from a carboxylic acid compound and / or its halide and a phenol compound and / or a naphthol compound are more preferred. Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, etc., or their halides. Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, dihydroxydiphenyl ether, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, and dicyclopentadiene-phenol addition resins.

[0289] Specifically, the active ester resins are preferably active ester resins containing a dicyclopentadiene-phenol addition structure, active ester resins containing a naphthalene structure, active ester resins which are acetylated phenol novolacs, and active ester resins which are benzoylated phenol novolacs. Among these, active ester resins containing a dicyclopentadiene-phenol addition structure and active ester resins containing a naphthalene structure are more preferred in that they are excellent at improving peel strength.

[0290] When using the curing agent (F), it may be used alone or in combination of two or more types. For applications such as underfill materials and general paints, it is preferable to use the amine compound, acid anhydride, and / or carboxylic acid compound. For adhesives and flexible wiring board applications, the amine compound, particularly dicyandiamide, is preferred in terms of workability, curability, and long-term stability. For semiconductor encapsulation materials, a solid type phenolic hydroxyl group-containing compound is preferred in terms of the heat resistance of the cured product. Furthermore, for applications requiring low-temperature curing, such as battery adhesives, the aliphatic amine compound or the thiol compound is preferred.

[0291] Furthermore, if the epoxy resin composition according to this embodiment contains the glycidyl ether group-containing compound (E), it is preferable that the curing agent (F) is an amino group-containing compound and / or a phenolic hydroxyl group-containing compound having a reversible bond, from the viewpoint of being able to express its effects even more effectively.

[0292] Examples of amino group-containing compounds having the reversible bond include amino group-containing compounds in which structural units V' and W' are linked by V'-W'-V'. The structural unit V' has one or more amino groups, and the structural units V' and W' are different. The structural units V' and W' are linked by the reversible bond. The reversible bond can be the same as the reversible bond in the glycidyl ether group-containing compound (E) in this embodiment. That is, the structural unit V' and W' may be linked by a reversible bond formed by a Diels-Alder reaction between a furan structure and a maleimide structure.

[0293] Examples of phenolic hydroxyl group-containing compounds having the reversible bond include phenolic hydroxyl group-containing compounds in which structural units V' and W' are linked by V'-W'-V'. The structural unit V' has one or more hydroxyl groups, and the structural units V' and W' are different. The structural units V' and W' are linked by the reversible bond. The reversible bond can be the same as the reversible bond in the glycidyl ether group-containing compound (E) in this embodiment. That is, the structural unit V' and W' may be linked by a reversible bond formed by a Diels-Alder reaction between a furan structure and a maleimide structure.

[0294] [Other Epoxy Resins] Furthermore, in the case of adopting an embodiment in which the epoxy resin composition according to this embodiment forms a phase separation structure using the epoxy resin (A) and the epoxy resin (B), other epoxy resins other than the glycidyl ether group-containing compound (E) may also be used in combination. When the epoxy resin composition according to the embodiment does not contain the glycidyl ether group-containing compound (E), the total amount of the epoxy resin (A) and the epoxy resin (B) in the epoxy resin composition according to the embodiment is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, and particularly preferably 80% by mass or more. Also, when the epoxy resin composition according to the embodiment contains the glycidyl ether group-containing compound (E), the total amount of the epoxy resin (A), the epoxy resin (B), and the glycidyl ether group-containing compound (E) in the epoxy resin composition according to the embodiment is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, and particularly preferably 80% by mass or more.

[0295] The aforementioned other epoxy resins are not limited in any way other than not belonging to epoxy resin (A), epoxy resin (B), or glycidyl ether group-containing compound (E), and include, for example, liquid epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AD ​​type epoxy resin, polyhydroxybenzene type epoxy resin, polyhydroxynaphthalene type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, brominated epoxy resins such as brominated phenol novolac type epoxy resin, solid bisphenol A type epoxy resin, and phenol novolac type epoxy resin. Examples include cresol novolac epoxy resin, triphenylmethane epoxy resin, tetraphenylethane epoxy resin, dicyclopentadiene-phenol addition reaction epoxy resin, phenol aralkyl epoxy resin, phenylene ether epoxy resin, naphthylene ether epoxy resin, naphthol novolac epoxy resin, naphthol aralkyl epoxy resin, naphthol-phenol copolymer novolac epoxy resin, naphthol-cresol copolymer novolac epoxy resin, biphenyl-modified novolac epoxy resin, etc. These can be used individually or in combination of two or more, and it is preferable to select and use them according to the intended application and the physical properties of the cured product.

[0296] The concentration of reversible bonds in the epoxy resin composition according to the above embodiment is preferably 0.10 mmol / g or more relative to the total mass of curable components in the epoxy resin composition. With such a configuration, the adhesion, flexibility, and decomposability of the cured product obtained from the epoxy resin composition are all further improved. The concentration of the reversible bonds is more preferably 0.10 to 3.00 mmol / g, and even more preferably 0.15 to 2.00 mmol / g. Furthermore, when the glycidyl ether group-containing compound (E) has multiple reversible bonds, or when the curing agent (F) uses the phenolic hydroxyl group-containing compound having the above-mentioned reversible bonds alone or in combination with other curing agents, the total concentration of such reversible bonds is preferably 0.10 mmol / g or more, more preferably 0.10 to 3.00 mmol / g, and even more preferably 0.15 to 2.00 mmol / g, relative to the total mass of curable components in the epoxy resin composition. The concentration of the reversible bond can be appropriately selected based on the glass transition temperature, defined by the tanδ peak top of the dynamic viscoelasticity analyzer (DMA) of the target cured product. For example, if the glass transition temperature is used as a guideline, if the glass transition temperature of the cured product is near room temperature, sufficient adhesion, flexibility, and decomposition properties are more likely to be exhibited even at the lower end of the preferred concentration range. On the other hand, if the glass transition temperature of the target cured product is above 100°C as a guideline, the functions are more likely to be exhibited at the higher end of the preferred concentration range. However, in the temperature range above the glass transition temperature measured by DMA, molecular mobility is generally high, and sufficient adhesion, flexibility, and decomposition properties are more likely to be exhibited even at low concentrations of the glycidyl ether group-containing compound (E). Therefore, the effect of exhibiting adhesion, flexibility, and decomposition properties can also be adjusted by appropriately adjusting the aging temperature for repair or the heating temperature for reshaping. Thus, the relationship between the glass transition temperature of the cured product and the concentration of the reversible bond is not limited to these.

[0297] The ratio of the total epoxy groups to the total functional groups that can react with these epoxy groups in the epoxy resin composition according to this embodiment is not particularly limited, but from the viewpoint of good mechanical properties of the resulting cured product, it is preferable that the amount of functional groups that can react with epoxy groups is 0.4 to 1.5 equivalents per 1 equivalent of the total epoxy groups in the resin composition. The functional groups that can react with epoxy groups include functional groups such as hydroxyl groups and amino groups contained in the curing agent (F).

[0298] [Curing accelerator] The epoxy resin composition according to this embodiment may contain a curing accelerator that does not belong to the heterocyclic aromatic compound (C) having a tertiary amino group. Various curing accelerators can be used, but examples include urea compounds, phosphorus compounds, tertiary amines, organic acid metal salts, Lewis acids, amine complex salts, etc.

[0299] Examples of the urea compounds include p-chlorophenyl-N,N-dimethylurea, 3-phenyl-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-N,N-dimethylurea, and N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea.

[0300] Examples of the phosphorus compounds include alkylphosphines such as ethylphosphine and butylphosphine, primary phosphines such as phenylphosphine; dialkylphosphines such as dimethylphosphine and dipropylphosphine; secondary phosphines such as diphenylphosphine and methylethylphosphine; and tertiary phosphines such as trimethylphosphine, triethylphosphine, and triphenylphosphine.

[0301] Examples of the aforementioned tertiary amines include triethylamine, N,N-dimethylbenzylamine, N,N-diethylbenzylamine, 1,8-diazabicyclo[5.4.0]undecene, and 1,4-diazabicyclo[2.2.2]octane.

[0302] Examples of the aforementioned metal organic acid salts include cobalt organic acid salts such as cobalt thiocyanate, cobalt octoate, cobalt naphthenate, and cobalt acetate; copper organic acid salts such as copper naphthenate; manganese organic acid salts such as manganese naphthenate; and vanadium organic acid salts such as vanadyl naphthenate and vanadyl stearate.

[0303] Examples of the Lewis acid include complexes of boron halides and bases, such as boron trifluoride-piperidine complex, boron trifluoride-monoethylamine complex, boron trifluoride-triethanolamine complex, and boron trichloride-octylamine complex.

[0304] Examples of the amine complex salts include boron trifluoride monoethylamine complex, boron trifluoride diethylamine complex, boron trifluoride isopropylamine complex, boron trifluoride chlorophenylamine complex, boron trifluoride benzylamine complex, boron trifluoride aniline complex, or mixtures thereof, and other boron trifluoride complexes.

[0305] When used as an adhesive, urea compounds, particularly 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), are preferred due to their excellent workability and low-temperature curing properties. When used as a semiconductor encapsulating material, triphenylphosphine is preferred among phosphorus compounds, and 1,8-diazabicyclo-[5.4.0]-undecene (DBU) is preferred among tertiary amines due to their excellent curability, heat resistance, electrical properties, and moisture resistance reliability.

[0306] [Other thermosetting resins and thermoplastic resins] In addition, the epoxy resin composition according to this embodiment may be used in combination with other thermosetting resins and thermoplastic resins, to the extent that it does not impair the effects of this embodiment.

[0307] Other thermosetting resins include, for example, cyanate ester resins, resins having a benzoxazine structure, vinyl benzyl compounds, acrylic compounds, and the like. When using any of the above-mentioned other thermosetting resins in combination, the amount used is not particularly limited as long as it does not hinder the effects of this embodiment, but it is preferably in the range of 1 to 50 parts by mass per 100 parts by mass of the epoxy resin composition.

[0308] Examples of the cyanate ester resins include bisphenol A type cyanate ester resin, bisphenol F type cyanate ester resin, bisphenol E type cyanate ester resin, bisphenol S type cyanate ester resin, bisphenol sulfide type cyanate ester resin, phenylene ether type cyanate ester resin, naphthylene ether type cyanate ester resin, biphenyl type cyanate ester resin, tetramethylbiphenyl type cyanate ester resin, polyhydroxynaphthalene type cyanate ester resin, phenol novolac type cyanate ester resin, and cresol novolac. Examples include cyanate ester resins of type k, triphenylmethane, tetraphenylethane, dicyclopentadiene-phenol addition reaction, phenol aralkyl, naphthol novolac, naphthol aralkyl, naphthol-phenol co-condensed novolac, naphthol-cresol co-condensed novolac, biphenyl-modified novolac, and anthracene. These can be used individually or in combination of two or more types.

[0309] Among the cyanate ester resins mentioned above, bisphenol A type cyanate ester resin, bisphenol F type cyanate ester resin, bisphenol E type cyanate ester resin, polyhydroxynaphthalene type cyanate ester resin, naphthylene ether type cyanate ester resin, and novolac type cyanate ester resin are preferred in terms of obtaining cured products with particularly excellent heat resistance, and dicyclopentadiene-phenol addition reaction type cyanate ester resin is preferred in terms of obtaining cured products with excellent dielectric properties.

[0310] There are no particular limitations on the resin having the benzoxazine structure, but examples include the reaction product of bisphenol F, formalin, and aniline (F-a type benzoxazine resin), the reaction product of diaminodiphenylmethane, formalin, and phenol (P-d type benzoxazine resin), the reaction product of bisphenol A, formalin, and aniline, the reaction product of dihydroxydiphenyl ether, formalin, and aniline, the reaction product of diaminodiphenyl ether, formalin, and phenol, the reaction product of dicyclopentadiene-phenol addition resin, formalin, and aniline, the reaction product of phenolphthalein, formalin, and aniline, and the reaction product of diphenyl sulfide, formalin, and aniline. These may be used individually or in combination of two or more types.

[0311] Furthermore, various vinyl polymers may be used in combination. Examples of the aforementioned vinyl polymers include homopolymers or copolymers thereof of vinyl compounds such as polyhydroxystyrene, polystyrene, polyvinylnaphthalene, polyvinylanthracene, polyvinylcarbazole, polyindene, polyacenaphthylene, polynorbornene, polycyclodecene, polytetracyclododecene, polynortricycline, and poly(meth)acrylate.

[0312] The thermoplastic resins mentioned above refer to resins that can be melt-molded by heating. Specific examples include polyethylene resin, polypropylene resin, polystyrene resin, rubber-modified polystyrene resin, acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene (AS) resin, polymethyl methacrylate (PMMA) resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyethylene terephthalate resin, ethylene vinyl alcohol resin, cellulose acetate resin, ionomer resin, polyacrylonitrile resin, polyamide resin, polyacetal resin, polybutylene terephthalate resin, polylactic acid resin, polyphenylene ether resin, modified polyphenylene ether resin, polycarbonate resin, polysulfone resin, polyphenylene sulfide (PPS) resin, polyetherimide resin, polyethersulfone resin, polyarylate resin, thermoplastic polyimide resin, polyamideimide resin, polyetheretherketone resin, polyketone resin, liquid crystal polyester resin, fluororesin, syndiotactic polystyrene resin, and cyclic polyolefin resin. These thermoplastic resins can be used individually or in combination of two or more types.

[0313] When using the aforementioned other resins, the mixing ratio can be arbitrarily set according to the application, but from the standpoint of excellent adhesion and decomposability when cured, it is preferable that the ratio of the aforementioned other resins is 0.5 to 100 parts by mass per 100 parts by mass of epoxy resin.

[0314] [Non-halogen flame retardant] When the epoxy resin composition according to this embodiment is used in applications requiring high flame retardancy, a non-halogen flame retardant that substantially does not contain halogen atoms may be added.

[0315] Examples of the non-halogenated flame retardants include phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, inorganic flame retardants, and organometallic salt-based flame retardants. There are no restrictions on their use; they may be used alone or in combination of two or more types.

[0316] The phosphorus-based flame retardant can be either an inorganic compound or an organophosphorus compound. Examples of the inorganic compound include ammonium phosphates such as red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, and polyammonium phosphate, as well as inorganic nitrogen-containing phosphorus compounds such as phosphate amides.

[0317] Furthermore, it is preferable that the red phosphorus is surface-treated to prevent hydrolysis and the like. Examples of surface treatment methods include (i) coating with an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, titanium hydroxide, bismuth oxide, bismuth hydroxide, bismuth nitrate, or a mixture thereof; (ii) coating with a mixture of an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, titanium hydroxide, and a thermosetting resin such as phenolic resin; and (iii) double coating with a thermosetting resin such as phenolic resin on top of a film of an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, titanium hydroxide.

[0318] Examples of the aforementioned organophosphorus compounds include general-purpose organophosphorus compounds such as phosphate ester compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phospholane compounds, and organic nitrogen-containing phosphorus compounds, as well as cyclic organophosphorus compounds such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,5-dihydrooxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(2,7-dihydrooxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and derivatives obtained by reacting these with compounds such as epoxy resins and phenolic resins.

[0319] The amount of the phosphorus-based flame retardant is appropriately selected depending on the type of phosphorus-based flame retardant, the other components of the resin composition, and the desired degree of flame retardancy. For example, in 100 parts by mass of the epoxy resin composition according to this embodiment, when red phosphorus is used as a non-halogen-based flame retardant, it is preferable to blend it in the range of 0.1 to 2.0 parts by mass. Similarly, when using the organophosphorus compound, it is preferable to blend it in the range of 0.1 to 10.0 parts by mass, and more preferably in the range of 0.5 to 6.0 parts by mass.

[0320] When using the aforementioned phosphorus-based flame retardant, hydrotalcite, magnesium hydroxide, boron compounds, zirconium oxide, black dyes, calcium carbonate, zeolite, zinc molybdate, activated carbon, etc., may be used in combination with the phosphorus-based flame retardant.

[0321] Examples of the nitrogen-based flame retardants include triazine compounds, cyanuric acid compounds, isocyanuric acid compounds, and phenothiazines, among which triazine compounds, cyanuric acid compounds, and isocyanuric acid compounds are preferred.

[0322] Examples of the triazine compounds include melamine, acetoganamine, benzoguanamine, melon, melam, succinoguanamine, ethylenedimelamine, polyphosphate melamine, triguanamine, etc., as well as (1) sulfate aminotriazine compounds such as guanylmelamine sulfate, melem sulfate, and melam sulfate; (2) co-condensates of phenols such as phenol, cresol, xylenol, butylphenol, and nonylphenol, and melamines such as melamine, benzoguanamine, acetoganamine, and formuanamine, and formaldehyde; (3) mixtures of the co-condensates of (2) and phenol resins such as phenol-formaldehyde condensates; and (4) the above (2) and (3) further modified with tung oil, isomerized linseed oil, etc.

[0323] Examples of the cyanuric acid compound include cyanuric acid and melamine cyanurate.

[0324] The compounding amount of the nitrogen-based flame retardant is appropriately selected according to the type of the nitrogen-based flame retardant, other components of the resin composition, and the desired degree of flame retardancy. For example, in 100 parts by mass of the epoxy resin composition according to this embodiment, it is preferably compounded in the range of 0.05 to 10 parts by mass, and more preferably in the range of 0.1 part by mass to 5 parts by mass.

[0325] The silicone-based flame retardant can be used without particular limitation as long as it is an organic compound containing a silicon atom. Examples thereof include silicone oil, silicone rubber, and silicone resin. The compounding amount of the silicone-based flame retardant is appropriately selected according to the type of the silicone-based flame retardant, other components of the resin composition, and the desired degree of flame retardancy. For example, in 100 parts by mass of the resin composition containing all of the non-halogen-based flame retardant and other fillers and additives, etc., it is preferably compounded in the range of 0.05 to 20 parts by mass. When using the silicone-based flame retardant, a molybdenum compound, alumina, etc. may be used in combination.

[0326] Examples of the inorganic-based flame retardant include boron compounds and low melting point glasses.

[0327] Examples of the boron compound include zinc borate, zinc metaborate, barium metaborate, boric acid, borax, and borate ester.

[0328] Examples of the low melting point glass include Seeply manufactured by Air Brown Co., Ltd., hydrated glass SiO ２ -MgO-H ２ O, PbO-B ２ O ３ system, ZnO-P ２ O ５ -MgO system, P ２ O ５ -B ２ O ３ -PbO-MgO system, P-Sn-O-F system, PbO-V ２ O ５ [[ID=3,6]] -TeO ２ system, Al ２ O ３ -H ２ O system, lead borosilicate-based glassy compounds, etc. can be mentioned.

[0329] The amount of inorganic flame retardant to be blended is appropriately selected depending on the type of inorganic flame retardant, the other components of the resin composition, and the desired degree of flame retardancy. For example, it is preferable to blend it in the range of 0.05 to 20 parts by mass, and more preferably in the range of 0.5 to 15 parts by mass, in 100 parts by mass of the resin composition containing the non-halogenated flame retardant and all other fillers and additives.

[0330] Examples of the organometallic salt-based flame retardants include ferrocene, acetylacetonate metal complexes, organometallic carbonyl compounds, organocobalt salt compounds, organosulfonic acid metal salts, and compounds in which a metal atom and an aromatic compound and / or a heterocyclic compound are ionically bonded and / or coordinately bonded.

[0331] The amount of the organometallic salt flame retardant is appropriately selected depending on the type of organometallic salt flame retardant, the other components of the resin composition, and the desired degree of flame retardancy. For example, it is preferable to include it in an amount of 0.005 to 10 parts by mass in 100 parts by mass of the resin composition containing the non-halogenated flame retardant and all other fillers and additives.

[0332] [Filler] The epoxy resin composition according to this embodiment may contain a filler that does not belong to the conductive material (D) or the thermally expandable particles according to this embodiment. Examples of the filler include inorganic fillers and organic fillers. Examples of the inorganic filler include inorganic fine particles, and examples of those with excellent insulating properties include silica, and examples of those with excellent ultraviolet shielding properties include titanium dioxide and zinc oxide. These inorganic fine particles can be selected as appropriate depending on the application, and may be used individually or in combination of multiple types. Furthermore, since the inorganic fine particles have various properties other than those listed as examples, they can be selected as appropriate according to the application.

[0333] When using silica as the inorganic fine particles, for example, there are no particular limitations, and known silica fine particles such as powdered silica or colloidal silica can be used. Examples of commercially available powdered silica fine particles include silica fine particles manufactured by Nippon Aerosil Co., Ltd. (product names: Aerosil 50, 200), silica fine particles manufactured by AGC Inc. (product names: Sildex H31, H32, H51, H52, H121, H122), silica fine particles manufactured by Nippon Silica Industry Co., Ltd. (product names: E220A, E220), silica fine particles manufactured by Fuji Silysia Chemical Co., Ltd. (product name: SYLYSIA470), and silica fine particles manufactured by Nippon Sheet Glass Co., Ltd. (product name: SG Flake).

[0334] Furthermore, commercially available colloidal silica includes, for example, methanol silica sol manufactured by Nissan Chemical Corporation (product names: IPA-ST, MEK-ST, NBA-ST, XBA-ST, DMAC-ST, ST-UP, ST-OUP, ST-20, ST-40, ST-C, ST-N, ST-O, ST-50, ST-OL).

[0335] As the silica nanoparticles, silica nanoparticles with a modified surface may be used. For example, silica nanoparticles that have been surface-treated with a reactive silane coupling agent having a hydrophobic group, or silica nanoparticles that have been modified with a compound having a (meth)acryloyl group, are examples. Examples of commercially available powdered silica modified with a compound having a (meth)acryloyl group include silica manufactured by Nippon Aerosil Co., Ltd. (product names: Aerosil RM50, R711), and examples of commercially available colloidal silica modified with a compound having a (meth)acryloyl group include colloidal silica manufactured by Nissan Chemical Industries, Ltd. (product name: MIBK-SD).

[0336] The shape of the silica nanoparticles is not particularly limited, and spherical, hollow, porous, rod-shaped, plate-shaped, fibrous, or irregularly shaped particles can be used. The primary particle diameter is preferably in the range of 5 to 200 nm.

[0337] As the titanium dioxide nanoparticles, not only extender pigments but also ultraviolet light-responsive photocatalysts can be used, such as anatase-type titanium dioxide, rutile-type titanium dioxide, and brookite-type titanium dioxide. Furthermore, particles designed to respond to visible light by doping different elements into the crystal structure of titanium dioxide can also be used. Suitable elements for doping titanium dioxide include anionic elements such as nitrogen, sulfur, carbon, fluorine, and phosphorus, and cationic elements such as chromium, iron, cobalt, and manganese. In terms of form, powder, sol dispersed in an organic solvent or water, or slurry can be used. Examples of commercially available powdered titanium dioxide nanoparticles include Aerosil (product name: P-25) manufactured by Nippon Aerosil Co., Ltd., and titanium dioxide nanoparticles (product name: ATM-100) manufactured by Teika Co., Ltd. Examples of commercially available slurry-type titanium dioxide nanoparticles include titanium dioxide nanoparticles (product name: TKD-701) manufactured by Teika Co., Ltd.

[0338] Examples of the organic filler include polyacrylate particles, co-acryl-type polyacrylate particles, polystyrene particles, acrylic-styrene copolymer particles, polypropylene particles, polyethylene particles, and the like.

[0339] [Dispersion Medium] The epoxy resin composition according to this embodiment may use a dispersion medium to adjust the solid content and viscosity of the resin composition. The dispersion medium can be any liquid medium that does not impair the effects of this embodiment, and examples include various organic solvents and liquid organic polymers.

[0340] The organic solvents used include those described above in "Solvents used in the reaction between (a1) and (a2)". These can be used individually or in combination, but methyl ethyl ketone is preferred in terms of volatility during coating and solvent recovery.

[0341] The aforementioned liquid organic polymer is a liquid organic polymer that does not directly contribute to the curing reaction, and examples include acrylic polymers (Floren WK-20: Kyoeisha Chemical), amine salts of specially modified phosphate esters (HIPLAD ED-251: Kusumoto Chemical), and modified acrylic block copolymers (DISPERBYK2000: BYK).

[0342] [Other Compounds] The resin composition of this embodiment may contain other compounds. Examples include catalysts, polymerization initiators, inorganic pigments, organic pigments, extender pigments, clay minerals, waxes, surfactants, stabilizers, flow regulators and pulling agents, dyes, leveling agents, rheology control agents, ultraviolet absorbers, antioxidants, flame retardants, plasticizers, reactive diluents, etc., other than the conductive material (D).

[0343] A cured product can be obtained by curing the resin composition of this embodiment. Curing can be performed at room temperature or by heating. When performing thermal curing, curing may be performed in a single heating step or through a multi-stage heating process.

[0344] The epoxy resin composition according to this embodiment can also be cured using active energy rays. In this case, a photocationic polymerization initiator may be used as the polymerization initiator. As the active energy ray, visible light, ultraviolet light, X-rays, electron beams, etc., can be used.

[0345] Examples of photocationic polymerization initiators include aryl-sulfonium salts and aryl-iodonium salts. Specifically, arylsulfonium hexafluorophosphate, arylsulfonium hexafluoroantimonate, arylsulfonium tetrakis(pentafluoro)borate, and tri(alkylphenyl)sulfonium hexafluorophosphate can be used. The photocationic polymerization initiator may be used alone or in combination of two or more.

[0346] [Method for Preparing Epoxy Resin Composition] The epoxy resin composition according to this embodiment may be prepared by uniformly mixing the above-described respective components, and the method is not particularly limited. For example, it can be prepared by uniformly mixing using a pot mill, ball mill, bead mill, roll mill, homogenizer, super mill, homodisper, universal mixer, Banbury mixer, kneader, or the like.

[0347] The epoxy resin composition according to this embodiment may dissolve the epoxy resin, particularly the epoxy resin (A) and the epoxy resin (B), the conductive material (D), and, if necessary, the heterocyclic aromatic compound (C) having a tertiary amino group, and, if necessary, the glycidyl ether group-containing compound (E), the curing agent (F), and further, if necessary, the above-described heat-expandable particles, curing agent, filler, dispersion medium, resin other than the above-described various compounds that can be used in combination, in a dispersion medium such as the above-described organic solvent, or may be mixed and dispersed under solvent-free conditions (without using a solvent). It is preferable to mix and disperse under solvent-free conditions (without using a solvent). Further, the epoxy resin composition according to this embodiment may be in a state where the above-described constituent materials are uniformly mixed. At this time, it is preferable to uniformly mix using a mixer or the like. The blending ratio of each constituent material can be appropriately adjusted according to the properties such as the mechanical strength and heat resistance of the desired cured product. Also, in the production of the epoxy resin composition, the mixing order of the specific constituent materials is not particularly limited.

[0348] (Cured Product of Epoxy Resin Composition According to this Embodiment) The cured product of the epoxy resin composition according to this embodiment is obtained by curing the epoxy resin composition according to this embodiment and, if necessary, a composition containing the curing agent (F). The curing method can be appropriately selected and employed from known methods.

[0349] Since the cured product of this embodiment is cured by the epoxy resin composition according to this embodiment as described above, it can maintain good mechanical strength by exhibiting an appropriate crosslink density.

[0350] Particularly when the compound (C) is included, high compatibility between adhesiveness and disintegratability can be achieved. This is presumably because the compound (C) is unevenly distributed on the surface of the cured product. Particularly when the substrate to be adhered is a metal (e.g., iron, aluminum, etc.), it is considered that the coordination bond between the substrate surface and the compound (C) improves the adhesive strength, and the disintegratability is manifested by the dissociation of the coordination bond under external stimuli. Due to the effect of this coordination bond, not only the adhesiveness and disintegratability in the initial state are excellent, but also the adhesiveness and disintegratability are excellent after the heat resistance test.

[0351] The structure of the obtained cured product can be confirmed by infrared absorption (IR) spectrometry using Fourier transform infrared spectroscopy (FT-IR), elemental analysis, X-ray scattering method, etc.

[0352] When the epoxy resin composition according to the present embodiment contains the glycidyl ether group-containing compound (E), the cured product of the present embodiment can be obtained by using the glycidyl ether group-containing compound (E) of the present embodiment as a component of the epoxy resin composition as described above. However, an intermediate of the conjugated diene described above, which is an intermediate of the glycidyl ether group-containing compound (E), is used, and a compound capable of undergoing an addition reaction by a Diels-Alder reaction is used in combination, and in the process of curing, while forming the glycidyl ether group-containing compound (E) (while synthesizing in situ), a cured product can also be obtained.

[0353] For example, when a curing reaction is carried out in a temperature range where no Retro-Diels-Alder reaction occurs using the compound represented by the formula (1)' and a furan having a glycidyl ether group and the curing agent (F) as essential raw materials, in the process of the curing reaction, the glycidyl ether group-containing compound (E) represented by the formula (4) can be obtained, and further, as the curing reaction progresses, a cured product can be obtained. The furan compound having a glycidyl ether group that can be used at this time is the same as described above.

[0354] The epoxy resin composition according to the present embodiment and the cured product produced by the epoxy resin composition have adhesiveness and disintegratability.

[0355] The present invention will now be described in detail with reference to examples and comparative examples, but unless otherwise specified, "parts" and "%" refer to mass. The present invention is not limited thereto.

[0356] １ H and １３ C-NMR, FD-MS spectra, and GPC were measured under the following conditions.

[0357] １ H-NMR: JEOL RESONANCE "JNM-ECA600" Magnetic field strength: 600MHz Number of integrations: 32 Solvent: DMSO-d ６ Sample concentration: 30% by mass

[0358] １３ C-NMR: JEOL RESONANCE "JNM-ECA600" Magnetic field strength: 150 MHz Number of integration cycles: 320 Solvent: DMSO-d ６ Sample concentration: 30% by mass

[0359] FD-MS: JEOL Ltd. "JMS-T100GC AccuTOF" Measurement range: m / z = 50.00 to 2000.00 Rate of change: 25.6 mA / min Final current value: 40 mA Cathode voltage: -10 kV

[0360] GPC: Tosoh Corporation "HLC-8320GPC" Column: Tosoh Corporation "TSK-GEL G2000HXL" + "TSK-GEL G3000HXL" + "TSK-GEL G4000HXL" Detector: RI (Differential Refractive Index) Measurement conditions: 40℃ Mobile phase: Tetrahydrofuran Flow rate: 1 ml / min Standard: Tosoh Corporation "PStQuick A", "PStQuick B", "PStQuick E", "PStQuick F"

[0361] Scanning electron microscope (SEM): KEYENCE VE-9800. Measurement conditions: Magnification 5,000x, Acceleration voltage: 5kV.

[0362] ​​​The epoxy equivalent, viscosity, and total chlorine content of the epoxy resin were measured by the following methods: Epoxy equivalent (g / equivalent): JIS K7236 Viscosity: JIS K7233 Total chlorine content: JIS K7243-3 (single cylinder rotational viscometer method)

[0363] Examples of methods for calculating the number of repeating units include GPC molecular weight measurement and calculation from the results of appropriate instrumental analyses such as FD-MS and NMR.

[0364] (Synthesis Example 1) 210 g of diglycidyl ether of 1,12-dodecanediol (manufactured by Yokkaichi Synthetic Co., Ltd.: epoxy equivalent 210 g / equivalent) and 123.1 g of bisphenol A (hydroxyl group equivalent 114 g / equivalent) were charged into a flask equipped with a thermometer and stirrer. The mixture was heated to 140°C for 30 minutes, and then 3.4 g of 20% sodium hydroxide aqueous solution was added. The mixture was then heated to 150°C for 30 minutes, and the reaction was continued at 150°C for 16 hours. After that, sodium phosphate was added to neutralize the mixture, and the hydroxy compound (a12-1) was obtained. Mass spectrometry of this hydroxy compound (a12-1) yielded a peak at M+=771, which corresponds to the theoretical structure of m1=1, n1=12 in the structural formula (a12-1) below, thus confirming that it contains the target hydroxy compound. The phenolic hydroxyl group equivalent of this hydroxy compound (a12-1) was 1980 g / equivalent.

[0365]

[0366] (Synthesis Example 2) 210 g of the diglycidyl ether of 1,12-dodecanediol from Synthesis Example 1 and 3.1 g of 12 bisphenol A were reacted in the same manner as in Synthesis Example 1, except that 481 g of diglycidyl ether of polypropylene glycol (Nagase ChemteX "Denacol EX-931": epoxy equivalent 481 g / equivalent) and 139 g of bisphenol A were used to obtain the hydroxy compound (a12-2). Mass spectrometry of this hydroxy compound (a12-2) yielded a peak at M+=1226, which corresponds to the theoretical structure of m=1, n2=11 in the structural formula (a12-2) below, confirming that it contains the target hydroxy compound. The phenolic hydroxyl group equivalent of this hydroxy compound (a12-2) was 1560 g / equivalent, and the average value of the repeating unit m was 3.2.

[0367]

[0368] (Synthesis Example 3) In a flask equipped with a thermometer, dropping funnel, condenser, and stirrer, 198 g of the hydroxy compound (a12-1) obtained in Synthesis Example 1, 435 g of epichlorohydrin, and 115 g of n-butanol were charged and dissolved while purging with nitrogen gas. After raising the temperature to 65°C, the pressure was reduced to the pressure at which azeotropy occurred, and 6.6 g of 49% sodium hydroxide aqueous solution was added dropwise over 5 hours. Then, stirring was continued under the same conditions for 0.5 hours. During this time, the distillate that distilled out by azeotropy was separated using a Dean-Stark trap, the aqueous layer was removed, and the oil layer was returned to the reaction system while the reaction continued. After that, the unreacted epichlorohydrin was removed by vacuum distillation. 150 g of methyl isobutyl ketone and 150 g of n-butanol were added to the crude epoxy resin obtained and dissolved. Furthermore, 10 g of a 10% sodium hydroxide aqueous solution was added to this solution and reacted at 80°C for 2 hours. After that, the solution was washed three times with 50 g of water until the pH of the washing solution became neutral. Next, the system was dehydrated by azeotropy, and after microfiltration, the solvent was removed by distillation under reduced pressure to obtain the target epoxy resin (A-1). The epoxy equivalent of the obtained epoxy resin (A-1) was 2308 g / equivalent, the viscosity at 60°C was 400,000 mPa·s, and the total chlorine content was 3.4%. Mass spectrometry of this epoxy resin (A-1) yielded a peak at M+=883, which corresponds to the theoretical structure of m1=1, n1=12, p1=0, p2=0, q=1 in the following structural formula (A-1), thus confirming that it contains the target epoxy resin (A-1).

[0369]

[0370] (Synthesis Example 4) In a flask equipped with a thermometer, dropping funnel, condenser, and stirrer, 156 g of the hydroxy compound (a12-2) obtained in Synthesis Example 2, 644 g of epichlorohydrin, and 147 g of n-butanol were added and dissolved while purging with nitrogen gas. After raising the temperature to 65°C, the pressure was reduced to the pressure at which azeotropy occurred, and 10 g of 49% sodium hydroxide aqueous solution was added dropwise over 5 hours. Next, stirring was continued under the same conditions for 0.5 hours. During this time, the distillate that distilled out by azeotropy was separated using a Dean-Stark trap, the aqueous layer was removed, and the oil layer was returned to the reaction system while the reaction continued. After that, the unreacted epichlorohydrin was removed by vacuum distillation. 200 g of methyl isobutyl ketone and 100 g of n-butanol were added to the obtained crude epoxy resin and dissolved. Furthermore, 15 g of a 10% sodium hydroxide aqueous solution was added to this solution and reacted at 80°C for 2 hours. After that, the solution was washed three times with 100 g of water until the pH of the washing solution became neutral. Next, the system was dehydrated by azeotropy, and after microfiltration, the solvent was removed under reduced pressure to obtain epoxy resin (A-2). The epoxy equivalent of the obtained epoxy resin (A-2) was 1820 g / equivalent, the viscosity at 60°C was 10000 mPa·s, and the total chlorine content was 3.1%. Mass spectrometry of the epoxy resin (A-2) yielded a peak at M+=1336, which corresponds to the theoretical structure of m=1, n2=11, p1=0, p2=0, q=1 in the following structural formula (A-2), confirming that the epoxy resin (A-2) was present.

[0371]

[0372] (Synthesis Example 5) In a flask equipped with a thermometer, stirrer, and condenser, 35.8 g of 1,6'-bismaleimide-(2,2,4-trimethyl)hexane (manufactured by Yamato Chemical Industries, Ltd., trade name: BMI-TMH), 30.8 g of furfurylglycidyl ether (manufactured by Kanto Chemical Co., Ltd.), and 80 g of toluene were charged. After purging with nitrogen, the mixture was reacted at 60°C for 12 hours. Subsequently, toluene was removed by vacuum distillation to obtain the glycidyl ether group-containing compound (E-1). The glycidyl ether group-containing compound (E-1) was confirmed to contain the target product, the glycidyl ether group-containing compound (E-1), as a peak with M+ = 626 was obtained by mass spectrometry. The epoxy equivalent was 331 g / equivalent.

[0373]

[0374] (Synthesis Example 6) The reaction was carried out in the same manner as in (Synthesis Example 5), except that 35.8 g of 1,6'-bismaleimide-(2,2,4-trimethyl)hexane (manufactured by Yamato Chemical Industries, Ltd., trade name: BMI-TMH) from (Synthesis Example 5) was replaced with 40.3 g of 4,4'-diphenylmethanebismaleimide (manufactured by Yamato Chemical Industries, Ltd., trade name: BMI-1000), to obtain a glycidyl ether group-containing compound (E-2). The mass spectrum of the glycidyl ether group-containing compound (E-2) showed a peak with M+ = 666, confirming that it contained the target product, the glycidyl ether group-containing compound (E-2). The epoxy equivalent was 351 g / equivalent.

[0375]

[0376] <Preparation of adhesive, evaluation of adhesive strength and disassembly properties> Using the formulations in Table 1 (numbers in the table are based on mass), each compound was uniformly mixed in a mixer (Awatori Rentaro ARV-200, manufactured by Thinky Co., Ltd.) to obtain a resin composition.

[0377] The resin composition was applied to one of two cold-rolled steel sheets (manufactured by TP Giken Co., Ltd., trade name: SPCC-SD, 0.5 mm × 25 mm × 145 mm). A 1-mm silicon tube was used as a spacer, and the other SPCC-SD was bonded (bonding area: 25 mm × 15 mm). This was heat-cured at a certain temperature to obtain a shear test piece. The adhesiveness was evaluated by performing a tensile shear test using the test piece. The test was conducted according to JIS K 6850, and the maximum point stress at a measurement environment of 23°C was compared. Initial adhesiveness: The shear test was performed on the prepared test piece without any special treatment. Adhesiveness after energization: The prepared test piece was energized at a predetermined voltage and time, and after further cooling the base material to room temperature, the shear test was conducted. From 1 V to 10 V, the voltage was held for 5 minutes at each voltage and then increased by 1 V each time. When the bonded piece peeled off (or became insulated), it was stopped there. When it did not peel off (become insulated), the energization was stopped after 5 minutes at 10 V.

[0378] <Observation of phase separation structure>A cross-section of the resin cured product was prepared with an ultramicrotome, and the phase separation structure was observed. The observation method was carried out using a scanning electron microscope (SEM). By SEM observation, the presence or absence of the phase separation structure in the cured product can be confirmed. When the cured product has a phase separation structure and the structure forms a sea-island structure, the particle size of the island phase was measured. Regarding the average value of the particle size, 50 island phases were randomly extracted from the island phases within a field of view of 200 μm × 260 μm to measure the particle size, and the average particle size was obtained. Also, from AFM observation, the relative hardness distribution of the sea phase and the island phase can be confirmed.

[0379]

[0380] The ingredients listed in the table are as follows: A-1: Epoxy resin obtained in Synthesis Example 3 A-2: Epoxy resin obtained in Synthesis Example 4 EPICLON 850-S: Bisphenol A type liquid epoxy resin (manufactured by DIC Corporation, epoxy equivalent 187 g / equivalent) SIZ: Imidazole (manufactured by Shikoku Chemicals Co., Ltd.) 1-MZ: 1-methylimidazole (manufactured by Tokyo Chemical Industries, Ltd.) GC160 50N: Expanded graphite (manufactured by Graphtec International Corporation) GC180 60N: Expanded graphite (manufactured by Graphtec International Corporation) EC600JD: Ketjenblack (manufactured by Lion Specialty Chemicals Co., Ltd.) DTA: Diethylenetriamine (manufactured by Kanto Chemical Co., Ltd.) DICY: Dicyandiamide (manufactured by Mitsubishi Chemical Corporation, "DICY7") E-1: Glycidyl ether group-containing compound obtained in Synthesis Example 5 E-2: Glycidyl ether group-containing compound obtained in Synthesis Example 6

Claims

1. A method for dismantling an adhesive body in which base material A and base material B are joined via an adhesive layer made of a cured epoxy resin composition, wherein the adhesive layer contains a conductive material (D), and the method for dismantling an adhesive body includes a step of applying an electric current to the adhesive body.

2. The method for dismantling an adhesive body according to claim 1, wherein the adhesive layer has a phase separation structure.

3. The method for disassembling the adhesive body according to claim 2, wherein the phase separation structure is obtained by containing an epoxy resin (A) represented by the following general formula (1) and having an epoxy equivalent of 500 to 10,000 g / equivalent, and an epoxy resin (B) having an epoxy equivalent of 100 to 300 g / equivalent. [In formula (1), each Ar is independently a structure having an unsubstituted or substituted aromatic ring, X is a structural unit represented by the following general formula (2), and Y is a structural unit represented by the following general formula (3). [In formulas (2) and (3), Ar is the same as described above, and R １ , R ２ are each independently a hydrogen atom, a methyl group or an ethyl group, R' is a divalent hydrocarbon group having 2 to 12 carbon atoms, and R ３ , R ４ , R ７ , R ８ are each independently a hydroxyl group, a glycidyl ether group or a 2-methylglycidyl ether group, and R ５ , R ６ , R ９ , R １０ are each independently a hydrogen atom or a methyl group, n1 is an integer of 4 to 16, and n2 is an average value of repeating units and is 2 to 30. ] R １１ , R １２ are each independently a glycidyl ether group or a 2-methylglycidyl ether group, and R １３ , R １４ are each independently a hydroxyl group, a glycidyl ether group or a 2-methylglycidyl ether group, and R １５ , R １６ are a hydrogen atom or a methyl group, and m1, m², p1, p2, q are average values of repetition, m1 and m² are each independently 0 to 25 and m1 + m² ≥ 1, p1 and p2 are each independently 0 to 5, and q is 0.5 to 5. However, the bond between X represented by the general formula (2) and Y represented by the general formula (3) may be random or block, and the total number of each structural unit X and Y present in one molecule is m1 and m², respectively. ] 4. The method for dismantling an adhesive body according to claim 3, wherein the mass ratio (A):(B) of the epoxy resin (A) to the epoxy resin (B) is 90:10 to 10:

90.

5. The method for dismantling an adhesive according to claim 1, wherein the epoxy resin composition further comprises a heterocyclic aromatic compound (C) having a tertiary amino group.

6. The method for dismantling an adhesive according to claim 5, wherein the heterocyclic aromatic compound (C) having a tertiary amino group is at least one compound selected from the group consisting of imidazole compounds and pyridine compounds having a tertiary amino group.

7. The method for dismantling an adhesive according to claim 5, wherein the heterocyclic aromatic compound (C) having a tertiary amino group is at least one compound selected from the group consisting of imidazole, 1-methylimidazole, 2-ethyl-4-methylimidazole, and 4-dimethylaminopyridine.

8. The method for dismantling an adhesive body according to claim 5, wherein the proportion of the heterocyclic aromatic compound (C) having a tertiary amino group used is in the range of 2 to 20 parts by mass with respect to 100 parts by mass of the total of the epoxy resin (A) and the epoxy resin (B).

9. The method for dismantling an adhesive body according to claim 1, wherein the conductive material (D) is a composite material containing one or more elements selected from the group consisting of carbon, metal, or metal oxide.

10. The method for dismantling an adhesive according to claim 1, wherein the average particle size of the conductive material (D) is in the range of 0.1 to 500 μm.

11. The method for dismantling an adhesive body according to claim 1, wherein the proportion of the conductive material (D) used is within the range of 3 to 40 parts by mass with respect to 100 parts by mass of the total of the epoxy resin (A) and the epoxy resin (B).

12. The method for dismantling an adhesive body according to claim 1, wherein the current in the energizing step is direct current or alternating current of 20 kHz or less.

13. The method for dismantling an adhesive body according to claim 1, wherein the voltage applied in the energizing step is 24V or less.

14. The method for dismantling an adhesive according to claim 1, wherein the epoxy resin composition further comprises a glycidyl ether group-containing compound (E), the glycidyl ether group-containing compound (E) is a compound in which a structural unit V having one or more glycidyl ether groups and a structural unit W different from the structural unit V are linked in a V-W-V manner, and the structural unit V and the structural unit W are linked by a reversible bond formed by a Diels-Alder reaction between a furan structure and a maleimide structure.

15. The method for dismantling an adhesive according to claim 14, wherein the glycidyl ether group-containing compound (E) is a compound represented by the following general formula (4) and having a molecular weight of less than 1000. [In equation (4), m3 is an integer between 1 and 4. Z １ This is given by the following equation (5), Z ３ The structure is one of the structures represented by the following formula (6), and each of the multiple structures in a single molecule may be the same or different. [The aromatic ring in formula (5) may be unsubstituted or substituted, and * represents a bond point. G is a glycidyl group or a 2-methylglycidyl group.] (In formula (6), R'' is independently a hydrogen atom, a methyl group, or an ethyl group; w1 is an integer from 1 to 30; w2 is the average value of the number of repetitions, from 0.5 to 8; w3 is the average value of the number of repetitions, from 0.5 to 6; and * represents a bond point.) 16. The method for dismantling an adhesive body according to claim 1, wherein the epoxy resin composition further comprises a curing agent (F).

17. The method for disassembling an adhesive body according to claim 3, wherein the phase separation structure comprises resin particles having an average particle diameter of 10 nm to 100 μm and a matrix surrounding them, the resin particles contain a cured product of the epoxy resin (A), and the matrix contains a cured product of the epoxy resin (B).

18. The method for disassembling an adhesive body according to claim 3, wherein the phase separation structure comprises resin particles having an average particle diameter of 10 nm to 100 μm and a matrix surrounding them, the resin particles contain a cured product of the epoxy resin (B), and the matrix contains a cured product of the epoxy resin (A).

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