Epoxy resin composition, cured product thereof, and dismantling method

Abstract

Provided are: an epoxy resin composition that obtains a cured product having excellent adhesiveness, flexibility and disassembling properties; a cured product thereof; and a disassembling method using a disassemblable adhesive material. An epoxy resin composition according to the present embodiment contains: an epoxy resin (A) having a specific structure and having an epoxy equivalent weight of 500-10,000 g / eq, an epoxy resin (B) having an epoxy equivalent weight of 100-300 g / eq, a glycidyl ether group-containing compound (C) having a molecular weight of less than 1,000, and thermally expandable particles (D). The glycidyl ether group-containing compound (C) has a specific structure having a reversible bond.

Description

[Technical Field]

[0001] The present invention relates to an epoxy resin composition, a cured product thereof, and a demolition method using a demolition adhesive material. This application claims priority based on Japanese Patent Application No. 2023-195033, filed in Japan on November 16, 2023, and the contents of that application are incorporated herein by reference. [Background technology]

[0002] Cured products obtained from epoxy resins exhibit excellent heat resistance, mechanical strength, electrical properties, and adhesiveness, making them indispensable materials in various fields such as electrical and electronics, paints, and adhesives.

[0003] On the other hand, cured products using thermosetting resins such as epoxy resins have low long-term reliability. For example, if a cured epoxy resin product undergoes oxidative degradation, cracks may occur.

[0004] Furthermore, cured products obtained by curing thermosetting resins such as epoxy resins are insoluble in solvents and do not dissolve even at high temperatures. Because of this, they have poor recyclability and reusability, and the cured products become waste after use. Therefore, reducing waste and mitigating the environmental impact are challenges.

[0005] Therefore, there is a need to address challenges such as extending the lifespan and reducing waste in cured products using epoxy resins, and it is considered that imparting easy dismantling properties to the cured product is an effective way to solve these problems.

[0006] For example, as a technology for weight reduction of automobiles, airplanes, etc., it is essential to improve the performance of adhesives for structural materials. On the other hand, achieving high adhesive performance also contributes to the production of products that are difficult to recycle, and the dismantling and reusability after use are limited. Against the backdrop of the increasing environmental awareness in recent years, it is also important to develop adhesives that can be easily peeled off after the usage period while maintaining high adhesive performance. Under such circumstances, the development of easily dismantled adhesives has been actively carried out. Generally, the thermal melting of thermoplastic resins is often utilized. In recent years, however, technologies have also been proposed in which a thermally expandable material or a thermally decomposable compound is premixed with a thermosetting resin, and the adhesive force is reduced by applying mainly thermal energy after use to cause peeling (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0009] As a result of diligent research, the inventors discovered that the above problem can be solved by using a glycidyl ether group-containing compound (C) having a specific structure and an epoxy resin having a specific structure, and by incorporating thermally expandable particles into the resin composition, thus completing the invention.

[0010] In other words, the present invention encompasses the following aspects. [1] An epoxy resin (A) with an epoxy equivalent of 500 to 10,000 g / eq represented by the following general formula (1), Epoxy resin (B) with an epoxy equivalent of 100-300 g / eq, A glycidyl ether group-containing compound (C) represented by the following general formula (4) and having a molecular weight of less than 1000, An epoxy resin composition characterized by containing thermally expandable particles (D). [ka] [In formula (1), each Ar independently has a structure that is either unsubstituted or has a 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). [ka] [In equations (2) and (3), Ar is the same as described above, R1 and R2 are independently a hydrogen atom, a methyl group, or an ethyl group. R' is a divalent hydrocarbon group with 2 to 12 carbon atoms. R3, R4, R7, and R8 are each independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group. R5, R6, R9, R10 is independently a hydrogen atom or a methyl group, n1 is an integer from 4 to 16, n2 is an average value of repeating units and is from 2 to 30. R 11 and R 12 are each independently a glycidyl ether group or a 2-methylglycidyl ether group, R 13 and R 14 are each independently a hydroxyl group, a glycidyl ether group or a 2-methylglycidyl ether group, R 15 and R 16 are a hydrogen atom or a methyl group, m1, m2, p1, p2, q are average values of repetition, m1 and m2 are each independently from 0 to 25 and m1 + m2 ≥ 1, p1 and p2 are each independently from 0 to 5, q is from 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.

Chemical formula

Chemical formula

Chemical formula

[10] A heat-resistant component containing the cured product described in [8].

[11] A disassemblable adhesive material containing the epoxy resin composition described in any of [2] to [7].

[12] A dismantling method using the dismantling adhesive material described in

[11] , A bonding step of attaching the disassemblable adhesive material to the surface of the adherend and joining it to the adherend; a curing step of curing the disassemblable adhesive material and obtaining a cured product; A heat treatment step is performed on the cured product to thermally dissociate the reversible bonds contained in the general formula (4) derived from the glycidyl ether group-containing compound (C) and to expand the thermally expandable particles (D), A dismantling method comprising a dismantling step of dismantling the adherend and the hardened material.

[13] The demolition method according to

[12] , further comprising a cooling step of cooling the hardened material after heat treatment to room temperature, after the heat treatment step and before the demolition step. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an epoxy resin composition that exhibits excellent adhesion, flexibility, and decomposability of the cured product. [Modes for carrying out the invention]

[0012] Next, embodiments for carrying out the present invention will be described in detail. The present invention is not limited to the following embodiments, and it should be understood that appropriate design changes, improvements, etc., can be made based on the ordinary knowledge of those skilled in the art, without departing from the spirit of the invention.

[0013] (Epoxy resin composition) An epoxy resin composition as one embodiment of the present invention (this embodiment) is characterized by containing an epoxy resin (A) represented by the above general formula (1) with an epoxy equivalent of 500 to 10,000 g / eq, an epoxy resin (B) with an epoxy equivalent of 100 to 300 g / eq, a glycidyl ether group-containing compound (C) represented by the above general formula (4) and having a molecular weight of less than 1000, and thermally expandable particles (D). The epoxy resin composition of this embodiment preferably further comprises a compound (I) that is reactive with the glycidyl ether group-containing compound (C). The epoxy resin composition of this embodiment may optionally contain other epoxy resins other than the epoxy resin (A), epoxy resin (B), and glycidyl ether group-containing compound (C) according to this embodiment. The epoxy resin composition of this embodiment may also optionally contain a curing accelerator, other thermosetting resins or thermoplastic resins, non-halogenated flame retardants, fillers not belonging to the thermally expandable particles (D) according to this embodiment, or a dispersion medium. The following provides a detailed explanation of each component.

[0014] [Epoxy resin (A)]

[0015] The epoxy resin (A) contained in the epoxy resin composition of this embodiment is an epoxy resin with an epoxy equivalent of 500 to 10,000 g / eq, represented by the following general formula (1). [ka] [In formula (1), each Ar independently has a structure that is either unsubstituted or has a 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). [ka] [In equations (2) and (3), Ar is the same as described above, R1 and R2 are independently a hydrogen atom, a methyl group, or an ethyl group. R' is a divalent hydrocarbon group with 2 to 12 carbon atoms. R3, R4, R7, and R8 are each independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group. R5, R6, R9, R 10 Each of these is independently a hydrogen atom or a methyl group. n1 is an integer between 4 and 16. n² is the average value of the repetition unit, ranging 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 repeated average values, m1 and m2 are independently between 0 and 25, and m1 + m2 ≥ 1. p1 and p2 are independently between 0 and 5. q is between 0.5 and 5. However, the bonding between X represented by general formula (2) and Y represented by 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.

[0016] The above structure contains structural unit X represented by general formula (2) and / or structural unit Y represented by general formula (3). 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 provided by the alkylene chains allows it to follow the thermal expansion of the substrate when used as an adhesive, and the polyether chains have the effect of lowering the viscosity of the epoxy resin (A) itself, thus contributing to improved coating and processability of the epoxy resin composition.

[0017] 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.

[0018] In the general formula (1) representing epoxy resin (A), the Ar in the general formula (2) representing structural unit X, and the Ar in the general formula (3) representing structural unit Y, all have an unsubstituted or substituted aromatic ring. Furthermore, this aromatic ring is not particularly limited and examples include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, and fluorene ring.

[0019] Among these, Ar is preferably one of the structures represented by the following structural formula (ar).

[0020] [ka] [The aromatic ring in formula (ar) may be substituted or unsubstituted, and * represents a bonding site.]

[0021] Furthermore, structures represented by the following formula can also be considered as Ar.

[0022] [ka] (In the formula, the aromatic ring may be substituted or unsubstituted, n3 = 1 to 4, and * represents a bonding point.)

[0023] The aromatic ring of Ar may be substituted or unsubstituted. 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 preferably unsubstituted.

[0024] The following structures of Ar are particularly preferred. * indicates a bond point.

[0025] [ka]

[0026] Particularly preferred structures for substituted Ar include the following structures. * represents a bond point.

[0027] [ka] In the formula, R represents a hydrogen atom or a methyl group.

[0028] In the structural unit X represented by the general formula (2) above, the repeating unit n1 is an integer between 4 and 16. When n1 is 4 or greater, the adhesive strength is improved and the deformation mode of the cured product becomes elastic deformation. Furthermore, when n1 is 16 or less, the decrease in crosslinking density can be suppressed. Preferably, it is between 4 and 15, and more preferably between 6 and 12.

[0029] In the structural unit X represented by the general formula (2) above, R 1 , R 2 Each of these is independently a hydrogen atom, a methyl group, or an ethyl group, and R 3 , R 4 Each of these is independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group, R 5 , R 6 Each of these is independently either a hydrogen atom or a methyl group.

[0030] Among these, R 3 , R 4 Preferably, it is a hydroxyl group, R 5 , R 6 It is preferable that it is a hydrogen atom.

[0031] 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. Preferably it is between 2 and 25, and more preferably between 4 and 20.

[0032] 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 becomes elastic deformation. Preferably, R' is a divalent hydrocarbon group having 2 to 6 carbon atoms.

[0033] 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, and aralkylene groups (divalent groups having an alkylene group and an arylene group).

[0034] 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 alkylene 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.

[0035] Among these, ethylene groups, propylene groups, and tetramethylene groups are preferred from the viewpoint of the ease of obtaining raw materials, the viscosity of the resulting epoxy resin (A), and the balance of flexibility when cured.

[0036] 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, and R 9 , R 10 Each of these is independently a hydrogen atom or a methyl group. 7 , R 8 Preferably, it is a hydroxyl group, R 9, R 10 Preferably, the atom is a hydrogen atom.

[0037] 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.

[0038] 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 R is a hydrogen atom or a methyl group, and p1, p2, and q are the average values ​​of the repeating values, where p1 and p2 are independently between 0 and 5, and q is between 0.5 and 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.

[0039] Furthermore, the epoxy equivalent of the epoxy resin (A) used in this embodiment is 500 to 10,000 g / eq. This range provides an excellent balance between the flexibility and crosslink density of the resulting cured product. From the viewpoint of ease of handling and for an even better balance between flexibility and crosslink density, a range of 600 to 8,000 g / eq is preferred, and a range of 800 to 5,000 g / eq is more preferred.

[0040] Among the epoxy resins (A) in this embodiment, one example that has both structural unit X and structural unit Y in a single molecule is a resin with the following structural formula.

[0041] [ka]

[0042] [ka]

[0043] [ka]

[0044] [ka]

[0045] [ka]

[0046] [ka]

[0047] [ka]

[0048] [ka]

[0049] [ka]

[0050] [ka]

[0051] [ka]

[0052] [ka]

[0053] In the above structural formulas (A-1) to (A-12), ran represents a random bond, G is a glycidyl group, R' represents a divalent hydrocarbon group with 2 to 12 carbon atoms, n1 is an integer from 4 to 16, n2 is the average value of the repeating unit from 2 to 30, m1, m2, p1, p2, and q are the average values ​​of the repeats, m1 and m2 are independently from 0.5 to 25, p1 and p2 are independently from 0 to 5, and q is from 0.5 to 5. However, each repeating unit within a repeating unit may be the same or different.

[0054] Among the structural formulas described above, it is most 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 a superior balance of physical properties in the resulting cured product.

[0055] 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.

[0056] [ka]

[0057] [ka]

[0058] [ka]

[0059]

change

[0060]

change

[0061]

change

[0062]

change

[0063]

change

[0064]

change

[0065]

change

[0066]

change

[0067]

change

[0068] In the above structural formulas (A-13) to (A-24), G is a glycidyl group, n1 is an integer from 4 to 16, m1, p1, p2, and q are the average values ​​of the repeats, m1 is from 0.5 to 25, p1 and p2 are independently from 0 to 5, and q is from 0.5 to 5. However, each repeating unit within a repeating unit may be the same or different.

[0069] Among the structural formulas described above, 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 a superior balance of physical properties for the resulting cured product.

[0070] 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.

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080] [ka]

[0081] [ka]

[0082] [ka]

[0083] In the above structural formulas (A-25) to (A-36), G is a glycidyl group, R' is a divalent hydrocarbon group with 2 to 12 carbon atoms, n2 is the average value of the repeating units from 2 to 30, m2, p1, p2, and q are the average values ​​of the repeats, m2 is from 0.5 to 25, p1 and p2 are independently from 0 to 5, and q is from 0.5 to 5. However, each repeating unit within a repeating unit may be the same or different.

[0084] Among the structural formulas described above, it is most 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 a superior balance of physical properties for the resulting cured product.

[0085] <Method for manufacturing epoxy resin (A)> The method for producing the epoxy resin (A) according to this embodiment is not particularly limited, but for example, a method in which a diglycidyl ether (a1) of a dihydroxy compound having an alkylene chain and a polyether chain is reacted with an aromatic hydroxy compound (a2) in a molar ratio (a1) / (a2) in the range of 1 / 1.01 to 1 / 5.0 to obtain a hydroxy compound [corresponding to a precursor or intermediate of epoxy resin (A)], and then reacts it with an epihalohydrin (a3) ​​is preferred in terms of ease of obtaining raw materials and the ease of the reaction.

[0086] The product obtained in the reaction in which a diglycidyl ether (a1) of a dihydroxy compound having an alkylene chain and a polyether chain is reacted with an aromatic hydroxy compound (a2) to obtain a hydroxy compound 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 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 of this embodiment containing the obtained 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 in the range of 0.1 to 30% by mass.

[0087] 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 can be used. Among these, alkaline aqueous extraction is preferred in terms of efficiency because it does not involve thermal degradation, and in this case, any organic solvent that does not mix with water, such as toluene or methyl isobutyl ketone, can be used to dissolve the target substance. Furthermore, the use of methyl isobutyl ketone is particularly preferred from the viewpoint of solubility with the target substance.

[0088] The diglycidyl ether (a1) of the dihydroxy compound having the alkylene chain and polyether chain is not particularly limited. For example, diglycidyl ethers having alkylene 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, 1,13-tridecanediol 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 also contain organochlorine such as 1-chloromethyl-2-glycidyl ether (chloromethyl derivative) represented by the structure shown below. These diglycidyl ethers may be used individually or in combination of two or more types.

[0089] [ka]

[0090] Among these, 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 are preferred because they offer an excellent balance between the flexibility and heat resistance of the resulting cured product.

[0091] Furthermore, by simultaneously reacting the aforementioned diglycidyl ether having an alkylene chain and the diglycidyl ether having a polyether chain with an aromatic hydroxy compound (a2), a hydroxy compound having both structural unit X and structural unit Y can be obtained. By further reacting this with an epihalohydrin (a3), an epoxy resin (A) having both structural unit X and structural unit Y can be obtained.

[0092] The aromatic hydroxy compound (a2) is not particularly limited and includes, 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; dihydroxynaphthalenes such as 1,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, and 2,6-dihydroxynaphthalene; tetrafunctional phenols such as 1,1'-methylenebisu(2,7-naphthalenediol), 1,1'-binaphthalene-2,2',7,7'-tetraol, and 1,1'-oxybisu(2,7-naphthalenediol) obtained by coupling reactions of dihydroxynaphthalenes; and bis(4-H Bisphenols such as hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, and 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, 3,3',5,5'-tetramethylbiphenyl-2,2'-diol, 3,3',5,5'-tetramethylbiphenyl-4,4'-diol, 5-methyl-(1,1'-biphenyl)-3,4'-diol, 3'-methyl-(1,1'-biphenyl)-3,4'-diol, 4'-methyl-(1,1'-biphenyl)-3,Examples include biphenols such as 4'-diols, alicyclic structure-containing phenols such as polyadditives of phenol and dicyclopentadiene, and polyadditives of phenol and terpene compounds, naphthols such as bis(2-hydroxy-1-naphthyl)methane and bis(2-hydroxy-1-naphthyl)propane, and so-called Zyloc-type phenolic resins which are condensation reaction products of phenol and phenylene dimethyl chloride or biphenylene dimethyl chloride. These may be used individually or in combination of two or more. Furthermore, compounds in which a methyl group, t-butyl group, or halogen atom is substituted as a substituent on the aromatic kernel of each of the above compounds are also included. It should be noted that the alicyclic structure-containing phenols and the Zyloc-type phenolic resins may contain not only difunctional components but also trifunctional or higher components simultaneously. In this invention, they may be used as is, or only the difunctional components may be isolated and used after purification using a column or other purification process.

[0093] Among these, bisphenols are preferred due to their excellent balance of flexibility and toughness 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 the curability and heat resistance of the cured product are important, dihydroxynaphthalenes are preferred, and 2,7-dihydroxynaphthalene is particularly preferred due to its remarkable rapid curing properties. Furthermore, when the moisture resistance of the cured product is important, it is preferable to use compounds containing an alicyclic structure.

[0094] From the viewpoint of reaction efficiency, the reaction ratio of the diglycidyl ether (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).

[0095] The reaction between the diglycidyl ether (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 DMP-30, 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, 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. Two or more of these catalysts may be used in combination. Among these, sodium hydroxide, potassium hydroxide, triphenylphosphine, and DMP-30 are preferred due to their rapid reaction and high effectiveness in reducing impurities. 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 aromatic hydroxyl groups in the aromatic hydroxy compound (a2). The form of these catalysts is also not particularly limited; they may be used in aqueous solution form or in solid form.

[0096] Furthermore, the reaction between the diglycidyl ether (a1) of the dihydroxy compound having the alkylene chain and 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 methyl cellosolve, ethyl cellosolve, toluene, xylene, methyl isobutyl ketone, dimethyl sulfoxide, propyl alcohol, and butyl alcohol. 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 can be used individually or in mixtures of several types. Solvent-free use is preferred for rapid reaction, while the use of dimethyl sulfoxide is preferred in terms of reducing impurities in the final product.

[0097] The reaction temperature for the above reaction 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.

[0098] 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 dihydrogen 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 hydroxy compound.

[0099] By using a glycidyl ether having an alkylene chain and a glycidyl ether having a polyether chain in combination, a hydroxy compound having both structural unit X and structural unit Y can be obtained. In this case, a preferred structure is, for example, a compound represented by the following structural formula.

[0100] [ka]

[0101] [ka]

[0102] [ka]

[0103] [ka]

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109] [ka]

[0110] [ka]

[0111] [ka]

[0112] In each of the above structural formulas, ran represents a random bond, R' is a divalent hydrocarbon group with 2 to 12 carbon atoms, n1 is an integer from 4 to 16, n2 is the average value of the repeating units from 2 to 30, and m1 and m2 are the average values ​​of the repeats, independently from 0.5 to 25. However, each repeating unit within a repeating unit may be identical or different.

[0113] Furthermore, by using the glycidyl ether having the alkylene chain as a raw material, a hydroxy compound having the structural unit X can be obtained. In this case, a preferred structure is, for example, a compound represented by the following structural formula.

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] [ka]

[0119] [ka]

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] [ka]

[0124] [ka]

[0125] [ka]

[0126] In each of the above structural formulas, n1 is an integer between 4 and 16, and m1 is the average value of the repeats, between 0.5 and 25.

[0127] Furthermore, by using a glycidyl ether having the polyether chain as a raw material, a hydroxy compound having the structural unit Y can be obtained. In this case, a preferred structure is, for example, a compound represented by the following structural formula.

[0128]

change

[0129]

change

[0130]

change

[0131]

change

[0132]

change

[0133]

change

[0134]

change

[0135]

change

[0136]

change

[0137]

change

[0138]

change

[0139] [Chemical formula]

[0140] In each of the above structural formulas, R' is a divalent hydrocarbon group having 2 to 12 carbon atoms, n2 is an average value of repeating units and is 2 to 30, and m2 is an average value of repetitions and is 0.5 to 25. However, each repeating unit present in the repeating unit may be the same or different.

[0141] In the method for producing the epoxy resin (A), there is no particular limitation on the method of the glycidyl etherification reaction of the obtained precursor (intermediate) hydroxy compound. Examples thereof include a method of reacting a phenolic hydroxyl group with epihalohydrin, a method of olefinating a phenolic hydroxyl group, and a method of oxidizing the carbon-carbon double bond of the olefin with an oxidizing agent. Among these, the method using epihalohydrin (a3) is preferable because raw materials are easily available and the reaction is easy.

[0142] As a method using epihalohydrin (a3), for example, 0.3 to 100 moles of epihalohydrin (a3) is added to 1 mole of the aromatic hydroxyl group of the hydroxy compound obtained above, and 0.9 to 2.0 moles of a basic catalyst per 1 mole of the aromatic hydroxyl group of the hydroxy compound is added to this mixture all at once or gradually, and the reaction is carried out at a temperature of 20 to 120 °C for 0.5 to 10 hours. The larger the amount of epihalohydrin (a3) added, the closer the obtained epoxy resin is to the theoretical structure, and the formation of secondary hydroxyl groups caused by the reaction between unreacted aromatic hydroxyl groups and epoxy groups can be suppressed. From this perspective, it is preferably in the range of 2.5 to 100 equivalents. This basic catalyst may be solid or its aqueous solution may be used. When using an aqueous solution, it is added continuously, and water and epihalohydrin (a3) are continuously distilled out from the reaction mixture under reduced pressure or normal pressure, and further separated to remove water and continuously return epihalohydrin (a3) to the reaction mixture.

[0143] In industrial production, in the first batch of epoxy resin production, all of the charged epihalohydrin (a3) is new, but after the next batch, it is preferable to use a combination of epihalohydrin (a3) recovered from the crude reaction product and new epihalohydrin (a3) corresponding to the amount consumed and lost in the reaction. At this time, the epihalohydrin (a3) used is not particularly limited, and examples include epichlorohydrin, epibromohydrin, etc. Among them, epichlorohydrin is preferable because it is easily available.

[0144] Also, the basic catalyst is not particularly limited, and examples include alkaline earth metal hydroxides, alkali metal carbonates, and alkali metal hydroxides. Among them, alkali metal hydroxides are preferable because of their excellent catalytic activity in the epoxy resin synthesis reaction, and examples include sodium hydroxide, potassium hydroxide, etc. When used, these alkali metal hydroxides may be used in the form of an aqueous solution of about 10 to 55% by mass, or may be used in a solid form.

[0145] Furthermore, the reaction rate in the synthesis of epoxy resins can be increased by using organic solvents in combination. Such organic solvents are not particularly limited, but examples include ketones such as acetone and methyl ethyl ketone; alcohols such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, 1-butanol, secondary butanol, and tertiary butanol; cellosolves such as methyl cellosolve and ethyl cellosolve; ethers such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxane, and diethoxyethane; and aprotic polar solvents such as acetonitrile, dimethyl sulfoxide, and dimethylformamide. These organic solvents may be used individually, or two or more may be used in combination as appropriate to adjust their polarity.

[0146] After washing the reaction products of these glycidylation reactions with water, the unreacted epihalohydrin (a3) ​​and any organic solvents used in combination are removed by distillation under reduced pressure and heating. Furthermore, to obtain an epoxy resin with fewer hydrolyzable halogens, the obtained epoxy resin can be dissolved again in an organic solvent such as toluene, methyl isobutyl ketone, or methyl ethyl ketone, and the reaction can 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.

[0147] When using a phase transfer catalyst, the amount used is preferably in the range of 0.1 to 3.0% by mass relative to the epoxy resin used. 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 pressure and heating to obtain a high-purity epoxy resin.

[0148] [Epoxy resin (B)]

[0149] The epoxy resin (B) contained in the epoxy resin of this embodiment may have an epoxy equivalent in the range of 100 to 300 g / eq, and its structure is not limited. 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, etc., 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, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclop Examples include antadien-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, aromatic hydrocarbon formaldehyde resin-modified phenol resin 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.

[0150] Among these, it is preferable to use an epoxy resin with an epoxy equivalent of 100 to 300 g / eq from among 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. In particular, it is preferable to use an epoxy resin with an epoxy equivalent of 100 to 300 g / eq from among bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AD ​​type epoxy resin.

[0151] In this embodiment, there are no particular limitations on the ratio of epoxy resin (A) to epoxy resin (B) used, but from the viewpoint of facilitating phase separation in the cured product, 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, and particularly preferably 70:30 to 30:70. Phase separation in the cured product results in a sea-island structure, achieving both adhesiveness and stress relaxation ability in the cured product, exhibiting high adhesive strength over a wide temperature range, and reducing the molding shrinkage rate of the resin composition before and after heat curing.

[0152] [Glycidyl ether group-containing compound (C)] The glycidyl ether group-containing compound (C) contained in the epoxy resin composition of this embodiment is a glycidyl ether group-containing compound (C) represented by the following general formula (4). [ka] [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 identical or different. [ka] [In formula (5), the aromatic ring may be substituted or unsubstituted, and * represents a bond site. G is a glycidyl group or a 2-methylglycidyl group, and -OG on the naphthalene ring in the formula indicates that it may be bonded at any location.] [ka] (In formula (6), R'' is independently a hydrogen atom, a methyl group, or an ethyl group; n1 is an integer from 1 to 30; n2 is the average value of the number of repetitions, from 0.5 to 8; n3 is the average value of the number of repetitions, from 0.5 to 6; and * represents a bond point.)

[0153] The glycidyl ether group-containing compound of this embodiment is characterized in that a maleimide structure and a furan structure are linked by a reversible bond formed by a Diels-Alder reaction.

[0154] Due to this configuration, the glycidyl ether group-containing compound is incorporated into the crosslinked structure by a curing reaction based on the glycidyl ether group. On the other hand, it retains reversibility even after curing, resulting in high molecular mobility within the cured product. Therefore, if the cured product is exposed to high temperatures or subjected to impact, causing cracks or pulverization, it is easily broken at the reversible bond portions, exhibiting easy disintegration. On the other hand, since the reversible bond is reversibly reformed in the low-temperature range, including room temperature, it exhibits excellent adhesion.

[0155] To introduce a furan-type addition structure (reversible bond) into a compound via the Diels-Alder reaction described above, furan having a reactive functional group on its ring and maleimide having a reactive functional group are used. The specific reversible bond substructure can be represented by the following chemical formula. By bonding the R portion in the following formula from the maleimide-derived structure, or the various reactive functional groups on the ring of the furan-derived structure, with other structural units, a reversible bond can be introduced into the compound.

[0156] [ka]

[0157] The Diels-Alder reaction involves the addition reaction of a conjugated diene and a dienophile to form a six-membered ring. Since the Diels-Alder reaction is an equilibrium reaction, the Retro-Diels-Alder reaction occurs and dissociation (depolymerization) takes place at a given temperature. When mechanical energy such as damage or external force is applied to the resulting cured product, the C-C bond of the Diels-Alder reaction unit is preferentially cleaved because its bond energy is lower than that of a normal covalent bond. Therefore, the cured product exhibits easy disassembly. Also, the C-C bond of the Diels-Alder reaction unit shifts the equilibrium in the bonding direction in a temperature range lower than the dissociation temperature, thus forming an adduct (Diels-Alder reaction unit) again.

[0158] In the reversible bond formed by the Diels-Alder reaction, the reversible bond formed by the Diels-Alder reaction with the furan structure and the maleimide structure dissociates (depolymerizes) due to the Retro-Diels-Alder reaction occurring around 120°C. Therefore, the heating temperature required for the cured product to exhibit easy disassembly can be reduced, and it is excellent in easy disassembly for applications not suitable for high-temperature heating.

[0159] From the viewpoint of achieving both mechanical strength, flexibility, and easy disassembly when made into a cured product, the average molecular weight (Mw) of the glycidyl ether group-containing compound (C) is less than 1000.

[0160] The general formula (4) has a reversible bond formed by furan and maleimide at the terminal. It has Z1 which is any of the structures represented by the general formula (5) in the terminal furan structure in the general formula (4), and this glycidyl ether group or 2-methylglycidyl ether group contributes to the curing reaction in the epoxy resin composition described later.

[0161] Z in the formula 1This 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 one with the following structural formula is preferred from the viewpoint of ease of raw material availability and reactivity. G is a glycidyl group or a 2-methylglycidyl group.

[0162] [ka]

[0163] In the general formula (6) above, R'' is independently a hydrogen atom, a methyl group, or an ethyl group, n1 is an integer from 1 to 30, n2 is the average value of the number of repetitions, from 0.5 to 8, and n3 is the average value of the number of repetitions, from 0.5 to 6. Among these, from the viewpoint of ease of raw material availability and the mechanical properties of the resulting cured product, it is preferable that n1 is in the range of 1 to 15, n2 is in the range of 0.5 to 3, n3 is an integer from 1 to 4, and R'' is a hydrogen atom.

[0164] Examples of the glycidyl ether group-containing compound (C) in this embodiment include, but are not limited to, those shown below.

[0165] [ka]

[0166] The method for producing the glycidyl ether group-containing compound (C) of this embodiment is not particularly limited, and it can be produced stepwise using known reactions depending on the desired structure, and it can also be obtained by appropriately combining commercially available raw materials. A typical synthesis method is described below.

[0167] The compound represented by the general formula (4) has two Diels-Alder reaction units within the molecule, which are addition reaction sites formed by a Diels-Alder reaction consisting of a furan structure and a maleimide structure, as reversible bonds, and in the general formula (4), Z1 This can be obtained by using a furan compound having the structure shown.

[0168] The so-called Diels-Alder reaction, in which a conjugated diene such as a furan structure is added to a parent diene such as a maleimide structure to form a six-membered ring, is an equilibrium reaction. It is widely known that at temperatures higher than the temperature at which the addition reaction proceeds, a reverse reaction called the retro-Diels-Alder reaction occurs, in which the addition reaction site dissociates and returns to the original conjugated diene and parent diene.

[0169] Said Z 1 Examples of furan compounds having a hydroxyl group that are precursors to furan compounds having the structure shown are any of the compounds listed in the following formula. The hydroxyl group in the compound can be converted to a glycidyl ether group by known methods, such as those described in the examples.

[0170] [ka]

[0171] Among the above formulas, the compounds shown below are particularly preferred in terms of their reactivity, cured product properties, and the adhesion, flexibility, and decomposability of the resulting cured product.

[0172] [ka]

[0173] 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.

[0174] The Diels-Alder reaction can be carried out using known methods. For example, the conjugated diene compound and the parent diene compound can be mixed in equimolars, or in some cases, with an excess of one component, heated and melted, or dissolved in a solvent, and stirred at room temperature to 110°C for 1 to 24 hours. The result can then be obtained by filtration or solvent removal without further purification, or by commonly used isolation and purification methods such as recrystallization, reprecipitation, and chromatography. Note that "equomolar mixture of conjugated diene compound and parent diene compound" means that the conjugated diene structure of the conjugated diene compound and the ethylene structure of the parent diene compound are in equimolar amounts. For example, in the case of the glycidyl ether group-containing compound (C) represented by the general formula (4) above, if the furan compound as a conjugated diene compound has one conjugated diene structure per molecule, and the maleimide compound (bismaleimide) as a parent diene compound has two maleimide structures (ethylene structures) per molecule, then "equomoles of the conjugated diene compound and the parent diene compound" means "the furan compound and the maleimide compound (bismaleimide) are in a molar ratio of 2:1."

[0175] The synthesis of sites other than the reversible bond can be done by known methods. For example, by reacting a diglycidyl ether or aliphatic divinyl ether of an aliphatic dihydroxy compound with an aromatic hydroxy compound to obtain a compound having a hydroxyl group at the terminal, and then reacting it with glycidyloxyphenylmaleimide or the like to introduce a maleimide structure at the terminal, and further by performing a Diels-Alder reaction with a furan compound having a glycidyl ether group in accordance with the above, the compound represented by general formula (4) can be obtained.

[0176] Alternatively, a compound having a hydroxyl group at the terminal can be obtained, then epoxidized to form a glycidyl ether group at the terminal, and subsequently reacted with hydroxyphenylmaleimide or the like to introduce a maleimide structure at the terminal. Furthermore, by carrying out a Diels-Alder reaction with a furan compound having a glycidyl ether group in accordance with the above, the compound represented by the general formula (4) can be obtained.

[0177] Alternatively, an aromatic dihydroxy compound can be reacted with a dihalogenated alkyl compound or a dihalogenated aralkyl compound to obtain a compound having a halogenated alkyl group at the terminal, and then reacted with hydroxyphenylmaleimide or the like to introduce a maleimide structure at the terminal. Furthermore, by carrying out a Diels-Alder reaction with a furan compound having a glycidyl ether group in accordance with the above, the compound represented by the general formula (4) can be obtained.

[0178] The diglycidyl ether of the aliphatic dihydroxy compound is not particularly limited, and examples include 1,11-undecanediol diglycidyl ether, 1,12-dodecanediol diglycidyl ether, 1,13-tridecanediol 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, 2,6,10-trimethyl-1,11-undecanediol diglycidyl ether, and others, which may be used alone or in combination of two or more.

[0179] 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 because they offer an excellent balance between the flexibility and heat resistance of the resulting cured product. Most preferably, 1,12-dodecanediol diglycidyl ether, 1,13-tridecanediol diglycidyl ether, and 1,14-tetradecanediol diglycidyl ether are used.

[0180] 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 ether 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.

[0181] Among these, polyether structures or divinyl ethers with linear alkylene chains having 4 to 10 carbon atoms are preferred due to their excellent balance of flexibility and toughness in the resulting cured product. Most preferably, 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 used.

[0182] The aromatic hydroxy compounds are not particularly limited, and include, 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; dihydroxynaphthalenes such as 1,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, and 2,6-dihydroxynaphthalene; tetrafunctional phenols such as 1,1'-methylenebisu(2,7-naphthalenediol), 1,1'-binaphthalene-2,2',7,7'-tetraol, and 1,1'-oxybisu(2,7-naphthalenediol), obtained by coupling reactions of dihydroxynaphthalenes; and bis(4-H Bisphenols such as hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, and 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, 3,3',5,5'-tetramethylbiphenyl-2,2'-diol, 3,3',5,5'-tetramethylbiphenyl-4,4'-diol, 5-methyl-(1,1'-biphenyl)-3,4'-diol, 3'-methyl-(1,1'-biphenyl)-3,4'-diol, 4'-methyl-(1,1'-biphenyl)-3,Examples include biphenols such as 4'-diols, alicyclic structure-containing phenols such as polyadditives of phenol and dicyclopentadiene, and polyadditives of phenol and terpene compounds, naphthols such as bis(2-hydroxy-1-naphthyl)methane and bis(2-hydroxy-1-naphthyl)propane, and so-called Zyloc-type phenolic resins which are condensation reaction products of phenol and phenylene dimethyl chloride or biphenylene dimethyl chloride. These may be used individually or in combination of two or more. Furthermore, bifunctional phenolic compounds in which a methyl group, t-butyl group, or halogen atom is substituted as a substituent on the aromatic kernel of each of the above compounds are also examples. Note that the alicyclic structure-containing phenols and the Zyloc-type phenolic resins may contain not only bifunctional components but also trifunctional or more functional components simultaneously. They may be used as is, or the bifunctional components may be isolated and used after purification using a column or other purification process.

[0183] Among these, bisphenols are preferred due to their excellent balance of flexibility and toughness 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.

[0184] The reaction ratio of the diglycidyl ether of the aliphatic dihydroxy compound to the aromatic hydroxy compound is preferably in the range of 1 / 1.01 to 1 / 5.0 (molar ratio) of 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.

[0185] 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. Various catalysts can be used, 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 DMP-30, 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, 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 catalysts may be used in combination of two or more types. 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. The amount of these catalysts used is not particularly limited, but it is preferable to use 0.0001 to 0.01 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.

[0186] 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 include methyl cellosolve, ethyl cellosolve, toluene, xylene, methyl isobutyl ketone, dimethyl sulfoxide, propyl alcohol, and butyl alcohol. 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 can be used individually or in mixtures of several types. Solvent-free use is preferred for rapid reaction, while the use of dimethyl sulfoxide is preferred in terms of reducing impurities in the final product.

[0187] The reaction temperature for 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 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.

[0188] 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.

[0189] The reaction ratio of the aliphatic divinyl ether to the aromatic hydroxy compound is preferably in 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.

[0190] The reaction between the diglycidyl ether of the aliphatic dihydroxy compound and the aromatic hydroxy compound proceeds sufficiently without the use of a catalyst, but a catalyst may be used as appropriate in terms of selecting the starting materials and increasing 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; and Lewis acids such as aluminum chloride, iron chloride, tin chloride, gallium chloride, titanium chloride, aluminum bromide, gallium bromide, boron trifluoride ether complexes, and boron trifluoride phenol complexes. 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.

[0191] 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 include aromatic organic solvents such as benzene, toluene, and xylene; ketone organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and alcoholic organic solvents such as methanol, ethanol, and isopropyl alcohol n-butanol. 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 can be used individually or in mixtures of several types.

[0192] The reaction temperature for the above reaction is typically 50 to 150°C, and the reaction time is typically 0.5 to 10 hours. In this case, the reaction is preferably carried out under an oxygen atmosphere to prevent the self-polymerization of the vinyl ether group.

[0193] After the reaction is complete, if an organic solvent was used, it can be removed under reduced pressure heating. If a 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.

[0194] The compound having a hydroxyl group at its terminus, obtained in this manner, is reacted with glycidyloxyphenylmaleimide or the like. Sodium hydroxide, potassium hydroxide, potassium carbonate, etc., can be used as catalysts, and toluene, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, acetonitrile, dimethylformamide, etc., can be used as solvents. The reaction temperature is room temperature to 200°C, and the reaction time is 1 to 24 hours. Afterward, 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.

[0195] 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, and 1,15-pentadecanediol. Examples include ol, 1,16-hexadecanediol, 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, polyhexamethylene glycol, polyheptamethylene glycol, etc., which may be used individually or in combination of two or more types.

[0196] 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 it offers an excellent balance between the flexibility and heat resistance of the resulting cured product. The most preferred materials are polyethylene glycol, polypropylene glycol, polytetramethylene glycol, 1,12-dodecanediol, 1,13-tridecanediol, and 1,14-tetradecanediol.

[0197] 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., which may be used alone or in combination of two or more.

[0198] 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.

[0199] The reaction ratio of the aromatic dihydroxy compound to the dihalogenated alkyl compound or dihalogenated aralkyl compound is preferably in 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.

[0200] The reaction between the aromatic dihydroxy compound and the alkyl dihalide compound or 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. Two or more of these catalysts may be used in combination. 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.

[0201] Furthermore, the reaction between the aromatic dihydroxy compound and the dihalogenated alkyl compound or dihalogenated aralkyl compound can be carried out without a solvent or in the presence of an organic solvent. Examples of organic solvents that can be used include toluene, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, acetonitrile, and dimethylformamide. The amount of organic solvent used is usually 50 to 300% by mass, preferably 100 to 1000% by mass, relative to the total mass of the raw materials. These organic solvents can be used individually or in mixtures of several types.

[0202] The reaction temperature for the above-mentioned reaction is usually room temperature to 150°C, and the reaction time is usually 1 to 24 hours. From the viewpoint of reducing impurities in the final product, a reaction temperature of room temperature to 100°C is preferable.

[0203] The compound having a halogenated alkyl group at the end obtained in this way is reacted with hydroxyphenylmaleimide or the like. 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. can 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.

[0204] The intermediate of the parent diene before the Diels-Alder reaction can be represented by the following general formula (1)'.

[0205] [ka] [In the formula, n, Z 3 This is the same as above.

[0206] [Thermally expandable particles (D)] The thermally expandable particles (D) contained in the epoxy resin composition of this embodiment may be made of an inorganic material or an organic material. An example of an inorganic material is thermally expandable graphite provided in Japanese Patent Application Publication No. 2000-44219, etc. An example of an organic material is a thermally expandable microcapsule made by microencapsulating a volatile expanding agent that becomes gaseous at a temperature below its softening point, using a thermoplastic polymer as the outer shell.

[0207] Among these, it is preferable to use thermally expandable microcapsules made of organic materials, from the viewpoint of excellent uniform dispersibility and electrical insulation properties when used in epoxy resin compositions. Furthermore, among these options, it is preferable to use thermally expandable graphite from the viewpoint of heat resistance, durability, and conductivity of the expandable particles.

[0208] "Thermally expandable microcapsules" A method for manufacturing the aforementioned thermally expandable microcapsules has been provided in the past, as shown in Japanese Patent Publication No. 42-26524. However, from the viewpoint of thermally curing the epoxy resin in this embodiment, it is preferable that the method has heat resistance. Methods for manufacturing heat-resistant thermally expandable microcapsules are provided in, for example, WO99 / 46320, WO99 / 43758, and Japanese Patent Application Publication No. 2002-226620.

[0209] In other words, from the viewpoint that it is preferable for the particles to maintain their original shape without thermal expansion during the heat curing of epoxy resin, and to expand at high temperatures due to thermal energy after use, it is preferable for the outer shell polymer to be a polymer obtained by polymerizing a nitrile monomer and a monomer having a carboxyl group as essential components, which is a thermally expandable microcapsule.

[0210] 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.

[0211] As a method for obtaining the heat-resistant, thermally expandable microcapsules described above, for example, the outer shell polymer is prepared by appropriately blending a polymerization initiator with the above components. Known polymerization initiators such as peroxides and azo compounds can be used as polymerization initiators. Examples include azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, diisopropyl peroxydicarbonate, t-butyl peroxide, and 2,2'-azobis(2,4-dimethylvaleronitrile). Preferably, an oil-soluble polymerization initiator soluble in the polymerizable monomer used is used. It is desirable that the glass transition temperature (Tg) of the polymer constituting the outer shell of the thermally expandable microcapsule is 120°C or higher. The Tg of the polymer can be calculated from the Tg of each homopolymer of the constituent monomers. It can also be measured by differential scanning calorimetry (DSC), etc.

[0212] The foaming agent contained within the microcapsule is a substance that becomes gaseous below the softening point of the outer polymer shell, 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 halides, and tetraalkylsilanes, as well as compounds such as AIBN that decompose into gaseous gases upon heating. The foaming agent is selected as needed depending on the temperature range in which the capsule is to be foamed. The foaming agent can be used alone or in mixtures of two or more types.

[0213] Furthermore, fluorinated compounds such as HCF, HCFC, HFC, and HFE; 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 depletion and global warming. In actual production, conventional methods for creating thermally expandable microcapsules are generally 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.

[0214] 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. For example, the average particle size of the thermally expandable microcapsules can be measured using a particle size distribution analyzer (LA-950, manufactured by HORIBA Corporation) to measure the volume-average particle size.

[0215] "Thermally expandable graphite" A method for producing the aforementioned thermally expandable graphite is provided in Japanese Patent Publication No. 2000-44219, etc., but from the viewpoint of thermally curing the epoxy resin in this embodiment, it is preferable that the method has heat resistance. A method for producing heat-resistant thermally expandable graphite is provided in Japanese Patent Publication No. 2012-193053, etc.

[0216] Thermally expandable 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 form interlayer compounds between the graphite layers, followed by washing with water, filtering, and drying. Common acid treatment methods include those 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. Methods using only fuming nitric acid are also known.

[0217] Thermally expandable graphite is selected based on the range of its particle diameter. Therefore, commercially available thermally expandable graphite is expressed in terms of particle size rather than by diameter. Specifically, commercially available thermally expandable graphite is classified using a sieve, and its properties are indicated by specifying the sieve mesh size and the percentage of particles that pass through it.

[0218] The preferred particle size of the thermally expandable graphite used as the thermally expandable particle (D) according to this embodiment is 20 to 300 mesh, more preferably 30 to 200 mesh.

[0219] The thermally expandable particles (D) may be mixed directly with the epoxy resin (A) and epoxy resin (B), or a masterbatch in which the thermally expandable particles (D) are dispersed at a high concentration in various resins may be used and mixed with the epoxy resin (A) and epoxy resin (B).

[0220] Commercially available thermally expandable particles (D) can also be used. Examples of commercially available products include: Microspheres from 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), Microspheres from Kureha Corporation (product names: H850D, H880D, S2340D, S2640D), and Fuji Kogyo Co., Ltd. Examples include expanded graphite manufactured by [company name] (product names: EXP-50S120K, EXP-50S150), expanded graphite manufactured by Ito Graphite (product names: 953240L, 9550250), and thermally expandable graphite manufactured by Air Water (product names: 50LTE-U, MZ-260, CA-60, SS-3, SS-3LA). It is preferable to appropriately select particles that do not expand at the curing temperature of the epoxy resin composition but expand at the heating temperature during dismantling.

[0221] As for the proportion of the thermally expandable particles (D) used, from the viewpoint of exhibiting the effect of sufficiently expanding and reducing adhesion during dismantling after use without impairing the adhesion or flexibility of the cured product when curing the epoxy resin composition of this embodiment, it is preferable to use them in the range of 3 to 40 parts by mass, 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, per 100 parts by mass of the total of epoxy resin (A) and epoxy resin (B).

[0222] [Compound (I)] The epoxy resin composition of this embodiment preferably further contains a compound (I) that is reactive with the glycidyl ether group-containing compound (C). The glycidyl ether group-containing compound (C) according to this embodiment can be used in combination with compound (I) to form a curable epoxy resin composition. The epoxy resin composition can be suitably used in various electrical and electronic component applications such as adhesives, paints, photoresists, printed circuit boards, and semiconductor encapsulation materials.

[0223] Examples of compounds (I) that react with the glycidyl ether group-containing compound (C) include various known curing agents for epoxy resins, such as amine compounds, acid anhydrides, amide compounds, phenolic hydroxyl group-containing compounds, carboxylic acid compounds, and thiol compounds. The curing agent can be appropriately selected depending on the physical properties of the desired cured product, but it is particularly preferable to use a hydroxyl group-containing compound or an amine group-containing compound from the viewpoint of mechanical strength and adhesion to the substrate.

[0224] 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, triethylenetetramine, and 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, and other aliphatic amine compounds;

[0225] 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);

[0226] Aromatic amine compounds such as o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, pyridine, and picoline;

[0227] Examples include epoxy compound-added polyamines, Michael-added polyamines, Mannich-added polyamines, thiourea-added polyamines, ketone-blocked polyamines, dicyandiamides, guanidines, organic acid hydrazides, diaminomaleonitriles, amineimides, boron trifluoride-piperidine complexes, boron trifluoride-monoethylamine complexes, and other modified amine compounds.

[0228] 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.

[0229] The phenolic hydroxyl group-containing compounds include bisphenols such as bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, and 1,1-bis(4-hydroxyphenyl)-1-phenylethane, and bis(4-hydroxyphenyl)sulfone, phenol novolac resins, cresol novolac resins, aromatic hydrocarbon formaldehyde resin-modified phenol resins, dicyclopentadienephenol addition type resins, phenol aralkyl resins (Zyloc resins), naphthol aralkyl resins, and trimethylol methane resins. Examples of polyhydric phenol compounds include tetraphenyloleethane resin, naphthol novolac resin, naphthol-phenol co-condensed novolac resin, naphthol-cresol co-condensed novolac resin, biphenyl-modified phenol resin (a polyhydric phenol compound in which the phenol nucleus is linked by a bismethylene group), biphenyl-modified naphthol resin (a polyhydric naphthol compound in which the phenol nucleus is linked by a bismethylene group), aminotriazine-modified phenol resin (a polyhydric phenol compound in which the phenol nucleus is linked by melamine, benzoguanamine, etc.), and alkoxy-group-containing aromatic ring-modified novolac resin (a polyhydric phenol compound in which the phenol nucleus and alkoxy-group-containing aromatic ring are linked by formaldehyde).

[0230] Examples of the amide compounds include dicyandiamide and polyamidoamine. Examples of polyamidoamines include those obtained by reacting aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid, or carboxylic acid compounds such as fatty acids and dimer acids, with aliphatic polyamines or polyamines having polyoxyalkylene chains.

[0231] Examples of the carboxylic acid compound include carboxylic acid-terminated polyesters, polyacrylic acid, maleic acid-modified polypropylene glycols, and other carboxylic acid polymers.

[0232] 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.

[0233] When using these curing agents, one type of curing agent may be used, or two or more types may be mixed. For applications such as underfill materials and general paints, it is preferable to use the aforementioned amine compounds, carboxylic acid compounds, and / or acid anhydride compounds. Furthermore, for adhesives and flexible wiring board applications, amine compounds, particularly dicyandiamide, are preferred in terms of workability, curability, and long-term stability. For semiconductor encapsulation materials, solid-type phenolic compounds are preferred in terms of the heat resistance of the cured product. In battery applications, aliphatic amines and thiol compounds are preferred in terms of low-temperature curing.

[0234] Furthermore, from the viewpoint of further enhancing the effects of the present invention, it is preferable that the compound (I) that reacts with the glycidyl ether group-containing compound (C) is a hydroxyl group-containing compound or an amino group-containing compound having a reversible bond.

[0235] Examples of hydroxyl group-containing compounds or amino group-containing compounds having the reversible bond include those in which a structural unit A' having one or more hydroxyl groups or amino groups and a structural unit B' different from A' are linked in the A'-B'-A' manner, and the structural unit A' and the structural unit B' are linked by a reversible bond.

[0236] Examples of the reversible bond mentioned above include those similar to the reversible bond in the glycidyl ether group-containing compound (C) in this embodiment.

[0237] [Other epoxy resins] Furthermore, the epoxy resin composition of this embodiment can be used in combination with other epoxy resins other than the epoxy resin (A), epoxy resin (B), and glycidyl ether group-containing compound (C) of this embodiment, to the extent that the effects of this embodiment are not impaired. In this case, the total amount of epoxy resin (A), epoxy resin (B), and glycidyl ether group-containing compound (C) in the epoxy resin composition of this embodiment is preferably 30% by mass or more of the total epoxy resin, and particularly preferably 40% by mass or more.

[0238] Other epoxy resins that can be used in combination are not limited in any way other than not belonging to epoxy resin (A), epoxy resin (B), or glycidyl ether group-containing compound (C), 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, phenol novolac type epoxy resin, cresol novolac type epoxy resin, Examples include triphenylmethane type epoxy resins, 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, aromatic hydrocarbon formaldehyde resin-modified phenol resin 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.

[0239] In this embodiment, the concentration of reversible bonds in the epoxy resin composition 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 decomposition properties of the cured product obtained from the epoxy resin composition are all further improved. The concentration of the aforementioned reversible bonds is more preferably 0.10 to 3.00 mmol / g, and even more preferably 0.15 to 2.00 mmol / g. Furthermore, in the case where the glycidyl ether group-containing compound (C) of this embodiment has multiple reversible bonds, or when the aforementioned hydroxyl group-containing compound having reversible bonds is used alone or in combination with other curing agents as a curing agent, 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 functions are more likely to be exhibited even at the lower end of the preferred range of concentrations. 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 range of concentrations. However, in the temperature range above the glass transition temperature measured by DMA, molecular mobility is generally high, and sufficient adhesion, flexibility, and decomposition functions are more likely to be exhibited even at low concentrations of the glycidyl ether group-containing compound (C). Therefore, the effect of exhibiting adhesion, flexibility, and decomposition functions can also be adjusted by appropriately adjusting the aging temperature for curing or the heating temperature for decomposition. Thus, the relationship between the glass transition temperature of the cured product and the concentration of the reversible bond is not limited to these.

[0240] In the epoxy resin composition of this embodiment, there are no particular limitations on the ratio of the total amount of glycidyl ether groups to the total amount of active groups that can react with these glycidyl ether groups. However, from the standpoint of obtaining good mechanical properties for the resulting cured product, it is preferable that the amount of active groups that can react with glycidyl ether groups is 0.4 to 1.5 equivalents for every 1 equivalent of the total amount of glycidyl ether groups in the resin composition.

[0241] [Curing accelerator] The epoxy resin composition of this embodiment may contain a curing accelerator. Various curing accelerators can be used, but examples include urea compounds, phosphorus compounds, tertiary amines, imidazoles, imidazolines, organic acid metal salts, Lewis acids, and aminates. 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 is preferred among tertiary amines due to their excellent curability, heat resistance, electrical properties, and moisture resistance reliability.

[0242] 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.

[0243] Examples of the imidazoles include imidazole, 1-methylimidazole, 2-methylimidazole, 3-methylimidazole, 4-methylimidazole, 5-methylimidazole, 1-ethylimidazole, 2-ethylimidazole, 3-ethylimidazole, 4-ethylimidazole, 5-ethylimidazole, 1-n-propylimidazole, 2-n-propylimidazole, 1-isopropylimidazole, 2- Sopropylimidazole, 1-n-butylimidazole, 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, 1-phenylimidazole, 2-phenyl-1H-imidazole Dazole, 4-methyl-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 Examples include socianuric acid adducts, 2-methylimidazole isocyanuric acid adducts, 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.

[0244] Examples of the imidazoline compounds include 2-methylimidazoline and 2-phenylimidazoline.

[0245] 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.

[0246] [Other thermosetting resins and thermoplastic resins] Furthermore, the epoxy resin composition of this embodiment may also be used in combination with other thermosetting resins or thermoplastic resins, to the extent that it does not impair the effects of this embodiment.

[0247] Other thermosetting resins include, for example, cyanate ester resins, resins having a benzoxazine structure, activated ester resins, vinyl benzyl compounds, acrylic compounds, and copolymers of styrene and maleic anhydride. 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.

[0248] 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, cresol novolac type cyanate ester resin, and triphenyl Examples include rumethane-type cyanate ester resins, tetraphenylethane-type cyanate ester resins, dicyclopentadiene-phenol addition reaction type cyanate ester resins, phenol aralkyl-type cyanate ester resins, naphthol novolac-type cyanate ester resins, naphthol aralkyl-type cyanate ester resins, naphthol-phenol co-condensed novolac-type cyanate ester resins, naphthol-cresol co-condensed novolac-type cyanate ester resins, aromatic hydrocarbon formaldehyde resin-modified phenol resin-type cyanate ester resins, biphenyl-modified novolac-type cyanate ester resins, anthracene-type cyanate ester resins, and the like. These may be used individually or in combination of two or more types.

[0249] Among these cyanate ester resins, 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 for obtaining cured products with excellent heat resistance, while dicyclopentadiene-phenol addition reaction type cyanate ester resin is preferred for obtaining cured products with excellent dielectric properties.

[0250] There are no particular restrictions on the resin having a benzoxazine structure, but examples include the reaction product of bisphenol F, formalin, and aniline (Fa-type benzoxazine resin), the reaction product of diaminodiphenylmethane, formalin, and phenol (Pd-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.

[0251] 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 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.

[0252] As the active ester resin, specifically, active ester resins containing a dicyclopentadiene-phenol addition structure, active ester resins containing a naphthalene structure, active ester resins that are acetylated phenol novolacs, and active ester resins that are benzoylated phenol novolacs are preferred, and 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.

[0253] Furthermore, various novolac resins, addition polymerization resins of alicyclic diene compounds such as dicyclopentadiene and phenol compounds, modified novolac resins of phenolic hydroxyl group-containing compounds and alkoxy group-containing aromatic compounds, phenol aralkyl resins (Zyloc resins), naphthol aralkyl resins, trimethylol methane resins, tetraphenyloleethane resins, biphenyl-modified phenol resins, biphenyl-modified naphthol resins, aminotriazine-modified phenol resins, and various vinyl polymers may be used in combination.

[0254] The aforementioned novolac resins include, more specifically, polymers obtained by reacting phenolic hydroxyl group-containing compounds such as phenol, phenylphenol, resorcinol, biphenyl, bisphenol A and bisphenol F, naphthol, and dihydroxynaphthalene with aldehyde compounds under acid-catalyzed conditions.

[0255] 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.

[0256] Thermoplastic resins are 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 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 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.

[0257] When using these other resins, the mixing ratio of the glycidyl ether group-containing compound (C) of this embodiment to the other resin can be arbitrarily set according to the application. However, from the standpoint of excellent adhesion, flexibility, and decomposability when cured, it is preferable that the ratio is 0.5 to 100 parts by mass of the other resin to 100 parts by mass of the glycidyl ether group-containing compound (C) of this embodiment.

[0258] [Non-halogenated flame retardant] When the epoxy resin composition of this embodiment is used in applications requiring high flame retardancy, a non-halogen-based flame retardant that substantially does not contain halogen atoms may be incorporated.

[0259] Examples of the non-halogenated flame retardants include phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, inorganic flame retardants, organometallic salt-based flame retardants, etc. There are no restrictions on their use; they can be used individually, multiple flame retardants of the same type can be used together, or flame retardants of different types can be used in combination.

[0260] The phosphorus-based flame retardant can be either inorganic or organic. Examples of inorganic compounds 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.

[0261] 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 coating of an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, titanium hydroxide.

[0262] 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.

[0263] The amount of these phosphorus-based flame retardants to be blended 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 a resin composition containing all non-halogen-based flame retardants and other fillers and additives, when red phosphorus is used as the 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 organophosphorus compounds, it is preferable to blend them 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.

[0264] Furthermore, when using the 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.

[0265] Examples of the nitrogen-based flame retardant include triazine compounds, cyanuric acid compounds, isocyanuric acid compounds, and phenothiazines, with triazine compounds, cyanuric acid compounds, and isocyanuric acid compounds being preferred.

[0266] The aforementioned triazine compounds include, for example, melamine, acetoganamine, benzoguanamine, melon, melam, succinoguanamine, ethylenedimelamine, polyphosphate melamine, triguanamine, etc., as well as, for example, (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.

[0267] Examples of the cyanuric acid compound include cyanuric acid and melamine cyanurate.

[0268] The amount of nitrogen-based flame retardant to be blended is appropriately selected depending on the type of nitrogen-based 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 10 parts by mass, and more preferably in the range of 0.1 to 5 parts by mass, per 100 parts by mass of the resin composition containing the non-halogen-based flame retardant and other fillers and additives.

[0269] Furthermore, when using the nitrogen-based flame retardant, metal hydroxides, molybdenum compounds, etc., may be used in combination.

[0270] The silicone-based flame retardant can be any organic compound containing silicon atoms, and examples include silicone oil, silicone rubber, and silicone resin. The amount of the silicone-based flame retardant is appropriately selected depending on the type of silicone-based 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 0.05 to 20 parts by mass per 100 parts by mass of the resin composition containing the non-halogen-based flame retardant and other fillers and additives. Furthermore, when using the silicone-based flame retardant, molybdenum compounds, alumina, etc., may be used in combination.

[0271] Examples of the inorganic flame retardants include metal hydroxides, metal oxides, metal carbonate compounds, metal powders, boron compounds, and low-melting-point glass.

[0272] Examples of the aforementioned metal hydroxides include aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, and zirconium hydroxide.

[0273] Examples of the aforementioned metal oxides include zinc molybdate, molybdenum trioxide, zinc stannate, tin oxide, aluminum oxide, iron oxide, titanium oxide, manganese oxide, zirconium oxide, zinc oxide, molybdenum oxide, cobalt oxide, bismuth oxide, chromium oxide, nickel oxide, copper oxide, and tungsten oxide.

[0274] Examples of the aforementioned metal carbonate compounds include zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate, basic magnesium carbonate, aluminum carbonate, iron carbonate, cobalt carbonate, and titanium carbonate.

[0275] Examples of the aforementioned metal powders include aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, nickel, copper, tungsten, and tin.

[0276] Examples of the boron compounds mentioned above include zinc borate, zinc metaborate, barium metaborate, boric acid, and borax.

[0277] Examples of the low-melting-point glass include glassy compounds such as Sheeplee (Voxui-Brown), hydrated glass SiO2-MgO-H2O, PbO-B2O3 system, ZnO-P2O5-MgO system, P2O5-B2O3-PbO-MgO system, P-Sn-OF system, PbO-V2O5-TeO2 system, Al2O3-H2O system, and lead borosilicate system.

[0278] 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, per 100 parts by mass of the resin composition containing the non-halogenated flame retardant and all other fillers and additives.

[0279] 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 is ionically bonded or coordinately bonded to an aromatic compound or heterocyclic compound.

[0280] 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 parts by mass to 10 parts by mass per 100 parts by mass of the resin composition containing all other fillers and additives, including the non-halogenated flame retardant.

[0281] [Filler] The epoxy resin composition of this embodiment may contain fillers that do not belong to the thermally expandable particles (D) according to this embodiment. Examples of fillers include inorganic fillers and organic fillers. Examples of inorganic fillers include inorganic fine particles.

[0282] Examples of inorganic fine particles include, for example, those with excellent heat resistance: alumina, magnesia, titania, zirconia, silica (quartz, fumed silica, precipitated silica, anhydrous silicic acid, fused silica, crystalline silica, ultrafine amorphous silica, etc.); those with excellent thermal conductivity: boron nitride, aluminum nitride, aluminum oxide, titanium oxide, magnesium oxide, zinc oxide, silicon oxide, diamond, etc.; those with excellent electrical conductivity: metal fillers and / or metal-coated fillers using elemental metals or alloys (e.g., iron, copper, magnesium, aluminum, gold, silver, platinum, zinc, manganese, stainless steel, etc.); those with excellent barrier properties: minerals such as mica, clay, kaolin, talc, zeolite, wollastonite, smectite, potassium titanate, magnesium sulfate, sepiolite, zonolite. Examples of photocatalytic materials include aluminum borate, calcium carbonate, titanium dioxide, barium sulfate, zinc oxide, and magnesium hydroxide; materials with high refractive index include barium titanate, zirconia oxide, and titanium dioxide; materials exhibiting photocatalytic properties include photocatalytic metals such as titanium, cerium, zinc, copper, aluminum, tin, indium, phosphorus, carbon, sulfur, ruthenium, nickel, iron, cobalt, silver, molybdenum, strontium, chromium, barium, and lead, as well as composites of the aforementioned metals and their oxides; materials with excellent wear resistance include metals such as silica, alumina, zirconia, and magnesium oxide, and their composites and oxides; materials with excellent conductivity include metals such as silver and copper, tin oxide, and indium oxide; materials with excellent insulation properties include silica; and materials 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 above inorganic fine particles have various properties other than those listed as examples, they should be selected as appropriate for the application.

[0283] For example, when using silica as inorganic fine particles, 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 Aerosil 50 and 200 from Nippon Aerosil Co., Ltd., Sildex H31, H32, H51, H52, H121, and H122 from Asahi Glass Co., Ltd., E220A and E220 from Nippon Silica Industry Co., Ltd., SYLYSIA 470 from Fuji Silysia Co., Ltd., and SG Flake from Nippon Sheet Glass Co., Ltd.

[0284] Examples of commercially available colloidal silica include methyl silica sol, 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, and ST-OL, all manufactured by Nissan Chemical Industries, Ltd.

[0285] Surface-modified silica nanoparticles may also be used. For example, silica nanoparticles may be surface-treated with a reactive silane coupling agent having a hydrophobic group, or modified with a compound having a (meth)acryloyl group. Examples of commercially available powdered silica modified with a compound having a (meth)acryloyl group include Aerosil RM50 and R711 from Nippon Aerosil Co., Ltd., and examples of commercially available colloidal silica modified with a compound having a (meth)acryloyl group include MIBK-SD from Nissan Chemical Industries, Ltd.

[0286] 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.

[0287] As titanium dioxide nanoparticles, not only extender pigments but also UV-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, it can be used as a powder, a sol dispersed in an organic solvent or water, or a slurry. Examples of commercially available powdered titanium dioxide nanoparticles include Aerosil P-25 manufactured by Nippon Aerosil Co., Ltd. and ATM-100 manufactured by Teika Co., Ltd. Examples of commercially available slurry-type titanium dioxide nanoparticles include TKD-701 manufactured by Teika Co., Ltd.

[0288] [fibrous matrix] The epoxy resin composition of this embodiment may further contain a fibrous substrate. The fibrous substrate is not particularly limited, but those used in fiber-reinforced resins are preferred, and examples include inorganic fibers and organic fibers.

[0289] Inorganic fibers include carbon fibers, glass fibers, boron fibers, alumina fibers, silicon carbide fibers, as well as carbon fibers, activated carbon fibers, graphite fibers, tungsten carbide fibers, silicon carbide fibers (silicon carbide fibers), ceramic fibers, natural fibers, mineral fibers such as basalt, boron nitride fibers, boron carbide fibers, and metal fibers. Examples of the above-mentioned metal fibers include aluminum fibers, copper fibers, brass fibers, stainless steel fibers, and steel fibers.

[0290] Examples of organic fibers include synthetic fibers made from resin materials such as polybenzazole, aramid, PBO (poly-p-phenylenebenzoxazole), polyphenylene sulfide, polyester, acrylic, polyamide, polyolefin, polyvinyl alcohol, and polyarylate; natural fibers such as cellulose, pulp, cotton, wool, and silk; and regenerated fibers such as proteins, polypeptides, and alginic acid.

[0291] Among these, carbon fiber and glass fiber are preferred because they have a wide range of industrial applications. Only one of these materials may be used, or multiple materials may be used simultaneously.

[0292] The fibrous matrix may be an aggregate of fibers, and the fibers may be continuous or discontinuous, and may be woven or unwoven. It may also be a bundle of fibers aligned in one direction, or a sheet made of arranged fiber bundles. Furthermore, it may be a three-dimensional shape with thickness given to the aggregate of fibers.

[0293] [Dispersion medium] The epoxy resin composition of 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.

[0294] Examples of the aforementioned organic solvents include ketones such as acetone, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK); cyclic ethers such as tetrahydrofuran (THF) and dioxolane; esters such as methyl acetate, ethyl acetate, and butyl acetate; aromatics such as toluene and xylene; and alcohols such as carbitol, cellosolve, methanol, isopropanol, butanol, and propylene glycol monomethyl ether. These can be used alone or in combination. Among these, methyl ethyl ketone is preferred in terms of volatility during coating and solvent recovery.

[0295] 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), amine salts of specially modified phosphate esters (HIPLAAD ED-251: Kusumoto Kasei), and modified acrylic block copolymers (DISPERBYK2000: Bic Chemie).

[0296] [Other ingredients] 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, coupling agents, dyes, leveling agents, rheology control agents, UV absorbers, antioxidants, flame retardants, plasticizers, reactive diluents, and the like.

[0297] 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.

[0298] Furthermore, the epoxy resin composition of this embodiment can also be cured using active energy rays. In this case, a photocationic polymerization initiator can be used as the polymerization initiator. As the active energy ray, visible light, ultraviolet rays, X-rays, electron beams, etc., can be used.

[0299] Examples of photocationic polymerization initiators include aryl sulfonium salts and aryl iodonium salts. Specifically, aryl sulfonium hexafluorophosphate, aryl sulfonium hexafluoroantimonate, aryl sulfonium tetrakis(pentafluoro)borate, and tri(alkylphenyl)sulfonium hexafluorophosphate can be used. Photocationic polymerization initiators may be used alone or in combination of two or more.

[0300] [Method for preparing epoxy resin compositions] The epoxy resin composition of this embodiment can be prepared by uniformly mixing the aforementioned components, and the method of preparation 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, etc.

[0301] The epoxy resin composition of this embodiment is prepared by dissolving the epoxy resin (A) of this embodiment, the epoxy resin (B) of this embodiment, the glycidyl ether group-containing compound (C) of this embodiment, the heat-expandable particles (D) of this embodiment, and optionally a compound (I) that is reactive with the glycidyl ether group-containing compound (C), and optionally the aforementioned compatible curing agent, filler, fibrous substrate, dispersion medium, and resins other than the aforementioned various compounds, in a dispersion medium such as the aforementioned organic solvent. After dissolution, the solvent is removed by distillation, and the epoxy resin composition can be obtained by drying under reduced pressure in a vacuum oven or the like. Alternatively, the epoxy resin composition of this embodiment may be a state in which the aforementioned constituent materials are uniformly mixed. In this case, it is preferable to mix them uniformly in a mixer or the like. The mixing ratio of each constituent material can be appropriately adjusted according to the desired properties such as the mechanical strength and heat resistance of the cured product. Furthermore, there are no particular limitations on the specific mixing order of the constituent materials in the preparation of the epoxy resin composition.

[0302] (cured product) The cured product of this embodiment is obtained by curing a compound (I) that is reactive with the glycidyl ether group-containing compound (C) of this embodiment. The curing method can be appropriately selected and adopted from known methods depending on the properties of the compound (I) that is reactive with the glycidyl ether group-containing compound (C) used.

[0303] As described above, the cured product of this embodiment is cured with the glycidyl ether group-containing compound (C) of this embodiment, and by exhibiting an appropriate crosslinking density, it is possible to maintain good mechanical strength.

[0304] The structure of the resulting cured product can be confirmed by infrared absorption (IR) spectroscopy using Fourier transform infrared spectroscopy (FT-IR), elemental analysis, X-ray scattering, etc.

[0305] As described above, a cured product according to one embodiment of this invention can be obtained by using the glycidyl ether group-containing compound (C) of this embodiment as a component of an epoxy resin composition. However, it is also possible to use the aforementioned conjugated diene intermediate, which is an intermediate of the glycidyl ether group-containing compound (C), and to use a compound that can undergo addition reactions by a Diels-Alder reaction in combination with it, thereby forming the glycidyl ether group-containing compound (C) during the curing process (synthesizing it in situ) to obtain a cured product.

[0306] For example, when a curing reaction is carried out using the compound represented by formula (4)', a furan having a glycidyl ether group, and a compound (I) that is reactive with the glycidyl ether group-containing compound (C) as essential raw materials, the glycidyl ether group-containing compound (C) represented by formula (4) can be obtained during the curing reaction, and a cured product can be obtained as the curing reaction progresses. The maleimide having a glycidyl ether group that can be used at this time is the same as described above.

[0307] The epoxy resin composition of this embodiment and the cured product produced using this epoxy resin composition have adhesive properties, flexibility, and decomposability, and are useful for the following applications.

[0308] The curable resin cured product of this embodiment can be laminated with a substrate to form a laminate. The substrate of the laminate may be an inorganic material such as metal or glass, or an organic material such as plastic or wood, depending on the application. The laminate may be in the shape of a flat plate, a sheet, or a three-dimensional structure, or it may be three-dimensional. It may also be any shape that suits the purpose, such as having curvature on the entire surface or in part. There are also no restrictions on the hardness, thickness, etc., of the substrate. Alternatively, a multilayer laminate may be formed by laminating a first substrate, a layer made of the cured epoxy resin composition of this embodiment, and a second substrate in that order. Because the epoxy resin composition of this embodiment has excellent adhesive properties, it can be suitably used as an adhesive to bond the first substrate and the second substrate. Alternatively, the curable resin cured product of this embodiment may be used as a substrate, and the cured product of this embodiment may be laminated further.

[0309] Furthermore, since the curable resin product of this embodiment can relieve stress, it is particularly suitable for bonding dissimilar materials. For example, even if the substrate is a metal and / or metal oxide and the second substrate is a laminate of dissimilar materials such as a plastic layer, the adhesive strength is maintained due to the stress-relieving ability of the cured product of this embodiment.

[0310] In a laminate formed by laminating a cured product of this embodiment with a substrate, the layer containing the cured product may be formed by direct coating or molding onto the substrate, 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 spray coating, spin coating, dip coating, roll coating, blade coating, doctor roll coating, doctor blade coating, curtain coating, slit coating, screen printing, and inkjet coating. 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 product of the composition may be laminated onto the substrate. Furthermore, the cured product of this embodiment may be laminated by coating a precursor that can serve as a substrate with it and curing it, or the precursor that can serve as a substrate or the composition of this embodiment may be bonded in an uncured or semi-cured state and then cured. There are no particular limitations on the precursor that can serve as a substrate, and examples include various epoxy resin compositions.

[0311] The cured product obtained using the epoxy resin composition of this embodiment exhibits particularly high adhesion to metals and / or metal oxides, making it particularly suitable for use as a primer for metals. Examples of metals include copper, aluminum, gold, silver, iron, platinum, chromium, nickel, tin, titanium, zinc, various alloys, and composite materials thereof. Examples of metal oxides include individual oxides and / or composite oxides of these metals. Because it exhibits particularly excellent adhesion to iron, copper, and aluminum, it is well suitable for use as an adhesive for iron, copper, and aluminum.

[0312] The epoxy resin composition of this embodiment can be suitably used as an adhesive for structural members in the fields of automobiles, trains, civil engineering and construction, electronics, aircraft, and the aerospace industry. Even when used to bond dissimilar materials, such as metal-nonmetallic materials, this adhesive maintains high adhesion regardless of temperature changes, making peeling less likely. Furthermore, in addition to structural member applications, this adhesive can be used as an adhesive for general office use, medical applications, carbon fiber, battery cells, modules, and cases, and can also be used as an adhesive for bonding optical components, bonding optical discs, mounting printed circuit boards, die bonding, underfills, BGA reinforcement underfills, anisotropic conductive films, anisotropic conductive pastes, and other mounting applications.

[0313] If the epoxy resin composition of this embodiment has a fibrous substrate and the fibrous substrate is a reinforcing fiber, the epoxy resin composition containing the fibrous substrate can be used as a fiber-reinforced resin. The method for incorporating the fibrous substrate into the composition is not particularly limited as long as it does not impair the effects of this embodiment, and examples include compounding the fibrous substrate and the composition by methods such as kneading, coating, impregnation, injection, and compression, which can be appropriately selected depending on the form of the fibers and the application of the fiber-reinforced resin.

[0314] There are no particular limitations on the method of molding fiber-reinforced resins. For plate-shaped products, extrusion molding is common. It is also possible to use a flat press. In addition, extrusion molding, blow molding, compression molding, vacuum molding, injection molding, etc., can be used. When manufacturing film-shaped products, in addition to melt extrusion, solution casting can be used. When using melt molding methods, examples include inflation film molding, cast molding, extrusion lamination molding, calendering, sheet molding, fiber molding, blow molding, injection molding, rotational molding, and coating molding. Furthermore, in the case of resins that harden with active energy rays, cured products can be manufactured using various hardening methods that utilize active energy rays. In particular, when thermosetting resins are the main component of the matrix resin, molding methods that involve pre-pregging the molding material and heating it under pressure using a press or autoclave can be used. Other examples include RTM (Resin Transfer Molding) molding, VaRTM (Vacuum Assist Resin Transfer Molding) molding, lamination molding, and hand lay-up molding.

[0315] The epoxy resin composition of this embodiment can be used for large cases, motor housings, casting materials for the inside of cases, gears, pulleys, and other molding materials, as the cured products using it exhibit excellent adhesion, flexibility, and decomposability. These may be cured products of the resin alone, or cured products reinforced with fibers such as glass chips.

[0316] Fiber-reinforced resins can form an uncured or semi-cured state called a prepreg. After distributing the product in the prepreg state, final curing may be performed to form a cured product. When forming a laminate, it is preferable to form the prepreg first, then laminate the other layers, and then perform final curing, as this allows for the formation of a laminate in which each layer is tightly bonded. The mass ratio of the composition and fibrous substrate used at this time is not particularly limited, but it is generally preferable to prepare the prepreg so that the resin content is 20 to 60% by mass.

[0317] The cured product of this embodiment has excellent adhesion, flexibility, and decomposability, making it suitable for use as a heat-resistant material and an electronic material. In particular, it is suitable for use as a semiconductor encapsulant, circuit board, build-up film, build-up substrate, adhesive, and resist material. It is also suitable for use as a matrix resin for fiber-reinforced resins and is especially suitable as a high-heat-resistant prepreg. The heat-resistant and electronic components thus obtained can be suitably used in a variety of applications, including, but are not limited to, industrial machine parts, general machine parts, automobile, railway, and vehicle parts, aerospace-related parts, electronic and electrical components, building materials, containers and packaging materials, household goods, sports and leisure goods, and wind turbine enclosure components.

[0318] In particular, taking advantage of its excellent flexibility in cured products, it can be suitably used as an adhesive for structural components in the fields of automobiles, trains, civil engineering and construction, electronics, aircraft, and the aerospace industry. The adhesive of this embodiment can maintain high adhesion regardless of changes in temperature, even when used to bond dissimilar materials such as metal-nonmetal, and is less prone to peeling. In addition to structural component applications, the adhesive of this embodiment can also be used as an adhesive for general office use, medical use, carbon fiber, battery cells, modules and cases, etc. Examples include adhesives for bonding optical components, adhesives for bonding optical discs, adhesives for mounting printed circuit boards, die bonding adhesives, semiconductor adhesives such as underfills, underfills for BGA reinforcement, anisotropic conductive films, anisotropic conductive pastes, and other mounting adhesives.

[0319] Furthermore, taking advantage of the excellent ease of disassembly characteristic of the cured product of this embodiment, an easily disassemblable adhesive material containing the epoxy resin composition of this embodiment can be used. Preferably, the easily disassemblable adhesive material is the epoxy resin composition of this embodiment. A disassembly method using the easily disassemblable adhesive material of this embodiment includes, for example, a bonding step of attaching the easily disassemblable adhesive material to the surface of an object and joining it to the object; a curing step of curing the easily disassemblable adhesive material to obtain a cured product; a heat treatment step of performing a heat treatment on the cured product to thermally dissociate the reversible bonds contained in the general formula (4) derived from the glycidyl ether group-containing compound (C) and to expand the thermally expandable particles (D); and a disassembly step of disassembling the object and the cured product. Furthermore, the dismantling method using the easily dismantled adhesive material of this embodiment may include, for example, a bonding step of attaching the easily dismantled adhesive material to the surface of an object and joining it to the object; a curing step of curing the easily dismantled adhesive material to obtain a cured product; a heat treatment step of performing a heat treatment on the cured product to thermally dissociate the reversible bonds contained in the general formula (4) derived from the glycidyl ether group-containing compound (C) and to expand the thermally expandable particles (D); a cooling step of cooling the cured product after heat treatment to room temperature; and a dismantling step of dismantling the object and the cured product.

[0320] The following will provide examples of representative products.

[0321] 1. Semiconductor encapsulation materials A method for obtaining a semiconductor encapsulating material from the resin composition of this embodiment is to thoroughly melt and mix the resin composition, a curing accelerator, and compounding agents such as inorganic fillers using an extruder, needle, roll, etc., as needed, until uniform. In this case, fused silica is usually used as the inorganic filler, but when used as a high thermal conductivity semiconductor encapsulating material for power transistors and power ICs, it is preferable to use a higher filler of crystalline silica, alumina, silicon nitride, etc., which have higher thermal conductivity than fused silica, or to use fused silica, crystalline silica, alumina, silicon nitride, etc. The filler ratio is preferably in the range of 30 to 95% by mass of inorganic filler per 100 parts by mass of epoxy resin composition, and in order to improve flame retardancy, moisture resistance, solder crack resistance, and the coefficient of linear expansion, it is more preferable to use 70 parts by mass or more, and even more preferable to use 80 parts by mass or more.

[0322] 2. Semiconductor equipment A semiconductor package molding method for obtaining a semiconductor device from the epoxy resin composition of this embodiment involves molding the semiconductor encapsulation material by casting, or using a transfer molding machine, injection molding machine, etc., and then heating it at 50 to 250°C for 2 to 10 hours.

[0323] 3. Printed circuit board A method for obtaining a printed circuit board from the composition of this embodiment is to laminate the prepreg by a conventional method, add copper foil as appropriate, and heat-press it at 170 to 300°C for 10 minutes to 3 hours under pressure of 1 to 10 MPa.

[0324] 4. Flexible substrate A method for manufacturing a flexible substrate from the crosslinkable resin composition of this embodiment includes the following three-step process. The first step is to apply the crosslinkable resin composition, which contains resin components and organic solvents, to an electrical insulating film using a coating machine such as a reverse roll coater or comma coater. The second step is to heat the electrical insulating film coated with the crosslinkable resin composition using a heater at 60 to 170°C for 1 to 15 minutes to evaporate the solvent from the electrical insulating film and B-stage the crosslinkable resin composition. The third step is to heat-press a metal foil onto the B-staged electrical insulating film using a heating roll or the like to attach it to an adhesive (preferably with a pressing pressure of 2 to 200 N / cm and a pressing temperature of 40 to 200°C). If sufficient adhesive performance is obtained through the three steps described above, the process can be terminated here. However, if complete adhesive performance is required, it is preferable to further cure the resin at 100-200°C for 1-24 hours. The thickness of the resin composition layer after final curing is preferably in the range of 5-100 μm.

[0325] 5. Build-up board A method for obtaining a build-up substrate from the composition of this embodiment includes the following steps, for example. First, the above composition, which contains rubber, fillers, etc., is applied to a circuit board with a circuit formed on it using a spray coating method, a curtain coating method, etc., and then cured (Step 1). After that, holes such as predetermined through-holes are drilled as needed, then the surface is treated with a roughening agent, and the surface is washed with hot water to form irregularities, and then plated with a metal such as copper (Step 2). These operations are repeated sequentially as desired to alternately build up and form a resin insulating layer and a conductor layer of a predetermined circuit pattern (Step 3). Note that the drilling of through-holes is performed after the formation of the outermost resin insulating layer. Furthermore, the build-up substrate of this embodiment can also be manufactured by forming a roughened surface and omitting the plating process by heating and pressing a resin-coated copper foil, which has the resin composition partially cured on a copper foil, onto a wiring board with a circuit formed on it at 170 to 300°C.

[0326] 6. Build-up film A build-up film can be obtained from the composition of this embodiment by applying the composition to the surface of a support film (Y) which is a base material, and then drying the organic solvent by heating or blowing hot air to form a layer (X) of the composition.

[0327] The organic solvents used here preferably include ketones such as acetone, methyl ethyl ketone, and cyclohexanone; acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; and it is preferable to use them in a proportion that results in a non-volatile content of 30 to 60% by mass.

[0328] The thickness of the formed layer (X) is usually equal to or greater than the thickness of the conductor layer. Since the thickness of the conductor layer of a circuit board is usually in the range of 5 to 70 μm, it is preferable that the thickness of the resin composition layer be 10 to 100 μm. In this embodiment, the above composition layer (X) may be protected by a protective film, which will be described later. By protecting it with a protective film, it is possible to prevent dust and other debris from adhering to the surface of the resin composition layer and to prevent scratches.

[0329] The aforementioned support film and protective film can be made of polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate, polycarbonate, polyimide, and also release paper and metal foils such as copper foil and aluminum foil. The support film and protective film may be treated with matte finish, corona finish, or release finish. The thickness of the support film is not particularly limited, but is usually 10 to 150 μm, and preferably in the range of 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0330] The support film (Y) described above is peeled off after lamination to the circuit board or after an insulating layer is formed by heat curing. If the support film (Y) is peeled off after the epoxy resin composition layer constituting the build-up film has heat cured, it is possible to prevent the adhesion of dust and other contaminants during the curing process. When peeling off after curing, the support film is usually treated with a release agent beforehand.

[0331] A multilayer printed circuit board can be manufactured using the build-up film obtained as described above. For example, if layer (X) is protected by a protective film, these are removed, and then layer (X) is laminated to one or both sides of the circuit board so that it is in direct contact with the circuit board, for example, by vacuum lamination. The lamination method may be batch or continuous on a roll. If necessary, the build-up film and the circuit board may be heated (preheated) before lamination. The lamination conditions are preferably a pressure temperature (lamination temperature) of 70 to 140°C and a pressure of 1 to 11 kgf / cm². 2 (9.8 × 10 4 ~107.9×10 4 N / m 2 It is preferable to use this method, and it is preferable to laminate under reduced pressure of 20 mmHg (26.7 hPa) or less.

[0332] 7. Conductive paste One method for obtaining a conductive paste from the epoxy resin composition of this embodiment is to disperse conductive particles in the composition. Depending on the type of conductive particles used, the conductive paste can be a paste resin composition for circuit connection or an anisotropic conductive adhesive. [Examples]

[0333] Next, this embodiment will be described in detail with reference to examples and comparative examples, but in the following, "parts" and "%" refer to mass unless otherwise specified. This embodiment is not limited thereto.

[0334] 1 H-NMR and 13 ¹¹¹NMR, FD-MS spectra, and GPC were measured under the following conditions.

[0335] 1 H-NMR: “JNM-ECA600” manufactured by JEOL RESONANCE Strength: 600MHz Total number of times: 32 Solvent: CDCl3, DMSO-d6 Sample concentration: 30% by mass

[0336] 13 C-NMR: “JNM-ECA600” manufactured by JEOL RESONANCE Magnetic field strength: 150MHz Total number of times: 320 Solvent: DMSO-d6 Sample concentration: 30% by mass

[0337] FD-MS: JEOL Ltd. "JMS-T100GC AccuTOF" Measurement range: m / z = 50.00~2000.00 Rate of change: 25.6 mA / min Final current value: 40mA Cathode voltage: -10kV

[0338] GPC: HLC-8320GPC manufactured by Tosoh Corporation Column: Tosoh Corporation's "TSK-GEL G2000HXL" + "TSK-GEL G3000HXL" + "TSK-GEL G4000HXL" Detector: RI (Differential Refractive Index) Measurement conditions: 40℃ Mobile phase: tetrahydrofuran Flow rate: 1ml / min Standard: Tosoh Corporation's "PStQuick A", "PStQuick B", "PStQuick E", and "PStQuick F"

[0339] The epoxy equivalent of the synthesized epoxy resin was measured in accordance with JIS K7236, and the epoxy equivalent (g / eq) was calculated.

[0340] 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.

[0341] Synthesis Example 1 In a flask equipped with a thermometer, condenser, and stirrer, 420 g (2.0 equivalents) of 1,12-dodecandiol diglycidyl ether (manufactured by Yokkaichi Synthetic Co., Ltd.: epoxy equivalent 210 g / eq) and 240 g (2.1 equivalents) of bisphenol A (hydroxyl group equivalent 114 g / eq) were charged. The mixture was heated to 140°C for 30 minutes, and then 6.6 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, yielding 646 g of hydroxy compound (Ph-1). Mass spectrometry of this hydroxy compound (Ph-1) revealed a peak at M+=771, corresponding to the theoretical structure of m=1 in the structural formula (Ph-1) below, confirming the presence of the target hydroxy compound. The hydroxyl group equivalent of this hydroxy compound (Ph-1), calculated from GPC, was 2053 g / eq, and the average value of the repeating unit m was 6.9.

[0342] [ka]

[0343] Synthesis Example 2 The reaction was carried out in the same manner as in Synthesis Example 1, except that 420 g (2.0 equivalents) of diglycidyl ether of 1,12-dodecanediol (epoxy equivalent 210 g / eq) was replaced with 472 g (2.0 equivalents) of diglycidyl ether of 1,15-pentadecanediol (epoxy equivalent 236 g / eq), yielding 697 g of hydroxy compound (Ph-2). Mass spectrometry of this hydroxy compound (Ph-2) revealed a peak at M+=813, corresponding to the theoretical structure of m=1 in the structural formula (Ph-2) below, confirming the presence of the target hydroxy compound. The hydroxyl group equivalent of this hydroxy compound (Ph-2), calculated from GPC, was 2226 g / eq, and the average value of the repeating unit m was 6.8.

[0344] [ka]

[0345] Synthesis Example 3 The reaction was carried out in the same manner as in Synthesis Example 1, except that 420 g (2.0 equivalents) of 1,12-dodecandiol diglycidyl ether (epoxy equivalent 210 g / eq) was replaced with 380 g (2.0 equivalents) of 1,9-nonanediol diglycidyl ether (epoxy equivalent 190 g / eq), yielding 607 g of the hydroxy compound (Ph-3). Mass spectrometry of this hydroxy compound (Ph-3) revealed a peak with M+=729, corresponding to the theoretical structure of m=1 in the structural formula (Ph-3) below, confirming the presence of the target hydroxy compound. The hydroxyl group equivalent of this hydroxy compound (Ph-3), calculated from GPC, was 1989 g / eq, and the average value of the repeating unit m was 7.2.

[0346] [ka]

[0347] Synthesis Example 4 The reaction was carried out in the same manner as in Synthesis Example 1, except that 420 g (2.0 equivalents) of 1,12-dodecandiol diglycidyl ether (manufactured by Yokkaichi Synthetic Co., Ltd.: epoxy equivalent 210 g / eq) and 240 g (2.1 equivalents) of bisphenol A (hydroxyl group equivalent 114 g / eq) were replaced with 962 g (2.0 equivalents) of polypropylene glycol diglycidyl ether (manufactured by Nagase ChemteX, "Denacol EX-931": epoxy equivalent 481 g / eq) and 274 g (2.4 equivalents) of bisphenol A (hydroxyl group equivalent 114 g / eq). 1211 g of the hydroxy compound (Ph-4) was obtained. Mass spectrometry of this hydroxy compound (Ph-4) yielded a peak at M+=1226, corresponding to the theoretical structure of m=1, n2=11 in the structural formula (Ph-4) below, confirming the presence of the target hydroxy compound. The hydroxyl group equivalent of this hydroxy compound (Ph-4), calculated from GPC, was 1582 g / eq, and the average value of the repeating unit m was 3.3.

[0348] [ka]

[0349] Synthesis Example 5 The reaction was carried out in the same manner as in Synthesis Example 1, except that 420 g (2.0 equivalents) of 1,12-dodecandiol diglycidyl ether (manufactured by Yokkaichi Synthetic Co., Ltd.: epoxy equivalent 210 g / eq) and 240 g (2.1 equivalents) of bisphenol A (hydroxyl group equivalent 114 g / eq) were replaced with 890 g (2.0 equivalents) of polytetramethylene glycol diglycidyl ether (manufactured by Nagase ChemteX, "Denacol EX-991L": epoxy equivalent 445 g / eq) and 274 g (2.4 equivalents) of bisphenol A (hydroxyl group equivalent 114 g / eq), yielding 1140 g of the hydroxy compound (Ph-5). The presence of the target hydroxy compound (Ph-5) was confirmed by mass spectrometry, which yielded a peak with M+=1380 corresponding to the theoretical structure of m=1, n2=11 in the structural formula (Ph-5) shown below. The hydroxyl group equivalent of this hydroxy compound (Ph-5), calculated from GPC, was 2520 g / eq, and the average value of the repeating units m was 5.1.

[0350] [ka]

[0351] Synthesis Example 6 The reaction was carried out in the same manner as in Synthesis Example 1, except that 420 g (2.0 equivalents) of 1,12-dodecanediol diglycidyl ether (manufactured by Yokkaichi Synthetic Co., Ltd.: epoxy equivalent 210 g / eq) and 240 g (2.1 equivalents) of bisphenol A (hydroxyl group equivalent 114 g / eq) were replaced with 126.2 g (0.39 mol) of 1,6-hexanediol diglycidyl ether (manufactured by Sakamoto Pharmaceutical Co., Ltd. "SR-16H": epoxy equivalent 160 g / eq) and 78.1 g (0.08 mol) of polypropylene glycol diglycidyl ether (manufactured by Nagase ChemteX "Denacol EX-931": epoxy equivalent 481 g / eq) and 114.6 g (0.50 mol) of bisphenol A (hydroxyl group equivalent 114 g / eq), yielding 317 g of the hydroxy compound (Ph-6). The hydroxy compound (Ph-6) was found to contain the target hydroxy compound, as a mass spectrum analysis yielded a peak at M+=1684, corresponding to the theoretical structure of m1=1, m2=1, and n2=11 in the structural formula (Ph-6) shown below. The hydroxyl group equivalent of this hydroxy compound (Ph-6), calculated from GPC, was 1597 g / eq.

[0352] [ka]

[0353] Synthesis Example 7 The reaction was carried out in the same manner as in Synthesis Example 1, except that 420 g (2.0 equivalents) of 1,12-dodecanediol diglycidyl ether (manufactured by Yokkaichi Synthetic Co., Ltd.: epoxy equivalent 210 g / eq) and 240 g (2.1 equivalents) of bisphenol A (hydroxyl group equivalent 114 g / eq) were replaced with 136 g (0.43 mol) of 1,6-hexanediol diglycidyl ether (manufactured by Sakamoto Pharmaceutical Co., Ltd. "SR-16H": epoxy equivalent 160 g / eq) and 66 g (0.07 mol) of polytetramethylene glycol diglycidyl ether (manufactured by Nagase ChemteX "Denacol EX-991L": epoxy equivalent 445 g / eq) and 119.7 g (0.53 mol) of bisphenol A (hydroxyl group equivalent 114 g / eq), yielding 318 g of the hydroxy compound (Ph-7). The hydroxy compound (Ph-7) was found to contain the target hydroxy compound, as a mass spectrum analysis yielded a peak with M+=1839, corresponding to the theoretical structure of m1=1, m2=1, and n2=11 in the structural formula (Ph-7) shown below. The hydroxyl group equivalent of this hydroxy compound (Ph-7), calculated from GPC, was 1896 g / eq.

[0354] [ka]

[0355] Synthesis Example 8 In a flask equipped with a thermometer, dropping funnel, condenser, and stirrer, 205.3 g of the hydroxy compound (Ph-1) obtained in Synthesis Example 1, 647.5 g (7.0 mol) of epichlorohydrin, and 150 g of n-butanol were added and dissolved while purging with nitrogen gas. Then, the temperature was raised to 65°C, and the pressure was reduced to the azeotropic pressure, and 10.6 g (0.13 mol) 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, 15.0 g of 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 235 g of epoxy resin (Ep-1). The epoxy equivalent of the obtained epoxy resin (Ep-1) was 2320 g / eq. Mass spectrometry of this epoxy resin yielded a peak with M+=883, which corresponds to the theoretical structure of m=1, q=1, p1=0, p2=0 in the structural formula (Ep-1) below, thus confirming that it contains the target epoxy resin (Ep-1).

[0356] [ka]

[0357] Synthesis Example 9 The reaction was carried out in the same manner as in Synthesis Example 8, except that 205.3 g of hydroxy compound (Ph-1) was replaced with 222.6 g of hydroxy compound (Ph-2), yielding 251 g of epoxy resin (Ep-2). The epoxy equivalent of the obtained epoxy resin (Ep-2) was 2510 g / eq. Mass spectrometry of this epoxy resin yielded a peak at M+=925, corresponding to the theoretical structure of m=1, p1=0, p2=0, q=1 in the following structural formula (Ep-2), thus confirming that it contains the target epoxy resin (Ep-2).

[0358] [ka]

[0359] Synthesis Example 10 The reaction was carried out in the same manner as in Synthesis Example 8, except that 205.3 g of hydroxy compound (Ph-1) was replaced with 198.9 g of hydroxy compound (Ph-3), yielding 229 g of epoxy resin (Ep-3). The epoxy equivalent of the obtained epoxy resin (Ep-3) was 2250 g / eq. Mass spectrometry of the epoxy resin showed a peak with M+=841, corresponding to the theoretical structure of m=1, p1=0, p2=0, q=1 in the following structural formula (Ep-3), confirming that the epoxy resin contained the target epoxy resin (Ep-3).

[0360] [ka]

[0361] Synthesis Example 11 The reaction was carried out in the same manner as in Synthesis Example 8, except that 205.3 g of hydroxy compound (Ph-1) was replaced with 158.2 g of hydroxy compound (Ph-4), yielding 193 g of epoxy resin (Ep-4). The epoxy equivalent of the obtained epoxy resin (Ep-4) was 1802 g / eq. Mass spectrometry of this epoxy resin yielded a peak at M+=1336, corresponding to the theoretical structure of m=1, n2=11, p1=0, p2=0, q=1 in the following structural formula (Ep-4), thus confirming that it contains the target epoxy resin (Ep-4).

[0362] [ka]

[0363] Synthesis Example 12 The reaction was carried out in the same manner as in Synthesis Example 8, except that 205.3 g of hydroxy compound (Ph-1) was replaced with 252.0 g of hydroxy compound (Ph-5), yielding 277 g of epoxy resin (Ep-5). The epoxy equivalent of the obtained epoxy resin (Ep-5) was 2834 g / eq. Mass spectrometry of this epoxy resin yielded a peak at M+=1492, corresponding to the theoretical structure of m=1, n2=11, p1=0, p2=0, q=1 in the following structural formula (Ep-5), thus confirming that it contains the target epoxy resin (Ep-5).

[0364] [ka]

[0365] Synthesis Example 13 The reaction was carried out in the same manner as in Synthesis Example 8, except that 205.3 g of hydroxy compound (Ph-1) was replaced with 198.4 g of hydroxy compound (Ph-6), yielding 229 g of epoxy resin (Ep-6). The epoxy equivalent of the obtained epoxy resin (Ep-6) was 2244 g / eq. Mass spectrometry of this epoxy resin yielded a peak at M+=1796, corresponding to the theoretical structure of m1=1, m2=2, n2=11, p1=0, p2=0, q=1 in the following structural formula (Ep-6), thus confirming that it contains the target epoxy resin (Ep-6).

[0366] [ka]

[0367] Synthesis Example 14 The reaction was carried out in the same manner as in Synthesis Example 8, except that 205.3 g of the hydroxy compound (Ph-1) was replaced with 191.4 g of the hydroxy compound (Ph-7), yielding 223 g of epoxy resin (Ep-7). The epoxy equivalent of the obtained epoxy resin (Ep-7) was 2167 g / eq. Mass spectrometry of this epoxy resin revealed a peak at M+=1951, corresponding to the theoretical structure of m1=1, m2=2, n2=11, p1=0, p2=0, q=1 in the following structural formula (Ep-7), thus confirming that it contains the target epoxy resin (Ep-7).

[0368] [ka]

[0369] Synthesis Example 15 In a flask equipped with a thermometer, stirrer, and condenser, 159.2 g of 1,6'-bismaleimide-(2,2,4-trimethyl)hexane (BMI-THM, manufactured by Yamato Chemical Industries, Ltd.), 154.2 g of furfurylglycidyl ether (manufactured by Sigma-Aldrich), and 400 g of tetrahydrofuran were charged. After purging with nitrogen, the mixture was reacted at 60°C for 12 hours. Subsequently, tetrahydrofuran was removed by vacuum distillation to obtain 298 g of the glycidyl ether group-containing compound (D-1). The mass spectrum of this glycidyl ether group-containing compound showed a peak with M+=627, confirming that it contained the target compound, glycidyl ether group-containing compound (D-1). The epoxy equivalent was 330 g / eq.

[0370] [ka]

[0371] Synthesis Example 16 The reaction was carried out in the same manner as in Synthesis Example 15, except that 159.2 g of 1,6'-bismaleimide-(2,2,4-trimethyl)hexane (BMI-THM, manufactured by Yamato Chemical Industries, Ltd.) was replaced with 179.2 g of 4,4'-diphenylmethanebismaleimide (BMI-THM, manufactured by Yamato Chemical Industries, Ltd.), yielding 317 g of the glycidyl ether group-containing compound (D-2). The mass spectrum of this glycidyl ether group-containing compound showed a peak with M+=667, confirming that it contained the target compound, glycidyl ether group-containing compound (D-2). The epoxy equivalent was 351 g / eq.

[0372] [ka]

[0373] Synthesis Example 17 The reaction was carried out in the same manner as in Synthesis Example 15, except that 159.2 g of 1,6'-bismaleimide-(2,2,4-trimethyl)hexane (BMI-THM, manufactured by Yamato Chemical Industries, Ltd.) was replaced with 285.3 g of bisphenol A diphenyl ether bismaleimide (BMI-4000, manufactured by Yamato Chemical Industries, Ltd.), yielding 417 g of the glycidyl ether group-containing compound (D-3). The mass spectrum of this glycidyl ether group-containing compound showed a peak with M+=879, confirming that it contained the target compound, glycidyl ether group-containing compound (D-3). The epoxy equivalent was 463 g / eq.

[0374] [ka]

[0375] Synthesis Example 18 The reaction was carried out in the same manner as in Synthesis Example 15, except that 159.2 g of 1,6'-bismaleimide-(2,2,4-trimethyl)hexane (BMI-THM, manufactured by Yamato Chemical Industries, Ltd.) was replaced with 221.3 g of 3,3'-dimethyl 5,5'-diethyl-4,4'-diphenylmethanebismaleimide (BMI-5100, manufactured by Yamato Chemical Industries, Ltd.), yielding 357 g of the glycidyl ether group-containing compound (D-4). The mass spectrum of this glycidyl ether group-containing compound showed a peak with M+=751, confirming that it contained the target compound, glycidyl ether group-containing compound (D-4). The epoxy equivalent was 395 g / eq.

[0376] [ka]

[0377] Examples 1 to 28 and Comparative Examples 1 to 6: Preparation of compositions and cured products Each compound was used in the formulations shown in Tables 1 and 2 (numbers in the tables are based on mass) and uniformly mixed in a mixer (Awatori Rentaro ARV-200, manufactured by Thinky Co., Ltd.) to obtain a curable resin composition. This curable resin composition was sandwiched between aluminum mirror plates (JIS H 4000 A1050P, manufactured by Engineering Test Service Co., Ltd.) with a silicone tube as a spacer, and heat curing was performed under predetermined conditions to obtain a cured product with a thickness of 0.7 mm.

[0378] <Tensile elongation> The hardened material was punched out into a dumbbell shape (JIS K 7161-2-1BA) using a punching blade, and these were used as test specimens. Tensile tests were performed on these specimens using a tensile testing machine (Shimadzu Corporation "Autograph AG-IS") in accordance with JIS K 7162-2, and the elongation at the breaking point at a measurement environment of 23°C was evaluated (test speed: 2 mm / min).

[0379] <Evaluation of adhesion and dismantling properties> Each compound was used in the formulations shown in Tables 1 and 2 (numbers in the tables are based on mass) and uniformly mixed in a mixer (Awatori Rentaro ARV-200, manufactured by Thinky Co., Ltd.) to obtain a curable resin composition. This resin composition was applied to one of two cold-rolled steel sheets (SPCC-SD, manufactured by TP Giken Co., Ltd., 1.0 mm × 25 mm × 100 mm), glass beads (J-80, manufactured by Potters Barotini Co., Ltd.) were added as spacers, and the other SPCC-SD sheet was bonded to it (bonding area: 25 mm × 12.5 mm). This was then heat-cured at the temperatures shown in Tables 1 and 2 to obtain shear test specimens. The adhesion was evaluated by performing tensile shear tests on these specimens. The tests were conducted in accordance with JIS K 6850, and the maximum point stress at a measurement environment of 23°C was compared. • Initial adhesive strength: Shear tests were performed on the prepared test specimens without any special treatment. • Adhesion strength after heating: The prepared test specimens were heated in a heating dryer at 200°C for 30 minutes, and then the substrate was cooled to room temperature before a shear test was performed. • Demolition evaluation: The rate of strength reduction was calculated using the formula "(Initial adhesive strength - Adhesion strength after heating) / Initial adhesive strength × 100". • Evaluation of reproducibility of disassembly: The standard deviation of "adhesion strength after heating" was evaluated according to the following criteria: A: Standard deviation less than 0.5 MPa (extremely good reproducibility) B: Standard deviation of 0.5 MPa or more, but less than 1.5 MPa (good reproducibility) C: Standard deviation of 1.5 MPa or higher (poor reproducibility) -: Evaluation not performed because the strength reduction rate is less than 10% (no demolition function). The maximum point stress at a measurement environment of 23°C was compared.

[0380] <Structural periodicity> Cross-sections of the cured resin were prepared using an ultramicrotome, and the structural periodicity was observed. The observation method used was scanning electron microscopy (SEM) to ensure clear identification of morphological contrast.

[0381] SEM Model used: JEOL JSM-7800F Acceleration voltage: 5kV

[0382] [Table 1]

[0383] [Table 2]

[0384] The ingredients listed in the table are as follows: E-850S: Bisphenol A type liquid epoxy resin (manufactured by DIC Corporation, epoxy equivalent 188 g / eq) DICY: Dicyandiamide (DICY7, manufactured by Mitsubishi Chemical Corporation) DCMU: 3-(3,4-dichlorophenyl)-1,1-dimethylurea) (manufactured by DIC Corporation, “B-605-IM”) DTA: Diethylenetriamine (manufactured by Kanto Chemical Co., Ltd.) F-260D, F-190D: Thermal expansion capsule (Matsumoto Oil & Fat Pharmaceutical Co., Ltd.) 953240L: Thermally expanding graphite (Ito Graphite Industry) EXP 50S150: Thermally Expandable Graphite (Fuji Graphite Industry)

[0385] Examples 1 to 28 showed good results in terms of flexibility, initial adhesive strength, rate of strength reduction during additional heating, and reproducibility of the decomposition function. In this system, the expansion of the expanding material during heating induces the breakdown of the adhesive layer and a reduction in the adhesive area at the adhesive layer / substrate interface, thus exhibiting easy decomposition not only during the heating operation but also after returning to room temperature.

[0386] Furthermore, this system possesses a phase-separated structure, suggesting that the reversible bonding units are unevenly distributed within the adhesive layer. The uneven distribution of the reversible bonding structure within the flexible ocean phase enhances the dissociation effect of the Retro-Diels-Alder reaction during heating. As a result, it is hypothesized that this induces softening and embrittlement of the adhesive layer during heating, further promoting the expansion effect of the expansion capsule, ultimately leading to improved reproducibility of easy disassembly.

[0387] Comparative Examples 1 and 4 did not exhibit decomposition functionality because their compositions did not contain any expanding material. It is believed that while reversible bond dissociation (Retro-Diels-Alder reaction) occurs during heating, the bonds are reformed (Diels-Alder reaction) during the cooling process to room temperature, resulting in the lack of decomposition under room temperature conditions.

[0388] Comparative Examples 2 and 5 showed significant variations in adhesive strength when the adherends were further heated, resulting in a failure to reproducibly achieve the decomposition function. Comparative Examples 2 and 5 did not contain reversible bonds, and it is presumed that the function was not sufficiently expressed by the effect of the expansive agent alone.

[0389] Comparative Examples 3 and 6 showed very low flexibility and initial adhesive strength in the cured products. In the Examples, the phase separation structure between epoxy resin (A) and epoxy resin (B) provided both flexibility and adhesion, but in Comparative Examples 3 and 6, the phase separation structure did not manifest, and it is thought that this prevented the development of flexibility and adhesion.

Claims

1. A cured product obtained by curing an epoxy resin composition, The epoxy resin composition An epoxy resin (A) having an epoxy equivalent of 500 to 10,000 g / eq represented by the following general formula (1), Epoxy resin (B) with an epoxy equivalent of 100-300 g / eq, A glycidyl ether group-containing compound (C) represented by the following general formula (4) and having a molecular weight of less than 1000, Thermally expandable particles (D), Compound (I) that is reactive with the glycidyl ether group-containing compound (C), It contains, The hardened material includes a sea-island structure. A cured product characterized by the following features. 【Chemistry 1】 [In formula (1), each Ar independently has a structure that is either unsubstituted or has a 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), 【Chemistry 2】 [In equations (2) and (3), Ar is the same as described above.] R １ , R ２ Each of these is independently a hydrogen atom, a methyl group, or an ethyl group. R' is a divalent hydrocarbon group with 2 to 12 carbon atoms. R ３ , R ４ , 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 are each independently a hydrogen atom or a methyl group, n1 is an integer between 4 and 16. n² is the average value of the repeating units, ranging 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 repeated average values, m1 and m2 are independently between 0 and 25, and m1 + m2 ≥ 1. p1 and p2 are independently between 0 and 5. q is between 0.5 and 5. However, the bonding between X represented by general formula (2) and Y represented by 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. 【Transformation 3】 [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 identical or different. 【Chemistry 4】 [The aromatic ring in formula (5) may be substituted or unsubstituted, and * represents a bond point. G is a glycidyl group or a 2-methylglycidyl group, and the -OG on the naphthalene ring in the formula indicates that it may be bonded at any location.] 【Transformation 5】 (In formula (6), R'' is independently a hydrogen atom, a methyl group, or an ethyl group; n1 is an integer from 1 to 30; n2 is the average value of the number of repetitions, from 0.5 to 8; n3 is the average value of the number of repetitions, from 0.5 to 6; and * represents a bond point.)

2. The cured product according to claim 1, wherein the compound (I) that is reactive with the glycidyl ether group-containing compound (C) is a hydroxyl group-containing compound or an amine group-containing compound.

3. The cured product according to claim 1 or 2, wherein the concentration of reversible bonds in the glycidyl ether group-containing compound (C) relative to the total mass of curable components in the epoxy resin composition is 0.10 mmol / g or more.

4. The cured product according to claim 1 or 2, wherein the mass ratio (A):(B) of the epoxy resin (A) to the epoxy resin (B) is 90:10 to 10:

90.

5. The cured product according to claim 1 or 2, wherein the thermally expandable particles (D) are at least one selected from the group consisting of thermally expandable microcapsules and thermally expandable graphite.

6. The cured product according to claim 1 or 2, wherein the proportion of the thermally expandable particles (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).

7. A laminate comprising a base material and a layer containing the cured product described in claim 1 or 2.

8. A heat-resistant member containing the cured product described in claim 1 or 2.

9. A demolition method using a demolition-compatible adhesive material, The disassemblable adhesive material comprises the epoxy resin composition described in claim 1, A bonding step of attaching the disassemblable adhesive material to the surface of the adherend and joining it to the adherend, A curing step to cure the aforementioned disassemblable adhesive material and obtain a cured product, A heat treatment step is performed on the cured product to thermally dissociate the reversible bonds contained in the general formula (4) derived from the glycidyl ether group-containing compound (C) and to expand the thermally expandable particles (D), The process includes a dismantling step of separating the adherend and the cured material, The hardened material includes a sea-island structure. Disassembly method.

10. The demolition method according to claim 9, further comprising a cooling step of cooling the heat-treated hardened material to room temperature after the heat treatment step and before the demolition step.

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