Epoxy resin composition, cured product thereof, and laminate

Abstract

The present invention aims to provide an epoxy resin composition which can be suitably used as a structural adhesive or the like, the structural adhesive being excellent in flexibility against deformation and adhesion to a substrate, and easily achieving easy disintegration after use. Specifically, an epoxy resin composition is used, which contains an epoxy resin (A) having an epoxy equivalent of 500 to 10,000 g / eq, an epoxy resin (B) having an epoxy equivalent of 100 to 300 g / eq, and a heat-expandable particle (C), the epoxy resin (A) being represented by the following formula (1) (Ar is an aromatic ring; X is a structural unit having an alkylene chain; Y is a structural unit having a polyether chain; R 11 , R 12 is a glycidyl ether group or a 2-methyl glycidyl ether group; R 13 , R 14 is a hydroxyl group, a glycidyl ether group or a 2-methyl glycidyl ether group; R 15 , R 16 is a hydrogen atom or a methyl group; m1, m2 are 0 to 25, and m1+m2≥1; p1, p2 are 0 to 5; q is 0.5 to 5.

Description

Technical Field

[0001] The present invention relates to epoxy resin compositions comprising epoxy resin having a specific structure, cured products thereof, and laminates containing layers formed from the cured products thereof. Background Technology

[0002] From the perspective of reducing carbon dioxide emissions and improving fuel efficiency, technologies related to lightweighting in automobiles and aircraft are expected to achieve lightweighting, such as gradually reducing the number of welds and combining CFRP and metals. To achieve this goal, high-performance adhesives for structural materials are essential, especially in the heat bonding of aluminum and CFRP, where there is a large difference in thermal expansion. Warping and ripple caused by interfacial stress accompanying expansion and contraction are considered problems, requiring adhesives that can relax stress.

[0003] On the other hand, achieving high adhesive performance has also led to the emergence of products that are difficult to reuse, limiting their disassembly and reusability after use. Against the backdrop of recent increased environmental awareness, it has become important to develop adhesives that maintain high adhesive performance and can be easily peeled off after use.

[0004] Against this backdrop, the development of easily disintegrating adhesives is actively underway. Generally, the thermal melting of thermoplasticized resins is frequently used, but in recent years, the following techniques have also been proposed: techniques that reduce adhesive strength and facilitate peeling by premixing thermally expanding materials and thermally decomposable compounds into thermosetting resins and then applying heat after use (see, for example, Patent Documents 1 and 2).

[0005] However, in the technology of the aforementioned Patent Document 1, existing epoxy resin compositions are basically used as adhesives, making it difficult to fully utilize the thermally expanding materials within the cured product (adhesive layer) to exhibit sufficient foaming. As a result, sometimes the peelability is insufficient or the adhesive layer cannot be perfectly removed due to its brittleness. Furthermore, in the technology of the aforementioned Patent Document 2, the pre-containment of thermally decomposable compounds presents a complexity in terms of usage, requiring highly controlled heating temperatures during the curing reaction. Especially when using highly thermally conductive metal substrates, the possibility of adverse effects due to excessive heating of the adhesive in unexpected locations cannot be ruled out.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2003-286464

[0009] Patent Document 2: Japanese Patent Application Publication No. 2013-256557 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] In view of the above, the objective of the present invention is to provide an epoxy resin composition that can be suitably used as a structural adhesive, etc., wherein the structural adhesive has strong resistance to deformation, excellent flexibility and adhesion to the substrate, and can be easily disassembled after use.

[0012] Solution for solving the problem

[0013] Through in-depth research, the inventors discovered that by using an epoxy resin with a specific structure and by mixing thermally expandable particles into the resin composition, the aforementioned problems could be solved, thus completing the invention.

[0014] That is, the present invention provides an epoxy resin composition, its cured product, and a laminate having the cured product as an adhesive layer, wherein the epoxy resin composition is characterized in that it contains:

[0015] The epoxy resin (A) shown in the following general formula (1) has an epoxy equivalent of 500 to 10,000 g / eq;

[0016] Epoxy resin (B) with an epoxy equivalent of 100–300 g / eq; and

[0017] Thermally expandable particles (C).

[0018]

[0019] In formula (1), Ar is independently a structure containing an aromatic ring that is either unsubstituted or has a substituent;

[0020] X is the structural unit shown in the following general formula (2); Y is the structural unit shown in the following general formula (3);

[0021]

[0022] In equations (2) and (3), Ar is the same as described above;

[0023] R1 and R2 are each independently a hydrogen atom, a methyl group, or an ethyl group;

[0024] R' is a divalent hydrocarbon group with 2 to 12 carbon atoms;

[0025] R3, R4, R7, and R8 are each independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group;

[0026] R5, R6, R9, R 10 Each can be independently a hydrogen atom or a methyl group;

[0027] n1 is an integer from 4 to 16;

[0028] n² is calculated as the average value of the repeating units, ranging from 2 to 30.

[0029] R 11 R 12 Each is independently a glycidyl ether group or a 2-methylglycidyl ether group;

[0030] R 13 R 14 Each can be independently a hydroxyl, glycidyl ether, or 2-methylglycidyl ether group;

[0031] R 15 R 16 It can be a hydrogen atom or a methyl group;

[0032] m1, m2, p1, p2, and q are the average values ​​of repeated samples;

[0033] m1 and m2 are each independently between 0 and 25, and m1 + m2 ≥ 1;

[0034] p1 and p2 are each independently 0 to 5;

[0035] q is 0.5 to 5.

[0036] Wherein, the bonding between X represented by the aforementioned general formula (2) and Y represented by the aforementioned general formula (3) can be arbitrarily chosen as random or block, and the total number of each structural unit X and Y present in one molecule is m1 and m2, respectively.

[0037] The effects of the invention

[0038] According to the present invention, by using an epoxy resin having a long-chain alkylene chain or a polyether chain in one molecule, the cured product can possess both flexibility based on elastic deformation and high adhesion to a substrate. Furthermore, by including thermally expandable particles, thermal expansion can be effectively exhibited in the cured product (adhesive layer) after use due to its high flexibility, resulting in easy disintegration (peelability). For these reasons, the epoxy resin composition of the present invention can be suitable for use as a structural adhesive, etc. Detailed Implementation

[0039] The present invention is characterized in that it contains:

[0040] The epoxy resin (A) with an epoxy equivalent of 500 to 10000 g / eq is represented by the following general formula (1);

[0041] Epoxy resin (B) with an epoxy equivalent of 100–300 g / eq; and

[0042] Thermally expandable particles (C).

[0043]

[0044] In formula (1), Ar is independently a structure containing an aromatic ring that is either unsubstituted or has a substituent;

[0045] X is the structural unit shown in the following general formula (2); Y is the structural unit shown in the following general formula (3);

[0046]

[0047] In equations (2) and (3), Ar is the same as described above;

[0048] R1 and R2 are each independently a hydrogen atom, a methyl group, or an ethyl group;

[0049] R' is a divalent hydrocarbon group with 2 to 12 carbon atoms;

[0050] R3, R4, R7, and R8 are each independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group;

[0051] R5, R6, R9, R 10 Each can be independently a hydrogen atom or a methyl group;

[0052] n1 is an integer from 4 to 16;

[0053] n² is calculated as the average value of the repeating units, ranging from 2 to 30.

[0054] R 11 R 12 Each is independently a glycidyl ether group or a 2-methylglycidyl ether group;

[0055] R 13 R 14 Each can be independently a hydroxyl, glycidyl ether, or 2-methylglycidyl ether group;

[0056] R 15 R 16 It can be a hydrogen atom or a methyl group;

[0057] m1, m2, p1, p2, and q are the average values ​​of repeated samples;

[0058] m1 and m2 are each independently between 0 and 25, and m1 + m2 ≥ 1;

[0059] p1 and p2 are each independently 0 to 5;

[0060] q is 0.5 to 5.

[0061] Wherein, the bonding between X represented by the aforementioned general formula (2) and Y represented by the aforementioned general formula (3) can be arbitrarily chosen as random or block, and the total number of each structural unit X and Y present in one molecule is m1 and m2, respectively.

[0062] The aforementioned epoxy resin (A) contains structural unit X of general formula (2) and / or structural unit Y of general formula (3) in its structure. The presence of alkylene chains or polyether chains in each structural unit enables the cured product to exhibit high flexibility. In particular, the flexibility achieved by the alkylene chains allows it to follow the thermal expansion of the substrate when used as an adhesive. In addition, the polyether chains have the effect of reducing the viscosity of the epoxy resin (A) itself, which helps to improve the coatability and processability of the epoxy resin composition.

[0063] In the aforementioned epoxy resin (A), structural units X and Y can be contained individually, or both structural units X and Y can be present in one molecule. In this case, X and Y can be block bonds or random bonds, indicating that the total number of structural units X and structural units Y contained in one molecule are m1 and m2, respectively.

[0064] Ar in general formula (1) representing the aforementioned epoxy resin (A), Ar in general formula (2) representing structural unit X, and Ar in general formula (3) representing structural unit Y are all structures containing an aromatic ring that is unsubstituted or has a substituent. There is no particular limitation on the aromatic ring, and examples such as benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, and fluorene ring can be listed.

[0065] Of these, Ar is preferably any structure shown in the following structural formula (4).

[0066]

[0067] [The aromatic ring in formula (4) may be substituted or unsubstituted, and * indicates a bond site.]

[0068] Alternatively, Ar can also be represented by the following structures.

[0069]

[0070] (In the formula, the aromatic ring may be substituted or unsubstituted. n3 = 1 to 4, * indicates a bond site.)

[0071] The aromatic ring of Ar may be optionally substituted or unsubstituted. When Ar has substituents, preferred substituents include alkyl groups, halogen atoms, glycidyl ether groups, and 2-methylglycidyl ether groups. Unsubstituted substituents, or alkyl, glycidyl ether, or 2-methylglycidyl ether groups, are preferred. The number of substituents on each aromatic ring is preferably two or less, more preferably one or less, and particularly preferably unsubstituted.

[0072] As for the aforementioned Ar structure, the following structure is particularly preferred. * indicates a bonding point.

[0073]

[0074] The following structures are particularly preferred for Ar with substituents. * indicates a bond site.

[0075]

[0076] In the structural unit X shown in the aforementioned general formula (2), the repeating unit n1 is an integer from 4 to 16. By making n1 4 or more, the adhesive strength is improved, and the deformation mode of the cured product exhibits elastic deformation. In addition, by making n1 16 or less, the decrease in crosslinking density can be suppressed. Preferably, it is 4 to 15, and more preferably 6 to 12.

[0077] In the structural unit X shown in the aforementioned general formula (2), R1 and R2 are each independently hydrogen atoms, methyl or ethyl, R3 and R4 are each independently hydroxyl, glycidyl ether or 2-methylglycidyl ether, and R5 and R6 are each independently hydrogen atoms or methyl.

[0078] Among these, R3 and R4 are preferably hydroxyl groups, and R5 and R6 are preferably hydrogen atoms.

[0079] In the structural unit Y shown in the aforementioned general formula (3), n2 is 2 to 30, calculated as the average value of the repeating units. This range is preferred from the viewpoint that a good balance is achieved between the viscosity of the epoxy resin (A) and the crosslinking density of the resulting cured product. Preferably, it is 2 to 25, and more preferably 4 to 20.

[0080] In the structural unit Y shown in the aforementioned general formula (3), R' is a divalent hydrocarbon group with 2 to 12 carbon atoms. If it is within this range, the adhesive strength is improved, and the deformation mode of the cured product exhibits elastic deformation. R' is preferably a divalent hydrocarbon group with 2 to 6 carbon atoms.

[0081] As for the aforementioned divalent hydrocarbon group, there are no particular limitations, and examples include straight-chain or branched alkylene, alkenylene, ynylene, cycloalkylene, arylene, and arylalkylene (which have divalent groups of alkylene and arylene).

[0082] Examples of alkylene groups include methylene, ethylene, propyleneene, butylene, pentylene, hexylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene. Examples of alkenylene groups include vinylene, 1-methylvinylene, propenylene, butenylene, and pentenylene. Examples of ynynylene groups include ethynylene, propynylene, butynylene, pentylene, and hexynylene. Examples of cycloalkylene groups include cyclopropylene, cyclobutylene, cyclopentylene, and cyclohexylene. Examples of arylene groups include phenylene, tolylene, diphenylene, and naphthylene.

[0083] Among these, from the viewpoint of balancing the ease of obtaining raw materials, the viscosity of the resulting epoxy resin (A), and the flexibility when making the cured product, ethylene, propylene, and tetramethylene are preferred.

[0084] In the structural unit Y shown in the aforementioned general formula (3), R7 and R8 are each independently a hydroxyl group, a glycidyl ether group, or a 2-methylglycidyl ether group, and R9 and R 10 Each is independently a hydrogen atom or a methyl group. As R7 and R8, a hydroxyl group is preferred, and as R9 and R... 10 Preferably, it contains hydrogen atoms.

[0085] As described above, the epoxy resin (A) used in this invention is represented by the aforementioned general formula (1). In the aforementioned general formula (1), m1 and m2 are the repeated average values ​​of the aforementioned structural unit X and structural unit Y, respectively, each independently ranging from 0 to 25, and m1 + m2 ≥ 1.

[0086] In addition, R in the aforementioned general formula (1) 11 R 12 Each is independently a glycidyl ether group or a 2-methylglycidyl ether group, R 13 R 14 Each is independently a hydroxyl, glycidyl ether, or 2-methylglycidyl ether group, R 15 R 16 For hydrogen atoms or methyl groups, p1, p2, and q are repeated averages, where p1 and p2 are independently 0–5, and q is 0.5–5. Among these, R 11 R 12 Preferably, it is a glycidyl ether group, R 13 R 14 Preferably, hydroxyl group, R 15 R 16 Hydrogen atoms are preferred. Furthermore, p1 and p2 are preferably 0 to 2, and q is preferably 0.5 to 2.

[0087] Furthermore, the epoxy equivalent of the epoxy resin (A) used in this invention is 500 to 10,000 g / eq. Within this range, the resulting cured product exhibits an excellent balance between flexibility and crosslinking density. From the viewpoint of ease of handling and a further balance between flexibility and crosslinking density, a range of 600 to 8,000 g / eq is preferred, and a range of 800 to 5,000 g / eq is more preferably preferred.

[0088] Among the epoxy resins (A) of the present invention, resins having both the aforementioned structural unit X and structural unit Y in one molecule can be exemplified by the following structural formulas.

[0089]

[0090]

[0091]

[0092] In the above structural formulas (A-1) to (A-12), ran represents random bonding; 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 2 to 30 based on the average value of the repeating units; m1, m2, p1, p2, and q are the average values ​​of the repeating units; m1 and m2 are each independently 0.5 to 25; p1 and p2 are each independently 0 to 5; and q is 0.5 to 5. The repeating units present in the repeating units can be chosen to be the same or different from each other.

[0093] Among the above structural formulas, from the viewpoint of obtaining a better balance of physical properties of the solidified product, the substances shown in the aforementioned structural formulas (A-1), (A-2), (A-3), (A-5), (A-7), (A-8), and (A-9) are most preferably used.

[0094] Among the aforementioned epoxy resins (A), examples of epoxy resins having the aforementioned structural unit X include those shown in the following structural formula.

[0095]

[0096]

[0097]

[0098] 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 0.5 to 25; p1 and p2 are each independently 0 to 5; and q is 0.5 to 5. The repeating units within the repeating unit can be chosen to be the same or different from each other.

[0099] Among the above structural formulas, from the viewpoint of obtaining a better balance of physical properties of the solidified product, the substances shown in the aforementioned structural formulas (A-13), (A-14), (A-15), (A-17), (A-19), (A-20), and (A-21) are preferred.

[0100] Among the aforementioned epoxy resins (A), examples of epoxy resins having the aforementioned structural unit Y include those shown in the following structural formula.

[0101]

[0102]

[0103]

[0104] 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 2 to 30 based on the average value of the repeating units; m2, p1, p2, and q are the average values ​​of the repeating units; m2 is 0.5 to 25; p1 and p2 are each independently 0 to 5; and q is 0.5 to 5. The repeating units present in the repeating units can be chosen to be the same or different from each other.

[0105] Among the above structural formulas, from the viewpoint of obtaining a better balance of physical properties of the solidified product, the substances shown in the aforementioned structural formulas (A-25), (A-26), (A-27), (A-29), (A-31), (A-32), and (A-33) are most preferably used.

[0106] The method for manufacturing the aforementioned epoxy resin (A) used in this invention is not particularly limited. From the viewpoint of easy access to raw materials and reaction, the preferred method is, for example, the following: a diglycidyl ether (a1) of a dihydroxy compound having an alkylene chain or a polyether chain is reacted with an aromatic hydroxy compound (a2) in a molar ratio (a1) / (a2) of 1 / 1.01 to 1 / 5.0 to obtain a hydroxy compound [equivalent to a precursor or intermediate of epoxy resin (A)], and then reacted with an epihaloalcohol (a3).

[0107] In the aforementioned reaction in which a diglycidyl ether (a1) of a dihydroxy compound having an alkylene chain or a polyether chain reacts with an aromatic hydroxy compound (a2) to obtain a hydroxy compound, the product sometimes contains unreacted aromatic hydroxy compound (a2). However, when synthesizing the epoxy resin (A) used in this invention, it can be directly supplied to the reaction with epihaloalcohol (a3) ​​as a subsequent step. Alternatively, the unreacted aromatic hydroxy compound (a2) can be removed. From the viewpoint of balancing the strength and flexibility of the cured product obtained from the epoxy resin composition of this invention containing the obtained epoxy resin (A), the presence rate of the aforementioned unreacted aromatic hydroxy compound (a2) in the hydroxy compound supplied to the subsequent step is preferably in the range of 0.1% to 30% by mass.

[0108] The method for removing the unreacted aromatic hydroxyl compound (a2) is not particularly limited and can be carried out by various methods. Examples include column chromatography separation utilizing polarity differences, distillation fractionation utilizing boiling point differences, and alkaline water extraction utilizing differences in solubility in alkaline water. Among these, since there is no thermal degradation, alkaline water extraction is preferred from the viewpoint of efficiency. In this case, the organic solvent used to dissolve the target compound can be a solvent that is immiscible with water, such as toluene or methyl isobutyl ketone. From the viewpoint of solubility with the target compound, methyl isobutyl ketone is particularly preferred.

[0109] The diglycidyl ether (a1) that is a dihydroxy compound having an alkylene chain or a polyether chain is not particularly limited. Examples of diglycidyl ethers having an alkylene chain 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. In addition, examples of diglycidyl ethers having polyether chains 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 hydroxyl compounds, or they may contain organochlorine compounds such as 1-chloromethyl-2-glycidyl ether (chloromethyl body) as shown in the following structure. These diglycidyl ethers can be used alone or in combination of two or more.

[0110]

[0111] Among these, from the viewpoint of achieving an excellent balance between the softness and heat resistance of the resulting cured product, 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.

[0112] In addition, by reacting the aforementioned diglycidyl ether having an alkylene chain and the diglycidyl ether having a polyether chain simultaneously with an aromatic hydroxyl compound (a2), a hydroxyl compound having both structural unit X and structural unit Y can be obtained. By further reacting it with an epihaloalcohol (a3), an epoxy resin (A) having both structural unit X and structural unit Y can be obtained.

[0113] The aforementioned aromatic hydroxyl compound (a2) is not particularly limited, and examples include, for instance, 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; and 1,1'-methylenebis(2,7-naphthalenediol), 1,1'-dihydroxynaphthalene, etc., obtained by coupling reactions of dihydroxynaphthalenes. Tetrafunctional phenols such as 2,2',7,7'-tetraol and 1,1'-oxybis(2,7-naphthyldiol); bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, and bis(4-hydroxyphenyl)sulfone; bisphenols such as 2,2'-biphenol, 4,4'-biphenol, (1,1'-biphenyl)-3,4-diol, 3,3'-dimethyl-(1,1'-biphenyl)-4,4'-diol, and 3-methyl Biphenyls such as 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, and 4'-methyl-(1,1'-biphenyl)-3,4'-diol; phenols containing alicyclic structures, such as addition polymers of phenol with dicyclopentadiene and addition polymers of phenol with terpene compounds; bis(2-hydroxy-1-naphthyl)methane and bis(2-hydroxy-1-naphthyl)methane. Naphthols such as naphthyl propane; the condensation reaction product of phenol with phenylene dimethyl chloride or biphenylene dimethyl chloride, namely the so-called neophenolic phenolic resin, can be used alone or in combination of two or more. Furthermore, compounds with structures in which methyl, tert-butyl, or halogen atoms are substituted as substituents on the aromatic nucleus of the above-mentioned compounds can also be listed. In addition, the aforementioned phenols containing alicyclic structures and the aforementioned neophenolic phenolic resins can contain not only difunctional components but also components with trifunctionality or higher. In this invention, they can be used directly, or they can undergo a purification process such as column chromatography to extract only the difunctional components for use.

[0114] Among these, bisphenols are preferred from the viewpoint of achieving an excellent balance between softness and toughness when the cured product is produced, and especially from the viewpoint of significantly imparting toughness, bis(4-hydroxyphenyl)methane and 2,2-bis(4-hydroxyphenyl)propane are preferred. Furthermore, when the curing properties and heat resistance of the cured product are important, dihydroxynaphthalenes are preferred, and especially from the viewpoint of significantly imparting rapid curing properties, 2,7-dihydroxynaphthalene is preferred. Alternatively, when the moisture resistance of the cured product is important, compounds containing an alicyclic structure are preferred.

[0115] Regarding the reaction ratio of the diglycidyl ether (a1) of the aforementioned dihydroxy compound having alkylene chain and polyether chain to the aforementioned aromatic hydroxy compound (a2), from the viewpoint of reaction efficiency, it is preferable to use a (a1) / (a2) ratio of 1 / 1.01 to 1 / 5.0 (molar ratio), and more preferably a (a1) / (a2) ratio of 1 / 1.02 to 1 / 3.0 (molar ratio).

[0116] The reaction of the aforementioned diglycidyl ether (a1) of the dihydroxy compound having alkylene chain and polyether chain with the aforementioned aromatic hydroxy compound (a2) is preferably carried out in the presence of a catalyst. Various catalysts can be used as the aforementioned catalysts, 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 of DMP-30, DMAP, tetramethylammonium, tetraethylammonium, tetrabutylammonium, and benzyltributylammonium; quaternary ammonium salts of chlorides, bromides, and iodides of 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 catalysts can be used in combination. From the viewpoint of rapid reaction and high efficiency in reducing impurities, sodium hydroxide, potassium hydroxide, triphenylphosphine, and DMP-30 are preferred. The amount of these catalysts is not particularly limited, but 0.0001 to 0.1 moles are preferred relative to 1 mole of the aromatic hydroxyl group in the aforementioned aromatic hydroxyl compound (a2). The form of these catalysts is also not particularly limited; they can be used in aqueous solution or solid form.

[0117] Furthermore, the reaction between the aforementioned diglycidyl ether (a1) of the dihydroxy compound having alkylene chains and polyether chains and the aforementioned aromatic hydroxy compound (a2) can be carried out under solvent-free conditions or in the presence of an organic solvent. Examples of usable organic solvents include methyl cellosolve, ethyl cellosolve, toluene, xylene, methyl isobutyl ketone, dimethyl sulfoxide, propanol, and butanol. The amount of organic solvent used is typically 50–300% by mass, preferably 100–250% by mass, relative to the total mass of the input raw materials. These organic solvents can be used alone or in combination. For rapid reaction, solvent-free conditions are preferred; however, from the viewpoint of reducing impurities in the final product, dimethyl sulfoxide is preferred.

[0118] The reaction temperature for carrying out the aforementioned reaction is typically 50–180°C, and the reaction time is typically 1–30 hours. From the viewpoint of reducing impurities in the final product, the reaction temperature is preferably 100–160°C. Furthermore, if the resulting compound exhibits significant coloration, antioxidants or reducing agents can be added to suppress this. Antioxidants are not particularly limited, and examples include hindered phenolic compounds such as 2,6-dialkylphenol derivatives, divalent sulfur compounds, and phosphite compounds containing trivalent phosphorus atoms. Reducing agents are not particularly limited, and examples include hypophosphorous acid, phosphorous acid, thiosulfate, sulfurous acid, bisulfite, or their salts.

[0119] After the aforementioned reaction is completed, neutralization or washing may be performed until the pH of the reaction mixture reaches 3-7, preferably 5-7. Neutralization and washing can be carried out using conventional methods. For example, when using a basic catalyst, 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, if necessary, the product can be concentrated by distilling off the solvent under reduced pressure and heating to obtain the hydroxyl compound.

[0120] By combining the aforementioned glycidyl ether having an alkylene chain with a glycidyl ether having a polyether chain, it is possible to obtain a hydroxyl compound having both the aforementioned structural unit X and the aforementioned structural unit Y. As a preferred structure at this time, compounds with the following structural formulas can be listed as examples.

[0121]

[0122]

[0123]

[0124] In the above structural formulas, ran represents random bonding; R' is a divalent hydrocarbon group with 2 to 12 carbon atoms; n1 is an integer from 4 to 16; n2 is 2 to 30 based on the average value of the repeating units; m1 and m2 are the average values ​​of the repeating units, each independently ranging from 0.5 to 25. The repeating units present in the repeating units can be chosen to be the same or different from each other.

[0125] Furthermore, by using the aforementioned glycidyl ether having an alkylene chain as a raw material, it is possible to obtain a hydroxyl compound having the aforementioned structural unit X. As a preferred structure at this time, examples can be given, such as the compound shown in the following structural formula.

[0126]

[0127]

[0128]

[0129] In the above structural formulas, n1 is an integer from 4 to 16, and m1 is the average value of the repeated values, which is from 0.5 to 25.

[0130] Furthermore, by using glycidyl ether having the aforementioned polyether chain as a raw material, it is possible to obtain a hydroxyl compound having the aforementioned structural unit Y. As a preferred structure at this time, compounds with the following structural formulas can be listed as examples.

[0131]

[0132]

[0133]

[0134] In the above structural formulas, R' is a divalent hydrocarbon group with 2 to 12 carbon atoms; n2 is 2 to 30 based on the average value of the repeating units; and m2 is 0.5 to 25 based on the average value of the repeating units. The repeating units may be identical or different from each other.

[0135] In the aforementioned method for manufacturing epoxy resin (A), the method for the glycidyl etherification reaction of the precursor (intermediate) hydroxyl compound obtained through the above process is not particularly limited, and examples include: a method of reacting phenolic hydroxyl groups with epihaloalcohols; and a method of olefinizing phenolic hydroxyl groups by oxidizing the carbon-carbon double bond of the olefin with an oxidizing agent. Among these, from the viewpoint of easy access to raw materials and reaction, the method using epihaloalcohols (a3) ​​is preferred.

[0136] As a method for using epihaloalcohol (a3), one example is the following: 0.3 to 100 moles of epihaloalcohol (a3) ​​are added relative to 1 mole of the aromatic hydroxyl group of the hydroxyl compound obtained above, while simultaneously or slowly adding a basic catalyst of 0.9 to 2.0 moles relative to 1 mole of the aromatic hydroxyl group of the hydroxyl compound to the mixture, and the reaction is carried out at a temperature of 20 to 120°C for 0.5 to 10 hours. Regarding the amount of epihaloalcohol (a3) ​​added, the greater the excess of epihaloalcohol (a3), the closer the resulting epoxy resin is to the theoretical structure, and the formation of secondary hydroxyl groups that occur through the reaction of unreacted aromatic hydroxyl groups with epoxy groups can be suppressed. From this viewpoint, a range of 2.5 to 100 equivalents is preferred. The alkaline catalyst can be in solid form or in aqueous solution. In the case of aqueous solution, the following method can be used: while continuously adding the catalyst, water and epihaloalcohol (a3) ​​are continuously distilled from the reaction mixture under reduced pressure or normal pressure, water is further removed by separation, and epihaloalcohol (a3) ​​is continuously returned to the reaction mixture.

[0137] It should be noted that, in industrial production, it is preferable that, in the first batch of epoxy resin production, all epihaloalcohols (a3) ​​used are virgin, but in subsequent batches and thereafter, epihaloalcohols (a3) ​​recovered from the crude reaction product and virgin epihaloalcohols (a3) ​​equivalent to the amount consumed and lost in the reaction are used in combination. In this case, the epihaloalcohol (a3) ​​used is not particularly limited, and examples include epichlorohydrin and epibromohydrin. Epichlorohydrin is preferred from the perspective of easy availability.

[0138] Furthermore, there are no particular limitations on the alkaline catalyst, and examples include alkaline earth metal hydroxides, alkali metal carbonates, and alkali metal hydroxides. From the viewpoint of excellent catalytic activity in epoxy resin synthesis reactions, alkali metal hydroxides are preferred, such as sodium hydroxide and potassium hydroxide. These alkali metal hydroxides can be used in aqueous solutions of approximately 10–55% by mass, or in solid form.

[0139] Furthermore, by using a combination of organic solvents, the reaction rate in the synthesis of epoxy resins can be increased. There are no particular limitations on such organic solvents; examples include ketones such as acetone and methyl ethyl ketone; alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, sec-butanol, and tert-butanol; cellosols such as methyl cellosol and ethyl cellosol; 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 can be used individually, or, to adjust polarity, two or more can be used in combination.

[0140] After washing the reactants from these glycidylation reactions with water, unreacted epihaloalcohols (a3) ​​and the combined organic solvents are distilled off under heating and reduced pressure. Alternatively, to further prepare epoxy resins with low hydrolytic halogen content, the resulting epoxy resin can be redissolved in organic solvents such as toluene, methyl isobutyl ketone, or methyl ethyl ketone, and an aqueous solution of alkali metal hydroxides such as sodium hydroxide or potassium hydroxide can be added for further reaction. In this case, phase transfer catalysts such as quaternary ammonium salts or crown ethers may be present to increase the reaction rate.

[0141] The amount of phase transfer catalyst used is preferably in the range of 0.1 to 3.0% by mass relative to the epoxy resin used. After the reaction is completed, the generated salt is removed by filtration, washing with water, etc., and then solvents such as toluene and methyl isobutyl ketone are distilled off under heating and reduced pressure to obtain a high-purity epoxy resin.

[0142] In this invention, from the viewpoint of further imparting flexibility and easily exhibiting disintegration properties using the thermally expandable particles (C) described later, the cured product preferably exhibits a phase-separated structure. From this viewpoint, it is characterized by the use of an epoxy resin (B) with an epoxy equivalent of 100 to 300 g / eq in combination with the aforementioned epoxy resin (A).

[0143] As for the aforementioned epoxy resin (B), any epoxy equivalent in the range of 100–300 g / eq is acceptable, and its structure is not limited. Examples include liquid epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AD ​​type epoxy resin, polyhydroxybenzene type epoxy resin, polyhydroxynaphthalene type epoxy resin, biphenyl type epoxy resin, and tetramethylbiphenyl type epoxy resin; brominated epoxy resins such as brominated phenolic varnish type epoxy resin; and solid epoxy resins such as bisphenol A type epoxy resin, phenolic varnish type epoxy resin, cresolic phenolic varnish type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, and dicyclopentadiene-benzene type epoxy resin. Phenolic addition reaction epoxy resins, phenol aralkyl epoxy resins, phenyl ether epoxy resins, naphthyl ether epoxy resins, naphthol phenolic varnish epoxy resins, naphthol aralkyl epoxy resins, naphthol-phenol cocondensed phenolic varnish epoxy resins, naphthol-cresol cocondensed phenolic varnish epoxy resins, aromatic hydrocarbon formaldehyde resin modified phenolic resin epoxy resins, biphenyl modified phenolic varnish epoxy resins, etc., can be used alone or in combination of two or more types. It is preferable to select the appropriate type based on the target application and the physical properties of the cured product.

[0144] Among these, epoxy resins with an epoxy equivalent of 100–300 g / eq are preferred, including 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. Epoxy resins with an epoxy equivalent of 100–300 g / eq are particularly preferred.

[0145] In this invention, the ratio of epoxy resin (A) to epoxy resin (B) is not particularly limited. From the viewpoint that phase separation easily occurs in the cured product, the mass ratio (A):(B) of epoxy resin (A):(B) is 97:3 to 3:97, preferably 10:90 to 90:10, and particularly preferably 80:20 to 20:80. By causing phase separation in the cured product, an island-like structure is formed, which balances the adhesion and stress relaxation ability of the cured product, exhibits high adhesion over a particularly wide temperature range, and has the effect of reducing the molding shrinkage rate of the resin composition before and after heat curing.

[0146] The thermally expandable particles (C) used in this invention can be particles formed from inorganic materials or particles formed from organic materials. Examples of inorganic materials include, for instance, thermally expandable graphite as disclosed in Japanese Patent Application Publication No. 2000-44219. Examples of particles formed from organic materials include particles that use a thermoplastic polymer as a shell and microencapsulate a volatile expanding agent that is gaseous at temperatures below its softening point to form thermally expandable microcapsules.

[0147] Among these, from the viewpoint of excellent uniform dispersion when preparing epoxy resin compositions, thermally expandable microcapsules formed of organic materials are preferred.

[0148] Methods for manufacturing the aforementioned thermally expandable microcapsules have been previously provided in Japanese Patent Publication No. 42-26524, and from the viewpoint of causing the epoxy resin in this invention to undergo thermosetting, heat resistance is preferred. Methods for manufacturing heat-resistant thermally expandable microcapsules have been provided, for example, in WO99 / 46320, WO99 / 43758, and Japanese Patent Application Publication No. 2002-226620.

[0149] That is, from the viewpoint that particles that do not thermally expand during the thermosetting of epoxy resin but maintain their original particle shape and thermally expand at high temperatures due to heat energy after use are preferred, thermally expandable microcapsules made of a polymer as the outer shell polymer are preferred, wherein the polymer is formed by polymerizing nitrile monomers and monomers having carboxyl groups as essential components.

[0150] To further impart heat resistance, it is also preferable to use monomers with amide groups or monomers with cyclic structures in the side chains.

[0151] As a method for obtaining the aforementioned heat-resistant, thermally expandable microcapsules, for example, the outer shell polymer is adjusted by appropriately blending a polymerization initiator into the above-mentioned components. Known polymerization initiators such as peroxides and azo compounds can be used. Examples include azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, diisopropyl peroxide dicarbonate, tert-butyl peroxide, and 2,2'-azobis(2,4-dimethylpentanonitrile). Oil-soluble polymerization initiators that are soluble in the polymerizable monomers used are suitable. The glass transition temperature (Tg) of the polymer constituting the outer shell of the thermally expandable microcapsule is preferably 120°C or higher. The Tg of the polymer can be calculated based on the Tg of each homopolymer constituting the monomer. Alternatively, it can be measured using differential scanning calorimetry (DSC) or the like.

[0152] The foaming agent contained within the microcapsules is a gaseous substance that exists below the softening point of the outer polymer shell, and can be a known substance. 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, halides of methane, and tetraalkylsilanes; and compounds such as AIBN that undergo thermal decomposition upon heating and become gaseous. The appropriate foaming agent is selected based on the desired temperature range for capsule foaming. The above-mentioned foaming agents can be used alone or in combination of two or more.

[0153] In addition, examples include fluorinated compounds such as HCF, HCFC, HFC, and HFE; commonly known as Freon, fluorocarbon, and fluoroether. However, due to concerns about ozone layer depletion and global warming, their use is best avoided in today's society. In actual production, conventional methods for manufacturing thermally expandable microcapsules are typically used. That is, inorganic particles such as silica, magnesium hydroxide, calcium phosphate, and aluminum hydroxide can be used as dispersion stabilizers in aqueous systems. Furthermore, dispersion stabilizing aids can be used, such as the condensation product of diethanolamine and aliphatic dicarboxylic acids, polyvinylpyrrolidone, methylcellulose, polyethylene oxide, polyvinyl alcohol, and various emulsifiers.

[0154] The average particle size of the aforementioned thermally expandable particles (C) is 1 to 500 μm, preferably 3 to 100 μm, and more preferably 5 to 50 μm.

[0155] The aforementioned thermally expandable particles (C) can be directly mixed with the aforementioned epoxy resin (A) and epoxy resin (B), or a masterbatch made by dispersing the thermally expandable particles (C) in various resins at a high concentration can be used and mixed with the aforementioned epoxy resin (A) and epoxy resin (B).

[0156] Commercially available products can also be used as such thermally expanding particles (C). Examples of commercially available products include microspheres manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd. (trade 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 manufactured by KUREHA Co., Ltd. (trade names: H850D, H880D, S2340D, S2640D); and thermally expanding graphite manufactured by AIR WATER Co., Ltd. (trade names: 50LTE-U, MZ-260, CA-60, SS-3, SS-3LA). Particles that do not thermally expand at the curing temperature of the epoxy resin composition but thermally expand at the heating temperature during disintegration are preferably selected.

[0157] From the viewpoint that the use ratio of the aforementioned thermally expandable particles (C) should be such that it exhibits sufficient expansion upon disintegration after use, thereby reducing adhesion, without impairing the adhesion or the softness of the cured epoxy resin composition of the present invention, it is preferable to use a range of 3 to 40 parts by weight relative to a total of 100 parts by weight of the aforementioned epoxy resin (A) and the aforementioned epoxy resin (B), and particularly preferably a range of 5 to 30 parts by weight.

[0158] The epoxy resin composition of the present invention preferably further comprises a curing agent (D) capable of reacting with a conventional epoxy resin.

[0159] The curing agent (D) mentioned above is not particularly limited, and examples include amine compounds, acid anhydrides, amide compounds, compounds containing phenolic hydroxyl groups, carboxylic acid compounds, and hydroxyl compounds, which are precursors of the aforementioned epoxy resin (A).

[0160] Examples of the aforementioned amine compounds include, for instance, trimethylenediamine, ethylenediamine, N,N,N',N'-tetramethylethylenediamine, pentamethyldiethylenetriamine, triethylenediamine, diallyldiamine, N,N,N',N'-tetramethylpropenyldiamine, tetramethylenediamine, pentanediamine, hexamethylenediamine, trimethylhexamethylenediamine, N,N,N',N'-tetramethylhexamethylenediamine, N,N-dimethylcyclohexylamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, dimethylaminopropylamine, diethylaminopropylamine, dibutylaminopropylamine, 1,4-diazabicyclo(2,2,2)octane (triethylenediamine), polyoxyethylenediamine, polyoxypropylenediamine, bis(2-dimethylaminoethyl) ether, dimethylaminoethoxyethoxyethanol, triethanolamine, and dimethylaminohexanol, among other aliphatic amine compounds.

[0161] Piperidine, piperazine, montanine diamine, isophorone diamine, methylmorpholine, ethylmorpholine, N,N',N”-tris(dimethylaminopropyl)hexahydro-triazine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxazolo(5,5)undecane adduct, N-aminoethylpiperazine, trimethylaminoethylpiperazine, bis(4-aminocyclohexyl)methane, N,N'-dimethylpiperazine, 1,8-diazabicyclo-[5.4.0]-undecene (DBU) and other alicyclic and heterocyclic amine compounds;

[0162] Aromatic amine compounds such as o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, diaminodiphenylmethane, diaminodiphenyl sulfone, benzylmethylamine, dimethylbenzylamine, m-phenylenediamine, pyridine, methylpyridine, α-methylbenzylmethylamine, etc.

[0163] Modified amine compounds include epoxy addition polyamines, Michael addition polyamines, Mannich addition polyamines, thiourea addition polyamines, ketone-terminated polyamines, dicyandiamide, guanidine, organic acid hydrazides, diaminomaleonitrile, aminoimides, boron trifluoride-piperidine complexes, boron trifluoride-monoethylamine complexes, and other modified amine compounds.

[0164] Examples of the aforementioned acid anhydrides include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, maleic anhydride polypropylene glycol, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride.

[0165] Examples of compounds containing phenolic hydroxyl groups include bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, and bis(4-hydroxyphenyl)sulfone, among other bisphenols; phenolic varnish resins, cresol varnish resins, aromatic hydrocarbon formaldehyde resins modified with phenolic resins, dicyclopentadiene phenol addition-type resins, phenol aralkyl resins (neophenolic resins), naphthol aralkyl resins, trimethylolpropane resins, and tetrahydroxyphenyl... Ethane resin, naphthol phenolic varnish resin, naphthol-phenol co-condensed phenolic varnish resin, naphthol-cresol co-condensed phenolic varnish resin, biphenyl-modified phenolic resin (a polyphenol compound obtained by linking a phenol core with a dimethylene group), biphenyl-modified naphthol resin (a polyphenol compound obtained by linking a phenol core with a dimethylene group), aminotriazine-modified phenolic resin (a polyphenol compound obtained by linking a phenol core with melamine, benzoguanamine, etc.), and alkoxy-containing aromatic ring-modified phenolic varnish resin (a polyphenol compound obtained by linking a phenol core and an alkoxy-containing aromatic ring with formaldehyde), etc., are all polyphenol compounds.

[0166] Examples of the aforementioned amide compounds include dicyandiamide and polyamide amines. Examples of polyamide amines include substances obtained by reacting aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, and azelaic acid, fatty acids, dimer acids, and other carboxylic acid compounds with aliphatic polyamines or polyamines having polyoxyalkylene chains.

[0167] Examples of the aforementioned carboxylic acid compounds include carboxylic acid-terminated polyesters, polyacrylic acid, maleic acid-modified polypropylene glycol, and other carboxylic acid polymers.

[0168] When using these curing agents, only one type of curing agent can be used, or two or more types can be mixed. Furthermore, in applications such as underfill materials and general coatings, the aforementioned amine compounds, carboxylic acid compounds, and / or anhydride compounds are preferred. Additionally, in applications such as adhesives and flexible wiring substrates, from the viewpoints of workability, curing properties, and long-term stability, amine compounds are preferred, and dicyandiamide is particularly preferred. Furthermore, in applications such as semiconductor sealing materials, from the viewpoint of the heat resistance of the cured product, solid-state phenolic compounds are preferred.

[0169] Furthermore, the epoxy resin composition of the present invention may contain a curing accelerator. Various substances can be used as the aforementioned curing accelerator, including, for example, urea compounds, phosphorus compounds, tertiary amines, imidazoles, imidazolines, organic acid metal salts, Lewis acids, amine complex salts, etc. When used as an adhesive, from the viewpoint of excellent workability and low-temperature curing properties, urea compounds are preferred, and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) is particularly preferred. When used as a semiconductor sealing material, from the viewpoint of excellent curability, heat resistance, electrical properties, and moisture resistance reliability, triphenylphosphine is preferred among phosphorus compounds, and 1,8-diazabicyclo-[5.4.0]-undecene is preferred among tertiary amines.

[0170] Examples of the aforementioned phosphorus compounds include, for instance, 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.

[0171] Examples of imidazoles mentioned above include, for instance, imidazole, 1-methylimidazolium, 2-methylimidazolium, 3-methylimidazolium, 4-methylimidazolium, 5-methylimidazolium, 1-ethylimidazolium, 2-ethylimidazolium, 3-ethylimidazolium, 4-ethylimidazolium, 5-ethylimidazolium, 1-n-propylimidazolium, 2-n-propylimidazolium, 1-isopropylimidazolium, 2-isopropylimidazolium, 1-n-butylimidazolium, 2-n-butylimidazolium, 1-isobutylimidazolium, 2-isobutylimidazolium, 2-undecyl-1H-imidazolium, 2-heptadecanyl-1H-imidazolium, 1,2-dimethylimidazolium, 1,3-dimethylimidazolium, 2,4-dimethylimidazolium, 2-ethyl-4-methylimidazolium, 1-phenylimidazolium, 2-phenyl-1H-imidazolium, 4-methyl-2 -Phenylacetyl-1H-imidazolium, 2-Phenylacetyl-4-methylimidazolium, 1-benzyl-2-methylimidazolium, 1-benzyl-2-phenylimidazolium, 1-cyanoethyl-2-methylimidazolium, 1-cyanoethyl-2-ethyl-4-methylimidazolium, 1-cyanoethyl-2-undecylimidazolium, 1-cyanoethyl-2-phenylimidazolium, 2-phenylimidazolium isocyanuric acid adduct, 2-methylimidazolium isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazolium, 2-phenyl-4-methyl-5-hydroxymethylimidazolium, 1-cyanoethyl-2-phenyl-4,5-di(2-cyanoethoxy)methylimidazolium, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 1-benzyl-2-phenylimidazolium hydrochloride, etc.

[0172] Examples of the aforementioned imidazophosphorus compounds include 2-methylimidazoline and 2-phenylimidazoline.

[0173] Examples of the aforementioned urea compounds include, for example, 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.

[0174] In the epoxy resin composition of the present invention, in addition to the aforementioned epoxy resin (A) and epoxy resin (B), other epoxy resins may be used in combination without impairing the effects of the present invention. In this case, the total amount of epoxy resin (A) and epoxy resin (B) in the epoxy resin composition of the present invention is preferably 30% by mass or more, particularly preferably 40% by mass or more of all epoxy resins.

[0175] As epoxy resins that can be used in combination, there are no limitations except that they do not belong to epoxy resin (A) or epoxy resin (B). Examples include liquid epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AD ​​type epoxy resin, polyhydroxybenzene type epoxy resin, polyhydroxynaphthalene type epoxy resin, biphenyl type epoxy resin, and tetramethylbiphenyl type epoxy resin; brominated epoxy resins such as brominated phenolic varnish type epoxy resin; solid bisphenol A type epoxy resin, phenolic varnish type epoxy resin, cresol phenolic varnish type epoxy resin, and triphenylmethane type epoxy resin. Resins, including tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, phenyl ether type epoxy resin, naphthol ether type epoxy resin, naphthol phenolic varnish type epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol cocondensed phenolic varnish type epoxy resin, naphthol-cresol cocondensed phenolic varnish type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenolic resin type epoxy resin, biphenyl modified phenolic varnish type epoxy resin, etc., can be used alone or in combination of two or more types. It is preferred to select the appropriate type based on the target application and the physical properties of the cured product.

[0176] The amount of epoxy resin and curing agent used in the epoxy resin composition of the present invention is not particularly limited. From the viewpoint of good mechanical properties of the obtained cured product, it is preferable that the amount of active groups in the curing agent is 0.4 to 1.5 equivalents relative to the total amount of epoxy groups in the epoxy resin composition.

[0177] The epoxy resin composition of the present invention may further contain fillers that are not part of the aforementioned thermally expandable particles (C). Examples of fillers include inorganic fillers and organic fillers. Examples of inorganic fillers include, for instance, inorganic microparticles.

[0178] As inorganic microparticles, examples include those with excellent heat resistance such as alumina, magnesium oxide, titanium dioxide, zirconium oxide, and silica (quartz, fumed silica, precipitated silica, anhydrous silica, fused silica, crystalline silica, and ultrafine amorphous silica); those with excellent thermal conductivity such as boron nitride, aluminum nitride, alumina, titanium oxide, magnesium oxide, zinc oxide, silica, and diamond; those with excellent electrical conductivity such as metal fillers and / or metal-coated fillers made from elemental metals or alloys (e.g., iron, copper, magnesium, aluminum, gold, silver, platinum, zinc, manganese, and stainless steel); and those with excellent barrier properties such as mica, clay, kaolin, talc, zeolite, wollastonite, montmorillonite, potassium titanate, magnesium sulfate, and seaweed. Microparticles with high refractive index include: siliceous stone, vermiculite, aluminum borate, calcium carbonate, titanium dioxide, barium sulfate, zinc oxide, and magnesium hydroxide. Other examples include barium titanate, zirconium oxide, and titanium dioxide. Microparticles 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 their compounds and oxides. Microparticles with excellent wear resistance include metals such as silicon dioxide, aluminum oxide, zirconium oxide, and magnesium oxide, as well as their compounds and oxides. Microparticles with excellent electrical conductivity include metals such as silver and copper, tin oxide, and indium oxide. Microparticles with excellent insulation properties include silicon dioxide. Microparticles with excellent ultraviolet radiation blocking properties include titanium dioxide and zinc oxide. These inorganic microparticles can be selected appropriately according to the application and can be used individually or in combination. In addition to the properties listed in the examples, the aforementioned inorganic particles also possess various other properties. Therefore, they can be selected appropriately based on their intended use.

[0179] For example, when using silica as inorganic microparticles, there are no particular limitations; known silica microparticles such as powdered silica and colloidal silica can be used. Examples of commercially available powdered silica microparticles include AEROSIL50 and 200 manufactured by AEROSIL Corporation of Japan; Sildex H31, H32, H51, H52, H121, and H122 manufactured by Asahi Glass Co., Ltd.; E220A and E220 manufactured by Nippon Silica Industrial Co., Ltd.; SYLYSIA470 manufactured by Fuji-Silysia Co., Ltd.; and SG flake manufactured by Nippon Sheet Glass Co., Ltd.

[0180] In addition, commercially available colloidal silica products include, for example, methanol 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 manufactured by Nissan Chemical Industries Co., Ltd.

[0181] Surface-modified silica microparticles can be used, such as those obtained by surface-treating the aforementioned silica microparticles with a reactive silane coupling agent having a hydrophobic group; and those obtained by modifying with a compound having a (meth)acrylyl group. Commercially available powdered silica modified with a compound having a (meth)acrylyl group includes AEROSIL RM50 and R711 manufactured by AEROSIL Corporation of Japan, and commercially available colloidal silica modified with a compound having a (meth)acrylyl group includes MIBK-SD manufactured by Nissan Chemical Industries, Ltd.

[0182] The shape of the aforementioned silica particles is not particularly limited, and spherical, hollow, porous, rod-shaped, plate-shaped, fibrous, or irregularly shaped particles can be used. In addition, the primary particle size is preferably in the range of 5 to 200 nm.

[0183] As titanium dioxide microparticles, not only extender pigments can be used, but also ultraviolet light-responsive photocatalysts, such as anatase titanium dioxide, rutile titanium dioxide, and brookite titanium dioxide. Furthermore, particles designed to respond to visible light can also be used by doping the crystal structure of titanium dioxide with foreign elements. Suitable doping elements for 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, they can be powders, sols or slurries obtained by dispersing in organic solvents or water. Examples of commercially available powdered titanium dioxide microparticles include AEROSIL P-25 manufactured by AEROSIL Corporation of Japan and ATM-100 manufactured by TAYCA Corporation. Examples of commercially available slurry-type titanium dioxide microparticles include TKD-701 manufactured by TAYCA Corporation.

[0184] The epoxy resin composition of the present invention may further contain a fibrous matrix. The aforementioned fibrous matrix is ​​not particularly limited, but is preferably a fibrous matrix used in fiber-reinforced resins, including inorganic fibers and organic fibers.

[0185] In addition to inorganic fibers such as carbon fiber, glass fiber, boron fiber, alumina fiber, and silicon carbide fiber, other inorganic fibers include carbon fiber, activated carbon fiber, graphite fiber, tungsten carbide fiber, silicon carbide fiber, ceramic fiber, natural fiber, and basalt mineral fiber; boron nitride fiber, boron carbide fiber, and metal fiber. Among the aforementioned metal fibers, examples include aluminum fiber, copper fiber, brass fiber, stainless steel fiber, and steel fiber.

[0186] Organic fibers can include synthetic fibers made from resins such as polybenzodioxazole, aromatic polyamide, PBO (poly(p-phenylenebenzoxazole)), polyphenylene sulfide, polyester, acrylics, 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.

[0187] Carbon fiber and glass fiber are preferred due to their wide range of industrial applications. Only one type can be used, or multiple types can be used simultaneously.

[0188] The aforementioned fibrous matrix can be an aggregate of fibers, which can be continuous or discontinuous, woven or nonwoven. Alternatively, it can be a fiber bundle formed by arranging fibers in one direction, or a sheet formed by arranging fiber bundles side-by-side. Furthermore, it can be a three-dimensional shape that gives the fiber aggregate thickness.

[0189] In the epoxy resin composition of the present invention, a dispersion medium can be used for the purpose of adjusting the amount of solid components and viscosity of the resin composition. As a dispersion medium, any liquid medium that does not impair the effects of the present invention is acceptable; various organic solvents, liquid organic polymers, etc., are examples.

[0190] Examples of organic solvents mentioned above 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 solvents can be used alone or in combination. Among them, methyl ethyl ketone is preferred from the perspective of volatility and solvent recovery during coating.

[0191] The aforementioned liquid organic polymers refer to liquid organic polymers that do not directly participate in the curing reaction. Examples include, for instance, polymer modifiers containing carboxyl groups (FLOWLEN G-900, NC-500: Kyoeisha), acrylic polymers (FLOWLEN WK-20: Kyoeisha), amine salts of special modified phosphate esters (HIPLAAD ED-251: Kusunoki Kasei), and modified acrylic block copolymers (DISPERBYK2000: BYK-Chemie).

[0192] Furthermore, the resin composition of the present invention may contain resins other than the various compounds described above. As the resin, any conventionally known resin can be used as long as it does not impair the effects of the present invention; for example, thermosetting resins and thermoplastic resins can be used.

[0193] Thermosetting resins are resins that, when cured by heating, radiation, catalysts, or other means, are substantially insoluble and can become infusible. Specific examples include phenolic resins, urea resins, melamine resins, benzoguanamine resins, alkyd resins, unsaturated polyester resins, vinyl ester resins, diallyl terephthalate resins, silicone resins, urethane resins, furan resins, ketone resins, xylene resins, thermosetting polyimide resins, benzoxazine resins, reactive ester resins, aniline resins, cyanate ester resins, styrene-maleic anhydride (SMA) resins, and maleimide resins. These thermosetting resins can be used alone or in combination of two or more.

[0194] Thermoplastic resins are resins that can be melted and 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 resins, polyvinyl chloride resin, polyvinylidene chloride resin, polyethylene terephthalate resin, ethylene vinyl alcohol resin, cellulose acetate resin, ionomer resins, 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, polyaryl ester resin, thermoplastic polyimide resin, polyamide-imide resin, polyetheretherketone resin, polyketone resin, liquid crystal polyester resin, fluoropolymer resin, syndiotactic polystyrene resin, and cyclic polyolefin resin, etc. These thermoplastic resins can be used in one or in combination of two or more.

[0195] The resin composition of the present invention may contain other compounding agents. Examples include, for instance, catalysts, polymerization initiators, inorganic pigments, organic pigments, extender pigments, clay minerals, waxes, surfactants, stabilizers, flow modifiers, coupling agents, dyes, leveling agents, rheology control agents, ultraviolet absorbers, antioxidants, flame retardants, plasticizers, reactive diluents, etc.

[0196] By curing the resin composition of the present invention, a cured product can be obtained. Curing can be performed at room temperature or by heating. In the case of heat curing, curing can be achieved by a single heating step or by using a multi-stage heating process.

[0197] Furthermore, the epoxy resin composition of the present invention can also be cured by active energy rays. In this case, a photocationic polymerization initiator can be used as the polymerization initiator. Visible light, ultraviolet light, X-rays, electron beams, etc., can be used as the active energy rays.

[0198] Examples of photocationic polymerization initiators include aryl-sulfonium salts and aryl-iodonium salts. Specifically, arylsulfonium hexafluorophosphate, arylsulfonium hexafluoroantimonate, arylsulfonium tetra(pentafluoro)borate, and tri(alkylphenyl)sulfonium hexafluorophosphate can be used. Photocationic polymerization initiators can be used alone or in combination of two or more.

[0199] The epoxy resin composition of the present invention can be prepared simply by uniformly mixing the aforementioned components, and the method is not particularly limited. It can be prepared by uniformly mixing, for example, using a pot mill, ball mill, bead mill, roller mill, homogenizer, supermill, homogenizer distributor, universal mixer, Banbury mixer, kneader, etc.

[0200] The cured product of the present invention is obtained by curing the aforementioned epoxy resin composition, and various curing conditions can be selected depending on the type of curing agent, curing accelerator, etc. These curing conditions are the same as those for known epoxy resin compositions, and no special method is required. The resulting cured product can be laminated with a substrate to form a laminate. As the substrate for the laminate, inorganic materials such as metal and glass, organic materials such as plastics and wood, etc., can be used appropriately according to the application. It can be shaped into a laminate, and can have a flat, sheet-like, or three-dimensional structure, or even a three-dimensional shape. It can be any shape that conforms to the target, such as a shape with curvature on the entire surface or in parts. Furthermore, the hardness, thickness, etc., of the substrate are not limited. Additionally, the cured product of the present invention can be used as a substrate to further laminate the cured product of the present invention.

[0201] Alternatively, a multilayer laminate can be formed by laminating a first substrate, a layer formed from a cured resin composition, and a second substrate in that order. The resin composition of the present invention exhibits excellent adhesive properties and is therefore suitable for use as an adhesive for bonding the first substrate to the second substrate.

[0202] The resin composition of the present invention exhibits particularly high adhesion to metals and / or metal oxides, and therefore can be used particularly well as a primer for metals. Examples of metals include copper, aluminum, gold, silver, iron, platinum, chromium, nickel, tin, titanium, zinc, various alloys, and materials obtained by combining them. Examples of metal oxides include individual oxides and / or composite oxides of these metals. In particular, it exhibits excellent adhesion to iron, copper, and aluminum, and therefore can be used well as an adhesive for iron, copper, and aluminum.

[0203] Furthermore, the resin composition of the present invention is capable of relaxing stress, and therefore is particularly preferably used for bonding different types of raw materials. For example, even in laminates of different raw materials, such as a first substrate being a metal or metal oxide and a second substrate being a plastic layer, the adhesive strength can be maintained due to the stress relaxation capability of the resin composition.

[0204] In the laminate of the present invention, the layer formed by the cured material can be formed by directly coating and molding the substrate, or by stacking pre-formed layers. In the case of direct coating, the coating method is not particularly limited, and examples include spraying, spin coating, dip coating, roller coating, blade coating, squeegee coating, sheet coating, slot coating, screen printing, and inkjet coating. In the case of direct molding, examples include in-mold molding, insertion molding, vacuum molding, extrusion lamination molding, and pressure molding.

[0205] In the case of laminating a pre-formed resin composition, it is possible to laminate an uncured or semi-cured resin composition layer and then cure it, or to laminate a layer formed by curing the composition to the substrate.

[0206] Alternatively, the substrate-forming precursor of the present invention can be coated onto the cured product of the present invention and then cured. Alternatively, the substrate-forming precursor or the composition of the present invention can be bonded in an uncured or semi-cured state and then cured. There are no particular limitations on the substrate-forming precursor; various curable resin compositions are also included.

[0207] The resin composition of the present invention has a fibrous matrix, and when the fibrous matrix is ​​a reinforcing fiber, the composition containing the fibrous matrix can be used as a fiber-reinforced resin.

[0208] The method of making the composition contain a fibrous matrix is ​​not particularly limited as long as it does not impair the effect of the present invention. Examples include compounding the fibrous matrix with the composition by means of mixing, coating, impregnation, injection, pressing, etc. The appropriate method can be selected according to the morphology of the fiber and the purpose of the fiber-reinforced resin.

[0209] There are no particular limitations on the method for molding the fiber-reinforced resin of the present invention. If manufacturing sheet-like products, extrusion molding is generally used, but planar pressing can also be employed. Other methods include extrusion molding, blow molding, compression molding, vacuum forming, and injection molding. If manufacturing film-like products, in addition to melt extrusion, solution casting can also be used. When using melt molding, examples include blown film forming, casting, extrusion lamination, calendering, sheet forming, fiber forming, blow molding, injection molding, rotational molding, and overmolding. Furthermore, in the case of resins that are cured by active energy rays, various curing methods using active energy rays can be employed to produce cured products. Especially when thermosetting resin is used as the main component of the base resin, molding methods such as making the molding material into a prepreg and then pressing and heating it in a pressure vessel or autoclave can be listed. In addition, RTM (Resin Transfer Molding), VaRTM (Vacuum Assist Resin Transfer Molding), lamination molding, and hand lay-up molding can also be listed.

[0210] The fiber-reinforced resin of the present invention can be formed into a state referred to as uncured or semi-cured prepreg. After the article is circulated in the state of prepreg, final curing can be performed to form a cured product. In the case of forming a laminate, it is preferable to form a laminate with tightly bonded layers by forming the prepreg and then performing final curing.

[0211] There is no particular limitation on the mass ratio of the composition used at this time to the fibrous matrix, but it is generally preferred to prepare it in such a way that the resin component in the prepreg is 20 to 60% by mass.

[0212] The cured resin composition of the present invention exhibits excellent adhesion to substrates, and therefore is particularly suitable for use in electronic components. It is particularly suitable as an adhesive and resist material for semiconductor sealing materials, circuit boards, multilayer films, multilayer substrates, etc. Furthermore, it is also suitable as a base resin for fiber-reinforced resins, and is particularly suitable as a prepreg with high heat resistance. The electronic components obtained in this manner are suitable for a wide variety of applications, including, but not limited to, industrial machinery parts, general machinery parts, automotive / railway / vehicle parts, aerospace-related parts, electronic / electrical parts, building materials, container / packaging components, consumer goods, sporting / leisure products, and wind power generation housing components.

[0213] This invention's adhesive, utilizing the excellent flexibility of cured materials, is suitable for use as an adhesive for structural components in the automotive, tram, civil engineering, electronics, aircraft, and aerospace industries. When used for bonding different raw materials, such as metals and non-metals, the adhesive maintains high adhesion unaffected by temperature changes and is resistant to peeling. Furthermore, in addition to its structural component applications, the adhesive can also be used for general office applications, medical applications, and for bonding carbon fibers, battery cells, modules, and housings of batteries. Examples include adhesives for bonding optical components, bonding optical devices, mounting printed circuit boards, chip bonding, semiconductor adhesives such as underfill, underfill for BGA reinforcement, and mounting adhesives for anisotropic conductive films and anisotropic conductive pastes.

[0214] The following examples illustrate this point.

[0215] 1. Semiconductor sealing materials

[0216] As a method for obtaining a semiconductor sealing material from the resin composition of the present invention, one can be described as follows: using an extruder, kneader, roller, or similar apparatus to thoroughly melt and mix the aforementioned resin composition with a curing accelerator and an inorganic filler until homogeneous. In this case, fused silica is typically used as the inorganic filler. When used as a high thermal conductivity semiconductor sealing material for power transistors and power ICs, highly filled materials such as crystalline silica, alumina, or silicon nitride, which have higher thermal conductivity than fused silica, can be used. Regarding the filling rate, it is preferable to use an inorganic filler in the range of 30 to 95% by mass relative to 100 parts by mass of the curable resin composition. More preferably, it is 70 parts by mass or more, and even more preferably 80 parts by mass or more, to improve flame retardancy, moisture resistance, resistance to weld cracking, and reduce the coefficient of linear expansion.

[0217] 2. Semiconductor devices

[0218] As a semiconductor encapsulation molding method for obtaining a semiconductor device from the curable resin composition of the present invention, an example can be given by molding the semiconductor sealing material using a injection molding machine or transfer molding machine, or an injection molding machine, and then heating it at 50 to 250°C for 2 to 10 hours.

[0219] 3. Printed Circuit Board

[0220] As a method for obtaining a printed circuit board from the composition of the present invention, an example is: laminating the above-mentioned prepreg according to conventional methods, appropriately overlapping copper foils, and heating and pressing them at 170 to 300°C for 10 minutes to 3 hours under a pressure of 1 to 10 MPa.

[0221] 4.Laminated substrate

[0222] The method for obtaining a multilayer substrate from the composition of the present invention can be exemplified by the following steps. First, a step of applying the above-mentioned composition, which is appropriately mixed with rubber, filler, etc., to a circuit board with circuits formed using a spraying method, curtain coating method, etc., and then curing it (step 1). Then, after opening holes such as through-holes as required, treating it with a roughening agent, washing its surface with hot water to form an uneven surface, and performing a metal plating process such as copper plating (step 2). This operation is repeated sequentially as desired, alternatingly layering resin insulating layers and conductor layers with a specified circuit pattern to form a multilayer substrate (step 3). It should be noted that the opening of the through-holes is performed after the outermost resin insulating layer is formed. In addition, the multilayer substrate of the present invention can also be manufactured as follows: by heating and pressing a copper foil containing resin, obtained by semi-curing the resin composition on a copper foil, at 170 to 300°C onto a wiring substrate with circuits formed, thereby forming a roughened surface, omitting the plating process, and manufacturing a multilayer substrate.

[0223] 5. Laminated thin films

[0224] As a method for obtaining a laminated film from the composition of the present invention, the above-described composition can be coated on the surface of a support film (Y) serving as a substrate, and then dried by heating or hot air blowing to form a layer (X) of the composition.

[0225] As the organic solvent used here, ketones such as acetone, methyl ethyl ketone, and cyclohexanone are preferred; acetates such as ethyl acetate, butyl acetate, cellolytic acetate, propylene glycol monomethyl ether acetate, and carbitol acetate are preferred; carbitols such as cellolytic agents and butyl carbitol are preferred; aromatic hydrocarbons such as toluene and xylene are preferred; dimethylformamide, dimethylacetamide, and N-methylpyrrolidone are preferred. In addition, it is preferred to use the non-volatile component in a proportion of 30 to 60% by mass.

[0226] The thickness of the formed layer (X) is typically set to be greater than or equal to the thickness of the conductor layer. The thickness of the conductor layer in a circuit board is typically in the range of 5 to 70 μm; therefore, the thickness of the resin composition layer is preferably 10 to 100 μm. It should be noted that the layer (X) of the above-described composition in this invention can be protected by a protective film, as described later. By protecting it with a protective film, the adhesion and damage of contaminants or the like on the surface of the resin composition layer can be prevented.

[0227] The aforementioned support film and protective film can include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; polyesters such as polyethylene terephthalate (hereinafter sometimes referred to as "PET") and polyethylene naphthalate; polycarbonate; polyimide; and metal foils such as release paper, copper foil, and aluminum foil. It should be noted that the support film and protective film can undergo roughening treatment, corona treatment, and release treatment. The thickness of the support film is not particularly limited, and it is typically used in the range of 10–150 μm, preferably in the range of 25–50 μm. Furthermore, the thickness of the protective film is preferably set to 1–40 μm.

[0228] The aforementioned support film (Y) is peeled off after being laminated onto the circuit board or after forming an insulating layer through heat curing. Peeling off the support film (Y) after heat curing the curable resin composition layer constituting the laminated film can prevent the adhesion of contaminants or the like during the curing process. In cases where peeling is performed after curing, the support film is typically pre-treated with a demolding process.

[0229] The laminated film obtained by the above operation can be used to manufacture multilayer printed circuit boards. For example, with the layers (X) protected by a protective film, after peeling them off, the layers (X) are laminated onto one or both sides of the circuit board by means of, for example, vacuum lamination, so that the layers (X) are in direct contact with the circuit board. The lamination method can be intermittent or continuous using rollers. In addition, the laminated film and the circuit board can be heated (preheated) as needed before lamination. Regarding the lamination conditions, it is preferable to set the lamination temperature to 70 to 140°C, and the lamination pressure to 1 to 11 kgf / cm². 2 (9.8×10 4 ~107.9×10 4 N / m 2 It is preferable to perform lamination under reduced pressure of air pressure below 20 mmHg (26.7 hPa).

[0230] 6. Conductive paste

[0231] As a method for obtaining a conductive paste from the composition of the present invention, one example is a method of dispersing conductive particles in the composition. Depending on the type of conductive particles used, the above-mentioned conductive paste can be formulated into a paste resin composition for circuit connection or an anisotropic conductive adhesive.

[0232] Example

[0233] Next, the present invention will be specifically described through examples and comparative examples. Hereinafter, "parts" and "%" are quality standards unless otherwise specified.

[0234] The following conditions are used to determine 1 H and 13 C-NMR, FD-MS spectroscopy, GPC.

[0235] 1 H-NMR: JEOL RESONANCE's "JNM-ECA600"

[0236] Magnetic field strength: 600MHz

[0237] Total number of times: 32

[0238] Solvent: DMSO-d6

[0239] Sample concentration: 30% by mass

[0240] 13 C-NMR: JEOL RESONANCE's "JNM-ECA600"

[0241] Magnetic field strength: 150MHz

[0242] Total number of times: 320

[0243] Solvent: DMSO-d6

[0244] Sample concentration: 30% by mass

[0245] FD-MS: JMS-T100GC AccuTOF manufactured by Nippon Electronics Co., Ltd.

[0246] Measurement range: m / z = 50.00~2000.00

[0247] Rate of change: 25.6 mA / minute

[0248] Final current value: 40mA

[0249] Cathode voltage: -10kV

[0250] GPC: HLC-8320GPC manufactured by Tosoh Corporation.

[0251] Pillars: "TSK-GEL G2000HXL" + "TSK-GEL G3000HXL" + "TSK-GELG4000HXL" manufactured by Tosoh Corporation

[0252] Detector: RI (Differential Refractometer)

[0253] Measurement conditions: 40℃

[0254] Mobile phase: Tetrahydrofuran

[0255] Flow rate: 1 ml / min

[0256] Standards: Tosoh Corporation's "PStQuick A", "PStQuick B", "PStQuick E", and "PStQuick F"

[0257] The epoxy equivalent of the synthesized epoxy resin was determined according to JIS K7236, and the epoxy equivalent (g / eq) was calculated.

[0258] As a method for calculating the number of repeating units, examples can be shown of calculations based on the results of various appropriate machine analyses such as GPC molecular weight determination, FD-MS, and NMR.

[0259] Synthesis example 1

[0260] 210 g (0.5 mol) of diglycidyl ether of 1,12-dodecanediol (manufactured by Yokkaichi Synthetic Co., Ltd.: epoxy equivalent 210 g / eq) and 119.7 g (0.53 mol) of bisphenol A (hydroxyl equivalent 114 g / eq) were added to a flask equipped with a thermometer and a stirrer. After heating to 140 °C over 30 minutes, 3.2 g of a 20% sodium hydroxide aqueous solution was added. Subsequently, the temperature was raised to 150 °C over 30 minutes, and the reaction was further carried out at 150 °C for 16 hours. Then, a neutralization amount of sodium phosphate was added to obtain 320 g of a hydroxyl compound (Ph-1). This hydroxyl compound (Ph-1) showed a peak at M+ = 771 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ph-1) with m1 = 1 and n1 = 12, thus confirming the presence of the target hydroxyl compound. The hydroxyl equivalent of the hydroxyl compound (Ph-1) calculated according to GPC is 2000 g / eq.

[0261]

[0262] Synthesis example 2

[0263] The 3.2 g of 20% sodium hydroxide aqueous solution in Synthesis Example 1 was replaced with 1.6 g of 4% sodium hydroxide aqueous solution. Otherwise, the reaction proceeded in the same manner as in Synthesis Example 1, yielding 321 g of the hydroxyl compound (Ph-2). This hydroxyl compound (Ph-2) exhibited a peak at M+=771 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ph-2) with m1=1 and n1=12. Therefore, it was confirmed to contain the hydroxyl compound as the target. The hydroxyl equivalent of this hydroxyl compound (Ph-2) calculated according to GPC was 850 g / eq.

[0264]

[0265] Synthesis example 3

[0266] The 210 g (0.5 mol) of 1,12-dodecanediol diglycidyl ether (epoxy equivalent 210 g / eq) in Synthesis Example 1 was replaced with 236 g (0.5 mol) of 1,15-pentadecanediol diglycidyl ether (epoxy equivalent 236 g / eq), and the reaction proceeded in the same manner as in Synthesis Example 1 to yield 340 g of hydroxyl compound (Ph-3). This hydroxyl compound (Ph-3) showed a peak at M+=813 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ph-3) with m1=1 and n1=15, thus confirming the presence of the target hydroxyl compound. The hydroxyl equivalent of this hydroxyl compound (Ph-3) calculated according to GPC was 2130 g / eq.

[0267]

[0268] Synthesis example 4

[0269] The 210 g (0.5 mol) of 1,12-dodecanediol diglycidyl ether (epoxy equivalent 210 g / eq) in Synthesis Example 1 was replaced with 190 g (0.5 mol) of 1,9-nonanediol diglycidyl ether (epoxy equivalent 190 g / eq), and the reaction proceeded in the same manner as in Synthesis Example 1 to yield 305 g of hydroxyl compound (Ph-4). This hydroxyl compound (Ph-4) showed a peak at M+ = 729 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ph-4) with m1 = 1 and n1 = 9, thus confirming the presence of the target hydroxyl compound. The hydroxyl equivalent of this hydroxyl compound (Ph-4) calculated according to GPC was 1900 g / eq.

[0270]

[0271] Synthesis example 5

[0272] The 210 g (0.5 mol) of 1,12-dodecanediol diglycidyl ether (epoxy equivalent of 210 g / eq) in Synthesis Example 1 was replaced with 160 g (0.5 mol) of 1,6-hexanediol diglycidyl ether (epoxy equivalent of 160 g / eq), and the reaction proceeded in the same manner as in Synthesis Example 1 to yield 270 g of hydroxyl compound (Ph-5). This hydroxyl compound (Ph-5) exhibited a peak at M+=687 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ph-5) with m1=1 and n1=6, thus confirming the presence of the target hydroxyl compound. The hydroxyl equivalent of this hydroxyl compound (Ph-5) calculated according to GPC was 1890 g / eq.

[0273]

[0274] Synthesis example 6

[0275] The 210 g (0.5 mol) of 1,12-dodecanediol diglycidyl ether (epoxy equivalent 210 g / eq) in Synthesis Example 1 was replaced with 445 g (0.5 mol) of polytetramethylene glycol diglycidyl ether (DENACOL EX-991L, manufactured by Nagase ChemteX: epoxy equivalent 445 g / eq). Otherwise, the reaction proceeded in the same manner as in Synthesis Example 1, yielding 542 g of the hydroxyl compound (Ph-6). This hydroxyl compound (Ph-6) exhibited a peak at M+ = 1380 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ph-6) with m2 = 1 and n2 = 11, thus confirming the presence of the target hydroxyl compound. The hydroxyl equivalent of this hydroxyl compound (Ph-6) calculated according to GPC was 2497 g / eq.

[0276]

[0277] Synthesis Example 7

[0278] The 210 g (0.5 mol) of 1,12-dodecanediol diglycidyl ether (epoxy equivalent 210 g / eq) in Synthesis Example 1 was replaced with 312 g (0.35 mol) of polytetramethylene glycol diglycidyl ether (DENACOL EX-991L, manufactured by Nagase ChemteX: epoxy equivalent 445 g / eq). Otherwise, the reaction proceeded in the same manner as in Synthesis Example 1, yielding 412 g of the hydroxyl compound (Ph-7). This hydroxyl compound (Ph-7) exhibited a peak at M+ = 1380 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ph-7) with m2 = 1 and n2 = 11, thus confirming the presence of the target hydroxyl compound. The hydroxyl equivalent of this hydroxyl compound (Ph-7), calculated according to GPC, was 1001 g / eq.

[0279]

[0280] Synthesis example 8

[0281] The 210 g (0.5 mol) of 1,12-dodecanediol diglycidyl ether (epoxy equivalent 210 g / eq) in Synthesis Example 1 was replaced with 481 g (0.5 mol) of polypropylene glycol diglycidyl ether (DENACOL EX-931 manufactured by Nagase ChemteX: epoxy equivalent 481 g / eq). Otherwise, the reaction proceeded in the same manner as in Synthesis Example 1, yielding 585 g of the hydroxyl compound (Ph-8). This hydroxyl compound (Ph-8) exhibited a peak at M+ = 1226 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ph-8) with m2 = 1 and n2 = 11, thus confirming the presence of the target hydroxyl compound. The hydroxyl equivalent of this hydroxyl compound (Ph-8) calculated according to GPC was 1447 g / eq.

[0282]

[0283] Synthesis example 9

[0284] The 210 g (0.5 mol) of 1,12-dodecanediol diglycidyl ether (epoxy equivalent 210 g / eq) in Synthesis Example 1 was replaced with 136 g (0.43 mol) of 1,6-hexanediol diglycidyl ether ("SR-16H" manufactured by Sakamoto Pharmaceutical Co., Ltd.: epoxy equivalent 160 g / eq) and 66 g (0.07 mol) of polytetramethylenediol diglycidyl ether ("DENACOL EX-991L" manufactured by Nagase ChemteX Co., Ltd.: epoxy equivalent 445 g / eq). Otherwise, the reaction proceeded in the same manner as in Synthesis Example 1 to obtain 320 g of hydroxyl compound (Ph-9). The hydroxyl compound (Ph-9) exhibited a peak at M+=1839 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ph-9) with n1=6, m1=1, n2=11, m2=1. Therefore, it was confirmed that it contains a hydroxyl compound as the target. The hydroxyl equivalent of the hydroxyl compound (Ph-9) calculated according to GPC is 1896 g / eq.

[0285]

[0286] Synthesis example 10

[0287] The 210 g (0.5 mol) of 1,12-dodecanediol diglycidyl ether (epoxy equivalent 210 g / eq) in Synthesis Example 1 was replaced with 131.2 g (0.41 mol) of 1,6-hexanediol diglycidyl ether ("SR-16H" manufactured by Sakamoto Pharmaceutical Co., Ltd.: epoxy equivalent 160 g / eq) and 86.6 g (0.09 mol) of polypropylene glycol diglycidyl ether ("DENACOLEX-931" manufactured by Nagase ChemteX Co., Ltd.: epoxy equivalent 481 g / eq). Otherwise, the reaction proceeded in the same manner as in Synthesis Example 1 to obtain 320 g of hydroxyl compound (Ph-10). The hydroxyl compound (Ph-10) exhibited a peak at M+=1684 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ph-10) with n1=6, m1=1, n2=11, m2=1. Therefore, it was confirmed that it contains a hydroxyl compound as the target. The hydroxyl equivalent of the hydroxyl compound (Ph-10) calculated according to GPC is 1597 g / eq.

[0288]

[0289] Synthesis example 11

[0290] While purging the flask equipped with a thermometer, dropping funnel, cooling pipe, and stirrer with nitrogen, 200 g of the hydroxyl compound (Ph-1) obtained in Synthesis Example 1, 437 g (4.72 mol) of epichlorohydrin, and 118 g of n-butanol were added and dissolved. After heating to 65°C, the pressure was reduced to the azeotropic pressure, and 6.66 g (0.08 mol) of 49% sodium hydroxide aqueous solution was added dropwise over 5 hours. Then, stirring was continued under the same conditions for 0.5 hours. During this period, the distillate obtained through azeotropic distillation was separated using a Dean-Stark water separator, the water layer was removed, and the oil layer was returned to the reaction system while the reaction continued. Unreacted epichlorohydrin was then distilled off by vacuum distillation. 150 g of methyl isobutyl ketone and 150 g of n-butanol were added to the resulting crude epoxy resin and dissolved. Next, 10g of a 10% sodium hydroxide aqueous solution was added to the solution, and the mixture was reacted at 80°C for 2 hours. Then, the solution was washed three times repeatedly with 50g of water until the pH of the washing solution was neutral. The system was then dehydrated by azeotropic distillation, and after precise filtration, the solvent was removed by distillation under reduced pressure to obtain 190g of epoxy resin (Ep-1). The epoxy equivalent of the obtained epoxy resin Ep-1 was 2320g / eq. In mass spectrometry, this epoxy resin (Ep-1) showed a peak at M+=883, corresponding to the theoretical structure of the following structural formula (Ep-1) with m1=1, n1=12, p1=0, p2=0, q=1. Therefore, it was confirmed that the resin contained the target epoxy resin (Ep-1).

[0291]

[0292] Synthesis example 12

[0293] The 200g of hydroxyl compound (Ph-1) obtained in Synthesis Example 1 was replaced with 200g of hydroxyl compound (Ph-2) obtained in Synthesis Example 2. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 11 to obtain 180g of epoxy resin (Ep-2). The epoxy equivalent of the obtained epoxy resin (Ep-2) was 1040g / eq. In mass spectrometry, this epoxy resin (Ep-2) showed a peak at M+=883, corresponding to the theoretical structure of the following structural formula (Ep-2) with m1=1, n1=12, p1=0, p2=0, q=1. Therefore, it was confirmed that it contained the target epoxy resin (Ep-2).

[0294]

[0295] Synthesis example 13

[0296] The 200g of hydroxyl compound (Ph-1) obtained in Synthesis Example 1 was replaced with 200g of hydroxyl compound (Ph-3) obtained in Synthesis Example 3. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 11 to obtain 190g of epoxy resin (Ep-3). The epoxy equivalent of the obtained epoxy resin (Ep-3) was 2510 g / eq. This epoxy resin (Ep-3) showed a peak at M+=925 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ep-3) with m1=1, n1=15, p1=0, p2=0, q=1. Therefore, it was confirmed that it contained the target epoxy resin (Ep-3).

[0297]

[0298] Synthesis example 14

[0299] The 200g of hydroxyl compound (Ph-1) obtained in Synthesis Example 1 was replaced with 200g of hydroxyl compound (Ph-4) obtained in Synthesis Example 4. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 11 to obtain 192g of epoxy resin (Ep-4). The epoxy equivalent of the obtained epoxy resin (Ep-4) was 2250g / eq. This epoxy resin (Ep-4) showed a peak at M+=841 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ep-4) with m1=1, n1=9, p1=0, p2=0, q=1. Therefore, it was confirmed that it contained the target epoxy resin (Ep-4).

[0300]

[0301] Synthesis Example 15

[0302] The 200g of hydroxyl compound (Ph-1) obtained in Synthesis Example 1 was replaced with 200g of hydroxyl compound (Ph-5) obtained in Synthesis Example 5. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 11 to obtain 190g of epoxy resin (Ep-5). The epoxy equivalent of the obtained epoxy resin (Ep-5) was 2244 g / eq. This epoxy resin (Ep-5) showed a peak at M+=799 in mass spectrometry, corresponding to the theoretical structure of the following structural formula (Ep-5) with m1=1, n1=6, p1=0, p2=0, q=1. Therefore, it was confirmed that it contained the target epoxy resin (Ep-5).

[0303]

[0304] Synthesis example 16

[0305] The 200g of hydroxyl compound (Ph-1) obtained in Synthesis Example 1 was replaced with 200g of hydroxyl compound (Ph-6) obtained in Synthesis Example 6. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 11 to obtain 185g of epoxy resin (Ep-6). The epoxy equivalent of the obtained epoxy resin (Ep-6) was 2834 g / eq. In mass spectrometry, this epoxy resin (Ep-6) showed a peak at M+=1492, corresponding to the theoretical structure of the following structural formula (Ep-6) with m2=1, n2=11, q=1, p1=0, p2=0. Therefore, it was confirmed that it contained the target epoxy resin (Ep-6).

[0306]

[0307] Synthesis example 17]

[0308] The 200g of hydroxyl compound (Ph-1) obtained in Synthesis Example 1 was replaced with 200g of hydroxyl compound (Ph-7) obtained in Synthesis Example 7. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 11 to obtain 188g of epoxy resin (Ep-7). The epoxy equivalent of the obtained epoxy resin (Ep-7) was 1286g / eq. In mass spectrometry, this epoxy resin (Ep-7) showed a peak at M+=1492, corresponding to the theoretical structure of the following structural formula (Ep-7) with m2=1, n2=11, q=1, p1=0, p2=0. Therefore, it was confirmed that it contained the target epoxy resin (Ep-7).

[0309]

[0310] Synthesis Example 18

[0311] The 200g of hydroxyl compound (Ph-1) obtained in Synthesis Example 1 was replaced with 200g of hydroxyl compound (Ph-8) obtained in Synthesis Example 8. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 11 to obtain 191g of epoxy resin (Ep-8). The epoxy equivalent of the obtained epoxy resin (Ep-8) was 1668 g / eq. In mass spectrometry, this epoxy resin (Ep-8) showed a peak at M+=1338, corresponding to the theoretical structure of the following structural formula (Ep-8) with m2=1, n2=11, q=1, p1=0, p2=0. Therefore, it was confirmed that it contained the target epoxy resin (Ep-8).

[0312]

[0313] Synthesis example 19

[0314] The 200g of hydroxyl compound (Ph-1) obtained in Synthesis Example 1 was replaced with 200g of hydroxyl compound (Ph-9) obtained in Synthesis Example 9. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 11 to obtain 190g of epoxy resin (Ep-9). The epoxy equivalent of the obtained epoxy resin (Ep-9) was 2167 g / eq. In mass spectrometry, this epoxy resin (Ep-9) showed a peak at M+=1951, corresponding to the theoretical structure of the following structural formula (Ep-9) with m1=1, n1=6, m2=1, n2=11, q=1, p1=0, p2=0. Therefore, it was confirmed that it contains the structure of the target epoxy resin (Ep-9).

[0315]

[0316] Synthesis example 20

[0317] The 200g of hydroxyl compound (Ph-1) obtained in Synthesis Example 1 was replaced with 200g of hydroxyl compound (Ph-10) obtained in Synthesis Example 10. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 11 to obtain 190g of epoxy resin (Ep-10). The epoxy equivalent of the obtained epoxy resin (Ep-10) was 1835g / eq. In mass spectrometry, this epoxy resin (Ep-10) showed a peak at M+=1796, corresponding to the theoretical structure of the following structural formula (Ep-10) with m1=1, n1=6, m2=1, n2=11, q=1, p1=0, p2=0. Therefore, it was confirmed that the epoxy resin (Ep-10) contained the structure of the target compound.

[0318]

[0319] Synthesis Example 21

[0320] The 119.7 g (0.53 mol) of bisphenol A (hydroxyl equivalent of 114 g / eq) in Synthesis Example 1 was replaced with 228 g (1.0 mol) of bisphenol A (hydroxyl equivalent of 114 g / eq), and the reaction proceeded in the same manner as in Synthesis Example 1 to yield 420 g of hydroxy compound (Ph-11). This hydroxy compound (Ph-11) exhibited a peak at M+=771 in mass spectrometry, corresponding to the theoretical structure of the aforementioned structural formula (Ph-11) with m1=1 and n1=12, thus confirming the presence of the target hydroxy compound. The hydroxyl equivalent of this hydroxy compound (Ph-11) calculated according to GPC was 340 g / eq.

[0321]

[0322] Synthesis Example 22

[0323] The 200g of hydroxyl compound (Ph-1) obtained in Synthesis Example 1 was replaced with 200g of hydroxyl compound (Ph-11) obtained in Synthesis Example 21. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 11 to obtain 205g of epoxy resin (Ep-11). The epoxy equivalent of the obtained epoxy resin (Ep-11) was 461g / eq. In mass spectrometry, this epoxy resin (Ep-11) showed a peak at M+=883, corresponding to the theoretical structure of the following structural formula (Ep-11) with m1=1, n1=12, p1=0, p2=0, q=1. Therefore, it was confirmed that the epoxy resin (Ep-11) contained the structure of the target compound.

[0324]

[0325] Examples 1-14 and Comparative Examples 1-4

[0326] According to the proportions in Tables 1-4, epoxy resin, filler, thermally expandable microparticles, curing agent (1.0 equivalent relative to epoxy), and curing accelerator (0.85 parts by mass relative to a total of 100 parts by mass of epoxy resin) were uniformly mixed using a mixer (THINKY Corporation's "Defoaming Stirring Taro ARV-200") to obtain an epoxy resin composition. Using silicone tubes as spacers, the epoxy resin composition was held in place with an aluminum mirror panel (Engineering Test Service Corporation's "JIS H 4000A1050P") and cured at 170°C for 30 minutes to obtain a cured resin product with a thickness of 0.8 mm.

[0327] Glass transition temperature

[0328] A 0.7 mm thick cured material was cut into pieces 5 mm wide and 40 mm long to serve as test specimens. For this test specimen 1, a viscoelasticity measuring apparatus (DMA: Hitachi Advanced Scientific Corporation solid viscoelasticity measuring apparatus "DMS7100", deformation mode: tensile, measurement mode: sinusoidal vibration, frequency: 1 Hz, heating rate: 3 °C / min) was used to evaluate the peak temperature of tanδ as the glass transition temperature. It should be noted that if multiple peaks exist, multiple glass transition temperatures are recorded in the table.

[0329] Tensile test

[0330] The cured material was punched into dumbbell shapes using a punch cutter (JIS K 7161-2-1BA) and used as test pieces. Tensile testing was performed on these test pieces using an Autograph AG-IS machine (manufactured by Shimadzu Corporation) according to JIS K7162-2, and the elongation at break at an ambient temperature of 23°C was evaluated (test speed: 2 mm / min).

[0331] Tensile shear test

[0332] A resin composition was applied to one of two cold-rolled steel sheets (TP Giken Co., Ltd.'s "SPCC-SB", 1.0mm × 25mm × 100mm). Glass beads (Potters-Ballotini Co., Ltd.'s "J-80") were added as spacers, and the other SPCC-SB sheet (bonding area: 25mm × 12.5mm) was then bonded to it. The sheet was cured at 170°C for 30 minutes to obtain a test piece. Tensile shear tests were performed on this test piece to evaluate the adhesion. The tests were conducted according to JIS K 6850, and the maximum point stress at an ambient temperature of 23°C was measured comparatively.

[0333] Initial adhesion: Shear test is performed without special treatment of the prepared test piece.

[0334] Adhesion after heating: The prepared test piece was heated at 200℃ for 30 minutes using a heating dryer and then subjected to a shear test.

[0335] Disintegration evaluation

[0336] The strength reduction rate is calculated using the formula: (initial bond strength - bond strength after heating) / initial bond strength × 100.

[0337] Structural periodicity

[0338] Cross-sections of the cured resin were prepared using a slicing machine for periodic structural observation. Scanning electron microscopy (SEM) was used to clearly distinguish morphological contrasts. SEM observations confirmed the presence or absence of phase-separated structures in the cured material. In cases where the cured material exhibited phase-separated structures forming island-like structures, the particle size of the islands was measured. It should be noted that the average particle size was calculated by randomly selecting 50 islands from a 200 μm × 260 μm field of view and measuring their particle size.

[0339] SEM

[0340] Model used: JSM-7800F manufactured by Nippon Electronics Co., Ltd.; Accelerating voltage: 5kV

[0341] [Table 1]

[0342]

[0343] [Table 2]

[0344]

[0345] [Table 3]

[0346]

[0347] [Table 4]

[0348]

[0349] It should be noted that the various mixtures shown in the table are as follows.

[0350] Epoxy Resin B: EPICLON 850S epoxy resin manufactured by DIC (bisphenol A type liquid epoxy resin, epoxy equivalent of 188 g / eq).

[0351] Filler: CaCO3 manufactured by Omi Chemical Industry Co., Ltd.

[0352] Thermally expandable microparticles: Matsumoto Yushi Pharmaceutical Co., Ltd.'s microcapsules F-260D

[0353] Curing agent: Dicyandiamide (DICY7) manufactured by Mitsubishi Chemical Corporation

[0354] Curing accelerator: B-605-IM (3-(3,4-dichlorophenyl)-1,1-dimethylurea) manufactured by DIC Corporation

[0355] It should be noted that in Comparative Example 4, the resin did not cure within the specified curing time, therefore it could not be evaluated.

Claims

1. An epoxy resin composition, characterized in that, It contains: The epoxy resin (A) with an epoxy equivalent of 500~10,000 g / eq is shown in the following general formula (1). Epoxy resin (B) with an epoxy equivalent of 100~300 g / eq; and Thermally expandable particles (C). In formula (1), Ar is independently a structure containing an aromatic ring that is either unsubstituted or has substituents; X is the structural unit shown in general formula (2) below, and Y is the structural unit shown in general formula (3) below. R 11 , R 12 each independently is a glycidyl ether group or a 2-methyl glycidyl ether group; R 13 R 14 Each can be independently a hydroxyl, glycidyl ether, or 2-methylglycidyl ether group; R 15 R 16 It can be a hydrogen atom or a methyl group; m1, m2, p1, p2, and q are the average values ​​of repeated samples; m1 and m2 are each independently between 0 and 25, and m1 + m2 ≥ 1; p1 and p2 are each independently 0~5; q is 0.5~5, Wherein, the bonding of X represented by general formula (2) and Y represented by general formula (3) can be randomly or block, and the total number of each structural unit X and Y present in 1 molecule is m1 and m2, respectively. In equations (2) and (3), Ar is the same as described above. R1 and R2 are each 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 can be independently a hydrogen atom or a methyl group. n1 is an integer between 4 and 16. n² is calculated as the average value of the repeating units, ranging from 2 to 30. The proportion of the thermally expandable particles (C) used is in the range of 3 to 40 parts by mass relative to the total 100 parts by mass of the epoxy resin (A) and the epoxy resin (B).

2. The epoxy resin composition according to claim 1, wherein, In the general formulas (1) to (3), Ar is each independently any of the ones shown in the following structural formula (4). The aromatic ring in formula (4) may be substituted or unsubstituted, and * indicates the bonding site.

3. The epoxy resin composition according to claim 1, wherein, In the general formula (2), n1 is 6~12, R3 and R4 are hydroxyl groups, and R5 and R6 are hydrogen atoms.

4. The epoxy resin composition according to claim 1, wherein, In the general formula (3), R' is a divalent hydrocarbon group with 2 to 6 carbon atoms, R7 and R8 are hydroxyl groups, and R9 and R... 10 It is a hydrogen atom.

5. The epoxy resin composition according to claim 1, wherein, The epoxy equivalent of the epoxy resin (A) is in the range of 800~5000 g / eq.

6. The epoxy resin composition according to claim 1, wherein, The mass ratio (A):(B) of the epoxy resin (A) to the epoxy resin (B) is 90:10 to 10:

90.

7. The epoxy resin composition according to claim 1, further comprising a curing agent (D).

8. The epoxy resin composition according to claim 1, wherein, The thermally expandable particles (C) are thermally expandable microcapsules.

9. The epoxy resin composition according to claim 8, wherein, The thermally expandable particles (C) are thermally expandable microcapsules made by using the following polymer as the outer shell polymer, which is formed by polymerizing nitrile monomers and monomers with carboxyl groups as essential components.

10. The epoxy resin composition according to claim 1, wherein it is an adhesive.

11. A cured product, which is a cured product of the epoxy resin composition according to any one of claims 1 to 10.

12. A laminate formed by laminating a substrate with the cured product of claim 11.

13. A laminate formed by laminating a first substrate, a layer formed from the cured material of claim 11, and a second substrate in that order.

14. The laminate according to claim 13, wherein, The first substrate is a substrate formed of metal or metal oxide, and the second substrate is a substrate formed of plastic.

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