Curing agent for epoxy resins, epoxy resin composition, cured object, sealing material, and adhesive

Abstract

Provided is a curing agent for epoxy resins which comprises an aromatic amine compound (A-1) and one or more aromatic amine adducts (A-2) that are products of reaction between an aromatic amine compound and a reactive compound having a functional group capable of reacting with the aromatic amine compound, wherein the aromatic amine adducts (A-2) include an aromatic amine adduct (A-2-1) formed by uniting one molecule of the reactive compound to one molecule of the aromatic amine compound (A-1) by addition reaction. The ratio of the aromatic amine compound to the aromatic amine adduct (A-2-1), (A-1) / (A-2-1), obtained by analysis by liquid chromatography (UV detector), is 0.50-2.00.

Description

Epoxy resin curing agents, epoxy resin compositions, cured products, sealing materials and adhesives

[0001] The present invention relates to a curing agent for epoxy resins, an epoxy resin composition, a cured product, a sealing material, and an adhesive.

[0002] Epoxy resins are used in a wide range of applications, such as paints, electrical and electronic insulating materials, and adhesives, because their cured products have a variety of properties.

[0003] Patent Document 1 describes an epoxy resin represented by a specific general formula.

[0004] Patent Document 2 describes an epoxy resin composition comprising (A) an epoxy resin, (B) an aromatic amine-based curing agent, (C) a curing accelerator, and (D) a stabilizer, wherein the ratio of the equivalents of all amino groups in the aromatic amine-based curing agent (B) to 1 equivalent of all epoxy groups in the epoxy resin (A) is 0.7 to 1.5, the curing accelerator (C) is an organic boron compound selected from aryl borate salts or aryl borane complexes, and the stabilizer (D) is an aryl phosphine.

[0005] Japanese Patent No. 6282515 Japanese Patent Application Laid-Open No. 2019-172738

[0006] Currently, commonly used epoxy resin compositions include so-called two-component epoxy resin compositions in which an epoxy resin and a curing agent are mixed at the time of use.

[0007] Although two-component epoxy resin compositions can be cured at room temperature, the epoxy resin and curing agent must be stored separately and then measured and mixed as needed before use. This makes storage and handling cumbersome. Furthermore, since the usable time is limited, it is not possible to premix a large amount of the components, which increases the mixing frequency and inevitably reduces efficiency.

[0008] To solve these problems associated with two-component epoxy resin compositions, several one-component epoxy resin compositions have been proposed, including, for example, epoxy resin compositions in which an epoxy resin curing agent is blended with an epoxy resin.

[0009] Recently, there are a wide variety of demands for electronic devices. These demands include, for example, miniaturization, high functionality, light weight, high performance, and multifunctionality. More specifically, for example, in semiconductor chip mounting technology, there is a demand for finer electrode pads and finer pad pitches, resulting in further miniaturization, miniaturization, and higher density. Furthermore, underfills are used as adhesives to be placed in the gap between a chip and a substrate for purposes such as protecting bump connections and the circuit surface of the chip. To meet the demand for increasingly finer pitches, underfills that can penetrate narrower gaps are required. Furthermore, in recent years, there has been a growing demand not only for finer pitches but also for larger semiconductor chips, potentially increasing the penetration time of underfills. Therefore, underfills are also required to exhibit minimal change in viscosity during penetration at high temperatures and during storage.

[0010] As described above, the latent curing agent constituting the one-component epoxy resin composition is required to have both good curability after mixing with the epoxy resin and good storage stability, as well as good permeability into minute regions such as between densely packed fibers such as carbon fibers and glass fibers, and narrow gaps in electronic components.

[0011] In the above Patent Document 1, the curing agent used is solid, and there is room for improvement in terms of penetration into narrow gaps.

[0012] The above-mentioned Patent Document 2 requires a step of adding an additive to improve the storage stability and adhesiveness of the curing agent, and there is room for improvement in terms of storage and handling.

[0013] The problem to be solved by the present invention is to provide an epoxy resin curing agent that has excellent permeability after being mixed with an epoxy resin and is capable of achieving both curability and storage stability, and an epoxy resin composition, a cured product, a sealant, and an adhesive that each contain the epoxy resin curing agent.

[0014] The present invention includes the following aspects: <1> An epoxy resin curing agent comprising an aromatic amine compound (A-1) and an aromatic amine adduct (A-2) that is a reaction product of the aromatic amine compound and a reactive compound having a functional group reactive with the aromatic amine compound, wherein the aromatic amine adduct (A-2) comprises an aromatic amine adduct (A-2-1) in which one molecule of the reactive compound is added to one molecule of the aromatic amine compound (A-1), and wherein the ratio (A-1 / A-2-1) of the aromatic amine compound to the aromatic amine adduct (A-2-1) obtained by liquid chromatography analysis (UV detector) is 0.50 to 2.00. <2> The epoxy resin curing agent according to <1>, which has a glass transition temperature (Tg) of 20°C or lower as detected by differential scanning calorimetry (DSC analysis) at a heating rate of 5°C / min. <3> The epoxy resin curing agent according to <1> or <2>, wherein a melting point (Tm) is not detected in the range of -20°C to 60°C in differential scanning calorimetry (DSC) measured at a temperature range of -50°C to 200°C and a heating rate of 5°C / min. <4> The epoxy resin curing agent according to any one of <1> to <3>, wherein in the aromatic amine adduct (A-2), the reaction ratio between the aromatic amine compound and the reactive compound (aromatic amine compound / reactive compound) is 1 / 0.95 to 1 / 0.40 on a mass basis. <5> The epoxy resin curing agent according to any one of <1> to <4>, wherein the aromatic amine compound (A-1) is an aromatic amine compound represented by the following formula (1) or (2):

[0015] In formula (1), R １ and R ２ each independently represents a monovalent organic group having 1 to 20 carbon atoms or a halogen; a and b each independently represent an integer of 0 to 4; and X represents a divalent organic group or a single bond.

[0016] In formula (2), R ３represents a monovalent organic group having 1 to 20 carbon atoms or a halogen, and c is an integer of 1 to 4. <6> The epoxy resin curing agent according to any one of <1> to <5>, wherein the reactive compound has a molecular weight of more than 150. <7> The epoxy resin curing agent according to any one of <1> to <6>, wherein the molecular weight ratio of the reactive compound to the aromatic amine compound is 0.5 or more and 1.1 or less. <8> The epoxy resin curing agent according to any one of <1> to <7>, wherein the reactive compound is an epoxy compound having one glycidyl group in the molecule. <9> An epoxy resin composition comprising the epoxy resin curing agent according to any one of <1> to <8>, an epoxy resin (B), and an inorganic filler (C). <10> The epoxy resin composition according to <9>, further comprising a curing accelerator (D). <11> The epoxy resin composition according to <10>, wherein the curing accelerator is at least one selected from the group consisting of a compound (D-1) represented by the following formula (4), the following formula (5), or the following formula (6), and an imidazole-based compound (D-2):

[0017]

[0018]

[0019]

[0020] (In formulas (4) to (6), R １ each independently represents a hydrogen atom or an n-valent organic group having 1 to 15 carbon atoms which may have a hydroxyl group, a carbonyl group, an ester bond or an ether bond; R ２ and R ３ each independently represents an unsubstituted or substituted alkyl group, aryl group, or aralkyl group having 1 to 12 carbon atoms, or combines to form a heterocycle having 7 or less carbon atoms; R ４ R each independently represents a hydrogen atom or an n-valent organic group having 1 to 50 carbon atoms which may contain an oxygen atom; n represents an integer of 1 to 3. ５ represents a negatively charged nitrogen atom, R ６represents a positively charged nitrogen atom.) <12> The epoxy resin composition according to any one of <9> to <11>, wherein the content of the inorganic filler (C) is 50% by mass to 70% by mass, based on the total amount of the epoxy resin composition. <13> The epoxy resin composition according to any one of <9> to <12>, wherein the viscosity after standing at 110°C for 60 minutes is 0.01 Pa·s to 1.50 Pa·s. <14> A cured product of the epoxy resin composition according to any one of <9> to <13>. <15> An encapsulant comprising the cured product according to <14>. <16> The encapsulant according to <15>, which is an encapsulant for semiconductors. <17> An adhesive comprising the epoxy resin composition according to any one of <9> to <13>. <18> A semiconductor package comprising the cured product according to <14>. <19> A method for producing a semiconductor package, comprising a step of producing a semiconductor package using the epoxy resin composition according to <9>.

[0021] According to the present invention, there can be provided an epoxy resin curing agent that, after being mixed with an epoxy resin, has excellent permeability and is capable of achieving both curability and storage stability, as well as an epoxy resin composition, a cured product, a sealant, and an adhesive each containing the epoxy resin curing agent.

[0022] Hereinafter, a detailed description will be given of an embodiment of the present invention (hereinafter simply referred to as "the present embodiment"). The following embodiment is an example for explaining the present invention and is not intended to limit the present invention to the following content. The present invention can be implemented by appropriate modifications within the scope of the gist thereof. In this specification, when a numerical value or physical property value is enclosed before and after "~", the preceding and following values ​​are included. In the numerical ranges described in this specification in stages, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with a value shown in the Examples. In the description of groups (atomic groups) in this specification, a notation that does not specify whether they are substituted or unsubstituted includes both unsubstituted and substituted groups. For example, the term "alkyl group" includes not only alkyl groups without substituents (unsubstituted alkyl groups) but also alkyl groups with substituents (substituted alkyl groups).

[0023] <Epoxy Resin Curing Agent> The epoxy resin curing agent of the present embodiment comprises an aromatic amine compound (A-1) and an aromatic amine adduct (A-2) that is a reaction product of the aromatic amine compound and a reactive compound having a functional group capable of reacting with the aromatic amine compound, wherein the aromatic amine adduct (A-2) comprises an aromatic amine adduct (A-2-1) in which one molecule of the reactive compound is added to one molecule of the aromatic amine compound (A-1), and the ratio (A-1 / A-2-1) of the aromatic amine compound to the aromatic amine adduct (A-2-1) obtained by liquid chromatography analysis (UV detector) is 0.50 to 2.00.

[0024] The epoxy resin curing agent of the present embodiment contains the above-described components, and therefore after being mixed with an epoxy resin, can have excellent permeability and can achieve both curability and storage stability.

[0025] In the epoxy resin curing agent of this embodiment, the aromatic amine adduct (A-2) may include an aromatic amine adduct (A-2-1) in which one molecule of a reactive compound is added to one molecule of an aromatic amine compound (A-1), and an aromatic amine adduct (A-2-2X) in which two or more molecules of a reactive compound are added to one molecule of an aromatic amine compound (A-1).

[0026] In the epoxy resin curing agent of this embodiment, the aromatic amine adduct (A-2) comprises an aromatic amine adduct (A-2-1) in which one molecule of a reactive compound is added to one molecule of the aromatic amine compound (A-1). Furthermore, the ratio (A-1 / A-2-1) of the aromatic amine compound (A-1) to the aromatic amine adduct (A-2-1), as determined by liquid chromatography analysis (UV detector), is 0.50 to 2.00. When (A-1 / A-2-1) is 0.50 or greater, the curing property is more excellent, thereby achieving both curability and storage stability. Furthermore, heat resistance can also be improved. From the above viewpoints, (A-1 / A-2-1) is preferably 0.60 or greater, more preferably 0.70 or greater, and even more preferably 0.80 or greater. On the other hand, when (A-1 / A-2-1) is 2.00 or less, the permeability is more excellent and the storage stability is more excellent, thereby achieving both curability and storage stability. From the above viewpoint, (A-1 / A-2-1) is preferably 1.80 or less, more preferably 1.60 or less, and even more preferably 1.40 or less.

[0027] Here, as the aromatic amine compound, an amine compound having electron-withdrawing properties and an amine compound having multiple functional groups in the side chain are inferior in reactivity as an amine but excellent in stability when formed into an amine adduct, and therefore the ratio (A-1 / A-2-1) of the aromatic amine (A-1) to the aromatic amine adduct (A-2-1) may be large. In other words, the aromatic amine adduct (A-2) contains an aromatic amine adduct (A-2-1) in which one molecule of a reactive compound is added to one molecule of the aromatic amine compound (A-1). Examples of the aromatic amine compound include 4,4'-diaminodiphenyl sulfone, diethyltoluenediamine (2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene), and dimethylthiotoluenediamine.

[0028] On the other hand, aromatic amine compounds that do not have electron-withdrawing properties and amine compounds that do not have a functional group in the side chain are highly reactive as amines and have excellent curing properties when formed into an amine adduct, so the ratio of aromatic amine (A-1) to aromatic amine adduct (A-2-1) may be small. In other words, the aromatic amine adduct (A-2) contains an aromatic amine adduct (A-2-1) in which one molecule of a reactive compound is added to one molecule of the aromatic amine compound (A-1). Furthermore, the ratio (A-1 / A-2-1) of the aromatic amine compound (A-1) to the aromatic amine adduct (A-2-1) obtained by liquid chromatography analysis (UV detector) is preferably 0.50 to 2.00, more preferably 0.50 to 1.30, and even more preferably 0.50 to 1.10. Among these, aromatic amine compounds having a -CO-, -C(=O)O-, - or -C(=O)NH- bond are preferred, and aromatic amines having a -C(=O)O- bond are particularly preferred. Examples of the aromatic amine compound include 4-aminophenyl-4-aminobenzoate (APAB), 3,4'-diaminodiphenyl ether (34ODA), and 1,3-bis(3-aminophenoxy)benzene (TPE-M), and among these, 4-aminophenyl-4-aminobenzoate (APAB) is particularly preferred.

[0029] [Analysis of Components in Epoxy Resin Curing Agent] The method for analyzing each component in the epoxy resin curing agent is as follows. After adjusting the concentration of the amine adduct synthesized in the Synthesis Example to 10% by mass with THF, a 1 mg / mL acetonitrile solution was prepared and subjected to LC / MS measurement. The detailed conditions for the LC / MS measurement are as follows. LC; Apparatus: Waters, UPLC Column: Waters, ACQUITY UPLC BEH C8 1.7 μm (2.1 mm I.D. × 50 mm) Detection: PDA 200-400 nm Flow rate: 0.3 mL / min Mobile phase: A = water (0.1% HCOOH) B = acetonitrile (0.1% HCOOH)

[0030]

[0031] Injection volume: 0.2 μL MS; Apparatus: Waters Synapt G2 Ionization: ESI+ Measurement range: m / z 50 to 2000 Each peak area of ​​the PDA chromatogram at 300 nm obtained by the above LC / MS measurement is determined, and the peak areas of the aromatic amine compound (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) are calculated from the peak area ratio according to the following calculation formula (1). The ratio of each peak area is calculated from the sum of all the obtained peak areas using the following calculation formula (1): Ratio of aromatic amine compound (%): [(peak area of ​​amine compound) / {(peak area of ​​amine compound)+(peak area of ​​mono-adduct)+(peak area of ​​multi-adduct)}]×100 (calculation formula (1))

[0032] <Aromatic Amine Compound (A-1)> The epoxy resin curing agent of this embodiment contains an aromatic amine compound (A-1). The aromatic amine compound (A-1) is preferably an aromatic amine compound represented by the following formula (1) or (2):

[0033]

[0034] In formula (1), R １ and R ２each independently represents a monovalent organic group having 1 to 20 carbon atoms or a halogen; a and b each independently represent an integer of 0 to 4; and X represents a divalent organic group or a single bond.

[0035] R １ and R ２ In the formula (I), the monovalent organic group having 1 to 20 carbon atoms preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. a and b are each independently an integer of 0 to 2, and more preferably 0 or 1. In the formula (I), the divalent organic group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 6 carbon atoms.

[0036] Examples of aromatic amines represented by formula (1) include 4-aminophenyl-4-aminobenzoate (APAB), 2-methyl-4-aminophenyl-4-aminobenzoate, 3-methyl-4-aminophenyl-4-aminobenzoate, 2-fluoro-4-aminophenyl-4-aminobenzoate, 3-fluoro-4-aminophenyl-4-aminobenzoate, 3-methyl-4-aminophenyl-3-methyl-4-aminobenzoate, 4,4'-diaminobenzanilide, 4,4'-diaminodiphenyl ether ... , 4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, 4,4-bis(4-aminophenoxy) Biphenyl, 4,4-bis(3-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 9,10-bis(4-aminophenyl)anthracene, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-biphenyl bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(3-aminopropyldimethylsilyl)benzene, m-tolidine, 2,2'-bis(trifluoromethyl)benzidine, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, bis(4-amino-3,5-dimethylphenyl)methane, 4,4'-diamino-3,3'-5,Among these, from the viewpoint of achieving both curability and stability when combined with an epoxy resin, X is preferably —CO—, —C(═O)O—, —SO, ２ Aromatic amines having a - or -C(=O)NH- bond are preferred, and among these, aromatic amines having a -C(=O)O- bond are preferred. Aromatic amine compounds having a methanediyl group, which has high amine reactivity, can also be used. For the purpose of suppressing amine reactivity and improving storage stability, it is preferable to use compounds other than aromatic amine compounds having a methanediyl group. Examples of aromatic amine compounds having a methanediyl group include 4,4'-diaminodiphenylmethane and 3,3'-diaminodiphenylmethane.

[0037]

[0038] In formula (2), R ３ represents a monovalent organic group having 1 to 20 carbon atoms or a halogen, and c is an integer of 1 to 4. ３ In the formula (I), the monovalent organic group having 1 to 20 carbon atoms preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. c is preferably an integer of 1 to 3, and more preferably 1 or 2.

[0039] Examples of aromatic amines represented by formula (2) include diethyltoluenediamine (2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene), dimethylthiotoluenediamine, etc., and it is preferable to use one or more selected from these. Among these, diethyltoluenediamine (2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene) is preferred as the aromatic diamine from the viewpoint of achieving both curability and stability when formed into a composition with an epoxy resin. Examples of aromatic amine compounds include 4-aminophenyl-4-aminobenzoate (APAB), 3,4'-diaminodiphenyl ether (34ODA), 1,3-bis(3-aminophenoxy)benzene (TPE-M), etc., and among these, 4-aminophenyl-4-aminobenzoate (APAB) is preferred.

[0040] <Aromatic Amine Adduct (A-2)> The aromatic amine adduct (A-2) is a reaction product of the aromatic amine compound (A-1) and a reactive compound having a functional group capable of reacting with the aromatic amine compound (A-1).

[0041] (Reactive Compound)

[0042] The reactive compound has a functional group capable of reacting with the aromatic amine compound (A-1). Examples of the functional group include a -C(=O)OC(=O)- group, a carboxyl group, a sulfo group, an isocyanato group, a carbonyl group, an epoxy group, a fluoro group, a chloro group, a bromo group, and an iodo group. The reactive compound is preferably at least one compound selected from the group consisting of an acid anhydride, an acid dianhydride, a carboxylic acid compound, a sulfonic acid compound, an isocyanate compound, a urea compound, an epoxy compound, and an alkyl halide.

[0043] Examples of the carboxylic acid compound include succinic acid, adipic acid, sebacic acid, phthalic acid, and dimer acid.

[0044] Examples of sulfonic acid compounds include ethanesulfonic acid and p-toluenesulfonic acid.

[0045] Examples of isocyanate compounds include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, aliphatic triisocyanates, and polyisocyanates. Examples of aliphatic diisocyanates include ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate. Examples of alicyclic diisocyanates include isophorone diisocyanate, 4-4'-dicyclohexylmethane diisocyanate, norbornane diisocyanate, 1,4-isocyanatocyclohexane, 1,3-bis(isocyanatomethyl)-cyclohexane, and 1,3-bis(2-isocyanatopropyl-2-yl)-cyclohexane. Examples of aromatic diisocyanates include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylene diisocyanate, and 1,5-naphthalene diisocyanate. Examples of aliphatic triisocyanates include 1,3,6-triisocyanatomethylhexane and 2,6-diisocyanatohexanoate-2-isocyanatoethyl. Examples of polyisocyanates include polymethylene polyphenyl polyisocyanate and polyisocyanates derived from the above diisocyanate compounds. Examples of polyisocyanates derived from the above diisocyanates include isocyanurate-type polyisocyanates, biuret-type polyisocyanates, urethane-type polyisocyanates, allophanate-type polyisocyanates, and carbodiimide-type polyisocyanates.

[0046] Examples of the urea compound include urea, methyl urea, dimethyl urea, ethyl urea, and t-butyl urea.

[0047] The epoxy compound may be a monoepoxy compound, a polyepoxy compound, or a mixture thereof. Examples of the monoepoxy compound include butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether, 2-ethylhexyl glycidyl ether, dodecyl glycidyl ether, allyl glycidyl ether, para-tert-butylphenyl glycidyl ether, ethylene oxide, propylene oxide, paraxylyl glycidyl ether, glycidyl acetate, glycidyl butyrate, glycidyl hexoate, and glycidyl benzoate.Examples of polyfunctional epoxy compounds include bisphenol-type epoxy compounds obtained by glycidylating bisphenols such as bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol AD, tetramethylbisphenol S, tetrabromobisphenol A, tetrachlorobisphenol A, and tetrafluorobisphenol A; epoxy compounds obtained by glycidylating dihydric phenols such as biphenol, dihydroxynaphthalene, and 9,9-bis(4-hydroxyphenyl)fluorene; epoxy compounds obtained by glycidylating trisphenols such as 1,1,1-tris(4-hydroxyphenyl)methane and 4,4-(1-(4-(1-(4-hydroxyphenyl)-1-methylethyl)phenyl)ethylidene)bisphenol; and epoxy compounds obtained by glycidylating tetrakisphenols such as 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane. compounds; novolac-type epoxy compounds obtained by glycidylating novolacs such as phenol novolac, cresol novolac, bisphenol A novolac, brominated phenol novolac, and brominated bisphenol A novolac; aliphatic ether-type epoxy compounds obtained by glycidylating polyhydric alcohols such as glycerin and polyethylene glycol; ether ester-type epoxy compounds obtained by glycidylating hydroxycarboxylic acids such as p-oxybenzoic acid and β-oxynaphthoic acid; ester-type epoxy compounds obtained by glycidylating polycarboxylic acids such as phthalic acid and terephthalic acid; glycidyl-type epoxy compounds such as epoxy compounds obtained by glycidylating amine compounds such as 4,4-diaminodiphenylmethane and m-aminophenol, and epoxy compounds obtained by glycidylating amine-type epoxy compounds such as triglycidyl isocyanurate; and alicyclic epoxy compounds such as 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexanecarboxylate.

[0048] Among the above, from the viewpoint of excellent curability and storage stability, the reactive compound is preferably an epoxy compound, and more preferably an epoxy compound having one glycidyl group in the molecule.

[0049] In order to achieve both high curability and storage stability, the total chlorine content of the epoxy compound is preferably 400 ppm or less, more preferably 300 ppm or less, even more preferably 200 ppm or less, particularly preferably 180 ppm or less, even more preferably 171 ppm or less, still more preferably 100 ppm or less, particularly preferably 80 ppm or less, and even more preferably 50 ppm or less.

[0050] In this embodiment, the total chlorine content refers to the total amount of organic chlorine and inorganic chlorine contained in the compound, and is a value based on the mass of the compound. Of the total chlorine, the chlorine contained in 1,2-chlorohydrin groups is generally referred to as hydrolyzable chlorine. The amount of hydrolyzable chlorine in the epoxy compound used in this embodiment is preferably 50 ppm or less, more preferably 0.01 to 20 ppm, and even more preferably 0.05 to 10 ppm. A hydrolyzable chlorine content of 50 ppm or less is advantageous for achieving both high curability and storage stability, and is preferred because it exhibits excellent electrical properties. In this embodiment, when it is desired to reduce the total chlorine content of the epoxy compound, examples include a method in which a dechlorination reaction is carried out using a base catalyst in an aprotic solvent, followed by purifying the epoxy compound by washing with water, and a method in which a dechlorination reaction is carried out using a metal amide compound such as a bis(trialkylsilyl)amide metal salt as a catalyst, followed by purifying the epoxy compound by washing with water. The molecular weight of the reactive compound is preferably greater than 150, more preferably 160 or more, and even more preferably 180 or more, particularly from the standpoint of storage stability. The molecular weight of the reactive compound may be 250 or less, 220 or less, or 200 or less. Furthermore, the molecular weight ratio of the reactive compound to the aromatic amine compound (reactive compound / aromatic amine compound) is preferably 0.5 or more, more preferably 0.6 or more, and even more preferably 0.7 or more, from the viewpoint of flowability. Furthermore, from the viewpoint of heat resistance, it is preferably 1.1 or less, more preferably 1.0 or less, and even more preferably 0.9 or less.

[0051] The aromatic amine adduct (A-2) is a reaction product of an aromatic amine compound (A-1) and a reactive compound having a functional group capable of reacting with the aromatic amine compound (A-1). The aromatic amine adduct (A-2) used in this embodiment can be obtained, for example, by reacting 1 to 5 moles of the aromatic amine compound (A-1) with 1 to 5 moles of a reactive compound (e.g., an epoxy compound) in the presence of a solvent, for example, at a temperature of 50 to 250°C for 0.1 to 10 hours, and then removing the unreacted aromatic amine compound (A-1) and the solvent, as necessary. The solvent used here is not particularly limited, but examples thereof include hydrocarbons such as benzene, toluene, xylene, cyclohexane, mineral spirits, naphtha, etc.; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.; esters such as ethyl acetate, n-butyl acetate, propylene glycol monomethyl ether acetate, etc.; alcohols such as methanol, isopropanol, n-butanol, butyl cellosolve, butyl carbitol, etc.; water, etc., and these solvents may be used in combination.

[0052] In the aromatic amine adduct (A-2), the reaction ratio between the aromatic amine compound and the reactive compound (aromatic amine compound / reactive compound) is preferably 1 / 0.95 to 1 / 0.40 on a substance basis. For example, when the reaction ratio (aromatic amine compound / reactive compound) is within the above range, the ratio (A-1 / A-2-1) can be easily adjusted to the above range. More specifically, the ratio (A-1 / A-2-1) can be adjusted to the above range by adjusting the reaction ratio (aromatic amine compound / reactive compound) according to the reactivity of the aromatic amine compound and the reactive compound. Specifically, aromatic amine compounds having electron-withdrawing properties and amine compounds having multiple functional groups in their side chains tend to have poor reactivity as amines, and when formed into an amine adduct, the ratio of aromatic amine (A-1) tends to be lower than that of other amines. On the other hand, aromatic amine compounds that do not have electron-withdrawing properties and amine compounds that do not have a functional group in the side chain tend to be highly reactive as amines, and the ratio of aromatic amine (A-1) when formed into an amine adduct tends to be higher than that of other amines. Here, aromatic amine compounds that have electron-withdrawing properties and amine compounds that have multiple functional groups in the side chain tend to be poorer in reactivity as amines but have excellent stability when formed into an amine adduct, so the ratio of aromatic amine (A-1) to aromatic amine adduct (A-2-1) may be high. That is, in the aromatic amine adduct (A-2), the reactivity ratio of the aromatic amine compound to the reactive compound (aromatic amine compound / reactive compound) is preferably 1 / 0.95 to 1 / 0.40, more preferably 1 / 0.8 to 1 / 0.4, and even more preferably 1 / 0.65 to 1 / 0.4, based on the amount of substance. Examples of the aromatic amine compound include 4,4'-diaminodiphenyl sulfone, diethyltoluenediamine (2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene), and dimethylthiotoluenediamine.

[0053] On the other hand, aromatic amine compounds that do not have electron-withdrawing properties and amine compounds that do not have a functional group in the side chain are highly reactive as amines and exhibit excellent curability when formed into an amine adduct, so the ratio of aromatic amine (A-1) to aromatic amine adduct (A-2-1) may be small. That is, in the aromatic amine adduct (A-2), the reaction ratio of the aromatic amine compound to the reactive compound (aromatic amine compound / reactive compound) is preferably 1 / 0.95 to 1 / 0.40, more preferably 1 / 0.95 to 1 / 0.6, and even more preferably 1 / 0.95 to 1 / 0.7, based on the amount of substance.

[0054] When an epoxy resin curing agent having a glass transition temperature (Tg) of more than 5°C is used, the resulting epoxy resin composition has poor flowability and therefore poor penetration. In the above cases, the Tg and Tm of the epoxy resin curing agent are relatively high, resulting in poor viscosity when formed into an epoxy resin composition, resulting in poor flowability. When an epoxy resin curing agent having a glass transition temperature (Tg) of more than 5°C is used, the resulting epoxy resin composition may have excellent viscosity stability but poor curability and a low Tg. This is thought to be due to the use of an amine having an electron-withdrawing group as the aromatic amine compound, which reduces reactivity and compatibility with the epoxy resin. Furthermore, when an epoxy resin curing agent having a glass transition temperature (Tg) of more than 5°C is used, the resulting epoxy resin composition has low viscosity, but poor viscosity stability and poor flowability. This is due to the aromatic amine compound being too reactive.

[0055] (Glass Transition Temperature (Tg)) The epoxy resin curing agent of this embodiment preferably has a glass transition temperature (Tg) of 20°C or less, as detected by differential scanning calorimetry (DSC analysis) at a temperature rise rate of 5°C / min. A Tg of 20°C or less can suppress viscosity changes in high-temperature environments during penetration and during storage, resulting in excellent penetration properties. From the above viewpoints, the Tg is more preferably 20°C or less, even more preferably 15°C or less, particularly preferably 10°C or less, and even more preferably 0°C or less. On the other hand, a Tg of -50°C or higher results in more excellent heat resistance. From the above viewpoints, the Tg is preferably -50°C or higher, more preferably -40°C or higher, and even more preferably -30°C or higher.

[0056] The glass transition temperature (Tg) of an epoxy resin curing agent is measured by the following method. Using a differential scanning calorimeter (for example, a differential scanning calorimeter system "DSC Q2000" manufactured by TA Instruments-Waters), a 10 mg sample is heated from -50°C to 200°C at a heating rate of 5°C / min under a nitrogen gas flow (40 mL / min). The Tg of the epoxy resin curing agent is the peak top temperature of the DSC differential curve (JIS K6240:2011).

[0057] (Melting Point (Tm)) The epoxy resin curing agent of this embodiment preferably has at least one melting point (Tm) of less than 60°C as detected by differential scanning calorimetry (DSC analysis) at a temperature rise rate of 5°C / min. A Tm of less than 60°C can suppress viscosity changes in high-temperature environments during penetration and during storage, resulting in excellent penetration properties. From the above viewpoints, Tm is more preferably less than 60°C, even more preferably 50°C or less, and particularly preferably 40°C or less. On the other hand, from the viewpoint of excellent heat resistance, Tm is preferably -40°C or higher, more preferably -30°C or higher, and even more preferably -20°C or higher.

[0058] Alternatively, it is preferable that no melting point (Tm) is detected in the range of -20°C to 60°C in differential scanning calorimetry (DSC analysis) measured in a temperature range of -50°C to 200°C at a heating rate of 5°C / min. Among the compounds having a structure represented by formula (1) or (2), the compounds are amorphous due to the presence of substituents on the side chains, which inhibits intermolecular interactions. In other words, since no melting point (Tm) is detected in the range of -20°C to 60°C, the viscosity at the temperature during penetration and the penetration properties are excellent.

[0059] The melting point (Tm) of an epoxy resin curing agent is measured by the following method. Using a differential scanning calorimeter (for example, a differential scanning calorimeter system "DSC Q2000" manufactured by TA Instruments-Waters), a 10 mg sample is heated from -50°C to 200°C at a heating rate of 5°C / min under a nitrogen gas flow (40 mL / min). The Tm of an epoxy resin curing agent is the apex temperature of the endothermic peak in the DSC curve (JIS K7121:1987).

[0060] <Epoxy Resin Composition> The epoxy resin composition of the present embodiment contains the epoxy resin curing agent of the present embodiment, an epoxy resin (B), and an inorganic filler (C).

[0061] <Epoxy Resin (B)> As the epoxy resin, any commonly used epoxy resin can be used without any particular limitation. For example, an epoxy resin having two or more epoxy groups per molecule is preferred. The epoxy resin may be solid or liquid at room temperature, but from the viewpoint of filling properties, it is preferable that it is liquid at room temperature. The epoxy resin may particularly be an epoxy resin that is liquid at room temperature (hereinafter also referred to as "liquid epoxy resin"), and commonly used liquid epoxy resins can be used. The liquid epoxy resin preferably has a viscosity of, for example, 0.0001 to 10 Pa·s as measured with an E-type viscometer at room temperature.

[0062] Examples of epoxy resins include diglycidyl ether epoxy resins such as bisphenol-type epoxy resins such as bisphenol A, bisphenol F, bisphenol AD, bisphenol S, and hydrogenated bisphenol A; epoxy resins obtained by epoxidizing novolac resins obtained from phenols and aldehydes, such as orthocresol novolac epoxy resins; glycidyl ester epoxy resins obtained by reacting polybasic acids such as phthalic acid and dimer acid with epichlorohydrin; glycidyl amine epoxy resins obtained by reacting amine compounds such as p-aminophenol, diaminodiphenylmethane, and isocyanuric acid with epichlorohydrin; and linear aliphatic epoxy resins and alicyclic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid. One type of epoxy resin may be used alone, or two or more types may be used in combination.

[0063] Among these, for example, bisphenol-type epoxy resins are preferred from the viewpoint of fluidity. Furthermore, for example, glycidyl amine-type epoxy resins are preferred from the viewpoints of heat resistance, adhesiveness, and fluidity. The epoxy resin is preferably at least one selected from the group consisting of bisphenol-type epoxy resins and glycidyl amine-type epoxy resins. As the bisphenol-type epoxy resin, from the viewpoint of fluidity, at least one selected from the group consisting of diglycidyl ether epoxy resins of bisphenol A (bisphenol A-type epoxy resins) and diglycidyl ether epoxy resins of bisphenol F (bisphenol F-type epoxy resins) is preferred. When a bisphenol A-type epoxy resin and a bisphenol F-type epoxy resin are used in combination, their mass ratio (bisphenol A-type epoxy resin:bisphenol F-type epoxy resin) is not particularly limited, but from the viewpoints of heat resistance, adhesiveness, and fluidity, it is preferably, for example, 5:95 to 50:50, more preferably 10:90 to 40:60, and even more preferably 20:80 to 40:60. From the viewpoint of fluidity, it is preferable that both the bisphenol-type epoxy resin and the glycidylamine-type epoxy resin are liquid at room temperature. The bisphenol-type epoxy resin and the glycidylamine-type epoxy resin may be used alone or in combination of two or more. From the viewpoints of heat resistance, adhesion, and fluidity, it is preferable to use a bisphenol-type epoxy resin and a glycidylamine-type epoxy resin in combination. The total content of the bisphenol-type epoxy resin and the glycidylamine-type epoxy resin is not particularly limited, but from the viewpoints of heat resistance, adhesion, and fluidity, it is preferably, for example, 20% by mass or more, more preferably 30% by mass or more, even more preferably 50% by mass or more, and particularly preferably 80% by mass or more, based on the total amount of epoxy resin. There is no particular upper limit to the above total content, and it can be determined within a range that achieves desired properties and characteristics from the viewpoints of viscosity, glass transition temperature, heat resistance, etc., and may be 100% by mass.

[0064] When a bisphenol-type epoxy resin and a glycidylamine-type epoxy resin are used in combination, the mass ratio (bisphenol-type epoxy resin:glycidylamine-type epoxy) is not particularly limited, but from the viewpoints of heat resistance, adhesion, and fluidity, it is preferably, for example, 20:80 to 95:5, more preferably 40:60 to 90:10, and even more preferably 60:40 to 80:20. Furthermore, in this embodiment, an epoxy resin that is solid at room temperature can also be used. From the viewpoint of fluidity, the content of the epoxy resin that is solid at room temperature is, for example, preferably 0 to 20 mass%, more preferably 0 to 10 mass%, and even more preferably 0 to 5 mass%, relative to the total amount of epoxy resin. There are no particular limitations on the epoxy equivalent of the epoxy resin, but from the viewpoint of heat resistance, it is preferably 60 to 400 g / mol, more preferably 70 to 300 g / mol, and even more preferably 80 to 250 g / mol. Here, the epoxy equivalent is the mass (g / eq) of resin per epoxy group and can be measured according to the method specified in JIS K 7236. Specifically, using a Mitsubishi Chemical Analytech Corporation automatic titrator "GT-200 Model," 2 g of epoxy resin is weighed into a 200 ml beaker, 90 ml of methyl ethyl ketone is added dropwise, and the mixture is dissolved in an ultrasonic cleaner. 10 ml of glacial acetic acid and 1.5 g of cetyltrimethylammonium bromide are added, and the mixture is titrated with a 0.1 mol / L perchloric acid / acetic acid solution. The purity of the epoxy resin is preferably high. In particular, the amount of hydrolyzable chlorine is preferably low because it is involved in corrosion of aluminum wiring on elements such as integrated circuits (ICs). From the viewpoint of excellent moisture resistance, for example, a level of 500 ppm or less is preferable. Here, the amount of hydrolyzable chlorine is measured by dissolving 1 g of a sample epoxy resin in 30 ml of dioxane, adding 5 ml of a 1N KOH (potassium hydroxide) methanol solution, refluxing for 30 minutes, and then determining the amount of hydrolyzable chlorine by potentiometric titration.The content of the epoxy resin is not particularly limited, but from the viewpoints of heat resistance, adhesiveness, and flowability, it is, for example, preferably 40 to 90 mass %, more preferably 50 to 80 mass %, and even more preferably 55 to 70 mass %, of the total amount of the epoxy resin composition excluding the (C) inorganic filler.

[0065] <Inorganic Filler (C)> The inorganic filler is not particularly limited, and examples thereof include powders such as silica such as fused silica and crystalline silica, calcium carbonate, clay, alumina such as alumina oxide, silicon nitride, silicon carbide, boron nitride, calcium silicate, potassium titanate, aluminum nitride, beryllia, zirconia, zircon, forsterite, steatite, spinel, mullite, and titania, as well as beads obtained by spheronizing these powders, and glass fibers.

[0066] The inorganic filler may be an inorganic filler having a flame retardant effect, such as aluminum hydroxide, magnesium hydroxide, zinc borate, or zinc molybdate.

[0067] The inorganic filler may be used alone or in combination of two or more. Among these, from the viewpoints of availability, chemical stability, and material cost, for example, silica is preferred, and fused silica is more preferred. The particle shape of the inorganic filler is not particularly limited, and may be amorphous or spherical, but from the viewpoints of flowability and permeability into fine gaps in the epoxy resin composition, spherical silica, particularly spherical fused silica, is preferably used.

[0068] In addition, the inorganic filler may be surface-treated. Specifically, the inorganic filler may be surface-treated using a silane coupling agent. Examples of the silane coupling agent include aminosilane coupling agents, epoxysilane coupling agents, phenylsilane coupling agents, alkylsilane coupling agents, alkenylsilane coupling agents, alkynylsilane coupling agents, haloalkylsilane coupling agents, siloxane coupling agents, hydrosilane coupling agents, silazane coupling agents, alkoxysilane coupling agents, chlorosilane coupling agents, (meth)acrylicsilane coupling agents, aminosilane coupling agents, isocyanurate silane coupling agents, ureidosilane coupling agents, mercaptosilane coupling agents, sulfide silane coupling agents, and isocyanate silane coupling agents.

[0069] The volume-average particle size of the inorganic filler is not particularly limited, but is preferably 0.1 to 10 μm, more preferably 0.3 to 5 μm, and even more preferably 0.5 to 3 μm. By setting the volume-average particle size of the inorganic filler to 0.1 μm or more, dispersibility in the epoxy resin is improved, the epoxy resin composition is less likely to be imparted with thixotropy, and the flow characteristics of the epoxy resin composition tend to be improved. On the other hand, by setting the volume-average particle size to 10 μm or less, sedimentation of the inorganic filler in the epoxy resin composition tends to be easily suppressed, and the permeability and flowability of the epoxy resin composition into fine gaps tend to be improved, thereby suppressing the occurrence of voids and unfilled portions. The volume-average particle size refers to the particle size at the point corresponding to 50% volume when a cumulative frequency distribution curve of particle size is calculated, assuming the total volume of the particles to be 100%. This can be measured using a particle size distribution analyzer using a laser diffraction / scattering method.

[0070] The content of the inorganic filler is not particularly limited, but is preferably 50% by mass to 70% by mass relative to the total amount of the epoxy resin composition. By setting the content of the inorganic filler to 50% by mass or more, the effect of reducing the thermal expansion coefficient and the effect of improving temperature cycle resistance tend to be easily obtained. By setting the content of the inorganic filler to 70% by mass or less, the increase in viscosity of the epoxy resin composition tends to be suppressed, and the flowability, penetration, and dispensability tend to be improved. In particular, from the viewpoint of the effect of improving temperature cycle resistance, the higher the lower limit of the content of the inorganic filler, the more preferable. In this embodiment, even if the content of the inorganic filler is increased as described above, it is possible to maintain a low viscosity of the epoxy resin composition.

[0071] <Curing Accelerator (D)> The epoxy resin composition of the present embodiment preferably further contains a curing accelerator (D). The curing accelerator is preferably at least one selected from the group consisting of compounds (D-1) represented by formula (4), formula (5), or formula (6), and imidazole-based compounds (D-2).

[0072] (Compound (D-1)) Compound (D-1) is represented by the following formula (4), (5) or (6).

[0073]

[0074]

[0075]

[0076] (In formulas (4) to (6), R １ each independently represents a hydrogen atom or an n-valent organic group having 1 to 15 carbon atoms which may have a hydroxyl group, a carbonyl group, an ester bond or an ether bond; R ２ and R ３ each independently represents an unsubstituted or substituted alkyl group, aryl group, or aralkyl group having 1 to 12 carbon atoms, or combines to form a heterocycle having 7 or less carbon atoms; R ４ R each independently represents a hydrogen atom or an n-valent organic group having 1 to 50 carbon atoms which may contain an oxygen atom; n represents an integer of 1 to 3. ５represents a negatively charged nitrogen atom, R ６ represents a positively charged nitrogen atom.)

[0077] In formula (4), formula (5) or formula (6), R １ is presumed to contribute to lowering the energy of the N-N bond cleavage. ２ and R ３ It is speculated that this contributes to the lowering of the energy of the cleavage reaction due to instability caused by steric hindrance. ４ It is presumed that these groups contribute to liquefying the compound and preventing a decrease in the glass transition temperature of the resulting cured product. Each group will be described in detail below.

[0078] In formulas (4), (5) and (6), R １ each independently represents a hydrogen atom or an n-valent organic group having 1 to 15 carbon atoms which may have a hydroxyl group, a carbonyl group, an ester bond or an ether bond.

[0079] R １ Among these, the organic group is not particularly limited, but examples thereof include a hydrocarbon group, a group in which a hydrogen atom bonded to a carbon atom in a hydrocarbon group is substituted with a hydroxyl group or a carbonyl group, and a group in which a part of the carbon atoms in a hydrocarbon group is substituted with an ester bond or an ether bond.

[0080] R １ Among these, examples of the hydrocarbon group include linear, branched, or cyclic alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and ethylhexyl groups; alkenyl groups such as vinyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, decynyl, dodecynyl, hexadecynyl, and octadecynyl groups; aryl groups such as phenyl; and aralkyl groups including a combination of an alkyl group and a phenyl group, such as methylphenyl, ethylphenyl, and propylphenyl groups.

[0081] R １The organic group may have other substituents. The substituents are not particularly limited, but examples thereof include a halogen atom, an alkoxy group, a carbonyl group, a cyano group, an azo group, an azido group, a thiol group, a sulfo group, a nitro group, a hydroxy group, an acyl group, and an aldehyde group. １ Among these, the number of carbon atoms in the organic group is 1 to 15, preferably 1 to 12, and more preferably 1 to 7. When the number of carbon atoms in the organic group is within the above range, a liquid compound having an appropriate viscosity is easily obtained, and the curing performance of the compound tends to be further improved. Furthermore, when the number of carbon atoms in the organic group is within the above range, the availability of raw materials is further improved.

[0082] R ２ and R ３ each independently represents an unsubstituted or substituted alkyl group, aryl group, or aralkyl group having 1 to 12 carbon atoms, or combines to form a heterocycle having 7 or less carbon atoms.

[0083] R ２ and R ３ Among these, the alkyl group having 1 to 12 carbon atoms is not particularly limited, and examples thereof include linear alkyl groups such as methyl, ethyl, propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-decyl, and n-dodecyl; branched alkyl groups such as isopropyl, isobutyl, t-butyl, neopentyl, 2-hexyl, 2-octyl, 2-decyl, and 2-dodecyl; and cyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclodecyl, and cyclododecyl. The alkyl group may be a linear alkyl group or an alkyl group containing a combination of a branched alkyl group and a cyclic alkyl group. Furthermore, the alkyl group may contain an unsaturated bond group.

[0084] R ２ and R ３The number of carbon atoms in the alkyl groups is, independently, 1 to 12, preferably 2 to 10, and more preferably 5 to 10. Asymmetric dialkylhydrazine compounds with a small number of carbon atoms in the alkyl groups (such as dimethylhydrazine) may be explosive and may be toxic to the human body. ２ and R ３ By making the number of carbon atoms of the alkyl group in R 2 or more, it is possible to avoid using raw materials that pose the risk of toxicity, etc. ２ and R ３ By making the number of carbon atoms in the alkyl group 5 or more, a liquid compound having an appropriate viscosity is easily obtained, and the curing performance of the compound tends to be further improved.

[0085] R ２ and R ３ Among them, the aryl group is not particularly limited, but examples thereof include a phenyl group and a naphthyl group.

[0086] R ２ and R ３ Among them, the aralkyl group is not particularly limited, but examples thereof include a methylphenyl group, an ethylphenyl group, a methylnaphthyl group, and a dimethylnaphthyl group.

[0087] Among these, R ２ and R ３ As R, an aralkyl group is preferred, and a methylphenyl group (benzyl group) is more preferred. This tends to further improve the curing performance of the compound. ２ or R ３ The number of carbon atoms in the aryl group and aralkyl group represented by the formula (I) is not particularly limited, but is 6 to 20.

[0088] R ２ and R ３ Among these, the substituent of the alkyl group, aryl group, or aralkyl group is not particularly limited, and examples thereof include a halogen atom, an alkoxy group, a carbonyl group, a cyano group, an azo group, an azido group, a thiol group, a sulfo group, a nitro group, a hydroxy group, an acyl group, and an aldehyde group.

[0089] R ２ and R ３may be linked to form a heterocycle having 7 or less carbon atoms. The heterocycle is not particularly limited, and examples thereof include 4-membered rings such as an azetidine ring; 5-membered rings such as a pyrrolidine ring, a pyrrole ring, a morpholine ring, and a thiazine ring; 6-membered rings such as a piperidine ring; and 7-membered rings such as a hexamethyleneimine ring and an azepine ring. Among these, the heterocycle is preferably a pyrrole ring, a morpholine ring, a thiazine ring, a piperidine ring, a hexamethyleneimine ring, or an azepine ring, with 6-membered rings and 7-membered rings being more preferred. The presence of such a group makes it easier to obtain a liquid compound and tends to further improve the curing performance of the compound.

[0090] The substituent is not particularly limited, but may be, for example, an alkyl group, an aryl group, or the above-mentioned R ２ and R ３ Furthermore, when the heterocycle has an alkyl group as a substituent, R ６ and a methyl group bonded to a carbon atom adjacent to the carbon atom.

[0091] In formulas (4), (5) and (6), R ４ R each independently represents a hydrogen atom or an n-valent organic group having 1 to 50 carbon atoms and optionally containing an oxygen atom. ４ Among them, the organic group is not particularly limited, but examples thereof include a hydrocarbon group, a group in which a hydrogen atom bonded to a carbon atom in a hydrocarbon group is substituted with a hydroxyl group, a carbonyl group, or a group containing a silicon atom, and a group in which a part of the carbon atoms in a hydrocarbon group is substituted with an ester bond, an ether bond, or a silicon atom. ４ Among these, examples of the hydrocarbon group include linear, branched, or cyclic alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and ethylhexyl groups; alkenyl groups such as vinyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, decynyl, dodecynyl, hexadecinyl, and octadecynyl groups; aryl groups such as phenyl; and aralkyl groups including a combination of an alkyl group and a phenyl group, such as methylphenyl, ethylphenyl, and propylphenyl groups.

[0092] R ４ Among these, the hydrocarbon group may include a bisphenol skeleton such as a bisphenol A skeleton, a bisphenol AP skeleton, a bisphenol B skeleton, a bisphenol C skeleton, a bisphenol E skeleton, or a bisphenol F skeleton. The organic group containing a bisphenol skeleton is not particularly limited, but examples thereof include groups in which a polyoxyalkylene group is added to the hydroxyl group of each bisphenol skeleton.

[0093] Among these, R in formula (4) or formula (5) ４ The organic group represented by the formula (I) is preferably an alkyl group, an alkenyl group, or an aralkyl group, more preferably an alkyl group or an alkenyl group, and even more preferably a branched alkyl group or a branched alkenyl group. These preferred groups may have a substituent. By having such a group, it is easy to obtain a liquid compound having an appropriate viscosity, and the curing performance of the compound tends to be further improved. In addition, the Tg of the cured product obtained using the compound tends to be further improved.

[0094] R ４ The number of carbon atoms in the organic group is 1 to 50, preferably 1 to 30, more preferably 1 to 20, more preferably 1 to 15, and even more preferably 1 to 8. ４ When the number of carbon atoms in the organic group is within the above range, a liquid compound having an appropriate viscosity is easily obtained, and the curing performance of the compound tends to be further improved. In addition, the Tg of the cured product obtained using this compound is further improved, and further, ４ When the number of carbon atoms of the organic group in the hydroxyl group is within the above range, the availability of raw materials is further improved.

[0095] Among the above, R in formula (4) or formula (5) ４is preferably a linear or branched alkyl group having 3 to 12 carbon atoms, and a linear or branched alkenyl group having 3 to 6 carbon atoms. By containing such a group, a liquid compound having an appropriate viscosity is easily obtained, and the curing performance of the compound tends to be further improved. From the viewpoint of curing temperature control or viscosity control, it is preferable that compound (D-1) contains a plurality of compounds represented by formula (4), formula (5), or formula (6). It is also possible to contain a plurality of compounds having different structures represented by the same formula.

[0096] In particular, from the viewpoint of viscosity control, compound (D-1) preferably contains compounds represented by formula (4) and formula (6). When a plurality of compounds represented by formula (4), (5), or (6) are contained, the content ratio of the compound represented by formula (4) is preferably 0.1% by mass to 99.5% by mass relative to the total amount of the compounds represented by formula (4), (5), or (6). This makes it possible to easily control the viscosity. A composition containing a plurality of compounds represented by formula (4), (5), or (6) can be obtained by mixing the plurality of compounds, or by simultaneously producing the plurality of compounds in the compound production method described below.

[0097] The compound represented by formula (4), formula (5), or formula (6) can be produced, for example, by reacting an ester compound, a hydrazine compound, and a glycidyl ether compound, although this is not limited thereto.

[0098] The ester compound is not particularly limited, but examples thereof include monocarboxylic acid ester compounds and dicarboxylic acid ester compounds.

[0099] Specific examples of monocarboxylic acid ester compounds include methyl lactate, ethyl lactate, methyl mandelate, methyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl valerate, methyl isovalerate, methyl pivalate, methyl heptanoate, methyl octanoate, methyl acrylate, methyl methacrylate, methyl crotonate, methyl isocrotonate, methyl benzoylformate, 2-methoxybenzoylmethyl, 3-methoxybenzoylmethyl, 4-methoxybenzoylmethyl, 2-ethoxybenzoylmethyl, 4-t-butoxybenzoylmethyl, etc. Alternatively, ethyl esters, propyl esters, etc. may be used.

[0100] Specific examples of dicarboxylic acid ester compounds include dimethyl oxalate, dimethyl malonate, dimethyl succinate, dimethyl tartrate, dimethyl glutarate, dimethyl adipate, dimethyl pimelate, dimethyl suberate, dimethyl azelaate, dimethyl sebacate, dimethyl maleate, dimethyl fumarate, dimethyl itaconate, dimethyl phthalate, dimethyl isophthalate, dimethyl terephthalate, dimethyl 1,3-acetonedicarboxylate, and diethyl 1,3-acetonedicarboxylate. Alternatively, cyclic esters may be used. Specific examples of cyclic esters include α-acetolactone, β-propionolactone, γ-butyrolactone, δ-valerolactone, γ-valerolactone, and ε-caprolactone. Alternatively, diethyl esters, dipropyl esters, and the like may be used.

[0101] Among these, from the viewpoint of curability and liquefaction, the ester compound is preferably ethyl lactate, methyl mandelate, methyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl valerate, methyl isovalerate, methyl pivalate, methyl acrylate, methyl methacrylate, methyl crotonate, methyl isocrotonate, methyl benzoylformate, dimethyl oxalate, dimethyl malonate, dimethyl succinate, dimethyl tartrate, dimethyl glutarate, dimethyl adipate, dimethyl pimelate, dimethyl suberate, dimethyl azelaate, dimethyl maleate, dimethyl fumarate, dimethyl phthalate, dimethyl isophthalate, dimethyl terephthalate, dimethyl 1,3-acetonedicarboxylate, diethyl 1,3-acetonedicarboxylate, γ-butyrolactone, δ-valerolactone, or γ-valerolactone.

[0102] The hydrazine compound is not particularly limited, but examples thereof include dimethylhydrazine, diethylhydrazine, methylethylhydrazine, methylpropylhydrazine, methylbutylhydrazine, methylpentylhydrazine, methylhexylhydrazine, ethylpropylhydrazine, ethylbutylhydrazine, ethylpentylhydrazine, ethylhexylhydrazine, dipropylhydrazine, dibutylhydrazine, dipentylhydrazine, dihexylhydrazine, methylphenylhydrazine, ethylphenylhydrazine, methyltolylhydrazine, ethyltolylhydrazine, diphenylhydrazine, benzylphenylhydrazine, dibenzylhydrazine, dinitrophenylhydrazine, 1-aminopiperidine, N-aminohomopiperidine, 1-amino-2,6-dimethylpiperidine, 1-aminopyrrolidine, 1-amino-2-methylpyrrolidine, 1-amino-2-phenylpyrrolidine, and 1-aminomorpholine. Among these, from the viewpoints of curability and liquefaction, dimethylhydrazine, dibenzylhydrazine, 1-aminopiperidine, 1-aminopyrrolidine, and 1-aminomorpholine are preferred as the hydrazine compound. Furthermore, among these, from the viewpoints of availability and safety, dibenzylhydrazine and 1-aminopiperidine are more preferred. The hydrazine compounds may be used alone or in combination of two or more.

[0103] The glycidyl ether compound is not particularly limited, but for example, a monofunctional monoglycidyl ether compound, a bifunctional or higher functional polyglycidyl ether compound, or the like can be used.

[0104] Specific examples of the monoglycidyl ether compound include methyl glycidyl ether, ethyl glycidyl ether, n-butyl glycidyl ether, t-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, dodecyl glycidyl ether, higher alcohol glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, orthophenylphenol glycidyl ether, benzyl glycidyl ether, biphenylyl glycidyl ether, 4-t-butylphenyl glycidyl ether, t-butyldimethylsilyl glycidyl ether, and 3-[diethoxy(methyl)silyl]propyl glycidyl ether.

[0105] Specific examples of polyglycidyl ether compounds include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, butanediol glycidyl ether, hexanediol glycidyl ether, trimethylolpropane polyglycidyl ether, and glycerin polyglycidyl ether. alicyclic polyglycidyl ether compounds such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, ethylene oxide-added bisphenol A diglycidyl ether, propylene oxide-added bisphenol A diglycidyl ether, and hydrogenated condensates thereof; and aromatic polyglycidyl ether compounds such as resorcinol diglycidyl ether.

[0106] Among these, from the viewpoint of curability and liquefaction, preferred glycidyl ether compounds include methyl glycidyl ether, ethyl glycidyl ether, n-butyl glycidyl ether, t-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, t-butyldimethylsilyl glycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, butanediol glycidyl ether, hexanediol glycidyl ether, trimethylolpropane polyglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, ethylene oxide adduct bisphenol A diglycidyl ether, propylene oxide adduct bisphenol A diglycidyl ether, polyethylene glycol diglycidyl ether, and 1-phenoxy-1,4-(oxiranylmethoxy)-3,6,9,12-tetraoxatetradecane.

[0107] Furthermore, from the viewpoint of adhesiveness, epoxy resins having an ether structure are preferred. Specific examples include polyethylene glycol diglycidyl ether and 1-phenoxy-1,4-(oxiranylmethoxy)-3,6,9,12-tetraoxatetradecane. The glycidyl ether compounds may be used alone or in combination of two or more.

[0108] The amounts of the ester compound, hydrazine compound, and glycidyl ether compound added to the reaction system can be set based on the molar ratio of the functional groups. The amount of the ester group of the ester compound is preferably 0.8 mol to 3.0 mol, more preferably 0.9 mol to 2.8 mol, and even more preferably 0.95 mol to 2.5 mol, relative to 1 mol of the primary amine of the hydrazine compound. The amount of the glycidyl group of the glycidyl ether compound is preferably 0.8 mol to 2.0 mol, more preferably 0.9 mol to 1.5 mol, and even more preferably 0.95 mol to 1.4 mol, relative to 1 mol of the primary amine of the hydrazine compound.

[0109] By controlling the amount of glycidyl groups in the glycidyl ether compound added relative to 1 mole of the primary amine in the hydrazine compound, compositions containing the compounds represented by formula (5) and formula (4) can be simultaneously produced. Specifically, the amount of glycidyl groups in the glycidyl ether compound is preferably 0.1 mol to 3.0 mol, more preferably 0.3 mol to 2.0 mol, and even more preferably 0.5 mol to 1.0 mol, relative to 1 mole of the primary amine in the hydrazine compound. In the above-mentioned methods for producing the compounds and compositions, a solvent may be used from the viewpoint of uniformly progressing the reaction.

[0110] The solvent is not particularly limited, but examples thereof include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, butanol, and t-butyl alcohol; and ethers such as tetrahydrofuran and diethyl ether.

[0111] The reaction temperature is preferably 10 to 100° C., more preferably 40 to 90° C. When the reaction temperature is 10° C. or higher, the reaction proceeds quickly, and the purity of the resulting compound tends to be improved. Furthermore, when the reaction temperature is 90° C. or lower, the polymerization reaction between glycidyl ether compounds can be efficiently suppressed, and the purity of the compound tends to be improved.

[0112] The reaction time is preferably 1 hour or more and 168 hours or less, more preferably 1 hour or more and 96 hours or more, and even more preferably 1 hour or more and 48 hours or less. After completion of the reaction, the obtained reaction product can be purified by known purification methods such as washing, extraction, recrystallization, column chromatography, etc. For example, the reaction solution dissolved in an organic solvent is washed with water, and then the organic layer is heated under normal pressure or reduced pressure to remove unreacted raw materials and the organic solvent from the reaction solution, and the target compound can be recovered. The target compound can also be recovered by purification using column chromatography. The solvent used for the above-mentioned washing is not particularly limited as long as it can dissolve the residual raw materials, but 1-hexane, 1-pentane, and cyclohexane are preferred from the viewpoints of yield, purity, and ease of removal.

[0113] The organic solvent used in the extraction is not particularly limited as long as it can dissolve the target compound. From the viewpoints of yield, purity, and ease of removal, however, ethyl acetate, dichloromethane, chloroform, carbon tetrachloride, toluene, diethyl ether, and methyl isobutyl ketone are preferred, and ethyl acetate, chloroform, toluene, and methyl isobutyl ketone are more preferred.

[0114] The packing material used in column chromatography may be a known one such as alumina, silica gel, etc. The developing solvent may be a known one such as ethyl acetate, dichloromethane, chloroform, carbon tetrachloride, tetrahydrofuran, diethyl ether, acetone, methyl isobutyl ketone, acetonitrile, methanol, ethanol, isopropanol, etc., which may be used alone or in combination.

[0115] In the epoxy resin curing agent of this embodiment, it is preferable that n in formula (5) and formula (6) of compound (D-1) is 2 or 3. This improves the crosslink density during curing, making it possible to prepare a tough cured product with improved adhesiveness and reliability.

[0116] (Imidazole Compound (D-2)) The imidazole compound (D-2) can be used without any particular limitation. Examples of the imidazole compound (D-2) include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecyl-imidazole trimellitate, imidazolyl succinic acid, 2-methylimidazole succinic acid, 2-ethylimidazole succinic acid, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, and 1-cyanoethyl-2-phenylimidazole.

[0117] From the viewpoint of penetrability, the epoxy resin composition of this embodiment has a viscosity at 25°C of preferably 50 Pa s or less, more preferably 40 Pa s or less, and even more preferably 20 Pa s or less. From the viewpoint of curability, the epoxy resin composition of this embodiment has a viscosity at 25°C of preferably 0.1 Pa s or more, more preferably 1 Pa s or more, and even more preferably 2 Pa s or more.

[0118] The viscosity (Pa s) of the epoxy resin composition at 25°C is obtained by dropping the epoxy resin composition into a measuring cup and measuring the viscosity with an E-type viscometer (for example, "TV-20" manufactured by Toki Sangyo Co., Ltd.) 5 minutes after the sample temperature reaches 25°C (cone No. 5, 3° R=12 mm).

[0119] The epoxy resin composition of the present embodiment preferably has a viscosity of 0.01 Pa s to 1.50 Pa s, more preferably 0.01 Pa s to 1.0 Pa s, and even more preferably 0.01 Pa s to 0.5 Pa s after being left at 110°C for 60 minutes. The viscosity after being left at 110°C for 60 minutes is measured using a rheometer (for example, a HAAKE MARS manufactured by Thermo Scientific).

[0120] The epoxy resin composition of this embodiment preferably exhibits a viscosity increase rate of 1.0 to 40.0 times, more preferably 1.0 to 30 times, and even more preferably 1.0 to 20 times, after being left at 110°C for 60 minutes. The viscosity increase rate after being left at 110°C for 60 minutes is measured using a rheometer (HAAKE MARS, manufactured by Thermo Scientific) by dropping the epoxy resin composition onto a measurement plate and measuring it 5 minutes and 60 minutes after the sample temperature reaches 110°C (aluminum cone plate, R = 20 mm, shear rate 20 ( / sec)). The viscosity after 5 minutes is defined as "η1" and the viscosity after 60 minutes is defined as "η2", and the viscosity increase rate is calculated by η2 / η1.

[0121] The epoxy resin composition of the present embodiment preferably has a reactivity when cured at 165°C of 70% or more and 100% or less, more preferably 80% or more and 100% or less, and even more preferably 90% or more and 100% or less.

[0122] The reaction rate when an epoxy resin composition is cured at 165°C is determined by using an EXSTER6000 (Hitachi High-Tech Science Corporation) to raise the temperature from 25°C to 300°C at a rate of 5°C / min, and calculating the total amount of heat generated in the temperature range from 100°C to 250°C. Furthermore, similar measurements may be taken after placing the composition in a small high-temperature chamber (manufactured by Espec Corporation) at 180°C for 2 hours, and the change in heat generated in the same temperature range may be calculated as a percentage. Furthermore, similar measurements may be taken after placing the composition in a small high-temperature chamber (manufactured by Espec Corporation) at 165°C for 2 hours, and the change in heat generated in the same temperature range may be calculated as a percentage. The calculation formula is as follows: Initial heat generation amount A: DSC peak heat generation amount of the composition; Post-curing heat generation amount B: DSC peak heat generation amount of the composition after heating; Reaction rate (%) = 100 × (Initial heat generation amount A - Post-curing heat generation amount B) ÷ Initial heat generation amount A

[0123] The epoxy resin composition and cured product of this embodiment are useful as adhesives, encapsulants, fillers, insulating materials, conductive materials, anisotropic conductive materials, sealing materials, prepregs, etc. As adhesives, they are useful as liquid adhesives, film adhesives, die bonding materials, etc. As encapsulants, they are useful as solid encapsulants, liquid encapsulants, film encapsulants, etc., and as liquid encapsulants, they are useful as underfill materials, potting materials, dam materials, etc. As insulating materials, they are useful as insulating adhesive films, insulating adhesive pastes, solder resists, etc.; as conductive materials, they are useful as conductive films, conductive pastes, etc.; and as anisotropic conductive materials, they are useful as anisotropic conductive films, anisotropic conductive pastes, etc.

[0124] <<Adhesive>> The epoxy resin composition of the present embodiment can be suitably used as an adhesive. The adhesive of the present embodiment contains the epoxy resin composition of the present embodiment.

[0125] <<Cured Product>> The cured product of this embodiment is a cured product of the epoxy resin composition of this embodiment. The cured product of this embodiment can be suitably used as a sealant, and the sealant is preferably a semiconductor sealant. The sealant of this embodiment includes the cured product of this embodiment.

[0126] Furthermore, the cured product of this embodiment can be suitably used as a semiconductor package. The semiconductor package of this embodiment includes the cured product of this embodiment. The method for producing a semiconductor package of this embodiment includes a step of producing a semiconductor package using the epoxy resin composition of this embodiment. The step of producing a semiconductor package using the epoxy resin composition of this embodiment may include a step of preparing the epoxy resin composition of this embodiment. The epoxy resin composition of this embodiment may be obtained, for example, by stirring and mixing the components contained in the epoxy resin composition of this embodiment in a planetary centrifugal mixer (e.g., "ARE-310" manufactured by Thinky Corporation) and then kneading with a three-roll mill.

[0127] The process for producing a semiconductor package using the epoxy resin composition of the present embodiment may be a process for producing a semiconductor package by appropriately molding a prepared epoxy resin composition and heating it at a predetermined temperature for a predetermined time to cure it.

[0128] Hereinafter, the present embodiment will be described with reference to specific examples and comparative examples, but the present invention is not limited to the following examples and comparative examples. That is, a person skilled in the art can practice the present invention by making various modifications to the examples shown below. In the following, unless otherwise specified, "parts" are based on mass.

[0129] [Analysis of Components in Epoxy Resin Curing Agent] Analysis was carried out by the method described in the above section [Analysis of Components in Epoxy Resin Curing Agent].

[0130] [Method for measuring glass transition temperature (Tg) and melting point (Tm) of epoxy resin curing agent] The glass transition temperature (Tg) and melting point (Tm) of the epoxy resin curing agent were measured using a differential scanning calorimeter (TA Instruments-Waters, differential scanning calorimetry system, "DSC Q2000") under a nitrogen gas flow (40 mL / min) by heating a 10 mg sample from -50°C to 200°C at a heating rate of 5°C / min. The Tm of the amine adduct was taken as the apex temperature of the endothermic peak in the DSC curve (JIS K7121-1987), and the Tg was taken as the peak top temperature of the DSC differential curve (Reference: JIS K6240). The obtained Tg and Tm were evaluated according to the following evaluation criteria. [Evaluation criteria for Tg] A: Tg was less than -20°C. B: Tg was -20°C or higher and less than 0°C. C: Tg was 0°C or higher and lower than 20°C. D: Tg was 20°C or higher. [Evaluation criteria for Tm] A: No clear peak top temperature was observed. B: Tm was -20°C or higher and lower than 20°C. C: Tm was 20°C or higher and lower than 60°C. D: Tm was 60°C or higher.

[0131] [Method for measuring viscosity of epoxy resin composition at 25°C] The viscosity (Pa s) of the epoxy resin composition at 25°C was measured using an E-type viscometer (TV-20, manufactured by Toki Sangyo Co., Ltd.) 5 minutes after the resin composition (0.3 mL) was dropped into a measuring cup and the sample temperature reached 25°C (cone No. 5, 3°, R=12 mm). The obtained viscosity was evaluated according to the following evaluation criteria. [Evaluation criteria] A: The viscosity at 25°C was less than 10 Pa s. B: The viscosity at 25°C was 10 Pa s or more and less than 50 Pa s. C: The viscosity at 25°C was 50 Pa s or more and less than 100 Pa s. D: The viscosity at 25°C was 100 Pa s or more.

[0132] [Method for measuring viscosity of epoxy resin composition at 110°C] The viscosity (Pa s) of the epoxy resin composition at 110°C was measured by dropping 0.2 mL of the resin composition onto a measurement plate, and 5 minutes after the sample temperature reached 110°C, using a rheometer (HAAKE MARS, manufactured by Thermo Scientific) at a constant measurement temperature (110°C) in oscillation mode (f = 1 Hz) (aluminum cone plate R = 20 mm, shear rate 20 ( / sec)). The obtained viscosity was evaluated according to the following evaluation criteria. [Evaluation criteria] A: The viscosity at 110°C was less than 0.10 Pa s. B: The viscosity at 110°C was 0.10 Pa s or more and less than 0.20 Pa s. C: The viscosity at 110°C was 0.20 or more and less than 0.50 Pa s. D: Viscosity at 110°C was 0.50 or more.

[0133] [Method for Evaluating Viscosity Stability at 110°C (High Temperature)] The viscosity stability of the epoxy resin composition at 110°C was evaluated by dropping 0.2 mL of the resin composition onto a measurement plate. Five minutes and 60 minutes after the sample temperature reached 110°C, the viscosity was measured using a rheometer (HAAKE MARS, manufactured by Thermo Scientific) at a constant measurement temperature (110°C) in oscillation mode (f = 1 Hz) (aluminum cone plate R = 20 mm, shear rate 20 ( / sec)). The viscosity after 5 minutes was designated "η1" and the viscosity after 60 minutes was designated "η2", and the value calculated as η2 / η1 was determined as the viscosity increase ratio. The obtained viscosity increase ratio was evaluated according to the following evaluation criteria. The lower the viscosity increase ratio, the better the storage stability. [Evaluation Criteria] A: The viscosity increase ratio was less than 3.0 times. B: The viscosity increase ratio was 3.0 times or more but less than 10.0 times. C: The viscosity increase rate was 10.0 times or more and less than 40.0 times. D: The viscosity increase rate was 10.0 times or more.

[0134] [Evaluation of Flow Properties] A test specimen was prepared by fixing a glass plate instead of a semiconductor element on a glass substrate (26 mm wide x 75 mm long) with a gap of 25 μm. Next, this test specimen was placed on a hot plate set to 110° C., and an epoxy resin composition was applied to one end of the glass plate. The time (seconds) required for the resin to pass through the gap and reach a point 20 mm from the gap was measured. The obtained time was evaluated according to the following evaluation criteria. The better the flow properties, the better the penetration properties. [Evaluation Criteria] A: The arrival time was less than 80 seconds. B: The arrival time was 80 seconds or more but less than 120 seconds. C: The arrival time was 120 seconds or more but less than 200 seconds. D: The arrival time was 200 seconds or more.

[0135] [Method for Measuring Tg of Cured Product] An epoxy resin composition was cured at 180°C or 165°C for 2 hours to prepare a test specimen (2 mm thick x 20 mm long x 10 mm wide). The test specimen was measured using a thermomechanical analyzer (RSA-G2, manufactured by TA Instruments Japan Co., Ltd.) under conditions of a load of 0.5 N, a measurement temperature of 0°C to 250°C, and a temperature rise rate of 5°C / min, and the peak top temperature of Tan δ was taken as Tg. The obtained Tg was evaluated according to the following evaluation criteria. [Evaluation Criteria] A: Tg was 120°C or higher. B: Tg was less than 120°C and 100°C or higher. C: Tg was less than 100°C and 80°C or higher. D: Tg was less than 80°C.

[0136] [Reaction Rate When Cured at 180°C or 165°C] The reaction rate when the epoxy resin composition was cured at 180°C or 165°C was measured by the following method. Using an EXSTER6000 (Hitachi High-Tech Science Corporation), the temperature was raised from 25°C to 300°C at a rate of 5°C / min, and the total amount of heat generated in the temperature range from 100°C to 250°C was calculated. Furthermore, for Examples 1-1 to 1-11 and Comparative Example 1-1, measurements were similarly taken after placing the samples in a small high-temperature chamber (manufactured by Espec Corporation) at 180°C for 2 hours, and the change in heat generated in the same temperature range was calculated as a percentage. Furthermore, for Examples 1-12 to 1-14, measurements were similarly taken after placing the samples in a small high-temperature chamber (manufactured by Espec Corporation) at 165°C for 2 hours, and the change in heat generated in the same temperature range was calculated as a percentage. The calculation formula is as follows: Initial heat release A: DSC peak heat release of the compound Post-cure heat release B: DSC peak heat release of the compound after heating Reaction rate (%) = 100 x (initial heat release A - post-cure heat release B) / initial heat release A The obtained reaction rate was evaluated according to the following evaluation criteria. [Evaluation criteria] A: The reaction rate was 90% or more. B: The reaction rate was less than 90% and 80% or more. C: The reaction rate was less than 80% and 70% or more. D: The reaction rate was less than 70%.

[0137] The abbreviations for the components in this example have the following meanings: (Aromatic amines (A-1)) APAB: 4-aminophenyl-4'-aminobenzoate 44DAS: 4,4'-diaminodiphenyl sulfone 34ODA: 3,4'-diaminodiphenyl ether TPE-M: 1,3-bis(3-aminophenoxy)benzene Ethacure 300: curing agent containing diethylthiotoluenediamine (manufactured by Mitsui Fine Chemicals, Inc.) Ethacure 100 Plus (+): curing agent containing diethyltoluenediamine (manufactured by Mitsui Fine Chemicals, Inc.) Kayahard AA: curing agent containing 3,3'-diethyl-4,4'-jaminodiphenylmethane (manufactured by Nippon Kayaku Co., Ltd.)

[0138] (Reactive compounds) 2-EH: 2-ethylhexyl glycidyl ether BGE: butyl glycidyl ether ph-GE: phenyl glycidyl ether

[0139] (Epoxy resin) EXA-850CRP (manufactured by DIC Corporation) EXA-830CRP (manufactured by DIC Corporation) JER-630LSD (manufactured by Mitsubishi Chemical Corporation)

[0140] (Curing accelerator) 2P4MHZ-PW (manufactured by Shikoku Chemicals Corporation)

[0141] (Inorganic filler) SE203G-SEJ (manufactured by Admatechs Co., Ltd.)

[0142] <Preparation of Epoxy Resin Curing Agent> (Synthesis Example 1-1) After replacing the atmosphere in a 500 ml four-neck flask equipped with a reflux condenser and a stirring blade with nitrogen, 20 g of 1-butanol and 0.05 mol of 4,4'-diaminodiphenyl sulfone (44DAS) were added and the flask was heated to an internal temperature of 120°C. Then, using a dropping funnel, 0.03 mol of 2-ethylhexyl glycidyl ether (2-EH) was added dropwise over 30 minutes. After the dropwise addition was completed, the reaction solution was stirred while being heated at 120°C for 6 hours to complete the reaction. Using an evaporator, the 1-butanol was distilled off from the resulting solution over 2 hours while maintaining the temperature at 80°C and the pressure at 15 mmHg or less, yielding epoxy resin curing agent (A-1). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement. The results are shown in Table 2.

[0143] Synthesis Example 1-2: Synthesis and purification were carried out under the same conditions as in Synthesis Example 1-1, except that 0.03 mol of 2-ethylhexyl glycidyl ether (2-EH) was changed to 0.035 mol of butyl glycidyl ether (BGE), to obtain an epoxy resin curing agent (B). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement.

[0144] Synthesis Example 1-3 Synthesis and purification were carried out under the same conditions as in Synthesis Example 1-1, except that 4,4'-diaminodiphenyl sulfone (44DAS) was changed to 1,3-bis(3-aminophenoxy)benzene (TPE-M), to obtain an amine adduct (B). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement.

[0145] Synthesis Example 1-4: Synthesis and purification were carried out under the same conditions as in Synthesis Example 1-1, except that 4,4'-diaminodiphenyl sulfone (44DAS) was changed to 4-aminophenyl-4'-aminobenzoate (APAB) and the amount of 2-ethylhexyl glycidyl ether (2-EH) was changed from 0.03 mol to 0.04 mol, to obtain an amine adduct (C-1). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement.

[0146] Synthesis Example 1-5: Synthesis and purification were carried out under the same conditions as in Synthesis Example 1-4, except that 2-ethylhexyl glycidyl ether was changed to butyl glycidyl ether, to obtain an amine adduct (C-2). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement.

[0147] Synthesis Example 1-6 Synthesis and purification were carried out under the same conditions as in Synthesis Example 1-1, except that 4,4'-diaminodiphenyl sulfone (44DAS) was changed to 3,4'-oxydianiline (34ODA) and the amount of 2-ethylhexyl glycidyl ether (2-EH) was changed from 0.03 mol to 0.045 mol, to obtain an amine adduct (D). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement.

[0148] Synthesis Example 1-7: Synthesis and purification were carried out under the same conditions as in Synthesis Example 1-4, except that 4-aminophenyl-4'-aminobenzoate (APAB) was changed to Kayahard AA, to obtain an amine adduct (E-1). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement.

[0149] Synthesis Example 1-8: Synthesis and purification were carried out under the same conditions as in Synthesis Example 1-7, except that 2-ethylhexyl glycidyl ether (2-EH) was changed to phenyl glycidyl ether (ph-GE), to obtain an amine adduct (E-2). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement.

[0150] Synthesis Example 1-9: Synthesis and purification were carried out under the same conditions as in Synthesis Example 1-1, except that 4,4'-diaminodiphenyl sulfone (44DAS) was changed to Ethacure 100 Plus and the amount of 2-ethylhexyl glycidyl ether (2-EH) was changed from 0.03 mol to 0.025 mol, to obtain an amine adduct (F-1). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement.

[0151] Synthesis Example 1-10: Synthesis and purification were carried out under the same conditions as in Synthesis Example 1-9, except that 0.025 mol of 2-ethylhexyl glycidyl ether (2-EH) was changed to 0.035 mol of phenyl glycidyl ether (ph-GE), to obtain an amine adduct (F-2). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement.

[0152] Synthesis Example 1-11 Synthesis and purification were carried out under the same conditions as in Synthesis Example 1-1, except that 4,4'-diaminodiphenyl sulfone (44DAS) was changed to Ethacure 300, to obtain an amine adduct (G). The ratios of aromatic amine (A-1), aromatic amine adduct (A-2-1), and aromatic amine adduct (A-2-2X) contained in the obtained epoxy resin curing agent were determined by LC / MS measurement.

[0153]

[0154] <Preparation of Epoxy Resin Composition> (Synthesis of Compound (Mixture Containing D-1A and D-1B)) 7.20 g (0.07 mol) of ethyl propionate, 13.17 g (0.0245 mol) of Denacol EX-830, and 1.67 g (0.0105 mol) of EX-830CRP were weighed into a recovery flask, and the flask was heated in an oil bath to 90°C. Next, 6.00 g (0.06 mol) of 1-aminopiperidine was added dropwise over 15 minutes. After completion of the dropwise addition, the mixture was stirred for 4 hours while maintaining the temperature at 90°C, and the reaction was completed. The resulting reaction solution was concentrated under reduced pressure at 80°C to remove the by-product alcohol and unreacted raw materials, yielding Compound A [mixture containing compounds (D-1A) and (D-1B)] as a liquid product. The structures of compounds (D-1A) and (D-1B) are as follows:

[0155]

[0156] (Synthesis of Compound (D-1C)) 3.93 g (0.038 mol) of ethyl propionate and 5.00 g (0.038 mol) of butyl glycidyl ether were weighed into a recovery flask, and the flask was heated in an oil bath to 90°C. Next, 3.85 g (0.038 mol) of 1-aminopiperidine was added dropwise over 15 minutes. After completion of the addition, the mixture was stirred for 4 hours while maintaining the temperature at 90°C, and the reaction was completed. The resulting reaction solution was concentrated under reduced pressure at 80°C to remove the by-product alcohol and unreacted raw materials, yielding Compound (D-1C) as a liquid product. The structure of Compound (D-1C) is shown below.

[0157]

[0158] (Synthesis of Compound (D-1D)) 1.94 g (0.019 mol) of ethyl propionate and 5.00 g (0.009 mol) of polyethylene glycol diglycidyl ether were weighed into a recovery flask, and the flask was heated in an oil bath to 90°C. Next, 1.62 g (0.016 mol) of 1-aminopiperidine was added dropwise over 15 minutes. After completion of the addition, the mixture was stirred for 4 hours while maintaining the temperature at 90°C, and the reaction was completed. The resulting reaction solution was concentrated under reduced pressure at 80°C to remove the by-product alcohol and unreacted raw materials, yielding Compound (D-1D) as a liquid product. The structure of Compound (D-1D) is shown below.

[0159]

[0160] (Examples 1-1 to 1-11, Comparative Example 1-1) Each of the components shown in Table 3 or 4 was placed in a plastic stirring vessel in the amount shown in Table 3 or 4, and the mixture was stirred and mixed using a planetary centrifugal mixer ("ARE-310" manufactured by Thinky Corporation), followed by kneading using a three-roll mill to prepare an epoxy resin composition. The resulting epoxy resin composition was poured into a Teflon (registered trademark) metal frame and heated at 180°C for 2 hours to produce a cured product. The Tg of the resulting cured product was evaluated.

[0161] (Examples 1-12 to 1-16) Each of the components shown in Table 3 or 4 was placed in a plastic stirring vessel in the amount shown in Table 3 or 4, and the mixture was stirred and mixed using a planetary centrifugal mixer ("ARE-310" manufactured by Thinky Corporation), followed by kneading using a three-roll mill to prepare an epoxy resin composition. The resulting epoxy resin composition was poured into a Teflon metal frame and heated at 165°C for 2 hours to produce a cured product. The Tg of the resulting cured product was evaluated.

[0162]

[0163]

[0164] As shown in Tables 3 and 4, examples using epoxy resin curing agents containing an aromatic amine compound (A-1), an aromatic amine adduct (A-2) which is a reaction product of the aromatic amine compound and a reactive compound having a functional group reactive with the aromatic amine compound, and an aromatic amine adduct (A-2-1) in which one molecule of the reactive compound is added to one molecule of the aromatic amine compound (A-1), and the ratio (A-1 / A-2-1) of the aromatic amine compound to the aromatic amine adduct (A-2-1) obtained by liquid chromatography analysis (UV detector) was 0.50 to 2.00, showed excellent flowability and therefore excellent penetration. Furthermore, the examples were able to obtain cured products and also had excellent viscosity stability. Therefore, the epoxy resin curing agents of the examples were able to achieve both curability and storage stability. Furthermore, the epoxy resin compositions described in Examples 1-2, 1-4 to 1-8, and 1-9 use an amine adduct in which the ratio (A-1 / A-2-1) of the aromatic amine compound to the aromatic amine adduct (A-2-1) is 0.50 to 1.10, and therefore exhibit particularly excellent flow properties and therefore excellent penetration properties. Furthermore, the epoxy resin compositions described in Examples 1-1, 1-3, 1-9, and 1-10 use an amine adduct in which the ratio (A-1 / A-2-1) of the aromatic amine compound to the aromatic amine adduct (A-2-1) is 1.20 to 2.00, and therefore exhibit particularly excellent reactivity and therefore excellent heat resistance. Comparative Example 1-1, which did not use the aromatic amine adduct (A-2), which is the reaction product of the aromatic amine compound (A-1) and a reactive compound, exhibited poor flow properties and therefore poor penetration properties. The reason for this is presumably that the epoxy resin composition described in Comparative Example 1-1 did not contain the aromatic amine adduct (A-2), and therefore had poor viscosity stability.

[0165] Furthermore, it was confirmed that the epoxy resin compositions described in Examples 1-12 to 1-16 had sufficient curability even when the temperature was lowered from 180° C. to 165° C. by adding a curing catalyst to compensate for the reactivity of the amine adduct. The epoxy resin compositions of the examples can be suitably used as encapsulants, particularly as underfill materials used for encapsulating semiconductor chips and the like.

[0166] When an epoxy resin curing agent with a high glass transition temperature (Tg) (e.g., 20°C or higher) is used, the flowability is poor and therefore the penetration is poor. In the above cases, the Tg and Tm of the epoxy resin curing agent are relatively high, resulting in poor viscosity when the epoxy resin composition is formed, and as a result, poor flowability. When an epoxy resin curing agent with a high glass transition temperature (Tg) is used, the viscosity stability is excellent but the curing ability is poor, and the Tg of the cured product may be low. The reason for this is thought to be that the use of an amine having an electron-withdrawing group as the aromatic amine compound reduces reactivity and compatibility with the epoxy resin. Furthermore, when an epoxy resin curing agent with a high glass transition temperature (Tg) is used, the viscosity of the epoxy resin composition is low, but the viscosity stability is poor and the flowability may be reduced. This is because the reactivity of the aromatic amine compound used is too high.

[0167] The epoxy resin curing agent obtained in Example 2, in which the aromatic amine adduct (A-2), which is the reaction product of an aromatic amine compound and a reactive compound having a functional group capable of reacting with the aromatic amine compound (A-1), is used, has a molecular weight of less than 150. As a result, the Tg of the curing agent is high, and the fluidity of the curing agent decreases after long-term storage at room temperature for about one month, leaving room for further improvement in terms of handleability when kneaded with an epoxy resin. On the other hand, the epoxy resin curing agent using the reactive compound having a molecular weight greater than 150 has a low Tg, remains fluid even after long-term storage at room temperature for about one month, and is therefore easy to handle when kneaded with an epoxy resin.

[0168] The disclosure of Japanese Patent Application No. 2023-125549, filed on August 1, 2023, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. An epoxy resin curing agent comprising: an aromatic amine compound (A-1); and an aromatic amine adduct (A-2) which is a reaction product between the aromatic amine compound and a reactive compound having a functional group capable of reacting with the aromatic amine compound, wherein the aromatic amine adduct (A-2) comprises an aromatic amine adduct (A-2-1) in which one molecule of the reactive compound is added to one molecule of the aromatic amine compound (A-1), and the ratio (A-1 / A-2-1) of the aromatic amine compound to the aromatic amine adduct (A-2-1) obtained by liquid chromatography analysis (UV detector) is 0.50 to 2.

00.

2. The epoxy resin curing agent according to claim 1, which has a glass transition temperature (Tg) of 20°C or lower as detected by differential scanning calorimetry (DSC) at a heating rate of 5°C / min.

3. The epoxy resin curing agent according to claim 1, which has no melting point (Tm) detected in the range of -20°C to 60°C in differential scanning calorimetry (DSC) measured in the temperature range of -50°C to 200°C at a heating rate of 5°C / min.

4. The epoxy resin curing agent according to claim 1, wherein in the aromatic amine adduct (A-2), a reaction ratio between the aromatic amine compound and the reactive compound (aromatic amine compound / reactive compound) is 1 / 0.95 to 1 / 0.40 on a substance amount basis.

5. The epoxy resin curing agent according to claim 1, wherein the aromatic amine compound (A-1) is an aromatic amine compound represented by the following formula (1) or (2): In formula (1), R １ and R ２ each independently represents a monovalent organic group having 1 to 20 carbon atoms or a halogen; a and b each independently represent an integer of 0 to 4; and X represents a divalent organic group or a single bond. In formula (2), R ３ represents a monovalent organic group having 1 to 20 carbon atoms or a halogen; and c is an integer of 1 to 4.

6. The hardener for epoxy resins according to claim 1, wherein the molecular weight of the reactive compound is greater than 150.

7. The epoxy resin curing agent according to claim 1, wherein the molecular weight ratio of said reactive compound to said aromatic amine compound is 0.5 or more and 1.1 or less.

8. The epoxy resin curing agent according to claim 1, wherein the reactive compound is an epoxy compound having one glycidyl group in the molecule.

9. An epoxy resin composition comprising the epoxy resin curing agent according to claim 1, an epoxy resin (B), and an inorganic filler (C).

10. The epoxy resin composition according to claim 9, further comprising a curing accelerator (D).

11. The epoxy resin composition according to claim 10, wherein the curing accelerator is at least one selected from the group consisting of a compound (D-1) represented by the following formula (4), (5), or (6), and an imidazole-based compound (D-2): (In formulas (4) to (6), R １ each independently represents a hydrogen atom or an n-valent organic group having 1 to 15 carbon atoms which may have a hydroxyl group, a carbonyl group, an ester bond or an ether bond; R ２ and R ３ each independently represents an unsubstituted or substituted alkyl group, aryl group, or aralkyl group having 1 to 12 carbon atoms, or combines to form a heterocycle having 7 or less carbon atoms; R ４ R each independently represents a hydrogen atom or an n-valent organic group having 1 to 50 carbon atoms which may contain an oxygen atom; n represents an integer of 1 to 3. ５ represents a negatively charged nitrogen atom, R ６ represents a positively charged nitrogen atom.) 12. The epoxy resin composition according to claim 9, wherein the content of the inorganic filler (C) is 50% by mass to 70% by mass based on the total amount of the epoxy resin composition.

13. The epoxy resin composition according to claim 9, which has a viscosity of 0.01 Pa·s to 1.50 Pa·s after standing at 110° C. for 60 minutes.

14. A cured product of the epoxy resin composition according to claim 9.

15. A sealing material comprising the cured product according to claim 14.

16. The encapsulant according to claim 15, which is an encapsulant for semiconductors.

17. An adhesive comprising the epoxy resin composition of claim 9.

18. A semiconductor package comprising the cured product according to claim 14.

19. A method for producing a semiconductor package, comprising the step of producing a semiconductor package using the epoxy resin composition according to claim 9.

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