HK1118303B

HK1118303B - Latent hardener for epoxy resin and epoxy resin composition

Info

Publication number: HK1118303B
Application number: HK08109321.3A
Authority: HK
Inventors: Hisanao Yamamoto; Kazuhiro Daikai
Original assignee: 旭化成株式会社
Priority date: 2005-02-23
Filing date: 2006-02-23
Publication date: 2011-08-12

Description

Latent curing agent for epoxy resin and epoxy resin composition

Technical Field

The present invention relates to a novel latent curing agent for epoxy resins and a one-component epoxy resin composition using the same. More specifically, the present invention relates to a latent curing agent for an epoxy resin composition which can provide a composition having high curability, high latent property, and excellent storage stability (storage stability), solvent resistance, and moisture resistance, and a one-pack epoxy resin composition using the same.

Background

Cured products of epoxy resins have excellent properties in mechanical properties, electrical properties, thermal properties, chemical resistance, adhesion, and the like, and thus are widely used in a wide range of applications such as paints, insulating materials for electric and electronic devices, and adhesives. The epoxy resin composition generally used at present is a so-called two-component epoxy resin composition in which two components of an epoxy resin and a curing agent are mixed at the time of use.

The two-component epoxy resin composition can be cured at room temperature, and on the other hand, it is necessary to store the epoxy resin and the curing agent separately, and to measure and mix the epoxy resin and the curing agent as necessary, and then to use them, which is troublesome to store and handle.

Further, since the usable time is limited, a large amount of the components cannot be mixed in advance, and the mixing frequency is increased, so that the efficiency is inevitably lowered.

In order to solve the problems of such two-component epoxy resin formulations, several one-component epoxy resin compositions have been proposed so far. For example, dicyandiamide or BF_3-A latent curing agent such as an amine complex, an amine salt, or a modified imidazole compound is blended with an epoxy resin.

However, among these latent curing agents, a curing agent having excellent storage stability has low curability and requires a high temperature or a long time for curing, while a curing agent having high curability has low storage stability and requires storage at a low temperature such as-20 ℃. For example, dicyandiamide has storage stability of 6 months or more when stored at room temperature, but requires a curing temperature of 170 ℃ or more, and when it is used in combination with a curing accelerator in order to lower the curing temperature, it can be cured at 130 ℃ for example, but storage stability at room temperature is insufficient, and it is necessary to store it at low temperature. Therefore, a composition having both high curability and excellent storage stability is strongly required. In addition, when a film-shaped molded product or a product in which a base material is impregnated with an epoxy resin is obtained, a formulation containing a solvent, a reactive diluent, and the like is often formed, and when a conventional latent curing agent is used as a curing agent for the formulation, storage stability is extremely lowered, and it is substantially necessary to prepare a two-component composition, and therefore, improvement is required.

In response to this demand, many studies have been made, and for example, patent documents 1, 2 and 3 describe curing agents for epoxy resins, the surfaces of which are coated with a reactant of an isocyanate compound.

However, in recent years, particularly in the field of electronic devices, in order to cope with the increase in circuit density and the improvement in connection reliability, and in order to use a material having low heat resistance for the weight reduction of mobile devices, or to greatly improve productivity, there has been a strong demand for a one-component epoxy resin composition used as one kind of connection material to further improve its rapid curing property, solvent resistance, curing agent dispersibility, and the like without impairing its storage stability, and it has been difficult to achieve this.

Patent document 1: japanese patent laid-open publication No. 61-190521

Patent document 2: japanese unexamined patent publication Hei 1-70523

Patent document 3: japanese unexamined patent publication No. 11-193344

Disclosure of Invention

The present invention aims to provide a one-pack epoxy resin composition which can achieve both high curability and storage stability, a latent curing agent used for obtaining the composition, and an adhesive material, a conductive material, an insulating material, a sealing material, a coating composition, a prepreg, a structural adhesive, a heat conductive material, and the like, which have high storage stability, solvent resistance, and moisture resistance, and can achieve high connection reliability, adhesive strength, and high sealing performance even under low-temperature or short-time curing conditions.

The present inventors have conducted intensive studies to solve the above problems and as a result, have found that a latent curing agent for epoxy resins coated with a film having a specific structure can satisfy the above object, and have completed the present invention.

Namely, the present invention is as follows.

1) A latent curing agent for epoxy resins, which comprises a curing agent (A) for epoxy resins and a resin coating the curing agent (A),

the resin coating the curing agent (a) for epoxy resin has a main chain structure composed of a structure (1)) having 2 nitrogen atoms, wherein linear or cyclic low molecular aliphatic hydrocarbon groups having no ester bond are present between the 2 nitrogen atoms, and at least one nitrogen atom of the structure (1) forms a urea bond.

2) The latent curing agent for epoxy resins according to 1) which comprises a curing agent (A) for epoxy resins and a resin coating the curing agent (A) for epoxy resins,

the resin coating the curing agent (a) for epoxy resin has a main chain structure composed of a structure (1)) having 2 nitrogen atoms, wherein a linear or cyclic low molecular aliphatic hydrocarbon group containing no oxygen atom other than an oxygen atom forming a urethane bond is present between the 2 nitrogen atoms, and at least one nitrogen atom of the structure (1) forms a urea bond.

3) The latent curing agent for epoxy resins according to 1) or 2), wherein the curing agent (A) for epoxy resins is coated with a film (c1) obtained by reacting an active hydrogen compound (b2) with an isocyanate component (b1) containing 1 to 95 mass% of a low-molecular 2-functional aliphatic isocyanate compound (c 1).

4) The latent curing agent for epoxy resins according to claim 3), wherein the isocyanate component (b1) comprises 1 to 95% by mass of a low-molecular 2-functional aliphatic isocyanate compound (b1-1) and 5 to 99% by mass of an aromatic isocyanate compound (b 1-2).

5) The latent curing agent for epoxy resins according to 3) or 4), wherein the film (c1) has an absorption wave number of 1630cm^-1～1680cm^-1Has a binding group (x) for infrared ray and an absorption wave number of 1680cm^-1～1725cm^-1The infrared binding group (y) of (2).

6) The latent curing agent for epoxy resins as described in any one of 1) to 5), wherein the curing agent (A) for epoxy resins comprises an amine-based curing agent comprising an amine adduct (a) and a low-molecular-weight amine compound (e) as main components.

7) The latent curing agent for epoxy resins according to claim 6), wherein the amine adduct (a) is obtained by reacting an epoxy resin (a1) and an amine compound (a 2).

8) The curing agent for epoxy resins according to 6) or 7), wherein the low-molecular amine compound (e) is an imidazole.

9) A microcapsule-type curing agent for epoxy resin, which comprises the curing agent for epoxy resin and/or the latent curing agent for epoxy resin according to any one of 1) to 8) as a core, is coated with a shell (C2) formed by the reaction of the curing agent (A) for epoxy resin and the epoxy resin (C), and has an absorption wave number of 1630cm at least on the surface^-1～1680cm^-1Has a binding group (x) for infrared ray and an absorption wave number of 1680cm^-1～1725cm^-1The infrared binding group (y) of (2).

10) A masterbatch-type curing agent composition for epoxy resin, which is characterized by comprising 10 to 50000 parts by weight of an epoxy resin (E) per 100 parts by weight of the latent curing agent for epoxy resin according to any one of 1) to 8) and/or the microcapsule-type curing agent for epoxy resin (D) according to 9).

11) A masterbatch-type curing agent composition for epoxy resin, characterized in that the total chlorine content of the masterbatch-type curing agent composition (F) in 10) is 2500ppm or less.

12) The curing agent composition for masterbatch-type epoxy resin according to 10) or 11), wherein the total chlorine content of the epoxy resin (E) is 2500ppm or less.

13) The hardener composition for masterbatch-type epoxy resins according to any one of claims 10) to 12), wherein the diol terminal impurity component of the epoxy resin (E) is 0.001 to 30% by mass of the basic component of the epoxy resin (E).

14) An epoxy resin composition comprising the latent curing agent for epoxy resins and/or the microcapsule-type curing agent (D) for epoxy resins and/or the masterbatch-type curing agent composition (F) for epoxy resins and the cyclic borate compound (L) according to any one of 1) to 13).

15) The epoxy resin composition as described in 14), wherein the cyclic borate compound (L) is 2, 2 '-oxybis (5, 5' -dimethyl-1, 3, 2-dioxaborane).

16) The epoxy resin composition according to 14) or 15), wherein the amount of the cyclic boric acid ester compound (L) according to 14) or 15) is 0.001 to 10 parts by mass based on 100 parts by mass of the total amount of the latent curing agent for epoxy resin and/or the microcapsule-type curing agent (D) for epoxy resin and/or the masterbatch-type curing agent composition (F) for epoxy resin according to any one of 1) to 13).

17) An epoxy resin composition comprising, as a main component, 0.001 to 1000 parts by mass of the latent curing agent for epoxy resins and/or the microcapsule-type curing agent for epoxy resins (D) and/or the masterbatch-type curing agent composition for epoxy resins (F) according to any one of 1) to 13) per 100 parts by mass of an epoxy resin (J).

18) An epoxy resin composition, characterized in that 0.001-10 parts by mass of a cyclic boric acid ester compound (L) is added to 100 parts by mass of the epoxy resin composition of 17).

19) The epoxy resin composition as described in 18), wherein the cyclic boric acid ester compound (L) is 2, 2 '-oxybis (5, 5' -dimethyl-1, 3, 2-dioxaborane).

20) An epoxy resin composition comprising 1 to 200 parts by mass of at least one curing agent (K) selected from the group consisting of acid anhydrides, phenols, hydrazides and guanidines, and 0.1 to 200 parts by mass of 1) to 13) of the latent curing agent for epoxy resins and/or the microcapsule-type curing agent (D) for epoxy resins and/or the masterbatch-type curing agent composition (F) for epoxy resins as a main component.

21) An epoxy resin composition, characterized in that 0.001-10 parts by mass of a cyclic borate ester compound (L) is added to 100 parts by mass of the epoxy resin composition of 20).

22) The epoxy resin composition as described in 21), wherein the cyclic borate compound (L) is 2, 2 '-oxybis (5, 5' -dimethyl-1, 3, 2-dioxaborane).

23) A paste composition characterized by containing the curing agent composition for a masterbatch-type epoxy resin and/or the epoxy resin composition described in any one of the above 10) to 22).

24) A film-like composition characterized by containing the hardener composition for masterbatch-type epoxy resin and/or the epoxy resin composition of any one of 10) to 22).

25) An adhesive comprising the epoxy resin composition according to any one of the above 14) to 22).

26) An adhesive paste characterized by containing the epoxy resin composition according to any one of the above 14) to 22).

27) An adhesive film characterized by containing the epoxy resin composition according to any one of the above 14) to 22).

28) An electrically conductive material, characterized by containing the epoxy resin composition of any one of the above 14) to 22).

29) An anisotropic conductive material, comprising the epoxy resin composition according to any one of the above 14) to 22).

30) An anisotropic conductive film, comprising the epoxy resin composition according to any one of the above 14) to 22).

31) An insulating material, characterized by containing the epoxy resin composition according to any one of the above 14) to 22).

32) A sealing material characterized by containing the epoxy resin composition according to any one of the above 14) to 22).

33) A coating material, characterized by containing the epoxy resin composition according to any one of the above 14) to 22).

34) A coating composition characterized by containing the epoxy resin composition according to any one of the above 14) to 22).

35) A prepreg comprising the epoxy resin composition according to any one of the above 14) to 22).

36) A thermally conductive material, characterized by containing the epoxy resin composition of any one of the above 14) to 22).

The latent curing agent of the present invention has high storage stability and curability, and is effective in storage stability (pot life), solvent resistance, moisture resistance, and dispersibility.

Detailed Description

The present invention will be specifically described below.

The latent curing agent for epoxy resins is characterized by being coated with a resin having a main chain structure (1) in which 2 nitrogen atoms are bonded to each other via a linear or cyclic low-molecular aliphatic hydrocarbon group containing no ester bond, and at least one of the 2 nitrogen atoms forms a urea bond.

In the present invention, in the linear or cyclic low-molecular aliphatic hydrocarbon group having no ester bond in the main chain structure from the nitrogen atom contained in the urea bond to the other nitrogen atoms present in the same molecular chain, the number of carbon atoms contained in the molecular chain from the urea bond to the other nitrogen atoms is preferably 1 to 18. If the number of carbon atoms is more than 18, the storage stability, dispersibility of the curing agent and moisture resistance may not be sufficiently exhibited, and from such a viewpoint, the number of carbon atoms is preferably 1 to 12, more preferably 1 to 9. The main chain structure as used herein means a structure other than a side chain in a structural chain connecting 2 nitrogen atoms, the side chain not including a branch point, and the 2 nitrogen atoms containing a nitrogen atom forming a urea bond. The structure starting from the branch point is a structural chain having a bond structure containing a nitrogen atom before the branch point.

In order to effectively coat the surface of the curing agent, the resin coated with the curing agent (a) for epoxy resins is characterized in that the compound having a structure in which a main chain structure thereof is bonded via a linear or cyclic low-molecular aliphatic hydrocarbon group having no ester bond has 2 nitrogen atoms and at least 1 nitrogen atom forms a urea bond. In the compound having 3 or more nitrogen atoms, since the reactivity of the functional group having each nitrogen atom is different, the control of the resin forming reaction for coating the surface of the curing agent becomes difficult, and storage stability, moisture resistance, and dispersibility of the curing agent may be impaired.

The present invention is characterized by having a structure (1) in which 2 nitrogen atoms are bonded to each other via a linear or cyclic low-molecular aliphatic hydrocarbon group, and by having no oxygen atom other than an oxygen atom forming a urea bond in a main chain structure up to other nitrogen atoms present in the same molecular chain. Examples of the structure having such a structure include an ester structure and an ether structure. In the case of such a structure, storage stability, solvent resistance and moisture resistance cannot be sufficiently achieved.

Here, when a nitrogen atom other than the nitrogen atom forming a urea bond among the 2 nitrogen atoms belonging to the structure (1) forms any one bond selected from a urethane bond and a biuret bond, the structure may be bonded to a structure derived from an active hydrogen compound (b2) described later, the structure forming a bond with an aromatic compound to which 2 or more nitrogen atoms are bonded.

As an example of the structure (1), there can be mentioned the following structures,

a structure in which the structure is bonded to other nitrogen atoms other than the nitrogen atom through 6 methylene chains from the urea bond and bonded to other molecular chains through an urea bond or a urethane bond or a biuret bond;

a structure in which the urea bond is bonded to a nitrogen atom other than the nitrogen atom through a 6 methylene chain, and the two nitrogen atoms have 1 secondary or tertiary carbon and 2 methyl groups therebetween;

a structure in which the urea bond and the other nitrogen atom are bonded directly through a cyclohexyl ring or through a cyclohexyl ring, a methylene chain, or the like, from the urea bond to the other nitrogen atom different from the nitrogen atom.

Examples of the structure of the aromatic compound to which 2 or more nitrogen atoms are bonded include,

a structure in which nitrogen atoms are bonded to any 2 or more positions of ortho, meta, and para positions of a benzene ring;

and a structure in which 2 or more benzene rings are bonded to each other through a methylene chain, and a nitrogen atom is bonded to any position of ortho, meta, or para positions of the respective benzene rings relative to the methylene chain.

The latent curing agent of the present invention is characterized in that the curing agent (a) for epoxy resins is coated with a film (c1) obtained by the reaction of an isocyanate compound (b1) and an active hydrogen compound (b 2).

The film (c1) covering the curing agent for epoxy resin preferably has an absorption wave number of 1630 to 1680cm from the viewpoint of balance between storage stability and reactivity^-1The infrared bonding group (x) and the absorption wave number of 1680-1725 cm^-1The infrared bonding group (y).

The bonding group (x) and the bonding group (y) can be measured using a Fourier transform infrared spectrophotometer (referred to as FT-IR). Among the bonding groups (x), particularly useful groups include urea bonds. Among the bonding groups (y), a biuret bond is particularly useful. The obtained coating film is preferably coated withThe wave number of infrared absorption is 1730-1755 cm^-1The bonding group (z) of (1). As the bonding group (z), a urethane bond is particularly preferable.

Examples of the curing agent (A) for epoxy resins used in the present invention include amine-based curing agents, acid anhydride-based curing agents such as phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and methylnorbornene diacid, phenol-based curing agents such as phenol novolak, cresol novolak, and bisphenol A novolak, thiol-based curing agents such as propylene glycol-modified polythiol, trimethylolpropane thioglycolate, and polythioether resins, boron halide salts such as ethylamine of boron trifluoride, quaternary ammonium salt-based curing agents such as phenolate of 1, 8-diazabicyclo- (5, 4, 0) -undecene-7, urea-based curing agents such as 3-phenyl-1, 1-dimethylurea, and phosphine-based curing agents such as triphenylphosphine, tetraphenylphosphonium, and tetraphenylborate, amine-based curing agents are preferred because they have excellent low-temperature curability and storage stability.

The curing agent (a) for epoxy resins used in the present invention is characterized by being composed of an amine curing agent containing an amine adduct (a) and a low-molecular amine compound (e) as main components.

Next, the amine adduct (a) will be described.

The amine adduct (a) is a compound having an amino group, and can be obtained by reacting at least one selected from the group consisting of a carboxylic acid compound, a sulfonic acid compound, an isocyanate compound, a urea compound and an epoxy resin (a1) with an amine compound (a 2). The carboxylic acid compound, sulfonic acid compound, isocyanate compound, urea compound and epoxy resin (a1) used as the raw materials of the amine adduct (a) are shown below.

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

Examples of the sulfonic acid compound include ethanesulfonic acid and p-toluenesulfonic acid.

Examples of the isocyanate compound include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, aliphatic triisocyanates, and polyisocyanates. Examples of the aliphatic diisocyanate include ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, 1, 6-hexamethylene diisocyanate, and trimethyl-1, 6-hexamethylene diisocyanate. Examples of the alicyclic diisocyanate include isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, norbornane diisocyanate, 1, 4-isocyanatocyclohexane, 1, 3-bis (isocyanatomethyl) -cyclohexane, and 1, 3-bis (isocyanatopropyl-2) -cyclohexane. Examples of the aromatic diisocyanate include tolylene diisocyanate, 4' -diphenylmethane diisocyanate, xylylene diisocyanate, and 1, 5-naphthalene diisocyanate. Examples of the aliphatic triisocyanate include 1, 3, 6-triisocyanate methylhexane, 2, 6-diisocyanatohexane acid-2-isocyanatoethyl ester and the like. Examples of the polyisocyanate include polymethylene polyphenyl polyisocyanates and polyisocyanates derived from the diisocyanate compounds. Examples of the polyisocyanate derived from the diisocyanate include isocyanurate polyisocyanates, biuret polyisocyanates, urethane polyisocyanates, allophanate polyisocyanates, and carbodiimide polyisocyanates.

Examples of the urea compound include urea, methyl urea, dimethyl urea, ethyl urea, and tert-butyl urea.

As the epoxy resin (a1), any of monoepoxy compounds, polyepoxy compounds, or a mixture thereof can be used. Examples of the monoepoxy compound include butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, p-tert-butylphenyl glycidyl ether, ethylene oxide, propylene oxide, p-xylyl glycidyl ether, glycidyl acetate, glycidyl butyrate, glycidyl hexanoate, and glycidyl benzoate. Examples of the polyepoxy compound include bisphenol epoxy resins 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 resins obtained by glycidylating other diphenols such as bisphenol, dihydroxynaphthalene, 9-bis (4-hydroxyphenyl) fluorene and the like; epoxy resins obtained by glycidylating a ternary phenol such as 1, 1, 1-tris (4-hydroxyphenyl) methane and 4, 4- (1- (4- (1- (4-hydroxyphenyl) -1-methylethyl) phenyl) ethylene) bisphenol; an epoxy resin obtained by glycidylating a quaternary phenol such as 1, 1, 2, 2-tetrakis (4-hydroxyphenyl) ethane; epoxy resins obtained by glycidylating novolak resins such as phenol novolak, cresol novolak, bisphenol A novolak, brominated phenol novolak, and brominated bisphenol A novolak; epoxy resins obtained by glycidylating polyhydric phenols, and aliphatic ether-based epoxy resins obtained by glycidylating polyhydric alcohols such as glycerin and polyethylene glycol; ether ester epoxy resins obtained by glycidating hydroxycarboxylic acids such as p-hydroxybenzoic acid and β -hydroxynaphthoic acid; ester epoxy resins obtained by glycidylating polybasic acids such as phthalic acid and terephthalic acid; glycidyl epoxy resins such as amine epoxy resins including glycidyl compounds of amine compounds such as 4, 4-diaminodiphenylmethane and m-aminophenol, and triglycidyl isocyanurate; alicyclic epoxides such as 3, 4-epoxycyclohexylmethyl-3 ', 4' -epoxycyclohexanecarboxylate, and the like.

Among the carboxylic acid compounds, sulfonic acid compounds, isocyanate compounds, urea compounds and epoxy resins (a1) used as raw materials of the amine adduct (a), the epoxy resin (a1) is preferable because it has high curability and excellent storage stability.

As the epoxy resin (a1), a polyepoxy compound is preferable in that the storage stability of the epoxy resin compound can be improved. The polyepoxy compound is preferably a glycidyl epoxy resin because the productivity of the amine adduct (a) is very high, and in order to provide a cured product having excellent adhesion and heat resistance, an epoxy resin obtained by glycidylating a polyhydric phenol is more preferable, and a bisphenol epoxy resin is still more preferable. Further preferred are an epoxy resin obtained by glycidylating bisphenol A and an epoxy resin obtained by glycidylating bisphenol F. Further preferred is an epoxy resin obtained by glycidylating bisphenol A. These epoxy resins may be used alone or in combination.

In order to obtain an epoxy resin composition having a good balance between curability and storage stability, the total chlorine content of the epoxy resin (a1) is preferably 2500ppm or less.

More preferably 2000ppm or less, still more preferably 1500ppm or less, still more preferably 800ppm or less, still more preferably 400ppm or less, still more preferably 180ppm or less, still more preferably 100ppm or less, still more preferably 80ppm or less, and still more preferably 50ppm or less.

In the present invention, the total chlorine amount 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. The total chlorine amount was measured according to the following method. The epoxy resin composition was repeatedly washed and filtered using xylene until no epoxy resin was present. Then, the filtrate was distilled under reduced pressure at 100 ℃ or lower to obtain an epoxy resin. 1 to 10g of the obtained epoxy resin sample was precisely weighed so that the dropping amount was 3 to 7ml, and the epoxy resin sample was dissolved in 25ml of ethylene glycol monobutyl ether, 25ml of a propylene glycol solution containing 1 equivalent of KOH was added thereto, and after boiling for 20 minutes, the epoxy resin sample was calculated from the dropping amount by titration with a silver nitrate aqueous solution.

By using the epoxy resin (a1) having a total chlorine amount of 2500ppm or less, a curing agent having high curing reactivity can be obtained.

In addition, the total chlorine amount is preferably 0.01ppm or more for easy control of the shell-forming reaction. More preferably 0.02ppm or more, more preferably 0.05ppm or more, more preferably 0.1ppm or more, more preferably 0.2ppm or more, and still more preferably 0.5ppm or more. By setting the total chlorine amount to 0.1ppm or more, the shell-forming reaction can be efficiently performed on the surface of the curing agent, and a shell having excellent storage stability can be obtained. The total chlorine amount of the curing agent is, for example, preferably in the range of 0.1ppm to 200ppm, more preferably in the range of 0.2ppm to 80ppm, and still more preferably in the range of 0.5ppm to 50 ppm.

The chlorine contained in the 1, 2-chloroethanol group among all the chlorine is generally referred to as hydrolyzable chlorine, and the amount of hydrolyzable chlorine in the epoxy resin used as a raw material of the amine adduct is preferably 50ppm or less, more preferably 0.01 to 20ppm, and still more preferably 0.05 to 10 ppm. The hydrolyzable chlorine is measured by the following method. A3 g sample is dissolved in 50ml toluene, and 0.1 equivalent KOH in methanol solution 20ml is added thereto, and after boiling for 15 minutes, the amount of hydrolyzable chlorine obtained by calculation from the titration amount titrated with an aqueous silver nitrate solution is 50ppm or less, which is advantageous for both high curability and storage stability, and exhibits excellent electrical characteristics, and thus is preferable.

As the amine compound (a2), there may be mentioned compounds having at least 1 primary and/or secondary amino group but no tertiary amino group, and compounds having at least 1 tertiary amino group and at least 1 active hydrogen.

Examples of the compound having at least 1 primary and/or secondary amino group but no tertiary amino group include primary amines having no tertiary amino group, such as methylamine, ethylamine, propylamine, butylamine, 1, 2-ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, ethanolamine, propanolamine, cyclohexylamine, isophoronediamine, aniline, toluidine, diaminodiphenylmethane, and diaminodiphenylsulfone; secondary amines having no tertiary amino group such as dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, dimethanolamine, diethanolamine, dipropanolamine, dicyclohexylamine, piperidine, piperidone, diphenylamine, phenylmethylamine, phenylethylamine, and the like.

In the compound having at least 1 tertiary amino group and at least 1 active hydrogen, examples of the active hydrogen group include a primary amino group, a secondary amino group, a hydroxyl group, a thiol group, a carboxylic acid, and a hydrazide group.

Examples of the compound having at least 1 tertiary amino group and at least 1 active hydrogen group include aminoalcohols such as 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, methyldiethanolamine, triethanolamine and N-. beta. -hydroxyethylmorpholine, aminophenols such as 2- (dimethylaminomethyl) phenol and 2, 4, 6-tris (dimethylaminomethyl) phenol, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-methoxyhydroxyl group, and the like, Imidazoles such as 1-aminoethyl-2-methylimidazole, 1- (2-hydroxy-3-phenoxypropyl) -2-ethyl-4-methylimidazole, 1- (2-hydroxy-3-butoxypropyl) -2-methylimidazole and 1- (2-hydroxy-3-phenoxypropyl) -2-ethyl-4-methylimidazole, 1- (2-hydroxy-3-phenoxypropyl) -2-phenylimidazoline, 1- (2-hydroxy-3-butoxypropyl) -2-methylimidazoline, 2-methylimidazoline, 2, 4-dimethylimidazoline, 2-ethylimidazoline, 2-ethyl-4-methylimidazoline, 2-benzylimidazoline, 2-phenylimidazoline, 2- (o-tolyl) imidazoline, tetramethylene-bis-imidazoline, 1, 3-trimethyl-1, 4-tetramethylene-bis-imidazoline, 1, 3, 3-trimethyl-1, 4-tetramethylene-bis-imidazoline, 1, 3-trimethyl-1, 4-tetramethylene-bis-4-methylimidazoline, 1, 3, 3-trimethyl-1, 4-tetramethylene-bis-4-methylimidazoline, 1, 2-phenylene-bis-imidazoline, poly (ethylene-co-butylene-bis-4-methylimidazoline, poly (ethylene-co-butylene co-, Imidazolines such as 1, 3-phenylene-bis-imidazoline, 1, 4-phenylene-bis-imidazoline, and 1, 4-phenylene-bis-4-methylimidazoline, tertiary amino amines such as dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, dipropylaminomethylamine, dibutylaminomethylamine, N-methylpiperazine, N-aminoethylpiperazine, and diethylaminoethylpiperazine, aminothiols such as 2-dimethylaminoethanethiol, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptopyridine, and 4-mercaptopyridine, aminothiols such as N, N-dimethylaminobenzoic acid, N, N-dimethylglycine, and mixtures thereof, Aminocarboxylic acids such as nicotinic acid, isonicotinic acid and picolinic acid, and aminohydrazides such as N, N-dimethylglycinyl hydrazide, nicotinyl hydrazide and isonicotinyl hydrazide.

The amine compound (a2) is preferably a compound having at least 1 tertiary amino group and at least 1 active hydrogen, more preferably an imidazole, and even more preferably 2-methylimidazole or 2-ethyl-4-methylimidazole, from the viewpoint of excellent balance between storage stability and curability.

The amine adduct (a) used in the present invention is obtained by, for example, reacting an epoxy resin (a1) and an amine compound (a2) in the range of preferably 0.5 to 10 equivalents (more preferably 0.8 to 5 equivalents, and still more preferably 0.95 to 4 equivalents) of active hydrogen groups in the amine compound (b1) with respect to 1 equivalent of epoxy groups in the epoxy resin (a1) in the presence of a solvent as necessary, for example, at a temperature of 50 to 250 ℃ for 0.1 to 10 hours.

It is advantageous to obtain the amine adduct (a) having a molecular weight distribution of 7 or less by setting the equivalent ratio of the active hydrogen groups to the epoxy groups to 0.5 or more, and it is advantageous to recover the unreacted amine compound (a2) economically by setting the content of the low-molecular amine compound (e) contained in the curing agent for epoxy resins of the present invention to a predetermined value by setting the equivalent ratio to 10 or less.

In the reaction for obtaining the amine adduct (a) from the epoxy resin (a1) and the amine compound (a2), the solvent to be used as needed includes hydrocarbons such as benzene, toluene, xylene, cyclohexane, mineral spirits, and naphtha, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, esters such as ethyl acetate, n-butyl acetate, and propylene glycol monomethyl ether acetate, alcohols such as methanol, isopropanol, n-butanol, butyl cellosolve, and butyl carbitol, and water, and these solvents can be used in combination.

Examples of the low-molecular-weight amine compound (e) contained in the curing agent (a) for epoxy resins used in the present invention include compounds having a primary amino group, a secondary amino group and/or a tertiary amino group. They may be used in combination.

Examples of the compound having a primary amino group include methylamine, ethylamine, propylamine, butylamine, 1, 2-ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, ethanolamine, propanolamine, cyclohexylamine, isophoronediamine, aniline, toluidine, diaminodiphenylmethane, and diaminodiphenylsulfone.

Examples of the compound having a secondary amino group include dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, dimethanolamine, diethanolamine, dipropanolamine, dicyclohexylamine, piperidine, piperidone, diphenylamine, phenylmethylamine, and phenylethylamine.

Examples of the compound having a tertiary amino group include tertiary amines such as trimethylamine, triethylamine, benzyldimethylamine, N' -dimethylpiperazine, propylenediamine, and 1, 8-diazabicyclo- (5, 4, 0) -undec-7, 1, 5-diazabicyclo- (4, 3, 0) -nonene-5; amino alcohols such as 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, methyldiethanolamine, triethanolamine and N-beta-hydroxyethylmorpholine; aminophenols such as 2- (dimethylaminomethyl) phenol and 2, 4, 6-tris (dimethylaminomethyl) phenol; imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-aminoethyl-2-methylimidazole, 1- (2-hydroxy-3-phenoxypropyl) -2-ethyl-4-methylimidazole, 1- (2-hydroxy-3-butoxypropyl) -2-methylimidazole, and 1- (2-hydroxy-3-butoxypropyl) -2-ethyl-4-methylimidazole; 1- (2-hydroxy-3-phenoxypropyl) -2-phenylimidazoline, 1- (2-hydroxy-3-butoxypropyl) -2-methylimidazoline, 2, 4-dimethylimidazoline, 2-ethylimidazoline, 2-ethyl-4-methylimidazoline, 2-benzylimidazoline, 2-phenylimidazoline, 2- (o-tolyl) imidazoline, tetramethylene-bis-imidazoline, 1, 3-trimethyl-1, 4-tetramethylene-bis-imidazoline, 1, 3, 3-trimethyl-1, 4-tetramethylene-bis-imidazoline, 1, 3-trimethyl-1, imidazolines such as 4-tetramethylene-bis-4-methylimidazoline, 1, 3, 3-trimethyl-1, 4-tetramethylene-bis-4-methylimidazoline, 1, 2-phenylene-bis-imidazoline, 1, 3-phenylene-bis-imidazoline, 1, 4-phenylene-bis-imidazoline, and 1, 4-phenylene-bis-4-methylimidazoline; tertiary amino amines such as dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, dipropylaminoethylamine, dibutylaminoethylamine, N-methylpiperazine, N-aminoethylpiperazine, and diethylaminoethylpiperazine; aminothiols such as 2-dimethylaminoethanethiol, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptopyridine, and 4-mercaptopyridine, and aminocarboxylic acids such as N, N-dimethylaminobenzoic acid, N, N-dimethylglycine, nicotinic acid, isonicotinic acid, and picolinic acid; aminohydrazides such as N, N-dimethylglycine hydrazide, nicotinyl hydrazide and isonicotinyl hydrazide.

As the low-molecular compound (e), in order to obtain an epoxy resin composition having excellent storage stability, a compound having a tertiary amino group is preferable, imidazoles are more preferable, and 2-methylimidazole and 2-ethyl-4-methylimidazole are still more preferable.

By setting the content of the low-molecular compound (e) to 0.001 parts by mass or more, a dense shell can be formed in the shell-forming reaction, and the microcapsule-type curing agent (D) for epoxy resin having high storage stability can be obtained.

If the content of the low-molecular compound (e) is more than 10 parts by mass, the potential and solvent resistance properties are impaired. Further, the reaction of the eluted low-molecular-weight compound (E) with the epoxy resin (E) can easily generate aggregates, which impair dispersibility.

The low-molecular-weight compound (e) may be mixed with the amine adduct (a) after the production of the amine adduct (a), or may be mixed before and/or during the production of the amine adduct (a). In addition, an unreacted product of the amine compound (a2) which is a raw material of the amine adduct (a) may be used as the low-molecular amine compound (e).

Examples of the form of the curing agent (a) for epoxy resins include liquid, bulk, granular, and powder forms, but the granular form or the powder form is preferable, and the powder form is more preferable. In the present invention, the powder is not particularly limited, but an average particle diameter of 0.1 to 50 μm is preferable, and an average particle diameter of 0.5 to 10 μm is more preferable. When the thickness is 50 μm or less, a homogeneous cured product can be obtained. The particle diameter in the present invention means a stokes diameter measured by a light scattering method. The average particle diameter means a median diameter. The shape is not particularly limited, and may be spherical or irregular, and spherical is preferable for reducing the viscosity of the master batch or the one-pack epoxy resin composition. Here, the spherical shape includes a regular spherical shape and an irregular shape having rounded corners.

The total chlorine amount of the curing agent (A) for epoxy resins of the present invention is preferably 2500ppm or less. More preferably 2000ppm or less, still more preferably 1500ppm or less, still more preferably 800ppm or less, still more preferably 400ppm or less, still more preferably 180ppm or less, still more preferably 100ppm or less, still more preferably 80ppm or less, and still more preferably 50ppm or less. By setting the total chlorine amount to 2500ppm or less, an epoxy resin composition having a good balance between curability and storage stability can be obtained.

In addition, the total chlorine amount of the curing agent (A) for epoxy resin is preferably 0.01ppm or more for easy control of the shell-forming reaction. More preferably 0.02ppm or more, more preferably 0.05ppm or more, more preferably 0.1ppm or more, more preferably 0.2ppm or more, and still more preferably 0.5ppm or more. By setting the total chlorine amount to 0.1ppm or more, the shell-forming reaction can be efficiently performed on the surface of the curing agent, and a shell having excellent storage stability can be obtained.

Next, the isocyanate compound (b1) will be described.

The isocyanate compound (b1) used in the present invention is a compound having an isocyanate group, and 1 to 95% by mass of the isocyanate compound is the low-molecular 2-functional aliphatic isocyanate compound (b 1-1). The low molecular 2-functional aliphatic isocyanate compound is a linear or alicyclic aliphatic compound having 2 isocyanate groups, and contains 90% or more of compounds having a number average molecular weight of 1000 or less in GPC measurement according to the method described in examples.

Examples of such isocyanate compounds include linear low-molecular-weight 2-functional aliphatic isocyanate compounds such as ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, 1, 6-hexamethylene diisocyanate, 1, 8-octane diisocyanate, 2, 4-trimethylhexamethylene diisocyanate, and 1, 12-dodecane diisocyanate. Examples of the alicyclic low-molecular-weight 2-functional aliphatic isocyanate compound include isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, norbornane diisocyanate, 1, 4-isocyanatocyclohexane, 1, 3-bis (isocyanatomethyl) -cyclohexane, and 1, 3-bis (isocyanatopropyl-2) -cyclohexane. Further, a urethane-type low-molecular 2-functional aliphatic isocyanate may also be used. The urethane-type low-molecular-weight 2-functional isocyanate having a number average molecular weight of 1000 or less can be obtained by reacting a low-molecular-weight aliphatic diisocyanate monomer with a polyol. Examples of the polyhydric alcohol used herein include ethylene glycol, propylene glycol, 1, 3-butanediol, 1, 4-butanediol, diethylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, trimethylolpropane, and the like. These polyols may be used in combination. Among these examples, diisocyanate-1, 6-hexamethylene diisocyanate and 1, 8-diisocyanatooctane are preferable, and diisocyanate-1, 6-hexamethylene diisocyanate is more preferable, from the viewpoint of balance among curability, storage stability and storage stability.

The amount of the low-molecular 2-functional aliphatic isocyanate compound (b1-1) in the isocyanate compound (b1) is 1 to 95% by mass in order to achieve excellent storage stability and curability.

If the content is less than 1% by mass or more than 95% by mass, the storage stability and solvent resistance are deteriorated.

From such a viewpoint, the amount of the low molecular 2-functional aliphatic isocyanate compound (b1-1) in the isocyanate compound (b1) is preferably 7% by mass or more and less than 90% by mass, more preferably 7% by mass or more and less than 70% by mass, and still more preferably 10% by mass or more and less than 50% by mass.

Examples of the isocyanate compound other than the low-molecular-weight 2-functional aliphatic isocyanate compound (b1-1) contained in the isocyanate compound (b1) include (1) an aromatic isocyanate, (2) an aliphatic triisocyanate, and (3) an addition-type aliphatic polyisocyanate, and the aromatic isocyanate compound (b1-2) is preferable from the viewpoint of balance between curability, storage stability, and solvent resistance.

Examples of the aromatic isocyanate compound (b1-2) include aromatic diisocyanate, aromatic triisocyanate and aromatic polyisocyanate. Examples of the aromatic diisocyanate include toluene diisocyanate, 4' -diphenylmethane diisocyanate, xylylene diisocyanate, and 1, 5-naphthalene diisocyanate, examples of the aromatic triisocyanate include triphenylmethane triisocyanate and tris (isocyanatophenyl) thiophosphate, and examples of the aromatic polyisocyanate include polyisocyanates such as polymethylene polyphenyl polyisocyanate and/or isocyanurate polyisocyanates, biuret polyisocyanates, and carbodiimide polyisocyanates derived from aromatic diisocyanates and/or aromatic triisocyanate compounds.

Among them, tolylene diisocyanate, polymethylene polyphenyl polyisocyanate or carbonyldiamine polyisocyanate derived from polymethylene polyphenyl polyisocyanate are preferable from the viewpoint of obtaining an epoxy resin composition having high dispersibility in an epoxy resin and further having an excellent balance among storage stability, solvent resistance, moisture resistance and dispersibility.

As other isocyanates, (1) as aliphatic triisocyanates, 1, 3, 6-triisocyanate methylhexane, 2, 6-diisocyanatohexane-2-isocyanatoethyl ester and the like can be mentioned.

(2) The addition-type aliphatic polyisocyanate is an addition-type polyisocyanate derived from an aliphatic isocyanate monomer which is an aliphatic diisocyanate, an alicyclic diisocyanate, an araliphatic diisocyanate, an aliphatic triisocyanate or an alicyclic triisocyanate, and examples thereof include an isocyanurate type polyisocyanate and a biuret type polyisocyanate.

Examples of the aliphatic diisocyanate used as a raw material for the addition type aliphatic polyisocyanate include ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, 1, 6-hexamethylene diisocyanate, 1, 8-octane diisocyanate, 2, 4-trimethylhexamethylene diisocyanate, and 1, 12-dodecane diisocyanate, and examples of the alicyclic diisocyanate include isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, norbornane diisocyanate, 1, 4-isocyanatocyclohexane, 1, 3-bis (isocyanatomethyl) -cyclohexane, and 1, 3-bis (isocyanatopropyl-2) -cyclohexane, and aliphatic triisocyanate, examples thereof include 1, 6, 11-undecane triisocyanate, 1, 8-diisocyanate-4-isocyanatomethyloctane, 1, 3, 6-hexamethylene triisocyanate, 2, 6-diisocyanatohexanoate-2-isocyanatoethyl ester, 2, 6-diisocyanatohexanoate-1-methyl-2-isocyanatoethyl ester and the like, and examples of the alicyclic triisocyanate compound include tricyclohexylmethane triisocyanate, bicycloheptane triisocyanate and the like. Examples of the araliphatic diisocyanates include tetramethylxylylene diisocyanate and xylylene diisocyanate.

When the addition type aliphatic polyisocyanate is derived, aliphatic diisocyanate and aliphatic triisocyanate are preferable because high reactivity can be obtained, and aliphatic diisocyanate is more preferable, and 1, 6-hexamethylene diisocyanate is further preferable.

When an isocyanurate type polyisocyanate is to be obtained, it can be obtained by cyclizing 3 polymerization of an aliphatic isocyanate monomer using a quaternary ammonium salt or the like; when a biuret type polyisocyanate is to be obtained, it can be obtained by reacting an aliphatic isocyanate monomer with a biuretizing agent such as water.

The addition type aliphatic polyisocyanate is preferably a biuret type polyisocyanate or an isocyanurate type polyisocyanate, and a biuret type polyisocyanate is more preferably because a latent curing agent having high stability can be obtained.

When isocyanate compounds of different types are used, the reactivity of each isocyanate compound is different, and therefore, a film obtained by the reaction may be uneven, and it is difficult to obtain a latent curing agent of stable quality, and the storage stability and solvent resistance may be low, and from this point, it is common to avoid using 2 or more isocyanates in combination. Further, low-molecular aliphatic isocyanate compounds are generally not suitable for combined use because they are inferior in reactivity to aromatic isocyanate compounds.

In contrast, the present inventors have conducted intensive studies to solve the above problems, and as a result, have found that when a low molecular 2-functional aliphatic isocyanate compound (b1-1) and an aromatic isocyanate compound (b1-2) are used in combination within a specific range, a latent curing agent having an excellent balance among curability, storage stability and solvent resistance can be obtained, contrary to the above expectations. Further, since the aliphatic isocyanate compound is generally inferior in reactivity to the aromatic isocyanate compound, when both are reacted together, a person skilled in the art generally uses an addition-type aliphatic polyisocyanate obtained by polyfunctionalizing the aliphatic isocyanate compound by a preliminary reaction, but contrary to expectation, a latent curing agent having storage stability and excellent solvent resistance can be provided by using a low molecular 2-functional aliphatic isocyanate compound (b1-1) in the form of a monomer.

The isocyanate compound (b1) may be reacted together or in batches, and if the low-molecular-weight 2-functional aliphatic isocyanate compound (b1-1) is reacted simultaneously with another isocyanate compound, the intended effect of the present invention may be further exhibited.

Examples of the active hydrogen compound (b2) used in the present invention include water, a compound having 1 or more primary and/or secondary amino groups in 1 molecule, and a compound having 1 or more hydroxyl groups in 1 molecule. Water and compounds having 1 or more hydroxyl groups in 1 molecule are preferred. These compounds may also be used in combination.

As the compound having 1 or more primary and/or secondary amino groups in 1 molecule used as the active hydrogen compound (b2), aliphatic amines, alicyclic amines, and aromatic amines can be used. Examples of the aliphatic amine include alkylamines such as methylamine, ethylamine, propylamine, butylamine, and dibutylamine; alkylene diamines such as 1, 2-ethylenediamine, propylenediamine, butylenediamine, and hexamethylenediamine; polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; polyoxyalkylene polyamines such as polyoxypropylene diamine and polyoxyethylene diamine. Examples of the alicyclic amine include cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, isophoronediamine, and examples of the aromatic amine include aniline, toluidine, benzylamine, naphthylamine, diaminodiphenylmethane, and diaminodiphenylsulfone.

Examples of the compound having 1 or more hydroxyl groups in 1 molecule used as the active hydrogen compound (b2) include alcohol compounds and phenol compounds. Examples of the alcohol compound include monoalcohols such as methanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, lauryl alcohol, dodecanol, stearyl alcohol, eicosanol, allyl alcohol, crotyl alcohol, propiolic alcohol, cyclopentanol, cyclohexanol, benzyl alcohol, cinnamyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and diethylene glycol monobutyl ether, and polyhydric alcohols such as ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1, 3-butanediol, 1, 4-butanediol, hydrogenated bisphenol a, neopentyl glycol, glycerol, trimethylolpropane, and pentaerythritol.

Further, examples of the polyhydric alcohols include compounds having 2 or more secondary hydroxyl groups in 1 molecule, which are obtained by reacting a compound having 1 or more epoxy groups in 1 molecule with a compound having 1 or more hydroxyl groups, carboxyl groups, primary or secondary amino groups, and mercapto groups in 1 molecule. Among these alcohol compounds, any of primary, secondary or tertiary alcohols may be used. Examples of the phenol compound include monophenols such as phenol, cresol, xylenol, carvacrol, thymol and naphthol, and polyphenols such as catechol, resorcinol, hydroquinone, bisphenol a, bisphenol F, pyrogallol and phloroglucinol. As the compound having 1 or more hydroxyl groups in 1 molecule, polyhydric alcohols, polyhydric phenols, and the like are preferable. Polyols are more preferred.

The reaction of the isocyanate compound (b1) with the active hydrogen compound (b2) is usually carried out at a temperature in the range of-10 ℃ to 150 ℃. When the temperature is 150 ℃ or higher, the coating film obtained by the reaction between the isocyanate component (b1) and the active hydrogen compound (b2) becomes non-uniform, and thus storage stability may not be sufficiently achieved, and when the temperature is lower than-10 ℃, the reaction may not be sufficient, and thus storage stability may not be achieved. From such a viewpoint, the reaction temperature is preferably from 0 ℃ to 120 ℃, more preferably from 10 ℃ to 100 ℃.

The reaction time is usually 10 minutes to 12 hours, and if it is less than 10 minutes, the reaction may be insufficient and storage stability may not be achieved, and if it is 12 hours or more, productivity is low and it is not industrially suitable.

The reaction may be carried out in a dispersion medium, if necessary. Examples of the dispersion medium include solvents, plasticizers, resins, and the like. Examples of the solvent include hydrocarbons such as benzene, toluene, xylene, cyclohexane, mineral spirits and naphtha, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate, n-butyl acetate and propylene glycol monomethyl ether acetate, alcohols such as methanol, isopropanol, n-butanol, butyl cellosolve and butyl carbitol, and water. Examples of the plasticizer include phthalic acid diesters such as dibutyl phthalate and di (2-ethylhexyl) phthalate, aliphatic dibasic acid esters such as di (2-ethylhexyl) adipate, phosphoric acid triesters such as tricresyl phosphate, and glycol esters such as polyethylene glycol esters. Examples of the resins include silicone resins, epoxy resins, and phenol resins.

The ratio of the isocyanate compound (b1) to the active hydrogen compound (b2) is usually in the range of 1:0.1 to 1:1000 in terms of equivalent ratio of isocyanate groups in the isocyanate component (b1) to active hydrogens in the active hydrogen compound (b 2).

Examples of the method of coating the curing agent (a) for epoxy resin with the reactant of the isocyanate compound (b1) and the active hydrogen compound (b2) include a method of dissolving the obtained reactant and precipitating the reactant on the surface of the curing agent (a) for epoxy resin by reducing the solubility of the reactant in a liquid in which the curing agent (a) for epoxy resin is dispersed; a method of reacting an isocyanate compound (b1) with an active hydrogen compound (b2) in a state where the epoxy resin curing agent (a) is dispersed in a dispersion medium to precipitate a reactant on the surface of the epoxy resin curing agent (a), or a method of forming a reactant on the surface of the epoxy resin curing agent (a) as a reaction site. The latter method is preferable because the reaction and the coating can be carried out simultaneously.

The obtained coating film (c1) was characterized by having an absorption wave number of 1630cm^-1～1680cm^-1Has a binding group (x) for infrared ray and an absorption wave number of 1680cm^-1～1725cm^-1The infrared binding group (y) of (2). As the binding group (y), a biuret bond is particularly preferable. Further, it is preferable to have an absorption wave number of 1730cm^-1～1755cm^-1The infrared binding group (z). As the binding group (z), a urethane bond is particularly preferable.

The urea bond and biuret bond are formed by reacting an isocyanate compound with water and/or an amine compound having 1 or more primary and/or secondary amino groups in 1 molecule. The urethane bond is formed by reacting an isocyanate compound with a compound having 1 or more hydroxyl groups in 1 molecule.

The latent curing agent for epoxy resin of the present invention is preferably formed into a microcapsule type epoxy resin curing agent (D) described below because higher stability can be obtained. The microcapsule-type epoxy resin curing agent (D) of the present invention is a curing agent having a core-shell structure in which the latent curing agent (a) for epoxy resins of the present invention is used as a core and a shell (C2) is formed by a reaction product of the curing agent (a) for epoxy resins and an epoxy resin (C).

Examples of the epoxy resin (C) used in the present invention include bisphenol type epoxy resins 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 resins obtained by glycidylating other 2-membered phenols such as biphenol, dihydroxynaphthalene and 9, 9-bis (4-hydroxyphenyl) fluorene, epoxy resins obtained by glycidylating trihydric phenols such as 1, 1, 1-tris (4-hydroxyphenyl) methane and 4, 4- (1- (4- (1- (4-hydroxyphenyl) -1-methylethyl) phenylene) ethylidene) bisphenol, an epoxy resin obtained by glycidylating a quaternary phenol such as 1, 1, 2, 2-tetrakis (4-hydroxyphenyl) ethane, a novolak-type epoxy resin obtained by glycidylating a novolak such as phenol novolak, cresol novolak, bisphenol A novolak, bromophenol novolak, brominated bisphenol A novolak, an aliphatic ether-type epoxy resin obtained by glycidylating a polyol such as glycerol or polyethylene glycol, an ether ester-type epoxy resin obtained by glycidylating a hydroxycarboxylic acid such as p-hydroxybenzoic acid or β -hydroxynaphthoic acid, an ester-type epoxy resin obtained by glycidylating a polycarboxylic acid such as phthalic acid or terephthalic acid, a glycidyl compound of an amine compound such as 4, 4-diaminodiphenylmethane or m-aminophenol, or triglycidyl isocyanurate And alicyclic epoxides such as 3, 4-epoxycyclohexylmethyl-3 ', 4' -epoxycyclohexane carboxylate.

These epoxy resins may be used alone or in combination.

The epoxy resin (C) is preferably an epoxy resin obtained by glycidylating a polyhydric phenol, and more preferably a bisphenol-type epoxy resin, in order to impart excellent adhesiveness and heat resistance to the resulting cured product. More preferably, glycidyl compounds of bisphenol A and glycidyl compounds of bisphenol F are used. Glycidyl compounds of bisphenol A are more preferred.

Epoxy compounds generally have heterogeneous ends with chlorine incorporated into the molecule. The total chlorine amount in the epoxy resin (C) is preferably 2500ppm or less in order to obtain a cured product having excellent electrical characteristics. More preferably 2000ppm or less, still more preferably 1500ppm or less, still more preferably 800ppm or less, still more preferably 400ppm or less, still more preferably 180ppm or less, still more preferably 100ppm or less, still more preferably 80ppm or less, and still more preferably 50ppm or less. When the total chlorine content is 2500ppm or less, an epoxy resin composition having a high balance between curability and storage stability can be obtained.

In addition, the total chlorine amount of the epoxy resin (C) is preferably 0.01ppm or more for easy control of the shell-forming reaction. More preferably 0.02ppm or more, more preferably 0.05ppm or more, more preferably 0.1ppm or more, more preferably 0.2ppm or more, and still more preferably 0.5ppm or more. By setting the total chlorine amount to 0.1ppm or more, the shell-forming reaction can be efficiently performed on the surface of the curing agent, and a shell having excellent storage stability can be obtained.

The reaction of the epoxy resin curing agent (A) with the epoxy resin (C) is usually carried out at a temperature of-10 to 150 ℃ and preferably 0 to 100 ℃ for a reaction time of 1 to 168 hours, preferably 2 to 72 hours, and may be carried out in a dispersion medium. Examples of the dispersion medium include a solvent and a plasticizer.

Examples of the solvent include hydrocarbons such as benzene, toluene, xylene, cyclohexane, mineral spirits and naphtha, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate, n-butyl acetate and propylene glycol monomethyl ether acetate, alcohols such as methanol, isopropanol, n-butanol, butyl cellosolve and butyl carbitol, and water. Examples of the plasticizer include phthalic acid diesters such as dibutyl phthalate and di (2-ethylhexyl) phthalate, aliphatic dibasic acid esters such as di (2-ethylhexyl) adipate, phosphoric acid triesters such as tricresyl phosphate, and glycol esters such as polyethylene glycol esters.

The amount ratio of the curing agent (A) for epoxy resin to the epoxy resin (C) in the reaction is not particularly limited, and is usually in the range of 1:0.001 to 1:1000, preferably 1:0.01 to 1:100 in terms of mass ratio.

Examples of the method of coating a core (hereinafter referred to as "core") formed of a latent curing agent for epoxy resin of the present invention with a shell (hereinafter referred to as "core") formed of a reaction product of a curing agent (a) for epoxy resin and an epoxy resin (C) include a method of dissolving the core and precipitating the core on the surface of the core by lowering the solubility of the core in a dispersion medium in which the core is dispersed, a method of dispersing the core in an epoxy resin (C) and/or a dispersion medium in which the epoxy resin (C) is dissolved, and then reacting the curing agent (a) for epoxy resin with the epoxy resin (C) to precipitate the core on the surface of the core, and a method of forming a shell on the surface of the core by using the surface of the core as a place of reaction. The latter method is preferable because the reaction and the coating can be carried out simultaneously.

In the latter case, the curing agent (a) for epoxy resin in the core may be used, or may be added separately.

The method for forming the coating film (c1) is preferably a method in which the isocyanate compound (b1) and the active hydrogen compound (b2) are reacted with each other as reaction sites on the surface of the curing agent (a) for epoxy resin to deposit a reaction product on the surface of the curing agent (a) for epoxy resin, and thus the shell-forming reaction covered with the present shell can be efficiently performed.

The thickness of the core shell covering the surface of the core is preferably 5 to 1000nm in terms of the average layer thickness. When the thickness is 5nm or more, storage stability can be obtained, and when the thickness is 1000nm or less, practical curability can be obtained. The thickness of the layer referred to herein is observed by a transmission electron microscope. The thickness of the shell is preferably 10 to 100nm in terms of the average layer thickness.

The curing agent (D) for a microcapsule-type epoxy resin, which is obtained by coating the core with the shell, has an absorption wave number of 1630cm at least on the surface^-1～1680cm^-1Has a binding group (x) for infrared ray and an absorption wave number of 1680cm^-1～1725cm^-1The infrared binding group (y) of (2) is preferable from the viewpoint of the balance between storage stability and reactivity.

The binding group (x) and the binding group (y) can be measured using a Fourier transform infrared spectrophotometer (referred to as FT-IR). In addition, at least the surface of the curing agent (C) for epoxy resin has a binding group (x) and/or a binding group (y), which can be measured using microscopic FT-IR.

Among the binding groups (x), a urea bond is particularly useful. Among the binding groups (y), a biuret bond is mentioned as a particularly useful bond.

The latent curing agent for epoxy resins and/or the microcapsule-type curing agent (D) for epoxy resins of the present invention are preferably made into a masterbatch-type curing agent (F) described below because it makes it easy to mix with epoxy resins when obtaining a one-component epoxy resin composition.

The masterbatch-type curing agent composition (F) for epoxy resin of the present invention is obtained by blending 10 to 50000 parts by mass of an epoxy resin (E) with 100 parts by mass of a latent curing agent for epoxy resin and/or a microcapsule-type curing agent (D) for epoxy resin of the present invention. When the epoxy resin (E) is 10 parts by mass or more, a master batch type curing agent composition for epoxy resin which is easy to handle can be obtained, and when it is 50000 parts by mass or less, the performance as a curing agent can be substantially exhibited. From such a viewpoint, the amount of the epoxy resin (E) blended is preferably 100 to 5000 parts by mass, more preferably 20 to 1000 parts by mass, and particularly preferably 150 to 400 parts by mass, based on 100 parts by mass of the latent curing agent for epoxy resins and/or the curing agent (D) for microcapsule-type epoxy resins of the present invention.

The total chlorine content of the masterbatch-type curing agent composition (F) for epoxy resins of the present invention is preferably 2500ppm or less in order to achieve both high curability and storage stability.

More preferably 1500ppm or less, still more preferably 800ppm or less, still more preferably 400ppm or less, still more preferably 200ppm or less, still more preferably 100ppm or less, still more preferably 80ppm or less, and still more preferably 50ppm or less.

The epoxy resin (E) of the present invention is not particularly limited as long as the intended effects of the present invention are not impaired. Examples of the epoxy resin (E) include bisphenol type epoxy resins 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 resins obtained by glycidylating other 2-membered phenols such as biphenol and 9, 9-bis (4-hydroxyphenyl) fluorene, epoxy resins obtained by glycidylating trihydric phenols such as 1, 1, 1-tris (4-hydroxyphenyl) methane and 4, 4- (1- (4- (1- (4-hydroxyphenyl) -1-methylethyl) phenylene) ethylene) bisphenol, 1, epoxy resins obtained by glycidylating a quaternary phenol such as 1, 2, 2-tetrakis (4-hydroxyphenyl) ethane, novolak-type epoxy resins obtained by glycidylating novolak-type resins such as phenol novolak, cresol novolak, bisphenol A novolak, bromophenol novolak, and brominated bisphenol A novolak, epoxy resins obtained by glycidylating polyols, aliphatic ether-type epoxy resins obtained by glycidylating polyols such as glycerin and polyethylene glycol, ether ester-type epoxy resins obtained by glycidylating hydroxycarboxylic acids such as p-hydroxybenzoic acid and β -hydroxynaphthoic acid, ester-type epoxy resins obtained by glycidylating polycarboxylic acids such as phthalic acid and terephthalic acid, glycidyl epoxy resins such as glycidyl compounds of amine compounds such as 4, 4-diaminodiphenylmethane and m-aminophenol, amine epoxy resins such as triglycidyl isocyanurate, and alicyclic epoxides such as 3, 4-epoxycyclohexylmethyl-3 ', 4' -epoxycyclohexanecarboxylate.

These epoxy resins may be used alone or in combination.

The total chlorine content of the epoxy resin (E) is preferably 2500ppm or less in order to achieve both high curability and storage stability.

In addition, in the case where the epoxy resin (E) is the same as the epoxy resin (C), the total chlorine amount of the epoxy resin (E) is preferably 0.01ppm or more in order to easily control the shell-forming reaction. More preferably 0.02ppm or more, more preferably 0.05ppm or more, more preferably 0.1ppm or more, more preferably 0.2ppm or more, and still more preferably 0.5ppm or more. For example, the total chlorine amount is preferably in the range of 0.1ppm to 200ppm, more preferably in the range of 0.2ppm to 80ppm, and still more preferably in the range of 0.5ppm to 50 ppm.

The diol terminal impurities of the epoxy resin (E) of the present invention are preferably 0.001 to 30 mass% of the basic structural component of the epoxy resin (E).

In the present invention, the basic structural component of the epoxy resin (E) is a structure in which epoxy groups are present at all terminals. The diol terminal impurities of the epoxy resin (E) mean that at least 1 epoxy group among terminal epoxy groups has a structure of an α -diol terminal. Reference is made to "Gross law エポキシ law, volume 1 base edition I", published by the association of epoxy resin technology.

The analysis method of the basic structural components and the diol terminal impurities of the epoxy resin (E) can be performed by referring to the method described in the document cited in "Gross Lasu エポキシ colophony, volume 1, base editing I", published by the epoxy resin technology Association.

If the proportion of the diol terminal impurities in the epoxy resin (E) to the basic structural components of the epoxy resin (E) is more than 30% by mass, the water resistance of the cured product may be lowered, and if the proportion is less than 0.001% by mass, the curability of the epoxy resin may be lowered. From such a viewpoint, the proportion of the diol terminal impurities in the epoxy resin (E) to the basic structural components of the epoxy resin (E) is preferably 0.01 to 25% by mass, more preferably 0.1 to 20% by mass, particularly preferably 0.5 to 18% by mass, and more particularly preferably 1.2 to 15% by mass.

Examples of the method for producing the masterbatch-type curing agent composition (F) for epoxy resin of the present invention include a method in which the latent curing agent for epoxy resin and/or the microcapsule-type curing agent (D) for epoxy resin of the present invention, which is produced in advance, is dispersed in an epoxy resin (E) using, for example, three rolls; or a method in which the latent curing agent for epoxy resin and/or the microcapsule-type curing agent (D) for epoxy resin is/are produced in the epoxy resin (E) to obtain the latent curing agent for epoxy resin and/or the microcapsule-type curing agent (D) for epoxy resin and the master batch-type curing agent. The latter is high in productivity and is therefore preferable.

The masterbatch-type curing agent composition (F) for epoxy resin of the present invention is preferably liquid or pasty at room temperature. More preferably, the viscosity at 25 ℃ is 50 ten thousand mPa.s or less, still more preferably 1000 to 30 ten thousand mPa.s, and further preferably 3000 to 20 ten thousand mPa.s.

When the viscosity is 50 ten thousand mPa.s or less, the handling property is good, the amount of adhesion to the container can be reduced, and waste can be reduced, which is preferable.

The epoxy resin composition of the present invention is preferably prepared by blending a latent curing agent for epoxy resins and/or a microcapsule-type curing agent (D) for epoxy resins, and/or a masterbatch-type curing agent composition (F) for epoxy resins and a cyclic borate ester compound (L) together.

This can improve the storage stability of the epoxy resin composition, particularly at high temperatures.

The cyclic borate ester compound (L) is a compound obtained from boric acid and an aliphatic or aromatic diol and containing boron in a cyclic structure. Examples of such cyclic borate ester compounds include tris-o-phenylenediborate ester, bis-dimethyltrimethylene diborate ester, bis-dimethylethylenediborate ester, and bis-diethylethylenediborate ester. 2, 2 '-oxybis (5, 5' -dimethyl-1, 3, 2-dioxaborane) is particularly preferred.

The content of the cyclic borate compound (L) is 0.001 to 10 parts by mass, preferably 0.01 to 2 parts by mass, and more preferably 0.05 to 0.9 part by mass, per 100 parts by mass of the latent curing agent for epoxy resin, the microcapsule-type curing agent (D) for epoxy resin, and/or the masterbatch-type curing agent composition (F) for epoxy resin. When used in this range, the composition can be cured with excellent storage stability at high temperatures, and a cured product with excellent heat resistance and connection reliability can be obtained without impairing the original short-time curability.

The masterbatch-type curing agent composition (F) for epoxy resin of the present invention comprises a latent curing agent for epoxy resin and/or a microcapsule-type curing agent (D) for epoxy resin and an epoxy resin (E), and may contain other components within a range not to deteriorate the function thereof. The content of other components is preferably less than 30 mass%.

The one-pack epoxy resin composition is obtained by mixing the latent curing agent for epoxy resin and/or the microcapsule-type curing agent for epoxy resin (D) and/or the masterbatch-type curing agent composition for epoxy resin (F) of the present invention with an epoxy resin (J).

The epoxy resin (J) used in the epoxy resin composition of the present invention may be an epoxy resin having an average of 2 or more epoxy groups per 1 molecule, and may be the same as the epoxy resin (E). Examples thereof include bisphenol type epoxy resins 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 resins obtained by glycidylating other 2-membered phenols such as biphenol, dihydroxynaphthalene, and 9, 9-bis (4-hydroxyphenyl) fluorene, epoxy resins obtained by glycidylating trihydric phenols such as 1, 1, 1-tris (4-hydroxyphenyl) methane and 4, 4- (1- (4- (1- (4-hydroxyphenyl) -1-methylethyl) phenylene) ethylene) bisphenol, epoxy resins obtained by glycidylating quaternary phenols such as 1, 1, 2, 2-tetrakis (4-hydroxyphenyl) ethane, novolak-type epoxy resins obtained by glycidylating novolak-type resins such as phenol novolak, cresol novolak, bisphenol A novolak, bromophenol novolak, and brominated bisphenol A novolak, epoxy resins obtained by glycidylating polyols, aliphatic ether-type epoxy resins obtained by glycidylating polyols such as glycerin and polyethylene glycol, ether ester-type epoxy resins obtained by glycidylating hydroxycarboxylic acids such as p-hydroxybenzoic acid and β -hydroxynaphthoic acid, ester-type epoxy resins obtained by glycidylating polycarboxylic acids such as phthalic acid and terephthalic acid, amine-type epoxy resins such as glycidyl compounds of amine compounds such as 4, 4-diaminodiphenylmethane and m-aminophenol, and triglycidyl isocyanurate, alicyclic epoxides such as 3, 4-epoxycyclohexylmethyl-3 ', 4' -epoxycyclohexanecarboxylate.

The mixing ratio of the latent curing agent for epoxy resins and/or the microencapsulated curing agent for epoxy resins (D) and/or the masterbatch-type curing agent composition for epoxy resins (F) of the present invention to the cyclic resin (J) is determined from the viewpoint of curability and the properties of the cured product, and the latent curing agent for epoxy resins and/or the microencapsulated curing agent for epoxy resins (D) and/or the masterbatch-type curing agent composition for epoxy resins (F) of the present invention can be used in an amount of 0.1 to 1000 parts by mass per 100 parts by mass of the epoxy resin (J). More preferably 0.2 to 200 parts by mass, and still more preferably 0.5 to 30 parts by mass. When the amount is 0.1 parts by mass or more, a curing agent satisfying practical curing performance can be obtained, and when the amount is 100 parts by mass or less, a curing agent having good balance of curing performance can be obtained without locally existing the epoxy resin composition of the present invention.

The masterbatch-type curing agent composition (F) for epoxy resin used in the present invention may be mixed with a resin having a self-film-forming property, which is generally called phenoxy resin, as a high molecular weight material of the epoxy resin.

In the present invention, it is preferable to prepare an epoxy resin composition by blending a cyclic boric acid ester compound (L) in a mixture of an epoxy resin (J) and a latent curing agent for epoxy resins and/or a microcapsule-type curing agent for epoxy resins (D) and/or a masterbatch-type curing agent composition for epoxy resins (F). The amount of the cyclic borate compound (L) is 0.001 to 10 parts by mass per 100 parts by mass of the mixture of the epoxy resin (J) and the latent curing agent for epoxy resin and/or the curing agent for microcapsule epoxy resin (D) and/or the curing agent composition for masterbatch epoxy resin (F). When used in this range, the composition can be provided with excellent curability with excellent storage stability at high temperatures, and an excellent cured product can be obtained without impairing the original short-time curability, heat resistance, and connection reliability.

The latent curing agent for epoxy resin and/or the microcapsule-type curing agent (D) for epoxy resin and/or the masterbatch-type curing agent composition (F) for epoxy resin used in the present invention may be used in combination with at least 1 curing agent (K) selected from the group consisting of acid anhydrides, phenols, hydrazides and guanidines.

Examples of the acid anhydrides include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, 3-chlorophthalic anhydride, 4-chlorophthalic anhydride, benzophenone tetracarboxylic anhydride, succinic anhydride, methylsuccinic anhydride, dimethylsuccinic anhydride, dichlorosuccinic anhydride, methylnorbornene diacid, dodecylsuccinic acid, chlorendic anhydride, maleic anhydride, and the like, examples of the phenols include phenol novolak, cresol novolak, bisphenol A novolak, and the like, and examples of the acid hydrazides include succinic dihydrazide, adipic dihydrazide, phthalic dihydrazide, isophthalic dihydrazide, terephthalic dihydrazide, p-hydroxybenzoyl hydrazine, salicyloyl hydrazide, phenylaminopropionyl hydrazide, phenylthiohydrazide, maleic anhydride, and the like, Maleic acid dihydrazide and the like, and examples of guanidines include dicyandiamide, methylguanidine, ethylguanidine, propylguanidine, butylguanidine, dimethylguanidine, trimethylguanidine, phenylguanidine, diphenylguanidine, tolylguanidine and the like.

As the curing agent (K), guanidines and acid anhydrides are preferable. More preferably dicyandiamide, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, or methylnadic anhydride.

When the curing agent (K) is used, the latent curing agent for epoxy resin and/or the microcapsule-type curing agent (D) for epoxy resin and/or the masterbatch-type curing agent composition (F) of the present invention are preferably used in an amount of 0.1 to 200 parts by weight based on 1 to 200 parts by weight of the curing agent (K).

When the amount is within this range, a composition having excellent curability and storage stability can be provided, and a cured product having excellent heat resistance and water resistance can be obtained.

In the present invention, it is preferable to prepare an epoxy resin composition by blending a cyclic boric acid ester compound (L) in a mixture of the curing agent (K) and the latent curing agent for epoxy resins and/or the microcapsule-type curing agent (D) for epoxy resins and/or the masterbatch-type curing agent composition (F) for epoxy resins. The amount of the cyclic borate compound (L) is 0.001 to 10 parts by mass per 100 parts by mass of the mixture of the curing agent (K) and the latent curing agent for epoxy resins and/or the curing agent (D) for microcapsule type epoxy resins and/or the curing agent composition (F) for masterbatch type epoxy resins. When used in this range, the composition can be provided with excellent curability with excellent storage stability at high temperatures, and an excellent cured product can be obtained without impairing the original short-time curability, heat resistance, and connection reliability.

The masterbatch-type curing agent composition (F) for epoxy resin used in the present invention may contain, if necessary, an extender, a reinforcing material, a filler, conductive fine particles, a pigment, an organic solvent, a reactive diluent, a non-reactive diluent, a resin, a crystalline alcohol, a coupling agent, and the like. Examples of the filler include coal tar, glass fiber, asbestos fiber, boron fiber, carbon fiber, cellulose, polyethylene powder, polypropylene powder, quartz powder, mineral silicate, mica, asbestos powder, slate powder, kaolin, alumina trihydrate, aluminum hydroxide, chalk powder, gypsum, calcium carbonate, antimony trioxide, chlorinated polyether (penton), silica, aerosol, lithopone, barite, titanium dioxide, carbon black, graphite, carbon nanotube, fullerene, iron oxide, gold, aluminum powder, iron powder, nano-sized metal crystals, intermetallic compounds, and the like, and these can be effectively used according to the use thereof. Examples of the organic solvent include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, and butyl acetate. Examples of the reactive diluent include butyl glycidyl ether, N' -glycidyl o-toluidine, phenyl glycidyl ether, styrene oxide, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and 1, 6-hexanediol diglycidyl ether. Examples of the non-reactive diluent include dioctyl phthalate, dibutyl phthalate, dioctyl adipate, and petroleum solvents. Examples of the resin include modified epoxy resins such as polyester resins, polyurethane resins, acrylic resins, polyether resins, melamine resins, polyurethane-modified epoxy resins, rubber-modified epoxy resins, and alkyd-modified epoxy resins. Examples of the crystalline alcohol include 1, 2-cyclohexanediol, 1, 3-cyclohexanediol, 1, 4-cyclohexanediol, pentaerythritol, sorbitol, sucrose, and trimethylolpropane.

The epoxy resin composition used in the present invention comprises, as main components, a latent curing agent for epoxy resin and/or a microcapsule-type curing agent (D) for epoxy resin and an epoxy resin (E), and an epoxy resin (J) and a curing agent (K) added as needed. The epoxy resin composition of the present invention achieves the required performance by heat curing, and the main component is a component which becomes a main component of the curing reaction by heat, and is preferably 60% or more of the heat-curable component. More preferably 70% or more.

Examples of the components of the one-component epoxy resin composition that are not involved in curing include an extender, a reinforcing material, a filler, conductive particles, a pigment, an organic solvent, and resins, and these components are preferably used in an amount of 0 to 90% by mass based on the total components of the one-component epoxy resin composition.

The epoxy resin composition of the present invention is useful as an adhesive, an adhesive paste, an adhesive film, a conductive material, an anisotropic conductive material, an insulating material, a sealing material, a coating composition, a prepreg, a heat conductive material, and the like.

As the adhesive, the adhesive paste, and the adhesive film, a liquid adhesive, a film adhesive, a die bonding (bonding) material, and the like can be used. As a method for producing a film-like adhesive, for example, a solid epoxy resin, a liquid epoxy resin, and a solid urethane resin are dissolved, mixed, and dispersed in toluene so as to be 50% by weight to prepare a solution. To this was added 30 wt% of the masterbatch-type curing agent composition (F) for epoxy resin of the present invention based on the solution to prepare a varnish. The solution was applied to a polyethylene terephthalate substrate for peeling having a thickness of, for example, 50 μm so that the thickness after drying was 30 μm. By drying toluene, an adhesive film which is inert at normal temperature and exhibits adhesiveness by the action of a latent curing agent under heating can be obtained.

As the conductive material, there are a conductive film, a conductive paste, and the like. Examples of the anisotropic conductive material include an anisotropic conductive thin film and an anisotropic conductive paste. As a method for producing the adhesive film, for example, in the production of the above adhesive film, the adhesive film can be produced by mixing and dispersing a conductive material and an anisotropic conductive material, applying the mixture onto a substrate for peeling, and then drying the mixture. As the conductive particles, solder particles, nickel particles, metal crystals of a nano level, particles in which the metal surface is coated with another metal, metal particles such as gradient particles of copper and silver, or particles in which resin particles such as styrene resin, urethane resin, melamine resin, epoxy resin, acrylic resin, phenol resin, or styrene-butadiene resin are coated with a conductive thin film of gold, nickel, silver, copper, solder, or the like can be used. Generally, the conductive particles are spherical fine particles having a particle size of about 1 to 20 μm. In the case of forming a film, there is a method of coating a solvent on a base material such as polyester, polyethylene, polyimide, or polytetrafluoroethylene, and then drying the solvent.

Examples of the insulating material include an insulating adhesive film and an insulating adhesive paste. By using the above adhesive film, an insulating adhesive film as an insulating material can be obtained. In addition to the use of a sealing material, an insulating adhesive paste can be obtained by blending an insulating filler with the above filler.

The sealing material is useful as a solid sealing material, a liquid sealing material, a film sealing material, or the like, and the liquid sealing material can be used as an underfill material, a potting (potting) material, a barrier material, or the like. As a method for producing the sealing material, for example, a bisphenol a type epoxy resin, methylhexahydrophthalic anhydride as a curing agent, for example, an acid anhydride curing agent, and spherical fused silica powder are added and uniformly mixed, and then the curing agent composition (F) for masterbatch type epoxy resin obtained by the present invention is added and uniformly mixed thereto to obtain the sealing material.

Examples of the coating material include a coating material for electronic materials, a cover coating material for covering a printed wiring board, and a resin composition for interlayer insulation of a printed circuit board. As a method for producing a coating material, for example, a 50% solution is prepared from MEK by selecting silica or the like as a filler from fillers, blending a phenoxy resin other than bisphenol A epoxy resin, a rubber-modified epoxy resin, and the like, and further blending the masterbatch-type curing agent composition (F) for epoxy resin of the present invention. The laminate can be obtained by coating the polyimide film with a thickness of 50 μm, laminating the polyimide film with a copper foil, laminating the polyimide film at 60 to 150 ℃, and curing the laminate by heating at 180 to 200 ℃.

The coating composition can be produced, for example, by mixing a bisphenol a epoxy resin with titanium dioxide, talc, etc., adding a 1:1 mixed solution of MIBK/xylene as a mixed solvent, stirring, and mixing to form a main component. The masterbatch-type curing agent composition (F) for epoxy resin of the present invention is added thereto and mixed uniformly, whereby an epoxy coating composition can be obtained.

The prepreg can be produced, for example, by impregnating an epoxy resin composition into a reinforcing base material and heating the resultant. Examples of the solvent for the varnish to be impregnated include methyl ethyl ketone, acetone, ethyl cellosolve, methanol, ethanol, and isopropyl alcohol, and these solvents cannot remain in the prepreg. The type of the reinforcing material is not particularly limited, and examples thereof include paper, glass cloth, glass nonwoven fabric, aramid cloth, and liquid crystal polymer. The ratio of the resin composition component to the reinforcing base material is not particularly limited, and it is generally preferably prepared so that the resin component in the impregnated sheet is 20 to 80% by weight.

As a method for producing the thermally conductive material, for example, an epoxy resin as a thermosetting resin, a phenol novolac curing agent as a curing agent, and graphite powder as a thermally conductive filler are blended and uniformly kneaded. The master batch type curing agent composition (F) for epoxy resin of the present invention is blended to obtain a thermally conductive resin paste.

Examples

The present invention is explained based on examples. The "parts" or "%" in examples and comparative examples are based on mass unless otherwise specified.

The resins and cured products thereof according to the present examples and comparative examples were subjected to physical property evaluation tests by the following methods.

(1) Epoxy equivalent

The mass (g) of the epoxy resin containing 1 equivalent of epoxy group was determined by JIS K-7236.

(2) Total chlorine amount

1g of the sample was dissolved in 25ml of ethylene glycol monobutyl ether, to which 25ml of a1 equivalent KOH propylene glycol solution was added and boiled for 20 minutes, and then titrated with an aqueous silver nitrate solution.

(3) The total chlorine amount of the epoxy resin (a1) · (C) · (E) and the masterbatch-type curing agent composition for epoxy resin (F)

The operations of washing the epoxy resin or the epoxy resin composition with xylene and filtering are repeated until the epoxy resin is completely disappeared. Then, the filtrate was subjected to distillation under reduced pressure at 100 ℃ or lower to obtain an epoxy resin. 1 to 10g of the obtained epoxy resin sample was precisely weighed so that the titration amount was 3 to 7ml, and then dissolved in 25ml of ethylene glycol monobutyl ether, 25ml of a 1-equivalent KOH propylene glycol solution was added thereto and boiled for 20 minutes, and then titration was performed with a silver nitrate aqueous solution.

(4) Amount of hydrolyzable chlorine

A 3g sample was dissolved in 50ml of toluene, 20ml of a 0.1 equivalent KOH solution for intoxication was added thereto and boiled for 15 minutes, and then titrated with an aqueous silver nitrate solution.

(5) Viscosity of the oil

The viscosity was measured at 25 ℃ using a BM type viscometer.

(6) FT-IR measurement

The absorbance was measured by using FT/IR-660Plus, manufactured by Nippon spectral Co., Ltd.

(7) GPC measurement

The measurement was carried out under the following measurement conditions, and calibration curves were prepared using polystyrene having molecular weights of 580, 1060, 1940, 5000, 10050, 21000, and 50400 as standard substances to quantify the amounts.

Column: HCL-8120GEL SUPER 1000, 2000, 3000 manufactured by Tosoh corporation are connected in series

Eluent: tetrahydrofuran (THF)

Flow rate: 0.6ml/min

A detector: measuring at 254nm with UV8020 prepared from Tosoh

(8) Quantification of the basic structural component of the epoxy resin (E)

The operations of washing the epoxy resin composition with xylene and filtering were repeated until the epoxy resin was completely disappeared. Then, the filtrate was distilled under reduced pressure at 100 ℃ or lower to obtain an epoxy resin.

The obtained epoxy resin was analyzed and quantified by the following method. The HPLC using a high performance liquid chromatograph (AS-8020, detector UV8020, hereinafter referred to AS HPLC) manufactured by Tosoh corporation, ノバパツク C-18 manufactured by ミリポア was used AS a column. The mobile phase adopts a gradient of water/acetonitrile 70/30-0/100. HPLC analysis was performed, separation conditions were selected according to the difference in the terminal structures of both sides, and the separated liquid was separated by switching the valves. The separated liquid was distilled under reduced pressure to obtain each fraction, and the residue was subjected to MS analysis. By the MS spectrum, a peak differing from the reference peak by 18 in mass number was shown, and a peak smaller than 18 was considered as a basic structural component. The peak intensity on the chart was analyzed by HPLC for the basic structural component, and the content of the basic structural component in the epoxy resin (E) was determined by the area ratio.

(9) Quantification of diol-terminal impurities of epoxy resin (E)

The separated liquid was analyzed by MS in the same manner as in the quantification of the basic structural component of the epoxy resin (E). By MS spectrum, a peak differing from the reference peak by 18 in mass number was shown, and a peak larger than 18 was considered as a diol terminal impurity of the epoxy resin (E). The content of the diol terminal impurities relative to the basic structural component in the epoxy resin (E) was determined from the ratio of the area showing the peak intensity of the diol terminal impurities and the area showing the peak intensity of the basic structural component on the HPLC analysis chart. The detection wavelength was 254 nm.

Here, the structure of the diol terminal impurities means a structure in which the epoxy group at either or both of the terminals is opened to form 1, 2-ethanediol.

(10) Separating microcapsule type epoxy resin hardener (D) from masterbatch type curing agent composition (F) for epoxy resin

The operation of washing the masterbatch type curing agent composition for epoxy resin (F) with xylene and filtering was repeated until the epoxy resin was completely disappeared. Then repeatedly washed with cyclohexane and filtered until the xylene disappeared completely. The cyclohexane was then filtered off, and completely removed at 50 ℃ or lower, and dried.

(11) Gelation time

The vulcanization test was carried out by a hot plate medium test method using a vulcanization tester V manufactured by テイ & エスエンジニアリンゲ.

(12) Dispersibility of microcapsule-type epoxy resin curing agent (D) in masterbatch-type curing agent composition (F) for epoxy resin

Toluene was mixed with the masterbatch type curing agent composition (F) for epoxy resin so that the nonvolatile content became 90%, and the mixture was allowed to stand at 25 ℃ for 1 hour. The resultant was coated on a glass plate to a film thickness of 20 μm, the number of coating film craters (cissing) due to aggregates was counted, and dispersibility was evaluated based on the number of coating film craters due to aggregates.

When the number of coating film craters is within 10, it is regarded as "X", when it is greater than 10 and not greater than 30, it is regarded as "O", when it is greater than 30 and not greater than 50, it is regarded as "Delta", and when it is greater than 50, it is regarded as "X".

(13) Storage stability of masterbatch type curing agent composition (F) for epoxy resin

The masterbatch type curing agent composition (F) for epoxy resin was stored at 40 ℃ for one week, and the viscosity before and after storage was measured and evaluated by the viscosity increase rate. The case where the viscosity increase rate after storage was 10 times or more or gelled was regarded as X, the case where the viscosity increase rate was 5 times or more and less than 10 times was regarded as Δ, and the case where the viscosity increase rate was less than 2 times was regarded as excellent.

(14) Storage stability of one-component epoxy resin composition

A mixed solvent having an ethyl acetate/toluene ratio of 1/1 was mixed in the one-component epoxy resin composition so that the nonvolatile matter became 70%, and the mixture was allowed to stand at 25 ℃ for 1 hour. This was coated on an aluminum plate to give a dry film thickness of 30 μm, dried by heating at 70 ℃ for 5 minutes, the solvent in the composition was removed, and the composition was stored at 50 ℃ for 3 days. FT-IR measurement was carried out before and after storage at 50 ℃ for 3 days, and the residual ratio of epoxy groups was calculated.

The residual ratio was 80% or more, 60% or more and less than 80% as "excellent", 40% or more and less than 60% as "Δ", and less than 40% as "x".

(15) Curing of one-component epoxy resin compositions

When the gelation time of the one-component epoxy resin composition was measured, the temperature at which the gelation time was less than 30 minutes was 100 ℃ or less was marked as "O", the temperature at which the gelation time was more than 100 ℃ and not more than 110 ℃ was marked as "Delta", and the temperature at which the gelation time was more than 110 ℃ was marked as "X".

(16) Solvent resistance of one-component epoxy resin composition

A one-pack epoxy resin composition was prepared by mixing 30 parts of the masterbatch type curing agent composition (F) for epoxy resins with 100 parts of bisphenol A type epoxy resin (epoxy equivalent: 189 g/equivalent, total chlorine amount 1200 ppm: hereinafter referred to as epoxy resin (M)). To the one-component epoxy resin composition, a mixed solvent of ethyl acetate/toluene in a weight ratio of 1/1 was mixed so that the nonvolatile content became 70%, and then 2 samples after standing at 25 ℃ for 1 hour and after standing at 40 ℃ for 1 hour were prepared. As the solvent resistance evaluation, the time until gelation was measured by a gelation tester according to JIS C-2104, and the measurement and evaluation were carried out as follows. That is, a gel plate was held at 120 ℃, 0.4ml of a sample was placed on the plate, and after the placement, the sample was stirred and mixed by a stirring bar, and the time until no drawing (cobwebbing) occurred, that is, the time until gelation (seconds) was measured. At this time, the time difference between gelation at 25 ℃ and gelation at 40 ℃ was determined using a mixed sample with the mixed solvent. The higher the solvent resistance to the mixed solvent, the less time difference until gelation occurs between 25 ℃ and 40 ℃. The time taken for gelation at 40 ℃ is shorter than that at 20 ℃ for a composition having poor solvent resistance. When the time difference until gelation was 15% or less, it was marked as "X", when the time difference was 15 to 25%, it was marked as "O", when the time difference was 25 to 50%, it was marked as "Delta", when the time difference was 50 to 90%, and when the one-component epoxy resin composition gelled after standing at 40 ℃ for 1 hour, it was marked as "X".

(17) Short-time curability of one-component epoxy resin composition

30 parts of masterbatch type curing agent composition (F) for epoxy resin and 100 parts of epoxy resin (M) were mixed to prepare a one-component epoxy resin composition. A mixed solvent having an ethyl acetate/toluene ratio of 1/1 was mixed with the epoxy resin composition so that the nonvolatile content became 70%, and the mixture was allowed to stand at 25 ℃ for 1 hour. This was coated so that the dry film thickness became 30 μm, and the composition was dried by heating at 70 ℃ for 5 minutes to remove the solvent from the composition, thereby obtaining a film-like adhesive composition. 30kg/cm on a 190 ℃ electric hot plate²And thermocompression bonding for 30 seconds. FT-IR measurement was performed on the film-like adhesive composition before and after the press-bonding, and the characteristic peak (1608 cm) of the benzene ring was measured^-1Near) characteristic peak (925 cm) with respect to epoxy group^-1Near) was calculated, and the quick curability was evaluated from the epoxy group reaction rate. Very good when the rate of change is 65% or more, good when 65-50%, and delta when 50-40%, and 40% or lessAnd then marked as x.

(18) Moisture resistance of one-part epoxy resin composition

30 parts of a masterbatch type curing agent (F) for epoxy resin and 100 parts of epoxy resin (M) were mixed to prepare a one-component epoxy resin composition. A mixed solvent having an ethyl acetate/toluene ratio of 1/1 was mixed with the epoxy resin composition so that the nonvolatile content became 70%, and the mixture was allowed to stand at 25 ℃ for 1 hour. This was coated so that the dry film thickness became 30 μm, and the composition was dried by heating at 70 ℃ for 5 minutes to remove the solvent from the composition, thereby obtaining a film-like adhesive composition. The film was allowed to stand and treated in a constant temperature and humidity bath at 40 ℃ and a humidity of 85% for 2 hours. The film samples before and after the treatment were subjected to DSC analysis to determine the total calorific value. Under high temperature and high humidity conditions, the disappearance rate of epoxy groups contained in the film-like adhesive composition due to potential deterioration was calculated from the change rate of the total heat generation amount. The lower the epoxy group reaction rate, the more excellent the moisture resistance was evaluated. The rate of change was rated as "good" when it was 10% or less, as "delta" when it was 20% or less, as "x" when it was 30% or less, and as "x" when it exceeded 30%.

Production example 1

(production of curing agent (A) for epoxy resin)

2 equivalents of bisphenol A type epoxy resin (epoxy equivalent 185 g/equivalent, total chlorine amount 1200 ppm: hereinafter referred to as epoxy resin c-1) was reacted with 0.66 mol of o-dimethylaminomethylphenol and 0.33 mol of dimethylamine in a mixed solvent of methanol and toluene 1/1 (resin portion 50%) at 80 ℃ for 8 hours, and then the solvent was distilled off under reduced pressure at 180 ℃ to obtain a solid compound. This was pulverized to obtain curing agent a-1 for epoxy resin having an average particle diameter of 2.5. mu.m.

Production example 2

(production of curing agent (A) for epoxy resin)

2 equivalents of bisphenol A type epoxy resin (epoxy equivalent 185 g/equivalent, total chlorine amount 20 ppm: hereinafter referred to as epoxy resin c-2) and 1.5 moles of 2-methylimidazole were reacted in 1/1 mixed solvent of methanol and toluene (resin portion 50%) at 80 ℃ for 6 hours, and then the solvent was distilled off under reduced pressure at 180 ℃ to obtain a solid compound. Pulverizing to obtain powder with average particle diameter of 3

Curing agent a-2 for epoxy resin having a diameter of μm.

[ example 1]

To 200 parts of epoxy resin C-1 as epoxy resin (C), 100 parts of epoxy resin curing agent a-1 as epoxy resin curing agent (A), 1.5 parts of water as active hydrogen compound (b2), 3 parts of 1, 6-hexamethylene diisocyanate (HMDI) (manufactured by Asahi Kasei ケミカルズ Co., Ltd., デユラネ - ト (registered trademark) 50M) as isocyanate compound (b1-1), and 4 parts of MR200 (manufactured by Japan ポリウレタン (registered trademark)) as isocyanate compound (b1-2) were added, and the reaction was continued for 3 hours while stirring at 40 ℃ so that 99 mol% or more of the isocyanate groups reacted. Then, a shell-forming reaction was carried out at 40 ℃ for 20 hours to obtain a masterbatch type curing agent F-1.

The core-shell type curing agent was separated from the master batch type curing agent F-1 with xylene, dried to obtain a powder, and then placed on a glass plate to perform FT-IR measurement, whereby the presence of the binding groups (x), (y), and (z) was confirmed. In addition, the dispersibility and storage stability of the masterbatch type curing agent H-1 were evaluated. The evaluation results are shown in Table 1.

To 30 parts of the obtained master batch type curing agent F-1, 100 parts of c-1 as an epoxy resin (J) was added and mixed thoroughly to obtain a one-component epoxy resin composition.

The obtained one-pack epoxy resin composition was evaluated for storage stability and curability. The evaluation results are shown in Table 1.

[ example 2]

To 200 parts of bisphenol F type epoxy resin (epoxy equivalent: 165 g/equivalent, total chlorine amount: 300ppm, hereinafter referred to as epoxy resin C-3) as epoxy resin (C), 100 parts of a-2 as curing agent (A), 2 parts of water as active hydrogen compound (b2), 1 part of 1, 6-hexamethylene diisocyanate (デユラネ - ト (registered trademark) 50M as isocyanate compound (b1-1) (manufactured by Asahi Kasei ケミカルズ Co., Ltd.), and 6 parts of MR200 (manufactured by Japanese ポリウレタン Co., Ltd. (registered trademark)) as isocyanate compound (b1-2) were added to obtain master batch type curing agent F-2 in the same manner as in example 1. In the same manner as in example 1, it was confirmed that the polymer had the binding groups (x), (y), and (z), and dispersibility and storage stability were evaluated. Further, when the master batch type curing agent F-2 was placed in a plastic cup and stored in an environment of 40 ℃ and 95% relative humidity for 12 hours with the lid open, the appearance was not abnormal and the moisture resistance was good.

Further, 100 parts of c-1 as an epoxy resin (J) was added to 30 parts of the obtained master batch type curing agent F-2 and mixed sufficiently to obtain a one-pack epoxy resin composition, which was evaluated for storage stability and curability. The evaluation results are shown in Table 1.

[ comparative examples 1 to 3]

Master batch type curing agents F-3, F-4 and F-5 were obtained in the same manner as in example 2 using the compounding ratios shown in Table 1, and dispersibility and storage stability were evaluated.

Further, 100 parts of c-1 as an epoxy resin (J) was added to 30 parts of the obtained master batch type curing agents F-3, F-4 and F-5 and mixed thoroughly to obtain a one-pack epoxy resin composition, which was evaluated for storage stability and curability. The evaluation results are shown in Table 1.

TABLE 1

Epoxy resin c-1: bisphenol A type liquid epoxy resin (epoxy equivalent 185 g/equivalent, total fluorine content 1200ppm)

Epoxy resin c-3: bisphenol F type liquid epoxy resin (epoxy equivalent 165 g/equivalent, total chlorine amount 300ppm)

MR-200: polymethylenepolyphenylene polyisocyanate available from Japanese ポリウレタン

24A: デユラネ - ト 24A (prepared by Asahi Kasei ケミカルズ Co., Ltd., biuret type polyisocyanate derived from 1, 6-hexamethylene diisocyanate, having an average functional group number of 3.4 and a1, 6-hexamethylene diisocyanate content of less than 1%)

[ example 3]

To 8 parts of dicyandiamide previously pulverized to an average particle diameter of 3 μm as a curing agent (K), 3 parts by mass of a master batch type curing agent F-2 obtained in example 2, 95 parts of c-2 as an epoxy resin (J), 5 parts of a CTBN modified epoxy resin manufactured by EP-4023(アデカ Co., Ltd.) as an epoxy resin (J), and 20 parts of calcium carbonate were added and uniformly mixed to obtain a one-component epoxy resin composition. The resulting composition had a storage stability of O and was cured at 140 ℃.

[ example 4]

To 100 parts of bisphenol F type epoxy resin (epoxy equivalent 165 g/equivalent, total chlorine amount 300ppm) as epoxy resin (J), 80 parts of methylhexahydrophthalic anhydride as curing agent (K) and 300 parts of spherical fused silica powder (average particle diameter 10 μm) were added and mixed uniformly, and 6 parts of master batch type curing agent F-2 obtained in example 2 was added and mixed uniformly to obtain a liquid sealant. The obtained liquid sealing material was sandwiched between a substrate and an LSI, and after heating at 100 ℃ for 3 hours, the liquid sealing material was further heated at 150 ℃ for 3 hours, and as a result, the liquid sealing material was cured, and thus the liquid sealing material was useful as a sealing material. The liquid sealant of the present composition is also useful as an insulating adhesive paste.

[ example 5]

40 parts of bisphenol A type epoxy resin (epoxy equivalent 2500 g/equivalent) as an epoxy resin (J) was dissolved in 30 parts of ethyl acetate, 40 parts of the master batch type curing agent F-2 obtained in example 2 and 20 parts of conductive particles (crosslinked polystyrene plated with gold) having a particle size of 5 μm were added thereto, and uniformly mixed to obtain a one-component epoxy resin composition. This was coated on a polyester film, and dried at 70 ℃ to remove ethyl acetate, thereby obtaining an anisotropic conductive film.

The obtained anisotropic conductive film was sandwiched between electrodes and heated at 200 ℃ on a hot plate at 30kg/cm²And thermocompression bonding for 20 seconds, as a result, the electrodes are bonded, and the circuit is electrically connected, and thus the anisotropic conductive material is useful.

Production example 3

(production of curing agent (A) for epoxy resin)

1.5 equivalents of bisphenol A type epoxy resin (epoxy equivalent 185 g/equivalent, total chlorine amount 1400 ppm: hereinafter referred to as epoxy resin a1-1) and 1 equivalent (in terms of active hydrogen) of 2-methylimidazole were reacted in a mixed solvent of n-butanol and toluene 1/1 (resin portion 50%) at 80 ℃. Then, when the content of 2-methylimidazole reached 0.5% (based on the resin portion) under reduced pressure, the distillation was terminated, and a solid compound for an epoxy resin was obtained. This was pulverized to obtain curing agent a-3 for epoxy resin having an average particle diameter of 2.7. mu.m.

[ example 6]

100 parts by mass of curing agent a-3 for epoxy resin, 2 parts by mass of water, 3 parts by mass of 1, 8-diisocyanate octane and 4 parts by mass of MR-200 were added to 200 parts by mass of epoxy resin C-1 as epoxy resin (C), and the reaction was continued for 3 hours while stirring at 40 ℃. Further, a shell-forming reaction was carried out at 50 ℃ for 8 hours to obtain a masterbatch-type curing agent F-6 for epoxy resins. In the same manner as in example 1, it was confirmed that the curing agent F-6 for masterbatch type epoxy resin had the bonding groups (x), (y), and (z), and the dispersibility and storage stability were evaluated. Subsequently, 30 parts of the masterbatch-type curing agent F-6 for epoxy resin obtained was mixed with 100 parts of the epoxy resin (M) to obtain a one-component epoxy resin composition, and the storage stability, curability, solvent resistance and moisture resistance of the one-component epoxy resin composition were evaluated. The evaluation results are shown in Table 2.

[ example 7]

100 parts by mass of curing agent a-3 for epoxy resin, 1.5 parts by mass of water, 2 parts by mass of HDMI, and 5 parts by mass of MR-200 were added to 200 parts by mass of epoxy resin C-3 as epoxy resin (C), and the reaction was continued for 3 hours while stirring at 40 ℃. Then, 0.5 part by mass of a cyclic boric acid ester compound (L) was added, and a shell-forming reaction was further carried out at 50 ℃ for 8 hours to obtain a masterbatch-type curing agent F-7 for epoxy resins. In the same manner as in example 1, it was confirmed that the curing agent F-7 for masterbatch type epoxy resin had the bonding groups (x), (y), and (z), and the dispersibility and storage stability were evaluated. Subsequently, 30 parts of the masterbatch-type curing agent F-7 for epoxy resin obtained was mixed with 100 parts of the epoxy resin (M) to obtain a one-component epoxy resin composition, and the storage stability, curability, solvent resistance and moisture resistance of the one-component epoxy resin composition were evaluated. The evaluation results are shown in Table 2.

[ example 8]

100 parts by mass of curing agent a-3 for epoxy resin, 2 parts by mass of water, 1 part by mass of HDMI, and 4 parts by mass of MR-200 were added to 200 parts by mass of epoxy resin C-3 as epoxy resin (C), and the reaction was continued for 3 hours while stirring at 40 ℃. Then, 1.2 parts by mass of a cyclic boric acid ester compound (L) was added, and a shell-forming reaction was further carried out at 50 ℃ for 8 hours to obtain a masterbatch-type curing agent F-8 for epoxy resins. In the same manner as in example 1, it was confirmed that the curing agent F-8 for masterbatch type epoxy resin had the bonding groups (x), (y), and (z), and the dispersibility and storage stability were evaluated. Subsequently, 30 parts of the masterbatch-type curing agent F-8 for epoxy resin obtained was mixed with 100 parts of the epoxy resin (M) to obtain a one-component epoxy resin composition, and the storage stability, curability, solvent resistance and moisture resistance of the one-component epoxy resin composition were evaluated. The evaluation results are shown in Table 2.

[ example 9]

To 200 parts by mass of an epoxy resin C-3 as an epoxy resin (C), 100 parts by mass of a curing agent a-3 for epoxy resin, 2 parts by mass of water, 2 parts by mass of デユラネ - ト D-101 manufactured by Asahi Kasei ケミカルズ (Co., Ltd.) as a urethane-type low molecular 2 functional group aliphatic isocyanate, and 5 parts by mass of MR-200 were added, and the reaction was continued for 3 hours while stirring at 40 ℃. Then, 1.2 parts by mass of a cyclic boric acid ester compound (L) was added, and a shell-forming reaction was further carried out at 50 ℃ for 8 hours to obtain a masterbatch-type curing agent F-8 for epoxy resins. In the same manner as in example 1, it was confirmed that the curing agent F-8 for masterbatch type epoxy resin had the bonding groups (x), (y), and (z), and the dispersibility and storage stability were evaluated. Subsequently, 30 parts of the obtained masterbatch-type curing agent F-8 for epoxy resin was mixed with 100 parts of the epoxy resin (M) to obtain a one-component epoxy resin composition, and the storage stability, curability, solvent resistance and moisture resistance of the one-component epoxy resin composition were evaluated. The evaluation results are shown in Table 2.

Comparative example 4

100 parts by mass of curing agent a-3 for epoxy resin, 1.5 parts by mass of water, 5 parts by mass of LTI and 2 parts by mass of MR-200 were added to 200 parts by mass of epoxy resin C-3 as epoxy resin (C), and the reaction was continued for 3 hours while stirring at 40 ℃. Further, a shell-forming reaction was carried out at 50 ℃ for 8 hours to obtain a masterbatch-type curing agent F-9 for epoxy resins. In the same manner as in example 1, it was confirmed that the masterbatch-type curing agent F-9 had the bonding groups (x), (y), and (z), and the dispersibility and the storage stability were evaluated. Subsequently, 30 parts of the masterbatch-type curing agent F-9 for epoxy resin obtained was mixed with 100 parts of the epoxy resin (M) to obtain a one-component epoxy resin composition, and the storage stability, curability, solvent resistance and moisture resistance of the one-component epoxy resin composition were evaluated. The evaluation results are shown in Table 2.

Comparative example 5

100 parts by mass of curing agent a-3 for epoxy resin, 1.5 parts by mass of water, 2 parts by mass of LTI, and 5 parts by mass of MR-200 were added to 200 parts by mass of epoxy resin C-3 as epoxy resin (C), and the reaction was continued for 3 hours while stirring at 40 ℃. Then, 0.5 part by mass of a cyclic boric acid ester compound (L) was added, and a shell-forming reaction was further carried out at 50 ℃ for 8 hours to obtain a masterbatch-type curing agent F-10 for epoxy resins. In the same manner as in example 1, it was confirmed that the curing agent F-10 for masterbatch type epoxy resin had the bonding groups (x), (y), and (z), and the dispersibility and storage stability were evaluated. Subsequently, 30 parts of the masterbatch-type curing agent F-10 for epoxy resin obtained was mixed with 100 parts of the epoxy resin (M) to obtain a one-component epoxy resin composition, and the storage stability, curability, solvent resistance and moisture resistance of the one-component epoxy resin composition were evaluated. The evaluation results are shown in Table 2.

[ examples of production of conductive thin film ]

15 parts of a bisphenol A type epoxy resin (AER-2603, manufactured by Asahi Kasei ケミカルズ), 6 parts of a phenol novolac resin (trade name "BRG-558", manufactured by Showa Kasei Kogyo K.K.), 4 parts of a synthetic rubber (trade name "ニポ - ル 1072", manufactured by Japanese ゼオン K.K., weight average molecular weight 30 ten thousand) were dissolved in 20 parts of a 1:1 (weight ratio) mixed solvent of methyl ethyl ketone and butyl cellosolve acetate. To the solution, 74 parts of silver powder was mixed, and further kneaded with three rolls. To this was further added 30 parts of the masterbatch-type curing agent F-2 for epoxy resin obtained in example 2, and the mixture was uniformly mixed to obtain a conductive adhesive. Using the obtained conductive adhesive, it was cast onto a polypropylene film having a thickness of 40 μm, and dried and semi-cured at 80 ℃ for 60 minutes to obtain a conductive film having a conductive adhesive layer having a thickness of 35 μm. Using the conductive film, a conductive adhesive layer was transferred onto the back surface of a silicon wafer using a 80 ℃ micro-thermostat (heat block). Further, the silicon wafer was cut into full pieces (full dicing), and the semiconductor chips with the conductive adhesive were bonded and cured on the lead frame at 200 ℃ for 2 minutes by a micro-thermostat, so that the chips had no problem in conductivity.

[ examples of production of conductive paste ]

To 100 parts of an epoxy resin (M), 30 parts of a masterbatch-type epoxy resin curing agent F-1 obtained in example 1, 150g of a scaly silver powder having an aspect ratio of 14 μ M in average particle diameter (manufactured by Deli chemical research Co., Ltd.) and 60g of a scaly nickel powder having an aspect ratio of 9 in average particle diameter of 10 μ M (manufactured by high purity chemical Co., Ltd.; trade name: NI 110104) were added, and the mixture was stirred until uniform and then dispersed uniformly by three-roll to prepare a conductive paste. The obtained conductive paste was screen-printed on a polyimide film substrate having a thickness of 1.4mm, and then cured by heating at 200 ℃ for 1 hour. The obtained wiring board was measured for conductivity, and as a result, it was useful as a conductive paste.

[ examples of production of Anisotropic conductive film ]

40 parts by weight of bisphenol A type epoxy resin (Asahi Kasei ケミカルズ Co., Ltd. AER6097, epoxy equivalent 42500g/eq), 30 parts by weight of phenoxy resin (Dongdu Kasei K., YP-50) were dissolved in 30 parts of ethyl acetate, 30 parts of curing agent F-2 for masterbatch type epoxy resin obtained in example 2, 5 parts of conductive particles (crosslinked polystyrene coated with gold) having a particle size of 8 μm were added thereto, and the mixture was uniformly mixed to obtain a one-component epoxy resin composition. This was coated on a polyester film, and dried at 70 ℃ to remove ethyl acetate, thereby obtaining an anisotropic conductive film.

The obtained anisotropic conductive film was sandwiched between an IC chip and an electrode, and the processing was carried out at 30kg/cm on a 200 ℃ electric hot plate²And thermocompression bonding for 20 seconds, as a result, the electrodes are bonded, and the circuit is electrically connected, and thus the anisotropic conductive material is useful.

[ examples of production of anisotropically electroconductive paste ]

50 parts by weight of bisphenol A type epoxy resin (Asahi Kasei ケミカルズ Co., Ltd.; AER6091, epoxy equivalent 480g/eq), 50 parts by weight of bisphenol A type epoxy resin (Asahi Kasei ケミカルズ Co., Ltd.; AER2603) and 5 parts by weight of ミクロパ - ル Au-205 (produced by Water accumulation chemical Co., Ltd.; specific gravity 2.67) as conductive particles were mixed, and 30 parts of the masterbatch type curing agent F-2 for epoxy resin obtained in example 2 was added thereto and mixed uniformly to obtain an anisotropic conductive paste. The obtained anisotropic conductive paste was coated on a low-alkali glass having an ITO electrode. The film was bonded to a TAB (tape automated bonding) film for test by pressing the film for 30 seconds at a pressure of 2MPa with a 230 ℃ ceramic tool. The resistance value between adjacent ITO electrodes was measured, and as a result, the paste was useful as an anisotropic conductive paste.

[ examples of production of insulating paste ]

100 parts by weight of bisphenol F type epoxy resin (product name "YL 983U", manufactured by oiled シエルエポキシ Co., Ltd.), 4 parts by weight of dicyandiamide, 100 parts by weight of silica powder, 10 parts by weight of phenyl glycidyl ether as a diluent, and 1 part by weight of organic phosphate (product name "PM-2", manufactured by Nippon Kagaku K.K.) were thoroughly mixed, and then kneaded by three rolls. Further, 30 parts of the masterbatch-type curing agent F-2 for epoxy resin obtained in example 2 was added thereto, and the mixture was uniformly mixed, and subjected to vacuum degassing and centrifugal degassing treatment to produce an insulating paste. The obtained insulating paste is used to bond semiconductor chips by heat curing at 20 ℃ for 1 hour on a resin substrate, and is useful as an insulating paste.

[ examples of production of insulating paste ]

180 parts by weight of a phenoxy resin (trade name "YP-50" manufactured by Tokyo Kasei Co., Ltd.), 40 parts by weight of a cresol novolak-type epoxy resin (epoxy equivalent: 200g/eq, trade name "EOCN-1020-. The obtained solution was applied to polyethylene terephthalate subjected to mold release treatment so that the thickness after drying became 50 μm, and heat-dried in a hot air circulation type dryer to obtain an insulating film for bonding a semiconductor. The obtained insulating film for bonding a semiconductor is cut into a supporting base material having a size of a wafer larger than 5 inches, and a resin film is stacked on the electrode side of the wafer with bump electrodes (bump electrodes). Subsequently, the supporting substrate subjected to the release treatment was held between the substrates, and the substrates were subjected to vacuum pressure bonding at 70 ℃ under 1MPa for 10 seconds to obtain a wafer with a bonding resin. Then, resin peeling was not observed in the semiconductor element with the adhesive film obtained by cutting the separated individual pieces with a dicing saw (dicing saw) (DAD-2H 6M, manufactured by DISCO) at a dicing speed of 20 mm/sec at a rotational speed of 30000 rpm. The obtained film is useful as an insulating film.

[ examples of production of sealing Material ]

50 parts by weight of a bisphenol A type epoxy resin (AER 6091, epoxy equivalent 480g/eq, manufactured by Asahi Kasei ケミカルズ Co., Ltd.), 50 parts by weight of a bisphenol A type epoxy resin (AER 2603, manufactured by Asahi Kasei ケミカルズ Co., Ltd.), 40 parts by weight of HN-2200 (manufactured by Hitachi Kasei Co., Ltd.) as a curing agent containing phthalic acid as a main component and 80 parts by weight of a spherical fused silica having an average particle diameter of 16 μm were uniformly dispersed and blended. 5 parts by weight of the curing agent F-1 for a masterbatch type epoxy resin obtained in example 1 was added thereto to obtain an epoxy resin composition. The obtained epoxy resin composition was coated on a printed wiring board in a square of 1cm so that the thickness became 60 μm, and was heated in an oven at 110 ℃ for 10 minutes to be semi-cured. Then, a silicon chip having a thickness of 370 μm and a square width of 1cm was placed on the semi-cured epoxy resin composition, and a load was applied to bring the bump into contact with the electrode of the chip and to hold the same, and complete curing treatment was performed at 220 ℃ for 1 hour. The sealing material formed of the obtained epoxy resin composition is useful because it has no problem in appearance and conduction of chips.

[ examples of production of coating Material ]

30 parts of epoxy resin (M), 30 parts of YP-50 (manufactured by Tokyo chemical Co., Ltd.) as a phenoxy resin, and 50 parts of a methyl ethyl ketone solution of a silane-modified epoxy resin containing a methoxy group (manufactured by Mitsukawa chemical Co., Ltd.; trade name: コンポセラン E103) were mixed, 30 parts of curing agent F-1 for masterbatch-type epoxy resin obtained in example 1 was added thereto, and the mixture was diluted with methyl ethyl ketone and mixed to 50% by weight to prepare a solution. The prepared solution was applied to a release PET (polyethylene terephthalate) film (SG-1 manufactured by パナツク Co.) by means of a roll coater, and dried and cured at 150 ℃ for 15 minutes to prepare a semi-cured resin (dry film) with a release film having a film thickness of 100 μm. These dry films were heat-pressed onto the above copper-clad laminate at 120 ℃ for 10 minutes and 6MPa, and then returned to room temperature, the release film was removed, and the resultant was cured at 200 ℃ for 2 hours, whereby a material useful as a coating material for interlayer insulation was obtained.

[ examples of preparation of coating composition ]

To 50 parts by weight of a bisphenol A type epoxy resin (AER 6091 manufactured by Asahi Kasei ケミカルズ Co., Ltd., epoxy equivalent 480g/cq) were added 30 parts by weight of titanium dioxide and 70 parts by weight of talc, and 140 parts by weight of a 1:1 MIBK/xylene mixed solvent was added as a mixed solvent, followed by stirring and mixing to obtain a main component. 30 parts by weight of the curing agent F-1 for a masterbatch type epoxy resin obtained in example 1 was added thereto and uniformly dispersed, thereby obtaining a composition useful as an epoxy coating composition.

[ examples of production of prepreg ]

Examples of prepregs

In a flask in an oil bath at 130 ℃ were dissolved and mixed 15 parts of a novolak type epoxy resin (EPECLON N-740 manufactured by Dainippon インキ chemical industry), 40 parts of a bisphenol F type epoxy resin (エピコ - ト 4005 manufactured by JER) and 30 parts of a bisphenol A type liquid epoxy resin (AER 2603 manufactured by Asahi Kasei ケミカルズ Co.), and the mixture was cooled to 80 ℃. Further, 15 parts of the masterbatch-type curing agent composition F-1 for epoxy resin obtained in example 1 was added thereto, and the mixture was sufficiently stirred and mixed. Cooling the resin composition to room temperature with a doctor blade to give a resin basis weight of 162g/m²The resin film was coated on a release paper to prepare a resin film. Then, the resin film was coated with a resin having an elastic modulus of 24 tons/mm to 12.5 threads/inch²The obtained Mitsubishi yang CF mixed fabric (model: TR3110, basis weight 200 g/m) was plain-woven²) And (3) superposing, namely impregnating the resin composition into the carbon fiber interwoven fabric, superposing a polypropylene film, and passing the polypropylene film between a pair of rollers with the surface temperature of 90 ℃ to prepare an interwoven prepreg. The content of the resin was 45% by weight. The obtained prepreg is useful as a prepreg obtained by aligning the fiber directions of the prepreg, laminating the layers, and molding the laminate at 150 ℃ for 1 hour under curing conditions to obtain an FRP molded product using carbon fibers as reinforcing fibers.

[ examples of production of thermally conductive epoxy resin composition ]

100 parts of bisphenol A type epoxy resin (Asahi Kasei ケミカルズ Co., Ltd., AER2603), 40 parts by weight of phenol novolac resin (available from Kagaku chemical industry Co., Ltd., methyl ethyl ketone 50% solution of trade name "タマノル 759", available from Glauca chemical industry Co., Ltd., trade name HOPG) as a curing agent for epoxy resin, and flake graphite powder (available from ユニオンカ - バイト Co., Ltd., trade name HOPG) were stirred to be uniform, and then dispersed uniformly by 3 rolls, 15 parts of the curing agent composition F-1 for masterbatch type epoxy resin obtained in example 1 was further added thereto, and sufficiently stirred and mixed, and using the obtained conductive paste, a semiconductor chip (1.5mm square, thickness 0.8mm) was mounted on a Cu lead frame and heat-cured at 150 ℃ for 30 minutes to obtain a sample for evaluation. The thermal conductivity of the obtained sample was measured by a laser pulse method. That is, the thermal conductivity K is obtained from the measured thermal diffusivity α, specific heat Cp and density σ according to the following formula K ═ α × Cp × σ, and as a result, K is 5 × 10^-3Cal/em sec. degree.C or higher, and is useful as a thermally conductive paste.

The present invention is described in detail with reference to specific embodiments, but it is apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

This application is based on Japanese patent application No. 2005-23 (Japanese application 2005-046615), the contents of which are incorporated herein by reference.

Industrial applicability

According to the present invention, an epoxy resin composition can be obtained which gives a cured product having good balance between curability and storage stability, and further having properties such as electrical properties, mechanical strength, heat resistance, and moisture resistance. The masterbatch type curing agent composition for epoxy resin using the microcapsule type curing agent for epoxy resin of the present invention can exhibit excellent performance as an adhesive, a sealing material, a filler, an insulating material, a conductive material, a prepreg, a film adhesive, an anisotropic conductive film, an anisotropic conductive paste, an insulating adhesive film, an insulating adhesive paste, an underfill material, a packaging material (packaging material), a die bonding material, a conductive paste, a solder resist, a heat conductive material, and the like.

Claims

1. A latent curing agent for epoxy resins, which comprises a curing agent (A) for epoxy resins and a resin coating the curing agent (A),

the resin coating the curing agent (A) for epoxy resin has a main chain structure composed of a structure (1) having 2 nitrogen atoms, wherein linear or cyclic low molecular aliphatic hydrocarbon groups having no ester bond are present between the 2 nitrogen atoms, at least one nitrogen atom of the structure (1) forms a urea bond, and the curing agent (A) for epoxy resin is coated with a film (c1) obtained by reacting an isocyanate component (b1) containing 1 to 95 mass% of a low molecular 2-functional aliphatic isocyanate compound with an active hydrogen compound (b 2).

2. The latent curing agent for epoxy resins according to claim 1, which comprises a curing agent (A) for epoxy resins and a resin coating the curing agent (A),

the resin coating the curing agent (A) for epoxy resin has a main chain structure composed of a structure (1) having 2 nitrogen atoms, wherein a linear or cyclic low molecular aliphatic hydrocarbon group containing no oxygen atom other than an oxygen atom forming a urethane bond is present between the 2 nitrogen atoms, and at least one nitrogen atom of the structure (1) forms a urea bond.

3. The latent curing agent for epoxy resins according to claim 1, wherein the isocyanate component (b1) comprises 1 to 95% by mass of the low molecular 2-functional aliphatic isocyanate compound (b1-1) and 5 to 99% by mass of the aromatic isocyanate compound (b 1-2).

4. The latent curing agent for epoxy resins according to claim 2, wherein the isocyanate component (b1) comprises 1 to 95% by mass of the low molecular 2-functional aliphatic isocyanate compound (b1-1) and 5 to 99% by mass of the aromatic isocyanate compound (b 1-2).

5. The latent curing agent for epoxy resins according to claim 1, wherein the coating film is

(c1) Has an absorption wave number of 1630cm^-1～1680cm^-1The infrared ray-binding group (x) and the absorption wave number of 1680 to 1725cm^-1The infrared binding group (y) of (2).

6. The latent curing agent for epoxy resins according to claim 1, wherein the curing agent (A) for epoxy resins comprises an amine-based curing agent comprising an amine adduct (a) and a low-molecular-weight amine compound (e) as main components.

7. The latent curing agent for epoxy resins according to any of claims 1 to 6, wherein the amine adduct (a) is obtained by reacting an epoxy resin (a1) with an amine compound (a 2).

8. The latent curing agent for epoxy resins according to claim 6, wherein the low-molecular amine compound (e) is an imidazole.

9. A microcapsule-type curing agent (D) for epoxy resin, which comprises the latent curing agent for epoxy resin according to any one of claims 1 to 8 as a core, is coated with a shell (C2) formed by the reaction of the curing agent (A) for epoxy resin and an epoxy resin (C), and has an absorption wave number of 1630 to 1680cm at least on the surface^-1The infrared ray-binding group (x) and the absorption wave number of 1680 to 1725cm^-1The infrared binding group (y) of (2).

10. A masterbatch-type curing agent composition (F) for epoxy resin, which is characterized by comprising 10 to 50000 parts by weight of an epoxy resin (E) per 100 parts by weight of the latent curing agent for epoxy resin according to any one of claims 1 to 8 and/or the microcapsule-type curing agent for epoxy resin (D) according to claim 9.

11. The curing agent composition (F) for a masterbatch-type epoxy resin according to claim 10, wherein the total chlorine content of the curing agent composition for a masterbatch-type epoxy resin is 2500ppm or less.

12. The curing agent composition (F) for masterbatch-type epoxy resins according to claim 10 or 11, wherein the total chlorine content of the epoxy resin (E) is 2500ppm or less.

13. The curing agent composition (F) for masterbatch-type epoxy resins according to claim 10, wherein the content of diol terminal impurities in the epoxy resin (E) is 0.001 to 30% by mass based on the basic structural component of the epoxy resin (E).

14. An epoxy resin composition comprising the latent curing agent for epoxy resins according to any one of claims 1 to 8, the microcapsule-type curing agent (D) for epoxy resins according to claim 9, the masterbatch-type curing agent composition for epoxy resins according to any one of claims 10 to 13, and a cyclic borate compound (L) in combination.

15. The epoxy resin composition according to claim 14, wherein the cyclic borate compound (L) is 2, 2' -oxybis (5, 5-dimethyl-1, 3, 2-dioxaborane).

16. The epoxy resin composition according to claim 14 or 15, wherein the amount of the cyclic boronic acid ester compound (L) according to claim 14 or 15 is 0.001 to 10 parts by mass based on 100 parts by mass of the total amount of the latent curing agent for epoxy resin according to any one of claims 1 to 8, the microcapsule-type curing agent (D) for epoxy resin according to claim 9, and/or the masterbatch-type curing agent composition for epoxy resin (F) according to any one of claims 10 to 13.

17. An epoxy resin composition comprising, as a main component, 0.001 to 1000 parts by mass of the latent curing agent for epoxy resins according to any one of claims 1 to 8, the microcapsule-type curing agent (D) according to claim 9, and/or the masterbatch-type curing agent composition (F) according to any one of claims 10 to 13, per 100 parts by mass of an epoxy resin (J).

18. An epoxy resin composition, wherein 0.001 to 10 parts by mass of a cyclic boric acid ester compound (L) is blended per 100 parts by mass of the epoxy resin composition according to claim 17.

19. The epoxy resin composition according to claim 18, wherein the cyclic borate compound (L) is 2, 2' -oxybis (5, 5-dimethyl-1, 3, 2-dioxaborane).

20. An epoxy resin composition comprising 1 to 200 parts by mass of at least one curing agent (K) selected from the group consisting of acid anhydrides, phenols, hydrazides and guanidines, and 0.1 to 200 parts by mass of the latent curing agent for epoxy resins according to any one of claims 1 to 8, the microcapsule-type curing agent (D) for epoxy resins according to claim 9, and the masterbatch-type curing agent composition (F) according to any one of claims 10 to 13, as the main component.

21. An epoxy resin composition, wherein 0.001 to 10 parts by mass of a cyclic boric acid ester compound (L) is blended per 100 parts by mass of the epoxy resin composition according to claim 20.

22. The epoxy resin composition according to claim 21, wherein the cyclic borate compound (L) is 2, 2' -oxybis (5, 5-dimethyl-1, 3, 2-dioxaborane).

23. A paste composition comprising the curing agent composition for a masterbatch-type epoxy resin according to any one of claims 10 to 13 and/or the epoxy resin composition according to any one of claims 14 to 22.

24. A film-like composition comprising the curing agent composition for a masterbatch-type epoxy resin according to any one of claims 10 to 13 and/or the epoxy resin composition according to any one of claims 14 to 22.

25. An adhesive comprising the epoxy resin composition according to any one of claims 14 to 22.

26. An adhesive paste comprising the epoxy resin composition according to any one of claims 14 to 22.

27. An adhesive film comprising the epoxy resin composition according to any one of claims 14 to 22.

28. An electrically conductive material comprising the epoxy resin composition according to any one of claims 14 to 22.

29. An anisotropic conductive material comprising the epoxy resin composition according to any one of claims 14 to 22.

30. An anisotropic conductive film comprising the epoxy resin composition according to any one of claims 14 to 22.

31. An insulating material comprising the epoxy resin composition according to any one of claims 14 to 22.

32. A sealing material comprising the epoxy resin composition according to any one of claims 14 to 22.

33. A coating material comprising the epoxy resin composition according to any one of claims 14 to 22.

34. A coating composition comprising the epoxy resin composition according to any one of claims 14 to 22.

35. A prepreg comprising the epoxy resin composition according to any one of claims 14 to 22.

36. A thermally conductive material comprising the epoxy resin composition according to any one of claims 14 to 22.