Latent curing agent and one-component epoxy resin composition

Abstract

An object of the present invention is to provide an aliphatic amine curing agent or an alicyclic amine curing agent that exhibits high storage stability. [Solution] The above-mentioned problems can be solved by a latent curing agent of the present invention, which is obtained by adding an epoxy compound represented by any one of general formulas (1), (2), (3), (4), and (5) to an aliphatic amine compound or an alicyclic amine compound.

Description

[Technical Field]

[0001] The present invention relates to a latent curing agent and a one-component epoxy resin composition. According to the present invention, a latent curing agent exhibiting excellent storage stability can be obtained. [Background technology]

[0002] Amine compounds are widely used as curing agents and curing catalysts for epoxy resins. Conventional amine curing agents are primarily liquid, and two-component systems, in which epoxy resin and curing agent are mixed, are the norm. Amine curing agents are broadly classified into aliphatic amines, aromatic amines, tertiary amines, and imidazoles. Aliphatic amines and alicyclic amines, in particular, contain active hydrogen and are known to be able to cure at low temperatures when formulated with epoxy resins. However, most conventional aliphatic amines and alicyclic amines are liquid, and their use in epoxy resin formulations is short, solidifying within a few hours at room temperature. Therefore, aliphatic amines and alicyclic amines that can be formulated as one-component systems are desirable. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 7-5708 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, epoxy adduct modification of aliphatic amines or alicyclic amines is widely carried out, and modification with bisphenol A epoxy resin is particularly widely used (Patent Document 1). However, modification with only bisphenol A epoxy resin makes it difficult to increase the softening point of the resulting resin, and even if the resulting resin is pulverized, it often re-aggregates at room temperature. Therefore, an object of the present invention is to provide an aliphatic amine curing agent or an alicyclic amine curing agent that exhibits high storage stability. [Means for solving the problem]

[0005] The present inventors have conducted extensive research into aliphatic amine curing agents or alicyclic amine curing agents that exhibit high storage stability, and as a result have surprisingly found that an aliphatic amine curing agent or alicyclic amine curing agent that exhibits high storage stability can be obtained by adding an epoxy compound having a specific structure to an aliphatic amine compound or alicyclic amine compound. The present invention is based on this finding. Therefore, the present invention provides [1] General formula (1), (2), (3), (4), or (5): [ka] [ka] [ka] [ka] [ka] (wherein X is a group represented by general formula (6), (7), or (8): [ka] [ka] [ka] (In the formula, R 2 is a hydrogen atom or -AND 2 epoxy groups, R 3 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Y is a group represented by the general formula (9): [ka] (R in the formula 4 teeth, -AND 2 epoxy groups, R 3 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Z is a group represented by the general formula (10): [ka] (wherein the two bonds may be bonded to any carbon atom in the structure of general formula (10), and two bonds may be bonded to one carbon atom), R 1 is a single bond or an alkylene group having 1 to 3 carbon atoms, and R bonded to X 1 may be attached to either of the two ring structures of X; n is 1 to 15, m is 0 to 15, One R at the end of X 2 teeth -AND 2 epoxy groups, and hydrogen atoms are bonded to the terminal bonds of X and Y present at the terminals, and the two R 2 teeth -AND 2 epoxy groups, and In the repeating unit -AND 2) The number of epoxy groups is 1 or 2 and an aliphatic amine compound or an alicyclic amine compound, [2] The latent compound according to [1], wherein the epoxy compound is selected from the group consisting of epoxy compounds represented by the following formula: [ka] (In the formula, oは0~14して、 l is 1 to 15.) [3] A one-component epoxy resin composition comprising the latent curing agent according to [1] or [2] and an epoxy resin. [4] A cured epoxy resin product obtained by heating the one-component epoxy resin composition according to [3], and [5] An aliphatic amine compound or an alicyclic amine compound, (1), (2), (3), (4), or (5): [ka] [ka] [ka] [ka] [ka] (wherein X is a group represented by general formula (6), (7), or (8): [ka] [ka] [ka] (In the formula, R 2 is a hydrogen atom or -AND 2 epoxy groups, R 3 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Y is a group represented by the general formula (9): [ka] (R in the formula 4 teeth, -AND 2 epoxy groups, R 3 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Z is a group represented by the general formula (10): [ka] (wherein the two bonds may be bonded to any carbon atom in the structure of general formula (10), and two bonds may be bonded to one carbon atom), R 1 is a single bond or an alkylene group having 1 to 3 carbon atoms, and R bonded to X 1may be attached to either of the two ring structures of X; n is 1 to 15, m is 0 to 15, One R at the end of X 2 teeth -AND 2 epoxy groups, and hydrogen atoms are bonded to the terminal bonds of X and Y present at the terminals, and the two R 2 teeth -AND 2 epoxy groups, and In the repeating unit -AND 2) The number of epoxy groups is 1 or 2 Adding any one of the epoxy compounds represented by the formula: A method for producing a latent curing agent; Regarding. [Effects of the Invention]

[0006] The latent curing agent of the present invention can exhibit excellent storage stability. DETAILED DESCRIPTION OF THE INVENTION

[0007] [1] Latent hardener The latent curing agent of the present invention is represented by the general formula (1), (2), (3), (4), or (5): [ka] [ka] [ka] [ka] [ka] and an aliphatic amine compound or an alicyclic amine compound.

[0008] The addition of an epoxy compound with an aliphatic amine compound or an alicyclic amine compound is not limited, but may be carried out by reacting an -NH group or =NH group of an aliphatic amine compound with an epoxy group (CH 2 (O)CH-) reacts with -NH-CH 2 -CH(OH)- or =N-CH 2 It means forming a -CH(OH)- bond.

[0009] Epoxy compounds The epoxy compound is not particularly limited as long as it has any of the structures of general formulas (1) to (5). By having the structure, the epoxy compound can form a rigid skeleton. By forming a rigid skeleton, it is possible to increase the softening point of the aliphatic amine compound or alicyclic amine compound, and to improve the storage stability of the latent curing agent.

[0010] X of the epoxy compound is represented by general formula (6), (7), or (8): [ka] [ka] [ka] It is a group represented by the following formula:

[0011] R 2 is a hydrogen atom or -AND 2 epoxy group. When X is present at the terminal of the epoxy compound, at least one R 2 teeth -AND 2 epoxy groups. The two R of X in general formula (4) 2 teeth -AND 2 epoxy groups. R 3 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The alkyl group having 1 to 3 carbon atoms is specifically a methyl group, an ethyl group, or a propyl group. R 3is preferably a hydrogen atom or a methyl group.

[0012] Y is a group represented by the general formula (9): [ka] It is a group represented by the following formula: R 4 teeth, -AND 2 epoxy groups, R 3 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The alkyl group having 1 to 3 carbon atoms is specifically a methyl group, an ethyl group, or a propyl group. R 3 is preferably a hydrogen atom or a methyl group.

[0013] Z is a group represented by the general formula (10): [ka] The two bonds can be bonded to any carbon atom in the above structure. Specifically, they may be bonded to carbon atoms in two benzene rings. They may also be bonded to carbon atoms forming a cyclopentane ring, or two bonds may be bonded to one carbon atom.

[0014] R 1 is a single bond or an alkylene group having 1 to 3 carbon atoms. The alkylene group having 1 to 3 carbon atoms is specifically a methylene group, an ethylene group, or a propyl group. 1 is preferably a single bond or a methylene group. 1 may be attached to either of the two ring structures of X.

[0015] n is 1 to 15, preferably 1 to 10, more preferably 1 to 8, even more preferably 1 to 5, even more preferably 1 to 3, even more preferably 1 or 2, and most preferably 1. The epoxy compound represented by general formula (1) is a polymer, and may be a polymer with a single n number, or a mixture of polymers with n numbers of 1 to 15. In the case of a mixture, n in general formula (1) means the average number of repeating units. In the case of a single polymer, n is an integer. m is 0 to 15, preferably 0 to 10, more preferably 0 to 8, even more preferably 0 to 5, even more preferably 0 to 3, even more preferably 0 to 2, and even more preferably 0 or 1. The epoxy compound represented by general formula (2) is a polymer, and may be a polymer with a single m number, or a mixture of polymers with m numbers of 0 to 15. In the case of a mixture, m in general formula (1) means the average number of repetitions. In the case of a single polymer, m is an integer.

[0016] (end) One R at the end of X 2 teeth -AND 2 epoxy groups. A hydrogen atom is bonded to the terminal bond of the terminal X and Y. In other words, the terminal X and Y are monovalent groups, not divalent groups.

[0017] (epoxy group) The number of epoxy groups in the epoxy compound is not particularly limited as long as the effects of the present invention can be obtained, but for example, the upper limit is 5 or less, preferably 4 or less, and more preferably 3 or less. The lower limit is not particularly limited as long as the effects of the present invention can be obtained, but is preferably 2 or more. When the number is within the above range, gelation during synthesis of the aliphatic amine or alicyclic amine-epoxy adduct can be prevented, and a good epoxy resin curing agent can be obtained.

[0018] (repeating unit) In the repeating unit of general formula (1) or (2), -AND The number of epoxy groups is one or two.

[0019] (average number of epoxy groups) The epoxy compound represented by general formula (1) or (2) is a polymer, and as described above, it may be a mixture of polymers in which n is 1 to 15, or a mixture of polymers in which m is 0 to 15. In the case of a mixture, the average number of epoxy groups contained in the epoxy compound represented by general formula (1) or (2) is, for example, 5 or less at the upper limit, preferably 4 or less, and more preferably 3 or less. The lower limit is not particularly limited as long as the effects of the present invention can be obtained, but is preferably 2 or more. By keeping the number within the above range, gelation of the epoxy resin adduct can be prevented and a good epoxy resin curing agent can be obtained.

[0020] The epoxy compound used in the present invention is not limited, but specific examples include compounds represented by the following formula: [ka] During the ceremony, oは0~14して、 l is 1 to 15. oは0~14して、 It is preferably 0 to 10, more preferably 0 to 8, even more preferably 0 to 5, even more preferably 0 to 3, even more preferably 0 to 2, and even more preferably 0 or 1. The epoxy compound represented by the above formula is a polymer, and m o may be a single polymer, o The number of 0~14 In the case of a mixture, the polymer may be a mixture of polymers of the above formula. o means the average number of repeats. In the case of a single polymer, o is an integer. l is 1 to 15, preferably 1 to 10, more preferably 1 to 8, even more preferably 1 to 5, even more preferably 1 to 3, even more preferably 1 or 2, and most preferably 1. The epoxy compound represented by the above formula is a polymer, and may be a single polymer with l as a number, or a mixture of polymers with l as a number of 1 to 15. In the case of a mixture, l in the above formula means the average number of repeating units. In the case of a single polymer, l is an integer.

[0021] Aliphatic amine compounds The aliphatic amine compound is not particularly limited as long as the effects of the present invention can be obtained. Examples of the aliphatic amine compound include ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, diethylenetriamine, dipropylenetriamine, triethylenetetramine (TETA), tripropylenetetramine, tetraethylenepentamine, hexamethylenediamine, iminobispropylamine, bis(hexamethylene)triamine, 1,3,6-trisaminomethylhexane, trimethylhexamethylenediamine, polyetherdiamine, diethylaminopropylamine, metaxylylenediamine (MXDA), 1,3-bisaminomethylcyclohexane (1,3-BAC), 1,4-bisaminomethylcyclohexane, bis(aminomethyl)norbornane, N-aminoethylpiperazine, and 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro(5.5)undecane.

[0022] Alicyclic amine compounds The alicyclic amine compound is not particularly limited as long as the effects of the present invention can be obtained, but examples thereof include menthene diamine, 1,4-cyclohexane diamine, isophorone diamine, bis(4-aminocyclohexyl)methane, 2,2'-dimethyl-4,4'-methylenebis(cyclohexylamine), and 1,2-diaminocyclohexane.

[0023] The contents of the aliphatic amine compound or alicyclic amine compound and the epoxy compound contained in the latent curing agent of the present invention are not particularly limited, but the amount of the epoxy compound relative to 1 mole of the aliphatic amine compound or alicyclic amine compound is 0.5 to 2.0 equivalents, more preferably 0.8 to 1.7 equivalents, and even more preferably 1.0 to 1.5 equivalents.

[0024] (softening point) The composition in which an epoxy compound is added to the aliphatic amine compound or alicyclic amine compound is a solid composition. The softening point of the solid composition is not particularly limited as long as the solid composition can be pulverized into powder, but the upper limit is, for example, 150°C or lower, in one embodiment 140°C or lower, and in one embodiment 135°C or lower. The lower limit is, for example, 90°C or higher, in one embodiment 95°C or higher, and in one embodiment 100°C or higher. The upper and lower limits can be combined as appropriate.

[0025] [2] One-component epoxy resin composition The one-component epoxy resin composition of the present invention contains the latent curing agent and an epoxy resin.

[0026] 《Epoxy resin》 The epoxy resin contained in the one-component epoxy resin composition of the present invention is an epoxy resin having an average of one or more epoxy groups per molecule, preferably an epoxy resin having an average of more than one epoxy group. The number of epoxy groups is not particularly limited as long as it is an average of one or more, but is preferably two or more. The upper limit of the epoxy groups is not particularly limited, taking into account the effect of the epoxy resin in the epoxy resin composition. Note that "average" refers to the average number of epoxy groups per molecule when two or more epoxy resins are mixed. Specific examples of epoxy resins include epoxy compounds (polyglycidyl ethers) of mononuclear polyhydric phenol compounds, epoxy compounds (polyglycidyl ethers) of polynuclear polyhydric phenol compounds, epoxy compounds (polyglycidyl ethers) of polyhydric alcohols, epoxy compounds (polyglycidyl ether esters) of hydroxycarboxylic acids, epoxy compounds (polyglycidyl esters) of aliphatic, aromatic, or alicyclic polybasic acids, epoxy compounds (glycidyl ether esters) of hydroxycarboxylic acids, epoxy compounds (glycidyl esters) of polycarboxylic acids, epoxy compounds (glycidyl aminoglycidyl ethers) of aminophenols, epoxy compounds (glycidyl amines) of polyvalent amines, and other epoxy compounds.

[0027] More specific examples of the mononuclear polyhydric phenol compound include catechol, resorcinol, hydroquinone, and halogen (for example, chlorine, bromine) derivatives thereof.

[0028] More specific examples of the polynuclear polyhydric phenol compound include bisphenol F, bisphenol A, bisphenol S, bisphenol AD, tetramethylbisphenol F, tetramethylbisphenol A, or halogen derivatives thereof; naphthol, biphenol, bixylenol, bisresorcinol, trihydroxybiphenyl, tetrahydroxyphenylethane, phenol novolac, cresol novolac, terpene phenol, phenolated dicyclopentadiene, or halogen derivatives thereof.

[0029] More specific examples of the polyhydric alcohols include glycerin, neopentyl glycol, ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, polyethylene glycol, polypropylene glycol, thiodiglycol, trimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol, and bisphenol A-ethylene oxide or propylene oxide adducts.

[0030] More specific examples of the hydroxycarboxylic acids include p-hydroxybenzoic acid and β-hydroxynaphthoic acid.

[0031] More specific examples of the polycarboxylic acids include phthalic acid, methylphthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, decanedioic acid, dodecanedioic acid, tetradecanedioic acid, octadecanedioic acid, and polymerized fatty acids.

[0032] More specific examples of the aminophenols include p-aminophenol and p-aminoalkylphenol.

[0033] More specific examples of the polyvalent amines include aniline, o-toluidine, tribromoaniline, m-xylylenediamine, 1,2-diaminocyclohexane, 1,3-bisaminomethylcyclohexane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodicyclohexylmethane, 2,2'-dimethyl-4,4'-4,4'-diaminodicyclohexylmethane, and diaminodiphenyl sulfone.

[0034] More specific examples of the other epoxy compounds include epoxidized polyolefin, epoxidized polybutadiene, epoxidized soybean oil, glycidyl hydantoin, di- or triglycidyl isocyanurate, vinylcyclohexene diepoxide, dicyclopentadiene diepoxide, and 3,4-epoxycyclohexyl-3,4-epoxycyclohexane carboxylate.

[0035] Among the epoxy resins exemplified above, it is particularly preferable to use bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, biphenyl epoxy resin, naphthol epoxy resin, or diaminodiphenylmethane epoxy resin, because when the epoxy resin composition of the present invention is cured, the cured product has excellent heat resistance, electrical properties such as insulating properties, adhesiveness, etc. The above epoxy resins can be used alone or in combination of two or more.

[0036] As the epoxy resin in the epoxy resin composition of the present invention, a monofunctional epoxy compound can be used in combination, provided that the effects of the present invention are not impaired. Examples include butyl glycidyl ether, phenyl glycidyl ether, higher alcohol glycidyl ether, benzoic acid glycidyl ester, branched fatty acid glycidyl ester (Cardura E; manufactured by Momentive Performance Materials), and styrene oxide. Generally, these monofunctional epoxy compounds have low viscosity, which is advantageous, particularly in terms of handling the epoxy resin composition. However, since they can reduce the mechanical properties and heat resistance (glass transition temperature) of the final epoxy resin cured product, their use amount should be kept as small as possible. Furthermore, the monofunctional epoxy resins can be used alone or in combination of two or more types.

[0037] <Other Components in Epoxy Resin Composition> To the epoxy resin composition of the present invention, various additives may be added as needed, within the range in which the effects of the present invention can be obtained, such as surfactants, flow improvers, thixotropy-imparting agents, extender pigments and other extender agents, coloring pigments or dyes for coloring, anti-rust pigments or anti-rust agents, other resin powders, waxes, etc. Furthermore, solvents for lowering the viscosity of the epoxy resin composition may be added, such as aromatic solvents such as toluene and xylene; ketone solvents such as dimethyl ketone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; alcohol solvents such as methanol, ethanol and isopropyl alcohol; glycol or glycol ester solvents such as methoxypropanol and methoxypropyl acetate, etc.

[0038] In the one-component epoxy resin composition of the present invention, the weight ratio or molar ratio of the latent curing agent to the epoxy resin is not particularly limited, as long as the one-component epoxy resin composition can be cured to a desired gelation degree. That is, curable epoxy resin compositions are used for various purposes such as adhesives, paints, coatings, sealing, and impregnation, and the desired cured state, curing time, and use conditions vary depending on the purpose, so the weight ratio or molar ratio of the latent curing agent to the epoxy resin having an average of more than one epoxy group per molecule in the one-component epoxy resin composition can be appropriately selected. However, the content of the epoxy resin and the latent curing agent contained in the one-component epoxy resin composition of the present invention is preferably 2 to 70 parts by weight, more preferably 4 to 60 parts by weight, and most preferably 5 to 50 parts by weight of the latent curing agent relative to 100 parts by weight of the epoxide compound.

[0039] The one-component curable epoxy resin composition of the present invention is a thermosetting epoxy resin composition that does not cure at room temperature (e.g., 0°C to 40°C), but cures rapidly when heated (e.g., 80°C to 200°C), and can be used for adhesives, painting, coating, sealing, and impregnation.

[0040] <<Cured epoxy resin>> The cured epoxy resin product of the present invention can be obtained by heating the one-component epoxy resin composition. Specific examples of the cured product include an adhesive, a painted surface, a coated material, a sealed material, and an impregnated material.

[0041] [3] Manufacturing method of latent hardener The method for producing the latent curing agent of the present invention comprises adding (1), (2), (3), (4), or (5) to an aliphatic amine compound or an alicyclic amine compound: [ka] [ka] [ka] [ka] [ka] (wherein X is a group represented by general formula (6), (7), or (8): [ka] [ka] [ka] (In the formula, R 2 is a hydrogen atom or -AND 2 epoxy groups, R 3 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Y is a group represented by the general formula (9): [ka] (R in the formula 4 teeth, -AND 2 epoxy groups, R 3is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Z is a group represented by the general formula (10): [ka] (wherein the two bonds may be bonded to any carbon atom in the structure of general formula (10), and two bonds may be bonded to one carbon atom), R 1 is a single bond or an alkylene group having 1 to 3 carbon atoms, and R bonded to X 1 may be attached to either of the two ring structures of X; n is 1 to 15, m is 0 to 15, One R at the end of X 2 teeth -AND 2 epoxy groups, and hydrogen atoms are bonded to the terminal bonds of X and Y present at the terminals, and the two R 2 teeth -AND 2 epoxy groups, and In the repeating unit -AND 2) The number of epoxy groups is 1 or 2 The epoxy compound represented by the formula (I) is added to the resin.

[0042] The "aliphatic amine compound or alicyclic amine compound" and "epoxy compound" in the method for producing the latent curing agent of the present invention can be any of those described above as the "latent curing agent" without any limitation. The weight ratio or molar ratio of the epoxy compound to the aliphatic amine compound or alicyclic amine compound in the addition step is not limited, but is preferably 0.5 to 2.0 equivalents, more preferably 0.8 to 1.7 equivalents, and even more preferably 1.0 to 1.5 equivalents, per mole of the aliphatic amine compound or alicyclic amine compound.

[0043] The addition reaction is not particularly limited, but may be a reaction between an -NH group or =NH group of an aliphatic amine compound or an alicyclic amine compound and an epoxy group (CH 2(O)CH-) reacts with -NH-CH 2 -CH(OH)- or =N-CH 2 It means forming a -CH(OH)- bond. The -NH2 group or =NH group of an aliphatic amine compound or alicyclic amine compound and the epoxy group (CH 2 Although it is not necessary for all groups to react with (O)CH—), typically 1.0 to 1.5 equivalents of epoxy are used per mole of amino groups. Therefore, basically, all epoxy groups are consumed by the addition reaction.

[0044] The reaction temperature is not particularly limited, but is, for example, 60 to 150°C, and preferably 80 to 120°C.

[0045] 《Action》 The mechanism by which the storage stability of the latent curing agent of the present invention is improved has not been analyzed in detail, but can be assumed as follows. However, the present invention is not limited to the following assumption. The epoxy compound used in the latent curing agent has a rigid structure. This is thought to improve the softening point of the latent curing agent of the present invention and increase the glass transition temperature of the latent curing agent resin. It is presumed that the increase in Tg of the curing agent resin reduces the amount of low-molecular-weight components that dissolve from the surface of the curing agent particles into the epoxy resin in the epoxy resin formulation, resulting in improved storage stability. [Example]

[0046] The present invention will be specifically described below with reference to examples, but these examples are not intended to limit the scope of the present invention.

[0047] Example 1 In this example, a latent curing agent was prepared using ethylenediamine (EDA) as the aliphatic amine and XD-1000 (dicyclopentadiene-phenol type epoxy resin, epoxy equivalent: 250 g / eq, manufactured by Nippon Kayaku Co., Ltd.) as the epoxy compound. Specifically, 90 parts by weight of EDA and 90 parts of a 1:1 (by weight) mixed solvent of xylene and 2-propanol were added to a 1 L four-neck flask equipped with a stirrer and nitrogen inlet tube, and the mixture was heated to 80°C while stirring under a nitrogen stream. After the internal temperature reached 80°C, an epoxy solution containing 250 parts of XD-1000 dissolved in 250 parts of a mixed solvent of xylene and 2-propanol was added dropwise over 2 hours. After the addition was complete, the mixture was stirred while maintaining the temperature at 80°C for 30 minutes, then heated to 200°C, and the pressure was reduced to remove the solvent, yielding a brown solid compound. This was then finely pulverized using a jet mill to obtain a latent curing agent with a particle size of approximately 5 μm. 20 parts of the obtained latent curing agent were mixed with 100 parts of an epoxy resin (jER828 (Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent: 190 g / eq)), and the storage stability and gel time were measured. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0048] (Softening point measurement) The softening point of the obtained solid compound was measured in accordance with JIS K 7234.

[0049] (Evaluation of crushing) The crushed powder was stored overnight at room temperature, and the state of aggregation was checked the next day. Evaluation was made according to the following criteria. 〇: No change in status ×: Unusable due to aggregation

[0050] (Evaluation of curability) The gel time of the obtained one-component epoxy resin composition was measured using a Yasuda gel timer. Specifically, 2.0 g of the epoxy resin composition was placed in a test tube as a sample and maintained at a predetermined temperature in an oil bath. A glass rod was inserted into the sample and stirred by rotating it. The time when stirring became impossible was recorded as the gel time. The evaluation was based on the following criteria. ◎: Gel formation within 5 minutes 〇: Gel within 6 minutes ×: No gelation in 6 minutes

[0051] (Storage stability) The initial viscosity of a formulation was measured by mixing 20 parts of the resulting latent hardener with 100 parts of epoxy resin (jER828). The formulation was stored at 40°C, and the change in viscosity over time was measured. The viscosity increase rate was calculated from the ratio. The evaluation criteria for storage stability in Table 1 are as follows: ◎: Viscosity increase rate is less than double in one week at 40℃ Yes: At 40°C, the viscosity rate doubles or more in one week (the viscosity rate does not double in one day) △: At 40℃, the viscosity increased by more than double in one day ×: Gelled in 1 day at 40°C

[0052] Example 2 In this example, the procedure of Example 1 was repeated, except that diethylenetriamine (DETA) was used in place of EDA as the aliphatic amine in the amount shown in Table 1. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0053] Example 3 In this example, the procedure of Example 1 was repeated, except that N,N'-dimethylaminopropylamine (DMAPA) was used as the aliphatic amine instead of EDA in the amount shown in Table 1. The composition was as shown in Table 1. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0054] Example 4 In this example, the procedure of Example 1 was repeated, except that N-aminoethylpiperazine (N-AEP) was used as the aliphatic amine instead of EDA in the amount shown in Table 1. The composition was as shown in Table 1. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0055] Example 5 In this example, the procedure of Example 1 was repeated, except that metaxylylenediamine (MXDA) was used as the aliphatic amine instead of EDA in the amount shown in Table 1. The composition was as shown in Table 1. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0056] Example 6 In this example, the procedure of Example 1 was repeated, except that isophoronediamine (IPDA) was used as the alicyclic amine instead of EDA in the amount shown in Table 1. The composition was as shown in Table 1. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0057] Example 7 In this example, the procedure of Example 1 was repeated, except that EDA was used as the aliphatic amine and NC-7000L (naphthol-cresol novolac epoxy resin, epoxy equivalent: 230 g / eq, manufactured by Nippon Kayaku Co., Ltd.) was used as the epoxy compound instead of XD-1000, in the amounts shown in Table 1. The composition is shown in Table 1. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0058] Example 8 In this example, the procedure of Example 1 was repeated, except that EDA was used as the aliphatic amine and NC-3000H (biphenyl-novolac epoxy resin, epoxy equivalent: 290 g / eq, manufactured by Nippon Kayaku Co., Ltd.) was used as the epoxy compound instead of XD-1000, in the amounts shown in Table 1. The composition is shown in Table 1. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0059] Example 9 In this example, the procedure of Example 1 was repeated, except that EDA was used as the aliphatic amine and HP-4700 (manufactured by DIC Corporation, naphthalene-type epoxy resin, epoxy equivalent: 165 g / eq) was used as the epoxy compound in the amounts shown in Table 1. The composition is shown in Table 1. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0060] Example 10 In this example, the procedure of Example 1 was repeated, except that EDA was used as the aliphatic amine and HP-4770 (manufactured by DIC Corporation, naphthalene-type epoxy resin, epoxy equivalent: 204 g / eq) was used as the epoxy compound in the amounts shown in Table 1. The composition is shown in Table 1. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0061] Example 11 In this example, the procedure of Example 1 was repeated, except that EDA was used as the aliphatic amine and OGSOL PG-100 (fluorene-type epoxy resin, epoxy equivalent: 254 g / eq, manufactured by Osaka Gas Chemicals Co., Ltd.) was used as the epoxy compound in the amounts shown in Table 1. The composition is shown in Table 1. As shown in Table 1, the one-component epoxy resin composition using the curing agent of the present invention exhibited excellent curability at 80°C and excellent storage stability at 40°C.

[0062] Comparative Example 1 In this example, the procedure of Example 1 was repeated except that jER828 was used instead of XD-1000. The composition is shown in Table 1. As shown in Table 1, the obtained curing agent had a low softening point of the curing agent resin, and aggregated at room temperature, so that powder could not be obtained.

[0063] Comparative Example 2 In this example, the procedure of Comparative Example 1 was repeated, except that DMAPA was used as the aliphatic amine instead of EDA. The composition is shown in Table 1. As shown in Table 1, the obtained curing agent had a low softening point of the curing agent resin, and aggregated at room temperature, so that powder could not be obtained.

[0064] Comparative Example 3 In this example, the procedure of Comparative Example 1 was repeated, except that MXDA was used as the aliphatic amine instead of EDA. The composition is shown in Table 1. As shown in Table 1, the obtained curing agent had a low softening point of the curing agent resin, and aggregated at room temperature, so that powder could not be obtained.

[0065] Comparative Example 4 In this example, the procedure of Comparative Example 1 was repeated, except that IPDA was used as the aliphatic amine instead of EDA. The composition is shown in Table 1. As shown in Table 1, the obtained curing agent had a low softening point of the curing agent resin, and aggregated at room temperature, so that powder could not be obtained.

[0066] Comparative Example 5 In this example, a one-component epoxy resin composition was prepared using FXR-1020 manufactured by T&K TOKA Corporation as an amine adduct-type latent curing agent, and the procedure of Example 1 was repeated. As shown in Table 1, the one-component epoxy resin composition using this curing agent had excellent storage stability, but poor curing properties at 80°C.

[0067] [Table 1] [Industrial Applicability]

[0068] The latent curing agent of the present invention can be used in a one-component epoxy resin composition, and the one-component epoxy resin composition of the present invention can be used as a thermosetting epoxy resin composition for adhesives, paints, etc.

Claims

1. General formula (1), (2), (3), (4), or (5): 【Chemical 1】 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 【Chemistry 5】 (wherein X represents general formula (6), (7), or (8): 【Chemistry 6】 【Chemistry 7】 【Chemistry 8】 (In the formula, R ２ is a hydrogen atom or an —OCH 2 epoxy group, and R ３ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Y is a group represented by the general formula (9): 【Chemistry 9】 (In the formula R ４ is an —OCH 2 epoxy group, and R ３ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Z is a group represented by the general formula (10): 【Chemistry 10】 (wherein the two bonds may be bonded to any carbon atom in the structure of general formula (10), or two bonds may be bonded to one carbon atom), R １ is a single bond or an alkylene group having 1 to 3 carbon atoms, and R １ may be attached to either of the two ring structures of X; n is 1 to 15, m is 0 to 15, One R of X at the terminal ２ is an -OCH2 epoxy group, and hydrogen atoms are bonded to the terminal bonds of X and Y at the terminals, and the two R ２ is an —OCH2 epoxy group, and The number of -OCH2 epoxy groups in the repeating unit is 1 or 2. and an aliphatic amine compound or an alicyclic amine compound.

2. 2. The latent compound according to claim 1, wherein the epoxy compound is selected from the group consisting of epoxy compounds represented by the following formula: 【Chemistry 11】 (wherein o is 0 to 14, and l is 1 to 15.)

3. A one-component epoxy resin composition comprising the latent curing agent according to claim 1 or 2 and an epoxy resin.

4. A cured epoxy resin product obtained by heating the one-component epoxy resin composition according to claim 3.

5. An aliphatic amine compound or an alicyclic amine compound is added with (1), (2), (3), (4), or (5): 【Chemistry 12】 【Chemistry 13】 【Chemistry 14】 【Chemistry 15】 【Chemistry 16】 (wherein X represents general formula (6), (7), or (8): 【Chemistry 17】 【Chemistry 18】 【Chemistry 19】 (In the formula, R ２ is a hydrogen atom or an —OCH 2 epoxy group, and R ３ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Y is a group represented by the general formula (9): 【Chemistry 20】 (In the formula R ４ is an —OCH 2 epoxy group, and R ３ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Z is a group represented by the general formula (10): 【Chemical Formula 21】 (wherein the two bonds may be bonded to any carbon atom in the structure of general formula (10), or two bonds may be bonded to one carbon atom), R １ is a single bond or an alkylene group having 1 to 3 carbon atoms, and R １ may be attached to either of the two ring structures of X; n is 1 to 15, m is 0 to 15, One R of X at the terminal ２ is an -OCH2 epoxy group, and hydrogen atoms are bonded to the terminal bonds of X and Y at the terminals, and the two R ２ is an —OCH2 epoxy group, and The number of -OCH2 epoxy groups in the repeating unit is 1 or 2. Adding any one of the epoxy compounds represented by the formula: Method for producing latent hardener.

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