Latent curing agent and thermosetting epoxide composition containing the same

Abstract

The object of the present invention is to provide a liquid latent curing agent with high storage stability and a curable epoxide composition using the same. [Solution] The above problem is solved by the present invention by reacting (A) (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, (b) an alcohol having 1 to 20 carbon atoms, and (c) an aliphatic isocyanate compound having one or more isocyanate groups; or The problem can be solved by a latent curing agent comprising (B)(a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, and (c) a compound obtained by reacting an aliphatic isocyanate compound having one isocyanate group.

Description

[Technical Field]

[0001] This invention relates to latent curing agents and thermosetting epoxide compositions. According to this invention, a liquid latent curing agent with excellent stability can be provided. [Background technology]

[0002] Latent curing agents for curable epoxide compositions, which have good storage stability and harden when heated, are in high demand because they reduce the labor required for frequent mixing. Most conventional latent curing agents are solid and are used after being finely ground by crushing or other means (Patent Documents 1 and 2). On the other hand, some latent curing agents are also available in liquid form. For example, 2-ethyl-4-methylimidazole has a melting point of approximately 41°C and can be used in liquid form (Patent Document 3). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Special Publication No. 6-6620 [Patent Document 2] Special Publication No. 6-6621 [Patent Document 3] Japanese Patent Publication No. 2010-168516 [Overview of the project] [Problems that the invention aims to solve]

[0004] Conventional solid latent curing agents had problems such as the cost, time, and transportation of atomizing the curing agent into fine particles. On the other hand, the liquid latent curing agent described in Patent Document 3 solved the above problems, but when used in curable epoxide compositions, it had poor storage stability and its viscosity increased over time. Therefore, the object of the present invention is to provide a liquid latent curing agent with high storage stability and a curable epoxide composition using the same. [Means for solving the problem]

[0005] The inventors of the present invention conducted intensive research on liquid latent curing agents with high storage stability and, surprisingly, discovered that liquid latent curing agents obtained by reacting compounds having an amidine or guanidine skeleton, alcohols, and aliphatic isocyanate compounds exhibit excellent storage stability. This invention is based on these findings. Therefore, the present invention is [1](A)(a) a compound obtained by reacting a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, (b) an alcohol having 1 to 20 carbon atoms, and (c) an aliphatic isocyanate compound having one or more isocyanate groups; or (B) A latent curing agent comprising (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, and (c) an aliphatic isocyanate compound having one isocyanate group; [2] In (A) above, the molar ratio of the aliphatic isocyanate compound to the bicyclic compound having an amidine skeleton or the compound having a guanidine skeleton is 0.01 to 5.0, and the molar ratio of the C1 to C20 alcohol is 0.05 to 10.0, and in (B) above, the molar ratio of the aliphatic isocyanate compound to the bicyclic compound having an amidine skeleton or the compound having a guanidine skeleton is 0.01 to 5.0, the latent curing agent according to [1], [3] In (A) above, with respect to the total amount of latent curing agent, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 1% to 50% by mass, (b) an alcohol having 1 to 20 carbon atoms is 10% to 70% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 10% to 70% by mass, and in (B) above, with respect to the total amount of latent curing agent, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 1% to 50% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 40% to 99% by mass, the latent curing agent according to [1] [4] A method for producing a latent curing agent, characterized by reacting (A) (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, (b) an alcohol having 1 to 20 carbon atoms, and (c) an aliphatic isocyanate compound having one or more isocyanate groups; or (B) (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, and (c) an aliphatic isocyanate compound having one isocyanate group; [5] A method for producing a latent curing agent according to [3], wherein in (A), the molar ratio of the aliphatic isocyanate compound to the bicyclic compound having an amidine skeleton or the compound having a guanidine skeleton is 0.01 to 5.0, and the molar ratio of the alcohol having 1 to 20 carbon atoms is 0.05 to 10.0, and in (B), the molar ratio of the aliphatic isocyanate compound to the bicyclic compound having an amidine skeleton or the compound having a guanidine skeleton is 0.01 to 5.0 [6] The method for producing a latent curing agent according to [4], wherein, with respect to the total amount of the latent curing agent, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 1% to 50% by mass, (b) an alcohol having 1 to 20 carbon atoms is 10% to 70% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 10% to 70% by mass, and, with respect to the total amount of the latent curing agent, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 1% to 50% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 40% to 99% by mass, [7] A thermosetting epoxide composition comprising an epoxide compound having an average of more than one epoxy group in the molecule, and a latent curing agent according to any of [1] to [3] above. [8] The thermosetting epoxide composition according to [7], wherein, with respect to the total amount of the thermosetting epoxide composition, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 0.2% to 10% by mass, (b) an alcohol having 1 to 20 carbon atoms is 2% to 14% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 2% to 14% by mass, and the thermosetting epoxide composition according to [7], wherein, with respect to the total amount of the thermosetting epoxide composition, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 0.2% to 10% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 8% to 19.8% by mass. A cured product obtained by curing the thermosetting epoxide composition described in [9], [7] or [8], A paint comprising the thermosetting epoxide composition described in

[10] [7] or [8], and Adhesives comprising the thermosetting epoxide composition described in

[11] [7] or [8], Regarding. [Effects of the Invention]

[0006] According to the latent curing agent of the present invention, a thermosetting epoxy composition with excellent stability can be provided.

Mode for Carrying Out the Invention

[0007] [1] Latent curing agent The latent curing agent of the present invention contains a compound obtained by reacting (A) (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton (hereinafter sometimes referred to as component a), (b) an alcohol having 1 to 20 carbon atoms (hereinafter sometimes referred to as component b), and (c) an aliphatic isocyanate compound having one or more isocyanate groups (hereinafter sometimes referred to as component c). Further, the latent curing agent of the present invention contains a compound obtained by reacting (B) (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton (hereinafter sometimes referred to as component a), and (c) an aliphatic isocyanate compound having one isocyanate group (hereinafter sometimes referred to as component c). The latent curing agent of the present invention is the main agent used for curing the curable epoxy composition and is different from the curing catalyst used as an auxiliary.

[0008] 《Bicyclic compound (a) having an amidine skeleton》 The amidine skeleton in the bicyclic compound having an amidine skeleton is a structure represented by the following formula (1).

Chemical formula

Chemical formula

Chemical formula

[0009] 《Compound (a) having a guanidine skeleton》 The guanidine skeleton in the compound having a guanidine skeleton is represented by the following formula (4):

Chemical formula

Chemical formula

Chemical formula

[0010] 《Alcohol (b) having 1 to 20 carbon atoms》 Alcohols having 1 to 20 carbon atoms include primary alcohols, secondary alcohols, or tertiary alcohols. Examples of primary alcohols include methanol (C1), ethanol (C2), propane-1-ol (C3), butane-1-ol (C4), pentane-1-ol (C5), hexane-1-ol (C6), heptane-1-ol (C7), octane-1-ol (C8), nonane-1-ol (C9), decane-1-ol (C 10 ), undecane-1-ol (C 11 ), dodecane-1-ol (C 12 ), tridecane-1-ol (C 13 ), tetradecane-1-ol (C 14 ), pentadecane-1-ol (C 15 ), hexadecane-1-ol (C 16 ), heptadecane-1-ol (C 17 ), octadecane-1-ol (C 18 ), nonadecane-1-ol (C 19 ), or icosane-1-ol (C[[ID=二十一]] 20 [[ID=二十二]]). Examples of secondary alcohols include propane-2-ol (C3), butane-2-ol (C4), pentane-2-ol (C5), hexane-2-ol (C6), heptane-2-ol (C7), cyclohexanol (C6), or 2-methylbutan-1-ol (C5). Examples of tertiary alcohols include 2-methylpropan-2-ol (C4), 2-methylbutan-2-ol (C5), 2-methylpentan-2-ol (C6), 2-methylhexan-2-ol (C7), 2-methylheptan-2-ol (C8), 3-methylpentan-3-ol (C6), or 3-methyloctan-3-ol (C9). The alkyl groups contained in alcohols having 1 to 20 carbon atoms include linear alkyl groups, branched alkyl groups, or cyclic alkyl groups.

[0011] 《Aliphatic isocyanate compound (c)》 The aliphatic isocyanate compound is not particularly limited as long as it has one or more isocyanate groups, but examples include monoiocyanates and diosocyanates. Specific examples of aliphatic isocyanate compounds having one or more isocyanate groups include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, octadecyl isocyanate, hexyl isocyanate, and butyl isocyanate. Furthermore, aliphatic isocyanate compounds having one isocyanate group include monoiocyanates, and specific monoiocyanates include hexyl isocyanate, butyl isocyanate, cyclohexyl isocyanate, methyl isocyanate, ethyl isocyanate, or propyl isocyanate, but hexyl isocyanate, butyl isocyanate, cyclohexyl isocyanate, methyl isocyanate, ethyl isocyanate, or propyl isocyanate are preferred.

[0012] 《Amount of each ingredient added》 The amount of each component added in the reaction of the latent curing agent of the present invention is not particularly limited, as long as the effects of the present invention are obtained. For example, for 1 mol of aliphatic isocyanate compound (component c), a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton (component a) may be added in amounts of, for example, 0.01 to 5.0 mol. The lower limit is not limited, but in some embodiments it is 0.03 mol or more, in others 0.05 mol or more, in others 0.07 mol or more, in others 0.09 mol or more, in others 0.1 mol or more, and in others 0.2 mol or more. The upper limit is also not limited, but in some embodiments it is 4.5 mol or less, in others 4.0 mol or less, in others 3.5 mol or less, in others 3.0 mol or less, in others 2.5 mol or less, in others 2.0 mol or less, in others 1.5 mol or less, and in others 1.0 mol or less. The lower and upper limits can be arbitrarily combined to create a suitable range. In both embodiment (A) and embodiment (B) of the present invention, the ratio of the aliphatic isocyanate compound to the bicyclic compound having an amidine skeleton or the compound having a guanidine skeleton is the same. In embodiment (A) of the present invention, for example, 0.05 to 10.0 mol of an alcohol having 1 to 20 carbon atoms (component b) may be added to 1 mol of an aliphatic isocyanate compound (component c). The lower limit is not limited, but in some embodiments it is 0.07 mol or more, in some embodiments it is 0.09 mol or more, in some embodiments it is 0.1 mol or more, in some embodiments it is 0.2 mol or more, in some embodiments it is 0.3 mol or more, in some embodiments it is 0.4 mol or more, and in some embodiments it is 0.5 mol or more. The upper limit is also not limited, but in some embodiments it is 8.0 mol or less, in some embodiments it is 6.0 mol or less, in some embodiments it is 5.0 mol or less, in some embodiments it is 4.0 mol or less, in some embodiments it is 3.0 mol or less, in some embodiments it is 2.5 mol or less, and in some embodiments it is 2.0 mol or less. The lower limit and upper limit can be arbitrarily combined to obtain a suitable range.

[0013] 《Content of each ingredient》 The content (amount added) of each component in the latent curing agent of the present invention is not particularly limited, as long as the effects of the present invention are obtained. In embodiment (A) of the present invention, the content of component a relative to the total amount of latent curing agent is, for example, 1% to 50% by mass. The lower limit is, for example, 1% by mass or more, 2% by mass or more in some embodiments, 3% by mass or more in some embodiments, 4% by mass or more in some embodiments, 5% by mass or more in some embodiments, 7% by mass or more in some embodiments, 10% by mass or more in some embodiments, 12.5% ​​by mass or more in some embodiments, 15% by mass or more in some embodiments, 17.5% by mass or more in some embodiments, 20% by mass or more in some embodiments, 22.5% by mass or more in some embodiments, 25% by mass or more in some embodiments, 27.5% by mass or more in some embodiments, and 30% by mass or more in some embodiments. The upper limit is, for example, 50% by mass or less, 49% by mass or less in one embodiment, 48% by mass or less in another embodiment, 47% by mass or less in another embodiment, 46% by mass or less in another embodiment, 45% by mass or less in another embodiment, 42.5% by mass or less in another embodiment, 40% by mass or less in another embodiment, 37.5% by mass or less in another embodiment, 35% by mass or less in another embodiment, 32.5% by mass or less in another embodiment, 30% by mass or less in another embodiment, 27.5% by mass or less in another embodiment, and 25% by mass or less in another embodiment. The lower limit and upper limit can be combined as appropriate to set the range of component a.

[0014] The content of component b is, for example, 10% to 70% by mass relative to the total amount of latent curing agent. The lower limit is, for example, 10% by mass or more, 12.5% ​​by mass or more in some embodiments, 15% by mass or more in some embodiments, 17.5% by mass or more in some embodiments, 20% by mass or more in some embodiments, 22.5% by mass or more in some embodiments, 25% by mass or more in some embodiments, 27.5% by mass or more in some embodiments, 30% by mass or more in some embodiments, 32.5% by mass or more in some embodiments, 35% by mass or more in some embodiments, 37.5% by mass or more in some embodiments, 40% by mass or more in some embodiments, 42.5% by mass or more in some embodiments, and 45% by mass or more in some embodiments. The upper limit is, for example, 70% by mass or less, 67.5% by mass or less in one embodiment, 65% by mass or less in another embodiment, 62.5% by mass or less in another embodiment, 60% by mass or less in another embodiment, 57.5% by mass or less in another embodiment, 55% by mass or less in another embodiment, 52.5% by mass or less in another embodiment, 50% by mass or less in another embodiment, 47.5% by mass or less in another embodiment, 45% by mass or less in another embodiment, 42.5% by mass or less in another embodiment, 40% by mass or less in another embodiment, and 37.5% by mass or less in another embodiment. The lower limit and upper limit can be combined as appropriate to set the range of component b.

[0015] The content of component c is, for example, 10% to 70% by mass relative to the total amount of latent curing agent. The lower limit is, for example, 10% by mass or more, 12.5% ​​by mass or more in some embodiments, 15% by mass or more in some embodiments, 17.5% by mass or more in some embodiments, 20% by mass or more in some embodiments, 22.5% by mass or more in some embodiments, 25% by mass or more in some embodiments, 27.5% by mass or more in some embodiments, 30% by mass or more in some embodiments, 32.5% by mass or more in some embodiments, 35% by mass or more in some embodiments, 37.5% by mass or more in some embodiments, 40% by mass or more in some embodiments, 42.5% by mass or more in some embodiments, and 45% by mass or more in some embodiments. The upper limit is, for example, 70% by mass or less, in one embodiment 67.5% by mass or less, in another embodiment 65% by mass or less, in another embodiment 62.5% by mass or less, in another embodiment 60% by mass or less, in another embodiment 57.5% by mass or less, in another embodiment 55% by mass or less, in another embodiment 52.5% by mass or less, in another embodiment 50% by mass or less, in another embodiment 47.5% by mass or less, in another embodiment 45% by mass or less, in another embodiment 42.5% by mass or less, in another embodiment 40% by mass or less, and in another embodiment 37.5% by mass or less. The lower limit and upper limit can be combined as appropriate to determine the range of component c.

[0016] In the latent curing agent of embodiment (A) of the present invention, by having the contents of components a, b, and c within the aforementioned ranges, a liquid latent curing agent with excellent stability, which is the effect of the present invention, can be obtained.

[0017] In embodiment (B) of the present invention, the content of component a is, for example, 1% to 50% by mass relative to the total amount of latent curing agent. The lower limit is, for example, 1% by mass or more, 2% by mass or more in some embodiments, 3% by mass or more in some embodiments, 4% by mass or more in some embodiments, 5% by mass or more in some embodiments, 7% by mass or more in some embodiments, 10% by mass or more in some embodiments, 12.5% ​​by mass or more in some embodiments, 15% by mass or more in some embodiments, 17.5% by mass or more in some embodiments, 20% by mass or more in some embodiments, 22.5% by mass or more in some embodiments, 25% by mass or more in some embodiments, 27.5% by mass or more in some embodiments, and 30% by mass or more in some embodiments. The upper limit is, for example, 50% by mass or less, 49% by mass or less in one embodiment, 48% by mass or less in another embodiment, 47% by mass or less in another embodiment, 46% by mass or less in another embodiment, 45% by mass or less in another embodiment, 42.5% by mass or less in another embodiment, 40% by mass or less in another embodiment, 37.5% by mass or less in another embodiment, 35% by mass or less in another embodiment, 32.5% by mass or less in another embodiment, 30% by mass or less in another embodiment, 27.5% by mass or less in another embodiment, and 25% by mass or less in another embodiment. The lower limit and upper limit can be combined as appropriate to set the range of component a.

[0018] The content of component c is, for example, 40% to 99% by mass relative to the total amount of latent curing agent. The lower limit is, for example, 40% by mass or more, 42.5% by mass or more in some embodiments, 45% by mass or more in some embodiments, 47.5% by mass or more in some embodiments, 50% by mass or more in some embodiments, 52.5% by mass or more in some embodiments, 55% by mass or more in some embodiments, 57.5% by mass or more in some embodiments, 60% by mass or more in some embodiments, 62.5% by mass or more in some embodiments, 65% by mass or more in some embodiments, 67.5% by mass or more in some embodiments, 70% by mass or more in some embodiments, 72.5% by mass or more in some embodiments, and 75% by mass or more in some embodiments. The upper limit is, for example, 99% by mass or less, in one embodiment 97.5% by mass or less, in another embodiment 95% by mass or less, in another embodiment 92.5% by mass or less, in another embodiment 90% by mass or less, in another embodiment 87.5% by mass or less, in another embodiment 85% by mass or less, in another embodiment 82.5% by mass or less, in another embodiment 80% by mass or less, in another embodiment 77.5% by mass or less, in another embodiment 75% by mass or less, and in another embodiment 72% by mass. The lower and upper limits are 5% by mass or less in some embodiments, 70% by mass or less in some embodiments, 67.5% by mass or less in some embodiments, 65% by mass or less in some embodiments, 62.5% by mass or less in some embodiments, 60% by mass or less in some embodiments, 57.5% by mass or less in some embodiments, 55% by mass or less in some embodiments, 52.5% by mass or less in some embodiments, 50% by mass or less in some embodiments, 47.5% by mass or less in some embodiments, and 45% by mass or less in some embodiments. The lower and upper limits can be appropriately combined to set the range of component c.

[0019] In the latent curing agent of embodiment (B) of the present invention, by having the contents of components a and c within the above range, a liquid latent curing agent with excellent stability, which is the effect of the present invention, can be obtained.

[0020] The latent curing agent of the present invention may contain "other components" other than components a, b, and c, insofar as the effects of the present invention (excellent stability in liquid form) are obtained. The content of the other components is, for example, 79% by mass or less, 60% by mass or less in some embodiments, and 50% by mass or less in other embodiments. Other components included in latent curing agents include solvents, plasticizers, or excipients.

[0021] Compounds contained in latent curing agents The latent curing agent of the present invention comprises a compound obtained by reacting components a, b, and c. Alternatively, the latent curing agent of the present invention comprises a compound obtained by reacting components a and c.

[0022] The latent curing agent of the present invention is liquid. In this specification, liquid means not a solid, but having even a small amount of fluidity. Accordingly, the viscosity of the latent curing agent of the present invention is 10 million mPa·s or less, in some embodiments 5 million mPa·s or less, in some embodiments 100 mPa·s or less, in some embodiments 1 million mPa·s or less, in some embodiments 300,000 mPa·s or less, and in some embodiments 10 mPa·s or less. The lower limit is 1 mPa·s or more, in some embodiments 10 mPa·s or more, in some embodiments 100 mPa·s or more, and in some embodiments 500 mPa·s or more. While there are no limited methods for measuring viscosity, one method that can be used is the E-type viscometer. The E-type viscometer is a rotational viscometer that measures viscosity by placing the sample between a flat plate and a cone plate and rotating the cone plate. Specifically, the sample is placed between the flat plate and the cone plate, and the cone plate is rotated. By measuring the torque required for rotation, the viscosity is calculated from the measured torque. A suitable measurement temperature is, for example, 25°C.

[0023] Method for manufacturing latent curing agents The present invention provides a method for producing a latent curing agent by reacting (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton (component a), (b) an alcohol having 1 to 20 carbon atoms (component b), and (c) an aliphatic isocyanate compound having one or more isocyanate groups (component c). This reaction produces a compound exhibiting the effects of the latent curing agent of the present invention. Alternatively, the present invention provides a method for producing a latent curing agent by reacting (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton (component a) and (c) an aliphatic isocyanate compound having one isocyanate group (component c). This reaction produces a compound exhibiting the effects of the latent curing agent of the present invention.

[0024] In the method for producing the latent curing agent of the present invention, the amounts of component a, component b, and component c added are as described in "Amount of each component added" above, and there are no restrictions on the order of addition. The reaction temperature is not particularly limited, but is, for example, 23 to 200°C, preferably 50 to 150°C, and more preferably 80 to 120°C. The reaction time is also not particularly limited, but is 5 minutes to 100 hours, preferably 10 minutes to 50 hours, and more preferably 1 to 10 hours. For example, if the reaction temperature is high, the reaction time can be shortened, and if the reaction temperature is low, the reaction time can be lengthened.

[0025] [2] Thermosetting epoxide composition The thermosetting epoxide composition of the present invention comprises an epoxide compound having an average of more than one epoxy group in its molecule and the latent curing agent. As shown in the examples described below, the thermosetting epoxide composition of the present invention is stable when the epoxide compound and the latent curing agent are mixed. Therefore, it can be prepared as a one-component thermosetting epoxide composition and stored for a long period of time. However, the thermosetting epoxide composition of the present invention may also include a two-component thermosetting epoxide composition comprising a liquid containing the epoxide compound and a liquid latent curing agent, which can be prepared and stored.

[0026] Epoxide compounds The epoxide compounds that can be used in the thermosetting epoxide composition of the present invention are compounds that have an average of more than one epoxy group in their molecule.Specifically, these include glycidyl ethers obtained by reacting polyhydric phenols such as bisphenol A, bisphenol F, bisphenol S, hexahydrobisphenol A, tetramethylbisphenol A, tetramethylbisphenol F, catechol, resorcinol, cresol novolac, tetrabromobisphenol A, trihydroxybiphenyl, benzophenone, bisresorcinol, bisphenolhexafluoroacetone, hydroquinone, triphenylmethane, tetraphenylethane, and bixylenol with epichlorohydrin; polyglycidyl ethers obtained by reacting aliphatic polyhydric alcohols such as glycerin, neopentyl glycol, ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, polyethylene glycol, and polypropylene glycol with epichlorohydrin; glycidyl ether esters obtained by reacting hydroxycarboxylic acids such as p-oxybenzoic acid and β-oxynaphthoic acid with epichlorohydrin; phthalic acid, methylphthalic acid, isophthalic acid, terephthalic acid, tetrahydroxybenzo Examples of polyglycidyl esters obtained from polycarboxylic acids such as tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, endomethylenehexahydrophthalic acid, trimellitic acid, and polymerized fatty acids; glycidylaminoglycidyl ethers obtained from aminophenols and aminoalkylphenols; glycidylaminoglycidyl esters obtained from aminobenzoic acid; glycidylamines obtained from aniline, toluidine, tribromaniline, xylylenediamine, diaminocyclohexane, bisaminomethylcyclohexane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, etc.; epoxidized polyolefins; glycidyl hydantoin; glycidylalkyl hydantoin, triglycidyl cyanurate; or monoepoxides represented by butyl glycidyl ether, phenyl glycidyl ether, alkylphenyl glycidyl ether, glycidyl benzoate ester, styrene oxide, etc., and one or more of these can be used as a mixture.

[0027] The weight ratio or molar ratio of the epoxide compound to the latent curing agent in the thermosetting epoxide composition of the present invention is not particularly limited, as long as the one-component epoxide composition can be cured to any desired degree of gelation. In other words, thermosetting epoxide compositions are used for various applications such as adhesives, coatings, sealants, and impregnations, and the desired curing state, curing time, and usage conditions differ depending on the application. Therefore, the weight ratio or molar ratio of the epoxide compound to the latent curing agent in the epoxide composition can be appropriately selected. The weight ratio of the epoxide compound is not limited, but for example, the latent curing agent can be mixed with the epoxide compound in a molar ratio of 0.01 to 100, more preferably 0.05 to 50, and even more preferably 0.1 to 10. The content (amount added) of each component in the epoxide composition of the present invention is not particularly limited, as long as the effects of the present invention are obtained. In embodiment (A) of the present invention, the content of component a relative to the total amount of the epoxide composition is, for example, 0.2% to 10% by mass. The lower limit is, for example, 0.2% by mass or more, 0.4% by mass or more in some embodiments, 0.6% by mass or more in some embodiments, 0.8% by mass or more in some embodiments, 1% by mass or more in some embodiments, 1.4% by mass or more in some embodiments, 2% by mass or more in some embodiments, 2.5% by mass or more in some embodiments, 3% by mass or more in some embodiments, 3.5% by mass or more in some embodiments, 4% by mass or more in some embodiments, 4.5% by mass or more in some embodiments, 5% by mass or more in some embodiments, 5.5% by mass or more in some embodiments, and 6% by mass or more in some embodiments. The upper limit is, for example, 10% by mass or less, 9.8% by mass or less in one embodiment, 9.6% by mass or less in another embodiment, 9.4% by mass or less in another embodiment, 9.2% by mass or less in another embodiment, 9% by mass or less in another embodiment, 8.5% by mass or less in another embodiment, 8% by mass or less in another embodiment, 7.5% by mass or less in another embodiment, 7% by mass or less in another embodiment, 6.5% by mass or less in another embodiment, 6% by mass or less in another embodiment, 5.5% by mass or less in another embodiment, and 5% by mass or less in another embodiment. The lower limit and upper limit can be combined as appropriate to set the range of component a.

[0028] The content of component b is, for example, 2% to 14% by mass relative to the total amount of the epoxide composition. The lower limit is, for example, 2% by mass or more, 2.5% by mass or more in some embodiments, 3% by mass or more in some embodiments, 3.5% by mass or more in some embodiments, 4% by mass or more in some embodiments, 4.5% by mass or more in some embodiments, 5% by mass or more in some embodiments, 5.5% by mass or more in some embodiments, 6% by mass or more in some embodiments, 6.5% by mass or more in some embodiments, 7% by mass or more in some embodiments, 7.5% by mass or more in some embodiments, 8% by mass or more in some embodiments, 8.5% by mass or more in some embodiments, and 9% by mass or more in some embodiments. The upper limit is, for example, 14% by mass or less, 13.5% by mass or less in one embodiment, 13% by mass or less in another embodiment, 12.5% ​​by mass or less in another embodiment, 11.5% by mass or less in another embodiment, 11% by mass or less in another embodiment, 10.5% by mass or less in another embodiment, 9.5% by mass or less in another embodiment, 9% by mass or less in another embodiment, 8.5% by mass or less in another embodiment, 8% by mass or less in another embodiment, and 7.5% by mass or less in another embodiment. The lower and upper limits can be combined as appropriate to define the range of component b.

[0029] The content of component c is, for example, 2% to 14% by mass relative to the total amount of the epoxy composition. The lower limit is, for example, 2% by mass or more, 2.5% by mass or more in some embodiments, 3% by mass or more in some embodiments, 3.5% by mass or more in some embodiments, 4% by mass or more in some embodiments, 4.5% by mass or more in some embodiments, 5% by mass or more in some embodiments, 5.5% by mass or more in some embodiments, 6% by mass or more in some embodiments, 6.5% by mass or more in some embodiments, 7% by mass or more in some embodiments, 7.5% by mass or more in some embodiments, 8% by mass or more in some embodiments, 8.5% by mass or more in some embodiments, and 9% by mass or more in some embodiments. The upper limit is, for example, 14% by mass or less, 13.5% by mass or less in one embodiment, 13% by mass or less in another embodiment, 12.5% ​​by mass or less in another embodiment, 11.5% by mass or less in another embodiment, 11% by mass or less in another embodiment, 10.5% by mass or less in another embodiment, 9.5% by mass or less in another embodiment, 9% by mass or less in another embodiment, 8.5% by mass or less in another embodiment, 8% by mass or less in another embodiment, and 7.5% by mass or less in another embodiment. The lower and upper limits can be combined as appropriate to define the range of component b.

[0030] In the epoxide composition of embodiment (A) of the present invention, by having the contents of components a, b, and c within the aforementioned ranges, a liquid thermosetting epoxide composition with excellent stability, which is the effect of the present invention, can be obtained.

[0031] In embodiment (B) of the present invention, the content of component a relative to the total amount of the epoxide composition is, for example, 0.2% to 10% by mass. The lower limit is, for example, 0.2% by mass or more, 0.4% by mass or more in some embodiments, 0.6% by mass or more in some embodiments, 0.8% by mass or more in some embodiments, 1% by mass or more in some embodiments, 1.4% by mass or more in some embodiments, 2% by mass or more in some embodiments, 2.5% by mass or more in some embodiments, 3% by mass or more in some embodiments, 3.5% by mass or more in some embodiments, 4% by mass or more in some embodiments, 4.5% by mass or more in some embodiments, 5% by mass or more in some embodiments, 5.5% by mass or more in some embodiments, and 6% by mass or more in some embodiments. The upper limit is, for example, 10% by mass or less, 9.8% by mass or less in one embodiment, 9.6% by mass or less in another embodiment, 9.4% by mass or less in another embodiment, 9.2% by mass or less in another embodiment, 9% by mass or less in another embodiment, 8.5% by mass or less in another embodiment, 8% by mass or less in another embodiment, 7.5% by mass or less in another embodiment, 7% by mass or less in another embodiment, 6.5% by mass or less in another embodiment, 6% by mass or less in another embodiment, 5.5% by mass or less in another embodiment, and 5% by mass or less in another embodiment. The lower limit and upper limit can be combined as appropriate to set the range of component a.

[0032] The content of component c is, for example, 8% to 19.8% by mass relative to the total amount of the epoxyd composition. The lower limit is, for example, 8% by mass or more, in some embodiments 8.5% by mass or more, in some embodiments 9% by mass or more, in some embodiments 9.5% by mass or more, in some embodiments 10% by mass or more, in some embodiments 10.5% by mass or more, in some embodiments 11% by mass or more, in some embodiments 11.5% by mass or more, in some embodiments 12% by mass or more, in some embodiments 12.5% ​​by mass or more, in some embodiments 13% by mass or more, in some embodiments 13.5% by mass or more, in some embodiments 14% by mass or more, in some embodiments 14.5% by mass or more, and in some embodiments 15% by mass or more. The upper limit is, for example, 19.8% by mass or less, in one embodiment 19.5% by mass or less, in another embodiment 19% by mass or less, in another embodiment 18.5% by mass or less, in another embodiment 18% by mass or less, in another embodiment 17.5% by mass or less, in another embodiment 17% by mass or less, in another embodiment 16.5% by mass or less, in another embodiment 16% by mass or less, in another embodiment 15.5% by mass or less, in another embodiment 15% by mass or less, in another embodiment 1 The lower and upper limits are 4.5% by mass or less, in one embodiment 14% by mass or less, in another embodiment 13.5% by mass or less, in another embodiment 13% by mass or less, in another embodiment 12.5% ​​by mass or less, in another embodiment 12% by mass or less, in another embodiment 11.5% by mass or less, in another embodiment 11% by mass or less, in another embodiment 10.5% by mass or less, in another embodiment 10% by mass or less, in another embodiment 9.5% by mass or less, and in another embodiment 9% by mass or less. The lower and upper limits can be combined as appropriate to set the range of component c.

[0033] In the epoxide composition of embodiment (B) of the present invention, by having the contents of components a and c within the above range, a liquid thermosetting epoxide composition with excellent stability, which is the effect of the present invention, can be obtained.

[0034] The thermosetting epoxide composition of the present invention may optionally contain epoxy curing agents, inert organic or inorganic pigments, dyes, colorants, fade inhibitors, glare inhibitors, fluorescent whitening agents, surfactants, plasticizers, flame retardants, antioxidants, fillers, antistatic agents, defoaming agents, flow regulators, accelerators, retarders, thickeners, light stabilizers, antifungal agents, antibacterial agents, preservatives, magnetic materials, and the like.

[0035] Examples of epoxy curing agents that may be used as needed in the thermosetting epoxide composition of the present invention include acid anhydrides, amines, phenols, dihydrazines, Lewis acids, Brønsted salts, polymer captons, isocyanates, blocked isocyanates, dicyandiamides, and the like.

[0036] The thermosetting epoxide composition of the present invention does not harden at room temperature (e.g., 0°C to 40°C), but hardens rapidly upon heating (e.g., 100°C to 200°C), and can be used as an adhesive, paint, coating, sealing, and impregnation agent.

[0037] 《Action》 The mechanism by which the latent curing agent of the present invention is liquid has not been analyzed in detail, but it can be presumed as follows. However, the present invention is not limited by the following presumption. The latent curing agent of the present invention comprises a reaction product of (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, (b) an alcohol having 1 to 20 carbon atoms, and (c) an aliphatic isocyanate compound having one or more isocyanate groups, and the reaction product obtained from components (a), (b), and (c) is thought to have a specific structure. Furthermore, the latent curing agent of the present invention comprises a reaction product of (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, and (c) an aliphatic isocyanate compound having one isocyanate group, and the reaction product obtained from components (a) and (c) is thought to have a specific structure. Possible specific structures of the resulting reaction product include, for example, urea bonds or urethane bonds, but are not limited to these. However, it is presumed that by including compounds having these specific structures, the latent curing agent will exhibit a liquid state and good stability. [Examples]

[0038] 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.

[0039] In the following examples, a latent curing agent for a liquid curable epoxide composition at room temperature was prepared using an aliphatic isocyanate compound (component c), an alcohol compound (component b), and a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton (component a).

[0040] Example 1 In this example, 168.2 parts (1.0 mol) of hexamethylene diisocyanate (abbreviated as HMDI) as an aliphatic isocyanate compound and 90.1 parts (1.0 mol) of 1-methoxy-2-propanol (abbreviated as PM) as an alcohol compound were mixed, and 62.1 parts (0.5 mol) of 1,5-diazabicyclo[4.3.0]nonene-5 (abbreviated as DBN) as a heterobicyclic compound having an amidine skeleton was added dropwise to obtain a latent curing agent for a liquid curable epoxide composition at room temperature.

[0041] Example 2 The procedure of Example 1 was repeated, except that 54.1 parts (0.6 mol) of 1-methoxy-2-propanol (abbreviated as PM) were added and 86.9 parts (0.7 mol) of 1,5-diazabicyclo[4.3.0]nonene-5 (abbreviated as DBN) were used.

[0042] Example 3 The procedure of Example 1 was repeated, except that 126.1 parts (1.4 mol) of 1-methoxy-2-propanol (abbreviated as PM) was added and 37.3 parts (0.3 mol) of 1,5-diazabicyclo[4.3.0]nonene-5 (abbreviated as DBN) was used.

[0043] Example 4 The procedure of Example 3 was repeated, except that 159.8 parts (0.9 mol) of hexamethylene diisocyanate (abbreviated as HMDI) was used.

[0044] Example 5 The procedure of Example 3 was repeated, except that 210.3 parts (1.0 mol) of trimethylhexamethylene diisocyanate (abbreviated as TMDI) was used instead of HMDI.

[0045] Example 6 A latent curing agent for a liquid curable epoxide composition was obtained by adding 62.1 parts (0.5 mol) of 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) dropwise to 99.2 parts (1.0 mol) of butyl isocyanate (BI) as compound c, and reacting it dropwise.

[0046] Example 7 The procedure of Example 1 was repeated, except that 132.2 parts (1.0 mol) of 1-butoxy-2-propanol (abbreviated as PNB) was used as the alcohol compound.

[0047] Example 8 The procedure of Example 1 was repeated, except that 164.2 parts (1.0 mol) of triethylene glycol monomethyl ether (abbreviated as TGME) was used as the alcohol compound.

[0048] Example 9 The procedure of Example 3 was repeated, except that 45.7 parts (0.3 mol) of 1,8-diazabicyclo[5.4.0]undecene-7 (abbreviated as DBU) was used as a heterobicyclic compound having an amidine skeleton.

[0049] Example 10 The procedure of Example 1 was repeated, except that 153.2 parts (1.7 mol) of 1-methoxy-2-propanol was mixed in, and 23.0 parts (0.2 mol) of 1,1,3,3-tetramethylguanidine (abbreviated as TMG) ​​was used as the compound having a guanidine skeleton.

[0050] In Comparative Examples 1 to 3 below, curing agents were prepared using alicyclic or aromatic isocyanate compounds instead of aliphatic isocyanate compounds. In Comparative Examples 4 to 9, curing agents were prepared using heterozygous monochemical compounds, primary amine compounds, or secondary amine compounds with an amidine skeleton instead of bicyclic compounds with an amidine skeleton or compounds with a guanidine skeleton.

[0051] Comparative Example 1 As an alicyclic isocyanate compound, 222.2 parts (1.0 mol) of isophorone diisocyanate (abbreviated as IPDI) and 126.1 parts (1.4 mol) of 1-methoxy-2-propanol as an alcohol compound were mixed, and 37.3 parts (0.3 mol) of 1,5-diazabicyclo[4.3.0]nonene-5 (abbreviated as DBN), a heterobicyclic compound with an amidine skeleton, were added dropwise. The resulting product was solid at room temperature.

[0052] Comparative Example 2 The procedure of Comparative Example 1 was repeated, except that 174.2 parts (1.0 mol) of tolylene diisocyanate (abbreviated as TDI) was used as the aromatic isocyanate compound instead of IPDI. The resulting product was solid at room temperature.

[0053] Comparative Example 3 As an aromatic isocyanate compound, 119.1 parts (1.0 mol) of phenyl isocyanate (abbreviated as FI) was added dropwise to 62.1 parts (0.5 mol) of 1,5-diazabicyclo[4.3.0]nonene-5 (abbreviated as DBN). The resulting product was solid at room temperature.

[0054] Comparative Example 4 The procedure of Example 1 was repeated, except that 153.2 parts (1.7 mol) of 1-methoxy-2-propanol was used as the alcohol compound, and 33.1 parts (0.3 mol) of 2-ethyl-4-methylimidazole (abbreviated as 2E4MZ) was used as a heterozygous monochemical compound with an amidine skeleton instead of DBN. The obtained product was liquid at room temperature.

[0055] Comparative Example 5 The procedure of Comparative Example 4 was repeated, except that 24.6 parts (0.3 mol) of 2-methylimidazole (abbreviated as 2MI) was used as a heterozygous monochemical compound with an amidine skeleton instead of DBN. The resulting product was liquid at room temperature.

[0056] Comparative Example 6 The procedure of Comparative Example 4 was repeated, except that 20.4 parts (0.3 mol) of imidazole (abbreviated as IM), a heterozygous monochemical compound with an amidine skeleton, was used instead of DBN. The resulting product was liquid at room temperature.

[0057] Comparative Example 7 The procedure of Example 1 was repeated, except that 117.1 parts (1.3 mol) of 1-methoxy-2-propanol was used as the alcohol compound, and 41.4 parts (0.7 mol) of propylamine (abbreviated as PA) was used as the primary amine compound instead of DBN. The obtained product was solid at room temperature.

[0058] Comparative Example 8 The procedure of Comparative Example 7 was repeated, except that 74.9 parts (0.7 mol) of N-methylaniline (abbreviated as N-MA) was used as a secondary amine compound instead of PA. The resulting product was liquid at room temperature.

[0059] Comparative Example 9 The procedure of Comparative Example 7 was repeated, except that 84.8 parts (0.7 mol) of N-methylbenzylamine (abbreviated as N-MBA) was used as a secondary amine compound instead of PA. The resulting product was solid at room temperature.

[0060] The latent curing agents of the present invention obtained in Examples 1 to 10 and the curing agent compositions obtained in Comparative Examples 1 to 9 were measured in the following manner. Evaluation of the hardening agent's shape The shape of the obtained curing agent was visually determined at room temperature to determine whether it was liquid or solid. Table 1 shows the types and amounts of isocyanate compounds, alcohol compounds, and amine compounds used in the latent curing agents of the present invention obtained in Examples 1 to 10 and the curing agent compositions obtained in Comparative Examples 1 to 9, as well as the shape of the obtained curing agent compositions at 23°C.

[0061] [Table 1] HMDI: Hexamethylene diisocyanate TMDI: Trimethylhexamethylene diisocyanate BI: Butyl isocyanate IPDI: Isophorone diisocyanate TDI: Tolylene diisocyanate FI: Phenyl isocyanate PM: 1-Methoxy-2-propanol PNB: 1-Butoxy-2-propanol TGME: Triethylene glycol monomethyl ether DBN:1,5-Diazabicyclo[4.3.0]nonene-5 DBU:1,8-Diazabicyclo[5.4.0]undecene-7 2E4MZ: 2-ethyl-4-methylimidazole 2MI: 2-methylimidazole IM: Imidazole PA: Propylamine N-MA:N-methylaniline N-MBA: N-methylbenzylamine

[0062] In Examples 1-4, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) as the heterobicyclic compound having an amidine skeleton or a compound having a guanidine skeleton. However, the resulting latent curing agents were liquid. In Example 5, trimethylhexamethylene diisocyanate (TMDI) was used as the aliphatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) as the heterobicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, but the resulting latent curing agent was liquid. In Example 6, butyl isocyanate (BI) was used as the aliphatic isocyanate compound, and 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) was used as the heterobicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, but the resulting latent curing agent was liquid. In Example 7, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, 1-butoxy-2-propanol (PNB) as the alcohol compound, and 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) as the heterobicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, but the resulting latent curing agent was liquid. In Example 8, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, triethylene glycol monomethyl ether (TGME) as the alcohol compound, and 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) was used as the heterobicyclic compound having an amidine skeleton or the compound having a guanidine skeleton, but the resulting latent curing agent was in liquid form. In Example 9, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) as the heterobicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, but the resulting latent curing agent was liquid. In Example 10, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and 1,1,3,3-tetramethylguanidine (TMG) as the heterobicyclic compound having an amidine skeleton or the compound having a guanidine skeleton. However, the resulting latent curing agent was in liquid form.

[0063] In Comparative Example 1, isophorone diisocyanate (IPDI) was used as the alicyclic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) as the heterobicyclic compound having an amidine skeleton or the compound having a guanidine skeleton. However, the resulting latent curing agent was solid. In Comparative Example 2, tolylene diisocyanate (TDI) was used as the aromatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) as the heterobicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, but the resulting latent curing agent was solid. In Comparative Example 3, phenyl isocyanate (FI) was used as the aromatic isocyanate compound, and 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) was used as the heterobicyclic compound having an amidine skeleton or a compound having a guanidine skeleton, but the resulting latent curing agent was solid. In Comparative Example 4, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and 2-ethyl-4-methylimidazole (2E4MZ) as the heterozygous monocrystalline compound with an amidine skeleton, but the resulting latent curing agent was liquid. In Comparative Example 5, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and 2-methylimidazole (2MI) as the heterozygous monochemical compound having an amidine skeleton. However, the resulting latent curing agent was liquid. In Comparative Example 6, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and imidazole (IM) as the heterozygous monochemical compound having an amidine skeleton. However, the resulting latent curing agent was liquid. In Comparative Example 7, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and propylamine (PA) as the primary amine compound, but the resulting latent curing agent was solid. In Comparative Example 8, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and N-methylaniline (N-MA) as the secondary amine compound, but the resulting latent curing agent was liquid. In Comparative Example 9, hexamethylene diisocyanate (HMDI) was used as the aliphatic isocyanate compound, 1-methoxy-2-propanol (PM) as the alcohol compound, and N-methylbenzylamine (N-MBA) as the secondary amine compound, but the resulting latent curing agent was solid.

[0064] In the following Examples 11 to 19, the curable epoxide compositions of the present invention were prepared. Example 11 A one-component curable epoxide composition was obtained by mixing 100 parts of diglycidyl ether of bisphenol A (abbreviated as BADGE) with an epoxy equivalent of 190 as the epoxide, and 20 parts of the latent curing agent obtained in Example 1, which is liquid at room temperature, as the latent curing agent.

[0065] Example 12 The procedure of Example 11 was repeated, except that 10 parts of the latent curing agent obtained in Example 2, which is liquid at room temperature, was used as the latent curing agent.

[0066] Example 13 The procedure of Example 11 was repeated, except that 30 parts of the latent curing agent obtained in Example 3, which is liquid at room temperature, was used as the latent curing agent.

[0067] Example 14 The procedure of Example 11 was repeated, except that 30 parts of the latent curing agent obtained in Example 4, which is liquid at room temperature, were used as the latent curing agent.

[0068] Example 15 The procedure of Example 10 was repeated, except that 30 parts of the latent curing agent obtained in Example 5, which is liquid at room temperature, were used as the latent curing agent.

[0069] Example 16 The procedure of Example 11 was repeated, except that 10 parts of the latent curing agent obtained in Example 6, which is liquid at room temperature, was used as the latent curing agent.

[0070] Example 17 The procedure of Example 11 was repeated, except that 30 parts of the latent curing agent obtained in Example 7, which is liquid at room temperature, were used as the latent curing agent.

[0071] Example 18 The procedure of Example 11 was repeated, except that 30 parts of the latent curing agent obtained in Example 8, which is liquid at room temperature, were used as the latent curing agent.

[0072] Example 19 The procedure of Example 11 was repeated, except that 30 parts of the latent curing agent obtained in Example 9, which is liquid at room temperature, were used as the latent curing agent.

[0073] Example 20 The procedure of Example 11 was repeated, except that 30 parts of the latent curing agent obtained in Example 10, which is liquid at room temperature, was used as the latent curing agent.

[0074] Comparative Example 10 The procedure of Example 11 was repeated, except that 30 parts of the latent curing agent obtained in Comparative Example 4, which is liquid at room temperature, was used as the latent curing agent.

[0075] Comparative Example 11 The procedure of Example 11 was repeated, except that 30 parts of the latent curing agent obtained in Comparative Example 5, which is liquid at room temperature, were used as the latent curing agent.

[0076] Comparative Example 12 The procedure of Example 11 was repeated, except that 30 parts of the latent curing agent obtained in Comparative Example 6, which is liquid at room temperature, was used as the latent curing agent.

[0077] Comparative Example 13 The procedure of Example 11 was repeated, except that 30 parts of the latent curing agent obtained in Comparative Example 8, which is liquid at room temperature, were used as the latent curing agent.

[0078] The viscosity increase at room temperature and curability when heated to 150°C were investigated for the one-component curable epoxide compositions of the present invention obtained in Examples 11 to 20 and the curable epoxide compositions obtained in Comparative Examples 10 to 13, using the following methods. Evaluation of viscosity increase The fluidity of the obtained curable epoxide compositions was visually evaluated after being stored at 40°C for 7 days and 30 days. ○: Liquidity available ×: No liquidity

[0079] Evaluation of hardening properties The obtained curable epoxide composition was heated at a predetermined temperature for a predetermined time, and its state was observed. Specifically, 2.0 g of the curable epoxide composition was placed in a metal container as a sample and left to stand on a hot plate set to 150°C for 1 hour. The evaluation was performed according to the following criteria. ○: Cures after 1 hour at 150℃ ×: Did not harden after 1 hour at 150℃

[0080] Table 2 shows the type of curing agent used in the one-component curable epoxide compositions of the present invention obtained in Examples 11 to 20, and in the curable epoxide compositions obtained in Comparative Examples 10 to 13, the weight ratio of the curing agent composition to the epoxide compound, the results of the viscosity increase evaluation, and the results of the curability evaluation.

[0081] [Table 2]

[0082] In Examples 11-20, one-component curable epoxide compositions were prepared using the latent curing agents obtained in Examples 1-10. The fluidity of the obtained curable epoxide compositions was confirmed after 7 and 30 days at 40°C, and curing was confirmed at 150°C for 1 hour.

[0083] In Comparative Examples 10-12, one-component curable epoxide compositions were prepared using the latent curing agents obtained in Comparative Examples 4-6. The resulting curable epoxide compositions did not exhibit fluidity after 7 and 30 days at 40°C. Curability was confirmed at 150°C for 1 hour. In Comparative Example 13, a one-component curable epoxide composition was prepared using the latent curing agent obtained in Comparative Example 8. The fluidity of the obtained curable epoxide composition was confirmed after 7 and 30 days at 40°C. Curability was not observed at 150°C for 1 hour. As described above, the present invention makes it possible to obtain a latent curing agent that is liquid at room temperature by reacting a compound obtained by reacting a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton with an alcohol compound and an aliphatic isocyanate compound having one or more isocyanate groups. Furthermore, the present invention can provide a one-component curable epoxide composition containing an epoxide having an average of more than one epoxy group in the molecule and a latent curing agent that is liquid at room temperature as essential components. [Industrial applicability]

[0084] The latent curing agent of the present invention can be used as a liquid latent curing agent for thermosetting epoxide compositions. The thermosetting epoxide composition of the present invention can be used as a one-component curable epoxide composition and can be used in adhesives, coatings, and the like.

Claims

1. (A) (a) Bicyclic compounds having an amidine skeleton, or compounds having a guanidine skeleton, (b) Alcohols having 1 to 20 carbon atoms, (c) an aliphatic isocyanate compound having one or more isocyanate groups, A compound obtained by reacting with; or (B) (a) Bicyclic compounds having an amidine skeleton, or compounds having a guanidine skeleton, and (c) Compounds obtained by reacting an aliphatic isocyanate compound having one isocyanate group; A latent curing agent containing [the specified ingredient].

2. In (A) above, the molar ratio of the aliphatic isocyanate compound to the bicyclic compound having an amidine skeleton or the compound having a guanidine skeleton is 0.01 to 5.0, and the molar ratio of the alcohol having 1 to 20 carbon atoms is 0.05 to 10.

0. The latent curing agent according to claim 1, wherein in (B) above, the molar ratio of the bicyclic compound having an amidine skeleton or the compound having a guanidine skeleton to the aliphatic isocyanate compound is 0.01 to 5.

0.

3. In (A) above, with respect to the total amount of latent curing agent, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 1% to 50% by mass, (b) an alcohol having 1 to 20 carbon atoms is 10% to 70% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 10% to 70% by mass. In (B) above, with respect to the total amount of latent curing agent, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 1% to 50% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 40% to 99% by mass. The latent curing agent according to claim 1.

4. (A) (a) Bicyclic compounds having an amidine skeleton, or compounds having a guanidine skeleton, (b) Alcohols having 1 to 20 carbon atoms, (c) an aliphatic isocyanate compound having one or more isocyanate groups, To cause a reaction; or (B) (a) Bicyclic compounds having an amidine skeleton, or compounds having a guanidine skeleton, and (c) an aliphatic isocyanate compound having one isocyanate group, To cause a reaction; A method for producing a latent curing agent, characterized by the following.

5. In (A) above, the molar ratio of the aliphatic isocyanate compound to the bicyclic compound having an amidine skeleton or the compound having a guanidine skeleton is 0.01 to 5.0, and the molar ratio of the alcohol having 1 to 20 carbon atoms is 0.05 to 10.

0. The method for producing a latent curing agent according to claim 3, wherein in (B) above, the molar ratio of the aliphatic isocyanate compound to the bicyclic compound having an amidine skeleton or the compound having a guanidine skeleton is 0.01 to 5.

0.

6. In (A) above, with respect to the total amount of latent curing agent, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 1% to 50% by mass, (b) an alcohol having 1 to 20 carbon atoms is 10% to 70% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 10% to 70% by mass. In (B) above, with respect to the total amount of latent curing agent, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 1% to 50% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 40% to 99% by mass. A method for producing a latent curing agent according to claim 4.

7. A thermosetting epoxide composition comprising an epoxide compound having an average of more than one epoxy group in its molecule, and a latent curing agent according to any one of claims 1 to 3.

8. In (A) above, with respect to the total amount of the thermosetting epoxide composition, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 0.2% to 10% by mass, (b) an alcohol having 1 to 20 carbon atoms is 2% to 14% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 2% to 14% by mass. In (B) above, with respect to the total amount of the thermosetting epoxide composition, (a) a bicyclic compound having an amidine skeleton or a compound having a guanidine skeleton is 0.2% to 10% by mass, and (c) an aliphatic isocyanate compound having one or more isocyanate groups is 8% to 19.8% by mass. The thermosetting epoxide composition according to claim 7.

9. A cured product obtained by curing the thermosetting epoxide composition according to claim 7 or 8.

10. A paint comprising the thermosetting epoxide composition according to claim 7 or 8.

11. An adhesive comprising the thermosetting epoxide composition according to claim 7 or 8.

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