Alicyclic diamine and alicyclic diamine composition

Abstract

Provided is a novel alicyclic diamine which, particularly when used especially as an epoxy resin curing agent, can form a coating film having excellent adhesion. Also provided is an alicyclic diamine that can be produced from a biomass-derived raw material. Also provided is an epoxy resin curing agent containing the alicyclic diamine and an alicyclic diamine composition containing the alicyclic diamine. The alicyclic diamine is represented by general formula (1). (In formula (1), n1 is 1-5, n2 is 1-5, and –(CH2)n1-NH2 bonds to a or b.)

Description

Alicyclic diamine and alicyclic diamine composition

[0001] The present invention relates to alicyclic diamines and alicyclic diamine compositions.

[0002] Diamines having a cyclic structure made of saturated hydrocarbons (alicyclic diamines) are used as synthetic resin raw materials, intermediates in organic synthetic chemistry, curing agents for epoxy resins, etc. For example, Patent Document 1 lists diaminomethylnorbornane as an example of a raw material for obtaining a novel bisamide compound that is a raw material for resins with good transparency.

[0003] Diamine compounds are also known as a type of epoxy resin curing agent. Epoxy resin compositions using diamine compounds as epoxy resin curing agents are used in the paint field, such as anticorrosion paints for ships, bridges, and land and sea steel structures, and in the civil engineering and construction field, such as linings, reinforcing, and repair materials for concrete structures, flooring materials for buildings, linings for water and sewer systems, paving materials, and adhesives. Of these, it is important for epoxy resin compositions for paints to have good coating film appearance, adhesion, chemical resistance, coating film properties, etc.

[0004] JP 2011-219539 A

[0005] Coating films obtained using epoxy resin compositions are prone to deterioration in their physical properties due to the influence of carbon dioxide gas and moisture. Addition of additives has been used to improve this. However, while the addition of additives generally improves certain physical properties, it also tends to reduce adhesion. High adhesion is desired in applications other than coatings, such as linings and adhesives. Furthermore, in response to recent environmental concerns, resins made from biomass have been developed, and biomass-derived raw materials are also required. Therefore, an object of the present invention is to provide a novel alicyclic diamine that can form coating films with excellent adhesion, particularly when used as an epoxy resin curing agent. Furthermore, an object of the present invention is to provide an alicyclic diamine that can be produced using biomass-derived raw materials.

[0006] The present inventors have found that an alicyclic diamine and an alicyclic diamine composition having a specific structure can solve the above problems, and have thus completed the present invention.

[0007] That is, the present invention is as follows: [1] An alicyclic diamine represented by the following general formula (1): (In formula (1), n1 is 1 to 5, n2 is 1 to 5, and —(CH ２ ) ｎ１ -NH ２ is bonded to a or b.) [2] The alicyclic diamine according to [1] above, wherein n1 in the formula (1) is 1 and n2 is 1. [3] The alicyclic diamine according to [1] above, wherein n1 in the formula (1) is 1 and n2 is 1, and -(CH ２ ) ｎ１ -NH ２ [4] In the formula (1), n1 is 1, n2 is 1, and —(CH ２ ) ｎ１ -NH ２ [5] The alicyclic diamine according to any one of [1] to [4] above, having a biomass degree of 30 mass% or more. [6] An alicyclic diamine composition containing an alicyclic diamine represented by the following formula (2) and an alicyclic diamine represented by the following formula (3): [7] The alicyclic diamine composition according to [6] above, having a biomass degree of 30% by mass or more. [8] An epoxy resin curing agent containing at least one selected from the group consisting of the alicyclic diamine according to any one of [1] to [5] above, the alicyclic diamine composition according to [6] or [7] above, a reaction product of an epoxy compound having at least one epoxy group with the alicyclic diamine according to any one of [1] to [5] above, and a reaction product of an epoxy compound having at least one epoxy group with the alicyclic diamine composition according to [6] or [7] above. [9] The epoxy resin curing agent according to [8] above, having a biomass degree of 30% by mass or more.

[10] A method for producing an alicyclic diamine, comprising hydrogenating and amminating a nitrile represented by the following general formula (4) or a nitrile represented by the following general formula (5) to obtain an alicyclic diamine represented by the following general formula (1): (In formula (4), n3 is 0 to 4, n4 is 0 to 4, and —(CH ２ ) ｎ３ -CN is bonded to a or b. In formula (5), n2 is 1 to 5, n3 is 0 to 4, and -(CH ２ ) ｎ３ -CN is bonded to a or b. In formula (1), n1 is 1 to 5, n2 is 1 to 5, and -(CH ２ ) ｎ１ -NH ２ is bonded to a or b.)

[11] The method for producing an alicyclic diamine according to

[10] above, wherein the nitrile represented by the general formula (4) or the nitrile represented by the general formula (5) is a nitrile obtained using furfural or furfuryl alcohol as a raw material.

[0008] According to the present invention, it is possible to provide a novel alicyclic diamine that can form a coating film with excellent adhesion, particularly when used as an epoxy resin curing agent.Furthermore, it is possible to provide an alicyclic diamine that can be produced using raw materials derived from biomass.

[0009] Hereinafter, in this specification, the expression "XX to YY" means "XX or more and YY or less."

[0010] [Alicyclic Diamine and Alicyclic Diamine Composition] The alicyclic diamine of the present invention is an alicyclic diamine represented by the following general formula (1). (In formula (1), n1 is 1 to 5, n2 is 1 to 5, and —(CH ２ ) ｎ１ -NH ２ binds to a or b.)

[0011] In formula (1), n1 is 1 to 5, preferably 1 to 3, and more preferably 1. n2 is 1 to 5, preferably 1 to 3, and more preferably 1. Therefore, n1 is 1 to 5 and n2 is 1 to 5, preferably n1 is 1 to 3 and n2 is 1 to 3, and more preferably n1 is 1 and n2 is 1. In formula (1), n1 and n2 are integers.

[0012] In formula (1), a and b represent the carbon atoms and the positions of the carbon atoms in the hydrocarbon ring. ２ ) ｎ１ -NH ２ binds to a or b, but -(CH ２ ) ｎ１ -NH ２ is bonded to a, the alicyclic diamine represented by formula (1) is an alicyclic diamine represented by the following formula (1a), ２ ) ｎ１ -NH ２ is bonded to b, the alicyclic diamine represented by formula (1) is an alicyclic diamine represented by the following formula (1b). Therefore, the alicyclic diamine represented by formula (1) is an alicyclic diamine represented by formula (1a) or an alicyclic diamine represented by formula (1b). Furthermore, the alicyclic diamine represented by formula (1a) and the alicyclic diamine represented by formula (1b) each include two types of stereoisomers (exo, endo), and the alicyclic diamine may be any one type of stereoisomer or a mixture of two types of stereoisomers.

[0013] In formulas (1a) and (1b), n1 is 1 to 5, preferably 1 to 3, and more preferably 1. n2 is 1 to 5, preferably 1 to 3, and more preferably 1. Therefore, n1 is 1 to 5 and n2 is 1 to 5, preferably n1 is 1 to 3 and n2 is 1 to 3, and more preferably n1 is 1 and n2 is 1. In formulas (1a) and (1b), n1 and n2 are integers.

[0014] In formula (1), when n1 is 1 and n2 is 1, -(CH ２ ) ｎ１ -NH ２ binds to a or b, but -(CH ２ ) ｎ１ -NH ２ is bonded to a, the alicyclic diamine represented by formula (1) is an alicyclic diamine represented by the following formula (2), ２ ) ｎ１ -NH ２is bonded to b, the alicyclic diamine represented by formula (1) is an alicyclic diamine represented by formula (3) below. Therefore, the alicyclic diamine represented by formula (1) is an alicyclic diamine represented by formula (2) or an alicyclic diamine represented by formula (3). Furthermore, the alicyclic diamine represented by formula (2) and the alicyclic diamine represented by formula (3) each contain two types of stereoisomers (exo, endo), and the alicyclic diamine may be either one type of stereoisomer or a mixture of two types of stereoisomers. The alicyclic diamine represented by formula (2) is (7-oxabicyclo[2.2.1]heptane-1,3-diyl)dimethanamine, and the alicyclic diamine represented by formula (3) is (7-oxabicyclo[2.2.1]heptane-1,2-diyl)dimethanamine.

[0015] The alicyclic diamine of the present invention preferably has a biomass degree of 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, and even more preferably 90% by mass or more. There is no upper limit, but it is 100% by mass or less, and even more preferably 100% by mass. As described below, the alicyclic diamine can be obtained using biomass-derived furfural or furfuryl alcohol as a raw material, and the biomass degree can be adjusted to the above range by using biomass-derived raw materials including these. The biomass degree is the mass proportion of the biomass raw material among the raw materials that contribute to the structure of the resulting alicyclic diamine.

[0016] The present invention also includes an alicyclic diamine composition containing an alicyclic diamine represented by the following formula (1a) and an alicyclic diamine represented by the following formula (1b). That is, the alicyclic diamine composition of the present invention can also be said to be a mixture of the alicyclic diamine represented by formula (1a) and the alicyclic diamine represented by formula (1b), which are the alicyclic diamines. Furthermore, the alicyclic diamine represented by formula (1a) and the alicyclic diamine represented by formula (1b) each contain two types of stereoisomers (exo, endo). The alicyclic diamine represented by formula (1a) and the alicyclic diamine represented by formula (1b) contained in the alicyclic diamine composition of the present invention may be any one type of stereoisomer or a mixture of two types of stereoisomers.

[0017] In the alicyclic diamine composition of the present invention, the mass ratio of the alicyclic diamine represented by formula (1a) to the alicyclic diamine represented by formula (1b) [(1a) / (1b)] is preferably 10 / 90 to 90 / 10, more preferably 20 / 80 to 80 / 20, even more preferably 30 / 70 to 70 / 30, and still more preferably 40 / 60 to 60 / 40.

[0018] The alicyclic diamine composition of the present invention is preferably an alicyclic diamine composition containing an alicyclic diamine represented by the following formula (2) and an alicyclic diamine represented by the following formula (3). That is, the alicyclic diamine composition of the present invention is preferably a mixture of the alicyclic diamine represented by formula (2) and the alicyclic diamine represented by formula (3), which are the alicyclic diamines. Furthermore, the alicyclic diamine represented by formula (2) and the alicyclic diamine represented by formula (3) each contain two types of stereoisomers (exo, endo). The alicyclic diamine represented by formula (2) and the alicyclic diamine represented by formula (3) contained in the alicyclic diamine composition of the present invention may be any one type of stereoisomer or a mixture of two types of stereoisomers. The alicyclic diamine represented by formula (2) is (7-oxabicyclo[2.2.1]heptane-1,3-diyl)dimethanamine, and the alicyclic diamine represented by formula (3) is (7-oxabicyclo[2.2.1]heptane-1,2-diyl)dimethanamine.

[0019] The alicyclic diamine composition of the present invention preferably has a biomass degree of 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, and even more preferably 90% by mass or more. There is no upper limit, but it is 100% by mass or less, and even more preferably 100% by mass. As described below, the alicyclic diamine composition can be obtained using biomass-derived furfural or furfuryl alcohol as a raw material, and the biomass degree can be adjusted to the above range by using biomass-derived raw materials including these. The biomass degree is the mass proportion of the biomass raw materials among the raw materials that contribute to the structure of the resulting alicyclic diamine.

[0020] [Method for Producing Alicyclic Diamine] Although there are no limitations on the method for producing the alicyclic diamine of the present invention, it is preferable to obtain it by the following production method: That is, a preferred method for producing an alicyclic diamine is a method for producing an alicyclic diamine by hydrogenating and amminating a nitrile represented by the following general formula (4) or a nitrile represented by the following general formula (5) to obtain an alicyclic diamine represented by the following general formula (1): (In formula (4), n3 is 0 to 4, n4 is 0 to 4, and —(CH ２ ) ｎ３ -CN is bonded to a or b. In formula (5), n2 is 1 to 5, n3 is 0 to 4, and -(CH ２ ) ｎ３ -CN is bonded to a or b. In formula (1), n1 is 1 to 5, n2 is 1 to 5, and -(CH ２ ) ｎ１ -NH ２ binds to a or b.)

[0021] In formula (4), n3 is 0 to 4, preferably 0 to 2, and more preferably 0. n4 is 0 to 4, preferably 0 to 2, and more preferably 0. Therefore, n3 is 0 to 4 and n4 is 0 to 4, preferably n3 is 0 to 2 and n4 is 0 to 2, and more preferably n3 is 0 and n4 is 0. Note that n3 and n4 in formula (4) are integers.

[0022] In formula (5), n3 is 0 to 4, preferably 0 to 2, and more preferably 0. n2 is 1 to 5, preferably 1 to 3, and more preferably 1. Therefore, n3 is 0 to 4 and n2 is 1 to 5, preferably n3 is 0 to 2 and n2 is 1 to 3, and more preferably n3 is 0 and n2 is 1. Note that n3 and n2 in formula (5) are integers.

[0023] <Hydrogenation / Amination Step> This step is a step in which a nitrile represented by formula (4) or a nitrile represented by formula (5) is hydrogenated and aminated to obtain an alicyclic diamine represented by the following general formula (1). This step may be carried out in two stages, namely, a hydrogenation step and an amination step. For example, the cyano group of the nitrile represented by formula (4) or the nitrile represented by formula (5) may be hydrogenated, followed by aminating the carbonyl group or hydroxyl group. From the viewpoint of efficiently obtaining an alicyclic diamine represented by formula (1), it is preferable to carry out hydrogenation and amination simultaneously by simultaneously introducing hydrogen and ammonia. The step of simultaneously carrying out hydrogenation and amination is described below, but the hydrogenation step and amination step can also be carried out separately by separately introducing hydrogen and ammonia under similar conditions. The reaction of this step is represented by the following formula: (In formula (4), n3 is 0 to 4, n4 is 0 to 4, and —(CH ２ ) ｎ３ -CN is bonded to a or b. In formula (5), n2 is 1 to 5, n3 is 0 to 4, and -(CH ２ ) ｎ３ -CN is bonded to a or b. In formula (1), n1 is 1 to 5, n2 is 1 to 5, and -(CH ２ ) ｎ１ -NH ２ binds to a or b.)

[0024] In formula (4), a and b represent the carbon atoms and the positions of the carbon atoms in the hydrocarbon ring. ２ ) ｎ３ -CN is bonded to a or b, but -(CH ２ ) ｎ３When —CN is bonded to a, the nitrile represented by formula (4) is a nitrile represented by the following formula (4a), and —(CH ２ ) ｎ３ When —CN is bonded to b, the nitrile represented by formula (4) is a nitrile represented by the following formula (4b): The nitrile represented by formula (4a) and the nitrile represented by formula (4b) each include two types of stereoisomers (exo, endo), and the nitrile may be either one type of stereoisomer or a mixture of the two types of stereoisomers.

[0025] In formula (5), a and b represent the carbon atoms and the positions of the carbon atoms in the hydrocarbon ring. ２ ) ｎ３ -CN is bonded to a or b, but -(CH ２ ) ｎ３ When —CN is bonded to a, the nitrile represented by formula (5) is a nitrile represented by the following formula (5a), and —(CH ２ ) ｎ３ When —CN is bonded to b, the nitrile represented by formula (5) is a nitrile represented by the following formula (5b): The nitrile represented by formula (5a), the nitrile represented by formula (5b), and the nitrile represented by formula (5c) each include two types of stereoisomers (exo, endo), and the nitrile may be any one type of stereoisomer or a mixture of two types of stereoisomers. (In formulas (4a) and (4b), n3 is 0 to 4, and n4 is 0 to 4. In formulas (5a) and (5b), n2 is 1 to 5, and n3 is 0 to 4. In formulas (1a) and (1b), n1 is 1 to 5, and n2 is 1 to 5.)

[0026] As described above, in this step, the nitrile represented by formula (4a) or the nitrile represented by formula (5a) can be hydrogenated and aminated to obtain the alicyclic diamine represented by formula (1a), and the nitrile represented by formula (4b) or the nitrile represented by formula (5b) can be hydrogenated and aminated to obtain the alicyclic diamine represented by formula (1b). When obtaining the alicyclic diamine composition containing the alicyclic diamine represented by formula (1a) and the alicyclic diamine represented by formula (1b), the alicyclic diamine represented by formula (1a) and the alicyclic diamine represented by formula (1b) may be synthesized separately by the above reaction and then mixed in a desired ratio to obtain the alicyclic diamine composition. Alternatively, the alicyclic diamine represented by formula (1a) and the alicyclic diamine represented by formula (1b) may be obtained by the above reaction using either a nitrile mixture containing the nitrile represented by formula (4a) and the nitrile represented by formula (4b) or a nitrile mixture containing the nitrile represented by formula (5a) and the nitrile represented by formula (5b) as raw materials. Since an alicyclic diamine composition can be efficiently obtained in one reaction, it is preferable to use the nitrile mixture as a raw material to obtain an alicyclic diamine represented by formula (1a) and an alicyclic diamine represented by formula (1b) by the above reaction. A method using a nitrile represented by formula (4) as a raw material will be described first, and then a method using a nitrile represented by formula (5) as a raw material will be described.

[0027] (Production method using a nitrile represented by formula (4) as a starting material) The type of hydrogenation and amination reaction in this step is not particularly limited, and may be any of a batch system, a semi-continuous system, a continuous system, or the like. The reaction temperature for the hydrogenation and amination is preferably 40 to 300°C, more preferably 60 to 200°C. From the viewpoints of selectivity and reaction rate, it is even more preferably 70 to 180°C. The pressure during the hydrogenation and amination reaction is preferably 1 to 20 MPa, more preferably 2 to 10 MPa. The hydrogenation and amination reaction can be carried out without a solvent, but a solvent may be used. Examples of solvents used during the hydrogenation and amination reaction include water; aromatic compounds such as benzene, o-dichlorobenzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; alcohols such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, ethylene glycol, and diethylene glycol; ethers such as dioxane, tetrahydrofuran, dimethoxyethane, and diglyme; and mixtures thereof. The amount of solvent used in the hydrogenation and amination reactions is preferably 0 to 30 times by mass, more preferably 0 to 20 times by mass, relative to the amount of the nitrile represented by formula (4). The catalyst used in the hydrogenation and amination reactions is not particularly limited as long as it is a catalyst typically used in the hydrogenation of nitriles or the amination of aldehydes. However, a catalyst containing at least one metal selected from Groups 8 to 11 of the Periodic Table is preferred. Specific examples include catalysts containing at least one metal selected from the group consisting of iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. The catalyst may be a solid catalyst or a homogeneous catalyst, but a solid catalyst is preferred from the viewpoint of separability from the reactants. Examples of solid catalysts include unsupported metal catalysts and supported metal catalysts. Examples of unsupported metal catalysts include sponge metal catalysts such as sponge nickel, sponge cobalt, and sponge copper, as well as oxides or colloidal catalysts of platinum, palladium, rhodium, ruthenium, and the like.Examples of supported metal catalysts include those in which at least one of iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold is supported on or mixed with a carrier such as magnesia, zirconia, ceria, diatomaceous earth, activated carbon, alumina, silica, zeolite, or titania, and preferred are copper-chromium catalysts (Adkins catalysts), supported copper catalysts such as copper-zinc catalysts or copper-iron, supported platinum catalysts such as Pt / C and Pt / alumina, supported palladium catalysts such as Pd / C and Pd / alumina, supported ruthenium catalysts such as Ru / C and Ru / alumina, and supported rhodium catalysts such as Rh / C and Rh / alumina. Of these, catalysts containing at least one selected from the group consisting of nickel, cobalt, and ruthenium are more preferred in terms of reaction activity. The amount of catalyst used may vary depending on the type of catalyst, but is preferably 0.1 to 100% by mass, more preferably 1 to 20% by mass, relative to the amount of the nitrile represented by formula (4) as the raw material. The molar ratio of ammonia relative to the amount of the nitrile represented by formula (4) is preferably 2 to 150, more preferably 5 to 100, and even more preferably 8 to 80. Ammonia can also be used as a solvent, and there are no limitations on the form of ammonia, and it may be in the form of liquid ammonia, aqueous ammonia, or the like. The alicyclic diamine thus obtained is preferably purified by distillation. The distillation conditions may be appropriately adjusted by adjusting the pressure and temperature during distillation.

[0028] (Production method using a nitrile represented by formula (5) as a starting material) The type of hydrogenation and amination reaction in this step is not particularly limited, and may be any of a batch system, a semi-continuous system, a continuous system, or the like. The reaction temperature for the hydrogenation and amination reaction is preferably 40 to 300°C, more preferably 60 to 200°C. From the viewpoints of selectivity and reaction rate, it is even more preferably 70 to 180°C. The pressure during the hydrogenation and amination reaction is preferably 1 to 20 MPa, more preferably 2 MPa to 10 MPa. The hydrogenation and amination reaction can be carried out without a solvent, but a solvent may be used. Examples of solvents used during the hydrogenation and amination reaction include water; aromatic compounds such as benzene, o-dichlorobenzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; alcohols such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, ethylene glycol, and diethylene glycol; ethers such as dioxane, tetrahydrofuran, dimethoxyethane, and diglyme; and mixtures thereof. The amount of solvent used in the hydrogenation and amination reactions is preferably 0 to 30 times by mass, more preferably 0 to 20 times by mass, relative to the amount of the nitrile represented by formula (5). The catalyst used in the hydrogenation and reductive amination reactions is not particularly limited as long as it is a catalyst typically used in the hydrogenation of nitriles or the amination of alcohols. However, a catalyst containing at least one metal selected from Groups 8 to 11 of the Periodic Table is preferred. Specific examples include catalysts containing at least one metal selected from the group consisting of iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. The catalyst may be a solid catalyst or a homogeneous catalyst, but a solid catalyst is preferred from the viewpoint of separability from the reactants. Examples of solid catalysts include unsupported metal catalysts and supported metal catalysts. Examples of unsupported metal catalysts include sponge metal catalysts such as sponge nickel, sponge cobalt, and sponge copper, as well as oxides or colloidal catalysts of platinum, palladium, rhodium, ruthenium, and the like.Examples of supported metal catalysts include those in which at least one of iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold is supported on or mixed with a carrier such as magnesia, zirconia, ceria, diatomaceous earth, activated carbon, alumina, silica, zeolite, or titania, and preferred are copper-chromium catalysts (Adkins catalysts), supported copper catalysts such as copper-zinc catalysts or copper-iron, supported platinum catalysts such as Pt / C and Pt / alumina, supported palladium catalysts such as Pd / C and Pd / alumina, supported ruthenium catalysts such as Ru / C and Ru / alumina, and supported rhodium catalysts such as Rh / C and Rh / alumina. Of these, catalysts containing at least one selected from the group consisting of nickel, cobalt, and ruthenium are more preferred in terms of reaction activity. The amount of catalyst used may vary depending on the type of catalyst, but is preferably 0.1 to 100% by mass, more preferably 1 to 20% by mass, relative to the amount of the nitrile represented by formula (5) as the raw material. The molar ratio of ammonia relative to the amount of the nitrile represented by formula (5) is preferably 2 to 150, more preferably 5 to 100, and even more preferably 8 to 80. Ammonia can also be used as a solvent, and there are no limitations on the form of ammonia, and it may be in the form of liquid ammonia, aqueous ammonia, or the like. The alicyclic diamine thus obtained is preferably purified by distillation. The distillation conditions may be appropriately adjusted by adjusting the pressure and temperature during distillation.

[0029] <Production Method Using Heterocyclic Aldehyde or Heterocyclic Alcohol as a Raw Material, and Production Method Using Furfural or Furfuryl Alcohol as a Raw Material> A more preferred method for producing an alicyclic diamine is a method for producing an alicyclic diamine in which the nitrile represented by the general formula (4) or the nitrile represented by the general formula (5) is a nitrile obtained using a heterocyclic aldehyde represented by the following general formula (6) or a heterocyclic alcohol represented by the following general formula (7) as a raw material, and an even more preferred method for producing an alicyclic diamine is a method for producing an alicyclic diamine in which the nitrile is obtained using furfural or furfuryl alcohol as a raw material. The heterocyclic aldehyde represented by the following general formula (6) is preferably furfural, 2-furanacetaldehyde, 2-furanpropanal, 2-furanbutanal, or 2-furanpentanal, more preferably furfural. The heterocyclic alcohol represented by the following general formula (7) is preferably furfuryl alcohol, 2-furanethanol, 2-furanpropanol, 2-furanbutanol, or 2-furanpentanol, and more preferably furfuryl alcohol. The nitrile obtained here can be used as an intermediate raw material to obtain the desired alicyclic diamine through the hydrogenation and amination steps described above. Using furfural or furfuryl alcohol as a raw material is preferred because it increases the biomass content of the resulting alicyclic diamine. There are no limitations on the method for obtaining the nitrile represented by formula (4) or the nitrile represented by formula (5) from the heterocyclic aldehyde represented by formula (6) or the heterocyclic alcohol represented by the following general formula (7) as a raw material, as long as it ultimately yields the nitrile represented by formula (4) or the nitrile represented by formula (5). Among these, preferred methods are described in detail below. The method using the heterocyclic aldehyde represented by formula (6) as a raw material will be described first, followed by the method using the heterocyclic alcohol represented by formula (7) as a raw material.

[0030] (Production method using heterocyclic aldehyde as a raw material) Using a heterocyclic aldehyde represented by formula (6) as a raw material, as shown in the formula below, an acetalization reaction is performed using the heterocyclic aldehyde represented by formula (6) and neopentyl alcohol to obtain an acetal represented by formula (9) below (acetalization reaction step). Note that when n4 is 0 in formula (6) below, the heterocyclic aldehyde represented by formula (6) is furfural, and the furfural is preferably a biomass raw material. Next, a Diels-Alder reaction is performed using the acetal represented by formula (9) and the unsaturated nitrile represented by formula (8) to obtain a nitrile represented by formula (10) below (Diels-Alder reaction step). Next, as shown in the formula below, the olefin moiety of the nitrile represented by formula (10) is hydrogenated to obtain a nitrile represented by formula (11) below (olefin moiety hydrogenation step). Next, as shown in the following formula, the nitrile represented by formula (11) is deprotected to obtain a nitrile represented by formula (4) (acetal deprotection step). (In the formula, n3 is 0 to 4, and n4 is 0 to 4. In the formulas (4), (10), and (11), -(CH ２ ) ｎ３ -CN is bonded to a or b.) Next, each of the above steps will be explained.

[0031] (Acetalization Reaction Step) In this step, an acetal represented by formula (9) is obtained by acetalization using a heterocyclic aldehyde represented by formula (6) and neopentyl alcohol. The type of acetalization reaction is not particularly limited, and any method such as a batch method, semi-continuous method, or continuous method may be used. The reaction temperature of the acetalization reaction is preferably 40 to 180°C, and more preferably 60 to 120°C. The molar ratio of the heterocyclic aldehyde represented by formula (6) to neopentyl alcohol (heterocyclic aldehyde represented by formula (6):neopentyl alcohol) is preferably 12:2 to 1:10, more preferably 1:1 to 1:10, even more preferably 1:2 to 1:10, and even more preferably 1:2 to 1:4.

[0032] The acetalization reaction preferably uses an acid catalyst. Examples of acid catalysts include mineral acids such as sulfuric acid, hydrochloric acid, and phosphoric acid; sulfonic acids such as benzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, and ethanesulfonic acid; strongly acidic cation exchange resins such as Diaion and Amberlyst; and various other Lewis acids. The amount of catalyst is preferably 0.01 to 50 mass%, more preferably 0.1 to 10 mass%, relative to the amount of the heterocyclic aldehyde represented by formula (6). The acetalization reaction can be carried out without a solvent, but a solvent may also be used. Examples of solvents that can be used in the acetalization reaction include aromatic compounds such as benzene, o-dichlorobenzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; ethers such as dioxane, tetrahydrofuran, dimethoxyethane, and diglyme; and mixtures thereof. The amount of the solvent used in the acetalization reaction is preferably 0 to 30 times by mass, more preferably 0 to 10 times by mass, relative to the amount of the heterocyclic aldehyde represented by formula (6) which is the raw material in this step.

[0033] (Diels-Alder Reaction Step) In this step, a nitrile represented by formula (10) is obtained by Diels-Alder reaction using an acetal represented by formula (9) and an unsaturated nitrile represented by formula (8). Examples of unsaturated nitriles represented by formula (8) include acrylonitrile, 3-butenenitrile, 4-pentenenitrile, 5-hexenenitrile, and 6-heptenenitrile, with acrylonitrile being preferred. The Diels-Alder reaction method is not particularly limited, and may be any method such as a batch method, a semi-continuous method, or a continuous method. The reaction temperature of the Diels-Alder reaction is preferably 20 to 120°C, and more preferably 40 to 80°C. The reaction pressure is not particularly limited as long as it allows the reaction to proceed favorably, but is preferably 0 to 5 MPa, and more preferably 0 to 1 MPa. The molar ratio of the acetal to the unsaturated nitrile (acetal:unsaturated nitrile) is preferably 1:1 to 1:20, more preferably 1:3 to 1:10.

[0034] The Diels-Alder reaction is preferably carried out without a solvent, but a solvent may be used. Examples of solvents that can be used in the Diels-Alder reaction include water; aromatic compounds such as benzene, o-dichlorobenzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; alcohols such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, ethylene glycol, and diethylene glycol; ethers such as dioxane, tetrahydrofuran, dimethoxyethane, and diglyme; and mixtures thereof. The Diels-Alder reaction is preferably carried out without a catalyst, but a catalyst may be used. Examples of catalysts include Lewis acids, silica gel, zeolites, and alumina. Specific examples of Lewis acids used as catalysts include ZnCl. ２ , ZnI ２ , AlCl ３ , FeCl ３ The amount of the catalyst is preferably 0.001 to 1 molar amount, more preferably 0.01 to 0.2 molar amount, relative to the amount of the acetal represented by formula (9).

[0035] In formula (10), a and b represent the carbon atoms and the positions of the carbon atoms in the hydrocarbon ring. ２ ) ｎ３Because —CN is bonded to a or b, the nitrile represented by formula (10) exists as two structural isomers. Each of the two structural isomers of the nitrile represented by formula (10) includes two stereoisomers (exo and endo), and the nitrile may be either one of the stereoisomers or a mixture of the two stereoisomers. Typically, the Diels-Alder reaction yields two nitriles as described above, but this mixture can be used as is as a raw material for the next step. Using the mixture ultimately yields an alicyclic diamine composition containing an alicyclic diamine represented by formula (1a) and an alicyclic diamine represented by formula (1b). However, when the alicyclic diamine composition is the desired product, it is preferable to use the mixture as a raw material for the next step for simplicity. The two nitriles can be separated and used individually as raw materials for the next step, or the ratio of the two nitriles can be adjusted and used as a raw material for the next step.

[0036] (Step of Hydrogenating Olefin Moiety) In this step, the olefin moiety of the nitrile represented by formula (10) is hydrogenated to obtain a nitrile represented by formula (11). The hydrogenation reaction of the olefin moiety is not particularly limited, and may be performed in any manner, such as batchwise, semi-continuously, or continuously. The reaction temperature of the hydrogenation reaction is preferably 0 to 100°C, more preferably 20 to 60°C. The pressure during the hydrogenation reaction is preferably 0.1 to 20 MPa, more preferably 0.5 to 3 MPa. The hydrogenation reaction can be performed without a solvent, but a solvent may also be used. Solvents that can be used in the hydrogenation reaction include water; aromatic compounds such as benzene, o-dichlorobenzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; alcohols such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, ethylene glycol, and diethylene glycol; ethers such as dioxane, tetrahydrofuran, dimethoxyethane, and diglyme; and mixtures thereof. The amount of the solvent used in the hydrogenation reaction is preferably 0 to 30 times by mass, more preferably 0 to 20 times by mass, relative to the amount of the nitrile represented by formula (10) that is the raw material in this step.

[0037] The catalyst used in the hydrogenation reaction is not particularly limited as long as it is a typical catalyst used in the hydrogenation of olefins, but a catalyst containing at least one metal selected from Groups 8 to 11 of the Periodic Table is preferred. Specific examples include hydrogenation catalysts containing at least one metal selected from the group consisting of iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. The hydrogenation catalyst may be a solid catalyst or a homogeneous catalyst, but a solid catalyst is preferred from the viewpoint of separability from the reactants. Examples of solid catalysts include unsupported metal catalysts and supported metal catalysts. Preferred unsupported metal catalysts are sponge metal catalysts such as sponge nickel, sponge cobalt, and sponge copper, or oxides or colloidal catalysts of platinum, palladium, rhodium, ruthenium, etc. Examples of supported metal catalysts include those in which at least one of iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold is supported on or mixed with a carrier such as magnesia, zirconia, ceria, diatomaceous earth, activated carbon, alumina, silica, zeolite, or titania, and preferred are copper-chromium catalysts (Adkins catalysts), supported copper catalysts such as copper-zinc catalysts or copper-iron, supported platinum catalysts such as Pt / C and Pt / alumina, supported palladium catalysts such as Pd / C and Pd / alumina, supported ruthenium catalysts such as Ru / C and Ru / alumina, and supported rhodium catalysts such as Rh / C and Rh / alumina. Of these, catalysts containing at least one selected from the group consisting of palladium and nickel are more preferred in terms of reaction activity. The amount of the hydrogenation catalyst used varies depending on the type of catalyst, but is preferably 0.1 to 100% by mass, more preferably 0.1 to 5% by mass, based on the nitrile represented by formula (10) which is the raw material in this step.

[0038] In formula (11), a and b represent the carbon atoms and the positions of the carbon atoms in the hydrocarbon ring. ２ ) ｎ３Because —CN is bonded to a or b, the nitrile represented by formula (11) exists in two structural isomers. Furthermore, each of the two structural isomers of the nitrile represented by formula (11) includes two stereoisomers (exo and endo), and the nitrile may be either one of the stereoisomers or a mixture of the two stereoisomers. When a mixture of the two structural isomers is used as the nitrile represented by formula (10), which is the raw material in this step, a mixture of structural isomers of the nitrile represented by formula (11) is obtained in this step. This mixture may be used as is as the raw material in the next step. Using the mixture ultimately produces an alicyclic diamine composition containing an alicyclic diamine represented by formula (1a) and an alicyclic diamine represented by formula (1b). However, when an alicyclic diamine composition is the desired product, it is preferable to use the mixture as the raw material in the next step for simplicity. The two types of nitriles may be separated and used individually as raw materials in the next step, or the ratio of the two types of nitriles may be adjusted and used as raw materials in the next step.

[0039] (Acetal Deprotection Step) In this step, a nitrile represented by formula (11) is deprotected to obtain a nitrile represented by formula (4) below. The deprotection is preferably carried out by hydrolysis in the presence of an acid catalyst. The type of acetal deprotection reaction is not particularly limited, and any method such as a batch method, a semi-continuous method, or a continuous method may be used. The reaction temperature for the acetal deprotection reaction is preferably 10 to 150°C, more preferably 30 to 100°C. The acetal deprotection reaction is carried out in the presence of water, but other solvents may be used in combination. Examples of solvents that can be used in combination in the acetal deprotection reaction include aromatic compounds such as benzene, o-dichlorobenzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; alcohols such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, ethylene glycol, and diethylene glycol; ethers such as dioxane, tetrahydrofuran, dimethoxyethane, and diglyme; and mixtures thereof. The amount of water used in the deprotection reaction of the acetal is preferably 0.1 to 30 times by mass, more preferably 1 to 10 times by mass, relative to the nitrile represented by formula (11) which is the raw material in this step. The amount of solvent used in the deprotection reaction of the acetal is preferably 0 to 30 times by mass, more preferably 0 to 10 times by mass, relative to the nitrile represented by formula (11) which is the raw material in this step. Examples of acid catalysts include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, and nitric acid; organic acids such as formic acid, acetic acid, oxalic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid; and Lewis acids such as aluminum trichloride, aluminum ethoxide, aluminum isopropoxide, aluminum oxide, boron trifluoride, boron trichloride, boron tribromide, magnesium chloride, magnesium bromide, magnesium iodide, zinc chloride, zinc bromide, zinc iodide, tin tetrachloride, tin tetrabromide, dibutyltin dichloride, dibutyltin dimethoxide, dibutyltin oxide, titanium tetrachloride, titanium tetrabromide, titanium(IV) methoxide, titanium(IV) ethoxide, titanium(IV) isopropoxide, and titanium(IV) oxide. One or more types of acid catalysts may be used, as needed. Furthermore, commercially available acid catalysts may be used.The amount of the catalyst is preferably 0.001 to 100 times by mole, more preferably 0.1 to 30 times by mole, relative to the amount of the nitrile represented by formula (11).

[0040] (Production method using heterocyclic alcohol as a raw material) When a heterocyclic alcohol represented by formula (7) is used as a starting material in this production method, first, a heterocyclic aldehyde represented by formula (6) is hydrogenated to obtain a heterocyclic alcohol represented by formula (7). Note that when n2 is 1 in the following formula (7), the heterocyclic alcohol represented by formula (7) is furfuryl alcohol, and furfuryl alcohol is preferably a biomass raw material. Next, a Diels-Alder reaction is performed using the heterocyclic alcohol represented by formula (7) and the unsaturated nitrile represented by formula (8) to obtain a nitrile represented by formula (12) below (Diels-Alder reaction step). Next, as shown in the following formula, the olefin moiety of the nitrile represented by formula (12) is hydrogenated to obtain a nitrile represented by formula (5) below (olefin moiety hydrogenation step). (In the formula, n2 is 1 to 5, and n3 is 0 to 4. In the formulas (5) and (12), -(CH ２ ) ｎ３ -CN is bonded to a or b.) Next, each of the above steps will be explained.

[0041] (Diels-Alder Reaction Step) In this step, a heterocyclic alcohol represented by formula (7) and an unsaturated nitrile represented by formula (8) are subjected to a Diels-Alder reaction to obtain a nitrile represented by formula (12). Examples of unsaturated nitriles represented by formula (8) include acrylonitrile, 3-butenenitrile, 4-pentenenitrile, 5-hexenenitrile, and 6-heptenenitrile, with acrylonitrile being preferred. The Diels-Alder reaction method is not particularly limited, and may be any method such as a batch method, a semi-continuous method, or a continuous method. The reaction temperature of the Diels-Alder reaction is preferably 20 to 120°C, and more preferably 40 to 80°C. The reaction pressure is not particularly limited as long as it allows the reaction to proceed favorably, but is preferably 0 to 5 MPa, and more preferably 0 to 1 MPa. The molar ratio of the heterocyclic alcohol represented by formula (7) to the unsaturated nitrile represented by formula (8) (heterocyclic alcohol:unsaturated nitrile) is preferably 1:1 to 1:20, more preferably 1:3 to 1:10.

[0042] The Diels-Alder reaction is preferably carried out without a solvent, but a solvent may be used. Examples of solvents that can be used in the Diels-Alder reaction include water; aromatic compounds such as benzene, o-dichlorobenzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; alcohols such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, ethylene glycol, and diethylene glycol; ethers such as dioxane, tetrahydrofuran, dimethoxyethane, and diglyme; and mixtures thereof. The Diels-Alder reaction is preferably carried out without a catalyst, but a catalyst may be used. Examples of catalysts include Lewis acids, silica gel, zeolites, and alumina. Specific examples of Lewis acids used as catalysts include ZnCl. ２ , ZnI ２ , AlCl ３ , FeCl ３The amount of the catalyst is preferably 0.001 to 1 molar amount, more preferably 0.01 to 0.2 molar amount, relative to the amount of the heterocyclic alcohol represented by formula (7).

[0043] In formula (12), a and b represent the carbon atoms and the positions of the carbon atoms in the hydrocarbon ring. ２ ) ｎ３ Because —CN is bonded to a or b, the nitrile represented by formula (12) exists in two structural isomers. Furthermore, each of the two structural isomers of the nitrile represented by formula (12) includes two stereoisomers (exo and endo), and the nitrile may be either one of the stereoisomers or a mixture of the two stereoisomers. Typically, the Diels-Alder reaction yields two types of nitriles as described above, but this mixture may be used as is as a raw material for the next step. Using the mixture ultimately yields an alicyclic diamine composition containing an alicyclic diamine represented by formula (1a) and an alicyclic diamine represented by formula (1b). However, when an alicyclic diamine composition is the desired product, it is preferable to use the mixture as a raw material for the next step for simplicity. The two types of nitriles may be separated and used individually as raw materials for the next step, or the ratio of the two types of nitriles may be adjusted and used as a raw material for the next step.

[0044] (Step of Hydrogenating Olefin Moiety) In this step, the olefin moiety of the nitrile represented by formula (12) is hydrogenated to obtain a compound represented by formula (5). The hydrogenation reaction method for the olefin moiety is not particularly limited, and may be any method such as a batch method, a semi-continuous method, or a continuous method. The reaction temperature for the hydrogenation reaction is preferably 0 to 100°C, more preferably 20 to 60°C. The pressure during the hydrogenation reaction is preferably 0.1 to 20 MPa, more preferably 0.5 to 3 MPa. The hydrogenation reaction can be carried out without a solvent, but a solvent may also be used. Solvents that can be used in the hydrogenation reaction include water; aromatic compounds such as benzene, o-dichlorobenzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; alcohols such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, ethylene glycol, and diethylene glycol; ethers such as dioxane, tetrahydrofuran, dimethoxyethane, and diglyme; and mixtures thereof. The amount of the solvent used in the hydrogenation reaction is preferably 0 to 30 times by mass, more preferably 0 to 20 times by mass, relative to the amount of the nitrile represented by formula (12) that is the raw material in this step.

[0045] The catalyst used in the hydrogenation reaction is not particularly limited as long as it is a typical catalyst used in the hydrogenation of olefins, but a catalyst containing at least one metal selected from Groups 8 to 11 of the Periodic Table is preferred. Specific examples include hydrogenation catalysts containing at least one metal selected from the group consisting of iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. The hydrogenation catalyst may be a solid catalyst or a homogeneous catalyst, but a solid catalyst is preferred from the viewpoint of separability from the reactants. Examples of solid catalysts include unsupported metal catalysts and supported metal catalysts. Preferred unsupported metal catalysts are sponge metal catalysts such as sponge nickel, sponge cobalt, and sponge copper, or oxides or colloidal catalysts of platinum, palladium, rhodium, ruthenium, etc. Examples of supported metal catalysts include those in which at least one of iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold is supported on or mixed with a carrier such as magnesia, zirconia, ceria, diatomaceous earth, activated carbon, alumina, silica, zeolite, or titania, and preferred are copper-chromium catalysts (Adkins catalysts), supported copper catalysts such as copper-zinc catalysts or copper-iron, supported platinum catalysts such as Pt / C and Pt / alumina, supported palladium catalysts such as Pd / C and Pd / alumina, supported ruthenium catalysts such as Ru / C and Ru / alumina, and supported rhodium catalysts such as Rh / C and Rh / alumina. Of these, catalysts containing at least one selected from the group consisting of palladium and nickel are more preferred in terms of reaction activity. The amount of the hydrogenation catalyst used varies depending on the type of catalyst, but is preferably 0.1 to 100% by mass, more preferably 0.1 to 5% by mass, based on the amount of the compound represented by formula (12) which is the raw material in this step.

[0046] In formula (5), a and b represent the carbon atoms and the positions of the carbon atoms in the hydrocarbon ring. ２ ) ｎ３Because —CN is bonded to a or b, the nitrile represented by formula (5) exists as two structural isomers. Each of the two structural isomers of the nitrile represented by formula (5) includes two stereoisomers (exo and endo), and the nitrile may be either one of the stereoisomers or a mixture of the two stereoisomers. When a mixture of the two structural isomers is used as the nitrile represented by formula (12), which is the raw material in this step, a mixture of structural isomers of the nitrile represented by formula (5) is obtained in this step. This mixture may be used as is as the raw material in the next step. Using the mixture ultimately produces an alicyclic diamine composition containing an alicyclic diamine represented by formula (1a) and an alicyclic diamine represented by formula (1b). However, when an alicyclic diamine composition is the desired product, it is preferable to use the mixture as the raw material in the next step for simplicity. The two types of nitriles may be separated and used individually as raw materials in the next step, or the ratio of the two types of nitriles may be adjusted and used as raw materials in the next step.

[0047] [Epoxy Resin Curing Agent] The alicyclic diamine and alicyclic diamine composition can be suitably used as epoxy resin curing agents, and when used as an epoxy resin curing agent, the resulting coating film of the epoxy resin composition can have excellent adhesion. Furthermore, a reaction product obtained by reacting the alicyclic diamine or alicyclic diamine composition with an epoxy compound can also be suitably used as an epoxy resin curing agent, and when used as an epoxy resin curing agent, the resulting coating film of the epoxy resin composition can have excellent adhesion. Furthermore, modified products obtained by the Mannich reaction of the alicyclic diamine or alicyclic diamine composition with a phenolic compound and an aldehyde compound, modified products obtained by the reaction of the alicyclic diamine or alicyclic diamine composition with a compound having a carboxyl group, and modified products obtained by the Michael reaction of the alicyclic diamine or alicyclic diamine composition with an acrylic compound can also be suitably used as epoxy resin curing agents, and when used as an epoxy resin curing agent, the resulting coating film of the epoxy resin composition can have excellent adhesion.Therefore, the epoxy resin curing agent of the present invention is preferably a curing agent selected from the group consisting of the alicyclic diamine, the alicyclic diamine composition, a reaction product of an epoxy compound having at least one epoxy group with the alicyclic diamine, a reaction product of an epoxy compound having at least one epoxy group with the alicyclic diamine composition, a modified product obtained by the Mannich reaction of the alicyclic diamine with a phenolic compound and an aldehyde compound, a modified product obtained by the reaction of the alicyclic diamine with a compound having a carboxyl group, a modified product obtained by the Michael reaction of the alicyclic diamine with an acrylic compound, a modified product obtained by the reaction of the alicyclic diamine composition with a phenolic compound and an aldehyde compound, a modified product obtained by a Mannich reaction between the alicyclic diamine composition and a compound having a carboxyl group, and a modified product obtained by a Michael reaction between the alicyclic diamine composition and an acrylic compound; and more preferably, an epoxy resin curing agent containing at least one selected from the group consisting of the alicyclic diamine, the alicyclic diamine composition, a reaction product between an epoxy compound having at least one epoxy group and the alicyclic diamine, and a reaction product between an epoxy compound having at least one epoxy group and the alicyclic diamine composition.

[0048]

[0033] The epoxy resin curing agent of the present invention usually contains any one of the alicyclic diamine, the alicyclic diamine composition, a reaction product of the epoxy compound and the alicyclic diamine, a reaction product of the epoxy compound and the alicyclic diamine composition, a modified product obtained by the Mannich reaction of the alicyclic diamine with a phenolic compound and an aldehyde compound, a modified product obtained by the reaction of the alicyclic diamine with a compound having a carboxyl group, a modified product obtained by the Michael reaction of the alicyclic diamine with an acrylic compound, a modified product obtained by the Mannich reaction of the alicyclic diamine composition with a phenolic compound and an aldehyde compound, a modified product obtained by the reaction of the alicyclic diamine composition with a compound having a carboxyl group, and a modified product obtained by the Michael reaction of the alicyclic diamine composition with an acrylic compound, but may contain two or more of them.

[0049] The epoxy resin curing agent of the present invention may further contain a known non-reactive diluent, etc., as long as the effects of the present invention are not impaired. Examples of non-reactive diluents include benzyl alcohol, furfuryl alcohol, tetrafurfuryl alcohol, and aromatic hydrocarbon formaldehyde resins, and one or more of these can be used. Aromatic hydrocarbon formaldehyde resins are resins obtained by reacting aromatic hydrocarbons with formaldehyde, and examples include toluene formaldehyde resins obtained by reacting toluene with formaldehyde, xylene formaldehyde resins obtained by reacting xylene with formaldehyde, mesitylene formaldehyde resins obtained by reacting mesitylene with formaldehyde, and pseudocumene formaldehyde resins obtained by reacting pseudocumene with formaldehyde. Commercially available aromatic hydrocarbon formaldehyde resins include, for example, xylene formaldehyde resins manufactured by Fudoh Co., Ltd., such as "Nikanol Y-50," "Nikanol Y-100," "Nikanol Y-300," "Nikanol Y-1000," "Nikanol L," "Nikanol LL," "Nikanol LLL," "Nikanol G," "Nikanol H," and "Nikanol H-80." Among the above, preferred is at least one selected from the group consisting of benzyl alcohol and aromatic hydrocarbon formaldehyde resins, more preferred is at least one selected from the group consisting of benzyl alcohol and xylene formaldehyde resins, even more preferred is benzyl alcohol, and even more preferred is benzyl alcohol.

[0050] The content of the non-reactive diluent is preferably 1 to 99% by mass, more preferably 10 to 90% by mass, even more preferably 20 to 70% by mass, still more preferably 30 to 60% by mass, and still more preferably 35 to 50% by mass.

[0051] The upper limit of the total content of the alicyclic diamine, the alicyclic diamine composition, the reaction product of the epoxy compound and the alicyclic diamine, and the reaction product of the epoxy compound and the alicyclic diamine composition used in the epoxy resin curing agent of the present invention is not particularly limited, as long as it is 100% by mass or less, but is preferably 1 to 99% by mass, more preferably 10 to 90% by mass, even more preferably 30 to 80% by mass, still more preferably 40 to 70% by mass, and still more preferably 50 to 65% by mass.

[0052] The method for preparing the epoxy resin curing agent of the present invention is not particularly limited, and can be appropriately selected depending on the form of use, the equipment used, the types and blending ratios of the components, etc. For example, the curing agent can be prepared by blending and mixing the alicyclic diamine, the alicyclic diamine composition, the reaction product of the epoxy compound and the alicyclic diamine, or the reaction product of the epoxy compound and the alicyclic diamine composition, with other curing agent components, a non-reactive diluent, etc., which are used as needed. Furthermore, the curing agent may be prepared by simultaneously mixing the components contained in the epoxy resin curing agent with the epoxy resin when preparing the epoxy resin composition.

[0053] When the epoxy resin curing agent of the present invention contains a reaction product of an epoxy compound having at least one epoxy group with the alicyclic diamine, or a reaction product of an epoxy compound having at least one epoxy group with the alicyclic diamine composition, the "epoxy compound having at least one epoxy group" may be a compound having at least one epoxy group, and is preferably a compound having two or more epoxy groups. Specific examples of the epoxy compound include epichlorohydrin, butyl diglycidyl ether, neopentyl glycol diglycidyl ether, 1,3-propanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, biphenol diglycidyl ether, dihydroxynaphthalene diglycidyl ether, dihydroxyanthracene diglycidyl ether, triglycidyl isocyanurate, tetraglycidyl glycoluril, a polyfunctional epoxy resin having a glycidylamino group derived from metaxylylenediamine, and a glycidylamino group derived from 1,3-bis(aminomethyl)cyclohexane. Examples of suitable epoxy resins include polyfunctional epoxy resins having glycidylamino groups, polyfunctional epoxy resins having glycidylamino groups derived from diaminodiphenylmethane, polyfunctional epoxy resins having glycidylamino groups derived from para-aminophenol, polyfunctional epoxy resins having glycidyloxy groups derived from para-aminophenol, polyfunctional epoxy resins having glycidyloxy groups derived from bisphenol A, polyfunctional epoxy resins having glycidyloxy groups derived from bisphenol F, polyfunctional epoxy resins having glycidyloxy groups derived from phenol novolac, and polyfunctional epoxy resins having two or more glycidyloxy groups derived from resorcinol. These may be used alone or in combination of two or more. From the viewpoints of forming an epoxy resin cured product having excellent chemical resistance and curability, epoxy compounds containing an aromatic ring or alicyclic structure in the molecule are more preferred, and compounds containing an aromatic ring in the molecule are even more preferred, with polyfunctional epoxy resins having glycidyloxy groups derived from bisphenol A being even more preferred.

[0054] The reaction product of the epoxy compound and the alicyclic diamine or alicyclic diamine composition can be obtained by a ring-opening addition reaction using a known method. For example, a reactor is charged with the alicyclic diamine or alicyclic diamine composition, and the epoxy compound is added all at once or in portions by dropwise addition, followed by heating and reaction. The addition reaction is preferably carried out under an inert atmosphere such as nitrogen gas.

[0055] The amounts of the alicyclic diamine or alicyclic diamine composition and the epoxy compound used are not particularly limited as long as the ratio is such that the resulting reaction product contains an amino group having active hydrogen, but from the viewpoint of enabling the resulting reaction product to function as an epoxy resin curing agent, it is preferable to use an excess amount of the alicyclic diamine or alicyclic diamine composition relative to the epoxy equivalent of the epoxy compound in the addition reaction. Specifically, the alicyclic diamine or alicyclic diamine composition and the epoxy compound are used so that the ratio [D] / [G] is preferably 50 / 1 to 4 / 1, more preferably 20 / 1 to 8 / 1 (where [D] represents the number of active hydrogens in the alicyclic diamine or alicyclic diamine composition, and [G] represents the number of epoxy groups in the epoxy compound).

[0056] The temperature and reaction time during the addition reaction can be appropriately selected, but from the viewpoints of reaction rate, productivity, and prevention of decomposition of raw materials, the temperature during the addition reaction is preferably 50 to 150° C., more preferably 70 to 120° C. The reaction time is preferably 0.5 to 12 hours, more preferably 1 to 6 hours, from the completion of addition of the epoxy compound.

[0057] The epoxy resin curing agent of the present invention preferably has a biomass degree of 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, and even more preferably 90% by mass or more. There is no upper limit, but it is 100% by mass or less, and even more preferably 100% by mass. As described above, the alicyclic diamine and alicyclic diamine composition contained in the epoxy resin curing agent can be obtained using biomass-derived furfural or furfuryl alcohol as raw materials. By using biomass-derived raw materials including these, the biomass degree can be adjusted to the above range. The biomass degree is the mass proportion of the biomass raw materials among the raw materials that contribute to the structure of the resulting alicyclic diamine.

[0058] The method for preparing the epoxy resin curing agent of the present invention is not particularly limited, and can be appropriately selected depending on the form of use, the equipment used, the types and blending ratios of the components, etc. For example, the curing agent can be prepared by blending and mixing the alicyclic diamine or alicyclic diamine composition with other curing agent components, non-reactive diluents, etc., which are used as needed. Furthermore, the curing agent may be prepared by simultaneously mixing the components contained in the epoxy resin curing agent with the epoxy resin when preparing the epoxy resin composition.

[0059] The epoxy resin curing agent of the present invention can be mixed with an epoxy resin to obtain an epoxy resin composition that serves as a raw material for a cured product.

[0060] The epoxy resin may be any of a saturated or unsaturated aliphatic compound, an alicyclic compound, an aromatic compound, and a heterocyclic compound. From the viewpoint of obtaining a cured product with a high Tg (glass transition temperature), an epoxy resin containing an aromatic ring or an alicyclic structure in the molecule is preferred. Specific examples of the epoxy resin include at least one resin selected from the group consisting of epoxy resins having a glycidylamino group derived from meta-xylylenediamine, epoxy resins having a glycidylamino group derived from para-xylylenediamine, epoxy resins having a glycidylamino group derived from 1,3-bis(aminomethyl)cyclohexane, epoxy resins having a glycidylamino group derived from 1,4-bis(aminomethyl)cyclohexane, epoxy resins having a glycidylamino group derived from diaminodiphenylmethane, epoxy resins having a glycidylamino group and / or a glycidyloxy group derived from para-aminophenol, epoxy resins having a glycidyloxy group derived from bisphenol A, epoxy resins having a glycidyloxy group derived from bisphenol F, epoxy resins having a glycidyloxy group derived from phenol novolac, and epoxy resins having a glycidyloxy group derived from resorcinol. Two or more of the above epoxy resins can also be used in combination.

[0061] Among the above, from the viewpoint of obtaining a cured product with a high Tg, preferred epoxy resins are those containing, as a main component, at least one selected from the group consisting of epoxy resins having a glycidylamino group derived from meta-xylylenediamine, epoxy resins having a glycidylamino group derived from para-xylylenediamine, epoxy resins having a glycidyloxy group derived from bisphenol A, and epoxy resins having a glycidyloxy group derived from bisphenol F. From the viewpoint of obtaining a cured product with a high Tg, availability, and economy, more preferred are those containing, as a main component, an epoxy resin having a glycidyloxy group derived from bisphenol A. Note that the term "main component" as used herein means that other components may be contained within a range that does not deviate from the spirit of the present invention, and preferably means 50 to 100 mass%, more preferably 70 to 100 mass%, and even more preferably 90 to 100 mass% of the total.

[0062] The content of the epoxy resin curing agent in the epoxy resin composition is an amount such that the ratio of the number of active hydrogens in the epoxy resin curing agent to the number of epoxy groups in the epoxy resin (number of active hydrogens in the epoxy resin curing agent / number of epoxy groups in the epoxy resin) is preferably 1 / 0.5 to 1 / 2, more preferably 1 / 0.75 to 1 / 1.5, and even more preferably 1 / 0.8 to 1 / 1.2.

[0063] The epoxy resin composition may further contain other components such as fillers, modifying components such as plasticizers, flow-adjusting components such as thixotropic agents, pigments, leveling agents, tackifiers, and elastomer fine particles depending on the intended use. The total amount of the epoxy resin and epoxy resin curing agent in the epoxy resin composition is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more. The upper limit is 100% by mass.

[0064] The epoxy resin composition can be prepared by mixing an epoxy resin, an epoxy resin curing agent, and other components as needed using known methods and devices. The order of mixing the components contained in the epoxy resin composition is also not particularly limited. The epoxy resin curing agent may be prepared and then mixed with the epoxy resin, or the components constituting the epoxy resin curing agent and the epoxy resin may be simultaneously mixed to prepare the composition.

[0065] An epoxy resin cured product can be obtained by curing the epoxy resin composition by a known method. The curing conditions for the epoxy resin composition are appropriately selected depending on the application and form. The cured product obtained as described above has excellent adhesion and is therefore particularly suitable for use in coating applications. Furthermore, it can also be used in fields other than coatings, such as flooring materials and linings, which come into contact with water. Furthermore, the epoxy resin composition has excellent drying properties, and the resulting cured product also has an excellent appearance.

[0066] [Uses of alicyclic diamine and alicyclic diamine composition] The alicyclic diamine and alicyclic diamine composition are novel alicyclic diamines and novel alicyclic diamine compositions, and are characterized by excellent solvent solubility, and therefore can be used in a variety of applications. Furthermore, when used as a resin raw material, it is believed that the resulting resin can be imparted with weather resistance and transparency. For example, they can be used as a raw material for polyamides, polyimides, polyurethanes, polyureas, ligands, etc. Next, each application will be described.

[0067] <Use as a Polyamide Raw Material> The alicyclic diamine and alicyclic diamine composition are novel alicyclic diamines and novel alicyclic diamine compositions, characterized by excellent solvent solubility, making them suitable for use as polyamide raw materials. Furthermore, the alicyclic diamine and alicyclic diamine composition are believed to impart weather resistance to the resulting polyamide. Polyamides can be obtained by introducing a diamine containing the alicyclic diamine or alicyclic diamine composition and a dicarboxylic acid into a reaction system and carrying out a polycondensation reaction. The dicarboxylic acid is not particularly limited, but is preferably at least one selected from aliphatic dicarboxylic acids having 4 to 20 carbon atoms, terephthalic acid, and isophthalic acid, more preferably aliphatic dicarboxylic acids having 4 to 20 carbon atoms, and even more preferably aliphatic dicarboxylic acids having 4 to 12 carbon atoms. Examples of aliphatic dicarboxylic acids having 4 to 20 carbon atoms include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid. Among these, at least one selected from adipic acid and sebacic acid is preferably used from the viewpoints of crystallinity and high elasticity. These dicarboxylic acids may be used alone or in combination of two or more. Examples of other dicarboxylic acids include aliphatic dicarboxylic acids having 3 or less carbon atoms, such as oxalic acid and malonic acid; and aromatic dicarboxylic acids other than terephthalic acid and isophthalic acid, such as 2,6-naphthalenedicarboxylic acid. The molar ratio of diamine to dicarboxylic acid (diamine / dicarboxylic acid) is preferably in the range of 0.9 to 1.1, more preferably in the range of 0.93 to 1.07, even more preferably in the range of 0.95 to 1.05, and still more preferably in the range of 0.97 to 1.02. When the molar ratio is within the above range, the polymerization of the polymer is facilitated.

[0068] <Use as a Polyimide Raw Material> The alicyclic diamine and alicyclic diamine composition are novel alicyclic diamines and novel alicyclic diamine compositions, and are characterized by excellent solvent solubility, making them suitable for use as polyimide raw materials. Furthermore, the alicyclic diamine and alicyclic diamine composition are believed to impart weather resistance to the resulting polyimide. Polyimides can be obtained by introducing a diamine containing the alicyclic diamine or alicyclic diamine composition and a tetracarboxylic acid dianhydride into a reaction system, subjecting the diamine to a ring-opening polyaddition reaction to obtain a polyamic acid, and then imidizing the polyamic acid. The ring-opening polyaddition reaction and imidization may be carried out simultaneously. The tetracarboxylic acid dianhydride is not particularly limited, but examples include aromatic tetracarboxylic acid dianhydrides, alicyclic tetracarboxylic acid dianhydrides, and aliphatic tetracarboxylic acid dianhydrides. Examples of aromatic tetracarboxylic dianhydrides include biphenyltetracarboxylic dianhydride (BPDA), 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), pyromellitic dianhydride, 3,3',4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, and 2,2',3,3'-benzophenonetetracarboxylic dianhydride. Examples of alicyclic tetracarboxylic dianhydrides that provide structural units derived from alicyclic tetracarboxylic dianhydrides include 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyltetracarboxylic dianhydride, 5,5'-bis-2-norbornene-5,5',6,6'-tetracarboxylic-5,5',6,6'-dianhydride, and positional isomers thereof. Examples of aliphatic tetracarboxylic dianhydrides that provide structural units derived from aliphatic tetracarboxylic dianhydrides include 1,2,3,4-butanetetracarboxylic dianhydride.These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

[0069] <Use as a polyurethane raw material> The alicyclic diamine and alicyclic diamine composition are novel alicyclic diamines and novel alicyclic diamine compositions, and are characterized by excellent solvent solubility, making them suitable for use as polyurethane raw materials. Furthermore, the alicyclic diamine and alicyclic diamine composition are believed to impart weather resistance to the resulting polyurethane. The alicyclic diamine and alicyclic diamine composition are first reacted with phosgene to obtain the corresponding isocyanate. Polyurethane can be obtained by reacting the resulting isocyanate with a polyol. The polyol is not particularly limited, and examples thereof include polyester polyols, polyether polyols, polycarbonate polyols, and polylactone polyols. Examples of polyester polyols include condensation polyester polyols such as polyethylene adipate glycol, polybutylene adipate glycol, polyhexamethylene adipate glycol, and polyethylene butylene adipate glycol. Examples of polyether polyols include aliphatic polyether polyols such as polytetramethylene glycol, polyethylene glycol, and polypropylene glycol. Examples of polycarbonate polyols include polyols obtained by dealcoholization reaction of low-molecular-weight polyols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, nonanediol, and 1,4-cyclohexanedimethanol with carbonate compounds such as diethylene carbonate, dipropylene carbonate, and diphenyl carbonate. Examples of polylactone polyols include polylactone diols obtained by ring-opening polymerization of lactones using the low-molecular-weight polyols listed above as initiators, as well as lactone polyester diols such as polycaprolactone diol and polymethylvalerolactone diol. The polyols can be used alone or in combination of two or more.

[0070] <Use as a raw material for polyurea> The alicyclic diamine and alicyclic diamine composition are novel alicyclic diamines and novel alicyclic diamine compositions, and are characterized by excellent solvent solubility, making them suitable for use as raw materials for polyurea. Furthermore, the alicyclic diamine and alicyclic diamine composition are believed to be able to impart weather resistance to the resulting polyurea. Polyurea can be obtained by reacting the alicyclic diamine and alicyclic diamine composition with a polyisocyanate. The polyisocyanate is not particularly limited as long as it contains a compound having two or more isocyanate groups. The polyisocyanate is preferably a diisocyanate having two or more isocyanate groups. Examples of diisocyanates having two isocyanate groups include aliphatic isocyanate compounds such as 1,6-hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, methylene diisocyanate, isopropylene diisocyanate, lysine diisocyanate methyl ester, and 1,5-octylene diisocyanate; 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate (IPDI), norbornene diisocyanate, hydrogenated tolylene diisocyanate, methylcyclohexane diisocyanate, and isopropylidene diisocyanate. alicyclic isocyanate compounds such as 4-cyclohexyl isocyanate and dimer acid diisocyanate; and aromatic isocyanate compounds such as 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate, p- or m-xylylene diisocyanate (XDI), tolidine diisocyanate, p-phenylene diisocyanate, diphenyl ether diisocyanate, diphenyl sulfone diisocyanate, dianisidine diisocyanate, and tetramethyl-m-xylylene diisocyanate.Examples of polyisocyanates having three or more isocyanate groups include triphenylmethane triisocyanate, triisocyanate phenylthiophosphate, polymethylene polyphenylene polyisocyanate (polymeric MDI), isocyanurate-modified products and biuret-modified products which are trimers of HDI or TDI, etc. Polyisocyanates can be used alone or in combination of two or more.

[0071] <Use as a Ligand> The alicyclic diamine and alicyclic diamine composition are novel alicyclic diamines and novel alicyclic diamine compositions, and are characterized by excellent solvent solubility, making them suitable for use as ligands. It is believed that the alicyclic diamine and alicyclic diamine composition, when used as ligands, can be used in metal catalysts, etc., and can also be used as chelating agents to remove or separate metal ions. The metals used as the metal ions are preferably Group 3 to Group 11 elements, more preferably transition metals, and even more preferably noble metals.

[0072] <Other Applications> The alicyclic diamine and alicyclic diamine composition of the present invention, and the polyamide resins, polyimide resins, polyurethane resins, polyurea resins, etc. using the alicyclic diamine or alicyclic diamine composition of the present invention can be used in a variety of applications, including various molded articles, various housings, paints, adhesives, composite materials, insulating materials, sealants, molding powders, liners, various coatings, water treatment agents, fiber treatment agents, dispersants, surfactants, bleaching agents, corrosion inhibitors, paper strength agents, connectors, CO ２ They can be used in various applications such as absorbents, dielectric materials, various films, electronic substrate materials, fiber materials, switches, etc. However, the applications of the alicyclic diamine and the alicyclic diamine composition of the present invention are not limited to the above applications.

[0073] EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. Analysis and evaluation of the alicyclic diamine compositions were carried out by the following methods.

[0074] <Gas Chromatography Analysis> Instrument used: Gas Chromatography 8860GC (Agilent Technologies, Inc.) Column: DB-1 (length 30 m, inner diameter 530 μm, film thickness 1.5 μm) Detector: FID (H 40 mL / min, Air 450 mL / min) Carrier gas: He Split ratio: 5:1 Injection port temperature: 250°C Detector temperature: 250°C Injection amount: 1.0 μL Oven temperature: After holding at 60°C for 6 minutes, the temperature was increased from 60°C to 280°C at a rate of 7°C / min, and after reaching 280°C, it was held for 20 minutes.

[0075] <GC-MS analysis> (GC side) Instrument used: Gas chromatograph GC2010 Plus (Shimadzu Corporation) Column: DB-1MS (length 30 m, inner diameter 0.25 mm, film thickness 0.25 μm) Carrier gas: He Split ratio: 5:1 Vaporization chamber temperature: 250°C Injection amount: 1 μL Oven temperature: After holding at 60°C for 6 minutes, the temperature was increased from 60°C to 280°C at 7°C / min, and after reaching 280°C, it was held for 20 minutes. (MS side) Instrument used: GCMS-QP2010 Ultra (Shimadzu Corporation) Fragmentation method: EI Ion source temperature: 200°C Interface temperature: 250°C

[0076] <Total Amine Value> The total amine value of the alicyclic diamine composition was measured by potentiometric titration in accordance with JIS-K-7237:1995 using an automatic potentiometric titrator "AT-710S" manufactured by Kyoto Electronics Manufacturing Co., Ltd. However, the sample solvent was changed from the o-nitrotoluene / acetic acid solution specified in JIS to acetic acid.

[0077] <Active Hydrogen Equivalent Weight (AHEW)> The AHEW of the alicyclic diamine composition and the epoxy resin curing agent was calculated from the total amine value determined using an automatic potentiometric titrator "AT-710S" manufactured by Kyoto Electronics Manufacturing Co., Ltd. The total amine value was measured using a 0.1 mol / L perchloric acid / acetic acid solution (manufactured by Kanto Chemical Co., Inc.).

[0078] <Structural Identification (NMR Analysis)> The structural identification of each component contained in the alicyclic diamine composition obtained in the Examples was carried out by NMR analysis under the following conditions. (NMR Analysis Method) Equipment used: AVANCE NEO 400 NMR device manufactured by Bruker Japan Co., Ltd. Resonance frequency: 400 MHz Mode: Proton ( １ H), Carbon( １３ C), HSQC ( １ H- １３ C) Measurement temperature: room temperature Solvent: CDCl3 (deuterated chloroform) Chemical shift reference substance: tetramethylsilane

[0079] <Evaluation of Adhesion (Cross-Cut Peel Test)> An epoxy resin composition was applied to a substrate (zinc phosphate-treated steel plate) using the same method as described below to form a coating film (thickness immediately after application: 200 μm). This coating film was then stored for 7 days under conditions of 23°C and 50% RH, and then 25 cross-cuts were made at 3 mm intervals using a utility knife. Cellophane tape was firmly pressed onto the cross-cut areas and then peeled off in one go. The state of the coating film at the cross-cut areas was observed after the cellophane tape was applied and peeled off once in each of the longitudinal and transverse directions, and the adhesion was evaluated according to the following criteria. (JIS Classification) In accordance with JIS-K-5600-5-6:1999 Adhesion (Cross-Cut Method), a six-level rating of 0 to 5 (JIS 0 to JIS 5) was used to evaluate adhesion in order of highest to lowest. (Number of Remaining Cross-Cuts) The number of remaining cross-cuts out of 25 was counted. The greater the number of remaining cross-cuts, the better the adhesion.

[0080] <Evaluation of Drying Properties (Dry to Touch)> A zinc phosphate-treated steel plate (SPCC-SD PB-N144, 0.8 mm x 70 mm x 150 mm, manufactured by Paltec Co., Ltd.) was used as the substrate. The epoxy resin composition was applied to the substrate using an applicator under conditions of 23°C and 50% RH to form a coating film (coating film thickness immediately after application: 200 μm). This coating film was stored under conditions of 23°C and 50% RH, and evaluated by touch after 1 and 7 days according to the following criteria. Ex: Excellent (the coating film is not sticky when pressed with a thumb at a force of about 50N, and no fingerprints remain) G: Good (the coating film is not sticky when pressed with a thumb at a force of about 50N, but fingerprints remain after touching) F: Fair (the coating film is sticky when pressed with a thumb at a force of about 50N) P: Poor (the coating film is sticky when pressed with a thumb at a force of about 5N)

[0081] <Appearance> Using the same method as above, an epoxy resin composition was applied to a substrate (zinc phosphate-treated steel plate) to form a coating film (thickness immediately after application: 200 μm). The appearance of the resulting coating film was visually observed one day later, and the smoothness and gloss were evaluated using the following criteria. (Transparency) Ex: Excellent (no cloudiness) G: Good (slight cloudiness, but no problems in use) F: Fair (slight cloudiness) P: Poor (cloudiness) (Gloss) Ex: Excellent (glossy) G: Good (slightly inferior gloss, but no problems in use) F: Fair (low gloss) P: Poor (no gloss)

[0082] Example 1 (Production of alicyclic diamine composition) (1) Acetalization reaction step Into a two-necked round-bottom flask equipped with a Dean-Stark trap and a stirrer, 150 g (1.56 mol) of furfural, 400 g (4.54 mol) of neopentyl alcohol, 5 g of Amberlyst-15 (a strongly acidic cation exchange resin), and 500 mL of toluene were added and mixed. The mixture was stirred under reflux for 3 hours and then cooled to room temperature. Next, Amberlyst-15 was removed by filtration under reduced pressure, and the filtrate was concentrated using an evaporator. The concentrated liquid was subjected to simple distillation to obtain 248 g of the acetal represented by formula (9-2).

[0083] (2) Diels-Alder reaction step (In formula (10-2), -CN is bonded to a and b.) In a 1000 mL two-neck flask equipped with a condenser, 248 g of the acetal represented by formula (9-2), 258.8 g of acrylonitrile, and ZnCl ２ 6.7 g of acrylonitrile was charged, heated to 60°C using an oil bath under a nitrogen atmosphere, and stirred with a stirrer to obtain a homogeneous solution. The reaction was carried out for 24 hours at a reaction temperature of 60°C while stirring. The reaction mixture was cooled, and acrylonitrile was removed using an evaporator. Next, water and ethyl acetate were added to the concentrate, and the organic layer was recovered by liquid separation and concentrated using an evaporator to obtain 265.8 g of the nitrile represented by formula (10-2). Note that "bonded to a and b" means that both the compound bonded to a and the compound bonded to b are included.

[0084] (3) Hydrogenation of the olefin portion (In the formula, -CN is bonded to a and b.) Next, 130 g of the nitrile represented by formula (10-2), 2.6 g of a 5 mass % Pd / C catalyst (water content: 56.7%), and 130 mL of ethyl acetate were charged into a 500 mL autoclave, and after the atmosphere inside the reactor was purged with nitrogen and hydrogen, hydrogen was introduced so that the hydrogen pressure became 1.0 MPa, and the reaction was carried out with stirring at a reaction temperature of 40°C for 2 hours. The reaction mixture was cooled, and the solvent was distilled off using an evaporator, yielding 120 g of the nitrile represented by formula (11-2).

[0085] (4) Acetal deprotection step (In the formula, -CN is bonded to a and b.) 120 g of the nitrile represented by formula (11-2) and 780 g of a formic acid / 10% by mass aqueous HCl solution (4 / 1 wt / wt) were placed in a 1000 mL two-neck flask equipped with a condenser, and the mixture was heated at 40°C for 3 hours. After heating, the mixture was concentrated using an evaporator. The concentrate was subjected to simple distillation to obtain 31 g of the nitrile represented by formula (5-2).

[0086] (5) Amination step (In formula (5-2), —CN is bonded to a and b. In formula (1-2), —CH ２ -NH ２is bonded to a and b.) 15 g of the nitrile represented by formula (5-2), 5 g of a sponge cobalt catalyst (RANEY 2724, manufactured by W.R. Grace), and 10 g of methanol were charged into a 200 mL autoclave. The reactor was purged with nitrogen and hydrogen, and then 60 g of liquid ammonia was added. Hydrogen was then introduced to a hydrogen pressure of 8.0 MPa, and the reaction was carried out at a reaction temperature of 80°C for 2 hours while stirring. The reaction mixture was cooled, the liquid ammonia was purged, and the powdered Raney cobalt catalyst was then filtered to recover the methanol solution. The methanol solution was then concentrated using an evaporator, yielding 14.2 g of a concentrate. Simple distillation was then performed to obtain an alicyclic diamine composition represented by formula (1-2). The alicyclic diamine composition represented by formula (1-2) is a mixture of an alicyclic diamine represented by formula (2) and an alicyclic diamine represented by formula (3). The purity was 99.9% as determined by the peak area in gas chromatography. The total amine value of the alicyclic diamine composition was 708.1 mg KOH / g, which was almost the same as the theoretical value of 718.7 mg KOH / g.

[0087] The NMR analysis results of the obtained alicyclic diamine composition are shown below. １ H- １３ C) By 1 It is confirmed whether each peak observed in the H-NMR spectrum is a proton signal derived from a hydrogen atom bonded to a carbon or a proton signal derived from a hydrogen atom bonded to a nitrogen, 13 It was confirmed which carbon signal each peak observed in the C-NMR spectrum belonged to. 1 H-NMR chemical shift: δ: 1.24 (s, 4H, [b]), 0.90-2.32 (m, 7H, [a]), 2.06-2.17 (m, 4H, [c]), 4.31-4.48 (m, 1H, [d]) 13 ​​C-NMR chemical shifts: δ: 25.55, 26.67, 30.93, 31.84, 31.88, 32.54, 37.53, 37.68, 37.98, 44.35, 44.55, 45.60, 45.81, 46.07, 46.15, 46.52, 46.71, 48.27, 75.43, 77.84, 78.12, 87.28, 87.87, 89.0. 25.55 to 37.98 are derived from the carbon atoms of [A]. 44.35 to 46.15 are derived from the carbon atoms of [B]. 46.52 to 48.27 are derived from the carbon atoms of [C]. 75.43 to 78.12 are derived from the carbon atoms of [D]. 87.28 to 89.0 are derived from the carbon atom of [E].

[0088] Furthermore, GC-MS analysis of the obtained alicyclic diamine composition showed that the molecular weight was 156, compared to 156.13 for each of the alicyclic diamines constituting the alicyclic diamine composition.

[0089] Example 2 (Preparation of Epoxy Resin Curing Agent) The alicyclic diamine composition was diluted with benzyl alcohol, a non-reactive diluent, in an amount of 40 mass % of the total, to obtain an epoxy resin curing agent with a concentration of the alicyclic diamine composition of 60 mass %. The active hydrogen equivalent (AHEW) derived from amino groups of the epoxy resin curing agent (total amount including benzyl alcohol) was 66 g / equivalent.

[0090] (Preparation and Evaluation of Epoxy Resin Compositions) A liquid epoxy resin having glycidyloxy groups derived from bisphenol A ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 186 g / equivalent) was used as the base epoxy resin. The epoxy resin and the epoxy resin curing agent were blended in the amounts shown in Table 1 and stirred and mixed at 23°C to prepare epoxy resin compositions. The ratio of the number of active hydrogens in the epoxy resin curing agent to the number of epoxy groups in the base epoxy resin (number of active hydrogens in epoxy resin curing agent / number of epoxy groups in base epoxy resin) was adjusted to 1 / 1. The resulting epoxy resin compositions were evaluated for drying properties, adhesion, and appearance using the methods described above. The results are shown in Table 1.

[0091] Comparative Examples 1 and 2 (Preparation and Evaluation of Epoxy Resin Compositions) Epoxy resin compositions were prepared and evaluated in the same manner as in Example 1, except that 1,3-BAC (1,3-bis(aminomethyl)cyclohexane) and IPDA (isophoronediamine) were used instead of the alicyclic diamine composition in Example 1. The results are shown in Table 1.

[0092]

[0093] Table 1 shows that coatings of epoxy resin compositions using epoxy resin curing agents containing the alicyclic diamines of the present invention have excellent adhesion. Furthermore, it is also clear that epoxy resin compositions using epoxy resin curing agents containing the alicyclic diamines of the present invention have excellent drying properties and appearance. It is clear that the alicyclic diamine and alicyclic diamine compositions of the present invention are particularly useful as epoxy resin curing agents. Therefore, the alicyclic diamine and alicyclic diamine compositions of the present invention, as well as the epoxy resin curing agents and epoxy resin compositions using them, can be suitably used in coating applications. Furthermore, they can also be suitably used in fields other than coatings, such as linings and adhesives, where high adhesion is desired.

Claims

1. Alicyclic diamines represented by the following general formula (1): (In formula (1), n1 is 1 to 5, n2 is 1 to 5, and —(CH ２ ) ｎ１ -NH ２ binds to a or b.) 2. The alicyclic diamine according to claim 1, wherein n1 is 1 and n2 is 1 in the formula (1).

3. In the formula (1), n1 is 1, n2 is 1, and -(CH ２ ) ｎ１ -NH ２ The alicyclic diamine of claim 1 , wherein 4. In the formula (1), n1 is 1, n2 is 1, and -(CH ２ ) ｎ１ -NH ２ The alicyclic diamine according to claim 1 , wherein 5. The alicyclic diamine according to any one of claims 1 to 4, having a biomass content of 30% by mass or more.

6. An alicyclic diamine composition containing an alicyclic diamine represented by the following formula (2) and an alicyclic diamine represented by the following formula (3):

7. The alicyclic diamine composition according to claim 6, having a biomass content of 30% by mass or more.

8. An epoxy resin curing agent containing at least one selected from the group consisting of the alicyclic diamine according to any one of claims 1 to 5, the alicyclic diamine composition according to claim 6 or 7, a reaction product of an epoxy compound having at least one epoxy group with the alicyclic diamine according to any one of claims 1 to 5, and a reaction product of an epoxy compound having at least one epoxy group with the alicyclic diamine composition according to claim 6 or 7.

9. The epoxy resin curing agent according to claim 8, having a biomass content of 30% by mass or more.

10. A method for producing an alicyclic diamine, comprising hydrogenating and amminating a nitrile represented by the following general formula (4) or a nitrile represented by the following general formula (5) to obtain an alicyclic diamine represented by the following general formula (1): (In formula (4), n3 is 0 to 4, n4 is 0 to 4, and —(CH ２ ) ｎ３ -CN is bonded to a or b. In formula (5), n2 is 1 to 5, n3 is 0 to 4, and -(CH ２ ) ｎ３ -CN is bonded to a or b. In formula (1), n1 is 1 to 5, n2 is 1 to 5, and -(CH ２ ) ｎ１ -NH ２ binds to a or b.) 11. The method for producing an alicyclic diamine according to claim 10, wherein the nitrile represented by the general formula (4) or the nitrile represented by the general formula (5) is a nitrile obtained using furfural or furfuryl alcohol as a raw material.

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