Amino compound and method for producing same, epoxy resin curing agent, epoxy resin composition and cured product thereof

Abstract

An amino compound represented by general formula (1), a method for producing the amino compound, an epoxy resin curing agent containing the amino compound, an epoxy resin composition, and a cured product of the epoxy resin composition. R1-NH-X-NH-R2 (1) (In the formula, R1 and R2 are each independently a hydrogen atom or a monovalent group represented by general formula (2), and at least one of R1 and R2 is a monovalent group represented by general formula (2). And X represents a divalent group represented by-CH2-A-CH2-(A represents a cyclohexylidene group),-(CH2) n-,-(CH2CH2NH) m-CH2CH2-, or a divalent group represented by general formula (3) or (4). N is 2-6, and m is 1 or 2. ) (In the formula, the dashed line represents the presence or absence of a pi bond, and each of R3-R5 independently represents a hydrogen atom or a C1-4 alkyl group optionally having a hydroxyl group. And * represents a connecting bond. ) (In the formula, * represents a linking bond. > # imgabs0 #

Description

Technical Field

[0001] The present invention relates to an amino compound and a method for producing the same, an epoxy resin curing agent, an epoxy resin composition and a cured product thereof. Background Art

[0002] As one type of epoxy resin curing agent, polyamine compounds are known. Epoxy resin compositions using polyamine compounds as epoxy resin curing agents are also used in the fields of coatings such as anti-corrosion coatings for ships / bridges / land and sea iron structures, lining / reinforcement / repair materials for concrete structures, floor materials for buildings, linings for waterways and sewage pipes, paving materials, adhesives, and other civil engineering / construction fields.

[0003] Among them, it is important for epoxy resin compositions for coatings that the resulting coating film has good appearance, water resistance, chemical resistance, coating film physical properties, and the like.

[0004] Bis(aminomethyl)cyclohexane, a type of aliphatic polyamine compound, has fast curing properties when used as an epoxy resin curing agent, and a coating film obtained by curing an epoxy resin composition containing the epoxy curing agent at room temperature has excellent weather resistance. However, it is known that the coating film becomes sticky on the surface due to amine blushing and causes a decrease in water resistance.

[0005] As a method for improving the reduction in water resistance due to the above-mentioned amine blushing, the use of a modified product of bis(aminomethyl)cyclohexane as an epoxy resin curing agent has been studied.

[0006] For example, Patent Document 1 discloses an epoxy resin curing agent which is prepared by reacting a specified maleic acid or fumaric acid derivative with a specified polyoxyalkyleneamine in a specific ratio, and further adding a specified amount of a polyamine compound such as bis(aminomethyl)cyclohexane to react. Patent Document 1 states that the curing agent is not easily affected by carbon dioxide (stickiness and whitening of the surface of the cured product).

[0007] Patent document 2 discloses a curing agent composition for epoxy resin, which contains: a polyamine compound which is a reaction product of a compound having at least one glycidyl group in one molecule and a diamine such as bis(aminomethyl)cyclohexane, a specified polyether-modified polysiloxane, and a specified amino-modified polysiloxane. The composition can solve the problem of whitening caused by reduced water resistance and deterioration of appearance, and can provide an epoxy resin composition with excellent surface appearance such as transparency, drying properties (easy drying), adhesion to a substrate, and water resistance.

[0008] However, epoxy resin curing agents that are modified products of polyamines generally have high viscosities, and further improvements in the water resistance of the resulting coating films have been desired.

[0009] Here, Patent Document 3 discloses a latent curing agent, which is mixed into an amine to become a curing agent and polymerizes and cures in an adhesive, and is a reaction product of a polyamine having two or more primary amino groups and furfural. However, the reaction product is an imine (aldimine), which is different from an amino compound. In addition, it is recorded that the amine produced by the hydrolysis of the aldimine in the latent curing agent, i.e., the aforementioned polyamine, acts as a curing agent, rather than the reaction product of the modified polyamine itself acting as an epoxy resin curing agent.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Japanese Patent Application Laid-Open No. 11-35661

[0013] Patent Document 2: Japanese Patent Application Publication No. 2007-186693

[0014] Patent Document 3: Japanese Patent Application Laid-Open No. 10-139849 Summary of the invention

[0015] Problem that the invention aims to solve

[0016] The present invention aims to provide an amino compound having low viscosity and capable of forming a coating film having excellent water resistance when used as an epoxy resin curing agent, a method for producing the same, an epoxy resin curing agent containing the amino compound, an epoxy resin composition and a cured product thereof.

[0017] Solutions for solving problems

[0018] The present inventors have found that an amino compound having a predetermined structure, which is a modified product of a predetermined aliphatic diamine, can solve the above-mentioned problems.

[0019] That is, the present invention relates to the following contents.

[0020] [1] An amino compound represented by the following general formula (1).

[0021] R 1 -NH-X-NH-R 2 (1)

[0022] (Where R 1 and R 2 Each independently is a hydrogen atom or a monovalent group represented by the following general formula (2), R 1 and R 2 At least one of them is a monovalent group represented by the following general formula (2). X is -CH 2 -A-CH 2 -(A is a cyclohexylene)-(CH 2 )n -、-(CH 2 CH 2 NH) m -CH 2 CH 2 -, or a divalent group represented by the following general formula (3) or (4). n is 2 to 6, and m is 1 or 2.

[0023]

[0024] (where the dashed line indicates the presence or absence of a π bond, R 3 ~R 5 Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group. * represents a connecting bond. )

[0025]

[0026] (Wherein, * represents a connecting bond.)

[0027] [2] The amino compound according to [1] above, wherein X in the general formula (1) is -CH 2 -A-CH 2 -(A is cyclohexylene) is a divalent group represented by.

[0028] [3] An epoxy resin curing agent comprising the amino compound described in [1] or [2] above.

[0029] [4] An epoxy resin composition comprising an epoxy resin and the epoxy resin curing agent according to [3] above.

[0030] [5] A cured product, which is a cured product of the epoxy resin composition described in [4] above.

[0031] [6] The method for producing an amino compound according to [1] or [2], which comprises the following steps (1) and (2) in order.

[0032] Step (1): a step of reacting a diamine represented by the following general formula (5) with an aldehyde compound represented by the following general formula (6) to obtain an imine.

[0033] Step (2): a step of reducing the imine obtained in the above step (1).

[0034] NH 2 -X-NH 2 (5)

[0035] (Wherein, X is the same as above.)

[0036]

[0037] (Where R 3 ~R 5 Same as above.)

[0038] [7] The method for producing an amino compound according to [6] above, wherein in the step (1), 0.8 to 2.0 mol of the aldehyde compound represented by the general formula (6) is reacted with 1.0 mol of the diamine represented by the general formula (5).

[0039] Effects of the Invention

[0040] According to the present invention, there are provided an amino compound having low viscosity and capable of forming a coating film having excellent water resistance when used as an epoxy resin curing agent, a method for producing the same, an epoxy resin curing agent containing the amino compound, an epoxy resin composition, and a cured product thereof. DETAILED DESCRIPTION

[0041] [Amino compounds]

[0042] The amino compound of the present invention is an amino compound represented by the following general formula (1).

[0043] R 1 -NH-X-NH-R 2 (1)

[0044] (Where R 1 and R 2 Each independently is a hydrogen atom or a monovalent group represented by the following general formula (2), R 1 and R 2 At least one of them is a monovalent group represented by the following general formula (2). X is -CH 2 -A-CH 2 -(A is a cyclohexylene)-(CH 2 ) n -、-(CH 2 CH 2 NH) m -CH 2 CH 2 -, or a divalent group represented by the following general formula (3) or (4). n is 2 to 6, and m is 1 or 2.

[0045]

[0046] (where the dashed line indicates the presence or absence of a π bond, R 3 ~R 5 Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group. * represents a connecting bond. )

[0047]

[0048] (Wherein, * represents a connecting bond.)

[0049] The epoxy resin curing agent containing the amino compound of the present invention has low viscosity, and further, when an epoxy resin composition containing the epoxy resin curing agent is used, a coating film having excellent water resistance can be formed.

[0050] The reason why the amino compound of the present invention can obtain the above-mentioned effects is not clear, but is considered to be as follows.

[0051] The amino compound of the present invention is obtained, for example, by reducing a specified aliphatic diamine and a reactant (imine) of furfural or its derivatives. From this point of view, it can be said that it is a modified product of a specified aliphatic diamine. It is believed that in the above-mentioned manufacturing method, by using a specified aliphatic diamine as a reaction raw material of the amino compound, and then introducing an aromatic substituent such as a furan ring as a substituent of the amino group in the aliphatic diamine, the hydrophobicity is improved, and the water resistance of the coating film is improved. In addition, it is believed that if the diamine is usually modified with an epoxy compound, the viscosity will be high, but by modifying the diamine with furfural or its derivatives, the viscosity increase can be suppressed. It is believed that the amino compound of the present invention does not need to add a non-reactive diluent to make it low in viscosity, so in the coating of the epoxy resin composition in which the amino compound is used as an epoxy resin curing agent, the reduction of water resistance caused by containing a non-reactive diluent can also be suppressed.

[0052] In the above general formula (1), R 1 and R 2 Each independently is a hydrogen atom or a monovalent group represented by the following general formula (2), R 1 and R 2 At least one of them is a monovalent group represented by the following general formula (2).

[0053]

[0054] (where the dashed line indicates the presence or absence of a π bond, R 3 ~R 5 Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group. * represents a connecting bond. )

[0055] In the general formula (2), the dotted line indicates the presence or absence of a π bond. The dotted line preferably indicates the presence of a π bond, but may also include a case where a portion of the π bond is reduced and the π bond does not exist.

[0056] In the above general formula (2), R 3 ~R 5 The alkyl group in the group is preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.

[0057] From the viewpoint of improving low viscosity, rapid curing when used as an epoxy resin curing agent, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, R 3 ~R 5 Preferably, it is a hydrogen atom, a methyl group or a hydroxymethyl group, more preferably a hydrogen atom or a methyl group, and further preferably, R 3 ~R 5 All hydrogen atoms, or R 3 is methyl and R 4 and R 5 is a hydrogen atom, and more preferably R 3 ~R 5 All are hydrogen atoms.

[0058] In the above general formula (1), X is -CH 2 -A-CH 2 -(A is a cyclohexylene)-(CH 2 ) n -、-(CH 2 CH 2 NH) m -CH 2 CH 2 -, or a divalent group represented by the following general formula (3) or (4): n is 2 to 6, and m is 1 or 2.

[0059]

[0060] (Wherein, * represents a connecting bond.)

[0061] From the viewpoint of improving low viscosity, rapid curing property when used as an epoxy resin curing agent, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, X in the general formula (1) is preferably -CH 2 -A-CH 2 -(A is cyclohexylene) or a divalent group represented by the above general formula (3) or (4), more preferably -CH 2 -A-CH 2 -(A is cyclohexylene) or a divalent group represented by the general formula (3), more preferably -CH 2 -A-CH 2 -(A is cyclohexylene) is a divalent group represented by.

[0062] For -CH 2 -A-CH 2-A is specifically 1,2-cyclohexylene, 1,3-cyclohexylene or 1,4-cyclohexylene. From the viewpoint of improving low viscosity, rapid curing when used as an epoxy resin curing agent, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, preferably 1,3-cyclohexylene or 1,4-cyclohexylene, more preferably 1,3-cyclohexylene.

[0063] [Amino composition]

[0064] The amino compound of the present invention may be in the form of an amino composition comprising two or more amino compounds. For example, the amino composition may comprise: in the above general formula (1), R 1 and R 2 An amino compound in which one of the two is a hydrogen atom and the other is a monovalent group represented by the general formula (2) (hereinafter, this compound is also referred to as "1-adduct"), and R 1 and R 2 The amino compound is a mixture of amino compounds (hereinafter referred to as "2-adduct") which are all monovalent groups represented by the general formula (2). However, from the viewpoint of improving low viscosity, rapid curing when used as an epoxy resin curing agent, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, the amino composition preferably comprises: R in the general formula (1) 1 and R 2 An amino compound (1 adduct) in which one of the amino groups is a hydrogen atom and the other is a monovalent group represented by the above general formula (2).

[0065] The amino composition comprises R 1 and R 2 One of them is a hydrogen atom and the other is an amino compound (1 adduct) represented by the above general formula (2), and contains R 1 and R 2 When both are amino compounds (2 adducts) having a monovalent group represented by the general formula (2), the molar ratio of the 1 adduct to the 2 adduct in the amino composition (1 adduct / 2 adduct) is preferably 1 / 99 to 99.9 / 0.1, more preferably 5 / 95 to 99 / 1, further preferably 10 / 90 to 99 / 1, further preferably 20 / 80 to 99 / 1, further preferably 30 / 70 to 99 / 1, further preferably 40 / 60 to 99 / 1, further preferably 50 / 50 to 99 / 1, from the viewpoint of improving low viscosity, rapid curing property when used as an epoxy resin curing agent, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition.

[0066] The above molar ratio can be specifically obtained by the method described in the Examples.

[0067] The amino composition may contain, in addition to the amino compound represented by the general formula (1), a diamine represented by the general formula (5) described below as a by-product or an unreacted raw material. However, from the viewpoint of improving low viscosity, rapid curing when used as an epoxy resin curing agent, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, the content of the amino compound represented by the general formula (1) in the amino composition is preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, and is 100% by mass or less.

[0068] In addition, from the viewpoint of improving the hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, the content of the diamine represented by the above-mentioned general formula (5) as an unreacted raw material in the amino composition is preferably 5 mass % or less, more preferably 2 mass % or less, and further preferably 1 mass % or less.

[0069] The content of the amino compound in the amino composition and the content of the diamine represented by the general formula (5) as an unreacted raw material can be measured by gas chromatography (GC) analysis.

[0070] From the viewpoint of obtaining a low-viscosity epoxy resin curing agent, the viscosity of the aforementioned amino compound or amino composition at 25°C is preferably 500 mPa·s or less, more preferably 300 mPa·s or less, further preferably 200 mPa·s or less, further preferably 150 mPa·s or less, further preferably 100 mPa·s or less, further preferably 90 mPa·s or less, and typically 10 mPa·s or more.

[0071] The viscosity of the amino compound or the amino composition at 25° C. can be measured using an E-type viscometer, specifically by the method described in Examples.

[0072] [Method for producing amino compound and amino composition]

[0073] The method for producing the amino compound and the amino composition of the present invention (hereinafter also referred to as "the production method of the present invention") preferably comprises the following steps (1) and (2) in this order.

[0074] Step (1): a step of reacting a diamine represented by the following general formula (5) with an aldehyde compound represented by the following general formula (6) to obtain an imine.

[0075] Step (2): a step of reducing the imine obtained in the above step (1).

[0076] NH 2 -X-NH 2 (5)

[0077] (Wherein, X is the same as above.)

[0078]

[0079] (Where R 3 ~R 5 Same as above.)

[0080] <Process (1)>

[0081] In the step (1), the diamine represented by the general formula (5) and the aldehyde compound represented by the general formula (6) are reacted to obtain an imine.

[0082] In the above general formula (5), X is -CH 2 -A-CH 2 -(A is a cyclohexylene)-(CH 2 ) n -、-(CH 2 CH 2 NH) m -CH 2 CH 2 -, or a divalent group represented by the following general formula (3) or (4). n is 2 to 6, and m is 1 or 2.

[0083]

[0084] (Wherein, * represents a connecting bond.)

[0085] From the viewpoint of improving low viscosity, rapid curing when used as an epoxy resin curing agent, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, X in the general formula (5) is preferably -CH 2 -A-CH 2 -(A is cyclohexylene) or a divalent group represented by the above general formula (3) or (4), more preferably -CH 2 -A-CH 2 -(A is cyclohexylene) or a divalent group represented by the general formula (3), more preferably -CH 2 -A-CH 2 -(A is cyclohexylene) is a divalent group represented by.

[0086] For -CH 2 -A-CH 2-A is specifically 1,2-cyclohexylene, 1,3-cyclohexylene or 1,4-cyclohexylene. From the viewpoint of improving low viscosity, rapid curing when used as an epoxy resin curing agent, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, preferably 1,3-cyclohexylene or 1,4-cyclohexylene, more preferably 1,3-cyclohexylene.

[0087] Specific examples of the diamine represented by the general formula (5) are at least one selected from the group consisting of bis(aminomethyl)cyclohexane, ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine (IPDA), and norbornanediamine. Among these, from the viewpoint of improving low viscosity, rapid curing property when used as an epoxy resin curing agent, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, at least one selected from the group consisting of bis(aminomethyl)cyclohexane, isophoronediamine (IPDA) and norbornanediamine is preferred, at least one selected from the group consisting of bis(aminomethyl)cyclohexane and isophoronediamine is more preferred, bis(aminomethyl)cyclohexane is further preferred, at least one selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane and 1,4-bis(aminomethyl)cyclohexane is further preferred, and 1,3-bis(aminomethyl)cyclohexane is further preferred.

[0088] In the above general formula (6), R 3 ~R 5 Each R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group. 3 ~R 5 The alkyl group in the group is preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.

[0089] From the viewpoint of improving the low viscosity of the amino compound and amino composition obtained, the rapid curing property when used as an epoxy resin curing agent, the hardness, appearance and water resistance of the coating film of the epoxy resin composition obtained, R 3 ~R 5 Preferably it is a hydrogen atom, a methyl group or a hydroxymethyl group, more preferably a hydrogen atom or a methyl group, and further preferably R 3 ~R 5 All hydrogen atoms, or R 3 is methyl and R 4 and R 5 is a hydrogen atom, and more preferably R 3 ~R 5 All are hydrogen atoms.

[0090] Specific examples of the aldehyde compound represented by the aforementioned general formula (6) include furfural, 3-methylfurfural, 4-methylfurfural, 5-methylfurfural, 3-hydroxymethylfurfural, 4-hydroxymethylfurfural, 5-hydroxymethylfurfural, 4,5-dimethylfurfural, 3-ethylfurfural, 4-ethylfurfural, 5-ethylfurfural, 3-propylfurfural, 4-propylfurfural, 5-propylfurfural, 3-butylfurfural, 4-butylfurfural, 5-butylfurfural, etc. Among them, one kind or two or more kinds can be used.

[0091] Among the above, from the viewpoint of improving the low viscosity of the obtained amino compound and amino composition, the rapid curing property when used as an epoxy resin curing agent, the hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, the aldehyde compound represented by the general formula (6) is preferably at least one selected from the group consisting of furfural, 3-methylfurfural, 4-methylfurfural, 5-methylfurfural, 3-hydroxymethylfurfural, 4-hydroxymethylfurfural, 5-hydroxymethylfurfural and 4,5-dimethylfurfural, more preferably at least one selected from the group consisting of furfural and 5-methylfurfural, and even more preferably furfural.

[0092] In step (1), from the viewpoint of obtaining the amino compound represented by the general formula (1) in high yield, it is preferred to react 0.8 to 2.0 mol of the aldehyde compound represented by the general formula (6) with respect to 1.0 mol of the diamine represented by the general formula (5). 1 and R 2 From the perspective of an amino compound in which one of the aldehyde compounds is a hydrogen atom and the other is a monovalent group represented by the general formula (2), the amount of the aldehyde compound represented by the general formula (6) to be reacted is more preferably 1.0 to 2.0 mol, further preferably 1.0 to 1.8 mol, further preferably 1.0 to 1.5 mol, further preferably 1.0 to 1.3 mol, relative to 1.0 mol of the diamine represented by the general formula (5).

[0093] The reaction of the diamine represented by the general formula (5) and the aldehyde compound represented by the general formula (6) is preferably carried out under heating and stirring conditions. From the viewpoint of improving the reaction efficiency and inhibiting the thermal degradation of the diamine and the aldehyde compound as raw materials, the reaction temperature is preferably in the range of 40 to 120° C., more preferably in the range of 50 to 95° C. The reaction time can be appropriately selected and is usually in the range of 0.5 to 6 hours.

[0094] The above reaction may be carried out in a reaction solvent or in the absence of a solvent.

[0095] The above reaction in step (1) can produce an imine which is a reaction product of the diamine represented by the general formula (5) and the aldehyde compound represented by the general formula (6). The reaction product obtained in step (1) may be purified or directly supplied to step (2) without purification.

[0096] <Process (2)>

[0097] In step (2), the imine obtained in step (1) is reduced and converted into an amine. The reduction of the imine is preferably carried out by hydrogenation (hydrogenation) in the presence of a catalyst under heating and pressure conditions.

[0098] As the catalyst used in step (2), known hydrogenation catalysts can be listed, for example, supported heterogeneous hydrogenation catalysts in which metals such as Ni, Pt, Pd, and Ru are supported on carbon, silica, alumina, diatomaceous earth, etc.; so-called Ziegler-type hydrogenation catalysts using organic acid salts of Ni, Co, Fe, Cr, etc. or transition metal salts such as acetylacetonate and reducing agents such as organic aluminum; homogeneous hydrogenation catalysts such as so-called organic metal complexes such as organic metal compounds of Ti, Ru, Rh, and Zr, etc.

[0099] From the viewpoint of improving reaction efficiency and suppressing side reactions, the temperature during the hydrogenation reaction is preferably 0°C or higher, more preferably 10°C or higher, further preferably 20°C or higher, and is preferably 200°C or lower, more preferably 150°C or lower, further preferably 100°C or lower.

[0100] From the viewpoint of improving reaction efficiency and suppressing side reactions, the pressure during the hydrogenation reaction is preferably 0.01 MPaG or more, more preferably 0.1 MPaG or more, further preferably 0.3 MPaG or more, and is preferably 10 MPaG or less, more preferably 3 MPaG or less.

[0101] The reaction time is not particularly limited, but is preferably 3 minutes or longer, more preferably 10 minutes or longer, and even more preferably 30 minutes or longer, and is preferably 24 hours or shorter, more preferably 12 hours or shorter, and even more preferably 8 hours or shorter.

[0102] The hydrogenation reaction may also be carried out in the presence of a solvent. The solvent is not particularly limited as long as it does not hinder the hydrogenation reaction, and examples thereof include aliphatic hydrocarbons such as pentane, hexane, isopentane, heptane, octane, isooctane, etc.; alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, etc.; and hydrocarbon solvents such as aromatic hydrocarbons such as toluene, ethylbenzene, and xylene. These may be used alone or in combination of two or more.

[0103] After the hydrogenation reaction, the catalyst is removed from the obtained reaction solution, and distillation purification or the like is performed as necessary to obtain the amino compound of the present invention or the above-mentioned amino composition.

[0104] It should be noted that the method for producing the amino compound and the amino composition is not limited to the above method. For example, the amino compound and the amino composition can also be produced by the following methods: a method of subjecting the diamine represented by the general formula (5) to a deamination reaction with an amine represented by the general formula (7) in the presence of a catalyst; a method of subjecting the diamine represented by the general formula (5) to a reaction with an alcohol represented by the general formula (8) in the presence of a catalyst and under a hydrogen atmosphere; a method of subjecting the diamine represented by the general formula (5) to a reaction with a chloride represented by the general formula (9). In this case, the compounds represented by the general formulas (7) to (9) are preferably reacted in an amount of 1.0 to 2.0 moles, more preferably 1.0 to 1.8 moles, further preferably 1.0 to 1.5 moles, and further preferably 1.0 to 1.3 moles, relative to 1 mole of the diamine represented by the general formula (5).

[0105]

[0106] (In formulas (7) to (9), R 3 ~R 5 Same as above.)

[0107] [Epoxy resin curing agent]

[0108] The epoxy resin curing agent of the present invention contains the amino compound of the present invention or the aforementioned amino composition. The epoxy resin curing agent has low viscosity and, when used in an epoxy resin composition, can form a coating film having excellent water resistance.

[0109] From the viewpoint of improving low viscosity, rapid curing properties, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, the content of the amino compound represented by the above-mentioned general formula (1) in the epoxy resin curing agent is preferably 30% by mass or more, more preferably 50% by mass or more, further preferably 60% by mass or more, further preferably 70% by mass or more, further preferably 80% by mass or more, further preferably 90% by mass or more, and is 100% by mass or less.

[0110] From the viewpoint of improving low viscosity, rapid curing, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, the content of the above-mentioned amino composition in the epoxy resin curing agent is preferably 30% by mass or more, more preferably 50% by mass or more, further preferably 60% by mass or more, further preferably 70% by mass or more, further preferably 80% by mass or more, further preferably 90% by mass or more, and is 100% by mass or less.

[0111] The epoxy resin curing agent of the present invention may contain other curing agent components in addition to the amino compound of the present invention or the aforementioned amino composition. The curing agent component in this specification refers to a component contained in the epoxy resin curing agent and having two or more active hydrogens that can react with the epoxy groups in the epoxy resin.

[0112] Examples of the other curing agent component include amine curing agents, phenol curing agents, and acid anhydride curing agents. From the viewpoint of rapid curing properties, amine curing agents are preferred.

[0113] Examples of the amine curing agent include polyamine compounds other than the amino compound or amino composition of the present invention or modified products thereof. The polyamine compound is not particularly limited as long as it has at least two amino groups in the molecule.

[0114] Examples of the polyamine compound or its modified product include: chain aliphatic polyamine compounds such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexamethylenediamine, 2-methylpentamethylenediamine, and trimethylhexamethylenediamine; 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, menthanediamine, and the like; diamine), isophorone diamine, norbornane diamine, tricyclodecane diamine, adamantane diamine, diaminocyclohexane, 1,4-diamino-2-methylcyclohexane, 1,4-diamino-3,6-diethylcyclohexane, diaminodiethylmethylcyclohexane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylmethane and other polyamine compounds having an alicyclic structure; o-phenylenediamine, m-phenylenediamine and p-phenylenediamine, phenylenediamine, diaminodiphenylmethane, diamino Polyamine compounds having an aromatic ring such as 1,2-diphenylsulfone, etc.; polyamine compounds having a heterocyclic structure such as N-aminomethylpiperazine, N-aminoethylpiperazine, etc.; polyether polyamine compounds; reaction products obtained by reacting the above polyamine compounds with epoxy compounds having at least one epoxy group, unsaturated hydrocarbon compounds, carboxylic acids or their derivatives; Mannich reactants obtained by reacting the above polyamine compounds with phenol compounds and aldehyde compounds; ketimines obtained by reacting the above polyamine compounds with ketone compounds; etc. These may be used alone or in combination of two or more.

[0115] When other curing agent components are used, the content of the other curing agent components in the epoxy resin curing agent is preferably 1% by mass or more, more preferably 5% by mass or more. The upper limit of the content is within the range that does not impair the effect of the present invention, preferably 70% by mass or less, more preferably 50% by mass or less, further preferably 40% by mass or less, further preferably 30% by mass or less, and further preferably 20% by mass or less.

[0116] The epoxy resin curing agent of the present invention may further contain a known curing accelerator, a non-reactive diluent, and the like.

[0117] Examples of the curing accelerator include phenol compounds, organic acids, organic acid salts, tertiary amines, quaternary ammonium salts, imidazoles, organic phosphorus compounds, quaternary phosphonium salts, diazabicycloolefins, organic metal salt compounds, boron compounds, and metal halides.

[0118] Examples of the non-reactive diluent include benzyl alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, and aromatic hydrocarbon formaldehyde resins. Among these, one kind or two or more kinds may be used.

[0119] However, from the viewpoint of improving the water resistance of the coating film of the obtained epoxy resin composition, the epoxy resin curing agent of the present invention preferably has a small content of the non-reactive diluent. The content of the non-reactive diluent in the epoxy resin curing agent is preferably 20% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, further preferably 1% by mass or less, and further preferably 0% by mass.

[0120] From the viewpoint of improving low viscosity, fast curing, hardness, appearance and water resistance of the coating film of the obtained epoxy resin composition, the active hydrogen equivalent of the epoxy resin curing agent is preferably 80 or more, and from the viewpoint of improving curability, it is preferably 150 or less, and more preferably 120 or less. The active hydrogen equivalent (hereinafter also referred to as "AHEW") in this specification refers to the mass of active hydrogen derived from amino groups of the epoxy resin curing agent per 1 mol. The AHEW of the curing agent can be obtained by the amine value.

[0121] [Epoxy resin composition]

[0122] The epoxy resin composition of the present invention contains an epoxy resin and the epoxy resin curing agent. The epoxy resin composition has a high curing speed and the resulting coating film has excellent hardness and water resistance.

[0123] <Epoxy resin>

[0124] The epoxy resin as the main agent of the epoxy resin composition may be any of saturated or unsaturated aliphatic compounds, alicyclic compounds, aromatic compounds, and heterocyclic compounds. From the viewpoint of improving the curing speed and forming a coating film with high hardness, appearance, and water resistance, an epoxy resin containing an aromatic ring or alicyclic structure in the molecule is preferred.

[0125] Specific examples of the epoxy resin include at least one selected from epoxy resins having glycidylamino groups derived from m-phenylenediamine, epoxy resins having glycidylamino groups derived from p-phenylenediamine, epoxy resins having glycidylamino groups derived from 1,3-bis(aminomethyl)cyclohexane, epoxy resins having glycidylamino groups derived from 1,4-bis(aminomethyl)cyclohexane, epoxy resins having glycidylamino groups derived from diaminodiphenylmethane, epoxy resins having glycidylamino groups and / or glycidyloxy groups derived from p-aminophenol, epoxy resins having glycidyloxy groups derived from bisphenol A, epoxy resins having glycidyloxy groups derived from bisphenol F, epoxy resins having glycidyloxy groups derived from phenol novolac, and epoxy resins having glycidyloxy groups derived from resorcinol. Two or more of the above epoxy resins may be used in combination.

[0126] Among the above, from the viewpoint of improving the curing speed and forming a coating film having excellent hardness, appearance and water resistance, the epoxy resin preferably contains as a main component at least one selected from the group consisting of an epoxy resin having a glycidyl amino group derived from m-xylylenediamine, an epoxy resin having a glycidyl amino group derived from p-xylylenediamine, an epoxy resin having a glycidyl ether group derived from bisphenol A and an epoxy resin having a glycidyl ether group derived from bisphenol F. From the viewpoint of improving the curing speed, forming a coating film having excellent hardness, appearance and water resistance, and from the viewpoint of availability and economic efficiency, the epoxy resin containing as a main component an epoxy resin having a glycidyl ether group derived from bisphenol A is more preferred.

[0127] It should be noted that the “main component” referred to herein may contain other components within the scope of the present invention, and is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and even more preferably 90 to 100% by mass of the whole.

[0128] From the viewpoint of improving operability, the epoxy resin as the main agent may also contain a reactive diluent other than the above epoxy resin. As the reactive diluent, low molecular weight compounds having at least one epoxy group may be cited, for example, aromatic monoglycidyl ethers such as phenyl glycidyl ether and cresyl glycidyl ether; alkyl monoglycidyl ethers such as butyl glycidyl ether, hexyl glycidyl ether, octyl glycidyl ether, decyl glycidyl ether, lauryl glycidyl ether, tetradecyl glycidyl ether; diglycidyl ethers of aliphatic diols such as 1,3-propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether.

[0129] The above-mentioned reactive diluents may be used alone or in combination of two or more.

[0130] Regarding the content ratio of the epoxy resin and the epoxy resin curing agent in the epoxy resin composition of the present invention, the ratio of the number of active hydrogen atoms derived from the amino groups in the epoxy resin curing agent to the number of epoxy groups in the epoxy resin (the number of active hydrogen atoms derived from the amino groups in the epoxy resin curing agent / the 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.

[0131] The content of the epoxy resin and the epoxy resin curing agent in the epoxy resin composition is not limited as long as the ratio of the number of active hydrogens derived from the amino groups in the epoxy resin curing agent to the number of epoxy groups in the epoxy resin is preferably within the above-mentioned range, but is preferably within the following range from the viewpoint of improving the curing speed and forming a coating film having excellent hardness, appearance and water resistance.

[0132] The content of the epoxy resin in the epoxy resin composition is preferably 40% by mass or more, more preferably 50% by mass or more, further preferably 60% by mass or more, and is preferably 80% by mass or less, more preferably 75% by mass or less.

[0133] The content of the epoxy resin curing agent in the epoxy resin composition is preferably 20% by mass or more, more preferably 25% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, and further preferably 40% by mass or less.

[0134] The content of the epoxy resin curing agent in the epoxy resin composition is preferably 20 to 70 parts by mass, more preferably 30 to 70 parts by mass, further preferably 40 to 65 parts by mass, and further preferably 40 to 60 parts by mass, based on 100 parts by mass of the epoxy resin as the main agent.

[0135] From the viewpoint of improving low viscosity, rapid curing, hardness, appearance and water resistance of the coating film, the total content of the epoxy resin and the epoxy resin curing agent in the epoxy resin composition is preferably 40% by mass or more, more preferably 50% by mass or more, further preferably 60% by mass or more, further preferably 70% by mass or more, further preferably 80% by mass or more, further preferably 90% by mass or more, and is 100% by mass or less.

[0136] The epoxy resin composition of the present invention may further contain modifying components such as fillers and plasticizers; flow regulating components such as thixotropic agents; and other components such as pigments, leveling agents, tackifiers, and elastomer microparticles, depending on the intended use.

[0137] The epoxy resin composition of the present invention may also contain the aforementioned non-reactive diluent and a solvent other than the non-reactive diluent (water and a volatile solvent), and the content thereof is preferably 5% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less in the epoxy resin composition.

[0138] <Method for producing epoxy resin composition>

[0139] The method for producing the epoxy resin composition of the present invention is not particularly limited, and the epoxy resin, epoxy resin curing agent, and other components as required can be mixed and produced using a known method and apparatus. The mixing order of the components contained in the epoxy resin composition is also not particularly limited, and the epoxy resin curing agent can be mixed with the epoxy resin after the epoxy resin curing agent is prepared, or the components constituting the epoxy resin curing agent, other components, and the epoxy resin can be mixed simultaneously to produce the epoxy resin composition.

[0140] [cured material]

[0141] The cured product of the epoxy resin composition of the present invention (hereinafter also referred to as "cured product of the present invention") is obtained by curing the aforementioned epoxy resin composition by a known method. The curing conditions of the epoxy resin composition are appropriately selected according to the application and form, and are not particularly limited.

[0142] The form of the cured product of the present invention is not particularly limited and can be selected according to the intended use. The cured product of the epoxy resin composition is preferably a film-shaped cured product from the viewpoint of forming a coating film having excellent hardness, appearance, and water resistance.

[0143] <Application>

[0144] The epoxy resin composition of the present invention can be preferably used in coating applications such as marine coatings, heavy-duty anticorrosive coatings, can coatings, pipe interior coatings, exterior coatings, and floor coatings, from the viewpoint of forming a coating film having excellent hardness, appearance, and water resistance.

[0145] Example

[0146] The present invention is described in detail below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In addition, the amino composition or the analysis and evaluation of the amino composition were performed by the following methods.

[0147] <Gas chromatography (GC) analysis>

[0148] The content ratio of each component in the amino composition was measured by GC analysis. The measurement conditions were as follows.

[0149] Device: "7890B GC" manufactured by Agilent Technologies Japan, Ltd.

[0150] Chromatographic column: Agilent Technologies Japan, Ltd. "CP-Sil 8CB for Amines" (length 30m, film thickness 0.25μm, inner diameter 0.25mm)

[0151] Column temperature: 40℃10 minutes→20℃ / min heating→250℃10 minutes→20℃ / min heating→300℃10 minutes

[0152] Carrier gas: Helium

[0153] Carrier gas flow rate: 2.2553mL / min

[0154] Inlet pressure: 22.474 psi (constant pressure mode)

[0155] Detector: FID

[0156] Inlet temperature: 250℃

[0157] Detector temperature: 310°C

[0158] <Composition analysis of amino composition (molar ratio of 1-adduct and 2-adduct)>

[0159] The total amine value and the secondary / tertiary amine value were determined from the results of the molar ratio of the 1-adduct to the 2-adduct in the amino composition (1-adduct / 2-adduct) using a potentiometric automatic 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., Ltd.), and the secondary / tertiary amine value was measured using 0.1 mol / L hydrochloric acid (2-propanol).

[0160] < 1 H-NMR analysis>

[0161] The structures of the components contained in the amino composition obtained were identified by 1 The measurement conditions were as follows.

[0162] Nuclear magnetic resonance spectrometer: AVANCEIII-500 manufactured by Bruker BioSpin

[0163] Probe; Double resonance multi-nuclide probe (BBFO Plus Smart probe)

[0164] Deuterated solvent; deuterated chloroform

[0165] Determination of nuclear; 1H

[0166] Measuring temperature; room temperature

[0167] <Viscosity measurement>

[0168] The viscosity of the amino composition (curing agent) at 25° C. was measured using an E-type viscometer “TVE-35H Viscometer Cone Plate Type” manufactured by Toki Sangyo Co., Ltd.

[0169] <Determination of active hydrogen equivalent weight (AHEW)>

[0170] The AHEW of the amino composition (curing agent) was determined by using a potentiometric automatic titrator "AT-710S" manufactured by KYOTO ELECTRONICS MANUFACTURING CO., LTD. to determine the total amine value and the secondary / tertiary amine value, and the AHEW was calculated from the results. The total amine value was measured using a 0.1 mol / L perchloric acid-acetic acid solution (manufactured by Kanto Chemical Co., Ltd.), and the secondary / tertiary amine value was measured using 0.1 mol / L hydrochloric acid (2-propanol).

[0171] <Dry to touch>

[0172] A zinc phosphate treated steel plate (manufactured by PALTEK CORPORATION; SPCC-SDPB-N144 0.8×70×150 mm) was used as a substrate. At 23°C and 50% RH, the epoxy resin composition of each example was applied to the substrate using an applicator to form a coating film (the coating film thickness immediately after coating: 200 μm). The coating film was stored at 23°C and 50% RH, and was evaluated by finger touch after 1 day and 7 days according to the following criteria. The results are shown in Table 1.

[0173] Ex: Excellent (no stickiness of the coating and no fingerprint residue when pressing the thumb with a force of about 50N)

[0174] G: Good (When the thumb is pressed with a force of about 50N, the coating does not feel sticky, but fingerprints remain after the touch)

[0175] F: Yes (the coating becomes sticky when the thumb is pressed with a force of about 50N)

[0176] P: Poor (uncured)

[0177] <Pencil hardness>

[0178] The epoxy resin composition was applied to a substrate (zinc phosphate treated steel plate) in the same manner as above to form a coating film (thickness immediately after coating: 200 μm). The coating film was stored at 23° C. and 50% RH, and the pencil hardness was measured after 1 day and 7 days in accordance with JIS K5600-5-4:1999. The results are shown in Table 1.

[0179] <Water spot test>

[0180] The epoxy resin composition was applied to a substrate (zinc phosphate treated steel plate) in the same manner as described above to form a coating (thickness just after coating: 200 μm). The coating was stored at 23°C and 50% RH, and after 1 day and 7 days, 2 to 3 drops of pure water were added to the coating surface with a dropper, and the position was covered with a 50 mL screw-threaded tube bottle. After 24 hours, the water was wiped off, the appearance was visually observed, and the evaluation was performed based on the following criteria. The results are shown in Table 1.

[0181] Ex: No change at all

[0182] G: There are some changes, but it is OK to use

[0183] F: Slightly white

[0184] P: Significant whitening

[0185] <Appearance (transparency / gloss)>

[0186] The epoxy resin composition of each example was applied to a substrate (zinc phosphate treated steel plate) using an applicator in the same manner as above to form a coating film (coating film thickness immediately after coating: 200 μm). The coating film was stored at 23° C. and 50% RH, and the appearance was visually observed after 1 day. The transparency and gloss were evaluated based on the following criteria. The results are shown in Table 1.

[0187] (Transparency)

[0188] Ex: No turbidity

[0189] G: A little turbid, but no problem in use

[0190] F: Slightly cloudy

[0191] P: White turbidity

[0192] (luster)

[0193] Ex: Glossy

[0194] G: The glossiness is slightly reduced, but there is no problem in use

[0195] F: Less gloss

[0196] P: Matt

[0197] <RCI drying time (semi-drying)>

[0198] At 23°C and 50% RH, the epoxy resin composition of each example was applied to a glass plate (25×348×2.0 mm manufactured by Taiyu Kizai Co., Ltd.) using a 76 μm applicator to form a coating. The glass plate with the coating formed was installed in a coating drying time measuring instrument (manufactured by Taiyu Kizai Co., Ltd.), and the streak when the needle of the measuring instrument scraped across the surface of the coating was observed, and the time to reach semi-drying (the time when the needle mark emerged from the coating to the surface of the coating) was measured. The results are shown in Table 1. The shorter the time, the faster the curing speed.

[0199] Example 1

[0200] (Manufacturing of amino composition A)

[0201] [Process (1)]

[0202] In a 1-liter separable flask equipped with a stirring device, a thermometer, a nitrogen inlet tube, a dropping funnel, and a condenser, 42.7 g (0.3 mol) of 1,3-(bisaminomethyl)cyclohexane (Mitsubishi Gas Chemical Co., Ltd., 1,3-BAC) was added, and 28.8 g (0.3 mol) of furfural (Tokyo Chemical Industry Co., Ltd.) was added dropwise over 15 to 20 minutes while stirring under a nitrogen flow. After the addition was completed, the temperature was raised to 80°C and the reaction was carried out for 30 minutes. The reaction product was measured. 1 H-NMR and confirmed the aldehyde group derived from furfural 1 The peak of H disappeared, and the reaction was terminated. Thereafter, toluene was added to the reaction product, and the water in the system was removed by azeotropic dehydration to obtain imine as a reaction product of 1,3-BAC and furfural in a molar ratio of 1 / 1.

[0203] [Process (2)]

[0204] Into an autoclave (capacity 230 mL, material: SUS316L) equipped with a stirrer and a heater, 32.4 g of the imine obtained in step (1), 30 g of toluene, and 0.3 g of a 5% Pd / C catalyst (manufactured by NECHEMCAT CORPORATION; STD type) as a hydrogenation catalyst were added, and the gas phase was replaced with hydrogen. Thereafter, the temperature was raised while stirring, and after the liquid temperature reached 80°C in 1 hour, the pressure was increased to 1 MPaG with hydrogen. Thereafter, under the condition of a liquid temperature of 80°C, the reaction was continued for 1.5 hours while hydrogen was supplied at any time in a manner that the pressure was maintained at 1 MPaG. The obtained reaction liquid was filtered, and after removing the hydrogenation catalyst, it was completely concentrated under vacuum to obtain 32.0 g of an amino composition a which was a reduced product of the imine obtained in step (1). The remaining 1,3-BAC was distilled off from the obtained amino composition a by reduced pressure distillation to obtain 26.2 g of an amino composition A. Using the obtained amino composition A, GC analysis and 1 H-NMR analysis was performed to calculate the composition ratios listed in Table 1. In the GC analysis, a solution prepared by dissolving 0.1 g of amino composition A in 1 g of methanol was used as a measurement sample. The GC area ratios listed in Table 1 refer to the area percentages of the components detected by gas chromatography.

[0205] In the obtained amino composition A, the content of the amino compound represented by the general formula (1) was 100% (1 adduct: 74%, 2 adduct: 26%) in terms of GC area ratio, and the molar ratio of 1 adduct to 2 adduct (1 adduct / 2 adduct) was 74 / 26. In addition, the viscosity and AHEW of the amino composition A at 25°C are shown in Table 1.

[0206] The amino composition A was subjected to the above conditions 1 As a result of H-NMR analysis, it was found that the compound represented by the following structural formula (A1) was the main component of the 1-adduct of the amino compound represented by the general formula (1) in the amino composition A, and the compound represented by the following structural formula (A2) was the main component of the 2-adduct. In addition, the 1-adduct contained not only the compound represented by the following structural formula (A1) but also a trace amount of a compound in which a part or all of the unsaturated bonds of the furan ring in the compound were reduced, and the 2-adduct contained not only the compound represented by the following structural formula (A2) but also a trace amount of a compound in which a part or all of the unsaturated bonds of the furan ring in the compound were reduced.

[0207]

[0208] The compound represented by structural formula (A1) 1 H-NMR chemical shift: δ7.35ppm (dd, 1H, -OC H=), δ6.30ppm(m, 1H, -O-CH=C H -), δ6.16ppm(m, 1H, -O-CH=CH-C H =), δ3.76ppm(d, 2H, -NH-C H 2 -C 4 H 3 O), δ2.60~2.44ppm (m, 4H, -C 6 H 10 -C H 2 -NH-, -C 6 H 10 -C H 2 -NH 2 ), δ1.96~0.52ppm (m, 13H, -C 6 H 10 -、-C 6 H 10 -CH 2 -N H -、-C 6 H 10 -CH 2 -N H 2 )

[0209]

[0210] The compound represented by structural formula (A2) 1 H-NMR chemical shift: δ7.34ppm (dd, 2H, -OC H =), δ6.30ppm(m, 2H, -O-CH=C H -), δ6.15ppm(m, 2H, -O-CH=CH-C H =), δ3.75ppm(d, 4H, -NH-C H 2 -C 4 H 3 O), δ2.52~2.44ppm (m, 4H, -C 6 H 10 -C H 2 -NH-), δ1.96~0.52ppm (m, 12H, -C 6 H 10 -、-C 6 H 10 -CH 2 -N H -)

[0211] (Preparation and evaluation of epoxy resin composition)

[0212] As the epoxy resin as the main agent, a liquid epoxy resin having a glycidyl ether group derived from bisphenol A ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 186 g / equivalent) was used, and as the epoxy resin curing agent, the amino composition A was used.

[0213] 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 an epoxy resin composition. The ratio of the number of active hydrogens in the epoxy resin curing agent to the number of epoxy groups in the main epoxy resin (the number of active hydrogens in the epoxy resin curing agent / the number of epoxy groups in the main epoxy resin) was adjusted to 1 / 1.

[0214] Using the obtained epoxy resin composition, various evaluations were carried out by the above-mentioned methods. The results are shown in Table 1.

[0215] Example 2

[0216] (Manufacturing of amino composition B)

[0217] In step (1) of Example 1, the amino composition B was produced by the same method as in Example 1 except that the amount of 1,3-BAC added was changed to 35.6 g (0.25 mol) and the amount of furfural added was changed to 36.0 g (0.38 mol). In the obtained amino composition B, the content of the amino compound represented by the general formula (1) was 100% (1 adduct: 44%, 2 adduct: 56%) in terms of GC area ratio. In addition, the molar ratio of 1 adduct to 2 adduct in the amino composition B, the viscosity at 25°C and the AHEW are shown in Table 1.

[0218] (Preparation and evaluation of epoxy resin composition)

[0219] In Example 1, except that the amino composition B was used instead of the amino composition A, the epoxy resin composition was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0220] Example 3

[0221] (Production of Amino Composition C)

[0222] In step (1) of Example 1, the amino composition C was produced by the same method as in Example 1 except that the amount of 1,3-BAC charged was changed to 35.6 g (0.25 mol) and 27.5 g (0.25 mol) of 5-methylfurfural (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of furfural. In the obtained amino composition C, the content of the amino compound represented by the general formula (1) was 100% (1 adduct: 75%, 2 adduct: 25%) in terms of GC area ratio. In addition, the molar ratio of 1 adduct to 2 adduct in the amino composition C, the viscosity at 25°C and the AHEW are shown in Table 1.

[0223] (Preparation and evaluation of epoxy resin composition)

[0224] In Example 1, except that amino composition C was used instead of amino composition A, the epoxy resin composition was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0225] The amino composition C was subjected to the above conditions 1 As a result of H-NMR analysis, it was found that the monoadduct of the amino compound represented by the general formula (1) in the amino composition C was a compound represented by the following structural formula (C1), and the diadduct was a compound represented by the following structural formula (C2).

[0226]

[0227] The compound represented by the structural formula (C1) 1 H-NMR chemical shift: δ 6.02 ppm (m, 1H, -OC (CH 3 )=C H -), δ5.87ppm(m, 1H, -OC(CH 3 )=CH-C H =), δ3.70ppm(d, 2H, -NH-C H 2 -C 4 H 2 O-CH 3 ), δ2.59~2.43ppm (m, 4H, -C 6 H 10 -C H 2 -NH-, -C 6 H 10 -C H 2 -NH 2 )、δ2.27ppm(s、3H、-C H 3 ), δ1.85~0.53ppm (m, 13H, -C 6 H 10 -、-C 6 H10 -CH 2 -N H -、-C 6 H 10 -CH 2 -N H 2 )

[0228]

[0229] The compound represented by structural formula (C2) 1 H-NMR chemical shift: δ 6.02 ppm (m, 2H, -OC (CH 3 )=C H -), δ5.87ppm(m, 2H, -OC(CH 3 )=CH-C H =), δ3.69ppm(d, 4H, -NH-C H 2 -C 4 H 2 O-CH 3 ), δ2.52~2.43ppm (m, 4H, -C 6 H 10 -C H 2 -NH-), δ2.27ppm(s, 6H, -C H 3 ), δ1.85~0.53ppm (m, 12H, -C 6 H 10 -、-C 6 H 10 -CH 2 -N H -)

[0230] Example 4

[0231] (Manufacturing of amino composition E)

[0232] In step (1) of Example 2, an amino composition E was produced by the same method as in Example 2 except that 42.6 g (0.25 mol) of isophorone diamine was used instead of 1,3-BAC. In the obtained amino composition E, the content of the amino compound represented by the general formula (1) was 100% in terms of GC area ratio (1 adduct represented by the following structural formula (E1): 42%, 1 adduct represented by the following structural formula (E2): 10%, 2 adduct represented by the following structural formula (E3): 46%). The molar ratio of the 1 adduct ((E1) and (E2)) to the 2 adduct (E3) in the amino composition E, the viscosity at 25°C, and the AHEW are shown in Table 1.

[0233] (Preparation and evaluation of epoxy resin composition)

[0234] In Example 1, except that the amino composition E was used instead of the amino composition A, the epoxy resin composition was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0235] The amino composition E was subjected to the above conditions 1 As a result of H-NMR analysis, it was found that the 1-adduct of the amino compound represented by the general formula (1) in the amino composition E contained the compounds represented by the following structural formulas (E1) and (E2) as main components, and the 2-adduct contained the compound represented by the following structural formula (E3) as main component. In addition, the 1-adduct contained not only the compound represented by the following structural formula (E1) or (E2) but also a trace amount of a compound in which a part or all of the unsaturated bonds of the furan ring in the compound were reduced, and the 2-adduct contained not only the compound represented by the following structural formula (E3) but also a trace amount of a compound in which a part or all of the unsaturated bonds of the furan ring in the compound were reduced.

[0236]

[0237] The compound represented by the structural formula (E1) 1 H-NMR chemical shift: δ7.35ppm (dd, 1H, -OC H =), δ6.30ppm(m, 1H, -O-CH=C H -), δ6.15ppm(m, 1H, -O-CH=CH-C H =), δ3.75ppm(d, 2H, -NH-C H 2 -C(O)=), δ2.97~0.80ppm(m, 21H, -C 6 H 7 -、-C H 3 、-NH-C H 2 -C 6 H 7 -、-N H -、-N H 2 )

[0238]

[0239] The compound represented by the structural formula (E2) 1 H-NMR chemical shift: δ7.35ppm (dd, 1H, -OC H =), δ6.30ppm(m, 1H, -O-CH=C H -), δ6.15ppm(m, 1H, -O-CH=CH-C H =), δ3.81ppm(d, 2H, -NH-C H 2 -C(O)=), δ2.97~0.80ppm(m, 21H, -C 6 H 7 -、-C H 3 、-NH-C H 2 -C 6 H 7 -、-N H -、-N H 2 )

[0240]

[0241] The compound represented by structural formula (E3) 1 H-NMR chemical shift: δ7.35ppm (dd, 2H, -OC H =), δ6.30ppm(m, 2H, -O-CH=C H -), δ6.15ppm(m, 2H, -O-CH=CH-C H =), δ3.81ppm(d, 2H, -C 6 H 7 -NH-C H 2 -C(O)=), δ3.75ppm(d, 2H, -CH 2 -NH-C H 2 -C(O)=), δ2.97~0.80ppm(m, 20H, -C 6 H 7 -、-C H 3 、-NH-C H 2 -C 6 H 7 -、-N H -)

[0242] Comparative Example 1

[0243] (Manufacturing of Comparative Amino Composition D)

[0244] In a separable flask with an internal volume of 300 ml equipped with a stirring device, a thermometer, a nitrogen inlet tube, a dropping funnel and a condenser, 42.7 g of 1,3-BAC (manufactured by Mitsubishi Gas Chemical Co., Ltd.) was placed, and 22.3 g (the amount such that the number of active hydrogens in 1,3-BAC / the number of epoxy groups in the epoxy compound were 10 / 1) of a multifunctional epoxy resin derived from bisphenol A and having a glycidyl ether group ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 186 g / equivalent) as an epoxy compound was added dropwise over 1 hour while stirring. After the dropwise addition was completed, the temperature was raised to 80° C. and reacted for 2 hours to obtain a 1,3-BAC-jER828 reaction composition. Benzyl alcohol was added thereto in an amount of 40% by mass of the total amount to dilute it, and a comparative amino composition D as a solution having a concentration of 60% by mass of the reaction composition was obtained. The AHEW of the comparative amino composition D (including the total amount of benzyl alcohol) is 100. In addition, the viscosity of the comparative amino composition D (including the total amount of benzyl alcohol) at 25° C. is shown in Table 1.

[0245] (Preparation and evaluation of epoxy resin composition)

[0246] In Example 1, except that the comparative amino composition D was used instead of the amino composition A, the epoxy resin composition was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0247] [Table 1]

[0248]

[0249] As can be seen from Table 1, the epoxy resin curing agent containing the amino compound of the present invention has a low viscosity, and the coating film of the epoxy resin composition using the curing agent is excellent in water resistance.

[0250] Industrial Applicability

[0251] According to the present invention, there are provided an amino compound having low viscosity and capable of forming a coating film having excellent water resistance when used as an epoxy resin curing agent, a method for producing the same, an epoxy resin curing agent containing the amino compound, an epoxy resin composition, and a cured product thereof.

Claims

1. An amino compound represented by the following general formula (1): R 1 -NH-X-NH-R 2 (1) In the formula, R 1 and R 2 Each independently is a hydrogen atom or a monovalent group represented by the following general formula (2), R 1 and R 2 At least one of them is a monovalent group represented by the following general formula (2); X is a divalent group represented by -CH2-A-CH2-, -(CH2) n -、-(CH2CH2NH) m -CH2CH2-, or a divalent group represented by the following general formula (3) or (4), wherein A is a cyclohexylene group; n is 2 to 6, and m is 1 or 2; In the formula, the dotted line indicates the presence or absence of a π bond, and R 3 ~R 5 Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, and * represents a connecting bond; In the formula, * represents a connecting bond.

2. The amino compound according to claim 1, wherein X in the general formula (1) is a divalent group represented by -CH2-A-CH2-, wherein A is a cyclohexylene group.

3. An epoxy resin curing agent comprising the amino compound according to claim 1 or 2. 4 . An epoxy resin composition comprising an epoxy resin and the epoxy resin curing agent according to claim 3 . 5 . A cured product, which is a cured product of the epoxy resin composition according to claim 4 .

6. The method for producing an amino compound according to claim 1 or 2, comprising the following steps (1) and (2) in sequence: Step (1): a step of reacting a diamine represented by the following general formula (5) with an aldehyde compound represented by the following general formula (6) to obtain an imine Step (2): a step of reducing the imine obtained in the step (1) NH2-X-NH2(5) Wherein, X is the same as above; In the formula, R 3 ~R 5 Same as above.

7. The method for producing an amino compound according to claim 6, wherein In the step (1), 0.8 to 2.0 mol of the aldehyde compound represented by the general formula (6) is reacted with 1.0 mol of the diamine represented by the general formula (5).

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