Aromatic amine compounds, curing agents, and epoxy resin compositions

Abstract

This invention provides aromatic amine compounds that can improve the balance between weight reduction and high elastic modulus at high temperatures. [Solution] The compound is represented by formula (1). TIFF2026088679000019.tif63153 (R1 and R2 are independently hydrogen, an amino group, or an organic group, and at least one of them is an amino group or an organic group having an amino group; R3 and R4 are independently hydrocarbon groups which may have an ester bond or an ether bond; R31-R35 and R41-R45 are independently hydrogen, a hydrocarbon group, or an amino group, and at least one of R31-R35 or at least one of R41-R45 is an amino group.)

Description

Technical Field

[0001] The present invention relates to an aromatic amine compound, a curing agent, and an epoxy resin composition. More specifically, it relates to an aromatic amine compound, a curing agent using the aromatic amine compound, an epoxy resin composition containing the aromatic amine compound as a curing agent, a molded product comprising a cured product of the epoxy resin composition, and a transportation equipment molded product comprising a cured product of the epoxy resin composition.

Background Art

[0002] Conventionally, amines, acid anhydrides, polyamides, imidazoles, mercaptans, phenols, etc. are known as curing agents for epoxy resins. Since the performance of the cured product varies greatly depending on the type of the curing agent, research and development of the curing agent are promoted according to the use etc. of the epoxy resin composition.

[0003] For example, in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2011-195580), in order to obtain characteristics derived from the high planarity of the fluorene skeleton, a diamine compound having a fluorene skeleton and a substituent having an amino group bonded to the 2-position and 7-position carbon atoms in the skeleton and no substituent bonded to the 9-position carbon atom in the skeleton is disclosed. Further, it is disclosed that the diamine compound can be used as a raw material or a crosslinking agent for polyamides, polyimides, polyurethanes, epoxy resins, etc.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, from an energy efficiency perspective, there has been a surge in efforts to lighten the weight of parts in transportation machinery and other equipment by replacing metal with other materials. Cured products of thermosetting resins, including epoxy resins, are attracting attention as metal substitutes because they are lighter than metals while still possessing superior heat resistance and other properties. However, the inventors' research has shown that while using a diamine compound as disclosed in Patent Document 1 as a curing agent can reduce weight to some extent due to the fluorene skeleton, it is not sufficient to achieve both weight reduction and a good modulus of elasticity. In particular, structural components of transport machinery and the like are sometimes used in high-temperature environments, and therefore a high modulus of elasticity at high temperatures is required from the standpoint of reliability and safety.

[0006] Therefore, the inventors focused on developing new amine compounds to improve the balance between weight reduction and high elastic modulus at high temperatures, and after diligent research, completed a new amine compound in which a substituent having an amino group is attached to at least one of the carbon atoms at position 2 or 7 of the fluorene skeleton, and a substituent having an amino group attached to an aromatic ring is attached to the carbon atom at position 9 of the fluorene skeleton. [Means for solving the problem]

[0007] The present invention provides technologies relating to the following aromatic amine compounds, curing agents, and epoxy resin compositions.

[0008] [1] An aromatic amine compound represented by the following formula (1). [ka] (In formula (1), R1 and R2 are each independently hydrogen, an amino group, or an organic group, and at least one of them is an amino group or an organic group having an amino group; R3 and R4 are each independently hydrocarbon groups which may have an ester bond or an ether bond; R31-R35 and R41-R45 are each independently hydrogen, a hydrocarbon group, or an amino group, and at least one of R31-R35 or at least one of R41-R45 is an amino group.) [2] [1] Aromatic amine compounds as described above, An aromatic amine compound in which at least one of R31 to R35 and at least one of R41 to R45 are amino groups, as shown in formula (1). [3] Aromatic amine compounds as described in [1] or [2], An aromatic amine compound in which, in formula (1), the amino group in R31-R35 and R41-R45 is either a primary amino group or a secondary amino group. [4] [1] to [3] any one of the aromatic amine compounds described above, An aromatic amine compound in which both R1 and R2 have amino groups, as shown in formula (1). [5] [1] to [4] any one of the aromatic amine compounds described above, An aromatic amine compound in which both R1 and R2 have either a primary amino group or a secondary amino group, as shown in formula (1). [6] [1] to [5] any one of the aromatic amine compounds described above, The hydrocarbon groups R3 and R4 are aromatic amine compounds having 2 to 16 carbon atoms. A curing agent using any one of the aromatic amine compounds described in [7] [1] to [6]. [8] Epoxy resin and An epoxy resin composition comprising a curing agent using an aromatic amine compound represented by the following formula (1). [ka] (In formula (1), R1 and R2 are each independently hydrogen, an amino group, or an organic group, and at least one of them is an amino group or an organic group having an amino group. R3 and R4 are each independently a hydrocarbon group which may have an ester bond or an ether bond. R31 to R35 and R41 to R45 are each independently hydrogen, a hydrocarbon group, or an amino group, and at least one of R31 to R35 or at least one of R41 to R45 is an amino group.) [9] The epoxy resin composition according to [8], The epoxy resin composition wherein the ratio of the epoxy equivalent in the epoxy resin to the active hydrogen equivalent in the curing agent (epoxy / active hydrogen) is 0.8 or more and 1.5 or less.

[10] A molded article comprising a cured product of the epoxy resin composition according to [8] or [9].

[11] A molded article for a transportation device comprising a cured product of the epoxy resin composition according to any one of [8] to

[10] . [Advantages of the Invention]

[0009] According to the present invention, it is possible to provide a technique related to an aromatic amine compound, a curing agent, and an epoxy resin composition capable of improving the balance between weight reduction and a high elastic modulus at high temperatures. [Brief Description of the Drawings]

[0010] [Figure 1] It is a diagram showing the 1H-NMR measurement results of the aromatic amine compound (A1) of the example. [Figure 2] It is a diagram showing the 1H-NMR measurement results of the aromatic amine compound (A2) of the example. [Modes for Carrying Out the Invention]

[0011] Hereinafter, embodiments of the present invention will be described in detail while referring to the drawings.

[0012] In this specification, the notation "a~b" in the description of a numerical range represents a to b, unless otherwise specified. For example, "1~5 mass%" means "1 mass% or more and 5 mass% or less".

[0013] <Aromatic amine compound> The aromatic amine compound of this embodiment is represented by the following formula (1) (hereinafter, it will be described by referring to it as "aromatic amine compound (A)").

[0014] [Chemical formula] (In formula (1), R1 and R2 are each independently hydrogen, an amino group or an organic group, and at least one of them is an amino group or an organic group having an amino group. R3 and R4 are each independently a hydrocarbon group which may have an ester bond or an ether bond. R31 to R35 and R41 to R45 are each independently hydrogen, a hydrocarbon group, or an amino group, and at least one of R31 to R35 or at least one of R41 to R45 is an amino group.)

[0015] By having a structural unit represented by formula (1), the aromatic amine compound (A) can achieve a better balance between weight reduction of the cured product and high elastic modulus at high temperatures. Although the details of such reasons are not clear, first, it is considered that by using the phenylene of the fluorene skeleton as the main chain, weight reduction can be achieved while the elastic modulus can be improved due to the rigid structure. Furthermore, due to the bulky side chain bonded to the 9-position carbon atom of the fluorene skeleton, weight reduction and rigidity can be obtained, and the amino group of the side chain can form a covalent bond with an epoxy resin or the like as the base resin during curing. Such a covalent bond is difficult to break even at high temperatures, so the elastic modulus of the cured product at high temperatures can be effectively improved. In addition, since the amino group has two crosslinking points, it can be crosslinked more densely than the single crosslinking point of the hydroxyl group of the phenolic curing agent, so it is considered that the specific elastic modulus of the cured product can be increased while maintaining a low specific gravity.

[0016] In formula (1), R1 and R2 are each independently a hydrogen atom, an amino group, or an organic group, and at least one of them is an amino group or an organic group having an amino group. The organic group can be any group containing carbon, and examples include aliphatic groups which may have substituents with 1 to 20 carbon atoms, and aromatic groups which may have substituents. Among these, from the viewpoint of obtaining a good specific flexural modulus, it is preferable that the organic group be an aromatic group having at least an amino group. Furthermore, it is preferable that the organic group does not contain heteroatoms internally. Specifically, it is preferable that it does not contain ether-bonded oxygen atoms or ester bonds. Furthermore, the organic group having an amino group is preferably, for example, an aliphatic group having 1 to 6 carbon atoms and an amino group, or a divalent aromatic group having an amino group.

[0017] The amino group can be a primary amino group or a secondary amino group, but a primary amino group is preferred.

[0018] Furthermore, it is preferable that both R1 and R2 have amino groups. This increases the number of crosslinking points, making it easier to improve the modulus of elasticity.

[0019] Furthermore, in formula (1), R3 and R4 are hydrocarbon groups that may independently have an ester bond and an ether bond, respectively. By having an ester bond and an ether bond, the synthesis conditions can be made milder depending on the number of carbon atoms in the alkyl group, leading to improved productivity.

[0020] In R3 and R4, the number of carbon atoms in the hydrocarbon group is preferably 1 to 16, and more preferably 2 to 10. Setting the number of carbon atoms to be above the lower limit makes it easier to obtain toughness and lightness in the cured product. On the other hand, setting the number of carbon atoms to 16 or less makes it easier to stabilize the compound and maintain good reactivity. In R3 and R4, the hydrocarbon group may be either saturated or unsaturated, but a saturated hydrocarbon group is preferred for stability. In R3 and R4, the hydrocarbon group may be chain-like or cyclic, and may be linear or branched. R3 and R4 may be the same or different, but it is preferable that they be the same in order to obtain stable reactivity.

[0021] For example, R3 and R4 are preferably the same and are straight-chain saturated hydrocarbon groups having 2 to 16 carbon atoms.

[0022] In formula (1), R31-R35 and R41-R45 are each independently hydrogen, a hydrocarbon group, or an amino group, and at least one of R31-R35 or at least one of R41-R45 is an amino group. In short, it includes a compound in which at least one of R31-R35 or R41-R45 is an amino group.

[0023] R31 to R35 may have at least one amino group, and may have two or more amino groups. Furthermore, it is preferable that R33 is at the para position, R32 and R34 are at the meta position, or R31 and R35 are at the ortho position relative to R3, with the para position being more preferable. Similarly, R41 to R45 may have at least one amino group, or two or more may be amino groups. Furthermore, it is preferable that R43 is at the para position, R42 and R44 are at the meta position, or R41 and R45 are at the ortho position relative to R4, with the para position being more preferable.

[0024] In R31-R35 and R41-R45, the number of carbon atoms in the hydrocarbon group is preferably 1-16, and more preferably 2-10. In R31-R35 and R41-R45, the number of carbon atoms in the hydrocarbon group is preferably 1-16, and more preferably 2-10. Setting the number of carbon atoms above the lower limit of the above value makes it easier to obtain toughness and lightness in the cured product. On the other hand, setting the number of carbon atoms to 16 or less makes it easier to stabilize the compound and maintain good reactivity. In R31-R35 and R41-R45, the hydrocarbon group may be either saturated or unsaturated, but it is preferable that it be a saturated hydrocarbon group from the viewpoint of obtaining stability. In R31-R35 and R41-R45, the hydrocarbon group may be chain-like or cyclic, and may be linear or branched. R31-R35 and R41-R45 may be the same or different, but it is preferable that they be the same in order to obtain stable reactivity.

[0025] Specifically, examples include aromatic diamine compounds represented by the following formulas (A1) to (A6).

[0026] [ka]

[0027] [ka]

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] [ka]

[0032] [Manufacturing method] Next, an example of a method for producing aromatic amine compound (A) will be described. The reaction is preferably carried out under an inert gas atmosphere.

[0033] Aromatic amine compounds (A) can be obtained by reacting fluorenes with amine compounds in the presence of a basic catalyst. Specifically, two methods can be used, for example, as described in (i) and (ii) below.

[0034] (i) First, an amino group is introduced to the substituent at position 9 of the fluorene skeleton, and then amino groups are attached to the substituents at positions 2 and 7 of the fluorene skeleton. For example, nitrobenzene having an alkyl halide is reacted with fluorene under basic catalytic conditions to introduce the alkyl halide-containing nitrobenzene to the fluorene skeleton at position 9 via the halogen atom. The reaction conditions can be set as appropriate, but may be 80-180°C for 4-36 hours. Subsequently, the nitro group is reduced to an amino group under reducing conditions with a metal and an acid. Bromine and iodine are preferred halogens. The reaction conditions can be set as appropriate, but may be 40-120°C for 1-12 hours. Furthermore, an aromatic amine compound (A) is obtained by reacting an amine compound with a basic catalyst to introduce an amino group to at least one of the 2-position and 7-position of the fluorene skeleton. The reaction conditions can be set as appropriate, but may be 80-110°C for 4-36 hours.

[0035] (ii) First, amino groups are introduced to the substituents at positions 2 and 7 of the fluorene skeleton, and then an amino group is attached to the substituent at position 9 of the fluorene skeleton. For example, amino groups are introduced to the substituents at positions 2 and 7 of the fluorene skeleton using the same method as in (i). Next, the amino group of aminofluorene is protected with an inert group. This prevents the amino group from being replaced by the hydrocarbon group during the subsequent introduction of the hydrocarbon group. Next, a basic catalyst is added to introduce a nitrobenzene molecule having an alkyl group at the 9-position of the fluorene skeleton of aminofluorene. The reaction conditions can be the same as those described in (i) above. Next, an aromatic amine compound (A) is obtained by removing the inert group bonded to the amino group. Examples of the inert groups mentioned above include the tert-butoxycarbonyl (Boc) group, acetyl (Ac), benzoyl (Bz), pivaloyl (Piv) group, allyloxycarbonyl (Alloc) group, benzyloxycarbonyl (Cbz) group, and 2-(trimethylsilyl)ethoxycarbonyl (Teoc) group. The removal of the inert group is set appropriately depending on its type, but for example, when using the tert-butoxycarbonyl (Boc) group, it can be removed under acidic conditions such as trifluoroacetic acid.

[0036] Examples of basic catalysts used in methods (i) and (ii) above include alkali metal or alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide, and calcium hydroxide; carbonates such as sodium carbonate, calcium carbonate, and potassium carbonate; oxides such as lime; sulfites such as sodium sulfite; phosphates such as sodium phosphate; and amines such as ammonia, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, hexamethylenetetramine, and pyridine.

[0037] Examples of acids used to reduce the nitro group in methods (i) and (ii) above include hydrochloric acid, nitric acid, and ammonium chloride. Examples of metals used to reduce the nitro group include iron, zinc, and tin. Using these metals facilitates the amination process.

[0038] Furthermore, a palladium catalyst may be used as a catalyst to promote the coupling reaction. Examples of palladium catalysts include tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) and palladium carbon. Furthermore, when using a mixed solvent of water and an organic solvent, a phase transfer catalyst may be used to promote the reaction between the two phases. Examples of phase transfer catalysts include tetrabutylammonium chloride and tetrabutylammonium bromide.

[0039] Water is commonly used as the reaction solvent, but organic solvents may also be used. Examples of organic solvents include alcohols, ethers, ketones, aromatics, dimethyl sulfoxide (DMSO), and N,N-dimethylformamide (DMF). Specific examples of alcohols include methanol, ethanol, propyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, and glycerin. Specific examples of ethers include cyclic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, and 4-methyltetrahydropyran. Specific examples of ketones include acetone and methyl ethyl ketone. Specific examples of aromatics include toluene and xylene. These may be used individually or in combination of two or more. A mixed solvent of water, alcohols, and ethers is particularly preferred.

[0040] It is preferable that fluorenes and amine compounds are used in a molar ratio (fluorenes / amine compound) of 1 to 3. Furthermore, it is preferable that the basic catalyst is prepared in a molar ratio (basic catalyst / fluorenes) of 3 to 5 relative to the fluorenes.

[0041] The synthesis of aromatic amine compound (A) was confirmed by thin-layer chromatography and 1 This can be confirmed by 1H-NMR measurement.

[0042] [Application] Aromatic amine compound (A) can be used in the same applications as conventional aromatic amine compounds, such as a raw material, curing agent, and crosslinking agent for polycondensation polymers and thermosetting polymers like polyamides, polyimides, epoxy resins, and polyurethanes. In particular, aromatic amine compound (A) is preferred as a curing agent for epoxy resins because it improves the balance between weight reduction and elastic modulus of the cured product.

[0043] <Epoxy resin composition> The epoxy resin composition of this embodiment (hereinafter also simply referred to as "resin composition") comprises an epoxy resin and a curing agent using the above-mentioned aromatic amine compound (A). By using the aromatic amine compound (A) as a curing agent, the epoxy resin composition of this embodiment can improve both the weight reduction and elastic modulus of the cured epoxy resin composition.

[0044] [specific gravity] The specific gravity of the cured product (at 25°C) of the resin composition of this embodiment is preferably 1.30 or less, more preferably 1.25 or less, even more preferably 1.20 or less, and most preferably 1.19 or less. On the other hand, the specific gravity of the cured product (at 25°C) of the resin composition of this embodiment is preferably 1.0 or higher. By setting the specific gravity of the cured resin composition to be above the lower limit, a good elastic modulus can be obtained, and heat resistance and dimensional stability can be maintained. On the other hand, by setting the specific gravity of the cured resin composition to be below the upper limit, weight reduction can be achieved.

[0045] The details of each component included in the resin composition of this embodiment will be described below.

[0046] [Epoxy resin] Epoxy resins can be monomers, oligomers, or polymers in general that have two or more epoxy groups in a single molecule, and their molecular weight and molecular structure are not particularly limited.

[0047] Examples of epoxy resins include aromatic epoxy resins such as bisphenol-type epoxy resins (e.g., bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, water-added bisphenol A-type epoxy resin, dimer acid-modified bisphenol-type epoxy resin, etc.), novolac-type epoxy resins (e.g., phenol novolac-type epoxy resin, cresol novolac-type epoxy resin, biphenyl-type epoxy resin, etc.), naphthalene-type epoxy resins, fluorene-type epoxy resins (e.g., bisarylfluorene-type epoxy resin, etc.), triphenylmethane-type epoxy resins (e.g., trishydroxyphenylmethane-type epoxy resin, etc.), nitrogen-containing ring epoxy resins such as triepoxypropyl isocyanurate (triglycidyl isocyanurate) and hydantoin epoxy resins, aliphatic epoxy resins, alicyclic epoxy resins (e.g., dicyclocyclic epoxy resin, etc.), glycidyl ether-type epoxy resins, and glycidylamine-type epoxy resins. One of these epoxy resins may be used alone, or two or more different types may be used in combination. In particular, glycidylamine-type epoxy resins, bisphenol-type epoxy resins, phenyl-type epoxy resins, naphthalene-type epoxy resins, and fluorene-type epoxy resins are preferred, and glycidylamine-type epoxy resins are more preferred, as they have a rigid structure that effectively reduces weight while maintaining a high modulus of elasticity.

[0048] Furthermore, glycidylamine-type epoxy resins are epoxy resins having a structure in which the amino group of an amine is glycidylated, such as tetraglycidyldiaminodiphenylmethane, glycidyl compounds of xylenediamine, triglycidylaminophenol (triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, etc.), tetraglycidyldiaminodiphenylmethane, tetraglycidyldiaminodiphenylsulfone, tetraglycidyldiaminodiphenyl ether, tetraglycidylbisaminomethylcyclohexanone, diglycidyltoluidine, diglycidylaniline, diglycidylmethoxyaniline, diglycidyldimethylaniline, diglycidyltrifluoromethylaniline, and the like.

[0049] The epoxy resin content is preferably 10% to 70% by mass, more preferably 25% to 60% by mass, and even more preferably 35% to 55% by mass, based on the total amount of the resin composition. By setting the epoxy resin content above the lower limit, the fluidity and moldability of the resin composition can be more effectively improved. On the other hand, by setting the epoxy resin content below the upper limit, the curability can be improved, and a good cured product can be obtained.

[0050] [Hardening agent] The curing agent contains at least the aromatic amine compound (A) described above. The aromatic amine compound (A) functions as a polyaddition-type curing agent.

[0051] The ratio of epoxy equivalents in the epoxy resin to the active hydrogen equivalents in the curing agent (epoxy / active hydrogen) is preferably 0.8 to 1.5, and more preferably 1.1 to 1.3. By setting the ratio (epoxy / active hydrogen) to above the lower limit, the crosslinking of the amine groups of the aromatic amine compound (A) is promoted, improving curability, reducing weight, and improving elastic modulus. On the other hand, by setting the ratio (epoxy / active hydrogen) to below the upper limit, the good fluidity and moldability of the resin composition can be maintained.

[0052] The curing agent content is set appropriately depending on the epoxy resin, but is preferably 20% to 70% by mass, more preferably 30% to 65% by mass, and even more preferably 40% to 60% by mass, relative to the total amount of the resin composition. By setting the curing agent content above the lower limit, curability can be improved, and a good cured product can be obtained. On the other hand, by setting the curing agent content below the upper limit, the fluidity and moldability of the resin composition can be improved more effectively.

[0053] [Curing accelerator] The resin composition of this embodiment may also contain a curing accelerator. The curing accelerator typically accelerates the reaction between the epoxy resin and the curing agent.

[0054] Examples of curing accelerators include phenol, bisphenol A, nonylphenol, 2,3-dihydroxynaphthalene, and other phenolic compounds.

[0055] When a curing accelerator is used, the amount of the curing accelerator is set appropriately according to the application, but it is preferably 0.1 to 5% by mass, and more preferably 0.2 to 3% by mass, relative to the total amount of the resin composition. By setting the content of the curing accelerator above the lower limit, the resin composition becomes easier to cure properly. On the other hand, by setting the content of the curing accelerator below the upper limit, the molten state is prolonged, and the low viscosity state can be maintained for a longer period.

[0056] On the other hand, since the resin composition of this embodiment uses an aromatic amine compound (A) as a curing agent, good curability can be obtained even without containing a curing accelerator.

[0057] [Filling material] Fillers are used to enhance the elastic modulus, impart heat resistance, flame retardancy, and other properties depending on the intended use of the cured product.

[0058] Inorganic particles and / or organic particles are used as fillers. Examples of inorganic particles include silicates such as talc, calcined clay, uncalcined clay, mica, and glass; oxides such as fused silica, spherical silica, crushed silica, titanium oxide, and boehmite; carbonates such as calcium carbonate, magnesium carbonate, and hydrotalcite; hydroxides such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide; sulfates or sulfites such as barium sulfate, calcium sulfate, and calcium sulfite; borates such as zinc borate, barium metaborate, aluminum borate, calcium borate, and sodium borate; nitrides such as aluminum nitride, boron nitride, silicon nitride, and carbon nitride; titanates such as strontium titanate and barium titanate; and reinforcing fibers such as glass fibers, carbon fibers, and metal fibers. These may be used individually or in combination of two or more.

[0059] The amount of filler is set appropriately depending on the application, but is preferably 1 to 45% by mass, more preferably 10 to 40% by mass, and even more preferably 20 to 35% by mass, relative to the total amount of resin composition. By setting the filler content above the lower limit, the shelf life and curability of the cured product can be improved. Furthermore, by setting the filler content below the upper limit, good fluidity of the resin composition can be obtained, effectively improving moldability.

[0060] [Coupling agent] The resin composition of this embodiment may also contain a coupling agent, such as when it contains inorganic particles as a filler. This suppresses the aggregation of inorganic particles and allows for good fluidity to be obtained.

[0061] As coupling agents, known coupling agents such as various silane compounds including epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, and vinylsilane, as well as titanium compounds, aluminum chelates, and aluminum / zirconium compounds can be used.

[0062] [Other ingredients] The resin composition of this embodiment may contain other components besides those described above, as long as they do not impair the effects of the invention. Examples of other components include thermosetting resins other than epoxy resins, curing agents other than aromatic amine compounds (A), mold release agents, pigments, flame retardants, adhesion enhancers, coupling agents, and other additives. If the resin composition of this embodiment contains these other components, it may contain only one or two or more.

[0063] The resin composition of this embodiment may contain a solvent (such as an organic solvent). However, from the viewpoint of ease of distribution and handling of the resin composition and suppression of VOC generation in the work environment, it is preferable that the resin composition of this embodiment substantially does not contain a solvent (such as an organic solvent).

[0064] <Method for producing resin compositions> The resin composition of this embodiment is obtained by mixing the above components by a known method. For example, after blending the above components and mixing them uniformly, the mixture is heated, melted, and kneaded using a kneading device such as a roll, cone mixer, or twin-screw extruder alone, or in combination with a roll and other mixing device, before being granulated or pulverized.

[0065] <Molded products / Manufacturing methods for molded products> The molded article of this embodiment comprises a cured product of the above-mentioned resin composition. Alternatively, the above resin composition may be made into a varnish, and reinforcing fibers may be immersed in it to impregnate the reinforcing fibers with the resin composition of this embodiment. After that, the resin may be cured by drying and heating and pressing to achieve the desired shape, thereby forming a molded product. The curing molding conditions depend on the shape of the molded product, but for example, molding can be performed with a mold temperature of 170-250°C, a molding pressure of 0.01-10 MPa, and a curing time of 0.5-3 hours.

[0066] [Application] The applications of the molded products are not particularly limited. Examples of applications include molded products for transportation equipment such as automobiles, aircraft, railway vehicles, and ships; and various structural components for office equipment, general-purpose machinery, household electrical appliances, and electrical equipment. They can also be used in impregnation and binder applications, where they are used by impregnating various substrates such as organic fibers, metals, and glass. In particular, it is suitable for use in molded products for transportation equipment due to its lightweight nature and the fact that it can be obtained with good elastic modulus at high temperatures.

[0067] Although embodiments of the present invention have been described above, these are merely examples, and various other configurations can be adopted. Furthermore, the present invention is not limited to the embodiments described above, and modifications, improvements, etc., within the scope that can achieve the objectives of the present invention are included in the present invention. [Examples]

[0068] Embodiments of the present invention will be described in detail based on examples and comparative examples. However, the present invention is not limited to these examples.

[0069] (1) Synthesis of aromatic amine compounds (A1) to (A2) [Synthesis Example 1] The aromatic amine compound (A1) represented by the following formula (A1) was synthesized using the following procedure. (Process 1) 31.74 g of 4-nitrophenethyl bromide (manufactured by Tokyo Chemical Industries, Ltd.) was mixed with 14.9 g of 2,7-dibromofluorene (manufactured by Tokyo Chemical Industries, Ltd.), 46.6 g of 17% sodium hydroxide aqueous solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.5 g of tetrabutylammonium chloride (manufactured by Tokyo Chemical Industries, Ltd.). This mixture was heated in an oil bath under a nitrogen atmosphere to 150°C and reacted for 2 hours. The organic layer was then removed, and the organic solvent was removed to obtain 28.6 g of reaction product. (Process 2) 28.6 g of the reaction product from step 1 was dissolved in a mixed solvent of 150 g of tetrahydrofuran and 50 g of ethanol. A solution of 9.8 g of ammonium chloride (manufactured by Tokyo Chemical Industries, Ltd.) and 50 g of water was added, and 20.6 g of iron powder (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added and the mixture was reacted at 100°C for 6 hours. After the reaction, 300 g of water was added to the solution to collect the precipitated solid, and the resulting solution was purified using a silica gel column (solvent: dichloromethane) to obtain 18.0 g of the reaction product. (Step 3) To 4.5 g of the reaction product from step 2, 3.3 g of 4-aminophenylboronic acid (BLDpharm), 4.4 g of potassium carbonate (Tokyo Chemical Industries), and 0.2 g of tetrabutylammonium chloride (Tokyo Chemical Industries) were added, and 14.6 g of water and 23.5 g of tetrahydrofuran were added to the solution. To this solution, 0.2 g of tetrakis(triphenylphosphine)palladium (Tokyo Chemical Industries) was added under a nitrogen atmosphere, and the mixture was heated in an oil bath to 90°C and reacted for 8 hours. The organic layer was then removed, the organic solvent was removed, and the resulting solid was purified using a silica gel column (solvent: dichloromethane) to obtain 2.0 g of the reaction product (aromatic amine compound (A1) represented by the following formula (A1)).

[0070] [ka]

[0071] [Synthesis Example 2] The aromatic amine compound (A2) represented by the following formula (A2) was synthesized using the following procedure.

[0072] (Process 1) 6.1 g of 4-nitro-o-cresol (manufactured by Tokyo Chemical Industry Co., Ltd.) was mixed with 108.8 g of 1,8-dibromooctane (manufactured by Tokyo Chemical Industry Co., Ltd.), 11.0 g of potassium carbonate, and 108.8 g of acetone. The mixture was heated to 100°C and reacted for 2 hours. After removing the organic solvent, the mixture was purified using a silica gel column (solvent: petroleum ether) to obtain 13.8 g of the reaction product. (Process 2) To 9.1 g of the reaction product from Step 1, 3.6 g of 2,7-dibromofluorene (manufactured by Tokyo Chemical Industries, Ltd.), 12.7 g of 17% sodium hydroxide aqueous solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.1 g of tetrabutylammonium chloride (manufactured by Tokyo Chemical Industries, Ltd.) were added. This mixture was heated in an oil bath under a nitrogen atmosphere to 150°C and reacted for 2 hours. The organic layer was then removed, and the organic solvent was removed to obtain 9.4 g of reaction product. (Step 3) 9.4 g of the reaction product from step 2 was dissolved in a mixed solvent of 40 g of tetrahydrofuran and 13 g of ethanol. A solution of 2.3 g of ammonium chloride (manufactured by Tokyo Chemical Industries, Ltd.) and 13 g of water was added, and 4.9 g of iron powder (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added and the mixture was reacted at 100°C for 6 hours. After the reaction, 100 g of water was added to the solution to collect the precipitated solid, and the resulting solution was purified using a silica gel column (solvent: dichloromethane) to obtain 3.9 g of the reaction product. (Step 4) To 3.9 g of the reaction product from step 3, 2.6 g of 4-aminophenylboronic acid (BLDpharm), 2.8 g of potassium carbonate (Tokyo Chemical Industries), 0.1 g of tetrabutylammonium chloride (Tokyo Chemical Industries), 9.1 g of water, and 19.7 g of tetrahydrofuran were added and dissolved. To this solution, 0.1 g of tetrakis(triphenylphosphine)palladium (Tokyo Chemical Industries) was added under a nitrogen atmosphere, and the mixture was heated in an oil bath to 90°C and reacted for 8 hours. The organic layer was then removed, the organic solvent was removed, and the resulting solid was purified using a silica gel column (solvent: dichloromethane) to obtain 2.0 g of the reaction product (aromatic amine compound (A2) represented by the following formula (A2)).

[0073] [ka]

[0074] (2) Example: Synthesis of phenolic hydroxyl group-containing amine compound (B) [Synthesis Example 3] We synthesized the "aromatic amine compound (A1) represented by formula (A1)" as described in the examples of Japanese Patent Application No. 2024-047969. Specifically, the synthesis was as follows: (Process 1) 25.7 g of 9-bromo-1-nonanol (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 80 ml of dichloromethane. To this solution, 14.5 g of 3,4-dihydropyran (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise under ice bath conditions, followed by the addition of 1.6 g of p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.). The reaction was carried out at room temperature for 16 hours. After removing the organic solvent, the resulting liquid was purified using a silica gel column (solvent: dichloromethane) to obtain 30.2 g of the reaction product. (Process 2) To 28.24 g of the reaction product from step 1, 7.4 g of 2,7-dibromofluorene (manufactured by Tokyo Chemical Industries, Ltd.), 35.7 g of 17% sodium hydroxide aqueous solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.4 g of tetrabutylammonium chloride (manufactured by Tokyo Chemical Industries, Ltd.) were added. This mixture was heated to 150°C in an oil bath under a nitrogen atmosphere and reacted for 2 hours. The organic layer was then removed, the organic solvent was removed, and the resulting solid was purified using a silica gel column (solvent: dichloromethane) to obtain 18.0 g of the reaction product. (Step 3) To 15.5 g of the reaction product from step 2, 13.8 g of 4-aminophenylboronic acid (BLDpharm), 11.0 g of potassium carbonate (Tokyo Chemical Industries), and 0.5 g of tetrabutylammonium chloride (Tokyo Chemical Industries) were dissolved in 36.4 g of water and 117.5 g of tetrahydrofuran. To this solution, 0.5 g of tetrakis(triphenylphosphine)palladium (Tokyo Chemical Industries) was added under a nitrogen atmosphere, and the mixture was heated in an oil bath to 90°C and reacted for 8 hours. The organic layer was then removed, the organic solvent was removed, and the resulting solid was purified using a silica gel column (solvent: dichloromethane) to obtain 14.0 g of the reaction product. (Step 4) 13.6 g of the reaction product from step 3 was dissolved in a mixed solvent of 30 g methanol, 30 g ethanol, and 1.5 g dichloromethane, and 9.7 g of p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and the mixture was reacted at 60°C for 8 hours. Subsequently, a saturated aqueous solution of sodium bicarbonate was added to the reaction solution, the organic layer was removed and washed with water, and the organic solvent was removed. The resulting solid was purified using a silica gel column (solvent: dichloromethane) to obtain 4.0 g of the reaction product (phenolic hydroxyl group-containing amine compound (B) represented by the following formula (B)).

[0075] [ka]

[0076] (3)Analysis and measurement The obtained aromatic amine compounds (A1) to (A2) were subjected to the following conditions. 1 1H-NMR was measured. The results are shown in Figures 1 and 2, respectively. The letters a to c in Figures 1 and 2 correspond to the structures represented by the following formulas (A1') and (A2').

[0077] < 1 H-NMR measurement conditions> Equipment: JEOL Ltd. JNM-ECA400 Solvent: (A1)(A2)Chloroform-d (A3) DMSO (dimethyl sulfoxide)-d6 Pulse angle: 45° Sample concentration: 3 wt% Total number of times: 16

[0078] [ka]

[0079] [ka]

[0080] 1¹H-NMR measurements confirmed that aromatic amine compounds (A1) and (A2) have the structures shown in formulas (A1) and (A2), respectively, and possess the fluorene structure shown in formula (1).

[0081] (4) Preparation of epoxy resin composition <Examples and Comparative Examples> The following raw materials were mixed to obtain the compositions (mass%) shown in Table 1, kneaded on a hot plate at 150°C for 30 seconds, and then removed to obtain each epoxy resin composition.

[0082] [Raw materials] • Epoxy resin: Tetraglycidyldiaminodiphenylmethane (TGDDM, manufactured by Tokyo Chemical Industry Co., Ltd.) • Curing agent 1: Aromatic amine compound (A1) obtained in synthesis example 1 of (1) above. • Curing agent 2: Aromatic amine compound (A2) obtained in synthesis example 2 of (1) above. • Curing agent 3: Phenolic hydroxyl group-containing amine compound (B) obtained in synthesis example 3 of (2) above. • Hardener 4:4,4'-diaminodiphenylsulfone (DDS, manufactured by Tokyo Chemical Industry Co., Ltd.)

[0083] (5) Evaluation Each of the obtained resin compositions was cured under the curing conditions shown in Table 1 to obtain molded products.

[0084] The following evaluations and measurements were performed on the obtained molded products. The results are shown in Table 1. • Specific gravity: The specific gravity of each molded product was determined using the water displacement method. • Elastic modulus: A test specimen with a width of 10 mm, a thickness of 1 mm, and a length of 100 mm was prepared, and the elastic modulus (GPa) at 25°C and the elastic modulus (GPa) at 100°C were measured, respectively. • Specific modulus of elasticity: Calculated by dividing the above modulus of elasticity by the specific gravity.

[0085] [Table 1]

Claims

1. An aromatic amine compound represented by the following formula (1). 【Chemistry 1】 (In formula (1), R1 and R2 are each independently hydrogen, an amino group, or an organic group, and at least one of them is an amino group or an organic group having an amino group; R3 and R4 are each independently hydrocarbon groups which may have an ester bond or an ether bond; R31 to R35 and R41 to R45 are each independently hydrogen, a hydrocarbon group, or an amino group, and at least one of R31 to R35 or at least one of R41 to R45 is an amino group.)

2. The aromatic amine compound according to claim 1, An aromatic amine compound in which at least one of R31 to R35 and at least one of R41 to R45 are amino groups, as shown in formula (1).

3. An aromatic amine compound according to claim 1 or 2, An aromatic amine compound in which, in formula (1), the amino group in R31 to R35 and R41 to R45 is a primary amino group or a secondary amino group.

4. An aromatic amine compound according to claim 1 or 2, An aromatic amine compound in which both R1 and R2 have amino groups, as shown in formula (1).

5. An aromatic amine compound according to claim 1 or 2, An aromatic amine compound in which both R1 and R2 have either a primary amino group or a secondary amino group, as shown in formula (1).

6. An aromatic amine compound according to claim 1 or 2, The hydrocarbon groups R3 and R4 are aromatic amine compounds having 2 to 16 carbon atoms.

7. A curing agent using the aromatic amine compound described in claim 1 or 2.

8. Epoxy resin and An epoxy resin composition comprising a curing agent using an aromatic amine compound represented by the following formula (1). 【Chemistry 2】 (In formula (1), R1 and R2 are each independently hydrogen, an amino group, or an organic group, and at least one of them is an amino group or an organic group having an amino group; R3 and R4 are each independently hydrocarbon groups which may have an ester bond or an ether bond; R31 to R35 and R41 to R45 are each independently hydrogen, a hydrocarbon group, or an amino group, and at least one of R31 to R35 or at least one of R41 to R45 is an amino group.)

9. The epoxy resin composition according to claim 8, An epoxy resin composition in which the ratio of epoxy equivalents in the epoxy resin to the active hydrogen equivalents in the curing agent (epoxy / active hydrogen) is 0.8 or more and 1.5 or less.

10. A molded article comprising a cured product of the epoxy resin composition according to claim 8 or 9.

11. A transport equipment molded article comprising a cured product of the epoxy resin composition according to claim 8 or 9.

Images