Aromatic amine compound, curing agent, epoxy resin composition, and method for producing aromatic amine compound

Abstract

To provide an aromatic amine compound that enables improvement of balance between superior mechanical characteristics and light weight.SOLUTION: This aromatic amine compound of the present invention is represented by Formula (1). (In Formula (1), R1 and R2 are each independently hydrogen, an amino group, or an organic group, at least one of which is an amino group or an organic group having an amino group; R3 and R4 are each independently a hydrocarbon group having 3 to 18 carbon atoms, at least one of which has a hydroxyl group).SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Known curing agents for epoxy resins include amines, acid anhydrides, polyamides, imidazoles, mercaptans, phenols, etc. Since the performance of the cured product varies greatly depending on the type of curing agent, research and development of curing agents is being conducted according to the application of the epoxy resin composition.

[0003] For example, Patent Document 1 (JP 2011-195580 A) discloses a diamine compound having a fluorene skeleton, in which amino group-containing substituents are bonded to the carbon atoms at positions 2 and 7 of the skeleton, but no substituent is bonded to the carbon atom at position 9 of the skeleton, in order to obtain properties derived from the high planarity of the fluorene skeleton. It also discloses that the diamine compound can be used as a raw material or crosslinking agent for polyamide, polyimide, polyurethane, epoxy resin, etc. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-195580 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, from the viewpoint of energy efficiency, weight reduction by replacing metals in parts of transportation machinery and the like has become popular. Cured products of thermosetting resins, including epoxy resins, are attracting attention as metal replacement parts because they are lighter than metals yet have excellent heat resistance. However, according to the investigations of the present inventors, when a diamine compound as disclosed in Patent Document 1 is used as a curing agent, although weight reduction can be achieved to some extent by the fluorene skeleton, there is still room for improvement in the modulus of elasticity and strength, and it has been found that it is not sufficient to achieve both weight reduction and good mechanical properties.

[0006] Therefore, the present inventors have focused on the development of new amine compounds in order to improve the balance between weight reduction and good mechanical properties, and have conducted extensive research. As a result, they have completed a new amine compound in which a substituent having an amino group is bonded to at least one of the carbon atoms at the 2nd or 7th position of the fluorene skeleton, and a substituent having a hydroxyl group is bonded to the carbon atom at the 9th position of the fluorene skeleton. [Means for solving the problem]

[0007] According to the present invention, the following technologies relating to an aromatic amine compound, a curing agent, and an epoxy resin composition are provided.

[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 a hydrocarbon group having 3 to 18 carbon atoms, and at least one of them has a hydroxyl group.) [2] The aromatic amine compound according to [1], An aromatic amine compound represented by formula (1), wherein the hydrocarbon group is a linear or branched hydrocarbon group. [3] The aromatic amine compound according to [1] or [2], An aromatic amine compound represented by formula (1), wherein the hydrocarbon group has a terminal hydroxyl group. [4] The aromatic amine compound according to any one of [1] to [3], An aromatic amine compound, wherein in formula (1), the hydrocarbon group is a saturated hydrocarbon group. [5] The aromatic amine compound according to any one of [1] to [4], An aromatic amine compound represented by formula (1), wherein R1 and R2 each have an amino group. [6] The aromatic amine compound according to any one of [1] to [5], An aromatic amine compound represented by formula (1), wherein the amino group is a primary amino group. [7] The aromatic amine compound according to any one of [1] to [6]. An aromatic amine compound in which the organic group in formula (1) is an aliphatic group having 1 to 6 carbon atoms and having an amino group, or a divalent aromatic group having an amino group. [8] A curing agent using the aromatic amine compound according to any one of [1] to [7]. [9] Epoxy resin; and 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 having 3 to 18 carbon atoms, and at least one of them has a hydroxyl group.)

[10] The epoxy resin composition according to [9], An 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.

[11] The epoxy resin composition according to [9] or

[10] , An epoxy resin composition, wherein in formula (1), the hydrocarbon group is a linear or branched hydrocarbon group.

[12] The epoxy resin composition according to any one of [9] to

[11] , An epoxy resin composition, wherein in formula (1), the hydrocarbon group has a hydroxyl group at its terminal.

[13] The epoxy resin composition according to any one of [9] to

[12] , An epoxy resin composition, wherein in formula (1), the hydrocarbon group is a saturated hydrocarbon group.

[14] The epoxy resin composition according to any one of [9] to

[13] , An epoxy resin composition represented by formula (1), wherein R1 and R2 each have an amino group.

[15] The epoxy resin composition according to any one of [9] to

[14] , An epoxy resin composition, wherein in formula (1), the amino group is a primary amino group.

[16] The epoxy resin composition according to any one of [9] to

[15] . An epoxy resin composition, wherein in formula (1), the organic group is an aliphatic group having 1 to 6 carbon atoms and having an amino group, or a divalent aromatic group having an amino group.

[17] A method for producing an aromatic amine compound, comprising a reaction step of reacting, in the presence of a basic catalyst, a fluorene having a hydrocarbon group having 3 to 18 carbon atoms and a hydroxyl group and an amine compound, or a fluorene having an amino group bonded to at least one of the 2- and 7-positions of the fluorene skeleton and a compound having a hydrocarbon group having 3 to 18 carbon atoms and a hydroxyl group.

[18] In the method for producing an aromatic amine compound according to

[17] , The method for producing an aromatic amine compound further comprises a protection step of protecting the hydroxyl group and / or the amino group with an inert group before the reaction step.

[19] In the method for producing an aromatic amine compound according to

[18] , The method for producing an aromatic amine compound further comprises, after the reaction step, a removal step of removing the inactive group.

[20] In the method for producing an aromatic amine compound according to

[17] or

[18] , The reaction step is carried out by heating at 80 to 180°C, in accordance with the method for producing an aromatic amine compound.

[21] A molded article comprising a cured product of the epoxy resin composition according to any one of [9] to

[15] .

[22] A molded transportation equipment product comprising a cured product of the epoxy resin composition according to any one of [9] to

[15] . [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a technology relating to an aromatic amine compound, a curing agent, and an epoxy resin composition that can improve the balance between good mechanical properties and weight reduction. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing the results of 1H-NMR measurement of an aromatic amine compound (A1) of an example. DETAILED DESCRIPTION OF THE INVENTION

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

[0012] In this specification, unless otherwise specified, the expression "a to b" in the description of a numerical range means from a to b. For example, "1 to 5 mass %" means "1 mass % to 5 mass %."

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

[0014] [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 having 3 to 18 carbon atoms, and at least one of them has a hydroxyl group.)

[0015] The aromatic amine compound (A) has a structural unit represented by formula (1), which allows the cured product to have a lighter weight while still providing excellent mechanical properties at a higher level. Although the details of this mechanism are not clear, it is thought that this is due to the combined effects of the following: - The multiple aromatic groups in the fluorene skeleton increase rigidity and mechanical strength. By bonding a hydrocarbon group to the 9th carbon atom in the fluorene skeleton, toughness is achieved while maintaining a low specific gravity, making it easier to improve the elastic modulus per specific gravity. The presence of a hydroxyl group in the hydrocarbon group leads to intermolecular interactions, which in turn enhances mechanical strength through intermolecular forces. At the same time, the presence of a hydroxyl group in the relatively bulky hydrocarbon group is thought to inhibit reaction with the epoxy group when used as a curing agent for epoxy resin. The amino groups at the 2 and 7 positions of the fluorene skeleton have two crosslinking points, allowing for more dense crosslinking than the single crosslinking point of the hydroxyl group found in phenolic curing agents, thereby increasing the mechanical strength of the cured product while maintaining a low specific gravity.

[0016] In formula (1), R1 and R2 each independently represent 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 may be any group containing carbon, and examples thereof include an aliphatic group having 1 to 20 carbon atoms which may have a substituent, and an aromatic group which may have a substituent. Of these, from the viewpoint of obtaining good strength, an aromatic group having at least an amino group is preferred. The organic group preferably does not contain a hetero element therein, specifically, it does not contain an ether-bonded oxygen atom or an ester bond. The organic group having an amino group is preferably, for example, an aliphatic group having 1 to 6 carbon atoms and having an amino group, or a divalent aromatic group having an amino group.

[0017] The amino group may be a primary amino group or a secondary amino group, with a primary amino group being preferred.

[0018] It is also preferable that both R1 and R2 have an amino group, which increases the number of crosslinking points and makes it easier to improve mechanical properties.

[0019] In addition, in formula (1), R3 and R4 are each independently a hydrocarbon group having 3 to 18 carbon atoms, and at least one of them has a hydroxyl group. The number of carbon atoms is preferably 4 to 16, more preferably 6 to 14, and even more preferably 8 to 12. By making the number of carbon atoms 3 or more, the bulk is increased, toughness is obtained, and the elastic modulus is improved, and light weight is also easily obtained. On the other hand, by making the number of carbon atoms 18 or less, the compound is stabilized, and good reactivity is easily maintained. The hydrocarbon group may be saturated or unsaturated, but is preferably a saturated hydrocarbon group from the viewpoint of obtaining stability.

[0020] R3 and R4 each independently represent a hydrocarbon group that may be either a chain or a cyclic group, and are preferably straight-chain or branched hydrocarbon groups, or divalent chain hydrocarbon groups to which a cyclic hydrocarbon group is bonded. Specifically, it is preferred that both R3 and R4 are straight-chain hydrocarbon groups having 8 to 12 carbon atoms. By making them straight-chain, toughness is more easily obtained.

[0021] At least one of R3 and R4 has at least one hydroxyl group, and from the viewpoint of enhancing intermolecular interactions and improving strength, it is preferable that both R3 and R4 have hydroxyl groups. The hydroxyl group may be located anywhere on the hydrocarbon group, for example, at the end of a linear hydrocarbon group or at the end of a branch of a branched hydrocarbon group.

[0022] Specific examples include aromatic diamine compounds represented by the following formulas (A1) to (A7).

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] [ka]

[0027] [ka]

[0028] [ka]

[0029] [ka]

[0030] [Manufacturing method] Next, an example of a method for producing the aromatic amine compound (A) will be described. The reaction is preferably carried out in an inert gas atmosphere.

[0031] The method for producing an aromatic amine compound includes a reaction step of reacting, in the presence of a basic catalyst, a fluorene having a hydrocarbon group of 3 to 18 carbon atoms and a hydroxyl group with an amine compound, or a fluorene having an amino group bonded to at least one of the 2- and 7-positions of the fluorene skeleton with a compound having a hydrocarbon group of 3 to 18 carbon atoms and a hydroxyl group. Specifically, for example, the following two procedures (i) and (ii) can be mentioned.

[0032] (i) First, a fluorene having a hydrocarbon group having 3 to 18 carbon atoms and a hydroxyl group is prepared. The fluorene is a substituted fluorene in which a hydrocarbon group having 3 to 18 carbon atoms, at least one of which has a hydroxyl group, is introduced to the 9th position of the fluorene skeleton. The substituted fluorene may be a commercially available product or may be synthesized by a known method. For example, a bromoalkanol may be introduced to the 9th position of the fluorene skeleton by a nucleophilic substitution reaction. If there are concerns about the chemical stability or side reactions of hydrocarbon groups containing hydroxyl groups, the hydroxyl groups can be protected in advance with inert groups, such as tetrahydropyranyl (THP), trialkylsilyl (TAS), acetyl (Ac), benzyl (Bn), and allyl groups. Next, the substituted fluorene is reacted with an amine compound in the presence of a basic catalyst to introduce an amino group into at least one of the 2- and 7-positions of the fluorene skeleton, thereby obtaining aromatic amine compound (A). The reaction conditions are appropriately set, but may be 80 to 110°C and 4 to 36 hours. When the hydroxyl group is protected with an inert group, the inert group bonded to the hydroxyl group is subsequently removed to obtain the aromatic amine compound (A). The method for removing the inert group is appropriately determined depending on the type of the inert group. For example, when a tetrahydropyranyl (THP) group is used, it can be removed under acidic conditions such as with p-toluenesulfonic acid.

[0033] (ii) First, an aminofluorene is prepared in which an amino group is bonded to at least one of the 2- and 7-positions of the fluorene skeleton. Commercially available aminofluorenes may be used, or they may be synthesized by known methods. Subsequently, the amino group of the aminofluorene may be protected with an inert group. This prevents the amino group from being replaced by a hydrocarbon group during subsequent introduction of the hydrocarbon group. Next, in the presence of a basic catalyst, the aminofluorene is reacted with a compound having a hydrocarbon group of 3 to 18 carbon atoms and a hydroxyl group to introduce the hydrocarbon group of 3 to 18 carbon atoms and a hydroxyl group into the 9-position of the fluorene skeleton. The reaction conditions are appropriately set, but may be 80 to 180°C and 4 to 36 hours. The introduction of the hydrocarbon group having a hydroxyl group and the protection of the hydroxyl group can be performed in the same manner as described in (i) above. Furthermore, when the amino group is protected with an inert group, the inert group bonded to the amino group is subsequently removed to obtain aromatic amine compound (A). Examples of such inert groups include 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 method for the inert group is determined appropriately depending on the type of inert group. For example, when a tert-butoxycarbonyl (Boc) group is used, it can be removed under acidic conditions such as trifluoroacetic acid. When the hydroxyl group is protected with an inert group, it is subsequently removed by the same method as described in (i) above.

[0034] Examples of the basic catalyst used in the above methods (i) and (ii) include hydroxides of alkali metals or alkaline earth metals such as sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.; carbonates such as sodium carbonate, calcium carbonate, potassium carbonate, etc.; oxides such as lime; sulfites such as sodium sulfite; phosphates such as sodium phosphate, etc.; amines such as ammonia, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, hexamethylenetetramine, pyridine, etc.

[0035] A palladium catalyst may also be used to promote the coupling reaction, such as tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) or palladium on carbon. When a mixed solvent of water and an organic solvent is used, a phase transfer catalyst such as tetrabutylammonium chloride or tetrabutylammonium bromide may be used to promote the reaction between the two phases.

[0036] The reaction solvent is generally water, but an organic solvent 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 alone or in combination of two or more. Among these, a mixed solvent of water, alcohols, and ethers is preferred.

[0037] The fluorenes and the amine compound are preferably used in a molar ratio (fluorenes / amine compound) of 1 to 3. The basic catalyst is preferably prepared in a molar ratio (basic catalyst / fluorenes) of 3 to 5 relative to the fluorenes.

[0038] The synthesis of aromatic amine compound (A) was confirmed by thin layer chromatography and 1This can be confirmed by H-NMR measurement.

[0039] [Application] The aromatic amine compound (A) can be used in the same applications as conventional aromatic amine compounds, such as raw materials for polycondensation polymers such as polyamides, polyimides, epoxy resins, and polyurethanes, thermosetting polymers, curing agents, crosslinking agents, etc. Among these, the aromatic amine compound (A) is suitable as a curing agent for epoxy resins, from the viewpoint of improving the balance between weight reduction and good mechanical properties of the cured product.

[0040] <Epoxy resin composition> The epoxy resin composition of this embodiment (hereinafter also referred to simply as "resin composition") contains an epoxy resin and a curing agent using the aromatic amine compound (A) described above. 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 good mechanical properties of the cured product of the epoxy resin composition.

[0041] [specific gravity] The specific gravity of the cured product (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 particularly preferably 1.18 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 more. By setting the specific gravity of the cured product of the resin composition to the above lower limit or more, good strength and elastic modulus can be obtained and heat resistance and dimensional stability can be maintained, while by setting the specific gravity of the cured product of the resin composition to the above upper limit or less, weight reduction can be achieved.

[0042] Hereinafter, each component contained in the resin composition of the present embodiment will be described in detail.

[0043] [Epoxy resin] The epoxy resin may be any monomer, oligomer, or polymer having two or more epoxy groups in one molecule, and there are no particular limitations on the molecular weight or molecular structure.

[0044] Examples of epoxy resins include aromatic epoxy resins such as bisphenol-type epoxy resins (e.g., bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, hydrated bisphenol A-type epoxy resins, and dimer acid-modified bisphenol-type epoxy resins), novolac-type epoxy resins (e.g., phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, and biphenyl-type epoxy resins), naphthalene-type epoxy resins, fluorene-type epoxy resins (e.g., bisarylfluorene-type epoxy resins), and triphenylmethane-type epoxy resins (e.g., trishydroxyphenylmethane-type epoxy resins). Examples of epoxy resins include nitrogen-containing ring-containing epoxy resins such as triepoxypropyl isocyanurate (triglycidyl isocyanurate) and hydantoin epoxy resins. Examples of epoxy resins include aliphatic epoxy resins, alicyclic epoxy resins (e.g., dicyclocyclic epoxy resins), glycidyl ether-type epoxy resins, and glycidylamine-type epoxy resins. These epoxy resins may be used singly or in combination. Among these, 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, in that they have a rigid structure and thereby effectively reduce weight while maintaining mechanical strength.

[0045] Furthermore, the glycidyl amine type epoxy resin is, for example, an epoxy resin having a structure in which the amino group of an amine is glycidylated, and examples thereof include tetraglycidyl diaminodiphenylmethane, glycidyl compounds of xylenediamine, triglycidyl aminophenol (triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, etc.), tetraglycidyl diaminodiphenylmethane, tetraglycidyl diaminodiphenyl sulfone, tetraglycidyl diaminodiphenyl ether, tetraglycidyl bisaminomethylcyclohexanone, diglycidyl toluidine, diglycidyl aniline, diglycidyl methoxyaniline, diglycidyl dimethylaniline, and diglycidyl trifluoromethylaniline.

[0046] The content of the epoxy resin is preferably 10% by mass or more and 70% by mass or less, more preferably 25% by mass or more and 60% by mass or less, and even more preferably 35% by mass or more and 55% by mass or less, based on the total amount of the resin composition. By setting the content of the epoxy resin to the above lower limit or more, the flowability and moldability of the resin composition can be more effectively improved, while by setting the content of the epoxy resin to the above upper limit or less, the curability can be improved and a good cured product can be obtained.

[0047] [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.

[0048] The ratio of the epoxy equivalent in the epoxy resin to the active hydrogen equivalent in the curing agent (epoxy / active hydrogen) is preferably 0.8 or more and 1.5 or less, and more preferably 1.1 or more and 1.3 or less. By setting the ratio (epoxy / active hydrogen) to the above lower limit or more, crosslinking of the amine groups of the aromatic amine compound (A) can be promoted, curability can be improved, and weight reduction and mechanical strength can be improved. On the other hand, by setting the ratio (epoxy / active hydrogen) to the above upper limit or less, good fluidity and moldability of the resin composition can be maintained.

[0049] The content of the curing agent is set appropriately depending on the epoxy resin, but is preferably 20% by mass or more and 70% by mass or less, more preferably 30% by mass or more and 65% by mass or less, and even more preferably 40% by mass or more and 60% by mass or less, relative to the total amount of the resin composition. By setting the content of the curing agent to the above lower limit or more, it is possible to improve the curability and obtain a good cured product, whereas by setting the content of the curing agent to the above upper limit or less, it is possible to more effectively improve the flowability and moldability of the resin composition.

[0050] [Curing accelerator] The resin composition of the present embodiment may contain a curing accelerator. The curing accelerator typically accelerates the reaction between the epoxy resin and the curing agent.

[0051] Specific examples of the curing accelerator include phenolic compounds such as phenol, bisphenol A, nonylphenol, and 2,3-dihydroxynaphthalene.

[0052] When a curing accelerator is used, the content of the curing accelerator is appropriately set depending on the application, but may be 0.1 to 5 mass % or 0.2 to 3 mass % relative to the total amount of the resin composition. By setting the content of the curing accelerator to be equal to or greater than the above lower limit, the resin composition can be appropriately cured. On the other hand, by setting the content of the curing accelerator to be equal to or less than the above upper limit, the molten state can be prolonged, and the low-viscosity state can be prolonged.

[0053] On the other hand, the resin composition of the present embodiment uses the aromatic amine compound (A) as a curing agent, and therefore can achieve good curability even without containing a curing accelerator. The resin composition of the present embodiment preferably does not contain a curing accelerator.

[0054] [Filling material] Fillers are used to increase the mechanical strength and to impart heat resistance, flame retardancy, etc. depending on the intended use of the cured product.

[0055] As the filler, inorganic particles and / or organic particles are used. Specific 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 fiber, carbon fiber, and metal fiber. These may be used alone or in combination of two or more.

[0056] The content of the filler is appropriately set depending on the application, but is preferably 1 to 45 mass %, more preferably 10 to 40 mass %, and even more preferably 20 to 35 mass %, based on the total amount of the resin composition. By setting the content of the filler to the above lower limit or more, the shelf life and curability of the cured product can be improved, while by setting the content of the filler to the above upper limit or less, good fluidity of the resin composition can be obtained, and moldability can be effectively improved.

[0057] [Coupling agent] The resin composition of the present embodiment may contain a coupling agent when it contains inorganic particles as a filler, etc. This can suppress aggregation of the inorganic particles and provide good flowability.

[0058] As the coupling agent, known coupling agents such as various silane-based compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, and vinylsilane, titanium-based compounds, aluminum chelates, and aluminum / zirconium-based compounds can be used.

[0059] [Other ingredients] The resin composition of this embodiment may contain other components in addition to the components described above, as long as the effects of the invention are not impaired. Examples of other components include thermosetting resins other than epoxy resins, curing agents other than the aromatic amine compound (A), and additives such as release agents, pigments, flame retardants, adhesion improvers, and coupling agents. When the resin composition of the present embodiment contains these other components, it may contain only one kind, or may contain two or more kinds.

[0060] The resin composition of the present embodiment may contain a solvent (organic solvent, etc.). However, from the viewpoints of ease of distribution and handling of the resin composition, suppression of VOC generation in the working environment, etc., it is preferable that the resin composition of the present embodiment is substantially free of a solvent (organic solvent, etc.).

[0061] <Method of manufacturing resin composition> The resin composition of the present embodiment can be produced by mixing the above components by a known method, for example, by blending the above components to uniformity, then melt-kneading the mixture by heating using a kneading device such as a roll, a co-kneader, or a twin-screw extruder, or by combining a roll with another mixing device, followed by granulation or pulverization.

[0062] <Molded products / manufacturing methods for molded products> The molded article of this embodiment comprises a cured product of the above-described resin composition. Alternatively, the resin composition may be made into a varnish, and reinforcing fibers may be immersed in the varnish to impregnate the reinforcing fibers with the resin composition of the present embodiment. The resulting varnish may then be dried and hot-pressed to a desired shape to harden the resin and produce a molded article. The curing and molding conditions vary depending on the shape of the molded product, but for example, molding can be performed at a mold temperature of 170 to 250°C, a molding pressure of 0.01 to 10 MPa, and a curing time of 0.5 to 3 hours.

[0063] [Application] The uses of the molded articles are not particularly limited. Examples of uses include molded articles for transportation equipment such as automobiles, aircraft, railway vehicles, and ships; and various structural members for office equipment, general-purpose machines, household electrical appliances, and electrical equipment. The molded articles can also be used for impregnation and binder applications in which they are impregnated into various substrates such as organic fibers, metals, and glass. Among these, it is suitable for use in molded articles for transportation equipment because of its light weight and good mechanical properties.

[0064] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0065] The present invention will be described in detail based on examples and comparative examples, but the present invention is not limited to these examples.

[0066] (1) Synthesis of aromatic amine compounds (A1) and phenol compounds (B) [Synthesis Example 1] An aromatic amine compound (A1) represented by the following formula (A1) was synthesized according to the following steps 1 to 4. 〇Process 1 25.7 g of 9-bromo-1-nonanol (Tokyo Chemical Industry Co., Ltd.) was dissolved in 80 ml of dichloromethane. 14.5 g of 3,4-dihydropyran (Tokyo Chemical Industry Co., Ltd.) was added dropwise to this solution in an ice bath, followed by the addition of 1.6 g of p-toluenesulfonic acid (Tokyo Chemical Industry Co., Ltd.), and the reaction was carried out at room temperature for 16 hours. The organic solvent was then removed, and the resulting liquid was purified using a silica gel column (solvent: dichloromethane) to obtain 30.2 g of reaction product. 〇Process 2 To 28.24 g of the reaction product from step 1, 7.4 g of 2,7-dibromofluorene (Tokyo Chemical Industry Co., Ltd.), 35.7 g of 17% aqueous sodium hydroxide solution (Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.4 g of tetrabutylammonium chloride (Tokyo Chemical Industry Co., 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 and the organic solvent was removed. The resulting solid was purified using a silica gel column (solvent: dichloromethane) to obtain 18.0 g of reaction product. 〇Process 3 15.5 g of the reaction product from step 2 was dissolved in 13.8 g of 4-aminophenylboronic acid (manufactured by BLDpharm), 11.0 g of potassium carbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.5 g of tetrabutylammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), 36.4 g of water, and 117.5 g of tetrahydrofuran. 0.5 g of tetrakis(triphenylphosphine)palladium (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to this solution under a nitrogen atmosphere, and the mixture was heated to 90°C in an oil bath 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 reaction product. 〇Process 4 13.6 g of the reaction product from step 3 was dissolved in a mixed solvent of 30 g of methanol, 30 g of ethanol, and 1.5 g of dichloromethane, and 9.7 g of p-toluenesulfonic acid (Tokyo Chemical Industry Co., Ltd.) was added and reacted for 8 hours at 60° C. Subsequently, a saturated aqueous solution of sodium hydrogen carbonate was added to the reaction solution, the organic layer was separated and washed with water, the organic solvent was removed, and the resulting solid was purified using a silica gel column (solvent: dichloromethane) to obtain 4.0 g of a reaction product.

[0067] [Synthesis Example 2] A phenol compound (B) represented by the following formula (B) was synthesized by the following procedure. 19.0 g of 4-hydroxyphenylboronic acid (Tokyo Chemical Industry Co., Ltd.), 25.3 g of 2,7-dibromo-9,9-di-n-octylfluorene (Tokyo Chemical Industry Co., Ltd.), 25.4 g of potassium carbonate (Tokyo Chemical Industry Co., Ltd.), and 2.5 g of tetrabutylammonium chloride (Tokyo Chemical Industry Co., Ltd.) were dissolved in 83.8 g of water, 155.0 g of tetrahydrofuran, and 31.0 g of ethanol. 2.1 g of tetrakis(triphenylphosphine)palladium (Tokyo Chemical Industry Co., Ltd.) was added to this solution under a nitrogen atmosphere, heated to 90 °C in an oil bath, and reacted for 24 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 16.8 g of reaction product.

[0068] [ka]

[0069] (2)Analysis and measurement The obtained aromatic amine compound (A1) was subjected to the following reaction under the following conditions: 1 H-NMR was measured, and the results are shown in Figure 1. In Figure 1, the letters a to c correspond to the structure represented by the following formula (A1').

[0070] < 1 H-NMR measurement conditions> Equipment: JEOL Ltd. JNM-ECA400 Solvent: DMSO (dimethyl sulfoxide)-d6 Pulse angle: 45° Sample concentration: 3 wt% Accumulation count: 16 times

[0071] [ka]

[0072] 1 The structure of the aromatic amine compound (A1) was confirmed by H-NMR measurement.

[0073] (3) Preparation of epoxy resin composition <Examples and Comparative Examples> The following raw material components 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.

[0074] [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: 4,4'-diaminodiphenyl sulfone (Tokyo Chemical Industry Co., Ltd.) Curing agent 3: the phenol compound (B) obtained in Synthesis Example 2 of (1) above Curing accelerator: Triphenylphosphine (Tokyo Chemical Industry Co., Ltd.)

[0075] (4) Evaluation Each of the resulting resin compositions was cured under the curing conditions shown in Table 1 to obtain a molded article. The molded articles were then subjected to the following evaluations and measurements, and the results are shown in Table 1. Specific gravity: The specific gravity of each molded product was determined by the underwater displacement method. Specific strength (MPa): A test piece measuring 10 mm in width, 1 mm in thickness, and 100 mm in length was prepared, and the bending strength (MPa) at 25°C was measured and calculated by dividing by the specific gravity. Specific elastic modulus (GPa): A test piece 10 mm wide, 1 mm thick, and 100 mm long was prepared, and the flexural modulus (GPa) at 25°C was measured and calculated by dividing by the specific gravity.

[0076] [Table 1]

Claims

1. An aromatic amine compound represented by the following formula (1): 【Chemical 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 a hydrocarbon group having 3 to 18 carbon atoms, and at least one of them has a hydroxyl group.)

2. The aromatic amine compound according to claim 1, An aromatic amine compound represented by formula (1), wherein the hydrocarbon group is a linear or branched hydrocarbon group.

3. The aromatic amine compound according to claim 1 or 2, An aromatic amine compound represented by formula (1), wherein the hydrocarbon group has a terminal hydroxyl group.

4. The aromatic amine compound according to claim 1 or 2, An aromatic amine compound represented by formula (1), wherein the hydrocarbon group is a saturated hydrocarbon group.

5. The aromatic amine compound according to claim 1 or 2, An aromatic amine compound represented by formula (1), wherein R1 and R2 each have an amino group.

6. The aromatic amine compound according to claim 1 or 2, An aromatic amine compound represented by formula (1), wherein the amino group is a primary amino group.

7. The aromatic amine compound according to claim 1 or 2, An aromatic amine compound in which the organic group in formula (1) is an aliphatic group having 1 to 6 carbon atoms and having an amino group, or a divalent aromatic group having an amino group.

8. A curing agent using the aromatic amine compound according to claim 1 or 2.

9. Epoxy resin, and 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 a hydrocarbon group having 3 to 18 carbon atoms, and at least one of them has a hydroxyl group.)

10. 10. The epoxy resin composition according to claim 9, an 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.

11. The epoxy resin composition according to claim 9 or 10, An epoxy resin composition, wherein in formula (1), the hydrocarbon group is a linear or branched hydrocarbon group.

12. The epoxy resin composition according to claim 9 or 10, An epoxy resin composition, wherein in formula (1), the hydrocarbon group has a hydroxyl group at its terminal.

13. The epoxy resin composition according to claim 9 or 10, An epoxy resin composition, wherein in formula (1), the hydrocarbon group is a saturated hydrocarbon group.

14. The epoxy resin composition according to claim 9 or 10, An epoxy resin composition represented by formula (1), wherein R1 and R2 each have an amino group.

15. The epoxy resin composition according to claim 9 or 10, An epoxy resin composition, wherein in formula (1), the amino group is a primary amino group.

16. The epoxy resin composition according to claim 9 or 10, An epoxy resin composition, wherein in formula (1), the organic group is an aliphatic group having 1 to 6 carbon atoms and having an amino group, or a divalent aromatic group having an amino group.

17. A method for producing an aromatic amine compound, comprising a reaction step of reacting, in the presence of a basic catalyst, a fluorene having a hydrocarbon group having 3 to 18 carbon atoms and a hydroxyl group and an amine compound, or a fluorene having an amino group bonded to at least one of the 2- and 7-positions of the fluorene skeleton and a compound having a hydrocarbon group having 3 to 18 carbon atoms and a hydroxyl group.

18. The method for producing an aromatic amine compound according to claim 17, The method for producing an aromatic amine compound further comprises a protection step of protecting the hydroxyl group and / or the amino group with an inert group before the reaction step.

19. The method for producing an aromatic amine compound according to claim 18, The method for producing an aromatic amine compound further comprises, after the reaction step, a removal step of removing the inactive group.

20. The method for producing an aromatic amine compound according to claim 17 or 18, The reaction step is carried out by heating at 80 to 180°C.

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

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

Images