Epoxy resin composition, prepreg, and fiber-reinforced composite material

Abstract

A first epoxy resin composition is described, comprising: [A] at least one epoxy resin; [B][B-1] at least two curing agents, comprising at least one first curing agent and [B-2] at least one second curing agent different from the first curing agent; and [C] at least one accelerator, wherein the epoxy resin composition satisfies 5.0>|T1-T2|, and [A], [B], [C], T1, and T2 are as defined. A second epoxy resin composition is described, comprising: [A] at least one epoxy resin; [B][B-1] at least two curing agents, comprising at least one amine compound and at least one organic acid hydrazide compound; and [C][C-1] at least one accelerator, comprising at least one organic phosphorus compound, wherein [A], [B], and [C-1] are as defined. A prepreg, comprising reinforcing fiber bundles impregnated with the first epoxy resin or the second epoxy resin, as well as a fiber-reinforced composite material are also described.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 318,249, filed March 9, 2022, U.S. Provisional Patent Application No. 63 / 168,738, filed March 31, 2021, and U.S. Provisional Patent Application No. 63 / 168,717, filed March 31, 2021, the entire contents of which are all incorporated by reference herein.

[0002] The present invention relates to an epoxy resin composition which can be used for fiber-reinforced composite materials, which has both excellent latency and excellent curability that enables the composition to be cured in a short time, a prepreg formed by impregnating reinforcing fibers with the epoxy resin composition, and a fiber-reinforced composite material containing the epoxy resin composition and reinforcing fibers. [Background technology]

[0003] Composite materials containing reinforcing fibers such as carbon fibers or glass fibers and thermosetting resins such as epoxy resins or phenolic resins have found applications in fields such as aerospace, automobiles, rail vehicles, ships, civil engineering and construction, and sporting goods, because they exhibit very good mechanical properties such as strength and stiffness, heat resistance, and corrosion resistance while being lightweight. For applications requiring high performance, composite materials containing continuous reinforcing fibers are often selected. As reinforcing fibers, carbon fibers exhibit very good specific strength and specific modulus. As matrix resins, thermosetting resins, especially epoxy resins that bond well with carbon fibers, are often selected due to their heat resistance, modulus, chemical resistance, and low cure shrinkage.

[0004] As a curing agent for epoxy resins, aliphatic amine compounds, aromatic amine compounds, acid anhydrides, and imidazole derivatives are often used in combination. In particular, for aerospace applications requiring heat resistance under high humidity conditions, aromatic amine compounds are preferred because they exhibit excellent latency in the resin composition and heat resistance in the cured product.

[0005] However, aromatic amine compounds generally have low reactivity with epoxy resins compared to other curing agents, and molding of the epoxy resin composition typically requires heating for a long period of time at a high curing temperature of nearly 180° C. The low reactivity of the epoxy resin composition with the curing agent undesirably results in high energy costs associated with long molding times.

[0006] In contrast, the ability of composite structures to be cured at low temperatures offers a variety of advantages. In one embodiment, tools such as molds used to shape the composites can be made from lower-cost, low-temperature materials rather than more expensive materials that can withstand higher curing temperatures. Furthermore, curing at relatively low temperatures can desirably prevent the formation of voids. Curing at relatively low temperatures can also be preferred in vacuum bag-only composite processing because of the advantages discussed above. Thus, a technology that allows epoxy resin compositions to be cured at low temperatures and in short periods of time would be highly valuable. However, epoxy resin compositions as matrix resins for use in composites, adhesives, and surfacing films that can be cured at relatively low temperatures while still maintaining good pot life and mechanical properties are under development.

[0007] It is known to use accelerators (catalysts) to accelerate the curing of epoxy resin compositions. 3 ), amine complexes, and boron trichloride (BCl 3) have been used as low temperature curing agents and / or accelerators. Some of these curing agent systems exhibit relatively good stability at room temperature (e.g., tack life of more than about one week) due to either latency or low reactivity, but they all come with drawbacks. For example, some of these curing agent systems undesirably reduce the mechanical properties of the resulting composite, while others undesirably increase the brittleness of the matrix resin, which reduces the toughness of the composite. In another example, the elastic modulus of the matrix resin decreases and / or the hygroscopicity of the matrix resin increases, each of which reduces the hygrothermodynamic performance of the resulting composite. In addition, some of these curing agent systems exhibit too high reactivity, which undesirably shortens the pot life of the matrix resin.

[0008] US Patent Application Publication No. 2010 / 0222461(A1) describes an epoxy resin composition comprising an epoxy resin and a dual cure system of one or more curing agents containing one or more organic acid hydrazide compounds as hydrazine-based curing agents and one or more curing agents containing one or more amine functional groups. The hydrazide-amine cure system can achieve a gelation level or increased cure at a lower temperature for the epoxy composition compared to the amine-based curing agent alone.

[0009] Similarly, US Patent Application Publication No. 2017 / 0362427(A1) describes an epoxy resin composition comprising an epoxy resin, an aromatic amine compound, an organic acid hydrazide compound, and a thermoplastic resin. The composition achieves good curability and latency, and the viscosity of the epoxy resin composition after being kept at 80°C for 2 hours is up to 2.0 times higher than the initial viscosity at 80°C.

[0010] WO 2019 / 219953(A1) describes a curable resin composition comprising an epoxy phenolic resin, a carboxylic acid hydrazide curing agent, and a hydroxy-substituted urone, but does not disclose a combination of the hydrazide, the urone, and a second curing agent different from the hydrazide. The composition achieves good curability as well as latency, and the viscosity of the epoxy resin composition after being held at 80°C for 2 hours is up to 2.0 times higher than the initial viscosity at 80°C. Summary of the Invention [Problem to be solved by the invention]

[0011] In order to solve the above problems, the inventors have discovered that a particular combination of at least one first curing agent, at least one second curing agent different from the first curing agent, and at least one accelerator that accelerates the reaction of the second curing agent with an epoxy resin but does not substantially accelerate the reaction of the first curing agent with an epoxy resin provides very good latency together with very good curability that makes the composition curable in a short time, which makes the composition desirable for the production of fiber reinforced composites, prepregs formed by impregnating reinforcing fibers with the epoxy resin composition, and composites containing the epoxy resin composition and reinforcing fibers. [Means for solving the problem]

[0012] One aspect of the present invention is [A] at least one epoxy resin; [B] at least two curing agents, [B-1] at least one first curing agent; [B-2] at least one second curing agent different from the first curing agent; At least two curing agents, [C] at least one accelerator; The epoxy resin composition according to the present invention comprises: said component [B-1] comprises at least one aromatic amine compound; and said component [B-2] comprises at least one compound selected from the group consisting of 3-hydroxy-2-naphthoic acid hydrazide, 2,6-naphthalenedicarboxylic acid dihydrazide, and isophthalic acid dihydrazide; The component [C] is a phosphine compound 、 phosphonium salts, And, at least one compound selected from the group consisting of ammonium salts; The epoxy resin composition satisfies (I), 5.0>|T 1 -T 2 | (I), During the ceremony, T 1 is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-1], T 2 is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-1], and [C], Extrapolation start temperature T 1 and T 2 is determined by differential scanning calorimetry (DSC) at a heating rate of 10° C. / min using the above mixture in which the equivalent ratio of all active hydrogens in [B-1] or [B-2] to all epoxy groups in [A] is 1.0 and the mass ratio of [C] to [A] is 1:100.

[0013] In one embodiment, the epoxy resin composition further satisfies (II): 5.0≦T 3 -T 4 (II) During the ceremony, T 3 is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-2], T 4 is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-2], and [C], Extrapolation start temperature T 3 and T 4is a mixture in which the equivalent ratio of all active hydrogens in [B-2] to all epoxy groups in [A] is 1.0, and the mass ratio of [C] to [A] is 1:100. 3 and T 4 The mixture is determined by differential scanning calorimetry at a heating rate of 10° C. / min.

[0014] In one embodiment, component [B-2] contains at least one organic acid hydrazide compound.

[0015] In one embodiment, component [C] comprises at least one compound selected from the group consisting of organic phosphine compounds, phosphonium salts, and ammonium salts.

[0016] In one embodiment, component [C] is at least one compound selected from the group consisting of triphenylphosphine, tetraphenylphosphonium bromide, triphenylphosphine triphenylborane, and tetrabutylammonium trifluoromethanesulfonate.

[0017] In one embodiment, component [C] is present in an amount of 0.1 to 10 parts by weight per 100 parts by weight of component [A].

[0018] In one embodiment, component [A] is present in an amount of 100 parts by weight, component [B-2] is present in an amount of 1 to 20 parts by weight, component [C] is present in an amount of 0.1 to 10 parts by weight, and the equivalent ratio of all active hydrogens of components [B-1] and [B-2] to all epoxy groups of component [A] is 0.7 to 1.3.

[0019] Another aspect is [A] at least one epoxy resin; [B] at least two curing agents, [B-1] at least one first curing agent; [B-2] at least one second curing agent different from the first curing agent; At least two curing agents, [C] at least one accelerator; The epoxy resin composition comprises: [B-1] contains at least one amine compound, [B-2] contains at least one organic acid hydrazide compound, [C] is [C-1] At least one Organophosphine compounds or phosphonium salts Including, Component [C-1] promotes the reaction between component [A] and at least one curing agent, Component [A] is present in an amount of 100 parts by mass, component [B-2] is present in an amount of 1 to 20 parts by mass, and component [C-1] is present in an amount of 0.1 to 10 parts by mass; The equivalent ratio of all active hydrogens in components [B-1] and [B-2] to all epoxy groups in component [A] is 0.7 to 1.3.

[0020] In one embodiment, the viscosity (V) of the epoxy resin composition measured after holding at 80° C. for 4 hours 2 The viscosity (V) of the epoxy resin composition was measured after holding it at 80°C for 1 minute. 1 ) to the ratio (V 2 / V 1 ) is less than or equal to 2.5, such as less than or equal to 2.0.

[0021] In one embodiment, component [A] includes at least one epoxy resin having three or more epoxy groups.

[0022] In one embodiment, component [A] comprises at least one compound selected from the group consisting of tetraglycidyldiaminodiphenylmethane, meta- or para-aminophenol epoxy resins, and bisnaphthalene epoxy resins.

[0023] In one embodiment, component [B-1] contains at least one amine compound.

[0024] In one embodiment, component [B-1] comprises at least one aromatic amine compound.

[0025] In one embodiment, component [B-1] includes 3,3'-diaminodiphenyl sulfone and / or 4,4'-diaminodiphenyl sulfone.

[0026] In one embodiment, component [B-2] has at least one aromatic ring structure.

[0027] In one embodiment, component [B-2] includes at least one compound selected from the group consisting of 3-hydroxy-2-naphthoic acid hydrazide, 2,6-naphthalenedicarboxylic acid dihydrazide, and isophthalic acid dihydrazide.

[0028] In one embodiment, the equivalent ratio of all active hydrogens in component [B-1] to all active hydrogens in component [B-2] is 1-10.

[0029] In one embodiment, component [C-1] has a melting point of 220° C. or less, as measured by differential scanning calorimetry at a heating rate of 10° C. / min.

[0030] In one embodiment, the epoxy resin composition satisfies (V) and (VI): 5.0>|T 1 -T 5 | (V), and 2.0>|T 1p -T 5p | (VI), During the ceremony, T 1 is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-1], T 5 is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-1], and [C-1], T 1p is the peak temperature (°C) in the reaction of the mixture of [A] and [B-1], T 5p is the peak temperature (°C) in the reaction of a mixture of [A], [B-1], and [C-1], Extrapolation start temperature T 1 and T 5 , and peak temperature T1p and T 5p is determined by differential scanning calorimetry at a heating rate of 10°C / min using the above mixture in which the equivalent ratio of all active hydrogens of [B-1] or [B-2] to all epoxy groups of [A] is 1.0 and the mass ratio of [C-1] to [A] is 1:100.

[0031] In one embodiment, component [C-1] comprises at least one organophosphine compound.

[0032] In one embodiment, component [C-1] is at least one compound selected from the group consisting of triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(p-methoxyphenyl)phosphine, diphenylcyclohexylphosphine, triphenylphosphine oxide, and triphenylphosphinetriphenylborane.

[0033] In one embodiment, the epoxy resin composition further comprises at least one thermoplastic resin.

[0034] In one embodiment, the thermoplastic resin is present in an amount of 1 to 30 parts by weight per 100 parts by weight of component [A].

[0035] Another aspect relates to a prepreg comprising reinforcing fiber bundles impregnated with the epoxy resin composition disclosed herein.

[0036] In one embodiment, a fiber reinforced composite material is obtained by curing the prepregs disclosed herein.

[0037] In another embodiment, a fiber reinforced composite material comprises an epoxy resin cured article obtained by curing a mixture comprising the epoxy resin composition disclosed herein and reinforcing fibers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes.

[0039] The articles "a" and "an" are used herein to mean one or more than one (i.e., at least one) of the grammatical object of the article. For example, "polymeric resin" means one polymeric resin or two or more polymeric resins. Any range cited herein is inclusive of the limits. The terms "substantially" and "about" are used to describe and account for small variations. For example, they can mean that an amount or quantity varies from the stated value within ±5%.

[0040] References throughout this specification to "one embodiment" or "one embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the appearances of the phrase "in one embodiment" or "in one embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0041] Unless otherwise specified, "room temperature" as used herein means a temperature of 23°C.

[0042] As used herein, the term "fiber reinforced composite material" may be used interchangeably with the terms "fiber reinforced composite," "fiber reinforced polymeric material," "fiber reinforced plastic material," and "fiber reinforced plastic."

[0043] The present invention relates to an epoxy resin composition which combines excellent latency, making it useful for producing fiber-reinforced composite materials, with excellent curability, making the composition curable within a short period of time; a prepreg formed by impregnating reinforcing fibers with the epoxy resin composition; and a reinforced composite material comprising the epoxy resin composition and reinforcing fibers.

[0044] According to the present disclosure, a prepreg can be obtained that has excellent curability and excellent latency to provide a fiber reinforced composite material in a short time. Furthermore, by using the prepreg of the present disclosure, a carbon fiber reinforced composite material can be obtained by curing the prepreg without causing any significant problems in mechanical properties.

[0045] The epoxy resin composition, prepreg, and carbon fiber reinforced composite material of the present disclosure are described in detail below.

[0046] The present inventors have discovered that the above-mentioned deficiencies associated with the prior art can be overcome by the use of an epoxy resin composition for fiber reinforced composite applications, the epoxy resin composition comprising: [A] at least one epoxy resin; [B] at least two curing agents, [B-1] at least one first curing agent; [B-2] at least one second curing agent different from the first curing agent; At least two curing agents, [C] at least one accelerator; The component [B-1] comprises at least one aromatic amine compound, and the component [B-2] comprises at least one compound selected from the group consisting of 3-hydroxy-2-naphthoic acid hydrazide, 2,6-naphthalenedicarboxylic acid dihydrazide, and isophthalic acid dihydrazide, The component [C] is a phosphine compound 、 phosphonium salts, And, at least one compound selected from the group consisting of ammonium salts; The epoxy resin composition satisfies (I) and (II), 5.0>|T 1 -T 2 | (I) 5.0≦T 3 -T 4 (II) During the ceremony, T 1 is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-1], T 2 is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-1], and [C], T 3 is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-2], T 4 is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-2], and [C], Extrapolation start temperature T 1 , T 2 , T 3 , and T 4 is determined by differential scanning calorimetry at a heating rate of 10° C. / min using the above mixture in which the equivalent ratio of all active hydrogens in [B-1] or [B-2] to all epoxy groups in [A] is 1.0 and the mass ratio of [C] to [A] is 1:100.

[0047] Hereinafter, various non-limiting embodiments of an exemplary epoxy resin composition, a prepreg, and a fiber-reinforced composite material obtained by curing the prepreg of the present invention will be described in more detail. One aspect of the present invention is an epoxy resin composition comprising at least one epoxy resin [A], at least two different curing agents [B], and at least one accelerator [C], and the epoxy resin composition is characterized in that it satisfies the above-mentioned relationships (I) and (II). First, the epoxy resin [A] will be described.

[0048] [A] Epoxy resin There are no particular limitations or restrictions on the component [A] used in the present invention, and it is sufficient that it is an epoxy resin having one or more glycidyl groups in the molecule.

[0049] In an embodiment, component [A] has two or more glycidyl groups in the molecule, such as three or more glycidyl groups, such as four or more glycidyl groups, such as five or more glycidyl groups, such as six or more glycidyl groups, such as seven or more glycidyl groups. In an embodiment, component [A] has 2 to 10 glycidyl groups, such as 2 to 8 glycidyl groups, such as 2 to 5 glycidyl groups, such as 2, 3, 4, 5, 6, 7, 8, 9, or 10 glycidyl groups. In the case of an epoxy resin having less than two glycidyl groups in the molecule, the glass transition temperature of the cured epoxy resin composition obtained by curing the epoxy resin composition may be low.

[0050] Non-limiting examples of component [A] include bisphenol type epoxy resins (such as bisphenol A type epoxy, bisphenol F type epoxy, bisphenol AD ​​type epoxy, and bisphenol S type epoxy), brominated epoxy resins (such as tetrabromobisphenol A diglycidyl ether), novolac type epoxy resins (such as epoxy resins having a biphenyl skeleton, epoxy resins having a naphthalene skeleton, epoxy resins having a dicyclopentadiene skeleton, phenol novolac type epoxy resins, and cresol novolac type epoxy resins), glycidylamine type epoxy resins (N,N,O-tetramethylphenyl ether, etc.), and the like. triglycidyl-m-aminophenol, N,N,O-triglycidyl-p-aminophenol, N,N,O-triglycidyl-4-amino-3-methylphenol, N,N,N',N'-tetraglycidyl-4,4'-methylenedianiline, N,N,N',N'-tetraglycidyl-2,2'-diethyl-4,4'-methylenedianiline, N,N,N',N'-tetraglycidyl-m-xylylenediamine, N,N-diglycidylaniline, and N,N-diglycidyl-o-toluidine, as well as other resorcinol diglycidyl ethers and triglycidyl isocyanurates. In particular, epoxy resins having three or more glycidyl groups in the molecule can form cured epoxy resin compositions with high glass transition temperatures and moduli, and are therefore suitable for use in the aerospace industry.

[0051] These epoxy resins may be used alone or in suitable mixtures so that the cured epoxy resin composition and fiber reinforced composite material exhibit the intended mechanical properties and heat resistance. Combining an epoxy resin that exhibits flowability at an appropriate temperature with an epoxy resin that does not exhibit flowability at an appropriate temperature is effective in controlling the flowability of the matrix resin during thermal curing of the resulting prepreg. For example, if the matrix resin has too high a flowability before the start of gelation in the thermal curing process, distortion of the reinforcing fiber arrangement may occur or the matrix resin may flow out of the system, which may cause the fiber mass content to fall outside the specified range, resulting in a carbon fiber reinforced composite material with reduced mechanical properties. Combining multiple epoxy resins that exhibit different viscoelastic behavior is effective in obtaining a prepreg with an appropriate level of tack and drapeability.

[0052] The epoxy resin composition according to the present invention may contain a resin containing only one epoxy group in the molecule (monopoxy resin) and an alicyclic epoxy resin, so long as this does not result in a significant decrease in heat resistance or mechanical properties.

[0053] In a specific embodiment of the present invention, component [A] includes an at least difunctional bisnaphthalene type epoxy resin represented by the following general formula (A-1) and an at least trifunctional epoxy resin other than the above bisnaphthalene type epoxy resin. The adoption of such a method in the selection of the epoxy resin is helpful in obtaining an epoxy resin composition capable of forming a cured epoxy resin composition exhibiting high heat resistance under hygroscopic conditions. [ka]

[0054] In the general formula (A-1), X represents an alkylene group having 1 to 8 carbon atoms (e.g., 1 to 6 carbon atoms, e.g., 1 to 4 carbon atoms) or a group represented by the following general formula (A-2), R 1 ~R 5each independently represents a group represented by the following general formula (A-3) or (A-4), a hydrogen atom, a halogen atom (e.g., one or more of F, Cl, Br, and I), a phenyl group, or an alkyl group having 1 to 4 carbon atoms (e.g., 1 to 3 carbon atoms, 1 to 2 carbon atoms, etc.), R 1 ~R 4 may be bonded to one or both of the two naphthalene rings, and R 5 may be bonded to any vacant position of the benzene ring, R 1 ~R 5 are represented by the following general formula (A-3), or alternatively, at least one group represented by general formula (A-3) and at least one group represented by general formula (A-4) are represented by R 1 ~R 5 The remaining substituents R 1 ~R 5 may be the same or different from each other. With respect to (A-3) and (A-4), the oxiranylmethyl group and the oxirane ring portion of the glycidyl group are also referred to herein as a glycidyl group or a glycidyl functional group, and an epoxy group or an epoxy functional group, respectively. [ka] [ka] [ka]

[0055] Any method may be used to prepare the epoxy group represented by general formula (A-1). In an exemplary embodiment, (A-1) may be prepared through the reaction of hydroxynaphthalene with epihalohydrin.

[0056] In one embodiment, the bisnaphthalene epoxy resin preferably contains 2 to 10 glycidyl groups, more preferably 2 to 5. If too many glycidyl groups are present, the resulting cured epoxy resin composition may in some cases be brittle enough that its impact resistance is reduced.

[0057] In a specific embodiment, the content of the bisnaphthalene type epoxy resin is preferably 10 to 50 parts by mass, more preferably 20 to 40 parts by mass, and particularly preferably 25 to 30 parts by mass, relative to 100 parts by mass of the epoxy resin in the epoxy resin composition. By making the content 10 parts by mass or more, it becomes possible to produce a cured epoxy resin composition and a fiber reinforced composite material having high heat resistance. On the other hand, by making the content 50 parts by mass or less, it becomes possible to produce a cured epoxy resin composition and a fiber reinforced composite material having high elongation.

[0058] Specific examples of bisnaphthalenes include, but are not limited to, EPICLON® HP-4700, EPICLON® HP-4710, EPICLON® HP-4770, EPICLON® EXA-4701, and EPICLON® EXA-4750 (all manufactured by DIC Corporation).

[0059] In one embodiment, the at least trifunctional epoxy resin is an epoxy resin other than a bisnaphthalene type epoxy resin that contains three or more epoxy groups in the molecule. Examples of the at least trifunctional epoxy resin include a glycidylamine type epoxy resin, a glycidyl ether type epoxy resin, and an aminophenol type epoxy resin.

[0060] In another embodiment, the epoxy resin that is at least trifunctional preferably contains 3 to 7 glycidyl groups, more preferably 3 to 4. If too many glycidyl groups are present, the resulting cured epoxy resin composition may in some cases be brittle enough that impact resistance is reduced.

[0061] Examples of glycidylamine-type epoxy resins that are at least trifunctional include diaminodiphenylmethane-type epoxy resins, diaminodiphenylsulfone-type epoxy resins, metaxylenediamine-type epoxy resins, 1,3-bisaminomethylcyclohexane-type epoxy resins, and isocyanuric acid-type epoxy resins.

[0062] Examples of glycidyl ether type epoxy resins that are at least trifunctional include phenol novolac type epoxy resins, orthocresol novolac type epoxy resins, tris-hydroxyphenylmethane type epoxy resins, and tetraphenylolethane type epoxy resins.

[0063] Furthermore, in addition to the above-mentioned at least trifunctional glycidyl amine-type epoxy resins and at least trifunctional glycidyl ether-type epoxy resins, other suitable at least trifunctional epoxy resins include aminophenol-type epoxy resins, which contain both glycidyl amine groups and glycidyl ether groups in the molecule.

[0064] Among the above-mentioned at least trifunctional epoxy resins, diaminodiphenylmethane type epoxy resins and aminophenol type epoxy resins are particularly preferred due to their good balance among the desired physical properties.

[0065] If the content of the at least trifunctional epoxy resin is too low, the heat resistance of the fiber-reinforced composite material may decrease, while if the content is too high, the crosslink density may increase, which may result in a brittle material, resulting in a cured epoxy resin composition and a resulting fiber-reinforced composite material with reduced impact resistance and strength. Therefore, the content of the at least trifunctional epoxy resin is preferably 20 to 80 parts by mass, more preferably 30 to 70 parts by mass, and particularly preferably 40 to 60 parts by mass, relative to 100 parts by mass of the epoxy resin in the epoxy resin composition.

[0066] Specific examples of epoxy resins that are at least trifunctional include, but are not limited to, SUMI-EPOXY® ELM434, SUMI-EPOXY® ELM434VL (all manufactured by Sumitomo Chemical Co., Ltd.), ARALDITE® MY720, ARALDITE® MY721, ARALDITE® MY9512, ARALDITE® MY9655, and ARALDITE® MY9663 (all manufactured by Huntsman). Corporation), Epotohto® YH-434 (Nippon Steel Sumikin Chemical Co., Ltd.), SUMI-EPOXY® ELM120 and SUMI-EPOXY® ELM100 (both manufactured by Sumitomo Chemical Co., Ltd.), jER™ 630 (manufactured by Mitsubishi Chemical Corporation), ARALDITE® MY0500, ARALDITE® MY0510, and ARALDITE® MY0600 (all manufactured by Huntsman Corporation).

[0067] A specific example of a meta-xylylenediamine type epoxy resin is TETRAD-X (manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0068] A specific example of the 1,3-bisaminomethylcyclohexane type epoxy resin is TETRAD-C (manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0069] A specific example of an isocyanurate type epoxy resin is TEPIC (registered trademark)-P (manufactured by Nissan Chemical Industries, Ltd.).

[0070] Specific examples of phenol novolac type epoxy resins include DEN (trademark) 431 and DEN (trademark) 438 (both manufactured by The Dow Chemical Company), and jER (trademark) 152 (manufactured by Mitsubishi Chemical Corporation).

[0071] Specific examples of orthocresol novolac type epoxy resins include EOCN-1020 (manufactured by Nippon Kayaku Co., Ltd.) and EPICLON (registered trademark) N-660 (manufactured by DIC Corporation).

[0072] A specific example of a tris-hydroxyphenylmethane type epoxy resin is Tactix® 742 (manufactured by Huntsman Corporation).

[0073] A specific example of the tetraphenylolethane type epoxy resin is jER (trademark) 1031S (manufactured by Mitsubishi Chemical Corporation).

[0074] A specific example of a dicyclopentadiene type epoxy resin is EPICLON (registered trademark) HP-7200 (manufactured by DIC Corporation).

[0075] A specific example of a resorcinol type epoxy resin is Denacol (trademark) EX-201 (manufactured by Nagase ChemteX Corporation).

[0076] A specific example of the urethane-modified epoxy resin is AER4152 (manufactured by Asahi Kasei E-materials Corporation).

[0077] A specific example of the phenol aralkyl type epoxy resin is NC-3000 (manufactured by Nippon Kayaku Co., Ltd.).

[0078] In certain embodiments of the present invention, component [A] comprises an epoxy resin having one or more ring structures containing four or more ring atoms (such as C, N, O, and / or S) and at least one glycidyl amine group or glycidyl ether group directly bonded to the ring structure, and the epoxy resin is at least trifunctional. Adopting such an approach is useful for obtaining an epoxy resin composition capable of forming a fiber-reinforced composite material having high tensile strength at low temperature. In this specification, the term "having one or more ring structures containing four or more ring members" means either containing one or more monocyclic ring structures each having four or more ring atoms, such as cyclohexane, benzene, and pyridine, or containing at least one fused ring structure having four or more ring atoms, such as phthalimide, naphthalene, and carbazole.

[0079] The glycidyl amine group or glycidyl ether group directly bonded to a ring structure in the epoxy resin described above has a structure in which the nitrogen (N) atom of the glycidyl amine group or the oxygen (O) atom of the glycidyl ether group is bonded to a ring structure of benzene, phthalimide, or the like. When the epoxy resin contains a glycidyl amine group, it is monofunctional or difunctional, or when the epoxy resin contains a glycidyl ether group, it is monofunctional.

[0080] In one embodiment, the epoxy resin may be a difunctional epoxy resin having a structure represented by the general formula (A-5) shown below. [ka]

[0081] In general formula (A-5), R 6 and R 7are each at least one independently selected from the group consisting of a hydrogen atom (H), an aliphatic hydrocarbon group having 1 to 4 carbon atoms (e.g., 1 to 2), an alicyclic hydrocarbon group having 3 to 6 carbon atoms (e.g., 5 to 6), an aromatic hydrocarbon group having 6 to 10 carbon atoms (e.g., 6), a halogen atom (e.g., F, Cl, Br, or I), an acyl group, a trifluoromethyl group, and a nitro group. Here, n is an integer of 0 to 4, and m is an integer of 0 to 5. When n or m is an integer of 2 or more, the substituent R 6 and R 7 may be the same or different. X is -O-, -S-, -CO-, -C(=O)O-, or -SO 2 - represents one selected from the group consisting of:

[0082] When the content of the epoxy resin having one or more ring structures containing 4 or more ring atoms and at least one glycidylamine group or glycidylether group directly bonded to the ring structure is appropriate, both the tensile strength and heat resistance of the obtained fiber reinforced composite material can be favorably affected. Therefore, the content of the epoxy resin is preferably 5 to 60 parts by mass based on 100 parts by mass of all epoxy resins present in the epoxy resin composition.

[0083] In one embodiment, the use of a monofunctional epoxy resin leads to a fiber reinforced composite material exhibiting higher tensile strength, while the use of a difunctional epoxy resin leads to a fiber reinforced composite material exhibiting higher heat resistance.

[0084] When a monofunctional epoxy resin is used, the content of the epoxy resin is preferably 10 to 30 parts by mass, more preferably 15 to 25 parts by mass, based on 100 parts by mass of all epoxy resins present in the epoxy resin composition. When a bifunctional epoxy resin is used, the content of the epoxy resin is preferably 10 to 40 parts by mass, more preferably 20 to 30 parts by mass, based on 100 parts by mass of all epoxy resins present in the epoxy resin composition.

[0085] Examples of monofunctional epoxy resins include, but are not limited to, glycidyl phthalimide, glycidyl-1,8-naphthalimide, glycidyl carbazole, glycidyl-3,6-dibromocarbazole, glycidyl indole, glycidyl-4-acetoxyindole, glycidyl-3-methylindole, glycidyl-3-acetylindole, glycidyl-5-methoxy-2-methylindole, o-phenylphenyl glycidyl ether, p-phenylphenyl glycidyl ether, p-(3-methylphenyl)phenyl glycidyl ether, 2,6-dibenzylphenyl glycidyl ether, 2-benzylphenyl glycidyl ether, 2,6-diphenylphenyl glycidyl ether, 4-α-cumylphenyl glycidyl ether, o-phenoxyphenyl glycidyl ether, and p-phenoxyphenyl glycidyl ether.

[0086] Examples of difunctional epoxy resins include, but are not limited to, N,N-diglycidyl-4-phenoxyaniline, N,N-diglycidyl-4-(4-methylphenoxy)aniline, N,N-diglycidyl-4-(4-tert-butylphenoxy)aniline, and N,N-diglycidyl-4-(4-phenoxyphenoxy)aniline. In many cases, these epoxy resins can be prepared by adding epichlorohydrin to a phenoxyaniline derivative and cyclizing with an alkali compound. Since the viscosity increases with increasing molecular weight, the epoxy resins represented by the general formula (A-5), in which R 6 and R 7 In view of handleability, N,N-diglycidyl-4-phenoxyaniline in which both are hydrogen atoms is particularly preferred.

[0087] Examples of phenoxyaniline derivatives include, but are not limited to, 4-phenoxyaniline, 4-(4-methylphenoxy)aniline, 4-(3-methylphenoxy)aniline, 4-(2-methylphenoxy)aniline, 4-(4-ethylphenoxy)aniline, 4-(3-ethylphenoxy)aniline, 4-(2-ethylphenoxy)aniline, 4-(4-propylphenoxy)aniline, 4-(4-tert-butylphenoxy)aniline, 4-(4-cyclohexylphenoxy)aniline, 4-(3-cyclohexylphenoxy)aniline, 4-(2-cyclohexylphenoxy)aniline, 4-(4-methoxyphenoxy)aniline, 4-(3-methoxyphenoxy)aniline, 4-(2-methoxyphenoxy)aniline, 4-(3-phenoxyphenoxy)aniline, 4-(4-phenoxyphenoxy)aniline, 4-[4-(trifluoromethyl)phenoxy]aniline, 4-[3- (trifluoromethyl)phenoxy]aniline, 4-[2-(trifluoromethyl)phenoxy]aniline, 4-(2-naphthyloxyphenoxy)aniline, 4-(1-naphthyloxyphenoxy)aniline, 4-[(1,1'-biphenyl-4-yl)oxy]aniline, 4-(4-nitrophenoxy)aniline, 4-(3-nitrophenoxy)aniline, 4-(2-nitrophenoxy)aniline, 3-nitro-4-aminophenylphenyl ether ter, 2-nitro-4-(4-nitrophenoxy)aniline, 4-(2,4-dinitrophenoxy)aniline, 3-nitro-4-phenoxyaniline, 4-(2-chlorophenoxy)aniline, 4-(3-chlorophenoxy)aniline, 4-(4-chlorophenoxy)aniline, 4-(2,4-dichlorophenoxy)aniline, 3-chloro-4-(4-chlorophenoxy)aniline, and 4-(4-chloro-3-tolyloxy)aniline.

[0088] Specific examples of monofunctional epoxy resins include, but are not limited to, DENACOL (trademark) EX-731 (glycidyl phthalimide, manufactured by Nagase ChemteX Corporation) and OPP-G (o-phenylphenyl glycidyl ether, manufactured by Sanko Co., Ltd.), and specific examples of difunctional epoxy resins include GAN (N-diglycidylaniline, manufactured by Nippon Kayaku Co., Ltd.) and TOREP (registered trademark) A-204E (diglycidyl-p-phenoxyaniline, manufactured by Toray Fine Chemicals Co., Ltd.).

[0089] In a specific embodiment of the present invention, component [A] includes either a meta- or para-aminophenol type epoxy resin, or a glycidyl ether type epoxy resin or a glycidyl amine type epoxy resin having two or more glycidyl groups in the molecule other than the meta- or para-aminophenol type epoxy resin. The inclusion of such an epoxy resin is useful for obtaining an epoxy resin composition capable of forming a cured epoxy resin composition exhibiting high heat resistance.

[0090] In one embodiment, for the purpose of producing a cured epoxy resin composition exhibiting excellent toughness, elongation, and heat resistance, the content of the meta- or para-aminophenol type epoxy resin is preferably 10 to 50 parts by weight, more preferably 15 to 40 parts by weight, and even more preferably 20 to 30 parts by weight, based on 100 parts by weight of all epoxy resins present in the epoxy resin composition.

[0091] In one embodiment, the meta- or para-aminophenol type epoxy resin may be at least one selected from the group consisting of epoxy resins having a structure represented by the following general formula (A-6) and derivatives thereof. [ka]

[0092] In general formula (A-6), R 8 and R 9represents at least one selected from the group consisting of a hydrogen atom, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 4 or less carbon atoms (e.g., 3, 2, or 1), and a halogen atom (e.g., F, Cl, Br, or I).

[0093] R in general formula (A-6) 8 and R 9 When the structure is three-dimensionally too large, the viscosity of the epoxy resin composition becomes very high, which may result in poor handleability, and the compatibility between the meta- or para-aminophenol type epoxy resin and other components of the epoxy resin composition may decrease, which may result in poor desired mechanical properties of the fiber-reinforced composite material containing the epoxy resin composition.

[0094] Specific examples of meta- or para-aminophenol type epoxy resins include, but are not limited to, triglycidyl-m-aminophenol, triglycidyl-p-aminophenol, and derivatives and isomers thereof.

[0095] In particular, R 8 and R 9 Each of R is preferably a hydrogen atom from the viewpoint of compatibility with other epoxy resins, and more preferably is triglycidyl-m-aminophenol or triglycidyl-p-aminophenol for the purpose of improving the elastic modulus and heat resistance of the resulting fiber-reinforced composite material. Triglycidyl-meta-aminophenol can provide a high elastic modulus, and triglycidyl-p-aminophenol can provide high heat resistance. From the viewpoint of flame retardancy, R 8 and / or R 9 is also preferably substituted with halogen atoms such as Cl and Br.

[0096] Specific examples of meta- or para-aminophenol type epoxy resins include, but are not limited to, SUMI-EPOXY® ELM120 and SUMI-EPOXY® ELM100 (both manufactured by Sumitomo Chemical Co., Ltd.), jER™ 630 (manufactured by Mitsubishi Chemical Corporation), and ARALDITE® MY0500, ARALDITE® MY0510, ARALDITE® MY0600, and ARALDITE® MY0610 (all manufactured by Huntsman Corporation).

[0097] Non-limiting examples of glycidyl ether type epoxy resins and glycidyl amine type epoxy resins having two or more glycidyl groups in the molecule other than meta- or para-aminophenol type epoxy resins include bisphenol type epoxy resins (such as bisphenol A type epoxy, bisphenol F type epoxy, bisphenol AD ​​type epoxy, and bisphenol S type epoxy), brominated bisphenol type epoxy resins (such as tetrabromobisphenol A diglycidyl ether), and others include alicyclic epoxy resins, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenylether, xylenediamine, structural isomers thereof, and compounds produced by glycidylating amino groups in derivatives containing halogen atoms or alkyl substituents having 3 or less carbon atoms used as precursors. Examples of such glycidyl amine type epoxy resins include, but are not limited to, tetraglycidyldiaminodiphenylmethane, glycidyl compounds of xylenediamine, tetraglycidyldiaminodiphenylsulfone, and tetraglycidyldiaminodiphenylether.

[0098] In one embodiment, low viscosity liquid bisphenol A and bisphenol F type epoxies are preferably used in combination with other epoxy resins.

[0099] In another embodiment, solid bisphenol A type epoxies form lower crosslink density structures with lower heat resistance but higher toughness compared to liquid bisphenol A type epoxies, and therefore are used in combination with glycidyl amine type epoxy resins, liquid bisphenol A type epoxies, or bisphenol F type epoxies.

[0100] Specific examples of bisphenol A type epoxies include, but are not limited to, jER™ 825, jER™ 827, jER™ 828, jER™ 834, jER™ 1001, jER™ 1004, jER™ 1004AF, and jER™ 1007 (all manufactured by Mitsubishi Chemical Corporation), EPICLON® 850 (manufactured by DIC Corporation), Epotohto® YD-128 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and DER™ 331 and DER™ 332 (both manufactured by The Dow Chemical Company).

[0101] Specific examples of bisphenol F type epoxies include, but are not limited to, jER™ 806, jER™ 807, jER™ 1750, jER™ 4004P, and jER™ 4005P (all manufactured by Mitsubishi Chemical Corporation), EPICLON® 830 (manufactured by DIC Corporation), and Epotohto® YDF-170 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.).

[0102] Specific examples of glycidylamine type epoxy resins include, but are not limited to, SUMI-EPOXY (registered trademark) ELM434, SUMI-EPOXY (registered trademark) ELM434VL (all manufactured by Sumitomo Chemical Co., Ltd.), ARALDITE (registered trademark) MY720, ARALDITE (registered trademark) MY721, ARALDITE (registered trademark) MY9512, ARALDITE (registered trademark) MY9655, and ARALDITE (registered trademark) MY9663 (all manufactured by Huntsman Corporation), and Epotohto (registered trademark) YH-434 (manufactured by Nippon Steel Sumikin Chemical Co., Ltd.).

[0103] When a meta- or para-aminophenol type epoxy resin is used in combination with either a glycidyl ether type epoxy resin or a glycidyl amine type epoxy resin having two or more glycidyl groups in the molecule, if the content of the glycidyl ether type epoxy resin or the glycidyl amine type epoxy resin is low, the mechanical properties of the fiber reinforced composite material containing such an epoxy resin may be negatively affected, while if the content is too high, if a bisphenol type epoxy resin is used, the heat resistance may be negatively affected, or if a glycidyl amine type epoxy resin is used, the toughness may be negatively affected.

[0104] As described above, from the viewpoints of heat resistance and control of resin viscosity, and further from the viewpoints of resin elongation and toughness, in one embodiment, the glycidyl ether type epoxy resin and / or the glycidyl amine type epoxy resin is present in an amount of preferably 50 to 90 parts by mass, more preferably 55 to 85 parts by mass, and particularly preferably 60 to 80 parts by mass, per 100 parts by mass of all epoxy resins present in the epoxy resin composition.

[0105] In one embodiment, component [A] includes, as an epoxy resin, a ladder-type silsesquioxane compound containing an epoxy ring.

[0106] In another embodiment, the structure of the ladder-type silsesquioxane compound containing an epoxy ring may be selected from silsesquioxanes and derivatives thereof represented by the following general formula (A-7): Blending these ladder-type silsesquioxanes in an epoxy resin composition helps to improve flame retardancy and heat resistance. [ka]

[0107] In the ladder-type silsesquioxane compound containing an epoxy ring structure, the epoxy ring group is represented by the substituent R 10The substituent R in the general formula (A-7) accounts for 50 to 100 mol %, preferably 60 to 100 mol %. 10 When the proportion of epoxy ring groups present as is controlled within this range, the epoxy resin composition exhibits a suitable viscosity for improved handling and moldability, which may result in a fiber-reinforced composite material exhibiting high levels of flame retardancy, heat resistance, and mechanical properties. The proportion (mol %) of epoxy ring groups can be calculated as follows. (Amount of epoxy groups in ladder-type silsesquioxane (mol)) / (Total amount of substituents in ladder-type silsesquioxane (mol))×100

[0108] The proportion of epoxy ring groups in the ladder-type silsesquioxane can also be determined by organic elemental analysis of the epoxy resin composition, ICP-MS (inductively coupled plasma mass spectrometry), or the like.

[0109] In one embodiment, the substituent R 10 Examples of the alkyl group include glycidoxyalkyl groups having 4 or less carbon atoms, preferably 3 or less carbon atoms, such as β-glycidoxyethyl group, γ-glycidoxypropyl group, and γ-glycidoxybutyl group; and alkyl groups having 5 to 8 carbon atoms and substituted with a cycloalkyl group containing an oxirane group, such as glycidyl group, β-(3,4-epoxycyclohexyl)ethyl group, γ-(3,4-epoxycyclohexyl)propyl group, β-(3,4-epoxycycloheptyl)ethyl group, β-(3,4-epoxycyclohexyl)propyl group, β-(3,4-epoxycyclohexyl)butyl group, and β-(3,4-epoxycyclohexyl)pentyl group, in which alkyl groups having 3 or less carbon atoms and substituted with a cycloalkyl group containing an oxirane group, having 5 to 8 carbon atoms, are preferred. In particular, β-glycidoxyethyl group, γ-glycidoxypropyl group, and β-(3,4-epoxycyclohexyl)ethyl group are preferred.

[0110] In another embodiment, the substituent R in the general formula (A-7) does not contain an epoxy ring group. 10Examples of the alkyl group include a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (e.g., 1 to 8, e.g., 1 to 6, e.g., 1 to 3), and an alkoxy group having 1 to 10 carbon atoms (e.g., 1 to 8, e.g., 1 to 6, e.g., 1 to 3). Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, and an isobutyl group. Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

[0111] The ladder-type silsesquioxane used in the present invention preferably has a weight average molecular weight of 1,500 to 30,000, more preferably 1,500 to 15,000, and particularly preferably 2,000 to 8,000. By using a ladder-type silsesquioxane having a weight average molecular weight within this range, it is possible to, for example, realize sufficient heat resistance and elongation, improve the compatibility between the ladder-type silsesquioxane and other epoxy resins, and improve the impregnation of reinforcing fibers with a matrix resin. The weight average molecular weight described in this specification is a molecular weight based on polystyrene as measured by GPC (gel permeation chromatography).

[0112] A specific example of the ladder-type silsesquioxane containing an epoxy ring group is SE-01GM (manufactured by Nagase ChemteX Corporation).

[0113] The addition of the ladder-type silsesquioxane compound to the epoxy resin composition used for the present invention results in a fiber-reinforced composite material having high levels of flame retardancy, heat resistance, and mechanical properties, where the ladder-type silsesquioxane is present in an amount of 1 to 40 parts by weight, preferably 5 to 30 parts by weight, and more preferably 10 to 20 parts by weight, based on the total amount of the ladder-type silsesquioxane compound and all other epoxy resins in the epoxy resin composition considered to be 100 parts by weight.

[0114] [B] Hardener The selection of the curing agent used as component [B] in the present invention is determined based on the T defined in (I) and (II) described herein.1 , T 2 , T 3 , and T 4 As long as the relationship between is satisfied, the present invention is not limited to any particular curing agent and may vary depending on the requirements of the application. In general, the first curing agent [B-1] and the second curing agent [B-2] different from the first curing agent [B-1] may be selected from, for example, but not limited to, amine compounds, amidoamines, anhydrides, carbodiimides, dicyandiamides, organic acid hydrazide compounds, polyamides, polyamines, phenols, polyesters, polyisocyanates, polymercaptans, substituted guanidines, urea formaldehyde, and melamine resins, and mixtures thereof.

[0115] In a specific embodiment, the first curing agent [B-1] is preferably an aromatic amine compound having 1 to 4 phenyl groups in the molecule for the purpose of improving heat resistance and mechanical properties. Furthermore, since a flexible molecular skeleton can contribute to increasing the elastic modulus of the resin and improving the mechanical properties, the first curing agent is preferably an aromatic amine compound in which at least one phenyl group present in the skeleton has an amino group at the ortho or meta position.

[0116] In another embodiment, an aromatic amine compound in which two or more phenyl groups have amino groups at the para-position is preferred for the purpose of improving heat resistance.

[0117] Examples of such aromatic amine compounds include, but are not limited to, meta-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, meta-xylylenediamine, (para-phenylenemethylene)dianiline, various derivatives thereof such as alkyl substituted, and various isomers with amino groups at different positions. In particular, for making materials suitable for spacecraft and aircraft, 4,4'-diaminodiphenylsulfone or 3,3'-diaminodiphenylsulfone is preferred because these compounds provide cured products that exhibit high heat resistance and elastic modulus, but do not suffer significantly from a decrease in linear expansion coefficient or a decrease in heat resistance due to moisture absorption. The aromatic amine compounds may be used alone or in combination of two or more. When mixed with other components, they may be in the form of powder or liquid, or powdered and liquid aromatic amine compounds may be mixed together.

[0118] Specific examples of suitable aromatic amine compounds include, but are not limited to, SEIKACURE-S (manufactured by Seika Corporation), ARADUR® 976-1, ARADUR® 9664-1, ARADUR® 9719-1 (all manufactured by Huntsman Corporation), 3,3'-DAS (manufactured by Mitsubishi Chemical Corporation), LONZACURE® M-DIPA, and LONZACURE® M-MIPA (all manufactured by Lonza).

[0119] In a particular embodiment, the secondary curing agent [B-2] is preferably an organic acid hydrazide compound for the purpose of achieving a balance between the latency and reactivity of the epoxy resin composition.

[0120] In a particular embodiment, the organic acid hydrazide compound preferably has at least one aromatic ring structure in the molecule for the purpose of improving heat resistance and mechanical properties.

[0121] Non-limiting examples of organic acid hydrazide compounds include carbohydrazide, isophthalic dihydrazide (IDH), phthalic dihydrazide, terephthalic dihydrazide, adipic dihydrazide (ADH), dodecanedioic dihydrazide (DDH), 3-hydroxy-2-naphthoic hydrazide, 2,6-naphthalenedicarboxylic dihydrazide (NDH), 1,2,3-benzenetricarboxylic trihydrazide, aromatic monohydrazide, benzoic hydrazide, aliphatic monohydrazide, aliphatic dihydrazide, sebacic dihydrazide, aliphatic trihydrazide, aliphatic tetrahydrazide, aromatic monohydrazide, aromatic dihydrazide, aromatic trihydrazide, and aromatic tetrahydrazide.

[0122] Specific examples of organic acid hydrazide compounds include, but are not limited to, IDH, 3-hydroxy-2-naphthoic acid hydrazide (all manufactured by Otsuka Chemical Co., Ltd.), Technicure (registered trademark) ADH, Technicure (registered trademark) DDH-S (all manufactured by A&C Catalysts, Inc.), and 2,6-naphthalenedicarboxylic acid dihydrazide (manufactured by Japan Finechem Co., Ltd.).

[0123] In another embodiment, the melting point of the organic acid hydrazide compound in the present invention may be 185° C. or higher, such as 190° C. or higher, such as 195° C. or higher, such as 200° C. or higher, such as 205° C. or higher, such as 210° C. or higher, such as 215° C. or higher, and such as 220° C. or higher.

[0124] In one embodiment, component [B-2] is preferably in the form of particles that are insoluble in component [A] for the purpose of improving thermal stability. Since component [B-2] is dispersed in component [A] in an insoluble state, the curing reaction does not proceed significantly until component [B-2] is dissolved by heating. When the epoxy resin composition is heated to a certain temperature or higher, component [B-2] dissolves and initiates a curing reaction with component [A] together with component [B-1]. The average particle size of component [B-2] is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. By setting the average particle size of component [B-2] to 100 μm or less, the dissolution of component [B-2] during epoxy resin curing is promoted, and thus the curability of the epoxy resin composition is improved. Furthermore, by setting the average particle size of component [B-2] to 100 μm or less, it is possible to suppress any deterioration in the desired mechanical properties of the resin cured product caused by component [B-2] remaining undissolved. Furthermore, the average particle size of component [B-2] is preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more. By setting the average particle size of component [B-2] to 0.5 μm or more, a decrease in latency due to undesired dissolution of component [B-2] in the epoxy resin during the resin kneading process or the prepreg manufacturing process is suppressed.

[0125] The average particle size referred to in this specification is measured in accordance with ISO 13320:2020(E) using a laser diffraction scattering method using an LA-950 manufactured by Horiba, Ltd. The volume-based results measured using ARALDITE® GY282 (component: bisphenol F type epoxy, manufactured by Huntsman Corporation) as a dispersion medium are used as the measurement result of particle size distribution, and the particle size (median size) at 50% in the cumulative curve of the obtained particle size distribution is used as the average particle size.

[0126] In a particular embodiment, the melting point of component [B-2] in the present invention is preferably 180°C or higher, such as 200°C or higher, such as 220°C or higher, such as 250°C or higher. When the melting point of component [B-2] is 180°C or higher, component [B-2] does not easily dissolve in component [A], and as a result, an improved pot life of the epoxy resin composition is obtained during the resin kneading process or the prepreg manufacturing process. When the pot life is improved, it is possible to suppress poor impregnation of the resin into the reinforcing fiber or a decrease in the tackiness of the prepreg caused by an increase in the viscosity of the resin composition. The pot life referred to in this specification is the viscosity stability of the epoxy resin composition in a temperature range from room temperature to 80°C at the lowest. The viscosity stability can be identified, for example, by evaluating the viscosity change of the epoxy resin composition after keeping it at 80°C for 4 hours by dynamic viscoelasticity measurement. If the melting point of component [B-2] exceeds 250°C, component [B-2] will not easily dissolve in component [A] during curing, and therefore, undesirably, the curability of the epoxy resin composition may decrease.

[0127] Furthermore, the melting points referred to herein can be determined from the peak temperature of the melting curve obtained by heating from room temperature at a rate of 10° C. / min in a differential scanning calorimeter (DSC) according to ASTM D 3418-15.

[0128] In one embodiment, the content of the organic acid hydrazide compound may be 1 to 20 parts by mass, preferably 2 to 15 parts by mass, and more preferably 3 to 10 parts by mass, based on 100 parts by mass of the component [A]. By setting the content to 1 part by mass or more, it is possible to realize the effect of improving the reactivity of the epoxy resin composition. Furthermore, by setting the content to 20 parts by mass or less, it may be possible to suppress undesirable deterioration in the latency of the epoxy resin composition and the heat resistance of the obtained cured epoxy resin composition.

[0129] In another embodiment, the equivalent ratio of all active hydrogens of component [B-1] to all active hydrogens of component [B-2] is adjusted according to the specific curing agents [B-1] and [B-2] used, but is within the range of 1 to 10, such as 2 to 8, such as 3 to 10, such as 1 to 7, such as 1 to 5. By setting the ratio within this range, it is possible to obtain a fiber-reinforced composite material having high levels of heat resistance and mechanical properties from the epoxy resin composition. The equivalent ratio of all active hydrogens of component [B-1] to all active hydrogens of component [B-2] was determined from the following formula.

number

[0130] In one embodiment, when a combination of an aromatic amine compound and an organic acid hydrazide compound is used as the first curing agent [B-1] and the second curing agent [B-2], respectively, the equivalent ratio of all active hydrogens of the components [B-1] and [B-2] to all epoxy groups of the component [A] is 0.7 to 1.3, preferably 0.8 to 1.2, more preferably 0.9 to 1.1, for the purpose of improving heat resistance and mechanical properties. If this equivalent ratio is less than 0.7, the resulting cured epoxy resin composition may not have a sufficiently high crosslink density, which may lead to a lack of appropriate elastic modulus and heat resistance, and the resulting fiber reinforced composite material may not exhibit sufficient static strength properties. If this equivalent ratio is more than 1.3, the resulting cured epoxy resin composition may have an excessively high crosslink density, which may lead to a lack of plastic deformation ability, and the resulting fiber reinforced composite material may not exhibit sufficient impact resistance. As used herein, the phrase "active hydrogen" refers to a hydrogen atom that is covalently bonded to a nitrogen atom, an oxygen atom, or a sulfur atom in an organic compound and participates in a chemical reaction with an epoxy group. For example, the number of active hydrogens in a primary amino group is 2, while the number of active hydrogens in a hydroxyl group or a thiol group is 1. In the case of hydrazides, only the hydrogen atom bonded to the terminal nitrogen atom contributes to the reaction with the epoxy group, so the number of active hydrogens per hydrazide group is counted as 2. When the equivalent ratio of all active hydrogens in components [B-1] and [B-2] to all epoxy groups in component [A] falls within the above-mentioned predetermined range, a resin cured product exhibiting very excellent heat resistance and elastic modulus is obtained. The equivalent ratio of all active hydrogens in components [B-1] and [B-2] to all epoxy groups in component [A] was determined from the following formula:

number

[0131] In the above formula, "epoxy resin n" represents the nth epoxy resin component among all epoxy resin components present as component [A]. For example, when three types of epoxy resins are used in the epoxy resin composition of the present invention, n is 3.

[0132] For most commercial chemical compounds, the active hydrogen equivalent of the hardener product and the epoxy equivalent of the epoxy resin product are available from their manufacturers. If the equivalent weight of the product is unknown, it can be calculated based on the structural formula if the product is a pure substance, or determined from titration if the product is a mixture.

[0133] [C] Accelerator Component [C] used in the present invention is at least one accelerator that accelerates the reaction of the epoxy resin with the curing agent.

[0134] The selection of the accelerator used as component [C] in the present invention is not limited to any particular accelerator, so long as relationship (I) described herein is satisfied.

[0135] In one embodiment, component [C] comprises a promoter (catalyst) known in the art, such as an amine (such as a tertiary amine), an organophosphine, a heterocyclic nitrogen compound (such as an imidazole), an ammonium salt (such as benzyltrimethylammonium chloride), a phosphonium salt (such as ethyltriphenylphosphonium bromide), a carboxylate salt, an arsonium salt, a sulfonium salt, and any combination thereof.

[0136] In one particular embodiment, component [C] preferably comprises at least one organophosphorus compound as component [C-1], which promotes the reaction of component [A] and at least one curing agent.

[0137] The selection of the organophosphorus compound used as component [C-1] in the present invention is not limited to any particular organophosphorus compound and may vary depending on the requirements of the application.

[0138] Non-limiting examples of organophosphorus compounds of the present invention include organophosphines, phosphonium salts, organophosphates, phosphonates, phosphinates, phosphoranes, phosphites, phosphonites, phosphinites, and any combination thereof.

[0139] In a particular embodiment, the component [C-1] is preferably an organic phosphine for the purpose of achieving a balance between latency, reactivity of the epoxy resin composition, and desired mechanical properties of the cured epoxy resin.

[0140] Specific examples of the organic phosphine compound include, but are not limited to, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tri-2,4-xylylphosphine, tri-2,5-xylylphosphine, tri-3,5-xylylphosphine, tris(p-tert-butylphenyl)phosphine, tris(p-methoxyphenyl)phosphine, tris(o-methoxyphenyl)phosphine, tris(p-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, diphenylphosphine, nylcyclohexylphosphine, tricyclohexylphosphine, tri-n-butylphosphine, tri-n-octylphosphine, tri-tert-butylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, di-tert-butylphenylphosphine, [4-(n,n-dimethylamino)]phenyl]di-tert-butylphosphine, tris(diethylamino)phosphine, triphenylphosphine oxide, and triphenylphosphinetriphenylborane.

[0141] Preferred organophosphine compounds are triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(p-methoxyphenyl)phosphine, diphenylcyclohexylphosphine, triphenylphosphine oxide, and triphenylphosphinetriphenylborane.

[0142] Specific examples of the phosphonium salt include, but are not limited to, tetraphenylphosphonium bromide, methyltriphenylphosphonium bromide, methyltriphenylphosphonium chloride, ethyltriphenylphosphonium bromide, n-propyltriphenylphosphonium bromide, i-propyltriphenylphosphonium iodide, n-butyltriphenylphosphonium bromide, methoxymethyltriphenylphosphonium chloride, benzyltriphenylphosphonium chloride, 2-carboxyethyltriphenylphosphonium bromide, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, and the like. phosphate, tetraphenylphosphonium tetrafluoroborate, p-tolyltriphenylphosphonium tetra-p-tolylborate, tri-tert-butylphosphonium tetraphenylborate, di-tert-butylmethylphosphonium tetraphenylborate, tri-tert-butylphosphonium tetrafluoroborate, di-tert-butyl(methyl)phosphonium tetrafluoroborate, n-butyldi(tert-butyl)phosphonium tetrafluoroborate, di-tert-butyl(2-butenyl)phosphonium tetrafluoroborate, and di-tert-butyl(3-methyl-2-butenyl)phosphonium tetrafluoroborate.

[0143] In another embodiment, the amount of component [C] is 0.1 to 10 parts by weight, such as 0.2 to 5 parts by weight, such as 0.5 to 2 parts by weight, based on 100 parts by weight of component [A]. Accelerator concentrations lower than this typically do not provide sufficient accelerating effect, resulting in a significant reduction in the reactivity of the epoxy resin composition. Accelerator concentrations higher than this typically result in undesirably high reactivity and inadequately low latency of the epoxy resin composition.

[0144] In one embodiment, the melting point of component [C] is preferably 220° C. or less, as measured by DSC at a heating rate of 10° C. / min according to ASTM D 3418-15. When the melting point of component [C] is 220° C. or less, component [C] becomes more easily dissolved in component [A] during curing of the epoxy resin composition, thereby promoting the reaction between component [A] and at least one curing agent. When the melting point of component [C] is more than 220° C., component [C] can be completely dissolved in component [A] during curing of the epoxy resin composition, which may result in insufficient promotion effect.

[0145] In another embodiment, the melting point of component [C] is 200°C or less, such as 180°C or less, such as 160°C or less, such as 140°C or less, such as 120°C or less, such as 100°C or less, such as 80°C or less.

[0146] thermoplastic resin In certain embodiments of the present invention, it may be desirable to mix or dissolve at least one thermoplastic resin in the above-mentioned epoxy resin composition in order to improve the properties of the cured epoxy resin composition and the resulting fiber-reinforced composite material, as well as to increase the minimum viscosity during curing to improve processability. In general, thermoplastic resins having chemical bonds in the main chain of the thermoplastic resin selected from the group consisting of carbon-carbon bonds, amide bonds, imide bonds, ester bonds, ether bonds, carbonate bonds, urethane bonds, thioether bonds, sulfone bonds, and / or carbonyl bonds are preferred. Furthermore, the thermoplastic resin may also have a partially crosslinked structure and may be crystalline or amorphous. In particular, it is suitable or preferable that at least one thermoplastic resin selected from the group consisting of polyamide, polycarbonate, polyacetal, polyphenylene oxide, polyphenylene sulfide, polyarylate, polyester, polyamideimide, polyimide resin (including polyimide resin having a phenyltrimethylindane structure or a phenylindane structure), polyetherimide, polysulfone, polyethersulfone, polyetherketone, polyetheretherketone, polyaramid, polyethernitrile, and polybenzimidazole is mixed or dissolved in the epoxy resin composition.

[0147] In one embodiment, the thermoplastic resin is preferably soluble in the epoxy resin used as component [A]. Furthermore, the incorporation of the thermoplastic resin is expected to improve the adhesion between the matrix resin and the carbon fiber, and therefore, it is preferable to use a thermoplastic resin containing a functional group capable of participating in hydrogen bonding. Examples of such functional groups include hydroxyl groups, amide bonds, sulfonyl groups, carbonyl groups, and carboxyl groups.

[0148] As used herein, the expression "soluble in epoxy resin" refers to a temperature range in which a homogeneous phase is formed as a result of mixing the thermoplastic resin with the epoxy resin [A] and subsequent heating and stirring. The expression "forms a homogeneous phase" refers to a state in which no phase separation is observed by visual inspection. As long as a homogeneous phase can be formed within a certain temperature range, phase separation may occur in other temperature ranges.

[0149] For example, if a thermoplastic resin dissolves in an epoxy resin when heated, it can be considered to be "soluble in an epoxy resin" even if separation occurs when cooled to 23°C. Dissolution can be confirmed by the following method. Specifically, a powder of a thermoplastic resin is mixed with an epoxy resin and maintained at a constant temperature below the glass transition temperature of the thermoplastic resin for several hours, e.g., 2 hours, while measuring the viscosity change. Whether a thermoplastic resin is soluble in an epoxy resin can be determined based on whether the measured viscosity is 5% or more higher than the viscosity of the epoxy resin alone heated at the same constant temperature.

[0150] Examples of thermoplastic resins having an alcoholic hydroxyl group include polyvinyl acetal resins such as polyvinyl formal and polyvinyl butyral, as well as polyvinyl alcohol and phenoxy resins.

[0151] Examples of thermoplastic resins having an amide bond include polyamide, polyimide resin, polyamideimide, and polyvinylpyrrolidone.

[0152] Examples of thermoplastic resins having a sulfonyl group include polysulfone and polyethersulfone.

[0153] Examples of thermoplastic resins having carboxyl groups include polyesters, polyamides, and polyamideimides. The carboxyl groups may be located in the main chain and / or at the chain ends.

[0154] Examples of thermoplastic resins having a carbonyl group include aromatic polyether ketones such as polyether ether ketones.

[0155] The above-mentioned thermoplastic resins, polyamides, polyimide resins, and polysulfones may further contain functional groups such as ether bonds or carbonyl groups in their main chains. In the case of polyamide compounds, the nitrogen atoms of the amide groups may have substituents.

[0156] An example of a thermoplastic resin that is soluble in an epoxy resin is a thermoplastic resin having a polyaryl ether skeleton. By using such a thermoplastic resin having a polyaryl ether skeleton, the tack of the resulting prepreg and the fluidity of the matrix resin during thermal curing of the prepreg are controlled, and a tough fiber-reinforced composite material can be obtained without impairing the heat resistance or elastic modulus.

[0157] Examples of thermoplastic resins having a polyaryl ether skeleton include polysulfone, polyphenylsulfone, polyethersulfone, polyetherimide, polyphenylene ether, polyetheretherketone, and polyetherethersulfone, and these thermoplastic resins may be used alone or as a mixture of two or more thereof.

[0158] In order to ensure high heat resistance, the thermoplastic resin having a polyaryl ether skeleton preferably has a glass transition temperature (Tg) of at least 150° C., more preferably 170° C. or higher. If the glass transition temperature of the thermoplastic resin having a polyaryl ether skeleton is less than 150° C., a molded article produced therefrom may be susceptible to thermal deformation. The glass transition temperature of the thermoplastic resin is determined by performing differential scanning calorimetry at a temperature rise rate of 10° C. / min in the temperature range from 0° C. to 350° C., and calculating the midpoint temperature according to JIS K7121-1987.

[0159] The terminal functional groups in the thermoplastic resin having a polyaryl ether skeleton are preferably hydroxyl groups, carboxyl groups, thiol groups, anhydrides, etc., because these groups can react with cationically polymerizable compounds.

[0160] Specific examples of thermoplastic resins having a polyaryl ether skeleton and also such terminal functional groups include SUMIKAEXCEL (registered trademark) PES3600P, SUMIKAEXCEL (registered trademark) PES5003P, SUMIKAEXCEL (registered trademark) PES5200P, and SUMIKAEXCEL (registered trademark) PES7200P (all manufactured by Sumitomo Chemical Co., Ltd.), as well as Virantage (registered trademark) VW-10200RFP and Virantage (registered trademark) VW-10300. Examples of suitable oligomers include polyethersulfones such as Virantage® VW-10700RFP, and Virantage® VW-10700RFP (all from Solvay), as well as copolymer oligomers of polyethersulfone and polyetherethersulfone as described in PCT Publication WO 2002 / 016456(A2), and commercially available polyetherimides such as Ultem® 1000, Ultem® 1010, and Ultem® 1040 (all from SABIC). An oligomer, as referred to herein, is a polymer composed of a finite number of monomers linked together, typically 10 to 100.

[0161] In certain embodiments, the use of polysulfone or polyethersulfone is preferred to achieve solubility in the epoxy resin and to improve heat resistance, solvent resistance, and toughness.

[0162] There is no particular restriction on the weight average molecular weight of the thermoplastic resin, but it is preferably in the range of 2,000 to 60,000 g / mol, more preferably 10,000 to 55,000 g / mol, even more preferably 15,000 to 50,000 g / mol, and particularly preferably 15,000 to 30,000 g / mol. If the weight average molecular weight of the thermoplastic resin is less than 2,000 g / mol, any improvement in mechanical properties will be slight, and the heat resistance of the epoxy resin composition will deteriorate. If the weight average molecular weight of the thermoplastic resin is more than 60,000 g / mol, the compatibility with the epoxy resin composition may be low, and the mechanical properties of the cured epoxy resin composition or fiber reinforced composite material will not be improved. In addition, when such a thermoplastic resin is dissolved in the epoxy resin, even if a small amount is blended, the resulting viscosity may be too high, and the tackiness and drapeability will be reduced during the production of the prepreg. When a thermoplastic resin having a weight average molecular weight of 2,000 to 60,000 g / mol is used, the compatibility with the epoxy resin composition is improved, and the mechanical properties are improved without impairing the heat resistance of the epoxy resin composition. Furthermore, appropriate tackiness and drapeability are achieved during the production of prepregs.

[0163] The weight average molecular weight and number average molecular weight of the components used in the present invention can be determined by gel permeation chromatography ("GPC"). The number average molecular weight of a monomer corresponds to the molecular weight of one monomer unit. An example of a method for measuring the weight average molecular weight and number average molecular weight is to use two Shodex 80M (registered trademark) [columns] (Showa Denko) and one Shodex 802 (registered trademark) [column] (Showa Denko), inject 0.3 μL of sample, and convert the retention time of the sample measured at a flow rate of 1 mL / min to molecular weight by using the retention time of a calibration sample made of polystyrene. When multiple peaks are observed in liquid chromatography, the target components are previously separated by liquid chromatography, and then each component is subjected to GPC, followed by conversion to molecular weight.

[0164] Although the epoxy resin composition does not need to contain a thermoplastic resin, in various embodiments of the present invention, the epoxy resin composition contains at least 1 part by weight, at least 5 parts by weight, or at least 10 parts by weight of the thermoplastic resin. For example, the thermoplastic resin accounts for 1 to 30 parts by weight per 100 parts by weight of component [A]. By setting the amount of the thermoplastic resin within such a range, a balance can be obtained between the viscosity of the epoxy resin composition, the tackiness of the resulting prepreg, and the mechanical properties of the resulting fiber-reinforced composite material.

[0165] In one embodiment, the epoxy resin composition of the present invention may contain thermoplastic particles within a range that does not significantly reduce the heat resistance and curing property of the epoxy resin composition. The thermoplastic particles are used to increase the impact resistance of the fiber-reinforced composite material. A fiber-reinforced composite material generally has a laminate structure, and when an impact is applied to the structure, high stress is generated between the layers of the laminate, causing damage of delamination. In order to improve the resistance of the fiber-reinforced composite material to such external impact, it is therefore only necessary to improve the toughness of the resin layer (hereinafter sometimes referred to as the "interlayer resin layer") formed between the layers containing the reinforcing fibers of the fiber-reinforced composite material. In the present invention, the toughness of the fiber-reinforced composite material is improved by adding a thermoplastic resin to the epoxy resin composition, and thermoplastic particles are preferably added to selectively increase the toughness of the interlayer resin layer of the fiber-reinforced composite material.

[0166] Examples of thermoplastic particles used in the present invention include the same thermoplastic resins already listed as exemplary thermoplastic resins intended for use in epoxy resins. In particular, polyamide particles are particularly preferred because their very high toughness is useful for the production of fiber-reinforced composite materials with high impact resistance. Among various polyamide particle materials, polyamide 12, polyamide 6, polyamide 11, polyamide 66, polyamide 6 / 12 copolymers, and polyamide polymers modified with epoxy compounds to form semi-IPN structures (semi-IPN polyamides) as described in Example 1 of JP-A-01-104624(A) can exhibit particularly high adhesion to epoxy resins. Here, IPN stands for "interpenetrating polymer network structure", which is a type of polymer blend. Crosslinked polymers are used as blend components, and different crosslinked polymers are partially or completely entangled to form a multiple network structure. Semi-IPN has a multiple network structure formed from crosslinked polymers and linear polymers. Particles containing a semi-IPN thermoplastic resin as a main component can be produced, for example, by dissolving a thermoplastic resin and a thermosetting resin in a common solvent, mixing them uniformly, and reprecipitating them. The use of epoxy resin and semi-IPN polyamide particles is useful for producing a prepreg having high heat resistance and high impact resistance.

[0167] In one embodiment, it is preferred that thermoplastic particles are used in the epoxy resin because it increases the adhesion of the epoxy resin composition used as the matrix resin, which helps to produce fiber reinforced composite materials with improved impact resistance.

[0168] The shape of such thermoplastic particles may be spherical, non-spherical, porous, needle-like, whisker-like, or flake-like. A true sphere is preferred because it does not reduce the flowability of the epoxy resin, and therefore can maintain good impregnation into the fiber layer, and furthermore, in a drop weight impact (or local impact) test of a fiber-reinforced composite material, the degree of delamination caused by the local impact is further reduced, so that when the fiber-reinforced composite material is subjected to stress after impact, the number of delaminations acting as the starting point of fracture due to stress concentration due to the local impact is reduced, making it possible to obtain a fiber-reinforced composite material with high impact resistance.

[0169] Specific examples of polyamide particles include SP-500, SP-10, TR-1, and TR-2 (all manufactured by Toray Industries, Inc.), Orgasol® 1002D, Orgasol® 2001UD, Orgasol® 2001EXD, Orgasol® 2002D, Orgasol® 3202D, Orgasol® 3501D, and Orgasol® 3502D (all manufactured by Arkema).

[0170] In one embodiment, some types of thermoplastic particles have a higher modifying effect because they do not dissolve in the matrix resin during the curing process. The characteristic of not dissolving during the curing process is also effective in maintaining the fluidity of the resin during the curing process and improving the impregnation. Therefore, particles that do not dissolve in the matrix resin during the curing process are preferred for use as the above-mentioned thermoplastic particles.

[0171] In one embodiment, the epoxy resin composition of the present invention may contain rubber particles to further enhance the high impact resistance of the fiber reinforced composite material obtained by curing the prepreg according to the present invention.

[0172] The rubber particles to be used for the present invention may be made of natural or synthetic rubber. In particular, crosslinked rubber particles that are insoluble in epoxy resin are preferred. If the rubber particles are insoluble in epoxy resin, the cured product will have almost the same heat resistance as the cured product of epoxy resin that does not contain the particles. Furthermore, there is no change in morphology depending on the type of thermosetting resin or the curing conditions, and therefore the cured thermosetting resin will have stable physical properties such as toughness. Preferred crosslinked rubber particles include, for example, particles of copolymers with one or more unsaturated compounds, and particles produced through copolymerization of one or more unsaturated compounds with crosslinking monomers.

[0173] Examples of such unsaturated compounds include aliphatic olefins such as ethylene and propylene, aromatic vinyl compounds such as styrene and methylstyrene, conjugated diene compounds such as butadiene, dimethylbutadiene, isoprene, and chloroprene, unsaturated carboxylates such as methyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, propyl methacrylate, and butyl methacrylate, and vinyl cyanides such as acrylonitrile.

[0174] In addition, it may be effective to use a compound having a carboxyl group, an epoxy group, a hydroxyl group, an amino group, an amide group, or other functional group reactive with the epoxy resin or the curing agent. Preferred compounds include acrylic acid, glycidyl methacrylate, vinylphenol, vinylaniline, and acrylamide.

[0175] Preferred examples of such crosslinkable monomers include compounds having a plurality of polymerizable double bonds in one molecule, such as divinylbenzene, diallyl phthalate, and ethylene glycol dimethacrylate.

[0176] These particles can be produced by known conventional polymerization methods, including, for example, emulsion polymerization and suspension polymerization. A typical emulsion polymerization process includes the steps of emulsion polymerization of unsaturated compounds, crosslinking monomers, etc., in the presence of a radical polymerization initiator such as peroxide, a molecular weight regulator such as mercaptan and halogenated hydrocarbon, and an emulsifier, adding a reaction terminator to stop the polymerization reaction after a certain degree of polymerization conversion is reached, and then steam distillation to remove unreacted monomers from the polymerization system, thereby obtaining a latex of a copolymer. Water is removed from such a latex obtained by emulsion polymerization to obtain crosslinked rubber particles.

[0177] Examples of such crosslinked rubber particles include crosslinked acrylonitrile butadiene rubber particles, crosslinked styrene butadiene rubber particles, acrylic rubber particles, and core-shell rubber particles. Core-shell type rubber particles are in the form of spherical polymer particles in which the center and surface portions are formed from different polymers, and may have a simple two-phase structure consisting of a core phase and a single shell phase, or a multi-layer structure (multi-layer core-shell rubber particles) having multiple shell phases, for example consisting of a soft core, a hard shell, a soft shell, and a hard shell arranged in this order from the center to the surface. Here, the soft phase means the above-mentioned rubber phase, while the hard phase means a non-rubber resin phase. These different types of crosslinked rubber particles may be used alone or as a combination of two or more of them.

[0178] The epoxy resin composition may contain thermosetting resin particles and inorganic fillers such as silica gel, carbon black, clay, carbon nanotubes, carbon particles, and metal powders, as long as the advantageous effects of the present invention are not impaired. Examples of carbon black include channel black, thermal black, furnace black, and Ketjen black.

[0179] In a specific embodiment, when the epoxy resin composition is used as a matrix resin for a prepreg, the initial viscosity of the epoxy resin composition at 80°C is preferably within a range of 0.5 to 400 Pa·s. In this specification, the initial viscosity at 80°C refers to the viscosity (V 1 ) means. When the initial viscosity at 80°C is 0.5 Pa·s or more, excessive resin flow hardly occurs when molding a fiber-reinforced composite material, and undesired fluctuations in the reinforcing fiber content can be suppressed. Furthermore, when the initial viscosity at 80°C is 0.5 Pa·s or more, the powder components in the epoxy resin composition do not undesirably settle during molding of the fiber-reinforced composite material, and are uniformly dispersed, so that a fiber-reinforced composite material with good uniformity can be obtained. When the initial viscosity at 80°C is 400 Pa·s or less, the epoxy resin composition can be properly impregnated into the reinforcing fibers during the production of prepregs, and almost no voids are generated in the resulting fiber-reinforced composite material, so that a decrease in the strength of the fiber-reinforced composite material can be suppressed. The initial viscosity of the epoxy resin composition at 80°C is preferably within the range of 0.5 to 400 Pa·s, more preferably within the range of 1 to 200 Pa·s, even more preferably within the range of 5 to 150 Pa·s, and particularly preferably within the range of 5 to 100 Pa·s, so that the epoxy resin composition can be easily impregnated into the reinforcing fibers in the prepreg production step, and a prepreg with a high fiber mass content can be produced.

[0180] In order to have excellent latency together with excellent curability, the epoxy resin composition according to the present invention has a T defined in (I). 1 and T 2 It is essential that the epoxy resin composition satisfies the relationship between T defined in (I). 1 and T 2 When the relationship between the above and the above is satisfied, the reaction between component [A] and component [B-1] is not substantially promoted by component [C], and as a result, a resin cured product having an excellent Tg can be obtained. 3 and T 4When the relationship between the components [A] and [B-2] is satisfied, the reaction between the components [A] and [B-2] is promoted by the component [C]. 3 -T 4 If the reaction rate is less than 5.0, the reaction between component [A] and component [B-2] is not substantially promoted. 5.0>|T 1 -T 2 | (I) 5.0≦T 3 -T 4 (II)

[0181] When [C] promotes the reaction between component [A] and component [B-2], T 4 is always T 3 Less than. T 3 -T 4 is the absolute value, [C] actually slows down the reaction between component [A] and component [B-2], i.e., T 4 >T 3 Therefore, when an epoxy resin composition satisfies the relationship between (I) and (II), it means that component [C] has the ability to selectively promote the reaction between component [A] and component [B-2] in an epoxy resin composition containing components [A], [B-1], [B-2], and [C], and as a result, the epoxy resin composition exhibits excellent latency together with excellent curability.

[0182] In the relationship between (I) and (II), T 1 is the extrapolated onset temperature (℃) of the reaction of a mixture of [A] and [B-1], and T 2 is the extrapolated onset temperature (℃) of the reaction of a mixture of [A], [B-1], and [C], and T 3 is the extrapolated onset temperature (℃) of the reaction of a mixture of [A] and [B-2], and T 4is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-2], and [C]. The extrapolated onset temperature is determined by differential scanning calorimetry at a heating rate of 10°C / min using a mixture described in the "Examples" section of this specification, in which the total number of active hydrogens in [B-1] or [B-2] is 1.0 equivalent per 1.0 equivalent of the total number of epoxy groups in [A], and the mass ratio of [C] to [A] is 1:100. Furthermore, "|T 1 -T 2 As used herein, "|" stands for T 1 and T 2 means the absolute value of the difference between

[0183] In one particular embodiment, |T 1 -T 2 is preferably less than 3.0, more preferably less than 2.0, and even more preferably less than 1.0.

[0184] In another embodiment, T 3 -T 4 is preferably 7.0 or more, more preferably 10.0 or more, even more preferably 12.0 or more, and particularly preferably 15.0 or more.

[0185] In one embodiment, the epoxy resin composition comprises T 1p , T 2p , T 3p , and T 4p The epoxy resin composition satisfies the relationships (III) and (IV) between the components. When the epoxy resin composition satisfies (III), the reaction between component [A] and component [B-1] is not substantially promoted by component [C], and as a result, a resin cured product with an excellent Tg is obtained. On the other hand, when the epoxy resin composition satisfies (IV), the reaction between component [A] and component [B-2] is promoted by component [C]. 3p -T 4p When the epoxy resin composition satisfies (III) and (IV), the component [C] can exhibit a more effective selective promotion ability. 2.0>|T1p -T 2p | (III) 3.0≦T 3p -T 4p (IV)

[0186] In the relationship between (III) and (IV) defined above, T 1p is the peak temperature (℃) in the reaction of the mixture of [A] and [B-1], and T 2p is the peak temperature (℃) in the reaction of the mixture of [A], [B-1], and [C], and T 3p is the peak temperature (℃) in the reaction of the mixture of [A] and [B-2], and T 4p is the peak temperature (°C) in the reaction of a mixture of [A], [B-2], and [C]. The peak temperature is determined by differential scanning calorimetry at a heating rate of 10°C / min using a mixture described in the "Examples" section of this specification in which the equivalent ratio of all active hydrogens in component [B-1] or [B-2] to all epoxy groups in component [A] is 1.0 and the mass ratio of [C] to [A] is 1:100. Furthermore, "|T 1p -T 2p As used herein, "|" stands for T 1p and T 2p The equivalent ratio of all active hydrogens in component [B-1] or [B-2] to all epoxy groups in component [A] was determined from the following formula.

number

[0187] In the above formula, "epoxy resin n" represents the nth epoxy resin component among all the epoxy resin components [A]. For example, when three types of epoxy resins are used in the epoxy resin composition of the present invention, n is 3.

[0188] In one particular embodiment, |T 1p -T 2p | may be less than 1.5, in another embodiment less than 1.0, and in yet another embodiment less than 0.5.

[0189] In another embodiment, T 3p -T 4p may be 5.0 or greater, in another embodiment 7.0 or greater, and in yet another embodiment 10.0 or greater.

[0190] In one embodiment, the component [C-1] results in the epoxy resin composition satisfying the following relationships (V) and (VI). 5.0>|T 1 -T 5 | (V) 2.0>|T 1p -T 5p | (VI)

[0191] In (V) and (VI), T 1 is the starting temperature (℃) of the reaction of the mixture of [A] and [B-1], and T 5 is the onset temperature (℃) of the reaction of the mixture of [A], [B-1], and [C-1], and T 1p is the peak temperature (℃) in the reaction of the mixture of [A] and [B-1], and T 5p is the peak temperature (°C) in the reaction of a mixture of [A], [B-1], and [C-1]. The onset temperature and peak temperature are determined by differential scanning calorimetry (DSC) at a heating rate of 10°C / min using the mixture described in the "Examples" section of this specification, in which the equivalent ratio of all active hydrogens in component [B-1] or [B-2] to all epoxy groups in component [A] is 1.0, and the mass ratio of [C-1] to [A] is 1:100. Furthermore, "|T 1 -T 5 |" and "|T 1p -T 5p As used herein, "|" stands for T 1 and T 5 , and T 1p and T 5p The equivalent ratio of all active hydrogens in component [B-1] or [B-2] to all epoxy groups in component [A] was determined from the following formula.

number

[0192] In the above formula, "epoxy resin n" represents the nth epoxy resin component among all components [A]. For example, when three types of epoxy resins are used in the epoxy resin composition of the present invention, n is 3.

[0193] When an epoxy resin composition satisfies the relationships (V) and (VI), it is highly likely that a resin cured product having excellent latency with excellent curability and excellent Tg will result. This result may be possible because component [C-1] promotes the reaction between component [A] and component [B-2], but does not (largely) promote the reaction between component [A] and component [B-1]. Since the latter reaction tends to result in lower latency than the former reaction, promoting only the former reaction should be favorable for achieving excellent latency with excellent curability.

[0194] In one particular embodiment, |T 1 -T 5 is preferably less than 3.0, more preferably less than 2.0, and even more preferably less than 1.0.

[0195] In another embodiment, |T 1p -T 5p | may be less than 1.5, in another embodiment less than 1.0, and in yet another embodiment less than 0.5.

[0196] In one embodiment, the viscosity (V) of the epoxy resin composition measured after holding at 80° C. for 4 hours 2 ) after holding at 80°C for 1 minute, 1 ) to the ratio (V 2 / V 1 ) is not more than 2.5, preferably not more than 2.0, more preferably not more than 1.6, and even more preferably not more than 1.2. The ratio V reflecting the thickening factor at 80°C 2 / V1 can be used as an index of the pot life of the epoxy resin composition in the kneading process or the prepreg production process. 2 / V 1 A smaller ratio V results in a good pot life at temperatures below 80°C. 2 / V 1 When the viscosity is 2.5 or less, the latency of the epoxy resin composition is high, and the impregnation of the resin into the reinforcing fibers in the prepreg production process is not reduced, and as a result, voids present in the molded product are minimized.

[0197] 80°C for 1 min (V 1 ) and 4 hours (V 2 The viscosity of the epoxy resin composition after the holding is measured in accordance with ASTM D 4473-95a using a dynamic viscoelasticity measuring device (ARES, manufactured by TA Instruments) equipped with parallel plates having diameters of 40 mm (upper) and 50 mm (lower), operated under the conditions of a parallel plate gap of 0.6 mm, an angular frequency of 10 rad / sec, a strain of 10%, and a measurement temperature of 80°C.

[0198] Prepreg / Fiber Reinforced Composites The prepreg of the present invention is produced by impregnating reinforcing fibers with the epoxy resin composition as described above as the matrix resin. Preferred examples of the reinforcing fibers include carbon fibers, graphite fibers, aramid fibers, glass fibers, etc., and among these fibers, carbon fibers are particularly preferred.

[0199] Prepregs can be manufactured by a variety of commonly known methods, such as the wet method, in which the matrix resin is dissolved in a solvent such as methyl ethyl ketone and methanol to reduce the viscosity of the resin, and then the reinforcing fiber bundles are impregnated with the solution, or the hot melt method, in which the matrix resin is heated to reduce the viscosity of the resin, and then the reinforcing fiber bundles are impregnated with the resin.

[0200] In the wet process, prepregs are produced by immersing sized carbon fiber bundles in a solution containing a matrix resin, followed by withdrawing the reinforcing fiber bundles and evaporating the solvent using an oven or other device.

[0201] In the hot melt method, the prepreg is produced by directly impregnating the reinforcing fiber bundle with a matrix resin whose viscosity has been reduced by heat, or, as another option, by preparing a coating film of the matrix resin composition on a release paper or the like, then superposing the film on both sides or one side of the reinforcing carbon fiber bundle, and then applying heat and pressure to the film to impregnate the reinforcing fiber bundle with the matrix resin. The hot melt method is preferred to the wet method because no solvent remains in the prepreg.

[0202] The cross-sectional density of the reinforced fibers in the prepreg is 100 to 1000 g / m 2 etc., 200~1000g / m 2 50~1000g / m 2 The cross-sectional density may be at least 50 g / m 2 When the cross-sectional density is 1000 g / m, the number of prepregs that need to be laminated to ensure a predetermined thickness during molding of the fiber-reinforced composite material can be reduced, and this can simplify the lamination process. 2 When the mass fraction of the reinforcing fibers is less than 90%, the drapeability of the prepreg is well maintained. The reinforcing fiber mass fraction of the prepreg may be 40-90% by mass in some embodiments, 50-85% by mass in other embodiments, or 60-80% by mass in still other embodiments. When the mass fraction of the reinforcing fibers is at least 40% by mass, the fiber content is sufficient to provide a fiber-reinforced composite material with very good specific strength and specific modulus, and to prevent the fiber-reinforced composite material from generating excessive heat during the curing time. When the mass fraction of the reinforcing fibers is less than 90% by mass, the risk of large amounts of void formation in the fiber-reinforced composite material is reduced by impregnation of the reinforcing fibers with the resin.

[0203] A method for forming a fiber reinforced composite material by using the prepreg of the present invention is exemplified by a method in which the prepregs are laminated and the matrix resin is thermally cured while applying pressure to the laminate.

[0204] The application of heat and pressure under the prepreg lamination molding method can be realized by appropriately using a press molding method, an autoclave molding method, a bagging molding method, a wrapping tape method, an internal pressure molding method, or the like.

[0205] Autoclave molding is a method in which prepregs are stacked on a shaped tool plate, then covered with a bagging film, followed by curing by application of heat and pressure while air is pulled out of the stack. This method allows precise control of fiber orientation and also provides high quality molded materials with very good mechanical properties by minimizing void content. The pressure applied during the molding process may be 0.3-1.0 MPa, while the molding temperature may be in the range of 90-300°C.

[0206] The wrapping tape method is a method in which a prepreg is wrapped around a mandrel or some other core to form a tubular fiber reinforced composite. This method can be used in the manufacture of golf shafts, fishing rods, and other rod-shaped products. More specifically, this method involves wrapping a prepreg around a mandrel with a wrapping tape consisting of a thermoplastic film for wrapping over the prepreg under tension to fixate and apply pressure to the prepreg. After curing of the resin by heating in an oven, the mandrel is removed to obtain a tubular body. The tension used in wrapping the wrapping tape can be 20-100 N. The molding temperature can be in the range of 80-300°C.

[0207] The internal pressure molding method is a method in which a preform obtained by wrapping a prepreg around a thermoplastic resin tube or some other internal pressure applicator is set inside a metal mold, and then high pressure gas is introduced into the internal pressure applicator to apply pressure, and the metal mold is heated at the same time to mold the prepreg. This method can be used to mold objects with complex shapes such as golf shafts, bats, and tennis or badminton rackets. The pressure applied during the molding process can be in the range of 0.1 to 2.0 MPa. The molding temperature can be in the range of room temperature to 300°C, or in the range of 180 to 275°C.

[0208] Fiber reinforced composite materials made from the prepregs of the present invention may have a Class A surface, as described herein. The term "Class A surface" refers to a surface that exhibits extremely high finish quality characteristics without aesthetic defects or imperfections.

[0209] Fiber-reinforced composite materials containing the cured epoxy resin composition and reinforcing fibers obtained from curing the epoxy resin composition described herein are advantageously used in sports, general industrial, and aerospace applications. Sports applications in which these materials are advantageously used include, but are not limited to, golf shafts, fishing rods, tennis or badminton rackets, hockey sticks, and ski poles. General industrial applications in which these materials are advantageously used include, but are not limited to, structural materials for vehicles (such as automobiles, bicycles, ships, and railroad cars), drive shafts, leaf springs, windmill blades, pressure vessels, flywheels, papermaking rollers, roofing materials, cables, and repair / reinforcement materials.

[0210] Although the embodiments have been described herein in a manner that enables a clear and concise specification to be written, it is contemplated and understood that the embodiments can be combined or separated in various ways without departing from the invention, and for example, it is understood that all preferred features described herein are applicable to all aspects of the invention described herein.

[0211] Although the present invention is illustrated and described herein with reference to specific embodiments, it is not intended that the scope of the present invention be limited by these embodiments, but rather, various modifications may be made within the scope and range of equivalents of the claims without departing from the present invention. EXAMPLES

[0212] Next, the embodiments of the present invention will be described in more detail by way of examples. Measurements of various properties were performed using the methods described below. These properties were measured under environmental conditions including a temperature of 23°C and a relative humidity of 50%, unless otherwise stated. Prepregs were then made from the exemplary resins using a hot melt prepreg method. The components used in the examples and comparative examples are as follows: <Component [A]> ARALDITE® MY721 (tetraglycidyldiaminodiphenylmethane, Huntsman Corporation, epoxy equivalent weight 114 g / eq) ARALDITE® MY0510 (tetraglycidyldiaminodiphenylmethane, Huntsman Corporation, epoxy equivalent weight 101 g / eq) EPON™ 825 (bisphenol A type epoxy, manufactured by Hexion Inc., epoxy equivalent weight 178 g / equivalent) EPICLON® 830 (bisphenol F type epoxy, manufactured by DIC Corporation, epoxy equivalent weight 169 g / equivalent) EPICLON® 4770 (bisnaphthalene type epoxy resin, manufactured by DIC Corporation, epoxy equivalent weight 205 g / equivalent) TOREP® A-204E (diglycidyl-N-phenoxyaniline, manufactured by Toray Fine Chemicals Co., Ltd., epoxy equivalent weight 167 g / equivalent) <Component [B-1]> SEIKACURE-S (4,4'-diaminodiphenyl sulfone, manufactured by Seika Corporation, active hydrogen equivalent: 62 g / equivalent) ARADUR® 9719-1 (3,3'-diaminodiphenyl sulfone, Huntsman Corporation, active hydrogen equivalent weight 62 g / eq) <Component [B-2]> IDH (isophthalic dihydrazide, manufactured by Otsuka Chemical Co., Ltd., melting point: 220°C, active hydrogen equivalent: 49g / equivalent) Technicure® ADH (adipic acid dihydrazide, manufactured by A&C Catalysts, Inc., melting point: 180°C, active hydrogen equivalent: 29 g / equivalent) NDH (2,6-Naphthalenedicarbohydrazide, melting point: >220°C, active hydrogen equivalent: 61g / equivalent) <Ingredient [C]> TBA-OTF (tetrabutylammonium trifluoromethanesulfonate, manufactured by Sigma-Aldrich, Inc., melting point: 58° C.) EPTS (Ethyl p-toluenesulfonate, manufactured by Sigma-Aldrich, Inc.) Piperidinium BF 3 (Piperidinium trifluoroborate, manufactured by Sigma-Aldrich, Inc.) San-Aid SI-150 (4-acetoxyphenyldimethylsulfonium hexafluoroantimonate, manufactured by Sanshin Chemical Industry Co., Ltd., melting point: 149°C) <Component [C-1]> TPP (triphenylphosphine, manufactured by Hokko Chemical Industry Co., Ltd., melting point: 82°C) TPP-PB (registered trademark) (tetraphenylphosphonium bromide, manufactured by Hokko Chemical Industry Co., Ltd., melting point: 152°C) TPP-S (registered trademark) (triphenylphosphine triphenylborate, manufactured by Hokko Chemical Industry Co., Ltd., melting point: 213°C) <Thermoplastic resin> Virantage® VW-10700RFP (polyethersulfone, Solvay, weight average molecular weight 21,000 g / mol, Tg=220° C.)

[0213] (1) Production of epoxy resin composition The epoxy resin of component [A] and the thermoplastic resin in the amount and ratio shown in Tables A1 to A4 and B1 to B5 were fed into a kneader and heated to 150°C with mixing, followed by stirring for 1 hour so that the thermoplastic resin melted and formed a clear viscous liquid. The liquid was allowed to cool to 75°C with mixing, followed by addition of the curing agents of components [B-1] and [B-2], then the accelerator of component [C], followed by mixing for an additional 30 minutes to obtain an epoxy resin composition. Tables A1 to A4 and B1 to B5 summarize the compositions of various exemplary resin compositions and their reaction characteristics.

[0214] (2) Identification of the extrapolated onset temperature and peak temperature of the epoxy resin composition Extrapolation starting temperature (T 1 ~T 5 ) and peak temperature (T 1p ~T 5p ) was characterized by differential scanning calorimetry (DSC) according to ASTM E 2160-04(2018). T 1 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-1] T 2 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C] T 3 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-2] T 4 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-2], and [C] T 5 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C-1] T 1p : Peak temperature (℃) in the reaction of a mixture of [A] and [B-1] T 2p: Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C] T 3p : Peak temperature (℃) in the reaction of a mixture of [A] and [B-2] T 4p : Peak temperature (℃) in the reaction of a mixture of [A], [B-2], and [C] T 5p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C-1]

[0215] The above mixtures were prepared by mixing the ingredients described below.

[0216] (Examples A1 to A5 1 , T 1p , T 2 , and T 2p ) (Comparative Examples A1 to A2 1 and T 1p ) T 1 and T 1p In order to determine the above, 70 parts by weight of ARALDITE (registered trademark) MY721 and 30 parts by weight of TOREP (registered trademark) A-204E as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 50 parts by weight of SEIKACURE-S as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-1] to all epoxy groups in component [A] was 1.0. 2 and T 2p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0217] (T of Examples A6 to A13 and Comparative Examples A6 to A7 1 , T 1p , T 2 , and T 2p ) (Comparative Examples A3 to A5 1 and T 1p ) T 1 and T 1p To determine this, 70 parts by weight of ARALDITE (registered trademark) MY721 and 30 parts by weight of TOREP (registered trademark) A-204E as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 50 parts by weight of ARADUR (registered trademark) 9719-1 as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-1] to all epoxy groups in component [A] was 1.0. T 2 and T 2p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0218] (Example A14 T 1 , T 1p , T 2 , and T 2p ) (Comparative Example A8 T 1 and T 1p ) T 1 and T 1p To determine the above, 60 parts by weight of ARALDITE® MY721 and 40 parts by weight of EPON® 825 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 48 parts by weight of ARADUR® 9719-1 as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-1] to all epoxy groups in component [A] was 1.0. 2 and T 2p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1pThe same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0219] (Example A15 T 1 , T 1p , T 2 , and T 2p ) (Comparative Example A9 T 1 and T 1p ) T 1 and T 1p In order to specify, 70 parts by weight of ARALDITE (registered trademark) MY721 and 30 parts by weight of EPICLON (registered trademark) 4770 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 48 parts by weight of ARADUR (registered trademark) 9719-1 as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens of component [B-1] to all epoxy groups of component [A] is 1.0. T 2 and T 2p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0220] (Example A16 T 1 , T 1p , T 2 , and T 2p ) (Comparative Example A10 T 1 and T 1p ) T 1 and T 1pIn order to specify the above, 50 parts by weight of ARALDITE (registered trademark) MY721 and 50 parts by weight of ARALDITE (registered trademark) MY0510 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 45 parts by weight of ARADUR (registered trademark) 9719-1 as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens of component [B-1] to all epoxy groups of component [A] was 1.0. 2 and T 2p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0221] (Example A17 T 1 , T 1p , T 2 , and T 2p ) (Comparative Example A11 T 1 and T 1p ) T 1 and T 1p In order to specify, 50 parts by weight of ARALDITE (registered trademark) MY0510 and 50 parts by weight of EPICLON (registered trademark) 830 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 45 parts by weight of ARADUR (registered trademark) 9719-1 as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens of component [B-1] to all epoxy groups of component [A] is 1.0. T 2 and T 2p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0222] (T of Examples A1 to A13 and Comparative Examples A6 to A7 3 , T 3p , T 4 , and T 4p ) (Comparative Examples A1 to A5 3 and T 3p ) T 3 and T 3p In order to specify, 70 parts by weight of ARALDITE (registered trademark) MY721 and 30 parts by weight of TOREP (registered trademark) A-204E as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 40 parts by weight of IDH as component [B-2], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-2] to all epoxy groups in component [A] was 1.0. 4 and T 4p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-2] 3 and T 3p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0223] (Example A14 T 3 , T 3p , T 4 , and T 4p ) (Comparative Example A8 T 3 and T 3p ) T 3 and T 3p In order to specify, 60 parts by weight of ARALDITE (registered trademark) MY721 and 40 parts by weight of EPON (trademark) 825 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 38 parts by weight of IDH as component [B-2], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-2] to all epoxy groups in component [A] was 1.0. 4 and T 4pIn the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-2] 3 and T 3p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0224] (Example A15 T 3 , T 3p , T 4 , and T 4p ) (Comparative Example A9 T 3 and T 3p ) T 3 and T 3p In order to specify, 70 parts by weight of ARALDITE (registered trademark) MY721 and 30 parts by weight of EPICLON (registered trademark) 4770 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 38 parts by weight of IDH as component [B-2], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-2] to all epoxy groups in component [A] was 1.0. 4 and T 4p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-2] 3 and T 3p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0225] (Example A16 T 3 , T 3p , T 4 , and T 4p ) (Comparative Example A10 T 3 and T 3p ) T 3 and T 3pIn order to determine the above, 50 parts by weight of ARALDITE® MY721 and 50 parts by weight of ARALDITE® MY0510 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 36 parts by weight of IDH as component [B-2], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-2] to all epoxy groups in component [A] was 1.0. 4 and T 4p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-2] 3 and T 3p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0226] (Example A17 T 3 , T 3p , T 4 , and T 4p ) (Comparative Example A11 T 3 and T 3p ) T 3 and T 3p In order to specify, 50 parts by weight of ARALDITE (registered trademark) MY0510 and 50 parts by weight of EPICLON (registered trademark) 830 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 36 parts by weight of IDH as component [B-2], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-2] to all epoxy groups in component [A] was 1.0. 4 and T 4p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-2] 3 and T 3p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0227] (Examples B1 to B5 and B18 1 , T1p , T 2 , T 2p , T 5 , and T 5p ) (Comparative Examples B1 to B3 and B16 1 and T 1p ) T 1 and T 1p In order to determine the above, 70 parts by weight of ARALDITE (registered trademark) MY721 and 30 parts by weight of TOREP (registered trademark) A-204E as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 50 parts by weight of SEIKACURE-S as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-1] to all epoxy groups in component [A] was 1.0. 2 , T 2p , T 5 , and T 5p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0228] (T of Examples B6 to B13 and Comparative Examples B8 to B10 1 , T 1p , T 2 , T 2p , T 5 , and T 5p ) (Comparative Examples B4 to B7 and B11 1 and T 1p ) T 1 and T 1pTo determine this, 70 parts by weight of ARALDITE (registered trademark) MY721 and 30 parts by weight of TOREP (registered trademark) A-204E as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 50 parts by weight of ARADUR (registered trademark) 9719-1 as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-1] to all epoxy groups in component [A] was 1.0. T 2 , T 2p , T 5 , and T 5p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0229] (Example B14 T 1 , T 1p , T 2 , T 2p , T 5 , and T 5p ) (Comparative Example B12 T 1 and T 1p ) T 1 and T 1p To determine the above, 60 parts by weight of ARALDITE® MY721 and 40 parts by weight of EPON® 825 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 48 parts by weight of ARADUR® 9719-1 as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens in component [B-1] to all epoxy groups in component [A] was 1.0. 2 , T 2p , T 5 , and T 5p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1pThe same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0230] (Example B15 T 1 , T 1p , T 2 , T 2p , T 5 , and T 5p ) (Comparative Example B13 T 1 and T 1p ) T 1 and T 1p In order to specify, 70 parts by weight of ARALDITE (registered trademark) MY721 and 30 parts by weight of EPICLON (registered trademark) 4770 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 48 parts by weight of ARADUR (registered trademark) 9719-1 as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens of component [B-1] to all epoxy groups of component [A] is 1.0. T 2 , T 2p , T 5 , and T 5p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0231] (Example B16 T 1 , T 1p , T 2 , T 2p , T 5 , and T 5p ) (Comparative Example B14 T 1 and T 1p ) T 1 and T 1pIn order to specify the above, 50 parts by weight of ARALDITE (registered trademark) MY721 and 50 parts by weight of ARALDITE (registered trademark) MY0510 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 45 parts by weight of ARADUR (registered trademark) 9719-1 as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens of component [B-1] to all epoxy groups of component [A] was 1.0. 2 , T 2p , T 5 , and T 5p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1p The same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0232] (Example B17 T 1 , T 1p , T 2 , T 2p , T 5 , and T 5p ) (Comparative Example B15 T 1 and T 1p ) T 1 and T 1p In order to specify, 50 parts by weight of ARALDITE (registered trademark) MY0510 and 50 parts by weight of EPICLON (registered trademark) 830 as component [A] were fed into a kneader and heated to 75°C while mixing, followed by adding 45 parts by weight of ARADUR (registered trademark) 9719-1 as component [B-1], followed by further mixing for 30 minutes to obtain a mixture. Here, the equivalent ratio of all active hydrogens of component [B-1] to all epoxy groups of component [A] is 1.0. T 2 , T 2p , T 5 , and T 5p In the case of specifying T, except that 1.0 part by mass of component [C] was added after the addition of component [B-1] 1 and T 1pThe same procedure as in identifying the component [C] was carried out to obtain a mixture having a mass ratio of component [A] of 1:100.

[0233] Approximately 4 mg samples of these mixtures were sampled, and then each sample was placed in a nitrogen atmosphere of a differential scanning calorimeter (DSC Q200, TA Instruments) and the temperature was maintained at -50°C for 1 min, and then heated once over the temperature range up to 325°C at a heating rate of 10°C / min to obtain a DSC curve of heat flow versus temperature. The temperature corresponding to the intersection of the extrapolated baseline and the tangent to the maximum rate of change point was reported as the extrapolated onset temperature according to ASTM E 2160-04(2018).

[0234] (3) Identification of the gel time of the epoxy resin composition The gel time of the epoxy resin composition was determined using an Advanced Polymer Analyzer (APA2000, manufactured by ALPHA Technologies) operated under the conditions of a parallel plate die type, a die gap of 2.583 mm, a frequency of 1.67 Hz, and a strain of 0.7%. The measurement temperature was increased from 40°C to 105°C at a rate of 1.7°C / min, and then held at 105°C for 12 hours. According to ASTM D 4473-95a, the time from the start of heating at 0 min to the crossover point, i.e., the point at which the storage modulus (G') value was greater than the loss modulus (G'') value, was reported as the gel time.

[0235] (4) Viscosity of the epoxy resin composition (V 1 and V 2 ) Measurement 80°C for 1 min (V 1 ) and 4 hours (V 2 The viscosity of the epoxy resin composition after the above-mentioned holding was measured in accordance with ASTM D 4473-95a using a dynamic viscoelasticity measuring device (ARES, manufactured by TA Instruments) equipped with parallel plates having diameters of 40 mm (upper) and 50 mm (lower), operated under the conditions of a parallel plate gap of 0.6 mm, an angular frequency of 10 rad / sec, a strain of 10%, and a measurement temperature of 80°C.

[0236] (5) Identifying the melting points of components The melting points of components [B] and [C] were determined from the peak temperatures of the melting curves obtained by DSC using about 4 mg of each component as a sample in accordance with ASTM D 3418-15.

[0237] Examples A1 to A4 and Comparative Example A1 Comparative Example A1 did not contain component [C], while Examples A1-A4 used various amounts of component [C], and the epoxy resin composition was found to have a T value of 0.01 or less as defined in (I) and (II). 1 , T 2 , T 3 , and T 4 The gelation times of Examples A1 to A4 were shortened by 9% or more compared to Comparative Example A1, while sufficient latency was maintained.

[0238] Example A5 and Comparative Example A2 Comparative Example A2 does not contain component [C], while Example A5 uses component [C], and the epoxy resin composition has a T value of 1.0 or less as defined in (I) and (II). 1 , T 2 , T 3 , and T 4 The relationship was satisfied. The amount of component [B-2] was less than that in Examples A1 to A4 and Comparative Example A1. The gel time of Example A5 was shortened by 8% compared to Comparative Example A2, while maintaining sufficient latency.

[0239] Examples A6 to A9 and Comparative Examples A3 to A5 Comparative Examples A3 to A5 did not contain component [C], while Examples A6 to A9 used various amounts of component [C], and the epoxy resin compositions were found to be within the T ranges defined in (I) and (II). 1 , T 2 , T 3 , and T 4The relationship was satisfied. The component [B-1] was different from that used in Examples A1 to A5 and Comparative Examples A1 to A2. In Comparative Examples A3 to A5, the gelation time was not shortened even when the amount of component [B-2] was increased. On the other hand, the gelation time of Examples A6 to A9 was shortened by 5% or more compared to Comparative Examples A3 to A5, while sufficient latency was maintained.

[0240] Examples A10 to A13 and Comparative Examples A3, A6 to A7 In Comparative Examples A6 to A7, various components [C] were used, but the epoxy resin compositions were not more than T defined in (I). 1 and T 2 On the other hand, in Examples A10 to A13, various components [C] are used, and the epoxy resin compositions do not satisfy the T 1 , T 2 , T 3 , and T 4 The gelation time of Examples A10 to A13 was shortened by 12% or more compared to Comparative Example A3, while sufficient latency was maintained. On the other hand, in Comparative Examples A6 to A7, the gelation time was sufficiently shortened compared to Comparative Example 3, but the latency was significantly worse than that of Examples A10 to A13.

[0241] Examples A14 to A17 and Comparative Examples A8 to A11 Comparative Examples A14 to A17 used various components [A] but did not contain component [C], whereas Examples A14 to A17 used various components [A] and [C], and the epoxy resin compositions were in the range of T defined in (I) and (II). 1 , T 2 , T 3 , and T 4 The gelation times of Examples A14 to A17 were shortened by 7% or more compared to Comparative Examples A10 to A13, respectively, while sufficient latency was maintained.

[0242] Examples B1 to B4 and Comparative Examples B1 and B3 Comparative Examples B1 and B3 did not contain component [C], while Examples B1-B4 used various amounts of component [C]. The gel times of Examples B1-B4 were reduced by more than 9% compared to Comparative Examples B1 and B3, while maintaining sufficient latency.

[0243] Example B5 and Comparative Examples B2 and B3 Comparative Examples B2 and B3 did not contain component [C], while Example B5 used component [C]. Here, the amount of component [B-2] was less than that in Examples B1 to B4 and Comparative Example B1. The gel time of Example B5 was reduced by 8% compared to Comparative Examples B2 and B3, while sufficient latency was maintained.

[0244] Examples B6 to B9 and Comparative Examples B4 to B7 Comparative Examples B4-B7 did not contain component [C], whereas Examples B6-B9 used component [C]. Here, component [B-1] was different from that used in Examples B1-B5 and Comparative Examples B1-B3. In Comparative Examples B5-B7, the gel time was not shortened by increasing the amount of component [B-2]. On the other hand, the gel time of Examples B6-B9 was shortened by more than 5% compared to Comparative Examples B4-B7, while sufficient latency was maintained.

[0245] Examples B10 to B12 and Comparative Examples B5, B8 to B10 Comparative Examples B8-B10 used various accelerators other than component [C], while Examples B7-B10 used various components [C]. The gel times of Examples B10-B12 were reduced by more than 19% compared to Comparative Example B5, while sufficient latency was maintained. On the other hand, in Comparative Examples B8-B10, the gel times were reduced by more than 19% compared to Comparative Example B5, but the latency was significantly worse than that of Examples B10-B12.

[0246] Example B13 and Comparative Example B11 Comparative Example B11 did not contain component [C], whereas Example B13 used component [C]. Here, component [B-2] was different from that used in Examples B1 to B12 and Comparative Examples B1 to B10. The gel time of Example B13 was reduced by 3% compared to Comparative Example B11, while sufficient latency was maintained.

[0247] Examples B14 to B17 and Comparative Examples B12 to B15 Comparative Examples B12-B15 used various components [A] but did not contain component [C], while Examples B14-B17 used various components [A] and [C]. The gel times of Examples B14-B17 were reduced by 7% or more compared to Comparative Examples B12-B15, respectively, while maintaining sufficient latency. [Table A1] T 1 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-1] T 2 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C] T 3 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-2] T 4 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-2], and [C] (I):5.0>|T 1 -T 2 | (II): 5.0≦T 3 -T 4 Gel time reduction rate: Gel time reduction rate compared to the control resin V 1 : Viscosity after holding at 80℃ for 1 minute V 2 : Viscosity after holding at 80℃ for 4 hours Y means that the example satisfies relationship (I) or (II). N means that the example does not satisfy relationship (I) or (II). [Table A2] T 1 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-1] T 2 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C] T 3 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-2] T 4 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-2], and [C] (I):5.0>|T 1 -T 2 | (II): 5.0≦T 3 -T 4 Gel time reduction rate: Gel time reduction rate compared to the control resin V 1 : Viscosity after holding at 80℃ for 1 minute V 2 : Viscosity after holding at 80℃ for 4 hours Y means that the example satisfies relationship (I) or (II). N means that the example does not satisfy relationship (I) or (II). [Table A3] T 1 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-1] T 2 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C] T 3 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-2] T 4 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-2], and [C] (I):5.0>|T 1 -T 2 | (II): 5.0≦T 3 -T 4 Gel time reduction rate: Gel time reduction rate compared to the control resin V 1 : Viscosity after holding at 80℃ for 1 minute V 2 : Viscosity after holding at 80℃ for 4 hours Y means that the example satisfies relationship (I) or (II). N means that the example does not satisfy relationship (I) or (II). [Table A4] T 1 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-1] T 2 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C] T 3 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-2] T 4 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-2], and [C] (I):5.0>|T 1 -T 2 | (II): 5.0≦T 3 -T 4 Gel time reduction rate: Gel time reduction rate compared to the control resin V 1 : Viscosity after holding at 80℃ for 1 minute V 2 : Viscosity after holding at 80℃ for 4 hours Y means that the example satisfies relationship (I) or (II). N means that the example does not satisfy relationship (I) or (II). [Table B1] Gel time reduction rate: Gel time reduction rate compared to the control resin V 1 : Viscosity after holding at 80℃ for 1 minute V2 : Viscosity after holding at 80℃ for 4 hours T 1 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-1] T 2 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C] T 5 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C-1] T 1p : Peak temperature (℃) in the reaction of a mixture of [A] and [B-1] T 2p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C] T 5p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C-1] [Table B2] Gel time reduction rate: Gel time reduction rate compared to the control resin V 1 : Viscosity after holding at 80℃ for 1 minute V 2 : Viscosity after holding at 80℃ for 4 hours T 1 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-1] T 2 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C] T 5 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C-1] T 1p : Peak temperature (℃) in the reaction of a mixture of [A] and [B-1] T 2p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C] T 5p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C-1] [Table B3] Gel time reduction rate: Gel time reduction rate compared to the control resin V 1 : Viscosity after holding at 80℃ for 1 minute V 2 : Viscosity after holding at 80℃ for 4 hours T 1 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-1] T 2 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C] T 5 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C-1] T 1p : Peak temperature (℃) in the reaction of a mixture of [A] and [B-1] T 2p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C] T 5p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C-1] [Table B4] Gel time reduction rate: Gel time reduction rate compared to the control resin V 1 : Viscosity after holding at 80℃ for 1 minute V 2 : Viscosity after holding at 80℃ for 4 hours T 1 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-1] T 2 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C] T 5 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C-1] T 1p : Peak temperature (℃) in the reaction of a mixture of [A] and [B-1] T 2p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C] T5p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C-1] [Table B5] Gel time reduction rate: Gel time reduction rate compared to the control resin V 1 : Viscosity after holding at 80℃ for 1 minute V 2 : Viscosity after holding at 80℃ for 4 hours T 1 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A] and [B-1] T 2 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C] T 5 : Extrapolated onset temperature (℃) for the reaction of a mixture of [A], [B-1], and [C-1] T 1p : Peak temperature (℃) in the reaction of a mixture of [A] and [B-1] T 2p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C] T 5p : Peak temperature (℃) in the reaction of a mixture of [A], [B-1], and [C-1]

Claims

1. An epoxy resin composition comprising: [A] at least one epoxy resin, [B] at least two curing agents, [B-1] At least one first curing agent; [B-2] at least one second curing agent different from the first curing agent; At least two curing agents, [C] at least one accelerator; wherein the component [B-1] comprises at least one aromatic amine compound, and the component [B-2] comprises at least one compound selected from the group consisting of 3-hydroxy-2-naphthoic acid hydrazide, 2,6-naphthalenedicarboxylic acid dihydrazide, and isophthalic acid dihydrazide, The component [C] contains at least one compound selected from the group consisting of a phosphine compound, a phosphonium salt, and an ammonium salt, The epoxy resin composition satisfies (I), 5.0>|T １ -T ２ | (I) During the ceremony, T １ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-1], T ２ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-1], and [C]; The extrapolation start temperature T １ and T ２ is the mixture in which the equivalent ratio of all active hydrogens of [B-1] or [B-2] to all epoxy groups of [A] is 1.0, and the mass ratio of [C] to [A] is 1:

100. １ and T ２ The epoxy resin composition is characterized by differential scanning calorimetry of the mixture at a heating rate of 10° C. / min.

2. The epoxy resin composition further satisfies (II), _..≦) ３  ４ (=) During the ceremony, T ３ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-2], T ４ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-2], and [C]; The extrapolation start temperature T ３ and T ４ is the mixture in which the equivalent ratio of all active hydrogens of [B-2] to all epoxy groups of [A] is 1.0, and the mass ratio of [C] to [A] is 1:

100. ３ and T ４ 2. The epoxy resin composition according to claim 1, characterized by differential scanning calorimetry of a mixture of the above at a heating rate of 10° C. / min.

3. An epoxy resin composition comprising: [A] at least one epoxy resin, [B] at least two curing agents, [B-1] At least one first curing agent; [B-2] at least one second curing agent different from the first curing agent; At least two curing agents, [C] at least one accelerator; Including, [B-1] contains at least one aromatic amine compound, [B-2] contains at least one organic acid hydrazide compound, [C] is [C-1] at least one organic phosphine compound; wherein the component [C-1] promotes the reaction between the component [A] and at least one curing agent, The component [A] is present in an amount of 100 parts by mass, the component [B-2] is present in an amount of 1 to 20 parts by mass, and the component [C-1] is present in an amount of 0.1 to 10 parts by mass, the equivalent ratio of all active hydrogens in the components [B-1] and [B-2] to all epoxy groups in the component [A] is 0.7 to 1.3; The epoxy resin composition satisfies (I), 5.0>|T １ -T ２ | (I) During the ceremony, T １ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-1], T ２ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-1], and [C]; The extrapolation start temperature T １ and T ２ is the mixture in which the equivalent ratio of all active hydrogens of [B-1] or [B-2] to all epoxy groups of [A] is 1.0, and the mass ratio of [C] to [A] is 1:

100. １ and T ２ The epoxy resin composition is characterized by differential scanning calorimetry of the mixture at a heating rate of 10° C. / min.

4. A prepreg including a reinforcing fiber bundle impregnated with an epoxy resin composition, the epoxy resin composition comprising: [A] at least one epoxy resin, [B] at least two curing agents, [B-1] At least one first curing agent; [B-2] at least one second curing agent different from the first curing agent; At least two curing agents, [C] at least one accelerator; Including, [B-1] contains at least one aromatic amine compound, [B-2] contains an organic acid hydrazide compound having at least one aromatic ring structure, [C] is [C-1] at least one phosphonium salt; wherein the component [C-1] promotes the reaction between the component [A] and at least one curing agent, The component [A] is present in an amount of 100 parts by mass, the component [B-2] is present in an amount of 1 to 20 parts by mass, and the component [C-1] is present in an amount of 0.1 to 10 parts by mass, the equivalent ratio of all active hydrogens in the components [B-1] and [B-2] to all epoxy groups in the component [A] is 0.7 to 1.3; The epoxy resin composition satisfies (I), 5.0>|T １ -T ２ | (I) During the ceremony, T １ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-1], T ２ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-1], and [C]; The extrapolation start temperature T １ and T ２ is the mixture in which the equivalent ratio of all active hydrogens of [B-1] or [B-2] to all epoxy groups of [A] is 1.0, and the mass ratio of [C] to [A] is 1:

100. １ and T ２ A prepreg comprising reinforcing fiber bundles impregnated with an epoxy resin composition, characterized by differential scanning calorimetry of the mixture at a heating rate of 10° C. / min.

5. 1. A fiber-reinforced composite material comprising a cured article of an epoxy resin composition, the epoxy resin composition comprising: [A] at least one epoxy resin, [B] at least two curing agents, [B-1] At least one first curing agent; [B-2] at least one second curing agent different from the first curing agent; At least two curing agents, [C] at least one accelerator; Including, [B-1] contains at least one aromatic amine compound, [B-2] contains an organic acid hydrazide compound having at least one aromatic ring structure, [C] is [C-1] at least one phosphonium salt; wherein the component [C-1] promotes the reaction between the component [A] and at least one curing agent, The component [A] is present in an amount of 100 parts by mass, the component [B-2] is present in an amount of 1 to 20 parts by mass, and the component [C-1] is present in an amount of 0.1 to 10 parts by mass, the equivalent ratio of all active hydrogens in the components [B-1] and [B-2] to all epoxy groups in the component [A] is 0.7 to 1.3; The epoxy resin composition satisfies (I), 5.0>|T １ -T ２ | (I) During the ceremony, T １ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-1], T ２ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-1], and [C]; The extrapolation start temperature T １ and T ２ is the mixture in which the equivalent ratio of all active hydrogens of [B-1] or [B-2] to all epoxy groups of [A] is 1.0, and the mass ratio of [C] to [A] is 1:

100. １ and T ２ The mixture is determined by differential scanning calorimetry at a heating rate of 10° C. / min. A fiber reinforced composite material comprising a cured article of an epoxy resin composition.

6. The viscosity (V ２ The viscosity (V) of the epoxy resin composition was measured after holding at 80° C. for 1 minute. １ ) to the ratio (V ２ / V １ 3. The epoxy resin composition according to claim 1, wherein the β-

7. The viscosity ratio (V ２ / V １ 7. The epoxy resin composition according to claim 6, wherein the (R) is 2.0 or less.

8. The epoxy resin composition according to any one of claims 1 to 3, wherein the component [A] comprises at least one epoxy resin having three or more epoxy groups.

9. The epoxy resin composition according to any one of claims 1 to 3, wherein the component [A] comprises at least one compound selected from the group consisting of tetraglycidyldiaminodiphenylmethane, meta- or para-aminophenol epoxy resins, and bisnaphthalene epoxy resins.

10. The prepreg according to claim 4, wherein the component [A] comprises at least one compound selected from the group consisting of tetraglycidyldiaminodiphenylmethane, meta- or para-aminophenol epoxy resins, and bisnaphthalene epoxy resins.

11. The epoxy resin composition according to any one of claims 1 to 3, wherein the component [B-1] comprises 3,3'-diaminodiphenyl sulfone and / or 4,4'-diaminodiphenyl sulfone.

12. The prepreg according to claim 4 or 10, wherein the component [B-1] contains 3,3'-diaminodiphenyl sulfone and / or 4,4'-diaminodiphenyl sulfone.

13. The epoxy resin composition according to any one of claims 1 to 3, wherein an equivalent ratio of all active hydrogens in said component [B-1] to all active hydrogens in said component [B-2] is 1 to 10.

14. The epoxy resin composition according to claim 1 or 2, wherein the component [C] is at least one compound selected from the group consisting of triphenylphosphine, tetraphenylphosphonium bromide, triphenylphosphine triphenylborane, and tetrabutylammonium trifluoromethanesulfonate.

15. The epoxy resin composition according to claim 1 or claim 2, wherein the component [C] is present in an amount of 0.1 to 10 parts by mass per 100 parts by mass of the component [A].

16. 3. The epoxy resin composition according to claim 1, wherein component [A] is present in an amount of 100 parts by mass, component [B-2] is present in an amount of 1 to 20 parts by mass, and component [C] is present in an amount of 0.1 to 10 parts by mass, and the equivalent ratio of all active hydrogens in components [B-1] and [B-2] to all epoxy groups in component [A] is 0.7 to 1.

3.

17. 4. The epoxy resin composition according to claim 3, wherein the component [C-1] has a melting point of 220° C. or less when measured by differential scanning calorimetry at a heating rate of 10° C. / min.

18. The epoxy resin composition satisfies (V) and (VI), 5.0>|T １ -T ５ | (V), and 2.0>|T １ｐ -T ５ｐ | (VI), During the ceremony, T １ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A] and [B-1], T ５ is the extrapolated onset temperature (°C) in the reaction of a mixture of [A], [B-1], and [C-1], T １ｐ is the peak temperature (°C) in the reaction of the mixture of [A] and [B-1], T ５ｐ is the peak temperature (°C) in the reaction of the mixture of [A], [B-1] and [C-1], The extrapolation start temperature T １ and T ５ , and the peak temperature T １ｐ and T ５ｐ is determined by differential scanning calorimetry at a heating rate of 10° C. / min using the mixture in which the equivalent ratio of all active hydrogens of [B-1] or [B-2] to all epoxy groups of [A] is 1.0 and the mass ratio of [C-1] to [A] is 1:

100.

19. The epoxy resin composition according to claim 3, wherein the component [C-1] is at least one compound selected from the group consisting of triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(p-methoxyphenyl)phosphine, diphenylcyclohexylphosphine, and triphenylphosphine oxide.

20. The prepreg according to claim 4 or 10, wherein the component [C-1] is triphenylphosphine triphenylborane.

21. The epoxy resin composition according to any one of claims 1 to 3, further comprising at least one thermoplastic resin.

22. The epoxy resin composition according to claim 21, wherein the thermoplastic resin is present in an amount of 1 to 30 parts by mass per 100 parts by mass of the component [A].

23. A prepreg comprising reinforcing fiber bundles impregnated with the epoxy resin composition according to any one of claims 1 to 3.

24. A fiber-reinforced composite material obtained by curing the prepreg according to claim 4 or 10.

25. A fiber-reinforced composite material comprising an epoxy resin cured article obtained by curing a mixture containing the epoxy resin composition according to any one of claims 1 to 3 and reinforcing fibers.

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