JP2016147925A - Prepreg and fiber-reinforced composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber-reinforced composite material which exhibits stable mode I interlayer toughness and mode II interlayer toughness and has formability; an epoxy resin composition for obtaining the same; and a prepreg obtained by using the epoxy resin composition.SOLUTION: A prepreg is formed of: at least components [A] to [D] of [A] an epoxy resin, [B] a thermoplastic resin, [C] a solid amine curing agent having an amino group active hydrogen equivalent of 70(g/eq.) or more and 150(g/eq.) or less, and [D] thermoplastic resin particles which are insoluble in the epoxy resin and satisfy conditions (d1) to (d3): (d1) particle size distribution index of 1.0-1.8; (d2) sphericity of the particle of 85 or more; and (d3) glass transition temperature of the particles of 40-300°C; and a reinforced fiber.SELECTED DRAWING: None

Description

  The present invention relates to a prepreg from which a fiber-reinforced composite material having excellent interlayer toughness and moldability is obtained, and a fiber-reinforced composite material using the prepreg.

  Fiber reinforced composite materials, especially carbon fiber reinforced composite materials, are useful because they are excellent in specific strength and specific rigidity, and are useful for aircraft structural members, windmill blades, automobile outer plates, IC trays, and notebook PC housings (housings). ) And other computer applications, and the demand is increasing year by year.

  Carbon fiber reinforced composite material is a heterogeneous material formed by molding a prepreg composed of carbon fibers, which are reinforcing fibers, and a matrix resin as essential components. Therefore, the physical properties of the reinforcing fibers in the alignment direction and the physical properties in other directions There is a big difference. For example, it is known that interlayer toughness, which indicates the difficulty of progressing interlaminar fracture of reinforcing fibers, does not lead to drastic improvement only by improving the strength of the reinforcing fibers. In particular, a carbon fiber reinforced composite material using a thermosetting resin as a matrix resin reflects the low toughness of the matrix resin, and has a property of being easily broken by stress from other than the direction in which the reinforcing fibers are arranged. Therefore, while maintaining the compressive strength in the fiber direction under the high-temperature and high-humidity environment required for aircraft structural materials, the composite material properties that can cope with stresses from other than the array direction of reinforcing fibers including interlayer toughness Various techniques have been proposed for the purpose of improvement.

  Furthermore, in recent years, the application site of fiber reinforced composite materials for aircraft structural materials has expanded, and the application of fiber reinforced composite materials to wind turbine blades and various turbines aimed at improving power generation efficiency and energy conversion efficiency is also progressing. Studies are being made on application to thick members having a large number of laminated prepregs and members having a three-dimensional curved shape. When tensile stress or compressive stress is applied to such a thick member or curved member, an out-of-plane tearing stress occurs between the fiber layers, and cracks due to the opening mode occur between the layers. Due to the progress, the strength and rigidity of the entire member may decrease, leading to total destruction. In order to counter this stress, interlaminar toughness in the open mode, i.e. mode I, is required.

  As a technology to increase interlaminar toughness, a technology has been proposed in which mode II interlaminar toughness is enhanced by disposing particulate materials using high toughness polyamide in the fiber interlaminar region, and damage to the falling weight impact on the member surface is suppressed. (See Patent Document 1).

  However, when this technique is used, it is known that, in the mode I interlayer toughness test, the cracks that progress are separated from the layers and propagate in the fiber layer where particles are not present. In order to avoid such a crack transition in the layer, it is considered effective to ensure sufficient adhesion between the reinforcing fiber and the matrix resin and to improve the balance between the elastic modulus and toughness of the matrix resin. As a method for improving the toughness of the epoxy resin, a method of blending a rubber component or a thermoplastic resin having excellent toughness has been tried. As an example, a resin design that has been provided with toughness by blending a polysulfone having a low number average molecular weight has been developed (Patent Document 2). Specifically, it is disclosed that an excellent toughness improving effect can be obtained by blending polysulfone having a number average molecular weight of 3000 to 5100 in a large amount of 20 to 50% by mass of the epoxy resin composition.

US Pat. No. 5,028,478 JP 61-228016 A

  When molding large structural materials, it will be necessary to improve productivity with mass production. In other words, it is important that the prepreg laminating process is simple. For this purpose, for example, it is required that the adhesiveness of the prepreg is suppressed, the adjustment and correction of the laminating position are facilitated, or a plurality of layers can be laminated together. This also facilitates the production of thick fiber-reinforced composite materials that are in increasing demand in recent years.

  In the method of Patent Document 1, the mode I interlayer toughness is insufficient with respect to the properties required for the fiber reinforced composite material, and the prepreg has high adhesiveness and insufficient moldability. Here, when the viscosity of the resin composition is increased to suppress the tackiness, the impregnation property becomes insufficient, and it is difficult to satisfy the impregnation property while suppressing the tackiness of the prepreg.

  Further, in the method of Patent Document 2, the mode II interlayer toughness may be insufficient for the characteristics required for the fiber reinforced composite material, and the prepreg has high adhesiveness and the molding workability is insufficient.

  As described above, it has been difficult to develop a prepreg and a fiber-reinforced composite material satisfying the mode I interlayer toughness, the mode II interlayer toughness, and the moldability.

  Then, the objective of this invention is providing the prepreg from which the fiber reinforced composite material which has mode I interlayer toughness, mode II interlayer toughness, and shaping | molding workability | operativity is obtained, and a fiber reinforced composite material using the same.

In order to achieve the above object, the present invention has any one of the following configurations. That is, at least the following components [A], [B], [C], [D] and a prepreg composed of reinforcing fibers.
[A] Epoxy resin [B] Thermoplastic resin [C] Solid amine curing agent having an amino group active hydrogen equivalent weight of 70 (g / eq.) Or more and 150 (g / eq.) Or less [D] Next (d1) to (D3) Thermoplastic resin particles insoluble in epoxy resin that satisfy the condition (d3) (d1) Particle size distribution index is 1.0 to 1.8 (d2) Particles having a sphericity of 85 or more (d3) particles Has a glass transition temperature of 40 to 300 ° C.

  Furthermore, in this invention, it can be set as the fiber reinforced composite material formed by hardening | curing the said prepreg.

  ADVANTAGE OF THE INVENTION According to this invention, the fiber reinforced composite material which expressed the mode I interlayer toughness and the mode II interlayer toughness stably, and has moldability, and the epoxy resin composition and prepreg for fiber reinforced composite materials for obtaining this Is obtained.

  Hereinafter, the prepreg and fiber-reinforced composite material of the present invention will be described in detail.

The prepreg of the present invention comprises an epoxy resin [A], a thermoplastic resin [B], a solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) To 150 (g / eq.), This is a prepreg composed of thermoplastic resin particles [D] insoluble in epoxy resin and reinforcing fibers, and [D] satisfies the following conditions (d1) to (d3).
(D1) The particle size distribution index is 1.0 to 1.8 (d2) The sphericity of the particle is 85 or more (d3) The glass transition temperature of the particle is 40 to 300 ° C.

  The epoxy resin [A] used in the present invention means a compound having two or more epoxy groups in one molecule.

  Specific examples of the epoxy resin [A] used in the present invention include aromatic glycidyl ether obtained from phenol having a plurality of hydroxyl groups, aliphatic glycidyl ether obtained from alcohol having a plurality of hydroxyl groups, glycidyl amine obtained from amine, carboxyl Examples thereof include a glycidyl ester obtained from a carboxylic acid having a plurality of groups and an epoxy resin having an oxirane ring. Among them, a glycidylamine type epoxy resin can be suitably used because of its low viscosity, excellent impregnation into reinforcing fibers, and excellent mechanical properties such as heat resistance and elastic modulus when used as a fiber reinforced composite material. Such glycidylamine type epoxy resins can be broadly classified into polyfunctional amine type epoxy resins and bifunctional amine type epoxy resins.

  Such a polyfunctional amine type epoxy resin refers to an amine type epoxy resin containing three or more epoxy groups in one molecule of the epoxy resin. Examples of such polyfunctional amine-type epoxy resins include tetraglycidyldiaminodiphenylmethane, tetraglycidyldiaminodiphenylsulfone, tetraglycidylxylylenediamine, triglycidylaminophenol, triglycidylaminocresol, halogen substituted products thereof, alkyl substituted products, Aralkyl-substituted, allyl-substituted, alkoxy-substituted, aralkoxy-substituted, allyloxy-substituted, hydrogenated and the like can be used.

  Such polyfunctional amine-type epoxy resin is not particularly limited, but tetraglycidyldiaminodiphenylmethane, tetraglycidyldiaminodiphenylsulfone, tetraglycidylxylylenediamine, triglycidylaminophenol, triglycidylaminocresol and its substitute, hydrogenated The body and the like are preferably used.

  Commercially available products of tetraglycidyldiaminodiphenylmethane include “Sumiepoxy (registered trademark)” ELM434 (manufactured by Sumitomo Chemical Co., Ltd.), YH434L (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), “jER (registered trademark)” 604 ( (Mitsubishi Chemical Corporation), “Araldide (registered trademark)” MY720, “Araldide (registered trademark)” MY721, “Araldide (registered trademark)” MY9512, “Araldide (registered trademark)” MY9663 (above, Huntsman Advanced Materials, Inc.) can be used.

  Examples of commercially available tetraglycidyl diaminodiphenyl sulfone include TG3DAS (manufactured by Mitsui Chemicals Fine Co., Ltd.).

  Examples of commercially available tetraglycidylxylylenediamine and hydrogenated products thereof include “TETRAD (registered trademark)”-X, “TETRAD (registered trademark)”-C (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and the like. .

  Commercially available products of triglycidylaminophenol or triglycidylaminocresol include “Sumiepoxy (registered trademark)” ELM100, “Sumiepoxy (registered trademark)” ELM120 (manufactured by Sumitomo Chemical Co., Ltd.), “Araldide (registered trademark)” “MY0500”, “Araldide (registered trademark)” MY0510, “Araldide (registered trademark)” MY0600 (manufactured by Huntsman Advanced Materials), “jER (registered trademark)” 630 (manufactured by Mitsubishi Chemical Corporation), etc. Is mentioned.

  Examples of the bifunctional amine type epoxy resin include diglycidyl aniline, diglycidyl toluidine, and halogen-substituted products, alkyl-substituted products, and hydrogenated products thereof.

  Examples of commercially available diglycidyl aniline include GAN (manufactured by Nippon Kayaku Co., Ltd.) and PxGAN (manufactured by Toray Fine Chemical Co., Ltd.).

  Examples of commercially available diglycidyl toluidine include GOT (manufactured by Nippon Kayaku Co., Ltd.).

  In this invention, it is preferable that 20-100 mass parts of amine type epoxy resins are contained in 100 mass parts of total amounts of epoxy resin [A], More preferably, it is the range of 30-100 mass parts. When the amine-type epoxy resin is less than 20 parts by mass with respect to 100 parts by mass of the total amount of the epoxy resin blended, heat resistance and compressive strength when used as a fiber-reinforced composite material may be insufficient.

  The epoxy resin [A] in the present invention may contain an epoxy resin other than a glycidylamine type epoxy resin, a copolymer of an epoxy resin and a thermosetting resin, or the like. Examples of the thermosetting resin used by being copolymerized with an epoxy resin include unsaturated polyester resins, vinyl ester resins, benzoxazine resins, phenol resins, urea resins, melamine resins, and polyimide resins. These resin compositions and compounds may be used alone or in combination as appropriate.

  Examples of epoxy resins other than glycidylamine type epoxy resins include phenol novolac type epoxy resins, cresol novolac type epoxy resins, resorcinol type epoxy resins, dicyclopentadiene type epoxy resins, urethane and isocyanate modified epoxy resins, and epoxy resins having a biphenyl skeleton. As the epoxy resin having a fluorene skeleton and the bisphenol type epoxy resin, bisphenol A type, bisphenol F type, bisphenol S type, bisphenol AD type, halogens of these bisphenols, alkyl-substituted products, hydrogenated products, and the like are used. These resin compositions and compounds may be used alone or in combination as appropriate.

  Commercial products of phenol novolac type epoxy resins include “jER (registered trademark)” 152, “jER (registered trademark)” 154 (manufactured by Mitsubishi Chemical Corporation), “Epicron (registered trademark)” N-740, "Epiclon (registered trademark)" N-770, "Epiclon (registered trademark)" N-775 (manufactured by DIC Corporation), and the like.

  Examples of commercially available cresol novolac epoxy resins include “Epicron (registered trademark)” N-660, “Epicron (registered trademark)” N-665, “Epicron (registered trademark)” N-670, and “Epicron (registered trademark)”. “N-673”, “Epicron (registered trademark)” N-695 (above, manufactured by DIC Corporation), EOCN-1020, EOCN-102S, EOCN-104S (above, manufactured by Nippon Kayaku Co., Ltd.) It is done.

  Specific examples of the resorcinol type epoxy resin include “Denacol (registered trademark)” EX-201 (manufactured by Nagase ChemteX Corporation).

  Commercially available dicyclopentadiene type epoxy resins include “Epicron (registered trademark)” HP7200, “Epicron (registered trademark)” HP7200L, “Epicron (registered trademark)” HP7200H (above, manufactured by DIC Corporation), “Tactix” (Registered trademark) "558 (manufactured by Huntsman Advanced Material), XD-1000-1L, XD-1000-2L (manufactured by Nippon Kayaku Co., Ltd.), and the like.

  Examples of commercially available urethane and isocyanate-modified epoxy resins include AER4152 (produced by Asahi Kasei E-Materials Co., Ltd.) having an oxazolidone ring and ACR1348 (produced by Asahi Denka Co., Ltd.).

  Commercially available epoxy resins having a biphenyl skeleton include “jER (registered trademark)” YX4000H, “jER (registered trademark)” YX4000, “jER (registered trademark)” YL6616 (manufactured by Mitsubishi Chemical Corporation), NC -3000 (manufactured by Nippon Kayaku Co., Ltd.).

  Commercially available epoxy resins having a fluorene skeleton include ESF300 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), “Oncoat (registered trademark)” EX-1010, “Oncoat (registered trademark)” EX-1011, “ "ONCOAT (registered trademark)" EX-1012, "ONCOAT (registered trademark)" EX-1020, "ONCOAT (registered trademark)" EX-1030, "ONCOAT (registered trademark)" EX-1040, "ONCOAT (Registered Trademark) “EX-1050”, “On Coat (Registered Trademark)” EX-1051 (manufactured by Nagase ChemteX Corporation) and the like.

  Commercially available bisphenol A type epoxy resins include “Epototo (registered trademark)” YD128 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), “jER (registered trademark)” 825, “jER (registered trademark)” 828, “ jER (registered trademark) 834, jER (registered trademark) 1001, jER (registered trademark) 1004, jER (registered trademark) 1007, jER (registered trademark) 1009, jER (registered trademark) "1010 (above, manufactured by Mitsubishi Chemical Corporation)".

  Commercially available products of bisphenol F type epoxy resin include “Epiclon (registered trademark)” 830, “Epiclon (registered trademark)” 835 (manufactured by DIC Corporation), “jER (registered trademark)” 806, “jER (registered trademark)” ) “807”, “jER (registered trademark)” 4004P, “jER (registered trademark)” 4007P, “jER (registered trademark)” 4009P, “jER (registered trademark)” 4010P (manufactured by Mitsubishi Chemical Corporation), “Epototo (registered trademark)” YDF170, “Epototo (registered trademark)” YDF2001 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and the like.

  Examples of the bisphenol S-type epoxy resin include “Epiclon (registered trademark)” EXA-1514 (manufactured by DIC Corporation).

  Examples of the bisphenol AD type epoxy resin include “EPOMIK (registered trademark)” R710, “EPOMIK (registered trademark)” R1710 (manufactured by Printec Co., Ltd.), and the like.

  Furthermore, in this invention, a monofunctional epoxy resin can also be used in the meaning which improves the balance of the elasticity modulus and elongation of a resin cured material.

  As the monofunctional epoxy resin, “Denacol (registered trademark)” Ex-731 (glycidylphthalimide, manufactured by Nagase ChemteX Corporation), OPP-G (o-phenylphenylglycidyl ether, manufactured by Sanko Co., Ltd.), Ex- 141 (phenylglycidyl ether, manufactured by Nagase ChemteX Corporation), Ex-146 (tert-butylphenylglycidyl ether, manufactured by Nagase ChemteX Corporation), and the like.

  The epoxy resin composition of the present invention is used by mixing or dissolving the thermoplastic resin [B].

  In the present invention, by combining the thermoplastic resin [B] with the above epoxy resin [A], high toughness can be obtained while avoiding a decrease in heat resistance, and the mode I interlayer toughness of the fiber reinforced composite material is greatly increased. improves.

  The thermoplastic resin [B] of the present invention is a polymer material that is in a crystalline state or a glass state at room temperature and has thermoplasticity.

  The thermoplastic resin [B] generally has a group consisting of a carbon-carbon bond, an amide bond, an imide bond, an ester bond, an ether bond, a carbonate bond, a urethane bond, a thioether bond, a sulfone bond and a carbonyl bond in the main chain. A thermoplastic resin having a bond selected from: Further, this thermoplastic resin [B] may have a partially crosslinked structure, and may have crystallinity or may be amorphous. In particular, polyamide, polycarbonate, polyacetal, polyphenylene oxide, polyphenylene sulfide, polyarylate, polyester, polyamideimide, polyimide, polyetherimide, polyimide having phenyltrimethylindane structure, polysulfone, polyethersulfone, polyetherketone, polyetherether It is preferable that at least one resin selected from the group consisting of ketones, polyaramids, polyether nitriles, and polybenzimidazoles is dissolved in any of the epoxy resins included in the epoxy resin composition.

  It is preferable that the weight average molecular weight of the thermoplastic resin [B] of this invention exists in the range of 4000-50000 g / mol, More preferably, it is 10000-40000 g / mol, More preferably, it is 15000-30000 g / mol. When the weight average molecular weight is lower than 4000 g / mol, the mode I interlayer toughness of the fiber reinforced composite material may be insufficient. Moreover, when higher than 50000 g / mol, when a thermoplastic resin is melt | dissolved in an epoxy resin composition, the viscosity of an epoxy resin will become high and kneading | mixing will become difficult and prepreg may become difficult.

  The glass transition temperature of the thermoplastic resin [B] of the present invention is preferably 150 ° C. or higher, more preferably 200 ° C. or higher, and further preferably 220 ° C. or higher. When the glass transition temperature of the thermoplastic resin [B] is less than 150 ° C., the molded body may easily undergo thermal deformation.

  In the present invention, the thermoplastic resin [B] is contained in the epoxy resin composition in an amount of 8 to 40% by mass, preferably 12 to 35% by mass, and more preferably 20 to 30% by mass. When it is less than 8% by mass, the mode I interlayer toughness of the obtained fiber-reinforced composite material is insufficient. Moreover, when it exceeds 40 mass%, the viscosity of a thermosetting resin composition will rise, the manufacturing process property and handleability of a thermosetting resin composition and a prepreg will become inadequate, and impregnation property will also deteriorate.

  Examples of the thermoplastic resin [B] include polycarbonate (glass transition temperature: 150 ° C.), polysulfone (glass transition temperature: 190 ° C.), polyetherimide (glass transition temperature: 215 ° C.), and polyether sulfone (glass transition temperature: 225 ° C.).

  Furthermore, as a terminal functional group of this thermoplastic resin [B], things, such as a hydroxyl group, a carboxyl group, an amino group, a thiol group, and an acid anhydride, can react with a cationically polymerizable compound, and are used preferably. Examples of the thermoplastic resin having a hydroxyl group include polyvinyl acetal resins such as polyvinyl formal and polyvinyl butyral, polyvinyl alcohol, and phenoxy resins. Moreover, polyethersulfone can be mentioned as a thermoplastic resin which has a sulfonyl group.

  Specifically, as a commercially available product of polycarbonate, “Panlite (registered trademark)” K1300Y (manufactured by Teijin Chemicals Ltd.) and the like can be mentioned.

  Commercially available products of polysulfone include “UDEL (registered trademark)” P-1700, “UDEL (registered trademark)” P-3500 (manufactured by Teijin Amoco), “Virantage (registered trademark)” VW-30500RP (Solvay Advanced). Polymers).

  Examples of commercially available polyetherimides include “Ultem (registered trademark)” 1000, “Ultem (registered trademark)” 1010, “Ultem (registered trademark)” 1040 (manufactured by Solvay Advanced Polymers), and the like.

  Commercially available polyethersulfone products include “Sumika Excel (registered trademark)” PES3600P, “Sumika Excel (registered trademark)” PES5003P, “Sumika Excel (registered trademark)” PES5200P, “Sumika Excel (registered trademark)” PES7600P (and above) , Manufactured by Sumitomo Chemical Co., Ltd.), "Ultrason (registered trademark)" E2020P SR, "Ultrason (registered trademark)" E2021SR (above, manufactured by BASF), "GAFONE (registered trademark)" 3600RP, "GAFONE (registered trademark) ) “3000RP”, “Virantage (registered trademark)” VW-10700RP (manufactured by Solvay Advanced Polymers) and the like.

  In the present invention, the solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) To 150 (g / eq.) Is a curing of the epoxy resin contained in the epoxy resin composition of the present invention. It is a compound having active hydrogen that can react with an epoxy group. In addition, solid means here that it does not have fluidity | liquidity at normal temperature (25 degreeC), and is solid.

  In the present invention, the amino group active hydrogen equivalent of the solid amine curing agent [C] needs to be 70 (g / eq.) Or more and 150 (g / eq.) Or less, preferably 85 (g / eq.) Or more. It is preferably 110 (g / eq.) Or less. When the amino group active hydrogen equivalent is less than 70 (g / eq.), The mode I interlayer toughness of the fiber reinforced composite material may be insufficient, and the amount of powder blended in the epoxy resin composition is small. Therefore, the moldability is also lowered because the viscosity is lowered. On the other hand, when it exceeds 150 (g / eq.), The amount of the powder blended in the epoxy resin composition increases and the viscosity becomes high, so that prepregation becomes difficult.

  Examples of commercially available solid amine curing agents having an amino group active hydrogen equivalent weight of 70 (g / eq.) Or more and 150 (g / eq.) Or less include 1-N, 4-N-bis (4-aminophenyl) phenylene- 1,4-dicarboxamide (4-APTP) (amino group active hydrogen equivalent: 87), 4-amino-N- [4-[(4-aminobenzoyl) amino] phenyl] benzamide (4-ABPA) (amino Group active hydrogen equivalent: 87) (Nippon Pure Chemicals Co., Ltd.), 9,9-bis (4-aminophenyl) fluorene (amino group active hydrogen equivalent: 87) (JFE Chemical Co., Ltd.), “ Lonzacure (registered trademark) “M-DEA (amino group active hydrogen equivalent: 78),“ Lonzacure (registered trademark) ”M-MIPA (amino group active hydrogen equivalent: 78),“ Lonzacure ( "M-DIPA (amino group active hydrogen equivalent: 94)", "Lonzacure (registered trademark)" M-CDEA (amino group active hydrogen equivalent: 95), "Lonzacure (registered trademark)" M-CDEA gs (amino) Group active hydrogen equivalent: 95) (above, manufactured by Lonza), 4,4′-bis (p-aminophenoxy) biphenyl (BAPB) (amino group active hydrogen equivalent: 92), 9,9-bis (4-amino) -3-chlorophenyl) fluorene (amino group active hydrogen equivalent: 104) (manufactured by Tokyo Chemical Industry Co., Ltd.).

  Among these, 9,9-bis (4-aminophenyl) fluorene or 9,9-bis (4-amino-3-chlorophenyl) fluorene is preferably used. Since 9,9-bis (4-aminophenyl) fluorene or 9,9-bis (4-amino-3-chlorophenyl) fluorene can obtain a fiber-reinforced composite material having good heat resistance and mode II interlayer toughness. Preferably used.

  In the present invention, the melting point of the solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) Or more and 150 (g / eq.) Or less is preferably 80 ° C. or more and 330 ° C. or less. Preferably they are 100 degreeC or more and 300 degrees C or less, More preferably, they are 180 degreeC or more and 250 degrees C or less. When the melting point is less than 80 ° C., the curing reaction may proceed while the prepreg is stored at room temperature, and the storage stability of the prepreg deteriorates. On the other hand, when it exceeds 330 ° C., the curing agent becomes difficult to melt at the curing temperature of the prepreg, so that the curing reaction does not proceed sufficiently and may result in poor curing.

  The addition amount of the solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) Or more and 150 (g / eq.) Or less is the total curing agent component with respect to all the epoxy groups in the epoxy resin composition. The total equivalent ratio of the active hydrogens of the amino groups is 0.7 to 1.3, and 30% or more of the active hydrogens of the amino groups of all the curing agent components has an amino group active hydrogen equivalent of 70 (g / eq.) to 150 (g / eq.) or less of the active amine of the amino group of the solid amine curing agent [C], a fiber-reinforced composite material excellent in heat resistance and mechanical properties can be obtained, and in a preferred embodiment is there. When the amount of the solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) Or more and 150 (g / eq.) Or less is small in the epoxy resin composition, the toughness of the cured epoxy resin product The improvement effect is small and the improvement effect of the mode I interlayer toughness and the mode II interlayer toughness of the obtained fiber reinforced composite material may be small. There is a possibility. Therefore, the compounding amount of the solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) Or more and 150 (g / eq.) Or less is the total curing with respect to all the epoxy groups in the epoxy resin composition. It is preferable that the equivalent ratio of the total amount of active hydrogen of the amino group of the agent component is 0.7 to 1.3, more preferably 0.8 to 1.2, and the amino group of all the curing agent components Of the active hydrogens, 30% or more is preferably used as the active hydrogen of the amino group of the solid amine curing agent [C] having an amino group active hydrogen equivalent of 70 (g / eq.) To 150 (g / eq.). More preferably, it is 50% or more.

  In the present invention, a curing agent other than the solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) To 150 (g / eq.) May be used in combination. Examples of the curing agent other than the solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) Or more and 150 (g / eq.) Or less include, for example, dicyandiamide, aromatic amine curing agent, and aminobenzoic acid. Esters, various acid anhydrides, phenol novolac resins, cresol novolac resins, polyphenol compounds, imidazole derivatives, aliphatic amines, tetramethylguanidine, thiourea addition amines, carboxylic acid anhydrides such as methylhexahydrophthalic anhydride, Examples thereof include Lewis acid complexes such as carboxylic acid hydrazide, carboxylic acid amide, polymercaptan, and boron trifluoride ethylamine complex. Among these, an aromatic amine curing agent is preferably used because an epoxy resin cured product having excellent heat resistance and mechanical properties can be obtained. As an aromatic amine curing agent, it is particularly possible to use diaminodiphenyl sulfone together with a solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) To 150 (g / eq.). The fiber-reinforced composite material is a preferred embodiment because it can exhibit high heat resistance and tensile strength, as well as compressive strength.

  Commercially available aromatic amine curing agents include 4,4′-DABAN, 3,4′-DABAN (above, manufactured by Nippon Pure Chemicals Co., Ltd.), Seika Cure S (manufactured by Wakayama Seika Kogyo Co., Ltd.), MDA -220 (Mitsui Chemicals Polyurethanes Co., Ltd.), “jER Cure (registered trademark)” W (Mitsubishi Chemical Co., Ltd.), 3,3′-DAS (Mitsui Chemicals Fine Co., Ltd.), etc. .

  Further, the solid amine curing agent [C] having an epoxy resin and amino group active hydrogen equivalent of 70 (g / eq.) Or more and 150 (g / eq.) Or less, or an amino group active hydrogen equivalent of 70 (g / eq.). Curing agents other than the solid amine curing agent [C] of 150 (g / eq.) Or less, or those obtained by pre-reacting a part thereof can be blended in the composition. This method may be effective for viscosity adjustment and storage stability improvement.

The thermoplastic resin particles [D] insoluble in the epoxy resin in the present invention must satisfy the following conditions (d1) to (d3).
(D1) The particle size distribution index is 1.0 to 1.8 (d2) The sphericity of the particle is 85 or more (d3) The glass transition temperature of the particle is 40 to 300 ° C. Here, the epoxy resin The term “insoluble in” means that the resin particles are not substantially dissolved in the epoxy resin when the epoxy resin in which the resin particles are dispersed is heated and cured. For example, using a transmission electron microscope, In the cured resin, the particles can be observed with a clear interface between the particles and the matrix resin without substantially reducing the original size.

  Moreover, the thermoplastic resin particle [D] in the present invention needs to have a particle size distribution index of 1.0 to 1.8, and preferably 1.1 to 1.5. In such a fiber reinforced composite material obtained by laminating a prepreg in which the epoxy resin composition in which the resin particles are dispersed and the reinforcing fiber are combined and heat-curing by setting such a relatively narrow particle size distribution, the reinforcing fiber layer Without interstitial resin particles, and with the presence of some coarse particles, there is no region with excessive interlayer thickness, and it has a uniform interlayer thickness, stable mode I interlayer toughness and mode II interlayer toughness Can be obtained. When the particle size distribution index exceeds 1.8, some fine resin particles enter the reinforcing fiber layer, resulting in a decrease in mode I interlayer toughness, mode II interlayer toughness and compressive strength during wet heat, and interlayer thickness. Due to the occurrence of unevenness, the material has a large variation in these characteristics.

  The particle size distribution index is determined based on the following numerical conversion formula for the value of the particle diameter obtained by the method described later.

  Ri: particle diameter of each particle, n: number of measurement 100, Dn: number average particle diameter, Dv: volume average particle diameter, PDI: particle diameter distribution index.

  Further, the thermoplastic resin particles [D] in the present invention need to have a sphericity of 85 or more, preferably 92 or more, more preferably 96 or more, and most preferably 98 or more. . By setting such high sphericity, the viscosity of the epoxy resin composition in which the thermoplastic resin particles are dispersed can be kept low, and the amount of the thermoplastic resin particles can be increased accordingly. Therefore, mode I interlayer toughness and mode II interlayer toughness are improved. When the sphericity is less than 85, the amount of resin particles is limited due to the increase in viscosity of the epoxy resin composition, and the material becomes insufficient in mode I interlayer toughness and mode II interlayer toughness.

  The sphericity is calculated by observing particles with a scanning electron microscope, measuring the minor axis and the major axis, and calculating the average of 30 arbitrary particles according to the following numerical conversion formula.

  Moreover, the thermoplastic resin particle [D] in the present invention needs to have a glass transition temperature in the range of 40 to 300 ° C, preferably in the range of 80 to 220 ° C, and in the range of 120 to 160 ° C. It is more preferable. By using such a relatively high glass transition temperature, the resin particles are not deformed during heat curing, a stable interlayer thickness is formed, and a fiber reinforced composite having excellent mode I interlayer toughness and mode II interlayer toughness. It becomes possible to obtain a material. When such a glass transition temperature is less than 40 ° C., a fiber-reinforced composite material having insufficient compressive strength during wet heat may be obtained, and stability at room temperature storage may not be ensured. On the other hand, when the glass transition temperature exceeds 300 ° C., the fiber-reinforced composite material has a tendency that the toughness of the resin particles themselves is insufficient and the interfacial adhesion between the resin particles and the matrix resin is insufficient and the interlayer toughness is insufficient. It becomes.

  Such a glass transition temperature is measured by using a differential scanning calorimetry (DSC method) from 30 ° C. to a temperature higher than the predicted glass transition temperature by 30 ° C. or higher under a temperature rising condition of 20 ° C./min. Glass transition observed when the temperature is raised and held for 1 minute, then cooled to 0 ° C. under a temperature drop condition of 20 ° C./minute, held for 1 minute, and then measured again under a temperature rise condition of 20 ° C./minute. It is temperature.

  The thermoplastic resin particles [D] in the present invention preferably have an average particle diameter in the range of 5 to 50 μm, and more preferably in the range of 10 to 30 μm. In the fiber reinforced composite material obtained by laminating a prepreg in which the epoxy resin composition in which the resin particles are dispersed and the reinforcing fiber are combined and heat-curing, the average particle diameter is in such a range. The fiber reinforced composite material having a uniform interlayer thickness can be obtained without causing resin particles to enter and without the presence of coarse particles, resulting in a mode I interlayer toughness. And Mode II interlayer toughness is stable and high.

  As the thermoplastic resin particle [D] in the present invention, specifically, vinyl polymer, polyester, polyamide, polyarylene ether, polyarylene sulfide, polyethersulfone, polysulfone, polyetherketone, polyetheretherketone, Examples thereof include polyurethane, polycarbonate, polyamideimide, polyimide, polyetherimide, polyacetal, silicone, and copolymers thereof. One or more of the above-described resins can be used.

  Among these, polyamide is preferably used because of its high elongation, toughness, and high adhesion to the matrix resin. Examples of the polyamide include polyamides obtained by polycondensation of a lactam having three or more members, a polymerizable aminocarboxylic acid, a dibasic acid and a diamine or a salt thereof, or a mixture thereof.

  Examples of polyamides having a glass transition temperature in the range of 40 ° C. to 300 ° C. include polycapramide (nylon 6), polyhexamethylene terephthalamide (nylon 6T), polynonane terephthalamide (nylon 9T), polydodecamide (nylon 12), Polyhexamethylene adipamide (nylon 66), poly-m-xylene adipamide (nylon MXD), 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, isophthalic acid and 12-aminododecanoic acid Polymer (for example, “Grillamide (registered trademark)” TR55, manufactured by Mzavelke), copolymer of 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane and dodecadioic acid (for example, "Grillamide (registered trademark)" TR90, manufactured by Mzavelke), 3, A copolymer of '-dimethyl-4,4'-diaminodicyclohexylmethane, isophthalic acid and 12-aminododecanoic acid, and a copolymer of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and dodecadioic acid; A mixture of 4,4′-diaminodicyclohexylmethane and dodecadioic acid (for example, “TROGAMID® for example”) "CX7323, manufactured by Degussa).

  In particular, in addition to impact resistance, mode I interlayer toughness and mode II interlayer toughness when used as a fiber reinforced composite material, a fiber reinforced composite material having excellent wet heat resistance and solvent resistance can be obtained. It is preferable that it is a polyamide containing the chemical structure of 1).

(Wherein R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a halogen element, and may be the same or different. R ₃ is a methylene having 1 to 20 carbon atoms) Group or a phenylene group).

  Examples of such a polyamide include a copolymer of 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, isophthalic acid and 12-aminododecanoic acid (for example, “Grillamide®” TR55, Mzavelke), 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane and dodecadioic acid copolymer (for example, “Grillamide (registered trademark)” TR90, manufactured by Mzavelke), 3, Copolymer of 3'-dimethyl-4,4'-diaminodicyclohexylmethane, isophthalic acid and 12-aminododecanoic acid, and copolymer of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and dodecanedioic acid (For example, “Grillamide (registered trademark)” TR70LX, manufactured by Mzavelke), 4,4′-di (By way of example, "TROGAMID (registered trademark)" CX7323, manufactured by Degussa) amino copolymer of dicyclohexylmethane and dodeca diacid and the like.

  The epoxy resin composition of the present invention is a coupling agent, a thermosetting resin particle, a thermoplastic resin that can be dissolved in an epoxy resin, or silica gel, carbon black, clay, carbon nanotube, as long as the effects of the present invention are not hindered. An inorganic filler such as a metal powder can be blended.

  The prepreg of the present invention is obtained by impregnating reinforcing fibers with the above epoxy resin composition for fiber reinforced composite materials. As the reinforcing fiber used in the prepreg of the present invention, carbon fiber, glass fiber, aramid fiber, boron fiber, PBO fiber, high strength polyethylene fiber, alumina fiber, silicon carbide fiber, and the like can be used. Two or more kinds of these fibers may be mixed and used. The form and arrangement of the reinforcing fibers are not limited, and for example, fiber structures such as long fibers arranged in one direction, a single tow, a woven fabric, a knit, a non-woven fabric, a mat and a braid are used.

  In particular, in applications where there is a high demand for weight reduction and high strength of materials, carbon fibers can be suitably used because of their excellent specific modulus and specific strength.

  The carbon fiber preferably used in the present invention may be any type of carbon fiber depending on the application, but is a carbon fiber having a tensile elastic modulus of 400 GPa at the highest in terms of interlayer toughness and impact resistance. It is preferable. From the viewpoint of strength, a carbon fiber having a tensile strength of preferably 4.4 to 6.5 GPa is preferably used because a composite material having high rigidity and mechanical strength can be obtained. Further, the tensile elongation is also an important factor, and it is preferably a high-strength, high-stretch carbon fiber of 1.7 to 2.3%. Accordingly, carbon fibers having the characteristics that the tensile modulus is at least 230 GPa, the tensile strength is at least 4.4 GPa, and the tensile elongation is at least 1.7% are most suitable.

  Commercially available carbon fibers include "Torayca (registered trademark)" T800G-24K, "Torayca (registered trademark)" T800S-24K, "Torayca (registered trademark)" T700G-24K, and "Torayca (registered trademark)" T300- 3K, and “Torayca (registered trademark)” T700S-12K (manufactured by Toray Industries, Inc.).

  The form and arrangement of the carbon fibers can be appropriately selected from long fibers and woven fabrics arranged in one direction. However, in order to obtain a carbon fiber reinforced composite material that is lighter and more durable, It is preferably in the form of continuous fibers such as long fibers (fiber bundles) or woven fabrics arranged in one direction.

  The prepreg of the present invention is preferably obtained by impregnating carbon fiber with an epoxy resin composition for fiber-reinforced composite material, and the carbon fiber mass fraction of the prepreg is preferably 40 to 90% by mass, more preferably It is 50-80 mass%. If the carbon fiber mass fraction is too low, the mass of the resulting composite material may be excessive, which may impair the advantages of the fiber-reinforced composite material having excellent specific strength and specific elastic modulus, and the carbon fiber mass fraction may be high. If the amount is too high, poor impregnation of the resin composition occurs, and the resulting composite material tends to have a large amount of voids, and its mechanical properties may be greatly deteriorated.

  In the prepreg of the present invention, it is preferable that 90 to 100% by mass is present within a depth range of 20% of the thickness of the prepreg from the prepreg surface with respect to 100% by mass of the thermoplastic resin particles. 90% or more of the thermoplastic resin particles are present within the depth range of 20% of the thickness of the prepreg from the prepreg surface, so that the thermoplastic resin particles enter the prepreg layer in the obtained fiber-reinforced composite material. It can be localized between the layers, and can exhibit high interlayer toughness.

  By adopting such a structure, when a prepreg is laminated and an epoxy resin is cured to form a carbon fiber reinforced composite material, an interlayer is easily formed, thereby improving the adhesion and adhesion between the composite material layers. As a result, the resulting carbon fiber reinforced composite material exhibits a high degree of interlayer toughness and impact resistance.

  The abundance of the particles can be evaluated by, for example, the following method. That is, the prepreg is sandwiched between two smooth polytetrafluoroethylene resin plates with a smooth surface, and the temperature is gradually raised to the curing temperature over 7 days to gel and cure to cure the plate-like prepreg. Make a thing. Two lines parallel to the surface of the prepreg are drawn on both surfaces of the prepreg cured product from the surface of the prepreg cured product at a depth of 20% of the thickness. Next, the total area of the particles existing between the surface of the prepreg and the line and the total area of the particles existing over the thickness of the prepreg are obtained, and from the surface of the prepreg with respect to 100% of the thickness of the prepreg. Calculate the abundance of particles present in the 20% depth range. Here, the total area of the particles is obtained by cutting out the particle portion from the cross-sectional photograph and converting it from the mass. If it is difficult to discriminate the particles dispersed in the resin after photography, a means for dyeing the particles can also be employed.

  The prepreg of the present invention can be produced by applying a method as disclosed in JP-A-1-26651, JP-A-63-170427 or JP-A-63-170428. Specifically, the prepreg of the present invention is a method of applying thermoplastic resin particles in the form of particles on the surface of a primary prepreg composed of carbon fiber and an epoxy resin that is a matrix resin, and in an epoxy resin that is a matrix resin. A method in which a mixture in which these particles are uniformly mixed is prepared, and in the process of impregnating the mixture into carbon fibers, the infiltration of these particles by blocking the reinforcing fibers is used to localize the particles on the surface portion of the prepreg, or in advance epoxy A primary prepreg is produced by impregnating a resin with carbon fiber, and a thermosetting resin film containing these particles at a high concentration is attached to the surface of the primary prepreg. When the thermoplastic resin particles are uniformly present in a depth range of 20% of the thickness of the prepreg, a prepreg for a fiber composite material having high interlayer toughness can be obtained.

  The prepreg of the present invention comprises a wet method in which the epoxy resin composition of the present invention is dissolved in a solvent such as methyl ethyl ketone and methanol to lower the viscosity and impregnated into a reinforcing fiber, and the epoxy resin composition is heated to lower the viscosity and strengthened. It can be suitably produced by a hot melt method for impregnating fibers.

  The wet method is a method of obtaining a prepreg by immersing a reinforcing fiber in a solution of an epoxy resin composition, then pulling it up and evaporating the solvent using an oven or the like.

  The hot melt method is a method in which a reinforcing fiber is impregnated directly with an epoxy resin composition whose viscosity has been reduced by heating, or a resin film in which an epoxy resin composition is coated on release paper or the like is prepared, and then a reinforcing fiber is prepared. This is a method of obtaining a prepreg by transferring and impregnating the epoxy resin composition by overlapping the resin film from both sides or one side and heating and pressurizing. This hot melt method is a preferred embodiment because substantially no solvent remains in the prepreg.

  The fiber reinforced composite material of the present invention is manufactured by a method of laminating a plurality of prepregs manufactured by such a method and then heat-curing an epoxy resin while applying heat and pressure to the obtained laminate. be able to.

  As a method for applying heat and pressure, a press molding method, an autoclave molding method, a bagging molding method, a wrapping tape method, an internal pressure molding method, and the like are used. In particular, a wrapping tape method and an internal pressure molding method are preferably used for molding sports equipment.

  The wrapping tape method is a method in which a prepreg is wound around a mandrel or the like and a tubular body made of a fiber reinforced composite material is formed, and is a suitable method for producing a rod-like body such as a golf shaft or a fishing rod. . More specifically, after winding the prepreg on a mandrel, winding a wrapping tape made of a thermoplastic resin film on the outside of the prepreg for fixing and applying pressure, and heat curing the epoxy resin in an oven, In this method, the core is removed to obtain a tubular body.

  In addition, the internal pressure molding method is to set a preform in which a prepreg is wound on an internal pressure applying body such as a tube made of a thermoplastic resin in a mold, and then apply high pressure gas to the internal pressure applying body to apply pressure. At the same time, the mold is heated to form a tubular body. This internal pressure molding method is particularly preferably used when molding a complicated shape such as a golf shaft, a bat, and a racket such as tennis or badminton.

  The carbon fiber reinforced composite material of the present invention can be manufactured by, for example, a method of laminating the above-described prepreg of the present invention in a predetermined form and pressurizing and heating to cure the epoxy resin.

  The fiber-reinforced composite material of the present invention can also be produced by a method not using a prepreg, using the above-described epoxy resin composition.

  As such a method, for example, a method of directly impregnating the epoxy resin composition of the present invention into a reinforcing fiber and then heat-curing, that is, a hand layup method, a filament winding method, a pultrusion method, a resin film -Infusion method, resin injection molding method, resin transfer molding method, etc. are used.

  In the fiber reinforced composite material of the present invention, the sphericity of the thermoplastic resin particles [D] observed in the cross section is preferably in the range of 85 to 100, and more preferably in the range of 96 to 100. By maintaining the sphericity of the thermoplastic resin particles [D], a stable interlayer thickness can be obtained regardless of the molding conditions, and the mechanical properties including mode I interlayer toughness and mode II interlayer toughness can be stabilized. It will be expressed. Such sphericity can be measured, for example, by the following procedure. The fiber reinforced composite material is cut from a direction orthogonal to the carbon fiber, and the cross section is polished, and then magnified 200 times or more with an optical microscope and photographed. The short diameter and long diameter of [D] particles are measured from this photograph, and are calculated from the average of arbitrary 30 particles according to the following numerical conversion formula.

  Hereinafter, the prepreg and the fiber-reinforced composite material of the present invention will be described more specifically with reference to examples. The production methods and evaluation methods of the resin raw materials, prepregs and fiber reinforced composite materials used in the examples are shown below. The production environment and evaluation of the prepregs of the examples are performed in an atmosphere at a temperature of 25 ° C. ± 2 ° C. and a relative humidity of 50% unless otherwise specified.

<Carbon fiber (reinforced fiber)>
"Torayca (registered trademark)" T800G-24K-31E (carbon fiber with 24,000 filaments, tensile strength 5.9 GPa, tensile elastic modulus 294 GPa, tensile elongation 2.0%, manufactured by Toray Industries, Inc.).

<Epoxy resin [A]>
"Sumiepoxy (registered trademark)" ELM434 (tetraglycidyldiaminodiphenylmethane, manufactured by Sumitomo Chemical Co., Ltd.)
"Araldide (registered trademark)" MY0510 (triglycidyl-p-aminophenol, manufactured by Huntsman Japan K.K.)
"Araldide (registered trademark)" MY0600 (triglycidyl-m-aminophenol, manufactured by Huntsman Japan K.K.)
・ GAN (N, N-diglycidylaniline, manufactured by Nippon Kayaku Co., Ltd.)
"EPON (registered trademark)" 825 (bisphenol A type epoxy resin, manufactured by Momentary Specialty Chemicals)
"EPICLON (registered trademark)" 830 (bisphenol F type epoxy resin, manufactured by DIC Corporation).

<Thermoplastic resin [B]>
"Sumika Excel (registered trademark)" PES5003P (polyethersulfone, manufactured by Sumitomo Chemical Co., Ltd., weight average molecular weight: 47000)
"Virantage (registered trademark)" VW-10700RP (polyethersulfone, manufactured by Solvay Advanced Polymers, Inc., weight average molecular weight: 21000).

<Amino group active hydrogen equivalent of 70 (g / eq.) To 150 (g / eq.) Solid amine curing agent [C]>
"Lonzacure (registered trademark)" M-MIPA (4,4'-methylene-bis (2-isopropyl-6-methylaniline, manufactured by Lonza Japan)) amino group active hydrogen equivalent: 78
4-APTP (1-N, 4-N-bis (4-aminophenyl) phenylene-1,4-dicarboxamide, manufactured by Nippon Pure Chemicals Co., Ltd.) Amino group active hydrogen equivalent: 87 (g / eq. )
4-ABPA (4-amino-N- [4-[(4-aminobenzoyl) amino] phenyl] benzamide, manufactured by Nippon Pure Chemicals Co., Ltd.) Amino group active hydrogen equivalent: 87 (g / eq.)
9,9-bis (4-aminophenyl) fluorene (manufactured by JFE Chemical Co., Ltd.) amino group active hydrogen equivalent: 87 (g / eq.)
・ 4,4′-bis (p-aminophenoxy) biphenyl (manufactured by Tokyo Chemical Industry Co., Ltd.) amino group active hydrogen equivalent: 92
"Lonzacure (registered trademark)" M-CDEA (4,4'-methylenebis (3-chloro-2,6-diethylaniline), Lonza Japan K.K.) amino group active hydrogen equivalent: 95 (g / eq. )
9,9-bis (4-amino-3-chlorophenyl) fluorene (manufactured by Tokyo Chemical Industry Co., Ltd.) amino group active hydrogen equivalent: 104 (g / eq.).

<Curing agents other than solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) To 150 (g / eq.)>
3,3′-DAS (3,3′-diaminodiphenyl sulfone, manufactured by Mitsui Chemicals Fine Co., Ltd.) Amino group active hydrogen equivalent: 62 (g / eq.)
Seikacure S (4,4′-diaminodiphenylsulfone, manufactured by Wakayama Seika Kogyo Co., Ltd.) Amino group active hydrogen equivalent: 62 (g / eq.)
-DICY7 (dicyandiamide, Mitsubishi Chemical Corporation).

<Thermoplastic resin particles [D]>
-Particle 1 (SP-10, manufactured by Toray Industries, Inc., average particle size 10 μm, particle size distribution index 1.5, sphericity 96, glass transition temperature 55 ° C.).

-Particles 2 (particles having an average particle size of 25 μm, a particle size distribution index of 1.3, a sphericity of 96, and a glass transition temperature of 137 ° C. prepared from “Trogamide (registered trademark)” CX7233 as raw materials)
(Manufacturing method of particle 2: Reference was made to pamphlet of International Publication No. 2009/142231)
In a 1000 ml pressure-resistant glass autoclave (pressure-resistant glass industry, Hyper Glaster TEM-V1000N), 39 g of polyamide (weight average molecular weight 17,000, “Trogamide (registered trademark)” CX7323) manufactured by Degussa as an organic material, organic 283 g of N-methyl-2-pyrrolidone as a solvent, 28 g of polyvinyl alcohol as polymer B (“GOHSENOL (registered trademark)” GM-14 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), weight average molecular weight 29,000, sodium acetate content 0.23 mass% , SP value 32.8 (J / cm ³ ) ^1/2 ) was added, and nitrogen substitution of 99% by volume or more was performed, followed by heating to 180 ° C. and stirring for 2 hours until the polymer was dissolved. Thereafter, 350 g of ion-exchanged water as a poor solvent was dropped at a speed of 2.92 g / min via a liquid feed pump. When about 200 g of ion exchange water was added, the system turned white. After the entire amount of water has been added, the temperature is lowered with stirring, and the resulting suspension is filtered, washed with 700 g of ion-exchanged water, reslurried, and filtered, and vacuum-dried at 80 ° C. for 10 hours. This gave 37 g of a gray colored solid. When the obtained powder was observed with a scanning electron microscope, it was a spherical fine particle shape, and was a polyamide fine particle having an average particle size of 25 μm and a particle size distribution index of 1.3.

-Particles 3 (particles having an average particle size of 18 μm, a particle size distribution index of 1.2, a sphericity of 98, and a glass transition temperature of 137 ° C. prepared from “Trogamide (registered trademark)” CX7233 as raw materials)
(Manufacturing method of the particle 3: Reference was made to the pamphlet of International Publication No. 2009/142231)
In a 1000 ml pressure-resistant glass autoclave (pressure-resistant glass industry, HyperGlaster TEM-V1000N), 37 g of polyamide (weight average molecular weight 17,000, “Trogamide (registered trademark)” CX7323) manufactured by Degussa Co., as an organic material, organic 285 g of N-methyl-2-pyrrolidone as a solvent, 28 g of polyvinyl alcohol as polymer B (“GOHSENOL (registered trademark)” GM-14, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), weight average molecular weight 29,000, sodium acetate content 0.23 mass% , SP value 32.8 (J / cm ³ ) ^1/2 ) was added, and nitrogen substitution of 99% by volume or more was performed, followed by heating to 180 ° C. and stirring for 2 hours until the polymer was dissolved. Thereafter, 350 g of ion-exchanged water as a poor solvent was dropped at a speed of 2.92 g / min via a liquid feed pump. When about 200 g of ion exchange water was added, the system turned white. After the entire amount of water has been added, the temperature is lowered with stirring, and the resulting suspension is filtered, washed with 700 g of ion-exchanged water, reslurried, and filtered, and vacuum-dried at 80 ° C. for 10 hours. This gave 36 g of a gray colored solid. When the obtained powder was observed with a scanning electron microscope, it was a spherical fine particle shape, and was a polyamide fine particle having an average particle diameter of 18 μm and a particle diameter distribution index of 1.2.

Particle 4 (particles having an average particle diameter of 8 μm, a particle diameter distribution index of 1.1, a sphericity of 98, and a glass transition temperature of 137 ° C., produced from “Trogamide (registered trademark)” CX7233 as a raw material)
(Manufacturing method of the particles 4: Reference was made to the pamphlet of International Publication No. 2009/142231)
In a 1000 ml pressure-resistant glass autoclave (Pressure Glass Industry Co., Ltd., Hyperglaster TEM-V1000N), 35 g of polyamide (weight average molecular weight 17,000, “Trogamide (registered trademark)” CX7323) manufactured by Degussa as an organic polymer, organic 280 g of N-methyl-2-pyrrolidone as a solvent, 35 g of polyvinyl alcohol as polymer B (“GOHSENOL (registered trademark)” GM-14, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), weight average molecular weight 29,000, sodium acetate content 0.23 mass% , SP value 32.8 (J / cm ³ ) ^1/2 ) was added, and nitrogen substitution of 99% by volume or more was performed, followed by heating to 180 ° C. and stirring for 2 hours until the polymer was dissolved. Thereafter, 350 g of ion-exchanged water as a poor solvent was dropped at a speed of 2.92 g / min via a liquid feed pump. When about 200 g of ion exchange water was added, the system turned white. After the entire amount of water has been added, the temperature is lowered with stirring, and the resulting suspension is filtered, washed with 700 g of ion-exchanged water, reslurried, and filtered, and vacuum-dried at 80 ° C. for 10 hours. And 34 g of a gray colored solid were obtained. When the obtained powder was observed with a scanning electron microscope, it was a spherical fine particle shape, and was a polyamide fine particle having an average particle size of 8 μm and a particle size distribution index of 1.1.

Particle 5 (“Grillamide (registered trademark)” — made from TR90 as a raw material and having an average particle size of 10 μm, a particle size distribution index of 1.5, a sphericity of 96, and a glass transition temperature of 152 ° C.)
(Method for producing particle 5)
225 g of chloroform and 22 g of polyamide (“Grillamide (registered trademark)”-TR90, manufactured by Mzavelke) having 4,4′-diamino-3,3′-dimethyldicyclohexylmethane and 1,12-dodecanedicarboxylic acid as essential components It added in the mixed solvent of 75g, and obtained the uniform solution. Next, while stirring the solution at 450 rpm, 185 g of an aqueous solution in which 6% by mass of polyvinyl alcohol (manufactured by Kanto Chemical Co., Ltd.) was dissolved was gradually added dropwise, the solution was dispersed in particles in a dispersion medium, and the solvent was removed. Later, 21 g of a white solid was obtained. When the obtained powder was observed with a scanning electron microscope, it was a spherical fine particle shape, and was a polyamide fine particle having an average particle size of 10 μm and a particle size distribution index of 1.5.

-Particles 6 (particles having an average particle size of 19 μm, a particle size distribution index of 1.1, a sphericity of 98, and a glass transition temperature of 210 ° C., produced using “Sumika Excel (registered trademark)” 5003P as a raw material)
(Method for producing particle 6)
In a 100 ml four-necked flask, 2.5 g of polyethersulfone as polymer A (weight average molecular weight 67,000 “Sumika Excel (registered trademark)” 5003P manufactured by Sumitomo Chemical Co., Ltd.) and N-methyl- 45 g of 2-pyrrolidone, 2.5 g of polyvinyl alcohol as polymer B (“GOHSENOL (registered trademark)” GL-05 manufactured by Nippon Synthetic Chemical Industry Co., Ltd., weight average molecular weight 10,600, SP value 32.8 (J / cm ³ ) ^1/2 ) was added, heated to 80 ° C., and stirred until the polymer was dissolved. After returning the temperature of the system to room temperature, 50 g of ion-exchanged water as a poor solvent was dropped at a speed of 0.41 g / min via a liquid feed pump while stirring at 450 rpm. When about 12 g of ion-exchanged water was added, the system turned white. After the entire amount of water has been added, the mixture is stirred for 30 minutes, and the resulting suspension is filtered, washed with 100 g of ion-exchanged water, and separated by filtration, followed by vacuum drying at 80 ° C. for 10 hours to obtain a white solid. 2.0 g was obtained. When the obtained powder was observed with a scanning electron microscope, it was a polyethersulfone fine particle having a true spherical fine particle shape, an average particle diameter of 19 μm, and a particle diameter distribution index of 1.1.

<Other particles>
-Particles 7 (particles having an average particle size of 12 μm, a particle size distribution index of 2.6, a sphericity of 72, and a glass transition temperature of 137 ° C., produced from “Trogamide (registered trademark)” CX7233 as a raw material)
(Method for producing particle 7)
Polyamide (weight average molecular weight 17,000, “Trogamide (registered trademark)” CX7323 manufactured by Degussa) was freeze-ground. When the obtained powder was observed with a scanning electron microscope, it was a polyamide fine particle having an anisotropic fine particle shape, an average particle size of 12 μm, and a particle size distribution index of 2.6.

  Particle 8 (produced using “Grillamide (registered trademark)”-TR55 as a raw material, average particle diameter 13 μm, particle diameter distribution index 2.1, sphericity 96, glass transition temperature 167 ° C.)

(Method for producing particle 8)
30 g of transparent polyamide (trade name “Grillamide (registered trademark)”-TR55, manufactured by Mzavelke), 2.5 g of epoxy resin (product name “Epicoat (registered trademark)” 828, manufactured by Yuka Shell Co., Ltd.), and curing 0.8 g of an agent (trade name “Tomide (registered trademark)” # 296, manufactured by Fuji Kasei Kogyo Co., Ltd.) was added to a mixed solvent of 100 g of chloroform and 35 g of methanol to obtain a uniform solution. Next, the obtained uniform solution was atomized using a spray gun for coating, stirred well, and sprayed toward the liquid surface of 1000 g of n-hexane to precipitate a solute. The precipitated solid was separated by filtration and washed well with n-hexane, and then vacuum dried at 100 ° C. for 24 hours to obtain 28 g of a white solid. When the obtained powder was observed with a scanning electron microscope, it was a true spherical fine particle shape, and was an epoxy-modified polyamide fine particle having an average particle size of 13 μm and a particle size distribution index of 2.1.

  Particle 9 (“Orgasol (registered trademark)” 2002 D Nat 1, manufactured by Arkema Co., Ltd., average particle size 20 μm, particle size distribution index 1.3, sphericity 80, glass transition temperature 40 ° C.)

  Particle 10 (“Dymic Beads (registered trademark)” UCN-5150D, manufactured by Dainichi Seika Kogyo Co., Ltd., average particle size 15 μm, particle size distribution index 1.3, sphericity 96, glass transition temperature: −27 ° C).

<Other ingredients>
DCMU99 (3- (3,4-dichlorophenyl) -1,1-dimethylurea, curing accelerator, manufactured by Hodogaya Chemical Co., Ltd.)

(1) Preparation of epoxy resin composition A predetermined amount of an epoxy resin and a thermoplastic resin are added to a kneader, and the mixture is kneaded, heated to 160 ° C, and kneaded at 160 ° C for 1 hour to obtain a transparent viscous liquid. Obtained. After the temperature was lowered to 80 ° C. while kneading, a predetermined amount of a curing agent and thermoplastic resin particles were added and further kneaded to obtain an epoxy resin composition.

(2) Preparation of prepreg The epoxy resin composition was applied onto release paper using a knife coater to prepare a resin film. Next, two resin films are stacked on both sides of the carbon fiber on a carbon fiber “Treca (registered trademark)” T800G-24K-31E manufactured by Toray Industries, Ltd., which is arranged in one direction in a sheet shape, and heated and pressurized. The resin was impregnated with carbon fiber to obtain a unidirectional prepreg having a carbon fiber basis weight of 190 g / m ² and a matrix resin mass fraction of 35.5%. In that case, when using the epoxy resin composition which mix | blended the thermoplastic resin particle, the following two-stage impregnation methods were applied, and the prepreg which the thermoplastic resin particle highly localized in the surface layer was produced.

First, a primary prepreg containing no thermoplastic resin particles was produced. Among the raw material components described in Tables 1 and 2, an epoxy resin composition containing no thermoplastic resin particles insoluble in the epoxy resin was prepared by the procedure (1). This epoxy resin composition for primary prepreg was applied onto release paper using a knife coater to prepare a resin film for primary prepreg of 30 g / m ² having a normal basis weight of 60% by mass. Next, two primary prepreg resin films are stacked on both sides of the carbon fiber on a carbon fiber “Treka (registered trademark)” T800G-24K-31E manufactured by Toray Industries, Inc. arranged in one direction in a sheet shape. In addition, using a heat roll, the resin was impregnated into carbon fiber while heating and pressurizing at a temperature of 100 ° C. and an atmospheric pressure of 1 atm to obtain a primary prepreg.

Furthermore, in order to produce a resin film for two-stage impregnation, among the raw material components listed in Tables 1 and 2, the thermoplastic resin particles insoluble in the epoxy resin were made 2.5 times the stated amount using a kneader. An epoxy resin composition was prepared by the procedure (1) above. This two-stage impregnation epoxy resin composition was applied onto release paper using a knife coater to prepare a 20-gram / m ² two-stage impregnation resin film having a normal basis weight of 40% by mass. This was superposed on both sides of the primary prepreg and heated and pressed at a temperature of 80 ° C. and an atmospheric pressure of 1 atm using a heat roll to obtain a prepreg in which thermoplastic resin particles were highly localized on the surface layer.

(3) Mode I Interlaminar toughness _{(G IC)} in accordance with Preparation of the test composite made flat and _{G IC} measurement JIS K7086 (1993), the following (a) ~ (e) the composite material made flat for _{G IC} test by operating the Was made.
(A) The unidirectional prepreg produced in (2) was laminated in 20 ply with the fiber direction aligned. However, a fluororesin film having a width of 40 mm and a thickness of 12.5 μm was sandwiched between the laminated central planes (between the 10th and 11th plys) perpendicular to the fiber arrangement direction.
(B) The laminated prepreg is covered with a nylon film so that there is no gap, and is molded in an autoclave at a temperature of 180 ° C. for 2 hours under a pressure of 0.59 MPa at a heating rate of 1.5 ° C./min. Directional fiber reinforced composite material was molded.
(C) The unidirectional fiber reinforced composite material obtained in (b) was cut into a width of 20 mm and a length of 195 mm. The fiber direction was cut so as to be parallel to the length side of the sample.
(D) According to JIS K7086 (1993), a pin load block (length: 25 mm, made of aluminum) was bonded to the end of the test piece (the side where the film was sandwiched).
(E) A white paint was applied to both sides of the test piece in order to make it easier to observe the crack growth.

Using the produced composite material flat plate, a test was performed using an Instron universal testing machine (Instron) according to JIS K7086 (1993) Annex 1. The crosshead speed was 0.5 mm / min until the crack growth reached 20 mm, and 1 mm / min after reaching 20 mm. According to JIS K7086 (1993), the mode I interlaminar fracture toughness value (G _IC ) at the initial stage of crack propagation and the mode I interlaminar fracture toughness of the crack propagation process from the load, displacement, and crack length. The value was calculated. Crack growth early _{G IC} and crack propagation than 10mm measured value of 5 or more in 60mm from an average of six or more points of measurements were compared as _{G IC.}

(4) Fabrication of plate made of composite material for mode II interlaminar toughness (G _IIC ) test and G _IIC measurement According to JIS K7086 (1993), a plate made of composite material for G _IIC test by the following operations (a) to (d) Was made.
(A) The unidirectional prepreg produced in (2) was laminated in 20 ply with the fiber direction aligned. However, a fluororesin film having a width of 40 mm and a thickness of 12.5 μm was sandwiched between the laminated central planes (between the 10th and 11th plys) perpendicular to the fiber arrangement direction.
(B) The laminated prepreg is covered with a nylon film so that there is no gap, and is molded in an autoclave at a temperature of 180 ° C. for 2 hours under a pressure of 0.59 MPa at a heating rate of 1.5 ° C./min. Directional fiber reinforced composite material was molded.
(C) The unidirectional fiber reinforced composite material obtained in (b) was cut into a width of 20 mm and a length of 195 mm. The fiber direction was cut so as to be parallel to the length side of the sample.
(D) A white paint was applied to both sides of the test piece to facilitate the observation of crack growth.

  Using the produced composite material flat plate, a test was performed using an Instron universal testing machine (Instron) according to JIS K7086 (1993) Annex 2. The crosshead speed was 0.5 mm / min. According to JIS K7086 (1993), the mode II interlaminar fracture toughness value at the initial stage of crack growth was calculated from the load, displacement, and initial crack length.

(5) Measurement of tackiness of prepreg The prepreg was cut into a width of 100 mm and a length of 200 mm, and attached to a flat aluminum plate with a double-sided tape. When this prepreg was allowed to stand for 24 hours in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50%, 18 mm × 18 mm glass was pressed against the surface of the prepreg with a load of 0.4 kg for 5 seconds and then pulled up at a speed of 30 mm / min. The peel force (kgf) was measured and used as an index of tackiness of the prepreg.

Example 1
After kneading 70 parts by mass of “Araldide (registered trademark)” MY0510 (epoxy resin [A]) and 30 parts by mass of “EPICLON (registered trademark)” 830 (epoxy resin [A]) in a kneader, 56 parts by mass Part of “Virantage (registered trademark)” VW-10700RP (thermoplastic resin [B]) was melt-kneaded at 160 ° C., and then the epoxy resin composition was cooled to 80 ° C. and 68 parts by mass of “Lonacure (registered trademark)”. "M-MIPA (solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) To 150 (g / eq.)", 33 parts by mass of particles 3 (thermoplastic resin particles [D ]) Was kneaded to prepare an epoxy resin composition. Table 1 shows the composition and ratio (in Table 1, the numbers represent parts by mass). Using the obtained epoxy resin composition, a prepreg was produced by the procedure (2). Using the obtained prepreg, (3) Mode I Interlaminar toughness _{(G IC)} Preparation and _{G IC} measurement of the test composite made flat, making the (4) Mode II interlayer toughness _{(G IIC)} test composite made flat And _GIIC measurement, and (5) prepreg tack measurement. The results are shown in Table 1.

(Examples 2-14, Comparative Examples 1-8)
Epoxy resin, thermoplastic resin, curing agent, thermoplastic resin particles and other components, epoxy resin in the same manner as in Example 1 except that the blending amounts of other particles were changed as shown in Tables 1 to 3 A composition and a prepreg were prepared. Using the obtained prepreg, (3) Mode I Interlaminar toughness _{(G IC)} Preparation and _{G IC} measurement of the test composite made flat, making the (4) Mode II interlayer toughness _{(G IIC)} test composite made flat And _GIIC measurement, and (5) prepreg tack measurement. The results are shown in Table 1 for Examples 2-7, Table 2 for Examples 8-14, and Table 3 for Comparative Examples 1-8.

(Comparative Example 9)
An epoxy resin composition and a prepreg were produced in the same manner as in Example 1 except that the epoxy resin, the thermoplastic resin, and the curing agent were changed as shown in Table 3. Using the obtained prepreg, (3) Mode I Interlaminar toughness _{(G IC)} Preparation and _{G IC} measurement of the test composite made flat, making the (4) Mode II interlayer toughness _{(G IIC)} test composite made flat And _GIIC measurement, and (5) prepreg tack measurement. The results are shown in Table 3.

From the comparison between Examples 1 to 14 and Comparative Examples 1 to 9, it can be seen that the fiber-reinforced composite material according to the present invention is excellent in interlayer toughness G _IC and G _IIC , and has low tackiness and excellent moldability.

From the comparison between Examples 1 to 14 and Comparative Examples 1 and 2, the epoxy resin [A], the thermoplastic resin [B], and the amino group active hydrogen equivalent is 70 (g / eq.) Or more and 150 (g / eq.). The following solid amine curing agent [C] is blended, but when the particle size distribution index of the thermoplastic resin particles does not satisfy (d1), the interlayer thickness of the fiber reinforced composite material becomes uneven, and the fiber reinforced composite material It can be seen that the interlaminar toughness G _IIC decreases, the tackiness increases, and the moldability is inferior.

From the comparison between Examples 1 to 14 and Comparative Example 3, the epoxy resin [A], the thermoplastic resin [B], and the amino group active hydrogen equivalent are 70 (g / eq.) Or more and 150 (g / eq.) Or less. When the solid amine curing agent [C] is blended but the sphericity of the thermoplastic resin particles does not satisfy (d2), the interlayer thickness of the fiber reinforced composite material becomes narrow, and the interlayer toughness of the fiber reinforced composite material G _IIC decreases.

From the comparison between Examples 1 to 14 and Comparative Example 4, the epoxy resin [A], the thermoplastic resin [B], and the amino group active hydrogen equivalent are 70 (g / eq.) Or more and 150 (g / eq.) Or less. Although solid amine curing agent [C] is blended, if the glass transition temperature of the thermoplastic resin particles does not satisfy (d3), it is understood that the interlayer toughness G _IC of a fiber-reinforced composite material is reduced.

From the comparison between Examples 1 to 14 and Comparative Example 5, the epoxy resin [A], the thermoplastic resin [B], and the amino group active hydrogen equivalent is 70 (g / eq.) Or more and 150 (g / eq.) Or less. When the solid amine curing agent [C] is blended, but the particle size distribution index and sphericity of the thermoplastic resin particles do not satisfy (d1) and (d2), the interlayer thickness of the fiber reinforced composite material is not uniform. Thus, it can be seen that the interlaminar toughness G _IC of the fiber reinforced composite material is lowered.

From a comparison between Examples 1 to 14 and Comparative Example 6, the epoxy resin [A] and the solid amine curing agent [C] having an amino group active hydrogen equivalent weight of 70 (g / eq.) Or more and 150 (g / eq.) Or less. When the thermoplastic resin particles [D] are blended, but when the thermoplastic resin [B] is not blended, the interlaminar toughness G _IC of the fiber-reinforced composite material is lowered, and the tack property is increased and the moldability is increased. It turns out that it is inferior.

From the comparison between Examples 1 to 14 and Comparative Examples 7 and 8, the epoxy resin [A], the thermoplastic resin [B], and the thermoplastic resin particles [D] are blended, but the amino group active hydrogen equivalent is 70. When the solid amine curing agent [C] of (g / eq.) Or more and 150 (g / eq.) Or less is not blended, the interlaminar toughness G _IC of the fiber reinforced composite material is lowered, and the tack property is also increased. It turns out that the nature is inferior.

From the comparison between Examples 1 to 14 and Comparative Example 9, the epoxy resin [A], the thermoplastic resin [B], and the amino group active hydrogen equivalent is 70 (g / eq.) Or more and 150 (g / eq.) Or less. When the solid amine curing agent [C] is blended but the thermoplastic resin particles [D] are not blended, the fiber-reinforced composite material cannot have an interlayer, and the fiber-reinforced composite material has an interlayer toughness G _IC and G _IIC. As a result, the tackiness increases and the moldability decreases.

  According to the present invention, an epoxy resin composition having mode I interlayer toughness, mode II interlayer toughness, and moldability is obtained. Furthermore, since the fiber reinforced composite material obtained by such an epoxy resin composition is excellent in mechanical strength such as compressive strength and interlayer toughness, it is particularly suitable for structural materials. For example, for aerospace applications, primary aircraft structural materials such as main wings, tail wings and floor beams, secondary structural materials such as flaps, ailerons, cowls, fairings and interior materials, rocket motor cases and satellite structural materials Preferably used. In general industrial applications, structural materials for moving bodies such as automobiles, ships, and railway vehicles, drive shafts, leaf springs, windmill blades, various turbines, pressure vessels, flywheels, paper rollers, roofing materials, cables, reinforcement bars And suitable for civil engineering and building material applications such as repair and reinforcement materials. Furthermore, in sports applications, it is suitably used for golf shafts, fishing rods, tennis, badminton and squash rackets, hockey sticks, and ski pole applications.

Claims (12)

A prepreg comprising at least the following components [A], [B], [C], [D] and reinforcing fibers.
[A] Epoxy resin [B] Thermoplastic resin [C] Solid amine curing agent having an amino group active hydrogen equivalent weight of 70 (g / eq.) Or more and 150 (g / eq.) Or less [D] Next (d1) to (D3) Thermoplastic resin particles insoluble in epoxy resin that satisfy the condition (d3) (d1) Particle size distribution index is 1.0 to 1.8 (d2) Particles having a sphericity of 85 or more (d3) particles Has a glass transition temperature of 40 to 300 ° C. The prepreg according to claim 1, wherein the solid amine curing agent [C] has a melting point of 80 ° C. or higher and 330 ° C. or lower. The prepreg according to claim 1 or 2, wherein the epoxy resin [A] contains an amine type epoxy resin. The prepreg according to claim 3, wherein the epoxy resin [A] contains 20 to 100 parts by mass of an amine-type epoxy resin. The prepreg in any one of Claims 1-4 whose glass transition temperature of thermoplastic resin [B] is 150 degreeC or more. The prepreg according to any one of claims 1 to 5, wherein the thermoplastic resin [B] has a weight average molecular weight in the range of 4000 to 50000 g / mol. The prepreg according to any one of claims 1 to 6, wherein the thermoplastic resin particles [D] have an average particle diameter of 5 to 50 µm. The prepreg in any one of Claims 1-7 whose thermoplastic resin particle [D] is a polyamide particle containing the chemical structure of General formula (1).

(Wherein R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a halogen element, and may be the same or different. R ₃ is a methylene having 1 to 20 carbon atoms) Represents a group or a phenylene group.) The prepreg according to any one of claims 1 to 8, wherein 90% or more of the thermoplastic resin particles [D] are present within a depth range of 20% of the thickness of the prepreg from the prepreg surface. The prepreg according to any one of claims 1 to 9, wherein the reinforcing fibers are carbon fibers. A fiber-reinforced composite material obtained by curing the prepreg according to claim 1. The fiber-reinforced composite material according to claim 11, wherein the sphericity of the particles [D] observed by an optical microscope in a cross-section of the fiber-reinforced composite material is in the range of 85 to 100.