Abstract: Provided are an epoxy resin composition for manufacturing a fiber reinforced composite material having excellent curability allowing for curing in a short time, and excellent storage stability and heat resistance, and a prepreg and a fiber reinforced composite material using the same. The epoxy resin composition includes at least an epoxy resin [A], a curing agent [B] having an exothermic onset temperature higher than the exothermic onset temperature of a component [C], as measured by a differential scanning calorimeter, and the component [C] contains a compound represented by a particular formula (a), and a prepreg and a fiber reinforced composite material using the same.

Abstract: Provided is an epoxy resin composition for giving a carbon fiber-reinforced composite material that simultaneously achieves tensile strength and compressive strength. An epoxy resin composition containing at least the following constituent elements [A]-[D] wherein the epoxy resin composition contains 5-50 mass % of constituent element [A] and 20-95 mass % of constituent element [B] relative to 100 mass % of total epoxy resin weight. [A]: at least one epoxy resin selected from 1,2-bis(glycidyloxy)benzene, 1,3-bis(glycidyloxy)benzene, 1,4-bis(glycidyloxy)benzene, derivatives of these, and epoxy resins having a structure represented by general formula [1] (in general formula [1], at least one of R1-R5 and at least one of R6-R10 is a glycidyl ether group, and the other R1-R10 represent any of a hydrogen atom, halogen atom, or aliphatic hydrocarbon group having four or fewer carbon atoms.

Abstract: Provided are an epoxy resin composition for manufacturing a fiber reinforced composite material having excellent curability allowing for curing in a short time, and excellent storage stability and heat resistance, and a prepreg and a fiber reinforced composite material using the same. The epoxy resin composition includes at least an epoxy resin [A], a curing agent [B] having an exothermic onset temperature higher than the exothermic onset temperature of a component [C], as measured by a differential scanning calorimeter, and the compound [C] represented by formula (a), in which the compounding ratio for the components satisfies equations (1) and (2), and a prepreg and a fiber reinforced composite material using the same. Equation (1): 0.5 (moles of active hydrogen included in component [B]+moles of active hydrogen included in component [C])/moles of epoxy groups in component [A]?1.5; Equation (2) 0.02?moles of component [C]/moles of component [B]?5.0.

Abstract: A prepreg includes a fiber layer containing unidirectionally arranged carbon fibers impregnated with a thermosetting resin and a resin layer existing on at least one side of the fiber layer and containing a thermosetting resin and a thermoplastic resin insoluble in the thermosetting resin. The prepreg contains carbon fibers having an areal weight of fibers of 120 to 300 g/m2 and has a weight fraction of resin of 25 to 50 mass %. An extreme value frequency of a surface geometry along a straight line perpendicular to the fibers of the prepreg is 30 points/mm or less when the prepreg has been exposed, for 24 hours, to a temperature at which a coefficient of interlayer friction is the lowest. Using sheets of the prepreg which are laid up, the coefficient of interlayer friction of the prepreg is measured at 10° C. intervals in a temperature range of 40 to 80° C. under the conditions: a pulling speed of 0.2 mm/min, a perpendicular stress of 0.1 bar, and a pulling displacement of 1 mm.

Abstract: Provided are: an epoxy resin composition that gives a carbon fiber-reinforced composite material having excellent moldability, heat resistance, and mechanical properties such as tensile strength and compressive strength; and a prepreg. An epoxy resin composition containing at least the following constituent elements [A]-[D]. The epoxy resin composition contains 5-50 parts by mass of constituent element [A] and 20-95 parts by mass of constituent element [B], as well as 1-25 parts by mass of constituent element [C], relative to 100 parts by mass of the total amount of epoxy resin. Constituent element [A] is an epoxy resin having primarily two epoxy groups and one or more condensed polycyclic aromatic hydrocarbon skeletons within a repeating unit of a specific structure; [B] is a glycidylamine epoxy resin having three or more glycidyl groups in the molecule; [C] is a sulfone or imide thermoplastic resin; and [D] is an epoxy resin curing agent.

Abstract: An embodiment relates to a resin composition containing a tetraglycidyl amine; a bisphenol epoxy; a dicyandiamide; and an aromatic urea; wherein the tetraglycidyl amine has a EEW of 110 g/eq to 140 g/eq and is an amount of 30 to 60 PHR per 100 PHR of total epoxy resin in the resin composition; wherein the resin composition has a Tg of at least 160° C. when cured at 143° C. for 3 min and also maintains a Tg of greater than 160° C. when cured at 177 C for 1 min or longer.

Abstract: Provided is an epoxy resin composition including the following component [A]: a tri- or more functional binaphthalene epoxy resin represented by the following general formula (A-1) and component [B]: an aromatic amine compound, in which the glass transition temperature of a cured product, which is obtained by curing the epoxy resin composition at 180° C. for 2 hours, after immersing in boiling water at 1 atm for 48 hours is 180° C. or more. An epoxy resin composition and a prepreg which can form a fiber-reinforced composite material excellent in heat resistance under high humidity are provided.

Abstract: Provided is an epoxy resin composition for giving a carbon fiber-reinforced composite material that simultaneously achieves tensile strength and compressive strength. An epoxy resin composition containing at least the following constituent elements [A]-[D] wherein the epoxy resin composition contains 5-50 mass % of constituent element [A] and 20-95 mass % of constituent element [B] relative to 100 mass % of total epoxy resin weight. [A]: at least one epoxy resin selected from 1,2-bis(glycidyloxy)benzene, 1,3-bis(glycidyloxy)benzene, 1,4-bis(glycidyloxy)benzene, derivatives of these, and epoxy resins having a structure represented by general formula [1] (in general formula [1], at least one of R1-R5 and at least one of R6-R10 is a glycidyl ether group, and the other R1-R10 represent any of a hydrogen atom, halogen atom, or aliphatic hydrocarbon group having four or fewer carbon atoms.

Abstract: A epoxy resin composition includes a given epoxy resin [A], an aromatic amine compound [B], an organic acid hydrazide compound [C] having a structural formula represented by general formula (I) or (II) (X is a structure selected from among monocyclic and polycyclic aromatic ring structures, polycyclic aromatic ring structures, and aromatic heterocyclic structures and optionally has, as a substituent, any of C4 or lower alkyl groups, a hydroxy group, and an amino group), and a thermoplastic resin [D], wherein the amount of the constituent element [C] is 1-25 parts by mass per 100 parts by mass of the constituent element [A], the epoxy resin composition, after having been held at 80° C. for 2 hours, having a viscosity which is up to 2.0 times the initial viscosity at 80° C.

Abstract: Provided are a fiber-reinforced composite material excellent in heat resistance and strength properties, an epoxy resin composition to obtain the fiber-reinforced composite material, and a prepreg obtained by using the epoxy resin composition. Further provided are a fiber-reinforced composite material having less volatile matters during the curing time, and having excellent heat resistance and strength properties, an epoxy resin composition to obtain the fiber-reinforced composite material, and a prepreg obtained by using the epoxy resin composition. Provided are: an epoxy resin composition for a fiber-reinforced composite material, comprising an amine type epoxy resin [A], an aromatic amine curing agent [B], and a block copolymer [C] having a reactive group capable of reacting with an epoxy resin; a prepreg obtained by impregnating a reinforced fiber with the epoxy resin composition; and a fiber-reinforced composite material obtained by curing the prepreg.

Abstract: The embodiments herein relate to a benzoxazine resin composition, a prepreg, and a carbon fiber-reinforced composite material. More specifically, the embodiments herein relate to a benzoxazine resin composition that provides a carbon fiber-reinforced composite material that is suitable for use as a manufacture material due to its superior mechanical strength in extreme use environments, such as high temperature and high moisture, as well as a prepreg, and a carbon fiber-reinforced composite material. An embodiment comprises a benzoxazine resin composition having a multifunctional benzoxazine resin; a multifunctional epoxy resin that is a liquid at 40° C. and has three or more glycidyl groups; a sulfonate ester; and optionally at least one thermoplastic resin. The resin may include an interpenetrating network structure after curing.

Abstract: The present invention relates to a sheet-form prepreg which comprises a plurality of carbon fibers and a matrix resin with which the plurality of carbon fibers are impregnated. This matrix resin contains a thermosetting resin, a curing agent, conductive particles of 1 ?m or smaller in diameter, conductive particles of 5 ?m or larger in diameter and thermoplastic resin particles, and the conductive particles of 1 ?m or smaller in diameter, the conductive particles of 5 ?m or larger in diameter and the thermoplastic resin particles are each disproportionately distributed in a specific part of the prepreg. By the present invention, a prepreg from which a carbon fiber-reinforced composite material having both excellent impact resistance and good conductivity in the lamination direction can be produced is provided.

Abstract: Disclosed is a carbon-fiber-reinforced composite material that is suitable for use as a construction material and exhibits high mechanical strength in harsh usage environments such as low-temperature environments and high-temperature moisture-absorbing environments. Also disclosed are an epoxy resin composition for producing the aforementioned carbon-fiber-rein-forced composite material and a prepreg obtained through the use of said epoxy resin composition. Said epoxy resin composition comprises at least the following constituents, by mass with respect to the total mass of the composition: (A) between 20% and 80% of an epoxy resin having the structure represented by formula (1); and (B) between 10% and 50% of an epoxy resin that has at least two ring structures with four or more members each and also has one amine glycidyl or ether glycidyl directly connected to a ring structure.

Abstract: An embodiment relates to a resin composition containing a tetraglycidyl amine; a bisphenol epoxy; a dicyandiamide; and an aromatic urea; wherein the tetraglycidyl amine has a EEW of 110 g/eq to 140 g/eq and is an amount of 30 to 60 PHR per 100 PHR of total epoxy resin in the resin composition; wherein the resin composition has a Tg of at least 160° C. when cured at 143° C. for 3 min and also maintains a Tg of greater than 160° C. when cured at 177C for 1 min or longer.

Abstract: The embodiments herein relate to a benzoxazine resin composition, a prepreg, and a carbon fiber-reinforced composite material. More specifically, the embodiments herein relate to a benzoxazine resin composition that provides a carbon fiber-reinforced composite material that is suitable for use as a manufacture material due to its superior mechanical strength in extreme use environments, such as high temperature and high moisture, as well as a prepreg, and a carbon fiber-reinforced composite material. An embodiment comprises a benzoxazine resin composition having a multifunctional benzoxazine resin; a multifunctional epoxy resin that is a liquid at 40° C. and has three or more glycidyl groups; a sulfonate ester; and optionally at least one thermoplastic resin. The resin may include an interpenetrating network structure after curing.

Abstract: An epoxy compound of high-purity N,N,N?,N?-tetraglycidyl-3,4?-diaminodiphenyl ether is produced by: an addition reaction step of reacting 3,4?-diaminodiphenyl ether with epichlorohydrin in a polar protic solvent at 65 to 100° C. for 12 hours or longer to form N,N,N?,N?-tetrakis(3-chloro-2-hydroxypropyl)-3,4?-diaminodiphenyl ether; and a cyclization reaction step of reacting the N,N,N?,N?-tetrakis(3-chloro-2-hydroxypropyl)-3,4?-diaminodiphenyl ether with an alkali compound for dehydrochlorination.

Abstract: The present invention relates to a sheet-form prepreg which comprises a plurality of carbon fibers and a matrix resin with which the plurality of carbon fibers are impregnated. This matrix resin contains a thermosetting resin, a curing agent, conductive particles of 1 ?m or smaller in diameter, conductive particles of 5 ?m or larger in diameter and thermoplastic resin particles, and the conductive particles of 1 ?m or smaller in diameter, the conductive particles of 5 ?m or larger in diameter and the thermoplastic resin particles are each disproportionately distributed in a specific part of the prepreg. By the present invention, a prepreg from which a carbon fiber-reinforced composite material having both excellent impact resistance and good conductivity in the lamination direction can be produced is provided.

Abstract: Provided are: a fiber-reinforced composite material which has mode I interlaminar fracture toughness, mode II interlaminar fracture toughness and compressive strength under heat and humidity conditions at the same time; an epoxy resin composition for obtaining the fiber-reinforced composite material; and a prepreg which is obtained using the epoxy resin composition. An epoxy resin composition for fiber-reinforced composite materials, which contains at least the following constituent elements (A), (B), (C) and (D). (A) An epoxy resin (B) Resin particles that satisfy the following conditions (b1)-(b3) and are insoluble in an epoxy resin (b1) The particle size distribution index is 1.0-1.8. (b2) The particle sphericity is 90 or more. (b3) The glass transition temperature of the particles is 80-180° C. (C) At least one elastomer component that is selected from among block copolymers containing a block having a glass transition temperature of 20° C.

Abstract: Provided are a fiber-reinforced composite material excellent in heat resistance and strength properties, an epoxy resin composition to obtain the fiber-reinforced composite material, and a prepreg obtained by using the epoxy resin composition. Further provided are a fiber-reinforced composite material having less volatile matters during the curing time, and having excellent heat resistance and strength properties, an epoxy resin composition to obtain the fiber-reinforced composite material, and a prepreg obtained by using the epoxy resin composition. Provided are: an epoxy resin composition for a fiber-reinforced composite material, comprising an amine type epoxy resin [A], an aromatic amine curing agent [B], and a block copolymer [C] having a reactive group capable of reacting with an epoxy resin; a prepreg obtained by impregnating a reinforced fiber with the epoxy resin composition; and a fiber-reinforced composite material obtained by curing the prepreg.

Abstract: An epoxy compound of high-purity N,N,N?,N?-tetraglycidyl-3,4?-diaminodiphenyl ether is produced by: an addition reaction step of reacting 3,4?-diaminodiphenyl ether with epichloro-hydrin in a polar protic solvent at 65 to 100° C. for 12 hours or longer to form N,N,N?,N?-tetrakis(3-chloro-2-hydroxypropyl)-3,4?-diaminodiphenyl ether; and a cyclization reaction step of reacting the N,N,N?,N?-tetrakis(3-chloro-2-hydroxypropyl)-3,4?-diaminodiphenyl ether with an alkali compound for dehydrochlorination.