The present invention provides an epoxy resin composition that serves to produce a cured epoxy resin that simultaneously realizes a high heat resistance, a high elastic modulus, and a low color and to produce a molded article having a good appearance without suffering the formation of white spots on the surface thereof when used as matrix resin in a fiber reinforced composite material. The epoxy resin composition includes an epoxy resin as component [A], an aromatic urea [B1] and/or an imidazole compound [B2] as component [B], and a borate ester compound as component [C], containing dicyandiamide in the amount of 0.5 part by mass or less relative to the total quantity of epoxy resins which accounts for 100 parts by mass, wherein the epoxy resin composition meets certain sets of further requirements with respect to its composition.

Disclosed is a fiber-reinforced resin composite body (1) including: a thermosetting resin (2); a plurality of reinforcing fiber layers (4) stacked in the thermosetting resin (2); and a thermoplastic resin (5) dispersed in a form of particles in the thermosetting resin (2) between the plurality of reinforcing fiber layers (4).

The invention provides a prepreg having high storage stability and serving suitably for producing components, such as structural members and interior members of aircraft and structural members of aircraft engines, that require high heat resistance under high temperature and high humidity conditions, where the prepreg exhibits good physical properties and good combustion properties. The prepreg is produced by impregnating component [A] with an epoxy resin composition containing components [B] to [D], wherein component [A] in the prepreg accounts for 50 mass % or more, where [A] is a carbon fiber, [B] is an epoxy resin, [C] is a fluorene type curing agent having a maximum particle size of 100 μm or less, and [D] is a thermoplastic resin.

A curative resin containing at least 50 wt % of an epoxy phenolic resin comprising a mixture of a carboxylic hydrazide and a hydroxy substituted urone.

A thermoplastic polymer-based composite material and a preparation method thereof are provided. The thermoplastic polymer-based composite material is obtained by impregnating a reinforcing material with a mixture or an oligomer of an epoxy resin, a bisphenol A/F, and a catalyst and then performing an in-situ polymerization. The thermoplastic polymer-based composite material is less expensive to produce, has an optimal impregnation effect, excellent secondary processing performance, high heat resistance, desirable mechanical properties and excellent overall performance.

The present invention addresses the problem of providing: a towpreg that has superior bobbin unspoolability and process pass-through properties, and is capable of yielding a fiber-reinforced composite having extremely high 0° tensile strength utilization; and a pressure vessel using such a towpreg. The means for solving this problem is a towpreg obtained by impregnating a reinforcing fiber tow with an epoxy resin composition containing [A]-[D], wherein: the epoxy resin composition contains 10-90 parts by mass of [A] and 10-50 parts by mass of [B] per 100 parts by mass of the epoxy resin component; the epoxy resin composition has a 25° C. viscosity (η.sub.25) of 1-40 Pa.Math.s and a 40° C. viscosity (η.sub.40) of 0.2-5 Pa.Math.s; and the cured epoxy resin composition has a glass transition temperature (Tg) of 95° C. or higher. [A] A bisphenol epoxy resin [B] Unsubstituted or substituted N,N-diglycidyl aniline [C] Dicyandiamide [D] A cure accelerator

A heat-curable epoxy resin composition is a mixture in which an epoxy compound represented by formula (al), a polyisocyanate, a bisphenol type liquid epoxy resin and an epoxy resin curing agent are blended. An amount of the epoxy compound, per 100 parts by mass of all the epoxy resin blended in the heat-curable epoxy resin composition, is 5 parts by mass or more.

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Provided is a sheet molding compound which can inhibit the formation of burrs during press molding, enables a matrix resin to exhibit excellent fluidity and excellent quick curing properties during press molding, and makes it possible to obtain a fiber-reinforced composite excellent in mold release properties, mechanical characteristics, and heat resistance. The sheet molding compound of the present invention contains an epoxy resin composition and reinforcing fiber, in which a gel time of the epoxy resin composition is 30 to 140 seconds at 140° C., a temperature at the start of curing reaction of the epoxy resin composition is 70° C. to 115° C., and when b1 represents a viscosity of the epoxy resin composition measured at 30° C. 7 days after the preparation of the composition, and b2 represents a viscosity of the epoxy resin composition measured at 30° C. 14 days after the preparation of the composition, b1 and b2 satisfy b2/b1≤5.

A one-component thermosetting epoxy resin composition, including a) at least one epoxy resin A having on average more than one epoxide group per molecule; b) at least one latent hardener for epoxy resins; c) at least one physical or chemical blowing agent BA; d) 3-15 wt.-% of at least one carboxyl group containing acrylonitrile/butadiene rubber ABR1 with a Mooney Viscosity of 15-30 MU (Mooney units), based on the total amount of epoxy resin A; and e) 3-15 wt.-% of at least one carboxyl group containing acrylonitrile/butadiene rubber ABR2 with a Mooney Viscosity of 35-50 MU (Mooney units), based on the total amount of epoxy resin A. The ratio of ABR1 to ABR2 is from 0.5-2.0. The epoxy resin adhesive is notable for the improved storage stability.

A resin supply material used for press molding or vacuum-pressure molding of a fiber-reinforced resin, the resin supply material including a continuous porous material and a thermosetting resin, wherein an average pore cross-sectional area ratio P expressed by formula (I) is 1.1 or more:
P=AII/AI  (I) AI: average pore cross-sectional area in region I AII: average pore cross-sectional area in region II Region I: region occupying 10% of total volume of continuous porous material from surface layer on both surfaces thereof Region II: whole region of continuous porous material.