Abstract: A resin composition that has good heat resistance and handleability and that can produce a prepreg which has a good balance between tackyness and drapability and which causes little resin flow during prepreg molding, a prepreg that is manufactured using the resin composition, and a fiber-reinforced composite are provided. A resin composition that contains a maleimide compound, diallyl bisphenol A, and a diallyl isophthalate polymer, a prepreg in which reinforcing fibers are impregnated with the resin composition, and a fiber-reinforced composite material that is obtained by molding the prepreg are provided.

Abstract: The present invention relates to a method for producing a prepreg which contains reinforcing fibers and a matrix resin composition with the weight per square meter of the reinforcing fibers being 250-2,000 g/m2. The production method comprises the following steps (1)-(3): (1) a matrix resin composition blending step for obtaining a matrix resin composition by mixing an epoxy resin, a radically polymerizable unsaturated compound, an epoxy resin curing agent and a polymerization initiator that generates radicals, in said step the content of the radically polymerizable unsaturated compound relative to 100% by mass of the total of the epoxy resin and the radically polymerizable unsaturated compound being 10-25% by mass; (2) a matrix resin composition impregnating step; and (3) a surface viscosity increasing step.

Abstract: Provided is a method for producing a good epoxy resin composition for obtaining fiber-reinforced plastics. A production method for obtaining a fiber-reinforced composite material by impregnating a fiber assembly with an epoxy resin composition and then curing the epoxy resin composition, wherein the epoxy resin composition contains a component [A], a component [B] and a component [C] respectively satisfying the conditions described below. When the blending amount of the component [B] is set to b parts by mass and the blending amount of the component [C] is set to c parts by mass relative to 100 parts by mass of the component [A] contained in the epoxy resin composition, formula (2) is satisfied within the range of formula (1), formula (4) is satisfied within the range of formula (3), and formula (6) is satisfied within the range of formula (5).

Abstract: The present invention relates to an epoxy resin composition which comprises a phosphorus-containing modified epoxy resin (A) consisting of a compound (a) represented by Formula (a); a novolak epoxy resin (B); a hardener (C) for epoxy resins; and a metal hydroxide (D), wherein the content in mass % of the phosphorus-containing modified epoxy resin (A), CA, and the content in mass % of the metal hydroxide (D), CD, relative to the total amount of the epoxy resin composition, satisfy the following Formulas (1), (2), and (3): (1) 2.5CA+CD?45; (2) 6?CA?40; and (3) 3?CD?30. This epoxy resin composition can give a composite material which has excellent flame retardancy even when neither a halogenated flame retardant, nor red phosphorus, nor a phosphoric acid ester is contained therein. According to the invention, it is also possible to provide a prepreg and a fiber-reinforced composite material obtained using the prepreg.

Abstract: A reinforced-fiber sheet impregnated with a matrix resin, a protective film having an irregular surface is applied to at least one surface of the reinforced-fiber sheet impregnated with the matrix resin such that the irregular surface faces the reinforced-fiber sheet. The thus-formed reinforced-fiber sheet covered with a protective film is kept at a temperature of 50-130° C. for four hours or more such that the viscosity of the impregnated resin is 100-10000 poise.

Abstract: The present invention relates to an epoxy resin composition which comprises a phosphorus-containing modified epoxy resin (A) consisting of a compound (a) represented by Formula (a); a novolak epoxy resin (B); a hardener (C) for epoxy resins; and a metal hydroxide (D), wherein the content in mass % of the phosphorus-containing modified epoxy resin (A), CA, and the content in mass % of the metal hydroxide (D), CD, relative to the total amount of the epoxy resin composition, satisfy the following Formulas (1), (2), and (3): (1) 2.5CA+CD?5; (2) 6?CA?40; and (3) 3?CD?30. This epoxy resin composition can give a composite material which has excellent flame retardancy even when neither a halogenated flame retardant, nor red phosphorus, nor a phosphoric acid ester is contained therein. According to the invention, it is also possible to provide a prepreg and a fiber-reinforced composite material obtained using the prepreg.

Abstract: The present invention relates to a method for producing a prepreg which contains reinforcing fibers and a matrix resin composition with the weight per square meter of the reinforcing fibers being 250-2,000 g/m2. The production method comprises the following steps (1)-(3): (1) a matrix resin composition blending step for obtaining a matrix resin composition by mixing an epoxy resin, a radically polymerizable unsaturated compound, an epoxy resin curing agent and a polymerization initiator that generates radicals, in said step the content of the radically polymerizable unsaturated compound relative to 100% by mass of the total of the epoxy resin and the radically polymerizable unsaturated compound being 10-25% by mass; (2) a matrix resin composition impregnating step; and (3) a surface viscosity increasing step.

Abstract: Provided is a method for producing a good epoxy resin composition for obtaining fiber-reinforced plastics. A production method for obtaining a fiber-reinforced composite material by impregnating a fiber assembly with an epoxy resin composition and then curing the epoxy resin composition, wherein the epoxy resin composition contains a component [A], a component [B] and a component [C] respectively satisfying the conditions described below. When the blending amount of the component [B] is set to b parts by mass and the blending amount of the component [C] is set to c parts by mass relative to 100 parts by mass of the component [A] contained in the epoxy resin composition, formula (2) is satisfied within the range of formula (1), formula (4) is satisfied within the range of formula (3), and formula (6) is satisfied within the range of formula (5).

Abstract: A resin composition that has good heat resistance and handleability and that can produce a prepreg which has a good balance between tackyness and drapability and which causes little resin flow during prepreg molding, a prepreg that is manufactured using the resin composition, and a fiber-reinforced composite are provided. A resin composition that contains a maleimide compound, diallyl bisphenol A, and a diallyl isophthalate polymer, a prepreg in which reinforcing fibers are impregnated with the resin composition, and a fiber-reinforced composite material that is obtained by molding the prepreg are provided.

Abstract: The present invention relates to a prepreg which is free from the phenomenon that air is trapped between layers to generate voids, has good handling characteristics and can produce molded articles having any complicated shape and also relates to a method of producing the prepreg. A reinforced-fiber sheet is impregnated with a matrix resin so as to form a continuous resin layer at least in the inside thereof, and then, a protective film having an irregular surface is applied to at least one surface of the reinforced-fiber sheet impregnated with the matrix resin such that the irregular surface faces the reinforced-fiber sheet. In this state, the prepreg is allowed to leave at 30 to 60° C. under the atmosphere for 12 hours or more.

Abstract: A composition useful as a matrix for fiber-reinforced composites possesses a viscosity at 25° C. of no more than 1000 mPa·s and provides a cured product displaying a breaking elongation of at least 5%. The composition comprises (A) at least one of a bisphenol epoxy resin (A1) and a phenol novolak epoxy resin (A2), a polyvalent epoxy resin formed from a mononuclear aromatic backbone (B), an aromatic amine curing agent (C), and a rubber (D).

Abstract: The present invention relates to a prepreg which is free from the phenomenon that air is trapped between layers to generate voids, has good handling characteristics and can produce molded articles having any complicated shape and also relates to a method of producing the prepreg. A reinforced-fiber sheet is impregnated with a matrix resin so as to form a continuous resin layer at least in the inside thereof, and then, a protective film having an irregular surface is applied to at least one surface of the reinforced-fiber sheet impregnated with the matrix resin such that the irregular surface faces the reinforced-fiber sheet. In this state, the prepreg is allowed to leave at 30 to 60° C. under the atmosphere for 12 hours or more.

Abstract: An epoxy resin composition according to the present invention is an epoxy resin composition with a viscosity at 25° C. of no more than 1000 mPa·s, incorporating (A) at least one of a bisphenol type epoxy resin (A1) and a phenol novolak type epoxy resin (A2), a polyvalent epoxy resin formed from a mononuclear aromatic backbone (B) and an aromatic amine curing agent (C), wherein a cured product produced by curing the epoxy resin composition displays a breaking elongation of at least, 5%. The epoxy resin composition has a low viscosity at room temperature which can be sustained with good stability for long periods. Furthermore, a cured product produced by curing the epoxy resin composition displays excellent heat resistance and mechanical characteristics, and is consequently ideally suited for use as a matrix resin for fiber reinforced composite materials.

Abstract: A composition useful as a matrix for fiber-reinforced composites possesses a viscosity at 25° C. of no more than 1000 mPa's, and provides a cured product displays a breaking elongation of at least 5%. The composition comprises (A) at least one of a bisphenol epoxy resin (A1) and a phenol novolak type epoxy resin (A2), a polyvalent epoxy resin formed from a mononuclear aromatic backbone (B), and an aromatic amine curing agent (C).

Abstract: Epoxy resin compositions comprising (a) an epoxy resin, (b) a latent curing agent with curing power at 100° C. or below and (c) an aromatic amine-based curing agent and/or an alicyclic amine-based curing agent, which are curable in two stages, or epoxy resin compositions further comprising (d) a curing accelerator, as well as a prepregs comprising reinforcing fiber materials impregnated with the epoxy resin compositions. The compositions give die-releasable cured products by primary curing at low temperature, give highly heat-resistant cured products by secondary curing, and exhibit satisfactory stability at room temperature.

Abstract: A preform can be molded by resin transfer molding and yields a composite material having excellent strength and excellent interlaminar debonding resistance. The preform, which is for producing a fiber-reinforced composite, comprises layers of laminated structure of a reinforcing material comprising reinforcement fibers and has, between these layers, a layer comprising a thermoplastic resin and having space so as not to inhibit a liquid resin from flowing therethrough. The preform is molded to yield a fiber-reinforced composite material.

Abstract: A preform can be molded by resin transfer molding and yields a composite material having excellent strength and excellent interlaminar debonding resistance. The preform, which is for producing a fiber-reinforced composite, comprises layers of laminated structure of a reinforcing material comprising reinforcement fibers and has, between these layers, a layer comprising a thermoplastic resin and having space so as not to inhibit a liquid resin from flowing therethrough. The preform is molded to yield a fiber-reinforced composite material.

Abstract: Epoxy resin compositions comprising (a) an epoxy resin, (b) a latent curing agent with curing power at 100° C. or below and (c) an aromatic amine-based curing agent and/or an alicyclic amine-based curing agent, which are curable in two stages, or epoxy resin compositions further comprising (d) a curing accelerator, as well as a prepregs comprising reinforcing fiber materials impregnated with the epoxy resin compositions. The compositions give die-releasable cured products by primary curing at low temperature, give highly heat-resistant cured products by secondary curing, and exhibit satisfactory stability at room temperature.

Abstract: The object of the present invention is to provide a carbon-fiber-reinforced resin composite material, and a partition structure using the same, having superior strength and heat resistance, and which do not result in the occurrence of leakage due to cracking even when cooled to low temperatures. In the present invention, a carbon-fiber-reinforced resin composite material is used for which the amount of leakage in a helium gas leak test after loading for 30 minutes at a strain of 6000&mgr; in liquid hydrogen being 1×10−9 Ncm3/cm2/s or less. The carbon-fiber-reinforced resin composite material is also a carbon-fiber-reinforced resin composite material having an epoxy resin composed of a homogeneous phase for the matrix resin, wherein the glass transition temperature is 150° C. or higher, the fracture elongation of a 90° tensile test is 1.

Abstract: An epoxy resin composition according to the present invention is an epoxy resin composition with a viscosity at 25° C. of no more than 1000 mPa· s, incorporating (A) at least one of a bisphenol type epoxy resin (A1) and a phenol novolak type epoxy resin (A2), a polyvalent epoxy resin formed from a mononuclear aromatic backbone (B) and an aromatic amine curing agent (C), wherein a cured product produced by curing the epoxy resin composition displays a breaking elongation of at least 5%.