Abstract: A prepreg sheet includes a plurality of prepreg tapes each of which overlaps with a corresponding adjacent prepreg tape for a suitable overlapping length. The plurality of prepreg tapes each contain a reinforcing fiber bundle that is impregnated with a thermosetting resin composition. According to a method for manufacturing a preform, for example, a primary premolded article is manufactured by preforming an intermediate base material containing a reinforcing fiber base material and a matrix resin composition, and a secondary premolded article is manufactured by preforming the primary premolded article on which the intermediate base material is further placed.

Abstract: Provided is a thermosetting resin composition which achieves both high heat resistance and high bending strength as a fiber-reinforced composite material, and also has rapid curability that enables high cycle press forming, thermal stability, and storage stability. The thermosetting resin composition of the present invention is a thermosetting resin composition comprising an epoxy resin, an epoxy resin curing agent, an imidazole compound, and an epoxy resin curing accelerator, in which the epoxy resin curing agent is dicyandiamide or a derivative thereof, and the epoxy resin curing accelerator comprises a urea derivative having two or more dimethylureido groups in a molecule.

Abstract: A sheet molding compound which is a thickened material of an epoxy resin composition, including a component (A), a component (B), and a component (C), in which the component (A) is an epoxy resin staying at a liquid state at 25° C., the component (B) is an acid anhydride, the component (C) is an epoxy resin curing agent, and in the thickened material, at least some of epoxy groups of the component (A) and at least some of carboxy groups derived from the component (B) form ester.

Abstract: A prepreg sheet (1) is formed by stacking a plurality of unit layers (10a, 10b) In the unit layers (10a, 10b), prepreg tapes (100), in which a reinforced fiber bundle is impregnated with a thermosetting matrix resin composition, are disposed in rows a plurality of times. One or more of the unit layers (10a, 10b) has a gap (G) between adjacent prepreg tapes (100), and the width thereof is 10% or less of the width of the narrower of the adjacent prepreg tapes (100).

Abstract: A prepreg may include: a reinforcing fiber material including carbon fibers; and a resin composition with which the reinforcing fiber material is impregnated. The resin composition may include an epoxy resin (A), an amine curing agent (B), and an imidazole curing agent (C). The amine curing agent (B) may be present in a range of from 1 to 3.8 parts by mass, relative to 100 parts by mass of the epoxy resin (A). The amine curing agent (B) and the imidazole curing agent (C) may be present in a total amount of not more than 10 parts by mass, relative to 100 parts by mass of the epoxy resin (A). The imidazole curing agent may include an imidazole compound including, in its molecular structure, a triazine ring.

Abstract: A prepreg contains: a reinforcing fiber material; and a resin composition with which the reinforcing fiber material is impregnated. The resin composition contains an epoxy resin, an amine curing agent, and an imidazole curing agent. An amount of the amine curing agent is less than or equal to 3.8 parts by mass, relative to 100 parts by mass of the epoxy resin, and a sum of the amount of the amine curing agent and an amount of the imidazole curing agent is less than or equal to 10 parts by mass, relative to 100 parts by mass of the epoxy resin. The fiber-reinforced composite material is a cured product of the prepreg.

Abstract: A thermosetting resin composition (C) of which curing can be started at a relatively low temperature in a short time and a cured product exhibits high heat resistance, the thermosetting resin composition (C) comprising an epoxy resin; an epoxy resin curing agent; and an epoxy resin curing accelerator, wherein the epoxy resin curing agent contains an imidazole-based curing agent 1 which is not encapsulated in a microcapsule and a curing agent 2 which is encapsulated in a microcapsule, and the epoxy resin curing accelerator comprises a urea derivative.

Abstract: Provided is a thermosetting resin composition (C) of which curing can be started at a relatively low temperature in a short time and a cured product exhibits high heat resistance, the thermosetting resin composition (C) comprising an epoxy resin; an epoxy resin curing agent; and an epoxy resin curing accelerator, wherein the epoxy resin curing agent contains an imidazole-based curing agent 1 which is not encapsulated in a microcapsule and a curing agent 2 which is encapsulated in a microcapsule, and the epoxy resin curing accelerator comprises a urea derivative.

Abstract: A method for manufacturing a fiber-reinforced composite material molded article of the present invention includes a step of causing a reinforcing fiber base material to undergo deformation with use of a mold, the reinforcing fiber base material including: reinforcing fibers which are unidirectionally oriented; and a matrix resin composition. The reinforcing fiber base material has a cut in a zone which is to undergo shear deformation and/or compressive deformation, the cut being substantially parallel to an orientation direction of the reinforcing fibers, and has substantially no cut that cuts through a fiber.

Abstract: The present invention realizes the production of a molded composite article that has superior appearance, that is capable of preventing or reducing a deterioration of mechanical properties, and that is superior in productivity. A sheet of a unidirectional material is fixed to a specific part of a lower mold, a force in an out-of-plane direction is applied to a specific part of a zone of the sheet which zone is to undergo shear deformation or compressive deformation, and the sheet is preformed, thereby obtaining a preform. Heat and pressure are applied to the preform in a mold, thereby obtaining a molded composite article having a desired shape.

Abstract: A molding material that enables acquirement of a fiber-reinforced composite material which has excellent demoldability from a mold and excellent surface appearance, which contaminates a mold surface after molding less, and which has excellent mechanical properties and heat resistance; and a fiber-reinforced composite material which has excellent demoldability from a mold and surface appearance, which contaminates a mold surface after molding less, and which has excellent mechanical properties and heat resistance, are provided. A molding material of the present invention includes a component (A): an epoxy resin; a component (B): an epoxy resin curing agent; a component (C): a compound that has a solubility parameter of 11.2 or less and a melting point of 115° C. or lower; and a reinforcement fiber.

Abstract: An object of the present invention is to provide a molding material which can suppress film lifting, gives good peelability of release paper, and can produce therefrom a fiber-reinforced composite article with good demoldability from a metal mold, and a fiber-reinforced composite article. The molding material of the present invention comprises an epoxy resin composition comprising a component (A): an epoxy resin, a component (B): an epoxy resin curing agent, and a component (C): an unsaturated fatty acid ester compound having a melting point or pour point of 25° C. or lower; and a reinforcing fiber substrate, wherein the reinforcing fiber substrate is impregnated with the epoxy resin composition.

Abstract: Provided is a thermosetting resin composition which achieves both high heat resistance and high bending strength as a fiber-reinforced composite material, and also has rapid curability that enables high cycle press forming, thermal stability, and storage stability. The thermosetting resin composition of the present invention is a thermosetting resin composition comprising an epoxy resin, an epoxy resin curing agent, an imidazole compound, and an epoxy resin curing accelerator, in which the epoxy resin curing agent is dicyandiamide or a derivative thereof, and the epoxy resin curing accelerator comprises a urea derivative having two or more dimethylureido groups in a molecule.

Abstract: Provided is a thermosetting resin composition which achieves both high heat resistance and high bending strength as a fiber-reinforced composite material, and also has rapid curability that enables high cycle press forming, thermal stability, and storage stability. The thermosetting resin composition of the present invention is a thermosetting resin composition comprising an epoxy resin, an epoxy resin curing agent, an imidazole compound, and an epoxy resin curing accelerator, in which the epoxy resin curing agent is dicyandiamide or a derivative thereof, and the epoxy resin curing accelerator comprises a urea derivative having two or more dimethylureido groups in a molecule.

Abstract: A prepreg sheet includes a plurality of prepreg tapes each of which overlaps with a corresponding adjacent prepreg tape for a suitable overlapping length. The plurality of prepreg tapes each contain a reinforcing fiber bundle that is impregnated with a thermosetting resin composition. According to a method for manufacturing a preform, for example, a primary premolded article is manufactured by preforming an intermediate base material containing a reinforcing fiber base material and a matrix resin composition, and a secondary premolded article is manufactured by preforming the primary premolded article on which the intermediate base material is further placed.

Abstract: The invention provides an epoxy resin composition that is easily B-staged despite containing an epoxy resin inherently difficult to B-stage, has a long pot life, has excellent processability and storage stability after B-staging, and make it possible to obtain a fiber-reinforced composite material having excellent flexural strength and flexural modulus. A molding material, including a thickened product of an epoxy resin composition; and a reinforcing fiber; wherein the epoxy resin composition including: a component (A): an aromatic epoxy resin; a component (B): an alicyclic diamine; a component (C): an epoxy resin curing agent that is not an alicyclic diamine; and a component (D): an aliphatic epoxy resin, wherein, when the viscosity at 25° C. immediately after preparation of the epoxy resin composition is taken as (a) and the viscosity at 25° C. after three hours from the preparation is taken as (b), the epoxy resin composition satisfies: (a)=0.1 to 25 Pa·s; (b)=0.1 to 25 Pa·s; and (b)/(a)?5.

Abstract: A prepreg contains: a reinforcing fiber material; and a resin composition with which the reinforcing fiber material is impregnated. The resin composition contains an epoxy resin, an amine curing agent, and an imidazole curing agent. An amount of the amine curing agent is less than or equal to 3.8 parts by mass, relative to 100 parts by mass of the epoxy resin, and a sum of the amount of the amine curing agent and an amount of the imidazole curing agent is less than or equal to 10 parts by mass, relative to 100 parts by mass of the epoxy resin. The fiber-reinforced composite material is a cured product of the prepreg.

Abstract: What is provided is a molding device which enables a molded article to be excellently released, has a region that is on a molding surface and exhibits excellent abrasion resistance by being treated to show mold release properties, and can suppress the deterioration of mold release properties. Also provided is a method for manufacturing a fiber-reinforced composite material molded article. A fiber-reinforced composite material molding device (101) includes a molding die (130) for obtaining a fiber-reinforced composite material molded article by molding a fiber-reinforced composite material prepared by impregnating a reinforcing fiber base material with a resin composition, in which a surface free energy of a portion or the entirety of cavity surfaces (113a) and (123a) of the molding die (130) is equal to or lower than 25.0 mJ/m2 which is measured by a three liquid method.

Abstract: Provided is a thermosetting resin composition which achieves both high heat resistance and high bending strength as a fiber-reinforced composite material, and also has rapid curability that enables high cycle press forming, thermal stability, and storage stability. The thermosetting resin composition of the present invention is a thermosetting resin composition comprising an epoxy resin, an epoxy resin curing agent, an imidazole compound, and an epoxy resin curing accelerator, in which the epoxy resin curing agent is dicyandiamide or a derivative thereof, and the epoxy resin curing accelerator comprises a urea derivative having two or more dimethylureido groups in a molecule.

Abstract: This prepreg comprises reinforcing fibers and a matrix resin composition. The matrix resin composition comprises at least an epoxy resin (component (A)), a radical polymerizable unsaturated compound (component (B)), and a polymer formed by radical polymerization of the component (B) (component (E)).