Abstract: A prepreg containing a matrix resin containing: a polyetherimide resin (A) having a repeating unit represented by General Formula (A); and carbon fibers, in which the matrix resin satisfies Condition (1). Condition (1): A tensile elongation at break (T1) of a film, obtained by extrusion-molding the matrix resin into a film shape, in a TD direction, and a tensile elongation at break (T2) of the film in the TD direction after immersing of the film for 1,000 hours in a specific oil at 23° C. are measured, and a tensile elongation retention rate obtained by Expression (1) is 15% or greater and 90% or less. Tensile Elongation Retention Rate=(Tensile Elongation at Break (T2)/Tensile Elongation at Break (T1))×100 . . . (1) (in Formula (a), m is a number of 5 to 1,500.

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: A fiber-reinforced composite material includes a matrix resin, and reinforcing fibers, in which the matrix resin includes a polyaryl ketone resin and a resin having a nitrogen atom in a repeating structural unit. A surface of the fiber-reinforced composite material includes a portion in which a contact angle with water is 60° or less.

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: Provided is a method of manufacturing a FRP product that is obtained by integrally curing a prepreg where fibers are arranged in a specific direction, such as a unidirectional prepreg, a cloth prepreg, or a tow prepreg and a chopped fiber prepreg, such as a sheet molding compound, in which disorder of fiber arrangement in a portion obtained by curing the prepreg is suppressed to obtain an expected strength.

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 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: There are provided a method of producing a laminate that is used to produce a fiber-reinforced composite material molded product having a complex shape, and a method of producing a fiber-reinforced composite material molded product having excellent appearance and mechanical characteristics and having a complex shape. The method of producing a laminate according to the present invention includes, in an assembly (50) having at least one selected from the group consisting of an abutment part in which ends of sheet-like prepregs are abutted so that side end surfaces come in contact with each other and an overlapping part in which ends of sheet-like prepregs overlap, laminating a sheet molding compound on at least a part of one or both of the abutment part and the overlapping part in an overlapping manner.

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).