Abstract: A prepreg and an integrally molded article are described, the prepreg including a thermoplastic resin existing on one face of a layer in which reinforcing fibers are impregnated with a thermosetting resin, wherein the prepreg exhibits, in injection molding or press molding, thermal weldability with a member containing a thermoplastic resin, and wherein the thermosetting resin has a specific peak on a loss tangent (tan ?) curve obtained by dynamic mechanical analysis (DMA), so that the prepreg exhibits suitable flexibility and adhesiveness, excellent formability on a complicated mold face, and adhesion to a mold face, causes no positional shift, and can be efficiently reinforced and stiffened at an intended position.

Abstract: An object of the present invention is to provide a prepreg and a laminate for producing a laminate suitable as a structural material, which have excellent joining strength and can be firmly integrated with another structural member by welding. The present invention provides a prepreg including the following structural components: [A] reinforcing fibers, [B] a thermosetting resin, and [C] a thermoplastic resin, wherein [A] has a surface free energy, measured by a Wilhelmy method, of 10 to 50 mJ/m2, [C] is present on a surface of the prepreg, and the reinforcing fibers [A] are present, which are included in a resin area including [B] and a resin area including [C] across an interface between the two resin areas.