Patent ID: 8758874

Claim:
A laminated base material comprising a lamination and integration of prepreg base materials each of which comprises a multiplicity of reinforcing fibers arranged substantially in one direction and a matrix resin adhered to said reinforcing fibers, wherein 1) at least one of said laminated prepreg base materials is formed with a prepreg base material having, throughout its whole surface, a multiplicity of incisions each extending in a direction crossing the reinforcing fibers, substantially all of the reinforcing fibers are divided by incisions, 2) a length L of each of reinforcing fiber segments formed by the incisions is 10 to 100 mm, a thickness H of the prepreg base material is 30 to 300 μm, and a fiber volume content Vf of the reinforcing fibers is 45 to 65%, and arranging directions of said reinforcing fibers between one and another laminated prepreg base materials have at least two directions different from each other, and 3) each of said incisions is in the form of a slit segment having a selected length, and when said slit segment is projected in the arranging direction of said reinforcing fibers, a projected length Ws of said slit segment in the perpendicular direction of said reinforcing fibers is 30 μm to 1.5 mm.