Patent attributes
A prepreg having low dielectric constant, low dielectric loss, and high heat cycle resistance. The prepreg includes a sheet-like preform and a resin-impregnated, sheet-like, fiber-reinforced material thermal pressure adhered to the sheet-like preform. The sheet-like preform includes a graft copolymer (a) in which 15 to 40 parts by mass of an aromatic vinyl monomer are grafted to 60 to 85 parts by mass of a random or block copolymer comprising monomer units selected from nonpolar α-olefin monomers and nonpolar conjugated diene monomers. The resin-impregnated, sheet-like, fiber-reinforced material includes a sheet-like, fiber-reinforced material (b1) and a thermoplastic resin (b2) into which the sheet-like, fiber-reinforced material (b1) is impregnated. The thermoplastic resin (b2) is a random or block copolymer composed of 60 to 90 mass % of a monomer unit, which is selected from nonpolar α-olefin monomers and nonpolar conjugated diene monomers, and 10 to 40 mass % of an aromatic vinyl monomer unit.