Patent ID: 8569390

Claim:
A polypropylene resin pre-expanded particle comprising a base resin that has a MFR of 5 g/10 min or more and 20 g/10 min or less and a melting point of 140° C. or higher and 155° C. or lower, wherein the base resin is a mixture containing: 70 percent or more and 95 percent or less by weight of a polypropylene resin (A) having a MFR of 10 g/10 min or more and 30 g/10 min or less and a molecular weight distribution Mw/Mn of 6 or less, and containing 1-butene as a comonomer; and 5 percent or more and 30 percent or less by weight of a polypropylene resin (B) having a MFR of 0.1 g/10 min or more and 3 g/10 min or less, and the base resin exhibits a relationship between a heat of crystal fusion and the resin melting point determined with a differential scanning calorimeter satisfying conditional formula (1): [Heat of crystal fusion (J/g)]≧1.2×[Melting point (° C.)]−96 (1).