Patent ID: 8518540

Claim:
Expanded polypropylene resin beads, which are multilayer resin expanded beads formed by foaming and expanding multilayer resin beads comprising: a core layer formed of a polypropylene resin, and a coating layer formed of another polypropylene resin that is different from the polypropylene resin forming the core layer, the another polypropylene resin being capable of being molded at a steam pressure lower than a molding steam pressure of equivalent single layer expanded beads formed by foaming and expanding a single layer of resin beads formed by the polypropylene resin of the core layer, wherein a resin weight ratio of the coating layer and the core layer (weight of the another polypropylene resin/weight of the polypropylene resin) in the multilayer resin beads is from 0.001 to 0.040, and an average value of a thickness of the coating layer of the expanded polypropylene beads is from 0.1 μm to 3.0 μm.