| 摘要 |
Multilayer expanded polypropylene resin beads that are heat moldable at low steam pressure and can provide an expanded mold with sufficient rigidity and heat resistance. The beads are formed from a polypropylene resin and a coating layer formed from a different polypropylene resin. The multilayer expanded resin beads can be molded in-mold at a steam pressure lower than the steam pressure for molding single-layer expanded beads made from the polypropylene resin which forms the core layer. The coating layer to core layer resin weight ratio in the multi-layer resin beads is not less than 0.001 and not greater than 0.040 and the expansion ratio of the expanded beads, the average value of the thickness of the coating layer of the expanded beads, calculated based on the coating weight ratio of the multi-layer resin beads, is not less than 0.1 μm and not greater than 3.0 μm. |
