| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of an in-mold expansion molded product which permits ready acquisition of an in-mold expansion molded product having excellent mechanical properties and a small permanent compression set even by molding polypropylene resin expandable particles using a low-pressure steam (molding vapor pressure). SOLUTION: The manufacturing method of the in-mold expansion molded product comprises filling polypropylene resin expandable particles comprising as the base resin a propylene polymer satisfying the following requirements (a) and (b) in a mold and subsequently heating the expandable particles in the mold to cause them to fuse with one another. (a) The propylene polymer contains 100-85 mol% of a structural unit obtained from propylene and 0-15 mol% of a structural unit obtained from ethylene and/or 4-20Cα-olefins. (b) The ratio of position irregular units based on 2,1-insertion is 0.5-2.0% and the ratio of position irregular units based on 1,3-insertion is 0.005-0.4% in the whole propylene insertion. COPYRIGHT: (C)2005,JPO&NCIPI |
