| 摘要 |
PROBLEM TO BE SOLVED: To obtain foaming particles of a polypropylene-based resin capable of forming in a high density by neither using a specific pre-treatment nor a specific facility and not requiring a post-treatment and to provide a method for its production and a method for forming in a mold using the particles. SOLUTION: The foaming particles of a polypropylene-based resin having 80-500g/l bulk density have each a crystal structure showing two peaks in a DSC curve obtained by the measurement of the differential scanning calorimetry of the particles, of which peak in the high temperature side is located at a temperature higher than that of the completion of melting of the base resin, having 20-30J/g heat value of the peak. The production method thereof is to disperse the particles of the base resin into water in a hermetically sealed container, supply a volatile foaming agent into the sealed container, heat the dispersion liquid and discharge the content in the sealed container to atmosphere having a lower pressure than that in the container. |
