| 摘要 |
PURPOSE:Expanded particles having an excellent in-mold moldability and capable of forming a low-density (high expansion ratio) molding of low shrinkage and water absorption, having a crystal structure which gives a DSC curve having a peak characteristic of a PP resin and a high-temperature peak of the side of a temperature higher than that of the former. CONSTITUTION:Expanded PP resin particles having a crystal structure which, when analyzed by differential scanning colorimetry, gives a DSC curve (a DSC curve obtained when 1-3mg of the expanded PP resin particles are heated to 220 deg.C on a differential scanning colorimeter at a rate of temperature increase of 10 deg.C/min) having a peak characteristic of PP resin and a high-temperature peak on the side of a temperature higher than that of the former peak, preferably by at least 5 deg.C. The resin particles have an excellent in-mold moldability. By specifying the expansion temperature at a temperature which is lower than Tm and lies between Tm-25 deg.C and Tm-5 deg.C, wherein Tm is the temperature at which melting is finished, it is possible to obtain these expanded particles having a structure which gives a DSC curve having the characteristic peak and the high- temperature peak.
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