| 摘要 |
PURPOSE: To obtain high-quality expanded particles which have almost an invariable expansion ratio even when the expanding temperature somewhat varies, is excellent in moldability, etc., because the temperature control in the expansion step is easy and the expansion ratio is constant, and have a high expansion ratio. CONSTITUTION: In the expanded polypropylene resin particles, the resin contains 3-10wt.% ethylene and/or butene-1 as comonomer component, the ratio Mz/Mw is 1.5-2.5 (wherein Mz is the Z-average molecular weight of the resin, and Mw is its weight-average molecular weight, and the expanded resin particles have secondary crystals having a melting energy of 11-30J/g. |
