| 摘要 |
PROBLEM TO BE SOLVED: To obtain a foamed polyolefinic resin molding having a small difference between the density of the surface part and that of the central part and being excellent in properties such as a rate of fusion, mechanical strengths and appearance. SOLUTION: Pre-expanded particles which have such a crystal structure that two melting points appear in the measurement with a differential scanning calorimeter and in which the heat of the endothermic peak of the high- temperature side melting point is 0.3-6.0 cal/g, at least 300, per mm<2> , fine cells having a diameter of 0.5-50μm are present on the surface part of the pre- expanded particles, and the mean cell diameter in the central part is 100-1,000μm are subjected to in-mold molding to obtain an expanded polyolefin resin molding having a rate of fusion of at least 50%, having such a crystal structure that two melting points appear in the measurement with a differential scanning calorimetry and having a ratio of the density on the surface part to that of the central part of 0.8-1.0.
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