PRODUCTION OF POLYOLEFIN-BASED RESIN PREEXPANDED PARTICLE

摘要

PROBLEM TO BE SOLVED: To provide a method for production by which mutual fusion of expanded particles and a rise in open-cell ratio of preexpanded particles are simultaneously prevented to increase the expansion efficiency and polyolefin-based resin preexpanded particles having a high expansion ratio can be produced. SOLUTION: The relationship between a temperature for thermally expanding expanded particles and the amount of a fusion preventing agent sticking to the surfaces of the polyolefin-based resin expanded particles is represented by the formula (t)-TV<=49.1C-27.0 [(t) is the temperature for the thermally expanding the expanded particles; C is the amount of the fusion preventing agent sticking to the surfaces of the polyolefin-based resin expanded particles; TV is the saddle part temperature between the peaks indicating two melting points in a differential scanning calorimetry(DSC) curve obtained by the DSC] and (t) is further a temperature range represented by the formula TL-30<=(t)<=TV (TV is the same as that described above; TL is the melting point on the low-temperature side in the two melting points) in a method for imparting expandability to the polyolefin-based resin expanded particles having a crystal structure manifesting the two melting point in the DSC curve and thermally expanding the expanded particles having the expandability imparted thereto.