METHOD FOR PRODUCING POLYPROPYLENE-BASED RESIN FOAMED BLOW-MOLDED ARTICLE

摘要

Provided is a method that can improve formability and blow moldability of a foamed parison as compared with conventional production method and can produce a polypropylene-based resin foamed blow-molded article having excellent uniformity of wall thickness over a wide range of its density. The method comprises kneading a polypropylene-based resin with a physical foaming agent, extruding the thus obtained foamable molten resin through a die to obtain a foamed parison in a softened state, placing the foamed parison between molds and then blow-molding the foamed parison and is characterized in that the polypropylene-based resin comprises a polypropylene-based resin (A) satisfying specific requirements (1) to (3) and a polypropylene-based resin (B) satisfying a specific requirement (4), when the polypropylene-based resins (A) and (B) are each subjected to dynamic viscoelasticity measurement in which an oscillation strain is applied thereto at a temperature of 190°C, and that the mixing ratio by weight (A:B) of the resin (A) to the resin (B) is in the range of 100:0.5 to 100:5.