Patent ID: 11965084
Assignee: JSP CORPORATION
Field: Other special machines (Mechanical engineering)
Classification: CPC B  C  Y | IPC C

Claim 0:
1. A method for producing a polypropylene-based resin foamed molded article, comprising
extruding a foamable molten resin, obtained by kneading a base resin and a physical blowing agent, through a die to form a foamed parison, and
blow molding the foamed parison,
wherein said base resin comprises a branched polypropylene-based resin (A), a linear polypropylene-based resin (B) and a recovered raw material (C) that is recovered in the course of production of the polypropylene-based resin foamed molded article,
wherein the branched polypropylene-based resin (A) has a melt tension (230° C.) of greater than 100 mN and a melt flow rate (230° C., load of 2.16 kg) of 0.1 to 15 g/10 min,
the linear polypropylene-based resin (B) has a melt tension (230° C.) of less than 30 mN (not inclusive of 0) and a melt flow rate (230° C., load of 2.16 kg) of 5 to 25 g/10 min,
the recovered raw material (C) has a melt tension (230° C.) of 5 to 50 mN and a melt flow rate (230° C., load of 2.16 kg) of 2 to 50 g/10 min, and
wherein a difference (TmA−TmB) between a melting point TmA of the branched polypropylene-based resin (A) and a melting point TmB of the linear polypropylene-based resin (B) is −5° C. to 5° C.,
a difference (TcA−TcB) between a crystallization temperature TcA of the branched polypropylene-based resin (A) and a crystallization temperature TcB of the linear polypropylene-based resin (B) is 0 to 10° C.,
a mixing amount of the branched polypropylene-based resin (A) in the base resin is 5% by weight or more and less than 20% by weight based on 100% by weight of the base resin and a mixing amount of the recovered raw material (C) in the base resin is more than 65% by weight and 90% by weight or less based on 100% by weight of the base resin, and
a weight ratio (A:B) of the mixing amount of the branched polypropylene-based resin (A) to a mixing amount of the linear polypropylene-based resin (B) in the base resin is 80:20 to 40:60.