METHOD FOR USING POLYPROPYLENE IN ORDER TO IMPROVE ITS STABILITY AGAINST IONIZING RADIATION

摘要

PROBLEM TO BE SOLVED: To obtain a polypropylene having improved stability against an ionizing radiation without using an extremely large amount of foreign substances by using a specified highly amorphous polypropylene as the additive for a specified highly isotactic polypropylene. SOLUTION: A highly amorphous polypropylene having a melting enthalpy of at most 40J/g and an MFI of 0.1-100g/10min is used as the additive for a highly isotactic polypropylene. The highly amorphous polypropylene is propylene homopolymer or a copolymer comprising propylene and at least oneα-olefin and having a propylene content of at least 80mol%. The highly isotactic polypropylene is a propylene homopolymer or a copolymer comprising propylene and at least oneα-olefin and having a propylene content of at least 50mol%.