| 摘要 |
PURPOSE:To provide a polypropylene random copolymer-based film causing no spoilage of its appearance due to bleed whitening, highly excellent in balance between low-temperature heat sealability and rigidity. CONSTITUTION:The objective polypropylene random copolymer composed of (A) 92.3-75.0wt.% of propylene, (B) 0-2.7wt.% of ethylene and (C) 5.0-25.0wt.% of alpha-olefin, can be obtained by copolymerization between propylene, ethylene and an alpha-olefin using a Ziegler-Natta catalyst in the virtual absence of solvent. The 20 deg.C xylene-soluble content of this copolymer falls within a specific range. The other objective film can be obtained by melt extrusion of the above copolymer. |
