| 摘要 |
A multimodal polymer composition made using Ziegler-Natta catalyst comprising: (A) a polypropylene homopolymer or a propylene random copolymer comprising propylene and up to 5 wt% of comonomer selected from ethylene and/or Calpha olefin; and (B) a random copolymer of propylene and comonomer selected from ethylene and/or Calpha olefin different from polymer (A); wherein the total comonomer content of the polymer composition is at least 0.5 wt%, ethylene content is more than 2.5 wt%, and the melt flow rate of the polymer blend is from 11 to 30 g/10 min when measured according to ISO 1133 at 230°C and a load of 2.16 kg. Use of a multimodal polymer composition for the manufacture of a film or article by blow moulding, film blowing, film casting or ISBM. A process for the preparation of a multimodal polymer composition comprising in a first slurry stage polymerising propylene and optionally ethylene and/or Calpha olefin in the presence of a Ziegler-Natta catalyst so as to form polymer (A), transferring the product mixture to a gas phase reactor and subsequently polymerising propylene and ethylene and/or Calpha olefin so as to form polymer (B), wherein the total comonomer content of the polymer composition is at least 0.5 wt% and the melt flow rate of the polymer blend is from 11 to 30 g/10 min when measured according to ISO 1133 at 230°C and a load of 2.16 kg. A moulded article comprising a multimodal polymer composition and a process for the preparation thereof, the process comprising injection moulding said composition to prepare a preform and subsequently biaxially stretching and blowing the preform at a temperature below the melting point of the polymer. Furthermore, an article having biaxial molecular orientation and comprising said composition. |
