| 摘要 |
The present invention relates to a polyethylene composition for pipe applications comprising a base resin having a density of more than 952.0 kg/m3 and equal to or less than 957.0 kg/m3, wherein the composition has a MFR5 of 0.12 to 0.21 g/10min and the composition and/or the base resin has a polydispersity index PI within the range of equal to or higher than 3.5 Pa-1 and equal to or less than 4.9 Pa-1, and to a polyethylene composition obtainable by a multistage process, the multistage process comprising polymerizing ethylene in the presence of a silica supported Ziegler Natta catalyst in a loop reactor, transferring an intermediate material to a gas phase reactor, feeding ethylene and comonomer to the gas phase reactor for obtaining a base resin, and finally extruding the base resin together with stabilizers and carbon black into the polyethylene composition. The invention further concerns articles, preferably pipes, made from the inventive polyethylene composition and the use of the inventive polyethylene composition for the production of an article. |
