| 摘要 |
The present invention in a first embodiment concerns a multimodal, preferably bimodal, polyethylene composition comprising a base resin which comprises (A) a first ethylene homo- or copolymer fraction, and (B) a second ethylene homo- or copolymer fraction,
wherein fraction (A) has a lower molecular weight than fraction (B), the ratio of the MFR 2 of fraction (A) and the MFR 5 of the base resin being at least 50 and the composition has a white spot area of 1 % or below. In a second embodiment, the present invention concerns a polyethylene composition comprising a base resin comprising (A) a first ethylene homo- or copolymer fraction, and (B) a second ethylene homo- or copolymer fraction,
wherein fraction (A) has a lower molecular weight than fraction (B), the ratio of the MFR 2 of fraction (A) and the MFR 5 of the base resin being at least 50 and the composition has a rating in the ISO 18553 white spot rating test of below 4.5. Furthermore, the present invention relates to a process for the production of said compositions as well as to the use of said compositions for the production of an article, in particular a pipe.
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