| 摘要 |
A multimodal polymer composition for fiber optical cables and a fiber optical cable comprising the composition are disclosed. The composition is characterized in that it comprises a multimodal polyethylene with a density of 0.920-0.965 g/cm3 and a viscosity at a shear stress of 2.7 kPa (eta2.7kPa) of at least 150 kPa.s, said multimodal polyethylene comprising a low molecular weight (LMW) ethylene homo- or copolymer fraction and a high molecular weight (HMW) ethylene copolymer fraction, said multimodal polymer composition having a weight ratio of the LMW fraction to the HMW fraction of (35-55):(65-45). Preferably, the multimodal polyethylene is a bimodal polyethylene and has a shear thinning index (SHI), defined as the ratio of the viscosities at shear stresses of 2.7 and 210 kPa, respectively, of SHI2.7/210=20-150. Also, preferably, the multimodal polyethylene has a MFR5 of 0.1-2.0 g/10 min and a melt strength at 190° C. of at least 4 g. The multimodal polymer composition is particularly useful as a material for slotted core elements of fiber optical cables of the slotted core type.
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