| 摘要 |
<p>A linear polyethylene which is produced by the use of a Ziegler-Natta catalyst and satisfies the requirements described in the following (1) to (6): 0.20 to 0.50 g/10 minutes in terms of a melt flow rate (190 °C, load: 5.00 kg), 0.948 to 0.952 g/cm3 in terms of a density, 65 to 130 in terms of a flow ratio (FR), 1.90 x 10?-8dyn/cm2¿ or less in terms of a relaxation parameter H as determined by the stress relaxation measurement, 39 to 45 wt % in terms of the proportion (WH) of the amount of high molecular weight components integrated over all the elution temperature divisions to the total amount of the polyethylene eluted, as determined by the cross fractionation method (TREF-SEC), and 96.5 °C or lower in terms of a peak temperature (TH) of the elution curve for the high molecular weight component of the polyethylene and 99.2 °C or lower in terms of peak temperature (TL) of the elution curve for the low molecular weight component thereof, both being determined by the cross fractionation method; and a pipe and a joint using the polyethylene.</p> |
