| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polyethylene pipe good in smoothness of the molded surface, and excellent in a balance of rigidity and long-term creeping property. <P>SOLUTION: An ethylenic polymer is used in which the density is 920 to 970 kg/cm<SP POS="POST">3</SP>; MFR is 0.005 to 1 g/10-min; in a molecular weight measurement using gel permeation chromatography, there is two peaks exhibited; the ratio (Mw/Mn) of the weight-average molecular weight (Mw) and the number-average molecular weight (Mn) is in the range of 2.0 to 7.0; the proportion of components having Mn of ≥100,000 in the molecular weight fractionation is <40% with respect to the whole polymer; and ≥0.15 branch of long-chain branches per 1,000 carbon atoms in the main chain is present in fractions having Mn of ≥100,000 in molecular weight fractionation. <P>COPYRIGHT: (C)2012,JPO&INPIT |
