abstract |
Ethylene (co)polymers excellent in moldability, mechanical characteristics and so on and suitable for various moldings, particularly pipes. For example, ethylene homopolymers or ethylene/C4-C20 α-olefin copolymers, wherein the number of methyl branches is less than 0.1 per 1000 carbon atoms as determined by 13C-NMR and the Mw/Mn ratio is 1.8 or above but below 4.5 as determined by GPC; and ethylene homopolymers or ethylene/C¿3?-C20 α-olefin copolymers, wherein the melt tension (MT) and the swelling ratio (SR) satisfy the relationship: log(MT) > 12.9 - 7.15 x SR, and the intrinsic viscosity ([θ]) and the melt flow rate (MFR) satisfy the relationship: [θ] > 1.85 x MFR?-0.192¿ in the case of MFR < 1, or [θ] > 1.85 x MFR-0.213 in the case of MFR ≥ 1. |