| 摘要 |
<p>A polyethylene resin having excellent moldability and long-term properties and suitable for pipes and pipe joints, characterized by having a density of 0.915 to 0.955 g.cm-3, a melt flow rate of not more than 0.20 dg.min-1 as measured at 190 °C under a load of 2.16 kgf, a melt flow rate of 17.0 to 70.0 dg.min-1 as measured at 190 °C under a load of 21.6 kgf, and, when the dynamic melt viscosity (θ* in Pa.s) as measured at 190 °C with a rheometer using a parallel plate under the conditions of a plate-to-plate distance of 1.5 mm, a strain of 10 to 15 % and a frequency (φ) range of from 100 to 0.01 rad.s-1 is satisfactorily approximated by the equation [1], a zero shear viscosity (θ¿0?) of 200,000 to 2,000,000 Pa.s, a specific time constant (τ0) of 50 to 500 sec, and a (τ0/θ0) value of 1.0 x 10?-4¿ to 4.0 x 10-4 Pa-1. Formula [I] wherein n is a parameter.</p> |
