| 摘要 |
<p>A process for producing a multimodal polyethylene in at least two reactors connected in series is disclosed, in which 20-80wt% of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80wt% of a low molecular weight (LMW) polymer is made in suspension in a second reactor, one polymer being made in the presence of the other in either order,
wherein the ratio of the average activity in the LMW reactor to the average activity in the HMW reactor is from 0.25 and 1.5, where average activity in each reactor is defined as the amount of polyethylene produced in the reactor (kgPE) / [ethylene concentration in the reactor (mol%) x residence time in the reactor (hours) x weight of catalyst in the reactor (g)], residence time being defined as the mass of the polymer in the reactor (kg)/the production rate of polymer (kg/hr), and the volumes of the two reactors differ by less than 10%.</p> |
