| 摘要 |
<p>The invention relates to a process for the production of an olefin polymer having a desirable molecular weight distribution, comprising: a) feeding to a polymerization equipment: a1) a polymerization material comprising at least one olefin; a2) a catalyst system having at least one catalyst component, which is hydrogen sensitive and under zero or constant hydrogen concentration gives olefin polymer with a narrower molecular weight distribution than the polymer having the desirable broad molecular weight distribution; and a3) hydrogen as a molecular weight regulating agent; b) contacting reactants a1), a2) and a3) during a residence time in the polymerization equipment and under polymerization cnditions to give a polymerization mixture; and c) recovering from said polymerization mixture said polymerization material in the form of the olefin polymer having a desirable broad molecular weight distribution. Said process is characterized in that during said residence time of the contact step b), the partial pressure of hydrogen is varied or allowed to vary continuously or by a repeated cycle.</p> |
