| 摘要 |
<p>A process for the production of random or impact copolymers of propylene exhibiting bimodality comprising the following steps: (a) contacting propylene and one or more alpha-olefin(s) with a catalyst system comprising (i) a catalyst precursor, which includes titanium, magnesium and an electron donor; (ii) a hydrocarbylaluminum cocatalyst; and (iii) a selectivity control agent in one or more reactors, under polymerization conditions; and (b) introducing into the reactor(s), or after polymerization into the propylene copolymer, one or more saturated alicyclic hydrocarbon(s), said hydrocarbon(s) being liquid at process temperature, non-polar, essentially amorphous, and containing less than about 15 percent by weight paraffin wax, in an amount of about 0.1 to about 20 parts by weight of hydrocarbon(s) per 100 parts by weight of propylene copolymer.</p> |
