摘要 |
<p>A catalyst which exhibits superior control of product particle size in the insertion polymerization of alpha-olefins is described as transition metal compounds which associate with non-coordinating alumoxane anions which are dispersed throughout the interior of a silica support in the form of particles which are less than or equal to about 50 Å (5 nanometers) in diameter. This catalyst is capable of gas phase (e.g. heterogeneous) polymerization of propylene into product granules with a high degree of control over granule particle size distribution and bulk density.</p> |