| 摘要 |
<p>The present invention relates to catalysts which can be used for the polymerisation and copolymerisation of propylene with other alpha-olefins, characterised in that they comprise a support containing essentially magnesium chloride and possibly a chlorinated aluminium derivative, and occurring in the form of spheroidal particles having a mean diameter by mass comprised between 10 and 100 microns and a particle size distribution such that the ratio of the mean diameter by mass to the mean diameter by number is less than or equal to 3, which support has been treated by an electron donor compound chosen from among the aromatic ethers and aromatic acid esters and which when impregnated with titanium tetrachloride comprises 0.5 to 3% of atoms of titanium per atom of magnesium, and process for utilizing the said catalyst.</p> |
