| 摘要 |
The present invention relates to catalysts for the polymerization and copolymerization of ethylene, characterized in that they comprise a support based on magnesium chloride and possibly on aluminium chloride, of spheroidal shape, having a mean diameter by mass comprised between 10 and 100 microns and with a narrow 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, on which support there has been precipitated a derivative of a transition metal of groups IV, V and VI of the Periodic Table of Elements, and a polymerization process utilizing the said catalysts. |
