Process for the preparation of supports based on magnesium chloride for the preparation of catalysts for the polymerization of alpha-olefins and the supports obtained

摘要

The present invention relates to catalyst supports for the polymerization and co-polymerization of alpha-olefins, especially ethylene and propylene, consisting essentially of magnesium chloride, characterized in that these supports occur in the form of spheroidal particles with a mean particle size by mass comprised between 10 and 100 microns and having a narrow particle size distribution, which can be controlled, such that the ratio of the mean diameter by mass to the mean diameter by number of the particles is less than or equal to 3.0, and the process for the preparation of the said supports.