| abstract |
Supported catalysts for the high-yield polymerization of olefins to polymers which occur in spheroidal form are disclosed. The catalysts are prepared from starting components which comprise (a) organometallic compounds of metals belonging to Groups II or III of the Mendelyeev Periodic Table and (b) a product obtained by reacting a halogenated Ti compound with a Mg hydrate chloride in the form of spheroidal particles having controlled dimensions comprised between 10 and 70 microns. |