Solid catalyst component for ethylene polymerization and process for its preparation, catalyst for ethylene homopolymerization or ethylene copolymerization with ALFA-olefins, and process for the preparation of ethylene polymers

摘要

Solid catalyst component for the polymerization of ethylene comprising the product of the reaction between: 1) the product obtained by reacting: 1A) a halide or halogen alcoholate or alcoholate of titanium, vanadium or zirconium; 1B) a small quantity of water, and optionally 1C) a compound or composition capable of substituting, in compound 1A, one or more alkoxy groups with a halogen atom; and 2) a complex having general formula: MgX2.nAlRX2.pAlX3 where X is chlorine or bromine; R is a hydrocarbon radical containing from 1 to 20 carbon atoms; n is a number from 1 to 4; p is a number from 0 to 1, and n+p from 1 to 4; said catalyst component being in the form of particles having a diameter lower than or equal to 20 micrometers, and an average diameter lower than or equal to 10 micrometers.