Prepolymer for the polymerization of olefins combining a number of solid catalytic components

Process for the preparation of a substantially homogeneous prepolymer consisting essentially of:

• a) preparation of a prepolymer A active for the polymerization of olefins by suspension or gas-phase prepolymerization of at least one olefin in the presence of a solid catalytic component A having a first morphology, then,
• b) addition of a liquid organic aluminum compound cocatalyst and then of a solid catalytic component B having a second morphology on the prepolymer A, to obtain an aggregate, then,
• c) gas-phase prepolymerization AB of at least one olefin in the presence of the aggregate obtained in b) whereby a substantially homogeneous prepolymer is obtained, the homogeneous prepolymer being an active polymer obtained by polymerization of the at least one olefin in the presence of the catalytic components, said active polymer representing not more than ten percent of the mass of the total polymer synthesizable by Polymerization of the at least one olefin in the presence of the homogeneous Prepolymer.

A homogeneous prepolymer AB consisting of a solid catalyst component A active for the polymerization of olefins and a different solid catalytic component B each of which different components contribute different properties to prepolymer AB and the prepolymer AB is more homogeneous than if a simple mixture of different solid catalytic components A and B are used in a prepolymerization, the prepolymer AB being an active polymer obtained by polymerization of at least one olefin in the presence of a catalytic component, said active Polymer representing not more than ten percent of the mass of the total polymer synthesizable by polymerization of the at least one olefin in the presence of the prepolymer AB.