Prepolymer for olefin polymerisation combining several solid catalyst components

摘要

Prepn. of prepolymer comprises prepn. of polymer A by polymerisation of at least one olefin in suspension or gas phase in presence of solid catalyst compsn. (A); mixing with organoaluminium deriv. and then solid catalyst compsn. (B) to give an aggregate; and then prepolymerisation AB of at least one olefin in gas phase in presence of aggregate. Pref. the organoaluminium cpd. is trialkylaluminium. The catalytic solid compsn. (A) and/or (B) contain titanium cpd. capable of polymerising olefins. The molar ratio organoaluminium cpd.:transition metal in prepolymer A = 1-1000. Prepolymerisation is carried out by controlling the flow of the monomer.