PROCESS

摘要

A process for the preparation of a propylene homopolymer in a multistage polymerisation process in the presence of a single site catalyst, said process comprising: (I) in a slurry polymerisation step, polymerising propylene in the presence of said single site catalyst; and subsequently (II) in a gas polymerisation step polymerising propylene in the presence of catalyst and polymer from step (I) so as to form a propylene homopolymer; wherein said catalyst comprises (i) a metallocene complex of a Group 4 metal, said metallocene comprising at least two cyclopentadienyl type ligands; (ii) a boron based cocatalyst; and (iii) an aluminoxane cocatalyst; said catalyst being in solid form, preferably in solid particulate form, and being free from an external carrier.