PROCESS FOR PRODUCING A ZIEGLER NATTA PROCATALYST FOR ETHYLENE POLYMERISATION

摘要

Process for the preparation of a particulate Group 2 metal/transition metal polymerization catalyst component for ethylene polymerization comprising a special bi-(oxygen containing ring) compound as internal donor, and to the use of such a catalyst component for preparing a catalyst used in the polymerization of ethylene.

主权项

1. Process for preparing an ethylene polymerization catalyst component in the form of solid particles comprising the steps of
a)
a1) providing a solution of an alkoxy compound (Ax) being the reaction product of a compound of a Group 2 metal with a monohydric alcohol (A) in an organic liquid reaction medium; ora2) providing a solution of an alkoxy compound (Ax) being the reaction product of a Group 2 metal compound and an alcohol mixture of a monohydric alcohol (A) and an alcohol (B) comprising in addition to the hydroxyl moiety at least one further oxygen bearing group being different to a hydroxyl moiety, optionally in an organic liquid reaction medium; ora3) providing a solution of an alkoxy compound mixture of at least a first alkoxy compound (Ax) being the reaction product of a Group 2 metal compound and a monohydric alcohol (A), optionally in an organic liquid reaction medium and at least a second alkoxy compound (Bx) being the reaction product of a Group 2 metal compound and an alcohol (B) comprising in addition to the hydroxyl moiety at least one further oxygen bearing group being different to a hydroxyl moiety, optionally in an organic liquid reaction medium; and b) adding said solution to at least one compound of a transition metal (CT) and c) preparing the catalyst component in the form of solid particles, d) optionally performing one or more washing steps and e) recovering the catalyst component in the form of solid particles, wherein a compound of the formula (I)wherein in the formula (I)
X is C or Si,R1 can be the same or different and can be hydrogen, a linear or branched C1 to C8-alkyl group, or a C3-C8-alkylene group,and R2 to R5 are the same or different and can be hydrogen, a linear or branched C1 to C8-alkyl, or a C3-C8-alkylene group,whereby two or more of R1 to R5 can form a ring,n is the same for both oxygen-containing rings and can be 0, 1 or 2, preferably 1 or 2,whereby the two oxygen-containing rings can be individually saturated or unsaturated, or an isomer mixture therefrom is added as internal donor at any step prior to step e).