PROCESS FOR PRODUCING POLYPROPYLENE

摘要

Propylene is polymerised in the presence of a polymerisation catalyst comprising a solid catalyst component, an organoaluminium compound and an external electron donor, the process comprising the steps of (i) contacting propylene and hydrogen with the polymerisation catalyst in polymerisation conditions in a polymerisation reactor to produce a polymer of propylene; (ii) recovering the polymer of propylene from the polymerisation reactor; wherein the polymer of propylene has MFR of from more than 100 to 10000g/10 min. The solid catalyst component comprises titanium, magnesium, halogen and an internal electron donor, characterised in that the internal electron donor is a compound according to formula (I) with R1 and R2 being the same or different and being a linear or branched C1-C12-alkyl group, and with R being H or a linear, branched or cyclic C1 to C12-alkyl, whereby it is preferred that R is not H. The external electron donor is a silane compound having the formula Si(OR11)nR10 4-n, wherein each R10 is independently a linear or branched C1-C4 alkyl, preferably methyl or ethyl; and each R10 is independently a linear or branched alkyl group having from 1 to 24 and optionally containing an atom of group 15 of periodic table of elements or comprises a cyclic group having from 6 to 12 carbon atoms.