| abstract |
This invention relates to a syndiospecific metallocene of a substituted iPr[(cyclopentadienyl)(fluorenyl)]zirconium dichloride containing long-chain terminal alkene, for example octenyl groups, on fluorene at C2/C7. The metallocene compound useful as a catalyst in the present invention is described by the general formula: R''(C5H4)(C4H4-mR'mC5C4H4-nR'n)MeQp wherein (C5H4) is a cyclopentadienyl ring and (C4H4-mR'mC5C4H4-nR'n) is a fluorenyl radical; R' is a long chain alkene substituent having 5-20 carbon atoms on the fluorene ligand at C2 or C7, each R' may be the same or different; R'' is a structural bridge between the (C5H4) and (C4H4-mR'mC5C4H4-nR'n) rings to impart stereorigidity; Q is a hydrocarbon radical or a halogen; Me is a Group IIIB, IVB, VB, or VIB metal; m=0 or 1; n=1; and p is the valence of Me minus 2. Polymerizations with metallocene/MAO solutions stored at room temperature under nitrogen for several days resulted in gradual increases in polymer yields when using the metallocene of the present invention and a decrease in polymer yield when using metallocne of the prior art. |