Method for producing polymer of ethylene
AssigneePhillips Petroleum Company
InventorsHelmut G. Alt, Syriac J. Palackal, M. Bruce Welch, David C. Rohlfing, Jay Janzen
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Abstract
A process for preparing a polymer of ethylene having a flow activation energy higher than that of a substantially linear ethylene polymer of the same molecular weight involving using bridged sandwich-bonded fluorenyl-containing metallocenes and the polymers resulting therefrom.
Claims25
A process for preparing a polymer of ethylene having a flow activation energy of at least about 25 kJ/mol, comprising contacting ethylene in a liquid diluent with a catalyst system comprising:
- (1) a catalyst comprising 1-(9-fluorenyl)-2-(indenyl) ethane zirconium dichloride, and
- (2) a cocatalyst for said metallocene.
A process for preparing a polymer of ethylene having a flow activation energy of at least about 25 kJ/mol comprising contacting ethylene in the presence of an acyclic olefinic comonomer having 4 to 12 carbon atoms in a liquid diluent wherein the molar ratio of the comonomer employed to the ethylene employed is in the range of from about 0.025/1 to about 0.5/1 and the resulting copolymer has a density in the range of 0.88 to about 0.96 g/cc using a catalyst system comprising:
- (1) a fluorenyl-containing metallocene selected from compounds of the formula (Z)--R'--(Z')MeQ.sub.2 wherein R' is selected from --CH.sub.2 CH.sub.2 --, --CH.sub.2 --, and dimethylsilylene, and each Q is a halide, Z is a substituted or unsubstituted fluorenyl radical, Z' is a substituted or unsubstituted fluorenyl radical, a substituted or unsubstituted indenyl radical, a substituted or unsubstituted cyclopentadienyl radical, a tetrahydroindenyl radical, or an octahydrofluorenyl radical;
- Me is selected from Zr and Hf, and
- (2) a cocatalyst for said metallocene.
Dependencies are inferred from the claim text.