Metallocenes, polymerization catalyst systems, their preparation, and use
View Patent ↗Metallocene having two cyclic dienyl groups connected by a single carbon having an aryl substituent and a terminally unsaturated hydrocarbyl substituent, olefin polymerization catalyst systems prepared therefrom, and the use of such catalyst systems are disclosed.
1. A metallocene represented by the formula R(Z)(Z)MQ k , wherein:
one Z is a substituted fluorenyl ligand and the other Z is an unsubstituted cyclopentadienyl ligand;
R is a structural bridge linking the Z's and having the formula >C(but-3-enyl)(phenyl);
M is Zr or Hf;
each Q is a halogen; and
k is 2.
2. A metallocene according to claim 1 having the formula 1-(cyclopentadienyl)-1-(substituted fluorenyl)-1-(but-3-enyl)-1-(phenyl) methane zirconium dichloride.
3. A composition suitable for use as a catalyst system for the polymerization of olefins comprising the metallocene as set forth in claim 1 and a suitable cocatalyst.
4. A composition according to claim 3 wherein the cocatalyst comprises an organoaluminoxane.
5. A composition according to claim 3 wherein the cocatalyst comprises methylaluminoxane.
6. A composition according to claim 3 wherein the metallocene has the formula 1-(cyclopentadienyl)-1-(substituted fluorenyl)-1-(but-3-enyl)-1-(phenyl) methane zirconium dichioride.
7. A composition according to claim 3 wherein the cocatalyst is produced by reacting a carrier with an organoaluminum compound and then with water to yield a solid.
8. A composition according to claim 3 produced by combining the metallocene with a solution of an organoaluminoxane and conducting prepolymerization to produce a prepolymerized solid, and then washing the solid to remove soluble components, and recovering the solid as the catalyst system.
9. A composition according to claim 8 wherein the prepolymerization is conducted in the presence of particulate silica.