Claims
- 1. A process for the preparation of a copolymer of ethylene and an alpha-olefin having from 3 to 20 carbon atoms characterised in having(a) a flow activation energy (Ea) in the range 50≦Ea≦200 kJ/mol, (b) a degree of long chain branching (LCB/1000C) as measured by GPC/solution viscometry in the range 0.25≦LCB≦0.03 Ea=1.5 and (c) a breadth of molecular weight distribution Mw/Mn greater than 2.5, said process comprising polymerising in a gas phase ethylene and an alpha-olefin having from 3 to 20 carbon atoms in the presence of an unprepolymerized supported catalyst comprising a metallocene complex having the general formula: wherein Cp1, Cp2 are independently a substituted or unsubstituted indenyl or hydrogenated indenyl group, Y is a univalent anionic ligand, M is zirconium, titanium or hafnium, and Z is a bridging group comprising an alkylene group having 1 and 20 carbon atoms or a dialkyl silyl- or germanyl-group, or alkyl phophine or amine radical.
- 2. A process according to claim 1 wherein M is zirconium.
- 3. A process according to claim 1 wherein the metallocene complex has the formula:
- 4. A process according to claim 1 wherein the metallocene complex is used in the presence of a co-catalyst.
- 5. A process according to claim 4 wherein the co-catalyst is an organo aluminium compound.
- 6. A process according to claim 5 wherein the organo aluminium compound is methyl aluminoxane.
- 7. A process according to claim 1, wherein the metallocene complex is supported on silica, alumina or magnesium dichloride.
- 8. A process according to claim 1 performed in the gas phase.
- 9. A process according to in claim 1 wherein Cp1 and Cp2 are independently unsubstituted indenyl or hydrogenated indenyl groups.
Priority Claims (2)
Number |
Date |
Country |
Kind |
9406895 |
Apr 1994 |
GB |
|
9417365 |
Aug 1994 |
GB |
|
Parent Case Info
This application is a continuation, of application Ser. No. 08/669,800, filed Jun. 27, 1996 now abandoned, which is a continuation, of application Ser. No. 08/410,986, filed Mar. 27, 1995, now abandoned.
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5218071 |
Tsutsui et al. |
Jun 1993 |
|
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|
5296565 |
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Mar 1994 |
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Number |
Date |
Country |
0452920 |
Oct 1991 |
EP |
9308221 |
Apr 1993 |
WO |
Non-Patent Literature Citations (1)
Entry |
Kaminsky, “Metallocene Catalysts” SP'92-Polyethylene World Congress, Dec. 1992. |
Continuations (2)
|
Number |
Date |
Country |
Parent |
08/669800 |
Jun 1996 |
US |
Child |
08/904437 |
|
US |
Parent |
08/410986 |
Mar 1995 |
US |
Child |
08/669800 |
|
US |