Mixed catalyst system
First Claim
1. A composition comprising an unsupported metallocene catalyst and a supported metallocene catalyst wherein both the unsupported and supported metallocene catalyst satisfy at least one of the following structural formulae (II) or (III):
- ##STR7## wherein;
M is a Hf or Zr metal;
L is a substituted or unsubstituted, π
-bonded ligand coordinated to M;
each Q is independently selected from the group consisting of --O--,--NR3 --, --CR32 --and --S--;
Y is C;
Z is selected from the group consisting of --OR3, --NR32, --CR33, --SR3, --SiR33, --PR32, and --H, with the proviso that when Q is --NR3 -- then Z is selected from the group consisting of --OR3, --NR32, --SR3, --SiR33, --PR32, and --H;
n is 1 or 2;
A is a univalent anionic group when n is 2 or A is a divalent anionic group when n is 1; and
each R3 is independently a group containing carbon, silicon, nitrogen, oxygen, and/or phosphorus and one or more R3 groups may be attached to the L substituent;
T is a bridging group selected from the group consisting of alkylene groups containing from 1 to 10 carbon atoms optionally substituted with carbon or heteroatoms, arylene groups containing from 1 to 10 carbon atoms optionally substituted with carbon or heteroatoms, germanium, silicone and alkyl phosphine; and
m is 1 to 7.
1 Assignment
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Accused Products
Abstract
It has been found that the use of at least one unsupported metallocene polymerization catalyst with at least one supported metallocene polymerization catalyst in the polymerization of olefins allows for better control of the polymerization, especially gas phase polymerization. Such a system takes advantage of the high activity of the unsupported catalyst and the stability of a supported catalyst. Additionally, the relative timing of the addition of the supported and unsupported catalysts to a reaction system can be used to control a continuous polymerization reaction by stabilizing the reactor bed with the supported catalyst prior to addition of the unsupported catalyst.
106 Citations
4 Claims
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1. A composition comprising an unsupported metallocene catalyst and a supported metallocene catalyst wherein both the unsupported and supported metallocene catalyst satisfy at least one of the following structural formulae (II) or (III):
- ##STR7## wherein;
M is a Hf or Zr metal;L is a substituted or unsubstituted, π
-bonded ligand coordinated to M;each Q is independently selected from the group consisting of --O--,--NR3 --, --CR32 --and --S--; Y is C; Z is selected from the group consisting of --OR3, --NR32, --CR33, --SR3, --SiR33, --PR32, and --H, with the proviso that when Q is --NR3 -- then Z is selected from the group consisting of --OR3, --NR32, --SR3, --SiR33, --PR32, and --H; n is 1 or 2; A is a univalent anionic group when n is 2 or A is a divalent anionic group when n is 1; and each R3 is independently a group containing carbon, silicon, nitrogen, oxygen, and/or phosphorus and one or more R3 groups may be attached to the L substituent; T is a bridging group selected from the group consisting of alkylene groups containing from 1 to 10 carbon atoms optionally substituted with carbon or heteroatoms, arylene groups containing from 1 to 10 carbon atoms optionally substituted with carbon or heteroatoms, germanium, silicone and alkyl phosphine; and m is 1 to 7. - View Dependent Claims (2, 3, 4)
- ##STR7## wherein;
Specification