Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2001-10-12
2003-05-13
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S170000, C526S169000, C526S169200, C526S348000, C526S348300, C526S348500, C526S348200, C526S348600, C526S351000, C526S352000, C502S103000, C502S117000
Reexamination Certificate
active
06562921
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to catalyst precursor compounds which in combination with an activator forms a catalyst composition that is useful for the polymerization of olefin(s). The catalyst precursor compound comprises a metal atom and two &pgr;-bonded aromatic ring systems, where the aromatic ring systems are linked together by a bridging group comprising a ring, such that the aromatic ring systems are linked to adjacent members of the ring, either directly or through another group, in cis fashion. The present invention also relates to a method of preparing such catalyst precursor compounds, catalyst compositions comprising these catalyst precursor compounds, and polymerization processes utilizing same.
BACKGROUND OF THE INVENTION
A variety of catalyst compositions containing single site catalyst precursors have been shown to be highly useful in the preparation of polyolefins, producing relatively homogeneous copolymers at good polymerization rates. In contrast to traditional Ziegler-Natta catalyst compositions, single site catalyst compositions such as metallocene catalysts comprise catalytic compounds in which each catalyst composition molecule contains one or only a few polymerization sites, thereby allowing one to tailor the properties of the finished polymer.
There is a continuous need in the art to provide new and varied single site catalysts that can produce new and/or tailored polyolefins. There are several possible ways of modifiying the structure of already known single site catalyst precursor compounds to arrive at new catalysts and, thus new polymer products. One of these possible modifications involves the moiety which bridges two cyclopentadienyl or related ligands of a metallocene catalyst precursor compound. Compounds having cyclic bridging moieties are described in the literature. However, the stereochemistry of the bonds between the cyclopentadienyl ligands and the cyclic bridging group in the catalyst precursor compound and its utilization for influencing the properties of the corresponding catalyst system and the polymer made thereby have not received much attention so far.
B. Rieger, J. Organometallic Chem. 1992, 428, C33-36, fully incorporated herein by reference, describes the preparation of trans-1,2-cyclohexylenebis (1-indenyl)zirconium dichloride and the use thereof as catalyst for the polymerization of propylene. Furthermore, A. Steinhorst et al, J. Organometallic Chem. 1997, 542, 191-204, fully incorporated herein by reference, report on the preparation and use as catalyst precursors for the polymerization of propylene, respectively, of a series of trans-1,2-cycloalkylene-bridged bis(indenyl or tetrahydroindenyl)MCl
2
species (M=Ti, Zr, Hf) wherein the cycloalkylene bridge has 5 to 8 members.
According to the present invention, the combination of activator (cocatalyst) and single site catalyst precursor compounds comprising two aromatic ring systems &pgr;-bonded to a metal atom and linked in cis fashion to adjacent (vicinal) ring members of a cyclic bridging group are very effective for the polymerization of olefins. Moreover, it has been found that this particular way of bridging the aromatic ring systems can be used to constrain the geometry around the metal atom, thereby influencing the structure of the polymer chains obtainable from the corresponding catalyst composition.
SUMMARY OF THE INVENTION
The present invention provides a catalyst precursor compound including a metal selected from Groups 3 to 12 and the lanthanide and actinide series of the Periodic Table of Elements and two &pgr;-bonded aromatic ring systems. The aromatic ring systems are linked by a bridging group which comprises a 3 to 12-membered ring, where the aromatic ring systems are linked to adjacent members of the ring, either directly or through another group, in cis fashion. The invention also provides methods for preparing the catalyst precursor compound, catalyst compositions incorporating the catalyst precursor compound and polymerization processes utilizing same.
DETAILED DESCRIPTION
A new catalyst precursor compound has been discovered which includes a metal selected from Groups 3 to 12 and the lanthanide and actinide series of the Periodic Table of Elements and two &pgr;-bonded aromatic ring systems. The aromatic ring systems are linked by a bridging group which comprises a 3- to 12-membered ring, where the aromatic ring systems are linked to adjacent members of the bridging ring, either directly or through another group, in cis fashion.
The metal atom is selected from Groups 3 through 12 and the lanthanide or actinide series of the Periodic Table of Elements. Preferably the metal atom is selected from Groups 3 to 10 and the lanthanide series, more preferably from Groups 4, 5 and 6, more preferably from Group 4 and most preferably the metal atom is Zr or Hf.
The aromatic ring systems of the catalyst precursor compound are bonded to the metal atom. The aromatic ring systems (which can be the same or different) are typically composed of atoms selected from Groups 13 to 16 of the Periodic Table of Elements. Preferably the atoms are selected from carbon, nitrogen, oxygen, silicon, sulfur, phosphorus, germanium, boron, aluminum and combinations thereof. Most preferably, the aromatic rings or ring systems are composed of or comprised carbon atoms such as, but not limited to, unsubstituted or substituted, cyclopentadienyl and cyclopentadienyl-type ligands (“cyclopentadienyl-type” meaning a ligand comprising a cyclopentadienyl or related structure, e.g., a structure wherein one or more carbon atoms of a cyclopentadienyl ligand are replaced by one or more hetereoatoms such as, e.g., N, O and S). Non-limiting examples thereof include unsubstituted and substituted cyclopentadienyl, indenyl, benzindenyl, fluorenyl, azulenyl, pyrrolyl, pyrazolyl, carbazolyl and borabenzene ligands and the like, including hydrogenated versions thereof, for example, tetrahydroindenyl, tetrahydrofluorenyl and octahydrofluorenyl ligands.
Independently, each of the two aromatic rings or ring systems may optionally be substituted with one or more substituent groups. Non-limiting examples of substituent groups are linear, branched and cyclic alkyl, alkenyl and alkynyl radicals, aryl, arylalkyl and alkylaryl radicals, acyl radicals, aroyl radicals, alkoxy radicals, aryloxy radicals, alkylthio radicals, dialkylamino radicals, alkoxycarbonyl radicals, aryloxycarbonyl radicals, carbamoyl radicals, alkyl- and dialkylcarbamoyl radicals, acyloxy radicals, acylamino radicals, aroylamino radicals and combinations thereof. In a preferred embodiment the substituent groups, if any, have up to 50 non-hydrogen atoms, e.g., from 1 to 30 carbon atoms, more preferably from 1 to 20 carbon atoms, most preferably from 1 to 12 carbon atoms. Moreover these substituent groups may also be halogenated, e.g., fluorinated and/or chlorinated. Illustrative, non-limiting examples of substituents include methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, benzyl, phenyl, tolyl and xylyl groups and the like, including all their isomers, for example tertiary butyl, isopropyl, and the like. Further non-limiting examples of other possible substituents include hydrocarbyl substituted organometalloid radicals such as, e.g., trimethylsilyl, trimethylgermyl, methyldiethylsilyl and the like; halocarbyl-substituted organometalloid radicals including tris(trifluoromethyl)silyl, methyl-bis(difluoromethyl)silyl, bromomethyl-dimethylgermyl and the like; and disubstituted boryl radicals including dimethylboryl and the like; disubstituted pnictogen radicals including dimethylamino, dimethylphosphino, diphenylamino, methylphenylphosphino and the like; and chalcogen radicals including methoxy, ethoxy, propoxy, phenoxy, methylthio, ethylthio and the like. In general, the non-hydrogen atoms of the substituents are selected from carbon, silicon, boron, aluminum, nitrogen, phosphorus, oxygen, tin, sulfur, germanium and the halogens. Also, at least two substituent groups, preferably two adjacent substitu
Froese Robert D.
Peterson Thomas Henry
Wenzel Timothy T.
Faulkner Kevin M.
Jones Lisa Kimes
Lee Rip A.
Univation Technologies LLC
Wu David W.
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