Organic compounds -- part of the class 532-570 series – Organic compounds – Heavy metal containing
Reexamination Certificate
1999-12-20
2002-03-12
Nazario-Gonzalez, Porfirio (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heavy metal containing
C556S012000, C556S028000, C502S103000, C502S117000, C502S120000, C526S160000, C526S943000, C526S351000
Reexamination Certificate
active
06355819
ABSTRACT:
The present invention relates to novel metallocene compounds, their intermediates and their preparation. Specifically the invention relates to transition metal metallocenes with heteroatom 1- or 3-substituted indenyl and indenyl derivative ligands and a method for their preparation. The invention also relates to 1- or 3-substituted indene compounds as intermediates for the metallocene compounds and their preparation. Further, the invention relates to the use of said metallocenes in catalyst systems for the homo- and copolymerization of ethylenically unsaturated monomers, preferably olefins, more specifically propylene, ethylene and higher alphaolefins, especially in the presence of a cocatalyst, such as methylaluminoxane (MAO).
Chiral C
2
symmetric bis(indenyl) ansa-metallocenes are well-known catalyst components for stereoselective polymerization of alpha-olefins. The performance characteristics of these systems are different, the variations being induced by size and position of the substituents. E.g., dimethylsilylene bridged 2,2′-dimethyl-4,4′-diaryl substituted bis(indenyl) zirconocenes developed by Brintzinger and coworkers (Organometallics 1994, 13, 964) and Spaleck et al. (Organometallics 1994, 13, 954), produce isotactic polypropylenes with catalyst activities and polymer properties comparable to those obtained with heterogeneous Ziegler-Natta catalysts.
The area of electronically altered bis(indenyl) metallocenes has remained relatively unexplored. Previously, it has been reported that halogen or alkoxy substitution in the six-membered rings of indenes reduces the activity of the catalyst system and the molecular weight of the produced polymer (Consiglio et al, Organometallics 1990, 9, 3098; Collins et al., Organometallics 1992, 11, 2115). Bis(indenyl) zirconocenes with 2-amino functionalized ligands have been reported recently by several groups (Luttikhedde et al., Organometallics 1996, 15, 3092; Plenio and Burth, J. Organomet. Chem. 1996, 519, 269; Brintzinger et al., J. Organomet. Chem. 1996, 520, 63). The bridged complexes show somewhat lower catalytic activities compared with their unsubstituted bis(indenyl) zirconocene analogues.
It has now been found however that metallocenes in which a bulky electron withdrawing or donating group is attached to the five membered ring of an indenyl or indenyloid (ie. indenyl analog) ligand have particularly interesting properties, in particular in terms of catalytic activity when used with an alumoxane cocatalyst in propylene and ethylene polymerization.
Thus viewed from one aspect the invention provides a metallocene having a sandwich bonding having ligand comprising a sandwich bonding moiety, having an unsaturated 5-membered ring or a 6-membered ring fused to an unsaturated 5-membered ring, which is covalently substituted by a pendant group containing at least two atoms other than hydrogen and attached via an atom other than a methylene carbon, preferably attached via an oxygen, sulphur, nitrogen or phosphorus atom or via a carbon—carbon multiply bonded carbon atom, eg. a group as described below or in FI 970349 the contents of which are incorporated herein by reference. The sandwich bonded metal in the metallocene is preferably a Group 4 transition metal, particularly Zr, Hf or Ti, most preferably Zr. Other catalytically effective metals however may be used.
By pendant it is meant that the bulky substituent is not attached to a second group which sandwich bonds the metal of the metallocene.
The requirement that the group contains at least two non-hydrogen atoms simply specifies a minimum bulk for the required bulky substituent. Thus halogens and unsubstituted hydroxyl and amine groups are excluded for example. Preferably the substituent contains up to 32 non-hydrogen atoms. The requirement that the group be attached other than via a methylene carbon indicates that the substituent will interact with the electron system of the five membered ring. Suitable means of attachment include oxygen, sulphur, nitrogen and phosphorus atoms and II-bonded carbon atoms. Oxygen attachment is preferred. The attachment atom preferably carries at least one bulky substituent, eg. a C
1-20
hydrocarbyl group, or more preferably a silyl group or a germyl group, with the silicon or germanium atoms themselves optionally being substituted by C
1-20
hydrocarbyl or hydrocarbyloxy groups.
The fused 5 and 6-membered rings in the sandwich bonding ligand may be homocyclic (carbocyclic) or heterocyclic, for example containing up to 4 ring heteroatoms selected from O, N and S. The four atom bridge portion of the six membered ring may be unsaturated or saturated. Both the 5 and 6-membered ring may carry other homo- or heterocyclic fused rings. The bulky substituent may be at the 1, 2 or 3 position of the 5-membered ring, eg. the 1- or 3-positions. Particularly preferably the ligand contains two such fused 5/6 member ring systems linked via a bridging atom or group (eg. an ethylene bis indenyl ligand).
In the case where the bulky substituent is a silyloxy or germyloxy group, it is possible for this to be on the 6-membered rather than the 5-membered ring. This represents a further aspect of the invention. Viewed from this aspect the invention provides a metallocene catalyst precursor having a sandwich bonding ligand which comprises a sandwich bonding moiety having an unsaturated 5-membered ring or having a 6-membered ring fused to an unsaturated 5-membered ring, said moiety being substituted on the fused ring structure by a silyloxy or germyloxy group, eg. at the 1, 3, 4, 5, 6 or 7 positions. Germanium atom is further substituted by a C
1-20
hydrocarbyl or hydrocarbyloxy group.
These ligands themselves are novel and form a further aspect of the invention. Viewed from this aspect the invention provides a sandwich bonding ligand precursor comprising a moiety having a 6-membered ring fused to an unsaturated 5-membered ring, said moiety being substituted on the fused ring structure by a silyloxy or germyloxy group.
The polymerization activity of the metallocene precursors of the invention is such that it is possible to use as a cocatalyst higher alkyl alumoxanes than the conventionally used methyl alumoxane (MAO). By a higher alkyl alumoxane is meant one containing alkyl groups containing 2 or more, eg. 2-10, carbons. This is highly advantageous since the higher alumoxanes are better characterised than MAO which appears to be a mixture of various compounds.
Thus viewed from a further aspect the invention provides a catalyst system comprising or produced by the reaction of a metallocene catalyst precursor according to the invention and an alkyl alumoxane comprising alkyl groups containing at least two carbon atoms, preferably a heterogeneous catalyst system further comprising a support material.
Viewed from a still further aspect the invention provides a method for the preparation of a heterogeneous catalyst system, said method comprising contacting a porous solid (eg. particulate) support, preferably an inorganic support such as silica or alumina, with (i) a higher alkyl alumoxane and a metallocene according to the invention or with the reaction product of a higher alkyl alumoxane and a metallocene according to the invention, and optionally (ii) an organometallic metallocene-activator.
In this method, an activator (optional component (ii)) will be used if the metallocene used requires activation, eg. where it does not contain any alkyl ligands. In this regard, the process described in FI 970349 and analogous processes are applicable.
Viewed from a yet still further aspect the invention provides a process for the catalysed polymerization of an olefin, wherein as catalyst is used a metallocene and a cocatalyst (preferably an alumoxane, especially preferably a higher alkyl alumoxane), or the reaction product of a metallocene and an alumoxane, the improvement comprising using as said catalyst a said cocatalyst and a metallocene according to the invention or a reaction product thereof.
The invention will now be described in more detail using as illustrat
Kallio Kalle
Kauhanen Jyrki
Knuuttila Hilkka
Leino Reko
Luttikhedde Hendrik
Birch, Stewart Kolasch & Birch, LL
Borealis Technology Oy
Nazario-Gonzalez Porfirio
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