Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Plural component system comprising a - group i to iv metal...
Reexamination Certificate
1999-04-29
2001-09-25
Bell, Mark L. (Department: 1755)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Plural component system comprising a - group i to iv metal...
C502S117000, C502S153000, C502S154000, C502S155000, C502S162000, C502S165000, C502S166000, C502S167000, C526S134000, C526S160000, C526S161000, C526S172000
Reexamination Certificate
active
06294495
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to transition metal catalyst systems for olefin polymerization, and more particularly to a reduced oxidation state transition metal catalyst system incorporating a tridentate ligand which is not based on cyclopentadienyl ligands.
BACKGROUND OF THE INVENTION
The use of discrete biscyclopentadienyl-based and monocyclopentadienyl-based metal complexes for the polymerization of olefins is well known in the art. In a few cases, olefin polymerization has been demonstrated starting from discrete catalyst precursor complexes with cyclopentadienyl-based ancillary ligand systems and reduced oxidation state metal centers such as in, for example, U.S. Pat. Nos. 5,374,696 and 5,494,874, both to Rosen, et. al.; WO 96/13529; and Theopold,
Acc. Chem. Res.
, vol. 23, pp.263-270 (1990). However, these catalyst precursor complexes do not exhibit C
2
or pseudo-C
2
symmetries, useful symmetries with many metallocene catalysts.
Recently, there has been an increased interest in identifying catalytic systems that incorporate non-cyclopentadienyl ancillary ligands. For example, Canich and Turner, U.S. Pat. No. 5,318,935 discloses bisamido Group 4 transition metal compounds and McConville, et. al.,
Macromolecules
, vol. 29, p. 5241 (1996), discloses bridged, dianionic, diamide ligands. These catalysts incorporate d
0
metals in their highest oxidation states. Both of WO 96/23010 and Gibson, et. al.,
Chem. Comm.
, pp. 849-85 (1998), disclose diimine-based ligands for metals in Groups 8-10. These diimine-based ancillary ligands are neutral donor ligands. Other demonstrated examples of catalyst precursor complexes incorporating non-cyclopentadienyl ancillary ligands and reduced oxidation state metals show these compounds to have very low activity, see WO 97/17379.
Organometallic compounds with anionic, non-cyclopentadienyl ligands, including those with reduced oxidation state metal centers and those structurally characterized as having C
2
or pseudo-C
2
symmetry, are known in the scientific literature. See, for example, Fryzuk,
Can. J. Chem.
, vol. 70, p. 2839 (1992); Edwards, et. al.,
J. Chem. Soc., Dalton Trans.
, p. 1253 (1989); and van Koten, et. al.,
J. Am. Chem. Soc.
, vol. 104, p. 5490 (1982). However, the teachings of these documents do not suggest potential utility of the compounds as polymerization catalysts or catalyst precursor compounds.
SUMMARY OF THE INVENTION
The present invention is directed to a catalyst complex based on a Group 4-9 first or second row transition metal in a reduced oxidation state and having a tridentate, monoanionic, non-cyclopentadienyl ligand containing Group 15 and/or 16 elements, the complex having been activated for olefin polymerization. The monoanionic tridentate ancillary ligand system consists of two Group 15 or 16 atoms bound to the transition metal through dative bonds and a Group 15 atom or aromatic ring carbon atom covalently bound to the transition metal. The covalently bound atom is linked to the datively bound Group 15 or 16 atoms by bridging groups each containing one or more Group 13-16 elements.
In a preferred embodiment, the present invention is directed to a tridentate catalyst system for the polymerization of &agr;-olefins comprising the reaction product of: (a) an organometallic complex of one of the formulae:
wherein M is a transition metal from Groups 4-9 in a reduced oxidation state; each X is independently halogen, alkoxide, aryloxide, amide, phosphide, hydride, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, hydrocarbyl- or halocarbyl-substituted organometalloid, or two X groups are joined and bound to the transition metal or an L group to form a ring structure, or one or more of X can contain an L group; L is a neutral donor group which stabilizes the complex; each E is independently a neutral donor group selected from Groups 15 and 16; E′ is a monoanionic donor group selected from Group 15; R has the same definition as X but may be the same or different; T is a bridging group containing an element or combination of elements from Groups 13-16; n is a number from 1 to 3 which is determined by counterbalancing the charge on the transition metal such that the transition metal remains in a reduced oxidation state and the overall charge on the complex is neutral; p is a number from 0 to 3 as needed to stabilize the complex; q is 1 or 2 such that E remains a neutral donor group; and (b) a catalyst activator compound. E is preferably selected from N, P, S and O and E′ is preferably N or P. M is preferably Ti, V, Cr, Mn, Fe or Co. The catalyst activator compound can be alkylalumoxane, an alkyl aluminum cocatalyst activator, or an ionizing noncoordinating anion precursor compound.
In another aspect, the present invention is directed to a polymerization process characterized by contacting one or more monomers polymerizable by coordination polymerization under suitable coordination polymerization conditions with the catalyst system described above. The monomers can be selected from the group consisting of ethylene, &agr;-olefins, cyclic olefins, non-conjugated diolefins, acetylenically unsaturated monomers, olefinically unsaturated aromatic monomers and C
20
-C
200
macromonomers. The monomers are preferably at least one member selected from the group consisting of ethylene and C
3
-C
20
&agr;-olefins. The catalyst system can also include a solid particulate support.
DETAILED DESCRIPTION OF THE INVENTION
The catalyst precursor transition metal compounds of the present invention can be generically represented by the following chemical formulae:
wherein each of the labeled substituents are as defined above.
The transition metal centers can be any metal from Groups 4-9, preferably titanium, vanadium, chromium, manganese, iron or cobalt, in a reduced oxidation state. As used in the specification and the appended claims, “a reduced oxidation state” means an oxidation number which is less than the highest attainable oxidation number of the metal. For example, preferred reduced oxidation state metals include Ti(II), Ti(III), V(II), V(III), V(IV), Cr(II), Cr(III), Cr(IV), Cr(V), Mn(II), Mn(III), Mn(IV), Fe(II), Fe(III), Co(II), Co(III), and the like. More preferred reduced oxidation state metals are those in the +3 oxidation state, e.g., V(III), Cr(III), etc.
Source compounds for the neutral donor group(s) L include any neutral Lewis base compound(s) capable of donating an electron pair to the metal center. Non-limiting examples include diethyl ether, trimethylamine, tetrahydrofuran, dimethylaniline, aniline, trimethylphosphine, n-butylamine, and the like.
The bridging group T contains any element or group of elements from Groups 13-16 such as, for example, B, C, N, O, Al, Si, P, S, Ge, Se or the like. T may be saturated or unsaturated. Preferred bridging groups include dialkyl, alkylaryl or diaryl silicon radical; a dialkyl, alkylaryl or diaryl germanium radical; alkyl or aryl phosphine; alkyl or aryl amine radical; an oxygen or sulfur radical; or a dihydrocarbyl radical having 1 or more carbon atoms such as methylene, ethylene and the like. Specific, nonlimiting examples of the T group which are suitable are dimethylsilyl, diethylsilyl, di-n-propylsilyl, diisopropylsilyl, di-n-butylsilyl, di-t-butylsilyl, di-n-hexylsilyl, methylphenylsilyl, ethylmethylsilyl, diphenylsilyl, di(p-t-butylphenethylsilyl), n-hexylmethylsilyl, cyclopentamethylenesilyl, cyclotetramethylenesilyl, cyclotrimethylenesilyl, dimethylgermanyl, diethylgermanyl, methylene, dimethylmethylene, diethylmethylene, ethylene, dimethylethylene, diethylethylene, dipropylethylene, propylene, dimethylpropylene, diethylpropylene, 1,1-dimethyl-3,3-dimethylpropylene, tetramethyldisiloxane, 1,1,4,4-tetramethyl-disilylethylene, oxygen and sulfur.
Exemplary hydrocarbyl radicals for X are methyl, ethyl, propyl, isopropyl, butyl, amyl, isoamyl, hexyl, isobutyl, heptyl, octyl, nonyl, decyl, cetyl, 2-ethylhexyl, phenyl and the like, with methyl being preferred. Exemplary halogen atoms for X include chlo
Bell Mark L.
ExxonMobil Chemicals Patent Inc.
Muller William G.
Pasterczyk J.
Runyan Charles E.
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