Catalyst – solid sorbent – or support therefor: product or process – Zeolite or clay – including gallium analogs – And additional al or si containing component
Reexamination Certificate
2000-01-07
2002-09-24
Wu, David W. (Department: 1713)
Catalyst, solid sorbent, or support therefor: product or process
Zeolite or clay, including gallium analogs
And additional al or si containing component
C526S160000, C526S943000, C502S104000, C502S113000, C502S115000, C502S117000, C502S232000, C502S152000
Reexamination Certificate
active
06455457
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a novel supported polymerisation catalyst composition comprising a discrete metal complex, a support and an activator in particular an activator based on a Lewis acid, to a supported catalyst additionally comprising a Ziegler catalyst component and in particular to a method of preparing said supported catalyst.
The use of discrete metal complex based olefin polymerisation catalysts is well-known. Examples of such catalysts include metallocene complexes comprising a bis(cyclopentadienyl) zirconium complex for example bis(cyclopentadienyl) zirconium dichloride or bis(tetramethylcyclopentadienyl) zirconium dichloride disclosed in EP 129368, EP 206794, and EP 260130.
In such catalyst systems the discrete metal complex is used in the presence of a suitable activator. The activators most suitably used with such metal complexes are aluminoxanes, most suitably methyl aluminoxane or MAO. Other suitable activators are perfluorinated boron compounds.
It would however be beneficial to be able to use simpler and less costly activators with these discrete metal complexes.
WO 98/11144 describes catalyst systems based on discrete metal complexes comprising hetero-atom containing chelating ligands together with Lewis acids. Such systems have the advantage of not requiring the use of expensive aluminoxanes as activators. The aforementioned WO 98/11144 discloses that the discrete metal complexes may be supported and may also be used in the presence of Ziegler catalyst components. However there are no teachings of how such supported catalyst systems may be prepared.
We have now found that such supported catalyst systems based on discrete metal complexes which are suitable for the polymerisation of olefins and which do not require aluminoxane activators may be prepared by a specific preparative route which results in the metal complex being predominently fixed on the support.
SUMMARY OF THE INVENTION
Thus according to the present invention there is provided a method for preparing a supported catalyst composition suitable for the polymerisation of olefins said method comprising the steps of
(a) optionally pretreating a support,
(b) preparing a mixture of a neutral discrete metal complex and activator in a suitable solvent,
(c) contacting the support with the mixture from step (b), and
(d) removing the solvent to yield a free flowing powder, wherein the metal complex of step (b) has the formula.
(L)
p
MY
n
X
m
Z
q
where
L represents a ligand which remains attached to the metal under polymerisation conditions,
M is a Group IIIA element or Group IIIB, IVB, VB, VIB or VIII transition metal
Y is halogen or a group containing at least one O, S, N or P atom bound directly to M
X may be the same as Y or different and is chosen from halogen, a group containing at least one O, S, N or P atom bound directly to M, hydrogen or hydrocarbyl
Z is a neutral Lewis base
n>or=1
p>or=1
m>or=0
q>or=0.
DETAILED DESCRIPTION OF THE INVENTION
The support may be for example organic polymer, functionalised organic polymers, polysiloxanes, functionalised polysiloxanes, ion-exchange resins and porous inorganic metal oxides and chlorides for example silica, alumina or magnesium chloride.
The preferred support is silica, in particular dehydrated silica. The inorganic metal oxides and chloride supports may be dehydrated by conventional methods for example by calcination at elevated temperatures. Water may be removed from supports that are unstable to elevated temperatures by Dean and Stark separation. The dehydrated support material may optionally be pretreated with a Group I-III metal alkyl compound for example by heating in a suitable solvent such as toluene. Particularly preferred compound are those comprising alkyl groups having>2 carbon atoms for example trisiobutylaluminium.
The supported catalyst composition according to the present invention may be subsequently treated with an alkylating agent prior to the use as a polymerisation catalyst. A suitable alkylating agent is triisobutylaluminium.
It is a particular advantage of the present invention that the catalyst is not dissolved off the support in solvents normally used in polymerisation systems eg. alkanes, aromatics. In this way the metal complex is predominantly fixed to the support.
Particularly suitable complexes of the present invention are those having the general formula:
(L)
p
MY
n
X
m
Z
q
where
L represents an unsubstituted or substituted cyclopentadienyl ligand,
M is a Group IVB, VB, VIB or VIII transition metal
Y is halogen or a group containing at least one O, S, N or P atom bound directly to M
X may be the same as Y or different and is chosen from halogen, a group containing at least one O, S, N or P atom bound directly to M, hydrogen or hydrocarbyl
Z is a neutral Lewis base
n>or=1
p>or=1
m>or=0
q>or=0.
Suitable metal complexes include metallocene complexes comprising bis(cyclopentadienyl) complexes such as those disclosed for example in EP 129368 or EP 206794.
Also suitable for use in the present invention are complexes having constrained geometry such as those disclosed in EP 416815 or EP 420436.
For example complexes having the following general formula may be suitable:
wherein:
Cp* is a single &eegr;5-cyclopentadienyl or &eegr;5-substituted cyclopentadienyl group optionally covalently bonded to M through —Z—P— and corresponding to the formula:
wherein
R each occurrence is hydrogen or a moiety selected from halogen, alkyl, aryl, haloalkyl, alkoxy, aryloxy, silyl groups, and combinations thereof of up to 20 non-hydrogen atoms, or two or more R groups together form a fused ring system;
M is zirconium, titanium or hafnium bound in an &eegr;5 bonding mode to the cyclopentadienyl or substituted cyclopentadienyl group and is in a valency state of +3 or +4.
X each occurrence is hydride or a moiety selected from halo, alkyl, aryl, silyl, germyl, aryloxy, alkoxy, amide, siloxy, and combinations thereof (e.g. haloalkyl, haloaryl, halosilyl, alkaryl, aralkyl, silylalkyl, aryloxyaryl, and alkyoxyalkyl, amidoalkyl, amidoaryl) having up to 20 non-hydrogen atoms, and neutral Lewis base ligands having up to 20 non-hydrogen atoms;
n and m may be 0, 1 or 2.
Z is a divalent moiety comprising oxygen, boron, or a member of Group IVA of the Periodic Table of the Elements;
P is a linking group covalently bonded to the metal comprising nitrogen, phosphorus, oxygen or sulfur, or optionally Z and P together form a fused ring system.
The Y group has the same definition as above.
Illustrative but non-limiting examples of particularly suitable metal complexes for use in the catalyst composition of the present invention are those having the following Y groups in the above general formulae:
Halide
Trifluoromethanesulfonate
Methanesulfonate
Perchlorate
Fluorosulfonate
Nitrate
Pentafluorotellurate
Toluenesulfonates including halo substituted
Benzenesulfonates including halo substituted
Alkoxides
Aryloxides
HC(SO
2
CF
3
)
2
—
Oxalate and substituted oxalate
Acetate
Carboxylate
Acetylacetonate and substituted acetylacetonate
dithioacetylacetonate
Carbamate
Thiocarboxylate
Dithiocarboxylate
Thiocarbamate
Dithiocarbamate
Xanthate
Thioxanthate
Phosphinate
Thiophosphinate
Dithiophosphinate
dialkyldithiophosphate
amidinate
sulphurdiiminate
amidate
tropolonate
oxalate ester
nitrite
sulphinate
fluorosulphate
hydroxamate
thiohydroxamate
dithiohydroxamate
The preferred metal complexes are those in which the Y group is trifluoromethanesulfonate and in which X is the same as Y.
Preferred complexes are those in which M is zirconium, titanium or hafnium.
Suitable activators for use in the method of the present invention are Lewis acids.
Examples of suitable Lewis acids are alkyl aluminium compounds eg trimethyl aluminium, triisobutylaluminium, aryl aluminium compounds eg tris(pentafluorophenyl)aluminium, aluminium hydrides eg aluminium trihydride and mixed hydride/arylalkyl aluminium compounds eg di-isobutyl aluminium hydride, mono(pentafluorophenyl
BP Chemicals Limited
Choi Ling-Siu
Finnegan, Henderson Farabow, Garrett and Dunner L.L.P.
Wu David W.
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