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
1998-12-10
2002-06-11
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, C502S128000, C502S152000, C502S153000, C502S154000, C502S155000
Reexamination Certificate
active
06403518
ABSTRACT:
BACKGROUND OF THE INVENTION
Transition metal catalysts, i.e., Ziegler-Natta and metallocenes, generally cannot be practically used for gas or slurry phase polymerization unless sufficiently supported. The use of supported catalysts offers the possibility of gas and slurry phase compatibility. Control of the particle size distribution of the polymeric product in the various polymerization processes eliminates or reduces the extent of reactor fouling.
Supported catalysts for olefin polymerization are well known in the art. These catalysts offer, among other things, the advantages of being useable in gas or slurry phase reactors, allowing the control of polymer particle size and thereby the control of the product bulk density. Gas phase reactors also eliminate the need for a solvent and the equipment for solvent handling during separation of the solvent from the resin. However, it is known that transition metal catalysts, particularly metallocene catalysts, are deactivated by supports that contain reactive functionalities, such as silicas which are oxide supports.
Accordingly, when using supported polyolefin catalysts, it is often desired to remove or reduce hydroxyl groups and other reactive functionalities from the support particles before and/or during manufacture of the supported catalyst. Removal of the reactive functionalities is often desirable since they will often react with the catalyst thereby deactivating it.
For example, in the past, various thermal and/or chemical treatments have been used in an effort to achieve dehydroxylation of the oxide particles.
Thermal treatments (i.e., calcining) are advantageous from the point that they do not add undesirable chemicals to the support and that they are relatively simple inexpensive processes. Unfortunately, thermal treatments are often ineffective for achieving a high degree of dehydroxylation. Further, for many porous oxide supports (e.g., silica gel), thermal treatments often result in an undesirable loss of pore volume, shrinkage of the pores and/or loss of surface area.
Furthermore, a variety of chemical treatments have been attempted to remove or deactivate reactive functionalities. Many types of chemicals have been used such as organo aluminum compounds, magnesium chloride/dehydrating agent combinations, organosilanes, halosilanes, silanes, etc. These various chemical processes are often expensive and may result in the addition of undesired or complicating constituents to an oxide support.
Thus, there remains a need for improved catalytic supports and supported activators having the undesired reactive functionalities deactivated.
Moreover, it is sometimes desirable to impart different characteristics to the support surface. The attachment of selected organic moieties to the support effects the characteristics of the support and hence the catalytic nature of the catalyst and/or activator placed on the support.
Thus it is an object of this invention to provide a method to deactivate reactive functionalities on catalytic supports as well to provide for a new support for transition metal catalysts and a supported catalytic activator.
Furthermore, it is an object of the present invention to provide a supported activator and a supported transition metal catalyst and/or catalyst system (support, activator and catalytic precursor) capable of not only producing polymers, but also providing a catalyst with hydrogen sensitivity so as to allow use of hydrogen to control molecular weight in olefin polymerization reactors.
SUMMARY OF THE INVENTION
The invention provides supports, supported catalytic activators and supported catalytic systems, wherein the supports have unique surface chemical compositions. The present invention further includes methods for making and using such compositions.
In particular, the present invention uses halogenated organic moieties that are covalently bonded to the support surface. Reactive functionalities on typical catalyst supports, such as hydroxyl groups, known as catalyst poisons, are consumed and the halogenated, most preferably fluorinated, organics are bonded to the support in their stead. These halogenated organic supports are ideal for supporting transition metal catalysts, particularly metallocene and/or Ziegler-Natta catalysts, particularly when a borate and/or aluminate catalyst activator is used. The support and supported catalytic activator of the present invention imparts enhanced properties, including improved activity and reduced reactor fouling while obtaining a resin particle of good morphology, bulk density, and enhanced comononer incorporation.
In one aspect, the present invention is a support composition represented by the following formula.
Carrier—L—RX
n
:
wherein the Carrier is not particularly limited and includes any material capable of forming a covalent bond to the halogenated organic RX
n
and includes inorganic carriers, inorganic oxide carriers and organic carriers. Of these, inorganic carriers and inorganic oxide carriers are particularly preferred.
RX
n
is any halogenated organic, wherein X is a halogen group and typically is fluorine, chlorine, iodine, and bromine and mixtures thereof; and n is a number from 1 to 9.
L represents the linkage resulting from the reaction of the support reactive functionality with a base (described below) that would be present on the support and capable of forming a covalent bond to the halogenated organic RX.
In another aspect of the invention, the invention provides a supported catalytic activator for use with transition metal catalytic precursor represented by the below formula.
Carrier—L—RX
n
:: [Compound A]
Where the Carrier, L, and RX
n
are as described above and Compound A is a compound capable of forming an ionic complex when reacted with a transition metal catalytic precursor and is further represented by the formulas
[Ct]
+
[M
n
(Q
1
−Q
n+1
)]
−
and M
n
Q
n
.
[Ct]
+
is an activating cation, which may be a Bronsted acid capable of donating a proton to the transition metal catalytic precursor resulting in a transition metal cation; or [Ct]
+
may be an abstracting moiety that is capable of reacting with a transition metal catalytic precursor resulting in the transition metal cation.
[M
n
(Q
1
−Q
n+1
]
−
is a compatible, large (bulky), non-coordinating anion capable of stabilizing the active transition metal catalytic species which is formed when the transition metal catalyst precursor is combined with the supported activator of present invention. These anionic coordination complexes comprise a plurality of lipophilic radicals covalently coordinated to and shielding a central charge-bearing metal or metalloid.
M
n
(Q
n
) is a large (bulky), non-coordinating, neutral species that is capable of stabilizing the active transition metal catalytic species which is formed when the transition metal catalyst precursor is combined with the supported activator of present invention. These anionic coordination complexes comprise a plurality of lipophilic radicals covalently coordinated to and shielding a central charge-bearing metal or metalloid.
In a third embodiment of the present invention, the support or the supported activator is combined (in any order of addition) with a transition metal catalytic precursor to provide a supported catalyst or a supported catalytic system. The support or the supported activator of the present invention may be combined with the transition metal catalytic precursor either prior to or during introduction to the polymerization reactor zone. Upon contact with the activator, the transition metal precursor reacts to form the active catalytic species.
The invention further includes the method for producing halogenated supports, supported catalytic activators, and catalyst systems as well, and methods for using the halogenated support in transition metal catalyst systems to polymerize olefins, diolefins, cyclic olefins and acetylenically unsaturated monomers to produce polymers, particularly
Artale Beverly J.
Bell Mark L.
Pasterozyk J.
W. R. Grace & Co.,-Conn.
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