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
2000-02-11
2004-02-24
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...
C502S103000, C502S110000, C502S114000, C502S117000
Reexamination Certificate
active
06696379
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to compounds that are useful as catalyst activator components. More particularly the present invention relates to such compounds that are particularly adapted for use in the polymerization of unsaturated compounds having improved activation efficiency and performance. Such compounds are particularly advantageous for use in a polymerization process wherein catalyst, catalyst activator, and at least one polymerizable monomer are combined under polymerization conditions to form a polymeric product.
It is previously known in the art to activate Ziegler-Natta polymerization catalysts, particularly such catalysts comprising Group 3-10 metal complexes containing delocalized &pgr;-bonded ligand groups, by the use of an activator. Generally in the absence of such an activator compound, also referred to as a cocatalyst, little or no polymerization activity is observed. A class of suitable activators are aluminoxanes, or alkylaluminoxanes, which are generally believed to be oligomeric or polymeric alkylaluminoxy compounds, including cyclic oligomers. The skilled artisan will appreciate that the precise chemical structure of individual alumoxane molecules including methyl alumoxane has eluded full characterization. The structure of methylalumoxane is postulated to consist of linear chains, cyclic rings, or polyhedra, which forms may interconvert in solution. Generally such compounds contain, on average about 1.5 alkyl groups per aluminum atom, and are prepared by reaction of trialkylaluminum compounds or mixtures of compounds with water (Reddy et al,
Prog. Poly. Sci
., 1995, 20, 309-367). The resulting product is in fact a mixture of various substituted aluminum compounds including especially, trialklyaluminum compounds. The amount of such free trialkylaluminum compound in the mixture generally varies from 1 to 50 percent by weight of the total product. Examples of alumoxanes include methylalumoxane (MAO) made by hydrolysis of trimethylaluminum as well as modified methylalumoxane (MMAO), made by hydrolysis of a mixture of trimethylaluminum and triisobutylaluminum. MMAO advantageously is more soluble in aliphatic solvents than is MAO.
A different type of activator compound is a Bronsted acid salt capable of transferring a proton to form a cationic derivative or other catalytically active derivative of such Group 3-10 metal complex. Preferred Bronsted acid salts are such compounds containing a cation/anion pair that is capable of rendering the Group 3-10 metal complex catalytically active. Suitable activators comprise fluorinated arylborate anions, most preferably, the tetrakis(pentafluorophenyl)borate anion. Additional suitable anions include sterically shielded diboron anions of the formula:
wherein:
S is hydrogen, alkyl, fluoroalkyl, aryl, or fluoroaryl, Ar
F
is fluoroaryl, and X
1
is either hydrogen or halide, disclosed in U.S. Pat. No. 5,447,895.
Examples of preferred charge separated (cation/anion pair) activators are protonated ammonium, sulfonium, or phosphonium salts capable of transferring a hydrogen ion, disclosed in U.S. Pat. Nos. 5,198,401, 5,132,380, 5,470,927, and 5,153,157, as well as oxidizing salts such as carbonium, ferrocenium and silyilium salts, disclosed in U.S. Pat Nos. 5,350,723, 5,189,192 and 5,626,087.
Further suitable activators for the above metal complexes include strong Lewis acids including (trisperfluorophenyl)borane and tris(perfluorobiphenyl)borane. The former composition has been previously disclosed for the above stated end use in EP-A-520,732, and elsewhere, whereas the latter composition is disclosed in Marks, et al.,
J. Am. Chem. Soc
., 118, 12451-12452 (1996). Additional teachings of the foregoing activators may be found in Chen, et al,
J. Am. Chem. Soc
. 1997, 119, 2582-2583, Jia et al,
Organometallics
, 1997, 16, 842-857. and Coles et al,
J. Am. Chem. Soc
. 1997, 119, 8126-8126. All of the foregoing salt and Lewis acid activators in practice are based on perfluorophenyl substituted boron compounds. Although the quantity of such activator compound used is quite low, residual boron and fluorinated benzene values remaining in the polymer may be detrimental to final polymer properties, such as applications requiring high dielectrical properties.
In U.S. Pat. No. 5,453,410, an alumoxane, particularly methylalumoxane, was disclosed for use in combination with cationic constrained geometry metal complexes, especially in a molar ratio of metal complex to alumoxane of from 1/1 to 1/50. This combination beneficially resulted in improved polymerization efficiency. Similarly, in U.S. Pat. Nos. 5,527,929, 5,616,664, 5,470,993, 5,556,928, 5,624,878, various combinations of metal complexes with trispentafluorophenyl boron cocatalyst, and optionally an alumoxane, were disclosed for use as catalyst compositions for olefin polymerization.
In EP-A-719,797, the use of two or more catalyst activators, specifically one or more aluminum compounds, such as aluminum trialkyls or alumoxanes, together with a boron compound, such as trispentafluorophenylborane were disclosed. The resulting polymer products were distinctly bimodal, thereby indicating that the catalyst activators did not interact to form a single, highly active activator differing from either of the initial reagents.
Despite the satisfactory performance of the foregoing catalyst activators under a variety of polymerization conditions, there is still a need for improved cocatalysts for use in the activation of various metal complexes under a variety of reaction conditions. In particular, it is desirable to remove boron containing contaminating compounds from such activator composition. Such boron containing contaminating compounds result primarily from ligand exchange with the alumoxane, and comprise trialkylboron compounds having from 1 to 4 carbons in each alkyl group, for example, trimethylboron, triisobutylboron, or mixed trialkylboron products. It would be desirable if there were provided compounds that could be employed in solution, slurry, gas phase or high pressure polymerizations and under homogeneous or heterogeneous process conditions having improved activation properties, that lack such trialkylboron species.
It is known that an exchange reaction between aluminum trialkyl compounds and tris(perfluorophenyl)borane occurs under certain conditions. This phenomenon has been previously described in U.S. Pat. No. 5,602,269.
SUMMARY OF THE INVENTION
According to the present invention there is now provided a composition of matter comprising:
a fluorohydrocarbyl-substituted alumoxane compound corresponding to the formula:
R
1
—(AIR
3
O)
m
—R
2
,
wherein:
R
1
independently each occurrence is a C
1-40
aliphatic or aromatic group;
R
2
independently each occurrence is a C
1-40
aliphatic or aromatic group or in the case of a cyclic oligomer, R
1
and R
2
together form a covalent bond;
R
3
independently each occurrence is a monovalent, fluorinated organic group containing from 1 to 100 carbon atoms or R
1
, with the proviso that in at least one occurrence per molecule, R
3
is a monovalent, fluorinated organic group containing from 1 to 100 carbon atoms, and
m is a number from 1 to 1000.
The composition may exist in the form of mixtures of compounds of the foregoing formula, and further mixtures with a trihydrocarbylaluminum compound, and may exist in the form of linear chains, cyclic rings, or polyhedra, which forms may interconvert in solution.
Additionally according to the present invention there is provided a catalyst composition for polymerization of an ethylenically unsaturated, polymerizable monomer comprising, in combination, the above described combination and a Group 3-10 metal complex, or the reaction product resulting from such combination.
Even further according to the present invention there is provided a process or polymerization of one or more addition polymerizable monomers comprising contacting the same, optionally in the presence of an inert aliphatic, alicyclic or aromatic hydrocarbon, with the above catalyst composition or
Carnahan Edmund M.
Chen Eugene Y.
Jacobsen Grant B.
Stevens James C.
Bell Mark L.
Pasterczyk J.
The Dow Chemical Company
LandOfFree
Supported modified alumoxane catalyst activator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Supported modified alumoxane catalyst activator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Supported modified alumoxane catalyst activator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3336901