Organic compounds -- part of the class 532-570 series – Organic compounds – Heavy metal containing
Reexamination Certificate
1999-07-29
2001-05-22
Nazario-Gonzalez, Porfirio (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heavy metal containing
C556S043000, C556S070000, C556S087000, C556S170000, C556S465000, C556S052000, C502S120000, C502S122000, C526S160000, C526S943000
Reexamination Certificate
active
06235918
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to compositions of matter useful as a catalyst system, to a method for preparing these catalyst systems and to methods for polymerization and hydrogenation utilizing the catalyst system.
The use of Ziegler-Natta type catalysts in the polymerization of olefins is well known in the prior art. In general, such systems include a Group 4 metal compound with a metal or metalloid alkyl cocatalyst, such as aluminum alkyl cocatalyst for homogenous systems or metal oxide/organo-Lewis acid activated metal-oxide for heterogeneous systems. More broadly, it may be said to include a mixture of a Group 1,2 or 13 metal alkyl and a transition metal complex from the Group 4 metals, particularly titanium, zirconium, or hafnium with homogeneous/heterogeneous cocatalysts.
Many current Ziegler-Natta processes are designed for gas phase or slurry reaction in solution, and heterogenization of homogeneous Ziegler-type catalysts to optimize polymerization activity and polymer producing properties such as stereoregularity, molecular weight, thermal/rheogical characteristics, bulky and polar comonomer incorporation and microstructure are of great advantage. Studies of homogenous Ziegler-type catalysts have shown that highly electrophilic cationic species (e.g., A) can be produced using organo-Lewis acidic (alkide/hydride abstraction) and Brønstëd acidic (M-alkyl/H proteolysis) cocatalysts. In contrast, our overall understanding and application of analogous supported organometallic catalysts has been exclusively confined to Lewis acid surfaces or to organo-Lewis acid activated surfaces, since adsorption of metallocenes on conventional Brønstëd acid surfaces typically results in a catalytically inert &mgr;-oxo species (B) via protonolysis.
A design for a weakly coordinating anionic surface, derived from a very strongly Brønstëd acidic surface is an essential key to developing new heterogeneous Ziegler-Natta processes. Recently, sulfated zirconia and related solid acids have received considerable attention because of their claimed “superacidity” i.e., stronger acidity than 100% H
2
SO
4
(Hammett acid value H
o
=−12), a property which was suggested by paraffin isomerization at room temperature. These strongly acidic sulfate group activated surfaces can be superior candidates for supports rather than MAO (methylalumoxane) or organo-Lewis acid activated ones.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the subject invention to prepare and utilize a new class of olefin and arene hydrogenation and &agr;-olefin polymerization catalytic system.
A further object of the subject invention is a catalytic system which permits increased hydrogenation activity and polymerization activity.
Another object of the subject invention is a Ziegler-Natta type catalytic system which involves adsorbing the catalysts on sulfate-modified zirconia or related materials.
These and other objects are attained by the subject invention whereby in one embodiment, there is a new method of synthesis of highly active cationic metallocene hydrogenation and polymerization catalysts formed via protonolytic chemisorption by sulfated zirconia, including the novel catalytic system itself.
The catalyst systems of the subject invention are synthesized through adsorption of Ziegler-type catalysts on sulfate-modified zirconia or related materials. Ziegler-type catalysts are slurried with sulfate-modified zirconia in hydrocarbon solvents under anaerobic conditions, and thereby irreversibly adsorbed on the surface. Hydrogenation and polymerization catalyst systems are obtained from the dried, impregnated substrates.
More specifically, the subject invention involves methods for catalytic arene/olefin hydrogenation as well as olefin polymerization catalysis by organo-group 4 and 5 molecules such as
R
x
MR
1
y
, where
R, R
1
is a cyclopentadienyl ligand, an alkyl (C≦20), an alkenyl (C≦20), or an aryl group (C≦20)
M is Zr, Ti, Hf, V, Nb, Ta, Lanthanide, Al, Si, Ge, Sn, Pb, As, Sb, or B;
X is 0 to 3
Y is 0 to 3
The above compound is adsorbed on sulfate-modified zirconia (ZR), zirconia/tungsten oxide (ZRW), highly Brønstëd acidic sulfated zirconia (ZRSX, where x indicates the activation temperature), sulfated zirconia on coated silica, and other sulfated metal oxides based on Ti, Hf., Si, Sn, Fe, or Al.
REFERENCES:
Xuemin Song and Abdelhamid Sayari. Sulfated Zirconia-Based Strong-Acid Catalysts: Recent Progress. (1996) Catalysis Review—Science Engineering, vol. 39(3), p. 329-412.
V. Bolis, G. Magnacca, G. Cerrato, and C. Morterra. Microcalorimetric Characterization of Structural and Chemical Heterogeneity of Superacid SO4/ZrO2Systems. (1997) Langmuir, vol. 12, p. 888-894.
H. Armendariz, C. Sanchez Sierra, F. Figueras, B.Coq, C. Mirodatos, F. Lefebvre, and D. Tichit. Hydrogen Exchange between Sulfated Zirconias and per Deutero-Benzene as Characterization of Surface Acidity. (1997) Journal of Catalysis, vol. 171, p. 85-92.
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Dan Farcasiu, Jing Qi Li, Andreas Kogelbauer. The mechanism of conversion of hydrocarbons on sulfated metal oxides. Part IV. Kinetics of the reactions of methylcyclopentane on sulfated zirconia. (1997) Journal of Molecular Catalysis A. Chemical, vol. 124, pp. 67-78.
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Jean Sommer, David Habermacher, Mohammed Hachoumy, Roland Jost, Antoine Reynaud. The H/D exchange reaction occurring at low temperature between small alkanes and D2O exchanged solid acids. III. The role of alkenes and carbenium ions as reaction intermediates. (1996) Applied Catalysis A: General, vol. 146, p. 193-205.
V. Adeeva, J.W. de Haan, J. Jänchen, G.D. Lei, V. Schünemann, L.J.M. van de Ven, W.M.H. Sachtler, and R.A. van Santen. Acid Sites in Sulfated and Metal-Promoted Zirconium Dioxide Catalysts. (1995) Journal of Catalysis, vol. 151, p. 364-372.
Ahn Hongsang
Marks Tobin J.
Nazario-Gonzalez Porfirio
Northwestern University
Welsh & Katz Ltd.
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