Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-01-21
2002-03-05
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S160000, C526S943000, C526S131000, C526S154000, C526S142000, C502S152000
Reexamination Certificate
active
06353071
ABSTRACT:
This invention is related to the field of organo-aluminoxane compositions.
BACKGROUND OF THE INVENTION
Organo-aluminoxanes have been found to be useful in a wide variety of chemical processes. For example, metallocene-organo-aluminoxane-catalysts, which can be formed by reacting certain metallocenes with certain organo-aluminoxanes, have been used to polymerize olefins. One of the earliest patents containing such a disclosure is U.S. Pat. No. 3,242,099 (the entire disclosure of which is hereby incorporated by reference).
Such metallocene-organo-aluminoxane-catalysts have been used to polymerize olefins using solution polymerization technology. Since such metallocene-organo-aluminoxane-catalysts are soluble in the solution polymerization medium, it has been generally observed that the resulting polymer has a low bulk density, as well as, other undesirable qualities.
Attempts to use such metallocene-organo-aluminoxane-catalysts to polymerize olefins using slurry polymerization technology have not been satisfactory. In slurry polymerization, the polymerization conditions are selected so that the desired polymer forms as discrete particles that are insoluble, or only sightly soluble, in the slurry polymerization medium, which is usually an aliphatic hydrocarbon. It has been observed that when such slurry polymerizations are carried out using such metallocene-organo-aluminoxane-catalysts, the desired polymer coats the interior surface of the slurry polymerization vessel. This coating of the slurry polymerization vessel's interior surface is detrimental. This is because such coating adversely effects the heat transfer from the slurry polymerization vessel. Additionally, such coating results in the need for periodic, if not continuous, cleaning of the slurry polymerization vessel, in order to prevent such vessel from fouling.
It is known that heterogeneous catalysts can be useful in slurry polymerizations. Heterogeneous catalysts are catalysts that are not soluble, or only slightly soluble, in the polymerization medium.
It is known that a solid form of organo-aluminoxane can be obtained by mixing an organo-aluminoxane solution with a counter solvent; however, this solid, when used as part of a heterogeneous catalyst, has been found to cause fouling in a slurry polymerization vessel. Even when a counter solvent is used to precipitate the organo-aluminoxane onto an hydrocarbon-insoluble-particulate-carrier, fouling is still a problem during slurry polymerizations.
Consequently, processes to produce organo-aluminum compositions, which are useful in producing heterogeneous catalysts that can be used in slurry polymerizations without fouling the polymerization vessel, are greatly needed. Additionally, since metallocene-organo-aluminoxane catalysts are expensive to produce, processes that reduce the cost of producing these catalyst, or processes that increase to usefulness of these catalysts, are desired.
SUMMARY OF THE INVENTION
It is an object of this invention to provide processes to produce organo-aluminoxane compositions.
In accordance with this invention, processes are provided that produce organo-aluminoxane compositions, said processes comprise:
(a) desiccating a first mixture, where said first mixture comprises organo-aluminoxane molecules intermixed with a solvent, to produce a first composition, where said first composition comprises organo-aluminoxane molecules;
(b) mixing said first composition with a solvent to produce a second mixture, where said second mixture comprises organo-aluminoxane molecules and said solvent;
(c) contacting said second mixture with a insolublization agent to produce said organo-aluminoxane compositions.
Additionally, polymerization processes that use catalyst that comprise organo-aluminoxane compositions produce in accordance with this invention.
Other objects and their advantages will become apparent to those skilled in the art having the benefit of the following.
DETAILED DESCRIPTION OF THE INVENTION
The organo-aluminoxane molecules useful in this invention can be made by various techniques are known in the art. For example, one technique involves the controlled addition of water to a trialkylaluminum. Another technique involves combining a trialkylaluminum and a hydrocarbon with a compound containing water of adsorption, or a salt containing water of crystallization. Additionally, solution containing organo-aluminoxane molecules can be obtain from a wide variety of commercial sources. Solutions containing organo-aluminoxane molecules obtained from commercial sources are generally in the form of hydrocarbon solutions. In general, these solutions also contain trialkylaluminum intermixed with the organo-aluminoxane molecules and the solvent.
The exact structure of organo-aluminoxanes molecules is often the subject of much discussion between scholars. It is generally accepted that the organo-aluminoxanes molecules are oligomeric, linear and/or cyclic molecules having repeating units of the formula:
Typically, linear organo-aluminoxane molecules are said to fit the following formula:
Oligomeric, cyclic organo-aluminoxanes are generally viewed as having the formula:
In the above formulas, R
1
is a hydrocarbyl group, typically a C
1
-C
8
alkyl group, and n is typically 2 to 100, preferably 10 to 35, m is typically 3 to 50.
Typically, in metallocene-organo-aluminoxanes catalysts used in the polymerization of olefins, R
1
is predominantly methyl or ethyl. Preferably about 30 mole percent of the repeating groups have an R
1
which is methyl, more preferably about 50 mole percent, and still more preferably about 70 mole percent of the repeating units have methyl as the R
1
group.
The insolublization agent useful in this invention is any molecule that can react with an organo-aluminoxane molecule to produce an organo-aluminoxane-insolublization-agent molecule (hereafter “organo-aluminoxane composition”) where said organo-aluminoxane composition is less soluble in the solvent that said reaction takes place in. Examples of suitable insolublization agents include, but are not limited to, oxides, peroxides, alkylene oxides, organic carbonates, organic compounds containing boron, and dihydrocarbyl Group IIA metal compounds.
For example, oxides useful in this invention are those molecules where the oxygen is free to react with the organo-aluminoxane molecules. Examples of such oxides include but are not limited to carbon monoxide and carbon dioxide.
For example, peroxides useful in this invention are represented by the formula R
2
OOR
3
, wherein R
2
and R
3
are individually selected from hydrogen, hydrocarbyl, and hydrocarbonyl radicals selected from the group consisting of alkyl, cycloalkyl, aryl, alkenyl, and alkynyl radicals containing 1 to 24 carbon atoms, preferably 1 to 18 carbon atoms and more preferably 1 to 12 carbon atoms, with the proviso that at least one of R
2
and R
3
is a hydrocarbyl or hydrocarbonyl radical. Preferably both R
2
and R
3
are individually hydrocarbyl radicals. Examples of suitable peroxides include diethyl peroxide, diacetyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide 2,5-dimethyl-(2,5-di(tert-butylperoxy) hexane, tert-amyl hydroperoxide, di-tert-amyl peroxide, dibenzoyl peroxide, dicrotonyl peroxide, bis(1-methyl-1-phenylethyl) peroxide, dilauryl peroxide, peroxybenzoic acid, peroxyacetic acid, tert-butyl perbenzoate, tert-amyl perbenzoate, peroxybutyric acid, peroxycinnamic acid, tert-butyl peracetate, and the like and mixtures thereof. Excellent results have been obtained with di-tert-butyl peroxide and it is currently preferred.
For example, alkylene oxides useful in this invention are represented by the formulas
wherein R
4
and R
5
are individually selected from the group consisting of hydrogen and alkyl radicals containing 1 to 12 carbon atoms, x is 0 to 12, preferably 0 to 8. Examples of suitable alkyl radicals include methyl, ethyl, propyl, isobutyl, isoamyl, octyl and decyl. Examples of suitable alkylene oxides include ethylene oxide, propylene oxide, 2,2-dimethyloxirane, 1,2-dimethyloxira
Geerts Rolf L.
Palackal Syriac J.
Welch M. Bruce
Bowman Edward L.
Choi Ling-Siu
Phillips Petroleum Company
Wu David W.
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