Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Plural component system comprising a - group i to iv metal...
Patent
1998-09-02
2000-06-13
Nazario-Gonzalez, Porfirio
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Plural component system comprising a - group i to iv metal...
502117, 502121, 502122, 502123, 502124, 526160, 526943, 556 11, 556 52, B01J 3100, C07F 1700, C07F 700
Patent
active
060749776
DESCRIPTION:
BRIEF SUMMARY
This invention relates to compositions of matter which are useful as addition polymerization catalysts, to a method for preparing these catalyst compositions and to a method of using these catalyst compositions. More particularly, this invention relates to improved olefin polymerization catalyst compositions comprising a Group 4 metal complex and to an improved method for polymerizing addition polymerizable monomers using the same.
Constrained geometry metal complexes and methods for their preparation are disclosed in EP-A-416,815; EP-A-468,651; EP-A-514,828; EP-A-520,732; WO93/19104; WO95/00526; as well as U.S. Pat. Nos. 5,055,438, 5,057,475, 5,096,867, 5,064,802, and 5,132,380.
In EP-A-418,044, published Mar. 20, 1991 and in U.S. Pat. No. 5,064,802 certain cationic derivatives of the foregoing constrained geometry catalysts that are highly useful as olefin polymerization catalysts are disclosed and claimed. In EP-A-520,732, certain borane reaction products of the foregoing constrained geometry catalysts are disclosed and a method for their preparation taught and claimed. In U.S. Pat. No. 5,453,410 combinations of cationic constrained geometry catalysts with an alumoxane were disclosed as suitable olefin polymerization catalysts.
For the teachings contained therein, the aforementioned United States Patents and published European Patent Applications (or the equivalent US patent or application) are herein incorporated in their entirety by reference thereto.
Although previously known cationic catalysts, especially the cationic catalysts disclosed in the foregoing applications and publications, have excellent activity, they are extremely sensitive to catalyst poisons, such as polar impurities, that may be contained in a polymerization mixture. Because of this fact, catalyst efficiencies and lifetimes have been limited and molecular weights of the resulting polymers have been reduced.
It is previously known in the art to utilize adjuvants such as trialkylboron and trialkylaluminum compounds to remove catalyst poisons from biscyclopentadienyl containing olefin polymerization catalysts. Disadvantageously however, such adjuvants have proven to be less effective in combating the inhibition of cationic catalysts, especially cationic, constrained geometry catalysts, and when used in the polymerization of olefin monomers, actually may interfere with the desired catalytic process. The previously disclosed U.S. Pat. No. 5,453,410 disclosed the combination of an alumoxane adjuvant with a cationic constrained geometry catalyst composition. However, alumoxanes are rather less soluble than is desired in aliphatic hydrocarbon solvents used in common polymerization systems. Additionally, alumoxanes are pyrophoric and are relatively expensive. Thus, it would be desirable to reduce the quantity of alumoxane used in a polymerization process or more desirably still, to eliminate use of alumoxanes entirely. Instead it would be desirable to utilize an adjuvant which is not pyrophoric and is more soluble in aliphatic hydrocarbons.
Finally, components in polymerization processes or their reaction products ultimately become incorporated into the polymer produced by the polymerization process unless a technique for their removal is available. Alumoxanes are relatively high molecular weight polymeric aluminum oxide compounds. Their presence in residual quantities in the polymerization product is generally not considered to be beneficial to polymer properties, and may actually degrade some polymer properties, particularly polymer clarity. An active component of the polymer catalyst that ultimately may be converted to a beneficial additive, such as an antioxidant, is a particularly desired objective of the present invention.
The present investigations have led to certain improved cationic catalyst compositions that are highly active as addition polymerization catalysts, desirably having improved resistance to catalyst poisons, and reduced cost. Moreover, certain of the compositions utilize components that under hydrolysis conditions resu
Rosen Robert K.
Stevens James C.
Tracy John C.
Nazario-Gonzalez Porfirio
The Dow Chemical Company
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