Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Plural component system comprising a - group i to iv metal...
Patent
1997-02-11
1998-09-15
Wu, David W.
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Plural component system comprising a - group i to iv metal...
502 87, 502117, 502152, 502155, 526160, 526943, C08F 464
Patent
active
058078002
ABSTRACT:
Stereospecific catalysts and processes for the stereotactic polymerization of ethylenically unsaturated monomers, specifically C.sub.3 -C.sub.4 alpha olefins involving a molecular sieve supported metallocene catalyst comprising a stereospecific metallocene catalyst component and a co-catalyst component. The metallocene catalyst component incorporates a metallocene ligand structure having two sterically dissimilar cyclopentadienyl ring structures coordinated with the central transition metal atom. Both the metallocene catalyst component and the co-catalyst component are supported on a molecular sieve having an average effective pore size which is less than the kinetic diameter of at least one of said ring structures. This supported catalyst is contacted in a polymerization reaction zone with an ethylenically unsaturated monomer which contains 3 or more carbon atoms or which is a substituted vinyl compound under polymerization conditions to produce stereospecific polymerization of the monomer. The supported catalyst incorporates a molecular sieve support having an average effective pore size within the range of 5-10 angstroms. The metallocene component can be an unbalanced metallocene having a ligand structure in which stereorigidity is imparted by means of a structural bridge extending between dissimilar cyclopentadienyl groups, for example, a fluorenyl group, a cyclopentadienyl group, of a ligand which exhibits bilateral symmetry. The specific zeolite supports are zeolite Y, zeolite X, mordenite, and zeolite .beta.. Others include various zeolites of the ZSM substitutional series, including ZSM-5, ZSM-11, and ZSM-12.
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Lopez Margarito
Shamshoum Edwar S.
Cheairs M. Norwood
Fina Technology, Inc.
Jackson William D.
Wheelington Jimmy D.
Wu David W.
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