1
John A Ewen: Hafnium metallocene catalyst for the polymerization of olefins. Fina Technology, John K Abokhair, Stuart L Watt, M Norwood Cheairs, December 27, 1988: US04794096 (318 worldwide citation)

The present invention provides a catalyst system for the polymerization and copolymerization of olefins with the system comprising a chiral, stereorigid hafnium metallocene catalyst in combination with an aluminum compound. The aluminum compound is preferably an alumoxane and may be a mixture of alu ...


2
John A Ewen, Abbas Razavi: Process and catalyst for producing syndiotactic polyolefins. Fina Technology, Stuart L Watt, John K Abokhair, M Norwood Cheairs, January 9, 1990: US04892851 (286 worldwide citation)

The invention provides a metallocene catalyst for use in preparing syndiotactic polyolefins. The catalyst comprises a bridged metallocene in which one of the cyclopentadienyl rings is substituted in a substantially different manner from the other ring. It was discovered that this type of catalyst is ...


3
Ewen John A, Elder Michael J: Preparation of metallocene catalysts for polymerization of olefins.. Fina Technology, May 8, 1991: EP0426637-A2 (222 worldwide citation)

This invention uses a new method of producing ionic metallocene compounds. These compounds are useful as catalysts for polymerization of olefins, primarily propylene. This method uses an ionizing agent which ionizes the neutral metallocene compound. The ionizing ionic compound does not contain an ac ...


4
Ewen John A, Elder Michael J: Metallocene catalysts with lewis acids and aluminum alkyls.. Fina Technology, May 15, 1991: EP0427697-A2 (205 worldwide citation)

This invention is for a catalyst system comprising a neutral metallocene compound, an aluminum alkyl and a Lewis acid. The Lewis acid must be of sufficient acidity to ionize a neutral metallocene compound to form a cationic metallocene catalyst. The ligands of the Lewis acid should not be reactive w ...


5
John A Ewen, Michael J Elder: Preparation of metallocene catalysts for polymerization of olefins. Fina Technology, Jim D Wheelington, M Norwood Cheairs, February 7, 1995: US05387568 (141 worldwide citation)

This invention uses a new method of producing ionic metallocene compounds. These compounds are useful as catalysts for polymerization of olefins, primarily propylene. This method uses an ionizing agent which ionizes the neutral metallocene compound. The ionizing ionic compound does not contain an ac ...


6
Elder Michael J, Ewen John A: Cationic metallocene catalysts based on triphenylcarbenium aluminum.. Fina Technology, December 8, 1993: EP0573403-A2 (140 worldwide citation)

Metallocene catalysts and their preparation and use in the polymerization of olefins. Specifically, the catalysts and processes relate to polymerization of olefins in which an aluminum ionizing agent containing a triphenylcarbenium ion is utilized in preparing the catalyst. The preparation of an ole ...


7
Michael J Elder, Abbas Razavi, John A Ewen: Process and catalyst for producing syndiotactic polyolefins. Fina Technology, William D Jackson, Jim D Wheelington, October 13, 1992: US05155080 (134 worldwide citation)

Syndiospecific catalysts and processes for the syndiotactic propagation of a polymer chain derived from an ethylenically unsaturated monomer which contains 3 or more carbon atoms or is a substituted vinyl compound. The catalysts comprise an unbalanced metallocene cation, characterized by a cationic ...


8
John A Ewen: Catalyst for producing hemiisotactic polypropylene. Fina Technology, Jim D Wheelington, July 30, 1991: US05036034 (105 worldwide citation)

This invention is for a metallocene compound which can be used in a catalyst system to produce hemiisotactic polymer. The compound is a bridged metallocene compound having dissimilar cyclopentadienyl groups and no bi-lateral symmetry. One example of the compound is isopropylidene(3-methylcyclopentad ...


9
Edwar S Shamshoum, David J Rauscher: Method of olefin polymerization utilizing hydrogen pulsing, products made therefrom, and method of hydrogenation. Fina Technology, J Mark Gilbreth, Jim Wheelington, Norwood Cheairs, April 14, 1998: US05739220 (103 worldwide citation)

An olefin polymerization process in which at least two introductions of hydrogen are made during the olefin polymerization reaction. Suitable catalysts include metallocenes of the general formula (Cp).sub.m TiX.sub.n, wherein Cp is a substituted or unsubstituted cyclopentadienyl ring, X is a halogen ...


10
Ewen John A, Elder Michael J: Addition of aluminium alkyl for improved metallocene catalyst.. Fina Technology, May 8, 1991: EP0426638-A2 (100 worldwide citation)

The invention is for a catalyst system for polymerization of olefins using an ionic mettallocene catalyst with aluminum alkyl. The metallocene catalyst is an ion pair formed from a neutral metallocene compound and an ionizing compound. The invention can be used in any method of producing ionic metal ...