1
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 ...


2
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 ...


3
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 ...


4
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 ...


5
Ewen John A, Reddy B R, Elder Michael J: Method for controlling the melting points and molecular weights of syndiotactic polyolefins using metallocene catalyst systems.. Fina Technology, January 5, 1994: EP0577581-A2 (96 worldwide citation)

This invention is for a method for varying the melting points and molecular weights of syndiotactic polyolefins by using metallocene catalysts with substituents on the aryl rings of a fluorene ligand in certain positions. Electron donating substituents, for example, dialkylamino, halogen, and alkoxy ...


6
Ewen John A, Razavi Abbas: Process and catalyst for producing syndiotactic polyolefins.. Fina Technology, January 17, 1990: EP0351392-A2 (90 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 ...


7
Ewen John A: Method for varying the melting points and molecular weights of polyolefins using metallocene catalyst systems.. Cosden Technology, October 5, 1988: EP0284708-A1 (90 worldwide citation)

The present invention provides a method for varying the melting points and molecular weights of polyolefins by changing the structure of the catalyst used in the polymerization. The catalysts that are useful in the present invention are chiral, stereorigid metallocene catalyst of the formula R''(C5R ...


8
Ewen John A, Elder Michael J: Process and catalyst for producing isotactic polyolefins.. Fina Technology, April 14, 1993: EP0537130-A1 (89 worldwide citation)

This invention is for a metallocene catalyst component useful in preparing isotactic polyolefins, a catalyst system using this component and a process for polymerizing olefins using the catalyst component. The catalyst component consists of a bridged metallocene in which one of the cyclopentadienyl ...


9
Ewen John A: Catalyst for producing hemiisotactic polypropylene.. Fina Technology, April 17, 1991: EP0423101-A2 (67 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 ...


10
Ewen John A: Hafnium metallocene catalyst for the polymerization of olefins.. Cosden Technology, October 5, 1988: EP0284707-A1 (54 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 ...