1
Stephen John Brown, Christopher John Brooke Dobbin, Clayton Trevor Elston, Norman Dorien Joseph Aubee, Gilbert Alexander Arnould, Sarah Marshall, Lawrence Thomas Kale, Mark Weber: Heterogeneous/homogeneous copolymer. Nova Chemicals, Kenneth H Johnson, January 10, 2006: US06984695 (50 worldwide citation)

Novel polyethylene copolymer compositions prepared with a homogeneous catalyst system are characterized by having a unique high molecular weight, low comonomer (high density) fraction. These heterogeneous/homogeneous compositions may be prepared using a solution polymerization process in which the p ...


2
Stephen John Brown: Dual reactor polyethylene process using a phosphinimine catalyst. NOVA Chemicals, Kenneth H Johnson, April 16, 2002: US06372864 (43 worldwide citation)

A dual reactor process for the solution (co)polymerization of ethylene uses a catalyst having a phosphinimine ligand in each of the two reactors. In a preferred embodiment, the two reactors are operated at different temperatures and/or with different cocatalyst systems (such as “alumoxanes” and “ion ...


3
Isam Jaber, Stephen John Brown: Dual reactor ethylene polymerization process. Nova Chemical, Kenneth H Johnson, August 21, 2001: US06277931 (38 worldwide citation)

A dual reactor process for the solution and (co)polymerization of ethylene uses two different types of catalysts in the two reactors. A catalyst having a phosphinimine ligand is used in the first reactor. A Ziegler Natta catalyst is used in the second reactor. The process of this invention is compar ...


4
Douglas W Stephan, Jeff C Stewart, Stephen John Brown, John William Swabey, Qinyan Wang: High temperature solution polymerization process with phosphinimine cyclopentadienyl metal (GRP IV) complex. Nova Chemicals, Kenneth H Johnson, May 16, 2000: US06063879 (33 worldwide citation)

This invention is a solution process for the preparation of high molecular weight ethylene copolymers comprising contacting olefin monomers, with a catalyst system at a polymerization temperature at or above about 80.degree. C. with a catalyst system comprising an unbridged Group 4 metal compound ha ...


5
John McMeeking, Xiaoliang Gao, Rupert Edward von Haken Spence, Stephen John Brown, Dusan Jeremic: Catalyst having a ketimide ligand. Nova Chemicals, Kenneth H Johnson, September 5, 2000: US06114481 (29 worldwide citation)

A catalyst system comprises an organometallic complex of a group 4 metal having a ketimide ligand. The organometallic complex preferably also contains a cyclic ligand which forms a delocalized pi-bond with the metal (such as a cyclopentadienyl-type ligand). Preferred organometallic complexes may be ...


6
Stephen John Brown, John William Swabey, Christopher John Brooke Dobbin: Solution polymerization process. Nova Chemicals, Kenneth H Johnson, August 17, 2004: US06777509 (29 worldwide citation)

A solution polymerization process using a phosphinimine catalyst and a boron activator is conducted at a temperature of about 170° C. or greater in the presence of trialkyl aluminum to produce polyethylene having a comparatively broad molecular weight distribution. The polyethylene product produced ...


7
Douglas W Stephan, Jeff C Stewart, Stephen John Brown, John William Swabey, Qinyan Wang: Polymerization catalyst having a phosphinimine ligand. Nova Chemicals, Kenneth H Johnson, January 29, 2002: US06342463 (28 worldwide citation)

This invention is a solution process for the preparation of high molecular weight ethylene copolymers comprising contacting olefin monomers, with a catalyst system at a polymerization temperature at or above about 80° C. with a catalyst system comprising an unbridged Group 4 metal compound having a ...


8
Alexei Kazakov, Stephen John Brown, Christopher John Brooke Dobbin, Stanley Allan Grabow: Multimodal polyolefin pipe. Nova Chemicals, Kenneth H Johnson, November 4, 2003: US06642313 (20 worldwide citation)

A solution polymerization process in a series or parallel of two or more reactors at different temperatures is used to prepare a multimodal polyolefin resin of narrow molecular weight distribution. This resin is used to manufacture melt extruded pipe that has an improved performance at elevated temp ...


9
Stephen John Brown, Xiaoliang Gao, Qinyan Wang, Peter Zoricak, Rupert Edward von Haken Spence, Wei Xu: Phosphinimine/heteroatom catalyst component. NOVA Chemicals, Kenneth H Johnson, November 14, 2000: US06147172 (13 worldwide citation)

Organometallic complexes having a phosphinimine ligand, a (non-phosphinimine) heteroligand and at least one activatable ligand are catalyst components for olefin polymerization. Preferred polymerization systems are prepared by combining the organometallic complexes with an ionic activator and/or an ...


10
Rupert Edward von Haken Spence, Douglas W Stephan, Stephen John Brown, Dusan Jeremic, Qinyan Wang: Cyclopentadienyl/phosphinimine catalyst with one and only one activatable ligand. Nova Chemicals, Kenneth H Johnson, March 12, 2002: US06355744 (11 worldwide citation)

Organometallic complexes of titanium or zirconium having only three ligands (namely a cyclopentadienyl ligand, a phosphinimine ligand and an activatable ligand) are catalyst components for olefin polymerization. Preferred polymerization systems are prepared by combining the organometallic complexes ...