Patents by Inventor Xiaoliang Gao

Xiaoliang Gao has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Conversion of ethers to olefins
    Publication number: 20070100186
    Abstract: Ethers are cracked to olefins using a gamma-alumina catalyst in the presence of ammonia. The use of ammonia improves the selectivity to linear alpha olefins in comparison to cracking reactions in the absence of ammonia. The use of ammonia is convenient in comparison to known processes which employ alumina which as been treated with an amine. A preferred process produces octene-1 from 1-methoxyoctane.
    Type: Application
    Filed: October 18, 2006
    Publication date: May 3, 2007
    Inventors: Xiaoliang Gao, Andrzej Krzywickl, Stacy Johnston
  • Modified (MAO + aluminum alkyl) activator
    Publication number: 20060223960
    Abstract: A cocatalyst system for olefin polymerization comprises an aluminoxane (especially methylaluminoxane, or “MAO”), an aluminum alkyl and a halogenated phenol. The preferred halogenated phenol is pentafluorophenol. The use of pentafluorophenol permits the substitution of a portion of the MAO cocatalyst (which is expensive) with inexpensive aluminum alkyl. The cocatalyst is most preferably employed in combination with an organometallic catalyst having at lease one pi ligand.
    Type: Application
    Filed: February 28, 2006
    Publication date: October 5, 2006
    Inventors: Isam Jaber, John Swabey, Xiaoliang Gao, Charles Carter, Cliff Baar
  • Microorganism and the process for preparation of pravastatin sodium
    Publication number: 20060166340
    Abstract: The invention provides a novel microorganism producing pravastatin sodium, as well as the method for producing pravastatin sodium by using this microorganism. Micropolyspora roseoalba CGMCC 0624 of the invention is highly tolerant to mevastatin sodium, and has a high transformation rate of mevastatin sodium, and can produce pravastatin sodium with a high efficiency and low cost.
    Type: Application
    Filed: January 6, 2006
    Publication date: July 27, 2006
    Inventors: Mingquan Mei, Xiaoming Ji, Xiaoliang Gao, Yi Chen, Yan Li, Yong Yao, Zhonghao Zhuo, Jing Xu
  • Halogenated organic particles for catalyst supports
    Patent number: 7078469
    Abstract: Polymeric supports, which have been treated with a halosulfonic acid, increase the activity of single-site catalysts used with aluminoxane co-catalysts, resulting in improved ethylene polymerization. The present invention seeks to provide polymeric catalyst supports which have been treated with halosulfonic acid for improved activity.
    Type: Grant
    Filed: March 17, 2004
    Date of Patent: July 18, 2006
    Assignee: Nova Chemicals (International) S.A.
    Inventors: Peter Phung Minh Hoang, Xiaoliang Gao, Jessie Anne Leighton, Matthew Gerald Kowalchuk
  • Olefin polymerization catalyst system
    Patent number: 7001962
    Abstract: A catalyst system comprises 1) a group 4 organometallic catalyst and 2) an activator comprising a solid zirconium acid component and a metal alkyl. The catalyst system is inexpensive and is highly active for the polymerization of olefins. Preferred organometallic catalysts contain a cyclopentadienyl ligand, a phosphinimine ligand and or a ketimide ligand.
    Type: Grant
    Filed: September 16, 2003
    Date of Patent: February 21, 2006
    Assignee: Nova Chemicals (International) S.A.
    Inventors: Xiaoliang Gao, Jessie Leighton, Matthew Gerald Kowalchuk, P. Scott Chisholm
  • Novel borate activator
    Publication number: 20060009596
    Abstract: A catalyst system comprising (i) a bulky ligand catalyst compound; and (ii) a novel borate activator is active for olefin polymerization. The novel borate contains at least one chelating (divalent) ligand and contains at least one fluorine atom. Preferred borate activators are provided as anilinium or carbonium salts. Highly preferred borate salts contain two perfluorinated alkoxy chelating ligands. The catalyst system may be used to produce polyethylene for “end use” applications such as polyethylene film and molded polyethylene goods.
    Type: Application
    Filed: June 22, 2005
    Publication date: January 12, 2006
    Inventors: Xiaoliang Gao, Isam Jaber
  • Halogenated organic particles for catalyst supports
    Publication number: 20050075467
    Abstract: Polymeric supports, which have been treated with a halosulfonic acid, increase the activity of single-site catalysts used with aluminoxane co-catalysts, resulting in improved ethylene polymerization. The present invention seeks to provide polymeric catalyst supports which have been treated with halosulfonic acid for improved activity.
    Type: Application
    Filed: March 17, 2004
    Publication date: April 7, 2005
    Inventors: Peter Hoang, Xiaoliang Gao, Jessie Leighton, Matthew Kowalchuk
  • Olefin polymerization catalyst system
    Publication number: 20040097364
    Abstract: A catalyst system comprises 1) a group 4 organometallic catalyst and 2) an activator comprising a solid zirconium acid component and a metal alkyl. The catalyst system is inexpensive and is highly active for the polymerization of olefins. Preferred organometallic catalysts contain a cyclopentadienyl ligand, a phosphinimine ligand and or a ketimide ligand.
    Type: Application
    Filed: September 16, 2003
    Publication date: May 20, 2004
    Applicant: NOVA Chemicals (International) S.A.
    Inventors: Xiaoliang Gao, Jessie Leighton, Matthew Gerald Kowalchuk, P. Scott Chisholm
  • Catalyst for olefin polymerization
    Patent number: 6734266
    Abstract: A supported catalyst for olefin polymerization comprises a combination of a sulfated metal oxide support, an aluminoxane and an organometallic complex of a group 4 metal. The sulfated metal oxide may be quickly and conveniently prepared by, for example, contacting the precursor metal oxide with a sulfuric acid. The supported catalyst of this invention is highly active for olefin polymerization in comparison to conventional catalysts which are prepared with non-sulfated supports.
    Type: Grant
    Filed: February 13, 2002
    Date of Patent: May 11, 2004
    Assignee: Nova Chemicals (International) S.A.
    Inventors: Xiaoliang Gao, P. Scott Chisholm, Matthew Gerald Kowalchuk, Robert D. Donaldson
  • Halosulfonic acid treated catalyst support for olefin polymerization
    Patent number: 6730755
    Abstract: A supported catalyst for olefin polymerization comprises a combination of a novel metal oxide support and an activator which is an aluminoxane or a boron activator. The novel metal oxide support of this invention is a conventional particulate metal oxide support material (such as silica or alumina) which has been treated with a halosulfonic acid. A catalyst system which contains this novel catalyst support and a transition metal catalyst is highly active for olefin polymerization (in comparison to prior art catalyst systems which use a conventional metal oxide support).
    Type: Grant
    Filed: February 7, 2002
    Date of Patent: May 4, 2004
    Assignee: Nova Chemicals (Internation) S.A
    Inventors: Xiaoliang Gao, P. Scott Chisholm, Matthew Gerald Kowalchuk, Robert D. Donaldson
  • Supported phosphinimine polymerization catalyst
    Patent number: 6710143
    Abstract: A phosphinimine catalyst for olefin polymerization is supported on a directly fluorided metal oxide with an aluminoxane. This catalyst is highly active for olefin polymerization in comparison to prior art catalysts which use non-fluorided metal oxide supports. The directly fluorided metal oxide may be conveniently prepared by contacting the precursor metal oxide with a simple alkali metal salt (such as NaF) in an aqueous slurry.
    Type: Grant
    Filed: September 16, 2002
    Date of Patent: March 23, 2004
    Assignee: Nova Chemicals (International) S.A.
    Inventors: Xiaoliang Gao, P. Scott Chisholm, Robert D. Donaldson, Ian McKay
  • Bis-phosphinimine catalyst
    Patent number: 6649558
    Abstract: Organometallic complexes having two phosphinimine ligands 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 alumoxane. Preferred catalyst components contain titanium, zirconium, or hafnium and are activated with an ionic activator to form catalysts for ethylene polymerization.
    Type: Grant
    Filed: January 3, 2001
    Date of Patent: November 18, 2003
    Assignee: Nova Chemicals (International) S.A.
    Inventors: Stephen John Brown, Xiaoliang Gao, Daryll G. Harrison, Ian McKay, Linda Koch, Qinyan Wang, Wei Xu, Rupert Edward von Haken Spence, Douglas W. Stephan
  • Supported phosphinimine polymerization catalyst
    Publication number: 20030119661
    Abstract: A phosphinimine catalyst for olefin polymerization is supported on a directly fluorided metal oxide with an aluminoxane. This catalyst is highly active for olefin polymerization in comparison to prior art catalysts which use non-fluorided metal oxide supports. The directly fluorided metal oxide may be conveniently prepared by contacting the precursor metal oxide with a simple alkali metal salt (such as NaF) in an aqueous slurry.
    Type: Application
    Filed: September 16, 2002
    Publication date: June 26, 2003
    Applicant: NOVA Chemicals (International) S.A.
    Inventors: Xiaoliang Gao, P. Scott Chisholm, Robert D. Donaldson, Ian McKay
  • Halosulfonic acid treated catalyst support for olefin polymerization
    Publication number: 20030092563
    Abstract: A supported catalyst for olefin polymerization comprises a combination of a novel metal oxide support and an activator which is an aluminoxane or a boron activator. The novel metal oxide support of this invention is a conventional particulate metal oxide support material (such as silica or alumina) which has been treated with a halosulfonic acid. A catalyst system which contains this novel catalyst support and a transition metal catalyst is highly active for olefin polymerization (in comparison to prior art catalyst systems which use a conventional metal oxide support).
    Type: Application
    Filed: February 7, 2002
    Publication date: May 15, 2003
    Applicant: NOVA Chemicals (International) S.A.
    Inventors: Xiaoliang Gao, P. Scott Chisholm, Matthew Gerald Kowalchuk, Robert D. Donaldson
  • Catalyst for olefin polymerization
    Publication number: 20030087754
    Abstract: A supported catalyst for olefin polymerization comprises a combination of a sulfated metal oxide support, an aluminoxane and an organometallic complex of a group 4 metal. The sulfated metal oxide may be quickly and conveniently prepared by, for example, contacting the precursor metal oxide with a sulfuric acid. The supported catalyst of this invention is highly active for olefin polymerization in comparison to conventional catalysts which are prepared with non-sulfated supports.
    Type: Application
    Filed: February 13, 2002
    Publication date: May 8, 2003
    Applicant: NOVA Chemicals (International) S.A.
    Inventors: Xiaoliang Gao, P. Scott Chisholm, Matthew Gerald Kowalchuk, Robert D. Donaldson
  • Catalyst having a ketimide ligand
    Patent number: 6420300
    Abstract: 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 cyclopentadienyltype ligand). Preferred organometallic complexes may be activated with a so-called “substantially non coordinating anion” to form a low cost cocatalyst system which is excellent for the preparation of olefin copolymers having both high molecular weight and very low density.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: July 16, 2002
    Assignee: Nova Chemicals (International) S.A.
    Inventors: John McMeeking, Xiaoliang Gao, Rupert Edward von Haken Spence, Stephen John Brown, Dusan Jeremic
  • Iron olefin copolymerization catalyst
    Patent number: 6300435
    Abstract: Olefin Co- or homopolymers having a good molecular weight and short chain branching may be prepared in the presence of Group 8, 9 or 10 phosphinimine complex other than nickel.
    Type: Grant
    Filed: December 17, 1999
    Date of Patent: October 9, 2001
    Assignee: Nova Chemical (International) S.A.
    Inventors: Xiaoliang Gao, Qinyan Wang, Matthew Gerald Kowalchuk
  • Bis-phosphinimine catalyst
    Publication number: 20010007895
    Abstract: Organometallic complexes having two phosphinimine ligands 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 alumoxane. Preferred catalyst components contain titanium, zirconium, or hafnium and are activated with an ionic activator to form catalysts for ethylene polymerization.
    Type: Application
    Filed: January 3, 2001
    Publication date: July 12, 2001
    Applicant: NOVA CHEMICALS (INTERNATIONAL)S.A.
    Inventors: Stephen John Brown, Xiaoliang Gao, Daryll G. Harrison, Ian McKay, Linda Koch, Qinyan Wang, Wei Xu, Rupert Edward von Haken Spence, Douglas W. Stephan
  • Aluminum-phosphinimine complexes as catalysts for the (co)polymerization of ethylene
    Patent number: 6239061
    Abstract: Aluminum-phosphinimine complexes function as a component in a catalyst system for the (co)polymerization of ethylene. The inventive catalyst components form a highly productive polymerization system when activated with so-called “ionic activators”. The need for conventional transition metal catalyst metals (such as titanium, hafnium, zirconium or vanadium) is eliminated.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: May 29, 2001
    Assignee: Nova Chemicals (International) S.A.
    Inventors: Qinyan Wang, Xiaoliang Gao, John McMeeking, Wei Xu, Douglas W. Stephan
  • Bis-phosphinimine catalyst
    Patent number: 6239238
    Abstract: Organometallic complexes having two phosphinimine ligands 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 alumoxane. Preferred catalyst components contain titanium, zirconium, or hafnium and are activated with an ionic activator to form catalysts for ethylene polymerization.
    Type: Grant
    Filed: June 15, 1999
    Date of Patent: May 29, 2001
    Assignee: Nova Chemicals (International) S.A.
    Inventors: Stephen John Brown, Xiaoliang Gao, Daryll G. Harrison, Ian McKay, Linda Koch, Qinyan Wang, Wei Xu, Rupert Edward von Haken Spence, Douglas W. Stephan