Patents by Inventor Robert T. Li

Robert T. Li 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).

  • Patent number: 11130828
    Abstract: Disclosed is a solution polymerization process, or, alternatively, a method of delivering powder catalysts to a solution polymerization reactor, comprising combining a homogeneous single-site catalyst precursor with ?-olefin monomers to form a polyolefin, wherein the homogeneous single-site catalyst precursor is in the form of (i) a dry powder, (ii) suspended in a aliphatic hydrocarbon solvent, or (iii) suspended in an oil or wax, wherein the homogeneous single-site catalyst precursor is at a concentration greater than 0.8 mmole/liter when suspended in the aliphatic hydrocarbon solvent prior to entering the solution polymerization reactor.
    Type: Grant
    Filed: September 11, 2019
    Date of Patent: September 28, 2021
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Peijun Jiang, Robert T. Li, Jay L. Reimers
  • Patent number: 10544246
    Abstract: Disclosed is a solution polymerization process, or, alternatively, a method of delivering powder catalysts to a solution polymerization reactor, comprising combining a homogeneous single-site catalyst precursor with ?-olefin monomers to form a polyolefin, wherein the homogeneous single-site catalyst precursor is in the form of (i) a dry powder, (ii) suspended in a aliphatic hydrocarbon solvent, or (iii) suspended in an oil or wax, wherein the homogeneous single-site catalyst precursor is at a concentration greater than 0.8 mmole/liter when suspended in the aliphatic hydrocarbon solvent prior to entering the solution polymerization reactor.
    Type: Grant
    Filed: July 10, 2017
    Date of Patent: January 28, 2020
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Peijun Jiang, Robert T. Li, Jay L. Reimers
  • Publication number: 20200002451
    Abstract: Disclosed is a solution polymerization process, or, alternatively, a method of delivering powder catalysts to a solution polymerization reactor, comprising combining a homogeneous single-site catalyst precursor with ?-olefin monomers to form a polyolefin, wherein the homogeneous single-site catalyst precursor is in the form of (i) a dry powder, (ii) suspended in a aliphatic hydrocarbon solvent, or (iii) suspended in an oil or wax, wherein the homogeneous single-site catalyst precursor is at a concentration greater than 0.8 mmole/liter when suspended in the aliphatic hydrocarbon solvent prior to entering the solution polymerization reactor.
    Type: Application
    Filed: September 11, 2019
    Publication date: January 2, 2020
    Inventors: Peijun Jiang, Robert T. Li, Jay L. Reimers
  • Publication number: 20180044453
    Abstract: Disclosed is a solution polymerization process, or, alternatively, a method of delivering powder catalysts to a solution polymerization reactor, comprising combining a homogeneous single-site catalyst precursor with ?-olefin monomers to form a polyolefin, wherein the homogeneous single-site catalyst precursor is in the form of (i) a dry powder, (ii) suspended in a aliphatic hydrocarbon solvent, or (iii) suspended in an oil or wax, wherein the homogeneous single-site catalyst precursor is at a concentration greater than 0.8 mmole/liter when suspended in the aliphatic hydrocarbon solvent prior to entering the solution polymerization reactor.
    Type: Application
    Filed: July 10, 2017
    Publication date: February 15, 2018
    Inventors: Peijun Jiang, Robert T. Li, Jay L. Reimers
  • Patent number: 7638670
    Abstract: The present invention provides a method of producing oligomers of olefins, comprising reacting olefins with a catalyst under oligomerization conditions. The catalyst can be the product of the combination of a chromium compound and a pyridyl amine or a heteroaryl-amine compound. In particular embodiments, the catalyst compound can be used to trimerize or tetramerize ethylene to 1-hexene, 1-octene, or mixtures of 1-hexene and 1-octene.
    Type: Grant
    Filed: August 8, 2008
    Date of Patent: December 29, 2009
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: David H. McConville, Lily Ackerman, Robert T. Li, Xiaohong Bei, Matthew C. Kuchta, Tom Boussie, John F. Walzer, Jr., Gary Diamond, Francis C. Rix, Keith A. Hall, Anne LaPointe, James Longmire, Vince Murphy, Pu Sun, Dawn Verdugo, Susan Schofer, Eric Dias
  • Patent number: 7638671
    Abstract: The present invention provides a method of producing oligomers of olefins, comprising reacting olefins with a catalyst under oligomerization conditions. The catalyst can be the product of the combination of a chromium compound and a heteroaryl-amine compound. In particular embodiments, the catalyst compound can be used to trimerize or tetramerize ethylene to 1-hexene, 1-octene, or mixtures of 1-hexene and 1-octene.
    Type: Grant
    Filed: June 27, 2008
    Date of Patent: December 29, 2009
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: David H. McConville, Lily Ackerman, Robert T. Li, Xiaohong Bei, Matthew C. Kuchta, Tom Boussie, John F. Walzer, Jr., Gary Diamond, Francis C. Rix, Keith A. Hall, Anne LaPointe, James Longmire, Vince Murphy, Pu Sun, Dawn Verdugo, Susan Schofer, Eric Dias
  • Publication number: 20080293899
    Abstract: The present invention provides a method of producing oligomers of olefins, comprising reacting olefins with a catalyst under oligomerization conditions. The catalyst can be the product of the combination of a chromium compound and a pyridyl amine or a heteroaryl-amine compound. In particular embodiments, the catalyst compound can be used to trimerize or tetramerize ethylene to 1-hexene, 1-octene, or mixtures of 1-hexene and 1-octene.
    Type: Application
    Filed: August 8, 2008
    Publication date: November 27, 2008
    Inventors: David H. McConville, Lily Ackerman, Robert T. Li, Xiahong Bei, Matthew C. Kuchta, Tom Boussie, John F. Walzer, JR., Gary Diamond, Francis C. Rix, Keith A. Hall, Anne LaPointe, James Longmire, Vince Murphy, Pu Sun, Dawn Verdugo, Susan Schofer, Eric Dias
  • Publication number: 20080269443
    Abstract: The present invention provides a method of producing oligomers of olefins, comprising reacting olefins with a catalyst under oligomerization conditions. The catalyst can be the product of the combination of a chromium compound and a heteroaryl-amine compound. In particular embodiments, the catalyst compound can be used to trimerize or tetramerize ethylene to 1-hexene, 1-octene, or mixtures of 1-hexene and 1-octene.
    Type: Application
    Filed: June 27, 2008
    Publication date: October 30, 2008
    Inventors: David H. McConville, Lily Ackerman, Robert T. Li, Xiaohong Bei, Mathew C. Kuchta, Tom Boussie, John F. Walzer, Gary Diamond, Francis C. Rix, Keith A. Hall, Anne LaPointe, James Longmire, Vince Murphy, Pu Sun, Dawn Verdugo, Susan Schofer, Eric Dias
  • Patent number: 7425661
    Abstract: The present invention provides a method of producing oligomers of olefins, comprising reacting olefins with a catalyst under oligomerization conditions. The catalyst can be the product of the combination of a chromium compound and a pyridyl amine or a heteroaryl-amine compound. In particular embodiments, the catalyst compound can be used to trimerize or tetramerize ethylene to 1-hexene, 1-octene, or mixtures of 1-hexene and 1-octene.
    Type: Grant
    Filed: March 9, 2006
    Date of Patent: September 16, 2008
    Assignee: ExxonMobil Chemicals Patents Inc.
    Inventors: David H. McConville, Lily Ackerman, Robert T. Li, Xiaohong Bei, Matthew C. Kuchta, Tom Boussie, John F. Walzer, Jr., Gary Diamond, Francis C. Rix, Keith A. Hall, Anne LaPointe, James Longmire, Vince Murphy, Pu Sun, Dawn Verdugo, Susan Schofer, Eric Dias
  • Patent number: 7414006
    Abstract: The present invention provides a method of producing oligomers of olefins, comprising reacting olefins with a catalyst under oligomerization conditions. The catalyst can be the product of the combination of a chromium compound and a heteroaryl-amine compound. In particular embodiments, the catalyst compound can be used to trimerize or tetramerize ethylene to 1-hexene, 1-octene, or mixtures of 1-hexene and 1-octene.
    Type: Grant
    Filed: March 9, 2006
    Date of Patent: August 19, 2008
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: David H. McConville, Lily Ackerman, Robert T. Li, Xiaohong Bei, Matthew C. Kuchta, Tom Boussie, John F. Walzer, Jr., Gary Diamond, Francis C. Rix, Keith A. Hall, Anne LaPointe, James Longmire, Vince Murphy, Pu Sun, Dawn Verdugo, Susan Schofer, Eric Dias
  • Patent number: 7297747
    Abstract: Olefin polymerization processes using catalyst systems based on metallocenes and olefin, in particular, propylene polymers obtainable thereby. The metallocenes may be represented by the formula: wherein M1 preferably is zirconium or hafnium; and R12 is different from hydrogen.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: November 20, 2007
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: James R. Hart, William T. Haygood, Terry J. Burkhardt, Robert T. Li
  • Patent number: 7122498
    Abstract: Metallocenes and catalyst systems for olefin polymerization derived therefrom. The metallocenes may be represented by the formula: wherein M1 preferably is zirconium or hafnium; and R12 is different from hydrogen.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: October 17, 2006
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: James R. Hart, William T. Haygood, Terry J. Burkhardt, Robert T. Li
  • Patent number: 7081543
    Abstract: The present invention relates to ligands and the synthesis of those ligands for use in metallocene complexes. More particularly, the present invention relates to the synthesis of diarylsilyl bridged biscyclopentadienes using diarylsilyldisulfonates. Even more particularly, the present invention describes Group IV metallocenes containing diarylsilyl bridged bis-cyclopentadienyl ligands prepared from contacting a diarylsilyldisulfonate with an organometallic indenyl reagent.
    Type: Grant
    Filed: July 13, 2005
    Date of Patent: July 25, 2006
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Francis C. Rix, Terry J. Burkhardt, Robert T. Li, William T. Haygood, Jr.
  • Patent number: 6960676
    Abstract: The present invention relates to ligands and the synthesis of those ligands for use in metallocene complexes. More particularly, the present invention relates to the synthesis of diarylsilyl bridged biscyclopentadienes using diarylsilyldisulfonates. Even more particularly, the present invention describes Group IV metallocenes containing diarylsilyl bridged bis-cyclopentadienyl ligands prepared from contacting a diarylsilyldisulfonate with an organometallic indenyl reagent.
    Type: Grant
    Filed: February 8, 2001
    Date of Patent: November 1, 2005
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Francis C. Rix, Terry J. Burkhardt, Robert T. Li, William T. Haygood, Jr.
  • Patent number: 6903229
    Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization. The metallocene compositions may be represented by the formula: wherein R3 are identical or different and are each a halogen atom, a C1-C10 alkyl group which may be halogenated, a C6-C10 aryl group which may be halogenated, a C2-C10 alkenyl group, a C7-C40-arylalkyl group, a C7-C40 alkylaryl group, a C8-C40 arylalkenyl group, a —NR?2, —SR?, —OR?, —OSiR?3 or —PR?2 radical, wherein R? is one of a halogen atom, a C1-C10 alkyl group, or a C6-C10 aryl group, and R9 and R11 are identical or different and are a Group 14 radical having from 1 to 20 carbon atoms or are each primary, secondary or tertiary butyl groups, aryl groups, isopropyl groups, fluoroalkyl groups, trialkyl silyl groups, or other groups of similar size.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: June 7, 2005
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Terry J. Burkhardt, Udo M. Stehling, James R. Hart, William T. Haygood, Jr., Robert T. Li, James C. Vizzini, Matthew C. Kuchta
  • Patent number: 6894179
    Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: May 17, 2005
    Assignee: Exxon Mobil Chemical Patents Inc.
    Inventors: Matthew C. Kuchta, Udo M. Stehling, Robert T. Li, William T. Haygood, Jr., Terry J. Burkhardt
  • Patent number: 6888017
    Abstract: This invention relates to bridged indenyl metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization. The bridge may be represented by the formula: wherein: R17 to R24 are identical or different, and are one of a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C6-C10 aryl group, a C6-C10 aryloxy group, a C2-C10 alkenyl group, a C7-C40 arylalkyl group, a C7-C40 alkylaryl group, a C8-C40 arylalkenyl group, or a halogen atom, or together are a conjugated diene which is optionally substituted with one or more hydrocarbyl, tri(hydrocarbyl)silyl groups or hydrocarbyl, tri(hydrocarbyl)silylhydrocarbyl groups, said diene having up to 30 atoms not counting hydrogen; or two or more adjacent radicals R17 to R24, including R20 and R21, together with the atoms connecting them form one or more rings; and M2 is carbon, silicon, germanium or tin.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: May 3, 2005
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Matthew C. Kuchta, Udo M. Stehling, Robert T. Li, William T. Haygood, Jr., Terry J. Burkhardt
  • Patent number: 6870016
    Abstract: Olefin polymerization processes using catalyst systems based on metallocenes and olefin, in particular, propylene polymers obtainable thereby. The metallocenes may be represented by the formula: ? wherein M1 preferably is zirconium or hafnium; and R12 is different from hydrogen.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: March 22, 2005
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Terry J. Burkhardt, James R. Hart, William T. Haygood, Robert T. Li
  • Patent number: 6809057
    Abstract: An olefin polymerization catalyst system, comprising a catalyst represented by the general formula CrR4, wherein each R is independently a hydrocarbyl or substituted hydrocarbyl, with the proviso that R may not be a cyclopentadienyl group, an activator represented by the general formula, MQ2, where M is a Group II metal, where each Q is independently an alkyl, or substituted alkyl; and a support. The support may be organic or inorganic. Ethylene and one or more olefins may be polymerized by the catalyst system.
    Type: Grant
    Filed: February 10, 2003
    Date of Patent: October 26, 2004
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Zerong Lin, Robert T. Li, Anthony N. Speca, Stanley J. Katzen, David H. McConville
  • Publication number: 20040157729
    Abstract: An olefin polymerization catalyst system, comprising a catalyst represented by the general formula CrR4, wherein each R is independently a hydrocarbyl or substituted hydrocarbyl, with the proviso that R may not be a cyclopentadienyl group, an activator represented by the general formula, MQ2, where M is a Group II metal, where each Q is independently an alkyl, or substituted alkyl; and a support. The support may be organic or inorganic. Ethylene and one or more olefins may be polymerized by the catalyst system.
    Type: Application
    Filed: February 10, 2003
    Publication date: August 12, 2004
    Inventors: Zerong Lin, Robert T. Li, Anthony N. Speca, Stanley J. Katzen, David H. McConville