Patents by Inventor Tak Wai Leung

Tak Wai Leung 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: 5874640
    Abstract: This invention relates to a process for separating one or more phosphorus acidic compounds from a reaction product fluid containing said one or more phosphorus acidic compounds, a metal-organophosphorus ligand complex catalyst and optionally free organophosphorus ligand which process comprises treating said reaction product fluid with an aqueous buffer solution sufficient to neutralize and remove at least some amount of said one or more phosphorus acidic compounds from said reaction product fluid.
    Type: Grant
    Filed: March 11, 1997
    Date of Patent: February 23, 1999
    Assignee: Union Carbide Chemicals & Plastics Technology Corporation
    Inventors: David Robert Bryant, Tak Wai Leung, Ernst Billig, Thomas Carl Eisenschmid, James Clair Nicholson, John Robert Briggs, Diane Lee Packett, John Michael Maher
  • Patent number: 5741942
    Abstract: This invention relates to a process for separating one or more phosphorus acidic compounds from a reaction product fluid containing said one or more phosphorus acidic compounds, a metal-organophosphite ligand complex catalyst and optionally free organophosphite ligand which process comprises treating said reaction product fluid with an aqueous buffer solution sufficient to neutralize and remove at least some amount of said one or more phosphorus acidic compounds from said reaction product fluid.
    Type: Grant
    Filed: November 26, 1996
    Date of Patent: April 21, 1998
    Assignee: Union Carbide Chemicals & Plastics Technology Corporation
    Inventors: David Robert Bryant, Tak Wai Leung, Ernst Billig, Thomas Carl Eisenschmid, James Clair Nicholson
  • Patent number: 5741943
    Abstract: This invention relates to a hydroformylation process which comprises reacting one or more olefinic unsaturated compounds with carbon monoxide and hydrogen in the presence of a metal-organopolyphosphite ligand complex catalyst and optionally free organopolyphosphite ligand, and an amount of a sterically hindered organophosphorus ligand different from the organopolyphosphite ligand of said metal-organopolyphosphite ligand complex catalyst, to produce one or more aldehydes. The sterically hindered organophosphorus ligands are useful as indicators of organopolyphosphite ligand depletion in said hydroformylation process.
    Type: Grant
    Filed: November 26, 1996
    Date of Patent: April 21, 1998
    Assignee: Union Carbide Chemicals & Plastics Technology Corporation
    Inventors: David Robert Bryant, Tak Wai Leung
  • Patent number: 5741944
    Abstract: This invention relates to a process for separating one or more phosphorus acidic compounds from a hydroformylation reaction product fluid containing said one or more phosphorus acidic compounds, a metal-organophosphite ligand complex catalyst and optionally free organophosphite ligand which process comprises treating said hydroformylation reaction product fluid with an aqueous buffer solution sufficient to neutralize and remove at least some amount of said one or more phosphorus acidic compounds from said hydroformylation reaction product fluid.
    Type: Grant
    Filed: November 26, 1996
    Date of Patent: April 21, 1998
    Assignee: Union Carbide Chemicals & Plastics Technology Corporation
    Inventors: David Robert Bryant, Tak Wai Leung, Ernst Billig, Thomas Carl Eisenschmid, James Clair Nicholson
  • Patent number: 5741945
    Abstract: This invention relates to processes which comprise reacting one or more reactants in the presence of a metal-organopolyphosphite ligand complex catalyst and optionally free organopolyphosphite ligand, and an amount of a sterically hindered organophosphorus ligand different from the organopolyphosphite ligand of said metal-organopolyphosphite ligand complex catalyst, to produce one or more products. The sterically hindered organophosphorus ligands are useful as indicators of organopolyphosphite ligand depletion in said processes.
    Type: Grant
    Filed: November 26, 1996
    Date of Patent: April 21, 1998
    Assignee: Union Carbide Chemicals & Plastics Technology Corporation
    Inventors: David Robert Bryant, Tak Wai Leung
  • Patent number: 5731472
    Abstract: This invention relates to a method of stabilizing a metal-organopolyphosphite ligand complex catalyst against deactivation in a process which comprises reacting one or more reactants in the presence of a metal-organopolyphosphite ligand complex catalyst and optionally free organopolyphosphite ligand to produce a reaction product fluid comprising one or more products, which method comprises conducting said process in the presence of one or more free heterocyclic nitrogen compounds sufficient to prevent and/or lessen deactivation of the metal-organopolyphosphite ligand complex catalyst.
    Type: Grant
    Filed: November 26, 1996
    Date of Patent: March 24, 1998
    Assignee: Union Carbide Chemicals & Plastics Technology Corporation
    Inventors: Tak Wai Leung, David Robert Bryant, Bernard Leslie Shaw