Patents by Inventor Charles W. Hengst

Charles W. Hengst 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).

  • Styrene copolymers in de-inking
    Publication number: 20020187905
    Abstract: Provided herein are compositions of matter useful in de-inking secondary fibers. A composition according to the invention includes an aqueous solution of an anionic form of a styrene-methacrylic acid copolymer. When a surfactant is used in combination with the copolymers herein described in a de-inking operation, a synergy is observed in that the combination of copolymer and surfactant combination together yield a recycled fiber product having higher brightness level and a lower effective residual ink concentration than recycled fibers produced using either the copolymer or surfactant alone in the same operation.
    Type: Application
    Filed: June 6, 2002
    Publication date: December 12, 2002
    Applicant: Huntsman Petrochemical Corporation
    Inventors: Duy T. Nguyen, Charles W. Hengst
  • Styrene copolymers in de-inking
    Patent number: 6488808
    Abstract: Provided herein are compositions of matter useful in de-inking secondary fibers. A composition according to the invention includes an aqueous solution of an anionic form of a styrene-methacrylic acid copolymer. When a surfactant is used in combination with the copolymers herein described in a de-inking operation, a synergy is observed in that the combination of copolymer and surfactant combination together yield a recycled fiber product having higher brightness level and a lower effective residual ink concentration than recycled fibers produced using either the copolymer or surfactant alone in the same operation.
    Type: Grant
    Filed: January 19, 2001
    Date of Patent: December 3, 2002
    Assignee: Huntsman Petrochemical Corporation
    Inventors: Duy T. Nguyen, Charles W. Hengst
  • Styrene copolymers in de-inking
    Patent number: 6482292
    Abstract: Provided herein are compositions of matter useful in de-inking secondary fibers. A composition according to the invention includes an aqueous solution of an anionic form of a styrene-methacrylic acid copolymer. When a surfactant is used in combination with the copolymers herein described in a de-inking operation, a synergy is observed in that the combination of copolymer and surfactant combination together yield a recycled fiber product having higher brightness level and a lower effective residual ink concentration than recycled fibers produced using either the copolymer or surfactant alone in the same operation.
    Type: Grant
    Filed: June 6, 2002
    Date of Patent: November 19, 2002
    Assignee: Huntsman Petrochemical Corporation
    Inventors: Duy T. Nguyen, Charles W. Hengst
  • Styrene copolymers in de-inking
    Publication number: 20020137644
    Abstract: Provided herein are compositions of matter useful in de-inking secondary fibers. A composition according to the invention includes an aqueous solution of an anionic form of a styrene-methacrylic acid copolymer. When a surfactant is used in combination with the copolymers herein described in a de-inking operation, a synergy is observed in that the combination of copolymer and surfactant combination together yield a recycled fiber product having higher brightness level and a lower effective residual ink concentration than recycled fibers produced using either the copolymer or surfactant alone in the same operation.
    Type: Application
    Filed: January 19, 2001
    Publication date: September 26, 2002
    Inventors: Duy T. Nguyen, Charles W. Hengst