Patents by Inventor Pak T. Leung

Pak T. 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).

  • Aqueous polyurethane dispersion synthesis for adhesive thermoforming applications
    Patent number: 5155163
    Abstract: This invention relates to a process for preparing water dispersible polyurethane compositions. More specifically, this invention relates to a process for the preparation of self-emulsifying polyurethanes that form stable, homogeneous emulsions with water. The present invention also relates to the polyurethane compositions obtainable by this process, their dispersions in water, and to their use as adhesives in thermoforming applications.
    Type: Grant
    Filed: August 6, 1990
    Date of Patent: October 13, 1992
    Assignee: Uniroyal Adhesives and Sealants, Inc.
    Inventors: Palitha K. Abeywardena, Pak T. Leung
  • Polyurethane adhesive thermoforming lamination process employing water-based
    Patent number: 4853061
    Abstract: This invention presents new water-based adhesives suitable for use in thermoforming lamination systems. More particularly, this invention presents water-based adhesive-forming compositions comprising an aromatic polyurethane in water dispersion or emulsion and a compatible cross-linking agent; also includable in the compositions are thickening agents and pigments. These new adhesives, it has been found, exhibit bonding strengths and temperature resistance far superior to the solvent and water-based adhesives currently used in industrial applications, and are useful in thermoforming lamination processes. Also disclosed is a one-step thermoform lamination edge-folding process using the adhesive.
    Type: Grant
    Filed: November 2, 1987
    Date of Patent: August 1, 1989
    Assignee: Uniroyal Plastics Company, Inc.
    Inventor: Pak T. Leung
  • Water-based thermoforming adhesives
    Patent number: 4762880
    Abstract: This invention presents new water-based adhesives suitable for use in thermoforming lamination systems. More particularly, this invention presents water-based adhesive-forming compositions comprising an aromatic polyurethane in water dispersion or emulsion and a compatible cross-linking agent; also includable in the compositions are thickening agents and pigments. These new adhesives, it has been found, exhibit bonding strengths and temperature resistance far superior to the solvent and water-based adhesives currently used in industrial applications, and are useful in thermoforming lamination processes. Also disclosed is a one-step thermoform lamination edge-folding process using the adhesive.
    Type: Grant
    Filed: May 5, 1987
    Date of Patent: August 9, 1988
    Assignee: Uniroyal Plastics Co., Inc.
    Inventor: Pak T. Leung