Patents by Inventor David Bruce Hall

David Bruce Hall 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).

  • METHOD FOR THE MANUFACTURE OF HALOPHTHALIC ACIDS AND ANHYDRIDES
    Publication number: 20030181758
    Abstract: A method for the manufacture of halophthalic acid by liquid phase oxidation of halo-ortho-xylene is disclosed. The halophthalic acid may be dehydrated to form halophthalic anhydride which is useful in the synthesis of polyetherimide.
    Type: Application
    Filed: March 22, 2002
    Publication date: September 25, 2003
    Inventors: Robert Edgar Colborn, David Bruce Hall, Peter Koch, Gerald Oeckel
  • Method for purification of aromatic polyethers
    Publication number: 20020151675
    Abstract: Aromatic polyethers are prepared by displacement polymerization reaction in the presence of a water-immiscible solvent with boiling point at atmospheric pressure of greater than 110° C. and a density ratio to water of greater than 1.1:1 at 20-25° C. The polyethers are purified by processes comprising aqueous extraction, or filtration, or a combination thereof.
    Type: Application
    Filed: December 21, 2001
    Publication date: October 17, 2002
    Inventors: Norman Enoch Johnson, Raul Eduardo Ayala, Thomas Joseph Fyvie, Amy Rene Freshour, David Winfield Woodruff, Peter David Phelps, Ganesh Kailasam, Paul Edward Howson, Elliott West Shanklin, Lioba Maria Kloppenburg, David Bruce Hall, Pradeep Jeevaji Nadkarni