Patents by Inventor Brad Lee Smith

Brad Lee Smith 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).

  • Process for recycling polyester materials
    Patent number: 7192988
    Abstract: The present invention is a process for recycling colored polyester. More specifically, colored polyester for recycling is depolymerized by the addition of glycol to form the monomer BHET. The BHET is contacted with activated carbon to remove some colorant. The remaining colorant is extracted with water, alcohol, or glycol to produce white, purified BHET. The white, purified BHET is separated from the extraction solvent (water, alcohol, or glycol) by filtering, decanting, or centrifuging, for example. The purified BHET monomer can be polymerized to polyethylene terephthalate meeting food contact specifications, using known polymerization processes.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: March 20, 2007
    Assignee: Invista North America S.AR.L.
    Inventors: Brad Lee Smith, Pravin Nayar, Gordon Shaw
  • Oxygen scavenging PET based polymer
    Patent number: 6544611
    Abstract: The present invention improves the effectiveness of the oxygen scavenging composition and maintains an excellent balance in the color properties of the polymer. The present invention relates to an improved oxygen scavenging PET based copolymer comprising from about 10 to about 120 ppm cobalt based on the PET polymer, and from about 15 to about 150 ppm zinc based on the PET polymer. The present invention also comprises a process for preparing a PET based oxygen scavenging copolymer, comprising the steps of: a) polymerizing a PET based polymer; b) adding Zn, Co, and an oxygen scavenging compound during said polymerizing step; c) copolymerizing said oxygen scavenging compound with said PET based polymer to form a copolymer; and d) extruding said copolymer.
    Type: Grant
    Filed: August 1, 2001
    Date of Patent: April 8, 2003
    Assignee: Arteva North America S.A.R.L.
    Inventors: David Anthony Schiraldi, Douglas John Sekelik, Brad Lee Smith
  • Oxygen scavenging PET based polymer
    Publication number: 20030031815
    Abstract: The present invention improves the effectiveness of the oxygen scavenging composition and maintains an excellent balance in the color properties of the polymer. The present invention relates to an improved oxygen scavenging PET based copolymer comprising from about 10 to about 120 ppm cobalt based on the PET polymer, and from about 15 to about 150 ppm zinc based on the PET polymer.
    Type: Application
    Filed: August 1, 2001
    Publication date: February 13, 2003
    Inventors: David Anthony Schiraldi, Douglas John Sekelik, Brad Lee Smith
  • Preparation of dimethyl terephthalate via the air oxidation of p-tolualdehyde
    Patent number: 6160159
    Abstract: The invention is directed to a process for the production of terephthalic acid and esters thereof from p-tolualdehyde or mixtures of p-tolualdehyde and p-xylene. The process of the invention can be carried out at lower temperatures and faster throughput than conventional processes using p-xylene. The use of p-tolualdehyde facilitates safety considerations by eliminating the induction period and high oxiding fluid concentrations encountered in typical oxidation reactions which use only p-xylene as the terephthalic acid or ester precursor.
    Type: Grant
    Filed: July 30, 1999
    Date of Patent: December 12, 2000
    Assignee: Arteva North America, S.a.r.l.
    Inventor: Brad Lee Smith