Patents by Inventor Steven Stafford

Steven Stafford 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).

  • Publication number: 20080118690
    Abstract: This invention relates to a polyester/polyamide blend having an excellent gas barrier property. More particularly, the present invention relates to combinations of a polyethylene terephthalate polymer and a polyamide polymer having an excellent gas barrier property and short oxygen scavenging induction periods, where the polyamide polymer has a C:A terminal group concentration ratio of 2:1 or more and a C+A terminal group concentration of at least 0.17 meq/g of polyamide polymer, wherein C represents a cumulative total of a terminal carboxyl group concentration and a terminal hydrocarbyl group concentration expressed in meq/g of polyamide, and A represents a terminal amine group concentration expressed in meq/g of polyamide.
    Type: Application
    Filed: January 21, 2008
    Publication date: May 22, 2008
    Applicant: EASTMAN CHEMICAL COMPANY
    Inventors: Steven Stafford, Mark Stewart, Benjamin Gamble
  • Publication number: 20080045637
    Abstract: A solid concentrate is provided having a combination of a transition metal present in an amount ranging from 1,000 to 40,000 ppm (weight by metal) and a polyester polymer present in an amount of at least 40 wt. % based on the weight of the concentrate. Concentrates made with highly modified polyester polymers are easy to compound with transition metals forming less brittle polymer upon melt extrusion. Bottle preforms and oxygen scavenging bottles can be made from these concentrates by combining solid polyester particles, solid polyamide particles, and solid these concentrate particles c into an melt processing zone, forming a melt, and forming an article directly from the melt. The b* color and the L* color and the haze levels of the preforms are improved over the preforms made with liquid carriers instead of solid concentrates.
    Type: Application
    Filed: August 22, 2007
    Publication date: February 21, 2008
    Applicant: EASTMAN CHEMICAL COMPANY
    Inventors: Mark Stewart, Emerson Sharpe, Benjamin Gamble, Steven Stafford, Robert Estep, James Williams, Thomas Clark
  • Publication number: 20080021142
    Abstract: A solid concentrate is provided having a combination of a transition metal present in an amount ranging from 1000 to 40,000 ppm (weight by metal) and a polyester polymer present in an amount of at least 40 wt. % based on the weight of the concentrate. Concentrates made with highly modified polyester polymers are easy to compound with transition metals forming less brittle polymer upon melt extrusion. Bottle preforms and oxygen scavenging bottles can be made from these concentrates by combining solid polyester particles, solid polyamide particles, and solid these concentrate particles c into an melt processing zone, forming a melt, and forming an article directly from the melt. The b* color and the L* color and the haze levels of the preforms are improved over the preforms made with liquid carriers instead of solid concentrates.
    Type: Application
    Filed: August 22, 2007
    Publication date: January 24, 2008
    Applicant: EASTMAN CHEMICAL COMPANY
    Inventors: Mark Stewart, Emerson Sharpe, Benjamin Gamble, Steven Stafford, Robert Estep, James Williams, Thomas Clark
  • Publication number: 20070066735
    Abstract: A polyester composition containing: a) aluminum atoms; and b) alkaline earth atoms or alkali metal atoms or alkali compound residues such as lithium atoms; and c) particles comprising titanium, zirconium, vanadium, niobium, hafnium, tantalum, chromium, tungsten, molybdenum, iron, or nickel atoms or combinations thereof, where the particles improve the reheat rate of the polyester composition. The polyester polymer compositions may also contain phosphorus catalyst deactivators/stabilizers. The polyester compositions and the articles made from the compositions such as bottle preforms and stretch blow molded bottles have improved reheat rate while maintaining low haze, high L*, a b* below 3, and have low levels of acetaldehyde. In the process for making the polyester polymer, the polymer melt is polycondensed in the presence of a) and b), with the particles c) added in a melt phase process or added to the polymer in an injection molding machine or extruder.
    Type: Application
    Filed: September 16, 2005
    Publication date: March 22, 2007
    Inventors: Donna Quillen, Rodney Armentrout, Mary Jernigan, Steven Stafford, Zhiyong Xia
  • Publication number: 20070020419
    Abstract: Polyesters and polyester containers having a reduced coefficient of friction and improved clarity are produced using an antiblock agent comprising a dried talc having from about 20 to about 300 ppm water or a fatty acid tethered talc. The use of these talcs result in polyesters and polyester containers having a coefficient of less than about 1.0 and a clarity with haze values of less than about 4%.
    Type: Application
    Filed: September 27, 2006
    Publication date: January 25, 2007
    Inventors: Steven Stafford, Ronald Light, Louis Germinario, Emerson Sharpe
  • Publication number: 20060287471
    Abstract: An acetaldehyde screening method is developed by feeding solid polymer sample particles having a free acetaldehyde (“AA”) content of 2 ppm or less, melting at least a portion of the sample particles to obtain a polymer sample having a heat history, and thereafter measuring the amount of acetaldehyde present in the polymer sample having the heat history. There is also provided a screening method in which the quantity of free or residual AA in or on a polymer sample is measured to obtain a first value AAf, the sample is melted, and thereafter the amount of AA generated upon remelting the polymer is measured to obtain a second value AAg.
    Type: Application
    Filed: June 16, 2005
    Publication date: December 21, 2006
    Inventors: Benjamin Schreiber, Eric Olsen, Steven Stafford, Jack Hensley, Donald Ellison
  • Publication number: 20060128861
    Abstract: A solid concentrate is provided having a combination of a transition metal present in an amount ranging from 1000 to 40,000 ppm (weight by metal) and a polyester polymer present in an amount of at least 40 wt. % based on the weight of the concentrate. Concentrates made with highly modified polyester polymers are easy to compound with transition metals forming less brittle polymer upon melt extrusion. Bottle preforms and oxygen scavenging bottles can be made from these concentrates by combining solid polyester particles, solid polyamide particles, and solid these concentrate particles c into an melt processing zone, forming a melt, and forming an article directly from the melt. The b* color and the L* color and the haze levels of the preforms are improved over the preforms made with liquid carriers instead of solid concentrates.
    Type: Application
    Filed: December 2, 2005
    Publication date: June 15, 2006
    Inventors: Mark Stewart, Emerson Sharpe, Benjamin Gamble, Steven Stafford, Robert Estep, James Williams, Thomas Clark
  • Publication number: 20060122306
    Abstract: This invention relates to a polyester/polyamide blend having an excellent gas barrier property. More particularly, the present invention relates to combinations of a polyethylene terephthalate polymer and a polyamide polymer having an excellent gas barrier property and short oxygen scavenging induction periods, where the polyamide polymer has a C:A terminal group concentration ratio of 2:1 or more and a C+A terminal group concentration of at least 0.17 meq/g of polyamide polymer, wherein C represents a cumulative total of a terminal carboxyl group concentration and a terminal hydrocarbyl group concentration expressed in meq/g of polyamide, and A represents a terminal amine group concentration expressed in meq/g of polyamide.
    Type: Application
    Filed: December 6, 2004
    Publication date: June 8, 2006
    Inventors: Steven Stafford, Mark Stewart, Benjamin Gamble
  • Publication number: 20060106146
    Abstract: Polyester compositions are disclosed that include polyester polymers or copolymers having incorporated therein titanium nitride particles that provide one or more of the following advantages: improving the reheat properties of the compositions, improving the color of the compositions through reduced yellowness, and improving the UV-blocking properties of the compositions. Processes for making such compositions are also disclosed. The titanium nitride particles may be incorporated in the polyester by melt compounding, or may be added at any stage of the polymerization, such as during the melt-phase of the polymerization. A range of particle sizes may be used, as well as a range of particle size distributions. The polyester compositions are suitable for use in packaging made from processes in which a reheat step is desirable, or decreased yellowness is desired, or increased resistance to the effects of ultraviolet light is desired, or any combination of the foregoing.
    Type: Application
    Filed: September 16, 2005
    Publication date: May 18, 2006
    Inventors: Zhiyong Xia, Steven Stafford, Susan Sims, Frederick Colhoun
  • Publication number: 20050165147
    Abstract: Polyesters and polyester containers having a reduced coefficient of friction and improved clarity are produced using an antiblock agent comprising a dried talc having from about 20 to about 300 ppm water or a fatty acid tethered talc. The use of these talcs result in polyesters and polyester containers having a coefficient of less than about 1.0 and a clarity with haze values of less than about 4%.
    Type: Application
    Filed: March 17, 2005
    Publication date: July 28, 2005
    Inventors: Steven Stafford, Ronald Light, Louis Germinario, Emerson Sharpe