Patents by Inventor Steven Lee Stafford
Steven Lee 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).
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Patent number: 7868125Abstract: A process for producing non-solid-stated polyester polymer particles having one or more properties similar to polyester polymer particles that have undergone solid-state processing. In one embodiment, the process comprises (a) forming polyester polymer particles from a polyester polymer melt; (b) quenching at least a portion of the particles, (c) drying at least a portion of the particles, (d) crystallizing at least a portion of the particles, (e) annealing at least a portion of the particles. At all points during and between steps (b) through (e), the average bulk temperature of the particles is maintained above 165° C.Type: GrantFiled: February 27, 2009Date of Patent: January 11, 2011Assignee: Eastman Chemical CompanyInventors: Bruce Roger DeBruin, Tommy Ray Maddox, II, John Alan Wabshall, Jr., Steven Lee Stafford, Stephen Weinhold, Robert Noah Estep, Mary Therese Jernigan, Steven Paul Bellner, Alan George Wonders, John Guy Franjione
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Patent number: 7641950Abstract: 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: GrantFiled: January 21, 2008Date of Patent: January 5, 2010Assignee: Eastman Chemical CompanyInventors: Steven Lee Stafford, Mark Edward Stewart, Benjamin Bradford Gamble
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Publication number: 20090315219Abstract: Disclosed is a process for a melt processing a polyethylene terephthalate resin characterized by one or more of the following. The polyester particles may have at least two melting peaks wherein one of the at least two melting peaks is a low peak melting point with a range from 140° C. to 220° C., or from 140° C. to 230° C., and having a melting endothermic area of at least the absolute value of 1 J/g. The polyester particles may have one or more melting peaks at least one of which when measured on a DSC first heating scan has a heating curve departing from a baseline in the endothermic direction at a temperature of less than or equal to 200° C. The polyester particles may have an It.V. at their surface which is less than 0.25 dL/g higher than the It.V. at their center. The polyester particles may have not been solid stated. The melt processing device comprises a screw with a total length, L, a feed zone length in the range from 0.16L and 0.45L, a taper angle, ?, in the range from 0.5 degrees and 5.Type: ApplicationFiled: May 26, 2009Publication date: December 24, 2009Applicant: Eastman Chemical CompanyInventors: Marcus David Shelby, Michael Eugene Donelson, Frederick Leslie Colhoun, Steven Lee Stafford, Mark Edward Steward, Stephen Weinhold, Edward Lewis Boochard, Robert Noah Estep
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Publication number: 20090221785Abstract: A process for producing non-solid-stated polyester polymer particles having one or more properties similar to polyester polymer particles that have undergone solid-state processing.Type: ApplicationFiled: February 27, 2009Publication date: September 3, 2009Applicant: EASTMAN CHEMICAL COMPANYInventors: Bruce Roger DeBruin, Tommy Ray Maddox, II, John Alan Wabshall, JR., Steven Lee Stafford, Stephen Weinhold, Robert Noah Estep, Mary Therese Jernigan, Steven Paul Bellner, Alan George Wonders
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Patent number: 7399802Abstract: 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: GrantFiled: March 17, 2005Date of Patent: July 15, 2008Assignee: Eastman Chemical CompanyInventors: Steven Lee Stafford, Ronald Richard Light, Louis Thomas Germinario, Emerson Eston Sharpe, Jr.
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Publication number: 20080153962Abstract: 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: ApplicationFiled: March 3, 2008Publication date: June 26, 2008Inventors: Zhiyong Xia, Steven Lee Stafford, Susan Sims, Frederick Leslie Colhoun
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Patent number: 7375154Abstract: 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: GrantFiled: December 6, 2004Date of Patent: May 20, 2008Assignee: Eastman Chemical CompanyInventors: Steven Lee Stafford, Mark Edward Stewart, Benjamin Bradford Gamble
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Patent number: 7368523Abstract: 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: GrantFiled: September 16, 2005Date of Patent: May 6, 2008Assignee: Eastman Chemical CompanyInventors: Zhiyong Xia, Steven Lee Stafford, Susan Sims, Frederick Leslie Colhoun
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Patent number: 7288586Abstract: 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: GrantFiled: December 2, 2005Date of Patent: October 30, 2007Assignee: Eastman Chemical CompanyInventors: Mark Edward Stewart, Emerson Eston Sharpe, Jr., Benjamin Bradford Gamble, Steven Lee Stafford, Robert Noah Estep, James Carl Williams, Thomas Roger Clark
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Patent number: 6903154Abstract: 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 results 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: GrantFiled: February 13, 2004Date of Patent: June 7, 2005Assignee: Eastman Chemical CompanyInventors: Steven Lee Stafford, Ronald Richard Light, Louis Thomas Germinario, Emerson Eston Sharpe, Jr.
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Publication number: 20040228994Abstract: 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 results 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: ApplicationFiled: February 13, 2004Publication date: November 18, 2004Applicant: EASTMAN CHEMICAL COMPANYInventors: Steven Lee Stafford, Ronald Richard Light, Louis Thomas Germinario, Emerson Eston Sharpe
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Patent number: 6777048Abstract: A polyester pellet composition, a preform, and a bottle, each comprising a polyester polymer and silicon carbide. A polyester, and in particular a polyethylene terephthalate polyester, bottle containing silicon carbide has a low coefficient of static friction and a low bottle sidewall haze.Type: GrantFiled: December 18, 2002Date of Patent: August 17, 2004Assignee: Eastman Chemical CompanyInventors: Donna Rice Quillen, Earl Edmondson Howell, Jr., Steven Lee Stafford
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Publication number: 20040122150Abstract: A polyester pellet composition, a preform, and a bottle, each comprising a polyester polymer and silicon carbide. A polyester, and in particular a polyethylene terephthalate polyester, bottle containing silicon carbide has a low coefficient of static friction and a low bottle sidewall haze.Type: ApplicationFiled: December 18, 2002Publication date: June 24, 2004Inventors: Donna Rice Quillen, Earl Edmondson Howell, Steven Lee Stafford
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Publication number: 20040101642Abstract: A thermoplastic composition such as a polyester composition including polyethylene terephthalate polymers containing glassy carbon, and the preforms, bottles, sheets, rods, tubes, films and other articles made from these compositions.Type: ApplicationFiled: November 26, 2002Publication date: May 27, 2004Inventors: Donna Rice Quillen, Earl Edmondson Howell, Steven Lee Stafford
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Publication number: 20030152726Abstract: Polyester containers having a reduced coefficient of friction (“COF”) are produced by increasing the surface roughness of the polyester using either thermal crystallization or solvent crystallization. Because the low COF reduces or eliminates friction between polyester containers, the containers do not become entangled and disrupt the manufacturing process. As a result, the containers move easily through typical conveying and filling lines in manufacturing processes that use the containers.Type: ApplicationFiled: June 27, 2002Publication date: August 14, 2003Inventors: Steven Lee Stafford, Lavonna Suzanne Buehrig, Louis Thomas Germinario, Eric Jon Moskala, David Paul Fischer, Michael Eugene Donelson, Steven Matthew Scheffer, Darrin James Nicholson, Maurice Harold Hodgson, Fabian Clarke Pike, Jeff Erich Neff
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Publication number: 20030039783Abstract: 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: ApplicationFiled: March 25, 2002Publication date: February 27, 2003Inventors: Steven Lee Stafford, Ronald Richard Light, Louis Thomas Germinario, Emerson Eston Sharpe
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Publication number: 20030001317Abstract: A method for reducing or eliminating plate-out during the process used to produce stretch blow molded containers from polyester preforms by crystallizing the low molecular weight polyester molecules in or on the preform exterior surface before stretch blow molding the preform into a container. The molecules are crystallized using a crystallization process selected from (1) treating the outer surface of the preform with a solvent that is capable of crystallizing low molecular weight polyester molecules in polyester or (2) heating the outer surface of the preform to a temperature and for a time suitable for crystallizing low molecular weight polyester molecules in polyester. Plate-out is reduced because the crystallized molecules do not migrate out of the preform and form plate-out deposits on the mold.Type: ApplicationFiled: June 27, 2002Publication date: January 2, 2003Applicant: Eastman Chemical CompanyInventors: Steven Lee Stafford, Lavonna Suzanne Buehrig, Louis Thomas Germinario, Terrill M. McGee, Gary Wayne Minnick, Eric Jon Moskala, Michael Eugene Donelson
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Publication number: 20020194895Abstract: An apparatus and method for determining the coefficient of friction for plastic articles having non-planar surfaces and particularly plastic articles having irregular and arcuate surfaces, such as thermoplastic bottles or preforms utilizes a stationary sample and a rotatable sample in contact with the stationary sample. A downward force is applied to the stationary sample while applying torque to the rotatable sample. The torque applied is computer controlled and at the moment of slip is detected. The amount of torque necessary for maintaining a constant speed is also computer controlled and recorded. From the torque measurements, the computer calculates the coefficient of friction between the two sample materials.Type: ApplicationFiled: May 23, 2002Publication date: December 26, 2002Applicant: Eastman Chemical CompanyInventors: Louis Thomas Germinario, James Edward Moore, Steven Lee Stafford
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Patent number: H2132Abstract: Polyester containers having a reduced coefficient of friction (“COF”) are produced by increasing the surface roughness of the polyester using either thermal crystallization or solvent crystallization. Because the low COF reduces or eliminates friction between polyester containers, the containers do not become entangled and disrupt the manufacturing process. As a result, the containers move easily through typical conveying and filling lines in manufacturing processes that use the containers.Type: GrantFiled: June 27, 2002Date of Patent: November 1, 2005Assignee: Eastman Chemical CompanyInventors: Steven Lee Stafford, Lavonna Suzanne Buehrig, Louis Thomas Germinario, Eric Jon Moskala, David Paul Fischer, Michael Eugene Donelson, Steven Matthew Scheffer, Darrin James Nicholson, Maurice Harold Hodgson, Fabian Clarke Pike, Jeff Erich Neff
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Patent number: H2088Abstract: A method for reducing or eliminating plate-out during the process used to produce stretch blow molded containers from polyester preforms by crystallizing the low molecular weight polyester molecules in or on the preform exterior surface before stretch blow molding the preform into a container. The molecules are crystallized using a crystallization process selected from (1) treating the outer surface of the preform with a solvent that is capable of crystallizing low molecular weight polyester molecules in polyester or (2) heating the outer surface of the preform to a temperature and for a time suitable for crystallizing low molecular weight polyester molecules in polyester. Plate-out is reduced because the crystallized molecules do not migrate out of the preform and form plate-out deposits on the mold.Type: GrantFiled: June 27, 2002Date of Patent: November 4, 2003Assignee: Eastman Chemical CompanyInventors: Steven Lee Stafford, Lavonna Suzanne Buehrig, Louis Thomas Germinario, Terrill M. McGee, Gary Wayne Minnick, Eric Jon Moskala, Michael Eugene Donelson