Patents by Inventor Kenneth Wayne Leffew

Kenneth Wayne Leffew 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).

  • Patent number: 8835547
    Abstract: Particles comprising a bulk of fluoropolymer and a nucleus of fluorinated ionomer, dispersions of such particles, articles and coatings made from such particles.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: September 16, 2014
    Assignee: E I du Pont de Nemours and Company
    Inventors: Kenneth Wayne Leffew, Ralph Birchard Lloyd, Charles Joseph Noelke
  • Patent number: 8436054
    Abstract: A process for making an aqueous dispersion of fluorinated ionomer particles by polymerizing in a first polymerization step at least one fluorinated monomer having an ionic group in an aqueous polymerization medium in the presence of initiator, the polymerizing providing dispersed particulate of fluorinated ionomer, polymerizing in a second polymerization step at least one fluorinated monomer having an ionic group in the aqueous polymerization medium in the presence of the dispersed particulate of fluorinated ionomer and initiator to form the aqueous dispersion of particles of fluorinated ionomer, and suspending the first polymerization step prior to beginning the second polymerization step.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: May 7, 2013
    Assignee: E I du Pont de Nemours and Company
    Inventors: Ralph Munson Aten, Kenneth Wayne Leffew, Ralph Birchard Lloyd, Charles Joseph Noelke
  • Patent number: 8436053
    Abstract: A process for making an aqueous dispersion of fluorinated ionomer particles by providing dispersed particulate of fluorinated ionomer in an aqueous polymerization medium and polymerizing at least one fluorinated monomer having an ionic group in the aqueous polymerization medium in the presence of the dispersed particulate of fluorinated ionomer and initiator to form the aqueous dispersion of particles of fluorinated ionomer.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: May 7, 2013
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Kenneth Wayne Leffew, Ralph Birchard Lloyd, Charles Joseph Noelke
  • Patent number: 8153738
    Abstract: A process for making an aqueous dispersion of fluoropolymer particles by providing dispersed particulate of fluorinated ionomer in an aqueous polymerization medium and polymerizing at least one fluorinated monomer in the aqueous polymerization medium in the presence of the dispersed particulate of fluorinated ionomer and initiator to form the aqueous dispersion of particles of fluoropolymer.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: April 10, 2012
    Assignee: E I du Pont de Nemours and Company
    Inventors: Kenneth Wayne Leffew, Ralph Birchard Lloyd, Charles Joseph Noelke
  • Patent number: 8058376
    Abstract: A process for making an aqueous dispersion of fluoropolymer particles by polymerizing in a first polymerization step at least one fluorinated monomer having an ionic group in an aqueous polymerization medium in the presence of initiator, the polymerizing providing dispersed particulate of fluorinated ionomer, and polymerizing in a second polymerization step at least one fluorinated monomer in the aqueous polymerization medium in the presence of the dispersed particulate of fluorinated ionomer and initiator to form the aqueous dispersion of particles of fluoropolymer.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: November 15, 2011
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Ralph Munson Aten, Kenneth Wayne Leffew, Ralph Birchard Lloyd, Charles Joseph Noelke
  • Publication number: 20110152387
    Abstract: A process for making an aqueous dispersion of fluorinated ionomer particles by providing dispersed particulate of fluorinated ionomer in an aqueous polymerization medium and polymerizing at least one fluorinated monomer having an ionic group in the aqueous polymerization medium in the presence of the dispersed particulate of fluorinated ionomer and initiator to form the aqueous dispersion of particles of fluorinated ionomer.
    Type: Application
    Filed: December 18, 2009
    Publication date: June 23, 2011
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Kenneth Wayne Leffew, Ralph Birchard Lloyd, Charles Joseph Noelke
  • Publication number: 20100160465
    Abstract: A process for making an aqueous dispersion of fluorinated ionomer particles by polymerizing in a first polymerization step at least one fluorinated monomer having an ionic group in an aqueous polymerization medium in the presence of initiator, the polymerizing providing dispersed particulate of fluorinated ionomer, polymerizing in a second polymerization step at least one fluorinated monomer having an ionic group in the aqueous polymerization medium in the presence of the dispersed particulate of fluorinated ionomer and initiator to form the aqueous dispersion of particles of fluorinated ionomer, and suspending the first polymerization step prior to beginning the second polymerization step.
    Type: Application
    Filed: December 18, 2009
    Publication date: June 24, 2010
    Applicant: E.I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Ralph Munson Aten, Kenneth Wayne Leffew, Ralph Birchard Lloyd, Charles Joseph Noelke
  • Publication number: 20100160510
    Abstract: A process for making an aqueous dispersion of fluoropolymer particles by polymerizing in a first polymerization step at least one fluorinated monomer having an ionic group in an aqueous polymerization medium in the presence of initiator, the polymerizing providing dispersed particulate of fluorinated ionomer, and polymerizing in a second polymerization step at least one fluorinated monomer in the aqueous polymerization medium in the presence of the dispersed particulate of fluorinated ionomer and initiator to form the aqueous dispersion of particles of fluoropolymer.
    Type: Application
    Filed: December 18, 2009
    Publication date: June 24, 2010
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Ralph Munson Aten, Kenneth Wayne Leffew, Ralph Birchard Lloyd, Charles Joseph Noelke
  • Publication number: 20100160490
    Abstract: A process for making an aqueous dispersion of fluoropolymer particles by providing dispersed particulate of fluorinated ionomer in an aqueous polymerization medium and polymerizing at least one fluorinated monomer in the aqueous polymerization medium in the presence of the dispersed particulate of fluorinated ionomer and initiator to form the aqueous dispersion of particles of fluoropolymer.
    Type: Application
    Filed: December 18, 2009
    Publication date: June 24, 2010
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Kenneth Wayne Leffew, Ralph Birchard Lloyd, Charles Joseph Noelke
  • Publication number: 20100160531
    Abstract: Particles comprising a bulk of fluoropolymer and a nucleus of fluorinated ionomer, dispersions of such particles, articles and coatings made from such particles.
    Type: Application
    Filed: December 18, 2009
    Publication date: June 24, 2010
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Kenneth Wayne Leffew, Ralph Birchard Lloyd, Charles Joseph Noelke
  • Publication number: 20100036064
    Abstract: This invention relates to semi-batch type copolymerization processes. More specifically, the processes of the present invention are directed to the production of compositionally uniform copolymers, including the production of such copolymers from dissimilar monomers, e.g., from monomers with significantly different reactivity ratios.
    Type: Application
    Filed: December 18, 2007
    Publication date: February 11, 2010
    Applicant: E.I. DU PONR DE NEMOURS AND COMPANY
    Inventors: Kenneth Wayne Leffew, Troy Wayne Francisco
  • Patent number: 6835335
    Abstract: A process for forming solid particles comprising the steps of: combining in molten form a major component of a crystallizable condensation homopolymer and a minor component of a non-crystallizable condensation polymer, wherein the crystallizable condensation homopolymer and the non-crystallizable condensation polymer each have a degree of polymerization of 10 to less than 48 prior to the combining; mixing the combined crystallizable condensation homopolymer and non-crystallizable condensation polymer in molten form to form a mixture that comprises 10 to 30 mol % of the non-crystallizable condensation polymer; forming the mixture into droplets; exposing the droplets to a thermal environment which results in the bulk of the droplet reaching within 15 seconds a temperature within ±10° C.
    Type: Grant
    Filed: May 17, 2002
    Date of Patent: December 28, 2004
    Assignee: Invista North America S.รก.r.l.
    Inventors: Vivek Kapur, Govindasamy Paramasivan Rajendran, Kenneth Wayne Leffew
  • Publication number: 20030222363
    Abstract: A process for forming solid particles comprising the steps of: combining in molten form a major component of a crystallizable condensation homopolymer and a minor component of a non-crystallizable condensation polymer, wherein the crystallizable condensation homopolymer and the non-crystallizable condensation polymer each have a degree of polymerization of 10 to less than 48 prior to the combining; mixing the combined crystallizable condensation homopolymer and non-crystallizable condensation polymer in molten form to form a mixture that comprises 10 to 30 mol % of the non-crystallizable condensation polymer; forming the mixture into droplets; exposing the droplets to a thermal environment which results in the bulk of the droplet reaching within 15 seconds a temperature within ±10° C.
    Type: Application
    Filed: May 17, 2002
    Publication date: December 4, 2003
    Inventors: Vivek Kapur, Govindasamy Paramasivan Rajendran, Kenneth Wayne Leffew
  • Patent number: 6476180
    Abstract: A process for producing an oriented shaped article that comprises the steps of (a) forming a shaped article comprising a block copolymer comprising 75% to 90% by weight of polyethylene terephthalate blocks and 10% to 25% by weight of polyethylene isophthalate blocks and (b) biaxially stretching the shaped article to a planar stretch ratio of 10 to 30.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: November 5, 2002
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Vivek Kapur, Kenneth Wayne Leffew, Govindasamy Paramasivam Rajendran
  • Patent number: 6451966
    Abstract: A process for increasing the rate of polymerization of low molecular weight polyester particles under solid state processing conditions whereby the progress of polymerization is preferred over the progress of crystallization for a given mass of particles.
    Type: Grant
    Filed: August 10, 2001
    Date of Patent: September 17, 2002
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Kenneth Wayne Leffew, Andrew Robert Witt
  • Patent number: 6409491
    Abstract: Disclosed is an improved extrusion die assembly for controlling the flow of polymer in a melt extrusion process. The die assembly is useful for extruding low molecular weight polymer melts.
    Type: Grant
    Filed: February 2, 2001
    Date of Patent: June 25, 2002
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Kenneth Wayne Leffew, David Peter Rule
  • Patent number: 5990265
    Abstract: Disclosed herein is a novel physical form of low molecular weight poly(trimethylene terephthalate). This form may be produced from molten low molecular weight poly(trimethylene terephthalate) material by means of rapid heat transfer from the material. The poly(trimethylene terephthalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight.
    Type: Grant
    Filed: June 22, 1998
    Date of Patent: November 23, 1999
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Elwood Neal Blanchard, Craig Robert Gochanour, Kenneth Wayne Leffew, Jan M. Stouffer
  • Patent number: 5830982
    Abstract: Disclosed herein is a novel crystalline form of low molecular weight poly(ethylene terephthalate). This crystalline form may be produced from molten or glassy low molecular weight poly(ethylene terephthalate) material by means of rapid heat transfer to or from the material. The poly(ethylene terephthalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight. A higher molecular weight polymer product having a unique physical form can be produced by solid-state polymerization of the low molecular weight poly(ethylene terephthalate).
    Type: Grant
    Filed: April 8, 1997
    Date of Patent: November 3, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Jan M. Stouffer, Elwood Neal Blanchard, Kenneth Wayne Leffew
  • Patent number: 5811496
    Abstract: This invention is directed to an improved process for producing a polyester oligomer. The process employs a pipeline reactor, having at least two stages, in which the degree of polymerization of an oligomeric feed material is raised from about 2-10 to about 2-40 and the ratio of carboxyl to hydroxyl end groups in the product is reduced. In a first stage of the process, a monomeric diol or polyol, such as ethylene glycol, is added to a melt of the oligomeric feed material. In a second stage of the process, the molecular weight of the oligomer is increased by removal of volatile reaction by-products, including water and polyol. The oligomer produced by the present invention may be used in making higher molecular weight polyesters.
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: September 22, 1998
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: John Maurice Iwasyk, Julie Anderson Rakestraw, Kenneth Wayne Leffew
  • Patent number: 5763104
    Abstract: Disclosed herein is a novel crystalline form of low molecular weight poly(trimethylene terephthalate). This crystalline form may be produced from molten or glassy low molecular weight poly(trimethylene terephthalate) material by means of rapid heat transfer to or from the material. The poly(trimethylene terephthalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight.
    Type: Grant
    Filed: December 12, 1996
    Date of Patent: June 9, 1998
    Assignee: E. I. du Pont de Nemours & Company
    Inventors: Jan M. Stouffer, Elwood Neal Blanchard, Kenneth Wayne Leffew