Patents by Inventor David T. Williamson

David T. Williamson 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: 10633465
    Abstract: Selectively hydrogenated block copolymers having semi-crystalline blocks hard blocks and copolymer soft blocks having a combination of excellent physical properties and solvent resistance have been discovered. The block copolymer comprises at least one A block of hydrogenated, polymerized 1,3-butadiene and at least one B block which is a random copolymer or a controlled distribution copolymer of conjugated diene and mono vinyl aromatic monomers in which the conjugated diene monomer units are selectively hydrogenated. Polar functionalized block embodiments of the block copolymers are also disclosed. Compositions comprising the block copolymer and articles made from the block copolymer have also been discovered. A method is disclosed which provides highly isotropic, high strength melt cast films of block copolymers.
    Type: Grant
    Filed: March 22, 2017
    Date of Patent: April 28, 2020
    Assignee: Kraton Polymers U.S. LLC
    Inventors: John E. Flood, Carl L. Willis, Robert C. Bening, Hendrik De Groot, Xavier D. D. J. Muyldermans, David T. Williamson, Dale L. Handlin, Jr., Robert Dossett
  • Publication number: 20170275392
    Abstract: Selectively hydrogenated block copolymers having semi-crystalline blocks hard blocks and copolymer soft blocks having a combination of excellent physical properties and solvent resistance have been discovered. The block copolymer comprises at least one A block of hydrogenated, polymerized 1,3-butadiene and at least one B block which is a random copolymer or a controlled distribution copolymer of conjugated diene and mono vinyl aromatic monomers in which the conjugated diene monomer units are selectively hydrogenated. Polar functionalized block embodiments of the block copolymers are also disclosed. Compositions comprising the block copolymer and articles made from the block copolymer have also been discovered. A method is disclosed which provides highly isotropic, high strength melt cast films of block copolymers.
    Type: Application
    Filed: March 22, 2017
    Publication date: September 28, 2017
    Applicant: KRATON POLYMERS U.S. LLC
    Inventors: John E. Flood, Carl L. WILLIS, Robert C. Bening, Hendrik De Groot, Xavier D.D.J. Muyldermans, David T. Williamson, Dale L. Handlin, Jr., Robert Dossett
  • Patent number: 9040615
    Abstract: Compositions of thermoplastic polyesters containing dispersed nanoparticles of fibrous clay are made by polymerizing the polyester precursors in the presence of exfoliated fibrous clay that has not been organically modified. The compositions have good physical properties and can be melt molded into various articles. Many of these articles may be coated (painted) and are especially useful for appearance parts such as visible exterior automotive body parts.
    Type: Grant
    Filed: November 14, 2011
    Date of Patent: May 26, 2015
    Assignee: E I DU PONT DE NEMOURS AND COMPANY
    Inventors: David T. Williamson, Thomas M. Herrod, William M. Simmons, Henry Max Schleinitz
  • Patent number: 8691894
    Abstract: This invention relates to the preparation of polyamide block copolymers by sequential monomer addition. More particularly, it relates to catalysts capable of copolymerizing not only cyclic amides, but other monomers such as cyclic esters and epoxides as well, using sequential addition so as to produce useful and novel block copolymers.
    Type: Grant
    Filed: November 21, 2011
    Date of Patent: April 8, 2014
    Assignee: E I du Pont de Nemours and Company
    Inventors: David T. Williamson, Wilson Tam
  • Patent number: 8362106
    Abstract: Linear block copolymers that have at least one hydrophilic block and at least one hydrophobic block, wherein the hydrophilic block of the copolymer has at least one carboxylic acid functionality (or salt thereof) that can readily decarboxylate. These copolymers are useful as binders and/or dispersants in inkjet inks.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: January 29, 2013
    Assignee: E I du Pont de Nemours and Company
    Inventors: Kalindi Dogra, Kenneth Gene Moloy, Richard Douglas Bauer, David T. Williamson
  • Publication number: 20120292812
    Abstract: Compositions of thermoplastic polyesters containing dispersed nanoparticles of fibrous clay are made by polymerizing the polyester precursors in the presence of exfoliated fibrous clay that has not been organically modified. The compositions have good physical properties and can be melt molded into various articles. Many of these articles may be coated (painted) and are especially useful for appearance parts such as visible exterior automotive body parts.
    Type: Application
    Filed: November 14, 2011
    Publication date: November 22, 2012
    Applicant: E.I. DU PONT DE NEMOURS AND COMPANY
    Inventors: David T. Williamson, Thomas M. Herrod, Henry Max Schleinitz, William M. Simmons
  • Patent number: 8198355
    Abstract: The invention is directed to nanocomposite compositions that contain at least one thermoplastic polyamide and unmodified sepiolite-type clay nanoparticles. It, also, includes articles containing such compositions.
    Type: Grant
    Filed: June 8, 2007
    Date of Patent: June 12, 2012
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: David T. Williamson
  • Publication number: 20120062228
    Abstract: This invention relates to the preparation of polyamide block copolymers by sequential monomer addition. More particularly, it relates to catalysts capable of copolymerizing not only cyclic amides, but other monomers such as cyclic esters and epoxides as well, using sequential addition so as to produce useful and novel block copolymers.
    Type: Application
    Filed: November 21, 2011
    Publication date: March 15, 2012
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: David T. Williamson, Elizabeth Forrester McCord, Wilson Tam
  • Patent number: 8063169
    Abstract: This invention relates to the preparation of polyamide block copolymers by sequential monomer addition. More particularly, it relates to catalysts capable of copolymerizing not only cyclic amides, but other monomers such as cyclic esters and epoxides as well, using sequential addition so as to produce useful and novel block copolymers.
    Type: Grant
    Filed: May 31, 2007
    Date of Patent: November 22, 2011
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: David T. Williamson, Wilson Tam
  • Publication number: 20100324195
    Abstract: The invention is directed to nanocomposite compositions that contain at least one thermoplastic polyamide and unmodified sepiolite-type clay nanoparticles. It, also, includes articles containing such compositions.
    Type: Application
    Filed: June 8, 2007
    Publication date: December 23, 2010
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventor: David T. Williamson
  • Publication number: 20100273931
    Abstract: Linear block copolymers that have at least one hydrophilic block and at least one hydrophobic block, wherein the hydrophilic block of the copolymer has at least one carboxylic acid functionality (or salt thereof) that can readily decarboxylate. These copolymers are useful as binders and/or dispersants in inkjet inks.
    Type: Application
    Filed: December 3, 2008
    Publication date: October 28, 2010
    Applicant: E.I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Kalindi Dogra, Kenneth Gene Moloy, Richard Douglas Bauer, David T. Williamson
  • Patent number: 7635747
    Abstract: Mixtures or adducts of N-heterocyclic carbenes with metal amides or metal alkoxides are effective catalysts for the polymerization of cyclic amides. The catalysts are stable at polymerization temperatures, and the polymerization is rapid, resulting in high monomer conversion, high molecular weight, and a mechanically sound material.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: December 22, 2009
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Wilson Tam, David T. Williamson
  • Patent number: 7622543
    Abstract: N-heterocyclic carbenes are effective catalysts for the polymerization of macrocyclic polyester oligomers. The catalysts provide rapid polymerization, high monomer conversion, high molecular weight, and a mechanically sound material.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: November 24, 2009
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Wilson Tam, David T. Williamson
  • Publication number: 20090192254
    Abstract: Compositions of thermoplastic polyesters and sepiolite-type clay in which the clay is dispersed in the polyester as often fibrous particles whose smallest dimension is less than 100 nm are made by polymerizing the polyester precursors in the presence of the clay. The compositions have good physical properties and can be melt molded into various articles. Many of these articles may be coated (painted) and are especially useful for appearance parts such as visible exterior automotive body parts.
    Type: Application
    Filed: April 3, 2009
    Publication date: July 30, 2009
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: David T. Williamson, Thomas M. Herrod, William M. Simmons, Henry Max Schleinitz
  • Publication number: 20090186179
    Abstract: The present invention is a method for reducing the permeability of gases through polyester containers and films by incorporating into the polymer from which the container or film is formed an effective amount of exfoliated sepiolite-type clay.
    Type: Application
    Filed: March 23, 2009
    Publication date: July 23, 2009
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: DAVID T. WILLIAMSON, Henry M. Schleinitz, Richard Allen Hayes
  • Patent number: 7557157
    Abstract: Compounds containing a lanthanide rare earth element or yttrium are effective catalysts for the polymerization of macrocyclic polyester oligomers. The catalysts are stable at elevated temperatures, and the polymerization is rapid, resulting in high monomer conversion, high molecular weight, and a mechanically sound material.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: July 7, 2009
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: David T. Williamson
  • Patent number: 7550531
    Abstract: Metal amide and metal alkoxide species have been found to catalyze the ring opening polymerization of macrocyclic polyester oligomers. The catalysts provide rapid polymerization, high monomer conversion, high molecular weight, and a mechanically sound material.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: June 23, 2009
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Wilson Tam, David T. Williamson
  • Patent number: 7514499
    Abstract: N-heterocyclic carbenes are effective catalysts for the ring opening polymerization of cyclic amides. The catalysts provide rapid polymerization, high monomer conversion, high molecular weight, and a mechanically sound material.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: April 7, 2009
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Wilson Tam, David T. Williamson
  • Patent number: 7504472
    Abstract: This invention concerns a process for the preparation of semicrystalline polycarbonate compositions by synthesizing the polycarbonate in the presence of a sepiolite-type clay as a nucleating agent. The semicrystalline compositions produced are useful as starting materials for the production of high molecular weight polycarbonate by solid state polymerization.
    Type: Grant
    Filed: December 2, 2005
    Date of Patent: March 17, 2009
    Assignee: E. I. du Pont de Nemours + Company
    Inventor: David T. Williamson
  • Patent number: 7488772
    Abstract: Mixtures or adducts of N-heterocyclic carbenes with metal amides or metal alkoxides are effective catalysts for the polymerization of macrocyclic polyester oligomers. The catalysts are stable at polymerization temperatures, and the polymerization is rapid, resulting in high monomer conversion, high molecular weight, and a mechanically sound material.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: February 10, 2009
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Wilson Tam, David T. Williamson