Patents by Inventor Helmut B. Witteler

Helmut B. Witteler 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: 6670033
    Abstract: A process for the formation of a purified anhydrosugar alcohol is disclosed, whereby the resultant purified anhydrosugar alcohol has a purity of at least 99.8% and is substantially colorless. The anhydrosugar alcohol is purified by distillation, recrystallization from methanol, ethanol or ethylene glycol, melt recrystallization, or a combination thereof. Preferably, the purification is by distillation followed by recrystallization from methanol, ethanol or ethylene glycol. A test for determining the purity of the anhydrosugar alcohol is disclosed, wherein the color of the anhydrosugar alcohol after annealing at a temperature of at least 260° C. for at least four hours is examined. Alternatively, purity can be determined by examination of ultraviolet (UV) transmittance of the purified anhydrosugar alcohol at various wavelengths.
    Type: Grant
    Filed: November 27, 2001
    Date of Patent: December 30, 2003
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Michael A. Hubbard, Michael Wohlers, Helmut B. Witteler, Edward G. Zey, George Kvakovszky, Thomas H. Shockley, Larry F. Charbonneau, Norbert Kohle, Jochen Rieth
  • Patent number: 6359070
    Abstract: A polymer blend including a polyester and another thermoplastic polymer. The polyester includes terephthaloyl moieties and, optionally, other aromatic diacid moieties; and ethylene glycol moieties; optionally diethylene glycol moieties; isosorbide moieties; and, optionally one or more other diol moieties. The polyester has an inherent viscosity of at least about 0.35 dL/g.
    Type: Grant
    Filed: May 23, 2000
    Date of Patent: March 19, 2002
    Assignee: E. I. du Pont Nemours and Company
    Inventors: Garo Khanarian, Larry F. Charbonneau, Helmut B. Witteler
  • Patent number: 6140422
    Abstract: A polymer blend including a polyester and another thermoplastic polymer. The polyester includes terephthaloyl moieties and, optionally, other aromatic diacid moieties; and ethylene glycol moieties; optionally diethylene glycol moieties; isosorbide moieties; and, optionally one or more other diol moieties. The polyester has an inherent viscosity of at least about 0.35 dL/g.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: October 31, 2000
    Assignee: E.I. DuPont de Nemours and Company
    Inventors: Garo Khanarian, Larry F. Charbonneau, Helmut B. Witteler
  • Patent number: 6126992
    Abstract: An optical article made of a transparent polymer which includes terephthaloyl moieties, optionally, other aromatic diacid moieties; ethylene glycol moieties; isosorbide moieties; and, optionally, one or more other diol moieties, wherein the polymer has an inherent viscosity of at least about 0.35 dL/g as measured on a 1% solution (weight/volume) in o-chlorophenol at 25.degree. C.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: October 3, 2000
    Assignee: E.I. DuPont de Nemours and Company
    Inventors: Garo Khanarian, Larry F. Charbonneau, Helmut B. Witteler
  • Patent number: 6063464
    Abstract: A polyester polymer and method for making the polyester, wherein the polyester is prepared by (1) combining in a reactor a monomer containing a diacid moiety; a monomer comprising a diol moiety; and a monomer containing an isosorbide moiety; with a condensation catalyst suitable for condensing aromatic diacids and diols; and (2) heating the monomers and catalyst to polymerize the monomers to yield a polyester having an inherent viscosity of at least about 0.15 dL/g.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: May 16, 2000
    Assignee: HNA Holdings, Inc.
    Inventors: Larry F. Charbonneau, Robert E. Johnson, Helmut B. Witteler, Garo Khanarian
  • Patent number: 6063495
    Abstract: A polyester fiber made from a polymer having ethylene glycol moieties, isosorbide moieties and terepthaloyl moieties, and the method of making the fiber is described. The polyester fiber is used to form articles suitable for commercial, especially textile, and industrial uses, and has an inherent viscosity of at least 0.35 dL/g when measured as a 1% (weight/volume) solution of the polyester in o-chlorophenol at a temperature of 25.degree. C.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: May 16, 2000
    Assignee: HNA Holdings, Inc.
    Inventors: Larry F. Charbonneau, Garo Khanarian, Robert E. Johnson, Helmut B. Witteler, John A. Flint
  • Patent number: 6025061
    Abstract: A sheet made of a polyester which includes monomer units of terephthaloyl moieties, ethylene glycol moieties and isosorbide moieties is described. The polyester has an inherent viscosity of at least about 0.35 dL/g when measured as a 1% (weight/volume) solution of said polyester in o-chlorophenol at a temperature of 25.degree. C. The present invention also relates to a method of making the polyester sheet described above and a method of thermoforming the sheet into articles.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: February 15, 2000
    Assignee: HNA Holdings, Inc.
    Inventors: Garo Khanarian, Larry F. Charbonneau, Robert E. Johnson, Helmut B. Witteler, Russel G. Lee, Robert B. Sandor, Gregory V. Nelson
  • Patent number: 5959066
    Abstract: An isotropic polyester polymer and method for making the polyester is prepared by (1) combining in a reactor a monomer containing a terephthaloyl moiety; optionally, one or more other monomers containing an aromatic diacid moiety; a monomer comprising an ethylene glycol moiety; a monomer containing an isosorbide moiety; optionally, one or more other monomers containing a diol moiety; and optionally, a monomer containing a diethylene glycol moiety; with a condensation catalyst suitable for condensing aromatic diacids and glycols; and (2) heating the monomers and catalyst to polymerize the monomers to yield a polyester having an inherent viscosity of at least about 0.35 dL/g.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: September 28, 1999
    Assignee: HNA Holdings, Inc.
    Inventors: Larry F. Charbonneau, Robert E. Johnson, Helmut B. Witteler, Garo Khanarian