Patents by Inventor Ronald L. Borchardt

Ronald L. Borchardt 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: 5357035
    Abstract: A process for the continuous production of polylactide polymers from lactic acid which incorporates removal of water or a solvent carrier to concentrate the lactic acid feed followed by polymerization to a low-molecular-weight prepolymer. This prepolymer is fed to a reactor in which a catalyst is added to facilitate generation of lactide, the depolymerization product of polylactic acid. The lactide generated is continuously fed to a distillation system as a liquid or vapor wherein water and other impurities are removed. The resultant purified liquid lactide is fed directly to a polymerization process.
    Type: Grant
    Filed: September 16, 1993
    Date of Patent: October 18, 1994
    Assignee: Cargill, Incorporated
    Inventors: Patrick R. Gruber, Eric S. Hall, Jeffrey J. Kolstad, Matthew L. Iwen, Richard D. Benson, Ronald L. Borchardt
  • Patent number: 5274073
    Abstract: A process for the continuous conversion of crude lactic acid to a substantially purified lactide or polylactide including the steps of polymerizing the lactic acid to form a prepolymer with subsequent depolymerization to form a crude lactide in the presence of a catalyst. The crude lactide is purified in an improved distillation system in which at least three fractions are formed with the substantially purified lactide removed as an intermediate boiling sidedraw stream. The substantially purified lactide may then be polymerized.
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: December 28, 1993
    Assignee: Cargill, Incorporated
    Inventors: Patrick R. Gruber, Eric S. Hall, Jeffrey J. Kolstad, Matthew L. Iwen, Richard D. Benson, Ronald L. Borchardt
  • Patent number: 5258488
    Abstract: A process for the continuous production of polylactide polymers from lactic acid which incorporates removal of water or a solvent carrier to concentrate the lactic acid feed followed by polymerization to a low-molecular-weight prepolymer. This prepolymer is fed to a reactor in which a catalyst is added to facilitate generation of lactide, the depolymerization product of polylactic acid. The lactide generated is continuously fed to a distillation system as a liquid or vapor wherein water and other impurities are removed. The resultant purified liquid lactide is fed directly to a polymerization process.
    Type: Grant
    Filed: August 7, 1992
    Date of Patent: November 2, 1993
    Assignee: Cargill, Incorporated
    Inventors: Patrick R. Gruber, Eric S. Hall, Jeffrey J. Kolstad, Matthew L. Iwen, Richard D. Benson, Ronald L. Borchardt
  • Patent number: 5247059
    Abstract: A process for the continuous production of substantially purified lactide and lactide polymers from an ester of lactic acid including the steps of forming crude lactide in the presence of a catalyst means to form a condensation reaction by-product and polylactic acid and depolymerizing the polylactic acid molecules followed by subsequent purification of the crude lactide in a distillation system. A purified lactide is then polymerized.
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: September 21, 1993
    Assignee: Cargill, Incorporated
    Inventors: Patrick R. Gruber, Eric S. Hall, Jeffrey J. Kolstad, Matthew L. Iwen, Richard D. Benson, Ronald L. Borchardt
  • Patent number: 5247058
    Abstract: A process for the continuous production of polylactide polymers from lactic acid which incorporates removal of water or a solvent carrier to concentrate the lactic acid feed followed by polymerization to a low-molecular-weight prepolymer. This prepolymer is fed to a reactor in which a catalyst is added to facilitate generation of lactide, the depolymerization product of polylactic acid. The lactide generated is continuously fed to a distillation system as a liquid or vapor wherein water and other impurities are removed. The resultant purified liquid lactide is fed directly to a polymerization process.
    Type: Grant
    Filed: August 7, 1992
    Date of Patent: September 21, 1993
    Assignee: Cargill, Incorporated
    Inventors: Patrick R. Gruber, Eric S. Hall, Jeffrey J. Kolstad, Matthew L. Iwan, Richard D. Benson, Ronald L. Borchardt
  • Patent number: 5142023
    Abstract: A process for the continuous production of polylactide polymers from lactic acid which incorporates removal of water or a solvent carrier to concentrate the lactic acid feed followed by polymerization to a low-molecular-weight prepolymer. This prepolymer is fed to a reactor in which a catalyst is added to facilitate generation of lactide, the depolymerization product of polylactic acid. The lactide generated is continuously fed to a distillation system as a liquid or vapor wherein water and other impurities are removed. The resultant purified liquid lactide is fed directly to a polymerization process.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: August 25, 1992
    Assignee: Cargill, Incorporated
    Inventors: Patrick R. Gruber, Eric S. Hall, Jeffrey J. Kolstad, Matthew L. Iwen, Richard D. Benson, Ronald L. Borchardt