Patents by Inventor Wieland Hovestadt

Wieland Hovestadt 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).

  • Process for recovering binder components from lacquer sludge
    Patent number: 5344851
    Abstract: The present invention relates to a process for recovering and recycling the organic binder components accumulating as overspray during the spraying of a solvent-containing, two-component polyurethane lacquer or a solvent-containing, moisture-curing, one-component polyurethane lacquer byi) washing the overspray out of the exhaust air of a coating plant with the aid of an aqueous medium which a) contains in dissolved or dispersed form compounds that exhibit greater reactivity towards isocyanate groups than either water or the isocyanate-reactive groups present in two-component polyurethane lacquers, and b) may contain emulsifiers,ii) isolating the chemically modified overspray formed in step (i) in the form of lacquer sludge by treatment with coagulating agents, which may be present in the aqueous medium,iii) mixing the lacquer sludge, containing fully reacted lacquer constituents, coagulating agents and water, optionally after a portion of the water is removed, with an organic solvent andiv) separating the org
    Type: Grant
    Filed: April 28, 1993
    Date of Patent: September 6, 1994
    Assignee: Bayer Aktiengesellschaft
    Inventors: Wieland Hovestadt, Jochen Bruck, Volker Schneider
  • Process for recovering and recycling organic binder components from a coatings slurry
    Patent number: 5281629
    Abstract: The present invention relates to a process for recovering and recycling the organic binder components accumulating during the spraying of a solvent-containing, two-component polyurethane coating or a solvent-containing, moisture-curing one-component polyurethane coating byi) forming a coatings slurry containing the organic binder components, water and a coagulating agent,ii) mixing the coatings slurry, optionally after removing a portion of the water, with an organic solvent which is inert towards isocyanate groups,iii) reacting the free isocyanate groups present in the mixture obtained in step (ii) with a compound containing one isocyanate-reactive group which is more reactive with isocyanate groups than both water and the isocyanate-reactive component of the two-component polyurethane coating, if present, andiv) removing any remaining water and insoluble components from the organic phase accumulating in step (iii) and recovering the organic phase containing the organic binder components.
    Type: Grant
    Filed: February 10, 1993
    Date of Patent: January 25, 1994
    Assignee: Bayer Aktiengesellschaft
    Inventors: Wieland Hovestadt, Lothar Kahl, Juergen Meixner, Christian Wamprecht, Volker Schneider, Manfred Schoenfelder