Patents by Inventor Udo Stark

Udo Stark 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).

  • Method for the production of urea fertilizer with elemental sulphur and the product thereof
    Patent number: 7998235
    Abstract: The present invention relates to a method for the production of a urea fertilizer with elemental sulphur from sulphur in liquid stage and a liquid urea melt. The surface tension between the two phases of sulphur and urea are influenced in the liquid stage at temperatures above the melting points, by supply of an additive being temperature stable and amphoteric to the liquid sulphur/urea melt to obtain a homogeneous mixed phase, that subsequently is distributed and solidified. The invention also relates to a urea-sulphur fertilizer where the fertilizer comprises urea and elemental sulphur and an additive being temperature stable and amphoteric.
    Type: Grant
    Filed: June 17, 2002
    Date of Patent: August 16, 2011
    Assignee: Yara International ASA
    Inventors: Sven Kohnke, Uwe Ladwig, Jürgen Maaz, Udo Stark
  • Method for the production of urea fertilizer with elemental sulphur and the product thereof
    Publication number: 20050204792
    Abstract: The present invention relates to a method for the production of a urea fertilizer with elemental sulphur from sulphur in liquid stage and a liquid urea melt. The surface tension between the two phases of sulphur and urea are influenced in the liquid stage at temperatures above the melting points, by supply of an additive being temperature stable and amphoteric to the liquid sulphur/urea melt to obtain a homogeneous mixed phase, that subsequently is distributed and solidified. The invention also relates to a urea-sulphur fertilizer where the fertilizer comprises urea and elemental sulphur and an additive being temperature stable and amphoteric.
    Type: Application
    Filed: June 17, 2002
    Publication date: September 22, 2005
    Inventors: Sven Kohnke, Uwe Ladwig, Jurgen Maaz, Udo Stark