Patents by Inventor Jan van Drongelen

Jan van Drongelen 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 hydrotreating resins to lighten color
    Patent number: 5817900
    Abstract: The color of hydrocarbon resins having carbon-carbon double bonds and containing color bodies is lightened by a hydrotreating process consisting essentially of contacting the resin with hydrogen at a hydrogen pressure of 1 to about 20 bar (14.5 to about 290 psi) in the presence of a catalyst that promotes the hydrogenation of the color bodies without substantially changing the softening point or the content of carbon-carbon double bonds in the resin. The preferred catalyst is nickel/zinc oxide on SiO.sub.2.
    Type: Grant
    Filed: February 1, 1996
    Date of Patent: October 6, 1998
    Assignee: Hercules Incorporated
    Inventors: Erik Berrevoets, Jan van Drongelen