Patents by Inventor Alexander J. Marshall

Alexander J. Marshall 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 removing rhodium-containing catalyst residue from hydrogenated nitrile rubber
    Patent number: 4985540
    Abstract: A process is provided for removing rhodium-containing catalyst residue from a solution of hydrogenated nitrile rubber. The process utilizes an ion exchange resin which must be both macroreticular and modified with a selected amine, thiol, carbodithioate, thiourea and/or dithiocarbamate functional group. The process is capable of removing rhodium from viscous rubber solutions containing less than 10 ppm rhodium. In a preferred embodiment, the process is undertaken in an ion-exchange column.
    Type: Grant
    Filed: November 20, 1989
    Date of Patent: January 15, 1991
    Assignee: Polysar Limited
    Inventors: William G. Bradford, Gilles J. Arsenault, Alexander J. Marshall