Patents Assigned to PRS, LLC
  • Patent number: 5977294
    Abstract: A process for polymer deformulation by solvent solution filtration begins by including formulated polymers and/or polymer products in a recycle stream. The formulated polymer products include a quantity of soluble polymers and/or insoluble polymers, soluble and/or insoluble colorants, formulations and additives. The recycle stream is placed in a solvent, taking the polymer and formulations into a solvent/polymer solution. Next, the solution is processed through a filtration stage. A quantity of mineral filter aid particles are then added to the solution to adsorb formulations contained in the solution. One of the mineral filter aids must be some form of carbon, preferably activated carbon. Other mineral filter aids may include diatomaceous earth. The solvent/polymer solution is then subjected to an additional polish filtration stage to remove substantially all of the mineral filter agents and associated formulations.
    Type: Grant
    Filed: May 13, 1997
    Date of Patent: November 2, 1999
    Assignee: PRS, LLC
    Inventor: Andrew F. Hoehn