Patents by Inventor Luann R. Marshall

Luann R. 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).

  • Patent number: 4833009
    Abstract: Process for removing color-formers from polymeric sulfonated phenol-formaldehyde condensation products so as provide condensation products having reduced tendencies to turn yellow and which provide stain-resistance to polyamide textile substrates which comprises dissolving a polymeric sulfonated phenolformaldehyde condensation product in a aqueous base, acidifying the resulting aqueous solution so as to form a slurry, heating the slurry so as to form a two-phase system comprising an aqueous solution and a water-soluble taffy-like material, separating the aqueous solution and the water-insoluble material from one another, and dissolving the wate-insoluble material in an aqueous base.
    Type: Grant
    Filed: March 25, 1988
    Date of Patent: May 23, 1989
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Luann R. Marshall