Patents by Inventor Karin U. Thomas

Karin U. Thomas 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).

  • Production of lignosulfonate additives
    Patent number: 4892588
    Abstract: A method of producing a lignin dispersant composition comprising the steps of methylolating a lignin compound by reaction of less than about 2 moles formuladehyde per 1,000 grams of the lignin, and sulfonating the methylolated lignin by reaction from about 2.5 to 3.5 moles of the sulfite or bisulfite compound per 1,000 grams of lignin at an initial reaction pH of below about 6.6 and at a temperature of at least about 170.degree. C., while allowing the pH of the reaction mixture to rise to a final pH of greater than 7.5 to sequentially sulfomethylate the aromatic nucleus and sulfonate the side chain of the lignin.The products of the method find particular use as dispersants in dye compositions and carbon black compositions with lower viscosity and extended shelf-life storage of the composition.
    Type: Grant
    Filed: October 24, 1988
    Date of Patent: January 9, 1990
    Assignee: Westvaco Corporation
    Inventors: Peter Dilling, Vaughn R. Loeffler, Gerald Prazak, Karin U. Thomas