The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 17, 1991
Filed:
Jan. 19, 1989
Peter Dilling, Isle of Palms, SC (US);
Westvaco Corporation, New York, NY (US);
Abstract
A sulfonated lignin composition suitable for use as an additive in other chemical compositions and processes having improved solubility in aqueous medium at varying pH levels, and a method of producing such sulfonated water-soluble lignin products by reaction of an unsulfonated or a sulfonated starting lignin compound with sulfuric acid having a concentration of at least about 95%, while maintaining the temperature of the reaction below 40.degree. C. for a sufficient time to sulfonate the same. Sulfuric acid sulfonation increases the organically bound sulfonic acid content of the starting lignin compound at least about 1.7 moles sulfonic acid per mole of lignin, while providing water-solubility of the product at a wide range of pH levels.